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   126948篇
  免费   44500篇
  国内免费   606篇
耳鼻咽喉   2015篇
儿科学   5328篇
妇产科学   656篇
基础医学   25450篇
口腔科学   7063篇
临床医学   15594篇
内科学   28180篇
皮肤病学   4418篇
神经病学   19802篇
特种医学   6426篇
外国民族医学   2篇
外科学   16412篇
综合类   2926篇
现状与发展   2篇
一般理论   11篇
预防医学   9063篇
眼科学   1513篇
药学   11435篇
  14篇
中国医学   2878篇
肿瘤学   12866篇
  2024年   30篇
  2023年   254篇
  2022年   490篇
  2021年   2265篇
  2020年   6549篇
  2019年   11820篇
  2018年   11430篇
  2017年   12580篇
  2016年   11723篇
  2015年   11626篇
  2014年   11839篇
  2013年   12172篇
  2012年   11096篇
  2011年   11025篇
  2010年   9542篇
  2009年   6034篇
  2008年   6647篇
  2007年   5020篇
  2006年   4845篇
  2005年   4519篇
  2004年   4335篇
  2003年   4049篇
  2002年   3806篇
  2001年   2928篇
  2000年   1734篇
  1999年   592篇
  1998年   361篇
  1997年   309篇
  1996年   265篇
  1995年   270篇
  1994年   253篇
  1993年   220篇
  1992年   172篇
  1991年   186篇
  1990年   151篇
  1989年   113篇
  1988年   89篇
  1987年   74篇
  1986年   65篇
  1985年   81篇
  1984年   86篇
  1983年   47篇
  1982年   50篇
  1981年   39篇
  1980年   44篇
  1979年   32篇
  1978年   33篇
  1977年   41篇
  1976年   22篇
  1975年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

Objective

The aim of the study was to estimate the effect of the state-based reinsurance programs through the section 1332 State Innovation Waivers on health insurance marketplace premiums and insurer participation.

Data Source

2015 to 2022 Robert Wood Johnson Foundation Health Insurance Exchange Compare Datasets.

Study Design

An event study difference-in-differences (DD) model separately for each year of implementation and a synthetic control method (SCM) are used to estimate year-by-year effects following program implementation.

Data Collection/Extraction Methods

Not applicable.

Principal Findings

Reinsurance programs were associated with a decline in premiums in the first year of implementation by 10%–13%, 5%–19%, and 11%–17% for bronze, silver, and gold plans (p < 0.05). There is a trend of sustained declines especially for states that implemented their programs in 2019 and 2020. The SCM analyses suggest some effect heterogeneity across states but also premium declines across most states. There is no evidence that reinsurance programs affected insurer participation.

Conclusion

State-based reinsurance programs have the potential to improve the affordability of health insurance coverage. However, reinsurance programs do not appear to have had an effect on insurer participation, highlighting the need for policy makers to consider complementary strategies to encourage insurer participation.  相似文献   
2.
3.
4.
癫痫发作后状态(PIS)是指癫痫发作停止到恢复至发病前水平的异常状态,包括认知、运动、感觉、自主神经和精神行为等异常,症状多样,严重程度不一,持续数秒至数天不等,对患者的健康和生活质量产生很大影响。然而,目前国内外相关的研究较少,临床医生对此缺乏正确认识,容易误诊误治。本文将从PIS的定义、病理生理机制、临床表现、诊断和鉴别诊断、临床意义以及干预策略等进行综述,以提高临床医生的认识,并为今后临床研究提供参考。  相似文献   
5.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
6.
Although dose reduction of S‐1 is recommended for patients with impaired renal function, dose modification for such patients has not been prospectively evaluated. The aim of the present study was to investigate the pharmacokinetic parameters of 5‐fluorouracil, 5‐chloro‐2,4 dihydroxypyridine and oteracil potassium, and to review the recommended dose modification of S‐1 in patients with renal impairment. We classified patients receiving S‐1 into 4 groups according to their renal function, as measured using the Japanese estimated glomerular filtration rate (eGFR) equation. The daily S‐1 dose was adjusted based on the patient's eGFR and body surface area. Blood samples were collected for pharmacokinetic analysis. A total of 33 patients were enrolled and classified into 4 groups as follows: 10 patients in cohort 1 (eGFR ≥ 80 mL/min/1.73 m2), 10 patients in cohort 2 (eGFR = 50‐79 mL/min/1.73 m2), 10 patients in cohort 3 (eGFR = 30‐49 mL/min/1.73 m2), and 3 patients in cohort 4 (eGFR < 30 mL/min/1.73 m2). Those in cohorts 3 and 4 treated with an adjusted dose of S‐1 showed a similar area under the curve for 5‐fluorouracil (941.9 ± 275.6 and 1043.5 ± 224.8 ng/mL, respectively) compared with cohort 2 (1034.9 ± 414.3 ng/mL). Notably, while there was a statistically significant difference between cohort 1 (689.6 ± 208.8 ng/mL) and 2 (= 0.0474) treated with an equal dose of S‐1, there was no significant difference observed in the toxicity profiles of the cohorts. In conclusion, dose adjustment of S‐1 in patients with impaired renal function using eGFR is appropriate and safe.  相似文献   
7.
8.
9.
Among the chief limitations in achieving early detection and control of animal‐origin influenza of pandemic potential in high‐risk livestock populations is the existing lag time between sample collection and diagnostic result. Advances in molecular diagnostics are permitting deployment of affordable, rapid, highly sensitive, and specific point‐of‐capture assays, providing opportunities for targeted surveillance driving containment strategies with potentially compelling returns on investment. Interrupting disease transmission at source holds promise of disrupting cycles of animal‐origin influenza incursion to endemicity and limiting impact on animal production, food security, and public health. Adoption of new point‐of‐capture diagnostics should be undertaken in the context of promoting robust veterinary services systems and parallel support for operationalizing pre‐authorized plans and communication strategies that will ensure that the full potential of these new platforms is realized.  相似文献   
10.
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