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   24600篇
  免费   1805篇
  国内免费   608篇
耳鼻咽喉   477篇
儿科学   259篇
妇产科学   394篇
基础医学   3738篇
口腔科学   450篇
临床医学   2219篇
内科学   4556篇
皮肤病学   978篇
神经病学   1603篇
特种医学   1512篇
外国民族医学   2篇
外科学   2950篇
综合类   1092篇
现状与发展   1篇
一般理论   10篇
预防医学   1044篇
眼科学   516篇
药学   2578篇
  4篇
中国医学   714篇
肿瘤学   1916篇
  2024年   36篇
  2023年   284篇
  2022年   813篇
  2021年   1190篇
  2020年   689篇
  2019年   809篇
  2018年   888篇
  2017年   819篇
  2016年   1042篇
  2015年   1448篇
  2014年   1613篇
  2013年   1706篇
  2012年   2407篇
  2011年   2215篇
  2010年   1442篇
  2009年   1092篇
  2008年   1441篇
  2007年   1302篇
  2006年   1177篇
  2005年   1031篇
  2004年   799篇
  2003年   770篇
  2002年   600篇
  2001年   295篇
  2000年   176篇
  1999年   165篇
  1998年   111篇
  1997年   106篇
  1996年   72篇
  1995年   58篇
  1994年   67篇
  1993年   44篇
  1992年   37篇
  1991年   37篇
  1990年   38篇
  1989年   28篇
  1988年   28篇
  1987年   26篇
  1986年   21篇
  1985年   11篇
  1984年   19篇
  1983年   8篇
  1982年   8篇
  1981年   10篇
  1979年   3篇
  1978年   3篇
  1976年   3篇
  1974年   3篇
  1972年   5篇
  1969年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
ObjectivesTo investigate the proportion of insulin‐dependent diabetes mellitus (IDDM) patients among diabetic patients undergoing total joint arthroplasty (TJA) and whether insulin dependence is associated with postoperative complications.MethodsA systematic literature search was performed in EMBASE, PubMed, Ovid, Medline, the Cochrane Library, Web of Science, the China Science and Technology Journal Database, and China National Knowledge Infrastructure from the inception dates to 10 September 2019. Observational studies reporting adverse events with IDDM following TJA were included. Primary outcomes were cardiovascular complications, pulmonary complications, kidney complications, wound complications, infection, and other complications within 30 days of surgery. Secondary outcomes were the proportion of IDDM patients among diabetic patients undergoing TJA and its time trend.ResultsA total of 19 studies involving 85,689 participants were included. Among patients undergoing TJA, 26% of diabetic patients had IDDM. Compared with non‐insulin‐dependent diabetes (NIDDM), the incidences of cardiac arrest (risk ratio [RR], 2.346; 95% confidence interval [CI], 1.553 to 3.546), renal failure (relative risk [RR], 2.758; 95% CI, 1.830 to 4.156), deep incisional surgical site infection (RR, 1.968; 95% CI, 1.107 to 3.533), wound dehiscence (RR, 2.209; 95% CI, 1.830 to 4.156), and death (RR, 2.292; 95% CI, 1.568 to 3.349) were all significantly increased in IDDM. A significant time trend was witnessed for the prevalence of IDDM (P = 0.014). There was no statistical significance for organ/space surgical site infection, thrombotic events (deep venous thrombosis/ pulmonary embolism), and revision rates.ConclusionInsulin‐dependent diabetes is an independent high‐risk factor for increased adverse outcomes relative to NIDDM, suggesting that hierarchical and optimal blood glucose management may contribute to reducing the adverse complications after surgery for these patients. In addition, because the risk of sepsis, deep wound infection, organ/space surgical site infection, urinary tract infection, renal insufficiency, and renal failure significantly increase after TJA in IDDM patients, more active postoperative antimicrobial prophylaxis may be needed on the premise of protecting renal function.  相似文献   
62.
BackgroudPatients experiencing acute trauma have limited time for their involvement in shared decision making, which may lead to decisional conflict. The purpose of this study was to evaluate whether providing audiovisual surgical information can reduce decisional conflict when deciding between surgical and nonsurgical treatment in patients with distal radius fractures (DRFs) and to evaluate factors that may affect decisional conflict.MethodsWe prospectively enrolled 50 consecutive patients who presented with acute DRFs and chose to undergo surgery, for which volar plate fixation was recommended. We randomized these patients into 2 groups. The test group was given a video clip of audiovisual surgical information in addition to regular information while the control group was only given regular information. The video clip consisted of the purpose, procedure, and effect of the surgery, precautions and complications after the operation, and other treatment options that could be performed if operation was not performed. At 2 weeks after the surgery, we evaluated patients'' decisional conflict using a decisional conflict scale (DCS). In addition, we evaluated factors that might affect decisional conflict, such as age, dominant hand, comorbidities, history of previous operations, perceived disability, and provision of the video clip.ResultsThe test group showed significantly lower DCS scores than the control group (19.6 vs. 32.1, p = 0.001). In multivariate analysis, younger age and provision of the video clip were associated with lower DCS scores.ConclusionsThis study has demonstrated that providing information through audiovisual media such as video clips could reduce decisional conflict in patients who chose to undergo plate fixation for DRFs. This study also suggests that older patients may need more careful doctor-patient communication as they have more decisional conflict than younger patients.  相似文献   
63.
BackgroundUreaplasma parvum (UP) is commonly isolated in the genitor-urinary tract and may cause various clinical features, including microscopic hematuria (MH). Some UP serovars are more commonly related with specific urogenital disease, but the evidences have been conflicting. This study primarily aimed to research the possible associations between specific UP serotypes and genito-urinary pathogenicity in female patients showing MH with/without chronic micturition urethral pain (CMP).MethodsThis study retrospectively reviewed 276 female patients having MH with/without CMP, who visited health screening center or female infertility clinic. All patients underwent multiplex polymerase chain reaction (PCR) tests with vaginal and urine samples to evaluate the infection rate and serotypes of UP. The antimicrobial susceptibility of UP and the predictors of CMP among UP infected patients were also analyzed. All patients were followed up at least for 6-months.ResultsForty-nine patients (17.8%) showed urinary UP infection. Urinary UP serotyping showed the prevalence of seorvar-1, -3, -6 and -14 were 24.5%, 30.6%, 18.4% and 26.5%, respectively. 79.6% of the urinary UP positive patients accompanied vaginal UP infection. 22 patients of the cohort (8.0%) had CMP whereas serovars-3 and -14 accompanied CMP in 54.5% and 41.0% cases, respectively. No serovars-6 infection case had CMP. 26.4% of the cohort were infertile whereas 10.9% of these infertile patients were positive for urinary tract infection with UP serotype-3 or -14. Doxycycline, josamycin and pristinamycin were the most active antibiotics with the lowest rate of resistance (0.0%) for treating UP. At 1-month post-initial treatment with doxycycline, all UP serotypes were eradicated and no patient complained of urethral discomfort. However, simultaneous urinary and vaginal reinfection of serovar-3 (5 cases) and serovar-5 (1 case) were confirmed at 3-months post-initial doxycycline therapy. The logistic regression analyses revealed that serovars-3 [hazard ratio (HR) 1.354, P value 0.018] and -14 (HR 1.103, P value 0.046) were significantly associated with CMP in female patients having MH.ConclusionsUP serovars-3 and -14 infections could be associated with CMP in female patients having MH. Doxycycline, josamycin and pristinamycin were effective for treating UP. Serovar-3 showed higher reinfection rate than other serotypes after antibiotics treatment.  相似文献   
64.
BackgroundAlthough various studies have been conducted to demonstrate the possibility of Raman spectroscopy (RS) as a diagnostic tool for prostate cancer (PC), it is difficult to use it in the real clinical area because of imitations in various research processes. Therefore, we did a systematic review and meta-analysis about the accuracy in diagnostic use of RS for PC.MethodsA literature search was done using PubMed, Embase, and Cochrane library databases in March 2019 to analyze the accuracy of RS for diagnosis of PC. The accuracy of RS for diagnosis of PC was evaluated by means of pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC).ResultsFive studies were included for qualitative analysis by screening the remaining articles according to the inclusion and exclusion criteria by means of a systematic review. The pooled sensitivity and specificity of RS were 0.89 (95% CI: 0.87–0.91) and 0.91 (95% CI: 0.89–0.93), respectively. The overall PLR and NLR were 9.12 (95% CI: 4.15–20.08) and 0.14 (95% CI: 0.07–0.29), respectively. The DOR of RS demonstrated high accuracy (73.32; 95% CI: 18.43–291.73). The area under the curves (AUCs) of SROC curves was 0.93.ConclusionsRS is an optical diagnostic method with high potential for diagnosis and grading of PC and has advantages of real-time and convenient use. In order to consider real-time use of RS in an actual clinical setting, more studies for standardization and generalization of RS performance and analytical method must be conducted.  相似文献   
65.
BackgroundExcessive portal pressure after massive hepatectomy can cause hepatic sinusoidal injury and have deleterious impacts on hepatic functional recovery, contributing to developing post-hepatectomy liver failure. This study aimed to assess the effects of splanchnic vasoactive agents on hepatic functional recovery and regeneration while clarifying the underlying mechanism, using a 70% hepatectomy porcine model.MethodsEighteen pigs undergoing 70% hepatectomy were involved in this study and divided into three groups: control (n=6), terlipressin (n=6), and octreotide (n=6). Terlipressin (0.5 mg) and octreotide (0.2 mg) were administered 3 times a day for each group with the first dose starting just before surgery until the 7th postoperative day, at which time the surviving pigs were sacrificed. During the period, portal pressure, liver weight, biochemical analysis, histological injury score, and molecular markers were evaluated and compared between groups.ResultsThe 7-day survival rates in the octreotide, terlipressin, and control groups were 100%, 83.3%, and 66.7%, respectively. The portal pressures decreased in both terlipressin and octreotide groups than the control group at 30 minutes, 1 hour and 6 hours after hepatectomy. The amount of regeneration measured by liver weight to body weight ratio at the time of sacrifice in the terlipressin group was smaller than that in the control group (117% vs. 129%, P=0.03). Serum aspartate aminotransferase (AST) and total bilirubin levels at 1 and 6 hours after hepatectomy and prothrombin time/international normalized ratio (PT/INR) at 6 hours after hepatectomy were significantly improved in the terlipressin and octreotide groups compared to the control group. Serum endothelin-1 (ET-1) was significantly lower in the terlipressin group than that in the control group 6 hours after hepatectomy (P<0.01). The histological injury score in the control group was significantly higher than that in the terlipressin group on the 7th postoperative day (P<0.01).ConclusionsSplanchnic vasoactive agents, such as terlipressin and octreotide, could effectively decrease portal pressure and attenuate liver injury after massive hepatectomy.  相似文献   
66.
Bulletin of Environmental Contamination and Toxicology - Heavy metals pollution and salinization of soils are widely distributed in agricultural soils. This study investigated the effects of five...  相似文献   
67.
目的建立人体血清二噁英(polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans,PCDD/Fs)化合物测定方法,为开展二噁英人体健康风险评估提供检测技术手段。方法基于国际二噁英的测定方法—同位素稀释的高分辨气相色谱/高分辨质谱联用法,血清样品经C18柱固相萃取、酸性硅胶柱和活性炭柱净化的前处理方法,用DB-5MS毛细管柱(60 m×0.25 mm×0.25μm)分离,高分辨质谱检测分析。结果本方法的检出限为0.35~3.26 pg/g脂肪计,采用血清国际标准参考物质(SRM 1958)进行方法验证,与SRM 1958给出的参考质量分数值范围对比,17个PCDD/Fs单体浓度测定值均在参考质量分数值范围内,相对标准偏差为2%~19%(n=3)。该方法进一步应用于实际人体血清分析,同位素标记的17个二噁英单体回收率为61%~135%。结论本方法灵敏度和准确度高、方法性能稳定,满足人体血清二噁英检测方法的要求。  相似文献   
68.
目的 探讨人胰弹力蛋白酶Ⅰ (Humanpancreaticelastase 1 ,HPE1 )放射免疫测定 (Radioimmunoassay ,RIA)和核糖核酸酶(Ribonuclease ,RNase)活性检测的临床价值。方法 参照Satake等建立的改良HPE1RIA和Thomas等的改良酸溶性产物法检测 82例正常成年人和 2 2 2例各类患者血清并分析结果。结果  82例健康成人HPE1值为 2 3.8( 3.4ng L) ,RNase活性为 5 7.0 3( 1 2 .1 6 μ ml) ;急性胰腺炎和胰腺癌HPE1 值明显高于其他疾病 (P <0 .0 1 )。联合检测HPE1 、RNase活性可提高胰腺癌的检出率 ( 92 .47% )。结论 HPE1 RIA对急性胰腺炎有诊断价值 ,联合检测HPE1 、RNase活性检测对胰腺癌诊断有一定的临床价值  相似文献   
69.
目的 观察低分子肝素治疗老年人不稳定型心绞痛的疗效。方法 将101例不稳定型心绞痛患者随机分为A、B两组。在常规治疗基础上A组给予低分子肝素腹部皮下注射;B组给予等量生理盐水皮下注射。结果 A组心绞痛发作频率比B组明显减少(P〈0.01)。心电图ST段及T波较对照组明显改善。A组总有效率90%,B组总有效率54%(P〈0.01)。A、B组治疗期间均未见出血等副作用。结论 低分子肝素治疗老年人不稳定  相似文献   
70.
慢性光化性皮炎的病因诊断及治疗   总被引:1,自引:1,他引:0  
目的;探讨慢性光化性皮炎(CAD)的病因,诊断及治疗,方法:查阅文献,对引起CAD的光敏物、发病机理及治疗进行分析,结果:约11%的CAD患者有光敏物接触史;62%光敏性隐匿;27%有慢性皮炎病史;结论:CAD发病与光变态反应有关,避光治疗有效。  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