全文获取类型
收费全文 | 821篇 |
免费 | 37篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 47篇 |
妇产科学 | 15篇 |
基础医学 | 68篇 |
口腔科学 | 7篇 |
临床医学 | 76篇 |
内科学 | 110篇 |
皮肤病学 | 3篇 |
神经病学 | 130篇 |
特种医学 | 82篇 |
外科学 | 92篇 |
综合类 | 18篇 |
预防医学 | 85篇 |
眼科学 | 8篇 |
药学 | 39篇 |
中国医学 | 2篇 |
肿瘤学 | 82篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 12篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 18篇 |
2012年 | 40篇 |
2011年 | 37篇 |
2010年 | 20篇 |
2009年 | 47篇 |
2008年 | 29篇 |
2007年 | 47篇 |
2006年 | 51篇 |
2005年 | 32篇 |
2004年 | 38篇 |
2003年 | 30篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 29篇 |
1999年 | 25篇 |
1998年 | 9篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 23篇 |
1991年 | 21篇 |
1990年 | 22篇 |
1989年 | 19篇 |
1988年 | 21篇 |
1987年 | 16篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1970年 | 4篇 |
1965年 | 2篇 |
排序方式: 共有866条查询结果,搜索用时 31 毫秒
1.
2.
3.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
4.
A reduction of natural killer (NK) cell activity has been found in hospitalized patients with major depressive disorder. To examine whether a reduction of NK activity is found in other psychiatric patients or related to the nonspecific effects of hospitalization, NK cell cytotoxicity was compared in hospitalized depressed patients, schizophrenic inpatients, and two groups of controls separately age matched to each patient group. NK activity was significantly (p less than 0.01) lower in depressed inpatients than control subjects. However, in the hospitalized schizophrenic patients values of natural cytotoxicity did not differ from controls. These findings suggest that reduced NK cytotoxicity in depression is independent of the effects of hospitalization. 相似文献
5.
An institution-wide program for residents impaired by alcohol, other drugs, or emotional problems was established in 1983 at the Medical College of Wisconsin Affiliated Hospitals. The goal of the program was to help impaired house staff members to continue their training in a nonpunitive environment. An approach to reviewing allegations of impairment and a legal agreement between the hospital and the recovering resident were implemented. Because no residents were reported for impairment during its first two years, the program's emphasis was shifted from an investigative to an educational, assistive role. Major problems in carrying out the program have been the program's lack of authority to ensure cooperation by program directors and by impaired residents; a widespread unfamiliarity with intervention procedures despite efforts to inform residents, their spouses, faculty members, and administrators about the program; and misconceptions that the program is punitive. Further impediments are lack of a budget to provide educational activities, inadequate socializing between the faculty and the house staff that would enable faculty members to recognize early signs of impairment; and inadequate health insurance coverage for long-term treatment. 相似文献
6.
It has been known for some time that patients with Parkinson's disease (PD) have difficulty executing simultaneous motor acts, yet the pathophysiology underlying this impairment remains uncertain. We examined the possibility that these dual-task deficits stem from defective sensorimotor mechanisms producing interference between the motor programs underlying the two tasks. Patients with PD and normal control subjects were tested on their ability to maintain steady-state force with one hand while performing a force-reaction time task with the other hand. Although performance was worse on the dual-task than on the single-task condition for both subject groups, only the patients with PD demonstrated significant interference between the two tasks. The interference across tasks improved in 87% of the patients with PD when tested after treatment with carbidopa/levodopa (Sinemet). These findings support the contention that, in patients with PD, disturbances in the execution of simultaneous motor performance may be due to sensorimotor disinhibition. 相似文献
7.
Dr. Carsten Herskind Katharina Fleckenstein Jens Lohr Chuan-Yuan Li Frederik Wenz Frank Lohr 《Strahlentherapie und Onkologie》2004,180(4):187-193
BACKGROUND: During the last 2 decades, cytokines such as interferons (IFN) have been used to modulate tumor response in radiotherapy. Initially, the focus was on antiviral and radiosensitizing effects of interferons but increasingly, the function of interferons and interleukins (IL) within the immune response to tumor cells is becoming important. METHOD: The cellular immune response toward tumor cells is reviewed. The role of cytokines in antigen presentation and activation of effector cells and their interactions with radiation are described. Preclinical strategies of the antitumor action of cytokines are presented and discussed based on the induction of IFN-gamma by IL-12. RESULTS: Recent advances in immunology have demonstrated the importance of local interactions between antigen-presenting cells (APC) and effector cells such as natural killer (NK) cells and T-lymphocytes for an effective immune reaction against tumors. Interferons stimulate such interactions, while IL-2 plays a central role in the activation of NK cells and T-lymphocytes. The interactions between APC and effector cells are suppressed by many tumors but can be stimulated by irradiation. Since systemic application of interferons is quite toxic, present strategies aim at local expression, e. g., the induction of IFN-gamma expression in Th1 cells by IL-12. CONCLUSION: The improved understanding of immunologic mechanisms has emphasized the role of the cytokine network in the interaction between tumor cells and effector cells such as NK cells and T-lymphocytes. This opens new possibilities for the application of cytokines as biological response modifiers, which may eventually help widening the therapeutic window in radiotherapy. 相似文献
8.
9.
Eleven "pure" borderlines, ten borderlines with depression, 16 "pure" depressives, and 31 normal subjects were compared on a number of standardized inventories of anxiety. While patient groups experienced more anxiety of all types than did normals, borderlines did not emerge as more anxious than other patient groups. Qualitative differences in the anxiety experienced by borderlines and nonborderlines are discussed. 相似文献
10.
Using hospital discharge abstract data for fiscal year 1984 for all acute care hospitals treating Medicare patients (age greater than or equal to 65), we measured four mortality rates: inpatient deaths, deaths within 30 days after discharge, and deaths within two fixed periods following admission (30 days, and the 95th percentile length of stay for each condition). The metric of interest was the probability that a hospital would have as many deaths as it did (taking age, race, and sex into account). Differences among hospitals in inpatient death rates were large and significant (p less than .05) for 22 of 48 specific conditions studied and for all conditions together; among these 22 "high-variation" conditions, medical conditions accounted for far more deaths than did surgical conditions. We compared pairs of conditions in terms of hospital rankings by probability of observed numbers of inpatient deaths; we found relatively low correlations (Spearman correlation coefficients of 0.3 or lower) for most comparisons except between a few surgical conditions. When we compared different pairs of the four death measures on their rankings of hospitals by probabilities of the observed numbers of deaths, the correlations were moderate to high (Spearman correlation coefficients of 0.54 to 0.99). Hospitals with low probabilities of the number of observed deaths were not distributed randomly geographically; a small number of states had significantly more than their share of these hospitals (p less than .01). Information from hospital discharge abstract data is insufficient to determine the extent to which differences in severity of illness or quality of care account for this marked variability, so data on hospital death rates cannot now be used to draw inferences about quality of care. The magnitude of variability in death rates and the geographic clustering of facilities with low probabilities, however, both argue for further study of hospital death rates. These data may prove most useful as a screening mechanism to identify patterns of potentially poor quality of care. Careful choice of the mortality measure used is needed, however, to maximize the probability of identifying those hospitals, and only those hospitals, warranting more in-depth review. 相似文献