bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Modelling of Ice-Covered Insulator Flashover: The Influence of Arc Velocity and Arc Propagation Criteria
Authors: Jabbari Marouane , Volat Christophe , Fofana Issouf
Published: October 2018

This paper investigates the influence of arc velocity and propagation criteria on the parameters of a dynamic numerical mono-arc model used to predict flashover voltage of ice-covered insulators. For that purpose, a generic algorithm has been developed which, coupled with a Finite Element commercial software, permits us to solve the mono-arc Obenaus equation. The versatility of the proposed algorithm allows to implement three different arc propagation criteria and five different arc velocity criteria, as well as to compute the corresponding flashover voltage, arc velocity and leakage current. Moreover, this algorithm permits to propose a new arc velocity criterion based on numerical calculation instead of analytical formulation as proposed in literature.
Fracture Characteristics and Their Influence on Gas Seepage in Tight Gas Reservoirs in the Kelasu Thrust Belt (Kuqa Depression, NW China)
Authors: Dong Yue , Lu Xuesong , Fan Junjia , Zhuo Qingong
Published: October 2018

Natural fractures were generally accepted as a key factor influencing the gas seepage performance in tight gas reservoirs in Kelasu Thrust Belt (KTB). However, the mechanism was not fully clarified, especially from a microscopic perspective. Based on observation of core samples and cast thin sections and gas charging experiment on core plugs, the parameters of fractures and seepage performance in fractured tight reservoirs are studied; further, the controlling effect of fractures on gas seepage was discussed. The results show that in KTB fractures could be categorized by the size of their apertures as macro-fractures (aperture width ranges from 0.1 to 2 mm) and micro-fractures (aperture width ranges from 5 to 100 μm), which appear in the form of fractures networks. Tectonic deformations and abnormal high fluid pressure control the fracture density: near faults or anticlines (folds), fracture density increases, and fluid pressure of 15 MPa increases the aperture by 50%, and induces new fractures. The fracture networks with high linear density significantly improves tight reservoir quality and seepage performance: it enhances the reservoir permeability by 1–4 orders of magnitude, and the relative gas permeability by 2–10 magnitude; by enhancing permeability, the fracture networks reduce the initial flowing gradient from as high as 0.41 MPa/cm to 0 Mpa/cm, and make the gas flowing possible.
Experimental Study on the Performance of a Household Dual-Source Heat Pump Water Heater
Authors: Gou Xiang , Liu Shian , Fu Yang , Zhang Qiyan , Iram Saima , Liu Yingfan
Published: October 2018

A household dual source heat pump water heater is proposed to utilize the energy of wastewater and air heat in a bathroom. The heat pump system integrates a wastewater source heat pump (WSHP), air source heat pump (ASHP), and a preheater. This aims at energy saving through recovering the heat of wastewater and ventilation air during the bathing process. The experiment was conducted to verify the feasibility of a dual heat source heat pump water heater system in a bath unit. It is found that the system can achieve an average coefficient of performance (COP) of 4.80 and 4.38 with and without preheater, respectively. At a bath water temperature of 40 °C, a flow rate of 6 L/min, and a room temperature of 26.5 °C, the COP of system can reach 6.08, which shows a significantly promising method for energy saving in-house.
Circular Statistics Applied to the Study of the Solar Radiation Potential of Rooftops in a Medium-Sized City
Authors: Polo María-Eugenia , Pozo Mar , Quirós Elia
Published: October 2018

Solar energy constitutes one of the most effective alternative energy sources for combating climate change. However, the solar potential in a city can vary depending on the urban morphology. The purpose of this paper is to perform a directional statistical analysis of the distribution of the monthly solar potential of rooftops in the city of Cáceres, Spain, in relation to the orientations and slopes of the rooftops. Two residential areas, one in the city center and one on the outskirts of the city, and an industrial zone, all of which exhibit different urban morphologies, have been evaluated. Statistics have been assessed in consideration of the orientation and slope values of the rooftops as circular data, and the radiation values as linear data. The three dissimilar urban morphologies result in different solar potential values, and the monthly disaggregation of the data enables the ability to detect the differences existing in the solar potential between each zone, during each month. The proposed analysis could also be extrapolated to urban planning for the design of more sustainable cities to face the challenges associated with climate change.
Improved Boiler-Turbine Coordinated Control of CHP Units with Heat Accumulators by Introducing Heat Source Regulation
Authors: Wang Wei , Sun Yang , Jing Sitong , Zhang Wenguang , Cui Can
Published: October 2018

It is significant for power system stability to improve the operation flexibility of grid-connected units. Such improvement has always been a hot topic, especially for coal-fired units. In recent decades, it has become increasingly urgent and challenging as large-scale fluctuant renewable energy is connected to the power grid. Boiler-turbine coordinated control strategy (CCS), which is employed to perform unit load control according to automatic generation control (AGC), has a slow ramp rate in general on account of large delay and inertia of boiler, so to improve the unit operating flexibility, it is necessary to explore usable heat storage and optimize the control strategy. In combined heat and power (CHP) units with heat accumulators, their heat and power are decoupled. Therefore the extraction steam that goes to the heating station can be regulated flexibly even operating in “heat-led mode”. The change of extraction steam flow has a significant influence on the turbine power output, so we propose to improve the load-following capability of CHP units by regulating the heat source flow. In this paper, the influencing model is set up, and it is about heat source flow variations on the electric power output. The load control strategy is further optimized and designed through combinations of CCS and heat source regulation. Finally simulations and analysis are performed on a 330MW CHP unit, and the results reveal that the power ramp rate with our strategy is two times faster than that with traditional strategy.
Climate Sensitivity of Tropical Trees Along an Elevation Gradient in Rwanda
Authors: Mujawamariya Myriam , Manishimwe Aloysie , Ntirugulirwa Bonaventure , Zibera Etienne , Ganszky Daniel , Ntawuhiganayo Bahati Elisée , Nyirambangutse Brigitte , Nsabimana Donat , Wallin Göran , Uddling Johan
Published: October 2018

Elevation gradients offer excellent opportunities to explore the climate sensitivity of vegetation. Here, we investigated elevation patterns of structural, chemical, and physiological traits in tropical tree species along a 1700–2700 m elevation gradient in Rwanda, central Africa. Two early-successional (Polyscias fulva, Macaranga kilimandscharica) and two late-successional (Syzygium guineense, Carapa grandiflora) species that are abundant in the area and present along the entire gradient were investigated. We found that elevation patterns in leaf stomatal conductance (gs), transpiration (E), net photosynthesis (An), and water-use efficiency were highly season-dependent. In the wet season, there was no clear variation in gs or An with elevation, while E was lower at cooler high-elevation sites. In the dry season, gs, An, and E were all lower at drier low elevation sites. The leaf-to-air temperature difference was smallest in P. fulva, which also had the highest gs and E. Water-use efficiency (An/E) increased with elevation in the wet season, but not in the dry season. Leaf nutrient ratios indicated that trees at all sites are mostly P limited and the N:P ratio did not decrease with increasing elevation. Our finding of strongly decreased gas exchange at lower sites in the dry season suggests that both transpiration and primary production would decline in a climate with more pronounced dry periods. Furthermore, we showed that N limitation does not increase with elevation in the forests studied, as otherwise most commonly reported for tropical montane forests.
Genomic Insights into Date Palm Origins
Authors: Gros-Balthazard Muriel , Hazzouri Khaled Michel , Flowers Jonathan Mark
Published: October 2018

With the development of next-generation sequencing technology, the amount of date palm (Phoenix dactylifera L.) genomic data has grown rapidly and yielded new insights into this species and its origins. Here, we review advances in understanding of the evolutionary history of the date palm, with a particular emphasis on what has been learned from the analysis of genomic data. We first record current genomic resources available for date palm including genome assemblies and resequencing data. We discuss new insights into its domestication and diversification history based on these improved genomic resources. We further report recent discoveries such as the existence of wild ancestral populations in remote locations of Oman and high differentiation between African and Middle Eastern populations. While genomic data are consistent with the view that domestication took place in the Gulf region, they suggest that the process was more complex involving multiple gene pools and possibly a secondary domestication. Many questions remain unanswered, especially regarding the genetic architecture of domestication and diversification. We provide a road map to future studies that will further clarify the domestication history of this iconic crop.
The Complete Plastome Sequences of Eleven Capsicum Genotypes: Insights into DNA Variation and Molecular Evolution
Authors: D’Agostino Nunzio , Tamburino Rachele , Cantarella Concita , De Carluccio Valentina , Sannino Lorenza , Cozzolino Salvatore , Cardi Teodoro , Scotti Nunzia
Published: October 2018

Members of the genus Capsicum are of great economic importance, including both wild forms and cultivars of peppers and chilies. The high number of potentially informative characteristics that can be identified through next-generation sequencing technologies gave a huge boost to evolutionary and comparative genomic research in higher plants. Here, we determined the complete nucleotide sequences of the plastomes of eight Capsicum species (eleven genotypes), representing the three main taxonomic groups in the genus and estimated molecular diversity. Comparative analyses highlighted a wide spectrum of variation, ranging from point mutations to small/medium size insertions/deletions (InDels), with accD, ndhB, rpl20, ycf1, and ycf2 being the most variable genes. The global pattern of sequence variation is consistent with the phylogenetic signal. Maximum-likelihood tree estimation revealed that Capsicum chacoense is sister to the baccatum complex. Divergence and positive selection analyses unveiled that protein-coding genes were generally well conserved, but we identified 25 positive signatures distributed in six genes involved in different essential plastid functions, suggesting positive selection during evolution of Capsicum plastomes. Finally, the identified sequence variation allowed us to develop simple PCR-based markers useful in future work to discriminate species belonging to different Capsicum complexes.
B Chromosomes in Grasshoppers: Different Origins and Pathways to the Modern Bs
Authors: Jetybayev Ilyas , Bugrov Alexander , Dzuybenko Victoria , Rubtsov Nikolay
Published: October 2018

B chromosomes (Bs) were described in most taxa of eukaryotes and in around 11.9% of studied Orthopteran species. In some grasshopper species, their evolution has led to many B chromosome morphotypes. We studied the Bs in nine species (Nocaracris tardus, Nocaracris cyanipes, Aeropus sibiricus, Chorthippus jacobsoni, Chorthippus apricarius, Bryodema gebleri, Asiotmethis heptapotamicus songoricus, Podisma sapporensis, and Eyprepocnemis plorans), analyzing their possible origin and further development. The studied Bs consisted of C-positive or C-positive and C-negative regions. Analyzing new data and considering current hypotheses, we suggest that Bs in grasshoppers could arise through different mechanisms and from different chromosomes of the main set. We gave our special attention to the Bs with C-negative regions and suggest a new hypothesis of B chromosome formation from large or medium autosomes. This hypothesis includes dissemination of repetitive sequences and development of intercalary heterochromatic blocks in euchromatic chromosome arm followed by deletion of euchromatic regions located between them. The hypothesis is based on the findings of the Eyprepocnemis plorans specimens with autosome containing numerous intercalary repeat clusters, analysis of C-positive Bs in Eyprepocnemis plorans and Podisma sapporensis containing intercalary and terminal C-negative regions, and development of heterochromatic neo-Y chromosome in some Pamphagidae grasshoppers.
Performing Devotion: Belief, the Body, and the Book of Common Prayer 1775–1840
Authors: Davies Laura
Published: October 2018

This article examines three texts published between 1775 and 1840 that attempt to model an ideal reading of the Anglican liturgy and to render it on the printed page, exploring the ways in which elocutionary instruction, acting theory and accounts of public worship intersect within them through the figures of inscription and incorporation. Reflecting on the choice of the famous actor David Garrick as an exemplary reader in the two later texts, and drawing on the work of Jacques Derrida and Judith Butler, it discusses how and why these texts attempt to regulate competing ideas regarding the concepts of performance, embodiment, and assembly. The argument is made that although prescriptive in their demands, to varying degrees these texts acknowledge their own insufficiencies, and recognise not merely the difficulty of the task of transposing oral performance to a series of textual signs, or of accounting for the nature of devout worship, but also a more fundamental excess and irreducibility in the constitution of the self.
Monthly Analysis of Wetlands Dynamics Using Remote Sensing Data
Authors: Kaplan Gordana , Avdan Ugur
Published: October 2018

As wetlands are one of the world’s most important ecosystems, their vulnerability necessitates the constant monitoring and mapping of their changes. Satellite-based remote sensing has become an essential data source for mapping and monitoring wetlands. As wetlands are dynamic ecosystems, their classification depends on many different parameters. However, considering their complex structure; wetlands tend to be challenging land cover for classification, which sometimes requires the use of multi-sensor remote sensing techniques. The objectives of this study were: (i) to investigate the monthly dynamics of several wetland classes using multi-sensor parameters; (ii) to find correlations between the investigated parameters. Thus, we extracted the Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) from Landsat 8, and extracted dual polarization backscatter values (VH-VV) from the Sentinel-1 satellite at a monthly period over a year. The results showed strong correlation between the LST and the NDVI values of 0.94, and strong correlation between the microwave (VH) and both thermal and optical parameters with a 0.81 correlation coefficient, while there was weak or no correlation between the VV and the other investigated parameters. We strongly recommend that future studies clarify the Sentinel-1 backscatter values in wetland areas, by taking multiple field measurements close to the image acquisition time.
Plant Hormone Signaling Crosstalks between Biotic and Abiotic Stress Responses
Authors: Ku Yee-Shan , Sintaha Mariz , Cheung Ming-Yan , Lam Hon-Ming
Published: October 2018

In the natural environment, plants are often bombarded by a combination of abiotic (such as drought, salt, heat or cold) and biotic (necrotrophic and biotrophic pathogens) stresses simultaneously. It is critical to understand how the various response pathways to these stresses interact with one another within the plants, and where the points of crosstalk occur which switch the responses from one pathway to another. Calcium sensors are often regarded as the first line of response to external stimuli to trigger downstream signaling. Abscisic acid (ABA) is a major phytohormone regulating stress responses, and it interacts with the jasmonic acid (JA) and salicylic acid (SA) signaling pathways to channel resources into mitigating the effects of abiotic stresses versus defending against pathogens. The signal transduction in these pathways are often carried out via GTP-binding proteins (G-proteins) which comprise of a large group of proteins that are varied in structures and functions. Deciphering the combined actions of these different signaling pathways in plants would greatly enhance the ability of breeders to develop food crops that can thrive in deteriorating environmental conditions under climate change, and that can maintain or even increase crop yield.
Differences in Interleukin-8 Plasma Levels between Diabetic Patients and Healthy Individuals Independently on Their Periodontal Status
Authors: Borilova Linhartova Petra , Kavrikova Denisa , Tomandlova Marie , Poskerova Hana , Rehka Vaclav , Dušek Ladislav , Izakovicova Holla Lydie
Published: October 2018

Chronic periodontitis (CP) and diabetes mellitus (DM) involve several aspects of immune functions, including neutrophil activity and cytokine biology. Considering the critical function of chemokine interleukin-8 (IL-8) in the inflammatory process, the aims of this study were to determine: (i) IL-8 plasma levels; (ii) IL-8 (−251A/T, rs4073) and its receptor 2 (CXCR2, +1208C/T, rs1126579) polymorphisms, and (iii) the presence of the selected periodontal bacteria in types 1 and 2 DM patients (T1DM and T2DM) and systemically healthy controls (HC) with known periodontal status. This case–control study comprises of 153 unrelated individuals: 36/44 patients suffering from T1DM+CP/T2DM+CP and 32/41 from HC+CP/non-periodontitis HC. Both the clinical and biochemical parameters were monitored. The genotypes were determined using qPCR, IL-8 plasma levels were measured using an ELISA kit. Subgingival bacterial colonization was analyzed with a DNA microarray detection kit. The IL-8 plasma levels differed significantly between non-periodontitis HC and T1DM+CP/T2DM+CP patients (P < 0.01). Even in HC+CP, IL-8 concentrations were significantly lower than in T1DM+CP/T2DM+CP patients (P ≤ 0.05). No significant associations between the IL-8 plasma levels and the studied IL-8 and CXCR2 polymorphisms or the occurrence of selected periodontal bacteria (P > 0.05) were found. CP does not influence the circulating IL-8 levels. Patients with T1DM+CP/T2DM+CP had higher circulating IL-8 levels than HC+CP/non-periodontitis HC.
Peanut Stunt Virus and Its Satellite RNA Trigger Changes in Phosphorylation in N. benthamiana Infected Plants at the Early Stage of the Infection
Authors: Wrzesińska Barbara , Dai Vu Lam , Gevaert Kris , De Smet Ive , Obrępalska-Stęplowska Aleksandra
Published: October 2018

Signaling in host plants is an integral part of a successful infection by pathogenic RNA viruses. Therefore, identifying early signaling events in host plants that play an important role in establishing the infection process will help our understanding of the disease process. In this context, phosphorylation constitutes one of the most important post-translational protein modifications, regulating many cellular signaling processes. In this study, we aimed to identify the processes affected by infection with Peanut stunt virus (PSV) and its satellite RNA (satRNA) in Nicotiana benthamiana at the early stage of pathogenesis. To achieve this, we performed proteome and phosphoproteome analyses on plants treated with PSV and its satRNA. The analysis of the number of differentially phosphorylated proteins showed strong down-regulation in phosphorylation in virus-treated plants (without satRNA). Moreover, proteome analysis revealed more down-regulated proteins in PSV and satRNA-treated plants, which indicated a complex dependence between proteins and their modifications. Apart from changes in photosynthesis and carbon metabolism, which are usually observed in virus-infected plants, alterations in proteins involved in RNA synthesis, transport, and turnover were observed. As a whole, this is the first community (phospho)proteome resource upon infection of N. benthamiana with a cucumovirus and its satRNA and this resource constitutes a valuable data set for future studies.
Comparative Proteomic and Physiological Analyses of Two Divergent Maize Inbred Lines Provide More Insights into Drought-Stress Tolerance Mechanisms
Authors: Zenda Tinashe , Liu Songtao , Wang Xuan , Jin Hongyu , Liu Guo , Duan Huijun
Published: October 2018

Drought stress is the major abiotic factor threatening maize (Zea mays L.) yield globally. Therefore, revealing the molecular mechanisms fundamental to drought tolerance in maize becomes imperative. Herein, we conducted a comprehensive comparative analysis of two maize inbred lines contrasting in drought stress tolerance based on their physiological and proteomic responses at the seedling stage. Our observations showed that divergent stress tolerance mechanisms exist between the two inbred-lines at physiological and proteomic levels, with YE8112 being comparatively more tolerant than MO17 owing to its maintenance of higher relative leaf water and proline contents, greater increase in peroxidase (POD) activity, along with decreased level of lipid peroxidation under stressed conditions. Using an iTRAQ (isobaric tags for relative and absolute quantification)-based method, we identified a total of 721 differentially abundant proteins (DAPs). Amongst these, we fished out five essential sets of drought responsive DAPs, including 13 DAPs specific to YE8112, 107 specific DAPs shared between drought-sensitive and drought-tolerant lines after drought treatment (SD_TD), three DAPs of YE8112 also regulated in SD_TD, 84 DAPs unique to MO17, and five overlapping DAPs between the two inbred lines. The most significantly enriched DAPs in YE8112 were associated with the photosynthesis antenna proteins pathway, whilst those in MO17 were related to C5-branched dibasic acid metabolism and RNA transport pathways. The changes in protein abundance were consistent with the observed physiological characterizations of the two inbred lines. Further, quantitative real-time polymerase chain reaction (qRT-PCR) analysis results confirmed the iTRAQ sequencing data. The higher drought tolerance of YE8112 was attributed to: activation of photosynthesis proteins involved in balancing light capture and utilization; enhanced lipid-metabolism; development of abiotic and biotic cross-tolerance mechanisms; increased cellular detoxification capacity; activation of chaperones that stabilize other proteins against drought-induced denaturation; and reduced synthesis of redundant proteins to help save energy to battle drought stress. These findings provide further insights into the molecular signatures underpinning maize drought stress tolerance.
Improvement of Fast Simplified Successive-Cancellation Decoder for Polar Codes
Authors: Xing Chao , Huang Zhiliang , Zhao Shengmei
Published: October 2018

This paper presents a new latency reduction method for successive-cancellation (SC) decoding of polar codes that performs a frozen-bit checking on the rate-other (R-other) nodes of the Fast Simplified SC (Fast-SSC) pruning tree. The proposed method integrates the Fast-SSC algorithm and the Improved SSC method (frozen-bit checking of the R-other nodes). We apply a recognition-based method to search for as many constituent codes as possible in the decoding tree offline. During decoding, the current node can be decoded directly, if it is a special constituent code; otherwise, the frozen-bit check is executed. If the frozen-bit check condition is satisfied, the operation of the R-other node is the same as that of the rate-one node. In this paper, we prove that the frame error rate (FER) performance of the proposed algorithm is consistent with that of the original SC algorithm. Simulation results show that the proportion of R-other nodes that satisfy the frozen-bit check condition increases with the signal-to-noise-ratio (SNR). Importantly, our proposed method yields a significant reduction in latency compared to those given by existing latency reduction methods. The proposed method solves the problem of high latency for the Improved-SSC method at a high code rate and low SNR, simultaneously.
Hotels as Critical Hubs for Destination Disaster Resilience: An Analysis of Hotel Corporations’ CSR Activities Supporting Disaster Relief and Resilience
Authors: Dobie Sarah , Schneider Jennifer , Kesgin Muhammet , Lagiewski Rick
Published: October 2018

Disaster management has begun to examine the unique role of the private sector in disaster relief. The hotel and lodging industry is an especially critical infrastructure for community disaster relief and resilience, providing many lifeline services in addition to core skills and competencies contributing to the community’s social and human capital. Social and human capital empower the community to better cope with disturbance, and companies’ efforts to build social and human capital are often tied to their corporate social responsibility (CSR) management systems. A framework was developed to evaluate the management system maturity of the hotel and lodging industry’s CSR management for disaster relief and resilience. An analysis of three hotel and lodging corporations was performed to understand the current state of the industry. While many hotel properties are engaging in CSR activities during disaster relief, the analysis revealed that corporate management systems have room for maturation and growth to support the resilience of their community.
Hysterectomies Are Associated with an Increased Risk of Depression: A Population-Based Cohort Study
Authors: Harnod Tomor , Chen Weishan , Wang Jen-Hung , Lin Shinn-Zong , Ding Dah-Ching
Published: October 2018

Using the National Health Insurance Research Database of Taiwan, we investigated whether undergoing a hysterectomy increases the risk of depression. A total of 7872 patients aged 30–49 years who underwent a hysterectomy from 2000 to 2013 were enrolled as the hysterectomy group. The comparison group was randomly selected from women who had never undergone a hysterectomy and was four times the size of the hysterectomy group. We calculated adjusted hazard ratios and 95% confidence intervals (CIs) for depression [The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes 296.2, 296.3, 300.4, 311] in these cohorts after adjusting for age, comorbidities, oophorectomy, and hormone therapy. The overall incidence of depression was 1.02 and 0.66 per 100 person-years in the hysterectomy and comparison cohorts, respectively, yielding an adjusted hazard ratio of 1.35 (95% CI = 1.22–1.50) for depression risk. When we stratified patients by age, comorbidities, oophorectomy, and hormone use, hysterectomy increased the risk of depression. Hysterectomy, oophorectomy, and post-surgery hormone use were associated with an increased risk of depression when they occurred alone, but conferred a greater risk if they were considered jointly. Hysterectomy would be a predisposing factor for increased risk of subsequent depression. Our findings provide vital information for patients, clinicians, and the government for improving the treatment strategy in the future.
Signed Real-Time Delay Multiply and Sum Beamforming for Multispectral Photoacoustic Imaging
Authors: Kirchner Thomas , Sattler Franz , Gröhl Janek , Maier-Hein Lena
Published: October 2018

Reconstruction of photoacoustic (PA) images acquired with clinical ultrasound transducers is usually performed using the Delay and Sum (DAS) beamforming algorithm. Recently, a variant of DAS, referred to as Delay Multiply and Sum (DMAS) beamforming has been shown to provide increased contrast, signal-to-noise ratio (SNR) and resolution in PA imaging. The main reasons for the use of DAS beamforming in photoacoustics are its simple implementation, real-time capability, and the linearity of the beamformed image to the PA signal. This is crucial for the identification of different chromophores in multispectral PA applications. In contrast, current DMAS implementations are not responsive to the full spectrum of sound frequencies from a photoacoustic source and have not been shown to provide a reconstruction linear to the PA signal. Furthermore, due to its increased computational complexity, DMAS has not been shown yet to work in real-time. Here, we present an open-source real-time variant of the DMAS algorithm, signed DMAS (sDMAS), that ensures linearity in the original PA signal response while providing the increased image quality of DMAS. We show the applicability of sDMAS for multispectral PA applications, in vitro and in vivo. The sDMAS and reference DAS algorithms were integrated in the open-source Medical Imaging Interaction Toolkit (MITK) and are available as real-time capable implementations.
Properties of Novel Non-Silicon Materials for Photovoltaic Applications: A First-Principle Insight
Authors: Rasukkannu Murugesan , Velauthapillai Dhayalan , Bianchini Federico , Vajeeston Ponniah
Published: October 2018

Due to the low absorption coefficients of crystalline silicon-based solar cells, researchers have focused on non-silicon semiconductors with direct band gaps for the development of novel photovoltaic devices. In this study, we use density functional theory to model the electronic structure of a large database of candidates to identify materials with ideal properties for photovoltaic applications. The first screening is operated at the GGA level to select only materials with a sufficiently small direct band gap. We extracted twenty-seven candidates from an initial population of thousands, exhibiting GGA band gap in the range 0.5–1 eV. More accurate calculations using a hybrid functional were performed on this subset. Based on this, we present a detailed first-principle investigation of the four optimal compounds, namely, TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO. The direct band gap of these materials is between 1.1 and 2.26 eV. In the visible region, the absorption peaks that appear in the optical spectra for these compounds indicate high absorption intensity. Furthermore, we have investigated the structural and mechanical stability of these compounds and calculated electron effective masses. Based on in-depth analysis, we have identified TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO as very promising candidates for photovoltaic applications.
Influence of Implant Neck Design on Peri-Implant Tissue Dimensions: A Comparative Study in Dogs
Authors: Calvo-Guirado José Luis , Jiménez-Soto Raúl , Pérez Albacete-Martínez Carlos , Fernández-Domínguez Manuel , Gehrke Sérgio Alexandre , Maté-Sánchez de Val José Eduardo
Published: October 2018

This in vivo study assessed (hard and soft) peri-implant tissue remodeling around implants with micro-ring and open-thread neck designs placed in a dog model. Twenty histological sections corresponding to four different implant designs that were placed in America Foxhound dogs were obtained from previous studies. All the implants had been placed under identical conditions and were divided into four groups: Group A, micro-rings on implant neck plus 0.5 mm refined surface; Group B, micro-rings on implant neck; Group C, open-thread neck; and, Group D, double-spiral neck. Eight weeks after surgery, the integrated implants were removed and processed for histological examination. Crestal bone loss and bone-to-implant contact was greater for micro-ring necks than open-thread necks. Soft tissues showed significant differences on both buccal and lingual aspects, so that the distance from peri-implant mucosa to the apical portion of the barrier epithelium was smaller in the micro-ring groups. So, in spite of generating greater bone-to-implant contact, implants with micro rings produced more bone loss than open-thread implants. Moreover, the outcomes that were obtained IPX implants smooth neck design produced less bone loss in the cervical area, following by Facility implants when compared with the other open thread and microthreaded implant designs. Implant thread design can influence on bone remodeling in the cervical area, related to bundle bone preservation.
Fabrication of Bifunctional Chitosan-Based Flocculants: Characterization, Assessment of Flocculation, and Sterilization Performance
Authors: Wang Moxi , Feng Li , Fan Xiaowei , Li Dongmei , Qu Wenqi , Jiang Shuxian , Li Shaoxiu
Published: October 2018

In this study, a series of chitosan-based quaternary ammonium graft flocculants, namely chitosan-graft-poly(acrylamide and methacryloyl ethyl trimethyl ammonium chloride) [CTS-g-P(AM-DMC)], was successfully synthesized by plasma initiation, and the as-prepared [CTS-g-P(AM-DMC)] had both flocculation and sterilization functions. Various characterization techniques were used to study the structure and physicochemical properties of the chitosan-based flocculants. 1H nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and thermogravimetric analysis/differential scanning calorimetry (TG/DSC) confirmed the successful synthesis of CTS-g-P(AM-DMC). Scanning electron microscopy (SEM) analysis exhibited that CTS-g-P(AM-DMC) contained a smooth convex and porous structure with an enormous surface area. CTS-g-P(AM-DMC) was then used to flocculate the simulated wastewater of the kaolin suspension and the Salmonella suspension. Besides external factors, such as the dosage of flocculant and pH, the effect of the internal factor graft ratio was also evaluated. The experimental results showed that CTS-g-P(AM-DMC) also revealed a strong sterilization effect, aside from the excellent flocculation effect. Moreover, the sterilization mechanism was investigated through a series of conductivity measurements and the analysis of fluorescence-based cell live/dead tests. The results indicated that CTS-g-P(AM-DMC) destroyed the cell membrane of Salmonella through its grafted quaternary ammonium salt, thereby exhibiting sterilization property.
A Unique Strategy for Polyethylene Glycol/Hybrid Carbon Foam Phase Change Materials: Morphologies, Thermal Properties, and Energy Storage Behavior
Authors: Su Xiaolong , Jia Shikui , Lv Guowei , Yu Demei
Published: October 2018

Polyethylene glycol (PEG)/hybrid carbon foam (CF) phase change materials (PCMs) were prepared by integrating PEG into CF via dynamic-vacuum impregnation. The hybrid CF was first synthesized by mixtures of graphene oxide (GO) and carbon nanotubes (CNTs) with different volume ratios. The morphologies, chemical structures, thermal conductivities, shape-stabilization levels, and photo-thermal energy conversion levels of these composite PCMs were characterized systematically. The prepared composite PCMs exhibited good shape-stabilization levels and showed their original shapes without any PEG leakage. It was found that the polyethylene glycol/carbon foam with multi-walled carbon nanotubes (PEG/MCF) composite PCMs had a better shape-stable performance below the temperature of 250 °C, and the thermal conductivity of the PEG/MCF composite PCMs reached as high as 1.535 W/(mK), which was obviously higher than that of polyethylene glycol/carbon foam with single-walled carbon nanotubes (PEG/SCF, 1.159 W/(mK)). The results of the photo-thermal simulation tests showed that the composite PCMs had the ability to absorb light energy and then convert it to thermal energy, and the maximum thermal energy storage efficiency of the PEG/MCF composite PCMs and the PEG/SCF composite PCMs was 92.1% and 90.6%, respectively. It was considered that a valuable technique to produce high-performance composite PCMs was developed.
Anhysteretic Magnetization Measurement Methods for Soft Magnetic Materials
Authors: Nowicki Michał
Published: October 2018

This article is concerned with the methods for experimentally determining the Anhysteretic Magnetization curve for soft magnetic materials. A new method based on the modern hysteresisgraph system is presented. Known modern and traditional methods based on fluxmeters are presented as well. The experimental results obtained with the described methods for isotropic Mn–Zn ferrite are compared. Lastly, results of validation on NANOPERM® nanocrystalline material are detailed and show negligible hysteresis. The new method allows for accurate Anhysteretic Magnetization curve measurement without software or hardware modifications of standard, commercially available hysteresisgraph systems. The speed and accuracy of the results are improved in comparison with other methods.
1H NMR Spectroscopy and MVA to Evaluate the Effects of Caulerpin-Based Diet on Diplodus sargus Lipid Profiles
Authors: Del Coco Laura , Felline Serena , Girelli Chiara Roberta , Angilè Federica , Magliozzi Laura , Almada Frederico , D’Aniello Biagio , Mollo Ernesto , Terlizzi Antonio , Fanizzi Francesco P.
Published: October 2018

The biological invasion of the green algae Caulerpa cylindracea represents a serious scientific and public issue in the Mediterranean Sea, essentially due to strong modifications both to habitat structure and native benthic communities. Although alterations in health status and changes in flesh quality of some marine species (dietary exposed to C. cylindracea) have been observed, no studies on cause-effect relationships have been carried out. Here, for the first time, through a controlled feeding experiment followed by 1H NMR Spectroscopy and multivariate analysis (PCA, OPLS-DA), we showed that caulerpin taken with diet is directly responsible of changes observed in metabolic profile of fish flesh, including alteration of lipid metabolism, in particular with a reduction of ω3 PUFA content. The potential of caulerpin to directly modulate lipid metabolism opens up new questions about causal mechanism triggered by algal metabolite also in view of a possible exploitation in the nutraceutical/medical field.
Leaky Gut, Leaky Brain?
Authors: Obrenovich Mark E. M.
Published: October 2018

‘Leaky gut’ syndrome, long-associated with celiac disease, has attracted much attention in recent years and for decades, was widely known in complementary/alternative medicine circles. It is often described as an increase in the permeability of the intestinal mucosa, which could allow bacteria, toxic digestive metabolites, bacterial toxins, and small molecules to ‘leak’ into the bloodstream. Nervous system involvement with celiac disease is know to occur even at subclinical levels. Gluten and gluten sensitivity are considered to trigger this syndrome in individuals genetically predisposed to celiac disease. However, the incidence of celiac disease in the general population is quite low. Nevertheless, increased public interest in gluten sensitivity has contributed to expanded food labels stating ‘gluten-free’ and the proliferation of gluten-free products, which further drives gluten-free lifestyle changes by individuals without frank celiac disease. Moreover, systemic inflammation is associated with celiac disease, depression, and psychiatric comorbidities. This mini-review focuses on the possible neurophysiological basis of leaky gut; leaky brain disease; and the microbiota’s contribution to inflammation, gastrointestinal, and blood-brain barrier integrity, in order to build a case for possible mechanisms that could foster further ‘leaky’ syndromes. We ask whether a gluten-free diet is important for anyone or only those with celiac disease.
Compositional and Textural Variations in Hainite-(Y) and Batievaite-(Y), Two Rinkite-Group Minerals from the Sakharjok Massif, Keivy Alkaline Province, NW Russia
Authors: Selivanova Ekaterina A. , Lyalina Lyudmila M. , Savchenko Yevgeny E.
Published: October 2018

Compositional and textural variations in the rinkite group, seidozerite supergroup minerals, batievaite-(Y), hainite-(Y) and close to them titanosilicates from the Sakharjok massif were studied. Statistical analysis allowed for defining two major substitution schemes leading to batievaite-(Y) and cation-deficient titanosilicates forming: Ca2+ + Na+ + F− ↔ □ + Y3+ + (OH)− and Ca2+ + Na+ ↔ □ + REE3+. Batievaite-(Y) and other cation-deficient titanosilicates are the earlier minerals formed by solid state transformation of the primary full-cation phase. Hainite-(Y) is a later mineral. It forms rims around earlier titanosilicates, or, less often, separate crystals.
Multi-Analytical Investigation of Stains on Dimension Stones in Master Valentim’s Fountain, Brazil
Authors: Da Conceição Ribeiro Roberto Carlos , Marques Ferreira de Figueiredo Patrícia , Silva Barbutti Daniel
Published: October 2018

Master Valentim’s fountain has become an important historical patrimony for Brazil, being portrayed by famous artists, among them Jean-Baptiste Debret. In 1938, it was registered as cultural heritage by the Brazilian National Historical and Artistic Heritage Institute (IPHAN), and in 1990 it was subjected to excavation and restoration works. The fountain was built in Gneiss and Lioz limestone, with metallic plates and mortar connecting the Gneiss blocks. Currently, deteriorations in the fountain stones can be observed, such as light stains and some aesthetic modifications caused by inadequate restorations. Petrography, X-ray fluorescence (XRF), XRD, physical properties, colorimetry, electrical conductivity, inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and TGA were performed in order to characterize the Gneiss blocks, the metallic plates, and the stones used in previous restorations, as well as light stains observed on the Gneiss blocks. The petrography and XRD analyses inferred that the light stains may have been caused by the formation of an insoluble salt as a result of the association of the lead from the plates with other elements. The XRD analysis on the light staining area indicated the presence of cerussite (PbCO3) and anglesite (PbSO4), which are the probable cause of the light stains. The SEM-EDX results suggested that sulfur is the main element associated to lead.
Effects of Different Cultivation Parameters on the Production of Surfactin Variants by a Bacillus subtilis Strain
Authors: Bartal Attila , Vigneshwari Aruna , Bóka Bettina , Vörös Mónika , Takács István , Kredics László , Manczinger László , Varga Mónika , Vágvölgyi Csaba , Szekeres András
Published: October 2018

Surfactins are lipopeptide-type biosurfactants produced mainly by Bacillus species, consisting of a peptide loop of seven amino acids and a hydrophobic fatty acid chain (C12–C16). These molecules have been proven to exhibit various biological activities; thus, their therapeutic and environmental applications are considered. Within the surfactin lipopeptide family, there is a wide spectrum of different homologues and isomers; to date, more than 30 variants have been described. Since the newest members of these lipopeptides were described recently, there is no information that is available on their characteristic features, e.g., the dependence of their production from different cultivation parameters. This study examined the effects of both the different carbon sources and various metal ions on the surfactin production of a selected B. subtilis strain. Among the applied carbon sources, fructose and xylose had the highest impacts on the ratio of the different variants, regarding both the peptide sequences and the lengths of the fatty acids. Furthermore, the application of metal ions Mn2+, Cu2+ and Ni2+ in the media completely changed the surfactin variant compositions of the fermenting broths leading to the appearance of methyl esterified surfactin forms, and resulted in the appearance of novel surfactin variants with fatty acid chains containing no more than 11 carbon atoms.
Preservation of Cichoric Acid Antioxidant Properties Loaded in Heat Treated Lactoferrin Nanoparticles
Authors: Li Junyi , Zhao Caicai , Wei Liping , Li Xiang , Liu Fuguo , Zhang Min , Liu Xuebo , Wang Yutang
Published: October 2018

In the current research, a new cichoric acid (CA) encapsulation system was investigated. The optimal condition for the formation of lactoferrin-cichoric acid nanoparticles (LF-CA NPs) was determined by controlling the solution pH, the thermal treatment conditions, and the concentration of CA. Fluorescence indicated that the electrostatic force and the hydrophobic force were the main forces in the formation of LF-CA NPs. LF-CA NPs prepared under different conditions were spherical in shape with smaller particle sizes and good zeta potential demonstrating good colloidal stability. Especially, the prepared particle size of the LF-CA NPs at pH 7 and 95 °C was about 67.20 ± 1.86 nm. The circular dichroism (CD) and the Fourier transform infrared spectroscopy (FTIR) results showed that the combination of LF (lactoferrin) and CA affected the secondary structure of the LF. The differential scanning calorimetry (DSC) results indicated that the addition of CA increased the thermal stability of LF. In vitro antioxidant experiments confirmed the antioxidant capacity of LF-CA NPs was better than CA. CA was successfully encapsulated into LF NPs with high encapsulated efficiency (97.87–99.87%) by high performance liquid chromatography (HPLC). These results showed that LF could be used as the wall material of CA with excellent nature.
Computational Study of Mechanism and Thermodynamics of Ni/IPr-Catalyzed Amidation of Esters
Authors: Ji Chong-Lei , Xie Pei-Pei , Hong Xin
Published: October 2018

Nickel catalysis has shown remarkable potential in amide C–N bond activation and functionalization. Particularly for the transformation between ester and amide, nickel catalysis has realized both the forward (ester to amide) and reverse (amide to ester) reactions, allowing a powerful approach for the ester and amide synthesis. Based on density functional theory (DFT) calculations, we explored the mechanism and thermodynamics of Ni/IPr-catalyzed amidation with both aromatic and aliphatic esters. The reaction follows the general cross-coupling mechanism, involving sequential oxidative addition, proton transfer, and reductive elimination. The calculations indicated the reversible nature of amidation, which highlights the importance of reaction thermodynamics in related reaction designs. To shed light on the control of thermodynamics, we also investigated the thermodynamic free energy changes of amidation with a series of esters and amides.