全文获取类型
收费全文 | 4643篇 |
免费 | 166篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 253篇 |
妇产科学 | 289篇 |
基础医学 | 347篇 |
口腔科学 | 174篇 |
临床医学 | 347篇 |
内科学 | 906篇 |
皮肤病学 | 68篇 |
神经病学 | 315篇 |
特种医学 | 231篇 |
外科学 | 1143篇 |
综合类 | 64篇 |
一般理论 | 1篇 |
预防医学 | 100篇 |
眼科学 | 173篇 |
药学 | 148篇 |
中国医学 | 15篇 |
肿瘤学 | 163篇 |
出版年
2023年 | 29篇 |
2022年 | 41篇 |
2021年 | 88篇 |
2020年 | 70篇 |
2019年 | 65篇 |
2018年 | 117篇 |
2017年 | 85篇 |
2016年 | 133篇 |
2015年 | 152篇 |
2014年 | 187篇 |
2013年 | 224篇 |
2012年 | 322篇 |
2011年 | 289篇 |
2010年 | 185篇 |
2009年 | 152篇 |
2008年 | 297篇 |
2007年 | 397篇 |
2006年 | 353篇 |
2005年 | 364篇 |
2004年 | 329篇 |
2003年 | 285篇 |
2002年 | 232篇 |
2001年 | 98篇 |
2000年 | 70篇 |
1999年 | 57篇 |
1998年 | 40篇 |
1997年 | 33篇 |
1996年 | 26篇 |
1995年 | 21篇 |
1994年 | 19篇 |
1993年 | 8篇 |
1992年 | 21篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 5篇 |
1974年 | 3篇 |
1970年 | 2篇 |
1966年 | 2篇 |
1963年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有4853条查询结果,搜索用时 31 毫秒
81.
Suna Sabuncuoglu Ayse Eken Ahmet Aydin Hilal Ozgunes Hilmi Orhan 《Drug and chemical toxicology》2015,38(4):375-382
We explored the association between the activities of antioxidant enzymes and their metallic cofactors in rats treated with cisplatin. The antioxidant effects of aminoguanidine, and a combination of vitamins E and C were investigated. Plasma platin was significantly lower than liver and kidney. Cisplatin treatment caused significant increase in plasma Se-glutathione peroxidase activity. Activities of Se-glutathione peroxidase, glutathione S-transferase, catalase and Cu,Zn-superoxide dismutase have been found to be significantly decreased in liver and kidney compared to controls. Zn levels in these organs were diminished upon cisplatin treatment, while levels of Cu were unaffected. Interestingly, levels of iron, the cofactor of catalase, were found to be significantly increased in liver and kidney. Intervention with aminoguanidine or vitamins was generally prevented cisplatin-caused changes in the activity of enzymes and in the tissue levels of cofactor metals. These observations suggest that relation between activities of enzymes and levels of cofactor metals is multifactorial. 相似文献
82.
We report here a method for the synthesis of a unique hybrid gel system for the sustained delivery of P2X7 receptor (P2X7R) antagonist. P2X7R has been reported as a key mediator in inflammatory processes and controlled delivery of this molecule would be critical for the treatment of inflammatory arthritis. The hybrid gel designed here for the sustained delivery of P2X7R antagonists is based on crosslinked hydrophobic styrene-butadiene-styrene (SBS) polymer as a continuous network, where hydrogel particles prepared with hydrophilic poly(ethylene glycol) (PEG) were embedded into this system. PEG hydrogel particle-incorporated SBS gels were characterized through electron microscopy, water contact angle observations, and strong mechanical properties were confirmed through nanoindentation measurements. The release of P2X7R antagonist from these hybrid hydrogel-elastomer system demonstrated a sustained drug release profile up to 28 days at physiological pH, which was not observed in earlier reports. We obtained drug release percentages ranging from 49.72% to 93.04% which indicated the tunability of release through SBS crosslinking and hydrophilic/hydrophobic nature of SBS. This tunability is significant to achieve simultaneous improvements in drug efficacy with reduced side effects. CellTiter-Glo luminescence measurements using human kidney cells revealed that these networks are non-toxic and highly biocompatible with percent cell viabilities of higher than 85%. The approach presented here with crosslinked, amphiphilic and elastic SBS gel systems is not only promising for extended release of P2X7R antagonist but could also allow for incorporation of different molecules so that simultaneous/sequential and extended release profiles for therapeutic molecules could be achieved.We report here a method for the synthesis of a unique hybrid gel system for the sustained delivery of P2X7 receptor (P2X7R) antagonist. 相似文献
83.
Demir Arzu Meltem Aydin Fatma Acar Banu Kurt Tuba Poyraz Aylar Kiremitci Saba Gülleroglu Basak Azili Müjdem Nur Bayrakci Umut Selda 《Clinical rheumatology》2021,40(9):3817-3825
Clinical Rheumatology - Autoimmune pancreatitis (AIP) type 1 is an IgG4-related disease (IgG4-RD), characterized by inflammatory pseudotumors and histologically by dense lymphoplasmacytic... 相似文献
84.
Weidner Kathrin Behnes Michael Schupp Tobias Hoppner Jorge Ansari Uzair Mueller Julian Lindner Simon Borggrefe Martin Kim Seung-hyun Huseyinov Aydin Ellguth Dominik Akin Muharrem Meininghaus Dirk Große Bertsch Thomas Taton Gabriel Bollow Armin Reichelt Thomas Engelke Niko Reiser Linda Akin Ibrahim 《Journal of interventional cardiac electrophysiology》2022,63(1):13-20
Journal of Interventional Cardiac Electrophysiology - The study sought to assess the prognostic impact of chronic kidney disease (CKD) in patients with electrical storm (ES). ES represents a... 相似文献
85.
Acetyl salicylic acid improves somatosensory evoked potentials in streptozotocin-diabetic rats 总被引:4,自引:0,他引:4
Microalbuminuria and retinopathy was studied in a non-proteinuric diabetic population of Cameroon. Patients were enrolled on a consecutive basis in two referral hospitals in Yaoundé. Retinopathy was evaluated by direct ophthalmoscopy and biomicroscopy, and controlled by mydriatic fundus photography. Detection of microalbuminuria was carried out on an overnight urine sample using Micral II test (Boehringer Mannheim). Anthropometric and blood pressure measurements were done using validated methods. In 64 non-proteinuric diabetic patients (9 IDDM and 55 NIDDM) aged 19-70 years with known duration of diabetes of 1-23 years, the prevalence of retinopathy was 37.5%. Microalbuminuria was detected in 53.1% of patients. Microalbuminuria correlated with duration of diabetes, and blood pressure, retinopathy was positively correlated with age, and blood pressure. Retinopathy was not significantly associated with the known duration of diabetes. Retinopathy was found to be independently associated with microalbuminuria (P < 0.001) and microalbuminuria appeared to be a sensitive marker of retinopathy. The prevalence of retinopathy and microalbuminuria in this population was high. Microalbuminuria and non-proliferative retinopathy are independently associated, and are both associated with increased blood pressure levels in the study population. As shown in previous studies microalbuminuria may also be a sensitive marker of early diabetic retinopathy in African diabetic patients. 相似文献
86.
Adem Aydin Yavuz Selvi Lutfullah Besiroglu Murat Boysan Abdullah Atli Osman Ozdemir Sultan Kilic Ragıp Balaharoglu 《Journal of affective disorders》2013
It has been commonly recognized that circadian rhythm and sleep/wake cycle are causally involved in bipolar disorder. There has been a paucity of systematic research considering the relations between sleep and mood states in bipolar disorder. The current study examines the possible influences of sleep deprivation on mood states and endocrine functions among first-degree relatives of patients with bipolar disorder and healthy controls. Blood samples were taken at two time points in the consecutive mornings at predeprivation and postdeprivation periods. Participants simultaneously completed the Profiles of Mood States at two time points after giving blood samples. Plasma T3 and TSH levels increased after total sleep deprivation in both groups. Sleep deprivation induced TSH levels were reversely associated with depression–dejection among healthy controls. A paradoxical effect was detected for only the first-degree relatives of the patients that changes in plasma cortisol levels negatively linked to depression–dejection and anger–hostility scores after total sleep deprivation. Plasma DHEA levels became correlated with vigor-activity scores after sleep deprivation among first-degree relatives of bipolar patients. On the contrary, significant associations of depression–dejection, anger–hostility, and confusion–bewilderment with the baseline plasma DHEA levels became statistically trivial in the postdeprivation period. Findings suggested that first-degree relatives of patients with bipolar disorder had completely distinct characteristics with respect to sleep deprivation induced responses in terms of associations between endocrine functions and mood states as compared to individuals whose relatives had no psychiatric problems. Considering the relationships between endocrine functions and mood states among relatives of the patients, it appears like sleep deprivation changes the receptor sensitivity which probably plays a pivotal role on mood outcomes among the first-degree relatives of patients with bipolar disorder. 相似文献
87.
88.
Early osteoblastic activity on TiO2 thin films decorated with flower-like hierarchical Au structures
Spyridon Kalantzis Salih Veziroglu Theresa Kohlhaas Christian Flrke Yogendra Kumar Mishra Jrg Wiltfang Yahya Ail Franz Faupel Oral Cenk Aktas Aydin Gülses 《RSC advances》2020,10(48):28935
Titanium alloys are the most commonly used dental and orthopedic implant materials due to their proven biocompatibility and mechanical properties. The native oxide layer (TiO2 layer) formed on such Ti-based implants acts as the self-protecting layer against possible ion release. Increasing the oxide layer thickness further on such TiO2 implants even opens the triggering of the osseointegration process if the oxide layer is having a certain degree of roughness, preferably higher. This work reports a novel photocatalytic patterning of sputter deposited TiO2 layers with flower-like Au structures to enhance the early osteoblastic activity. The prepared hierarchical Au structures, composed of micro- and nanoscale features on the top, lead to improved number of filopodia formation. This suggest that proposed Au–TiO2 surface may foster the cell attachment and as well as cell proliferation.Flower-like hierarchical Au structures, composed of micro- and nanoscale features, lead to higher number of filopodia formation on TiO2 thin films. 相似文献
89.
Mehmet Cihan Cakir Hasan Kocer Yilmaz Durna Deniz Umut Yildirim Amir Ghobadi Hodjat Hajian Koray Aydin Hamza Kurt Necdet Saglam Ekmel Ozbay 《RSC advances》2020,10(50):29945
The phase change behavior of vanadium dioxide (VO2) has been widely explored in a variety of optical and photonic applications. Commonly, its optical parameters have been studied in two extreme regimes: hot (metallic) and cold (insulating) states. However, in the transition temperatures, VO2 acts like an inherent metamaterial with mixed metallic-insulating character. In this range, the portions of metallic and insulating inclusions are tuned by temperature, and therefore a gradual change of optical parameters can be achieved. In this paper, a universal hybrid modeling approach is developed to model VO2 in the intermediate region. For this aim, the measured reflectivity data, is analyzed and matched through the transfer matrix method (TMM) simulations where an effective medium theory (EMT) is employed. Based on the findings of this approach, not only the relative portions of inclusions are tailored but also their grain shapes are significantly altered in the transition range. Finally, the modeling approach is testified by experimental findings through dynamic device applications operating at short and mid infrared wavelengths. In addition, the hysteretic behaviors on electrical, optical, and structural parameters of the VO2 film along the heating and cooling cycles are demonstrated by the experiments and scrutinized by the simulations.A universal hybrid modeling approach is developed to model VO2 in transition, revealing dynamic behavior of metallic inclusions and grain shapes. 相似文献
90.
Mehmet Salih Aydin Aydemir Kocarslan Sezen Kocarslan Ahmet Kucuk ?rfan Eser Hatice Sezen Evren Buyukfirat Abdussemet Hazar 《Brazilian Journal Of Cardiovascular Surgery》2015,30(1):77-83