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排序方式: 共有137条查询结果,搜索用时 187 毫秒
41.
Removal of Ni(II) ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants 总被引:1,自引:1,他引:0
Amar D. Vibhandik Kumudini V. Marathe 《Frontiers of Chemical Science and Engineering》2014,8(1):79-86
Ni(II) ions were removed from aqueous waste using micellar enhanced ultrafiltration (MEUF) with a mixture of surfactants. The surfactant mixture was the nonionic surfactant Tween 80 (TW80) mixed with the anionic surfactant sodium dodecyl sulfate (SDS) in different molar ratios ranging from 0.1–1.5. The operational variables of the MEUF process such as pH, applied pressure, surfactant to metal ion ratio and nonionic to ionic surfactant molar ratio (α) were evaluated. Rejection of Ni and TW80 was 99% and 98% respectively whereas that for SDS was 65%. The flux and all resistances (fouling resistance, resistance due to concentration polarization) were measured and calculated for entire range of α respectively. A calculated flux was found to be declined with time, which was mainly attributed to concentration polarization rather than resistance from membrane fouling. 相似文献
42.
43.
Dr. Ganga B. Vamisetti Dr. Roman Meledin Dr. Pushparathinam Gopinath Prof. Ashraf Brik 《Chembiochem : a European journal of chemical biology》2019,20(2):282-286
Deubiquitinases are important components of the protein regulatory network and, hence, constitute a tempting drug target. We report herein structure–activity relationship studies to develop halogen-substituted isoquionoline-1,3-dione-based inhibitors of the deubiquitinase USP2. In contrast to our previous reports, the best compound discovered was found to act through a reactive oxygen species independent, uncompetitive mechanism with an IC50 of 250 nm . We show the crucial role of halogens in the common scaffold to provide potency and selectivity of our compound, where the introduction of the fluorine atom completely switches the selectivity of the inhibitor between USP2 and USP7. Our cellular studies highlight the potential applicability of the reported compound for in vivo experiments. The discovery of the isoquinoline-1,3-dione core and the knowledge obtained with regard to halogen substituents provide a platform towards understanding USP2 inhibition and the development of highly selective next-generation deubiquitinase inhibitors. 相似文献
44.
Chetna Jadala Manda Sathish Pratibha Anchi Ramya Tokala Uppu Jaya Lakshmi Velma Ganga Reddy Dr. Nagula Shankaraiah Dr. Chandraiah Godugu Dr. Ahmed Kamal 《ChemMedChem》2019,14(24):2052-2060
Molecular hybridization approach is a promising structural modification tool to design new chemical entities (NCEs) by mimicking two different pharmacophoric units into one scaffold to enhance the biological properties. With this aim, combretastatin-A4 acids were integrated with sulfonyl piperazine scaffolds as a one molecular platform and evaluated for their in vitro antiproliferative activity against a panel of human cancer lines cell lines namely, lung (A549), mouse melanoma (B16F10), breast (MDA MB-231and MCF-7) and colon (HCT-15) by MTT assay. Amongst which the compound (E)-3-(4-Chlorophenyl)-1-(4-((4-chlorophenyl)sulfonyl)piperazin-1-yl)-2-(3,4,5-trimethoxyphenyl)prop-2-en-1-one ( 5 ab ) displayed significant IC50 values in the range of 0.36 to 7.08 μm against the selected cancer cell lines. Moreover, 5 ab was found to be the most potent member of this series with IC50 0.36±0.02 μm . Further investigations revealed that the compound 5 ab displayed significant inhibition of tubulin assembly with IC50 5.24±0.06 μm and molecular docking studies also disclosed the binding of 5 ab effectively in CA4 binding space at the colchicine binding site. The flow cytometric analysis demonstrated that the compound 5 ab caused cell cycle arrest at G2/M phase in A549 cells. Compound 5 ab induced apoptosis in A549 cells which was further evaluated by different staining assays such as DAPI and AO which undoubtedly speculated, the induction of apoptosis. To study the anti-migration with 5 ab , cell migration/scratch wound assay was performed and the extent of apoptosis was studied by Annexin-V, including mitochondrial potential by JC-1 staining. 相似文献
45.
S Subramani A Sultan Nasar T Philip Gnanarajan N Padmanabha Iyer Ganga Radhakrishnan 《Polymer International》2000,49(6):546-550
Imidazole, 2‐methylimidazole and benzimidazole‐blocked aromatic and aliphatic diisocyanates have been prepared and polymerized with pyromellitic dianhydride in the presence of a basic catalyst. The polymers are characterized with FTIR, 1H NMR and 13C NMR spectroscopy and GPC, DSC and TGA. The structure–property relationship of blocked diisocyanates are discussed in terms of molecular weight of the polyimides obtained. Considering the blocking agent, GPC results show that the benzimidazole blocked adduct yields higher molecular weight polymer than the 2‐methylimidazole‐blocked adduct which, in turn, yields higher molecular weight polymer than the imidazole‐blocked adduct. Considering the structure of the isocyanate, the molecular weight of polymer increases from isophorone diisocyanate to hexamethylene diisocyanate and to toluene diisocyanate (TDI). DSC traces of the polymers derived from TDI show glass transitions (Tg) in the temperature range 152–180 °C and the values increase from the polymer based on imidazole‐blocked TDI to 2‐methylimidazole‐blocked TDI and to benzimidazole‐blocked TDI. © 2000 Society of Chemical Industry 相似文献
46.
在引入正交频分复用调制技术的水声通信中,发送端与接收端采样频率偏差及多普勒频移会引起子载波间的干扰,为了抑制信号产生幅度衰落和相位畸变并降低系统误码率,根据多载波水声通信的特点提出了一种抑制载波间干扰的方法.利用导频序列拟合出采样频偏,通过重采样滤波器进行补偿,对多普勒因子粗补后,利用各象限解调数据方差的极小值确定解调数据长度,通过高分辨率傅里叶变换实现多普勒干扰抑制.3次实验结果证明该方法有效可行,能够较好地抑制子载波干扰,可显著提高多载波水声通信的系统性能. 相似文献
47.
Moacir Godinho Filho Gilberto Miller Devós Ganga Angappa Gunasekaran 《国际生产研究杂志》2016,54(24):7523-7545
The main objective of this paper is to investigate the degree to which lean manufacturing (LM) practices are being implemented within Brazilian small and medium enterprises (SMEs), by defining what LM means, in the view of SMEs in Brazil. In addition, the paper investigates the relationship between LM implementation and performance of such companies. The research method used in this paper comprised of an exploratory survey using the partial least-square method with the structural equation modelling technique (PLS-SEM). The results show that the companies studied used practices in a fragmented manner, without a holistic view of LM, which is considered to be one of the most important parts of this approach. Only the constructs of statistical process control, total productive maintenance and employee involvement are being implemented as an integrated approach for Brazilian SMEs. These companies do not take other important constructs such as customer involvement, continuous flow, pull production, set-up time reduction, supplier development and supplier feedback into consideration as part of LM systems, despite using some practices in a dispersed manner. Concerning performance, the present study shows that even in a fragmented way, the implementation of these LM practices help these companies to achieve improvement in operational performance. 相似文献
48.
Surendra K. Gupta Ashish Sharma Binod Kumar Kanaujia Ganga Prasad Pandey 《Wireless Personal Communications》2014,77(1):395-410
A novel compact triple band slit cut circular patch antenna with superstrate is proposed; slits on the patch provide additional resonances. The superstrate (cover) of dielectric layer provides protection to printed circuit antenna from environmental hazards due to abnormal weather conditions. The slits add two resonances in the resonance of a circular patch to achieve triple band antenna for multi services. The dielectric superstrate or cover above the microstrip patch causes the change in fringing fields between the patch and ground plane. The change in fringing field is accounted to calculate the effective relative permittivity. The effective permittivity is considered to evaluate the changes in resonance frequency due to superstrate. The various parameters of the antenna have been investigated and the antenna is simulated on Ansoft’s HFSS software simulator. A prototype of antenna is fabricated to confirm the return loss by measurement using the Agilent Technologies’ N5230A PNA-L Network Analyzer. The proposed structure with superstrate possess triple band characteristics and provides protection from environmental hazards. The resonating frequencies of the bands are 7.3, 8.7 and 10.3 GHz. The analytical results are found in good agreement with the simulated results obtained by Ansoft’s HFSS and further confirmed by measurement. Antenna is worth for X band operations such as remote sensing, WPAN and military satellite communication and vehicular applications. 相似文献
49.
Latex blends of different compositions of poly(methyl methacrylate-co-n-butylacrylate) and gelatin have been synthesised in latex form with crosslinking agents. These latex blends were characterized by thermal and mechanical properties. The morphology of cross-linked latex blends were studied by scanning electron microscopy (SEM). 相似文献
50.
Ageing behaviour of polystyrene (PS)/ammonium perchlorate (AP) propellent leading to ballistic changes has been studied. It follows a zero-order kinetic law. Ageing behaviour leading to change in burning rate () in the temperature range of 60–200 ° C was found to remain the same. The dependence of the change of the average thermal decomposition (TD) rate at 230 and 260°C on the change in burning rate for the propellant aged at 100 ° C in air suggests that the slow TD of the propellant is the cause of ageing. The safe-life (for a pre-assigned burning-rate change limit) at 25 ° C in air has been calculated as a function of the rate of change. 相似文献