全文获取类型
收费全文 | 1159篇 |
免费 | 41篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 18篇 |
妇产科学 | 65篇 |
基础医学 | 103篇 |
口腔科学 | 35篇 |
临床医学 | 127篇 |
内科学 | 207篇 |
皮肤病学 | 63篇 |
神经病学 | 49篇 |
特种医学 | 25篇 |
外科学 | 154篇 |
综合类 | 42篇 |
一般理论 | 6篇 |
预防医学 | 155篇 |
眼科学 | 16篇 |
药学 | 102篇 |
肿瘤学 | 18篇 |
出版年
2017年 | 8篇 |
2015年 | 7篇 |
2013年 | 21篇 |
2012年 | 6篇 |
2010年 | 17篇 |
2009年 | 20篇 |
2006年 | 7篇 |
2001年 | 13篇 |
1999年 | 14篇 |
1998年 | 28篇 |
1997年 | 54篇 |
1996年 | 59篇 |
1995年 | 39篇 |
1994年 | 36篇 |
1993年 | 32篇 |
1992年 | 24篇 |
1991年 | 19篇 |
1990年 | 31篇 |
1989年 | 31篇 |
1988年 | 23篇 |
1987年 | 33篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 29篇 |
1983年 | 25篇 |
1982年 | 16篇 |
1981年 | 19篇 |
1980年 | 16篇 |
1979年 | 24篇 |
1978年 | 15篇 |
1977年 | 19篇 |
1976年 | 19篇 |
1974年 | 11篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 9篇 |
1970年 | 6篇 |
1969年 | 5篇 |
1963年 | 7篇 |
1961年 | 7篇 |
1960年 | 5篇 |
1959年 | 35篇 |
1958年 | 57篇 |
1957年 | 45篇 |
1956年 | 50篇 |
1955年 | 45篇 |
1954年 | 33篇 |
1949年 | 30篇 |
1948年 | 38篇 |
1946年 | 5篇 |
排序方式: 共有1202条查询结果,搜索用时 15 毫秒
1.
ANDREW A. AMOSCATO GEORGE F. BABCOCK R. MICHAEL SRAMKOSKI BARBARA A. HYND J. WESLEY ALEXANDER 《Chemical biology & drug design》1987,29(2):177-186
This study reports on the synthesis of two fluorescent analogues of thymopentin (TP-5; Arg-Lys-Asp-Val-Tyr). A fluorescein isothiocyanate labeled analogue (FITC-TP-5) and a stilbene isothiocyanate labeled analogue (SITS-TP-5) were extensively purified by ion-exchange and gel filtration chromatography. Characterization of the coupling site through amino acid analysis, dansylation and N-terminal cleavage of the fluorescent amino acid yielded results which indicated that both were mono-labeled analogues derivatized at the N-terminal. These analogues were shown to be TP-5-like in nature by their ability to induce the expression of the Thy 1.2 surface marker on nude mouse prothymocytes in both in vivo and in vitro assays. In addition, these analogues were able to inhibit the specific binding of radiolabeled TP-5 to human lymphocytes. Initial studies describing the interaction of FITC-TP-5 with human lymphocytes are shown. 相似文献
2.
3.
GLORIA L. KLEIN MS RD KIMBERLY KITA JUDITH FISH MMSc RD BARBARA SINKUS RN GORDON L. JENSEN MD PhD 《Journal of the American Dietetic Association》1997,97(8):885-888
Health care services and resources for older persons living in rural areas may be highly variable, and integrated service-delivery models are often lacking. This article presents a managed-care model of nutrition risk screening and intervention for older persons in rural areas. Nutrition risk screening was implemented by the Geisinger Health Care System, Danville, Pa, to target all eligible enrollees in a regional Medicare risk program. A single remote clinic site participating in the managed health care system was chosen for further study of a linked screening and case-management effort for undernourished persons. Screening and intervention at the clinic site selected for this study were guided by centralized expertise and resources. Individualized evaluation and intervention plans were developed with the aid of a dietitian and implemented by the clinic case manager. Of the 417 subjects who completed screening at the remote site, 68 met the risk criteria for undernutrition and were selected for case management. Many of the targeted persons received interventions that included evaluations by a physician or physician extender (eg, physician assistant, nurse practitioner) at the clinic and consultations with nutrition, mental health, or social services professionals. Twenty-six of the subjects who took part in the intervention completed a follow-up screening 6 months later. Ten of those persons no longer exhibited risk criteria. This demonstrates the feasibility of a linked screening and case management program for nutrition risk in the managed-care setting. J Am Diet Assoc. 1997; 97: 885-888. 相似文献
4.
A. BELLUZZI C. BRIGNOLA M. CAMPIERI P. GIONCHETTI F. RIZZELLO S. BOSCHI S. CUNANNE M. MIGLIOLI & L. BARBARA 《Alimentary pharmacology & therapeutics》1994,8(1):127-130
Patients with Crohn's disease may become zinc-deficient and, in such patients, an altered metabolism of radiolabelled long-chain fatty acids has been reported. We have investigated the possible reversal by zinc supplementation of altered long-chain fatty acid profiles of red cells in Crohn's disease. Twenty patients with long-standing Crohn's disease in clinical remission received 200 mg of zinc sulphate daily for 6 weeks. Phospholipid fatty acid profiles of washed red cells were analysed before and after zinc treatment and compared to those of 20 unsupplemented healthy controls. Plasma zinc levels in Crohn's were 72 ± 8 μg/dL before zinc treatment and increased to 114 ± 10 μg/dl after the therapy. Prior to zinc supplementation, the percentage of palmitic, stearic and oleic acids was significantly higher in Crohn's disease, while linoleic, arachidonic and n-3 fatty acids were reduced in Crohn's disease compared to healthy controls. Zinc supplementation abolished these pre-treatment differences in red-cell long-chain fatty acid profiles but did not affect plasma fatty acid values. Further studies are needed to clarify whether these fatty acid changes can be related to the clinical course of the disease. 相似文献
5.
P. GIONCHETTI M. CAMPIERI A. BELLUZZI S. BOSCHI C. BRIGNOLA M. MIGLIOLI L. BARBARA 《Alimentary pharmacology & therapeutics》1994,8(5):535-540
Aims: An oral multiparticulate coated formulation of 5-aminosalicylic acid (5-ASA; mesalazine) has been developed to provide a controlled release of the drug, in a pH-dependent fashion, in the distal ileum and colon. The purpose of the present study was to assess the systemic availability of the drug and its metabolite, acetyl-5-ASA, following single (800 mg) and multiple (2400 mg for 56 days) oral dose administration. Methods: Three groups were investigated: six healthy volunteers, six patients with ulcerative colitis, and nine patients with Crohn's disease in remission. In the single oral dose study (800 mg) all three groups participated, whereas in the multiple oral dose study (2400 mg/day for 56 days) only the patients with inflammatory bowel disease took part. Plasma and urine 5-ASA and Ac-5-ASA were measured for 48 h. Results: In the single oral dose regimen, systemic absorption of 5-ASA and Ac-5-ASA were low and did not differ between the three groups. Only about 20% of the 5-ASA given was absorbed, with more than 80% of the drug being available in the terminal ileum and colon for therapeutic activity. The multiple oral dose regimen in patients with inflammatory bowel disease produced a significantly higher plasma concentration and urine excretion of both 5-ASA and Ac-5-ASA by the end of the treatment, in comparison to the first dose. There was a statistically higher systemic absorption of 5-ASA in patients with ulcerative colitis than in patients with Crohn's disease. After 56 days of dosing, no adverse event was reported and laboratory screening tests remained within normal ranges. Conclusions: The new oral 5-ASA formulation is gradually released throughout the small and large intestine, reflected by a low plasma concentration of the drug and its metabolite, with about 80% of the drug being available for ileum-colon therapeutic activity. 相似文献
6.
C. R. B. BECKMANN F.W. LING BARBARA M. BARZANSKY R.D. EDEN B. WAXMAN 《Medical education》1990,24(3):224-229
Many factors have led to a movement from the emphasis of the 1960s and 1970s on departmental expansion towards an emphasis on cost-effective undergraduate medical education emphasizing the 'art' as well as the 'science' of medicine. In January 1985 a questionnaire was sent under the auspices of the Undergraduate Education Committee of the Association of Professors of Obstetrics and Gynecology to all chairmen of departments of obstetrics and gynecology in the USA and Canada seeking their opinions about these trends and information about the educational programmes in their departments. The information from this study indicates that the chairmen are aware of and responding to this new direction in medical education. A stabilization of teaching staff and clerkship sizes and the emphasis on clinical as well as cognitive evaluation, despite recognition of the cost of the former, shows active interventions towards these ends. An emphasis on education in 'basic' as compared to 'subspecialty' areas which is independent of the subspecialty of the academic chairman also supports this trend. 相似文献
7.
Andrew BOFINGER Justin WESTHUYZEN David SALTISSI Colleen MORGAN Helen HEALY 《Nephrology (Carlton, Vic.)》1997,3(2):169-177
Summary: Uraemic dyslipidaemia is a major risk factor for cardiovascular disease in end-stage renal failure patients. In patients without renal failure, high levels and qualitative abnormalities of low-density lipoprotein (LDL) are known to be atherogenic. Recently, LDL subfraction analysis has associated premature coronary artery disease with a high prevalence of small, dense LDL particles characterizing the LDL subclass phenotype B. We therefore examined the lipid profiles, LDL subfraction distribution and phenotypes in our population of haemodialysis (HD; n = 30) and peritoneal dialysis patients (PD; n = 17), and compared them to 40 asymptomatic, non-uraemic volunteers. Dialysis patients had significantly higher triglyceride and VLDL cholesterol concentrations and lower HDL cholesterol and smaller LDL peak particle diameters. PD patients had significantly higher total cholesterol, glycated haemoglobin and fasting blood glucose levels with smaller LDL peak particle diameters (24.4 [0.1] vs 24.8 [0.1 nm] than HD. Both groups showed significant negative correlations between plasma triglyceride and LDL peak particle diameter, and positive correlations between HDL cholesterol and LDL peak particle diameter. All the PD patients expressed the B phenotype (LDL peak diameter ± 25.5 nm) compared to 73% of HD patients. This study demonstrates that HD and especially PD patients have atherogenic lipid profiles which are associated with a predominance of small dense LDL particles and the highly atherogenic LDL subclass phenotype B. 相似文献
8.
BARBARA A. LEGGETT RUSSELL J. COLLINS W. GRAHAM E. COOKSLEY ROGER L. PRENTICE LAWRIE W. POWELL 《Journal of gastroenterology and hepatology》1987,2(3):205-211
The aim of this study was to determine if the Crithidia luciliae assay for auto-antibodies to double-stranded DNA, often positive in systemic lupus erythematosus, is always negative in auto-immune chronic active hepatitis (CAH) as has recently been suggested. Twenty-five patients were identified as having auto-immune CAH. Mean duration of follow-up was 10.5 years. Antinuclear antibodies were detected in 92%, smooth muscle antibodies in 76% and antimitochondrial antibodies in 16%. Antibodies to double-stranded DNA were detected by the Crithidia assay in four patients (16%). Two of these patients had positive tests on only one occasion and no features of systemic lupus erythematosus. In the other two the assay was persistently positive. During follow-up both developed arthritis and serositis but the liver lesion remained the dominant clinical feature. It was concluded that there is significant serological overlap between auto-immune CAH and systemic lupus erythematosus making the Crithidia assay unreliable in distinguishing between them. 相似文献
9.
10.
N. KUMAR GOGNA GRAEME MORGAN KATE DOWNS KERRY ATKINSON JAMES BIGGS 《Journal of Medical Imaging and Radiation Oncology》1992,36(4):317-320
The effect of dose rate to the lungs and development of interstitial pneumonitis (IP) was evaluated in 114 bone marrow transplant patients receiving fractionated total body irradiation (TBI) (1200 rads TD in 6 fractions twice daily over 3 days) as part of their pre-conditioning regimen. The tumour dose (TD) was calculated as the mean lung dose as previously described (1). A 6MV linear accelerator at a mid-line dose rate of 7.5 rads/minute was used between March 1981 and June 1985 and a Co-60 source at 5 rads/minute thereafter. This resulted in a range of dose rates to the lung of between 6.9 and 8.9 rads/minute and 2.9 and 6.5 rads/minute respectively. In the majority of patients the aetiology of IP was investigated by lung biopsy with histology and culture. There was no statistically significant difference in the incidence of IP over the two sets of dose rates. Our study suggests tat the incidence of IP using fractionated TBI is not influenced by dose rates below 8.9 rads per minute. 相似文献