bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses of 6,7‐Benzotropolone by Using Ring‐Closing Metathesis Variants Obviating a Strongly Acidic Hydrolysis Thereafter
Authors: Koblischek Philip , Brückner Reinhard 
Published: October 2021

AbstractA Wittig reaction of 3‐hydroxyphtalide (11) gave ortho‐styrene‐2‐carboxylic acid (12). Its Weinreb amide 13 acylated heterosubstituted methyllithiums. This led to aryl “methyl” ketones whose sp3‐carbon was substituted by Cl+OMe (in 14 a), 2×Cl (in 14 b), OtBu (in 17 a), SPh (in 17 b) or SO2Ph (in 17 c). The enolates of these ketones were C‐allylated. This furnished the benzene‐fused nona‐1,8‐dienones 7 a–b and 9 a–c, respectively. Ring‐closing metatheses provided the corresponding benzocycloheptadienones 8 a‐b and 10 a–c. Their ketone moieties were α,α‐disubstituted (in 8 a–b) or α‐monosubstituted (in 10 a–c). Each substitution pattern allowed to generate the hydroxyenone motif of the corresponding benzocycloheptatrienone—or 6,7‐benzotropolone—6 a: The MeO‐ and PhS‐containing benzocycloheptadienone 8 a gave 6,7‐benzotropolone methyl ether (15) by sulfoxide formation and pyrolysis; 15 was demethylated with BCl3. The same intermediate resulted from the dichlorobenzocycloheptadienone 8 b and NaOMe. The benzocycloheptadienone 10 a was de(tert‐butylated) with formic acid; a subsequent Pfitzner‐Moffatt oxidation completed 6,7‐benzotropolone (6 a) once more. The PhS‐containing benzocycloheptadienone 10 b was α‐acetoxylated with Pb(OAc)4; the resulting O,S‐acetal gave 6,7‐benzotropolone (6 a) by hydrolysis. The PhSO2‐containing substrate 10 c was deprotonated whereupon an oxidation with Me3Si−O−O−SiMe3 gave 6,7‐benzotropolone (6 a).
Fe3O4 Nanorods‐RGO‐ionic Liquid Nanocomposite Based Electrochemical Sensor for Aflatoxin B1 in Ground Paprika
Authors: Chokkareddy Rajasekhar , Redhi Gan G. 
Published: October 2021

AbstractA novel and sensitive method for the determination of aflatoxin B1 (AFA−B1) in ground paprika using a methyltrioctylammonium chloride ionic liquid (IL), iron oxide nanorods (Fe3O4 nanorods) and reduced graphene oxide (RGO) fabricated glassy carbon electrode (GCE) was developed. The synthesized nanoparticles, nanocomposites and modified electrode surfaces were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA/DSC) and x‐ray diffraction (XRD) analyses. Moreover, the electrochemical performance of the developed sensor was determined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results demonstrate that the sensitivity of AFA−B1 is significantly enhanced on RGO‐Fe3O4 nanorods‐IL‐GCE in comparison with bare GCE, RGO‐GCE and RGO‐Fe3O4 nanorods‐GCE. The redox peak currents of AFA−B1 exhibited good linear relationship with its concentration in the range from 0.02 to 0.33 ng mL−1 with detection limit of (LOD) 0.03 ng mL−1 and limit of quantification (LOQ) 0.36 ng mL−1 respectively (S/N=3). In addition, the fabricated electrode showed good stability and reproducibility. The proposed technique was effectively applied to identify the AFA−B1 in real ground paprika samples with acceptable results.
Maternal eating disorder severity is associated with increased latency of foetal auditory event‐related brain responses
Authors: Doersam Annica Franziska , Moser Julia , Throm Jana , Weiss Magdalene , Zipfel Stephan , Micali Nadia , Preissl Hubert , Giel Katrin Elisabeth 
Published: October 2021

AbstractObjectiveMaternal eating disorders (EDs) are associated with adverse pregnancy and child outcomes. There is limited research investigating the influence of maternal EDs on foetal brain development.MethodUsing foetal magnetoencephalography (fMEG), an auditory sequence was presented for 10 min to assess brain response latencies in foetuses of mothers with (n = 12) and without (n = 11) a history of anorexia nervosa (AN) in the third trimester of pregnancy. ED history and severity were assessed using the structured clinical expert interview eating disorder examination (EDE) and the self‐report questionnaire EDE‐Q.ResultsFoetuses of mothers with AN showed delayed foetal brain responses to auditory stimulation compared to foetuses of control women. Self‐reported ED symptom severity explained 34% of variance in foetal brain response latencies in the AN group.ConclusionsED pathology was strongly associated with foetal brain response latencies in the third trimester with longer latencies in foetuses of women with a history of AN reporting more ED symptoms. Follow‐up on the children is pivotal to investigate if fMEG outcomes are associated with later child development.
Long‐term optimal power generation pathways for Pakistan
Authors: Abbasi Sikander Ali , Harijan Khanji , Khan Muhammad Waris Ali , Mengal Abdullah , Shaikh Faheemullah , Memon Zubair Ahmed , Mirjat Nayyar Hussain , Kumar Laveet 
Published: October 2021

AbstractPakistan has faced an electricity shortfall for over two decades despite various efforts taken at different levels. Though electricity supply in recent times has crossed the demand, the supply‐side stresses and deciding optimal power generation pathways have always been a challenge for policymakers and researchers. In this study using a LEAP energy model, following the sectoral electricity demand forecast, four supply‐side scenarios have been developed and analyzed for the study period 2017‐2055. In each scenario, referred to as Business as Usual (BAU), Renewable Energy Technologies (RET), Coal Power Penetration (CPP), and High‐Efficiency Low‐Emission (HELE) scenario, electricity generation, installed generation capacity, cost of production, and GHG emissions are estimated and compared for seeking long‐term optimal energy pathways for Pakistan. The study results reveal that for the end year (2055), RET is an environmentally sustainable scenario with an estimated electricity generation of 2421 TWh, which is enough to meet the electricity demand of 2374TWh. The GHG emissions under the RET scenario are estimated to be 857 million metric Tons, which are around 50% less than CPP and 40% less than the BAU scenario. However, the cost of generation is higher than BAU and CPP scenarios. The CPP scenario emerges to be cost‐competitive, however with the highest GHG emissions. This study thus suggests that convergence of RET with the CPP scenario could be an appealing option for Pakistan to meet increasing demand with energy security and environmental sustainability.
The Eco-Exposome Concept: Supporting an Integrated Assessment of Mixtures of Environmental Chemicals
Authors: Scholz Stefan , Nichols John W. , Escher Beate I. , Ankley Gerald T. , Altenburger Rolf , Blackwell Brett , Brack Werner , Burkhard Lawrence , Collette Timothy W. , Doering Jon A. , Ekman Drew , Fay Kellie , Fischer Fabian , Hackermüller Jörg , Hoffman Joel C. , Lai Chih , Leuthold David , Martinovic-Weigelt Dalma , Reemtsma Thorsten , Pollesch Nathan , Schroeder Anthony , Schüürmann Gerrit , von Bergen Martin 
Published: October 2021

Abstract
Organisms are exposed to ever-changing complex mixtures of chemicals over the course of their lifetime. The need to more comprehensively describe this exposure and relate it to adverse health effects has led to formulation of the exposome concept in human toxicology. Whether this concept has utility in the context of environmental hazard and risk assessment has not been discussed in detail. In this Critical Perspective, we propose—by analogy to the human exposome—to define the eco-exposome as the totality of the internal exposure (anthropogenic and natural chemicals, their biotransformation products or adducts, and endogenous signaling molecules that may be sensitive to an anthropogenic chemical exposure) over the lifetime of an ecologically relevant organism. We describe how targeted and nontargeted chemical analyses and bioassays can be employed to characterize this exposure and discuss how the adverse outcome pathway concept could be used to link this exposure to adverse effects. Available methods, their limitations, and/or requirement for improvements for practical application of the eco-exposome concept are discussed. Even though analysis of the eco-exposome can be resource-intensive and challenging, new approaches and technologies make this assessment increasingly feasible. Furthermore, an improved understanding of mechanistic relationships between external chemical exposure(s), internal chemical exposure(s), and biological effects could result in the development of proxies, that is, relatively simple chemical and biological measurements that could be used to complement internal exposure assessment or infer the internal exposure when it is difficult to measure. Environ Toxicol Chem 2022;41:30–45. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Abstract
Illustration of the eco-exposome assessment and how chemical analysis and bioassays could be used to estimate internal exposure. MIE = molecular initiation event; KE = key event; AO = adverse outcome.
Realized bipower variation, jump components, and option valuation
Authors: Pan Zhiyuan , Wang Yudong , Liu Li 
Published: October 2021

AbstractWe develop a new option pricing model that captures the jump dynamics and allows for the different roles of positive and negative return variances. Based on the proposed model, we derive a closed‐form solution for option pricing under the condition of a nonmonotonic pricing kernel. Our results indicate that the new model has superior option pricing performance to its nested models, including the jump model of Christoffersen et al. (2015) and affine realized semivariance model of Feunou and Okou (2019). The models accommodating jumps, high‐frequency information, and accounting for variance risk premium perform well compared with traditional benchmark models.
Origin of high‐Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite
Authors: Zhan Mingjun , Zhang Guoliang 
Published: October 2021

Andesitic to rhyolitic arc volcanism commonly occurs in the cold subduction system in the modern western Pacific, however, their genesis remains debated. The high‐Mg andesitic arc rocks with enrichments of Th and K are suggested to be derived from a contribution of the subducted sediments and the depleted mantle wedge. The partial melts of pure sediments have MgO too low to explain the origin of such high‐Mg arc rocks. For a cold subduction system, melting of subducted slab can unlikely occur, while sediment diapirism serves as a possible mechanism to contribute to the origin of arc volcanism. Here, we conducted high‐pressure experiments on the mixed sediment (±CaCO3) and peridotite with proportions of 7:3 and 5:5 at 3.5 GPa and 1000–1300°C. The experiment resulted in andesitic to rhyolitic melts with elevated MgO and enriched K2O. All melts reduce in K2O with increasing temperatures as no K‐rich minerals were produced. The interactions between carbonate‐bearing sediments and peridotites during the diapirism promote decarbonation and produce melts with elevated MgO. The results of the experiments can explain the origin of high‐Mg and K‐rich andesite‐rhyolite series of the Izu‐Bonin‐Mariana arc system. A higher sediment proportion used in the experiment is coupled with a stronger effect of garnet, which explains the volcanic rocks with higher K2O and La/Yb. We propose that sediment diapirism in the mantle wedge can produce high‐Mg and K‐rich andesitic‐rhyolitic arc lavas and facilitate decarbonation of subducted sedimentary carbonates in the typical cold Izu‐Bonin‐Mariana subduction zone.
Effective hydrolysis of polysaccharides by activated attapulgite
Authors: Yang Fengli , Xia Feifei , Gong Jie , Zheng Chunzhi 
Published: October 2021

AbstractBACKGROUNDHydrolysis of polysaccharides is a key step in biorefineries processes. In this study, an economic and green approach was developed to hydrolyze soluble polysaccharides (starch, inulin, etc.) into monosaccharides by a natural clay of attapulgite (ATP) modified with H2SO4(ATPS), and the catalysts were characterized by Fourier Transform Infrared Spectroscopy (FT‐IR), Pyridine FTIR Spectroscopy (pyridine‐FTIR), Temperature Programmed Desorption of Ammonia (NH3‐TPD), Thermo‐Gravimetric/Differential Thermal Analyze (TG‐DTA). The hydrolysis of different substrate over ATP‐S was evaluated.RESULTSAfter H2SO4 modification, the total acid sites of the catalyst ATP‐S increased from 65.33 to 109.46 umol g–1, and the surface area also increased from 81.4 to 137.3 m2 g–1. ATP‐S shows excellent activity and stability for polysaccharides hydrolysis in aqueous system. As for inulin as reactant, 98.5% of hydrolysis ratio was obtained at the moderate temperature of 95 °C for 210 min, and 75.8% hydrolysis ratio was achieved for starch. More importantly, there is no apparent decline of the catalytic activity after 4 recycles in aqueous system. In addition, the kinetic analysis was carried out, and the activation energy of the substrates were calculated.CONCLUSIONCompared with other hydrolysis processes involving enzymes and homogeneous catalysis, the process in this paper is more cost‐efficient and environmentally friendly, and it can easily be scaled‐up and implemented in chemical and bio‐based industries. © 2021 Society of Chemical Industry (SCI).
Distribution of antiretroviral therapy through private pharmacies and postal courier services during COVID‐19 in Botswana: acceptability and reach of two out‐of‐facility individual differentiated service delivery models
Authors: Mpofu Mulamuli , Moyo Tackler , Gilbert Masego , Dikobe Wame , Nishimoto Lirica , Katiko Gorata , Batuka James , Satti Hind , Qambayot Maria , Mahler Hally , Kitso Lesego , Marqusee Hannah , Bateganya Moses 
Published: October 2021

AbstractIntroductionThe advent of COVID‐19 has put pressure on health systems as they implement measures to reduce the risk of transmission to people living with HIV (PLHIV) and healthcare workers. For two out‐of‐facility individual differentiated service delivery (DSD) models, we assessed acceptability of antiretroviral therapy (ART) distribution through private pharmacies and reach of home delivery of ART through courier services during the COVID‐19 pandemic in Botswana.MethodsFrom 24 July to 24 August 2020, we conducted exit interviews with PLHIV receiving ART from 10 high‐volume public facilities in Gaborone, and mapped and conducted an online survey with private pharmacies to assess willingness and capacity to dispense ART to PLHIV enrolled in the Botswana national ART program. We piloted ART home delivery from September 2020 to January 2021 in Gaborone and Kweneng East districts for PLHIV accessing ART at two Tebelopele Wellness Clinics. We used cascade analysis to measure the enrolment and eventual reach (percentage of those reached amongst those who are eligible) of ART home delivery.ResultsSixty‐one PLHIV and 42 private pharmacies participated. Of the PLHIV interviewed, 37 (61%) indicated willingness to access ART from private pharmacies and pay BWP50 (∼US$4) per refill for a maximum of two refills per year. All private pharmacies surveyed were willing to provide ART, and 26 (62%) would charge a dispensing fee (range = BWP50–100; ∼US$4–8) per refill. All pharmacies operated 12 h/day, 6 days/week and on public holidays. In the home delivery pilot, 650 PLHIV were due for refills, 69.5% (n = 452) of whom were eligible for home delivery. Of these, 361 were successfully offered home delivery and 303 enrolled (enrolment = 83.9%: female = 87.2%, male = 77.8%, p = 0.013). A total of 276 deliveries were made, a reach of 61%.ConclusionsProviding ART through private pharmacies and home delivery was acceptable in Botswana during COVID‐19. Surveyed pharmacies were willing and able to dispense ART to PLHIV attending public sector facilities for free or for a nominal fee. Additionally, using courier services for ART home delivery is a novel and viable model in countries with a reliable courier service like Botswana and should be scaled up, particularly in urban areas.
Community‐based differentiated service delivery models incorporating multi‐month dispensing of antiretroviral treatment for newly stable people living with HIV receiving single annual clinical visits: a pooled analysis of two cluster‐randomized trials in southern Africa
Authors: Fatti Geoffrey , Ngorima‐Mabhena Nicoletta , Tiam Appolinaire , Tukei Betty Bawuba , Kasu Tonderai , Muzenda Trish , Maile Khotso , Lombard Carl , Chasela Charles , Grimwood Ashraf 
Published: October 2021

AbstractIntroductionDifferentiated service delivery (DSD) models for HIV treatment decrease health facility visit frequency and limit healthcare facility‐based exposure to severe acute respiratory syndrome coronavirus 2. However, two important evidence gaps include understanding DSD effectiveness amongst clients commencing DSD within 12 months of antiretroviral treatment (ART) initiation and amongst clients receiving only single annual clinical consultations. To investigate these, we pooled data from two cluster‐randomized trials investigating community‐based DSD in Zimbabwe and Lesotho.MethodsIndividual‐level participant data of newly stable adults enrolled between 6 and 12 months after ART initiation were pooled. Both trials (conducted between August 2017 and July 2019) had three arms: Standard‐of‐care three‐monthly ART provision at healthcare facilities (SoC, control); ART provided three‐monthly in community ART groups (CAGs) (3MC) and ART provided six‐monthly in either CAGs or at community‐distribution points (6MC). Clinical visits were three‐monthly in SoC and annually in intervention arms. The primary outcome was retention in care and secondary outcomes were viral suppression (VS) and number of unscheduled facility visits 12 months after enrolment. Individual‐level regression analyses were conducted by intention‐to‐treat specifying for clustering and adjusted for country.Results and DiscussionA total of 599 participants were included; 212 (35.4%), 128 (21.4%) and 259 (43.2%) in SoC, 3MC and 6MC, respectively. Few participants aged <25 years were included (n = 32). After 12 months, 198 (93.4%), 123 (96.1%) and 248 (95.8%) were retained in SoC, 3MC and 6MC, respectively. Retention in 3MC was superior versus SoC, adjusted risk difference (aRD) = 4.6% (95% CI: 0.7%−8.5%). Retention in 6MC was non‐inferior versus SoC, aRD = 1.7% (95% CI: −2.5%−5.9%) (prespecified non‐inferiority aRD margin −3.25%). VS was similar between arms, 99.3, 98.6 and 98.1% in SoC, 3MC and 6MC, respectively. Adjusted risk ratio's for VS were 0.98 (95% CI: 0.92−1.03) for 3MC versus SoC, and 0.98 (CI: 0.95−1.00) for 6MC versus SoC. Unscheduled clinic visits were not increased in intervention arms: incidence rate ratio = 0.53 (CI: 0.16−1.80) for 3MC versus SoC; and 0.82 (CI: 0.25−2.79) for 6MC versus SoC.ConclusionsCommunity‐based DSD incorporating three‐ and six‐monthly ART refills and single annual clinical visits were at least non‐inferior to standard facility‐based care amongst newly stable ART clients aged ≥25 years.ClinicalTrials.gov: NCT03238846 & NCT03438370
Crossover of resources within formal ties: How job seekers acquire psychological capital from employment counselors
Authors: Schmidt Corinna Vera Hedwig , Flatten Tessa Christina 
Published: October 2021

SummaryUnemployed job seekers experience stress which impedes their job search. Research suggests that psychological capital is a key resource which enables job seekers to cope with their stress. Yet it is still unclear how they acquire this key resource. During job search, job seekers engage in task‐oriented, infrequent interactions with counselors in employment agencies and establish formal ties. We explore these largely neglected formal ties and draw on conservation of resources theory and the crossover model to show that psychological capital crosses over from counselors to job seekers. We examine 209 dyads collected from two sources—counselors and job seekers—in an employment agency in Germany. Our hierarchical linear modeling results support the crossover of psychological capital within formal ties: Our results indicate that counselors' psychological capital impacts job seekers' psychological capital, which in turn lowers their stress. This relationship is mediated by job seekers' perception of counselors' social support. This study advances research on job loss and the crossover model as it explains the transfer of key resources within an institutional context characterized by formal ties, and it reveals social support as underlying mechanism. The practical implication is that counselors serve as enablers transferring key resources to job seekers.
Use of magic sandwich echo and fast field cycling NMR relaxometry on honey adulteration with corn syrup
Authors: Berk Berkay , Cavdaroglu Cagri , Grunin Leonid , Ardelean Ioan , Kruk Danuta , Mazi Bekir G , Oztop Mecit H 
Published: October 2021

AbstractBACKGROUNDAdulteration is defined as the intentional addition of a material that is not a part of the nature. In this study, a non‐conventional time domain nuclear magnetic resonance (TD‐NMR) pulse sequence: magic sandwich echo (MSE) was used to detect the adulteration of honey by glucose syrup (GS) and high fructose corn syrup (HFCS) accompanied with T1 and T2 relaxation times. Also, fast field cycling NMR (FFC‐NMR) relaxometry and multivariate analysis were performed to investigate the adulteration.RESULTSHigher maltose in GS and changing glucose to water ratio of HFCS gave high correlation with the crystal content values. In HFCS adulteration, two separate populations of protons having different T2 values were detected and T1 times were also used to determine GS adulteration. Addition of GS increased T1 while addition of HFCS increased T2, significantly.CONCLUSIONThe results showed that it is possible to differentiate the unadulterated and adulterated honey samples by using TD‐NMR relaxation times and crystal content values obtained by the MSE sequence. By FFC‐NMR relaxometry, not only GS addition but also the amount of GS was examined. The multivariate analysis technique of principal component analysis was able to distinguish the types of adulterants. © 2021 Society of Chemical Industry.