bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low‐Dimensional Perovskites: From Synthesis to Stability in Perovskite Solar Cells
Authors: Yusoff Abd. Rashid bin Mohd. , Nazeeruddin Mohammad Khaja 
Published: December 2017

AbstractPerovskite solar cells have been heralded as one of the most promising emerging technologies in 2016 because of the very high power conversion efficiency of 22% and the low cost of generating electricity compared to even fossil fuels. These are formed with various dimensionalities and can be fully manipulated once their bulk structure is reduced to a low‐dimensional structure. Despite being one of the most attractive materials to date, their instability significantly influences device performance and subsequently prevents the timely commercialization of perovskite solar cell technology. In this review, the recent advances in the synthesis of stable low‐dimensional metal‐halide perovskites are highlighted.
A Dipleiadiene‐Embedded Aromatic Saddle Consisting of 86 Carbon Atoms
Authors: Pun Sai Ho , Chan Chi Kit , Luo Jiye , Liu Zhifeng , Miao Qian 
Published: December 2017

AbstractThis study presents a new type of negatively curved nanographene (C86H32) that contains an unprecedented pattern of heptagons. A tert‐butylated derivative of C86H32 was successfully synthesized using tetrabenzodipleiadiene as a key building block. This synthesis involved a ring expansion reaction as a key step to form the seven‐membered rings in the framework of tetrabenzodipleiadiene. The single‐crystal structure reveals a saddle‐shaped molecule with a highly bent naphthalene moiety at the center of the polycyclic backbone. As found from the DFT calculations, this aromatic saddle is flexible at room temperature and has a saddle‐shaped geometry as the dominant conformation. The DFT calculations along with experimental results show that the attachment of t‐butyl groups to the central tetrabenzodipleiadiene moiety of nanographene C86H32 can stabilize the saddle conformation and make this nanographene less flexible.
Intracellular Delivery of Native Proteins Facilitated by Cell‐Penetrating Poly(disulfide)s
Authors: Qian Linghui , Fu Jiaqi , Yuan Peiyan , Du Shubo , Huang Wei , Li Lin , Yao Shao Q. 
Published: December 2017

AbstractIntracellular delivery of therapeutic proteins is highly challenging and in most cases requires chemical or genetic modifications. Herein, two complementary approaches for endocytosis‐independent delivery of proteins to live mammalian cells are reported. By using either a “glycan” tag naturally derived from glycosylated proteins or a “traceless” tag that could reversibly label native lysines on non‐glycosylated proteins, followed by bioorthogonal conjugation with cell‐penetrating poly(disulfide)s (CPDs), we achieved intracellular delivery of proteins (including antibodies and enzymes) which, upon spontaneous degradation of CPDs, led to successful release of their “native” functional forms with immediate bioavailability.
Interface engineering for the improvement of mechanical and thermal properties of covalent functionalized graphene/epoxy composites
Authors: Chhetri Suman , Adak Nitai Chandra , Samanta Pranab , Mallisetty Phani Kumar , Murmu Naresh Chandra , Kuila Tapas 
Published: December 2017

ABSTRACTFunctionalized reduced graphene oxide (GO)/epoxy composites are fabricated through solution mixing. GO is functionalized using 3‐amino‐1,2,4‐triazole (TZ) in presence of potassium hydroxide (KOH). KOH is expected to serve dual role as catalyst for nucleophilic addition reaction between GO and TZ, and also as reducing agent. The grafting of TZ moiety on GO is confirmed by Fourier transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The prepared composites show remarkable improvement in mechanical and thermal stability. The fracture toughness of the composites (critical stress intensity factor, KIC) achieved from single edge notched bending testing is improved by ∼111% against pure epoxy at 0.1 wt % loading of TZ functionalized GO. Further, the tensile strength and Young's modulus are improved by ∼30.5% and 35%, respectively. Thermal stability of the composites as investigated by thermogravimetric analysis showed 29 °C rise in onset degradation temperature for 0.1 wt % TZ functionalized GO incorporated composite. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46124.
Optical sensor based on fluorescent PMMA/PFO electrospun nanofibers for monitoring volatile organic compounds
Authors: Terra Idelma A. A. , Sanfelice Rafaela C. , Valente Gustavo T. , Correa Daniel S. 
Published: December 2017

ABSTRACTThe development of polymeric materials with superior electrical and/or optical properties is highly demanded for designing optical gas sensors, where conjugated polymers play an important role due to their π‐electron conjugation. However, usually the low processability and high cost of these materials hinder technological applications. Here we report on a simple route to develop highly fluorescent electrospun nanofibers of poly(methyl methacrylate) (PMMA) containing low contents of polyfluorene (PFO). The PMMA_PFO nanofibers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, while the luminescence properties changes were evaluated by exposing the PMMA_PFO nanofibers to distinct volatile organic compounds (VOCs) including ethanol, toluene, tetrahydrofuran, acetone, dichloromethane, and chloroform. The changes in luminescence properties, specifically fluorescence quenching, of PMMA_PFO nanofibers were analyzed in terms of conformational changes from glassy‐phase to β‐phase of PFO when the nanofibers were exposed to the VOCs. The developed nanostructured platform showed a suitable response to detect chloroform, with linear responses in the concentration range from 10 to 300 ppm and from 350 to 500 ppm and limits of detection of 47.9 and 15.4 ppm, respectively. The results suggest the PMMA_PFO electrospun nanofibers are highly potential materials for optical gas sensor applications based on luminescence quenching. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46128.
Reprocessing of chromed ABS parts with chemical pickling and new chrome plating
Authors: Kurek Ana Paula , Moll Regis Garcia , Herbst Giulia , Dotto Marta Elisa Rosso , Sellin Noeli 
Published: December 2017

ABSTRACTIn this work, chrome‐plated acrylonitrile–butadiene–styrene (ABS) parts containing defects in the deposited metal layer were pickled up to two times in hydrochloric and nitric acid under different immersion times. The influence of pickling on the properties of ABS was evaluated by thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy–attenuated total reflection (FTIR–ATR), scanning electron microscopy, atomic force microscopy, and roughness. The pickled parts were again chromed and evaluated by visual inspection and adhesion. The metallic layer was removed and a slight yellowing of the samples surface with the increase of pickling time. There were no significant changes in the thermal behavior of the material. Some of the components of ABS were removed, as evidenced by the reduction of the absorption peaks intensity in FTIR–ATR, by the increase of roughness and presence of pores on the surface. With the increase of the immersion time and the number of pickling, there was the formation of pores with larger sizes and decrease in roughness, making metal–polymer adhesion difficult. Only one pickling, under immersion time of 30 min, was adequate for the removal of the metallic layer, allowing new chrome plating. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46131.
Interplay between key variables of peroxide cured EPDM and evaluation of electromechanical efficiency for MV cables
Authors: Radosavljević Jelena , Nikolić Ljubiša 
Published: December 2017

ABSTRACTExtensive work has been done on ethylene‐propylene‐diene monomer (EPDM) vulcanizates and the main factors influencing their cure efficiency. However, very little attention has been given to the evolution of material properties and the interplay between key variables formulation. The effect of ethylene/propylene content and concentration of peroxide and type on viscoelastic and dielectric properties of EPDM elastomers was investigated using dynamic mechanical analysis and electric property measurements at room temperature. In order to compare results, these measurements were obtained by FTIR spectroscopy. Differences between real and imaginary (loss) part of the permittivity of EPDM/ dicumyl peroxide (DCP) composites were more significant than those in EPDM/di(tert‐butylperoxyisopropyl)benzene (DTBPIB) composites. For peroxide DTBPIB, the dielectric percolation limit moves further with the increase of ethylene content of EPDM. The dielectric percolation limit of the peroxide DTBPIB is found to be approximately 60 g at a 75% of ethylene in EPDM. The FTIR analysis showed that a termoxidative degradation was promoted at mixes with peroxide DCP at 45 and 75% of ethylene in EPDM. Therefore, we could interestingly show the decrease in electrical properties particularly associated with termoxidative degradation of peroxide DCP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46139.
Differences in Safety of Nonsteroidal Antiinflammatory Drugs in Patients With Osteoarthritis and Patients With Rheumatoid Arthritis
Authors: Solomon Daniel H. , Husni M. Elaine , Wolski Katherine E. , Wisniewski Lisa M. , Borer Jeffrey S. , Graham David Y. , Libby Peter , Lincoff A. Michael , Lüscher Thomas F. , Menon Venu , Yeomans Neville D. , Wang Qiuqing , Bao Weihang , Berger Manuela F. , Nissen Steven E. ,   the PRECISION Trial Investigators
Published: December 2017

ObjectiveTo determine the relative risks of cardiovascular (CV), gastrointestinal (GI), and renal adverse events during long‐term treatment with celecoxib, compared with ibuprofen and naproxen, in patients with osteoarthritis (OA) and patients with rheumatoid arthritis (RA).MethodsA total of 24,081 patients with OA or RA who had a moderate or high risk for CV disease were enrolled internationally into a double‐blind randomized controlled trial. Interventions included celecoxib at a dosage of 100–200 mg twice daily, ibuprofen at a dosage of 600–800 mg 3 times daily, or naproxen at a dosage of 375–500 mg twice daily. The main outcomes were the first occurrence of a major adverse CV event, GI event, or renal event, and mortality.ResultsIn the subgroup of patients with OA, the risk of a major adverse CV event was significantly reduced when celecoxib was compared with ibuprofen (hazard ratio [HR] 0.84, 95% confidence interval [95% CI] 0.72–0.99), but no significant difference was observed when celecoxib was compared with naproxen. In the RA subgroup, comparisons of celecoxib versus ibuprofen and celecoxib versus naproxen for the risk of major adverse CV events revealed HRs of 1.06 (95% CI 0.69–1.63) and 1.22 (95% CI 0.78–1.92), respectively. In the OA subgroup, comparisons of celecoxib versus ibuprofen for the risk of GI events showed an HR of 0.68 (95% CI 0.51–0.91), and a comparison of celecoxib versus naproxen showed an HR of 0.73 (95% CI 0.55–0.98). Duplicate comparisons in patients with RA revealed HRs of 0.48 (95% CI 0.22–1.07) and 0.54 (95% CI 0.24–1.24), respectively. In patients with OA, a comparison of celecoxib versus ibuprofen for the risk of renal events showed an HR of 0.58 (95% CI 0.40–0.82). In patients with RA, celecoxib treatment was associated with significantly lower mortality compared with naproxen treatment (HR 0.47, 95% CI 0.25–0.88).ConclusionTreatment with celecoxib at approved dosages conferred a similar or lower risk of CV, GI, and renal adverse events compared with treatment with ibuprofen or naproxen in patients with OA and patients with RA.
Microfluidic platforms for the study of neuronal injury in vitro
Authors: Shrirao Anil B. , Kung Frank H. , Omelchenko Anton , Schloss Rene S. , Boustany Nada N. , Zahn Jeffrey D. , Yarmush Martin L. , Firestein Bonnie L. 
Published: December 2017

AbstractTraumatic brain injury (TBI) affects 5.3 million people in the United States, and there are 12,500 new cases of spinal cord injury (SCI) every year. There is yet a significant need for in vitro models of TBI and SCI in order to understand the biological mechanisms underlying central nervous system (CNS) injury and to identify and test therapeutics to aid in recovery from neuronal injuries. While TBI or SCI studies have been aided with traditional in vivo and in vitro models, the innate limitations in specificity of injury, isolation of neuronal regions, and reproducibility of these models can decrease their usefulness in examining the neurobiology of injury. Microfluidic devices provide several advantages over traditional methods by allowing researchers to (1) examine the effect of injury on specific neural components, (2) fluidically isolate neuronal regions to examine specific effects on subcellular components, and (3) reproducibly create a variety of injuries to model TBI and SCI. These microfluidic devices are adaptable for modeling a wide range of injuries, and in this review, we will examine different methodologies and models recently utilized to examine neuronal injury. Specifically, we will examine vacuum‐assisted axotomy, physical injury, chemical injury, and laser‐based axotomy. Finally, we will discuss the benefits and downsides to each type of injury model and discuss how researchers can use these parameters to pick a particular microfluidic device to model CNS injury.
Hypoxia and transforming growth factor‐beta1 pathway activation promote Chinese Hamster Ovary cell aggregation
Authors: Qian Yueming , Rehmann Matthew S. , Qian Nan‐Xin , He Aiqing , Borys Michael C. , Kayne Paul S. , Li Zheng Jian 
Published: December 2017

AbstractSuspension cultivation is the preferred mode of operation for the large‐scale production of many biologics. Chinese Hamster Ovary (CHO) cells are anchorage‐dependent in origin, but they have been widely adapted to suspension culture. In suspension culture, formation of CHO cell aggregates is a common phenomenon and compromises cell culture performance in multiple ways. To better understand the underlying mechanisms that regulate cell aggregation, we utilized CHO‐specific transcriptome profiling as a screening tool and demonstrated that many genes encoding extracellular matrix (ECM) proteins were upregulated in the cultures with increased cell aggregation. Significantly, hypoxia was identified to be a cause for promoting CHO cell aggregation, and transforming growth factor beta1 (TGFβ1) pathway activation served as an intermediate step mediating this biological cascade. These transcriptomics findings were confirmed by cell culture experiments, and it was further demonstrated that adding recombinant TGFβ1 to the culture significantly increased ECM protein fibronectin expression and cell aggregation. The results of this study emphasize the importance of adequate mixing and oxygen supply for suspension cultures from a new angle, and regulating the TGFβ1 pathway is proposed as a new strategy for mitigating cell aggregation to improve cell culture performance.
Experimental and Numerical Investigations of a Dual‐Stage Cyclone Separator
Authors: Zhang Ting , Guo Kai , Liu Chunjiang , Li Yue , Tao Min , Shen Chong 
Published: December 2017

AbstractCyclone separators can be utilized in parallel to increase particle collection efficiency. However, this leads to a maldistribution problem that causes separation performance deterioration. To improve the flow distribution, a dual‐stage multicyclone separator (DSCS) was designed, containing a tangential‐inlet circle pathway cyclone array, an axial‐inlet radiation pathway cyclone array, and a cylindrical outer chamber. Experimental and computational fluid dynamics results revealed the gas‐particle flow distribution through multicyclone arrays. Effects of flow distribution on particle deposition were investigated experimentally. Particle trajectories inside the cyclone separators were also observed. The multicyclone array proved to generate a uniform inlet velocity distribution. The proposed cyclone separator can be considered as an option to accomplish dilute gas‐particle separation.
Towards High‐Throughput Modelling of Copper Reactivity Induced by Structural Disorder in Amyloid Peptides
Authors: La Penna Giovanni , Li Mai Suan 
Published: December 2017

AbstractTransition metal ions often interact with disordered proteins. The affinity is high enough to compete with structured proteins, but the catalytic activity of the metal centre is often out of control and, therefore, potentially dangerous for cells. An example is a single copper ion interacting with the amyloid‐β (Aβ) peptide and triplet dioxygen, an interaction that is fundamental in producing reactive oxygen species in neurodegeneration. High‐throughput modelling of the Cu‐Aβ‐O2 system was performed with the aim of providing a tool to dissect the structural features that characterise dangerous Cu‐based catalysts in neurodegeneration. This study showed that the production of superoxide is a process with low‐energy intermediate species, once a small population of high‐energy CuI‐Aβ complex is formed. This population is enhanced when Cu bridges two different peptides in 1:1 Cu:Aβ dimers. Despite the bias for high‐energy reduced reactant species, the reduction of CuII‐Aβ product by superoxide can also occur, in addition to that by ascorbate, because the structural disorder produces a small population of oxidant species characterised by unstable CuII coordination, coexisting with the most abundant reductant species, characterised by stable CuII coordination.
Stepwise Introduction of Cyano Groups into nido‐ and closo‐Undecaborate Clusters
Authors: Konieczka Szymon Z. , Schlüter Florian , Sindorf Christoph , Kerpen Christoph , Bernhardt Eduard , Finze Maik 
Published: December 2017

AbstractEleven‐vertex closo and nido boron clusters with one or two exo‐cyano groups were obtained by a series of consecutive cage‐opening and cage‐closure reactions starting from K2[closo‐B11H11] (K21). In the first step, K21 reacts with KCN in water at elevated temperatures to yield [7‐NC‐nido‐B11H12]2− (5 a). Oxidation of 5 a with PbO2 gives [NC‐closo‐B11H10]2− (2). In analogous subsequent reactions, dianion 2 was converted with KCN regioselectively to [7,9‐(NC)2‐nido‐B11H11]2− (6 a), which was further oxidized to [(NC)2‐closo‐B11H9]2− (3). The {nido‐B11} dianions 5 a and 6 a were protonated to yield [7‐NC‐nido‐B11H13]− (5 b) and [7,9‐(NC)2‐nido‐B11H12]− (6 b). All anions were studied by NMR spectroscopy and, except for 6 b, salts of all anions were characterized by IR and Raman spectroscopy and by elemental analysis. The position of the cyano group(s) in 5 a and 6 a were confirmed by NMR data and single‐crystal X‐ray diffraction studies on [Ph4P]25 a⋅CH2Cl2 and [Et4N]26 a. The {closo‐B11} clusters are fluxional in solution. In the crystal of [EMIm]22 the BCN vertex is in the 2‐position. Two isomers of dianion 3, [2,3‐(NC)2‐closo‐B11H9]2− and [2,6‐(NC)2‐closo‐B11H9]2−, were identified in the crystal of its [Et4N]+ salt. The peak oxidation potentials Epa of anions 1–3, 5 a, 6 a, 5 b, and [nido‐B11H14]− (4 b), determined by cyclic voltammetry, increase with increasing number of cyano groups. Increasing Epa in the order 1<2<3 parallels the increasing reactivity toward cyanide anions.
Analysis of censored data under heteroscedastic transformation regression models with unknown transformation function
Authors: Wang Qihua , Wang Xuan 
Published: December 2017

AbstractConsider a censored heteroscedastic transformation regression model where both the transformation function and the error distribution function are completely unknown. A method is developed to estimate the transformation function, the regression parameter vector, and the single index parameter vector of the variance function by establishing an expression for the transformation function and two estimating equations for both the parameter vectors. It is shown that the estimator of the transformation function converges weakly to a mean zero Gaussian process, and the parametric estimators are asymptotically normal. All the estimators converge to their true values in probability at a rate proportional to . Simulation studies are conducted to evaluate the finite sample behaviour of the proposed estimators, and a real data analysis is used to illustrate the proposed estimating method. The Canadian Journal of Statistics 46: 233–245; 2018 © 2017 Statistical Society of Canada
Empirical likelihood inference for multiple censored samples
Authors: Cai Song , Chen Jiahua 
Published: December 2017

AbstractWe present a semiparametric approach to inference on the underlying distributions of multiple right‐ and/or left‐censored samples with fixed censoring points and focus on effective estimation of population quantiles and distribution functions. We pool information across multiple censored samples through a semiparametric density ratio model and propose an empirical likelihood approach to inference. This approach achieves high efficiency without making restrictive model assumptions. The resultant estimator is asymptotically normal, and the resulting distribution function estimator and quantile estimator are more efficient than estimators obtained from the classic nonparametric methods, such as the empirical distribution and sample quantile. In addition, the proposed approach permits consistent estimation of distribution functions and quantiles on a larger domain than would otherwise be possible using the classic methods. Simulation studies suggest that the proposed method is robust against misspecification of the density ratio function and against outliers. Our approach is further illustrated with an application to the analysis of real lumber strength data. The Canadian Journal of Statistics 46: 212–232; 2018 © 2017 Statistical Society of Canada
Incidence of thromboembolic and bleeding events in patients with newly diagnosed nonvalvular atrial fibrillation: An Asian multicenter retrospective cohort study in Singapore
Authors: Wee Xue Ting , Ho Lih Maan , Ho Han Kiat , Lee Joyce Yu‐Chia , Yap Chun Wei , William Henry , Chan Linus Chong En , Tay Hooi Ching , Goh Cynthia Eei Mei , Tan Doreen Su‐Yin 
Published: December 2017

BackgroundReal‐world effectiveness and safety of antithrombotics in nonvalvular atrial fibrillation (NVAF) patients in Singapore has not been thoroughly studied.Hypothesis.Users of various antithrombotics experience a significantly different risk of stroke and major bleed compared with warfarin users.MethodsThis multicenter retrospective cohort study included patients age ≥ 21 years newly diagnosed with NVAF between July 2012 and September 2015. Using electronic medical records, data on patients' demographics, antithrombotics prescribed, and CHA2DS2‐VASc and HAS‐BLED risk factors were collected. Patients were followed for 1 year from diagnosis for the primary effectiveness and safety endpoints of incident stroke or systemic embolism and major bleed, respectively. The secondary safety endpoint was overall bleed. Hazard ratios (HR) were determined from Cox regression.ResultsOf 743 patients included, 224 were on warfarin, 156 on direct oral anticoagulants (DOACs), 277 on single antiplatelet therapy (SAPT), 28 on dual antiplatelet therapy (DAPT), and 58 on no therapy. Mean age (±SD) was 68.7 ± 13.0 years. Compared with warfarin users, SAPT (adjusted [adj.] HR: 3.70, 95% confidence interval [CI]: 1.21‐11.3) and DAPT users (adj. HR: 10.1, 95% CI: 1.51‐67.2) were more likely to develop thromboembolic outcomes. Also, DOAC users (adj. HR: 0.304, 95% CI: 0.158‐0.585), SAPT users (adj. HR: 0.142, 95% CI: 0.0680‐0.295), and DAPT users (adj. HR: 0.112, 95% CI: 0.0146‐0.857) were less likely to experience any bleed compared with warfarin users.ConclusionsSAPT and DAPT are less effective than warfarin in NVAF patients. DOACs may be considered in view of lower risk of overall bleed.