bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of DMSO Solvent Treatments on the Performance of PEDOT:PSS Based Organic Electrochemical Transistors
Authors: Lingstedt Leona V. , Ghittorelli Matteo , Lu Hao , Koutsouras Dimitrios A. , Marszalek Tomasz , Torricelli Fabrizio , Crăciun N. Irina , Gkoupidenis Paschalis , Blom Paul W. M. 
Published: February 2019

AbstractThe conductivity of poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) can be strongly enhanced by treatment with high boiling solvents as dimethyl sulfoxide (DMSO). The effect of various DMSO solvent treatment methods on the performance of organic electrochemical transistors (OECTs) based on PEDOT:PSS is studied. The treatments include mixing PEDOT:PSS with DMSO before film deposition, exposing a deposited PEDOT:PSS film to a saturated DMSO vapor, and dipping a PEDOT:PSS film in a DMSO bath. Compared to dry PEDOT:PSS, operating in the OECT configuration causes a significant reduction of its conductivity for all treatments, due to the swelling of PEDOT:PSS by the direct contact of the conductive channel with the electrolyte. The dipping method gives rise to the highest OECT performance, reflected in the highest on/off ratio and transconductance. The improved conductivity and device performance after dipping arise from an enhanced charge carrier mobility due to enhanced structural order.
Progress in Nickel‐Coordinated Polymers as Intrinsically Conducting n‐Type Thermoelectric Materials
Authors: Menon Akanksha K. , Wolfe Rylan M. W. , Kommandur Sampath , Yee Shannon K. 
Published: February 2019

AbstractOrganic thermoelectrics have witnessed rapid development in the past decade for low temperature energy harvesting applications. While high‐performance p‐type polymers have been demonstrated, n‐type materials have lagged behind due to the limited number of stable n‐dopants and low doping efficiencies. Nickel‐coordination polymers are a promising class of n‐type polymers as they are conducting without extrinsic doping, thus overcoming a major challenge. However, advantages in thermoelectric properties are outweighed by a complicated synthesis and a poorly understood reaction mechanism that has resulted in a large variation in literature for the same material. This progress report provides a comprehensive and critical overview of syntheses and thermoelectric property optimization approaches for two coordination polymers, namely Ni‐ethenetetrathiolate (NiETT) and Ni‐tetrathiooxalate (NiTTO). In particular, material characterization and thin film fabrication techniques are discussed, and the importance of reporting statistically relevant thermoelectric properties is highlighted to ensure reproducibility among different groups. A short discussion on prototype devices based on NiETT is presented, and finally, directions for future development of these and other n‐type metal‐coordinated polymers are suggested.
Performance analysis and quantitative design of a flow‐guiding sieve tray by computational fluid dynamics
Authors: Zhao Hongkang , Li Qunsheng , Yu Gangqiang , Dai Chengna , Lei Zhigang 
Published: February 2019

AbstractAn evolution of the traditional sieve tray, the flow‐guiding sieve tray (FGST), has been utilized in many separation processes, especially for handling viscous systems. The objectives of this work are to optimize the design process of FGSTs and realize the full potential of their separation performance. A computation fluid dynamic (CFD) model that incorporated the modified interphase momentum transfer term was developed. Simulated measures of hydrodynamic performance, such as pressure drop, weeping, entrainment, and clear liquid height agree well with the experimental data, thus verifying the accuracy and reliability of the CFD model established in this work. Furthermore, based on the obtained hydrodynamic parameters, a quantitative model for designing flow‐guiding holes was established and validated by modifying an experimental FGST (diameter 476 mm) and reconstructing an industrial sieve‐tray tower (diameter 1,200 mm). The hydrodynamic parameters and quantitative model are of vital importance for better design and further modification of FGST.
Novel sulfonated multi‐walled carbon nanotubes filled chitosan composite membrane for fuel‐cell applications
Authors: Ahmed Saad , Ali Muhammad , Cai Yangben , Lu Yunhua , Ahmad Zaheer , Khannal Santosh , Xu Shiai 
Published: February 2019

ABSTRACTIn the present study, multi‐walled carbon nanotubes (MWCNTs) were sulfonated by 1,3‐propane sultone and distillation–precipitation polymerization, respectively, and then incorporated into chitosan (CS) to prepare CS/MWCNTs composite membranes for fuel cell applications. CS/MWCNTs membranes show better thermal and mechanical stability than pure CS membrane due to the strong electrostatic interaction between the SO3H groups of MWCNTs and the NH2groups of CS, which can restrict the mobility of CS chain. The sulfonated MWCNTs provide efficient proton hopping sites (SO3H, SO3−….3+HN), thereby resulting in the formation of continuous proton conducting channels. The composite membranes with 5 wt % of MWCNTs modified by two different ways show a proton conductivity of 0.026 and 0.025 S·cm−1, respectively. In conclusion, CS/MWCNTs membrane is a promising proton exchange membrane for fuel‐cell applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47603.
Jasmonic acid‐responsive AabHLH1 positively regulates artemisinin biosynthesis in Artemisia annua
Authors: Li Ling , Hao Xiaolong , Liu Hang , Wang Wei , Fu Xueqing , Ma Yanan , Shen Qian , Chen Minghui , Tang Kexuan 
Published: February 2019

AbstractArtemisia annua is the only natural source of the sesquiterpenoid artemisinin, which is widely used to treat malaria. The phytohormone jasmonic acid (JA) can significantly promote artemisinin biosynthesis in A. annua. AabHLH1 can bind and activate artemisinin biosynthetic genes, such as AaADS and AaCYP71AV1. In this study, we proved that AabHLH1 was responsive to MeJA treatment and highly expressed in glandular trichome‐enriched tissues, and that its expression profile was similar to that of AaADS. Yeast two‐hybrid assays showed that AabHLH1 interacted with all nine AaJAZ proteins in A. annua. Functional analysis with transgenic plants showed that several artemisinin biosynthetic genes were upregulated in AabHLH1‐OE transgenic A. annua lines and downregulated in AabHLH1‐EAR lines; furthermore, the artemisinin content was increased in the AabHLH1‐OE lines and decreased in the AabHLH1‐EAR lines. These results demonstrate that the JA‐induced AabHLH1 positively regulates artemisinin biosynthesis by regulating the biosynthetic genes, and thus provide new insight into the regulatory mechanism of JA‐induced artemisinin biosynthesis in A. annua.
Quantification of proteomic and metabolic burdens predicts growth retardation and overflow metabolism in recombinant Escherichia coli
Authors: Zeng Hong , Yang Aidong 
Published: February 2019

AbstractEscherichia coli has been the host organism most frequently investigated for efficient recombinant protein production. However, the production of a foreign protein in recombinant
E. coli often leads to growth deterioration and elevated secretion of acetic acid. Such observed phenomena have been widely linked with cell stress responses and metabolic burdens originated particularly from the increased energy demand. In this study, flux balance analysis and dynamic flux balance analysis were applied to investigate the observed growth physiology of recombinant
E. coli, incorporating the proteome allocation theory and an adjustable maintenance energy level (ATPM) to capture the proteomic and energetic burdens introduced by recombinant protein synthesis. Model predictions of biomass growth, substrate consumption, acetate excretion, and protein production with two different strains were in good agreement with the experimental data, indicating that the constraint on the available proteomic resource and the change in ATPM might be important contributors governing the growth physiology of recombinant strains. The modeling framework developed in this work, currently with several limitations to overcome, offers a starting point for the development of a practical, model‐based tool to guide metabolic engineering decisions for boosting recombinant protein production.
Streptomycin‐induced ribosome engineering complemented with fermentation optimization for enhanced production of 10‐membered enediynes tiancimycin‐A and tiancimycin‐D
Authors: Zhuang Zhoukang , Jiang Chengzhou , Zhang Fan , Huang Rong , Yi Liwei , Huang Yong , Yan Xiaohui , Duan Yanwen , Zhu Xiangcheng 
Published: February 2019

AbstractTiancimycins (TNMs) are a group of 10‐membered anthraquinone‐fused enediynes, newly discovered from Streptomyces sp. CB03234. Among them, TNM‐A and TNM‐D have exhibited excellent antitumor performances and could be exploited as very promising warheads for the development of anticancer antibody‐drug conjugates (ADCs). However, their low titers, especially TNM‐D, have severely limited following progress. Therefore, the streptomycin‐induced ribosome engineering was adopted in this work for strain improvement of CB03234, and a TNMs high producer S. sp. CB03234‐S with the K43N mutation at 30S ribosomal protein S12 was successfully screened out. Subsequent media optimization revealed the essential effects of iodide and copper ion on the production of TNMs, while the substitution of nitrogen source could evidently promote the accumulation of TNM‐D, and the ratio of produced TNM‐A and TNM‐D was responsive to the change of carbon and nitrogen ratio in the medium. Further amelioration of the pH control in scaled up 25 L fermentation increased the average titers of TNM‐A and TNM‐D up to 13.7 ± 0.3 and 19.2 ± 0.4 mg/L, respectively. The achieved over 45‐fold titer improvement of TNM‐A, and 109‐fold total titer improvement of TNM‐A and TNM‐D enabled the efficient purification of over 200 mg of each target molecule from 25 L fermentation. Our efforts have demonstrated a practical strategy for titer improvement of anthraquinone‐fused enediynes and set up a solid base for the pilot scale production and preclinical studies of TNMs to expedite the future development of anticancer ADC drugs.
Electron‐acceptor loadings affect chloroform dechlorination in a hydrogen‐based membrane biofilm reactor
Authors: Lai YenJung Sean , Ontiveros‐Valencia Aura , Coskun Tamer , Zhou Chen , Rittmann Bruce E. 
Published: February 2019

AbstractChloroform (CF) can undergo reductive dechlorination to dichloromethane, chloromethane, and methane. However, competition for hydrogen (H2), the electron‐donor substrate, may cause poor dechlorination when multiple electron acceptors are present. Common acceptors in anaerobic environments are nitrate (NO3−), sulfate (SO42−), and bicarbonate (HCO3−). We evaluated CF dechlorination in the presence of HCO3− at 1.56 e− Eq/m2‐day, then NO3− at 0.04–0.15 e− Eq/m2‐day, and finally NO3− (0.04 e− Eq/m2‐day) along with SO42− at 0.33 e− Eq/m2‐day in an H2‐based membrane biofilm reactor (MBfR). When the biofilm was initiated with CF‐dechlorination conditions (no NO3− or SO42−), it yielded a CF flux of 0.14 e− Eq/m2‐day and acetate production via homoacetogenesis up to 0.26 e− eq/m2‐day. Subsequent addition of NO3− at 0.05 e− Eq/m2‐day maintained full CF dechlorination and homoacetogenesis, but NO3− input at 0.15 e− Eq/m2‐day caused CF to remain in the reactor's effluent and led to negligible acetate production. The addition of SO42− did not affect CF reduction, but SO42− reduction significantly altered the microbial community by introducing sulfate‐reducing Desulfovibrio and more sulfur‐oxidizing Arcobacter. Dechloromonas appeared to carry out CF dechlorination and denitrification, whereas Acetobacterium (homoacetogen) may have been involved with hydrolytic dechlorination. Modifications to the electron acceptors fed to the MBfR caused the microbial community to undergo changes in structure that reflected changes in the removal fluxes.
Enhancing the functionality of a microscale bioreactor system as an industrial process development tool for mammalian perfusion culture
Authors: Sewell David J , Turner Richard , Field Ray , Holmes William , Pradhan Rahul , Spencer Christopher , Oliver Stephen G , Slater Nigel KH , Dikicioglu Duygu 
Published: February 2019

AbstractWithout a scale‐down model for perfusion, high resource demand makes cell line screening or process development challenging, therefore, potentially successful cell lines or perfusion processes are unrealized and their ability untapped. We present here the refunctioning of a high‐capacity microscale system that is typically used in fed‐batch process development to allow perfusion operation utilizing in situ gravity settling and automated sampling. In this low resource setting, which involved routine perturbations in mixing, pH and dissolved oxygen concentrations, the specific productivity and the maximum cell concentration were higher than 3.0 × 106 mg/cell/day and 7 × 10
7 cells/ml, respectively, across replicate microscale perfusion runs conducted at one vessel volume exchange per day. A comparative analysis was conducted at bench scale with vessels operated in perfusion mode utilizing a cell retention device. Neither specific productivity nor product quality indicated by product aggregation (6%) was significantly different across scales 19 days after inoculation, thus demonstrating this setup to be a suitable and reliable platform for evaluating the performance of cell lines and the effect of process parameters, relevant to perfusion mode of culturing.
Deregulation of methanol metabolism reverts transcriptional limitations of recombinant Pichia pastoris (Komagataella spp) with multiple expression cassettes under control of the AOX1 promoter
Authors: Cámara Elena , Monforte Sergi , Albiol Joan , Ferrer Pau 
Published: February 2019

AbstractThe methanol‐regulated alcohol oxidase promoter (PAOX1) of Pichia pastoris (syn. Komagataella spp. ) is one of the strongest promoters for heterologous gene expression. Although increasing the gene dosage is a common strategy to improve recombinant protein productivities, P. pastoris strains harboring more than two copies of a Rhizopus oryzae lipase gene (ROL) have previously shown a decrease in cell growth, lipase production, and substrate consumption, as well as a significant transcriptional downregulation of methanol metabolism. This pointed to a potential titration effect of key transcriptional factors methanol expression regulator 1 (Mxr1) and methanol‐induced transcription factor (Mit1) regulating methanol metabolism caused by the insertion of multiple expression vectors. To prove this hypothesis, a set of strains carrying one and four copies of ROL (1C and 4C, respectively) were engineered to coexpress one or two copies of MXR1*, coding for an Mxr1 variant insensitive to repression by 14‐3‐3 regulatory proteins, or one copy of MIT1. Small‐scale cultures revealed that growth, Rol productivity, and methanol consumption were improved in the 4C‐MXR1* and 4C‐MIT1, strains growing on methanol as a sole carbon source, whereas only a slight increase in productivity was observed for re‐engineered 1C strains. We further verified the improved performance of these strains in glycerol‐/methanol‐limited chemostat cultures.
Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks
Authors: Habicher Tobias , John Arian , Scholl Niklas , Daub Andreas , Klein Tobias , Philip Priya , Büchs Jochen 
Published: February 2019

AbstractTo overcome catabolite repression, industrial fermentation processes are usually operated in substrate‐limited fed‐batch mode. Therefore, the implementation of such an operating mode at small scale is crucial to maintain comparable process conditions. In this study, Bacillus licheniformis, a well‐known producer of proteases, was cultivated with carbon (glucose)‐ and nitrogen (ammonium)‐limited fed‐batch conditions using the previously introduced membrane‐based fed‐batch shake flasks. A repression of protease production by glucose and ammonium was thus avoided and yields increased 1.5‐ and 2.1‐fold relative to batch, respectively. An elevated feeding rate of glucose caused depletion of ammonium, which was recognizable within the oxygen transfer rate (OTR) signal measured with the Respiration Activity MOnitoring System (RAMOS). Ammonium limitation was prevented by feeding ammonium simultaneously with glucose. The OTR signal clearly indicated the initiation of the fed‐batch phase and gave direct feedback on the nutrient release kinetics. Increased feeding rates of glucose and ammonium led to an elevated protease activity without affecting the protease yield (YP/Glu). In addition to YP/Glu, protease yields were determined based on the metabolized amount of oxygen . The results showed that the protease production correlated with the amount of consumed glucose as well as with the amount of consumed oxygen. The membrane‐based fed‐batch shake flask in combination with the RAMOS device is a powerful combination to investigate the effect of substrate‐limited fed‐batch conditions.
Chemical, Antioxidant, and Antimicrobial Evaluation of Essential Oils and an Anatomical Study of the Aerial Parts from Baccharis Species (Asteraceae)
Authors: Zuccolotto Tatiana , Bressan Jaqueline , Lourenço Allan V. F. , Bruginski Estevan , Veiga Andressa , Marinho Jane V. N. , Raeski Paola A. , Heiden Gustavo , Salvador Marcos J. , Murakami Fabio S. , Budel Jane M. , Campos Francinete R. 
Published: February 2019

AbstractThe aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC/MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORACFL) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only seven (β‐caryophyllene, γ‐muurolene, bicyclogermacrene, β‐germacrene, spathulenol, τ‐muurolol, and α‐cadinol) were common in the three specimens studied. Of these, γ‐muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORACFL (>500.0 μmol TE g−1) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.
TAVR for aortic valve regurgitation: Ready for a randomized trial?
Authors: Belardi Jorge , Lamelas Pablo 
Published: February 2019

Key Points

Transcatheter aortic valve replacement has been used successfully to treat native aortic valve regurgitation.
Current observational evidence shows promising results in terms of procedural success while outcome data are difficult to interpret given the observational nature of the evidence.
We are ready for a randomized trial, which will be very challenging to run.
Fractional flow reserve from intravascular ultrasound imaging: Computational fluid dynamics to the rescue?
Authors: Kern Morton J. , Seto Arnold H. 
Published: February 2019

Key Points

IVUS measurements of luminal area have only modest correlations to FFR.
This study used IVUS 3D anatomical data in a computational fluid dynamic model to estimate FFR with a reasonable degree of accuracy.
Further studies are needed to refine the models to make them more accurate and practical for routine use.
Techno‐economic feasibility of phosphorus recovery as a coproduct from corn wet milling plants
Authors: Juneja Ankita , Sharma Navneet , Cusick Roland , Singh Vijay 
Published: February 2019

AbstractBackground and objectivesWet milling (WM) plants contribute to both point source and nonpoint source phosphorus (P) pollution by concentrating P in the coproduct corn gluten feed (CGF), the majority of which is undigested when consumed by ruminants, leading to manure management concerns. Phosphorus runoff from the manure consequently causes eutrophication in the water bodies downstream. This study investigates the economic feasibility of recovering the phosphorus at the front end from light steepwater to reduce P in CGF.FindingsThe amount of phosphorus in CGF was observed to reduce from 11.94 mg/g (db) to 2.44 mg/g (db), with phosphorus removal in the recovery unit calibrated with laboratory experiments. Direct fixed capital cost of $6.9 MM was estimated for the phosphorus recovery unit in an existing WM plant.ConclusionsWith a phosphorus recovery rate of 0.17 MT/hr, the operating cost of P recovery at the front end was estimated to be $1.23/kg‐P removed.Significance and noveltyRamifications of excess phosphorus in CGF on environment are an important understudied area. This study provided economic and technical feasibility of phosphorus recovery from CGF in WM industry, consequently producing a new coproduct and reducing the environmental burden.
Model‐less digital workflow for the replication of an existing complete fixed implant‐supported prosthesis using an intraoral scanner
Authors: Markarian Roberto A. , Feitosa Filho Marco , Vasconcelos Ednaria 
Published: February 2019

Key Clinical MessageThe use of an intraoral scanner was efficient to produce a full‐contour zirconia CAFIP, with improved esthetics when compared to the original prosthesis.
SnS2 Nanosheets/H‐TiO2 Nanotube Arrays as a Type II Heterojunctioned Photoanode for Photoelectrochemical Water Splitting
Authors: Lin Jianfei , Liu Yong , Liu Yongping , Huang Chen , Liu Wenhui , Mi Xihong , Fan Dayong , Fan Fengtao , Lu Huidan , Chen Xiaobo 
Published: February 2019

AbstractImproving the separation efficiency of photogenerated electron–hole pairs and the conductivity of electrons to photoanode substrates are critical to achieve high‐performance photoelectrochemical (PEC) water splitting. Here, a SnS2/H‐TiO2/Ti heterojunction photoanode was fabricated with SnS2 nanosheets vertically grown on hydrogen‐treated TiO2 (H‐TiO2) nanotube arrays on a Ti substrate. It showed a significantly enhanced photocurrent of 4.0 mA cm−2 at 1.4 V (vs. reversible hydrogen electrode) under AM 1.5 G illumination, 70 times higher than that of SnS2/TiO2/Ti. Kelvin probe force microscopy measurements indicated that photogenerated electrons could be easily transported through the SnS2/H‐TiO2 interface but not through the SnS2/TiO2 interface. Through hydrogen treatment, defects were created in H‐TiO2 nanotubes to convert type I junctions to type II with SnS2 nanosheets. As a result, a high efficiency of electron–hole separation at the SnS2/H‐TiO2 interface and a high electron conductivity in H‐TiO2 nanotubes were achieved and improved PEC performance. These findings show an effective route towards high‐performance photoelectrodes for water splitting.