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   10066篇
  免费   526篇
  国内免费   86篇
耳鼻咽喉   105篇
儿科学   127篇
妇产科学   80篇
基础医学   1315篇
口腔科学   255篇
临床医学   577篇
内科学   2556篇
皮肤病学   240篇
神经病学   819篇
特种医学   440篇
外科学   1931篇
综合类   51篇
一般理论   1篇
预防医学   229篇
眼科学   98篇
药学   551篇
中国医学   22篇
肿瘤学   1281篇
  2024年   9篇
  2023年   94篇
  2022年   153篇
  2021年   311篇
  2020年   141篇
  2019年   232篇
  2018年   280篇
  2017年   218篇
  2016年   304篇
  2015年   298篇
  2014年   359篇
  2013年   399篇
  2012年   631篇
  2011年   716篇
  2010年   410篇
  2009年   375篇
  2008年   577篇
  2007年   660篇
  2006年   627篇
  2005年   642篇
  2004年   573篇
  2003年   525篇
  2002年   547篇
  2001年   144篇
  2000年   136篇
  1999年   138篇
  1998年   137篇
  1997年   141篇
  1996年   83篇
  1995年   95篇
  1994年   50篇
  1993年   66篇
  1992年   61篇
  1991年   65篇
  1990年   63篇
  1989年   53篇
  1988年   49篇
  1987年   45篇
  1986年   34篇
  1985年   24篇
  1984年   20篇
  1983年   28篇
  1982年   18篇
  1981年   13篇
  1980年   12篇
  1979年   16篇
  1978年   14篇
  1977年   10篇
  1975年   11篇
  1974年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
We sometimes experience patients with persistent or progressive arytenoid edema, among which residual or recurrent cancer is often accompanied. Because it is difficult to distinguish tumour rest or recurrence from normal tissue sequelae in the early period after irradiation, it is important to know both the contributing factors for arytenoid edema, and the incidence of residual or recurrent tumours in patients with postirradiation laryngeal edema. We therefore reviewed the charts of 67 patients with early laryngeal carcinoma who had received a curative dose of irradiation in the last 5 years. Fourteen patients (20.9%) had moderate or severe laryngeal edema persisting for or developing at more than 3 months after completion of a course of definitive radiotherapy. The incidence was highest in supraglottic T2 disease, followed by glottic T2 tumour. Of the 14 patients with edema, six (42.9%) had persistent or recurrent disease. The primary disease was uncontrolled in 18 patients, 17 of whom received successful salvage surgery. In patients without residual tumours, the edema was usually moderate and resolved within a year, although four patients had chronic edema lasting more than a year after treatment. All four had supraglottic T2 lesions and received 70 Gy of X-ray. We also reviewed, for sake of comparison, the records of 38 patients treated with radiotherapy at doses of more than 40 Gy between l975 and 1980, when endoscopic microsurgery for laryngeal cancer was introduced as a primary part of treatment. The incidence of persistent or late developed edema over the period, though not significant, was 36.8%: nearly twice that of the last 5 years. Microscopic endolaryngeal surgical procedures seem to have been a causal factor for edema in this period.  相似文献   
52.
We investigated the clinical statistics of the operations and inpatients since the establishment of the department in June 1994 up to May 1999. The total number of inpatients was 1,269 (1,047 males and 222 females), and a total of 1,098 operations were performed. Extracorporeal shock wave lithotriopy (ESWL) was also introduced in 1997, and in addition, it seemed that the number of operations and inpatients would be increasing in future.  相似文献   
53.
PURPOSE: Squamous cell carcinoma (SCC) and adenocarcinoma of the lung are currently subject to similar treatment regimens despite distinct differences in histology and epidemiology. The aim of this study is to identify a molecular target with diagnostic and therapeutic values for SCC. EXPERIMENTAL DESIGN: Genes specifically up-regulated in SCC were explored through microarray analysis of 5 SCCs, 5 adenocarcinomas, 10 small cell lung carcinomas, 27 normal tissues, and 40 cancer cell lines. Clinical usefulness of these genes was subsequently examined mainly by immunohistochemical analysis. RESULTS: Seven genes, including aldo-keto reductase family 1, member B10 (AKR1B10), were identified as SCC-specific genes. AKR1B10 was further examined by immunohistochemical analysis of 101 non-small cell lung carcinomas (NSCLC) and its overexpression was observed in 27 of 32 (84.4%) SCCs and 19 of 65 (29.2%) adenocarcinomas. Multiple regression analysis showed that smoking was an independent variable responsible for AKR1B10 overexpression in NSCLCs (P < 0.01) and adenocarcinomas (P < 0.01). AKR1B10 staining was occasionally observed even in squamous metaplasia, a precancerous lesion of SCC. CONCLUSION: AKR1B10 was overexpressed in most cases with SCC, which is closely associated with smoking, and many adenocarcinoma cases of smokers. These results suggest that AKR1B10 is a potential diagnostic marker specific to smokers' NSCLCs and might be involved in tobacco-related carcinogenesis.  相似文献   
54.
Functional involvement of endogenous anxiogenic neuropeptide in brains]   总被引:1,自引:0,他引:1  
Neuronal GABA(A)/benzodiazepine and monoamine receptors participate in anxiety. Diazepam binding inhibitor (DBI), an endogenous anxiogenic neuropeptide, significantly increases in brains only after treatment with psychological stress, and this increase is completely abolished by benzodiazepines. Therefore, it is through that DBI may be involved in anxiogenesis produced by psychological stress. Furthermore, increases in cerebral DBI are observed in patients with several disorders accompanying anxiety and fear, which suggest that cerebral DBI may be an essential factor for anxiogenesis, and that it may be, at least in part, a biological index to evalulate anxiety.  相似文献   
55.
Objective Dementia with Lewy bodies (DLB) is the second-most common form of neurodegenerative dementia after Alzheimer''s disease (AD). Falls are a vital prognostic factor in patients with dementia and are a characteristic feature of DLB. This study investigated the screening potential of the fall risk evaluation for DLB and compared it with that of AD to facilitate an accurate diagnosis. Methods We enrolled patients diagnosed with DLB (n=410) and AD (n=2,683) and categorized the participants into 3 groups depending on their physical ability, age, cognitive function, and fall events. Using the Fall Risk Index-21 (FRI-21) questionnaire, we evaluated and comparatively analyzed the fall risk between DLB and AD patients in three defined groups of participants. Results The FRI-21 score was significantly higher in DLB patients than in AD patients in every group. Using this score, we were able to distinguish between DLB and AD patients in each group. Among the three groups, the group with a young age, relatively mild cognitive dysfunction, and no fall events exhibited the best specificity for DLB (0.895). Conclusions The FRI-21 is a useful tool for screening for DLB and differentiating it from AD. This questionnaire can be used at a relatively early stage of the disease in young patients with mild cognitive dysfunction and no history of falling. These preliminary results need to be validated in an interventional study to evaluate the effectiveness of rehabilitative measures and daily environmental changes carried out to prevent falls using this tool.  相似文献   
56.
The effect of renal dysfunction on clinical outcomes following fractional flow reserve (FFR)-guided deferral of revascularization remains unelucidated.We retrospectively analyzed 224 patients with atherosclerotic coronary lesions who underwent deferred revascularization based on an FFR of >0.80. The median follow-up interval was 28.1 months. Patients were divided into 2 groups: the hemodialysis (HD) and the non-HD group. The non-HD group was further classified into 2 subgroups according to their estimated glomerular filtration rate (eGFR) level: eGFR <45, equivalent to chronic kidney disease stage 3b-5 and eGFR ≥45. We evaluated major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, and any revascularization.MACE occurred in 36 patients (16.1%). The rate of HD was significantly higher in the MACE group (19% vs 6%, P < .01). In non-HD patients, the eGFR was significantly lower in the MACE group (51.2 vs 63.2 mL/min/1.73 m2, P < .01). Overall, univariate Cox regression analysis revealed a significant relationship between HD and MACE (HR 2.91, P = .01), as did the multivariate model (HR 2.90, P = .01). Of the MACE, more deaths occurred in HD patients (15.8% vs 2.9%, P = .03). Among non-HD patients, eGFR <45 (HR 2.70, P = .02), FFR (per 0.01, HR 0.87, P < .01), and low-density lipoprotein cholesterol (per 10 mg/dL, HR 1.17, P = .02) were independent predictors of MACE. Any revascularization was more common in patients with eGFR<45 than in those with eGFR ≥45 (21.4% vs 7.3%, P = .02). Kaplan–Meier estimates revealed that the HD group showed a significantly lower MACE-free survival rate than the nonHD group (log-rank P < .01). In non-HD patients, the eGFR<45 group showed a lower MACE-free survival rate than the eGFR ≥45 group (log-rank P = .01).HD and reduced eGFR in non-HD patients were associated with adverse cardiac events after FFR-guided deferral of revascularization.  相似文献   
57.
The in vivo antitumor activity and toxicity of a newly synthesized polymeric prodrug of cisplatin was investigated and also compared with plain cisplatin. The prodrug included a dicarboxymethyl-dextran conjugate of cisplatin (DCM-Dex/CDDP). DCM-Dex/CDDP was i.v. injected in mice bearing s.c. Colon 26 mouse colon cancer cells. The tissue distribution of platinum was thereafter determined by flameless atomic absorption spectrophotometry. The platinic concentration of the organs showed a high rate of retention at 24 h after injection in the DCM-Dex/CDDP-treated mice. No biochemical or hematologically adverse effects were observed. In addition, DCM-Dex/CDDP showed a significantly higher antitumor activity than cisplatin alone. These results indicate that DCM-Dex/CDDP may therefore be a potentially effective cancer chemotherapy.  相似文献   
58.
Myocardial infarction in Kawasaki disease: clinical analyses in 195 cases   总被引:3,自引:0,他引:3  
We analyzed clinical data from 195 patients (141 boys) with myocardial infarction complicating Kawasaki disease, collected from 74 major hospitals in Japan. The myocardial infarction usually occurred within the first year of illness, but 27.2% of the patients had myocardial infarction more than 1 year later. In 63% of the patients it occurred during sleep or at rest. The main symptoms of acute myocardial infarction were shock, unrest, vomiting, abdominal pain, and chest pain; chest pain was much more frequently recognized in the survivors and in older patients. The myocardial infarctions were asymptomatic in 37% of the patients. Twenty-two percent of the patients died during the first attack. Sixteen percent of the survivors of a first attack had a second attack. Forty-three percent of all survivors of the first or subsequent attack are doing well; however, others have some type of cardiac dysfunction, such as mitral regurgitation, decreased ejection fraction of the left ventricle, or left ventricular aneurysm. Coronary angiographic studies indicate that in most of the fatal cases there was obstruction either in the main left coronary artery or in both the main right coronary artery and the anterior descending artery. In survivors, one-vessel obstruction was frequently recognized, particularly in the right coronary artery.  相似文献   
59.
α1-Adrenoceptors mediate contraction of iris dilator smooth muscle and hence pupil dilatation. We compared the ability of i.v. bolus injections of alfuzosin, doxazosin, naftopidil, prazosin, tamsulosin and terazosin to antagonise phenylephrine-induced mydriasis relative to their potency for inhibiting phenylephrine-induced elevations of intraurethral pressure (IUP) in rabbits. Moreover, we compared the ability of these drugs to induce miosis in conscious rabbits in the absence of phenylephrine. All antagonists inhibited the effects of phenylephrine on pupil size and IUP, and the ratio of the respective ED50 values was close to unity in all cases. The doses required to induce statistically significant miosis in the absence of phenylephrine were 30- to 100-fold higher than those inhibiting phenylephrine-induced mydriasis for all antagonists, except for naftopidil. Moreover, the miotic effects of all α1-adrenoceptor antagonists were fully reversible within 8 h. We conclude that alfuzosin, doxazosin, naftopidil, prazosin, tamsulosin and terazosin inhibit phenylephrine-induced mydriasis in the same dose range as they inhibit elevations in IUP. Higher doses of all antagonists are required to induce miosis in the absence of an exogenous agonist, and such miosis is always reversible within hours.  相似文献   
60.
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