bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymph node metastasis in lung squamous cell carcinoma and identification of metastasis‐related genes based on the Cancer Genome Atlas
Authors: Dong Ming , Gong Hao , Li Tong , Li Xin , Liu Jinghao , Zhang Hongbing , Liu Minghui , Chen Gang , Liu Hongyu , Chen Jun
Published: September 2019

Squamous cell carcinoma (SCC) is a unique clinical and histological category that accounts for about 30% of total lung cancer. To identify risk factors for lymph node metastasis and analyze the molecular features of these metastases in lung SCC, a retrospective study was performed for 170 lung SCC patients who underwent surgical treatment. The overall survival of these patients with or without lymph node metastasis (LM/NLM) was analyzed using the Kaplan‐Meier method. We also used the TCGA database to compare the differentially expressed genes (DEGs) in patients with stage T1‐2 and T3‐4 lung SCC. Data from both our retrospective study and the TCGA database demonstrated a correlation between age and stage T1‐T2 LM (P = .002). There were significant differences between the LM and NLM groups in both mean survival time and median survival time for different T‐stages (P = .031). There were 176 upregulated and 177 downregulated DEGs between the LM and NLM groups in the stage T1‐2 group and 93 upregulated and 34 downregulated DEGs in the stage T3‐T4 group. These differentially expressed genes were predicted to participate in five cellular components, five molecular functions, and five biological processes. There were 20 genes, including GCG, CASR, NPY, CGA, TAC1, ALB, APOA1, CRH, CHRH, TRH, and GHSR, located at the core of the protein‐protein interaction network in the stage T1‐2 group and 11 genes, including F2, CASR, GRM1, GNRHR, GRPR, NTSR1, PROKR2, UTS2D, PTH, ALB, and FGA, in the stage T3‐4 group. Overall, LM plays a key role in the treatment response and prognosis of SCC patients. Several risk factors, including age and stage, were identified for LM. There was a previously undiscovered enrichment of significant novel genes in lung SCC between the LM and NLM groups, which may have the potential for predicting prognosis and targeting.
Cultures of Care in Primary Schools in Ireland that Support Child Protection Work
Authors: Nohilly Margaret
Published: September 2019

This paper presents the results of a qualitative study completed with 16 designated liaison persons (DLPs) for child protection in Ireland. The care practices and systems in place in Irish primary schools that support child protection work are the particular focus of this paper. Recent changes in legislation, following the publication of the Children First Act 2015 (Government of Ireland, Irish Statute Book; Office of the Attorney General), are considered. The Act recognises all teachers registered with the Teaching Council as mandated persons. Mandated persons are recognised as persons who work with children and young people and are required to report child abuse, above a defined threshold, which comes to their attention in the course of their professional or employment duties. Semi‐structured interviews were completed with the DLPs, and an exploratory approach using interpretative phenomenologial analysis was deemed the most suitable method of analysis for the study. Five superordinate themes emerged from the findings, alongside a number of subordinate themes; the theme ‘The School Story’ which focuses on the care practices that are undertaken in schools daily is illuminated throughout this paper. The findings highlight the need for formal acknowledgement of this work in schools and also for greater interagency communication and collaboration in the area of child protection.

‘This paper presents the results of a qualitative study completed with 16 designated liaison persons (DLPs) for child protection in Ireland’

Key Practitioner Messages

Teachers, in their day‐to‐day work in schools and through the care structures in place in schools, contribute in a significant way to the safety and protection of children.

There is a need for greater communication and collaboration between schools and the Child and Family Agency to support children at risk of abuse effectively.

There should be formal recognition in the evaluations undertaken by the Department of Education of the care practices that exist in schools.
Recent Advances of Natural Polyphenols Activators for Keap1‐Nrf2 Signaling Pathway
Authors: Zhou Yanping , Jiang Zhongliang , Lu Haiying , Xu Zhuyu , Tong Rongsheng , Shi Jianyou , Jia Guiqing
Published: September 2019

The Keap1‐Nrf2/ARE signaling pathway is an important defense system against exogenous and endogenous oxidative stress injury. The dysregulation of the signaling pathway is associated with many diseases, such as cancer, diabetes, and respiratory diseases. Over the years, a wide range of natural products has provided sufficient resources for the discovery of potential therapeutic drugs. Among them, polyphenols possess Nrf2 activation, not only inhibit the production of ROS, inhibit Keap1‐Nrf2 protein–protein interaction, but also degrade Keap1 and regulate the Nrf2 related pathway. In fact, with the continuous improvement of natural polyphenols separation and purification technology and further studies on the Keap1‐Nrf2 molecular mechanism, more and more natural polyphenols monomer components of Nrf2 activators have been gradually discovered. In this view, we summarize the research status of natural polyphenols that have been found with apparent Nrf2 activation and their action modes. On the whole, this review may guide the design of novel Keap1‐Nrf2 activator.
Probing the Membrane Vibration of Single Living Cells by Using Nanopipettes
Authors: Chen Bin‐Bin , Lv Jian , Wang Xiao‐Yuan , Qian Ruo‐Can
Published: September 2019

The vibration of a cell membrane plays a key role in the regulation of cell shape and the behavior of cells. However, most existing approaches for the measurement of cell vibration require either exogenous modification or sophisticated techniques, and the main challenge lies in developing methods that can monitor membrane vibration of living cells directly. Herein, a noninvasive strategy based on ultrasmall quartz nanopipettes is introduced. With a tip size of less than 100 nm, nanopipettes can be spatially controlled for precision targeting of a specific location on the membrane of single living cells. Surprisingly, by employing a constant voltage, stable cyclic oscillations are observed from the continuous current versus time traces. The time‐domain current can be decomposed into two basic waves: the high‐frequency one indicates the local membrane vibration driven by the electro‐osmotic flow from the nanopipette, whereas the low‐frequency one indicates the natural frequency of the whole cell. This provides a simple but reliable method to test local and global membrane vibration of single living cells simultaneously with little damage, which provides a tool for the quantification of drugs, disease, or mutations of the cell structure.
Enhanced Charge Transfer Process in Morphology Restructured TiO2 Nanotubes via Hydrochloric Acid Assisted One Step In‐Situ Hydrothermal Approach
Authors: Woo An Gil , Dhandole Love Kumar , Park Hyunwoong , Sub Bae Ho , Mahadik Mahadeo A. , Suk Jang Jum
Published: September 2019

In this study, we demonstrate the enhanced photoelectrochemical (PEC) performance of the titanium foil based TiO2 nanotube (TNT) array through a simple hydrothermal (HT) acid treatment method. The influence of hydrochloric acid (HCl) concentration variation in HT method on morphology and the photoelectrochemical performances of TNTs nanostructures were studied. Field Emission Scanning Electron Microscopy and X‐ray powder diffraction results confirmed the morphology and crystal structure easily restructured during HCl assisted one step in‐situ hydrothermal approach. The photocurrent density of optimized acid treated TiO2 nanotube (TH‐40) electrode was observed to be 2‐times higher than the pristine TNT electrode. Thereafter, TH‐40 sample exhibited noticeably photoelectrochemical solar hydrogen production of 66 μmol and 82 μmol in NaOH and Na2S/Na2SO3 electrolytes respectively than the pristine TNT. The enhancement of photocatalytic activity was ascribed to the restructured morphology, as well as the efficient charge separation at rutile‐anatase interface in the TH‐40 sample as well as at the electrode‐electrolyte interface. A hydrochloric acid assisted one step in‐situ hydrothermal approach tailors the crystal structure and morphological features, which enhanced the photoelectrochemical properties of TiO2 nanotube.
G‐Quadruplex‐Based Photooxidase Driven by Visible Light
Authors: Gao Longlong , Tong Xingyu , Ye Ting , Gao Heng , Zhang Qingqing , Yan Chenxiao , Yu Yali , Fei Yifan , Zhou Xiaoshun , Shao Yong
Published: September 2019

The G‐quadruplex (G4)/hemin entity has been widely used as a peroxidase‐mimic DNAzyme to catalyze the substrate oxidation with exogenous and concentrated H2O2 as oxidant for developing various devices. Herein, a G4‐based oxidase‐mimic DNAzyme that can be driven by visible light was developed. The oxidant is in situ produced by light irradiation. As a natural photosensitizer, Hypericin (Hyp) alone in solution is inactive because of aggregation. However, the binding with G4 triggers the fluorescence emission and activates Hyp to produce singlet oxygen (1O2) by energy transfer to the dissolved oxygen. Therefore, the G4/Hyp entity can serve as a photooxidase via the 1O2 pathway to catalyze the substrate oxidation. Since the G4‐bound Hyp can be excited by almost the whole range of visible light, the photooxidase should cover a wide range of photocatalytic applications. Similar to the peroxidase‐mimic DNAzyme, the G4 sequence can regulate the photooxidase activity and metal ions can serve as efficient cofactors to activate the photooxidase capacity for an inactive G4 structure. This work provides an alternative to build a versatile G4‐based photooxidase with straightforward tunability of its activity.
Drug Syntheses Beyond the Rule of 5
Authors: Tyagi Mohit , Begnini Fabio , Poongavanam Vasanthanathan , Doak Bradley C. , Kihlberg Jan
Published: September 2019

Drugs in the chemical space beyond the rule of 5 (bRo5) can modulate targets with difficult binding sites while retaining cell permeability and oral absorption. Reviewing the syntheses of bRo5 drugs approved since 1990 highlights synthetic chemistry's contribution to drug discovery in this space. Initially, bRo5 drugs were mainly natural products and semi‐synthetic derivatives. Later, peptidomimetics and de novo designed compounds, that include up to seven chiral centres and macrocyclic rings became dominant. These drugs are prepared by total synthesis, sometimes by routes of more than 25 steps with stereocentres originating from the chiral pool, or being installed by chiral induction or enzymatic resolution. Interestingly, ring‐closing metathesis proved to be the method of choice for macrocyclisation in hepatitis C virus protease inhibitors. We conclude that structural simplification, planning of synthetic routes regarding incorporation of stereocentres and macrocyclisation, as well as incorporation of structural knowledge and consideration of chameleonic properties in design, should facilitate drug discovery in bRo5 space.
Photoinitiated Reactions of Haloperfluorocarbons with Gold(I) Organometallic Complexes: Perfluoroalkyl Gold(I) and Gold(III) Complexes
Authors: Portugués Alejandro , López‐García Inmaculada , Jiménez‐Bernad Javier , Bautista Delia , Gil‐Rubio Juan
Published: September 2019

The study of perfluoroalkyl metal complexes is key to understand and improve metal‐promoted perfluoroalkylation reactions. Herein, we report the synthesis of the first gold complexes with primary or secondary perfluoroalkyl ligands by photoinitiated reactions between AuI organometallic complexes and iodoperfluoroalkanes. Complexes of the types LAuRF (L=PPh3 or N,N‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene; RF=n‐C4F9, n‐C6F13, i‐C3F7, c‐C6F11) and [Au(RF)(Ar)I(PPh3)] (Ar=2,4,6‐trimethylphenyl) have been isolated and characterized. Alkynes RFC≡CR were formed by reaction of Ph3PAuC≡CR (R=Ph, nHex) with IRF (RF=n‐C4F9, i‐C3F7). According to the evidences obtained, this transformation undergoes through a photoinitiated radical mechanism. AuIII complexes [Au(n‐C4F9)(X)(Y)L] (X=Y=Cl, Br, I, Me; X=Me, Y=I) have been prepared or in situ generated, and their thermal or photochemical decomposition reactions have been studied.
Integrated Bismuth Oxide Ultrathin Nanosheets/Carbon Foam Electrode for Highly Selective and Energy‐Efficient Electrocatalytic Conversion of CO2 to HCOOH
Authors: Meng Fan‐Lu , Zhang Qi , Liu Kai‐Hua , Zhang Xin‐Bo
Published: September 2019

Electroreduction of CO2 into formic acid (HCOOH) is of particular interest as a hydrogen carrier and chemical feedstock. However, its conversion is limited by a high overpotential and low stability due to undesirable catalysts and electrode design. Herein, an integrated 3D bismuth oxide ultrathin nanosheets/carbon foam electrode is designed by a sponge effect and N‐atom anchor for energy‐efficient and selective electrocatalytic conversion of CO2 to HCOOH for the first time. Benefitting from the unique 3D array foam architecture for highly efficient mass transfer, and optimized exposed active sites, as confirmed by density functional theory calculations, the integrated electrode achieves high electrocatalytic performance, including superior partial current density and faradaic efficiency (up to 94.1 %) at a moderate overpotential as well as a high energy conversion efficiency of 60.3 % and long‐term durability.
Low‐Energy Electronic Excitations of N‐Substituted Heteroacene Molecules: Matrix Isolation Spectroscopy in Concert with Quantum‐Chemical Calculations
Authors: Thusek Jean , Hoffmann Marvin , Hübner Olaf , Tverskoy Olena , Bunz Uwe H. F. , Dreuw Andreas , Himmel Hans‐Jörg
Published: September 2019

N‐Heteropolycycles are attractive as materials in organic electronic devices. However, a detailed understanding of the low‐energy electronic excitation characteristics of these species is still lacking. In this work, the matrix isolation technique is applied to obtain high‐resolution absorbance spectra for a series of tetracene and core‐substituted N‐analogues. The experimental electronic excitation spectra obtained for matrix‐isolated molecules are then analysed with the help of quantum‐chemical calculations. Additional lower energy excitation bands in the spectrum of the core‐substituted N‐derivatives of tetracene could be explained in terms of intensity borrowing from dipole‐forbidden transitions due to Herzberg–Teller vibronic coupling. In the case of tetracene, evidence for the additional formation of London dimers (J aggregates) is found at higher tetracene concentrations in the matrix.
Turning DNA Binding Motifs into a Material for Flow Cells
Authors: Feldner Tobias , Wolfrum Manpreet , Richert Clemens
Published: September 2019

Nanoscale assemblies of DNA strands are readily designed and can be generated in a wide range of shapes and sizes. Turning them into solids that bind biomolecules reversibly, so that they can act as active material in flow cells, is a challenge. Among the biomolecular ligands, cofactors are of particular interest because they are often the most expensive reagents of biochemical transformations, for which controlled release and recycling are desirable. We have recently described DNA triplex motifs that bind adenine‐containing cofactors, such as NAD, FAD and ATP, reversibly with low micromolar affinity. We sought ways to convert the soluble DNA motifs into a macroporous solid for cofactor binding. While assemblies of linear and branched DNA motifs produced hydrogels with undesirable properties, long DNA triplexes treated with protamine gave materials suitable for flow cells. Using exchangeable cells in a flow system, thermally controlled loading and discharge were demonstrated. Employing a flow cell loaded with ATP, bioluminescence was induced through thermal release of the cofactor. The results show that materials generated from functional DNA structures can be successfully employed in macroscopic devices.
Generation and Reaction of Functional Alkyllithiums by Using Microreactors and Their Application to Heterotelechelic Polymer Synthesis
Authors: Nagaki Aiichiro , Yamashita Hiroki , Tsuchihashi Yuta , Hirose Katsuyuki , Takumi Masahiro , Yoshida Jun‐ichi
Published: September 2019

Invited for the cover of this issue is the group of Aiichiro Nagaki at Kyoto University. The image depicts the reaction in the flow microreactor reported in the paper. Read the full text of the article at 10.1002/chem.201902867.
Optimization of the Liquid Distributor in a Falling Film Evaporator by Means of Air‐Water Experiments
Authors: Drumm Christian , Hoffmann Dieter , Steffens Friedhelm
Published: September 2019

Air‐water experiments (cold‐flow experiments) were performed for the liquid distributor of an industrial falling film evaporator (FFE). The feed to the FFE is superheated and a flash evaporation occurs in the head of the FFE. The aim of the experiments was to investigate the vapor‐liquid flow in the head and the resulting liquid distribution to the evaporator tubes. Several different designs of the distributor were investigated and explanations for the performance losses of the real evaporator over time were found. Several measures were finally concluded and also implemented for the real FFE.
Inference for a change‐point problem under an OU setting with unequal and unknown volatilities
Authors: Chen Fuqi , Mamon Rogemar , Nkurunziza Sévérien
Published: September 2019

Abstract

An Ornstein–Uhlenbeck (OU) process is employed as a versatile model to capture the mean‐reverting and stochastic evolution of many variables in various fields of applications including finance and economics. Within the OU setting, we develop a new estimation method to determine the unknown change‐point location under the assumption that the volatilities before and after the change point in a time series are unequal. Our method hinges on the concept of a weighted least sum of squared errors approach and enhanced by a fusion of an iterative algorithm. The consistency of the change‐point estimator is established. This article highlights a numerical implementation on simulated and observed financial market data demonstrating the significant flexibility and accuracy of our proposed modelling and estimation method. The Canadian Journal of Statistics 48: 62–78; 2020 © 2019 Statistical Society of Canada
The effect of heparin infusion intensity on outcomes for bridging hospitalized patients with atrial fibrillation
Authors: Warden Bruce A. , Diep Calvin , Ran Ran , Thomas Matthew , Cigarroa Joaquin E.
Published: September 2019

Background

Perioperative bridging in atrial fibrillation (AF) is associated with low thromboembolic rates but high bleeding rates. Recent guidance cautions the practice of bridging except in high risk patients. However, the practice of bridging varies widely and little data exist regarding appropriate anticoagulation intensity when using intravenous unfractionated heparin (UFH).

Hypothesis

To determine if high intensity UFH infusion regimens are associated with increased bleeding rates compared to low intensity regimens for bridging patients with AF.

Methods

We conducted a single center retrospective cohort study of admitted patients with non‐valvular AF receiving UFH for ≥24 hours. UFH intensities were chosen at the providers' discretion. The primary endpoint was the rate of bleeding defined by the International Society on Thrombosis and Hemostasis during UFH infusion or within 24 hours of discontinuation. The secondary endpoint was a composite of cardiovascular events, arterial thromboembolism, venous thromboembolism, myocardial infarctions and death during UFH infusion.

Results

A total of 497 patients were included in this analysis. Warfarin was used in 82.1% and direct acting oral anticoagulants in 14.1% of patients. The rate of any bleed was higher among high intensity compared to low intensity UFH regimens (10.5% vs 4.9%, odds ratio = 2.29, 95% confidence interval = 1.07‐4.90). Major bleeding was significantly higher among high intensity compared to low intensity UFH regimens. There was no difference in composite thrombotic events or death.

Conclusions

Low intensity UFH infusions, targeting lower anticoagulation targets, were associated with decreased bleeding rates without a signal of increased thromboembolic events in hospitalized AF patients.
Real‐world outcomes of sipuleucel‐T treatment in PROCEED, a prospective registry of men with metastatic castration‐resistant prostate cancer
Authors: Higano Celestia S. , Armstrong Andrew J. , Sartor A. Oliver , Vogelzang Nicholas J. , Kantoff Philip W. , McLeod David G. , Pieczonka Christopher M. , Penson David F. , Shore Neal D. , Vacirca Jeffrey , Concepcion Raoul S. , Tutrone Ronald F. , Nordquist Luke T. , Quinn David I. , Kassabian Vahan , Scholz Mark C. , Harmon Matt , Tyler Robert C. , Chang Nancy N. , Tang Hong , Cooperberg Matthew R.
Published: September 2019

Background

The large registry, PROVENGE Registry for the Observation, Collection, and Evaluation of Experience Data (PROCEED)(NCT01306890), evaluated sipuleucel‐T immunotherapy for asymptomatic/minimally symptomatic metastatic castration‐resistant prostate cancer (mCRPC).

Methods

PROCEED enrolled patients with mCRPC receiving 3 biweekly sipuleucel‐T infusions. Assessments included overall survival (OS), serious adverse events (SAEs), cerebrovascular events (CVEs), and anticancer interventions (ACIs). Follow‐up was for ≥3 years or until death or study withdrawal.

Results

In 2011‐2017, 1976 patients were followed for 46.6 months (median). The median age was 72 years, and the baseline median prostate‐specific antigen level was 15.0 ng/mL; 86.7% were white, and 11.6% were African American. Among the patients, 1902 had 1 or more sipuleucel‐T infusions. The median OS was 30.7 months (95% confidence interval [CI], 28.6‐32.2 months). Known prognostic factors were independently associated with OS in a multivariable analysis. Among the 1255 patients who died, 964 (76.8%) died of prostate cancer (PC) progression. The median time from the first infusion to PC death was 42.7 months (95% CI, 39.4‐46.2 months). The incidence of sipuleucel‐T–related SAEs was 3.9%. The incidence of CVEs was 2.8%, and the rate per 100 person‐years was 1.2 (95% CI, 0.9‐1.6). The CVE incidence among 11,972 patients with mCRPC from the Surveillance, Epidemiology, and End Results–Medicare database was 2.8%; the rate per 100 person‐years was 1.5 (95% CI, 1.4‐1.7). One or more ACIs (abiraterone, enzalutamide, docetaxel, cabazitaxel, or radium 223) were received by 77.1% of the patients after sipuleucel‐T; 32.5% and 17.4% of the patients experienced 1‐ and 2‐year treatment‐free intervals, respectively.

Conclusions

PROCEED provides contemporary survival data for sipuleucel‐T–treated men in a real‐world setting of new life‐prolonging agents, which will be useful in discussing treatment options with patients and in powering future trials with sipuleucel‐T. The safety and tolerability of sipuleucel‐T in PROCEED were consistent with previous findings.
Numerical studies of hemodynamic alterations in pre‐ and post‐stenting cerebral aneurysms using a multiscale modeling
Authors: Yu Hongtao , Huang George P. , Yang Zifeng , Ludwig Bryan R.
Published: September 2019

The aim of this work was to use a multiscale modeling to study the influence of stent deployment, with generic stents, on flow distributions within the vascular network and the hemodynamic alterations within the cerebral aneurysms pre‐ and post‐stenting. To achieve this goal, two image‐based anatomical cerebral aneurysm models were reconstructed along with the respective aneurysms post‐stenting models after deploying a 16‐ or 24‐wire stent. The investigation results revealed that the stent may increase the local pressure resistance resulting in flow alterations. The hemodynamic parameters demonstrated stent placement can reduce the intra‐aneurysmal pressure, decrease wall shear stress (WSS) at the neck region, and increase blood turnover time for aneurysm case I (sidewall aneurysm). These findings are consistent with the trends of hemodynamic changes reported previously. However, aneurysm case II (bifurcation aneurysm) showed gradually increased intra‐aneurysmal pressure and the pressure at the neck region, decreased WSS over the sac surface, and enhanced flow vortices within the aneurysm. When simulating the hemodynamics of pre‐ and post‐stenting aneurysms for a patient using measured flow waveforms, the flow alteration induced by the stent deployment may affect the hemodynamic predictions for the post‐stenting aneurysm. Thus, the remeasurement of boundary conditions once the morphology of the aneurysm is deformed is needed in follow‐up studies with a focus on aneurysm growth and stent deployment.
Cell focal adhesion clustering leads to decreased and homogenized basal strains
Authors: Kohn Julie C. , Abdalrahman Tamer , Sack Kevin L. , Reinhart‐King Cynthia A. , Franz Thomas
Published: September 2019

The subendothelial matrix of the artery is a complex mechanical environment where endothelial cells respond to and affect changes upon the underlying substrate. Our recent work has demonstrated that endothelial cell strain heterogeneity increases on a more heterogeneous underlying subendothelial matrix, and these cells display increased focal adhesion presence on stiffer substrate areas. However, the impact of these grouped focal adhesions on endothelial cell strains has not been explored. Here, we use finite element modeling to investigate the effects of microscale stiffness heterogeneities and focal adhesion location and stiffness on endothelial cell strains. Shear stress applied to the apical cell layer demonstrated a minimal effect on cell strain values, while substrate stretch had a greater effect on cell strain in the cell‐substrate model. The addition of focal adhesions into the computational model (cell‐FA‐substrate model) predicted a decrease and homogenization of the cell strains. For simulations including focal adhesions, stiffer and more distributed adhesions caused increased and more heterogeneous endothelial cell strains. Overall, our data indicate that cells may group focal adhesions to minimize and homogenize their basal strains.
Can Nanoplastics Alter Cell Membranes?
Authors: Hollóczki Oldamur , Gehrke Sascha
Published: September 2019

Whilst the formation of plastic nanoparticles (nanoplastics) from plastic wastes has been unequivocally evidenced, little is known about the effects of these materials on living organisms at the subcellular or molecular levels. In the present contribution we show through molecular dynamics simulations that polyethylene nanoparticles dissolve in the hydrophobic core of lipid bilayers into a network of disentangled, single polymeric chains. The thereby induced structural and dynamic changes in the bilayer alter vital functions of the cell membrane, which if lacking a mechanism to decompose the polymer chains may result in the death of the cell.
A Brønsted Acidic Ionic Liquid as an Efficient and Selective Catalyst System for Bioderived High Molecular Weight Poly(ethylene 2,5‐furandicarboxylate)
Authors: Qu Xiao‐ling , Jiang Min , Wang Bing , Deng Jin , Wang Rui , Zhang Qiang , Zhou Guang‐yuan , Tang Jun
Published: September 2019

Green synthesis of bioderived high‐molecular‐weight poly(ethylene 2,5‐furandicarboxylate) (PEF) over metal‐free catalysts is a significant challenge. This study focuses on PEF prepared from ethylene glycol and 2,5‐furandicarboxylic acid (FDCA) through a direct esterification method with ecofriendly metal‐free ionic liquids (ILs) as catalysts. The catalytic activities of a series of imidazolium cations in the presence of various anions are systematically investigated and found to be mainly governed by the anions. Among the ILs studied, 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([C2MIM]BF4) is identified as the best catalyst, showing excellent catalytic activity, selectivity, and stability, even at low catalyst loadings (0.1 mol % w.r.t. FDCA). Optimization of the polymerization parameters enables [C2MIM]BF4‐catalyzed production of PEF with a high number‐average molecular weight (Mn=5.25×104 g mol−1). The relationship between Brønsted acidity and catalytic activity is also investigated and the results show that the trend in catalytic activity is in good agreement with that in Brønsted acidity, as determined by the Hammett method. Additionally, on the basis of experimental results and density functional theory calculations, an electrophilic activation mechanism induced by hydrogen bonds is proposed. This strategy of adjustable acidity and anion structure in ILs provides an opportunity to develop other ILs for bio‐based polyesters through green synthesis pathways.
An efficient full‐bridge resonant converter for light emitting diode (LED) application with simple current control
Authors: Ramakrishnareddy Ch Kasi , Porpandiselvi Shunmugam , Vishwanathan Neti
Published: September 2019

New power control is introduced in the full‐bridge dc‐dc converter to drive an LED lamp in this paper. LEDs are semiconductor devices that behave like a constant voltage load with low equivalent series resistance (ESR). Hence, they require precise control for current regulation. In the proposed driver, the LED lamp is driven by two voltage sources connected in series through a series resonant circuit. It processes the majority of lamp power through the full‐bridge diode rectifier and supplies small power through a center‐tapped rectifier. The LED lamp current is controlled at the selected operating current by using center‐tapped rectifier output voltage. In addition, pulse‐width modulation (PWM) dimming is implemented. The proposed topology features zero‐voltage switching (ZVS), regulation of lamp current, dimming operation, and high efficiency. The working principle, performance, and prototype validation are given for the proposed LED driver.
Decoding the origins and sources of clay minerals in the Upper Cretaceous Tununk Shale of south‐central Utah: Implications for the pursuit of climate and burial histories
Authors: Li Zhiyang , Schieber Juergen , Bish David
Published: September 2019

Clay minerals in fine‐grained marine sedimentary successions are most commonly considered to be detrital in origin and have been used extensively by geologists as indicators of palaeoclimate conditions in the hinterland. Most of these previous studies, however, were not designed to address in depth the potential effects of mixing clay minerals from multiple sources and the formation of authigenic clay minerals during early diagenesis on the ultimately observed clay mineral assemblages of fine‐grained marine sedimentary successions. Herein, clay minerals in shales and bentonites of the Tununk Shale Member in south‐central Utah were examined through integrated X‐ray diffraction and petrographic (scanning electron microscopy) analysis, to evaluate the various origins of clay minerals in this offshore mudstone succession. Clays in Tununk bentonites contain dominantly smectite (>80%) and a minor amount of kaolinite. Clays in Tununk shale samples consist dominantly of mixed‐layer illite/smectite with up to 45% illite‐like layers, small amounts of kaolinite and mica, and in places trace amounts of chlorite. Clay minerals in Tununk shale samples occur in the following three forms: (a) in clay‐dominated aggregates (i.e. smectite‐dominated altered volcanic rock fragments and illite/smectite‐dominated shale lithics); (b) in the fine‐grained matrix (mostly illite/smectite and minor amounts of mica and kaolinite); and (c) in intergranular and intragranular pore spaces (authigenic smectite, kaolinite and chlorite). Possible sources for the mixed‐layer illite/smectite in shales include (a) erosion of older smectite‐bearing mudstone successions and (b) weathering of volcanic rocks or volcanic debris that had been deposited on land. Most of the kaolinite and chlorite in the Tununk Shale were precipitated as pore‐filling cements, rather than having a terrigenous source (as weathering products). A comprehensive understanding of the multiple origins of clay minerals (e.g. terrigenous input, volcanic input, recycled sediments and diagenesis) in marine mudstone successions is critical when attempting to use clay mineral data for reconstructions of palaeoclimate and burial and thermal histories.
Mate fidelity in a polygamous shorebird, the snowy plover (Charadrius nivosus)
Authors: Halimubieke Naerhulan , Valdebenito José O. , Harding Philippa , Cruz‐López Medardo , Serrano‐Meneses Martín Alejandro , James Richard , Kupán Krisztina , Székely Tamás
Published: September 2019

Social monogamy has evolved multiple times and is particularly common in birds. However, it is not well understood why some species live in long‐lasting monogamous partnerships while others change mates between breeding attempts. Here, we investigate mate fidelity in a sequential polygamous shorebird, the snowy plover (Charadrius nivosus), a species in which both males and females may have several breeding attempts within a breeding season with the same or different mates. Using 6 years of data from a well‐monitored population in Bahía de Ceuta, Mexico, we investigated predictors and fitness implications of mate fidelity both within and between years. We show that in order to maximize reproductive success within a season, individuals divorce after successful nesting and re‐mate with the same partner after nest failure. Therefore, divorced plovers, counterintuitively, achieve higher reproductive success than individuals that retain their mate. We also show that different mating decisions between sexes predict different breeding dispersal patterns. Taken together, our findings imply that divorce is an adaptive strategy to improve reproductive success in a stochastic environment. Understanding mate fidelity is important for the evolution of monogamy and polygamy, and these mating behaviors have implications for reproductive success and population productivity.
Widespread hybridization in the introduced hog deer population of Victoria, Australia, and its implications for conservation
Authors: Hill Erin , Linacre Adrian , Toop Simon , Murphy Nicholas , Strugnell Jan
Published: September 2019

In Australia, many species have been introduced that have since undergone drastic declines in their native range. One species of note is the hog deer (Axis porcinus) which was introduced in the 1860s to Victoria, Australia, and has since become endangered in its native range throughout South‐East Asia. There is increased interest in using non‐native populations as a source for genetic rescue; however, considerations need to be made of the genetic suitability of the non‐native population. Three mitochondrial markers and two nuclear markers were sequenced to assess the genetic variation of the Victorian population of hog deer, which identified that the Victorian population has hybrid origins with the closely related chital (Axis axis), a species that is no longer present in the wild in Victoria. In addition, the mitochondrial D‐loop region within the Victorian hog deer is monomorphic, demonstrating that mitochondrial genetic diversity is very low within this population. This study is the first to report of long‐term persistence of hog deer and chital hybrids in a wild setting, and the continual survival of this population suggests that hybrids of these two species are fertile. Despite the newly discovered hybrid status in Victorian hog deer, this population may still be beneficial for future translocations within the native range. However, more in‐depth analysis of genetic diversity within the Victorian hog deer population and investigation of hybridization rates within the native range are necessary before translocations are attempted.
Iodocarbocyclization to Access Six‐ and Seven‐Membered Phosphacycles from Phosphoryl‐Linked Alkynes
Authors: Wu Di , Hu Chaopeng , Qiu Liqi , Duan Zheng , Mathey François
Published: September 2019

The iodocarbocyclization of the tethered alkyne is an important method for diverse family of cyclic molecules. Using the phosphoryl group as a new linker leads to the formation of α‐iodo‐substituted spiro‐conjugated phosphinoline and phosphepines, which were further transformed to π‐elongated derivatives and provided a phosphepine based aggregation‐induced emission (AIE) luminogen.
Energy Analysis of Physical Absorption and Chemical Absorption of CO2 in Ionic Liquids
Authors: Xie Yujiao , Liu Gang , Nie Haiwei , Yu Fangyong , Xing Xiaoxue , Cui Hongyou
Published: September 2019

CO2 solubility in ionic liquids (ILs) is measured extensively to develop IL‐based technology for CO2 capture. Herein, the choline‐ and acetate‐based ILs are selected as the studied physical and chemical absorbents for CO2 capture, respectively. The CO2 solubilities in choline‐ and acetate‐based ILs are thermodynamically modeled. The ILs consumed for CO2 absorption and the energy demands for the ILs regeneration are calculated and compared with those of the conventional imidazolium‐based ILs. The results show that the three choline‐based ILs are not energy saving in the pressure‐swing process. In the temperature‐swing process, the energy demand for CO2 absorption by using acetate‐based ILs reveals that the chemical absorption‐based ILs are the absorbent with lower energy demands compared with the physical absorption‐based ILs.
Polymer Amplification to Improve Performance and Stability toward Semitransparent Perovskite Solar Cells Fabrication
Authors: Nikbakht Hafez , Shalan Ahmed Esmail , Salado Manuel , Assadi Abbas , Boroojerdian Parviz , Kazim Samrana , Ahmad Shahzada
Published: September 2019

The performance of methylammonium lead triiodide (CH3NH3PbI3)‐based solar cells depends on the crystallization and controlled microstructure. Despite their high performance, long‐term stability is a paramount factor toward large area fabrication and potential industrialization. Herein, poly(vinylidene fluoride–trifluoro ethylene) (P(VDF‐TrFE)) is used as an additive into a low concentration–based perovskite precursor solution to control the crystallinity and microstructure. Perovskite layers of lower thicknesses are derived from low precursor concentration, however, they often suffer from severe voids and roughness. Introducing judicious quantities of P(VDF‐TrFE) improves the surface coverage and smoothness, as well as reduce the grain boundaries in the perovskite. An array of characterization techniques are used to probe the structural, microstructural, and spectroscopic properties. Impedance spectra suggest that the P(VDF‐TrFE) can improve the carrier lifetime and reduce the charge transfer resistance, which in turn allows improvment of photovoltaic performance. For an optimized concentration of P(VDF‐TrFE), the fabricated semitransparent solar cells yield a power conversion efficiency in excess of 10%, which supersedes pristine devices, along with improved stability. The device architecture and the fabrication technique provide an effective route to fabricate cost effective and visible‐light‐semitransparent perovskite solar cells.
Alternating consumption of β‐glucan and quercetin reduces mortality in mice with colorectal cancer
Authors: Qi Jiamei , Yu Juntong , Li Yuetong , Luo Jianming , Zhang Cheng , Ou Shiyi , Zhang Guangwen , Yang Xinquan , Peng Xichun
Published: September 2019

The current dietary recommendations for disease prevention and management are scarce and are not well supported. Beta‐glucan or quercetin in a diet can alleviate colorectal cancer (CRC) by regulating the gut microbiota and related genes, but the effects of alternating their consumption for routine ingestion during CRC occurrence remain unknown. This study investigated the effects of alternating the consumption of β‐glucan and quercetin for routine ingestion on CRC development in mice. The mortality rate, colonic length, inflammatory cytokines, gut microbiota, and colonic epithelial gene expression in healthy and CRC mice that consumed normal and alternate diets were compared and studied. The results showed that alternating the consumption of β‐glucan and quercetin (alternating among a β‐glucan diet, a normal diet and a normal diet that was supplemented with quercetin) alleviated colon damage and reduced the mortality rate in CRC mice, with a reduction in mortality of 12.5%. Alternating the consumption of β‐glucan and quercetin significantly decreased the TNF‐α level, increased the relative abundance of Parabacteroides, and downregulated three genes (Hmgcs2, Fabp2, and Gpt) that are associated with inflammation and cancer. Alternating the consumption of some bioactive compounds, such as β‐glucan and quercetin, in food can contribute to human health. This experiment provided some experimental evidence for the dietary recommendations for disease prevention and management.
Molecular and Silica‐Supported Mo and W d0 Imido‐Methoxybenzylidene Complexes: Structure and Metathesis Activity
Authors: Zhizhko Pavel A. , Toth Florian , Gordon Christopher P. , Chan Ka Wing , Liao Wei‐Chih , Mougel Victor , Copéret Christophe
Published: September 2019

5‐Coordinated methoxybenzylidene complexes M(=NAr)(=CH−C6H4−o‐OMe)(OtBuF3)2 (Ar=2,6‐iPr2C6H3; tBuF3=CMe2(CF3)) of Mo (1mMo) and W (1mW) were synthesized by cross‐metathesis from the corresponding neophylidene/neopentylidene precursors and o‐methoxystyrene. 1mMo and 1mW were grafted onto the surface of silica partially dehydroxylated at 700 °C to give well‐defined silica‐supported alkylidenes (≡SiO)M(=NAr)(=CH−C6H4−o‐OMe)(OtBuF3) (M=Mo (1Mo), W (1W)). Supported methoxybenzylidene complexes were tested in metathesis of cis‐4‐nonene, 1‐nonene, and ethyl oleate, and compared to their molecular precursors and supported classical analogs (≡SiO)M(=NAr)(=CHCMe2R)(OtBuF3) (M=Mo, R=Ph (2Mo), M=W, R=Me (2W)). Both grafted complexes 1Mo and 1W show significantly better performance as compared to their molecular precursors 1mMo and 1mW but are less efficient than the classical 4‐coordinated alkylidenes 2Mo and 2W. Noteworthy, both 1Mo and 1W can reach equilibrium conversion in metathesis of cis‐4‐nonene at catalyst loadings as low as 50 ppm.
Effects of rainfall intensity and compaction on water transport from opencast coal mine soils: An experimental study
Authors: Wang Fengjiao , Wang Jinman
Published: September 2019

The use of heavy machinery during opencast coal mining can result in soil compaction. Severe soil compaction has a negative impact on the transport of water and gas in the soil. In addition, rainfall intensity has traditionally been related to soil surface sealing affecting water transport. To assess the effects of rainfall intensity and compaction on water infiltration and surface runoff in an opencast coal mining area, the disturbed soils from the Antaibao opencast mine in Shanxi Province, China, were collected. Four soil columns with different bulk densities (i.e., 1.4 g cm‐3, 1.5 g cm‐3, 1.6 g cm‐3, and 1.7 g cm‐3) were designed, and each column received water five times at rainfall intensities of 23.12, 28.91, 38.54, 57.81, and 115.62 mm hr‐1. The total volume of runoff, the time to start runoff, and the volumetric water contents at the depths of 5 cm, 15 cm, 25 cm, 35 cm, 45 cm, 55 cm, and 65 cm were measured. Under the same soil bulk density, high rainfall intensity reduced infiltration, increased surface runoff, and decreased the magnitude of change in the volumetric water contents at different depths. Under the same rainfall intensity, the soil column with a high bulk density showed relatively low water infiltration. Treatments 3 (1.6 g cm‐3) and 4 (1.7 g cm‐3) had very small changes in volumetric water contents of the profiles even under a lower rainfall intensity. Severe soil compaction was highly prone to surface runoff after rainfall. Engineering and revegetation measures are available to improve compacted soil quality in dumps. Our results provide a theoretical basis for the management of land reclamation in opencast coal mine areas.
Two‐scale image decomposition based image fusion using structure tensor
Authors: Du Jiao , Li Weisheng
Published: September 2019

The PET/SPECT image generates functional information of the human brain. In the field of multimodal medical image fusion, the decomposition scheme of PET/SPECT image in pseudo‐color is thought to be negligible. In this article, a two‐step model for PET/SPECT image decomposition is proposed to achieve contrast enhancement that inherently captures gradient to distinguish individual edge information from detail information. First, sharp structure is preserved using structure tensor on the intensity component of PET/SPECT image. Second, sharp structure in gray is transformed back into the image in pseudo‐color by generalized intensity‐hue‐saturation, one of the color space methods. The combination of structure tensor and generalized intensity‐hue‐saturation based fusion technique can preserve not only more intensity information but also functional information content. Finally, we demonstrate the effectiveness of our proposed decomposition method in the context of PET/SPECT image and then make a comparison of fusion result by two‐scale image fusion method in terms of the full‐reference objective metric structural similarity and no‐reference objective metric natural image quality evaluator.
Analysis of relation between skin elasticity and the entropy of skin image using near‐infrared and visible light sources
Authors: Jung Geunho , Lee Min Young , Kim Sungchul , Lee Jee‐Bum , Kim Jae G.
Published: September 2019

Skin elasticity has been regarded as one of the main indicators of skin condition. Current measurement devices for skin elasticity are mostly expensive for home‐use and should contact the skin surface. As a first step to develop improved methods, we focus on the relation between skin elasticity and the entropy of skin images. Reduced skin elasticity causes wrinkles. It spreads frequency components and increases their randomness in the frequency domain. The randomness is quantified as entropy, which is a measure of the disorder of a system in physics. Therefore, skin elasticity is expected to have a negative relation with entropy. This tendency can be improved by applying penetration depth characteristics according to the wavelength of light. From cheeks and forehead of 12 Korean adults, skin images are acquired with three different light sources (470 nm, 870 nm and broadband light) and skin elasticity is measured. The root mean square error between the measured data and the fitted model is “0.27” (870 nm), “0.49” (broadband light) and “1.42” (470 nm). Furthermore, the results are analyzed by classifying by sex, age and measurement area. This study demonstrates the possibility of developing noncontact home‐use devices to measure skin elasticity in the future.
In vivo monitoring the dynamic process of acute retinal hemorrhage and repair in zebrafish with spectral‐domain optical coherence tomography
Authors: Lin Yanping , Xiang Xiang , Chen Tingru , Mao Guangjuan , Deng Lijun , Zeng Lvming , Zhang Jian
Published: September 2019

Retina, the only light sensor in the human eye, is hidden and extremely fragile. Optimized animal models and efficient imaging techniques are very important for the study of retinopathy. In this work, the rapid retinal injury process and the long‐term retinal repair process were in vivo continuously evaluated with a novel imaging technology spectral‐domain optical coherence tomography (SD‐OCT) in a unique animal model zebrafish. Acute retinal injury was constructed on adult zebrafish by needle injection surgery. SD‐OCT imaging was carried out immediately after the mechanical injury. The retinal hemorrhage, which lasted only 5 seconds, could be visualized dynamically by SD‐OCT. The process of blood clearance and retinal repair was also evaluated because SD‐OCT imaging is nondestructive. Both SD‐OCT imaging results and behavioral analyzing results demonstrated that zebrafish retina could be repaired by itself within 15 days, which was confirmed by the results of pathological experiment.