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   669篇
  免费   38篇
耳鼻咽喉   1篇
儿科学   28篇
妇产科学   6篇
基础医学   53篇
口腔科学   14篇
临床医学   92篇
内科学   207篇
皮肤病学   14篇
神经病学   19篇
特种医学   132篇
外科学   17篇
综合类   13篇
预防医学   64篇
眼科学   2篇
药学   21篇
肿瘤学   24篇
  2023年   2篇
  2022年   5篇
  2021年   12篇
  2020年   3篇
  2019年   6篇
  2018年   10篇
  2017年   3篇
  2016年   7篇
  2015年   14篇
  2014年   9篇
  2013年   29篇
  2012年   7篇
  2011年   10篇
  2010年   23篇
  2009年   27篇
  2008年   11篇
  2007年   11篇
  2006年   13篇
  2005年   18篇
  2004年   18篇
  2003年   16篇
  2002年   13篇
  2001年   23篇
  2000年   12篇
  1999年   14篇
  1998年   33篇
  1997年   33篇
  1996年   37篇
  1995年   28篇
  1994年   26篇
  1993年   21篇
  1992年   15篇
  1991年   14篇
  1990年   11篇
  1989年   18篇
  1988年   17篇
  1987年   14篇
  1986年   12篇
  1985年   14篇
  1984年   7篇
  1983年   12篇
  1982年   9篇
  1981年   12篇
  1980年   3篇
  1979年   7篇
  1978年   8篇
  1977年   15篇
  1976年   8篇
  1975年   13篇
  1968年   2篇
排序方式: 共有707条查询结果,搜索用时 15 毫秒
31.
32.
Reeve  AE; Morris  CM; Fitzgerald  PH 《Blood》1988,72(1):24-28
A 45-year-old male patient with Ph-negative chronic myeloid leukemia (CML) had rearranged bcr-3' and bcr-5' gene regions in Southern blot studies when leukemia was diagnosed. During development of terminal blast crisis, successive blood samples showed a progressive decrease in the amount of germline bcr DNA and its complete loss by full blast crisis. There were also increased amounts of rearranged bcr DNA consistent with acquired homozygosity. A similar result was obtained with an IgV lambda probe and indicated homozygosity of a significant part of chromosome 22. The bcr-abl gene complex behaves as a somatic dominant in CML, and we suggest that its acquired homozygosity is a mechanism of bcr-abl amplification similar to duplication of the Ph chromosome commonly found in the blast crisis of CML.  相似文献   
33.
Morrison  AE; Ludlam  CA; Kessler  C 《Blood》1993,81(6):1513-1520
Data have been collected from 47 centers in Europe and North America on the treatment with porcine factor VIII concentrate of 74 acute bleeding episodes in 65 patients with acquired hemophilia. The median initial anti-human factor VIII auto-antibody inhibitor level was 38 Bethesda unit (BU)/mL (range 1.2 to 1,024) whereas that against porcine was 1 BU/mL (range 0 to 15). The mean initial dose of porcine factor VIII infused was 84 IU/kg, which increased the plasma factor VIII:C activity by 0.85 IU/mL. Therapy was continued for a mean of 8.5 days during which time the average number of infusions was 11. Objective clinical responses were rated as good or excellent in 78% of recipients. Side effects were uncommon; only one patient experienced a severe anaphylactic reaction necessitating the discontinuation of porcine FVIII therapy. After therapy, no increase in the median level of anti- human FVIII or anti-porcine antibody was noted in the group as a whole, although 13 patients showed individual increases in either anti-human or anti-porcine antibody levels or both of more than 10 BU/mL. Of the 7 patients who subsequently rebled, 5 were successfully re-treated and 2 did not respond to further porcine factor VIII treatment. Porcine factor VIII is safe and clinically effective treatment for bleeding episodes associated with acquired hemophilia and should be considered as first-line therapy for patients whose acquired anti-factor VIII:C antibody cross-reacts with porcine factor VIII:C at low levels.  相似文献   
34.
35.
Background Perceived age is important to women and is a primary driver for topical product use and facial cosmetic surgery. Changes in facial features and biophysical skin parameters with chronological age and their associations with perceived age have not been described in Asian populations. Objective To investigate the relationship between biophysical properties of the skin, visual features of skin ageing and perceived facial age in Chinese women. Methods Facial photographs were collected of 250 Chinese women, aged 25–70 years in Shanghai, China. The perceived facial age was determined and related to the chronological age for each participant and to a range of visual assessments of skin appearance and objective biophysical measurements of the skin. The profile of changes in these parameters with age was investigated together with the differences in those parameters for women judged to look younger than their chronological age and those judged to look older than their chronological age. Results Large discrepancies in perceived age (up to 29 years) were found in women of the same chronological age. Each objective skin measure and visual assessment parameter had a stronger correlation with perceived age than with chronological age. The strongest relationships to perceived age were for wrinkles and hyperpigmentation. Skin colour, hydration and trans‐epidermal water loss (TEWL) had weaker associations with perceived age. Women judged to look older than their chronological age had significantly higher scores than those judged to look younger for coarse wrinkles and hyperpigmentation across all age groups. The appearance differences between these groups were evident in composite facial images of the same average chronological age. Conclusions We have identified the skin attributes which differ with perceived age in Chinese women. Perceived age is a better measure of the biological age of facial skin than is chronological age in this population.  相似文献   
36.
Aim: The aim of the student is to assess whether adolescents with type 1 diabetes mellitus (T1DM) in Italy differ from their healthy peers in regard to risky behaviour. Methods: Data were collected from 215 patients, aged 14 ± 2 years with a mean disease duration of 7 ± 5 years. The control group was comprised of 464 healthy adolescents recruited among high school students. Each patient completed an anonymous confidential questionnaire to determine the prevalence of sexual behaviour, alcohol and tobacco consumption, illicit drug use, and, among patients with diabetes and frequency of mismanagement related to diabetes care. Results: Compared with controls, subjects with diabetes showed a similar rate of sexual intercourse among males and lower rates among females (34.8% vs 35.5%, p NS and 29.4% vs 41.4%, p < 0.05, respectively). Males in the diabetes group reported a higher rate of tobacco use, whereas females showed similar or higher rates of use for every illicit drug studied. Among patients with diabetes, those who are engaged in risky behaviour showed a higher rate of treatment mismanagement (76% vs 34%, p < 0.01). Conclusion: Adolescents with T1DM are as likely as their healthy peers to engage in risky behaviour, indicating the potential benefit of anticipatory guidance concerning glycaemic control and increased risk of acute and chronic complications.  相似文献   
37.
38.
39.
40.
OBJECTIVE: To determine the effect of orlistat, a new lipase inhibitor, on long-term weight loss, to determine the extent to which orlistat treatment minimizes weight regain in a second year of treatment, and to assess the effects of orlistat on obesity-related risk factors. RESEARCH METHODS AND PROCEDURES: This was a 2-year, multicenter, randomized, double-blind, placebo-controlled study. Obese patients (body mass index 28 to 43 kg/m2) were randomized to placebo or orlistat (60 or 120 mg) three times a day, combined with a hypocaloric diet during the first year and a weight maintenance diet in the second year of treatment to prevent weight regain. Changes in body weight, lipid profile, glycemic control, blood pressure, quality of life, safety, and tolerability were measured. RESULTS: Orlistat-treated patients lost significantly more weight (p<0.001) than placebo-treated patients after Year 1 (6.6%, 8.6%, and 9.7% for the placebo, and orlistat 60 mg and 120 mg groups, respectively). During the second year, orlistat therapy produced less weight regain than placebo (p = 0.005 for orlistat 60 mg; p<0.001 for orlistat 120 mg). Several obesity-related risk factors improved significantly more with orlistat treatment than with placebo. Orlistat was generally well tolerated and only 6% of orlistat-treated patients withdrew because of adverse events. Orlistat leads to predictable gastrointestinal effects related to its mode of action, which were generally mild, transient, and self-limiting and usually occurred early during treatment. DISCUSSION: Orlistat administered for 2 years promotes weight loss and minimizes weight regain. Additionally, orlistat therapy improves lipid profile, blood pressure, and quality of life.  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