全文获取类型
收费全文 | 4698篇 |
免费 | 226篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 307篇 |
妇产科学 | 87篇 |
基础医学 | 582篇 |
口腔科学 | 107篇 |
临床医学 | 345篇 |
内科学 | 1144篇 |
皮肤病学 | 105篇 |
神经病学 | 166篇 |
特种医学 | 249篇 |
外科学 | 641篇 |
综合类 | 187篇 |
一般理论 | 1篇 |
预防医学 | 214篇 |
眼科学 | 167篇 |
药学 | 300篇 |
1篇 | |
中国医学 | 16篇 |
肿瘤学 | 264篇 |
出版年
2023年 | 29篇 |
2022年 | 75篇 |
2021年 | 159篇 |
2020年 | 75篇 |
2019年 | 122篇 |
2018年 | 152篇 |
2017年 | 100篇 |
2016年 | 119篇 |
2015年 | 134篇 |
2014年 | 169篇 |
2013年 | 211篇 |
2012年 | 325篇 |
2011年 | 319篇 |
2010年 | 185篇 |
2009年 | 149篇 |
2008年 | 238篇 |
2007年 | 255篇 |
2006年 | 196篇 |
2005年 | 168篇 |
2004年 | 158篇 |
2003年 | 141篇 |
2002年 | 127篇 |
2001年 | 94篇 |
2000年 | 101篇 |
1999年 | 84篇 |
1998年 | 51篇 |
1997年 | 42篇 |
1996年 | 34篇 |
1995年 | 24篇 |
1994年 | 39篇 |
1993年 | 26篇 |
1992年 | 61篇 |
1991年 | 75篇 |
1990年 | 57篇 |
1989年 | 84篇 |
1988年 | 54篇 |
1987年 | 51篇 |
1986年 | 52篇 |
1985年 | 48篇 |
1984年 | 29篇 |
1983年 | 28篇 |
1982年 | 33篇 |
1980年 | 18篇 |
1979年 | 27篇 |
1978年 | 14篇 |
1977年 | 21篇 |
1976年 | 28篇 |
1975年 | 17篇 |
1973年 | 16篇 |
1966年 | 14篇 |
排序方式: 共有4940条查询结果,搜索用时 15 毫秒
61.
Aloe vera affects changes induced in pulmonary tissue of mice caused by cigarette smoke inhalation 下载免费PDF全文
This study was undertaken to determine the influence of Aloe vera (AV) on changes induced in pulmonary tissue of cigarette smoke (CS) inhaling mice. CS inhalation for 4 weeks caused pulmonary damage as evident by histoarchitectural alterations and enhanced serum and tissue lactate dehydrogenase (LDH) activities. CS inhalation also led to increased mucin production as revealed by mucicarmine and Alcian Blue‐Periodic Acid Schiff (AB‐PAS) staining. Studies on bronchoalveolar lavage fluid (balf) of CS exposed animals revealed structural changes in phospholipids and increase in surface tension when compared with control counterparts. These changes were accompanied by enhanced nitric oxide (NO) levels, citrulline levels, peroxidative damage, and differential modulation of antioxidant defense system. AV administration (seven weeks, 500 mg/kg b.w. daily) to CS inhaling mice led to modulation of CS induced pulmonary changes as revealed by lesser degree of histoarchitectural alterations, lesser mucin production, decreased NO levels, citrulline levels, peroxidative damage, and serum LDH activity. AV treatment to CS inhaling mice was associated with varying response to antioxidant defense system, however balf of CS + AV treated animals did not exhibit appreciable changes when compared with that of CS exposed animals. These observations suggest that AV has the potential to modulate CS induced changes in the pulmonary tissue which could have implications in management of CS associated pulmonary diseases, however, further investigations are required to explore its complete mechanism of action. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 999–1013, 2015. 相似文献
62.
Meaghann S. Weaver MD Ramandeep S. Arora MBBS Scott C. Howard MD Msc Carmen E. Salaverria MPsych Yen‐Lin Liu MD Raul C. Ribeiro MD Catherine G. Lam MD MPH 《Pediatric blood & cancer》2015,62(4):565-570
Treatment abandonment, the failure to complete therapy that is required for definitive disease control, frequently causes treatment failure for pediatric patients in low‐ and middle‐income countries with chronic conditions, particularly cancer. Other forms of incomplete treatment affecting children in all settings, such as nonadherence and loss to follow‐up, are often confused with treatment abandonment. Unclear definitions of incomplete treatment dramatically affect reported outcomes. To facilitate disease‐specific and cross‐sector analyses, we outline a practical approach to categorize forms of incomplete treatment, present distinct semantic categories with case examples and provide an algorithm that could be tailored to disease‐ and context‐specific needs. Pediatr Blood Cancer 2015;62:565–570. © 2015 Wiley Periodicals, Inc. 相似文献
63.
64.
Kazimierz O. Wrzeszczynski Vanessa Felice Avinash Abhyankar Lukasz Kozon Heather Geiger Dina Manaa Ferrah London Dino Robinson Xiaolan Fang David Lin Michelle F. Lamendola-Essel Depinder Khaira Esra Dikoglu Anne-Katrin Emde Nicolas Robine Minita Shah Kanika Arora Olca Basturk Vaidehi Jobanputra 《The Journal of molecular diagnostics : JMD》2018,20(6):822-835
65.
B. S. Arora Ekta Sharma S. K. Agrawal Madhunika Agrawal 《Indian journal of pharmaceutical sciences》2015,77(6):792-795
The present study was designed to evaluate the in vitro cytotoxic effect of methanol extract of aerial parts including stems, leaves and twigs of Aralia cachemirica and purified continentalic acid isolated from this extract against a panel of human cancer cell lines of varied tissues. Percentage of growth inhibition was evaluated by sulphorhodamine B assay. Purified continentalic acid showed moderate cytotoxicity against all the cell lines used. In contrast, the extract exhibited significant concentration dependant cytotoxicity against A-549 (lung), THP-1 (leukemia) and MCF-7 (breast) cell lines. This work highlights cytotoxic potential of this extract, which can further be explored for different constituents for their possible use autonomously or in combined manner in cancer therapy. The detailed analysis of their cytotoxicity has been presented in this paper. 相似文献
66.
Arora Shiyana Dharavath Ravinder Naik Bansal Yashika Bishnoi Mahendra Kondepudi Kanthi Kiran Chopra Kanwaljit 《Metabolic brain disease》2021,36(6):1315-1330
Metabolic Brain Disease - The night shift paradigm induces a state of chronic partial sleep deprivation (CPSD) and enhances the vulnerability to neuronal dysfunction. However, the specific neuronal... 相似文献
67.
The effects of respiratory movements on the ultrasonic echoes of the cardiac structures were recorded and analyzed in 50 consecutive patients. Deep inspiration in cooperative patients resulted in a considerable increase of dense anterior echoes, with blotting out of any distal or posterior echoes in 12 of 44 patients (group A). In the second or larger series (32 of 44 patients; group B), a posterior displacement of most of the identifiable intrinsic cardiac echoes was seen with deep inspiration, particularly those of the posterior wall of the left ventricle. Forced expiration produced an opposite or anterior displacement of the cardiac echoes. Normal respirations showed similar but smaller excursions. 相似文献
68.
M Nair R Arora J C Mohan G S Kalra K K Sethi M Nigam M Khalilullah 《International journal of cardiology》1991,32(3):389-394
Cross-sectional and Doppler echocardiography are currently the most important non-invasive tests for the evaluation of mitral stenosis. Recent experience has, however, shown that parameters that are reliable before mitral valvotomy may not be valid after the procedure. We have studied the validity of estimation of the area of the mitral valve by echo-planimetry, by Doppler pressure half time and the transmitral end-diastolic pressure gradient calculated by continuous wave Doppler in 100 patients (aged 10-30 years) before and after balloon mitral valvoplasty (n = 70) or surgical closed mitral valvotomy (n = 30). These patients underwent cardiac catheterisation and echocardiographic studies before, immediately after and 8-12 (9.3 +/- 2.2) weeks following balloon valvoplasty or closed valvotomy. The area as estimated echocardiographically correlated well with that obtained by the Gorlin formula before (r = 0.80), but not immediately after (r = 0.67) or on follow up after mitral valvotomy. There was good correlation between Doppler pressure half time and the area as estimated by the Gorlin formula before (r = 0.89) and on follow up after valvotomy (r = 0.82), but the correlation was not as good in the immediate period after valvotomy (r = 0.60). The end-diastolic pressure gradients obtained by Doppler examination and at cardiac catheterisation correlated well with each other before (r = 0.94), immediately after valvotomy (r = 0.92) and on follow up (r = 0.94). Hence, the reliability of estimation of the area of the mitral valve by echo-planimetry and by Doppler pressure half time varies according to the time at which the examination is performed following commissurotomy.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
69.
K K Arora J P Lacy R A Schacht D G Martin C F Gutch 《Archives of internal medicine》1975,135(4):603-605
Four uremic patients on maintenance hemodialysis developed intractable heart failure and atrioventricular block. All had persistently high (over 60) calcium-phosphorus products. At autopsy, all had metastatic myocardial calcification. Their inability to take phosphate-binding agents orally is responsible for this fatal complication. 相似文献
70.
Clinical manifestations of aortoarteritis (Takayasu's arteritis) are varied, depending on the involved segment of the aorta and its branches. A case of a young Indian woman with aortoarteritis presenting primarily with hypoparathyroidism is reported. Aortogram showed total occlusion of the arch arteries. To the best of our knowledge, the occurrence of hypoparathyroidism in aortoarteritis has not been reported. Possible mechanisms of such an involvement are discussed. 相似文献