全文获取类型
收费全文 | 2574篇 |
免费 | 436篇 |
国内免费 | 4篇 |
学科分类
医药卫生 | 3014篇 |
出版年
2021年 | 31篇 |
2019年 | 29篇 |
2015年 | 34篇 |
2013年 | 83篇 |
2012年 | 81篇 |
2011年 | 82篇 |
2010年 | 59篇 |
2009年 | 74篇 |
2008年 | 71篇 |
2007年 | 78篇 |
2006年 | 88篇 |
2005年 | 95篇 |
2004年 | 86篇 |
2003年 | 68篇 |
2002年 | 76篇 |
2001年 | 65篇 |
2000年 | 54篇 |
1999年 | 55篇 |
1998年 | 43篇 |
1997年 | 53篇 |
1996年 | 58篇 |
1995年 | 46篇 |
1994年 | 54篇 |
1993年 | 41篇 |
1992年 | 59篇 |
1991年 | 53篇 |
1990年 | 72篇 |
1989年 | 75篇 |
1988年 | 57篇 |
1987年 | 59篇 |
1986年 | 57篇 |
1985年 | 48篇 |
1984年 | 38篇 |
1983年 | 36篇 |
1982年 | 45篇 |
1981年 | 49篇 |
1980年 | 47篇 |
1979年 | 72篇 |
1978年 | 55篇 |
1977年 | 53篇 |
1976年 | 49篇 |
1975年 | 36篇 |
1974年 | 59篇 |
1973年 | 47篇 |
1972年 | 43篇 |
1971年 | 47篇 |
1970年 | 47篇 |
1969年 | 43篇 |
1968年 | 37篇 |
1967年 | 29篇 |
排序方式: 共有3014条查询结果,搜索用时 0 毫秒
1.
The effect of bracing on proprioception of knees with anterior cruciate ligament injury. 总被引:2,自引:0,他引:2
Bruce D Beynnon Lars Good May Arna Risberg 《The Journal of orthopaedic and sports physical therapy》2002,32(1):11-15
This paper is a comprehensive review on the effect of bandaging, bracing, and neoprene sleeves on knee proprioception following anterior cruciate ligament (ACL) injury and reconstruction with a focus on studies that have measured joint position sense and threshold to detection of passive knee motion. Disruption of the ACL does not appear to alter joint position sense soon after injury, although there is evidence that in some subjects deterioration may occur over time. An ACL tear creates a deficit in the threshold to detection of passive knee motion soon after injury and in those with chronic tears. The magnitude of worsening is less then 1.0 degree of movement in flexion-extension and of questionable concern from a clinical and functional perspective. Application of a functional brace or neoprene sleeve to the ACL-deficient limb does not improve the threshold to detection of passive knee motion; however, application of an elastic bandage to a knee with an ACL tear improves joint position sense. Reconstruction of a torn ACL is associated with a deficit in the threshold to detection of passive knee motion, and during the first year of healing the use of a neoprene sleeve provides improvement. Two years following ACL reconstruction there is no deficit in the threshold to detection of passive knee motion and the use of a brace has no effect on this outcome. 相似文献
2.
Behavioral correlates of poor vision in children 总被引:1,自引:0,他引:1
3.
In this enzymatic method to analyze erythrocytes for D-sorbitol, the erythrocytes were separated from plasma by centrifugation, washed with isotonic saline (9 g/L NaCl), then diluted threefold with more saline. We lysed 1.5 mL of the diluted erythrocytes with chloroform and precipitated the protein with 58 g/L HClO4 solution. The resulting supernates were mixed with buffer, NAD+, and sorbitol dehydrogenase (EC 1.1.1.14). For standards, we added sorbitol to the erythrocytes before lysing. After 25 min of incubation at 37 degrees C, the fluorescence responses were recorded. Results for sorbitol were corrected for sample-blank and enzyme fluorescence, and were then normalized for hemoglobin content. Response was linear for a sorbitol concentration range of 1 to 30 mumol/L. Reproducibility was good, with an average CV of 2.5% at 10 mumol/L. Results for healthy individuals and diabetic patients are presented. 相似文献
4.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
5.
Innate immunity and its role against infections. 总被引:5,自引:0,他引:5
Suwannee Uthaisangsook Noorbibi K Day Sami L Bahna Robert A Good Soichi Haraguchi 《Annals of allergy, asthma & immunology》2002,88(3):253-64; quiz 265-6, 318
LEARNING OBJECTIVES: This article reviews current concepts of the innate immune system that offers protection against infections. It offers an overview for the readers to understand how innate immunity, consisting of different receptors, cells, and mediators recognizes pathogens and exerts protective function against pathogens. DATA SOURCES AND STUDY SELECTION: MEDLINE-search articles including original research papers, review articles, textbooks, and references identified from bibliographies of relevant articles. RESULTS AND CONCLUSIONS: The innate immune system is nonspecific immunity present since birth not requiring repeated exposure to pathogens. It is capable of differentiation between self and nonself. Because of its nonspecificity, it has a broad spectrum of resistance to infection. Further, it is thought to play an important role in the control of adaptive immunity by regulating co-stimulatory molecules and effector cytokines. Innate immunity includes pattern recognition molecules/receptors, antimicrobial peptides, the complement system, inflammatory mediators, and cytokines produced by immune cells. Pattern recognition molecules/receptors recognize pathogen-associated molecular patterns that are essential for microorganisms' survival and pathogenicity. Although innate immunity has recently gained increasing importance, further studies are necessary for a better understanding of its role. 相似文献
6.
Non-A Non-B Hepatitis and the Safety of Intravenous Immune Globulin, pH 4.2: A Retrospective Survey: 总被引:1,自引:0,他引:1
Ralph H. Rousell Robert A. Good Bernard Pirofsky and Richard I. Schiff 《Vox sanguinis》1988,54(1):6-13
Abstract. Evidence for transmission of non-A non-B hepatitis (NANB) was sought in 41 patients with primary immune deficiency who were receiving human intravenous immune globulin (IGIV) over periods ranging from 6 to 15 months at a monthly dosage of 400 mg/kg body weight. One lot of a reduced and alkylated IGIV and three lots of a nonmodified preparation stabilized at pH 4.2 were used. No evidence of NANB was found, although transient elevations in serum glutamic pyruvic transaminase (alanine aminotransferase) were found in 6 of the patients. The possible causes of the elevated levels in these 6 patients are discussed. 相似文献
7.
C I Eastman H W Lahmeyer L G Watell G D Good M A Young 《Journal of affective disorders》1992,26(4):211-221
We studied 32 patients with winter seasonal affective disorder (SAD) in a counterbalanced crossover design comparing 1 h of morning light treatment (about 7000 lux) to 1 h of morning placebo treatment (deactivated negative ion generator). Both treatments significantly reduced depression ratings, but there was no difference between the antidepressant response to light and to placebo. Several possible explanations for this result were discussed including an inadequate 'dose' of light (e.g., ineffective duration or intensity), an unusual sample of patients, and a placebo mechanism. 相似文献
8.
The authors describe 13 cocaine-exposed infants with optic nerve abnormalities, delayed visual maturation, and prolonged eyelid edema. Prolonged and potentially vision-threatening eyelid edema is a new clinical entity. The pharmacology of cocaine, its easy access to fetal circulation, and its neurotropic characteristics can be used to explain optic nerve abnormalities and delayed visual maturation. In infants with any of these eye abnormalities, a careful investigation for cocaine abuse is advisable. 相似文献
9.
The Laser Microprobe Mass Analyzer (LAMMA) is a sensitive instrument for identifying and localizing trace elements in tissue samples. Using LAMMA, we have examined melanin-containing neurons of the substantia nigra in patients with Parkinson's disease (PD) and controls. We found that iron significantly accumulates within neuromelanin granules of patients with PD compared to controls. Increased aluminum was found in the neuromelanin granules of 2 of 3 PD cases but in no controls. The accumulation of iron and aluminum, which are known to promote oxidant stress, may account for the selective degeneration of neuromelanin-containing neurons in PD. 相似文献