bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA Adduct Detection after Post‐Labeling Technique with PCR Amplification (DNA‐ADAPT–qPCR) Identifies the Pre‐ribosomal RNA Gene as a Direct Target of Platinum–Acridine Anticancer Agents
Authors: Yao Xiyuan , Bierbach Ulrich 
Published: August 2021

AbstractTo study the DNA damage caused by a potent platinum–acridine anticancer agent (PA) in cancer cells, an assay based on biorthogonal post‐labeling using a click chemistry‐enabled, azide‐modified derivative (APA) was developed. The method involves biotinylation, affinity capture, and bead‐based enrichment of APA‐modified genomic DNA. The key steps of the assay were validated and optimized in model duplexes, including full‐length plasmids, restriction fragments, and a DNA ladder. Native DNA treated with APA and subsequently subjected to post‐labeling with a biotin affinity tag was enzymatically digested and fragments were analyzed by in‐line LC–MS and MS/MS. The monofunctional–intercalative adducts formed by APA in 5′‐pyrimidine/guanine sequences in double‐stranded DNA were quantitatively biotinylated by strain‐promoted 1,3‐dipolar cycloaddition chemistry. When applied to DNA extracted from A549 lung cancer cells, the assay in combination with qPCR amplification demonstrates that platinum–acridines form adducts in the gene sequences encoding pre‐ribosomal RNA, a potential pharmacological target of these agents.
Photocatalyzed Reverse Polarity Oxidative Povarov Reaction of Glycine Derivatives with Maleimides
Authors: Zhang Yongxin , Jiang Wei , Bao Xiazhen , Qiu Yifeng , Yuan Yong , Yang Caixia , Huo Congde 
Published: August 2021

Main observation and conclusionAn oxidative tandem (4+2)‐cyclization/aromatization of N‐aryl glycine derivatives with electron‐deficient alkenes was first achieved using Ru(bpy)3Cl2 as a photocatalyst and TBHP as an oxidant in combination with visible‐light irradiation by blue LEDs. One‐electron oxidation and the following α‐deprotonation of glycine derivatives afford α‐amino alkyl radicals, which were then trapped by electrophilic maleimides. As an atom‐economic and efficient method, a variety of pyrrolo[3,4‐c]quinoline‐1,3‐diones have been obtained in good yields under mild reaction conditions.
Aging Pacific cod (Gadus macrocephalus) from otoliths using Fourier‐transformed near‐infrared spectroscopy
Authors: Healy Jordan , Helser Thomas E. , Benson Irina M. , Tornabene Luke 
Published: August 2021

AbstractFor decades, age‐structured stock assessments have been a key component to managing fishery resources worldwide. Fisheries management systems have been under increasing demand to generate a greater volume and quality of age estimates. Traditional aging techniques, which require physical preparation followed by microscopic examination of fish otoliths, are labor‐intensive, expensive, and inherently subjective among individual analysts, making repeatability and precision a challenge. Here we investigated an innovative approach to aging fish from their otoliths using Fourier‐transformed near‐infrared spectroscopy and partial least squares regression models. Models were fit to and validated on spectra and used to microscopically estimate ages of Pacific cod from three years of fishery‐independent otolith data out of the Bering sea. Calibrated and validated models for each year, as well as on an ensemble of the three years, yielded high precision for the multiyear model (R2 = 0.869, RMSE = 0.614, PA = 63%, CV = 7.412), and independent year models (R2 = 0.844–0.891, RMSE = 0.555–0.615, PA = 65%, CV = 6.313–6.775). These metrics of model performance were highly comparable to precision from the traditional microscopic aging approach (R2 = 0.763–0.869, RMSE = 0.639–0.737, PA = 63%–70%, CV = 5.671–6.698). In all cases, a two‐sided Kolmogorov–Smirnov test showed no significant difference between reference and model estimated age distributions. Our results illustrate how Fourier‐transformed near‐infrared spectroscopy can be utilized on otoliths to predict age estimates with substantially greater efficiency, good precision, high repeatability, and no loss in data integrity compared to the traditional microscopic method for aging Pacific cod.
Left atrial conduit flow rate at baseline and during exercise: an index of impaired relaxation in HFpEF patients
Authors: Marino Paolo N. , Zanaboni Jacopo , Degiovanni Anna , Sartori Chiara , Patti Giuseppe , Fraser Alan G. 
Published: August 2021

AbstractAimsIn healthy subjects, adrenergic stimulation augments left ventricular (LV) long‐axis shortening and lengthening, and increases left atrial (LA) to LV intracavitary pressure gradients in early diastole. Lower increments are observed in patients with heart failure with preserved ejection fraction (HFpEF). We hypothesized that exercise in HFpEF would further impair passive LV filling in early‐mid diastole, during conduit flow from pulmonary veins.Methods and resultsTwenty HFpEF patients (67.8 ± 9.8 years; 11 women), diagnosed using 2007 ESC recommendations, underwent ramped semi‐supine bicycle exercise to submaximal target heart rate (∼100 bpm) or symptoms. Seventeen asymptomatic subjects (64.3 ± 8.9 years; 7 women) were controls. Simultaneous LA and LV volumes were measured from pyramidal 3D‐echocardiographic full‐volume datasets acquired from an apical window at baseline and during stress, together with brachial arterial pressure. LA conduit flow was computed from the increase in LV volume from its minimum at end‐systole to the last frame before atrial contraction (onset of the P wave), minus the reduction in LA volume during the same time interval; the difference was integrated and expressed as average flow rate, according to a published formula. The slope of single‐beat preload recruitable stroke work (PRSW) quantified LV inotropic state. 3D LV torsion (rotation of the apex minus rotation of the base divided by LV length) was also measurable, both at rest and during stress, in 10 HFpEF patients and 4 controls. There were divergent responses in conduit flow rate, which increased by 40% during exercise in controls (+17.8 ± 37.3 mL/s) but decreased by 18% in patients with HFpEF (−9.6 ± 42.3 mL/s) (P = 0.046), along with congruent changes (+1.77 ± 1.13°/cm vs. −1.94 ± 2.73°/cm) in apical torsion (P = 0.032). Increments of conduit flow rate and apical torsion during stress correlated with changes in PRSW slope (P = 0.003 and P = 0.006, respectively).ConclusionsIn HFpEF, conduit flow rate decreases when diastolic dysfunction develops during exercise, in parallel with changes in LV inotropic state and torsion, contributing to impaired stroke volume reserve. Conduit flow is measurable using 3D‐echocardiographic full‐volume atrio‐ventricular datasets, and as a marker of LV relaxation can contribute to the diagnosis of HFpEF.
Applications of Purine Ring Opening in the Synthesis of Imidazole, Pyrimidine, and New Purine Derivatives
Authors: Leškovskis Kristaps , Zaķis Jānis Miķelis , Novosjolova Irina , Turks Māris 
Published: August 2021

AbstractPurines, which are regarded as relatively stable heterocyclic systems, can be opened at both pyrimidine and imidazole rings. Purine ring opening also serves as a tool for the preparation of ring‐modified purines through rearrangement/recyclization mechanisms. The obtained imidazole, pyrimidine, and purine derivatives are privileged molecular scaffolds in medicinal and agricultural chemistry. Purine ring‐opening approach is a useful alternative for their synthesis, which competes well with de novo approach or modification of a conserved heterocyclic core. The substitution patterns and groups that activate purines towards ring opening are reviewed. Moreover, mechanistic studies using labelled substrates, which are leading to rearranged purine derivatives are covered. Furthermore, an insight into imidazole ring opening upon exposure of purine system to DNA damaging agents is provided.
Mechanisms of change in acceptance and commitment therapy for primary headaches
Authors: Vasiliou Vasilis S. , Karademas Evangelos C. , Christou Yiolanda , Papacostas Savvas , Karekla Maria 
Published: August 2021

AbstractBackgroundDespite the demonstrated effectiveness of behavioural headache interventions, it is not yet known which intervention processes account for treatment responses. Acceptance and commitment therapy (ACT), an emerging behavioural intervention for headaches, proposes psychological flexibility (PF) processes as the mechanisms via which intervention change occurs. This is the first study examining these processes of change variables on headache‐related disability and quality of life (treatment outcome).MethodsData originated from a Randomized Clinical Trial evaluating the efficacy of ACT for primary headaches. Ninety‐four individuals with primary headaches (M = 43 y; 84% females; M headache frequency/month = 9.30) were randomized to either an ACT‐based or a Wait‐list control group (N = 47 in each). Participants completed questionnaires related to their headache experiences and PF processes at pre‐ (T1), post‐treatment (T2), and 3‐month follow‐up (T3).ResultsFollowing a bootstrapped cross product of coefficients approach, results demonstrated mediating effects of headache acceptance, cognitive defusion, avoidance of headache, and mindfulness in the ACT group compared to control on parameters of headache‐related disability and quality of life at post and 3‐month follow‐ups.ConclusionsThese findings demonstrate that changes in certain PF processes lower disability and improve quality of life in headache sufferers, supporting that ACT works via its proposed mechanisms of change. Interventions for headache management may be optimized if they target increases in headache acceptance, defusion from thoughts, and mindfulness.SignificancePsychological flexibility (PF) guides the ACT approach, an emerging behavioral headache intervention that focuses on optimizing head pain adjustment via flexible responses to pain. It targets at increasing daily functioning rather than preventing or controlling headache episodes. Pain acceptance, cognitive defusion, and mindfulness act as processes of functional change in ACT, lowering disability and increasing daily functioning and quality of life. These components can upgrade the established effectiveness of behavioral headache interventions with personalized, modularized therapeutic targets that can help headache sufferers re‐establish optimal daily functioning even in fluctuating and persistent headache episodes.Trial registrationclinical trials.gov registry (NCT02734992).
Optimization of engine operating variables on performance and emissions characteristics of biogas fuelled CI engine by the design of experiments: Taguchi approach
Authors: Mahla Sunil Kumar , Goyal Tarun , Goyal Deepam , Sharma Himanshu , Dhir Amit , Goga Geetesh 
Published: August 2021

AbstractBiogas obtained from renewable resources is a viable solution for solving energy scarcity and environmental degradation. A single‐cylinder 4‐stroke natural aspirated variable compression ratio research engine was fuelled with biogas as primary and diesel as a pilot injection in this work. Experiments were designed based on Taguchi L9 OA (orthogonal array) choosing biogas flow rate, compression ratio, and engine load as input factors, while brake thermal efficiency (BTE), BSEC, CO, HC, NOx, and smoke were targeted responses. The effects level of factors on responses was analysed by using MINITAB software. The higher value of raw data and S/N ratios for BTE was observed with low biogas flow rate, higher compression ratio, and full engine load. On the other hand, lower raw data and high S/N ratio analysis for emissions characteristics (CO, HC, NOx, and smoke) were achieved in the order of rank, that is, engine load > biogas flow rate > compression ratio. With the analysis of results, optimum levels of various factors were evaluated. These results showed that the Taguchi method design was an effective tool for optimizing the elements in terms of combustion performance and emissions characteristics.
Statistical QoS guarantees of a device‐to‐device link assisted by a full‐duplex relay
Authors: Waqas Haider Shah Syed , Li Rongpeng , Mahboob Ur Rahman Muhammad , Noor Mian Adnan , Aman Waqas , Crowcroft Jon 
Published: August 2021

AbstractDevice‐to‐device (D2D) communication is a promising technique to enhance the spectral efficiency for 5G and beyond cellular networks. Traditionally, D2D communication was considered solely as communication directly between two closely‐located devices, without any support from the available network infrastructure; however, this understanding limits the advantages of D2D communication. Relay‐assisted D2D communication was later proposed to allow devices to exchange data and extend coverage via relay strategy for transmission distance extension and capacity improvements. This work aims to determine the statistical quality‐of‐service (QoS) guarantees of a D2D link assisted by a full‐duplex relay by employing a commonly used analytical tool, the effective capacity (EC). We provide a closed‐form expression for the EC of relay‐assisted D2D communication, in which both the transmitter and the relay devices operate under individual QoS constraints. We also provide an analysis of the impact of mode selection on the EC of relay‐assisted D2D. Additionally, for the mode selection, we propose a novel multiple features‐based mechanism by utilizing all the features of a wireless link. We further provide a closed‐form solution for the non‐convex calibration problem of the optimal weights for these underlying features. Finally, simulation results demonstrate how the quality of self‐interference cancellation techniques impacts the EC of the relay‐assisted D2D. The results also show that the performance of our proposed mode selection mechanism with optimal weights outperforms the traditional mode selection mechanism.
Modeling crystallization kinetics for selective laser sintering of polyamide 12
Authors: Soldner Dominic , Steinmann Paul , Mergheim Julia 
Published: August 2021

AbstractSelective laser sintering (SLS) of polymers represents a widely used additive manufacturing process, where the part quality depends highly on the present thermal conditions. One distinct feature of SLS is the existence of separate temperature regions for melting and crystallization (solidification) and that the process optimally operates within said regions. Typically a crystallization model, such as the Nakamura model, is used to predict the degree of crystallization as a function of temperature and time. One limitation of this model is the inability to compute negative rates of the crystallization degree during remelting. As we will show in this work, such an extension is necessary, considering the varying temperature fields appearing in SLS. To this end, an extension is proposed and analyzed in detail. Furthermore, a dependency of the temperature and crystallization fields on the size of geometrical features is presented.
Hydroamination of Dihapto‐Coordinated Benzene and Diene Complexes of Tungsten: Fundamental Studies and the Synthesis of γ‐Lycorane
Authors: Wilson Katy B. , Nedzbala Hannah S. , Simpson Spenser R. , Ericson Megan N. , Westendorff Karl S. , Chordia Mahendra D. , Dickie Diane A. , Harman W. Dean 
Published: August 2021

AbstractReactions are described for complexes of the form WTp(NO)(PMe3)(η2‐arene) and various amines, where the arene is benzene or benzene with an electron‐withdrawing substituent (CF3, SO2Ph, SO2Me). The arene complex is first protonated to form an η2‐arenium species, which then selectively adds the amine. The resulting η2‐5‐amino‐1,3‐cyclohexadiene complexes can then be subjected to the same sequence with a second nucleophile to form 3‐aminocyclohexene complexes, where up to three stereocenters originate from the arene carbons. Alternatively, 1,3‐cyclohexadiene complexes containing an ester group at the 5 position (also prepared from an arene) can be treated with acid followed by an amine to form trisubstituted 3‐aminocyclohexenes. When the amine is primary, ring closure can occur to form a cis‐fused bicyclic γ‐lactam. Highly functionalized cyclohexenes can be liberated from the tungsten through oxidative decomplexation. The potential utility of this methodology is demonstrated in the synthesis of the alkaloid γ‐lycorane. An enantioenriched synthesis of a lactam precursor to γ‐lycorane is also described. This compound is prepared from an enantioenriched version of the tungsten benzene complex. Regio‐ and stereochemical assignments for the reported compounds are supported by detailed 2D‐NMR analysis and 13 molecular structure determinations (SC‐XRD).
Application of multimedia models for understanding the environmental behavior of volatile methylsiloxanes: Fate, transport, and bioaccumulation
Authors: Whelan Michael J. , Kim Jaeshin 
Published: August 2021

Abstract
Multimedia fate and transport models (MFTMs) describe how chemicals behave in the environment based on their inherent properties and the characteristics of receiving systems. We critically review the use of MFTMs for understanding the behavior of volatile methylsiloxanes (VMS). MFTMs have been used to predict the fate of VMS in wastewater treatment, rivers, lakes, marine systems, and the atmosphere, and to assess bioaccumulation and trophic transfers. More widely, they have been used to assess the overall persistence, long-range transport potential (LRTP), and the propensity for atmosphere–surface exchange. The application of MFTMs for VMS requires particularly careful selection of model inputs because the properties of VMS differ from those of most organic compounds. For example, although n-octanol/water partition coefficient (KOW) values are high, air:water partition coefficient (KAW) values are also high and n-octanol/air partition coefficient (KOA) values are relatively low. In addition, organic carbon/water partition coefficient (KOC) values are substantially lower than expectations based on KOW. This means that most empirical relationships between KOC and KOW are not appropriate. Good agreement between modeled and measured concentrations in air, sediment, and biota indicates that our understanding of environmental fate is reasonable. VMS compounds are “fliers” that principally partition to the atmosphere, implying high LRTP, although they have low redeposition potential. They are degraded in air (half-lives 3–10 days) and, thus, have low overall persistence. In water, exposure can be limited by hydrolysis, volatilization, and partitioning to sediments (where degradation half-lives are likely to be high). In food webs, they are influenced by metabolism in biota, which tends to drive trophic dilution (i.e., trophic magnification factors are often but not always &lt;1). Key remaining uncertainties include the following: (i) the strength and direction of the temperature dependence for KOC; (ii) the fate of atmospheric reaction products; and (iii) the magnitude of emissions to wastewater. Integr Environ Assess Manag 2022;18:599–621. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
KEY POINTS
We critically review the use of MFTMs as a framework for understanding the environmental behavior of volatile methylsiloxanes (VMS). Careful selection of model inputs is needed because the properties of VMS differ from those of most organic compounds which means that some empirical estimation methods are not appropriate. Key remaining uncertainties include: (i) the strength and direction of the temperature-dependence of partition coefficients; (ii) the fate of atmospheric reaction products; (iii) the magnitude of emissions to wastewater and (iv) the extent to which trophic transfer is influenced by metabolism.
The influence of the activation function in a capsule network for brain tumor type classification
Authors: Adu Kwabena , Yu Yongbin , Cai Jingye , Asare Isaac , Quahin Jennifer 
Published: August 2021

AbstractCapsule network's hierarchical framework (CapsNets) consists of an initial standard convolution layer that uses an activation function at its core. The rectified linear unit (ReLU) activation function is widely used in CapsNet and brain tumor classification tasks among several existing activation functions. However, ReLU has some shortcomings where the zero derivatives of the function cause failure of neuron activation. Furthermore, the performance accuracy obtained by the ReLU with CapsNet on brain tumor classification is unsatisfactory. We proposed a new activation function called parametric scaled hyperbolic tangent (PSTanh), which enhances the conventional hyperbolic tangent by avoiding vanishing gradient, provides a small gradient with the introduction of and parameters, and enables faster optimization. Eight standard activation functions (i.e., tanh, Memrister‐Like Activation Function (ReLU), Leaky‐ReLU, PReLU, ELU, SELU, Swish, ReLU‐Memrister‐Like Activation Function (RMAF), and the proposed activation) are analyzed and compared in brain tumor classification tasks. Furthermore, extensive experiments are conducted using MNIST, fashion‐MNIST, CIFAR‐10, CIFAR‐100, and ImageNet datasets trained on CapsNets models and deep CNN models (i.e., AlexNet, SqueezeNet, ResNet50, and DenseNet121). The brain tumor's experimental results based on CapsNet and CNN model show that the proposed PSTanh activation achieves better performance than other functions.
Improving auditor performance evaluations: The impact on self‐esteem, professional skepticism, and audit quality
Authors: Blix Leslie H. , Chui Lawrence C. , Pike Byron J. , Robinson Shani N. 
Published: August 2021

AbstractIn public accounting, the performance evaluation process involves assessing and communicating feedback to employees. In the financial statement audit setting, in particular, supervisors provide feedback to subordinates frequently throughout a fiscal year. Prior research finds that performance evaluations are based largely on the subordinate's work outcomes, such as task completion and budgeted hours, and also are related to employee satisfaction/dissatisfaction and an increase/decrease in overall job performance. Utilizing psychology theories, we investigate whether a manager's feedback tone (supportive/non‐supportive) and evaluation focus (tasks/goals) influence auditors’ self‐esteem as well as their corresponding professional skepticism, including their search for evidence. Based on an experiment with 118 experienced auditors, we find that supportive and goal‐focused performance evaluations, independently, lead to higher self‐esteem. This elevated self‐esteem translates into desirable auditor attributes, such as greater professional skepticism and an increase in search for evidence and audit quality. Our results are valuable to practice, as firms attempt to train and retain their employees through the performance evaluation process.