全文获取类型
收费全文 | 2490篇 |
免费 | 138篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 114篇 |
妇产科学 | 72篇 |
基础医学 | 316篇 |
口腔科学 | 30篇 |
临床医学 | 229篇 |
内科学 | 525篇 |
皮肤病学 | 59篇 |
神经病学 | 119篇 |
特种医学 | 65篇 |
外科学 | 291篇 |
综合类 | 48篇 |
一般理论 | 1篇 |
预防医学 | 203篇 |
眼科学 | 62篇 |
药学 | 225篇 |
中国医学 | 33篇 |
肿瘤学 | 222篇 |
出版年
2023年 | 12篇 |
2022年 | 38篇 |
2021年 | 94篇 |
2020年 | 49篇 |
2019年 | 58篇 |
2018年 | 79篇 |
2017年 | 60篇 |
2016年 | 50篇 |
2015年 | 75篇 |
2014年 | 111篇 |
2013年 | 138篇 |
2012年 | 247篇 |
2011年 | 224篇 |
2010年 | 124篇 |
2009年 | 104篇 |
2008年 | 174篇 |
2007年 | 141篇 |
2006年 | 164篇 |
2005年 | 119篇 |
2004年 | 94篇 |
2003年 | 82篇 |
2002年 | 66篇 |
2001年 | 37篇 |
2000年 | 18篇 |
1999年 | 27篇 |
1998年 | 20篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 11篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 13篇 |
1985年 | 8篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1971年 | 10篇 |
1970年 | 5篇 |
排序方式: 共有2637条查询结果,搜索用时 15 毫秒
1.
2.
Krishna K. Singh Yuxin Dong John T. Belisle Jeffrey Harder Vijay K. Arora Suman Laal 《Clinical and Vaccine Immunology : CVI》2005,12(2):354-358
Serum samples obtained from human immunodeficiency virus (HIV)-infected tuberculosis (TB) patients months prior to clinical TB were used to delineate the profile of Mycobacterium tuberculosis culture filtrate proteins recognized during subclinical TB. A subset of ~12 antigens was recognized by antibodies in these serum samples. Antibodies to two of these antigens (81 [88]-kDa malate synthase [GlcB] and MPT51) were present in serum samples obtained during incipient subclinical TB in 19 (~90%) of the 21 HIV-infected TB patients tested. These antigens will be useful for devising diagnostic tests that can identify HIV-positive individuals who are at a high risk for developing clinical TB. 相似文献
3.
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
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.
Suman W Rathbun Thomas L Whitsett Gary E Raskob 《Blood coagulation & fibrinolysis》2007,18(8):795-800
The objective of this study was to test the safety of withholding anticoagulant treatment and additional call-back diagnostic testing with ultrasound in patients who have a negative D-dimer at presentation. Patients with signs and symptoms of deep-vein thrombosis who presented to the emergency department after regular hours and on weekends underwent D-dimer testing using the STA-Liatest D-di. In patients with negative D-dimer results, heparin therapy was withheld, and no further diagnostic testing for deep-vein thrombosis was done as part of the initial evaluation. Patients with positive D-dimer results underwent compression ultrasonography. The primary outcome measure was a diagnosis of new symptomatic venous thromboembolism confirmed by diagnostic testing during the 3-month follow-up period. Of the 260 eligible patients, 81 (31%) had a negative D-dimer and 179 (69%) had a positive D-dimer. No patient with a negative D-dimer at presentation had confirmed venous thromboembolism at 3-month follow-up. Three patients died: one by intracranial hemorrhage secondary to cerebrovascular accident; and two deaths of indeterminate cause almost 3 months after entry. The automated assay for D-dimer, the STA-Liatest D-di, seems to provide a simple method with high clinical utility for excluding acute first-episode deep-vein thrombosis in symptomatic patients who present to the emergency room after regular hours. 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.
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
9.
The immobilization of p-amino salicylic acid (PASA) on periodic oxidized cellulose (O.C) as a biocompatible carrier was investigated. The immobilization of the PASA is based on Schiff's base formation between the amino group of PASA and the aldehyde group of O.C. The in vivo and in vitro release of p-amino salicylic acid was studied. Such a system may be useful for the sustained delivery of the drugs in the body, since O.C. itself is a biosoluble carrier. 相似文献
10.
Correlation between Presence of Viable Bacteria and Presence of Endotoxin in Middle-Ear Effusions 总被引:8,自引:1,他引:8
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)
Jeffrey R. Dingman Mark G. Rayner Suman Mishra Yingze Zhang Miles D. Ehrlich J. Christopher Post Garth D. Ehrlich 《Journal of clinical microbiology》1998,36(11):3417-3419
The presence of endotoxin (detected by the Limulus amebocyte lysate assay) was compared to the presence of viable Haemophilus influenzae and Moraxella catarrhalis (detected by PCR) in 106 middle-ear effusions from pediatric patients with chronic otitis media. Endotoxin was found in 81 of the 106 specimens. Of these 81 specimens, 66 (81.5%) also tested positive for one or both of the gram-negative bacteria H. influenzae and M. catarrhalis. The data suggest that viable gram-negative bacteria, detectable by PCR but often undetectable by culture, may be the source of endotoxin in middle-ear effusions. 相似文献