全文获取类型
收费全文 | 1470473篇 |
免费 | 127500篇 |
国内免费 | 6384篇 |
专业分类
耳鼻咽喉 | 21308篇 |
儿科学 | 48388篇 |
妇产科学 | 38489篇 |
基础医学 | 200726篇 |
口腔科学 | 37274篇 |
临床医学 | 153947篇 |
内科学 | 300065篇 |
皮肤病学 | 33328篇 |
神经病学 | 125108篇 |
特种医学 | 53908篇 |
外国民族医学 | 366篇 |
外科学 | 220723篇 |
综合类 | 29002篇 |
现状与发展 | 73篇 |
一般理论 | 460篇 |
预防医学 | 120447篇 |
眼科学 | 32050篇 |
药学 | 99713篇 |
6篇 | |
中国医学 | 3176篇 |
肿瘤学 | 85800篇 |
出版年
2021年 | 13528篇 |
2020年 | 12118篇 |
2019年 | 13462篇 |
2018年 | 22794篇 |
2017年 | 18786篇 |
2016年 | 20612篇 |
2015年 | 22524篇 |
2014年 | 34694篇 |
2013年 | 46047篇 |
2012年 | 49119篇 |
2011年 | 51873篇 |
2010年 | 36453篇 |
2009年 | 37828篇 |
2008年 | 47981篇 |
2007年 | 48788篇 |
2006年 | 51117篇 |
2005年 | 47054篇 |
2004年 | 44373篇 |
2003年 | 41325篇 |
2002年 | 40214篇 |
2001年 | 64267篇 |
2000年 | 65221篇 |
1999年 | 55174篇 |
1998年 | 17839篇 |
1997年 | 16332篇 |
1996年 | 16082篇 |
1995年 | 15277篇 |
1994年 | 13346篇 |
1993年 | 12302篇 |
1992年 | 42753篇 |
1991年 | 42011篇 |
1990年 | 40358篇 |
1989年 | 38367篇 |
1988年 | 35473篇 |
1987年 | 34449篇 |
1986年 | 32933篇 |
1985年 | 31258篇 |
1984年 | 23515篇 |
1983年 | 20038篇 |
1982年 | 12195篇 |
1979年 | 21058篇 |
1978年 | 15096篇 |
1977年 | 12398篇 |
1976年 | 12073篇 |
1975年 | 12348篇 |
1974年 | 14997篇 |
1973年 | 14673篇 |
1972年 | 13625篇 |
1971年 | 12605篇 |
1970年 | 11706篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
BACKGROUND Hidradenitis suppurativa (HS) is a difficult disease to treat. Surgery may be curative, but just like cancer surgery, it must be complete to effect a cure. Preoperative imaging of hidradenitis lesions is therefore of interest.
OBJECTIVE The objective was to study the ultrasound characteristics of hidradenitis and compare these to the clinical findings.
MATERIALS AND METHODS Real-time compound imaging ultrasound systems were used (Philips HDI 5000 and iU22) to visualize HS lesions in seven patients and regional controls images from eight healthy volunteers.
RESULTS Hidradenitis-related features were identified: various fluid collections, increased dermal thickness (mean±SD, 3.3±1.0 mm vs. 1.4±0.3 mm for controls) and lower echogenicity of the skin. In comparison with clinical examination, we were able to identify both subclinical lesions and subclinical extension of lesions into clinically normal looking paralesional skin. Hair follicles appeared distended.
CONCLUSION A number of HS features can be identified by ultrasound. These features include both actual lesions and possible predisposing factors such as skin thickness and hair follicle morphology. Ultrasonography can identify the true extent of lesions in HS, which may be of use in the preoperative planning. 相似文献
OBJECTIVE The objective was to study the ultrasound characteristics of hidradenitis and compare these to the clinical findings.
MATERIALS AND METHODS Real-time compound imaging ultrasound systems were used (Philips HDI 5000 and iU22) to visualize HS lesions in seven patients and regional controls images from eight healthy volunteers.
RESULTS Hidradenitis-related features were identified: various fluid collections, increased dermal thickness (mean±SD, 3.3±1.0 mm vs. 1.4±0.3 mm for controls) and lower echogenicity of the skin. In comparison with clinical examination, we were able to identify both subclinical lesions and subclinical extension of lesions into clinically normal looking paralesional skin. Hair follicles appeared distended.
CONCLUSION A number of HS features can be identified by ultrasound. These features include both actual lesions and possible predisposing factors such as skin thickness and hair follicle morphology. Ultrasonography can identify the true extent of lesions in HS, which may be of use in the preoperative planning. 相似文献
992.
993.
994.
Neurologic complications are common after transplantation and affect 30-60% of transplant recipients. The etiology of most of the posttransplant neurologic disorders is related to the opportunistic infections, both systemic and involving central nervous system (CNS), toxicity of immunosuppressive medications, and the metabolic insult created by the underlying primary disease and the transplant procedure. Neuroimaging studies are one of the key tools in the evaluation and enable early diagnosis of neurologic complications in transplant patients, especially posterior reversible leukoencephalopathy syndrome, central pontine myelinolysis, intracerebral hemorrhage, and fungal and bacterial abscesses. Magnetic resonance imaging (MRI) is the preferred technique, but each of the available neuroimaging techniques offers a unique insight into the pathophysiologic mechanisms underlying neurologic complications of transplantation. The role of neuroimaging in this population includes early detection of calcineurin inhibitor neurotoxicity, opportunistic infections, neoplasia, metabolic disorders, or cerebrovascular diseases. In addition, we can monitor longitudinal progression of disease and treatment response. 相似文献
995.
L Crespo J Graus F García-Hoz R Bárcena L Gil Grande V F Moreira J M Milicua J Sánchez J Blázquez 《Revista española de enfermedades digestivas》2007,99(11):667-670
Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques. 相似文献
996.
E. Drakaki E. Borisova M. Makropoulou L. Avramov A. A. Serafetinides I. Angelov 《Skin research and technology》2007,13(4):350-359
BACKGROUND/PURPOSE: Laser-induced autofluorescence spectroscopy provides excellent possibilities for medical diagnostics of different tissue pathologies including cancer. However, to create the whole picture of pathological changes, investigators collect spectral information from patients in vivo or they study different tumor models to obtain objective information for fluorescent properties of every kind of healthy and diseased tissue. Therefore, it is very important to find the most appropriate, and close to the human skin, animal samples from the fluorescence point of view, which will allow the extrapolation of the animal data to human spectroscopic diagnostics. METHODS: In the present work, we examined the autofluorescence properties of different animal skin tissues, which are considered as the most common skin models. A nitrogen laser was used as an excitation source. Samples of healthy mouse, chicken and pig skin in vivo and/or ex vivo were studied and were compared with results obtained from investigations of healthy human skin in vivo. RESULTS AND CONCLUSION: Specific features of the recorded spectra are discussed and the possible origin of the obtained fluorescence signals is proposed. Quantitative evaluation of data extrapolation for each skin type is also depicted. 相似文献
997.
L. C. Teoh 《ANZ journal of surgery》2007,77(Z1):A35-A35
The severely of skin loss and the options of resurfacing is determined by taking into account the following factors. 1) The size & location of the defect, 2) The depth of the defect and the quality of the tissue bed, 3) The extent of exposed vital structures, 4) The associated bone and other tissues injuries, 5) The availability of donor skin flap. The size of the defect is the most important factor in choosing a resurfacing option. The size can be categorized into small, medium and large. A small defect is one that is less than 5 cm2 in size, a medium defect is between 5 to 15 cm2, and a large defect is greater than 15 cm2. Local flaps are usually sufficient to cover small defects <5 cm2. These are advancement flaps or rotation and transposition flaps. Regional flaps are indicated to resurface these medium‐sized defects 5 to 15 cm2. The donor is within the same region of the hand, from one of the digits or from dorsum and palmar surfaces of the hand. It is usually based on vascular or NV pedicles. Large defects >15 cm2 will need larger flaps for coverage. These large flaps are pedicled distant flaps and free flaps. In these severe injuries, there is usually associated bone and soft tissues injuries. These injuries can be reconstructed as a single stage combined reconstruction or multi‐staged reconstructions. The resurfacing should always be given priority. 相似文献
998.
A K Burroughs L Marelli E Cholongitas P Manousou K Rolles V Karam V Delvart R Adam C Sabin 《Liver transplantation》2007,13(6):935-6; author reply 937
999.
1000.