bluuebunny/crossref_metadata_2025_split huggingface dataset:
Charge–Ferroelectric Transition in Ultrathin Na0.5Bi4.5Ti4O15 Flakes Probed via a Dual‐Gated Full van der Waals Transistor
Authors: Liu Xiaochi , Zhou Xuefan , Pan Yuchuan , Yang Junqiang , Xiang Haiyan , Yuan Yahua , Liu Song , Luo Hang , Zhang Dou , Sun Jian 
Published: November 2020

AbstractFerroelectric field‐effect transistors (FeFETs) have recently attracted enormous attention owing to their applications in nonvolatile memories and low‐power logic electronics. However, the current mainstream thin‐film‐based ferroelectrics lack good compatibility with the emergent 2D van der Waals (vdW) heterostructures. In this work, the synthesis of thin ferroelectric Na0.5Bi4.5Ti4O15 (NBIT) flakes by a molten‐salt method is reported. With a dry‐transferred NBIT flake serving as the top‐gate dielectric, dual‐gate molybdenum disulfide (MoS2) FeFETs are fabricated in a full vdW stacking structure. Barrier‐free graphene contacts allow the investigation of intrinsic carrier transport of MoS2 governed by lattice scattering. Thanks to the high dielectric constant of ≈94 in NBIT, a metal to insulator transition with a high electron concentration of 3.0 × 1013 cm−2 is achieved in MoS2 under top‐gate modulation. The electron field‐effect mobility as high as 182 cm2 V−1 s−1 at 88 K is obtained. The as‐fabricated MoS2 FeFET exhibits clockwise hysteresis transfer curves that originate from charge trapping/release with either top‐gate or back‐gate modulation. Interestingly, hysteresis behavior can be controlled from clockwise to counterclockwise using dual‐gate. A multifunctional device utilizing this unique property of NBIT, which is switchable electrostatically between short‐term memory and nonvolatile ferroelectric memory, is envisaged.
Nanomechanical Gas Sensing with Laser Treated 2D Nanomaterials
Authors: Mistry Kissan , Ibrahim Khaled H. , Novodchuk Inna , Ngo Hyunh Thien , Imamura Gaku , Sanderson Joseph , Yavuz Mustafa , Yoshikawa Genki , Musselman Kevin P. 
Published: November 2020

Abstract2D nanomaterials such as graphene oxide (GO), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) are viable candidates for use in chemical gas sensors due to their large specific surface area available for analyte adsorption. In this work, these 2D materials are treated with a femtosecond laser process to intentionally introduce defects, dopants, and functional groups to the material for improved gas adsorption properties. The materials are coated onto a nanomechanical membrane‐type surface stress sensor (MSS) to evaluate their sensing capability toward a select group of volatile organic compounds. By utilizing the MSS platform, the approach avoids the need for 2D materials with conductive properties typically required in chemoresistive sensors. The results show that a longer laser treatment time for graphene oxide increases the sensor response, which is attributed to an increase in defects and oxygen functional groups. Doping of graphene oxide with boron nitride improves sensor response, likely due to the introduction of pyrrolic nitrogen groups with high chemical activity. Additionally, the graphene oxides demonstrate partial selectivity toward the detection of toluene, attributable to π–π interactions. MoS2 and WS2 nanoflakes also show enhanced sensor response attributed to the formation of apical/bridging sulfur bonds with high catalytic activity.
Reduction of Electron‐Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
Authors: Larionova Natalia A. , Ondozabal Jun Miyatake , Cambeiro Xacobe C. 
Published: November 2020

AbstractDirect hydrogen atom transfer from a photoredox‐generated Hantzsch ester radical cation to electron‐deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT‐driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron‐donating or electron‐withdrawing substituents in the aromatic ring and with good functional group compatibility.magnified image
Metal‐Free, DBU‐Mediated, Microwave‐Assisted Synthesis of Benzo[c]xanthones by Tandem Reactions of Alkynyl‐1,3‐diketones
Authors: Liang Yi‐En , D. Barve Balaji , Kuo Yao‐Haur , Fang Hsu‐Wei , Kuo Ting‐Shen , Li Wen‐Tai 
Published: November 2020

AbstractA base‐mediated, green, microwave‐assisted efficient preparation of a diverse benzoxanthone library from variety of readily accessible γ‐alkynyl 1,3‐diketones is reported. The synthesis is based on tandem reactions involving intramolecular cyclization, propargyl‐allenyl isomerization, and electrocyclization in one pot. Some of the benzoxanthones are also synthesized by the one‐pot reaction of 1,3‐diketone and alkynyl bromide under basic heating conditions. This transformation also results in the construction of one new C−C bond and one new C−O bond.magnified image
Synthesis of Seleno Oxindoles via Electrochemical Cyclization of N‐arylacrylamides with Diorganyl Diselenides
Authors: Wang Xin‐Yu , Zhong Yuan‐Fang , Mo Zu‐Yu , Wu Shi‐Hong , Xu Yan‐Li , Tang Hai‐Tao , Pan Ying‐Ming 
Published: November 2020

AbstractThe tandem cyclization of acrylamide with diselenides facilitated by electrochemical oxidation was successfully developed. This strategy provided an environmentally friendly method for the construction of C−Se bond. A series of seleno oxindoles with pharmacological activity were obtained by using this well‐designed tandem cyclization strategy. The in vitro antitumor activity of the compounds was also screened through MTT assay. Results showed that the seleno oxindoles exhibited better antitumor activity than other oxindole derivatives.magnified image
Full donor chimerism after allogeneic hematopoietic stem cells transplant for myelofibrosis: The role of the conditioning regimen
Authors: Chiusolo Patrizia , Bregante Stefania , Giammarco Sabrina , Lamparelli Teresa , Casarino Lucia , Dominietto Alida , Raiola Anna Maria , Metafuni Elisabetta , Di Grazia Carmen , Gualandi Francesca , Sora Federica , Laurenti Luca , Sica Simona , Barosi Gianni , Guolo Fabio , Rossi Monica , Rossi Elena , Vannucchi Alessandro , Signori Alessio , De Stefano Valerio , Bacigalupo Andrea , Angelucci Emanuele 
Published: November 2020

AbstractThe aim of this retrospective study was to assess the rate of full donor chimerism (F‐DC) in patients with myelofibrosis, prepared for an allogeneic stem cell transplant, with one or two alkylating agents. We analyzed 120 patients with myelofibrosis, for whom chimerism data were available on day +30. There were two groups: 42 patients were conditioned with one alkylating agent (ONE‐ALK), either thiotepa or busulfan or melphalan, in combination with fludarabine, whereas 78 patients were prepared with two alkylating agents, thiotepa busulfan and fludarabine (TBF). Patients receiving TBF were older (57 vs 52 years), were less frequently splenectomized pre‐HSCT (31% vs 59%), had more frequently intermediate‐2/high DIPSS scores (90% vs 74%), were grafted more frequently from alternative donors (83% vs 33%) and received more frequently ruxolitinib pre‐HSCT (26% vs 7%). The proportion of patients with F‐DC on day +30, in the TBF vs the ONE‐ALK group, was respectively 87% vs 45% (P < .001). The 5‐year cumulative incidence of relapse was 9% in the TBF group, vs 43% for the ONE‐ALK group (P < .001). The 5‐year actuarial disease‐free survival was 63% for TBF and 38% for the ONE‐ALK group (P = .004). In conclusion, early full donor chimerism is a prerequisite for long term control of disease in patients with myelofibrosis, undergoing an allogeneic HSCT. The combination of two alkylating agents in the conditioning regimen, provides a higher chance of achieving full donor chimerism on day+30, and thus a higher chance of long term disease free survival.
Trifluoroethanol‐mediated Decarboxylative Addition Reactions of β‐Ketoacids with Diverse Electrophiles
Authors: Guan Ren‐You , Hsu Chan‐Wei , Han Jeng‐Liang 
Published: November 2020

AbstractAn efficient decarboxylative addition reaction of β‐ketoacids with miscellaneous electrophiles in 2,2,2‐trifluoroethanol (TFE) is reported. The reaction proceeds smoothly without any base and metal catalysts, affording a broad range of diarylmethanes, β‐hydroxy ketones and 3,3‐disubstituted oxindoles with moderate to excellent yields under essentially neutral conditions.
Pincer Ligand Enhanced Rhodium‐Catalyzed Carbonylation of Formaldehyde: Direct Ethylene Glycol Production
Authors: Meyer Tim , Konrath Robert , Kamer Paul C. J. , Wu Xiao‐Feng 
Published: November 2020

AbstractFormaldehyde is one of the most important bulk chemicals and is produced on a million tone scale (52 million tons in 2017).[1] Since the middle of the last century, the challenge has remained to produce the valuable ethylene glycol (EG) directly from the C1 building block formaldehyde in a single step. In the systems reported so far, the reaction conditions were very harsh, often with pressures above 400 bar. However, under milder conditions, the selectivity was on the side of glycol aldehyde (GA) and the hydrogenation product methanol. Only traces of EG could be generated in the presence of a Rh catalyst. Herein, we describe a new Rh catalyst system with pincer ligand, which allows the direct one pot synthesis of EG from easy to handle paraformaldehyde (PFA) at remarkable mild conditions (70 bar, 100 °C) and overcomes the aforementioned limitations with yield up to 40%.
Utility of a prediction model for delirium in intensive care unit patients (PRE‐DELIRIC) in mechanically ventilated patients with sepsis
Authors: Miyamoto Kyohei , Nakashima Tsuyoshi , Shima Nozomu , Kato Seiya , Kawazoe Yu , Morimoto Takeshi , Ohta Yoshinori , Yamamura Hitoshi ,   DESIRE Trial Investigators
Published: November 2020

AimDelirium frequently develops in patients with sepsis during their intensive care unit (ICU) stay, which is associated with increased morbidity and mortality. A prediction model for delirium in patients in ICU, PRE‐DELIRIC, has been utilized in overall ICU patients, but its utility is uncertain among patients with sepsis. This study aims to examine the utility of PRE‐DELIRIC to predict delirium in mechanically ventilated patients with sepsis.MethodsThis is a post hoc analysis of a randomized clinical trial in eight Japanese ICUs, which aimed to evaluate the sedative strategy with/without dexmedetomidine in adult mechanically ventilated patients with sepsis. The Confusion Assessment Method for the ICU was used every day to assess for delirium throughout their ICU stay. We excluded patients who were delirious on the first day of ICU, those who were under sustained coma throughout their ICU stay, and those who stayed in the ICU less than 24 h. The discriminative ability of PRE‐DELIRIC was evaluated by measuring the area under the receiver operating characteristic curve (AUROC).ResultsOf the 201 patients enrolled in the trial, we analyzed 158 patients. The mean age was 69.4 ± 14.0 years, and 99 patients (63%) were men. Delirium occurred at least once during the ICU stay of 63 patients (40%). The AUROC of PRE‐DELIRIC was 0.60 (95% confidence interval, 0.50–0.69). Subgroup analyses indicated that PRE‐DELIRIC was useful in those with Sequential Organ Failure Assessment score >8 with AUROC of 0.65 (95% confidence interval, 0.51–0.77).ConclusionsThe PRE‐DELIRIC model could not predict delirium in mechanically ventilated patients with sepsis.
Umpolung of B−H Bonds by Metal–Ligand Cooperation with Cyclopentadienone Iridium Complexes
Authors: Higashi Takuya , Kusumoto Shuhei , Nozaki Kyoko 
Published: November 2020

AbstractIn contrast to conventional metal–ligand cooperative cleavage of a B−H bond, which provides a B cation on the ligand and an H anion on the metal, we report herein the umpolung of B−H bonds by novel cyclopentadienone iridium complexes. The B−H bonds of 4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane (HBpin) and 1,8‐naphthalenediaminatoborane (HBdan) were cleaved to give a B anion on the metal and an H cation on the phenolic oxygen atom of the ligand. Mechanistic investigation by DFT calculations revealed that the alkoxycarbonyl‐substituted cyclopentadienone ligand facilitated deprotonation from Ir−H after oxidative addition of the B−H bond to give the umpolung product. The generated boryliridium complex was found to undergo borylation of an allyl halide in the presence of base, thus showing the nucleophilic nature of the boron atom.
Solvatochromic Photoluminescent Effects in All‐Inorganic Manganese(II)‐Based Perovskites by Highly Selective Solvent‐Induced Crystal‐to‐Crystal Phase Transformations
Authors: Xiao Hui , Dang Peipei , Yun Xiaohan , Li Guogang , Wei Yi , Wei Yi , Xiao Xiao , Zhao Yajie , Molokeev Maxim S. , Cheng Ziyong , Lin Jun 
Published: November 2020

AbstractThe development of lead‐free perovskite photoelectric materials has been an extensive focus in the recent years. Herein, a novel one‐dimensional (1D) lead‐free CsMnCl3(H2O)2 single crystal is reported with solvatochromic photoluminescence properties. Interestingly, after contact with N,N‐dimethylacetamide (DMAC) or N,N‐dimethylformamide (DMF), the crystal structure can transform from 1D CsMnCl3(H2O)2 to 0D Cs3MnCl5 and finally transform into 0D Cs2MnCl4(H2O)2. The solvent‐induced crystal‐to‐crystal phase transformations are accompanied by loss and regaining of water of crystallization, leading to the change of the coordination number of Mn2+. Correspondingly, the luminescence changes from red to bright green and finally back to red emission. By fabricating a test‐paper containing CsMnCl3(H2O)2, DMAC and DMF can be detected quickly with a response time of less than one minute. These results can expand potential applications for low‐dimensional lead‐free perovskites.
A Visible‐Light‐Regulated Chloride Transport Channel Inspired by Rhodopsin
Authors: Quan Jiaxin , Zhu Fei , Dhinakaran Manivannan Kalavathi , Yang Yingying , Johnson Robert P. , Li Haibing 
Published: November 2020

AbstractInspired by the light‐regulating capabilities of naturally occurring rhodopsin, we have constructed a visible‐light‐regulated Cl−‐transport membrane channel based on a supramolecular host–guest interaction. A natural retinal chromophore, capable of a visible‐light response, is used as the guest and grafted into the artificial channel. Upon introduction of an ethyl‐urea‐derived pillar[6]arene (Urea‐P6) host, threading or de‐threading of the retinal and selective bonding of Cl− can be utilized to regulate ion transport. Based on the visible‐light responsiveness of the host–guest interaction, Cl− transport can be regulated by visible light between ON and OFF states. Visible‐light‐regulated Cl− transport as a chemical model permits to understand comparable biological ion‐selective transport behaviors. Furthermore, this result also supplies a smart visible‐light‐responsive Cl− transporter, which may have applications in natural photoelectric conversion and photo‐controlled delivery systems.
Thermal desorption and pyrolysis direct analysis in real time mass spectrometry of Nafion membrane
Authors: Yamaguchi Makoto 
Published: November 2020

AbstractPerfluorosulfonic acid ionomer membranes have been widely used as proton conducting membranes in various electrochemical processes such as polymer electrolyte fuel cells and water electrolysis. While their thermal stability has been studied by thermogravimetry and analysis of low molecular weight products, their decomposition mechanism is little understood. In this study a newly developed methodology of thermal desorption and pyrolysis in combination with direct analysis in real time mass spectrometry is applied for Nafion membrane. An ambient ionization source and a high‐resolution time‐of‐flight mass spectrometer enabled unambiguous assignment of gaseous products. Thermal decomposition is initiated by side chain detachment above 350°C, which leaves carbonyls on the main chain at the locations of the side chains. Perfluoroalkanes are released above 400°C by main chain scission and their further decomposition products dominate above 500 °C. DFT calculation of reaction energies and barrier heights of model compounds support proposed decomposition reactions.
Novel approach to recover copper ions using poly(ethylene imine) based layer‐by‐layer coatings on icosane particles
Authors: Seitz Steffen , Tsujimoto Masaya , Chanthaset Nalinthip , Yoshida Hiroaki , Ajiro Hiroharu 
Published: November 2020

AbstractThe low‐density materials are developed for the wastewater treatment, the particles could be easily recovered when floating upon water surface and be recycling of a large fraction. Simultaneously, we selected the low melting point of material, which is possible to separate easily the compounds after usage. We chose icosane as a core material with layer‐by‐layer (LbL) films as an adsorbent for wastewater containing copper ions. The icosane particles were coated by poly(ethylene imine) (PEI) as positively charged layer and either poly(acrylic acid) (PAA) or poly(styrene sulfonate) as counterpart. Glutaraldehyde was introduced as a crosslinking agent to create multilayered shells with various active sites as scavenger. The copper adsorption abilities of PEI‐PAA‐coated particles were examined by inductively coupled plasma mass spectrometry. Interestingly, the adsorption amount of copper ions on PEI/PAA coated particles (16.5 mg) was optimized at 82 μg/L after 5 min of elution time, which shows a good potential of our material in the field of application. With the facile and consistent separation of the core and LbL coating, the thermal properties were revealed a stable melting temperature at around 38°C.
Mild sulfonated polyether ketone ether ketone ketone incorporated polysulfone membranes for microbial fuel cell application
Authors: Azhar Masaud , Jaafar Juhana , Aziz Madzlan , Umar Yunusa , Jafar Mazumder Mohammad A. , Nazal Mazen K. 
Published: November 2020

AbstractTo address the impediments of low power generation of Nafion, which is the main hurdle in the commercialization of microbial fuel cells (MFC), the current study focuses on developing a new PEM for MFC from mild sulfonation of PEKEKK with relatively improved physiochemical properties. In this study, mild post sulfonation of a polyether ketone ether ketone ketone (PEKEKK) has been successfully achieved using 98% H2SO4 at 90°C under reflux. 5%–30% (wt%) of sulfonated PEKEKK (SPEKEKK) loaded polysulfone (PSU) composite membranes were fabricated via a solution casting method. Ingeminating evidence of the sulfonation and structure of sulfonated polymer was proved by 1H NMR peaks integration data and FTIR, respectively. The addition of SPEKEKK to PSU showed significant improvement in conductivity owing to the availability of more protonated sites (SO3H) and water mediated pathways for the conduction of protons. The composite membrane containing 30 wt% SPEKEKK exhibits the highest conductivity of 0.12 S/cm at 90°C. The water uptakes and swelling ratio of the composite membranes are all higher than that of the pristine PSU membrane and show an increasing trend with increasing SPEKEKK content, thus validating the availability of water domains. Meanwhile, the lowest initial decomposition temperatures assigned to sulfonic acid groups and main chain degradation of the polysulfone/polyether ketone ether ketone ketone (PSU/SPEKEKK) composite membranes occurred at ~300°C and ~500°C respectively, which reflects an excellent thermal stability property. The experimental results indicate that the PSU/SPEKEKK membrane has the potential to greatly enhance the efficiency of MFCs.
Preparation of stiffer ternary blends of polypropylene/polyamide 6/biodegradable polymers with improved interfacial adhesion
Authors: Amantes Bruno de P. , de Oliveira Renato Jonas B. , Marques Maria de Fátima V. 
Published: November 2020

AbstractBlends of polypropylene (PP), polyamide 6 (PA6), and biodegradable polymers (BPs) such as poly(D,L‐lactic acid) (PDLLA), poly(lactic acid‐co‐ε‐caprolactone) (poly[LA‐co‐ε‐CL]) and poly(ε‐caprolactone) (PCL) were prepared using a twin‐screw mini‐extruder. The composition of the blend PP/PA6 was fixed at a mass proportion of 70/30, and the compatibilized blends contain 5 wt% of each BP. The morphology observed through scanning electronic microscopy, the dynamic mechanical thermal properties (DMTA), and the biodegradation test after composting and performing optical microscopy (OM) of the blends were investigated. The blend PP/PA6 compatibilized with polypropylene grafted with maleic anhydride (PPMA) was also obtained and used as a reference. The results showed that the PP/PA6/PPMA revealed a more homogeneous morphology and resulted in higher modulus; nevertheless, the sample obtained with the lower molar mass PDLLA as an alternative for PPMA showed a storage modulus behavior close to the reference material. Poly(LA‐co‐ε‐CL) and PCL also showed changes in the morphology of the PA6 dispersed phase. Positive results were observed in the biodegradation test examined by OM for all samples containing BPs. The novelty of this work was to employ BPs as compatibilizing agents of the blends comprising PP/PA6, producing ternary blends with superior mechanical properties due to the better dispersion of the phases.
Monitoring Indo‐Pacific humpback dolphin occurrences in a highly urbanized estuary for informing conservation and management
Authors: Fang Liang , Lin Wenzhi , Guo Lang , Cai Huayang , Pine Matthew K. , Wu Yuping 
Published: November 2020

Abstract

The estuaries within the Pearl River Delta are sites for large‐scale urban development and offshore construction. These projects have conservation stakeholders calling for more protection for the Indo‐Pacific humpback dolphins whose habitat overlaps with current and proposed construction sites.
Efforts to improve impact assessments are hindered by the lack of baseline data and comprehensive understanding of how often the dolphins are present in areas near or within locations targeted for further development. The Modaomen Estuary within the Pearl River Delta is a good example of this, with little consideration for the dolphins as no data on their diurnal and seasonal occurrences within the estuary exist.
A passive acoustic monitoring system was deployed over a calendar year from October 2016 to September 2017 to monitor the presence of humpback dolphins in the Modaomen Estuary.
Results indicated that the estuary is an important area for humpback dolphins, with regular diel rhythms and seasonality in detection rates. For example, higher detections were seen during the wet season than during the dry season. However, there was no significant difference in detection rates between the flood and ebb tides, or between high and low tidal phases.
Since the Modaomen Estuary is targeted for further development in the near future, these data provide the rationale for resource management and consent processes to consider potential impacts on the dolphins, as well as to aid marine spatial planning and conservation measures.