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51.
Physicochemical Characterization of Chrysin‐Derivative‐Loaded Nanostructured Lipid Carriers with Special Reference to Anticancer Activity
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Gourab Karmakar Prasant Nahak Priyam Chettri Biplab Roy Pritam Guha Koji Tsuchiya Kanjiro Torigoe Anoop Kumar Ranendu K. Nath Sukhen Bhowmik Utpal C. De Kaushik Nag Amiya K. Panda 《Journal of surfactants and detergents》2018,21(3):421-432
Homologues long‐chain chrysin derivatives (LCD, C n: 8–18) were synthesized and incorporated into nanostructured lipid carriers (NLC) with the aim to treat human neuroblastoma. Mutual miscibility and attractive interactions among the NLC components, namely tripalmitin (TP), cetyl palmitate (CP), oleic acid (OA), and the chrysin (CHR) derivatives (LCD) at the air–water interface were assessed by the Langmuir monolayer approach. Optimum combination for the NLC formulations was found to be 2:2:1 (M/M/M) for TP/CP/OA, respectively. NLC formulations, both in the absence and presence of LCD, were characterized by combined dynamic light scattering, electron microscopy, atomic force microscopy, and differential scanning calorimetry. The size and zeta potential of the NLC formulations were found in the range 200–350 nm and ?12 to ?18 mV, respectively. Encapsulation efficiency and release kinetics of CHR and LCD when loaded into NLC were also evaluated. LCD exhibited maximum incorporation, drug‐loading capacity, and sustained release because of its enhanced hydrophobicity. Superior incorporation efficiency and sustained‐release profile of LCD were able to enhance their anticancer activity against human neuroblastoma cell lines, compared to CHR, making them promising agents in combating cancer. 相似文献
52.
ABSTRACTResearch in UK and elsewhere has highlighted that older people are particularly vulnerable to negative health effects of overheating. This paper examines the magnitude, causes, preparedness and remedies for addressing the risk of summertime overheating in four case study residential care and extra-care settings across the UK, spanning different building types, construction and age. An interdisciplinary approach is adopted, drawing from building science and social science methods, including temperature monitoring, building surveys, and interviews with design and management teams. The findings suggest that overheating is a current and prevalent risk in the case study schemes, yet currently little awareness or preparedness exists to implement suitable and long-term adaptation strategies (e.g., external shading). There was a perception from designers to managers, that cold represents a bigger threat to older occupants’ health than excessive heat. A lack of effective heat management was found across the case studies that included unwanted heat gains from the heating system, confusion in terms of responsibilities to manage indoor temperatures, and conflicts between window opening and occupant safety. Given that care settings should provide protection against risks from cold and hot weather, design, management and care practices need to become better focused towards this goal. 相似文献
53.
Spontaneous polymerization to give conformal, uniform coatings on metals has been expanded to a series of different monomers. The monomer 4‐fluoro maleimide, when copolymerized with styrene, a coupling agent, and a bis‐maleimide crosslinker, imparts very low dielectric constant (2.4) to the coating while retaining high temperature resistance. Diethyl fumarate, with the same comonomers, enhances ductility and provides an adjustable glass transition temperature. Addition of glycidyl acrylate to the monomer system provides reactivity of the coating to epoxy resins. Kinetic studies using these monomers were consistent with the free radical polymerization mechanism. The rate of reaction seemed limited by the diffusion of species to the reaction site. Extent of incorporation of the new monomers into the chain backbone was verified, and adhesion and corrosion resistance properties examined. The data illustrate the versatility of the conformal, chrome free spontaneous polymerization process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 875–885, 2000 相似文献
54.
Lakshmi Muthusubramanian Rajat B. Mitra Suseela Rajkumar V. S. Sundara Rao 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1998,72(2):164-168
Synthesis of some (thiocyanomethyl)-thio heteroaromatic derivatives by reacting metal salts of (mercapto) heteraromatics with chloromethylthiocyanate using methanol or acetone as cosolvent, reported. All the synthesized derivatives were identified by conventional methods, IR-, 1H NMR and mass spectral data. All the prepared compounds were tested for their antifungal activity. © 1998 SCI 相似文献
55.
Samta Gajbhiye Sanjeev Karmakar Monisha Sharma Sanjay Sharma 《Information Security Journal: A Global Perspective》2018,27(1):42-56
Secure Simple Pairing, a Bluetooth-pairing protocol, suffers from passive off-line and active online-guessing attack. These assaults are a direct result of the shortcomings in Bluetooth specification. Bluetooth technology uses the principles of device inquiry and inquiry scan. Scanning devices listen in on known frequencies for devices that are actively inquiring. If two Bluetooth devices know absolutely nothing about each other, one must run an inquiry to try to discover the other. One device sends out the inquiry request, and any device listening for such a request will respond with its address, and possibly its name, Input/Output capability and other information. Before connection, each device knows the address, their name, their capability, Quality-of-Service, etc. During pairing, Man-In-The-Middle attacker may capture all the information of connecting devices and impersonate them. This paper introduces the security augmentation in Bluetooth pairing by postponing exchange of Input-Output capability and other information like Quality-of-Service until it is essentially required and by casing the link key with a pair of Elliptic Curve Diffie-Hellman keys. Consequently, this leads to increased pairing time. Yet, we overlooked the increased pairing time, as the proposed Bluetooth-pairing protocol improves security by strengthening the link key. 相似文献
56.
Mahesh Paidpilli Kapil Verma Rajat Pandey Anish Upadhyaya 《Transactions of the Indian Institute of Metals》2017,70(8):2017-2026
In the present work, one batch of prealloyed 6061Al powder was mixed with different lead compositions (5, 10, 15 vol.%) and another set with same composition was ball-milled for 5 h at 300 rpm. Microstructural features such as lattice constant, crystallite size, particle size and morphology were studied using XRD, particle size analyzer and SEM. Both the as-mixed as well as ball-milled powders were compacted at 300 MPa and sintered under N2 atmosphere for 1 h in tube furnace at 590 °C. The ball milling of 6061Al alloy powder improved sinter density and densification while lead addition showed negligible influence on these parameters. The microstructure of as-mixed 6061Al–Pb alloys exhibited equiaxial morphology whereas ball-milling resulted in elongated grains with uniform lead distribution. Quasi-static compressive mechanical behavior was investigated for 6061Al–Pb alloys at 1 × 10?3 s?1 strain rate. Results indicated that ultimate compressive and yield strength were sensitive to milling and lead volume fraction. 相似文献
57.
58.
Paul RK Badhulika S Niyogi S Haddon RC Boddu VM Costales-Nieves C Bozhilov KN Mulchandani A 《Carbon》2011,(12):3789-3795
Large-area mono- and bilayer graphene films were synthesized on Cu foil (∼1 in.2) in about 1 min by a simple ethanol-chemical vapor deposition (CVD) technique. Raman spectroscopy and high resolution transmission electron microscopy revealed the synthesized graphene films to have polycrystalline structures with 2–5 nm individual crystallite size which is a function of temperature up to 1000 °C. X-ray photoelectron spectroscopy investigations showed about 3 at.% carboxylic (COOH) functional groups were formed during growth. The field-effect transistor devices fabricated using polycrystalline graphene as conducting channel (Lc = 10 μm; Wc = 50 μm) demonstrated a p-type semiconducting behavior with high drive current and Dirac point at ∼35 V. This simple one-step method of growing large area polycrystalline graphene films with semiconductor properties and easily functionalizable groups should assist in the realization of potential of polycrystalline graphene for nanoelectronics, sensors and energy storage devices. 相似文献
59.
Abstract The kinetics of the forward and backward extraction of the title process have been investigated using a Lewis cell operated at 3 Hz and flux or (F) – method of data treatment. The dependences of (F) in the forward extraction on [Fe3+], [H2A2](o), pH, and [HSO4 ?] are 1, 0.5, 1, and ?1, respectively. The value of the forward extraction rate constant (k f ) has been estimated to be 10?7.37 kmol3/2 m?7/2 s?1. The analysis of the experimentally found flux equation gives the following simple equation: F f =100.13 [FeHSO4 2+] [A?], on considering the monomeric model of BTMPPA and the stability constants of Fe(III)‐HSO4 ? complexes. This indicates the following elementary reaction occurring in the aqueous film of the interface as rate determining: [FeHSO4]2++A?→[FeHSO4.A]+. The very high activation energy of 91 kJ mol?1 supports this chemical reaction step as rate-determining. The negative value of the entropy change of activation (?94 J mol?1 K?1) indicates that the slow chemical reaction step occurs via the SN2 mechanism. The backward extraction rate can be expressed by the equation: F b =10?5.13 [[FeHSO4A2]](o) [H+] [H2A2](o) ?0.5. An analysis of this equation leads to the following chemical reaction step as rate-determining: [FeHSO4A2](int)→[FeHSO4A]+A(i) ?. However, the activation energy of 24 kJ mol?1 suggests that the backward extraction process is intermediate controlled with greater contribution of the diffusion of one or the other species as a slow process. The equilibrium constant obtained from the rate study matches well with that obtained from the equilibrium study. 相似文献
60.
Anish Karmakar S. Sivaprasad S. Kundu Debalay Chakrabarti 《Metallurgical and Materials Transactions A》2014,45(4):1659-1664
Ferrite-carbide and ferrite-martensite dual-phase microstructures have been produced in a low-carbon steel with different ferrite grain structures such as, uniform distribution of coarse- and very fine-ferrite grains, and bimodal distribution of ferrite grain sizes comprising of coarse grains (~12 μm) and very fine grains (<2 μm). Very fine-grained dual-phase structure offered the best combination of tensile-strength and ductility among all the samples. The above microstructures have been compared in terms of their strain-hardening rate and the mechanism of plastic deformation. 相似文献