全文获取类型
收费全文 | 1351篇 |
免费 | 59篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 92篇 |
妇产科学 | 24篇 |
基础医学 | 113篇 |
口腔科学 | 13篇 |
临床医学 | 181篇 |
内科学 | 314篇 |
皮肤病学 | 5篇 |
神经病学 | 71篇 |
特种医学 | 149篇 |
外科学 | 95篇 |
综合类 | 54篇 |
预防医学 | 136篇 |
眼科学 | 16篇 |
药学 | 77篇 |
中国医学 | 1篇 |
肿瘤学 | 85篇 |
出版年
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 36篇 |
2013年 | 41篇 |
2012年 | 54篇 |
2011年 | 49篇 |
2010年 | 37篇 |
2009年 | 24篇 |
2008年 | 35篇 |
2007年 | 32篇 |
2006年 | 33篇 |
2005年 | 35篇 |
2004年 | 31篇 |
2003年 | 39篇 |
2002年 | 38篇 |
2001年 | 29篇 |
2000年 | 33篇 |
1999年 | 39篇 |
1998年 | 38篇 |
1997年 | 35篇 |
1996年 | 30篇 |
1995年 | 27篇 |
1994年 | 30篇 |
1993年 | 27篇 |
1992年 | 26篇 |
1991年 | 27篇 |
1990年 | 35篇 |
1989年 | 61篇 |
1988年 | 52篇 |
1987年 | 39篇 |
1986年 | 36篇 |
1985年 | 46篇 |
1984年 | 25篇 |
1983年 | 23篇 |
1982年 | 13篇 |
1981年 | 20篇 |
1980年 | 20篇 |
1979年 | 31篇 |
1978年 | 14篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1970年 | 9篇 |
1969年 | 7篇 |
排序方式: 共有1429条查询结果,搜索用时 15 毫秒
1.
2.
3.
Sonoelasticity imaging of prostate cancer: in vitro results 总被引:2,自引:0,他引:2
4.
Removing sodium from standard ionic contrastmedia markedly increases the incidence of ventricu-lar fibrillation in patients undergoing coronary arvgiography. Newer nonionic contrast media, Iopa-midol (IOP), Iohexol (IOH) and Ioversol (IOV),contain only trace amounts of sodium. To determinewhether sodium influences the fibrillatory propen-sity of nonionic contrast media, we measured theprolongation in QT interval and performed program-med electrical stimulation with l,2 and 3 ventricularextra stimuli in 40 dogs during 4 ml intracoronaryinjections of IOP, IOH and IOV. Solutions of eachcontrast media with added NaCI at concentrations of0.225To, 0.45% and 0.970 were compared to stockcontrast media. The addition of NaCI markedlyincreased the amount of QT interval prolongationproduced by each contrast media. With IOP, theamount of QT interval prolongation was 40+11msec with standard IOP but was 58+11 msec with0.225'70 NaCI/IOP, 84+17 msec with 0.45'To NaCI/IOP, and 132+42 msec with 0.970 NaCl/IOP(P相似文献
5.
R Yip I Parvanta K Scanlon E W Borland C M Russell F L Trowbridge 《Morbidity and mortality weekly report. Surveillance summaries (Washington, D.C. : 2002)》1992,41(7):1-24
The CDC Pediatric Nutrition Surveillance System (PedNSS) monitors the general health and nutritional characteristics of low-income U.S. children who participate in multiple public health programs. This system is intended to characterize trends and patterns in key indicators of nutritional status so that the information can be used for program planning and targeting. The indicators monitored by PedNSS are birth weight, childhood growth status, anemia, and breast-feeding patterns. From 1980 through 1991, the trends for low birth weight, low height-for-age (shortness), low weight-for-height (thinness), and high weight-for-height (overweight) were stable for all children monitored by the PedNSS, with the exception of Asian children, who were predominantly of Southeast Asian refugee background. In the early 1980s, the prevalence of low birth weight and shortness was higher among Asian children than among children of other racial or ethnic groups who were monitored by the PedNSS. However, these prevalences declined steadily from 1980 through 1991. By 1991, the prevalences of low birth weight and shortness for Asian children were similar to those observed for children of other races/ethnic groups. Overall, low-income U.S. children had a slightly lower height-for-age than expected, indicating that some of these children were at a health and nutritional disadvantage. The prevalence of overweight varied among different racial/ethnic groups; Hispanic and Native American children had the highest prevalences of overweight. The 20%-30% prevalence of anemia among low-income children monitored by the PedNSS was higher than among the general population, reflecting in part the preferential enrollment and retention of anemic children by public health nutrition programs and also indicating that many children had inadequate iron nutrition. From 1980 through 1991, the prevalence of anemia declined > 5% for most of the age- and race/ethnicity-specific groups monitored by PedNSS. That decline represents an improvement in iron nutritional status. PedNSS is a useful system for the monitoring and characterization of the nutrition status of low-income children at both state and national levels. 相似文献
6.
Screening for early ovarian cancer 总被引:5,自引:0,他引:5
7.
An outbreak of hypervitaminosis D associated with the overfortification of milk from a home-delivery dairy. 总被引:3,自引:1,他引:2 下载免费PDF全文
OBJECTIVES. The purpose of the study was to identify cases of hypervitaminosis D caused by the inadvertent overfortification of milk from a home-delivery dairy and to identify risk factors for this illness. METHODS. Hospital discharge, laboratory, and state health department data were used to define, identify, and describe cases of hypervitaminosis D diagnosed in the exposed communities between January 1, 1985, and June 30, 1991. To identify disease risk factors, community-based sex- and age-matched controls were used in a case-control study. RESULTS. Of the 56 case patients identified, at least 41 were hospitalized; 2 died. The study included 33 case patients and 93 control subjects. Nineteen of the 33 case patients had been customers of the implicated dairy. Risk of illness rose with increasing consumption of the dairy's milk and was also associated with vitamin D supplement use, sunburn susceptibility, and cancer history. Accounting for these factors did not alter the association between drinking the dairy's milk and developing hypervitaminosis D. CONCLUSIONS. Overfortification of milk with vitamin D can lead to hypervitaminosis D, manifested by severe illness and death. The episode highlights the need for monitoring the fortification process and enforcing the upper limit for vitamin D addition to milk. 相似文献
8.
9.
OBJECTIVE: Throughout health care literature, vulnerability is widely accepted as a potential issue for all patients yet the consensus on the meaning of and practical strategies to reduce or manage these 'harmful agents' in the clinical context are rarely offered. Three main themes emerge from the related literature which can be further refined into general terms of; social vulnerability--a person's basic statistical data in relation to their potential for illness; psychological vulnerability--the actual or potential harm to the identity of self and/or other emotional effects such as anxiety or stress caused by the ailment or treatment; and physical vulnerability--which refers to the actual physiological state where an individual is susceptible to further morbidity or mortality. SETTING: Acute care facilities. PRIMARY ARGUMENT: Although there is acknowledgment within the literature that individuals will experience some form of vulnerability when hospitalised, the complexity of what defines vulnerability for individuals causes further problems for patients and health professionals alike. CONCLUSIONS: This paper attempts to define vulnerability within the context of Western health care systems and raises the following issues: all states of vulnerability are accurate and appropriate in the context of the study or incidence alluded to, but further discussion and research is required to achieve a consensus to when, how, why and who is vulnerable. It is this recognition of the potentially differing classifications of vulnerability and the particular contexts that can be used that may assist nurses and other health care professionals with, not only problems associated with a patient's hospitalisation, but in the implementation of appropriate strategies to individual patient's cases. 相似文献
10.
Graham C Scanlon Mark S Wallace J Sorin Ispirescu Gery Schulteis 《Journal of investigative medicine》2006,54(5):238-244
BACKGROUND: Intradermal capsaicin is a human pain model that produces reliable pain and sensitization. This model facilitates controlled testing of analgesic efficacy via a crossover design while minimizing confounding variables in clinical pain states and retaining sufficient power with small samples. METHODS: To determine the lowest dose of capsaicin that produces consistent neurosensory measures, we administered 0.1, 1, 10, or 100 microg to healthy volunteers in a blinded manner (N = 19). Pain scores were recorded at 0, 5, 10, 15, and 60 minutes on a visual analog scale from 0 to 100. Areas and intensities of mechanical allodynia (foam brush stimulus) and pinprick hyperalgesia (von Frey test) were quantified at 15 and 60 minutes, as were flare areas. RESULTS: Capsaicin produced dose-dependent increases in spontaneous pain (p = .013), the area and intensity of mechanical allodynia (p = .006 and p < .001, respectively), the area and intensity of pinprick hyperalgesia (p = .010 and p = .014, respectively), and the flare area (p = .010). The 10 microg dose produced greater spontaneous pain than the 1 microg dose (p = .017). The 100 microg dose produced greater spontaneous pain than the 10 microg, but the difference was not statistically significant. CONCLUSION: The 10 and 100 microg capsaicin doses produced robust pain measures across a range of modalities, and lower doses produced minimal effects. Whereas most studies use 100 microg, using a lower dose is reasonable and may facilitate detection of subtle analgesic effects--particularly with nonopioid analgesics--and drugs can be tested in lower doses, minimizing adverse side effects. 相似文献