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   15521篇
  免费   1257篇
  国内免费   54篇
耳鼻咽喉   127篇
儿科学   414篇
妇产科学   278篇
基础医学   2204篇
口腔科学   298篇
临床医学   1907篇
内科学   3372篇
皮肤病学   147篇
神经病学   1217篇
特种医学   610篇
外科学   2215篇
综合类   305篇
一般理论   9篇
预防医学   1502篇
眼科学   206篇
药学   1175篇
中国医学   4篇
肿瘤学   842篇
  2023年   79篇
  2021年   342篇
  2020年   201篇
  2019年   318篇
  2018年   393篇
  2017年   291篇
  2016年   281篇
  2015年   302篇
  2014年   488篇
  2013年   653篇
  2012年   982篇
  2011年   1079篇
  2010年   566篇
  2009年   516篇
  2008年   902篇
  2007年   834篇
  2006年   826篇
  2005年   843篇
  2004年   816篇
  2003年   770篇
  2002年   681篇
  2001年   363篇
  2000年   325篇
  1999年   310篇
  1998年   180篇
  1997年   152篇
  1996年   115篇
  1995年   125篇
  1994年   110篇
  1993年   96篇
  1992年   236篇
  1991年   221篇
  1990年   239篇
  1989年   182篇
  1988年   159篇
  1987年   149篇
  1986年   156篇
  1985年   150篇
  1984年   141篇
  1983年   111篇
  1982年   84篇
  1981年   78篇
  1980年   51篇
  1979年   87篇
  1978年   71篇
  1977年   62篇
  1976年   57篇
  1974年   76篇
  1973年   51篇
  1970年   57篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Aims. Functional connectivity is providing new insights into the network nature of epilepsy with growing clinical applications. Our objective was to validate a novel magnetoencephalography‐based method to non‐invasively measure the epileptic network. Methods. We retrospectively identified pediatric and adult patients with refractory focal epilepsy who underwent pre‐surgical magnetoencephalography with subsequent intracranial electrographic monitoring. Magnetoencephalography tracings were visually reviewed, and interictal epileptiform discharges (“spikes”) were individually marked. We then evaluated differences in whole‐brain connectivity during brief epochs preceding the spikes and during the spikes using the Network‐Based Statistic to test differences at the network level. Results. In six patients with statistically‐significant network differences, we observed substantial overlap between the spike‐associated networks and electrographically active areas identified during intracranial monitoring (the spike‐associated network was 78% and 83% sensitive for intracranial electroencephalography‐defined regions in the irritative and seizure onset zones, respectively). Conclusion. These findings support the neurobiological validity of the spike‐associated network method. Assessment of spike‐associated networks has the potential to improve surgical planning in epilepsy surgery patients by identifying components of the epileptic network prior to implantation.  相似文献   
2.
3.
Choledochal cysts (CDCs) and biliary atresia (BA) are rare pediatric hepatobiliary anomalies that require surgical intervention due to increased risk of malignancy and liver failure, respectively. The underlying disease and operative procedures place patients at risk for long‐term complications, which may continue to affect them into adulthood. Lack of a transitional care model in the health‐care system potentiates the challenges they will face following aging out of their pediatric providers' care. We sought to elucidate the long‐term complications and challenges patients with CDCs and BA face, review the current literature regarding transitioning care, and propose guidelines aiding adult providers in continued care and surveillance of these patients. A literature review was performed to assess short‐term and long‐term complications after surgery and the current standards for transitioning care in patients with a history of CDCs and BA. While transitional programs exist for patients with other gastrointestinal diseases, there are few that focus on CDCs or BA. Generally, authors encourage medical record transmission from pediatric to adult providers, ensuring accuracy of information and compliance with treatment plans. Patients with CDCs are at risk for developing biliary malignancies, cholangitis, and anastomotic strictures after resection. Patients with BA develop progressive liver failure, necessitating transplantation. There are no consensus guidelines regarding timing of follow up for these patients. Based on the best available evidence, we propose a schema for long‐term surveillance.  相似文献   
4.
Background: Guidelines recommend primary prophylactic use of colony-stimulating factor (PP-CSF) when risk of febrile neutropenia (FN) – based on chemotherapy and patient risk factors – is high. Whether and how PP-CSF use may have changed over time (e.g. due to guideline revisions, increasing use of myelosuppressive regimens, controversy regarding inappropriate CSF use), and whether there has been a concomitant change in the incidence of FN, is unknown.

Methods: A retrospective cohort design and data from two US healthcare claims repositories were employed. The study population included patients who had non-metastatic cancer of the breast, colon/rectum, lung or ovaries, or non-Hodgkin’s lymphoma (NHL), and who received myelosuppressive chemotherapy regimens with an intermediate/high risk for FN. For each patient, the first cycle of the first course was characterized in terms of PP-CSF use and FN episodes. Crude incidence proportions for PP-CSF and FN during the first cycle were estimated by calendar quarter (2010–2016); multivariable logistic regression models were used to estimate quarter-specific adjusted mean probabilities of FN by PP-CSF use.

Results: The study population totaled 142,730 patients with breast cancer (61%), colorectal cancer (14%), NHL (11%), ovarian cancer (10%) or lung cancer (5%). PP-CSF use increased from 52% in 1Q2010 to 58% in 4Q2016; pegfilgrastim was the most commonly used agent (>96% across quarters). PP-CSF administration on the same day as chemotherapy ranged from 8 to 11% until 1Q2015, and increased to 64% by 4Q2016. Adjusted incidence proportions for FN in the first chemotherapy cycle ranged from 2.7% (95% CI: 2.3–3.0) to 3.7% (95% CI: 3.1–4.3) among those who did not receive PP-CSF, and was 2.6% (95% CI: 2.5–2.7) across quarters among those who received PP-CSF.

Conclusions: Although the use of PP-CSF is commonplace in current US clinical practice, underutilization in cancer patients receiving chemotherapy regimens with an intermediate/high risk for FN may still be an issue. Use of same-day PP-CSF increased markedly from the end of 2015, although this finding reflects (at least in part) increased uptake of pegfilgrastim delivered via an on-body injector as well as the recent change in clinical practice guidelines. Overall, patients receiving PP-CSF appear to have a lower risk of FN during the first cycle of chemotherapy.  相似文献   

5.
6.
Gonadoblastoma, a rare gonadal neoplasm, presents most frequently in phenotypic female or phenotypically male patients with dysgenetic gonads or undescended testes. To date, only 2 cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testes. Both of these patients presented with testicular masses and germ cell tumors. We report a case of a genotypically and phenotypically normal, fertile man with descended testes who on evaluation for chronic orchialgia had a gonadoblastoma unaccompanied by a germ cell neoplasm. The tumor was nonpalpable and was initially discovered on scrotal ultrasound.  相似文献   
7.
The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention.  相似文献   
8.
The traditional role of the high school based community community health nurse has changed considerably over recent decades. This article describes a qualitative study, in which nine community health nurses from eight different high schools completed a diary of the interventions and events during the course of two working days in order to identify the dimensions of their role. A short demographic questionnaire was also completed by the nurses and included two open-ended questions concerning their main professional issues and concerns. The researchers sought verification of the interpretation of the data through a focus group interview with the high school nurses. Data analysis indicated that the role of the high school community health nurses (CHN) consisted of seven categories. These were provider of clinical care, counsellor/ mediator, advocacy and support, liaison/referral, health promotion/education and resource agent, and professional management and research role. The findings highlight the complex and demanding aspects of the role of the high school nurse and articulate the importance of describing the contribution of such practitioners in to the promotion of health among adolescents.  相似文献   
9.
10.
Intraperitoneal (i.p.) injection of platelet activating factor (PAF) in guinea pigs caused a dose-related increase in the number of eosinophils recovered from bronchoalveolar lavage fluid (BALF). The prevalence of eosinophils in BALF had significantly increased within 1 hr of i.p. injection of PAF (10 micrograms/animal) and was maximal after 24 hr. Subcutaneous osmotic mini-pumps were used to administer drugs for 5 days prior to i.p. injection of PAF (10 micrograms/animal) and for the subsequent 24 hr. The percentage increase of eosinophils in BALF, due to PAF, was inhibited in animals treated with dexamethasone, aminophylline, cromoglycate, tranilast or ketotifen, but not in animals treated with oxatomide, azelastine, amlexanox, ibudilast or AA-861. These results suggest that inhibition of pulmonary eosinophilia may be a necessary property of prophylactic anti-asthma drugs and provide indirect evidence favoring a role for PAF in eosinophilia of asthma.  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