全文获取类型
收费全文 | 1311篇 |
免费 | 107篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 54篇 |
妇产科学 | 89篇 |
基础医学 | 153篇 |
口腔科学 | 171篇 |
临床医学 | 72篇 |
内科学 | 251篇 |
皮肤病学 | 7篇 |
神经病学 | 79篇 |
特种医学 | 60篇 |
外科学 | 182篇 |
综合类 | 24篇 |
预防医学 | 131篇 |
眼科学 | 24篇 |
药学 | 56篇 |
中国医学 | 1篇 |
肿瘤学 | 46篇 |
出版年
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 18篇 |
2018年 | 26篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 35篇 |
2013年 | 60篇 |
2012年 | 50篇 |
2011年 | 67篇 |
2010年 | 39篇 |
2009年 | 28篇 |
2008年 | 44篇 |
2007年 | 52篇 |
2006年 | 47篇 |
2005年 | 63篇 |
2004年 | 55篇 |
2003年 | 45篇 |
2002年 | 39篇 |
2001年 | 33篇 |
2000年 | 33篇 |
1999年 | 33篇 |
1998年 | 26篇 |
1997年 | 22篇 |
1996年 | 29篇 |
1995年 | 26篇 |
1994年 | 20篇 |
1993年 | 25篇 |
1992年 | 20篇 |
1991年 | 28篇 |
1990年 | 29篇 |
1989年 | 45篇 |
1988年 | 27篇 |
1987年 | 45篇 |
1986年 | 21篇 |
1985年 | 25篇 |
1984年 | 24篇 |
1983年 | 23篇 |
1982年 | 18篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1975年 | 15篇 |
1974年 | 8篇 |
1972年 | 5篇 |
1971年 | 10篇 |
1970年 | 7篇 |
排序方式: 共有1427条查询结果,搜索用时 15 毫秒
51.
Magnetic resonance (MR) imaging has been used in the temporomandibular joint (TMJ) primarily to define the disk position. This report examines altered morphology and signal intensity characteristics of the TMJ disk as they relate to the severity of internal derangement. Two hundred sixteen joints in 133 patients with a history of such derangement. were imaged with MR. Disk position, signal intensity, morphology, and the presence of osteoarthritis were determined for each joint. The normal disk was not anteriorly displaced and had a normal "bow-tie" shape. A grade 1 disk was anteriorly displaced and had a normal shape; a grade 2 disk was anteriorly displaced and had an abnormal shape. Forty (19%) joints were considered normal; none of these exhibited osteoarthritis. One hundred thirty-nine (64%) joints were grade 1; osteoarthritis was found in 17%. Thirty-seven (17%) were grade 2; osteoarthritis was found in 95%. All forty normal joints had high or intermediate signal intensity in the disk. Osteoarthritic joints had a higher percentage of disks with diminished intensity (P less than .0001). Severe or untreated osteoarthritis is known to be a complication of TMJ internal derangements; hence this grading system seems to correlate with the severity of internal derangement. 相似文献
52.
S. I. Martin B. Dodson C. Wheeler J. Davis T. Pesavento G. L. Bumgardner 《American journal of transplantation》2011,11(5):1058-1063
Patients who undergo Epstein–Barr virus (EBV) seromismatch (D+/R − ) transplants have a higher risk for the development of post‐transplant lymphoproliferative disorder (PTLD). Adult renal transplant recipients at a single institution were prospectively monitored for EBV during the first year post‐transplant. Over a 2‐year period, 34 patients (7.78%) were identified as being EBV D+/R − recipients. Patients who developed symptoms or had persistent viremia were pre‐emptively administered rituximab. Six recipients were discharged without monitoring on the protocol. Of those six, three (50%) developed PTLD and all three lost their grafts. Twenty (60.6%) of the 34 recipients developed viremia during the first year post‐transplant. Of the recipients who became viremic, six (30%) received rituximab. None of the six who received rituximab‐developed PTLD. We found that recipients who were not monitored on the protocol were more likely to have PTLD and graft loss compared to those who were (p = 0.008). Post‐transplant monitoring of adults who undergo EBV D+/R − kidney transplants for viremia and symptoms associated with EBV infection may prompt intervention which reduces the incidence of PTLD within the first year. Use of rituximab in preventing PTLD among patients with primary EBV infection requires further prospective study to determine its overall safety and efficacy. 相似文献
53.
Rebecca M. Dodson Amin Firoozmand Omar Hyder Vania Tacher David P. Cosgrove Nikhil Bhagat Joseph M. Herman Christopher L. Wolfgang Jean-Francois H. Geschwind Ihab R. Kamel Timothy M. Pawlik 《Journal of gastrointestinal surgery》2013,17(12):2123-2132
Background
Assessment of patient performance status is often subjective. Sarcopenia—measurement of muscle wasting—may be a more objective means to assess performance status and therefore mortality risk following intra-arterial therapy (IAT).Methods
Total psoas area (TPA) was measured on cross-sectional imaging in 216 patients undergoing IAT of hepatic malignancies between 2002 and 2012. Sarcopenia was defined as TPA in the lowest sex-specific quartile. Impact of sarcopenia was assessed relative to other clinicopathological factors.Results
Indications for IAT included hepatocellular carcinoma (51 %), intrahepatic cholangiocarcinoma (13 %), colorectal liver metastasis (7 %), or other metastatic disease (30 %). Median TPA among men (568 mm2/m2) was greater than women (413 mm2/m2). IAT involved conventional chemoembolization (54 %), drug-eluting beads (40 %), or yttrium-90 (6 %). Median tumor size was 5.8 cm; most patients had multiple lesions (74 %). Ninety-day mortality was 9.3 %; 3-year survival was 39 %. Factors associated with risk of death were tumor size (HR?=?1.84) and Child's score (HR?=?2.15) (all P?<?0.05). On multivariate analysis, sarcopenia remained independently associated with increased risk of death (lowest vs. highest TPA quartile, HR?=?1.84; P?=?0.04). Sarcopenic patients had a 3-year survival of 28 vs. 44 % for non-sarcopenic patients.Conclusions
Sarcopenia was an independent predictor of mortality following IAT with sarcopenic patients having a twofold increased risk of death. Sarcopenia is an objective measure of frailty that can help clinical decision-making regarding IAT for hepatic malignancies. 相似文献54.
Han N. Tran Alexandra J. Lipinski Samuel C. Peter Thomas S. Dodson Rimsha Majeed Ulysses C. Savage J. Gayle Beck 《Journal of traumatic stress》2019,32(2):249-259
Negative beliefs about the self, self‐blame, guilt, and shame have been consistently linked to emotional problems, such as posttraumatic stress disorder and depression, following trauma exposure. To expand understanding of the potential role of negative self‐conscious cognitions and emotions in other forms of posttrauma maladjustments, such as maladaptive behaviors, the current study examined the associations between these cognitions and emotions with dissociation, alcohol use, and avoidant problem‐solving. As a secondary goal, the influence of time since trauma exposure was considered given recent data suggesting that some posttraumatic responses require lengthier time following trauma to become salient. Multiple‐group analysis was conducted in two groups of female survivors of intimate partner violence (IPV): women whose IPV experiences occurred within 3 months prior to assessment (early posttrauma phase [EPP]; n = 67) and those whose experiences occurred 12 months or more prior to assessment (chronic posttrauma phase [CPP]; n = 145). The results suggested model invariance. Posttraumatic negative self‐conscious cognitions and emotions were significantly correlated with dissociation (EPP group: β = .61, p < .001 and CPP group: β = .48, p < .001), alcohol use (EPP group: β = .31, p = .014 and CPP group: β = .30, p < .001), and avoidant problem‐solving (EPP group: β = .58, p < .001 and CPP group: β = .56, p < .001). The findings highlight the importance of negative self‐conscious cognitions and emotions in posttrauma maladjustment and support intervening in these domains shortly after trauma exposure. 相似文献
55.
56.
Identification of motor pathways during tumor surgery facilitated by multichannel electromyographic recording 总被引:3,自引:0,他引:3
OBJECT: The goal of this study was to determine the usefulness of electromyographic (EMG) recording in locating motor pathways near the central sulcus or internal capsule during surgery. METHODS: Multichannel EMG recordings were compared with visual observation of contralateral body movement that was elicited by direct cortical or subcortical stimulation used to identify motor pathways before and during tumor resection. The EMG recordings were more sensitive than visual observation alone in identifying motor responses: in 30% of cases, responses were identified by EMG recording alone at some point during the operation and, in 9% of cases, EMG responses were the only responses observed. Additionally, EMG recordings often detected seizure activity resulting from electrical stimulation of the cortex that could not be appreciated on visual inspection. No new motor deficits were seen postoperatively in 88% of the patients in this series. CONCLUSIONS: Using EMG recording in addition to motor pathway mapping results in greater sensitivity, allowing the use of lower stimulation levels and facilitating detection of stimulation-induced seizure activity. 相似文献
57.
58.
Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability. 相似文献
59.
Intratympanic perfusion for the treatment of tinnitus 总被引:3,自引:0,他引:3
Intratympanic treatment of tinnitus with corticosteroids or gentamicin should be considered as an option of treatment in selected tinnitus patients, alone or in combination with standard modalities of management such as tinnitus retraining therapy, masking, and hearing aid amplification. Review of the literature and the authors' experience suggest the following points regarding intratympanic treatment for tinnitus: 1. Lidocaine, although effective in decreasing tinnitus, has been largely abandoned because of its severe side-effect profile and need for inpatient administration. 2. Corticosteroids have been associated with few if any side effects. 3. The good results reported in the literature with intratympanic steroids for treating tinnitus of various causes should be viewed with caution,because most are retrospective and uncontrolled studies. 4. Some Meniere's disease patients with tinnitus may experience tinnitus improvement following intratympanic steroids. This treatment may be considered in such patients, especially for those with good hearing. 5. Gentamicin is effective in eliminating or reducing tinnitus in a significant number of patients with Meniere's disease and may be considered especially for those with nonserviceable hearing. 6. Further prospective, randomized, and controlled studies to evaluate the effect of intratympanic perfusion for the treatment of tinnitus are warranted. 相似文献
60.
M. Adelaide Asnaghi Philipp Jungebluth Manuela T. Raimondi Sally C. Dickinson Louisa E.N. Rees Tetsuhiko Go Tristan A. Cogan Amanda Dodson Pier Paolo Parnigotto Anthony P. Hollander Martin A. Birchall Maria Teresa Conconi Paolo Macchiarini Sara Mantero 《Biomaterials》2009,30(29):5260-5269
Cell and tissue engineering are now being translated into clinical organ replacement, offering alternatives to fight morbidity, organ shortages and ethico-social problems associated with allotransplantation. Central to the recent first successful use of stem cells to create an organ replacement in man was our development of a bioreactor environment. Critical design features were the abilities to drive the growth of two different cell types, to support 3D maturation, to maintain biomechanical and biological properties and to provide appropriate hydrodynamic stimuli and adequate mass transport. An analytical model was developed and applied to predict oxygen profiles in the bioreactor-cultured organ construct and in the culture media, comparing representative culture configurations and operating conditions. Autologous respiratory epithelial cells and mesenchymal stem cells (BMSCs, then differentiated into chondrocytes) were isolated, characterized and expanded. Both cell types were seeded and cultured onto a decellularized human donor tracheal matrix within the bioreactor. One year post-operatively, graft and patient are healthy, and biopsies confirm angiogenesis, viable epithelial cells and chondrocytes. Our rotating double-chamber bioreactor permits the efficient repopulation of a decellularized human matrix, a concept that can be applied clinically, as demonstrated by the successful tracheal transplantation. 相似文献