Browse Articles

Phase-regulated energy funneling and carrier relaxation dynamics in quasi-2D perovskites revealed by micro-area transient absorption spectroscopy

Two-dimensional (2D) perovskites have attracted considerable attention as promising candidates for optoelectronic devices due to their excellent optical properties, structural tunability, and intrinsic quantum well architectures. Understanding how phase composition regulates ultrafast carrier dynamics is essential for optimizing device performance. In this work, monocrystalline thin films of (PEA)2(MA)n−1PbnI3n+1 with well-controlled phase distributions were prepared using a space-confined anti-solvent crystallization method. Micro-area femtosecond pump–probe spectroscopy was employed to investigate the influence of phase composition on the relaxation behavior of photoexcited carriers. The results reveal that increasing the proportion of small-n phases leads to a pronounced extension of the excited-state relaxation process in large-n domains, attributed to suppressed defect-assisted trapping and enhanced interphase carrier transfer efficiency. This study provides a microscopic physical picture of the energy funneling mechanism governed by phase composition in quasi-2D perovskites and establishes an experimental framework for regulating carrier dynamics.

Disagreement between human and AI evaluation of treatment plans

Structural engineering, BSA binding and computational analysis of isonipacotate based enzyme inhibitors containing 1,2,4-triazole

Synthetic chemistry facing little difficulties in C–C, C–S, and C–N double bonds activation is a very long-standing challenge. The current studies based on the development of C–N double and single bond, N–N bond and C–S in the trizole and azinane merged rings into single unit. The targeted compounds were obtained through metal free, microwave assisted and conventional techniques. The present work covers sulfonamide, hydrazide synthesis, 1,2,4-triazole, and thioether synthesis to produce piperidine-based triazole analogues ( 7a-j ). An array of electrophiles ( 6a-j ) was treated with 1,2,4-triazole ( 5 ) under conventional (59–72% yield) and microwave assisted (87–95% yield) protocols to acquire the targeted molecules ( 7a-j ). The proton and carbon NMR, and IR techniques were used for structural characterization. The analogues ( 7a-j ) were screened against BChE, α-Glucosidase, 15-LOX, and AChE in search for leads compounds. The most active analogues found through IC 50 values in μM against AChE were 7h (1.29 ± 1.24), 7c (2.58 ± 1.32) and 7i (5.62 ± 1.35) compared with the standard eserine (0.19 ± 0.05). Compound 7i (2.24 ± 1.80) of the synthesized analogue was found most active against BChE. Compounds against 15-LOX were 7i (2.07 ± 1.17) and 7e (2.12 ± 0.37) found even better than the standard quercetin (2.34 ± 0.35). Most of the synthesized analogues ( 7a , 7d-7j ) showed very excellent potential strength against α-Glucosidase even efficient than reference drug acarbose (38.25 ± 0.12) presented in Table 3. The in vitro results were confirmed by molecular docking investigations of the active ligands with the targeted enzymes. Bovine serum albumin (BSA) binding studies displayed how the ligands interacted with BSA. The data altogether predicts these molecules as leads in search for cholinesterase ( 7h, 7c, 7i ) and 15-LOX ( 7i ) enzymes. Further in vivo work is continued on targeted derivatives of 1,2,4- triazoles as inhibitors of therapeutically important enzymes.

Beyond one-fluid approximations for the thermodynamics of fluid mixtures

Developing analytic equations of state for fluid mixtures based on perturbation theories requires simplifying approximations, in which mixture properties are determined from effective pure component properties. While these one-fluid approximations reduce model complexity, they also introduce inaccuracies. In this work, a simple algebraic correction factor for perturbation theories applying a one-fluid approximation is proposed. The correction factor is defined as the ratio of the rigorous first-order perturbation term in Helmholtz energy to the respective first-order perturbation term in the one-fluid approximation. An approximate closed-form expression for the correction factor is derived in terms of the fundamental measures of the particles using symbolic regression. The new approach is thoroughly evaluated by applying it to a range of equations of state, including the uv-theory and the PCP-SAFT equation of state, to predict the thermodynamic properties of square-well, Lennard-Jones, and real-substance mixtures. New molecular simulation data for strongly size-asymmetric binary, ternary, and quinary Lennard-Jones mixtures are generated to test the proposed approach. Compared to the predictions obtained from a one-fluid approach, the correction factor significantly improves the accuracy of predicted phase equilibria and thermodynamic properties for model fluids. Its impact on real-fluid predictions with the PCP-SAFT equation of state is rather small, because PCP-SAFT segment size parameters of most substances are rather similar, whereas the correction factor primarily accounts for segment size asymmetry.

Exploring the effects and potential of unlocked I/O-powered single board computer clusters

Abstract Across all fields, experts strive to collect and analyze numerous data to extract meaningful insight. In response to this trend, Hadoop and Spark have emerged, and many organizations have adopted these platforms for big data storage and processing. In addition, data centers with powerful servers are constantly expanding to accommodate the increasing number of data, causing significant costs and environmental problems due to the tremendous energy consumption. Single board computer (SBC) clusters have emerged as a promising alternative for efficient computing. Most SBCs have adopted a microSD slot for data storage; thus effectively processing massive data has some limitations. However, the latest generation Raspberry Pi (RPi), model 5B provides a peripheral component interconnect express (PCIe) interface, enabling high-performance storage media, such as solid state drives (SSD). This paper extensively investigates the practicability and potential of SBCs for terabyte-scale big data processing. We build the SBC Hadoop cluster, adopting the most powerful, latest RPi 5B (8 GB of RAM) with a fast PCIe-based SSD via the PCIe interface, and perform six widely known benchmarks with a large (up to 2 TB) data size. Furthermore, this paper discusses challenges and suggestions, including the effects of input/output (I/O) throughput, central processing unit (CPU) overclocking, power supply, and trim command, which significantly affect SBC Hadoop performance. This comprehensive study concludes that integrating the enhanced computing of RPi 5B with unlocked I/O performance finally paves the way for a practical solution to real-world big data processing on SBC clusters.

GelInsight: Open-source software for large-sample DNA fragmentation quality control in gel electrophoresis images

High throughput DNA fragmentation technology for next generation sequencing have become widely available, but there remains a need for affordable and efficient DNA fragmentation pattern analysis. Commercial electrophoresis platforms, such as the TapeStation, are costly, time-consuming, and have limited batch-processing capabilities. Traditional gel electrophoresis provides a low-cost, high-throughput alternative. However, existing open-source software, such as ImageJ, for gel electrophoresis image analysis typically requires extensive manual pre-processing and yields limited quantitative metrics relevant to DNA fragmentation quality control. Here, we have developed an open-source MATLAB-based software, GelInsight , for bulk analysis of gel electrophoresis images for analysis and quality control of DNA fragmentation patterns. GelInsight integrates automated image and signal processing tools to determine the base pair size distribution of each sample and to calculate key quality control metrics, including multiple peak base pair sizes and base pair size percentage within a specified range. A user-friendly graphical user interface facilitates efficient data interaction and comprehensive visualization of the analytical outputs. The quantification accuracy of GelInsight , including peak base-pair accuracy and relative area measurements, is consistent with both existing open-source software (within 2 ± 2 bp) and commercial assays (within 64 ± 24 bp). Overall, this automated tool streamlines gel image analysis and enhances reproducibility and quantitative rigor in assessing DNA fragmentation patterns.

Whither BCH2? An <i>ab initio</i> inquiry

The boron methylene (BCH2) free radical has never been identified spectroscopically. We have undertaken a series of ab initio calculations to predict the molecular structures, vibrational frequencies, and energies of the ground and first three electronically excited states of BCH2 and its various isomers and isotopologues. In the ground state, we find that the global minimum is linear HBCH, with C2v BCH2 roughly 3935 cm−1 higher and the unstable CBH2 species is a C2v weakly bound structure at 16 384 cm−1, which readily isomerizes to the linear radical. HBCH and BCH2 are separated by a large isomerization barrier (12 825 cm−1), so it may be possible to prepare boron methylene in the gas phase and detect it with spectroscopic methods. The vibrational frequencies and rotational constants of four ground-state isotopologues of BCH2 have been calculated as an aid to future IR matrix isolation and gas-phase microwave studies. Similar calculations are reported for the ground-state linear HBCH species and its cis- and trans-bent excited states. The C̃2B2−X̃2A1 electronic transition in the 320–290 nm region is the only viable option for detecting BCH2 by gas-phase absorption or laser-induced fluorescence techniques. Franck–Condon simulations of the C̃−X̃ absorption and the allowed C̃−X̃ and C̃−B̃ emission transitions have been done for 11BCH2 and 11BCD2. In addition, the rotational structure expected for the 0-0 bands of both isotopologues under supersonic expansion conditions has been simulated. The ab initio data and predicted spectra should be invaluable for attempts to identify the boron methylene free radical in the gas phase.

Compartment-specific eccDNA patterns reveal senescence associated biomarkers in hUC-MSCs

Impact of exercise sequence in concurrent training on insulin resistance, glycemic control, and blood pressure in Type 2 diabetes

This study compared the effects of aerobic followed by resistance (CART) and resistance followed by aerobic (CRAT) training on insulin sensitivity, glycemic control, and blood pressure against a non-exercising control group (COT). 39 patients with type 2 diabetes were randomly assigned to CART (n = 13), CRAT (n = 13), or COT (n = 13) for a 12-week supervised program. Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) improved significantly (F = 24.460, p = 0.001, η² = 0.62), with CRAT showing a modestly greater reduction than CART (MD = 0.303, p = 0.022), while both training sequences produced greater improvements compared to COT (CART: MD = −0.493, p = 0.001; CRAT: MD = −0.796, p = 0.001). Fasting Blood Sugar (FBS) decreased significantly (F = 16.206, p = 0.001, η² = 0.519) in both CART (MD = −10.747, p = 0.001) and CRAT (MD = −11.459, p = 0.001) relative to COT, though no difference emerged between the two exercise sequences (MD = 0.712, NS). Systolic Blood Pressure (SBP) also declined in CART (MD = −4.896, p = 0.005) and CRAT (MD = −5.681, p = 0.001) compared with COT (F = 8.968, p = 0.001, η² = 0.374), again without a significant sequence effect (MD = 0.785, NS). No significant between-group changes were observed in Diastolic Blood Pressure (DBP). Overall, concurrent training effectively reduced insulin resistance, improved glycemic control, and lowered SBP in patients with type 2 diabetes. While CRAT offered a modest additional benefit for HOMA-IR, the findings suggest that concurrent training, regardless of sequence, provides meaningful clinical benefits for managing type 2 diabetes. Trial registrationPan African Clinical Trials Registry (PACTR202509591505325) pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=37070

Autoionizing excited states of N2 using complex-basis function spin-flip coupled cluster theory

Collision-induced autoionizing excited states play an important role in plasma formation through associative ionization, where excited states lie in resonance with the continuum. In this work, we compute the autoionization widths of various doubly excited states of the N2 molecule using equation-of-motion coupled-cluster theory combined with complex basis functions. This study represents the first application of spin-flip methods to doubly excited autoionizing states, enabled by a newly developed computational protocol based on Kaufmann basis functions. We apply this protocol to N2 and determine the widths of the Σg+3, 3–43Πu, and 23Δg states, which are potential contributors to the associative ionization process. Our results establish the complex basis function-based spin-flip method as a reliable and systematically improvable approach for resonance width calculations, opening avenues for its application to a broader class of autoionizing states in molecular systems.

Rhodamine B-assisted fluorescent aptasensor for the sensitive and selective assessment of Doxycycline hyclate in wastewater

Effect of exercise preconditioning on myocardial content of Sphingosine1-phosphate and its mechanism in rats after exhaustive exercise

Objective This study aimed to investigate the effects of exercise preconditioning on rat myocardial Sphingosine1-phosphate(S1P) content and its potential mechanisms of heart protection. Methods A rat model of exercise preconditioning followed by exhaustive exercise was established. Rats were randomized to four groups: control (C), exercise preconditioning (EP), EP plus the S1PR1-selective antagonist W146 (EP + W146), and EP plus the MEK1/2 inhibitor PD98059 (EP + PD98059). Following a final exhaustive swim, comparisons across groups revealed that EP attenuated myocardial injury and apoptosis, an effect which was abolished by both W146 and PD98059. Results 1. Exercise preconditioning (EP) significantly attenuated exhaustive exercise-induced myocardial injury and apoptosis ( P  &lt; 0.001); 2. EP significantly elevated myocardial S1P levels ( P  = 0.002), and S1PR1-selective antagonist (W146) abolished this cardioprotective effect ( P  = 0.016 for apoptosis); 3. Most importantly, MAPK pathway inhibition (PD98059) abrogated the protective effect of EP, as evidenced by significantly increased apoptosis ( P  = 0.002), despite unaltered S1P levels. Conclusion In summary, beyond confirming S1P elevation with exercise preconditioning, our findings propose the S1P→MAPK signaling axis as a novel mechanistic pathway warranting future validation.

Log-time algorithms for exact stochastic simulation of fully connected reaction networks using low-rank decomposition and rejection sampling

We show how to adapt and improve the stochastic simulation algorithm (SSA), also known as the Lanore–Gillespie algorithm, to exactly and efficiently simulate a large, fully connected network of chemical reactions. By combining a low-rank decomposition of an upper bound of the propensity matrix with rejection sampling, we are able to significantly reduce the time and memory costs of manipulating the reactions’ priority queues. The resulting algorithms exhibit logarithmic time and linear space complexity in the number of involved chemical species, outperforming the original SSA and subsequent stochastic methods on a benchmarking model. As a physical application, we simulate the time evolution of solute precipitation in a FeCu1.34% alloy under thermal aging. The substantial speed-up and significantly reduced memory consumption enable us to reach physical times and system sizes that were unattainable with previously employed deterministic and stochastic methods. The temporal evolution of the simulated sizes and number densities of Cu precipitates also matches very well with small-angle neutron scattering experiments.

Chelesta-8,24-dien-3-ol in Ficus exasperata leaves enhances the prevention of sodium nitrite-induced hypoxia by binding to HIF-1 and NF-κB

Birth preparedness and complication readiness knowledge, practices and its associated factors among recently delivered women: A cross-sectional study in Bharatpur, Chitwan, Nepal

Background Birth preparedness and complication readiness (BPCR) is a comprehensive strategy, aimed at ensuring that expectant mothers and their families are for normal delivery and preparing for potential complications that may arise during pregnancy, labor, delivery, and the postpartum period without any delays. BPCR interventions are widely promoted by government and international agencies to reduce maternal and neonatal health risk in developing countries like Nepal. Studying BPCR also helps identify gaps in knowledge, access, and practices, guiding interventions to strengthen health system and community awareness, especially in low-resource settings. Objective This study was conducted to assess birth preparedness and complication readiness knowledge, practices and its associated factors among recently delivered women in Bharatpur city, Chitwan, Nepal. Methods A community based cross-sectional study was conducted in 2022, on a sample of 220 recently delivered women. Data were collected using pre-tested structured interview questionnaire. The collected data were analyzed by IBM SPSS 20 version software. Variables with p-value ≤0.05 on the bivariate analysis were included in multivariate analysis. Adjusted odds ratios (AOR) with the respective 95% Confidence Interval (CI) and a p-value &lt;0.05 was used to set statistically significant variables in the multivariable analysis. Results Among 220 recently delivered women, majority (91.4%) of the women identified the place of delivery and saved money for childbirth (97.7%). Similarly, most of them arranged transportation (87.3%), identified a companion (85.9%), and arranged necessary materials (90%) for childbirth. Considerable (52.3%) women identified skilled birth attendants. Preparedness for blood donors (36.4%) found to be low as compared to other components. Overall, 46.8% of recently delivered women were well prepared. Family type, knowledge on components of BPCR, obstetric signs and symptoms and ANC visits were found to be statistically significant (p-value&lt;0.05) with birth preparedness practice. Associated characteristics were further subjected to multivariate logistic regression where knowledge on components of BPCR (AOR = 5.34,95%CI: (2.728–10.478) was found significantly associated with BPCR practice. Conclusion The overall 46.8% of women who prepared for birth and its complication readiness was found to be higher as compared to other reports. Encouraging women to utilize antenatal care, and such as sensitization of pregnant women, during ANC visit by the health workers, regarding components of BPCR, danger sign and symptoms during pregnancy, may enhance BPCR.

Selectivity in gas–liquid interactions: Molecular beam scattering of CD4 and ND3 from an aqueous flat liquid jet

The dynamics of polar and nonpolar molecules colliding with an aqueous surface are characterized by scattering molecular beams of deuterated methane and ammonia, CD4 and ND3 (Ei = 28.9 and 30.3 kJ mol−1, respectively), from a flat liquid jet of cold salty water (8 m LiBr, 230 K). Translational energy distributions of scattered species collected as a function of collision geometry probe both impulsive scattering (IS) and thermal desorption (TD) mechanisms. We find that CD4 scattering is dominated by IS and exhibits a super-specular angular distribution. The fraction of TD scattering events is notably smaller for cold salty water than for dodecane, consistent with a higher free energy of solvation for CD4 in the water jet. In contrast, no scattering signal is seen for ND3 from the water jet, a result attributed to the high solubility and efficient protonation of ND3 in liquid water. The IS channel for CD4 was analyzed using a soft-sphere model, yielding a higher internal energy (Eint) and lower effective surface mass (meff) than was seen for Ne/water; the higher value of Eint is attributed to rotational excitation of the scattered CD4. These findings demonstrate that the outcomes of a gas–liquid collision—scattering trajectory, surface adherence, and energy transfer—are directed at the molecular level by both the gaseous scatterer and liquid surface.

Visible-light Cr(VI) reduction on a CdS@MOF@C3N4 heterostructure via cascade S-scheme mechanism: a comprehensive study

Partial widths of shape resonances in pyridine and uracil using the stabilization method

Low-energy electron attachment to molecules often leads to the formation of shape resonances, which play a pivotal role in electron-driven chemical processes. While the total decay width of a resonance determines its auto-detachment lifetime, decomposing this width into partial contributions from various auto-detachment continuum channels may provide a deeper insight into the underlying decay dynamics. In this work, we explore the applicability of using bound state methods, in particular the analytic-continuation based stabilization method, for determining partial widths in medium-sized organic molecules. Angular momentum-resolved partial widths can be obtained by placing diffuse functions at the molecular center of mass. Using the stabilization method combined with the equation-of-motion electron attachment coupled cluster method, we applied this technique to pyridine and uracil, two prototypical π-conjugated systems, and analyzed the contributions of s-, p-, d-, f-, g-, h-, and i-type functions to the widths of shape resonances. Our results show that the dominant angular momentum component of each resonance width correlates strongly with the nodal structure of the corresponding resonant orbital. Importantly, we find that higher angular momentum functions, particularly d, f, g, and h, play a decisive role in accurately capturing resonance widths. Compared to conventional atom-centered augmentation schemes, the center of mass-based approach alleviates some of the uncertainties in the stabilization method associated with inconsistent avoided crossings.

Correction: Impact of crown and inlay size variations on the accuracy of various digital impression techniques

Modeling incoherent exciton transport between chlorosome tubes

Chlorosomes are the antennae of the efficient light harvesting complex in green (non-sulfur) bacteria. The ultrafast energy transfer process in natural light harvesting systems can be understood in terms of exciton transport. In chlorosomes, excitons can be delocalized over hundreds of molecules, making it of eminent interest to study large model systems composed of many (thousands) of molecules that are large enough to describe the exciton dynamics that occur in vivo in chlorosomes. In this study, we examine a recently developed Frenkel exciton Hamiltonian of a three coaxial tube chlorosome model based on an all-atom molecular dynamics simulation. We use the computationally efficient time domain Förster resonant energy transfer method to find the timescales of incoherent transfer between the chlorosome walls in this large model. We found that the population transfer rate between neighboring chlorosome walls is ∼2.3 ps−1. We used three different choices of initial quantum states for these transfer processes and found that this transfer timescale between neighboring walls does not vary significantly for these.