全文获取类型
收费全文 | 139篇 |
免费 | 13篇 |
国内免费 | 5篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 75 毫秒
71.
Annalisa Relini Ornella Cavalleri Ranieri Rolandi Alessandra Gliozzi 《Chemistry and physics of lipids》2009,158(1):1-4807
Investigating the pathways leading to the formation of amyloid protein aggregates and the mechanism of their cytotoxicity is fundamental for a deeper understanding of a broad range of human diseases. Increasing evidence indicates that early aggregates are responsible for the cytotoxic effects. This paper addresses the catalytic role of lipid surfaces in promoting aggregation of amyloid proteins and the permeability changes that these aggregates induce on lipid membranes. Effects of amyloid aggregates on model systems such as monolayers, vesicles, liposomes and supported lipid bilayers are reviewed. In particular, the relevance of atomic force microscopy in detecting both kinetics of amyloid formation and amyloid-membrane interactions is emphasized. 相似文献
72.
Gabriela Huelgas Ratnasamy Somanathan Julio M. Hernndez Prez Haydee Rojas Cabrera Maximiliano de la Higuera Macías Alejandra Domínguez‐Huerta Rocío Sabala Cecilia Anaya de Parrodi 《Chirality》2021,33(1):22-36
In this study, the novel bifunctional homochiral thiourea‐L‐prolinamides 1–4 , tertiary amino‐L‐prolinamide 5 , and bis‐L‐prolinamides 6 and 7 were prepared from enantiomerically pure (11R,12R)‐11,12‐diamino‐9,10‐dihydro‐9,10‐ethanoanthracene 8 and (11S,12S)‐11,12‐diamino‐9,10‐dihydro‐9,10‐ethanoanthracene ent‐8 . Highly enantioselective and diastereoselective aldolic intermolecular reactions (up to 95% enantiomeric excess, 93:7 anti/syn) between aliphatic ketones (20 equiv) and a range of aromatic aldehydes (1 equiv) were successfully carried out in the presence of water (10 equiv) and monochloroacetic acid (10 mol%), solvent‐free conditions, at room temperature over 24 h using organocatalysts 1–7 (5 mol%). Stereoselective induction using density functional theory–based methods was consistent with the experimental data. 相似文献
73.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used drugs in the world due to their anti-inflammatory, analgesic and antipyretic properties. Nevertheless, the consumption of these drugs is still associated with the occurrence of a wide spectrum of adverse effects. Regarding the major role of membranes in cellular events, the hypothesis that the biological actions of NSAIDs may be related to their effect at the membrane level has triggered the in vitro assessment of NSAIDs-membrane interactions. The use of membrane mimetic models, cell cultures, a wide range of experimental techniques and molecular dynamics simulations has been providing significant information about drugs partition and location within membranes and also about their effect on diverse membrane properties. These studies have indeed been providing evidences that the effect of NSAIDs at membrane level may be an additional mechanism of action and toxicity of NSAIDs. In fact, the pharmacokinetic properties of NSAIDs are closely related to the ability of these drugs to interact and overcome biological membranes. Moreover, the therapeutic actions of NSAIDs may also result from the indirect inhibition of cyclooxygenase due to the disturbing effect of NSAIDs on membrane properties. Furthermore, increasing evidences suggest that the disordering effects of these drugs on membranes may be in the basis of the NSAIDs-induced toxicity in diverse organ systems. Overall, the study of NSAIDs-membrane interactions has proved to be not only important for the better understanding of their pharmacological actions, but also for the rational development of new approaches to overcome NSAIDs adverse effects. 相似文献
74.
A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine-derived organocatalyst containing silicon-based bulky group, QN-TBS, -catalyzed aza-Michael reaction under solvent-free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro-aza-Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro-aza-Michael reaction and aza-Michael reaction produce the happening of chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza-Michael reactions. 相似文献
75.
Mike Slade Michaela Amering Marianne Farkas Bridget Hamilton Mary O'Hagan Graham Panther Rachel Perkins Geoff Shepherd Samson Tse Rob Whitley 《World psychiatry》2014,13(1):12-20
An understanding of recovery as a personal and subjective experience has emerged within mental health systems. This meaning of recovery now underpins mental health policy in many countries. Developing a focus on this type of recovery will involve transformation within mental health systems. Human systems do not easily transform. In this paper, we identify seven mis‐uses (“abuses”) of the concept of recovery: recovery is the latest model; recovery does not apply to “my” patients; services can make people recover through effective treatment; compulsory detention and treatment aid recovery; a recovery orientation means closing services; recovery is about making people independent and normal; and contributing to society happens only after the person is recovered. We then identify ten empirically‐validated interventions which support recovery, by targeting key recovery processes of connectedness, hope, identity, meaning and empowerment (the CHIME framework). The ten interventions are peer support workers, advance directives, wellness recovery action planning, illness management and recovery, REFOCUS, strengths model, recovery colleges or recovery education programs, individual placement and support, supported housing, and mental health trialogues. Finally, three scientific challenges are identified: broadening cultural understandings of recovery, implementing organizational transformation, and promoting citizenship. 相似文献
76.
Integrin receptors play important roles in cell adhesion and tumor metastasis. The coupling of mechanical sensing and biochemical ligation is known to collectively regulate the activation of integrin receptors. Recently, oligomerization of activated integrins has been considered as the primordial signature of cytoskeletal remodeling and the initiation of various downstream signals, such as focal and fibrillar adhesions. However, spatio-temporal reorganization of activated integrins and associated proteins remains poorly understood. Here, we summarized the recent discovery of sequential biophysical events of integrin activation during early adhesion formation. Using the cyclic Arg-Gly-Asp (RGD) peptide as a mobile ligand on supported lipid membranes, a series of previously unreported events were observed following integrin αvβ3 clustering and cell spreading, including a long-range lateral translocation of the integrin clusters. With initial clustering, localized actin polymerization occurred in a Src family kinase dependent manner. Clustering of liganded integrins recruits various adaptor proteins and serves as a reaction core for mechanobiological activities. In addition, there are future possibilities to investigate the role of other synergetic interactions with the activated integrin receptors. 相似文献
77.
Perstractive fermentation is a good way to increase the productivity of bioreactors. UsingPropionibacteria as the model system, the feasibility of using supported emulsion liquid membrane (SELM) for perstractive fermentation is
assessed in this study. Five industrial solvents were considered as the solvent for preparing the SELM. The more polar a solvent
is, the higher the partition coefficient. However, toxicity of a solvent also increases with its polarity. CO-1055 (industrial
decanol/octanol blend) has the highest partition coefficient toward propionic acid among the solvents that has no molecular
toxicity towardPropionibacteria. A preliminary extraction study was conducted using tetradecane as solvent in a hydrophobic hollow fiber contactor. The result
confirmed that SELM eliminates the equilibrium limitation of conventional liquid-liquid extraction, and allows the use of
a non-toxic solvent with low partition coefficient. 相似文献
78.
The molecular order of fatty acyl chains in oriented lipid bilayers on solid support (SPB), made of either natural or synthetic phospholipids oxidized by Fenton reagent and probed with spin labeled lecithin (5-DSPC) was studied by means of EPR spectrometry. Phospholipids (ASPC, EYPC, mitochondrial extract) were oxidized as either aqueous buffer/methanol dispersions or reverse-phase evaporation vesicles (REV) suspensions. Oxidation was preliminarily revealed both by assaying MDA and by detecting conjugated dienes. Oxidized phospholipid species was quantified by preparative TLC. The degree of order in oriented lipid bilayers of samples containing oxidized phospholipids was estimated by the loss of EPR spectral anisotropy, and an empirical index of the related bilayer disorder was calculated from the second derivative spectra. Bilayers made of each non-oxidized phospholipid species from either ethanol solutions or REV suspensions showed the highest anisotropy, while the increasing presence of oxidized lipids in the samples resulted in progressive loss of EPR spectral anisotropy. In contrast, vesicles containing 40% of the oxidized species maintained an unaltered fluidity gradient, while REV formation was hindered by oxidized phospholipid percentages higher than 45% for ASPC and EYPC, and 35% for Mitochondrial lipids (MtL). It is concluded that the early stages of lipoperoxidation bring about disordering of the phospholipid bilayer interior rather than fluidity alterations, and that prolonged oxidation may result in loss of structural and chemical properties of the bilayer until the structure no longer holds. 相似文献
79.
大豆黄酮对大鼠乳腺发育作用的实验研究 总被引:17,自引:1,他引:17
本文研究了大豆黄酮对大鼠乳腺发育及其对垂体生长激素(GH)和催乳素(PRL)分泌的影响,结果表明:1)胃饲或皮下注射大豆黄酮能显著提高去卵巢大鼠或正常处女大鼠乳腺重量和乳腺DNA、RNA含量;2)胃饲或皮下注射大豆黄酮能显著提高正常处女大鼠血清GH和PRL含量,3)大豆黄酮能显著提高大鼠乳腺,垂体和下丘脑胞浆雌二醇受体的数目,并显著提高乳腺孕酮受体的数目,体外受体竞争结合试验结果表明:大豆黄酮与大 相似文献
80.
大豆黄酮促进妊娠大鼠乳腺发育和泌乳的实验研究 总被引:13,自引:0,他引:13
研究大豆黄酮(Da)对妊娠大鼠乳腺发育和泌乳的作用及其与神经内分泌的关系,结果表明;妊娠期口服大豆黄酮,能显著提高泌乳前期大鼠乳腺重量、DNA、RNA含量和RNA/DNA值,同时极显著地提高大鼠的泌乳量、血清GH和PRL含量及乳腺胞浆雌二醇受体的数目和亲和力;相反.妊娠后期口服多巴胺激动剂溴隐亭,能显著降低泌乳前期乳腺重量、DNA和RNA含量及泌乳量,并显著降低血清GH和PRL含量及乳腺雌二醇受体的数目和亲和力;但连续两周口服Da后再口服澳隐亭一周,溴隐亭的上述作用被阻断。结果提示:Da促进大鼠乳腺发育和泌乳的作用与其抑制或站抗多巴胺对垂体PRL、GH分泌的抑制作用有关。 相似文献