排序方式: 共有186条查询结果,搜索用时 15 毫秒
181.
Dipanwita Maity Md. Masud Rahaman Mollick Dibyendu Mondal Biplab Bhowmick Swarup Kumar Neogi Aritra Banerjee Sanatan Chattopadhyay Sudipta Bandyopadhyay Dipankar Chattopadhyay 《Carbohydrate polymers》2013
Nickel nanoparticles synthesized from NiCl2·6H2O by hydrazine hydrate in mixed solvent of ethanol and water in the presence of hydroxypropylmethylcellulose (HPMC) as protective and stabilizing agents. The morphology and sizes of synthesized Ni nanoparticles were studied by field-emission-scanning-electron microscopy (FESEM). Structural properties of nanoparticles were examined by X-ray diffraction (XRD). The polymer stabilized Ni nanoparticles were characterized by Fourier-transform infrared (FTIR) spectroscopy. The magnetic measurement showed that the resultant Ni nanoparticles were ferromagnetic. Also, the saturation magnetization (MS), remanent magnetization (MR) and coercivity (MR) were observed to increase with decreasing temperature. The results of magnetic characterization showed that the magnetic properties of the HPMC stabilized Ni nanoparticles are quite different from those of the bared Ni nanoparticles. All the observed magnetic properties essentially reflected the very typical nanoparticle type nature. Consequently, the resulting Ni nanoparticles were found to be highly active and recyclable catalyst for Suzuki coupling reactions. 相似文献
182.
Shamim S. M. Das Sudipta Hossain Md. Arafat Madhav Boddapati Taraka Phani 《Plasmonics (Norwell, Mass.)》2021,16(5):1623-1631
Plasmonics - An investigation on graphene-based hexagonal microstrip patch antenna has been carried out in this article. The hexagonal-shaped radiators have been designed and modified by... 相似文献
183.
Paramita Karmakar Tuhin Ghosh Sharmistha Sinha Sudipta Saha Pinaki Mandal Pradyot K. Ghosal Bimalendu Ray 《Carbohydrate polymers》2009,78(3):416-421
Sulfated fucans, the complex polysaccharides from brown seaweeds, possess various biological activities. To understand the structure activity relationship of sulfated fucans, we have investigated the structural features of one such polymer from Padina tetrastromatica using standard methods of carbohydrate structural analysis. We report a novel structural motif for this polymer. The average structure of this macromolecule that has a molecular mass of 25 kDa differs from the previous models in three respects. First, the core region of this macromolecule is composed primarily of α-(1 → 2)- and α-(1 → 3)-linked fucopyranosyl residues. Sulfate groups, when present are located at position 4 and 2 of fucosyl residues. Secondly, fucose and xylose is attached to this polymer to form branch points, one for every two residues within the chain. Finally, this macromolecule contained smaller amount of sulfate (0.21 mol of sulfate per mol of deoxyhexose). 相似文献
184.
Rational design of a molecular sensing tool is an important topic in molecular recognition, signalling, and optoelectronics that has piqued the interest of chemists, biologists, and environmental scientists. Approximately 150 years have passed since the beginning of the fluorescent chemosensor sector. Due to the paramagnetic properties of Cr3+ and Al3+, it is tough to prepare a photoluminescence plug-in detector. Most dye-based Al3+ sensors must be utilized in organic or mixed solvents for robust hydration of Al3+ in water. The sophisticated molecular design of sensors, conversely, allows for the detection of these metal ions in aqueous medium. The design of chemosensors using various fluorophores and their mechanisms of action have been thoroughly discussed. A literature survey covering the design of chemosensors and their mechanisms of action have been thoroughly discussed covering the period 2010–2022 and that was carried out including innovative and exemplary activities from numerous groups throughout the world that have significantly contributed to this sector. The most important advantages of these probes are their aqueous solubility and quick response with outstanding selectivity and sensitivity for temporal distribution with high fidelity of metals in living cells. 相似文献
185.
Wei He Gerrik F. Verhees Nikhil Bhagwat Ye Yang Dhananjaya S. Kulkarni Zane Lombardo Sudipta Lahiri Pritha Roy Jiaming Zhuo Brian Dang Andriana Snyder Shashank Shastry Michael Moezpoor Lilly Alocozy Kathy Gyehyun Lee Daniel Painter Ishita Mukerji Neil Hunter 《Developmental cell》2021,56(14):2073-2088.e3
186.
Single-molecule photobleaching (smPB) technique is a powerful tool for characterizing molecular assemblies. It can provide a direct measure of the number of monomers constituting a given oligomeric particle and generate the oligomer size distribution in a specimen. A major current application of this technique is in understanding protein aggregation, which is linked to many incurable diseases. Quantitative measurement of the size distribution of an aggregating protein in a physiological solution remains a difficult task, since techniques such as dynamic light scattering or fluorescence correlation spectroscopy (FCS) can provide an average size, but cannot accurately resolve the underlying size distribution. Here we describe the smPB method as implemented on a home-built total internal reflection fluorescence microscope (TIRF). We first describe the construction of a TIRF microscope, and then demonstrate the power of smPB by characterizing a solution of Amylin (hIAPP) oligomers, a 37-residue peptide whose aggregation is associated with Type II diabetes. We compare our results with FCS data obtained from the same specimen, and discuss the advantages and disadvantages of the two techniques. 相似文献