bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prudent Practices in ex situ Durability Analysis Using Cyclic Voltammetry for Platinum‐based Electrocatalysts
Authors: Agrawal Khantesh , Naik Adarsh Ajith , Chaudhary Saroj , Parvatalu Damaraju , Santhanam Venugopal 
Published: August 2021

AbstractPlatinum (Pt)‐based electrocatalysts are at the vanguard of research initiatives to meet activity and durability targets for promoting large‐scale adoption of fuel cell vehicles. Ex situ characterization of electrocatalyst activity and durability using cyclic voltammetry (CV) has a steep learning curve. Thus, many researchers who do not receive formal training in electrochemistry are left unsure how to proceed. Herein, we identify and compile prudent practices for reliable assessment of ECSA values with examples from our research on nanoscale catalytic films formed by the self‐terminating electrodeposition of Pt. Starting with a conceptual framework to understand typical features in the CV of reversible redox couples, we present prudent practices in acquiring CV data aimed at nonelectrochemists. We then highlight specific features related to ECSA computation from Pt CV. Finally, we suggest safeguards that help avoid missteps and achieve repeatable results while conducting ex situ durability tests that extend over days.
Pressure‐Induced Phase Transition, Jahn‐Teller Suppression, Optical and Electronic Property Evolutions in Ruddlesden‐Popper Perovskites Rb2CuCl4‐xBrx
Authors: Liu Ke , Li Chen , Wen Ting , Jiang Dequan , Jiang Zimin , Ma Yingying , Wang Yonggang 
Published: August 2021

AbstractTransition‐metal containing halides with Ruddlesden‐Popper (RP) perovskite structures have received extensive attention owing to their emerging and anisotropic photoelectric functionalities. Among them, A2CuX4 (A=alkali metal or organic cations, X=Cl, Br, I) series are particular, because of the Jahn‐Teller distortion of Cu2+ sensitive to external stimuli such as temperature and pressure. In this article, we report the structure evolution and physical property responses of RP perovskites Rb2CuCl4‐xBrx (x=1, 2) to external pressure. Dramatic structural phase transitions from orthorhombic to monoclinic occur around 3.0 GPa in both materials regardless of their distinct compositions. Structure analyses reveal the suppression and final vanishing of the Jahn‐Teller distortion of Cu2+ cations under compression and crossing the phase transition, respectively. Rb2CuCl4‐xBrx perovskites exhibit abrupt bandgap narrowing (from reddish‐brown to black) along with the structural phase transition, and an overall bandgap narrowing of 75% up to ∼27 GPa but still keeping semiconductive. During the compression processes, the resistances of Rb2CuCl4‐xBrx have been greatly reduced by 5‐orders of magnitude. Moreover, all of the pressure‐induced phenomena in Rb2CuCl4‐xBrx perovskites are reversible upon decompression and no obvious difference is observed for the pressure responses between [CuCl4Br2] and [CuCl4(Cl,Br)2] coordination environments. The impact of pressure on the structural and physical properties in two‐dimensional Rb2CuCl4‐xBrx provides in‐depth understanding on the structure design of functional halide perovskites at ambient conditions.
Photolabile Protecting Group‐Mediated Synthesis of 2‐Deoxy‐Glycosides
Authors: Li Xiaoqian , Ma Zhi , Liu Rongkun , Hurevich Mattan , Yang You 
Published: August 2021

Main observation and conclusionA green and efficient photolabile protecting group (PPG)‐mediated glycosidation approach for the synthesis of 2‐deoxy‐glycosides is reported. By employing ortho‐nitrobenzyl carbonate (oNBC) as PPG, N,N‐dimethylformamide (DMF)‐modulated SPhosAuNTf2‐promoted glycosidation with per‐oNBC‐protected 2‐deoxy‐glycosyl ynenoates affords the 2‐deoxy‐glycosides with moderate to excellent α‐selectivities presumably depending on the reactivities of the acceptor alcohols. Based on the PPG‐mediated glycosidation approach, oligosaccharides with three to six oNBC groups are effectively achieved. The multiple oNBC groups in the 2‐deoxy‐glycosides are completely cleaved by irradiation at 365 nm, resulting in the desired 2‐deoxy‐glycosides in an efficient manner without affecting the common alkyne, alkene, azide functional groups and the traditional protecting groups on the aglycones.
Electronic Structures and Properties of Actinide‐Bimetal Compounds An2O2 (An=Th to Cf) and U2E2 (E=N, F, S)
Authors: Zhang Peng , Zou Wen‐Li , Zhang Ping , Hu Shu‐Xian 
Published: August 2021

AbstractIn this study, we investigated the geometry structure and the chemical bonding of actinide clusters An2O2 by quantum chemistry calculations. Through the geometry searching for An2O2 clusters with the combination of considerable initial structures and spin states, it is found that a novel ground‐state structure of quasi‐linear type for Pa2O2 compares with a rhombic structure for the rest of An2O2 clusters. Due to the more extended 5 f orbitals, the Pa−Pa bond is verified to be a triple bond by the electronic configuration and the bond order analysis, which brings the quasi‐linear structure of Pa2O2 and distinguishes it from the rhombic ones. For both kinds of ground‐state structures, the participation of 5 f orbitals in the An−O bonds stabilizes the structures further. Owing to spin‐orbit coupling, the ground‐state structure of U2O2 changes from the linear one at the SR level to the rhombic one with SO into consideration. Further investigations on clusters U2E2 with different ligands reveal that the quasi‐linear U2F2 has an equivalent quadruple bond. The decline of the bonding electrons of the U−U bond, the foremost causes for the change of the structures and illustrates the decrease of the U−U bond strength. Our investigations on An2O2 and U2E2 compounds provide some insights into the role of 5 f orbital in the chemical bonding of actinide compounds and f‐f bonding in multiple bonding.
Performance and emissions of neat crude palm oil and its emulsions as diesel engine fuel
Authors: Ezzat Chan Arif Fahim , Yahya Wira Jazair , Abd Kadir Hasannuddin , Abdullah Nik Rosli , Ithnin Ahmad Muhsin , Hawari Yahaya , Sugeng Dhani Avianto 
Published: August 2021

AbstractThe depletion of petroleum diesel has prompted the use of biofuels and other alternative sources of energy. The direct use of neat crude palm oil (CPO) has mostly resulted in the increase of oxides of nitrogen (NOx). Emulsification has demonstrated the capability of reducing NOx emissions. An experiment is conducted to investigate the effect of increasing water content in CPO. Water‐in‐CPO emulsions with varying water contents by volume (5%, 10%, and 15%) with 1% SPAN 80 surfactant are labeled as W5CPO, W10CPO, and W15CPO. The fuels were tested on a single‐cylinder diesel generator at 2900 and 3200 rpm with varying electrical load. For all load conditions at 3200 rpm, the smoke opacimeter reading is highest at 35% with W15CPO and the lowest smoke reading is 15% with W5CPO as fuel. The NOx of CPO was higher than ordinary diesel up to 29% at lower load. The NOx emissions of the CPO was reduced when the amount of water was increased. The maximum reduction in NOx of W15CPO was 66% whereas the minimum NOx reduction was 31%. At 3200 rpm and 4 kW, the CO emission of W5CPO was 21% lower in relation to CPO. The W5CPO showed a different trend in the exhaust emissions compared to Water‐in‐CPO emulsions with higher water content. Overall, emulsification has the potential to reduce NOx emissions in relation to neat CPO.
Preparation and Characterization of Pentafluoro‐λ6‐sulfanyldifluoromethane and Pentafluoro‐λ6‐sulfanyl‐1,1,2,2‐tetrafluoroethane
Authors: Belina Steven P. , Qing Si‐Yan , Dudziński Piotr , Matsnev Andrej V. , Mück‐Lichtenfeld Christian , Haufe Günter , Thrasher Joseph S. 
Published: August 2021

AbstractThe pentafluorosulfanyl‐λ6‐perfluoroalkyl halides SF5CF2I, SF5CF2CF2Br, and SF5CF2CF2I were prepared for use in the syntheses of other SF5‐containing compounds. For example, new, convenient syntheses were developed for the hydro compounds SF5CF2H and SF5CF2CF2H from the reduction of these iodides or bromides with either triethylborane or tributyltin hydride. Herein, more thorough spectroscopic analyses of the hydro compounds are presented, including multinuclear NMR and vibrational spectroscopy, mass spectrometry, and computational chemistry. Unfortunately, under the conditions tried, little to no evidence was obtained for potential SF5(CF2)n‐ (where n=1 or 2) transfer reagents such as SF5(CF2)nSi(CH3)3 or Cu(CF2)nSF5.
Risk‐stratified strategies in population screening for colorectal cancer
Authors: Lansdorp‐Vogelaar Iris , Meester Reinier , de Jonge Lucie , Buron Andrea , Haug Ulrike , Senore Carlo 
Published: August 2021

AbstractColorectal cancer (CRC) screening has been demonstrated to reduce CRC incidence and mortality. However, besides such benefits, CRC screening is also associated with potential harmful effects. In an ideal world, screening would only be directed to the small proportion of the population that might potentially benefit. Risk‐based screening can be seen as a first step towards this ideal world, by redistributing screening resources from low‐risk to high‐risk individuals. In theory, this should result in scarce resources being used in individuals who benefit most, while intensity of screening is reduced in individuals who benefit less, hence improving the benefit‐harm ratio among all invitees. Available strategies that have been proposed for risk‐based CRC screening include using information on age, sex, prior screening history, lifestyle and/or genetic information. Implementation of risk‐based screening requires careful consideration of reliable risk prediction models, participation with screening and informed decision‐making. While it is important to recognise the limitations of current approaches, available evidence suggests that it might be feasible to start planning the introduction of tailored strategies within screening programmes. Implementing risk‐based screening based on age, sex and prior screening history alone would already represent a substantial improvement over current uniform screening approaches. We propose that it is time that screening programmes start there and continue striving towards more comprehensive approaches embedding primary prevention as an effective approach to lower risk for everyone.
Role of stress granules in modulating senescence and promoting cancer progression: Special emphasis on glioma
Authors: Chatterjee Debmita , Chakrabarti Oishee 
Published: August 2021

AbstractStress granules (SGs) contain mRNAs and proteins stalled in translation during stress; these are increasingly being implicated in diseases, including neurological disorders and cancer. The dysregulated assembly, persistence, disassembly and clearance of SGs contribute to the process of senescence. Senescence has long been a mysterious player in cellular physiology and associated diseases. The systemic process of aging has been pivotal in the development of various neurological disorders like age‐related neuropathy, Alzheimer's disease and Parkinson's disease. Glioma is a cancer of neurological origin with a very poor prognosis and high rate of recurrence, SGs have only recently been implicated in its pathogenesis. Senescence has long been established to play an antitumorigenic role, however, relatively less studied is its protumorigenic importance. Here, we have evaluated the existing literature to assess the crosstalk of the two biological phenomena of senescence and SG formation in the context of tumorigenesis. In this review, we have attempted to analyze the contribution of senescence in regulating diverse cellular processes, like, senescence associated secretory phenotype (SASP), microtubular reorganization, telomeric alteration, autophagic clearance and how intricately these phenomena are tied with the formation of SGs. Finally, we propose that interplay between senescence, its contributing factors and the genesis of SGs can drive tumorigenicity of gliomas, which can potentially be utilized for therapeutic intervention.
Elements of Th1/Th2 response and disease severity in COVID‐19 patients: A short report
Authors: Akinosoglou Karolina , Delastic Anne‐Lise , Dimakopoulou Vasilina , Marangos Markos , Gogos Charalambos 
Published: August 2021

AbstractThe presence of a complex immune dysregulation syndrome has been established in COVID‐19 patients. We aimed to assess Th1/Th2 response in COVID‐19 patients and its association with disease severity by performing a prospective cohort study in a tertiary hospital COVID‐19 referral center. We report no difference between Th1/Th2 responses between patients with severe and mild disease, except for levels of interleukin‐6 (IL‐6) and IL‐10. Future larger studies should examine lung‐specific versus systemic inflammatory responses, as well as, diverse immunotypes driving poor clinical outcomes.
An appraisal of seasonal precipitation dynamics over the North‐West Himalayan region under future warming scenarios
Authors: Banerjee Debangshu , Singh Charu 
Published: August 2021

ABSTRACTIn the context of widely reported climate change over the mountainous region, the present work addresses the notable changes in the seasonal precipitation dynamics over the NWH region under two different future warming scenarios [socioeconomic pathway 245 (SSP245) and socio economic pathway 585 (SSP585)]. Using three coupled climate models which participated in the Climate Model Inter‐comparison Project Phase 6 (CMIP6), we focus on the alterations of the spatio‐temporal pattern of solid and liquid precipitation in respective seasons under future warming (2066–2100) scenarios with respect to the historical time period (1981–2014). Intercomparative validation of the CMIP6 data sets has been carried out against the GPCP and ERA‐5 reanalysis datasets where the multimodel mean (MMM) product has performed well (r value = 0.63) compared with the individual model outputs in the historical scenario for last 35 years (1981–2014). Therefore, MMM has been used for analysis. Statistically robust K–S test suggests a remarkable variation in the cumulative distribution of the precipitation across the NWH region at 95% confidence level in both of the future warming scenarios as compared with the historical time period. Furthermore, significant increase in the JJAS rainfall (~25–30%) and decrease in the DJF snowfall (~20–25%) has been observed for ssp585 scenario whereas no significant results are noted under ssp245 scenario. Remarkable variations in the surface temperature distribution, large scale wind circulation pattern and mesoscale hydrometeorological balance under the warmest scenario (SSP585) elucidate the reason behind the noteworthy changes in the precipitation dynamics reflected from the normalized precipitation index (NPI) and changes in annual cycle and therefore illustrates the possibility of more extreme precipitation years in future. The overall investigation reflects the possible effect of climate change over the NWH region pertaining to the dynamics of the South West Monsoon and Western Disturbances.
Imidazole‐modified C6‐chitosan derivatives used to extract β‐sitosterol from edible oil samples with a microwave‐assisted solid phase extraction method
Authors: Dai Yunliang , Row Kyung Ho 
Published: August 2021

Abstractβ‐Sitosterol is a major bioactive constituent in plants with potent anticancer effects against many human cancer cells, but its bioavailability and therapeutic efficacy are limited by its poor solubility in water. In this study, C6‐imidazole chitosan, C6‐1‐methylimidazole chitosan, C6‐1‐ethylimidazole chitosan, C6‐1‐vinylimidazole chitosan, C6‐1‐allylimidazole chitosan, and C6‐1‐butylimidazole chitosan were prepared to extract β‐sitosterol from edible oil samples via ultrasonic‐assisted solid liquid extraction. The structures and properties of the newly synthesized products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and elemental analysis. The extraction abilities of the derivatives were tested in the experiment with high‐performance liquid chromatography (limit of detection 0.21 μg/g and limit of quantification 0.67 μg/g), and the % relative standard deviation (<3.25%) and recovery values of the prepared chitosan derivatives toward β‐sitosterol (average: 100.20%) were acceptable. The spiked interday and intraday recoveries of β‐sitosterol were 102.60 ± 2.78 and 103.90 ± 3.04%, respectively. The actual amounts of β‐sitosterol extracted from three real samples using C6‐imidazole chitosan according to the solid phase extraction method were 3302.40, 901.70, and 2045.60 mg/kg for corn oil, olive oil, and pea oil, respectively.
Accurate and robust sparse‐view angle CT image reconstruction using deep learning and prior image constrained compressed sensing (DL‐PICCS)
Authors: Zhang Chengzhu , Li Yinsheng , Chen Guang‐Hong 
Published: August 2021

AbstractBackground: Sparse‐view CT image reconstruction problems encountered in dynamic CT acquisitions are technically challenging. Recently, many deep learning strategies have been proposed to reconstruct CT images from sparse‐view angle acquisitions showing promising results. However, two fundamental problems with these deep learning reconstruction methods remain to be addressed: (1) limited reconstruction accuracy for individual patients and (2) limited generalizability for patient statistical cohorts.Purpose: The purpose of this work is to address the previously mentioned challenges in current deep learning methods.Methods: A method that combines a deep learning strategy with prior image constrained compressed sensing (PICCS) was developed to address these two problems. In this method, the sparse‐view CT data were reconstructed by the conventional filtered backprojection (FBP) method first, and then processed by the trained deep neural network to eliminate streaking artifacts. The outputs of the deep learning architecture were then used as the needed prior image in PICCS to reconstruct the image. If the noise level from the PICCS reconstruction is not satisfactory, another light duty deep neural network can then be used to reduce noise level. Both extensive numerical simulation data and human subject data have been used to quantitatively and qualitatively assess the performance of the proposed DL‐PICCS method in terms of reconstruction accuracy and generalizability.Results: Extensive evaluation studies have demonstrated that: (1) quantitative reconstruction accuracy of DL‐PICCS for individual patient is improved when it is compared with the deep learning methods and CS‐based methods; (2) the false‐positive lesion‐like structures and false negative missing anatomical structures in the deep learning approaches can be effectively eliminated in the DL‐PICCS reconstructed images; and (3) DL‐PICCS enables a deep learning scheme to relax its working conditions to enhance its generalizability.Conclusions: DL‐PICCS offers a promising opportunity to achieve personalized reconstruction with improved reconstruction accuracy and enhanced generalizability.
Weakly supervised pneumonia localization in chest X‐rays using generative adversarial networks
Authors: Keshavamurthy Krishna Nand , Eickhoff Carsten , Juluru Krishna 
Published: August 2021

AbstractPurpose: Automatic localization of pneumonia on chest X‐rays (CXRs) is highly desirable both as an interpretive aid to the radiologist and for timely diagnosis of the disease. However, pneumonia's amorphous appearance on CXRs and complexity of normal anatomy in the chest present key challenges that hinder accurate localization. Existing studies in this area are either not optimized to preserve spatial information of abnormality or depend on expensive expert‐annotated bounding boxes. We present a novel generative adversarial network (GAN)‐based machine learning approach for this problem, which is weakly supervised (does not require any location annotations), was trained to retain spatial information, and can produce pixel‐wise abnormality maps highlighting regions of abnormality (as opposed to bounding boxes around abnormality).Methods: Our method is based on the Wasserstein GAN framework and, to the best of our knowledge, the first application of GANs to this problem. Specifically, from an abnormal CXR as input, we generated the corresponding pseudo normal CXR image as output. The pseudo normal CXR is the “hypothetical” normal, if the same abnormal CXR were not to have any abnormalities. We surmise that the difference between the pseudo normal and the abnormal CXR highlights the pixels suspected to have pneumonia and hence is our output abnormality map. We trained our algorithm on an “unpaired” data set of abnormal and normal CXRs and did not require any location annotations such as bounding boxes/segmentations of abnormal regions. Furthermore, we incorporated additional prior knowledge/constraints into the model and showed that they help improve localization performance. We validated the model on a data set consisting of 14 184 CXRs from the Radiological Society of North America pneumonia detection challenge.Results: We evaluated our methods by comparing the generated abnormality maps with radiologist annotated bounding boxes using receiver operating characteristic (ROC) analysis, image similarity metrics such as normalized cross‐correlation/mutual information, and abnormality detection rate.We also present visual examples of the abnormality maps, covering various scenarios of abnormality occurrence. Results demonstrate the ability to highlight regions of abnormality with the best method achieving an ROC area under the curve (AUC) of 0.77 and a detection rate of 85%.The GAN tended to perform better as prior knowledge/constraints were incorporated into the model.Conclusions: We presented a novel GAN based approach for localizing pneumonia on CXRs that (1) does not require expensive hand annotated location ground truth; and (2) was trained to produce abnormality maps at the pixel level as opposed to bounding boxes. We demonstrated the efficacy of our methods via quantitative and qualitative results.
Effects of Frozen Storage on Fish Wet Weight, Percent Dry Weight, and Length Revisited
Authors: Baltasar Regan Q. , Burge Erin J. , Crane Derek P. 
Published: August 2021

Abstract
Frozen storage can affect the physical characteristics of biological samples, and the effects can vary based on the frozen storage method that is used. We compared four frozen storage treatments: (1) flash frozen in liquid nitrogen (LN2) and stored at −20°C, (2) flash frozen in LN2 and stored at −65°C, (3) frozen in a saline solution (0.9% NaCl) and stored at −20°C, and (4) glazed with deionized (DI) water and stored at −20°C, to investigate the effects of frozen storage on wet weight, percent dry weight, and length of Mummichogs Fundulus heteroclitus. Mummichog wet weights differed from Prestorage wet weights for all treatments. Postthaw wet weight increased from the Prestorage wet weight for Mummichogs that were frozen in a saline solution (3–5% for 4–12 g fish). Conversely, Postthaw wet weight decreased from Prestorage wet weight (1–4% for 4–12 g fish) for Mummichogs that were frozen with LN2 and stored at −20°C or −65°C and Mummichogs that were glazed with deionized water and stored at −20°C. Subsequently, percent dry weight was underestimated by 0.77% for the Mummichogs that were frozen in a saline solution and overestimated for those that were frozen with LN2 and stored at −20°C (0.94%) or −65°C (0.60%) and those that were glazed with deionized water and stored at −20°C (0.71%). Fish total length decreased 2–3% after the samples had been frozen, and they did not differ among the four treatments. When possible, fish that are stored frozen should be measured and weighed alive or immediately after being euthanized, and if this is not possible, we suggest glazing the fish with water and developing correction factors for water loss and shrinkage.