bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of some new Pyridine‐based Heterocyclic Compounds with Anticipated Antitumor Activity
Authors: Gomha Sobhi M. , Abdelrazek Fathy M. , Abdelrahman Aly H. , Metz Peter
Published: June 2018

A novel class of 5‐amino‐N′‐(1‐(pyridin‐4‐yl)ethylidene)‐1H‐pyrazole‐4‐carbohydrazides and 8‐(pyridin‐4‐yl)pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidin‐5(1H)‐ones was synthesized from reaction of 2‐cyano‐N′‐(1‐(pyridin‐4‐yl)ethylidene)‐acetohydrazide and 7‐(pyridin‐4‐yl)‐2‐thioxo‐2,3‐dihydropyrido[2,3‐d]pyrimidin‐4(1H)‐one with the appropriate hydrazonoyl halides. Moreover, 2‐cyano‐N′‐(1‐(pyridin‐4‐yl)‐ethylidene)‐acetohydrazide was used for the synthesis of 2‐cyano‐N′‐(1‐(pyridin‐4‐yl)ethylidene)‐acrylohydrazides and 2‐oxo‐2‐(2‐(1‐(pyridin‐4‐yl)ethylidene)‐hydrazinyl)‐acetohydrazonoyl cyanides. The structures of the newly prepared compounds were confirmed by both elemental and spectral analyses as well as by alternate synthesis. The anticancer activities of the prepared compounds were screened against the hepatocellular carcinoma (HepG2) cell line, and the results showed that most of the compounds exhibit considerable activities.
Accuracy of a Portable Indirect Calorimeter for Measuring Resting Energy Expenditure in Individuals With Cancer
Authors: Purcell Sarah A. , Elliott Sarah A. , Ryan Aoife M. , Sawyer Michael B. , Prado Carla M.
Published: June 2018

Background

Determining optimal caloric intake for an individual with cancer is complicated by metabolic changes that occur, namely, alterations in resting energy expenditure (REE). There is currently no validated clinically available equation or tool to measure energy expenditure in these patients.

Methods

Patients with newly diagnosed solid tumors underwent REE assessments using the FitMate GS portable indirect calorimeter and reference VMax metabolic cart; both used canopy hoods. REE was also estimated from the Harris‐Benedict, Mifflin St. Jeor, and Henry equations for comparison. Data were analyzed using paired samples t‐test and the Bland‐Altman approach to assess group‐level and individual‐level agreement compared with the metabolic cart.

Results

A total 26 patients (19 males; body mass index: 27.8 ± 5.5 kg/m2; age: 62 ± 10 years) participated in the study. Biases for the FitMate GS and both equations were low (ranging from −44 to −92 kcal or −2.3% to −5.1%), indicating good group‐level accuracy. The FitMate GS had low bias, but the widest limits of agreement (−28.0% to 21.2%) compared with the 3 equations (Harris‐Benedict: −15.8% to 11.2%; Mifflin St. Jeor: −17.1% to 6.9%; Henry: −15.4% to 11.5%). These differences were not due to volume of oxygen, BMI category, or sex.

Conclusion

FitMate GS performed well on a group level, but its accuracy was poor on an individual level. Further research should develop better equations and validate tools to measure energy expenditure for accurate dietary recommendations for patients at nutrition risk.
Extraction and determination of trace amounts of three anticancer pharmaceuticals in urine by three‐phase hollow fiber liquid‐phase microextraction based on two immiscible organic solvents followed by high‐performance liquid chromatography
Authors: Nazaripour Ali , Yamini Yadollah , Bagheri Hasan
Published: June 2018

An automated three‐phase hollow fiber liquid‐phase microextraction based on two immiscible organic solvents followed by high‐performance liquid chromatography with UV–Vis detection method was applied for the extraction and determination of exemestane, letrozole, and paclitaxel in water and urine samples. n‐Dodecane was selected as the supported liquid membrane and its polarity was justified by trioctylphosphine oxide. Acetonitrile was used as an organic acceptor phase with desirable immiscibility having n‐dodecane. All the effective parameters of the microextraction procedure such as type of the organic acceptor phase, the supported liquid membrane composition, extraction time, pH of the donor phase, hollow fiber length, stirring rate, and ionic strength were evaluated and optimized separately by a one variable at‐a‐time method. Under the optimal conditions, the linear dynamic ranges were 1.8–200 (R2 = 0.9991), 0.9–200 (R2 = 0.9987) and 1.2–200 μg/L (R2 = 0.9983), and the limits of detection were 0.6, 0.3, and 0.4 μg/L for exemestane, letrozole, and paclitaxel, respectively. To evaluate the capability of the proposed method in the analysis of biological samples, three different urinary samples were analyzed under the optimal conditions. The relative recoveries of the three pharmaceuticals were in the range of 91–107.3% for these three analytes.
A Meta‐Analysis of the Impact of Natural Disasters on Internalizing and Externalizing Problems in Youth
Authors: Rubens Sonia L. , Felix Erika D. , Hambrick Erin P.
Published: June 2018

Although exposure to natural disasters can lead to diverse mental health (MH) outcomes in youth, most child disaster MH research has focused on posttraumatic stress symptoms (PTSS). To highlight the likelihood of other MH outcomes, we meta‐analyzed studies that have examined other (non‐PTSS) internalizing and externalizing behavior problems in youth exposed to natural disasters. We used PRISMA guidelines to systematically gather studies that have examined the association between natural disaster exposure and non‐PTSS internalizing and/or externalizing problems in samples of children and adolescents. Analyses of random effects models of 62 studies examining non‐PTSS internalizing problems and 26 studies examining externalizing problems showed exposure to natural disasters was significantly associated with non‐PTSS internalizing, rmean = .18, k = 70, and externalizing problems, rmean = .08; k = 31, in youth. Moderator analyses revealed a stronger association between disaster exposure and non‐PTSS internalizing problems in countries with a “medium” Human Development Index (HDI) ranking, r = .56, than in countries with “high,” r = .15, and “very high,” r = .16, HDI rankings. We also found a stronger association between disaster exposure and externalizing problems in countries with a medium HDI ranking, r = .54, versus high, r = .05, and very high, r = .04, HDI rankings, and based on parent, r = .16, compared to child, r = −.01, report. Results support the need for assessment of multiple postdisaster MH outcomes to inform comprehensive interventions. We also include a discussion of the state of the disaster MH research.
Observed Emotional Expressivity, Posttraumatic Stress Disorder Symptoms, and Intimate Partner Violence Perpetration Among Community Couples
Authors: Sullivan Timothy J. , Leifker Feea R. , Marshall Amy D.
Published: June 2018

Impaired emotional processes are related to posttraumatic stress disorder (PTSD) and are implicated in intimate partner violence (IPV) perpetration. To address the interpersonal context of PTSD, emotion, and IPV, we examined interactions among one's own and one's partner's emotional expressivity and PTSD symptom severity in association with IPV perpetration. Heterosexual couples (N = 56) in which at least one partner met screening criteria for PTSD engaged in two video‐recorded discussions about negative and positive aspects of their relationships. Videos were coded for observed emotional expressiveness during moments participants reported experiencing significant emotions. Actor‐partner interdependence models revealed few main effects of emotional expressivity, except that women's expressivity of positive emotions was positively associated with men's IPV perpetration, r2adj = .14. Emotional expressivity played a larger role among couples managing PTSD symptoms; that is, the association between one's own PTSD symptom severity and more IPV perpetration was stronger among men who expressed more negative emotions, r2adj = .19, and women who expressed fewer negative emotions, r2adj = .21. Several partner effects suggested the importance of understanding the dyadic nature of these constructs. For example, men's PTSD symptom severity was differentially associated with each partners’ IPV perpetration based on women's expressivity of positive emotion, r2adj = .22–.27. Understanding of emotional expressivity in the link between PTSD and IPV must include consideration of gender differences in how these constructs operate interpersonally. Strategies to promote moderate and safe communication of positive and negative emotions may prevent IPV escalation, particularly among couples managing PTSD symptoms.
De facto diagnosis specialties: Recognition and discovery
Authors: Zhang Aston , Lu Xun , Gunter Carl A. , Yao Shuochao , Tao Fangbo , Zhu Rongda , Gui Huan , Fabbri Daniel , Liebovitz David , Malin Bradley
Published: June 2018

A medical specialty indicates the skills needed by health care providers to conduct key procedures or make critical judgments. However, documentation about specialties may be lacking or inaccurately specified in a health care institution. Thus, we propose to leverage diagnosis histories to recognize medical specialties that exist in practice. Such specialties that are highly recognizable through diagnosis histories are de facto diagnosis specialties. We aim to recognize de facto diagnosis specialties that are listed in the Health Care Provider Taxonomy Code Set (HPTCS) and discover those that are unlisted. First, to recognize the former, we use similarity and supervised learning models. Next, to discover de facto diagnosis specialties unlisted in the HPTCS, we introduce a general discovery‐evaluation framework. In this framework, we use a semi‐supervised learning model and an unsupervised learning model, from which the discovered specialties are subsequently evaluated by the similarity and supervised learning models used in recognition. To illustrate the potential for these approaches, we collect 2 data sets of 1 year of diagnosis histories from a large academic medical center: One is a subset of the other except for additional information useful for network analysis. The results indicate that 12 core de facto diagnosis specialties listed in the HPTCS are highly recognizable. Additionally, the semi‐supervised learning model discovers a specialty for breast cancer on the smaller data set based on network analysis, while the unsupervised learning model confirms this discovery and suggests an additional specialty for Obesity on the larger data set. The potential correctness of these 2 specialties is reinforced by the evaluation results that they are highly recognizable by similarity and supervised learning models in comparison with 12 core de facto diagnosis specialties listed in the HPTCS.
Statistical effects of surface preparation and coating type on the corrosion protection performance of repair coatings for offshore wind power constructions
Authors: Momber Andreas W. , Buchbach Sascha , Plagemann Peter , Marquardt Tom , Winkels Irmgard , Viertel Johannes
Published: June 2018

Three surface preparation methods, namely dry blast‐cleaning, grinding, and impact brushing, are applied for the preparation of steel substrates prior to the application of four different repair coating systems. The relationship between surface preparation method, coating type, coating thickness, and corrosion protection are systematically investigated with statistical methods. DoE (design of experiments) and ANOVA (analysis of variance) are used to rank the parameter effects. The repaired systems are exposed to the cyclic offshore aging test according to ISO 20340. Response parameters are rust creep and pull‐off strength. Coating system as well as surface preparation method show extreme statistical significance and have a high influence on the rust creep as well as on the pull‐off strength. Extremely significant interaction between the two factors could be found for the pull‐off strength only. Optimization calculations based on a desirability function approach (DFA) reveal that a combination of dry blast‐cleaning and lower coating thickness provided the best protection performance. If dry blast‐cleaning is not feasible, a higher coating thickness is recommended in order to maximize the corrosion protection performance.
Effect of machining on the stress corrosion cracking behavior in boiling magnesium chloride solution of austenitic stainless steel
Authors: Wu Huanchun , Li Chengtao , Fang Kewei , Xue Fei , Zhang Guodong , Luo Kunjie , Wang Li
Published: June 2018

The stress corrosion cracking (SCC) behaviors of Z3CN20.09M, 304L, and 316L austenitic stainless steels (SSs) after milling operation in boiling magnesium chloride solution were investigated by scanning electron microscopy (SEM), X‐ray diffraction, and 3D profilometer. The experimental results indicated that the roughness and residual stress increased with increasing feed rate of all specimens. The depth of deformation layer after milling operation reached about 150 µm shown as persistent slip bands (PSBs) were formed, leading to hardness enhanced obviously. After SCC tests in boiling magnesium chloride solution, the crack densities increased with increasing feed rate of the Z3CN20.09M SS specimens. However, the crack densities decreased as well as the intergranular (IG) cracking percentages increased with increasing feed rate of the 304L and 316L SS.
Enhancement of pure titanium localized corrosion resistance by anodic oxidation
Authors: Prando Davide , Brenna Andrea , Pedeferri MariaPia , Ormellese Marco
Published: June 2018

The corrosion behavior of commercially pure titanium (UNS R50400, ASTM grade 2) was investigated in presence of aggressive, bromides containing, species, reported to cause severe localized corrosion compared to chlorides. To enhance localized corrosion resistance of the metal, several surface treatments were performed. Samples anodized at potentials between 10 and 200 V were characterized in term of oxide thickness and morphology and tested with potentiodynamic analyses in ammonium bromide solution. Base metal was prepared both with etching and mechanical polishing pre‐treatment, to enlighten the effect of pre‐treatment sample preparation on post‐treatment corrosion resistance.
Recent Progress in Macromolecule‐Anchored Hybrid Gold Nanomaterials for Biomedical Applications
Authors: Luo Zheng , Xu Yang , Ye Enyi , Li Zibiao , Wu Yun‐Long
Published: June 2018

Gold nanoparticles (AuNPs), with elegant thermal, optical, or chemical properties due to quantum size effects, may serve as unique species for therapeutic or diagnostic applications. It is worth mentioning that their small size also results in high surface activity, leading to significantly impaired stability, which greatly hinders their biomedical utilizations. To overcome this problem, various types of macromolecular materials are utilized to anchor AuNPs so as to achieve advanced synergistic effect by dispersing, protecting, and stabilizing the AuNPs in polymeric–Au hybrid self‐assemblies. In this review, the most recent development of polymer–AuNP hybrid systems, including AuNPs@polymeric nanoparticles, AuNPs@polymeric micelle, AuNPs@polymeric film, and AuNPs@polymeric hydrogel are discussed with respect to their different synthetic strategies. These sophisticated materials with diverse functions, oriented toward biomedical applications, are further summarized into several active domains in the areas of drug delivery, gene delivery, photothermal therapy, antibacterials, bioimaging, etc. Finally, the possible approaches for future design of multifunctional polymer–AuNP hybrids by combining hybrid chemistry with biological interface science are proposed.
Hyperbranched Polymers by Light‐Induced Self‐Condensing Vinyl Polymerization
Authors: Aydogan Cansu , Ciftci Mustafa , Yagci Yusuf
Published: June 2018

Hyperbranched polymers (HBPs), a unique class of dendritic macromolecules, have received continuous interest from macromolecular scientists due to their inherent properties such as high level of functional terminal units, high solubility, and low viscosity. Despite enormous efforts devoted to the synthesis of HBPs by traditional methods such as single and double monomer strategies involving step‐growth polymerization and self‐condensing vinyl polymerization (SCVP) processes, there have been limited attempts to employ light‐induced processes. Photochemical methods, however, exhibit distinct advantages not characteristically disclosed by traditional ones, such as spatial and temporal control, low energy, and site‐specific activation. This review, after a brief summary of the conventional methods, presents the unique features and the key functionalities of the inimers for photoinduced SCVP and strategies for preparing HBPs.
Organic electronics incorporating crown ethers as Na+ binding elements, towards a simple printable hydration sensor
Authors: Holmes Natalie P. , Elkington Daniel C. , Walters Jessica , Nicholson Lee M. , Capozza Mirelle , Magno Maria Hanshella R. , Vijayarajan Shalini , Zhou Xiaojing , Belcher Warwick J. , Dastoor Paul C.
Published: June 2018

Here, we present the development of organic electronic sensors containing crown ethers as ion binding elements for application in Na+ detection for health monitoring. The design, fabrication and characterization of chemiresistor‐based sensors using simple solution processing methods amenable to printing were demonstrated. The analyte testing comprised aqueous solutions of sodium chloride (0, 20, 50, 80 and 130 mM), with the Na+ concentration reflecting the range which occurs in human sweat. The introduction of the crown ether binding sites into the sensors was an iterative process, with three types of molecules trialled. The most effective molecule was found to be poly[(dibenzo‐18‐crown‐6)‐co‐formaldehyde], a polymer which comprises a linked chain of crown ether subunits. The binding of Na+ ions to the crown ether sites of the polymer was measured by comparing the amperometric characteristics of devices without crown ether binding sites (Reference Device) to those with crown ether binding sites (CE Device), following exposure to an analyte solution. For an 80 mM Na+ analyte solution, we observed a sensor response of 116.2 nA (It = 600 s) for the Reference Device (average) reduce to a value of 44.8 nA (It = 600 s) for the CE Device (average). This sensor shows a proof of concept towards low‐cost, solution‐processable sodium ion sensors suitable for mass production on flexible substrates.
Technical Note: An hybrid parallel implementation for EGSnrc Monte Carlo user codes
Authors: Doerner Edgardo , Caprile Paola
Published: June 2018

Purpose

The purpose of this study was to present a parallel solution for the EGSnrc Monte Carlo code system combining MPI and OpenMP programming models as an alternative to the provided implementation, based on the use of a batch‐queueing system (BQS).

Methods

Relying on a previous implementation based on OpenMP by E. Doerner and P. Caprile [Med. Phys. 44, 6672 (2017)], this work incorporates MPI features to efficiently distribute the simulation on current high‐performance computing (HPC) systems. These features are introduced through properly defined macros, which are enabled depending on the compilation flags given by the user. The presented solution was benchmarked using the DOSXYZnrc code for a 6 MV clinical photon beam impinging on an homogeneous water phantom.

Results

The platform validation against the serial run results confirmed that the introduction of new features does not modify the final dose distribution. The performance tests indicated that the new implementation was able to handle efficiently the workload distribution among the computing units available. Using all the resources available, the hybrid simulation was 10% faster than the MPI only solution and 30% faster than the BQS implementation.

Conclusions

The hybrid method presented is a viable solution to parallelize MC simulations using the EGSnrc codes in distributed computing systems in an simple and efficient way, taking advantage of the available resources and giving the user the possibility of choosing between different parallelization schemes (only OpenMP/MPI or a combination of both).
Design of Acrylic Dispersants for Nonaqueous Dispersion Polymerization: The Importance of Thermodynamics
Authors: Zhang Mingmin , Hutchinson Robin A.
Published: June 2018

Poly(acrylic) nanoparticles produced by nonaqueous dispersion (NAD) radical polymerization are important components in many automotive coating formulations. A series of experiments show that the properties of final dispersions (particle size distribution, viscosity, and stability) correlate to the thermodynamics of the NAD system, as characterized by solubility parameters and solubility distances among the continuous phase, the soluble polymeric dispersant, and the polymer particles. The insights gained have enabled the design of a macromonomer dispersant containing greater than 10 mol% 2‐hydroxyethyl methacrylate, a necessary functional comonomer addition for end‐use properties. Stable NAD products were synthesized by changing the principal component of the dispersant from butyl methacrylate to 2‐ethylhexyl methacrylate.
Improving large‐scale implementations by applying research and data analysis: A case study on First 5 LA's implementation of PCIT in Los Angeles County
Authors: Bahng Grace , Taborga Marcia , Bae Christine , Jimenez Armando
Published: June 2018

This paper presents the case of First 5 LA's 5‐year countywide implementation of the Parent–Child Interaction Therapy (PCIT) program. Enthusiasts of PCIT point to it as a high‐quality parenting program with the potential to positively influence child behavior, reduce recidivism into the child welfare system, and increase caregiver's confidence and self‐esteem. In September 2012, First 5 LA, an independent County agency in Los Angeles that advocates on behalf of parents with young children, began a $20 million countywide implementation of PCIT. The collaborative effort between First 5 LA, the Los Angeles County Department of Mental Health, the Los Angeles County Department of Children and Family Services, and the University of California, Davis demonstrates the role that research and data analysis can play in improving large‐scale implementations.

The authors of this paper were contracted to conduct an evaluation of the implementation of the countywide PCIT program, and preliminary outcomes were analyzed after the first round of data collection in early 2015. This paper will discuss this case and provide examples of how research and data analysis were used effectively to make key improvements to the design and implementation of the program. The paper will then discuss bureaucratic challenges and constraints with the collaborative use of research and data. The paper will conclude with some recommendations on how research and data can effectively be used to influence policy implementation in large‐scale implementations involving collaboration among multiple organizations.
Optical analysis of pulse barrier discharge on initiation stages in air
Authors: Khomich Vladislav Yu. , Malashin Maxim V.
Published: June 2018

Experimental results on pulsed dielectric barrier discharge (DBD) initiation stages in air are given in the present work. Pictures of discharge afterglow and current traces from a sectioned electrode were collected and analyzed. The qualitative model of volume nanosecond DBD formation based on combination of well‐known model of self‐sustained gas discharge development together with surface charge spreading from electroscopic data is proposed. Represented qualitative explanation of observed phenomena involve summarized conclusions from cross‐correlation spectroscopy researches, well‐known streamer theory, model of self‐sustained gas discharge development, and dielectric surface charge spreading behavior from electroscopic measurements.
Young's modulus of plasma‐polymerized allylamine films using micromechanical cantilever sensor and laser‐based surface acoustic wave techniques
Authors: Toda Masaya , Miyake Koji , Chu Li‐Qiang , Zakerin Marjan , Förch Renate , Berger Rüdiger , Itakura Akiko N.
Published: June 2018

Mechanical properties of ultra‐thin organic films are fundamentally important in coating applications. Micromechanical cantilever sensor (MCS) and laser‐based surface acoustic wave (LA‐SAW) techniques were both used to measure Young's moduli (E) of plasma polymerized films at different humidities (H). For plasma polymerized allylamine (ppAA) films deposited at 5 W and 90 W, E of 1400 ± 350 MPa and 110 ± 20 MPa at H between 10 and 40%, and 1070 ± 250 MPa and 32 ± 10 MPa at H between 70 and 80% were measured. The LA‐SAW technique revealed E lower than 60% of that measured by MCS. The difference suggested either an enhanced swelling at the air interface or a gradient of cross‐linking density.
Molecular characterization and functional analysis of pheromone binding proteins and general odorant binding proteins from Carposina sasakii Matsumura (Lepidoptera: Carposinidae)
Authors: Tian Zhiqiang , Qiu Guisheng , Li Yanyan , Zhang Huaijiang , Yan Wentao , Yue Qiang , Sun Lina
Published: June 2018

BACKGROUND

The peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae), is one of the most destructive pests of pome and stone fruits, while few studies of their molecular biology and physiology have been conducted. Research into CsasPBPs (Carposina sasakii pheromone binding proteins) and CsasGOBPs (Carposina sasakii general odorant binding proteins) may provide insights in to the mechanisms of olfaction in Carposina sasakii.

RESULTS

In our study, results of real time quantitative polymerase chain reaction (qPCR) assays demonstrated that CsasPBP1–3 and CsasGOBP1–2 transcripts were abundantly expressed in the antennae of both sexes, suggesting they play a vital role in olfaction. In addition, to examine specific functional differences between pheromone binding proteins (PBPs) and general odorant binding proteins (GOBPs), fluorescence competitive binding assays were used to measured the binding affinities for the two sex pheromones and 18 apple plant volatiles. As a result, both PBPs and GOBPs showed stronger binding affinities to Z‐7‐eicosene‐11‐one than Z‐7‐nonadecene‐11‐one in two sex pheromones, whereas only PBP3 exhibited specific affinity towards both these two sex pheromone components, and PBP1 showed a high binding affinity to the sex pheromone components, and to other plant volatiles. In addition, GOBP1–2 displayed high binding affinity to general components of plant volatiles.

CONCLUSION

Our study suggested CsasPBPs and CsasGOBPs play distinct physiological roles in the perception of sex pheromones and host plant volatiles. © 2018 Society of Chemical Industry
Improvement of Thermoelectricity Through Magnetic Interactions in Layered Cr2Ge2Te6
Authors: Peng Chengxiao , Zhang Guangbiao , Wang Chao , Yan Yuli , Zheng Haiwu , Wang Yuanxu , Hu Ming
Published: June 2018

The magnetism is proposed as a way to improve thermoelectricity, which may overcome the tradeoff between electrical conductivity and Seebeck coefficient. The correlation between magnetic configurations and thermoelectricity in layered magnetic semiconductor Cr2Ge2Te6 has been investigated using first‐principles calculations, combined with semi‐classical Boltzmann theory. The electronic structures and relevant transport properties for paramagnetic phase have been stimulated. Special quasi‐random structure (SQS) is employed to simulate electronic properties of paramagnetic state corresponding to spin‐disordered configurations. The temperature dependence of calculated Seebeck coefficient, electrical conductivity, and the figure of merit ZT is in good agreement with experimental values for paramagnetic phase. For p‐type Cr2Ge2Te6, the maximum ZT can reach 0.54 at 830 K and the carrier concentration a value of 2.1 × 1020 cm−3. The calculated figure of merit can further increase by 42% compared to the maximum experimental result by optimized doping level. Cr2Ge2Te6 without spin polarization shows a metal electric band structure, which deviates from the semiconductor of truth. This means that magnetic interactions play an important role in electronic structure and result in an excellent thermoelectricity of paramagnetic Cr2Ge2Te6. High band valley degeneracy, flat valence bands, and the localized partial density of states (PDOS) of magnetic atoms near Fermi surface induce a large Seebeck coefficient, meanwhile a good electrical conductivity is maintained in this magnetic semiconductor with high symmetry.
Two CUSUM schemes for simultaneous monitoring of parameters of a shifted exponential time to events
Authors: Huang Shuo , Mukherjee Amitava , Yang Jun
Published: June 2018

Two‐parameter (shifted) exponential distribution is widely applied in many areas such as reliability modeling and analysis where time to failure is protected by a guaranty period that induces an origin parameter in the exponential model. Despite a large volume of works on inferential aspects of two‐parameter exponential distribution, only few studies are done from the perspective of process monitoring. In the modern production process, where items come with a warranty, we often encounter shifted‐exponential time between events from consumers' perspective, and therefore, in this paper, we propose two CUSUM schemes for joint monitoring of the origin and scale parameters based on the Maximum Likelihood estimators. We study the in‐control behavior of the proposed procedures via Markov chain approach as well as applying Monte Carlo. We provide detailed implementation strategies of the two schemes along with the follow‐up procedures to identify the source of shifts when an out‐of‐control signal is obtained. We examine the performance properties of CUSUM schemes and find that the two proposed schemes offer performance advantages over the Shewhart‐type schemes especially for monitoring small to moderate shifts. Further, we provide some guidance for choosing the appropriate schemes and study the effect of reference parameter k of the CUSUM schemes. We also investigate the optimal design of reference values both in known and unknown shift cases. Finally, two examples are given to illustrate the implementation of the proposed approach.
A single‐index threshold Cox proportional hazard model for identifying a treatment‐sensitive subset based on multiple biomarkers
Authors: He Ye , Lin Huazhen , Tu Dongsheng
Published: June 2018

In this paper, we introduce a single‐index threshold Cox proportional hazard model to select and combine biomarkers to identify patients who may be sensitive to a specific treatment. A penalized smoothed partial likelihood is proposed to estimate the parameters in the model. A simple, efficient, and unified algorithm is presented to maximize this likelihood function. The estimators based on this likelihood function are shown to be consistent and asymptotically normal. Under mild conditions, the proposed estimators also achieve the oracle property. The proposed approach is evaluated through simulation analyses and application to the analysis of data from two clinical trials, one involving patients with locally advanced or metastatic pancreatic cancer and one involving patients with resectable lung cancer.
Halloysite Nanotubes Templated Acid‐Base Bi‐functional Hollow Polymeric Solids for Select Conversion of Cellulose to 5‐Hydroxymethylfurfural
Authors: Zhang Yunlei , Liu Meng , Zhao Jiaojiao , Wang Kai , Meng Minjia , Yan Yongsheng
Published: June 2018

Due to its excellent catalytic performance, low production of waste and easy recyclability, heterogeneous catalysts employed for conversion of cellulose to HMF have been drawn wide attention in recent years. In this work, precipitation polymerization methodology, subsequent template remove, and the sulfonation technique are combined to synthesis hollow polymeric solid catalysts with tunable acid‐base bi‐functional sites. By simply varying the parameters of precipitation polymerization, the acid and base strengths can be easily adjusted. The catalytic performances of synthesized catalysts were evaluated for 5‐hydroxymethylfurfural (HMF) production from cellulose conversion in ionic liquid of 1‐butyl‐3‐methylimidazolium chloride ([BMIM]‐Cl). And 41.63% of HMF yield can be obtained under the optional conditions. Furthermore, catalyst can be easily recovered and reused at least five times without significant loss of activity. This research opens up a versatile method to synthesize multifunctional catalyst for excellent conversion of one‐pot cellulose to HMF.
Gender, entrepreneurial characteristics, and success: Evidence from Ethiopia
Authors: Mersha Tigineh , Sriram Ven
Published: June 2018

Africa‐based research on gender and entrepreneurship is very limited. This study compares the characteristics and relative successes of men and women entrepreneurs in Ethiopia with a view of isolating the unique hurdles encountered by female entrepreneurs. While both genders in this sample were pulled, rather than pushed, toward entrepreneurship, women were more influenced by family factors. With regard to personality traits, men entrepreneurs in this study were generally more confident in their ability to succeed, whereas women exhibited higher fear of failure and external locus of control. Women entrepreneurs also reported lower business and entrepreneurial skills and relied more on government funding. Furthermore, male entrepreneurs outperformed females in terms of sales, employment growth, and profitability. The study identifies areas in which the skills and competencies of Ethiopian women entrepreneurs can be developed through targeted training programs to enable them to more clearly recognize entrepreneurial opportunities and achieve business growth. The findings of this study and the concrete suggestions it offers to strengthen the success of Ethiopian women entrepreneurs may be relevant to other African countries as well.
International joint ventures research on Africa: A systematic literature review, propositions, and contextualization
Authors: Oguji Nnamdi , Degbey William Y. , Owusu Richard A.
Published: June 2018

This study reviewed the research on international joint ventures (IJVs) in Africa up to 2017. The authors performed a systematic search of peer‐reviewed good‐quality research using the 6W procedure and ensured the quality of the review by using the 5Cs quality criteria. The content analysis was focused on four research questions. A total of 22 relevant studies were found. Overall, only about one‐third of the lead authors were affiliated with African universities. A majority of the studies were quantitative, and 78% of the studies were done for three countries: Ghana, Morocco, and Nigeria. There was either just one or no study on trust and conflict, partner selection, and human resource management (HRM). At the contextual level, it seems the most important factor influencing IJV strategy and success is institutions. We therefore suggest a greater use of institutional theory. Finally, we present a summary of conceptual framework and four propositions to guide future research.
Global M&A: Still the chocolate industry sweetspot?
Authors: Allen Lawrence
Published: June 2018

Like a dividing cell under the microscope, the American snack food market has split apart into two distinct cells, each with its own unique consumer DNA. The two market segments can best be defined as legacy consumers and next‐generation consumers. This tectonic shift in the confectionery industry may make global industry‐giant mergers more a battle between dinosaurs, lit by meteor light.
PolyA tracks, polybasic peptides, poly‐translational hurdles
Authors: Arthur Laura L. , Djuranovic Sergej
Published: June 2018

The abundance of messenger RNA (mRNA) is one of the major determinants of protein synthesis. As such, factors that influence mRNA stability often contribute to gene regulation. Polyadenylation of the 3′ end of mRNA transcripts, the poly(A) tail, has long been recognized as one of these regulatory elements given its influence on translation efficiency and mRNA stability. Unwanted translation of the poly(A) tail signals to the cell an aberrant polyadenylation event or the lack of stop codons, which makes this sequence an important element in translation fidelity and mRNA surveillance response. Consequently, investigations into the effects of the poly(A) tail lead to the discoveries that poly‐lysine as well as other polybasic peptide sequences and, to a much greater extent, polyA mRNA sequences within the open reading frame influence mRNA stability and translational efficiency. Conservation and evolutionary selection of codon usage in polyA track sequences across multiple organisms suggests a biological significance for coding polyA tracks in the regulation of gene expression. Here, we discuss the cellular responses and consequences of coding polyA track translation and synthesis of polybasic peptides.

This article is categorized under:

Translation > Translation Mechanisms

Translation > Translation Regulation

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms
The next-to-next-to-leading order soft function for top quark pair production
Authors: Wang Guoxing , Xu Xiaofeng , Yang Li Lin , Zhu Hua Xing
Published: June 2018

Abstract

We present the first calculation of the next-to-next-to-leading order threshold soft function for top quark pair production at hadron colliders, with full velocity dependence of the massive top quarks. Our results are fully analytic, and can be entirely written in terms of generalized polylogarithms. The scale-dependence of our result coincides with the well-known two-loop anomalous dimension matrix including the three-parton correlations, which at the two-loop order only appear when more than one massive partons are involved in the scattering process. In the boosted limit, our result exhibits the expected factorization property of mass logarithms, which leads to a consistent extraction of the soft fragmentation function. The next-to-next-to-leading order soft function obtained in this paper is an important ingredient for threshold resummation at the next-to-next-to-next-to-leading logarithmic accuracy.
Nonlocal vertices and analyticity: Landau equations and general Cutkosky rule
Authors: Chin Paokuan , Tomboulis E. T.
Published: June 2018

Abstract

We study the analyticity properties of amplitudes in theories with nonlocal vertices of the type occurring in string field theory and a wide class of nonlocal field theory models. Such vertices are given in momentum space by entire functions of rapid decay in certain (including Euclidean) directions ensuring UV finiteness but are necessarily of rapid increase in others. A parametric representation is obtained by integrating out the loop (Euclidean) momenta after the introduction of generalized Schwinger parameters. Either in the original or parametric representation, the well-defined resulting amplitudesare then continued in the complex space of the external momenta invariants. We obtain the alternative forms of the Landau equations determining the singularity surfaces showing that the nonlocal vertices serve as UV regulators but do not affect the local singularity structure. As a result the full set of singularities known to occur in local field theory also occurs here: normal and anomalous thresholds as well as acnodes, crunodes, and cusps that may under certain circumstances appear even on the physical sheet. Singularities of the second type also appear as shown from the parametric representation. We obtain the general Cutkosky discontinuity rule for encircling a singularity by employing contour deformations only in the finite plane. The unitarity condition (optical theorem) is thendiscussed as a special application of the rule across normal thresholds and the hermitian analyticity property of amplitudes.
On some universal features of the holographic quantum complexity of bulk singularities
Authors: Bolognesi Stefano , Rabinovici Eliezer , Roy Shubho R.
Published: June 2018

Abstract

We perform a comparative study of the time dependence of the holographic quantum complexity of some space like singular bulk gravitational backgrounds. This is done by considering the two available notions of complexity, one that relates it to the maximal spatial volume and the other that relates it to the classical action of the Wheeler-de Witt patch. We calculate and compare the leading and the next to leading terms and find some universal features. The complexity decreases towards the singularity for both definitions, for all types of singularities studied. In addition the leading terms have the same quantitative behavior for both definitions in restricted number of cases and the behaviour itself is different for different singular backgrounds. The quantitative details of the next to leading terms, such as their specific form of time dependence, are found not to be universal. They vary between the different cases and between the different bulk definitions of complexity. We also address some technical points inherent to the calculation.
On Bethe vectors in $$ \mathfrak{g}{\mathfrak{l}}_3 $$-invariant integrable models
Authors: Liashyk A. , Slavnov N. A.
Published: June 2018

Abstract

We consider quantum integrable models solvable by the nested algebraic Bethe ansatz and possessing

$$ \mathfrak{g}{\mathfrak{l}}_3 $$

g

l
3

-invariant R-matrix. We study a new recently proposed approach to construct on-shell Bethe vectors of these models. We prove that the vectors constructed by this method are semi-on-shell Bethe vectors for arbitrary values of Bethe parameters. They thus do become on-shell vectors provided the system of Bethe equations is fulfilled.
Holographic duals of 3d S-fold CFTs
Authors: Assel Benjamin , Tomasiello Alessandro
Published: June 2018

Abstract

We construct non-geometric AdS4 solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called T [U(N)] theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function Z of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d

$$ \mathcal{N}=4 $$

N
=
4

SCFTs; for these we manage to compute Z of the dual CFT at finite N, and it agrees perfectly with the supergravity result in the large N limit. A second class has five-branes, it is obtained by a Möbius-like S-quotient of ordinary compact solutions and is dual to 3d

$$ \mathcal{N}=3 $$

N
=
3

SCFTs. For these, Z agrees with the supergravity result if one chooses the limit carefully so that the effect of the fivebranes does not backreact on the entire geometry. Other limits suggest the existence of IIA duals.
Left ventricular function and mechanics following prolonged
endurance exercise: an update and meta-analysis with insights from novel
techniques
Authors: Lord Rachel N. , Utomi Victor , Oxborough David L. , Curry Bryony A. , Brown Megan , George Keith P.
Published: June 2018

Background

The cardiac consequences of undertaking endurance exercise are the topic of
recent debate. The purpose of this review is to provide an update on a growing
body of literature, focusing on left ventricular (LV) function following
prolonged endurance exercise over 2 h in duration which have employed novel
techniques, including myocardial speckle tracking, to provide a more
comprehensive global and regional assessment of LV mechanics.

Methods

Prospective studies were filtered independently following a pre-set criteria,
resulting in the inclusion of 27 studies in the analyses. A random-effects
meta-analysis was used to determine the weighted mean difference and 95%
confidence intervals (CI) of LV functional and mechanical data from
pre-to-post-exercise. Narrative commentary was also provided where volume of
available evidence precluded meta-analysis.

Results

A significant overall reduction in LV longitudinal strain (Ɛ) n = 22
(− 18 ± 1 to − 17 ± 1%; effect size (d) − 9:
− 1 to − 0.5%), strain rate n = 10 (SR;d − 0.9: − 0.1.3 to − 0.5 l/s) and twistn = 5 (11.9 ± 2.2 to 8.7 ± 2.2°,d − 1: − 1.6 to − 0.3°) was observed
following strenuous endurance exercise (range 120–1740 min) (P < 0.01). A smaller number of studies
(n = 4) also reported a non-significant
reduction in global circumferential and radial Ɛ (P > 0.05).

Conclusion

The meta-analysis and narrative commentary demonstrated that a reduction in LV
function and mechanics is evident following prolonged endurance exercise. The
mechanism(s) responsible for these changes are complex and likely
multi-factorial in nature and may be linked to right and left ventricular
interaction.
Continence changes following transanal endoscopic microsurgery result from the impact on rectal capacity: clinical and functional evaluation before and after surgical treatment
Authors: Mendes Carlos Ramon Silveira , Araujo Sergio Eduardo Alonso , Perez Rodrigo , Cecconello Ivan , DÁlbuquerque Luiz Augusto Carneiro
Published: June 2018

Introduction Described in 1983 and with a stable clinical application, the impact of Transanal Endoscopic Microsurgery on anorectal function remains unknown. The objectives of the present study were to evaluate the impact of Transanal Endoscopic Microsurgery on anorectal function according to clinical (Wexner score) and functional (anorectal manometry) evaluations before and after surgery.

Method Prospectively, 23 consecutive patients with rectal lesions were operated using TEO® equipment (Karl Storz, Tuttlingen, Germany). For all patients, the value of Wexner score was obtained before and after surgery (7, 30 and 90 days) and anorectal electromanometry was performed before surgery, and also postoperatively (30 and 90 days).

Results Fourteen patients were men. The mean age was 53.7 (24–81) years. The mean distance from the lesion to the pectineal line was 7 (2–15) cm. The histopathologic analysis revealed adenoma in 14 (61%); neuroendocrine tumor in 5 (21.7%); invasive carcinoma in 3 (13%); and hyperplastic polyp in 1 (4.3%) case. The mean duration of postoperative follow-up was 5 (3–7) months. Wexner score was significantly lower at 30 days compared to 7 days (Wilcoxon; p = 0.03). Rectal capacity was significantly lower 30 days after surgery and recovered at 90 days of surgery (ANOVA; p = 0.04).

Conclusions After Transanal Endoscopic Microsurgery, a modest impact on anorectal function can be observed. The transient impairment results from loss of rectal capacity and not from impairment of the anal sphincters, being completely resolved 90 days after surgery.