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   1284篇
  免费   104篇
  国内免费   2篇
耳鼻咽喉   15篇
儿科学   42篇
妇产科学   17篇
基础医学   150篇
口腔科学   35篇
临床医学   166篇
内科学   309篇
皮肤病学   42篇
神经病学   92篇
特种医学   38篇
外科学   155篇
综合类   17篇
预防医学   96篇
眼科学   10篇
药学   90篇
中国医学   4篇
肿瘤学   112篇
  2023年   35篇
  2022年   48篇
  2021年   66篇
  2020年   34篇
  2019年   34篇
  2018年   56篇
  2017年   43篇
  2016年   46篇
  2015年   36篇
  2014年   60篇
  2013年   64篇
  2012年   81篇
  2011年   114篇
  2010年   44篇
  2009年   57篇
  2008年   63篇
  2007年   85篇
  2006年   69篇
  2005年   60篇
  2004年   45篇
  2003年   41篇
  2002年   30篇
  2001年   17篇
  2000年   12篇
  1999年   15篇
  1998年   6篇
  1996年   5篇
  1995年   9篇
  1993年   4篇
  1992年   6篇
  1991年   6篇
  1990年   5篇
  1989年   5篇
  1987年   4篇
  1986年   7篇
  1985年   9篇
  1984年   4篇
  1980年   5篇
  1979年   5篇
  1977年   3篇
  1976年   3篇
  1975年   2篇
  1974年   4篇
  1972年   2篇
  1971年   4篇
  1970年   2篇
  1969年   7篇
  1968年   3篇
  1967年   5篇
  1966年   3篇
排序方式: 共有1390条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
In Japan, public funding for HPV vaccination began in 2010 for girls aged 13–16 years (birth cohort years 1994–1997) and women born in 1994 who turned 25 in 2019. We aimed to verify the long‐term effectiveness of the bivalent HPV vaccine in women aged 25 years. Subjects were women aged 25–26 years who underwent cervical cancer screening and HPV testing in Niigata from 2019 to 2020 (birth cohort years 1993–1994). Information on vaccination status and sexual behavior was obtained from a questionnaire and municipal records. We compared the HPV infection rates of the vaccinated and unvaccinated groups. Of the 429 registrants, 150 (35.0%) and 279 (65.0%) were vaccinated and unvaccinated, respectively. The average period from HPV vaccination to HPV testing was 102.7 months (8.6 years), with a median of 103 months (range 92–109 months). The HPV high‐risk infection rate was 21.3% (32/150) in the vaccinated group and 23.7% (66/279) in the unvaccinated group (P = 0.63). The HPV16/18 infection rate was 0% (0/150) in the vaccinated group and 5.4% (15/279) in the unvaccinated group, showing a significant difference (P = 0.0018), and the vaccine effectiveness was 100%. The cross‐protective type HPV31/45/52 infection rate in the vaccinated group was significantly lower than that in the unvaccinated group (3.3% vs. 10.0%, P = 0.013). There was no significant difference in the mean age at sexual debut and the number of previous sexual partners between the two groups. We have demonstrated the long‐term 9‐year effectiveness of the bivalent vaccine against HPV infection for the first time in Japan.  相似文献   
35.
Aflatoxin B1 (AFB1) is a potent mycotoxin and natural carcinogen. The primary producers of AFB1 are Aspergillus flavus and A. parasiticus. Sterigmatocystin (STC), another mycotoxin, shares its biosynthetic pathway with aflatoxins. While there are abundant data on the biological effects of AFB1, STC is not well characterised. According to published data, AFB1 is more harmful to biological systems than STC. It has been suggested that STC is about one-tenth as potent a mutagen as AFB1 as measured by the Ames test. In this research, the biological effects of S9 rat liver homogenate-activated and non-activated STC and AFB1 were compared using two different biomonitoring systems, SOS-Chromotest and a recently developed microinjection zebrafish embryo method. When comparing the treatments, activated STC caused the highest mortality and number of DNA strand breaks across all injected volumes. Based on the E. coli SOS-Chromotest, the two toxins exerted the same genotoxicities. Moreover, according to the newly developed zebrafish microinjection method, STC appeared more toxic than AFB1. The scarce information correlating AFB1 and STC toxicity suggests that AFB1 is a more potent genotoxin than STC. Our findings contradict this assumption and illustrate the need for more complex biomonitoring systems for mycotoxin risk assessment.  相似文献   
36.

Background

Interleukin (IL)-21 is a member of the type I cytokine family and plays a role in the pathogenesis of T helper type 2 allergic diseases. It has been reported that IL-21 expression is upregulated in acute skin lesions in atopic dermatitis (AD) patients; however, little is known about the serum IL-21 levels of AD patients. The aim of this study was to quantify the serum IL-21 levels of AD patients and to evaluate the relationships between the serum IL-21 level and disease severity, laboratory markers, and eruption type in AD patients.

Methods

We measured the serum IL-21 levels of adult AD patients and healthy control subjects using an enzyme-linked immunosorbent assay.

Results

The adult AD patients exhibited significantly higher serum IL-21 levels than the healthy control subjects. A comparison of the patients' serum IL-21 levels based on the clinical severity of their AD revealed that the patients with severe AD demonstrated significantly higher serum IL-21 levels than those with mild AD and the healthy control subjects. The serum IL-21 levels were significantly correlated with the skin severity score, and especially with the degree of acute lesions such as erythema and edema/papules. The serum IL-21 level was not associated with laboratory markers, such as the serum IgE level, the serum thymus and activation-related chemokine level, blood eosinophilia, and the serum lactate dehydrogenase level.

Conclusions

These results suggest that IL-21 might be involved in the pathogenesis of AD, especially the development of acute skin lesions.  相似文献   
37.
38.
Air microbubbles have been investigated recently at high magnetic field strength (2 Tesla or greater) as potential MR susceptibility contrast agents. We used a phantom to measure their susceptibility at 1.5 T to clarify their usefulness for this purpose. The phantom, filled with fresh Levovist suspension at 4 different doses (67 to 125 mg/mL), was continuously scanned with a gradient-echo technique at a temporal resolution of 10 s. The transverse relaxation increase (R2*) by microbubbles demonstrated a time course of exponential decay at each dose (time-constant, 39 to 57 s). The dependency of R2* on microbubble volume fraction was linear, with a slope of 89 s-1 per percentage microbubble volume fraction. Our study represents the first step towards applying microbubbles as susceptibility contrast agents at 1.5 T.  相似文献   
39.
Summary Eighty-nine knees with medial tibiofemoral and patellofemoral osteoarthritis were treated by high tibial osteotomy between 1972 and 1978, and 71 were followed up for at least 5 years, the average being 6 years and 9 months. There was no significant loss of motion as recorded before and after operation. In most patients pain decreased or disappeared, and walking ability was regained. Evaluation using the Japanese rating system showed that there were Good and Fair results in 86% of the cases. The average tibio-femoral angle in the Good group was 169±5°. The angles in the Poor group varied over a wide range. There were serious complications such as nonunion, malunion and infection in a few cases. In Group 1 (30 knees) high tibial osteotomy alone was performed. In Group 2 (41 knees) there were associated osteoarthritic changes in the patellofemoral joint and a high tibial osteotomy was combined with anterior displacement of the tibial tubercle (ventralisation). In comparison, Group 2 had better results with regard to both clinical and radiological evaluation.Read at the 16th Congress of the Societe Internationale de Chirurgie Orthopedique et de Traumatologie, London, England, 5th October, 1984  相似文献   
40.
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