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   7798篇
  免费   364篇
  国内免费   42篇
耳鼻咽喉   69篇
儿科学   127篇
妇产科学   114篇
基础医学   1052篇
口腔科学   263篇
临床医学   525篇
内科学   2075篇
皮肤病学   84篇
神经病学   450篇
特种医学   233篇
外科学   1339篇
综合类   29篇
预防医学   221篇
眼科学   121篇
药学   543篇
中国医学   12篇
肿瘤学   947篇
  2023年   46篇
  2022年   103篇
  2021年   140篇
  2020年   83篇
  2019年   122篇
  2018年   141篇
  2017年   106篇
  2016年   121篇
  2015年   125篇
  2014年   167篇
  2013年   196篇
  2012年   308篇
  2011年   352篇
  2010年   193篇
  2009年   179篇
  2008年   317篇
  2007年   341篇
  2006年   280篇
  2005年   331篇
  2004年   316篇
  2003年   305篇
  2002年   305篇
  2001年   304篇
  2000年   275篇
  1999年   248篇
  1998年   104篇
  1997年   71篇
  1996年   80篇
  1995年   67篇
  1994年   62篇
  1993年   68篇
  1992年   238篇
  1991年   215篇
  1990年   203篇
  1989年   210篇
  1988年   167篇
  1987年   162篇
  1986年   172篇
  1985年   122篇
  1984年   95篇
  1983年   95篇
  1982年   52篇
  1979年   64篇
  1978年   53篇
  1977年   44篇
  1975年   40篇
  1974年   50篇
  1973年   47篇
  1972年   45篇
  1971年   40篇
排序方式: 共有8204条查询结果,搜索用时 0 毫秒
991.
We report a case of primary epithelioid hemangioendothelioma arising in the liver. There were no specific findings or signs except for the deformity and multiple lesions of the liver at imaging procedures, which included magnetic resonance imaging. The key to the diagnosis was histological examination of liver biopsy specimens obtained under laparoscopy. Plasma factor VIII activity was elevated, which was also helpful in the diagnosis.  相似文献   
992.
We report the fourth case of simultaneous macroamylasemia and macrolipasemia. A 39-year-old woman had been treated for systemic lupus erythematosus from 1982 to 1993. She was found to have an unexplained increase in serum amylase and lipase activities since 1996. Immunoprecipitation assay showed that amylase was bound to IgA2-kappa and IgA1-kappa (IgA2 > IgA1), whereas lipase was bound to IgA1-kappa. During a follow-up period up to December 1999, the patient did not develop any additional autoimmune or lymphoproliferative disorders. In the situation of atypical clinical features associated with hyperamylasemia and hyperlipasemia, the possibility of macroenzymes should be considered.  相似文献   
993.
The present study investigated the effects of phentolamine (PH) and nitroglycerin (NG) on the hemodynamics of the right heart in patients with cardiac disease. The patients were divided into a well-functioning left heart group (W group, n = 15) and a poorly-functioning left heart group (P group, n = 15). Right cardiac hemodynamic parameters and plasma noradrenaline (NA) and adrenaline (A) concentrations were measured before and after administering PH (0.1 mg/kg, i.v.) or NG (0.6 mg, sublingual). In a parallel animal study we obtained a systemic venous return curve by measuring mean circulatory pressure (MCP), mean right atrial pressure (RAP) and cardiac output, before and after administering PH (0.1 mg/kg, i.v.) or NG (12.5 micrograms/kg, i.v.) to anesthetized open-chest dogs (n = 14). We used MCP data (W group: 7.5 mmHg, P group: 10 mmHg) obtained in a separate series of human studies in our laboratory. We constructed the venous return curve by connecting the MCP point on abscissa with the cardiac index (CI)-RAP plot obtained in the clinical study. We also constructed the right ventricular output curve by connecting the point of -2 mmHg on the abscissa with the CI-RAP plot. We obtained the following results: (1) PH shifted the CI-RAP plot to the left and upwards, while NG shifted the CI-RAP plot to the left almost horizontally on the CI-RAP plane, where CI was plotted on ordinate and RAP on abscissa. The length [formula: see text] C = control point, PH = point after PH) of the shift of CI-RAP plot due to PH was greater in the P group than in W group, while there was no difference in the length [formula: see text] C = control point, NG = point after NG) of the shift of CI-RAP plot due to NG between P and W groups. (2) Both PH and NG significantly elevated plasma NA and A concentrations in both the W and P groups. In the P group, PH increased the plasma NA concentration significantly more than did NG, but both drugs increased plasma A concentration to a similar extent. (3) Both PH and NG significantly decreased the mean pulmonary arterial pressure with NG doing so significantly more than PH.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
994.
995.
BACKGROUND: It has been reported that bepridil is as good as amiodarone in converting persistent atrial fibrillation (AF) to sinus rhythm (SR). The conversion effect of bepridil alone is not always satisfactory, however. The efficacy of pharmacological cardioversion by the combination of bepridil and a class Ic antiarrhythmic drug for persistent AF is studied. METHODS AND RESULTS: The participants comprised 37 consecutive patients in whom pharmacological cardioversion was conducted to treat persistent AF (duration 22.5+/-29.6 months). Each patient first received a class Ia or Ic antiarrhythmic drug, then bepridil alone, then a combined therapy of bepridil at 200 mg/day with a class Ic antiarrhythmic drug at a routine dose. Unaccompanied use of any of the antiarrhythmic drugs achieved pharmacological cardioversion in 14 (38%) of the 37 patients (single therapy group), whereas SR was restored by combination of bepridil and a class Ic antiarrhythmic drug in 22 (combined therapy group) of the remaining 23 patients. The duration of AF was significantly longer in the combined therapy group than in the single therapy group (28.3+/-31.0 vs 7.3+/-4.1 months). CONCLUSION: Combined therapy of bepridil and a class Ic antiarrhythmic drug is efficient for pharmacological cardioversion of refractory long-lasting persistent AF.  相似文献   
996.
Since malignant melanoma is a rare malignancy in Japan, little is known about the cytogenetic abnormalities in Japanese patients. We report a case of malignant melanoma showing complex chromosomal abnormalities. A 70-year-old woman was admitted to our hospital because of anorexia, delirium, and right hemiplegia. Cranial CT disclosed several metastatic brain tumors. Multiple subcutaneous and intra-abdominal metastases were also found. A diagnosis of metastatic malignant melanoma was made by biopsy of a subcutaneous tumor. Chromosomal analysis of the tumor cells disclosed complex karyotypic abnormalities including novel unbalanced whole arm translocations der (8; 14) (q10; q10) and der (11; 15) (q10; q10).  相似文献   
997.
We analyzed the anti-HIV antibody titer by particle agglutination (PA) on 11 HIV seroconversion panels. PA titer increased very rapidly and the titer went up to 1,000 or more within 18.2 days after seroconversion. The results suggest that one to two weeks of duration will be enough to differentiate persons at the early stage of HIV infection from individuals with HIV screening test initially reactive but false positive. In Japan, HIV prevalence is very low and the majority of the HIV screening test-positive (reactive) cases turned out to be false positive. This HIV testing strategy (one to two weeks interval bleeding) will be very practical and useful to differentiate early stage of HIV infection cases from the majority of false positive cases.  相似文献   
998.
We investigated the alterations of dopamine transporter (DAT)-immunopositive cells against MPTP neurotoxicity, in comparison with tyrosine hydroxylase (TH)- immunopositive neurons and glial fibrillary acidic protein (GFAP)-immunopositive cells. This study showed that DAT and TH immunoreactivity was decreased gradually in the striatum and substantia nigra of mice after MPTP treatment. The patterns of the intense TH-immunoreactive fibers and cell bodies were similar to those of DAT-immunoreactive fibers and cell bodies in the striatum and substantia nigra of mice after MPTP treatment. In contrast, GFAP immunoreactivity was increased gradually in the striatum and substantia nigra after MPTP treatment. In our double-labeled immunostaining with anti-DAT and anti-GFAP antibodies, DAT immunoreactivity was observed only in the nigral dopaminergic neurons, but not in the reactive astrocytes. The present results provide further evidence that the functional damage of DAT may precede dopaminergic neuronal death after MPTP treatment, although the decrease in the number of TH-immunopositive neurons was more pronounced than that in the number of DAT-immunopositive neurons. Furthermore, our findings demonstrate that MPTP can selectively injure the dopaminergic neurons which DAT proteins are predominantly distributed on the striatum and substantia nigra. The results provide beneficial information for MPTP-induced neurodegeneration of the nigrostriatal dopaminergic neuronal pathway.  相似文献   
999.

Background

In the Phase III CALIMA trial, benralizumab significantly reduced asthma exacerbations, increased lung function, and alleviated symptoms for patients with severe, uncontrolled eosinophilic asthma. The aim of this subgroup analysis was to evaluate the efficacy and safety of benralizumab for Japanese patients in the CALIMA trial.

Methods

CALIMA was a randomised, controlled trial of 1306 patients (aged 12–75 years; registered at ClinicalTrials.gov: NCT01914757) with severe asthma uncontrolled by medium- to high-dosage inhaled corticosteroids and long-acting β2-agonists (ICS/LABA). Patients received 56 weeks' benralizumab 30 mg either every 4 weeks (Q4W) or every 8 weeks (Q8W; first three doses Q4W), or placebo Q4W. The primary analysis population was patients receiving high-dosage ICS/LABA with blood eosinophils ≥300 cells/μL. This subgroup analysis covered Japanese patients from this group.

Results

Of 83 patients randomised in Japan, 46 were receiving high-dosage ICS/LABA and had blood eosinophils ≥300 cells/μL. Compared with placebo, benralizumab reduced the annual rate of asthma exacerbations by 66% (Q4W; rate ratio 0.34, 95% CI, 0.11–0.99) and 83% (Q8W; rate ratio 0.17, 95% CI, 0.05–0.60); increased prebronchodilator FEV1 by 0.334 L (Q4W; 95% CI, 0.020–0.647) and 0.198 L (Q8W; 95% CI, ?0.118 to 0.514); and decreased total asthma symptom score by 0.17 (Q4W; 95% CI, ?0.82 to 0.48) and 0.24 (Q8W; 95% CI, ?0.87 to 0.40). Percentages of adverse events were consistent with the overall CALIMA group.

Conclusions

Benralizumab reduced annual asthma exacerbations and symptoms, increased lung function, and was well-tolerated by Japanese patients with severe, uncontrolled eosinophilic asthma.  相似文献   
1000.
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