全文获取类型
收费全文 | 372篇 |
免费 | 20篇 |
国内免费 | 12篇 |
专业分类
儿科学 | 40篇 |
妇产科学 | 7篇 |
基础医学 | 21篇 |
口腔科学 | 10篇 |
临床医学 | 38篇 |
内科学 | 82篇 |
皮肤病学 | 5篇 |
神经病学 | 9篇 |
特种医学 | 70篇 |
外科学 | 19篇 |
综合类 | 17篇 |
预防医学 | 14篇 |
药学 | 36篇 |
肿瘤学 | 36篇 |
出版年
2023年 | 1篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 15篇 |
2011年 | 7篇 |
2010年 | 22篇 |
2009年 | 16篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 15篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 14篇 |
1998年 | 29篇 |
1997年 | 19篇 |
1996年 | 21篇 |
1995年 | 17篇 |
1994年 | 16篇 |
1993年 | 13篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1950年 | 1篇 |
排序方式: 共有404条查询结果,搜索用时 815 毫秒
21.
NRM Buist AP Prince KL Huntington JM Tuerck DD Waggoner 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):75-77
A new amino acid mixture for incorporation into medical foods for the treatment of hyperphenylalaninemia has been tested in a regular clinic. The mix is designed to be as unobtrusive as possible, consistent with good nutrition. After more than 1 year of trial as a beverage, we have shown that it is safe and well tolerated but that plasma phenylalanine is no better controlled than with some other products. The mix can be incorporated into a large number of different foods without affecting the taste. Occult monitoring of the quantity of medical foods purchased compared with the amounts reported to be consumed in diet histories provides an excellent way to monitor dietary compliance. 相似文献
22.
23.
Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women. 相似文献
24.
Reed SD Cushing-Haugen KL Daling JR Scholes D Schwartz SM 《Menopause (New York, N.Y.)》2004,11(2):214-222
OBJECTIVE: Leiomyomas are common benign neoplasms. Although hormone therapy is the most common and effective treatment for menopausal symptoms, little is known about its effect on leiomyomas. We examined the risk of a first diagnosis of leiomyomas in peri- and postmenopausal women associated with prior use of estrogen and progestogen therapy (EPT). DESIGN: A case-control study was conducted among enrollees from a nonprofit health plan. Cases had a first diagnosis of leiomyomas confirmed by surgery or ultrasound. Controls were women of the same age range without a diagnosis of leiomyomas selected at random from membership and outpatient files. Participants were interviewed regarding prior use of exogenous hormones, medical history, and reproductive history. This analysis was restricted to cases (n = 256) and controls (n = 276) who were peri- or postmenopausal and more than 40 years of age. Adjusted odds ratios (OR) and 95% CIs were estimated using logistic regression models. RESULTS: EPT use for more than 5 years was associated with a 1.7-fold increased risk of leiomyomas (95% CI, 0.9-3.3). Associations with EPT use were only present among women with a body mass index less than 24 kg/m; OR (ever-use), 2.3 (95% CI, 1.2-4.3); and OR (>or= 5 years use), 4.0 (95% CI, 1.6-10.3). CONCLUSION: Among peri- and postmenopausal women, prior EPT use was associated with an increased risk of a subsequent leiomyomas. This association seemed limited to the subset of women with low body mass index. Exogenous sources of estrogen and progestin in the setting of low adiposity may contribute to the development of leiomyomas. 相似文献
25.
OBJECTIVE: To determine whether current contraceptive method affects functional ovarian cyst risk, with emphasis on oral contraceptives (OCs) and tubal sterilization. METHODS: We conducted a case-control study of 18-39-year-old health maintenance organization enrollees with a functional ovarian cyst diagnosed between January 1, and June 30, 1994, and age-matched female controls randomly selected from enrollment files. In-person interviews as well as medical and pharmacy records were obtained for 78% of cases and 82% of controls; these analyses were based on 392 cases and 623 controls. Odds ratios (ORs) calculated with unconditional logistic regression were used to estimate the risk of a functional ovarian cyst diagnosis associated with current contraceptive method. RESULTS: In multivariable analyses adjusting for age, education, number of live births, and reference year, the overall OR was 0.72 (95% confidence interval [CI] 0.53, 0.99) for current OC use, compared with use of nonsurgical nonhormonal contraception or no contraception. The risk associated with use of 35 microg ethinyl estradiol monophasic OCs (OR 0.69; 95% CI 0.44, 1.10) was slightly lower than that associated with less than 35 microg ethinyl estradiol monophasic (OR 0.79; 95% CI 0.43, 1.47) or multiphasic OCs (OR 0.76; 95% CI 0.49, 1.19). Women with tubal sterilization had a substantially increased risk of a functional ovarian cyst diagnosis (OR 1.70; 95% CI 1.05, 2.75) compared with women using nonhormonal or no contraception. CONCLUSION: Our findings suggest that low-dose OC use has little or no effect on functional ovarian cyst likelihood. The increased risks we found associated with tubal sterilization merit further investigation. 相似文献
26.
Hormone replacement therapy regimens and breast cancer risk(1) 总被引:3,自引:0,他引:3
Weiss LK Burkman RT Cushing-Haugen KL Voigt LF Simon MS Daling JR Norman SA Bernstein L Ursin G Marchbanks PA Strom BL Berlin JA Weber AL Doody DR Wingo PA McDonald JA Malone KE Folger SG Spirtas R 《Obstetrics and gynecology》2002,100(6):1148-1158
Hormone replacement therapy (HRT) has increased in the United States over the past 2 decades in response to reports of long-term health benefits. A relationship between HRT and breast cancer risk has been observed in a number of epidemiological studies. In 2002, the Women's Health Initiative Randomized Controlled Trial reported an association between continuous combined HRT and breast cancer risk. The objective of this study was to examine the association between breast cancer risk and HRT according to regimen and duration and recency of use.A multicenter, population-based, case-control study was conducted in five United States metropolitan areas from 1994 to 1998. Analyzed were data from 3823 postmenopausal white and black women (1870 cases and 1953 controls) aged 35-64 years. Odds ratios (ORs) were calculated as estimates of breast cancer risk using standard, unconditional, multivariable logistic regression analysis. Potential confounders were included in the final model if they altered ORs by 10% or more. Two-sided P values for trend were computed from the likelihood ratio statistic.Continuous combined HRT was associated with increased breast cancer risk among current users of 5 or more years (1.54; 95% confidence interval 1.10, 2.17). Additionally, a statistically significant trend indicating increasing breast cancer risk with longer duration of continuous combined HRT was observed among current users (P =.01). There were no positive associations between breast cancer risk and other HRT regimens.Our data suggest a positive association between continuous combined HRT and breast cancer risk among current, longer term users. Progestin administered in an uninterrupted regimen may be a contributing factor. Risk dissipates once use is discontinued. 相似文献
27.
BACKGROUND: Limited data are available regarding the incidence of breast carcinoma among users of relatively recently introduced forms of antihypertensive therapy. Although it has been suggested that women who have taken calcium channel blockers (CCBs) have an increased risk and that women who have taken angiotensin-I-converting enzyme (ACE) inhibitors have a decreased risk, currently, no conclusions can be drawn. METHODS: A population-based case-control study of women ages 65-79 years was conducted in western Washington State. The responses of 975 women who were diagnosed with invasive breast carcinoma during 1997-1999 were compared with the responses of 1007 women in a control group. Associations between use of different types of antihypertensive medications and breast carcinoma incidence were evaluated using logistic regression. RESULTS: Overall, women who had ever used CCBs, beta-blockers, or ACE inhibitors did not have an altered risk of breast carcinoma relative to women who had never used antihypertensive medications. Although the use of immediate-release CCBs, thiazide diuretics, and potassium-sparing diuretics was associated with modestly increased risks of breast carcinoma (odds ratio [OR], 1.5; 95% confidence interval [95% CI], 1.0-2.1; OR, 1.4; 95% CI, 1.1-1.8; and OR, 1.6; 95% CI, 1.2-2.1, respectively), the absence of any trend in the size of excess risk with increasing duration or with current versus former use of these agents argues for a cautious interpretation. CONCLUSIONS: The use of particular types of antihypertensive medications, including immediate-release CCBs and certain diuretics, may increase the risk of breast carcinoma among older women. Additional studies are warranted to clarify these potential associations. Cancer 2003;98:1504-13. 相似文献
28.
H Kaube YE Knight RJ Storer KL Hoskin A May PJ Goadsby 《Cephalalgia : an international journal of headache》1999,19(6):592-597
It remains an open question as to whether cortical spreading depression (CSD) is the pathophysiological correlate of the neurological symptoms in migraine with aura. In the experimental animal, CSD is an electrophysiological phenomenon mainly mediated via NMDA receptors. However, according to case reports in humans, visual aura in migraine can be alleviated by vasodilator substances, such as amyl nitrite and isoprenaline. There is also circumstantial evidence that brainstem nuclei (dorsal raphe nucleus and locus coeruleus) may play a pivotal role in the initiation of aura. In this study, CSD was elicited in alpha-chloralose anesthetized cats by cortical needle stab injury and monitored by means of laser Doppler flowmetry. Topical application of isoprenaline (0.1-1%) and amyl nitrite (0.05%) onto the exposed cortex had no effect on the elicitation or propagation of CSD. Also, after supracollicular transection, subsequent CSDs showed no differences in the speed of propagation and associated flow changes. We conclude from these data that--given CSD probably exists in humans during migraine--spreading neurological deficits during migraine aura are independent of brainstem influence and have a primarily neuronal rather than vascular mechanism of generation. 相似文献
29.
30.
High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases. 相似文献