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排序方式: 共有542条查询结果,搜索用时 15 毫秒
41.
Marie‐Lonie Delcourt Serge Turcaud Erica Benedetti Laurent Micouin 《Advanced Synthesis \u0026amp; Catalysis》2016,358(8):1213-1218
Herein we wish to report a new non‐enzymatic kinetic resolution of racemic 4‐formyl[2.2]paracyclophane based on Noyori asymmetric transfer hydrogenations (KR‐ATH). Our approach, which provides an efficient access to enantiopure (Rp)‐ and (Sp)‐4‐formyl[2.2]paracyclophane (>99% ee, 39% and 41% isolated yields, respectively), is operationally simple and can be run on the gram‐scale thus confirming the practical applicability of this method.
42.
Growth of carbon nanotube forests on carbon fibers with an amorphous silicon interface 总被引:1,自引:0,他引:1
Valdirene Gonzaga de Resende Erica Freire Antunes Anderson de Oliveira Lobo Deiler Antônio Lima Oliveira Vladimir Jesus Trava-Airoldi Evaldo José Corat 《Carbon》2010,48(12):3655-1076
Aligned multi-walled carbon nanotube forests were grown by chemical vapour deposition on carbon fibers by the use of an amorphous Si interface. The Si layer creates a barrier, hindering the Fe catalyst diffusion into the carbon fibers. This method provides a way to tailor the thermal, electrical and mechanical properties of the fiber-resin interface of a polymer composite. 相似文献
43.
Sabuj Mallik Erica Hiu Laam Chan Ndy Ekere 《Journal of Materials Engineering and Performance》2013,22(4):1186-1193
Sn-Ag-Cu solder pastes are widely used as the joining material in the electronic assembly process. The aim of this work was to evaluate the nonlinear viscoelastic behaviors of three different Sn-Ag-Cu solder pastes. Three novel rheological test methods were developed for this purpose. These include viscosity, thixotropic loop, and oscillatory amplitude sweep tests. The nonlinear flow curves obtained from the viscosity tests revealed the “shear-thinning” behavior of solder paste samples. Thixotropic loop test results explain the time-dependent structural breakdown and recovery of solder pastes. The viscoelastic properties of solder pastes were interpreted through oscillatory test parameters: storage modulus (G′), loss modulus (G″), and phase angle (δ). The discrepancies observed in the rheological behaviors of the paste samples were found to be related with flux composition (liquid phase in the solder paste) and particle size distribution. 相似文献
44.
Brodbeck WG Colton E Anderson JM 《Journal of materials science. Materials in medicine》2003,14(8):671-675
A previously established human monocyte culture protocol was used to determine the effects of varying adsorbed proteins on monocyte/macrophage adhesion and survival on dimethyl-silane (DM) or RGD modified glass coverslips. Cells were allowed to adhere for 2 h in the absence of protein or in the presence of serum, fibrinogen (Fg), heat inactivated serum (HIS), serum supplemented with Fg or HIS with Fg. Cell adhesion and apoptosis rates were determined on days 0 (2 h), 3, 7 and 10 of culture. The presence of serum alone in the initial culture was sufficient to optimize monocyte/macrophage adhesion and survival rates. Adding Fg to serum did not increase adhesion nor decrease apoptotic rates. No protein or the addition of HIS during the initial incubation period significantly decreased monocyte/macrophage adhesion and survival on both surfaces, however, the addition of Fg to HIS restored adhesion and survival rates to those seen with in the presence of serum alone on RGD surfaces. These studies demonstrate that monocyte/macrophage adhesion and survival on biomaterial surfaces are optimized by adsorbed heat labile serum proteins while adsorbed Fg plays a surface property-dependent role. 相似文献
45.
Cecchini P De Franceschi G Frare E Fontana A Polverino de Laureto P 《Protein engineering, design & selection : PEDS》2012,25(4):199-203
In order to understand the role of tryptophan in the mechanisms of fibrils formation, the ability of a series of analogs of the residue 7-18 span of myoglobin to form amyloid-like fibrils was investigated. Alternatively one or both tryptophans were substituted with alanine and leucine, to determine the contribution of hydrophobicity and aromaticity. The scale of aggregation propensity of the peptides determined indicates that tryptophan is crucial for the amyloidogenic process. Since the rare tryptophan residue is generally engaged in structural roles in proteins, or when exposed serves as binding sites, we surmise that its exposure in the amyloidogenic fragments allows for intermolecular clustering with residues from other molecules leading to the formation of amyloid aggregates. 相似文献
46.
Problems with contracting out government services: lessons from orderly services at SCGH 总被引:1,自引:0,他引:1
This paper identifies and discusses the problems associatedwith contracting out labor-intensive government services. Itexamines in detail the contracting out of the orderly serviceat Sir Charles Gairdner Hospital (SCGH) in Western Australiaand its subsequent return to in-house delivery. When the orderlyservice was contracted out, the result was poor in terms ofcost, quality and externalities. Subsequent return of the serviceto in-house provision reduced costs and improved quality. Theproblems that led to failure of contracting out and subsequentsuccess of in-house provision can be explained in terms of transactioncost economics. 相似文献
47.
48.
Lipid ingredients that demonstrate high stability and positive health profiles without the use of trans‐fats are needed in the food supply. Rice bran oil can be fractionated at low temperatures to create a series of spreads that show promise as functional ingredients. A rice bran oil‐derived spread can extend the fry life of soybean oil and can also be incorporated into baked goods such as bread and granola as a trans‐fat free alternative to butter or shortening. 相似文献
49.
50.
Alessia Vignoli Emanuela Risi Amelia McCartney Ilenia Migliaccio Erica Moretti Luca Malorni Claudio Luchinat Laura Biganzoli Leonardo Tenori 《International journal of molecular sciences》2021,22(9)
Precision oncology is an emerging approach in cancer care. It aims at selecting the optimal therapy for the right patient by considering each patient’s unique disease and individual health status. In the last years, it has become evident that breast cancer is an extremely heterogeneous disease, and therefore, patients need to be appropriately stratified to maximize survival and quality of life. Gene-expression tools have already positively assisted clinical decision making by estimating the risk of recurrence and the potential benefit from adjuvant chemotherapy. However, these approaches need refinement to further reduce the proportion of patients potentially exposed to unnecessary chemotherapy. Nuclear magnetic resonance (NMR) metabolomics has demonstrated to be an optimal approach for cancer research and has provided significant results in BC, in particular for prognostic and stratification purposes. In this review, we give an update on the status of NMR-based metabolomic studies for the biochemical characterization and stratification of breast cancer patients using different biospecimens (breast tissue, blood serum/plasma, and urine). 相似文献