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101.
Regional localization of creatine phosphokinase BB was studied in postmortem human brain and its stability was shown. The content of CPK BB in different brain structures was unequal: from 0.5 mcg/mg of protein in the occipital lobe and tuber cinereum to 4.5 mcg/mg in the frontal lobe. In the regional localization of CPK BB in the postmortem brain of schizophrenia patients, some changes in isoenzyme content were found as compared to the control group. The reduction of CPK BB concentration at schizophrenia was found in the frontal lobe (45%, P less than 0.001) and s. nigra (70%, P less than 0.001); the concentration was higher in the thalamus and occipital lobe (15%, P less than 0.001), as well as in the parietal lobe, cingulate gyrus, tuber cinereum, cerebellum cortex, inferior olive--50-80%, P less than 0.001.  相似文献   
102.
DNA-Protein Complex in Circular DNA from Phage ϕ29   总被引:27,自引:0,他引:27  
THE DNA of the B. subtilis phage ?29 has been described as unpermuted linear duplex molecules1 of molecular weight 11 × 106, but the formation of circular molecules has also been indicated, suggesting the existence of cohesive ends1,2.  相似文献   
103.
104.
The complex proton spin-echo decay curve was recorded for human serum albumin (SA) solutions with different concentrations in normal and heavy water. The curve included three fast-decaying components for SA, in addition to the slow-decaying component for the water. The total amplitude of these three components roughly corresponded to the number of protons in the SA (with isotopic exchange taken into account); the component ratio remained constant at different concentrations and different temperatures between 4 and 39 degrees. The relatively slow-decaying protein component, which accounted for similar to 10% of the SA protons, was produced by the side chains of the protein. The presence of two other faster-decaying SA components with approximately equal amplitudes indicated that only about half of the remaining protons in the SA macromolecule are incorporated into the comparatively rigid globule, the other half belonging to groups with high conformational lability in aqueous solution. The activation energy for the aqueous component was close to that for pure water, while the activation energies for the protein components were roughly twice as large.  相似文献   
105.
A 501 bp caf1 gene fragment and a 443 bp of pla gene fragment carried by 100 kb (pFra) and 10 kb (pPst) species-specific extrachromosomal replicons, respectively, were used as targets to study the conditions under which DNA amplification by polymerase chain reaction (PCR) may be applied to detect and identify Yersinia pestis DNA in cell lysates of pure cultures and biological samples. The sensitivity limit of PCR with the crude cell lysates of Y. pestis EV was estimated as 10–50 cfu in reaction mixture. When target Y. pestis EV cells were mixed with fresh blood of white mice, which contained 0.4% potassium citrate, the PCR detection level varied from 400 to 100 cfu ml-1 of blood depending on the method used for preparing the sample. In our tests PCR was effective for the detection of yersinia in the blood of white laboratory mice experimentally infected with virulent Y. pestis KM638 strain. This method can be considered convenient for routine detection and identification of Y. pestis.  相似文献   
106.
It has been shown that the effects of stimulation of germination of wheat seeds by electromagnetic field depend on the degree of membrane tension during imbibition of seeds in sucrose solutions. This provides further confirmation of the influence of electromagnetic fields on the release of proteins from the bound state on the membranes. The prolonged treatment with electromagnetic fields during the imbibition of seeds leads not only to the inhibition of germination of sprouts but also to a decrease in their germinability, which can be as strong as twofold for seeds with the initial low germinability. This is related to the desynchronization of germination processes, caused by the stimulation of the release of proteins and inhibition of another stage during the cell division, the assembly of complex structures. It is noted that the activation of the release of proteins and inhibition of their binding by the action of electromagnetic fields must elevate the cell excitability. The presumably, the excitability of cells determines the effects of magnetic storms and high solar activity on the physiological state of organisms.  相似文献   
107.
Physical connections between mitotic chromosomes have been reported previously. It was assumed that the interchromosome connection was based on the DNA-protein thread. However, the data about DNA sequences and protein component in the thread is fragmentary. We demonstrated on the mouse cultured cell line and prematurely condensed chromosomes that: (a) all four mouse satellite DNA fragments (major and minor satellite, mouse satellite 3 (MS3) and mouse satellite 4 (MS4)) were involved in the thread formation; (b) MS4 was involved in the thread to the least extent among all the other fragments; (c) telomere was never a member of the thread; (d) the thread was synthesized at a late G(2) phase; (e) RNA helicase p68 and CENP-B were among the protein components of the interchromosome connection. It was shown by FACS analysis that in mouse and human cell lines: (1) the flow karyotype spectrums were never free from chromosome aggregates; (2) chromosome association did not depend on the chromosome length and each chromosome was free to associate with the other.  相似文献   
108.
The SOS response in Escherichia coli is induced after DNA-damaging treatments including ultraviolet light. Regulation of the SOS response is accomplished through specific interaction of the two SOS regulator proteins, LexA and RecA. In ultraviolet light-treated cells, nucleotide excision repair is the major system that removes the induced lesions from the DNA. Here, induction of the SOS response in Escherichia coli with normal and impaired excision repair function is studied by simulation of intracellular levels of regulatory LexA and RecA proteins, and SulA protein. SulA protein is responsible for SOS-inducible cell division inhibition. Results of the simulations show that nucleotide excision repair influences time-courses of LexA, RecA and SulA induction by modulating the dynamics of RecA protein distribution between its normal and SOS-activated forms.  相似文献   
109.
V Babich  N Aksenov  V Alexeenko  S L Oei  G Buchlow  N Tomilin 《Gene》1999,239(2):341-349
Short interspersed repeats of the Alu family located in promoters of some human genes contain high-affinity binding sites for thyroid hormone receptor, retinoic acid receptor and estrogen receptor. The standard binding sites for the receptors represent variants of duplicated AGGTCA motif with different spacing and orientation (direct, DR, or inverted, IR), and Alu sequences were found to have functional DR-4, DR-2 or variant IR-3/IR-17 elements. In this study we analyzed distribution and abundance of the elements in a set of human genomic sequences from GenBank and their association with Alu repeats. Our results indicate that a major fraction of potentially active DR-4, DR-2 and variant IR-3/IR-17 elements in the genes is located within Alu repeats. Alu-associated DR-2 elements are conserved in primate evolution. However, very few Alu have potential DR-3 glucocorticoid-response elements. Gel-shift experiments with the probe (AUB) corresponding to the consensus Alu sequence just upstream of the RNA polymerase III promoter B-box and containing duplicated AGGTCA motif indicate that the probe interacts in a sequence-specific manner with human nuclear proteins which bind to standard IR-0, DR-1, DR-4 or DR-5 elements. The AUB sequence was also able to promote thyroid hormone-dependent trans-activation of a reporter gene. The results support the view that Alu retroposons played an important role in evolution of regulation of the primate gene expression by nuclear hormone receptors.  相似文献   
110.
We document that the cricket, Acheta domesticus, avoids “necromone” chemical cues of death associated with treated surfaces and shelters (i.e., ethanol extracts of cricket bodies, oleic acid or linoleic acid). Initially we tested male responses to male body extract, oleic acid, or linoleic acid associated with shelters. Body extract was more repellent than either oleic or linoleic acid at a dose of 10 body equivalents per shelter. At 15 or 20 body equivalents/shelter extract and oleic acid were similarly repellent but linoleic acid was weaker. We next tested responses of males or females to shelters and surfaces treated with body extracts of males, females, a male-female mixture, or oleic acid. Repellency was evaluated at 1, 16, and 22 h following introduction. Body extracts elicited more immediate aversion than did authentic oleic acid (1 h). Females showed declining aversion with time (1, 16, 22 h), especially with regard to male extract. Alternatively, males showed increasing aversion with time, particularly to female extract. Both sexes showed weak responses to oleic acid at 1 h, but significant aversion at 16 and 22 h. We suggest that females may be less risk aversive as they seek out singing males holding established territories (i.e., mobility makes risk transient). Alternatively, males may respond more strongly to female necromone as this would reduce attraction of females to their territory. Finally, we consider a classic paper that documents a strong cricket repellent associated with tissue-covered perches. We provide new evidence that this repellent was likely an unsaturated fatty acid.  相似文献   
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