全文获取类型
收费全文 | 514篇 |
免费 | 20篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 22篇 |
妇产科学 | 31篇 |
基础医学 | 42篇 |
口腔科学 | 10篇 |
临床医学 | 55篇 |
内科学 | 114篇 |
皮肤病学 | 20篇 |
神经病学 | 10篇 |
特种医学 | 131篇 |
外科学 | 25篇 |
综合类 | 8篇 |
预防医学 | 28篇 |
眼科学 | 4篇 |
药学 | 25篇 |
肿瘤学 | 26篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 22篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 10篇 |
2009年 | 23篇 |
2008年 | 9篇 |
2007年 | 24篇 |
2006年 | 12篇 |
2005年 | 18篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 35篇 |
1997年 | 19篇 |
1996年 | 26篇 |
1995年 | 18篇 |
1994年 | 21篇 |
1993年 | 14篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 13篇 |
1989年 | 21篇 |
1988年 | 30篇 |
1987年 | 12篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1973年 | 1篇 |
1947年 | 1篇 |
1921年 | 7篇 |
排序方式: 共有552条查询结果,搜索用时 15 毫秒
31.
The palpation and enucleation of occult insulinomas (less than 15 mm) can be a difficult surgical problem even with good arteriographic localization. In the authors' limited experience, confirmation of arteriographic findings by pancreatic venous sampling provided little additional localizing information. However, if arteriography is negative or equivocal, venous sampling can indicate the segment of pancreas to be "blindly" resected if the adenoma is not palpable. Venous sampling may be misleading in polyendocrine syndromes because of the frequency of multiple adenomas and variable hormone production. 相似文献
32.
WL Craig CR Ramsay S Fielding ZH Krukowski 《Annals of the Royal College of Surgeons of England》2014,96(6):466-474
Introduction
This study describes variability of treatment for differentiated thyroid cancer among thyroid surgeons, in the context of changing patterns of thyroid surgery in the UK.Methods
Hospital Episodes Statistics on thyroid operations between 1997 and 2012 were obtained for England. A survey comprising six scenarios of varying ‘risk’ was developed. Patient/tumour information was provided, with five risk stratified or non-risk stratified treatment options. The survey was distributed to UK surgical associations. Respondent demographics were categorised and responses analysed by assigned risk stratified preference.Results
From 1997 to 2012, the Hospital Episode Statistics data indicated there was a 55% increase in the annual number of thyroidectomies with a fivefold increase in otolaryngology procedures and a tripling of cancer operations. Of the surgical association members surveyed, 264 respondents reported a thyroid surgery practice. Management varied across and within the six scenarios, and was not related consistently to the level of risk. Associations were demonstrated between overall risk stratified preference and higher volume practice (>25 thyroidectomies per year) (p=0.011), fewer years of consultant practice (p=0.017) and multidisciplinary team participation (p=0.037). Logistic regression revealed fewer years of consultant practice (odds ratio [OR]: 0.96/year in practice, 95% confidence interval [CI]: 0.922–0.997, p=0.036) and caseload of >25/year (OR 1.92, 95% CI: 1.044–3.522, p=0.036) as independent predictors of risk stratified preference.Conclusions
There is a substantial contribution to thyroid surgery in the UK by otolaryngology surgeons. Adjusting management according to established case-based risk stratification is not widely applied. Higher caseload was associated with a preference for management tailored to individual risk. 相似文献33.
Cheryl Jacobs Danielle M. Berglund Jennifer F. Wiseman Catherine Garvey Dawn B. Larson Margaret Voges Carmen Radecki Breitkopf Hassan N. Ibrahim Arthur J. Matas 《American journal of transplantation》2019,19(5):1498-1506
Short‐term studies have demonstrated that nondirected donors (NDDs) have psychosocial outcomes that are similar to donors who donate directly, but long‐term studies have not been done. NDDs at our center were surveyed regarding motivation; support during donation; stress related to donation; regret; financial resources used for donation; preferences about communication with the recipient; and cost reimbursement. Of 100 NDDs who donated at our center in the last 20 years, 95 remain in contact with us, and 77 responded to our survey (mean ± standard deviation [SD] 6.7 ± 4 years postdonation). The most common motivation for donation was the desire to help another (99%). Many NDDs received support from family, friends, and employers. NDDs voiced stress about the possibility of recipient kidney rejection, physical consequences to themselves, and financial burden. Only one donor expressed regret. Almost half wanted some recipient information at donation; 61% preferred routine recipient status updates; 56% believed meeting the recipient should occur at any mutually agreeable time; and 55% endorsed reimbursement for expenses. Stressors for NDDs are analogous to those of directed donors; NDDs prefer having some information about the recipient and prefer to be given a choice regarding the timing for communication with the recipient. NDDs supported donation being financially neutral. 相似文献
34.
1) By the action of thiouracil the follicular cell is not brought into the state of physiological inactivity and it shows signs of apparent secretion which differ however in details remarkably from the effective secretion stage. 2.) The quantity of follicular cells in mitosis is temporarily increased to the multiple. This disturbance is the result of the inhibition of caryokinesis in the stage of metaphase. 3) The absolute quantities of ribonucleic and of desoxyribonu-cleic acid are considerably reduced. 4) The ratio KNA/DNA shows a decrease to a fractional part of the normal value, according to the increase of the cell mass. 相似文献
35.
Left ventricular volumes measured by MR imaging 总被引:9,自引:0,他引:9
We assessed the potential of proton magnetic resonance (MR) imaging for accurately measuring left ventricular volumes using 15 latex casts of excised human left ventricles. The casts were submerged in water to stimulate the endocardial left ventricular cavity interface in in vivo imaging conditions. Tomographic image sections perpendicular to the long axis of the cast were obtained, spanning each cast from apex to base. Simpson's rule was used to calculate the cast volumes. Correlation between the actual cast volumes (as measured by the displacement method) and the calculated volumes using MR imaging for the 15 casts was excellent. Our data demonstrate that MR imaging accurately measures cardiac chamber volumes in this in vitro model. 相似文献
36.
S Caserío C Gallego P Martin MT Moral CR Pallás A Galindo 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(10):1571-1577
Aim: To analyse the main prenatal and postnatal features of congenital chylothorax (CC), and the outcome including mid‐term follow‐up. Methods: We searched our databases for CC diagnosed between 1990 and 2006. Data of 29 cases were retrieved and analysed. Follow‐up until 3 years of age was available for all patients. Results: Most patients were diagnosed prenatally (94%) and most cases were complicated by foetal hydrops (66.7%). The overall survival rate at 3 years was 56%. A significantly poorer outcome was observed when foetal hydrops, preterm birth < 34 weeks, large effusions and/or early‐onset pneumothorax were present. An important but not significant improvement in the survival rate was observed through the study period; while in 1990–1998, the survival rate was 41.7%, from 1999 to 2006 it was 66.7% (p = 0.19). In the mid‐term follow‐up, we did not observe any recurrence of CC and most infants remain asymptomatic. However, 27% of survivors were diagnosed as having asthma in early infancy. Conclusion: CC still carries a significant risk of perinatal mortality. However, continuous advances in foetal and neonatal medicine are improving the prognosis of these patients, and nowadays most of them are likely to survive. Beyond the neonatal period, most survivors have an uneventful outcome. 相似文献
37.
In a previous study it was proved impossible to evaluate the validity of a system modified according to McGrath et al. for measuring postoperative pain in children. Three reasons were postulated for this result. The analgesics used did not modulate the pain in such a manner that the statistical analysis was effective; or the postoperative pain had an acute onset or fluctuated and the regular observations did not allow detection of the pain peaks; or the system used did not measure pain. Therefore, a new and different approach was adopted to evaluate the reliability and validity of a scoring system for the measurement of postoperative pain in small children. MATERIAL. Sixty children classed as ASA I and II and aged between 1 and 5 years were randomly allocated to 2 groups: one group received Tramadol (0.5 mg/kg) after the induction of anesthesia and the other group received placebo. Premedication and anesthesia were standardized. All indications were accepted except for urgent operations and painful diseases. For 1 h after the operation the children were continuously observed by an experienced pediatric anesthetist who did not know what drugs had been given. Every 15 min and when the observer was convinced that the children were in pain and needed analgesics the following items were scaled: wakefulness, wake-up reaction, crying, facial expression, position of the trunk, position of the legs, muscle tone, making contact, verbal communication on being asked about pain, special defense against stimuli and consolability. The items were included in a factor analysis (principal components). The number of the factors was detected using the Scree test. The only items accepted as reliable were those that had a substantial load of at least 0.4 at each measurement. The reliability coefficient was computed with the split-half technique (odd-even). The validity was estimated with a multifactorial analysis of variance with repeated measurements. When the observer was convinced that any child was in pain, Metamizol (15 mg/kg) was administered. Significance was assumed at P less than 0.05. The study was accepted by the ethical committee of the Ruhr University, Bochum. RESULTS. A replication verified the results of the previous study: the factor analysis resulted in a one-factorial solution. Of the 8 items (wakefulness, wake-up reactions, crying, position of the trunk, position of the legs, verbal communications on being asked about pain, special defense against stimuli) only 4 had a sufficiently substantial load on all measurements (crying, facial expression, position of the trunk and position of the legs). (ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
38.
Strangulation in child abuse: CT diagnosis 总被引:2,自引:0,他引:2
The central nervous system is commonly affected in child abuse. Between April 1985 and July 1986 three infants were identified in whom the primary mode of injury had been strangulation. In each case computed tomography (CT) demonstrated a large cerebral infarction confined to vascular territories associated with small subdural hematomas. There was no history or visible evidence of significant head trauma. Autopsy of one infant confirmed the presence of a hemispheric infarct, thin subdural hematoma, and an area of subintimal hemorrhage in the carotid artery ipsilateral to the infarct. The remaining two patients survived with residual hemiparesis. CT findings of a large cerebral infarction with an associated subdural hematoma in an infant without a history of a significant trauma should suggest the possibility of child abuse and may be the primary manifestation of abuse in some patients. 相似文献
39.
A retrospective study was performed to estimate the frequency of alloimmunization against red cell (RBC) antigens in a multiply transfused group. Patients (n = 186) were studied who had received at least six blood transfusions during a period of at least 3 months. Some 6944 units of blood were transfused. One hundred forty patients had hematologic disorders. The patients' sera were investigated every 3 months with indirect antiglobulin tests and enzyme-treated RBCs. Twenty-two patients (11.8%) made 33 antibodies. Seven patients made more than one antibody. Eight of the 22 patients (36.4%) made their first antibody before or at the 10th transfusion. The risk of immunization increased with the number of transfusions. Influence of gender and age was not demonstrable. Nor was a relationship demonstrated between blood transfusion reactions and RBC antibody formation; no delayed hemolytic transfusion reactions occurred. Anti-E was demonstrated in 12 patients and anti-K in 15. When the gene frequencies were taken into account, it appeared that anti-E was made by 11.5 percent of E-negative patients, most of whom were immunized after an estimated three transfusions with E-positive blood. Anti-K was made by 8.7 percent of the K-negative patients, after an estimated 2.1 units of K-positive blood. It might be desirable to match red cell units for the E and K antigens in patients at relatively high risk. These are primarily patients who have already formed an antibody and are going to receive many transfusions and women of childbearing age who are to receive more than 4 units of blood. 相似文献
40.