全文获取类型
收费全文 | 296158篇 |
免费 | 17269篇 |
国内免费 | 412篇 |
专业分类
耳鼻咽喉 | 4215篇 |
儿科学 | 10284篇 |
妇产科学 | 10263篇 |
基础医学 | 44972篇 |
口腔科学 | 7502篇 |
临床医学 | 24151篇 |
内科学 | 55752篇 |
皮肤病学 | 6310篇 |
神经病学 | 20991篇 |
特种医学 | 11633篇 |
外国民族医学 | 43篇 |
外科学 | 46669篇 |
综合类 | 7767篇 |
现状与发展 | 1篇 |
一般理论 | 160篇 |
预防医学 | 19895篇 |
眼科学 | 6945篇 |
药学 | 20875篇 |
中国医学 | 787篇 |
肿瘤学 | 14624篇 |
出版年
2018年 | 3611篇 |
2017年 | 2650篇 |
2016年 | 3074篇 |
2015年 | 3488篇 |
2014年 | 4571篇 |
2013年 | 7201篇 |
2012年 | 9057篇 |
2011年 | 9447篇 |
2010年 | 6125篇 |
2009年 | 5543篇 |
2008年 | 8669篇 |
2007年 | 9512篇 |
2006年 | 9359篇 |
2005年 | 8944篇 |
2004年 | 8656篇 |
2003年 | 8163篇 |
2002年 | 7761篇 |
2001年 | 13322篇 |
2000年 | 13647篇 |
1999年 | 11419篇 |
1998年 | 3023篇 |
1997年 | 2789篇 |
1996年 | 2633篇 |
1995年 | 2545篇 |
1994年 | 2343篇 |
1992年 | 8312篇 |
1991年 | 8454篇 |
1990年 | 8261篇 |
1989年 | 8079篇 |
1988年 | 7314篇 |
1987年 | 7075篇 |
1986年 | 6721篇 |
1985年 | 6518篇 |
1984年 | 4761篇 |
1983年 | 4120篇 |
1982年 | 2469篇 |
1979年 | 4428篇 |
1978年 | 3231篇 |
1977年 | 2733篇 |
1976年 | 2504篇 |
1975年 | 2837篇 |
1974年 | 3354篇 |
1973年 | 3362篇 |
1972年 | 3123篇 |
1971年 | 2950篇 |
1970年 | 2839篇 |
1969年 | 2585篇 |
1968年 | 2541篇 |
1967年 | 2375篇 |
1966年 | 2264篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
In der Behandlung von Frakturen spielt die Analgesie eine wesentliche Rolle. Es stellt sich daher die Frage, ob in der Klinik h?ufig eingesetzte Analgetika wie Tramadol oder Diclofenac negative Wirkungen auf die Knochenbruchheilung haben. 相似文献
103.
Is colonic electrical activity a similar phenomena to small-bowel electrical activity? 总被引:4,自引:0,他引:4
Dr. José A. S. Medeiros M.D. Ph.D. Fausto A. Pontes M.D. Ph.D. Octávio A. R. O. Mesquita 《Diseases of the colon and rectum》1997,40(1):93-99
PURPOSE: This study was designed to investigate colonic spike bursts regarding 1) their migration behavior, 2) their pressure correlates, and 3) comparing colonic short spike bursts with spike bursts from migrating myoelectric complex from the small bowel. METHODS: Rectosigmoid electromyography and manometry were recorded simultaneously in seven normal volunteers and electromyography alone in five others during two hours of fasting and for two hours after one 2,100-kJ meal. One patient with an ileostomy was also studied by the same method to record the migrating myoelectric complex from the terminal ileum during fasting. RESULTS: Three kinds of spike bursts were observed in the pelvic colon: rhythmic short spike bursts, migrating long spike bursts, and nonmigrating long spike bursts. The meal significantly increased the number of migrating and nonmigrating long spike bursts (from 25 to 38.7 percent of the recording time;
P
<0.01). These bursts of potentials showed a peak 15 minutes after the meal, which may be caused by the gastrocolic reflex. Migrating long spike bursts started anywhere along the rectosigmoid and migrated from there aborad 82 percent of the time and orad or in both directions in 10 or 7 percent of the time, respectively. They originated pressure waves 99 percent of the time. Short spike bursts were more frequent before the meal (15.1 percent before and 9.6 percent after the meal), but the difference was not significant; they neither propagated nor initiated pressure waves detected by the miniballoon. CONCLUSIONS: Migrating long spike bursts were the only potentials that migrated, sometimes for short distances. Short spike bursts are a different phenomenon from the small-bowel migrating myoelectric complex because they do not migrate; they can occur during the postprandial period and never originated intraluminal pressure waves.Supported by a grant from the Instituto Nacional de Investigação Científica, Proc. DBI-22086.Presented at the meeting of the Portuguese Congress of Gastrenterology, Vila Moura, Portugal, June 2 to 5, 1993. 相似文献
104.
Conditionally replicating luciferase reporter phages: improved sensitivity for rapid detection and assessment of drug susceptibility of Mycobacterium tuberculosis. 总被引:7,自引:1,他引:6
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
C Carrire P F Riska O Zimhony J Kriakov S Bardarov J Burns J Chan W R Jacobs Jr 《Journal of clinical microbiology》1997,35(12):3232-3239
TM4 is a lytic mycobacteriophage which infects mycobacteria of clinical importance. A luciferase reporter phage, phAE40, has been constructed from TM4 and was previously shown to be useful for the rapid detection and drug susceptibility testing of Mycobacterium tuberculosis. However, the lytic nature of the phage results in a loss of detectable light output and limits the sensitivity of detection. We describe several strategies aimed at improving the luciferase activity generated by TM4 luciferase phages, including (i) varying the position of the luciferase gene in the phage genome, (ii) isolating host-range mutants of the phage, and (iii) introducing temperature-sensitive mutations in the phage such that it will not replicate at the infecting temperature. Several new phages generated by these methods show increased intensity of luciferase production compared to the first-generation reporter phage phAE40, and one phage, phAE88, also demonstrates an enhanced duration of luciferase activity. This has allowed the detection of as few as 120 BCG cells and the determination of drug susceptibilities of M. tuberculosis in as little as 1 day. 相似文献
105.
O. Boerman W. Oyen G. Storm M Corvo L. van Bloois J. W M van der Meer F. Corstens 《Annals of the rheumatic diseases》1997,56(6):369-373
OBJECTIVES—Liposomes sterically stabilised with polyethylene glycol (PEG) labelled with technetium-99m were tested for their ability to image adjuvant arthritis in a rat model.
METHODS—Adjuvant arthritis was induced in the ankle joint of the left hind foot by injection of Mycobacterium butyricum in Freund's incomplete adjuvant in the foot pad. Seven days later animals received the following radiopharmaceuticals labelled with 99mTc (a) non-PEG-liposomes, (b) PEG-liposomes or (c) non-specific human polyclonal IgG. For each of the radiopharmaceuticals the in vivo distribution of the radiolabel was monitored both scintigraphically as well as by counting the dissected tissues at two, eight, and 24 hours after injection.
RESULTS—The pharmacokinetics of the radiopharmaceuticals differed considerably (half life in the blood: PEG-liposomes (18 hours) > 99mTc-IgG (3 hours) > non-PEG liposomes (1 hour)). The inflamed focus was visualised with each of the agents. The uptake of each of the radiopharmaceuticals in the inflamed ankle region correlated with their residence time in the blood (inflamed joint uptake: PEG liposomes (1.15% injected dose (ID)/g)>99mTc-IgG (0.35% ID/g)>non-PEG-liposomes (0.05% ID/g)). Quantitative analysis of the images showed that the inflamed ankle to background ratio was highest with the PEG-liposomes (7.5 at 24 hours after injection), while with the other two agents this ratio did not exceed 4.
CONCLUSION—This study shows that 99mTc-labelled PEG-liposomes may be an excellent agent to visualise arthritis. Increased label uptake in the inflamed joint and increased target to background ratios can be obtained with PEG-liposomes because of their long circulating properties. In addition to their use as vehicles for scintigraphic imaging of arthritis PEG-liposomes might also be used for the site specific delivery of antirheumatic drugs.
相似文献
METHODS—Adjuvant arthritis was induced in the ankle joint of the left hind foot by injection of Mycobacterium butyricum in Freund's incomplete adjuvant in the foot pad. Seven days later animals received the following radiopharmaceuticals labelled with 99mTc (a) non-PEG-liposomes, (b) PEG-liposomes or (c) non-specific human polyclonal IgG. For each of the radiopharmaceuticals the in vivo distribution of the radiolabel was monitored both scintigraphically as well as by counting the dissected tissues at two, eight, and 24 hours after injection.
RESULTS—The pharmacokinetics of the radiopharmaceuticals differed considerably (half life in the blood: PEG-liposomes (18 hours) > 99mTc-IgG (3 hours) > non-PEG liposomes (1 hour)). The inflamed focus was visualised with each of the agents. The uptake of each of the radiopharmaceuticals in the inflamed ankle region correlated with their residence time in the blood (inflamed joint uptake: PEG liposomes (1.15% injected dose (ID)/g)>99mTc-IgG (0.35% ID/g)>non-PEG-liposomes (0.05% ID/g)). Quantitative analysis of the images showed that the inflamed ankle to background ratio was highest with the PEG-liposomes (7.5 at 24 hours after injection), while with the other two agents this ratio did not exceed 4.
CONCLUSION—This study shows that 99mTc-labelled PEG-liposomes may be an excellent agent to visualise arthritis. Increased label uptake in the inflamed joint and increased target to background ratios can be obtained with PEG-liposomes because of their long circulating properties. In addition to their use as vehicles for scintigraphic imaging of arthritis PEG-liposomes might also be used for the site specific delivery of antirheumatic drugs.
相似文献
106.
Since 1987, 80 hydroxyapatite-coated (HA) cementless total hip prostheses have been implanted. Thirty patients were examined 21 months postoperatively and the results compared with data for uncoated prosthesis. Earlier mobilization and freedom from pain, together with evidence of bone ingrowth without connective tissue membrane formation, confirmed the benefits of HA-coated prostheses. 相似文献
107.
Summary Intracavitary application of ultrasound was first performed for diagnostic purposes in 1967; since that time, it has been
more and more widely used. As far as the gastrointestinal tract is concerned, endoscopically controlled ultrasonic probes
provide visualization of the various layers of the intestinal wall. It is therefore possible to describe lesions of the esophagus,
stomach, and the rectum with regard to their nature and depth of infiltration. Furthermore, periesophageal and perigastric
organs can be visualized. It has become evident that endosonography is particularly important for pretherapeutic staging of
tumors of the esophagus, stomach, and rectum. Here prospective comparative studies confirm the superiority of this new diagnostic
procedure when compared to the methods available to date. 相似文献
108.
109.
The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention. 相似文献
110.