首页 | 官方网站   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   1660篇
  免费   84篇
  国内免费   28篇
医药卫生   1772篇
  2022年   10篇
  2021年   11篇
  2020年   11篇
  2019年   14篇
  2018年   16篇
  2017年   15篇
  2016年   32篇
  2015年   35篇
  2014年   49篇
  2013年   59篇
  2012年   69篇
  2011年   62篇
  2010年   69篇
  2009年   57篇
  2008年   86篇
  2007年   83篇
  2006年   90篇
  2005年   69篇
  2004年   61篇
  2003年   56篇
  2002年   47篇
  2001年   60篇
  2000年   64篇
  1999年   62篇
  1998年   39篇
  1997年   47篇
  1996年   45篇
  1995年   39篇
  1994年   22篇
  1993年   31篇
  1992年   36篇
  1991年   29篇
  1990年   31篇
  1989年   28篇
  1988年   21篇
  1987年   24篇
  1986年   30篇
  1985年   21篇
  1984年   25篇
  1983年   12篇
  1982年   8篇
  1981年   5篇
  1980年   8篇
  1979年   13篇
  1978年   10篇
  1977年   5篇
  1964年   7篇
  1959年   4篇
  1958年   7篇
  1955年   4篇
排序方式: 共有1772条查询结果,搜索用时 15 毫秒
21.
In this work we studied the possible effects of acute exercise on some haematological parameters and on some functions of neutrophils in seven active and six inactive subjects. Physical exercise (10 min on a cycle ergometer at a heart rate of 150 beats · min–1) induced a significant increase in total leucocyte, lymphocyte and neutrophil concentrations in active subjects; serum iron and ferritin concentrations were lower in active compared to inactive subjects. Cellular adhesion, bactericidal activity and superoxide anion production did not change after exercise, while we also observed some differences between active and inactive subjects before exercise. In particular, the neutrophils from active subjects showed a significantly higher percentage of adhesion, higher bactericidal activity and lower superoxide anion production. In conclusion, the training induced changes in some neutrophil functions, while acute exercise influenced, overall, leucocyte concentrations.  相似文献   
22.
The aims of this study were to determine (1) whether acute suppression of bone formation could be evaluated after the administration of corticosteroids in man by quantitative bone histomorphometry; and (2) whether there were significant differences between the effects of prednisone and its analog deflazacort. Thirteen patients who needed high-dose corticosteroid therapy were randomly allocated to two groups of treatment (prednisone or deflazacort). Quantitative bone histomorphometry, using the technique of triple labeling, and biochemical measurements of bone turnover were studied. There were no differences in biochemical indices of bone turnover between prednisone and deflazacort at the beginning and end of the 15 days of treatment course. During corticosteroid treatment, there were no significant changes in biochemical indices of bone turnover but a significant decline in total alkaline phosphatase (P<0.01). Histomorphometric indices, as revealed by measurements of tetracycline interval and extent of labeling, showed no significant differences in either mineral apposition rate or bone formation rate in the two groups. We conclude that the acute glucocorticoid suppression of bone turnover by glucocorticoids is not detectable within the first 2 weeks of treatment by histomorphometric techniques. No differences in bone effects of prednisone and deflazacort were detected in this short-term study.  相似文献   
23.
Pregnancies in an 18-Year Follow-up after Biliopancreatic Diversion   总被引:4,自引:0,他引:4  
Background: 239 pregnancies occurred in 1136 women who had undergone biliopancreatic diversion (BPD). Methods: There were 73 abortions, and 14 pregnancies are presently in their course. The 152 term pregnancies (six twins) occurred in 129 women 2-173 months (mean 42.7) after BPD. Mean age and current excess weight were 31.4 years (20-42) and 29.1% (-6.9-78.2), and mean excess weight loss was 72.9% (30.4-110.5). Results: Mean weight gain during pregnancy was 6.2 kg (-21-25). In 32 patients (21%), parenteral nutritional support was needed. In all the other patients (79%), the usual supplementations were given. Of the newborns, 122 were delivered at term (84.7%) with a mean weight of 2842.4 g (1760-4600 g) and a mean length of 48.5 cm (43-59 cm), while the 22 preterm babies (15.3%) weighed 2151.1 g (1400-3850 g) and had a length of 44.6 cm (33-56 cm). Forty infants (27.8%) were small for gestational age but 17 of them weighed more than 2500 g. Eleven twins (one abortion at 26th week) were also delivered, with a mean weight of 2088.6 g (1200-3100 g) and a mean length of 45.6 cm (35-50 cm). Delivery was spontaneous in 85 instances (56%), while vacuum extractor was used in one, and 66 cesarean sections were performed. There were two birth malformations, one infant died after surgery for meconium obstruction and two died from unknown causes. Of the 129 women, 35 had been infertile before BPD. Conclusions: Disappearance of infertility and decrease of pregnancy risk are to be considered among the beneficial effects of weight reduction following BPD.  相似文献   
24.
A woman's reproductive history influences her risk of breast cancer. The authors hypothesized that reproductive history also influences stage of disease at the time of diagnosis. The authors analyzed a population-based cohort of 1.5 million Danish women born between 1935 and 1978 for whom individual information on births was available. Between 1978 and 1994, 10,790 incident cases of breast cancer in women under 60 years of age were identified. Nulliparous women compared with parous women and women with a late age at first birth compared with an early age were at significantly increased risk of being diagnosed with a large tumor and with cancer that had spread to regional lymph nodes. However, such an association was not seen for women diagnosed with a small tumor and women with cancer that had not spread to regional lymph nodes. Reproductive history did not appear to influence the time interval from first symptoms to first physician visit ("patient delay") or the time interval from first physician visit to surgery ("doctor delay"). The authors conclude that reproductive history is associated both with incidence of breast cancer and with stage of the disease at diagnosis, indicating possible influences on tumor progression and growth rate. Intensified awareness is warranted to achieve earlier diagnosis among nulliparous women and women with a late age at first childbirth, with the hope of improving their prognosis.  相似文献   
25.
The role of possessing an abnormal body weight in the body image alterations of obese patients was evaluated in bariatric surgery subjects prior to and at long term after operation, when body weight and shape had become steadily normalized. Body image was assessed by the body dissatisfaction scale of the Eating Disorders Inventory, the Body Shape Questionnaire, and the Body Attitude Questionnaire. When the individuals were obese, a sharply impaired body image was observed; following operation, weight loss corresponded to normalization of body dissatisfaction, feeling of fatness, and physical attractiveness, whereas body disparagement and salience of shape, although improved in comparison to preoperative data, remained significantly different from that of controls. In the obese patients, some aspects of body image alterations are substantially accounted for by overweight status; other aspects reflect inner feelings, which are partially independent of the actual body weight and shape.  相似文献   
26.
In this work, we tested the pharmacotoxicological profile of three new nitro-anti-inflammatory agents, nitrofenac, nitronaproxen and nitroflurbiprofen with the following results:
  1. In models of acute (carrageenan oedema) and chronic (adjuvant arthritis) inflammation in the rat, the nitroderivatives, compared with the parent drugs, showed similar anti-inflammatory properties by significantly inhibiting both oedema volume and arthritis development.
  2. The nitroso compounds showed markedly less ulcerogenic activity compared with the parent drugs both in acute conditions and at the end of the chronic inflammation test.
  3. The lack of gastrointestinal damage observed with these new anti-inflammatory drugs is the consequence of their ability to release NO. This hypothesis is supported by pharmacokinetic studies and a significant increase in nitrite/nitrate plasma levels.
  相似文献   
27.
The association between multiple births and subsequent maternal breast cancer risk was explored in a nested case-control study in Sweden encompassing 19,368 parous women with breast cancer diagnosed up to age 65 years, and 100,459 parous controls. Among cases and controls, there were 329 and 2,031 women, respectively, with a history of at least one live multiple birth. Compared with singleton mothers, breast cancer risk was 12 percent lower (odds ratio=0.088, 95 percent confidence interval=0.78–0.99) in women who had had a multiple birth. After stratification for age at diagnosis, evidence of a significant inverse association was found only in women aged 54 years or younger. Birth order of the multiple pregnancy had no apparent risk-modifying effect. Age at earliest multiple birth was unrelated to breast cancer risk. The inverse association between twinning and breast cancer risk may reflect protective physiological features of twin pregnancies. Further research is needed to investigate the role, if any, of in creased levels of steroid hormone-binding globulins in mothers of twins and the proposed inhibitory effects of human chorionic gonadotropin and -fetoprotein, both of which are increased during multiple gestations, on breast carcinogenesis. Breast feeding patterns in mothers of twins also may modify their risk of developing breast cancer.Ambors are with the Department of Cancer Epidemiology (Drs Lambe Ekbom, Adami) and Department of Social Medicine (Lambe), University Hospital, Uppsala, Sweden: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA (Drs Hsieb, Tsilib, Adami, Ekbom, Trichopoulos); UMASS Cancer Center, Worcester, MA, USA (Dr Hsieb). Address correspondece to Dr Lambe, Department of Cancer Epidemiology, University Hospital, S-751 85 Uppsala, Sweden. This project is funded by grants from the Swedish Cencer Societv. the Swedish Societv of Medicine. and the Wahlmarks Fund at Uppsala City Council.  相似文献   
28.
There is increasing recognition of the association between Salmonellainfections and systemic lupus erythematosus (SLE). However,these infections have usually occurred in patients with establishedSLE who were receiving immunosuppressive therapy. We describetwo young women with previously undiagnosed SLE who developedSalmonella bacteraemia. Neither of these patients had receivedimmunosuppressive drugs. From these and two previously reportedpatients, it may be concluded that SLE per se is likely to beassociated with a defect in host defences to Salmonella bacteria. KEY WORDS: SLE, Non-typhoid Salmonella, Septicaemia  相似文献   
29.
30.
The aim of this study was to evaluate the usefulness of a major secretory protein of human chondrocytes (chondrex) as a potential serum marker of bone responsiveness to growth hormone (GH). The study included 18 children (10 F, 8 M), aged 10.9 ± 2.3 years, bone age 8.8 ± 2.7 years, height −2.3 ± 0.22 SDS, affected by isolated idiopathic GH deficiency (GHD). Serum samples for evaluation of chondrex, total, and bone alkaline phosphatase were taken before and 3 and 6 months following treatment with rhGH. The basal serum level of chondrex did not differ between patients (37 ± 22 ng/ml) and controls (33 ± 9.8 ng/ml). Following 6 months of treatment with rhGH, a significant increase of height velocity SDS (from −2.8 ± 0.5 to 1.3 ± 0.7), total (from 195 ± 47 to 264 ± 79 U/liter) and bone alkaline phosphatase (from 81 ± 21 to 108 ± 30 U/liter) was observed, while chondrex serum level remained unchanged (from 37 ± 22 to 36 ± 29 ng/ml). It was concluded that chondrex cannot be considered a reliable marker of bone responsiveness to GH in the growing child. Received: 19 March 1999 / Accepted: 3 February 2000  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-23

京公网安备 11010802026262号