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https://www.readbyqxmd.com/read/28327536/consecutive-one-pot-versus-domino-multicomponent-approaches-to-3-diarylmethylene-oxindoles
#1
Sunhwa Park, Jiyun Lee, Kye Jung Shin, Euichaul Oh, Jae Hong Seo
Based on consecutive one-pot conditions combining three palladium-catalyzed reactions (Sonogashira, Heck and Suzuki-Miyaura reactions), a more efficient domino multicomponent method has been successfully developed to access a wide variety of 3-(diarylmethylene)oxindoles. Microwave irradiation and use of a silver salt were the most important factors to achieve high yields and stereoselectivity.
March 22, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28327524/reducing-risk-of-salmonellosis-through-egg-decontamination-processes
#2
REVIEW
Thilini Piushani Keerthirathne, Kirstin Ross, Howard Fallowfield, Harriet Whiley
Eggs have a high nutritional value and are an important ingredient in many food products. Worldwide foodborne illnesses, such as salmonellosis linked to the consumption of eggs and raw egg products, are a major public health concern. This review focuses on previous studies that have investigated the procedures for the production of microbiologically safe eggs. Studies exploring pasteurization and decontamination methods were investigated. Gamma irradiation, freeze drying, hot air, hot water, infra-red, atmospheric steam, microwave heating and radiofrequency heating are all different decontamination methods currently considered for the production of microbiologically safe eggs...
March 22, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28325036/microwave-hydrothermal-synthesis-of-terbium-ions-complexed-with-porous-graphene-for-effective-absorbent-for-organic-dye
#3
Keqin Chen, Hui Gao, Bowei Bai, Wenjing Liu, Xiaolong Li
A luminescent terbium ions/reduced graphene oxide complex (Tb-RGO) was successfully and rapidly synthesized by the microwave hydrothermal reaction via the interactions between terbium ions and the active oxygen functional groups of graphene oxide. The as-prepared material was porous stacked by multilayer graphene in all directions. Thus, the resulting product owed the high specific surface area, high adsorption capacity and ultra-fast adsorption rate. Combined with the characteristic photoluminescence derived from terbium ions, the material has potential applications in biosensing and environmental protection...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28325016/sleep-stage-classification-by-non-contact-vital-signs-indices-using-doppler-radar-sensors
#4
Masayuki Kagawa, Kazuki Suzumura, Takemi Matsui
Disturbed sleep has become more common in recent years. To improve the quality of sleep, undergoing sleep observation has gained interest as a means to resolve possible problems. In this paper, we evaluate a non-restrictive and non-contact method for classifying real-time sleep stages and report on its potential applications. The proposed system measures heart rate (HR), heart rate variability (HRV), body movements, and respiratory signals of a sleeping person using two 24-GHz microwave radars placed beneath the mattress...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324928/design-of-a-dual-slot-antenna-for-small-animal-microwave-ablation-studies
#5
Tyler J Moon, Christopher L Brace
This study presents the development of a dual-slot antenna for small animal tumor ablation. By using a dual-slot design at 8 GHz, it was hypothesized that smaller and more spherical ablations can be produced. After computer-aided design optimization, antennas were fabricated and ablations performed at 5-20 W for 15-120 s with the objective of creating ablations with a diameter/length aspect ratio of at least 0.9. The new dual-slot design at 8 GHz created significantly more spherical ablations than a commercial antenna at 2...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324722/incorporation-of-dielectric-constituents-to-construct-ternary-heterojunction-structures-for-high-efficiency-electromagnetic-response
#6
Bin Quan, Guoyue Xu, Daoran Li, Wei Liu, Guangbin Ji, Youwei Du
To satisfy the diverse requirements of low reflection and high absorption of microwave attenuation, the construction of multiple heterojunction structure is imperative. On the one hand, the impedance mismatching could be ameliorated via the addition of new component; on the other hand, the multiple interface polarizations derived from the architecture of heterojunction make for the dissipation of microwave. In this work, the ternary TiO2/RGO/Fe2O3 composites exhibit tremendous superiority compared with single TiO2 or RGO no matter the absorption coefficient or effective bandwidth...
March 14, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28322338/flexible-frequency-selective-metamaterials-for-microwave-applications
#7
Bo Gao, Matthew M F Yuen, Terry Tao Ye
Metamaterials have attracted more and more research attentions recently. Metamaterials for electromagnetic applications consist of sub-wavelength structures designed to exhibit particular responses to an incident EM (electromagnetic) wave. Traditional EM (electromagnetic) metamaterial is constructed from thick and rigid structures, with the form-factor suitable for applications only in higher frequencies (above GHz) in microwave band. In this paper, we developed a thin and flexible metamaterial structure with small-scale unit cell that gives EM metamaterials far greater flexibility in numerous applications...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28322155/microwave-induced-bismuth-salts-mediated-synthesis-of-molecules-of-medicinal-interests
#8
Debasish Bandyopadhyay, Ashlee Chavez, Bimal K Banik
Bismuth salts-mediated reactions are developed for the synthesis of diverse organic molecules of medicinal significance. Reactions conducted with bismuth salts are environmentally benign, economical, rapid and high yielding. Microwave irradiation has accelerated these reactions significantly. It is believed that bismuth salts released corresponding acids in the media during the reaction. However, a coordination of bismuth salt to the electronegative atom is also observed in NMR study. Bismuth has much less control (less attractive forces) over anions (for example, halides, nitrate, sulfate and triflates) compared to alkali metals...
March 20, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28319800/inhibition-of-salmonella-typhimurium-on-radish-sprouts-using-nitrogen-cold-plasma
#9
Yeong Ji Oh, A Young Song, Sea C Min
This study investigated the effects of cold plasma treatment (CPT) on the inhibition of Salmonella typhimurium on radish sprouts and the quality attributes of the sprouts. Radish sprouts were treated with nitrogen (N2)-cold plasma at 900W and 667Pa for 0, 2, 5, 10, and 20min using a microwave-powered CPT system. The sensory attributes of the radish sprouts, appearance and odor, were evaluated before and after the treatment. The effects of N2-CPT for 10min on microbial growth and the quality attributes of the radish sprouts were evaluated during storage for 12days at 4 and 10°C...
March 10, 2017: International Journal of Food Microbiology
https://www.readbyqxmd.com/read/28319652/effect-of-freezing-rate-and-microwave-thawing-on-texture-and-microstructural-properties-of-potato-solanum-tuberosum
#10
David M Phinney, John C Frelka, Anita Wickramasinghe, Dennis R Heldman
Food freezing is a preservation process that works by lowering temperature while simultaneously decreasing water activity. It is accepted that although freezing preserves foods, it generally has a negative effect on textural quality. This research investigated the texture response of potatoes (Solanum tuberosum) as a function of time to freeze (defined as the time for the center temperature to reach -20 °C) and thawing process. Potatoes slices (6 mm) were blanched then frozen in an ethanol/carbon dioxide bath, a pilot scale high velocity air freezer (HVAF) and a still air freezer to achieve various times to freeze...
March 20, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28319345/percutaneous-microwave-ablation-of-exophytic-tumors-in-hepatocellular-carcinoma-patients-safe-or-not
#11
Jianmin Ding, Yan Zhou, Yandong Wang, Xiang Jing, Fengmei Wang, Yijun Wang
BACKGROUND & AIMS: To explore the long-term outcomes and safety of ultrasound-guided percutaneous microwave ablation (MWA) of exophytic tumors in hepatocellular carcinoma (HCC) patients. METHODS: One hundred and thirty-two patients with subcapsular HCC were enrolled in this retrospective study. These patients were divided into the exophytic group (n=71) and non-exophytic group (n=61) according to the location of the tumor(s). A special technology of puncture and ablation was performed to treat the exophytic tumors...
March 20, 2017: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/28319303/synthesis-of-indoles-and-pyrroles-utilizing-iridium-carbenes-generated-from-sulfoxonium-ylides
#12
Janakiram Vaitla, Annette Bayer, Kathrin H Hopmann
Metal carbenes can undergo a myriad of synthetic transformations. Sulfur ylides are potential safe precursors of metal carbenes. Herein, we report cascade reactions that involve carbenoids derived from sulfoxonium ylides for the efficient and regioselective synthesis of indoles and pyrroles. The tandem action of iridium and Brønsted acid catalysts enables rapid assembly of the heterocycles from unmodified anilines or readily accessible enamines under microwave irradiation. The key mechanistic steps are the catalytic transformation of the sulfoxonium ylide into an iridium-carbene complex, followed by N-H or C-H functionalization of an aniline or enamine, respectively, and a final acid-catalyzed cyclization...
March 20, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28317985/hierarchical-porous-ni-boehmite-nickel-aluminum-oxide-flakes-with-enhanced-microwave-absorption-ability
#13
Biao Zhao, Junwei Liu, Xiaoqin Guo, Wanyu Zhao, Luyang Liang, Chao Ma, Rui Zhang
In this article, composites consisting of porous Ni cores coated with boehmite/nickel aluminum oxide nanoflakes were successfully prepared by a versatile method. The crystal constituents and shapes of the boehmite/nickel aluminum oxide nanoflakes were strongly influenced by reaction temperature, and their microwave absorption properties were investigated in terms of complex permittivity and permeability. The results reveal that the composites comprising porous Ni cores coated with boehmite/nickel aluminum oxide synthesized at 180 °C present superior absorption properties...
March 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28317908/determination-of-low-loss-in-isotopically-pure-single-crystal-28-si-at-low-temperatures-and-single-microwave-photon-energy
#14
Nikita Kostylev, Maxim Goryachev, Andrey D Bulanov, Vladimir A Gavva, Michael E Tobar
The low dielectric losses of an isotopically pure single crystal (28)Si sample were determined at a temperature of 20 mK and at powers equivalent to that of a single photon. Whispering Gallery Mode (WGM) analysis revealed large Quality Factors of order 2 × 10(6) (dielectric loss ~5 × 10(-7)) at high powers, degrading to 7 × 10(-5) (dielectric loss ~1.4 × 10(-6) at single photon energy. A very low-loss narrow line width paramagnetic spin flip transition was detected with extreme sensitivity in (28)Si, with very small concentration below 10(10) cm(-3) (less than 10 parts per trillion) and g-factor of 1...
March 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28317796/quantum-statistics-for-a-two-mode-magnon-system-with-microwave-pumping-application-to-coupled-ferromagnetic-nanowires
#15
Zahra Haghshenasfard, Michael G Cottam
A microscopic (Hamiltonian-based) method for the quantum statistics of bosonic excitations in a two-mode magnon system is developed. Both the exchange and the dipole-dipole interactions, as well as the Zeeman term for an external applied field, are included in the spin Hamiltonian, and the model also contains the nonlinear effects due to parallel pumping and four-magnon interactions. The quantization of spin operators is achieved through the Holstein-Primakoff formalism, and then a coherent magnon state representation is used to study the occupation magnon number and the quantum statistical behaviour of the system...
March 20, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28317710/influence-of-microwave-vacuum-drying-on-glass-transition-temperature-gelatinization-temperature-physical-and-chemical-qualities-of-lotus-seeds
#16
Yingting Zhao, Yajun Jiang, Baodong Zheng, Weijing Zhuang, Yafeng Zheng, Yuting Tian
This study investigated the effects of microwave power density on effective moisture diffusion coefficient (Deff), glass transition temperature (Tg), gelatinization temperature (TP), physical and chemical qualities of lotus seeds during microwave vacuum drying. Deff increased by 42% and 127% at 15W/g and 20W/g, respectively, when compared with 10W/g. TP was negatively correlated with the relaxation times of T21 and T22, while Tg was negatively correlated with the relative areas A22. The rates of change of color were observed to be divided roughly into two periods, consisting of a rapid change caused by enzymatic browning and a slow change caused by non-enzymatic browning...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28317379/optical-emission-from-c2-anions-in-microwave-activated-ch4-h2-plasmas-for-chemical-vapour-deposition-of-diamond
#17
Edward Mahoney, Benjamin S Truscott, Michael N R Ashfold, Yuri A Mankelevich
Visible emission from C2-(B2Σu+) anions has been identified underlying the much stronger Swan band emission from neutral C2(d3Πg) radicals (henceforth C2-* and C2*, respectively) in MW-activated C/H/(Ar) plasmas operating under conditions appropriate for the chemical vapour deposition (CVD) of diamond. Spatially resolved measurements of the C2-* and C2* emissions as functions of the C/H/(Ar) ratio in the input gas mixture, the total pressure, and the applied MW power, together with complementary 2-D(r, z) plasma modelling, identifies dissociative electron attachment (DEA) to C2H radicals in the hot plasma as the dominant source of the observed C2-* emission...
March 20, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28316594/power-and-time-dependent-microwave-assisted-fabrication-of-silver-nanoparticles-decorated-cotton-sndc-fibers-for-bacterial-decontamination
#18
Abhishek K Bhardwaj, Abhishek Shukla, Rohit K Mishra, S C Singh, Vani Mishra, K N Uttam, Mohan P Singh, Shivesh Sharma, R Gopal
Plasmonic nanoparticles (NPs) such as silver and gold have fascinating optical properties due to their enhanced optical sensitivity at a wavelength corresponding to their surface plasmon resonance (SPR) absorption. Present work deals with the fabrication of silver nanoparticles decorated cotton (SNDC) fibers as a cheap and efficient point of contact disinfectant. SNDC fibers were fabricated by a simple microwave assisted route. The microwave power and irradiation time were controlled to optimize size and density of silver nanoparticles (SNPs) on textile fibers...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28316339/uv-mediated-thiol-ene-click-reactions-for-the-synthesis-of-drug-loadable-and-degradable-gels-based-on-copoly-2-oxazoline-s
#19
Klaus P Luef, Charlotte Petit, Bettina Ottersböck, Gernot Oreski, Francis Ehrenfeld, Bruno Grassl, Stéphanie Reynaud, Frank Wiesbrock
An 80-membered library of gels composed of monofunctional 2-ethyl-2-oxazoline and 2-nonyl-2-oxazoline and one of four selected difunctional 2-oxazolines (containing either ether or ester bonds) were synthesized by microwave-assisted ring-opening polymerizations. The difunctional 2-oxazolines were prepared from the thiol-ene reaction of glycol dimercaptoacetate or 2,2'-(ethylenedioxy)diethanethiol and 2-but-3'-enyl-2-oxazoline or 2-dec-9'-enyl-2-oxazoline. 53 of the gels exhibited glass-transition temperatures, which ranged from -5...
April 2017: European Polymer Journal
https://www.readbyqxmd.com/read/28316244/electronic-properties-of-bimetallic-metal-organic-frameworks-mofs-tailoring-density-of-electronic-states-through-mof-modularity
#20
Ekaterina A Dolgopolova, Amy J Brandt, Otega Ejegbavwo, Audrey S Duke, Thathsara D Maddumapatabandi, Randima P Galhenage, Bryon W Larson, Obadiah Reid, Salai Cheettu Ammal, Andreas Heyden, Mvs Chandrashekhar, Vitalie Stavila, Donna A Chen, Natalia B Shustova
Development of porous well-defined hybrid materials (e.g., metal-organic frameworks (MOFs)) will add a new dimension to a wide number of applications ranging from supercapacitors and electrodes to "smart" membranes and thermoelectrics. From this perspective, understanding and tailoring electronic properties of MOFs is a key fundamental challenge that could unlock the full potential of these materials. In this work, we focused on the fundamental insights responsible for the electronic properties of three distinct classes of bimetallic systems, Mx-yM'y-MOFs, MxM'y-MOFs, and Mx(ligand-M'y)-MOFs, in which the second metal (M') incorporation occurs through: (i) metal (M) replacement in the framework nodes (type I), (ii) metal node extension (type II), and (iii) metal coordination to the organic ligand (type III), respectively...
March 18, 2017: Journal of the American Chemical Society
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