全文获取类型
收费全文 | 2473377篇 |
免费 | 176449篇 |
国内免费 | 7795篇 |
专业分类
耳鼻咽喉 | 34583篇 |
儿科学 | 77549篇 |
妇产科学 | 69284篇 |
基础医学 | 354362篇 |
口腔科学 | 70738篇 |
临床医学 | 226042篇 |
内科学 | 475915篇 |
皮肤病学 | 52763篇 |
神经病学 | 201124篇 |
特种医学 | 93609篇 |
外国民族医学 | 795篇 |
外科学 | 362245篇 |
综合类 | 58216篇 |
现状与发展 | 11篇 |
一般理论 | 883篇 |
预防医学 | 192354篇 |
眼科学 | 57177篇 |
药学 | 185596篇 |
28篇 | |
中国医学 | 6580篇 |
肿瘤学 | 137767篇 |
出版年
2018年 | 26282篇 |
2017年 | 20486篇 |
2016年 | 22285篇 |
2015年 | 25553篇 |
2014年 | 35349篇 |
2013年 | 53744篇 |
2012年 | 72466篇 |
2011年 | 76708篇 |
2010年 | 45103篇 |
2009年 | 42364篇 |
2008年 | 71399篇 |
2007年 | 76521篇 |
2006年 | 76940篇 |
2005年 | 74591篇 |
2004年 | 71381篇 |
2003年 | 68487篇 |
2002年 | 66797篇 |
2001年 | 111879篇 |
2000年 | 115419篇 |
1999年 | 97633篇 |
1998年 | 27188篇 |
1997年 | 24711篇 |
1996年 | 23981篇 |
1995年 | 22696篇 |
1994年 | 21219篇 |
1993年 | 19743篇 |
1992年 | 76591篇 |
1991年 | 74651篇 |
1990年 | 72992篇 |
1989年 | 70225篇 |
1988年 | 65228篇 |
1987年 | 63976篇 |
1986年 | 61282篇 |
1985年 | 58250篇 |
1984年 | 43624篇 |
1983年 | 37277篇 |
1982年 | 22383篇 |
1981年 | 20115篇 |
1979年 | 41035篇 |
1978年 | 29332篇 |
1977年 | 24758篇 |
1976年 | 23340篇 |
1975年 | 25301篇 |
1974年 | 30409篇 |
1973年 | 29649篇 |
1972年 | 28014篇 |
1971年 | 26091篇 |
1970年 | 24539篇 |
1969年 | 23030篇 |
1968年 | 21800篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Background
Cerebral arterial gas embolism is a potentially life-threatening event. Intraarterial air can occlude blood flow directly or cause thrombosis. Sclerotherapy is an extremely rare cause of cerebral arterial gas embolism. 相似文献994.
Roberto H. Caraballo Laura Gañez Cecilia De los Santos Alberto Espeche Ricardo Cersósimo Natalio Fejerman 《Seizure》2009,18(10):686-689
PurposeTo analyze the electroclinical features, aetiology and outcome in patients with normal neurological examination and psychomotor development who presented seizures during a mild gastroenteritis (MG).Patients and methodsEvaluation of the clinical charts of 22 patients who were assessed in the Neurology Department, Hospital Nacional de Pediatría Prof. Dr. JP Garrahan between 1999 and 2007.ResultsTwelve patients were boys and 10 were girls, the age of onset ranged from 5 to 26 months, and the median age was 10 months. Rotavirus antigen test in stool was positive in 9 of 18 studied patients. The seizures were brief, focal with secondary generalization in 15 patients (68.5%), apparently generalized in 5 (22.5%) and focal in two (9%). Seven of the patients (35%) had more than one seizure in 24 h. The interictal EEG was normal in all patients. Neuroradiological studies were performed in 19 patients with a normal result. No patient was put on long-term treatment with antiepileptic drugs. Four patients had subsequent mild gastroenteritis and two of them presented convulsions during the disease. After between 12 and 67 months of follow-up, all patients had normal psychomotor development and neurological examination.ConclusionsIn this study we confirmed the association of benign infantile seizures (BIS) and MG with or without rotavirus. The identification of this entity allows avoiding unnecessary complementary studies and treatment with antiepileptic drugs. 相似文献
995.
Rodica Pop-Busui Jiang Lu Neuza Lopes Teresa L. Z. Jones and the BARI D Investigators 《Journal of the peripheral nervous system : JPNS》2009,14(1):1-13
Abstract We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN. 相似文献
996.
997.
Stephen H. Olsen Linglei Ma Bertram Schnitzer Douglas R. Fullen 《Journal of cutaneous pathology》2009,36(3):302-307
Background: Clusterin is a ubiquitous 80 kDa heterodimeric glycoprotein previously shown to be expressed on tumor cells of systemic and, to a lesser extent, primary cutaneous anaplastic large cell lymphoma (PC-ALCL). Lymphomatoid papulosis (LyP), an important differential diagnosis of ALCL, has been studied for clusterin expression in only a small number of cases. The aim of this study was to compare clusterin immunostaining patterns in LyP and other cutaneous histologic simulants with those of PC-ALCL.
Methods: Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
Results: Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
Conclusion: Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants. 相似文献
Methods: Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
Results: Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
Conclusion: Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants. 相似文献
998.
E. González-Guerra M. R. Haro M. C. Fariña L. Martín L. Manzarbeitia L. Requena 《Clinical and experimental dermatology》2009,34(7):800-803
Glomeruloid haemangioma is considered a specific marker of POEMS ( p olyneuropathy, o rganomegaly, e ndocrinopathy, M -protein and s kin changes) syndrome and it is usually but not always associated with multicentric Castleman's disease. We report a 78-year-old man who presented with a single, red-violet soft nodule with superficial telangiectases on the scalp. Histopathologically, the lesion consisted of lobules of coiled aggregated capillaries that involved the lumina of dilated vascular structures, mimicking renal glomeruli. A collagenous stroma separated the capillary lobules, and eosinophilic, periodic-acid–Schiff positive globules of varying sizes and shapes were seen within the cytoplasm of endothelial cells. Immunohistochemical studies with antibodies against IgA and IgG, and against the kappa and lambda light chains of immunoglobulins showed immunoreactivity within the eosinophilic globules. Results of complete blood count, liver, renal and thyroid function tests, fasting blood sugar measurement, serum levels of oestradiol, testosterone, prolactin and cortisol, serum protein electrophoresis, immunoelectrophoresis and immunofixation yielded normal or negative results. No Bence–Jones proteinuria was found in a sample from a 24-h urine collection. To our knowledge, only two cases of glomeruloid haemangioma have been previously reported in patients without POEMS syndrome. We describe the third case of glomeruloid haemangioma in a patient without features of POEMS syndrome. 相似文献
999.
1000.
L.J. Mackintosh† M.N.C. de Koning‡ W.G.V. Quint‡ J. ter Schegget‡ I.M. Morgan R.M. Herd† M.S. Campo 《The British journal of dermatology》2009,161(1):56-62
Background Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献