834 resultados para Automotive supplies - Design - Simulation methods


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Collective dynamic properties in Lennard-Jones crystals are investigated by molecular dynamics simulation. The study is focused on properties such as the dynamic structure factors, the longitudinal and transverse currents and the density of states. The influence on these properties of the structural disorder is analyzed by comparing the results for one-component crystals with those for liquids and supercooled liquids at analogous conditions. The effects of species-disorder on the collective properties of binary crystals are also discussed.

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BACKGROUND: Mantle cell lymphoma accounts for 6% of all B-cell lymphomas and is generally incurable. It is characterized by the translocation t(11;14) leading to cyclin D1 over-expression. Cyclin D1 is downstream of the mammalian target of rapamycin threonine kinase and can be effectively blocked by mammalian target of rapamycin inhibitors. We set out to examine the single agent activity of the orally available mammalian target of rapamycin inhibitor everolimus in a prospective, multicenter trial in patients with relapsed or refractory mantle cell lymphoma (NCT00516412). DESIGN AND METHODS: Eligible patients who had received a maximum of three prior lines of chemotherapy were given everolimus 10 mg for 28 days (one cycle) for a total of six cycles or until disease progression. The primary endpoint was the best objective response. Adverse reactions, progression-free survival and molecular response were secondary endpoints. RESULTS: Thirty-six patients (35 evaluable) were enrolled and treatment was generally well tolerated with Common Terminology Criteria grade ≥ 3 adverse events (>5%) including anemia (11%), thrombocytopenia (11%) and neutropenia (8%). The overall response rate was 20% (95% CI: 8-37%) with two complete remissions and five partial responses; 49% of the patients had stable disease. At a median follow-up of 6 months, the median progression-free survival was 5.5 months (95% CI: 2.8-8.2) overall and 17.0 (6.4-23.3) months for 18 patients who received six or more cycles of treatment. Three patients achieved a lasting complete molecular response, as assessed by polymerase chain reaction analysis of peripheral blood. CONCLUSIONS: Everolimus as a single agent is well tolerated and has anti-lymphoma activity in relapsed or refractory mantle cell lymphoma. Further studies of everolimus in combination with chemotherapy or as a single agent for maintenance treatment are warranted.

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BACKGROUND AND OBJECTIVES: Donor cytomegalovirus seropositivity was reported to improve leukemia outcomes in HLA-A2 identical hematopoietic cell transplant (HCT) recipients, due to a possible cross-reactivity of donor HLA-A2-restricted CMV-specific T cells with minor histocompatibility (H) antigen of recipient cells. This study analyzed the role of donor CMV serostatus and HLA-A2 status on leukemia outcomes in a large population of HLA-identical HCT recipients. DESIGN AND METHODS: Leukemia patients transplanted between 1992 and 2003 at the Fred Hutchinson Cancer Research Center were categorized as standard risk [leukemia first remission, chronic myeloid leukemia in chronic phase (CML-CP)] and high risk (advanced disease) patients. Time-to-event analysis was used to evaluate the risk of relapse and death associated with HLA-A2 status and donor CMV serostatus. RESULTS: In standard risk patients, acute leukemia (p<0.001) and sex mismatch (female to male, p=0.004)) independently increased the risk of death, while acute leukemia increased the risk of relapse (p<0.001). In high risk patients acute leukemia (p=0.01), recipient age > or = 40 (p=0.005) and herpes simplex virus (HSV) seropositivity (p<0.001) significantly increased the risk death; HSV seropositivity (p=0.006) increased the risk of relapse. Donor CMV serostatus had no significant effect on mortality or relapse in any HLA group. INTERPRETATION AND CONCLUSION: This epidemiological study did not confirm the previously reported effect of donor CMV serostatus on the outcomes of leukemia in HLA-A2-identical HCT recipients. Addressing the question of cross-reactivity of HLA-A2-restricted CMV-specific T cells with minor H antigens in a clinical study would require knowledge of the patient's minor H antigen genotype. However, because of the unbalanced distribution of HLA-A2-restricted minor H antigens in the population and their incomplete identification, this question might be more appropriately evaluated in in vitro experiments than in a clinical study.

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[cat] En el context dels mercats a dues bandes, considerem, en primer lloc, que els jugadors poden escollir on dur a terme les seves transaccions. Mostrem que el joc corresponent a aquesta situació, que es representa pel màxim d’un conjunt finit de jocs d’assignació, pot ser un joc no equilibrat. Aleshores proporcionem condicions per a l’equilibri del joc i, per aquest cas, analitzem algunes propietats del core del joc. En segon lloc, considerem que els jugadors poden fer transaccions en diversos mercats simultàniament i, llavors, sumar els guanys obtinguts. El joc corresponent, representat per la suma d’un conjunt finit de jocs d’assignació, és equilibrat. A més a més, sota certes condicions, la suma dels cores dels dos jocs d’assignació coincideix amb el core del joc suma.

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OBJECTIVE: To assess how intrahepatic fat and insulin resistance relate to daily fructose and energy intake during short-term overfeeding in healthy subjects. DESIGN AND METHODS: The analysis of the data collected in several studies in which fasting hepatic glucose production (HGP), hepatic insulin sensitivity index (HISI), and intrahepatocellular lipids (IHCL) had been measured after both 6-7 days on a weight-maintenance diet (control, C; n = 55) and 6-7 days of overfeeding with 1.5 (F1.5, n = 7), 3 (F3, n = 17), or 4 g fructose/kg/day (F4, n = 10), with 3 g glucose/kg/day (G3, n = 11), or with 30% excess energy as saturated fat (fat30%, n = 10). RESULTS: F3, F4, G3, and fat30% all significantly increased IHCL, respectively by 113 ± 86, 102 ± 115, 59 ± 92, and 90 ± 74% as compared to C (all P < 0.05). F4 and G3 increased HGP by 16 ± 10 and 8 ± 11% (both P < 0.05), and F3 and F4 significantly decreased HISI by 20 ± 22 and 19 ± 14% (both P < 0.01). In contrast, there was no significant effect of fat30% on HGP or HISI. CONCLUSIONS: Short-term overfeeding with fructose or glucose decreases hepatic insulin sensitivity and increases hepatic fat content. This indicates short-term regulation of hepatic glucose metabolism by simple carbohydrates.

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OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis.

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OBJECTIVE: Pancreatic beta-cells exposed to proinflammatory cytokines display alterations in gene expression resulting in defective insulin secretion and apoptosis. MicroRNAs are small noncoding RNAs emerging as key regulators of gene expression. Here, we evaluated the contribution of microRNAs to cytokine-mediated beta-cell cytotoxicity. RESEARCH DESIGN AND METHODS: We used global microarray profiling and real-time PCR analysis to detect changes in microRNA expression in beta-cells exposed to cytokines and in islets of pre-diabetic NOD mice. We assessed the involvement of the microRNAs affected in cytokine-mediated beta-cell failure by modifying their expression in insulin-secreting MIN6 cells. RESULTS: We found that IL-1beta and TNF-alpha induce the expression of miR-21, miR-34a, and miR-146a both in MIN6 cells and human pancreatic islets. We further show an increase of these microRNAs in islets of NOD mice during development of pre-diabetic insulitis. Blocking miR-21, miR-34a, or miR-146a function using antisense molecules did not restore insulin-promoter activity but prevented the reduction in glucose-induced insulin secretion observed upon IL-1beta exposure. Moreover, anti-miR-34a and anti-miR-146a treatment protected MIN6 cells from cytokine-triggered cell death. CONCLUSIONS: Our data identify miR-21, miR-34a, and miR-146a as novel players in beta-cell failure elicited in vitro and in vivo by proinflammatory cytokines, notably during the development of peri-insulitis that precedes overt diabetes in NOD mice.

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OBJECTIVE: To compare the metabolic effects of fructose in healthy male and female subjects. RESEARCH DESIGN AND METHODS: Fasting metabolic profile and hepatic insulin sensitivity were assessed by means of a hyperglycemic clamp in 16 healthy young male and female subjects after a 6-day fructose overfeeding. RESULTS: Fructose overfeeding increased fasting triglyceride concentrations by 71 vs. 16% in male vs. female subjects, respectively (P &lt; 0.05). Endogenous glucose production was increased by 12%, alanine aminotransferase concentration was increased by 38%, and fasting insulin concentrations were increased by 14% after fructose overfeeding in male subjects (all P &lt; 0.05) but were not significantly altered in female subjects. Fasting plasma free fatty acids and lipid oxidation were inhibited by fructose in male but not in female subjects. CONCLUSIONS: Short-term fructose overfeeding produces hypertriglyceridemia and hepatic insulin resistance in men, but these effects are markedly blunted in healthy young women.

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OBJECTIVE: This systematic review and meta-analysis of randomized controlled trials (RCTs) assesses the effect of pharmacist care on cardiovascular disease (CVD) risk factors among outpatients with diabetes. RESEARCH DESIGN AND METHODS: MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were searched. Pharmacist interventions were classified, and a meta-analysis of mean changes of blood pressure (BP), total cholesterol (TC), LDL cholesterol, HDL cholesterol, and BMI was performed using random-effects models. RESULTS: The meta-analysis included 15 RCTs (9,111 outpatients) in which interventions were conducted exclusively by pharmacists in 8 studies and in collaboration with physicians, nurses, dietitians, or physical therapists in 7 studies. Pharmacist interventions included medication management, educational interventions, feedback to physicians, measurement of CVD risk factors, or patient-reminder systems. Compared with usual care, pharmacist care was associated with significant reductions for systolic BP (12 studies with 1,894 patients; -6.2 mmHg [95% CI -7.8 to -4.6]); diastolic BP (9 studies with 1,496 patients; -4.5 mmHg [-6.2 to -2.8]); TC (8 studies with 1,280 patients; -15.2 mg/dL [-24.7 to -5.7]); LDL cholesterol (9 studies with 8,084 patients; -11.7 mg/dL [-15.8 to -7.6]); and BMI (5 studies with 751 patients; -0.9 kg/m(2) [-1.7 to -0.1]). Pharmacist care was not associated with a significant change in HDL cholesterol (6 studies with 826 patients; 0.2 mg/dL [-1.9 to 2.4]). CONCLUSIONS: This meta-analysis supports pharmacist interventions-alone or in collaboration with other health care professionals-to improve major CVD risk factors among outpatients with diabetes.

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OBJECTIVES: In 2002, the canton of Fribourg, Switzerland, implemented a coordinated pharmaceutical care service in nursing homes to promote rational drug use. In the context of this service, a project was conducted to develop recommendations for the pharmacological management of behavioral and psychological symptoms of dementia (BPSD) in nursing home residents. DESIGN AND METHODS: Selected evidence-based guidelines and meta-analysis sources related to the management of depression, insomnia, and agitation in dementia patients were systematically searched and evaluated. Evidence and controversies regarding the pharmacological treatment of the most common BPSD symptoms were reviewed, and treatment algorithms were developed. RESULTS: Ten evidence-based guidelines and meta-analyses for BPSD management were identified, with none specifically addressing issues related to nursing home residents. Based on this literature, recommendations were developed for the practice of pharmacological management of depression, sleep disturbances, and agitation in nursing home residents. For depression, SSRIs are considered the first choice if an antidepressant is required. No clear evidence has been found for sleep disturbances; the underlying conditions need to be investigated closely before the introduction of any drug therapy. Many drugs have been investigated for the treatment of agitation, and if necessary, antipsychotics could be used, although they have significant side effects. Several areas of uncertainty were identified, such as the current controversy about typical and atypical antipsychotic use or the appropriateness of cholinesterase inhibitors for controlling agitation. Treatment algorithms were presented to general practitioners, pharmacists, and medical directors of nursing homes in the canton of Fribourg, and will now be implemented progressively, using educational sessions, pharmaceutical counseling, and monitoring. CONCLUSION: Based on existing evidence-based studies, recommendations were developed for the practice of pharmacological management of depression, sleep disturbances, and agitation in nursing home residents. It should be further studied whether these algorithms implemented through pharmaceutical care services will improve psychotropic drug prescriptions and prevent drug-related problems in nursing home residents

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OBJECTIVES: The diagnosis of pheochromocytoma relies on the measurement of plasma free metanephrines assay whose reliability has been considerably improved by ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Here we report an analytical interference occurring between 4-hydroxy-3-methoxymethamphetamine (HMMA), a metabolite of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"), and normetanephrine (NMN) since they share a common pharmacophore resulting in the same product ion after fragmentation. DESIGN AND METHODS: Synthetic HMMA was spiked into plasma samples containing various concentrations of NMN and the intensity of the interference was determined by UPLC-MS/MS before and after improvement of the analytical method. RESULTS: Using a careful adjustment of chromatographic conditions including the change of the UPLC analytical column, we were able to distinguish both compounds. HMMA interference for NMN determination should be seriously considered since MDMA activates the sympathetic nervous system and if confounded with NMN may lead to false-positive tests when performing a differential diagnostic of pheochromocytoma.

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OBJECTIVE: To assess the incidence and epidemiological pattern of respiratory viruses in HIV-infected patients and to evaluate their potential clinical impact. DESIGN AND METHODS: A prospective population-based cohort study was conducted at three Swiss university hospitals. Study participants were HIV-infected patients who underwent a bronchoalveolar lavage to rule out an opportunistic event. All bronchoalveolar lavage specimens were screened using a set of real-time reverse transcriptase-polymerase chain reaction assays targeting 17 different respiratory viruses. RESULTS: Between November 2003 and November 2006, 59 bronchoalveolar episodes from 55 HIV-infected patients were analysed. Eleven of 59 episodes (18.6%) were positive for at least one respiratory virus. Coronavirus OC43 was identified in three cases (27.3%) followed by influenza A in two (18.2%). Parainfluenza virus (PIV) 2, PIV 3, PIV 4, bocavirus, human rhinovirus A and human metapneumovirus were each identified in one case (9%). In the majority of these cases (63.6%) no other concomitant microorganism was isolated. CONCLUSIONS: Clinical investigation of respiratory viral infections in HIV-infected patients should not be restricted to prototype viruses and also need to target all the different family of viruses as it seems likely that these viruses contribute to pulmonary complications and morbidity in this population.

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ABSTRACT : Objective: to compare the metabolic effects of fructose in healthy males and females Research Design And Methods: Fasting metabolic profile and hepatic insulin sensitivity were assessed by means of a hyperglycemic clamp in 16 healthy young males and female subjects after a 6-day fructose overfeeding Results: Fructose overfeeding increased fasting triglyceride concentrations by 71 % in males vs 16% in females (p<0.05). Endogenous glucose production was increased by 12%, alanin aminotransferase concentration was increased by 38%, and fasting insulin concentrations was increased by 14% after fructose overfeeding in males (all p<0.05), but were not significantly altered in females. Fasting plasma free fatty acids and lipid oxidation were inhibited by fructose in males, but not in females Conclusions: Short term fructose overfeeding produces hypertriglyceridemia and hepatic insulin resistance in males, but these effects are markedly blunted in healthy young females. Rapport de synthèse : Objectif : De récentes études ont démontré que l'ingestion de hautes doses de fructose modifie certains paramètres métaboliques. Peu d'entre elles se sont cependant intéressées à déterminer si les effets métaboliques du fructose étaient dépendants du sexe. L'objectif de la présente étude était donc de comparer les effets du fructose chez des volontaires sains, hommes et femmes. Méthode : Le profil métabolique à jeun et la sensibilité hépatique à l'insuline ont été déterminés au moyen d'un clamp hyperglycémique chez un collectif de 16 jeunes hommes et femmes après une période de 6 jours de régime riche en fructose. Résultats : La concentration de triglycérides à jeun après ce régime était augmentée de 71% chez les hommes contre 16% chez les femmes (p<0.05). La production endogène de glucose était augmentée de 12%, l'alanine aminotransférase de 38% et la concentration d'insuline à jeun de 14% chez les hommes (p<0.05 pour tous). Chez les femmes, ces paramètres n'étaient au contraire pas significativement modifiés. L'oxydation des acides gras libres et des lipides à jeun était inhibée par le fructose chez les hommes, mais pas chez les femmes. Conclusion : Ces résultats indiquent qu'une suralimentation de courte durée en fructose induit chez l'homme une hypertriglycéridémie et une résistance hépatique à l'insuline, alors que chez la femme jeune, ces effets sont nettement atténués. Il reste à éclaircir de manière plus approfondie les mécanismes sous-tendant ces différences.

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In the administration, planning, design, and maintenance of road systems, transportation professionals often need to choose between alternatives, justify decisions, evaluate tradeoffs, determine how much to spend, set priorities, assess how well the network meets traveler needs, and communicate the basis for their actions to others. A variety of technical guidelines, tools, and methods have been developed to help with these activities. Such work aids include design criteria guidelines, design exception analysis methods, needs studies, revenue allocation schemes, regional planning guides, designation of minimum standards, sufficiency ratings, management systems, point based systems to determine eligibility for paving, functional classification, and bridge ratings. While such tools play valuable roles, they also manifest a number of deficiencies and are poorly integrated. Design guides tell what solutions MAY be used, they aren't oriented towards helping find which one SHOULD be used. Design exception methods help justify deviation from design guide requirements but omit consideration of important factors. Resource distribution is too often based on dividing up what's available rather than helping determine how much should be spent. Point systems serve well as procedural tools but are employed primarily to justify decisions that have already been made. In addition, the tools aren't very scalable: a system level method of analysis seldom works at the project level and vice versa. In conjunction with the issues cited above, the operation and financing of the road and highway system is often the subject of criticisms that raise fundamental questions: What is the best way to determine how much money should be spent on a city or a county's road network? Is the size and quality of the rural road system appropriate? Is too much or too little money spent on road work? What parts of the system should be upgraded and in what sequence? Do truckers receive a hidden subsidy from other motorists? Do transportation professions evaluate road situations from too narrow of a perspective? In considering the issues and questions the author concluded that it would be of value if one could identify and develop a new method that would overcome the shortcomings of existing methods, be scalable, be capable of being understood by the general public, and utilize a broad viewpoint. After trying out a number of concepts, it appeared that a good approach would be to view the road network as a sub-component of a much larger system that also includes vehicles, people, goods-in-transit, and all the ancillary items needed to make the system function. Highway investment decisions could then be made on the basis of how they affect the total cost of operating the total system. A concept, named the "Total Cost of Transportation" method, was then developed and tested. The concept rests on four key principles: 1) that roads are but one sub-system of a much larger 'Road Based Transportation System', 2) that the size and activity level of the overall system are determined by market forces, 3) that the sum of everything expended, consumed, given up, or permanently reserved in building the system and generating the activity that results from the market forces represents the total cost of transportation, and 4) that the economic purpose of making road improvements is to minimize that total cost. To test the practical value of the theory, a special database and spreadsheet model of Iowa's county road network was developed. This involved creating a physical model to represent the size, characteristics, activity levels, and the rates at which the activities take place, developing a companion economic cost model, then using the two in tandem to explore a variety of issues. Ultimately, the theory and model proved capable of being used in full system, partial system, single segment, project, and general design guide levels of analysis. The method appeared to be capable of remedying many of the existing work method defects and to answer society's transportation questions from a new perspective.

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Estudi de l’eficiència aerodinàmica de les carrosseries de vehicles pesants de cara a reduir el consum de combustible en autocars de llarg trajecte. L’estudi es basa en tres aspectes: validació del programa de simulació, estudi aerodinàmic de diferents carrosseries d’autocar de mercat i estudi aerodinàmic de diferents complements