全文获取类型
收费全文 | 9606篇 |
免费 | 683篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 207篇 |
儿科学 | 313篇 |
妇产科学 | 192篇 |
基础医学 | 1318篇 |
口腔科学 | 222篇 |
临床医学 | 906篇 |
内科学 | 2200篇 |
皮肤病学 | 186篇 |
神经病学 | 864篇 |
特种医学 | 502篇 |
外国民族医学 | 1篇 |
外科学 | 1421篇 |
综合类 | 109篇 |
一般理论 | 3篇 |
预防医学 | 643篇 |
眼科学 | 166篇 |
药学 | 623篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 455篇 |
出版年
2021年 | 80篇 |
2019年 | 100篇 |
2018年 | 104篇 |
2017年 | 92篇 |
2016年 | 107篇 |
2015年 | 131篇 |
2014年 | 174篇 |
2013年 | 277篇 |
2012年 | 381篇 |
2011年 | 362篇 |
2010年 | 222篇 |
2009年 | 220篇 |
2008年 | 344篇 |
2007年 | 398篇 |
2006年 | 421篇 |
2005年 | 393篇 |
2004年 | 411篇 |
2003年 | 347篇 |
2002年 | 308篇 |
2001年 | 355篇 |
2000年 | 339篇 |
1999年 | 304篇 |
1998年 | 116篇 |
1997年 | 109篇 |
1996年 | 96篇 |
1995年 | 88篇 |
1992年 | 218篇 |
1991年 | 212篇 |
1990年 | 199篇 |
1989年 | 258篇 |
1988年 | 211篇 |
1987年 | 194篇 |
1986年 | 200篇 |
1985年 | 205篇 |
1984年 | 136篇 |
1983年 | 153篇 |
1982年 | 90篇 |
1981年 | 87篇 |
1980年 | 88篇 |
1979年 | 152篇 |
1978年 | 96篇 |
1977年 | 82篇 |
1976年 | 83篇 |
1975年 | 80篇 |
1974年 | 89篇 |
1973年 | 79篇 |
1972年 | 84篇 |
1971年 | 82篇 |
1970年 | 78篇 |
1969年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
41.
42.
Miranda Jeanne James J. Gross Jacqueline B. Persons Judy Hahn 《Cognitive therapy and research》1998,22(4):363-376
Cognitive theory holds that dysfunctionalattitudes are important risk factors for depression.Critics have questioned this view, noting that, althoughdysfunctional attitudes are elevated in depression, they are not evident in vulnerable individualswho are asymptomatic. To deal with this criticism,Miranda and Persons (1988) have advanced the mood-statedependent hypothesis, which suggests that cognitive vulnerability factors are indeed present invulnerable individuals, but remain dormant untilactivated by negative mood. To test this hypothesis, 33women with and 67 women without histories of depression reported dysfunctional attitudes before andafter a film negative mood induction. As predicted,vulnerable subjects who reported increased negative moodreported increased dysfunctional attitudes.Unexpectedly, nonvulnerable subjects who reported increasednegative mood reported decreased dysfunctionalattitudes. These findings support the mood-statedependent hypothesis, and suggest that a deficit in theability to regulate negative emotions may be animportant feature of vulnerability todepression. 相似文献
43.
Low‐income urban parents of color enrolled in a parent training study were interviewed to understand what motivated their participation and what led 30% of them to subsequently drop out. Most enrolled because they wanted to be better parents. Most dropped out because of time and schedule constraints. Retention was higher when parents' motivations for participation matched program goals. Program location and qualities of the recruiter were cited most often as important; financial compensation was cited least often as important. 相似文献
44.
Head injury mortality in two centers with different emergency medical services and intensive care 总被引:7,自引:0,他引:7
A R Colohan W M Alves C R Gross J C Torner V S Mehta P N Tandon J A Jane 《Journal of neurosurgery》1989,71(2):202-207
The authors report data collected prospectively on 551 cases of head injury in New Delhi, India, and 822 cases in Charlottesville, Virginia. The mortality rate, adjusted for initial severity of injury, was 11.0% in New Delhi versus 7.2% in Charlottesville (p less than 0.02). There was a striking similarity in mortality rates at both centers when comparing patients with the least severe head injuries and those with the most severe injuries according to the motor score of the Glasgow Coma Scale (GCS M). However, in the group with an abnormal but purposeful motor response (GCS M = 5), the mortality rate was 12.5% in New Delhi versus 4.8% in Charlottesville (p less than 0.01). The relative absence of prehospital emergency care and the delay in admission after head injury in New Delhi are cited as two possible causes for the differences in mortality rates in this subgroup of patients with "moderate" head injuries. 相似文献
45.
46.
Hartmut Kirchheim Rainer Gross 《Pflügers Archiv : European journal of physiology》1970,315(2):159-172
Zusammenfassung An 15 Bastardhunden wurde der Einfluß einer Na-Pentobarbital-Narkose sowei einer zusätzlichen chirurgischen Präparation auf die Ruhewerte von Blutdruck und Nierendurchblutung und deren Änderung nach doppelseitigem Carotisverschluß im Vergleich zum wachen Tier untersucht.Barbiturat-Injektion (30 mg/kg i.v.) allein erhöhte die Herzfrequenz, den systolischen und diastolischen Blutdruck, änderte jedoch nicht die mittlere Nierendurchblutung. Zusätzliche chirurgische Präparation verstärkte diese Veränderungen mit Ausnahme vom systolischen Blutdruck und der Nierendurchblutung.Bei Carotisverschuluß kam es im steady state zu einer vermehrten reflektorischen Herzfrequenzsteigerung nach Barbiturat-Injektion sowie nach Barbiturat mit chirurgischer Präparation. In Barbiturat-Narkose stieg der mittlere Blutdruck stärker an als am wachen Tier; diese Veränderung war nach chirurgischer Präparation noch deutlicher ausgeprägt. Die mittlere Nierendurchblutung wurde im steady state in keiner der 3 Gruppen signifikant verändert. Der reflektorische Herzfrequenz- und Blutdruckanstieg erfolgte im Wachzustand rascher als nach Barbiturat und Barbiturat mit chirurgischem Trauma. Unter letzteren Bedingungen fehlte auch das im Wachzustand beobachtete Unterschießen der Herzfrequenz nach Öffnen der Carotismanschetten. Der druckpassive overshoot der Nierendurchblutung am wachen Tier fehlte sowohl nach Barbiturat als auch nach zusätzlicher chirurgischer Präparation.Die Ergebnisse zeigen, daß der mit Na-Pentobarbitural narkotisierte und der narkotisierte, akut operierte Hund gegenüber dem Wachzustand betreffend der Ruhewerte und der reflektorischen Veränderungen der Herzfrequenz und des Blutdrucks im steady state des Carotissinus-Reflexes zwei quantitativ unterschiedlich reagierende Kreilaufpräparate liefert. Gemessen an der Beseitigung sowohl der raschen Herzfrequenz- und Blutdruckveränderungen als auch des phasischen Einschwingvorganges der Nierendurchblutung durch Narkose und Narkose mit Trauma unterscheiden sich solche Präparate auch qualitativ vom Wachzustand.Mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
47.
A long-term outbreak of urinary tract-associated multiply resistant Providencia stuartii occurred in a large medical facility that included a 513-bed chronic care unit. The unique characteristics of this outbreak were that from within a single medical facility, P. stuartii with multiple serotypes, biotypes, and antibiograms could be identified. The organisms isolated had five different biotypes, seven different antibiograms, and two major serotypes. All of the organisms were susceptible to amikacin, cefamandole, and cefoxitin. Application of standard infection control measures impeded the spread of this outbreak, and it slowly terminated 16 months later. 相似文献
48.
Nitric oxide participates in the intestinal pathology associated with murine syngeneic graft-versus-host disease 总被引:5,自引:0,他引:5
Flanagan DM Jennings CD Goes SW Caywood BE Gross R Kaplan AM Bryson JS 《Journal of leukocyte biology》2002,72(4):762-768
Syngeneic graft-versus-host disease (SGVHD) develops following lethal irradiation, reconstitution with syngeneic bone marrow, and treatment with a short course of cyclosporin A (CsA) therapy. The disease is characterized by the development of a T helper cell type 1-like cytokine response [interleukin (IL)-12, interferon-gamma (IFN-gamma), and tumor necrosis factor alpha], and macrophage activation is central to development of the syndrome. It has been shown that nitric oxide (NO) participates significantly in the development of allogeneic GVHD. Studies were initiated to determine if NO participates in the pathology associated with SGVHD. Significant increases in inducible NO synthase (iNOS) mRNA and circulating NO were found in the tissues of SGVHD versus control animals. Treatment of SGVHD animals with the iNOS inhibitor aminoguanidine (AG) reversed the pathology associated with this disease. Furthermore, AG treatment reduced the production of IL-12 and IFN-gamma mRNA in the colons of CsA-treated mice. These studies demonstrate that NO participates in the pathological processes that are associated with the development of murine SGVHD. 相似文献
49.
J Brunton D Hinde C Langston R Gross B Rowe M Gurwith 《Journal of clinical microbiology》1980,11(4):343-348
During epidemiological studies carried out in urban and rural areas of the midwestern Canadian province of Manitoba, we cultured enterotoxigenic Escherichia coli (ETEC) from 16 (1.7%) of 945 diarrheal stools and 4 (0.3%) of 1,282 normal stools. ETEC was found in not more than 2.3% of diarrheal stools obtained from any population during any season. Diarrhea associated with ETEC persisted for a mean of 9 days. Two children were dehydrated and required intravenous fluid therapy, and one adult suffered a cholera-like syndrome. Half of the children required hospitalization for management of their diarrhea. Two adults and two children who harbored ETEC were completely asymptomatic. The pattern of toxin production correlated with serotype and the serotypes encountered were (with a few exceptions) similar to those found in other areas. We conclude that ETEC is an uncommon cause of diarrhea, both in rural and urban areas of central Canada. However, the possibility that ETEC might cause severe sporadic cases or epidemics of gastroenteritis remains. 相似文献
50.
Differentiation between mouse-virulent and -avirulent strains of Toxoplasma gondii by a monoclonal antibody recognizing a 27-kilodalton antigen. 总被引:1,自引:1,他引:1 下载免费PDF全文
Using a murine monoclonal antibody, we were able to differentiate between mouse-virulent and -avirulent strains of Toxoplasma gondii. Monoclonal antibody TB6G5 was reactive with eight clinical mouse-avirulent isolates but not with mouse-virulent laboratory strains RH and BK. The antibody-reactive antigen was identified by indirect immunofluorescence and immunoblot as a 27-kDa cytoplasmic protein expressed by tachyzoites as well as by bradyzoites. 相似文献