全文获取类型
收费全文 | 10051篇 |
免费 | 776篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 157篇 |
儿科学 | 275篇 |
妇产科学 | 148篇 |
基础医学 | 1775篇 |
口腔科学 | 85篇 |
临床医学 | 1061篇 |
内科学 | 2178篇 |
皮肤病学 | 163篇 |
神经病学 | 950篇 |
特种医学 | 387篇 |
外国民族医学 | 1篇 |
外科学 | 1532篇 |
综合类 | 100篇 |
一般理论 | 1篇 |
预防医学 | 744篇 |
眼科学 | 144篇 |
药学 | 596篇 |
中国医学 | 17篇 |
肿瘤学 | 561篇 |
出版年
2022年 | 76篇 |
2021年 | 123篇 |
2020年 | 99篇 |
2019年 | 190篇 |
2018年 | 197篇 |
2017年 | 141篇 |
2016年 | 159篇 |
2015年 | 199篇 |
2014年 | 248篇 |
2013年 | 401篇 |
2012年 | 528篇 |
2011年 | 609篇 |
2010年 | 377篇 |
2009年 | 336篇 |
2008年 | 575篇 |
2007年 | 578篇 |
2006年 | 568篇 |
2005年 | 666篇 |
2004年 | 648篇 |
2003年 | 750篇 |
2002年 | 718篇 |
2001年 | 120篇 |
2000年 | 112篇 |
1999年 | 133篇 |
1998年 | 180篇 |
1997年 | 158篇 |
1996年 | 110篇 |
1995年 | 102篇 |
1994年 | 112篇 |
1993年 | 77篇 |
1992年 | 103篇 |
1991年 | 92篇 |
1990年 | 89篇 |
1989年 | 80篇 |
1988年 | 80篇 |
1987年 | 73篇 |
1986年 | 72篇 |
1985年 | 69篇 |
1984年 | 70篇 |
1983年 | 63篇 |
1982年 | 69篇 |
1981年 | 70篇 |
1980年 | 64篇 |
1979年 | 38篇 |
1978年 | 44篇 |
1977年 | 44篇 |
1976年 | 43篇 |
1975年 | 34篇 |
1974年 | 49篇 |
1972年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Thierry Janssen MD Michel Petein MD Roland van Velthoven MD Patrick van Leer MD Marc Fourmarier MD Juan-Pablo Vanegas MD Andre Danguy PhD Claude Schulman MD Jean-Lambert Pasteels MD Robert Kiss PhD 《Human pathology》1996,27(12):1341-1347
The histochemical binding pattern of the peanut (Arachis hypogaea) lectin (PNA) was quantitatively described by means of computer-assisted microscope analysis in 28 benign prostatic hyperplasias (BPH), 15 prostatic intraepithelial neoplasias (PIN), and 119 prostatic adenocarcinomas. PNA exhibits noninunune but selective binding to glycoproteins with β-D-galactosyl(1,3)-N-acetyl-D-galactosamine residues. We also investigated whether a relationship existed between the number of histochemical-related PNA acceptors and the histochemical prostate-specific antigen (PSA) stain intensity, and between the number of PNA receptors and DNA ploidy level. The results show that neoplastic prostate tissues and high-grade intraepithelial prostatic neoplasias (PIN2_3) exhibit a significantly higher number of PNA acceptors than benign prostatic hyperplasias and low (PIN1) grade prostatic intraepithelial neoplasias. A statistically significant correlation was observed between the number of histochemically related PNA acceptors and PSA immunostain intensity. Lastly, diploid prostatic tumors, whether benign or malignant, exhibited a significantly higher number of PNA acceptors than aneuploid ones. These results suggest that PNA acceptors play an important role in the biology of prostate tumors. 相似文献
102.
103.
Karine Petitprez Jean-Marie Grzych Christine Pierrot Claude Godin André Capron Jamal Khalife 《Parasitology research》1997,84(1):38-40
Genes encoding the heavy and light chains of an anti-idiotype antibody (AB2) mimicking a protective oligosaccharide of Schistosoma mansoni were cloned and expressed as a single-chain Fv fragment. The expression in a functional state was tested using the AB1. A
specific binding between sFv and AB1 was observed. Immunization with the recombinant AB2 indicates its capacity to elicit
anti-S. mansoni antibodies.
Received: 28 April 1997 / Accepted: 24 June 1997 相似文献
104.
Clinical Features of Fatal Familial Insomnia: Phenotypic Variability in Relation to a Polymorphism at Codon 129 of the Prion Protein Gene 总被引:2,自引:0,他引:2
Pasquale Montagna Pietro Cortelli Patrizia Avoni Paolo Tinuper Giuseppe Plazzi Roberto Gallassi Francesco Portaluppi Jean Julien Claude Vital Marie Bernadette Delisle Pierluigi Gambetti Elio Lugaresi . 《Brain pathology (Zurich, Switzerland)》1998,8(3):515-520
Fatal Familial Insomnia is a hereditary prion disease characterized by a mutation at codon 178 of the prion protein gene cosegregating with the methionine polymorphism at codon 129 of the mutated allele. It is characterized by disturbances of the wake-sleep cycle, dysautonomia and somatomotor manifestations (myoclonus, ataxia, dysarthria, spasticity). PET studies disclose severe thalamic and additionally cortical hypometabolism. Neuropathology shows marked neuronal loss and gliosis in the thalamus, especially the medio-dorsal and anterior-ventral nuclei, olivary hypertrophy and some spongiosis of the cerebral cortex. Detailed analysis of 14 cases from 5 unrelated families showed that patients ran either a short (9.1+ 1.1 months) or a prolonged (30.8 + 21.3 months) clinical course according to whether they were homozygote met/met or heterozygote met/val at codon 129. Moreover, homozygotes had more prominent oneiric episodes, insomnia and dysautonomia at onset, whereas heterozygotes showed ataxia and dysarthria at onset, earlier sphincter loss and epileptic Grand Mai seizures; they also displayed more extensive cortical involvement on PET and at postmortem examination. Our data suggest that the phenotype expression of Fatal Familial Insomnia is related, at least partly, to the polymorphism at codon 129 of the prion protein-gene. 相似文献
105.
Summary Southern blot analysis of AvaI-digested total cellular DNA from the interfertile species Chlamydomonas eugametos and Chlamydomonas moewusii with a coxI mitochondrial gene probe from Chlamydomonas reinhardtii revealed single hybridizing fragments of 5.0 and 3.5 kb, respectively. The transmission of these mitochondrial DNA physical markers along with that of chloroplast genetic markers for resistance to streptomycin and resistance to erythromycin was studied in the fourth backcrosses of F1 hybrids to one or the other parent. Viability in these backcrosses is high in contrast to the cross C. eugametos x C. moewusii and its reciprocal which are associated with considerable meiotic product lethality. The resulting zygospores were found to transmit the mitochondrial and chloroplast genome markers uniparentally or preferentially from the mating-type-plus parent. Thus the species pair C. eugametos and C. moewusii differs from the pair Chlamydomonas reinhardtii and Chlamydomonas smithii in which mitochondrial genome markers are transmitted uniparentally by the mating-type minus parent, while the chloroplast genome markers are transmitted uniparentally by the opposite parental mating-type (Boynton et al. 1987). 相似文献
106.
107.
Elimination of B-lineage leukemia and lymphoma cells from bone marrow grafts using anti-B4-blocked-ricin immunotoxin 总被引:2,自引:0,他引:2
Denis C. Roy Claude Perreault Robert Bélanger Martin Gyger Christiane Le Houillier Walter A. Blättler John M. Lambert Jerome Ritz 《Journal of clinical immunology》1995,15(1):51-57
Bone marrow is the primary site of disease in patients with acute lymphoblastic leukemia (ALL) and is frequently involved in patients with non-Hodgkin's lymphoma (NHL). At the time of autologous bone marrow transplantation, marrow grafts from patients with leukemia and lymphoma are often still contaminated by malignant cells, even when such patients achieve complete clinical remission. In this study, we evaluated the potential of anti-B4-blocked-ricin (anti-B4-bR) immunotoxin to eliminate residual ALL and NHL cells from bone marrow. Anti-B4-bR binds to the CD19 antigen, which is B-lineage specific, and, at concentrations of 5×10–9
M or greater, could eliminate more than 3 logs of CD19+ Nalm-6 or Namalwa cells in a 20-fold excess of normal irradiated bone marrow after only 5 hr of incubation. This activity was abrogated by the addition of anti-B4 but not by the presence of galactose, which is the natural ligand for native ricin. Also, when used at these high concentrations, anti-B4-bR showed little nonspecific toxicity against normal hematopoietic progenitors. In conclusion, a single short exposure to anti-B4-bR is capable of inducing high levels of depletion of CD19+ leukemia and lymphoma cells without significant nonspecific toxicity against normal marrow progenitors. Therefore, anti-B4-bR offers an interesting approach to the elimination of B-lineage malignant cells prior to autologous bone marrow transplantation. 相似文献
108.
Berlier W Bourlet T Lawrence P Hamzeh H Lambert C Genin C Verrier B Dieu-Nosjean MC Pozzetto B Delézay O 《Journal of medical virology》2005,77(4):465-474
X4 and R5 HIV strains are present in the semen of men infected with HIV but R5 isolates are transmitted preferentially. The role of human epithelial cells in this selection is addressed. Three human cervical cell lines-CaSki, SiHa, and HEC1A-and normal human vaginal cells from HIV-negative donors were characterized for HIV receptor expression and incubated with X4 and R5 laboratory-adapted strains or primary isolates. The infection was assessed by detection of intracellular HIV DNA. The three cell lines were shown to express on their surface the CXCR4 and GalCer molecules, but not the CD4 and CCR5 ones. The three cell lines and normal human vaginal cells were found to be selectively permissive to X4 HIV entry; the preincubation of the cell lines with rhSDF-1 inhibited this infection. The detection of the intracellular proviral DNA in the cell lines and in normal human vaginal cells demonstrated a selective integration of X4 strains. Additional experiments showed that no extracellular RNA was detected in the supernatants of HEC1A cells infected by X4 isolates either after 18 days of culture or after incubation with PHA-stimulated PBMCs and that no transmission occurred after co-culture between infected HEC1A cells and PHA-stimulated PBMCs. These results suggest specific sequestration of X4 strains by genital epithelial cells, which could explain, at least in part, the HIV tropism selection process during sexual intercourse. 相似文献
109.
Zahariev A Bergouignan A Caloin M Normand S Gauquelin-Koch G Gharib C Blanc S 《European journal of applied physiology》2005,95(4):344-350
Because body composition is altered during head-down bed rest (HDBR), body mass can not be used as an index of energy balance.
Consequently diet allowances should not be based on body mass evolution but on fat mass changes. Though criticized, skinfold
thickness (ST) is the costless, easiest and fastest method to use for such an objective. The aim of this study was to compare
the percentage of body fat (%BF) estimated by ST with the isotope dilution of H218O. We compiled data from three HDBR campaigns, one on women (n=8) in November 1998 and two on the same men (n=8) in December 1997 (without countermeasure) and January 1998 (with thigh-cuffs countermeasure), according to a crossover
design. Body composition was assessed before and after 6 days of HDBR. %BF was derived from the biceps, triceps, sub-scapular
and sup-iliac ST according to Durnin and Wormersly (1974). Fat-free mass was measured on the same day by H218O dilution and fat mass was calculated by the difference with body mass and expressed as a percentage. Based on precision
tests, the minimum measurable change by ST was 1.1%BF for single measurement point. Both intercepts (F
4,30=0.89, P=0.45) and slopes (F
4,30=0.74; P=0.57) of the ST versus dilution relationships were not affected by the periods (December vs January), experimental conditions
(control vs HDBR vs HDBR + thigh cuffs) or sex allowing the derivation of a common relationship %BFst=0.94 × %BFdil (F
1,47=97.9, P<0.0001; non-significant intercept excluded) with a bias between methods of −1.7±2.0 %BF (95% CI: −5.8, 2.4 %BF). ST can be
used to measure %BF during HDBR provided great care is placed on training and changes are higher than 1.1 %BF. If the method
can be applied for in-flight energy balance monitoring given the high observed energy deficit, a tight monitoring of the individual
nutritional status as needed during simulation appears, however, dubious based on this solely method. 相似文献
110.
Martinez X Regner M Kovarik J Zarei S Hauser C Lambert PH Leclerc C Siegrist CA 《Virology》2003,305(2):428-435
The relative immaturity of the neonatal immune system limits CD4(+) Th1 and cytotoxic T lymphocyte (CTL) responses, and represents a significant challenge for the development of vaccines against intracellular pathogens. In this report, we demonstrate the ability of a non-replicative delivery system based on parvovirus-like particles (VLP) to induce CTL responses in the neonatal period. A single immunization of 1-week-old BALB/c mice with recombinant VLP carrying a CD8(+) T cell determinant from lymphocytic choriomeningitis virus (VLP-LCMV) induced antigen-specific CD8(+) cytotoxic T cells that were similar to those elicited by adult immunization, as assessed by cytotoxic activity, interferon (IFN)-gamma secretion, cytotoxic precursor cell frequencies, in vitro avidity for antigen and protective activity against viral challenge. These CTL responses are elicited within 2 weeks of a single immunization, in the absence of adjuvant and independently of the presence and help of CD4(+) T cells, highlighting the potential of VLP as candidate vaccine vectors in early life. 相似文献