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   5440篇
  免费   309篇
  国内免费   33篇
耳鼻咽喉   71篇
儿科学   138篇
妇产科学   162篇
基础医学   695篇
口腔科学   145篇
临床医学   363篇
内科学   1405篇
皮肤病学   110篇
神经病学   512篇
特种医学   142篇
外科学   914篇
综合类   31篇
预防医学   301篇
眼科学   79篇
药学   227篇
中国医学   15篇
肿瘤学   472篇
  2023年   49篇
  2022年   36篇
  2021年   276篇
  2020年   120篇
  2019年   217篇
  2018年   229篇
  2017年   165篇
  2016年   138篇
  2015年   143篇
  2014年   226篇
  2013年   291篇
  2012年   460篇
  2011年   521篇
  2010年   262篇
  2009年   239篇
  2008年   357篇
  2007年   361篇
  2006年   345篇
  2005年   327篇
  2004年   256篇
  2003年   239篇
  2002年   208篇
  2001年   28篇
  2000年   28篇
  1999年   40篇
  1998年   42篇
  1997年   28篇
  1996年   13篇
  1995年   20篇
  1994年   14篇
  1993年   18篇
  1992年   13篇
  1991年   11篇
  1990年   7篇
  1989年   7篇
  1988年   4篇
  1987年   3篇
  1986年   4篇
  1984年   5篇
  1983年   3篇
  1981年   9篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1974年   2篇
  1947年   1篇
  1944年   1篇
  1942年   1篇
  1936年   1篇
  1920年   1篇
排序方式: 共有5782条查询结果,搜索用时 446 毫秒
1.
2.
PurposeBreast cancer is the most common cancer diagnosed during childbearing age, and fertility preservation is becoming increasingly more essential. However, recent studies indicate a possible poorer response to controlled ovarian hyperstimulation (COH) in cancer patients than in non-cancer controls and a negative impact of BRCA mutations on female fertility. This study aims to evaluate ovarian response and the number of mature oocytes (MII) vitrified in women with breast cancer, with or without BRCA mutation, comparing them to the expected response according to an age-related nomogram.MethodsThis is a retrospective observational study involving sixty-one breast cancer patients who underwent COH for oocyte cryopreservation. The age-specific nomogram was built using 3871 patients who underwent COH due to oocyte donation, fertility preservation for non-medical reasons, or FIVET for male factor exclusively.ResultsThe mean number of oocytes retrieved was 13.03, whereas the mean number of MII oocytes was 10.00. After the application of the z-score, no statistically significant differences were found compared with the expected response in the general population, neither by dividing patients according to the presence or absence of BRCA mutation nor according to the phase in which they initiated stimulation.ConclusionThe results obtained do not support the notion of a negative impact of the BRCA mutation on the ovarian response of women with breast cancer. Women with breast cancer undergoing COH for fertility preservation can expect the ovarian response predicted for their age.  相似文献   
3.
4.
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a...  相似文献   
5.
Background and aimsDespite using sensor-augmented pump therapy (SAPT) with predictive low-glucose management (PLGM), hypoglycemia is still an issue in patients with type 1 Diabetes (T1D). Our aim was to determine factors associated with clinically significant hypoglycemia (<54 mg/dl) in persons with T1D treated with PLGM-SAPT.Methodology: This is a multicentric prospective real-life study performed in Colombia, Chile and Spain. Patients with T1D treated with PLGM-SAPT, using sensor ≥70% of time, were included. Data regarding pump and sensor use patterns and carbohydrate intake from 28 consecutive days were collected. A bivariate and multivariate Poisson regression analysis was carried out, to evaluate the association between the number of events of <54 mg/dl with the clinical variables and patterns of sensor and pump use.Results188 subjects were included (41 ± 13.8 years-old, 23 ± 12 years disease duration, A1c 7.2% ± 0.9). The median of events <54 mg/dl was four events/patient/month (IQR 1–10), 77% of these events occurred during day time. Multivariate analysis showed that the number of events of hypoglycemia were higher in patients with previous severe hypoglycemia (IRR1.38; 95% CI 1.19–1.61; p < 0.001), high glycemic variability defined as Coefficient of Variation (CV%) > 36% (IRR 2.09; 95%CI 1.79–2.45; p < 0.001) and hypoglycemia unawareness. A protector effect was identified for adequate sensor calibration (IRR 0.77; 95%CI 0.66–0.90; p:0.001), and the use of bolus wizard >60% (IRR 0.74; 95%CI 0.58–0.95; p:0.017).ConclusionIn spite of using advanced SAPT, clinically significant hypoglycemia is still a non-negligible risk. Only the identification and intervention of modifiable factors could help to prevent and reduce hypoglycemia in clinical practice.  相似文献   
6.
7.
Because both metabolic (Met Acid) and respiratory acidosis (Resp Acid) have diverse effects on mineral metabolism, it has been difficult to establish whether acidosis directly affects parathyroid hormone (PTH) secretion. Our goal was to determine whether acute Met Acid and Resp Acid directly affected PTH secretion. Three groups of dogs were studied: control, acute Met Acid induced by HCl infusion, and acute Resp Acid induced by hypoventilation. EDTA was infused to prevent acidosis-induced increases in ionized calcium, but more EDTA was needed in Met Acid than in Resp Acid. The PTH response to EDTA-induced hypocalcemia was evaluated also. Magnesium needed to be infused in groups receiving EDTA to prevent hypomagnesemia. The half-life of intact PTH (iPTH) was determined during hypocalcemia when PTH was measured after parathyroidectomy. During normocalcemia, PTH values were greater (p < 0.05) in Met Acid (92 +/- 19 pg/ml) and Resp Acid (77 +/- 22 pg/ml) than in controls (27 +/- 5 pg/ml); the respective pH values were 7.23 +/- 0.01, 7.24 +/- 0.01, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was greater (p < 0.05) in Met Acid (443 +/- 54 pg/ml) than in Resp Acid (267 +/- 37 pg/ml) and controls (262 +/- 48 pg/ml). The half-life of PTH was greater (p < 0.05) in Met Acid than in controls, but the PTH secretion rate also was greater (p < 0.05) in Met Acid than in the other two groups. In conclusion, (1) both acute Met Acid and Resp Acid increase PTH secretion when the ionized calcium concentration is normal; (2) acute Met Acid may increase the bone efflux of calcium more than Resp Acid; (3) acute Met Acid acts as a secretogogue for PTH secretion because it enhances the maximal PTH response to hypocalcemia.  相似文献   
8.
9.
10.
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