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911.
912.
Lichtner M Mengoni F Mastroianni CM Sauzullo I Rossi R De Nicola M Vullo V Ghibelli L 《Apoptosis : an international journal on programmed cell death》2006,11(5):781-787
The reduction of neutrophils apoptosis is one of the main non-virological effects of protease inhibitor (PI) therapy. We explore
here whether this may be due to the cross-inhibition of calpain, an important non-virological target of PI in vitro. We found that the high basal level of neutrophils apoptosis in AIDS patients is strictly related to an increased intracellular
calpain activity. Both alterations disappear after PI treatment, with apoptosis and calpain going back to normal levels after
3 months of PI therapy, independently of a proficient antiviral effect. PI drugs exerted a similar antiapoptotic and anticalpain
effects on neutrophils in ex vivo experiments: strikingly, the effects were mimicked by commercially available calpain inhibitors. This study shows, for the
first time, that apoptosis of neutrophils in AIDS patients is mediated by calpain, and that neutrophil survival in PI treated
AIDS patients is a non virological effect due to calpain inhibition.
Miriam Lichtner and Fabio Mengoni are equally contributed. 相似文献
913.
Dondero F Rossi T Delfino M Imbrogno N Cannistrà S Mazzilli F 《Cell and tissue banking》2006,7(1):61-64
The aim of our study was to evaluate the bio-kinetic characteristics of human semen refrigerated for different periods and
to compare the effects of refrigeration at +4 °C against cryopreservation of human sperm at −196 °C. Semen was obtained from
30 male partners of infertile couples (infertile subjects) with the following semen profile: sperm count ≥10 × 106/ml; progressive motility ≥20%; atypical forms <70% and white blood cells <1.0 × 106/ml. Fifteen normospermic subjects were also selected as controls (control subjects). The following tests were carried out
on basal, refrigerated and cryopreserved sperm: a) sperm kinetic properties (by Superimposed Image Analysis System); b) the
Hypoosmotic Viability Test (HVT) (combined Hypoosmotic Swelling and Viability Test). The results of the study showed that
the percentage recovery of kinetic properties and of HVT were optimum for up to 48 h. After refrigeration for 72 h, a drastic
decrease in straight motility recovery was observed. No significant differences were observed between cryopreservation and
refrigeration at +4 °C for 48 h for motility or HVT recoveries in samples from control subjects. However, in infertile subjects,
a significant decrease in straight progressive motility and HVT recoveries was observed in cryopreserved samples compared
to those refrigerated for 48 h. Neither refrigeration nor cryopreservation led to the growth of pathogenic bacteria in any
of the cases studied. Based on the above results, refrigeration could represent a useful alternative to the cryopreservation
method. 相似文献
914.
IL-10 has been suggested as a possible parameter for human African trypanosomiasis stage determination. However, conclusive experimental studies have not been carried out to evaluate this, which is a prerequisite before a potential test can be validated in humans for diagnostic purposes. We used the vervet monkey model of trypanosomiasis to scrutinize IL-10 in blood and cerebrospinal fluid (CSF). Five adult males were experimentally infected with T. b. rhodesiense. The infected animals became anemic and exhibited weight loss. Parasitemia was patent after 3 days and fluctuated around 3.7 × 107 trypanosomes/ml throughout the experimental period. The total CSF white cell counts increased from pre-infection means around 3 cells/μl to a peak of 30 cells/μl, 42 days post-infection (DPI). IL-10 was not detectable (< 2 pg/ml) in serum prior to infection. IL-10 serum concentrations increased to 273 pg/ml 10 DPI coinciding with the first peak of parasitemia. Thereafter the levels declined to a mean value of 77 pg/ml 34 DPI followed by a significant rise to a second peak of 304 pg/ml (p < 0.008) 42 DPI. There was no detectable IL-10 in CSF. IL-10 synthesis is thus stimulated both in the early and transitional stages of experimental trypanosomiasis. That IL-10 is produced in early stage disease is an interesting finding unlikely to be detected in humans where it is difficult to determine the exact time of infection. The IL-10 peak observed on day 42 of infection might indicate onset of parasite neuroinvasion coinciding with a peak in white blood cell counts in the blood and CSF. 相似文献
915.
Lack of direct DNA damage in human blood leukocytes and lymphocytes after in vitro exposure to high power microwave pulses 总被引:3,自引:0,他引:3
Chemeris NK Gapeyev AB Sirota NP Gudkova OY Tankanag AV Konovalov IV Buzoverya ME Suvorov VG Logunov VA 《Bioelectromagnetics》2006,27(3):197-203
Currently, the potential genotoxicity of high power microwave pulses (HPMP) is not clear. Using the alkaline single cell gel electrophoresis assay, also known as the alkaline comet assay, we studied the effects of HPMP (8.8 GHz, 180 ns pulse width, peak power 65 kW, pulse repetition frequency 50 Hz) on DNA of human whole-blood leukocytes and isolated lymphocytes. The cell suspensions were exposed to HPMP for 40 min in a rectangular waveguide. The average SAR calculated from the temperature kinetics was about 1.6 kW/kg (peak SAR was about 300 MW/kg). The steady-state temperature rise in the 50 microl samples exposed to HPMP was 3.5 +/- 0.1 degrees C. In independent experiments, we did not find any statistically significant DNA damage manifested immediately after in vitro HPMP exposure of human blood leukocytes or lymphocytes or after HPMP exposure of leukocytes subsequently incubated at 37 degrees C for 30 min. Our results indicate that HPMP under the given exposure conditions did not induce DNA strand breaks, alkali-labile sites, and incomplete excision repair sites, which could be detected by the alkaline comet assay. 相似文献
916.
- 1.
- The definition of clo unit was briefly reviewed in this paper. 相似文献
917.
KDN (Deaminoneuraminic acid, or deaminated neuraminic acid) is a minor but biosynthetically independent member of the sialic
acid. Human occurrence of KDN has already been established, although its level is so little that it is often undetectable
by conventional sialic acid analysis. Elevated expression of KDN in fetal cord blood cells and some malignant tumor cells
have been reported. However, in mammalian cells and tissues KDN mostly occurs as the free sugar and little occurred conjugated
to glycolipids and/or glycoproteins. A positive correlation between the ratio of free KDN/free Neu5Ac in ovarian adenocarcinomas
and the stage of malignancy has been noted for diagnostic use. We hypothesized that elevated expression of KDN in mammalian
systems may be closely related to elevated activities of enzymes involved in the formation of sialoglycoconjugates and/or
aberrant supply of the precursor sugar, mannose, used in the biosynthesis of KDN. In this study we used human ovarian teratocarcinoma
cells PA-1 to further analyze KDN expression in human cells. Major findings reported in this paper are, (i) a 30 kDa KDN-glycoprotein
immunostainable with monoclonal antibody, mAb.kdn3G, (specific for the KDNα2 → 3Galβ1→ epitope) and sensitive to KDNase was
identified in the membrane fraction of the cell: (ii) a 49 kDa KDN-glycoprotein that is not reactive with mAb.kdn3G but is
sensitive to KDNase was identified in the soluble fraction: and (iii) PA-1 cells showed unique response to mannose added to
the growth medium in that the levels of both free and bound forms of KDN are elevated. This is the first report on the identification
of mammalian KDN-glycoproteins by chemical and biochemical methods. 相似文献
918.
In normal and pathological tissues, polymorphonuclear leukocyte proteases (elastase, cathepsin G and proteinase 3) may generate soluble peptides through limited proteolysis of elastin, the main component of mature elastic fibres. Elastin-derived peptides display diverse biological activities including cell migration, differentiation, proliferation, chemotaxis, tumor progression and up-regulation of metalloproteinases. To be biologically active, their structures must adopt a beta-turn conformation which accommodates to the cell surface-located elastin binding protein. In this study, we established that human elastin exon 24-derived peptides are hydrolysed by leukocyte elastase, when the active site is fully occupied (from S(5) to S'(3)). As shown by mass spectrometry analyses, a major cleavage site was demonstrated at a Val-Ala bond and a minor one at Gly-Val bond. For longer peptides, the hydrolysed fragments could themselves be re-hydrolysed. If the shortest fragments do not contain the GxxPG sequence known to stimulate cellular effects, some of the intermediates together with hydrolysis fragments generated by other proteases such as proteinase 3, may possess this motif. 相似文献
919.
Periodontal ligament (PDL) cells exhibit several osteoblastic traits and are parathyroid hormone (PTH)-responsive providing evidence for a role of these cells in dental hard-tissue repair. To examine the hypothesis that PDL cells respond to PTH stimulation with changes in proliferation and apoptotic signaling through independent but convergent signaling pathways, PDL cells were cultured from human bicuspids obtained from six patients. PDL cells at different states of maturation were challenged with PTH(1–34) intermittently for 0, 1, or 24 h/cycle or exposed continuously. Specific inhibitors to protein kinases A and C (PKA, PKC) and the mitogen-activated protein kinase cascade (MAPK) were employed. At harvest, the cell number, BrdU incorporation, and DNA fragmentation were determined by means of cell counting and immunoassays. Intermittent PTH(1–34) caused a significant increase in cell number in confluent cells as opposed to a reduction in pre-confluent cells. In confluent cells, the effect resulted from a significant increase in proliferation, whereas DNA fragmentation was reduced when PTH(1–34) was administered for 1 h/cycle but increased after PTH(1–34) for 24 h/cycle. Inhibition of PKC inhibited PTH(1–34)-induced proliferation but enhanced apoptosis. Inhibition of PKA enhanced proliferation and DNA fragmentation. Similar results were obtained in less mature cells, although, in the presence of the PKA inhibitor, the PTH(1–34)-induced changes were more pronounced than in confluent cells. In the presence of the MAPK inhibitor, all of the parameters examined were reduced significantly in both maturation states. Thus, PTH(1–34) mediates proliferative and apoptotic signaling in human PDL cells in a maturation-state-dependent manner via PKC-dependent and PKA-dependent pathways.This research was supported by research grants from the BONFOR program (O-135.0006) of the University of Bonn, Bonn, Germany and the Deutsche Forschungsgemeinschaft (DFG; LO-1181/1-1). 相似文献
920.