bluuebunny/crossref_metadata_2025 huggingface dataset:
Mobile Educational Augmented Reality Games: A Systematic Literature Review and Two Case Studies
Authors: Laine Teemu H.
Published: March 2018

Augmented reality (AR) has evolved from research projects into mainstream applications that cover diverse fields, such as entertainment, health, business, tourism and education. In particular, AR games, such as Pokémon Go, have contributed to introducing the AR technology to the general public. The proliferation of modern smartphones and tablets with large screens, cameras, and high processing power has ushered in mobile AR applications that can provide context-sensitive content to users whilst freeing them to explore the context. To avoid ambiguity, I define mobile AR as a type of AR where a mobile device (smartphone or tablet) is used to display and interact with virtual content that is overlaid on top of a real-time camera feed of the real world. Beyond being mere entertainment, AR and games have been shown to possess significant affordances for learning. Although previous research has done a decent job of reviewing research on educational AR applications, I identified a need for a comprehensive review on research related to educational mobile AR games (EMARGs). This paper explored the research landscape on EMARGs over the period 2012–2017 through a systematic literature review complemented by two case studies in which the author participated. After a comprehensive literature search and filtering, I analyzed 31 EMARGs from the perspectives of technology, pedagogy, and gaming. Moreover, I presented an analysis of 26 AR platforms that can be used to create mobile AR applications. I then discussed the results in depth and synthesized my interpretations into 13 guidelines for future EMARG developers.
Robustness Property of Robust-BD Wald-Type Test for Varying-Dimensional General Linear Models
Authors: Guo Xiao , Zhang Chunming
Published: March 2018

An important issue for robust inference is to examine the stability of the asymptotic level and power of the test statistic in the presence of contaminated data. Most existing results are derived in finite-dimensional settings with some particular choices of loss functions. This paper re-examines this issue by allowing for a diverging number of parameters combined with a broader array of robust error measures, called “robust- BD ”, for the class of “general linear models”. Under regularity conditions, we derive the influence function of the robust- BD parameter estimator and demonstrate that the robust- BD Wald-type test enjoys the robustness of validity and efficiency asymptotically. Specifically, the asymptotic level of the test is stable under a small amount of contamination of the null hypothesis, whereas the asymptotic power is large enough under a contaminated distribution in a neighborhood of the contiguous alternatives, thus lending supports to the utility of the proposed robust- BD Wald-type test.
Performance Comparison of Geobroadcast Strategies for Winding Roads
Authors: Talavera Edgar , Anaya José , Gómez Oscar , Jiménez Felipe , Naranjo José
Published: March 2018

Vehicle-to-X (V2X) communications allow real-time information sharing between vehicles and Roadside Units (RSUs). These kinds of technologies allow for the improvement of road safety and can be used in combination with other systems. Advanced Driver Assistance Systems (ADAS) are an example and can be used along with V2X communications to improve performance and enable Cooperative Systems. A key element of vehicular communications is that the information transmitted through the network is always linked to a GPS position related to origin and destination (GeoNetworking protocol) in order to adjust the data broadcast to the dynamic road environment needs. In this paper, we present the implementation and development of Institute for Automobile Research (INSIA) V2X communication modules that follow the European vehicular networking standards in a close curve in a winding road where poor visibility causes a risk to the safety of road users. The technology chosen to support these communications is ETSI ITS-G5, which has the capability to enable specific services that support GeoNetworking protocols, specifically the Geobroadcast (GBC) algorithm. These functionalities have been implemented and validated in a real environment in order to demonstrate the performance of the communication devices in real V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure) situations. GBC messages are also compared with two different configurations of emission area. A comparison with/without RSU modules in critical areas of the road with previous knowledge of the road cartography has also been made.
Thermal Rating of Offshore Wind Farm Cables Installed in Ventilated J-Tubes
Authors: You Lei , Wang Jian , Liu Gang , Ma Hui , Zheng Ming
Published: March 2018

The section of submarine cable that is installed in enclosed J-tubes represents a possible thermal limiting point along the export circuits of offshore wind farms (OWFs). To obtain higher continuous thermal ratings for J-tube systems, a ventilated design, realized by allowing for the flow of natural wind into the J-tube through vents, is considered in this paper. To evaluate the performance of this forced-ventilation design, a coupled three-dimensional (3D) numerical model is constructed using the computational fluid dynamics (CFD) technique. The CFD method is first successfully tested through comparisons with existing methods for enclosed J-tubes. Then, the cable rating for the ventilated design is determined using the CFD model and compared with the rating for the enclosed case. The results show that the cooling effect from forced ventilation is obvious, and the cable rating could be increased by up to 27.5% for a wind speed of 10 m/s. This improvement in rating is especially significant for OWFs where the export circuit output is limited by the cable rating in enclosed J-tubes.
AC and DC Impedance Extraction for 3-Phase and 9-Phase Diode Rectifiers Utilizing Improved Average Mathematical Models
Authors: Khan Shahbaz , Zhang Xiaobin , Khan Bakht , Ali Husan , Zaman Haider , Saad Muhammad
Published: March 2018

Switching models possess discontinuous and nonlinear behavior, rendering difficulties in simulations in terms of time consumption and computational complexity, leading to mathematical instability and an increase in its vulnerability to errors. This issue can be countered by averaging detailed models over the entire switching period. An attempt is made for deriving improved dynamic average models of three phase (six-pulse) and nine phase (18-pulse) diode rectifiers by approximating load current through first order Taylor series. Small signal AC/DC impedances transfer functions of the average models are obtained using a small signal current injection technique in Simulink, while transfer functions are obtained through identification of the frequency response into the second order system. For the switch models in Simulink and the experimental setup, a small signal line to line shunt current injection technique is used and the obtained frequency response is then identified into second order systems. Sufficient matching among these results proves the validity of the modelling procedure. Exact impedances of the integral parts, in interconnected AC/DC/AC systems, are required for determining the stability through input-output impedances.
Spar-Type Vertical-Axis Wind Turbines in Moderate Water Depth: A Feasibility Study
Authors: Wen Ting , Wang Kai , Cheng Zhengshun , Ong Muk
Published: March 2018

The applications of floating vertical-axis wind turbines (VAWTs) in deep water have been proposed and studied by several researchers recently. However, the feasibility of deploying a floating VAWT at a moderate water depth has not yet been studied. In this paper, this feasibility is thoroughly addressed by comparing the dynamic responses of spar-type VAWTs in deep water and moderate water depth. A short spar VAWT supporting a 5 MW Darrieus rotor at moderate water depth is proposed by following the deep spar concept in deep water. A fully coupled simulation tool, SIMO-RIFLEX-DMS code, is utilized to carry out time domain simulations under turbulent wind and irregular waves. Dynamic responses of the short spar and deep spar VAWTs are analyzed and compared, including the natural periods, wind turbine performance, platform motions, tower base bending moments, and tension of mooring lines. The statistical characteristics of the thrust and power production for both spars are similar. The comparison of platform motions and tower base bending moments demonstrate a good agreement for both spars, but the short spar has better performance in surge/sway motions and side–side bending moments. The 2P response dominates the bending moment spectra for both spars. A significant variation in tension of Mooring Line 1 and a larger corresponding spectrum value are found in the short spar concept. The results indicate that the application of short spar VAWTs is feasible and could become an alternative concept at moderate water depth.
Electromagnetic Design and Losses Analysis of a High-Speed Permanent Magnet Synchronous Motor with Toroidal Windings for Pulsed Alternator
Authors: Wan Yuan , Cui Shumei , Wu Shaopeng , Song Liwei
Published: March 2018

The configuration of conventional high-speed Permanent Magnet Synchronous Motors (PMSMs) is usually long and thin, with overlong axial end winding lengths, which is not suitable for those applications that place severe restrictions on the axial length, such as pulsed alternators. This paper first studied the key design aspects of a flat-structure high-speed PMSM. The toroidal-windings, low-conductivity material of the retaining sleeve, large airgap and segmentation of magnets were studied to reduce the axial length of the motor. The division of the stator and the employment of a non-magnetic outer stator were used to improve overall performance. Then the losses of the prototype were calculated and the factors having an influence on the losses were also investigated, after which, their effects on the total loss were evaluated. The total loss could be effectively reduced by the decrease of strand number of conductors and the division of stator, while only being slightly reduced by epoxy resin pole fillers. Metal-stack pole fillers have the same effect on the reduction of rotor loss as epoxy resin, while maintaining the good thermal-conductivity of metal. In addition, the influence of the carrier frequency of the inverter on the losses was analyzed, and it was found that high carrier frequency was helpful to reduce rotor losses. Finally, a small-scale prototype was manufactured and the experimental results were provided.
A Reduced Order Model to Predict Transient Flows around Straight Bladed Vertical Axis Wind Turbines
Authors: Le Clainche Soledad , Ferrer Esteban
Published: March 2018

We develop a reduced order model to represent the complex flow behaviour around vertical axis wind turbines. First, we simulate vertical axis turbines using an accurate high order discontinuous Galerkin–Fourier Navier–Stokes Large Eddy Simulation solver with sliding meshes and extract flow snapshots in time. Subsequently, we construct a reduced order model based on a high order dynamic mode decomposition approach that selects modes based on flow frequency. We show that only a few modes are necessary to reconstruct the flow behaviour of the original simulation, even for blades rotating in turbulent regimes. Furthermore, we prove that an accurate reduced order model can be constructed using snapshots that do not sample one entire turbine rotation (but only a fraction of it), which reduces the cost of generating the reduced order model. Additionally, we compare the reduced order model based on the high order Navier–Stokes solver to fast 2D simulations (using a Reynolds Averaged Navier–Stokes turbulent model) to illustrate the good performance of the proposed methodology.
High-Efficiency Isolated Photovoltaic Microinverter Using Wide-Band Gap Switches for Standalone and Grid-Tied Applications
Authors: Liu Yu-Chen , Chen Ming-Cheng , Yang Chun-Yu , Kim Katherine , Chiu Huang-Jen
Published: March 2018

An isolated photovoltaic micro-inverter for standalone and grid-tied applications is designed and implemented to achieve high efficiency. System configuration and design considerations, including the proposed active-clamp forward-flyback resonant converter for the DC-DC stage and a dual-frequency full-bridge inverter for the DC-AC stage, are analyzed and discussed. A prototype microinverter system is built and tested. Experimental results verify the feasibility of the proposed system, which achieves 95% power conversion efficiency at full load.
Multiwavelength Observations of Relativistic Jets from General Relativistic Magnetohydrodynamic Simulations
Authors: Anantua Richard , Blandford Roger , Tchekhovskoy Alexander
Published: March 2018

This work summarizes a program intended to unify three burgeoning branches of the high-energy astrophysics of relativistic jets: general relativistic magnetohydrodynamic (GRMHD) simulations of ever-increasing dynamical range, the microphysical theory of particle acceleration under relativistic conditions, and multiwavelength observations resolving ever-decreasing spatiotemporal scales. The process, which involves converting simulation output into time series of images and polarization maps that can be directly compared to observations, is performed by (1) self-consistently prescribing models for emission, absorption, and particle acceleration and (2) performing time-dependent polarized radiative transfer. M87 serves as an exemplary prototype for this investigation due to its prominent and well-studied jet and the imminent prospect of learning much more from Event Horizon Telescope (EHT) observations this year. Synthetic observations can be directly compared with real observations for observational signatures such as jet instabilities, collimation, relativistic beaming, and polarization. The simplest models described adopt the standard equipartition hypothesis; other models calculate emission by relating it to current density or shear. These models are intended for application to the radio jet instead of the higher frequency emission, the disk and the wind, which will be subjects of future investigations.
Studying Microquasars with X-Ray Polarimetry
Authors: Matt Giorgio , Tamborra Francesco
Published: March 2018

Microquasars are Galactic black hole systems in which matter is transferred from a donor star and accretes onto a black hole of, typically, 10–20 solar masses. The presence of an accretion disk and a relativistic jet made them a scaled down analogue of quasars—thence their name. Microquasars feature prominently in the scientific goals of X-ray polarimeters, because a number of open questions, which are discussed in this paper, can potentially be answered: the geometry of the hot corona believed to be responsible for the hard X-ray emission; the role of the jet; the spin of the black hole.
Mineralogy of Non-Silicified Fossil Wood
Authors: Mustoe George E.
Published: March 2018

The best-known and most-studied petrified wood specimens are those that are mineralized with polymorphs of silica: opal-A, opal-C, chalcedony, and quartz. Less familiar are fossil woods preserved with non-silica minerals. This report reviews discoveries of woods mineralized with calcium carbonate, calcium phosphate, various iron and copper minerals, manganese oxide, fluorite, barite, natrolite, and smectite clay. Regardless of composition, the processes of mineralization involve the same factors: availability of dissolved elements, pH, Eh, and burial temperature. Permeability of the wood and anatomical features also plays important roles in determining mineralization. When precipitation occurs in several episodes, fossil wood may have complex mineralogy.
Correlates of Objective Social Isolation from Family and Friends among Older Adults
Authors: Chatters Linda , Taylor Harry , Nicklett Emily , Taylor Robert
Published: March 2018

This study examined the correlates of objective social isolation from extended family members and friends among older adults. The analysis is based on the older adult sub-sample of the National Survey of American Life (n = 1321). Multinomial logistic regression analyses examined race/ethnicity, demographics, functional health and family and friend network factors as correlates of objective isolation from family and friends. Only 4.47% of respondents were objectively isolated from both their extended family and friends, 10.82% were isolated from their friends, and 7.43% were isolated from their family members. Men were more likely to be objectively isolated from both family and friends and older adults who live with others were significantly more likely to be objectively isolated from their friends. When controlling for subjective social isolation, the two measures of functional health were significantly associated with objective social isolation. In particular, higher levels of self-care impairment decreased the risk of being objectively isolated from friends only, whereas higher mobility impairment was associated with an increased likelihood of being objectively isolated from friends only. Subjective evaluations of social isolation from family and friends were consistently associated with being objectively isolated from family and friends. There were no significant differences between African-Americans, Black Caribbeans and non-Hispanic Whites in objective isolation. These and other findings are discussed in detail.
Assessing the Use of Media Reporting Recommendations by the World Health Organization in Suicide News Published in the Most Influential Media Sources in China, 2003–2015
Authors: Chu Xin , Zhang Xingyi , Cheng Peixia , Schwebel David , Hu Guoqing
Published: March 2018

Public media reports about suicide are likely to influence the population’s suicidal attempts and completed suicides. Irresponsible reports might trigger copycat suicidal behaviors, while responsible reports may help reduce suicide rates. The World Health Organization (WHO) released recommendations to encourage responsible suicide reports in 2008. However, little is known about whether these recommendations are reflected in the suicide news for most countries, including China. In this study, we assessed the responsibility of suicide stories published in the most influential newspaper and Internet media sources in China from 2003 to 2015, using the media reporting recommendations by the World Health Organization (WHO). In total, 3965 and 1836 eligible stories from newspaper and Internet-based media, respectively, were included in the study. Newspapers and Internet-based media performed similarly in applying WHO recommendations to report suicide news. Three recommendations were applied in over 88% of suicide stories. However, four recommendations were seldom applied, including offering information about where to seek help and linking the suicide event to mental disorders. Government and the journalism industry should work together to improve media reporting of news about suicide in China.
Assessment of Metalloid and Metal Contamination in Soils from Hainan, China
Authors: Liao Xiangjun , Zhang Chao , Sun Guangyi , Li Zhonggen , Shang Lihai , Fu Yangrong , He Yusheng , Yang Yi
Published: March 2018

The characterization of the concentrations and sources of metals and metalloids in soils is necessary to establish quality standards on a regional level and to assess the potential threat of metals to food safety and human health. A total of 8713 soil samples throughout Hainan Island, China were collected at a density of one sample per 4 km2, and concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn were analyzed. The geometric mean values of the elements were 2.17, 0.60, 26.5, 9.43, 0.033, 8.74, 22.2, 0.26, and 39.6 mg·· kg−1 for As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn, respectively, significantly lower than the background values of Chinese soils with the exception of Se. Principal component analysis (PCA) suggested that multiple anthropogenic sources regulated the elemental compositions of the Hainan environment. Coal combustion and mining are important anthropogenic sources of metals for Hainan. The geochemical maps of elements in Hainan soils were produced using the Geographic Information System (GIS) method, and several hot-spot areas were identified. The ecological impact of As, Cd, Cu, Cr, Hg, Pb, Ni, and Zn pollution to the soils was extremely “low”.
The Emerging Workforce of International University Student Workers: Injury Experience in an Australian University
Authors: Thamrin Yahya , Pisaniello Dino , Guerin Cally , Rothmore Paul
Published: March 2018

International university students are a growing section of the workforce and are thought to be at greater risk of injury. Qualitative studies have highlighted vulnerabilities, but there is a shortage of quantitative research exploring the injury experience and associated risk factors of this emerging issue. In this study, a total of 466 university student workers across a range of study programs in a single Australian university completed an online survey, with questions relating to their background, working experience, training and injury experience. Risk factors for injury were explored in a multivariate statistical model. More than half had not received any safety training before they started work, and 10% reported having had a work injury. About half of these injuries occurred after training. Statistically significant risk factors for injury included working more than 20 h per week (adjusted odds ratio 2.20 (95% CI 1.03–4.71) and lack of confidence in discussing safety issues (AOR 2.17; 95% CI 1.13–4.16). The findings suggest the need for a more engaging and effective approach to safety education and a limit on working hours. This situation is a moral challenge for universities, in that they are effectively sponsoring young workers in the community. It is recommended that longitudinal studies of international student workers be conducted.
Ageing, Health and Equity—Broad Perspectives Are Needed to Understand and Tackle Health Challenges of Ageing Societies
Authors: Zeeb Hajo , Rothgang Heinz , Darmann-Finck Ingrid
Published: March 2018

Demographic change and the evolving demands on healthcare systems, especially in the provision of healthcare and long-term care for a growing number of older people, are among the greatest social challenges of the next decades.[...]
What Can We Learn about Workplace Heat Stress Management from a Safety Regulator Complaints Database?
Authors: Hansen Alana , Pisaniello Dino , Varghese Blesson , Rowett Shelley , Hanson-Easey Scott , Bi Peng , Nitschke Monika
Published: March 2018

Heat exposure can be a health hazard for many Australian workers in both outdoor and indoor situations. With many heat-related incidents left unreported, it is often difficult to determine the underlying causal factors. This study aims to provide insights into perceptions of potentially unsafe or uncomfortably hot working conditions that can affect occupational health and safety using information provided by the public and workers to the safety regulator in South Australia (SafeWork SA). Details of complaints regarding heat exposure to the regulator’s “Help Centre” were assembled in a dataset and the textual data analysed thematically. The findings showed that the majority of calls relate to indoor work environments such as kitchens, factories, and warehouses. The main themes identified were work environment, health effects, and organisational issues. Impacts of hot working conditions ranged from discomfort to serious heat-related illnesses. Poor management practices and inflexibility of supervisors featured strongly amongst callers’ concerns. With temperatures predicted to increase and energy prices escalating, this timely study, using naturalistic data, highlights accounts of hot working conditions that can compromise workers’ health and safety and the need for suitable measures to prevent heat stress. These could include risk assessments to assess the likelihood of heat stress in workplaces where excessively hot conditions prevail.
Socio-Economic Disparities in Attitude and Preference for Menu Labels among Vietnamese Restaurant Customers
Authors: Nguyen Long , Tran Bach , Thi Nguyen Huong , Le Huong , Do Hoa , Kim Dang Anh , Nguyen Cuong , Latkin Carl , Zhang Melvyn , Ho Roger
Published: March 2018

Calories and nutrition labeling on restaurant menus are powerful policy interventions to reduce the burden of obesity epidemic. However, the success of this policy requires an assurance of equal benefits among customers with different characteristics, especially people at a higher risk of poor health outcomes and eating habits. This study examined the sociodemographic disparities in the attitude and preference for calories and nutrition labeling on menus among customers in various food facilities. A cross-sectional study was conducted with 1746 customers of food facilities in Hanoi, Vietnam, who were recruited by using a multistage sampling method. Socio-economic characteristics, attitudes regarding the necessity and preferences for calories, and nutrition labeling on menus were analyzed. Multivariate logistic regression was employed to determine the associated factors with attitudes and preferences. Results show that most of the sample understood the necessity to have calories and nutrition labeling (59.8%), and 71.8% preferred to have calories and nutrition labeling. People who often visited food facilities (Odd Ratio (OR) = 1.36; 95% confident interval (CI) = 1.06–1.74) and had higher education and were more likely to understand the necessity of calories and nutrition labeling. Factors such as being homemakers, often going to dine-in restaurants, and perceiving that labeling was unnecessary were negatively associated with preferences for calories and nutrition labeling. The results of this study encourage policymakers to implement calories and nutrition labeling in the future. Health education interventions to improve knowledge and attitude as regards calories and nutrition labeling on menus are important, particularly for males, less-educated individuals, and high-income people.
Organ and Tissue-Specific Localisation of Selected Cell Wall Epitopes in the Zygotic Embryo of Brachypodium distachyon
Authors: Betekhtin Alexander , Milewska-Hendel Anna , Lusinska Joanna , Chajec Lukasz , Kurczynska Ewa , Hasterok Robert
Published: March 2018

The plant cell wall shows a great diversity regarding its chemical composition, which may vary significantly even during different developmental stages. In this study, we analysed the distribution of several cell wall epitopes in embryos of Brachypodium distachyon (Brachypodium). We also described the variations in the nucleus shape and the number of nucleoli that occurred in some embryo cells. The use of transmission electron microscopy, and histological and immunolocalisation techniques permitted the distribution of selected arabinogalactan proteins, extensins, pectins, and hemicelluloses on the embryo surface, internal cell compartments, and in the context of the cell wall ultrastructure to be demonstrated. We revealed that the majority of arabinogalactan proteins and extensins were distributed on the cell surface and that pectins were the main component of the seed coat and other parts, such as the mesocotyl cell walls and the radicula. Hemicelluloses were localised in the cell wall and outside of the radicula protodermis, respectively. The specific arrangement of those components may indicate their significance during embryo development and seed germination, thus suggesting the importance of their protective functions. Despite the differences in the cell wall composition, we found that some of the antibodies can be used as markers to identify specific cells and the parts of the developing Brachypodium embryo.
The Balance of Th17 versus Treg Cells in Autoimmunity
Authors: Lee Gap Ryol
Published: March 2018

T helper type 17 (Th17) cells and pTreg cells, which share a common precursor cell (the naïve CD4 T cell), require a common tumor growth factor (TGF)-β signal for initial differentiation. However, terminally differentiated cells fulfill opposite functions: Th17 cells cause autoimmunity and inflammation, whereas Treg cells inhibit these phenomena and maintain immune homeostasis. Thus, unraveling the mechanisms that affect the Th17/Treg cell balance is critical if we are to better understand autoimmunity and tolerance. Recent studies have identified many factors that influence this balance; these factors range from signaling pathways triggered by T cell receptors, costimulatory receptors, and cytokines, to various metabolic pathways and the intestinal microbiota. This review article summarizes recent advances in our understanding of the Th17/Treg balance and its implications with respect to autoimmune disease.
Two New Cyathane Diterpenoids from Mycelial Cultures of the Medicinal Mushroom Hericium erinaceus and the Rare Species, Hericium flagellum
Authors: Rupcic Zeljka , Rascher Monique , Kanaki Sae , Köster Reinhard , Stadler Marc , Wittstein Kathrin
Published: March 2018

Basidiomycetes of the genus Hericium are among the most praised medicinal and edible mushrooms, which are known to produce secondary metabolites with the potential to treat neurodegenerative diseases. This activity has been attributed to the discovery of various terpenoids that can stimulate the production of nerve growth factor (NGF) or (as established more recently) brain-derived neurotrophic factor (BDNF) in cell-based bioassays. The present study reports on the metabolite profiles of a Lion’s Mane mushroom (Hericium erinaceus) strain and a strain of the rare species, Hericium flagellum (synonym H. alpestre). While we observed highly similar metabolite profiles between the two strains that were examined, we isolated two previously undescribed metabolites, given the trivial names erinacines Z1 and Z2. Their chemical structures were elucidated by means of nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry. Along with six further, previously identified cyathane diterpenes, the novel erinacines were tested for neurotrophin inducing effects. We found that erinacines act on BDNF, which is a neurotrophic factor that has been reported recently by us to be induced by the corallocins, but as well on NGF expression, which is consistent with the literature.
Vesicular Axonal Transport is Modified In Vivo by Tau Deletion or Overexpression in Drosophila
Authors: Talmat-Amar Yasmina , Arribat Yoan , Parmentier Marie-Laure
Published: March 2018

Structural microtubule associated protein Tau is found in high amount in axons and is involved in several neurodegenerative diseases. Although many studies have highlighted the toxicity of an excess of Tau in neurons, the in vivo understanding of the endogenous role of Tau in axon morphology and physiology is poor. Indeed, knock-out mice display no strong cytoskeleton or axonal transport phenotype, probably because of some important functional redundancy with other microtubule-associated proteins (MAPs). Here, we took advantage of the model organism Drosophila, which genome contains only one homologue of the Tau/MAP2/MAP4 family to decipher (endogenous) Tau functions. We found that Tau depletion leads to a decrease in microtubule number and microtubule density within axons, while Tau excess leads to the opposite phenotypes. Analysis of vesicular transport in tau mutants showed altered mobility of vesicles, but no change in the total amount of putatively mobile vesicles, whereas both aspects were affected when Tau was overexpressed. In conclusion, we show that loss of Tau in tau mutants not only leads to a decrease in axonal microtubule density, but also impairs axonal vesicular transport, albeit to a lesser extent compared to the effects of an excess of Tau.
Novel Furocoumarin Derivatives Stimulate Melanogenesis in B16 Melanoma Cells by Up-Regulation of MITF and TYR Family via Akt/GSK3β/β-Catenin Signaling Pathways
Authors: Niu Chao , Yin Li , Aisa Haji
Published: March 2018

The extracts of Ficuscarica L. and Psoralen corylifolia L. are traditional Uygur medicines for the treatment of vitiligo, and its active ingredients furocoumarins, were are found to be the most effective agents against this skin disorder nowadays. Therefore, a series of novel easter derivatives (8a–8p) of furocoumarin were designed and synthesized based on our previous research to improve this activity in the present study. The synthesized derivatives were biologically evaluated for melanin synthesis in murine B16 cells and the SAR (structure-activity relationship) was summarized. Eight derivatives were more potent than positive control (8-MOP, 8-methoxypsoralan), especially compounds 8n (200%) and 8o (197%), which were nearly 1.5-fold potency when compared with 8-MOP (136%). Furthermore, the signaling pathway by which 8n activates the melanin biosynthesis was defined. Our results showed that it not only elevated the melanin content, but also stimulated the activity of tyrosinasein a concentration-dependent manner. Increasing of phosphorylation of Akt (also named PKB, protein kinase B) and non-activated GSK3β (glycogen synthase kinase 3 beta), which inhibited the degradation of β-catenin were observed through Western blot analysis. The accumulation of β-catenin probably led to the activation of transcription of MITF (microphthalmia-associated transcription factor) and TYR (tyrosinase) family, as well as the subsequent induction of melanin synthesis.
Virtual Reality Exercise for Anxiety and Depression: A Preliminary Review of Current Research in an Emerging Field
Authors: Zeng Nan , Pope Zachary , Lee Jung , Gao Zan
Published: March 2018

Objective: Although current evidence supports the use of virtual reality (VR) in the treatment of mental disorders, it is unknown whether VR exercise would be beneficial to mental health. This review synthesized literature concerning the effect of VR exercise on anxiety and depression among various populations. Methods: Ten electronic databases were searched for studies on this topic from January 2000 through October 2017. Studies were eligible if the article: (1) was peer-reviewed; (2) was published in English; and (3) used quantitative measures in assessing anxiety- and depression-related outcomes. Results: A total of five empirical studies met the eligibility criteria. These studies included two randomized clinical trials, one control trial, and two cross-sectional studies. Four studies reported significant improvements in anxiety- and depression-related measures following VR exercise, including reduced tiredness and tension, in addition to increased energy and enjoyment. Nonetheless, one study failed to support the effectiveness of VR exercise over traditional exercise alone on depressive symptoms. Conclusions: Findings favor VR exercise in alleviating anxiety and depression symptomology. However, existing evidence is insufficient to support the advantages of VR exercise as a standalone treatment over traditional therapy in the alleviation of anxiety and depression given the paucity of studies, small sample sizes, and lack of high-quality research designs. Future studies may build upon these limitations to discern the optimal manner by which to employ VR exercise in clinical settings.
Organ Transplantation in Iran; Current State and Challenges with a View on Ethical Consideration
Authors: Kiani Mehrzad , Abbasi Mahmoud , Ahmadi Mehdi , Salehi Bahare
Published: March 2018

Organ transplantation is a new issue in medical science. It is an important achievement and a sign of the progression and ability of medical centers around the world. Governments, populations, the medical community and people involved in culture, art, and media all have a decisive role in the culture of organ donation, which is the only way to guarantee that the healthy organs of a brain-dead person can continue to work and save the lives of people in need of organ transplantation. The brain death phenomenon and its possible application in organ transplantation, while offering new hope for the salvation of a number of patients, has led to many ethical, cultural, and legal issues. Ethical issues in organ transplantation are very complicated due to many social factors such as religion, culture, and traditions of the affected communities. The ethical and legal points of removing organs from the body of a living or cadaveric source, the definition of brain death, the moral and legal conditions of the donor and the recipient, and the financial relationship between them and many others, are all critical issues in organ transplantation. While there may be no available explicit solution to these issues, they should be rigorously considered by the experts. Efforts to systematically eliminate barriers and solve problems in organ transplantation, can not only reduce the costs of maintaining brain-dead patients and encourage patients that need organ transplantation but can also prevent immoral and illegal activities. In this paper, we have reviewed the most important and current challenges in organ transplantation with a view to the ethical considerations, and we have suggested some strategies to extend it in Iran.
Amiloride Promotes Oligodendrocyte Survival and Remyelination after Spinal Cord Injury in Rats
Authors: Imai Takeshi , Katoh Hiroyuki , Suyama Kaori , Kuroiwa Masahiro , Yanagisawa Sho , Watanabe Masahiko
Published: March 2018

After spinal cord injury (SCI), secondary injury results in an expanding area of glial cell apoptosis. Oligodendrocyte precursor cells (OPCs) actively proliferate after SCI, but many of these cells undergo apoptosis. One of the factors that exacerbates secondary injury is endoplasmic reticulum (ER) stress. In this study, we tested the effects of amiloride treatment on the fate of OPCs during secondary injury in rats. Amiloride is an FDA-approved diuretic for treating hypertension, which in rats enhances ER stress response and suppresses the apoptosis of glial cells after SCI. A severe contusive SCI was induced in Sprague-Dawley rats using an infinite horizon (IH)-impactor (200 kdyne). Beginning 24 h after SCI, 10 mg/kg of amiloride or phosphate buffered saline (PBS) was intraperitoneally administered daily for a period of 14 days. At 7, 14, 28, and 56 days after SCI, animals were subsequently euthanized in order to analyze the injured spinal cord. We labeled proliferating OPCs and demonstrated that amiloride treatment led to greater numbers of OPCs and oligodendrocytes in the injured spinal cord. Increased myelin basic protein (MBP) expression levels were observed, suggesting that increased numbers of mature oligodendrocytes led to improved remyelination, significantly improving motor function recovery.
Correction: Cooper, A.; Abbass, A.; Town, J. Implementing a Psychotherapy Service for Medically Unexplained Symptoms in a Primary Care Setting. Journal of Clinical Medicine 2017, 6, 109–141
Authors: Cooper Angela , Abbass Allan , Zed Joanna , Bedford Lisa , Sampalli Tara , Town Joel
Published: March 2018

The authors wish to make the following corrections to this paper [1].[...]
Recyclable Aggregates of Mesoporous Titania Synthesized by Thermal Treatment of Amorphous or Peptized Precursors
Authors: Mascolo Maria , Ring Terry
Published: March 2018

Recyclable aggregates of mesoporous titania with different anatase–rutile ratios have been prepared by thermal treatments of either amorphous or peptized precursors. These last two have been obtained by hydrolysis of either Ti(OC2H5)4 or of Ti(OC2H5)4 in mixture with 5 mol % Zr(OC3H7)4 at room temperature in the presence of NH4OH as a catalyzing agent. The anatase–rutile ratio, the recyclable aggregates of the nano-sized particles, the mesoporosity, the surface area and the crystallinity of the resulting crystallized products of titania can be controlled by the synthesis parameters including: concentration of ammonia catalyst, stirring time and concentration of the peptizing HNO3, drying method of peptized precursors, calcination temperature, and finally the ramp rate up to the titania crystallization temperature. A broad range of synthesis parameters control the crystal sizes of titania particles produced. This allows catalyst preparation with very different crystal size, surface area, anatase to rutile crystal ratio and various mesoporous structures. Drying by lyophilization of precursors reduce the aggregation of the primary particles giving micro-/macroporous structures.
An Optical Biosensing Strategy Based on Selective Light Absorption and Wavelength Filtering from Chromogenic Reaction
Authors: Chun Hyeong , Han Yong , Park Yoo , Kim Ka , Lee Seok , Yoon Hyun
Published: March 2018

To overcome the time and space constraints in disease diagnosis via the biosensing approach, we developed a new signal-transducing strategy that can be applied to colorimetric optical biosensors. Our study is focused on implementation of a signal transduction technology that can directly translate the color intensity signals—that require complicated optical equipment for the analysis—into signals that can be easily counted with the naked eye. Based on the selective light absorption and wavelength-filtering principles, our new optical signaling transducer was built from a common computer monitor and a smartphone. In this signal transducer, the liquid crystal display (LCD) panel of the computer monitor served as a light source and a signal guide generator. In addition, the smartphone was used as an optical receiver and signal display. As a biorecognition layer, a transparent and soft material-based biosensing channel was employed generating blue output via a target-specific bienzymatic chromogenic reaction. Using graphics editor software, we displayed the optical signal guide patterns containing multiple polygons (a triangle, circle, pentagon, heptagon, and 3/4 circle, each associated with a specified color ratio) on the LCD monitor panel. During observation of signal guide patterns displayed on the LCD monitor panel using a smartphone camera via the target analyte-loaded biosensing channel as a color-filtering layer, the number of observed polygons changed according to the concentration of the target analyte via the spectral correlation between absorbance changes in a solution of the biosensing channel and color emission properties of each type of polygon. By simple counting of the changes in the number of polygons registered by the smartphone camera, we could efficiently measure the concentration of a target analyte in a sample without complicated and expensive optical instruments. In a demonstration test on glucose as a model analyte, we could easily measure the concentration of glucose in the range from 0 to 10 mM.
Anti-Cancer Activity of Phenyl and Pyrid-2-yl 1,3-Substituted Benzo[1,2,4]triazin-7-ones and Stable Free Radical Precursors
Authors: Keane Lee-Ann , Mirallai Styliana , Sweeney Martin , Carty Michael , Zissimou Georgia , Berezin Andrey , Koutentis Panayiotis , Aldabbagh Fawaz
Published: March 2018

Cell viability studies for benzo[1,2,4]triazin-7-ones and 1,2,4-benzotriazinyl (Blatter-type) radical precursors are described with comparisons made with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO). All of the stable free radicals were several orders of magnitude less cytotoxic than the benzo[1,2,4]triazin-7-ones. The synthesis and evaluation of two new pyrid-2-yl benzo[1,2,4]triazin-7-ones are described, where altering the 1,3-substitution from phenyl to pyrid-2-yl increased cytotoxicity against most cancer cell lines, as indicated using National Cancer Institute (NCI) one-dose testing. COMPARE analysis of five-dose testing data from the NCI showed very strong correlations to the naturally occurring anti-cancer compound pleurotin. COMPARE is program, which analyzes similarities in cytotoxicity data of compounds, and enables quantitative expression as Pearson correlation coefficients. Compounds were also evaluated using the independent MTT assay, which was compared with SRB assay data generated at the NCI.
A Facile One-Pot Construction of Succinimide-Fused Spiro[Pyrrolidine-2,3′-Oxindoles] via 1,3-Dipolar Cycloaddition Involving 3-Amino Oxindoles and Maleimides
Authors: Jin Lunqiang , Liang Feng
Published: March 2018

Increasing interests have been invested in the development of synthetic strategies toward the construction of spiro[pyrrolidine-2,3′-oxindole], which is the core structural skeleton in some compounds with diverse biological activities. In this work, an efficient diastereoselective 1,3-dipolar cycloaddition reaction of azomethine ylides generated in situ from 3-amino oxindoles and aldehydes with maleimides has been described. The protocol provides a facile and efficient access to structurally diverse succinimide-fused spiro[pyrrolidine-2,3′-oxindole] compounds in good to high yields (up to 93%) with moderate to excellent diastereoselectivities (up to >95:5). The relative stereochemistry of cycloaddition products has been assigned by X-ray diffraction analysis.
[18F]fallypride-PET/CT Analysis of the Dopamine D2/D3 Receptor in the Hemiparkinsonian Rat Brain Following Intrastriatal Botulinum Neurotoxin A Injection
Authors: Mann Teresa , Kurth Jens , Hawlitschka Alexander , Stenzel Jan , Lindner Tobias , Polei Stefan , Hohn Alexander , Krause Bernd , Wree Andreas
Published: March 2018

Intrastriatal injection of botulinum neurotoxin A (BoNT-A) results in improved motor behavior of hemiparkinsonian (hemi-PD) rats, an animal model for Parkinson’s disease. The caudate–putamen (CPu), as the main input nucleus of the basal ganglia loop, is fundamentally involved in motor function and directly interacts with the dopaminergic system. To determine receptor-mediated explanations for the BoNT-A effect, we analyzed the dopamine D2/D3 receptor (D2/D3R) in the CPu of 6-hydroxydopamine (6-OHDA)-induced hemi-PD rats by [18F]fallypride-PET/CT scans one, three, and six months post-BoNT-A or -sham-BoNT-A injection. Male Wistar rats were assigned to three different groups: controls, sham-injected hemi-PD rats, and BoNT-A-injected hemi-PD rats. Disease-specific motor impairment was verified by apomorphine and amphetamine rotation testing. Animal-specific magnetic resonance imaging was performed for co-registration and anatomical reference. PET quantification was achieved using PMOD software with the simplified reference tissue model 2. Hemi-PD rats exhibited a constant increase of 23% in D2/D3R availability in the CPu, which was almost normalized by intrastriatal application of BoNT-A. Importantly, the BoNT-A effect on striatal D2/D3R significantly correlated with behavioral results in the apomorphine rotation test. Our results suggest a therapeutic effect of BoNT-A on the impaired motor behavior of hemi-PD rats by reducing interhemispheric changes of striatal D2/D3R.
New Steroidal Saponins from the Rhizomes of Paris vietnamensis and Their Cytotoxicity
Authors: Liu Yang , Wang Minchang , Liu Ke , Qiu Pengcheng , Zhang Shan , Lu Yunyang , Tang Na , Tang Haifeng
Published: March 2018

Four new spirostanol saponins, named pavitnosides A–D (1–4), with six known steroidal saponins 5–10 were isolated from the rhizomes of Paris vietnamensis. Their chemical structures were determined based on extensive spectroscopic studies and chemical methods. The aglycones of pavitnoside B and pavitnoside C were not reported in previous work. The cytotoxicity of all saponins was evaluated against human glioblastoma U87MG and U251 cell lines. The new spirostanol saponin 1 displayed weak anti-proliferative activity against U87MG cell line and the known saponins 8 and 9 exhibited significant cytotoxicity against the two tumor cell lines, with IC50 values of 2.16 to 3.14 μM, but did not affect the growth of primary cultures of human astrocytes.