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Azidoethyl-2-bromo-2-methylpropanoate (AEBMP) has been synthesized from 2-azidoethanol and 2-bromo-2-methylpropionyl bromide under nitrogen atmosphere. The azido end-functional polystyrene (PS-N3) has been synthesized by Atom Transfer Radical Polymerization (ATRP) technique using AEBMP initiator and styrene in conjugation with Cu(1)Br-bipyridine catalyst at 100°C. The polymerization was performed at three different periods of time, and it was found that both yield and number average molecular weight were increased linearly with increasing reaction time. Thermogravimetric analysis showed that the polystyrene is stable up to 300°C. The molecular weight of the polystyrene was determined using Gel Permeation Chromatography (GPC), and structures of the initiator AEBMP and polystyrene (PS-N3) were characterized by 1H NMR and FT-IR spectroscopy.

2,4,5-trihydroxybutyrophenone (THBP) is a synthetic molecule possessing phenolic OH groups as well as non-phenolic CHx (x = 2 and 3) groups which are believed to be responsible for its antioxidant behavior. The antioxidant nature of THBP has been systematically investigated through quantum chemical calculation by density functional theory (DFT) method with B3LYP hybrid functional and 6-311G++(d,p) basis set in gas, water and methanol media. The principal pathways such as hydrogen atom transfer (HAT), sequential proton loss electron transfer (SPLET) and single electron transfer-proton transfer (SETPT) were considered for antioxidant reactions. Changes of enthalpy (ΔH) and free energy (ΔG) were computed for OH· radical scavenging by THBP. In addition, geometry, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), energy gap (Eg), the other descriptors (electron affinity (EA), ionization potential (IP), global hardness (η), softness (σ), electrophilicity (ω), chemical potential (μ), electronegativity (χ) etc.), Fukui function, molecular electrostatic potential (MEP) surface and spin density were also taken into account. The calculated data values were compared with those of gallic acid (GA), a well-recognized antioxidant, calculated at the same level and also with literature of those compounds claiming efficient antioxidant. The values of the calculated thermochemical parameters convey evidence in favor of THBP as an antiradical molecule which is strongly supported by the descriptor values. The free radical scavenging reaction may occur preferentially at 5-OH > 4-OH > α-CH2 positions of the molecule.

Early detection of breast cancer can be a life‐saving measure for many patients. The inaccessibility of X‐rays, magnetic resonance imaging (MRI), and other medical facilities in many resource‐constrained areas hinders the early detection of breast cancer. In this paper, the use of a rectangular patch antenna for breast cancer detection is proposed by using multiwall carbon nanotubes (MWCNTs) as patch material. The proposed antenna is designed by CST software which is (30 × 40 × 1.66) mm in dimension. A breast model is designed including tumor and cancerous tumors by specific tissue properties for observing the antenna performance in different cases. In free space, the return loss of the designed antenna is observed at −33.414 dB. Moreover, the S11 is examined in a normal breast, a breast including a normal tumor, and a breast including a cancerous tumor is −32.641 dB, −34.94 dB, and −35.22 dB respectively. It can be utilized on a human body phantom model due to its adaptability and reduced radiation properties. The proposed antenna is miniature in size, cost‐effective, easily portable, and eco‐friendly. It can be used as a first screening tool for breast cancer patients, particularly in resource‐constrained regions. [ABSTRACT FROM AUTHOR]

Mechanical properties and failure behaviors of friction stir spot welded (FSSW) joints of two dissimilar ferrous alloys, cold-rolled carbon steel (SPCC) and 409L stainless steel (SUS 409L), are investigated under opening-dominant combined loads. The texture of dissimilar FSSW joints depends on the upper sheet material. The failure contours for the FSSW joints under combined loads are constructed in terms of the axial load and shear load by modifying existing failure criteria for resistance spot welds. The shape of the failure contour also depends on the upper sheet material. The failure contours are nearly elliptic in shape when the upper sheet is SPCC and are relatively straight lines when the upper sheet is SUS 409L.

Serially correlation binomial data with random cluster sizes occur frequently in environmental and health studies. Such data series have traditionally been analyzed using binomial state-space or hidden Markov models without appropriately accounting for the randomness in the cluster sizes. To characterize correlation and extra-variation arising from the random cluster sizes properly, we introduce a joint Poisson state-space modelling approach to analysis of binomial series with random cluster sizes. This approach enables us to model the marginal counts and binomial proportions simultaneously. An optimal estimation of our model has been developed using the orthodox best linear unbiased predictors. This estimation method is computationally efficient and robust since it depends only on the first- and second- moment assumptions of unobserved random effects. Our proposed approach is illustrated with analysis of birth delivery data. [ABSTRACT FROM AUTHOR]

Osteoporotic fractures are known to be highly recurring. We investigate bone-dependent and bone-independent risk factors of osteoporotic fracture frequency and relative proportions at various body locations by using the data from the osteoporotic fracture study that was conducted by the National Health and Nutrition Examination Survey, 2007-2008. We propose a new zero-inflated baseline category multinomial mixed model to characterize the clustered count responses and multinomial proportions by subject simultaneously while taking account of zero inflation and randomness of cluster sizes. Our approach gives additional insights into the risk factors of osteoporotic fracture frequencies at various body locations. This joint modelling of fracture frequency also allows us to characterize relative proportion patterns at various body locations by subject between men and women across age. These findings have clear policy relevance to appropriate osteoporotic fracture prevention and resource allocation. [ABSTRACT FROM AUTHOR]

(t‐BuNSiMe2Flu)TiMe2 (1) activated with Me3Al‐free methylaluminoxane (dried MAO) which conducts vinyl addition polymerization of norbornene (N) with very high activity was applied for homopolymerization of N derivatives (i.e., 5‐vinyl‐2‐norbornene (5V2N), 5‐ethylidene‐2‐norbornene (5E2N), dicyclopentadiene (DCPD)) at 40 °C. The activities for the N derivatives were about two orders of magnitude lower than that for N and decreased in the following order: 5E2N ≫ 5V2N ≫ DCPD. Copolymerization of ethene (E) and 5E2N under an atmospheric pressure of E was then conducted by 1‐dried MAO. The copolymerization proceeded with better activity than the homopolymerization of 5E2N and gave poly(E‐co‐5E2N) with narrow molecular weight distribution. The content of the ethylidene group in poly(E‐co‐5E2N) was controlled by the feed ratio of 5E2N/E. The Tg value of the copolymer changed from 70 °C to 155 °C according to the 5E2N content from 27 mol % to 68 mol %. The addition of N as a third monomer to the E‐5E2N copolymerization improved the activity and raised the Tg values of the terpolymer above 200 °C. The content of 5E2N was controlled by the 5E2N/N ratio with keeping the high Tg values. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4581–4587, 2007 [ABSTRACT FROM AUTHOR]

Multilevel semicontinuous data occur frequently in medical, environmental, insurance and financial studies. Such data are often measured with covariates at different levels; however, these data have traditionally been modelled with covariate-independent random effects. Ignoring dependence of cluster-specific random effects and cluster-specific covariates in these traditional approaches may lead to ecological fallacy and result in misleading results. In this paper, we propose Tweedie compound Poisson model with covariate-dependent random effects to analyze multilevel semicontinuous data where covariates at different levels are incorporated at relevant levels. The estimation of our models has been developed based on the orthodox best linear unbiased predictor of random effect. Explicit expressions of random effects predictors facilitate computation and interpretation of our models. Our approach is illustrated through the analysis of the basic symptoms inventory study data where 409 adolescents from 269 families were observed at varying number of times from 1 to 17 times. The performance of the proposed methodology was also examined through the simulation studies.

The whole world is devastated by the impact of the COVID-19 pandemic. The socioeconomic and other effects of COVID-19 on people are visible in all echelons of society. The main goal of countries is to stop the spreading of this pandemic by reducing the COVID-19 related new cases and deaths. In this paper, we analyzed the correlated count outcomes, daily new cases, and fatalities, and assessed the impact of some covariates by adopting a generalized bivariate Poisson model. There are different effects of duration on new cases and deaths in different countries. Also, the regional variation found to be different, and population density has a significant impact on outcomes.