Neutron Equivalent Dose Rate Measurements of Gypsum-Waste Tire Rubber Layered Structures

The neutron equivalent dose rates (µSv/h) of gypsum, steel-reinforced rubber waste tire, and gypsum-waste tire rubber sandwich composite samples were investigated. Prepared samples were irradiated with ²⁴¹Am-Be neutrons and transmission values were obtained using dose equivalent rates measured with a BF₃ neutron detector. Results were compared to those of concrete, and as a result of neutron shielding, the performance of gypsum, waste tire, and waste tire (steel-reinforced rubber) embedded gypsum samples was higher than that of concrete. This information may be useful for shielding design of nuclear application areas.     

Amberlyst-15 Catalyzed Synthesis of α′-Oxindole-α-Hydroxyphosphonates under Ultrasonic Irradiation

Abstract

An efficient and environment friendly protocol for the synthesis of α′-oxindole–α-hydroxyphosphonates by the condensation of substituted isatin and dialkylphosphite in the presence of amberlyst-15 is reported. This reaction gives good to excellent yields of products under heating and sonication conditions.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures.     

Efficient One-Pot Synthesis of 4-Aroyl-2-pyrones: Nucleophilic Addition of Active Methylene Groups to 1,2-Diaroylacetylenes

An efficient synthesis of 3,6-disubstituted-4-aroyl-2-pyrones in a single-step reaction through Michael addition of 1,2-diaroylacetylenes with active methylene compounds in the presence of NaH in dimethylsulfoxide at room temperature is reported. The structures have been confirmed by spectral data analyses.

Preparation & characterization of embelin�Cphospholipid complex as effective drug delivery tool

The aim of the present study was to prepare an embelin?Cphospholipid complex (EPC) formulation in an attempt to enhance the water solubility and to characterize the new developed formulation. Embelin, due to water insolubility causes poor bioavailability by oral route. To improve the bioavailability and prolong its duration in body system, its phospholipid complexes were prepared by a simple and reproducible method. EPC was formulated by mechanical dispersion method using ethanol as a reaction medium, embelin and phospholipids were dissolved into the medium, after that organic solvent was removed under vacuum condition and EPC was formed. The complex formation was confirmed by carrying out FTIR, ¹H-NMR, XRD, DSC and microscopical studies. Solubility and in vitro studies were carried out to ascertain the solubility and dissolution pattern of free and complexed embelin. Content of embelin in EPC was found to be 92.44% (w/w). FTIR, ¹H NMR, DSC and XRD data confirmed the formation of embelin phospholipid complex. Water solubility of embelin was improved from 3 to 42 ??g/mL in the prepared complex. n-Octanol solubility were also altered for free embelin and EPC from 2.3 to 39 ??g/mL. Unlike the free embelin, which showed a total of only 19% drug release at the end of 120 min, EPC showed 99.80% release at the end of 120 min of dissolution study in distilled water. Microscopical characterization of the developed formulation also showed the entrapment of embelin in the lipid core showing complex structure, which was further, supported by change in surface morphology of embelin on microscopical examination. Hence, the present findings demonstrate that complexing embelin with phospholipid can be further explored for improved therapeutic implications.     

Expression of MMP2 and MMP9 (Gelatinases A and B) in Human Colon Cancer Cells

Matrix metalloproteinases (MMPs) are a family of zinc-dependent neutral endopeptidases, collectively capable of degrading essentially all matrix components. Elevated levels of distinct MMPs are detected in tumor tissue or serum of patients with advanced cancer, and they are the major prognostic indicators in cancer. Inhibition of MMPs has been explored as a therapeutic goal for almost two decades. Nitric oxide (NO), a free radical plays an important role in signaling pathways in regulation of MMP expression. In the present study, we demonstrated the role of exogenous NO levels in the regulation of MMP2 and MMP9 (gelatinases A and B) in colon cancer cell line WiDr and its inhibition with emodin (a naturally occurring anthraquinone).     

Bath Engineering Enhanced Quantum Critical Engines

Driving a quantum system across quantum critical points leads to non-adiabatic excitations in the system. This in turn may adversely affect the functioning of a quantum machine which uses a quantum critical substance as its working medium. Here we propose a bath-engineered quantum engine (BEQE), in which we use the Kibble–Zurek mechanism and critical scaling laws to formulate a protocol for enhancing the performance of finite-time quantum engines operating close to quantum phase transitions. In the case of free fermionic systems, BEQE enables finite-time engines to outperform engines operating in the presence of shortcuts to adiabaticity, and even infinite-time engines under suitable conditions, thus showing the remarkable advantages offered by this technique. Open questions remain regarding the use of BEQE based on non-integrable models.