全文获取类型
收费全文 | 4603篇 |
免费 | 493篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 249篇 |
妇产科学 | 79篇 |
基础医学 | 636篇 |
口腔科学 | 148篇 |
临床医学 | 497篇 |
内科学 | 1107篇 |
皮肤病学 | 50篇 |
神经病学 | 555篇 |
特种医学 | 90篇 |
外国民族医学 | 1篇 |
外科学 | 399篇 |
综合类 | 103篇 |
一般理论 | 8篇 |
预防医学 | 466篇 |
眼科学 | 38篇 |
药学 | 364篇 |
中国医学 | 8篇 |
肿瘤学 | 264篇 |
出版年
2022年 | 41篇 |
2021年 | 78篇 |
2020年 | 51篇 |
2019年 | 66篇 |
2018年 | 79篇 |
2017年 | 54篇 |
2016年 | 54篇 |
2015年 | 77篇 |
2014年 | 89篇 |
2013年 | 149篇 |
2012年 | 233篇 |
2011年 | 221篇 |
2010年 | 114篇 |
2009年 | 100篇 |
2008年 | 209篇 |
2007年 | 220篇 |
2006年 | 209篇 |
2005年 | 200篇 |
2004年 | 187篇 |
2003年 | 206篇 |
2002年 | 199篇 |
2001年 | 121篇 |
2000年 | 96篇 |
1999年 | 113篇 |
1998年 | 46篇 |
1997年 | 56篇 |
1995年 | 46篇 |
1993年 | 40篇 |
1992年 | 77篇 |
1991年 | 99篇 |
1990年 | 76篇 |
1989年 | 79篇 |
1988年 | 88篇 |
1987年 | 101篇 |
1986年 | 80篇 |
1985年 | 79篇 |
1984年 | 60篇 |
1983年 | 59篇 |
1982年 | 46篇 |
1980年 | 44篇 |
1979年 | 82篇 |
1978年 | 60篇 |
1977年 | 54篇 |
1976年 | 42篇 |
1975年 | 41篇 |
1974年 | 51篇 |
1973年 | 46篇 |
1972年 | 38篇 |
1970年 | 42篇 |
1969年 | 42篇 |
排序方式: 共有5099条查询结果,搜索用时 0 毫秒
51.
Fish oil (FO) diets are associated with decreased thrombosis, which is though to be related, in part, to changes in platelet and vessel wall prostanoid synthesis. Recently, we found that 13-hydroxyoctadecadienoic acid (13-HODE) synthesized in the vessel wall from linoleic acid (LA, 18:2 n-6) via the lipoxygenase pathway, also decreases platelet/vessel wall interactions. Thus, we determined whether diets containing fish oil, walnut oil (rich in linoleic acid), black currant seed oil (rich in both linoleic and gamma linolenic acids, 18:3 n-6), or lard influenced vessel wall 13-HODE synthesis and platelet/vessel wall adhesion in rabbits. In vivo, vessel wall thrombogenicity was decreased in animals fed the black currant seed oil rich diet for 4 weeks as compared to the control "LARD" diet. This latter effect was better obtained when gamma linoleic acid was present suggesting a secondary effect of this fatty acid. The decreased vessel wall thrombogenicity in those animals, was associated with increased vessel wall 13-HODE synthesis. In contrast, ex vivo platelet adhesivity was significantly decreased in the fish oil diet fed animals, as compared to the control "LARD" diet and correlated with decreased platelet 12-HETE synthesis. We conclude that both fish oil and black currant seed oil rich diets inhibit platelet/vessel wall adhesion; the black current seed oil diet by increasing the availability of linoleic acid for 13-HODE synthesis and inhibiting vessel wall thrombogenicity; the fish oil diet, by inhibiting platelet 12-HETE synthesis and subsequent platelet adhesion. 相似文献
52.
Spectatoring refers to a cognitive self-absorption, wherein individuals fixate on and carefully monitor personal body parts and/or the adequacy of personal sexual functioning. To examine this process within a university population, undergraduate and graduate students (108 male and 140 female) filled out questionnaires that assessed body image, sexual knowledge, global sexual attitudes (i.e., liberal—conservative), general psychological adjustment, and frequency of sexual behaviors. Multiple regression analyses were used to determine if spectatoring, operationalized by measures of body image, would significantly predict sexually avoidant behavior. Results indicated that body image scores significantly predicted frequency of sexual behaviors for both genders, while general sexual knowledge and psychological adjustment did not predict sexual behavior. Overall, sexual attitude scores were the best predictors of sexual approach/avoidance behaviors for both genders. Implications are drawn for future research using the assessment of more global sex attitudes in the study of spectatoring. 相似文献
53.
Buchanan JL Bell RM Arnold SB Witsberger C Kane RL Garrard J 《Health care financing review》1990,11(3):67-78
Employment of geriatric nurse practitioners (GNPs) is one strategy to improve nursing home care. The effects of GNPs on costs and profitability of nursing homes and on costs of patient medical service use outside the nursing home are examined. Employment of GNPs does not adversely affect nursing home costs or significantly affect profits. There is some evidence of cost savings in medical service use for newly admitted patients but no evidence of savings for continuing residents. GNPs reduce the use of hospital services for both groups, and the reduction is statistically significant for newly admitted patients. 相似文献
54.
Children with leukemia and solid tumors are often hospitalized for empiric broad-spectrum antibiotic therapy because of fever during periods of chemotherapy-induced neutropenia. Conventional practice dictates that parenteral antibiotics be continued until the patient is afebrile and has recovered from neutropenia, ie, until the absolute neutrophil count (ANC) exceeds 500 cells per cubic millimeter. However, the practice in our center has been to discontinue parenteral antibiotic therapy and discharge many such patients before resolution of neutropenia. Since the feasibility and safety of this approach has not been studied, we reviewed the records of 114 consecutive hospitalizations for fever and neutropenia in 61 patients during a 13-month period. Seventy-seven children (68%) were discharged to their homes while still neutropenic after they had been afebrile for 1 to 2 days on parenteral antibiotics, had negative blood cultures, appeared well, and usually had some evidence of bone marrow recovery. Five patients (4.4%) developed recurrent fever and required rehospitalization within 7 days of discharge. Only three of the 77 patients (3.9%) who were sent home with neutropenia had recurrent fever. Each had a brief and uneventful second hospitalization. Two of the 37 children discharged with an ANC over 500 cells per cubic millimeter required rehospitalization. A declining ANC and advanced malignancy were risk factors in predicting recurrence of fever following discharge. A rising monocyte count was a predictor of imminent recovery from neutropenia. These results suggest that "early" discharge of an afebrile yet still neutropenic patient is safe when the patient is in remission, has no evidence of serious infection, appears clinically stable, and has indications of bone marrow recovery. The conventional approach of routinely continuing the hospitalization until resolution of neutropenia may be unnecessary in such low-risk patients. 相似文献
55.
G R Buchanan 《Hematology / Oncology Clinics of North America》1990,4(5):971-995
Although the results are steadily improving, the treatment of the child with lymphoblastic leukemia in relapse remains unsatisfactory. Owing to the very nature of relapse, it is highly unlikely that future chemotherapy protocols will provide curative treatment for the majority of patients with recurrent disease. Therefore, the greatest possible emphasis must be given to further improvements and refinements in front-line (initial) therapy so as to prevent relapse from ever occurring. Our goal should be to put the relapse leukemia specialist "out of business." 相似文献
56.
57.
Rogers SD Lampasona V Buchanan EC 《Topics in hospital pharmacy management / Aspen Systems Corporation》1994,14(1):60-66
The pharmacy-based investigational drug service plays an important role in the clinical research process. Investigators and sponsors often rely on the research pharmacist to assure drug accountability and to assist in educating staff about drug studies, reporting adverse reactions, and providing drug information. While many pharmacy departments across the country have established investigational drug services, there is an increasing need to justify these services from a financial perspective. Our pharmacy department currently provides investigational drug services for over 100 protocols. We have established a fee-for-service billing mechanism, but only 61% of our protocols are drug-company or investigator-sponsored, which reimburse for pharmacy services. As a result, we are unable to collect all operating costs through our billing mechanism. Many protocols, however, are sponsored by the National Cancer Institute (NCI), which provides free drugs for cancer protocols. Some NCI drugs are also on the market, so the hospital experiences savings in drug costs when patients are placed on certain NCI protocols. When we combine direct costs recovered through billing with the indirect cost savings from dispensing "free drugs, we find that the total benefit of operating an investigational drug service more than outweighs the cost of operating the service. 相似文献
58.
59.
Buchanan SD Diseker RA Sinks T Olson DR Daniel J Flodman T 《International journal of occupational and environmental health》1999,5(4):256-261
In 1993, the levels of copper (Cu) in much of Nebraska's drinking water exceeded the U.S. Environmental Protection Agency's (EPA) action level of 1.3 mg/L. To determine the association of copper with gastrointestinal (GI) illness in August 1994 the authors interviewed persons living in households with 1993 Cu levels > 3 mg/L (51 households), 2-3 mg/L (54 households), and < 1.3 mg/L (43 households). Cases were defined as persons who had experienced the rapid onset of vomiting or nausea with abdominal pain during the preceding two weeks. To validate their exposure index, the authors immediately resampled drinking water in the households of 25 cases and 27 controls matched for age. Reassessment in December 1994 of the exposure and case status of the original cohort showed no association between copper in drinking water in 1993 and case status in 1994. The risk of GI illness seemed no greater with Cu > 3 mg/L (RR = 1.03; 95% CI = 0.43, 2.49) or 2-3 mg/L (RR = 0.50; 95% CI = 0.18, 1.41) than with Cu < 1.3 mg/L. The 1993 Cu concentrations could not be reproduced in August 1994; resampling in December 1994 again showed no association between GI illness and Cu exposure (RR > 1.3-2.9 mg/L, < or = 1.3 mg/L = 0.25, 95% CI = 0.10, 0.64, and RR > or = 3.0 mg/L, < or = 1.3 mg/L = 0.36, 95% CI = 0.09, 1.49). 相似文献
60.