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Baseline frequency of sister-chromatid exchanges (SCE) in newborn lymphocytes and its relationship to in vivo aging in humans 总被引:1,自引:0,他引:1
Heparinised cord blood from newborns and peripheral venous blood from three other age groups of individuals (1-75 years) have been cultured in vitro to obtain baseline frequencies of SCE and to see if the frequency of baseline SCE in vitro varies as a function of aging in vivo. The results demonstrate an age-dependent variation in the frequency of SCEs. Although the SCE frequency was lowest (5.10/cell) in 1-5-year-old infants, a significantly higher (P less than 0.001) frequency (8.97/cell) was observed in the cord blood of newborns. In old age, the level of SCE also increased. The plausible reason(s) for such observations is discussed. 相似文献
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S. K. Soni I. K. Sandhu K. S. Bath U. C. Banerjee P. R. Patnaik 《Folia microbiologica》1996,41(3):243-248
A strain of starch-assimilating yeast,Saccharomycopsis capsularis, isolated from Indian cereal-based fermented foods, produced significant levels of extracellular α-amylase and glucoamylase.
The enzymes reached their peak activities during the stationary phase at the end of the 5th and 4th day of cultivation, respectively.
The amylase yields were maximized by a proper choice of carbon and nitrogen sources, starting pH of the culture medium and
growth temperature. High activities of the enzymes were obtained through inexpensive agricultural commodities, such as wheat
bran and corn meal as carbon sources, and defatted soybean meal and peanut meal as nitrogen sources. A temperature of 28–32°C
and an initial pH of 4.5–5.0 were optimum. The crude amylase mixture could liquefy and saccharify a 1% starch solution completely
in 24 h at 50°C. 相似文献
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Requirement, uptake, and subcellular distribution of Na2 75SeO3 in the larvae of the insectC. cephalonica was investigated. That Se is well tolerated byC. cephalonica upto an added level of 2 ppm in the diet is suggested by the observed increase in body weight, total protein, and succinate dehydrogenase levels. Significant increases in the State 3 respiration ensued with Se supplementation up to 2 ppm in the mitochondrial oxidation of D-glycerol 1-phosphate, succinate and NADH, along with concomitant unaltered State 4 respiration, leading to enhanced RCR values. Maximal uptake of75Se was registered in the larvae maintained on basal diet when subjected to short-term exposure to 0.5 ppm75Se level. When exposure level was further increased up to 20 ppm, the observed decrease in the uptake of75Se suggested that Se status of larvae itself controlled the tissue uptake. Subcellular distribution pattern revealed maximal incorporation of75Se (cpm/g tissue) in the supernatant fraction, whereas, maximal specific75Se activity (cpm/mg protein) was associated with the mitochondrial fraction. Autoradiography of the soluble fractions indicated the presence of single selenoprotein in the larval group with short term 2 ppm75Se exposure. Inherent Se controls both the extent and the nature of distribution of mitochondrial75Se incorporation. Uptake of45Ca by the insect mitochondria was enhanced by dietary Se up to 2 ppm but was unaffected by addition ofin vitro 75Se in the medium. A more fundamental role for Se in the mitochondrial energy metabolism emerges from these studies. 相似文献
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The analysis of primary sequences from a protein sequence data base suggests that the sequences can be considered as examples
of constrained random fractals. Fractal dimensions of the positional distributions of the 20 residues along the chain have
been calculated. These fractal dimensions can be used as indices of intrinsic preferences of various residues. 相似文献
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Ambikesh Soni Manohar Prasad Bhandari Gagan Kant Tripathi Priyavand Bundela Pradeep Kumar Khiriya Purnima Swarup Khare Manoj Kumar Kashyap Abhijit Dey Balachandar Vellingiri Suresh Sundaramurthy Arisutha Suresh José M. Pérez de la Lastra 《Journal of cellular and molecular medicine》2023,27(6):737-762
In recent years, drug manufacturers and researchers have begun to consider the nanobiotechnology approach to improve the drug delivery system for tumour and cancer diseases. In this article, we review current strategies to improve tumour and cancer drug delivery, which mainly focuses on sustaining biocompatibility, biodistribution, and active targeting. The conventional therapy using cornerstone drugs such as fludarabine, cisplatin etoposide, and paclitaxel has its own challenges especially not being able to discriminate between tumour versus normal cells which eventually led to toxicity and side effects in the patients. In contrast to the conventional approach, nanoparticle-based drug delivery provides target-specific delivery and controlled release of the drug, which provides a better therapeutic window for treatment options by focusing on the eradication of diseased cells via active targeting and sparing normal cells via passive targeting. Additionally, treatment of tumours associated with the brain is hampered by the impermeability of the blood–brain barriers to the drugs, which eventually led to poor survival in the patients. Nanoparticle-based therapy offers superior delivery of drugs to the target by breaching the blood–brain barriers. Herein, we provide an overview of the properties of nanoparticles that are crucial for nanotechnology applications. We address the potential future applications of nanobiotechnology targeting specific or desired areas. In particular, the use of nanomaterials, biostructures, and drug delivery methods for the targeted treatment of tumours and cancer are explored. 相似文献
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K. Sudha Rani M. V. Swamy D. Sunitha D. Haritha G. Seenayya 《World journal of microbiology & biotechnology》1996,12(1):57-60
Two Clostridium thermocellum strains were improved for ethanol tolerance, to 5% (v/v), by gradual adaptation and mutation. The best mutant gave an ethanol yield of 0.37 g/g substrate, with a growth yield 1.5 times more than its parent. Accumulation of acids and reducing sugars by the mutant strain with 5% (v/v) ethanol was lower than that of the parent strain with 1.5% (v/v) ethanol. 相似文献
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