全文获取类型
收费全文 | 3372089篇 |
免费 | 241887篇 |
国内免费 | 8551篇 |
专业分类
耳鼻咽喉 | 46496篇 |
儿科学 | 112625篇 |
妇产科学 | 93437篇 |
基础医学 | 473833篇 |
口腔科学 | 92615篇 |
临床医学 | 306403篇 |
内科学 | 662126篇 |
皮肤病学 | 78659篇 |
神经病学 | 273953篇 |
特种医学 | 130529篇 |
外国民族医学 | 1282篇 |
外科学 | 506721篇 |
综合类 | 70048篇 |
现状与发展 | 6篇 |
一般理论 | 1235篇 |
预防医学 | 258568篇 |
眼科学 | 76002篇 |
药学 | 248144篇 |
9篇 | |
中国医学 | 6794篇 |
肿瘤学 | 183042篇 |
出版年
2019年 | 26065篇 |
2018年 | 36800篇 |
2017年 | 28185篇 |
2016年 | 32335篇 |
2015年 | 36438篇 |
2014年 | 50268篇 |
2013年 | 75944篇 |
2012年 | 101568篇 |
2011年 | 107637篇 |
2010年 | 64905篇 |
2009年 | 62047篇 |
2008年 | 101047篇 |
2007年 | 107540篇 |
2006年 | 109053篇 |
2005年 | 104974篇 |
2004年 | 101593篇 |
2003年 | 98126篇 |
2002年 | 94975篇 |
2001年 | 161465篇 |
2000年 | 165902篇 |
1999年 | 140417篇 |
1998年 | 40332篇 |
1997年 | 35863篇 |
1996年 | 36077篇 |
1995年 | 34786篇 |
1994年 | 32234篇 |
1993年 | 30214篇 |
1992年 | 110266篇 |
1991年 | 106484篇 |
1990年 | 103454篇 |
1989年 | 99882篇 |
1988年 | 91678篇 |
1987年 | 89988篇 |
1986年 | 84187篇 |
1985年 | 80467篇 |
1984年 | 60171篇 |
1983年 | 50961篇 |
1982年 | 29972篇 |
1981年 | 27080篇 |
1979年 | 53429篇 |
1978年 | 37581篇 |
1977年 | 32043篇 |
1976年 | 29704篇 |
1975年 | 31740篇 |
1974年 | 37401篇 |
1973年 | 35652篇 |
1972年 | 33333篇 |
1971年 | 30742篇 |
1970年 | 28621篇 |
1969年 | 26984篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
The experimental and clinical results of the self-expanding nitinol coil stent have been reviewed. Animal data have shown that the stent is safe and provokes a mild proliferative response, similar to previously studied balloon-expandable stents. Data from femoral and popliteal arteries are supportive of long-term patency in these arteries, which are typically associated with unfavorable results from other stents. Data from coronary implantations in patients show that the stent can be safely used to treat coronary lesions of both simple and complex natures. Long-term results of these patients compare favorably with existing data in similar lesions using other stents. A larger clinical trial using the new flat wire design stent is required to test whether further stent expansion may contribute to low restenosis rates. 相似文献
992.
Doing it right the first time: quality improvement and the contaminant blood culture. 总被引:5,自引:3,他引:2 下载免费PDF全文
F I Weinbaum S Lavie M Danek D Sixsmith G F Heinrich S S Mills 《Journal of clinical microbiology》1997,35(3):563-565
The aim of the project was to determine whether the rate of contaminant blood cultures could be reduced by using a team of dedicated phlebotomists. Comparisons were made between adult patients requiring blood cultures for suspected bacteremia on medical and surgical units before and after the introduction and withdrawal of a dedicated blood culture team. The results showed that a significant reduction in the contaminant blood culture rate was achieved by the blood culture team (P < 0.001; chi(2) test). Therefore, in our experience, the rate of contaminant blood cultures can be reduced in a teaching hospital by using a team of dedicated phlebotomists. Calculations made with our data and those published by others suggest that cost savings from reducing false-positive blood cultures are greater than the cost of the blood culture team. 相似文献
993.
A new implantable bladder volume-monitoring device based on the impedance measurement of the detrusor muscle is described.
The system is completely autonomous and forms a mixed-signal (analogue/digital) feedback loop with a neuro-stimulator to rectify
bladder dysfunctions (incontinence and retention) through neuromuscular stimulation techniques. A programmable instrumentation
amplifier and a signal processing block, to eliminate the artefacts caused by the patient’s movements, have been designed
and tested. The layout for the signal processing block has been realised in 0.8 μm BiCMOS technology. 相似文献
994.
M. D. Mashkovskii V. A. Parshin R. B. Parimbetova 《Bulletin of experimental biology and medicine》1997,123(3):257-259
It is found that the cholinomimetic aceclidine stimulates learning and memory processes and exerts antiamnestic effect in
rats with conditioned avoidance reaction. The effect of aceclidine is not inferior to that of amiridin and surpasses that
of physostigmine.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 296–298, March, 1997 相似文献
995.
A 60-year-old man developed hemiballismus due to an intracranial hemorrhage involving the subthalamic nucleus 8 weeks after orthotopic liver transplantation. The hemorrhage was thought to be due to alterations in cerebral blood flow following a period of hypotensive shock due to sepsis, in the presence of anticoagulant therapy and thrombocytopenia. This represents a rare neurologic complication of liver transplantation. 相似文献
996.
S. NIKOLOVSKI D. L. FAULKNER T. N. PALMER P. A. FOURNIER 《Acta physiologica (Oxford, England)》1996,157(4):427-434
During recovery from high intensity exercise, substantial and rapid muscle glycogen repletion from endogenous carbon sources is reported in a variety of vertebrate species, the rat being the only reported exception. The major aim of this study was to re-examine the process of glycogen repletion during recovery from high intensity exercise in the rat. In response to 3 min of vigorous swimming, muscle glycogen concentrations decrease markedly from initial levels of 20.2±1.5 and 21.2±0.9 μmol g-1 to 6.4±1.1 and 7.9±1.4 μmol g-1 in the tibialis anterior and plantaris muscles respectively. The equivalent of 58% of the glycogen carbons mobilized during exercise by the plantaris and 73% of that mobilized by the tibialis anterior muscle is repleted within 1 h following exercise. Using the hepatectomized rat as experimental model, a secondary aim of the study was to evaluate whether the liver is essential for the repletion of muscle glycogen. Although the absence of significant differences in the magnitude of post-exercise muscle glycogen repletion between sham-operated and hepatectomized rats suggests that the resynthesis of muscle glycogen can take place in the absence of hepatic gluconeogenesis, the present study identifies several limitations in the use of acute hepatectomy. Overall, the present study indicates that, in contrast to published views, the rat resembles other vertebrates in that it can support extensive muscle glycogen repletion from endogenous carbon sources during the recovery phase following high intensity exercise. 相似文献
997.
Paul P. W. van Buul Iris M. Zandman Mira Grigorova Jan J. W. A. Boei Adayapalam T. Natarajan 《Chromosome research》1995,3(7):427-432
The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescencein situ hybridization analysis of mitotic or meiotic stages. Specific DNA libraries for chromosomes 1, 11 and 13 were used. The results obtained indicate that (a) chromosomes 1, 11 and 13 are more involved in multivalent formation than expected on the basis of DNA content and (b) if the mitotic FISH analysis data are corrected for the observed over-representation, the frequencies of induced translocations are similar to those recorded in the classical multivalent studies, suggesting equal scoring efficiencies in both systems. 相似文献
998.
P. Lamesch A. Lamesch 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1993,378(3):171-177
We report on the case of a 6-year-old girl admitted as an emergency with an acute abdomen with the diagnosis of peritonitis; clinical examination under anesthesia revealed the presence of an abdomino-pelvic mass. Laparotomy confirmed the diagnosis of torsion of an ectopic spleen. Splenectomy was required because the spleen was gangrenous. A review of the literature from 1896 to 1990 revealed reports of 74 cases. Epidemiology, etiology, pathophysiology, the diagnostic and therapeutic problems are discussed.
Ektopische Milz beim Kind: Fallbericht und Literaturübersicht 1896–1990
Zusammenfassung Anhand eines Fallberichtes und einer Literaturübersicht über 74 Fälle werden Epidemiologie, Ätiologie, Pathophysiologie, Diagnostik und Therapie der im Kindesalter sehr seltenen ektopen Milz besprochen. Die klinischen Zeichen reichen von unspezifischen abdominellen Beschwerden bis hin zum Vollbild eines akuten Abdomen (50%). Die praeoperative Diagnostik richtet sich nach Klinik, Abdomenleeraufnahme und Sonographie, evtl. Computertomographie. Aufgrund der hohen Torsionsraten besteht generell eine Operationsindikation, wobei die Entscheidung über Splenopexie oder Splenektomie sich an dem Lokalbefund orientieren sollte. Zur Splenopexie wurden mehrere Techniken mit gleich guten Resultaten angegeben.相似文献
999.
Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34±0.06 cm2, 0.35±0.08 cm2 and 1.37±0.48 cm2 respectively. The average minimal cross-sectional area was 0.29±0.06 cm2. The minimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal tubinates in 21 of the 35 children. As would be expected, the cross-sectional areas at different sites of the nasal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm2 per year, the nasopharyngeal cross-sectional area increased by 0.20 cm2 per year. No significant differences were found between boys and girls. Measurements of the posterior nasal and nasopharyngeal cross-sectional areas were unreliable, whenever the minimal cross-sectional area was less than 0.2 cm2. Furthermore, assessment of the nasopharynx may be difficult because of involuntary movements of the soft palate. 相似文献
1000.
H. D. Tagare K. W. Elder D. M. Stoner R. M. Patterson C. L. Nicodemus S. F. Viegas Dr. G. R. Hillman 《Annals of biomedical engineering》1993,21(6):715-726
The carpal regions of ten cadaver extremities were imaged by CT. The images were combined into a 3-dimensional model of the
carpus using a technique based on a dynamic programming algorithm to find an optimal estimate of the location of the bone
boundaries in the CT images. The resulting set of surface points on each bone was used to compute volumes and principal and
antipodal axes for the bones. A spatial coordinate system was established based on the positions of the centroids of three
bones in the distal carpal row. The angular orientations of all carpal bones were determined with respect to this system.
The principal axes for the same bone among ten wrist specimens proved to be more widely dispersed than the antipodal axes
for the same bones. The antipodal axes also correspond more closely to an intuitive notion of the “longest axis” of the bones.
We conclude that the antipodal axis is a more reliable and useful measure of bone orientation than the principal axis. 相似文献