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Mean Loss (mean + loss)
Selected AbstractsSolubility of root-canal sealers in water and artificial salivaINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2003E. Schäfer Abstract Aim, To compare the weight loss of eight different root-canal sealers in water and in artificial saliva with different pH values. Methodology, For standardized samples (n = 12 per group), ring moulds were filled with epoxy resin (AH 26, AH Plus)-, silicone (RSA RoekoSeal)-, calcium hydroxide (Apexit, Sealapex)-, zinc oxide,eugenol (Aptal-Harz)-, glass-ionomer (Ketac Endo)- and polyketone (Diaket)-based sealers. These samples were immersed in double-distilled water or artificial saliva with different pH values (7.0, 5.7 and 4.5) for 30 s, 1 min, 2 min, 5 min, 10 min, 20 min, 1 h, 2 h, 10 h, 24 h, 48 h, 72 h, 14 days and 28 days. Mean loss of weight was determined and analysed statistically using a one-way anova and Student,Newman,Keuls test for all pairwise comparisons. Results, Most sealers were of low solubility, although Sealapex, Aptal-Harz and Ketac Endo showed a marked weight loss in all liquids. Even after 28 days of storage in water, AH 26, AH Plus, RSA RoekoSeal, and Diaket showed less than 3% weight loss. At exposure times greater than 14 days, Sealapex showed the significantly greatest weight loss of all sealers tested (P < 0.05). Aptal-Harz and Ketac Endo were significantly more soluble in saliva (pH 4.5) than in water (P < 0.05). Conclusions, Under the conditions of the present study, AH Plus showed the least weight loss of all sealers tested, independent of the solubility medium used. Sealapex, Aptal-Harz and Ketac Endo had a marked weight loss in all liquids. [source] Dissolution of root canal sealer cements in volatile solventsINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2000J. M. Whitworth Whitworth JM, Boursin EM. Dissolution of root canal sealer cements in volatile solvents. International Endodontic Journal, 33, 19,24, 2000. Aim There are few published data on the solubility profiles of endodontic sealers in solvents commonly employed in root canal retreatment. This study tested the hypothesis that root canal sealer cements are insoluble in the volatile solvents chloroform and halothane. Methodology Standardized samples (n=5) of glass ionomer (Ketac Endo), zinc oxide-eugenol (Tubli-Seal EWT), calcium hydroxide (Apexit) and epoxy resin (AH Plus) based sealers were immersed in chloroform or halothane for 30 s, 1 min, 5 min and 10 min. Mean loss of weight was plotted against time of exposure, and differences in behaviour assessed by multiple paired t-tests (P <0.01). Results Clear differences were shown in the solubility profiles of major classes of root canal sealer cements in two common volatile solvents. In comparison with other classes of material, Ketac Endo was the least soluble in chloroform and halothane (P <0.01), with less than 1% weight loss after 10 min exposure to either solvent. Apexit had low solubility with 11.6% and 14.19% weight loss after 10 min exposure to chloroform and halothane, respectively. The difference between solvents was not significant (P >0.01). Tubli-Seal EWT was significantly less soluble in halothane than chloroform (5.19% and 62.5% weight loss after 10 min exposure, respectively (P <0.01)). Its solubility in halothane was not significantly different from that of Apexit. AH Plus was significantly more soluble than all other materials in both chloroform and halothane (96% and 68% weight loss after 10 min exposure, respectively (P <0.01)). Conclusions There are significant differences in the solubility profiles of major classes of root canal sealer in common organic solvents. Efforts should continue to find a more universally effective solvent for use in root canal retreatment. [source] Surface Action Potential and Contractile Properties of the Human Triceps Surae Muscle: Effect of ,Dry' Water ImmersionEXPERIMENTAL PHYSIOLOGY, Issue 1 2002Yuri A. Koryak The effects of 7 days of ,dry' water immersion were investigated in six subjects. Changes in the contraction properties were studied in the triceps surae muscle. After immersion, the maximal voluntary contraction (MVC) was reduced by 18.9% (P < 0.01), and the electrically evoked (150 impulses s,1) maximal tension during tetanic contraction (Po) was reduced by 8.2% (P > 0.05). The difference between Po and MVC expressed as a percentage of Po and referred to as force deficiency was also calculated. The force deficiency increased by 44.1% (P < 0.001) after immersion. The decrease in Po was associated with increased maximal rates of tension development (7.2%) and relaxation. The twitch time-to-peak was not significantly changed, and half-relaxation and total contraction time were decreased by 5.3% and 2.8%, respectively, but the twitch tension (Pt) was not significantly changed and the Pt/Po ratio was decreased by 8.7%. The 60 s intermittent contractions (50 impulses s,1) decreased tetanic force to 57% (P < 0.05) of initial values, but force reduction was not significantly different in the two fatigue-inducing tests: fatigue index (the mean loss of force of the last five contractions, expressed as a percentage of the mean value of the first five contractions) was 36.2 ± 5.4% vs. 38.6 ± 2.8%, respectively (P > 0.05). While identical force reduction was present in the two fatigue-inducing tests, it would appear that concomitant electrical failure was considerably different. Comparison of the electrical and mechanical alterations recorded during voluntary contractions, and in contractions evoked by electrical stimulation of the motor nerve, suggests that immersion not only modifies the peripheral processes associated with contraction, but also changes central and/or neural command of the contraction. At peripheral sites, it is proposed that the intracellular processes of contraction play a role in the contractile impairment recorded during immersion. [source] Erosion and Nutrient Loss on Sloping Land under Intense Cultivation in Southern VietnamGEOGRAPHICAL RESEARCH, Issue 1 2008NGUYEN VAN DE Abstract To help improve the well-being of the local people, a joint Vietnamese-UK team set out to establish a way of estimating soil and nutrient losses under different land management scenarios, using field data extrapolated through remote sensing and GIS, to obtain catchment-wide estimates of the impact of land cover change. Immigration from remote provinces to the Dong Phu District of Binh Phuóc Province, about 120 km north of Ho Chi Minh City, has led to disruption of soil surface stability on easily eroded clayey sandstones, creating rapid nutrient depletion that affects crop yields and siltation in the channel of the Rach Rat river downstream. The poor farmers of the areas see crop yields drop dramatically after two or three years of cultivation due to the fertility decline. Soil loss varies dramatically between wet season and dry season and with ground cover. Erosion bridge measurements showed a mean loss of 85.2 t ha,1 y,1 under cassava saplings with cashew nuts, 43.3 t ha,1 y,1 on uncultivated land and 41.7 t ha,1 y,1 under mature cassava. The rates of erosion were higher than those reported in many other parts of Vietnam, reflecting the high erodibility of the friable sandy soils on the steep side-slopes of the Rach Rat catchment. However, although the actual measurements provide better soil loss data than estimates based on the parameters of soil loss equations, a large number of measurement sites is needed to provide adequate coverage of the crop and slope combinations in this dissected terrain for good prediction using GIS and remote sensing. [source] The European carbon balance.GLOBAL CHANGE BIOLOGY, Issue 5 2010Part 2: croplands Abstract We estimated the long-term carbon balance [net biome production (NBP)] of European (EU-25) croplands and its component fluxes, over the last two decades. Net primary production (NPP) estimates, from different data sources ranged between 490 and 846 gC m,2 yr,1, and mostly reflect uncertainties in allocation, and in cropland area when using yield statistics. Inventories of soil C change over arable lands may be the most reliable source of information on NBP, but inventories lack full and harmonized coverage of EU-25. From a compilation of inventories we infer a mean loss of soil C amounting to 17 g m,2 yr,1. In addition, three process-based models, driven by historical climate and evolving agricultural technology, estimate a small sink of 15 g C m,2 yr,1 or a small source of 7.6 g C m,2 yr,1. Neither the soil C inventory data, nor the process model results support the previous European-scale NBP estimate by Janssens and colleagues of a large soil C loss of 90 ± 50 gC m,2 yr,1. Discrepancy between measured and modeled NBP is caused by erosion which is not inventoried, and the burning of harvest residues which is not modeled. When correcting the inventory NBP for the erosion flux, and the modeled NBP for agricultural fire losses, the discrepancy is reduced, and cropland NBP ranges between ,8.3 ± 13 and ,13 ± 33 g C m,2 yr,1 from the mean of the models and inventories, respectively. The mean nitrous oxide (N2O) flux estimates ranges between 32 and 37 g C Eq m,2 yr,1, which nearly doubles the CO2 losses. European croplands act as small CH4 sink of 3.3 g C Eq m,2 yr,1. Considering ecosystem CO2, N2O and CH4 fluxes provides for the net greenhouse gas balance a net source of 42,47 g C Eq m,2 yr,1. Intensifying agriculture in Eastern Europe to the same level Western Europe amounts is expected to result in a near doubling of the N2O emissions in Eastern Europe. N2O emissions will then become the main source of concern for the impact of European agriculture on climate. [source] Chromogenic in situ hybridization analysis of melastatin mRNA expression in melanomas from American Joint Committee on Cancer stage I and II patients with recurrent melanomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 9 2006L. Hammock Objective:, To determine whether loss of melastatin (MLSN) is a universal phenomenon in American Joint Committee on Cancer (AJCC) stage I and II melanoma patients who experienced recurrence. Material and methods:, Paraffin blocks of primary melanomas (PMs) were retrieved from 30 patients who had a negative sentinel lymph node biopsy and developed recurrent melanoma (AJCC stage I and II). Chromogenic in situ hybridization (CISH) methods were utilized to evaluate the expression of MLSN mRNA. These results were correlated with clinicopathologic data. Results:, Variable, heterogeneous expression of MLSN mRNA was identified in normal, in situ and invasive melanocytes within and between cases. For the invasive PM component, 24 (80%) had focal, regional or complete loss of MLSN mRNA. The remaining 20% had either regional or total partial downregulation of MLSN mRNA. Intact MLSN mRNA expression was present regionally in 14/30 (47%), with mean relative tumor area of 38%, range 5,85%. Increasing loss of MLSN mRNA significantly correlated with increasing tumor depth and microsatellites (r = 0.1/0.4, p = 0.04). However, thin, AJCC T stage 1a PM had higher relative mean loss than intermediate AJCC T stage 2a/2b/3a thickness PM (65% vs. 34%/48%/25%). Increasing loss of MLSN mRNA significantly impacted on disease free survival (DFS) by multivariate analysis (58 vs. 0% 2 years DFS, , 75 vs. >75% mRNA loss, p = 0.02). Decreased overall survival significantly correlated with increasing age and vascular invasion on multivariate analysis. Conclusion:, Extensive loss of MLSN in PM correlated with aggressive metastatic melanoma. Ancillary testing for MLSN mRNA expression by CISH could offer a means to more accurately identify AJCC stage I and II patients at risk for metastatic disease, who could benefit from adjuvant therapy. [source] Improvement in arm and post-partum abdominal and flank subcutaneous fat deposits and skin laxity using a bipolar radiofrequency, infrared, vacuum and mechanical massage deviceLASERS IN SURGERY AND MEDICINE, Issue 10 2009Lori Brightman MD Abstract Background and Objectives Skin laxity of the body is a growing cosmetic concern. Laxity can result from chronological or photoaging and changes in body dimensions during pregnancy or weight loss. The end result is loose, sagging skin, and localized fat deposits. Liposuction and abdominoplasty or brachioplasty are established approaches to these issues. Patient desire for alternatives to surgical correction has spawned the development of non-invasive body contouring devices. The combination of infrared light (IR), bipolar radiofrequency (RF), vacuum and mechanical massage (Velashape, Syneron Medical Ltd, Israel) has demonstrated efficacy in improving skin appearance and circumference of the thighs [Goldberg et al., Derm Surg 2008; 34:204,209; Fisher et al., Derm Surg 2005; 31:1237,1241; Arnoczky and Aksan, J Am Acad Orthop Surg 2000; 8:305,313; Alster and Tanzi, J Cosmetic Laser Therapy 2005; 7:81,85; Wanitphakdeedecha and Manuskiatti, J Cosmet Dermatol 2006; 5:284,288; Nootheti et al., Lasers Surg Med 2006; 38: 908,912], but only anecdotal evidence has supported its use on other anatomic locations. This study was designed to evaluate the efficacy and safety of Velashape on additional body sites and more rigorously examine the technology's impact on upper arm as well as abdominal and flank circumference. Study Design and Methods Subjects were 28,70 years old, skin types I,V. Nineteen subjects underwent 5 weekly treatments of the upper arms, and 10 subjects underwent 4 weekly treatments of the abdomen and flanks. Treatments were performed using Velashape. Circumference measurements, photographs, and subject weights were performed prior to treatment and at 1- and 3-month follow-ups. Subjects were asked to record their treatment satisfaction level. Results Change in arm circumference, at the 5th treatment was statistically significant with a mean loss of 0.625,cm. At 1- and 3-month follow-ups, mean loss was 0.71 and 0.597,cm respectively. Reduction of abdominal circumference at 3rd treatment was statistically significant with a 1.25,cm mean loss. At 1- and 3-month follow-ups, average loss was 1.43 and 1.82,cm respectively. Conclusions This study demonstrates with statistical significance, sustainable reduction in circumference and improvement in appearance of arms and abdomen following treatment with Velashape. Lasers Surg. Med. 41:791,798, 2009. © 2009 Wiley-Liss, Inc. [source] Quantitation of Mandibular Symphysis Volume as a Source of Bone GraftingCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2010Fernando Verdugo DDS ABSTRACT Background: Autogenous intramembranous bone graft present several advantages such as minimal resorption and high concentration of bone morphogenetic proteins. A method for measuring the amount of bone that can be harvested from the symphysis area has not been reported in real patients. Purpose: The aim of the present study was to intrasurgically quantitate the volume of the symphysis bone graft that can be safely harvested in live patients and compare it with AutoCAD® (version 16.0, Autodesk, Inc., San Rafael, CA, USA) tomographic calculations. Materials and Methods: AutoCAD software program quantitated symphysis bone graft in 40 patients using computerized tomographies. Direct intrasurgical measurements were recorded thereafter and compared with AutoCAD data. The bone volume was measured at the recipient sites of a subgroup of 10 patients, 6 months post sinus augmentation. Results: The volume of bone graft measured by AutoCAD averaged 1.4 mL (SD 0.6 mL, range: 0.5,2.7 mL). The volume of bone graft measured intrasurgically averaged 2.3 mL (SD 0.4 mL, range 1.7,2.8 mL). The statistical difference between the two measurement methods was significant. The bone volume measured at the recipient sites 6 months post sinus augmentation averaged 1.9 mL (SD 0.3 mL, range 1.3,2.6 mL) with a mean loss of 0.4 mL. Conclusion: AutoCAD did not overestimate the volume of bone that can be safely harvested from the mandibular symphysis. The use of the design software program may improve surgical treatment planning prior to sinus augmentation. [source] Early Functional Loading of Brånemark Dental Implants: 5-Year Clinical Follow-up StudyCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2000Ingvar Ericsson DDS ABSTRACT Background: Short-term clinical studies have indicated the possibility of one-stage surgery and early loading of machined titanium implants. However, long-term data comparing the outcome to the conventional two-stage technique are missing. Purpose: A clinical and radiographic study was performed to compare the outcome of oral rehabilitation of the endentulous mandible by fixed suprastructures connected to implants installed according to either (1) a one-stage surgical procedure and early loading (experimental group - EG) or (2) the original two-stage concept (reference group - RG). The EG and RG comprised 16 and 11 subjects, respectively. Materials and Methods: The following specific inclusion criterion were adopted: (1) all patients had to consider themselves to be in good general health, (2) the amount of bone had to enable the installation of five to six, at least 10-mm long fixtures (Mk II fixtures; Nobel Biocare AB, Göteborg, Sweden) between the mental foramina, and (3) the patients had to be available for the follow-up and maintenance program. A total of 88 implants were placed in the EG compared to 30 in the RG. In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At delivery of the suprastructures, all patients were radiographically examined, an examination that was repeated at the 18- and 60-month follow-ups. Results: The analysis of the radiographs from the EG disclosed that during the observation period, between 18 and 60 months, the mean loss of bone support amounted to 0.2 mm (SD = 0.4). The corresponding value observed in the RG was 0.0 mm (SD = 0.5). During the 60-month observation period, no fixture was lost in any of the two groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. Conclusions: This clinical study demonstrated that it is, at least based on a 5-year observation period, possible to successfully load via a permanent fixed rigid cross-arch suprastructure titanium dental implants soon after installation. However, such a treatment approach has to be strictly limited to the interforamina area of the endentulous mandible. Furthermore, the bone resorption was found to be within the same range around such implants as around implants installed and loaded according to the original two-stage protocal. [source] | |||||||||||||