全文获取类型
收费全文 | 2887篇 |
免费 | 148篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 141篇 |
妇产科学 | 50篇 |
基础医学 | 354篇 |
口腔科学 | 79篇 |
临床医学 | 209篇 |
内科学 | 596篇 |
皮肤病学 | 57篇 |
神经病学 | 172篇 |
特种医学 | 87篇 |
外科学 | 426篇 |
综合类 | 56篇 |
一般理论 | 2篇 |
预防医学 | 177篇 |
眼科学 | 65篇 |
药学 | 279篇 |
中国医学 | 42篇 |
肿瘤学 | 183篇 |
出版年
2023年 | 15篇 |
2022年 | 47篇 |
2021年 | 82篇 |
2020年 | 40篇 |
2019年 | 74篇 |
2018年 | 88篇 |
2017年 | 73篇 |
2016年 | 71篇 |
2015年 | 78篇 |
2014年 | 109篇 |
2013年 | 142篇 |
2012年 | 241篇 |
2011年 | 232篇 |
2010年 | 140篇 |
2009年 | 108篇 |
2008年 | 159篇 |
2007年 | 159篇 |
2006年 | 177篇 |
2005年 | 139篇 |
2004年 | 127篇 |
2003年 | 125篇 |
2002年 | 85篇 |
2001年 | 55篇 |
2000年 | 41篇 |
1999年 | 26篇 |
1998年 | 23篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1992年 | 23篇 |
1991年 | 22篇 |
1990年 | 23篇 |
1989年 | 13篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 19篇 |
1985年 | 13篇 |
1984年 | 19篇 |
1983年 | 19篇 |
1982年 | 13篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 20篇 |
1978年 | 15篇 |
1977年 | 7篇 |
1976年 | 13篇 |
1974年 | 9篇 |
1971年 | 20篇 |
1970年 | 7篇 |
1969年 | 10篇 |
排序方式: 共有3045条查询结果,搜索用时 15 毫秒
1.
2.
Sajja Lokeswara Rao Mannam Gopichand Sompali Sriramulu Reddy Karri Venkata Ravirala Bala Raju Raju Bhupathiraju Soma Raju Penmetcha Krishnam 《Indian Journal of Thoracic and Cardiovascular Surgery》2004,20(4):173-177
Background Cardiopulmonary bypass (CPB) may contribute to the complications and it is assumed that eliminating cardiopulmonary bypass
has the potential of reducing post operative morbidity after coronary artery bypass grafting (CABG). The study was carried
out to compare mortality and morbidity in the off-pump and on-pump CABG groups.
Methods We prospectively analysed 200 patients undergoing CABG. Group A consists of 100 patients underwent multi-vessel off-pump CABG
and group B consists of 100 patients underwent CABG with CPB. The incidence of complications (mortality, re-exploration for
bleeding, myocardial infarction, atrial fibrillation, neurological events, new onset renal failure (s. creatinine>1.6 mg/dL)
pulmonary complications, length of ICU stay and hospital stay were recorded, analysed and compared.
Results OPCAB patients received 2.73±0.61 grafts/patient and on-pump CABG patients received 3.39±0.75 grafts/patient (p value<0.00001). There was no significant statistical difference in mortality, incidence of stroke between OPCAB and CABG
with CPB patients. Length of ICU stay was 32.84±4.22 vs 44.85±7.18 hrs (p value<0.00001) and hospital stay was 6.52±0.69 vs 7.94±0.92 days (p value<0.00001) between group A and group B respectively. Incidence of atrial fibrillation was less in OPCAB group 7% vs 12%
although it was statistically not significant (p value 0.33). It was observed in our study that there was no significant deference in worsening of existing renal failure
between on-pump CABG and OPCAB 6% vs 2% (P value 0.28). Blood utilization was significantly less in OPCAB group (p value<0.001).
Conclusion There was no statistically significant difference in terms of mortality, incidence of stroke and new onset renal failure in
both groups. But there was lesser incidence of post operative atrial fibrillation, worsening of existing renal failure in
off-pump group though statistically not significant. There was significant reduction in blood utilization, length of ICU and
hospital stay in OPCAB group. 相似文献
3.
Brian F O'Reilly Ameet Kishore John A Crowther Colin Smith 《Otology & neurotology》2004,25(5):791-796
OBJECTIVE: To examine the relationship between growth rate of vestibular schwannomas and the expression of various growth factor receptors. STUDY DESIGN: Retrospective case review of clinical growth rate in conjunction with a histopathologic and immunohistochemical reexamination of archival specimens. SETTING: A tertiary referral neurotologic center. PATIENTS: Three groups: a historical group to act as controls, consisting of 30 patients with sporadic vestibular schwannomas removed before the unit adopted an initial interval scan policy; a group of 14 patients with sporadic vestibular schwannomas who had undergone an initial interval scan policy, showed radiologic evidence of growth, and therefore had their schwannoma removed; and a group of 16 schwannomas removed from 11 neurofibromatosis Type 2 patients. MAIN OUTCOME MEASURES: A comparison between the three clinical groups using immunohistochemical studies to determine the level of expression of the proliferation factor Ki-67, c-erbB-2, and c-erbB-3 receptors and fibroblastic growth factor receptors 1 and 4. RESULTS: The level of expression of the proliferation factor Ki-67 was very low and similar in all three groups. C-erbB-2 and c-erbB-3 receptors were not expressed in any of the groups. fibroblastic growth factor receptor 4 expression was not significantly different, but there was a variation in the expression of fibroblastic growth factor receptor 1 between the three groups that correlated well with the differing incidence of growth in the groups. The increase in expression of fibroblastic growth factor receptor 1 in the neurofibromatosis Type 2 group was not statistically significant, but the increase in expression of fibroblastic growth factor receptor 1 in the growing sporadic group was statistically significant when compared with the historical controls. The level of fibroblastic growth factor receptor 1 expression correlates significantly with the rate of growth as measured on interval magnetic resonance imaging. CONCLUSIONS: Overexpression of fibroblastic growth factor receptor 1 has a positive correlation with the incidence and the rate of growth of sporadic vestibular schwannomas. 相似文献
4.
Madhu Bala Harish Chandra Goel 《Journal of environmental pathology, toxicology and oncology》2004,23(2):139-144
Recent reports showed that whole extract of Podophyllum hexandrum was radioprotective in mice. Podophyllotoxin is one of the major constituents of the whole extract of Podophyllum. In this study we report on the radioprotective action of podophyllotoxin in Saccharomyces cerevisiae yeast. Proliferating yeast cells pretreated with podophyllotoxin (2.5-5.0 microg/mL) for > or =3 hours showed a higher surviving fraction after (60)Co-gamma-irradiation (200-600 Gy) than did the irradiated cells not pretreated with podophyllotoxin. The maximum increase (2.0 times) in surviving fraction was observed in cells treated with 2.5 microg/mL podophyllotoxin, 5 hours before (60)Co-gamma-irradiation (400 Gy). Podophyllotoxin was not mutagenic or recombinogenic at radioprotective doses (2.5 microg/mL). A post-irradiation decrease in revertants and gene convertants was observed in cells treated with podophyllotoxin (2.5 microg/mL podophyllotoxin, -5 hours, 400 Gy). This study indicates that podophyllotoxin is radioprotective in yeast, and its radioprotective effects in higher eukaryotes would be worth investigating. 相似文献
5.
Bala V. Manyam 《Epilepsia》1992,33(3):473-475
The ancient Indian medical system, Ayurveda, meaning science of life, is the oldest system of medicine in the world. Epilepsy is defined as Apasmara: apa, meaning negation or loss of; smara, meaning recollection or consciousness. Aura was recognized and was called Apasmara Poorva Roopa. A large number of symptoms indicative of aura were listed. Worthy of mention are subjective sensation of sounds, sensation of darkness, feeling of delusion, and dream-like state. An actual attack of Apasmara includes falling down; shaking of the hands, legs, and body; rolling up of the eyes; grinding of the teeth; and foaming at the mouth. Four major types of epilepsy based on the disturbance of doshas (humors) that govern the physiological and physiochemical activities of the body are mentioned. Apasmara is considered a dangerous disease that is chronic and difficult to treat. Several causes are mentioned. Treatment included correcting the etiological factors and dietary regimen and avoiding dangerous places that may result in injuries. 相似文献
6.
Paolo R. Salvalaggio Katie Neighbors Susan Kelly Karan M. Emerick Kishore Iyer Riccardo A. Superina Peter F. Whitington Estella M. Alonso 《American journal of transplantation》2005,5(8):1868-1874
The Pediatric End-Stage Liver Disease (PELD) score was designed to reduce subjectivity in liver allocation and to advantage patients with a higher probability of waiting list mortality. The aims of this study were to determine the impact of PELD implementation for children with chronic liver disease and to assess whether PELD met its goal of standardization of liver allocation for children. This study used data reported to the United Network for Organ Sharing (UNOS) registry for children with chronic liver disease receiving primary cadaveric liver transplant between January 2000 and December 2001 (pre-PELD) and March 2002 and July 2003 (PELD). PELD reduced the percentage of children transplanted while in an intensive care unit and as status 1. A calculated PELD score was used for allocation in only 52% of recipients. Thirty percent were status 1 at transplant and PELD scores granted by exception were used for allocation in 18% of patients. There was regional variation in PELD score at allocation and use of exception scores with a significant relationship between PELD score and percentage of exception cases. Regional variation suggests that PELD has not resulted in standardization of listing practices in pediatric liver transplantation. 相似文献
7.
Six patients with prolonged acute courses of thrombotic microangiopathy are reviewed. These patients had in common courses of acute disease requiring plasma support for more than 3 months, with subsequent complete remission. Plasma support requirements may be prodigious, and the acute course may require more than 100 plasma exchanges before a stable remission is achieved. These patients appear to represent a subset of thrombotic microangiopathy distinct from the more common acute T.T.P. course, which resolves in 3–6 weeks, and the chronic relapsing pattern, which may have a short or prolonged acute course. © 1992 Wiley-Liss, Inc. 相似文献
8.
Sudhakar B. Ogale Satyabhushan Mahajan Kishore B. Sandu Nityananda Babu 《Indian journal of otolaryngology and head and neck surgery》1997,49(2):154-156
Tympanosclerosis (TS) is a common sequelae of chronic otitis media found in all age groups. Over a period of 3 years, out of 520 surgical cases, 68 (13%) were found to have varying amounts of Tympanosclerotic plaques (TSP) warranting surgical removal. 60% had extension of TSP over the ossicular chain thus affecting its mobility. Deliberate surgical removal of TSP was undertaken for hearing improvement. Systematic and meticulous removal of TSP rather than en-bloc removal has been found to improve the hearing as close to as in, non-tympanosclerotic ear surgery. 相似文献
9.
Inhibition of positively rewarding behavior by the heightened aggressive state evoked either by pain-inducing stimulus or septal lesion 总被引:1,自引:0,他引:1
Using a footshock elicited aggression paradigm, aggressive responses were scored in normal and in septal-lesioned adult male Wistar rats. Septal lesions were made electrolytically to include the medial and lateral septal nuclei. The lesion was confirmed by behavioral criteria (septal aggression) and post-mortem histology. The aggressive response types (threat, attack) of the septal animals were compared with their corresponding age and weight matched controls. Results showed a statistically significant increase (P = 0.05) in the number of attack responses but not the threat responses in septal animals. The modulatory role of the aggressive experience on responsiveness to positively rewarding or hedonic stimuli was assessed by quantifying the intracranial self-stimulation (SS) rates that were obtained before and after an aggression schedule. For testing the SS behavior bipolar electrodes were implanted in the ventral tegmental area--substantia nigra (VTA-SN). Results showed a decrease in SS pedal press rates in post-aggression schedule as compared to the pre-aggression period in the normal subjects. This depressing effect lasted for over a week. In septal lesioned rats the SS rates were virtually abolished even without having an aggressive schedule. These experiments revealed the effect of environment and of a brain area in provoking aggressive mood and its inhibitory consequence on responding for positive experience. 相似文献
10.
Colonization of America by Drosophila subobscura: Experiment in natural populations that supports the adaptive role of chromosomal-inversion polymorphism 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Prevosti A Ribo G Serra L Aguade M Balaña J Monclus M Mestres F 《Proceedings of the National Academy of Sciences of the United States of America》1988,85(15):5597-5600
North America and South America have recently been colonized by the Palearctic species Drosophila subobscura. This double colonization offers a rare opportunity for evolutionary studies. Correlations between chromosomal arrangement frequencies and latitude were calculated for the colonizing populations. Signs of these correlations are highly coincident with those found in the Old World. These results provide experimental support for the adaptive value of the chromosomal-inversion polymorphism; historical and other nonadaptive explanations are thus excluded or relegated to a secondary role. 相似文献