全文获取类型
收费全文 | 530354篇 |
免费 | 27562篇 |
国内免费 | 496篇 |
专业分类
耳鼻咽喉 | 6681篇 |
儿科学 | 16924篇 |
妇产科学 | 12543篇 |
基础医学 | 92682篇 |
口腔科学 | 12351篇 |
临床医学 | 48509篇 |
内科学 | 95460篇 |
皮肤病学 | 11869篇 |
神经病学 | 34078篇 |
特种医学 | 19758篇 |
外国民族医学 | 53篇 |
外科学 | 78072篇 |
综合类 | 7610篇 |
现状与发展 | 2篇 |
一般理论 | 107篇 |
预防医学 | 38545篇 |
眼科学 | 11944篇 |
药学 | 41451篇 |
1篇 | |
中国医学 | 1126篇 |
肿瘤学 | 28646篇 |
出版年
2021年 | 3899篇 |
2018年 | 5736篇 |
2017年 | 4131篇 |
2016年 | 4878篇 |
2015年 | 5366篇 |
2014年 | 7125篇 |
2013年 | 10505篇 |
2012年 | 15585篇 |
2011年 | 17403篇 |
2010年 | 9959篇 |
2009年 | 8825篇 |
2008年 | 15729篇 |
2007年 | 17466篇 |
2006年 | 16961篇 |
2005年 | 16273篇 |
2004年 | 15895篇 |
2003年 | 15279篇 |
2002年 | 14795篇 |
2001年 | 22442篇 |
2000年 | 22982篇 |
1999年 | 18933篇 |
1998年 | 5237篇 |
1997年 | 4367篇 |
1996年 | 4400篇 |
1995年 | 4125篇 |
1992年 | 14415篇 |
1991年 | 15821篇 |
1990年 | 15950篇 |
1989年 | 15626篇 |
1988年 | 14308篇 |
1987年 | 14198篇 |
1986年 | 13169篇 |
1985年 | 12686篇 |
1984年 | 9396篇 |
1983年 | 8001篇 |
1982年 | 4177篇 |
1979年 | 8937篇 |
1978年 | 6383篇 |
1977年 | 5149篇 |
1976年 | 5504篇 |
1975年 | 6613篇 |
1974年 | 7419篇 |
1973年 | 7159篇 |
1972年 | 6597篇 |
1971年 | 6309篇 |
1970年 | 5887篇 |
1969年 | 5467篇 |
1968年 | 5161篇 |
1967年 | 4621篇 |
1966年 | 3963篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Electroencephalographic and imaging profile in a subacute sclerosing panencephalitis (SSPE) cohort: a correlative study. 总被引:1,自引:0,他引:1
S Praveen-kumar S Sinha A B Taly S Jayasree V Ravi J Vijayan S Ravishankar 《Clinical neurophysiology》2007,118(9):1947-1954
OBJECTIVE: There are only a few studies correlating diverse radiological and EEG features of subacute sclerosing panencephalitis (SSPE). The objective of the study was to (a) describe EEG profile and (b) correlate it with the clinical and imaging data of patients with confirmed SSPE. METHODS: This study was conducted at a University teaching hospital in south India and involved 58 patients (M:F=37:21, age: 12.3, SD 4.8 years) of SSPE. Diagnosis of SSPE was based on the characteristic clinical manifestations, and raised IgG (1:625) anti-measles antibody in cerebrospinal fluid (CSF) by ELISA in all the patients. Scalp EEGs were recorded on 16 channel machines using standard parameters and procedures. The EEG, clinical and imaging data were reviewed. RESULTS: EEGs were frequently abnormal: typical (37) and atypical (21). Diffuse slowing of background activity (BGA) was noted in 46 records being asymmetrical in six. Periodic complexes were periodic (32), quasi-periodic (21) or a-periodic (4). Periodic complexes (PC) (amplitude: 370.7, SD 171.2 microV; duration - 1.7, SD 2.0 s; inter-complex interval: 8.4, SD 9.2s) were symmetrical in 39 and asymmetrical in 19. CT (32) and MRI (23) scans were normal in 16 patients while others had white matter (15), cerebral edema (8), cerebral atrophy (8), basal ganglia (2), and thalamic (2) changes. There was an independent association of frontally dominant slowing of BGA (p=0.04) and typical PCs (p=0.03) with the diffuse cerebral edema on imaging. White matter changes correlated with slowing of BGA (p=0.04), but not with typical PC (p=0.16). CONCLUSIONS: This study provides valuable insight into the structural and clinical correlates of EEG changes in SSPE. SIGNIFICANCE: Irrespective of the incidence of occurrence of SSPE in a community, a clinician should be aware of the wide spectra of EEG findings. This study also discusses the possible underlying structural and clinical correlates. 相似文献
83.
Hale Sayan V Haktan Ozacmak Aysel Guven R Gulhan Aktas I Diler Ozacmak 《Journal of investigative surgery》2006,19(3):163-173
Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, malondialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area. 相似文献
84.
Transcapillary fluid balance consequences of missing initial lymphatics studied in a mouse model of primary lymphoedema 总被引:1,自引:0,他引:1
Tine V. Karlsen Marika J. Karkkainen Kari Alitalo Helge Wiig 《The Journal of physiology》2006,574(2):583-596
To investigate the phenotypic consequences of a deranged lymphangiogenesis in relation to tissue fluid accumulation and the possible role of inflammation in the pathogenesis of lymphoedema, we measured determinants of transcapillary fluid filtration and inflammatory mediators in the interstitial fluid in genetically engineered Chy mice, a model for primary congenital lymphoedema (Milroy's disease). Although initial lymphatics were not present in dermis in any of the areas studied (fore paw, hind paw, thigh and back skin) interstitial fluid pressure ( P if ), measured with micropipettes, and tissue fluid volumes were significantly increased only in the areas with visible swelling – the fore and hind paw, whereas interstitial colloid osmotic pressure (COPif ) was increased in all the skin areas examined. A volume load of 15% of body weight resulted in a more pronounced increase in P if as well as a four-fold increase in interstitial fluid volume in Chy relative to wild-type (wt) mice, showing the quantitative importance of lymphatics for fluid homeostasis during acute perturbations. A similar level of proinflammatory markers in interstitial fluid in early established lymphoedema (3–4 months) in Chy and wt suggests that inflammation does not have a major pathogenetic role for the development of lymphoedema, whereas a reduced level of the immunomodulatory cytokine interleukin (IL)-4 may result in a reduced immunological defence ability and thus lead to the increase in inflammatory cytokines IL-2 and IL-6 observed at a later stage (11–13 months). Our data suggest that primary lymphoedema results in a high interstitial fluid protein concentration that does not induce an interstitial inflammatory reaction per se , and furthermore shows the paramount importance of the initial lymphatics in tissue fluid homeostasis, especially during perturbations of transcapillary fluid balance. 相似文献
85.
I. V. Shilova E. A. Krasnov E. I. Korotkova M. G. Nagaev A. N. Lukina 《Pharmaceutical Chemistry Journal》2006,40(12):660-662
Extracts of the above-ground part of meadowsweet (Filipendula ulmaria L. Maxim.) demonstrate a pronounced antioxidant activity. It is established that 70% and 95% ethanol extracts contain the
most active substances. Investigation of the chemical composition of the above-ground part of the plant and its 70% ethanol
extract by means of qualitative reactions, thin-layer chromatography, and paper chromatography showed the presence of various
phenolic compounds, including quercetin and its glycosides, dihydroquercetin, apigenin, rododendrol, esculetin, and m-hydroxybenzoic, salicylic, anisic, gallic, gentisic, ferulic, chlorogenic, and caffeic acids.
__________
Translated From Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 12, Pp. 22–24, December, 2006. 相似文献
86.
Pankaj Dabir Snehal Dabir B V Siva Prasad M V R Reddy 《Infection, genetics and evolution》2006,6(4):287-291
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response. 相似文献
87.
88.
89.
OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4. 相似文献
90.
S. V. Terent’eva E. N. Komarova T. N. Sapozhnikova A. T. Teplyakov E. A. Ivanovskaya T. I. Andreeva 《Pharmaceutical Chemistry Journal》2006,40(12):694-696
A rapid procedure for determining angiotensin II in the blood by inverse voltammetry using a TA-2 device (Tekhnoanalit Company,
Tomsk) with a graphite electrode has been developed. The results of analyses using the proposed technique agree with the clinical
data. The rapid analytical procedure favors optimization of cardiotropic drug therapy.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 12, pp. 54–56, December, 2006. 相似文献