全文获取类型
收费全文 | 75545篇 |
免费 | 5199篇 |
国内免费 | 227篇 |
专业分类
耳鼻咽喉 | 888篇 |
儿科学 | 2037篇 |
妇产科学 | 1820篇 |
基础医学 | 12264篇 |
口腔科学 | 1882篇 |
临床医学 | 6950篇 |
内科学 | 15984篇 |
皮肤病学 | 1059篇 |
神经病学 | 7080篇 |
特种医学 | 3189篇 |
外国民族医学 | 45篇 |
外科学 | 9828篇 |
综合类 | 612篇 |
一般理论 | 88篇 |
预防医学 | 5533篇 |
眼科学 | 1336篇 |
药学 | 5126篇 |
中国医学 | 207篇 |
肿瘤学 | 5043篇 |
出版年
2022年 | 614篇 |
2021年 | 1295篇 |
2020年 | 785篇 |
2019年 | 1123篇 |
2018年 | 1391篇 |
2017年 | 999篇 |
2016年 | 1186篇 |
2015年 | 1362篇 |
2014年 | 1754篇 |
2013年 | 2864篇 |
2012年 | 3880篇 |
2011年 | 4001篇 |
2010年 | 2724篇 |
2009年 | 2313篇 |
2008年 | 3616篇 |
2007年 | 3820篇 |
2006年 | 3736篇 |
2005年 | 3587篇 |
2004年 | 3548篇 |
2003年 | 3314篇 |
2002年 | 3301篇 |
2001年 | 2265篇 |
2000年 | 2312篇 |
1999年 | 2102篇 |
1998年 | 1024篇 |
1997年 | 833篇 |
1996年 | 732篇 |
1995年 | 747篇 |
1994年 | 615篇 |
1993年 | 655篇 |
1992年 | 1488篇 |
1991年 | 1462篇 |
1990年 | 1377篇 |
1989年 | 1365篇 |
1988年 | 1146篇 |
1987年 | 1139篇 |
1986年 | 1077篇 |
1985年 | 991篇 |
1984年 | 734篇 |
1983年 | 688篇 |
1982年 | 497篇 |
1981年 | 477篇 |
1980年 | 397篇 |
1979年 | 636篇 |
1978年 | 389篇 |
1977年 | 373篇 |
1975年 | 384篇 |
1974年 | 432篇 |
1973年 | 367篇 |
1972年 | 351篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Background
The mitogen-activated protein kinases, MAPKs for short, constitute cascades of signalling pathways involved in the regulation of several cellular processes that include cell proliferation, differentiation and motility. They also intervene in neurological processes like fear conditioning and memory. Since little remains known about the MAPK-Activated Protein Kinase, MAPKAPK5, we constructed the first MAPKAPK knockin mouse model, using a constitutive active variant of MAPKAPK5 and analyzed the resulting mice for changes in anxiety-related behaviour. 相似文献72.
R. I. Mustafin A. A. Protasova G. Van den Mooter V. A. Kemenova 《Pharmaceutical Chemistry Journal》2005,39(12):663-666
With a view to the development of new controlled drug delivery systems, the formation of an interpolyelectrolyte complex (IPEC)
between chitosan (CTS) and Eudragit L100 (L-100) has been studied. The structure of this IPEC is such that two maxima are
observed in the curves of IPEC swelling in the media with different pH values. The release of a model drug (ibuprofen) from
IPEC-based tablets is significantly retarded, and this delay can be controlled by changing the molecular weight of CTS in
the IPEC composition.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 12, pp. 44–46, December, 2005. 相似文献
73.
Intractable tinnitus can lead to serious consequences. Study evidence indicates that the central nervous system is involved in generation and maintenance of chronic tinnitus and that tinnitus and other neurologic symptoms such as chronic pain may share similar mechanisms. Brain ablation and stimulation are used to treat chronic pain with success. Recent studies showed that ablation and stimulation in non-auditory areas resulted in tinnitus improvement. Deep brain stimulation (DBS) may be an alternative treatment for intractable tinnitus and deserves further study. 相似文献
74.
Barbara Bruemmer Author Vitae Jeffrey HarrisAuthor Vitae Phil GleasonAuthor Vitae Carol J. BousheyAuthor Vitae Patricia M. SheeanAuthor Vitae Sujata ArcherAuthor Vitae Linda Van HornAuthor Vitae 《Journal of the American Dietetic Association》2009,109(10):1728-1737
The use of epidemiologic research designs and analytical methods is common in dietetics research. Food and nutrition professionals who seek to perform evidence-based practice or participate in research design, analysis, and communication need skills in the essentials of epidemiology. This is one of a series of monographs on research methodology that addresses these needs and supports the goals of the Board of Editors of the Journal of the American Dietetic Association to further enhance competency and skills. This monograph focuses on statistical approaches for univariate analyses used with the primary observational study designs associated with epidemiology. Tables illustrating the presentation and interpretation of these results are included. 相似文献
75.
Conclusion We would like to stress that we do not necessarily consider AC for SPECT MPI to be unfeasible or unworthy of scientific pursuit;
indeed, a great deal of creative scientific effort has been poured into this area of investigation over the past 3 decades,
and much of it has contributed to a better understanding of the physics, as well as the clinical aspects, of our field. However,
the great variety of available AC hardware and software “flavors,” the historical pattern of commercial release of insufficiently
validated AC implementations, and the increasingly clouded health care reimbursement horizon may have created an environment
where the envisioned users of the technology have been desensitized and discouraged from expecting it to ever come to fruition
in a standardized, validated, and costeffective form.
It has been reported as recently as 2005 that the “entire base of SPECT cameras has only 5% of systems with attenuation correction.”8
Perhaps the reports of AC’s demise are exaggerated, but it certainly seems as if the people have spoken and, after readying
themselves for the wolf one too many times, have come to the conclusion that “the future (of AC) ain’t what it used to be”
. . .at least not yet. 相似文献
76.
Sabine J Presser Guido Schumacher Ruth Neuhaus Peter Thuss-Patience Jens Stieler Peter Neuhaus 《Liver transplantation》2007,13(3):443-450
The purpose of the study was to determine the incidence, risk factors, treatment, and influence on survival of patients with de novo esophageal cancer after liver transplantation (LT). From 1988 to 2006, 1,926 patients underwent LT in our institution. A total of 9 patients (0.5%) developed a de novo esophageal cancer and 1 patient a cancer of the cardia (0.05%). A retrospective analysis was performed to reveal underlying diseases, timeframes between LT and appearance of cancer, predisposing factors, cancer therapy, complications, immunosuppressive regimens, and survival. Of our 10 patients, 7 (70%) suffered from esophageal squamous cell carcinoma (SCC) and 3 patients (30%) developed an adenocarcinoma, including the patient with cancer of the cardia. A total of 9 patients were transplanted due to alcoholic cirrhosis; 1 patient suffered from hepatocellular carcinoma in nonA-nonB hepatitis-related cirrhosis. Median time to tumor diagnosis was 51 months after transplantation. A total of 5 patients were treated conservatively with combined radiochemotherapy and 5 underwent surgical resection. Patients with radiochemotherapy showed a mean survival of 14.8 months vs. 24.8 months for the patients of the surgery group. No major postoperative complication has been observed. A total of 2 patients of the surgery group are still alive after a follow-up of 15 and 89 months. In conclusion, de novo esophageal and cancer of the cardia after LT is a rare event. In spite of immunosuppression, no increased complication rate has been observed. Patients may have a survival benefit from surgical resection. 相似文献
77.
78.
79.
The effect of diaper type and overclothing on fecal contamination in day-care centers 总被引:2,自引:0,他引:2
Fecal coliform contamination of environmental surfaces and hands in the day-care center is common. This study evaluated the effect of two diaper types on fecal contamination. Ten rooms in four day-care centers containing 141 children were studied in a prospective, randomized, crossover study. A total of 2946 samples were cultured during the 9-week study. Fecal coliforms were isolated from 307 inanimate objects (15%), 73 toy balls (46%), and 131 hands (17%). The number of contaminated inanimate objects was significantly less in rooms where paper diapers were worn when compared with that in rooms where double cloth diapers with plastic overpants were worn and in rooms where clothes were worn over diapers. Inanimate object cultures had more contamination in rooms in which diarrhea had occurred. Containment of feces by overclothes and diaper type may be important in decreasing transmission of enteric pathogens in day-care environments. 相似文献
80.