bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Aid for Trade Policy and Regulations on Tariff Policy Volatility: Does Institutional and Governance Quality Matter?
Authors: Gnangnon Sena Kimm
Published: January 2019

This article investigates empirically the effect of aid for trade policies and regulations on the volatility of tariffs in the recipient countries. The analysis has used an unbalanced panel dataset of 107 countries over the period from 2002 to 2015. The empirical results, based on the two-step system Generalized Methods of Moments (GMM) approach, show that aid for trade policies and regulations influences negatively and significantly tariff policy volatility in recipient countries. Additionally, the findings indicate that the better the institutional and governance quality in recipient countries, the higher is the reducing effect of aid for trade policies and regulations on tariff policy volatility. These results, therefore, suggest that a scale up of aid for trade policies and regulations to, inter alia, build the capacity of policymakers in recipient countries to contribute to reducing tariffs volatility in these countries, which would, in turn, likely benefit donor countries. Furthermore, improving domestic institutions and governance in recipient countries would further enhance the reducing impact of this aid on tariff volatility, which, once again, benefits both the recipient countries and donor countries.
Biotic Stress-Induced Priming and De-Priming of Transcriptional Memory in Arabidopsis and Apple
Authors: Gully Kay , Celton Jean-Marc , Degrave Alexandre , Pelletier Sandra , Brisset Marie-Noelle , Bucher Etienne
Published: January 2019

Under natural growth conditions, plants experience various and repetitive biotic and abiotic stresses. Salicylic acid (SA) is a key phytohormone involved in the response to biotic challenges. Application of synthetic SA analogues can efficiently prime defense responses, and leads to improved pathogen resistance. Because SA analogues can result in long-term priming and memory, we identified genes for which expression was affected by the SA analogue and explored the role of DNA methylation in this memorization process. We show that treatments with an SA analogue can lead to long-term transcriptional memory of particular genes in Arabidopsis. We found that subsequent challenging of such plants with a bacterial elicitor reverted this transcriptional memory, bringing their expression back to the original pre-treatment level. We also made very similar observations in apple (Malus domestica), suggesting that this expression pattern is highly conserved in plants. Finally, we found a potential role for DNA methylation in the observed transcriptional memory behavior. We show that plants defective in DNA methylation pathways displayed a different memory behavior. Our work improves our understanding of the role of transcriptional memory in priming, and has important implication concerning the application of SA analogues in agricultural settings.
Co-Infection by Waterborne Enteric Viruses in Children with Gastroenteritis in Nepal
Authors: Tandukar Sarmila , Sherchand Jeevan B. , Karki Surendra , Malla Bikash , Ghaju Shrestha Rajani , Bhandari Dinesh , Thakali Ocean , Haramoto Eiji
Published: January 2019

Enteric viruses are highly contagious and a major cause of waterborne gastroenteritis in children younger than five years of age in developing world. This study examined the prevalence of enteric virus infection in children with gastroenteritis to identify risk factors for co-infections. In total, 107 stool samples were collected from patients with acute gastroenteritis along with samples of their household drinking water and other possible contamination sources, such as food and hand. The presence of major gastroenteritis-causing enteric virus species (group A rotaviruses, enteroviruses, adenoviruses, and noroviruses of genogroup I) in stool and water samples was examined using quantitative polymerase chain reaction. Among the 107 stool samples tested, 103 (96%) samples contained at least one of the four tested enteric viruses, and the combination of group A rotaviruses and enteroviruses was the most common co-infection (52%, n = 54/103). At least one viral agent was detected in 16 (16%) of 103 drinking water samples. Identical enteric viruses were detected in both the stool and water samples taken from the same patients in 13% of cases (n = 13/103). Group A rotaviruses were most frequently found in children suffering from acute diarrhea. No socio-demographic and clinical factors were associated with the risk of co-infection compared with mono-infection. These less commonly diagnosed viral etiological agents in hospitals are highly prevalent in patients with acute gastroenteritis.
Is Childhood Overweight/Obesity Perceived as a Health Problem by Mothers of Preschool Aged Children in Bangladesh? A Community Level Cross-Sectional Study
Authors: Hossain Mohammad Sorowar , Siddiqee Mahbubul H. , Ferdous Shameema , Faruki Marzia , Jahan Rifat , Shahik Shah Md. , Raheem Enayetur , Okely Anthony D.
Published: January 2019

Childhood obesity is rapidly rising in many developing countries such as Bangladesh; however, the factors responsible for this increase are not well understood. Being the primary caregivers of children, particularly in developing countries, maternal perceptions and knowledge could be important factors influencing the weight status of children. This study aimed to assess maternal perceptions of childhood obesity and associated socio-demographic factors in Bangladesh. A cross-sectional study using stratified random sampling was conducted among 585 mothers whose children aged 4 to 7 years attended preschools in a district town. Body Mass Index of the children was calculated and weight status categorized according to the Centers for Disease Control (CDC) criteria. Maternal perceptions were assessed using a self- or interviewer-administered questionnaire. Multinomial logistic regression was used to obtain crude and adjusted odds ratios. Fourteen percent of children were overweight or obese and approximately 30% were underweight. Only 3.1% of children were perceived as overweight/obese by their mothers. Over one-third (35%) of mothers perceived that childhood overweight/obesity could be a health problem and over two-thirds (68.6%) were not aware of any health consequences of childhood obesity. Maternal perceptions were significantly associated with maternal education, family income, and weight status of the child but were not associated with the sex of the child. We have identified knowledge gaps regarding maternal perception of childhood obesity and its contributing factors in a developing country. These findings can be used to develop and test parent-focused educational interventions for preventing childhood obesity in Bangladesh.
Maternal Parenting Styles and Glycemic Control in Children with Type 1 Diabetes
Authors: Hannonen Riitta , Aunola Kaisa , Eklund Kenneth , Ahonen Timo
Published: January 2019

The purpose of this study is to examine differences in parenting styles between mothers of children with type 1 diabetes and mothers of healthy children and to explore relationships between parenting styles and glycemic control of children with diabetes. Mothers of 63 children with diabetes and mothers of 83 children without diabetes reported their parenting styles using the Blocks’ Child Rearing Practices Report, when their child was 9–10 years old. Glycemic control of the children with diabetes was evaluated 1 year after diagnosis (<6 years of age) and at the time of the study (at 9–10 years). Mothers of children with diabetes used more psychological control than mothers of healthy children. Among girls with diabetes, poorer early glycemic control was associated with mothers’ subsequent greater use of psychological control. Behavioral control was positively associated with poorer current glycemic control. In boys, psychological control was positively associated with poorer current glycemic control. Psychological control in families with diabetes needs attention, because it has shown to be associated with poorer diabetes care.
Psychometric Properties of the Spanish Version of the Caregiver Burden Inventory
Authors: Vázquez Fernando L. , Otero Patricia , Simón Miguel A. , Bueno Ana M. , Blanco Vanessa
Published: January 2019

Although the Caregiver Burden Inventory (CBI) is the most widely used multidimensional burden instrument for assessing perceived burden of caregivers, there is no data on its psychometric properties in Spanish, nor on caregivers of dependent persons with various diseases. The objective of this study was to translate the CBI into Spanish and validate it in caregivers of dependent persons with various diseases. Trained evaluators administered the CBI and assessed emotional distress and probable mental disorder in 201 caregivers (87.1% women, mean age 56.2 years). The internal consistency of the CBI was 0.89 (0.74–0.83 among the subscales). There was a significant correlation of emotional distress with both the total burden and each subscale (p < 0.001 in all cases). A total score of 39 and scores of 16, 9, 8, 4, and 2 in burden per time dedicated to care, personal life burden, physical burden, social burden, and emotional burden were suitable cut-off points to discriminate caregivers with probable mental disorder (sensitivity = 63.0%–75.6%, specificity = 63.4%–74.4%). To achieve a greater goodness of fit, the model was re-specified, resulting in a shortened (15-item) instrument. The internal consistency reliability coefficients of the 15-item CBI were satisfactory (Cronbach α = 0.83; 0.77–0.86 among the subscales). Within the 15-item CBI, emotional distress was significantly correlated with the total burden, personal life burden, physical burden, social burden (p < 0.001 in all those cases), and emotional burden (p = 0.001). A total score of 25 and scores of 12, 5, 5, 3, and 1, respectively, in the subscales were identified as cut-off points to discriminate caregivers with probable mental disorder (sensitivity = 46.2%–70.6%, specificity = 43.9%–79.3%). Therefore, the 15-item CBI validly measured caregiver burden with better fit and more parsimoniously than the original CBI.
Visual Object Tracking Robust to Illumination Variation Based on Hyperline Clustering
Authors: Yang Senquan , Xie Yuan , Li Pu , Wen Haoxiang , Luo Huan , He Zhaoshui
Published: January 2019

Color histogram-based trackers have obtained excellent performance against many challenging situations. However, since the appearance of color is sensitive to illumination, they tend to achieve lower accuracy when illumination is severely variant throughout a sequence. To overcome this limitation, we propose a novel hyperline clustering based discriminant model, an illumination invariant model that is able to distinguish the object from its surrounding background. Furthermore, we exploit this model and propose an anchor based scale estimation to cope with shape deformation and scale variation. Numerous experiments on recent online tracking benchmark datasets demonstrate that our approach achieve favorable performance compared with several state-of-the-art tracking algorithms. In particular, our approach achieves higher accuracy than comparative methods in the illumination variant and shape deformation challenging situations.
Effect of Carbon Nanotube Deposition Time to the Surface of Carbon Fibres on Flexural Strength of Resistance Welded Carbon Fibre Reinforced Thermoplastics Using Carbon Nanotube Grafted Carbon Fibre as Heating Element
Authors: Tanaka Kazuto , Nishikawa Takanobu , Aoto Kazuhiro , Katayama Tsutao
Published: January 2019

In recent years, carbon fibre reinforced thermoplastics (CFRTP) are expected to be used as lightweight structural materials for mass-produced vehicles. CFRTP with thermoplastics as matrix allows us to weld them using melting of matrix by heating. We have been developing a direct resistance heating method, which uses carbon fibres as the resistance heating element. Carbon nanotube (CNT) is expected to be used as additive to FRP and we reported that the fibre/matrix interfacial shear strength was improved by grafting CNT on the surface of carbon fibres and tensile lap-shear strength was improved by using CNT grafted carbon fibre as the heating element for welding. For the practical use of CFRTP for structural parts, flexural strength is also necessary to be evaluated. In this study, flexural test was carried out to clarify the effect of CNT deposition time to the surface of carbon fibres on flexural strength of resistance welded CFRTP using CNT grafted carbon fibre as the heating element. The highest flexural strength was obtained when CNT10, for which CNT is grafted on the carbon fibres for deposition time of 10 min, was used for the heating element of resistance welding. In the case of CNT deposition time of 60 min, the lowest flexural strength was obtained because of the poor impregnation of the resin into the carbon fibre due to the excess CNT on the carbon fibres.
Acknowledgement to Reviewers of Journal of Functional Biomaterials in 2018
Authors:   Journal of Functional Biomaterials Editorial Office
Published: January 2019

Rigorous peer-review is the corner-stone of high-quality academic publishing [...]
FPGA-Based Processor Acceleration for Image Processing Applications
Authors: Siddiqui Fahad , Amiri Sam , Minhas Umar Ibrahim , Deng Tiantai , Woods Roger , Rafferty Karen , Crookes Daniel
Published: January 2019

FPGA-based embedded image processing systems offer considerable computing resources but present programming challenges when compared to software systems. The paper describes an approach based on an FPGA-based soft processor called Image Processing Processor (IPPro) which can operate up to 337 MHz on a high-end Xilinx FPGA family and gives details of the dataflow-based programming environment. The approach is demonstrated for a k-means clustering operation and a traffic sign recognition application, both of which have been prototyped on an Avnet Zedboard that has Xilinx Zynq-7000 system-on-chip (SoC). A number of parallel dataflow mapping options were explored giving a speed-up of 8 times for the k-means clustering using 16 IPPro cores, and a speed-up of 9.6 times for the morphology filter operation of the traffic sign recognition using 16 IPPro cores compared to their equivalent ARM-based software implementations. We show that for k-means clustering, the 16 IPPro cores implementation is 57, 28 and 1.7 times more power efficient (fps/W) than ARM Cortex-A7 CPU, nVIDIA GeForce GTX980 GPU and ARM Mali-T628 embedded GPU respectively.
Quality Assessment of HDR/WCG Images Using HDR Uniform Color Spaces
Authors: Rousselot Maxime , Le Meur Olivier , Cozot Rémi , Ducloux Xavier
Published: January 2019

High Dynamic Range (HDR) and Wide Color Gamut (WCG) screens are able to render brighter and darker pixels with more vivid colors than ever. To assess the quality of images and videos displayed on these screens, new quality assessment metrics adapted to this new content are required. Because most SDR metrics assume that the representation of images is perceptually uniform, we study the impact of three uniform color spaces developed specifically for HDR and WCG images, namely, I C t C p , J z a z b z and H D R - L a b on 12 SDR quality assessment metrics. Moreover, as the existing databases of images annotated with subjective scores are using a standard gamut, two new HDR databases using WCG are proposed. Results show that MS-SSIM and FSIM are among the most reliable metrics. This study also highlights the fact that the diffuse white of HDR images plays an important role when adapting SDR metrics for HDR content. Moreover, the adapted SDR metrics does not perform well to predict the impact of chrominance distortions.
Applicability of Nonlinear Wavemaker Theory
Authors: Eldrup Mads Røge , Lykke Andersen Thomas
Published: January 2019

Generation of high-quality waves is essential when making numerical or physically model tests. When using a wavemaker theory outside the validity area, spurious waves are generated. In order to investigate the validity of different wave generation methods, new model test results are presented where linear and nonlinear wave generation theories are tested on regular and irregular waves. A simple modification to the second-order wavemaker theory is presented, which significantly reduces the generation of spurious waves when used outside its range of applicability. For highly nonlinear regular waves, only the ad-hoc unified wave generation based on stream function wave theory was found acceptable. For irregular waves, similar conclusions are drawn, but the modified second-order wavemaker method is more relevant. This is because the ad-hoc unified generation method for irregular waves requires the wave kinematics to be calculated by a numerical model, which might be quite time-consuming. Finally, a table is presented with the range of applicability for each wavemaker method for regular and irregular waves.
Preparation and Characterization of Nanoporous Activated Carbon Derived from Prawn Shell and Its Application for Removal of Heavy Metal Ions
Authors: Guo Jian , Song Yaqin , Ji Xiaoyang , Ji Lili , Cai Lu , Wang Yaning , Zhang Hailong , Song Wendong
Published: January 2019

The aim of this study was to optimize the adsorption performance of activated carbon (AC), derived from the shell of Penaeus vannamei prawns, on heavy metal ions. Inexpensive, non-toxic, and renewable prawn shells were subjected to carbonization and, subsequently, KOH-activation to produce nanoporous K-Ac. Carbonized prawn shells (CPS) and nanoporous KOH-activated carbon (K-Ac) from prawn shells were prepared and characterized by FTIR, XRD, BET, SEM, and TEM. The results showed that as-produced K-Ac samples were a porous material with microporous and mesoporous structures and had a high specific surface area of 3160 m2/g, average pore size of about 10 nm, and large pore volume of 2.38 m3/g. Furthermore, batches of K-Ac samples were employed for testing the adsorption behavior of Cd2+ in solution. The effects of pH value, initial concentration, and adsorption time on Cd2+ were systematically investigated. Kinetics and isotherm model analysis of the adsorption of Cd2+ on K-Ac showed that experimental data were not only consistent with the Langmuir adsorption isotherm, but also well-described by the quasi-first-order model. Finally, the adsorption behaviors of as-prepared K-Ac were also tested in a ternary mixture of heavy metal ions Cu2+, Cr6+, and Cd2+, and the total adsorption amount of 560 mg/g was obtained.
Strengthening from Cu Addition in 0.2C-(1-2)Mn Steels during Tempering
Authors: Dlouhy Jaromir , Podany Pavel , Dzugan Jan
Published: January 2019

The strengthening effects of Cu and Mn were studied in steels, which contained 0.2% C and were micro-alloyed with B and Ti. The experimental steels were austenitized and quenched in order to take Mn and Cu into solid solution. The subsequent tempering of martensitic structures resulted in higher strengths in the materials alloyed with Cu than in the steel without Cu addition. Tensile testing and metallographic analyses were performed. The kinetics and magnitude of precipitation strengthening were measured for different tempering temperatures and times. Presumed synergistic effects between Cu precipitation strengthening and higher levels of Mn were observed.
The Effects of Silica on the Properties of Vitreous Enamels
Authors: Reis Signo T. , Koenigstein Mike , Fan Liang , Chen Genda , Pavić Luka , Moguš-Milanković Andrea
Published: January 2019

Ground coat enamels for low carbon steel that contain silica as a mill addition have been developed to study the changes of their properties. Acid-resistant commercial enamel where silica addition was varied from 0 to 10.0 wt % was used for this investigation. The effects of the addition on the corrosion resistance, thermal properties, electrical properties, and mechanical adherence of the enamel to low carbon steel were studied. The corrosion resistance of the steel enameled coupons was tested using a salt spray (fog) apparatus for time periods reaching 168 h at room temperature. It was found that, although the density was not affected, the adherence decreased with an increase in silica content. As expected, the silica addition decreased the coefficient of thermal expansion, which is directly related to the increasing stress between the glass and steel in accordance with the adherence results. A mill addition of 7.5 wt% of silica to the samples was sufficient to obtain adequate enamel adherence and good corrosion resistance. Furthermore, the addition of silica influenced the electrical conductivity and dielectric permittivity measurements at room temperature and the conductivity measured in a wide frequency range (1 Hz–1 MHz). The dielectric permittivity measured at 1 MHz showed decrease after the addition of up to 7.5 wt% of silica.
Highly Sensitive Formaldehyde Detection Using Well-Aligned Zinc Oxide Nanosheets Synthesized by Chemical Bath Deposition Technique
Authors: Kim Eun-Bi , Seo Hyung-Kee
Published: January 2019

Detection of formaldehyde is very important in terms of life protection, as it can cause serious injury to eyes, skin, mouth and gastrointestinal function if indirectly inhaled. Researchers are therefore putting effort into developing novel and sensitive devices. In this work, we have fabricated an electro-chemical sensor in the form of a field effect transistor (FET) to detect formaldehyde over a wide range (10 nM to 1 mM). For this, ZnO nanosheets (NS) were first synthesized by hydrothermal method with in-situ deposition on cleaned SiO2/Si (100) substrate. The synthesized materials were characterized for morphology and purity and surface area (31.718 m2/g). The developed device was tested for formaldehyde detection at room temperature that resulted in a linear (96%) and reproducible response with concentration, sensitivity value of 0.27 mA/M/cm2 with an error of ±2% and limit of detection (LOD) as 210 nM.
Materials for the Spine: Anatomy, Problems, and Solutions
Authors: Frost Brody A. , Camarero-Espinosa Sandra , Foster E. Johan
Published: January 2019

Disc degeneration affects 12% to 35% of a given population, based on genetics, age, gender, and other environmental factors, and usually occurs in the lumbar spine due to heavier loads and more strenuous motions. Degeneration of the extracellular matrix (ECM) within reduces mechanical integrity, shock absorption, and swelling capabilities of the intervertebral disc. When severe enough, the disc can bulge and eventually herniate, leading to pressure build up on the spinal cord. This can cause immense lower back pain in individuals, leading to total medical costs exceeding $100 billion. Current treatment options include both invasive and noninvasive methods, with spinal fusion surgery and total disc replacement (TDR) being the most common invasive procedures. Although these treatments cause pain relief for the majority of patients, multiple challenges arise for each. Therefore, newer tissue engineering methods are being researched to solve the ever-growing problem. This review spans the anatomy of the spine, with an emphasis on the functions and biological aspects of the intervertebral discs, as well as the problems, associated solutions, and future research in the field.
Synergistic Effect on the Thermomechanical and Electrical Properties of Epoxy Composites with the Enhancement of Carbon Nanotubes and Graphene Nano Platelets
Authors: Jen Yi-Ming , Huang Jui-Cheng
Published: January 2019

The synergetic effect of adding multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) on the thermomechanical properties and electric resistance of epoxy polymers were experimentally analyzed in this study. The total content of two employed carbon fillers were kept constant at 0.4 wt %, and seven filler ratios between two fillers (MWCNTs:GNPs), i.e., 10:0, 1:9, 3:7, 5:5, 7:3, 9:1, and 0:10, were considered in the experimental program to investigate the influences of employed nano-filler ratios on the viscoelastic and electrical properties of the studied nanocomposites. The thermomechanical properties and the sheet resistance of the nanocomposites were analyzed using a dynamic mechanical analyzer and four-point probe, respectively. Moreover, the thermogravimetric analyzer was utilized to measure the pyrolysis temperature of the nanocomposites. Experimental results show that the synergistic effect of adding two nano-fillers were clear for the improvement of the storage moduli, glass transition temperatures, and electric conductivity. Oppositely, the employment of two fillers has a slight effect on the pyrolysis temperatures of the studied nanocomposites. The composites with the MWCNT:GNP ratio of 1:9 display the most apparent enhancement of the thermomechanical properties. The improvement results from the uniform distribution and the high aspect ratio of GNPs. The addition of a small amount of MWCNTs provides more linkage in the matrix. Moreover, the specimens with the MWCNT:GNP ratio of 1:9 shows remarkable electrical properties, which result from the large contact surface areas of GNPs with each other. The employment of few MWCNTs plays an important bridging role between the layered GNPs.
Multiscale 3D Curvature Analysis of Processed Surface Textures of Aluminum Alloy 6061 T6
Authors: Bartkowiak Tomasz , Brown Christopher A.
Published: January 2019

The objectives of this paper are to demonstrate the viability, and to validate, in part, a multiscale method for calculating curvature tensors on measured surface topographies with two different methods of specifying the scale. The curvature tensors are calculated as functions of scale, i.e., size, and position from a regular, orthogonal array of measured heights. Multiscale characterization of curvature is important because, like slope and area, it changes with the scale of observation, or calculation, on irregular surfaces. Curvatures can be indicative of the topographically dependent behavior of a surface and, in turn, curvatures are influenced by the processing and use of the surface. Curvatures of surface topographies have not been well- characterized yet. Curvature has been used for calculations in contact mechanics and for the evaluation of cutting edges. Manufactured surfaces are studied for further validation of the calculation method because they provide certain expectations for curvatures, which depend on scale and the degree of curvature. To study a range of curvatures on manufactured surfaces, square edges are machined and honed, then rounded progressively by mass finishing; additionally, a set of surfaces was made by turning with different feeds. Topographic measurements are made with a scanning laser confocal microscope. The calculations use vectors, normal to the measured surface, which are calculated first, then the eigenvalue problem is solved for the curvature tensor. Plots of principal curvatures as a function of position and scale are presented. Statistical analyses show expected interactions between curvature and these manufacturing processes.
Global Dynamics of Leslie-Gower Competitive Systems in the Plane
Authors: Kulenović Mustafa R. S. , McArdle David T.
Published: January 2019

Global dynamic results are obtained for families of competitive systems of difference equations of the form x n + 1 = b 1 x n α 1 + x n + c 1 y n , y n + 1 = b 2 y n α 2 + c 2 x n + y n n = 0 , 1 , … , where the parameters b 1 , b 2 are positive numbers, and α 1 , α 2 , c 1 , and c 2 and the initial conditions x 0 and y 0 are arbitrary non-negative numbers, when one or both of α i , i = 1 , 2 equalls 0. We assume that the denominators of both equations are always positive. We will show that the presence of more parameters will create more dynamic scenarios.
A Refinement of Schwarz–Pick Lemma for Higher Derivatives
Authors: Kwon Ern Gun , Lee Jinkee , Kwon Gun , Kim Mi Hui
Published: January 2019

In this paper, a Schwarz–Pick estimate of a holomorphic self map f of the unit disc D having the expansion f ( w ) = c 0 + c n ( w − z ) n + … in a neighborhood of some z in D is given. This result is a refinement of the Schwarz–Pick lemma, which improves a previous result of Shinji Yamashita.
The Structure of Moduloid on a Nexus
Authors: Bolourian Masoud , Kamrani Reza , Hasankhani Abbas
Published: January 2019

In this paper, the notion of moduloid on a nexus is introduced. Moreover, the concept of submoduloid is defined and some different submoduloids are introdused. Also, several interesting facts about submoduloids are proved. Finally, a homomorphism between two moduloids is defined and some related results are investigated.
Fragment-Based Structural Optimization of a Natural Product Itampolin A as a p38α Inhibitor for Lung Cancer
Authors: Liang Jing-wei , Wang Ming-yang , Wang Shan , Li Xin-yang , Meng Fan-hao
Published: January 2019

Marine animals and plants provide abundant secondary metabolites with antitumor activity. Itampolin A is a brominated natural tyrosine secondary metabolite that is isolated from the sponge Iotrochota purpurea. Recently, we have achieved the first total synthesis of this brominated tyrosine secondary metabolite, which was found to be a potent p38α inhibitor exhibiting anticancer effects. A fragment-based drug design (FBDD) was carried out to optimize itampolin A. Forty-five brominated tyrosine derivatives were synthesized with interesting biological activities. Then, a QSAR study was carried out to explore the structural determinants responsible for the activity of brominated tyrosine skeleton p38α inhibitors. The lead compound was optimized by a FBDD method, then three series of brominated tyrosine derivatives were synthesized and evaluated for their inhibitory activities against p38α and tumor cells. Compound 6o (IC50 = 0.66 μM) exhibited significant antitumor activity against non-small cell lung A549 cells (A549). This also demonstrated the feasibility of the FBDD method of structural optimization.
Management of Acute Respiratory Failure Due to Community-Acquired Pneumonia: A Systematic Review
Authors: Vanoni Nicolò Maria , Carugati Manuela , Borsa Noemi , Sotgiu Giovanni , Saderi Laura , Gori Andrea , Mantero Marco , Aliberti Stefano , Blasi Francesco
Published: January 2019

Community-acquired pneumonia (CAP) is a leading cause of mortality worldwide. CAP mortality is driven by the development of sepsis and acute respiratory failure (ARF). We performed a systematic review of the available English literature published in the period 1 January 1997 to 31 August 2017 and focused on ARF in CAP. The database searches identified 189 articles—of these, only 29 were retained for data extraction. Of these 29 articles, 12 addressed ARF in CAP without discussing its ventilatory management, while 17 evaluated the ventilatory management of ARF in CAP. In the studies assessing the ventilatory management, the specific treatments addressed were: high-flow nasal cannula (HFNC) (n = 1), continuous positive airway pressure (n = 2), non-invasive ventilation (n = 9), and invasive mechanical ventilation (n = 5). When analyzed, non-invasive ventilation (NIV) success rates ranged from 20% to 76% and they strongly predicted survival, while NIV failure led to an increased risk of adverse outcome. In conclusion, ARF in CAP patients may require both ventilatory and non-ventilatory management. Further research is needed to better evaluate the use of NIV and HFNC in those patients. Alongside the prompt administration of antimicrobials, the potential use of steroids and the implementation of severity scores should also be considered.
Acoustophoretic Control of Microparticle Transport Using Dual-Wavelength Surface Acoustic Wave Devices
Authors: Hsu Jin-Chen , Hsu Chih-Hsun , Huang Yeo-Wei
Published: January 2019

We present a numerical and experimental study of acoustophoretic manipulation in a microfluidic channel using dual-wavelength standing surface acoustic waves (SSAWs) to transport microparticles into different outlets. The SSAW fields were excited by interdigital transducers (IDTs) composed of two different pitches connected in parallel and series on a lithium niobate substrate such that it yielded spatially superimposed and separated dual-wavelength SSAWs, respectively. SSAWs of a singltablee target wavelength can be efficiently excited by giving an RF voltage of frequency determined by the ratio of the velocity of the SAW to the target IDT pitch (i.e., f = cSAW/p). However, the two-pitch IDTs with similar pitches excite, less efficiently, non-target SSAWs with the wavelength associated with the non-target pitch in addition to target SSAWs by giving the target single-frequency RF voltage. As a result, dual-wavelength SSAWs can be formed. Simulated results revealed variations of acoustic pressure fields induced by the dual-wavelength SSAWs and corresponding influences on the particle motion. The acoustic radiation force in the acoustic pressure field was calculated to pinpoint zero-force positions and simulate particle motion trajectories. Then, dual-wavelength SSAW acoustofluidic devices were fabricated in accordance with the simulation results to experimentally demonstrate switching of SSAW fields as a means of transporting particles. The effects of non-target SSAWs on pre-actuating particles were predicted and observed. The study provides the design considerations needed for the fabrication of acoustofluidic devices with IDT-excited multi-wavelength SSAWs for acoustophoresis of microparticles.
Basin Evolution and Massive Sulfide Deposition at Rammelsberg (Germany): Updating the Subsidence Analysis
Authors: Moreno Carmen , González Felipe , Sáez Reinaldo
Published: January 2019

The Rammelsberg sulfide deposit is classically considered as a SEDEX-type deposit. The origin of SEDEX-type massive sulfides links with the evolution of their hosting basins. They frequently constitute the source for the metal-enriched basinal brines transported afterwards as mineralizing hydrothermal fluids. This study revisits previous data concerning the analysis of the basin that hosts the Rammelsberg deposit, the Goslar basin, updating its subsidence analysis and providing new tectonic and total subsidence curves from two different paleogeographic locations: the depocenter and the basin margin. The basin evolution is defined by five stages depicting different subsidence intensity and mechanisms for each of these locations. The stratigraphic position of Rammelsberg coincides with a drastic change in the basin evolution. A rapid tectonic subsidence event is proposed as a trigger mechanism for hydrothermal activity. The paleogeographic location and the relation between supply of mineralizing fluids and sedimentation rate were critical for the concentration or dissemination of sulfides.
Synthesis, Anticancer Activity, and Apoptosis Induction of Novel 3,6-Diazaphenothiazines
Authors: Morak-Młodawska Beata , Pluta Krystian , Latocha Małgorzata , Jeleń Małgorzata , Kuśmierz Dariusz
Published: January 2019

New 10-substituted derivatives of 3,6-diazaphenothiazine, containing the triple bond linker terminated with tertiary cyclic and acyclic amine groups, were synthesized and screened for their anticancer action. The compounds exhibited varied anticancer activities against human glioblastoma SNB-19, melanoma C-32, and breast cancer MDA-MB231 cell lines, depending on the nature of the substituents. The most active 3,6-diazaphenothiazine, 4, was the derivative with the N,N-diethylamino-2-butynyl substituent against glioblastoma SNB-19, and was ten times more potent than cisplatin. For this compound, the expression of H3, TP53, CDKN1A, BCL-2, and BAX genes was detected by the RT-qPCR method. The gene expression ratio BAX/BCL-2 indicated the induction of mitochondrial apoptosis in cancer cell lines. The transformation of the propynyl substituent into amino-2-butynyl can be a method applicable to the search for more anticancer-active azaphenothiazines.
Potent Antitrypanosomal Activities of 3-Aminosteroids against African Trypanosomes: Investigation of Cellular Effects and of Cross-Resistance with Existing Drugs
Authors: Nnadi Charles O. , Ebiloma Godwin U. , Black Jennifer A. , Nwodo Ngozi J. , Lemgruber Leandro , Schmidt Thomas J. , de Koning Harry P.
Published: January 2019

Treatment of animal African trypanosomiasis (AAT) requires urgent need for safe, potent and affordable drugs and this has necessitated this study. We investigated the trypanocidal activities and mode of action of selected 3-aminosteroids against Trypanosoma brucei brucei. The in vitro activity of selected compounds of this series against T. congolense (Savannah-type, IL3000), T. b. brucei (bloodstream trypomastigote, Lister strain 427 wild-type (427WT)) and various multi-drug resistant cell lines was assessed using a resazurin-based cell viability assay. Studies on mode of antitrypanosomal activity of some selected 3-aminosteroids against Tbb 427WT were also carried out. The tested compounds mostly showed moderate-to-low in vitro activities and low selectivity to mammalian cells. Interestingly, a certain aminosteroid, holarrhetine (10, IC50 = 0.045 ± 0.03 µM), was 2 times more potent against T. congolense than the standard veterinary drug, diminazene aceturate, and 10 times more potent than the control trypanocide, pentamidine, and displayed an excellent in vitro selectivity index of 2130 over L6 myoblasts. All multi-drug resistant strains of T. b. brucei tested were not significantly cross-resistant with the purified compounds. The growth pattern of Tbb 427WT on long and limited exposure time revealed gradual but irrecoverable growth arrest at ≥ IC50 concentrations of 3-aminosteroids. Trypanocidal action was not associated with membrane permeabilization of trypanosome cells but instead with mitochondrial membrane depolarization, reduced adenosine triphosphate (ATP) levels and G2/M cell cycle arrest which appear to be the result of mitochondrial accumulation of the aminosteroids. These findings provided insights for further development of this new and promising class of trypanocide against African trypanosomes.
Clofibrate Treatment Decreases Inflammation and Reverses Myocardial Infarction-Induced Remodelation in a Rodent Experimental Model
Authors: Ibarra-Lara Luz , Sánchez-Aguilar María , Soria-Castro Elizabeth , Vargas-Barrón Jesús , Roldán Francisco J. , Pavón Natalia , Torres-Narváez Juan C. , Cervantes-Pérez Luz G. , Pastelín-Hernández Gustavo , Sánchez-Mendoza Alicia
Published: January 2019

Myocardial infarction (MI) initiates an inflammatory response that promotes both beneficial and deleterious effects. The early response helps the myocardium to remove damaged tissue; however, a prolonged later response brings cardiac remodeling characterized by functional, metabolic, and structural pathological changes. Current pharmacological treatments have failed to reverse ischemic-induced cardiac damage. Therefore, our aim was to study if clofibrate treatment was capable of decreasing inflammation and apoptosis, and reverse ventricular remodeling and MI-induced functional damage. Male Wistar rats were assigned to (1) Sham coronary artery ligation (Sham) or (2) Coronary artery ligation (MI). Seven days post-MI, animals were further divided to receive vehicle (V) or clofibrate (100 mg/kg, C) for 7 days. The expression of IL-6, TNF-α, and inflammatory related molecules ICAM-1, VCAM-1, MMP-2 and -9, nuclear NF-kB, and iNOS, were elevated in MI-V. These inflammatory biomarkers decreased in MI-C. Also, apoptotic proteins (Bax and pBad) were elevated in MI-V, while clofibrate augmented anti-apoptotic proteins (Bcl-2 and 14-3-3ε). Clofibrate also protected MI-induced changes in ultra-structure. The ex vivo evaluation of myocardial functioning showed that left ventricular pressure and mechanical work decreased in infarcted rats; clofibrate treatment raised those parameters to control values. Echocardiogram showed that clofibrate partially reduced LV dilation. In conclusion, clofibrate decreases cardiac remodeling, decreases inflammatory molecules, and partly preserves myocardial diameters.
Cajanolactone A from Cajanus cajan Promoted Osteoblast Differentiation in Human Bone Marrow Mesenchymal Stem Cells via Stimulating Wnt/LRP5/β-Catenin Signaling
Authors: Liu Shan , Luo Zhuo-Hui , Ji Gui-Mei , Guo Wei , Cai Jia-Zhong , Fu Lin-Chun , Zhou Juan , Hu Ying-Jie , Shen Xiao-Ling
Published: January 2019

Cajanolactone A (CLA) is a stilbenoid discovered by us from Cajanus cajan (L.) Millsp. In our study, CLA was found to promote osteoblast differentiation in human bone marrow mesenchymal stem cells (hBMSCs), as judged by increased cellular alkaline phosphatase activity and extracellular calcium deposits, and elevated protein expression of Runx2, collagen-1, bone morphogenetic protein-2, and osteopontin. Mechanistic studies revealed that hBMSCs undergoing osteoblast differentiation expressed upregulated mRNA levels of Wnt3a, Wnt10b, LRP5/6, Frizzled 4, β-catenin, Runx2, and Osterix from the early stage of differentiation, indicating the role of activated Wnt/β-catenin signaling pathway in osteoblast differentiation. Addition of CLA to the differentiation medium further increased the mRNA level of Wnt3a, Wnt10b, Frizzled 4, LRP5, and β-catenin, inferring that CLA worked by stimulating Wnt/LRP5/β-catenin signaling. Wnt inhibitor dickkopf-1 antagonized CLA-promoted osteoblastogenesis, indicating that CLA did not target the downstream of canonical Wnt signaling pathway. Treatment with CLA caused no changes in mRNA expression level, as well as protein secretion of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL), indicating that CLA did not affect the OPG/RANKL axis. Our results showed that CLA, which promoted osteoblast differentiation in hBMSCs, through activating Wnt/LRP5/β-catenin signaling transduction, is a promising anti-osteoporotic drug candidate.
First-Principles Study of the Reaction between Fluorinated Graphene and Ethylenediamine
Authors: Tian Jin , Chen Yuhong , Wang Jing , Liu Tingting , Zhang Meiling , Zhang Cairong
Published: January 2019

The reaction process between gauche- and trans-structure ethylenediamine (EDA) and fluorinated graphene (CF) was studied based on density functional theory (DFT). Firstly, the reaction between the most stable gauche-structure EDA and CF was discussed. Some of the reaction results were verified in experiment, but the overall reaction energy barrier was higher. Then, the reaction between the trans-structured EDA and CF was simulated, which concluded that CF is reduced in the main reaction channel and HF is generated at the same time. In this reaction process, the reaction energy barrier is as low as 0.81 eV, which indicates that the reaction may occur spontaneously under natural conditions The Mulliken charge population analysis and the calculation of bond energy prove that the NH bond is more stable than CH and that the H atoms in the CH2 of trans-structure EDA more easily react with CF.
Microwave-Assisted Dehydrogenative Cross Coupling Reactions in γ-valerolactone with a Reusable Pd/β-cyclodextrin Crosslinked Catalyst
Authors: Tabasso Silvia , Calcio Gaudino Emanuela , Acciardo Elisa , Manzoli Maela , Giacomino Agnese , Cravotto Giancarlo
Published: January 2019

Transition-metal mediated C–H bond activation and functionalization is one of the most straightforward and powerful tools in modern organic synthetic chemistry. Oxidative C–H/C–H coupling reactions between two (hetero)arenes under heterogeneous catalysis may be a valuable means for the production of a plethora of bi(hetero)aryls, and one that adheres to the increasing demand for atom-economic and sustainable chemistry. We have therefore developed a reusable heterogeneous catalytic system, which is based on Pd cross-linked β-cyclodextrin, to perform an efficient microwave-assisted oxidative C–H/C–H cross coupling process between benzothiazoles and methyl thiophene in the presence of green solvents.
Improving of the Photovoltaic Characteristics of Dye-Sensitized Solar Cells Using a Photoelectrode with Electrospun Porous TiO2 Nanofibers
Authors: Jo Min Su , Cho Jung Sang , Wang Xuan Liang , Jin En Mei , Jeong Sang Mun , Kang Dong-Won
Published: January 2019

Porous TiO2 nanofibers (PTFs) and dense TiO2 nanofibers (DTFs) were prepared using simple electrospinning for application in dye-sensitized solar cells (DSSCs). TiO2 nanoparticles (TNPs) were prepared using a hydrothermal reaction. The as-prepared PTFs and DTFs (with a fiber diameter of around 200 nm) were mixed with TNPs such as TNP-PTF and TNP-DTF nanocomposites used in photoelectrode materials or were coated as light scattering layers on the photoelectrodes to improve the charge transfer ability and light harvesting effect of the DSSCs. The as-prepared TNPs showed a pure anatase phase, while the PTFs and DTFs showed both the anatase and rutile phases. The TNP-PTF composite (TNP:PTF = 9:1 wt.%) exhibited an enhanced short circuit photocurrent density (Jsc) of 14.95 ± 1.03 mA cm−2 and a photoelectric conversion efficiency (PCE, η) of 5.4 ± 0.17% because of the improved charge transport and accessibility for the electrolyte ions. In addition, the TNP/PTF photoelectrode showed excellent light absorption in the visible region because of the mountainous nature of light induced by the PTF light scattering layer. The TNP/PTF photoelectrode showed the highest Jsc (16.96 ± 0.79 mA cm−2), η (5.9 ± 0.13%), and open circuit voltage (Voc, 0.66 ± 0.02 V).
Neurotoxicity of Nanomaterials: An Up-to-Date Overview
Authors: Teleanu Daniel Mihai , Chircov Cristina , Grumezescu Alexandru Mihai , Teleanu Raluca Ioana
Published: January 2019

The field of nanotechnology, through which nanomaterials are designed, characterized, produced, and applied, is rapidly emerging in various fields, including energy, electronics, food and agriculture, environmental science, cosmetics, and medicine. The most common biomedical applications of nanomaterials involve drug delivery, bioimaging, and gene and cancer therapy. Since they possess unique properties which are different than bulk materials, toxic effects and long-term impacts on organisms are not completely known. Therefore, the purpose of this review is to emphasize the main neurotoxic effects induced by nanoparticles, liposomes, dendrimers, carbon nanotubes, and quantum dots, as well as the key neurotoxicology assays to evaluate them.
Promoting Recycling of Mixed Waste Polymers in Wood-Polymer Composites Using Compatibilizers
Authors: Martikka Ossi , Kärki Timo
Published: January 2019

Millions of tons of plastics are produced and consumed annually and should be recycled in a sustainable way. The effects of different compatibilizers on the properties of wood-mixed waste polymer composites are studied to promote recycling of plastics and to determine the potential of using waste plastics in composites. The effect of different addition levels and blending of compatibilizers is examined as well. The studied properties are microstructure, tensile and flexural properties, impact strength, and water absorption and thickness swelling in immersion. The results show that the addition of the selected compatibilizers improved the properties of wood-mixed waste polymer composites remarkably—all the studied mechanical properties and moisture resistance were improved by 50% or more. The effects depend strongly on the level of addition and the compatibilizer used. Findings show that compatibilization provides a feasible means to recycle waste plastics as feedstock for wood–plastic composites.