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41.
Human leukocyte antigen matching and fetal loss: results of a 10 year prospective study 总被引:6,自引:0,他引:6
Ober C; Hyslop T; Elias S; Weitkamp LR; Hauck WW 《Human reproduction (Oxford, England)》1998,13(1):33-38
The role that maternal and fetal human leukocyte antigen (HLA) genes play
in pregnancy is unknown, but it has been suggested that fetuses whose HLA
alleles do not differ from maternal alleles (i.e. histocompatible fetuses)
are more likely to be aborted than fetuses with HLA alleles that differ
from maternal alleles (i.e. histoincompatible fetuses). To elucidate the
role of HLA compatibility in pregnancy, we tested the hypothesis that
couples who match for HLA alleles or haplotypes would have reduced
fertility because only these couples could produce histocompatible fetuses.
We conducted a 10 year prospective study of HLA matching and pregnancy
outcome in 111 Hutterite couples, providing information on 251 pregnancies.
A logistic regression analysis was performed to determine the effects of
HLA matching at HLA regions and loci on pregnancy outcome (fetal loss
versus delivery). Significantly increased fetal loss rates were observed
among couples matching for the entire 16-locus haplotype (P = 0.002). Among
the individual loci, loss rates were increased among couples matching for
HLA-B (P = 0.019), HLA-C (P = 0.033) and the complement component, C4 (P =
0.043). We interpret these results as evidence that matching for the entire
16-locus haplotype and/or alleles at an HLA-B-linked locus confers
significant risk for fetal loss.
相似文献
42.
Andrew P. Evan Don A. Hay William G. Dail 《Anatomical record (Hoboken, N.J. : 2007)》1978,191(4):397-413
The present study utilizes the scanning electron microscope (SEM) to reveal the surface morphology of proximal tubular cells and the parietal cells of Bowman's capsule of the adult rabbit nephron. To facilitate the examination of the basal surface of these cells, proximal tubules were dissected free and treated with collagenase to remove the basememt membrane. Other blocks of tissue were cryofractured to expose the lateral cell surfaces of the proximal tubules. Our investigation has shown that the lateral and basal surfaces of both the convoluted and straight segments of the proximal tubule have numerous processes. However, the arrangement and degree of branching is distinctly different in the two segments. The convoluted segment has large lateral ridges which form at the base of the microvilli and fan out to divide into lateral-basal processes. Many of the lateral-basal processes reach the basement membrane intact, interdigitating with complementary processes from adjacent cells. However, some of the lateral-basal processes branch into short, knobby projections (basal villi) which may also reach the basement membrane. Patches of basal villi are interspersed between broad regions of interdigitating lateralbasal processes. Therefore, in the convoluted segment, the lateral-basal processes form the major part of the basal cell surface. In tubular cells of the pars recta, unlike convoluted tubular cells, the majority of the ridges remain unbranched and pass directly to the basal surface where they divide into elaborate basal villi. Thus the basal surface of the pars recta cells is highly complex, appearing leaf-like, being a composite of numerous basal villi with a few lateral ridges. The basal surface of some parietal cells of Bowman's capsule have parallel ridges, which results in patches of striations. 相似文献
43.
Andrea Verónica Pontoriero Elsa Graciela Baumeister Ana María Campos Vilma Lidia Savy Yi Pu Lin Alan Hay 《Journal of clinical virology》2003,28(2):130-140
BACKGROUND: The analysis of epidemic influenza virus has been focused on antigenic and genomic characterization of the hemagglutinin (HA) glycoprotein in order to detect new variants for the recommendation of the vaccine strains in each season. Since October 1998, WHO organized a second meeting to evaluate the vaccine formula for the southern hemisphere. OBJECTIVES: (a) Present the antigenic and genomic characterization of influenza strains obtained from the Argentina surveillance network, (b) compare between strains collected in Argentina and other countries with the vaccine formula strains used in each season. STUDY DESIGN: Influenza strains were collected during a 5-year period (1995-1999). Initially, laboratory diagnosis was done by immunofluorescence (IF) assay on clinical samples, followed by viral isolation in Madin-Darby canine kidney (MDCK) cells. The isolates were characterized antigenically by hemagglutination-inhibition (HI) assay with post-infection ferret antisera. The genomic characterization consisted on RT-PCR followed by sequencing of the HA1 portion of the HA gene. The comparison between reference and circulating strains was analyzed by the construction of phylogenetic trees. RESULTS: The H3N2 circulating strains matched the corresponding vaccine component only in 1999, the first year when a vaccine recommended specifically for the southern hemisphere was used. Besides, H1N1 circulating strains matched the corresponding vaccine component only in 1998. Regarding to influenza B, only in 1995, the circulating strains showed no match to the B vaccine component. CONCLUSIONS: The results showed the usefulness of an intensified influenza laboratory surveillance to access the correct vaccine and the importance of having the necessary tools to characterize the circulating strains. 相似文献
44.
Recurrent epidemics of influenza are due to the frequent emergence of antigenic variants. With co-circulation of two influenza A subtypes and two antigenically distinct lineages of B viruses, genetic reassortment also has an important role in antigenic drift, as illustrated by recent changes in both A and B viruses. The H1N2 subtype viruses, which emerged during 2001, possessed a H1 HA similar to those of contemporary A/New Caledonia/20/99 (H1N1)-like viruses and seven genes closely related to those of recent H3N2 viruses, and did not represent a significant increase in the antigenic diversity of circulating viruses. The re-emergence of B/Victoria/2/87-lineage viruses, previously prevalent during the 1980s, in 2000 has been followed by the predominant circulation of reassortant B viruses possessing a B/Victoria-lineage HA and a B/Yamagata-lineage NA similar in sequence to those of recent B/Sichuan/379/99-like viruses. These events emphasize not only the lack of divergence in the complementary functional characteristics of the HA and NA of divergent influenza B lineages, but also the apparent convergence in compatibility between the H1 and N2 components of the two influenza A subtypes. 相似文献
45.
Nucleotide sequence of the coat protein gene of a necrotic strain of potato virus Y from New Zealand 总被引:2,自引:0,他引:2
Summary The sequence of the 3-terminal 1,134 nucleotides of the genome of a New Zealand isolate of a necrotic strain of potato virus Y (PVYN) has been determined. This sequence contains one large open reading frame of 796 nucleotides, the start of which was not identified, which is capable of encoding a protein of 264 amino acid residues with a molecular weight of 29,631. Comparison of the amino acid sequence with a published coat protein sequence of another strain, PVY-D, and with the amino acid sequence deduced from PeMV cDNA sequence data, confirms that the 3 cistron encodes the viral coat protein in PVYN. Adjacent to the 3 end of the coding region there is an untranslatable sequence of 326 nucleotides terminating in a polyadenylate tract. An alignment of the PVYN amino acid sequence with the coat protein sequences of six other potyviruses revealed significant sequence similarities in the internal and carboxy terminal regions. Much amino acid sequence similarity was found between PVYN, PVY-D, and PeMV (91–93%), suggesting that PeMV should be regarded as a PVY strain. An analysis of the 3-untranslated region of the six potyviruses revealed PVYN and PeMV as the only viruses displaying sequence similarity in this region. The 3-untranslated sequences of PVYN and PeMV were further examined for secondary structure. 相似文献
46.
By developing an appropriate immunization protocol for SCID (hu-PBL-SCID) mice engrafted with human peripheral blood lymphocytes in combination with scFv phage display library, we were able to establish an efficient strategy to obtain human scFv clones against a human self-antigen, TNF-alpha. The mice pretreated with gamma-radiation (3Gy) and anti-asialo GM1 antibody were immunized with a mixture of human TNF-alpha-keyhole limpet hemocyanin and Freund's adjuvant. Human antibody maturation was suggested to be induced in the mice with the immunization protocol. The scFv clones obtained from the mice were shown to exhibit binding affinities in the range of 10(7)-10(8) M(-1). Together with our previously published work on the isolation of respiratory syncytial virus neutralizing scFvs, the results of this study have implicated that this combined approach is one of the effective alternatives for the cloning of human monoclonal antibodies specific for a wide range of antigens of interest. 相似文献
47.
Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of acanthamoebae from humans with keratitis and from sewage sludge 总被引:11,自引:0,他引:11
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Schroeder JM Booton GC Hay J Niszl IA Seal DV Markus MB Fuerst PA Byers TJ 《Journal of clinical microbiology》2001,39(5):1903-1911
This study identified subgenic PCR amplimers from 18S rDNA that were (i) highly specific for the genus Acanthamoeba, (ii) obtainable from all known genotypes, and (iii) useful for identification of individual genotypes. A 423- to 551-bp Acanthamoeba-specific amplimer ASA.S1 obtained with primers JDP1 and JDP2 was the most reliable for purposes i and ii. A variable region within this amplimer also identified genotype clusters, but purpose iii was best achieved with sequencing of the genotype-specific amplimer GTSA.B1. Because this amplimer could be obtained from any eukaryote, axenic Acanthamoeba cultures were required for its study. GTSA.B1, produced with primers CRN5 and 1137, extended between reference bp 1 and 1475. Genotypic identification relied on three segments: bp 178 to 355, 705 to 926, and 1175 to 1379. ASA.S1 was obtained from single amoeba, from cultures of all known 18S rDNA genotypes, and from corneal scrapings of Scottish patients with suspected Acanthamoeba keratitis (AK). The AK PCR findings were consistent with culture results for 11 of 15 culture-positive specimens and detected Acanthamoeba in one of nine culture-negative specimens. ASA.S1 sequences were examined for 6 of the 11 culture-positive isolates and were most closely associated with genotypic cluster T3-T4-T11. A similar distance analysis using GTSA.B1 sequences identified nine South African AK-associated isolates as genotype T4 and three isolates from sewage sludge as genotype T5. Our results demonstrate the usefulness of 18S ribosomal DNA PCR amplimers ASA.S1 and GTSA.B1 for Acanthamoeba-specific detection and reliable genotyping, respectively, and provide further evidence that T4 is the predominant genotype in AK. 相似文献
48.
49.
Characterization of virus-specific messenger RNAs from avian fibroblasts infected with fowl plague virus 总被引:8,自引:0,他引:8
In cell-free protein synthesizing systems from wheat embryos, messenger RNAs extracted from chick embryo fibroblasts infected with fowl plague virus direct the synthesis of nine virus-specific polypeptides, two of which may be related to the virus-specific glycopolypeptides. All of the mRNAs are complementary in sequence to virion RNA, and RNAs which do not contain poly A appear to be translated as efficiently as their polyadenylated counterparts. Under certain conditions of incubation, virion RNA also directs the synthesis of discrete polypeptides but these products are not detected in infected cells. 相似文献
50.
Emergence of influenza A H1N2 reassortant viruses in the human population during 2001 总被引:8,自引:0,他引:8
Gregory V Bennett M Orkhan MH Al Hajjar S Varsano N Mendelson E Zambon M Ellis J Hay A Lin YP 《Virology》2002,297(1):1-7
A recombinant vaccinia virus encoding rotavirus protein NSP3 driven by an internal ribosome entry site (IRES) from the encephalomyocarditis (EMC) virus was able to abate protein synthesis in BSC1 cells by 25-fold, with as much as 30% of the remaining protein synthesis being NSP3. Hence NSP3 shuts off host cell protein synthesis down to the level seen during rotavirus infection but is unable to prevent translation from EMC IRES-driven genes. This effect was abolished by deletions in the eIF4G-binding (aa 274-313) and the dimerization (aa 150-206) but not the viral mRNA-binding (aa 83-149) domains, supporting that NSP3 functions in vivo as a dimer. Binding of eIF4G by NSP3 has been implicated in interfering with mRNA 5'-3' circularization, hence such circularization is essential for translation in mammalian cells. 相似文献