首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   48061篇
  免费   4452篇
  国内免费   3699篇
耳鼻咽喉   302篇
儿科学   440篇
妇产科学   485篇
基础医学   5692篇
口腔科学   743篇
临床医学   6946篇
内科学   7550篇
皮肤病学   588篇
神经病学   2619篇
特种医学   1931篇
外国民族医学   23篇
外科学   4394篇
综合类   7722篇
现状与发展   15篇
一般理论   7篇
预防医学   2940篇
眼科学   1507篇
药学   5073篇
  81篇
中国医学   2859篇
肿瘤学   4295篇
  2024年   154篇
  2023年   860篇
  2022年   2052篇
  2021年   2645篇
  2020年   1969篇
  2019年   1675篇
  2018年   1769篇
  2017年   1519篇
  2016年   1466篇
  2015年   2181篇
  2014年   2649篇
  2013年   2353篇
  2012年   3488篇
  2011年   3916篇
  2010年   2380篇
  2009年   1863篇
  2008年   2496篇
  2007年   2582篇
  2006年   2496篇
  2005年   2606篇
  2004年   1507篇
  2003年   1344篇
  2002年   1125篇
  2001年   1107篇
  2000年   1148篇
  1999年   1212篇
  1998年   788篇
  1997年   800篇
  1996年   618篇
  1995年   569篇
  1994年   514篇
  1993年   303篇
  1992年   379篇
  1991年   308篇
  1990年   282篇
  1989年   242篇
  1988年   230篇
  1987年   208篇
  1986年   154篇
  1985年   110篇
  1984年   50篇
  1983年   38篇
  1982年   19篇
  1981年   12篇
  1980年   13篇
  1979年   12篇
  1966年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Paget病19例   总被引:9,自引:0,他引:9  
Fu M  Gao S  Wang P 《中华外科杂志》1999,37(7):429-431
目的 提高对Paget病的诊治水平。方法 回顾性分析1987年至1997年收治的19例Paget病的临床表现及诊治方法。结果 本组乳腺Paget病6例,乳腺外13例,其中阴茎,阴囊11例,腹股沟处1例,肛周肛管1例。随访时间0.5-11年,平均5年4个月,随访中3例复发者,其截端切片病理检查均可见病变组织,另1例死于其他疾病。  相似文献   
102.
IntroductionLipoprotein(a)[Lp(a)]consistsofanLDLparticle,inwhichapolipoprotein(a)isatachedtoapolipoproteinB-100throughadisulf...  相似文献   
103.
Rates of prostate cancer (PCa) have increased so dramatically over the last decade that the age adjusted incidence rate for PCa is now greater than that any other cancer among men in the United States. This review, published as a three part series, provides a state-of-art assessment of the PCa problem in its divergent aspects.Part 1 covers epidemiology, incidence and progression. Several epidemiological studies have demostrated that first degree male relatives of men with PCa are at increased risk of developing the disease. Familial and genetic factors as well as medical, anthropometric, dietary, hormonal and occupational factors involved in PCa are discussed. Postmortem examination of the prostate in men without evidence of PCa documented a high frequency of adenocarcinoma. Latent disease occurred as early as the second decade of life. Although there is no significant difference in incidence between Caucasian and African-American males, high grade prostatic intraepithelial neoplasia (HGPIN) is higher in the latter group. While dietary fat, androgens and certain environmental factors may be determinants for PCa, the exact mechanism of tumorigenesis is still relatively unknown. The current thinking of the role of genomic instability, chromosomal alterations, tumor suppressor genes and the androgen receptor are explored.  相似文献   
104.
Three cases of "Top of the basilar" syndrome are reported. The clinical manifestations included the consciousness disturbance, pupillary and oculomotor abnormalities. One of the 3 cases got cortical blindness. It is emphasized that the possibility of the TOB syndrome should be considered when unconsciousness arose suddenly, accompanied by lid, pupil and oculomotor disturbances without the motor and sensory disturbances. Usually, a bilateral symmetric butterfly hypodensity could be found in the thalamus on CT scan. In addition. It was valuable findings that the infarct lesions have been shown in the mesencephalon, pons, cerebellum, occipital and medial temporal lobe on CT scans.  相似文献   
105.
Campylobacter jejuni is a major cause of human enteritis which mimics the inflammatory bowel disease (IBD). In this study, microstructural changes on the surfaces of the murine gastrointestinal tract persistently colonized by Campylobacter jejuni, strain GJ-S131, were investigated by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results revealed that the appearance of the gastrointestinal mucosa in both BALB/C and KM mice resembled that in human with inflammatory bowel disease. Under SEM, the mucosa of the jejunum and ileum, with broken or distorted villi had a "worm eaten" look; crypts were irregular in shape and size, and the mucosa showed atrophy, especially in the colon. Epithelial junctions demonstrated furrows, clefts or deep crevasses, with exudates containing a large number of leukocytes. Cytologic appearances were characterized by microvilli dysplasia and/or atrophy, patchy erosions or necrosis and pelade-like appearance due to absence of microvilli, which were similar to the findings under TEM.
  相似文献   
106.
OBJECTIVE: This study longitudinally described rates of posttraumatic stress disorder (PTSD) in two groups with different levels of severity of exposure to an earthquake in North China. The effects of diagnostic criteria on the frequency of detected PTSD were also examined. METHOD: Subjects were randomly sampled in two villages at different distances from the earthquake epicenter. A total of 181 and 157 subjects were assessed at 3 months and 9 months after the earthquake, respectively, for PTSD by using both DSM-IV and DSM-III-R criteria. The brief version of the World Health Organization Quality of Life Assessment and three subscales of the SCL-90-R were also administered at both assessment points. RESULTS: The village with a higher level of initial exposure to the earthquake and a higher level of postearthquake support had a lower frequency of PTSD than the village with a lower level of initial exposure and less postearthquake support. The rate of onset of DSM-IV PTSD within 9 months for the two villages was 19.8% and 30.3%, respectively. In both villages, the rate of onset of earthquake-related PTSD within 9 months was 24.2% by using DSM-IV criteria and 41.4% by using DSM-III-R criteria. The introduction in DSM-IV of a criterion requiring clinically significant distress or impairment in functioning for a diagnosis of PTSD was a major contributor to the lower rate of DSM-IV PTSD. CONCLUSIONS: PTSD may be as prevalent and persistent in disaster victims in China as in those elsewhere. Prompt and effective postdisaster intervention could mitigate the impact of initial exposure and reduce the probability of PTSD occurrence. Caution should be used in comparing rates of postdisaster PTSD identified by using different diagnostic criteria.  相似文献   
107.
帕司烟肼介入凝胶体外抗结核活性及安全性研究   总被引:1,自引:0,他引:1  
目的 观察帕司烟肼凝胶体外抗结核作用和支气管介入的安全性。方法 手工法、仪器法分别测定帕司烟肼及其凝胶的最小抑菌浓度和最小杀菌浓度及家兔经支气管介入的安全性试验。结果 帕司烟肼凝胶对H37Rv标准株、牛型结核分枝杆菌、草分枝杆菌MIC值分别为0.1、0,1、0.4mg/L,MBC值分别为0,2、0.2和1.6mg/L;帕司烟肼凝胶与帕司烟肼单体MIC、MBC值无显著差异;动物实验表明该药应用安全。结论 帕司烟肼凝胶具有与帕司烟肼单体相同的抗结核菌药效,卡波姆基质不影响帕司烟肼的抗菌活性;以卡波姆为基质的帕司烟肼凝胶应用安全。  相似文献   
108.
109.
The CYP11A gene encodes the cholesterol side-chain cleavage enzyme (P450scc) that catalyzes the first and rate-limiting step for the biosynthesis of sex hormones. A pentanucleotide repeat [(TAAAA)n] polymorphism in the 5' of the CYP11A gene has been reported to be related to the risk of polycystic ovary syndrome, an inherited endocrine disorder characterized by hyperandrogenemia. We investigated the association of this polymorphism with breast cancer risk in a population-based case-control study conducted among Chinese women in Shanghai. Genotype assays were completed for 1015 incident breast cancer cases and 1082 community controls. Three common alleles with 4, 6, or 8 TAAAA repeats were identified in the study population. The frequency of the 8 repeat allele was more common in cases (12.6%) than controls (8.5%) (odds ratio = 1.6, 95% confidence interval = 1.3-1.9; P < 0.0001). Compared to subjects who did not carry this allele, adjusted odds ratios were 1.5 (95% confidence interval = 1.2-1.9) and 2.9 (1.3-6.7) (P for trend, <0.001), respectively, for those who carried one and two copies of this allele. This positive association was observed in both pre- and postmenopausal women and all strata defined by major breast cancer risk factors, including years of menstruation, body mass index, and waist-to-hip ratio. The results from this study indicate that the TAAAA repeat polymorphism near the promoter region of the CYP11A gene may be an important susceptibility factor for breast cancer risk.  相似文献   
110.
左主干狭窄的外科治疗   总被引:3,自引:0,他引:3  
Xu M  Chen X  Guo Z  Chen Z  Gao Y 《中华外科杂志》2000,38(9):649-651
目的 探讨左主干狭窄(LMS)≥50%患者的外科治疗效果。方法 42例LMS的患者接受了冠状动脉旁路移植术(CABG)。平均年龄68.7岁。LMS介于50% ̄75%者16例,大于75%者26例,不稳定型心绞痛29例。按CCSS标准心绞痛分级,Ⅰ级2例,Ⅱ级5例、Ⅲ级17例,Ⅳ级18例。左室射血分数小于50%者24例。结果 术前平均住院时间2.3d人均移植血管3.3根,无手术死亡。术后所有患者心绞痛  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号