bluuebunny/crossref_metadata_2025 huggingface dataset:
Deriving formulas for an unsteady virtual velocity of bedload tracers
Authors: Klösch Mario , Habersack Helmut
Published: December 2017

In a flume experiment with steady flow conditions, H. A. Einstein recognised the transport of bedload particles as consisting of steps of rolling, sliding, or saltation with intermittent rest periods, and introduced the concept of an average, ‘virtual’ transport velocity. This virtual velocity then has also been derived from tracer studies in the field by dividing the travelled distance of a tracer by the duration of competent flow. As a consequence, the virtual velocity in the field is represented by one single value only, despite the unsteady flow variables. Tracer measurements in a river have not been yet used to express transport velocity as a direct function of these actual variables, and insights from tracer measurements into the processes of sediment transport remain limited. In particular, the unsteady conditions for bedload in the field have impeded the derivation of sediment transport characteristics as determined from laboratory experiments, as well as the transfer of laboratory insights to a field setting. We introduce a method of data regression for the derivation of an ‘unsteady’ virtual velocity from repeated surveys of tracer positions. The regression program called graVel (provided as supplementary material) relates the integral of an excess flow variable term to measured travel distances, yielding the most probable threshold value for entrainment and the coefficient of linear and non‐linear formulas. An extended regression allows additional fitting of the exponent in non‐linear formulas. Application to published tracer data from the Mameyes River, Puerto Rico, shows that the unsteady virtual velocity is more likely governed by non‐linear relations to excess Shields stress, similar to bedload transport, than by relations linking the particle velocity linearly to excess shear velocity. Partial agreements with non‐dimensional results derived from the larger, non‐wadeable Mur River encourage the establishment of a generalised formula for the unsteady virtual velocity. Copyright © 2017 John Wiley & Sons, Ltd.
Effects of rainfall, overland flow and their interactions on peatland interrill erosion processes
Authors: Li Changjia , Holden Joseph , Grayson Richard
Published: December 2017

Interrill erosion processes on gentle slopes are affected by mechanisms of raindrop impact, overland flow and their interaction. However, limited experimental work has been conducted to understand how important each of the mechanisms are and how they interact, in particular for peat soil. Laboratory simulation experiments were conducted on peat blocks under two slopes (2.5° and 7.5°) and three treatments: Rainfall, where rainfall with an intensity of 12 mm h−1 was simulated; Inflow, where upslope overland flow at a rate of 12 mm h−1 was applied; and Rainfall + Inflow which combined both Rainfall and Inflow. Overland flow, sediment loss and overland flow velocity data were collected and splash cups were used to measure the mass of sediment detached by raindrops. Raindrop impact was found to reduce overland flow by 10 to 13%, due to increased infiltration, and reduce erosion by 47% on average for both slope gradients. Raindrop impact also reduced flow velocity (80–92%) and increased roughness (72–78%). The interaction between rainfall and flow was found to significantly reduce sediment concentrations (73–85%). Slope gradient had only a minor effect on overland flow and sediment yield. Significantly higher flow velocities and sediment yields were observed under the Rainfall + Inflow treatment compared to the Rainfall treatment. On average, upslope inflow was found to increase erosion by 36%. These results indicate that overland flow and erosion processes on peat hillslopes are affected by upslope inflow. There was no significant relationship between interrill erosion and overland flow, whereas stream power had a strong relationship with erosion. These findings help improve our understanding of the importance of interrill erosion processes on peat. Copyright © 2017 John Wiley & Sons, Ltd.
Why Competitive Markets Need to Remain Competitive, 2018 and Beyond
Authors: DeCotis Paul A.
Published: December 2017

As written in a previous column, the US Department of Energy released the Staff Report on Electricity Markets and Reliability in September 2017.
Resilience Finally Debuts in Electricity Markets and Raises 2018 Questions
Authors: Russo Thomas
Published: December 2017

Back in May 2015, I presented a paper1 in Houston on the resilience of natural gas and oil pipelines and their relationship to the power sector. The audience was polite, but few people were interested in resilience. How things have changed!
A new Late Pennsylvanian floral assemblage from the Douro Basin, Portugal
Authors: Correia Pedro , Šimůnek Zbynĕk , Sá Artur A. , Flores Deolinda
Published: December 2017

The Douro Basin (lower Gzhelian/lower Stephanian C, Upper Pennsylvanian; NW Portugal) is one of the richest continental sedimentary basins in fossil floras of late Carboniferous age in Portugal. Recent field work carried out in the Douro Basin allowed to report a new fossil site, of potential Lagerstätte quality, found in the Montes da Costa (Ermesinde) region. This new fossil locality preserves exceptional palaeontological, stratigraphic, lithological, and tectonic structural features of great scientific interest. An exceptional record of sudden catastrophic flooding events represents one of the most remarkable geological records documented in this new locality. In the palaeontological context, the plant assemblage described comprises a well‐preserved and very diversified macroflora of early Gzhelian age, consisting of several fossil taxa belonging mainly to genera and species of Pteridopsida, Pteridospermopsida, and Sphenopsida. Its fossil records are essentially parautochthonous deposits, but several Calamites trunks preserved in autochthonous position were documented. Within the studied plant assemblage, a new species of arborescent marattialean fern, Acitheca murphyi sp. nov., is described, and several new floral occurrences are first reported in the Portuguese Carboniferous. Here, we analyse the palaeoecological, palaeoenvironmental, and palaeoclimatic conditions of the new palaeobotanical data. Additionally, there was undertaken an extensive comparative study of Gzhelian (Stephanian C–early Autunian) age macrofloras from different localities of Europe and North America. Together with these results, a significant macrofloral biostratigraphic gap for the Kasimovian stage in the Appalachian region (West Virginia, USA) is demonstrated to be correlated to the Late Pennsylvanian of Portugal, and its palaeogeographic significance is assessed.
Hallucination‐ and speech‐specific hypercoupling in frontotemporal auditory and language networks in schizophrenia using combined task‐based fMRI data: An fBIRN study
Authors: Lavigne Katie M. , Woodward Todd S.
Published: December 2017

Hypercoupling of activity in speech‐perception‐specific brain networks has been proposed to play a role in the generation of auditory‐verbal hallucinations (AVHs) in schizophrenia; however, it is unclear whether this hypercoupling extends to nonverbal auditory perception. We investigated this by comparing schizophrenia patients with and without AVHs, and healthy controls, on task‐based functional magnetic resonance imaging (fMRI) data combining verbal speech perception (SP), inner verbal thought generation (VTG), and nonverbal auditory oddball detection (AO). Data from two previously published fMRI studies were simultaneously analyzed using group constrained principal component analysis for fMRI (group fMRI‐CPCA), which allowed for comparison of task‐related functional brain networks across groups and tasks while holding the brain networks under study constant, leading to determination of the degree to which networks are common to verbal and nonverbal perception conditions, and which show coordinated hyperactivity in hallucinations. Three functional brain networks emerged: (a) auditory‐motor, (b) language processing, and (c) default‐mode (DMN) networks. Combining the AO and sentence tasks allowed the auditory‐motor and language networks to separately emerge, whereas they were aggregated when individual tasks were analyzed. AVH patients showed greater coordinated activity (deactivity for DMN regions) than non‐AVH patients during SP in all networks, but this did not extend to VTG or AO. This suggests that the hypercoupling in AVH patients in speech‐perception‐related brain networks is specific to perceived speech, and does not extend to perceived nonspeech or inner verbal thought generation.
Teachers become cocreators through participation in a teacher professional development (TPD) course in a resource constraint environment in South Africa
Authors: Botha Adele , Herselman Marlien
Published: December 2017

The purpose of this paper is to provide insight into how teachers became cocreators by merging their existing knowledge of their subject, context, and new knowledge of using mobile tablets towards enhancing their teaching practices. This was achieved in a specific area in the Eastern Cape Province of South Africa over a period of 3 years. The intentional situating of teachers as cocreators was implementation through a teacher professional development (TPD) course. The course consisted of 10 modules presented and completed over a 1‐year period. The TPD course was developed as an artefact using Design Science as a methodology with 3 iterations of implementation to refine it. The development of the course and its iterative implementation and refinement was grounded in the Living Lab open innovation approach with elements of gamification (coopetition), and various stakeholders were incorporated. Structuration theory was applied to indicate the “duality of structure” where structure and agency are related and dependent on each other and agents' actions produce, reproduce, and develop social structures. Technology endowments were integrated as part of the gamification and were dependent on predefined cocreation events. Each event was linked to a badge, and teachers had to provide practice‐based evidence of how new knowledge, proficiencies, and skills gained during the TPD sessions was adapted to their own subject and context knowledge and practically implemented in their classrooms. This presents an innovative way to introduce and use tablets in teaching and learning (structure) as teachers (agents) are acknowledged as domain and subject experts, and through exposure to technology and pedagogical strategies in using the technology (resources), they become cocreators of their own new enhanced classroom practice (social structures) and adopted the technology.
Examining capability enhancement through mobile phone use:The case of SouthernGhana
Authors: Yim Moonjung , Gomez Ricardo
Published: December 2017

With near half of African population being unique subscribers of mobile phones, we are beginning to understand how people in the continent—and more broadly in the Global South—are interacting with their mobile phone in everyday life, and whether it contributes to development and to capability enhancement, following Amartya Sen's notions. Analyzing interviews on mobile phone uses in Southern Ghana based on Sen's Capability Approach and Dorothea Kleine'sChoiceFramework, we claim that real‐life uses of mobile phones demonstrate capability enhancement, as it facilitates (1) communication with weak and strong social ties which generates positive outcomes such as exchange of emotional support, information or knowledge, and mobilization of financial resources; (2) information retrieval linked to knowledge expansion and occupational practices; and (3) flexibility in life at work and overcoming physical weakness. The study seeks to contribute towards more profound understanding of the role that mobile phone uses play in development context by looking at everyday uses. In turn, it seeks to address the question of “can mobile phone uses support development in a sustainable and inclusive way that would lead to a quality of life deemed as valuable and meaningful by people?”
An Ectopic Imaging Window for Intravital Imaging of Engineered Bone Tissue
Authors: Stiers Pieter‐Jan , van Gastel Nick , Moermans Karen , Stockmans Ingrid , Carmeliet Geert
Published: December 2017

Tissue engineering is a promising branch of regenerative medicine, but its clinical application remains limited because thorough knowledge of the in vivo repair processes in these engineered implants is limited. Common techniques to study the different phases of bone repair in mice are destructive and thus not optimal to gain insight into the dynamics of this process. Instead, multiphoton‐intravital microscopy (MP‐IVM) allows visualization of (sub)cellular processes at high resolution and frequency over extended periods of time when combined with an imaging window that permits optical access to implants in vivo. In this study, we have developed and validated an ectopic imaging window that can be placed over a tissue‐engineered construct implanted in mice. This approach did not interfere with the biological processes of bone regeneration taking place in these implants, as evidenced by histological and micro–computed tomography (μCT)‐based comparison to control ectopic implants. The ectopic imaging window permitted tracking of individual cells over several days in vivo. Furthermore, the use of fluorescent reporters allowed visualization of the onset of angiogenesis and osteogenesis in these constructs. Taken together, this novel imaging window will facilitate further analysis of the spatiotemporal regulation of cellular processes in bone tissue–engineered implants and provides a powerful tool to enhance the therapeutic potential of bone tissue engineering. © 2017 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Synthesis of Tetraketones Using ZnS Nanoparticles as an Efficient Catalyst
Authors: Safaei‐Ghomi Javad , Asadian Saeedeh , Nazemzadeh Seyed Hadi , Shahbazi‐Alavi Hossein
Published: December 2017

An efficient pseudo‐three‐component synthesis of tetraketones is described by one‐pot condensation of 5,5‐dimethylcyclohexane‐1,3‐dione and aldehydes using ZnS nanoparticles at room temperature. This method provides several advantages such as mild reaction conditions, applicability to a wide range of substrates, reusability of the catalyst, and low catalyst loading.
Extracellular vesicles derived from human embryonic stem cell‐MSCs ameliorate cirrhosis in thioacetamide‐induced chronic liver injury
Authors: Mardpour Soura , Hassani Seyedeh‐Nafiseh , Mardpour Saeid , Sayahpour Forough , Vosough Massoud , Ai Jafar , Aghdami Nasser , Hamidieh Amir Ali , Baharvand Hossein
Published: December 2017

Various somatic tissue‐derived mesenchymal stromal cells (MSCs) have been considered as an attractive therapeutic tool for treatment of liver diseases in which the secretion of soluble factors or extracellular vesicles (EVs) is the most probable mechanism. The experimental application of human embryonic stem cell‐derived MSC (ES‐MSC) increased rapidly and showed promising results, in vitro and in vivo. However, possible therapeutic effects of human ES‐MSC and their EVs on Thioacetamide (TAA)‐induced chronic liver injury have not been evaluated yet. Our data indicated that human ES‐MSC can significantly suppress the proliferation of peripheral blood mononuclear cells compared to bone marrow (BM)‐MSC and adipose (AD)‐MSC. Moreover, ES‐MSC increased the secretion of anti‐inflammatory cytokines (i.e., TGF‐β and IL‐10) and decreased IFN‐γ, compared to other MSCs. ES‐MSC EVs demonstrated immunomodulatory activities comparable to parental cells and ameliorated cirrhosis in TAA‐induced chronic rat liver injury, that is, reduction in fibrosis and collagen density, necrosis, caspase density, portal vein diameter, and transaminitis. The gene expression analyses also showed upregulation in collagenases (MMP9 and MMP13), anti‐apoptotic gene (BCL‐2) and anti‐inflammatory cytokines (TGF‐β1 and IL‐10) and down‐regulation of major contributors to fibrosis (Col1α, αSMA, and TIMP1), pro‐apoptotic gene (BAX) and pro‐inflammatory cytokines (TNFα and IL‐2) following treatment with ES‐MSC and ES‐MSC‐EV. These results demonstrated that human ES‐MSC and ES‐MSC EV as an off‐the‐shelf product, that needs further assessment to be suggested as an allogeneic product for therapeutic applications for liver fibrosis.
Association of interferon gamma gene polymorphism and susceptibility to hepatitis C virus infection in Egyptian patients: A multicenter, family‐based study
Authors: El‐Bendary Mahmoud , Neamatallah Mustafa , Elalfy Hatem , Besheer Tarek , El‐Setouhy Maged , Kasim Nihal , Abou El‐Khier Noha T , Kamel Emily , Eladl Abdel‐Hamid , El‐Waseef Ahmad , Abdel‐Aziz Abdel‐Aziz F , Esmat Gamal
Published: December 2017

Background and Aim

Polymorphisms in some genes may influence the persistence of hepatitis C virus (HCV) infection, clinical outcome, HCV replication, and liver damage. This study was conducted to investigate the role of the interferon gamma (IFN‐γ) gene at (+874 T/A, −764 G/C, −179 C/A) single‐nucleotide polymorphisms (SNPs) and its receptor (IFN‐γR2) at (rs 2786067 A/C) SNP in the susceptibility of Egyptian families to HCV infection with high‐resolution techniques.

Methods

In total, 517 Egyptian families, with 2246 subjects, were recruited to this study from the Upper and Lower Egypt governorates and were classified into three groups: 1034 patients with chronic hepatitis C virus, 108 subjects with spontaneous virus clearance (SVC), and 1104 subjects as a healthy control group. All subjects were genotyped for (+874 T/A, rs2430561, −764 G/C, rs2069707, −179 C/A, rs2069709, and rs 27860067, A/C) SNPs of the IFN‐γ gene using the allelic discrimination real‐time polymerase chain reaction technique and were confirmed using sequence‐based typing.

Results

The carriage of T allele of (+874) IFN‐γ is a risky allele and was significantly higher in chronic hepatitis C more than other two groups (odds ratio [OR]: 2.6646, P < 0.0002). On the other hand, the C allele of (−764, rs2069707) is a protective allele and was higher in SVC than the other two groups (OR: 0.2709, P < 0.0001). However, both (−179 C/A, rs 2069709) and (rs 27860067, A/C) SNPs are not polymorphic enough to be studied in the Egyptian population.

Conclusions

HCV infection is associated with the T allele of (+874 rs2430561), while SVC of HCV is associated with the C allele of (−764, rs2069707) of the IFN‐γ gene.
CD300 family receptors regulate eosinophil survival, chemotaxis, and effector functions
Authors: Rozenberg Perri , Reichman Hadar , Moshkovits Itay , Munitz Ariel
Published: December 2017

The CD300 family of receptors is an evolutionary conserved receptor family that belongs to the Ig superfamily and is expressed predominantly by the myeloid lineage. Over the past couple of years, accumulating data have shown that eosinophils express various Ig superfamily receptors that regulate key checkpoints in their biology including their maturation, transition from the bone marrow to the peripheral blood, migration, adhesion, survival, and effector functions in response to numerous activating signals such as IL-4, IL-33, and bacteria. In this review, we will present the emerging roles of CD300 family receptors and specifically CD300a and CD300f in the regulation of these eosinophil activities. The structure and expression pattern of these molecules will be discussed and their involvement in suppressing or co-activating eosinophil functions in health and disease will be illustrated.

CD300 receptors can regulate key eosinophil functions in response to diverse stimuli. Therefore, CD300 family receptors may provide pharmacological targets for eosinophil-associated diseases.
Porcine NK cells display features associated with antigen-presenting cells
Authors: De Pelsmaeker Steffi , Devriendt Bert , Leclercq Georges , Favoreel Herman W
Published: December 2017

NK cells are members of the innate immunity and play a central role in the defense against viral infections and cancer development, but also contribute to triggering and shaping adaptive immune responses. Human NK cells may express MHC II and costimulatory molecules, including CD86, CD80, and OX40 ligand, which allows them to stimulate the CD4+ T-cell response. In contrast, murine NK cells do not express MHC II or costimulatory molecules. Upon activation, mouse NK cells can acquire these molecules from dendritic cells (DCs) via intercellular membrane transfer, which leads to suppression of DC-induced CD4+ T-cell responses rather than stimulation of T-cell responses. Previous studies showed that porcine NK cells can express MHC II molecules, but it was unknown if porcine NK cells also express costimulatory molecules and whether NK cells may affect T-cell proliferation. We found that primary porcine NK cells express functional MHC II molecules and costimulatory CD80/86, particularly upon activation with IL-2/IL-12/IL-18, and that they are able to stimulate T-cell proliferation. In addition, we show that porcine NK cells are able to internalize antigens derived from killed target cells in an actin polymerization-dependent process. All together, these results indicate that porcine NK cells possess properties associated with APCs, which allows them to stimulate T-cell proliferation.
Bone marrow lesions in osteoarthritis: What lies beneath
Authors: Alliston Tamara , Hernandez Christopher J. , Findlay David M. , Felson David T. , Kennedy Oran D.
Published: December 2017

Osteoarthritis (OA) is the most common joint disease in the United States, affecting more than 30 million people, and is characterized by cartilage degeneration in articulating joints. OA can be viewed as a group of overlapping disorders, which result in functional joint failure. However, the precise cellular and molecular events within which lead to these clinically observable changes are neither well understood nor easily measurable. It is now clear that multiple factors, in multiple joint tissues, contribute to degeneration. Changes in subchondral bone are recognized as a hallmark of OA, but are normally associated with late‐stage disease when degeneration is well established. However, early changes such as Bone Marrow Lesions (BMLs) in OA are a relatively recent discovery. BMLs are patterns from magnetic resonance images (MRI) that have been linked with pain and cartilage degeneration. Their potential utility in predicting progression, or as a target for therapy, is not yet fully understood. Here, we will review the current state‐of‐the‐art in this field under three broad headings: (i) BMLs in symptomatic OA: malalignment, joint pain, and disease progression; (ii) biological considerations for bone‐cartilage crosstalk in joint disease; and (iii) mechanical factors that may underlie BMLs and drive their communication with other joint tissues. Thus, this review will provide insights on this topic from a clinical, biological, and mechanical perspective. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1818–1825, 2018.
Free sets for set‐mappings relative to a family of sets
Authors: Avilés Antonio , Piña Claribet
Published: December 2017

Given a family of subsets of , we try to compute the least natural number n such that for every function there exists a bijection such that for all .
Ag‐ZnO Nanocomposite Thin Film by RF‐Sputtering: An Electrical and Structural Study
Authors: Singh S. K. , Singhal R. , Siva Kumar V. V.
Published: December 2017

In the present study, pure ZnO and Ag‐ZnO nanocomposite (NCs) thin films with three different compositions were grown by RF magnetron co‐sputtering technique at substrate temperature 300 °C. The composite nature of the thin films was confirmed by Rutherford backscattering spectroscopy (RBS) and showed the existence of Ag, Zn, and O. The Ag fraction was found to be 8 at.%, 15  at.%, and 40 at.% in ZnO matrix. X‐ray diffraction analysis of the pure and composite thin films confirms the formation and structure of the film and reveal the hexagonal wurtzite structure of the pure ZnO thin film. Structural modifications in pure and composite thin films were observed by scanning electron microscopy (SEM). Raman measurements of the pure and Ag‐ZnO nanocomposite thin film were performed for the estimation of lattice defect and disordering which were induced by Ag incorporation. Electrical measurements revealed that the conductivity of nanocomposite thin film enhance drastically as compared to pure ZnO film and it increases with increasing Ag concentration. Furthermore, nanocomposite thin films showed a p‐type conductivity due to the incorporation of Ag metal, confirmed by Hall measurements.
Study of Lead Nitrate Doped PVA/PVP Blend Films using EDXRF and Complementary Techniques
Authors: Hammannavar Preeti B. , Lobo Blaise
Published: December 2017

Polyvinyl alcohol (PVA) − polyvinyl pyrrolidone (PVP) blend solutions were doped with different amounts of lead nitrate (Pb(NO3)2), in the doping range varying from 2.7 wt% up to 50.5 wt%. In this paper, the study of these films using Energy Dispersive X‐ray Fluorescence (EDXRF) technique in 2 π geometrical configuration is explained. In order to study K shell (Kαβ) X‐rays from the prepared films, cobalt‐57 radio‐isotope and thallium doped sodium iodide [NaI(Tl)] scintillation gamma/ x‐ray detector system with 1k MCA are used. The experiment was complemented by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X‐ray Spectroscopy (EDS). The SEM images revealed that the filler (Pb(NO3)2) causes significant micro‐structural changes in doped PVA/PVP blend films, revealing phase separation of the material into a polymer rich region and a dopant rich region at doping levels beyond 12.1 wt%. In addition to SEM, the EDXRF study is complemented by X‐Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) scans on the Pb (NO3)2 doped PVA/PVP blend films.
Photoluminescence Quenching in Metal Ion (Cu2+, Co2+) Interacted Graphene Quantum Dots
Authors: Mishra Praveen , Bhat B. Ramchandra
Published: December 2017

Graphene quantum dots (GQD) are nanosized fragments of graphene with finite band gap. Thus, GQDs show excellent photoluminescence (PL) and also possess good electrochemical properties. In the present study, we synthesized GQDs via hydrothermal (HT) method using Graphene oxide as prepared from improved Hummer's method as a precursor with several modifications. The effect of the variation in the photoluminescence and electrochemical properties of the as‐prepared GQDs were studied. Average particle size of the as‐synthesized GQDs was roughly 30 nm and produced blue PL on excitation with a wavelength of 365 nm. On reacting the GQDs with Cupric Nitrate and Cobalt Nitrate in separate batches, a significant decrease in the intensity of PL was observed. This quenching of PL of GQDs has been utilized in the qualitative estimation of Metal ion (Cu2+ and Co2+) species in aqueous media.
Effect of Bovine Serum Albumin on Red Blood Cell Optical Anisotropy Probed Through the Optomechanical Response in an Optical Trap
Authors: Praveen Parthasarathi , Rekha Selvan , Chetana Devarkonda , Iyengar Shruthi S. , Bhattacharya Sarbari , Ananthamurthy Sharath
Published: December 2017

The dynamics of trapped entities in an Optical Trap (OT) can yield information with regards to their viscoelastic response as well as optical anisotropy, if any. Detailed analysis of such dynamics correlated with parameters which affect the response can yield additional clues to the exact effect of these on the trapped entities. In this work, we illustrate this point by showing how the altered behavior of Red Blood Cells (RBC) treated with Bovine Serum Albumin (BSA) yields information about the nature of action of BSA, on which there is no current consensus in literature. We conclude from our studies that BSA treatment leads to a change in the birefringence of the RBCs, a conclusion arrived at from the altered optomechanical response of such cells in a linearly polarized Gaussian beam OT. Furthermore, we argue that the observed changes in cellular optical anisotropy may be thought of as due to changes in the curvature of the RBC membrane. We also note that BSA action could help mimic pathological conditions that result in an altered cell shape.
Copolymer Nanocomposite Thin‐Films Under Shear
Authors: Shagolsem Lenin S. , Kreer Torsten , Sommer Jens‐Uwe
Published: December 2017

By means of molecular dynamics simulations, we study the behaviour of lamellae forming diblock copolymer and nanoparticle mixtures in thin‐film geometry under stationary shear. In particular, we investigate the system under transverse mode of shear considering both nonselective and selective types of nanoparticles. We find that the presence of nanoparticles affects the critical shear rate at which the lamellar morphology is not stable during transverse shear and orientation transition sets in. We also study the spatial distribution of nanoparticles in the presence of flow field and its effect on the macroscopic response of the system.
Temperature Dependent Dielectric Behaviour of Nanocrystalline Co0.5Mg0.5Cr0.4Fe1.6O4 Ferrite
Authors: Jadoun Priya , Jyoti X. , Dolia S. N. , Bhatnagar Deepak , Saxena V. K.
Published: December 2017

Chromium substituted Co‐Mg ferrite with composition Co0.5Mg0.5Cr0.4Fe1.6O4 has been synthesized by solgel auto combustion method. X‐ray diffraction technique confirmed the formation of cubic spinel structure with no additional phase. In order to distinguish the effect of crystallite size‐ induced broadening and strain‐ induced broadening of XRD peaks, Williamson and Hall analysis has been performed. Dielectric constant, dielectric loss tangent and ac conductivity have been measured in the frequency range 50 kHz–120 MHz at room temperature. The decrease in dielectric constant with increasing frequency is attributed to Maxwell Wagner model. The variation of dielectric constant and loss tangent with temperature at different frequencies have also been studied.
2D Structured Nano‐Sheets of Octadecylamine Grafted Graphitic‐Carbon Nitride (g‐C3N4) as Lubricant Additives
Authors: Kumar Ajay , Thakre Gananath D. , Arya Pankaj K. , Jain Amar K.
Published: December 2017

The present paper introduces new type of 2D structured nano‐sheets as additives for lubricating oils. The 2D structured nano‐sheets of graphitic‐C3N4 (g‐C3N4) have been grafted with Octadecylamine to be used as additives. The nano‐fluids have been synthesized by blending amine grafted g‐C3N4 in lubricating oil in different weight percentage. A stable dispersion of g‐C3N4 in the base fluids has been achieved. The dispersion stability of nano‐fluids has been studied using UV‐visible spectrometer. The grafted g‐C3N4 nano‐sheets were characterized by analytical techniques like FT‐IR, TGA, TEM and EDX. The tribological properties of grafted g‐C3N4 nano‐fluids have been evaluated using 4 ball tribo‐tester using standard ASTM D: 4172B procedure. The comparative assessment of tribo‐performance reveals that amine grafted g‐C3N4 nano‐fluid significantly improve the anti‐friction and anti‐wear property. For a given concentration the g‐C3N4 nano‐fluids reduces friction and wear by 32 % and 17 % respectively as compared base fluid.
Structural Transformation and Hysteresis Behaviour of Ni46Cu4Mn45Sn5 Alloy Synthesized by Ball Milling Method
Authors: Saini Dinesh , Singh Satyavir , Banerjee M. K. , Sachdev K.
Published: December 2017

The present work reports synthesis and structural and magnetic studies of Ni46Cu4Mn45Sn5 shape memory alloy. The synthesis was done using solid state non‐equilibrium mechanical alloying (MA) technique. MA was performed in a Pulverisette‐6 ball milling machine using Tungsten Carbide (WC) bowl and balls. Ball to powder weight ratio of 10:1 and rotation speed of 300RPM were taken as milling parameters. After 20hr milling, the obtained powder was consolidated and quenched from high temperature to induce martensitic phase transformation. X‐ray diffraction (XRD) study indicates a phase mixture of austenite and martensite phase. Variation in lattice strain and crystallite size with milling time is calculated. Microstructural study reveals dual phase mixture after quenching. Phase transformation study carried out by Differential Scanning Calorimetric (DSC) indicates martensitic phase transformation of reversible nature. Vibrating sample magnetometer (VSM) has been utilized for magnetic characterization.
Effects of Annealing Temperature on Structural, Optical and Electrical Properties of Ge Nanocrystals Embedded in GeOx Matrix
Authors: Rathore Mahendra Singh , Vinod Arun , Rao N. Srinivasa
Published: December 2017

In this paper, the effects of annealing temperature on the growth of Ge nanocrystals embedded in GeOx matrix have been investigated. GeOx thin films deposited on Si and quartz substrates using electron beam evaporation were annealed under nitrogen ambience at 650, 750 and 850 °C. The pristine and annealed samples have been characterized using X‐ray diffraction, Raman spectroscopy, Atomic force microscopy, UV‐Visible spectroscopy and Semiconductor Device Analyzer (SDA). It is evident from XRD that the as‐deposited films are amorphous in nature, whereas the annealed films upto 750°C reveal the coexistence of crystalline Ge and GeO2. However, a further increase in temperature reflects only GeO2 phase and disappearance of Ge peak. The sharp and intense peak at 299 cm−1 for the films annealed up to 750 °C in the Raman spectra indicates the formation of Ge nanocrystals and the peak around 436 cm−1 is attributed to crystalline GeO2. The optical band gap of pristine and annealed films was calculated using UV–Vis spectroscopy. The I–V measurements of annealed films show the ohmic behavior. The results reveal that the annealing temperature significantly affects the crystallinity, size of nanocrystals and optical band gap of films. The impact of annealing temperature on the structural, optical and electrical properties of nc‐Ge embedded in GeOx matrix has been reported in detail.
Rheology and Microscopic Heterogeneity of Poly(ethylene oxide) Solid Polymer Electrolytes
Authors: Harun Fatin , Chan Chin Han , Guo Qipeng
Published: December 2017

Lack of precise thermal control in poly(ethylene oxide) (PEO)‐based solid polymer electrolytes (SPEs) with molar masses well above M > 104 g mol−1 during preparatory stage often demonstrates molar mass dependence on thermal properties and ionic conductivities. In the earlier study, PEO‐based SPEs were heated under inert atmosphere above the melting temperature of PEO and then cooled down for subsequent isothermal crystallization. The system demonstrates insignificant variation with respect to molar mass of PEO at constant salt concentration for thermal properties, ionic conductivity and intermolecular interaction. Here, we report the subsequent results of rheology and microscopic heterogeneity as a function of PEO molar mass (Mɳ = 3 × 105 and 4 × 106 g mol−1) and lithium salt concentration (0–13 wt.%). Above the solubility limit of PEO, the glass transition studied using differential scanning calorimetry shows the presence of microscopic heterogeneity of the systems as indicated by the change in enthalpy of endothermic overshoot near the endset of glass transition. Rheological parameters were measured over a wide range of frequency (0.01 to 100 Hz) at different temperatures (30, 60 and 80 °C) using parallel plate geometry. Melt rheology system reveals that neat PEO at 80 °C exhibits restriction in the long‐range motion of the chains. When incorporated with salt, it exhibits further deviation from the terminal viscoelastic relaxation behaviour. This study agrees with our previous findings that influence of molar mass of PEO in this range is insignificant on the melt rheology and microscopic heterogeneity at constant salt concentration.
X‐ray Absorption Spectroscopic Investigation of Ferromagnetic Ni‐doped ZnO
Authors: Jakhar Narendra , Samariya A. , Sharma S. C. , Dhawan M. , Palsania H. S. , Dolia S. N. , Singhal R. K.
Published: December 2017

The as‐synthesized 5% Ni‐doped single phase ZnO powder sample (Zn0.95Ni0.05O), prepared by solid state reaction method, shows a paramagnetic ground state at room temperature. However, when annealed under hydrogen atmosphere it shows a remarkable ferromagnetic state at 300 K. The hydrogen induced ferromagnetism is found to be reversible with regard to its re‐heating in air. To investigate the electronic properties of this Ni‐doped ZnO sample, we have carried out the element‐sensitive X‐ray‐absorption spectroscopic measurements, using synchrotron radiation, in the vicinity of the Ni 2p edge, the O K edge, and at the Zn 2p edge. The spectroscopic measurements show substantial changes in the near edge spectra of H‐annealed samples with respect to the as‐synthesized sample. The observed spectral changes may derive from both the Ni 3d‐O 2p hybridization and also from lattice defects such as oxygen vacancies. The spectral changes have been correlated with the room temperature ferromagnetism observed in this system which is very promising candidate for the future spintronic applications.
A novel splice variant in EMC1 is associated with cerebellar atrophy, visual impairment, psychomotor retardation with epilepsy
Authors: Geetha Thenral S. , Lingappa Lokesh , Jain Abhishek Ravindra , Govindan Hridya , Mandloi Nitin , Murugan Sakthivel , Gupta Ravi , Vedam Ramprasad
Published: December 2017

Background

Several genes have been implicated in a highly variable presentation of developmental delay with psychomotor retardation. Mutations in EMC1 gene have recently been reported. Herein, we describe a proband born of a consanguineous marriage, who presented with early infantile onset epilepsy, scaphocephaly, developmental delay, central hypotonia, muscle wasting, and severe cerebellar and brainstem atrophy.

Methods

Genetic testing in the proband was performed using custom clinical exome and targeted next‐generation sequencing. This was followed by segregation analysis of the variant in the parents by Sanger sequencing and evaluation of the splice variant by RNA sequencing.

Results

Clinical exome sequencing identified a novel homozygous intronic splice variant in the EMC1 gene (chr1:19564510C>T, c.1212 + 1G>A, NM_015047.2). Neither population databases (ExAC and 1000 genomes) nor our internal database (n = 1,500) had reported this rare variant, predicted to affect the splicing. RNA sequencing data from the proband confirmed aberrant splicing with intron 11 retention, thereby introducing a stop codon in the resultant mRNA. This nonsense mutation is predicted to result in the premature termination of protein synthesis leading to loss of function of the EMC1 protein.

Conclusion

We report, for the first time the role of aberrant EMC1RNA splicing as a potential cause of disease pathogenesis. The severe epilepsy observed in our study expands the disease‐associated phenotype and also emphasizes the need for comprehensive screening of intronic splice mutations.
Vitamin A Deficiency Induces Autistic‐Like Behaviors in Rats by Regulating the RARβ‐CD38‐Oxytocin Axis in the Hypothalamus
Authors: Lai Xi , Wu Xiaofeng , Hou Nali , Liu Shu , Li Qing , Yang Ting , Miao Jingkun , Dong Zhifang , Chen Jie , Li Tingyu
Published: December 2017

Scope

Vitamin A (VA) is an essential nutrient for the development of the brain. We previously found that children with autism spectrum disorder (ASD) have a significant rate of VA deficiency (VAD). In the current study, we aim to determine whether VAD is a risk factor for the generation of autistic‐like behaviors via the transcription factor retinoic acid receptor beta (RARβ)‐regulated cluster of differentiation 38 (CD38)‐oxytocin (OXT) axis.

Methods and results

Gestational VAD or VA supplementation (VAS) rat models are established, and the autistic‐like behaviors in the offspring rats are investigated. The different expression levels of RARβ and CD38 in hypothalamic tissue and serum retinol and OXT concentration are tested. Primary cultured rat hypothalamic neurons are treated with all‐trans retinoic acid (atRA), and recombinant adenoviruses carrying the rat RARβ (AdRARβ) or RNA interference virus RARβ‐siRNA (siRARβ) are used to infect neurons to change RARβ signal. Western blotting, chromatin immunoprecipitation (ChIP), and intracellular Ca2+ detections are used to investigate the primary regulatory mechanism of RARβ in the CD38‐OXT signaling pathway. We found that gestational VAD increases autistic‐like behaviors and decreases the expression levels of hypothalamic RARβ and CD38 and serum OXT levels in the offspring. VAS ameliorates these autistic‐like behaviors and increases the expression levels of RARβ, CD38, and OXT in the gestational VAD pups. In vitro, atRA increases the Ca2+ excitability of neurons, which might further promote the release of OXT. Different CD38 levels are induced in the neurons by infection with different RARβ adenoviruses. Furthermore, atRA enhances the binding of RARβ to the proximal promoter of CD38, indicating a potential upregulation of CD38 transcriptional activity by RARβ.

Conclusions

Gestational VAD might be a risk factor for autistic‐like behaviors due to the RARβ signal suppression of CD38 expression in the hypothalamus of the offspring, which improves with VAS during the early‐life period. The nutritional status during pregnancy and the early‐life period is important in rats.
Quantitative assessment of cerebral venous blood T2 in mouse at 11.7T: Implementation, optimization, and age effect
Authors: Wei Zhiliang , Xu Jiadi , Liu Peiying , Chen Lin , Li Wenbo , van Zijl Peter , Lu Hanzhang
Published: December 2017

Purpose

To develop a non–contrast‐agent MRI technique to quantify cerebral venous T2 in mice.

Methods

We implemented and optimized a T2‐relaxation‐under‐spin‐tagging (TRUST) sequence on an 11.7 Tesla animal imaging system. A flow‐sensitive‐alternating‐inversion‐recovery (FAIR) module was used to generate control and label images, pair‐wise subtraction of which yielded blood signals. Then, a T2‐preparation module was applied to produce T2‐weighted images, from which blood T2 was quantified. We conducted a series of technical studies to optimize the imaging slice position, inversion slab thickness, post‐labeling delay (PLD), and repetition time. We also performed three physiological studies to examine the venous T2 dependence on hyperoxia (N = 4), anesthesia (N = 3), and brain aging (N = 5).

Results

Our technical studies suggested that, for efficient data acquisition with minimal bias in estimated T2, a preferred TRUST protocol was to place the imaging slice at the confluence of sagittal sinuses with an inversion‐slab thickness of 2.5‐mm, a PLD of 1000 ms and a repetition time of 3.5 s. Venous T2 values under normoxia and hyperoxia (inhaling pure oxygen) were 26.9 ± 1.7 and 32.3 ± 2.2 ms, respectively. Moreover, standard isoflurane anesthesia resulted in a higher venous T2 compared with dexmedetomidine anesthesia (N = 3; P = 0.01) which is more commonly used in animal functional MRI studies to preserve brain function. Venous T2 exhibited a decrease with age (N = 5; P < 0.001).

Conclusion

We have developed and optimized a noninvasive method to quantify cerebral venous blood T2 in mouse at 11.7 T. This method may prove useful in studies of brain physiology and pathophysiology in animal models. Magn Reson Med 80:521–528, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Sedentary Time and MRI‐Derived Measures of Adiposity in Active Versus Inactive Individuals
Authors: Henson Joseph , Edwardson Charlotte L. , Morgan Bruno , Horsfield Mark A. , Khunti Kamlesh , Davies Melanie J. , Yates Thomas
Published: December 2017

Objective

The aim of this study was to examine cross‐sectional associations between objectively measured sedentary time and magnetic resonance imaging (MRI)‐assessed adiposity in a population at high risk for type 2 diabetes (T2DM) and to determine whether associations are modified by the recommended levels of moderate‐to‐vigorous physical activity (MVPA).

Methods

Sedentary time and MVPA were measured objectively by using accelerometers. Linear regression models examined the association of sedentary time with liver, visceral, subcutaneous, and total abdominal fat (quantified by using MRI). Interaction terms determined whether results were consistent across activity categories (active [> 150 min/wk of MVPA] vs. inactive [< 150 min/wk of MVPA]).

Results

One hundred and twenty‐four participants (age = 64.0 ± 7.1 years; male = 65.3%; BMI = 31.8 ± 5.6 kg/m2) were included. Following adjustment, each 60 minutes of sedentary time was associated with 1.74 L higher total abdominal fat, 0.62 L higher visceral fat, 1.14 L higher subcutaneous fat, and 1.86% higher liver fat. When results were stratified by MVPA (active vs. inactive), sedentary time was associated with greater liver, visceral, and total abdominal fat in the inactive group only.

Conclusions

These findings suggest that sedentary time is associated with higher levels of inter‐ and intraorgan fat, but associations with liver, visceral, and total abdominal fat were stronger in those who do not reach the current exercise recommendations for health.
Extending the Scope of 19F Hyperpolarization through Signal Amplification by Reversible Exchange in MRI and NMR Spectroscopy
Authors: Olaru Alexandra M. , Robertson Thomas B. R. , Lewis Jennifer S. , Antony Alex , Iali Wissam , Mewis Ryan E. , Duckett Simon B.
Published: December 2017

Fluorinated ligands have a variety of uses in chemistry and industry, but it is their medical applications as 18F‐labelled positron emission tomography (PET) tracers where they are most visible. In this work, we illustrate the potential of using 19F‐containing ligands as future magnetic resonance imaging (MRI) contrast agents and as probes in magnetic resonance spectroscopy studies by significantly increasing their magnetic resonance detectability through the signal amplification by reversible exchange (SABRE) hyperpolarization method. We achieve 19F SABRE polarization in a wide range of molecules, including those essential to medication, and analyze how their steric bulk, the substrate loading, polarization transfer field, pH, and rate of ligand exchange impact the efficiency of SABRE. We conclude by presenting 19F MRI results in phantoms, which demonstrate that many of these agents show great promise as future 19F MRI contrast agents for diagnostic investigations.
Excellent toughness, crystal morphology and crystallization mechanism of transcrystallization of polypropylene induced by layered interface
Authors: Lu Zhonghao , Zhao Bo , Yang Mingtao
Published: December 2017

The performances of isotactic polypropylene (iPP) have always been related to its crystal morphology and structure. In this work, β‐transcrystallization (β‐TC) was obtained by constructing iPP and β‐nucleated iPP (β‐iPP) multilayered structures. By changing the number of layers, the β‐TC content in layered samples was controlled. During the isothermal crystallization at 130°C, the β‐nucleating agents induced β‐spherulites in β‐iPP layers, then the β‐nucleus at the interface induced the formation of β‐TC which grew vertical to the interface in iPP layers. Compared with traditional blending sample which had only β‐spherulites, the crystallization rate, and Avrami exponent of β‐crystal in layered samples decreased with increasing of the β‐TC content due to the longer induction nucleation time and two‐dimensional heterogeneous growth mode of β‐TC during isothermal crystallization at 130°C. Similarly, the crystallization rate of β‐crystals decreased with the increase of β‐TC content during nonisothermal crystallization. In addition, the layered sample with high content of β‐TC showed good toughness, due to the special morphology of β‐TC. This study provided a method to fabricate β‐TC during melt processing, and promoting the application of iPP materials with high‐content of β‐TC. POLYM. ENG. SCI., 58:1791–1799, 2018. © 2017 Society of Plastics Engineers