全文获取类型
收费全文 | 1401篇 |
免费 | 183篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 83篇 |
妇产科学 | 58篇 |
基础医学 | 247篇 |
口腔科学 | 17篇 |
临床医学 | 144篇 |
内科学 | 292篇 |
皮肤病学 | 54篇 |
神经病学 | 136篇 |
特种医学 | 97篇 |
外科学 | 105篇 |
综合类 | 36篇 |
预防医学 | 158篇 |
眼科学 | 38篇 |
药学 | 101篇 |
中国医学 | 2篇 |
肿瘤学 | 76篇 |
出版年
2019年 | 13篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 12篇 |
2015年 | 16篇 |
2014年 | 31篇 |
2013年 | 35篇 |
2012年 | 29篇 |
2011年 | 35篇 |
2010年 | 40篇 |
2009年 | 50篇 |
2008年 | 58篇 |
2007年 | 82篇 |
2006年 | 55篇 |
2005年 | 63篇 |
2004年 | 46篇 |
2003年 | 36篇 |
2002年 | 41篇 |
2001年 | 59篇 |
2000年 | 50篇 |
1999年 | 48篇 |
1998年 | 45篇 |
1997年 | 46篇 |
1996年 | 33篇 |
1995年 | 25篇 |
1994年 | 43篇 |
1993年 | 37篇 |
1992年 | 41篇 |
1991年 | 33篇 |
1990年 | 18篇 |
1989年 | 45篇 |
1988年 | 39篇 |
1987年 | 41篇 |
1986年 | 28篇 |
1985年 | 32篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 23篇 |
1980年 | 18篇 |
1979年 | 12篇 |
1978年 | 23篇 |
1977年 | 15篇 |
1976年 | 18篇 |
1975年 | 20篇 |
1974年 | 9篇 |
1973年 | 15篇 |
1972年 | 8篇 |
1970年 | 15篇 |
1967年 | 9篇 |
排序方式: 共有1645条查询结果,搜索用时 15 毫秒
1.
R T Pham M Sung C R Dawson J Schachter 《Investigative ophthalmology & visual science》1990,31(7):1367-1373
The development and testing of candidate vaccines for trachoma are constrained because only humans and nonhuman primates are susceptible to conjunctival infection with Chlamydia trachomatis. Guinea pig inclusion conjunctivitis (GPIC), an analogous disease of guinea pigs, provides a useful, less expensive model to study ocular chlamydial infections. GPIC is caused by a Chlamydia psittaci strain whose external constituents are very similar to those of C. trachomatis. To develop a better model for studying GPIC immunity, conjunctival pockets were established under the abdominal skin of guinea pigs by subcutaneous implantation. Up to six implants could be produced in each animal. The success rate of implantation was 79.0% (n = 148). These pockets were then infected with GPIC. The organism was recovered from the autografts indicating local replication, and tests for serum antibody by microimmunofluorescence showed production of GPIC-specific antibody of IgG and IgM classes after infection. There was minimal antibody response after moderate inoculating doses to the implants, and the titers increased more slowly than after eye infection with GPIC; with higher concentration of the inoculum, however, the antibody response increased to the same levels as with the ocular challenge but more slowly. Inoculation of pockets with GPIC also produced acute inflammatory changes in infected autografts (n = 101). Histologic examination of infected grafts showed chlamydial inclusions in epithelial cells and significant infiltration with lymphocytes and polymorphonuclear cells. Subcutaneous autografts may provide a useful model for chronologic studies of chlamydial infection. The delayed immunologic response, however, suggests that these pockets of implanted epithelium do not have full access to the immune system. 相似文献
2.
E Zuskin Z Zagar E N Schachter J Mustajbegovic J Kern 《British journal of industrial medicine》1992,49(6):435-440
A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes. 相似文献
3.
4.
J Moncada J Schachter G Bolan J Nathan M A Shafer A Clark J Schwebke W Stamm T Mroczkowski Z Seliborska 《Diagnostic microbiology and infectious disease》1992,15(8):663-668
A newly developed microwell enzyme immunosorbent assay (EIA) system by Syva Company (Palo Alto, CA) can detect Chlamydia trachomatis in < 3 hr. It uses a polyclonal antibody to chlamydial lipopolysaccharide and end points are determined with a spectrophotometer. Three clinical trial sites (University of California Medical Center, San Francisco, CA; University of Washington, Seattle, WA; and Louisiana State University Medical Center, New Orleans, LA), compared this EIA with tissue culture (TC) for identifying Chlamydia in urogenital specimens. Overall prevalence by TC was 10.4% (136 of 1306). When tests were compared with TC (using vials or microtiter plates and a fluorescent antibody stain), we found an EIA sensitivity of 93.4% (127 of 136) and a specificity of 98.1% (1148 of 1170). This EIA has a performance profile that is, at the very least, comparable with other nonculture methods for diagnosing genital tract infections with C. trachomatis. 相似文献
5.
Balloon dacryocystoplasty: indications and contraindications 总被引:3,自引:0,他引:3
6.
Eugenija Zuskin E. Neil Schachter Bozica Kanceljak Jadranka Mustajbegovic Theodor J. Witek 《International archives of occupational and environmental health》1994,66(5):317-324
The relationship of skin reactivity and serum immunoglobulin E (IgE) levels to the prevalence of chronic respiratory symptoms and to ventilatory capacity is examined in workers exposed to different organic aerosols. The results from group of control workers similarly tested are also presented. Workers exposed to occupational allergens had positive skin tests more frequently than did controls, except for soy bean workers. Workers with positive skin tests to occupational allergens had a higher prevalence of almost all symptoms than those with negative skin tests although the differences did not always reach statistical significance. Workers with positive skin reactions in general had significantly higher serum IgE levels than did workers with negative skin reactions. There were across-shift reductions of ventilatory capacity in all groups of exposed workers, varying for forced vital capacity from 1.7% to 13.3%, for forced expiratory volume from 0.4%–21.9%, for maximum flow rates at 50% from 1.5% to 16.1% and for maximum flow rates at the last 25% of control vital capacity from 0% to 24.9%. There was, however, no correlation between acute and chronic lung function changes and skin reactivity or IgE values. Our data suggest that although exposure to organic aerosols may be associated with frequent immunologic reactions, these findings do not predict objective respiratory impairment.The research was supported in part by grant no. JBP 733 from the National Institutes of Health, Bethesda, Md., USA, and by grant no. RO1 OHO-2593-04 from the National Institutes of Occupational Safety and Health, Centers for Disease Control, Atlanta, Ga., USA 相似文献
7.
J Schachter A Pomeranz I Berger B Wolach 《The International journal of pediatric nephrology》1987,8(4):211-214
We report 4 cases of children who developed lobar pneumonia and subsequently acute glomerulonephritis, all within a period of six weeks. In one case streptococcus pneumonia type 5 was isolated, a strain not previously described in the literature as being nephritogenic. 相似文献
8.
E. Zuskin J. Mustajbegovic E. N. Schachter D. Pavicic A. Budak 《International archives of occupational and environmental health》1997,70(6):413-418
A follow-up investigation was performed on 49 female workers studied 2 years earlier in a vegetable-pickling plant. Acute
and chronic respiratory symptoms and ventilatory capacity measurements were recorded during the original and the follow-up
studies. Maximal expiratory flow-volume (MEFV) curves were recorded during the Monday morning work shift. The forced vital
capacity (FVC), 1-s forced expiratory volume (FEV1), and flow rates at 50% and the last 25% of the FVC (FEF50, FEF25) were
measured. There were small increases in the prevalence of chronic symptoms between the two studies for both smokers and nonsmokers,
but these did not reach statistical significance. Five workers at the time of the initial study had a diagnosis of occupational
asthma; only one of these was still working at the time of follow-up. Workers lost to the follow-up had lower lung function
than those seen at follow-up. In workers who were followed, larger than expected mean annual declines were noted for all ventilatory
capacity parameters in both smokers (FVC 0.070 l, FEV1 0.070 l; FEF50 0.355 l/s, FEF25 0.270 l/s) and nonsmokers (FVC 0.045
l, FEV1 0.045 l, FEF50 0.285 l/s; FEF25 0.130 l/s). The decrease was particularly pronounced for FEF50 and FEF25. The accelerated
decline in ventilatory capacity tests noted in the female nonsmokers suggests an independent effect on lung function of work
exposure in this environment. Our data confirm that work in the pickling industry, particularly in small, poorly regulated
plants, has deleterious effects on respiratory function.
Received: 24 September 1996 / Accepted: 19 June 1997 相似文献
9.
HM Clink 《Journal of clinical pathology》1980,33(8):799-800
10.