bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐contact thickness measurement with multilayer radiation structure
Authors: Haroune Feddal , Mohamed Tellache , Mohamed El Afendi , Junwu Tao
Published: September 2023

Microwaves have proven their efficiency in the thickness measurement field. However, in certain environments, the full accessibility to the measured samples is one big challenge; an illustration of these challenging environments is the ceramic thickness monitoring in aerospace industry. Since ceramic materials are known for their ability to support high pressure and high temperature, the control of their geometries and structures is of an utmost stature. In literature, several methods have been proposed to allow a non‐contact thickness measurement. One of the well‐known methods is based on waveguide open‐end radiation. Given the need of new accurate structures, a new model that takes into account the air gap between the sensor and the material under test is proposed. Accordingly, the study of multilayered dielectric composite is unavoidable. In this paper, a new multilayer thickness measurement structure using a coaxial waveguide probe is proposed. Moreover, an artificial neural networks algorithm which estimates and corrects the reflection coefficient shift caused by the air gap effect is implemented. Experimental results show that the estimation error of the system is less than 3% for Plexiglas and less than 2% for FR4. More results, with calibration techniques, validate the proposed measurement system.
Design of dual wideband bandpass filter using stub loaded multi‐mode resonators
Authors: Turkeli Alper , Gorur Ali Kursad , Sahin Elif Gunturkun , Gorur Adnan
Published: September 2023

In this paper, a novel dual wideband microstrip bandpass filter is proposed. The designed filter is constructed by two different stub loaded resonators located at the upper and bottom sides of the coupling line. The coupling transmission line is also connected to input and output (IO) ports. The upper resonator creates a wide passband, whereas the bottom resonator is used to create two transmission zeros in the passband. Thus, a wide passband can be divided into dual wide passbands. The bottom resonator is also utilized to improve the insertion and return losses in the passband. The designed filter is fabricated and tested in a very good agreement with the simulated results. The measured fractional bandwidths (FBWs) of the passbands are 44.6% and 24.2% at the center frequencies of 3.4 GHz and 5.51 GHz, respectively. The measured insertion losses in the passbands are 0.51 dB and 1.13 dB.
A high efficiency on‐chip reconfigurable Doherty power amplifier for LTE communication cells
Authors: Kumar Rajesh , Kanuajia Binod Kumar , Dwari Santanu , Kumar Sandeep , song Hanjung
Published: September 2023

In this paper, a high efficiency on‐chip reconfigurable Doherty power amplifier (DPA) with proposed topology is proposed for LTE or 4G communication cells. The proposed DPA consists of input driver topology, hybrid coupler, asymmetric amplifiers, and 1:1 balun filtered network. The proposed input driver circuit provides wide amplified signal operation within range of 2.3GHz to 6GHz with flat gain of 33 dB. The amplified signal is unsteadily divided into two paths toward the carrier and the power amplifier by 900 hybrid couplers and demonstrates 27.6 dB and 28.3 dB of gain along with 83.2% and 84.5% of power added efficiency at average output power of 40 dBm. The high efficiency and almost flatness in gain stability of proposed DPA providing better solution in order to overcome the interference and the broadband issues for LTE communication cells. The balun‐filtered network is employed for combined the two outputs of carrier and peak amplifiers that provides more uniform desired band of operation in the frequency responses. The proposed DPA circuit are implemented and optimized by using advanced design RF simulator platform. The fabricated chip is made by using 0.13 μm GaN HEMT on Si‐Nitride monolithic microwave integrated circuit die process. The fabricated chip of DPA provides 85% of PAE with 28 dB gain which are made close agreement with simulation results. The size of chip is 2.8*1.2mm2 which occupies less die area as compared to existing DPAs.
MFA‐ICPS: Semi‐supervised medical image segmentation with improved cross pseudo supervision and multi‐dimensional feature attention
Authors: Xia En , He Jianjun , Liao Zhangquan
Published: September 2023

Background

In the medical field, medical image segmentation plays a pivotal role in facilitating disease evaluation and supporting treatment decision‐making for doctors. Recently, deep learning methods have been employed in the field of medical image segmentation. However, the manual annotation of a large number of reliable labels is a costly and time‐consuming process.

Purpose

To address this challenge, a semi‐supervised learning framework is required to alleviate the burden of reliable labeling and enhance segmentation accuracy in challenging areas of medical images.

Methods

Therefore, this paper presents MFA‐ICPS framework, a semi‐supervised learning framework based on the improved cross pseudo supervision (ICPS) and multi‐dimensional feature attention (MFA) modules. Medical images inevitably contain some noise that may affect the segmentation accuracy, so the proposed framework addresses this challenge by introducing noise disturbance, combining ICPS and MFA modules, and using pseudo‐segmentation maps and MFA maps to maintain the consistency at both the output and feature levels.

Results

In the experiments, MFA‐ICPS framework accurately obtains the following performances on the left atrial dataset: Dice, Jaccard, 95HD, and ASD values are , , 6.00 and 1.94 mm, respectively. And on the pancreas‐CT dataset, the following performances are accurately obtained: Dice, Jaccard, 95HD, and ASD values are , , 7.67 and 1.65 mm, respectively.

Conclusions

The segmentation performance of MFA‐ICPS framework on different medical datasets demonstrates its remarkable capability to significantly enhance medical image segmentation.
Bounds for joint probabilities of multistate systems using preservation of log‐concavity
Authors: Sabnis Sanjeev , Majumder Priyanka , Ghosh Shyamal
Published: September 2023

Log‐concavity of multivariate distributions is an important concept in general and has a very special place in the field of Reliability Theory. An attempt has been made in this paper to study preservation results for (i) the discrete version of multivariate log‐concavity for multistate series and multistate parallel systems consisting of independent components, states of both components and systems being represented by elements in a subset of and (ii) the continuous version of multivariate log‐concavity under multistate series and multistate parallel systems made up of independent components and states of both, systems and components, taking values in the set . These results for discrete and continuous versions of log‐concavity have also been extended to systems that are formed using both multistate series and multistate‐parallel systems. Further, the results in (ii) have been used to obtain important and useful bounds on joint probabilities related to times spent by multistate components, multistate series, multistate parallel systems, and the combinations thereof.
Educational strategies and nursing theory to prepare leaners for NCLEX‐RN
Authors: Almasloukh Khalid Bandar , Miner Melissa , Phillips Kathleen , Evans Michael
Published: September 2023

Aim

To identify teaching stategies, theories, and methods to enhance students' quality of life (QOL) that are used in preparing students for the NCLEX‐RN exam.

Design

A scoping review was conducted.

Methods

Arksey and O'Malley's methodological framework and PRISMA‐ScR guidelines were utilized. Data were derived from four databases including CINAHL, ERIC, PsychINFO and Web of Science using specific keywords. Inclusion criteria were English language and articles published in the last 7 years.

Results

Studies (N = 25) revealed that multiple educational strategies are used to prepare students for the NCLEX‐RN exam; however, there was not a consensus on a best practice. Eight theories were utilized in more than one article. QOL concerns of psychological, social, spiritual, financial and occupational dimensions may relate to the NCLEX‐RN results.

Public Contribution

Patterns in educational strategies and theories were noted among articles, but there was no focus on enhancing students' QOL.
Cyclohexene‐Embedded Dicyanomethylene Merocyanines – Consecutive Three‐Component Coupling‐Addition Synthesis and Chromophore Characteristics
Authors: Papadopoulos Julian , Reiss Guido J. , Mayer Bernhard , Müller Thomas J. J.
Published: September 2023

A concise and efficient consecutive three‐component alkynylation‐addition synthesis of cyclohexene‐embedded dicyanomethylene merocyanines furnishes a small library of dyes in moderate to excellent yield. The dyes possess strong absorption coefficients of the longest wavelength absorption bands. According to the crystal structure, the small bond length alternations account for a highly delocalized electronic ground state. The electronic structure of the absorption bands is qualitatively rationalized by TDDFT calculations, which explain that intense HOMO‐LUMO transitions along the merocyanine axis lead to cyanine similar Stokes shifts.
PD‐L1 and PD‐1 expression in pediatric post‐transplant Burkitt lymphoma and other monomorphic post‐transplant lymphoproliferative disorders
Authors: Geerlinks Ashley V. , Allen Upton , Ngan Bo‐Yee , Punnett Angela
Published: September 2023

Background

Post‐transplant lymphoproliferative disorders (PTLD) develop as a consequence of immune suppression. Programmed death protein 1 (PD‐1), a regulator of host immune activation, binds to programmed death‐ligand 1 (PD‐L1) to suppress the T‐cell immune response. PD‐1/PD‐L1 pathway may play a role in PTLD. The objective was to describe intratumoral expression of PD‐L1 and PD‐1 in pediatric monomorphic PTLD, and assess if density of these cells is associated with progression‐free survival (PFS) and overall survival (OS).

Procedure

Clinical variables and outcome data were collected on B‐cell monomorphic PTLD treated in Toronto, Canada between 2000 and 2017. Diagnostic area from tumor tissue was identified to count CD3‐positive or PD‐1‐positive cells and CD3‐negative lymphoma B cells or PD‐L1‐positive cells. CD3+, PD‐1+, and PD‐L1+ cell densities were compared between cases of PTLD. OS and PFS were analyzed.

Results

We identified 25 cases of B‐cell monomorphic PTLD; majority Burkitt lymphoma (32%) and diffuse large B‐cell lymphoma (56%). All cases had CD3+ cells infiltrating the tumor, and median percentage of CD3+ cells was 14% (interquartile range: 6.2%–25%). Twelve cases (48%) had PD‐1+ cell infiltrating (range: 1%–83%) and 13 cases (52%) had no PD‐1+ cells infiltrating. Sixteen cases (64%) had PD‐L1+ cells present; however, there was no PD‐L1 expression on any Burkitt lymphoma tissue. When comparing PD‐1 and PD‐L1 expression, there was no difference in OS or PFS.

Conclusion

Intratumoral presence of PD‐1+ and PD‐L1+ cells varied in pediatric patients with monomorphic PTLD; however, no relationship to OS and PFS was identified.
Altered liver function test after Covid‐19 vaccines: A retrospective control group study
Authors: Jabif Fernando Ezequiel , Vallone Marcelo Gabriel , Stanek Vanina Cecilia , Lopez Marlene Padilla , Sobenko Natalia , Villamil Alejandra Maria , Ratti Maria Florencia Grande
Published: September 2023

Background and Purpose

Liver injury after Covid‐19 vaccine has been described, although the incidence was not well established. We aimed to compare cumulative incidence of new onset liver test alteration after Covid‐19 vaccination, and to compare with an historical control of influenza vaccination.

Methods

We conducted a retrospective cohort study which included adults who received at least one dose of Covid‐19 vaccine from January 1 to May 30, 2021 and a control group who received a single dose of influenza vaccine during 2019, in a tertiary medical center from Argentina.

Results

We included 29 798 patients in Covid‐19 vaccine group and 24 605 in influenza vaccine group. Liver function tests were performed in 7833 (26.9%) in Covid‐19 vaccine group and 8459 (34.37%) in influenza vaccine group. Cumulative incidence at 90 days of new onset liver enzyme test alteration was 4.7 per 1000 (95% 4.0–5.5) for Covid‐19 group, and 5.1 per 1000 (95% 4.3–6.1) for the influenza vaccine group (p value = 0.489). Two patients in the Covid‐19 vaccine group developed immune mediated liver injury.

Conclusions

We found no difference in liver test alteration between groups. These findings support the safety of Covid‐19 vaccines. While we have identified two cases that are consistent with immune mediated liver injury following COVID‐19 vaccination, we believe that the available data is insufficient to attribute them solely to the vaccination.
Mechanistic modeling projections of antibody persistence after homologous booster regimens of COVID‐19 vaccine Ad26.COV2.S in humans
Authors: Dari Anna , Jacqmin Philippe , Iwaki Yuki , Neyens Martine , Le Gars Mathieu , Sadoff Jerald , Hardt Karin , Ruiz‐Guiñazú Javier , Pérez‐Ruixo Juan José
Published: September 2023

Mechanistic model‐based simulations can be deployed to project the persistence of humoral immune response following vaccination. We used this approach to project the antibody persistence through 24 months from the data pooled across five clinical trials in severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2)‐seronegative participants following vaccination with Ad26.COV2.S (5 × 1010 viral particles), given either as a single‐dose or a homologous booster regimen at an interval of 2, 3, or 6 months. Antibody persistence was quantified as the percentage of participants with detectable anti‐spike binding and wild‐type virus neutralizing antibodies. The projected overall 24‐month persistence after single‐dose Ad26.COV2.S was 70.5% for binding antibodies and 55.2% for neutralizing antibodies, and increased after any homologous booster regimen to greater than or equal to 89.9% for binding and greater than or equal to 80.0% for neutralizing antibodies. The estimated model parameters quantifying the rates of antibody production attributed to short‐lived and long‐lived plasma cells decreased with increasing age, whereas the rate of antibody production mediated by long‐lived plasma cells was higher in women relative to men. Accordingly, a more pronounced waning of antibody responses was predicted in men aged greater than or equal to 60 years and was markedly attenuated following any homologous boosting regimen. The findings suggest that homologous boosting might be a viable strategy for maintaining protective effects of Ad26.COV2.S for up to 24 months following prime vaccination. The estimation of mechanistic modeling parameters identified the long‐lived plasma cell pathway as a key contributor mediating antibody persistence following single‐dose and homologous booster vaccination with Ad26.COV2.S in different subgroups of recipients stratified by age and sex.
Dielectric Relaxation Behavior and Electrical Conduction Mechanism of PVA/ZnO Nanocomposites for Flexible Electronic Device Application
Authors: Chanu Toijam Suma , Singh Kshetrimayum Jugeshwar , Singh Wahengbam Joychandra , Devi Kongkham Nomita
Published: September 2023

Transport properties of polyvinyl alcohol/ZnO nanocomposites (PVA/ZnO) of varying ZnO nanofiller are studied focussing on their potential application in electronic device application. The structural, morphological, and elemental composition studies of the prepared samples are done by X‐ray diffraction (XRD), scanning electron microscope (SEM), and energy‐dispersive X‐ray analysis (EDX). XRD confirms the formation of nanocomposites. SEM image shows the dispersion of ZnO nanoparticles on the surface of PVA matrix. EDX verifies that no external impurities are present in the nanocomposite samples. Frequency‐ and temperature‐dependent dielectric measurement of the samples reveals maximum dielectric constant at PVA/15 wt% ZnO nanocomposite. Dielectric loss results show a lossless behavior at higher frequencies (<0.2), indicating their suitability for high‐frequency applications. The AC conductivity studies reveal that electrical conduction mechanism in the nanocomposites is governed by the correlated barrier hopping mechanism. Activation energy of the samples reveals the presence of two thermally activated transport mechanism above and below 353 K. The imaginary part of electric modulus with frequency shows a single relaxation peak indicating the transition from long‐range to short‐range mobility with increasing frequency and temperature above 353 K. The contribution of grain and grain boundary in the electrical conduction process is confirmed from the Nyquist plot.
Addressing the rights and well‐being of domestic workers in Africa: Status in Malawi
Authors: Nayupe Symon Fidelis , Touray Alieu , Tembo Dalitso , Msiska Mama Tamanda , Mputeni Juliana , Muhome Allan Hans
Published: September 2023

Domestic work continues to contribute to employment in most developing countries significantly. Over 75.6 million people are domestic workers worldwide, three‐quarters of whom are women. In Africa, many people still rely on domestic work for employment, making up 2.2% of the total workforce on the continent. With a predominant presence in the sub‐Saharan region, Africa's domestic workforce is estimated at around 9.6 million. Mirroring the global trend, most workers are women, with an estimated 15.8% of Africa's paid female employees being domestic workers. This considerable presence of domestic work contributes to domestic and intra‐continental migration in Africa, where about 80% of the domestic workers are from within. The Southern African region is a major intra‐continent destination for most workers. In Malawi, domestic labour is also common and is one of the country's primary sources of jobs, especially for poor populations who often domestically migrate from rural to urban areas. However, country estimates for the total number of domestic workers are yet to be published. Although there have been improved work conditions for domestic workers in some countries worldwide, the situation is different in many African nations, including Malawi. Domestic workers still face underpayment, long working hours, physical and psychological ill‐treatment from employers, challenging, harsh working environments and lack of access to healthcare. We discuss the status of the well‐being of domestic workers in Malawi, a country in southeastern Africa. We note that the working conditions for domestic workers continue to be unfavourable, with physical and psychological abuse and other human rights violations. To improve the well‐being and working conditions of domestic workers, government and non‐governmental organisations should, among other things, facilitate programmes to root out poverty, strengthen the legal framework that addresses domestic worker abuse and ensure social protection, including healthcare protection.
Optimization of degree of conformance for multi‐response systems considering model imprecision: A data‐driven metaheuristic approach
Authors: Hejazi Taha‐Hossein
Published: September 2023

Quality‐based design optimization is a process consisting of factor identification, finding an empirical/physical model between responses and factors, and finding a factor setting leading to the best quality levels. Response surface methodology is a well‐grounded data‐driven approach that applies a collection of statistical‐mathematical techniques to achieve the design requirements. Today's complex systems are usually affected by nuisance factors and have more than one output characteristic with some degree of correlation. This study aims to develop two‐stage stochastic programming for a multi‐response optimization model based on the degree of conformance as the most comprehensive metric for such design problems. The proposed approach can include the model imprecision in the optimization procedure using the probabilistic properties of the estimated parameters. This method would be applied in highly sensitive processes or costly operations that require a more accurate setting to avoid extra reworks or scraps. A simulated annealing algorithm with a boosted scenario checking modification has been applied to cope with the expensive computations for problem instances with a large sample size of uncertain parameters. The proposed model has also analyzed two cases from the literature, and the results support its superiority compared to the existing approaches.
Effect of flow regulation on streambank erosion: A perspective downstream of a flood control dam, Kansas, USA
Authors: Bigham Kari A. , Keane Tim D. , Moore Trisha L.
Published: September 2023

While large dams provide society with many benefits, there are many environmental trade‐offs. One trade‐off of dam installation is the morphologic changes that ensue in the downstream channel. Channel widening due to streambank erosion is a common response to flow regulation (FR), but dominant erosion processes and rates have rarely been evaluated downstream of dams. This case study investigates how a 75‐year‐old flood control dam has affected downstream bank erosion on the Lower Smoky Hill River, located in central Kansas, USA. A one‐dimensional hydraulic, sediment transport, and bank erosion model was used to assess changes in erosion processes and rates with and without FR up to 86 river km downstream of the dam. The model showed that toe erosion was the dominant bank erosion process for both with and without FR scenarios. While toe erosion rates were significantly higher (α < 0.05) under the without FR scenario, more days of toe erosion occurred under the with FR scenario. More days of toe erosion are attributed to the change in the flow regime, with moderate flows (between 5% and 40% daily exceedance probability) increasing and hydrograph rise and fall rates decreasing since dam installation. Furthermore, it was observed that pioneer riparian vegetation may drown out during long duration, high‐flow events brought on by FR, amplifying erosion rates. These results provide broader insight into morphological responses to flood control dams, highlighting the effect changes in flow regime can have on downstream channel morphology and identifying major challenges in managing streambank erosion downstream of dams.
On difference‐based gradient estimation in nonparametric regression
Authors: Zhang Maoyu , Dai Wenlin
Published: September 2023

We propose a framework to directly estimate the gradient in multivariate nonparametric regression models that bypasses fitting the regression function. Specifically, we construct the estimator as a linear combination of adjacent observations with the coefficients from a vector‐valued difference sequence, so it is more flexible than existing methods. Under the equidistant designs, closed‐form solutions of the optimal sequences are derived by minimizing the estimation variance, with the estimation bias well controlled. We derive the theoretical properties of the estimators and show that they achieve the optimal convergence rate. Further, we propose a data‐driven tuning parameter‐selection criterion for practical implementation. The effectiveness of our estimators is validated via simulation studies and a real data application.
A Bayesian framework for pathway‐guided identification of cancer subgroups by integrating multiple types of genomic data
Authors: Sun Zequn , Chung Dongjun , Neelon Brian , Millar‐Wilson Andrew , Ethier Stephen P. , Xiao Feifei , Zheng Yinan , Wallace Kristin , Hardiman Gary
Published: September 2023

In recent years, comprehensive cancer genomics platforms, such as The Cancer Genome Atlas (TCGA), provide access to an enormous amount of high throughput genomic datasets for each patient, including gene expression, DNA copy number alterations, DNA methylation, and somatic mutation. While the integration of these multi‐omics datasets has the potential to provide novel insights that can lead to personalized medicine, most existing approaches only focus on gene‐level analysis and lack the ability to facilitate biological findings at the pathway‐level. In this article, we propose Bayes‐InGRiD (Bayesian Integrative Genomics Robust iDentification of cancer subgroups), a novel pathway‐guided Bayesian sparse latent factor model for the simultaneous identification of cancer patient subgroups (clustering) and key molecular features (variable selection) within a unified framework, based on the joint analysis of continuous, binary, and count data. By utilizing pathway (gene set) information, Bayes‐InGRiD does not only enhance the accuracy and robustness of cancer patient subgroup and key molecular feature identification, but also promotes biological understanding and interpretation. Finally, to facilitate an efficient posterior sampling, an alternative Gibbs sampler for logistic and negative binomial models is proposed using Pólya‐Gamma mixtures of normal to represent latent variables for binary and count data, which yields a conditionally Gaussian representation of the posterior. The R package “INGRID” implementing the proposed approach is currently available in our research group GitHub webpage (https://dongjunchung.github.io/INGRID/).
Surface Morphologies and Wettability Studies of pH‐Sensitive Nanofibrillated Membranes
Authors: Liu Hsuan‐Hung , Chin Wei‐Kuo
Published: September 2023

The pH‐sensitive membranes have been extensively used in various fields. Through the incorporation of specific functional groups on pH‐sensitive molecules, diverse surface energies and degrees of wettability can be achieved at different pH values. In this study, we transformed pH‐sensitive copolymers into nanofibrillated membranes to increase their sensitivity to pH in terms of the contact angle formed by liquid droplets on their surface. Because N,N‐dimethylaminoethyl methacrylate (DMAEMA) contains an amino group, it is sensitive to acidic and alkaline environments. Moreover, to enhance the functionality, we selected styrene and methyl methacrylate (MMA) for random copolymerization with DMAEMA. We then used anodized aluminum oxide (AAO) templates to process the two copolymers into biomimetic fibrillated membranes. The contact angles between various‐pH aqueous droplets and different membranes were measured. Our results indicated that when the droplets were alkaline, the contact angle on the nanofibrillated membranes was large. When the pH of the droplets was decreased, the contact angle also decreased. In addition, the membranes were found to be reusable after being tested, washed, and dried. The surface free energy of nanofibrillated membranes with different molar feed ratios was also investigated in this study by using the model of Owens, Wendt, Rabel and Kaelble.
Metal‐Free Ring‐Opening of Epoxides
Authors: Kumar Vikas , Chimni Swapandeep Singh
Published: September 2023

Epoxide ring is considered as an efficient structural toolbox to access 1,2‐difunctionalised compounds. Epoxide precursors are highly susceptible towards nucleophiles owing to its inherent ring strain. Metal free methodologies for epoxides ring opening with various nucleophiles provide an easy, economic and sustainable access to synthetically and biologically important 1,2‐difunctionalized compounds without harming the environment. This article highlights step by step development of various strategies for the ring opening of epoxides without the use of metal from last two decades. Use of water, ionic liquids, cyclodextrins and organocatalyts for the ring opening reactions of epoxide have been discussed in detail.
Synthesis and Biological Evaluation of Benzoxazolone−Thiosemicarbazide, 1,2,4‐Triazole, 1,3,4‐Thiadiazole Derivatives as Cholinesterase Inhibitors
Authors: Koçak Aslan Ebru , Sağlık Begüm Nurpelin , Özkay Yusuf , Palaska Erhan
Published: September 2023

In this study, a new series of benzoxazolone−thiosemicarbazide/1,2,4‐triazole/1,3,4‐thiadiazole hybrids were designed and synthesized. The structures of novel compounds were elucidated by spectral methods (IR, 1H‐NMR, 13C‐NMR, ESI‐MS) and elemental analyses. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activity of the compounds were investigated using in vitro Ellman method using donepezil and tacrin as the standards. Although none of compounds showed significant inhibitor activity on BuChE, compounds 2 c, 3 a, 4 a and 5 b displayed good inhibitory activities on AChE with IC50 values of 0.031, 0.049, 0.117 and 0.085 μg/mL, respectively. Molecular docking studies were carried out performed to the interactions with the active site of the enzyme (PDB:4EY7) and enzyme kinetics studies were performed for the most potent AChE inhibitor compound 2 c.
Surfactant‐Mediated Synthesis of Methylene Bridged 6‐Aminouracils: Development of a Greener Protocol, Water Remediation and Preliminary Biological Screening
Authors: Mal Susital , Das Subrata
Published: September 2023

Herein, we describe a surfactant‐catalyzed green methodology for electrophilic substitution reaction of 6‐aminouracil derivatives with various aldehydes that were neither reported earlier nor produced using conventional routes. Optimized results show the importance of anionic surfactant (SDS) on the reaction between hydrophilic and hydrophobic compounds in aqueous medium. All synthesized compounds were characterized by various spectroscopic methods like FTIR, NMR, HRMS, and SC‐XRD. Furthermore, the surfactant remediation from the reaction mixture was done using graphene oxide (GO). The results from batch‐adsorption studies indicate prominent sorption of SDS onto the surface of GO with an adsorption efficiency of ~84.9 %. The SDS adsorbed onto GO were analyzed using UV‐vis, FT‐IR, Raman, and HRTEM analysis. Next, the synthesized compounds were screened for their potential anti‐SARS‐CoV2 activity due to their structural resemblance with pyrimidine analogs acting as anti‐viral agents. The in‐silico results indicate that the synthesized compounds exhibit the highest inhibitory activity towards RdRp with binding energy −9.55 kcal/mol. In contrast, Remdesivir showed only −6.45 kcal/mol. In addition, upon preliminary screening of the compounds for possible antimicrobial activity (antifungal and anti‐leishmanial), 4 bf showed moderately high inhibitory activity with IC50 values of 205.48 μM and 124.97 μM for fungal and leishmanial strains, respectively.
Antioxidant Activity, Molecular Docking and Quantum Studies of New Bis‐Schiff Bases Based on Benzyl Phenyl Ketone Moiety
Authors: Ahmad Rashid , Alam Aftab , Khan Momin , Ali Tahseen , Elhenawy Ahmed A. , Ahmad Manzoor
Published: September 2023

In the current research work novel bis‐Schiff base products of benzyl phenyl ketone nucleus were synthesized via two step reactions in excellent yields. Using FTIR, EI‐MS and 1H‐NMR spectroscopic procedures, the structures of synthesized derivatives were confirmed and finally evaluated them for DPPH free radical scavenging activity. In the synthetic series, compounds 2 c (IC50=26.11±0.12 μM), 2 b (IC50=30.33±0.22 μM), 2 d (IC50=38.19±0.65 μM), and 2 a (IC50=40.12±0.42 μM) exhibited excellent activity better than standard drug ascorbic acid (IC50=44.01±1.41 μM) while the rest of derivatives revealed good to moderate activity. Frontier molecular orbitals, like HOMO and LUMO, which show charge transfer from molecule to biological transfer, and MEP maps, which show the chemically reactive zone suited for drug action, are calculated using DFT study. Non bonding orbitals (NBO), the electron localization function (ELF) and atoms in molecule (AIM) charges is also calculated. Strong hydrogen bonding interactions with crucial amino acid residues of the peroxidase structure are revealed by the molecular docking analysis of the drug with DPPH for efficient inhibition.
Structural Features, Emission Analysis, and Covalency Comparison of Neodymium Acylpyrazolone Complexes using Oscillator Strengths, Covalency and Judd‐Ofelt Parameters**
Authors: Travadi Maitrey , Jadeja Rajendrasinh N. , Butcher Ray J.
Published: September 2023

Three distorted square antiprismatic eight coordinated neodymium acylpyrazolone complexes were synthesized having the compositions [Nd(L1)3(H2O)(EtOH)] (NdL1), [Nd(L2)3(H2O)(EtOH)] (NdL2), and [Nd(L3)3(H2O)(EtOH)] (NdL3). The structure of all three complexes was examined using ESI‐mass, FT‐IR, and thermogravimetric methods. According to the single crystal analysis of NdL1, the complex was found eight‐coordinated (NdO8) with a distorted square antiprismatic geometry. A powder XRD pattern confirmed a similar structural arrangement of the other two complexes. In electronic absorption spectra, the transition 4G5/2←4I9/2, which is close to the centre of the visible spectrum (~17,500 cm−1), exhibits hypersensitivity, which stands out in stark contrast to the behaviour of many other typically weak and reliably unchanging, typical 4f–4f transitions. Through a comparative analysis of calculated oscillator strength, Judd‐Ofelt parameters, root mean square deviation, radiative lifetime and covalency parameters in various solvents, hypersensitivity, symmetry characteristics, and covalency have been thoroughly investigated. The promotion of 4f–4f electric‐dipole intensity has been found to be particularly successful with ethanol, pyridine, DMF, and DMSO. Utilizing Judd‐Ofelt Ω4 values and Hirshfeld analysis, long‐range secondary π⋅⋅⋅π stacking or H‐bonding interactions were investigated. The intensity of emission spectra, quantum yield, stokes shift, and antenna effect energy diagram was examined using solid‐state emission spectra.
Synthesis of Gluco‐Alkynones via a Carbonylative Coupling Reaction Using 1‐Iodoglucal
Authors: Paschoalin Caio , Toledo Mônica F. Z. J. , Veríssimo Dayane , Hornink Milene M. , Pimenta Daniel C. , Stefani Hélio A.
Published: September 2023

Herein, we report a simple and efficient synthesis of gluco‐alkynones obtained through the carbonylative coupling reaction of 1‐iodoglucal, catalyzed by palladium. A broad range of gluco‐alkynones were prepared with various aromatic aryl‐ and heteroaryl‐substituted alkynes. The reaction proved to be limiting for alkyl and propargyl acetylenes. Reactions occur within short times and in moderate to excellent yields.
Manganese Amplifies Photoinduced ROS in Toluidine Blue Carbon Dots to Boost MRI Guided Chemo/Photodynamic Therapy
Authors: Chu Dongchuan , Qu Hang , Huang Xueping , Shi Yu , Li Ke , Lin Wenzheng , Xu Zhuobin , Li Dandan , Chen Hao , Gao Lizeng , Wang Wei , Wang Huihui
Published: September 2023

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn‐CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials. As expected, the enhanced magnetic resonance (MR) imaging capability of Mn‐CDs is realized in response to the TME (acidity and glutathione), and r1 and r2 relaxation rates are enhanced by 224% and 249%, respectively. In addition, the photostability of Mn‐CDs is also improved, and show an efficient singlet oxygen (1O2) yield of 1.68. Moreover, Mn‐CDs can also perform high‐efficiency peroxidase (POD)‐like activity and catalyze hydrogen peroxide to hydroxyl radicals, which is greatly improved under the light condition. The results both in vitro and in vivo demonstrate that the Mn‐CDs are able to achieve real‐time MR imaging of TME responsiveness through aggregation of the enhanced permeability and retention effect at tumor sites and facilitate light‐enhanced chemodynamic and photodynamic combination therapies. This work opens a new perspective in terms of the role of carbon nanomaterials in integrated diagnosis and treatment of diseases.
Effect of Secondary Heat Treatment after a Washing on the Electrochemical Performance of Co‐Free LiNi0.975Al0.025O2 Cathodes for Li‐Ion Batteries
Authors: Välikangas Juho , Laine Petteri , Hu Tao , Tynjälä Pekka , Selent Marcin , Molaiyan Palanivel , Jürgen Kahr , Lassi Ulla
Published: September 2023

The steadily growing electric vehicle market is a driving force in low‐cost, high‐energy‐density lithium‐ion battery development. To meet this demand, LiNi0.975Al0.025O2 (LNA), a high‐energy‐density and cobalt‐free cathode material, has been developed using a low‐cost and efficient co‐precipitation and lithiation process. This article explores how further processing (i.e., washing residual lithium from the secondary particle surface and applying a secondary heat treatment at 650 °C) changes the chemical environment of the surface and the electrochemical performance of the LNA cathode material. After washing, a nonconductive nickel oxide (NiO) phase is formed on the surface, decreasing the initial capacity in electrochemical tests, and suppressing high‐voltage (H2) to (H3) phase transition results in enhanced cycle properties. Furthermore, the secondary heat treatment re‐lithiates surface NiO back to LNAand increases the initial capacity with enhanced cycle properties. Electrochemical tests are performed with the cells without tap charge to suppress the H2 to H3 phase transition. Results reveal that avoiding charging cells at a high voltage for a long time dramatically improves LNA's cycle life. In addition, the gas analysis tests performed during charge and discharge to reveal how the amount of residual lithium compounds on the surface affects gas formation are studied.
Glucosylated Hybrid TiO2/Polymer Nanomaterials for Actively Targeted Sonodynamic Therapy of Cancer
Authors: Zlotver Ivan , Sosnik Alejandro
Published: September 2023

Sonodynamic therapy (SDT) is an anti‐cancer therapeutic strategy based on the generation of reactive oxygen species (ROS) upon local ultrasound (US) irradiation of sono‐responsive molecules or nanomaterials that accumulate in the tumor. In this work, the sonodynamic efficiency of sono‐responsive hybrid nanomaterials composed of amorphous titanium dioxide and an amphiphilic poly(ethylene oxide)‐b‐poly(propylene oxide) block copolymer is synthesized, fully characterized, and investigated both in vitro and in vivo. The modular and versatile synthetic pathway enables the control of the nanoparticle size between 30 and 300 nm (dynamic light scattering) and glucosylation of the surface for active targeting of tumors overexpressing glucose transporters. Studies on 2D and 3D rhabdomyosarcoma cell cultures reveal a statistically significant increase in the sonodynamic efficiency of glucosylated hybrid nanoparticles with respect to unmodified ones. Using a xenograft rhabdomyosarcoma murine model, it is demonstrated that by tuning the nanoparticle size and surface features, the tumor accumulation is increased by ten times compared to main off‐target clearance organs such as the liver. Finally, the SDT of rhabdomyosarcoma‐bearing mice is investigated with 50‐nm glucosylated nanoparticles. Findings evidence a dramatic prolongation of the animal survival and tumor volumes 100 times smaller than those treated only with ultrasound or nanoparticles.
A Self‐Adaptive and Regenerable Hydrogel Interfacial Evaporator with Adjustable Evaporation Area for Solar Water Purification
Authors: Liu Yue , Tian Ye , Liu Na , Zhao Shuaiheng , Zhai Huajun , Ji Jiujiang , Cao Wenqing , Tao Lei , Wei Yen , Feng Lin
Published: September 2023

Solar‐driven interfacial evaporation is a potential water purification solution. Here, a novel regenerable hydrogel interfacial evaporator is designed with tunable water production. Such an evaporator is fabricated by readily mixing hydroxypropyl chitosan (HPCS) and dibenzaldehyde‐functional poly(ethylene glycol) (DF‐PEG) at ambient conditions. Dynamic Schiff base bonds bestow on the HPCS/DF‐PEG hydrogel (HDH) evaporator self‐adaptivity and pH responsiveness. The as‐prepared HDH is enabled to spontaneously change shape to adapt to different molds, endowing the evaporator with adjustable evaporation area. The water production performance of the intelligent evaporator is first evaluated using tunable evaporation index (TEI, the tunable evaporated water mass per hour), which can be altered from 0 kg h−1 to 3.21 kg h−1 under one sun. Besides, the large‐scale evaporator can be expediently fabricated by virtue of the self‐adaptivity. Benefiting from the pH responsiveness, the HDH evaporator is successfully regenerated with the removal of organic dye by the liquefaction‐dialysis‐regeneration operations. Meanwhile, the re‐created evaporator maintains the self‐adaptive characteristic and almost constant water evaporation rate compared to that of the initial evaporator. Therefore, this distinctive concept provides a facile strategy to develop smart and recyclable solar‐driven interfacial evaporators for flexible water purification.
Revealing a Double‐Volcano‐Like Structure‐Activity Relationship for Substitution‐Functionalized Metal‐Phthalocyanine Catalysts toward Electrochemical CO2 Reduction
Authors: Zhu Weiwei , Liu Suqin , Zhao Kuangmin , Ye Guanying , Huang Kui , He Zhen
Published: September 2023

Electron‐donating/‐withdrawing groups (EDGs/EWGs) substitution is widely used to regulate the catalytic performance of transition‐metal phthalocyanine (MPc) toward electrochemical CO2 reduction, but the corresponding structure‐activity relationships and regulation mechanisms are still ambiguous. Herein, by investigating a series of substitution‐functionalized MPc (MPc‐X), this work reveals a double‐volcano‐like relationship between the electron‐donating/‐withdrawing abilities of the substituents and the catalytic activities of MPc‐X. The weak‐EDG/‐EWG substitution enhances whereas the strong‐EDG/‐EWG substitution mostly lowers the CO selectivity of MPc. Experimental and calculation results demonstrate that the electronic properties of the substituents influence the symmetry and energy of the highest occupied molecular orbitals of MPc‐X, which in turn determine the CO2 adsorption/activation and lead to diverse CO2 reduction pathways on the EWG or EDG substituted MPc via different CO2 adsorption modes. This work provides mechanism insights that could be guidance for the design and regulation of molecular catalysts.
Electron Transport Layer Engineering Induced Carrier Dynamics Optimization for Efficient Cd‐Free Sb2Se3 Thin‐Film Solar Cells
Authors: Luo Ping , Imran Tahir , Ren Dong‐Lou , Zhao Jun , Wu Ke‐Wen , Zeng Yu‐Jia , Su Zheng‐Hua , Fan Ping , Zhang Xiang‐Hua , Liang Guang‐Xing , Chen Shuo
Published: September 2023

Antimony selenide (Sb2Se3) is a highly promising photovoltaic material thanks to its outstanding optoelectronic properties, as well as its cost‐effective and eco‐friendly merits. However, toxic CdS is widely used as an electron transport layer (ETL) in efficient Sb2Se3 solar cells, which largely limit their development toward market commercialization. Herein, an effective green Cd‐free ETL of SnOx is introduced and deposited by atomic layer deposition method. Additionally, an important post‐annealing treatment is designed to further optimize the functional layers and the heterojunction interface properties. Such engineering strategy can optimize SnOx ETL with higher nano‐crystallinity, higher carrier density, and less defect groups, modify Sb2Se3/SnOx heterojunction with better interface performance and much desirable “spike‐like” band alignment, and also improve the Sb2Se3 light absorber layer quality with passivated bulk defects and prolonged carrier lifetime, and therefore to enhance carrier separation and transport while suppressing non‐radiative recombination. Finally, the as‐fabricated Cd‐free Mo/Sb2Se3/SnOx/ITO/Ag thin‐film solar cell exhibits a stimulating efficiency of 7.39%, contributing a record value for Cd‐free substrate structured Sb2Se3 solar cells reported to date. This work provides a viable strategy for developing and broadening practical applications of environmental‐friendly Sb2Se3 photovoltaic devices.
Receptor Functions of Metal‐Carbonates for Solid‐Electrolyte Impedancemetric Gas Sensor
Authors: Baba Yusuke , Hasegawa Yuhei , Takase Satoko , Shimizu Youichi
Published: September 2023

Receptor functions of metal‐carbonates for solid‐electrolyte impedancemetric gas sensor based on Li‐ionic conductor (Li1.5Al0.5Ti1.5[PO4]3) were studied. It was revealed that sensors attached with metal‐carbonate receptors rarely responded to CO2, on the contrary, they well responded to NOx. In addition, it was found that the responses to NOx differed depending on the metal‐carbonates. The sensor using the binary carbonate (Li2CO3 + CaCO3) receptor showed high NO2 sensitivity and different NO responses at 300 °C, 50 Hz, i.e., other devices responded to NO2 and NO with same direction, while the binary carbonates (Li2CO3 + CaCO3) system responded to NO2 and NO in the opposite direction, which should give selective detection among NO and NO2. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.
Investigation of terrain and wake effects on the performance of wind farms in complex terrain using numerical and experimental data
Authors: Castellani Francesco , Astolfi Davide , Mana Matteo , Piccioni Emanuele , Becchetti Matteo , Terzi Ludovico
Published: September 2023

In this work, the combination effects on wind turbine performances of wakes and terrain‐driven flow are investigated. The test case is a subcluster of four turbines from a wind farm sited in southern Italy in a very complex terrain. The layout, the inter‐turbine distance and the wind rose result in a challenging performance scenery. The subcluster is analyzed, when the wind blows from the west, through computational fluid dynamics numerical simulations and experimental supervisory control and data acquisition data mining. Two wind intensity regimes and several simulation setups are employed. It is shown that the main effect of the terrain is the northward distortion of the wake of the upstream turbine. This explains the non‐trivial yawing patterns of the cluster and the fact that the wake line affects the overall performances of the subcluster less than it would do in flat terrain. It is further shown that the presence of the rest of the subcluster in operation southward deviates the wake line of the upstream turbine. The dependency on wind intensity of these directional distortions allows to estimate the relative importance of wakes and terrain‐driven flow. A bijective feedback between models and data is established and a convincing framework is constructed, for separating and assessing the effect of the terrain and of the single and multiple wake. Copyright © 2017 John Wiley & Sons, Ltd.
Imaging and monitoring of granzyme B in the immune response
Authors: Li Xiangxia , Chen Guiyuan , Wu Kecheng , Zheng Haocheng , Tian Zuotong , Xu Ze , Zhao Weidong , Weng Jianping , Min Yuanzeng
Published: September 2023

Significant progress has been made in tumor immunotherapy that uses the human immune response to kill and remove tumor cells. However, overreactive immune response could lead to various autoimmune diseases and acute rejection. Accurate and specific monitoring of immune responses in these processes could help select appropriate therapies and regimens for the patient and could reduce the risk of side effects. Granzyme B (GzmB) is an ideal biomarker for immune response, and its peptide substrate could be coupled with fluorescent dyes or contrast agents for the synthesis of imaging probes activated by GzmB. These small molecules and nanoprobes based on PET, bioluminescence imaging, or fluorescence imaging have proved to be highly GzmB specific and accuracy. This review summarizes the design of different GzmB‐responsive imaging probes and their applications in monitoring of tumor immunotherapy and overreactive immune response.

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging