bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensure the marketplace of ideas stays open: Free speech on campus
Authors: Sutton Halley
Published: April 2018

WASHINGTON, D.C. — Free speech is not only an important backbone of American democracy but also an important piece of higher education: Students grow by exposure to points of view that differ from their own. But free speech can also create contentious moments on your campus, with emotions running high. To facilitate free speech, you need a plan for how to deal with all the possibilities, as well as ensure the safety of students, who do have the right to protest speakers.
Mitral valve interventions in heart failure
Authors: Lavall Daniel , Hagendorff Andreas , Schirmer Stephan H. , Böhm Michael , Borger Michael A. , Laufs Ulrich
Published: April 2018

Secondary mitral regurgitation (MR) results from left ventricular dilatation and dysfunction. Quantification of secondary MR is challenging because of the underlying myocardial disease. Clinical and echocardiographic evaluation requires a multi‐parametric approach. Severe secondary MR occurs in up to one‐fourth of patients with heart failure with reduced ejection fraction, which is associated with a mortality rate of 40% to 50% in 3 years. Percutaneous edge‐to‐edge mitral valve repair (MitraClip) has emerged as an alternative to surgical valve repair to improve symptoms, functional capacity, heart failure hospitalizations, and cardiac haemodynamics. Further new transcatheter strategies addressing MR are evolving. The Carillion, Cardioband, and Mitralign devices were designed to reduce the annulus dilatation, which is a frequent and important determinant of secondary MR. Several transcatheter mitral valve replacement systems (Tendyne, CardiAQ‐Edwards, Neovasc, Tiara, Intrepid, Caisson, HighLife, MValve System, and NCSI NaviGate Mitral) are emerging because valve replacement might be more durable compared with valve repair. In small studies, these interventional therapies demonstrated feasibility and efficiency to reduce MR and to improve heart failure symptoms. However, neither transcatheter nor surgical mitral valve repair or replacement has been proven to impact on the prognosis of heart failure patients with severe MR, which remains high with a mortality rate of 14–20% at 1 year. To date, the primary indication for treatment of secondary severe MR is the amelioration of symptoms, reinforcing the value of a Heart Team discussion. Randomized studies to investigate the treatment effect and long‐term outcome for any transcatheter or surgical mitral valve intervention compared with optimized medical treatment are urgently needed and underway.
Synthesis, Structure, and Water Oxidation Activity of Ruthenium(II) Complexes: Influence of Intramolecular Redox Process on O2 Evolution
Authors: Dhiman Rekha , Nagaraja C. M.
Published: April 2018

The synthesis and characterization of two new RuII complexes, a mononuclear complex [RuII(MeMPTP)(bpp)Cl]PF6 (1) and a dinuclear complex [RuII(MeMPTP)(bpp)RuII(bpy)2Cl](PF6)3 (2), [where MeMPTP = 4′‐(4‐methylmercaptophenyl)‐2,2′:6′2′′‐terpyridine, bpp = 2,3‐bis(2‐pyridyl)pyrazine, bpy = 2,2′‐bipyridine] is reported. Single‐crystal X‐ray structural determination of the compounds unambiguously confirms the formation of the complexes 1 and 2. Catalytic investigations of the complexes for the chemical oxidation of water in the presence of Ce4+ as a sacrificial oxidant reveals a higher rate of O2 evolution by the dinuclear complex 2 over the physical mixture of complex 1 and a redox mediator, [Ru(bpy)3]2+ (med), followed by the mononuclear complex 1. The enhancement in the catalytic rate of O2 evolution by 2 is ascribed to being due to the intramolecular redox process, which facilitates the facile formation of a high‐valent ruthenium–oxo species that is required for water oxidation through a cooperative effect. The present study highlights the importance of the intramolecular redox process over the intermolecular redox process.
Modification of a Copper‐Based Metal–Organic Framework with Graphene Oxide for the Removal of Sulfur Compounds
Authors: Zhang Hong‐Yan , Shi Rui‐Hua , Zhang Zhen‐Rong , Zhou Chang‐Hai , Yang Chao , Fan Hui‐Ling , Wu Meng‐Meng
Published: April 2018

Copper‐based metal–organic framework/graphene oxide (MOF‐199/GO) composites were prepared under hydrothermal conditions. The adsorption performances of the composites for CH3SCH3 and CH3CH2SH removal under ambient conditions were evaluated. The materials were characterized by XRD, FTIR spectroscopy, nitrogen adsorption/desorption, scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). The composites exhibit a unique layered structure. MGO‐1 with 5 % GO shows a higher surface area than that of pristine MOF‐199 owing to the creation of new pores between the MOF‐199 and GO units. MGO‐1 has the best adsorption capacities for CH3SCH3 and CH3CH2SH, and the uptake reaches 6.12 and 4.31 %, respectively, because of the increased surface area and dispersive forces in the new pores. During the adsorption of CH3CH2SH, a chemical reaction results in the destruction of the MOF structure. However, reversible chemisorption was found for CH3SCH3 removal, as testified by fixed‐bed regeneration. Multiple adsorption/regeneration cycles show that the MGO composites are promising adsorbents for CH3SCH3 removal.
Thermochemistry of a Cobalt Complex with Ionisable Pyrazole Protons
Authors: Wilken Mona , Würtele Christian , Kügler Merle , Chrobak Frank , Siewert Inke
Published: April 2018

Herein, we present the thermodynamic analysis of a cobalt complex with a new pentadentate N‐donor ligand bearing four ionisable pyrazole protons in aqueous solution. A detailed analysis of the CoII complex [Co(L)(X)]+/2+ in the solid state revealed that the 6th ligand X at the metal centre depends on the cobalt source employed. Small anions such as Cl– and NO3– coordinate to the metal ion, while larger anions that are weaker hydrogen‐bond acceptors are found in the second coordination sphere of the complex and instead a solvent molecule coordinates. However, in aqueous KCl solution, the sixth ligand is always chloride forming [Co(L)Cl]Cl, 1Cl. pH dependent species distribution studies revealed a pKa of 7.3(3) for the first ionisable pyrazole proton in the cobalt(II) complex and 6.0(3) in the cobalt(III) complex (methanol/H2O mixture). That is the oxidation state has a fairly minor influence on the pKa of the pyrazole proton. The CoIII/CoII redox pair of the complex with the fully protonated ligand exhibits a potential of 0.78 V vs. NHE. The BDFE of the hypothetical H‐atom abstraction step of [CoII(L)Cl]+ forming [CoIII(LH–1)Cl]+ was determined to equal 336 kJ mol–1.
Determination of antidepressants in human urine extracted by magnetic multiwalled carbon nanotube poly(styrene‐co‐divinylbenzene) composites and separation by capillary electrophoresis
Authors: Murtada Khaled , de Andrés Fernando , Ríos Angel , Zougagh Mohammed
Published: April 2018

Poly(styrene‐co‐divinylbenzene)‐coated magnetic multiwalled carbon nanotube composite synthesized by in‐situ high temperature combination and precipitation polymerization of styrene‐co‐divinylbenzene has been employed as a magnetic sorbent for the solid phase extraction of antidepressants in human urine samples. Fluoxetine, venlafaxine, citalopram and sertraline were, afterwards, separated and determined by capillary electrophoresis with diode array detection. The presence of magnetic multiwalled carbon nanotubes in native poly(styrene‐co‐divinylbenzene) not only simplified sample treatment but also enhanced the adsorption efficiencies, obtaining extraction recoveries higher than 89.5% for all analytes. Moreover, this composite can be re‐used at least ten times without loss of efficiency and limits of detection ranging from 0.014 to 0.041 μg/mL were calculated. Additionally, precision values ranging from 0.08 to 7.50% and from 0.21 to 3.05% were obtained for the responses and for the migration times of the analytes, respectively.
Recent trends in sorption‐based sample preparation and liquid chromatography techniques for food analysis
Authors: V. Soares Maciel Edvaldo , de Toffoli Ana Lúcia , Lanças Fernando Mauro
Published: April 2018

The accelerated rising of the world's population increased the consumption of food, thus demanding more rigors in the control of residue and contaminants in food–based products marketed for human consumption. In view of the complexity of most food matrices, including fruits, vegetables, different types of meat, beverages, among others, a sample preparation step is important to provide more reliable results when combined with HPLC separations. An adequate sample preparation step before the chromatographic analysis is mandatory in obtaining higher precision and accuracy in order to improve the extraction of the target analytes, one of the priorities in analytical chemistry. The recent discovery of new materials such as ionic liquids, graphene‐derived materials, molecularly imprinted polymers, restricted access media, magnetic nanoparticles, and carbonaceous nanomaterials, provided high sensitivity and selectivity results in an extensive variety of applications. These materials, as well as their several possible combinations, have been demonstrated to be highly appropriate for the extraction of different analytes in complex samples such as food products. The main characteristics and application of these new materials in food analysis will be presented and discussed in this paper. Another topic discussed in this review covers the main advantages and limitations of sample preparation microtechniques, as well as their off‐line and on‐line combination with HPLC for food analysis.
Concurrent determination and separation of inorganic cations and anions in microchip electrophoresis with precisely controlled high‐voltage
Authors: Huang Zhe , Yang Mingpeng , You Hui , Xie Yang
Published: April 2018

An improved method for the concurrent determination and separation of cations and anions by microchip electrophoresis with capacitively coupled contactless conductivity detection (ME‐C4D) is described. Two kinds of microchip structures were designed. The first microchip has a long bent separation channel. And for the defects of the first microchip, the second microchip with a Y‐type separation channel has been proposed. The background electrolyte (BGE) composed of 20 mm His/MES and 0.01 mm CTAB was optimized for inhibiting the electroosmotic flow (EOF). Due to the low electroosmotic flow, the cations and anions migrate in opposite directions and can be separated from each other. With the precisely controlled high‐voltage, cations and anions can be migrated in microchannels according to our requirements and sequentially detected by a C4D detector built in‐house. Samples containing K+, Na+, Li+, Cl−, F− and PO43− were analyzed simultaneously in a single run (within 140 s) by both methods. The reproducibility obtained by both methods remained below 5% for migration time and within 3.5–9.1% for peak areas. The proposed concurrent determination methods are inexpensive, simple, fast, ease of operation, high degree of integration.
Direct Measurement of the Electrocaloric Temperature Change in Multilayer Ceramic Components using Resistance‐Welded Thermocouple Wires
Authors: Greiner Anna , Molin Christian , Neubert Holger , Gebhardt Sylvia E. , Neumeister Peter
Published: April 2018

A method for direct measurement of the adiabatic temperature change inside the active region of multilayer ceramic (MLC) components without detailed knowledge on geometry and properties of inactive regions in the MLC is reported. Thin thermocouple wires serve as the temperature sensor with sufficiently small response time with regard to the relaxation time into the inactive regions. They are mounted on top of the MLC by resistance welding. The accuracy of the method is estimated using finite element analyses of the measuring setup. Experiments are used to validate the numerical analyses as well as the proposed measuring method. In its current implementation the method reaches an accuracy of almost 90 %, which can be improved to approximately 97 %. Therefore, neither fitting nor correction is required.
BaZrxTi1−xO3 Epitaxial Thin Films for Electrocaloric Investigations
Authors: Engelhardt Stefan , Molin Christian , Gebhardt Sylvia , Fähler Sebastian , Nielsch Kornelius , Hühne Ruben
Published: April 2018

Epitaxial BaZrxTi1−xO3 (BZT) thin films with a Zr content between x=0 and x=0.3 are grown by pulsed laser deposition on (001)‐oriented SrTiO3 single crystals utilizing a conducting SrRuO3 buffer layer and Pt top electrodes. An undisturbed epitaxial growth with a smooth and homogeneous surface structure is obtained for all Zr containing films, whereas some preferentially growing grains and twins are observed for pure BaTiO3 films. Temperature‐dependent measurements of the relative permittivity suggest a diffuse phase transition. The temperature of the maximum permittivity as well as the electrical polarizability at room temperature decrease with increasing Zr content. The observed frequency dependence suggests relaxor ferroelectric properties for all Zr‐containing films. The indirectly determined electrocaloric responses are considerably lower compared to thick films, which is primarily attributed to the diffuse character of the phase transition. A maximum adiabatic temperature change of about 0.3 K for an electric field change of 170 kV cm−1 is found for BaZr0.2Ti0.8O3.
Building service life economic loss assessment under sequential seismic events
Authors: Shokrabadi Mehrdad , Burton Henry V.
Published: April 2018

Aftershocks have been shown to exacerbate earthquake‐induced financial losses by causing further damage to structural and nonstructural components in buildings that have already been affected by a mainshock event and increasing the duration of disrupted functionality. Whereas seismic loss assessment under isolated events has been addressed thoroughly in previous studies, comparatively less has been accomplished in the area of loss assessment under sequences of mainshock‐aftershock ground motions. The main objective of the current study is to formulate a comprehensive framework for quantifying financial losses under sequential seismic events. The proposed framework is capable of accounting for the uncertainties in the state of structure due to accumulation of earthquake‐induced damage, the time‐dependent nature of seismic hazard in the post‐mainshock environment, and the uncertainties in the occurrence of mainshock and aftershock events. Application of the proposed framework to a 4‐story reinforced concrete moment frame shows that consideration of aftershocks could increase lifecycle earthquake‐induced losses by up to 30% compared with mainshock‐only assessments.
Core networks and their reconfiguration patterns across cognitive loads
Authors: Zuo Nianming , Yang Zhengyi , Liu Yong , Li Jin , Jiang Tianzi
Published: April 2018

Different cognitively demanding tasks recruit globally distributed but functionally specific networks. However, the configuration of core networks and their reconfiguration patterns across cognitive loads remain unclear, as does whether these patterns are indicators for the performance of cognitive tasks. In this study, we analyzed functional magnetic resonance imaging data of a large cohort of 448 subjects, acquired with the brain at resting state and executing N‐back working memory (WM) tasks. We discriminated core networks by functional interaction strength and connection flexibility. Results demonstrated that the frontoparietal network (FPN) and default mode network (DMN) were core networks, but each exhibited different patterns across cognitive loads. The FPN and DMN both showed strengthened internal connections at the low demand state (0‐back) compared with the resting state (control level); whereas, from the low (0‐back) to high demand state (2‐back), some connections to the FPN weakened and were rewired to the DMN (whose connections all remained strong). Of note, more intensive reconfiguration of both the whole brain and core networks (but no other networks) across load levels indicated relatively poor cognitive performance. Collectively these findings indicate that the FPN and DMN have distinct roles and reconfiguration patterns across cognitively demanding loads. This study advances our understanding of the core networks and their reconfiguration patterns across cognitive loads and provides a new feature to evaluate and predict cognitive capability (e.g., WM performance) based on brain networks.
Fall prevention in central coast community pharmacies
Authors: Stuart Gina M. , Kale Helen L.
Published: April 2018

Issue addressed

Fall injuries among people aged 65 years and over (older people) cause substantial health decline and cost to the health system. In 2009 in New South Wales, 25.6% of older people fell in the previous year, and 10.7% (32 000) were hospitalised. Pharmacists are trusted professionals, who interact extensively with older people and have potential to augment fall prevention in pharmacies. This brief report describes how professional development improved pharmacist's knowledge and confidence in fall prevention, encouraged implementation of fall prevention plans and facilitated the provision of brief fall prevention interventions for older clients, after identification of fall risk.

Methods

In 2014, pharmacists from all Central Coast pharmacies (n = 76) were invited to free, continuing professional development (CPD) in fall prevention. It provided education and resources to identify clients’ fall risk, conduct brief fall prevention interventions and implement fall prevention health promotion plans (FPHPP). Pharmacists completed written:

Baseline and postworkshop questionnaires to assess changes in pharmacist's knowledge and confidence, and existing fall prevention in pharmacies.

Logs of client fall risk and brief fall prevention interventions offered to clients.

Four‐month follow‐up questionnaires to assess implementation of FPHPPs and pharmacy practice changes.

Results

Pharmacists representing 36% of pharmacies participated. At four‐month follow‐up, 67% had implemented FPHPPs, and 62% delivered brief interventions determined by client fall risk.

Conclusion

Fall prevention in pharmacies can be augmented through locally provided CPD tailored for pharmacists.

So what?

This model could increase fall prevention reach. It is transferable to settings where health professionals provide services to older adults and require reregistration through professional development.
Towards low‐cost community networks in rural communities: The impact of context using the case study of Beitbridge, Zimbabwe
Authors: Gwaka Leon Tinashe , May Julian , Tucker William
Published: April 2018

Most rural communities in developing countries such as Zimbabwe are underserved and/or unserved with regard to telecommunication connectivity. Governments in developing countries are also under‐resourced to provide adequate digital infrastructure. Thus, community networks are increasingly seen as viable alternatives to bridge the infrastructure gap in Africa. However, new infrastructure interventions in developing countries face many challenges including complex interventions stemming from complex policies inserted into complex sociopolitical environments. The success of community networks in other African countries prompts this investigation into the potential of transferring the community network approach to Zimbabwe. The objective of this article is to frame how context impacts development of digital infrastructure. Zimbabwe's telecommunication regulatory framework is on the verge of countenancing the development of community networks, and for this reason, there is need for research to inform would‐be investors, policy makers, and other stakeholders such as academia, NGOs, and communities themselves, on how the sociopolitical and economic environment impact these efforts. This is important because successful deployment of a community network may result in improved community development, eg, in food security, health, and education.
Using an abbreviated assessment to identify effective error‐correction procedures for individual learners during discrete‐trial instruction
Authors: Carroll Regina A. , Owsiany Jennifer , Cheatham Jessica M.
Published: April 2018

Previous research comparing the effectiveness of error‐correction procedures has involved lengthy assessments that may not be practical in applied settings. We used an abbreviated assessment to compare the effectiveness of five error‐correction procedures for four children with autism spectrum disorder or a developmental delay. During the abbreviated assessment, we sampled participants' responding with each procedure and completed the assessment before participants reached our mastery criterion. Then, we used the results of the abbreviated assessment to predict the most efficient procedure for each participant. Next, we conducted validation assessments, comparing the number of sessions, trials, and time required for participants to master targets with each procedure. Results showed correspondence between the abbreviated assessment and validation assessments for two of four participants and partial correspondence for the other two participants. Findings suggest that a brief assessment may be a useful tool for identifying the most efficient error‐correction procedure for individual learners.
Probing endogenous collagen by laser‐induced autofluorescence in burn wound biopsies: A pilot study
Authors: Prabhu Vijendra , Acharya Anusha , Satish Rao Bola S. , Rathnakar Bharath , Kumar Pramod , Guddattu Vasudeva , Mahato Krishna K.
Published: April 2018

The focus of the current study was to interrogate the predictive potential of laser‐induced autofluorescence (LIAF) by objectively assessing collagen synthesis in burn wound granulation tissues ex vivo. Prior grafting, granulation tissues (20 samples) following burn injury were collected from 17 subjects of age range 18 to 60 years with patient/donor consent and the corresponding autofluorescence spectra were recorded at 325 nm He‐Cd laser (≈2 mW) excitations. The resulting endogenous collagen intensity from the above tissue samples was computed by normalizing the nicotinamide adenine dinucleotide levels. In addition, the hydroxyproline content was also estimated biochemically from the same granulation tissues. A comparative assessment of both LIAF and biochemical estimations for endogenous collagen by hydroxyproline resulted in strong positive correlation among them. The above relevant observations suggest that LIAF is equally informative as that of biochemical estimations, in evaluating endogenous collagen content in wound granulation tissues. Thus, it can be concluded that LIAF has the predictive potential, as a noninvasive objective tool to measure the endogenous collagen levels in wound biopsy tissues and provide complementary data conducive for making clinical decisions.
Associations of pre‐existing co‐morbidities with skeletal muscle mass and radiodensity in patients with non‐metastatic colorectal cancer
Authors: Xiao Jingjie , Caan Bette J. , Weltzien Erin , Cespedes Feliciano Elizabeth M. , Kroenke Candyce H. , Meyerhardt Jeffrey A. , Baracos Vickie E. , Kwan Marilyn L. , Castillo Adrienne L. , Prado Carla M.
Published: April 2018

Background and aim

Co‐morbidities and computerized tomography‐measured muscle abnormalities are both common in cancer patients and independently adversely influence clinical outcomes. Muscle abnormalities are also evident in other diseases, such as diabetes and obesity. This study examined for the first time the association between co‐morbidities and muscle abnormalities in patients diagnosed with colorectal cancer (CRC).

Methods

This cross‐sectional study included 3051 non‐metastatic patients with Stages I–III CRC. Muscle abnormalities, measured at diagnosis, were defined as low skeletal muscle mass index (SMI) or low skeletal muscle radiodensity (SMD) quantified using computerized tomography images using optimal stratification. Co‐morbidities included in the Charlson index were ascertained. χ2 tests were used to compare the prevalence of co‐morbidities by the presence or absence of each muscle abnormality. Logistic regressions were performed to evaluate which co‐morbidities predicted muscle abnormalities adjusting for age, sex, body mass index, weight change, cancer stage, cancer site, race/ethnicity, and smoking.

Results

Mean age was 63 years; 50% of patients were male. The prevalence of low SMI and low SMD were 43.1% and 30.2%, respectively. Co‐morbidities examined were more prevalent in patients with low SMD than in those with normal SMD, and most remained independent predictors of low SMD after adjustment for covariates. Co‐morbidities associated with higher odds of low SMD included myocardial infarction [odds ratio (OR) = 1.77, P = 0.023], congestive heart failure (OR = 3.27, P < 0.001), peripheral vascular disease (OR = 2.15, P = 0.002), diabetes with or without complications (OR = 1.61, P = 0.008; OR = 1.46, P = 0.003, respectively), and renal disease (OR = 2.21, P < 0.001). By contrast, only diabetes with complications was associated with lower odds of low SMI (OR = 0.64, P = 0.007).

Conclusions

Prevalence of muscle abnormalities was high in patients with non‐metastatic CRC. Pre‐existing co‐morbidities were associated with low SMD, suggestive of a potential shared mechanism between fat infiltration into muscle and each of these co‐morbidities.
Effect of heat treatment on the microstructure and properties of Ni based soft magnetic alloy
Authors: Li Chunhong , Ruan Hui , Chen Dengming , Li Kejian , Guo Donglin , Shao Bin
Published: April 2018

A Ni‐based alloy was heat treated by changing the temperature and ambient atmosphere of the heat treatment. Morphology, crystal structure, and physical performance of the Ni‐based alloy were characterized via SEM, XRD, TEM, and PPMS. Results show that due to the heat treatment process, the grain growth of the Ni‐based alloy and the removal of impurities and defects are promoted. Both the orientation and stress caused by rolling are reduced. The permeability and saturation magnetization of the alloy are improved. The hysteresis loss and coercivity are decreased. Higher heat treatment temperature leads to increased improvement of permeability and saturation magnetization. Heat treatment in hydrogen is more conducive to the removal of impurities. At the same temperature, the magnetic performance of the heat‐treated alloy in hydrogen is better than that of an alloy with heat treatment in vacuum. The Ni‐based alloy shows an excellent magnetic performance on 1,373 K heat treatment in hydrogen atmosphere. In this process, the µm, Bs, Pu, and Hc of the obtained alloy are 427 mHm−1, 509 mT, 0.866 Jm−3, and 0.514 Am−1, respectively. At the same time, the resistivity of alloy decreases and its thermal conductivity increases in response to heat treatment.
BTADCI Promoted One‐pot Synthesis of 14‐aryl‐14H‐dibenzo [a, j] Xanthenes
Authors: Pagadala Ramakanth , Kusampally Uppalaiah
Published: April 2018

A convenient eco‐friendly one‐pot synthesis of 14‐aryl‐14H‐dibenzo [a, j] xanthenes were developed by the condensation of aromatic aldehydes and β‐naphthol with BTADCI (Benzyltrimethylammonium dichloroiodate) as catalyst under solvent free conditions and microwave irradiation with much more rate accelerations and afford very good yields. Developed protocols involve mild reaction conditions, simple isolation of derivatives with inexpensive reagents.
Age‐related changes in cortical and subcortical structures of healthy adult brains: A surface‐based morphometry study
Authors: Zheng Fenglian , Liu Yulin , Yuan Zilong , Gao Xiaodong , He Yaoyao , Liu Xiaojing , Cui Dong , Qi Rui , Chen Tiao , Qiu Jianfeng
Published: April 2018

Background

Cerebral structures in both cortical and subcortical regions change with aging. More specific and comprehensive studies are needed to better elucidate these changes.

PURPOSE

To investigate the relationships between age and cerebral structures regarding cortical and subcortical changes.

Study Type

Cross‐cohort research.

Population

54 healthy adults (28 females) aged 21–71 years.

Field Strength/Sequence

T1‐weighted imaging was performed at 1.5T.

ASSESSMENT

The cortical thickness, local gyrification index (LGI), and the volumes of total gray matter (GM), white matter (WM), white matter hyperintensity (WMH), deep gray matter nuclei (putamen, pallidum, thalamus, caudate, amygdala, accumbens area, and hippocampus), ventricles, and hippocampal subfields were obtained using FreeSurfer software.

Statistical Tests

Regression analysis was performed to determine the relationships between age and cortical thickness, LGI, and volumes of subcortical structures. Uncorrected P values ≤ 0.001 and R2 > 0.16 were considered significant.

Results

The cortical thickness and LGI decreased with age throughout almost all brain regions (R2 > 0.16; P ≤ 0.001). Except for the volumes of the WM and 4th ventricle (R2 < 0.16; P > 0.001), the volumes of the GM, WMH, lateral ventricle, inferior lateral ventricle, and 3rd ventricle showed a nonlinear correlation with aging (R2 > 0.16; P ≤ 0.001). For deep gray matter nuclei, the thalamus volume was significantly decreased with aging (R2 = 0.256; P = 0.001). Additionally, the hippocampus volume was initially increased and then decreased at age of 50, mainly in the granule cell layer of the dentate gyrus (GC‐DG), cornus ammonis 2/3 (CA2/3), CA4, and fissure (R2 > 0.16; P ≤ 0.001). The volumes of the putamen, pallidum, accumbens area, amygdala and caudate showed no significance with aging (R2 < 0.16; P > 0.001).

Data Conclusion

The results comprehensively show the relationships between age and cerebral structures in multiple brain regions, and these findings may help identify normal aging and other age‐related neuroradiological disorders.

Level of Evidence: 2

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2019;49:152–163.
Assessment of microbial contaminations in commercial frozen duck meats and the application of electron beam irradiation to improve their hygienic quality
Authors: An Kyung‐A , Jo Yunhee , Akram Kashif , Suh Sang‐Cheol , Kwon Joong‐Ho
Published: April 2018

BACKGROUND

High microbial load is a serious concern in terms of the health‐related safety of products of animal origin. In this study, the microbial loads of commercial frozen duck‐meat products, including bone‐in whole raw, boneless sliced raw, and boneless whole smoked, were investigated for pathogenic contamination. The application of electron beam irradiation was also investigated.

RESULTS

The samples revealed a serious microbial threat (102–105 CFU g−1 for total aerobic bacteria and positive for foodborne pathogens), which required effective decontamination technology. Electron‐beam irradiation (0, 1, 3, and 7 kGy) could potentially improve the hygienic quality of duck‐meat samples. The D10 values for Listeria monocytogenes and Salmonella Typhi were 0.47 and 0.51 kGy, respectively. A direct epifluorescent filter technique and aerobic plate count (DEFT/APC) method was used for screening, while electron‐spin resonance (ESR) spectroscopy and gas chromatography with mass spectrometry were effective as confirmatory techniques to identify radiation‐induced markers in frozen duck meat.

CONCLUSION

Electron‐beam irradiation has the potential to ensure the microbial safety and hygienic quality of commercial duck meats. Identification of the samples for their irradiation history was also possible using radiation‐induced detection markers, including the DEFT/APC, hydroxyapatite ESR radicals, and hydrocarbons. © 2018 Society of Chemical Industry
Facile preparation of multifunctional carbon nanotube/magnetite/polyaniline nanocomposite offering a strong option for efficient solid‐phase microextraction coupled with GC–MS for the analysis of phenolic compounds
Authors: Tafazoli Zahra , Azar Parviz Aberoomand , Tehrani Mohammad Saber , Husain Syed Waqif
Published: April 2018

The aim of this study was to synthesize a highly efficient organic–inorganic nanocomposite. In this research, the carbon nanotube/magnetite/polyaniline nanocomposite was successfully prepared through a facile route. Monodisperse magnetite nanospheres were prepared through the coprecipitation route, and polyaniline nanolayer as a modified shell with a high surface area was synthesized by an in situ growth route and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy. The prepared nanocomposite was immobilized on a stainless‐steel wire for the fabrication of the solid‐phase microextraction fiber. The combination of headspace solid‐phase microextraction using carbon nanotube/magnetite/polyaniline nanocomposite fiber with gas chromatography and mass spectrometry can achieve a low limit of detection and can be applied to determine phenolic compounds in water samples. The effects of the extraction and desorption parameters including extraction temperature and time, ionic strength, stirring rate, pH, and desorption temperature and time have been studied. Under the optimum conditions, the dynamic linear range was 0.01–500 ng/mL and the limits of detection of phenol, 4‐chlorophenol, 2,6‐dichlorophenol, and 2,4,6‐trichlorophenol were the lowest (0.008 ng/mL) for three times. The coefficient of determination of all calibration curves was more than 0.990.
Measuring ephemeral gully erosion rates and topographical thresholds in an urban watershed using unmanned aerial systems and structure from motion photogrammetric techniques
Authors: Gudino‐Elizondo Napoleon , Biggs Trent W. , Castillo Carlos , Bingner Ronald L. , Langendoen Eddy J. , Taniguchi Kristine T. , Kretzschmar Thomas , Yuan Yongping , Liden Douglas
Published: April 2018

Both rural and urban development can lead to accelerated gully erosion. Quantify gully erosion is challenging in environments where gullies are rapidly repaired and in urban areas where microtopographic complexity complicates the delineation of contributing areas. This study used unmanned aerial systems and structure from motion photogrammetric techniques to quantify gully erosion in the Los Laureles Canyon Watershed, a rapidly urbanizing watershed in Tijuana, Mexico. Following a storm event, the gully network extent was mapped using an orthomosaic (0.038‐m pixel size); the local slope and watershed area contributing to each gully head were mapped with a digital surface model (0.3‐m pixel size). Gullies formed almost exclusively on unpaved roads, which had erodible soils and concentrated flow. Management practices (e.g., road maintenance that fill gullies after large storms) contributed to total sediment production at the watershed scale. Sediment production from gully erosion was higher, and threshold values of slope and drainage area for gully incision were lower than ephemeral gullies reported for agricultural settings. This indicates high vulnerability to gully erosion, which is consistent with high soil erodibility and low critical shear stress measured in the laboratory with a mini‐jet‐erosion test device. Future studies that evaluate effects of different soil types on gully erosion rates on unpaved roads, as well as model effects of management practices such as road paving and their impact on runoff, soil erosion, and sediment loads, are crucial for proper sediment management and planning in urban watersheds.
Multicolored, Low‐Voltage‐Driven, Flexible Organic Electrochromic Devices Based on Oligomers
Authors: Wan Zhijun , Zeng Jinming , Li Hui , Liu Ping , Deng Wenji
Published: April 2018

In this study, a series of organic conjugated oligomers containing 3,4‐ethylenedioxythiophene (EDOT) and aromatic groups are synthesized, which are as follows: 2,5‐di(methyl benzoate)‐3,4‐ethylenedioxy‐thiophene (1EDOT‐2B‐COOCH3), 5,5′‐di(methyl benzoate)‐2,2′‐bi(3,4‐ethylenedioxythiophene) (2EDOT‐2B‐COOCH3), 5,5″‐di(methyl benzoate)‐2,2′:5′,2″‐ter(3,4‐ethylenedioxythiophene) (3EDOT‐2B‐COOCH3), and 5,5″′‐di(methyl benzoate)‐2,2′:5′,2″: 5″,2″′‐quater(3,4‐ethylenedioxythiophene) (4EDOT‐2B‐COOCH3). Using these oligomers as active materials, flexible organic electrochromic devices are fabricated. The device structure is indium tin oxide–PET plastic slide (ITO‐PET)/active layer/conducting gel/ITO‐PET, and the electrochromic properties of oligomers are investigated. These oligomers exhibit reversible color changes upon electrochemical doping and dedoping. The highest optical contrast is exhibited by 4EDOT‐2B‐COOCH3, which is 75.2% at 700 nm.
Photoregulating of Stretchability and Toughness of a Self‐Healable Polymer Hydrogel
Authors: Xiong Chenxiao , Zhang Lidong , Xie Meiran , Sun Ruyi
Published: April 2018

Supramolecular hydrogels that are assembled through dynamic host–guest interactions have presented apparent potential in the construction of materials with promising performance. Herein, a photoregulated hydrogel cross‐linked by host–guest interactions with multifunctions of high stretchability, strong toughness, and rapid self‐healing property is reported. The hydrogel exhibits unique light‐responsive property due to the introduction of two photoisomerized groups. For example, the stress–strain curve of the original hydrogel indicates 1020% rupture strain with the maximum tensile strain value of 214 kPa. Upon 365 nm light irradiation for an hour, its tensile strain increases to 15 times with lower tensile stress indicating a better stretchability. Moreover, the hydrogel is photochromic and surface patternable, where it can reversibly switch color between luminous yellow and brown while exposed to 365 and 440 nm light irradiation. It holds great promise for applying in self‐recovering optically controlled and labeled elastic mechanical materials.
Electrospun Nanocomposite Nanofibres With Magnetic Nanoparticle Decorated Carbon Nanotubes
Authors: van Deventer Nedine , Mallon Peter E.
Published: April 2018

Oxidized multi‐wall carbon nanotubes (MWCNTs) are decorated with iron oxide (Fe3O4) nanoparticles using an ex situ and simpler single‐step in situ approach (synthesis of ex situ and in situ MWCNT‐Fe3O4). The polar carboxylic acid moieties present on the MWCNT backbone, as a result of oxidation, acted as anchoring sites through which the nanoparticles could be attached. The remaining carboxylic acid moieties present on the backbone facilitated dissolution in polar solvents (such as dimethylformamide (DMF)); which allowed for incorporation of the respective MWCNT‐Fe3O4 samples as filler nanomaterials into nanofibres using the electrospinning technique. Excellent dispersion and alignment of the respective MWCNT‐Fe3O4 samples along the poly(methyl methacrylate) (PMMA) electrospun nanofibre axis were obtained. Highest values for magnetization were exhibited by the electrospun composite nanofibres containing ex situ synthesized MWCNT‐Fe3O4; where these composites are proposed for use in SMART polymer applications such as tissue scaffolds or magnetic filters.
Impact of Exposure Conditions on the Morphology of Polyethylene by Compact NMR
Authors: Teymouri Yadollah , Adams Alina , Blümich Bernhard
Published: April 2018

Today many polyethylene (PE) products are employed in long‐term applications that require the use of elevated temperatures and/or contact with different solvents. Both the exposure to heat and solvents can result in morphological changes, compromising the mechanical stability of the material. Disentangling morphological changes induced by either type of exposure and understanding their combined effect is crucial for establishing reliable structure‐property relationships. This, in turn, requires sensitive analytical methods that can probe the complex morphology of PE both in the laboratory and on site. Among existing analytical methods, NMR with compact devices have recently become a key analytical tool for the detailed morphological characterization of a variety of solid polymers including PE. This current work reviews the potential of compact NMR for monitoring and quantifying morphological changes in PE exposed to the aforementioned external conditions. To prove the reliability of compact proton NMR relaxation measurements, the results are compared with data from conventional high‐field proton wide‐line NMR spectroscopy, DSC, and FTIR spectroscopy. It could be shown that simple, static proton relaxation measurements garner detailed information about the exposure‐induced morphological changes through the quantification of phase composition and chain dynamics. Moreover, the NMR method has a key advantage over other methods, because the chain mobility of the soft amorphous phase is a very sensitive microscopic parameter under exposure conditions. The various presented examples and the good agreement of the NMR results with those of other analytical methods show that low‐field NMR is a promising option for in‐situ aging studies.
Synthesis and Characterization of Novel Ion‐Conducting Membranes Based on Poly(ether sulfone) and Protic Ionic Liquid
Authors: Batalha João A. F. L. , Sampaio Rômulo B. , Filho José C. D. , da Rocha Rodrigues Elton J. , Neto Roberto P. C. , de Souza Gomes Ailton
Published: April 2018

Concerns about environmental preservation instigate new investigations on alternative energy sources, such as proton exchange membrane fuel cells (PEMFCs). In order to avoid efficiency loss in PEMFC systems, at temperatures above 100 °C and minimize catalyst poisoning, anhydrous conditions are proposed, with substitution of water molecules by protic ionic liquids (PILs) as conducting medium for ions. PILs also feature excellent thermal stability. In this work, poly(ether sulfone) (PES), diethylmethylamine triflate ([dema][TfOH]) and titania (TiO2) or zirconia (ZrO2) based membranes were obtained and characterized, so that the filler effect on ion conductivity and polymer/PIL compatibility could be evaluated. XRD and TGA results indicated higher PES chain organization induced by the oxide networks, with thermal stability over 200 °C. These networks also contribute to better PIL retention in the membranes, as shown by TD‐NMR, and help improve ion conductivity, reaching values 160% higher than those found in samples containing just PIL.
Proactive Rainbow Trout Suppression Reduces Threat of Hybridization in the Upper Snake River Basin
Authors: Kovach Ryan P. , Al-Chokhachy Robert , Stephens Tracy
Published: April 2018

Preserving remaining nonhybridized populations Cutthroat Trout Oncorhynchus clarkii is a conservation priority often requiring management action. Although proactive programs for Rainbow Trout O. mykiss and hybrid suppression offer a flexible tool, particularly in large interconnected river basins, this management approach is used less frequently than alternatives such as barriers and piscicides. We describe the results of a targeted Rainbow Trout hybrid suppression program spanning 15 years in the upper Snake River, Wyoming, a core stronghold for Yellowstone Cutthroat Trout O. clarkii bouvieri. Initially, Rainbow Trout hybrids were relatively common in the Gros Ventre River, a major tributary to the Snake River. Between 2002 and 2016, 926 individuals of Rainbow Trout ancestry were removed from the Gros Ventre River. Relative abundance of Rainbow Trout hybrids decreased over this time, while the Yellowstone Cutthroat Trout population increased. Temporal genetic data collected in 2007–2008 and again in 2014 demonstrate that the overall proportion Rainbow Trout admixture and the proportion of hybrids in a sample both significantly decreased in the Gros Ventre River and did not increase elsewhere in the Snake River basin. In conclusion, proactive Rainbow Trout suppression appears to have reduced the threat of Rainbow Trout hybridization in this river basin and helped protect an interconnected metapopulation that has a highly diverse life history and genetic variation important for long-term persistence.
Deadline‐aware TCP congestion control for HTTP adaptive streaming services
Authors: Claeys Maxim , Bouten Niels , De Vleeschauwer Danny , De Schepper Koen , Van Leekwijck Werner , Latré Steven , De Turck Filip
Published: April 2018

Over the last decades, video streaming services have gained a lot of popularity, representing over 70% of the total consumer Internet traffic worldwide. While originally dedicated streaming protocols have been used to deliver these services, for several years, the video streaming industry is steadily shifting to HTTP adaptive streaming (HAS)–based delivery over TCP. With each video segment, implicit delivery deadlines are associated in order to avoid playout interruptions. However, TCP is known to be far from minimizing the number of deadline‐missing streams. In this paper, 2 deadline‐aware congestion control mechanisms are proposed, based on a parametrization of the traditional TCP New Reno congestion control strategy. By introducing deadline awareness at the transport layer, the modulation of the congestion window size is dynamically adapted to steer the aggressiveness of the considered stream to optimize the delivery of video streaming services. The proposed approaches are thoroughly evaluated in an HAS video‐on‐demand scenario over tree‐based delivery networks. It was shown that in a realistic scenario, the proposed approaches can outperform traditional congestion control strategies by up to 12% in terms of estimated mean opinion score, mainly by reducing the average video freezing time by more than 85%.
Domain decomposition preconditioners for multiscale problems in linear elasticity
Authors: Buck Marco , Iliev Oleg , Andrä Heiko
Published: April 2018

We analyze two‐level overlapping Schwarz domain decomposition methods for vector‐valued piecewise linear finite element discretizations of the PDE system of linear elasticity. The focus of our study lies in the application to compressible, particle‐reinforced composites in 3D with large jumps in their material coefficients. We present coefficient‐explicit bounds for the condition number of the two‐level additive Schwarz preconditioned linear system. Thereby, we do not require that the coefficients are resolved by the coarse mesh. The bounds show a dependence of the condition number on the energy of the coarse basis functions, the coarse mesh, and the overlap parameters, as well as the coefficient variation. Similar estimates have been developed for scalar elliptic PDEs by Graham et al. The coarse spaces to which they apply here are assumed to contain the rigid body modes and can be considered as generalizations of the space of piecewise linear vector‐valued functions on a coarse triangulation. The developed estimates provide a concept for the construction of coarse spaces, which can lead to preconditioners that are robust with respect to high contrasts in Young's modulus and the Poisson ratio of the underlying composite. To confirm the sharpness of the theoretical findings, we present numerical results in 3D using vector‐valued linear, multiscale finite element and energy‐minimizing coarse spaces. The theory is not restricted to the isotropic (Lamé) case, extends to the full‐tensor case, and allows applications to multiphase materials with anisotropic constituents in two and three spatial dimensions. However, the bounds will depend on the ratio of largest to smallest eigenvalue of the elasticity tensor.