bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arene C−H Activation at Aluminium(I): meta Selectivity Driven by the Electronics of SNAr Chemistry
Authors: Hicks Jamie , Vasko Petra , Heilmann Andreas , Goicoechea Jose M. , Aldridge Simon 
Published: July 2020

AbstractThe reactivity of the electron‐rich anionic AlI aluminyl compound K2[(NON)Al]2 (NON=4,5‐bis(2,6‐diisopropylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) towards mono‐ and disubstituted arenes is reported. C−H activation chemistry with n‐butylbenzene gives exclusively the product of activation at the arene meta position. Mechanistically, this transformation proceeds in a single step via a concerted Meisenheimer‐type transition state. Selectivity is therefore based on similar electronic factors to classical SNAr chemistry, which implies the destabilisation of transition states featuring electron‐donating groups in either ortho or para positions. In the cases of toluene and the three isomers of xylene, benzylic C−H activation is also possible, with the product(s) formed reflecting the feasibility (or otherwise) of competing arene C−H activation at a site which is neither ortho nor para to a methyl substituent.
Effect of copper on textural and acidic properties of hierarchical nanocrystalline ZSM‐5
Authors: O. P Farsana , Kumari Prajitha , P Aneesh 
Published: July 2020

AbstractIn this work, hierarchically porous nanocrystalline ZSM‐5 was synthesized hydrothermally. Different concentrations of copper were incorporated into the matrix by ion exchange method. The synthesized samples were characterized by means of X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR), energy‐dispersive X‐ray spectroscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy (XPS), ultraviolet (UV), 27Al magic angle spinning nuclear magnetic resonance spectroscopy, and nitrogen sorption analysis. The acid sites on the surface of Cu‐ZSM‐5 have been systematically investigated using temperature‐programmed desorption of ammonia (NH3‐TPD) and pyridine sorption followed by FTIR. The diffraction pattern obtained from XRD studies confirmed the typical Mobil Five. NH3‐TPD reveals the enhancement of acidity achieved by copper. The FTIR spectra of pyridine desorbed samples show that the intensity of bands corresponding to Lewis acidity increases by modification. The ZSM‐5 zeolite samples exhibit spherical‐shaped MFI crystal structure. The UV spectrum indicates that copper has been doped in the form of cations or in the form of oxides. XPS analysis confirms that the copper exists as Cu(I) and Cu(II). The nitrogen sorption isotherms reveal that the modified samples are mesoporous in nature. The pore volume and diameter were found to be enhanced by the modification. The better textural properties and acidic properties of the Cu‐ZSM‐5 can make it suitable for catalyzing organic reactions.
Effect of gas‐condensed phase synergistic system of 9,10‐dihydro‐9‐oxo‐10‐phosphaphenanthrene‐10‐oxide and polydopamine on flame retardancy of epoxy resin
Authors: Xu Yao , Sun Jinhao , Qian Lijun , Li Juan 
Published: July 2020

AbstractPolydopamine (PDA) was prepared by using dopamine which has good charring ability. The PDA was used as an environmentally friendly flame retardant and combined with 9,10‐dihydro‐9‐oxo‐10‐phosphaphenanthrene‐10‐oxide (DOPO) to improve the flame retardancy of epoxy (EP) resin. The flame retardancy and thermal stability of EP composites were researched by UL‐94 vertical burning, limiting oxygen index (LOI), cone calorimetry tests, and thermal gravimetric analyzer. Adding DOPO alone requires 6% to make EP obtain the UL‐94 V0. If DOPO and PDA are combined, only 4% is needed to make EP obtain the UL‐94 V0, which suggests that there is good synergistic effect between them. Moreover, the peak of heat release rate of EP/DOPO/PDA composites is less than that of EP/DOPO composites. The reactions among EP, DOPO, and PDA reduce the release of combustible gases at the early stage of degradation; at the same time, DOPO volatilize to the gas phase, quench the free radicals, and the combustion can be stopped. In addition, due to the decrease of the amount of PDA/DOPO, the EP composite can get a higher glass transition temperature, but due to the aggregation of PDA in EP, the tensile property of EP composite decreases.
Cross‐linked Salen‐based polyphosphazenes (Salen‐PZNs) enhancing the fire resistance of epoxy resin composites
Authors: Zhang Yabin , Cui Jinfeng , Wang Lurong , Yu Hailong , Li Fuchong , Yang Baoping , Guo Junhong , Mu Bo , Tian Li 
Published: July 2020

AbstractIn this work, two cross‐linked Salen‐based polyphosphazenes (Salen‐PZNs: Salen‐PZN‐1 microspheres and layered Salen‐PZN‐2), which contains Salen‐Schiff base and phosphazene components, were synthesized. The results showed that the peak heat release rate and total smoke production of 3% Salen‐PZN‐1/epoxy resin (EP) (3 wt% addition) were reduced by 23.8% and 87.3%, respectively. Meanwhile, after introducing the layered Salen‐PZN‐2 into EP, efficient flame resistance was obtained. The results of thermogravimetric analysis/infrared spectrometry proved that the harmful gasses of 5% Salen‐PZN‐1/EP composites were reduced during the combustion. The possible flame retardancy mechanism was considered to be the synergy of phosphate group catalysis, release of nitrogen‐containing noncombustible gasses and gas phase quenching. Therefore, this work provides a method for preparing polymers with highly efficient flame‐retardant properties.
An algorithm for computing robust forward invariant sets of two dimensional nonlinear systems
Authors: Mukhopadhyay Shayok , Zhang Fumin 
Published: July 2020

SummaryRobustness of nonlinear systems can be analyzed by computing robust forward invariant sets (RFISs). Knowledge of the smallest RFIS of a system, can help analyze system performance under perturbations. A novel algorithm is developed to compute an approximation of the smallest RFIS for two‐dimensional nonlinear systems subjected to a bounded additive disturbance. The problem of computing an RFIS is formulated as a path planning problem, and the algorithm developed plans a path which iteratively converges to the boundary of an RFIS. Rigorous mathematical analysis shows that the proposed algorithm terminates in a finite number of iterations, and that the output of the proposed algorithm is an RFIS. Simulations are presented to illustrate the proposed algorithm, and to support the mathematical results. This work may aid future development, for use with higher dimensional systems.
Using COVID‐19 as a teaching tool in a time of remote learning: A workflow for bioinformatic approaches to identifying candidates for therapeutic and vaccine development
Authors: Bryce Samantha , Heath Kevin N. , Issi Luca , Ryder Elizabeth F. , P. Rao Reeta 
Published: July 2020

AbstractThe COVID‐19 pandemic has led to an urgent need for engaging computational alternatives to traditional laboratory exercises. Here we introduce a customizable and flexible workflow, designed with the SARS CoV‐2 virus that causes COVID‐19 in mind, as a means of reinforcing fundamental biology concepts using bioinformatics approaches. This workflow is accessible to a wide range of students in life science majors regardless of their prior bioinformatics knowledge, and all software is freely available, thus eliminating potential cost barriers. Using the workflow can thus provide a diverse group of students the opportunity to conduct inquiry‐driven research. Here we demonstrate the utility of this workflow and outline the logical steps involved in the identification of therapeutic or vaccine targets against SARS CoV‐2. We also provide an example of how the workflow may be adapted to other infectious microbes. Overall, our workflow anchors student understanding of viral biology and genomics and allows students to develop valuable bioinformatics expertise as well as to hone critical thinking and problem‐solving skills, while also creating an opportunity to better understand emerging information surrounding the COVID‐19 pandemic.
Quantification of 10 bioactive components of Yazhangsan in rat plasma by LC–MS/MS and its application
Authors: Zhang Qing , Chen Sha , Liu An , Wang Yuesheng 
Published: July 2020

AbstractYazhangsan (YZS) is a common prescription for the treatment of cough and asthma caused by wind‐cold. The purpose of this study was to investigate the pharmacokinetic profiles of 10 bioactive components in YZS. A simple, sensitive and reliable high‐performance liquid chromatography coupled with a triple‐quadruple mass spectrometry method (LC–MS/MS) was developed and fully validated in this study for the measurement of these 10 bioactive compounds in rat plasma. One‐step protein precipitation method using methanol was applied to the treatment of rat plasma samples. Chromatographic separation was conducted on a C18 column by gradient elution, and water (containing 0.1% formic acid) and acetonitrile were chosen as the mobile phase. The analytes were quantified by using a mass spectrometer in multiple reaction monitoring scanning mode, and electrospray ionization was performed in positive and negative ion modes. The established method met the requirements for the quantification of these 10 bioactive compounds in biological samples, and it was successfully applied to the pharmacokinetic study of 10 components in rats after the intragastrical administration of YZS. This study will lay a foundation for the investigation of the mechanism of action of YZS and provide useful data for the rational use of YZS in clinical.
A genome‐scale CRISPR knock‐out screen in chronic myeloid leukemia identifies novel drug resistance mechanisms along with intrinsic apoptosis and MAPK signaling
Authors: Lewis Matthieu , Prouzet‐Mauléon Valérie , Lichou Florence , Richard Elodie , Iggo Richard , Turcq Béatrice , Mahon François‐Xavier 
Published: July 2020

AbstractUnderstanding resistance mechanisms in cancer is of utmost importance for the discovery of novel “druggable” targets. Efficient genetic screening, now even more possible with CRISPR‐Cas9 gene‐editing technology, next‐generation sequencing and bioinformatics, is an important tool for deciphering novel cellular processes, such as resistance to treatment in cancer. Imatinib specifically eliminates chronic myeloid leukemia (CML) cells by targeting and blocking the kinase activity of BCR‐ABL1; however, resistance to treatment exists. In order to discover BCR‐ABL1 independent mechanisms of imatinib resistance, we utilized the genome‐scale CRISPR knock‐out library to screen for imatinib‐sensitizing genes in vitro on K562 cells. We revealed genes that seem essential for imatinib‐induced cell death, such as proapoptotic genes (BIM, BAX) or MAPK inhibitor SPRED2. Specifically, reestablishing apoptosis in BIM knock‐out (KO) cells with BH3 mimetics, or inhibiting MAPK signaling in SPRED2 KO cells with MEK inhibitors restores sensitivity to imatinib. In this work, we discovered previously identified pathways and novel pathways that modulate response to imatinib in CML cell lines, such as the implication of the Mediator complex, mRNA processing and protein ubiquitinylation. Targeting these specific genetic lesions with combinational therapy can overcome resistance phenotypes and paves the road for the use of precision oncology.
Patient and caregiver benefit‐risk preferences for nonmetastatic castration‐resistant prostate cancer treatment
Authors: Srinivas Sandy , Mohamed Ateesha F. , Appukkuttan Sreevalsa , Botteman Marc , Ng Xinyi , Joshi Namita , Tsai Jui‐Hua , Fang Jarjieh , Waldeck A. Reginald , Simmons Stacey J. 
Published: July 2020

AbstractBackgroundRecently approved second‐generation androgen receptor inhibitors (SGARIs) for non‐metastatic castration‐resistant prostate cancer (nmCRPC) have similar efficacy but differ in safety profiles. We used a discrete choice experiment (DCE) to examine how nmCRPC patients and caregivers perceive the benefits versus risks of these new treatments.MethodsAn online DCE survey with 14 treatment choice questions was administered to nmCRPC patients and caregivers. Each choice question compared two hypothetical medication profiles varying in terms of 5 safety attributes (risk or severity of adverse events [AEs]: fatigue, skin rash, cognitive problems, serious fall, and serious fracture) and two efficacy attributes (duration of overall survival [OS] and time to pain progression). Random parameters logit models were used to estimate each attribute's relative importance. We also estimated the amounts of OS that respondents were willing to forego for a reduction in AEs.ResultsIn total, 143 nmCRPC patients and 149 caregivers viewed the AEs in following order of importance (most to least): serious fracture, serious fall, cognitive problems, fatigue, and skin rash. On average, patients were willing to trade 5.8 and 4.0 months of OS to reduce the risk of serious fracture and fall, respectively, from 3% to 0%; caregivers were willing to trade 6.6 and 5.4 months of OS.ConclusionsnmCRPC patients and caregivers preferred treatments with lower AE burdens and were willing to forego OS to reduce the risk and severity of AEs. Our results highlight the importance of carefully balancing risks and benefits when selecting treatments in this relatively asymptomatic population.
In Silico Anticipation of Metabolic Pathways Extended to Organic Chemistry Reactions: A Case Study with Caffeine Alkaline Hydrolysis and The Origin of Camellimidazoles
Authors: Turpin Victor , Beniddir Mehdi A. , Genta‐Jouve Grégory , Skiredj Adam , Gallard Jean‐François , Leblanc Karine , Le Pogam Pierre , Poupon Erwan 
Published: July 2020

AbstractCamellimidazoles A–C were recently reported as natural substances in Keemun black tea. Although a “biosynthetic” route to these intriguing imidazole dimers was proposed from caffeine by the authors in this seminal report, we envisioned that a artefactual scenario, consisting of alkaline hydrolysis of caffeine and spontaneous cascade reactions with a methylene donor such as formaldehyde or methylene chloride, could also have led to their formation. To capture the diversity of molecules obtained under these conditions (i.e. alkaline treatment of caffeine/formaldehyde), an in silico MetWork‐based pipeline was implemented, highlighting the sought‐after camellimidazoles B and C. A wealth of further compounds were also tagged, notably comprising the herein newly described and unnatural camellimidazoles D–F that were subsequently confirmed as anticipated in silico upon extensive spectroscopic analyses. Likewise, camellimidazoles B and C could also be obtained using methylene chloride as an alternative methylene donor which may also have occurred in the initial phytochemical pipeline that implied this solvent. The current investigation emphasizes the fitness of MetWork tagging to extend the logic of in silico anticipation of metabolic pathways to organic chemistry reactions.
Compressor Cost Optimization Based on Extended Annual Load Duration Curves
Authors: Geitner Christian , Waesker Markus , Doetsch Christian 
Published: July 2020

AbstractVolatile exhaust gas flows in the steel industry are potential resources to reduce greenhouse gas emissions. The project Carbon2Chem® analyzes possible carbon capture and utilization processes for the gas streams of a steel mill. Therefore, compressors for volatile gas flows are required in all process concepts. The large amount and volatility of the gas as well as inert compounds contained therein make the compressors the pivotal cost block. This approach extends the annual load duration curve to optimize the compressor cost.
Heat on – Calibration of IR Spectroscopy at Process Conditions for Continuous Esterification
Authors: Schnoor Johann‐Kilian , Schulte Lennard D. , Liauw Marcel A. 
Published: July 2020

AbstractThis work tries to close the gap between continuous synthesis, measurement, calibration, and analysis on R&D scale. By introducing new calibration methods, the full potential of inline ATR‐FTIR spectroscopy in continuous reactor setups is unraveled. A fast, fully automated calibration of the reaction mixtures is carried out at process conditions. The use of different compositions underlines the robustness of this calibration method, which was used for the determination of kinetic parameters. The conversion‐based calibration significantly increased the precision of the analysis. In difference, the new method only requires the preparation of two calibration mixtures. By that, this method can also be applied to large‐scale processes and allows the use of a single measurement setup from R&D to industrial scale.
Soft sensor development based on improved just‐in‐time learning and relevant vector machine for batch processes
Authors: Wang Jianlin , Qiu Kepeng , Guo Yongqi , Wang Rutong , Zhou Xinjie 
Published: July 2020

AbstractThe online measurement of key quality variables based on soft sensors plays a critical role in ensuring the safety and stability of batch processes. Recently, the relevant vector machine (RVM) was introduced into soft sensors for batch processes. However, the RVM‐based soft sensor has limitations in addressing the time‐varying, high‐dimensional, and dynamic data of batch processes. To address these issues, based on improved just‐in‐time learning and the relevant vector machine, an adaptive soft sensor, termed IJITL‐RVM, is proposed in this paper. The IJITL‐RVM integrates the IJITL algorithm and the RVM algorithm into a unified online modelling framework with the ability to perform adaptive updating and dynamic modelling. First, to enhance the performance of online prediction, an IJITL is designed to select modelling data based on the support vector data description (SVDD) algorithm and the kernel trick. Based on the comprehensive consideration of the strong nonlinearity and high dimensionality of process data, the IJITL can adaptively and accurately select the modelling data. Afterward, a local model is established by using the RVM for online prediction. Three applications, including a numerical simulation example, some UCI datasets, and a penicillin fermentation process, are provided to illustrate the superiority of the IJITL‐RVM‐based soft sensor.
Mid‐infrared spectroscopy as a tool for real‐time monitoring of ethanol absorption in glycols
Authors: Rodrigues Kaio C. S. , Veloso Ivan I. K. , Ribeiro Marcelo P. A. , Cruz Antonio J. G. , Badino Alberto C. 
Published: July 2020

AbstractFast, simple, accurate, and inexpensive methods for obtaining analyte concentration data are desirable in the industrial sector. In the present study, the use of Fourier transform mid‐infrared (FT‐MIR) spectroscopy, combined with partial least squares (PLS) regression, was investigated as a tool for real‐time monitoring of processes of ethanol absorption in glycols. Calibration was performed using simple synthetic samples containing ethanol, water, and monoethylene glycol (MEG) or diethylene glycol (DEG). The PLS models presented excellent performance, with correlation coefficients (R2) close to unity and root‐mean‐square errors of cross‐validation (RMSECV) and prediction (RMSEP) lower than 2% of the calibration data ranges for both analytes (ethanol and water) in both absorbents (MEG and DEG). The monitoring technique developed has potential to be applied in absorption processes and could also be used in other large‐scale unit operations, providing information in real time and enhancing process control.
Modelling study of emulsion latex coagulation processes in coagulators
Authors: Cheng Dang , Sheibat‐Othman Nida , McKenna Timothy F. L. 
Published: July 2020

AbstractThis paper presents a numerical study of emulsion latex coagulation processes in continuous coagulators based on the full computational fluid dynamics approach. The RANS approach together with the k‐ε turbulence model was used to describe the detailed flow field in the coagulators. The coagulant mixing process was modelled by the convection‐diffusion equation and the emulsion latex coagulation process was formulated by the population balance equation of the particle size with a coagulation kernel including a perikinetic and orthokinetic combined mechanism. The flow and coagulation models were independently validated by means of comparing simulated results to the relevant experimental data from the literature. A series of simulations were carried out to study the effects of coagulator bottom shape, salt solution feeding location, residence time and agitation speed, as well as the influence of four typical scale‐up criteria on the latex particle coagulation process. The presented results would be helpful for the relevant process design, development, and scale‐up of continuous latex coagulators.
Outcomes of ST‐elevation myocardial infarction by age and sex in a low‐income urban community: The Montefiore STEMI Registry
Authors: Bortnick Anna E. , Shahid Muhammad , Shitole Sanyog G. , Park Michael , Broder Anna , Rodriguez Carlos J. , Scheuer James , Faillace Robert , Kizer Jorge R. 
Published: July 2020

AbstractObjectivesTo compare outcomes by age and sex in race/ethnic minorities presenting with ST‐elevation myocardial infarction (STEMI), as studies are limited.MethodsWe studied sociodemographics, management, and outcomes in 1208 STEMI patients evaluated for primary percutaneous coronary intervention between 2008 and 2014 at Montefiore Health System (Bronx, NY). A majority of patients self‐identified as nonwhite, and nearly two‐thirds were young (<45 years) or middle‐aged (45‐64 years).ResultsRisk factors varied significantly across age groups; with more women and non‐Hispanic whites, hypertension, diabetes, dyslipidemia, prior cardiovascular disease, non‐sinus rhythm, and collagen vascular disease in the older age group (≥65 years); and higher body mass index, smoking, cocaine use, human immunodeficiency virus (HIV) infection and family history of heart disease in the young. Younger women had lower summary socioeconomic scores than younger men. Middle‐aged women had more obesity and dysmetabolism, while men had more heavy alcohol use. There was greater disease severity with increasing age; with higher cardiac biomarkers, 3‐vessel disease, cardiogenic shock, and coronary artery bypass grafting. Older patients had higher rates of death and death or readmission over 4.3 (interquartile range 2.4, 6.0) years of follow‐up. Middle‐aged women had higher rates of death or any readmission than men, but these differences were not significant after adjustment.ConclusionsThese findings indicate a high burden of risk factors in younger adults with STEMI from an inner‐city community. Programs to target sociobehavioral factors in disadvantaged settings, including substance abuse, obesity, and risk of HIV, are necessary to more effectively address health disparities in STEMI and its adverse consequences.