全文获取类型
收费全文 | 9215篇 |
免费 | 532篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 263篇 |
妇产科学 | 220篇 |
基础医学 | 1396篇 |
口腔科学 | 281篇 |
临床医学 | 961篇 |
内科学 | 2011篇 |
皮肤病学 | 171篇 |
神经病学 | 1033篇 |
特种医学 | 194篇 |
外科学 | 669篇 |
综合类 | 38篇 |
一般理论 | 3篇 |
预防医学 | 795篇 |
眼科学 | 150篇 |
药学 | 672篇 |
中国医学 | 13篇 |
肿瘤学 | 874篇 |
出版年
2024年 | 13篇 |
2023年 | 93篇 |
2022年 | 214篇 |
2021年 | 318篇 |
2020年 | 210篇 |
2019年 | 226篇 |
2018年 | 266篇 |
2017年 | 210篇 |
2016年 | 259篇 |
2015年 | 293篇 |
2014年 | 408篇 |
2013年 | 531篇 |
2012年 | 712篇 |
2011年 | 735篇 |
2010年 | 379篇 |
2009年 | 340篇 |
2008年 | 608篇 |
2007年 | 662篇 |
2006年 | 610篇 |
2005年 | 526篇 |
2004年 | 508篇 |
2003年 | 460篇 |
2002年 | 457篇 |
2001年 | 39篇 |
2000年 | 27篇 |
1999年 | 53篇 |
1998年 | 75篇 |
1997年 | 77篇 |
1996年 | 44篇 |
1995年 | 54篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 21篇 |
1991年 | 23篇 |
1990年 | 16篇 |
1989年 | 28篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 24篇 |
1983年 | 26篇 |
1982年 | 19篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1973年 | 6篇 |
排序方式: 共有9805条查询结果,搜索用时 0 毫秒
31.
Ilaria Ferrarotti Michele Zorzetto Roberta Scabini Paola Mazzola Ilaria Campo Maurizio Luisetti 《Diagnostic molecular pathology》2004,13(3):160-163
There is worldwide growing awareness of alpha 1-antitrypsin deficiency (AATD), a major hereditary disorder in Caucasians. The gold standard for laboratory diagnosis of AATD is thin-layer isoelectrofocusing (IEF), which is labor intensive and should be performed in reference laboratories. The aim of this study was to find an easy, fast, and cheap method for detecting alpha1-antitrypsin S and Z variants, the most frequent variants associated with AATD. The novel method herein described is based on SexAI/Hpy99I RFLP. We studied samples from 90 subjects enrolled in the Italian National Registry for AATD, previously typed by isoelectrofocusing. We found a complete agreement among our results, IEF, and genotypes obtained by standard methods. We concluded that this novel method combines efficiency, ease, swiftness, and low cost. 相似文献
32.
33.
Robert H. Gray Marcia Sokol Roberta K. Brabec Michael J. Brabec 《Experimental and molecular pathology》1981,34(1):72-86
Studies have been undertaken to investigate the role of cellular autophagy in the accommodation of stress in a biological system. Chloroquine (Aralen hydrochloride), an antimalarial and anti-inflammatory drug, was used to induce autophagy in rat liver. A method is presented which uses differential and discontinuous sucrose gradient centrifugation for the preparation of autophagic vacuole-enriched fractions from rat liver. Ultrastructural studies of the autophagic vacuole fractions showed that the integrity of the autophagic vacuoles was maintained throughout the isolation procedure and that they were morphologically similar to those seen in situ. Assay of glucose-6-phosphatase, NADPH-DCIP reductase, and acid phosphatase confirm the presence of membranes derived from the endoplasmic reticulum, as well as lysosomes, in the autophagic vacuole fractions. The distribution of [14C]-chloroquine suggested a preferential binding of the drug to the autophagic vacuoles may have occurred. These results suggest that cellular autophagy may play an important role in the accommodation of chemically induced alterations in hepatocytes by preferentially sequestering chloroquine, as well as restoring cellular ultrastructure. 相似文献
34.
Dettin M Conconi MT Gambaretto R Pasquato A Folin M Di Bello C Parnigotto PP 《Journal of biomedical materials research》2002,60(3):466-471
Next generation dental/orthopedic biomaterials must be designed to enhance and support osteoblast adhesion. The osteoblasts use different ways to adhere, that is, integrin- and proteoglycan-mediated mechanisms. The present study reports on the synthesis and osteoblast-adhesive properties of peptides carrying RGD motifs and of sequences mapped on human vitronectin. Our data suggest that osteoblast adhesion on polystyrene plates modified with a linear peptide, in which the GRGDSP sequence is repeated four times, was significantly higher when compared to the adhesion obtained using branched peptides, interestingly containing the same motif. Osteoblast adhesion assays on acellular bone matrix using this active peptide gave very promising results. We also demonstrated that a novel peptide, carrying the X-B-B-B-X-B-B-X motif (where B is a basic amino acid and X is a nonbasic residue), promotes proteoglycan-mediated osteoblast adhesion more efficiently with respect to the KRSR sequence that was recently proposed as heparan-sulfate binding peptide. 相似文献
35.
Zauli D Contestabile S Grassi A Bortolotti R Ballardini G Bianchi FB 《The Journal of allergy and clinical immunology》2002,110(3):538-9; author reply 539
36.
Genetic instability in superficial bladder cancer and adjacent mucosa: an interphase cytogenetic study 总被引:5,自引:0,他引:5
Cianciulli AM Leonardo C Guadagni F Marzano R Iori F De Nunzio C Franco G Merola R Laurenti C 《Human pathology》2003,34(3):214-221
A systematic analysis of both tumors and the surrounding urothelium to help identify what lies behind the mechanism of multifocal tumor development has not yet been performed. In this study we investigated chromosome 1, 7, 9, and 17 aneusomy in 25 superficial papillary carcinomas and in 51 tissue samples taken from sites of macroscopically uninvolved urothelium surrounding the tumors, using the fluorescence in situ hybridization method. Our data demonstrated a close genetic relationship between all examined tumors and normal-appearing mucosa. Numeric aberrations of chromosomes 1, 7, 9, and 17 were found to exhibit similar patterns in all analyzed specimens, although with different frequencies. 相似文献
37.
Brunetti-Pierri N Andreucci MV Tuzzi R Vega GR Gray G McKeown C Ballabio A Andria G Meroni G Parenti G 《American journal of medical genetics. Part A》2003,(2):164-168
Partial trisomy of the long arm of chromosome 10 is a well-defined but rare syndrome. Clinical features of this chromosomopathy are a distinctive dysmorphic appearance, developmental delay, growth retardation, and in some cases, abnormalities of the extremities and renal, cardiac and ocular anomalies. This report describes a neonate with symmetric growth retardation and multiple dysmorphic features, in whom chromosomal analysis revealed a partial trisomy of chromosome 10q with a monosomy of the 13q34 region. The phenotype shares many common features with previously published cases. In addition to the typical features, our case also shows renal hypoplasia with early renal insufficiency and some genital anomalies. 相似文献
38.
Leal Filho MB Morandin RC de Almeida AR Cambiucci EC Borges G Gontijo JA Metze K 《Neuroscience letters》2005,373(2):165-170
There are reports describing both provocation and inhibition of neurogenic pulmonary edema by anesthetic drugs. Therefore, we compared the effect of two types of anesthesia on the formation of neurogenic pulmonary edema in rats with balloon-induced acute spinal cord injury. Animals with sham procedure (group 1) were anesthesized by intraperitoneal sodium pentobarbital. In the experimental groups, rats were submitted to acute spinal cord lesion by insufflations of a balloon in the epidural space at T8 for 1 min (group 3 under i.p. sodium pentobarbital and group 2 under i.p. xylazine-ketamine anesthesia). In rats with pentobarbital anesthesia, systolic blood pressure doubled the baseline value during compression, whereas this effect was less pronounced in the ketamine-xylazine group. The pulmonary index (100 x wet lung weight/body weight) was 0.395 (+/-0.018) in sham-operated rats, rose to 0.499 (+/-0.060) in group 2, and was maximum under pentobarbital anesthesia (0.639+/-0.14; p=0.0018). Histologic examination of the spinal cord showed parenchymal ruptures and acute hemorrhage. Comparison of the pulmonary index with histologic slides of lung parenchyma revealed that relevant intra-alveolar edema occurred only for index values above 0.55. On electron microscopy, endothelial alterations, and damage of the alveolar lining cells were found. Our study indicates that neurogenic pulmonary edema caused by spinal cord injury is less pronounced in rats under xylazine-ketamine anesthesia, when compared with pentobarbital. 相似文献
39.
Cytokines are important regulators of materno-fetal immunotolerance in mammals. They act within an intricate network, in which the balance among different cytokines contributes to the success of reproductive processes. Despite numerous studies, however, the role of cytokines at the materno-fetal interface remains largely unknown. Interleukin-1 (IL-1) is a proinflammatory cytokine with many functions in the immune system and in defence against infections. There have been very many studies of the presence and role of IL-1 in human and murine reproduction. Although studies on mammals have shown that IL-1 is an essential mediator in embryo implantation and establishment of pregnancy, mice that are transgenic for most components of the IL-1 family breed normally, suggesting that IL-1 acts in concert with other cytokines at the materno-fetal interface. We recently showed that IL-1 is also expressed by the placenta of non-mammalian vertebrates, including some squamate reptiles and elasmobranch fishes. The expression of IL-1 at the materno-fetal interface in the phylogenetically oldest extant placental vertebrates suggests that IL-1 is a fundamental regulator of materno-fetal relationships. 相似文献
40.
Cusin C Serretti A Lattuada E Lilli R Lorenzi C Smeraldi E 《American journal of medical genetics》2002,114(4):380-390
The aim of our study was to investigate a possible influence of monoamine oxydase A (MAO-A), catechol-O-methyltransferase (COMT), serotonin receptor 2A (5-HT2A), dopamine receptor D2 (DRD2), and dopamine receptor D4 (DRD4) gene variants on timing of recurrence in mood disorders. Gene variants were determined using PCR-based techniques in 550 inpatients affected by recurrent mood disorders (major depressives: n = 212; bipolars: n = 338), rapid cycling mood disorder (n = 81), and 663 controls. We investigated possible genetic influences by comparing illness time course of subjects subdivided according to genotype using multivariate analysis of variance (MANOVA). We could not observe a significantly different time course. No demographic and clinical variables such as sex, age or polarity of onset, presence of psychotic features, genetic loading, or education level influenced the observed results. Our results suggest that MAO-A, COMT, 5-HT2A, DRD2, and DRD4 gene variants are not involved in susceptibility toward different time courses in mood disorders. 相似文献