全文获取类型
收费全文 | 19613篇 |
免费 | 1275篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 186篇 |
儿科学 | 510篇 |
妇产科学 | 408篇 |
基础医学 | 2196篇 |
口腔科学 | 328篇 |
临床医学 | 1636篇 |
内科学 | 4181篇 |
皮肤病学 | 252篇 |
神经病学 | 1044篇 |
特种医学 | 574篇 |
外科学 | 3537篇 |
综合类 | 659篇 |
一般理论 | 18篇 |
预防医学 | 1492篇 |
眼科学 | 580篇 |
药学 | 1883篇 |
中国医学 | 224篇 |
肿瘤学 | 1261篇 |
出版年
2023年 | 179篇 |
2022年 | 541篇 |
2021年 | 708篇 |
2020年 | 439篇 |
2019年 | 567篇 |
2018年 | 665篇 |
2017年 | 466篇 |
2016年 | 389篇 |
2015年 | 532篇 |
2014年 | 742篇 |
2013年 | 919篇 |
2012年 | 1345篇 |
2011年 | 1333篇 |
2010年 | 773篇 |
2009年 | 605篇 |
2008年 | 1062篇 |
2007年 | 1054篇 |
2006年 | 979篇 |
2005年 | 903篇 |
2004年 | 839篇 |
2003年 | 727篇 |
2002年 | 617篇 |
2001年 | 565篇 |
2000年 | 511篇 |
1999年 | 413篇 |
1998年 | 152篇 |
1997年 | 119篇 |
1996年 | 113篇 |
1995年 | 121篇 |
1994年 | 62篇 |
1993年 | 77篇 |
1992年 | 206篇 |
1991年 | 191篇 |
1990年 | 168篇 |
1989年 | 172篇 |
1988年 | 134篇 |
1987年 | 159篇 |
1986年 | 133篇 |
1985年 | 134篇 |
1984年 | 115篇 |
1983年 | 87篇 |
1982年 | 63篇 |
1981年 | 61篇 |
1979年 | 101篇 |
1978年 | 65篇 |
1977年 | 68篇 |
1975年 | 60篇 |
1974年 | 52篇 |
1973年 | 54篇 |
1972年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Comorbidities in head and neck cancer: agreement between self-report and chart review. 总被引:1,自引:1,他引:0
Shraddha S Mukerji Sonia A Duffy Karen E Fowler Mumtaz Khan David L Ronis Jeffrey E Terrell 《Otolaryngology--head and neck surgery》2007,136(4):536-542
OBJECTIVES: To determine the accuracy of self-reported comorbidities compared with medical record review and the clinical and sociodemographic characteristics associated with accuracy of self-reported comorbidities. STUDY DESIGN: We conducted a prospective study of 458 newly diagnosed head and neck cancer patients using self-administered questionnaire and medical chart review data. Overall and itemwise consistency between self-report and chart review was evaluated. Social, clinical, and demographic characteristics of consistent versus inconsistent responders were analyzed. RESULTS: Seventy-four percent of patients had at least one comorbidity. There was good overall consistency between self-report and chart review (kappa = 0.50). Compared with consistent responders, inconsistent responders were found to be older (P < 0.05), have lower sleep (P < 0.05) and physical activity scores (P < 0.05), be more depressed (P < 0.05), and have more severe comorbidities (P < 0.05). CONCLUSIONS AND SIGNIFICANCE: Self-report may be considered as an alternative to chart review for comorbidity assessment in head and neck cancer patients. Younger patients, those with good general health, fewer depressive symptoms, and mild comorbidities, are more likely to give responses consistent with chart review. 相似文献
72.
Seema Khan Smita Singhal Tarun Mathur Dilip J Upadhyay Ashok Rattan 《Nippon Ishinkin Gakkai Zasshi》2007,48(3):109-113
Disulfiram, an alcohol antagonistic drug has been on the market since 1949 with 80% bioavailability and an established safety profile. Recently it has been reported as a P-glycoprotein efflux pump modulator. Herein we report its antifungal potential. The MIC50 and MIC90 of disulfiram for yeast isolates is 4 and 8 microg/ml, respectively, and the MIC range is 1-16 micro g/ml for both fluconazole sensitive and resistant strains. Interestingly, disulfiram also showed fungicidal activity on Aspergillus spp. with MIC50 and MIC90 of 2 and 8 microg/ml, respectively. 相似文献
73.
Tension development in response to direct and indirect electrical stimulation was studied in an isolated phrenic nerve hemidiaphragm preparation of the mouse. β-Endorphin (β-EP) caused an increase in the preparation of the mouse. β-Endorphin (β-EP) caused an increase in the response to low frequency stimulation of the nerve. Upon direct stimulation of the muscle the peptide had no effect. The actions of β-EP were abolished in the presence of the opioid antagonist naloxone and mimicked by β opioid agonists. Upon high frequency stimulation of the nerve, β-EP caused an increase in the initial, maximum, and mean tension. It also prevented the fall in the final tension seen in the control preparations with repeated periods of stimulation. The findings are consistent with β-EP having a role to improve neuromuscular function and deley fatigue, and indicate the possible therapeutic potential of opioid substances in conditions where muscle weakness is present. © John Wiley & Sons, Inc. 相似文献
74.
75.
Schimpf PP Jamieson PM Khan MA Wagner RB 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》1988,15(1):49-51
After sustaining a free rupture of the intrapericardial ascending aorta secondary to blunt chest trauma, a 27-year-old man underwent successful aortic repair. To our knowledge, this is the first time a patient has ever survived this condition. Pericardial tamponade-together with rapid transport to the hospital and an aggressive surgical approach-was a key to the recovery of effective cardiac function and successful aortic repair. Although the patient succumbed to complications 74 days after surgery, this case illustrates the possibility of longterm survival after free rupture of the ascending aorta. The following report emphasizes the technical feasibility of controlling the perforated aortic root in such cases. 相似文献
76.
77.
Bensafi M Porter J Pouliot S Mainland J Johnson B Zelano C Young N Bremner E Aframian D Khan R Sobel N 《Nature neuroscience》2003,6(11):1142-1144
Neural representations created in the absence of external sensory stimuli are referred to as imagery, and such representations may be augmented by reenactment of sensorimotor processes. We measured nasal airflow in human subjects while they imagined sights, sounds and smells, and only during olfactory imagery did subjects spontaneously enact the motor component of olfaction--that is, they sniffed. Moreover, as in perception, imagery of pleasant odors involved larger sniffs than imagery of unpleasant odors, suggesting that the act of sniffing has a functional role in creating of olfactory percepts. 相似文献
78.
Immunosuppression with cis-Platinum (II) Diammino-dichloride: Effect on Antibody Plaque-Forming Spleen Cells 下载免费PDF全文
A new antitumor compound, cis-platinum (II) diamminodichloride, suppressed antibody plaque-forming cells in C(3)H mice when given in a single dose of 10 mg per kg of body weight within 2 days before or after sensitization. 相似文献
79.
San Román M Lezama L Rojas E Colina R García L Carlos A Khan B Cristina J 《Archives of virology》2002,147(11):2239-2246
Hepatitis C virus (HCV) has high genomic variability and at least six different types have been reported. The genotypes distribution is currently unknown among HCV strains circulating in Central America. In order to study the degree of genetic variability of strains isolated in Costa Rica, sequence data obtained from the 5' non coding region from 7 patients from Costa Rica were compared with published sequences from 57 strains of all types. The phylogenetic analysis revealed the existence of type 1 strains of a novel genetic lineage, recently described for some South American countries, and indicates an increasing diversification of HCV. 相似文献
80.
Regulation of the immune response: II. Further studies on differences in ability of F(ab′)2 and 7S antibodies to inhibit an antibody response 下载免费PDF全文
The ability of F(ab′)2 antibody preparations to suppress an immune response is much less than that of intact 7S antibody. The activity possessed by F(ab′)2 preparations withstood repurification procedures, hence contamination with intact 7S antibody is unlikely. Daily or thrice daily injections of antibody did not make equal the suppressive activities of F(ab′)2 and intact antibody, indicating that rapid excretion of F(ab′)2 antibody is not the sole factor involved in the difference in immunosuppressive potency between intact 7S and F(ab′)2 antibody. Some possibilities for distinct differences in the mechanism of the immuno-suppressive action of F(ab′)2 and 7S antibodies are raised and discussed. 相似文献