bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of a State Degradation Model and Preventive Maintenance Strategies for Wind Turbine Generators Based on Stochastic Differential Equations
Authors: Su Hongsheng , Zhao Yifan , Wang Xueqian
Published: June 2023

Preventive maintenance is widely used in wind turbine equipment to ensure their safe and reliable operation, and this mainly includes time-based maintenance (TBM) and condition-based maintenance (CBM). Most wind farms only use TBM as the main maintenance strategy in engineering practice. Although this can meet certain reliability requirements, it cannot fully utilize the characteristics of TBM and CBM. For this, a state model based on the stochastic differential equation (SDE) is established in this paper to describe the spatio-temporal evolution process of the degradation behavior of wind turbine generators, in which the components’ failure is represented by a proportional hazards model, the random fluctuation of the state is simulated by the Brownian motion, and the SDE model is solved by a function transformation method. Based on the model, the characteristics of TBM and CBM, and the asymptotic relationship between them, are discussed and analyzed, the necessity and feasibility of their combination are expounded, and a joint maintenance strategy is proposed and analyzed. The results show that the stochastic model can better reflect the real deterioration state of the generator. Moreover, TBM has a fixed maintenance interval, depending on global sample tracks and, only depending on the local sample track, CBM can follow the component state. Finally, the rationality and effectiveness of the proposed model and results are verified by a practical example.
Analysis of Control Problems for Stationary Magnetohydrodynamics Equations under the Mixed Boundary Conditions for a Magnetic Field
Authors: Alekseev Gennadii
Published: June 2023

The optimal control problems for stationary magnetohydrodynamic equations under the inhomogeneous mixed boundary conditions for a magnetic field and the Dirichlet condition for velocity are considered. The role of controls in the control problems under study is played by normal and tangential components of the magnetic field given on different parts of the boundary and by the exterior current density. Quadratic tracking-type functionals for velocity, magnetic field or pressure are taken as cost functionals. The global solvability of the control problems under consideration is proved, an optimality system is derived and, based on its analysis, a mathematical apparatus for studying the local uniqueness and stability of the optimal solutions is developed. On the basis of the developed apparatus, the local uniqueness of solutions of control problems for specific cost functionals is proved, and stability estimates of optimal solutions are established.
On the Fluctuations of Internal DLA on the Sierpinski Gasket Graph
Authors: Heizmann Nico
Published: June 2023

Internal diffusion limited aggregation (IDLA) is a random aggregation model on a graph G, whose clusters are formed by random walks started in the origin (some fixed vertex) and stopped upon visiting a previously unvisited site. On the Sierpinski gasket graph, the asymptotic shape is known to be a ball in the graph metric. In this paper, we improve the sublinear bounds for the fluctuations known from its known asymptotic shape result by establishing bounds for the odometer function for a divisible sandpile model.
Relationship between the Young’s Modulus of the Achilles Tendon and Ankle Dorsiflexion Angle at Maximum Squat Depth in Healthy Young Males
Authors: Miyasaka Hayato , Ebihara Bungo , Fukaya Takashi , Mutsuzaki Hirotaka
Published: June 2023

Background and Objective: Achilles tendon (AT) stiffness can reduce ankle dorsiflexion. However, whether AT stiffness affects the ankle dorsiflexion angle at a maximum squat depth remains unclear. Therefore, we aimed to investigate the relationship between the Young’s modulus of the AT and ankle dorsiflexion angle at the maximum squat depth in healthy young males using shear-wave elastography (SWE). Materials and Methods: This cross-sectional study included 31 healthy young males. AT stiffness was measured using the Young’s modulus through SWE. The ankle dorsiflexion angle at the maximum squat depth was measured as the angle between the vertical line to the floor and the line connecting the fibula head and the lateral malleolus using a goniometer. Results: Multiple regression analysis identified the Young’s modulus of the AT at 10° of ankle dorsiflexion (standardized partial regression coefficient [β] = −0.461; p = 0.007) and the ankle dorsiflexion angle in the flexed knee (β = 0.340; p = 0.041) as independent variables for the ankle dorsiflexion angle at maximum squat depth. Conclusions: The Young’s modulus of the AT may affect the ankle dorsiflexion angle at the maximum squat depth in healthy young males. Therefore, improving the Young’s modulus of the AT may help increase the ankle dorsiflexion angle at maximum squat depth.
Uridine Derivatives: Synthesis, Biological Evaluation, and In Silico Studies as Antimicrobial and Anticancer Agents
Authors: Munia Nasrin S. , Alanazi Mohammed M. , El Bakri Youness , Alanazi Ashwag S. , Mukhrish Yousef E. , Hasan Imtiaj , Kawsar Sarkar M. A.
Published: June 2023

Nucleoside analogs are frequently used in the control of viral infections and neoplastic diseases. However, relatively few studies have shown that nucleoside analogs have antibacterial and antifungal activities. In this study, a fused pyrimidine molecule, uridine, was modified with various aliphatic chains and aromatic groups to produce new derivatives as antimicrobial agents. All newly synthesized uridine derivatives were analyzed by spectral (NMR, FTIR, mass spectrometry), elemental, and physicochemical analyses. Prediction of activity spectra for substances (PASS) and in vitro biological evaluation against bacteria and fungi indicated promising antimicrobial capability of these uridine derivatives. The tested compounds were more effective against fungal phytopathogens than bacterial strains, as determined by their in vitro antimicrobial activity. Cytotoxicity testing indicated that the compounds were less toxic. In addition, antiproliferative activity against Ehrlich ascites carcinoma (EAC) cells was investigated, and compound 6 (2′,3′-di-O-cinnamoyl-5′-O-palmitoyluridine) demonstrated promising anticancer activity. Their molecular docking against Escherichia coli (1RXF) and Salmonella typhi (3000) revealed notable binding affinities and nonbonding interactions in support of this finding. Stable conformation and binding patterns/energy were found in a stimulating 400 ns molecular dynamics (MD) simulation. Structure–activity relationship (SAR) investigation indicated that acyl chains, CH3(CH2)10CO-, (C6H5)3C-, and C2H5C6H4CO-, combined with deoxyribose, were most effective against the tested bacterial and fungal pathogens. Pharmacokinetic predictions were examined to determine their ADMET characteristics, and the results in silico were intriguing. Finally, the synthesized uridine derivatives demonstrated increased medicinal activity and high potential for future antimicrobial/anticancer agent(s).
Acoustic Atomization-Induced Pumping Based on a Vibrating Sharp-Tip Capillary
Authors: Mendis Balapuwaduge Lihini , He Ziyi , Li Xiaojun , Wang Jing , Li Chong , Li Peng
Published: June 2023

Pumping is an essential component in many microfluidic applications. Developing simple, small-footprint, and flexible pumping methods is of great importance to achieve truly lab-on-a-chip systems. Here, we report a novel acoustic pump based on the atomization effect induced by a vibrating sharp-tip capillary. As the liquid is atomized by the vibrating capillary, negative pressure is generated to drive the movement of fluid without the need to fabricate special microstructures or use special channel materials. We studied the influence of the frequency, input power, internal diameter (ID) of the capillary tip, and liquid viscosity on the pumping flow rate. By adjusting the ID of the capillary from 30 µm to 80 µm and the power input from 1 Vpp to 5 Vpp, a flow rate range of 3 to 520 µL/min can be achieved. We also demonstrated the simultaneous operation of two pumps to generate parallel flow with a tunable flow rate ratio. Finally, the capability of performing complex pumping sequences was demonstrated by performing a bead-based ELISA in a 3D-printed microdevice.
Bacterial Diversity Analysis and Screening for ACC Deaminase-Producing Strains in Moss-Covered Soil at Different Altitudes in Tianshan Mountains—A Case Study of Glacier No. 1
Authors: Shi Yanlei , Yuan Ye , Feng Yingying , Zhang Yinghao , Fan Yonghong
Published: June 2023

The elevation of the snowline of the No. 1 Glacier in the Tianshan Mountains is increasing due to global warming, which has created favorable conditions for moss invasion and offers an opportunity to investigate the synergistic effects of incipient succession by mosses, plants, and soils. In this study, the concept of altitude distance was used instead of succession time. To investigate the changes of bacterial-community diversity in moss-covered soils during glacial degeneration, the relationship between bacterial community structure and environmental factors was analyzed and valuable microorganisms in moss-covered soils were explored. To do so, the determination of soil physicochemical properties, high-throughput sequencing, the screening of ACC-deaminase-producing bacteria, and the determination of ACC-deaminase activity of strains were performed on five moss-covered soils at different elevations. The results showed that the soil total potassium content, soil available phosphorus content, soil available potassium content, and soil organic-matter content of the AY3550 sample belt were significantly different compared with those of other sample belts (p < 0.05). Secondly, there was a significant difference (p < 0.05) in the ACE index or Chao1 index between the moss-covered-soil AY3550 sample-belt and the AY3750 sample-belt bacterial communities as the succession progressed. The results of PCA analysis, RDA analysis, and cluster analysis at the genus level showed that the community structure of the AY3550 sample belt and the other four sample belts differed greatly and could be divided into two successional stages. The enzyme activities of the 33 ACC-deaminase-producing bacteria isolated and purified from moss-covered soil at different altitudes ranged from 0.067 to 4.7375 U/mg, with strains DY1–3, DY1–4, and EY2–5 having the highest enzyme activities. All three strains were identified as Pseudomonas by morphology, physiology, biochemistry, and molecular biology. This study provides a basis for the changes in moss-covered soil microhabitats during glacial degradation under the synergistic effects of moss, soil, and microbial communities, as well as a theoretical basis for the excavation of valuable microorganisms under glacial moss-covered soils.
Isolation and Characterization of Jumbo Coliphage vB_EcoM_Lh1B as a Promising Therapeutic Agent against Chicken Colibacillosis
Authors: Alexyuk Pavel , Bogoyavlenskiy Andrey , Alexyuk Madina , Akanova Kuralay , Moldakhanov Yergali , Berezin Vladimir
Published: June 2023

Colibacillosis in chickens can cause the death of young stock, decrease weight gain and lead to significant economic losses. Currently, antibiotic therapy is the main method of treatment of infected animals, but unchecked use of antibiotics has led to widespread antibiotic resistance among microorganisms. Therefore, it is necessary to develop alternative methods of treating bacterial infections that are fully consistent with the One Health concept and introduce them into practice. Phage therapy meets the specified requirements perfectly. This study describes the isolation and characterization of the lytic jumbo phage vB_EcoM_Lh1B and evaluates its potential use in controlling antibiotic-resistant E. coli infection in poultry. The complete phage genome is 240,200 bp long. Open reading frame (ORF) prediction shows that the phage genome does not contain genes encoding antibiotic resistance and lysogeny factors. Based on phylogenetic and electron microscopic analysis, vB_EcoM_Lh1B belongs to the group of myoviruses of the Seoulvirus genus of the Caudoviricetes class. The bacteriophage has good resistance to a wide range of pH and temperatures and has the ability to suppress 19 out of 30 studied pathogenic E. coli strains. The biological and lytic properties of the isolated vB_EcoM_Lh1B phage make it a promising target of further study as a therapeutic agent against E. coli infections in poultry.
Quantitative Lipidome Analysis of Boiled Chicken Egg Yolk under Different Heating Intensities
Authors: Luo Wei , Wang Jinghui , Chen Yan , Zhang Qionglian , Wang Jinqiu , Geng Fang
Published: June 2023

The effects of the four heating intensities (hot-spring egg yolk, HEY; soft-boiled egg yolk, SEY; normal-boiled egg yolk, NEY; and over-boiled egg yolk, OEY) on lipidomes of boiled egg yolks were investigated. The results indicated that four heating intensities had no significant effect on the total abundance of lipids and lipid categories except for bile acids, lysophosphatidylinositol, and lysophosphatidylcholine. However, of all the 767 lipids quantified, the differential abundance of 190 lipids was screened among the egg yolk samples at four heating intensities. Soft-boiling and over-boiling altered the assembly structure of the lipoproteins through thermal denaturation and affected the binding of lipids and apoproteins, resulting in an increase in low-to-medium-abundance triglycerides. The decreased phospholipid and increased lysophospholipid and free fatty acid in HEY and SEY suggests potential hydrolysis of phospholipids under relatively low-intensity heating. Results provide new insights into the effect of heating on the lipid profiles of egg yolk and would support the public’s choice of cooking method for egg yolks.
Comprehensive Understanding of the Kinetic Behaviors of Main Protease from SARS-CoV-2 and SARS-CoV: New Data and Comparison to Published Parameters
Authors: Li Fangya , Fang Tingting , Guo Feng , Zhao Zipeng , Zhang Jianyu
Published: June 2023

The main protease (Mpro) is a promising drug target for inhibiting the coronavirus due to its conserved properties and lack of homologous genes in humans. However, previous studies on Mpro’s kinetic parameters have been confusing, hindering the selection of accurate inhibitors. Therefore, obtaining a clear view of Mpro’s kinetic parameters is necessary. In our study, we investigated the kinetic behaviors of Mpro from SARS-CoV-2 and SARS-CoV using both FRET-based cleavage assay and the LC-MS method, respectively. Our findings indicate that the FRET-based cleavage assay could be used for preliminary screening of Mpro inhibitors, while the LC-MS method should be applied to select the effective inhibitors with higher reliability. Furthermore, we constructed the active site mutants (H41A and C145A) and measured the kinetic parameters to gain a deeper understanding of the atomic-level enzyme efficiency reduction compared to the wild type. Overall, our study provides valuable insights for inhibitor screening and design by offering a comprehensive understanding of Mpro’s kinetic behaviors.
CO Electroreduction Mechanism on Single-Atom Zn (101) Surfaces: Pathway to C2 Products
Authors: Wang Yixin , Zheng Ming , Zhou Xin , Pan Qingjiang , Li Mingxia
Published: June 2023

Electrocatalytic reduction of carbon dioxide (CO2RR) employs electricity to store renewable energy in the form of reduction products. The activity and selectivity of the reaction depend on the inherent properties of electrode materials. Single-atom alloys (SAAs) exhibit high atomic utilization efficiency and unique catalytic activity, making them promising alternatives to precious metal catalysts. In this study, density functional theory (DFT) was employed to predict stability and high catalytic activity of Cu/Zn (101) and Pd/Zn (101) catalysts in the electrochemical environment at the single-atom reaction site. The mechanism of C2 products (glyoxal, acetaldehyde, ethylene, and ethane) produced by electrochemical reduction on the surface was elucidated. The C-C coupling process occurs through the CO dimerization mechanism, and the formation of the *CHOCO intermediate proves beneficial, as it inhibits both HER and CO protonation. Furthermore, the synergistic effect between single atoms and Zn results in a distinct adsorption behavior of intermediates compared to traditional metals, giving SAAs unique selectivity towards the C2 mechanism. At lower voltages, the Zn (101) single-atom alloy demonstrates the most advantageous performance in generating ethane on the surface, while acetaldehyde and ethylene exhibit significant certain potential. These findings establish a theoretical foundation for the design of more efficient and selective carbon dioxide catalysts.
Electrocatalytic Performance of MnMoO4-rGO Nano-Electrocatalyst for Methanol and Ethanol Oxidation
Authors: Salarizadeh Parisa , Azizi Sadegh , Beydaghi Hossein , Bagheri Ahmad , Askari Mohammad Bagher
Published: June 2023

Today, finding low-cost electro-catalysts for methanol and ethanol oxidation with high performance and stability is one of the new research topics. A nanocatalyst based on metal oxides in the form of MnMoO4 was synthesized by a hydrothermal method for methanol (MOR) and ethanol (EOR) oxidation reactions. Adding reduced graphene oxide (rGO) to the catalyst structure improved the electrocatalytic activity of MnMoO4 for the oxidation processes. The crystal structure and morphology of the MnMoO4 and MnMoO4-rGO nanocatalysts were investigated by physical analyses such as scanning electron microscopy and X-ray diffraction. Their abilities for MOR and EOR processes in an alkaline medium were evaluated by performing electrochemical tests such as cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. MnMoO4-rGO showed oxidation current densities of 60.59 and 25.39 mA/cm2 and peak potentials of 0.62 and 0.67 V in MOR and EOR processes (at a scan rate of 40 mV/s), respectively. Moreover, stabilities of 91.7% in MOR and 88.6% in EOR processes were obtained from the chronoamperometry analysis within 6 h. All these features make MnMoO4-rGO a promising electrochemical catalyst for the oxidation of alcohols.
Nanomaterials with Glucose Oxidase-Mimicking Activity for Biomedical Applications
Authors: Min Shengyi , Yu Qiao , Ye Jiaquan , Hao Pengfei , Ning Jiayu , Hu Zhiqiang , Chong Yu
Published: June 2023

Glucose oxidase (GOD) is an oxidoreductase that catalyzes the aerobic oxidation of glucose into hydrogen peroxide (H2O2) and gluconic acid, which has been widely used in industrial raw materials production, biosensors and cancer treatment. However, natural GOD bears intrinsic disadvantages, such as poor stability and a complex purification process, which undoubtedly restricts its biomedical applications. Fortunately, several artificial nanomaterials have been recently discovered with a GOD-like activity and their catalytic efficiency toward glucose oxidation can be finely optimized for diverse biomedical applications in biosensing and disease treatments. In view of the notable progress of GOD-mimicking nanozymes, this review systematically summarizes the representative GOD-mimicking nanomaterials for the first time and depicts their proposed catalytic mechanisms. We then introduce the efficient modulation strategy to improve the catalytic activity of existing GOD-mimicking nanomaterials. Finally, the potential biomedical applications in glucose detection, DNA bioanalysis and cancer treatment are highlighted. We believe that the development of nanomaterials with a GOD-like activity will expand the application range of GOD-based systems and lead to new opportunities of GOD-mimicking nanomaterials for various biomedical applications.
Computational Study of Photodegradation Process and Conversion Products of the Antidepressant Citalopram in Water
Authors: Shen Yifan , Wang Se , Lu Ying , Chen Kai , Luo Li , Hao Ce
Published: June 2023

Citalopram (CIT) is a commonly prescribed medication for depression. However, the photodegradation mechanism of CIT has not yet been fully analyzed. Therefore, the photodegradation process of CIT in water is studied by density functional theory and time-dependent density functional theory. The calculated results show that during the indirect photodegradation process, the indirect photodegradation of CIT with ·OH occurs via OH-addition and F-substitution. The minimum activation energy of C10 site was 0.4 kcal/mol. All OH-addition and F-substitution reactions are exothermic. The reaction of 1O2 with CIT includes the substitution of 1O2 for F and an addition reaction at the C14 site. The Ea value of this process is 1.7 kcal/mol, which is the lowest activation energy required for the reaction of 1O2 with CIT. C–C/C–N/C–F cleavage is involved in the direct photodegradation process. In the direct photodegradation of CIT, the activation energy of the C7-C16 cleavage reaction was the lowest, which was 12.5 kcal/mol. Analysis of the Ea values found that OH-addition and F-substitution, the substitution of 1O2 for F and addition at the C14 site, as well as the cleavage reactions of C6–F/C7–C16/C17–C18/C18–N/C19–N/C20–N are the main pathways of photodegradation of CIT.
pH-Responsive Viscoelastic Fluids of a C22-Tailed Surfactant Induced by Trivalent Metal Ions
Authors: Xu Zhi , Yu Shuai , Fu Rong , Wang Ji , Feng Yujun
Published: June 2023

pH-responsive viscoelastic fluids are often achieved by adding hydrotropes into surfactant solutions. However, the use of metal salts to prepare pH-responsive viscoelastic fluids has been less documented. Herein, a pH-responsive viscoelastic fluid was developed by blending an ultra-long-chain tertiary amine, N-erucamidopropyl-N, N-dimethylamine (UC22AMPM), with metal salts (i.e., AlCl3, CrCl3, and FeCl3). The effects of the surfactant/metal salt mixing ratio and the type of metal ions on the viscoelasticity and phase behavior of fluids were systematically examined by appearance observation and rheometry. To elucidate the role of metal ions, the rheological properties between AlCl3− and HCl−UC22AMPM systems were compared. Results showed the above metal salt evoked the low-viscosity UC22AMPM dispersions to form viscoelastic solutions. Similar to HCl, AlCl3 could also protonate the UC22AMPM into a cationic surfactant, forming wormlike micelles (WLMs). Notably, much stronger viscoelastic behavior was evidenced in the UC22AMPM−AlCl3 systems because the Al3+ as metal chelators coordinated with WLMs, promoting the increment of viscosity. By tuning the pH, the macroscopic appearance of the UC22AMPM−AlCl3 system switched between transparent solutions and milky dispersion, concomitant with a viscosity variation of one order of magnitude. Importantly, the UC22AMPM−AlCl3 systems showed a constant viscosity of 40 mPa·s at 80 °C and 170 s−1 for 120 min, indicative of good heat and shear resistances. The metal-containing viscoelastic fluids are expected to be good candidates for high-temperature reservoir hydraulic fracturing.
Acid–Base Properties of Oxides Derived from Oxide Melt Solution Calorimetry
Authors: Navrotsky Alexandra , Koryttseva Anastasia
Published: June 2023

The paper analyzes the relationships among acid–base interactions in various oxide systems and their thermodynamics. Extensive data on enthalpies of solution of binary oxides in oxide melts of several compositions, obtained by high-temperature oxide melt solution calorimetry at 700 and 800 °C, are systematized and analyzed. Oxides with low electronegativity, namely the alkali and alkaline earth oxides, which are strong oxide ion donors, show enthalpies of solution that have negative values greater than −100 kJ per mole of oxide ion. Their enthalpies of solution become more negative with decreasing electronegativity in the order Li, Na, K and Mg, Ca, Sr, Ba in both of the commonly used molten oxide calorimetric solvents: sodium molybdate and lead borate. Oxides with high electronegativity, including P2O5, SiO2, GeO2, and other acidic oxides, dissolve more exothermically in the less acidic solvent (lead borate). The remaining oxides, with intermediate electronegativity (amphoteric oxides) have enthalpies of solution of between +50 and −100 kJ/mol, with many close to zero. More limited data for the enthalpies of solution of oxides in multicomponent aluminosilicate melts at higher temperature are also discussed. Overall, the ionic model combined with the Lux–Flood description of acid–base reactions provide a consistent and useful interpretation of the data and their application for understanding the thermodynamic stability of ternary oxide systems in solid and liquid states.
Physical and Chemical Properties of Vegetable Films Based on Pumpkin Purée and Biopolymers of Plant and Animal Origin
Authors: Janowicz Monika , Kadzińska Justyna , Bryś Joanna , Ciurzyńska Agnieszka , Karwacka Magdalena , Galus Sabina
Published: June 2023

Highly methylated apple pectin (HMAP) and pork gelatin (PGEL) have been proposed as gelling agents for pumpkin purée-based films. Therefore, this research aimed to develop and evaluate the physiochemical properties of composite vegetable films. Granulometric analysis of film-forming solutions showed a bimodal particle size distribution, with two peaks near 25 µm and close to 100 µm in the volume distribution. The diameter D4.3, which is very sensitive to the presence of large particles, was only about 80 µm. Taking into account the possibility of creating a polymer matrix from pumpkin purée, its chemical characteristic was determined. The content of water-soluble pectin was about 0.2 g/100 g fresh mass, starch at the level of 5.5 g/100 g fresh mass, and protein at the level of about 1.4 g/100 g fresh mass. Glucose, fructose, and sucrose, the content of which ranged from about 1 to 1.4 g/100 g fresh mass, were responsible for the plasticizing effect of the purée. All of the tested composite films, based on selected hydrocolloids with the addition of pumpkin purée, were characterized by good mechanical strength, and the obtained parameters ranged from about 7 to over 10 MPa. Differential scanning calorimetry (DSC) analysis determined that the gelatin melting point ranged from over 57 to about 67 °C, depending on the hydrocolloid concentration. The modulated differential scanning calorimetry (MDSC) analysis results exhibited remarkably low glass transition temperature (Tg) values, ranging from −34.6 to −46.5 °C. These materials are not in a glassy state at room temperature (~25 °C). It was shown that the character of the pure components affected the phenomenon of water diffusion in the tested films, depending on the humidity of the surrounding environment. Gelatin-based films were more sensitive to water vapor than pectin ones, resulting in higher water uptake over time. The nature of the changes in water content as a function of its activity indicates that composite gelatin films, with the addition of pumpkin purée, are characterized by a greater ability to adsorb moisture from the surrounding environment compared to pectin films. In addition, it was observed that the nature of the changes in water vapor adsorption in the case of protein films is different in the first hours of adsorption than in the case of pectin films, and changes significantly after 10 h of the film staying in an environment with relative humidity RH = 75.3%. The obtained results showed that pumpkin purée is a valuable plant material, which can form continuous films with the addition of gelling agents; however, practical application as edible sheets or wraps for food products needs to be preceded with additional research on its stability and interactions between films and food ingredients.
Simulation Study for the Adsorption of Carbon Disulfide on Hydroxyl Modified Activated Carbon
Authors: Cui Xiangyu , Li Penghui , Hu Baohua , Yang Teng , Fu Haichao , Chen Shuai , Zhang Xiaolai
Published: June 2023

In this study, grand canonical Monte Carlo simulations (GCMC) and molecular dynamics simulations (MD) were used to construct models of activated carbon with hydroxyl-modified hexachlorobenzene basic unit contents of 0%, 12.5%, 25%, 35% and 50%. The mechanism of adsorption of carbon disulfide (CS2) by hydroxyl-modified activated carbon was then studied. It is found that the introduction of hydroxyl functional groups will improve the adsorption capacity of activated carbon for carbon disulfide. As far as the simulation results are concerned, the activated carbon model containing 25% hydroxyl modified activated carbon basic units has the best adsorption performance for carbon disulfide molecules at 318 K and atmospheric pressure. At the same time, the changes in the porosity, accessible surface area of the solvent, ultimate diameter and maximum pore diameter of the activated carbon model also led to great differences in the diffusion coefficient of carbon disulfide molecules in different hydroxyl-modified activated carbons. However, the same adsorption heat and temperature had little effect on the adsorption of carbon disulfide molecules.
Donor–Acceptor–Donor 1H-Benzo[d]imidazole Derivatives as Optical Waveguides
Authors: Tardío Carlos , Álvarez Conde Javier , Rodríguez Ana María , Prieto Pilar , Hoz Antonio de la , Cabanillas-González Juan , Torres-Moya Iván
Published: June 2023

A new series of donor–acceptor–donor (D–A–D) structures derived from arylethynyl 1H-benzo[d]imidazole was synthesized and processed into single crystals with the goal of testing such crystals’ ability to act as optical waveguides. Some crystals displayed luminescence in the 550–600 nm range and optical waveguiding behavior with optical loss coefficients around 10−2 dB/μm, which indicated a notable light transport. The crystalline structure, confirmed by X-ray diffraction, contains internal channels that are important for light propagation, as we previously reported. The combination of a 1D assembly, a single crystal structure, and notable light emission properties with low losses from self-absorption made 1H-benzo[d]imidazole derivatives appealing compounds for optical waveguide applications.
Conformational Changes in Surface-Immobilized Proteins Measured Using Combined Atomic Force and Fluorescence Microscopy
Authors: Staii Cristian
Published: June 2023

Biological organisms rely on proteins to perform the majority of their functions. Most protein functions are based on their physical motions (conformational changes), which can be described as transitions between different conformational states in a multidimensional free-energy landscape. A comprehensive understanding of this free-energy landscape is therefore of paramount importance for understanding the biological functions of proteins. Protein dynamics includes both equilibrium and nonequilibrium motions, which typically exhibit a wide range of characteristic length and time scales. The relative probabilities of various conformational states in the energy landscape, the energy barriers between them, their dependence on external parameters such as force and temperature, and their connection to the protein function remain largely unknown for most proteins. In this paper, we present a multimolecule approach in which the proteins are immobilized at well-defined locations on Au substrates using an atomic force microscope (AFM)-based patterning method called nanografting. This method enables precise control over the protein location and orientation on the substrate, as well as the creation of biologically active protein ensembles that self-assemble into well-defined nanoscale regions (protein patches) on the gold substrate. We performed AFM–force compression and fluorescence experiments on these protein patches and measured the fundamental dynamical parameters such as protein stiffness, elastic modulus, and transition energies between distinct conformational states. Our results provide new insights into the processes that govern protein dynamics and its connection to protein function.
Biomass Derived N-Doped Porous Carbon Made from Reed Straw for an Enhanced Supercapacitor
Authors: Liao Yuyi , Shang Zhongtao , Ju Guangrui , Wang Dingke , Yang Qiao , Wang Yuan , Yuan Shaojun
Published: June 2023

Developing advanced carbon materials by utilizing biomass waste has attracted much attention. However, porous carbon electrodes based on the electronic-double-layer-capacitor (EDLC) charge storage mechanism generally presents unsatisfactory capacitance and energy density. Herein, an N-doped carbon material (RSM-0.33-550) was prepared by directly pyrolyzing reed straw and melamine. The micro- and meso-porous structure and the rich active nitrogen functional group offered more ion transfer and faradaic capacitance. X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) measurements were used to characterize the biomass-derived carbon materials. The prepared RSM-0.33-550 possessed an N content of 6.02% and a specific surface area of 547.1 m2 g−1. Compared with the RSM-0-550 without melamine addition, the RSM-0.33-550 possessed a higher content of active nitrogen (pyridinic-N) in the carbon network, thus presenting an increased number of active sites for charge storage. As the anode for supercapacitors (SCs) in 6 M KOH, RSM-0.33-550 exhibited a capacitance of 202.8 F g−1 at a current density of 1 A g−1. At a higher current density of 20 A g−1, it still retained a capacitance of 158 F g−1. Notably, it delivered excellent stability with capacity retention of 96.3% at 20 A g−1 after 5000 cycles. This work not only offers a new electrode material for SCs, but also gives a new insight into rationally utilizing biomass waste for energy storage.
A Review of IsomiRs in Colorectal Cancer
Authors: Lausten Molly A. , Boman Bruce M.
Published: June 2023

As advancements in sequencing technology rapidly continue to develop, a new classification of microRNAs has occurred with the discovery of isomiRs, which are relatively common microRNAs with sequence variations compared to their established template microRNAs. This review article seeks to compile all known information about isomiRs in colorectal cancer (CRC), which has not, to our knowledge, been gathered previously to any great extent. A brief overview is given of the history of microRNAs, their implications in colon cancer, the canonical pathway of biogenesis and isomiR classification. This is followed by a comprehensive review of the literature that is available on microRNA isoforms in CRC. The information on isomiRs presented herein shows that isomiRs hold great promise for translation into new diagnostics and therapeutics in clinical medicine.
Decreased Expression of KLF4 Leading to Functional Deficit in Pediatric Patients with Intestinal Failure and Potential Therapeutic Strategy Using Decanoic Acid
Authors: Yan Junkai , Zhao Yuling , Jiang Lu , Wang Ying , Cai Wei
Published: June 2023

Pediatric intestinal failure (IF) is the reduction in gut function to below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. The overall goal in treating IF is to achieve intestinal adaptation; however, the underlying mechanisms have not been fully understood. In this study, by performing single-cell RNA sequencing in pediatric IF patients, we found that decreased Kruppel-Like Factor 4 (KLF4) may serve as the hub gene responsible for the functional deficit in mature enterocytes in IF patients, leading to the downregulation of solute carrier (SLC) family transporters (e.g., SLC7A9) and, consequently, nutrient malabsorption. We also found that inducible KLF4 was highly sensitive to the loss of certain enteral nutrients: in a rodent model of total parenteral nutrition mimicking the deprivation of enteral nutrition, the expression of KLF4 dramatically decreased only at the tip of the villus and not at the bottom of crypts. By using IF patient-derived intestinal organoids and Caco-2 cells as in vitro models, we demonstrated that the supplementation of decanoic acid (DA) could significantly induce the expression of KLF4 along with SLC6A4 and SLC7A9, suggesting that DA may function as a potential therapeutic strategy to promote cell maturation and functional improvement. In summary, this study provides new insights into the mechanism of intestinal adaptation depending on KLF4, and proposed potential strategies for nutritional management using DA.
Sarcopenic Dysphagia Revisited: A Cross-Sectional Study in Hospitalized Geriatric Patients
Authors: Calles Marcel , Wirth Rainer , Labeit Bendix , Muhle Paul , Suntrup-Krueger Sonja , Dziewas Rainer , Lueg Gero , Trampisch Ulrike Sonja
Published: June 2023

Oropharyngeal dysphagia (OD) is a frequent finding in older patients with potentially lethal complications such as aspiration pneumonia, malnutrition, and dehydration. Recent studies describe sarcopenia as a causative factor for OD, which is occasionally referred to as “sarcopenic dysphagia” in the absence of a neurogenic etiology. In most of the previous studies on sarcopenic dysphagia, the diagnosis was based only on clinical assessment. In this study, flexible endoscopic evaluation of swallowing (FEES) was used as an objective method to evaluate the presence of OD, its association with sarcopenia, and the presence of pure sarcopenic dysphagia. In this retrospective cross-sectional study, 109 acute care geriatric hospital patients with suspected OD received FEES examination and bioimpedance analysis (BIA) in clinical routine. 95% of patients had at least one neurological disease, 70% fulfilled the criteria for sarcopenia, and 45% displayed moderate or severe OD. Although the prevalence of sarcopenia and OD was high, there was no significant association between OD and sarcopenia. Considering these results, both the association between sarcopenia and OD and pure sarcopenic dysphagia appear questionable. Further prospective studies are needed to elucidate if sarcopenia is merely an epiphenomenon of severe disease or whether it plays a causative role in the development of OD.
Efficacy and Safety of Enteral Human Recombinant Insulin to Reduce the Time to Full Enteral Feeding in Preterm Infants: A Meta-Analytical Study
Authors: Qudsia Faiza , Adil Muhammad , Kamran Maha , Azam Muhammad , Cheema Huzaifa Ahmad , Shahid Abia , Cherrez-Ojeda Ivan
Published: June 2023

Recombinant human insulin plays an important role in the gut maturation of preterm infants. This meta-analysis was carried out to assess the efficacy and safety of enteral recombinant human insulin in decreasing the time to full enteral feeding in preterm infants. The pooling of data from four clinical trials yielded a significant decrease in the time to full enteral feeding in preterm infants under both low (Mean difference [MD] −3.43 days; 95% CI: −6.18 to −0.69 days; I2 = 48%) and high doses of insulin (MD −7.10 days; 95% CI: −10.02 to −4.18 days; I2 = 0%). These findings require confirmation by further large trials that evaluate the efficacy and safety of enteral insulin, especially at supraphysiological doses.
Sex-Related Differences in the Pharmacological Response in SARS-CoV-2 Infection, Dyslipidemia, and Diabetes Mellitus: A Narrative Review
Authors: Lombrea Adelina , Romanescu Mirabela , Jianu Narcisa , Andor Minodora , Suciu Maria , Man Dana Emilia , Danciu Corina , Dehelean Cristina Adriana , Buda Valentina
Published: June 2023

Pharmacological responses vary by sex in several illnesses. This narrative review summarizes sex variations in pharmaceutical response in SARS-CoV-2 infection, dyslipidemia, and diabetes mellitus. Infection with SARS-CoV-2 is more severe and deadly in men than women. This may be attributed to immunological responses, genetics, and hormones. Some research shows that men may respond better to genomic vaccinations and females to antiviral medications such as remdesivir (Moderna and Pfizer-BioNTech). In dyslipidemia, women tend to have greater HDL-C and lower LDL-C than men. Some studies show that females may need lower statin dosages than men to obtain equal LDL-C reductions. Ezetimibe co-administered with a statin significantly improved lipid profile indicators in men compared to women. Statins reduce dementia risk. Atorvastatin decreased dementia risk in males (adjusted HR 0.92, 95% CI 0.88–0.97), whereas lovastatin lowered dementia risk in women (HR 0.74, 95% CI 0.58–0.95). In diabetes mellitus, evidence suggests that females may have a higher risk of developing certain complications such as diabetic retinopathy and neuropathy, despite having lower rates of cardiovascular disease than males. This could be the result of differences in hormonal influences and genetic factors. Some research shows females may respond better to oral hypoglycemic medications such as metformin. In conclusion, sex-related differences in pharmacological response have been observed in SARS-CoV-2 infection, dyslipidemia, and diabetes mellitus. Further research is needed to better understand these differences and to develop personalized treatment strategies for males and females with these conditions.
Medication and ECG Patterns That May Hinder SPECT Myocardial Perfusion Scans
Authors: Sidrak Marko Magdi Abdou , De Feo Maria Silvia , Gorica Joana , Corica Ferdinando , Conte Miriam , Filippi Luca , De Vincentis Giuseppe , Frantellizzi Viviana
Published: June 2023

Coronary artery disease (CAD) is the leading cause of death followed by cancer, in men and women. With risk factors being endemic and the increasing costs of healthcare for management and treatment, myocardial perfusion imaging (MPI) finds a central role in risk stratification and prognosis for CAD patients, but it comes with its limitations in that the referring clinician and managing team must be aware of and use at their advantage. This narrative review examines the utility of myocardial perfusion scans in the diagnosis and management of patients with ECG alterations such as atrioventricular block (AVB), and medications including calcium channel blockers (CCB), beta blockers (BB), and nitroglycerin which may impact the interpretation of the exam. The review analyzes the current evidence and provides insights into the limitations, delving into the reasons behind some of the contraindications to MPI.
Stereoisomer-Dependent Membrane Association and Capacity for Insulin Delivery Facilitated by Penetratin
Authors: Birch Ditlev , Sayers Edward J. , Christensen Malene V. , Jones Arwyn T. , Franzyk Henrik , Nielsen Hanne M.
Published: June 2023

Cell-penetrating peptides (CPPs), such as penetratin, are often investigated as drug delivery vectors and incorporating d-amino acids, rather than the natural l-forms, to enhance proteolytic stability could improve their delivery efficiency. The present study aimed to compare membrane association, cellular uptake, and delivery capacity for all-l and all-d enantiomers of penetratin (PEN) by using different cell models and cargos. The enantiomers displayed widely different distribution patterns in the examined cell models, and in Caco-2 cells, quenchable membrane binding was evident for d-PEN in addition to vesicular intracellular localization for both enantiomers. The uptake of insulin in Caco-2 cells was equally mediated by the two enantiomers, and while l-PEN did not increase the transepithelial permeation of any of the investigated cargo peptides, d-PEN increased the transepithelial delivery of vancomycin five-fold and approximately four-fold for insulin at an extracellular apical pH of 6.5. Overall, while d-PEN was associated with the plasma membrane to a larger extent and was superior in mediating the transepithelial delivery of hydrophilic peptide cargoes compared to l-PEN across Caco-2 epithelium, no enhanced delivery of the hydrophobic cyclosporin was observed, and intracellular insulin uptake was induced to a similar degree by the two enantiomers.
Progress of Organic/Inorganic Luminescent Materials for Optical Wireless Communication Systems
Authors: Martínez Javier , Osorio-Roman Igor , Gualdrón-Reyes Andrés F.
Published: June 2023

The growing demand for faster data transference and communication allowed the development of faster and more efficient communication network-based technologies, with wider bandwidth capability, high resilience to electromagnetic radiation, and low latency for information travelling. To provide a suitable alternative to satisfy data transmission and consumption demand, wireless systems were established after a decade of studies on this topic. More recently, visible light communication (VLC) processes were incorporated as interesting wireless approaches that make use of a wide frequency communication spectrum to reach higher bandwidth values and accelerate the speed of data/information transmission. For this aim, light converters, such as phosphor materials, are reported to efficiently convert blue light into green, yellow, and red emissions; however, long carrier lifetimes are achieved to enlarge the frequency bandwidth, thereby delaying the data transference rate. In this review, we focused on recent advances using different luminescent materials based on prominent polymers, organic molecules, and semiconductor nanocrystals with improved photophysical properties and favored carrier recombination dynamics, which are suitable to enhance the VLC process. Here, the main features of the above materials are highlighted, providing a perspective on the use of luminescent systems for efficient optical communication applications.
Detection of Benzoic Acid Additive Based on a Terahertz Metasurface Sensor
Authors: Ma Siyuan , Li Fanghao , Su Yan , Chen Lirong , Song Yunfeng , Ye Junhao
Published: June 2023

Benzoic acid and its derivative benzoate are widely utilized as food preservatives. This paper presents a highly sensitive method for detecting benzoic acid using a cross-shaped aluminum resonator integrated on top of a polyimide substrate. The resonance dip for benzoic acid was designed to be at 0.93 THz. The terahertz (THz) transmission spectrum was simulated using a designed structure with varying thicknesses of benzoic acid. Analysis of the spectral response of the THz resonance dips to the thickness of the benzoic acid layer shows that the amplitude of the resonance dips generally increases with an increase in the benzoic acid concentration. The spectral frequency shifts and transmission intensities both demonstrate high sensitivity of the metasurface sensor to trace benzoic acid thicknesses. The sensor exhibits a sensitivity of approximately 0.247 THz/RIU (Refractive Index Unit) and FOM (figure of merit) of 3.927/RIU. The THz metasurface sensor is a fast and accurate sensing tool that can detect trace substances, making it crucial in the field of food safety.
All-Polarization-Maintaining, Mode-Locking Fiber Front-End Laser Delivering Both the Picosecond Seed Laser and the Femtosecond Seed Laser
Authors: Zhang Yinuo , Zhang Hao , Gao Kong , Qiao Wenchao , Feng Tianli , Zhao Xian , Liu Yizhou
Published: June 2023

An ytterbium-doped, mode-locking fiber front-end laser, delivering both a femtosecond seed laser and picosecond seed laser, was demonstrated. The fundamental repetition rate of the 1031 nm mode-locked laser was 32.77 MHz, realized with the all-polarization-maintaining (all-PM) nonlinear amplifying loop mirror (NALM). The femtosecond seed laser and the picosecond seed laser were delivered after carefully optimizing the nonlinear amplification process. The corresponding pulse durations were 85 fs and 2.88 ps, with average power of 171 mW and 562.5 mW, respectively.