全文获取类型
收费全文 | 15077篇 |
免费 | 1847篇 |
国内免费 | 254篇 |
专业分类
耳鼻咽喉 | 956篇 |
儿科学 | 259篇 |
妇产科学 | 68篇 |
基础医学 | 1207篇 |
口腔科学 | 675篇 |
临床医学 | 1648篇 |
内科学 | 536篇 |
皮肤病学 | 68篇 |
神经病学 | 794篇 |
特种医学 | 805篇 |
外国民族医学 | 1篇 |
外科学 | 4722篇 |
综合类 | 1860篇 |
预防医学 | 471篇 |
眼科学 | 347篇 |
药学 | 629篇 |
11篇 | |
中国医学 | 442篇 |
肿瘤学 | 1679篇 |
出版年
2024年 | 22篇 |
2023年 | 262篇 |
2022年 | 348篇 |
2021年 | 576篇 |
2020年 | 767篇 |
2019年 | 682篇 |
2018年 | 579篇 |
2017年 | 610篇 |
2016年 | 685篇 |
2015年 | 653篇 |
2014年 | 1000篇 |
2013年 | 1129篇 |
2012年 | 879篇 |
2011年 | 896篇 |
2010年 | 793篇 |
2009年 | 798篇 |
2008年 | 746篇 |
2007年 | 679篇 |
2006年 | 635篇 |
2005年 | 594篇 |
2004年 | 486篇 |
2003年 | 447篇 |
2002年 | 364篇 |
2001年 | 367篇 |
2000年 | 314篇 |
1999年 | 218篇 |
1998年 | 243篇 |
1997年 | 173篇 |
1996年 | 144篇 |
1995年 | 127篇 |
1994年 | 95篇 |
1993年 | 100篇 |
1992年 | 89篇 |
1991年 | 76篇 |
1990年 | 56篇 |
1989年 | 76篇 |
1988年 | 44篇 |
1987年 | 49篇 |
1986年 | 40篇 |
1985年 | 65篇 |
1984年 | 46篇 |
1983年 | 27篇 |
1982年 | 50篇 |
1981年 | 36篇 |
1980年 | 32篇 |
1979年 | 21篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 8篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
31.
Munetaka Matoba Hiroyuki Tuji Yuzo Shimode Tamaki Kondo Kiyotaka Oota Hisao Tonami 《Journal of radiation research》2015,56(3):553-560
The aim of this study was to evaluate whether the lesion regression rate (ΔLR) based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria could be used for the prediction of treatment outcome in head and neck squamous cell carcinoma (HNSCC) patients treated with chemoradiotherapy (CRT) compared with FDG PET-CT. A total of 33 patients underwent MRI and PET-CT at pretreatment and at 8 weeks after CRT. We assessed the treatment outcome by analyzing the following parameters: the RECIST criteria, ΔLR, the European Organization for Research and Treatment of Cancer (EORTC) criteria, and pretreatment SUVmax of the primary tumor and node. The correlation between the analysis of the parameters and the results of the long-term follow-up of the patients was determined. The RECIST did not significantly correlate with locoregional control (LRC) or survival. The ΔLR was significantly lower for the lesions with locoregional failure (LRF) than for those with LRC. A threshold ΔLR of 48% revealed a sensitivity of 72.7% and specificity of 77.3% for the prediction of LRF. Progression-free survival (PFS) of patients with ΔLR ≥ 48% was significantly better than that of patients with ΔLR < 48% (P = 0.001), but not overall survival. There was a significant correlation between LRC and the EORTC (P = 0.02). The patients who achieved a complete response by the EORTC criteria showed significantly better PFS and overall survival (P = 0.01 and 0.04, respectively). The ΔLR was inferior to FDG PET-CT with respect to the prediction of patient survival; however, it may be useful for selecting patients in need of more aggressive monitoring after CRT. 相似文献
32.
《The Journal of emergency medicine》2020,58(2):183-190
BackgroundIncidence of delayed intracranial hemorrhage (DICH) in patients on warfarin has been controversial. No previous literature has reported the utility of international normalized ratio (INR) in predicting traumatic DICH.ObjectivesUtilizing INR to risk stratify head trauma patients who may be managed without repeat imaging.MethodsThis was a retrospective study at a Level II trauma center. All patients on warfarin with head injuries from March 2014 to December 31, 2017 were included. Each patient underwent an initial head computed tomography scan (HCT) and subsequent repeat HCT 12 h after. Patients presenting > 12 h after head injury received only one HCT. Two blinded neuroradiologists reviewed each case of DICH. Statistical analysis evaluated Glasgow Coma Scale (GCS), Injury Severity Score (ISS), heart rate, systolic blood pressure (SBP), age, and platelet count.ResultsThere were 395 patients who qualified for the protocol; 238 were female. Average age was 79 years. Seventy-seven percent of patients underwent repeat HCT. Five resulted in DICH (INR 2.6–3.0), three of which might have been present on initial HCT; incidence rate of 0.51–1.27%. One patient required neurosurgical intervention. Among 80 patients with INR < 2, no DICH was identified, resulting in high sensitivity, but with a wide confidence interval; sensitivity of 100% (95% confidence interval [CI] 47.8–100), specificity 21% (95% CI 16.6–28.9). Correlation of factors: ISS (p = 0.039), GCS (p = 0.978), HR (p = 0.601), SBP (p = 0.198), age (p = 0.014), and platelets (p = 0.281).ConclusionNo patient with INR < 2 suffered DICH, suggesting that warfarin users presenting with INR < 2 may be managed without repeat HCT. For INR > 2, patients age and injury severity can be used for shared decision-making to discharge home with standard head injury precautions and no repeat HCT. 相似文献
33.
空心螺钉治疗股骨颈骨折术后并发症的分析 总被引:9,自引:1,他引:8
目的探讨影响空心螺钉治疗股骨颈骨折术后早期并发症及中晚期股骨头缺血性坏死的因素。方法对1994年1月~2004年1月间应用空心螺钉治疗的116例股骨颈骨折患者进行回顾性总结,将患者性别、年龄、骨折类型、骨折复位情况、外伤至手术时间与骨折术后早期并发症及中晚期股骨头缺血性坏死间的关系进行统计学分析。结果116例患者获平均(3.2±2.5)年(1~11年)随访。术后早期并发症包括:骨折内固定失败6例,骨折周围再骨折2例,感染2例,下肢深静脉血栓6例。年龄是引起骨折术后早期并发症的主要因素之一;骨折术后早期并发症还与骨质情况及内固定技术有关。本组16例出现股骨头缺血性坏死,其坏死率为13.8%。造成股骨头缺血性坏死的因素主要是骨折类型,其次为骨折复位情况。结论①年龄大于60岁的患者股骨颈骨折术后早期并发症相对多。②对于骨折移位严重的高龄患者,建议行人工关节置换术。③内固定术应尽可能解剖复位、坚强牢靠,以减少术后股骨头缺血性坏死的发生。 相似文献
34.
目的比较切开复位内固定术与双极桡骨头假体置换术治疗MasonⅢ型桡骨头骨折的疗效。方法对17例MasonⅢ型桡骨头骨折患者采用Tornier骨水泥柄、双极桡骨头假体进行置换,其中新鲜Ma- sonⅢ型骨折15例,陈旧性MasonⅢ型骨折2例。手术均采用肘关节后外侧入路,17例均行环状韧带修复。术后48 h开始关节逐步被动功能操练。另外8例MasonⅢ型桡骨头骨折患者采用肘后外侧入路切开复位空心钉与多枚克氏针内固定作为对照。结果假体置换组14例患者得到6~27个月(平均12.5个月)随访,按照Broberg和Morrey的肘关节功能评分标准进行评分:优9例,良4例,可1例,优良率为92.8%;3例出现异位骨化,下尺桡关节未见异常改变。8例MasonⅢ型桡骨头骨折内固定患者均得到10~21个月(平均14个月)随访,肘关节功能评分:良1例,可4例,差3例,优良率为12.5%。两组间优良率比较差异有极显著性意义(O<0.01)。结论采用双极桡骨头假体置换的方法治疗MasonⅢ型桡骨头骨折比切开复位内固定的方法更有利于恢复肘关节的稳定、伸屈活动及前臂的旋转活动。 相似文献
35.
目的评价CR,CT,ECT和MRI在早期股骨头缺血性坏死(ANFH)中的诊断价值。方法回顾性分析16例23髋经手术、病理证实为早期(符合国际骨循环研究会(ARCO)分期标准Ⅰ期-Ⅱ期)股骨头缺血性坏死患者的CR,CT,ECT和MRI的影像学特征及其检查结果。结果CR诊断早期ANFH11髋,阳性率为47.8%,CT诊断早期ANFH14髋,阳性率为60.9%,ECT诊断诊断早期ANFH21髋,阳性率为91.3%,MRI诊断早期ANFH22髋,阳性率为95.7%。经统计学处理,X2=19.38,P<0.01,CR,CT,ECT和MRI四者敏感性的差异具有显著性意义。结论对早期股骨头缺血性坏死影像学诊断而言,CR诊断敏感性较低,CT可提供较多的诊断信息,ECT和MRI的敏感性高于CT及CR,MRI可准确地诊断早期股骨头缺血性坏死。 相似文献
36.
经桡动脉行冠状动脉造影术的安全性观察 总被引:3,自引:0,他引:3
目的探讨经桡动脉行冠状动脉(冠脉)造影术的特点及安全性。方法200例患者接受经桡动脉径路行冠脉造影术。结果196例成功,4例失败,其中3例桡动脉迂曲畸形导丝不能通过,1例为锁骨下动脉闭塞。所有患者无严重的并发症出现。结论桡动脉径路行冠状动脉造影具有止血容易,患者卧床时间短和并发症少的优点,是一种安全、有效的介入途径。 相似文献
37.
Claudia Gedlicka Gudrun Hager Martina Weissenböck Wilhelm Gedlicka Birgit Knerer Johannes Kornfehl Michael Formanek 《Journal of oral pathology & medicine》2006,35(8):472-478
BACKGROUND: 1Alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2) Vitamin D(3)] induces growth inhibition in squamous cell carcinoma (SCC) cell lines of the head and neck by arresting the cells in the G0/G1 phase of the cell cycle, probably due to an enhanced expression of p21, which could be demonstrated in other cell lines (JPPA, SCC9) before. In SCC25, a SCC cell line isolated from tongue, growth inhibition but no overexpression of p21 was detected. The retinoblastoma gene, as a direct target of G1 cyclin-CDK complexes, showed an obvious shift from the hyperphosphorylated to the hypophosphorylated form under 1,25(OH)(2)Vitamin D(3), which indicates that the growth inhibition takes place in the G0/G1 phase. To explore the possible pathway of growth inhibition in SCC25 we investigated other cell cycle inhibitors (p18, p19, p27). METHODS: Synchronized cells were treated with 1,25(OH)(2)Vitamin D(3) over 96 h. The cell cycle status and expression of cell cycle-regulating proteins was determined by fluorescence-activated cell sorting (FACS) and Western blotting. An overexpression of p18 in 1,25(OH)(2)Vitamin D(3) vs. ethanol-treated cells was determined until 30 h in SCC25. No influence was detectable on the expression of p27 and p19. CONCLUSION: One mechanism by which 1,25(OH)(2)Vitamin D(3) controls cell growth might be the upregulation of p21. As p21 was unsusceptible to 1,25(OH)(2)Vitamin D(3) in SCC25, other inhibiting proteins were necessary to be tested. The proven upregulation of p18 seems to be the responsible step for growth inhibition of 1,25(OH)(2)Vitamin D(3) in SCC25. 相似文献
38.
Sarah A. Taylor Jacqueline Benedetti David Schuller Stephen P. Richman Goronwy O. Broun Alexander Hantel 《Investigational new drugs》1993,11(2-3):227-229
Summary Twenty-two patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with piroxantrone 150 mg/m2 intravenously every 21 days. There were no objective responses. The 95% upper confidence bound for response is 15%. Primary toxicity was hematologic. 相似文献
39.
[目的]探讨一氧化氮在激素性股骨头坏死发病中的作用.[方法]制作激素性股骨头坏死家兔模型后,在不同时期测定血浆及软骨中的一氧化氮含量,观察股骨头的组织学变化.[结果]激素性股骨头坏死家兔血浆和软骨中的一氧化氮含量均明显升高,股骨头髓腔中的脂肪细胞明显增多,骨小梁变细、稀疏及断裂,空骨陷窝明显增多.电子显微镜观察见骨细胞核染色质浓缩,体积缩小,胞浆中内质网及线粒体肿胀变性,粗面内质网上的核糖体脱落.[结论]一氧化氮参与激素性股骨头坏死的发病过程. 相似文献
40.
Noninvasive Intracranial Cerebral Flow Velocity Evaluation in the Emergency Department by Emergency Physicians 总被引:2,自引:0,他引:2
Michael Shafé MD Michael Blaivas MD RDMS Edmond Hooker MD Leigh Straus BS 《Academic emergency medicine》2004,11(7):774-777
Transcranial Doppler (TCD) is an accepted modality for the evaluation of cerebral blood flow velocities. OBJECTIVES: The purpose of this study was to test the feasibility of bedside TCD measurement in the emergency department (ED) with critically ill, intubated patients. METHODS: A prospective convenience sample of patients presenting to a university hospital over a two-month period underwent TCD evaluation of the middle cerebral artery. Intubated patients with head trauma and any patient requiring tracheal intubation were eligible. A 2-MHz Doppler probe was positioned over the temporal bone to acquire blood flow velocities. An emergency medicine resident and research assistant obtained measurements. Continuous TCD tracings were recorded on a video cassette recorder tape for quality assurance review and data collection. Vital signs and therapeutic interventions were also recorded. Flow velocities were measured in cm/s; the peak Resistance Index (RI) was calculated for each patient. RESULTS: A total of 30 patients were enrolled in the study. Adequate tracings were obtained in 25 patients (83%) without a disruption of resuscitation. Tracings could not be obtained in five patients; they were listed as TCD failures. However, in two of these patients, adequate flow velocity tracings were obtained after resuscitation. Four patients were evaluated during tracheal intubation. One patient was monitored successfully during cardiopulmonary resuscitation. The median time required for data acquisition was 1.9 minutes. The mean highest RI for those who expired was 0.84. For those who survived, the mean highest RI was 0.52. The difference of 0.32 was statistically significant (p = 0.04). CONCLUSIONS: Noninvasive blood flow velocity monitoring of the middle cerebral artery using TCD is feasible in the ED when performed at the bedside on intubated patients with traumatic brain injury and others during tracheal intubation and resuscitation. 相似文献