全文获取类型
收费全文 | 40764篇 |
免费 | 2654篇 |
国内免费 | 929篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 641篇 |
妇产科学 | 255篇 |
基础医学 | 1998篇 |
口腔科学 | 167篇 |
临床医学 | 7133篇 |
内科学 | 9606篇 |
皮肤病学 | 91篇 |
神经病学 | 746篇 |
特种医学 | 1680篇 |
外国民族医学 | 4篇 |
外科学 | 5906篇 |
综合类 | 7872篇 |
现状与发展 | 2篇 |
预防医学 | 2056篇 |
眼科学 | 448篇 |
药学 | 3401篇 |
87篇 | |
中国医学 | 1109篇 |
肿瘤学 | 1009篇 |
出版年
2024年 | 65篇 |
2023年 | 589篇 |
2022年 | 944篇 |
2021年 | 1409篇 |
2020年 | 1540篇 |
2019年 | 1345篇 |
2018年 | 1286篇 |
2017年 | 1137篇 |
2016年 | 1213篇 |
2015年 | 1433篇 |
2014年 | 2791篇 |
2013年 | 2901篇 |
2012年 | 2340篇 |
2011年 | 2421篇 |
2010年 | 1932篇 |
2009年 | 1941篇 |
2008年 | 1968篇 |
2007年 | 2164篇 |
2006年 | 1977篇 |
2005年 | 1793篇 |
2004年 | 1466篇 |
2003年 | 1229篇 |
2002年 | 1015篇 |
2001年 | 980篇 |
2000年 | 725篇 |
1999年 | 659篇 |
1998年 | 583篇 |
1997年 | 577篇 |
1996年 | 442篇 |
1995年 | 423篇 |
1994年 | 376篇 |
1993年 | 309篇 |
1992年 | 294篇 |
1991年 | 270篇 |
1990年 | 227篇 |
1989年 | 150篇 |
1988年 | 176篇 |
1987年 | 174篇 |
1986年 | 130篇 |
1985年 | 182篇 |
1984年 | 156篇 |
1983年 | 107篇 |
1982年 | 84篇 |
1981年 | 106篇 |
1980年 | 75篇 |
1979年 | 54篇 |
1978年 | 50篇 |
1977年 | 43篇 |
1976年 | 32篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
食管贲门癌术后早期肠内营养支持的应用研究 总被引:2,自引:0,他引:2
目的研究食管贵门癌切除术中放置鼻肠营养管进行早期肠内营养,在维持机体营养、促进恢复履在防治术后并发症的作用。方法将90例管责门癌病人随机分为A、B两组,A组术后常规静脉输液,B组术中放置鼻肠营养管,术后第1天给予肠内营养。两组病人监测术前、术后第10天的体重、肠功能恢复排气时间、疲劳评分,吻合口瘘反感染并发症的发生率。结果两组病人在体重、肠功能恢复方面存在明显差异(P〈0.05),在术后并发症方面差异明显(P〈0.01)。结论鼻肠营养管进行早期肠内营养具有易于维持机体营养,促进机体康复,尽快恢复正氮平衡,减少术后并发症的优点。 相似文献
102.
目的 床旁临时起搏器作为急性心肌梗死(AMI)的常备急救设备的价值及其在基层医院推广应用的可行性研究。方法 回顾性研究分析2001-2003年间不能床旁植入临时起搏器与2004-2005年能床旁植入临床起搏器抢救AMI的住院病死率、心衰、心源性休克、2mo后再次住院发生率。临时起搏器植入术安全性的指标比较。结果 不能床旁植入临时起搏器组的住院病死率为14.58%,心衰发生率为27.08%,心源性休克发生率为12.5%,2mo后再次住院发生率为16.67%。床旁植入临时起搏器组的住院病死率为3.57%,心衰发生率为7.14%,心源性休克发生率为3.57%,2mo后再次住院发生率为3.57%,两组相比p〈0.01有显著性差异。而起搏器植入的安全性指标:起搏器植入成功率为100%,脱位率为10.7%,并发症发生率为14.3%,住院病死率3.57%。结论 床旁临时起搏器抢救AMI住院病死率低,心衰发生率、心源性休克发生率及2mo后再次住院发生率低,应作为AMI抢救的常备急救设备,另外床旁临时起搏器植入是安全的、有效的,成功率高,操作不难,在基层医院(二甲医院)可推广应用。 相似文献
103.
Tom Rossenbacker MD Sheila J. Carroll MD Huajun Liu MD Cuno Kuipri Thomy J.L. de Ravel FCP Koen Devriendt MD PhD Peter Carmeliet MD PhD Robert S. Kass PhD Hein Heidbüchel MD PhD 《Heart rhythm》2004,1(5):611-615
OBJECTIVES: The purpose of this study was to determine the clinical and biophysical characteristics of a novel SCN5A mutation. BACKGROUND: Brugada syndrome and isolated cardiac conduction defect have been linked to SCN5A mutations. METHODS: Eleven members of a western European family underwent electrophysiologic investigations and mutation analysis of the SCN5A gene. Wild-type and mutant SCN5A channels were expressed in HEK293 cells, and whole cell currents were studied using patch clamp procedures. RESULTS: A novel mutation, R376H, in the first pore segment of SCN5A variably causes Brugada syndrome and/or conduction disease in a single family. Biophysical analysis demonstrated a significant current reduction for the mutant, a pathophysiologic profile consistent with Brugada syndrome and isolated cardiac conduction defect. Among 11 family members, 9 were carriers of the mutation. The proband's initial presentation was a saddleback Brugada ECG, atrial flutter, and diffuse conduction disturbances. He had no inducible ventricular arrhythmias but experienced sudden cardiac death. His brother was affected by atrial flutter and had a clear conduction disorder, but he did not display baseline or evocable ECG signs of Brugada syndrome. He received an implantable cardioverter-defibrillator that delivered one appropriate shock after 1 year of follow-up. The phenotype in the family members was highly variable and ranged from noninducible and inducible asymptomatic carriers of the mutations to isolated conduction disease and to symptomatic Brugada syndrome. CONCLUSIONS: We describe the functional characterization of a novel SCN5A pore mutation, R376H, with variable clinical expression in the same family. Differentiating between electrophysiologic entities (Brugada syndrome-isolated cardiac conduction defect) is more challenging. Recognition of factors modifying the clinical presentation may be important for clinical decision making. 相似文献
104.
105.
Multicoil Dixon chemical species separation with an iterative least-squares estimation method. 总被引:1,自引:0,他引:1
Scott B Reeder Zhifei Wen Huanzhou Yu Angel R Pineda Garry E Gold Michael Markl Norbert J Pelc 《Magnetic resonance in medicine》2004,51(1):35-45
This work describes a new approach to multipoint Dixon fat-water separation that is amenable to pulse sequences that require short echo time (TE) increments, such as steady-state free precession (SSFP) and fast spin-echo (FSE) imaging. Using an iterative linear least-squares method that decomposes water and fat images from source images acquired at short TE increments, images with a high signal-to-noise ratio (SNR) and uniform separation of water and fat are obtained. This algorithm extends to multicoil reconstruction with minimal additional complexity. Examples of single- and multicoil fat-water decompositions are shown from source images acquired at both 1.5T and 3.0T. Examples in the knee, ankle, pelvis, abdomen, and heart are shown, using FSE, SSFP, and spoiled gradient-echo (SPGR) pulse sequences. The algorithm was applied to systems with multiple chemical species, and an example of water-fat-silicone separation is shown. An analysis of the noise performance of this method is described, and methods to improve noise performance through multicoil acquisition and field map smoothing are discussed. 相似文献
106.
闭合复位经皮穿针治疗移位的肱骨外科颈骨折 总被引:13,自引:0,他引:13
目的总结闭合复位经皮穿针治疗移位的肱骨外科颈骨折的方法及结果。方法2001年1月~2002年12月,采用闭合复位、经皮穿针治疗移位的肱骨外科颈骨折46例,仅对其中随访资料完整的34例患者进行分析。结果34例获得22个月(10~34个月)的平均随访。采用Constant-Murley评分方法,平均Constant-Murley绝对值为92分(76~100分),优良占86%(29/34),可占14%(5/34),无差病例。所有骨折在术后6~8周愈合,无固定失效,未出现肱骨头坏死病例。结论闭合复位经皮穿针治疗移位的肱骨外科颈骨折手术时间短、软组织损伤小、固定可靠,术后可早期功能锻炼,取针简便。 相似文献
107.
目的:探讨开放性腹部损伤的治疗方法。方法:回顾性分析1991年-1994年32例开放性腹部损伤患者的临床资料。结果:开腹探查26例,单纯缝合6例,阴性探查3例,二次手术2例,术后切口感染2例,感染性休克死亡1例,治愈31例,病死率为3.12%。结论:开放性腹部外伤,首先要根据临床表现及辅助检查判定内脏是否损伤,手术时机的掌握是治疗的关键。 相似文献
108.
Vanishing fluid collections in interlobar fissures, associated with congestive cardiac failure, are uncommon but well-recognized. Previous studies have highlighted the occurrence of solitary vanishing ‘tumours’, but in the study reported here 7 out of 12 consecutive patients presented with more than one interlobar fluid collection simulating pulmonary tumours. In most cases a lateral radiograph confirmed the correct diagnosis and in all cases follow-up radiographs demonstrated resolution of all pleural fluid collections. In one case ultrasound was helpful. Making the correct diagnosis is very important inorder to prevent inappropriate investigations and treatment such as biopsy or surgery. It is suggested that unusual pleural fluid collections may be more common in communities where pleural disease following stab wounds or tuberculosis are more prevalent. 相似文献
109.
David P. Faxon David Holmes Geoffrey Hartzler Spencer B. King Gerald Dorros 《Catheterization and cardiovascular interventions》1992,25(1):1-3
At present, the majority of cardiac catheterization laboratories acquire and store hemo-dynamic data in analog form. To examine the possibility of performing complex analysis of digital data during the catheterization procedure, we examined whether virtual realtime digital (fast Fourier) analysis improves the accuracy of clinical data. We compared digital filtering of fluid manometry during right heart catheterization with 10-Hz and 250-Hz analog filters. Using the simultaneously acquired micromanometry as the “gold standard,” we found that analog filtering is associated with a greater error and time delay than digital filtering. This study demonstrates that digital hemodynamic data analysis performed during cardiac catheterization can improve the quality of data obtained during right heart catheterization, with the results available within seconds. More extensive use of computers in the cardiac catheterization laboratory may be useful for both clinical and research purposes. © 1992 Wiley-Liss, Inc. 相似文献
110.
Changes in cardiac output and in superior mesenteric arterial flow were followed with Doppler ultrasound techniques in five young, healthy persons for 2 h after ingestion of medium-sized (4 MJ), fluid meals containing either carbohydrate, protein, fat or water only. Measurements were carried out before meals and at regular post-meal intervals, during which mean arterial blood pressure was also followed. All energy-containing meals caused marked and gradually developing post-prandial increases in cardiac output as well as in superior mesenteric arterial flow. The maximum flow levels were reached in the course of 30–60 min and maintained until the observations ended after 2 h. The intake of water caused no such flow increases. There were considerable interpersonal variations in the size and in the speed of development of the flow increases after the three types of energy-containing meals. The flow-increasing effects of the three meal types were not significantly different, even if the most marked increases (median values about 1 1 min-1 for both cardiac output and superior mesenteric arterial flow) occurred after carbohydrate meals. The marked effects on circulation of the three food components were also revealed in the calculated, integrated amounts of ‘extra’ cardiac output and superior mesenteric arterial flow observed in the course of the 2 h following the meal. Values of more than 100 1 for such ‘extra’ flows were seen after carbohydrate meals. The marked ingestion-released increase in blood flow to the splanchnic organs is apparently partly met by an increase in cardiac output, and partly by some redistribution of flow, which benefits the digestive system. 相似文献