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41.
d'Amati G Bagattin A Bauce B Rampazzo A Autore C Basso C King K Romeo MD Gallo P Thiene G Danieli GA Nava A 《Human pathology》2005,36(7):761-767
We report on a family with a history of sudden death and effort-induced polymorphic ventricular arrhythmias. The index case was a 17-year-old boy who died suddenly and at postmortem had evidence of fibrofatty replacement in the right ventricular free wall, consistent with arrhythmogenic right ventricular cardiomyopathy, as well as calcium phosphate deposits within the myocytes. A molecular genetics investigation carried out in the paraffin-embedded myocardium of the subject and in blood samples of family members disclosed a missense mutation in exon 3 (230C-->T; A77V) of the cardiac ryanodine receptor type 2 gene. The carriers showed effort-induced polymorphic ventricular tachycardia in the setting of normal resting electrocardiogram and trivial echocardiographic abnormalities, consistent with catecholaminergic polymorphic ventricular tachycardia. The observation of both arrhythmogenic right ventricular cardiomyopathy type 2 and catecholaminergic polymorphic ventricular tachycardia in the same family suggests that the two entities might correspond to different degrees of phenotypic expression of the same disease. This experience underscores the importance of a precise autopsy diagnosis in the case of sudden cardiac death, including molecular genetics, and the mission of pathologists to guide further clinical investigation of family members. 相似文献
42.
目的:以酪氨酸酶基因作为报告基因转染HEK293细胞, 利用其合成大量黑色素而能被MRI检测的特性来反映基因表达的情况, 以探索磁共振成像(MRI)评价体外细胞基因表达的方法。方法:以脂质体将含酪氨酸酶基因完全cDNA的pcDNA3tyr质粒转染到HEK293细胞, 以MRIT1WI、T1WI/SPIR、T2WI序列扫描转染细胞, 观察表达的黑色素的MRI信号。应用Fontana染色检测黑色素的合成, RT-PCR检测酪氨酸酶基因的cDNA片段, 以进一步验证酪氨酸酶基因的转染与表达。结果:(1)pcDNA3tyr质粒转染进入HEK293细胞并在其中表达生成黑色素, 转染5μg、10μg、20μg质粒的106个细胞内生成的黑色素能够被MRI检测到并在MRIT1WI、T1WI/SPIR、T2WI检查呈高信号, MRI信号强度与转染质粒量成正相关。(2)Fontana染色法检测到HEK293细胞内的黑色素颗粒;(3)采用RT-PCR方法检测到转染的HEK293细胞含酪氨酸酶基因的cDNA片段。结论:MRI能够检测到HEK293细胞内由外源基因表达合成的黑色素, 说明影像学与分子生物学技术结合可以评价体外细胞基因表达的情况。 相似文献
43.
Jan Schmeller Michael Wessolly Elena Mairinger Sabrina Borchert Thomas Hager Thomas Mairinger Kurt Werner Schmid Jeremias Wohlschlaeger Robert F.H. Walter Fabian D. Mairinger 《Pathology, research and practice》2019,215(2):381-386
Introduction
The usage of formalin-fixed paraffin embedded (FFPE) tissue is characterized by its long shelf-life and simple handling. Therefore it is the most commonly available tissue specimen in routine diagnostics and histological studies. Formaldehyde fixation may result in RNA degradation and cross linking with proteins, while storage conditions also affect RNA integrity. The present study was designed to investigate the influence of these factors on RNA analysis.Design
FFPE-derived RNA from sections of 23 patients with spontaneous pneumothoraxes was used. Unstained sections of FFPE tissue were stored at various temperatures (?80?°C, ?20?°C, 4?°C, 24?°C) prior to RNA extraction. The potential impact on RNA quality of semi-automatic and manual RNA isolation and three different deparaffinization agents (mineral oil, xylene and d-limonene) were compared.Results
The storage temperature of FFPE sections affects RNA concentration and fragmentation, with the optimal storage temperature below -20?°C. The RNA extracted with d-limonene shows equivalent quality to the RNA extracted using more toxic standard agents. The manual isolation provides a higher RNA yield compared to the semi-automatic isolation. However, no differences in the amount of longer RNA fragments were observed. Furthermore, the semi-automatic isolation showed an enhanced RNA quality.Conclusion
FFPE sections not directly used for RNA extraction should be stored below -20?°C to increase quality and yield of the RNA. Usage of semi-automatic isolation produces superior results and simplifies routine processes by having less hands-on-time. Replacement of toxic xylene by d-limonene may contribute to improved occupational safety while not influencing analytical results. 相似文献44.
Summary A phylogenetic tree has been constructed from comparisons of entire 16S rRNA gene sequences from different prokaryotes and from several algal plastids. According to this study, and to previous work on the ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) large and small subunit genes, we postulate that: (1) rhodophyte and chromophyte plastid genomes have a common, composite phylogenetic origin which implies at least two different ancestors, a cyanobacterial and a -proteobacterial ancestor; (2) chlorophyte (green algae and land plants) plastids have a cyanobacterial ancestor which probably differs from that of rhodophyte and chromophyte plastids, and in any case constitute a different lineage; (3) euglenophyte plastid genomes also seem to have a composite phylogenetic origin which involves two different lineages. 相似文献
45.
46.
J. Rappaport M. W. Richardson P. E. Klotman S. K. Arya G. Baier-Bitterlich 《Journal of molecular medicine (Berlin, Germany)》1995,73(12):583-589
HIV-1 and HIV-2 are co-endemic in certain geographic areas. HIV-2 is more weakly pathogenic than HIV-1, and progression to AIDS occurs less frequently and over a longer period of time. Recent epidemiologic studies suggest that individuals infected with HIV-2 have a lower risk of HIV-1 infection. Both immune mechanisms and various modes of viral interference have been proposed to account for these results. Our findings, described in this paper, suggest that HIV-2 inhibits HIV-1 replication. To study the molecular interactions between HIV-1 and HIV-2, proviral clones were transfected alone or in combination into the human T cell line CEM. LTR-CAT indicator constructs were included for the purpose of monitoring viral promoter activity. Viral replication in transfected cells was monitored by p24 antigen capture assay of cell culture supernatants and Western blot analysis of cell extracts. HIV-2 inhibited HIV-1 replication as determined by intracellular and extracellular p24 antigen levels. Similar results were obtained with simultaneous virus infection using HIV-1 and HIV-2, rather than transfections of proviral DNA. Using cotransfection of HIV-1 and HIV-2 LTR indicator gene constructs, the mechanism of inhibition was found to be suppression of the HIV-1 LTR by HIV-2. The inhibitory effect of HIV-2 is not due to Tat-2, but appears to discriminate between the HIV-1 and HIV-2 LTRs based on differences in the Tat activation response element, TAR. These results suggest both a molecular mechanism for HIV-2 interference with HIV-1 replication and a potential molecular approach to therapy. 相似文献
47.
Temperature-sensitive mutants of reovirus type 3 are capable of interfering with the replication of wild-type reovirus type 3. The interfering activity correlated with the ability of pairs of mutants to complement at 39°: Pairs of noninterfering mutants (tsD × tsE) yielded efficient complementation (indexes of 10–50); pairs of interfering mutants (including members of groups ts A, B, G) did not produce significant complementation (indexes ~ 1). The ability of pairs of mutants to reassort at 39° generally followed a similar pattern. Thus interference is an important property of ts mutants of reovirus and needs to be considered when genetic interactions are being studied at 39°. 相似文献
48.
Soluble and membrane-bound forms of brain acetylcholinesterase in Alzheimer''s disease 总被引:1,自引:0,他引:1
Kathleen M. Schegg Leslie S. Harrington Surl Neilsen Richard M. Zweig John H. Peacock 《Neurobiology of aging》1992,13(6):697-704
In order to determine the effect of Alzheimer's disease on the relative distribution of soluble and membrane-bound molecular forms of acetylcholinesterase (AChE) in the brain, postmortem samples (delay interval less than 12 h) were obtained from parietal cortex (Brodmann area 40) and hippocampus as well as the areas containing their respective projection nuclei, i.e., substantia innominata and septal nucleus, in 9 patients with Alzheimer's disease (AD) and 4 normal controls. The monomer (G1), dimer (G2), and tetramer (G4) forms of AChE were examined. In AD compared to controls, significant changes occurred in area 40 and hippocampus but not in the areas containing projection nuclei, and included loss of mean total AChE activity, decrease in the relative percentage of membrane-bound G4, and increase in the relative percentage of soluble G1---G2. Percent of soluble G4 was unaffected in AD brain. In area 40 but not hippocampus a large increase in percent membrane-bound G1-G2 occurred. Thus, these results emphasize that the selective decrease in membrane-bound G4 accounts for the decrease in total G4 activity in AD brain. 相似文献
49.
Horii A Smith PF Darlington CL 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2001,140(2):252-200
Spontaneous recovery from the oculomotor and postural symptoms of unilateral labyrinthectomy (UL) is known as vestibular
compensation, which is a useful model for investigation of the mechanisms of lesion-induced CNS plasticity. In the present
study, to elucidate the molecular biological basis of vestibular compensation, we investigated changes in the mRNA expression
of glutamate receptor subunit/subtypes in the rat central vestibular system, including the vestibular nucleus complex (VNC),
inferior olive (IO), and cerebellar flocculus following UL, using a real-time quantitative polymerase chain reaction (PCR)
method. In normal control animals, regional differences in the expression of several glutamate receptor subunit/subtypes,
e.g., NR1 and NR2A subunits of the N-methyl-D-aspartic acid (NMDA) receptor, GluR2 and KA2 subtypes of non-NMDA receptors, and mGluR1 and mGluR7 metabotropic glutamate
receptors, were consistent with previous results from studies using in situ hybridization histochemistry, suggesting that
the real-time quantitative PCR method was a reliable procedure for evaluation of changes in mRNA expression. In the vestibular
nucleus complex, NR2A, GluR2 and mGluR7 mRNA were ipsilaterally downregulated by 6 h following UL (P<0.05, P<0.05 and P<0.01, respectively). In the inferior olive, no changes in gene expression were observed. In the ipsilateral flocculus, KA2
mRNA expression was increased by 50 h post-UL (P<0.05). However, in the contralateral flocculus, mGluR1 mRNA was downregulated by 6 h post-UL (P<0.005). Both the increase in KA2 mRNA expression in the ipsilateral flocculus and the decrease in mGluR1 mRNA expression
in the contralateral flocculus may have had the effect of reducing Purkinje cell inhibition of ipsilateral VNC neurons, thereby
contributing to the rebalancing of spontaneous resting activity between the ipsilateral and contralateral VNCs. It is suggested
that such changes in the activities of the floccular-VNC pathways may be important to the vestibular compensation process.
Electronic Publication 相似文献
50.
Itoh K Naganawa Y Matsuzawa F Aikawa S Doi H Sasagasako N Yamada T Kira J Kobayashi T Pshezhetsky AV Sakuraba H 《Journal of human genetics》2002,47(1):29-37
Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S)
in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type
2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset
phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed
enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective
protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded
in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S
transversions cause large conformational changes including the active site residues responsible for binding the sialic acid
carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of
the constructed models, which was also influenced by previously identified V217M and G243R transversions.
Received: Stptember 21, 2001 / Accepted: November 2, 2001 相似文献