bluuebunny/crossref_metadata_2025 huggingface dataset:
Physico-Mechanical Properties and Durability Aspects of Alkali-Activated Calcareous Fly Ash/Slag Mortars
Authors: Papayianni Ionna , Konopisi Stavroula , Kesikidou Fotini
Published: January 2018

In this paper, the physico-mechanical properties of alkali-activated mortars (CF/S) containing calcareous fly ash (CF) from the combustion of lignite and ladle furnace slag (S) from the steelmaking process as binders as well as sand and glass cullet as inert material have been studied. The constituents were mixed with the alkaline activator (NaOH:Na2SiO3 was 1:1). The binders and aggregates were used in a ratio 1:3 while a part of sand was replaced by glass aggregates (60%). The specimens (dimensions 40x40x160 mm) of alkali-activated mixtures CF/S: 100/0, 80/20 and 50/50 were cured at 25 °C for 2 days and then were placed in humid environment (95±5 % RH, 25 °C). Then the mechanical strength and porosity at 7-d, 28-d and 90-d age were measured. All of the CF/S specimens exhibited compressive strength around 15 MPa at 28 days. After the 28-d age the specimens of CF/S mortars were exposed to wetting/drying and freeze/thaw cycles to have an estimation of durability of alkali-activated CF/S mortars and compared to the Portland I42.5 cement mortars (PC) of high strength 43 MPa. Mass loss of specimens was measured by weighing them. The results showed that alkali-activated CF/S mortars appear to have similar or slight lower behavior to wetting/drying and freeze/thaw cycles compared to net cement mortars.
Influence of Sulphides on Hydration of Ground Granulated Slag Alkali Activated Mortars and Pastes
Authors: Kotwica Łukasz , Kapeluszna Ewa , Stępień Piotr , Deja Jan , Illikainen Mirja , Gołek Łukasz
Published: January 2018

Influence of sodium sulphide on properties of sodium hydroxide activated ground granulated blast furnace slag was investigated. Properties of both fresh (cone flow, density) as well as hardened (compressive strength) mortars were determined. Early hydration of pastes was investigated using conducting calorimetry. Results showed, that introduction of sodium sulphide to caustic soda activated slag only slightly influence the course of hydration process. Early strength is increased by about 10%. In later periods strength is virtually not affected by the presence of sodium sulphide. Those observations are confirmed by calorimetric results. Presence of sodium sulphide causes slight decrease in consistency of mortars. Colour of mortars is also affected by the presence of sulphides. It is more darker and it is most probably due to the reducing properties of sulphide ions. Results of model investigations on precipitated C-S-H phase showed, that presence of sulphides results in increased main basal spacing of C-S-H phase as determined by XRD.
Alkali Activation of HCFA Mixtures with Aluminosilicate Additives - Mechanical Characteristics
Authors: Papayianni Ionna , Kesikidou Fotini , Konopisi Stavroula
Published: January 2018

Over the last years, the increasing need of cost saving and environmental protection has led to finding alternative methods and materials in construction. One of these methods is the alkali-activation, which can transform alumino-silicate binders, like siliceous fly ashes, blast furnace slags, into useful materials. On the other hand, little focus has been given to study the potential uses of high calcium fly ashes (HCFAs), which are also produced in Europe and constitute the half of total fly ash output.In this paper, a calcareous fly ash (F) from Agios Demetrios power plant in Greece was studied in combination with different alumino-silicate materials such as pozzolan, diatomite and brick dust in order to improve their physico-mechanical characteristics. Pastes were mixed with an alkaline activator, which consists of a sodium silicate solution and sodium hydroxide solution 10M. The weight ratio of NaOH:Na2SiO3 was 1:1. At the fresh state, setting time of the mixture was measured after mixing. Prismatic specimens were matured at different temperature conditions (25°C for 2 days and 65°C for 2 days). The samples were tested under flexural and compressive strength at the ages of 2, 7 and 28 days. Volume deformation and open porosity were also determined.
Removal of Cr(VI) from Aqueous Solutions Using Clay from Calumbi Geological Formation, N. Sra. Socorro, SE State, Brazil
Authors: Rezende J.C.T. , Ramos V.H.S. , Oliveira H.A. , Oliveira Rosane Maria Pessoa Betânio , Jesus E.
Published: January 2018

Conventional processes for heavy metal removal are costly. Natural and modified clay with quaternary ammonium salt were used as adsorbent for the removal of Cr (VI) from aqueous solutions. Clays were characterized using Fourier transform infrared spectroscopy FTIR, thermal analysis (TG/DTA) and X-ray diffraction (XRD). Cr (VI) determination was conducted by ultraviolet-visible spectrophotometry, using complexation with 1,5-diphenylcarbazide. Absorbance was measured at the wavelength of 540 nm. The experiments were conducted at 25 ± 1 °C; initial Cr (VI) concentration of 4 to 25 mg L-1; initial pH of 2, agitation of 150 rpm; contact time of 120 minutes and clay mass of 0.1 g. Natural and modified clays exhibited a maximum adsorption capacity of 2.548 mg g-1 and 17.24 mg g-1, respectively, in accordance with the Langmuir isotherm model. X-ray diffraction analysis of clay indicated that the sample consists mainly of kaolinite and montmorillonite.
Replacement of NdFeB by Ferrite Magnets
Authors: de Campos Marcos Flavio , Rodrigues Daniel , de Castro Jose Adilson
Published: January 2018

The replacement of NdFeB magnets by ferrite magnets is discussed. For motors, remanence is relevant, implying in a volume three times that of NdFeB, when the relevant index of merit is remanence. However, if the relevant issue is the BHmax (maximum energy product), the volume for replacement should be ten times larger. The high resistivity of ferrites is a big advantage for motors. The temperature of operation is also relevant, because NdFeB magnets loss coercivity even with small increase of temperature. Different applications are discussed, as for instance, motors for electric cars and wind turbines. The choice of the proper volume depends on the evaluation of demagnetizing field in the condition of operation.
Characterization of Al2O3-Al2TiO2 Ceramic Composites: Effects of Sintering Parameters on the Properties
Authors: Pais Alves Manuel Fellipe Rodrigues , Cossu Caio Marcelo Felbinger Azevedo , Magnago Roberto de Oliveira , Ramos Alfeu Saraiva , dos Santos Claudinei
Published: January 2018

This study aims to evaluate the effects of sintering parameters in crystalline phases, microstructure and mechanical properties of composites obtained through the Al2O3-TiO2 ceramic system. Cylindrical specimens, containing molar ratio of 3 Al2O3: 1 TiO2, were uniaxially pressed at 100 MPa. The applied sintering parameters were varied in five distinct temperature ranges (1300°C, 1400°C, 1500°C, 1575°C or 1600°C) for 2h and 1600°C for 10h. After sintering, samples were characterized by relative density, X-ray diffraction, scanning electron microscopy and mechanical properties (hardness and fracture toughness). After sintering the results point to a microstructure with grains near to 2.5mm, independent of the present phases and crystalline phases composed of: Al2O3 rhombohedral, TiO2 tetragonal e Al2TiO5 orthorhombic. The specimens sintered at 1600°C-10h feature densification 30% higher them the ones sintered at 1300°C-2h, reaching a density higher than 85% of theoretical density. The composite presents hardness higher than 1000HV and fracture toughness upper than 2.2MPam1/2. The better results for the mechanical properties were found in the composites sintered at 1600°C-10h, that showed a bigger relative density than all analyzed specimens, and only phases of Al2O3 and Al2TiO5 could be found, what means that all TiO2 was consumed in the sintering of the new composite.
Development and Characterization of Al2O3-ZrO2 Composites Using ZrO2(Y2O3)-Recycled as Raw Material
Authors: Cossu Caio Marcelo Felbinger Azevedo , Pais Alves Manuel Fellipe Rodrigues , de Assis Luiz Cláudio Lemos , Magnago Roberto de Oliveira , de Souza José Vitor Candido , dos Santos Claudinei
Published: January 2018

The objective of this work was the development of Al2O3-ZrO2 ceramic composites using recycled-source of ZrO2(Y2O3). Al2O3 powder was mixed with different proportions of ZrO2(Y2O3) arising from pre-sintered blocks used in dental prostheses manufacturing. The mixtures containing 3wt% to 15wt% ZrO2(Y2O3) were uniaxially pressed at 80MPa and sintered at 1600°C-2h. Raw materials and sintered samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), relative density, hardness and fracture toughness. The results of X-ray diffraction showed α-Al2O3 and tetragonal-ZrO2 as crystalline phases after sintering. Furthermore, the relative density in all compositions was higher than 95%. The samples presented Vickers hardness and fracture toughness higher than 1300HV and 3.5MPa. m1/2, respectively.
Ceramics and Glass-Ceramics Dental Materials: Chemical Solubility, Cytotoxicity and Mechanical Properties
Authors: Magnago Roberto de Oliveira , de Lima Abreu Carlos Eduardo , Reis Silva Ronaldo , Pais Alves Manuel Fellipe Rodrigues , Cossu Caio Marcelo Felbinger Azevedo , dos Santos Claudinei
Published: January 2018

In this work three dental ceramics were characterized according to ISO 6872: yttria-stabilized zirconia (ZrO2-Y2O3), lithium disilicate (Li2Si2O5) and the spinel-zirconia composite (MgAl2O4-ZrO2). The zirconia ceramic and the zirconia-spinel composite were sintered at 1600°C-2h, while the lithium disilicate was thermally treated at 820°C-20min. These materials were characterized by relative density, X-ray diffraction, scanning electron microscopy, hardness, fracture toughness, chemical solubility and cytotoxicity. The XRD results showed for the stabilized zirconia only the tetragonal phase of ZrO2, and to the composite only the phase MgAl2O4, Li2Si2O5 was the only phase to lithium disilicate. Relative density results showed that the zirconia and the lithium disilicate showed high densification (> 99.5%) and the composite had a relative density of 75% (10% composite doped with ZrO2) and 90% (50% doped with ZrO2). Hardness and toughness showed 450HV and 3.2MPa.m1/2 to ZrO2-MgAl2O4 composites, 525HV and 1.8MPam1/2 to lithium disilicate and 1280HV and 8.0MPa.m1/2 to zirconia. The materials evaluated showed chemical solubility <30μg/cm2 and the results of cytotoxicity tests indicated cell viability of the samples near 100% for all the materials, showing good chemical stability and potential for dental applications.
Structural Refinement by the Rietveld Method on Clinkers Obtained from Waste from Pulp and Paper Mills
Authors: Simão Lisandro , Jiusti J. , Lóh N.J. , Hotza D. , Raupp-Pereira F. , Labrincha J.A. , Montedo Oscar Rubem Klegues
Published: January 2018

Pulp and paper mills have a process that generates waste with high levels of CaO and SiO2, which can be valued as an alternative mineral source in the cement industry. In this work the lime mud, biomass ashes and WWTP sludge are used in the production of clinker. Analysis of X-ray diffraction (XRD) confirmed the crystalline phases calcite and quartz. Chemical analysis by X-ray fluorescence (XRF) identified Al2O3, CaO and SiO2, providing support for the calculation of theoretical stages by applying the Bogue equations. Five formulations and three processing temperatures (1350, 1400, 1455 °C) were studied. The products obtained and an ordinary Portland cement (OPC) were characterized by XRD with quantification by the Rietveld method. The results showed that the processing conditions used produced belíticos (higher content of C2S) and Portland (C3S content greater) ecoclinker.
Characterisation of Geopolymer Cements Obtained from Different Sources of Metakaolin
Authors: Ueno O.K. , Schwaab S. , Ganasini D. , Tomiyama M. , Folgueras Marilena Valadares , Correia Sivaldo L.
Published: January 2018

In the present study metakaolin and clay brick waste (CBW) were used as a source of silica and alumina along with precursors aiming to obtain geopolymer cements, which were characterised via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CBW was obtained from rejected clay brick industrial manufacturing process. The precursors were activated by using of 5.0, 10.0 and 15.0 [mol.L-1] KOH solutions, which was added to K2SiO3 solution at 1:1 weight ratio. To obtain the geopolymer cements the weight ratio of precursor and activators were changed at levels of 0.6, 1.0 and 1.4. The samples were prepared and cured at room temperature for 7 days. The geopolymer cement obtained from metakaolin at 15 mol.L-1 level of KOH concentration and KOH/K2SiO3 ratio of 1:1.4 provided the best cement which can be estimated by the largest reduction and dissolution of crystalline phases in the activation reaction.
A Versatile Software for Construction of the Master Sintering Curve
Authors: Batista Rafael Morgado , Naranjo J.F.R. , Muccillo Eliana Navarro Santos
Published: January 2018

Several models have been developed over the last years to study the microstructure development of ceramic and metal powders during sintering. Among the most utilized methodology one may find the Arrhenius and the so-called Master Sintering Curve (MSC). Both models involve manipulation of a large number of data, and repetitive and time-consuming calculations. In this work, was developed a versatile and friendly-user software for a PC-type computer encompassing both methodologies. The software is flexible allowing for kinetic data evaluation such as the activation energy for sintering and sintering maps. Details of the software along with its application to investigate the sintering process of 10 mol% gadolinia-doped ceria are described.
Preparation and Characterization of Tubular Composite Membranes and their Application in Water Flow Measurements
Authors: Cunha Rochélia Silva Souza , Mota Joseane Damasceno , Mota Mariaugusta Ferreira , Rodrigues Meiry Gláucia Freire , Machado Fabricio
Published: January 2018

The latest technologies require materials with combination of properties that are not usually found in conventional materials. Organic-inorganic hybrid materials emerge as alternatives to the synthesis of low cost new functional materials. The constituent polymer-clay nanocomposites are intended effectively for the treatment of oily effluents. The removal of oily effluents was evaluated using composite membranes with different nanocomposite percentages, consisting of a mineral clay BrasgelTM smaller than 2 μm and ultra high molecular weight polyethylene. The sample of clay was characterized by X-Ray Diffraction (XRD) and Cation Exchange Capacity (CEC), while the membranes by scanning electron microscope (SEM). The produced composite membranes efficiencies were evaluated by continuous flow for 1 hour. The results clearly confirmed that membranes incorporated with a higher percentage of nanocomposites achieved greater stability and less time as assessed in water flow.
Rice Husk Ash as a Raw Material to Produce Willemite Pigments
Authors: Vieira L.A. , Folgueras Marilena Valadares , Tomiyama M. , Prim S.R.
Published: January 2018

This study focuses in the synthesis of ceramic pigments based on the crystal structure of willemite (Zn2SiO4). The willemite obtained from the combination of commercial zinc oxide and rice husk ash is produced in a conventional ceramic process without the use of mineralizer agent and with the addition of cobalt oxide or nickel oxide as the source of chromophore ions. The synthesis temperature used was 1200°C. The characterization of pigments involves the use of X-ray diffraction and scanning electron microscopy. The pigments applied in matte enamel and sintered at 1100°C or 1200°C developed color between blue and beige. The construction of absorbance curves showed the color development behavior of each pigment. The results showed the possibility of obtaining willemite, from rice husk ash and the color development efficiency of the material, besides showing the interference of chromophore ion (Ni and Co) in color development.
Preparation and Characterization of Pb(Zr,Ti)O3 Obtained by the Pechini Method
Authors: Andrades Raphael Cons , Munhoz Jr. Antônio Hortencio , de Miranda Leila Figueiredo , Ayres Rocha Renata
Published: January 2018

The aim of this work was to synthesize lead zirconate titanate, Pb(Zr0.52Ti0.48)O3 (PZT) via Pechini method, to characterize the polymeric precursor through differential thermal analysis and thermogravimetric analysis, as well as to characterize the PZT powder through x-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. In this work, the metallic precursors used during the PZT synthesis were titanium IV isopropoxide, zirconyl nitrate and lead nitrate; citric acid and ethylene glycol were used as chelating and polymerizing agents, respectively. The polymeric precursor was calcined at 800°C for two hours in a muffle oven. The main results showed that the polymeric precursor undergoes decomposition at approximately 316°C and PZT is crystallized around 722°C. It was confirmed that the PZT powder has chemical composition in the morphotropic phase boundary and its morphology consists of agglomerates of particles. Finally, it was proved that the PZT powder is crystalline, with the predominance of the tetragonal phase.
cIAP1/2–TRAF2–SHP-1–Src–MyD88 Complex Regulates Lipopolysaccharide-Induced IL-27 Production through NF-κB Activation in Human Macrophages
Authors: Busca Aurelia , Konarski Yulia , Gajanayaka Niranjala , O’Hara Shifawn , Angel Jonathan , Kozlowski Maya , Kumar Ashok
Published: January 2018

The inhibitors of apoptosis (IAP) proteins, initially described in the context of apoptosis regulation as promoting cell survival, have recently emerged as key regulators of innate immune signaling. As a result, downregulation of IAP via Smac mimetics (SMM) has both survival and immunoregulatory effects. IAPs modulate cytokine production in murine models either as a single agent or in response to LPS. However, the role of SMM and the involvement of IAPs in primary human cells and in particular macrophages with respect to cytokine production and innate immune responses remain largely unknown. IL-27, a member of the IL-12 cytokine family produced by APCs such as macrophages, has broad immunoregulatory properties in both innate and adaptive immune responses. Herein, we show that cellular IAPs (cIAPs) positively regulate LPS-induced IL-27 production in both primary human monocytes and macrophages. Investigations for the signaling mechanism of cIAPs involvement in IL-27 production in human macrophages revealed that LPS-induced IL-27 production is regulated by a novel signaling complex comprising cIAP1/2, TNFR-associated factor 2 (TRAF2), SHP-1, Src, and MyD88 leading to p38, c-Jun N-terminal kinases (JNK) and Akt activation and NF-κB signaling. In cancer cells, SMM induce the production of cytokines by activating the noncanonical alternate NF-κB pathway. However, in human macrophages, SMM do not induce the production of TNF-α and other cytokines while inhibiting LPS-induced IL-27 production by inhibiting the classical NF-κB pathway. These signaling pathways may constitute novel therapeutic avenues for immune modulation of IL-27 and provide insight into the modulatory immune effects of SMM.
Erythrocyte Saturation with IgG Is Required for Inducing Antibody-Mediated Immune Suppression and Impacts Both Erythrocyte Clearance and Antigen-Modulation Mechanisms
Authors: Cruz-Leal Yoelys , Marjoram Danielle , Lazarus Alan H.
Published: January 2018

Anti-D prevents hemolytic disease of the fetus and newborn, and this mechanism has been referred to as Ab-mediated immune suppression (AMIS). Anti-D, as well as other polyclonal AMIS-inducing Abs, most often induce both epitope masking and erythrocyte clearance mechanisms. We have previously observed that some Abs that successfully induce AMIS effects could be split into those that mediate epitope masking versus those that induce erythrocyte clearance, allowing the ability to analyze these mechanisms separately. In addition, AMIS-inducing activity has recently been shown to induce Ag modulation (Ag loss from the erythrocyte surface). To assess these mechanisms, we immunized mice with transgenic murine RBCs expressing a single Ag protein comprising a recombinant Ag composed of hen egg lysozyme, OVA sequences comprising aa 251–349, and the human Duffy transmembrane protein (HOD-Ag) with serial doses of polyclonal anti-OVA IgG as the AMIS-inducing Ab. The anti-OVA Ab induced AMIS in the absence of apparent epitope masking. AMIS occurred only when the erythrocytes appeared saturated with IgG. This Ab was capable of inducing HOD-RBC clearance, as well as loss of the OVA epitope at doses of Ab that caused AMIS effects. HOD-RBCs also lost reactivity with Abs specific for the hen egg lysozyme and Duffy portions of the Ag consistent with the initiation of Ag modulation and/or trogocytosis mechanisms. These data support the concept that an AMIS-inducing Ab that does not cause epitope masking can induce AMIS effects in a manner consistent with RBC clearance and/or Ag modulation.
Cytokine- and TCR-Mediated Regulation of T Cell Expression of Ly6C and Sca-1
Authors: DeLong Jonathan H. , Hall Aisling O’Hara , Konradt Christoph , Coppock Gaia M. , Park Jeongho , Harms Pritchard Gretchen , Hunter Christopher A.
Published: January 2018

Ly6C and Sca-1 (Ly6A/E) are Ly6 family GPI-anchored surface molecules that are differentially expressed by multiple immune populations. Ly6C expression has been used to distinguish short-lived effector CD4+ T cells from memory precursor effector cells, whereas Sca-1 has been used in the identification of CD8+ memory stem cells. This study examines the expression patterns of these molecules and establishes that, in vitro, IL-27, type I IFN, and IFN-γ are potent inducers of Ly6C and Sca-1 in naive mouse CD4+ and CD8+ T cells, whereas TGF-β limits their expression. The induction of Ly6C and Sca-1 by IL-27 and IFN-γ is dependent on STAT1, but not STAT3 or T-bet. In mouse splenocytes, at homeostasis, Ly6C and Sca-1 expression was not restricted to effector cells, but was also found at various levels on naive and memory populations. However, in response to infection with Toxoplasma gondii, pathogen-specific T cells expressed high levels of these molecules and in this context, endogenous IL-27 and IFN-γ were required for the expression of Ly6C but not Sca-1. Together, these findings highlight the TCR-dependent and cytokine-mediated signals that modulate T cell expression of Ly6C and Sca-1 in vitro and in vivo during infection.
The Hypoxia–Adenosine Link during Intestinal Inflammation
Authors: Bowser Jessica L. , Phan Luan H. , Eltzschig Holger K.
Published: January 2018

Intestinal inflammation is a key element in inflammatory bowel disease and is related to a combination of factors, including genetics, mucosal barrier dysfunction, bacteria translocation, deleterious host–microbe interactions, and dysregulated immune responses. Over the past decade, it has been appreciated that these inflammatory lesions are associated with profound tissue hypoxia. Interestingly, an endogenous adaptive response under the control of hypoxia signaling is enhancement in adenosine signaling, which impacts these different endpoints, including promoting barrier function and encouraging anti-inflammatory activity. In this review, we discuss the hypoxia–adenosine link in inflammatory bowel disease, intestinal ischemia/reperfusion injury, and colon cancer. In addition, we provide a summary of clinical implications of hypoxia and adenosine signaling in intestinal inflammation and disease.
Human and Rhesus Macaque KIR Haplotypes Defined by Their Transcriptomes
Authors: Bruijnesteijn Jesse , van der Wiel Marit K. H. , Swelsen Wendy T. N. , Otting Nel , de Vos-Rouweler Annemiek J. M. , Elferink Diënne , Doxiadis Gaby G. , Claas Frans H. J. , Lardy Neubury M. , de Groot Natasja G. , Bontrop Ronald E.
Published: January 2018

The killer-cell Ig-like receptors (KIRs) play a central role in the immune recognition in infection, pregnancy, and transplantation through their interactions with MHC class I molecules. KIR genes display abundant copy number variation as well as high levels of polymorphism. As a result, it is challenging to characterize this structurally dynamic region. KIR haplotypes have been analyzed in different species using conventional characterization methods, such as Sanger sequencing and Roche/454 pyrosequencing. However, these methods are time-consuming and often failed to define complete haplotypes, or do not reach allele-level resolution. In addition, most analyses were performed on genomic DNA, and thus were lacking substantial information about transcription and its corresponding modifications. In this paper, we present a single-molecule real-time sequencing approach, using Pacific Biosciences Sequel platform to characterize the KIR transcriptomes in human and rhesus macaque (Macaca mulatta) families. This high-resolution approach allowed the identification of novel Mamu-KIR alleles, the extension of reported allele sequences, and the determination of human and macaque KIR haplotypes. In addition, multiple recombinant KIR genes were discovered, all located on contracted haplotypes, which were likely the result of chromosomal rearrangements. The relatively high number of contracted haplotypes discovered might be indicative of selection on small KIR repertoires and/or novel fusion gene products. This next-generation method provides an improved high-resolution characterization of the KIR cluster in humans and macaques, which eventually may aid in a better understanding and interpretation of KIR allele–associated diseases, as well as the immune response in transplantation and reproduction.
Evaluation of nutrition knowledge of professional football players
Authors: Denna Isam , Elmabsout Ali , Eltuhami Ashmisa , Alagory Shehab , Alfirjani Tahani , Barakat Fatima , Almajouk Saif-Aleslam , Younis Mustafa
Published: January 2018

Background: Adequate knowledge of nutrition is believed to influence the performance of endurance athletes. Objectives: To assess the level of nutrition knowledge among football players in Benghazi. Subjects and Methods: Following ethical approval, a cross-sectional study was conducted involving 101 football (soccer) players (25 ± 5 years of age) from seven clubs of the first and second divisions. The height (cm) and weight (kg) were recorded for each player. A questionnaire composed of three sections was filled out by each participant. It included questions concerning personal data, general nutrition, and specific knowledge concerning the appropriate foods to consume before, during, and after exercise. Results: The mean body mass index was 24 ± 2 kg/m2. Fifty-seven percent of the participants were below the university level of formal education. Furthermore, 75% reported that they never received any formal education related specifically to nutrition. In addition, 70% had no knowledge of the concept of the food pyramid, and only 18% of the players communicated with dieticians either during season or off-season. Only 22% answered correctly the questions about which foods are appropriate to consume before and after exercise. Noticeably, 81% of the participants did not correctly identify the contents of the nutrient to be consumed during exercise. Conclusions: The study revealed an alarming lack of nutrition knowledge among professional football players in Benghazi. The results highlight the need to establish specific programs for nutrition education for the players to enhance their knowledge in this critical area and positively influence their dietary habits and ultimately improve their physical performance. It is also important to emphasize the role of qualified dieticians in athletic clubs.
Rate, Timing, and Severity of hypoglycemia in adolescents with Type 1 diabetes during ramadan fasting: A study with freestyle libre flash glucose monitoring system
Authors: Afandi Bachar , Kaplan Walid , Majd Lina , Roubi Sana
Published: January 2018

Objectives: The objective of this study is to assess the frequency, timing, and severity of hypoglycemia in adolescents with type 1 diabetes mellitus (T1DM) during fasting the month of Ramadan. Patients and Methods: Twenty-five adolescents with T1DM who fasted Ramadan were monitored using the FreeStyle Libre® flash glucose monitoring (FGM) system. Percentage and total duration of hypoglycemia were extracted from the FGM downloads, and the differences were compared between different times of the day and night according to the eating pattern in Ramadan. Results: Mean age was 16 ± 3 years and mean glycated hemoglobin was 8.6 ± 1.2%, mean glucose level was 200 ± 84 mg/dl (11.1 ± 4.7 mmol/L), and the overall time spent in hypoglycemia was 5.7% ±3.0%. The average daily time spent in hypoglycemia was 1.39 h per patient. The incidence of hypoglycemia was 0% from 19:00 to 23:00 pm and 69% from 11:00 to 19:00. Analysis of hypoglycemia revealed that 65% were between 61 and 70 mg/dl and 8% lower than 50 mg/dl. Conclusions: Hypoglycemia is typically encountered during the hours preceding Iftar time indicating an over-effect of basal insulin. Basal insulin reduction is necessary to minimize the risk of hypoglycemia
Poisson statistics of eigenvalues in the hierarchical Dyson model
Authors: Bendikov Alexander Davidovich , Braverman Anton , Pike John
Published: January 2018

Пусть $(X,d)$ - локально компактное сепарабельное ультраметрическое пространство. Для заданных меры $m$ на $X$ и функции $C$, определенной на множестве $\mathcal{B}$ всех шаров $B\subset X$, рассматривается иерархический лапласиан $L=L_C$. Оператор $L$ действует на пространстве $L^2(X,m)$, является существенно самосопряженным и имеет чисто точечный спектр. Выбор семейства $\{\varepsilon(B)\}_{B\in\mathcal{B}}$ независимых одинаково распределенных случайных величин определяет возмущенную функцию $\mathcal{C}(B)=C(B)(1+\varepsilon(B))$ и возмущенный иерархический лапласиан $\mathcal{L}=L_{\mathcal{C}}$. Все «исходы» возмущенного оператора $\mathcal{L}$ являются иерархическими лапласианами. В частности, все они имеют чисто точечный спектр. Мы изучаем эмпирический точечный процесс $M$, определяемый в терминах собственных значений оператора $\mathcal{L}$. При некоторых естественных предположениях процесс $M$ можно аппроксимировать пуассоновским точечным процессом. Используя результат Р. Арратьи, Л. Гольдштейна и Л. Гордона, основанный на методе Чена-Стейна, мы устанавливаем для пуассоновской аппроксимации скорость сходимости в метрике полной вариации. Нашу теорию мы применяем к случайным возмущениям оператора $\mathfrak{D}^\alpha$, определяемого как $p$-адическая дробная производная порядка $\alpha>0$.
О построении явных оценок в задачах нелинейной регрессии
Authors: Linke Yuliana Yurievna , Borisov Igor' Semenovich
Published: January 2018

В работе предложен достаточно общий подход к построению явных состоятельных оценок для некоторых классов моделей нелинейной регрессии. Эти оценки могут быть использованы в качестве предварительных для одношаговых процедур, позволяющих в явном виде находить в известном смысле оптимальные оценки.
Моделирование и подгонка временных рядов с тяжелыми хвостами распределений и сильной временной зависимостью посредством гауссовских рядов
Authors: Mazur Anna Evgen'evna
Published: January 2018

В модели гауссовского копульного временного ряда с хвостами одномерных распределений, принадлежащих области максимального притяжения Фреше, и гауссовским описанием зависимости [1], построена оценка для копулы, т.е. нелинейного преобразования, переводящего гауссовские величины в величины из области максимального притяжения Фреше. Это дает возможность статистического анализа временных рядов данных, предположительно имеющих тяжелые хвосты, с использованием техники асимптотического анализа гауссовских последовательностей. Доказана состоятельность и асимптотическая нормальность этой оценки.
A functional central limit theorem for integrals of stationary mixing random fields
Authors: Kampf Jurgen , Spodarev Evgenii
Published: January 2018

В статье доказывается функциональная центральная предельная теорема для процесса нормированных интегралов $\int_W f(X(t)) dt$, где $(X(t))_{t\in\mathbf{R}^d}$ является стационарным перемешивающим случайным полем, а рассматриваемый случайный процесс индексирован функциями $f$. При этом область интегрирования $W$ неограниченно растет по Ван Хову. Также обсуждаются свойства ковариационной функции предельного гауссовского процесса.
Factors associated with anxiety and depression in hospitalized patients with first episode of acute myocardial infarction
Authors: Alexandri Angeliki , Georgiadi Elpida , Mattheou Paschalia , Polikandrioti Maria
Published: January 2018

Introduction: Evaluation of anxiety and depression in cardiac patients is an area of nursing practice that is frequently neglected. The aim of the study was to explore anxiety and depression in hospitalized patients with their first episode of acute myocardial infarction.

Material and methods: The study sample included 148 hospitalized patients who had a first episode of acute myocardial infarction. Data collection was performed by the interview method using a specially designed questionnaire which included socio-demographic, clinical and other patients’ characteristics as well as the Hospital Anxiety and Depression Scale (HADS) to assess patients’ levels of anxiety and depression.

Results: Analysis of data showed that 52% and 38% of participants had high levels of anxiety and depression, respectively. Furthermore, anxiety levels revealed a statistically significant association with anxiolytics (p = 0.005) and antidepressant medication (p = 0.026) in hospital, the belief that they will face difficulties in relations with the social and family environment (p = 0.009 and p = 0.002, respectively) and whether they considered themselves anxious (p = 0.003). Depression was statistically significantly associated with education level (p = 0.001), profession (p = 0.007), antidepressant medication in hospital (p  0.001), patients’ relations with nursing staff (p = 0.019) and patients’ belief that they will face difficulties in relations with the social and family environment (p  0.001 and p  0.001, respectively).

Conclusions: The results showed that socio-demographic and clinical characteristics should be taken into serious consideration when exploring anxiety and depression in patients with a first episode of acute myocardial infarction in order to implement appropriate interventions.
Non-hemorrhage-related adverse effects of rivaroxaban
Authors: Christopoulou Eliza C. , Filippatos Theodosios D. , Elisaf Moses S.
Published: January 2018

The direct oral anticoagulant rivaroxaban is useful in various indications that include venous deep vein thrombosis prophylaxis/treatment after knee/hip replacement surgery and prevention of stroke in patients with non-valvular atrial fibrillation. Its mechanism of action has been mostly associated with hemorrhage-related adverse effects; thus a number of non-hemorrhage-related adverse effects of the drug have received less attention or go unrecognized. These adverse effects mainly include liver injury, hypersensitivity reactions, leukocytoclastic vasculitis and hair loss. Clinicians should be aware of these rare adverse reactions and advise their patients to contact them as soon as they observe any unexpected clinical response.
Comparison of ECHAM5/MESSy Atmospheric Chemistry (EMAC) Simulations of the Arctic winter 2009/2010 and 2010/2011 with Envisat/MIPAS and Aura/MLS Observations
Authors: Khosrawi Farahnaz , Kirner Oliver , Stiller Gabriele , Höpfner Michael , Santee Michelle L. , Kellmann Sylvia , Braesicke Peter
Published: January 2018

Abstract. We present model simulations with the atmospheric chemistry-climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) nudged toward European Center for Medium-Range Weather Forecasts (ECMWF) reanalyses for the Arctic winter 2009/2010 and 2010/2011. This study is the first to perform an extensive assessment of the performance of the EMAC model for Arctic winters; previous studies have only made limited evaluations of EMAC simulations for the Arctic. We have chosen the two extreme Arctic winters 2009/2010 and 2010/2011 to evaluate the formation of polar stratospheric clouds (PSCs) and the representation of the chemistry and dynamics of the polar winter stratosphere in EMAC. The EMAC simulations are compared to observations by the Michelson Interferometer for Passive Atmospheric Soundings (Envisat/MIPAS) and the observations from the Aura Microwave Limb Sounder (Aura/MLS). The Arctic winter 2010/2011 was one of the coldest winters on record, leading to the strongest depletion of ozone measured in the Arctic. The Arctic winter 2009/2010 was, from the climatological perspective, one of the warmest winters on record. However, it was distinguished by an exceptionally cold stratosphere (colder than the climatological mean). Cold temperatures prevailed from mid December 2009 to mid January 2010, leading to prolonged PSC formation and existence. Significant denitrification, the removal of HNO3 from the stratosphere by sedimentation of HNO3 containing polar stratospheric cloud particles, occurred. In our comparison, we focus on polar stratospheric cloud formation and denitrification. The comparisons between EMAC simulations and satellite observations show that model and measurements compare well for these two Arctic winters (differences for HNO3 generally within ±20 %) and thus that EMAC nudged toward ECMWF reanalyses is capable of giving a realistic representation of the evolution of PSCs and the associated sequestration of gas-phase HNO3 in the polar winter stratosphere. However, simulated PSC volume densities are several orders of magnitude smaller than the ones derived from Envisat/MIPAS observations. Further, PSCs in EMAC are not simulated as high up as they are observed. This underestimation of PSC volume density and vertical extension of the PSCs results in an underestimation of the vertical redistribution of HNO3 due to denitrification/re-nitrification.
Strong impacts on aerosol indirect effects from historical oxidant changes
Authors: Karset Inger Helene Hafsahl , Berntsen Terje Koren , Storelvmo Trude , Alterskjær Kari , Grini Alf , Olivié Dirk , Kirkevåg Alf , Seland Øyvind , Iversen Trond , Schulz Michael
Published: January 2018

Abstract. Uncertainties in effective radiative forcings through aerosol-cloud interactions (ERFaci, also called aerosol indirect effects) contribute strongly to the uncertainty in the total preindustrial-to-present-day anthropogenic forcing. Some forcing-estimates of the aerosol indirect effects are so negative that they even offset the greenhouse gas forcing. This study highlights the role of oxidants in modeling of the preindustrial-to-present-day aerosol indirect effects. We argue that the aerosol precursor gases should be exposed to oxidants of its era to get a more correct representation of secondary aerosol formation. Our model simulations show that the total aerosol indirect effect changes from −1.32 W m−2 to −1.07 W m−2 when the precursor gases in the preindustrial simulation are exposed to preindustrial instead of present-day oxidants. This happens because of a brightening of the clouds in the preindustrial simulation, mainly due to large changes in the nitrate radical (NO3). The weaker oxidative power of the preindustrial atmosphere extends the lifetime of the precursor gases, enabling them to be transported higher up in the atmosphere and towards more remote areas where the susceptibility of the cloud albedo to aerosol changes is high. The oxidation changes also shift the importance of different chemical reactions and produce more condensate, thus increasing the size of the aerosols and making it easier for them to activate as cloud condensation nuclei.
Functional spatial contextualisation of the effects of multiple stressors in marine bivalves
Authors: Giacoletti Antonio , Sarà Gianluca
Published: January 2018

Abstract. Many recent studies have revealed that the majority of environmental stressors experienced by marine organisms (ocean acidification, global warming, hypoxia etc.) occur at the same time and place, and that their interaction may complexly affect a number of ecological processes. Here, we experimentally investigated the effects of pH and hypoxia on the functional and behavioural traits of the mussel Mytilus galloprovincialis, we then simulated the potential effects on growth and reproduction dynamics trough a Dynamic Energy Budget (DEB) model under a multiple stressor scenario. Our simulations showed that hypercapnia had a remarkable effect by reducing the maximal habitat size and reproductive output differentially as a function of the trophic conditions, where modelling was spatially contextualized. This study showed the major threat represented by the hypercapnia and hypoxia phenomena for the growth, reproduction and fitness of mussels under the current climate change context, and that a mechanistic approach based on DEB modelling can illustrate complex and site-specific effects of environmental change, producing that kind of information useful for management purposes, at larger temporal and spatial scales.
Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area
Authors: Yu Liang , Rozemeijer Joachim , van Breukelen Boris M. , Ouboter Maarten , van der Vlugt Corné , Broers Hans Peter
Published: January 2018

Abstract. The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN), total phosphorus (TP), NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type) for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban–agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs) in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88) between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate from the decomposition of organic matter in subsurface sediments coupled to sulfate reduction and possibly methanogenesis. The large loads of nutrient-rich groundwater seepage into the deepest polders indirectly affect surface water quality in the surrounding area, because excess water from the deep polders is pumped out and used to supply water to the surrounding infiltrating polders in dry periods. The study shows the importance of the connection between groundwater and surface water nutrient chemistry in the greater Amsterdam area. We expect that taking account of groundwater–surface water interaction is also important in other subsiding and urbanising deltas around the world, where water is managed intensively in order to enable agricultural productivity and achieve water-sustainable cities.
Note on the directional properties of meter-scale gravity waves
Authors: Peureux Charles , Benetazzo Alvise , Ardhuin Fabrice
Published: January 2018

Abstract. The directional distribution of the energy of young waves is
bimodal for frequencies above twice the peak frequency; i.e., their
directional distribution exhibits two peaks in different directions and a
minimum between. Here we analyze in detail a typical case measured with a
peak frequency fp=0.18 Hz and a wind speed of
10.7 m s−1 using a stereo-video system. This technique allows
for the separation of free waves from the spectrum of the sea-surface
elevation. The latter indeed tend to reduce the contrast between the two
peaks and the background. The directional distribution for a given wavenumber
is nearly symmetric, with the angle distance between the two peaks growing
with frequency, reaching 150∘ at 35 times the peak wavenumber
kp and increasing up to 45 kp. When considering only
free waves, the lobe ratio, the ratio of oblique peak energy density over
energy in the wind direction, increases linearly with the non-dimensional
wavenumber k∕kp, up to a value of 6 at k/kp≃22, and possibly more for shorter components. These observations extend to
shorter components' previous measurements, and have important consequences
for wave properties sensitive to the directional distribution, such as
surface slopes, Stokes drift or microseism sources.
KLINIKINIS ATVEJIS: STIVENSO-DŽONSONO SINDROMAS
Authors: Česienė Jolanta , Bračkienė Dalia , Šaknienė Jūratė , Daugalienė Inga , Bružaitė Gabrielė , Petraitis Egidijus
Published: January 2018

4 metų berniukui pirmąją atvykimo į ligoninę dieną
pagal būdingus ligos simptomus ir požymius buvo
nustatytas Stivenso–Džonsono sindromas. Priežastis
liko neidentifikuota. Ligos baigtis buvo gera. Trumpai
aptariame šį klinikinį atvejį ir palyginame su literatūroje
pateiktais mokslinių tyrimų duomenimis.
NĖŠČIŲJŲ PATIRIAMI RŪPESČIAI IR POLINKIS STRESUI
Authors: Vaškelytė Alina , Rakauskaitė Rūta
Published: January 2018

J.E. Holm ir K.A. Holroyd nustatė, kad kasdieniai rūpesčiai atspindi dirginančius, erzinančius reikalavimus, kurie atsitinka kasdieniuose susidūrimuose su aplinka, tokius kaip rūpesčiai darbe ar laiko trūkumas. Nustatyta, kad gyvenimo rūpesčiai turi didelę įtaką nėštumo bei gimdymo rezultatams. Siekiant išanalizuoti nėščiųjų patiriamus rūpesčius ir polinkį stresui buvo atliktas tyrimas dviejose Kauno miesto poliklinikose: KKP ir KCP. Tyrime dalyvavo 94 moterys: 52 KKP ir 42 KCP besilankančios nėščiosios. Tyrimo duomenims rinkti buvo naudojama rūpesčių skalė (angl. Hassles scale) ir polinkio stresui vertinti skalė. Tyrimo rezultatai parodė, jog didžioji dalis besilaukiančių moterų nurodė turinčios didelį polinkį stresui. Analizuojant nėščiųjų jaučiamus asmeninius rūpesčius, išsiskyrė trys rūpesčiai, kuriuos jautė daugiau nei trečdalis moterų, tai yra rūpestis dėl nepakankamos vidinės energijos, neramios mintys dėl ateities bei rūpestis dėl fizinės išvaizdos. Sveikatos rūpesčių grupėje trečdalis moterų jautė bendrus rūpesčius dėl sveikatos. Beveik pusė moterų jautė rūpestį dėl miego trūkumo, trečdalis nėščiųjų jautė rūpestį dėl nepakankamo poilsio ir ketvirtadalis dėl socialinių įsipareigojimų. Rūpesčius šeimoje jautė tik nedidelė dalis nėščiųjų. Apie pusė besilaukiančių moterų nurodė rūpestį dėl kylančių prekių kainų bei ketvirtadalis dėl nelaimių, eismo ir taršos. Trečdalis nėščiųjų jautė rūpesčius dėl pinigų nenumatytoms situacijoms ir daugiau nei ketvirtadalis dėl pinigų trūkumo namams. Nepasitenkinimą dabartinėmis pareigomis darbe jautė daugiau nei penktadalis nėščiųjų.