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   218篇
  免费   27篇
耳鼻咽喉   1篇
儿科学   14篇
妇产科学   1篇
基础医学   29篇
口腔科学   6篇
临床医学   25篇
内科学   32篇
皮肤病学   2篇
神经病学   9篇
特种医学   58篇
外科学   25篇
综合类   10篇
预防医学   5篇
眼科学   5篇
药学   11篇
中国医学   1篇
肿瘤学   11篇
  2022年   4篇
  2021年   9篇
  2020年   2篇
  2019年   3篇
  2018年   6篇
  2017年   6篇
  2016年   7篇
  2015年   5篇
  2014年   12篇
  2013年   8篇
  2012年   2篇
  2011年   6篇
  2010年   7篇
  2009年   10篇
  2008年   3篇
  2007年   4篇
  2006年   9篇
  2005年   1篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  1999年   3篇
  1998年   6篇
  1997年   17篇
  1996年   12篇
  1995年   5篇
  1994年   5篇
  1993年   7篇
  1992年   3篇
  1991年   2篇
  1990年   4篇
  1989年   6篇
  1988年   6篇
  1987年   6篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1983年   4篇
  1982年   4篇
  1981年   6篇
  1980年   9篇
  1979年   1篇
  1978年   3篇
  1977年   6篇
  1976年   5篇
  1975年   3篇
  1974年   1篇
排序方式: 共有245条查询结果,搜索用时 15 毫秒
41.
Migraine headaches and depression often co-occur within individuals, and both syndromes run in families. However, knowledge about how these disorders relate across generations, as well as how migraine relates to other forms of psychopathology, is sparse. This study examined risk for migraine among female adolescent offspring of parents with different types of psychopathology. The sample was drawn from the Minnesota Twin Family Study, a community-based study of adolescents and their families ( n  = 674, 17-year-old female adolescents and their biological parents). Diagnoses of maternal, paternal and offspring major depression, antisocial behaviour, alcohol dependence and drug dependence were based on structured interviews. Migraine headaches in each family member were assessed via interviews with the mother. Parental depression, antisocial behaviour and drug dependence were associated with offspring migraine. These associations mostly remained significant even when parental migraine and the corresponding type of psychopathology in offspring were adjusted for. In contrast, there were no significant associations between parental psychopathology and offspring stomach problems, indicating that these associations did not extend to all offspring somatic symptoms. These results emphasize the need to look at antisocial behaviour and substance-related problems when examining associations between migraine and psychopathology, and indicate that more research on inter-generational links between migraine and psychopathology is needed.  相似文献   
42.
With the increase in the importance of using green energy sources to meet the world''s energy demands, attempts have been made to push perovskite solar cell technology toward industrialization all around the world. Improving the properties of perovskite materials as the heart of PSCs is one of the methods to fabricate favorable photovoltaic (PV) solar cells based on perovskites. Here, cadmium chloride (CdCl2) was used as an additive source for the perovskite precursor to improve its PV properties. Results indicated CdCl2 improves the perovskite growth and tailors its crystalline properties, suggesting boosted charge transport processes in the bulk and interfaces of the perovskite layer with electron–hole transport layers. Overall, by incorporation of 1.0% into the MAPbI3 layer, a maximum power conversion efficiency of 15.28% was recorded for perovskite-based solar cells, higher than the 12.17% for the control devices. The developed method not only improved the PV performance of devices but also boosted the stability behavior of solar cells due to the passivated domain boundaries and enhanced hydrophobicity in the CdCl2-based devices.

With the increase in the importance of using green energy sources to meet the world''s energy demands, attempts have been made to push perovskite solar cell technology toward industrialization all around the world.  相似文献   
43.
44.
45.
Abstract: The aim of this clinical study was to investigate the intensity of central pain in 18 patients. Each patient systematically recorded their own pain scores a total of 700 times (ie, 7 times/day for 100 consecutiv e days) using a standard four-point scale. In all 18 patients, the intensity of pain varied considerably (ranging in grade from no pain, mild pain, moderate pain to severe pain). During the 100 days, the average number of times (percentage of total) that each grade of pain intensity was scored was: no pain 7.4 (1.1%); mild pain 570.9 (81.6%); moderate pain 93.4 (13.3%), and severe pain 28.3 (4%). The difference between mild pain and moderate, severe, or no pain was significant. Thus, in our patient group the intensity of central pain was mostly mild, not severe. In contrast to other reports, our data suggest that to state that the intensity of central pain continues to be intolerable and severe throughout the day is an exaggeration. Among our 18 patients, an exacerbation of pain intensity was observed 507 times. Of these 507 events, 392 (77.3%) were due to specifiable factors and 115 (22.7%) were due to unknown factors. The specifiable factors could be attributed to: emotional factors 261 times (66.6%), somatic stimuli 44 times (11.2%), weather 38 times (9.7%), fatigue 29 times (7.4%), visceral activity 20 times (5.1%). Since there is no universally effective treatment for central pain, the strategy to manage central pain should primarily focus (if possible) on prevention of the exacerbating factors of central pain.  相似文献   
46.

Background

Breast cancer is the most common cancer in women characterized by a high variable clinical outcome among individuals treated with targeted therapies.

Patients and Methods

In this study, we performed a population-based approach intersecting high-throughput genotype data from Iraqi populations with publicly available pharmacogenomics information to estimate the frequency of genotypes correlated with responsiveness to breast cancer treatment thus improving the clinical management of this disease in an efficient and cost effective way. A total of 50 patients and 25 healthy controls were enrolled in our study. Genotyping of rs4880, rs4244285, and rs1801274 were examined in association with breast cancer in Iraqi women.

Results

We found that individuals carrying the CT genotype of rs4880 manifested an increased risk of breast cancer compared with those carrying the TT genotype (odds ratio [OR], 0.171; 95% confidence interval [CI], 0.053-0.551; P = .002). In the dominant model, we observed that the CT and CC genotype of rs4880 showed an increased risk of breast cancer compared with the TT genotype (OR, 0.248; 95% CI, 0.089-0.690; P = .006). Moreover, subjects with the GA genotype of rs4244285 presented a higher risk of breast cancer than the GG genotype (OR, 0.256; 95% CI, 0.066-0.987; P = .038) and dominant models (OR, 0.025; 95% CI, 0.054-0.775; P = .013).

Conclusion

The analysis revealed that rs1801274 showed linkage disequilibrium and decreased risk of breast cancer. In conclusion, our study suggests that rs4880 and rs4244285 polymorphisms play an important role in development of breast cancer in an Iraqi population, and no significant association was found between rs1801274 and the risk of breast cancer.  相似文献   
47.
The choice of a contrast agent for pulmonary angiography has important implications for patient comfort, image quality, and perhaps the safety of the procedure, particularly for "high-risk" patients. In a prospective study the nonionic, low-osmolality agent iopamidol eliminated the problem of image degradation due to coughing, and patients showed excellent tolerance for it. However, pressure measurements obtained within 3-5 minutes of injection of iopamidol and diatrizoate sodium meglumine 76% showed no significant difference in the hemodynamic effects of the two contrast agents, either for normotensive or for pulmonary hypertensive patients. Contrary to a common presumption, pulmonary hypertension by itself did not appear to increase the risk of pulmonary angiography. The theoretic presumption of greater hemodynamic stability with low-osmolality contrast agents was not clinically evident in this trial with iopamidol. At present, enhanced patient comfort and improved image quality remain the only confirmed bases for choosing this contrast agent for pulmonary angiography.  相似文献   
48.
SUMMARY A 23-year-old man, previously fit and well, presented with an atypical pneumonia, associated with microangiopathic anaemia, thrombocytopenia, rhabdomyolysis and renal impairment. Despite administration of intravenous fluids and antibiotics, his condition rapidly deteriorated, and the possibility of an aggressive connective tissue disorder was raised. Thus he was treated with high-dose oral steroids and plasma exchange until autoantibodies were shown to be negative. At this stage it transpired that the patient had swallowed water from a stream three weeks earlier, and leptospira antibody titres were subsequently found to be elevated. Antibiotics were continued, and after a protracted course he made a full recovery. Leptospirosis should be remembered as a rare cause of atypical pneumonia, particularly if there is associated hepatic or renal impairment.  相似文献   
49.
Gilbert syndrome is a common genetic disorder associated with mild unconjugated hyperbilirubinemia and no clinical illness. In contrast, Crigler-Najjar syndrome types I and II are rare genetic disorders associated with severe unconjugated hyperbilirubinemia and a life-long risk of kernicterus. Patients with Gilbert syndrome have low levels of a normal form of uridinediphosphoglucuronate glucuronosyltransferase because of a defect in the promoter region of both alleles, whereas patients with Crigler-Najjar syndrome are homozygous for a defect that yields an abnormal form of the enzyme that has limited or no activity. This case report describes a young adult with Crigler-Najjar syndrome type II in whom kernicterus developed after a laparoscopic cholecystectomy. The development of kernicterus was the result of a largely preventable series of events that lead to an increase in the free fraction of his serum bilirubin. Analysis of his genetic defect showed that he was homozygous for the mutation associated with Gilbert syndrome and heterozygous for a second mutation in the open reading frame of one allele of the bilirubin uridinediphosphoglucuronate glucuronosyltransferase gene. The combined defect leads to severe hyperbilirubinemia and shows how seemingly benign genetic defects, when combined, can cause serious clinical disease. (Gastroenterology 1997 Jun;112(6):2099-103)  相似文献   
50.
The interventricular septal wall thickness and motion was studied by echocardiography in 25 normal subjects and 43 patients with various cardiovascular disease proved at cardiac catheterization. The mean septal thickness was 7.2 mm. ± 0.7 S.D. in the normal subjects, 10,1 mm. ± 1.0 S.D. in 11 patients with left ventricular volume overload (P < 0.01), and a mean of 12.2 mm. in two patients with pure pressure overload of the left ventricle. Ten patients with coronary atherosclerotic heart disease (CAHD) had an average septal thickness of 9.2 mm. ± 1.1 S.D. and in five patients with congestive cardiomyopathy (CM) it was 9.1 mm. ± 0.8 S.D., and a mean of 17.8 mm. in four patients with IHSS (P < 0.01). In five patients with mitral stenosis the septal thickness did not differ from normal (mean 7.1 mm. ± 0.9 S.D.). Septal motion was correlated with angiographic ejection fraction, pattern of left ventricular wall motion, and coronary angiography. All patients with left ventricular disease and an abnormal septal motion invariably had significant left ventricular dysfunction at cardiac catheterization, particularly patients with CM or severe CAHD, although a normal septal motion does not exclude severe left ventricular dysfunction and hypokinesis.It is concluded that study of the interventricular septum by echocardiography provides a non-invasive technique with a high specificity but a lower sensitivity for identifying patients with left ventricular dysfunction.  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