全文获取类型
收费全文 | 9245篇 |
免费 | 542篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 264篇 |
妇产科学 | 220篇 |
基础医学 | 1390篇 |
口腔科学 | 282篇 |
临床医学 | 964篇 |
内科学 | 2026篇 |
皮肤病学 | 173篇 |
神经病学 | 1043篇 |
特种医学 | 194篇 |
外科学 | 669篇 |
综合类 | 40篇 |
一般理论 | 3篇 |
预防医学 | 796篇 |
眼科学 | 149篇 |
药学 | 670篇 |
1篇 | |
中国医学 | 13篇 |
肿瘤学 | 883篇 |
出版年
2024年 | 32篇 |
2023年 | 104篇 |
2022年 | 215篇 |
2021年 | 323篇 |
2020年 | 218篇 |
2019年 | 227篇 |
2018年 | 265篇 |
2017年 | 206篇 |
2016年 | 259篇 |
2015年 | 292篇 |
2014年 | 408篇 |
2013年 | 529篇 |
2012年 | 711篇 |
2011年 | 737篇 |
2010年 | 379篇 |
2009年 | 340篇 |
2008年 | 609篇 |
2007年 | 663篇 |
2006年 | 610篇 |
2005年 | 527篇 |
2004年 | 509篇 |
2003年 | 462篇 |
2002年 | 458篇 |
2001年 | 38篇 |
2000年 | 28篇 |
1999年 | 53篇 |
1998年 | 75篇 |
1997年 | 77篇 |
1996年 | 44篇 |
1995年 | 54篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 25篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 19篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 7篇 |
排序方式: 共有9841条查询结果,搜索用时 31 毫秒
991.
Neves Lia Mara Grosso Tim Carla Roberta Floriano Elaine Medeiros da Silva de Avó Lucimar Retto Fernandes João Batista Parizotto Nivaldo Antonio Cominetti Marcia Regina 《Lasers in medical science》2021,36(4):863-870
Lasers in Medical Science - Ultraviolet radiation (UVR) is the major etiologic agent of cutaneous photoaging, and different strategies are used to prevent and treat this condition. The... 相似文献
992.
Francesca Lombardi Andrea Giacomelli Daniele Armenia Alessia Lai Alex Dusina Antonia Bezenchek Laura Timelli Francesco Saladini Francesca Vichi Paola Corsi Grazia Colao Bianca Bruzzone Roberta Gagliardini Annapaola Callegaro Antonella Castagna Maria Mercedes Santoro 《International journal of antimicrobial agents》2021,57(2):106252
993.
Rodolfo Montironi Liang Cheng Alessia Cimadamore Roberta Mazzucchelli Marina Scarpelli Matteo Santoni Francesco Massari Antonio Lopez-Beltran 《Translational andrology and urology》2021,10(3):1530
The Gleason grading system, proposed by Dr. Donald F. Gleason in 1966, is one of the most important prognostic factors in men with prostate cancer (PCa). At consensus conferences held in 2005 and 2014, organized by the International Society of Urological Pathology (ISUP), the system was modified to reflect the current diagnostic and therapeutic approaches. In particular, in the 2014 Conference, it was recognized that there were weaknesses with the original and the 2005 ISUP modified Gleason systems. Based on the results of a research conducted by Prof. JI Epstein and his group, a new grading system was proposed by the ISUP in order to address some of such deficiencies: i.e., the five distinct Grade Groups (GGs). Since 2014, results of studies have been published by different groups and societies, including the Genitourinary Pathology Society (GUPS), giving additional support to the prognostic role of the architectural Gleason patterns and, in particular, of the GGs. A revised GG system, taking into account the percentage of Gleason pattern (GP) 4, cribriform and intraductal carcinoma, tertiary GP 5, and reactive stroma grade, has shown to have some advantages, however not ready for adoption in the current practice. The aim of this contribution was to review the major updates and recommendations regarding the GPs and GSs, as well as the GGs, trying to give an answer to the following questions: “How has the grade group system been used in the routine?” and “will the Gleason scoring system be replace by the grade groups?” We also discussed the potential implementation in the future of molecular pathology and artificial intelligence in grading to further define risk groups in patients with PCa. 相似文献
994.
Scelzo E Giannicola G Rosa M Ciocca M Ardolino G Cogiamanian F Ferrucci R Fumagalli M Mameli F Barbieri S Priori A 《Neuroscience letters》2011,498(2):167-170
Transcranial direct current stimulation (tDCS), a technique for central neuromodulation, has been recently proposed as possible treatment in several neurological and psychiatric diseases. Although shifts on focal brain excitability have been proposed to explain the clinical effects of tDCS, how tDCS-induced functional changes influence cortical interneurones is still largely unknown. The assessment of short latency afferent inhibition (SLAI) of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS), provides the opportunity to test non-invasively interneuronal cholinergic circuits in the human motor cortex. The aim of the present study was to assess whether anodal tDCS can modulate interneuronal circuits involved in SLAI. Resting motor threshold (RMT), amplitude of unconditioned MEPs and SLAI were assessed in the dominant hemisphere of 12 healthy subjects (aged 21-37) before and after anodal tDCS (primary motor cortex, 13min, 1mA). SLAI was assessed delivering electrical conditioning stimuli to the median nerve at the wrist prior to test TMS given at the interstimulus interval (ISI) of 2ms. Whereas RMT and the amplitude of unconditioned MEPs did not change after anodal tDCS, SLAI significantly increased. In conclusion, anodal tDCS-induced effects depend also on the modulation of cortical interneuronal circuits. The enhancement of cortical cholinergic activity assessed by SLAI could be an important mechanism explaining anodal tDCS action in several pathological conditions. 相似文献
995.
Schillaci O Danieli R Padovano F Testa A Simonetti G 《International journal of molecular medicine》2008,22(1):3-7
Atherosclerosis is a systemic disease of the vessel wall that mainly affects medium- and large-sized arteries, and accounts for 50% of all deaths in western countries. Imaging of atheromatous plaques has traditionally centered on assessing the degree of luminal narrowing. More recently it has become clear that it is of the utmost importance to identify the vulnerable atherosclerotic plaques responsible for the majority of life-threatening syndromes. Molecular imaging using nuclear medicine techniques such as single-photon emission computed tomography (SPECT) and positron emission tomography (PET), has the potential to characterize the activity of atheromas. In the present review we summarize the results of radionuclide imaging in the detection of vulnerable atherosclerotic lesions. 相似文献
996.
Mason Patrick J.; Olson Roberta A.; Myers Jennifer G.; Huszti Heather C.; Kenning Mary 《Journal of pediatric psychology》1989,14(3):341-355
Informational needs of hemophiliacs must first be assessed todevelop effective educational and prevention programs. A surveyof 132 hemophilia patients and family members was conductedto determine the information needs, the preferred source ofinformation and the patients' knowledge of AIDS. Results indicatedthat the major source of information for the patients was themedia; the preferred source was the hemophilia treatment center.Most patients wanted more information about the treatment ofAIDS and how to cope with the stresses of AIDS. Although patientsindicated that they had received sufficient information aboutthe sexual transmission of AIDS, answers to knowledge questionsindicated important misconceptions. Results are discussed withrespect to the development of educational and prevention programsfor hemophiliacs and their families. 相似文献
997.
Tuberculous tenosynovitis is rare and may be overlooked as a cause of chronic tenosynovitis. This report presents a case of a young woman with tuberculosis tenosynovitis of the wrist, and highlights the clinical, imaging, histological, and laboratory features most commonly seen in this disease. 相似文献
998.
Recent studies show that thiazolinediones (TZDs), agonists of the peroxisome proliferator-activated receptor gamma (PPARgamma), induce apoptosis in glioma and glioblastoma cells. Here we compared the effects of troglitazone (Trog), a TZD with low affinity for binding to PPARgamma but with potent metabolic effects, on survival and metabolism in GL261 glioma cells versus primary astrocytes. Trog dose-dependently induced cell death in GL261 cells (with over 90% death at 30 microM) but did not cause any toxicity in astrocytes at the same doses. Measurements of glucose and lactate levels after incubation with Trog (30 microM) indicated an overall increase of glucose consumption and lactate production in both cell types. In astrocytes the ratio of lactate produced to glucose utilized was not significantly altered by Trog, while in glioma cells this ratio was decreased by about 40%. Trog dose-dependently reduced mitochondrial membrane potential (DeltaPsi(m)) in both cell types; and the loss of DeltaPsi(m) was greater in the tumor cells (90% loss at 20 microM) than in astrocytes (70% loss at 20 microM). These results suggest that differences in metabolic responses could contribute to the selective resistance of astrocytes to cytotoxic effects of Trog. TZDs such as Trog should therefore be considered for testing in treatment of gliomas. 相似文献
999.
Edward Otto Celeste Zalewski Michele Kaloss Richard A. Del Giudice Roberta Gardella Gerard J. McGarrity 《Methods in Cell Science》1996,18(4):261-268
A rapid, sensitive assay was developed that can detect the six species of Mycoplasmas that account for the vast majority of cell culture infections. This assay, a modification of the method published by Wong-Lee & Lovett [1], allows direct evaluation of culture medium by a single-step PCR method that utilizes primers complementary to conserved 16S rRNA sequences. Extensive testing of medium from uninfected cultures spiked with purified Mycoplasma DNAs showed that the method described in this report can detect the equivalent of one Mycoplasma in 15 l culture medium; thus, evaluation of a single culture sample allows detection of Mycoplasmas in cultures infected with the equivalent of 10 or more Mycoplasmas per 15 l (or 6.7×102 Mycoplasma equivalents/ml) with greater than 99.99% confidence. Comparison of results obtained with this PCR-based assay and a standard biological colony-forming assay revealed that the PCR assay is capable of detecting 0.0015-0.015 colony forming units, suggesting that the PCR assay may also be detecting nonviable Mycoplasmas. The high level of amplification achieved with this method allows direct detection of amplification products by ethidium bromide staining of agarose gels, and thus allows rapid screening of cell cultures.Abbreviations CFU
colony forming unit
- PCR
polymerase chain reaction 相似文献
1000.
O'Connor RM Wanyiri JW Wojczyk BS Kim K Ward H 《Molecular and biochemical parasitology》2007,152(2):149-158
Cryptosporidium is a cause of diarrheal disease worldwide. Parasite glycoproteins involved in invasion of Cryptosporidium into host cells have been investigated as possible targets for effective interventions against this parasite. One of these, Cpgp40/15, is expressed as a precursor protein that is cleaved by a parasite-derived furin-like protease activity into gp15, a glycophosphatidyl inositol anchored surface protein, and gp40, that associates with gp15 and binds to host cells. Investigation of the functions of these glycoproteins requires an expression system that can produce similar glycosylation patterns to the native antigens. Previous work demonstrated that Cpgp40/15 transiently expressed in Toxoplasma gondii was appropriately localized and glycosylated. In this study, T. gondii stable transfectants expressing gp40/15, gp15, gp40 and hemagglutinin (HA) tagged gp40 were generated. T. gondii recombinant gp40HA and gp40/15 (recTggp40HA and recTggp40/15) were isolated from infected cells by HA affinity chromatography and Helix pomatia lectin affinity chromatography, respectively. Mass spectrometry confirmed that recTggp40-HA and native Cpgp40 were similarly glycosylated. Like native Cpgp40/15, recTggp40/15 could be cleaved into the gp40 and gp15 products by human furin or by a furin-like protease activity in T. gondii tachyzoite lysates. However, processing was inefficient in intact tachyzoites. Unlike the N-terminus of native Cpgp40/15, which appears to be processed following signal peptide cleavage, the N-terminus of recTggp40/15 began at the predicted signal sequence cleavage site, 11 amino acids upstream of the N-terminus of native Cpgp40. The ability to express and isolate appropriately glycosylated Cryptosporidium glycoproteins will enable further investigations into host-parasite interactions of this important pathogen. 相似文献