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981.
Zhou JJ Fu J Fang DY Yan HJ Tian J Zhou JM Tao JP Liang Y Jiang LF 《Archives of virology》2007,152(8):1515-1521
Summary In March 2006, a human H5N1-infected case was found in Guangdong province, China. Here, we molecularly characterized the hemagglutinin
(HA) and neuraminidase (NA) genes of the A/China/GD01/06 (GD01) strain causing the infection. The phylogenetic analyses suggested
that the HA and NA genes of GD01 and recent human H5N1 viruses from different provinces of China were probably derived from
a common ancestor and the H5N1 human infection was acquired directly from affected poultry. At the cleavage site of HA, GD01
contained multiple basic amino acids, a feature characteristic of highly pathogenic avian influenza A viruses. The virus possessed
Gln222, Gly224, Ser223, Asn182, Gln192 residues adjacent to the receptor-binding site, preferential for recognizing SAα2,
3Gal. In addition, the GD01 NA amino acid sequence possessed Asn344 and Phe466, which might be related to the low-pH stability
of the sialidase activity and gastrointestinal symptoms of the patient. 相似文献
982.
Summary Tobacco vein banding mosaic virus (TVBMV) is of increasing importance in tobacco production on the Chinese mainland. The 3′-terminal
genomic sequences (1624 nucleotides) of 12 TVBMV isolates from China were determined and compared to the sequences of only
four TVBMV isolates available in databanks. The results revealed that TVBMV consists of several phylogenetically distinguishable
strains that show a degree of correlation with the geographical origin. Two isolates from Yunnan had a unique putative NIb/CP
proteolytic cleavage site of Q/N that is uncommon for potyviruses, whereas other TVBMV isolates had the more typical Q/G amino
acids at that site. One isolate (ZB6) from Zibo, Shandong Province, was predicted to have experienced recombination within
the characterized genomic region.
First two authors contributed equally. 相似文献
983.
The diverse immunostimulatory effects of CpG oligodeoxynucleotides (CpG ODN) have been demonstrated extensively in mice and human. Although the immunoadjuvant effects of CpG ODN in pigs were also studied in several reports, until now, little work has been carried out with regard to their effects on the adaptive immune system of newly weaned piglets. In this study, swine streptococcic septicemia killed vaccine (SSSK vaccine) was used as antigen, we assessed the in vivo immunostimulatory effects of different CpG motifs in newly weaned piglets. The proportion of CD4(+), CD8(+) T lymphocytes subpopulations and proliferation of peripheral blood mononuclear cells (PBMCs), IFN-gamma and IL-6 in serum, and the titre of IgG and IgG2/IgG1 isotype to SSSK vaccine in serum were tested at different time-points. The results suggested that, the CD4(+)/CD8(+) ratio decreased significantly in weaned piglets inoculated with phosphate buffer saline (PBS) alone, however, it was stable in CpG ODN-coinoculated newly weaned piglets. IFN-gamma and IL-6 levels, the titres of specific antibodies IgG, IgG2 and proliferative responses of CpG ODN-coinjected piglets were all significantly higher than those of SSSK vaccine alone or PBS or GpC ODN-coinjected piglets. The porcine-specific ODN-induced responses were stronger in animals injected with human-specific or mouse-specific CpG ODN. These in vivo data demonstrate for the first time that CpG ODN can stimulate adaptive immune system in weaned piglets. 相似文献
984.
985.
CAMP factor is an extracellular cytolytic protein produced by Streptococcus agalactiae. CAMP factor has been reported to bind the Fc fragments of immunoglobulin G (IgG) and has therefore also been called protein
B, in analogy to protein A of Staphylococcus aureus. We attempted to characterize the interaction of protein B with IgG in more detail. In contrast to protein A, CAMP factor
does not inhibit the activation of complement by hemolysin antibodies bound to sheep red cell surfaces. IgG also failed to
inhibit the co-hemolytic activity of CAMP factor, which is in disagreement with previous findings. After co-incubation, CAMP
factor and IgG were cleanly separated by gel filtration, indicating that no binding had occurred.
Waseem El-Huneidi and Ryan Mui contributed equally to this work. 相似文献
986.
To engineer bio-macromolecular systems, protein–substrate interactions and their configurations need to be understood, harnessed,
and utilized. Due to the inherent large numbers of combinatorial configurations and conformational complexity, methods that
rely on heuristics or stochastics, such as practical computational filtering (CF) or biological focusing (BF) criterions,
when used alone rarely yield insights into these complexes or successes in (re)designing them. Here we use a coupled CF–BF
criterion upon an amenable interfacial pocket (IP) of a protein scaffold complexed with its substrate to undergo residue replacement
and R-group refinement (R4) to filter out energetically unfavorable residues and R-group conformations, and focus in on those that are evolutionarily
favorable. We show that this coupled filtering and focusing can efficiently provide a putative engineered IP candidate and
validate it computationally and empirically. The CF–BF criterion may permit holistic understanding of the nuances of existing
protein IPs and their scaffolds and facilitate bioengineering efforts to alter substrate specificity. Such approach may contribute
to accelerated elucidation of engineering principles of bio-macromolecular systems.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
987.
The in vivo immunoadjuvant effects of CpG oligodeoxynucleotides (CpG ODN) have been studied extensively in mice and relatively fewer studies have been done in other species. But so far, the innate immunostimulatory effects of CpG ODN have been demonstrated just in mouse, monkey, sheep and chicken in some reports. The purpose of this study is to determine the potential effects of CpG ODN in newborn piglets. The proportion of CD4(+), CD8(+) T lymphocytes subpopulations and the major histocompability complex (MHC-II) antigen expression of peripheral blood mononuclear cells (PBMCs) and IFN-gamma in serum were tested at various time-points. The results suggested that, the CD4(+)/CD8(+) ratio decreased over time in piglets inoculated with phosphate buffer saline (PBS) alone, however, it was stable in CpG ODN-inoculated piglets; the use of CpG ODN can prevent effectively the reduction of the proportion of CD4(+) T lymphocytes. The MHC-II antigen expression and IFN-gamma level of CpG ODN-injected piglets were significantly higher than those of PBS-injected piglets. The ODN-induced responses were stronger in animals injected with CpG ODN formulated in 30% emulsigen than in PBS. The innate immunostimulatory activity of CpG ODN appeared to be in dose-dependent manner. These in vivo data demonstrate for the first time that CpG ODN can stimulate innate immune system in newborn piglets. 相似文献
988.
Wang C Zhang D Li G Liu J Tian J Fu F Liu K 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,177(4):533-539
The present study was conducted to investigate whether safflor yellow B (SYB) had a protective effect on cerebral ischemic
injury and to determine the possible mechanisms in vivo and in vitro. In vivo, Male Wistar–Kyoto (WKY) rats were used to make
the model of middle cerebral artery occlusion (MCAO). The behavioral test was used to measure neurological deficit scores
for evaluation of the ischemic damage of brain. The infarction area of brain was assessed in brain slices stained with 2%
solution of 2,3,5-triphenyl tetrazolium chloride (TTC). Spectrophotometric assay was used to determine the activities of superoxide
dismutase (SOD) and glutathione peroxidase (GPx), contents of malondialdehyde (MDA) and adenosine triphosphate (ATP) of the
brain. Furthermore, the respiratory control ratio (RCR = state 3/state 4) was assessed in the brain mitochondria. In vitro,
the effect of SYB was tested in cultured fetal cortical cells exposed to glutamate to identify its neuroprotection against
neurons damage. The results in vivo showed that SYB at doses of 3.0 and 6.0 mg kg−1 markedly decreased the neurological deficit scores and the infarction area in MCAO rats. At the same time, SYB significantly
improved mitochondrial energy metabolism, decreased MDA content, and increased SOD and GPx activities in ischemic brain. The
results in vitro showed that SYB remarkably inhibited neuron damage induced by glutamate in cultured fetal cortical cells.
These suggest that SYB might act as a potential neuroprotective agent against the cerebral ischemia-induced injury in rat
brain through reducing lipid peroxides, scavenging free radicals, and improving the energy metabolism. 相似文献
989.
Tian JR Ishiyama A Demer JL 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,178(4):529-541
Dynamic changes of deficits in canal and otolith vestibulo-ocular reflexes (VORs) to high acceleration, eccentric yaw rotations
were investigated in five subjects aged 25–65 years before and at frequent intervals 3–451 days following unilateral vestibular
deafferentation (UVD) due to labyrinthectomy or vestibular neurectomy. Eye and head movements were recorded using magnetic
search coils during transients of directionally random, whole-body rotation in darkness at peak acceleration 2,800°/s2. Canal VORs were characterized during rotation about a mid-otolith axis, viewing a target 500 cm distant until rotation onset
in darkness. Otolith VOR responses were characterized by the increase in VOR gain during identical rotation about an axis
13 cm posterior to the otoliths, initially viewing a target 15 cm distant. Pre-UVD canal gain was directionally symmetrical,
averaging 0.87 ± 0.02 (±SEM). Contralesional canal gain declined from pre-UVD by an average of 22% in the first 3–5 days post-UVD,
before recovering to an asymptote of close 90% of pre-UVD level at 1–3 months. This recovery corresponded to resolution of
spontaneous nystagmus. Ipsilesional gain declined to 59%, and showed no consistent recovery afterwards. Pre-UVD otolith gain
was directionally symmetrical, averaging 0.56 ± 0.02. Immediately after UVD, the contralesional otolith gain declined to 0.30 ± 0.02,
and did not recover. Ipsilesional otolith gain declined profoundly to 0.08 ± 0.03 (P < 0.01), and never recovered. In contrast to the modest and directionally symmetrical effect of UVD on the human otolith
VOR during pure translational acceleration, otolith gain during eccentric yaw rotation exhibited a profound and lasting deficit
that might be diagnostically useful in lateralizing otolith pathology. Most recovery of the human canal gain to high acceleration
transients following UVD is for contralesional head rotation, occurring within 3 months as spontaneous nystagmus resolves.
Grant support: United States Public Health Service grants DC-02952 and AG-09693. JLD is Leonard Apt Professor of Ophthalmology. 相似文献
990.