bluuebunny/crossref_metadata_2025 huggingface dataset:
A Non-Invasive Procedure for Estimating the Exponential Model Parameters of Bypass Diodes in Photovoltaic Modules
Authors: Vélez-Sánchez Jeisson , Bastidas-Rodríguez Juan , Ramos-Paja Carlos , González Montoya Daniel , Trejos-Grisales Luz
Published: January 2019

Bypass diodes (BDs) present in photovoltaic (PV) modules are represented by the exponential model, which requires two parameters: the inverse-saturation current ( I s a t , d b ) and the ideality factor ( η d b ). However, it is difficult to estimate those parameters since the terminals of the BDs are not isolated, hence there is only access to the series connection of the module BDs. This problem must be addressed since inaccurate BDs parameters could produce errors in the reproduction of the current-voltage (I-V) curves of commercial PV modules, which lead to wrong predictions of the power production. This paper proposes a non-invasive procedure to estimate I s a t , d b and η d b of the bypass diodes present in a PV module using two experimental I-V curves. One I-V curve is measured completely covering the submodule of the module whose BD will be parameterized; while the other I-V curve is measured without any shadow on the module. From those curves, the I-V curve of the BD is estimated and I s a t , d b and η d b are calculated by solving a system of two nonlinear equations. The proposed procedure is validated through simulations and experimental results considering a commercial PV module formed by three submodules, where the estimation errors in the reproduction of the BD I-V curve are less than 1% in the simulations and less than 10% in the experiments.
Well-Dispersed ZnFe2O4 Nanoparticles onto Graphene as Superior Anode Materials for Lithium Ion Batteries
Authors: Park Yiseul , Oh Misol , Kim Jae Hyun
Published: January 2019

We prepared well-dispersed ZnFe2O4 (ZFO) nanoparticles on a graphene sheet by a facile one-step hydrothermal method using glucose as a novel linker agent and low-cost graphene flake. It was found that the glucose linkage on graphene not only prevented the aggregation of ZFO particles, but also induced the exfoliation of graphene flakes. The addition of glucose during the synthesis made surface linkages on the graphene surface, and it reacted with ZFO precursors, resulting in the well-dispersed ZFO nanoparticles/graphene composite. Furthermore, the size distribution of the resultant composite particles was also shifted to the smaller particle size compared to the composite prepared without glucose. The newly prepared ZFO/graphene composite provided a higher lithium storage capability and cycle performance compared to the ZFO/graphene sample which was prepared without glucose. The good dispersion of ZFO nanoparticles on graphene and the small particle size of the composite led to markedly improved electrochemical performance. Its reversible discharge capacity was 766 mAh g−1 at 1 A g−1, and it also maintained as 469 mAh g−1 at 6 A g−1.
Coordinated Dialogue between UHRF1 and DNMT1 to Ensure Faithful Inheritance of Methylated DNA Patterns
Authors: Bronner Christian , Alhosin Mahmoud , Hamiche Ali , Mousli Marc
Published: January 2019

DNA methylation, catalyzed by DNA methyltransferases (DNMTs), is an epigenetic mark that needs to be faithfully replicated during mitosis in order to maintain cell phenotype during successive cell divisions. This epigenetic mark is located on the 5′-carbon of the cytosine mainly within cytosine–phosphate–guanine (CpG) dinucleotides. DNA methylation is asymmetrically positioned on both DNA strands, temporarily generating a hemi-methylated state after DNA replication. Hemi-methylation is a particular status of DNA that is recognized by ubiquitin-like containing plant homeodomain (PHD) and really interesting new gene (RING) finger domains 1 (UHRF1) through its SET- (Su(var)3-9, Enhancer-of-zeste and Trithorax) and RING-associated (SRA) domain. This interaction is considered to be involved in the recruitment of DNMT1 to chromatin in order to methylate the adequate cytosine on the newly synthetized DNA strand. The UHRF1/DNMT1 tandem plays a pivotal role in the inheritance of DNA methylation patterns, but the fine-tuning mechanism remains a mystery. Indeed, because DNMT1 experiences difficulties in finding the cytosine to be methylated, it requires the help of a guide, i.e., of UHRF1, which exhibits higher affinity for hemi-methylated DNA vs. non-methylated DNA. Two models of the UHRF1/DNMT1 dialogue were suggested to explain how DNMT1 is recruited to chromatin: (i) an indirect communication via histone H3 ubiquitination, and (ii) a direct interaction of UHRF1 with DNMT1. In the present review, these two models are discussed, and we try to show that they are compatible with each other.
A Selective Review of Multi-Level Omics Data Integration Using Variable Selection
Authors: Wu Cen , Zhou Fei , Ren Jie , Li Xiaoxi , Jiang Yu , Ma Shuangge
Published: January 2019

High-throughput technologies have been used to generate a large amount of omics data. In the past, single-level analysis has been extensively conducted where the omics measurements at different levels, including mRNA, microRNA, CNV and DNA methylation, are analyzed separately. As the molecular complexity of disease etiology exists at all different levels, integrative analysis offers an effective way to borrow strength across multi-level omics data and can be more powerful than single level analysis. In this article, we focus on reviewing existing multi-omics integration studies by paying special attention to variable selection methods. We first summarize published reviews on integrating multi-level omics data. Next, after a brief overview on variable selection methods, we review existing supervised, semi-supervised and unsupervised integrative analyses within parallel and hierarchical integration studies, respectively. The strength and limitations of the methods are discussed in detail. No existing integration method can dominate the rest. The computation aspects are also investigated. The review concludes with possible limitations and future directions for multi-level omics data integration.
Integrating Landscape Metrics and Hydrologic Modeling to Assess the Impact of Natural Disturbances on Ecohydrological Processes in the Chenyulan Watershed, Taiwan
Authors: Chiang Li-Chi , Chuang Yi-Ting , Han Chin-Chuan
Published: January 2019

The Chenyulan watershed, located in the central mountain area of Taiwan, has been suffering from earthquakes, typhoons, and heavy rainfalls in recent decades. These sequential natural disturbances have a cumulative impact on the watershed, leading to more fragile and fragmented land cover and loss of capacity of soil water conservation. In this study, the Soil and Water Assessment Tool (SWAT) and a landscape metrics tool (FRAGSTATS) were used to assess the direct impact (e.g., by annual rainfall) and indirect impact (e.g., by landscape configuration and composition) of natural disturbances on the ecohydrological processes of the Chenyulan watershed. Six SPOT satellite images from 2008 to 2013 were analyzed by using the nearest feature line embedding (NFLE) approach and reclassified into six land cover types: forest, cultivated land, grassland, river, landslide, and built-up. Forest was found to have the largest patch size, indicating that it is more resilient to disturbances, while agricultural land tended to expand from the river side toward the hill. Two land cover change scenarios were compared in the SWAT model. The results showed that there was no significant difference in simulated streamflow during 2004–2015 and sediment loading during 2004–2009; however, the model performed better for sediment loading during 2010–2015 with dynamic land cover change (coefficient of determination (R2) = 0.66, Nash-Sutcliffe efficiency coefficient (NSE) = 0.62, percent bias (PBIAS) = 10.5%, root mean square error observation standard deviation ratio (RSR) = 0.62) than with constant land cover (R2 = 0.61, NSE = 0.54, PBIAS = −17.3%, RSR = 0.68), indicating that long-term land cover change should be considered in hydrologic modeling. Changes in landslides during 2008–2013 were found to significantly affect ecohydrological processes, especially after 2011. In general, annual precipitation plays a dominant role, and landscape composition had by far the strongest influence on water yield and sediment yield compared to landscape configuration. The results can be useful for understanding the effects of land cover change on ecohydrological processes in the Chenyulan watershed and the potential impact of ecohydrological changes on the environment and public health.
Toxic Effect of Acute Cadmium and Lead Exposure in Rat Blood, Liver, and Kidney
Authors: Andjelkovic Milena , Buha Djordjevic Aleksandra , Antonijevic Evica , Antonijevic Biljana , Stanic Momcilo , Kotur-Stevuljevic Jelena , Spasojevic-Kalimanovska Vesna , Jovanovic Milos , Boricic Novica , Wallace David , Bulat Zorica
Published: January 2019

Background: Cadmium and lead are widespread and non-biodegradable pollutants of great concern to human health. In real life scenarios, we are exposed to mixtures of chemicals rather than single chemicals, and it is therefore of paramount importance to assess their toxicity. In this study, we investigated the toxicity of Cd and Pb alone and as a mixture in an animal model of acute exposure. Methods: Experimental groups received a single treatment of aqueous solution of Cd-chloride (15 and 30 mg/kg body weight (b.w.) and Pb-acetate (150 mg/kg b.w.), while the mixture group received 15 mg Cd/kg b.w. and 150 mg Pb/kg b.w. Toxic effects of individual metals and their mixture were investigated on hematological and biochemical parameters, and the redox status in the plasma, liver, and kidneys of treated Wistar rats. Results: Tissue-specific changes were recorded in various parameters of oxidative damage, while the accumulation of metals in tissues accompanied the disturbances of both hematological and biochemical parameters. It was observed that the level of toxic metals in tissues had a different distribution pattern after mixture and single exposure. Conclusions: Comprehensive observations suggest that exposure to Cd and Pb mixtures produces more pronounced effects compared to the response observed after exposure to single metal solutions. However, further research is needed to confirm toxicokinetic or toxicodynamic interactions between these two toxic metals in the organisms.
Root and Shoot Biomass Growth of Constructed Floating Wetlands Plants in Saline Environments
Authors: Sanicola Oriana , Lucke Terry , Stewart Michael , Tondera Katharina , Walker Christopher
Published: January 2019

Constructed Floating Wetlands (CFWs) are increasingly being used globally in freshwater environments such as urban lakes and ponds to remove pollutants from urban stormwater runoff. However, to date there has been limited research into the use and performance of these systems in saline environments. This study compared the root and shoot biomass growth and nutrient uptake of five different plant species, Chrysopogon zizanioides, Baumea juncea, Isolepis nodosa, Phragmites australis and Sarcocornia quinqueflora, in three different saltwater treatments over a 12-week period. The aim of the study was to identify which of the plant species may be most suitable for use in CFWs in saline environments. Plant nutrient uptake testing revealed that Phragmites australis had the greatest percentage increase (1473–2477%) of Nitrogen mass in the shoots in all treatments. Sarcocornia quinqueflora also had impressive Nitrogen mass increase in saltwater showing an increase of 966% (0.208 ± 0.134 g). This suggests that the use of Phragmites australis and Sarcocornia quinqueflora plants in CFWs installed in saline water bodies, with regular harvesting of the shoot mass, may significantly reduce Nitrogen concentrations in the water. Isolepis nodosa had the greatest percentage increase (112% or 0.018 ± 0.020 g) of Phosphorous mass in the shoots in the saltwater treatment. Baumea juncea had the greatest percentage increase (315% or 0.026 ± 0.012 g) of Phosphorous mass in the roots in the saltwater treatment. This suggests that the use of Isolepis nodosa and Baumea juncea plants in CFWs installed in saline water bodies may significantly reduce Phosphorous concentrations in the water if there was a way to harvest both the shoots above and the roots below the CFWs. The study is continuing, and it is anticipated that more information will be available on CFW plants installed in saline environments in the near future.
The Relationship between Objectively Measured and Self-Reported Sedentary Behaviours and Social Connectedness among Adolescents
Authors: Arundell Lauren , Salmon Jo , Veitch Jenny , Timperio Anna
Published: January 2019

Adolescents spend significant amounts of time engaged in various types of sedentary behaviour (SB). This study examined associations between adolescents’ objectively measured sedentary time, sitting time, specific self-reported SBs and social connectedness. Adolescents (n = 429, 15.5 years, 41% male) completed an online survey reporting time in seven SBs (TV/videos/DVDs, computer/video games, internet, homework, reading, car and bus travel; examined individually and summed for screen time and total SB), and social connectedness using the eight-item Social Connectedness Scale. A subsample (n = 353) also wore an ActiGraph GT3X+ (model GT3X+, Pensacola, FL, USA) accelerometer to measure sedentary time (<100 cpm) and n = 237 wore an activPAL (PAL Technologies Ltd., Glasgow, Scotland) inclinometer to measure sitting time. Multiple linear mixed models determined associations between each SB variable and social connectedness, adjusting for confounders. Adolescents spent on average 7.8 h/day in self-reported total SB, 4.4 h/day in screen time, 9.1 h/day in ActiGraph-measured sedentary time, and 9.5 h/day in activPAL-measured sitting time. After adjusting for age, sex and area level socioeconomic status, total SB (−0.24, 95%CI: −0.37, −0.11), screen time (−0.23, 95%CI: −0.41, −0.05) and two individual SBs (computer/video games (−1.07, 95%CI: −1.53, −0.60), homework (−0.61, 95%CI: −1.04, −0.18) were negatively associated with social connectedness. There were no associations with the objective measures. The relationships may be bi-directional; therefore, future research should involve longitudinal designs and explore other potential contributing factors.
Substituent Effects on the Radical Scavenging Activity of Isoflavonoid
Authors: Zheng Yan-Zhen , Deng Geng , Guo Rui , Chen Da-Fu , Fu Zhong-Min
Published: January 2019

Understanding the role of substituents is of great importance for the preparation of novel phenolic compounds with enhanced antioxidative properties. In this work, the antioxidative activity of isoflavonoid derivatives with different substituents placed at the C2 position was determined by density functional theory (DFT) calculations. The bond dissociation enthalpy (BDE), ionization potential (IP), and proton affinity (PA) related to hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) mechanisms were calculated. The strongest antioxidative group of isoflavonoid is not altered by the substituents. Excellent correlations were found between the BDE/IP/PA and Hammett sigma constants. Equations obtained from linear regression can be useful in the selection of suitable candidates for the synthesis of novel isoflavonoids derivatives with enhanced antioxidative properties. In the gas and benzene phases, the electron-donating substituents would enhance the antioxidative activity of isoflavonoids via weakening the BDE of 4′−OH. In water phase, they will reduce the antioxidative by strengthening the PA of 7−OH. Contrary results occur for the electron-withdrawing groups. In addition, the electronic effects of substituents on the BDE/IP/PA have also been analyzed.
Curcumin and Solid Lipid Curcumin Particles Induce Autophagy, but Inhibit Mitophagy and the PI3K-Akt/mTOR Pathway in Cultured Glioblastoma Cells
Authors: Maiti Panchanan , Scott Jason , Sengupta Dipanwita , Al-Gharaibeh Abeer , Dunbar Gary L.
Published: January 2019

Autophagy and the (PI3K-Akt/mTOR) signaling pathway play significant roles in glioblastoma multiforme (GBM) cell death and survival. Curcumin (Cur) has been reported to prevent several cancers, including GBM. However, the poor solubility and limited bioavailability of natural Cur limits its application in preventing GBM growth. Previously, we have shown the greater apoptotic and anti-carcinogenic effects of solid lipid Cur particles (SLCP) than natural Cur in cultured GBM cells. Here, we compared the autophagic responses on cultured U-87MG, GL261, F98, C6-glioma, and N2a cells after treatment with Cur or SLCP (25 µM for 24 h). Different autophagy, mitophagy, and chaperone-mediated autophagy (CMA) markers, along with the PI3K-AKkt/mTOR signaling pathway, and the number of autophagy vacuoles were investigated after treatment with Cur and or SLCP. We observed increased levels of autophagy and decreased levels of mitophagy markers, along with inhibition of the PI3K-Akt/mTOR pathway after treatments with Cur or SLCP. Cell survival markers were downregulated, and cell death markers were upregulated after these treatments. We found greater effects in the case of SCLP-treated cells in comparison to Cur. Given that fewer effects were observed on C-6 glioma and N2a cells. Our results suggest that SLCP could be a safe and effective means of therapeutically modulating autophagy in GBM cells.
Transgene-Free Genome Editing in Tomato and Potato Plants Using Agrobacterium-Mediated Delivery of a CRISPR/Cas9 Cytidine Base Editor
Authors: Veillet Florian , Perrot Laura , Chauvin Laura , Kermarrec Marie-Paule , Guyon-Debast Anouchka , Chauvin Jean-Eric , Nogué Fabien , Mazier Marianne
Published: January 2019

Genome editing tools have rapidly been adopted by plant scientists for gene function discovery and crop improvement. The current technical challenge is to efficiently induce precise and predictable targeted point mutations valuable for crop breeding purposes. Cytidine base editors (CBEs) are CRISPR/Cas9 derived tools recently developed to direct a C-to-T base conversion. Stable genomic integration of CRISPR/Cas9 components through Agrobacterium-mediated transformation is the most widely used approach in dicotyledonous plants. However, elimination of foreign DNA may be difficult to achieve, especially in vegetatively propagated plants. In this study, we targeted the acetolactate synthase (ALS) gene in tomato and potato by a CBE using Agrobacterium-mediated transformation. We successfully and efficiently edited the targeted cytidine bases, leading to chlorsulfuron-resistant plants with precise base edition efficiency up to 71% in tomato. More importantly, we produced 12.9% and 10% edited but transgene-free plants in the first generation in tomato and potato, respectively. Such an approach is expected to decrease deleterious effects due to the random integration of transgene(s) into the host genome. Our successful approach opens up new perspectives for genome engineering by the co-edition of the ALS with other gene(s), leading to transgene-free plants harboring new traits of interest.
Calcium Deregulation and Mitochondrial Bioenergetics in GDAP1-Related CMT Disease
Authors: González-Sánchez Paloma , Satrústegui Jorgina , Palau Francesc , del Arco Araceli
Published: January 2019

The pathology of Charcot-Marie-Tooth (CMT), a disease arising from mutations in different genes, has been associated with an impairment of mitochondrial dynamics and axonal biology of mitochondria. Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) cause several forms of CMT neuropathy, but the pathogenic mechanisms involved remain unclear. GDAP1 is an outer mitochondrial membrane protein highly expressed in neurons. It has been proposed to play a role in different aspects of mitochondrial physiology, including mitochondrial dynamics, oxidative stress processes, and mitochondrial transport along the axons. Disruption of the mitochondrial network in a neuroblastoma model of GDAP1-related CMT has been shown to decrease Ca2+ entry through the store-operated calcium entry (SOCE), which caused a failure in stimulation of mitochondrial respiration. In this review, we summarize the different functions proposed for GDAP1 and focus on the consequences for Ca2+ homeostasis and mitochondrial energy production linked to CMT disease caused by different GDAP1 mutations.
The Role of O-GlcNAcylation for Protection against Ischemia-Reperfusion Injury
Authors: Jensen Rebekka Vibjerg , Andreadou Ioanna , Hausenloy Derek J. , Bøtker Hans Erik
Published: January 2019

Ischemia reperfusion injury (IR injury) associated with ischemic heart disease contributes significantly to morbidity and mortality. O-linked β-N-acetylglucosamine (O-GlcNAc) is a dynamic posttranslational modification that plays an important role in numerous biological processes, both in normal cell functions and disease. O-GlcNAc increases in response to stress. This increase mediates stress tolerance and cell survival, and is protective. Increasing O-GlcNAc is protective against IR injury. Experimental cellular and animal models, and also human studies, have demonstrated that protection against IR injury by ischemic preconditioning, and the more clinically applicable remote ischemic preconditioning, is associated with increases in O-GlcNAc levels. In this review we discuss how the principal mechanisms underlying tissue protection against IR injury and the associated immediate elevation of O-GlcNAc may involve attenuation of calcium overload, attenuation of mitochondrial permeability transition pore opening, reduction of endoplasmic reticulum stress, modification of inflammatory and heat shock responses, and interference with established cardioprotective pathways. O-GlcNAcylation seems to be an inherent adaptive cytoprotective response to IR injury that is activated by mechanical conditioning strategies.
Peach Kernel Oil Downregulates Expression of Tissue Factor and Reduces Atherosclerosis in ApoE knockout Mice
Authors: Hao Erwei , Pang Guofeng , Du Zhengcai , Lai Yu-Heng , Chen Jung-Ren , Xie Jinling , Zhou Kai , Hou Xiaotao , Hsiao Chung-Der , Deng Jiagang
Published: January 2019

Atherosclerosis is the pathological process in arteries due to the plaque formation that is responsible for several diseases like heart disease, stroke and peripheral arterial disease. In this study, we performed in vitro and in vivo assays to evaluate the potential anti-atherosclerosis activity of peach kernel oil. For the in vitro assay, we incubated human umbilical vein endothelial cells (HUVEC) with tumor necrosis factor-α (TNF-α) to induce tissue factors (TF, an essential mediator of hemostasis and trigger of thrombosis) elevation. We found that TNF-α-induced TF elevation was suppressed by peach kernel oil in a dose-dependent manner at both mRNA and protein levels. Peach kernel oil can significantly improve HUVEC viability, protect the endothelial cells, which achieved the goal of prevention of thrombotic diseases. For the in vivo assay, we investigated the effect and mechanism of peach kernel oil on preventing atherosclerotic lesion formation in ApoE knockout mice. Results show that peach kernel oil could reduce total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, elevate the high-density lipoprotein cholesterol level in serum, and reduce the area of the aortic atherosclerotic lesions in high-fat diet fed ApoE knockout mice. Moreover, peach kernel oil treatment can significantly down regulate the expression of TF protein to inhibit the formation of atherosclerotic plaque. In conclusion, peach kernel oil may be a potential health food to prevent atherosclerosis in cardiovascular diseases.
The Role of Angiogenesis and Pro-Angiogenic Exosomes in Regenerative Dentistry
Authors: Zimta Alina-Andreea , Baru Oana , Badea Mandra , Buduru Smaranda Dana , Berindan-Neagoe Ioana
Published: January 2019

Dental surgeries can result in traumatic wounds that provoke major discomfort and have a high risk of infection. In recent years, density research has taken a keen interest in finding answers to this problem by looking at the latest results made in regenerative medicine and adapting them to the specificities of oral tissue. One of the undertaken directions is the study of angiogenesis as an integrative part of oral tissue regeneration. The stimulation of this process is intended to enhance the local availability of stem cells, oxygen levels, nutrient supply, and evacuation of toxic waste. For a successful stimulation of local angiogenesis, two major cellular components must be considered: the stem cells and the vascular endothelial cells. The exosomes are extracellular vesicles, which mediate the communication between two cell types. In regenerative dentistry, the analysis of exosome miRNA content taps into the extended communication between these cell types with the purpose of improving the regenerative potential of oral tissue. This review analyzes the stem cells available for the dentistry, the molecular cargo of their exosomes, and the possible implications these may have for a future therapeutic induction of angiogenesis in the oral wounds.
HDAC8 Inhibitor WK2-16 Therapeutically Targets Lipopolysaccharide-Induced Mouse Model of Neuroinflammation and Microglial Activation
Authors: Lin Fan-Li , Yen Jing-Lun , Kuo Yu-Cheng , Kang Jaw-Jou , Cheng Yu-Wen , Huang Wei-Jan , Hsiao George
Published: January 2019

Glial activation and neuroinflammatory processes play important roles in the pathogenesis of brain abscess and neurodegenerative diseases. Activated glial cells can secrete various proinflammatory cytokines and neurotoxic mediators, which contribute to the exacerbation of neuronal cell death. The inhibition of glial activation has been shown to alleviate neurodegenerative conditions. The present study was to investigate the specific HDAC8 inhibitor WK2-16, especially its effects on the neuroinflammatory responses through glial inactivation. WK2-16 significantly reduced the gelatinolytic activity of MMP-9, and expression of COX-2/iNOS proteins in striatal lipopolysaccharide (LPS)-induced neuroinflammation in C57BL/6 mice. The treatment of WK2-16 markedly improved neurobehavioral deficits. Immunofluorescent staining revealed that WK2-16 reduced LPS-stimulated astrogliosis and microglial activation in situ. Consistently, cellular studies revealed that WK2-16 significantly suppressed LPS-induced mouse microglia BV-2 cell proliferation. WK2-16 was proven to concentration-dependently induce the levels of acetylated SMC3 in microglial BV-2 cells. It also reduced the expression of COX-2/iNOS proteins and TNF-α production in LPS-activated microglial BV-2 cells. The signaling studies demonstrated that WK2-16 markedly inhibited LPS-activated STAT-1/-3 and Akt activation, but not NF-κB or MAPK signaling. In summary, the HDAC8 inhibitor WK2-16 exhibited neuroprotective effects through its anti-neuroinflammation and glial inactivation properties, especially in microglia in vitro and in vivo.
Ceramide and Regulation of Vascular Tone
Authors: Cogolludo Angel , Villamor Eduardo , Perez-Vizcaino Francisco , Moreno Laura
Published: January 2019

In addition to playing a role as a structural component of cellular membranes, ceramide is now clearly recognized as a bioactive lipid implicated in a variety of physiological functions. This review aims to provide updated information on the role of ceramide in the regulation of vascular tone. Ceramide may induce vasodilator or vasoconstrictor effects by interacting with several signaling pathways in endothelial and smooth muscle cells. There is a clear, albeit complex, interaction between ceramide and redox signaling. In fact, reactive oxygen species (ROS) activate different ceramide generating pathways and, conversely, ceramide is known to increase ROS production. In recent years, ceramide has emerged as a novel key player in oxygen sensing in vascular cells and mediating vascular responses of crucial physiological relevance such as hypoxic pulmonary vasoconstriction (HPV) or normoxic ductus arteriosus constriction. Likewise, a growing body of evidence over the last years suggests that exaggerated production of vascular ceramide may have detrimental effects in a number of pathological processes including cardiovascular and lung diseases.
A New Approach for Improving the Antibacterial and Tumor Cytotoxic Activities of Pipemidic Acid by Including It in Trimethyl-β-cyclodextrin
Authors: Lavorgna Margherita , Iacovino Rosa , Russo Chiara , Di Donato Cristina , Piscitelli Concetta , Isidori Marina
Published: January 2019

Pipemidic acid (HPPA) is a quinolone antibacterial agent used mostly to treat gram-negative infections of the urinary tract, but its therapeutic use is limited because of its low solubility. Thus, to improve drug solubility, natural cyclodextrins (CDs) are used for their ability of including guest molecules within their cavities. The aim of this work was to evaluate the antibacterial activity and the preliminary anticancer activity of HPPA included into Heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) as a possible approach for a new innovative formulation. The inclusion complex of HPPA with TRIMEB was prepared in solid state by the kneading method and confirmed by FT-IR and powered X-ray diffraction. The association in aqueous solutions of pipemidic acid with TRIMEB was investigated by UV-Vis spectroscopy. Job’s plots have been drawn by UV-visible spectroscopy to confirm the 1:1 stoichiometry of the host–guest assembly. The antibacterial activity of HPPA, TRIMEB and of their complex was tested on Escherichia coli, Pseudomonas aeruginosa, and Staphilococcus aureus. The complex was able to increase 47.36% of the median antibacterial activity of the free HPPA against E. coli (IC50 = 249 µM vs. 473 µM). Furthermore, these samples were tested on HepG-2 and MCF-7. After 72 h, the median tumoral cytotoxicity exerted by the complex was increased by 78.08% and 94.27% for HepG-2 and MCF-7 respectively, showing a stronger bioactivity of the complex than the single HAPPA.
Prognostic Relevance of RIP140 and ERβ Expression in Unifocal Versus Multifocal Breast Cancers: A Preliminary Report
Authors: Müller Katharina , Sixou Sophie , Kuhn Christina , Jalaguier Stephan , Mayr Doris , Ditsch Nina , Weissenbacher Tobias , Harbeck Nadia , Mahner Sven , Cavaillès Vincent , Jeschke Udo
Published: January 2019

The aim of this study was to investigate the expression of two nuclear receptor transcriptional coregulators, namely RIP140 (receptor-interacting protein of 140 kDa) and LCoR (ligand-dependent corepressor) in unifocal versus multifocal breast cancers. The expression of these two proteins was analyzed by immunohistochemistry in a matched-pair cohort of 21 unifocal and 21 multifocal breast tumors. The expression of the two estrogen receptors (ERα and ERβ) was studied in parallel. RIP140 and LCoR levels appeared lower in unifocal tumors compared to multifocal samples (decreased of immune-reactive scores and reduced number of high expressing cells). In both tumor types, RIP140 and LCoR expression was correlated with each other and with expression of ERβ. Very interestingly, the expression of RIP140, LCoR, and ERβ was inversely correlated with overall survival only for the unifocal group. The negative correlation with overall and recurrence free survival was more pronounced in patients whose unifocal tumors expressed high levels of both RIP140 and ERβ. Altogether, this preliminary report indicates that the ERβ/RIP140 signaling is altered in unifocal breast cancers and correlated with patient outcome. Further investigation is needed to decipher the molecular mechanisms and the biological relevance of this deregulation.
Towards Personal Virtual Traffic Lights
Authors: Martins Vanessa , Rufino João , Silva Luis , Almeida João , Miguel Fernandes Silva Bruno , Ferreira Joaquim , Fonseca José
Published: January 2019

Traffic control management at intersections, a challenging and complex field of study, aims to strike a balance between safety and efficient traffic control. Nowadays, traffic control at intersections is typically done by traffic light systems which are not optimal and exhibit several drawbacks, such as poor efficiency and real-time adaptability. With the advent of Intelligent Transportation Systems (ITS), vehicles are being equipped with state-of-the-art technology, enabling cooperative decision-making which will certainly overwhelm the available traffic control systems. This solution strongly penalizes users without such capabilities, namely pedestrians, cyclists, and other legacy vehicles. Therefore, in this work, a prototype based on an alternative technology to the standard vehicular communications, Bluetooth Low Energy (BLE), is presented. The proposed framework aims to integrate legacy and modern vehicular communication systems into a cohesive management system. In this framework, the movements of users at intersections are managed by a centralized controller which, through the use of networked retransmitters deployed at intersections, broadcasts alerts and virtual light signalization orders. Users receive the aforementioned information on their own smart devices, discarding the need for dedicated light signalization infrastructures. Field tests, carried out with a real-world implementation, validate the correct operation of the proposed framework.
Termite Taxonomy, Challenges and Prospects: West Africa, A Case Example
Authors: Korb Judith , Kasseney Boris D. , Cakpo Yvonne Tété , Casalla Daza Robin H. , Gbenyedji Jean Norbert K. B. , Ilboudo Mayouré Edith , Josens Guy , Koné N’golo Abdoulaye , Meusemann Karen , Ndiaye Abdoulaye B. , Okweche Simon Idoko , Poulsen Michael , Roisin Yves , Sankara Fernand
Published: January 2019

Termites are important ecosystem engineers. Yet they are often difficult to identify due to the lack of reliable species-specific morphological traits for many species, which hampers ecological research. Recently, termitologists working with West African termites (West African Termite Taxonomy Initiative) convened for a workshop with the aim of beginning to address this problem. Repeated determination of the same termite samples by the most renowned taxonomists for West African termites identified the huge scale of the problem, as less than 10% of all species could be unambiguously determined to the species level. Intensive discussions and comparisons increased the identification success to around 25% at the end of the workshop. Yet many groups remained problematic and molecular markers and barcoding techniques combined with species delimitation approaches will be needed to help resolve these existing taxonomic problems. Based on the outcome of this workshop, we propose concerted initiatives to address termite taxonomy on a global scale. We are convinced that dedicated workshops on regional taxonomy that follow a similar structured approach, with repeated determination of the same sample, will help overcome the difficulties that termite taxonomy faces. This initiative can also serve as a blueprint for other taxonomical groups that are difficult to identify.
In Vitro Degradation of Absorbable Zinc Alloys in Artificial Urine
Authors: Champagne Sébastien , Mostaed Ehsan , Safizadeh Fariba , Ghali Edward , Vedani Maurizio , Hermawan Hendra
Published: January 2019

Absorbable metals have potential for making in-demand rigid temporary stents for the treatment of urinary tract obstruction, where polymers have reached their limits. In this work, in vitro degradation behavior of absorbable zinc alloys in artificial urine was studied using electrochemical methods and advanced surface characterization techniques with a comparison to a magnesium alloy. The results showed that pure zinc and its alloys (Zn–0.5Mg, Zn–1Mg, Zn–0.5Al) exhibited slower corrosion than pure magnesium and an Mg–2Zn–1Mn alloy. The corrosion layer was composed mostly of hydroxide, carbonate, and phosphate, without calcium content for the zinc group. Among all tested metals, the Zn–0.5Al alloy exhibited a uniform corrosion layer with low affinity with the ions in artificial urine.
Experimentation and Predictive Models for Properties of Concrete Added with Active and Inactive SiO2 Fillers
Authors: Abbass Wasim , Khan Mohammad Iqbal , Mourad Shehab
Published: January 2019

Cement is one of the main constituents of concrete material and it is one of the main sources of carbon dioxide emissions in the environment. Fillers within a range of 5–7% from different sources can be used as a replacement of cement without compromising the properties of concrete or even tailoring for required property. This paper investigates the influence of inactive silica filler and silica fume on the mechanical- and durability-related properties of concrete with different strengths. The investigated mechanical properties focused on compressive strength at different ages up to 400 days, while the durability-related properties focused on porosity and rapid chloride ion penetrability (RCPT). Two types of ultrafines, namely quartz ultrafine and silica fume, were used. Concrete mixtures with four different water/binder ratios (0.25, 0.30, 0.35, 0.40) were prepared for various dosages of quartz ultrafine (0%, 5%, 8%, 10%, 15%, 25%, and 35%) and different dosages of silica fume (0%, 8%, 10%, and 12%). The results revealed that the compressive strength and durability related properties of concrete with different dosages of ultrafines and silica fume were significantly affected; however, there was a negative impact of ultrafine filler on the compressive strength after replacement of more than 8% of ultrafines. The strength relationships for the concrete with different water-to-cement ratio were assessed and certain modifications were proposed for ultrafines and silica fume. Predictive models were proposed for predicting the compressive strength of concrete in terms of RCPT and porosity for different levels of replacements of ultrafines and silica fume.
Effect of (Tb+Y)/Al ratio on Microstructure Evolution and Densification Process of (Tb0.6Y0.4)3Al5O12 Transparent Ceramics
Authors: Wan Zhong , Wang Yinzhen , Zhang Jian , Wang Shiwei , Han Dan , Wang Junping , Wang Dewen
Published: January 2019

(Tb0.6Y0.4)3Al5O12 transparent ceramics were successfully fabricated by solid-state reactive sintering using Tb4O7, Y2O3, and α-Al2O3 powders as raw materials. The effect of (Tb+Y)/Al ratio on microstructure evolution and densification process was investigated in detailed. The results showed that the grain growth kinetics were significantly affected by (Tb+Y)/Al ratio. Al-rich and Tb-rich phases appeared in part of the samples of different ratios. Particularly, excess aluminum increased the diffusing process, leading to a higher densification rate, while samples with excess terbium ratios displayed a smaller grain size and lower relative density. The optical quality was highly related to the amount of the secondary phase produced by different (Tb+Y)/Al ratios. Finally, (Tb0.6Y0.4)3Al5O12 transparent ceramics have been fabricated through pre-sintering in vacuum, followed by hot isostatic sintering (HIP), and the best transmittance of sample with a 4 mm thickness was approximately 78% at 1064 nm.
The Effect of UV Illumination on the Room Temperature Detection of Vaporized Ammonium Nitrate by a ZnO Coated Nanospring-Based Sensor
Authors: Bastatas Lyndon D. , Wagle Phadindra , Echeverria Elena , Austin Aaron J. , McIlroy David N.
Published: January 2019

The effect of UV illumination on the room temperature electrical detection of ammonium nitrate vapor was examined. The sensor consists of a self-assembled ensemble of silica nanosprings coated with zinc oxide. UV illumination mitigates the baseline drift of the resistance relative to operation under dark conditions. It also lowers the baseline resistance of the sensor by 25% compared to dark conditions. At high ammonium nitrate concentrations (120 ppm), the recovery time after exposure is virtually identical with or without UV illumination. At low ammonium nitrate concentrations (20 ppm), UV illumination assists with refreshing of the sensor by stimulating analyte desorption, thereby enabling the sensor to return to its baseline resistance. Under dark conditions and low ammonium nitrate concentrations, residual analyte builds up with each exposure, which inhibits the sensor from returning to its original baseline resistance and subsequently impedes sensing due to permanent occupation of absorption sites.
Synthesis of Structurally Precise Polysiloxanes via the Piers–Rubinsztajn Reaction
Authors: Chen Xunjun , Yi Minghao , Wu Shufang , Tan Lewen , Ge Xin , He Ming , Yin Guoqiang
Published: January 2019

Silicone materials are widely used, from daily life to the military industry. With the advancement of science and technology and the increasing demands of industry, the requirement for high-performance precise structural silicone materials has increased. Therefore, the most important aspect in this field is finding a breakthrough in the synthetic methods. In this review, the latest research developments in controllable morphological structure and composite structure optimized synthesis of silicone materials using the Piers–Rubinsztajn (PR) reaction are summarized. The advantages of the PR reaction compared with traditional synthetic routes to silicone materials are presented. The highly controllable spatial structure of silicone materials and the structural combination of biomass or inorganic materials with silicone materials results in an improvement in performance or function. The morphological control of more complex silicone materials and the synthesis of non-traditional silicone materials with composite structures through the PR reaction will be the main research directions for the development of silicone materials in the future.
A Comparison of Ethylene-Tar-Derived Isotropic Pitches Prepared by Air Blowing and Nitrogen Distillation Methods and Their Carbon Fibers
Authors: Shi Kui , Yang Jianxiao , Ye Chong , Liu Hongbo , Li Xuanke
Published: January 2019

Two isotropic pitches were prepared by air blowing and nitrogen distillation methods using ethylene tar (ET) as a raw material. The corresponding carbon fibers were obtained through conventional melt spinning, stabilization, and carbonization. The structures and properties of the resultant pitches and fibers were characterized, and their differences were examined. The results showed that the introduction of oxygen by the air blowing method could quickly increase the yield and the softening point of the pitch. Moreover, the air-blown pitch (ABP) was composed of aromatic molecules with linear methylene chains, while the nitrogen-distilled pitch (NDP) mainly contained polycondensed aromatic rings. This is because the oxygen-containing functional groups in the ABP could impede ordered stack of pitch molecules and led to a methylene bridge structure instead of an aromatic condensed structure as in the NDP. Meanwhile, the spinnability of the ABP did not decrease even though it contained 2.31 wt % oxygen. In contrast, the ABP had narrower molecular weight distribution, which contributed to better stabilization properties and higher tensile strength of the carbon fiber. The tensile strength of carbon fibers from the ABP reached 860 MPa with fiber diameter of about 10 μm, which was higher than the tensile strength of 640 MPa for the NDP-derived carbon fibers.
Electrolyte-Supported Fuel Cell: Co-Sintering Effects of Layer Deposition on Biaxial Strength
Authors: Masini Alessia , Strohbach Thomas , Šiška Filip , Chlup Zdeněk , Dlouhý Ivo
Published: January 2019

The mechanical reliability of reversible solid oxide cell (SOC) components is critical for the development of highly efficient, durable, and commercially competitive devices. In particular, the mechanical integrity of the ceramic cell, also known as membrane electrolyte assembly (MEA), is fundamental as its failure would be detrimental to the performance of the whole SOC stack. In the present work, the mechanical robustness of an electrolyte-supported cell was determined via ball-on-3-balls flexural strength measurements. The main focus was to investigate the effect of the manufacturing process (i.e., layer by layer deposition and their co-sintering) on the final strength. To allow this investigation, the electrode layers were screen-printed one by one on the electrolyte support and thus sintered. Strength tests were performed after every layer deposition and the non-symmetrical layout was taken into account during mechanical testing. Obtained experimental data were evaluated with the help of Weibull statistical analysis. A loss of mechanical strength after every layer deposition was usually detected, with the final strength of the cell being significantly smaller than the initial strength of the uncoated electrolyte (σ0 ≈ 800 MPa and σ0 ≈ 1800 MPa, respectively). Fractographic analyses helped to reveal the fracture behavior changes when individual layers were deposited. It was found that the reasons behind the weakening effect can be ascribed to the presence and redistribution of residual stresses, changes in the crack initiation site, porosity of layers, and pre-crack formation in the electrode layers.
An Efficient Spectral Method to Solve Multi-Dimensional Linear Partial Different Equations Using Chebyshev Polynomials
Authors: Oh Sahuck
Published: January 2019

We present a new method to efficiently solve a multi-dimensional linear Partial Differential Equation (PDE) called the quasi-inverse matrix diagonalization method. In the proposed method, the Chebyshev-Galerkin method is used to solve multi-dimensional PDEs spectrally. Efficient calculations are conducted by converting dense equations of systems sparse using the quasi-inverse technique and by separating coupled spectral modes using the matrix diagonalization method. When we applied the proposed method to 2-D and 3-D Poisson equations and coupled Helmholtz equations in 2-D and a Stokes problem in 3-D, the proposed method showed higher efficiency in all cases than other current methods such as the quasi-inverse method and the matrix diagonalization method in solving the multi-dimensional PDEs. Due to this efficiency of the proposed method, we believe it can be applied in various fields where multi-dimensional PDEs must be solved.
In Vitro Antithrombotic Properties of Salmon (Salmo salar) Phospholipids in a Novel Food-Grade Extract
Authors: Tsoupras Alexandros , Lordan Ronan , Shiels Katie , Saha Sushanta Kumar , Nasopoulou Constantina , Zabetakis Ioannis
Published: January 2019

Marine and salmon polar lipids (PLs) extracted by conventional extractions with non-food-grade solvents (CE-salmon-PLs) possess antithrombotic bioactivities against platelet-activating factor (PAF) and thrombin. Similar effects of food-grade-extracted (FGE) marine PLs have not yet been reported. In this study, food-grade solvents were used to extract PLs from Irish organic farmed salmon (Salmo salar) fillets (FGE-salmon-PLs), while their antithrombotic bioactivities were assessed in human platelets induced by platelet aggregation agonists (PAF/thrombin). FGE-salmon-PLs were further separated by thin layer chromatography (TLC) into lipid subclasses, and the antithrombotic bioactivities of each subclass were also assessed. LC-MS was utilized to elucidate the structure-activity relationships. FGE-salmon-PLs strongly inhibited PAF-induced platelet aggregation, while their relevant anti-thrombin effects were at least three times more potent than the previously reported activities of CE-salmon-PLs. TLC-derived lipid fractions corresponding to phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the most bioactive lipid subclasses obtained, especially against thrombin. Their LC-MS analysis elucidated that they are diacyl- or alkyl-acyl- PC and PE moieties baring ω3 polyunsaturated fatty acids (PUFA) at their sn-2 position, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Our results concerning the potent antithrombotic effects of FGE-salmon-PLs against both PAF and thrombin pathways strongly suggest that such food-grade extracts are putative candidates for the development of novel cardioprotective supplements and nutraceuticals.