全文获取类型
收费全文 | 1204篇 |
免费 | 59篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 51篇 |
妇产科学 | 78篇 |
基础医学 | 78篇 |
口腔科学 | 25篇 |
临床医学 | 93篇 |
内科学 | 279篇 |
皮肤病学 | 11篇 |
神经病学 | 74篇 |
特种医学 | 80篇 |
外科学 | 291篇 |
综合类 | 21篇 |
预防医学 | 56篇 |
眼科学 | 21篇 |
药学 | 67篇 |
中国医学 | 16篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 51篇 |
2020年 | 19篇 |
2019年 | 25篇 |
2018年 | 44篇 |
2017年 | 27篇 |
2016年 | 36篇 |
2015年 | 39篇 |
2014年 | 64篇 |
2013年 | 73篇 |
2012年 | 83篇 |
2011年 | 80篇 |
2010年 | 57篇 |
2009年 | 40篇 |
2008年 | 64篇 |
2007年 | 82篇 |
2006年 | 86篇 |
2005年 | 75篇 |
2004年 | 57篇 |
2003年 | 34篇 |
2002年 | 50篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 15篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1274条查询结果,搜索用时 15 毫秒
41.
Marwan Abdul Hakim Shaah Md. Sohrab Hossain Faisal Aboelksim Salem Allafi Alyaa Alsaedi Norli Ismail Mohd Omar Ab Kadir Mardiana Idayu Ahmad 《RSC advances》2021,11(40):25018
There is increasing concern regarding alleviating world energy demand by determining an alternative to petroleum-derived fuels due to the rapid depletion of fossil fuels, rapid population growth, and urbanization. Biodiesel can be utilized as an alternative fuel to petroleum-derived diesel for the combustion engine. At present, edible crops are the primary source of biodiesel production. However, the excessive utilization of these edible crops for large-scale biodiesel production might cause food supply depletion and economic imbalance. Moreover, the utilization of edible oil as a biodiesel feedstock increases biodiesel production costs due to the high price of edible oils. A possible solution to overcome the existing limitations of biodiesel production is to utilize non-edible crops oil as a feedstock. The present study was conducted to determine the possibility and challenges of utilizing non-edible oil as a potential feedstock for biodiesel production. Several aspects related to non-edible oil as a biodiesel feedstock such as overview of biodiesel feedstocks, non-edible oil resources, non-edible oil extraction technology, its physicochemical and fatty acid properties, biodiesel production technologies, advantages and limitation of using non-edible oil as a feedstock for biodiesel production have been reviewed in various recent publications. The finding of the present study reveals that there is a huge opportunity to utilize non-edible oil as a feedstock for biodiesel production.There is increasing concern regarding alleviating world energy demand by determining an alternative to petroleum-derived fuels due to the rapid depletion of fossil fuels, rapid population growth, and urbanization. 相似文献
42.
Muhammad Umar Aslam Khan Mohsin Ali Raza Hassan Mehboob Mohammed Rafiq Abdul Kadir Saiful Izwan Abd Razak Saqlain A. Shah Muhammad Zahir Iqbal Rashid Amin 《RSC advances》2021,11(30):18615
Correction for ‘Development and in vitro evaluation of κ-carrageenan based polymeric hybrid nanocomposite scaffolds for bone tissue engineering’ by Muhammad Umar Aslam Khan et al., RSC Adv., 2020, 10, 40529–40542. DOI: 10.1039/D0RA07446B.The authors regret errors in Fig. 9 in the original article. The corrected Fig. 9 is shown below where all three +ive control panels and the 72 h CG-g-Aac-2 panel have been replaced.Open in a separate windowFig. 9Cell morphology of MC3T3-E1 against +ive control and all scaffold samples (CG-g-AAc1, CG-g-AAc2 and CG-g-AAc3) under standard in vitro conditions. The red arrows show thread-like morphology and the yellow arrows exhibits well-grown morphology of the cells.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers. 相似文献
43.
44.
Kadir Desdicioglu Mehmet Ali Malas Selen Bahceci Fatma Simsek Ayse Gizem Polat 《Journal of the Anatomical Society of India》2017,66(1):37-42
Introduction
In our study, the aim was to anatomically and histologically investigate the morphometric structures of the branches involved in the sural nerve and sural nerve formation.Method
The study was conducted on 46 lower extremities of 23 fetuses which were obtained from Izmir Katip Çelebi University, Atatürk Training and Research Hospital, with ages from 18 and 32 gestational weeks, without any external pathology or anomaly. During the study period, the posterior-side skin dissection of the lower extremity was performed with the aid of a surgical dissection microscope initially, and the structures forming the sural nerve and the sural nerve were exposed and made visible. Afterwards, sections were taken from these structures for morphometric measurements and histological examination.Results
The mean values and standard deviations of morphometric measurements obtained were determined. Separately, it was determined that there was no statistical difference between right-left sides and genders in morphometric measurements (p > 0.05). The sural nerve was determined to be differentiated into 4 types as A, B, C and D according to the way the nerve branches forming sural nerve join. In addition, differing characteristics pertaining to the sural nerve and branches were determined.Discussion
We are of the opinion that the data obtained in our study will be of use to neurologists, orthopedists and clinicians engaged in this region during interventional procedures. 相似文献45.
Ozdogan M Ersoy E Dundar K Albayrak L Devay S Gundogdu H 《The Journal of surgical research》2005,129(2):260-264
BACKGROUND: Underlying hepatic injury and cirrhosis are leading factors that interfere with the post-operative liver regeneration and function. Hyperbaric oxygenation (HBO) has been reported to ameliorate the ischemia-reperfusion injury of the liver, to induce compensatory hypertrophy of the predicted remnant liver in rats after portal vein ligation and to augment liver regeneration after hepatectomy in non-cirrhotic rats. Our aim was to determine the effect of HBO treatment on liver regeneration after partial hepatectomy in normal and cirrhotic mice in this experimental study. MATERIALS AND METHODS: The effect of HBO on liver regeneration was studied in a mice model combining carbon tetrachloride induced cirrhosis and partial hepatectomy. Mice were divided into four groups: Control, cirrhotic, non-cirrhotic HBO-treated, and cirrhotic HBO-treated. All animals underwent 40% hepatectomy. Liver regeneration was evaluated by the proliferating cell nuclear antigen-labeling index. Serum aspartate aminotransferase and alanine aminotransferase levels were measured to evaluate liver injury. RESULTS: Serum alanine aminotransferase and aspartate aminotransferase levels were significantly decreased in HBO-treated cirrhotic group compared to cirrhosis group after hepatectomy (P = 0.001 and P = 0.014, respectively). The proliferating cell nuclear antigen labeling index was significantly higher in HBO treated cirrhotic group than in cirrhotic group after hepatectomy (P = 0.022). CONCLUSIONS: Our results suggest that HBO treatment improves liver functions and augments hepatocyte regeneration in cirrhotic mice after hepatectomy. Post-operative HBO treatment may have a beneficial effect on post-operative liver function and regeneration in cirrhotic patients. 相似文献
46.
Marwan Abdulhakim Shaah Md Sohrab Hossain Faisal Allafi Mohd Omar Ab Kadir Mardiana Idayu Ahmad 《RSC advances》2022,12(16):9845
The present study was conducted to determine the feasibility of biodiesel production from candlenut oil using supercritical methanol (scMeOH) as a non-catalytic transesterification process. The influence of the scMeOH transesterification process was determined with varying pressure (85–145 bar), temperature (260–300 °C), methanol to oil (M : O) ratio (15 : 1–35 : 1), and reaction time (15–25 min). The experimental conditions of the scMeOH transesterification process were designed using central composite design (CCD) of experiments, and the process was optimized using response surface methodology (RSM). It was found that scMeOH temperature, pressure, M : O ratio, and reaction time substantially influenced the transesterification process. The maximum biodiesel yield of 96.35% was obtained at an optimized scMeOH transesterification process at the pressure of 115 bar, the temperature of 285 °C, M : O ratio of 30 : 1, and reaction time of 22 min. A second-order kinetics model and Eyring equations were utilized to determine the kinetics and thermodynamics of biodiesel production from candlenut oil. The activation energy value was determined to be 28.35 KJ mol−1. Analyses of the thermodynamic properties of biodiesel revealed that the transesterification process was non-spontaneous and endothermic. The physicochemical properties of produced candlenut biodiesel via scMeOH complied with most of the biodiesel properties as per ASTM D6751 and EN14214, thereby referring to good quality biodiesel production. The findings of the present study reveal that the scMeOH is an effective non-catalytic transesterification process for biodiesel production from candlenut oil.The present study was conducted to determine the feasibility of biodiesel production from candlenut oil using supercritical methanol (scMeOH) as a non-catalytic transesterification process. 相似文献
47.
Systemic inflammatory response syndrome in acute‐on‐chronic liver failure: Relevance of ‘golden window’: A prospective study 下载免费PDF全文
Ashok Choudhury Manoj Kumar Barjesh C Sharma Rakhi Maiwall Viniyendra Pamecha Richard Moreau Yogesh K Chawla Ajay Duseja Mamun Mahtab Salimur Rahman Saeed S Hamid Amna S Butt Wasim Jafri Seok Siam Tan Harshad Devarbhavi Deepak Amarapurkar Qin Ning C E Eapen Ashish Goel Dong J Kim Hasmik Ghazinyan Gamal Shiha Guan H Lee Zaigham Abbas Diana A Payawal A Kadir Dokmeci Man‐Fung Yuen Laurentius A Lesmana Ajit Sood Albert Chan George K Lau Ji Dong Jia Zhongping Duan Chen Yu Osamu Yokosuka Priyanka Jain Ajeet S Bhadoria Guresh Kumar Shiv K Sarin for the APASL ACLF working party 《Journal of gastroenterology and hepatology》2017,32(12):1989-1997
48.
49.
Excessive haemorrhage is one of the commonest symptom when women present to obstetricians and gynaecologists. In the majority of cases the cause is related to the primary obstetric and gynaecological pathology and is easily identified. However, less commonly, the bleeding is unexpected and due to an undiagnosed underlying coagulation defect, the commonest of which is von Willebrand (vWD) disease. Menorrhagia is a common, and may be the only, clinical manifestation of an inherited bleeding disorder. Screening 150 women with menorrhagia, vWD was diagnosed in 13% of patients and other hereditary haemorrhagic disorders in another 4%. Menorrhagia with onset at the menarche was predictive of an inherited bleeding disorder in 65% of vWD and 67% of FXI deficient patients. Therefore, testing for bleeding disorders should be considered in women with menorrhagia especially those with early onset and no obvious pelvic pathology. Childbirth and puerperium present a special risk for excessive haemorrhage. The risk of postpartum haemorrhage is very high in women with inherited bleeding disorders. In our centre, the incidence of primary and secondary postpartum haemorrhage was 22% and 11% in carriers of haemophilia 18.5% and 20% in vWD and 16% and 24% in FXI deficient women, respectively. Acquired haemophilia can be an unusual cause of severe and unexpected postpartum haemorrhage with a very high mortality rate. Unexplained postpartum and postoperative haemorrhage that does not respond to general measures should alert clinicians to the possibility of bleeding disorders as a causative factor. In addition, increased awareness among obstetricians and gynaecologists of these less common causes and close collaboration with the local haemophilia centre and availability of management guidelines are essential for optimal outcome. 相似文献
50.
Karagözler AA Mehmet N Batçioglu K 《Journal of toxicology and environmental health. Part A》2002,65(17):1237-1246
The aim of this study was to examine solvent-associated effects on blood cytokine levels, antioxidant enzyme activities, and malondialdehyde (MDA) concentration in house painters. Trace element (Cu and Zn) and nitrite and nitrate levels as well as protein concentrations in erythrocytes and serum were determined. Thirty male house painters and 30 male clerical workers were included in the study. There were 13 smokers and 17 nonsmokers in each group. Hemoglobin concentrations were significantly lower in house-painter blood compared to controls. House painters had significantly higher concentrations of erythrocyte protein (excluding hemoglobin), whereas no significant difference was observed between serum protein levels. Proinflammatory cytokine levels, such as tumor necrosis factor-alpha and interleukin-8, were significantly increased in house painters' sera. Interleukin-6 was below the detection limit of the assay in both groups. Interleukin-1beta and cytokine receptor interleukin 2R concentrations were not significantly affected. Furthermore, a three- to fourfold increase in nitrite and nitrate concentrations was found in house painters' sera. Serum superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities were significantly lower in house painters compared to controls. Malondialdehyde (MDA) concentration, a measure of lipid peroxidation, was found to be significantly elevated. In house painters, erythrocyte carbonic anhydrase and catalase activities were elevated approximately 11- fold and 2-fold, respectively. Zinc levels were significantly decreased in house painters' sera. Smoking was not found to be a major confounder for the association between solvent exposure and blood parameters. 相似文献