bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interaction Stability Analysis of a Multi-Inverter System Containing Different Types of Inverters
Authors: Zheng Chen , Li Qionglin , Zhou Lin , Li Bin , Mao Mingxuan
Published: August 2018

The existing stability investigations of the system containing different types of inverters are insufficient. The paper aims to reveal the more universal interaction stability mechanism of the system containing different types of inverters. Firstly, the multi-inverter system is decomposed into an admittance network (AN) and excitation sources. Then, the interaction between two different inverters, as well as the interaction between the inverter and the power grid, are analyzed by the root locus method. This reveals that the stability of the interaction between the inverter and the power grid is exclusively determined by AN. However, the stability of the interaction between different inverters not only depends on AN but also relies on whether the two inverters have common right-half plane (RHP) poles. To make the multi-inverter system stable, the following two criteria must be satisfied: (a) AN is stable and (b) any two different inverters do not have the same RHP poles. If criterion (a) is not satisfied, the harmonic resonance will arise in all currents. Resonant harmonics will only circulate among partial inverters and will not inject into the power grid if criterion (a) is satisfied but criterion (b) is not satisfied. Theoretical analysis is validated by simulation and experiment results.
Electric Fields in Energy and Process Engineering
Authors: Zigan Lars
Published: August 2018

This Editorial provides an introduction to and an overview of the special issue “Electric Fields in Energy and Process Engineering”.
Transient Faults in Wind Energy Conversion Systems: Analysis, Modelling Methodologies and Remedies
Authors: Abubakar Ukashatu , Mekhilef Saad , Mokhlis Hazlie , Seyedmahmoudian Mehdi , Horan Ben , Stojcevski Alex , Bassi Hussain , Hosin Rawa Muhyaddin Jamal
Published: August 2018

This paper presents an in-depth review of classical and state-of-the-art models for analysing the transient stability in wind energy conversion systems. Various transient simulation models for a number of wind turbine generator (WTG) configurations are introduced, under different disturbances. The mitigation is achieved, by manipulating the generator speed and power electronics control, whereas the protection is implemented using conventional, intelligent or digital relays for the safety of sensitive components, in case of transient fault occurrence. The various control systems in WECS are basically employed to transform and regulate the varying frequency, owing to the stochastic nature of wind speed, to the standard 50-Hz or 60-Hz frequency for coupling to an existing electrical utility grid. It has been observed that the control and protection schemes in wind energy systems are concurrently applied. Transient faults in WECSs are a dominant power quality problem especially in the doubly-fed induction generator (DFIG), and often classified as overcurrent or overvoltage transients. These transients are measured using the transient stability index and analysed using the EMTDC/PSCAD software. In addition, the inertia of the rotating masses of wind turbine generators is often characterized by a transient torque, which generates oscillations in power systems.
Unsupervised Fault Detection and Analysis for Large Photovoltaic Systems Using Drones and Machine Vision
Authors: Alsafasfeh Moath , Abdel-Qader Ikhlas , Bazuin Bradley , Alsafasfeh Qais , Su Wencong
Published: August 2018

One of the most important sources of clean energy in the future is expected to be solar energy which is considered a real time source. Research efforts to optimize solar energy utilization are mainly concentrated on the components of solar energy systems. Photovoltaic (PV) modules are considered the main components of solar energy systems and PVs’ operations typically occur without any supervisory mechanisms, which means many external and/or internal obstacles can occur and hinder a system’s efficiency. To avoid these problems, the paper presents a system to address and detect the faults in a PV system by providing a safer and more time efficient inspection system in real time. In this paper, we proposing a real time inspection and fault detection system for PV modules. The system has two cameras, a thermal and a Charge-Coupled Device CCD. They are mounted on a drone and they used to capture the scene of the PV modules simultaneously while the drone is flying over the solar garden. A mobile PV system has been constructed primarily to validate our real time proposed system and for the proposed method in the Digital Image and Signal Processing Laboratory (DISPLAY) at Western Michigan University (WMU). Defects have been detected accurately in the PV modules using the proposed real time system. As a result, the proposed drone mounted system is capable of analyzing thermal and CCD videos in order to detect different faults in PV systems, and give location information in terms of panel location by longitude and latitude.
Direct Phase Angle and Voltage Amplitude Model Predictive Control of a Power Converter for Microgrid Applications
Authors: Nguyen Thai-Thanh , Yoo Hyeong-Jun , Kim Hak-Man , Nguyen-Duc Huy
Published: August 2018

Several control strategies of the finite control set model predictive controls (FCS-MPC) have been proposed for power converters, such as predictive current control (PCC), direct predictive power control (DPPC), and predictive voltage control (PVC). However, for microgrid (MG) applications, the control strategy of the FCS-MPC for a power converter might be changed according to the operation mode of the MG system, which results in a transient response in the system voltage or current during the mode transition. This study proposes a new control strategy of FCS-MPC for use in both islanded and grid-connected operation modes of an MG system. Considering the characteristic of a synchronous generator, a direct phase angle and voltage amplitude model predictive control (PAC) of a power converter is proposed in this study for MG applications. In the islanded mode, the system frequency is directly controlled through the phase angle of the output voltage. In the grid-connected mode, a proportional-integral (PI) regulator is used to compensate for the phase angle and voltage amplitude of the power converter for constant power control. The phase angle of the system voltage can be easily adjusted for the synchronization process of an MG system. A comparison study on the proposed PAC method and existing predictive methods is carried out to show the effectiveness of the proposed method. The feasibility of the proposed PAC strategy is evaluated in a simulation-based system by using the MATLAB/Simulink environment.
25 Years of Criteria and Indicators for Sustainable Forest Management: Why Some Intergovernmental C&I Processes Flourished While Others Faded
Authors: Linser Stefanie , Wolfslehner Bernhard , Asmar Fady , Bridge Simon R. J. , Gritten David , Guadalupe Vicente , Jafari Mostafa , Johnson Steven , Laclau Pablo , Robertson Guy
Published: August 2018

The use of criteria and indicators (C&I) for data collection, monitoring, assessing and reporting on sustainable forest management (SFM) has been growing since the Earth Summit in 1992, supported by eleven intergovernmental, regional and international forest-related C&I processes. The initial effort led to varying levels of implementation across countries. Several processes never went much beyond the adoption of a first set of C&I while others have made substantial progress. In recent years, interest in C&I for SFM has again increased. In light of the Sustainable Development Goals and emerging global challenges the contribution of C&I to monitor, assess and report on forest conditions and trends is increasingly important. We compare and analyse the structure, activities and progress of the intergovernmental C&I processes. The work is based on document analysis and questionnaires sent to the secretariats of the processes and C&I experts. We found many similarities but also major differences in the structure and content of the C&I sets. The results provide a context for discussing and understanding why some of the C&I processes are successful in their work while others have stalled. Finally, we propose the required ingredients for success for the future activities of the forest-related intergovernmental C&I processes.
Bioinformatics Tools and Benchmarks for Computational Docking and 3D Structure Prediction of RNA-Protein Complexes
Authors: Nithin Chandran , Ghosh Pritha , Bujnicki Janusz M.
Published: August 2018

RNA-protein (RNP) interactions play essential roles in many biological processes, such as regulation of co-transcriptional and post-transcriptional gene expression, RNA splicing, transport, storage and stabilization, as well as protein synthesis. An increasing number of RNP structures would aid in a better understanding of these processes. However, due to the technical difficulties associated with experimental determination of macromolecular structures by high-resolution methods, studies on RNP recognition and complex formation present significant challenges. As an alternative, computational prediction of RNP interactions can be carried out. Structural models obtained by theoretical predictive methods are, in general, less reliable compared to models based on experimental measurements but they can be sufficiently accurate to be used as a basis for to formulating functional hypotheses. In this article, we present an overview of computational methods for 3D structure prediction of RNP complexes. We discuss currently available methods for macromolecular docking and for scoring 3D structural models of RNP complexes in particular. Additionally, we also review benchmarks that have been developed to assess the accuracy of these methods.
Gender, Language and a Lipstick: Creating Cultural Change in a World of Paradoxes
Authors: Alvanoudi Angeliki
Published: August 2018

This paper addresses the paradoxes and possibilities for academic feminism in the Third Millennium drawing on feminist linguistics. It targets the role of language in the construction of social gender, focusing on data from Greek, and shows that gendering discourse can effect cultural change. It is suggested that academic feminists can be agents of cultural change when they promote feminist language reform in the service of challenging the dominant gender order.
Neuropsychiatric Lyme Borreliosis: An Overview with a Focus on a Specialty Psychiatrist’s Clinical Practice
Authors: Bransfield Robert C.
Published: August 2018

There is increasing evidence and recognition that Lyme borreliosis (LB) causes mental symptoms. This article draws from databases, search engines and clinical experience to review current information on LB. LB causes immune and metabolic effects that result in a gradually developing spectrum of neuropsychiatric symptoms, usually presenting with significant comorbidity which may include developmental disorders, autism spectrum disorders, schizoaffective disorders, bipolar disorder, depression, anxiety disorders (panic disorder, social anxiety disorder, generalized anxiety disorder, posttraumatic stress disorder, intrusive symptoms), eating disorders, decreased libido, sleep disorders, addiction, opioid addiction, cognitive impairments, dementia, seizure disorders, suicide, violence, anhedonia, depersonalization, dissociative episodes, derealization and other impairments. Screening assessment followed by a thorough history, comprehensive psychiatric clinical exam, review of systems, mental status exam, neurological exam and physical exam relevant to the patient’s complaints and findings with clinical judgment, pattern recognition and knowledgeable interpretation of laboratory findings facilitates diagnosis. Psychotropics and antibiotics may help improve functioning and prevent further disease progression. Awareness of the association between LB and neuropsychiatric impairments and studies of their prevalence in neuropsychiatric conditions can improve understanding of the causes of mental illness and violence and result in more effective prevention, diagnosis and treatment.
A Randomized Controlled Trial of a Theory-Informed School-Based Intervention to Prevent Waterpipe Tobacco Smoking: Changes in Knowledge, Attitude, and Behaviors in 6th and 7th Graders in Lebanon
Authors: Nakkash Rima , Lotfi Tamara , Bteddini Dima , Haddad Pascale , Najm Hala , Jbara Lina , Alaouie Hala , Al Aridi Lama , Al Mulla Ahmad , Mahfoud Ziyad , Afifi Rima A.
Published: August 2018

Waterpipe tobacco smoking (WTS) is spreading worldwide. Research has indicated health consequences of WTS similar to cigarettes. Prevalence of WTS is high among young people. In Lebanon, current use rates of 35% have been documented among 13–15 year olds. We evaluated a school-based intervention. Method: We conducted a randomized-controlled-trial of a theory-informed WTS intervention. The intervention consisted of ten sessions based on social cognitive theory and the social influences approach. Thirty-one schools participated: 14 intervention and 17 control; a total of 1279 students completed pre and post assessments. We measured knowledge, attitudes and self-reported behaviors related to WTS using Chi-square tests and regression analyses to compare results between the two study arms. Results: The intervention increased knowledge of intervention group compared to control group participants—about WTS constituents and health consequences; and shifted attitudes of intervention group participants to be even more unfavorable towards WTS. We found no impact of the intervention on WTS behaviors. Discussion: The effectiveness of the intervention on knowledge and attitudes supports previous research. The lack of intervention effect on behavior is not surprising given the timing of the post assessment immediately after the intervention, and the social context that was supportive of waterpipe use.
Socio-Demographic, Health and Lifestyle Factors Influencing Age of Sexual Initiation among Adolescents
Authors: Burke Lorraine , Nic Gabhainn Saoirse , Kelly Colette
Published: August 2018

Behavioural and developmental factors mean that adolescents who initiate sexual intercourse early may be at an increased risk of adverse sexual health outcomes at the time of first sex and later in life. In an Irish context, there is insufficient knowledge about the specific correlates of early sexual initiation. This research explores relationships between contextual socio-demographic, health and lifestyle factors and the timing of first sexual intercourse among 15–17-year-olds in Ireland. Multiple regression analysis was carried out in conjunction with Multiple Imputation using data collected through the 2014 Health Behaviour in School-Aged Children Ireland study on a sample of 879 sexually active adolescents. The socio-demographic and lifestyle factors measured were a stronger predictor of age of sexual initiation among girls than boys. Risk behaviour initiation was significantly related to age of sexual initiation for adolescents, while alcohol use/drunkenness and unhealthy food consumption was significant among girls only. Family support and number of male friends were significant predictors for boys only. The study highlights the need for holistic approaches to sexual health promotion and provides a foundation for the development of alternative strategies and policies aimed at reducing negative health, well-being, educational and economic outcomes.
Nesting Patterns of Loggerhead Sea Turtles (Caretta caretta): Development of a Multiple Regression Model Tested in North Carolina, USA
Authors: Halls Joanne N. , Randall Alyssa L.
Published: August 2018

Numerous environmental conditions may influence when a female Loggerhead sea turtle (Caretta caretta) selects a nesting site. Limited research has used Geographic Information Systems (GIS) and statistical analysis to study sea turtle spatial patterns and temporal trends. Therefore, the goals of this research were to identify areas that were most prevalent for nesting and to test social and environmental variables to create a nesting suitability predictive model. Data were analyzed at all barrier island beaches in North Carolina, USA (515 km) and several variables were statistically significant: distance to hardened structures, beach nourishment, house density, distance to inlets, and beach elevation, slope, and width. Interestingly, variables that were not significant were population density, proximity to the Gulf Stream, and beach aspect. Several statistical techniques were tested and Negative Binomial Distribution produced good regional results while Geographically Weighted Regression models successfully predicted the number of nests with an average of 75% of the variance explained. Therefore, the combination of traditional and spatial statistics provided insightful predictive modeling results that may be incorporated into management strategies and may have important implications for the designation of critical Loggerhead nesting habitats.
Close-Range Photogrammetry and Infrared Imaging for Non-Invasive Honeybee Hive Population Assessment
Authors: López-Fernández Luis , Lagüela Susana , Rodríguez-Gonzálvez Pablo , Martín-Jiménez José Antonio , González-Aguilera Diego
Published: August 2018

Close-range photogrammetry and thermographic imaging techniques are used for the acquisition of all the data needed for the non-invasive assessment of a honeybee hive population. Temperature values complemented with precise 3D geometry generated using novel close-range photogrammetric and computer vision algorithms are used for the computation of the inner beehive temperature at each point of its surface. The methodology was validated through its application to three reference beehives with different population levels. The temperatures reached by the exterior surfaces of the hives showed a direct correlation with the population level. In addition, the knowledge of the 3D reality of the hives and the position of each temperature value allowed the positioning of the bee colonies without the need to open the hives. This way, the state of honeybee hives regarding the growth of population can be estimated without disturbing its natural development.
Achieving Complete and Near-Lossless Conversion from IFC to CityGML
Authors: Stouffs Rudi , Tauscher Helga , Biljecki Filip
Published: August 2018

The Singapore Government has embarked on a project to establish a three-dimensional city model and collaborative data platform for Singapore. The research herein contributes to this endeavour by developing a methodology and algorithms to automate the conversion of Building Information Models (BIM), in the Industry Foundation Classes (IFC) data format, into CityGML building models, capturing both geometric and semantic information as available in the BIM models, and including exterior as well as interior structures. We adopt a Triple Graph Grammar (TGG) to formally relate IFC and CityGML, both semantically and geometrically, and to transform a building information model, expressed as an IFC object graph, into a city model expressed as a CityGML object graph. The work pipeline includes extending the CityGML data model with an Application Domain Extension (ADE), which allows capturing information from IFC that is relevant in the geospatial context but at the same time not supported by CityGML in its standard form. In this paper, we elaborate on the triple graph grammar approach and the motivation and roadmap for the development of the ADE. While a fully complete and lossless conversion may never be achieved, this paper suggests that both a TGG and an ADE are natural choices for supporting the conversion between IFC and CityGML.
Chitosan–Carboxymethylcellulose-Based Polyelectrolyte Complexation and Microcapsule Shell Formulation
Authors: Roy Jagadish Chandra , Ferri Ada , Giraud Stéphane , Jinping Guan , Salaün Fabien
Published: August 2018

Chitosan (CH)–carboxymethyl cellulose sodium salt (NaCMC) microcapsules containing paraffin oil were synthesized by complex formation, and crosslinked with glutaraldehyde (GTA). The electrostatic deposition of NaCMC onto the CH-coated paraffin oil emulsion droplets was demonstrated by zeta potential and optical microscopy. The optimal process conditions were identified in terms of pH of the aqueous solution (5.5) and CH/NaCMC mass ratio (1:1). Encapsulation of paraffin oil and microcapsule morphology were analyzed by ATR-FTIR and SEM, respectively. The effect of GTA crosslinking on paraffin oil latent heat was investigated by DSC and combined with the values of encapsulation efficiency and core content, supporting the compact shell formation.
Identification of an Essential Cytoplasmic Region of Interleukin-7 Receptor α Subunit in B-Cell Development
Authors: Kasai Hirotake , Kuwabara Taku , Matsui Yukihide , Nakajima Koichi , Kondo Motonari
Published: August 2018

Interleukin-7 (IL-7) is essential for lymphocyte development. To identify the functional subdomains in the cytoplasmic tail of the IL-7 receptor (IL-7R) α chain, here, we constructed a series of IL-7Rα deletion mutants. We found that IL-7Rα-deficient hematopoietic progenitor cells (HPCs) gave rise to B cells both in vitro and in vivo when a wild-type (WT) IL-7Rα chain was introduced; however, no B cells were observed under the same conditions from IL-7Rα-deficient HPCs with introduction of the exogenous IL-7Rα subunit, which lacked the amino acid region at positions 414–441 (d414–441 mutant). Signal transducer and activator of transcription 5 (STAT5) was phosphorylated in cells with the d414–441 mutant, similar to that in WT cells, in response to IL-7 stimulation. In contrast, more truncated STAT5 (tSTAT5) was generated in cells with the d414–441 mutant than in WT cells. Additionally, the introduction of exogenous tSTAT5 blocked B lymphopoiesis but not myeloid cell development from WT HPCs in vivo. These results suggested that amino acids 414–441 in the IL-7Rα chain formed a critical subdomain necessary for the supportive roles of IL-7 in B-cell development.
Cardiovascular Benefits of Exercise Training in Postmenopausal Hypertension
Authors: Lin Yi-Yuan , Lee Shin-Da
Published: August 2018

Exercise training is often considered the cornerstone of nonpharmacological therapy for postmenopausal hypertension while aerobic exercise is the mainstay of life style modification for antihypertension. Moderate-intensity aerobic exercise is well tolerated on most days of the week by most people with postmenopausal hypertension and is not suspected to detract from exercise adherence. That being said, moderate aerobic exercise may be superior for eliciting cardiovascular benefits in hypertensive postmenopausal women and resistance exercise may offer desirable benefits. The beneficial outcomes of exercise training for hypertensive postmenopausal women include improvements in blood pressure, autonomic tone, baroreflex sensitivity, oxidative stress, nitric oxide (NO), bioavailability, and lipid profiles, as well as cardiovascular function and cardiorespiratory fitness. This partly explains the fact that exercise training programs have a positive effect for cardiovascular disease in hypertensive postmenopausal women. This review is to collect and present the literature of exercise training in postmenopausal hypertension. Our review may provide the current understanding of beneficial effects and mechanisms of exercise intervention for prevention and treatment of stage 1 to 2 hypertensive postmenopausal women.
Variation in MicroRNA Expression Profile of Uterine Leiomyoma with Endometrial Cavity Distortion and Endometrial Cavity Non-Distortion
Authors: Kim Yong Jin , Kim Yoon Young , Shin Jung Ho , Kim Hoon , Ku Seung-Yup , Suh Chang Suk
Published: August 2018

The expression profile of microRNA (miRNA) in uterine leiomyoma (UL) cells is different from that in normal uterine myometrial (UM) cells. The effect of UL cells on uterine receptivity might vary according to their ability to distort the uterine endometrial cavity. However, the variation in miRNA expression profiles between endometrial cavity-distorting leiomyoma (ECDL) and endometrial cavity non-distorting leiomyoma (ECNDL) cells remains unknown. This study aimed to elucidate whether the expression profile of miRNAs in ECDL cells is dissimilar to that of ECNDL cells in uterus. Pelviscopic myomectomy was performed to obtain tissue samples of UL and their corresponding normal UM tissues (matched) from patients with UL (n = 26), among whom women with ECNDL and ECDL numbered 15 and 11, respectively. The relative expression of hsa-miR-15b, -29a, -29b, -29c, -197, and -200c as well as the candidate target genes in UL cells was compared to those in the matched UM cells using qRT-PCR to assess their ability to cause ECD. The spatial expression of miRNAs and target genes in the UL tissues was analyzed using in situ hybridization. Target gene expression was analyzed using qPCR after transfection with the mimics and inhibitors of miRNAs in UL cells. The relative expression level of miR-15b was upregulated, and the relative expression levels of miR-29a, -29b, -29c, -197, and -200c were downregulated in UL cells compared to those in UM cells. The relative expression levels of progesterone receptor, estrogen receptor, and matrix metalloproteinases (MMPs) were upregulated in UL cells compared to those in UM cells. The relative expression levels of miR-29c and -200c were downregulated, and the relative expression levels of estrogen receptor, MMPs and tissue inhibitors of metalloproteinases (TIMPs) were upregulated in ECDL cells compared to those in ECNDL cells. The expression profile of miRNAs in UL cells varied with respect to the occurrence or absence of endometrial cavity distortion. The biochemical properties of UL might be regulated by miRNAs in order to alter their effect on structural homeostasis of the uterus.
Triterpene Acid (3-O-p-Coumaroyltormentic Acid) Isolated From Aronia Extracts Inhibits Breast Cancer Stem Cell Formation through Downregulation of c-Myc Protein
Authors: Choi Hack Sun , Kim Su-Lim , Kim Ji-Hyang , Deng Hong-Yuan , Yun Bong-Sik , Lee Dong-Sun
Published: August 2018

Cancer stem cells (CSCs) are drug-resistant and radiation-resistant cancer cells that are responsible for tumor progression and maintenance, cancer recurrence, and metastasis. Targeting breast CSCs with phytochemicals is a new paradigm for cancer prevention and treatment. In this study, activity-guided fractionation from mammosphere formation inhibition assays, repeated chromatographic preparations over silica gel, preparatory thin layer chromatography, and HPLC using aronia extracts led to the isolation of one compound. Using 1H and 13C 2-dimensional nuclear magnetic resonance (NMR) as well as electrospray ionization (ESI) mass spectrometry, the isolated compound was identified as 3-O-p-coumaroyltormentic acid. This compound inhibits breast cancer cell proliferation and mammosphere formation in a dose-dependent manner and reduces the CD44high/CD24low subpopulation and aldehyde dehydrogenase (ALDH)-expressing cell population as well as the expression of the self-renewal-related genes CD44, SOX2, and OCT4. 3-O-p-Coumaroyltormentic acid preferentially reduced the protein levels of c-Myc, which is a CSC survival factor, by inducing c-Myc degradation. These findings indicate the novel utilization of 3-O-p-coumaroyltormentic acid for breast cancer therapy via disruption of c-Myc protein, which is a CSC survival factor.
Ghrelin Stimulates Endothelial Cells Angiogenesis through Extracellular Regulated Protein Kinases (ERK) Signaling Pathway
Authors: Wang Jun , He Lin , Huwatibieke Bahetiyaer , Liu Lingchao , Lan He , Zhao Jing , Li Yin , Zhang Weizhen
Published: August 2018

Adipose tissue is hyper-vascularized. Vessels in adipose tissue not only supply nutrients and oxygen to nourish adipocytes, but also provide cytokines that regulate mass and function of adipose tissue. Understanding the fundamental mechanisms how vessels modulate adipocyte functions would provide new therapeutic options for treatment of metabolic disease and obesity. In recent years, researches about ghrelin are focused on glucose and lipid metabolism, but its effect on vascular function remains uncharacterized. In the present study, ghrelin receptor gene deletion mice (Ghsr−/− mice) were used to study ghrelin-regulated vascular metabolism in white adipose tissue. Ghsr−/− mice demonstrated lower food intake, lower body weight, and resistance to high-fat diet-induced obesity. The number of vessels in white adipose tissue was decreased in Ghsr−/− mice when compared with wild type mice fed with high-fat diet. To further define ghrelin effects in vitro, we used endothelial progenitor cells from wild type and Ghsr−/− mice as well as human umbilical vein endothelial cells in our experiments. We found that ghrelin stimulated endothelial cells angiogenesis and migration through the MEK-ERK signaling pathway. [d-Lys3]-GHRP-6 and PD98059 could reverse the effects of ghrelin on endothelial cells. Our study indicates that ghrelin activates its receptor on endothelial cells to promote angiogenesis and migration via a mechanism involving the extracellular regulated protein kinases (ERK) signaling pathway.
Targeting TGF-β Signaling in Kidney Fibrosis
Authors: Isaka Yoshitaka
Published: August 2018

Renal fibrosis is the final common pathway of numerous progressive kidney diseases, and transforming growth factor-β (TGF-β) has an important role in tissue fibrosis by up-regulating matrix protein synthesis, inhibiting matrix degradation, and altering cell-cell interaction. Many strategies targeting TGF-β, including inhibition of production, activation, binding to the receptor, and intracellular signaling, have been developed. Some of them were examined in clinical studies against kidney fibrosis, and some are applied to other fibrotic diseases or cancer. Here, I review the approaches targeting TGF-β signaling in kidney fibrosis.
Macrophage Immunomodulation: The Gatekeeper for Mesenchymal Stem Cell Derived-Exosomes in Pulmonary Arterial Hypertension?
Authors: Willis Gareth R. , Fernandez-Gonzalez Angeles , Reis Monica , Mitsialis S. Alex , Kourembanas Stella
Published: August 2018

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by remodeling of the pulmonary arteries, increased pulmonary infiltrates, loss of vascular cross-sectional area, and elevated pulmonary vascular resistance. Despite recent advances in the management of PAH, there is a pressing need for the development of new tools to effectively treat and reduce the risk of further complications. Dysregulated immunity underlies the development of PAH, and macrophages orchestrate both the initiation and resolution of pulmonary inflammation, thus, manipulation of lung macrophage function represents an attractive target for emerging immunomodulatory therapies, including cell-based approaches. Indeed, mesenchymal stem cell (MSC)-based therapies have shown promise, effectively modulating the macrophage fulcrum to favor an anti-inflammatory, pro-resolving phenotype, which is associated with both histological and functional benefits in preclinical models of pulmonary hypertension (PH). The complex interplay between immune system homeostasis and MSCs remains incompletely understood. Here, we highlight the importance of macrophage function in models of PH and summarize the development of MSC-based therapies, focusing on the significance of MSC exosomes (MEx) and the immunomodulatory and homeostatic mechanisms by which such therapies may afford their beneficial effects.
Metric Learning with Dynamically Generated Pairwise Constraints for Ear Recognition
Authors: Omara Ibrahim , Zhang Hongzhi , Wang Faqiang , Hagag Ahmed , Li Xiaoming , Zuo Wangmeng
Published: August 2018

The ear recognition task is known as predicting whether two ear images belong to the same person or not. More recently, most ear recognition methods have started based on deep learning features that can achieve a good accuracy, but it requires more resources in the training phase and suffer from time-consuming computational complexity. On the other hand, descriptor features and metric learning play a vital role and also provide excellent performance in many computer vision applications, such as face recognition and image classification. Therefore, in this paper, we adopt the descriptor features and present a novel metric learning method that is efficient in matching real-time for ear recognition system. This method is formulated as a pairwise constrained optimization problem. In each training cycle, this method selects the nearest similar and dissimilar neighbors of each sample to construct the pairwise constraints and then solves the optimization problem by the iterated Bregman projections. Experiments are conducted on Annotated Web Ears (AWE) database, West Pommeranian University of Technology (WPUT), the University of Science and Technology Beijing II (USTB II), and Mathematical Analysis of Images (AMI) databases.. The results show that the proposed approach can achieve promising recognition rates in ear recognition, and its training process is much more efficient than the other competing metric learning methods.
Ddpd as Expanded Terpyridine: Dramatic Effects of Symmetry and Electronic Properties in First Row Transition Metal Complexes
Authors: Förster Christoph , Dorn Matthias , Reuter Thomas , Otto Sven , Davarci Güllü , Reich Tobias , Carrella Luca , Rentschler Eva , Heinze Katja
Published: August 2018

The 2,2′:6′:2″-terpyridine ligand has literally shaped the coordination chemistry of transition metal complexes in a plethora of fields. Expansion of the ligand bite by amine functionalities between the pyridine units in the tridentate N,N’-dimethyl-N,N’-dipyridine-2-yl-pyridine-2,6-diamine ligand (ddpd) modifies the properties of corresponding transition metal complexes, comprising redox chemistry, molecular dynamics, magnetism and luminescence. The origins of these differences between ddpd and tpy complexes will be elucidated and comprehensively summarized with respect to first row transition metal complexes with d2–d10 electron configurations. Emerging applications of these ddpd complexes complementary to those of the well-known terpyridine ligand will be highlighted.
Gorilla: An Open Interface for Smart Agents and Real-Time Power Microgrid System Simulations
Authors: Vélez-Rivera Carlos J. , Andrade Fabio , Arzuaga-Cruz Emmanuel , Irizarry-Rivera Agustín
Published: August 2018

A recurring issue when studying agent-based algorithms and strategies for Power Microgrid Systems is having to construct an interface between the agent domain and the electrical model domain being simulated. Many different tools exist for such simulations, each with its own special external interface. Although many interfacing efforts have been published before, many of them support only special cases, while others are too complex and require a long learning curve to be used for even simple scenarios. This work presents a simple programming application interface (API) that aims to provide programming access to the electrical system model for any real-time simulation tool, from any agent-based platform, or programming language. The simplicity of the interface stems from the assumption that the simulation happens in real-time and the agent domain is not being simulated. We propose four basic operations for the API: read, write, call, and subscribe/call-back. We tested these by supporting two examples. In one of the examples, we present a creative way to have the model access libraries that are not available in the simulated environment.
A Solvent-Free Approach for Converting Cellulose Waste into Volatile Organic Compounds with Endophytic Fungi
Authors: Maxwell Tyler , Blair Richard G. , Wang Yuemin , Kettring Andrew H. , Moore Sean D. , Rex Matthew , Harper James K.
Published: August 2018

Simple sugars produced from a solvent-free mechanocatalytic degradation of cellulose were evaluated for suitability as a growth medium carbon source for fungi that produce volatile organic compounds. An endophytic Hypoxylon sp. (CI-4) known to produce volatiles having potential value as fuels was initially evaluated. The growth was obtained on a medium containing the degraded cellulose as the sole carbon source, and the volatile compounds produced were largely the same as those produced from a conventional dextrose/starch diet. A second Hypoxylon sp. (BS15) was also characterized and shown to be phylogenetically divergent from any other named species. The degraded cellulose medium supported the growth of BS15, and approximately the same quantity of the volatile compounds was produced as from conventional diets. Although the major products from BS15 grown on the degraded cellulose were identical to those from dextrose, the minor products differed. Neither CI-4 or BS15 exhibited growth on cellulose that had not been degraded. The extraction of volatiles from the growth media was achieved using solid-phase extraction in order to reduce the solvent waste and more efficiently retain compounds having low vapor pressures. A comparison to more conventional liquid–liquid extraction demonstrated that, for CI-4, both methods gave similar results. The solid-phase extraction of BS15 retained a significantly larger variety of the volatile compounds than did the liquid–liquid extraction. These advances position the coupling of solvent-free cellulose conversion and endophyte metabolism as a viable strategy for the production of important hydrocarbons.
Photovoltage Reversal in Organic Optoelectronic Devices with Insulator-Semiconductor Interfaces
Authors: Hu Laigui , Jin Wei , Feng Rui , Zaheer Muhammad , Nie Qingmiao , Chen Guoping , Qiu Zhi-Jun , Cong Chunxiao , Liu Ran
Published: August 2018

Photoinduced space-charges in organic optoelectronic devices, which are usually caused by poor mobility and charge injection imbalance, always limit the device performance. Here we demonstrate that photoinduced space-charge layers, accumulated at organic semiconductor-insulator interfaces, can also play a role for photocurrent generation. Photocurrent transients from organic devices, with insulator-semiconductor interfaces, were systematically studied by using the double-layer model with an equivalent circuit. Results indicated that the electric fields in photoinduced space-charge layers can be utilized for charge generation and can even induce a photovoltage reversal. Such an operational process of light harvesting would be promising for photoelectric conversion in organic devices.
Al/Si Nanopillars as Very Sensitive SERS Substrates
Authors: Magno Giovanni , Bélier Benoit , Barbillon Grégory
Published: August 2018

In this paper, we present a fast fabrication of Al/Si nanopillars for an ultrasensitive SERS detection of chemical molecules. The fabrication process is only composed of two steps: use of a native oxide layer as a physical etch mask followed by evaporation of an aluminum layer. A random arrangement of well-defined Al/Si nanopillars is obtained on a large-area wafer of Si. A good uniformity of SERS signal is achieved on the whole wafer. Finally, we investigated experimentally the sensitivity of these Al/Si nanopillars for SERS sensing, and analytical enhancement factors in the range of 1.5 × 10 7 − 2.5 × 10 7 were found for the detection of thiophenol molecules. Additionally, 3D FDTD simulations were used to better understand optical properties of Al/Si nanopillars as well as the Raman enhancement.
Synergistic Enhancement of Thermal Conductivity and Dielectric Properties in Al2O3/BaTiO3/PP Composites
Authors: Yao Junlong , Hu Li , Zhou Min , You Feng , Jiang Xueliang , Gao Lin , Wang Qing , Sun Zhengguang , Wang Jun
Published: August 2018

Multifunctional polymer composites with both high dielectric constants and high thermal conductivity are urgently needed by high-temperature electronic devices and modern microelectromechanical systems. However, high heat-conduction capability or dielectric properties of polymer composites all depend on high-content loading of different functional thermal-conductive or high-dielectric ceramic fillers (every filler volume fraction ≥ 50%, i.e., ffiller ≥ 50%), and an overload of various fillers (fthermal-conductive filler + fhigh-dielectric filler > 50%) will decrease the processability and mechanical properties of the composite. Herein, series of alumina/barium titanate/polypropylene (Al2O3/BT/PP) composites with high dielectric- and high thermal-conductivity properties are prepared with no more than 50% volume fraction of total ceramic fillers loading, i.e., ffillers ≤ 50%. Results showed the thermal conductivity of the Al2O3/BT/PP composite is up to 0.90 W/m·K with only 10% thermal-conductive Al2O3 filler, which is 4.5 times higher than the corresponding Al2O3/PP composites. Moreover, higher dielectric strength (Eb) is also found at the same loading, which is 1.6 times higher than PP, and the Al2O3/BT/PP composite also exhibited high dielectric constant ( ε r = 18 at 1000 Hz) and low dielectric loss (tan δ ≤ 0.030). These excellent performances originate from the synergistic mechanism between BaTiO3 macroparticles and Al2O3 nanoparticles.
Fretting Wear Behavior and Photoelectron Spectroscopy (XPS) Analysis of a Ti/TiN Multilayer Film Deposited on Depleted Uranium
Authors: Zhu Shengfa , Wu Yanping , Li Zhengyang , Fang Liping , Yin Anyi , Yan Jiawei , Jiang Fan , Meng Xiandong , Chen Piheng , Cai Zhenbing
Published: August 2018

Depleted uranium has been widely applied in nuclear energy fields. However, its poor corrosion and wear resistance restrict its applications. A titanium/titanium nitride (Ti/TiN) multilayer film was deposited on a uranium surface to improve its fretting wear resistance. Fretting wear tests were carried out using a pin-on-disc configuration. The fretting behaviors of uranium and the Ti/TiN film were investigated under different normal loads. With the normal load increasing, the mode of fretting wear gradually transformed from slip region (SR) to mixed fretting region (MFR) and then to partial slip region (PSR). It is illustrated that the normal load had an obvious effect on the fretting wear behavior. The friction coefficients of both uranium and Ti/TiN multilayer film decreased with the increase of the normal load. In SR, the main wear mechanisms were delamination and abrasion for uncoated uranium, and delamination and oxidation for uranium coated with the Ti/TiN multilayer film. Photoelectron spectroscopy (XPS) analysis also showed that the Ti/TiN coating was oxidized and formed TiO2 during fretting wear. The wear depth of naked uranium was much greater than that of coated uranium, which demonstrated that the Ti/TiN multilayer film could effectively improve the wear properties of uranium.
A Facile Flow-Casting Production of Bioactive Glass Coatings on Porous Titanium for Bone Tissue Engineering
Authors: Yang Haiou , Zhu Qijie , Qi Hongfei , Liu Xianhu , Ma Meixia , Chen Qiang
Published: August 2018

Additive manufacturing enabled the fabrication of porous titanium (PT) with customized porosity and mechanical properties. However, functionalization of PT surfaces with bioactive coatings is being challenged due to sophisticated geometry and highly porous structure. In this study, a facile flow-casting technique was developed to produce homogeneous 45S5 bioactive glass (BG) coatings on the entire surface of PT. The coating weight as a function of BG concentration in a BG-PVA slurry was investigated to achieve controllable coating yield without blocking macropore structure. The annealing-treated BG coating not only exhibited compact adhesion confirmed by qualitative sonication treatment, but also enhanced the mechanical properties of PT scaffolds. Moreover, in-vitro assessments of BG-coated PT cultured with MC3T3-E1 cells was carried out having in mind their potential as bioactive bone implants. The experimental results in this study offer a simple and versatile approach for the bio-functionalization of PT and other porous biomedical devices.
Application of Fly Ash Derived Zeolites in Warm-Mix Asphalt Technology
Authors: Woszuk Agnieszka
Published: August 2018

In recent years, numerous studies have been carried out on new technologies allowing to reduce of mix asphalt production temperatures. One of the possibilities is to foam the asphalt with “water-containing” additives, which include zeolites. So far, mainly synthetic zeolites of the Linde A structure type, obtained from chemical reagents, and natural clinoptilolite have been used in WMA technology. In this studies, the synthetic zeolites produced from fly ashes with 4 different types of crystalline structure were analyzed. Zeolite materials were characterized by textural parameters and thermal analysis. The amount of zeolite added to asphalt was 0, 3, 5, 7 wt % in relation to the weight of asphalt. Determination of dynamic viscosity was performed at two temperatures: 135 and 160 and 4 time intervals. The tests were performed for two asphalt binders: 35/50 and 100/150 penetration grade. As a conclusion, it was found that the viscosity of asphalt pastes with zeolitic materials increases with the increase in the amount of zeolite added. The increase level depends mainly on the textural parameters. The potential usefulness of fly ash derived zeolites in the process of asphalt foaming, which depends mainly on the amount of water contained in the zeolite structure and the method of its release, has been proved.
Effect of Selective Laser Melting Process Parameters on Microstructure and Properties of Co-Cr Alloy
Authors: Wang Jian-Hong , Ren Jie , Liu Wei , Wu Xiao-Yu , Gao Ming-Xiang , Bai Pei-Kang
Published: August 2018

Due to the rapid melting and solidification mechanisms involved in selective laser melting (SLM), CoCrMo alloys fabricated by SLM differ from the cast form of the same alloy. In this study, the relationship between process parameters and the morphology and macromechanical properties of cobalt-chromium alloy micro-melting pools is discussed. By measuring the width and depth of the molten pool, a theoretical model of the molten pool is established, and the relationship between the laser power, the scanning speed, the scanning line spacing, and the morphology of the molten pool is determined. At the same time, this study discusses the relationship between laser energy and molding rate. Based on the above research, the optimal process for the laser melting of cobalt-chromium alloy in the selected area is obtained. These results will contribute to the development of biomedical CoCr alloys manufactured by SLM.