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   14433篇
  免费   1086篇
  国内免费   42篇
耳鼻咽喉   152篇
儿科学   567篇
妇产科学   269篇
基础医学   1911篇
口腔科学   348篇
临床医学   1283篇
内科学   3703篇
皮肤病学   432篇
神经病学   1138篇
特种医学   287篇
外国民族医学   1篇
外科学   1821篇
综合类   79篇
一般理论   17篇
预防医学   1516篇
眼科学   227篇
药学   887篇
中国医学   63篇
肿瘤学   860篇
  2023年   120篇
  2022年   200篇
  2021年   511篇
  2020年   276篇
  2019年   473篇
  2018年   555篇
  2017年   372篇
  2016年   336篇
  2015年   427篇
  2014年   536篇
  2013年   722篇
  2012年   1034篇
  2011年   1078篇
  2010年   623篇
  2009年   541篇
  2008年   842篇
  2007年   825篇
  2006年   764篇
  2005年   791篇
  2004年   665篇
  2003年   657篇
  2002年   619篇
  2001年   333篇
  2000年   359篇
  1999年   274篇
  1998年   116篇
  1997年   82篇
  1996年   94篇
  1995年   78篇
  1994年   63篇
  1993年   43篇
  1992年   154篇
  1991年   126篇
  1990年   94篇
  1989年   92篇
  1988年   94篇
  1987年   84篇
  1986年   73篇
  1985年   67篇
  1984年   45篇
  1983年   34篇
  1981年   18篇
  1980年   17篇
  1979年   27篇
  1978年   15篇
  1977年   21篇
  1976年   18篇
  1973年   24篇
  1972年   17篇
  1971年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
We present a 6‐year‐old girl with skin hyperpigmentation, leukoplakia, and onychodystrophy, the classic mucocutaneous triad usually associated with dyskeratosis congenita. The patient also had premature graying of the hair, bone marrow failure, hepatitis, exudative retinopathy, osteopenia with multiple long bone fractures, and intracranial calcifications and brain cysts. Coats plus syndrome is a rare disease with a clinical and genetic overlap with dyskeratosis congenita. This disease is reviewed, with a focus on the pathogenesis of the genetic anomalies and its background as a telomere biology disorder.  相似文献   
4.
5.
6.
7.

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   
8.
OBJECTIVE: Alveolar distraction is a relatively novel procedure by which alveolar bone and underlying mucosa are regenerated. The low predictability of other vertical or horizontal bone regeneration methods has increased interest in this promising technique. This article was designed to review published clinical and experimental results on alveolar distraction, including basic research in other disciplines (maxillofacial and orthopedic distraction) related to or with influence on alveolar distraction. STUDY DESIGN: A review of the international literature was performed to summarize results of clinical and experimental studies on alveolar distraction and on distraction at other anatomical sites that contribute important findings on tissue biology, molecular mechanisms, and other factors that influence and participate in the alveolar distraction process. RESULTS: Research into alveolar distraction has addressed the latency phase, distraction phase, and consolidation phase, yielding highly variable results. Little experimental research has been carried out on this procedure, and most publications are clinical studies with a short follow-up period. Published studies have reported a high rate of complications, attributable to our current lack of understanding of the process. CONCLUSIONS: Definitive conclusions on alveolar distraction are hampered by the lack of clinical and experimental studies to date. Greater knowledge of the factors that influence the distraction process will lead to a more predictable and efficacious distraction technique and a better distractor design.  相似文献   
9.
Ureteral herniation is a rare entity. We report the first case of extraperitoneal ureteral herniation in a pediatric en bloc renal graft causing obstructive uropathy. A 70-year-old, obese patient with an en bloc renal transplant was found to have ureterohydronephrosis in the right renal graft on magnetic resonance imaging. Nephrostomy with insertion of a double-J catheter confirmed the presence of a ureteral loop within the inguinal tract. Surgery confirmed herniation of the ureter through the internal inguinal ring, crossing over the spermatic cord. We performed release, resection, ureteral reimplantation and hernioplasty. Four months later, renal function was normal and urinary tract dilation had diminished. This case illustrates an unusual cause of obstructive uropathy in a transplanted kidney. Apart from obesity, two other factors may have contributed to its development: presence of a redundant ureter, and the fact that the ureter had been placed over, rather than under, the spermatic cord.  相似文献   
10.
The effect of zinc supplementation on the metabolism of tryptophan conversion to niacin was studied in 14 alcoholic patients with pellagra and in 7 male control subjects aged 21-45 y. The pellagrins received chemically defined diets based on crystalline amino acids through an enteral tube for 7 d. Patients were divided into two groups (A and B), both receiving a diet from which tryptophan, Zn, and niacin were excluded. Patients in group B, however, received 220 mg Zn sulfate orally. Upon admission the pellagra patients had low plasma Zn levels and low urinary excretion values of N'methylnicotinamide (N'MN) and N'methyl-2-pyridone-5-carboxamide (2-PYR) in relation to the control subjects (p less than 0.01). During the experimental period there was an increase in plasma Zn levels (p less than 0.005) and in urinary N'MN (p less than 0.05) and 2-PYR (p less than 0.05) excretion in the patients receiving Zn supplementation (group B). These results suggest that Zn interacts with niacin metabolism in alcoholic patients with pellagra through a probable mediation by vitamin B-6.  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