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   1067篇
  免费   55篇
  国内免费   2篇
耳鼻咽喉   31篇
儿科学   102篇
妇产科学   9篇
基础医学   126篇
口腔科学   47篇
临床医学   50篇
内科学   201篇
皮肤病学   22篇
神经病学   52篇
特种医学   30篇
外科学   178篇
综合类   32篇
预防医学   32篇
眼科学   36篇
药学   80篇
中国医学   2篇
肿瘤学   94篇
  2023年   8篇
  2022年   11篇
  2021年   38篇
  2020年   11篇
  2019年   26篇
  2018年   34篇
  2017年   22篇
  2016年   24篇
  2015年   21篇
  2014年   28篇
  2013年   42篇
  2012年   64篇
  2011年   106篇
  2010年   42篇
  2009年   27篇
  2008年   66篇
  2007年   61篇
  2006年   51篇
  2005年   42篇
  2004年   44篇
  2003年   45篇
  2002年   46篇
  2001年   30篇
  2000年   30篇
  1999年   32篇
  1998年   8篇
  1997年   11篇
  1996年   4篇
  1995年   4篇
  1993年   6篇
  1992年   16篇
  1991年   12篇
  1990年   7篇
  1989年   6篇
  1988年   9篇
  1987年   16篇
  1986年   11篇
  1985年   9篇
  1984年   5篇
  1983年   3篇
  1982年   5篇
  1981年   4篇
  1980年   2篇
  1979年   8篇
  1978年   6篇
  1977年   3篇
  1974年   2篇
  1973年   3篇
  1972年   2篇
  1971年   4篇
排序方式: 共有1124条查询结果,搜索用时 15 毫秒
111.
After allogeneic stem cell transplantation (SCT), T lymphocyte function is reestablished from the donor's postthymic T cells and through thymic T-cell neogenesis. The immune repertoire and its relation to that of the donor have not been characterized in detail in long-term adult SCT survivors. We studied 21 healthy patients in their second decade after a myeloablative SCT for hematologic malignancy (median follow-up, 12 years). Immune profiles were compared with donor samples cryopreserved at transplant and beyond 10 years from SCT. Only one recipient was on continuing immunosuppression. Compared with the donor at transplant, there was no significant difference in CD4, CD8, natural killer, and B-cell blood counts. However, compared with donors, recipients had significantly fewer naive T cells, lower T-cell receptor excision circle levels, fewer CD4 central memory cells, more effector CD8(+) cells, and more regulatory T cells. TCR repertoire analysis showed no significant difference in complexity of TCRVβ spectratype between recipients and donors, although spectratype profiles had diverged with both gain and loss of donor repertoire peaks in the recipient. In conclusion, long-term allogeneic SCT survivors have subtle defects in their immune profile consistent with defective thymic function but compatible with normal health. This study is registered at http://www.clinicaltrials.gov as NCT00106925.  相似文献   
112.
Primary cutaneous mucormycosis is uncommon and is extremely rare in immunocompetent young individuals. Here we report a case of necrotising fasciitis due to mucormycosis in an immunocompetent young individual following minor trauma. Mucormycosis must be suspected in any wound that is worsening despite appropriate treatment even in immunocompetent individuals.  相似文献   
113.
Infections with Entamoeba histolytica are seen worldwide and are more prevalent in the tropics. About 90% of infections are asymptomatic, and the remaining 10% produce a spectrum of clinical syndromes, ranging from dysentery to abscesses of the liver or other organs. Extra-intestinal infection by E. histolytica most often involves liver. Pleuro-pulmonary involvement, seen as the second most common extra-intestinal pattern of infection, is frequently associated with amebic liver abscess. Pulmonary amebiasis occurs in about 2-3% of patients with invasive amebiasis. We report herein the case of a 45-year-old male presenting with hepato-pulmonary amebiasis. The diagnosis was established from direct examination of sputum, in which trophozoites of E. histolytica were detected, and by serology. Following treatment with metronidazole and chloroquine, the clinical evolution improved significantly. On regular follow-up visits, the patient was asymptomatic. This case report reiterates the need for collaboration between clinicians and microbiologists for timely diagnosis of such infections.  相似文献   
114.
A rare association of tuberculous liver abscesses with bilateral transudative pleural effusion, ascites and venous thromboembolism in a 22-year-male is reported. While the BACTEC culture and polymerase chain reaction of the aspirate from liver abscess were positive for mycobacterium tuberculosis, all the reports of pleural fluid and ascitic fluid were negative. The bilateral pleural effusion and the ascites may be due to a non-tuberculous cause like hypoalbuminaemia. The finding of venous thromboembolism was incidental.  相似文献   
115.

Background

Gastroesophageal reflux disease (GERD) and its complications are thought to be infrequent in India; there are no data from India on the prevalence of and risk factors for GERD. The Indian Society of Gastroenterology formed a task force aiming to study: (a) the frequency and profile of GERD in India, (b) factors including diet associated with GERD.

Methods

In this prospective, multi-center (12 centers) study, data were obtained using a questionnaire from 3224 subjects regarding the frequency, severity and duration of heartburn, regurgitation and other symptoms of GERD. Data were also obtained regarding their dietary habits, addictions, and lifestyle, and whether any of these were related or had been altered because of symptoms. Data were analyzed using univariate and multivariate methods.

Results

Two hundred and forty-five (7.6%) of 3224 subjects had heartburn and/or regurgitation at least once a week. On univariate analysis, older age (OR 1.012; 95% CI 1.003–1.021), consumption of non-vegetarian and fried foods, aerated drinks, tea/coffee were associated with GERD. Frequency of smoking was similar among subjects with or without GERD. Body mass index (BMI) was similar in subjects with and without GERD. On multivariate analysis, consumption of non-vegetarian food was independently associated with GERD symptoms. Overlap with symptoms of irritable bowel syndrome was not uncommon; 21% reported difficulty in passage of stool and 9% had mucus in stools. About 25% of patients had consulted a doctor previously for their gastrointestinal symptoms.

Conclusion

7.6% of Indian subjects have significant GERD symptoms. Consumption of non-vegetarian foods was an independent predictor of GERD. BMI was comparable among subjects with or without GERD.  相似文献   
116.
The aim of this study was to analyze sleep complaints in patients with systemic lupus erythematosus (SLE) and to determine its prevalence and associations. Fifty outpatients with SLE and an equal number of age- and sex-matched controls were included in the study. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) in both cases and controls. Depressed mood, functional disability and pain severity were assessed in patients using standardized questionnaires. Disease severity, cumulative damage and presence of fibromyalgia were determined by clinical examination. Bivariate associations between sleep quality and disease-related variables as well as demographic variables were calculated. A series of hierarchical regression analyses were computed to determine the independent determinant of sleep quality. PSQI scores were significantly higher in patients with SLE. Prevalence of sleep disturbance was 62%. Functional disability, disease activity and depressed mood correlated positively with sleep disturbances. 36% of the patients satisfied ACR criteria for fibromyalgia. In multiple regression analyses disease activity was found to be an independent determinant of sleep quality. The prevalence of poor sleep quality in patients with SLE was higher than it is generally perceived to be. Functional disability, disease activity and depressed mood contributed significantly to sleep disturbances in SLE.  相似文献   
117.

Background

The inclusion of hepatitis B core antibody-positive (HBcAb+) liver donors is a strategy utilized to increase organ availability. This study examined HBcAb+ transplantation practices to identify specific factors influencing outcomes.

Methods

Twenty-five HBcAb+ liver transplants were identified retrospectively among 868 adult transplants performed between 1 January 1997 and 31 December 2009. Twelve (48%) recipients had hepatitis C and five (20%) had hepatitis B. Patient and donor demographics, preoperative morbidity, transplant data and outcomes were examined. Statistical analysis was completed using Student''s t-test or the Kaplan–Meier method. A P-value of <0.05 was considered significant.

Results

There was no difference in age, body mass index or comorbidities between HBcAb+ liver recipients and control subjects. Model for End-stage Liver Disease (MELD) scores of >30 were significantly more frequent in HBcAb+ liver recipients (32% vs. 15%; P = 0.04). All patients received immunoglobulin and longterm antiviral therapy as prophylaxis against graft hepatitis B resurgence. No patients who received HBcAb+ livers developed hepatitis B infection on follow-up. Overall survival at 30 days, 1 year and 5 years in HBcAb+ liver recipients was 92%, 74% and 74%, respectively, compared with 96%, 89% and 76%, respectively, in the control group (P = not significant, log-rank test). All except one of the deaths in the HBcAb+ liver recipient group occurred within 90 days postoperatively and in patients with MELD scores >30.

Conclusions

The practice of transplanting HBcAb+ grafts incurs low risk for infection using current methods of prophylaxis. The highest mortality risk was in the early postoperative period, specifically in patients with very high MELD scores. This probably reflects the practice of using positive serology grafts in emergent situations.  相似文献   
118.
Acute attacks of adenolymphangitis (ADL) contribute significantly to the morbidity seen in cases of filarial lymphoedema. Such cases are now being treated with multiple courses of the antifilarial drug diethylcarbamazine (DEC), either alone or in combination with antibiotics or anti-inflammatory drugs, based on anecdotal experience. In this, the first double-blind, placebo-controlled study, 150 patients with lymphoedema caused by brugian filariasis, each of whom recalled two or more ADL attacks in the previous year, were enrolled on a comprehensive foot-care programme. Each was also randomly allocated to one of the following five daily regimens (30 patients/regimen) for 1 year: 800 mg oral penicillin; 1 mg DEC/kg; 800 mg oral penicillin plus 1 mg DEC/kg; local antibiotics; or placebo. Each patient was followed up for another year. For each regimen group (including the placebo group), the number of ADL attacks in the treatment year was significantly less than that in the year prior to treatment (P < 0.001). Although, in all but the placebo group, there was a slight increase in the number of episodes in the follow-up year compared with the treatment year, the increase was only significant in the two groups given penicillin. Of all the treatments tested therefore, foot care seems to play the most important role in the prevention of ADL attacks. Additional benefit may accrue from local or systemic antibiotic use in those with high grades of oedema, but antifilarials have no place in the prevention of ADL attacks in an individual patient. These observations should help in the rational management and prevention of ADL attacks in filarial lymphoedema, so that the progression of the disease may be halted and morbidity reduced.  相似文献   
119.

Background

The objective of this study is to evaluate use of the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) online risk calculator for estimating common outcomes after operations for gallbladder cancer and extrahepatic cholangiocarcinoma.

Methods

Subjects from the United States Extrahepatic Biliary Malignancy Consortium (USE-BMC) who underwent operation between January 1, 2000 and December 31, 2014 at 10 academic medical centers were included in this study. Calculator estimates of risk were compared to actual outcomes.

Results

The majority of patients underwent partial or major hepatectomy, Whipple procedures or extrahepatic bile duct resection. For the entire cohort, c-statistics for surgical site infection (0.635), reoperation (0.680) and readmission (0.565) were less than 0.7. The c-statistic for death was 0.740. For all outcomes the actual proportion of patients experiencing an event was much higher than the median predicted risk of that event. Similarly, the group of patients who experienced an outcome did have higher median predicted risk than those who did not.

Conclusions

The ACS NSQIP risk calculator is easy to use but requires further modifications to more accurately estimate outcomes for some patient populations and operations for which validation studies show suboptimal performance.  相似文献   
120.
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