bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuity of Physicians’ Dedication to Inpatient Hospice and Palliative Care: A 14-year Nationwide Survey in Taiwan
Authors: Cheng Bo-Ren , Lin Ming-Hwai , Chang Hsiao-Ting , Wang Yi-Jen , Chen Tzeng-Ji , Chou Li-Fang , Hwang Shinn-Jang
Published: August 2019

Background: The work continuity of physicians in hospice and palliative medicine (HPM) has a great impact on the quality of care and practice experiences. However, nationwide studies providing a general overview of the work continuity of HPM physicians are scarce. Methods: Data relating to inpatient HPM care provided from July 2000 to December 2013 were obtained from the National Health Insurance Research Database of Taiwan. Specifically, the numbers of hospitals, patients, patient hospitalization days, and physicians involving HPM in each year were calculated. The years of HPM work experience and total HPM workdays of each physician were also computed. Results: Of the 40,965,153 inpatient records during the study, 121,258 (0.3%) records were related to inpatient HPM care, with 60 participating hospitals and 604 attending physicians. The annual number of HPM physicians increased with time from 77 in 2000 to 217 in 2013. The largest percentage (38.4%) of physicians practiced HPM for only one year, while only 23 (3.8%) physicians practiced HPM in each year without interruption. Of the 217 HPM physicians in 2013, 45 (20.7%) were newcomers, 78 (36.0%) had 1–4 years of prior HPM work experience, 54 (24.9%) had 5–9 years, and 40 (18.4%) had at least 10 years. Conclusions: Among HPM physicians in Taiwan, only a small percentage exhibited long-term dedication to the field, whereas most HPM physicians had short practice periods. More strategies are needed to improve work continuity among HPM physicians.
Green Public Procurement at a Regional Level. Case Study: The Valencia Region of Spain
Authors: Fuentes-Bargues Jose Luis , Ferrer-Gisbert Pablo Sebastian , González-Cruz Mª Carmen , Bastante-Ceca María Jose
Published: August 2019

Research on current practices and the state of green public procurement enables the identification of areas that can be improved, as well as opportunities to improve the tendering procedures from an environmental point of view. To understand the behaviour of local, provincial, and regional administrations concerning green public procurement, a case study on the Valencia region of Spain is made. The Valencian region is one of the most important communities in terms of population, number of contracting authorities, and weight in the Spanish Gross Domestic Product. In this study, a total of 967 procedures were analysed from calls for tenders made by municipal, provincial, and regional administrations in2016 and 2017.The results of this study show that the use of environmental criteria is 19.7% and the average weight is 4.1 out of 100. The civil engineering subsector, more than the building subsector, employs environmental criteria, particularly in projects tendered by regional administrations, whereas for projects with large budgets the level of use is similar for both subsectors. It is necessary to encourage plans to improve Green Public Procurement (GPP) practices in the Valencian administrations, especially those with a local scope such as municipalities.
Evaluation of Policies on Inappropriate Treatment of Dead Hogs from the Perspective of Loss Aversion
Authors: Yang Chenchen , Wang Jianhua
Published: August 2019

Punishment policies on the inappropriate treatment of dead hogs play a key role in safeguarding public health and environmental protection. These policies aim to regulate the behavior of farmers and promote the development of sustainable agriculture. Farmers’ evaluation of a policy can be used to measure its effectiveness, and loss aversion is a factor that has been little studied. This study surveyed 404 hog farmers in China, and analyzed the factors that influenced their evaluation of the penalties for the inappropriate treatment of dead hogs during 2016 and 2017. We used three indicators for the evaluation of the penalties: the degree of necessity, implementation, and effectiveness. Special attention was paid to farmers’ aversion to financial penalties and police detention time, which was elicited using economic experiments. The results show that farmers are more likely to be averse to police detention time than financial penalties, and suggest that the level of each indicator needs to be increased. The results from an ordered Probit model show that there are both similarities and differences between the formation paths of the three indicators. An aversion to financial penalties will help to improve the degree of implementation. An aversion to police detention time will lead to a negative trend in the degree of effectiveness. An in-depth analysis of the factors that influence farmers’ evaluation of policies to punish inappropriate treatment of dead hogs may provide a basis for the design of government policies to improve environmental protection performance.
Computational Mechanistic Insights on the NO Oxidation Reaction Catalyzed by Non-Heme Biomimetic Cr-N-Tetramethylated Cyclam Complexes
Authors: Marino Tiziana , Fortino Maria Grazia , Russo Nino , Toscano Marirosa , Alberto Marta Erminia
Published: August 2019

The conversion reaction of NO to NO3− ion catalyzed by the end-on [Cr(III)(n-TMC)(O2)(Cl)]+ superoxo and side-on [Cr(IV)(n-TMC)(O2)(Cl)]+ peroxo non-heme complexes (n = 12, 13, 14 and 15), which are biomimetic systems of nitric oxide dioxygenases (NODs), has been explored using a computational protocol in the framework of density functional theory. Results show that the potential energy profiles for the studied reactions lie above the reagent energies, regardless of the used catalyst. Both the O-O bond breaking in the biomimetics and the NO3− ion formation require low energy barriers suggesting an efficient catalytic power of the studied systems. The rate-determining step depends on ligand size.
Development of an Exercise Training Protocol to Investigate Arteriogenesis in a Murine Model of Peripheral Artery Disease
Authors: Bresler Ayko , Vogel Johanna , Niederer Daniel , Gray Daphne , Schmitz-Rixen Thomas , Troidl Kerstin
Published: August 2019

Exercise is a treatment option in peripheral artery disease (PAD) patients to improve their clinical trajectory, at least in part induced by collateral growth. The ligation of the femoral artery (FAL) in mice is an established model to induce arteriogenesis. We intended to develop an animal model to stimulate collateral growth in mice through exercise. The training intensity assessment consisted of comparing two different training regimens in C57BL/6 mice, a treadmill implementing forced exercise and a free-to-access voluntary running wheel. The mice in the latter group covered a much greater distance than the former pre- and postoperatively. C57BL/6 mice and hypercholesterolemic ApoE-deficient (ApoE−/−) mice were subjected to FAL and had either access to a running wheel or were kept in motion-restricting cages (control) and hind limb perfusion was measured pre- and postoperatively at various times. Perfusion recovery in C57BL/6 mice was similar between the groups. In contrast, ApoE−/− mice showed significant differences between training and control 7 d postoperatively with a significant increase in pericollateral macrophages while the collateral diameter did not differ between training and control groups 21 d after surgery. ApoE−/− mice with running wheel training is a suitable model to simulate exercise induced collateral growth in PAD. This experimental set-up may provide a model for investigating molecular training effects.
Chlorin e6-Loaded PEG-PCL Nanoemulsion for Photodynamic Therapy and In Vivo Drug Delivery
Authors: Park Changhee , Yoo Jihye , Lee Donghyun , Jang Seok-young , Kwon Soonmin , Koo Heebeom
Published: August 2019

We fabricated poly (ethylene glycol)-block-polycaprolactone (PEG-b-PCL) nanoemulsion for drug delivery and photodynamic therapy. PEG-b-PCL effectively stabilized the interface between water and soybean oil, and the resulting nanoemulsion was about 220.3 nm in diameter with spherical shape. For photodynamic therapy (PDT), chlorin e6 (Ce6) was loaded into the nanoemulsion as a photosensitizer (PS). These chlorin e6-loaded PEG-PCL nanoemulsions (Ce6-PCL-NEs) showed efficient cellular uptake and, upon laser irradiation, generated singlet oxygen to kill tumor cells. Particularly, Ce6-PCL-NEs showed prolonged blood circulation and about 60% increased tumor accumulation compared to free Ce6 after intravenous injection to 4T1 tumor-bearing mice. These results demonstrate the promising potential of Ce6-PCL-NEs for efficient PDT and in vivo drug delivery to tumor tissue.
Targeting Cellular Metabolism Modulates Head and Neck Oncogenesis
Authors: Hsieh Yi-Ta , Chen Yi-Fen , Lin Shu-Chun , Chang Kuo-Wei , Li Wan-Chun
Published: August 2019

Considering the great energy and biomass demand for cell survival, cancer cells exhibit unique metabolic signatures compared to normal cells. Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent neoplasms worldwide. Recent findings have shown that environmental challenges, as well as intrinsic metabolic manipulations, could modulate HNSCC experimentally and serve as clinic prognostic indicators, suggesting that a better understanding of dynamic metabolic changes during HNSCC development could be of great benefit for developing adjuvant anti-cancer schemes other than conventional therapies. However, the following questions are still poorly understood: (i) how does metabolic reprogramming occur during HNSCC development? (ii) how does the tumorous milieu contribute to HNSCC tumourigenesis? and (iii) at the molecular level, how do various metabolic cues interact with each other to control the oncogenicity and therapeutic sensitivity of HNSCC? In this review article, the regulatory roles of different metabolic pathways in HNSCC and its microenvironment in controlling the malignancy are therefore discussed in the hope of providing a systemic overview regarding what we knew and how cancer metabolism could be translated for the development of anti-cancer therapeutic reagents.
BrTCP7 Transcription Factor Is Associated with MeJA-Promoted Leaf Senescence by Activating the Expression of BrOPR3 and BrRCCR
Authors: Xu Yan-mei , Xiao Xian-mei , Zeng Ze-xiang , Tan Xiao-li , Liu Zong-li , Chen Jian-wen , Su Xin-guo , Chen Jian-ye
Published: August 2019

The plant hormone jasmonic acid (JA) has been recognized as an important promoter of leaf senescence in plants. However, upstream transcription factors (TFs) that control JA biosynthesis during JA-promoted leaf senescence remain unknown. In this study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP7 in methyl jasmonate (MeJA)-promoted leaf senescence in Chinese flowering cabbage. Exogenous MeJA treatment reduced maximum quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the increased expression of senescence marker and chlorophyll catabolic genes, and accelerated leaf senescence. To further understand the transcriptional regulation of MeJA-promoted leaf senescence, a class I member of TCP TFs BrTCP7 was examined. BrTCP7 is a nuclear protein and possesses trans-activation ability through subcellular localization and transcriptional activity assays. A higher level of BrTCP7 transcript was detected in senescing leaves, and its expression was up-regulated by MeJA. The electrophoretic mobility shift assay and transient expression assay showed that BrTCP7 binds to the promoter regions of a JA biosynthetic gene BrOPR3 encoding OPDA reductase3 (OPR3) and a chlorophyll catabolic gene BrRCCR encoding red chlorophyll catabolite reductase (RCCR), activating their transcriptions. Taken together, these findings reveal that BrTCP7 is associated with MeJA-promoted leaf senescence at least partly by activating JA biosynthesis and chlorophyll catabolism, thus expanding our knowledge of the transcriptional mechanism of JA-mediated leaf senescence.
Rehmannia glutinosa Libosch Extracts Prevent Bone Loss and Architectural Deterioration and Enhance Osteoblastic Bone Formation by Regulating the IGF-1/PI3K/mTOR Pathway in Streptozotocin-Induced Diabetic Rats
Authors: Gong Wan , Zhang Naidan , Cheng Gang , Zhang Quanlong , He Yuqiong , Shen Yi , Zhang Qi , Zhu Bo , Zhang Qiaoyan , Qin Luping
Published: August 2019

Rehmanniae Radix Praeparata (RR, named as Shudihuang in traditional Chinese medicine), the steamed roots of Rehmannia glutinosa Libosch (Scrophulariaceae), has been demonstrated to have anti-diabetic and anti-osteoporotic activities. This study aimed to explore the protective effect and underlying mechanism of RR on diabetes-induced bone loss. It was found that RR regulated the alkaline phosphatase activity and osteocalcin level, enhanced bone mineral density, and improved the bone microarchitecture in diabetic rats. The catalpol (CAT), acteoside (ACT), and echinacoside (ECH) from RR increased the proliferation and differentiation of osteoblastic MC3T3-E1 cells injured by high glucose and promoted the production of IGF-1 and expression of related proteins in BMP and IGF-1/PI3K/mammalian target of rapamycin complex 1 (mTOR) signaling pathways. The verifying tests of inhibitors of BMP pathway (noggin) and IGF-1/PI3K/mTOR pathway (picropodophyllin) and molecular docking of IGF-1R further indicated that CAT, ACT, and ECH extracted from RR enhanced bone formation by regulating IGF-1/PI3K/mTOR signaling pathways. These findings suggest that RR may prove to be a promising candidate drug for the prevention and treatment of diabetes-induced osteoporosis.
Modulating Expression of Thioredoxin Interacting Protein (TXNIP) Prevents Secondary Damage and Preserves Visual Function in a Mouse Model of Ischemia/Reperfusion
Authors: Coucha Maha , Shanab Ahmed Y. , Sayed Mohamed , Vazdarjanova Almira , El-Remessy Azza B.
Published: August 2019

Retinal neurodegeneration, an early characteristic of several blinding diseases, triggers glial activation, resulting in inflammation, secondary damage and visual impairment. Treatments that aim only at neuroprotection have failed clinically. Here, we examine the impact of modulating thioredoxin interacting protein (TXNIP) to the inflammatory secondary damage and visual impairment in a model of ischemia/reperfusion (IR). Wild type (WT) and TXNIP knockout (TKO) mice underwent IR injury by increasing intraocular pressure for 40 min, followed by reperfusion. An additional group of WT mice received intravitreal TXNIP-antisense oligomers (ASO, 100 µg/2 µL) 2 days post IR injury. Activation of Müller glial cells, apoptosis and expression of inflammasome markers and visual function were assessed. IR injury triggered early TXNIP mRNA expression that persisted for 14 days and was localized within activated Müller cells in WT-IR, compared to sham controls. Exposure of Müller cells to hypoxia-reoxygenation injury triggered endoplasmic reticulum (ER) stress markers and inflammasome activation in WT cells, but not from TKO cells. Secondary damage was evident by the significant increase in the number of occluded acellular capillaries and visual impairment in IR-WT mice but not in IR-TKO. Intervention with TXNIP-ASO prevented ischemia-induced glial activation and neuro-vascular degeneration, and improved visual function compared to untreated WT. Targeting TXNIP expression may offer an effective approach in the prevention of secondary damage associated with retinal neurodegenerative diseases.
Targeting Mitochondrial Fission Using Mdivi-1 in A Clinically Relevant Large Animal Model of Acute Myocardial Infarction: A Pilot Study
Authors: Ong Sang-Bing , Kwek Xiu-Yi , Katwadi Khairunnisa , Hernandez-Resendiz Sauri , Crespo-Avilan Gustavo , Ismail Nur , Lin Ying-Hsi , Yap En , Lim Song-Yi , Ja K , Ramachandra Chrishan , Tee Nicole , Toh Jin , Shim Winston , Wong Philip , Cabrera-Fuentes Hector , Hausenloy Derek
Published: August 2019

Background: New treatments are needed to reduce myocardial infarct size (MI) and prevent heart failure (HF) following acute myocardial infarction (AMI), which are the leading causes of death and disability worldwide. Studies in rodent AMI models showed that genetic and pharmacological inhibition of mitochondrial fission, induced by acute ischemia and reperfusion, reduced MI size. Whether targeting mitochondrial fission at the onset of reperfusion is also cardioprotective in a clinically-relevant large animal AMI model remains to be determined. Methods: Adult pigs (30–40 kg) were subjected to closed-chest 90-min left anterior descending artery ischemia followed by 72 h of reperfusion and were randomized to receive an intracoronary bolus of either mdivi-1 (1.2 mg/kg, a small molecule inhibitor of the mitochondrial fission protein, Drp1) or vehicle control, 10-min prior to reperfusion. The left ventricular (LV) size and function were both assessed by transthoracic echocardiography prior to AMI and after 72 h of reperfusion. MI size and the area-at-risk (AAR) were determined using dual staining with Tetrazolium and Evans blue. Heart samples were collected for histological determination of fibrosis and for electron microscopic analysis of mitochondrial morphology. Results: A total of 14 pigs underwent the treatment protocols (eight control and six mdivi-1). Administration of mdivi-1 immediately prior to the onset of reperfusion did not reduce MI size (MI size as % of AAR: Control 49.2 ± 8.6 vs. mdivi-1 50.5 ± 11.4; p = 0.815) or preserve LV systolic function (LV ejection fraction %: Control 67.5 ± 0.4 vs. mdivi-1 59.6 ± 0.6; p = 0.420), when compared to vehicle control. Similarly, there were no differences in mitochondrial morphology or myocardial fibrosis between mdivi-1 and vehicle control groups. Conclusion: Our pilot study has shown that treatment with mdivi-1 (1.2 mg/kg) at the onset of reperfusion did not reduce MI size or preserve LV function in the clinically-relevant closed-chest pig AMI model. A larger study, testing different doses of mdivi-1 or using a more specific Drp1 inhibitor are required to confirm these findings.
Hydrogen Sulfide Attenuates Hydrogen Peroxide-Induced Injury in Human Lung Epithelial A549 Cells
Authors: Wang Mingqi , Cao Xinyu , Luan Chang , Li Zhengqiang
Published: August 2019

Lung tissues are frequently exposed to a hyperoxia environment, which leads to oxidative stress injuries. Hydrogen sulfide (H2S) is widely implicated in physiological and pathological processes and its antioxidant effect has attracted much attention. Therefore, in this study, we used hydrogen peroxide (H2O2) as an oxidative damage model to investigate the protective mechanism of H2S in lung injury. Cell death induced by H2O2 treatment could be significantly attenuated by the pre-treatment of H2S, resulting in a decrease in the Bax/Bcl-2 ratio and the inhibition of caspase-3 activity in human lung epithelial cell line A549 cells. Additionally, the results showed that H2S decreased reactive oxygen species (ROS), as well as neutralized the damaging effects of H2O2 in mitochondria energy-producing and cell metabolism. Pre-treatment of H2S also decreased H2O2-induced suppression of endogenous H2S production enzymes, cystathionine-beta-synthase (CBS), cystathionine-gamma-lyase (CSE), and 3-mercapto-pyruvate sulfurtransferase (MPST). Furthermore, the administration of H2S attenuated [Ca2+] overload and endoplasmic reticulum (ER) stress through the mitogen-activated protein kinase (MAPK) signaling pathway. Therefore, H2S might be a potential therapeutic agent for reducing ROS and ER stress-associated apoptosis against H2O2-induced lung injury.
A Computational Analysis of Alternative Splicing across Mammalian Tissues Reveals Circadian and Ultradian Rhythms in Splicing Events
Authors: El-Athman Rukeia , Knezevic Dora , Fuhr Luise , Relógio Angela
Published: August 2019

Mounting evidence points to a role of the circadian clock in the temporal regulation of post-transcriptional processes in mammals, including alternative splicing (AS). In this study, we carried out a computational analysis of circadian and ultradian rhythms on the transcriptome level to characterise the landscape of rhythmic AS events in published datasets covering 76 tissues from mouse and olive baboon. Splicing-related genes with 24-h rhythmic expression patterns showed a bimodal distribution of peak phases across tissues and species, indicating that they might be controlled by the circadian clock. On the output level, we identified putative oscillating AS events in murine microarray data and pairs of differentially rhythmic splice isoforms of the same gene in baboon RNA-seq data that peaked at opposing times of the day and included oncogenes and tumour suppressors. We further explored these findings using a new circadian RNA-seq dataset of human colorectal cancer cell lines. Rhythmic isoform expression patterns differed between the primary tumour and the metastatic cell line and were associated with cancer-related biological processes, indicating a functional role of rhythmic AS that might be implicated in tumour progression. Our data shows that rhythmic AS events are widespread across mammalian tissues and might contribute to a temporal diversification of the proteome.
Improved Survival in Hepatocellular Carcinoma Patients with Cardiac Arrhythmia by Amiodarone Treatment through Autophagy
Authors: Huang Sheng-Teng , Hsu Wei-Fan , Huang Hung-Sen , Yen Jia-Hau , Lin Mei-Chen , Peng Cheng-Yuan , Yen Hung-Rong
Published: August 2019

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver. In basic studies, the regulation of autophagy has offered promising results for HCC treatment. This study aimed to address the question of whether amiodarone can improve survival rates in HCC patients associated with autophagy. Using datasets from the National Health Insurance Research Database, we enrolled patients over 18 years of age that had been diagnosed with HCC between January 1997 and December 2010. Amiodarone and non-amiodarone users were matched at a 1:1 frequency, according to all variables. Additionally, HepG2 cells treated with amiodarone were evaluated by cell viability and autophagic change. Autophagic signaling was examined by immunoblotting and tissue array immunohistochemistry. Of the 10,946 patients diagnosed with HCC, each cohort included 221 patients after 1:1 propensity score matching. The median survival was 36.70 months for the amiodarone users, and 24.48 months for the non-amiodarone users. After adjusting for age, gender, comorbidities and treatment, amiodarone users had a significantly lower risk of mortality. Amiodarone users also demonstrated an improved 3-year survival rate. Furthermore, amiodarone treatment-induced autophagy in HepG2 cells was demonstrated by autophagosome formation associated with increasing LC3B-II, P62, and Beclin-1 expression. Autophagic flux also increased following amiodarone treatment with bafilomycin A1. SiRNA of LC3B knocked down endogenous LC3B formation and restored HepG2 cell viability. This study provides epidemiologic evidence that amiodarone via autophagic degradation machinery may offer survival benefits for HCC patients with a history of arrhythmia. Further randomized, blinded, and placebo-controlled trials are warranted for patients with HCC.
Role of miRNAs in Alzheimer’s Disease and Possible Fields of Application
Authors: Silvestro Serena , Bramanti Placido , Mazzon Emanuela
Published: August 2019

miRNAs (or microRNAs) are a class of single-stranded RNA molecules, responsible for post-transcriptional gene silencing through binding to the coding region as well as 3′ and 5′ untranslated region of target genes. About 70% of experimentally detectable miRNAs are expressed in the brain and some studies suggest that miRNAs are intimately involved in synaptic function and in specific signals during memory formation. More and more evidence demonstrates the possible involvement of miRNAs in Alzheimer’s disease (AD). AD is the most common form of senile dementia, a disease that affects memory and cognitive functions. It is a neurodegenerative disorder characterized by loss of synapses, extracellular amyloid plaques composed of the amyloid-β peptide (Aβ), and intracellular aggregates of hyperphosphorylated TAU protein. This review aims to provide an overview of the in vivo studies of the last 5 years in the literature describing the role of the different miRNAs involved in AD. miRNAs hold huge potential as diagnostic and prognostic biomarkers and, at the same time, their modulation could be a potential therapeutic strategy against AD.
Review of the D2D Trusted Cooperative Mechanism in Mobile Edge Computing
Authors: Yuan Jie , Li Erxia , Kang Chaoqun , Chang Fangyuan , Li Xiaoyong
Published: August 2019

Mobile edge computing (MEC) effectively integrates wireless network and Internet technologies and adds computing, storage, and processing functions to the edge of cellular networks. This new network architecture model can deliver services directly from the cloud to the very edge of the network while providing the best efficiency in mobile networks. However, due to the dynamic, open, and collaborative nature of MEC network environments, network security issues have become increasingly complex. Devices cannot easily ensure obtaining satisfactory and safe services because of the numerous, dynamic, and collaborative character of MEC devices and the lack of trust between devices. The trusted cooperative mechanism can help solve this problem. In this paper, we analyze the MEC network structure and device-to-device (D2D) trusted cooperative mechanism and their challenging issues and then discuss and compare different ways to establish the D2D trusted cooperative relationship in MEC, such as social trust, reputation, authentication techniques, and intrusion detection. All these ways focus on enhancing the efficiency, stability, and security of MEC services in presenting trustworthy services.
Biological Effects of New Hydraulic Materials on Human Periodontal Ligament Stem Cells
Authors: López-García Sergio , Lozano Adrián , García-Bernal David , Forner Leopoldo , Llena Carmen , Guerrero-Gironés Julia , Moraleda José M. , Murcia Laura , Rodríguez-Lozano Francisco J.
Published: August 2019

Background: The aim of this study was: to evaluate the biological properties of new hydraulic materials: Bio-C Repair and Bio-C Sealer. Methods: Periodontal ligament stem cells were exposed to several dilutions of Bio-C Repair and Bio-C Sealer. The ion release profile and pH were determined. Metabolic activity, cell migration and cell survival were assessed using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), wound-healing assays and Annexin assays, respectively. Cells were cultured in direct contact with the surface of each material. These were then analyzed via scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Statistical differences were assessed using a two-way ANOVA (α < 0.05). Results: Similar pH was observed in these cements. Bio-C Sealer released significantly more Ca and Si ions (p < 0.05) in comparison with Bio-C Repair. Undiluted Bio-C Sealer induced a significant reduction on cellular viability, cell survival and cell migration when compared to the control (p < 0.05). Moreover, SEM showed abundant cells adhered on Bio-C Repair and a moderate number of cells attached on Bio-C Sealer. Finally, EDX analysis identified higher percentages of Ca and O in the case of Bio-C repair than with Bio-C sealer, while other elements such as Zr and Si were more abundant in Bio-C sealer. Conclusions: Bio-C Repair displayed higher cell viability, cell adhesion and migration rates than Bio-C Sealer.
Community Perceptions of Tourism Impacts on Coastal Protected Areas
Authors: Navarro Nuria
Published: August 2019

The Dominican Republic is one of the countries with the highest growing number of tourists in coastal protected areas. The objective of this study was to examine the perceived impact of tourism on three coastal national parks, involving all the sectors related to these protected areas and tourism. Workshops were carried out in the coastal protected areas studied. The results revealed the poor integration of local communities in the management plans, the lack of information on protected areas, and the poverty of the majority of the resident families despite income of tourism. The findings of this study highlighted the concept of a carrying capacity or threshold for tourism development. Lower to moderate levels of tourism development appeared beneficial, but as tourism development increased, perceptions of the community worsened. The results also confirmed that tourism contributes to environmental degradation, mainly due to contamination of rivers and coastlines, accumulation of waste, and over-exploitation of natural resources. A series of strategies is proposed to minimize this impact.
Detection and Characterization of Meteotsunamis in the Gulf of Genoa
Authors: Picco Paola , Schiano Maria Elisabetta , Incardone Silvio , Repetti Luca , Demarte Maurizio , Pensieri Sara , Bozzano Roberto
Published: August 2019

A long-term time series of high-frequency sampled sea-level data collected in the port of Genoa were analyzed to detect the occurrence of meteotsunami events and to characterize them. Time-frequency analysis showed well-developed energy peaks on a 26–30 minute band, which are an almost permanent feature in the analyzed signal. The amplitude of these waves is generally few centimeters but, in some cases, they can reach values comparable or even greater than the local tidal elevation. In the perspective of sea-level rise, their assessment can be relevant for sound coastal work planning and port management. Events having the highest energy were selected for detailed analysis and the main features were identified and characterized by means of wavelet transform. The most important one occurred on 14 October 2016, when the oscillations, generated by an abrupt jump in the atmospheric pressure, achieved a maximum wave height of 50 cm and lasted for about three hours.
Translingual Practices and Reconstruction of Identities in Maghrebi Students in Galicia
Authors: Moustaoui Srhir Adil , Prego Vázquez Gabriela , Zas Varela Luz
Published: August 2019

In this article, we explore the emergence of a new translingual repertoire among young adolescents of Moroccan and Algerian origin in Galicia and the role it plays in reconstructing the transnational identity of young people within the Maghrebi diaspora. The data include a multimodal corpus with spoken and written interactions, collected as part of a classroom action research project, in which each student reconstructed their family and school language repertoire, as well as a WhatsApp group chat set up with the same young people. The results of our analysis reveal how the intercrossing of parental and adolescent agency plays a crucial role in dealing with the new multilingual translingual repertoire. The findings also indicate how this repertoire is deeply rooted in Moroccan Arabic as the family language and the incorporation of local languages, namely Spanish and Galician, and relies heavily on translingual multimodal practices, associated with transnational trajectories and the local schooling process of these young people.
Ethyl 6-Methyl-2-oxo-4-{4-[(1-phenyl-1H-1,2,3-triazol-4-yl)methoxy]phenyl}-1,2,3,4-tetrahydropyrimidine-5-carboxylate
Authors: Gonçalves Itamar Luís , Azambuja Gabriel Oliveira de , Davi Leonardo , Gonçalves Guilherme Arraché , Kagami Luciano Porto , Neves Gustavo Machado das , Silveira João Pedro , Canto Rômulo Faria Santos , Eifler-Lima Vera Lucia
Published: August 2019

The Biginelli reaction is an acid-catalyzed, three-component reaction between an aldehyde, a hydrogen methylene active compound, and urea (or its analogue) and constitutes a rapid and easy synthesis of highly functionalized heterocycles. Synthesis of ethyl 6-methyl-2-oxo-4-{4-[(1-phenyl-1H-1,2,3-triazol-4-yl)methoxy]phenyl}-1,2,3,4-tetrahydropyrimidine-5-carboxylate, identified by our laboratory code LaSOM® 293, was achieved using the Biginelli reaction as the key step, followed by the Huisgen 1,3-dipolar cycloaddition in a convergent four-step route. The product LaSOM® 293 was obtained with a yield of 84%.
Principal Features of Fatigue and Residual Strength of Composite Materials Subjected to Constant Amplitude (CA) Loading
Authors: D’Amore Alberto , Grassia Luigi
Published: August 2019

This paper summarizes the principal features of composites’ responses when subjected to constant amplitude (CA) cyclic loadings. The stochastic nature of the responses; the absence of a detectable fatigue limit; the sudden drop of strength; the general validity of the strength-life equal-rank assumption (SLERA); and, ultimately, the residual strength-life equal-rank assumption (RSLERA) are discussed on the basis of the selected experimental data available in literature. The objective is defining a robust test in order to ascertain the reliability of the phenomenological models. A two-parameter phenomenological model accounting for the maximum cyclic stress, σmax, and the stress ratio, R = σmin/σmax, was used for guidance through the phenomenology of fatigue. It is concluded that the robustness of the models dealing with fatigue can be checked only when the characteristics of the composites’ responses are described simultaneously with fixed parameters.
The Influence of Carbon Nanotubes on the Protective Properties of Polypyrrole Formed at Copper
Authors: Carragher Ursula , Branagan David , Breslin Carmel B.
Published: August 2019

Protective polypyrrole films doped with dodecylbenzene sulfonate (DBS) were formed at copper, while carbon nanotubes (CNT) were incorporated within the polymer films with the DBS to give PPy-DBSCNT (polypyrrole films doped with DBS and incorporated CNT). The polymer films were deposited from a 0.05 M DBS solution at a pH of 6.0 at a thin polypyrrole film doped with tartrate, which served as a stable pre-layer. Low corrosion currents of 0.12 and 0.05 μA cm−2 were estimated using Tafel analysis for the PPy-DBS and PPy-DBSCNT films, respectively, while a significant reduction in the concentration of Cu2+ ions from the corroding copper was observed for the polymer-modified copper. The corrosion protection properties were attributed to the doping of the polymer by the large and immobile DBS anions and possibly, by the larger anionic micelles that are formed at a DBS concentration of 9.8 mM in the pyrrole-containing solution. These dopants give a negatively charged surface that repels chloride anions. The additional protective properties afforded by the CNTs appear to be related to the morphology of the CNT-modified polypyrrole coatings, while the functionalized CNTs also provide a negatively charged surface.
Performance Analysis of Compound Rubber and Steel Slag Filler Modified Asphalt Composite
Authors: Xue Yongjie , Zhao Hui , Wei Xintong , Niu Yunya
Published: August 2019

A new treatment method of combined crumb rubber and steel slag modifier for asphalt binders was proposed in this work. The viscosity, rheological properties, and thermogravimetric analysis of modified asphalt mortar were then investigated. The modified asphalt composite was prepared in laboratory by two steps. Rubber powder was firstly added into hot asphalt flux to make rubber modified asphalt (RA), and then RA binders were wrapped with steel slag powder by granulation machine to make compound rubber and steel slag filler modified asphalt composite (RSAC). Test results showed that the viscosity–temperature susceptibility of RSAC was superior to that of modified asphalt binder with only one additive. The softening point differences of RSAC was 2.1 °C. The complex modulus and phase angle were significantly influenced by the addition of steel slag fillers. Creep tests show that a better anti-permanent deformation performance of RSAC can be obtained, which means a better low temperature performance could be predictable. The CAM (Christensen-Anderson-Marasteanu) and Burgers models can be used to describe the change of complex modulus and viscous-elasticity performance of RSCA. The lower value of me (0.6344) and R (0.1862) from the CAM model indicated that RSAC was slightly related to the sensibility of frequency. The higher value of λ∞ and E0 of RSAC indicated a better ability of shear-creep resistance.
Influence of Morphological Changes in a Source Material on the Growth Interface of 4H-SiC Single Crystals
Authors: Arzig Matthias , Steiner Johannes , Salamon Michael , Uhlmann Norman , Wellmann Peter J.
Published: August 2019

In this study, the change of mass distribution in a source material is tracked using an in situ computer tomography (CT) setup during the bulk growth of 4H- silicon carbide (SiC) via physical vapor depostion (PVT). The changing properties of the source material due to recrystallization and densification are evaluated. Laser flash measurement showed that the thermal properties of different regions of the source material change significantly before and after the growth run. The Si-depleted area at the bottom of the crucible is thermally insulating, while the residual SiC source showed increased thermal conductivity compared to the initially charged powder. Ex situ CT measurements revealed a needle-like structure with elongated pores causing anisotropic behavior for the heat conductivity. Models to assess the thermal conductivity are applied in order to calculate the changes in the temperature field in the crucible and the changes in growth kinetics are discussed.
Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules
Authors: Deng Hua , Yu Hongtao
Published: August 2019

Fluorescence titration of methylene blue, rhodamine B and rhodamine 6G (R6G) by silver nanoparticle (AgNP) all resulted in an initial steep quenching curve followed with a sharp turn and a much flatter quenching curve. At the turn, there are about 200,000 dye molecules per a single AgNP, signifying self-assembly of approximately 36-layers of dye molecules on the surface of the AgNP to form a micelle-like structure. These fluorescence-quenching curves fit to a mathematical model with an exponential term due to molecular self-assembly on AgNP surface, or we termed it “self-assembly shielding effect”, and a Stern-Volmer term (nanoparticle surface enhanced quenching). Such a “super-quenching” by AgNP can only be attributed to “pre-concentration” of the dye molecules on the nanoparticle surface that yields the formation of micelle-like self-assembly, resulting in great fluorescence quenching. Overall, the fluorescence quenching titration reveals three different types of interactions of dye molecules on AgNP surface: 1) self-assembly (methylene blue, rhodamine B and R6G), 2) absorption/tight interaction (tryptamine and fluorescein), and 3) loose interaction (eosin Y). We attribute the formation of micelle-like self-assembly of these three dye molecules on AgNP to their positive charge, possession of nitrogen atoms, and with relatively large and flat aromatic moieties.
Microstructure of Coatings on Nickel and Steel Platelets Obtained by Co-Milling with NiAl and CrB2 Powders
Authors: Szlezynger Maciej , Morgiel Jerzy , Maj Łukasz , Poliarus Olena , Czaja Paweł
Published: August 2019

Metal matrix composite coatings are developed to protect parts made from materials susceptible to wear, like nickel alloys or stainless steel. The industry-established deposition method is presently an atmospheric plasma spraying method since it allows the production of both well-adhering and thick coatings. Alternatively, similar coatings could be produced by co-milling of ceramic and alloyed powders together with metallic plates serving as substrates. It results in mechanical embedding of the powder particles into exposed metallic surfaces required coatings. The present experiment was aimed at the analysis of microstructure of such coatings obtained using NiAl and CrB2 powders. They were loaded together with nickel and stainless steel platelets into ball mill vials and rotated at 350 rpm for up to 32 h. This helped to produce coatings of a thickness up to ~40 µm. The optical, scanning, and transmission electron microscopy observations of the coatings led to conclusion that the higher the rotation speed of vials, the wider the intermixing zone between the coating and the substrate. Simultaneously, it was established that the total thickness of the coating deposited at specified conditions is limited by the brittleness of its nanocrystalline matrix. An increase in the hardness of the substrate results in a decrease of the intermixing zone. The above results indicate that even as the method based on mechanical embedding could so far produce thinner coatings than the plasma spraying, in the former case they are characterized by a more uniform nanocrystalline matrix with homogenously distributed fine ceramic particles.
Environmental Life Cycle Assessment of Thermal Insulation Tiles for Flat Roofs
Authors: Gomes Raul , Silvestre José D. , de Brito Jorge
Published: August 2019

Envelope insulation and protection is an important technical solution to reduce energy consumption, exterior damage, and environmental impacts in buildings. Thermal insulation tiles are used simultaneously as thermal insulation of the building envelope and protection material of under layers in flat roofs systems. The purpose of this research is to assess the environmental impacts of the life cycle of thermal insulation tiles for flat roofs. This research presents the up-to-date “cradle to gate” environmental performance of thermal insulation tiles for the environmental categories and life-cycle stages defined in European standards on environmental evaluation of building. The results presented in this research were based on site-specific data from a Portuguese factory and resulted from a consistent methodology that is here fully described, including the raw materials extraction and production, and the modelling of energy and transport processes at the production stage of thermal insulation tiles. These results reflect the weight of the raw-materials within the production process of thermal insulation tiles in all environmental categories and show that some life cycle stages, such as transportation of raw materials (A2) and packaging and packaging waste (A3.1 and A3.3, respectively), may not be discarded in a cradle to gate study of a construction material because they can make a significant contribution to some environmental categories. Moreover, complementary results regarding the economic, environmental, and energy performance Life Cycle Assessment (LCA) of flat roofs solutions incorporating the thermal insulation tiles studied showed that the influence of the economic costs on the total aggregated costs of these solutions is much higher than that of the environmental costs due to the lower environmental costs of the thermal insulation tiles at the product stage (A1–A3). These costs influenced the corresponding percentage of the environmental costs (between 14% and 18%) and the percentage of the economic costs (between 70% and 75%) in the total aggregated (environmental, economic, and energy) net present value (NPV). Finally, a complementary “cradle to cradle” environmental LCA discussion is presented including the following additional life cycle stages: maintenance and replacement (B2–B4), operational energy use (B6), and end-of-life stage and benefits and loads beyond the system boundary (C1–C4 and D).
Exploiting Reactor Geometry to Manipulate the Properties of Plasma Polymerized Acrylic Acid Films
Authors: Jarvis Karyn , McArthur Sally
Published: August 2019

A number of different reactor geometries can be used to deposit plasma polymer films containing specific functional groups and result in films with differing properties. Plasma polymerization was carried out in a low-pressure custom-built stainless steel T-shaped reactor using a radio frequency generator. The internal aluminium disk electrode was positioned in two different geometries: parallel and perpendicular to the samples at varying distances to demonstrate the effect of varying the electrode position and distance from the electrode on the properties of plasma polymerized acrylic acid (ppAAc) films. The surface chemistry and film thickness before and after aqueous immersion were analysed via X-ray photoelectron spectroscopy and spectroscopic ellipsometry, respectively. For a perpendicular electrode, the ppAAc film thicknesses and aqueous stability decreased while the COOH/R group concentrations increased as the distance from the electrode increased due to decreased fragmentation. For films deposited at similar distances from the electrode, those deposited with the parallel electrode were thicker, had lower COOH/R group concentrations and greater aqueous stability. These results demonstrate the necessity of having a well characterized plasma reactor to enable the deposition of films with specific properties and how reactor geometry can be exploited to tailor film properties.
Effect of Fineness of Basaltic Volcanic Ash on Pozzolanic Reactivity, ASR Expansion and Drying Shrinkage of Blended Cement Mortars
Authors: Khan Kaffayatullah , Amin Muhammad Nasir , Saleem Muhammad Umair , Qureshi Hisham Jahangir , Al-Faiad Majdi Adel , Qadir Muhammad Ghulam
Published: August 2019

This study focuses on evaluating the effect of the fineness of basaltic volcanic ash (VA) on the engineering properties of cement pozzolan mixtures. In this study, VA of two different fineness, i.e., VA fine (VF) and VA ultra-fine (VUF) and commercially available fly ash (FA) was used to partially replace cement. Including a control and a hybrid mix (10% each of VUF and FA), eleven mortar mixes were prepared with various percentages of VA and FA (10%, 20% and 30%) to partially replace cement. First, material characterization was performed by using X-ray florescence (XRF), X-ray powder diffraction (XRD), particle size analysis, and a modified Chappelle test. Then, the compressive strength development, alkali silica reactivity (ASR), and drying shrinkage of all mortar mixes were investigated. Finally, XRD analysis on paste samples of all mixes was performed to assess their pozzolanic reactivity at ages of 7 and 91 days. The results showed increased Chappelle reactivity values with an increase in the fineness of the VA. Mortars containing high percentages of VUF (20% and 30%) showed almost equal compressive strength compared to corresponding FA mortars at all ages, however, the hybrid mix (10% VUF + 10% FA) exhibited higher strength than that of the reference mix (100% cement), particularly, at 91 days. At low percentages (10%), ASR expansion in both VF and VUF mortars was higher compared to the corresponding FA mortar and the opposite behavior was observed at high percentages (20% and 30%). Among all the mixes including the control, mortar with VUF was found to be most effective in controlling drying shrinkages at all ages. The rate of consumption of calcium hydroxide (Ca(OH)2) for pastes containing VUF and FA was almost the same, while VF showed low Ca(OH)2 intensity. These results indicate that an increase in the fineness of VA significantly improvs performance, and therefore, it could be a feasible substitute for commercial admixtures in cement composites.