全文获取类型
收费全文 | 2268篇 |
免费 | 208篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 94篇 |
妇产科学 | 71篇 |
基础医学 | 294篇 |
口腔科学 | 45篇 |
临床医学 | 230篇 |
内科学 | 481篇 |
皮肤病学 | 19篇 |
神经病学 | 253篇 |
特种医学 | 115篇 |
外科学 | 283篇 |
综合类 | 78篇 |
一般理论 | 3篇 |
预防医学 | 220篇 |
眼科学 | 40篇 |
药学 | 120篇 |
中国医学 | 4篇 |
肿瘤学 | 104篇 |
出版年
2022年 | 23篇 |
2021年 | 50篇 |
2020年 | 28篇 |
2019年 | 38篇 |
2018年 | 49篇 |
2017年 | 34篇 |
2016年 | 49篇 |
2015年 | 50篇 |
2014年 | 58篇 |
2013年 | 83篇 |
2012年 | 118篇 |
2011年 | 122篇 |
2010年 | 70篇 |
2009年 | 53篇 |
2008年 | 123篇 |
2007年 | 92篇 |
2006年 | 100篇 |
2005年 | 101篇 |
2004年 | 83篇 |
2003年 | 56篇 |
2002年 | 103篇 |
2001年 | 82篇 |
2000年 | 63篇 |
1999年 | 64篇 |
1998年 | 21篇 |
1997年 | 15篇 |
1996年 | 21篇 |
1995年 | 19篇 |
1994年 | 22篇 |
1992年 | 49篇 |
1991年 | 43篇 |
1990年 | 30篇 |
1989年 | 39篇 |
1988年 | 37篇 |
1987年 | 30篇 |
1986年 | 29篇 |
1985年 | 29篇 |
1984年 | 27篇 |
1983年 | 36篇 |
1981年 | 22篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 20篇 |
1977年 | 23篇 |
1976年 | 24篇 |
1974年 | 20篇 |
1972年 | 24篇 |
1971年 | 18篇 |
1969年 | 15篇 |
1967年 | 14篇 |
排序方式: 共有2478条查询结果,搜索用时 15 毫秒
11.
K Kontou-Karakitsos J E Salvaggio K P Mathews 《The Journal of allergy and clinical immunology》1975,55(4):241-248
Based on sensitization following intranasal antigen administration, previous investigations have suggested greater absorption of allergens through the nasal mucous membranes of atopic than of nonatopic subjects. In this study mucosal absorption was assessed more directly by determining the capacity of allergens applied intranasally to elicit cutaneous Prausnitz-Küstner (P-K) reactions in nonatopic persons as compared with asymptomatic atopic subjects sensitive to other allergens. Two series of reaginic human serum dilutions were injected intracutaneously in recipients backs, and 48 hours later one series was challenged intracutaneously with test allergen. After the responses had been recorded, concentrated allergenic extract was sprayed into the nose and the second series of P-K sites observed for reactivity. Sometimes these P-K sites were rechallenged intracutaneously the following day to determine passive transfer neutralization. Two allergens were studied: bovine ribonuclease (RNase) and peanut extract. Two sera containing peanut reagins and one with RNase antibodies were each used in 10 to 11 atopic and 9 to 11 nonatopic recipients. The atopic group failed to show greater or more rapid absorption of either allergen through the nose based on the highest serum dilution reacting after nasal challenge. the speed of the reaction, the ratio of the titer by nasal challenge to the intracutaneous titer, or passive transfer neutralization. Controls showed that the results were not influenced by systemic absorption of allergen employed for intracutaneous tests. Drinking the amount of peanut extract applied intranasally did not elicit P-K reactions. 相似文献
12.
G R Istre K Kreiss R S Hopkins G R Healy M Benziger T M Canfield P Dickinson T R Englert R C Compton H M Mathews R A Simmons 《The New England journal of medicine》1982,307(6):339-342
From June 1978 through December 1980, at least 36 cases of amebiasis occurred in persons who had had colonic-irrigation therapy at a chiropractic clinic in western Colorado. Of 10 persons who required colectomy, six did. Of 176 persons who had been to the clinic in the last four months of 1980, 80 had received other forms of treatment. Twenty-one per cent of the colonic-irrigation group had bloody diarrhea, as compared with 1 per cent of the non-irrigation group (P = 0.00013). Thirty-seven per cent of the colonic-irrigation group who submitted specimens had evidence of amebic infection on either stool examination or serum titer, as compared with 2.4 per cent in the non-irrigation group (P = 0.00012). Persons who were given colonic irrigation immediately after a person with bloody diarrhea received it were at the highest risk for the development of amebiasis. Tests of the colonic-irrigation machine after routine cleaning showed heavy contamination with fecal coliform bacteria. The severity of disease in this outbreak may have been related to the route of inoculation. 相似文献
13.
14.
Though much research about the public's views of scientists, genetic research and its moral, ethical, and social implications exists, little has been done to investigate how scientists view their own role(s) in public discussions and policy formation related to genetic research and technologies. We interviewed 20 academic geneticists in the United States about their perceptions of the roles they and others (e.g., professional societies, the public, ethicists, and elected officials) do and should play in the formation of science policy, the communication of science to the public, and the public discussions of moral and ethical issues raised by scientific advances. The participants in our study thought that scientists should be more actively involved in public outreach and science policy formation, but frequently they felt ill-equipped and unsupported by their peers and institutions to pursue these activities. Furthermore, many were skeptical of or did not trust elected officials--who they consider uninformed about the issues and too driven by political agendas--to formulate sound science policy. They do, however, have faith in the ability of scientific societies to influence policy effectively, and some thought that societies should play a larger role, both in science policy and as a liaison between scientists and the public. Finally, participants offered suggestions for increasing the involvement and influence of scientists in science-policy formation and public discourse. 相似文献
15.
Single-tube mixed agglutination test for the detection of staphylococcal protein A. 总被引:2,自引:6,他引:2 下载免费PDF全文
A simple, rapid mixed agglutination test using sheep erythrocytes (SRBC) sensitized with rabbit hemolysin and intact viable staphylococci is described for the detection of bound staphylococcal protein A. Soluble protein A was heat extracted from 50 clinical isolates as well as the Cowan I and Wood 46 strains of Staphylococcus aureus and titered by a hemagglutination test using sensitized SRBC and dilutions of soluble protein A. Protein A could be detected in all of these supernatants including that of S. aureus Wood 46, a strain generally considered to be protein A negative. These organisms were later retested by the mixed agglutination test and even those staphylococcal isolates expressing very low heat-extractable soluble protein A concentrations (1:2 titers) were positive, confirming the sensitivity of the test. In a screen of clinical isolates, only 4 of 235 (1.8%) coagulase-positive isolates were negative in the mixed agglutination test. Of 25 coagulase-negative isolates, none yielded a positive reaction. 相似文献
16.
R. Lange P. Rowe L. Seebauer J. Mathews J. R. Siewert W. Silen 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1984,364(1):539-539
Zusammenfassung Der Mechanismus der Cytoprotektion von Prostaglandin (PG) auf die Magenmucosa ist unbekannt. Anaesthesierte Kaninchen erhielten in der Gruppe (GR) I (n=8) im. Aspirin (ASA) (100 mg/kg als Bolus, 66 mg/kg/h kontinuierlich) in der GR 11 (n=10) NaCI und in der GR III (n=7) zusätzlich zum ASA, PGE I (0,1 g/kg/min) als Infusion über 120 min. Der Mucosa-Blutfluß (MBF) wurde mit radioaktiven Mikrosphären gemessen. In der GR I fiel der MBF nach 15 min um 72,3+3,8% (+ SEM) und nach 120 min um 73,1+3,8% (p 0,05 gegen % Änderung in GR II und III). Nach 120 min zeigte sich in der GR I 19,8 + 7,6% der Fundusmucosa hämorrhagisch, in der GR 11 6,1 +5,2% und in der GR 1112,0+ 1,4% (p 0,05 gegen GR II und III). Wir schließen, daß der cytoprotektive Effekt des PGE I auf einer Aufhebung der ASA bedingten Mucosaischämie beruht. 相似文献
17.
Andrea Lin Jasmine A. Mack Brittany Bruggeman Laura M. Jacobsen Amanda L. Posgai Clive H. Wasserfall Todd M. Brusko Mark A. Atkinson Stephen E. Gitelman Peter A. Gottlieb Matthew J. Gurka Clayton E. Mathews Desmond A. Schatz Michael J. Haller 《Diabetes》2021,70(5):1123
Previously, we demonstrated low-dose antithymocyte globulin (ATG) and granulocyte colony-stimulating factor (GCSF) immunotherapy preserved C-peptide for 2 years in a pilot study of patients with established type 1 diabetes (n = 25). Here, we evaluated the long-term outcomes of ATG/GCSF in study participants with 5 years of available follow-up data (n = 15). The primary end point was area under the curve (AUC) C-peptide during a 2-h mixed-meal tolerance test. After 5 years, there were no statistically significant differences in AUC C-peptide when comparing those who received ATG/GCSF versus placebo (P = 0.41). A modeling framework based on mean trajectories in C-peptide AUC over 5 years, accounting for differing trends between groups, was applied to recategorize responders (n = 9) and nonresponders (n = 7). ATG/GCSF reponders demonstrated nearly unchanged HbA1c over 5 years (mean [95% CI] adjusted change 0.29% [–0.69%, 1.27%]), but the study was not powered for comparisons against nonresponders 1.75% (–0.57%, 4.06%) or placebo recipients 1.44% (0.21%, 2.66%). These data underscore the importance of long-term follow-up in previous and ongoing phase 2 trials of low-dose ATG in recent-onset type 1 diabetes. 相似文献
18.
A strategy for reducing maternal mortality 总被引:3,自引:0,他引:3
Suleiman AB Mathews A Jegasothy R Ali R Kandiah N 《Bulletin of the World Health Organization》1999,77(2):190-193
A confidential system of enquiry into maternal mortality was introduced in Malaysia in 1991. The methods used and the findings obtained up to 1994 are reported below and an outline is given of the resulting recommendations and actions. 相似文献
19.
20.
PURPOSE: The development of adequate bladder capacity is not ensured in all patients with bladder exstrophy despite successful bladder closure and reconstruction. To determine the factors leading to the development and maturation of the exstrophic bladder we created a large animal model of exstrophy. We compared biopsies obtained from a cohort of experimentally induced exstrophic neonatal sheep bladders to those of normal control bladders and related the findings to a previously reported comparison of human neonatal normal and exstrophic bladders. MATERIALS AND METHODS: Bladder specimens of 7 newborn lambs with experimentally induced exstrophy were compared to specimens of 10 newborn control lamb bladders. All specimens were stained with Masson's trichrome as well as with specific monoclonal antibodies to types I and III collagen. Stained sections were then analyzed using a morphometric image analysis system to quantify the amounts of smooth muscle and collagen present. RESULTS: A significant increase in the ratio of collagen-to-smooth muscle was noted in exstrophic versus normal control bladders (p <0.05). This difference was similar to that in the previous study of neonatal human bladders. There was no significant difference in the ratios of types I and III collagen in the 2 groups of sheep bladders. This finding is different from that reported in the previous human studies. CONCLUSIONS: Overall changes in the ratio of smooth muscle-to-collagen in the sheep exstrophy model are similar to those in humans. However, the differences in collagen types I and III do not seem to be present. 相似文献