全文获取类型
收费全文 | 2630篇 |
免费 | 218篇 |
国内免费 | 1篇 |
出版年
2022年 | 20篇 |
2021年 | 54篇 |
2020年 | 27篇 |
2019年 | 39篇 |
2018年 | 53篇 |
2017年 | 44篇 |
2016年 | 77篇 |
2015年 | 89篇 |
2014年 | 115篇 |
2013年 | 150篇 |
2012年 | 184篇 |
2011年 | 160篇 |
2010年 | 98篇 |
2009年 | 99篇 |
2008年 | 121篇 |
2007年 | 108篇 |
2006年 | 96篇 |
2005年 | 87篇 |
2004年 | 95篇 |
2003年 | 65篇 |
2002年 | 72篇 |
2001年 | 64篇 |
2000年 | 58篇 |
1999年 | 47篇 |
1998年 | 18篇 |
1997年 | 29篇 |
1996年 | 20篇 |
1993年 | 18篇 |
1992年 | 54篇 |
1991年 | 27篇 |
1990年 | 30篇 |
1989年 | 29篇 |
1988年 | 40篇 |
1987年 | 31篇 |
1986年 | 28篇 |
1985年 | 48篇 |
1984年 | 27篇 |
1983年 | 34篇 |
1982年 | 19篇 |
1981年 | 30篇 |
1980年 | 20篇 |
1979年 | 30篇 |
1978年 | 30篇 |
1977年 | 21篇 |
1976年 | 19篇 |
1975年 | 29篇 |
1974年 | 16篇 |
1973年 | 23篇 |
1972年 | 22篇 |
1971年 | 19篇 |
排序方式: 共有2849条查询结果,搜索用时 15 毫秒
961.
962.
Jamila H. Siamwala Paul M. Dias Syamantak Majumder Manoj K. Joshi Vilas P. Sinkar Gautam Banerjee Suvro Chatterjee 《The Journal of nutritional biochemistry》2013,24(3):595-605
Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca2 + and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea. 相似文献
963.
Ashutosh Banerjee Simone Maschauer Harald Hübner Peter Gmeiner Olaf Prante 《Bioorganic & medicinal chemistry letters》2013,23(22):6079-6082
Taking advantage of click chemistry, a library of N-arylpiperazinylmethyl triazoles bearing fluoro substituted appendages was synthesized and the target compounds were investigated for dopamine and serotonin receptor binding. With the aim to bias their hydrophilicity and to optimize their D4 receptor affinity and selectivity, a concise series of triazoles containing fluoroalkyl, fluoroalkoxy, fluoroalkoxyphenyl, and deoxyfluoroglucosyl substituents was studied. The D4 receptor affinity and selectivity could be tuned by altering the chemical moiety attached to the triazole unit. Among the test compounds, the fluoroethoxyphenyl derivative 15b showed weak partial agonism at D4 and a Ki value of 14 nM, while its fluoropropoxyphenyl homologue 16a turned out to act as a neutral D4 antagonist (Ki = 5.1 nM). Both, 15b and 16a revealed an excellent balance between D4 receptor affinity and subtype selectivity, providing lead candidates for the development of 18F-labeled radioligands for D4 receptor imaging studies by positron emission tomography (PET). 相似文献
964.
Mujahid Yusufi Sanjeev Banerjee Momin Mohammad Sandhya Khatal K. Venkateswara Swamy Ejazuddin M. Khan Amro Aboukameel Fazlul H. Sarkar Subhash Padhye 《Bioorganic & medicinal chemistry letters》2013,23(10):3101-3104
Thymoquinone (TQ), isolated from the seeds of Nigella sativa, show moderate efficacy against pancreatic cancer. In the present work we report synthesis and characterization of novel TQ analogs appended with gallate and fluorogallate pharmacophores and evaluation of their effects against pancreatic cancer cell lines for cell viability and induction of apoptosis. The efficacy of the analogs alone or in combination with Gemcitabine was assessed in vitro. LC–MS spectra of ATQTHB and ATQTFB showed major peaks corresponding to expected M+1 fragment at 316.34 and 322.34 respectively. Molecular docking studies revealed good fit for these analogs in the COX-2 protein cavity with better binding energies compared to parent TQ compound. Present TQ analogs exhibit superior anti-proliferative activity, excellent chemo-sensitizing activity against pancreatic cancer in vitro and in combination with Gemcitabine. 相似文献
965.
Matthew A. Windsor Pieter L. Valk Shu Xu Surajit Banerjee Lawrence J. Marnett 《Bioorganic & medicinal chemistry letters》2013,23(21):5860-5864
Lumiracoxib is a substrate-selective inhibitor of endocannabinoid oxygenation by cyclooxygenase-2 (COX-2). We assayed a series of lumiracoxib derivatives to identify the structural determinants of substrate-selective inhibition. The hydrogen-bonding potential of the substituents at the ortho positions of the aniline ring dictated the potency and substrate selectivity of the inhibitors. The presence of a 5′-methyl group on the phenylacetic acid ring increased the potency of molecules with a single ortho substituent. Des-fluorolumiracoxib (2) was the most potent and selective inhibitor of endocannabinoid oxygenation. The positioning of critical substituents in the binding site was identified from a 2.35 Å crystal structure of lumiracoxib bound to COX-2. 相似文献
966.
Koulagi Ramanna Banerjee Sagar Gawade Bharat H. Singh Ashish Kumar Jain P. K. Praveen Shelly Subramaniam K. Sirohi Anil 《Plant Cell, Tissue and Organ Culture》2020,143(2):345-361
Plant Cell, Tissue and Organ Culture (PCTOC) - Tomato is a key vegetable crop cultivated in nearly all agricultural regions of the world. It is a protective food very rich in vitamin A and C.... 相似文献
967.
Sana Ghayas M. Ali Masood Rashida Parveen Md Aquib Muhammad Asim Farooq Parikshit Banerjee 《Journal of biomolecular structure & dynamics》2020,38(10):2916-2927
AbstractTyrosinase plays an important role in melanin biosynthesis and protects skin against ultraviolet radiations. Functional deficiency of tyrosinase results in serious dermatological diseases. Tyrosinase also participates in neuromelanin formation in the human brain, which leads to neurodegeneration resulting in Parkinson’s disease. In fruits and vegetables, tyrosinase plays a critical role in senescence, causing undesired browning that results in faster deterioration and shorter shelf lines. The only commercially available tyrosinase is mushroom tyrosinase and it shows the highest homology to the mammalian tyrosinase. Although kojic acid is currently used as a tyrosinase inhibitor, they have serious side effects such as dermatitis, carcinogenesis and hepatotoxicity. Therefore, in order to develop a more active and safer tyrosinase inhibitor, 3D QSAR pharmacophore models were generated based on experimentally known inhibitors. The pharmacophore model, Hypo1, was developed with a large cost difference, high correlation coefficient and low RMS deviation. Hypo1 showed a good spatial arrangement; consisting of five-point features including two hydrogen bond acceptor, one hydrogen bond donor and two hydrophobic features. Hypo1 was further validated by cost analysis, test set and Fisher’s randomisation method. Hypo1 was used as a 3D query for screening the in-house drug-like databases, and the hits were further selected by applying ADMET, Lipinski’s rule of five and fit value criteria. To identify binding conformations, the obtained hits were subjected to molecular docking. Finally, molecular dynamics simulations revealed the appropriate binding modes of hit compounds. To conclude, we propose the final three hit compounds with new structural scaffolds as a virtual candidate as tyrosinase inhibitors.Communicated by Ramaswamy H. Sarma 相似文献
968.
Journal of Plant Growth Regulation - Excessive utilization of groundwater for anthropogenic purposes has led to severe depletion of the water table, resulting in contamination of fluorides from the... 相似文献
969.
Banerjee M Pramanik M Bhattacharya D Lahiry M Chakrabarti A 《Journal of biosciences》2011,36(5):809-816
We report studies on loss of heme at or below pH 3.0 from two clinically important hemoglobin variants, HbE and HbS, in the
presence and absence of phopholipid membranes. The kinetics of heme loss has been studied at pH 3.0 to simulate the same at
a faster rate than at physiological pH, for spectroscopic investigation. Results obtained from the study clearly establish
the probable fate of the lost heme to partition into the phospholipid bilayer independent of the pH range. This is also of
particular importance to membranes containing the aminophospholipid and cholesterol which are predominantly localized in the
inner leaflet of erythrocytes. Absorption measurements indicated such loss of heme when the Soret peak at 415 nm blue-shifted
to 380 nm at pH 3.0. The extent of this blue shift decreased from 35 nm to ~15 nm in the presence of small unilammelar vesicles
of both dimyristoyl- and dioleoyl-based phosphatidylcholine and phosphatidylethanolamine, indicating partitioning of the released
heme in the membrane bilayer. The kinetics of heme loss was faster from HbE than HbA and HbS, obeying first-order reaction
kinetics. Released heme could be involved in the premature destruction of erythrocytes in hemoglobin disorders. 相似文献
970.
Zhiwei Wang Yiwei Li Aamir Ahmad Sanjeev Banerjee Asfar S. Azmi Dejuan Kong Christine Wojewoda Lucio Miele Fazlul H. Sarkar 《Journal of cellular biochemistry》2011,112(1):78-88
Although many studies have been done to uncover the mechanisms by which down‐regulation of Notch‐1 exerts its anti‐tumor activity against a variety of human malignancies, the precise molecular mechanisms remain unclear. In the present study, we investigated the cellular consequence of Notch‐1 down‐regulation and also assessed the molecular consequence of Notch‐1‐mediated alterations of its downstream targets on cell viability and apoptosis in prostate cancer (PCa) cells. We found that the down‐regulation of Notch‐1 led to the inhibition of cell growth and induction of apoptosis, which was mechanistically linked with down‐regulation of Akt and FoxM1, suggesting for the first time that Akt and FoxM1 are downstream targets of Notch‐1 signaling. Moreover, we found that a “natural agent” (genistein) originally discovered from soybean could cause significant reduction in cell viability and induced apoptosis of PCa cells, which was consistent with down‐regulation of Notch‐1, Akt, and FoxM1. These results suggest that down‐regulation of Notch‐1 by novel agents could become a newer approach for the prevention of tumor progression and/or treatment, which is likely to be mediated via inactivation of Akt and FoxM1 signaling pathways in PCa. J. Cell. Biochem. 112: 78–88, 2011. © 2010 Wiley‐Liss, Inc. 相似文献