bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Multifunctional Polymeric Soft Template for Synthesizing Nitrogen and Phosphorus Co–Doped Mesoporous Carbon Frameworks Electrocatalysts for Oxygen Reduction Reaction
Authors: Ma Jun , Yu Yue , Chen Changli , Xiao Dejian , Li Kai , Ma Jie , Liao Yi , Zuo Xia
Published: August 2018

To replace high‐cost and non‐resistant platinum‐based electrocatalysts for oxygen reduction reaction (ORR), the development of low‐cost, durable and high‐efficiency nonprecious metal catalysts is urgently needed. Thereinto, metal‐free heteroatom‐doped carbon materials as one of the promising candidates are quite satisfying for its designability of material properties, remarkable electrocatalytic activity and unexceptionable durability. In this work, a novel and rational method by using multifunctional polymeric soft template: poly [cyclotriphosphazene‐co‐(4, 4’‐(hexafluoroisopropylidene) diphenol)] (PZAF) particles for synthesis PZAF@PANI composite which is further treated under high temperature for generating N, P co‐doped mesoporous carbons (NPMPCs) is utilized. The resultant NPMPCs exhibit a mesoporous structure with ultra large specific surface area (1465.091 m2 g−1) and total pore volume (1.068 cm3 g−1), which can optimize the ORR active sites derived from the N, P co‐doping. Based on these structural features, NPMPCs possess outstanding ORR activity, admirable durability and brilliant methanol tolerance, comparable or even better than that of commercial 20% Pt/C. The correlationship between the particular porous structure derived from the decomposition of PZAF particles and the nitrogen and phosphorus species in the carbon frameworks of the electrocatalysts with considerable catalytic activity are thoroughly investigated.
Five Diverse Multidimensional Polycarboxylate–Based Mixed–Ligand Coordination Polymers with Different N,N′–Donor Ligands: Synthesis, Characterization and Their Sorption Study
Authors: Ghosh Saheli , Pahari Goutam , Maity Dilip K. , Halder Arijit , Ghoshal Debajyoti
Published: August 2018

Five mixed ligand coordination polymers (CPs) explicitly {[Cu2(btp)(2,5‐pyrdc)2H2O].4H2O}n (1), {[Cu(bte)0.5(2,5‐pyrbdc)H2O].1.5H2O}n (2), {[Cu(bte)(1, 2,4,5‐btc)0.5(H2O)].3H2O}n (3), {[Co(4‐bpdh)(1, 2,4,5‐btc)0.5(H2O)(MeOH)]}n (4), and {[Co(4‐bpdb)1.5(1,2,4,5‐btc)(H2O)4].4H2O(MeOH)}n (5) have been synthesized by using two polycarboxylates 2,5‐pyridinedicarboxylate (2,5‐pyrdc2–), 1,2,4,5‐benzenetetracarboxylate (1,2,4,5‐btc4–) and four differently polar N–donor ligands. Here, two different transition metals Cu(II) and Co(II) have been used and slow diffusion technique has been followed for crystallization process at room temperature. Single crystal X‐ray diffraction analysis, powder X‐ray diffraction (PXRD), infrared spectroscopy (IR), elemental analysis and thermo gravimetric analysis (TGA) techniques have been used to characterize all the five compounds 1–5. Compound 1 exhibits a 2D bilayer; fabricated by the N,N‘–donor 1,3‐bis(1,2,4‐triazol‐1‐yl)propane (btp) and 2,5‐pyrdc2– ligands with the Cu(II) metal center; whereas compound 2 shows a wavy 2D sheet structure by only variation of N–donor ligand to 1,2‐bis(1,2,4‐triazol‐1‐yl)ethane (bte). Compound 3 features a 3D MOF built by 2D metal carboxylate sheet of Cu(II) and 1,2,4,5‐btc4– pillared by bte spacer. Compound 5 displays two fold interpenetrated 3D framework containing two distorted octahedral Co(II) metal centers; formed by the 1,2,4,5‐btc4– and 1,4‐bis‐(4‐pyridyl)‐2,3‐diaza‐1,3‐butadiene (4‐bpdb) ligands whereas compound 4 attains a 1D chain only by variation of N–donor linker to 2,5‐bis‐(4‐pyridyl)‐3,4‐diaza‐2,4‐hexadiene (4‐bpdh). For the compounds 1–5, different sorption study has been carried out. The dehydrated framework of compound 5 shows selective CO2 adsorption at 195 K over N2 (at 77 K) which has been explained in terms of the strong interaction of CO2 molecules with polar moiety of the dehydrated framework of 5. Compound 1 and 2 exhibit both CO2 and N2 adsorptions but the presence of non‐polar, long chain ligands in the frameworks decreases the extent of sorption for both the cases; whereas 3 and 4 only give suitable result for N2 sorption.
Bi@C Nanoplates Derived from (BiO)2CO3 as an Enhanced Electrode Material for Lithium/Sodium‐Ion Batteries
Authors: Xiang Juan , Liu Zhiming , Song Taeseup
Published: August 2018

Two‐dimensional (2D) carbon coated bismuth nanoplates (Bi@C) were prepared by a self‐template and subsequent thermal treatment process utilizing 2D (BiO)2CO3 nanosheets as starting material. The 2D nanoplates provide feasible pathways for electrons and ions while the outer carbon‐coated layer efficiently prohibited the agglomeration of Bi and accommodated the huge volume change of Bi during the charging/discharging process. The as‐obtained Bi@C nanoplates maintain a capacity higher than 420 mAh g−1 after 150 cycles as an anode of lithium ion batteries (LIBs). For sodium ion batteries (SIBs), a capacity of approximately 200 mAh g−1 over 200 cycles was achieved by the Bi@C electrode. The as‐obtained 2D Bi@C nanoplates solves the problem of low conductivity and a large volume change of Bi when applied as an anode of secondary batteries, offering a simple, low‐cost, and eco‐friendly method for fabricating bismuth‐carbon composite electrodes with excellent electrochemical performance in LIBs and SIBs.
One‐step preparation of Fe2O3/reduced graphene oxide aerogel as heterogeneous Fenton‐like catalyst for enhanced photo‐degradation of organic dyes
Authors: Feng Yan , Yao Tongjie , Yang Yang , Zheng Furen , Chen Peng , Wu Jie , Xin Baifu
Published: August 2018

In this paper, Fe2O3/reduced graphene oxide (rGO) aerogel with a three‐dimensional hierarchical porous structure was prepared by hydrothermal method in one‐step, where Fe2O3 nanoparticles (NPs) were uniformly anchored on two sides of rGO nanosheets. In aerogel, rGO support not only dispersed Fe2O3 NPs, but also increased adsorption ability, improved mass diffusion and accelerated electron transfer; namely, synergistic effect was generated by combining rGO and Fe2O3 together. As expected, in photo‐Fenton degradation of rhodamine B, Fe2O3/rGO aerogel displayed higher degradation ability than referenced samples. A series of influence factors on degradation efficiencies were investigated. Based on inhibitor tests and controlled experiments, a possible degradation mechanism was proposed. Besides satisfied degradation ability, the aerogel also displayed superior stability and reusability. After 5 recycling runs, both chemical composition and degradation efficiency were well maintained.
Self‐Assembly of L‐Arginine on Electrophoretically Deposited Hydroxyapatite Coatings
Authors: Duru İlayda , Ege Duygu
Published: August 2018

In this study, L‐Arginine (L‐Arg) molecules are self‐assembled on HA coatings for potential orthopedic applications. By immersing HA coatings in L‐Arg solution in phosphate buffer saline (PBS) with a pH of 7.4 at room temperature for 24 hours, L‐Arg assembled on HA. The samples were characterized by using Scanning Electron Microscopy (SEM), X‐ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflection‐Fourier Transform Infrared Spectroscopy (ATR‐FTIR), X‐ray Diffraction (XRD), Atomic Force Microscopy (AFM) and ninhydrin assay. The response of human bone marrow derived mesenchymal stem cells (hBMSCs) to HA and L‐Arg/HA coatings both in growth and osteogenic differentiation medium are reported. In the growth medium, cells are found to be more spread out on L‐Arg/HA coatings than HA coatings. Moreover, cell aggregates which are indicators of differentiation are observed on HA coatings spontaneously in the growth medium and cell aggregates are only observed on L‐Arg/HA coatings in the osteogenic differentiation medium. Overall, this study showed that L‐Arg self‐assembles on HA and it hinders osteogenic differentiation of hBMSCs in the growth medium.
A Pyrene‐Benzothiazole Probe that is Ultrasensitive to the Environment Polarity and Its Own Characteristics
Authors: Ghosh Ashutosh , Seth Sourav Kanti , Purkayastha Pradipta
Published: August 2018

Environment‐sensitive fluorescent probes are of great importance in chemical and biological research. We have developed a cationic benzothizole derivative that has a pyrene moiety at the tip of the hydrophobic tail. The probe is of comparable length as the cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants. The compound shows characteristic fluorescence from its own locally excited (LE) state in non‐polar medium. However, it is weakly fluorescent in the aqueous environment that comes from the pyrene excimer. It is found that the polarity of this compound reverses in the excited state that substantially affects the LE fluorescence.
Drilled to obey? Ex‐military CEOs and financial misconduct
Authors: Koch‐Bayram Irmela F. , Wernicke Georg
Published: August 2018

Research Summary: We examine the influence of CEOs' military background on financial misconduct using two distinctive datasets. First, we make use of accounting and auditing enforcement releases (AAER) issued by the U.S. Securities and Exchange Commission (SEC), which contain intentional and substantial cases of financial fraud. Second, we use a dataset of “lucky grants,” which provide a measure of the likelihood of grant dates of CEOs' stock options having been manipulated. Results for both datasets indicate that CEOs who served in the military are less inclined to be involved in fraudulent financial reporting and to backdate stock options. In addition, we find that these relationships are moderated by board oversight (CEO duality and independent directors in the board).

Managerial Summary: CEOs who formerly served in the U.S. military are prevalent among U.S. firms. The military puts strong emphasis on the obedience of its personnel. In this study, we test if time spent in the military leads individuals to be more obedient to rules and regulations in the years after they have left the military and become CEOs. Our findings strongly suggest that CEOs who served in the U.S. military are less likely to be involved in financial misconduct. We also find evidence that tougher board oversight strengthens this relationship. Our findings have implications for regulators, auditors, practitioners, and researchers who are interested in determinants of and mechanisms to prevent fraud and stock option backdating.
Ultra‐Broadband Flexible Photodetector Based on Topological Crystalline Insulator SnTe with High Responsivity
Authors: Yang Jie , Yu Wenzhi , Pan Zhenghui , Yu Qiang , Yin Qing , Guo Lei , Zhao Yanfei , Sun Tian , Bao Qiaoliang , Zhang Kai
Published: August 2018

Topological crystalline insulators (TCIs) are predicted to be a promising candidate material for ultra‐broadband photodetectors ranging from ultraviolet (UV) to terahertz (THz) due to its gapless surface state and narrow bulk bandgap. However, the low responsivity of TCIs‐based photodetectors limits their further applications. In this regard, a high‐performance photodetector based on SnTe, a recently developed TCI, working in a broadband wavelength range from deep UV to mid‐IR with high responsivity is reported. By taking advantage of the strong light absorption and small bandgap of SnTe, photodetectors based on the as‐grown SnTe crystalline nanoflakes as well as specific short channel length achieve a high responsivity (71.11 A W−1 at 254 nm, 49.03 A W−1 at 635 nm, 10.91 A W−1 at 1550 nm, and 4.17 A W−1 at 4650 nm) and an ultra‐broad spectral response (254–4650 nm) simultaneously. Moreover, for the first time, a durable flexible SnTe photodetector fabricated directly on a polyethylene terephthalate film is demonstrated. These results prove the great potential of TCIs as a promising material for integrated and flexible optoelectronic devices.
Impact of Environmental Stresses Onto Transport Properties of Hybrid Perovskite Investigated by Steady State Photocarrier Grating and Steady State Photocurrent Techniques
Authors: Longeaud Christophe , Ramos F. Javier , Rebai Amelle , Rousset Jean
Published: August 2018

In this study, the transport properties of high quality double and triple cation perovskite are explored under different environmental stresses by Steady State Photocurrent (SSPC) and Steady State Photocarrier Grating (SSPG) measurements. SSPG allows a direct measurement of the ambipolar diffusion length that is significantly higher for the cesium containing perovskite (1.4 micron compared to 0.57 micron for a double cation compound). This positive effect is shown to be reversibly annihilated as the samples are put under vacuum, and to be accelerated with the increase of the temperature. The degradation of the material properties appears together with the activation of a defect trap level and a rise of the doping level in the material. This behavior is discussed considering the interaction between the iodine vacancies contained in the perovskite and oxygen which is known to lead to trap passivation.
High‐Performance Green Solvent Processed Ternary Blended All‐Polymer Solar Cells Enabled by Complementary Absorption and Improved Morphology
Authors: Li Zhenye , Xie Ruihao , Zhong Wenkai , Fan Baobing , Ali Jazib , Ying Lei , Liu Feng , Li Ning , Huang Fei , Cao Yong
Published: August 2018

Ternary all‐polymer solar cells (all‐PSCs) attract considerable research attention owing to the simplicity of the single‐junction device architecture and the broad absorption range of the light‐harvesting layer. However, the difficulty in controlling the morphology of ternary blended films makes it challenging to develop high‐performance ternary all‐PSCs. Herein, we report on the development of efficient ternary blended all‐PSCs by incorporating the narrow‐bandgap electron‐donating polymer PNTB, which contains a naphtho[1,2‐c:5,6‐c′]bis([1,2,5]thiadiazole) moiety, into blend films comprising the wide‐bandgap electron‐donating copolymer PBTA‐BO and the electron‐accepting copolymer N2200. The resulting ternary blended devices reached an impressively high power conversion efficiency of 10.09%, which obviously outperforms those obtained from binary blended counterparts. The improved photovoltaic performance is attributable to the combined effects of the extended absorption profile, a favorable film morphology, and more efficient charge transfer. Of particular interest is that these ternary blend films are processed using a non‐halogenated solvent, 2‐methyltetrahydrofuran, which is promising for practical applications. These findings lend credence to the ternary approach as a facile and promising strategy for achieving high‐performance all‐PSCs.
C: Adding modern programming language features to C
Authors: Moss Aaron , Schluntz Robert , Buhr Peter A.
Published: August 2018

The C programming language is a foundational technology for modern computing with millions of lines of code implementing everything from hobby projects to commercial operating systems. This installation base and the programmers producing it represent a massive software engineering investment spanning decades and likely to continue for decades more. Nevertheless, C, which was first standardized almost 30 years ago, lacks many features that make programming in more modern languages safer and more productive. The goal of the C
project (pronounced “C for all”) is to create an extension of C that provides modern safety and productivity features while still ensuring strong backward compatibility with C and its programmers. Prior projects have attempted similar goals but failed to honor the C programming style; for instance, adding object‐oriented or functional programming with garbage collection is a nonstarter for many C developers. Specifically, C
is designed to have an orthogonal feature set based closely on the C programming paradigm, so that C
features can be added incrementally to existing C code bases, and C programmers can learn C
extensions on an as‐needed basis, preserving investment in existing code and programmers. This paper presents a quick tour of C
features, showing how their design avoids shortcomings of similar features in C and other C‐like languages. Experimental results are presented to validate several of the new features.
Aflatoxin B1 impairs spermatogenesis: An experimental study for crosslink between oxidative stress and mitochondria‐dependent apoptosis
Authors: Yasin Malekzadeh , Mazdak Razi , Mino Ilkhanipour
Published: August 2018

The present experimental study was carried out to investigate the crosslink between aflatoxin B1 (AFB1)‐induced oxidative stress and mitochondria‐dependent apoptosis in testicles. For this purpose, 24 mature male Swiss albino mice were randomly divided into control and test groups. The AFB1 was dissolved in corn oil and ethanol (95:5, v/v) vehicle. The animals in test group subdivided into three groups, which received the AFB1 at a daily dose of 20 μg/kg body weight, through intraperitoneal (i.p.) route, for 7, 14, and 21 days. The mice in the control group received the vehicle alone for 21 days. The expression of Bcl‐2, Bax, p53, and caspase‐3 at both mRNA and protein levels were analyzed by using reverse transcription PCR (RT‐PCR) and immunohistochemistry, respectively. Moreover, the mitochondrial content of germinal epithelium, tubular differentiation (TDI), and spermiogenesis (SPI) indices was analyzed. Finally, the apoptosis was assessed by using TUNEL staining. Observations revealed that the AFB1 remarkably (P < .05) reduced Bcl‐2 expression at both mRNA and protein levels. Up‐regulated Bax, caspase‐3, and p53 expression were revealed in AFB1‐received animals, which developed time‐dependently. Histological examinations exhibited a significant reduction in TDI and SPI indices. Finally, the AFB1‐induced apoptosis index increased time‐dependently. In conclusion, the AFB1 adversely affects the spermatogenesis via inducing oxidative stress, diminishing cellular mitochondrial content and enhancing pro‐apoptotic Bax, caspase‐3, and p53 expression. All these impairments result in mitochondria‐dependent apoptosis.
Reference ranges for Doppler indices of umbilical and fetal middle cerebral arteries and cerebroplacental ratio: systematic review
Authors: Oros D. , Ruiz‐Martinez S. , Staines‐Urias E. , Conde‐Agudelo A. , Villar J. , Fabre E. , Papageorghiou A. T.
Published: August 2018

Objective

To assess studies reporting reference ranges for umbilical artery (UA) and fetal middle cerebral artery (MCA) Doppler indices and cerebroplacental ratio (CPR), using a set of predefined methodological quality criteria for study design, statistical analysis and reporting methods.

Methods

This was a systematic review of observational studies in which the primary aim was to create reference ranges for UA and MCA Doppler indices and CPR in fetuses of singleton gestations. A search for relevant articles was performed in MEDLINE, EMBASE, CINAHL, Web of Science (from inception to 31 December 2016) and references of the retrieved articles. Two authors independently selected studies, assessed the risk of bias and extracted the data. Studies were scored against a predefined set of independently agreed methodological criteria and an overall quality score was assigned to each study. Linear multiple regression analysis assessing the association between quality scores and study characteristics was performed.

Results

Thirty‐eight studies met the inclusion criteria. The highest potential for bias was noted in the following fields: ‘ultrasound quality control measures’, in which only two studies demonstrated a comprehensive quality‐control strategy; ‘number of measurements taken for each Doppler variable’, which was apparent in only three studies; ‘sonographer experience’, in which no study on CPR reported clearly the experience or training of the sonographers, while only three studies on UA Doppler and four on MCA Doppler did; and ‘blinding of measurements’, in which only one study, on UA Doppler, reported that sonographers were blinded to the measurement recorded during the examination. Sample size estimations were present in only seven studies. No predictors of quality were found on multiple regression analysis. Reference ranges varied significantly with important clinical implications for what is considered normal or abnormal, even when restricting the analysis to the highest scoring studies.

Conclusions

There is considerable methodological heterogeneity in studies reporting reference ranges for UA and MCA Doppler indices and CPR, and the resulting references have important implications for clinical practice. There is a need for the standardization of methodologies for Doppler velocimetry and for the development of reference standards, which can be correctly interpreted and applied in clinical practice. We propose a set of recommendations for this purpose. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
PM personality: Dr Kalathur (Sim) Narasimhan, FASM. FAPMI, FIndPMI
Authors: Capus Joseph
Published: August 2018

After an outstanding career in the magnetic materials and PM industries, Dr Kalathur Narasimhan now advises companies globally through his own consulting firm, P2P Technologies. Metal Powder Report Consulting Editor Joseph Capus sat down with him at the Exhibition during the recent POWDERMET2018 Conference.
Toray's membranes play a pivotal role in projects in China and Saudi Arabia
Authors: Atkinson Simon
Published: August 2018

Toray Industries Inc – a Japanese manufacturer of membranes for applications that include reverse osmosis, nanofiltration, ultrafiltration, microfiltration and membrane bioreactors – is currently working on water treatment projects with companies and organisations in Japan, China and the Kingdom of Saudi Arabia. This month's news focus briefly looks at each of these projects, which are markedly different, and outlines the technology that is being employed.
De.mem – poised to enter lucrative FO market for dewatering applications
Authors: Atkinson Simon
Published: August 2018

Earlier this year Singaporean–Australian water and wastewater treatment company De.mem Ltd secured the exclusive rights to a new hollow-fibre forward osmosis (FO) technology. It was originally developed by researchers at Nanyang Technological University (NTU), Singapore, for applications involving industrial wastewater treatment – in particular dewatering reject/concentrate from membrane-based water treatment plants. Andreas Kroell, CEO, De.mem, believes there is a strong need for this technology, and in this brief interview he outlines its importance and explains why the company is poised to enter this multi-million dollar segment of the wastewater treatment market.
Overcoming the risks of privileged user abuse in Salesforce
Authors: Mason Mike
Published: August 2018

Privileged Salesforce users are necessary to every organisation. These are members of your organisation who have more advanced permission sets than the average user and can include Salesforce admins, sales reps, developers, HR staff, management and senior or executive leadership.

Privileged Salesforce users are necessary to every organisation. But they hold the keys to your kingdom, with access to a broad array of company data, security controls, workflows and resources.

These advanced users can make nearly unlimited changes to your Salesforce instance, placing your organisation at tremendous risk. And they can even cover their own tracks in the process. Privileged user abuse may be malicious or it may be unintentional. Either way, it represents a huge vulnerability to your company with the two main areas of concern being data security and compliance, explains Mike Mason of FairWarning.
Plugging IT/OT vulnerabilities – part 1
Authors: Caldwell Tracey
Published: August 2018

The separation between IT and operational technology (OT) networks, such as those linking manufacturing control systems, is breaking down. Not long ago, systems that monitor and control physical equipment were engineered and implemented independently from the computers, systems and applications that process, store and exchange operational data. But the line between IT and OT is blurring. In this, the first instalment of a two-part article on the impact of increasing IT and operating technology convergence on network security, industry experts contribute their assessment of the emerging threats.

The separation between IT and operational technology (OT) networks, such as those linking manufacturing control systems, is breaking down.

Not long ago, systems that monitored and controlled physical equipment were engineered and implemented independently from the computers, systems and applications that process, store and exchange operational data. But the line between IT and OT is blurring. In this first instalment of a two-part article, Tracey Caldwell asks industry experts for their assessment of the emerging threats.
The effect of impurities on striped phases
Authors: Jaramillo Gabriela , Scheel Arnd , Wu Qiliang
Published: August 2018

We study the effect of algebraically localized impurities on striped phases in one spatial dimension. We therefore develop a functional-analytic framework that allows us to cast the perturbation problem as a regular Fredholm problem despite the presence of the essential spectrum, caused by the soft translational mode. Our results establish the selection of jumps in wavenumber and phase, depending on the location of the impurity and the average wavenumber in the system. We also show that, for select locations, the jump in the wavenumber vanishes.
Seed treatments alleviate dormancy of field bindweed (Convolvulus arvensisL.)
Authors: Xiong Renci , Wang Ying , Wu Hanwen , Ma Yan , Jiang Weili , Ma Xiaoyan
Published: August 2018

Field bindweed, a member of the Convolvulaceae family, is a problematic perennial weed in cotton fields and orchards in northwest China. The species exhibits strong seed dormancy, causing delayed germination. A clear understanding of the mechanisms involved in alleviating seed dormancy is important for effective plant propagation and successful management of field bindweed. Experiments were conducted to investigate seed germination and radicle growth of field bindweed by breaking seed dormancy using mechanical scarification, sulfuric acid, hot-water scarification, cold stratification, and chemical treatment. Chemical treatments (gibberellic acid or potassium nitrate) had no effect on breaking seed dormancy, whereas mechanical scarification (sandpaper and blade) resulted in 92% to 98% seed germination, indicating that seed dormancy of field bindweed was mainly due to the presence of a hard seed coat. Seeds pretreated with 80% sulfuric acid for 15 to 60 min or 98% sulfuric acid for 15 to 30 min had germination rates above 80%, and soaking seeds in 70 C water for 4 to 16 min or in boiling water for 5 to 20s were effective in breaking seed dormancy but had no effect on the radicle growth of field bindweed. Cold stratification at 5 C for 2 to 8wk partially accelerated seed dormancy release, resulting in 53% to 67% seed germination. Results indicated that field bindweed could potentially form a persistent soil seed bank with physically dormant seed; therefore, strategies for eliminating seed production should be adopted.
Decadal Variability of North Pacific Eastern Subtropical Mode Water
Authors: Guo Yongqing , Lin Xiaopei , Wei Meng , Liu Cong , Men Guang
Published: August 2018

A significant decadal variability of the North Pacific Eastern Subtropical Mode Water (NPESTMW), related to the Pacific Decadal Oscillation, is identified from the gridded Argo and EN4 observational data sets. To investigate the decadal variability of the NPESTMW volume, the high‐resolution Estimating the Circulation and Climate of the Ocean, Phase II simulation is used to diagnose the volume budget of the NPESTMW density layer in the NPESTMW formation region (20°–36°N, 160°–120°W) between 1992 and 2016. Results show that NPESTMW is formed through subduction of low potential vorticity (PV) water. This low‐PV water subduction is mainly determined by mixed layer depth change and lateral induction, which account for approximately 58% and 32%, respectively. The decadal NPESTMW volume anomaly is originated from the Pacific Decadal Oscillation‐induced decadal anomaly of air‐sea buoyancy flux. This decadal buoyancy flux anomaly drives the decadal anomaly of mixed layer depth change, then causes anomalous subduction, and leads to anomalous low‐PV water subduction. The decadal NPESTMW volume anomaly is finally generated by this anomalous low‐PV water subduction.
Morphology and structure of ZIF-8 during crystallisation measured by dynamic angle-resolved second harmonic scattering
Authors: Van Cleuvenbergen Stijn , Smith Zachary J. , Deschaume Olivier , Bartic Carmen , Wachsmann-Hogiu Sebastian , Verbiest Thierry , van der Veen Monique A.
Published: August 2018

Recent developments in nonlinear optical light scattering techniques have opened a window into morphological and structural characteristics for a variety of supramolecular systems. However, for the study of dynamic processes, the current way of measuring is often too slow. Here we present an alternative measurement scheme suitable for following dynamic processes. Fast acquisition times are achieved through Fourier imaging, allowing simultaneous detection at multiple scattering angles for different polarization combinations. This allows us to follow the crystal growth of the metal organic framework ZIF-8 in solution. The angle dependence of the signal provides insight into the growth mechanism by probing the evolution of size, shape and concentration, while polarization analysis yields structural information in terms of point group symmetry. Our findings highlight the potential of dynamic angle-resolved harmonic light scattering to probe crystal growth processes, assembly–disassembly of biological systems, adsorption, transport through membranes and myriad other applications.
Massively parallel fabrication of crack-defined gold break junctions featuring sub-3 nm gaps for molecular devices
Authors: Dubois Valentin , Raja Shyamprasad N. , Gehring Pascal , Caneva Sabina , van der Zant Herre S. J. , Niklaus Frank , Stemme Göran
Published: August 2018

Break junctions provide tip-shaped contact electrodes that are fundamental components of nano and molecular electronics. However, the fabrication of break junctions remains notoriously time-consuming and difficult to parallelize. Here we demonstrate true parallel fabrication of gold break junctions featuring sub-3 nm gaps on the wafer-scale, by relying on a novel self-breaking mechanism based on controlled crack formation in notched bridge structures. We achieve fabrication densities as high as 7 million junctions per cm2, with fabrication yields of around 7% for obtaining crack-defined break junctions with sub-3 nm gaps of fixed gap width that exhibit electron tunneling. We also form molecular junctions using dithiol-terminated oligo(phenylene ethynylene) (OPE3) to demonstrate the feasibility of our approach for electrical probing of molecules down to liquid helium temperatures. Our technology opens a whole new range of experimental opportunities for nano and molecular electronics applications, by enabling very large-scale fabrication of solid-state break junctions.
Origin of Circumpolar Deep Water intruding onto the Amundsen and Bellingshausen Sea continental shelves
Authors: Nakayama Yoshihiro , Menemenlis Dimitris , Zhang Hong , Schodlok Michael , Rignot Eric
Published: August 2018

Melting of West Antarctic ice shelves is enhanced by Circumpolar Deep Water (CDW) intruding onto the Amundsen and Bellingshausen Seas (ABS) continental shelves. Despite existing studies of cross-shelf and on-shelf CDW transports, CDW pathways onto the ABS originating from further offshore have never been investigated. Here, we investigate CDW pathways onto the ABS using a regional ocean model. Simulated CDW tracers from a zonal section across 67°S (S04P) circulate along the Antarctic Circumpolar Current (ACC) and Ross Gyre (RG) and travel into ABS continental shelf after 3–5 years, but source locations are shifted westward by ~900 km along S04P in 2001–2006 compared to 2009–2014. We find that simulated on- and off-shelf CDW is ~0.1–0.2 °C warmer in the 2009–2014 case than in the 2001–2006 case together with changes in simulated ocean circulation. These differences are primarily caused by lateral, rather than surface, boundary conditions, implying that large-scale atmospheric and ocean circulations are able to control CDW pathways and thus off- and on-shelf CDW properties.
Immunomodulatory role of Keratin 76 in oral and gastric cancer
Authors: Sequeira Inês , Neves Joana F. , Carrero Dido , Peng Qi , Palasz Natalia , Liakath-Ali Kifayathullah , Lord Graham M. , Morgan Peter R. , Lombardi Giovanna , Watt Fiona M.
Published: August 2018

Keratin 76 (Krt76) is expressed in the differentiated epithelial layers of skin, oral cavity and squamous stomach. Krt76 downregulation in human oral squamous cell carcinomas (OSCC) correlates with poor prognosis. We show that genetic ablation of Krt76 in mice leads to spleen and lymph node enlargement, an increase in regulatory T cells (Tregs) and high levels of pro-inflammatory cytokines. Krt76−/− Tregs have increased suppressive ability correlated with increased CD39 and CD73 expression, while their effector T cells are less proliferative than controls. Loss of Krt76 increases carcinogen-induced tumours in tongue and squamous stomach. Carcinogenesis is further increased when Treg levels are elevated experimentally. The carcinogenesis response includes upregulation of pro-inflammatory cytokines and enhanced accumulation of Tregs in the tumour microenvironment. Tregs also accumulate in human OSCC exhibiting Krt76 loss. Our study highlights the role of epithelial cells in modulating carcinogenesis via communication with cells of the immune system.
Organic carbon burial during OAE2 driven by changes in the locus of organic matter sulfurization
Authors: Raven Morgan Reed , Fike David A. , Gomes Maya L. , Webb Samuel M. , Bradley Alexander S. , McClelland Harry-Luke O.
Published: August 2018

Ocean Anoxic Event 2 (OAE2) was a period of dramatic disruption to the global carbon cycle when massive amounts of organic matter (OM) were buried in marine sediments via complex and controversial mechanisms. Here we investigate the role of OM sulfurization, which makes OM less available for microbial respiration, in driving variable OM preservation in OAE2 sedimentary strata from Pont d’Issole (France). We find correlations between the concentration, S:C ratio, S-isotope composition, and sulfur speciation of OM suggesting that sulfurization facilitated changes in carbon burial at this site as the chemocline moved in and out of the sediments during deposition. These patterns are reproduced by a simple model, suggesting that small changes in primary productivity could drive large changes in local OM burial in environments poised near a critical redox threshold. This amplifying mechanism may be central to understanding the magnitude of global carbon cycle response to environmental perturbations.
Medial septum activation produces opposite effects on dopamine neuron activity in the ventral tegmental area and substantia nigra in MAM vs. normal rats
Authors: Bortz David M. , Grace Anthony A.
Published: August 2018

The medial septum (MS) differentially impacts midbrain dopamine (DA) neuron activity via the ventral hippocampus, a region implicated in DA-related disorders. However, whether MS regulation of ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) is disrupted in a developmental disruption model of schizophrenia is unknown. Male Sprague-Dawley rats were exposed at gestational day 17 to methylazoxymethanol (MAM) or saline. As adults, NMDA (0.75 µg/0.2 µL) was infused into the MS, and either DA neuron activity in the VTA and SNc (7–9 anesthetized rats per group) or amphetamine-induced hyperlocomotion (AIH, 11-13 rats per group) was measured. MS activation produced a 58% increase in the number of spontaneously active DA neurons in VTA and a 37% decrease in SNc in saline rats. However, MS activation produced opposite effects on DA population activity in MAM rats, decreasing VTA DA activity by 51% and increasing SNc DA activity by 47%. MS activation also increased AIH by 113% in MAM rats, opposite of what is seen in intact rats. The effect in behavioral output may be due to disrupted GABAergic regulation of SNc as bicuculline infusion into vSub, which selectively prevented the MS activation-induced decrease in SNc DA activity in intact rats, prevented the increase in AIH and SNc DA activity in MAM rats. These findings demonstrate that the regulation of midbrain DA neurons by the MS is disrupted in this well-validated animal model, suggesting that it could be a potential locus for pharmacological intervention in disorders such as schizophrenia.
Impact of pore anisotropy on the thermal conductivity of porous Si nanowires
Authors: Ferrando-Villalba P. , D’Ortenzi L. , Dalkiranis G. G. , Cara E. , Lopeandia A. F. , Abad Ll. , Rurali R. , Cartoixà X. , De Leo N. , Saghi Z. , Jacob M. , Gambacorti N. , Boarino L. , Rodríguez-Viejo J.
Published: August 2018

Porous materials display enhanced scattering mechanisms that greatly influence their transport properties. Metal-assisted chemical etching (MACE) enables fabrication of porous silicon nanowires starting from a doped Si wafer by using a metal template that catalyzes the etching process. Here, we report on the low thermal conductivity (κ) of individual porous Si nanowires (NWs) prepared from MACE, with values as low as 0.87 W·m−1·K−1 for 90 nm diameter wires with 35–40% porosity. Despite the strong suppression of long mean free path phonons in porous materials, we find a linear correlation of κ with the NW diameter. We ascribe this dependence to the anisotropic porous structure that arises during chemical etching and modifies the phonon percolation pathway in the center and outer regions of the nanowire. The inner microstructure of the NWs is visualized by means of electron tomography. In addition, we have used molecular dynamics simulations to provide guidance for how a porosity gradient influences phonon transport along the axis of the NW. Our findings are important towards the rational design of porous materials with tailored thermal and electronic properties for improved thermoelectric devices.
Author Correction: Interplay of grounding-line dynamics and sub-shelf melting during retreat of the Bjørnøyrenna Ice Stream
Authors: Petrini Michele , Colleoni Florence , Kirchner Nina , Hughes Anna L. C. , Camerlenghi Angelo , Rebesco Michele , Lucchi Renata G. , Forte Emanuele , Colucci Renato R. , Noormets Riko
Published: August 2018

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Impact of fetal maceration grade on risk of maternal disseminated intravascular coagulation after intrauterine fetal death – A retrospective cohort study
Authors: Muin Dana A. , Haslacher Helmuth , Koller Vanessa , Kiss Herbert , Scharrer Anke , Farr Alex
Published: August 2018

Disseminated intravascular coagulation (DIC) is a life-threatening event that is the endpoint of a pathologically activated cascade leading to excessive consumption of platelets culminating in bleeding. Several diseases are known to be associated with DIC, some of which may also occur during pregnancy or the puerperium. One of the potential risk factors that have been considered as a potential trigger for DIC is the retention of a highly macerated fetus after intrauterine fetal death (IUFD). However, sparse evidence exists on its clinical implication on hemostasis parameters. In this retrospective single-center study, we investigated the role of fetal maceration grades 0-III on the risk of DIC in 91 women following IUFD between gestational weeks (+days) 22 + 0 and 41 + 6 between 2003 and 2017. We calculated the Erez DIC-score after consideration of maternal platelet count (PC), prothrombin time (PT) and fibrinogen (Fib) and correlated the findings with fetal maceration grade. Mean (±SD) age of women was 32.1 ± 6.7 years. Neither maternal hemostasis parameters (PC, PT, Fib), nor the Erez score showed a statistically significant difference between maceration grades 0-III with median values of 1 for all four grades (maceration grade I: range 0 to 27; I: 0 to 51; II: 0 to 52; III: 0 to 39). We therefore conclude, that the pathophysiology of DIC in women after singleton IUFD is unrelated to the degree of fetal maceration.
The Antihelminthic Niclosamide Inhibits Cancer Stemness, Extracellular Matrix Remodeling, and Metastasis through Dysregulation of the Nuclear β-catenin/c-Myc axis in OSCC
Authors: Wang Lin-Hong , Xu Mei , Fu Luo-Qin , Chen Xiao-Yi , Yang Fan
Published: August 2018

Niclosamide is an oral chlorinated salicylanilide antihelminthic agent with potential anticancer activity suggested in several cancer types, however, its anticancer action and likely molecular mechanism in malignant oral cells remain unclear. In the present study, we demonstrated that ALDH+ human oral squamous cell carcinoma (OSCC) cells are characterized by upregulated expression of the pluripotency transcription factors OCT4, Nanog and Sox2, as well as exhibit enhanced cancer stemness, as demonstrated by enhanced tumorsphere formation. We also showed that niclosamide effectively inhibits activation of the Wnt/β-catenin signaling pathway by targeting multiple components of this pathway, including downregulating the expression β-catenin, Dishevelled 2 (DVL2), phosphorylated glycogen synthase kinase-3β (p-GSK3β) and Cyclin D1, in human OSCC SCC4 and SCC25 cell lines, as well as reduced the formation of primary and secondary tumorspheres. In addition, we showed that niclosamide inhibits the epithelial-to-mesenchymal transition (EMT), migration and colony formation of the OSCC cells, by dose-dependently upregulating E-cadherin and the tissue inhibitor of metalloproteinases 2 (TIMP2) mRNA levels, while reducing the expression levels of vimentin, snail, MMP2 and MMP9 mRNA. These anticancer activities of niclosamide were similar to those caused by interference with nuclear β-catenin/c-Myc expression using the siRNA transfection. Finally, we demonstrated that niclosamide inhibits cisplatin-induced OSCC stem cell enrichment and enhances sensitivity to cisplatin in ALDH+ tumorspheres. These experimental data, combined with accumulated evidence, are suggestive of the potential and efficacy of niclosamide in the treatment of OSCC.
A roadmap of strain in doped anatase TiO2
Authors: Kelaidis N. , Kordatos A. , Christopoulos S.-R. G. , Chroneos A.
Published: August 2018

Anatase titanium oxide is important for its high chemical stability and photocatalytic properties, however, the latter are plagued by its large band gap that limits its activity to only a small percentage of the solar spectrum. In that respect, straining the material can reduce its band gap increasing the photocatalytic activity of titanium oxide. We apply density functional theory with the introduction of the Hubbard + U model, to investigate the impact of stress on the electronic structure of anatase in conjunction with defect engineering by intrinsic defects (oxygen/titanium vacancies and interstitials), metallic dopants (iron, chromium) and non-metallic dopants (carbon, nitrogen). Here we show that both biaxial and uniaxial strain can reduce the band gap of undoped anatase with the use of biaxial strain being marginally more beneficial reducing the band gap up to 2.96 eV at a tensile stress of 8 GPa. Biaxial tensile stress in parallel with doping results in reduction of the band gap but also in the introduction of states deep inside the band gap mainly for interstitially doped anatase. Dopants in substitutional positions show reduced deep level traps. Chromium-doped anatase at a tensile stress of 8 GPa shows the most significant reduction of the band gap as the band gap reaches 2.4 eV.
Integrative epigenomic analysis in differentiated human primary bronchial epithelial cells exposed to cigarette smoke
Authors: Glass Kimberly , Thibault Derek , Guo Feng , Mitchel Jennifer A. , Pham Betty , Qiu Weiliang , Li Yan , Jiang Zhiqiang , Castaldi Peter J. , Silverman Edwin K. , Raby Benjamin , Park Jin-Ah , Yuan Guo-Cheng , Zhou Xiaobo
Published: August 2018

Cigarette smoke (CS) is one of the major risk factors for many pulmonary diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. The first line of defense for CS exposure is the bronchial epithelial cells. Elucidation of the epigenetic changes during CS exposure is key to gaining a mechanistic understanding into how mature and differentiated bronchial epithelial cells respond to CS. Therefore, we performed epigenomic profiling in conjunction with transcriptional profiling in well-differentiated human bronchial epithelial (HBE) cells cultured in air-liquid interface (ALI) exposed to the vapor phase of CS. The genome-wide enrichment of histone 3 lysine 27 acetylation was detected by chromatin immunoprecipitation followed by next generation sequencing (ChIP-Seq) in HBE cells and suggested the plausible binding of specific transcription factors related to CS exposure. Additionally, interrogation of ChIP-Seq data with gene expression profiling of HBE cells after CS exposure for different durations (3 hours, 2 days, 4 days) suggested that earlier epigenetic changes (3 hours after CS exposure) may be associated with later gene expression changes induced by CS exposure (4 days). The integration of epigenetics and gene expression data revealed signaling pathways related to CS-induced epigenetic changes in HBE cells that may identify novel regulatory pathways related to CS-induced COPD.
PR-LncRNA signature regulates glioma cell activity through expression of SOX factors
Authors: Torres-Bayona Sergio , Aldaz Paula , Auzmendi-Iriarte Jaione , Saenz-Antoñanzas Ander , Garcia Idoia , Arrazola Mariano , Gerovska Daniela , Undabeitia Jose , Querejeta Arrate , Egaña Larraitz , Villanúa Jorge , Ruiz Irune , Sarasqueta Cristina , Urculo Enrique , Araúzo-Bravo Marcos J. , Huarte Maite , Samprón Nicolas , Matheu Ander
Published: August 2018

Long non-coding RNAs (LncRNAs) have emerged as a relevant class of genome regulators involved in a broad range of biological processes and with important roles in tumor initiation and malignant progression. We have previously identified a p53-regulated tumor suppressor signature of LncRNAs (PR-LncRNAs) in colorectal cancer. Our aim was to identify the expression and function of this signature in gliomas. We found that the expression of the four PR-LncRNAs tested was high in human low-grade glioma samples and diminished with increasing grade of disease, being the lowest in glioblastoma samples. Functional assays demonstrated that PR-LncRNA silencing increased glioma cell proliferation and oncosphere formation. Mechanistically, we found an inverse correlation between PR-LncRNA expression and SOX1, SOX2 and SOX9 stem cell factors in human glioma biopsies and in glioma cells in vitro. Moreover, knock-down of SOX activity abolished the effect of PR-LncRNA silencing in glioma cell activity. In conclusion, our results demonstrate that the expression and function of PR-LncRNAs are significantly altered in gliomagenesis and that their activity is mediated by SOX factors. These results may provide important insights into the mechanisms responsible for glioblastoma pathogenesis.