Mesh

Distribution by Scientific Domains

Kinds of Mesh

  • adaptive mesh
  • anisotropic mesh
  • cartesian mesh
  • coarse mesh
  • computational mesh
  • element mesh
  • fe mesh
  • fine mesh
  • finite element mesh
  • finite-element mesh
  • fixed mesh
  • graded mesh
  • hexahedral mesh
  • hybrid mesh
  • metal mesh
  • polygonal mesh
  • polypropylene mesh
  • prolene mesh
  • quadrilateral mesh
  • surface mesh
  • tetrahedral mesh
  • triangle mesh
  • triangular mesh
  • uniform mesh
  • unstructured mesh
  • unstructured triangular mesh

  • Terms modified by Mesh

  • mesh adaptation
  • mesh bag
  • mesh cage
  • mesh compression
  • mesh density
  • mesh dependency
  • mesh distortion
  • mesh generation
  • mesh geometry
  • mesh kit
  • mesh model
  • mesh network
  • mesh optimization
  • mesh pattern
  • mesh quality
  • mesh refinement
  • mesh repair
  • mesh resolution
  • mesh size
  • mesh term
  • mesh used

  • Selected Abstracts


    Expanding self-help group participation in culturally diverse urban areas: Media approaches to leveraging referent power

    JOURNAL OF COMMUNITY PSYCHOLOGY, Issue 4 2004
    Keith Humphreys
    Accumulating research attests to the benefits of self-help groups for people who have various chronic health problems. Expansion of self-help group participation may enable a broader portion of society to experience these health benefits. The Media and Education for Self-Help (MESH) Project was an effort to increase interest in health-related self-help groups among middle- and lower-income people in two California urban areas with minority,majority populations. A diverse coalition of self-help group leaders designed English- and Spanish-language radio public service announcements and posters that were disseminated in Oakland and Los Angeles. The outcome measures in each urban area were self-help-group-related telephone inquiries to local information and referral agencies (English and Spanish language) and the number of individuals attending self-help groups at agencies hosting many groups. Telephone caller data were also gathered in a nonintervention control urban area (Sacramento). Los Angeles experienced an overall increase in telephone calls about self-help groups during the MESH intervention, whereas the control urban area had no change in the number of telephone calls over the same period. The initial sharp increase in self-help-group-related telephone calls was not sustained in Oakland, however. The number of Spanish-language calls about self-help groups increased 821% in Los Angeles and 149% in Oakland in the period from the 6 months that preceded the project through the first 6 months of the MESH Project. In the MESH Project urban areas, the number of visits to self-help groups was significantly higher in intervention months than in the same calendar months of the preceding year, particularly in Oakland, where the increase exceeded 300 visits to self-help groups per month. These intriguing findings are discussed in terms of their health policy and program evaluation implications. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 413,424, 2004. [source]


    Efficacy of weight loss drugs on obesity and cardiovascular risk factors in obese adolescents: a meta-analysis of randomized controlled trials

    OBESITY REVIEWS, Issue 2 2010
    S. Czernichow
    Summary Weight loss drugs have been developed to reduce the comorbidities associated with excess weight. We conducted a meta-analysis of the efficacy of orlistat and sibutramine on weight, body mass index, waist circumference and cardiovascular risk factors in overweight adolescents. MEDLINE and the Cochrane Library were searched for relevant articles using MESH terms and keywords. Studies were included if they had reported quantitative estimates and standard deviations of the association between each weight loss drug and weight, with information on at least one cardiovascular risk factor. A total of eight trials (three orlistat and five sibutramine) with information on 1391 individuals was included in the present analysis. The mean decrease in weight between the intervention and control groups was 5.25 kg (95% confidence interval: 3.03,7.48) after a minimum follow-up of 6 months. There was evidence of statistical heterogeneity between the studies (I2 = 76%) that was no longer apparent after exclusion of trials of orlistat (mean weight decrease = 5.32 kg; I2 = 38%). There was little evidence that treatment was associated with adverse effects on cardiovascular risk factors but this requires verification from future large trials with longer study follow-up. [source]


    QUADRAPOD MESH FOR POSTERIOR WALL RECONSTRUCTION IN ADULT INGUINAL HERNIAS

    ANZ JOURNAL OF SURGERY, Issue 3 2008
    Shih-Chung Wu
    Inguinal hernia repairs are the most frequently carried out operations worldwide, and open-mesh herniorrhaphies have gained wide acceptance for advantages of little tension, less pain and lower recurrence rates. Even so, potential drawbacks of original open-mesh repairs exist, and we accordingly make some modifications, suggesting a new ,quadrapod' marlex mesh as an alternative. From July 2002 to March 2004, we carried out 288 consecutive inguinal hernia repairs using quadrapod mesh in 273 patients, all of them were male and aged older than 35 years. Patient demographics, operative parameters, morbidity and outcomes were collected in detail. After surgery, patients were followed up every 6 months at one surgeon's clinic and any major abnormality was recorded. Mean age of the 273 patients was 58.7 years. Twenty-eight patients had recurrent hernias and 15 bilateral hernias. Mean surgical duration was 50.7 min. One patient suffered from major wound infection and needed prolonged hospitalization for parenteral antibiotics. Owing to old age and benign prostatic hyperplasia, 11 patients receiving spinal anaesthesia had temporary postoperative urine retention and needed short-term urinary catheter insertion. Most patients were discharged 1 day following surgery. Acute wound pain generally improved within days, and no patients complained of chronic pain or debility necessitating special interventions. With a mean follow up of 40.7 months, no case of recurrent herniation was detected to date. Open-mesh herniorrhaphy using quadrapod mesh provides a cheap, feasible and effective alternative choice in centres with limited resources. Preliminary results are encouraging, and a formal prospective study may be warranted. [source]


    Incorrect and incomplete coding and classification of diabetes: a systematic review

    DIABETIC MEDICINE, Issue 5 2010
    M. A. Stone
    Diabet. Med. 27, 491,497 (2010) Abstract Aims, To conduct a systematic review to identify types and implications of incorrect or incomplete coding or classification within diabetes or between diabetes and other conditions; also to determine the availability of evidence regarding frequency of occurrence. Methods, Medical Subject Headings (MeSH) and free-text terms were used to search relevant electronic databases for papers published to the end of August 2008. Two researchers independently reviewed titles and abstracts and, subsequently, the full text of potential papers. Reference lists of selected papers were also reviewed and authors consulted. Three reviewers independently extracted data. Results, Seventeen eligible studies were identified, including five concerned with distinguishing between Type 1 and Type 2 diabetes. Evidence was also identified regarding: the distinction between diabetes and no-diabetes, failure to specify type of diabetes, and diagnostic errors or difficulties involving maturity-onset diabetes of the young, latent autoimmune diabetes in adults, pancreatic diabetes, persistence of foetal haemoglobin and acquired immune deficiency syndrome (AIDS). The sample was too heterogeneous to derive accurate information about frequency, but our findings suggested that misclassification occurs most commonly in young people. Implications relating to treatment options and risk management were highlighted, in addition to psychological and financial implications and the potential impact on the validity of quality of care evaluations and research. Conclusions, This review draws attention to the occurrence and implications of incorrect or incomplete coding or classification of diabetes, particularly in young people. A pragmatic and clinically relevant approach to classification is needed to assist those involved in making decisions about types of diabetes. [source]


    Searching PubMed for molecular epidemiology studies: The case of chromosome aberrations

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2006
    Donatella Ugolini
    Abstract The available tools for searching literature in the field of Molecular Epidemiology are largely unsatisfactory. To identify major problems in retrieving information on this discipline, we comment here on the results of a literature search on cytogenetic biomarkers in children exposed to environmental pollutants. The search, done on the PubMed/MedLine database, was based on a strategy combining descriptors listed in the PubMed Medical Subject Headings (MeSH) Thesaurus and other available tools (free text or phrase search tools). 178 articles were retrieved by searching the period from January 1, 1980 to November 30, 2004. Only 2 of the 178 articles were indexed by the MeSH term "Epidemiology, molecular" (introduced in 1994) and 30 of 178 by the MeSH term "Biological markers" (introduced in 1989). The case of chromosome aberration (CA) was emblematic of the problem: 44 of 78 articles (56.4%) were not pertinent to the search. The reasons for this poor performance are reported and discussed. Authors and indexers may be able to improve the efficiency of article retrieval in the field of molecular epidemiology by using relevant terms in the title and abstract. This may suggest appropriate MeSH terms to the indexers for the indexing process. As regards the difficulty in identifiyng population studies using CA, the introduction of a specific MeSH term for chromosome aberrations when used as a biomarker would improve the search process. Environ. Mol. Mutagen., 2006. © 2006 Wiley-Liss, Inc. [source]


    Euroethics,a database network on biomedical ethics

    HEALTH INFORMATION & LIBRARIES JOURNAL, Issue 3 2006
    Ylva Gavel
    Background:,euroethics is a database covering European literature on ethics in medicine. It is produced within Eurethnet, a European information network on ethics in medicine and biotechnology. Objectives:, The aim of Euroethics is to disseminate information on European bioethical literature that may otherwise be difficult to find. Methods:, A collaboration model for pooling data from different centres was developed. The policy was to accomplish data uniformity, while still allowing for local differences in terms of software, indexing practices and resources. Records contributed to the database follow common standards in terms of data fields and indexing terms. The indexing terms derive from two thesauri, Thesaurus Ethics in the Life Sciences (TELS) and Medical Subject Headings (MeSH). Combining elements from search tools developed previously, the developers sought to find a technical solution optimized for this data model. An approach relying on a thesaurus database that is loaded along with the bibliographic database is described. Results and conclusions:, The present case study offers examples of possible approaches to several tasks often encountered in database development, such as: merging data from diverse sources, getting the most out of indexing terms used in a database, and handling more than one thesaurus in the same system. [source]


    Effectiveness of interventions that assist caregivers to support people with dementia living in the community: a systematic review

    INTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 2 2008
    Deborah Parker BA, MSocSci
    Executive summary Objectives, The objective of this review was to assess the effectiveness of interventions that assist caregivers to provide support for people living with dementia in the community. Inclusion criteria, Types of participants, Adult caregivers who provide support for people with dementia living in the community (non-institutional care). Types of interventions, Interventions designed to support caregivers in their role such as skills training, education to assist in caring for a person living with dementia and support groups/programs. Interventions of formal approaches to care designed to support caregivers in their role, care planning, case management and specially designated members of the healthcare team , for example dementia nurse specialist or volunteers trained in caring for someone with dementia. Types of studies, This review considered any meta-analyses, systematic reviews, randomised control trials, quasi-experimental studies, cohort studies, case control studies and observational studies without control groups that addressed the effectiveness of interventions that assist caregivers to provide support for people living with dementia in the community. Search strategy, The search sought to identify published studies from 2000 to 2005 through the use of electronic databases. Only studies in English were considered for inclusion. The initial search was conducted of the databases, CINAHL, MEDLINE and PsychINFO using search strategies adapted from the Cochrane Dementia and Cognitive Improvement Group. A second more extensive search was then conducted using the appropriate Medical Subject Headings (MeSH) and keywords for other available databases. Finally, hand searching of reference lists of articles retrieved and of core dementia, geriatric and psycho geriatric journals was undertaken. Assessment of quality, Methodological quality of each of the articles was assessed by two independent reviewers using appraisal checklist developed by the Joanna Briggs Institute and based on the work of the Cochrane Collaboration and Centre for Reviews and Dissemination. Data collection and analysis, Standardised mean differences or weighted mean differences and their 95% confidence intervals were calculated for each included study reported in the meta-analysis. Results from comparable groups of studies were pooled in statistical meta-analysis using Review Manager Software from the Cochrane Collaboration. Heterogeneity between combined studies was tested using standard chi-square test. Where statistical pooling was not appropriate or possible, the findings are summarised in narrative form. Results, A comprehensive search of relevant databases, hand searching and cross referencing found 685 articles that were assessed for relevance to the review. Eighty-five papers appeared to meet the inclusion criteria based on title and abstract, and the full paper was retrieved. Of the 85 full papers reviewed, 40 were accepted for inclusion, three were systematic reviews, three were meta-analysis, and the remaining 34 were randomised controlled trials. For the randomised controlled trials that were able to be included in a meta-analysis, standardised mean differences or weighted mean differences and their 95% confidence intervals were calculated for each. Results from comparable groups of studies were pooled in statistical meta-analysis using Review Manager Software and heterogeneity between combined studies was assessed by using the chi-square test. Where statistical pooling was not appropriate or possible, the findings are summarised in narrative form. The results are discussed in two main sections. Firstly it was possible to assess the effectiveness of different types of caregiver interventions on the outcome categories of depression, health, subjective well-being, self-efficacy and burden. Secondly, results are reported by main outcome category. For each of these sections, meta-analysis was conducted where it was possible; otherwise, a narrative summary describes the findings. Effectiveness of intervention type, Four categories of intervention were included in the review , psycho-educational, support, multi-component and other. Psycho-educational Thirteen studies used psycho-educational interventions, and all but one showed positive results across a range of outcomes. Eight studies were entered in a meta-analysis. No significant impact of psycho-educational interventions was found for the outcome categories of subjective well-being, self-efficacy or health. However, small but significant results were found for the categories of depression and burden. Support Seven studies discussed support only interventions and two of these showed significant results. These two studies were suitable for meta-analysis and demonstrated a small but significant improvement on caregiver burden. Multi-component Twelve of the studies report multi-component interventions and 10 of these report significant outcomes across a broad range of outcome measures including self-efficacy, depression, subjective well-being and burden. Unfortunately because of the heterogeneity of study designs and outcome measures, no meta-analysis was possible. Other interventions Other interventions included the use of exercise or nutrition which resulted in improvements in psychological distress and health benefits. Case management and a computer aided support intervention provided mixed results. One cognitive behavioural therapy study reported a reduction in anxiety and positive impacts on patient behaviour. Effectiveness of interventions using specific outcome categories, In addition to analysis by type of intervention it was possible to analyse results based on some outcome categories that were used across the studies. In particular the impact of interventions on caregiver depression was available for meta-analysis from eight studies. This indicated that multi-component and psycho-educational interventions showed a small but significant positive effect on caregiver depression. Five studies using the outcome category of caregiver burden were entered into a meta-analysis and findings indicated that there were no significant effects of any of interventions. No meta-analysis was possible for the outcome categories of health, self-efficacy or subjective well-being. Implications for practice, From this review there is evidence to support the use of well-designed psycho-educational or multi-component interventions for caregivers of people with dementia who live in the community. Factors that appear to positively contribute to effective interventions are those which: ,,Provide opportunities within the intervention for the person with dementia as well as the caregiver to be involved ,,Encourage active participation in educational interventions for caregivers ,,Offer individualised programs rather than group sessions ,,Provide information on an ongoing basis, with specific information about services and coaching regarding their new role ,,Target the care recipient particularly by reduction in behaviours Factors which do not appear to have benefit in interventions are those which: ,,Simply refer caregivers to support groups ,,Only provide self help materials ,,Only offer peer support [source]


    The Role of Benzodiazepines in the Treatment of Insomnia

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2001
    Meta-Analysis of Benzodiazepine Use in the Treatment of Insomnia
    PURPOSE: To obtain a precise estimate of the efficacy and common adverse effects of benzodiazepines for the treatment of insomnia compared with those of placebo and other treatments. BACKGROUND: Insomnia, also referred to as disorder of initiating or maintaining sleep, is a common problem and its prevalence among older people is estimated to be 23% to 34%.1 The total direct cost in the United States for insomnia in 1995 was estimated to be $13.9 billion.2 The complaint of insomnia in older people is associated with chronic medical conditions; psychiatric problems, mainly depression, chronic pain, and poor perceived general condition;1,3,4 and use of sleep medications.5 Thus in most cases, insomnia is due to some other underlying problem and is not just a consequence of aging.6 Accordingly, the management of insomnia should focus on addressing the primary problem and not just short-term treatment of the insomnia. Benzodiazepines belong to the drug class of choice for the symptomatic treatment of primary insomnia.7 This abstract will appraise a meta-analysis that compared the effect of benzodiazepines for short-term treatment of primary insomnia with placebo or other treatment. DATA SOURCES: Data sources included articles listed in Medline from 1966 to December 1998 and the Cochrane Controlled Trials Registry. The medical subject heading (MeSH) search terms used were "benzodiazepine" (exploded) or "benzodiazepine tranquillizers" (exploded) or "clonazepam,""drug therapy,""randomized controlled trial" or "random allocation" or "all random,""human," and "English language." In addition, bibliographies of retrieved articles were scanned for additional articles and manufacturers of brand-name benzodiazepines were asked for reports of early trials not published in the literature. STUDY SELECTION CRITERIA: Reports of randomized controlled trials of benzodiazepine therapy for primary insomnia were considered for the meta-analysis if they compared a benzodiazepine with a placebo or an alternative active drug. DATA EXTRACTION: Data were abstracted from 45 randomized controlled trials representing 2,672 patients, 47% of whom were women. Fifteen studies included patients age 65 and older and four studies involved exclusively older patients. Twenty-five studies were based in the community and nine involved inpatients. The duration of the studies ranged from 1 day to 6 weeks, with a mean of 12.2 days and median of 7.5 days. The primary outcome measures analyzed were sleep latency and total sleep duration after a sleep study, subjects' estimates of sleep latency and sleep duration, and subjects' report of adverse effects. Interrater reliability was checked through duplicate, independent abstraction of the first 21 articles. Overall agreement was between 95% and 98% (kappa value of 0.90 and 0.95 accordingly) for classification of the studies and validity of therapy, and 76% (kappa value of 0.51) for study of harmful effects. A scale of 0 to 5 was used to rate the individual reports, taking into account the quality of randomization, blinding, follow-up, and control for baseline differences between groups. Tests for homogeneity were applied across the individual studies and, when studies were found to be heterogeneous, subgroup analysis according to a predefined group was performed. MAIN RESULTS: The drugs used in the meta-analysis included triazolam in 16 studies; flurazepam in 14 studies; temazepam in 13 studies; midazolam in five studies; nitrazepam in four studies; and estazolam, lorazepam, and diazepam in two studies each. Alternative drug therapies included zopiclone in 13 studies and diphenhydramine, glutethimide, and promethazine in one study each. Only one article reported on a nonpharmacological treatment (behavioral therapy). The mean age of patients was reported in 33 of the 45 studies and ranged between 29 and 82. SLEEP LATENCY: In four studies involving 159 subjects, there was sleep-record latency (time to fall asleep) data for analysis. The pooled difference indicated that the latency to sleep for patients receiving a benzodiazepine was 4.2 minutes (95% CI = (,0.7) (,9.2)) shorter than for those receiving placebo. Patient's estimates of sleep latency examined in eight studies showed a difference of 14.3 minutes (95% CI = 10.6,18.0) in favor of benzodiazepines over placebo. TOTAL SLEEP DURATION: Analysis of two studies involving 35 patients in which total sleep duration using sleep-record results was compared indicated that patients in the benzodiazepine groups slept for an average of 61.8 minutes (95% CI = 37.4,86.2) longer than those in the placebo groups. Patient's estimates of sleep duration from eight studies (566 points) showed total sleep duration to be 48.4 minutes (95% CI = 39.6,57.1) longer for patients taking benzodiazepines than for those on placebo. ADVERSE EFFECTS: Analysis of eight studies (889 subjects) showed that those in the benzodiazepine groups were more likely than those in the placebo groups to complain of daytime drowsiness (odds ratio (OR) 2.4, 95% confidence interval (CI) = 1.8,3.4). Analysis of four studies (326 subjects) also showed that subjects in the benzodiazepine groups were more likely to complain of dizziness or lightheadedness than the placebo groups. (OR 2.6, 95% CI = 0.7,10.3). Despite the increased reported side effects in the benzodiazepine groups, drop-out rates were similar in the benzodiazepine and placebo groups. For patient reported outcome, there was no strong correlation found for sleep latency data, (r = 0.4, 95% CI = (,0.3) (,0.9)) or for sleep duration (r = 0.2, 95% CI = ,0.8,0.4) between benzodiazepine dose and outcome. COMPARISON WITH OTHER DRUGS AND TREATMENTS: In three trials with 96 subjects, meta-analysis of the results comparing benzodiazepines with zopiclone, did not show significant difference in sleep latency in the benzodiazepine and placebo groups, but the benzodiazepine groups had increased total sleep duration (23.1 min. 95% CI = 5.6,40.6). In four trials with 252 subjects, the side effect profile did not show a statistically significant difference (OR 1.5, CI 0.8,2.9). There was only one study comparing the effect of behavioral therapy with triazolam. The result showed that triazolam was more effective than behavioral therapy in decreasing sleep latency, but its efficacy declined by the second week of treatment. Behavioral therapy remained effective throughout the 9-week follow-up period. There were four small trials that involved older patients exclusively, with three of the studies having less than 2 weeks of follow-up. The results were mixed regarding benefits and adverse effects were poorly reported. CONCLUSION: The result of the meta-analysis shows that the use of benzodiazepines results in a decrease in sleep latency and a significant increase in total sleep time as compared with placebo. There was also a report of significantly increased side effects, but this did not result in increased discontinuation rate. There was no dose-response relationship for beneficial effect seen with the use of benzodiazepines, although the data are scant. Zopiclone was the only alternative pharmacological therapy that could be studied with any precision. There was no significant difference in the outcome when benzodiazepines were compared with zopiclone. There was only one study that compared the effect of benzodiazepines with nonpharmacological therapy; thus available data are insufficient to comment. [source]


    Antimalarial drug quality in Africa

    JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 5 2007
    A. A. Amin PhD
    Abstract Background and objective: There are several reports of sub-standard and counterfeit antimalarial drugs circulating in the markets of developing countries; we aimed to review the literature for the African continent. Methods: A search was conducted in PubMed in English using the medical subject headings (MeSH) terms: ,Antimalarials/analysis'[MeSH] OR ,Antimalarials/standards'[MeSH] AND ,Africa'[MeSH]' to include articles published up to and including 26 February 2007. Data were augmented with reports on the quality of antimalarial drugs in Africa obtained from colleagues in the World Health Organization. We summarized the data under the following themes: content and dissolution; relative bioavailability of antimalarial products; antimalarial stability and shelf life; general tests on pharmaceutical dosage forms; and the presence of degradation or unidentifiable impurities in formulations. Results and discussion: The search yielded 21 relevant peer-reviewed articles and three reports on the quality of antimalarial drugs in Africa. The literature was varied in the quality and breadth of data presented, with most bioavailability studies poorly designed and executed. The review highlights the common finding in drug quality studies that (i) most antimalarial products pass the basic tests for pharmaceutical dosage forms, such as the uniformity of weight for tablets, (ii) most antimalarial drugs pass the content test and (iii) in vitro product dissolution is the main problem area where most drugs fail to meet required pharmacopoeial specifications, especially with regard to sulfadoxine,pyrimethamine products. In addition, there are worryingly high quality failure rates for artemisinin monotherapies such as dihydroartemisinin (DHA); for instance all five DHA sampled products in one study in Nairobi, Kenya, were reported to have failed the requisite tests. Conclusions: There is an urgent need to strengthen pharmaceutical management systems such as post-marketing surveillance and the broader health systems in Africa to ensure populations in the continent have access to antimalarial drugs that are safe, of the highest quality standards and that retain their integrity throughout the distribution chain through adequate enforcement of existing legislation and enactment of new ones if necessary, and provision of the necessary resources for drug quality assurance. [source]


    Ranking indirect connections in literature-based discovery: The role of medical subject headings

    JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 11 2006
    Don R. Swanson
    Arrowsmith, a computer-assisted process for literature-based discovery, takes as input two disjoint sets of records (A, C) from the Medline database. It produces a list of title words and phrases, B, that are common to A and C, and displays the title context in which each B-term occurs within A and within C. Subject experts then can try to find A,B and B,C title-pairs that together may suggest novel and plausible indirect A,C relationships (via B-terms) that are of particular interest in the absence of any known direct A,C relationship. The list of B-terms typically is so large that it is difficult to find the relatively few that contribute to scientifically interesting connections. The purpose of the present article is to propose and test several techniques for improving the quality of the B-list. These techniques exploit the Medical Subject Headings (MeSH) that are assigned to each input record. A MesH-based concept of literature cohesiveness is defined and plays a key role. The proposed techniques are tested on a published example of indirect connections between migraine and magnesium deficiency. The tests demonstrate how the earlier results can be replicated with a more efficient and more systematic computer-aided process. [source]


    Meta-analysis: nitroglycerin for prevention of post-ERCP pancreatitis

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2009
    U. C. BANG
    Summary Background, Acute pancreatitis after ERCP is a severe side effect. Aim, To evaluate the preventive effect of nitroglycerin on post-ERCP pancreatitis by a meta-analysis of randomized clinical studies. Methods, We searched on Pubmed, Embase, Cochrane Library and all abstracts presented at Digestive Disease Week and United European Gastrointestinal Week from 2004 to 2008. We used the MeSH terms ,pancreatitis' together (AND) with the terms: ,glyceryl trinitrate', ,glyceryl dinitrate', ,isosorbide dinitrate' or ,nitroglycerin'. Results, Five clinical studies evaluating the incidence of post-ERCP pancreatitis after administration of nitroglycerin were identified. Meta-analysis including all five studies showed a relative risk (RR) of 0.61 (95% CI; 0.44, 0.86) with the number needed to treat (NNT) of 26 (95% CI: 16, 82). Three studies evaluated nitroglycerin administered by a dermal patch reaching together an RR of 0.66 (95% CI; 0.43, 1.01). The use of nitroglycerin is associated with a significantly increased risk of hypotension (RR 2.25) and headache (RR 3.64). No difference in mortality was observed. Conclusions, Overall, our meta-analysis supports the use of nitroglycerin in the prevention of post-ERCP pancreatitis, but administration of nitroglycerin by the dermal route, which is the preferred route of administration, did not reach statistical significance. [source]


    Searching the Literature Using Medical Subject Headings versus Text Word with PubMed

    THE LARYNGOSCOPE, Issue 2 2006
    Angela A. Chang MD
    Abstract Objective/Hypothesis: This study was conducted to investigate the performance of two search strategies in the retrieval of information from the National Library of Medicine (NLM) on otolaryngology,head and neck surgery related conditions and diagnoses using PubMed. Methods: Two search strategies,one based on the use of Medical Subject Headings (MeSH) and the second based on text word searching,were compared. Results: The MeSH search provided a more efficient search than the text word search. Conclusions: Head and neck surgeons can most efficiently search the NLM using PubMed as a search engine by initiating the search with MeSH terms. Once a key article is identified, the searcher should use the "Related Articles" feature. [source]


    Analysis of a Microbial Community Oxidizing Inorganic Sulfide and Mercaptans

    BIOTECHNOLOGY PROGRESS, Issue 4 2001
    Kathleen E. Duncan
    Successful treatment of refinery spent-sulfidic caustic (which results from the addition of sodium hydroxide solutions to petroleum refinery waste streams) was achieved in a bioreactor containing an enrichment culture immobilized in organic polymer beads with embedded powdered activated carbon (Bio-Sep). The aerobic enrichment culture had previously been selected using a gas mixture of hydrogen sulfide and methyl mercaptan (MeSH) as the sole carbon and energy sources. The starting cultures for the enrichment consisted of several different Thiobacillispp. (T. thioparus, T. denitrificans, T. thiooxidans, and T.neopolitanus), as well as activated sludge from a refinery aerobic wastewater treatment system and sludge from an industrial anaerobic digester. Microscopic examination (light and SEM) of the beads and of microbial growth on the walls of the bioreactor revealed a great diversity of microorganisms. Further characterization was undertaken starting with culturable aerobic heterotrophic microorganisms (sequencing of PCR-amplified DNA coding for 16S rRNA, Gram staining) and by PCR amplification of DNA coding for 16S rRNA extracted directly from the cell mass, followed by the separation of the PCR products by DGGE (denaturing gradient gel electrophoresis). Eight prominent bands from the DGGE gel were sequenced and found to be closest to sequences of uncultured Cytophagales (3 bands),Gram-positive cocci (Micrococcineae), , proteobacteria (3 bands), and an unidentified , proteobacterium. Culturable microbes included several genera of fungi as well as various Gram-positive and Gram-negative heterotrophic bacteria not seen in techniques using direct DNA extraction. [source]


    Amniotomy for Shortening Spontaneous Labour

    BIRTH, Issue 2 2001
    W.D. Fraser
    A substantive amendment to this systematic review was last made on 25 June 1999. Cochrane reviews are regularly checked and updated if necessary. ABSTRACT Background: Early amniotomy has been advocated as a component of the active management of labour. Several randomised trials comparing routine amniotomy to an attempt to conserve the membranes have been published. Their limited sample sizes limit their ability to address the effects of amniotomy on indicators of maternal and neonatal morbidity. Objectives: To study the effects of amniotomy on the rate of Cesarean delivery and on other indicators of maternal and neonatal morbidity (Apgar less than 7 at 5 minutes, admission to NICU). Search strategy: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. Selection criteria: All acceptably controlled trials of amniotomy during first stage of labour were eligible. Data collection and analysis: Data were extracted by two trained reviewers from published reports. Trials were assigned methodological quality scores based on a standardised rating system. Typical odds ratios (ORs) were calculated using Peto's method. Main results: Amniotomy was associated with a reduction in labour duration of between 60 and 120 minutes. There was a marked trend toward an increase in the risk of Cesarean delivery: OR = 1.26; 95% Confidence Interval (CI) = 0.96,1.66. The likelihood of a 5-minute Apgar score less than 7 was reduced in association with early amniotomy (OR = 0.54; 95% CI = 0.30,0.96). Groups were similar with respect to other indicators of neonatal status (arterial cord pH, NICU admissions). There was a statistically significant association of amniotomy with a decrease in the use of oxytocin: OR = 0.79; 95% CI = 0.67,0.92. Reviewers' conclusions: Routine early amniotomy is associated with both benefits and risks. Benefits include a reduction in labour duration and a possible reduction in abnormal 5-minute Apgar scores. The meta-analysis provides no support for the hypothesis that routine early amniotomy reduces the risk of Cesarean delivery. Indeed there is a trend toward an increase in Cesarean section. An association between early amniotomy and Cesarean delivery for fetal distress is noted in one large trial. This suggests that amniotomy should be reserved for women with abnormal labour progress. Citation: Fraser WD, Turcot L, Krauss I, Brisson-Carrol G. Amniotomy for shortening spontaneous labour (Cochrane Review). In: The Cochrane Library, 1, 2001. Oxford: Update Software. MeSH: Amnion/*surgery; Cesarean Section; Female; Human; *Labor; Labor Complications/*prevention & control; Pregnancy The preceding reports are abstracts of regularly updated, systematic reviews prepared and maintained by the Cochrane Collaboration. The full text of the reviews are available in The Cochrane Library (ISSN 1464-780X). The Cochrane Library is prepared and published by Update Software Ltd. All rights reserved. See www.update-software.com or contact Update Software, info@update.co.uk, for information on subscribing to The Cochrane Library in your area. Update Software Ltd, Summertown Pavilion, Middle Way, Oxford OX2 7LG, United Kingdom. (Tel: +44 1865 513902; Fax: +44 1865 516918). [source]


    Pathways and Substrate Specificity of DMSP Catabolism in Marine Bacteria of the Roseobacter Clade

    CHEMBIOCHEM, Issue 3 2010
    Jeroen S. Dickschat Dr.
    Abstract The volatiles released by Phaeobacter gallaeciensis, Oceanibulbus indolifex and Dinoroseobacter shibae have been investigated by GC-MS, and several MeSH-derived sulfur volatiles have been identified. An important sulfur source in the oceans is the algal metabolite dimethylsulfoniopropionate (DMSP). Labelled [2H6]DMSP was fed to the bacteria to investigate the production of volatiles from this compound through the lysis pathway to [2H6]dimethylsulfide or the demethylation pathway to [2H3]-3-(methylmercapto)propionic acid and lysis to [2H3]MeSH. [2H6]DMSP was efficiently converted to [2H3]MeSH by all three species. Several DMSP derivatives were synthesised and used in feeding experiments. Strong dealkylation activity was observed for the methylated ethyl methyl sulfoniopropionate and dimethylseleniopropionate, as indicated by the formation of EtSH- and MeSeH-derived volatiles, whereas no volatiles were formed from dimethyltelluriopropionate. In contrast, the dealkylation activity for diethylsulfoniopropionate was strongly reduced, resulting in only small amounts of EtSH-derived volatiles accompanied by diethyl sulfide in P. gallaeciensis and O. indolifex, while D. shibae produced the related oxidation product diethyl sulfone. The formation of diethyl sulfide and diethyl sulfone requires the lysis pathway, which is not active for [2H6]DMSP. These observations can be explained by a shifted distribution between the two competing pathways due to a blocked dealkylation of ethylated substrates. [source]


    Interaction of Zinc Oxide Clusters with Molecules Related to the Sulfur Vulcanization of Polyolefins ("Rubber")

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 33 2006
    Ralf Steudel Prof. Dr.
    Abstract The vulcanization of rubber by sulfur is a large-scale industrial process that is only poorly understood, especially the role of zinc oxide, which is added as an activator. We used the highly symmetrical cluster Zn4O4 (Td) as a model species to study the thermodynamics of the initial interaction of various vulcanization-related molecules with ZnO by DFT methods, mostly at the B3LYP/6-31+G* level. The interaction energy of Lewis bases with Zn4O4 increases in the following order: COMeSHMeSH (,230), C3H6 (,121), and CH3COOH (,255)]. The important vulcanization accelerator mercaptobenzothiazole (C7H5NS2, MBT) containing several donor sites reacts with the Zn4O4 cluster with proton transfer from the NH group to one of the oxygen atoms of ZnO, and in addition the exocyclic thiono sulfur atom and the nitrogen atom coordinate to one and the same zinc atom, resulting in a binding energy of ,247 kJ,mol,1. A second isomer of [(MBT)Zn4O4] with a strong OH,,,N hydrogen bond rather than a ZnN bond is only slightly less stable (binding energy ,243 kJ,mol,1). The NH form of free MBT is 36 kJ,mol,1 more stable than the tautomeric SH form, while the sulfurized MBT derivative benzothiazolyl hydrodisulfide C7H5NS3 (BtSSH) is most stable with the connectivity >CSSH. [source]


    Examination of Research Trends on Patient Factors in Patients with Implantable Cardioverter Defibrillators,

    CLINICAL CARDIOLOGY, Issue 2 2007
    Lauren A. Stutts B.S.
    Abstract Background The implantable cardioverter defibrillator (ICD) is the most effective treatment available for terminating potentially life-threatening ventricular tachycardia and ventricular fibrillation and reducing the risk of mortality. Despite its established health benefits, ICD therapy is accompanied by a unique array of patient and psychological factors meriting ample research attention. The purpose of this paper is to examine research trends and results regarding patient factors in cardiac and ICD research and to discuss key areas for future research. Hypothesis: An increase in articles associated with patient factors in cardiac and ICD research will be shown over time. Methods: The Medical Subject Heading (MeSH) system in PubMed was used to index articles under a range of psychosocial headings for both cardiovascular disease and ICDs to quantify the frequency of articles published across time, the journals most frequently utilized, the most productive institutions, and the most common areas of inquiry. Results: A significant positive relationship was revealed between patient factors in cardiac research (r = 0.96, p<0.01) and ICD research (r = 0.88, p<0.01) over time. Research is limited by the small number of investigations and institutions. Of the 178 articles on patient factors in ICD research, the most frequent areas of inquiry were psychosocial treatment (70.79%), anxiety (33.15%), quality of life (32.02%), and depression (29.78%). Conclusion: Future research examining positive adjustment is warranted, especially in light of increased prophylactic ICD implantation and possible decreased treatment burden associated with decreased shocks. [source]


    Ranking indirect connections in literature-based discovery: The role of medical subject headings

    JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 11 2006
    Don R. Swanson
    Arrowsmith, a computer-assisted process for literature-based discovery, takes as input two disjoint sets of records (A, C) from the Medline database. It produces a list of title words and phrases, B, that are common to A and C, and displays the title context in which each B-term occurs within A and within C. Subject experts then can try to find A,B and B,C title-pairs that together may suggest novel and plausible indirect A,C relationships (via B-terms) that are of particular interest in the absence of any known direct A,C relationship. The list of B-terms typically is so large that it is difficult to find the relatively few that contribute to scientifically interesting connections. The purpose of the present article is to propose and test several techniques for improving the quality of the B-list. These techniques exploit the Medical Subject Headings (MeSH) that are assigned to each input record. A MesH-based concept of literature cohesiveness is defined and plays a key role. The proposed techniques are tested on a published example of indirect connections between migraine and magnesium deficiency. The tests demonstrate how the earlier results can be replicated with a more efficient and more systematic computer-aided process. [source]


    Nasal Reconstruction with Titanium Mesh

    DERMATOLOGIC SURGERY, Issue 2 2009
    MANUEL ANGEL RODRIGUEZ-PRIETO MD
    First page of article [source]


    Safety of Trans Vaginal Mesh procedure: Retrospective study of 684 patients

    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2008
    Fréderic Caquant
    Abstract Aim:, To study peri-surgical complications after cure of genital prolapse by vaginal route using interposition of synthetic prostheses Gynemesh Prolene Soft (Gynecare) following the Trans Vaginal Mesh (TVM) technique. Methods:, The present retrospective multicentered study comprised 684 patients who underwent surgery at seven French centers between October 2002 and December 2004. All patients had a genital prolapse ,3 (C3/H3/E3/R3) according to International continence society (ICS) classification. According to each case, prosthetic interposition was total, or anterior only or posterior only. Patients were systematically seen 6 weeks, 3 months and 6 months after surgery. Multivaried statistical analysis followed a model of logistic regression applied to each post-surgical complication. Results:, The mean age of patients was 63.5 years (30,94). The mean follow-up period was 3.6 months. 84.3% of patients were post-menopause, 24.3% had hysterectomy, 16.7% previous cure of prolapse, and 11.1% cure of stress urinary incontinence (SUI). During the procedure, hysterectomy was combined in 50.3% of cases, cervix amputation in 1.5%, and cure of SUI in 40.9%. 15.8% were treated for a cystocele only. 14.8% had only a rectocele +/, elytrocele and 69.4% had a prolapse touching both compartments, anterior and posterior. In peri-surgical complications, (2%) were five bladder wounds (0.7%), one rectal wound (0.15%) and seven hemorrhages greater that 200 mL (1%). Among early post-surgical complications (during the first month after surgery) (2.8%) were two pelvic abscesses (0.29%), 13 pelvic hematomas (1.9%), one pelvic cellulitis (0.15%), two vesicovaginal fistulas and one rectovaginal fistula (0.15%). Among late post-surgical complications (33.6%) there were 77 granulomas or prosthetic expositions (11.3% [6.7% in the vaginal anterior wall, 2.1% in the vaginal posterior wall and 4.8% in the fornix]), 80 prosthetic retractions (11.7%), 36 relapse of prolapse (6.9%) and 37 SUI de novo (5.4%). Multivaried analysis shows that previous history of hysterectomy or placing of an isolated anterior prosthesis increase the risk of peri-surgical complication; preserved uterus and isolated posterior prosthesis lessen the risk of granulomas and prosthetic retractions; and association of a Richter's intervention increases the rate of prosthetic retractions. Conclusion:, Cure of genital prolapse with synthetic prostheses interposed by vaginal route is now reliable and can be reproduced with a low rate of peri- and early post-surgical complications. However, our study shows a certain number of late post-surgical complications after insertion of strengthening synthetic vaginal implants (prosthetic expositions and prosthetic retractions). These retrospective results will soon be compared to a prospective study. [source]


    Systematic review: steroid withdrawal in anti-TNF-treated patients with inflammatory bowel disease

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2010
    E. Bultman
    Aliment Pharmacol Ther 2010; 32: 313,323 Summary Background, The increasing awareness of increased risk for opportunistic infections when combining several immunosuppressant drugs led to new treatment goals for inflammatory bowel disease including limited use of steroids. Aim, To conduct a systematic review to establish figures for steroid withdrawal in anti-TNF treated inflammatory bowel disease-patients. Methods, Medline was searched using the search-terms Ulcerative Colitis (UC) [Mesh], Crohn Disease (CD) [Mesh], IBD [Mesh], crohn, colitis, IBD and steroid sparing, all combined with infliximab and adalimumab. We selected English-language publications that addressed the effect of anti-TNF on steroid withdrawal. Studies had to assess patients with luminal CD or UC. Numbers of patients who were able to withdraw steroids were calculated. Results, Six studies could be included; five reporting on infliximab and one on adalimumab. Studies were heterogeneously designed. Overall, in the adult population, up to 38% of the patients were able to withdraw corticosteroids during infliximab therapy. In the paediatric population, up to 75% of the patients were able to withdraw corticosteroids during infliximab therapy. Conclusions, Although a consensus on the definition of steroid-sparing is lacking, approximately two-thirds of the inflammatory bowel disease-patients are unable to withdraw corticosteroid treatment during anti-TNF therapy. [source]


    Laparoscopic repair of ventral incisional hernia

    ANZ JOURNAL OF SURGERY, Issue 4 2002
    Keith B. Kua
    Background: Laparoscopic repair of ventral incisional hernias was first reported in 1993. Since then, there have been sporadic case reports and small series published about this procedure, but it has not been widely adopted. Newer types of composite prosthetic mesh may reduce the potential problem of bowel adhesion. Methods: Thirty cases of laparoscopic ventral incisional hernia repairs (carried out by two surgeons or their senior registrars) have been retrospectively reviewed and reported in this article. The data were obtained from patient records and subsequent phone surveys. Results: Thirty patients between 29 and 82 years (mean: 58 years) underwent this procedure. There were 14 men and 16 women. The average weight of the patients was 81 kg. The hernias were up to 6 or 7 cm in diameter. Mesh was used in 28 cases (polypropylene in 25 cases, expanded polytetrafluoroethylene in two cases and composite mesh in one case). Most meshes were laid intraperitoneally and fixed into position with laparoscopic spiral tacks. Twenty-nine cases were completed laparoscopically. One operation (3.3%) was converted to an open procedure because of severe bowel adherence to the hernia sac. The mean operating time was 52 min for laparoscopic ventral incisional hernia repairs only. All but two patients tolerated an oral diet within 24 h. The postoperative hospital stay ranged from 0 to 11 days, with 17 patients (57%) staying overnight and eight patients (27%) staying another day. Over 80% of the patients returned to house duties within a week. There was no mortality, and minor complications occurred in four patients (14%). One patient had a small bowel obstruction treated successfully by repeat laparoscopy with division of fibrinous adhesions to polypropylene mesh on day four. Follow up ranged from 1 to 69 months (mean: 12 months). One patient did not attend follow-up appointments. There were three cases of hernia recurrence (10%). Conclusion: The results suggest that laparoscopic repair of ventral incisional hernias is a safe, effective and technically feasible operation for small- to medium-sized hernias allowing shorter hospital stay, early recovery and resumption of normal activities. However, recurrence rates are comparable to open mesh hernioplasty especially for larger hernias. [source]


    Dynamic Light: The Media Facades of realities:united

    ARCHITECTURAL DESIGN, Issue 1 2010
    Valentina Croci
    Abstract Valentina Croci reviews the recent work of realities:united, who first came into the spotlight in 2003 with their media facade for the Kunsthaus Graz. She highlights how recent projects, such as the Crystal Mesh for the Iluma Building in Singapore and the exterior of the C4 in Cordoba, Spain, transcend the notion of the digital facade as billboard. Lighting is dynamically applied, in order to enhance the three-dimensional experience of architecture rather than to flatten it. Copyright © 2010 John Wiley & Sons, Ltd. [source]


    Influence of implantation interval on the long-term biocompatibility of surgical mesh

    BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 8 2002
    Dr B. Klosterhalfen
    Background: The aim was to study the long-term tissue response to polypropylene mesh. Methods: This was a retrieval study that investigated 76 polypropylene meshes with a median implantation interval of 18 (range 2,180) months. Mesh was explanted following hernia recurrence, infection or pain. The median implantation interval was 20 (range 4,180) months in the recurrence group, 30 (range 5,48) months in the pain group and 10 (range 2,56) months in the infection group (P < 0·05, infection versus pain or recurrence). The inflammatory response was determined by immunohistochemistry of macrophages (CD68), polymorphonuclear granulocytes (CD15) and T and B lymphocytes (CD3 and CD20). The cell turnover within the interface mesh fibre,recipient tissue was measured by TUNEL for apoptosis or DNA strand breaks, Ki67 for cell proliferation and heat-shock protein (HSP) 70 for cell stress. Results: With the exception of HSP-70, levels of all variables decreased over time. Sex, age, type of previous operation or location of the mesh did not have a significant influence. Conclusion: Long-term incorporated polypropylene mesh in humans has a more favourable tissue response with increasing implantation interval. © 2002 British Journal of Surgery Society Ltd [source]


    Fast and Efficient Skinning of Animated Meshes

    COMPUTER GRAPHICS FORUM, Issue 2 2010
    L. Kavan
    Abstract Skinning is a simple yet popular deformation technique combining compact storage with efficient hardware accelerated rendering. While skinned meshes (such as virtual characters) are traditionally created by artists, previous work proposes algorithms to construct skinning automatically from a given vertex animation. However, these methods typically perform well only for a certain class of input sequences and often require long pre-processing times. We present an algorithm based on iterative coordinate descent optimization which handles arbitrary animations and produces more accurate approximations than previous techniques, while using only standard linear skinning without any modifications or extensions. To overcome the computational complexity associated with the iterative optimization, we work in a suitable linear subspace (obtained by quick approximate dimensionality reduction) and take advantage of the typically very sparse vertex weights. As a result, our method requires about one or two orders of magnitude less pre-processing time than previous methods. [source]


    Exact and Robust (Self-)Intersections for Polygonal Meshes

    COMPUTER GRAPHICS FORUM, Issue 2 2010
    Marcel Campen
    Abstract We present a new technique to implement operators that modify the topology of polygonal meshes at intersections and self-intersections. Depending on the modification strategy, this effectively results in operators for Boolean combinations or for the construction of outer hulls that are suited for mesh repair tasks and accurate mesh-based front tracking of deformable materials that split and merge. By combining an adaptive octree with nested binary space partitions (BSP), we can guarantee exactness (= correctness) and robustness (= completeness) of the algorithm while still achieving higher performance and less memory consumption than previous approaches. The efficiency and scalability in terms of runtime and memory is obtained by an operation localization scheme. We restrict the essential computations to those cells in the adaptive octree where intersections actually occur. Within those critical cells, we convert the input geometry into a plane-based BSP-representation which allows us to perform all computations exactly even with fixed precision arithmetics. We carefully analyze the precision requirements of the involved geometric data and predicates in order to guarantee correctness and show how minimal input mesh quantization can be used to safely rely on computations with standard floating point numbers. We properly evaluate our method with respect to precision, robustness, and efficiency. [source]


    Adaptive and Feature-Preserving Subdivision for High-Quality Tetrahedral Meshes

    COMPUTER GRAPHICS FORUM, Issue 1 2010
    D. Burkhart
    I.3.5 [Computer Graphics]: Curve, surface, solid, and object representations Abstract We present an adaptive subdivision scheme for unstructured tetrahedral meshes inspired by the, -subdivision scheme for triangular meshes. Existing tetrahedral subdivision schemes do not support adaptive refinement and have traditionally been driven by the need to generate smooth three-dimensional deformations of solids. These schemes use edge bisections to subdivide tetrahedra, which generates octahedra in addition to tetrahedra. To split octahedra into tetrahedra one routinely chooses a direction for the diagonals for the subdivision step. We propose a new topology-based refinement operator that generates only tetrahedra and supports adaptive refinement. Our tetrahedral subdivision algorithm is motivated by the need to have one representation for the modeling, the simulation and the visualization and so to bridge the gap between CAD and CAE. Our subdivision algorithm design emphasizes on geometric quality of the tetrahedral meshes, local and adaptive refinement operations, and preservation of sharp geometric features on the boundary and in the interior of the physical domain. [source]


    Embedded Implicit Stand-Ins for Animated Meshes: A Case of Hybrid Modelling

    COMPUTER GRAPHICS FORUM, Issue 1 2010
    D. Kravtsov
    Abstract In this paper, we address shape modelling problems, encountered in computer animation and computer games development that are difficult to solve just using polygonal meshes. Our approach is based on a hybrid-modelling concept that combines polygonal meshes with implicit surfaces. A hybrid model consists of an animated polygonal mesh and an approximation of this mesh by a convolution surface stand-in that is embedded within it or is attached to it. The motions of both objects are synchronised using a rigging skeleton. We model the interaction between an animated mesh object and a viscoelastic substance, which is normally represented in an implicit form. Our approach is aimed at achieving verisimilitude rather than physically based simulation. The adhesive behaviour of the viscous object is modelled using geometric blending operations on the corresponding implicit surfaces. Another application of this approach is the creation of metamorphosing implicit surface parts that are attached to an animated mesh. A prototype implementation of the proposed approach and several examples of modelling and animation with near real-time preview times are presented. [source]


    Wrinkling Coarse Meshes on the GPU

    COMPUTER GRAPHICS FORUM, Issue 3 2006
    J. Loviscach
    The simulation of complex layers of folds of cloth can be handled through algorithms which take the physical dynamics into account. In many cases, however, it is sufficient to generate wrinkles on a piece of garment which mostly appears spread out. This paper presents a corresponding fully GPU-based, easy-to-control, and robust method to generate and render plausible and detailed folds. This simulation is generated from an animated mesh. A relaxation step ensures that the behavior remains globally consistent. The resulting wrinkle field controls the lighting and distorts the texture in a way which closely simulates an actually deformed surface. No highly tessellated mesh is required to compute the position of the folds or to render them. Furthermore, the solution provides a 3D paint interface through which the user may bias the computation in such a way that folds already appear in the rest pose. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation, I.3.7 [Computer Graphics]: Color, shading, shadowing, and texture [source]


    Resampling Feature and Blend Regions in Polygonal Meshes for Surface Anti-Aliasing

    COMPUTER GRAPHICS FORUM, Issue 3 2001
    Mario Botsch
    Efficient surface reconstruction and reverse engineering techniques are usually based on a polygonal mesh representation of the geometry: the resulting models emerge from piecewise linear interpolation of a set of sample points. The quality of the reconstruction not only depends on the number and density of the sample points but also on their alignment to sharp and rounded features of the original geometry. Bad alignment can lead to severe alias artifacts. In this paper we present a sampling pattern for feature and blend regions which minimizes these alias errors. We show how to improve the quality of a given polygonal mesh model by resampling its feature and blend regions within an interactive framework. We further demonstrate sophisticated modeling operations that can be implemented based on this resampling technique. [source]