Statistical theory of fluids confined in quenched disordered porous media.

We develop a theory to calculate structural correlations and thermodynamic properties of a fluid confined in a random porous solid medium (matrix). We used density functional formalism to derive an annealed averaged expression for the density profile and excess free energy of fluid arising due to random fields of a particular realization of the matrix. After performing the second average over the quenched-disordered variables, the excess free energy is organized to give one- and two-body potentials for fluid particles. The average over disorder reduces the system to an effective one-component system of fluid in which particles feel one-body (external) potential and interact via effective pair potential. The effective pair potential is a sum of the bare (the one in the pure fluid) and the matrix-induced potential. The resulting partition function involves only fluid variables. Equations are derived for fluid-fluid and fluid-matrix correlation functions and for free energy, pressure, and chemical potential of the fluid. The theory is applied to a model system of hard spheres and results for the effective pair potential, correlation functions, and thermodynamic properties are reported. The effective pair potential is found to be attractive at the contact and develops a repulsive peak before decaying to zero. Results for pair correlation function and structure factor are compared with simulation results for several fluid densities at two matrix densities. In all the cases, a very good agreement has been found.

Enhanced Four-Electron Selective Oxygen Reduction Reaction at Carbon-Nanotube-Supported Sulfonic-Acid-Functionalized Copper Phthalocyanine.

In the present work, the oxygen reduction reaction (ORR) is explored in an acidic medium with two different catalytic supports (multi-walled carbon nanotubes (MWCNTs) and nitrogen-doped multi-walled carbon nanotubes (NMWCNTs)) and two different catalysts (copper phthalocyanine (CuPc) and sulfonic acid functionalized CuPc (CuPc-SO3 - )). The composite, NMWCNTs-CuPc-SO3 - exhibits high ORR activity (assessed based on the onset potential (0.57 V vs. reversible hydrogen electrode) and Tafel slope) in comparison to the other composites. Rotating ring disc electrode (RRDE) studies demonstrate a highly selective four-electron ORR (less than 2.5 % H2 O2 formation) at the NMWCNTs-CuPc-SO3 - . The synergistic effect of the catalyst support (NMWCNTs) and sulfonic acid functionalization of the catalyst (in CuPc-SO3 - ) increase the efficiency and selectivity of the ORR at the NMWCNTs-CuPc-SO3 - . The catalyst activity of NMWCNTs-CuPc-SO3 - has been compared with many reported materials and found to be better than several catalysts. NMWCNTs-CuPc-SO3 - shows high tolerance for methanol and very small deviation in the onset potential (10 mV) between the linear sweep voltammetry responses recorded before and after 3000 cyclic voltammetry cycles, demonstrating exceptional durability. The high durability is attributed to the stabilization of CuPc-SO3 - by the additional coordination with nitrogen (Cu-Nx ) present on the surface of NMWCNTs.

Co(II) Porphyrin-MWCNT Nanoconjugate as an Efficient and Durable Electrocatalyst for Oxygen Reduction Reaction.

Recently, researchers are seeking alternatives to replace Pt-based oxygen reduction reaction (ORR) catalysts used in fuel cells due to their high cost and certain stability and selectivity issues. For this purpose, we have synthesized a nanoconjugate, cobalt(II) porphyrin (5,10,15-triphenyl-20-(4-aminophenyl)porphyrinatocobalt(II), CoTPP-NH2) covalently attached to the acid-functionalized multiwalled carbon nanotubes and characterized by various techniques including UV-vis spectroscopy, FTIR, TGA, FESEM, TEM, and Raman spectroscopy. The oxygen reduction performance of the nanoconjugate is checked in basic medium. The ORR onset potential of the nanoconjugate-modified electrode is nearly the same as that of the state-of-the-art platinum-carbon electrode and stable for more than 3000 CV cycles with a 20 mV difference in the onset potential before and after the 3000 CV cycles. The above extrapolations reveal that the nanoconjugate has efficient performance for the ORR in basic medium.

Chaotic dynamics of small-sized charged Yukawa dust clusters.

In a recent work [Maity et al., Phys. Rev. E 102(2), 023213 (2020)] the equilibrium of a cluster of charged dust particles mutually interacting with screened Coulomb force and radially confined by an externally applied electric field in a two-dimensional configuration was studied. It was shown that the particles arranged themselves on discrete radial rings forming a lattice structure. In some cases with a specific number of particles, no static equilibrium was observed. Instead, angular rotation of particles positioned at various rings was observed. In a two-ringed structure, it was shown that the direction of rotation of the particles positioned in different rings was opposite. The direction of rotation was also observed to change apparently at random time intervals. A detailed characterization of the dynamics of small-sized Yukawa clusters, with a varying number of particles and different strengths of the confining force, has been carried out. The correlation dimension and the largest Lyapunov index for the dynamical state have been evaluated to demonstrate that the dynamics is chaotic. This is interesting considering that the charged microparticles have many applications in a variety of industrial processes.

Metal (Mn, Fe, Co, Ni, Cu, and Zn) Phthalocyanine-Immobilized Mesoporous Carbon Nitride Materials as Durable Electrode Modifiers for the Oxygen Reduction Reaction.

In the search for alternative sources to replace fossil fuels, carbon nitride materials can be used in a variety of ways. In the present work, porosity is introduced to the carbon nitride material using mesoporous silica material, MCM-41, as a hard template, and a mesoporous carbon nitride (MCN) material is synthesized. Further, the MCN is modified by immobilizing metal phthalocyanine (MPc, where M = Mn, Fe, Co, Ni, Cu, and Zn). The resulting MPc-incorporated MCN materials (MPc@MCN) were tested for the electrocatalytic oxygen reduction reaction (ORR) in acidic and basic media. Detailed studies reveal that the FePc@MCN and CoPc@MCN materials exhibit higher ORR activity than the other composites in 0.1 M KOH. FePc@MCN follows a direct four-electron oxygen reduction mechanism and shows ORR onset potential (vs RHE) at 0.93 V (in 0.1 M KOH), which is very close to the onset potential exhibited by the state-of-the-art material, Pt-C (1.0 V), and higher than several similar composites of MPc with carbon supports tested in similar environments. Besides, due to the inherent property of coordination through nitrogen present on the MCN, FePc@MCN shows excellent stability even after 3000 cyclic voltammetry (CV) cycles. FePc@MCN was found to have a better methanol tolerance in comparison to Pt-C in basic medium. CoPc@MCN shows a highly selective two-electron reduction reaction in both acidic and basic media at lower overpotential than many of the reported catalysts for the two-electron oxygen reduction. Therefore, these materials (FePc@MCN and CoPc@MCN) can be used as suitable alternatives to replace Pt and other expensive materials in ORR and related applications.

The solvent mediated interaction potential between solute particles: theory and applications.

In this paper we develop a theory to calculate the solvent mediated interaction potential between solute particles dispersed in a solvent. The potential is a functional of the instantaneous distribution of solute particles and is expressed in terms of the solute-solvent direct pair correlation function and the density-density correlation function of the bulk solvent. The dependence of the direct pair correlation function on multi-point correlations of the solute distribution is simplified with a mean field approximation. A self consistent approach is developed to calculate the effective potential between solute particles, the solute-solvent and the solute-solute correlation functions. The significance of the solvent fluctuations on the range of the effective potential is elucidated. The theory is applied to calculate equilibrium properties of the Asakura-Oosawa (AO) model for several values of solute and solvent densities and for several values of the particles size ratio. The results give a quantitative description of many-body effect on the effective potential and on the pair correlation functions.

Strain-transcending neutralization of malaria parasite by antibodies against Plasmodium falciparum enolase.

BACKGROUND: Plasmodium enolase is a target for the growth neutralizing antibodies. Interestingly, the three invasive stages i.e. sporozoites, merozoites, and ookinetes express this protein on their cell surface. Polyclonal anti-Plasmodium falciparum enolase (Pfeno) antibodies disrupt traversal of ookinete through mosquito mid-gut wall as well as have inhibitory effect on parasite growth at erythrocytic stage. In a recent study, it was observed that immunization with a unique epitope of parasite enolase (EWGWS) could confer partial protection against mouse malaria. Further validation is needed for the protective potential of this unique epitope in otherwise highly conserved enolase. METHODS: In order to investigate the efficacy of growth inhibitory potential of the epitope of P falciparum enolase, a monoclonal antibody specific to EWGWS is generated. In vitro parasite growth inhibition assays and passive immunization of Plasmodium yoelii (or Plasmodium berghei) infected mice were used to assess the parasite growth neutralizing activity of the antibody. RESULTS: Screening a panel of monoclonal antibodies raised against recombinant Pfeno that were specific to EWGWS resulted in isolation of H12E1. This antibody recognized only EWGWS epitope containing enolases. H12E1 strongly inhibited parasite growth in culture. This inhibition was strain transcending. Passive infusion of this antibody in P. yoelii or P. berghei infected mice showed significant reduction in parasitemia as compared to controls (p < 0.001). Surface Plasmon Resonance measurements indicated high affinity binding of H12E1 to P. falciparum enolase (KD ~ 7.6 × 10-9M). CONCLUSIONS: A monoclonal antibody directed against EWGWS epitope of Pfeno was shown to inhibit the growth of blood stage malarial parasites. This inhibition was species/strain transcending and is likely to arise due to blockade of enolase on the surface of merozoites, functionally implicating Pfeno in invasion related events. Presence of enolase on the cell surface of merozoites and ookinetes could potentially result in inhibition of host cell invasions at erythrocytic and transmission stages in the parasite life cycle. It is suggested that antibodies against EWGWS epitope have the potential to confer dual stage, species and strain transcending protection against malaria.

KHMDS mediated synthesis of 9-arylfluorenes from dibenzothiophene dioxides and arylacetonitriles by tandem SNAr-decyanation-based arylation.

A straightforward KHMDS mediated synthetic route to 9-arylfluorenes from readily available starting materials has been developed. This reaction involves SNAr reactions of dioxide with arylacetonitriles, followed by decyanation reaction. The proposed transformation can also be used to furnish a densely arylated indene.

Confidence Interval: Advantages, Disadvantages and the Dilemma of Interpretation.

Confidence interval (CI) is one of the important reporting tools for research data as it not only provides valuable information about the effect size along with its width but also possible clinical significance. Unfortunately, this approach is not being utilized to its fullest extent. Determining point estimate always includes an element of uncertainty due to associated sampling error. A confidence interval may be an appropriate tool to measure this uncertainty. Further, the P value does not convey information about the magnitude of an effect and the error associated with it. Thus, in an ideal situation effect size should preferably be associated with a confidence interval to assess precision. Not only does CI let us assess likely effects but also decides whether the intervention applied could have clinical utility. In contrast, the p-value limits our option to either reject any differences that are not significant or accept those that are. However, confidence intervals are commonly misinterpreted. It is imperative to understand that the CI is not the range of effects that 95% of patients in the population exhibit. Moreover, it would also be erroneous to say that there is a 95% probability that the CI includes the true population effect. Interpretation is usually based on the context in which the confidence interval is being looked at. From a utility point of view and like other statistical tools confidence interval approach does have several advantages as well as disadvantages and is far beyond being a perfect statistical tool.

Structure formation by electrostatic interactions in strongly coupled medium.

The formation of correlated structures is of importance in many diverse contexts such as strongly coupled plasmas, soft matter, and even biological mediums. In all these contexts the dynamics are mainly governed by electrostatic interactions and result in the formation of a variety of structures. In this study, the process of formation of structures is investigated with the help of molecular dynamics (MD) simulations in two and three dimensions. The overall medium has been modeled with an equal number of positive and negatively charged particles interacting via long-range pair Coulomb potential. A repulsive short-range Lennard-Jones (LJ) potential is added to take care of the blowing up of attractive Coulomb interaction between unlike charges. In the strongly coupled regime, a variety of classical bound states form. However, complete crystallization of the system, as typically observed in the context of one-component strongly coupled plasmas, does not occur. The influence of localized perturbation in the system has also been studied. The formation of a crystalline pattern of shielding clouds around this disturbance is observed. The spatial properties of the shielding structure have been analyzed using the radial distribution function and Voronoi diagram. The process of accumulation of oppositely charged particles around the disturbance triggers a lot of dynamic activity in the bulk of the medium. As a result of this, close encounters are possible even between those particles/clusters which were initially and/or at some point of time widely separated. This leads to the formation of a larger number of bigger clusters. There are, however, also instances when bound pairs break up and the electrons from bound pairs contribute to the shielding cloud, whereas ions bounce back into the bulk. A detailed discussion of these features has been provided in the manuscript.

Antiplasmodial and Antimalarial Activity of 3,5-Diarylidenetetrahydro-2H-pyran-4(3H)-ones via Inhibition of Plasmodium falciparum Pyridoxal Synthase.

A series of 22 different 3,5-diarylidenetetrahydro-2H-pyran-4(3H)-ones (DATPs) were synthesized, characterized, and screened for their in vitro antiplasmodial activities against chloroquine (CQ)-sensitive Pf3D7, CQ-resistant PfINDO, and artemisinin-resistant PfMRA-1240 strains of Plasmodium falciparum. DATP 19 (3,5-bis(4-hydroxy-3,5-dimethoxybenzylidene)tetrahydro-2H-pyran-4(3H)-one) was found to be the most potent (IC50 1.07 µM) against PfMRA-1240, whereas 21 (3,5-bis(3,4,5-trimethoxybenzylidene)tetrahydro-2H-pyran-4(3H)-one) showed IC50 values of 1.72 and 1.44 µM against Pf3D7 and PfINDO, respectively. Resistance indices (RI) as low as 0.2 to 0.5 for 10 (3,5-bis(4-nitrobenzylidene)tetrahydro-2H-pyran-4(3H)-one) and 20 (3,5-bis(3-nitrobenzylidene)tetrahydro-2H-pyran-4(3H)-one), and <1 for most other DATPs reveals their greater potency against resistant strains than the sensitive one. The single-crystal XRD data for DATP 21 are reported. In silico support was obtained through docking studies. Killing all three strains within 4-8 h, these DATPs showed rapid kill kinetics toward the trophozoite stage. Furthermore, DATP 18 (3,5-bis(quinolin-4-ylmethylene)tetrahydro-2H-pyran-4(3H)-one) inhibited PfPdx1 enzyme activity with IC50 20.34 µM, which is about twofold lower than that (IC50 43 µM) for an already known inhibitor 4PEHz. At an oral dose of 300 mg/kg body weight, DATPs 19 and 21 were found to be nontoxic to mice, and at 100 mg/kg body weight, DATP 19 was found to suppress parasitaemia, which led to an increase in median survival time by three days relative to untreated control mice in a malaria curative study.

Growth Assessment of Under-Five Children of Employed and Unemployed Mothers of Etawah District, Uttar Pradesh: A Cross-Sectional Study.

Introduction The under-five age group is crucial because the health profile of this age group will have a huge effect on the future development of the nation. Early infancy is marked by several distinct developmental characteristics. Progress in each domain of childhood development is used to track a child's development. Objectives The objectives of the present study were to assess and compare the growth of under-five children of employed and unemployed mothers in the Etawah District of Uttar Pradesh, India. Material and methods A community-based cross-sectional survey was carried out in Etawah district's urban and rural areas between January 2021 and June 2022. A total of 200 mothers with children under the age of five were recruited using the purposive sampling method. To gather pertinent information, a semi-structured, pre-tested, interviewer-administered questionnaire was used. Results In the present study on the comparison of the growth of children among employed and unemployed mothers, it shows that 48 children (50.5%) with a weight between 10.5 and 15 kg were of employed mothers, while 52 children weighing less than 10.5kg were of unemployed mothers (p<0.001). Forty-four children (57.1%) with a chest circumference of more than 48 cm were of employed mothers, while 26 children (78.8%) with a chest circumference of less than 45 cm were of unemployed mothers (p = 0.001). Conclusion The present study indicates that statistically significant differences were found in age-appropriate gain in weight and chest circumference, which was higher among the children of employed mothers in comparison to children of unemployed mothers. There was no statistically significant difference in age-appropriate gain in height, head circumference, or mid-upper arm circumference among the children of employed mothers and unemployed mothers.

Remediation of noxious wastewater using nanohybrid adsorbent for preventing water pollution.

Removal of toxic elements from wastewater effluent has got a lot of attention because of their severe negative effects on human and environmental health. In the past few years, rapid urbanization and industrial activities in developing countries have exacerbated the destruction of the environment. Most of the wastewater effluents are discharged untreated or inadequately treated, which has become a major concern due to its impact on sustainability and the environment. This is imperative to implement, innovative and resourceful wastewater treatment technologies requiring low investment. Among the various treatment technologies, cutting-edge processes in nano-material sciences have recently piqued the interest of scientists. Nanohybrid absorbents have the potential in improving wastewater treatment and increase water supply by utilizing unconventional water resources. Carbon nanotubes, titanium oxide, manganese oxide, activated carbon (AC), magnesium oxide, graphene, ferric oxides, and zinc oxide are examples of nano-adsorbents that are used to eliminate pollutants. This also demonstrated the effective removal of contaminants along with the harmful effects of chemicals, colorants, and metals found in wastewater. The present manuscript examines potential advances in nanotechnology in wastewater treatment for the prevention of water and soil pollution. This systematic review aims to highlight the importance of nanohybrid absorbents treatment technology for wastewater treatment and to explain how nanohybrid absorbents have the potential to revolutionize industrial pollution. There are also other published review articles on this topic but the present review covers an in-depth information on nano-adsorbents and their targeted contaminants.

Specialized antiplasmodial secondary metabolites from Aspergillus niger 58, an endophytic fungus from Terminalia catappa.

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia catappa L. (West Indian-Almond) is a medicinal plant used in traditional medicine for the treatment of infectious diseases. Moreover, various organic extracts prepared from this plant have been reported to exhibit antiplasmodial activity. AIM OF THE STUDY: The need for new antimalarials is still an urgency driven by the alarmingly high burden of malaria in endemic regions, with multitude of people dying annually. We have previously identified an endophytic fungus Aspergillus niger 58 harboured by T. catappa as having promising specialized secondary metabolites against the malaria parasites. In the present study, we report the antiplasmodial activity-guided chromatographic isolation of some metabolites secreted by this endophytic fungus. MATERIALS AND METHODS: The SYBR Green I-based fluorescence microtiter plate assay was used to monitor the growth of Plasmodium falciparum parasites in culture in the presence and absence of inhibitors and results were validated by microscopic analysis of Giemsa-stained culture smears. Giemsa-stain microscopy was also used to study the cell cycle stage-specific action of selected fractions. RESULTS: The results revealed that the multidimensional purification of the crude extract (IC50: 4.03 µg/mL) provided RPHPLC F17 (IC50: 0.09 µg/mL) and RPHPLC F18 (IC50: 0.1 µg/mL) with activity against P. falciparum 3D7 (Pf3D7) strain. Moreover, both fractions at IC99 (0.5 µg/mL) exhibited multi-stages action by targeting all the three stages of the life cycle of blood-stage Pf3D7. Two compounds, flavasperone (1) and aurasperone A (2) were isolated, of which aurasperone A exhibited good potency against Pf3D7 (IC50: 4.17 µM) and P. falciparum INDO (PfINDO) (IC50: 3.08 µM). CONCLUSION: Our study adds credence to the notion that endophytic extracts are potential storehouses for potent specialized secondary metabolites that can be harnessed to fight the malaria parasite and reduce the burden of this disease worldwide. An endophyte that can be cultured in laboratory with ability to secrete promising metabolites of medicinal value holds the promise of conserving Nature from the threat of annihilation of flora for medicinal purposes.

Dynamical states in two-dimensional charged dust particle clusters in plasma medium.

The formation of dynamical states for a collection of dust particles in two dimensions is shown using molecular dynamics simulations. The charged dust particles interact with each other with a Yukawa pair potential mimicking the screening due to plasma. An external radial confining force has also been applied to the dust particles to keep them radially confined. When the particle number is low (say, a few), they get arranged on the radial locations corresponding to multiple rings or shells. For specific numbers, such an arrangement of particles is stationary. However, for several cases, the cluster of dust particles relaxes to a state for which the dust particles on rings display intershell rotation. For a larger number of dust particles (a few hundred, for instance), an equilibrium state with a coherent rigid body displaying angular oscillation of the entire cluster is observed. A detailed characterization of the formation of these states in terms of particle number, coupling parameter, etc., is provided.