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Selected AbstractsTwo new lipoaminoacids with complementary modes of action: new prospects to fight out against skin agingINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2010S. Dumont Synopsis The mode of action of two cosmetic active ingredients (AIs), palmitoyl glycine (PG) and cocoyl alanine (CA) was studied with cDNA array experiments and quantitative PCR confirmations, which were performed on experimentally aged human fibroblasts. These preliminary studies revealed complementary profiles. Thus, specific supplementary investigations were then carried out for each AI. Protocols used were based either on in vitro models: (i) biochemical assays, (ii) monolayer cell culture (primary human fibroblasts and keratinocytes) and (iii) the model of capillary-like tube formation by human endothelial cells or on ex vivo models, i.e. topically treated skin explants and both immunohistochemical and ChromameterTM investigations. New prospects are proposed to fight out against skin aging. Indeed, PG and CA showed complementary properties and thus enabled a regulation or a restoration effect on main aging-associated disorders. Thus, they can not only act on tissue architecture, cell,cell interactions and extracellular matrix protection but also on inflammation, cell longevity, skin immune system protection, skin radiance and stem cell survey. Finally, a clinical trial performed on Caucasian women confirmed AI anti-wrinkle efficacy, which was superior to that of a market reference ingredient. In the future, complementary experiments enabling a better understanding of the aging-induced decline of epidermal stem cells would be of a great interest. Résumé Le mode d'action de deux actifs cosmétiques, Palmitoyl glycine (PG) et Cocoyl Alanine (CA), a été déterminéà l'aide d'expériences de cDNA arrays et de confirmations par qPCR, réalisées sur des fibroblastes humains vieillis expérimentalement. Ces études préliminaires ont révélé des modes d'action complémentaires. Des expériences supplémentaires spécifiques ont donc ensuite été réalisées pour chaque actif. Les protocoles utilisés étaient basés sur des modèles in vitro: i) études biochimiques, ii) cultures cellulaires en monocouches (cultures primaires de fibroblastes et de kératinocytes humains) et iii) modèle de formation de pseudo-tubules par des cellules endothéliales humaines; ou sur des modèles ex-vivo, i.e. des explants de peau traités de manière topique et analysés à l'aide d'études immuno-histochimiques et d'un ChromamètreTM. De nouvelles perspectives s'ouvrent pour combattre le vieillissement cutané. En effet, PG et CA montrent des propriétés complémentaires et permettent ainsi une régulation ou une restauration des principaux dysfonctionnements liés à l'âge. Ainsi, ils peuvent agir non-seulement sur l'architecture des tissus, l'interaction entre les cellules et la protection de la matrice extracellulaire mais aussi sur l'inflammation, la longévité cellulaire, la survie des cellules souches, le système de protection immunitaire et l'éclat de la peau. Finalement, des essais cliniques réalisés sur des femmes de type Caucasien ont confirmé l'efficacité antirides des actifs, laquelle était supérieure à celle d'une référence anti-âge du marché. Dans un futur proche, des tests complémentaires pourraient permettre une meilleure compréhension de la dégradation des cellules souches épidermiques au cours du vieillissement. [source] Communicating process architecture for multicores,CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2010D. May Abstract Communicating process architecture can be used to build efficient multicore chips scaling to hundreds of processors. Concurrent processing, communications and input,output are supported directly by the instruction set of the cores and by the protocol used in the on-chip interconnect. Concurrent programs are compiled directly to the chip exploiting novel compiler optimizations. The architecture supports a variety of programming techniques, ranging from statically configured process networks to dynamic reconfiguration and mobile processes. Copyright © 2007 D. May. [source] A protocol to estimate the release of anthropogenic hydrocarbons from contaminated soilsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2003Raymond C. Loehr Abstract An operational protocol, appropriate for a tier 1 or tier 2 type relative risk evaluation of a site that has polycyclic aromatic hydrocarbon (PAH) or petroleum hydrocarbon impacted soils, was developed to estimate the fraction of anthropogenic hydrophobic hydrocarbons that will be released rapidly from such soils. The development of this protocol used over 400 datasets from 40 different field samples to establish and verify the operational protocol. The datasets resulted from four-month kinetic desorption studies of these field samples. Based on the chemicals evaluated, the protocol has greatest application to two, three, and four ring-PAH and to diesel range aliphatic hydrocarbons. The protocol is a simple batch desorption analysis that uses established methods and is conducted for 7 d. The protocol results were verified with specific correlation relationships (r2 = 0.81 to 0.96) to estimate the rapidly releasing fraction (F value) that is obtained in a full, four-month chemical release evaluation. [source] The generation of rhythmic activity in dissociated cultures of rat spinal cordEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2001Jürg Streit Abstract Locomotion in vertebrates is controlled by central pattern generators in the spinal cord. The roles of specific network architecture and neuronal properties in rhythm generation by such spinal networks are not fully understood. We have used multisite recording from dissociated cultures of embryonic rat spinal cord grown on multielectrode arrays to investigate the patterns of spontaneous activity in randomised spinal networks. We were able to induce similar patterns of rhythmic activity in dissociated cultures as in slice cultures, although not with the same reliability and not always with the same protocols. The most reliable rhythmic activity was induced when a partial disinhibition of the network was combined with an increase in neuronal excitability, suggesting that both recurrent synaptic excitation and neuronal excitability contribute to rhythmogenesis. During rhythmic activity, bursts started at several sites and propagated in variable ways. However, the predominant propagation patterns were independent of the protocol used to induce rhythmic activity. When synaptic transmission was blocked by CNQX, APV, strychnine and bicuculline, asynchronous low-rate activity persisted at ,,50% of the electrodes and ,,70% of the sites of burst initiation. Following the bursts, the activity in the interval was transiently suppressed below the level of intrinsic activity. The degree of suppression was proportional to the amount of activity in the preceding burst. From these findings we conclude that rhythmic activity in spinal cultures is controlled by the interplay of intrinsic neuronal activity and recurrent excitation in neuronal networks without the need for a specific architecture. [source] Meta-analysis of the effects of respiratory rehabilitation programmes on exercise capacity in accordance with programme characteristicsJOURNAL OF CLINICAL NURSING, Issue 1 2007HyunSoo Oh PhD Aims and objectives., This study was performed to investigate the effects of respiratory rehabilitation programmes on exercise capacity in terms of the programme type, the protocol used and other programme characteristics. Background., As the suitable rehabilitation programmes have not been specified, diverse programmes are provided in clinics. Design., Meta-analysis of the primary study results Methods., A computerized search through MEDLINE and CINHAL in addition to tracking down references cited in bibliographies of primarily searched studies were performed to obtain sample studies. Finally 19 research reports were examined. Results., The results of meta-regression showed that the combined effect size of the programmes on exercise capacity was unaffected by forced expiratory volume (in one second), age, the duration and frequency of the programme, or study quality. In addition, the results of meta- anova indicated that the combined effect size was not affected by (i) whether a programme was hospital based or not, (ii) whether a programme was lower-extremity or combined low- and upper-extremity exercise training, (iii) measurement time, and (iv) exercise intensity. Conclusions., The effects of programmes on exercise capacity were not differed in terms of the places where rehabilitation programmes were applied, programme content, measurement time, exercise target sites of body, and the duration and frequency of the programme. Relevance to clinical practice., The results of the present study can provide objective data when constructed or applied on a respiratory rehabilitation programme in clinics. [source] How the choice of a computational model could rule the chemical interpretation: The Ni(II) catalyzed ethylene dimerization as a case studyJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 5 2010Vincent Tognetti Abstract In this article, we present a critical study of the theoretical protocol used for the determination of the nickel(II) catalyzed ethylene dimerization mechanism, considered as a representative example of the various problems related to the modeling a catalytic cycle. The choice of an appropriate computational procedure is indeed crucial for the validity of the conclusions that will be drawn from the computational process. The influence of the exchange-correlation functional on energetic profiles and geometries, the role of the basis set describing the metal atom, as well as the importance of the chosen molecular model, have been thus examined in details. From the obtained results, some general conclusions and guidelines are presented, which could constitute useful warnings in modeling homogenous catalysis. Besides, the database constituted by our high-level calculations can be used within benchmarking procedures to assess the performances of new computational methods based on density functional theory. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010 [source] The Application of Ultraviolet Irradiation to Exogenous Sources of DNA in Plasticware and Water for the Amplification of Low Copy Number DNAJOURNAL OF FORENSIC SCIENCES, Issue 4 2006Jeannie Tamariz B.S. ABSTRACT: Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker® 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU-based real-time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications. [source] Application of pharmacokinetic,pharmacodynamic modeling to predict the kinetic and dynamic effects of anti-methotrexate antibodies in miceJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2003Evelyn D. Lobo Abstract We have shown that intravenous (iv) administration of anti-methotrexate (MTX) antibodies (AMAb) reduces the systemic exposure of intraperitoneal (ip) MTX therapy, and we have proposed that AMAb effects on MTX systemic exposure would allow a reduction in MTX-induced systemic toxicity (i.e., producing a desirable antagonistic effect). However, many literature reports have shown that anti-toxin antibodies occasionally demonstrate unexpected agonist-like activity, increasing the extent of toxicity induced by their ligand. In this report, we have utilized a pharmacokinetic,pharmacodynamic (PKPD) model to predict the potential of AMAb to increase or decrease the magnitude of MTX-induced body weight loss in mice. Simulations predicted that both anti-MTX immunoglobulin G (AMI) and anti-MTX Fab fragments (AMF) would lead to increases or decreases in MTX toxicity, with effects dependent on the dosing protocol used. Based on the computer simulations, two protocols were selected for in vivo evaluation of predicted agonistic or antagonistic effects. Murine monoclonal AMI and AMF were produced, purified, and characterized. Agonistic effects were tested after 24-h infusion of ip MTX (10 mg/kg) and iv administration of an equimolar dose of AMI. Antagonistic effects were tested after 72-h infusion of ip MTX (5 mg/kg) and iv infusion of an equimolar dose of AMF. Consistent with model predictions of agonist-like activity, the 24-h AMI protocol led to significantly increased animal mortality (all animals died, p,<,0.005) and mean nadir weight loss (p,<,0.005). Also consistent with the predictions of the PKPD model, the 72-h AMF protocol significantly decreased animal mortality and mean nadir body weight loss (p,<,0.01). Thus, these studies demonstrate that agonistic and antagonistic effects of anti-toxin antibodies may be predicted through the use of an integrated PKPD model. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:1665,1676, 2003 [source] DECREASE IN DYNAMIC VISCOSITY AND AVERAGE MOLECULAR WEIGHT OF ALGINATE FROM LAMINARIA DIGITATA DURING ALKALINE EXTRACTION,JOURNAL OF PHYCOLOGY, Issue 2 2008Peggy Vauchel Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1,4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted alginates. [source] The EuroPrevall-INCO surveys on the prevalence of food allergies in children from China, India and Russia: the study methodologyALLERGY, Issue 3 2010G. W. K. Wong To cite this article: Wong GWK, Mahesh PA, Ogorodova L, Leung TF, Fedorova O, Holla AD, Fernandez-Rivas M, Clare Mills EN, Kummeling I, van Ree R, Yazdanbakhsh M, Burney P. The EuroPrevall-INCO surveys on the prevalence of food allergies in children from China, India and Russia: the study methodology. Allergy 2010; 65: 385,390. Abstract Background:, Very little is known regarding the global variations in the prevalence of food allergies. The EuroPrevall-INCO project has been developed to evaluate the prevalence of food allergies in China, India and Russia using the standardized methodology of the EuroPrevall protocol used for studies in the European Union. The epidemiological surveys of the project were designed to estimate variations in the prevalence of food allergy and exposure to known or suspected risk factors for food allergy and to compare the data with different European countries. Methods:, Random samples of primary schoolchildren were recruited from urban and rural regions of China, Russia and India for screening to ascertain possible adverse reactions to foods. Cases and controls were then selected to answer a detailed questionnaire designed to evaluate the possible risk factors of food allergies. Objective evidence of sensitisation including skin-prick test and serum specific IgE measurement was also collected. Results:, More than 37 000 children from the three participating countries have been screened. The response rates for the screening phase ranged from 83% to 95%. More than 3000 cases and controls were studied in the second phase of the study. Furthur confirmation of food allergies by double blind food challenge was conducted. Conclusions:, This will be the first comparative study of the epidemiology of food allergies in China, India, and Russia using the same standardized methodology. The findings of these surveys will complement the data obtained from Europe and provide insights into the development of food allergy. [source] Use of an in-house approach to study the three-dimensional structures of various outer membrane proteins: structure of the alcaligin outer membrane transporter FauA from Bordetella pertussisACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2009Karl Brillet Bordetella pertussis is the bacterial agent of whooping cough in humans. Under iron-limiting conditions, it produces the siderophore alcaligin. Released to the extracellular environment, alcaligin chelates iron, which is then taken up as a ferric alcaligin complex via the FauA outer membrane transporter. FauA belongs to a family of TonB-dependent outer membrane transporters that function using energy derived from the proton motive force. Using an in-house protocol for membrane-protein expression, purification and crystallization, FauA was crystallized in its apo form together with three other TonB-dependent transporters from different organisms. Here, the protocol used to study FauA is described and its three-dimensional structure determined at 2.3,Å resolution is discussed. [source] Features and preliminary results of the Dutch centre of the ERSPC (Rotterdam, the Netherlands)BJU INTERNATIONAL, Issue 2003M.J. Roobol OBJECTIVE To describe the preliminary results of the Dutch section of a large multicentre study of screening for prostate cancer, the European Randomized study of Screening for Prostate Cancer (ERSPC), initiated in the Netherlands and Belgium in 1991. MATERIALS AND METHODS After a series of five pilot studies which started in 1991, full-capacity screening started in 1994 with the use of a serum prostate-specific antigen (PSA) determination, a digital rectal examination (DRE) and transrectal ultrasonography (TRUS) as screening tests. Depending on the results and the screening protocol used, men were referred for further examination by sextant biopsies (extended with a seventh biopsy if TRUS showed abnormality). The protocols used, efficiency of the different screening tests, number of cancers detected in the pilot studies, initial screening round and preliminary results of the second screening round are described. RESULTS After the pilot studies it became clear that a study of prostate cancer screening was feasible in the Rotterdam area. The screening protocol was workable and the recruitment rate acceptable (39.5%). An inventory of the population registries of Rotterdam and surrounding municipalities, and the known recruitment rate, made it clear that a contribution of 40 000 men (aged 55,74 years) from the Dutch centre to the ERSPC was feasible. The initial screening round started in December 1993 and lasted until December 1999 (protocol 5,10). In all, 42 376 men were randomized and 1014 cancers detected (5.1%). During this screening the protocol was simplified. After evaluating the different screening tests abnormal results of the DRE and TRUS were omitted as an indication for a sextant biopsy. Only a serum PSA level of , 3.0 ng/mL is now used as the indication. The second screening round started in December 1997 and continues. To December 2002, 9920 men were screened for the second time, 4 years after their initial screening visit. To date 446 cancers have been detected (4.5%); this round will last to December 2003. Further evaluation of the screening regimen and characteristics of the cancers detected are constantly assessed within the Dutch ERSPC. Meanwhile a third screening round has also been initiated, which will last to December 2007. CONCLUSION A prostate cancer screening study of the projected magnitude is feasible in Rotterdam; the recruitment rate is acceptable and the screening tests well tolerated. The study has generated many scientific publications and will be of great value in determining whether prostate cancer screening should be part of general healthcare. [source] Immediate Provisional for Single-Tooth Implant Replacement with Brånemark System: Preliminary ReportCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2001Edward Hui MDS, FDSRCS, FRCDC Abstract: Background: The success of osseointegrated implants ad modum Brånemark for single-tooth restorations is documented. Future developments should aim at improving the benefits to patients by decreasing treatment time, minimizing surgical stages, and maximizing esthetic outcomes. Using knowledge from studies of immediate implant placement, one-stage, immediate loading protocols, the authors developed the immediate provisional. Purpose: The purpose of this study was to develop a protocol to provide an immediate solution for restoring a single missing tooth in the esthetic zone. The protocol should be simple, predictable, cost effective, and allow the use of other techniques to improve esthetic outcome. Materials and Method: This prospective clinical study included 24 patients treated from August 1999 to October 2000. Single-tooth implant replacement was done according to immediate provisional protocol. Thirteen of the 24 patients had immediate implant placement after tooth extraction. All implants were placed in the esthetic zone. During surgery, emphasis was placed on obtaining primary stability by achieving bicortical anchorage and maximum insertion torque of at least 40 Ncm. CeraOne (Nobel Biocare) abutments were used, and provisional crowns were fabricated immediately before wound closure. The occlusion was protected by adjacent teeth. Results: Within the follow-up period of between 1 month and 15 months, all fixtures in the 24 patients were stable. Crestal bone loss greater than one thread-width was not detected. The esthetic result was considered satisfactory by all patients. Conclusions: The implant placement and restoration protocol used in this study showed promising initial results for both the immediate implant and healed extraction site groups. The desirable goals of patient satisfaction, excellent esthetic outcomes, and no increase in treatment cost were achieved in this protocol. Further studies to elucidate the potential of the immediate provisional protocol are justified. [source] Comparison of 1- and 2-day protocols for myocardial SPECT: a Monte Carlo studyCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2005H. H. El-Ali Summary Background:, Myocardial perfusion single-photon emission computed tomography (SPECT) is carried out by combining a rest and a stress study that are performed either on one day or two separate days. A problem when performing the two studies on 1 day is that the residual activity from the first study contributes to the activity measured in the second study. Aim:, Our aim was to identify and evaluate trends in the quantification parameters of myocardial perfusion images as a function of separation time between rest and stress. Methods:, A digital phantom was used for the generation of heart images and a Monte Carlo-based scintillation camera program was used to simulate SPECT projection images. In our simulations, the rest images were normal and the stress images included lesions of different types and localization. Two programs for quantification of myocardial perfusion images were used to assess the different images in an automated and objective way. Results:, The summed difference scores observed with the 2-day protocol were 3 ± 1 (mean ± SD) higher for AutoQUANT and 2 ± 1 higher for 4D-MSPECT compared with those observed with the 1-day protocol. The extent values were 2% points higher for the 2-day protocol compared with the 1-day protocol for both programs. Conclusions:, There are differences in the quantitative assessment of perfusion defects depending on the type of protocol used. The contribution of residual activity is larger when a 1-day protocol is used compared with the 2-day protocol. The differences, although small, are of a magnitude that results in a clear shift in quantification parameters. [source] Methods for detecting and identifying retinoids in tissueDEVELOPMENTAL NEUROBIOLOGY, Issue 7 2006Thomas E. Gundersen Abstract Methods for retinoid analysis in tissue include direct spectrophotometry or fluorometry and retinoid responsive reporter constructs in the form of cell reporter assays or transgenic reporter animals, but chromatographic methods dominate and posses several superior features in quantitative analysis. The multitude of extraction protocols used can coarsely be divided into manual liquid-liquid extraction protocols and semi- or fully automated solid phase extraction-based protocols. Liquid chromatographic separation in reversed phase dominates although normal phase is also used. Detection is mainly performed with UV detectors although electrochemical and fluorescence detection is also used. Mass spectrometry in combination with LC is more often used in retinoid analysis and is likely to dominate in the future. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 631,644, 2006 [source] A pilot study of research utilization practices and critical thinking dispositions of Alberta dental hygienistsINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 3 2008SJ Cobban Abstract:, In order to test interventions for increasing uptake of research findings into dental hygiene practice, we must first identify factors that influence research use. There has been little work on this topic in dental hygiene, but much in other disciplines that can provide exemplars of how others have approached the study of this phenomenon. Objectives:, A pilot study was conducted to determine if protocols used to study research utilization (RU) behaviours and critical thinking dispositions (CTD) in nursing could also be applied to dental hygiene. Methods:, A cross-sectional survey design was used with a random sample of 640 practicing dental hygienists in Alberta, Canada. Three questionnaires were included: one to capture measures of RU including direct, indirect and symbolic RU; the California Critical Thinking Dispositions Inventory (CCTDI) and a demographics questionnaire. Results:, Mean responses for the three types of RU were highest for indirect at 3.52 (SD 0.720), followed by direct at 3.13 (SD 0.903) and symbolic 2.86 (SD 0.959). The majority (74.8%) scored between 280 and 350 on the CCTDI (maximum 420). Cronbach's alpha reliability for the RU measures and four of the seven sub-scales were over .7, indicating internal consistency reliability. Conclusions:, The instruments proved reliable for this population, but other challenges, including a low response rate, were identified during the process of using the RU questionnaire in the context of dental hygiene practice. Pilot testing identified the need for improvements to the presentation of scales to reduce cognitive load and improve the response rate. [source] Urban mesh and ad hoc mesh networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 2 2008Anders Nilsson Plymoth Mesh networking is currently gaining much attention, within both academia and industry. Mesh networking allows cheap and fast deployment of wireless services. It is regarded as a very promising solution for urban deployment scenarios as well as for temporary emergency response situations. Another related promising field is that of ad hoc wireless networking, which consists of mobile nodes that dynamically create and maintain a network without the need for any infrastructure. We propose a solution and architecture for urban mesh ad hoc networks, a network that combines mesh networking with ad hoc networks for urban environments. We present four types of ad hoc mesh and ad hoc mesh networks. The most general one consists of mesh nodes, called mesh points (MP), that act as a type of access point for user nodes (UN). The MPs have at least two interfaces: one which is used to communicate with UNs, and one which is used to maintain the mesh access network and transport data. These two interfaces can basically use any type of technology (IEEE 802.11 a/b/g, WiMax, etc.), and for capacity reasons it is generally regarded that the best solution is to let the mesh interface operate on a separate high-capacity channel or channels. An intricate part of these types of networks are routing and location services. In our solution, UN devices operate in ad hoc mode running an ad hoc routing protocol. This allows UNs that wish to communicate to connect directly in an ad hoc manner, or through an MP. An important question is therefore whether two UNs that wish to communicate should connect through the mesh or connect directly. We show that from a capacity point of view whether a UN should route its packets to the closest available MP, or through a ad hoc network, depends on the environment the network is located, the amount traffic and the type of protocols used. Since MPs need to know where to route packets within the mesh, i.e., locating the MP closest to the destination UN, each UN run a small application that registers the UN to the mesh network. In addition to the above features we have developed a new MAC that quickly queries two candidate nodes, which picks the candidate with the currently best radio conditions. This enable nodes to cope with deep dips in signal strength due to fast fading, a well-known problem in urban environments. We show that this new protocol achieves significantly lower delays. We also show that in dense urban environments performance and battery lifetime can be improved if ad hoc technologies are used. Copyright © 2007 John Wiley & Sons, Ltd. [source] Multicenter quality control of the detection of HIV-1 genome in semen before medically assisted procreationJOURNAL OF MEDICAL VIROLOGY, Issue 7 2006Christophe Pasquier Abstract Couples in whom the man is HIV-1-positive may use medically assisted procreation in order to conceive a child without contaminating the female partner. But, before medically assisted procreation, the semen has to be processed to exclude HIV and tested for HIV nucleic acid before and after processing. The performance was evaluated of the technical protocols used to detect and quantify HIV-1 in 11 centers providing medically assisted procreation for couples with HIV-1 infected men by testing panels of seminal plasma and cells containing HIV-1 RNA and/or DNA. The performance of these tests varied due to the different assays used. False positive results were obtained in 14,19% of cases. The sensitivity for RNA detection in seminal plasma was 500,1,000 RNA copies/ml, over 500 RNA copies/106 cells in semen cells, and for DNA detection in semen cells 50,500 DNA copies/106 cells. The use of silica-based extraction seemed to increase the assay performance, whereas the use of internal controls to detect PCR inhibitor did not. This first quality control highlights the need for technical improvements of the assays to detect and quantify HIV in semen fractions and for regular evaluation of their performance. J. Med. Virol. 78:877,882, 2006. © 2006 Wiley-Liss, Inc. [source] Quantitative analysis of the major constituents of St John's wort with HPLC-ESI-MSJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2005Dhammitha H. Chandrasekera A method was developed to profile the major constituents of St John's wort extracts using highperformance liquid chromatography-electrospray mass spectrometry (HPLC-ESI-MS). The objective was to simultaneously separate, identify and quantify hyperforin, hypericin, pseudohypericin, rutin, hyperoside, isoquercetrin, quercitrin and chlorogenic acid using HPLC-MS. Quantification was performed using an external standardisation method with reference standards. The method consisted of two protocols: one for the analysis of flavonoids and glycosides and the other for the analysis of the more lipophilic hypericins and hyperforin. Both protocols used a reverse phase Luna phenyl hexyl column. The separation of the flavonoids and glycosides was achieved within 35 min and that of the hypericins and hyperforin within 9 min. The linear response range in ESI-MS was established for each compound and all had linear regression coefficient values greater than 0.97. Both protocols proved to be very specific for the constituents analysed. MS analysis showed no other signals within the analyte peaks. The method was robust and applicable to alcoholic tinctures, tablet/capsule extracts in various solvents and herb extracts. The method was applied to evaluate the phytopharmaceutical quality of St John's wort preparations available in the UK in order to test the method and investigate if they contain at least the main constituents and at what concentrations. [source] Review article: Managing bone complications after kidney transplantationNEPHROLOGY, Issue 4 2009RAHUL MAINRA SUMMARY Chronic kidney disease mineral and bone disorder (CKD-MBD) describes the laboratory, bone and vascular abnormalities that exist in patients with CKD stages 3,5D and that may persist after transplantation. Persisting abnormalities of bone turnover and abnormal mineralization, together with bone mineral density (BMD) loss from glucocorticoids, may all predispose to a loss of structural integrity and increased fracture risk in kidney and kidney pancreas recipients. Vitamin D, calcitriol, calcitonin and bisphosphonates have all been used to preserve BMD following transplantation, despite a lack of safety data and the potential for some of these drugs to cause harm. A limited number of post-transplant studies utilizing these drugs have not yet documented improved fracture prevention or fracture-related mortality and have not considered allocation based on risk factors for fracture or markers of bone turnover. Targeted allocation of the available therapies based on a stratification of risk appears warranted. This might be achieved using an algorithm incorporating BMD, X-ray evaluation, laboratory investigations including bone turnover markers and the assessment of standard fracture risk factors at the time of and soon after transplantation. This approach, which is similar to protocols used in the general population, may result in more effective management of patients and fewer adverse effects such as adynamic bone disease. Although BMD is a surrogate for fracture risk in the general population it is not validated in this transplant population. Consequently, such an approach should be confirmed by studies that include bone biopsy data and an evaluation of patient level outcomes. [source] Role of photodynamic therapy in psoriasis: a brief reviewPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 5 2008Yasmeen K. Tandon Background and purpose: Photodynamic therapy (PDT) is a light treatment modality which involves either systemic or local application of a photosensitizing compound, which preferentially deposits in the target cells, and is then followed by selective illumination of the lesion with visible light. The purpose of this study was to review the literature to examine the success, side effects, and different protocols used thus far to treat psoriasis using PDT. Methods: A thorough review of the literature was performed and analyzed. Results and conclusions: After a thorough review of the literature, PDT remains a potential treatment for psoriasis. Clinical improvement has been observed in most studies. The major limiting factor seen in many of the studies was the side effect of pain and burning sensations associated with PDT. This highlights the need for other photosensitizers with better tolerability profiles. [source] Determination of nitrogen-15 isotope fractionation in tropine: evaluation of extraction protocols for isotope ratio measurement by isotope ratio mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 24 2009Roland Molinié N -Demethylation of tropine is an important step in the degradation of this compound and related metabolites. With the purpose of understanding the reaction mechanism(s) involved, it is desirable to measure the 15N kinetic isotope effects (KIEs), which can be accessed through the 15N isotope shift (,,15N) during the reaction. To measure the isotope fractionation in 15N during tropine degradation necessitates the extraction of the residual substrate from dilute aqueous solution without introducing artefactual isotope fractionation. Three protocols have been compared for the extraction and measurement of the 15N/14N ratio of tropine from aqueous medium, involving liquid-liquid phase partitioning or silica-C18 solid-phase extraction. Quantification was by gas chromatography (GC) on the recovered organic phase and ,15N values were obtained by isotope ratio measurement mass spectrometry (irm-MS). Although all the protocols used can provide satisfactory data and both irm-EA-MS and irm-GC-MS can be used to obtain the ,15N values, the most convenient method is liquid-liquid extraction from a reduced aqueous volume combined with irm-GC-MS. The protocols are applied to the measurement of 15N isotope shifts during growth of a Pseudomonas strain that uses tropane alkaloids as sole source of carbon and nitrogen. The accuracy of the determination of the 15N/14N ratio is sufficient to be used for the determination of 15N-KIEs. Copyright © 2009 John Wiley & Sons, Ltd. [source] Mechanical Dissociation of Swine Liver to Produce Organoid Units for Tissue Engineering and In Vitro Disease ModelingARTIFICIAL ORGANS, Issue 1 2010Katayun Irani Abstract The complex intricate architecture of the liver is crucial to hepatic function. Standard protocols used for enzymatic digestion to isolate hepatocytes destroy tissue structure and result in significant loss of synthetic, metabolic, and detoxification processes. We describe a process using mechanical dissociation to generate hepatic organoids with preserved intrinsic tissue architecture from swine liver. Oxygen-supplemented perfusion culture better preserved organoid viability, morphology, serum protein synthesis, and urea production, compared with standard and oxygen-supplemented static culture. Hepatic organoids offer an alternative source for hepatic assist devices, engineered liver, disease modeling, and xenobiotic testing. [source] In Vivo Preclinical Anticoagulation Regimens After Implantation of Ventricular Assist DevicesARTIFICIAL ORGANS, Issue 7 2009Diyar Saeed Abstract Ventricular assist devices (VADs) have demonstrated successfully their ability to treat failing circulation of patients with end-stage heart failure. Among the main obstacles with these VADs is thromboembolic events that increase device-related morbidity and mortality. Prior to the clinical application of any newly developed VAD, the feasibility of the device is tested on animal models. Animal species have different hemostatic properties than human patients, and this factor creates a margin of error when comparing the occurrence of VAD-induced thrombosis in an animal versus a human. This detailed literature review provides a thorough documentation of various preclinical anticoagulation protocols used to date, including their outcomes and recommendations for future anticoagulation management strategies. In summary, the outcomes favor a sheep or pig model over other animal models, and discourage the application of a single anticoagulative agent to improve outcomes with any of the currently available devices. [source] [Ru(bpy)2(dcbpy)NHS] Labeling/Aptamer-Based Biosensor for the Detection of Lysozyme by Increasing Sensitivity with Gold Nanoparticle AmplificationCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2008Jianguo Bai Abstract A novel [Ru(bpy)2(dcbpy)NHS] labeling/aptamer-based biosensor combined with gold nanoparticle amplification for the determination of lysozyme with an electrochemiluminescence (ECL) method is presented. In this work, an aptamer, an ECL probe, gold nanoparticle amplification, and competition assay are the main protocols employed in ECL detection. With all the protocols used, an original biosensor coupled with an aptamer and [Ru(bpy)2(dcbpy)NHS] has been prepared. Its high selectivity and sensitivity are the main advantages over other traditional [Ru(bpy)3]2+ biosensors. The electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) characterization illustrate that this biosensor is fabricated successfully. Finally, the biosensor was applied to a displacement assay in different concentrations of lysozyme solution, and an ultrasensitive ECL signal was obtained. The ECL intensity decreased proportionally to the lysozyme concentration over the range 1.0×10,13,1.0×10,8,mol,L,1 with a detection limit of 1.0×10,13,mol,L,1. This strategy for the aptasensor opens a rapid, selective, and sensitive route for the detection of lysozyme and potentially other proteins. [source] | |||||||||||||||||||