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   3138篇
  免费   202篇
  国内免费   12篇
耳鼻咽喉   10篇
儿科学   117篇
妇产科学   38篇
基础医学   508篇
口腔科学   44篇
临床医学   265篇
内科学   519篇
皮肤病学   163篇
神经病学   366篇
特种医学   121篇
外科学   286篇
综合类   9篇
一般理论   1篇
预防医学   217篇
眼科学   92篇
药学   294篇
中国医学   6篇
肿瘤学   296篇
  2023年   23篇
  2022年   39篇
  2021年   62篇
  2020年   48篇
  2019年   64篇
  2018年   78篇
  2017年   61篇
  2016年   89篇
  2015年   90篇
  2014年   113篇
  2013年   143篇
  2012年   228篇
  2011年   258篇
  2010年   148篇
  2009年   133篇
  2008年   241篇
  2007年   223篇
  2006年   219篇
  2005年   231篇
  2004年   196篇
  2003年   176篇
  2002年   140篇
  2001年   33篇
  2000年   15篇
  1999年   15篇
  1998年   34篇
  1997年   32篇
  1996年   24篇
  1995年   12篇
  1994年   18篇
  1993年   19篇
  1992年   6篇
  1991年   6篇
  1990年   8篇
  1989年   8篇
  1988年   9篇
  1987年   9篇
  1986年   6篇
  1985年   7篇
  1984年   5篇
  1983年   5篇
  1982年   9篇
  1980年   5篇
  1979年   5篇
  1978年   6篇
  1976年   5篇
  1975年   6篇
  1974年   4篇
  1972年   5篇
  1971年   6篇
排序方式: 共有3352条查询结果,搜索用时 328 毫秒
91.
92.

Background

It is unclear how mortality and causes of death vary between patients and surgical procedures and how occurrence of postoperative complications is associated with prognosis. This study describes long-term mortality rates and causes of death in a general surgical population. Furthermore, we explore the effect of postoperative complications on mortality.

Methods

A single-centre analysis of postoperative complications, with mortality as primary endpoint, was conducted in 4479 patients undergoing surgery. We applied univariate and multivariable regression models to analyse the effect of risk factors, including surgical risk and postoperative complications, on mortality. Causes of death were also explored.

Results

75 patients (1.7 %) died within 30 days after surgery and 730 patients (16.3 %) died during a median follow-up of 6.3 years (IQR 5.8–6.8). Significant differences in long-term mortality were observed with worst outcome for patients undergoing high-risk vascular surgery (HR 1.5; 95 % CI 1.2–1.9). When looking at causes of death, high-risk surgery was associated with a twofold higher risk of cardiovascular death (HR 1.9; 95 % CI 1.2–3.1), whereas the intermediate-risk group had a higher risk of dying from cancer-related causes (HR 1.5; 95 % CI 1.1–2.0). Occurrence of complications—particularly of cardiovascular nature— was associated with worse survival (HR 1.9; 95 % CI 1.3–2.7).

Conclusion

High-risk vascular surgery and occurrence of postoperative complications are important predictors of late mortality. Further focus on these groups of patients can contribute to reduced morbidity. Improvement in quality of care should be aimed at preventing postoperative complications and thus a better outcome in a general surgical population.
  相似文献   
93.

Background

Resuming work after surgical treatment of an unstable pelvic ring injury is often impeded because of residual disability. The aim of this study was to test which factors influence return to work, ability to return to the same job function as before the injury, leaves of absence, and incapacitation after sustaining a pelvic fracture.

Materials and methods

We performed a retrospective study on patients with surgically treated pelvic fractures. Medical records were reviewed to document patients’ demographic data, the extent of follow-up care, diagnosis of the injury (according to the Tile system of classification), type of surgical treatment, injury severity, and the time from trauma to definitive surgery. We also recorded the classification of patients’ physical status according to the American Society of Anesthesiologists (ASA) and details about admission to the intensive care unit (ICU). Patients were interviewed to note the number of days before returning to work and their ability to maintain their previously held jobs.

Results

Fifty patients were included in the study, and their mean age was 46.3 ± 12.6 years. The median time to return to work was 195 days. Twelve patients (24 %) lost their jobs and 17 (34 %) resumed their previous job with a change of tasks. ICU admission and time from trauma to definitive surgery were negatively correlated with return to the previously held job. Returning to the same job tasks was not associated with any of the factors investigated. Polytrauma, ICU admission, and time from trauma to definitive surgery were associated with longer leaves of absence.

Conclusions

Work reintegration after pelvic ring injuries is a major issue for patients and health care systems: 58 % of patients were not able to return to or lost their job. Factors correlated with leaves of absence were injury severity, delayed definitive fixation, and ICU admission.

Level of evidence

IV (case series).
  相似文献   
94.
95.
96.
97.
The predominant testicular gap junctional protein connexin43 (cx43) is located between neighboring Sertoli cells (SCs) and between SCs and germ cells. It is assumed to be involved in testicular development, cell differentiation, initiation, and maintenance of spermatogenesis with alterations of its expression being correlated with various testicular disorders. Because total disruption of the cx43 gene leads to perinatal death, we generated a conditional cx43 knockout (KO) mouse using the Cre/loxP recombination system, which lacks the cx43 gene solely in SCs (SCCx43KO), to evaluate the SC-specific functions of cx43 on spermatogenesis in vivo. Adult SCCx43KO(-/-) mice showed normal testis descent and development of the urogenital tract, but testis size and weight were drastically lower compared with heterozygous and wild-type littermates. Histological analysis and quantitation of mRNA expression of germ cell-specific marker genes revealed a significant reduction in the number of spermatogonia but increased SC numbers/tubule with only a few tubules left showing normal spermatogenesis. Thus, SC-specific deletion of cx43 mostly resulted in an arrest of spermatogenesis at the level of spermatogonia or SC-only syndrome and in intratubular SC clusters. Our data demonstrate for the first time that cx43 expression in SCs is an absolute requirement for normal testicular development and spermatogenesis.  相似文献   
98.
The post-mortem use of modern imaging techniques such as multislice computed tomography (MSCT) is becoming increasingly important as an aid for conventional autopsy. This article presents a case of a 4-month-old boy who died from sudden infant death syndrome (SIDS) with intravascular gas after an intraosseus medication application documented by post-mortem MSCT. It is most likely that the gas entered the body during resuscitation. This case emphasises the advantage of post-mortem imaging as a complementary aid for the autopsy. We conclude that during emergency treatment, the medical staff should be aware of the possibility of causing a gas embolism following intraosseus medication. Resuscitation with an inserted, disconnected intraosseous needle should be avoided.  相似文献   
99.
Introduction: Adequate postoperative analgesia in pediatric patients in the intensive care unit (ICU) matters, since untreated pain is associated with negative outcomes. Compared to routine postoperative patients, children undergoing hypothermia (HT) or extracorporeal membrane oxygenation (ECMO), or recovering after cardiac surgery likely display non-maturational differences in pharmacokinetics (PK) and pharmacodynamics (PD). These differences warrant additional dosing recommendations to optimize pain treatment.

Areas covered: Specific populations within the ICU will be discussed with respect to expected variations in PK and PD for various analgesics. We hereby move beyond maturational changes and focus on why PK/PD may be different in children undergoing HT, ECMO or cardiac surgery. We provide a stepwise manner to develop PK-based dosing regimens using population PK approaches in these populations.

Expert opinion: A one-dose to size-fits-all for analgesia is suboptimal, but for several commonly used analgesics the impact of HT, ECMO or cardiac surgery on average PK parameters in children is not yet sufficiently known. Parameters considering both maturational and non-maturational covariates are important to develop population PK-based dosing advices as part of a strategy to optimize pain treatment.  相似文献   

100.
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