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The scattering function of ideal two-dimensional symmetric pom-pom polymers
The properties of ideal two-dimensional star and pom-pom polymers containing 601–1263 units are investigated with a Monte Carlo growth method. The mean-square radii of gyration, various g-ratios, and scattering functions are calculated. A graph theory approach is employed to obtain exact scattering functions using a novel technique for counting paths in the graph representation of the polymers. All the simulation results are in very good agreement with theoretical predictions. Pom-poms are more similar to two joined stars with a smaller number of branches, rather than stars with the same number of branches.
Stepwise Epitaxial Growth of Core–Shell Organic Crystals for Advanced Dual-Emission Optical Applications
Effects of heat reflux extraction on the content, antioxidant, and immune activity of polyphenols and flavonoids from hempseed threshing residues
Objective Hempseed threshing residues are rich in phytochemicals such as polyphenols and flavonoids. Phenolic and flavonoid compounds have been associated with antioxidant, antibacterial and anticancer activities. The re-use of the hempseed threshing residues as value-added materials is, not only cost-saving, but also environmentally beneficial. It is therefore important to develop an effective method for extraction of phenolic compounds and flavonoids from hempseed threshing residues. Methods In this investigation, the extraction of phenolic constituents and flavonoids from hempseed threshing residues using heat reflux extraction (HRE) were optimized through response surface methodology (RSM). Four HRE parameters to enhance the yield of crude extracts (CE), total phenolic content (TPC), and total flavonoids content (TFC) were evaluated. Additionally, the study evaluated the chemical compounds, antioxidant characteristics of the extracts, and the immune activity of the extracts was assessed by quantifying the levels of inflammatory cytokines, specifically IL-6, IL-10, and TNF-α. Results The best extraction parameters were determined as: for the extraction time of 69.71 min, a liquid-solid proportion of 5.12:1, a particle size of 1150 µm, and an ethanol concentration of 69.60%. Under these optimized conditions, the yields for CE, TPC, and TFC were 4.74%, 27.54%, and 16.02% respectively. The data conformed well to multiple regression models, showing that these extraction parameters markedly influence the yields of CE, TPC, and TFC. Most of the compounds found may belong to the class of polyphenol and flavonoids. Cellular assays indicated that extracts from hempseed threshing residue notably reduced pro-inflammatory factors (TNF-α, IL-6) and increased anti-inflammatory factors (IL-10) in RAW 264.7 cells. Conclusion This research lays a theoretical foundation for extracting polyphenols and flavonoids from hempseed threshing residue and for the comprehensive assessment of antioxidant and immune-enhancing products. However, the antioxidant and immune activity of hempseed threshing residues extracts under physiological conditions in vivo, and the relevant mechanism should be further studied.
Aneesur Rahman: Pioneer of molecular simulation
Retraction: The combination of organic and inorganic fertilizers influence the weed growth, productivity and soil fertility of monsoon rice
Vacuum ultraviolet photoionization and dissociative photoionization of acetyl (CH3CO) and vinoxy (CH2CHO) radicals
The vacuum ultraviolet photoionization and dissociative photoionization of isomeric radicals, acetyl (CH3CO) and vinoxy (CH2CHO), have been studied using synchrotron radiation double imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy. Mass-selected threshold photoelectron spectra (ms-TPES) corresponding to the parent cations (m/z = 43, CH3CO+ and CH2CHO+) and their fragment ions (m/z = 15, CH3+) are measured and assigned based on theoretical calculations. The first and second bands of the ms-TPES of m/z = 43 are mainly unstructured due to the large molecular configuration changes upon photoionization, and they are attributed to contributions of the singlet ground state of CH3CO+ and CH2CHO+. The ms-TPES of m/z = 15 exhibit a rich structure with two vibrational series superimposed onto a broad envelope. The first vibrational series is attributed to the photoionization of the methyl radical (CH3), generated from secondary reactions in the flow tube reactor, while the second series is attributed to pre-dissociation of the triplet electronic state of CH2CHO+, and the statistical dissociation of ground state CH3CO+ in high vibrational levels contributes to the broad envelope. The dissociation mechanisms for the generation of CH3+ from CH3CO+ and CH2CHO+ are also discussed with the aid of a theoretical energy diagram and a breakdown diagram. In particular, a dissociation mechanism is proposed, in which CH2CHO+ in a triplet electronic state first undergoes an intersystem crossing into the singlet electronic state, followed by a structural rearrangement and dissociation into CH3+ along the singlet minimum energy path of CH3CO+.
Perovskite Catalysts for Pure-Water-Fed Anion-Exchange-Membrane Electrolyzer Anodes: Co-design of Electrically Conductive Nanoparticle Cores and Active Surfaces
Empowering visually impaired students through innovative tools and accessible waste sorting education at the national level
Waste separation is a critical strategy to address the intensifying global waste crisis. However, inclusive teaching strategies for visually impaired students remain limited. This study addresses this pressing gap by implementing an innovative intervention rooted in experiential learning principles. This approach integrates sound-equipped bins and waste sorting activity guides tailored to empower visually impaired students to independently and effectively separate waste. The research study employed a mixed-methods design encompassing three key phases: (1) training teachers to proficiently use accessible tools and to deliver comprehensive waste management education, (2) training visually impaired students through hands-on experiential learning to develop independent waste separation skills, and (3) evaluating behavior changes and skill retention among students after the training. The results demonstrated significant statistical improvements in knowledge (mean increase = 0.74, p < 0.001), attitudes (mean increase = 0.50, p < 0.001), and practical skills (mean increase = 0.55, p < 0.001) by students. These findings highlight the transformative potential of inclusive educational innovations to bridge existing gaps and promote self-reliance in waste separation among visually impaired learners. The study emphasizes the importance of adopting creative, evidence-based strategies to ensure inclusivity and sustainability in environmental education on a global scale. Policymakers and educators are urged to leverage these insights to advance environmental literacy and foster equitable participation in waste management practices.
Determination of aqueous solubility of NaCl in molecular dynamics simulation using the Kirkwood–Buff method
Electrolyte solutions are central to a wide range of scientific and industrial applications, with ions in solution affecting properties as diverse as ion diffusion, solvation structure, and chemical potentials. However, accurately predicting the solubility of salts such as sodium chloride (NaCl) in molecular dynamics (MD) simulations is challenging. Existing methods, such as the direct coexistence method and the chemical potential route, provide insights but often require extensive computational resources or face limitations in reproducibility. In this study, we present an alternative approach using Kirkwood–Buff (KB) theory combined with MD simulations to estimate the solubility of NaCl. This “KB method” requires the calculation of ion–ion and ion–water Kirkwood–Buff integrals at different electrolyte concentrations based on a reference electrolyte chemical potential, yielding concentration-dependent chemical potentials. We calculated the solubility of five state-of-the-art NaCl models and found a clear link between ion pairing and solubility at low and moderately high electrolyte concentrations. Our results suggest that force fields with a mean number of contact ion pairs per ion between 0.014 and 0.025 in 1.0 molal aqueous electrolyte solution might be a good choice, offering valuable insights for future model refinement. By evaluating the computational efficiency of the KB method, we highlight its potential as a reliable tool to calculate the solubility of the future ion models.
Low-Temperature Nonoxidative Dehydrogenation of Short-Chain Alkanes over Copper(I) Mordenite via Chemical Looping
A comparative analysis of the burden, trends and inequalities of tracheal, bronchus, and lung cancer in India from 2000 to 2021: A systematic analysis for the Global Burden of Disease study 2021
Background Understanding the tracheal, bronchus, and lung (TBL) cancer burden caused by tobacco exposure in India can help local governments implement targeted measures for prevention and treatment of the disease. Methods The burden of TBL cancer deaths and disability-adjusted life years (DALYs) attributable to tobacco exposure from 2000 to 2021 were presented by age, sex, and region. A Joinpoint model was used to analyze temporal trends of the disease, while decomposition analysis was conducted to quantify the contributions of population growth, aging, and epidemiological changes. In addition, the age-period-cohort (APC) model was implemented to assess the effects of age, period, and cohort on tobacco-related TBL cancer deaths and DALYs burden. Finally, age-standardized deaths and DALYs rates for TBL cancer attributable to tobacco exposure were projected through 2035. Results In 2021, Mizoram recorded the highest age-standardized rates of TBL cancer deaths and DALYs attributable to tobacco exposure, regardless of sex. Uttar Pradesh and West Bengal consistently exhibited the highest number of deaths and DALYs associated with tobacco exposure across the three age groups analyzed. Population growth and aging are the primary drivers behind the increasing burden of TBL cancer. Overall, the risk of tobacco-related lung cancer death increased with age. There are differential period and cohort effects between male and female populations. In the future, the increase in age-standardized rates of deaths and DALYs attributable to secondhand smoke exposure will be more pronounced among males. Conclusion Despite ongoing efforts to control the tobacco epidemic, the burden of TBL cancer related to tobacco remains high in India. Each state in India should adopt targeted measures based on local conditions to address the health threats posed by tobacco.
Optical spectra of complex aggregates and crystals: Vibronic band structure and Davydov splitting
A thorough understanding of the nature and pattern of intermolecular interactions in molecular aggregates and crystals is a prerequisite for the design of the next generation of functional materials. In systems with multiple, symmetrically equivalent molecules per unit cell, each excited state of the isolated molecule splits into several Davydov components that appear in the absorption spectra in up to three orthogonally polarized transitions. In this work, a Frenkel–Holstein Hamiltonian is adopted to simulate the vibronic structure of the Davydov components in aggregates and crystals with up to four molecules per unit cell, where electrostatic intermolecular interactions define either 1D or 2D structures. Analysis shows that vibronic signatures report directly on the electronic couplings that contribute to the Davydov splitting and the exciton band shapes. Specifically, the vibronic signature of a given Davydov component is solely determined by its free excitonic shift. For crystals with two molecules per unit cell, the lower and upper Davydov components can each exhibit J-like or H-like behavior, resulting in JJ, JH, and HH components in order of increasing energy, all with unique vibronic signatures. Under certain conditions, null points can exist in either band, leading to a monomer-like absorption spectrum for the corresponding Davydov component. In crystals with four symmetrically equivalent molecules per unit cell, the J- or H-nature of the three orthogonally polarized Davydov components results in four possible combinations, JJJ, JJH, JHH, and HHH in order of increasing energy, all readily identified through vibronic signatures.
Controlling Glycan Folding with Ionic Functional Groups
Analysing the factor structure of the MAIA scale for pregnant women: Development of the MAIA-Preg
During pregnancy many elements of the bodily experience change, suggesting that measuring these constructs may require different instruments to those validated in the general population. This study reports an exploratory and confirmatory factor analysis exploration of the Multidimensional Assessment of Interoceptive Awareness (MAIA) in 716 pregnant women (mean gestation 26.4 weeks), from six different datasets who completed the MAIA online. Exploratory factor analysis condensed the questionnaire from a 32- to a 19- item scale, with five factor structure, which best fitted the data. Key subscales of Trust, Attention Regulation, Self-Regulation and Not Distracting remained robust. The one remaining item from the Noticing subscale loaded heavily with the Emotional Awareness subscale. Subscales of Body Listening, Not Worrying and Noticing did not load and therefore were excluded as factors. This led to the development of the scale referred to as the MAIA-Preg, which demonstrated a good fit with a confirmatory factor analysis along with good subscale reliability (ω= 0.73 -0.92), and measurement invariance for second and third trimesters. The MAIA-Preg was also found to be a good fit for separate non-pregnant (N = 396) and postnatal (N = 174) samples and thus provides a reliable and valid measure, providing nuanced information about the bodily experience in perinatal populations, allowing comparisons of changes to interoceptive sensibility the perinatal period.
Activation of <i>d</i> orbitals under pressure and stability of alkali metal iodides
High pressure has emerged as a powerful tool for synthesizing novel compounds and initiating specific chemical reactions in materials science. In this work, we employed first-principles calculations and the CALYPSO structure search technique to systematically investigate the crystal structure stability of MexIy (Me = Li, Na, K, Rb, and Cs) compounds at high pressures. Our predictions unveiled several new phases with both conventional and unconventional stoichiometries. Notably, we observed an opposing trend in the stability of alkali metal iodides at high pressures, and we explored this phenomenon from multiple perspectives. Our analysis revealed that the activation of inner-shell d orbitals in heavy alkali metals is a key factor driving the decomposition of these compounds. In particular, in alkali metal iodides, a significant number of electrons transfer from the 5p orbital of iodine to the d orbitals of the heavy alkali metals, leading to weakening of the ionic bonds and triggering of the decomposition of these compounds. This research not only provides valuable insights into the decomposition mechanisms and high-pressure properties of Me–I compounds but also significantly contributes to our knowledge of chemical reactions in geological systems under extreme conditions.
Subcellular Photocatalysis Enables Tumor-Targeted Inhibition of Thioredoxin Reductase I by Organogold(I) Complexes
Fiber architecture in the human ventromedial striatum and its relation with the bed nucleus of the stria terminalis
The bed nucleus of the stria terminalis (BST) and the ventromedial striatum (consisting of the head of the caudate nucleus (hCN) and the nucleus accumbens (NAcc)) are both part of complex, foremost limbic networks involved in a variety of neuropsychiatric conditions. However, data on functional or structural connections between the BST and hCN in humans are scarce. In an earlier study using both diffusion tensor magnetic resonance imaging (DTI) and conventional histology we found a pathway from the BST to the orbitofrontal cortex apparently passing directly through the hCN. To confirm this finding, we now examined the hCN in human ex-vivo brain tissue using polarized light microscopy (PLM), a method particularly suitable for depicting myelinated nerve fibers. We further examined whether differences in fiber distribution inside the hCN could be depicted using high-resolution DTI data. PLM revealed different fiber populations inside the hCN and the NAcc. Fibers in the hCN were mostly related to the anterior limb of the internal capsule (ALIC) with some apparently terminating in the hCN while the majority exited the hCN to enter the prefrontal white matter. Fibers originating from the BST were only scarcely seen on this level and appeared to either terminate inside the hCN or join the ALIC. On levels below the anterior commissure, the BST strongly connected 1) to other basal forebrain structures including the NAcc, and 2) with the white matter of the medial prefrontal cortex. Differences in fiber density within the hCN could be reproduced on MRI data but with strong interindividual variation. In summary, PLM revealed a much more complex fiber architecture in the region of interest than suggested by our earlier DTI findings. The study at hand shows that PLM can be a valuable tool for the verification of unclear or ambiguous DTI fiber tracking results.
Instabilities of ring-rivulets: Impact of substrate wettability
Rivulets and droplets are naturally appearing shapes when small amounts of liquid are deposited on a partially wettable substrate. Here, we study, by means of numerical simulations, the dewetting dynamics of a ring-rivulet on substrates with various contact angles and wettability patterns. In particular, we consider, beyond the homogeneous case, an annular band of lower contact angle compared to the background and a constant radial gradient of contact angle, pointing either inward or outward from the center. We show that by tuning the parameters characterizing the patterns, it is possible to control not only the stability of the rivulet, i.e., its breakup/collapse dynamics and the associated time scales, but also the dewetting morphology, in terms of the number and position of the formed droplets.