全文获取类型
收费全文 | 97篇 |
免费 | 6篇 |
国内免费 | 6篇 |
专业分类
化学 | 79篇 |
晶体学 | 2篇 |
力学 | 6篇 |
综合类 | 2篇 |
数学 | 3篇 |
物理学 | 17篇 |
出版年
2023年 | 2篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 2篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 31 毫秒
11.
Graphene field-effect transistors (GFET) have emerged as powerful detection platforms enabled by the advent of chemical vapor deposition (CVD) production of the unique atomically thin 2D material on a large scale. DNA aptamers, short target-specific oligonucleotides, are excellent sensor moieties for GFETs due to their strong affinity to graphene, relatively short chain-length, selectivity, and a high degree of analyte variability. However, the interaction between DNA and graphene is not fully understood, leading to questions about the structure of surface-bound DNA, including the morphology of DNA nanostructures and the nature of the electronic response seen from analyte binding. This review critically evaluates recent insights into the nature of the DNA graphene interaction and its affect on sensor viability for DNA, small molecules, and proteins with respect to previously established sensing methods. We first discuss the sorption of DNA to graphene to introduce the interactions and forces acting in DNA based GFET devices and how these forces can potentially affect the performance of increasingly popular DNA aptamers and even future DNA nanostructures as sensor substrates. Next, we discuss the novel use of GFETs to detect DNA and the underlying electronic phenomena that are typically used as benchmarks for characterizing the analyte response of these devices. Finally, we address the use of DNA aptamers to increase the selectivity of GFET sensors for small molecules and proteins and compare them with other, state of the art, detection methods. 相似文献
12.
13.
Caragisides A–C ( 1 – 3 , resp.), three new isoflavone glucosides, were isolated from the BuOH sub‐fraction of the EtOH extract of the whole plant of Caragana conferta, along with ononoside ( 4 ), reported for the first time from this species. The structures of the new compounds were elucidated by spectroscopic techniques including MS and 2D‐NMR spectroscopy. Compounds 1 – 3 showed significant inhibition of platelet aggregation. 相似文献
14.
Hsien-Ju Tien Long-Li Lai Yao-Kueng Lee Che-Ping Chuang Mou-Yung Yeh Tian-Shung Wu 《中国化学会会志》1988,35(3):237-240
A new method to prepare 3,3′-ethylenebissydnone (40%), 3,3′-tetramethylenebissydnone (37%) and 3,3′-hexamethylenebissydnone (43%) from the corresponding alkylene diamine with paraformaldehyde and potassium cyanide were investigated. Some new bissydone: ?3,3′-trimethylenebissydnone (6%), 3,3′-(4,4′-diphenyl)bissydnonylmethane (9%) and 3,3′-(4,4′-diphenyi)bissydnonyl ether (28%) were synthesized from the corresponding diamine, paraformaldehyde, sodium bisulfite and potassium cyanide. Biological test of 3,3′-(4,4′-diphenyl)bissydnonylmethane shows significant response for coronary dilgtion test, inhibition of collagen induced platelet aggregation and moderate carditropic response. 3,3′-(4,4′-Diphenyl)bissydnonyl ether also shows inhibition of collagen induced platelet aggregation and moderate carditropic response. 相似文献
15.
Dr. Nicolai Wagner Milena Schuhmacher Annett Lohmann Dr. André Nadler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(68):15483-15487
Photorelease of caged compounds is among the most powerful experimental approaches for studying cellular functions on fast timescales. However, its full potential has yet to be exploited, as the number of caged small molecules available for cell biological studies has been limited by synthetic challenges. Addressing this problem, a straightforward, one-step procedure for efficiently synthesizing caged compounds was developed. An in situ generated benzylic coumarin triflate reagent was used to specifically functionalize carboxylate and phosphate moieties in the presence of free hydroxy groups, generating various caged lipid metabolites, including a number of GPCR ligands. By combining the photo-caged ligands with the respective receptors, an easily implementable experimental platform for the optical control and analysis of GPCR-mediated signal transduction in living cells was developed. Ultimately, the described synthetic strategy allows rapid generation of photo-caged small molecules and thus greatly facilitates the analysis of their biological roles in live cell microscopy assays. 相似文献
16.
17.
Nurul Aida Ngah George J. Dias Darryl C. Tong Siti Noor Fazliah Mohd Noor Jithendra Ratnayake Paul R. Cooper Haizal Mohd Hussaini 《Molecules (Basel, Switzerland)》2021,26(23)
Background: Platelet-rich fibrin (PRF) has gained popularity in craniofacial surgery, as it provides an excellent reservoir of autologous growth factors (GFs) that are essential for bone regeneration. However, the low elastic modulus, short-term clinical application, poor storage potential and limitations in emergency therapy use restrict its more widespread clinical application. This study fabricates lyophilised PRF (Ly-PRF), evaluates its physical and biological properties, and explores its application for craniofacial tissue engineering purposes. Material and methods: A lyophilisation method was applied, and the outcome was evaluated and compared with traditionally prepared PRF. We investigated how lyophilisation affected PRF’s physical characteristics and biological properties by determining: (1) the physical and morphological architecture of Ly-PRF using SEM, and (2) the kinetic release of PDGF-AB using ELISA. Results: Ly-PRF exhibited a dense and homogeneous interconnected 3D fibrin network. Moreover, clusters of morphologically consistent cells of platelets and leukocytes were apparent within Ly-PRF, along with evidence of PDGF-AB release in accordance with previously reports. Conclusions: The protocol established in this study for Ly-PRF preparation demonstrated versatility, and provides a biomaterial with growth factor release for potential use as a craniofacial bioscaffold. 相似文献
18.
Jun Zhou Yong-zhi Qiu Xiao-peng Zang Chang-wang Pan Qiang Chen Jian Shen Si-cong Lin 《高分子科学》2005,23(1)
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
19.
There is a great challenge to overcome the limitation of tissue penetration depth, while maximizing the benefit of light‐triggered biochemical cascades in a well‐defined mode simultaneously. Here, a new method of near‐infrared (NIR) light‐triggered release of nitric oxide (NO) by developing upconversion nanoparticles (UCNPs)‐based conjugate chemistry is reported. As the key nanotransducer in the design, core–shell‐structured UCNPs are encapsulated with a layer of SiO2 and then covalently linked with a potent NO‐releasing donor (S‐nitroso‐N‐acetyl‐dl ‐penicillamine, SNAP). It is featured with highly localized breakage of chemical bonds of SNAP molecules by NIR–UV upconversion, enabling simultaneous NO release in a light dosage‐dependent manner. The biological effects of NO releasing are demonstrated by cellular imaging and inhibition of platelet aggregation from blood samples. This work provides a flexible and robust platform to generate cell‐signaling gas molecules trigged by NIR laser with deep tissue penetration. 相似文献
20.
通过葡萄糖、丙烯酸羟乙酯和丁二胺反应,制备了含不饱和双键的糖基功能单体。 采用傅里叶红外光谱和核磁共振氢谱对合成的产物进行结构表征确定。 采用紫外光引发接枝聚合技术,将制备的不饱和糖单体接枝聚合到聚氨酯膜的表面,以衰减全反射模式下傅里叶红外光谱对表面接枝反应进行了确认。 通过静态水接触角实验和血小板黏附实验,分别对改性聚氨酯膜表面的亲水性和血液相容性进行了研究,结果表明,改性聚氨酯膜表面的接触角从86°降低到45°,血小板的粘附量由14.36×103 cells/mm2减少到2.57×103 cells/mm2,亲水性明显增强,血液相容性显著改善。 相似文献