bluuebunny/crossref_metadata_2025 huggingface dataset:
Copper‐Catalyzed Remote C(sp3)−H Trifluoromethylation of Carboxamides and Sulfonamides
Authors: Liu Zhonglin , Xiao Haiwen , Zhang Benxiang , Shen Haigen , Zhu Lin , Li Chaozhong
Published: January 2019

Reported herein is an unprecedented protocol for trifluoromethylation of unactivated aliphatic C(sp3)−H bonds. With Cu(OTf)2 as the catalyst, the reaction of N‐fluoro‐substituted carboxamides (or sulfonamides) with Zn(CF3)2 complexes provides the corresponding δ‐trifluoromethylated carboxamides (or sulfonamides) in satisfactory yields under mild reaction conditions. A radical mechanism involving 1,5‐hydrogen atom transfer of N‐radicals followed by CF3‐transfer from CuII−CF3 complexes to the thus formed alkyl radicals is proposed.
Artificial Mn4Ca Clusters with Exchangeable Solvent Molecules Mimicking the Oxygen‐Evolving Center in Photosynthesis
Authors: Chen Changhui , Chen Yang , Yao Ruoqing , Li Yanxi , Zhang Chunxi
Published: January 2019

The natural Mn4Ca cluster in photosystem II serves as a blueprint to develop artificial water‐splitting catalysts for the generation of solar fuel in artificial photosynthesis. Although significant advances have recently been achieved, it remains a great challenge to prepare robust artificial Mn4Ca clusters that precisely mimic the structure and function of the biological catalyst. Herein, we report the isolation and structural characterization of two Mn4CaO4 complexes with polar solvent molecules, acetonitrile or N,N‐dimethylformamide, which closely mimics the two water molecules on the calcium ion, as well as the oxidation states of the four manganese ions and the main geometric structure of the natural Mn4Ca cluster. These new artificial Mn4Ca complexes provide important chemical clues to understand the structure and mechanism of the biological system.
Positively Charged Nanoaggregates Based on Zwitterionic Pillar[5]arene that Combat Planktonic Bacteria and Disrupt Biofilms
Authors: Gao Lingyan , Li Mingjun , Ehrmann Svenja , Tu Zhaoxu , Haag Rainer
Published: January 2019

Bacterial biofilms are difficult to eradicate because they are less susceptible to antibiotics and more easily develop resistance. Therefore, there is an urgent need for new materials that can combat planktonic bacteria and disrupt established biofilms. To tackle this challenge, we design a multifunctional zwitterionic pillar[5]arene, which can self‐assemble into weakly positively charged nanoaggregates that exhibit antibacterial activity against Gram‐negative Escherichia coli (DH5α) and Gram‐positive Staphylococcus aureus (SH1000) bacterial strains in solution. In addition, the zwitterionic pillar[5]arene can efficiently disrupt pre‐existing Escherichia coli (DH5α) biofilms and kill the biofilm‐enclosed bacteria without rapid generation of resistance.
From Lead Iodide to a Radical Form Lead‐Iodide Superlattice: High Conductance Gain and Broader Band for Photoconductive Response
Authors: Wang Guan‐E , Xu Gang , Zhang Ning‐Ning , Yao Ming‐Shui , Wang Ming‐Sheng , Guo Guo‐Cong
Published: January 2019

Superlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials. The insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI2 semiconductor through a mild solution method yielded the first lead iodide superlattice, EtDAB⋅4PbI2 (EtDAB=tetraethylbenzidine), with radical and non‐radical forms. The non‐radical form has a non‐ionic structure that differs from the common ionic structures for inorganic–organic hybrid lead halides. The radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis → UV/Vis‐IR), than pure PbI2 and the non‐radical form of the superlattice.
On the Remarkable Role of the Nitrogen Ligand in the Gas‐Phase Redox Reaction of the N2O/CO Couple Catalyzed by [NbN]+
Authors: Sun Xiaoyan , Zhou Shaodong , Yue Lei , Guo Cheng , Schlangen Maria , Schwarz Helmut
Published: January 2019

The thermal gas‐phase catalytic reduction of N2O by CO, mediated by the transition‐metal nitride cluster ion [NbN]+, has been explored by using FT‐ICR mass spectrometry and complemented by high‐level quantum chemical calculations. In contrast to the [Nb]+/[NbO]+ and [NbO]+/[Nb(O)2]+ systems, in which the oxidation of [Nb]+ and [NbO]+ with N2O is facile, but in which neither [NbO]+ nor [Nb(O)2]+ react with CO at room temperature, the [NbN]+/[ONbN]+ system at ambient temperature mediates the catalytic oxidation of CO. The origins of the distinctly different reactivities upon nitrogen ligation are addressed by quantum chemical calculations.
Sigma‐1 Receptor Expression in DRG Neurons During a Carrageenan‐Provoked Inflammation
Authors: Jerčić Leo , Kostić Sandra , Vitlov Uljević Marija , Vukušić Pušić Tanja , Vukojević Katarina , Filipović Natalija
Published: January 2019

Sigma 1 receptor (σ1R) is a non‐opioid receptor that modulates pain perception and is strongly expressed in dorsal root ganglion (DRG) neurons. We studied the changes in the expression of σ1R in different sub‐populations of DRG neurons during the first 48 hr in a carrageenan‐induced inflammation rat model, with σ1R being a possible base for the development of neuropathic pain after inflammation. Twenty Sprague Dawley rats were divided into five groups (N = 4 in each group): the control (C) group was sacrificed immediately; all other animals received an intraplantar injection of 0.1 mL 2% carrageenan and were sacrificed in 6, 12, 24 or 48 hr after the injection and DRGs were collected and processed for immunohistochemistry. σ1R fluorescence intensity decreased slightly but significantly in up to 24 hr post‐carrageenan injection in all sub‐populations of DRG neurons (ib4+; ib4− medium, ib4− large and ib4− in total; P < 0.05 – P < 0.001), with the exception of the ib4− small neurons (<25 μm; P > 0.05). This decrement was followed by a subsequent increase in σ1R fluorescence intensity 48 hr after the plantar carrageenan injection (P < 0.05 – P < 0.0001). The same trend was also observed in the CGRP+ population of the DRG neurons, in the total population as well as in the CGRP+ small (<25 μm) and larger CGRP (>25 μm) sub‐populations (P < 0.05 – P < 0.001). The presented results may contribute to further understanding of role of σ1R in the development of peripheral sensitization during inflammation. They may also be valuable for the therapeutic application of σ1R antagonists, particularly in the adjustment of the antagonist's dosage in a particular time window. Anat Rec, 302:1620–1627, 2019. © 2019 American Association for Anatomy
Carbon Nanotube@N‐Doped Mesoporous Carbon Composite Material for Supercapacitor Electrodes
Authors: Fu Xinyu , Chen Aibing , Yu Yifeng , Hou Senlin , Liu Lei
Published: January 2019

Here, carbon nanotube@N‐doped mesoporous carbon (CNT@N‐PC) composites were synthesized by using resorcinol‐formaldehyde resin as carbon source, ionic liquids (ILs) as template, and nitrogen sources and tetraethyl orthosilicate (TEOS) as assistant agent. The use of ILs‐modified CNT with nitrogen and TEOS facilitated the generation of a richer mesoporous structure. The obtained CNT@N‐PC was composed of a CNT core and mesoporous carbon particles around it. CNT@N‐PC showed a 3D network structure like “dewy cobwebs” and had a high surface area of 857 m2 g−1, uniform pore size distribution (3.0 nm), and suitable N content (4.9 at.%). When used as supercapacitor electrode, the CNT@N‐PC exhibited a high specific capacitance (244 F g−1 at 1 A g−1), good rate capability and favorable capacitance retention (92.5 % capacitive retention after 5000 cycles), demonstrating the potential for application in high‐performance supercapacitors.
Numerical simulation of a strong tornado in eastern China with different microphysical schemes
Authors: Li Jingyuan , Ping Fan , Zhou Shunwu , Shen Xinyong
Published: January 2019

A tornado that occurred in eastern China on June 23, 2016 was simulated with the Weather Research and Forecasting (WRF) model (version 3.9) using three different microphysical schemes (WRF single‐moment 6‐class [WSM6] scheme, Morrison double‐moment scheme, and Milbrandt–Yau [MY] scheme). The results showed that the Morrison scheme's simulation result was the best among the three schemes. The Morrison scheme simulated a better structure of three layers, including a cold pool near the ground, thick heating layer in the middle levels, and cooling again above 14 km. From the microphysical processes, the possible formation mechanism was that the convective activity was first evoked by the near‐ground cold pool, and then the horizontal vortex tube was raised and vertically stretched before turning in the vertical direction by the release of latent heat caused by the water vapor condensation. Thereafter, the vortex tube was cut off by the downward movement caused by the cloud water evaporation and the snow melting in the front of the convection system, causing the violent vertical lift of the rear vortex tube, forming the tornado.
Fabrication of Remarkably Bright QD Densely‐Embedded Silica Nanoparticle
Authors: Ha Yuna , Jung Heung Su , Jeong Sinyoung , Kim Hyung‐Mo , Kim Tae Han , Cha Myeong Geun , Kang Eun Ji , Pham Xuan‐Hung , Jeong Dae Hong , Jun Bong‐Hyun
Published: January 2019

We developed a synthesis method for silica‐coated quantum dot (QD)‐densely‐embedded silica nanoparticle (Si@D‐QD@Si NP) with remarkably brighter fluorescence by increasing the number of QDs on silica NPs. Si@D‐QD@Si NPs exhibited a narrow size distribution and a high signal reproducibility. Red, green, and blue Si@D‐QD@Si NPs were successfully fabricated and characterized. The Si@D‐QD@Si NP carried 2.4 times more QDs than previously reported silica‐coated QD‐embedded silica NP (Si@QD@Si NP). The quantum yield of Si@D‐QD@Si NPs was slightly higher than Si@QD@Si NPs. The red Si@D‐QD@Si NPs showed approximately 26.6%, the green Si@D‐QD@Si NP 36.2%, and the blue Si@D‐QD@Si NP 39.3% higher fluorescence intensity compared to the corresponding Si@QD@Si NPs. This result implied that the particles can be used at bio‐field with a higher sensitive detection.
Characterization and Photoluminescence Property of a New Eu3+‐doped Phosphor of the K2[Al(B5O10)] Prepared by Precursor Method
Authors: Wu Xinchun , Li Ping , Ju Aizhong , Kang Jie , Zhang Yongfeng , Yao De
Published: January 2019

A new phosphor of the K2[Al(B5O10)]:Eu3+ was prepared by annealing of the as‐prepared of the precursor of K2[Al(B5O10)]∙4H2O:Eu3+ at 300–400 °C, and which has been synthesized under facile hydrothermal conditions. All the samples were characterized by the EDS, XRD, FT‐IR, and SEM. A systematic study on their luminescent properties has been performed by the PL and PLE. A series of influencing factors on the luminescent properties were also investigated. The PL and PLE studies reveal that the phosphor of K2[Al(B5O10)]:Eu3+ with optimal luminescent intensity and higher red‐orange ratio were obtained by sintering the precursor at 400 °C for 5.5 h, with 9% doping concentration, which suggests that it might as a potential application of the light display systems.
B‐Doped Fe/N/C Porous Catalyst for High‐Performance Oxygen Reduction in Anion‐Exchange Membrane Fuel Cells
Authors: Zhao Ye‐Min , Liao Li‐Mei , Yu Guo‐Qiang , Wei Ping‐Jie , Liu Jin‐Gang
Published: January 2019

The development of high‐performance non‐precious metal catalysts for the oxygen reduction reaction (ORR) as an alternative to platinum‐based counterparts in fuel cells is highly desirable but challenging. In this study, a facile approach for preparing a porous boron‐bearing Fe/N/C catalyst by pyrolysis was reported. The obtained FeCNB‐900 with a high surface area (784 m2 g−1) favored a 4e−‐reduction pathway for ORR, with a half‐wave potential of ∼0.86 V vs. RHE and high stability in 0.1 M KOH. Furthermore, anion‐exchange membrane fuel cells (AEMFCs) with the use of the FeCNB‐900 composite as the cathode catalyst exhibited a maximal power density of 0.172 W cm−2 without back pressure, revealing its promising potential for application in fuel cells and metal‐air batteries. Results demonstrated that the additional doping of B into Fe/N/C leads to a significant increase in the specific surface area of the catalyst composite and can adjust surface polarities as well as electronic properties and provide more active sites to impart a synergistic effect for boosting catalytic ORR performance.
Mixing Time Scale Determination in Microchannels Using Reaction Calorimetry
Authors: Reichmann Felix , Vennemann Kai , Frede Timothy Aljoscha , Kockmann Norbert
Published: January 2019

Mixing time scales are derived from heat flux profiles for an instantaneous and exothermic reaction in a commercially available microreactor. A continuous reaction calorimeter, based on numerous heat flux sensors, is used to record spatially resolved heat flux profiles in steady state. Total volumetric flow rate is varied at constant flow rate ratio and the region of main reaction progress is shifted within the microreactor according to the advancement of the mixing process. Secondary flow patterns, induced by Dean mixing elements within the microchannel at higher flow rates, enhance the mixing. Results display a decrease in mixing time at increased flow rates and energy dissipation rate. Additionally, the passive micromixer is evaluated regarding its efficiency.
Three‐Dimensional Assembly of Iron Phosphide Nanosheets: Synthesis and Enhanced Catalytic Activity for Hydrogen Evolution Reaction
Authors: Wang Min , Zhao Rupeng , Li Xingyun , Zhao Xiusong , Jiang Luhua
Published: January 2019

Iron phosphides show promising but limited activity as hydrogen evolution reaction (HER) catalysts due to the low number of active sites and poor electroconductivity. Herein, iron phosphide nanosheets were synthesized and assembled to three‐dimensional structures for the first time via a physical‐vapor‐infiltration assisted hard template strategy. The 3D structured FePx nanosheet assembly exhibits excellent electrocatalytic performance for hydrogen evolution reaction over a wide pH range, outperforming most of the FePx catalysts reported to date in activity and exhibiting superior stability to the commercial Pt/C catalyst. Spectroscopic analyses and electrochemical results support that the fast electron transfer, increased active sites and expedited mass transport, due to the 3D structure of the FePx nanosheets, boost the HER performance.
The MicroRNA, miR‐18a, Regulates NeuroD and Photoreceptor Differentiation in the Retina of Zebrafish
Authors: Taylor Scott M. , Giuffre Emily , Moseley Patience , Hitchcock Peter F.
Published: January 2019

During embryonic retinal development, six types of retinal neurons are generated from multipotent progenitors in a strict spatiotemporal pattern. This pattern requires cell cycle exit (i.e. neurogenesis) and differentiation to be precisely regulated in a lineage‐specific manner. In zebrafish, the bHLH transcription factor NeuroD governs photoreceptor genesis through Notch signaling but also governs photoreceptor differentiation though distinct mechanisms that are currently unknown. Also unknown are the mechanisms that regulate NeuroD and the spatiotemporal pattern of photoreceptor development. Members of the miR‐17‐92 microRNA cluster regulate CNS neurogenesis, and a member of this cluster, miR‐18a, is predicted to target neuroD mRNA. The purpose of this study was to determine if, in the developing zebrafish retina, miR‐18a regulates NeuroD and if it plays a role in photoreceptor development. Quantitative RT‐PCR showed that, of the three miR‐18 family members (miR‐18a, b, and c), miR‐18a expression most closely parallels neuroD expression. Morpholino oligonucleotides and CRISPR/Cas9 gene editing were used for miR‐18a loss‐of‐function (LOF) and both resulted in larvae with more mature photoreceptors at 70 hpf without affecting cell proliferation. Western blot showed that miR‐18a LOF increases NeuroD protein levels and in vitro dual luciferase assay showed that miR‐18a directly interacts with the 3′ UTR of neuroD. Finally, tgif1 mutants have increased miR‐18a expression, less NeuroD protein and fewer mature photoreceptors, and the photoreceptor deficiency is rescued by miR‐18a knockdown. Together, these results show that, independent of neurogenesis, miR‐18a regulates the timing of photoreceptor differentiation and indicate that this occurs through post‐transcriptional regulation of NeuroD.
Insights into retinoic acid deficiency and the induction of craniofacial malformations and microcephaly in fetal alcohol spectrum disorder
Authors: Petrelli Berardino , Bendelac Liat , Hicks Geoffrey G. , Fainsod Abraham
Published: January 2019

Fetal Alcohol Spectrum Disorder (FASD) is a set of neurodevelopmental malformations caused by maternal consumption of alcohol during pregnancy. FASD sentinel facial features are unique to the disorder, and microcephaly is common in severe forms of FASD. Retinoic acid deficiency has been shown to cause craniofacial malformations and microcephaly in animal models reminiscent of those caused by prenatal alcohol exposure. Alcohol exposure affects the migration and survival of cranial neural crest cells, which are required for proper frontonasal prominence and pharyngeal arch development. Defects in craniofacial development are further amplified by the many downstream pathways that are transcriptionally controlled retinoic acid target genes, including Shh signaling. Recent evidence shows that alcohol exposure itself is sufficient to induce retinoic acid deficiency in the embryo. These data suggest that retinoic acid deficiency is an important underlying etiology of FASD. In disorders like Vitamin A Deficiency, FASD, DiGeorge (22q11.2 Deletion Syndrome), CHARGE, Smith‐Magenis, Matthew‐Wood, and Congenital Zika Syndromes, evidence is accumulating to link reduced retinoic acid signaling with developmental defects like craniofacial malformations and microcephaly. Research focus on characterizing the effects of retinoic acid deficiency during early development and on understanding the downstream signaling pathways involved in aberrant head, and craniofacial development will reveal underlying etiologies of these disorders.
Recruitment tolerance to increased temperature present across multiple kelp clades
Authors: Muth Arley F. , Graham Michael H. , Lane Christopher E. , Harley Christopher D. G.
Published: January 2019

Kelp systems dominate nearshore marine environments in upwelling zones characterized by cold temperatures and high nutrients. Worldwide, kelp population persistence and recruitment success generally decreases with rising water temperatures coupled with low nutrients, making kelp populations vulnerable to impending warming of the oceans. This response to climate change at a global scale, however, may vary due to regional differences in temperature variability, acclimation, and differential responses of kelp species to changing conditions. Culture experiments were conducted on 12 eastern Pacific kelp taxa across geographic regions (British Columbia, central California, and southern California) under three nitrate levels (1, 5, and 10 μmol/L) and two temperatures (12°C and 18°C) to determine sporophyte production (i.e., recruitment success). For all taxa from all locations, sporophytes were always present in the 12°C treatment and when recruitment failure was observed, it always occurred at 18°C, regardless of nitrate level, indicating that temperature is the driving factor limiting recruitment, not nitrate. Rising ocean temperatures will undoubtedly cause recruitment failure for many kelp species; however, the ability of species to acclimatize or adapt to increased temperatures at the warmer edge of their species range may promote a resiliency of kelp systems to climate change at a global scale.
Predicting Biogasification Potential of Urban Wastewater Using Multiparameter Aggregated Index of Influent
Authors: Anaokar G. S. , Khambete A. K. , Christian R. A.
Published: January 2019

Municipal wastewater treatment plants have sufficient organic loading and can be utilized as reliable biogas generator. Prediction of biogasification potential is essential to maintain regularity in biogas supply and maximum utilization for energy recovery. Many attempts have been carried out to predict biogas using computational and logical models. Although due to uncertain characteristics of wastewater throughout the year, mathematical formulation of biogas found difficult. This research article has a novel approach to predict biogas using multi‐parameter aggregated index (MPAI), which has overcome the limitation of uneven characteristics. Indices for raw wastewater (MPAIinf) and digester feedstock (MPAIdig) were calculated. The correlation of biogas generation with R‐square value of 0.92 with MPAIinf and that of 0.87 for MPAIdig was found. A linear equation was established using the most significant parameter; BOD and these indices. Biogas prediction was found easy in all seasons with a precision of 93% when tested on site. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13119, 2019
Postlaryngectomy prosthetic voice rehabilitation outcomes in a consecutive cohort of 232 patients over a 13‐year period
Authors: Petersen Japke F. , Lansaat Liset , Timmermans Adriana J. , van der Noort Vincent , Hilgers Frans J. M. , van den Brekel Michiel W. M.
Published: January 2019

Background

With the increasing necessity for total laryngectomy (TL) after prior (chemo)radiotherapy, prosthetic vocal rehabilitation outcomes might have changed.

Methods

Retrospective cohort study including all patients laryngectomized between 2000 and 2012 with a voice prosthesis (VP) in the Netherlands Cancer Institute.

Results

Median device lifetimes of the standard Provox2 and Vega VPs are 63 and 66 days, respectively, and for the problem‐solving ActiValve Light and Strong VPs 143 and 186 days, respectively. In multivariable analysis, salvage TL and TL for a dysfunctional larynx (compared to primary TL) were associated with a shorter device lifetime. Almost half of the patients (48%) experienced tracheoesophageal puncture tract‐related problems, and this concerned 12% of all VP replacements.

Conclusions

Compared to historical cohorts, device lifetimes of regular Provox2 and Vega voice prostheses have decreased. Complications are not occurring more frequently but affect more patients. Nevertheless, the clinical reliability and validity of prosthetic voice rehabilitation is still sound.
Head and neck cancer PEG site metastases: Association with PEG placement method
Authors: Montes de Oca Mary K. , Nye Anthony , Porter Caroline , Collins Justin , Satterfield Corey , Schammel Christine M. G. , Trocha Steven D.
Published: January 2019

Background

Many patients with head and neck cancer (HNC) will require feeding tube placement for nutritional support using percutaneous endoscopic gastrostomy (PEG) tube. Rarely, HNC metastases have been reported at the PEG site, a morbidity associated with a poor outcome.

Methods

Along with a case report, an evaluation of PEG placement methods with metastases from the literature was completed along with a statistical analysis of the literature to determine PEG site metastases and method of placement correlations.

Results

The incidence of PEG metastases in patients with HNC with the “pull” method is statistically identical to that of patients receiving any other method for PEG placement.

Conclusions

When considering options for the placement of PEG tubes in patients with HNC, the “pull” method should not be considered as a technique which will put patients at risk for PEG site metastases more than any other method of placement.
Early Seroreversion After 2 Doses of Hepatitis A Vaccination in Human Immunodeficiency Virus–Positive Patients: Incidence and Associated Factors
Authors: Huang Sung‐Hsi , Huang Chung‐Hao , Wang Ning‐Chi , Chen Tun‐Chieh , Lee Yuan‐Ti , Lin Shih‐Ping , Lin Te‐Yu , Lin Chi‐Ying , Lee Yu‐Lin , Lee Chen‐Hsiang , Chen Cheng‐Pin , Lin Kuan‐Yin , Chen Guan‐Jhou , Liu Chun‐Eng , Cheng Shu‐Hsing , Lu Po‐Liang , Yang Chia‐Jui , Hung Chien‐Ching ,   on behalf of the Taiwan HIV Study Group
Published: January 2019

Serological responses (Seroresponse) and durability of hepatitis A virus (HAV) vaccination are reduced among human immunodeficiency virus (HIV)‐positive patients. Incidence of and associated factors with early seroreversion (loss of seroresponse) among HIV‐positive patients who have achieved seroresponses after two doses of HAV vaccination remain unclear. In this multicenter study, we followed HIV‐positive adults who had mounted seroresponses after completing two doses of HAV vaccination during a recent outbreak of acute hepatitis A between 2015 and 2017, a 1:4 case‐control study was conducted to identify factors associated with seroreversion. Case patients were those with seroreversion, and controls were those with similar follow‐up durations who were able to maintain seroresponses. During the study period, 49 of the 1,256 patients (3.9%) seroreverted after a median follow‐up of 611 days. In a case‐control study, seroreversion was more likely to occur in patients with a higher weight (adjusted odds ratio [aOR], 1.703; 95% confidence interval [CI], 1.292‐2.323, per 10‐kg increment) and HIV viremia at the time of vaccination (aOR, 2.922; 95% CI, 1.067‐7.924), whereas positive seroresponse at 6 months of HAV vaccination and higher CD4 lymphocyte counts at vaccination were inversely associated with early seroreversion with an aOR of 0.059 (95% CI, 0.020‐0.154) and 0.837 (95% CI, 0.704‐0.979, per 100‐cell/mm3 increment), respectively, in multivariable analyses. Conclusion: During an outbreak setting, early seroreversion following two‐dose HAV vaccination occurred in 3.9% of HIV‐positive patients. Lower and delayed seroresponses to HAV vaccination, a higher weight, and HIV viremia and lower CD4 lymphocyte counts at the time of HAV vaccination were associated with early seroreversion. Regular monitoring of seroresponse and booster vaccination might be warranted, especially in HIV‐positive adults with predictors of early seroreversion.
Visibility in community health work mediated by mobile health systems: A case of Malawi
Authors: Namatovu Esther , Kanjo Chipo
Published: January 2019

The paper explores how community health work becomes visible to different actors in the health system through a mobile health system. Community health work is confined in places of physical settings for many mobile and distributed workers. These places create social meanings and significance in which work is situated and yet blurry to the rest of the health system. An in‐depth interpretive case study of a mobile health system designed to support decision‐making in maternal and infant care for community health workers (CHWs) referred to as health surveillance assistants (HSAs) in Malawi showed how the system was implicated in work visibility. In our empirical findings, we uncover work aspects like work interactions, collaboration, coordination, surveillance among others that flow through place and space hence becoming visible to different actors. This visibility had implications for work coherence among colleagues, work identity affirmation and recognition in the community, and control from superiors. We contribute to ICT4D research by focusing on the micro perspective of work visibility, treating visibility as negotiated in work. We also make practical contributions by highlighting the implications of visibility and draw recommendations for system design to have intricate knowledge of work and other related dynamics in work.
Iterative Atomic Charge Partitioning of Valence Electron Density
Authors: Vyboishchikov Sergei F. , Voityuk Alexander A.
Published: January 2019

We propose an atomic charge partitioning scheme, iterative adjusted charge partitioning (I‐ACP), belonging to the stockholder family and based on partitioning of the valence molecular electron density. The method uses a Slater‐type weighting factor cAr2n–2exp(–αAr), where αA is a fixed parameter and cA is determined iteratively. The parameters αA were fitted for 17 main‐group elements. The I‐ACP scheme is shown to produce consistent, chemically meaningful atomic charges. Several stockholder‐type charge‐partitioning are compared. Extensive numerical tests demonstrate that in most cases, I‐ACP surpasses most other methods by reproducing more accurately molecular dipole moments. © 2018 Wiley Periodicals, Inc.
Determining butanol inhibition kinetics on the growth of Clostridium pasteurianum based on continuous operation and pulse substrate additions
Authors: Kalafatakis Stavros , Skiadas Ioannis V , Gavala Hariklia N
Published: January 2019

BACKGROUND

Clostridium pasteurianum is a well described strain for the conversion of glycerol into butanol. In general, cell growth kinetics depends on the type of glycerol used and the concentration of butanol in the fermentation broth. However, despite the numerous studies existing on the subject, there is limited information in the literature regarding growth inhibition kinetics due to the cytotoxic effect of butanol on cell growth. This can be attributed to the difficulty of growing cells at high butanol concentration which renders the determination of inhibition kinetics a rather challenging task.

RESULTS

During this study a new approach for the determination of butanol inhibition kinetics on the growth of C. pasteurianum was tested. Specifically, pulses of crude glycerol were applied when steady state was reached during continuous fermentation experiments with increasing butanol concentration in the feed. Combining pulse experiments with batch fermentation at low substrate concentration allowed for accurate determination of the kinetic constants for inhibited growth. This approach also minimized the correlation of the growth constants which often leads to poor identifiability.

CONCLUSION

The proposed experimental approach showed good identifiability of the kinetic parameters for butanol inhibition of the microbial growth and can be proven valuable for the determination of inhibitory effects of highly toxic compounds. © 2019 Society of Chemical Industry
On investigations of refractive indices and birefringence of fiber using duplicate and non‐duplicate micro‐interferograms of double refracting interferometer
Authors: El‐Morsy Mohamed A.
Published: January 2019

The formula of refractive index of fiber considering the refraction has been reviewed. This formula is used to investigate the effect of refraction on the accuracy of refractive index calculations with different simulated micro‐interferograms of duplicate interference fringes with different fringe shifts order. Also a more accurate formula to calculate the birefringence from the non‐duplicate interference fringes has been derived and tested to calculate the birefringence of simulated and experiment micro‐interferogram. The presented micro‐interferograms were automatically analyzed and the contour lines of the bright fringes were determined using Fourier transform technique. A prepared software program takes the contour line of the fringes and automatically calculate the refractive index, the radius, and the birefringence of fiber. A good result was obtained in case of using immersion liquid matches between the parallel and perpendicular refractive indices of fiber.

Formula of refractive index of fiber considering the refraction has been reviewed.

The refraction effect on the accuracy of refractive index calculations was presented.

More accurate Formula to calculate the birefringence of fiber was derived.

Automatic fringe analysis was done for duplicate and non‐duplicate fringes.

The contour line of the fringe used directly to calculate the birefringence of fiber.
Observed changes in precipitation extremes and effects of tropical cyclones in South China during 1955–2013
Authors: Wang Xinlu , Liu Shaw Chen , Liu Run , Shiu Chein‐Jung , He Chao , Zhong Xiang
Published: January 2019

Daily precipitation data from 21 Chinese Surface Stations for Global Exchange in South China and historical tracks of tropical cyclones (TCs) from International Best Track Archive for Climate Stewardship (IBTrACS) during 1955–2013 are analysed to study changes in extreme precipitation and TC‐related precipitation with respect to global mean temperature. On annual and seasonal bases, there have been significant enhancements in heavy precipitation and suppressions of light and moderate precipitation under global warming conditions. Except in winter, the enhancements in heavy precipitation dominate over the suppressions of light and moderate precipitation, leading to increases of seasonal total precipitation. A significant increase of consecutive dry‐day episodes has been observed, especially in winter and early spring, which is detrimental to spring planting. The top 10% heavy precipitation associated with TCs has increased significantly under global warming conditions, despite a reduction in TC frequency. Finally, we find that TC‐related precipitation per TC storm in South China has increased by an alarming rate of about 50% during the period of 1955–2013.
Hydrological severity assessment of extreme climate conditions
Authors: Park Jongmin , Baik Jongjin , Choi Minha , Jeong Jaehwan , Sur Chanyang
Published: January 2019

The management of water resources is challenging under extreme climate conditions with the acceleration of climate change. Many existing indices for analysing extreme climate conditions focus on the statistical behaviour of a single hydrological variable, such as precipitation or temperature. Such indices have limitations in providing a comprehensive interpretations of elaborate extreme climate conditions. In this study, the hydrological severity index (HSI), which is defined as the ratio of precipitation to the sum of evapotranspiration, runoff, and terrestrial water storage from the water balance equation, was proposed and calculated using Global Land Data Assimilation System datasets for 1980–2010. Mean HSI was relatively high in tropical regions due to the high sensitivity of precipitation, while it was relatively low in semi‐arid and arid regions due to low precipitation and high evaporative demand. HSI showed a good representation of hydrological severity based on the spatial pattern of the absolute correlation coefficient as well as the opposite pattern of the coefficient of variation calculated from HSI and the radiative index of dryness. Based on the aforementioned phenomenon, temporal anomaly HSI (HSIanom) was applied to Pakistan and Australia as case studies to analyse the 2010 Pakistan Flooding and the Australian Millennium Drought (especially in 2002 and 2006). The HSIanom was able to capture the severity of extreme climate events and to provide underlying causes accompanying the physical climate forcing system. Specifically, the spatial pattern of HSIanom was useful for analysing regions with high severity to extreme climate conditions. The HSI can be used to establish water management policies that consider regional hydrological features in order to cope with intensified climate change. In addition, stand‐alone HSI could be used to predict future climate trends based on precise simulations of hydrological variables.
Novel contribution to clubfoot pathogenesis: The possible role of extracellular matrix proteins
Authors: Eckhardt Adam , Novotny Tomas , Doubkova Martina , Hronkova Lucia , Vajner Ludek , Pataridis Statis , Hadraba Daniel , Kulhava Lucie , Plencner Martin , Knitlova Jarmila , Liskova Jana , Uhlik Jiri , Zaloudikova Marie , Vondrasek David , Miksik Ivan , Ostadal Martin
Published: January 2019

Idiopathic pes equinovarus (clubfoot) is a congenital deformity of the feet and lower legs. Clubfoot belongs to a group of fibro‐proliferative disorders but its origin remains unknown. Our study aimed to achieve the first complex proteomic comparison of clubfoot contracted tissue of the foot (medial side; n = 16), with non‐contracted tissue (lateral side; n = 13). We used label‐free mass spectrometry quantification and immunohistochemistry. Seven proteins were observed to be significantly upregulated in the medial side (asporin, collagen type III, V, and VI, versican, tenascin‐C, and transforming growth factor beta induced protein) and four in the lateral side (collagen types XII and XIV, fibromodulin, and cartilage intermediate layer protein 2) of the clubfoot. Comparison of control samples from cadavers brought only two different protein concentrations (collagen types I and VI). We also revealed pathological calcification and intracellular positivity of transforming growth factor beta only in the contracted tissue of clubfoot. Most of the 11 differently expressed proteins are strongly related to the extracellular matrix architecture and we assume that they may play specific roles in the pathogenesis of this deformity. These proteins seem to be promising targets for future investigations and treatment of this disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Flattened‐Top Domical Droplet Formed by a Poly(pyrrole) Membrane
Authors: Kim Hyejeong , Kim Kiwoong , Lee Sang Joon
Published: January 2019

Polypyrrole (PPy) is a promising conductive polymer (CP) with electrical versatility, easy synthesis and functionalization, stability, and biocompatibility. Diverse architectures have been adopted to improve PPy performance, but the direct and precise patterning of various architectures remains challenging. Here, the unique formation of a PPy membrane on the air/water interface of a droplet solution containing ammonium persulfate and phytic acid is investigated. When a PPy thin film forms on the air/water interface, the top of the droplet rapidly flattens. The formation procedure and final structure of the PPy thin film are visualized and quantitatively investigated. Unlike the typical globular structure of PPy, the self‐assembled PPy film surface fabricated in this study is very organized and regularly shaped. This well‐ordered membrane may have a very high buckling strength greater than the surface tension of the solution. The proposed precise fabrication method is simple and inexpensive for fabricating patterned functional membranes. These results provide new insight into the fabrication of CP and their applications in various practical electromaterial engineering fields.
Dissecting the performance of YouTube video streaming in mobile networks
Authors: Schwind Anika , Midoglu Cise , Alay Özgü , Griwodz Carsten , Wamser Florian
Published: January 2019

Video streaming applications constitute a significant portion of the Internet traffic today, with mobile accounting for more than half of the online video views. The high share of video in the current Internet traffic mix has prompted many studies that examine video streaming through measurements. However, streaming performance depends on many different factors at different layers of the TCP/IP stack. For example, browser selection at the application layer or the choice of protocol in transport layer can have significant impact on the video performance. Furthermore, video performance heavily depends on the underlying network conditions (eg, network and link layers). For mobile networks, the conditions vary significantly, since each operator has a different deployment strategy and configuration. In this paper, we focus on YouTube and carry out a comprehensive study investigating the influence of different factors on streaming performance. Leveraging the Measuring Mobile Broadband Networks in Europe (MONROE) test bed that enables experimentation with 13 different network configurations in four countries, we collect more than 1800 measurement samples in operational mobile networks. With this campaign, our goal is to quantify the impact of parameters from different layers on YouTube's streaming quality of experience (QoE). More specifically, we analyze the role of the browser (eg, Firefox and Chrome), the impact of transport protocol (eg, TCP or QUIC), the influence of network bandwidth, and signal coverage on streaming QoE. Our analysis reveals that all these parameters need to be taken into account jointly for network management practices, in order to ensure a high end‐user experience.
State‐of‐the‐Art and Trends in Synthesis, Properties, and Application of Quantum Dots‐Based Nanomaterials
Authors: Alizadeh‐Ghodsi Mohammadreza , Pourhassan‐Moghaddam Mohammad , Zavari‐Nematabad Ali , Walker Brian , Annabi Nasim , Akbarzadeh Abolfazl
Published: January 2019

Quantum dots (QDs) with a nanoscale size range have attracted significant attention in various areas of nanotechnology due to their unique properties. Different strategies for the synthesis of QD nanoparticles are reported in which various factors, such as size, impurities, shape, and crystallinity, affect the QDs fundamental properties. Consequently, to obtain QDs with appropriate physical properties, it is required to select a synthesis method which allows enough control over the surface chemistry of QDs through fine‐tuning of the synthesis parameters. Moreover, QDs nanocrystals are recently used in multidisciplinary research integrated with biological interfaces. The state‐of‐the‐art methods for synthesizing QDs and bioconjugation strategies to provide insight into various applications of these nanomaterials are discussed herein.
Relationship between Detrapping of Electrons and Negative Gate Bias during Recovery Process in a‐InGaZnO Thin Film Transistors
Authors: Kang Yun‐Seong , Lee Yeol‐Hyeong , Kim Woo‐Sic , Cho Yong‐Jung , Park JeongKi , Kim GeonTae , Kim Ohyun
Published: January 2019

The relationship between detrapping of electrons and negative gate bias in amorphous InGaZnO thin film transistors (a‐IGZO TFTs) is investigated. In these devices, positive gate‐bias stress (PBS) traps electrons at the gate insulator (GI) or at the interface between the channel and the GI, and creates acceptor‐like states, which the authors speculate may be oxygen interstitials or zinc vacancies. In contrast, negative gate‐bias stress (NBS) increases donor‐like states, which are speculated as ionized oxygen vacancies, near the interface. When subsequent negative gate bias (SNB) is applied to a TFT after PBS, electrons are detrapped and donor‐like states are increased simultaneously. Measurements with various SNB and PBS conditions suggests that SNB accelerates detrapping of electrons, and that those detrapped electrons interrupts the increase of donor‐like states.
Unexpected Oxidation Reaction of 1,6‐Diarylpyrene withCu(BF4)2⋅nH2O Affording Pyrenequinones
Authors: Yamashita Ken‐ichi , Nishimoto Kazuaki , Sugiura Ken‐ichi
Published: January 2019

The oxidation reactions of 1,6‐diarylpyrene 1 with Cu(BF4)2⋅nH2O were systematically studied, the aim of which was to obtain structurally well‐defined 1,6‐pyrenylenes. In marked contrast to the behaviors of the parent molecule and the previously studied molecule, pyrene and 2‐alkylpyrene, respectively, no oligomeric product was detected and instead, three highly colored products, A, B, and C were formed. Spectroscopic and preliminary diffraction studies revealed these products to be the derivatives of 1,6‐pyrenequinone (16PQ), 18PQ, and furan annulated 16PQ, respectively. A is the normal product of the oxidation reaction of 1. B has an abnormal rearrangement of one aryl group. C is formed from B by the intramolecular ring closing reaction of the aryl group. A reaction mechanism was proposed with consideration given to the stabilization of the cation radical intermediates by the aryl groups.
Recent Advances of Ternary Layered Cu2MX4 (M = Mo, W; X = S, Se) Nanomaterials for Photocatalysis
Authors: Lin Yunxiang , Chen Shuangming , Zhang Ke , Song Li
Published: January 2019

Photocatalytic technologies, based on efficient light absorption and conversion, have emerged as a viable solution to overcome the problems related to energy and the environment. Development of new cost‐effective materials coupled with the green synthesis routes in order to replace the noble metal‐based catalysts is critical to overcoming this challenge. In this review, a brief summary of the recent progress in ternary layered Cu2MX4 (M = Mo, W; X = S, Se) nanomaterials and their photocatalytic performance is presented. First, the structural configurations with different phases and crystallinity are described, as well as various experimental synthesis methods of Cu2MX4 nanomaterials. Thereafter, the effect of morphology modulation, facet selection, and multicomponent hybridization on the catalytic activity of Cu2MX4 is elucidated. In addition, a proposal for highly‐efficient Cu2MX4 photocatalysts is presented via rational designing strategies for realizing their specific applications in the fields of photodegradating organic pollutants, water splitting, and other photocatalytic reactions. Finally, the existing research challenges related to ternary Cu2MX4 layers along with future prospects are discussed in detail.
Challenges and solutions: An analysis of community‐reported needs of AZA collaboratively managed animal populations
Authors: Wilson Lauren , Dorsey Candice , Moore Donald
Published: January 2019

Zoos and aquariums accredited by the Association of Zoos and Aquariums (AZA) cooperatively manage Species Survival Plan(R) (SSP) Program populations to maximize genetic and demographic health and work toward long‐term population sustainability. However, recent analyses suggest that only a minority of populations were projected to maintain their sustainability goals over 100 years. As one of the initial steps in addressing this concern, the AZA collaborated with hundreds of members of the zoo and aquarium community to develop the SSP Sustainability Database, a repository of quantitative and qualitative data on SSP Program challenges, population data, and management needs. A goal of this initiative was to identify the most critical needs across taxa and provide AZA‐accredited facilities a mechanism to align institutional resources with SSP Program priorities, thus facilitating strategic decision‐making for population sustainability at all levels of population management. Four types of critical SSP population needs emerged as the most common: additional spaces, optimized and standardized husbandry practices, the incorporation of new individuals into the population (importation), and improved breeding and transfer recommendation fulfillment. Patterns and trends in these critical needs varied across taxa and ex situ extinction risk (proxied by population management designation). The AZA community can apply these findings and proactively engage in opportunities to enhance SSP Program population sustainability through strategic, collaborative group action.