bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collapsing Shear‐Free Anisotropic Embedding Star Model in f(R)$f(R)$ Gravity
Authors: Nazar Hammad , Abbas Ghulam , Abbas Athar , Qaisar Shahid 
Published: February 2024

AbstractThe current paper studied the dynamics of shear‐free and spherically symmetric collapsing stars by incorporating the features of anisotropic dissipative fluid in the realm of gravity. A complete radiative star model that describes the early static configuration obeying the embedding class 1 approach is generated. To acquittance the exact solutions of the geometric variables, a specific form of pressure anisotropy along with a time‐dependent Karmarkar condition is employed, leading to a spacetime solution that seems to be potentially reliable and regular throughout the collapse process. The matching conditions have been thoroughly investigated between the interior geometry and the Vaidya outgoing solution over the junction interface. The physical attributes of our solutions to the Einstein field equations under two viable and cosmologically well‐consistent models of are manifested. The presented features are in a stable equilibrium state and sustainable to model a dynamic structure of gravitational collapse without forming the black hole.
Recent advancements in disulfide bridge characterization: Insights from mass spectrometry
Authors: Chaturvedi Sachin , Bawake Sanket , Sharma Nitish 
Published: February 2024

RationaleDisulfide bridges (DSB) play an important role in stabilizing three‐dimensional structures of biopharmaceuticals, single purified proteins, and various cyclic peptide drugs that contain disulfide in their structures. Incorrect cross‐linking known as DSB scrambling results in misfolded structures that can be inactive, immunogenic, and susceptible to aggregation. Very few articles have been published on the experimental annotation of DSBs in proteins and cyclic peptide drugs. Accurate characterization of the disulfide bond is essential for understanding protein confirmation.MethodsCharacterizing DSBs using mass spectrometry (MS) involves the chemical and enzymatic digestion of samples to obtain smaller peptide fragments, in both reduced and nonreduced forms. Subsequently, these samples are analyzed using MS to locate the DSB, either through interpretation or by employing various software tools.ResultsThe main challenge in DSB analysis methods using sample preparation is to obtain a sample solution in which nonnative DSBs are not formed due to high pH, temperature, and presence of free sulfhydryl groups. Formation of nonnative DSBs can lead to erroneous annotation of disulfide bond. Sample preparation techniques, fragmentation methods for DSB analysis, and contemporary approaches for DSB mapping using this fragmentation were discussed.ConclusionsThis review presents the latest advancement in MS‐based characterization; also a critical perspective is presented for further annotation of DSBs using MS, primarily for single purified proteins or peptides that are densely connected and rich in cysteine. Despite significant breakthroughs resulting from advancements in MS, the analysis of disulfide bonds is not straightforward; it necessitates expertise in sample preparation and interpretation.
Adaptive fault‐tolerant platooning control for nonlinear homogeneous multiple autonomous vehicles under unreliable communication networks
Authors: Wang Xin , Park Ju H. , Liu Heng , Zhang Xian 
Published: February 2024

AbstractThis article presents a fault‐tolerant platooning control algorithm for a class of nonlinear homogeneous multi‐vehicle systems under unreliable network communication environment. The considered types of actuator failures in individual vehicle are loss‐in‐effectiveness, and bias faults. Suppose the communication network among vehicles is here described as a switching graph subject to intermittent communications. Unlike the existing results dealing with vehicle platoon under continuous communications, this article develops a hierarchical fault‐tolerant platooning control approach, under which, the multiple vehicle coordination platooning objective is ensured even in the cases of discontinuous communication faults and actuator failures. First, each following vehicle can estimate the desire reference information via cooperative adaptive virtual estimator even in intermittent communications. Second, the local fault‐tolerant controller with adaptive parameter update mechanism can guarantee the practical position and velocity of following vehicles asymptotically track the desire estimations. Finally, a simulation example of a team of autonomous vehicles is given to verify the effectiveness of the proposed method.
A series of 2‐phenylbenzothiazole‐based iridium complexes with N‐H derivatives: synthesis, photophysics, DFT calculations and a preliminary exploration in fluoride ions sensing
Authors: Chen Meng‐Sen , Zhou Qin , Xiang Yi‐Xing , Mo Zheng‐Rong , Niu Zhi‐Gang , Guo Shu , Li Gao‐Nan 
Published: February 2024

AbstractA series of new pbt‐based Ir(III) complexes containing N−H derivatives ancillary ligands (piz/pbiz) were designed and synthesized rationally, naming [(CH3Opbt)2Ir(piz)][PF6] (Ir1), [(CF3pbt)2Ir(piz)][PF6] (Ir2), [(Fpbt)2Ir(piz)][PF6] (Ir3), [(CH3Opbt)2Ir(pbiz)][PF6] (Ir4), [(CF3pbt)2Ir(pbiz)][PF6] (Ir5) and [(Fpbt)2Ir(pbiz)][PF6] (Ir6) (where pbt=2‐phenylbenzothiazole, piz=2‐(1H‐imidazol‐2‐yl)pyridine, and pbiz=2‐(pyridin‐2‐yl)‐1H‐benzoimidazole). Combined with photophysical properties and theoretical calculations, their structure‐property relationships were systematically researched. These iridium(III) complexes are phosphorescent in the green and yellow‐green region with quantum yields of 14.1–28.7 % and lifetimes of 0.35–0.88 μs. Considering the relatively high quantum yield and imidazole group on ancillary ligands, [(CF3pbt)2Ir(pbiz)][PF6] (Ir5) was preliminary explored as the phosphorescent sensor toward F− ions. The results showed that the addition of fluoride ions to complex Ir5 in dichloromethane solution induced a red shift of the emission color, along with an enhancement in the luminescent intensity. Theoretical calculations were carried out to understand the mechanism, and the results reveal that the hydrogen bonding interaction of N−H bond with F− influence the electron transfer processes of the lowest energy absorption and emission, leading to a significant change in the photophysical properties.
Antioxidant and cytotoxic properties of water‐soluble crude polysaccharides from two edible mushroom species of Ramaria
Authors: Muñoz‐Castiblanco Tatiana , Santa Maria de la Parra Lucía , Peña‐Cañón Rocio , Muñoz‐Losada Kelly , Mejía‐Giraldo Juan Camilo , León Ignacio E. , Puertas‐Mejía Miguel Ángel 
Published: February 2024

AbstractWater‐soluble crude polysaccharides (WSCPs) were isolated from the fruiting bodies of Ramaria flava (Schaeff.) Quél. (RFCP) and Ramaria cf. aurea (Schaeff.) Quél. (RACP). Species of Ramaria were collected in Boyacá‐Colombia. WSCPs were obtained by hot‐water extraction, ethanol precipitation, and dialysis and characterized using UV‐Vis spectroscopy, gel permeation chromatography, high‐performance liquid chromatography‐diode array detector, fourier transform infrared and nuclear magnetic resonance spectroscopy. Different assays evaluated the antioxidant capacity, and the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT)‐assay was used to determine cytotoxic effects. Chemical compositional analysis revealed that RFCP and RACP are heteropolysaccharides with molecular weights of 407 and 818 kDa, respectively compose mainly of glucose, mannose, galactose, fucose, and glucuronic acid with small amounts of protein and polyphenols. The backbone of RFCP and RACP is composed of β‐D‐Glcp‐(4→,→3)‐β‐D‐Glcp‐(1→,→2,6)‐α‐D‐Galp‐(1→,→3,6)‐α‐D‐Manp‐(1→. Antioxidant capacity demonstrated that both crude polysaccharides exhibit reducing power, radical scavenging ability, and a protective effect on lipid‐peroxidation. MTT assay showed that RFCP and RACP inhibited the growth of cancer cells HCT 116‐(colorectal) and MG‐63‐(bone) in a concentration‐dependent manner. Compared with RFCP, RACP showed better antioxidant capacity and cytotoxic effects due to differences in composition, molecular weight, and triple‐helical conformation. Overall, WSCPs exhibited a promising biological effect, highlighting the cultural, nutritional, and medicinal value of wild mushrooms.
Efficient Catalytic Degradation of Azo Dyes from Textile Wastewater by Nano and Micro Amorphous Alloys
Authors: Aslan Mikail , Kaya Abdulaziz , Eskalen Hasan , Kurşun Celal , Çeşme Mustafa , Gögebakan Musa 
Published: February 2024

AbstractAzo dyes are known to cause environmental pollution and freshwater contamination, posing carcinogenic risks to human health. Consequently, researchers have directed their attention towards studying effective methods for removing these dyes from textile effluent. Amorphous alloys have emerged as a promising candidate for enhancing degradation efficiency on azo dyes, with various metallic alloys undergoing extensive investigation. Notably, the novel catalytic metallic materials exhibit significantly higher degradation performance compared to traditional options. Among the promising candidates are nanometallic alloys based on Fe, Mg, Co, Al, and Mn, which offer improved potential for cleaning diverse types of azo dyes from wastewater. The purpose of this review is to provide an update of the research regarding the use of amorphous alloys in azo dye degradation. The different production methods of amorphous alloys were discussed. The amorphous alloys used in dye degradation studies were subcategorized into three main types: Fe‐based, Mg‐based and some miscellaneous‐based amorphous alloys. Additionally, the study delves into the impact of crucial parameters, such as solution pH and initial dye concentration, providing valuable insights for the efficient treatment of wastewater.
Separation of TiO2 and Fe2O3 from Indonesia Ilmenite Minerals and their Application as Photocatalysts for Eriochrome Black‐T Dye Degradation
Authors: Putri Reza Audina , Arutanti Osi , Wardhani Sri , Hanz Putri Badria , Tursiloadi Silvester 
Published: February 2024

AbstractAnatase‐TiO2 and α‐Fe2O3 were successfully separated from Indonesia ilmenite minerals using a modification of the hydrometallurgy process. Sodium salt was used as an initiated roasting before hydrochloric leaching. The study investigated parameters that affect separation such as mass ratios of sodium salt to ilmenite and leaching temperature. The results revealed that Ti composition in residue‐TiO2 increased to 76 % while Fe‐composition in filtrate‐Fe2O3 was 87 %. The XRD diffractogram analysis confirmed that main phase formed in residue of separation was anatase‐TiO2 whereas in hydrolysed of filtrate from separation was hematite. Both residue‐TiO2 and filtrate Fe2O3 had high thermal stability. The photocatalytic activity of anatase‐TiO2 and α‐Fe2O3 showed about 97 % and 85 % of Eriochrome Black‐T dye solution was degraded, respectively, when conducted to 4 hours of UV light irradiation. Photocatalytic kinetics study of anatase‐TiO2 and α‐Fe2O3 in degradation process followed pseudo‐first order with reaction rate at 0.0144 and 0.0070 min−1, respectively.
S‐Substituted Oxadiazoles: A Multi‐Faceted Approach to Synthesis, Enzyme Inhibition, and Antibacterial Properties
Authors: Siddiqui Sabahat Zahra , Abbasi Muhammad Athar , Aziz‐ur‐Rehman  , Solangi Mehwish , Ashraf Muhammad , Khan Khalid Mohammed 
Published: February 2024

AbstractAntibiotic resistance (AR) is one of the most serious global health issues today. Antibiotic abuse in the medical, veterinary, and agricultural industries, including incorrect antibiotic prescribing, overuse in the livestock industry, and poor cleanliness practices in hospitals, all contribute to the emergence of AR. Antibacterial drugs are derived from bacteria or molds or are synthesized de novo. In the present study, S‐substituted derivatives of 5‐(4‐methoxyphenyl)‐1,3,4‐oxadiazole‐2‐thiol (6 a‐p) were synthesized, fully characterized, and assessed for their inhibitory potential against various Gram‐negative and positive bacterial strains. The compounds demonstrated potent inhibition activity against all selected bacterial strains P. aeroginosa (−), E. coli (−), K. pneumonae (−), S. typhi (−), S. aureus (+), and B. subtilis (+) in comparison to standard ciprofloxacin drug. Among the synthesized derivatives, compounds 6 e and 6 o exhibited high selectivity and potency against the S. typhi (−) strain. The library 6 a‐o was also evaluated for in vitro chymotrypsin enzyme inhibitory activity, and all derivatives displayed weak inhibition potential in contrast to standard chymostatin (IC50 = 8.24±0.11 μM). Studies such as this one may aid in designing and discovering potential antibacterial agents for treating various bacterial infections.
Fischer indolization of terpenes and steroids
Authors: Kotha Sambasivarao , Meher Punam 
Published: February 2024

AbstractHere we report a new synthetic approach to several intricate indoles and hydrazones starting with commercially available terpenes and steroids via Fischer indolization (FI) sequence under deep eutectic solvents (DES) conditions or by employing acetic acid reflux conditions. During the course of the reaction with pulegone 22 and pipertone 25 we observed Fischer indolization along with aromatization is occurring. In another instance, with thujone 32 we found cyclopropane ring is opening under thermal conditions leading to aromatized Fischer indole product. We also studied the FI sequence of some diketo derivatives to synthesize the corresponding bis indole derivatives, but instead we obtained mono hydrazone derivative which can be explained on the basis of steric reasons. In addition, we also modified other terpenes to study the FI sequence where we realized the formation of both hydrazone and indole derivatives. All the compounds synthesized here are well characterized by NMR and HRMS data.
Recent Progress of Transition Metal Selenides for Electrochemical Oxygen Reduction to Hydrogen Peroxide: From Catalyst Design to Electrolyzers Application
Authors: Wang Yingnan , Han Caidi , Ma Li , Duan Tigang , Du Yue , Wu Jinting , Zou Ji‐Jun , Gao Jian , Zhu Xiao‐Dong , Zhang Yong‐Chao 
Published: February 2024

AbstractHydrogen peroxide (H2O2) is a highly value‐added and environmental‐friendly chemical with various applications. The production of H2O2 by electrocatalytic 2e− oxygen reduction reaction (ORR) has emerged as a promising alternative to the energy‐intensive anthraquinone process. High selectivity Catalysts combining with superior activity are critical for the efficient electrosynthesis of H2O2. Earth‐abundant transition metal selenides (TMSs) being discovered as a classic of stable, low‐cost, highly active and selective catalysts for electrochemical 2e− ORR. These features come from the relatively large atomic radius of selenium element, the metal‐like properties and the abundant reserves. Moreover, compared with the advanced noble metal or single‐atom catalysts, the kinetic current density of TMSs for H2O2 generation is higher in acidic solution, which enable them to become suitable catalyst candidates. Herein, the recent progress of TMSs for ORR to H2O2 is systematically reviewed. The effects of TMSs electrocatalysts on the activity, selectivity and stability of ORR to H2O2 are summarized. It is intended to provide an insight from catalyst design and corresponding reaction mechanisms to the device setup, and to discuss the relationship between structure and activity.
Trace Y Doping Regulated Bulk/Interfacial Reactions of P2‐Layered Oxides for Ultrahigh‐Rate Sodium‐Ion Batteries
Authors: Li Yong , Shi Qinhao , Yu Xuan , Ning Fanghua , Liu Guoliang , Wang Xuan , Wang Juan , Xu YunHua , Zhao Yufeng 
Published: February 2024

AbstractP2‐phase layered cathodes play a pivotal role in sodium‐ion batteries due to their efficient Na+ intercalation chemistry. However, limited by crystal disintegration and interfacial instability, bulk and interfacial failure plague their electrochemical performance. To address these challenges, a structural enhancement combined with surface modification is achieved through trace Y doping. Based on a synergistic combination of experimental results and density functional theory (DFT) calculations, the introduction of partial Y ions at the Na site (2d) acts as a stabilizing pillar, mitigating the electrostatic repulsions between adjacent TMO2 slabs and thereby relieving internal structural stress. Furthermore, the presence of Y effectively optimizes the Ni 3d‐O 2p hybridization, resulting in enhanced electronic conductivity and a notable rapid charging ability, with a capacity of 77.3 mA h g−1 at 40 C. Concurrently, the introduction of Y also induces the formation of perovskite nano‐islands, which serve to minimize side reactions and modulate interfacial diffusion. As a result, the refined P2‐Na0.65 Y0.025[Ni0.33Mn0.67]O2 cathode material exhibits an exceptionally low volume variation (≈1.99%), an impressive capacity retention of 83.3% even at −40 °C after1500 cycles at 1 C.
On the interaction between the search parameters and the nature of the search problems in search‐based model‐driven engineering
Authors: Roca Isis , Font Jaime , Arcega Lorena , Cetina Carlos 
Published: February 2024

AbstractThe use of search‐based software engineering to address model‐driven engineering activities (SBMDE) is becoming more popular. Many maintenance tasks can be reformulated as a search problem, and, when those tasks are applied to software models, the search strategy has to retrieve a model fragment. There are no studies on the influence of the search parameters when applied to software models. This article evaluates the impact of different search parameter values on the performance of an evolutionary algorithm whose population is in the form of software models. Our study takes into account the nature of the model fragment location problems (MFLPs) in which the evolutionary algorithm is applied. The evaluation searches 1895 MFLPs (characterized through five measures that define MFLPs) from two industrial case studies and uses 625 different combinations of search parameter values. The results show that the impact on the performance when varying the population size, the replacement percentage, or the crossover rate produces changes of around 30% in performance. With regard to the nature of the problems, the size of the search space has the largest impact. Search parameter values and the nature of the MFLPs influence the performance when applying an evolutionary algorithm to perform fragment location on models. Search parameter values have a greater effect on precision values, and the nature of the MFLPs has a greater effect on recall values. Our results should raise awareness of the relevance of the search parameters and the nature of the problems for the SBMDE community.
Preparation and characterization of vinyl silica‐supported surface molecularly imprinted polymers coupled with liquid chromatography‐mass spectrometry for extraction of prostaglandin analogs from cosmetic products
Authors: Shahzad Aqeel , Batool Farzana , Bashir Kamran , Xu Jiameng , Fu Qiang 
Published: February 2024

AbstractProstaglandin analogs (PGAs) are commonly used to treat ocular hypertension and glaucoma patients. Nowadays, the use of PGAs enhances eyelashes in cosmetics, particularly in the condition of hypotrichosis. A method was developed in which surface molecularly imprinted polymers were synthesized for selective extraction of PGAs (bimatoprost, latanoprost, and travoprost) by using bimatoprost as template molecules which were coupled with liquid chromatography‐mass spectrometry (LC‐MS) system. Scanning electron microscopy and Fourier‐transform infrared spectroscopy techniques were used to study the morphological and physical characterization. The adsorption selectivity studies showed the high selectivity of PGAs. The adsorption capacities of bimatoprost, latanoprost, and travoprost were 93.8, 92.3, and 91.5 μg/g, respectively. The recoveries and precision of samples at three concentration levels (10–30 ng/mL) of bimatoprost, latanoprost, and travoprost were tested (98.5%–102.5%, 1.2%–4.5%, n = 3). The % relative standard deviation for repeatability of the method for bimatoprost, latanoprost, and travoprost ranged from 1.8 to 5.6, 1.5 to 4.8, and 1.6 to 5.2, respectively. While the limit of detection for bimatoprost, latanoprost, and travoprost was 0.20, 0.25, and 0.45 ng/mL, respectively. The method of surface molecularly imprinted polymer coupled with LC‐MS was successfully applied to cosmetic products for selective extraction of PGAs.
A brief history of amyloid aggregation simulations
Authors: Fatafta Hebah , Khaled Mohammed , Kav Batuhan , Olubiyi Olujide O. , Strodel Birgit 
Published: February 2024

AbstractAmyloid proteins are characterized by their tendency to aggregate into amyloid fibrils, which are often associated with devastating diseases. Aggregation pathways typically involve unfolding or misfolding of monomeric proteins and formation of transient oligomers and protofibrils before the final aggregation product is formed. The conformational dynamics and polymorphic and volatile nature of these aggregation intermediates make their characterization by experimental techniques alone insufficient and also require computational approaches. Over the past 25 years, the size of simulated amyloid aggregation systems and the length of these simulations have increased significantly. These advances are discussed here. The review includes simulation approaches that model the aggregating peptides or proteins at both the all‐atom and coarse‐grained levels, use molecular dynamics simulations or Monte Carlo sampling to simulate the conformational changes, and present results for various amyloid peptides and proteins ranging from Lys‐Phe‐Phe‐Glu (KFFE) as the smallest system to as an intermediate‐sized peptide to α‐synuclein. The presentation of the history of amyloid aggregation simulations concludes with a discussion of where the future of these simulations may lie.This article is categorized under:
Structure and Mechanism > Computational Biochemistry and Biophysics
Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods