全文获取类型
收费全文 | 679篇 |
免费 | 102篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 79篇 |
妇产科学 | 2篇 |
基础医学 | 38篇 |
口腔科学 | 13篇 |
临床医学 | 95篇 |
内科学 | 124篇 |
皮肤病学 | 17篇 |
神经病学 | 30篇 |
特种医学 | 126篇 |
外科学 | 76篇 |
综合类 | 11篇 |
现状与发展 | 1篇 |
预防医学 | 45篇 |
眼科学 | 3篇 |
药学 | 29篇 |
肿瘤学 | 91篇 |
出版年
2024年 | 4篇 |
2023年 | 27篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 18篇 |
2019年 | 9篇 |
2018年 | 21篇 |
2017年 | 25篇 |
2016年 | 25篇 |
2015年 | 14篇 |
2014年 | 27篇 |
2013年 | 28篇 |
2012年 | 27篇 |
2011年 | 22篇 |
2010年 | 23篇 |
2009年 | 17篇 |
2008年 | 20篇 |
2007年 | 18篇 |
2006年 | 30篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 27篇 |
1998年 | 32篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 20篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 15篇 |
1988年 | 16篇 |
1987年 | 31篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1984年 | 16篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 4篇 |
排序方式: 共有790条查询结果,搜索用时 15 毫秒
1.
2.
Types of child custody awards made in 884 divorce cases in a rural North Carolina County were compared and rates of postdivorce litigation were examined for each type of custody. Findings suggest a low frequency of joint custody awards and do not reveal any advantage of joint versus other forms of custody with regard to relitigation experience. 相似文献
3.
4.
Ross BD; Jacobson S; Villamil F; Korula J; Kreis R; Ernst T; Shonk T; Moats RA 《Radiology》1994,193(2):457
5.
6.
Richard Byers Jamie Roebuck Ebrahim Sakhinia Judith Hoyland 《Diagnostic molecular pathology》2004,13(3):144-150
RNA extraction still relies almost exclusively on the use of fresh or frozen tissue, limiting the number of samples that can be analyzed, and there is a growing need for means of global mRNA analysis of archived formalin-fixed paraffin-embedded tissue (FFPET). Previous reports of RNA extraction and amplification from FFPET are limited and do not enable global cDNA amplification. This study used polyA PCR to generate globally amplified cDNA from RNA extracted from formalin-fixed paraffin-embedded samples. RNA was extracted from nine routinely processed archival FFPET samples (lymph node, nasopharynx, prostate, lung and bone marrow) using an Ambion Paraffin Block RNA Isolation Kit. Global cDNA was generated by polyA RT-PCR and used in GAPDH specific PCR and PCR for CD33, c-myb, and SNF2. PolyA cDNA was reamplified by polyA PCR and the reamplified cDNA also used in GAPDH PCR. RNA was extracted from all nine samples, but was degraded. PolyA RT-PCR generated cDNA from all samples and was positive for GAPDH PCR in seven. PCR for CD33, c-myb, and SNF2 was positive in all samples tested. Following reamplification, the polyA cDNA remained positive for GAPDH by PCR. The results demonstrate the feasibility of globally amplifying RNA isolated from archival FFPET samples using polyA RT-PCR, which generates a renewable cDNA pool that can be probed for any cDNA species and reamplified as necessary. 相似文献
7.
Skeletal complications in pediatric oncology patients. 总被引:5,自引:0,他引:5
D J Roebuck 《Radiographics》1999,19(4):873-885
Pediatric oncology patients are at risk for the development of numerous skeletal complications, and radiologic studies are important in the identification and evaluation of these conditions. Methotrexate osteopathy manifests as osteopenia, dense provisional zones of calcification, pathologic fractures, and sharply outlined epiphyses. Hypertrophic osteoarthropathy may occur with nasopharyngeal carcinoma or tumors of the lungs or pleura and manifests as cortical thickening, lamellar periosteal new bone formation, and soft-tissue swelling. Biomechanical abnormalities are often seen at bone scintigraphy in patients who have undergone surgery for bone tumors. Growth plate injury may manifest as marked deformity, sclerotic metaphyseal bands, metaphyseal fraying, and longitudinal striations. Radiation "osteitis" is seen as an initial decrease in bone density with subsequent development of a mixed radiolucent and sclerotic appearance. Ischemic necrosis of the femoral heads is best demonstrated at magnetic resonance (MR) imaging and has low signal intensity on T1-weighted images and a high-signal-intensity rim on T2-weighted images. Bone infarcts are seen as well-demarcated, often ring-shaped areas of decreased signal intensity on T1-weighted MR images and as areas of increased signal intensity on short-inversion-time inversion recovery images. Radiographic signs of infection include bone destruction, periosteal new bone formation, and sclerotic changes. Short-inversion-time inversion recovery MR imaging is particularly useful in evaluating posttherapy changes in bone marrow. Osteochondroma may demonstrate a cartilaginous cap at MR imaging, whereas the most important finding in radiation-induced sarcoma is a soft-tissue mass. Radiologists who work with children with cancer need to be familiar with these complications and their imaging appearances. 相似文献
8.
BD White A Kong E Khoo AM Southcott 《Journal of Medical Imaging and Radiation Oncology》2005,49(4):319-321
Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease characterized by the presence of osseous and cartilaginous submucosal nodules projecting into the tracheobronchial tree. Most cases are asymptomatic and discovered incidentally at post‐mortem. We identified a case of TO on thoracic spiral CT and confirmed the diagnosis on bronchoscopy. This article reviews the imaging characteristics of TO, and shows the 3‐D virtual bronchoscopic and multiplanar reconstruction appearances of TO. 相似文献
9.
WBG Macdonald AP Patrikeos RI Thompson BD Adler AA Van Der Schaaf 《Journal of Medical Imaging and Radiation Oncology》2005,49(1):32-38
The present study compared the accuracy of ventilation perfusion scintigraphy (VQS) and CT pulmonary angiography (CTPA) for the diagnosis of pulmonary embolism. This was a prospective observational study of 112 patients with suspected pulmonary embolism (PE) who could be studied with both investigations within 24 h. Results were compared to final diagnosis at completion of 6-month follow up, using receiver operating characteristic (ROC) analysis. Pulmonary embolism was diagnosed in 27 referred patients (24%). The sensitivity and specificity of VQS and CTPA were similar to that reported from the literature. A normal VQ scan had the highest negative predictive value (100%), while a high-probability VQ scan had the highest positive predictive value (92%). There was no overall difference (area under the ROC curve (AUC)) between VQS (AUC (95% CI) = 0.82 (0.75,0.89)) and CTPA (AUC = 0.88 (0.81,0.94)) for the diagnosis of PE. Among patients with abnormal chest X-rays, CTPA (AUC 0.90 (0.83,0.97)) appeared somewhat better than VQS (AUC 0.78 (0.68,0.88)) but this difference did not reach statistical significance. In this instance, CTPA is at least as accurate as VQS and may provide an opportunity to make alternative diagnoses. 相似文献
10.