Powder synthesis and electrical,dielectric spectroscopic characterization of rare earth disilicates (D-Er2Si2O7): Transistor scaling-22 nm or beyond

Rare earth disilicates are now a day's being analyzed as a dielectric layer for transistor scaling for the advanced 22 nm regime or beyond. So to explore these materials, the polymorphic powdered Er₂Si₂O₇ (D phase) is synthesized by solid state double sintering method to study its characteristics. Structural characterization has been performed by X-ray diffraction. SEM and EDX results shows the rods like morphology of particles and composition. The dc electrical properties are evaluated by two probe method as a function of temperature. The dielectric spectroscopic measurements of D-Er₂Si₂O₇ are performed in the temperature range 300–420 K and frequency range 1 kHz to 1 MHz. The dc electrical transport phenomenon is analyzed using Mott’s variable-range hopping approach. The ac conductivity σ_ac(ω) is obtained through the dielectric spectroscopic measurements.     

Heat Transfer and Entropy in a Vertical Porous Plate Subjected to Suction Velocity and MHD

This article presents an investigation of heat transfer in a porous medium adjacent to a vertical plate. The porous medium is subjected to a magnetohydrodynamic effect and suction velocity. The governing equations are nondepersonalized and converted into ordinary differential equations. The resulting equations are solved with the help of the finite difference method. The impact of various parameters, such as the Prandtl number, Grashof number, permeability parameter, radiation parameter, Eckert number, viscous dissipation parameter, and magnetic parameter, on fluid flow characteristics inside the porous medium is discussed. Entropy generation in the medium is analyzed with respect to various parameters, including the Brinkman number and Reynolds number. It is noted that the velocity profile decreases in magnitude with respect to the Prandtl number, but increases with the radiation parameter. The Eckert number has a marginal effect on the velocity profile. An increased radiation effect leads to a reduced thermal gradient at the hot surface.     

Strategies towards the Synthesis of 6‐N,N‐Diethylcarbamyloxy‐1,4‐dimethoxy‐ 7‐naphthylboronic Acid

After acetylation, condensation between Danishefsky's diene and benzoquinone afforded a stable methoxytriacetoxydihydronaphthalene intermediate, which was subsequently transformed by the Snieckus DOM protocol into the regiospecific 7‐naphthylboronic acid.     

Synthetic strategies toward the synthesis of enoxacin-, levofloxacin-, and gatifloxacin-based compounds: A review

Enoxacin, levofloxacin, and gatifloxacin represent one of the most important prerogative scaffolds in drug development. They possess broad spectrum antimicrobial and anti-inflammatory activities. They inhibit bacterial growth by blocking their topoisomerase enzyme which is necessary for the proper functioning of bacterial DNA. In this article, we have reviewed the synthetic approaches involved in the synthesis of derivatives of enoxacin, levofloxacin, and gatifloxacin.     

Cytotoxic constituents of Abutilon indicum leaves against U87MG human glioblastoma cells

The study was aimed to identify cytotoxic leads from Abutilon indicum leaves for treating glioblastoma. The petroleum ether extract, methanol extract (AIM), chloroform and ethyl acetate sub-fractions (AIM-C and AIM-E, respectively) prepared from AIM were tested for cytotoxicity on U87MG human glioblastoma cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. These extracts exhibited considerable activity (IC₅₀ values of 42.6–64.5 μg/mL). The most active AIM-C fraction was repeatedly chromatographed to yield four known compounds, methyl trans-p-coumarate (1), methyl caffeate (2), syringic acid (3) and pinellic acid (4). Cell viability assay of 1–4 against U87MG cells indicated 2 as most active (IC₅₀ value of 8.2 μg/mL), whereas the other three compounds were much less active. Interestingly, compounds 1–4 were non-toxic towards normal human cells (HEK-293). The content of 2 in AIM-C was estimated as 3% by HPLC. Hence, presence of some more active substances besides methyl caffeate (2) in AIM-C is anticipated.     

Central simple superalgebras with anti-automorphisms of order two of the first kind

By a theorem of Albert's, a central simple associative algebra has an involution of the first kind if and only if it is of order 2 in the Brauer group. Our main purpose is to develop the theory of existence of anti-automorphisms of order 2 of the first kind on finite dimensional central simple associative superalgebras over K, where K is a field of arbitrary characteristic. First we need to generalize the Skolem–Noether Theorem to the superalgebra case. Then we show which kind of finite dimensional central simple superalgebras have an anti-automorphism of order 2 of the first kind.     

Depth dependent study of radon, thoron and their progeny in tube-wells

Radon has been recognized to be one of the major contributors to the natural radiation causing even lung cancer if it is present at enhanced levels. Its monitoring at highly confined locations such as underground caves, mines and tube-wells is very essential for finding the health related hazards among the workers. This paper reports the investigations of the levels of radon, thoron and their progeny monitored in the tube-wells of the Halls of residence at A.M.U., Aligarh, which lies in the subtropical region of Indo-Gangetic plains situated in North India. The twin cup dosimeters were fixed for exposure at a depth of 5?C35?feet with a difference of 5?feet from the ground surface. The values of radon and thoron concentrations were found to vary from 6.58 to 1218.57 and 7.41?C3226.61?Bq?m^?3, respectively. The preliminary results of this study for ??bare mode?? detectors have been separately published and compared with the recent data.     

[89Zr]-Pertuzumab PET Imaging Reveals Paclitaxel Treatment Efficacy Is Positively Correlated with HER2 Expression in Human Breast Cancer Xenograft Mouse Models

Paclitaxel (PTX) treatment efficacy varies in breast cancer, yet the underlying mechanism for variable response remains unclear. This study evaluates whether human epidermal growth factor receptor 2 (HER2) expression level utilizing advanced molecular positron emission tomography (PET) imaging is correlated with PTX treatment efficacy in preclinical mouse models of HER2+ breast cancer. HER2 positive (BT474, MDA-MB-361), or HER2 negative (MDA-MB-231) breast cancer cells were subcutaneously injected into athymic nude mice and PTX (15 mg/kg) was administrated. In vivo HER2 expression was quantified through [⁸⁹Zr]-pertuzumab PET/CT imaging. PTX treatment response was quantified by [¹⁸F]-fluorodeoxyglucose ([¹⁸F]-FDG) PET/CT imaging. Spearman’s correlation, Kendall’s tau, Kolmogorov–Smirnov test, and ANOVA were used for statistical analysis. [⁸⁹Zr]-pertuzumab mean standard uptake values (SUV_mean) of BT474 tumors were 4.9 ± 1.5, MDA-MB-361 tumors were 1.4 ± 0.2, and MDA-MB-231 (HER2−) tumors were 1.1 ± 0.4. [¹⁸F]-FDG SUV_mean changes were negatively correlated with [⁸⁹Zr]-pertuzumab SUV_mean (r = −0.5887, p = 0.0030). The baseline [¹⁸F]-FDG SUV_mean was negatively correlated with initial [⁸⁹Zr]-pertuzumab SUV_mean (r = −0.6852, p = 0.0002). This study shows PTX treatment efficacy is positively correlated with HER2 expression level in human breast cancer mouse models. Molecular imaging provides a non-invasive approach to quantify biological interactions, which will help in identifying chemotherapy responders and potentially enhance clinical decision-making.     

On the Intertwining of \partial{\mathcal{D}}-Isometries

Let be a strictly pseudoconvex bounded domain in with C ² boundary . If a subnormal m-tuple T of Hilbert space operators has the spectral measure of its minimal normal extension N supported on , then T is referred to as a -isometry. Using some non-trivial approximation theorems in the theory of several complex variables, we establish a commutant lifting theorem for those -isometries whose (joint) Taylor spectra are contained in a special superdomain Ω of . Further, we provide a function-theoretic characterization of those subnormal tuples whose Taylor spectra are contained in Ω and that are quasisimilar to a certain (fixed) -isometry T (of which the multiplication tuple on the Hardy space of the unit ball in is a rather special example). Submitted: September 9, 2007. Revised: October 10, 2007. Accepted: October 24, 2007.     

Nucleophilic ring opening reactions of aziridines

Aziridine ring opening reactions have gained tremendous importance in the synthesis of nitrogen containing biologically active molecules. During recent years, a great effort has been put forward by scientists toward unique bond construction methodologies via ring opening of aziridines. In this regard, a wide range of chiral metal- and organo-catalyzed desymmetrization reactions of aziridines have been reported with carbon, sulfur, oxygen, nitrogen, halogen, and other nucleophiles. In this review, an outline of methodologies adopted by a number of scientists during 2013–2017 for aziridine ring opening reactions as well as their synthetic applications is described.