bluuebunny/crossref_metadata_2025 huggingface dataset:
CD43 sialoglycoprotein modulates cardiac inflammation and murine susceptibility to Trypanosoma cruzi infection
Authors: Alisson-Silva Frederico , Mantuano Natália Rodrigues , Lopes Ana Luiza , Vasconcelos-dos-Santos Andréia , Vale André Macedo , Costa Miriam Maria , Cannon Judy L. , Oliveira Ana Carolina , Todeschini Adriane R.
Published: June 2019

CD43 (leukosialin) is a large sialoglycoprotein abundantly expressed on the surface of most cells from the hematopoietic lineage. CD43 is directly involved in the contact between cells participating in a series of events such as signaling, adherence and host parasite interactions. In this study we examined the role of CD43 in the immune response againstTrypanosoma cruzi, the protozoan parasite that causes Chagas’ disease, a potential life-threatening illness endemic in 21 Latin American countries according to the WHO. The acute stage of infection is marked by intense parasitemia and cardiac tissue parasitism, resulting in the recruitment of inflammatory cells and acute damage to the heart tissue. We show here thatCD43−/−mice were more resistant to infection due to increased cytotoxicity of antigen specific CD8+ T cells and reduced inflammatory infiltration in the cardiac tissue, both contributing to lower cardiomyocyte damage. In addition, we demonstrate that the induction of acute myocarditis involves the engagement of CD43 cytoplasmic tripeptide sequence KRR to ezrin-radixin-moiesin cytoskeletal proteins. Together, our results show the participation of CD43 in different events involved in the pathogenesis ofT. cruziinfection, contributing to a better overall understanding of the mechanisms underlying the pathogenesis of acute chagasic cardiomyopathy.
A fluorimetric nitrite biosensor with polythienothiophene-fullerene thin film detectors for on-site water monitoring
Authors: Pires Nuno Miguel Matos , Dong Tao , Yang Zhaochu
Published: June 2019

A nitrite microfluidic biosensor with integrated PTB7:PC70BM organic photodetectors for on-site water monitoring applications.
Isomerization of cyanopropyne in solid argon
Authors: Custer Thomas , Szczepaniak Urszula , Gronowski Marcin , Piétri Nathalie , Couturier-Tamburelli Isabelle , Guillemin Jean-Claude , Turowski Michał , Kołos Robert
Published: June 2019

Cyanopropyne, CH3–CC–CN, is a simple molecule whose photochemistry we have explored. UV photolysis of this molecule in an Ar matrix was performed and quantum chemical calculations used to better understand photoproduct production.
Effects ofin vivoconditions on amyloid aggregation
Authors: Owen Michael C. , Gnutt David , Gao Mimi , Wärmländer Sebastian K. T. S. , Jarvet Jüri , Gräslund Astrid , Winter Roland , Ebbinghaus Simon , Strodel Birgit
Published: June 2019

One of the grand challenges of biophysical chemistry is to understand the principles that govern protein aggregation leading to amyloid fibrils, which is a highly complex and sensitive process. This review provides a comprehensive overview of how amyloid aggregation is affected by the variousin vivoconstituents and conditions.
Dispersive micro-solid phase extraction based on Fe3O4@SiO2@Ti-MOF as a magnetic nanocomposite sorbent for the trace analysis of caffeic acid in the medical extracts of plants and water samples prior to HPLC-UV analysis
Authors: Moradi Zohreh , Alipanahpour Dil Ebrahim , Asfaram Arash
Published: June 2019

In this work, Fe3O4@SiO2@Ti-MOF-NCs, as an efficient sorbent, have been synthesized in a laboratory and utilized for extracting CA in the medical extracts of plants and water samples before their analysis by HPLC.
Triggering Cu-coordination change in Cu(ii)-Ala-His-His by external ligands
Authors: Gonzalez Paulina , Bossak-Ahmad Karolina , Vileno Bertrand , Wezynfeld Nina E. , El Khoury Youssef , Hellwig Petra , Hureau Christelle , Bal Wojciech , Faller Peter
Published: June 2019

A switch in copper(ii)-coordination between the two motifs Xxx-Zzz-His (ATCUN) and Xxx-His in the hybride peptide Ala-His-His is induced by adding a ligand such as imidazole.
A triple-amplification strategy based on the formation of peroxidase-like two-dimensional DNA/Fe3O4 networks initiated by the hybridization chain reaction for highly sensitive detection of microRNA
Authors: Tang Sheng , Li Yana , Zhu Anni , Yao Yao , Sun Jun , Zheng Fenfen , Lin Zixia , Shen Wei
Published: June 2019

Peroxidase-like two-dimensional DNA/Fe3O4 networks were constructed by the hybridization chain reaction and applied to detect microRNA down to the aM level.
Synthesis of anatase particles via morphological control of titanium glycerolate intermediate precursor
Authors: Yakaboylu Gunes Alp , Ozsoy Keskinbora Cigdem , Sahin Yucel , Suvaci Ender
Published: June 2019

The morphologies of titanium glycerolate precursors were controlled to obtain anatase particles with a high surface area and large aspect ratio.
A silver(i) coordination polymer with sodium 3,5-dimethyl-4-sulfonate pyrazolate: a nice example of PXRD structure solution and time-driven crystallization
Authors: Brenna Stefano , Ardizzoia G. Attilio , Colombo Valentina , Sironi Angelo
Published: June 2019

A silver(i) coordination polymer with the sodium salt of 3,5-dimethyl-4-sulfonate pyrazole (HLNa) has been prepared and structurally characterized by ab initio X-ray powder diffraction.
Optimizing the thermoelectric transport properties of Bi2O2Se monolayer via biaxial strain
Authors: Wang Ning , Li Menglu , Xiao Haiyan , Gong Hengfeng , Liu Zijiang , Zu Xiaotao , Qiao Liang
Published: June 2019

The thermal-electric performance of Bi2O2Se can be significantly improved by application of tensile strain and the Bi2O2Se monolayer has great potential as thermoelectric (TE) material.
N–NO & NN–O bond cleavage dynamics in two- and three-body Coulomb explosion of the N2O2+ dication
Authors: Gope Krishnendu , Luzon Itamar , Strasser Daniel
Published: June 2019

Triatomic Coulomb explosion dynamics are initiated by single-photon double ionization of N2O with an ultrafast EUV pulse and are probed by delayed near-IR pulses.
Thermocatalytic depolymerization of kraft lignin to guaiacols using HZSM-5 in alkaline water–THF co-solvent: a realistic approach
Authors: Raikwar Deepak , Majumdar Saptarshi , Shee Debaprasad
Published: June 2019

A study representing depolymerization of kraft lignin in a batch reactor with higher loading attaining high conversion and guaiacol selectivity simultaneously and its correlation with structural modifications.
Soluble non-toxic carbon nano-rods for the selective sensing of iron(iii) and chromium(vi)
Authors: Chauhan Neetu , Anand Satyesh Raj , Aggarwal Ruchi , Kaushik Jaidev , Shekhawat Sandeep Singh , Sonker Amit Kumar , Sonkar Sumit Kumar
Published: June 2019

A simpler methodology has reported for the fabrication of non-toxic functionalized soluble carbon nano-rods for the sensing of Fe(iii) and Cr(vi) in aqueous media.
Stabilization of an intramolecular hydrogen-bond block in an s-triazine insensitive high-energy material
Authors: Li Jie , Wang Shucun , Liao Longyu , Ma Qing , Zhang Zhenqi , Fan Guijuan
Published: June 2019

A unique intramolecular hydrogen-bond block was stabilized in s-triazine insensitive high-energy materials with face-to-face stacking.
Assessment of neurotoxicity induced by different-sized Stöber silica nanoparticles: induction of pyroptosis in microglia
Authors: Du Qiqi , Ge Dan , Mirshafiee Vahid , Chen Chen , Li Min , Xue Changying , Ma Xuehu , Sun Bingbing
Published: June 2019

Stöber silica nanoparticles induce size-dependent pyroptotic cell death in microglia while with minimum cytotoxicity in microendothelial cells and neurons.
Investigation ofleptin receptorrs1137101 G>A polymorphism with cancer risk: evidence from 35936 subjects
Authors: Rong Guoxiang , Tang Weifeng , Wang Yafeng , Qiu Hao , Chen Shuchen
Published: June 2019

Leptin receptor (LEPR) signaling may be involved in promoting angiogenesis and proliferation, inhibiting apoptosis and playing a vital role in the progression of carcinogenesis. A number of studies have focused on the association of LEPR rs1137101 variants with susceptibility of cancer, however, the observed results were controversial. We searched literature on the relationship of LEPR rs1137101 G>A polymorphism with cancer risk by using PubMed and Embase databases, covering all publications up to 14 October 2018. In total, 44 case–control studies with 35,936 subjects were included. After combining all eligible studies, we identified null relationship between LEPR gene rs1137101 G>A polymorphism and overall cancer risk [A vs. G: odds ratio (OR ) =  0.97, 95% confidence interval (CI ) =  0.89–1.06, P = 0.547; AA vs. GG: OR  =  0.93, 95% CI  =  0.78–1.13, P = 0.476; AA/GA vs. GG: OR  =  0.99, 95% CI  =  0.91–1.09, P= 0.890 and AA vs. GA/GG: OR  = 0.92, 95% CI  =  0.82–1.04, P= 0.198]. However, in a subgroup analysis, there was an increased susceptibility of oral and oropharyngeal cancer in AA vs. GA/GG genetic model (OR, 1.83; 95% CI, 1.01–3.33; P=0.048). Considering the limited participants were included, the findings might be underpowered. Sensitivity analysis identified that any independent study omitted did not materially influence the pooled ORs and CIs. The results of publication bias detection showed that there was no evidence of bias. In summary, this analysis indicates that no significant association of cancer risk was identified to be correlated with rs1137101 G>A variants, even in stratified analyses.
Diagnostic Precision of Open-Set Versus Closed-Set Word Recognition Testing
Authors: Yu Tzu-Ling J. , Schlauch Robert S.
Published: June 2019

Purpose

The aim of the study was to examine the precision of forced-choice (closed-set) and open-ended (open-set) word recognition (WR) tasks for identifying a change in hearing.

Method

WR performance for closed-set (4 and 6 choices) and open-set tasks was obtained from 70 listeners with normal hearing. Speech recognition was degraded by presenting monosyllabic words in noise (−8, −4, 0, and 4 signal-to-noise ratios) or processed by a sine wave vocoder (2, 4, 6, and 8 channels).

Results

The 2 degraded speech understanding conditions yielded similarly shaped, monotonically increasing psychometric functions with the closed-set tasks having shallower slopes and higher scores than the open-set task for the same listening condition. Fitted psychometric functions to the average data were the input to a computer simulation conducted to assess the ability of each task to identify a change in hearing. Individual data were also analyzed using 95% confidence intervals for significant changes in scores for words and phonemes. These analyses found the following for the most to least efficient condition: open-set (phoneme), open-set (word), closed-set (6 choices), and closed-set (4 choices).

Conclusions

Closed-set WR testing has distinct advantages for implementation, but its poorer precision for identifying a change than open-set WR testing must be considered.
Reliability of the Language Environment Analysis Recording System in Analyzing French–English Bilingual Speech
Authors: Orena Adriel John , Byers-Heinlein Krista , Polka Linda
Published: June 2019

Purpose

This study examined the utility of the Language ENvironment Analysis (LENA) recording system for investigating the language input to bilingual infants.

Method

Twenty-one French–English bilingual families with a 10-month-old infant participated in this study. Using the LENA recording system, each family contributed 3 full days of recordings within a 1-month period. A portion of these recordings (945 minutes) were manually transcribed, and the word counts from these transcriptions were compared against the LENA-generated adult word counts.

Results

Data analyses reveal that the LENA algorithms were reliable in counting words in both Canadian English and Canadian French, even when both languages are present in the same recording. While the LENA system tended to underestimate the amount of speech in the recordings, there was a strong correlation between the LENA-generated and human-transcribed adult word counts for each language. Importantly, this relationship holds when accounting for different-gendered and different-accented speech.

Conclusions

The LENA recording system is a reliable tool for estimating word counts, even for bilingual input. Special considerations and limitations for using the LENA recording system in a bilingual population are discussed. These results open up possibilities for investigating caregiver talk to bilingual infants in more detail.
Distributed integral control of multiple UAVs: precise flocking and navigation
Authors: Saif Osamah , Fantoni Isabelle , Zavala‐Río Arturo
Published: June 2019

The authors interest in this work is to perform a precise real‐time flocking of multiple unmanned aerial vehicles (UAVs). A consensus‐based flocking algorithm that ensures a precise security distance between UAVs is proposed. By using Lyapunov theoretical analysis, the authors propose a flocking algorithm that ensures the ultimate boundedness of multiple‐UAV system solutions. Moreover, this algorithm is enhanced by a distributed integral control that renders the inter‐distances between UAVs more precise. Finally, experimental results are provided to prove and show the efficiency of these algorithms.
Event‐triggered distributed optimisation for multi‐agent systems with transmission delay
Authors: Yu Gang , Shen Yanjun
Published: June 2019

In this study, the authors discuss the event‐triggered distributed optimisation algorithm for multi‐agent systems with sampled‐data and transmission delay. Each agent only knows its local objective function and exchanges information with its connected neighbours through the network. Firstly, they present sufficient conditions of exponential stability for a class of hybrid non‐linear systems by using continuous and discrete analysis. Then, based on these conditions, a distributed optimisation algorithm is proposed such that a multi‐agent system achieves consensus and optimality. Finally, a simulation example is provided to verify the effectiveness of the theoretical results.
Equality‐constrained state estimation for hybrid systems
Authors: Eras‐Herrera Wendy Y. , Mesquita Alexandre R. , Teixeira Bruno O.S.
Published: June 2019

The authors investigate the problem of state estimation for stochastic hybrid dynamical systems with state equality constraints. They divided this problem into three categories depending on the linearity or non‐linearity of equality constraints as well as on the dependence of constraints on the operating mode. For the mode‐independent equality‐constrained linear case, they present sufficient conditions on process dynamics and filter initial conditions so that the classical interacting multiple model (IMM) algorithm yields state estimates satisfying the linear equality constraint for all subsequent times. For both linear and non‐linear systems, the mode‐dependent equality constraints must be enforced over time by the filter. They present a modified version of the IMM filter to enforce the equality constraints in such cases. Their numerical results show that the proposed methods provide more accurate estimates than the IMM unconstrained estimates.
New result on robust stability of switched systems with all subsystems unstable
Authors: Xu Xiaozeng , Mao Xiang , Li Yang , Zhang Hongbin
Published: June 2019

In this study, the stability problem of continuous‐time switched systems composed fully of unstable subsystems is considered. Unlike the hybrid conditions derived in previous literature, this study used a novel time‐dependent quadratic Lyapunov function approach and a convex sufficient condition for switched linear systems is proposed in the framework of bounded maximum average dwell time (BMADT). The resulting condition in this study is enforced using the sum of squares programming. Then, the condition for switched linear systems is extended to uncertain systems and the robust stability condition is derived. Moreover, a new stability result of continuous‐time switched systems with all subsystems unstable is investigated based on the BMADT conditions. The simulation shows that it is better than the results in previous literature. Two numerical examples are proposed to illustrate the authors' approach.
Data‐driven‐based event‐triggered tracking control for non‐linear systems with unknown disturbance
Authors: Li Hai‐Feng , Wang Ying‐Chun , Zhang Hua‐Guang
Published: June 2019

A novel event‐triggered model‐free adaptive tracking control problem is studied for non‐linear systems with unknown bounded disturbance. A general dynamic linearisation model framework with disturbance input is developed and event‐triggered‐based model‐free adaptive control algorithm is designed by using pseudo‐partial derivatives method and input/output measurement data. Owing to the existence of unknown disturbance, a disturbance estimator is designed based on the optimisation criterion technique. Then, a new event‐triggering mechanism with dead‐zone operator is designed to improve the utility of network communication resources without Zeno phenomenon. Then, an observer‐based controller with disturbance compensation is developed, such that the tracking error between the system output and desired output signal converges to a small residual set around the origin. Finally, two simulation examples are provided to show the effectiveness and practicability of the proposed approach.
Urban rail transit passenger flow forecast based on LSTM with enhanced long‐term features
Authors: Yang Dan , Chen Kairun , Yang Mengning , Zhao Xiaochao
Published: June 2019

Outbreak passenger flow is the main cause of rail transit congestion. In this regard, the accurate forecast of passenger flow in advance will facilitate the traffic control department to redeploy infrastructures. Traffic sequence is a typical time series with long temporal dependence. For instance, an emergency may cause traffic congestion for the next several hours. Only a few studies focused on the way to capture long temporal dependence of passenger flow in the rail transit system. Here, an improved model enhanced long‐term features based on long‐short‐term memory (ELF‐LSTM) neural network is proposed. It takes full advantages of LSTM Neural Network (LSTM NN) models in processing time series and overcomes its limitations in insufficient learning of long temporal dependency due to time lag. The proposed network strengthens the long temporal dependency features embedded in passenger flow data and incorporates the short‐term features to predict the origin destination (OD) flow in the next hour. The experiment results show that ELF‐LSTM outperforms other state‐of‐the‐art methods in terms of forecasting.
Pseudopemphigoid bei topischer Glaukomtherapie
Authors: Geerling Gerd , Roth Mathias
Published: June 2019

Das Pseudopemphigoid ist eine chronische Erkrankung, die zu einer fortschreitenden Vernarbung der Bindehaut bis hin zur Symblepharonbildung führt. Phänotypisch lässt es sich kaum vom echten Schleimhautpemphigoid mit okulärer Beteiligung unterscheiden. Mögliche Auslöser sind Erkrankungen der Augenoberfläche und/oder deren Therapie. Circa die Hälfte aller betroffenen Patienten sind Glaukompatienten unter entsprechender Therapie mit topischen Antiglaukomatosa. Fehlende Zeichen einer systemischen Erkrankung, ein einseitiger Befund und/oder eine positive Glaukomanamnese können auf ein Pseudopemphigoid hinweisen. Im Rahmen dieser Übersicht sollen die beiden Entitäten gegenübergestellt und das diagnostische sowie therapeutische Vorgehen bei Verdacht auf Pseudopemphigoid unter topischer Glaukomtherapie dargestellt werden.
Over-the-scope clip in peptic ulcer bleeding: clinical success in primary and secondary treatment and factors associated with treatment failure
Authors: Gölder Stefan , Neuhas Lukas , Freuer Denis , Probst Andreas , Ebigbo Alanna , Braun Georg , Brueckner Juliane , Stueckle Johannes , Meier Alexander , Messmann Helmut
Published: June 2019

Background and study aims It is unclear if the clinical success rate of the over-the-scope-clip (OTSC) in peptic ulcer bleeding (PUB) is comparable when it is used in the first- or in the second-line of treatment.

Patients and methods Data on endoscopic treatment (first- vs. second-line) in PUB with OTSC and clinical data were analyzed. The primary outcome was the clinical success of hemostasis, defined as the absence of recurrent bleeding or further intervention. Secondary outcomes were factors associated with OTSC failure.

Results From April 2014 to March 2018, 100 patients (age 72 [20 – 98] y, female 36 %) with PUB in the stomach or the duodenum were treated endoscopically with the OTSC. The OTSC was used as a first-line procedure (primary-OTSC) in 66 pts. Successful hemostasis could be achieved in 90.9 %. After failure of an initial endoscopic treatment, 34 patients were treated with the OTSC (secondary-OTSC) and the treatment was successful in 94.1 %. Recurrent bleeding occurred in n = 10 for primary-OTSC (16.7 %) and in n = 7 pts in the secondary-OTSC (21.9 %) (P = 0.81). Clinical success in the primary-OTSC was 75.8 % and 73.5 % in the secondary-OTSC respectively.

Conclusions The OTSC has a high rate of initial bleeding control in first- and second line treatment of PUB. OTSC failure occurs more often in the duodenum than in the stomach and results in longer intensive care unit stay, higher amount of transfusions, and a higher reimbursement per case.
Personalisierte Medizin im Urothelkarzinom der Harnblase
Authors: Grunewald Camilla Marisa , Niegisch Günter
Published: June 2019

Während sich die zur Verfügung stehenden Therapieoptionen und die Prognose von Patienten mit Urothelkarzinom der Harnblase insbesondere im metastasierten Stadium über Jahrzehnte hinweg bisher kaum verbessert haben, hat der zunehmende Einsatz von Hochdurchsatzanalysen und das Wissen um den Einfluss des Immunsystems auf Tumorentstehung und -progression unser Verständnis von Tumorbiologie in den letzten Jahren grundlegend verändert.

Die Kenntnis von genetischen Mutationen und molekularen Subtypen bieten zunehmend die Möglichkeit maßgeschneiderter Therapieansätze für Patienten, die an einem Harnblasenkarzinom leiden. Veränderungen in DNA-Reparatur-Signalwegen stellen beispielsweise mögliche Prädiktoren für ein Chemotherapie-Ansprechen dar, zielgerichtete Therapien mittels FGFR- oder PARP-Inhibitoren befinden sich aktuell in klinischer Erprobung und könnten zukünftig die Therapie ergänzen. Inwieweit molekulare Subtypen Einzug in die klinisch-pathologische Routine halten werden, hängt von der prospektiven Evaluation ihres prognostischen und prädiktiven Stellenwerts ab. Insbesondere der Einzug von Immuncheckpoint-Inhibitoren ist die bedeutendste Erweiterung der zur Verfügung stehenden Therapieoptionen. Jedoch verdeutlicht sich angesichts des geringen Therapieansprechens von nur 25 % einmal mehr die dringende Notwendigkeit prädiktiver Biomarker.

Vor allem die große inter- und intratumorale Heterogenität stellt eine große Herausforderung für die klinische Implementierung personalisierter Therapieansätze im Harnblasenkarzinom dar. Insgesamt wurden in den letzten Jahren wichtige Schritte in Richtung personalisierter Medizin beim Urothelkarzinom der Harnblase unternommen, deren prospektive Evaluation größtenteils jedoch noch aussteht.
An Old Dog with New Tricks: Enjoin Wolff–Kishner Reduction for Alcohol Deoxygenation and C–C Bond Formations
Authors: Li Chao-Jun , Huang Jianlin , Dai Xi-Jie , Wang Haining , Chen Ning , Wei Wei , Zeng Huiying , Tang Jianting , Li Chenchen , Zhu Dianhu , Lv Leiyang
Published: June 2019

The Wolff–Kishner reduction, discovered in the early 1910s, is a fundamental and effective tool to convert carbonyls into methylenes via deoxygenation under strongly basic conditions. For over a century, numerous valuable chemical products have been synthesized by this classical method. The reaction proceeds via the reversible formation of hydrazone followed by deprotonation with the strong base to give an N-anionic intermediate, which affords the deoxygenation product upon denitrogenation and protonation. By examining the mechanistic pathway of this century old classical carbonyl deoxygenation, we envisioned and subsequently developed two unprecedented new types of chemical transformations: a) alcohol deoxygenation and b) C–C bond formations with various electrophiles including Grignard-type reaction, conjugate addition, olefination, and diverse cross-coupling reactions.

1 Introduction

2 Background

3 Alcohol Deoxygenation

3.1 Ir-Catalyzed Alcohol Deoxygenation

3.2 Ru-Catalyzed Alcohol Deoxygenation

3.3 Mn-Catalyzed Alcohol Deoxygenation

4 Grignard-Type Reactions

4.1 Ru-Catalyzed Addition of Hydrazones with Aldehydes and Ketones

4.2 Ru-Catalyzed Addition of Hydrazone with Imines

4.3 Ru-Catalyzed Addition of Hydrazone with CO2

4.4 Fe-Catalyzed Addition of Hydrazones

5 Conjugate Addition Reactions

5.1 Ru-Catalyzed Conjugate Addition Reactions

5.2 Fe-Catalyzed Conjugate Addition Reactions

6 Cross-Coupling Reactions

6.1 Ni-Catalyzed Negishi-type Coupling

6.2 Pd-Catalyzed Tsuji–Trost Alkylation Reaction

7 Other Reactions

7.1 Olefination

7.2 Heck-Type Reaction

7.3 Ullmann-Type Reaction

8 Conclusion and Outlook
Morphology induced spectral reflectance lineshapes in VO2 thin films
Authors: Ertas Uslu Merve , Yalcin Refet Ali , Misirlioglu I. Burc , Sendur Kursat
Published: June 2019

In this work, we study the spectral reflectance of VO2 thin films and identify the specific contributions of the morphology and phase transition to optical spectra. The formation of highly [011] textured VO2 thin films on Si was achieved by an oxidation process starting with a metallic V thin film grown on an [001] Si substrate by an evaporation technique. Structural (XRD and Raman) and spectroscopic (XPS) characterization results indicate high purity VO2 formation with different sizes at various annealing temperatures without any change in the composition. Temperature dependent spectral reflectance distributions reveal that the insulator-to-metal transition (IMT) phase transition temperature of the VO2 nanostructures shows a slight size-dependence (∼3 °C), but this feature can be overshadowed by morphology that can lead to the misinterpretation of transition characteristics. The spectral line shape of the reflectance curves in the visible and near-infrared regions show substantially different characteristics for the samples annealed at different temperatures. Using numerical scattering calculations, we conclude that the changes in the optical response can be explained by morphological effects instead of changes in the intrinsic material properties such as a shift in the IMT temperature. Furthermore, the main mechanism leading to different spectral line shapes is the morphological differences leading to diffuse and specular reflectance.
Estimation of extrinsic parameters for dynamic binocular stereo vision using unknown-sized rectangle images
Authors: Wang Yue , Wang Xiangjun , Yin Lei
Published: June 2019

An online calibration method of extrinsic parameters for dynamic binocular stereo vision using unknown-sized rectangle images is presented herein. The two cameras can rotate freely in two-axis direction without zooming, and the cameras’ intrinsic parameters and initial relative position are known in advance. Hence, only the rotation angles of the cameras, namely, the yaw angle in the horizontal direction and the pitch angle in the vertical direction, must be solved. The approximate values of the rotation angles are obtained by the Ellipse-A attitude and heading reference system in real time, and the rotation angles of each camera are solved iteratively using only a single rectangular centroid according to interimage homography. The pitch and yaw angles are eventually modified based on the property of fundamental matrix by the corresponding rectangular centroids, obtained by the left and right cameras after rotation, respectively. Computer simulations and real experiments are performed to validate the efficiency of the proposed method, and we compare calibration results with that of the scale-invariant feature transform method and Zhang’s method. The quantitative results demonstrate that the root mean square (rms) of the absolute error of the attitude angles and the translation vector does not exceed 0.12° and 7.2 mm, respectively. Additionally, the rms of the relative error of the three-dimensional coordinates does not exceed 1.6%.
An eight-channel correlation electron cyclotron emission diagnostic for turbulent electron temperature fluctuation measurement in HL-2A tokamak
Authors: Fang K. R. , Shi Z. B. , Yang Z. C. , Jiang M. , Zhong W. L. , Wen J. , Shi P. W. , Li Y. G. , Liu Z. T. , Liu Y. , Ding X. T. , Yang Q. W. , Xu M.
Published: June 2019

A new correlation electron cyclotron emission (CECE) diagnostic has recently been installed on the HL-2A tokamak in order to study electron temperature fluctuations. Eight radial locations are measured simultaneously through eight pairs of correlated channels. Multiplexers are employed in the intermediate frequency section instead of the conventional separated filter banks to meet strict cross-isolation specifications and lower insertion loss. Relative electron temperature fluctuations are observed by CECE for the first time on the HL-2A by using the spectral decorrelation method. The achieved minimum detectable fluctuation level is up to (T̃e/Te)min∼0.5%. When studying electron temperature fluctuations in the core region with gas puffing, the cross-power spectra show that the amplitude of the electron temperature fluctuation increases in a high temperature and low density plasma. Further analysis demonstrates that the electron temperature gradient ∇Te drives the electron temperature fluctuations together with electron heat transport.
Kinetic simulations of sheared flow stabilization in high-temperature Z-pinch plasmas
Authors: Tummel K. , Higginson D. P. , Link A. J. , Schmidt A. E. W. , Offermann D. T. , Welch D. R. , Clark R. E. , Shumlak U. , Nelson B. A. , Golingo R. P. , McLean H. S.
Published: June 2019

The first fully kinetic particle-in-cell (PIC) simulations of sheared flow stabilized Z-pinch plasmas show the suppression of the sausage instability by shear, ∂rvz ≠ 0, with flow Mach numbers ≲1, consistent with experimental observations. Experimental investigations of sheared-flow stabilized Z-pinches demonstrated stability for 10 s of microseconds, over 1000 Alfvén radial transit times, in quasi steady-state plasmas that are an intermediate between conventional inertial and magnetic confinement systems. The observed stability coincides with the presence of radial shear in axial flow profiles with peak speeds less than Mach 1, and experiments are underway to validate scaling this design to fusion conditions. The experimentally observed stability agrees with models of m = 1 kink mode suppression by sheared flows, but existing models of the m = 0 sausage mode underestimate the efficacy of sheared flow stabilization. These models rely on fluid approximations and find that stabilization requires flows ranging from Mach 1.7 to 4.3, and in some cases, stabilization is not reproduced in the models. This is faster than the measured flows in long-lived plasmas and would necessitate substantial energy convection out of the Z-pinch and the need to drive and sustain supersonic flows in future devices. The MHD models typically used in the literature are invalid in the high-temperature, high-current environments desirable for many Z-pinch applications, and they ignore large Larmor radius effects and viscous dissipation which are known to impact Z-pinch stability. PIC simulations can capture all these effects as well as kinetic instabilities that could influence the performance of high-temperature sheared flow stabilized Z-pinch plasmas. The PIC simulations presented here show the suppression and damping of m = 0 modes by sheared flows ∂rvz = 0.75vA/r0 with flow Mach numbers ≲1. Equivalent stability occurs under plasma conditions ranging from the limits of present-day experimental capabilities to the projected conditions of a sheared flow stabilized Z-pinch reactor.
Electron magnetic resonance of iron-gallium borate single crystals
Authors: Seleznyova Kira , Strugatsky Mark , Yagupov Sergey , Mogilenec Yuliya , Drovosekov Alexey , Kreines Natalia , Rosa Patrick , Kliava Janis
Published: June 2019

Electron magnetic resonance (EMR) studies of iron-gallium borate, FexGa1−xBO3, single crystals have been carried out in the frequency range ca. 8–38 GHz in magnetizing fields up to 10 kOe and the temperature range of 4–310 K. With decreasing x in the range of 0.34≤x≤1, the EMR spectra show a gradual passage from a low-frequency antiferromagnetic resonance (AFMR) mode at x = 1 toward a coexistence of AFMR and cluster magnetic resonance arising, respectively, from completely and partially magnetically ordered crystal regions. Temperature and concentration dependences of magnetic characteristics of iron-gallium borates, namely, the Néel temperature, the Dzyaloshinskii–Moriya field, and the isotropic energy gap, have been determined by means of AFMR. In contrast to unmixed FeBO3, FexGa1−xBO3 crystals with 0.34≤x≤0.85 show anomalous nonmonotonic temperature dependences of the Dzyaloshinskii–Moriya field with a maximum well below the Néel temperature suggesting the occurrence of another magnetic transition in this temperature range.
Structural and electrical characterizations of hydrothermally grown hydroxyapatite polycrystals: A morphological hierarchy
Authors: Chatterjee T. , Das A. K. , Lala S. , Pradhan S. K. , Meikap A. K.
Published: June 2019

Pure hydroxyapatite (HAp) semiconducting microrods with very low dielectric loss have been synthesized in aqueous media of pH values 6, 8, and 10 by the hydrothermal method. Samples are characterized by X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectra analyses. The optical bandgap energies of these samples are found to be within the semiconducting range (∼3–4 eV). FESEM and TEM image analyses reveal the formation of microrods and reduction of the average length of the rods with increasing pH values. A core-shell-like microrod structure has been observed in the sample with pH value 6. The charge carrier follows an adiabatic small polaron hopping mechanism. The dielectric loss values are very small compared to that of other ceramic oxides which is very advantageous for electronic applications. Correlated barrier hopping model is the dominant charge transport mechanism within the samples with maximum barrier heights of 0.25 eV, 0.26 eV, and 0.27 eV for samples with pH values 6, 8, and 10, respectively. Nonideal Debye type relaxation appears within the material when the AC field is applied for temperatures above 100 °C.
Improved crystalline quality and electric conductivity in infinite-layer SrFeO2 films through Sm substitution
Authors: Katayama Tsukasa , Chikamatsu Akira , Kumigashira Hiroshi , Hasegawa Tetsuya
Published: June 2019

We investigated the effect of Sm3+ substitution on the crystalline quality and transport properties of “infinite layer” SrFeO2 epitaxial thin films. Sm-substituted SrFeO2 (Sr1-xSmxFeO2) films were prepared via a topotactic reaction using CaH2 on KTaO3 (KTO) and DyScO3 (DSO) substrates. The films exhibited metallic behavior with higher conductivity than the undoped ones on both KTO and DSO. The carrier density of the Sm-substituted film was much lower than the Sm3+ concentrations, suggesting that the electron carriers generated by Sm were mostly compensated by excess oxide ions residing at the apical sites of Fe. The Sm-substitution also enhanced the crystalline quality of the films, probably because the excess oxide ions stabilized the framework of the infinite layer structure. We found a strong correlation between the conductivity and the crystalline quality in the films, indicating that the conductivity of Sm-substituted SrFeO2 was dominated by the crystalline quality. Furthermore, a high Hall mobility of 13.5 cm2 V−1 s−1 was achieved at 300 K in the x = 0.05 film.
Imaging Michelson interferometer for a low-density gas jet characterization
Authors: Nejdl J. , Vančura J. , Boháček K. , Albrecht M. , Chaulagain U.
Published: June 2019

A new optical probing method with increased interferometric sensitivity for a low-density gas jet characterization is presented. The proposed technique employs a Michelson interferometer with a self-imaging object arm, which enables the relay imaging of the object on itself, and in this way, the phase sensitivity of the device is increased by a double propagation of the object laser beam through the gas jet. The wavelength of 405 nm was chosen to further increase the sensitivity by increasing the probe wavenumber. A low-density argon gas jet with various backing pressures was characterized by our method and by a commonly used Mach-Zehnder interferometer setup showing the expected twofold increase in the signal to noise ratio in the double pass configuration.
A music-box-like extended rotational plucking energy harvester with multiple piezoelectric cantilevers
Authors: Fang Shitong , Fu Xinlei , Du Xiaona , Liao Wei-Hsin
Published: June 2019

Vibrational interference has been found to incur inefficient system responses and suboptimal energy harvesting performance as the rotational frequency increases in the conventional rotational plucking energy harvester. As a result, this letter proposes a music-box-like structure of a rotational plucking energy harvester to overcome the problem by extending the rotary cylinder out of plane. A model is proposed and experimentally validated by characterizing its dynamic and energetic characteristics. Numerical analyses show that the proposed rotational plucking structure can reduce the vibrational interference and be capable of harvesting more energy at high rotational frequencies as well as extending the operating frequency range and broadening the half-power bandwidth.
Tunable thermo-stable microwave filter using dielectric metamolecule
Authors: Li Haohua , Wang Xiaobo , Zhou Ji
Published: June 2019

We demonstrate a dielectric metamolecule composed of ceramic and ferrite, which can be regarded as an equivalent LC circuit. When temperature varies, inductance is adjusted via the active ambient effective permeability of the metamolecule, thus counteracting the frequency drift caused by the temperature coefficient of the ceramic. The introduction of the ferrite meta-atom permits magnetic tunability, widening the working band of the filter. Additionally, the metamolecule inherits the high Q-value of the ceramic resonator. This work opens up an opportunity for realizing miniaturized, thermostable, tunable microwave filters with high-Q values in the fields of communication.
Enhancement of strength and ductility of cement-based composites by incorporating silica nanoparticle coated polyvinylalcohol fibers
Authors: Meng Jing , Zhong Jing , Xiao Huigang , Ou Jinping
Published: June 2019

Addition of fibers can give brittle material extrinsic toughness, mainly because of the bridging effects. However, such behavior is highly dependent on the interfacial interaction between fiber and brittle matrix. In order to optimize both the strength and ductility of cement, which is the most extensively used brittle material on this planet, here we propose a new strategy to control the interfacial property in the fiber-cement matrix. Silica-coated polyvinylalcohol fibers were successfully synthesized by a sol-gel method with controlled silica thickness, and then incorporated into cement paste. The interaction between fibers and cement matrix was significantly enhanced due to the greatly increased hydrophilicity and roughness of silica-coated fibers, as well as the pozzolanic reactivity of silica nanoparticles. Therefore, the interfacial region between fiber and cement becomes much more compact, promoting the fiber-cement interaction both physically and chemically. As such, the crack propagation would be severely constrained, resulting in the strength and ductility of cement significantly increased. We showed that the ultimate flexural strength and ultimate deflection of the cement composites reinforced by silica-coated polyvinylalcohol fibers increase by 187% and 980% with respect to pristine cement, and increase by 28% and 74% compared to cement reinforced by polyvinylalcohol fibers without silica, at the fiber content of 1 wt.%. This study illustrates the potential and effectiveness of interfacial design to overcome the mechanical dilemma of strength and ductility increase simultaneously, and open a new dimension to further improve the mechanical properties of cement.
Treg-mediated prolonged survival of skin allografts without immunosuppression
Authors: Pilat Nina , Wiletel Mario , Weijler Anna M. , Steiner Romy , Mahr Benedikt , Warren Joanna , Corpuz Theresa M. , Wekerle Thomas , Webster Kylie E. , Sprent Jonathan
Published: June 2019

Significance

The use of specific IL-2/anti–IL-2 complexes (IL-2 cplxs) has shown great potency in the prevention of allograft rejection in mice. While long-term tolerance could be achieved toward islet allografts, clinically relevant skin graft models have remained elusive so far. Using a new protocol, this study documents that IL-2 cplxs can greatly prolong the survival of skin allografts and prevent sensitization of the recipient. The data provide support for the importance of regulatory mechanisms and organ-specific approaches when targeting allograft rejection.
How the avidity of polymerase binding to the –35/–10 promoter sites affects gene expression
Authors: Einav Tal , Phillips Rob
Published: June 2019

Significance

Cellular behavior is ultimately governed by the genetic program encoded in the cell’s DNA and through the arsenal of molecular machines that actively transcribe its genes, yet we lack the ability to predict how an arbitrary DNA sequence will perform. To that end, we analyze the performance of over 10,000 regulatory sequences and develop a model that can predict the behavior of any sequence based on its composition. By considering promoters that vary only by one or two elements, we can characterize how different components interact, providing fundamental insights into the mechanisms of transcription.
Krüppel-like factor 3 inhibition by mutated lncRNAReg1cpresults in human high bone mass syndrome
Authors: Yang Mi , Guo Qi , Peng Hui , Xiao Yu-Zhong , Xiao Ye , Huang Yan , Li Chang-Jun , Su Tian , Zhang Yun-Lin , Lei Min-Xiang , Chen Hui-Ling , Jiang Tie-Jian , Luo Xiang-Hang
Published: June 2019

High bone mass (HBM) is usually caused by gene mutations, and its mechanism remains unclear. In the present study, we identified a novel mutation in the long noncoding RNA Reg1cp that is associated with HBM. Subsequent analysis in 1,465 Chinese subjects revealed that heterozygous Reg1cp individuals had higher bone density compared with subjects with WT Reg1cp. Mutant Reg1cp increased the formation of the CD31hiEmcnhi endothelium in the bone marrow, which stimulated angiogenesis during osteogenesis. Mechanistically, mutant Reg1cp directly binds to Krüppel-like factor 3 (KLF3) to inhibit its activity. Mice depleted of Klf3 in endothelial cells showed a high abundance of CD31hiEmcnhi vessels and increased bone mass. Notably, we identified a natural compound, Ophiopogonin D, which functions as a KLF3 inhibitor. Administration of Ophiopogonin D increased the abundance of CD31hiEmcnhi vessels and bone formation. Our findings revealed a specific mutation in lncRNA Reg1cp that is involved in the pathogenesis of HBM and provides a new target to treat osteoporosis.
Mg2+ regulation of kinase signaling and immune function
Authors: Kanellopoulou Chryssa , George Alex B. , Masutani Evan , Cannons Jennifer L. , Ravell Juan C. , Yamamoto Tori N. , Smelkinson Margery G. , Jiang Ping Du , Matsuda-Lennikov Mami , Reilley Julie , Handon Robin , Lee Ping-Hsien , Miller J. Richard , Restifo Nicholas P. , Zheng Lixin , Schwartzberg Pamela L. , Young Matthew , Lenardo Michael J.
Published: June 2019

Mg2+ is required at micromolar concentrations as a cofactor for ATP, enzymatic reactions, and other biological processes. We show that decreased extracellular Mg2+ reduced intracellular Mg2+ levels and impaired the Ca2+ flux, activation marker up-regulation, and proliferation after T cell receptor (TCR) stimulation. Reduced Mg2+ specifically impairs TCR signal transduction by IL-2–inducible T cell kinase (ITK) due to a requirement for a regulatory Mg2+ in the catalytic pocket of ITK. We also show that altered catalytic efficiency by millimolar changes in free basal Mg2+ is an unrecognized but conserved feature of other serine/threonine and tyrosine kinases, suggesting a Mg2+ regulatory paradigm of kinase function. Finally, a reduced serum Mg2+ concentration in mice causes an impaired CD8+ T cell response to influenza A virus infection, reduces T cell activation, and exacerbates morbidity. Thus, Mg2+ directly regulates the active site of specific kinases during T cell responses, and maintaining a high serum Mg2+ concentration is important for antiviral immunity in otherwise healthy animals.
Endothelial ERK1/2 signaling maintains integrity of the quiescent endothelium
Authors: Ricard Nicolas , Scott Rizaldy P. , Booth Carmen J. , Velazquez Heino , Cilfone Nicholas A. , Baylon Javier L. , Gulcher Jeffrey R. , Quaggin Susan E. , Chittenden Thomas W. , Simons Michael
Published: June 2019

To define the role of ERK1/2 signaling in the quiescent endothelium, we induced endothelial Erk2 knockout in adult Erk1−/− mice. This resulted in a rapid onset of hypertension, a decrease in eNOS expression, and an increase in endothelin-1 plasma levels, with all mice dying within 5 wk. Immunostaining and endothelial fate mapping showed a robust increase in TGFβ signaling leading to widespread endothelial-to-mesenchymal transition (EndMT). Fibrosis affecting the cardiac conduction system was responsible for the universal lethality in these mice. Other findings included renal endotheliosis, loss of fenestrated endothelia in endocrine organs, and hemorrhages. An ensemble computational intelligence strategy, comprising deep learning and probabilistic programing of RNA-seq data, causally linked the loss of ERK1/2 in HUVECs in vitro to activation of TGFβ signaling, EndMT, suppression of eNOS, and induction of endothelin-1 expression. All in silico predictions were verified in vitro and in vivo. In summary, these data establish the key role played by ERK1/2 signaling in the maintenance of vascular normalcy.
The 229-thorium isomer: doorway to the road from the atomic clock to the nuclear clock
Authors: Thirolf P G , Seiferle B , von der Wense L
Published: June 2019

The elusive ‘thorium isomer’, i.e. the isomeric first excited state of 229Th, has puzzled the nuclear and fundamental physics communities for more than 40 years. With an exceptionally low excitation energy and a long lifetime it represents the only known candidate so far for an ultra-precise nuclear frequency standard (‘nuclear clock’), potentially able to outperform even today’s best timekeepers based on atomic shell transitions, and promising a variety of intriguing applications. This tutorial reviews the development of our current knowledge on this exotic nuclear state, from the first indirect evidence in the 1970s, to the recent breakthrough results that pave the way towards the realization of a nuclear clock and its applications in practical fields (satellite based navigational systems and chronometric geodesy) as well as fundamental physics beyond the standard model (the search for topological dark matter and temporal variations of fundamental constants).