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51.
Mausumi Mutsuddi Debasish Mutsuddi A. S. Mukherjee Ashish K. Duttagupta 《Chromosoma》1984,89(1):55-62
The chromosome complement of hybrid males from the cross between Drosophila miranda female and D. persimilis male provides an interesting chromosomal situation where an autosome, the 3rd chromosome of D. persimilis, coexists with a homologue that developed into a sex chromosome, the X2 in D. miranda. Except for certain inversions and a few minor translocations, these two chromosomes (X2 and the 3rd) still look alike as polytene elements. However, in hybrid males pairing of the two chromosomes, the X2 and 3rd, is rare, while in female hybrids it occurs frequently. — 3H-TdR labeling shows that while the X2 and 3rd chromosomes replicate synchronously in hybrid female, in the hybrid male the former completes its replication earlier than the 3rd chromosome, as do the two arms of the X1 (XL and XR). The frequency and relative intensity of 3H-TdR labeling of each site of the X2 and that of the 3rd chromosome in hybrid males closely agree with those of the corresponding sites in the X2 of the miranda male and the 3rd chromosome of the persimilis male (or female), respectively. The results suggest that timing and rate of replication of the X2 are determined autonomously and follow the pattern in the respective parental species. 相似文献
52.
R Manjunath S I Chung A B Mukherjee 《Biochemical and biophysical research communications》1984,121(1):400-407
Uteroglobin, a progesterone induced, pregnancy related protein, can be incorporated into higher molecular weight proteins by human placental Factor XIIIa. This process is time dependent, requires CaCl2 and can be inhibited by the addition of polylysine, dansylcadavarine or histamine. Crosslinking of uteroglobin into higher molecular weight proteins can also be brought about by guinea pig liver transglutaminase. Such a process may be involved in the modification of epididymal spermatozoa to suppress their antigenicity. 相似文献
53.
Fluorodeoxyuridine (FUdR)-synchronized mouse L cells were allowed to incorporate 5-bromodeoxyuridine (BUdR) at restricted intervals in the S phase and the effects of the selective incorporation of BUdR in DNA on the activities of seven randomly chosen enzymes (five dehydrogenases and two phosphatases) were analysed. Reductions to 56.9 and 83.3 % of the control levels were noted for glucose-6-phosphate dehydrogenase (G6PD) and alcohol dehydrogenase (ADH) activities respectively, when cells were exposed to BUdR during the 1st h of S. Acid phosphatase (AcP) activity was reduced to 81.9% of the control level following exposure to the analogue during the 3rd h of S. Exposure of cells to BUdR for the entire S period failed to increase the magnitude of the reductions in activity for any of these three enzymes. Alternately, when cells were allowed to synthesize DNA in the presence of thymidine for the 1st h of S and the remainder in the presence of BUdR, the activities of G6PD and ADH were comparable to those found in untreated cells. Exposure of cells to thymidine for the 3rd h of S, combined with exposure to BUdR for the preceding and subsequent hours of S, provided complete protection against the BUdR-mediated reduction in AcP activity. The activities of lactate dehydrogenase (LDH), 6-phosphogluconate dehydrogenase (6pGD), isocitrate dehydrogenase (IDH) and alkaline phosphatase (A1P) were found to be insensitive to treatment with BUdR, even when the period of analogue exposure encompassed the entire S period.Additional investigations carried out with G6PD for characterization of the nature of the BUdR effects suggest that the BUdR-mediated reductions in enzyme activities are not caused by the increased rates of degradation of the enzymes, formation of enzyme inhibitors or by the disproportionate replication of A-T base pairs during BUdR treatment. The alterations of enzyme activities appear to result from decreased rates of synthesis of enzymes in BUdR-treated cells. The results of the present study clearly suggest that pulse labelling of cells with BUdR at various intervals of the S phase may provide a useful approach for determining temporal localization of replication time of DNA segments that are critical for the synthesis or regulation of specific gene products. 相似文献
54.
55.
56.
The petrol extract of the whole plant (aerial parts and roots) of Salvia lanata yielded a new triterpene acid, 3-epi-ursolic acid. 相似文献
57.
The sensitive plant Mimosa pudica is made insensitive by a brief treatment with colchicine. A high concentration of colchicine binding protein is present in the fresh actively moving leaves of M. pudica. This protein was partially characterized and compared with the animal brain tubulin. This colchicine binding activity is very low in the insensitive variety of Mimosa, namely Mimosa rubricaulis. 相似文献
58.
Wayne K. Hoffman Peter Lalley Jean Deb Butler Sheldon Orloff Joseph D. Schulman Anil B. Mukherjee 《In vitro cellular & developmental biology. Plant》1981,17(8):735-740
Summary Using lipochromosomes (phospholipid-entrapped chromosomes) we have transferred the human HGPRT gene into HGPRT deficient mouse
cells (A9) with a frequency of approximately 1×10−5 (Mukherjee et al., Proc. Natl. Acad. Sci. USA 75: 1361–1365; 1978). Two other genes located on the long arm of the human
X-chromosome were also expressed in two independently derived populations of transferents (A9/GT3 and A9/GT4). We report here
the chromosomal and enzymatic composition of human HGPRT-positive clones from each subpopulation analyzed in detail with alkaline
Giemsa-11 staining.
All the clones expressed human PGK and HGPRT, but one (A9/GT4C6) lacked human G6PD. In each of four clones examined microscopically,
a small piece of presumptive human chromatin was visible in the karyotypes of most cells. The chromatin fragment was free
or attached in each cell of an individual clone. When integrated, the human chromosomal fragment in each clone appeared associated
with the centromere of the same telocentric A9 chromosome (No. 6 by Q-banding).
These data suggest that: (a) substantial human chromosomal fragments can be transferred into recipient cells using the lipochromosome
technique; (b) clones from human HGPRT positive A9 transferent subpopulations may or may not possess other human X-linked
markers; (c) the stability of lipochromosomally transferred genes varied from clone to clone and stability is generally poor
in the absence of continuous selection pressure (e.g., HAT); (d) when multiple X-linked human genes were transferred to mouse
cells a cytologically detectable human chromosomal fragment was identified free or attached to a host chromosome; and (e)
integration of transferred human chromosomal material into mouse chromosomes may occur at preferential site(s) in the recipient
genome.
This research was sponsored in part by the Office of Health and Environmental Research U.S. Department of Energy under Contract
W-7405-eng-26 with the Union Carbide Corporation. 相似文献
59.
An IgG human monoclonal antibody that reacts with HIV-1/GP120, inhibits virus binding to cells, and neutralizes infection. 总被引:54,自引:0,他引:54
M R Posner T Hideshima T Cannon M Mukherjee K H Mayer R A Byrn 《Journal of immunology (Baltimore, Md. : 1950)》1991,146(12):4325-4332
A human mAb (HmAb) termed F105 was obtained by fusion of antibody-producing EBV-transformed cells with the HMMA2.11TG/O cell line. F105 is an IgG1 kappa antibody that binds to the surfaces of cells infected with all HIV-1 strains tested: MN, RF, IIIB, and SF2, but not uninfected cells. The HmAb immunoprecipitates GP120 from all four strains. F105 does not react with denatured GP120 on Western blots, but does react with viral lysates and purified GP120 dotted onto nitrocellulose filter paper under nondenaturing conditions. rGP120 from SF2 and soluble rCD4 inhibit antibody binding to infected cells in a dose-dependent manner. F105 inhibits the binding of free, infectious virions to uninfected HT-H9 cells with 50% of maximal (100%) inhibition at approximately 1 microgram/ml. F105 inhibits infection of HT-H9 cells by 100 tissue culture infective dose 50% units of MN and IIIB strains with 50% inhibition at concentrations of HmAb readily achievable in man. It appears that the F105 HmAb reacts with a conformationally defined epitope on HIV-1/GP120 that is exposed on the free virion and is important for binding to the cell surface by the virion. The epitope, which is immunogenic in humans, appears to be within, or topographically near, the CD4-binding site. F105 and the F105 epitope are potentially useful in therapy and in the design of peptide or anti-Id based vaccines; monitoring of the expression of the Id may prove useful in evaluating immune responses in infected individuals or vaccinated volunteers. 相似文献
60.
G Mukherjee D Banerjee D K Bhattacharya G C Chatterjee 《Indian journal of experimental biology》1990,28(6):550-552
Collagen stimulation of blood platelets resulted in significant increases in malondialdehyde (MDA) formation and activity of glucose-6-phosphate dehydrogenase (G6PDH) and a decrease in catalase and glutathione peroxidase (GPx). Retinoic acid (RA) pretreatment did not show any appreciable changes except for a decrease in G6PDH activity as compared with collagen alone. RA pretreatment of human blood platelets resulted in an increase in the activities of catalase and GPx, two important radical scavenging enzymes, with significant decrease in MDA formation when compared with ADP alone. It is suggested that RA has a significant effect on the antioxidant defence system in ADP stimulated platelets but not in the collagen stimulated platelets. 相似文献