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   346篇
  免费   16篇
  国内免费   18篇
耳鼻咽喉   7篇
儿科学   12篇
妇产科学   5篇
基础医学   21篇
口腔科学   20篇
临床医学   60篇
内科学   79篇
皮肤病学   8篇
神经病学   6篇
特种医学   48篇
外科学   16篇
综合类   13篇
预防医学   30篇
眼科学   3篇
药学   16篇
肿瘤学   36篇
  2023年   3篇
  2022年   5篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   5篇
  2017年   4篇
  2016年   2篇
  2015年   6篇
  2014年   5篇
  2013年   18篇
  2012年   13篇
  2011年   9篇
  2010年   16篇
  2009年   15篇
  2008年   13篇
  2007年   21篇
  2006年   10篇
  2005年   9篇
  2004年   12篇
  2003年   8篇
  2002年   6篇
  2001年   9篇
  2000年   6篇
  1999年   10篇
  1998年   14篇
  1997年   13篇
  1996年   16篇
  1995年   9篇
  1994年   13篇
  1993年   12篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1989年   8篇
  1988年   9篇
  1987年   7篇
  1986年   12篇
  1985年   12篇
  1984年   6篇
  1983年   5篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   1篇
  1978年   2篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
  1965年   1篇
排序方式: 共有380条查询结果,搜索用时 875 毫秒
91.
This study was undertaken to examine the association of specific medical and genitourinary conditions, medications, and functional disabilities with urinary incontinence (UI) in a nursing home (NH) population. Seventy-six incontinent and 38 continent patients in a Veterans Administration NH were studied. Incontinence was highly associated with each of the physical and mental functional disabilities we examined. However, with the exception of recurrent urinary tract infections and dementia, no specific clinical factors were significantly more common among incontinent than continent patients. Although precise causes for the UI were not determined, these data highlight the potential role of impairments of physical and/or mental function in the pathogenesis of UI among NH patients, and emphasize the need to address these impairments in future research on the assessment and treatment of UI in this population.  相似文献   
92.
Despite prophylaxis with immunosuppressive drugs, severe acute graft- versus-host disease (GVHD) remains a major cause of morbidity and mortality in patients transplanted with unmodified bone marrow (BM) grafts from HLA-identical siblings. Although T-cell depletion of the BM graft has evolved as the most effective method to prevent severe acute GVHD, this beneficial effect is counterbalanced by an increased rate of graft failure and relapse of the disease. To find an approach to T-cell depletion that may avoid these extreme risks, we gave BM recipients a fixed low number of 1 x 10(5) donor T cells per kilogram of recipient's body weight in the graft. This corresponds with 99% T-cell depletion and is achieved by the addition of T cells to the graft that was previously depleted of T cells. A total of 70 patients with hematologic malignancies or aplastic anemia, including 40 patients with standard- risk leukemias, received BM grafts, depleted of T cells according to this approach, from HLA-identical siblings. The preparative regimen consisted of cyclophosphamide and total body irradiation. The patients also received a short course of cyclosporine posttransplant. Graft failure did not occur. Acute GVHD, only grade I or II, was seen in 70% of the patients and was limited to the skin in all patients. Chronic GVHD occurred in 31% of the patients and, with the exception of 1 patient, was limited to the skin as well. Relapse occurred in 3 of 40 (8%) patients with standard-risk leukemias, resulting in a projected survival at 5 years of 80%. Patients with standard-risk diseases had a procedure-related mortality of 11%. Quality of life, determined 1 year after BM transplant, was good in almost all patients with standard-risk diseases. Thus, this approach of T-cell depletion may be an approach that avoids the development of severe acute and chronic GVHD without damaging the function or antileukemic effect of the graft and that has a low transplant-related morbidity and mortality.  相似文献   
93.
94.
A critical determinant of the efficacy of antineoplastic therapy is the response of malignant cells to DNA damage induced by anticancer agents. The p53 tumor-suppressor gene is a critical component of two distinct cellular responses to DNA damage, the induction of a reversible arrest at the G1/S cell cycle checkpoint, and the activation of apoptosis, a genetic program of autonomous cell death. Expression of the BCR-ABL chimeric gene produced by a balanced translocation in chronic myeloid leukemia, confers resistance to multiple genotoxic anticancer agents. BCR-ABL expression inhibits the apoptotic response to DNA damage without altering either the p53-dependent WAF1/CIP1-mediated G1 arrest or DNA repair. BCR-ABL-mediated inhibition of DNA damage-induced apoptosis is associated with a prolongation of cell cycle arrest at the G2/M restriction point; the delay of G2/M transition may allow time to repair and complete DNA replication and chromosomal segregation, thereby preventing a mitotic catastrophe. The inherent resistance of human cancers to genotoxic agents may result not only by the loss or inactivation of the wild-type p53 gene, but also by genetic alterations such as BCR-ABL that can delay G2/M transition after DNA damage.  相似文献   
95.
目的 体外比较曼氏血吸虫吡喹酮敏感株与抗性株成虫阶段对吡喹酮的反应性。方法 将各虫株成熟成虫分别培养于含吡喹酮分别为 3.2× 10 - 4、8× 10 - 4、1.6× 10 - 3m ol/ L的 MEM培养液中 ,37℃孵育 15、30、4 5、6 0、75 min后 ,分别在解剖镜下观察虫体的存活状况并计算存活率。结果 当孵育于含吡喹酮 3.2× 10 - 4m ol/ L的 MEM中 75 m in,敏感株与抗性株雌虫均能存活 ;但敏感株与抗性株雄虫的存活率仅为 11.5 % - 16 .0 %和 32 .7% - 36 .5 %。孵育于含吡喹酮 8× 10 - 4m ol/L 的 MEM中 15 min,抗性株雄虫与雌虫存活率为 4 8.3% - 5 0 .0 %和 5 7.9% - 6 3.6 % ;敏感株雄虫与雌虫的存活率为 2 2 .4 % - 2 5 .9%和 38.5 % - 4 8.3% ;75 min后 ,抗性株雄虫的存活率为 13.3%- 17.3% ,敏感株雄虫的存活率则为 0。孵育于含吡喹酮 1.6× 10 - 3m ol/ L 的 MEM中 15 min,抗性株雄虫与雌虫的存活率为 11.1% - 19.6 %和 2 7.5 % - 2 9.9% ;敏感株雄虫与雌虫的存活率均为 0。结论 将曼氏血吸虫吡喹酮抗性株和敏感株成虫孵育于含一定浓度吡喹酮的 MEM中不同时间后 ,抗性株的存活率高于敏感株 ;雌虫的存活率高于雄虫  相似文献   
96.
The mortality rate of elderly persons with heart failure is high despite the introduction of several effective therapeutic interventions during the past decade. The management of end of life, often associated with distressing symptoms and multiple hospitalizations, is a significant clinical problem. Skillful and effective management requires expert knowledge of the heart failure syndrome, but the critical dimension of care relates to detailed knowledge about a patient's comorbidities, extent of debility, values, and desires. Discussing end-of-life issues early in the course of illness is essential for determining the appropriate levels of intensity of care and for defining the circumstances in which patients wish to be hospitalized and when hospital care offers little potential for increased comfort or longevity. Early and repeated discussions are needed to consider matters such as living wills, do-not-resuscitate orders, and power of attorney. In light of the complexity of the health care system, including involvement of multiple caregivers, end-of-life issues are among the most demanding of a physician's time, but when end-of-life care is managed effectively, health care providers often are rewarded with the gratitude of patients and their families for minimizing suffering and providing optimal opportunities for patients to participate in the affairs of family and the community.  相似文献   
97.

Background and purpose:

It has been previously shown that high levels of nitric oxide (NO), from NO donors, kill neurones, but the mechanisms are unclear.

Experimental approach:

The effects of NO donors on the electrical properties of rat cultured cerebellar granule cells (CGC neurones) were investigated using the whole-cell patch-clamp technique.

Key results:

The NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NONOate or NOC-18) caused a rapid, persistent, but fully reversible inward current that was associated with an increase in baseline noise and was concentration dependent (100 µM–10 mM). The response to 3 mM DETA-NONOate was completely inhibited by 1 mM gadolinium, but not by NO scavengers (1 mM haemoglobin or 1 mM PTIO) or glutamate receptor antagonists (10 µM MK-801 or 60 µM CNQX). Application of decomposed 3 mM DETA-NONOate or 3 mM nitrite had no effect. In contrast, the NO donor S-nitrosoglutathione (GSNO) caused a rapid, persistent, but fully reversible outward current that was also concentration dependent (1–10 mM). The 3 mM GSNO response was unaltered by NO scavengers, glutamate antagonists or gadolinium, but was mimicked by decomposed 3 mM GSNO and 3 mM oxidized glutathione.

Conclusions and implications:

These results suggest that DETA-NONOate directly activates cation-selective channels, causing an inward current in CGCs. In contrast, GSNO causes an outward current in these cells. Some of the effects of these NO donors are independent of NO, and thus caution is required in interpreting results when using high concentrations of these compounds.  相似文献   
98.
99.
100.
A 62 year old Chinese woman presented 25 years after having both breasts augmented with paraffin injections. Development of paraffinomas and multiple episodes of paraffin-related mastitis eventually resulted in bilateral mastectomies. The unusual distribution of migrated calcified paraffinomas in the thoracic wall and its lymphatic system is documented on computed tomography.  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