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排序方式: 共有863条查询结果,搜索用时 15 毫秒
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153.
Jorge Pascual-Fernndez Alejandro Fernndez-Montero Alfredo Crdova-Martínez Diego Pastor Alejandro Martínez-Rodríguez Enrique Roche 《International journal of molecular sciences》2020,21(22)
Aging is associated with sarcopenia. The loss of strength results in decreased muscle mass and motor function. This process accelerates the progressive muscle deterioration observed in older adults, favoring the presence of debilitating pathologies. In addition, sarcopenia leads to a decrease in quality of life, significantly affecting self-sufficiency. Altogether, these results in an increase in economic resources from the National Health Systems devoted to mitigating this problem in the elderly, particularly in developed countries. Different etiological determinants are involved in the progression of the disease, including: neurological factors, endocrine alterations, as well as nutritional and lifestyle changes related to the adoption of more sedentary habits. Molecular and cellular mechanisms have not been clearly characterized, resulting in the absence of an effective treatment for sarcopenia. Nevertheless, physical activity seems to be the sole strategy to delay sarcopenia and its symptoms. The present review intends to bring together the data explaining how physical activity modulates at a molecular and cellular level all factors that predispose or favor the progression of this deteriorating pathology. 相似文献
154.
Hugo Uvegi Piyush Chaunsali Brian Traynor Elsa Olivetti 《Journal of the American Ceramic Society》2019,102(12):7678-7688
An untapped source of amorphous SiO2, industrially generated Indian biomass ash (SA)—90% amorphous, with composition of ~60% SiO2 and ~20% unburnt carbon—can be used to produce cementitious and alkali-activated binders. This study reports dissolution of amorphous Si from SA in 0.5 mol/L and 1 mol/L aqueous NaOH, with and without added Ca(OH)2, at SA:Ca(OH)2 wt% ratios of 100:0, 87.5:12.5, and 82.5:17.5. Monitoring of elemental dissolution and subsequent/simultaneous product uptake by ICP-OES offers an effective process for evaluating utility of industrial wastes in binder-based systems. After 28 days in solution, up to 68% of total Si is dissolved from SA in 1 mol/L NaOH, with values as much as 38% lower in the presence of Ca(OH)2, due to the formation of tobermorite-like C-S-H. FTIR, 29Si MAS-NMR, and XRD are used to characterize solid reaction products and observe reaction progress. Product chemistries calculated from ICP-OES results and verified by selective dissolution in EDTA/NaOH—namely, Ca/Si of 0.6-1 and Na adsorption of 1-2 mmol/g—are found to be consistent with those indicated by aforementioned techniques. This indicates the efficacy of ICP-OES in estimating product chemistry via such a methodology. 相似文献
155.
Requirements Engineering - Traceability links recovery (TLR) has been a topic of interest for many years. However, TLR approaches are based on the latent semantics of the software artifacts, and... 相似文献
156.
C. Fernández J. Suardíaz A. Iborra J. A. Pastor B. Alvarez J. M. Fernández 《The International Journal of Advanced Manufacturing Technology》2003,22(5-6):363-373
The aim of the present paper is to report the use of information technologies to control and assure the quality of complex mechanical parts, in this case crankshafts. Three different automated cells are used for inspection purposes using Non Destructive Techniques (NDT): Automated Visual Inspection (AVI), a surface Roughness Measurement System (RMS) and a Dimensional Control System (DCS). Distributed control architecture allows integral quality assessment of the production process of valuable machined components. A suitable software subsystem has been developed for this architecture: a Quality Assessment Subsystem (QUAL), a Tracking Subsystem (TS) and an intelligent production Process Assessment Subsystem (PAS). A prototype has been successfully installed and is under evaluation in a production line belonging to Renault Industrial Vehicles (Spain). 相似文献
157.
Calculation of tool paths for a torus mill on free-form surfaces on five-axis machines with detection and elimination of interference 总被引:3,自引:1,他引:2
Dr Walter Rubio Pierre Lagarrigue Gilles Dessein François Pastor 《The International Journal of Advanced Manufacturing Technology》1998,14(1):13-20
Within the framework of a study carried out in cooperation with the Sapex Company, we sought to develop an overall machining program for free-form surfaces on a 5-axis NC machine tool. This program comprises a certain number of general cases that will then have to be adapted to specific situations. In this paper, we present the algorithms allowing the following cases to be dealt with:Positioning a torus mill at a given point on the surface with automatic search for interference between the end of the tool and the surface.Angular correction or the raising of the tool to avoid interference.Calculation of trajectories for a rolling torus mill on a ruled surface resting on a free-form surface of the NURBS (Non Uniform Rational B-Splines) type.The latter can be broken down into two parts:Seeking the axis position on the adjusted surface.Determination of the tool's point of contact on the freeform surface. 相似文献
158.
MA Menéndez Martínez C Pérez De Oteyza R Muro García A García Cortés JM Pastor Gómez 《Canadian Metallurgical Quarterly》1997,14(8):399-402
OBJECTIVE: To establish the difference between the evolutive clinical categories (CDC/93) of the HIV infection, on the basis of diverse laboratory parameters. MATERIAL AND METHOD: 332 samples of blood, from 118 patients with HIV infection revised every three months from 1986, were studied. Determinations: haematologic, biochemical and immunologic study. Classification in each review by CDC/93 system. Statistical analysis (R-SIGMA) comparing by ANOVA and NEWMANN-KEULS the averages of the laboratory variables in the clinics categories ("A", "B" and "C"). RESULTS: There are very significant laboratory differences (p < 0.01) between the asymptomatic patients ("A") and the AIDS cases ("C"), with important decrease of hemoglobin, platelets, leukocytes, albumin, CD4+ and CD8+ T cells in the "C" category. On the contrary there is a marked increase of erythrocyte sedimentation, triglycerides, immunoglobulin A and beta 2-microglobulin in those patients with AIDS. CONCLUSION: AIDS patients present very significant differences in ten laboratory parameters, compared to the asymptomatic HIV infected patients. The follow up of these parameters may have prognostic value of AIDS evolution and be useful for the therapeutic decision making. 相似文献
159.
Inter‐organizational collaboration is increasingly a topic for studies into accidents and disasters as well as exercises. In this study, which is based on interviews with first responders, we compared perceived collaboration during an exercise with crisis work. The three organizations included in this study—fire department, police and ambulance services—perceived the investigated tunnel exercise completely different, ranging from harmonious interaction to power struggles between commanding officers, fragmented decision‐making and ambiguity. When comparing the exercise with an incident, we found that collaboration was more evident during incidents than in exercises. However, collaboration exercises appear to improve inter‐organizational collaboration by stimulating informal structures, practicing listening and delegating, getting to know one another and learning a common language. 相似文献
160.
Giraldo Fáber D. España Sergio Giraldo William J. Pastor Óscar Krogstie John 《Software Quality Journal》2019,27(3):1239-1269
Software Quality Journal - The model-driven engineering (MDE) paradigm promotes the use of conceptual models in information systems (IS) engineering and research. As engineering products,... 相似文献