bluuebunny/crossref_metadata_2025 huggingface dataset:
Actin dynamics switches two distinct modes of endosomal fusion in yolk sac visceral endoderm cells
Authors: Koike Seiichi , Tachikawa Masashi , Tsutsumi Motosuke , Okada Takuya , Nemoto Tomomi , Keino-Masu Kazuko , Masu Masayuki
Published: September 2024

Membranes undergo various patterns of deformation during vesicle fusion, but how this membrane deformation is regulated and contributes to fusion remains unknown. In this study, we developed a new method of observing the fusion of individual late endosomes and lysosomes by using yolk sac visceral endoderm cells that have huge endocytic vesicles. We found that there were two distinct fusion modes that were differently regulated. In homotypic fusion, two late endosomes fused quickly, whereas in heterotypic fusion they fused to lysosomes slowly. Mathematical modeling showed that vesicle size is a critical determinant of these fusion types and that membrane fluctuation forces can overcome the vesicle size effects. We found that actin filaments were bound to late endosomes and forces derived from dynamic actin remodeling were necessary for quick fusion during homotypic fusion. Furthermore, cofilin played a role in endocytic fusion by regulating actin turnover. These data suggest that actin promotes vesicle fusion for efficient membrane trafficking in visceral endoderm cells.
Cyclic di-GMP as an Antitoxin Regulates Bacterial Genome Stability and Antibiotic Persistence in Biofilms
Authors: Liao Hebin , Yan Xiaodan , Wang Chenyi , Huang Chun , Zhang Wei , Xiao Leyi , Jiang Jun , Bao Yongjia , Huang Tao , Zhang Hanbo , Guo Chunming , Zhang Yufeng , Pu Yingying
Published: September 2024

Biofilms are complex bacterial communities characterized by a high persister prevalence, which contributes to chronic and relapsing infections. Historically, persister formation in biofilms has been linked to constraints imposed by their dense structures. However, we observed an elevated persister frequency accompanying the stage of cell adhesion, marking the onset of biofilm development. Subsequent mechanistic studies uncovered a comparable type of toxin-antitoxin (TA) module (TA-like system) triggered by cell adhesion, which is responsible for this elevation. In this module, the toxin HipH acts as a genotoxic deoxyribonuclease, inducing DNA double strand breaks and genome instability. While the second messenger c-di-GMP functions as the antitoxin, exerting control over HipH expression and activity. The dynamic interplay between c-di-GMP and HipH levels emerges as a crucial determinant governing genome stability and persister generation within biofilms. These findings unveil a unique TA system, where small molecules act as the antitoxin, outlining a biofilm-specific molecular mechanism influencing genome stability and antibiotic persistence, with potential implications for treating biofilm infections.
A unifying account of replay as context-driven memory reactivation
Authors: Zhou Zhenglong , Kahana Michael J , Schapiro Anna C
Published: September 2024

During rest and sleep, sequential neural activation patterns corresponding to awake experience re-emerge, and this replay has been shown to benefit subsequent behavior and memory. Whereas some studies show that replay directly recapitulates recent experience, others demonstrate that replay systematically deviates from the temporal structure, the statistics, and even the content of recent experience. Given these disparate characteristics, what is the nature and purpose of replay? Here, we offer a theoretical framework in which replay reflects simple context-guided processes that facilitate memory. We suggest that, during awake learning, the brain associates experiences with the contexts in which they are encoded, at encoding rates that vary according to the salience of each experience. During quiescence, replay emerges as the result of a cascade of autonomous bidirectional interactions between contexts and their associated experiences, which in turn facilitates memory consolidation. A computational model instantiating this proposal explains numerous replay phenomena, including findings that existing models fail to account for and observations that have been predominantly construed through the lens of reinforcement learning. Our theory provides a unified, mechanistic framework of how the brain initially encodes and subsequently replays experiences in the service of memory consolidation.
Comprehensive analysis of bioplastics: life cycle assessment, waste management, biodiversity impact, and sustainable mitigation strategies
Authors: Yadav Kushi , Nikalje Ganesh Chandrakant
Published: September 2024

Bioplastics are emerging as a promising alternative to traditional plastics, driven by the need for more sustainable options. This review article offers an in-depth analysis of the entire life cycle of bioplastics, from raw material cultivation to manufacturing and disposal, with a focus on environmental impacts at each stage. It emphasizes the significance of adopting sustainable agricultural practices and selecting appropriate feedstock to improve environmental outcomes. The review highlights the detrimental effects of unsustainable farming methods, such as pesticide use and deforestation, which can lead to soil erosion, water pollution, habitat destruction, and increased greenhouse gas emissions. To address these challenges, the article advocates for the use of efficient extraction techniques and renewable energy sources, prioritizing environmental considerations throughout the production process. Furthermore, the methods for reducing energy consumption, water usage, and chemical inputs during manufacturing by implementing eco-friendly technologies. It stresses the importance of developing robust disposal systems for biodegradable materials and supports recycling initiatives to minimize the need for new resources. The holistic approach to sustainability, including responsible feedstock cultivation, efficient production practices, and effective end-of-life management. It underscores the need to evaluate the potential of bioplastics to reduce plastic pollution, considering technological advancements, infrastructure development, and increased consumer awareness. Future research should focus on enhancing production sustainability, understanding long-term ecological impacts, and advancing bioplastics technology for better performance and environmental compatibility. This comprehensive analysis of bioplastics’ ecological footprint highlights the urgent need for sustainable solutions in plastic production.
Aplicação da função qualidade (QFD) no processo de atendimento ao cliente em uma rede de supermercado
Authors: Semmer Marcelo , Silva Robson de Faria , Bannach Daniel Gauloski
Published: September 2024

Este artigo explora a utilização do QFD para abordar questões associadas à comercialização de bens e ao atendimento ao cliente em uma rede de supermercados. A rede teve dificuldade em lidar com o feedback dos clientes em relação à variedade de produtos, ao design da loja e à eficácia do serviço. O objetivo principal é utilizar o QFD para identificar e classificar as necessidades do cliente, que foram então transformadas em melhorias práticas que poderiam ser realizadas para melhorar a experiência do consumidor. O método mostrou-se eficaz para: sistematizar um grande conjunto de informações internas e externas à rede, facilitando o planejamento posterior de ações de atendimento; identificar as necessidades dos consumidores bem como priorizar procedimento que melhor atendem a voz do cliente alinhada a capacidade de prestação de serviço das unidades. Os resultados demonstraram que a implementação do QFD prioriza a satisfação do cliente, e aumenta a vantagem competitiva da rede de supermercados no mercado. Conclui-se que o QFD é uma ferramenta promissora que pode ser utilizada para alinhar as operações da empresa com as demandas dos clientes, o que levará a melhorias significativas na qualidade do atendimento e na percepção positiva do mercado.
Integrated Effect of Trichoderma harzianum with Selected Botanicals Extracts on Alternaria Leaf Spot of Broccoli (Brassica oleracea var. italica) Caused by Alternaria brassicae (Berk.) Sacc.
Authors: Devi Khumanthem Pushpa , Zacharia Sunil
Published: September 2024

Broccoli (Brassicae oleracea var. italica) is an important cole crop vegetable, belong to family Brassicaceae. Alternaria leaf spot caused by Alternaria brassicae is one of the serious diseases in broccoli. In vitro and in vivo experiment were conducted at the research plot of the Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh in Rabi season 2023-2024, to evaluate Trichoderma harzianum and botanicals on Alternaria leaf spot of broccoli caused by A.brassicae. In vitro condition, five botanical extracts were taken at the concentration 10% and T. harzianum at 10% and Mancozeb at 0.2% (treated check). In vivo condition, eight treatments were taken and all seedlings were treated with T. harzianum at 10%, Mancozeb at 0.2% and foliar spray of botanical extracts @10% except T0– control (untreated check) and (treated check). In vitro condition, among the treatments Neem leaf extract at 10% were observed effective in the per cent disease inhibition (%) (79.77) followed by Eucalyptus leaf extract at 10% (75.69). Among the treatments, under In vivo condition, T3- T. harzianum (S.T.) + Neem leaf extract (F.S.) was observed minimum disease intensity (16.59, 19.85 and 23.28 %) at 45,60 and 75 DAT, respectively. Maximum plant height (9.78, 23.84 and 36.66cm) at 30,60 and 90 DAT, number of leaves per plant (9.36, 17.26 and 28.00), head weight (0.38 kg) and yield (9.68 t/ha) were found in T3- T. harzianum (S.T.) and Neem leaf extract (F.S.) when compared to treated T7- mancozeb (treated check) and T0- Control (untreated check).
Synthesis of Mesoporous ZnO•SiO2 Nanocomposite from Rice Husk for Enhanced Degradation of Organic Substances Including Janus Green B under Visible Light
Authors: Nguyen Thu Huong , Vu Tuan Cuong , Le Trung Phong , Nguyen Thu Huyen , Do Xuan Truong , Vu Anh-Tuan
Published: September 2024

Rice husk (RH) is often mentioned as an agricultural by-product, often used in the pass as fertilizer and for raw burning. With modern science, RH have been researched and found many new potential benefits and applications. In this study, RH were used to synthesize amorphous SiO2, which was used to prepare the ZnO•SiO2 nanocomposites by a hydrothermal method. The as-synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and N2 adsorption/desorption isotherm. Their photocatalytic properties were studied by an ultraviolet-vis spectrophotometer and a fluorescence spectrophotometer. The ZnO•SiO2 nanocomposite has an excellent ability to degrade organic substances such as dyes, antibiotics, caffeine, etc. The effects of operating parameters on the photo-degradation reaction progress, including catalyst dosage, initial dye concentration, and pH of the initial dye were investigated in detail. In addition, the photodegradation rate of the dye on the ZnO•SiO2 nanocomposite was evaluated using the pseudo-first-order model. The ZnO•SiO2 nanocomposite can be used as a photocatalyst for wastewater treatment as it detaches much more easily from the solution. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Modulation of the Microstructure and Enhancement of the Photocatalytic Performance of g-C3N4 by Thermal Exfoliation
Authors: Zhao Xinshan , Yu Junwei , Meng Tingyu , Luo Yuanyuan , Fu Yanzhen , Li Zhao , Tian Lin , Sun Limei , Li Jing
Published: September 2024

This work explores the impact of reaction temperature during thermal exfoliation treatment of bulk-g-C3N4 in the air atmosphere on the structure and performance of the resulting CN photocatalyst. The analysis conducted using XRD, FT-IR, XPS, SEM, and elements mapping tests, illustrated an increase in nitrogen-vacancy and oxygen content on the surface of the CN photocatalyst, resulting in a porous and sparse structure, changes in crystal size, and improved visible light absorption performance. The photocatalytic reduction experiments of hexavalent chromium (Cr(VI)) showed that the CN-540 showed the highest reduction rate of 96.9%, with a reaction rate constant 6.21 times that of bulk-g-C3N4. After 100 min of illumination, the photocatalytic degradation rates of CN-540 for TC-HCl and RhB were 66.7% and 60.6%, respectively. The TOC test results indicated mineralization rates of 51.5% for TC-HCl and 46.6% for RhB. Room temperature fluorescence spectroscopy (PL), transient photocurrent response (TPC), and electrochemical impedance spectroscopy (EIS) measurements confirmed the excellent photogenerated charge carrier separation and transport efficiency of CN-540. The photocatalytic mechanism for reducing Cr(VI) by CN-540 was elucidated based on the active species •OH and •O2– and Mott-Schottky (M-S) tests. This study provides experimental data for optimizing the photocatalytic performance of g-C3N4 and paves a new way for developing efficient photocatalysts. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Storm time equatorial plasma bubble zonal drift reversal due to disturbance Hall electric field over the Brazilian region
Authors: Santos A. M. , Abdu M. A. , Souza J. R. , Sobral J. H. A. , Batista I. S. , Denardini C. M.
Published: May 2016

The dynamics of equatorial ionospheric plasma bubbles over Brazilian sector during two magnetic storm events are investigated in this work. The observations were made at varying phases of magnetic disturbances when the bubble zonal drift velocity was found to reverse westward from its normally eastward velocity. Calculation of the zonal drift based on a realistic low‐latitude ionosphere modeled by the Sheffield University Plasmasphere‐Ionosphere Model showed on a quantitative basis a clear competition between vertical Hall electric field and disturbance zonal winds on the variations observed in the zonal velocity of the plasma bubble. The Hall electric field arising from enhanced ratio of field line‐integrated conductivities, ΣH/ΣP, is most often generated by an increase in the integrated Hall conductivity, arising from enhanced energetic particle precipitation in the South American Magnetic Anomaly region for which evidence is provided from observation of anomalous sporadic E layers over Cachoeira Paulista and Fortaleza. Such sporadic E layers are also by themselves evidence for the development of the Hall electric field that modifies the zonal drift.
Temporal and spatial deviation in F2 peak parameters derived from FORMOSAT‐3/COSMIC
Authors: Kumar Sanjay , Singh R. P. , Tan Eng Leong , Singh A. K. , Ghodpage R. N. , Siingh Devendraa
Published: May 2016

The plasma frequency profiles derived from the Constellation of Observing System for Meteorology, Ionosphere and Climate (COSMIC) radio occultation measurements are compared with ground‐based ionosonde data during the year 2013. Equatorial and midlatitude five stations located in the Northern and Southern Hemisphere are considered: Jicamarca, Jeju, Darwin, Learmonth, and Juliusruh. The aim is to validate the COSMIC‐derived data with ground‐based measurements and to estimate the difference in plasma frequency (which represents electron density) and height of F2 layer peak during the daytime/nighttime and during different seasons by comparing the two data sets. Analysis showed that the nighttime data are better correlated than the daytime, and the maximum difference occurs at the equatorial ionospheric anomaly (EIA) station as compared to lower and midlatitude stations during the equinox months. The difference between daytime and nighttime correlations becomes insignificant at midlatitude stations. The statistical analysis of computed errors in foF2 (hmF2) showed Gaussian nature with the most probable error range of ±15% (±10%) at the equatorial and EIA stations, ±9% (±7%) outside the EIA region which reduced to ±8% (±6%) at midlatitude stations. The reduction in error at midlatitudes is attributed to the decrease in latitudinal electron density gradients. Comparing the analyzed data during the three geomagnetic storms and quiet days of the same months, it is observed that the differences are significantly enhanced during storm periods and the magnitude of difference in foF2 increases with the intensity of geomagnetic storm.
Rapid spatiotemporal variations in rift structure during development of the Corinth Rift, central Greece
Authors: Nixon Casey W. , McNeill Lisa C. , Bull Jonathan M. , Bell Rebecca E. , Gawthorpe Robert L. , Henstock Timothy J. , Christodoulou Dimitris , Ford Mary , Taylor Brian , Sakellariou Dimitris , Ferentinos George , Papatheodorou George , Leeder Mike R. , Collier Richard E.LI. , Goodliffe Andrew M. , Sachpazi Maria , Kranis Haralambos
Published: May 2016

The Corinth Rift, central Greece, enables analysis of early rift development as it is young (<5 Ma) and highly active and its full history is recorded at high resolution by sedimentary systems. A complete compilation of marine geophysical data, complemented by onshore data, is used to develop a high‐resolution chronostratigraphy and detailed fault history for the offshore Corinth Rift, integrating interpretations and reconciling previous discrepancies. Rift migration and localization of deformation have been significant within the rift since inception. Over the last circa 2 Myr the rift transitioned from a spatially complex rift to a uniform asymmetric rift, but this transition did not occur synchronously along strike. Isochore maps at circa 100 kyr intervals illustrate a change in fault polarity within the short interval circa 620–340 ka, characterized by progressive transfer of activity from major south dipping faults to north dipping faults and southward migration of discrete depocenters at ~30 m/kyr. Since circa 340 ka there has been localization and linkage of the dominant north dipping border fault system along the southern rift margin, demonstrated by lateral growth of discrete depocenters at ~40 m/kyr. A single central depocenter formed by circa 130 ka, indicating full fault linkage. These results indicate that rift localization is progressive (not instantaneous) and can be synchronous once a rift border fault system is established. This study illustrates that development processes within young rifts occur at 100 kyr timescales, including rapid changes in rift symmetry and growth and linkage of major rift faults.
First three dimensional wave characteristics in the daytime upper atmosphere derived from ground‐based multiwavelength oxygen dayglow emission measurements
Authors: Pallamraju Duggirala , Karan Deepak K. , Phadke Kedar A.
Published: May 2016

First results on the three‐dimensional wave characteristics in the daytime upper atmosphere have been derived using measurements of oxygen dayglow emissions at 557.7, 630.0, and 777.4 nm that originate at around 130, 230, and 300 km (peak of the F region). The horizontal scale sizes of gravity waves (GWs), their time periods, phase propagation angle (counterclockwise from east), and phase speeds are found to vary in the range of 27–227 km, 32–70 min, 207°–253°, and 6–76 ms−1, respectively. Two‐dimensional measurements on the horizontal scale sizes in the daytime have not been reported before. Further, using Hines' (1960) dispersion relation for GWs, vertical scale sizes and phase angles have also been derived. This technique opens up new possibilities in the investigations of daytime wave dynamics in three dimensions in the upper atmosphere.
Ice‐nucleating particle emissions from photochemically aged diesel and biodiesel exhaust
Authors: Schill G. P. , Jathar S. H. , Kodros J. K. , Levin E. J. T. , Galang A. M. , Friedman B. , Link M. F. , Farmer D. K. , Pierce J. R. , Kreidenweis S. M. , DeMott P. J.
Published: May 2016

Immersion‐mode ice‐nucleating particle (INP) concentrations from an off‐road diesel engine were measured using a continuous‐flow diffusion chamber at −30°C. Both petrodiesel and biodiesel were utilized, and the exhaust was aged up to 1.5 photochemically equivalent days using an oxidative flow reactor. We found that aged and unaged diesel exhaust of both fuels is not likely to contribute to atmospheric INP concentrations at mixed‐phase cloud conditions. To explore this further, a new limit‐of‐detection parameterization for ice nucleation on diesel exhaust was developed. Using a global‐chemical transport model, potential black carbon INP (INPBC) concentrations were determined using a current literature INPBC parameterization and the limit‐of‐detection parameterization. Model outputs indicate that the current literature parameterization likely overemphasizes INPBC concentrations, especially in the Northern Hemisphere. These results highlight the need to integrate new INPBC parameterizations into global climate models as generalized INPBC parameterizations are not valid for diesel exhaust.
An equatorial solar wind model with angular momentum conservation and nonradial magnetic fields and flow velocities at an inner boundary
Authors: Tasnim S. , Cairns Iver H.
Published: May 2016

An analytic, self‐consistent, theoretical model for the solar wind is developed that generalizes previous models to include all of the following: conservation of angular momentum, frozen‐in magnetic fields, both radial (r) and azimuthal (ϕ) components of the magnetic field (Br and Bϕ) and velocity (vr and vϕ) from the inner boundary rs to 1 AU, and the detailed tracing back of observations at 1 AU to the inner boundary and all intervening (r,ϕ). The new model applies near the solar equatorial plane, assumes constant radial wind speed at each heliolongitude, and enforces corotation at the inner boundary. It is shown that the new theoretical model can be reduced to the previous models in the appropriate limits. We apply the model to two solar rotations of Wind spacecraft data, one near solar minimum (1–27 August 2010) and one near solar maximum (1–27 July 2002). The model analytically predicts the Alfvénic critical radius ra from the radial Alfvénic Mach number observed at 1 AU. Typically, the values are less than 15 solar radii, in agreement with some recent observations, and vary with longitude. Values of vϕ(r,ϕ) are predicted from the model, being always in the sense of corotation but varying in magnitude with r and ϕ. Reasonable and self‐consistent results are found for Br(r,ϕ), Bϕ(r,ϕ), vϕ(r,ϕ), and n(r,ϕ) from rs to 1 AU. Both the azimuthal and radial magnetic fields at rs vary with time by more than an order of magnitude and usually |Br(rs,ϕs)|≥|Bϕ(rs,ϕs)|. Typically, though not always, magnetic contributions to the total angular momentum are small. Interestingly, however, the azimuthal flow velocities observed at 1 AU are not always in the corotation direction and usually have much larger magnitudes than predicted by the model. Conservation of angular momentum alone cannot explain these azimuthal velocities and the standard interpretation involving stream‐stream interactions and dynamical behavior seems reasonable. Issues regarding the model's applicability appear to be due to the assumptions of corotation and constant wind speed breaking down below the Alfvén critical radius.
Highly Emissive Nd3+‐Sensitized Multilayered Upconversion Nanoparticles for Efficient 795 nm Operated Photodynamic Therapy
Authors: Lu Feng , Yang Lin , Ding Yujie , Zhu Jun‐Jie
Published: May 2016

Photodynamic therapy (PDT) is a noninvasive and site‐specific therapeutic technique for the clinical treatment of various of superficial diseases. In order to tuning the operation wavelength and improve the tissue penetration of PDT, rare‐earth doped upconversion nanoparticles (UCNPs) with strong anti‐stokes emission are introduced in PDT recently. However, the conventional Yb3+‐sensitized UCNPs are excited at 980 nm which is overlapped with the absorption of water, thus resulting in strong overheating effect. Herein, a convenient but effective design to obtain highly emissive 795 nm excited Nd3+‐sensitized UCNPs (NaYF4:Yb,Er@NaYF4:Yb0.1Nd0.4@NaYF4) is reported, which provides about six times enhanced upconversion luminescence, comparing with traditional UCNPs (NaYF4:Yb,Er@NaYF4). A colloidal stable and non‐leaking PDT nanoplatform is fabricated later through a highly PEGylated mesoporous silica layer with covalently linked photosensitizer (Rose Bengal derivative). With as‐prepared Nd3+‐sensitized UCNPs, the nanoplatform can produce singlet oxygen more effective than traditional UCNPs. Significant higher penetration depth and lower overheating are demonstrated as well. All these features make as‐prepared nanocomposites excellent platform for PDT treatment. In addition, the nanoplatform with uniform size, high surface area, and excellent colloidal stability can be extended for other biomedical applications, such as imaging probes, biosensors, and drug delivery vehicles.
Nephroblastomatosis or Wilms tumor in a fourth patient with a somatic PIK3CA mutation
Authors: Gripp Karen W. , Baker Laura , Kandula Vinay , Conard Katrina , Scavina Mena , Napoli Joseph A. , Griffin Gregory C. , Thacker Mihir , Knox Rachel G. , Clark Graeme R. , Parker Victoria E. R. , Semple Robert , Mirzaa Ghayda , Keppler‐Noreuil Kim M.
Published: May 2016

Wilms tumor and nephroblastomatosis are associated with syndromic conditions including hemihyperplasia. Hemihyperplasia is genetically heterogeneous and may be the result of genomic abnormalities seen in Beckwith–Wiedemann syndrome, mosaic chromosome or genomic abnormalities, or somatic point mutations. Somatic missense mutations affecting the PI3K‐AKT‐MTOR pathway result in segmental overgrowth and are present in numerous benign and malignant tumors. Here, we report a fourth patient with asymmetric overgrowth due to a somatic PIK3CA mutation who had nephroblastomatosis or Wilms tumor. Similar to two of three reported patients with a somatic PIK3CA mutation and renal tumors, he shared a PIK3CA mutation affecting codon 1047, presented at birth with asymmetric overgrowth, and had fibroadipose overgrowth. Codon 1047 is most commonly affected by somatic mutations in PIK3CA‐related overgrowth spectrum (PROS). While the fibroadipose overgrowth phenotype appears to be common in individuals with PIK3CA mutations at codon 1047, individuals with a clinical diagnosis of Klippel–Trenaunay syndrome or isolated lymphatic malformation also had mutations affecting this amino acid. Screening for Wilms tumor in individuals with PROS‐related hemihyperplasia may be considered and, until the natural history is fully elucidated in larger cohort studies, may follow guidelines for Beckwith–Wiedemann syndrome, or isolated hemihyperplasia. It is not known if the specific PIK3CA mutation, the mosaic distribution, or the clinical presentation affect the Wilms tumor or nephroblastomatosis risk in individuals with PROS. © 2016 Wiley Periodicals, Inc.
Switchover of the Mechanism between Electron Transfer and Hydrogen‐Atom Transfer for a Protonated Manganese(IV)–Oxo Complex by Changing Only the Reaction Temperature
Authors: Jung Jieun , Kim Surin , Lee Yong‐Min , Nam Wonwoo , Fukuzumi Shunichi
Published: May 2016

Hydroxylation of mesitylene by a nonheme manganese(IV)–oxo complex, [(N4Py)MnIV(O)]2+ (1), proceeds via one‐step hydrogen‐atom transfer (HAT) with a large deuterium kinetic isotope effect (KIE) of 3.2(3) at 293 K. In contrast, the same reaction with a triflic acid‐bound manganese(IV)‐oxo complex, [(N4Py)MnIV(O)]2+‐(HOTf)2 (2), proceeds via electron transfer (ET) with no KIE at 293 K. Interestingly, when the reaction temperature is lowered to less than 263 K in the reaction of 2, however, the mechanism changes again from ET to HAT with a large KIE of 2.9(3). Such a switchover of the reaction mechanism from ET to HAT is shown to occur by changing only temperature in the boundary region between ET and HAT pathways when the driving force of ET from toluene derivatives to 2 is around −0.5 eV. The present results provide a valuable and general guide to predict a switchover of the reaction mechanism from ET to the others, including HAT.
Amelioration of electrochemical and photovoltaic performances on P(VP‐co‐VAc) based gel polymer electrolyte by incorporating double salt for dye‐sensitized solar cells
Authors: Robin S. , Ng H. M. , Ramesh S. , Ramesh K.
Published: May 2016

Dye‐sensitized solar cell (DSSC) is an alternative photovoltaic application used to replace the liquid electrolyte dependent conventional photovoltaic cell. In this research, gel polymer electrolyte (GPE) was used to replace the unstable liquid electrolyte. This GPE consists of poly[1‐vinylpyrrolidone‐co‐vinyl acetate] (P[VP‐co‐VAc]), tetrabutylammonium iodide (TBAI), sodium iodide (NaI), iodine (I2), ethylene carbonate (EC), and propylene carbonate (PC). The GPE was tested for its ionic conductivity and an optimum level was reached at sample with 30% TBAI and 6% NaI at 1.17 × 10−3 S cm−1. The DSSC was then fabricated with all GPEs and a photovoltaic performance study was conducted. As a result, the highest photovoltaic conversion efficiency (PCE), η for a single salt was 3.04% for 40% TBAI. When a second salt is added, the system showed improvement in efficiency, η to 4.54% with short circuit current density, Jsc of 11.02 mA cm−2 and open circuit voltage, Voc of 0.67 V and FF of 61%. The other changes after the addition of TBAI and NaI salts have been observed through X‐ray diffraction, Fourier transformation and thermal analysis studies. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43805.
Morphology, structure, and properties of metal oxide/polymer nanocomposite electrospun mats
Authors: Hoogesteijn von Reitzenstein Natalia , Bi Xiangyu , Yang Yu , Hristovski Kiril , Westerhoff Paul
Published: May 2016

Adding nanoparticles into polymer solutions before electrospinning creates unique hierarchical morphologies dispersed throughout small diameter nanoparticle‐polymeric fibers. Effects of polymer composition, nanoparticle (NP) type, loading, and electrospinning voltage conditions were studied. As examples, indium, iron, and titanium oxide engineered nanoparticles (NPs) were dispersed into polyvinylpyrrolidone or polystyrene and electrospun. NP loadings below 5 wt % did not affect critical voltage required for Taylor cone formation, whereas higher NP loadings require higher critical voltages. Polymeric fiber thickness and macroscopic morphology is not impacted by up to 5 wt % NP loadings, and NP dispersion throughout the fibers were similar to their dispersion in initial polymer suspension. NP loadings above 5 wt % increased viscosity, which decrease subsequent fiber diameter. Experiments in water containing inorganic and organic pollutants in water demonstrate that the polymer is largely nonporous. This work enables design of multifunctional nanomaterial‐polymer composite fibers for wide‐ranging applications such as water and air treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43811.
Eso‐Based Adaptive Robust Control of Dual Motor Driving Servo System
Authors: Ren Xuemei , Li Dongwu , Sun Guofa , Zhao Wei
Published: May 2016

Based on extended state observer (ESO), we propose an adaptive robust control (ARC) for a dual motor driving servo system, in which there exist nonlinearities affecting control performance. To apply ESO and estimate the lumped uncertainty online, backlash and friction are analyzed and the nonlinear model of the plant is derived. We achieve several control objectives. First, the bias torque is considered in order to eliminate the effect of backlash. Second, the speed feedback is used to maintain the speed synchronization of motors. Then, to achieve feedforward control, finite‐time ESO is designed to estimate the unknown nonlinearities online. Furthermore, the ESO‐based adaptive robust controller is designed to guarantee L∞ of tracking error by an initialization method, maintaining the transient performance of tracking behavior. Finally, extensive experimental results on a practical test rig validate the effectiveness of our proposed method.
Purification and characterization of a high salt‐tolerant alginate lyase from Cobetia sp. WG‐007
Authors: Gong Jin‐Song , Liu Xu‐Mei , Zhang Ming‐Jie , Li Heng , Geng Yan , Li Hui , Li Jing , Lu Zhen‐Ming , Xu Zheng‐Hong , Shi Jin‐Song
Published: May 2016

An alginate lyase producing bacterial strain, Cobetia sp. WG‐007, was isolated and identified from rotting seaweed. The alginate lyase, Aly‐W02, was purified by procedures of ultrafiltration, Q‐Sepharose Fast Flow, Phenyl Sepharose 6 Fast Flow, and Superdex‐G100 with specific activity of 21,285.5 U/mg. Aly‐W02 had an apparent molecular mass of 35 kDa. It exhibited maximum activity at 45 °C in 50 mM sodium phosphate buffer (pH 8.5). This alginate lyase was stable in the pH range of 6.0–8.5. Among the tested metal ions, the addition of K+, Na+, and Mg2+ ions can enhance the enzyme activities, while Ba2+, Ni+, Cu2+, Mn2+, Zn2+, Ag+, and ethylenediaminetetraacetic acid decreased the activities. It displayed high salt‐tolerant ability; 0.8 M NaCl or 1.5 M KCl significantly enhanced the enzyme activity. Furthermore, Aly‐W02 mainly released disaccharide, trisaccharide, and tetrasaccharid from alginate. It showed potential in producing low molecular weight alginate oligosaccharides.
Single-stage resection and microwave ablation for bilobar colorectal liver metastases
Authors: Philips P , Groeschl R T , Hanna E M , Swan R Z , Turaga K K , Martinie J B , Iannitti D A , Schmidt C , Gamblin T C lark , Martin R C G
Published: May 2016

Background

Patients undergoing liver resection combined with microwave ablation (MWA) for bilobar colorectal metastasis may have similar overall survival to patients who undergo two-stage hepatectomy, but with less morbidity.

Methods

This was a multi-institutional evaluation of patients who underwent MWA between 2003 and 2012. Morbidity (90-day) and mortality were compared between patients who had MWA alone and those who underwent combined resection and MWA (CRA). Mortality and overall survival after CRA were compared with published data on two-stage resections.

Results

Some 201 patients with bilobar colorectal liver metastasis treated with MWA from four high-volume institutions were evaluated (100 MWA alone, 101 CRA). Patients who had MWA alone were older, but the groups were otherwise well matched demographically. The tumour burden was higher in the CRA group (mean number of lesions 3·9 versus 2·2; P = 0·003). Overall (31·7 versus 15·0 per cent; P = 0·006) and high-grade (13·9 versus 5·0 per cent; P = 0·030) complication rates were higher in the CRA group. Median overall survival was slightly shorter in the CRA group (38·4 versus 42·2 months; P = 0·132) but disease-free survival was similar (10·1 versus 9·3 months; P = 0·525). The morbidity and mortality of CRA compared favourably with rates in the existing literature on two-stage resection, and survival data were similar.

Conclusion

Single-stage hepatectomy and MWA resulted in survival similar to that following two-stage hepatectomy, with less overall morbidity.
Did a coach's comments, behavior justify dismissal?
Authors: Gelpi Aileen
Published: May 2016

Gidget Pambianchi was head coach of the Arkansas Tech University women's softball team in 2011 while Steve Mullins was the athletics director.
Immortalized bovine mammary epithelial cells express stem cell markers and differentiate in vitro
Authors: Hu Han , Zheng Nan , Gao Haina , Dai Wenting , Zhang Yangdong , Li Songli , Wang Jiaqi
Published: May 2016

The bovine mammary epithelial cell is a secretory cell, and its cell number and secretory activity determine milk production. In this study, we immortalized a bovine mammary epithelial cell line by SV40 large T antigen gene using a retrovirus based on Chinese Holstein primary mammary epithelial cells (CMEC) cultured in vitro. An immortalized bovine mammary epithelial cell line surpassed the 50‐passage mark and was designated the CMEC‐H. The immortalized mammary epithelial cells grew in close contact with each other and exhibited the typical cobblestone morphology characteristic with obvious boundaries. The telomerase expression of CMEC‐H has consistently demonstrated the presence of telomerase activity as an immortalized cell line, but the cell line never induced tumor formation in nude mice. CMEC‐H expressed epithelial (cytokeratins CK7, CK8, CK18, and CK19), mesenchymal (vimentin), and stem/progenitor (CD44 and p63) cell markers. The induced expression of milk proteins, αS1‐casein, β‐casein, κ‐casein, and butyrophilin, indicated that CMEC‐H maintained the synthesis function of the mammary epithelial cells. The established immortalized bovine mammary epithelial cell line CMEC‐H is capable of self‐renewal and differentiation and can serve as a valuable reagent for studying the physiological mechanism of the mammary gland.
Direct transfemoral transcatheter aortic valve implantation without balloon pre‐dilatation using the Edwards Sapien XT valve
Authors: Bandali Alykhan , Parry‐Williams Gemma , Kassam Aliya , Palmer Sonny , Williams Paul D. , de Belder Mark A. , Owens Andrew , Goodwin Andrew , Muir Douglas F.
Published: May 2016

Objectives

To evaluate the feasibility and safety of direct transcatheter aortic valve implantation (TAVI) by the transfemoral approach without balloon pre‐dilatation using the Edwards SapienXT valve.

Background

TAVI is established in selected high‐risk patients with severe aortic stenosis. Balloon aortic valvuloplasty (BAV) is recommended prior to valve implantation, but may contribute to procedural risk. It is unknown whether this is necessary for successful passage and deployment of the device.

Methods

81 patients (mean age 84 [95%CI:82–85.8], 62% male, median EuroScore 22.8% [95%CI:20.5–27]) undergoing transfemoral TAVI (35 by direct implantation [direct group]; 46 with balloon pre‐dilatation [balloon group]) between 2010 and 2013 were analyzed for efficacy and safety endpoints.

Results

Procedural success was 100%. Pre and post‐procedural peak gradients in the direct group were 66mmHg (95%CI:59–72.8) and 14mmHg (95%CI:12–17.8)(P < 0.0001) compared to 76.5mmHg (95%CI:73.7–94.0) and 17mmHg (95%CI:16–19)(P < 0.0001) in the balloon group. Post‐dilatation was performed in 4/35(11.4%) of the direct group and 3/46(6.5%) of the balloon group (P = 0.83). Post procedure moderate AR was present in 1/35(2.9%) in the direct group and none in the balloon group. In‐hospital mortality (2.9% direct vs. 0% balloon group), stroke (2.9% vs. 4.4%), tamponade (2.9% vs. 2.2%), major vascular complications (2.9% vs. 8.7%) and new permanent pacing (2.2% vs. 0) were similar. Pacing time, inflations, radiation dose and contrast use were all significantly lower in the direct group.

Conclusions

Direct implantation of the Edwards SapienXT valve during TAVI by the transfemoral route appears safe, efficacious and feasible in those without extreme calcification. © 2016 Wiley Periodicals, Inc.
Heterogeneous Catalytic Hydroarylation of Olefins at a Nanoscopic Aluminum Chlorofluoride
Authors: Calvo Beatriz , Wuttke Jan , Braun Thomas , Kemnitz Erhard
Published: May 2016

We report on hydroarylation reactions of arenes with olefins under very mild conditions catalyzed heterogeneously by aluminum chlorofluoride (ACF; AlClxF3−x, x≈0.05–0.25). The reactions of benzene and toluene with ethylene or propylene proceed with high conversions to afford various alkylated arenes. For cyclohexene and 1‐hexene, the reactions require higher temperatures and the conversions are lower. ACF also catalyzes the hydroarylation of 1,3,5‐trifluorobenzene and pentafluorobenzene with ethylene and propylene. The alkylations of arenes with non‐fluorinated olefins resemble typical Friedel–Crafts chemistry to give rise to Markovnikov regioselectivity. The reaction of CF3CH=CH2 with benzene proceeds with anti‐Markovnikov regioselectivity to give the fluorinated olefin PhCHCH=CF2 and the alkylation product PhCH2CH2CF3 as products of C−F and C−H activation.
Scanning Electrochemical Microscopy of Cytochrome c Peroxidase through the Orientation‐Controlled Immobilisation of Cytochrome c
Authors: Gunawan Christian A. , Nam Ekaterina V. , Marquis Christopher P. , Gooding J. Justin , Thordarson Pall , Zhao Chuan
Published: May 2016

Immobilisation of enzymes onto surfaces with defined orientation is of particular importance in order to optimise their activity and capacity to dock electron‐transfer partners. Local characterisation methods are thus crucial to understanding the activity–orientation relationship of immobilised enzymes for long‐term storage and applications. Herein, cytochrome c (cyt c) is chemoselectively immobilised through a cysteine functional group with a maleimide‐functionalised gold surface, thus controlling cyt c orientation. X‐ray photoelectron spectroscopy confirmed successful cyt c immobilisation. Scanning electrochemical microscopy methodologies were developed to quantify the activity of immobilised cyt c and cytochrome c peroxidase (CcP). The results suggest optimal enzymatic activities and docking ability for surface‐tethered cyt c are obtained through the cysteine–maleimide linkage, in comparison to conventional indiscriminate lysine–carboxyl linkages. This study reveals the strong influence of cyt c orientation, as a result of linking strategy, upon the docking ability of redox‐electron partner CcP.
A Hexakis Terpyridine‐Fullerene Ligand in Six‐Fold Ruthenium, Iridium, and Iron Complexes: Synthesis and Electrochemical Properties
Authors: Yan Weibo , Réthoré Céline , Menning Sebastian , Brenner‐Weiß Gerald , Muller Thierry , Pierrat Philippe , Bräse Stefan
Published: May 2016

An unprecedented straightforward route to six‐fold terpyridine ligands around C60, the latter being regioselectively functionalized in pseudo‐octahedral positions using a six‐fold Bingel reaction, is reported. Ruthenium, iridium, and iron complexes have been synthesized, and unambiguously characterized by NMR, MS, and cyclic voltammetry.
Photoinduced DNA Interstrand Cross‐Link Formation by Naphthalene Boronates via a Carbocation
Authors: Wang Yibin , Lin Zechao , Fan Heli , Peng Xiaohua
Published: May 2016

Most photoinduced DNA cross‐link formation by a bifunctional aryl derivative is through a bisquinone methide. DNA cross‐linking via a bisarylcarbocation remains a less explored area. We designed and synthesized a series of naphthalene boronates that produce DNA interstrand cross‐links via a carbocation upon UV irradiation. A free radical was generated from the naphthalene boronates with 350 nm irradiation and further converted to a carbocation by electron transfer. The activation mechanism was determined using the orthogonal traps, 2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TEMPO) and methoxyamine that react with either the free radical or the carbocation but not both. This represents a novel example of photoinduced DNA cross‐link formation via carbocations generated from a bisaryl derivative. This work provides information useful for the design of novel photoactivated DNA cross‐linking agents.
Palladium‐Initiated Radical Cascade Stereoselective Iodofluoroalkylation/Cycloisomerization of Ene‐vinylidenecyclopropanes
Authors: Yang Song , Xu Qin , Shi Min
Published: May 2016

A novel and convenient palladium‐initiated radical cascade stereoselective iodofluoroalkylation/cycloisomerization of ene‐vinylidenecyclopropanes with fluoroalkyl iodides has been developed. The reaction proceeds under mild reaction conditions with high atom economy and stereoselectivity, thereby allowing an efficient access to a variety of difluoromethylated or perfluoroalkylated pyrrolidines tethered with an alkyl iodide. Two plausible radical pathways for the transformation have been proposed on the basis of the results of control experiments and previous reports, which in one case it was thought that palladium(0) was an initiator rather than a catalyst.
Concise Approach to (ent)‐14 β‐Hydroxysteroids through Highly Diastereo‐/Enantioselective Diels–Alder Reactions
Authors: Peter Clovis , Ressault Blandine , Geoffroy Philippe , Miesch Michel
Published: May 2016

14β‐Hydroxysteroids, especially 14β‐hydroxyandrostane derivatives are closely related to the cardenolide skeletons. The latter were readily available through highly diastero/enantioselective Diels–Alder (DA) reactions requiring high pressure or Lewis acid activation. Moreover, in the presence of (R)‐ or (S)‐carvone as a chiral dienophile, the DA‐reaction takes place under chemodivergent parallel kinetic resolution control affording highly enantiomerically enriched 14β‐hydroxysteroid derivatives or the corresponding (ent)‐14β‐hydroxysteroid derivatives.
Catalytic Access to Alkyl Bromides, Chlorides and Iodides via Visible Light‐Promoted Decarboxylative Halogenation
Authors: Candish Lisa , Standley Eric A. , Gómez‐Suárez Adrián , Mukherjee Satobhisha , Glorius Frank
Published: May 2016

Herein is reported the catalytic, visible light‐promoted, decarboxylative halogenation (bromination, chlorination, and iodination) of aliphatic carboxylic acids. This operationally‐simple reaction tolerates a range of functional groups, proceeds at room temperature, and is redox neutral. By employing an iridium photocatalyst in concert with a halogen atom source, the use of stoichiometric metals such as silver, mercury, thallium, and lead can be circumvented. This reaction grants access to valuable synthetic building blocks from the large pool of cheap, readily available carboxylic acids.
ChemInform Abstract: Structural Studies of the Hydrogen Storage Material Mg2NiH4. Part 2. Monoclinic Low‐Temperature Structure.
Authors: ZOLLIKER P. , YVON K. , JORGENSEN J. D. , ROTELLA F. J.
Published: May 2016

The structure of low‐temp.
ChemInform Abstract: The Sequence Distribution of Aluminum(3+) and Titanium(3+) Ions in β‐Phase (TiCl3)(ACl3)0.33
Authors: BRANT P. , TORNQVIST E. G. M.
Published: May 2016

has been determined by magnetic methods sensitive to unpaired electrons (ESR, magnetic susceptibility measurements).
ChemInform Abstract: Absorption Spectrophotometric and X‐Ray Diffraction Studies of the Trichlorides of Berkelium‐249 and Californium‐249.
Authors: PETERSON J. R. , YOUNG J. P. , ENSOR D. D. , HAIRE R. G.
Published: May 2016

BkCl3 has been prepared for the first time in the PuBr3‐type orthorhombic modification by quenching from the melt.
ChemInform Abstract: Preparation of Cubic HZr2(PO4)3 and Related Compounds.
Authors: ONO A. , YAJIMA Y.
Published: May 2016

A single phase of cubic NH4Zr2(PO4)3 (I) with langbeinite‐type structure has been prepared at 235 °C by a hydrothermal method using mixtures of NH4H2PO4 and ZrOCl2·8 H2O as starting materials and NH4F as mineralizer.
ChemInform Abstract: Synthesis and Electrical Conductivity of a New Family of Pt Mixed Valence Complexes: Pt6(NH3)14Cl10X4 (X: ClO4, BF4, and PF6).
Authors: TANAKA M. , TSUJIKAWA I.
Published: May 2016

The title complexes have been prepared by partial oxidation (H2O2 or electrochemically) of the Magnus green salt, (Pt(NH3)4) (PtCl4) (I), in HClO4, HBF4, or HPF6 solution.
ChemInform Abstract: (R)‐2‐Isopropenylcyclopropane‐1,1‐dicarboxylic Acid: Absolute Configuration and Stereospecific Ring Expansion of Its Dimethyl Ester.
Authors: QUINKERT G. , SCHMALZ H.‐G. , WALZER E. , GROSS S. , DUERNER G. + , BATS J. W.
Published: May 2016

The synthesis of the title acid (VI) starts from the reaction of the alcohol (I) with the diacid (II) via cyclization to the cyclopropane derivative (V) as shown in the scheme.
ChemInform Abstract: (2.3)Wittig Rearrangement‐Peterson Olefination Sequence: A Stereocontrolled Approach to Conjugated Dienynes.
Authors: MIKAMI K. , MAEDA T. , NAKAI T.
Published: May 2016

When treated with butyl lithium the bissilylated unsaturated ethers (I) rearrange to form the carbinols (II).
ChemInform Abstract: Synthesis and Photoinduced Electron‐Transfer Promoted Isomerization of 7,7‐Dimethyl‐trans‐bicyclo(4.1.0)hept‐3‐ene.
Authors: GASSMAN P. G. , MLINARIC‐MAJERSKI K.
Published: May 2016

As outlined in the reaction scheme, the trans‐bicycloheptene (V) is prepared from the dicarboxylic acid (Ia) via the sulfide (IIIa) and ring contraction of the chlorosulfone (IV).