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101.
102.
Gyeongho Seon Hyun Woo Joo Yong Jae Kim Juyi Park Yong Keun Chang 《Biotechnology progress》2019,35(1):e2729
Microalgal biomass was hydrolyzed using a solid acid catalyst with the aid of liquid acid. The use of solid acid as the main catalyst instead of liquid acid was to omit subsequent neutralization and/or desalination steps, which are commonly required in using the resulting hydrolysates for microbial fermentation. The hydrolysis of 10 g/L of lipid-extracted Chlorella vulgaris containing 12.2% carbohydrates using 7.6 g/L Amberlyst 36 and 0.0075 N nitric acid at 150°C resulted in 1.08 g/L of mono-sugars with a yield of 88.5%. For hydrolysis of higher concentrations of the biomass over 10 g/L, the amount of Amberlyst 36 needed to be increased in proportion to the biomass concentration to maintain similar levels of hydrolysis performance. Increasing the solid acid concentration protected the surface of the solid acid from being severely covered by cell debris during the reaction. A hydrolysate of lipid-extracted C. vulgaris 50 g/L was used, with no post-treatment of desalination, for the cultivation of Klebsiella oxytoca producing 2,3-butanediol. Cell growth in the hydrolysate was found to be almost the same as in the conventional medium with the same monosaccharide composition, confirming its fermentation compatibility. It was noticeable that the yield of 2,3-butanediol with the hydrolysate was observed to be 2.6 times higher than that with the conventional medium. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2729, 2019 相似文献
103.
The diphenyleneiodonium (DPI) is widely used as an inhibitor of flavoenzymes, particularly NADPH oxidase. In this study, we investigated the effect of DPI on the apoptosis of human RPE cells. DPI treatment in ARPE-19 cells evoked a dose- and time-dependent growth inhibition, and also induced DNA fragmentation and protein content of the proapoptotic factor Bax. In addition, DPI significantly induced the expression and phosphorylation of p53, which induces proapoptotic genes in response to DNA damage or irreparable cell cycle arrest. ROS have been implicated as a key factor in the activation of p53 by many chemotherapeutic drugs. Recent data on the regulation of intracellular ROS by DPI are controversial. Therefore, we analyzed whether DPI could contribute to the generation of intracellular ROS. Although there was increase in ROS level from cells treated for 24h with DPI, it was not detectable at early time points, required to induce p53 expression. And DPI-induced p53 expression was not affected by the ROS scavenger NAC. We conclude that DPI induces the expression of p53 by ROS-independent mechanism in ARPE-19 cells, and renders cells sensitive to drug-induced apoptosis by induction of p53 expression. 相似文献
104.
Metabolic profiling, metabolomic and metabonomic procedures for NMR spectroscopy of urine, plasma, serum and tissue extracts 总被引:2,自引:0,他引:2
Beckonert O Keun HC Ebbels TM Bundy J Holmes E Lindon JC Nicholson JK 《Nature protocols》2007,2(11):2692-2703
Metabolic profiling, metabolomic and metabonomic studies mainly involve the multicomponent analysis of biological fluids, tissue and cell extracts using NMR spectroscopy and/or mass spectrometry (MS). We summarize the main NMR spectroscopic applications in modern metabolic research, and provide detailed protocols for biofluid (urine, serum/plasma) and tissue sample collection and preparation, including the extraction of polar and lipophilic metabolites from tissues. 1H NMR spectroscopic techniques such as standard 1D spectroscopy, relaxation-edited, diffusion-edited and 2D J-resolved pulse sequences are widely used at the analysis stage to monitor different groups of metabolites and are described here. They are often followed by more detailed statistical analysis or additional 2D NMR analysis for biomarker discovery. The standard acquisition time per sample is 4-5 min for a simple 1D spectrum, and both preparation and analysis can be automated to allow application to high-throughput screening for clinical diagnostic and toxicological studies, as well as molecular phenotyping and functional genomics. 相似文献
105.
Arabidopsis mesophyll protoplasts: a versatile cell system for transient gene expression analysis 总被引:15,自引:0,他引:15
The transient gene expression system using Arabidopsis mesophyll protoplasts has proven an important and versatile tool for conducting cell-based experiments using molecular, cellular, biochemical, genetic, genomic and proteomic approaches to analyze the functions of diverse signaling pathways and cellular machineries. A well-established protocol that has been extensively tested and applied in numerous experiments is presented here. The method includes protoplast isolation, PEG-calcium transfection of plasmid DNA and protoplast culture. Physiological responses and high-throughput capability enable facile and cost-effective explorations as well as hypothesis-driven tests. The protoplast isolation and DNA transfection procedures take 6-8 h, and the results can be obtained in 2-24 h. The cell system offers reliable guidelines for further comprehensive analysis of complex regulatory mechanisms in whole-plant physiology, immunity, growth and development. 相似文献
106.
Pyrolysis mass spectrometry (PyMS) is a rapid, simple, high-resolution analytical method based on thermal degradation of complex
material in a vacuum, and has been widely applied to the discrimination of closely related microbial strains. Minimally prepared
samples of embryogenic and non-embryogenic calluses derived from various higher plants (sweet potato, morning glory, Korean
ginseng, Siberian ginseng, and balloon flower) were subjected to PyMS for spectral fingerprinting. A dendrogram based on the
unweighted pair group method, with arithmetic mean of pyrolysis mass spectra, divided the calluses into Siberian ginseng embryogenic
callus and the others, which were subsequently divided into embryogenic and non-embryogenic callus groups, regardless of plant
species from which the calluses were derived. In the non-embryogenic callus group, the dendrogram was in agreement with the
known taxonomy of the plants. These results indicate that PyMS analysis could be applied for discriminating plant calluses
based on embryogenic capacity and taxonomic classification. 相似文献
107.
Abstact Polar organisms should have mechanisms to survive the extremely cold environment. Four genes encoding cold-shock proteins,
which are small, cold-induced bacterial proteins, have been cloned from the Antarctic bacterium Streptomyces sp. AA8321. Since the specific functions of any polar bacterial or Streptomyces cold-shock proteins have not yet been determined, we examined the role of cold-shock protein A from Streptomyces sp. AA8321 (CspASt). Gel filtration chromatography showed that purified CspASt exists as a homodimer under physiological conditions, and gel shift assays showed that it binds to single-stranded, but not
double-stranded, DNA. Overexpression of CspASt in Escherichia coli severely impaired the ability of the host cells to form colonies, and the cells developed an elongated morphology. Incorporation
of a deoxynucleoside analogue, 5-bromo-2′-deoxyuridine, into newly synthesized DNA was also drastically diminished in CspASt-overexpressing cells. These results suggest that CspASt play a role in inhibition of DNA replication during cold-adaptation. 相似文献
108.
109.
High Performance Proteomics: 7th HUPO Brain Proteome Project Workshop March 7-9, 2007 Wellcome Trust Conference Centre, Hinxton, UK 总被引:1,自引:0,他引:1
Hamacher M Stephan C Eisenacher M Lewczuk P Wiltfang J Martens L Vizcaíno JA Kwon KH Yoo JS Park YM Beckers J Horsch M de Angelis MH Cho ZH Apweiler R Meyer HE 《Proteomics》2007,7(15):2490-2496
The Wellcome Trust Conference Centre at Hinxton, UK, was the meeting place of the 7th HUPO Brain Proteome Project Workshop entitled "High Performance Proteomics". It started on Wednesday, March 7, 2007 with a steering committee meeting followed by a two days series of talks dealing with the standardization and handling of tissues, body fluids as well as of proteomics data. The presentation and accompanying vivid discussions created a picture of actual strategies and standards in recent proteomics. 相似文献
110.
In the present study, we have investigated the proteome changes associated with glutamate-induced HT22 cell death, a model system to study oxidative stress-mediated toxicity. Among a number of HT22 proteins exhibiting altered expression, several molecular chaperones demonstrated substantial changes. For example, the levels of Hsp90 and Hsp70 decreased as cell death progressed whereas that of Hsp60 increased dramatically. Interestingly, cytosolic Hsp60 increased more prominently than mitochondrial Hsp60. Concomitantly, the accumulation of poly-ubiquitylated proteins and differential regulation of the peptidase activities and the subunits of 26S proteasomes were observed in glutamate-treated HT22 cells. Our findings that the molecular chaperones and the ubiquitin-proteasome system undergo changes during glutamate-induced HT22 cell death may suggest the importance of a protein quality control system in oxidative damage-mediated toxicity. 相似文献