全文获取类型
收费全文 | 2277篇 |
免费 | 83篇 |
国内免费 | 6篇 |
学科分类
医药卫生 | 2366篇 |
出版年
2024年 | 20篇 |
2023年 | 21篇 |
2022年 | 54篇 |
2021年 | 92篇 |
2020年 | 48篇 |
2019年 | 84篇 |
2018年 | 85篇 |
2017年 | 54篇 |
2016年 | 48篇 |
2015年 | 76篇 |
2014年 | 94篇 |
2013年 | 143篇 |
2012年 | 166篇 |
2011年 | 143篇 |
2010年 | 95篇 |
2009年 | 65篇 |
2008年 | 72篇 |
2007年 | 89篇 |
2006年 | 97篇 |
2005年 | 59篇 |
2004年 | 66篇 |
2003年 | 55篇 |
2002年 | 64篇 |
2001年 | 54篇 |
2000年 | 53篇 |
1999年 | 36篇 |
1998年 | 26篇 |
1997年 | 11篇 |
1996年 | 13篇 |
1995年 | 9篇 |
1992年 | 25篇 |
1991年 | 37篇 |
1990年 | 32篇 |
1989年 | 27篇 |
1988年 | 23篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1977年 | 9篇 |
1975年 | 9篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 9篇 |
1971年 | 7篇 |
排序方式: 共有2366条查询结果,搜索用时 15 毫秒
61.
Roychowdhury S Iyer MK Robinson DR Lonigro RJ Wu YM Cao X Kalyana-Sundaram S Sam L Balbin OA Quist MJ Barrette T Everett J Siddiqui J Kunju LP Navone N Araujo JC Troncoso P Logothetis CJ Innis JW Smith DC Lao CD Kim SY Roberts JS Gruber SB Pienta KJ Talpaz M Chinnaiyan AM 《Science translational medicine》2011,3(111):111ra121
62.
Anubha Bharthuar Alok A. Khorana Alan Hutson Jian-Guo Wang Nigel S. Key Nigel Mackman Renuka V. Iyer 《Thrombosis research》2013
Background
Tissue factor (TF), the physiologic initiator of coagulation, is over-expressed in pancreatic cancer, and is associated with a pro-coagulant and pro-angiogenic state. We hypothesized that in patients with pancreaticobiliary cancers (PBC), elevated circulating microparticle-associated TF (MP-TF) activity would be associated with thrombosis and worsened survival.Patients and Methods
Clinical data and plasma were obtained for consecutive patients with PBC seen at Roswell Park Cancer Institute from 2005-08. MP-TF activity levels were measured using a TF-dependent FXa generation assay.Results
The study population comprised 117 patients, including pancreatic (n = 80), biliary (n = 34) or unknown primary histologically consistent with PBC (n = 3). Of these, 52 patients (44.5%) experienced thromboembolism, including pulmonary embolism (n = 15), deep venous thrombosis (n = 21) and other arterial or venous events (n = 32). Mean TF was 2.15 (range 0.17- 31.01) pg/mL. Median survival was 98.5 days for MP-TF activity ≥ 2.5 pg/mL versus 231 days for MP-TF activity < 2.5 pg/mL (p < 0.0001). In multivariate analysis, elevated MP-TF activity was associated with both VTE (OR 1.4, 95% CI 1.1-1.6) and mortality (HR 2.5, 95% CI 1.4-4.5).Conclusions
Elevated circulating MP-TF activity is associated with thrombosis and worsened survival in patients with PBC. MP-TF activity as a prognostic biomarker warrants further prospective evaluation. 相似文献63.
Spinal evoked potentials were recorded from the dorsal columns of in vitro mouse hemicord preparations. The response of these potentials to different periods of hypoxia was studied. A decrease in amplitude of the potential to 50% and 10% of pre-hypoxia reference occurred after 3.19 ± 1.36 and 7.3 ± 2.97 min, respectively. Complete recovery of the potential was seen in specimens exposed to 5 and 10 min of hypoxia. Incomplete recovery occurred with exposure to longer periods of hypoxia. In preparations that remained isoelectric for less than 5 min total recovery was seen. 相似文献
64.
AbstractThe ability of an experimental lazaroid, U74389G, to prevent damage to hippocampal CA 1 cytoarchitecture due to transient global ischemia was studied by light and electron microscopy. Post-ischemic rats were given a single i.p. dose of lazaroid (6 or 18 mg kg-1) at 5 min after revival by cardiopulmonary resuscitation (CPR). Without lazaroid treatment the number of normal-appearing neurons in the CA1 region declined from a normal value of 75.49± 2.21 to 8.40± 10.08 per 100 μ,m2 on day 7 after the ischemic episode, and there was extensive damage visible in the cytoarchitecture of this region. In lazaroid treated rats, the normal cytoarchitecture was retained and the number of normal-appearing cells was maintained at 15.1O± 2.22 per 100 ¼,m2? Ultrastructure studies indicated that pyknotic pyramidal cells laden with Pysosomal aggregates were common in untreated post-ischemic rats but rare in lazaroid-treated rats. These results indicate that U74389G maintained the structural integrity of this region of the brain after transient global ischemia and suggest that this lazaroid may be an effective neuroprotectant. [Neural Res 1997; 19: 431-434] 相似文献
65.
R Zaitoun S S Iyer R F Lewin G Dorros 《Catheterization and cardiovascular diagnosis》1990,21(3):154-158
Angioplasty using the percutaneous popliteal approach was utilized in 50 patients (PTS) to recanalize 59 occluded superficial femoral arteries which had been unsuccessfully canalized by using the antegrade approach because of either a flush origin occlusion or inability to maintain the guide wire in the true lumen. All PTS had claudication; 8 had rest pain; 3 had non-healing ulcers. The laser Probe was used in 17 cases and the Rotablator in 3 cases. Occlusion length varied between 1 and 40 cm: 7 lesions were less than 10 cm (group 1); 9 were between 10 and 20 cm (group 2); and 43 were greater than 20 cm (group 3). An angiographic success was obtained in 48/59 lesions (81%): 14/16 (87%) in groups 1 and 2 and 34/43 (79%) in group 3. Three PTS needed complementary common femoral endarterectomy and one required percutaneous aspiration of a thromboembolus. Complications included: arterial perforation and/or dissection (without clinical sequelae) in 11 and a popliteal hematoma in 1 PT. One patient with a severely ischemic leg underwent successful emergency vascular surgery, while another limb salvage patient required below-knee amputation. There was no worsening of limb ischemia from any popliteal approach attempt. At discharge, 39 patients (78%) whose outcome would have been unsuccessful with the traditional antegrade approach were clinically improved after utilizing the popliteal approach to achieve a successful angioplasty procedure. 相似文献
66.
We sought to determine the extent of the frontal sinus by intraoperative transillumination through the superomedial orbital wall in a subcranial approach to the anterior skull base. After raising a bicoronal flap, the frontal sinus was transilluminated through the superomedial orbital wall with a fiber-optic light source, delineating the extent of the frontal sinus. The frontal sinus boundary was marked with a marker pen. A frontal sinus anterior wall osteotomy was performed with a sagittal saw, staying within the confines of the frontal sinus marking. A bone flap was removed, and the posterior wall was drilled out. The remaining procedure was performed in a standard fashion. At the end of the procedure, the bone flap was fixed with a titanium plate. A total of 58 patients had undergone craniofacial resection from January 2004 to December 2007. In 13 patients, a subcranial approach was employed using the transillumination technique. Transillumination was successful in delineating the frontal sinus periphery in all 13 patients. Intraoperative transillumination of the frontal sinus through the superomedial orbital wall is a simple and effective method to delineate the frontal sinus periphery in a subcranial approach to the anterior skull base. 相似文献
67.
N. Subramaniam D. Balasubramanian S. Murthy P. Rathod S. Vidhyadharan K. Thankappan S. Iyer 《International journal of oral and maxillofacial surgery》2019,48(2):152-156
According to the eighth edition of the AJCC Cancer Staging Manual (AJCC8), a depth of invasion (DOI) >10 mm is classified as pT3, representing a locally advanced tumour requiring postoperative radiotherapy (PORT). When node-negative, however, evidence regarding whether PORT improves loco-regional control or survival is unclear. To clarify this, two cohorts of patients were studied: (1) patients classified as pT3N0 by the seventh edition of the AJCC manual (AJCC7), with DOI >10 mm and a tumour diameter >4 cm (17 patients who received PORT), and (2) patients classified as pT1N0 and pT2N0 by AJCC7, with DOI >10 mm and a tumour diameter <4 cm (55 patients who did not receive PORT). Loco-regional control and survival were analysed. PORT was found not to impact overall survival or disease-free survival. It was also found not to impact local, regional, or distant recurrence. Although the two subsets of patients considered here (DOI >10 mm with tumour diameter below or above 4 cm) were previously distinct, they are both considered pT3 in AJCC8. Data from this study indicate that the routine administration of PORT to patients with a DOI >10 mm may not be warranted in the absence of other risk features such as nodal disease or close margins. 相似文献
68.
The orientation of the acetabular cup and position of lip augmentation (if present) may improve postoperative total hip replacement stability by decreasing dislocation caused by hip prosthesis impingement during rotation. To determine how these cup parameters affect dislocation, the range and amount of rotation for two standard femoral components was determined in a Sawbones hemipelvis model. The parameters that allowed for maximal range of rotation were a cup angle of inclination between 35 degrees and 45 degrees and cup anteversion between 0 degrees and 10 degrees. Cup anteversion angles greater than 20 degrees and cup angles of inclination greater than 45 degrees significantly limited internal and external rotation, particularly for hip flexion greater than 60 degrees. The position of the cup lip augmentation did not affect the amount of rotation except when the hip was flexed and the lip superiorly oriented. Although there are currently devices to facilitate a particular cup position, hip stem type and orientation are other important factors affecting range of rotation that must be considered. 相似文献
69.
PurposeTo survey the current transitional epilepsy services in tertiary paediatric neurology centres in the UK within the principles of transitional care for young people with epilepsy.MethodsAn online web-based questionnaire was sent to the lead epilepsy clinicians in tertiary paediatric neurology centres on behalf of the British Paediatric Epilepsy Group, the specialist epilepsy group of the British Paediatric Neurology Association (BPNA). A transition clinic was defined as a ‘clinic or service that provided joint paediatric and adult supervision of care from paediatric to adult services’.ResultsTwenty-three centres were approached of which18 responded and 15 of which provided auditable data. The clinics were held between three and 12 times per year, mostly in the afternoon and sited equally between the paediatric and adult centre. Approximately three to five new, and three to eight follow up patients were seen in each clinic. Most clinics accepted new referrals with a minimum age of 14 and a maximum of 20 years. Most young people were seen only once in a transition clinic before then being promoted into the adult epilepsy service. Very few clinics accepted direct referrals from the GP. Adult, slightly more than the paediatric team provided out-of-hospital advice after the young person was seen in the transition clinic.ConclusionsYoung people with epilepsy are a challenging, but interesting group and their care at this time may have a potentially irreversible impact on their life. Their progress from paediatric to adult services should be a dynamic, gradual and smoothly transitioned process to optimise their care. Although recommended by the National Institute for Health and Clinical Excellence (NICE) and the National Services Framework (NSF), the findings of this survey would suggest an un-met need of this population. 相似文献