全文获取类型
收费全文 | 31020篇 |
免费 | 1660篇 |
国内免费 | 210篇 |
专业分类
耳鼻咽喉 | 278篇 |
儿科学 | 724篇 |
妇产科学 | 836篇 |
基础医学 | 3673篇 |
口腔科学 | 873篇 |
临床医学 | 2473篇 |
内科学 | 7425篇 |
皮肤病学 | 678篇 |
神经病学 | 3369篇 |
特种医学 | 1248篇 |
外国民族医学 | 3篇 |
外科学 | 4498篇 |
综合类 | 152篇 |
一般理论 | 4篇 |
预防医学 | 1361篇 |
眼科学 | 544篇 |
药学 | 2028篇 |
中国医学 | 52篇 |
肿瘤学 | 2671篇 |
出版年
2023年 | 237篇 |
2022年 | 496篇 |
2021年 | 924篇 |
2020年 | 562篇 |
2019年 | 712篇 |
2018年 | 876篇 |
2017年 | 604篇 |
2016年 | 743篇 |
2015年 | 825篇 |
2014年 | 1144篇 |
2013年 | 1395篇 |
2012年 | 2217篇 |
2011年 | 2233篇 |
2010年 | 1246篇 |
2009年 | 1094篇 |
2008年 | 1856篇 |
2007年 | 1786篇 |
2006年 | 1758篇 |
2005年 | 1666篇 |
2004年 | 1562篇 |
2003年 | 1357篇 |
2002年 | 1208篇 |
2001年 | 631篇 |
2000年 | 649篇 |
1999年 | 560篇 |
1998年 | 277篇 |
1997年 | 226篇 |
1996年 | 235篇 |
1995年 | 205篇 |
1994年 | 185篇 |
1993年 | 148篇 |
1992年 | 393篇 |
1991年 | 336篇 |
1990年 | 283篇 |
1989年 | 248篇 |
1988年 | 205篇 |
1987年 | 195篇 |
1986年 | 203篇 |
1985年 | 184篇 |
1984年 | 148篇 |
1983年 | 109篇 |
1982年 | 75篇 |
1981年 | 70篇 |
1980年 | 52篇 |
1979年 | 90篇 |
1974年 | 51篇 |
1973年 | 54篇 |
1972年 | 72篇 |
1971年 | 55篇 |
1970年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
C.O. Francisco A.M. Catai S.C.G. Moura-Tonello S.L.B. Lopes B.G. Benze A.M. Del Vale A.M.O. Leal 《Brazilian journal of medical and biological research》2014,47(5):426-431
The objective of this study was to evaluate cardiorespiratory fitness and pulmonary
function and the relationship with metabolic variables and C-reactive protein (CRP)
plasma levels in individuals with diabetes mellitus (DM). Nineteen men with diabetes
and 19 age- and gender-matched control subjects were studied. All individuals were
given incremental cardiopulmonary exercise and pulmonary function tests. In the
exercise test, maximal workload (158.3±22.3 vs 135.1±25.2, P=0.005),
peak heart rate (HRpeak: 149±12 vs 139±10, P=0.009), peak
oxygen uptake (VO2peak: 24.2±3.2 vs 18.9±2.8,
P<0.001), and anaerobic threshold (VO2VT: 14.1±3.4 vs
12.2±2.2, P=0.04) were significantly lower in individuals with diabetes than in
control subjects. Pulmonary function test parameters, blood pressure, lipid profile
(triglycerides, HDL, LDL, and total cholesterol), and CRP plasma levels were not
different in control subjects and individuals with DM. No correlations were observed
between hemoglobin A1C (HbA1c), CRP and pulmonary function test and cardiopulmonary
exercise test performance. In conclusion, the results demonstrate that nonsmoking
individuals with DM have decreased cardiorespiratory fitness that is not correlated
with resting pulmonary function parameters, HbA1c, and CRP plasma levels. 相似文献
994.
Lambrechts D Poesen K Fernández-Santiago R Al-Chalabi A Del Bo R Van Vught PW Khan S Marklund SL Brockington A van Marion I Anneser J Shaw C Ludolph AC Leigh NP Comi GP Gasser T Shaw PJ Morrison KE Andersen PM Van den Berg LH Thijs V Siddique T Robberecht W Carmeliet P 《Journal of medical genetics》2009,46(12):840-846
BACKGROUND: Targeted delivery of the angiogenic factor, vascular endothelial growth factor (VEGF), to motor neurons prolongs survival in rodent models of amyotrophic lateral sclerosis (ALS), while mice expressing reduced VEGF concentrations develop motor neuron degeneration reminiscent of ALS, raising the question whether VEGF contributes to the pathogenesis of ALS. An initial association study reported that VEGF haplotypes conferred increased susceptibility to ALS in humans, but later studies challenged this initial finding. Methods and findings: A meta-analysis was undertaken to critically reappraise whether any of the three common VEGF gene variations (-2578C/A, -1154G/A and -634G/C) increase the risk of ALS. Over 7000 subjects from eight European and three American populations were included in the analysis. Pooled odds ratios were calculated using fixed-effects and random-effects models, and four potential sources of heterogeneity (location of disease onset, gender, age at disease onset and disease duration) were assessed. After correction, none of the genotypes or haplotypes was significantly associated with ALS. Subgroup analysis by gender revealed, however, that the -2578AA genotype, which lowers VEGF expression, increased the risk of ALS in males (OR = 1.46 males vs females; 95% CI = 1.19 to 1.80; p = 7.8 10E-5), even after correction for publication bias and multiple testing. CONCLUSIONS: This meta-analysis does not support the original conclusion that VEGF haplotypes increase the risk of ALS in humans, but the significant association of the low-VEGF -2578AA genotype with increased susceptibility to ALS in males reappraises the link between reduced VEGF concentrations and ALS, as originally revealed by the fortuitous mouse genetic studies. 相似文献
995.
Marie-Dominique Beaulieu Louise Samson Guy Rocher Marc Rioux Laurier Boucher Claudio Del Grande 《BMC medical education》2009,9(1):31-9
Background
Collaboration between physicians in different specialties is often taken for granted. However, poor interactions between family physicians and specialists contribute significantly to the observed discontinuity between primary and specialty care. The objective of this study was to explore how collaboration between family physicians and specialists was conceptualised as a competency and experienced in residency training curricula of four faculties of medicine in Canada. 相似文献996.
Anna Maria Chiaravalli Giovanna Finzi Valentina Bertolini Stefano La Rosa Carlo Capella 《Virchows Archiv : an international journal of pathology》2009,455(6):527-531
A case of a colonic carcinoma showing a pancreatic acinar cell differentiation is described for the first time. A 65-year-old
woman underwent surgical resection for an ulcerated protruding tumour of 4 × 2.5 cm in size on the anterior wall of the sigmoid
colon. Histologically, tumour cells were organized in acinar structures resembling pancreatic acini and in solid nests and
ribbons or diffusely infiltrated as poorly cohesive cells. Lymph nodes and femur metastases displayed the same histological
features. The ultrastructural analysis of the primary tumour indicated the presence of zymogen-like granules in the cytoplasm
of tumour cells. Immunohistochemically, both acinar and diffuse patterns of growth showed an intense staining for trypsin,
chymotrypsin and BCL10 and a weaker immunoreactivity for lipase and carboxyl ester hydrolase. Most tumour cells were cytokeratin
20, CDX2 and p53 positive; whereas, mucin (MUC)2 immunoreactivity was observed only in the signet ring cells present in the
diffuse pattern and chromogranin A in rare isolated tumour cells. No immunoreactivity was observed for cytokeratin 7, MUC1,
MUC5AC, pancreatic amylase or PDX1. There was no evidence of a pancreatic acinar cell carcinoma or of heterotopic pancreatic
tissue. A colonic origin ought to be suspected when a metastatic carcinoma of unknown primary shows an acinar differentiation. 相似文献
997.
Ibon Jaunarena Ruben Ruiz Mikel Gorostidi Paloma Cobas Marisa Avila David Del Valle Juan Cespedes Arantza Lekuona 《Journal of minimally invasive gynecology》2019,26(5):954-959
Study ObjectiveTo assess the efficacy of Tissucol Duo (Baxter AG, Vienna, Austria) fibrin sealant in decreasing the incidence of lymphocele (LC) after pelvic laparoscopic lymph node dissection using harmonic shears.DesignRandomized controlled trial (Canadian Task Force classification level I).SettingTertiary referral and educational center.PatientsSeventy-four patients randomized to the use of sealant per hemipelvis.InterventionFibrin sealant.Measurements and Main ResultsAfter bilateral pelvic lymphadenectomy a fibrin sealant was used in 1 hemipelvis but not the other, applied in 41 patients (55.4%) to the left and 33 patients (44.6%) to the right hemipelvis. The primary outcome was the incidence of LC after surgery in symptomatic and asymptomatic patients. Imaging (ultrasound, computed tomography, and magnetic resonance) was performed to detect LC at 3, 6, and 12 months after surgery. Overall, 26 patients (35.1%) developed LC, and 4 were symptomatic (5.4%). Allowing patients to serve as their own treatment group and control, the hemipelvis treated with Tissucol Duo corresponding to the treatment group and that not treated to the control group, LCs were found in 17 (23%) and 14 (19%) cases, respectively, but the difference was not significant. The mean initial LC maximum diameter was 27.1 mm (standard deviaiotn, 35.2), and LCs tended to decrease in size during the first year to a mean of 8.7 mm.ConclusionApplication of Tissucol Duo fibrin sealant after laparoscopic pelvic lymphadenectomy using ultrasonic shears does not decrease the occurrence of symptomatic or asymptomatic LC. 相似文献
998.
Verônica N. Lobach Maíra Casalechi Cynthia Dela Cruz Maria T. Pereira Helen L. Del Puerto 《Human fertility (Cambridge, England)》2019,22(1):33-38
Granulosa cells control oocyte maturation through paracrine signalling and changes to the microenvironment around the oocyte. Apoptosis occurs as a physiological mechanism of granulosa cell renewal, but how it relates with the ovarian response to induced ovulation is still unclear. Therefore, this study evaluated apoptosis-related gene expression levels in granulosa cells of patients undergoing controlled ovarian stimulation. We enrolled prospectively 59 consecutive IVF patients referred to a tertiary academic hospital for couple infertility treatment. Luteinized granulosa cells were isolated from follicular fluid and the RNA was extracted, reverse-transcribed and the gene expression of apoptosis inducers (caspase-3, caspase-8 and bax) and inhibitor (Bcl-2) was quantified by real-time polymerase chain reaction. Caspase-3 gene expression correlated negatively with the number of pre-ovulatory follicles (Spearman’s r?= ?0.308), the number of collected oocytes (r?= ?0.451), the number of mature oocytes (r?= ?0.526), the number of fertilized oocytes (r?= ?0.439) and the number of viable embryos (r?= ?0.443, all statistically significant at p?0.02 level). No such associations were found with caspase-8, bax or bcl-2. These preliminary findings suggest that increased caspase-3 gene expression in granulosa cells is associated with a worse ovulatory response in humans. 相似文献
999.
Rafael Campos Mário A. Claudino Mariana G. de Oliveira Carla F. Franco-Penteado Fernanda Del Grossi Ferraz Carvalho Tiago Zaminelli Edson Antunes Gilberto De Nucci 《The journal of sexual medicine》2019,16(4):500-511