全文获取类型
收费全文 | 873篇 |
免费 | 162篇 |
国内免费 | 5篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 20篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 12篇 |
2016年 | 27篇 |
2015年 | 51篇 |
2014年 | 27篇 |
2013年 | 50篇 |
2012年 | 70篇 |
2011年 | 62篇 |
2010年 | 38篇 |
2009年 | 39篇 |
2008年 | 44篇 |
2007年 | 43篇 |
2006年 | 48篇 |
2005年 | 41篇 |
2004年 | 33篇 |
2003年 | 34篇 |
2002年 | 30篇 |
2001年 | 25篇 |
2000年 | 29篇 |
1999年 | 16篇 |
1998年 | 11篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 24篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 20篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有1040条查询结果,搜索用时 12 毫秒
161.
Law Peter K. Haider Kh. Fang G. Jiang S. Chua F. Lim Y.T. Sim E. 《Molecular and cellular biochemistry》2004,263(1):173-178
Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia. His ejection fraction increased by 13%. He no longer experienced shortness of breath and angina as he did before the treatment. Three myogenesis mechanisms were elucidated with 17 human/porcine xenografts using cyclosporine as immunosuppressant. Some myoblasts developed to become cardiomyocytes. Others transferred their nuclei into host cardiomyocytes through natural cell fusion. As yet others formed skeletal myofibers with satellite cells. De novo production of contractile filaments augmented the heart contractility. Human myoblasts transduced with VEGF165 gene produced six times more capillaries in porcine myocardium than in placebo. Xenograft rejection was not observed for up to 20 weeks despite cyclosporine discontinuation at 6 weeks. Pros and cons of autografts vs. allografts are compared to guide future development of heart cell therapy. (Mol Cell Biochem 263: 173–178, 2004) 相似文献
162.
Bhunia A Chua GL Domadia PN Warshakoon H Cromer JR David SA Bhattacharjya S 《Biochemical and biophysical research communications》2008,369(3):853-857
Designed peptides that would selectively interact with lipopolysaccharide (LPS) or endotoxin and fold into specific conformations could serve as important scaffolds toward the development of antisepsis compounds. Here, we describe solution structure of a designed amphipathic peptide, H2N-YVKLWRMIKFIR-CONH2 (YW12D) in complex with endotoxin as determined by transferred nuclear Overhauser effect spectroscopy. The conformation of the isolated peptide is highly flexible, but undergoes a dramatic structural stabilization in the presence of LPS. Structure calculations reveal that the peptide presents two amphipathic surfaces in its bound state to LPS whereby each surface is characterized by two positive charges and a number of aromatic and/or aliphatic residues. ITC data suggests that peptide interacts with two molecules of lipid A. In activity assays, YW12D exhibits neutralization of LPS toxicity with very little hemolysis of red blood cells. Structural and functional properties of YW12D would be applicable in designing low molecular weight non-toxic antisepsis molecules. 相似文献
163.
The gene of Blomia tropicalis group 5 allergen (Blo t 5) was cloned and expressed in Pichia pastoris KM71. Selected KM71 clones were cultivated in a fed-batch bioreactor feeding first glycerol then followed by methanol. Recombinant Blo t 5 constituted about 30% of the total broth protein after 60 h cultivation. The harvested broth was purified to >95% purity by a two-step anion exchange chromatography. The overall yield was 37 mg Blo t 5 per litre broth. 相似文献
164.
Whereas retinoic acids control nuclear events, a second class of retinol metabolites, that is, the hydroxylated forms exemplified by 14-hydroxy-retro-retinol (HRR), operate primarily in the cytoplasm. They function as regulatory cofactors for cell survival/cell death decisions. In accordance with these biological aspects, we demonstrate that these retinoids bound protein kinase C (PKC) alpha with nanomolar affinity and markedly enhance the activation of PKC alpha and the entire downstream MAP kinase pathway by reactive oxygen species. HRR was 10 times more efficient than retinol, and the optimum doses are 10-7 and 10-6 M, respectively. PKC alpha activation was reversed rapidly by imposition of reducing conditions. The retinoid binding site was mapped to the first cysteine-rich region in the regulatory domain, C1A, yet was distinct from the binding sites of diacylglycerol and phorbol esters. The C1B domain bound retinoids poorly. The emerging theme is that retinoids serve as redox regulators of protein kinase C. 相似文献
165.
166.
Cellular stressors typically induce two protective counter‐responses—autophagy and the unfolded protein response (UPR). It is conceivable that these two endoplasmic reticulum (ER) membrane‐based processes would intersect/interact somehow with the constitutive housekeeping process of exocytic membrane traffic from the ER. How exactly might this occur? Recent evidence indicates that a conserved Rab protein, Rab1/Ypt1p, has functional roles in UPR and autophagy. This molecular switch and its associated effectors may therefore serve to link up a network of cellular responses to stress through changes in membrane dynamics and protein turnover. The notion provides further explanations as to why elevation of Rab1/Ypt1p levels could counter the cytotoxicity of α‐synuclein, and a similar mode of protection may well be at work against other stresses. J. Cell. Physiol. 228: 1638–1640, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
167.
The relationship between the infestation rate of carambola fruits byBactrocera carambolae Drew and Hancock was investigated in a carambola orchard. Phenology of the fruits was found to influence percentage infestation of fruits byB. carambolae. The proportion of unbagged or susceptible fruits infested varied with time of year and tended to decrease with the increase of unbagged fruits available on the tree. The number of ovipunctures per fruit varied with fruit size and was also found to be indicative of the number of adult insects (B. carambolae and parasitoids) that will emerge from each fruit. Higher number of susceptible fruits available on each tree also decreased both the number of ovipunctures per fruit and the number of eggs laid per fruit, which could possibly be due to the strategy of spreading the risk adopted by the femaleB. carambolae or a result of random selection with more hosts available. The main parasitoids recorded wereBiosteres vandenboschi (Fullaway) andB. arisanus (Sonan). The mean percentage of parasitism was 38.3% and it followed roughly that of infestation of fruits. 相似文献
168.
α-synuclein gene mutations are major underlying genetic defects known in familial juvenile onset Parkinson's disease (PD), and α-synuclein is a major constituent of Lewy Bodies, the pathological hallmark of PD. The normal cellular function of α-synuclein has been elusive, and its exact etiological mechanism in causing dopaminergic neuronal death in PD is also not clearly understood. Very recent reports now indicate that mutant or simply over-expressed α-synuclein could cause damage by interfering with particular steps of neuronal membrane traffic. α-synuclein selectively blocks endoplamic reticulum-to-Golgi transport, thus causing ER stress. A screen in a yeast revealed that α-synuclein toxicity could be suppressed by over-expression of the small GTPase Ypt1/Rab1, and that over-expression of the latter rescues neuron loss in invertebrate and mammalian models of α-synuclein-induced neurodegeneration. α-synuclein may also serve a chaperone function for the proper folding of synaptic SNAREs that are important for neurotransmitter release. We discuss these recent results and the emerging pathophysiological interaction of α-synuclein with components of neuronal membrane traffic. 相似文献
169.
Joey Chua 《Arts Education Policy Review》2018,119(1):53-71
This article provides an overview of dance education in schools in Singapore with regard to physical education, co-curricular activity, initiatives by the National Arts Council's Arts Education unit, and pre-tertiary and tertiary dance programs. In an effort to gain a better understanding of how well the official discourse and the reality of schooling in dance interconnect, a meta-analysis of published articles, conference papers, committee reports, and curricula was conducted. Situated within the larger sociocultural, political, and historical contexts, Singapore presents a curious case for probing the merits and limitations of research, policy initiatives, and policy implementation. In the conclusion, the author argues that the development of a coherent dance education in Singapore requires “fixing” three dilemmas—meritocratic schooling in dance, the ill-defined and exhaustive use of the term “talent,” and the uneven research that has not kept pace with the policy initiatives. 相似文献
170.