全文获取类型
收费全文 | 539篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
570篇 |
出版年
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 19篇 |
2015年 | 25篇 |
2014年 | 28篇 |
2013年 | 53篇 |
2012年 | 57篇 |
2011年 | 44篇 |
2010年 | 32篇 |
2009年 | 17篇 |
2008年 | 29篇 |
2007年 | 14篇 |
2006年 | 28篇 |
2005年 | 24篇 |
2004年 | 38篇 |
2003年 | 21篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有570条查询结果,搜索用时 0 毫秒
21.
Pramod Sukumaran Max L?nnfors Otto L?ngvik Ilari Pulli Kid T?rnquist J. Peter Slotte 《PloS one》2013,8(4)
Ceramides are potent bioactive molecules in cells. However, they are very hydrophobic molecules, and difficult to deliver efficiently to cells. We have made fluid bilayers from a short-chain D-erythro-ceramide (C6-Cer) and cholesteryl phosphocholine (CholPC), and have used this as a formulation to deliver ceramide to cells. C6-Cer complexed with CholPC led to much larger biological effects in cultured cells (rat thyroid FRTL-5 and human HeLa cells in culture) compared to C6-Cer dissolved in dimethyl sulfoxide (DMSO). Inhibition of cell proliferation and induction of apoptosis was significantly more efficient by C6-Cer/CholPC compared to C6-Cer dissolved in DMSO. C6-Cer/CholPC also permeated cell membranes and caused mitochondrial Ca2+ influx more efficiently than C6-Cer in DMSO. Even though CholPC was taken up by cells to some extent (from C6-Cer/CholPC bilayers), and was partially hydrolyzed to free cholesterol (about 9%), none of the antiproliferative effects were due to CholPC or excess cholesterol. The ceramide effect was not limited to D-erythro-C6-Cer, since L-erythro-C6-Cer and D-erythro-C6-dihydroCer also inhibited cell priolifereation and affected Ca2+ homeostasis. We conclude that C6-Cer complexed to CholPC increased the bioavailability of the short-chain ceramide for cells, and potentiated its effects in comparison to solvent-dissolved C6-Cer. This new ceramide formulation appears to be superior to previous solvent delivery approaches, and may even be useful with longer-chain ceramides. 相似文献
22.
23.
24.
Shikha Lohan Kaisar Raza Saloni Singla Sanjay Chhibber Sheetu Wadhwa O. P. Katare Pramod Kumar Bhupinder Singh 《AAPS PharmSciTech》2016,17(5):1042-1048
Carbon nanotubes (CNTs), owing to their inherently unique properties in the domain of biomedical sciences including drug delivery, offer an exciting platform to the researchers. Of late, their applications have also been successfully established. Recently, single-walled CNTs (SWCNTs) have been explored for antibacterial efficacy, but naïve multi-walled CNTs (MWCNTs) still remained unearthed. The present studies endeavor the investigation of the potential of various non-ionic surfactants in solubility enhancement of MWCNTs and their subsequent antibacterial efficacy against Escherichia coli and Staphylococcus aureus. Polysorbates offer more solubility to MWCNTs vis-à-vis the phospholipids. However, the antibacterial effect was found to be less influenced by solubility but significantly determined by the type of surfactant. Transmission electron photomicrographs confirmed significant adhesion of MWCNTs to the bacterial walls only in the presence of unsaturated phospholipids and this was expressed in the form of lowest minimum inhibitory concentration (MIC) values of MWCNTs dispersed with the same. The findings are unique as MWCNTs were found to be active against both Gram-negative and Gram-positive bacteria to a similar extent, though somewhat milder than SWCNTs. However, when dispersed with unsaturated phospholipids, the former offer almost comparable antibacterial effects to that of the latter. The study opens a new research domain to further explore the antibacterial effects of non-functionalized and relatively safer MWCNTs, accentuating the importance of biocomponents like unsaturated phospholipids in this purview. 相似文献
25.
Agrawal PB Nierstrasz VA Klug-Santner BG Gübitz GM Lenting HB Warmoeskerken MM 《Biotechnology journal》2007,2(3):306-315
A rational approach has been applied to design a new environmentally acceptable and industrially viable enzymatic scouring process. Owing to the substrate specificity, the selection of enzymes depends on the structure and composition of the substrate, i.e. cotton fibre. The structure and composition of the outer layers of cotton fibre has been established on the basis of thorough literature study, which identifies wax and pectin removal to be the key steps for successful scouring process. Three main issues are discussed here, i.e. benchmarking of the existing alkaline scouring process, an evaluation of several selected acidic and alkaline pectinases for scouring, and the effect of wax removal treatment on pectinase performance. It has been found that the pectinolytic capability of alkaline pectinases on cotton pectin is nearly 75% higher than that of acidic pectinases. It is concluded that an efficient wax removal prior to pectinase treatment indeed results in improved performance in terms of hydrophilicity and pectin removal. To evaluate the hydrophilicity, the structural contact angle (theta) was measured using an auto-porosimeter. 相似文献
26.
Ansuman Panda Debashis Jena Mrinal Kanti Datta Janmejay Parhi Radhakrishnan Kizhakke Veettil Pramod Kumar Pandey 《Zeitschrift fur angewandte Ichthyologie》2019,35(6):1242-1248
The present study explains the intraspecific variation in Indian Hill trout (Barilius bendelisis) on the basis of image based truss network system and D‐loop region of mtDNA. A total of 210 samples were collected from three different rivers (Teesta, Kameng and Myntudu River) of North East India in Indo‐Burma Biodiversity Hotspot. By using the software applications (tpsDig version 2.1 and PAST), a total of 25 morphometric measurements were generated from 10 landmarks. The Analysis of Variance (ANOVA), Factor Analysis (FA) and Discriminate Function Analysis (DFA) showed, out of the total variations, factor 1 explained 46.74% while factor 2 and factor 3 explained 27.14% and 11.92%, respectively. Using these variables 83.33% of the cross‐validated specimens were classified into distinct groups. Analysis of Molecular Variance (AMOVA) and pairwise Fst value for D‐loop region of mtDNA also showed high to medium level of genetic variation among the stocks and within the stocks. We conclude that the observed discrete stocks might be the result of changing environmental conditions in different rivers of the hotspot as the rivers are present at different altitudinal labels. It is also believed that the variation might be due to the construction of barrages across the river which hinder the mixing among the stocks. 相似文献
27.
Mishra Aradhana Singh Satyendra Pratap Mahfooz Sahil Shukla Richa Mishra Nishtha Pandey Shipra Dwivedi Sanjay Pandey Vivek Shirke Pramod Arvind Nautiyal Chandra Shekhar 《Plant Molecular Biology Reporter》2019,37(5-6):499-499
Plant Molecular Biology Reporter - The original version of this article unfortunately contained missing information at author’s affiliations. The affiliation address of the author’s... 相似文献
28.
29.
The success of P. juliflora, an evergreen woody species has been largely attributed to temperature acclimation and stomatal control of photosynthesis
under wide range of environmental conditions prevalent in India. We studied the contribution of the enzyme ribulose-1,5 bisphosphate
carboxylase/oxygenase (Rubisco) in diurnal and seasonal photosynthesis changes in P. juliflora. The changes observed in photosynthesis under natural conditions could be effected by the growth temperatures, which ranged
from 10–30 °C in winter to 30–47 °C in summer. However, the Total Rubisco activity displayed a constant diurnal pattern and
showed a maximum at 1200 in all seasons namely spring, summer, monsoon and winter irrespective of the changes in temperature.
The Total Rubisco activity from two cohorts of leaves produced in spring and monsoon appeared to be down-regulated differentially
at low PPFD during the evening. The in vivo and in vitro measurements of carboxylation efficiency of Rubisco showed wide variation during the day and were correlated with the photosynthesis
rate. The light activation of Rubisco showed the acclimation to moderately high temperatures in different seasons except in
summer. The exceptionally high temperatures (>45 °C) in summer, though not affecting Total activity, severely inhibited the
light activation of Rubisco and also modulated the recovery process for the activation of Rubisco. Our studies suggest that
the modulation of Rubisco driven by Rubisco activase and not Rubisco per se was crucial for the diurnal regulation of photosynthesis.
NBRI Publication No.: 528 相似文献
30.