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   7820篇
  免费   531篇
  国内免费   22篇
耳鼻咽喉   67篇
儿科学   212篇
妇产科学   190篇
基础医学   1159篇
口腔科学   109篇
临床医学   794篇
内科学   1920篇
皮肤病学   152篇
神经病学   647篇
特种医学   136篇
外科学   806篇
综合类   59篇
一般理论   3篇
预防医学   933篇
眼科学   106篇
药学   572篇
中国医学   37篇
肿瘤学   471篇
  2024年   10篇
  2023年   94篇
  2022年   140篇
  2021年   337篇
  2020年   189篇
  2019年   276篇
  2018年   302篇
  2017年   205篇
  2016年   180篇
  2015年   254篇
  2014年   307篇
  2013年   413篇
  2012年   633篇
  2011年   626篇
  2010年   395篇
  2009年   331篇
  2008年   513篇
  2007年   449篇
  2006年   457篇
  2005年   435篇
  2004年   359篇
  2003年   325篇
  2002年   309篇
  2001年   69篇
  2000年   74篇
  1999年   92篇
  1998年   59篇
  1997年   36篇
  1996年   46篇
  1995年   40篇
  1994年   35篇
  1993年   23篇
  1992年   37篇
  1991年   42篇
  1990年   41篇
  1989年   30篇
  1988年   37篇
  1987年   18篇
  1986年   18篇
  1985年   22篇
  1984年   8篇
  1983年   13篇
  1980年   6篇
  1976年   7篇
  1975年   6篇
  1974年   7篇
  1973年   9篇
  1971年   5篇
  1970年   5篇
  1967年   6篇
排序方式: 共有8373条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.

Background

Payers frequently rely on budget impact model (BIM) results to help determine drug coverage policy and its effect on their bottom line. It is unclear whether BIMs typically overestimate or underestimate real-world budget impact.

Objective

We examined how different modeling assumptions influenced the results of 6 BIMs from the Institute for Clinical and Economic Review (ICER).

Study Design

Retrospective analysis of pharmaceutical sales data.

Methods

From ICER reports issued before 2016, we collected estimates of 3 BIM outputs: aggregate therapy cost (ie, cost to treat the patient population with a particular therapy), therapy uptake, and price. We compared these against real-world estimates that we generated using drug sales data. We considered 2 classes of BIM estimates: those forecasting future uptake of new agents, which assumed “unmanaged uptake,” and those describing the contemporaneous market state (ie, estimates of current, managed uptake and budget impact for compounds already on the market).

Results

Differences between ICER's estimates and our own were largest for forecasted studies. Here, ICER's uptake estimates exceeded real-world estimates by factors ranging from 7.4 (sacubitril/valsartan) to 54 (hepatitis C treatments). The “unmanaged uptake” assumption (removed from ICER's approach in 2017) yields large deviations between BIM estimates and real-world consumption. Nevertheless, in some cases, ICER's BIMs that relied on current market estimates also deviated substantially from real-world sales data.

Conclusions

This study highlights challenges with forecasting budget impact. In particular, assumptions about uptake and data source selection can greatly influence the accuracy of results.  相似文献   
5.
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring tumour hypoxia.  相似文献   
6.
Toxicity testing of sediment samples from the Rio Santiago and its main tributaries was performed using a battery of tests that included the ECHA dipstick biocide monitor, the MetPad test, the lettuce seed germination and the root elongation test, the nematode test, spot plate test, and the SOS Chromotest. Assessment was carried out on organic extracts, pore water, and direct sediment. Results of bioassays showed toxicity sources from tributaries and canals flowing into the river and areas being degraded by insults from industrial spills. © by John Wiley & Sons, Inc.  相似文献   
7.
Abstract Pericardial tamponade remains a diagnostic challenge to the clinician especially when the patient is well compensated hemodynamically. We report an unusual case who sought medical help 1 month after having been stabbed in his chest. An investigation revealed a perforation of the myocardium and a pericardial tamponade. The patient survived thanks to a large organized clot that plugged the perforation. The patient was exposed to increased risk due to delayed onset, recognition, and therapy of the tamponade. Most reports on this subject deal with acute pericardial tamponade. Only few cases of delayed pericardial tamponade have been reported. A review of the relevant literature and the therapeutic approaches are discussed.  相似文献   
8.
A study of some antiparasitic properties of several homoallylamines and related tetrahydroquinolines and quinolines, previously described, was carried out using in vitro activity assays against the epimastigote form of Trypanosoma cruzi and against Trichomonas vaginalis. Unspecific cytotoxicity against murine macrophages was also studied. Although the antichagasic and trichomonacidal activities are not comparable to those of the standard drugs, nifurtimox and metronidazole, some of the compounds exhibit an interesting specific antiparasitic activity.  相似文献   
9.
To elucidate the possible role of vitamin E in the pathogenesis of Parkinson's disease (PD), we compared serum levels of alpha-tocopherol (vitamin E), measured by high-performance liquid chromatography, and the vitamin E/cholesterol ratio of 42 Parkinson's disease (PD) patients using their spouses as the control group. The serum levels of vitamin E did not differ significantly between the groups (13.84 +/- 0.56 micrograms/ml for PD and 14.80 +/- 0.57 micrograms/ml for controls), nor did the vitamin E/cholesterol ratio (0.64 +/- 0.03 for both groups). There was no influence of antiparkinsonian therapy on vitamin E or the vitamin E/cholesterol ratio. Serum levels of the vitamin E and vitamin E/cholesterol ratio did not correlate with age, age at onset, scores of the Unified Parkinson's Disease Rating Scale or the Hoehn and Yahr staging in the PD group. These results suggest that serum vitamin E concentrations do not play a role in the pathogenesis of PD.  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