全文获取类型
收费全文 | 3821篇 |
免费 | 197篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 71篇 |
儿科学 | 116篇 |
妇产科学 | 143篇 |
基础医学 | 400篇 |
口腔科学 | 99篇 |
临床医学 | 257篇 |
内科学 | 830篇 |
皮肤病学 | 71篇 |
神经病学 | 178篇 |
特种医学 | 69篇 |
外科学 | 788篇 |
综合类 | 105篇 |
一般理论 | 2篇 |
预防医学 | 272篇 |
眼科学 | 104篇 |
药学 | 327篇 |
中国医学 | 21篇 |
肿瘤学 | 181篇 |
出版年
2023年 | 49篇 |
2022年 | 114篇 |
2021年 | 164篇 |
2020年 | 103篇 |
2019年 | 130篇 |
2018年 | 165篇 |
2017年 | 102篇 |
2016年 | 126篇 |
2015年 | 137篇 |
2014年 | 144篇 |
2013年 | 199篇 |
2012年 | 328篇 |
2011年 | 324篇 |
2010年 | 164篇 |
2009年 | 120篇 |
2008年 | 190篇 |
2007年 | 193篇 |
2006年 | 186篇 |
2005年 | 197篇 |
2004年 | 161篇 |
2003年 | 148篇 |
2002年 | 135篇 |
2001年 | 41篇 |
2000年 | 33篇 |
1999年 | 38篇 |
1998年 | 28篇 |
1997年 | 18篇 |
1996年 | 9篇 |
1995年 | 17篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 8篇 |
1984年 | 13篇 |
1983年 | 14篇 |
1982年 | 7篇 |
1981年 | 17篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1977年 | 8篇 |
1976年 | 10篇 |
1972年 | 6篇 |
1969年 | 5篇 |
1963年 | 4篇 |
排序方式: 共有4034条查询结果,搜索用时 0 毫秒
101.
Syed Sayeed Ahmad Mohammad Khalid Mohammad A. Kamal Kaiser Younis 《Current Neuropharmacology》2021,19(11):1884
Background Alzheimer''s disease (AD) affects several people worldwide and has devastating impacts on society with a limited number of approaches for its pharmacological treatment. The main causes of AD are not clear yet. However, the formation of senile plaques, neurofibrillary tangles, hyper-phosphorylation of tau protein, and disruption of redox homeostasis may cause AD. These causes have a positive correlation with oxidative stress, producing reactive ions, which are responsible for altering the physiological condition of the body.Conclusion Ongoing research recommended the use of phytochemicals as acetylcholinesterase inhibitors to hinder the onset and progression of AD. The natural compound structures, including lignans, flavonoids, tannins, polyphenols, triterpenes, sterols, and alkaloids have anti-inflammatory, antioxidant, and anti-amyloidogenic properties. The purpose of this article is to provide a brief introduction to AD along with the use of natural compounds as new therapeutic approaches for its management. 相似文献
102.
LaFeO3 nanospheres with an orthorhombic perovskite structure were synthesized by a sol–gel autocombustion method in the presence of different citric acid ratios (x = 2, 4, 8, and 16) and utilized for the photocatalytic conversion of o-aminophenol (OAP) to 2-aminophenoxazine-3-one (APX) for the first time. OAP is one of the most toxic phenolic derivatives used as a starting material in many industries; however, the dimerization product APX has diverse therapeutic properties. Photocatalytic conversion was carried out in ethanol/water and acetonitrile/water mixtures in the absence and presence of molecular oxygen at ambient temperature via the oxidative coupling reaction that mimics phenoxazinone synthase-like activity. The LaFeO3 samples showed a superior photocatalytic activity of OAP to APX with rate constants of 0.43 and 0.92 min−1 in the absence and presence of molecular oxygen, respectively. Thus, the LaFeO3 nanozymes could be used as promising candidates in industrial water treatment and phenoxazinone synthase-like activity.LaFeO3 nanospheres were synthesized by a facile sol–gel autocombustion method and explored for the photocatalytic transformation of o-aminophenol to 2-aminophenoxazine-3-one. 相似文献
103.
Mashael Saqer Al-Mutairi Ibtehal Kamal Matar Suad Alfadhli Awated Al-Mutairi 《Asian Pacific journal of cancer prevention》2021,22(12):4017
Background:Camel urine (CU) has been used as traditional treatment in the Arabian Peninsula for centuries. Although, researchers have reported CU anti-cancer effects, the exact mechanism(s) of action involved has not been fully elucidated. The epithelial–mesenchymal transition EMT is a phenotypic switch that promotes the acquisition of a fibroblastoid-like morphology by epithelial tumor cells, resulting in enhanced tumor cell motility and invasiveness. EMT has been shown to contribute to metastasis and chemoresistance of carcinomas. For that, in the present study, we have assessed the potential mechanism (s) by which CU exert its anti-cancer effects and its possible synergistic therapeutic effect with Doxorubicin (DOX) in breast cancer cells. Methods:Determination of anti-proliferative and apoptosis validation of CU was performed by 3-(4,5-Dimethylthiazol-2-yl)-2,5,-diphenyltetrazolium bromide (MTT), annexin-V-fluorescein isothiocyanate assays, and Western blot. EMT protein markers, migration and invasion of cells were determined by Western blot or immunofluorescent staining, Scratch assay, Transwell invasion assay, respectively. Results:CU applied a significant anti-cancer effect on breast cancer cells via induction of DNA damage and apoptosis in a concentration- and time-dependent manner. Also, CU remarkably reversed the EMT by downregulating N-cadherin and Vimentin expression and upregulating E-cadherin expression. As a result, the stemness, migration and invasion of breast cancer cells were also inhibited, which was likely mediated by NF-κB-Snail signalling pathway and its downstream inflammatory effectors. CU successfully enhanced DOX cytotoxicity by reversing EMT which possibly through inhibition of NF-κB-Snail signalling and subsequently inflammation. Thus, our study provides new mechanistic bases for the therapeutic application of CU that may improve the outcomes of anti-cancer chemotherapy.Key Words: Chemoresistance, camel urine, breast cancer, NF-κB, EMT 相似文献
104.
105.
Singanamalla Bhanudeep Mohandoss Vichithra Suthar Renu Ahuja Chirag Kamal Sahu Jitendra Kumar 《Indian journal of pediatrics》2020,87(6):466-467
Indian Journal of Pediatrics - 相似文献
106.
107.
108.
Abdullah Alamri Chao Wu Shamima Nasreen Huan Tran Omer Yassin Ryan Gentile Deepak Kamal Rampi Ramprasad Yang Cao Gregory Sotzing 《RSC advances》2022,12(15):9095
Polymer dielectrics with ultra-high charge–discharge rates are significant for advanced electrical and electronic systems. Despite the fact that polymers possess high breakdown strength, the low dielectric constant (k) of polymers gives rise to low energy densities. Incorporating metal into polyimides (PI) at the polyamic acid (PAA) precursor stage of the synthetic process is a cheap and versatile way to improve the dielectric constant of the hybrid system while maintaining a high breakdown strength. Here, we explore inclusion of different percentages of Sn as a coordinated complex in a polyimide matrix to achieve metal homogeneity within the dielectric film to boost dielectric constant. Sn–O bonds with high atomic polarizability are intended to enhance the ionic polarization without sacrificing bandgap, a measurable property of the material to assess intrinsic breakdown strength. Enhancements of k from ca. 3.7 to 5.7 were achieved in going from the pure PI film to films containing 10 mol% tin.Polyimide with high dielectric constant and breakdown strength is synthesized via tin complexation of the polyamide acid precursor. Sn–O bonds with high atomic polarizability are intended to enhance the ionic polarization without sacrificing bandgap. 相似文献
109.
Rui-Xin Zhang Arthur Yin Fan An-Nan Zhou Kamal D. Moudgil Zhong-Ze Ma David Yue-Wei Lee Harry H.S. Fong Brian M. Berman Lixing Lao 《Journal of ethnopharmacology》2009
Ethnopharmacological relevance
The herbal formula Huo Luo Xiao Ling Dan (HLXL) and its modifications have been used in traditional Chinese medicine for about one hundred years to alleviate pain and inflammation.Aim
To investigate the effects of HLXL on complete Freund's adjuvant (CFA)-induced multiple-joint arthritis in rats.Materials and methods
Male Lewis rats, 190–210 g, were immunized subcutaneously at the base of the tail with 200 μl of heat-killed Mycobacterium tuberculosis in mineral oil (5 mg/ml). HLXL (2.30 and 4.60 g/kg) or vehicle control (n = 8 per group) was administered orally (i.g.) once a day between days 16 and 25 post-CFA injection. The rats were observed for signs of arthritis with arthritic changes (erythema, edema, induration) being scored on a scale of 0–4 of increasing severity using a standard scoring system. The maximum arthritis score per rat was 16. A plethysmometer was used to measure edema volume in each paw. Adverse effects of HLXL were monitored by closely observing the animals for unusual behavioral changes. Levels of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) in local tissue were measured by enzyme-linked immunosorbent assay on day 25 post-CFA.Results
HLXL significantly decreased arthritis scores between days 23–25 in the 2.30 g/kg group and 21–25 in the 4.60 g/kg group (p < 0.05). It reduced paw edema on days 22 and 24 in the 2.30 g/kg group and on days 20, 22 and 24 in the 4.60 g/kg group compared to control (p < 0.05). Local tissue TNF-α and IL-1β levels on day 25 post-CFA injection were significantly (p < 0.05) lower in rats treated with HLXL than in control rats. No observable adverse effects were found.Conclusion
The data suggest that HLXL produces significant anti-arthritic effects that may be mediated by suppressing pro-inflammatory cytokines, and it appears to be safe. 相似文献110.
Samir B. Pancholy Alia Abdel Fattah Abdalla M. Kamal Massroor Ghods Jaekyeong Heo Abdulmassih S. Iskandrian 《Journal of nuclear cardiology》1995,2(2):110-116