bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of recovery of volatile fatty acids and mixed ketones as alternative downstream processes for acetogenisis fermentation
Authors: Petersen Abdul M. , Franco Telma , Görgens Johann F. 
Published: July 2018

AbstractCarboxylates produced by the acetogenisis fermentation of pre‐treated lignocelluloses are precursors to bio‐based products that are alternatives to second‐generation biofuels for biomass valorization. This paper compares the techno‐economic indicators for recovering either mixed ketones or mixed volatile fatty acid (VFA) products from the carboxylates in a fermentation broth through process simulation and financial modeling.This study considers scenarios for (i) an efficient process for ketone production (K‐P) involving dehydration, thermal conversion, and condensation already established in the literature; (ii) VFA production (VFA‐P) with conventional methods of carboxylate acidification and separation; and (iii) advanced VFA acidification and separation methods. In conventional acidification, using mineral acids and calcium alkalis results in wastes; while in advanced acidification, the acids and bases are regenerated. Conventional separation relies on ethyl‐acetate extraction, while advanced separation relies on amine extraction.Scenarios are compared in terms of energy and chemical use, and the internal rates of return (IRR) determined with price ranges assumed for mixed VFAs and mixed ketones.Thus, with optimistic product prices, K‐P and VFA‐P with conventional acidification‐separation have indentical IRRs at 35%, but K‐P is favorable due to the chemical‐intensiveness and waste generation of the VFA‐P. Using advanced acidification and separation could possibly improve the IRR of VFA‐P to 39%, with a capital investment of 2% above that of K‐P, which was estimated at US$ 293 million. Otherwise, a previously patented scheme that integrated acidification and separation based on amine complexation could also produce a VFA process that is environmentally and economically feasible. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Transport mechanism of ursodeoxycholic acid in human placental BeWo cells
Authors: Xia Yanming , Dong Ying , Zhao Xiaoli , Di Liuqing , Li Junsong 
Published: July 2018

AbstractUrsodeoxycholic acid (UDCA) is a first‐line drug to treat intrahepatic cholestasis of pregnancy (ICP). However, its effects on the fetus are not clearly known. To better guide its clinical use, we aimed to study the mechanism underlying the placental transport of UDCA. The uptake and efflux of UDCA across placental apical membranes were studied using BeWo cells; effects of different exposure durations, UDCA concentrations, temperatures, and inhibitors of transporters were studied. A transwell assay was performed, and UDCA concentration in both fetal and maternal sides was measured using LC–MS/MS. Higher unidirectional transport of UDCA was observed in the basolateral‐to‐apical direction than in the apical‐to‐basolateral direction. Ko143 and verapamil, which are typical inhibitors of efflux transporters, significantly increased UDCA transport from different directions. UDCA uptake from the apical membrane of BeWo cells was time‐dependent, but sodium‐independent. It was inhibited by inhibitors of energy metabolism and of organic anion transporters, indicating an active transport mechanism. UDCA uptake from the apical membranes of BeWo cells could be mediated by organic anion‐transporting polypeptides, whereas its efflux could be mediated by breast cancer resistance protein and multidrug resistant protein 3. The results of the present study may provide a basis for UDCA use in pregnancy.
Azide‐ and Alkyne‐Bearing Metabolic Chemical Reporters of Glycosylation Show Structure‐Dependent Feedback Inhibition of the Hexosamine Biosynthetic Pathway
Authors: Walter Lisa A. , Batt Anna R. , Darabedian Narek , Zaro Balyn W. , Pratt Matthew R. 
Published: July 2018

AbstractMetabolic chemical reporters (MCRs) of protein glycosylation are analogues of natural monosaccharides that bear reactive groups, like azides and alkynes. When they are added to living cells and organisms, these small molecules are biosynthetically transformed into nucleotide donor sugars and then used by glycosyltransferases to modify proteins. Subsequent installation of tags by bioorthogonal chemistries can then enable the visualization and enrichment of these glycoproteins. Although this two‐step procedure is powerful, the use of MCRs has the potential to change the endogenous production of the natural repertoire of donor sugars. A major route for the generation of these glycosyltransferase substrates is the hexosamine biosynthetic pathway (HBP), which results in uridine diphosphate N‐acetylglucosamine (UDP‐GlcNAc). Interestingly, the rate‐determining enzyme of the HBP, glutamine fructose‐6‐phosphate amidotransferase (GFAT), is feedback inhibited by UDP‐GlcNAc. This raises the possibility that a build‐up of UDP‐MCRs would block the biosynthesis of UDP‐GlcNAc, resulting in off target effects. Here, we directly test this possibility with recombinant human GFAT and a small panel of synthetic UDP‐MCRs. We find that MCRs with larger substitutions at the N‐acetyl position do not inhibit GFAT, whereas those with modifications of the 2‐ or 6‐hydroxy group do. These results further illuminate the considerations that should be applied to the use of MCRs.
Reversible Segregation of Ni in LaFe0.8Ni0.2O3±δ During Coke Removal
Authors: Steiger Patrick , Nachtegaal Maarten , Kröcher Oliver , Ferri Davide 
Published: July 2018

AbstractThe deactivation of supported nickel catalysts by coking is an important technological subject for many chemical processes, especially when high concentrations of unsaturated hydrocarbons are present in the feed gas. Here, the reversible segregation of Ni from a LaFeO3±δ perovskite‐type host lattice was exploited to completely recover a LaFe0.8Ni0.2O3±δ catalyst after it had been deliberately subjected to severe carbon deposition during CO2 methanation in ethylene rich feed gas for several hours. Temperature programmed reduction, X‐ray diffraction, electron microscopy, X‐ray absorption spectroscopy and catalytic activity tests were used to follow the catalyst structure along the various steps of reduction, reaction, coking and subsequent regeneration, while Raman spectroscopy and electron microscopy were used to characterize the nature of the carbon deposits. It is shown that upon reduction Ni atoms segregate to the surface of the perovskite to form catalytic active Ni particles. Oxidation stimulates Ni atoms to readopt the coordination environment of Fe in the perovskite matrix. This property persisted after severe catalyst deactivation by filamentous, partially graphitic carbon. It is demonstrated that simple catalyst reoxidation can be applied to oxidize all carbon deposits while additionally reverting segregated Ni back into the host lattice, thus protecting Ni from particle growth and resultant long‐term loss of catalyst activity over multiple regeneration cycles.
Insight by In Situ Gas Electron Microscopy on the Thermal Behaviour and Surface Reactivity of Cobalt Nanoparticles
Authors: Dembélé Kassiogé , Bahri Mounib , Melinte Georgian , Hirlimann Charles , Berliet Adrien , Maury Sylvie , Gay Anne‐Sophie , Ersen Ovidiu 
Published: July 2018

AbstractHere the thermal behaviour and the surface reactivity of cobalt catalysts supported by alumina‐silica and promoted by platinum were investigated by in situ transmission electron microscopy (in situ TEM) in a syngas environment. At the standard operating temperature of 220 °C, atomic diffusion and sintering processes onto the support are quite limited on the time scale of the TEM experiment. At temperatures between 350 and 450 °C, particles encapsulation occurred due to a higher CO dissociation and conversion into graphitic layers. Beyond 500 °C, carbon nanotubes (CNTs) growth is activated and the particles undergo (i) morphological changes through continuous elongation and contraction; and (ii) microstructural changes with the appearance of cobalt carbide. By comparing reactions under pure CO and a mixture CO−H2, it was shown that the addition of dihydrogen to CO increased the rate of CNTs growth and modified the structure of the nanotubes. These results clearly demonstrate the strong ability of the in situ TEM to provide the main lines of the reactivity synopsis of nanocatalysts at a nanometric scale under temperature and reactive gas.
Strong Metal Support Interaction as a Key Factor of Au Activation in CO Oxidation
Authors: Klyushin Alexander Yu. , Jones Travis E. , Lunkenbein Thomas , Kube Pierre , Li Xuan , Hävecker Michael , Knop‐Gericke Axel , Schlögl Robert 
Published: July 2018

AbstractWe address the question of the nature of Au NP activation and through a combination of experimental and theoretical techniques. In‐situ XPS measurements of Au/TiO2 during CO oxidation show high catalytic activity can be associated with the formation of an ionic Au species. DFT calculations performed on Au/TiO2 show that the formation of such ionic Au is due to a strong metal‐support interaction between Au and reduced and defective TiO2. TEM supports these findings, indicating the formation of an overlayer of transition metal oxide support on Au NPs after CO oxidation. These results suggest TiO2 lattice oxygen is involved directly in CO oxidation, which was confirmed with labeled 18O2 experiments.
Interfacial Friction Factor Prediction in Vertical Annular Flow Based on the Interface Roughness
Authors: Sun Baojiang , Zhang Zhennan , Wang Zhiyuan , Xiang Hua 
Published: July 2018

AbstractCorrelations for the interface roughness are proposed for conditions without or with disturbance waves for vertical annular flow. The decisive role of interface roughness in the interfacial friction factor is specified through a comparison of ten correlations for the interfacial friction factor with an experimental database. The effect of the disturbance wave on the interface roughness is analyzed to figure out the influence parameters, which are the superficial gas and liquid Reynolds numbers for conditions without disturbance waves and gas core and liquid film Reynolds numbers for conditions with disturbance waves. The proposed correlations improve the prediction precision of the interfacial friction factor, especially in smooth and transitional regimes.
Microreactor Technology as a Tool for the Synthesis of a Glitazone Drug Intermediate
Authors: Pinheiro Danilo da Silva , Silva Renan Rodrigues de Oliveira , Calvo Paulo Victor Cuesta , Fernandes da Silva Milena , Converti Attilio , Palma Mauri Sergio Alves 
Published: July 2018

AbstractOne of the bottlenecks in the pharmaceutical industry is drug production scale‐up, which can be performed by microreactor technology. Such an approach was applied to the synthesis of (Z)‐5‐(4‐hydroxybenzylidene)thiazolidine‐2,4‐dione, a bioactive aromatic heterocyclic compound belonging to the class of glitazones. n‐Propanol was the best solvent and piperidine the best catalyst for the batch reaction, which was completed in only 5.5 h. In the microreactor, the productivity was almost independent of solvent. The microreactor behaved as a plug‐flow reactor and operated at a steady state for ten hours without efficiency loss. The results suggest that microreactors may replace batch reactors in scaling up drug production.
Opportunities for Low‐Cost Particulate Matter Sensors in Filter Emission Measurements
Authors: Schwarz Almuth D. , Meyer Jörg , Dittler Achim 
Published: July 2018

AbstractCommercial low‐cost sensors for particulate matter measurements are a fast growing market and find many applications in the particulate matter (PM) immission characterization in the environment. This application includes uncontrolled factors such as humidity, making the devices more prone to errors. These factors are controllable in closed emission control applications, turning these affordable sensors into potential monitoring devices for exhaust concentrations. Time‐resolved PM emissions of a surface filter were measured at various concentration levels. The suitability and limitations of a SDS011 PM2.5 low‐cost sensor were evaluated by comparing its PM readings to a welas® 2100 sensor by Palas®. Experimental setup and results are presented and further discussed in this paper.
Polymorphic Phase Transitions in Carbamazepine and 10,11‐Dihydrocarbamazepine
Authors: Clout Alexander E. , Buanz Asma B. M. , Gaisford Simon , Williams Gareth R. 
Published: July 2018

AbstractTemperature‐induced phase transitions in carbamazepine (CBZ) and 10,11‐dihydrocarbamazepine (DHC) were studied by simultaneous differential scanning calorimetry–X‐ray diffraction in this work. The transitions generally involve a transitional melt phase which is quickly followed by recrystallisation. The expansions of the unit cell as a function of temperature could be quantified and allow us to determine a directional order of stability in relation to the lattice constants. Dihydrocarbamazepine form II undergoes a conversion to form I by a localised melt phase. Carbamazepine (CBZ) form IV converts to form I at 182 °C, again by a localised intermediate melt phase. CBZ form II converted to form I at 119 °C by a pathway that appears to have included some melting, and form III underwent a part melt‐recrystallisation and a part sublimation‐recrystallisation to form I.
Near‐Infrared Light Responsive Imaging‐Guided Photothermal and Photodynamic Synergistic Therapy Nanoplatform Based on Carbon Nanohorns for Efficient Cancer Treatment
Authors: Gao Cunji , Dong Pei , Lin Zhaoxing , Guo Xiaolu , Jiang Bang‐Ping , Ji Shichen , Liang Hong , Shen Xing‐Can 
Published: July 2018

AbstractIndocyanine green (ICG) is an effective light absorber for laser‐mediated photodynamic therapy. However, applications of ICG are limited due to its rapid degradation and poor photostability in water. Herein, we report the development of a multifunctional nanoplatform by coating ICG on the surface of single‐walled carbon nanohorns (SWNHs) through π–π stacking, obtaining SWNH‐ICGs with high solubility and stability under physiological conditions. The SWNH‐ICGs could be used as a single nanoplatform to simultaneously produce satisfactory hyperthermia and reactive oxygen species under near‐infrared (NIR) laser irradiation. In addition, the SWNH‐ICGs not only improved the photostability of ICG in different media, but also protected it from light degradation. The SWNH‐ICGs exhibited highly efficient thermal/photoacoustic (PA) imaging‐guided photothermal therapy (PTT) and photodynamic therapy (PDT) effects, even under low‐power laser irradiation (0.3 W cm−2) in vitro. Combined PTT and PDT effectively killed triple‐negative breast cancer 4T1 cells, demonstrating a markedly improved and synergistic therapeutic effect compared to PTT or PDT alone. Furthermore, significant tumor growth inhibition as well as tumor cell death were observed following PTT/PDT at 808 nm laser irradiation, confirming the synergistic effects of SWNH‐ICGs over free ICG in vivo. This facile and simple methodology for thermal/PA imaging‐guided PTT/PDT suggests that SWNH‐ICGs may serve as an effective nanoplatform for cancer therapy.
Iridium‐Induced Regioselective B−H and C−C Activations at Azo‐Substituted o‐Carboranes
Authors: Gao Yang , Cui Peng‐Fei , Aznarez Francisco , Jin Guo‐Xin 
Published: July 2018

AbstractInvited for the cover of this issue is the group of Guo‐Xin Jin at Fudan University. The image depicts the process by which a caterpillar becomes a butterfly through struggle and effort. Read the full text of the article at 10.1002/chem.201801381.
Photodissociation of Sodium Iodide Clusters Doped with Small Hydrocarbons
Authors: Bersenkowitsch Nina K. , Ončák Milan , Heller Jakob , van der Linde Christian , Beyer Martin K. 
Published: July 2018

AbstractMarine aerosols consist of a variety of compounds and play an important role in many atmospheric processes. In the present study, sodium iodide clusters with their simple isotope pattern serve as model systems for laboratory studies to investigate the role of iodide in the photochemical processing of sea‐salt aerosols. Salt clusters doped with camphor, formate and pyruvate are studied in a Fourier transform ion cyclotron resonance mass spectrometer (FT‐ICR MS) coupled to a tunable laser system in both UV and IR range. The analysis is supported by ab initio calculations of absorption spectra and energetics of dissociative channels. We provide quantitative analysis of IRMPD measurements by reconstructing one‐photon spectra and comparing them with the calculated ones. While neutral camphor is adsorbed on the cluster surface, the formate and pyruvate ions replace an iodide ion. The photodissociation spectra revealed several wavelength‐specific fragmentation pathways, including the carbon dioxide radical anion formed by photolysis of pyruvate. Camphor and pyruvate doped clusters absorb in the spectral region above 290 nm, which is relevant for tropospheric photochemistry, leading to internal conversion followed by intramolecular vibrational redistribution, which leads to decomposition of the cluster. Potential photodissociation products of pyruvate in the actinic region may be formed with a cross section of <2×10−20 cm2, determined by the experimental noise level.
A Bifunctional MOF Catalyst Containing Metal–Phosphine and Lewis Acidic Active Sites
Authors: Prasad Ram R. R. , Dawson Daniel M. , Cox Paul A. , Ashbrook Sharon E. , Wright Paul A. , Clarke Matthew L. 
Published: July 2018

AbstractPost‐synthetic modification of the hafnium metal–organic framework MOF‐808(Hf) to include triarylphosphine ligands is reported. Sulfonated phenylphosphines are incorporated without oxidation to give a “MOF ligand” that can complex late transition metals such as Ir and Rh to give a bifunctional catalyst containing both metal–phosphine complexes and the Lewis acidic framework hafnium metal sites. The metallated phosphine‐bearing MOFs act as fully heterogeneous bifunctional catalysts for tandem reductive amination and hydroaminomethylation reactions.
Bayesian MAP estimation using Gaussian and diffused‐gamma prior
Authors: Goh Gyuhyeong , Dey Dipak K. 
Published: July 2018

AbstractFor sparse and high‐dimensional data analysis, a valid approximation of‐norm has played a key role. However, there is not much study on the‐norm approximation in the Bayesian literature. In this article, we introduce a new prior, called Gaussian and diffused‐gamma prior, which leads to a nice‐norm approximation under the maximum a posteriori estimation. To develop a general likelihood function, we utilize a general class of divergence measures, called Bregman divergence. Due to the generality of Bregman divergence, our method can handle various types of data such as count, binary, continuous, etc. In addition, our Bayesian approach provides many theoretical and computational advantages. To demonstrate the validity and reliability, we conduct simulation studies and real data analysis.The Canadian Journal of Statistics46: 399–415; 2018 © 2018 Statistical Society of Canada
Power and performance optimization in FPGA‐accelerated clouds
Authors: Tesfatsion Selome Kostentions , Proaño Julio , Tomás Luis , Caminero Blanca , Carrión Carmen , Tordsson Johan 
Published: July 2018

SummaryEnergy management has become increasingly necessary in data centers to address all energy‐related costs, including capital costs, operating expenses, and environmental impacts. Heterogeneous systems with mixed hardware architectures provide both throughput and processing efficiency for different specialized application types and thus have a potential for significant energy savings. However, the presence of multiple and different processing elements increases the complexity of resource assignment. In this paper, we propose a system for efficient resource management in heterogeneous clouds. The proposed approach maps applications' requirement to different resources reducing power usage with minimum impact on performance. A technique that combines the scheduling of custom hardware accelerators, in our case, Field‐Programmable Gate Arrays (FPGAs) and optimized resource allocation technique for commodity servers, is proposed. We consider an energy‐aware scheduling technique that uses both the applications' performance and their deadlines to control the assignment of FPGAs to applications that would consume the most energy. Once the scheduler has performed the mapping between a VM and an FPGA, an optimizer handles the remaining VMs in the server, using vertical scaling and CPU frequency adaptation to reduce energy consumption while maintaining the required performance. Our evaluation using interactive and data‐intensive applications compare the effectiveness of the proposed solution in energy savings as well as maintaining applications performance, obtaining up to a 32% improvement in the performance‐energy ratio on a mix of multimedia and e‐commerce applications.
Store‐Operated Calcium Entry Mediated by ORAI and STIM
Authors: Nguyen Nhung T. , Han Weidong , Cao Wen‐Ming , Wang Youjun , Wen Shufan , Huang Yun , Li Minyong , Du Lupei , Zhou Yubin 
Published: July 2018

ABSTRACTThe calcium release‐activated calcium (CRAC) channel, composed of ORAI and stromal interaction molecules (STIM), represents a prototypical example of store‐operated calcium entry in mammals. The ORAI‐STIM signaling occurs at membrane contact sites formed by close appositions between the endoplasmic reticulum (ER) and the plasma membrane. ORAI1 is a four‐pass transmembrane protein that forms a highly calcium‐selective ion channel in the plasma membrane. STIM1 is an ER‐resident, a single‐pass transmembrane protein that serves as a calcium sensor within the ER lumen and a potent activator of ORAI1 calcium channels. The intricate interplay between ORAI and STIM controls calcium entry into cells to regulate a myriad of physiological processes. We highlight herein the current knowledge on the structure‐function relationship of CRAC channel, with a focus on key structural elements that mediate STIM1 conformational switch and the dynamic coupling between STIM1 and ORAI1. Furthermore, we discuss the physiological roles of STIM‐ORAI signaling in various tissues and organs, as well as major pathological conditions arising from loss‐ or gain‐of‐function mutations in human ORAI1 and STIM1. © 2017 American Physiological Society.Compr Physiol8:981‐1002, 2018.