全文获取类型
收费全文 | 1713篇 |
免费 | 124篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 92篇 |
妇产科学 | 61篇 |
基础医学 | 191篇 |
口腔科学 | 49篇 |
临床医学 | 229篇 |
内科学 | 289篇 |
皮肤病学 | 31篇 |
神经病学 | 66篇 |
特种医学 | 146篇 |
外科学 | 172篇 |
综合类 | 90篇 |
一般理论 | 4篇 |
预防医学 | 173篇 |
眼科学 | 24篇 |
药学 | 88篇 |
1篇 | |
中国医学 | 19篇 |
肿瘤学 | 109篇 |
出版年
2022年 | 13篇 |
2021年 | 38篇 |
2020年 | 18篇 |
2019年 | 32篇 |
2018年 | 42篇 |
2017年 | 27篇 |
2016年 | 20篇 |
2015年 | 52篇 |
2014年 | 55篇 |
2013年 | 58篇 |
2012年 | 78篇 |
2011年 | 89篇 |
2010年 | 63篇 |
2009年 | 54篇 |
2008年 | 68篇 |
2007年 | 77篇 |
2006年 | 46篇 |
2005年 | 44篇 |
2004年 | 47篇 |
2003年 | 53篇 |
2002年 | 31篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 22篇 |
1998年 | 33篇 |
1997年 | 29篇 |
1996年 | 37篇 |
1995年 | 30篇 |
1994年 | 30篇 |
1993年 | 23篇 |
1992年 | 27篇 |
1991年 | 39篇 |
1990年 | 30篇 |
1989年 | 39篇 |
1988年 | 46篇 |
1987年 | 33篇 |
1986年 | 37篇 |
1985年 | 29篇 |
1984年 | 36篇 |
1983年 | 31篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1979年 | 23篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1975年 | 14篇 |
1974年 | 10篇 |
1972年 | 15篇 |
排序方式: 共有1844条查询结果,搜索用时 0 毫秒
111.
I S Levenbook B A Merritt E A Fitzgerald B L Elisberg 《International archives of allergy and applied immunology》1986,80(1):110-111
beta-Propiolactone-treated (BPL-T) homologous serum albumin caused anaphylaxis in guinea pigs with a frequency and severity equal to that of guinea pigs inoculated with human albumin. Untreated guinea pig serum albumin did not cause any reactions in these animals. Some recipients of current rabies vaccine produced in human diploid cells available in the USA develop systemic allergic reactions, usually following booster immunization. The BPL-T human albumin component of the vaccines was believed to be the cause of the complications. Our studies support this conclusion. 相似文献
112.
113.
C J Caspersen B P Bloemberg W H Saris R K Merritt D Kromhout 《American journal of epidemiology》1991,133(11):1078-1092
Physical activity patterns and their relation with coronary heart disease risk factors are described for a representative sample of 863 Dutch men, 65-84 years old, who participated in the 1985 survey of the Zutphen cohort of the Seven Countries Study. Cross-sectional results revealed a median total of reported physical activity of about 1 hour and 20 minutes per day; only 5.8% reported no physical activity. The percentage of participation and total weekly time spent in physical activity decreased as age increased; the decrease was less pronounced for walking, bicycling, gardening, and doing odd jobs than for sports, hobbies, and work. Statistically significant mean differences were found among quartiles of total weekly physical activity for both total cholesterol and high-density lipoprotein cholesterol (HDL cholesterol); however, only the differences for HDL cholesterol remained significant (p = 0.045) after adjusting for potential confounders. Statistically significant regression coefficients (p less than 0.05) were found for the independent association between walking and total cholesterol and between gardening and total cholesterol, HDL cholesterol, and systolic blood pressure, after adjusting for confounders. Total weekly physical activity and specific activities, e.g., gardening and walking, demonstrated generally favorable associations with cholesterol and systolic blood pressure. 相似文献
114.
115.
T.C. Delgado C. Barosa M.M.C.A. Castro C.F.G.C. Geraldes M. Bastos C. Baptista A. Fagulha L. Barros A. Mota M. Carvalheiro J.G. Jones Matthew Merritt 《Magnetic resonance in medicine》2008,60(3):517-523
The contribution of gluconeogenesis to hepatic glucose production (GP) was quantified after 2H2O ingestion by Bayesian analysis of the position 2 and 5 2H‐NMR signals (H2 and H5) of monoacetone glucose (MAG) derived from urinary acetaminophen glucuronide. Six controls and 10 kidney transplant (KTx) patients with cyclosporine A (CsA) immunosuppressant therapy were studied. Seven KTx patients were lean and euglycemic (BMI = 24.3 ± 1.0 kg/m2; fasting glucose = 4.7 ± 0.1 mM) while three were obese and hyperglycemic (BMI = 30.5 ± 0.7 kg/m2; fasting glucose = 7.1 ± 0.5 mM). For the 16 spectra analyzed, the mean coefficient of variation for the gluconeogenesis contribution was 10% ± 5%. This uncertainty was associated with a mean signal‐to‐noise ratio (SNR) of 79:1 and 45:1 for the MAG H2 and H5 signals, respectively. For control subjects, gluconeogenesis contributed 54% ± 7% of GP as determined by the mean and standard deviation (SD) of individual Bayesian analyses. For the lean/normoglycemic KTx subjects, the gluconeogenic contribution to GP was 62% ± 7% (P = 0.06 vs. controls), while hyperglycemic/obese KTx patients had a gluconeogenic contribution of 68% ± 3% (P < 0.005 vs. controls). These data suggest that in KTx patients, an increased gluconeogenic contribution to GP is strongly associated with obesity and hyperglycemia. Magn Reson Med 60:517–523, 2008. © 2008 Wiley‐Liss, Inc. 相似文献
116.
J R Kirsch M N Diringer C O Borel D F Hanley W T Merritt G B Bulkley 《Critical care medicine》1991,19(12):1474-1479
OBJECTIVE: To test the hypothesis that preoperative lumbar epidural morphine improves postoperative pain control and ventilatory function after transsternal thymectomy in patients with myasthenia gravis. DESIGN: The study design was randomized, placebo-controlled, and double-blind. SETTING: After surgery, all patients were admitted to the Neuroscience Critical Care Unit for evaluation and treatment. PATIENTS: All patients with myasthenia gravis who presented to the hospital for thymectomy were asked to participate in the study. Twenty patients were randomized to either the placebo or epidural morphine groups. INTERVENTIONS: Patients received either epidural morphine (7 mg in 14 mL of sterile saline) or saline (14 mL) before induction of anesthesia. Supplemental iv opioids were administered intraoperatively, with need determined by the anesthesiologist. MAIN OUTCOME MEASURES: The main outcome measures were indicators of postoperative pain (e.g., Visual Analog Pain Score, requirement for supplemental opioid administration, respiratory rate) and ventilatory function (e.g., forced vital capacity, negative inspiratory pressure). RESULTS: Immediately after surgery, the Visual Analog Pain Score in the placebo group was twice as high as the score in the epidural morphine group (placebo 7.0 +/- 1.3; epidural morphine 3.5 +/- 1.2, p less than or equal to .05). During the first eight postoperative hours, the placebo group required more opioids (0.22 +/- 0.03 vs. 0.12 +/- 0.04 mg/kg morphine equivalents, p less than or equal to .06) than the epidural morphine group. Later, both groups received similar amounts of opioids. Patients receiving epidural morphine had better initial recovery of forced vital capacity (at 8 hrs: 55 +/- 6% [epidural morphine] vs. 34 +/- 5% [placebo] of preoperative value, p less than or equal to .05). Respiratory rate was lower for the first 12 postoperative hours in the epidural morphine group, without a difference in PaCO2. There was no difference between groups for the duration of postoperative intubation or ventilation. CONCLUSIONS: Preoperative lumbar epidural morphine facilitates postoperative analgesia and improves initial postoperative ventilatory performance. 相似文献
117.
N Gilliard P M Richman T A Merritt R G Spragg 《The American review of respiratory disease》1990,141(3):743-747
Administration of exogenous lung surfactant to infants with or at risk for respiratory distress syndrome has been demonstrated to improve gas exchange and survival; administration of surfactant to patients with the adult respiratory distress syndrome is currently undergoing clinical evaluation. Although it is currently assumed the optimal effect will occur when administered surfactant is distributed homogeneously throughout the lung, little is known of the influence of variables inherent in the administration procedure on subsequent distribution. To address this question, we studied the effect of the volume size in which the surfactant is suspended for instillation, and demonstrated a marked relationship in the normal rabbit lung between this volume and the subsequent homogeneity of surfactant distribution. In the rabbit lung that was acutely injured by oleic acid, this relationship was not evident. Concentration of administered surfactant was not demonstrated to be of major influence on its distribution after administration. Our results focus attention on the importance of parameters of the administration procedure, and also demonstrate the usefulness of the techniques used for determination of surfactant distribution. 相似文献
118.
Larry G Merritt 《The Journal of the Canadian Chiropractic Association》2001,45(4):221-224
Manipulation and exercise are recommended by chiropractors for treatment and prevention of low back problems. Many patients stop their exercise program with improvement in their symptoms. The success of exercises for the prevention of low back pain is dependent on several factors, one being continued compliance to the program. Only a small percentage of the general population do regular exercise; therefore, it is essential that patients recognize the importance of regular exercise in reducing the recurrence of their low back pain. This case study shows how the use of a gym ball appears to have improved compliance and reduced the incidence of low back pain for one patient with a history of re-occurring low back pain and a poor record of exercise compliance. The question must be asked, is this an case incident or is use of the gym ball an appropriate treatment for low back pain? 相似文献
119.
120.