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   5839篇
  免费   273篇
  国内免费   9篇
耳鼻咽喉   24篇
儿科学   134篇
妇产科学   195篇
基础医学   728篇
口腔科学   70篇
临床医学   447篇
内科学   1430篇
皮肤病学   72篇
神经病学   540篇
特种医学   352篇
外科学   948篇
综合类   20篇
一般理论   8篇
预防医学   413篇
眼科学   87篇
药学   278篇
中国医学   4篇
肿瘤学   371篇
  2024年   4篇
  2023年   26篇
  2022年   42篇
  2021年   89篇
  2020年   78篇
  2019年   109篇
  2018年   95篇
  2017年   92篇
  2016年   116篇
  2015年   125篇
  2014年   190篇
  2013年   282篇
  2012年   436篇
  2011年   515篇
  2010年   290篇
  2009年   275篇
  2008年   398篇
  2007年   455篇
  2006年   365篇
  2005年   415篇
  2004年   365篇
  2003年   320篇
  2002年   287篇
  2001年   60篇
  2000年   27篇
  1999年   40篇
  1998年   67篇
  1997年   70篇
  1996年   61篇
  1995年   41篇
  1994年   50篇
  1993年   44篇
  1992年   21篇
  1991年   20篇
  1990年   22篇
  1989年   13篇
  1988年   23篇
  1987年   23篇
  1986年   20篇
  1985年   21篇
  1984年   15篇
  1983年   16篇
  1982年   18篇
  1981年   13篇
  1980年   12篇
  1979年   7篇
  1978年   9篇
  1977年   10篇
  1975年   4篇
  1974年   8篇
排序方式: 共有6121条查询结果,搜索用时 15 毫秒
81.

Objective

To examine variables associated with bone mineral density (BMD) and vertebral deformities in women with rheumatoid arthritis (RA) from 3 northwest European countries.

Methods

Female patients were recruited from rheumatology clinics in Oslo, Norway; Truro, UK; and Amsterdam, The Netherlands (150 total, 50 per center, age 50–70 years, disease duration ≥5 years). Demographic and clinical data were collected and BMD was measured by means of dual energy x‐ray absorptiometry. Associations between demographic and clinical measures on the one hand and BMD and vertebral deformities on the other were investigated by single and multiple regression analyses.

Results

Body mass index (BMI), medication use, RA damage measures, and BMD differed significantly between the 3 centers. Overall, Norwegian patients had the lowest BMI, used more corticosteroids and antiosteoporotic drugs, had lower joint damage measured by Larsen score, and lower BMD at both spine and hip. High age, low BMI, and high cumulative dose of corticosteroids (last 2 years) are related to low BMD. A high Larsen score was associated with low BMD at the hip. Larsen score was the independent determinant of vertebral deformities after correction for center, age, BMI, and BMD.

Conclusion

Data from 3 countries on BMD and vertebral deformities in female patients aged 50–70 years with longstanding RA are presented, demonstrating an association between radiographic RA damage and low BMD and between radiographic RA damage and vertebral deformities.
  相似文献   
82.
Background: The Dutch guideline on hospital policy for the prevention of nosocomial spread of methicillin-resistant Staphylococcus aureus (MRSA) states that patients transferred from hospitals abroad must be placed in strict isolation immediately on admission to a hospital in the Netherlands. Three patients colonized with both MRSA and a multiresistant Acinetobacter were transferred from hospitals in Mediterranean countries to 3 different hospitals in the Netherlands. Despite isolation precautions, Acinetobacter spread in 2 of the 3 hospitals, whereas nosocomial spread of MRSA did not occur. Methods: For outbreak analysis, the Acinetobacter isolates, identified as Acinetobacter baumannii by the use of amplified ribosomal DNA restriction analysis, were comparatively typed by 4 methods. Comparison of isolation measures in the hospitals was performed retrospectively. Results: In the 2 hospitals in which nosocomial spread of Acinetobacter occurred, most of the epidemiologically related isolates were indistinguishable from the index strains. In these 2 hospitals, isolation measures were in concordance with those recommended for the prevention of contact transmission. The precautions of the hospital in which no outbreak occurred included the prevention of airborne transmission. Conclusions: Precautions recommended for multiresistant gram-negative organisms are insufficient for the prevention of nosocomial spread of multiresistant Acinetobacter . The airborne mode of spread of acinetobacters should be taken into account, and guidelines should be revised accordingly. (AJIC Am J Infect Control 1998;26:544-51)  相似文献   
83.
84.
Rheumatoid arthritis (RA) is a debilitating autoimmune disease characterized by chronic inflammation of the synovial joints. Collagen‐induced arthritis (CIA) and proteoglycan‐induced arthritis (PGIA) are mouse models of inflammatory arthritis; CIA is a T helper type 17 (Th17) ‐dependent disease that is induced with antigen in complete Freund's adjuvant, whereas PGIA is Th1‐mediated and is induced using antigen in dimethyldioctadecyl‐ammonium bromide (DDA) as an adjuvant. To investigate whether the type of adjuvant determines the cytokine profile of the pathogenic T cells, we have compared the effect of CFA and DDA on T‐cell responses in a single arthritis model. No differences in incidence or disease severity between aggrecan‐T‐cell receptor transgenic mice immunized with aggrecan in either CFA or DDA were observed. Immunization with CFA resulted in a higher proportion of Th17 cells, whereas DDA induced more Th1 cells. However, the levels of interleukin‐17 (IL‐17) produced by T cells isolated from CFA‐immunized mice after antigen‐specific stimulation were not significantly different from those found in DDA‐immunized mice, indicating that the increased proportion of Th17 cells did not result in significantly higher ex vivo IL‐17 levels. Hence, the choice of adjuvant can affect the overall proportions of Th1 and Th17 cells, without necessarily affecting the level of cytokine production or disease incidence and severity.  相似文献   
85.
86.
87.
88.
89.
Previously reported short‐term results after live kidney donation show no negative consequences for the donor. The incidence of new‐onset morbidity takes years to emerge, making it highly likely that this will be missed during short‐term follow‐up. Therefore, evidence on long‐term outcome is essential. A 10‐year follow‐up on renal function, hypertension, quality of life (QOL), fatigue, and survival was performed of a prospective cohort of 100 donors. After a median follow‐up time of 10 years, clinical data were available for 97 donors and QOL data for 74 donors. Nine donors died during follow‐up of unrelated causes to donation, and one donor was lost to follow‐up. There was a significant decrease in kidney function of 12.9 ml/min (P < 0.001) at follow‐up. QOL showed significant clinically relevant decreases of 10‐year follow‐up scores in SF‐36 dimensions of physical function (P < 0.001), bodily pain (P = 0.001), and general health (P < 0.001). MFI‐20 scores were significantly higher for general fatigue (P < 0.001), physical fatigue (P < 0.001), reduced activity (P = 0.019), and reduced motivation (P = 0.030). New‐onset hypertension was present in 25.6% of the donors. Donor outcomes are excellent 10 years post‐donation. Kidney function appears stable, and hypertension does not seem to occur more frequently compared to the general population.  相似文献   
90.
We evaluated the role of rituximab during remission induction chemotherapy in relapsed aggressive CD20+ non-Hodgkin lymphoma. Of 239 patients, 225 were evaluable for analysis. Randomized to DHAP (cisplatin-cytarabine-dexamethasone)-VIM (etoposide-ifosfamide-methotrexate)-DHAP (cisplatin-cytarabine-dexamethasone) chemotherapy with rituximab (R; R-DHAP arm) were 119 patients (113 evaluable) and to chemotherapy without rituximab (DHAP arm) 120 patients (112 evaluable). Patients in complete remission (CR) and partial remission (PR) after 2 chemotherapy courses were eligible for autologous stem-cell transplantation. After the second chemotherapy cycle, 75% of the patients in the R-DHAP arm had responsive disease (CR or PR) versus 54% in the DHAP arm (P=.01). With a median follow-up of 24 months, there was a significant difference in failure-free survival (FFS24; 50% vs 24% vs, P<.001), and progression free survival (PFS24; 52% vs 31% P<.002) in favor of the R-DHAP arm. Cox-regression analysis demonstrated a significant effect of rituximab treatment on FFS24 (HR 0.41, 95% confidence interval [CI] 0.29-0.57 versus 0.51, 95% CI 0.37-0.70) and overall-survival (OS24: HR 0.60 [0.41-0.89] vs 0.76 [0.52-1.10]) when adjusted for time since upfront treatment, age, World Health Organization performance status, and secondary age-adjusted international prognostic index. These results demonstrate improved FFS and PFS for relapsed aggressive B-cell NHL if rituximab is added to the re-induction chemotherapy regimen.  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