Base de dados : MEDLINE
Pesquisa : G01.374.618 [Categoria DeCS]
Referências encontradas : 3302 [refinar]
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  1 / 3302 MEDLINE  
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PMID:28662053
Autor:Jin LQ; Ling M; Yue W
Endereço:State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, China.
Título:Tire-road friction estimation and traction control strategy for motorized electric vehicle.
Fonte:PLoS One; 12(6):e0179526, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:In this paper, an optimal longitudinal slip ratio system for real-time identification of electric vehicle (EV) with motored wheels is proposed based on the adhesion between tire and road surface. First and foremost, the optimal longitudinal slip rate torque control can be identified in real time by calculating the derivative and slip rate of the adhesion coefficient. Secondly, the vehicle speed estimation method is also brought. Thirdly, an ideal vehicle simulation model is proposed to verify the algorithm with simulation, and we find that the slip ratio corresponds to the detection of the adhesion limit in real time. Finally, the proposed strategy is applied to traction control system (TCS). The results showed that the method can effectively identify the state of wheel and calculate the optimal slip ratio without wheel speed sensor; in the meantime, it can improve the accelerated stability of electric vehicle with traction control system (TCS).
Tipo de publicação: JOURNAL ARTICLE


  2 / 3302 MEDLINE  
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PMID:28570138
Autor:Cornish L
Endereço:Tissue Viability Specialist, St. Margaret's Hospice, Somerset.
Título:The use of prophylactic dressings in the prevention of pressure ulcers: a literature review.
Fonte:Br J Community Nurs; 22(Sup6):S26-S32, 2017 Jun 02.
ISSN:1462-4753
País de publicação:England
Idioma:eng
Resumo:Pressure ulcers pose a significant burden to both patients and health care resources. There are an increasing number of studies that have examined the use of prophylactic dressings, and their ability to redistribute pressure and protect the skin from shear and friction damage. This literature review examines six studies conducted on this controversial subject. Brindle and Wegelin ( 2012 ; Chaiken, 2012 ; Cubit et al, 2012 ; Santamaria et al, 2012) all examined the role of dressings to prevent pressure ulcers, and Call et al (2013a ; 2013b ), conducted in vitro research into the mode of dressings. Current research suggests that while further research is required, the use of prophylactic dressings have a place alongside standard measures, in helping to prevent pressure, shear and friction damage.
Tipo de publicação: JOURNAL ARTICLE; REVIEW


  3 / 3302 MEDLINE  
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PMID:27987761
Autor:Aminzahed I; Mashhadi MM; Sereshk MRV
Endereço:Department of Mechanical Engineering, University of Tehran, Tehran, Iran. Electronic address: iaminzahed@ut.ac.ir.
Título:Investigation of holder pressure and size effects in micro deep drawing of rectangular work pieces driven by piezoelectric actuator.
Fonte:Mater Sci Eng C Mater Biol Appl; 71:685-689, 2017 Feb 01.
ISSN:1873-0191
País de publicação:Netherlands
Idioma:eng
Resumo:Micro forming is a manufacturing process to fabricate micro parts with high quality and a cost effective manner. Deep drawing could be a favorable method for production of complicated parts in macro and micro sizes. In this paper piezoelectric actuator is used as a novel approach in the field of micro manufacturing. Also, in current work, investigations are conducted with four rectangular punches and blanks with various thicknesses. Blank holder pressure effects on thickness distributions, punch force, and springback are studied. According to the results of this work, increasing of blank holder pressure in scaled deep drawing, in contrast to thickness of drawn part, leads to decrease in the punch forces and springback. Furthermore, it is shown that in micro deep drawing, the effects of holder pressure on mentioned parameters can be ignored.
Tipo de publicação: JOURNAL ARTICLE


  4 / 3302 MEDLINE  
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PMID:27987740
Autor:Cui W; Qin G; Duan J; Wang H
Endereço:Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China.
Título:A graded nano-TiN coating on biomedical Ti alloy: Low friction coefficient, good bonding and biocompatibility.
Fonte:Mater Sci Eng C Mater Biol Appl; 71:520-528, 2017 Feb 01.
ISSN:1873-0191
País de publicação:Netherlands
Idioma:eng
Resumo:In order to solve wear resistance of Ti alloy biomaterials, the concept of a graded nano-TiN coating has been proposed. The coating was prepared on Ti-6Al-4V bio-alloy by DC reactive magnetron sputtering. The wear performance of the coated specimens was measured in Hank's solution under the load of 10N, and the biocompatibility was evaluated according to ISO-10993-4 standard. The results show that the gradient coating exhibits a gradual change in compositions and microstructures along the direction of film growth. Nano-TiN with the size of several to dozens nanometers and Ti N transitional phase with variable composition form a graded composite structure, which significantly improves adhesion strength (L =80N, L =120N), hardness (21GPa) and anti-wear performance (6.2×10 mm /Nm). The excellent bonding and wear resistance result from a good match of mechanical properties at substrate/coating interface and the strengthening and toughening effects of the nanocrystalline composite. The nano-TiN coating has also been proved to have good biocompatibility through in-vitro cytotoxicity, hemocompatibility and general toxicity tests. And thus, the proposed graded nano-TiN coating is a good candidate improving wear resistance of many implant medical devices.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Coated Materials, Biocompatible); 12743-70-3 (titanium alloy (TiAl6V4)); 6RW464FEFF (titanium nitride); D1JT611TNE (Titanium)


  5 / 3302 MEDLINE  
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PMID:27987696
Autor:Amanov A; Lee SW; Pyun YS
Endereço:Department of Mechanical Engineering, Sun Moon University, Asan 31460, South Korea. Electronic address: aamanov@outlook.com.
Título:Low friction and high strength of 316L stainless steel tubing for biomedical applications.
Fonte:Mater Sci Eng C Mater Biol Appl; 71:176-185, 2017 Feb 01.
ISSN:1873-0191
País de publicação:Netherlands
Idioma:eng
Resumo:We propose herein a nondestructive surface modification technique called ultrasonic nanocrystalline surface modification (UNSM) to increase the strength and to improve the tribological performance of 316L stainless steel (SS) tubing. Nanocrystallization along nearly the complete tube thickness of 200µm was achieved by UNSM technique that was confirmed by electron backscatter diffraction (EBSD). Nano-hardness of the untreated and UNSM-treated specimens was measured using a nanoindentation. Results revealed that a substantial increase in hardness was obtained for the UNSM-treated specimen that may be attributed to the nanocrystallization and refined grains. Stress-strain behavior of the untreated and UNSM-treated specimens was assessed by a 3-point bending test. It was found that the UNSM-treated specimen exhibited a much higher strength than that of the untreated specimen. In addition, the tribological behavior of the untreated and UNSM-treated specimens with an outer diameter (OD) of 1.6mm and an inner diameter (ID) of 1.2mm was investigated using a cylinder-on-cylinder (crossed tubes of equal radius) tribo-tester against itself under dry conditions at ambient temperature. The friction coefficient and wear resistance of the UNSM-treated specimen were remarkably improved compared to that of the untreated specimen. The significant increase in hardness after UNSM treatment is responsible for the improved friction coefficient and wear resistance of the tubing. Thus, the UNSM technique was found to be beneficial to improving the mechanical and tribological properties of 316L SS tubing for various potential biomedical applications, in particular for coronary artery stents.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:12597-68-1 (Stainless Steel)


  6 / 3302 MEDLINE  
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PMID:28129271
Autor:Kandemir U; Herfat S; Herzog M; Viscogliosi P; Pekmezci M
Endereço:Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA.
Título:Fatigue Failure in Extra-Articular Proximal Tibia Fractures: Locking Intramedullary Nail Versus Double Locking Plates-A Biomechanical Study.
Fonte:J Orthop Trauma; 31(2):e49-e54, 2017 Feb.
ISSN:1531-2291
País de publicação:United States
Idioma:eng
Resumo:OBJECTIVES: The goal of this study is to compare the fatigue strength of a locking intramedullary nail (LN) construct with a double locking plate (DLP) construct in comminuted proximal extra-articular tibia fractures. METHODS: Eight pairs of fresh frozen cadaveric tibias with low bone mineral density [age: 80 ± 7 (SD) years, T-score: -2.3 ± 1.2] were used. One tibia from each pair was fixed with LN, whereas the contralateral side was fixed with DLP for complex extra-articular multifragmentary metaphyseal fractures (simulating OTA 41-A3.3). Specimens were cyclically loaded under compression simulating single-leg stance by staircase method out to 260,000 cycles. Every 2500 cycles, localized gap displacements were measured with a 3D motion tracking system, and x-ray images of the proximal tibia were acquired. To allow for mechanical settling, initial metrics were calculated at 2500 cycles. The 2 groups were compared regarding initial construct stiffness, initial medial and lateral gap displacements, stiffness at 30,000 cycles, medial and lateral gap displacements at 30,000 cycles, failure load, number of cycles to failure, and failure mode. Failure metrics were reported for initial and catastrophic failures. RESULTS: DLP constructs exhibited higher initial stiffness and stiffness at 30,000 cycles compared with LN constructs (P < 0.03). There were no significant differences between groups for loads at failure or cycles to failure. CONCLUSIONS: For the fixation of extra-articular proximal tibia fractures, a LN provides a similar fatigue performance to double locked plates. The locked nail could be safely used for fixation of proximal tibia fractures with the advantage of limited extramedullary soft tissue damage.
Tipo de publicação: COMPARATIVE STUDY; EVALUATION STUDIES; JOURNAL ARTICLE


  7 / 3302 MEDLINE  
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PMID:28208081
Autor:Raj A; Wang M; Liu C; Ali L; Karlsson NG; Claesson PM; Dedinaite A
Endereço:KTH Royal Institute of Technology, School of Chemical Sciences and Engineering, Department of Chemistry, Surface and Corrosion Science, Drottning Kristinas Väg 51, SE-10044 Stockholm, Sweden. Electronic address: rajaka@kth.se.
Título:Molecular synergy in biolubrication: The role of cartilage oligomeric matrix protein (COMP) in surface-structuring of lubricin.
Fonte:J Colloid Interface Sci; 495:200-206, 2017 06 01.
ISSN:1095-7103
País de publicação:United States
Idioma:eng
Resumo:HYPOTHESIS: Synovial surfaces are lubricated by biomolecular aggregates that act in synergy, and lubricin is one key biolubricant. Its molecular structure allows extensive hydration and this is conducive to its lubrication performance. However, in order to fullfil its lubrication function it needs to be anchored and oriented on the surface in a proper way. We suggest that cartilage oligomeric matrix protein (COMP) is one of the biomolecules that promotes anchoring of lubricin in a fashion that facilitates lubrication. EXPERIMENTS: Weakly hydrophobic poly(methyl methacrylate) (PMMA) surfaces were coated by COMP and lubricin, individually and in combinations. Adsorption was investigated using a quartz crystal microbalance, and friction between the biopolymer-coated surfaces was determined by employing the atomic force microscope-colloidal probe technique. FINDINGS: It was found that COMP facilitated firm directed attachment of lubricin in a manner that resulted in low friction forces, significantly lower than what was achieved when lubricin was directly adsorbed to PMMA. Evidently, COMP provides means for lubricin to attach strongly and in a favourable conformation for efficient lubrication of this surface. We suggest that our findings can be extrapolated to cartilage surfaces, where co-localization of COMP and lubricin has been demonstrated.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
Nome de substância:0 (Cartilage Oligomeric Matrix Protein); 0 (Glycoproteins); 0 (lubricin); 9004-61-9 (Hyaluronic Acid); 9011-14-7 (Polymethyl Methacrylate)


  8 / 3302 MEDLINE  
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PMID:28666116
Autor:Mandadapu KK; Hurley JH
Endereço:Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Electronic address: kranthi@berkeley.edu.
Título:Friction at the BAR Leads to Membrane Breakup.
Fonte:Cell; 170(1):14-16, 2017 06 29.
ISSN:1097-4172
País de publicação:United States
Idioma:eng
Resumo:A long-standing question in cell biology is how endocytic vesicles and tubules detach from the plasma membrane in the absence of constriction by dynamin. In this issue of Cell, Simunovic et al. describe an elegant biophysical model in which friction between lipids and BAR-domain proteins drives the scission of elongating membrane tubules.
Tipo de publicação: JOURNAL ARTICLE; COMMENT
Nome de substância:EC 3.6.5.5 (Dynamins)


  9 / 3302 MEDLINE  
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PMID:28648660
Autor:Simunovic M; Manneville JB; Renard HF; Evergren E; Raghunathan K; Bhatia D; Kenworthy AK; Voth GA; Prost J; McMahon HT; Johannes L; Bassereau P; Callan-Jones A
Endereço:Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC University Paris 06, 75005 Paris, France; Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago, 5735 S. El
Título:Friction Mediates Scission of Tubular Membranes Scaffolded by BAR Proteins.
Fonte:Cell; 170(1):172-184.e11, 2017 Jun 29.
ISSN:1097-4172
País de publicação:United States
Idioma:eng
Resumo:Membrane scission is essential for intracellular trafficking. While BAR domain proteins such as endophilin have been reported in dynamin-independent scission of tubular membrane necks, the cutting mechanism has yet to be deciphered. Here, we combine a theoretical model, in vitro, and in vivo experiments revealing how protein scaffolds may cut tubular membranes. We demonstrate that the protein scaffold bound to the underlying tube creates a frictional barrier for lipid diffusion; tube elongation thus builds local membrane tension until the membrane undergoes scission through lysis. We call this mechanism friction-driven scission (FDS). In cells, motors pull tubes, particularly during endocytosis. Through reconstitution, we show that motors not only can pull out and extend protein-scaffolded tubes but also can cut them by FDS. FDS is generic, operating even in the absence of amphipathic helices in the BAR domain, and could in principle apply to any high-friction protein and membrane assembly.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Membrane Proteins); 0 (centaurin beta2, human); EC 2.3.- (Acyltransferases); EC 2.3.1.52 (2-acylglycerophosphate acyltransferase)


  10 / 3302 MEDLINE  
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PMID:28644849
Autor:Park CH; Li XR; Zhao Y; Jia RL; Hur JS
Endereço:Korean Lichen Research Institute, Sunchon National University, 255 Jungang-Ro, Suncheon, Korea.
Título:Rapid development of cyanobacterial crust in the field for combating desertification.
Fonte:PLoS One; 12(6):e0179903, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:Desertification is currently a major concern, and vast regions have already been devastated in the arid zones of many countries. Combined application of cyanobacteria with soil fixing chemicals is a novel method of restoring desertified areas. Three cyanobacteria, Nostoc sp. Vaucher ex Bornet & Flahault, Phormidium sp. Kützing ex Gomont and Scytonema arcangeli Bornet ex Flahault were isolated and tested in this study. Tacki-SprayTM (TKS7), which consists of bio-polysaccharides and tackifiers, was used as a soil fixing agent. In addition, superabsorbent polymer (SAP) was applied to the soil as a water-holding material and nutrient supplement. Application of cyanobacteria with superabsorbent polymer and TKS7 (CST) remarkably improved macro-aggregate stability against water and erodibility against wind after 12 months of inoculation when compared to the control soil. The mean weight diameter and threshold friction velocity of the CST treated soil were found to be 75% and 88% of those of the approximately 20-year-old natural cyanobacterial crust (N-BSC), respectively, while these values were 68% and 73% of those of the N-BSC soil after a single treatment of cyanobacteria alone (CY). Interestingly, biological activities of CST were similar to those of CY. Total carbohydrate contents, cyanobacterial biomass, microbial biomass, soil respiration, carbon fixation and effective quantum yield of CST treated soil were enhanced by 50-100% of the N-BSC, while those of control soil were negligible. Our results suggest that combined application of cyanobacteria with soil fixing chemicals can rapidly develop cyanobacterial crust formation in the field within 12 months. The physical properties and biological activities of the inoculated cyanobacterial crust were stable during the study period. The novel method presented herein serves as another approach for combating desertification in arid regions.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Carbohydrates); 0 (Polymers); 0 (Polysaccharides); 0 (Soil); 059QF0KO0R (Water); 7440-44-0 (Carbon)



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