全文获取类型
收费全文 | 297157篇 |
免费 | 6602篇 |
国内免费 | 274篇 |
专业分类
耳鼻咽喉 | 3118篇 |
儿科学 | 10504篇 |
妇产科学 | 5604篇 |
基础医学 | 33000篇 |
口腔科学 | 5775篇 |
临床医学 | 19700篇 |
内科学 | 61511篇 |
皮肤病学 | 4682篇 |
神经病学 | 25929篇 |
特种医学 | 11666篇 |
外国民族医学 | 1篇 |
外科学 | 43910篇 |
综合类 | 2919篇 |
一般理论 | 37篇 |
预防医学 | 29890篇 |
眼科学 | 5522篇 |
药学 | 17807篇 |
中国医学 | 1238篇 |
肿瘤学 | 21220篇 |
出版年
2023年 | 797篇 |
2022年 | 487篇 |
2021年 | 2530篇 |
2020年 | 1264篇 |
2019年 | 2861篇 |
2018年 | 26398篇 |
2017年 | 19783篇 |
2016年 | 21733篇 |
2015年 | 3822篇 |
2014年 | 4096篇 |
2013年 | 5797篇 |
2012年 | 15852篇 |
2011年 | 30194篇 |
2010年 | 23205篇 |
2009年 | 14631篇 |
2008年 | 26837篇 |
2007年 | 29546篇 |
2006年 | 8162篇 |
2005年 | 9727篇 |
2004年 | 10047篇 |
2003年 | 10600篇 |
2002年 | 8379篇 |
2001年 | 4079篇 |
2000年 | 4839篇 |
1999年 | 3443篇 |
1998年 | 686篇 |
1997年 | 501篇 |
1996年 | 385篇 |
1995年 | 338篇 |
1994年 | 272篇 |
1992年 | 1292篇 |
1991年 | 1131篇 |
1990年 | 1047篇 |
1989年 | 836篇 |
1988年 | 685篇 |
1987年 | 658篇 |
1986年 | 634篇 |
1985年 | 552篇 |
1984年 | 406篇 |
1983年 | 316篇 |
1979年 | 333篇 |
1975年 | 272篇 |
1974年 | 332篇 |
1973年 | 350篇 |
1972年 | 289篇 |
1971年 | 310篇 |
1970年 | 309篇 |
1969年 | 312篇 |
1968年 | 283篇 |
1967年 | 241篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Short-term outcome analysis of a randomized study comparing laparoscopic vs open colectomy for colon cancer 总被引:19,自引:6,他引:13
A. M. Lacy J. C. García-Valdecasas J. M. Piqué S. Delgado E. Campo J. M. Bordas P. Taurá L. Grande J. Fuster J. L. Pacheco J. Visa 《Surgical endoscopy》1995,9(10):1101-1105
The authors examined the impact of the laparoscopic approach on the early outcome of resected colon carcinomas. The role of laparoscopic techniques in the treatment of colon carcinomas is questionable. Previous studies have suggested technical feasibility of surgical resections of these cancers by laparoscopic means and have implied a benefit to laparoscopic technique for patients undergoing colorectal resections. A prospective, randomized study was conducted comparing laparoscopic assisted colectomy (LAC) open colectomy (OC) for colon cancer. We present the preliminary results in relation to the short-term outcome and judge the feasibility of the laparoscopic procedure to as a way of performing accurate oncologic resection and staging. Benefit has been demonstrated with LAC in this setting. Passing flatus, oral intake, and discharge from hospital occurred earlier in LAC- than OC-treated patients The mean operative time was significantly longer in the LAC group than in the OC group. The overall morbidity was significantly lower in the LAC group. No significant differences were observed between both groups in the number of lymph nodes removed or the pathological stage following the Astler-Coller modification of the Dukes classification. The laparoscopic approach improves the short-term outcome of segmental colectomies for colon cancer. However, the further follow-up of these patients will allow us to answer in the near future whether or not the LAC may influence the long-term outcome.Presented at the annual meeting of the Society of American Gastrointestinal Surgeons (SAGES), Orlando, FL, USA, 11–14 March 1995 相似文献
992.
A. Muñoz-Hoyos I. Amorós-Rodríguez A. Molina-Carballo J. Uberos-Fernández D. Acuña-Castroviejo 《Journal of neural transmission (Vienna, Austria : 1996)》1996,103(7):833-842
Summary To characterize the pineal response to pyridoxine, plasma melatonin was measured in one hundred and twenty children 3 hours after vitamin B6 administration. The children, aged between 1.5 and 8 years, were divided in four groups as follows: a) control day group, grouping 27 children sampled at 9:00 and at 12:00; b) control night group, grouping 29 children sampled at 21:00 and at 24:00; c) pyridoxine day group, grouping 30 children sampled at 9:00, then intravenously (i.v.) injected with 3mg/kg of pyridoxine, and sampled at 12:00; and d) pyridoxine night group, grouping 34 children sampled at 21:00, i.v. injected with 3mg/kg of pyridoxine, and sampled at 24:00. Melatonin concentration was measured by radioimmuno assay. The data obtained showed a significant increase in melatonin levels after pyridoxine administration in the pyridoxine night group (39.87 ± 8.02pg/ml basal vs 88.45 ± 9.21 pg/ml after pyridoxine, p < 0.001). The other groups did not showed significant differences in melatonin concentrations. Statistical analysis shows that the administration of pyridoxine during the nocturnal hours represents a stimulating factor to increase the pineal production of melatonin in children. 相似文献
993.
T Z Seísembekov M A Aliiakparov N S Umbetalina D E Finaeva L S Ospanova 《Terapevticheski? arkhiv》1988,60(6):16-18
Screening tests including the questionnaire method, urine analysis and radiorenography were used during mass screening of 1330 students. Comparison of the results of the first two methods showed a good informative value of the questionnaire method for the detection of pathology of the kidneys and urinary tracts. Radiorenography performed in 106 students with the detected nephrological symptom complex (risk group) revealed some changes practically in every other "risk group" student. 相似文献
994.
Heredia García Carlos Dante García Calderon Pedro Antonio 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1988,226(5):428-430
One hundred patients with retinal detachment (61 primary operations and 39 reoperations) were studied for titers of autoantibodies to human retinal S antigen using the enzyme-linked immunosorbent assay technique (ELISA). There was no statistically significant difference when comparing the group of patients with primary retinal detachment with the control group. However, a statistically significant increase in anti-S titers was recorded when a comparison was made between the group of reoperated patients and the control group (2,P < 0.001) and between the group of reoperated subjects and the group of patients operated on for the first time (2,P < 0.005).Presented at the XVth Meeting of the Club Jules Gonin, Copenhagen, 10–15 August 1986 相似文献
995.
996.
997.
Z Frühbauer J Pokorny D Zítová J Sykora M Zást?ra 《Ceskoslovenská epidemiologie, mikrobiologie, imunologie》1990,39(6):327-334
Between reactions assessing one class of immunoglobulins and reactions detecting all serum immunoglobulins comprehensively such as CFT, there is, as might be expected, a very poor quantitative correlation and thus in individual sera the result of one reaction cannot be reliably added to the result of another (CFT:ELISA/IgG). Even the correlation between reactions focused on the same Ig class (ELISA/IgG: IFT/IgG) is no better. Among reactions assessing specific IgM we consider ELISA/IgM better than IFT/IgM because there is not the risk of false negativity caused by concurrence of IgG. A combination of ELISA/IgG and ELISA/IgM gives good results as a statistical group: the distribution of results revealed agglomerations of sera corresponding to the assumed age of the infection derived from the generally accepted pattern of antibody formation. The applicability of the combination of these two reactions alone for evaluation of individual sera is a promising procedure but awaits further confirmation. Long-term investigations revealed within two years after infection a marked decline of CFT antibodies in the majority of cases but it was not sufficiently clear in ELISA/IgG. Despite the technical advantages of ELISA reactions, elimination af the CFT reaction is not foreseen in the near future. As the minimal combination of methods which provides adequate information we may consider at the present time CFT for assessment of total antibodies and ELISA/IgM for more marked differentiation of the acute stage. Evaluation of the lowest CFR titres considered hitherto as "practically negative" must be obviously revised in subjects with immunosuppression and organ donors for transplantation.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
998.
V Mícková 《Ceskoslovenská epidemiologie, mikrobiologie, imunologie》1990,39(4):222-227
The paper deals with the incidence of Yersiniae in pork and beef, focused in particular on the prevalence of Yersinia enterocolitica, serovar 3, biovar 4. The author uses for detection the method of cold shock, alkalization of the sample, taking advantage of the tolerance of Yersinias of diluted alkalis and suppressing the contaminating microflora, and the the selective medium CIN agar with a locally manufactured supplement. Cultivation was either direct or after propagation in phosphate buffer pH 7.6. The authors isolated 84 strains of Yersinias, i.e. 60% of the total number of examined specimens. Four strains were Yersinia enterocolitica, serovar 03, biovar 4 from pork by direct cultivation. Twenty strains did not agglutinate with commercial serum O-Yersinia IMUNA; they were included in the group "Yersinia enterocolitica other biovars" and 60 strains were "Environmental Yersinia isolates". The author proved a seasonal incidence of Yersinie enterocolitica, serovar 03, biovar 4. The applied method of detection and the the selective medium CIN agar with supplement proved suitable. It is important to respect hygienic provisions during processing in the slaughterhouse with regard to the high incidence of environmental Yersinias and the possible incidence of pathogenic serovars of Yersinias. 相似文献
999.
The purpose of this paper is to carry out an analysis of the term leukoplakia since its introduction in 1877 and to expose the most accepted concepts and present classification within specialists. For this purpose attention will be paid to definitions established in the international seminary developed in Malm? City, Sweden, in June 1983. A group of observations on present status of research and diagnostic methods and its limitations to pre-establish when a lesion of this type is going to evolve toward malignancy, is included. An important part of this paper is devoted to the linguistic analysis of leukoplakia and leukoplasia expressions. An extensive argumentation demonstrating the systematic impropriety in the Spanish Language of translating the English term "leukoplakia as leukoplasia, is presented. There is in Spanish the accurate translation, given by the expression leukoplakia, which is not only the adequate one for the exactness of its translation but also the one more conceptually adjusted to contemporary definition universally accepted, that is to say, a white plaque. Finally, a comment on importance of incorporates to our language the exact translation of scientific words, not only to fit it to present science, but also to a better fulfillment of its function in allowing the communication within Latin American researches themselves and with the world scientific community, is exposed. 相似文献
1000.
Compared with conventional, routine blood pressure measurement in the outpatient department of a hospital, 24-hour blood pressure monitoring provides more comprehensive information about blood pressure values in day-to-day life of the hypertensive patient. The hospital setting with all its stimuli affects the hypertensive patients so that their values will be statistically significantly higher compared with normal ones. Recent years have seen the introduction into clinical practice of self-monitoring by the patients themselves. Comparison of these three methods for blood pressure measurements revealed that self-monitoring may provide fairly accurate values comparable with those obtained by the "standard method", i.e., 24-hour monitoring. In view of the low variability of the mean value of blood pressure over a period of several days, self-monitoring can be employed in groups of selected outpatients on long-term follow-up. 相似文献