全文获取类型
收费全文 | 6670篇 |
免费 | 642篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 168篇 |
妇产科学 | 116篇 |
基础医学 | 829篇 |
口腔科学 | 544篇 |
临床医学 | 713篇 |
内科学 | 1301篇 |
皮肤病学 | 57篇 |
神经病学 | 571篇 |
特种医学 | 234篇 |
外科学 | 1038篇 |
综合类 | 147篇 |
一般理论 | 15篇 |
预防医学 | 637篇 |
眼科学 | 66篇 |
药学 | 502篇 |
中国医学 | 34篇 |
肿瘤学 | 345篇 |
出版年
2021年 | 97篇 |
2020年 | 68篇 |
2019年 | 106篇 |
2018年 | 118篇 |
2017年 | 94篇 |
2016年 | 98篇 |
2015年 | 114篇 |
2014年 | 186篇 |
2013年 | 256篇 |
2012年 | 306篇 |
2011年 | 408篇 |
2010年 | 216篇 |
2009年 | 169篇 |
2008年 | 335篇 |
2007年 | 412篇 |
2006年 | 387篇 |
2005年 | 344篇 |
2004年 | 305篇 |
2003年 | 318篇 |
2002年 | 305篇 |
2001年 | 131篇 |
2000年 | 153篇 |
1999年 | 114篇 |
1998年 | 93篇 |
1997年 | 74篇 |
1996年 | 74篇 |
1995年 | 71篇 |
1994年 | 49篇 |
1992年 | 97篇 |
1991年 | 75篇 |
1990年 | 91篇 |
1989年 | 64篇 |
1988年 | 81篇 |
1987年 | 75篇 |
1986年 | 84篇 |
1985年 | 69篇 |
1984年 | 70篇 |
1983年 | 72篇 |
1982年 | 52篇 |
1981年 | 48篇 |
1980年 | 41篇 |
1979年 | 45篇 |
1978年 | 61篇 |
1977年 | 59篇 |
1976年 | 39篇 |
1975年 | 46篇 |
1974年 | 48篇 |
1973年 | 41篇 |
1972年 | 52篇 |
1971年 | 41篇 |
排序方式: 共有7379条查询结果,搜索用时 46 毫秒
31.
Preliminary experience with new bioactive prosthetic material for repair of hernias in infected fields 总被引:15,自引:5,他引:10
Surgisis (Cook Surgical, Bloomington, Ind., USA) is a new four-ply bioactive, prosthetic mesh for hernia repair derived from
porcine small-intestinal submucosa. It is a naturally occurring extracellular matrix which is easily absorbed, supports early
and abundant new vessel growth, and serves as a template for the constructive remodeling of many tissues. As such, we believe
that Surgisis mesh is ideal for use in contaminated or potentially contaminated fields in which ventral, incisional, or inguinal
hernia repairs are required. From November 2000 through May 2002, 25 patients (11 male, 14 female) underwent placement of
Surgisis mesh for a variety of different hernia repairs. A total of 25 hernia repairs were performed in our patient population.
Fourteen procedures (56%) were performed in a potentially contaminated setting (i.e. with incarcerated/strangulated bowel
within the hernia or coincident with a laparoscopic cholecystectomy/colectomy). Eleven repairs (44%) were performed in a grossly
contaminated field, including one in which an infected polypropylene mesh from a previous inguinal hernia repair was replaced
with Surgisis and one in which necrotic bowel was discovered within the hernial sac. Median follow-up was 15 months with a
range of 1–20 months. Of the 25 total repairs, there was one wound infection complicated by enterocutaneous fistula in a patient
originally operated on for ischemic bowel. The fistula was in a location independent of the Surgisis mesh. There were no mesh-related
complications or recurrent hernias in our early postoperative follow-up period. Surgisis mesh appears to be a promising new
prosthetic material for hernia repair, especially in contaminated or potentially contaminated fields. Obviously, long-term
follow-up is still required.
Electronic Publication 相似文献
32.
33.
34.
Although pilomatrixomas are well known to dermatologists and dermatopathologists, surgeons encountering these lesions over the parotid gland frequently do not consider this benign neoplasm in the differential diagnosis. Presentation of a subcutaneous preauricular lesion, coupled with an erroneous cytologic diagnosis of malignancy, can potentially result in histologic "overdiagnosis" and more aggressive therapy than is required for these benign hair follicle neoplasms. A case is reported to illustrate this potential diagnostic trap, and a series of 206 cases collected at the University Hospital of Zurich from 1975 to 1987 is reviewed. 相似文献
35.
R A Franklin 《The Nursing clinics of North America》1992,27(3):631-642
Cigarette smoking remains a major health problem in not only the United States but the world. The dependency-producing effects of nicotine are well documented. Primary prevention, preventing the initiation of smoking, is receiving increased attention in the field of health education. Secondary prevention, smoking cessation, is showing promising results. Perhaps the goal of a smoke-free America by 2000 is not a "pipe dream" after all. 相似文献
36.
We compared results of comprehensive neuropsychological testing in 42 patients with clinically diagnosed Alzheimer's disease (AD) and in an equal number of patients with clinically definite chronic-progressive multiple sclerosis. Age, sex, and education were controlled using demographically corrected T scores based on a large normal sample. Both groups showed significant impairment on the test battery, but the degree of dementia was more severe in the patients with AD. A deviation score analysis, controlling for overall level of cognitive impairment, revealed significant differences between the groups. Alzheimer's disease was associated with relatively greater impairment of learning, memory, and verbal skills, whereas the MS group showed greater relative impairment of attention, incidental memory, and psychomotor functions. These data suggest that both the degree and pattern of mental impairement differ in patients with AD and patients with multiple sclerosis. Our results support a distinction between "gray matter" and "white matter" dementia, and may help clarify the issue of "cortical" vs "subcortical" dementia by demonstrating neuropsychological differences based on secure neuropathologic distinctions. 相似文献
37.
About 1000 persons seeking treatment for alcohol or drug dependence were asked, relative to cigarettes, about the difficulty of quitting the use of the substance for which they were seeking treatment, the strength of their strongest urges to use, and the pleasure they derived from use. Fifty-seven percent said that cigarettes would be harder to quit using than their problem substance. These ratings were related to the level of cigarette dependence and the perceived difficulty of quitting the use of the problem substance. The alcohol-dependent persons were about four times more likely than the drug-dependent persons to say that their strongest urges for cigarettes were at least as great as their strongest urges for their problem substance. Cigarettes were generally rated as less pleasurable than alcohol or other drugs. Thus, experiential experts on dependence judge cigarette dependence as at least as "addictive" as other drug use, but not as pleasurable, indicating important similarities and differences between cigarette dependence and other forms of dependence on psychoactive substances. 相似文献
38.
Analysis of orthologous gene expression between human pulmonary adenocarcinoma and a carcinogen-induced murine model
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stearman RS Dwyer-Nield L Zerbe L Blaine SA Chan Z Bunn PA Johnson GL Hirsch FR Merrick DT Franklin WA Baron AE Keith RL Nemenoff RA Malkinson AM Geraci MW 《The American journal of pathology》2005,167(6):1763-1775
Human adenocarcinoma (AC) is the most frequently diagnosed human lung cancer, and its absolute incidence is increasing dramatically. Compared to human lung AC, the A/J mouse-urethane model exhibits similar histological appearance and molecular changes. We examined the gene expression profiles of human and murine lung tissues (normal or AC) and compared the two species' datasets after aligning approximately 7500 orthologous genes. A list of 409 gene classifiers (P value <0.0001), common to both species (joint classifiers), showed significant, positive correlation in expression levels between the two species. A number of previously reported expression changes were recapitulated in both species, such as changes in glycolytic enzymes and cell-cycle proteins. Unexpectedly, joint classifiers in angiogenesis were uniformly down-regulated in tumor tissues. The eicosanoid pathway enzymes prostacyclin synthase (PGIS) and inducible prostaglandin E(2) synthase (PGES) were joint classifiers that showed opposite effects in lung AC (PGIS down-regulated; PGES up-regulated). Finally, tissue microarrays identified the same protein expression pattern for PGIS and PGES in 108 different non-small cell lung cancer biopsies, and the detection of PGIS had statistically significant prognostic value in patient survival. Thus, the A/J mouse-urethane model reflects significant molecular details of human lung AC, and comparison of changes in orthologous gene expression may provide novel insights into lung carcinogenesis. 相似文献
39.
Evaluation of three disk tests for identification of enterococci, leuconostocs, and pediococci. 总被引:2,自引:1,他引:2
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Simple rapid tests for presumptive identification of catalase-negative non-beta-hemolytic cocci (i.e., enterococci, leuconostocs, and pediococci) have not previously been available. Seven hundred thirty-four strains of aerobic and facultatively anaerobic, catalase-negative, non-beta-hemolytic gram-positive cocci were tested for susceptibility to vancomycin (Vans) by a screening procedure and production of leucine aminopeptidase (LAPase) and pyrrolidonylarylamidase (PYRase) in disk tests. Three unique patterns of activity in response to the three disks (30 micrograms of vancomycin, PYRase, and LAPase) can be used to presumptively identify the vancomycin-resistant (Vanr) enterococci (Vanr and PYRase and LAPase positive), leuconostocs (Vanr and PYRase and LAPase negative), and pediococci (Vanr, PYRase negative, and LAPase positive). The results indicate that, together with Gram stain characteristics and the catalase test, the vancomycin, LAPase, and PYRase disk tests can be used to presumptively identify Vanr strains of enterococci as well as Leuconostoc and Pediococcus strains from human infections. 相似文献
40.
D E Woods R Franklin S J Cryz Jr M Ganss M Peppler C Ewanowich 《Infection and immunity》1989,57(4):1018-1024
Considerable effort directed toward designing a safe and effective vaccine for Bordetella pertussis in which the cellular and/or acellular antigens necessary to confer immunity are known has been hampered by lack of information on the pathogenesis of the natural infection. The study presented here describes an animal model of lung infection by B. pertussis encased in agar beads in adult (200- to 220-g) male Sprague-Dawley rats. At 3 and 7 days after inoculation with phase I B. pertussis, organisms could be recovered from the lungs of rats; however, organisms were not recoverable at days 10 and 14 but reappeared in lung homogenates at day 21. Histopathological examination revealed findings similar to those seen in human disease. At day 3, a mild lymphocytic infiltrate was present in the bronchi, with progressive lymphoid hyperplasia peribronchially. By day 7, a necrotizing inflammation of the tracheobronchial mucous membranes, characterized by both mononuclear and polymorphonuclear cells, was noted. Phase III B. pertussis organisms were not recoverable from the lungs of inoculated rats at day 3 after inoculation, nor were histological changes noted in these animals. Clinical findings in phase I B. pertussis-infected rats included hypoglycemia, circulating lymphocytosis, and paroxysms in which air was forcibly expelled from the mouth or nose. 相似文献