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   6627篇
  免费   469篇
  国内免费   215篇
耳鼻咽喉   54篇
儿科学   121篇
妇产科学   16篇
基础医学   491篇
口腔科学   27篇
临床医学   750篇
内科学   1666篇
皮肤病学   35篇
神经病学   235篇
特种医学   66篇
外科学   1151篇
综合类   800篇
预防医学   419篇
眼科学   41篇
药学   1187篇
  6篇
中国医学   157篇
肿瘤学   89篇
  2024年   7篇
  2023年   105篇
  2022年   139篇
  2021年   283篇
  2020年   251篇
  2019年   245篇
  2018年   240篇
  2017年   226篇
  2016年   171篇
  2015年   239篇
  2014年   435篇
  2013年   574篇
  2012年   457篇
  2011年   471篇
  2010年   387篇
  2009年   348篇
  2008年   284篇
  2007年   324篇
  2006年   259篇
  2005年   205篇
  2004年   168篇
  2003年   189篇
  2002年   173篇
  2001年   137篇
  2000年   129篇
  1999年   104篇
  1998年   78篇
  1997年   102篇
  1996年   65篇
  1995年   62篇
  1994年   43篇
  1993年   49篇
  1992年   30篇
  1991年   23篇
  1990年   21篇
  1989年   25篇
  1988年   26篇
  1987年   32篇
  1986年   19篇
  1985年   23篇
  1984年   23篇
  1983年   15篇
  1982年   24篇
  1981年   20篇
  1980年   21篇
  1979年   11篇
  1978年   13篇
  1977年   9篇
  1976年   9篇
  1974年   6篇
排序方式: 共有7311条查询结果,搜索用时 234 毫秒
1.
2.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  相似文献   
3.
4.
Iron deficiency anemia is often listed among potential adverse effects of gastric acid-suppressive medications, given that gastric acidity promotes intestinal absorption of nonheme iron. Additionally, the antacid calcium carbonate can inhibit iron absorption. However, there is little direct clinical evidence that proton-pump inhibitors, histamine-2 receptor antagonists, or calcium carbonate cause iron deficiency anemia. Most case reports have had substantial limitations (e.g., minimal follow-up and presence of other causes of iron deficiency), and retrospective cohort studies have lacked sufficient patient-specific detail to make strong causal inferences. We present 2 cases—both with detailed, prospective 10-year follow-up—in which combinations of proton-pump inhibitors, histamine-2 receptor antagonists and calcium carbonate were clearly associated with development of iron deficiency anemia. Overt iron-deficiency anemia is probably uncommon in patients who use acid-modifying medications and who have no other conditions that predispose to iron deficiency. Nevertheless, clinicians should be aware of this potential complication, given widespread use of these agents.  相似文献   
5.
6.
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   
7.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions.  相似文献   
8.
Diabetes is a complex, chronic metabolic disorder affecting approximately 9.3% of the adult population with the estimated number of adults with diabetes worldwide having more than tripled since 2000. This increase has largely been attributed to global urbanization and lifestyle changes. Diabetes affects 10–15% of the surgical population. These patients are frequently elderly, have complex medical co-morbidities and present for both high-risk elective and emergency surgery. This multisystem disease poses a significant challenge to both anaesthesia and surgery with patients with diabetes demonstrating higher morbidity and mortality rates compared to their non-diabetic counterparts. It is crucial that good glycaemic control is maintained throughout the perioperative period as this has been shown to correlate with positive patient outcomes. It is well-recognized that a co-ordinated, multidisciplinary approach aimed at optimizing every point in the patient pathway from GP referral to post-discharge care is required to obtain the best outcomes for the surgical patient with diabetes. The anaesthetist has a key role in the perioperative diabetes multidisciplinary team. Patients themselves are well experienced in manging their own diabetes and should be involved in doing so whenever possible.  相似文献   
9.
10.
Central illustration: geographic distribution of the 49 centres participating in the FRENSHOCK registry (35 academic hospitals, 10 general hospitals and four private clinics). Inclusion per centre varied from 1 to 72 patients.
  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