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排序方式: 共有1341条查询结果,搜索用时 15 毫秒
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《Sport》2014,30(1):10-18
The number of shoulder surgery is increasing during the last 10 years. Advances in arthroscopic equipment, better imaging and technical progress of modern shoulderarthroplasty systems up to reverse and stemless systems.To gain good results in shoulder surgery it is mandatory to respect accurate imaging for preoperative planning and postoperative control due to softtissue- balancing, the various arrangement and complexity of the shoulder joint and the individual anatomy. Especially shoulderarthroplasty procedures need special knowledge of anatomical structures to avoid problems, intraoperative surprises and eary revisionsurgery.This article should point out adeaquat imaging according to each indication. 相似文献
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Acetyl phosphate is a central metabolite involved in a broad range of versatile cellular functions. Recently it was observed that in Escherichia coli the acetyl phosphate pathway is required for efficient ATP-dependent proteolysis. Deletion of the operon coding for acetyl phosphate metabolism (ΔackApta) results in a very low cytoplasmic level of acetyl phosphate and impaired proteolysis. Here we show that the ΔackApta mutation affects additional components of the protein quality control system. Thus, this deletion is accompanied by a decrease in protein refolding and rescue from aggregates. These results indicate the involvement of the acetyl phosphate pathway in chaperone capabilities, in addition to their effect on proteolysis. 相似文献
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Bingbing Wang Hongming Lou Hongli Xu Junpeng Zhao Qiujun Wang Qiao Shi Yonghong Deng 《RSC advances》2018,8(12):6373
In this work, a novel star-comb copolymer based on poly(d,l-lactide) (PDLLA) macromonomer and poly(ethylene glycol)methyl ether methacrylate (PEGMA) was prepared, and the electrochemical properties were studied, with the aim of using it as a solid polymer electrolyte in lithium ion batteries. The six-arm vinyl functionalized PDLLA macromonomer was synthesized by a ring-opening polymerization (ROP) of d,l-lactide and subsequently an acylation of the hydroxy end-groups. A series of free-standing solid polymer electrolyte membranes from different ratios of PDLLA, PEGMA and LiTFSI were prepared through solvent-free free radical polymerization under UV radiation. The chemical structure of the obtained polymers was confirmed by 1H NMR and FTIR. The as-prepared six-arm star-comb solid polymer electrolytes (PDLLA-SPEs) exhibit good thermal stability with Td5%s of ∼270 °C and low Tgs of −48 to −34 °C. The electrochemical characterization shows that the PDLLA-SPEs possess a wide electrochemical window up to 5.1 V with an optimal ionic conductivity of 9.7 × 10−5 S cm−1 at 60 °C at an EO/Li+ ratio of 16 : 1. Furthermore, the all-solid-state LiFePO4/Li cells display extraordinary cycling and rate performances at 60 °C by curing the PDLLA-SPEs directly on the cathode. These superior properties of the six-arm star-comb PDLLA-SPE make it a promising candidate solid electrolyte for lithium batteries.In this work, a novel star-comb copolymer based on PDLLA macromonomer and PEGMA was prepared, and the electrochemical properties were studied, with the aim of using it as a solid polymer electrolyte in lithium ion batteries. 相似文献
35.
To find the optimal structure of the converging–diverging tube and develop a high-efficiency falling-film evaporator, the heat and mass transfer performances of falling-film evaporation with converging–diverging tubes of different dimensions were studied. The optimal converging–diverging tube was used in falling-film evaporation desorption of the basic aluminum sulfate desulphurization–regeneration solution, and different influential factors on the desorption effect were analyzed. It was found that converging–diverging tubes with large falling-film flow rate performed well in the heat and mass transfer of falling-film evaporation, and their rib height largely affected the heat and mass transfer performances. At the same rib height and rib pitch, the longer the converging segment of the converging–diverging tube was, the better the heat transfer performance was. The evaporation heat transfer coefficient and evaporation mass transfer rate in the optimal converging–diverging tube were 1.6 and 1.38 times larger than the smooth tube, respectively. The optimal converging–diverging tube was used in falling-film evaporation desorption of basic aluminum sulfate desulphurization–regeneration solution, at a perimeter flow rate of 0.114–0.222 kg m−1 s−1, the desorption efficiency inside the tube was up to 94.2%, which was 10.3–10.5% higher than that of the smooth tube. At the inlet sulfur concentration of 0.02–0.1 kmol m−3, the desorption efficiency was up to 94.1%, which was 12.0–16.3% larger than that of the smooth tube. At the heating temperature of 371.15–386.15 K, the desorption efficiency was up to 93.4%, which was 6.7–11.5% larger than that of the smooth tube. Smaller falling-film flow rate, higher sulfur concentration, or higher heating temperature was more constructive to SO2 desorption. Correlations were obtained to predict the mass transfer coefficient and SO2 desorption efficiency. This study develops a new type of falling-film evaporator for SO2 desorption from basic aluminum sulfate desulphurization–regeneration solution and provides a basis for process design and industrial application.The heat and mass transfer performances of falling-film evaporation with converging–diverging tubes of different dimensions were studied. 相似文献
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Enzymatic hydrolysis residues (EHR) from corn stalk are industrial waste from the cellulosic ethanol industry. Lignin was separated as a bio-based polyol from EHR replacing partial petroleum-based polyether polyol to prepare bio-based polyurethane (BPU) foams without any other biomass pretreatment. Single factor experiment and response surface methodology (RSM) were employed to optimize separation conditions and reveal the significant influence of the interaction of conditions on the yield of separated lignin (SL). The effect of SL content (2.5, 5.0, 7.5, 10 and 15%) on the foams morphology and mechanical properties was assessed. Scanning electron microscopy (SEM) results implied that the cell shape was considerably affected by the large SL content, which contributed to an irregular, inhomogeneous, and thick cell wall. An astonishing 9.56 times increase in the compressive modulus and exponential 97.93 times boost in the compressive strength of BPU foams were attributed to the content of 15% SL without any further surface chemical modification. This present paper reports a green, potential and promising method for complete utilization of lignin from EHR in consideration of their abundant supply to greatly enhance the mechanical properties of BPU foams.Enzymatic hydrolysis residues (EHR) from corn stalk are industrial waste from the cellulosic ethanol industry. 相似文献
39.
Bo Liu Jiwen Luo Junxiang Lu Hongbing Deng 《Journal of biomaterials science. Polymer edition》2013,24(5):589-605
Drug-delivery systems, using natural drug carriers, have become increasingly important because of their nontoxicity and biodegradability. In this study, firstly, quaternized carboxymethyl chitosan (QCMC) was intercalated into the interlayer of organic montmorillonite (OMMT) to obtain the QCMC/OMMT nanocomposites, their structure, morphology, and thermal stability were investigated. Next, crosslinked alginate/QCMC/OMMT (AQCOM) microsphere was obtained by crosslinking with CaCl2, and the drug-controlled release behavior was evaluated with bovine serum albumin (BSA) as model drug. The results suggested that, carboxyl groups in alginate and QCMC crosslinked with Ca2+, quaternary ammonium groups in QCMC or OMMT electrostatically interacted with carboxyl groups in alginate, and there was stable three-dimensional network in AQCOM microsphere. The swelling ratio of AQCOM microspheres decreased with the increase of OMMT content, the lowest one was only about 45% compared to the microsphere without OMMT of 197%. Besides, the in vitro release results for BSA indicated that the AQCOM microsphere displayed more excellent encapsulation and controlled release capacities than the microsphere without OMMT. The in vitro active cutaneous anaphylaxis test was carried out on Guinea pigs, which revealed that AQCOM microsphere did not cause anaphylaxis. Therefore, QCMC/OMMT nanocomposites from natural materials are considerably suitable to apply as drug-controlled release carriers. 相似文献
40.
The complete genome sequence of a monopartite begomovirus isolate infecting Creek Premna (Premna serratifolia L.) plants that exhibited leaf curl, vein swelling, and enation symptoms in Nha Trang, Vietnam, was cloned and sequenced. It comprises 2,753 nucleotides (JQ793786) and has a typical organization of begomoviruses DNA-A with AV1 and AV2 open reading frames (ORFs) in the viral-sense strand and AC1, AC2, AC3, AC4 and AC5 ORFs in the complementary-sense strand. The full-length genome sequence of the isolate (clone VN7) shared the highest level of nucleotide sequence identity (83 %) with the isolate IN:Pusa:Tb:10 of tobacco leaf curl Pusa virus (HQ180391). The phylogenetic relationship of VN7 to other begomoviruses was also investigated. VN7 grouped most closely with a clade containing begomoviruses from China, India and Japan. According to the current taxonomic criteria for the genus Begomovirus, family Geminiviridae, the isolate VN7 represents a new species, herein named “Premna leaf curl virus” (PrLCV). 相似文献