bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of impurities in the repurposed COVID‐19 drug hydroxychloroquine sulfate using ultra‐high‐performance liquid chromatography‐quadrupole/time‐of‐flight mass spectrometry and liquid chromatography‐solid‐phase extraction‐nuclear magnetic resonance
Authors: Xu Donghai , Pan Fangfang , Ruan Hao , Sun Nan 
Published: July 2022

RationaleHydroxychloroquine sulfate is effective in the treatment of malaria and autoimmune diseases and as an antiviral drug. However, unreported impurities are often detected in this drug, which pose a health risk. In this study, the structures of hydroxychloroquine and six unknown impurities were analyzed using ultra‐high‐performance liquid chromatography‐quadrupole/time‐of‐flight‐tandem mass spectrometry (UHPLC­Q/TOF/MS/MS), and the structures were characterized using liquid chromatography‐solid‐phase extraction‐nuclear magnetic resonance (LC‐SPE‐NMR) spectroscopy.MethodsAn Agilent InfinityLad Poroshell HPH‐C18 column (100 × 4.6 mm, 2.7 μm) was used. For the analysis of hydroxychloroquine and six unknown impurities, the mobile phase was 20 mM ammonium formate aqueous solution and methanol/acetonitrile (80:20, v/v) using gradient elution. Full‐scan MS and MS2 were performed to obtain as much structural information as possible. In addition, six unknown impurities were separated by semi­preparative liquid chromatography and characterized using LC‐SPE‐NMR.ResultsThe MS2 fragmentation patterns of the impurities were investigated, leading to more structural information and an understanding of the fragmentation pathways of the impurities. The structures of the unknown impurities were confirmed using NMR. In addition, some possible pathways of the formation of the impurities in the drugs were outlined, and these impurities were found to be process impurities.ConclusionsBased on the identification and characterization of these impurities, this study also describes the cause of the production of the impurities and provides insights for companies to improve their production processes and a scientific basis for the improvement of the related pharmacopoeias.
A high‐resolution mass spectrometric method for identification and characterization of the in vitro metabolites of senkyunolide H
Authors: Yan Yuqi , Chen Fengping , Zou Haizhu , Zhang Ping , Wu Xiaohua , Lin Mengying 
Published: July 2022

RationaleLigusticum chuanxiong Hort is a well‐known herb medicine that has been widely prescribed to treat cardiovascular diseases in China for hundreds of years. Senkyunolide H (SNH) is one of the major bioactive ingredients extracted from L. chuanxiong, and it displayed neuroprotective effects. To fully understand its mechanism of action, the metabolism needs to be investigated.MethodsIn vitro studies were conducted by incubating SNH with rat and human hepatocytes, and the metabolites were identified and characterized using liquid chromatography in combination with hybrid quadrupole Orbitrap mass spectrometry (LC‐Orbitrap‐MS). The structures of the metabolites were proposed by accurate mass analysis of respective precursor ions, indicative product ions, and elemental compositions.ResultsUnder the current conditions, a total of 10 metabolites were identified, and among these metabolites, M3 and M4 were the most abundant metabolites both in rat and human hepatocytes. Our results demonstrated that hydroxylation, hydration, glucuronidation, and GSH conjugation were the primary metabolic pathways of SNH.ConclusionsThe present study provides new information on the metabolism of SNH, which would help prospects of the disposition of SNH.
A systematic review of Indigenous parents' educational engagement
Authors: Sianturi Murni , Lee Jung‐Sook , Cumming Therese M. 
Published: July 2022

AbstractThe vital role of parents in Indigenous children's education has long been recognised in the school system; however, there is still limited understanding of the complex challenges experienced by parents in their educational engagement. This systematic review synthesised evidence from 41 studies to provide an understanding of Indigenous parents' perceptions about their educational engagement and strategies used by schools to facilitate their engagement. By employing a qualitative thematic synthesis, we identified three main themes: (1) the self‐perceived roles of Indigenous parents; (2) factors that hinder educational engagement; and (3) strategies that can support Indigenous parents. The findings suggest that cultural issues greatly influence the way parents perceive their role and are at the root of the hindering factors and effective strategies for increasing parental engagement. Schools' personnel can create opportunities for authentic collaboration with parents by undertaking a comprehensive identification of impeding factors and employing a strength‐based framework that acknowledges the importance of integrating cultural aspects and culturally responsive approaches.Context and implicationsRationale for this studyIndigenous parental engagement in schools has continued to be a concern. Although such engagement is widely recognised as essential, fundamental enablers of parental engagement are not thoroughly examined. This study aimed to explore how home‐school relations could be established in ways that accommodate the preferences of Indigenous parents.Why do the new findings matterThis study provides a comprehensive analysis of how home‐school partnerships could be undertaken to produce an authentic collaboration between schools and Indigenous parents. The findings contribute to the body of knowledge about the factors hindering Indigenous parental engagement and culturally responsive strategies to enhance it.Implications for practitioners and policy makersWith the recognition of Indigenous cultures, schools can strengthen their genuine commitments to build an authentic and inclusive collaboration with Indigenous parents by empowering parents to engage in their children‘s education, building culturally responsive relationships with parents, and supporting the whole family and students‘ development. Moreover, policy makers might comprehensively investigate any culturally inappropriate and unsafe regulations in the existing policies and consider holistic programmes that are more culturally responsive.
Length of labour using vaginal misoprostol or dinoprostone for induction at various gestational ages: A retrospective cohort study
Authors: Boyd Victoria E. , Mackeen A. Dhanya , Young Amanda J. , Johns Alicia , Lewis Meredith W. , Paglia Michael J. 
Published: July 2022

AbstractIntroductionInduction of labour is a common procedure performed on labour and delivery. There are multiple ways to achieve cervical ripening, however, no studies have evaluated these methods based on a patient's gestational age. The goal of this study is to compare the length of labour at specific gestational ages in women being induced with either vaginal misoprostol or the dinoprostone insert.MethodsA retrospective cohort study of 3774 singleton pregnancies from 2009 to 2019 at a health system with tertiary care and community hospitals was conducted. The primary outcome was time to insertion of medication to time to vaginal delivery. Secondary outcomes included length of first and second stages of labour, length of rupture of membranes, mode of delivery, neonatal Apgar scores at 1 and 5 min and neonatal intensive care unit admission. A generalized linear model was utilised for continuous outcomes and a logistic regression model was used for binary outcomes.ResultsAcross all gestational ages, women who received vaginal misoprostol had a shorter labour course than women who received dinoprostone (in hours, preterm 18.2 vs. 26.3 p < 0.01, term 15.9 vs. 24.4 p < 0.01, late term 17.6 vs. 22.3 p < 0.01). Patients that received misoprostol had a shorter first stage of labour (in hours, preterm 18.2 vs. 25.7 p < 0.01, term 15.3 vs. 23.6 p < 0.01, late term 16.5 vs. 21.1 p < 0.01) and second stage of labour in the term and late term group (term 20.5 vs. 30.0 min. p < 0.01, late term 30.0 vs. 47.0, p = 0.05). Patients that received dinoprostone at term had higher odds of undergoing caesarean section (odds ratio (95% confidence interval): 1.34 (1.06, 1.70)).ConclusionPatients that received vaginal misoprostol was associated with shorter labour course across all gestational ages. Patients that received dinoprostone at term had an increased risk of caesarean section.
Asymptotic enumeration of digraphs and bipartite graphs by degree sequence
Authors: Liebenau Anita , Wormald Nick 
Published: July 2022

AbstractWe provide asymptotic formulae for the numbers of bipartite graphs with given degree sequence, and of loopless digraphs with given in‐ and out‐degree sequences, for a wide range of parameters including the biregular case. In particular, for bipartite graphs with part sizes that are not highly unequal, our results cover an existing gap in known results between the sparse and dense cases that were proved by Greenhill, McKay, and Wang in 2006 and by Canfield, Greenhill, and McKay in 2008, respectively. For the range of parameters which our results cover, they imply that the degree sequence of a random bipartite graph with edges and given part sizes is accurately modeled by a sequence of independent binomial random variables, conditional upon the sum of variables in each part being equal to . This extends the known behavior in the sparse and dense cases to essentially the full spectrum of possible densities. A similar model also holds for loopless digraphs.
Joint parameter estimation and decoding in a distributed receiver
Authors: Waqas Ahsan , Nguyen Khoa , Lechner Gottfried , Chan Terence 
Published: July 2022

SummaryThis paper presents an algorithm for iterative joint channel parameter (carrier phase, Doppler shift, and Doppler rate) estimation and decoding of transmission over channels affected by Doppler shift and Doppler rate using a distributed receiver. This algorithm is derived by applying the sum‐product algorithm (SPA) to a factor graph representing the joint a posteriori distribution of the information symbols and channel parameters given the channel output. In this paper, we present two methods for dealing with intractable messages of the SPA. In the first approach, we use particle filtering with sequential importance sampling for the estimation of the unknown parameters. We also propose a method for fine‐tuning of particles for improved convergence. In the second approach, we approximate our model with a random walk phase model, followed by a phase tracking algorithm and polynomial regression algorithm to estimate the unknown parameters. We derive the Weighted Bayesian Cramer‐Rao Bounds for joint carrier phase, Doppler shift, and Doppler rate estimation, which take into account the prior distribution of the estimation parameters and are accurate lower bounds for all considered signal‐to‐noise ratio values. Numerical results (of bit error rate and the mean‐square error of parameter estimation) suggest that phase tracking with the random walk model slightly outperforms particle filtering. However, particle filtering has a lower computational cost than the random walk model‐based method.
Novel Thiazolotriazolone Derivatives: Design, Synthesis, In Silico Investigation, Analgesic and Anti‐inflammatory Activity
Authors: Almasirad Ali , Sani Parvane Sadat Vafaei , Mousavi Zahra , Fard Gholamreza Behnami , Anvari Taha , Farhadi Maryam , Vosooghi Mohsen , Azizian Homa 
Published: July 2022

AbstractA group of new thiazolo[3,2‐b][1,2,4]triazol‐6(5H)‐one fenamate‐like derivatives designed by using hybrid strategy in order to explore analgesic/anti‐inflammatory activity of the hybrid structures. Some of the synthesized analogs showed comparable activities with mefenamic acid in abdominal constriction test and carrageenan induced rat paw edema test. 5‐(4‐nitrobenzylidene)‐2‐(2‐(2‐chlorophenoxy)phenyl)thiazolo[3,2‐b][1,2,4]triazol‐6(5H)‐one (8 e) and 5‐(3,5‐di‐tert‐butyl‐4‐hydroxybenzylidene)‐2‐(2‐(2‐chlorophenoxy)phenyl)thiazolo[3,2‐b][1,2,4]triazol‐6(5H)‐one (8 k) were determined as the most active agents with 53.1 and 49.3 percent of inhibition after 4 hrs of ip administration respectively. Flexible docking investigation indicated that the designed molecules interacted with cyclooxygenase 1 and 2 (COX‐1 and COX‐2) active sites. Moreover, the results suggest that thiazolo[3,2b][1,2,4]triazol‐6(5H)‐one moiety has the same effect as mefenamic acid COOH group over COX‐1,2 with a significant low or no ulcerogenic activity. Furthermore, the energetically favorable conformer Z, revealed as the active structural conformation due to the less steric hindrance. Based on the predicted ADME properties of high potent anti‐inflammatory agents, it is proposed that the applied modifications promote the rational drug design of novel analgesic and anti‐inflammatory candidates.
Iodine‐Catalyzed Oxidative Coupling of Indolin‐2‐ones with Indoles: Synthesis of 3,3‐Disubstituted Oxindole Compounds
Authors: Li Ruo‐Pu , Wang Zheng‐Lin , Zhang Yun‐Hao , Tan Zhi‐Yu , Xu Da‐Zhen 
Published: July 2022

AbstractThe construction of all‐carbon quaternary centers via cross‐dehydrogenative coupling reaction remains a challenging issue. Here we describe an I2‐catalyzed C(sp3)−H arylation for the construction of all‐carbon quaternary centers. The method performed under metal‐free and peroxide‐free conditions, providing 3,3‐disubstituted oxindoles via two C−C bond formations from secondary C(sp3)−Hs in a straightforward manner.
Promising N, P Co‐doped Porous Carbon Materials as Metal‐Free Electrocatalyst for Oxygen Reduction Reaction in Alkaline Medium
Authors: Barman Jayshree , Deka Namrata , Rudra Siddheswar , Dutta Gitish K. 
Published: July 2022

AbstractDeveloping an efficient metal‐free electrocatalyst to compete with the noble metal‐based catalysts for oxygen reduction reaction (ORR) is of great significance in the field of energy storage and conversion. We have designed a metal‐free electrocatalyst via dual doping of nitrogen and phosphorus in a porous carbon structure from a cyclotripolyphosphazene (CTP)‐based polymer. The optimized material (CTP‐800) demonstrates an excellent ORR catalytic performance with an onset potential of 0.89 V, a high limiting current density of 4.58 mA cm−2, and a favorable 4‐electrons mediated reaction mechanism in the KOH electrolyte. Moreover, the electrochemical stability, as well as methanol compatibility of CTP‐800, are superior to the commercially available Pt/C catalyst. The remarkable electrocatalytic performance of CTP‐800 can be credited to the high surface area with rich micropores/mesopores and homogenous distribution of heteroatoms.
A Seven‐Membered Zirconacyclocumulene Complex as a source of Cyclobutadiene: Trapping of Cyclobutadiene by the Diels‐Alder Reaction
Authors: Andreev Maxim V. , Bogdanov Vyacheslav S. , Frolov Mikhail A. , Smol'yakov Alexander F. , Burlakov Vladimir V. 
Published: July 2022

AbstractThe interaction of the seven‐membered zirconacyclocumulene complex of zirconocene with acenaphthenequinone leads to the cyclobutadiene formation with its subsequent dimerization in cyclooctatetraene in addition to tetraoxadizirconacycle consists of two zirconocene and two acenaphthenequinone fragments. If this reaction is carried out in the presence of the excess of cyclopentadiene or acenaphthylene, the trapping of cyclobutadiene by the Diels‐Alder reaction takes place. Cyclobutadiene can act both as dienophile and diene source in these reactions.
Imide‐Based Covalent Organic Frameworks/Carbon Nanotube Composites as Anode Materials for Potassium Storage
Authors: Pei Bo , Liu Dandan , Tian Zhihong , Huang Jiajia 
Published: July 2022

AbstractFew organic materials have been reported as anode materials for potassium‐ion batteries (KIBs), because of its partial dissolving in organic electrolyte. Covalent organic frameworks (COFs) with the framework structure and functional organic units can prevent the dissolution of organic electrodes in organic electrolyte to some extent. Herein, PI‐NTCDA@CNT was synthesized via PI‐NTCDA controlled growth of on a carbon nanotube (CNT) for using as anode materials for KIBs. It can achieve a specific capacity of 135.5 mAh g−1 at the current density of 0.1 A g−1. Notably, PI‐NTCDA@CNT also exhibits outstanding long‐term reversible capacity of 79.5 mAh g−1 after 1000 cycles at current density of 0.1 A g−1, which shows a negligible capacity loss of 0.04 % per cycle.
Preparation of Ni/Ce Composite Photocatalytic CO2 Heterojunction by Treating Electroplating Nickel Wastewater
Authors: Lin Shengnan , Zhang Tingan , Xu Taiyu , Fuyang Chengzhen 
Published: July 2022

AbstractIn the past few years, it was discovered that Ni(OH)2 is an effective photocatalyst for CO2 as a chemical fuel catalyst. Ni(OH)2 nanosheets were prepared by simple wet treatment and electric transformation of nickel‐containing wastewater. The Ni(OH)2/Ce(OH)4 hybrid nanosheets were prepared by Ce doping experiment, and Ni/Ce oxide was prepared by calcination with Ni(OH)2/Ce(OH)4 composite nanosheets. Finally, Ce(OH)4 was prepared by electroconversion with CeCl3 ⋅ 7H2O as raw material, and all the samples were used as CO2 photocatalysts for performance comparison. The diameter and thickness of Ni(OH)2/Ce(OH)4 and NiO/CeO2 nanocrystals are about 1∼50 nm and 1∼10 nm, respectively. The BET‐specific surface area is calculated to be 205.93 m2/g (Ni(OH)2/Ce(OH)4) and 18.93 m2/g (NiO/CeO2). During CO2 photoreduction, bare Ce(OH)4 can only produce CO (1.32 μmol after 4 h). The methane yield of Ni(OH)2/Ce(OH)4 is 11.435 μmol after 4 h, while the CO yield increases to 21.515 μmol after 4 h. Compared with the oxide NiO/CeO2, the electrolytic product Ni(OH)2/Ce(OH)4 showed a higher photocatalytic activity for CO2 reduction, which is attributed to the larger specific surface area of the precursor. We believe this work provides a potential approach for treating nickel‐containing electroplating wastewater to prepare highly efficient and selective CO2 reduction photocatalysts.
Green Catalysts in the Synthesis of Biopolymers and Biomaterials
Authors: Chafran Liana , Matias Ana Elisa , Silva Luciano Paulino 
Published: July 2022

AbstractThe modernization processes of the chemical industry over the last few years reinforce concerns about the sustainable use of natural resources and the synthesis of solvent‐free and low toxicity products. Additionally, the development of new catalysts capable of minimizing or even eliminating hazardous substances commonly used in the chemical industry has received increasing attention in the academic and industrial environments within the context of Green Chemistry, based on the search for products and processes capable of reducing or even eliminating the use of hazardous substances. This need becomes even greater when it comes to the synthesis and modification of biopolymers with great applicability in the biomedical field such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(caprolactone) (PCL) in addition to acrylate‐based polymers. The present review aims to discuss the major classes of green catalysts and biocatalysts, their main characteristics, and different synthetic routes. To emphasize the importance of green catalysts in the biomedical industry, different synthetic routes are discussed to obtain biopolymers and biomaterials whose different degradation products have low or no environmental impact, and whose yield rate, degradability, and selectivity are controlled by presence of a catalyst.
The Complexation between Siloxane Species and Methylsiloxane: Electronic Structure, Thermodynamic, and Interaction Characteristics
Authors: Niu Wenxia , Li Peng 
Published: July 2022

AbstractThe interaction between organosiloxane materials and siloxane species has attracted extensive attention in the protection of cultural relics due to their bonding characteristics. In this context, detailed studies of the complexation between siloxane species and methylsiloxane were explored using various computational methods. The complex molecular structures and their electronic excitation characteristics were predicted. The strong covalent interactions of Si−O bond between siloxane and methylsiloxane are checked by topological analysis of electron density and obvious charge transfer. Thermodynamic results show that these types of complexes are considerable stability. The energy barrier of oxygen molecules to pass through the pores between methylsiloxane and silica close to 19 eV, indicating that this type of coating does not peel off easily. Moreover, IR and UV‐vis spectrum were predicted. The microscopic mechanism will give theoretical direction for theoretical guidance for practical applications of the coating in the protection of stone artifacts.
Selectively Imprinted β‐cyclodextrin Polymer for Colorimetric Assay of Lysophosphatidic Acid for Point of Care Detection of Ovarian Cancer
Authors: Tarannum Nazia , Kumar Deepak , Agrawal Ranu , Verma Yeshvandra 
Published: July 2022

AbstractIn the present study, a simple molecular imprinting technique for the quantitative measurement of lysophosphatidic acid (LPA) is reported for the first time through colorimetry. LPA is a phospholipid bioactive involved in many physiological and pathological processes like stimulating DNA synthesis, proliferating ovarian cancer and inducing cell migration. It is reported that the concentration of LPA in patients with gynecological cancers like ovarian cancer is considerably higher than in the control. The early diagnosis of ovarian cancer may exceed the survival rate of patients. There is a need for an analytical tool for point of care detection of ovarian cancer at an early stage. Herein, molecular imprinting technique is used to develop an imprinted β‐Cyclodextrin (β‐CD) polymer using LPA as a template. This MIP prepared was imprinted with an LPA cavity, which has been extended for colorimetry assay. The colorimetric LPA assay was conducted in the spiked blood serum sample. The detection limit of LPA in spiked serum samples is calculated as 0.078 μmol/L.
Enhancing and securing cyber‐physical systems and Industry 4.0 through digital twins: A critical review
Authors: Lampropoulos Georgios , Siakas Kerstin 
Published: July 2022

AbstractDue to the fierce competitive global market, enterprises need to face and overcome new challenges and requirements to stay ahead of competition. Cyber‐physical systems, Internet of things, and digital twins are some of the contemporary technologies that are used in the context of Industry 4.0 in order to instill intelligence into the industrial sector by changing traditional manufacturing to smart manufacturing. The digitalized and interconnected nature of Industry 4.0 creates new security, privacy, and safety challenges that need to be addressed in order for it to be fully realized. This study presents an overview regarding the use of digital twins as a means to reinforce and secure cyber‐physical systems and Industry 4.0, in general. Digital twins connect the physical and virtual worlds and can be used in combination with other technologies to provide several merits in various sectors, such as real‐time monitoring and controlling, prompt access to dynamic data, constant visualization and analysis, process optimization, advanced decision‐making, and prediction systems. All in all, based on the literature review, digital twins can constitute an essential tool for the realization, reinforcement, and security of cyber‐physical systems and Industry 4.0.