全文获取类型
收费全文 | 1216篇 |
免费 | 49篇 |
国内免费 | 3篇 |
出版年
2023年 | 7篇 |
2022年 | 13篇 |
2021年 | 26篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 34篇 |
2017年 | 27篇 |
2016年 | 44篇 |
2015年 | 60篇 |
2014年 | 80篇 |
2013年 | 96篇 |
2012年 | 101篇 |
2011年 | 89篇 |
2010年 | 69篇 |
2009年 | 56篇 |
2008年 | 64篇 |
2007年 | 57篇 |
2006年 | 43篇 |
2005年 | 34篇 |
2004年 | 39篇 |
2003年 | 25篇 |
2002年 | 20篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 20篇 |
1998年 | 17篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 22篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1972年 | 4篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有1268条查询结果,搜索用时 15 毫秒
41.
Kumar Ritesh Khungar Lisha Shimphrui Rinchuila Tiwari Lalit Dev Tripathi Gayatri Sarkar Neelam K. Agarwal Surekha-Katiyar Agarwal Manu Grover Anil 《Journal of plant biochemistry and biotechnology.》2020,29(4):715-732
Journal of Plant Biochemistry and Biotechnology - Caseinolytic protease (Clp)/Hsp100 proteins are members of the AAA+ (ATPase associated with a variety of cellular activities) family of proteins... 相似文献
42.
D. Tripathi 《Computer methods in biomechanics and biomedical engineering》2013,16(15):1648-1657
This paper studies the peristaltic transport of a viscoelastic fluid (with the fractional second-grade model) through an inclined cylindrical tube. The wall of the tube is modelled as a sinusoidal wave. The flow analysis is presented under the assumptions of long wave length and low Reynolds number. Caputo's definition of fractional derivative is used to formulate the fractional differentiation. Analytical solutions are developed for the normalized momentum equations. Expressions are also derived for the pressure, frictional force, and the relationship between the flow rate and pressure gradient. Mathematica numerical computations are then performed. The results are plotted and analysed for different values of fractional parameter, material constant, inclination angle, Reynolds number, Froude number and peristaltic wave amplitude. It is found that fractional parameter and Froude number resist the flow pattern while material constant, Reynolds number, inclination of angle and amplitude aid the peristaltic flow. Furthermore, frictional force and pressure demonstrate the opposite behaviour under the influence of the relevant parameters emerging in the equations of motion. The study has applications in uretral biophysics, and also potential use in peristaltic pumping of petroleum viscoelastic bio-surfactants in chemical engineering and astronautical applications involving conveyance of non-Newtonian fluids (e.g. lubricants) against gravity and in conduits with deformable walls. 相似文献
43.
Nisha Saxena Nimisha Singh Mridul Mishra G. B. Shiva Keshava Praveen Kumar Shukla Rama Pati Tripathi 《Journal of enzyme inhibition and medicinal chemistry》2013,28(4):476-482
A series of azatricyclodiones and octahydro-benzo[f]isoindoles have been synthesized by (4+2) Diels-Alder cycloaddition of maleimides with furfuryl amine. Reaction of azatricyclodiones with isocyanates led to the respective ureides. All of the compounds were screened against a number of bacteria and fungi. One of the compounds (2) displayed moderate antitubercular activity while two compounds (2) and (4) inhibited the fungal growth at 25 μg/mL. 相似文献
44.
Synthesis and biological evaluation of potential modulators of malarial glutathione-S-transferase(s)
Rumana Ahmad Arvind K. Srivastava Rama Pati Tripathi Sanjay Batra Rolf D. Walter 《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):327-342
Glutathione-S-transferase(s) (E.C.2.5.1.18, GSTs) have been investigated in parasitic protozoans with respect to their biochemistry and they have been identified as potential vaccine candidates in protozoan parasites and as a target in the synthesis of new antiparasitic agents. In a search towards the identification of novel biochemical targets for antimalarial drug design, the area of Plasmodium glutathione metabolism provides a number of promising chemotherapeutic targets. GST activity was determined in various subcellular fractions of malarial parasites Plasmodium yoelii and was found to be localized mainly in the cytosolic fraction (specific activity, c. 0.058 ± 0.016 μmol/min/mg protein). Hemin, a known inhibitor of mammalian GST(s), maximally inhibited this enzyme from P. yoelii to nearly 86%. In a search towards synthetic modulators of malarial GST(s), 575 compounds belonging to various chemical classes were screened for their effect on crude GST from P. yoelii and 92 compounds belonging to various chemical classes were studied on recombinant GST from P. falciparum. Among all the compounds screened, 83 compounds inhibited/stimulated the enzyme from P. yoelii/P. falciparum to the extent of 40% or more. 相似文献
45.
Rajendra KPandey Snehlata Tripathi Krishna Misra 《Nucleosides, nucleotides & nucleic acids》2013,32(9-11):1937-1948
Abstract Two complementary oligodeoxynucleotide hexamers CATGAA and TTCATG and a pentamer with a fluorescent nucleoside analog viz. 9-N-(2′-deoxy-β-D-ribofuranosyl) carbazole (C*) incorporated into it, TTC*ATG were synthesized and characterised by spectroscopic and chromatographic studies. The comparative fluorescent studies of the two nucleoside analogs viz. 9-N-(2′-deoxy-β-D-ribofuranosyl) acridone and its carbazole analog (C*) have been carried out under different experimental conditions. The effect on fluorescence by incorporation of (C*) into the sequence and its subsequent hybridization with the complementary sequence have been studied. 相似文献
46.
Localized surface plasmon resonance incurred by silver nanoparticles is used to enhance the photoelectric conversion efficiency of a TiO2 nanorod-based dye-sensitized solar cell (DSSC). Improved light transmission is observed experimentally in silver nanoparticle-coated FTO glass. The transmission data are used to explore the effect on electrical parameters of DSSC using theoretical model. Current density increased from 11.7 to 12.34 mA/cm2 and open-circuit voltage increased from 704 to 709.5 mV. Overall efficiency enhancement of 6.67 % is observed in TiO2 nanorod-based DSSC due to plasmon-induced light trapping. 相似文献
47.
Vijayalakshmi Sridharan Preeti Tripathi Sunil Sharma Peter M. Corry Eduardo G. Moros Awantika Singh Cesar M. Compadre Martin Hauer-Jensen Marjan Boerma 《PloS one》2013,8(7)
Radiation-induced heart disease (RIHD) is a long-term side effect of radiotherapy of intrathoracic, chest wall and breast tumors when radiation fields encompass all or part of the heart. Previous studies have shown that pentoxifylline (PTX) in combination with α-tocopherol reduced manifestations of RIHD in rat models of local heart irradiation. The relative contribution of PTX and α-tocopherol to these beneficial effects are not known. This study examined the effects of PTX alone or in combination with tocotrienols, forms of vitamin E with potential potent radiation mitigation properties. Rats received localized X-irradiation of the heart with an image-guided irradiation technique. At 3 months after irradiation rats received oral treatment with vehicle, PTX, or PTX in combination with a tocotrienol-enriched formulation. At 6 months after irradiation, PTX-treated rats showed arrhythmia in 5 out of 14 animals. PTX alone or in combination with tocotrienols did not alter cardiac radiation fibrosis, left ventricular protein expression of the endothelial markers von Willebrand factor and neuregulin-1, or phosphorylation of the signal mediators Akt, Erk1/2, or PKCα. On the other hand, tocotrienols reduced cardiac numbers of mast cells and macrophages, but enhanced the expression of tissue factor. While this new rat model of localized heart irradiation does not support the use of PTX alone, the effects of tocotrienols on chronic manifestations of RIHD deserve further investigation. 相似文献
48.
Ved Prakash Kanchan Vishwakarma Vijay Pratap Singh Padmaja Rai Naleeni Ramawat Durgesh Kumar Tripathi Shivesh Sharma 《Physiologia plantarum》2020,168(2):473-489
Over the past decades the role of nitric oxide (NO) and reactive oxygen species (ROS) in signaling and cellular responses to stress has witnessed an exponential trend line. Despite advances in the subject, our knowledge of the role of NO and ROS as regulators of stress and plant growth and their implication in signaling pathways is still partial. The crosstalk between NO and ROS during root formation offers new domains to be explored, as it regulates several plant functions. Previous findings indicate that plants utilize these signaling molecules for regulating physiological responses and development. Depending upon cellular concentration, NO either can stimulate or impede root system architecture (RSA) by modulating enzymes through post-translational modifications. Similarly, the ROS signaling molecule network, in association with other hormonal signaling pathways, control the RSA. The spatial regulation of ROS controls cell growth and ROS determine primary root and act in concert with NO to promote lateral root primordia. NO and ROS are two central messenger molecules which act differentially to upregulate or downregulate the expression of genes pertaining to auxin synthesis and to the configuration of root architecture. The investigation concerning the contribution of donors and inhibitors of NO and ROS can further aid in deciphering their role in root development. With this background, this review provides comprehensive details about the effect and function of NO and ROS in the development of RSA. 相似文献
49.
Hong Sung Hyun Singh Sudhir Tripathi Bhumi Nath Mondal Suvendu Lee Sangmin Jung Hyun Suk Cho Chuloh Kaur Shubhpreet Kim Jin-Hong Lee Sungbeom Bai Hyoung-Woo Bae Hyeun-Jong Lee Sang Yeol Lee Seung Sik Chung Byung Yeoup 《Protoplasma》2020,257(3):807-817
Protoplasma - Alkyl hydroperoxide reductase subunit F (AhpF) is a well-known flavoprotein that transfers electrons from pyridine nucleotides to the peroxidase protein AhpC via redox-active... 相似文献
50.
Singh Ashish Tripathi Pratibha Yadawa Arun Kumar Singh Sarika 《Neurochemical research》2020,45(8):1731-1745
Neurochemical Research - Parkinson’s disease (PD) is a slow progressive, second most common neurodegenerative disease characterized by the loss of dopaminergic neurons from the nigrostriatal... 相似文献