A new method for the calculation of Sommerfeld screening parameter σ1 in x-ray spectra

The paper describes a new method for the calculation of the Sommerfeld screening parameter σ₁. It requires neither the knowledge of the energy separations of spin doublet levels nor is it based on the application of the Hertz law. The only data required for the calculation are the experimental energy values of the level concerned for the series of elements belonging to the same subshell in which the element in the question is situated. As an illustration the values of σ₁ are calculated for the L ₁, L ₂ and L ₃ levels for elements belonging to the 4f subshell and these are found to be in excellent agreement with those published earlier by Gokhale and Misra. The method brings out the constancy of σ₁ (L ₂ L ₃)−σ₁(L ₁) in a natural way and may thus be regarded as providing theoretical explanation of the Hertz law.     

Role of Intracellular Iron in Switching Apoptosis to Ferroptosis to Target Therapy-Resistant Cancer Stem Cells

Iron is a crucial element required for the proper functioning of the body. For instance, hemoglobin is the vital component in the blood that delivers oxygen to various parts of the body. The heme protein present in hemoglobin comprises iron in the form of a ferrous state which regulates oxygen delivery. Excess iron in the body is stored as ferritin and would be utilized under iron-deficient conditions. Surprisingly, cancer cells as well as cancer stem cells have elevated ferritin levels suggesting that iron plays a vital role in protecting these cells. However, apart from the cytoprotective role iron also has the potential to induce cell death via ferroptosis which is a non-apoptotic cell death dependent on iron reserves. Apoptosis a caspase-dependent cell death mechanism is effective on cancer cells however little is known about its impact on cancer stem cell death. This paper focuses on the molecular characteristics of apoptosis and ferroptosis and the importance of switching to ferroptosis to target cancer stem cells death thereby preventing cancer relapse. To the best of our knowledge, this is the first review to demonstrate the importance of intracellular iron in regulating the switching of tumor cells and therapy resistant CSCs from apoptosis to ferroptosis.     

Oscillating Neutrino Mass States and Double Beta Decay

Physics of Atomic Nuclei - Neutrino oscillation is an experimentally established phenomenon by which neutrinos undergo flavor transformations periodically as they propagate large enough distances....     

Shape changes at high spin in 78Kr

High-spin states in ⁷⁸Kr have been studied via the ⁶³Cu (¹⁹F, 2p2n)⁷⁸Kr reaction at a beam energy of 60 MeV using the Indian National Gamma Array (INGA). In this nucleus, lifetimes have been measured upto the I^π=22⁺ level in the yrast positive-parity band and upto the I^π=15^- level in the negative-parity band using the Doppler Shift Attenuation Method (DSAM). The deduced transition quadrupole moments Q_t's are found to decrease with rotational frequency for both the bands.     

Fixed-width confidence intervals for contrasts in the means

The sequential procedure developed by Bhargava and Srivastava (1973, J. Roy. Statist. Soc. Ser. B, 35, 147–152) to construct fixed-width confidence intervals for contrasts in the means is further analyzed. Second-order approximations for the first two moments of the stopping time and the coverage probability associated with the sequential procedure, are obtained. A lower bound for the number of additional observations after stopping is derived, which ensures the mxact probability of coverage. Moreover, two-stage, three-stage and modified sequential procedures are proposed for the same estimation problem. Relative advantages and disadvantages of these sampling schemes are discussed and their properties are studied.     

A Novel Approach in Treatment of Tuberculosis by Targeting Drugs to Infected Macrophages Using Biodegradable Nanoparticles

Mycobacterium tuberculosis, the causative agent of tuberculosis is now causing death of more than 10 million people. Because of the development of drug-resistant TB, drug delivery to the infected site through nanoparticle had been studied for long time. Nanoparticles indicate different sorts of association with the natural particles of the body. Nanoparticles can be used as controlled or specific drug delivery system. It can be through temporal controlled or can be distribution controlled. Glucose polymer-based nanoparticles might play an important role as drug delivery system in case of targeted drug delivery in the infected site of the body or in infected macrophages, as they are biodegradable so there should not be any side effects of these particles in the body and also they show very slow immune response. CD4, Beta 1, TGFb-1, IL-2, IL-13 SEC14L1, GUSB, BPI, and CCR7 are major biomarkers secreted after infection of this bacterium by the macrophages which can be used for targeted drug delivery in infected macrophages. As these markers can be used for delivery of drugs at destined position, they can be very beneficial in reducing toxicities of antituberculer drugs to the other uninfected sites and in operating only the infected macrophages.     

From Linear to Angular Isomers: Achieving Tunable Charge Transport in Single‐Crystal Indolocarbazoles Through Delicate Synergetic CH/NH⋅⋅⋅π Interactions

Weak intermolecular interaction in organic semiconducting molecular crystals plays an important role in molecular packing and electronic properties. Here, four five‐ring‐fused isomers were rationally designed and synthesized to investigate the isomeric influence of linear and angular shapes in affecting their molecular packing and resultant electronic properties. Single‐crystal field‐effect transistors showed mobility order of 5,7‐ICZ (3.61 cm² V^?1 s^?1) >5,11‐ICZ (0.55 cm² V^?1 s^?1) >11,12‐ICZ (ca. 10^?5 cm² V^?1 s^?1) and 5,12‐ICZ (ca. 10^?6 cm² V^?1 s^?1). Theoretical calculations based on density functional theory (DFT) and polaron transport model revealed that 5,7‐ICZ can reach higher mobilities than the others thanks to relatively higher hole transfer integral that links to stronger intermolecular interaction due to the presence of multiple NH???π and CH???π(py) interactions with energy close to common NH???N hydrogen bonds, as well as overall lower hole‐vibrational coupling owing to the absence of coupling of holes to low frequency modes due to better π conjugation.     

A High Yielding, One-Pot, Triton-B Catalyzed, Expeditious Synthesis of Carbamate Esters by Four Component Coupling Methodology

Summary. A novel process for the one-step chemoselective conversion of alkyl halides into carbamates as protected amines was developed using benzyltrimethylammonium hydroxide (Triton-B) in presence of gaseous carbon dioxide. Thus, carbamate esters of different amines were prepared in very good to excellent yields. Present address: Institute of Organic and Biomolecular Chemistry, George–August University, 37077, G?ttingen, Germany     

A threefold superstructure of the anti‐epileptic drug phenytoin sodium as a mixed methanol solvate hydrate

Phenytoin sodium, a salt of 5,5‐diphenylimidazolidine‐2,4‐dione, or phenytoin, is commercially available in various dosage forms for its anti‐epileptic properties to treat and prevent seizures. The title compound, poly[aquatris(μ₃‐4,4‐diphenyl‐2,5‐dioxoimidazolidin‐1‐ido)trimethanoltrisodium(I)], [Na₃(C₁₅H₁₁N₂O₂)₃(CH₄O)₃(H₂O)_1.08]_n, a methanol solvate and hydrate of phenytoin sodium, forms a modulated crystal structure that consists of a supercell made up of three close‐to‐identical repeat units. Each of the basic fragments consists of one phenytoin anion, a sodium cation, and either a methanol, or a methanol and a water molecule coordinated to the sodium ion, yielding a formula unit of Na(C₁₅H₁₁N₂O₂)(CH₃OH)_x(H₂O)_y for each of the three segments (x, y = 0 or 1; x + y = 1 or 2). Modulation along the b axis is introduced due to the presence or absence of water or methanol molecules at sodium and by the alternating torsion angles of one of the two phenytoin phenyl rings. Individual segments within the asymmetric unit are linked by covalent Na—O and Na—N bonds, with each sodium ion coordinated to one anionic amide N atom and three keto O atoms. The Na—N and one of the Na—O bonds connect (C₁₅H₁₁N₂O₂)·Na units along the modulation direction, creating an infinite [(C₁₅H₁₁N₂O₂)·Na] chain that is further stabilized by intramolecular N—H…O hydrogen bonding parallel to [010]. The second Na—O bond connects this chain with a symmetry‐equivalent copy of itself created by a screw‐axis operation, yielding double strands of [(C₁₅H₁₁N₂O₂)·Na] chains. Two of these double strands, propagating in opposite directions, constitute the content of the unit cell. Neighboring double strands are connected with each other to form layers perpendicular to the a axis, tethered together via O—H…O hydrogen bonds involving the water and methanol molecules. In addition to modulation, each of the repeat units also exhibits disorder of the modulated segments. Phenyl rings of each repeat unit are rotationally disordered, and sodium‐coordinated methanol and water molecules are also positionally disordered and/or partially occupied. The solvated structure reported here, while not matching the patterns reported for any of the known forms of phenytoin sodium, does provide a first insight into the complications and complexities involved in resolving the structure of anhydrous phenytoin sodium.