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261.
Sah NK Singh SN Sahdev S Banerji S Jha V Khan Z Hasnain SE 《Journal of biosciences》2005,30(4):499-505
Selaginella bryopteris is a lithophyte with remarkable ressurection capabilities. It is full of medicinal properties, hence also known as ‘Sanjeevani’ (one that infuses life). For lack of credible scientific evidence the plant is not in active use as a medicinal herb. We
provide scientific evidence for whyS. bryopteris is known as ‘Sanjeevani’.
The aqueous extract ofS. bryopteris possesses growth-promoting activity as well as protective action against stress-induced cell death in a number of experimental
cell systems including mammalian cells. Treatment of the cells in culture with 10% aqueous extract enhanced cell growth by
about 41% in Sf9 cells and 78% in mammalian cells. Pre-treatment of cells with the Selaginella extract (SE) (1-2x5%) protected
against oxidative stress (H2O2)-induced cell death. The killing potential of ultra violet (UV) was also significantly reduced
when the cells were pre-treated with SE for 1 h. Thermal radiation suppressed cell growth by about 50%. Pre-treatment of cells
with SE for 1 h afforded complete protection against heat-induced growth suppression. SE may possess anti-stress and antioxidant
activities that could be responsible for the observed effects. Chemical analysis shows that SE contains hexoses and proteins.
Taken together,S. bryopteris extract may help in stress-induced complications including those due to heat shock. 相似文献
262.
Dubey VK Lee J Blaber M 《Protein science : a publication of the Protein Society》2005,14(9):2315-2323
Previous reports detailing mutational effects within the hydrophobic core of human acidic fibroblast growth factor (FGF-1) have shown that a symmetric primary structure constraint is compatible with a stably folded protein. In the present report, we investigate symmetrically related pairs of buried hydrophobic residues in FGF-1 (termed "mini-cores") that are not part of the central core. The effect upon the stability and function of FGF-1 mutations designed to increase primary structure symmetry within these "mini-core" regions was evaluated. At symmetry-related positions 22, 64, and 108, the wild-type protein contains either Tyr or Phe side chains. The results show that either residue can be readily accommodated at these positions. At symmetry-related positions 42, 83, and 130, the wild-type protein contains either Cys or Ile side chains. While positions 42 and 130 can readily accommodate either Cys or Ile side chains, position 83 is substantially destabilized by substitution by Ile. Tertiary structure asymmetry in the vicinity of position 83 appears responsible for the inability to accommodate an Ile side chain at this position, and is known to contribute to functional half-life. A mutant form of FGF-1 with enforced primary structure symmetry at positions 22, 64, and 108 (all Tyr) and 42, 83, and 130 (all Cys) is shown to be more stable than the reference FGF-1 protein. The results support the hypothesis that a symmetric primary structure within a symmetric protein superfold represents a solution to achieving a foldable, stable polypeptide, and highlight the role that function may play in the evolution of asymmetry within symmetric superfolds. 相似文献
263.
M.?P.?Sapre H.?Jha M.?B.?PatilEmail author 《World journal of microbiology & biotechnology》2005,21(5):649-654
Summary An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic Bacillus sp. The molecular weight of the purified xylanase was 44 kDa, as analysed by SDS/PAGE. The enzyme reaction followed Michaelis–Menten kinetics with Kmapp and Vmax values of 0.025 mg/ml and 450 U/mg protein, respectively, as obtained from a Lineweaver–Burk plot. The xylanase contained no other enzyme activity except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 50 °C. The optimum pH for the xylanase activity was at three peaks 6.5, 8.5 and 10.5, respectively and the enzyme was stable over a broad range of pH from pH 6 to 10.5. Metal ions tested with demetalized enzyme had no effect, with the exception of Hg2+ and Pb2+ (both strong inhibitors). Inhibition of the enzyme activity by N-bromosuccinimide (amino acid modifier) indicated the role of tryptophan residues in the catalytic function of the enzyme. Due to these outstanding properties, the xylanase of Bacillussp. finds potential applications in biopulping, biobleaching and de-inking of recycled paper and other industrial processes. 相似文献
264.
265.
Srikanth K Kumar CA Goswami D De AU Jha T 《Indian journal of biochemistry & biophysics》2001,38(1-2):120-123
As a part of a composite programme of rational drug design (RDD), we had synthesized some substituted benzenesulphonyl glutamines and evaluated their inhibitory activities against Ehrlich Ascites Carcinoma (EAC) cell line in Swiss albino mice. Quantitative structure activity relationship (QSAR) studies of these inhibitory activities using Fujita-Ban model as well as Modified Hansch-Fujita model gave excellent correlations (correlation coefficient r = 0.89 and 0.82 respectively). These results could be useful in designing 'lead' compound with potent inhibitory activity on DNA and RNA synthesis and tumour development. 相似文献
266.
267.
268.
Manoj Kumar Puja Kumari Nitin Trivedi Mahendra K. Shukla Vishal Gupta C. R. K. Reddy Bhavanath Jha 《Journal of applied phycology》2011,23(5):797-810
Twenty-two tropical seaweeds from the Rhodophyta, Phaeophyta and Chlorophyta were examined for their possible use as nutritional
supplements. All seaweeds contained balanced Na/K and C/N ratio and high amounts of macroelements (Na, K, Ca, and Mg) as compared
to the terrestrial vegetables. Among the microelements, Fe was the highest followed by Zn, Mn, Cu and other trace elements.
Fatty acid distribution showed high level of n-6 and n-3 polyunsaturated fatty acids (PUFAs), and their ratios were within
the WHO prescribed limits. The higher ratios of PUFA/SFA (>0.4) are in agreement with the recommendations of nutritional guidelines.
Most of the species, especially the Chlorophyta and Phaeophyta, had permissible intake values of unsaturation, atherogenic
and thrombogenic indexes comparable to milk-based products. Principal component analysis demonstrated a correlation between
total phenolic content, total antioxidant activity, DPPH, and O2•− radical scavenging activity, suggesting polyphenols as the chief contributor to the antioxidant activity in seaweeds. These
results indicate that these seaweeds could be a potential source of natural antioxidants, minerals and high-quality PUFAs
and may be efficiently used as ingredients in functional foods. 相似文献
269.
Vikash Kumar 《Carbohydrate research》2010,345(11):1564-1569
A computational study on the glycoside hydrolase 13 (GH13) family of the CAZy database has been carried out at the atomic level in order to identify the conserved positions that may be responsible for recognition of the substrate. Analysis with substrate analog-, inhibitor-, or product-bound 3D structures was carried out to find the atomic spatial arrangement of the amino acids that make −2, −1, +1, and +2 subsites and water oxygen atoms around the ligand. The identified conserved positions of subsites were independent from the nature of the amino acid. The −1 and +1 subsites have more conserved positions than the −2 and +2 subsites. Some of the clusters of the −1 and +1 subsites have atoms of the same chemical nature. A spatially conserved position for water, which is stabilized by a hydrogen bond with the carboxyl group of a proton donor (Glu) and Asp of the catalytic triad, was found in the −1 subsite of 75% of the enzymes subjected to analysis. This position could be the region of hydrolytic water. 相似文献
270.
Nabanita Chatterjee Subhadip Das Dipayan Bose Somenath Banerjee Tarun Jha Krishna Das Saha 《PloS one》2015,10(3)
The microbial source, which includes live, attenuated, or genetically modified microbes or their cellular component(s) or metabolites, has gained increasing significance for therapeutic intervention against several pathophysiological conditions of disease including leukemia, which remains an incurable disease till now despite recent advances in the medical sciences. We therefore took up the present study to explore if the leishmanial lipid (pLLD) isolated from L. donovani can play an anti-neoplastic role in acute myeloid leukemia cells by regulating cellular growth. Indeed pLLD significantly inhibited cell proliferation of four AML cell lines (HL-60, MOLT-4, U937, and K562). Scanning electron microscopy and DNA fragmentation analysis revealed that it significantly induced apoptosis of U937 cells through morphological alteration. Occurrence of apoptosis was checked by using Annexin exposure and this established that the cell cycle was arrested at G0/G1 phase in time-dependent manner. pLLD increased the intracellular ROS with alteration of mitochondrial membrane potential, as detected using DCFDA. It also regulated the expression of apoptosis-related proteins like Bax, Bcl2, Bad and t-Bid besides causing cleavage of PARP as determined by western blot analysis. Treatment of U937 cells with pLLD induced the activation of extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK)1/2, p38, and caspases 9/3. The results suggest that pLLD induces apoptosis in acute myeloid leukemia cells possibly via increasing intracellular ROS and regulating the MAPK pathway. 相似文献