全文获取类型
收费全文 | 777篇 |
免费 | 56篇 |
国内免费 | 7篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 21篇 |
2020年 | 23篇 |
2019年 | 26篇 |
2018年 | 49篇 |
2017年 | 33篇 |
2016年 | 39篇 |
2015年 | 41篇 |
2014年 | 45篇 |
2013年 | 60篇 |
2012年 | 63篇 |
2011年 | 39篇 |
2010年 | 30篇 |
2009年 | 34篇 |
2008年 | 42篇 |
2007年 | 39篇 |
2006年 | 22篇 |
2005年 | 23篇 |
2004年 | 21篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1970年 | 2篇 |
1968年 | 4篇 |
排序方式: 共有840条查询结果,搜索用时 31 毫秒
801.
Yasser AbdElsattar Elghobashy Mohamed FA. Assar Asmaa A. Mahmoud Abdel Monem A Eltorgoman Saher Elmasry 《Biochemistry and Biophysics Reports》2020
Backgroundβ-thalassemia is an inherited hemoglobinopathy resulting in quantitative changes in the β-globin chain. Understanding the molecular basis of that disorder requires studying the expression of genes controlling the pathways that affect the erythropoietic homeostasis especially the MAPK pathway. The MAPKs are a family of serine/threonine kinases that play an essential role in connecting cell-surface receptors to DNA in the nucleus of the cell.Aimto study the effect of expression of GNAI2, DUSP5 and ARRB1 genes on MAPK signaling pathway in pediatric patients with beta thalassemia.MethodsForty children with beta thalassemia major (TM), forty children with beta thalassemia intermedia (TI) and forty age and gender matched healthy controls were enrolled in this study. Detection of GNAI2, DUSP5 and ARRB1 mRNA expression was done by real time polymerase chain reaction (RT-PCR).Resultsrevealed increased expression of ARRB1 (Arrestin Beta 1) gene, and decreased expression of both GNAI2 (Guanine nucleotide-binding protein G (i) subunit alpha-2) and DUSP5 (Dual specificity protein phosphatase 5) genes in both patient groups than control groups respectively.ConclusionsChange in the rate of expression of ARRB1, GNAI2 and DUSP5 may have a role in the pathogenesis of abnormal hematopoiesis in cases of β thalassemia through affecting the MAPK pathway. 相似文献
802.
Rui M. Barros Clara I. Extremina Inês C. Gonalves Beatriz O. Braga Victor M. Balco F. Xavier Malcata 《Enzyme and microbial technology》2003,33(7):908-916
In the present research effort, production of derivatives of cardosin A (a plant protease) encompassing full stabilization of its dimeric structure has been achieved, via covalent, multi-subunit immobilization onto highly activated agarose-glutaraldehyde supports. Boiling such enzyme derivatives in the presence of sodium dodecyl sulfate and β-mercaptoethanol did not lead to leaching of enzyme, thus providing evidence for the effectiveness of the attachment procedure. Furthermore, the cardosin A derivatives prepared under optimal conditions presented ca. half the specific activity of the enzyme in soluble form, and were successfully employed at laboratory-scale trials to perform (selective) hydrolysis of α-lactalbumin (α-La), one of the major proteins in bovine whey. Hydrolysates of α-La were assayed for by the OPA method, as well as by FPLC, SDS–PAGE and HPLC. Thermal inactivation of the immobilized cardosin A was also assessed at 40, 50 and 55 °C; at these temperatures, no thermal denaturation took place during incubation for 48 h. The highest degree of hydrolysis was attained by 5 h reaction, at 55 °C and pH 5.2. SDS–PAGE of α-La hydrolysates displayed bands corresponding to low molecular weight peptides. Our results suggest that cardosin A in immobilized form is a good candidate to bring about proteolysis in the dairy industry, namely in whey processing. 相似文献
803.
804.
Rafael S. Brícola André V. Cordeiro Barbara M. Crisol Renata R. Braga Diego G. de Melo Matheus B. Rocha Rafael C. Gaspar Susana C. B. R. Nakandakari Vagner R. R. Silva Chadi P. Anaruma Carlos K. Katashima Raphael D. S. Canciglieri Vitor R. Munõz Isadora C. B. Pavan Ana P. Pinto Fernando M. Simabuco Adelino S. R. da Silva Leandro P. Moura José R. Pauli Dennys E. Cintra Eduardo R. Ropelle 《Cell biochemistry and function》2023,41(1):128-137
805.
806.
807.
808.
Uppermost-Tortonian temperate carbonates occur at the southern margin of the Sorbas Basin (Almería, SE Spain). These carbonates,
included in the Azagador Member, formed in a gentle, shallow-water ramp. Six facies cycles in ramp deposits comprise alternating
bivalve-shell concentrations and coralline algal beds. The basic cycle reflects the landward advance, as relative sea level
rose, of coralline algal deposits, which were the facies of the outer ramp, over bivalve biostromes, which grew in the shallower
areas of the mid-ramp. Biostromes were mainly built by oysters and locally by Isognomon. In many cases, however, the removal of smaller shells by storms left only thin, discontinuous patches of large bivalves
as residual remains of the oyster biostromes. Some original cycles might be missing due to complete removal of bivalve shells
from the biostromes. The six cycles recognised, therefore, should be considered as the minimum number of original cycles in
the Azagador carbonates. The available age constraints suggest these cycles were forced by orbital precession or some higher-frequency
process. Lithological cycles forced by precession are characteristic of the basinal deposits laterally equivalent to the Azagador
carbonates. 相似文献
809.
810.
Taiza H. Figueiredo Carolina L. Harbert Volodymyr Pidoplichko Camila P. Almeida-Suhett Hongna Pan Katia Rossetti Maria F. M. Braga Ann M. Marini 《Molecular neurobiology》2018,55(1):187-200
Approximately, 1.7 million Americans suffer a TBI annually and TBI is a major cause of death and disability. The majority of the TBI cases are of the mild type and while most patients recover completely from mild TBI (mTBI) about 10% result in persistent symptoms and some result in lifelong disability. Anxiety disorders are the second most common diagnosis post-TBI. Of note, TBI-induced anxiety disorders are difficult to treat and remain a chronic condition suggesting that new therapies are needed. Previous work from our laboratory demonstrated that a mild TBI induced an anxiety-like phenotype, a key feature of the human condition, associated with loss of GABAergic interneurons and hyperexcitability in the basolateral amygdala (BLA) in rodents 7 and 30 days after a controlled cortical impact (CCI) injury. We now confirm that animals display significantly increased anxiety-like behavior 30 days after CCI. The anxiety-like behavior was associated with a significant loss of GABAergic interneurons and significant reductions in the frequency and amplitude of spontaneous and miniature GABAA-receptor-mediated inhibitory postsynaptic currents (IPSCs) in the BLA. Significantly, subchronic treatment with alpha-linolenic acid (ALA) after CCI prevents the development of anxiety-like behavior, the loss of GABAergic interneurons, hyperexcitability in the BLA and reduces the impact injury. Taken together, administration of ALA after CCI is a potent therapy against the neuropathology and pathophysiological effects of mTBI in the BLA. 相似文献