全文获取类型
收费全文 | 750篇 |
免费 | 49篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 58篇 |
妇产科学 | 5篇 |
基础医学 | 101篇 |
口腔科学 | 61篇 |
临床医学 | 100篇 |
内科学 | 139篇 |
皮肤病学 | 35篇 |
神经病学 | 23篇 |
特种医学 | 143篇 |
外科学 | 66篇 |
综合类 | 16篇 |
预防医学 | 16篇 |
眼科学 | 10篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2023年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 7篇 |
2014年 | 15篇 |
2013年 | 19篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 31篇 |
2009年 | 27篇 |
2008年 | 23篇 |
2007年 | 46篇 |
2006年 | 22篇 |
2005年 | 24篇 |
2004年 | 18篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 16篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 43篇 |
1997年 | 34篇 |
1996年 | 43篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 25篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 16篇 |
1989年 | 33篇 |
1988年 | 33篇 |
1987年 | 27篇 |
1986年 | 23篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1967年 | 1篇 |
1959年 | 1篇 |
1940年 | 3篇 |
1926年 | 4篇 |
排序方式: 共有844条查询结果,搜索用时 15 毫秒
21.
Discoid lupus erythematosus is a manifestation of chronic cutaneous lupus erythematosus with a small risk of systemic involvement. In this review article, the role of predisposing factors such as haplotype, hormones, antibodies and sunlight are discussed. The clinical features, including variants and associations, and management options are presented. 相似文献
22.
Nicholas Risko Emilie JB Calvello Sarah Stewart de Ramirez Mayur Narayan Jon Mark Hirshon 《International journal of emergency medicine》2011,4(1):1-2
The clinical findings of Takatsubo Cardiomyopathy and acute myocardial infarction can be very similar. While Takatsubo cardiomyopathy rarely leads to severe complications, acute myocardial infarction can be life threatening. Treatment of both these conditions is different and so it is imperative for clinicians to have a high index of suspicion for either. Several EKG differences between the two entities have been proposed. This article summarizes the EKG changes most likely seen in Takatsubo cardiomyopathy and compares them to those seen in Acute Myocardial infarction. 相似文献
23.
24.
Macon WR; Williams ME; Greer JP; Hammer RD; Glick AD; Collins RD; Cousar JB 《Blood》1996,87(4):1474-1483
Natural killer (NK)-like T cells are major histocompatibility complex- unrestricted cytotoxic T cells that are surface CD3-positive, express NK-cell antigens, and rearrange their T-cell receptor. Most neoplasms arising from this T-cell subpopulation have been a chronic lymphoproliferative disease referred to as T-large granular lymphocyte (LGL) leukemia. Only 10 NK-like T-cell lymphomas have been described in detail previously; this study presents the clinicopathologic features of six others and distinguishes these lymphomas from T-LGL leukemia. All patients presented with B-symptoms and often had marked hepatosplenomegaly without significant peripheral lymphadenopathy. Four of the six patients were immunosuppressed. All had CD3, CD8, CD56- positive tumors, presumably of hepatosplenic (n = 3), intestinal (n = 1), pulmonary (n = 1), or nodal (n = 1) origin. Three patients had lymphomatous bone marrow infiltrates, and four had peripheral blood involvement by neoplastic large lymphocytes, some of which had a blastic appearance or resembled virocytes. Azurophilic granules, ultrastructurally corresponding to cytoplasmic dense core and/or double density granules, were seen in all cases. T-cell clonality was shown in five tumors by Southern blot analysis, and three had abnormal karyotypes. Two untreated patients died 20 days after presentation, and three patients who received combination chemotherapy died within 5 months of presentation. One patient remains in complete remission 22 months after treatment. These findings suggest NK-like T-cell lymphomas are aggressive, are clinicopathologically distinct from T-LGL leukemia, and should be in the differential diagnosis of extranodal T-cell lymphoproliferations, including those in immunosuppressed patients. Furthermore, the LGL morphology, phenotype, and tissue distribution of some NK-like T-cell lymphomas suggest they arise from thymic- independent T cells of the hepatic sinusoids and intestinal mucosa. 相似文献
25.
胎儿和新生儿同种异体免疫性血小板减少症(AIT)是引起胎儿和新生儿严重血小板减少的最常见原因.母亲针对源自父亲的胎儿血小板抗原的IgG抗体,在妊娠早期就可通过胎盘,通常导致胎儿严重血小板减少.由于一些血小板减少症临界值(50、100或150×109/L)的不同,他们的发生率亦各不相同.但在多数未经选择的人群中,AIT影响1/1 000到1/2 000活产数.在新生儿病房,临床确诊的重症AIT很罕见,可能只有1:10 000分娩数. 相似文献
26.
MA Rafiq M Ansar CR Marshall A Noor N Shaheen A Mowjoodi MA Khan G Ali M Amin‐ud‐Din L Feuk JB Vincent SW Scherer 《Clinical genetics》2010,78(5):478-483
Rafiq MA, Ansar M, Marshall CR, Noor A, Shaheen N, Mowjoodi A, Khan MA, Ali G, Amin‐ud‐Din M, Feuk L, Vincent JB, Scherer SW. Mapping of three novel loci for non‐syndromic autosomal recessive mental retardation (NS‐ARMR) in consanguineous families from Pakistan. To date, of 13 loci with linkage to non‐syndromic autosomal recessive mental retardation (NS‐ARMR), only six genes have been established with associated mutations. Here we present our study on NS‐ARMR among the Pakistani population, where people are traditionally bound to marry within the family or the wider clan. In an exceptional, far‐reaching genetic survey we have collected more than 50 consanguineous families exhibiting clinical symptoms/phenotypes of NS‐ARMR. In the first step, nine families (MR2‐9 and MR11) with multiple affected individuals were selected for molecular genetic studies. Two families (MR3, MR4) showed linkage to already know NS‐ARMR loci. Fifteen affected and 10 unaffected individuals from six (MR2, MR6, MR7, MR8, MR9 and MR11) families were genotyped by using Affymetrix 5.0 or 6.0 single‐nucleotide polymorphism (SNP) microarrays. SNP microarray data was visually inspected by dChip and genome‐wide homozygosity analysis was performed by HomozygosityMapper. Additional mapping was performed (to exclude false‐positive regions of homozygosity called by HomozygosityMapper and dChip) on all available affected and unaffected members in seven NS‐ARMR families, using microsatellite markers. In this manner we were able to map three novel loci in seven different families originating from different areas of Pakistan. Two families (MR2, MR5) showed linkage on chromosome 2p25.3‐p25.2. Three families (MR7, MR8, and MR9) that have been collected from the same village and belong to the same clan were mapped on chromosome 9q34.3. MR11 maps to a locus on 9p23‐p13.3. Analysis of MR6 showed two positive loci, on chromosome 1q23.2‐q23.3 and 8q24.21‐q24.23. Genotyping in additional family members has so far narrowed, but not excluded the 1q locus. In summary, through this study we have identified three new loci for NS‐ARMR, namely MRT14, 15 and 16. 相似文献
27.
PTEN is inversely correlated with the cell survival factor Akt/PKB and is inactivated via multiple mechanismsin haematological malignancies 总被引:7,自引:1,他引:7
28.
Tan WH Baris HN Burrows PE Robson CD Alomari AI Mulliken JB Fishman SJ Irons MB 《Journal of medical genetics》2007,44(9):594-602
Background
Mutations in the PTEN gene cause two disorders that predispose to cancer, Bannayan–Riley–Ruvalcaba and Cowden syndromes. Some patients with a PTEN mutation have only macrocephaly and autism, but they may still be at risk for neoplasms. Vascular anomalies occur in patients with a PTEN mutation, but they have not been systematically studied or precisely defined.Method
We analysed the clinical and radiological features of the vascular anomalies in 26 patients with PTEN mutations who were either seen or had their medical records reviewed at Children''s Hospital Boston.Results
All 23 patients who had their head circumference measured were macrocephalic, and all 13 male patients who were fully examined had penile freckling. Vascular anomalies were found in 14/26 (54%) of patients: 8/14 (57%) had multiple lesions and 11/13 (85%) who had cross‐sectional imaging had intramuscular vascular lesions. Radiographic studies showed that 12/14 (86%) were fast‐flow vascular anomalies, and angiography typically showed focal segmental dilatation of draining veins. Excessive ectopic fat in the vascular anomalies was present in 11/12 (92%) of patients on CT or MRI. Intracranial developmental venous anomalies (DVAs) were found in 8/9 (89%) of patients who had brain MRI with contrast.Conclusions
Vascular anomalies in patients with a PTEN mutation are typically multifocal intramuscular combinations of fast‐flow channels and ectopic fat. Cerebral DVAs are very common. PTEN mutational analysis should be considered for all macrocephalic patients with fast‐flow vascular anomalies or multiple intracranial DVAs. 相似文献29.
M McCarthy JB Yuan A Campbell NP Lenzo K Butler‐Henderson 《Journal of Medical Imaging and Radiation Oncology》2008,52(6):564-569
18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) scans in the first 49 patients referred with either possible brain tumour or brain tumour recurrence were reviewed. FDG‐PET imaging was reported with reference to anatomical imaging. Based on the report the FDG study was classified as either positive or negative for the presence of tumour. Thirty‐eight cases were included in the analysis, 21 having pathological data and 17 with diagnostic clinical follow up. Eleven were excluded, as they had inadequate follow‐up data. Of the 21 cases with pathology, 18 were shown to have tumour. In this group there were five false‐negative scans and two false‐positive PET scans. Seventeen cases were assessed by clinical follow up, nine were considered to have been tumour. There were two false negatives with one false positive. The overall sensitivity, specificity and positive and negative predictive values were 74, 73, 87 and 53% respectively. This is similar to figures previously quoted in published work. Despite relatively limited numbers, the utility of FDG PET imaging in our hands is similar to published reports. With a positive predictive value of 87%, a positive FDG study indicates a high likelihood that there is brain tumour present. A negative study does not exclude the presence of tumour. 相似文献
30.