全文获取类型
收费全文 | 961篇 |
免费 | 54篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 16篇 |
妇产科学 | 10篇 |
基础医学 | 113篇 |
口腔科学 | 24篇 |
临床医学 | 54篇 |
内科学 | 246篇 |
皮肤病学 | 2篇 |
神经病学 | 48篇 |
特种医学 | 30篇 |
外科学 | 183篇 |
综合类 | 6篇 |
预防医学 | 82篇 |
眼科学 | 16篇 |
药学 | 62篇 |
中国医学 | 2篇 |
肿瘤学 | 118篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 12篇 |
2018年 | 22篇 |
2017年 | 17篇 |
2016年 | 24篇 |
2015年 | 25篇 |
2014年 | 44篇 |
2013年 | 50篇 |
2012年 | 67篇 |
2011年 | 70篇 |
2010年 | 37篇 |
2009年 | 26篇 |
2008年 | 56篇 |
2007年 | 71篇 |
2006年 | 63篇 |
2005年 | 72篇 |
2004年 | 81篇 |
2003年 | 61篇 |
2002年 | 53篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 15篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1973年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1961年 | 1篇 |
1959年 | 3篇 |
1958年 | 1篇 |
1957年 | 2篇 |
排序方式: 共有1020条查询结果,搜索用时 93 毫秒
51.
Binding of estrogenic compounds to recombinant estrogen receptor-alpha: application to environmental analysis 总被引:2,自引:0,他引:2
Pillon A Boussioux AM Escande A Aït-Aïssa S Gomez E Fenet H Ruff M Moras D Vignon F Duchesne MJ Casellas C Nicolas JC Balaguer P 《Environmental health perspectives》2005,113(3):278-284
Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polycyclic aromatic hydrocarbons, which do not bind ERs, modulate estrogen activity by means of the aryl hydrocarbon receptor (AhR). In order to characterize compounds that mediate estrogenic activity in river water and sediment samples, we developed a tool based on the ER-alphaligand-binding domain, which permitted us to estimate contaminating estrogenic compound affinities. We designed a simple transactivation assay in which compounds of high affinity were captured by limited amounts of recombinant ER-alpha and whose capture led to a selective inhibition of transactivation. This approach allowed us to bring to light that water samples contain estrogenic compounds that display a high affinity for ERs but are present at low concentrations. In sediment samples, on the contrary, we showed that estrogenic compounds possess a low affinity and are present at high concentration. Finally, we used immobilized recombinant ER-alpha to separate ligands for ER and AhR that are present in river sediments. Immobilized ER-alpha, which does not retain dioxin-like compounds, enabled us to isolate and concentrate ER ligands to facilitate their further analysis. 相似文献
52.
53.
54.
Singh K Heller JG Samartzis D Price JS An HS Yoon ST Rhee J Ledlie JT Phillips FM 《Journal of spinal disorders & techniques》2005,18(5):413-419
Osteoporotic burst fractures with neurologic symptoms are typically treated with neural decompression and multilevel instrumented fusion. These large surgical interventions are challenging because of patients' advanced ages, medical co-morbidities, and poor fixation secondary to osteoporosis. The purpose of this retrospective clinical study was to describe a novel technique for the treatment of osteoporotic burst fractures and symptomatic spinal stenosis via a limited thoracolumbar decompression with open cement augmentation [vertebroplasty (VP) or kyphoplasty (KP)]. Indications for decompression and cement augmentation were intractable pain at the level of a known osteoporotic burst fracture with symptoms of spinal stenosis. As such, 25 patients (mean age, 76.1 years) with low-energy, osteoporotic, thoracolumbar burst fractures (7 males, 18 females; 39 fractures) were included. In all cases, laminectomy of the stenotic level(s) was followed by vertebral cement augmentation (9 VP; 16 KP). When a spondylolisthesis at the decompressed level was present, instrumentation was applied across the listhetic level (n = 9). Clinical outcome (1 = poor to 4 = excellent) was assessed on last clinical follow-up (mean, 44.8 wks). In addition, a modified MacNab's grading criteria was used to objectively assess patient outcomes postoperatively. Radiographic analysis of sagittal contour was assessed preoperatively, immediately postoperatively, and at final follow-up. The average time from onset of symptoms to intervention was 19 weeks (range, 0.3-94 wks). A mean of 1.6 fractures/patient was augmented (range, 1-3 fractures) and 2.8 levels were decompressed (range, 1-6 levels). No statistical difference in anatomic distribution or number of fractures between the VP and KP groups or in the instrumented versus noninstrumented patients was noted (P > 0.05). An overall subjective outcome score of 3.4 was noted. Twenty of 25 patients were graded as excellent/good according to the modified MacNab's criteria. The choice of augmentation procedure or use of instrumentation did not predict outcome (P = 0.08). Overall, 1.7 degrees of sagittal correction was obtained at final follow-up. One patient was noted to have progressive kyphosis after KP. The use of a limited-posterior decompression and open cement augmentation via VP or KP is a safe treatment option for patients who have osteoporotic burst fractures and who are incapacitated from fracture pain and concomitant stenosis. After thoracolumbar decompression, open VP/KP provides direct visualization of the posterior vertebral body wall, allowing for safe cement augmentation of burst fractures, stabilizing the spine, and obviating the need for extensive spinal reconstruction. Although clinically successful, this technique warrants careful patient selection. 相似文献
55.
The clinical case reported here concerns a giant lipoma (22 x 12 x 10 cm; 2740 g) located in the distal region of the right thigh, in a subfascial zone. The patient was referred to our department for a relapse of thrombophlebitis of the right lower limb (occurring about two years earlier) and presented a large tumefaction of the mid third of thigh at objective examination, the presumed onset of which dated back about ten years after a traumatic accident. Ultrasonography confirmed the presence of the tumefaction but did not allow us to identify its origin with certainty. Musculoskeletal magnetic resonance imaging, however, revealed a gross expansive lesion closely connected to the distal part of the femur, suggesting its probable benign nature. The mass was totally resected without either muscle section or the sacrifice of periosteum. The histological findings indicated an atypical lipomatous tumour. The therapy of giant lipomas is invariably surgical excision. Nevertheless, the high risk of relapse (which is typical of this kind of neoplastic proliferation) despite radical resection, makes a systematic postoperative follow-up necessary. 相似文献
56.
57.
Pulmonary arterial hypertension: the key role of echocardiography 总被引:11,自引:0,他引:11
Given the nonspecific nature of its early symptoms and signs, pulmonary arterial hypertension (PAH) is often diagnosed in its advanced stages. Although clinical assessment is essential when initially evaluating patients with suspected PAH, echocardiography is a key screening tool in the diagnostic algorithm. It not only provides an estimate of pulmonary pressure at rest and during exercise, but it may also help to exclude any secondary causes of pulmonary hypertension, predict the prognosis, monitor the efficacy of specific therapeutic interventions, and detect the preclinical stage of the disease. 相似文献
58.
59.
Growth and adult height in atypical coeliac patients, with or without growth hormone deficiency 总被引:1,自引:0,他引:1
Salardi S Cacciari E Volta U Santoni R Ragni L Elleri D Cicognani A Vaira D 《Journal of pediatric endocrinology & metabolism : JPEM》2005,18(8):769-775
OBJECTIVE: To evaluate the effect of a gluten-free diet on growth and adult height, when available, in coeliac children without gastrointestinal symptoms. PATIENTS AND METHODS: Sixty-one coeliac children without gastro-intestinal symptoms were included in the study. The age at diagnosis was 9.50 +/- 3.3 years. Thirty-eight had short stature at diagnosis (< 10th percentile) and 23 had normal stature. Thirty-seven reached adult height. RESULTS: After beginning the diet an increase in growth velocity was seen in 30 patients (responders) (20 with initial short stature), while in 31 patients (18 with short stature) there was no catch-up growth (non-responders). Bone age at diagnosis was significantly more delayed in the responders than in the non-responders. Target height was significantly higher in children with normal stature at diagnosis than those with short stature. Growth hormone (GH) deficiency was found and confirmed after 6-12 months of diet in 12 of the 38 patients (32%) with short stature. In the group of the 30 'short' patients who attained final height, target height was attained or improved in 12 patients (40%): in eight of the 16 (50%) responders and in four of the 14 (29%) non-responders; in eight (all responders) out of 22 (36%) without GH deficiency, and in four out of eight (50%) patients with GH deficiency treated with GH (all non-responders). CONCLUSIONS: In children in whom coeliac disease is diagnosed because of short stature, a gluten-free diet will be successful if at diagnosis there is a delay of bone age and in the first year of diet there is an evident catch-up growth. When this does not occur, i.e. in half of the patients (18 out of 38), it may be because of an associated and transient GH deficiency. In these patients a period of GH replacement therapy as well as a gluten-free diet may improve their final height. 相似文献
60.
Ravnic DJ Jiang X Wolloscheck T Pratt JP Huss H Mentzer SJ Konerding MA 《Microvascular research》2005,70(1-2):90-96
Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demonstrated that fluorescent vessel painting modestly overestimated the interbranch angles, interbranch distances, and vessel diameters of the 2D mucosal plexus of the colon. These differences were narrowed with the application of confocal microscopy. The advantages of fluorescence vessel painting included (1) the filling of all tissues including the relatively high resistance microvessels of the mouse skin, (2) the ability to use tissue counterstains such as DAPI, and (3) the prolonged stability of the lipophilic tracer after aldehyde fixation. These studies suggest the utility of fluorescent vessel painting as a complementary technique to corrosion casting in the morphometric study of the microcirculation. 相似文献