全文获取类型
收费全文 | 442篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 14篇 |
妇产科学 | 6篇 |
基础医学 | 81篇 |
口腔科学 | 25篇 |
临床医学 | 29篇 |
内科学 | 74篇 |
神经病学 | 33篇 |
特种医学 | 10篇 |
外科学 | 117篇 |
综合类 | 14篇 |
预防医学 | 49篇 |
药学 | 13篇 |
肿瘤学 | 10篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 8篇 |
2012年 | 18篇 |
2011年 | 30篇 |
2010年 | 5篇 |
2009年 | 10篇 |
2008年 | 22篇 |
2007年 | 17篇 |
2006年 | 22篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 14篇 |
2000年 | 22篇 |
1999年 | 14篇 |
1998年 | 13篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1993年 | 4篇 |
1992年 | 16篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 19篇 |
1985年 | 13篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 2篇 |
排序方式: 共有476条查询结果,搜索用时 15 毫秒
21.
22.
Two patients developed fat embolism syndrome after revision of loose total hip arthroplasties (THAs). During both procedures, the prosthesis became rigidly fixed 1 to 1.5 cm before the expected level of fixation. After uncomplicated operative courses, Patient A remained obtunded and febrile for 2.5 days, and Patient B died 1 day postoperatively. In Patient A, a presumptive diagnosis of fat embolism syndrome was based on the postoperative course and a radiograph of the lungs. In Patient B, the diagnosis was confirmed by evidence of cerebral edema on a computed tomography scan of the head. Fat embolism syndrome is unexpected after revision THA because the fatty tissue is removed from the femoral canal during primary THA. In these 2 cases, the rigid fixation and multiple attempts to impact and subsequently to remove the prosthesis may have caused fat embolism syndrome. 相似文献
23.
Weinstein SJ Gridley G Harty LC Diehl SR Brown LM Winn DM Bravo-Otero E Hayes RB 《The Journal of nutrition》2002,132(4):762-767
We examined the relationships between folate and methionine intake, serum homocysteine levels (as a biomarker for folate metabolism), and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism genotype and risk of oral cancer in a population-based, case-control study in Puerto Rico. Structured questionnaires were used to collect information on demographic factors, usual adult diet, and tobacco and alcohol use. Oral epithelial cells and blood samples were collected from a subset of subjects. Analyses were conducted by logistic regression, adjusting for age, sex, lifetime smoking and lifetime alcohol intake, with the following numbers of cases/controls, respectively: dietary data (341/521); MTHFR genotype (148/149); and homocysteine (60/90). Although increased folate intake was associated with decreased oral cancer risk [adjusted odds ratio (OR) in highest vs. lowest quartile = 0.6, 95% confidence interval (CI): 0.4, 1.0, P(trend) = 0.05)], this finding was due almost entirely to folate intake from fruit (adjusted OR = 0.4, 95% CI: 0.2, 0.6; P(trend) = 0.0001), whereas other dietary folate sources showed no clear association. Methionine intake and serum homocysteine levels were not associated with oral cancer risk. Subjects with the MTHFR C677T homozygous variant (TT) genotype had a nonsignificantly lower risk, and risk patterns tended to differ by level of folate, methionine, alcohol intake and smoking, although the power to detect significant associations in subgroups of these variables was low. Risks for oral cancer are not folate specific; preventive recommendations for this disease should emphasize the importance of a healthy diet, including substantial intake of fruits. 相似文献
24.
Harty JA Kelly P Niall D O'Keane JC Stephens MM 《Foot & ankle international / American Orthopaedic Foot and Ankle Society [and] Swiss Foot and Ankle Society》2000,21(5):408-412
We report the a case of Nora's lesion (Bizarre Parosteal Osteochondromatous Proliferation) of the sesamoid. A 32-year-old woman presented with a painless, enlarging mass of two years duration on the plantar aspect of the first metatarsophalangeal joint of the left foot. Radiographs, Computerized Tomographs and Magnetic Resonance images, initially suggested a parosteal osteosarcoma arising from the tibial sesamoid. The mass was excised, and a histological diagnosis of Bizarre Parosteal Osteochondromatous Proliferation of bone (Nora's lesion) was made. The aggressive growth of this lesion may suggest a neoplasm clinically. Histological features, however, are those of a reactive lesion. 相似文献
25.
26.
Enteric campylobacter: purging its secrets? 总被引:4,自引:0,他引:4
Campylobacterial infections are the most common cause of bacterial enterocolitis in humans. Among children, especially in developing countries, Campylobacter infections can cause severe life-threatening diarrheal disease. Although usually associated with a benign outcome in the developed world, the burden of illness posed by Campylobacter infections is enormous, and serious neurologic sequelae also can occur. For a variety of reasons our understanding of the molecular and cellular pathogenesis of Campylobacter infection has lagged far behind that of other enteric pathogens. However, recent completion of the genome sequence of Campylobacter jejuni promises to open up the Campylobacter research field with the prospect of developing novel therapeutic and preventive strategies. 相似文献
27.
28.
The aim of this study was to determine the prevalence of wheeze, eczema and rhinitis in 6-7 year old schoolchildren in Louth and Meath and assess their risk factors. The ISAAC (International Study for Asthma and Allergies in Childhood) questionnaire was used. The response rate was 64.1% (n = 1899). The prevalence rates for wheeze, eczema and rhinitis were 17.4%, 11.2% and 20.2% respectively, with 2.4% of children reported to be suffering from all 3 conditions. The main risk factors for wheeze were male sex and smoking in the home. Ninety-five (28.7%) children with wheeze had no diagnosis of asthma. Of these children 36 (37.9%) had wheeze with exercise, 55 (59.9%) had a dry cough not associated with a cold or flu and 13 (13.7%) reported more than 4 attacks of wheeze in the last year. This study suggests underdiagnosis and undertreatment of atopic illness in this age group. It also suggests decreasing exposure to passive smoking and early recognition and treatment will improve quality of life for many children. 相似文献
29.
2,5-Dimethoxy-4-n-propylthiophenethylamine (2C-T-7) has structural and pharmacodynamic similarities to methylenedioxymethamphetamine (MDMA). This compound was initially identified from a routine screening procedure in postmortem urine from a 20-year-old male that died in a local emergency room after reportedly insufflating 35 mg. This report describes the development of a quantitative method for 2C-T-7. A number of method parameters were studied including internal standard selection, liquid-liquid extraction scheme, and drug stability in preserved refrigerated blood. The adopted method for blood and urine involves the addition of trimethoxyamphetamine (TMA) as internal standard, alkalinization with ammonium hydroxide, and liquid-liquid extraction with n-chlorobutane. To facilitate recovery from liver, a 1:4 aqueous homogenate was pretreated with dilute perchloric acid, centrifuged, and the supernatant was extracted as previously described. In each case, 0.1% hydrochloric acid in methanol was added during the final concentration step to prevent loss of drug caused by evaporation. Samples were analyzed by gas chromatography with nitrogen-phosphorus detection (GC-NPD) and electron ionization GC-mass spectrometry (MS) utilizing selected ion monitoring. For the GC-MS analysis, the characteristic ions monitored for 2C-T-7 were m/z 226, 255, and 183 and for TMA, m/z 182. The limits of detection and quantitation in blood were 6.0 and 15.6 ng/mL, respectively, by both GC-NPD and GC-MS. The results from the postmortem case were as follows: heart blood, 57 ng/mL; femoral blood, 100 ng/mL; urine, 1120 ng/mL; and liver, 854 ng/g. 相似文献
30.
Synthetic analogues of the bacterial signal (quorum sensing) molecule N-(3-oxododecanoyl)-L-homoserine lactone as immune modulators 总被引:6,自引:0,他引:6
Chhabra SR Harty C Hooi DS Daykin M Williams P Telford G Pritchard DI Bycroft BW 《Journal of medicinal chemistry》2003,46(1):97-104
Comparative immune modulatory activity for a range of synthetic analogues of a Pseudomonas aeruginosa signal molecule, N-(3-oxododecanoyl)-l-homoserine lactone (3O, C(12)-HSL), is described. Twenty-four single or combination systematic alterations of the structural components of 3O, C(12)-HSL were introduced as described. Given the already defined immunological profile of the parent compound, 3O, C(12)-HSL, these compounds were assayed for their ability to inhibit murine and human leucocyte proliferation and TNF-alpha secretion by lipopolysaccharide (LPS) stimulated human leucocytes in order to provide an initial structure-activity profile. From IC(50) values obtained with a murine splenocyte proliferation assay, it is apparent that acylated l-homoserine lactones with an 11-13 C side chain containing either a 3-oxo or a 3-hydroxy group are optimal structures for immune suppressive activity. These derivatives of 3O, C(12)-HSL with monounsaturation and/or a terminal nonpolar substituent on the side chain were also potent immune suppressive agents. However, structures lacking the homoserine lactone ring, structures lacking the l-configuration at the chiral center, and those with polar substituents were essentially devoid of activity. The ability of compounds selected from the optimal activity range to modulate mitogen-driven human peripheral blood mononuclear cell proliferation and LPS-induced TNF-alpha secretion indicates the suitability of these compounds for further investigation in relation to their molecular mechanisms of action in TNF-alpha driven immunological diseases, particularly autoimmune diseases such as psoriasis, rheumatoid arthritis, and type 1 (autoimmune) diabetes. 相似文献