bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation, equipment performance evaluation and sensitivity analysis as a comprehensive parametric study of sulfur recovery unit
Authors: Hashemi Meysam , Pourfayaz Fathollah , Mehrpooya Mehdi 
Published: February 2020

AbstractThe sulfur recovery unit based on modified Claus process with split flow was simulated, so that the validation results showed satisfactory agreement with the refinery data. In this study, comprehensive investigation was carried out on various parameters of the unit. Concentration changes of compounds were investigated as the process stream passes along various equipment. Composite curves were generated, and the minimum approach temperature was calculated as one of the operational parameters of heat exchangers. Fluid condensation probability was investigated in catalytic reactors. The recovery of sulfur and the amount of sulfur production were calculated by process streams passing along catalytic reactors and condensers respectively. The most influential performance parameters including the fuel flow rate, combustion air flow rate, and bypasses fraction were considered as sensitivity analysis parameters, and their variation influences were investigated on the recovery of sulfur, the ratio of hydrogen sulfide to sulfur dioxide, the amount of produced steam, and the furnace outlet stream temperature. The optimal amounts for fuel flow rate and inlet air flow rate were calculated with the values of 0 and 202 mol/s, respectively, and according to the results, 15% of the mainstream flow rate gives the optimum amount of bypass fraction.
Population structure, genetic diversity, and colonization history of the eastern pondmussel, Sagittunio nasutus, in the Great Lakes drainage
Authors: Scott Mariah W. , Morris Todd J. , Zanatta David T. 
Published: February 2020

Abstract

The eastern pondmussel, Sagittunio nasutus (Bivalvia: Unionida), has declined in abundance and distribution in eastern North America over the last few decades. The declines are predominantly the result of infestation by invasive dreissenid mussels and changes in habitat. The species is now considered imperilled across large portions of its distribution, especially in the Laurentian Great Lakes region.
The genetic diversity and structure of the remnant populations in the Great Lakes region were assessed using 10 newly developed microsatellite DNA loci for S. nasutus. Understanding the remaining populations can inform future management projects and determine whether the remnant populations have experienced a genetic bottleneck or a founder effect. We hope that this will inform the conservation of other species in regions founded by, and isolated from, a more genetically diverse source population or with disjointed geographical distributions.
Focusing on the Great Lakes region, samples (n = 428) from 62 collection sites in 28 water bodies were collected. Across the locations sampled for S. nasutus 11 genetic populations were identified, with significant genetic differentiation among them. The genetic structure of the species was assessed, with genetic similarities among populations compared and with geographical routes of colonization and gene flow evaluated.
Initial colonization from the Atlantic coast into Lake Erie and Lake Ontario is evident, followed by colonization events into nearby inland rivers and lakes. Analyses found evidence of inbreeding in all but one population and evidence of past genetic bottlenecks or strong founder effects in all but four populations. This study deepens our understanding of the genetic past and present of this imperilled species, providing conservation suggestions for the future management of the species.
The Link between Autotomy and CNS Regeneration: Echinoderms as Non‐Model Species for Regenerative Biology
Authors: Byrne Maria 
Published: February 2020

AbstractAchieving regeneration of the central nervous system (CNS) is a major challenge for regenerative medicine. The inability of mammals to regrow a severed CNS contrasts with the amazing regenerative powers of their deuterostome kin, the echinoderms. Rapid CNS regeneration from a specialized autotomy plane in echinoderms presents a highly tractable and suitable non‐model system for regenerative biology and evolution. Starfish arm autotomy triggers mass cell migration and local proliferation, facilitating rapid CNS regeneration. Many regeneration events in nature are preceded by autotomy and there are striking parallels between autotomy and regeneration in starfish and lizards. Comparison of these systems holds promise to provide insight into regeneration deficiency in higher vertebrates and to uncover evolutionarily conserved deuterostome‐chordate regenerative processes. This will help identify mechanisms that may be present but inactive in higher vertebrates to address the problem of their poor regenerative capacities and the challenge to achieve CNS repair and regrowth.
Multiply imputing missing values arising by design in transplant survival data
Authors: Pankhurst Laura , Mitra Robin , Kimber Alan , Collett Dave 
Published: February 2020

AbstractIn this article, we address a missing data problem that occurs in transplant survival studies. Recipients of organ transplants are followed up from transplantation and their survival times recorded, together with various explanatory variables. Due to differences in data collection procedures in different centers or over time, a particular explanatory variable (or set of variables) may only be recorded for certain recipients, which results in this variable being missing for a substantial number of records in the data. The variable may also turn out to be an important predictor of survival and so it is important to handle this missing‐by‐design problem appropriately. Consensus in the literature is to handle this problem with complete case analysis, as the missing data are assumed to arise under an appropriate missing at random mechanism that gives consistent estimates here. Specifically, the missing values can reasonably be assumed not to be related to the survival time. In this article, we investigate the potential for multiple imputation to handle this problem in a relevant study on survival after kidney transplantation, and show that it comprehensively outperforms complete case analysis on a range of measures. This is a particularly important finding in the medical context as imputing large amounts of missing data is often viewed with scepticism.
Anti‐invasive effect and pharmacological mechanism of genistein against colorectal cancer
Authors: Chen Xiaoyu , Wu Youjun , Gu Junzhao , Liang Ping , Shen Meizhen , Xi Jiaxi , Qin Jian 
Published: February 2020

AbstractColorectal cancer (CRC) refers to a deadly carcinoma following potent invasiveness and metastasis in advanced stage. Unfortunately, existing anti‐CRC medicine is insufficient for chemotherapy in addition to adverse effects. Consequently, the candidate natural ingredient for treating CRC needs to be further developed. Our previous experiments report that genistein exerts beneficial effects to inhibit CRC cells via an antiproliferative mechanism. Based on the metastatic characteristics of staging CRC, anti‐invasive and antimetastatic pharmacological activities using genistein remain uninvestigated. The scientific purpose of this study was to disclose the antimetastatic mechanism by using human and cell culture/nude mice samples, followed by biochemical tests and immunoassays. In human study, these CRC cases resulted in increased transforming growth factor beta‐1 (TGF‐β1) levels, long noncoding RNA (lncRNA) TTTY18 expressions, followed with up‐regulated Ki‐67, serum and glucocorticoid regulated kinase 1 (SGK1), AktSer473 expressions. In a study in vitro, genistein‐dosed CRC cells showed suppressed cell viability, promoted cell apoptosis, reduced Ki‐67 positive cells, reduced cellular migration, down‐regulated expressions of TTTY18, SGK1, AktSer473, p38 MAPKTyr323. In a further study in vivo, genistein‐dosed tumor‐bearing nude mice exhibited visibly reduced body mass, lowered tumorous TGF‐β1 and TTTY18 contents. In addition, intracellular numbers of SGK1, AktSer473, p38 MAPKTyr323 positive cells were reduced dose‐dependently. Collectively, these human and experimentative findings reveal that genistein pharmacologically exerts the potential antimetastatic CRC effects, possibly through a molecular mechanism of inhibiting TTTY18/Akt pathway in CRC cells.
Mammalian Pericardium‐Based Bioprosthetic Materials in Xenotransplantation and Tissue Engineering
Authors: Grebenik Ekaterina A. , Gafarova Elvira R. , Istranov Leonid P. , Istranova Elena V. , Ma Xiaowei , Xu Jing , Guo Weisheng , Atala Anthony , Timashev Peter S. 
Published: February 2020

AbstractBioprosthetic materials based on mammalian pericardium tissue are the gold standard in reconstructive surgery. Their application range covers repair of rectovaginal septum defects, abdominoplastics, urethroplasty, duraplastics, maxillofacial, ophthalmic, thoracic and cardiovascular reconstruction, etc. However, a number of factors contribute to the success of their integration into the host tissue including structural organization, mechanical strength, biocompatibility, immunogenicity, surface chemistry, and biodegradability. In order to improve the material's properties, various strategies are developed, such as decellularization, crosslinking, and detoxification. In this review, the existing issues and long‐term achievements in the development of bioprosthetic materials based on the mammalian pericardium tissue, aimed at a wide‐spectrum application in reconstructive surgery are analyzed. The basic technical approaches to preparation of biocompatible forms providing continuous functioning, optimization of biomechanical and functional properties, and clinical applicability are described.
Advanced X‐ray Absorption Spectroscopy Analysis to Determine Structure‐Activity Relationships for Cu‐Zeolites in the Direct Conversion of Methane to Methanol
Authors: Kvande Karoline , Pappas Dimitrios K. , Borfecchia Elisa , Lomachenko Kirill A. 
Published: February 2020

AbstractAn industrial process for direct conversion of methane to methanol (DMTM) would revolutionize methane as feedstock for the chemical industry and it would be a cherished contribution to climate change mitigation. At the present stage, it is a rather remote perspective, but the search for the materials that would make it possible and economically viable, is very active. Cu‐exchanged zeolites have been shown to cleave the C−H bond of methane at low temperatures (≤200 °C), and has been extensively studied for the stepwise DMTM conversion over the last decades. The determination of the speciation of CuxOy‐species in zeolites and the understanding of their role in the reaction mechanism has been heavily debated. Lately, advanced X‐ray absorption spectroscopy (XAS) analysis has been standing out as a powerful technique for investigating the behavior of Cu in zeolites. In this review we focus on thein situandoperandostudies of changes in the electronic and structural properties of Cu, during the different steps of the DMTM conversion uncovered by XAS, which have led to new and insightful information about the complex behavior of Cu‐zeolites in the DMTM process.
Unsymmetrical Strategy Makes Significant Differences in α‐Diimine Nickel and Palladium Catalyzed Ethylene (Co)Polymerizations
Authors: Hu Xiaoqiang , Zhang Yuxing , Zhang Yixin , Jian Zhongbao 
Published: February 2020

AbstractLigand steric bulk is one of the most important parameters on determining activity, polymer molecular weight, and branching density in α‐diimine Ni(II) and Pd(II) catalyzed ethylene polymerization. In this contribution, we delineated an unsymmetrical strategy to shed light on the effect of steric bulk in α‐diimine species via the unsymmetrically pentiptycenyl/dibenzhydryl α‐diimine Ni(II) and Pd(II) catalysts Ipty/Ph‐Ni and Ipty/Ph‐Pd versus symmetrical pentiptycenyl analogues Ipty‐Ni and Ipty‐Pd and symmetrical dibenzhydryl analogues Ph‐Ni and Ph‐Pd. In the Ni(II) catalyzed ethylene polymerization, new features have been revealed: (1) with the increase of steric bulk (Ph‐Ni > Ipty/Ph‐Ni > Ipty‐Ni), in a relatively long 30 min polymer molecular weights increase, yet Ipty/Ph‐Ni produces the highest molecular weight (1230 kDa) in a short 5 min; (2) with increasing steric bulk, branching density first rises and then falls, liking a downward parabola. In the Pd(II) catalyzed ethylene polymerization, increasing steric bulk enhanced activity and molecular weight or not, dependent on temperature, but usually decreased branching density. Consequently, Ipty/Ph‐Pd gave the highest activity and the highest molecular weight (412 kDa) at challenging high temperature of 70 °C. Plausible insights have been given to address these differences from previous results. Notably, unsymmetrical Ni(II) and Pd(II) catalysts also enabled copolymerizations of ethylene with various polar comonomers.
Synthesis of 3D IrRuMn Sphere as a Superior Oxygen Evolution Electrocatalyst in Acidic Environment
Authors: Aizaz Ud Din Muhammad , Irfan Syed , Dar Sami Ullah , Rizwan Syed 
Published: February 2020

AbstractThe design of a three‐dimensional structure for an Ir‐based catalyst offers a great opportunity to improve the electrocatalytic performance and maximize the use of the precious metal. Herein, a novel wet chemical strategy is reported for the synthesis of an IrRuMn catalyst with a sphere structure and porous features. In the synthetic process, the combined use of citric acid and formamide is requisite for the formation of the sphere structure. This method leads to a favorable 3D IrRuMn sphere structure with many fully exposed active sites. Furthermore, an alloying noble metal, such as Ir or Ru, with the transition metal leads to enhanced oxygen evolution reaction (OER) activity. The doping of a transition metal, such as Mn, is an interesting example, because it exhibits stability and activity in both acidic and alkaline media. For the OER, the IrRuMn sphere catalyst exhibits an overpotential of 260 mV at a current density of 10 mA cm−2 in strongly acidic 0.1 m HClO4, which is superior to that of a commercial IrO2/C catalyst. This approach provides a novel way to synthesize an Ir‐based multimetallic spherical electrocatalyst, which exhibits exceptional efficiency for the acidic OER. It will pave the way for new approaches to the practical utilization of PEM electrolyzers.
Hierarchical Tubular Architecture Constructed by Vertically Aligned CoS2‐MoS2 Nanosheets for Hydrogen Evolution Electrocatalysis
Authors: Cai Ze‐Xing , Na Jongbeom , Lin Jianjian , Alshehri Abdulmohsen Ali , Alzahrani Khalid Ahmed , Alghamdi Yousef Gamaan , Lim Hyunsoo , Zheng Jie , Xia Wei , Wang Zhong‐Li , Yamauchi Yusuke 
Published: February 2020

AbstractDeveloping efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular‐structured CoS2‐MoS2/C as efficient electrocatalysts are fabricated through a unique metal–organic framework (MOF) mediated self‐sacrificial templating. Core–shell structured MoO3@ZIF‐67 nanorods are used both as a precursor and a sacrificial template to form the one‐dimensional tubular heterostructure where vertically aligned two‐dimensional CoS2‐MoS2 nanosheets are formed on the MOF‐derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS2‐MoS2/C nanocomposites. The as‐synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd‐CoS2‐MoS2/C‐600 catalyst delivers a current density of 10 mA cm−2 at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H2SO4. Overall, this MOF‐mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.
Aqueous Synthesis of Triphenylphosphine‐Modified Gold Nanoparticles for Synergistic In Vitro and In Vivo Photothermal Chemotherapy
Authors: Benyettou Farah , Ramdas Nair Anjana , Dho Yaereen , Prakasam Thirumurugan , Pasricha Renu , Whelan Jamie , Traboulsi Hassan , Mazher Javed , Sadler Kirsten C. , Trabolsi Ali 
Published: February 2020

AbstractTriphenylphosphine (TPP) surface‐functionalized and F‐108 Pluronic‐stabilized gold nanoparticles (F‐108@TPP‐AuNPs) have been synthesized through a one‐step approach, leading to well‐defined (9.6±1.6 nm) and water‐soluble nanoparticles by microwave heating an aqueous solution of TPP‐AuICl in the presence of a Pluronic polymer under basic conditions. TPP release was negligible under physiological conditions, but enhanced significantly at an acidic pH (5.4) mimicking that of a cancer cell. Laser irradiation (532 nm) raised the temperature of an aqueous solution of F‐108@TPP‐AuNPs to 51.7 °C within 5 min, confirming efficient light‐to‐heat conversion capabilities without significant photodegradation. TEM confirmed intracellular localization of F‐108@TPP‐AuNPs in the cytosol, endosomes and lysosomes of HeLa cells. F‐108@TPP‐AuNPs were well tolerated by HeLa cells and zebrafish embryos at ambient temperatures and became toxic upon heat activation, suggesting synergistic interactions between heat and cytotoxic action by TPP.
Gasification performance of torrefied Timothy hay and spruce wood chars in a CO2 environment
Authors: Parvez Ashak Mahmud , Afzal Muhammad T. 
Published: February 2020

AbstractTimothy hay abundantly available in New Brunswick, Canada, is mostly used for animal feed and bedding. Upgrading biomass using Torrefaction method can offer benefits in its waste management, energy density and energy conversion efficiency. Temperature and residence time play an important role in the torrefaction process. Meanwhile, CO2 gasification is also a promising thermochemical conversion process due to its potential to reduce net GHG emissions and tune syngas composition. This study investigates the impact of torrefaction parameters on isothermal and non‐isothermal CO2 gasification of Timothy hay and spruce chars. Timothy hay chars exhibited higher CO2 gasification reactivity than chars from spruce. The physicochemical properties analysis indicated that higher reactivity of Timothy hay char was mainly attributed to the high amount of alkali and alkaline earth metal (AAEM) content, relatively large BET surface area, a high number ofactive sites, and a low crystalline index. Moreover, in both experimental cases, char derived through a high heating rate and high residence time conditions exhibited improved gasification performance, which was attributed to the generation of large amounts of AAEM (Ca and K) and high specific surface area. Co‐gasification results during non‐isothermal processes under CO2 showed the presence of larger interactions in coal char/Timothy hay char blends than that of coal char/spruce char blends. For both experimental conditions, interactions were enhanced once the char prepared from high heating rate and high residence time was gasified with coal char. Thus, the proposed approach is a sustainable way of conversion of Timothy hay under CO2 environment.
Does a higher American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI‐RADS) score forecast an increased risk of malignancy? A correlation study of ACR TI‐RADS with FNA cytology in the evaluation of thyroid nodules
Authors: Modi Lopa , Sun Wei , Shafizadeh Negin , Negron Raquel , Yee‐Chang Melissa , Zhou Fang , Simsir Aylin , Sheth Sheila , Brandler Tamar C. 
Published: February 2020

BackgroundUltrasound has become the initial approach to evaluating thyroid nodules, facilitating the distinction between benign and malignant nodules based on composition, echogenicity, nodule border or margin, shape, the presence of calcifications, and nodule dimensions. The American College of Radiology (ACR) recommended the Thyroid Imaging Reporting and Data System (TI‐RADS) as a classification system to standardize thyroid ultrasound reports and to predict the probability of malignancy in thyroid nodules using a scoring system (TR1‐TR5) based on multiple ultrasound characteristics and nodule size. Fine‐needle aspiration (FNA) is recommended as the next step for nodules that warrant further workup. The authors assessed the accuracy of the ACR TI‐RADS based on the corresponding FNA cytology results (Bethesda system diagnoses I‐VI).MethodsACR TI‐RADS ultrasound reports and corresponding FNA cytology diagnoses from January 1, 2018 to August 30, 2018 were evaluated.ResultsFrom January 1, 2018 to August 30, 2018, 2306 thyroid ultrasound‐guided FNAs were performed at our institution. Of 2306 cases, 361 had ACR TI‐RADS reports available. The majority of FNAs were TR4 (180; 49.9%) or TR3 (108; 29.9%). No TR2 or TR3 nodules were associated with Bethesda category V or VI diagnoses. The majority of TR4 nodules (142 of 180; 78.9%) and TR5 nodules (42 of 65; 64.6%) exhibited benign (Bethesda category II) cytology. Fourteen TR5 cases (21.5%) had malignant (Bethesda category VI) cytology.ConclusionsAlthough there were no TR2 or TR3 malignant (Bethesda category VI) diagnoses, and there were only a few malignancies in the TR4 and TR5 categories, the current results reassert the notion that the ACR TI‐RADS scoring system shows at least some correlation between benign or malignant cytology diagnoses, as illustrated by the greater number of malignant cases in the higher ACR TI‐RADS categories.
A multi‐Internet service provider game: Equilibrium, stability, and characteristics
Authors: Fu Hong , Chen Bo , Zhang Bin 
Published: February 2020

SummaryThis paper proposes a multi‐Internet service provider (ISP) game model for investigating the economic interactions among ISPs who compete or cooperate with each other for customers. The equilibrium and stability properties of the multi‐ISP game in different market scenarios, that is, competitive market, collaborative market, mixed market, and winner‐take‐all market, are investigated. Some qualitative and managerial insights into market outcomes are obtained to characterize the set of equilibria. Furthermore, numerical examples are also employed to illustrate the typical characteristics of the multi‐ISP market. The simulation results provide possible explanations for the evolution of the multi‐ISP game. The results also indicate that the constructed model can predict the main characteristics of the Internet service market in different market scenarios.
Utilising Saturated Hydrocarbon Isosteres of para Benzene in the Design of Twist‐Bend Nematic Liquid Crystals
Authors: Al‐Janabi Adam , Mandle Richard J. 
Published: February 2020

AbstractThe nematic twist‐bend (NTB) liquid crystal phase possesses a local helical structure with a pitch length of a few nanometres and is the first example of spontaneous symmetry breaking in a fluid system. All known examples of the NTB phase occur in materials whose constituent mesogenic units are aromatic hydrocarbons. It is not clear if this is due to synthetic convenience or a bona fide structural requirement for a material to exhibit this phase of matter. In this work we demonstrate that materials consisting largely of saturated hydrocarbons can also give rise to this mesophase.