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21.
Molecular genetics of cellular differentiation in leaves 总被引:2,自引:1,他引:1
22.
X. Preville P. Mehlen N. Fabre-Jonca S. Chaufour C. Kretz-Remy M. R. Michel A. -P. Arrigo 《Journal of biosciences》1996,21(2):221-234
The α-crystallin-related stress protein HSP27, which promotes cellular resistance to different types of stress, is constitutively
expressed during the growth of several primate tissue culture cells. Here, we report an analysis of the cellular localization
of this protein in CV-1 monkey cells. Following cell lysis and fractionation in the absence of detergent about 2 5 % of the
cellular content of HSP27 was recovered in the particu late fractions while the remaining of this protein was in the soluble
cytoplasmic fraction. This association of HSP27 with particulate fractions was no more observed when cells were lysed in the
presence of non-ionic detergent or when cells were pretreated with drugs, such as monensin and colcemid, that disrupt cytoskeletal
architecture. Immunofluorescence analysis revealed that HSP27 is concentrated in a polarized perinuclear zone of CV-1 cells
from where microtubules radiate. The particular locale of HSP27 was investigated in cells exposed to drugs or treatments,
such as monensin, colcemid, cold stess and serum starvation, that disrupt the cellular architecture of microtubules. A correlation
was observed between HSP27 cellular locale and microtubules integrity. Our results suggest a possible interaction of a fraction
of HSP27 with cytoplasmic organelles or structures, different from the Golgi apparatus, whose distribution depends upon the
organization of microtubules. 相似文献
23.
Colin Masters 《Molecular and cellular biochemistry》1996,165(2):83-93
The interactions between the omega-3 unsaturated fatty acids and peroxisomal function have been reviewed, in order to update and integrate knowledge in this area. Following a brief retrospective of the major clinical involvements of these fatty acids, the participation of the peroxisome in their metabolism has been appraised - the peroxisome being shown to exert a major influence on both the synthesis and degradation of the omega-3 fatty acids, with these effects flowing on to the widespread physiological implications of the derivative eicosanoids. Interactions between the omega-3 and omega-6 families of fatty acids have been discussed, as have the interdependent phenomena of peroxisome proliferation, membrane remodelling and cellular signalling. Amongst the signalling involvements covered were those of steroid hormone receptor superfamily, the phosphatidy1choline cycle, and the regulatory influences of oxygen free radicals. Comment has also been included on the separate biological roles of the individual omega-3 fatty acids, their influence on differential gene function, and on the molecular mechanisms of their pharmacological effects. It is concluded that the peroxisome is intimately involved in directing the metabolism and physiological influence of the omega-3 unsaturated fatty acids, and that this organelle merits much greater emphasis in future research aimed at unravelling the profound biological effects of these unique and multipotent compounds. 相似文献
24.
Large scale production of recombinant mouse and rat growth hormone by fed-batch GS-NSO cell cultures
Zhou W Bibila T Glazomitsky K Montalyo J Chan C Distefano D Munshi S Robinson D Buckland B Aunins J 《Cytotechnology》1996,22(1-3):239-250
Investigations of biological effects of prolonged elevation of growth hormone in animals such as mice and rats require large amounts of mouse and rat growth hormone (GH) materials. As an alternative to scarce and expensive pituitary derived materials, both mouse and rat GH were expressed in NSO murine myeloma cells transfected with a vector containing the glutamine synthetase (GS) gene and two copies of mouse or rat GH cDNA. For optimal expression, the mouse GH vector also contained sequences for targeting integration by homologous recombination. Fed-batch culture processes for such clones were developed using a serum-free, glutamine-free medium and scaled up to 250 L production scale reactors. Concentrated solutions of proteins, amino acids and glucose were fed periodically to extend cell growth and culture lifetime, which led to an increase in the maximum viable cell concentration to 3.5×109 cells/L and an up to 10 fold increase in final mouse and rat rGH titers in comparison with batch cultures. For successful scale up, similar culture environmental conditions were maintained at different scales, and specific issues in large scale reactors such as balancing oxygen supply and carbon dioxide removal, were addressed. Very similar cell growth and protein productivity were obtained in the fed-batch cultures at different scales and in different production runs. The final mouse and rat rGH titers were approximately 580 and 240 mg/L, respectively. During fed-batch cultures, the cell growth stage transition was accompanied by a change in cellular metabolism. The specific glucose consumption rate decreased significantly after the transition from the growth to stationary stage, while lactate was produced in the exponential growth stage and became consumed in the stationary stage. This was roughly coincident with the beginning of ammonia and glutamate accumulation at the entry of cells into the stationary stage as the result of a reduced glutamine consumption and periodic nutrient additions. 相似文献
25.
Using a blood cell separator, lymphocytes were collected from otherwise healthy convalescents suffering from herpetic infections.
A specific anti-herpes dialysate (AH-DLE) was prepared from the lymphocytes, using standard procedures. Patients with recurrent
herpetic infections were treated with a single dose of the dialysate, at the initial signs of herpetic infection (group A),
with two doses (group B) or with three doses (group C). A total number of 37 patients (29 women, 8 men, age range 15–73 years)
were treated. No improvement was observed in 7 patients (18.9%), whilst 7 patients did not manifest any exacerbation of their
herpetic infection in the course of the one-year follow-up. The remaining 62.2% of the patients showed a marked improvement:
decrease of the frequency and/or duration or relapses. Before AH-DLE administration, the mean number of herpes relapses in
this group of patients was 12 p.a.. After therapy, the number of relapses decreased to 3.5 p.a.. No statistically significant
difference was observed between groups A and B. The least favourable results were registered in group C. However, this group
included 6 female patients extremely resistant to the previously therapeutic attempts, including inosiplex, non-specific DLE
or acyclovir. Thus, even in this group, the therapy was successful in 50% of the patients. 相似文献
26.
M. T. Kidd M. A. Qureshi P. R. Ferket L. N. Thomas 《Biological trace element research》1994,42(3):217-229
The ability of dietary zinc-methionine (Zn-Met) to enhance mononuclear-phagocytic function againstSalmonella arizona andenteritids was investigated in young turkeys. Feed/gain and body wt gain at 21 d of age were not affected by Zn-Met. The addition of
30 or 45 ppm Zn from Zn-Met to a Zn adequate diet significantly increased cutaneous basophil hypersensitivity to phytohemagglutinin-P.
The clearance of intravenously administeredS. enteritidis from blood was not affected by 30 ppm of supplemental Zn from Zn-Met. However, 30 ppm Zn from Zn-Met increased the reduction
of intravenously administeredS. arizona from spleen. Percentages of myeloid and mononuclear-phagocytic cells before and afterS. enteritidis infection were not affected by supplemental Zn-Met. Turkeys supplemented with Zn-Met showed enhanced in vitro phagocytosis
ofS. enteritidis by Sephadex-elicited abdominal exudate cells. The phagocytosis ofS. arizona was unaffected by Zn-Met. 相似文献
27.
Gary C. du Moulin Zorina Pitkin Yuan-Jin Shen Evelyn Conti Jean Ko Stewart Carla Charles Dylan Hamilton 《Cytotechnology》1994,15(1-3):365-372
Somatic cell and gene therapy involve the application of biological technologies to an individual patient through the use of living cells which provide a therapeutic benefit (Aliski, 1991). Various forms of cellular and gene therapies are being developed and evaluated in an increasing number of clinical trials for congential and acquired disorders. The potential and progress of these therapeutic applications have resulted in an increasing effort by the Food and Drug Administration (FDA) to develop the regulatory framework under which these therapeutic approaches would insure safety and efficacy, the primary mandate of the FDA.Over five years ago Cellcor began to define the parameters, specifications, and conditions relevant to a Quality Assurance/Quality Control (QA/QC) program that has evolved to insure safety and maximize the efficacy of applications of the company'sex vivo technology, autolymphocyte therapy. Autolymphocyte therapy is an outpatient form of somatic cell immunotherapy based upon the infusion of T cells that have been activatedex vivo using a combination of previously generated autologous cytokines and an anti-CD3 monoclonal antibody.We have been able to demonstrate the feasibility for the safe, controlled, and consistent preparation and delivery of a cellular therapy by application of relevant GMP regulations. This presentation reviews aspects of this program and chronicles our experience which at present amounts to over 4400 infusions for over 700 patients. This program provides a high degree of assurance that a cellular therapy program can be carried out in a multisite mode involving hundreds of patients through the strict adherence to cGMP as set forth in existing regulations. It would be prudent that developers of cellular andex vivo gene therapies establish a similar cell processing and QA/QC infrastructure at an early developmental stage to optimize safety and reproducibility and facilitate regulatory review. 相似文献
28.
Sally Badawi Feda E. Mohamed Divya Saro Varghese Bassam R. Ali 《Traffic (Copenhagen, Denmark)》2023,24(8):312-333
Endoplasmic reticulum-associated protein degradation (ERAD) is a stringent quality control mechanism through which misfolded, unassembled and some native proteins are targeted for degradation to maintain appropriate cellular and organelle homeostasis. Several in vitro and in vivo ERAD-related studies have provided mechanistic insights into ERAD pathway activation and its consequent events; however, a majority of these have investigated the effect of ERAD substrates and their consequent diseases affecting the degradation process. In this review, we present all reported human single-gene disorders caused by genetic variation in genes that encode ERAD components rather than their substrates. Additionally, after extensive literature survey, we present various genetically manipulated higher cellular and mammalian animal models that lack specific components involved in various stages of the ERAD pathway. 相似文献
29.
C. Ronald Anderson Michael C. Flickinger 《Journal of industrial microbiology & biotechnology》1993,12(2):114-120
Summary A method is described to determine power of heat-time curves by conduction microcalorimetry in order to monitor the viability and ability of a thermotolerantBacillus strain to secrete acetic acid both during exponential growth and during stationary-phase. In this system secreted acetic acid is neutralized by an insoluble source of lime (dolime) which results in a poor correlation between optical density and culture dry weight. As an alternative, cells and residual dolime were rapidly resuspended in isothermal fresh medium with glucose in a conduction microcalorimeter. Heat evolution was rapid over a period of 200–800 s. Steady state heat evolution rate decreased as a function of culture time and did not correlate with: 1) specific growth rate: 2) viable cell number: 3) glucose consumption rate; or 4) acetic acid secretion rate. Glucose consumption and acetic acid secretion during the stationary growth phase were correlated with specific heat evolution rate. These initial results indicate that this technique may be useful for further development as an on-line flow or stopped-flow method to monitor the physiology of bacilli in response to nutrient depletion or growth inhibition. 相似文献
30.
Katherine Miclau William S. Hambright Johnny Huard Martin J. Stoddart Chelsea S. Bahney 《Aging cell》2023,22(1):e13759
Mesenchymal-derived stromal or progenitor cells, commonly called “MSCs,” have attracted significant clinical interest for their remarkable abilities to promote tissue regeneration and reduce inflammation. Recent studies have shown that MSCs' therapeutic effects, originally attributed to the cells' direct differentiation capacity into the tissue of interest, are largely driven by the biomolecules the cells secrete, including cytokines, chemokines, growth factors, and extracellular vesicles containing miRNA. This secretome coordinates upregulation of endogenous repair and immunomodulation in the local microenvironment through crosstalk of MSCs with host tissue cells. Therapeutic applications for MSCs and their secretome-derived products often involve in vitro monolayer expansion. However, consecutive passaging of MSCs significantly alters their therapeutic potential, inducing a broad shift from a pro-regenerative to a pro-inflammatory phenotype. A consistent by-product of in vitro expansion of MSCs is the onset of replicative senescence, a state of cell arrest characterized by an increased release of proinflammatory cytokines and growth factors. However, little is known about changes in the secretome profile at different stages of in vitro expansion. Some culture conditions and bioprocessing techniques have shown promise in more effectively retaining the pro-regenerative and anti-inflammatory MSC phenotype throughout expansion. Understanding how in vitro expansion conditions influence the nature and function of MSCs, and their associated secretome, may provide key insights into the underlying mechanisms driving these alterations. Elucidating the dynamic and diverse changes in the MSC secretome at each stage of in vitro expansion is a critical next step in the development of standardized, safe, and effective MSC-based therapies. 相似文献