全文获取类型
收费全文 | 853篇 |
免费 | 64篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 37篇 |
妇产科学 | 18篇 |
基础医学 | 108篇 |
口腔科学 | 7篇 |
临床医学 | 102篇 |
内科学 | 246篇 |
皮肤病学 | 9篇 |
神经病学 | 65篇 |
特种医学 | 39篇 |
外科学 | 88篇 |
综合类 | 3篇 |
预防医学 | 48篇 |
眼科学 | 6篇 |
药学 | 85篇 |
中国医学 | 2篇 |
肿瘤学 | 66篇 |
出版年
2023年 | 8篇 |
2022年 | 24篇 |
2021年 | 39篇 |
2020年 | 14篇 |
2019年 | 30篇 |
2018年 | 24篇 |
2017年 | 22篇 |
2016年 | 26篇 |
2015年 | 26篇 |
2014年 | 27篇 |
2013年 | 33篇 |
2012年 | 61篇 |
2011年 | 65篇 |
2010年 | 31篇 |
2009年 | 28篇 |
2008年 | 62篇 |
2007年 | 54篇 |
2006年 | 47篇 |
2005年 | 58篇 |
2004年 | 36篇 |
2003年 | 39篇 |
2002年 | 29篇 |
2001年 | 21篇 |
2000年 | 22篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 6篇 |
1967年 | 4篇 |
1966年 | 1篇 |
排序方式: 共有933条查询结果,搜索用时 406 毫秒
51.
Transendothelial function of human metastatic melanoma cells: role of the microenvironment in cell-fate determination 总被引:16,自引:0,他引:16
Hendrix MJ Seftor RE Seftor EA Gruman LM Lee LM Nickoloff BJ Miele L Sheriff DD Schatteman GC 《Cancer research》2002,62(3):665-668
On the basis of the ability of aggressive melanoma cells to participate in vasculogenic mimicry, particularly their expression of endothelial-associated genes, we examined the plasticity of human metastatic cutaneous melanoma cells with respect to vascular function. Fluorescently labeled metastatic melanoma cells were challenged to an ischemic microenvironment surgically induced in the hind limbs of nude mice. The data reveal the capability of these melanoma cells to express cell-fate determination molecules, normally expressed during embryonic vasculogenesis, and to participate in the neovascularization of circulation-deficient muscle. These results demonstrate the powerful influence of the microenvironment on the transendothelial differentiation of aggressive melanoma cells, and may provide new perspectives on tumor cell plasticity that could be exploited for novel therapeutic strategies. 相似文献
52.
53.
Luigi A M Castagnetta Orazia M Granata Adele Traina Barbara Ravazzolo Maria Amoroso Monica Miele Vincenzo Bellavia Biagio Agostara Giuseppe Carruba 《Clinical cancer research》2002,8(10):3146-3155
PURPOSE: The main goal of our study was to assess estrogen contents of breast tumor tissues, having different estrogen receptor status, in relation to long-term follow-up of patients. Experimental Design: Twenty-one breast cancer cases, all collected from January 1986 to January 1988 at the M. Ascoli Cancer Hospital Centre in Palermo, were included in the study and compared with 6 healthy women as a control group. Average follow-up time of patients was 144 +/- 10 months. The estrogen receptor status of tissues was determined by both ligand binding and immunohistochemical assays. A high performance liquid chromatography-based approach, jointly with gas chromatography/mass spectrometry, was used to identify and measure main estrogens, various hydroxyestrogens, and their methoxy derivatives in both normal and tumor tissues. RESULTS: Although variable concentrations of hydroxylated estrogens were detected, they consistently accounted for >80% of all of the estrogens. Significantly greater amounts of both 2- and 4-hydroxyestradiol, along with a marked increase of 16 alpha-hydroxyestrone (OHE(1)), were observed in cancer with respect to normal breast tissues. A significant positive association was observed with elevated 16 alpha OHE(1) (P = 0.015) in patients alive, leading to significantly lower (P = 0.043) 2OHE(1):16 alpha OHE(1) ratio values. Conversely, ratio values of 4:2 hydroxy+methoxy estrogens was significantly lower (P = 0.006) in deceased patients. Using cutoff values of 1.2 for 4:2 hydroxy+methoxy ratio and 150 fmol/mg tissue for 16 alpha OHE(1) we achieved a clear-cut separation of patients, with over-cutoff patients having 147 months and under cutoff patients showing only 47 months median survival time (P = 0.00008). CONCLUSIONS: Our data imply that individual hydroxyestrogens may have a distinct role in the onset and the clinical progression of breast cancer, with greater 16 alpha OHE(1) levels being in turn associated to cancer with respect to normal tissues and to a prolonged survival of breast cancer patients. 相似文献
54.
Pânzaru C Georgescu D Maxim I Miron I Moraru E Brumariu O 《Revista medico-chirurgical?? a Societ????ii de Medici ??i Naturali??ti din Ia??i》2005,109(2):242-244
These are unusual diseases in pediatric pathology. We present the morphologic aspects of peripheral blood smear and bone marrow smear of nine storage disease cases. 相似文献
55.
Thinning of the cerebral cortex in aging 总被引:10,自引:6,他引:4
Salat DH Buckner RL Snyder AZ Greve DN Desikan RS Busa E Morris JC Dale AM Fischl B 《Cerebral cortex (New York, N.Y. : 1991)》2004,14(7):721-730
The thickness of the cerebral cortex was measured in 106 non-demented participants ranging in age from 18 to 93 years. For each participant, multiple acquisitions of structural T1-weighted magnetic resonance imaging (MRI) scans were averaged to yield high-resolution, high-contrast data sets. Cortical thickness was estimated as the distance between the gray/white boundary and the outer cortical surface, resulting in a continuous estimate across the cortical mantle. Global thinning was apparent by middle age. Men and women showed a similar degree of global thinning, and did not differ in mean thickness in the younger or older groups. Age-associated differences were widespread but demonstrated a patchwork of regional atrophy and sparing. Examination of subsets of the data from independent samples produced highly similar age-associated patterns of atrophy, suggesting that the specific anatomic patterns within the maps were reliable. Certain results, including prominent atrophy of prefrontal cortex and relative sparing of temporal and parahippocampal cortex, converged with previous findings. Other results were unexpected, such as the finding of prominent atrophy in frontal cortex near primary motor cortex and calcarine cortex near primary visual cortex. These findings demonstrate that cortical thinning occurs by middle age and spans widespread cortical regions that include primary as well as association cortex. 相似文献
56.
An intracranial aneurysm would be low on the differential diagnosis of a patient presenting with behavioral or emotional changes. Nonetheless, complex partial seizures (CPS) may cause such symptoms and result from an unruptured intracranial aneurysm. Failure to diagnose and treat this condition in a timely manner increases the patient's risk of catastrophic aneurysmal rupture. This report describes a 55-year-old woman who presented following two CPS which began with the perception of a strange smell and culminated in a brief loss of consciousness. She had no history of seizure disorder or recent trauma. Magnetic resonance imaging (MRI) revealed a space-occupying lesion over the right temporal lobe near the amygdala. Magnetic resonance angiography (MRA) confirmed a 1.5-cm right middle cerebral artery aneurysm, with a dome projecting toward the amygdalohippocampal region. Following surgical ablation, the patient's CPS were well controlled. A review of the literature is performed on this unusual etiology and management strategies are discussed. 相似文献
57.
Hien DA Cohen LR Miele GM Litt LC Capstick C 《The American journal of psychiatry》2004,161(8):1426-1432
OBJECTIVE: The authors' goal was to compare the efficacy of a manualized cognitive behavior therapy that addresses both posttraumatic stress disorder (PTSD) and substance abuse (seeking safety) with a manualized cognitive behavior therapy that addresses only substance abuse (relapse prevention) and with standard community care for the treatment of comorbid posttraumatic stress disorder (PTSD) and substance use disorder. METHOD: One hundred seven women from an urban, low-income population who had comorbid PTSD and substance use disorder were randomly assigned to receive the two kinds of cognitive behavior therapy or received standard community treatment. Participants were recruited from both community and clinical populations and evaluated with structured clinical instruments. Forty-one women received seeking safety therapy, 34 received relapse prevention therapy, and 32 received standard community care. RESULTS: At the end of 3 months of treatment, participants in both cognitive behavior therapy conditions had significant reductions in substance use, PTSD, and psychiatric symptoms, but community care participants worsened over time. Both groups receiving cognitive behavior therapy sustained greater improvement in substance use and PTSD symptoms at 6-month and 9-month follow-ups than subjects in the community care group. CONCLUSIONS: Seeking safety and relapse prevention are efficacious short-term treatments for low-income urban women with PTSD, substance use disorder, and other psychiatric symptoms. 相似文献
58.
13C-breath tests in the study of mitochondrial liver function 总被引:1,自引:0,他引:1
Candelli M Cazzato IA Zocco MA Nista EC Fini L Armuzzi A Camise V Santoro M Miele L Grieco A Gasbarrini G Gasbarrini A 《European review for medical and pharmacological sciences》2004,8(1):23-31
Breath tests for "dynamic" liver function evaluation have been proposed several years ago. A variety of carbon-labelled breath tests for the assessment of mitochondrial, microsomal and cytosolic liver function have been described with the aim to increase data on liver disease staging, prognosis, and response to therapy. In the last years a great interest is developed about the use of breath test for liver mitochondrial function evaluation since it results impaired in a wide range of liver diseases either of genetic or acquired origin. In these cases mitochondrial oxidative metabolism of some substrates, as far as recovery of the hepatic energy state after a metabolic insult, results impaired because of the disfunction of the electron transport chain and/or ATP synthesis. Ketoisocaproic acid and methionine are the best studied carbon-labelled substrates for the investigation of mitochondrial functional damages related to structural alterations that occur in many liver diseases. Although these tests are simple, cost-effective and safe, to date there is still not general approval for their usefulness in clinical settings since they should fulfill several requirements to overcome the drawbacks of traditional quantitative tests. On the other hand, this field is relatively young and further studies are needed in order to assess the suitable substrate for the evaluation of the complex mitochondrial metabolism both in healthy subjects and in patients with liver disease. 相似文献
59.
Salvinelli F Trivelli M Greco F Casale M Miele A Lamanna F Pallini R 《Revue de laryngologie - otologie - rhinologie》2002,123(2):71-75
INTRODUCTION: The early recognition of incipient Meniere's disease (MD) in the asymptomatic ear of a patient with known unilateral disease has profound implications for patient management and follow-up, but the criteria for a right and precocious diagnosis is still controversial. MATERIALS AND METHODS: We evaluated forty-nine patients with MD, selected according to Committee on Hearing and Equilibrium guidelines. All patients underwent laminar tonal audiometry, stapedial reflex study, Glycerol dehydration test, Auditory Brainstem Response (ABR) vestibular examination. MRI was performed in 14 patients. RESULTS: A raised hearing threshold in the contralateral ear was found in 27 patients, but only 7 (14.3%) fulfilled the requirements to be considered affected by bilateral MD. The average delay of occurrence in the contralateral ear was 7 years (from 5 to 12 years). The glycerol test was positive only in 4 patients with unilateral MD and moderate hearing loss. It was not positive in any case of bilateral MD. The membranous endolymphatic duct and sac is not well visualised with MRI on the affected side in the majority of patients. CONCLUSION: A MRI study must be included in the diagnostic protocol for MD and with improvements in this imaging modality will possibly allow detection of variations in the size of inner ear structures. Glycerol dehydration test was useful only in selected cases. A full assessment of incipient disease in the asymptomatic ear in unilateral Meniere's disease should be undertaken. A conservative approach in surgical treatment of unilateral MD is recommended because of the possibility of evolution of a bilateral form, which can occur even 10 years after the onset of the disease. 相似文献
60.