K-Carrageenan Stimulates Pre-Osteoblast Proliferation and Osteogenic Differentiation: A Potential Factor for the Promotion of Bone Regeneration?

Current cell-based bone tissue regeneration strategies cannot cover large bone defects. K-carrageenan is a highly hydrophilic and biocompatible seaweed-derived sulfated polysaccharide, that has been proposed as a promising candidate for tissue engineering applications. Whether κ-carrageenan can be used to enhance bone regeneration is still unclear. In this study, we aimed to investigate whether κ-carrageenan has osteogenic potential by testing its effect on pre-osteoblast proliferation and osteogenic differentiation in vitro. Treatment with κ-carrageenan (0.5 and 2 mg/mL) increased both MC3T3-E1 pre-osteoblast adhesion and spreading at 1 h. K-carrageenan (0.125–2 mg/mL) dose-dependently increased pre-osteoblast proliferation and metabolic activity, with a maximum effect at 2 mg/mL at day three. K-carrageenan (0.5 and 2 mg/mL) increased osteogenic differentiation, as shown by enhanced alkaline phosphatase activity (1.8-fold increase at 2 mg/mL) at day four, and matrix mineralization (6.2-fold increase at 2 mg/mL) at day 21. K-carrageenan enhanced osteogenic gene expression (Opn, Dmp1, and Mepe) at day 14 and 21. In conclusion, κ-carrageenan promoted MC3T3-E1 pre-osteoblast adhesion and spreading, metabolic activity, proliferation, and osteogenic differentiation, suggesting that κ-carrageenan is a potential osteogenic inductive factor for clinical application to enhance bone regeneration.     

Improvement in the Performance of Composite Cathode via Solid Electrolyte for High Electrochemical Performance of Li–S Battery

Commercialization of Li–S in present scenario is obstructed by poor performance of cathode and its compatibility with electrolyte used. Here in this work, in order to improve the electrochemical performance all solid state Li–S battery, solid electrolyte (SE) formed by composition of lithium sulfide (Li₂S) and phosphorus pentasulfide (P₂S₅) combinedly called LPS is used. The modified carbon in the form of graphene oxide (GO) and reduced graphene oxide (rGO) as additive is used to provide better electron conduction pathway. High conductivity of the order 10⁻⁴ S cm⁻¹ of prepared LPS overcomes the major drawback of insulating nature of sulfur. The coin cells are fabricated by using above mentioned material as a cathode material, LPS as SE, and lithium foil as anode. The prepared nanocomposites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) to study structural and morphological properties. Energy dispersive X-ray spectroscopy (EDS) images of the cathode surface confirms the uniform spreading of material. The electrochemical performance of coin cell is studied by Galvanostatic charge-discharge plot at 0.1 C to check the compatibility of composite and electrolyte prepared. The cells having additive material GO and rGO with host sulfur show better results as compared to the cell having pristine sulfur.     

Gastroprotective Effects of Biological Macromolecule: Polysaccharides

The large molecular weight of the macromolecules sets them apart from all other components. This may range from 10 000 to over a million. While the molecular weight of other plant metabolites is seldom beyond 1000. Chemically, macromolecules are made up of long chains and little “building pieces,” which are joined covalently in a variety of ways. Biological macromolecules are large, naturally occurring cellular building blocks that play a range of crucial roles in the development and existence of living organisms. Biomacromolecules are essential in the biomedical field and other related professions. They feature a variety of beneficial properties, including excellent biodegradability, suitable mechanical strength, enhanced bioavailability, etc. They also have significant biocompatibility. They display a variety of biological characteristics, such as antimalignant, antidiabetic, antibacterial, antioxidant, and immunomodulatory. The use of essential carbohydrates including alginate, chitosan, pectin, starches, carrageenan, fucoidan, etc. is common in commercial applications. Natural substance-based pharmacotherapy is now considered to be a highly promising future alternative to conventional medicine. Along with proteins and polynucleotides, polysaccharide is a vital biomacromolecule that has a crucial function in the growth and expansion of living things. A crucial element of higher plants, cell membranes of animal, and cell walls of microbes is polysaccharide. It is intimately tied to physiological processes as well. The importance of polysaccharides as a significant class of bioactive natural compounds has received more attention recently. Numerous studies have shown that natural polysaccharides contain bioactivities, which have led to the use of polysaccharides in the treatment of illness. The many parts of the research findings on the bioactivities of polysaccharides in gastro-protection are included in this paper.     

Esterification of butyric acid with n-butanol: Kinetic study using experimental data and modeling

Present study involves the investigation of the esterification kinetics between butyric acid and n-butanol. This reaction was conducted in a batch reactor, utilizing homogeneous methanesulfonic acid (MSA) catalyst. Response surface methodology (RSM) was conducted prior to the kinetic study using “Design Expert; version-11.0” for finding the causal factors influencing the conversion of butyric acid. Most important factors identified with their limits against conversions (during optimization of the process using RSM) were taken up to critically analyze the effect of them on butyric acid conversion. Concentration and activity-based model of the process were proposed assuming second order reversible reaction scheme using homogeneous MSA catalyst. During the study of non-ideal behavior of the system, UNIFAC model was adapted for assessing the activity coefficients of species present in equilibrated liquid phase. Experimental data were used to evaluate kinetic and thermodynamic parameters such as rate constants, activation energy, enthalpy, and entropy of the system. The endothermic nature of esterification was confirmed by positive value of enthalpy obtained. The effect of various levels of causal variables like temperature (60–90°C), catalyst concentration (0.5–1.5 wt.%), and molar ratio of n-butanol to butyric acid (1–3) on conversion kinetics of butyric acid was investigated during transient and equilibrium phase of the reaction. It has been observed that molar ratio of butanol to butyric acid has the highest influence on the conversion. The rate equation derived offered a kinetic and thermodynamic framework to the generated data. It also exhibits a notable degree of conformity of predicted data to the experimental ones and effectively characterizes the system across different reaction temperatures, reactant molar ratio, and catalyst concentration.     

Degeneracy in one dimension: Role of singular potentials

That the bound energy eigenstates of one-dimensional quantum systems can be degenerate in the presence of specific singular or supersingular potentials is demonstrated by choosing a family of bistable and other oscillators. Relevance of our study to spectroscopic observations is noted. Quasi-degeneracy is found even in the absence of any singularity in the potential and the importance of tunneling is highlighted in this context to analyze the general nature of such potentials leading to double degeneracy. Additionally, the case of spiked oscillators is discussed with particular reference to the “Klauder phenomenon,” revealing clearly that the mere presence of singularity in the potential is not a sufficient criterion for the occurrence of degeneracy. © 1996 John Wiley & Sons, Inc.     

Chemical Degradation of Mercury Alkyls Mediated by Copper Selenide Nanosheets

Methylation and demethylation of mercury compounds are two important competing processes that control the net production of highly toxic mercury alkyls, methylmercury (MeHg⁺) and dimethylmercury (Me₂Hg), in environment. Although the microbial and the photochemical methylation and demethylation processes are well studied in recent years but the chemical methylation and demethylation processes have not been studied well. Herein, we report for the first time that the CuSe nanosheet has remarkable ability to activate the highly inert Hg?C bonds of various MeHg⁺ and Me₂Hg compounds at room temperature (21 °C). It facilitates the conversion of MeHg⁺ into Me₂Hg in the absence of any proton donors. Whereas, in the presence of any proton source, it has unique ability to degrade MeHg⁺ into CH₄ and inorganic mercury (Hg²⁺). Detailed studies revealed that the relatively fast Hg?C bond cleavage was observed in case of MeHgSPh or MeHgI in comparison to MeHgCl, indicating that the Hg?C bond in MeHgCl is relatively inert in nature. On the other hand, the Hg?C bond in Me₂Hg is considered to be exceedingly inert and, thus, difficult to cleave at room temperature. However, CuSe nanosheets showed unique ability to degrade Me₂Hg into CH₄ and Hg²⁺, via the formation of MeHg⁺, under acidic conditions at room temperature. DFT calculations revealed that the Hg?C bond activation occurs through adsorption on the surface of (100)‐faceted CuSe nanosheets.     

Quantum Phase Properties of Photon Added and Subtracted Displaced Fock States

Quantum phase properties of photon added and subtracted displaced Fock states (and their limiting cases) are investigated from a number of perspectives, and it is shown that the quantum phase properties are dependent on the quantum state engineering operations performed. Specifically, the analytic expressions for quantum phase distributions and angular Q distribution as well as measures of quantum phase fluctuation and phase dispersion are obtained. The uniform phase distribution of the initial Fock states is observed to be transformed by the unitary operation (i.e., displacement operator) into non‐Gaussian shape, except for the initial vacuum state. It is observed that the phase distribution is symmetric with respect to the phase of the displacement parameter and becomes progressively narrower as its amplitude increases. The non‐unitary (photon addition/subtraction) operations make it even narrower in contrast to the Fock parameter, which leads to broadness. The photon subtraction is observed to be a more powerful quantum state engineering tool in comparison to the photon addition. Further, one of the quantum phase fluctuation parameters is found to reveal the existence of antibunching in both the engineered quantum states under consideration. Finally, the relevance of the engineered quantum states in the quantum phase estimation is also discussed.     

A 236 GHz Fe3+ EPR Study of Nanoparticles of the Ferromagnetic Room-Temperature Semiconductor Sn1−x Fe x O2 (x = 0.005)

High-frequency (236 GHz) electron paramagnetic resonance (EPR) studies of Fe³⁺ ions at 255 K are reported in a Sn_1?x Fe _x O₂ powder with x = 0.005, which is a ferromagnetic semiconductor at room temperature. The observed EPR spectrum can be simulated reasonably well as the overlap of spectra due to four magnetically inequivalent high-spin (HS) Fe³⁺ ions (S = 5/2). The spectrum intensity is calculated, using the overlap I(BL) + (I(HS1) + I(HS2) + I(HS3) + I(HS4)) × exp(?0.00001B), where B is the magnetic field intensity in Gauss, I represents the intensity of an EPR line (HS1, HS2, HS3, HS4), and BL stands for the baseline (the exponential factor, as found by fitting to the experimental spectrum, is related to the Boltzmann population distribution of energy levels at 255 K, which is the temperature of the sample in the spectrometer). These high-frequency EPR results are significantly different from those at X-band. The large values of the zero-field splitting parameter (D) observed here for the four centers at the high frequency of 236 GHz are beyond the capability of X-band, which can only record spectra of ions with much smaller D values than those reported here.