bluuebunny/crossref_metadata_2025 huggingface dataset:
Peanut Consumption in Malawi: An Opportunity for Innovation
Authors: Gama Aggrey P. , Adhikari Koushik , Hoisington David A.
Published: July 2018

Peanuts are a valuable source of nutrients, but peanut consumption patterns, consumption frequencies, and the factors influencing peanut consumption in Malawi are not known. This study surveyed consumers to fill this knowledge gap and to assess Malawian consumers’ readiness to try new food products. Out of the 489 respondents surveyed, all but three consumed peanuts (in any form). The majority (70.4%) consumed peanuts at least three times in a week. Chi-square test showed that demographic and socioeconomic variables had significant effects (p < 0.05) on peanut product preferences, the frequency of peanut consumption, and readiness to try new foods. For instance, women mostly preferred peanut flour compared to men, and peanut butter was the most preferred form for younger consumers. Logistic regression analysis showed that consumers with high school education or below were 2.35 times more likely to eat peanuts more often than consumers with post high school education. Among the participants that were ready to try new foods (54%), men and those with post high school education were 1.90 and 2.74 times more likely to try new foods than their respective counterparts. In general, the diversity of peanut products on the Malawian market is limited, and socioeconomic restrictions override consumer preferences. Therefore, future peanut-based food products innovations should explore ways to overcome such restrictions.
Photoelectric Polarimetry and the Gas Pixel Detector Yesterday, Today and Tomorrow
Authors: Costa Enrico
Published: July 2018

Since the very beginning of X-ray Astronomy, polarimetry has been suggested as a tool of diagnostics, of great potentiality. While almost all measurements of X-rays were based on detectors using the photoelectric effect, the first attempt to perform polarimetry were based on Compton scattering and Bragg diffraction. The use of photoelectric effect also for polarimetry has been hypothesized and attempted for many years but never accomplished. Only 40 years from the start of X-ray astronomy, the Gas Pixel Detector (GPD) was developed, compatible with an X-ray optics, and capable of measuring energy, time, position and polarization simultaneously. Only after 20 more years, the Imaging X-ray Polarimetry Explorer, based on the GPD detectors, will be launched. I present the story of the development of photoelectric polarimetry that arrived to the Gas Pixel Detector, and discuss the possible future evolutions.
Projected Changes of Precipitation IDF Curves for Short Duration under Climate Change in Central Vietnam
Authors: Tien Thanh Nguyen , Dutto Aldo Remo Luca
Published: July 2018

In future years, extreme weather events are expected to frequently increase due to climate change, especially in the combination of climate change and events of El Niño–Southern Oscillation. This pays special attention to the construction of intensity–duration–frequency (IDF) curves at a tempo-spatial scale of sub-daily and sub-grid under a context of climate change. The reason for this is that IDF curves represent essential means to study effects on the performance of drainage systems, damps, dikes and reservoirs. Therefore, the objective of this study is to present an approach to construct future IDF curves with high temporo-spatial resolutions under climate change in central Vietnam, using the case of VuGia-ThuBon. The climate data of historical and future from a regional climate model RegCM4 forced by three global models MPI-ESM-MR, IPSL-CM5A-LR and ICHEC-EC-EARTH are used to re-grid the resolution of 10 km × 10 km grid spacing from 25 km × 25 km on the base of bilinear interpolation. A bias correction method is then applied to the finest resolution of a hydrostatic climate model for an ensemble of simulations. Furthermore, the IDF curves for short durations of precipitation are constructed for the historical climate and future climates under two representative concentration pathway (RCP) scenarios, RCP4.5 and RCP8.5, based on terms of correlation factors. The major findings show that the projected precipitation changes are expected to significantly increase by about 10 to 30% under the scenarios of RCP4.5 and RCP8.5. The projected changes of a maximum of 1-, 2-, and 3-days precipitation are expected to increase by about 30–300 mm/day. More importantly, for all return periods (i.e., 10, 20, 50, 100, and 200 years), IDF curves completely constructed for short durations of precipitation at sub-daily show an increase in intensities for the RCP4.5 and RCP8.5 scenarios.
Geographical Clustering and Environmental Determinants of Schistosomiasis from 2007 to 2012 in Jianghan Plain, China
Authors: Niu Yingnan , Li Rendong , Qiu Juan , Xu Xingjian , Huang Duan , Qu Yubing
Published: July 2018

This study compared changes in the spatial clustering of schistosomiasis in Jianghan Plain, China by applying Kulldorff’s spatial scan statistic. The Geodetector software was employed to detect the environmental determinants of schistosomiasis annually from 2007 to 2012. The most likely spatial cluster in 2007 covered the north-central part of Jianghan Plain, whereas those observed from 2008 to 2012 were toward the south, with extended coverage in generally the same areas across various periods, and some variation nevertheless in precise locations. Furthermore, the 2007 period was more likely to be clustered than any other period. We found that temperature, land use, and soil type were the most critical factors associated with infection rates in humans. In addition, land use and soil type had the greatest impact on the prevalence of schistosomiasis in 2009, whereas this effect was minimal in 2007. The effect of temperature on schistosomiasis prevalence reached its maximum in 2010, whereas in 2008, this effect was minimal. Differences observed in the effects of those two factors on the spatial distribution of human schistosomiasis were inconsistent, showing statistical significance in some years and a lack thereof in others. Moreover, when two factors operated simultaneously, a trend of enhanced interaction was consistently observed. High-risk areas with strong interactions of affected factors should be targeted for disease control interventions.
The German Food Bank System and Its Users—A Cross-Sectional Study
Authors: Simmet Anja , Tinnemann Peter , Stroebele-Benschop Nanette
Published: July 2018

Although food banks are a well-known resource for low-income people struggling to meet their food needs, they have rarely been investigated on a large scale. This study aims to contribute to the actual debate about the potential and limitations of food banks to decrease the prevalence of food insecurity by providing a representative picture of the German food bank system and its users. Publicly accessible data were used to map residents, public welfare recipients, and food banks. In addition, a comprehensive survey was distributed to all 934 “Tafel” food banks. The results show that nearly all residents and welfare recipients have access to at least one food bank located in the districts in which they reside. Differences in the density of food banks exist between eastern and western Germany. Food banks provide mainly healthy fresh food, but they heavily rely on food donations from local retailers and on volunteer labor. Although changes in the number of user households by income seem to mirror trends in the number of welfare recipients, food bank users appear to represent only a fraction of the food-insecure population in Germany. Food banks might have the potential to improve users’ diet and food security, but they are not able to reach all food-insecure residents in Germany.
A Scale for the Management of Aggressive and Violent Behaviour (C_MAVAS): Psychometric Properties Testing in Mental Health Nurses
Authors: Cheung Teris , Mui Jolene , Ho Yuen Shan , Chien Wai Tong
Published: July 2018

Background: This study set out to examine the psychometric properties of C_MAVAS, a newly Chinese-translated version of MAVAS, a 27-item scale assessing healthcare professionals’ attitudes to the management of patient violence. Method: The English version of the MAVAS was translated and back-translated to come up with C_MAVAS. A convenience sample of 262 qualified mental health nurses working in a local psychiatric hospital was recruited. Exploratory factor analysis tested C_MAVAS’s construct validity. Results: Content validity of the C_MAVAS was very satisfactory with validity indices of 97.4% for the overall scale and 90% to 100% for individual items. Exploratory factor analysis yielded a four-factor solution: ‘interactional perspectives on patient violence’, ‘best ways perceived for violence management’, ‘internal or biomedical perspectives on patient violence’, and ‘external perspectives on patient aggression and violence’, were important in shaping their attitudes towards managing violence and patient disruptiveness. Internal consistency of the Chinese version was barely satisfactory (Cronbach’s alpha = 0.51–0.67) for the four factors/subscales and its test-retest reliability was good (Pearson’s coefficient = 0.84). Conclusion: The findings suggest the C_MAVAS is a valid and reliable tool to measure mental health nurses’ attitudes towards patient violence/aggression in a mental hospital setting.
Psychosocial Problems, Indoor Air-Related Symptoms, and Perceived Indoor Air Quality among Students in Schools without Indoor Air Problems: A Longitudinal Study
Authors: Finell Eerika , Tolvanen Asko , Pekkanen Juha , Minkkinen Jaana , Ståhl Timo , Rimpelä Arja
Published: July 2018

The effect of students’ psychosocial problems on their reporting of indoor air quality (subjective IAQ) and indoor air-related (IA-related) symptoms has not been studied in schools in a longitudinal setting. Therefore, we analyzed whether changes in students’ psychosocial problems (socioemotional difficulties and perceived teacher–student relations) between the beginning of seventh grade (age 12–13 years) and the end of ninth grade (15–16 years) predicted subjective IAQ and IA-related symptoms at the end of ninth grade. In order to explore the independent effect of psychosocial factors, we focused only on students in schools without observed indoor air problems. The analysis was of longitudinal data (N = 986 students) using latent change modelling. Increased socioemotional difficulties were related to more IA-related symptoms (standardized beta = 0.20) and deteriorated subjective IAQ (standardized beta = 0.20). Increased problems in teacher–student relations were related to deteriorated subjective IAQ (standardized beta = 0.21). Although students’ psychosocial problems explained only 9–13% of the total variances, our findings support the notion that psychosocial factors also need to be taken into account in the evaluation of IAQ and the prevalence of IA-related symptoms in schools.
Genome-Guided Characterization of Ochrobactrum sp. POC9 Enhancing Sewage Sludge Utilization—Biotechnological Potential and Biosafety Considerations
Authors: Poszytek Krzysztof , Karczewska-Golec Joanna , Ciok Anna , Decewicz Przemyslaw , Dziurzynski Mikolaj , Gorecki Adrian , Jakusz Grazyna , Krucon Tomasz , Lomza Pola , Romaniuk Krzysztof , Styczynski Michal , Yang Zhendong , Drewniak Lukasz , Dziewit Lukasz
Published: July 2018

Sewage sludge is an abundant source of microorganisms that are metabolically active against numerous contaminants, and thus possibly useful in environmental biotechnologies. However, amongst the sewage sludge isolates, pathogenic bacteria can potentially be found, and such isolates should therefore be carefully tested before their application. A novel bacterial strain, Ochrobactrum sp. POC9, was isolated from a sewage sludge sample collected from a wastewater treatment plant. The strain exhibited lipolytic, proteolytic, cellulolytic, and amylolytic activities, which supports its application in biodegradation of complex organic compounds. We demonstrated that bioaugmentation with this strain substantially improved the overall biogas production and methane content during anaerobic digestion of sewage sludge. The POC9 genome content analysis provided a deeper insight into the biotechnological potential of this bacterium and revealed that it is a metalotolerant and a biofilm-producing strain capable of utilizing various toxic compounds. The strain is resistant to rifampicin, chloramphenicol and β-lactams. The corresponding antibiotic resistance genes (including blaOCH and cmlA/floR) were identified in the POC9 genome. Nevertheless, as only few genes in the POC9 genome might be linked to pathogenicity, and none of those genes is a critical virulence factor found in severe pathogens, the strain appears safe for application in environmental biotechnologies.
Performance of Exchange Traded Funds during the Brexit Referendum: An Event Study
Authors: Alkhatib Akram , Harasheh Murad
Published: July 2018

In today’s interrelated economies, financial information travel at speed of light to reach investors around the globe. Global financial markets experience regular shocks that transmit negative waves to other equity markets and different asset classes. Given the unique characteristics of exchange-traded funds (ETFs), this paper examines how different ETFs that are traded on London Financial center reacted to the Brexit event in 23 June 2016. The unexpected referendum result the day after is viewed as the next significant financial event since 2008. The paper employs an event study market model on daily and abnormal returns of the selected ETFs with respect to FTSE 250 around the event date. Contrary to what is expected, the world equities fund experienced significant positive abnormal return on the event day. Emerging markets again proved to be a preferred investment destination in times of financial turmoil; the emerging equities fund gained 3% while enjoying an 11.5% positive significant abnormal returns. The US T-Bond fund recorded a 9% return with a significant 7.2% abnormal return. The gold fund soared as much as 4% as investors seeks refuge from Brexit, and the oil fund retraced 1% amid concerns of slowing global demand.
Epithelial Cell Cycle Behaviour in the Injured Kidney
Authors: Moonen Lies , D’Haese Patrick C. , Vervaet Benjamin A.
Published: July 2018

Acute kidney injury (AKI), commonly caused by ischemia-reperfusion injury, has far-reaching health consequences. Despite the significant regenerative capacity of proximal tubular epithelium cells (PTCs), repair frequently fails, leading to the development of chronic kidney disease (CKD). In the last decade, it has been repeatedly demonstrated that dysregulation of the cell cycle can cause injured kidneys to progress to CKD. More precisely, severe AKI causes PTCs to arrest in the G1/S or G2/M phase of the cell cycle, leading to maladaptive repair and a fibrotic outcome. The mechanisms causing these arrests are far from known. The arrest might, at least partially, be attributed to DNA damage since activation of the DNA-damage response pathway leads to cell cycle arrest. Alternatively, cytokine signalling via nuclear factor kappa beta (NF-κβ) and p38-mitogen-activated protein kinase (p38-MAPK) pathways, and reactive oxygen species (ROS) can play a role independent of DNA damage. In addition, only a handful of cell cycle regulators (e.g., p53, p21) have been thoroughly studied during renal repair. Still, why and how PTCs decide to arrest their cell cycle and how this arrest can efficiently be overcome remain open and challenging questions. In this review we will discuss the evidence for cell cycle involvement during AKI and development of CKD together with putative therapeutic approaches.
Implications of AMPK in the Formation of Epithelial Tight Junctions
Authors: Rowart Pascal , Wu Jingshing , Caplan Michael J. , Jouret François
Published: July 2018

Tight junctions (TJ) play an essential role in the epithelial barrier. By definition, TJ are located at the demarcation between the apical and baso-lateral domains of the plasma membrane in epithelial cells. TJ fulfill two major roles: (i) TJ prevent the mixing of membrane components; and (ii) TJ regulate the selective paracellular permeability. Disruption of TJ is regarded as one of the earliest hallmarks of epithelial injury, leading to the loss of cell polarity and tissue disorganization. Many factors have been identified as modulators of TJ assembly/disassembly. More specifically, in addition to its role as an energy sensor, adenosine monophosphate-activated protein kinase (AMPK) participates in TJ regulation. AMPK is a ubiquitous serine/threonine kinase composed of a catalytic α-subunit complexed with regulatory β-and γ-subunits. AMPK activation promotes the early stages of epithelial TJ assembly. AMPK phosphorylates the adherens junction protein afadin and regulates its interaction with the TJ-associated protein zonula occludens (ZO)-1, thereby facilitating ZO-1 distribution to the plasma membrane. In the present review, we detail the signaling pathways up-and down-stream of AMPK activation at the time of Ca2+-induced TJ assembly.
Genome-Wide Characterization and Expression Analyses of Pleurotus ostreatus MYB Transcription Factors during Developmental Stages and under Heat Stress Based on de novo Sequenced Genome
Authors: Wang Lining , Gao Wei , Wu Xiangli , Zhao Mengran , Qu Jibin , Huang Chenyang , Zhang Jinxia
Published: July 2018

Pleurotus ostreatus is a commercially grown mushroom species in China. However, studies on the mechanisms of the fruiting body development and stress response of P. ostreatus are still at a primary stage. In this study, we report the entire genome sequence of P. ostreatus CCMSSC03989. Then, we performed comprehensive genome-wide characterization and expression analysis of the MYB transcription factor family during a series of developmental stages and under the condition of heat stress. A 34.76 Mb genome was obtained through next-generation sequencing (NGS) and Bionano optical mapping approaches. The genome has a scaffold N50 of 1.1 Mb and contains 10.11% repeats, and 10,936 gene models were predicted. A total of 20 MYB genes (PoMYB) were identified across the genome, and the full-length open reading frames were isolated. The PoMYBs were classified into 1 repeat (1R), 2R, and 3R-MYB groups according to their MYB domain repeat numbers, and 3R-MYBs possessed relatively more introns than 1R and 2R-MYBs. Based on phylogenetic analysis, the PoMYBs were divided into four groups and showed close relationships with the MYB genes of plants and fungi. RNA-sequencing (RNA-Seq) and quantitative PCR (qPCR) analyses revealed that PoMYB expression showed stage-specific patterns in reproductive stages and could be induced by heat stress. The P. ostreatus draft genome will promote genome-wide analysis, and our study of PoMYBs will promote further functional analysis of MYB genes in mushrooms.
Poly Organotin Acetates against DNA with Possible Implementation on Human Breast Cancer
Authors: Latsis George K. , Banti Christina N. , Kourkoumelis Nikolaos , Papatriantafyllopoulou Constantina , Panagiotou Nikos , Tasiopoulos Anastasios , Douvalis Alexios , Kalampounias Angelos G. , Bakas Thomas , Hadjikakou Sotiris K.
Published: July 2018

Two known tin-based polymers of formula {[R3Sn(CH3COO)]n} where R = n-Bu– (1) and R = Ph– (2),were evaluated for their in vitro biological properties. The compounds were characterized via their physical properties and FT-IR, 119Sn Mössbauer, and 1H NMR spectroscopic data. The molecular structures were confirmed by single-crystal X-Ray diffraction crystallography. The geometry around the tin(IV) ion is trigonal bi-pyramidal. Variations in O–Sn–O···Sn′ torsion angles lead to zig-zag and helical supramolecular assemblies for 1 and 2, respectively. The in vitro cell viability against human breast adenocarcinoma cancer cell lines: MCF-7 positive to estrogens receptors (ERs) and MDA-MB-231 negative to ERs upon their incubation with 1 and 2 was investigated. Their toxicity has been studied against normal human fetal lung fibroblast cells (MRC-5). Compounds 1 and 2 exhibit 134 and 223-fold respectively stronger antiproliferative activity against MDA-MB-231 than cisplatin. The type of the cell death caused by 1 or 2 was also determined using flow cytometry assay. The binding affinity of 1 and 2 towards the CT-DNA was suspected from the differentiation of the viscosity which occurred in the solution containing increasing amounts of 1 and 2. Changes in fluorescent emission light of Ethidium bromide (EB) in the presence of DNA confirmed the intercalation mode of interactions into DNA of both complexes 1 and 2 which have been ascertained from viscosity measurements. The corresponding apparent binding constants (Kapp) of 1 and 2 towards CT-DNA calculated through fluorescence spectra are 4.9 × 104 (1) and 7.3 × 104 (2) M−1 respectively. Finally, the type of DNA binding interactions with 1 and 2 was confirmed by docking studies.
Tenogenesis of Decellularized Porcine Achilles Tendon Matrix Reseeded with Human Tenocytes in the Nude Mice Xenograft Model
Authors: Lohan Anke , Kohl Benjamin , Meier Carola , Schulze-Tanzil Gundula
Published: July 2018

Cultivation of autologous human tenocytes in a cell-free xenogenic extracellular tendon matrix (xECM) could present an approach for tendon reconstruction. The aim of this study was to achieve tendon-like tissue formation by implanting decellularized porcine Achilles tendons recellularized with human hamstring tendon-derived tenocytes into nude mice. The structure of decellularized xECM was histologically monitored before being dynamically reseeded with human tenocytes. After 6–12 weeks in vivo, construct quality was monitored using macroscopical and histological scoring systems, vitality assay and quantitative DNA and glycosaminoglycan (GAG) assays. For comparison to tendon xECM, a synthetic polyglycolic acid (PGA) polymer was implanted in a similar manner. Despite decellularized xECM lost some GAGs and structure, it could be recellularized in vitro with human tenocytes, but the cell distribution remained inhomogeneous, with accumulations at the margins of the constructs. In vivo, the xECM constructs revealed in contrast to the PGA no altered size, no inflammation and encapsulation and a more homogeneous cell distribution. xECM reseeded with tenocytes showed superior histological quality than cell-free implanted constructs and contained surviving human cells. Their DNA content after six and 12 weeks in vivo resembled that of native tendon and xECM recellularized in vitro. Results suggest that reseeded decellularized xECM formed a tendon-like tissue in vivo.
Influence of Menopause on Inflammatory Cytokines during Murine and Human Bone Fracture Healing
Authors: Fischer Verena , Kalbitz Miriam , Müller-Graf Fabian , Gebhard Florian , Ignatius Anita , Liedert Astrid , Haffner-Luntzer Melanie
Published: July 2018

Postmenopausal females display a chronic inflammatory phenotype with higher levels of circulating pro-inflammatory cytokines. Furthermore, the inflammatory response to injury may be altered under estrogen-deficiency, because it was shown previously that estrogen-deficient mice displayed increased levels of the inflammatory cytokines Midkine (Mdk) and Interleukin-6 (IL-6) in the early fracture hematoma. Because a balanced immune response to fracture is required for successful bone regeneration, this might contribute to the delayed fracture healing frequently observed in osteoporotic, postmenopausal fracture patients. In this study, we aimed to investigate whether further cytokines in addition to Mdk and IL-6 might be affected by estrogen-deficiency after fracture in mice and whether these cytokines are also relevant during human fracture healing. Additionally, we aimed to investigate whether serum from male vs. female fracture patients affects osteogenic differentiation of human mesenchymal stem cells (MSCs). To address these questions, female mice were either sham-operated or ovariectomized (OVX) and subjected to standardized femur osteotomy. A broad panel of pro- and anti-inflammatory cytokines was determined systemically and locally in the fracture hematoma. In a translational approach, serum was collected from healthy controls and patients with an isolated fracture. Mdk and IL-6 serum levels were determined at day 0, day 14 and day 42 after fracture. Subgroup analysis was performed to investigate differences between male and female fracture patients after menopause. In an in vitro approach, human MSCs were cultured with the collected patient serum and osteogenic differentiation was assessed by qPCR and alkaline-phosphatase staining. Our results suggest an important role for the pro-inflammatory cytokines Mdk and IL-6 in the response to fracture in estrogen-deficient mice among all of the measured inflammatory mediators. Notably, both cytokines were also significantly increased in the serum of patients after fracture. However, only Mdk serum levels differed significantly between male and female fracture patients after menopause. MSCs cultivated with serum from female fracture patients displayed significantly reduced osteogenic differentiation, which was attenuated by Mdk-antibody treatment. In conclusion, our study demonstrated increased Mdk levels after fracture in OVX mice and female fracture patients after menopause. Because Mdk is a negative regulator of bone formation, this might contribute to impaired osteoporotic fracture healing.
Cyclic Block Copolymer Microchannel Fabrication and Sealing for Microfluidics Applications
Authors: Yen Chia-Yi , Chang Moh-Ching O. , Shih Zong-Fu , Lien Yi-Hsing , Tsao Chia-Wen
Published: July 2018

High mechanical rigidity, chemical resistance, and ultraviolet-visible light transmissivity of thermoplastics are attractive characteristics in microfluidics because various biomedical microfluidic devices require solvent, acid, or base manipulation, and optical observation or detection. The cyclic block copolymer (CBC) is a new class of thermoplastics with excellent optical properties, low water absorption, favorable chemical resistance, and low density, which make it ideal for use in polymer microfluidic applications. In the polymer microfabrication process, front-end microchannel fabrication and post-end bonding are critical steps that determine the success of polymer microfluidic devices. In this study, for the first time, we verified the performance of CBC created through front-end microchannel fabrication by applying hot embossing and post-end sealing and bonding, and using thermal fusion and ultraviolet (UV)/ozone surface-assist bonding methods. Two grades of CBC were evaluated and compared with two commonly used cyclic olefin polymers, cyclic olefin copolymers (COC), and cyclic olefin polymers (COP). The results indicated that CBCs provided favorable pattern transfer (>99%) efficiency and high bonding strength in microchannel fabrication and bonding procedures, which is ideal for use in microfluidics.
Specification and Patterning of Drosophila Appendages
Authors: Ruiz-Losada Mireya , Blom-Dahl David , Córdoba Sergio , Estella Carlos
Published: July 2018

Appendages are external projections of the body that serve the animal for locomotion, feeding, or environment exploration. The appendages of the fruit fly Drosophila melanogaster are derived from the imaginal discs, epithelial sac-like structures specified in the embryo that grow and pattern during larva development. In the last decades, genetic and developmental studies in the fruit fly have provided extensive knowledge regarding the mechanisms that direct the formation of the appendages. Importantly, many of the signaling pathways and patterning genes identified and characterized in Drosophila have similar functions during vertebrate appendage development. In this review, we will summarize the genetic and molecular mechanisms that lead to the specification of appendage primordia in the embryo and their posterior patterning during imaginal disc development. The identification of the regulatory logic underlying appendage specification in Drosophila suggests that the evolutionary origin of the insect wing is, in part, related to the development of ventral appendages.
Detection of Moving Objects
Authors: Bouwmans Thierry
Published: July 2018

n/a
Process Forces Analysis and a New Feed Control Strategy for Drilling of Unidirectional Carbon Fiber Reinforced Plastics (UD-CFRP)
Authors: Sauer Konstantin , Dix Martin , Putz Matthias
Published: July 2018

Reliable machining of carbon fiber-reinforced plastics (CFRP) is the key for application of these lightweight materials. Due to its anisotropy, CFRP is a very difficult material to machine because of occurring delamination and fiber-pullouts. The tool design is especially crucial to minimize and to avoid these processing errors. In this paper a process analysis for drilling is shown for better understanding of the chip formation. Drilling of unidirectional CFRP enables the investigation of the effect of fiber orientation on the chip formation process. In theory, the amount of cut fibers and the cutting angle to the main cutting edge determine the cutting force. Experimental tests with varied macroscopic drill geometries verify this theory. Based on these detected relationships, the tool loads can be calculated for a successful tool design.
Parametric Thermal FE Analysis on the Laser Power Input and Powder Effective Thermal Conductivity during Selective Laser Melting of SS304L
Authors: De Moraes Diego A , Czekanski Aleksander
Published: July 2018

A low-cost parametric finite element thermal model is proposed to study the impact of the initial powder condition, such as diameter and packing density, on effective thermal conductivity as well as the impact of the laser power input on the final temperature distributions during selective laser melting (SLM). Stainless steel 304L is the material used, since it is not yet commercially available in SLM equipment and our main goal was to show the capabilities of the finite element method in the evaluation of power input in the process. The results from our sensitivity analysis showed that packing density has a greater impact on the final temperature distributions compared with powder diameter variance. However, overall the thermal conductivity of the powder only showed significant effects below the melting point, otherwise the thermal conductivity no longer affected the temperature distributions. Among the three different power inputs analyzed, the temperature profile demonstrated that power inputs of 100 and 200 W are recommended when printing SS-304L rather than 400 W, which generates too high temperature in the powder bed, a non-favorable behavior that can induce high residual stresses and material evaporation.
Potential Impacts of Sea Level Rise and Coarse Scale Marsh Migration on Storm Surge Hydrodynamics and Waves on Coastal Protected Areas in the Chesapeake Bay
Authors: Bigalbal Alayna , Rezaie Ali M. , Garzon Juan L. , Ferreira Celso M.
Published: July 2018

The increasing rate of sea level rise (SLR) poses a major threat to coastal lands and natural resources, especially affecting natural preserves and protected areas along the coast. These impacts are likely to exacerbate when combined with storm surges. It is also expected that SLR will cause spatial reduction and migration of coastal wetland and marsh ecosystems, which are common in the natural preserves. This study evaluates the potential impacts of SLR and marsh migration on the hydrodynamics and waves conditions inside natural protected areas during storm surge. The study focused on four protected areas located in different areas of the Chesapeake Bay representing different hydrodynamic regimes. Historical and synthetic storms are simulated using a coupled storm surge (ADCIRC) and wave (SWAN) model for the Bay region for current condition and future scenarios. The future scenarios include different rates of local SLR projections (0.48 m, 0.97 m, 1.68 m, and 2.31 m) and potential land use changes due to SLR driven marsh migration, which is discretized in the selected preserve areas in a coarse scale. The results showed a linear increase of maximum water depth with respect to SLR inside the protected areas. However, the inundation extent, the maximum wave heights, and the current velocities inside the coastal protected areas showed a non-linear relationship with SLR, indicating that the combined impacts of storm surge, SLR, and marsh migration depend on multiple factors such as storm track, intensity, local topography, and locations of coastal protected areas. Furthermore, the impacts of SLR were significantly greater after a 1 m threshold of rise, suggesting the presence of a critical limit for conservation strategies.
Investigating Gender Assignment Strategies in Mixed Purepecha–Spanish Nominal Constructions
Authors: Bellamy Kate , Parafita Couto M. , Stadthagen-Gonzalez Hans
Published: July 2018

Purepecha has no grammatical gender, whereas Spanish has a binary masculine–feminine system. In this paper we investigate how early sequential Purepecha–Spanish bilinguals assign gender to Purepecha nouns inserted into an otherwise Spanish utterance, using a director-matcher production task and an online forced-choice acceptability judgement task. The results of the production task indicate a strong preference for masculine gender, irrespective of the gender of the noun’s translation equivalent, the so-called “masculine default” option. Participants in the comprehension task were influenced by the orthography of the Purepecha noun in the -a ending condition, leading them to assign feminine gender agreement to nouns that are masculine in Spanish, but preferred the masculine default strategy again in the -i/-u ending condition. The absence of the “analogical criterion” in both tasks contrasts with the results of some previous studies, underlining the need for more comparable data in terms of task type. Our results also highlight how task type can influence the choices speakers make, in this context, in terms of the choice of grammatical gender agreement strategy. Task type should therefore be carefully controlled in future studies.
Microstructure and Mechanical Properties of Si3N4-Fe3Si Composites Prepared by Gas-Pressure Sintering
Authors: Guan Jiasuo , Cheng Laifei , Li Mingxing
Published: July 2018

Si3N4-Fe3Si composites were prepared using Fe-Si3N4 as the source of Fe3Si by gas-pressure sintering. By adding different amounts of Fe-Si3N4 into the starting powders, Si3N4-Fe3Si composites with various Fe3Si phase contents were obtained. The microstructure and mechanical properties of the composites were investigated. With the increase of Fe-Si3N4 contents, the content and particle size of Fe3Si both increased. When more than 60 wt. % Fe-Si3N4 were added, the abnormal growth of Fe3Si particles occurred and oversized Fe3Si particles appeared, leading to non-uniform microstructures and worse mechanical properties of the composites. It has been found that Fe3Si particles could toughen the composites through particle pull-out, interface debonding, crack deflection, and particle bridging. Uniform microstructure and improved mechanical properties (flexural strength of 354 MPa and fracture toughness of 8.4 MPa·m1/2) can be achieved for FSN40.
Keggin-Type Heteropoly Salts as Bifunctional Catalysts in Aerobic Baeyer-Villiger Oxidation
Authors: Pamin Katarzyna , Połtowicz Jan , Prończuk Mateusz , Kryściak-Czerwenka Joanna , Karcz Robert , M. Serwicka Ewa
Published: July 2018

The cobalt, manganese, and iron salts of tungstophosphoric or molybdophosphoric acid with growing content of metals were applied for the first time as catalysts in the Baeyer-Villiger (BV) oxidation of cyclohexanone to ε-caprolactone with molecular oxygen. The catalysts were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and ethanol decomposition reaction. Introduction of transition metals into the heteropoly structure increases the activity of resulting heteropoly salts in comparison with parent heteropolyacids. It was shown that the most active catalysts are salts of the heteropoly salts with one metal atom introduced and one proton left (HMPX) type, (where M = Co, Fe, Mn, and X = W, Mo) with the metal to proton ratio equal one. Among all of the studied catalysts, the highest catalytic activity was observed for HCoPW. The effect indicates that both the acidic and redox properties are required to achieve the best performance. The Baeyer-Villiger (BV) oxidation mechanism proposed identifies the participation of heteropoly compounds in three steps of the investigated reaction: oxidation of aldehyde to peracid (redox function), activation of carbonyl group (Lewis acidity), and decomposition of the Criegee adduct to ε-caprolactone (Brønsted acidity).
Synthesis of Non-Stoichiometric (TiNb)C0.5 with High Hardness and Fracture Toughness under HTHP
Authors: Zhang Zhichao , Tang Hu , Ke Yujiao , Li Yu , Jiao Xiaochen , Geng Changjian , Zhao Yucheng , Wang Mingzhi
Published: July 2018

Nonstoichiometric TiC0.5 and (TiNb)0.5 powders were prepared by the mechanical alloying process using Ti, Nb, and TiC powders as raw materials. Furthermore, the as-prepared TiC0.5 and (TiNb)0.5 powders were used as initial materials to fabricate TiC0.5 and (TiNb)0.5 compacts under high pressures and high temperatures (HTHP) of 5.5 GPa and 1200–1550 °C for 5 min. Phase identification and microstructure of the mechanical-alloyed powders and the sintered TiC0.5 and (TiNb)0.5 compacts were realized by an X-ray diffractometer and scanning electron microscope. The results indicate that the as-prepared TiC0.5 and (TiNb)0.5 powders have a similar crystal structure of face-centered cubic (FCC) to TiC. The sintered (TiNb)0.5 compact has good Vickers hardness (~16 GPa), and notably, excellent fracture toughness (~7.3 MPa·m1/2). The non-stoichiometric compound not only reduced the sintering temperature of covalent compounds, but also greatly enhanced the mechanical properties of the materials. Thus, we have provided a novel synthetic strategy for the production of a compound with high-strength covalent bonds.
On the Most Extended Modal Operator of First Type over Interval-Valued Intuitionistic Fuzzy Sets
Authors: Atanassov Krassimir
Published: July 2018

The definition of the most extended modal operator of first type over interval-valued intuitionistic fuzzy sets is given, and some of its basic properties are studied.
Decomposition of Dynamical Signals into Jumps, Oscillatory Patterns, and Possible Outliers
Authors: Barton Elena , Al-Sarray Basad , Chrétien Stéphane , Jagan Kavya
Published: July 2018

In this note, we present a component-wise algorithm combining several recent ideas from signal processing for simultaneous piecewise constants trend, seasonality, outliers, and noise decomposition of dynamical time series. Our approach is entirely based on convex optimisation, and our decomposition is guaranteed to be a global optimiser. We demonstrate the efficiency of the approach via simulations results and real data analysis.
Evaluation of a novel 14C-urea breath test “Heliprobe” in diagnosis of Helicobacter pylori infection
Authors: Jonaitis Laimas , Kiudelis Gediminas , Kupčinskas Limas
Published: July 2018

Background. At present, 14C-urea breath test is considered a gold standard for diagnosis of Helicobacter pylori infection, but they are time-consuming, comparably expensive, and usually not portable tests. The aim of our study was to establish the diagnostic value of the novel, inexpensive, quick, and convenient to use 14C-urea breath test “Heliprobe”, Noster AB, Sweden.Material and methods. Helicobacter pylori testing using “Heliprobe” was performed in 108 consecutive patients. Helicobacter pylori was also investigated using rapid urease test and Giemsa stained histological specimens according to Sydney system.Results. The diagnostic values of “Heliprobe” assuming the Helicobacter pylori positivity, if the results of two tests (rapid urease test and histology) are positive, were: sensitivity – 97%, specificity – 87%, positive predictive value – 93%, negative predictive value – 95%, accuracy – 94%. The diagnostic values of “Heliprobe” assuming the Helicobacter pylori positivity, if at least the results of one test are positive: sensitivity – 92%, specificity – 100%, positive predictive value – 100%, negative predictive value – 84%, accuracy – 94%.Conclusions. The novel, quick, convenient to use 14C-urea breath test “Heliprobe” is accurate, reliable, and useful for the diagnosis of Helicobacter pylori infection in routine clinical practice
The peculiarities of Pseudomonas aeruginosa resistance to antibiotics and prevalence of serogroups
Authors: Gailienė Greta , Pavilonis Alvydas , Kareivienė Violeta
Published: July 2018

Pseudomonas aeruginosa is one of the most common nonfermenting aerobic gramnegative microorganisms identified in clinical specimens of hospitalized patients. The emergence of multidrug-resistant (MDR) Pseudomonas aeruginosa strains is a growing concern in hospitalacquired infections. Typing of strains is important for identifying the sources of infection as well as prevention of cross-infections and monitoring of the efficacy of antimicrobial therapy. The aim of this study was to evaluate the antimicrobial resistance and prevalence of Pseudomonas aeruginosa serogroups isolated at Kaunas University of Medicine Hospital, Lithuania. Material and methods. Minimum inhibitory concentrations of piperacillin, cefoperazone, ceftazidime, cefotaxime, cefepime, imipenem, meropenem, gentamicin, amikacin, tobramycin, and ciprofloxacin for 609 Pseudomonas aeruginosa strains isolated from various clinical specimens between November 2001 and November 2002 were determined by the microdilution method in Mueller–Hinton agar using interpretative guidelines of National Committee for Clinical Laboratory Standards. Serogroups of Pseudomonas aeruginosa strains were identified using serums of Seiken Co. Ltd (Tokyo, Japan), containing antibodies against antigens of Pseudomonas aeruginosa O-group. Results. Pseudomonas aeruginosa strains were the most sensitive to ceftazidime (78.9%), imipenem (73.6%), meropenem (70.9%) and the most resistant to gentamicin (54.1%) and ciprofloxacin (52.5%). Multidrug-resistant strains made up 9.85% of all Pseudomonas aeruginosa strains investigated. Multidrug-resistant Pseudomonas aeruginosa strains were 1.5–3.5 times more resistant to antibiotics compared to non-multidrug-resistant strains, except to amikacin: multidrug-resistant strains were more sensitive (81.7%) than non-multidrug-resistant Pseudomonas aeruginosa strains (61.0%). Pseudomonas aeruginosa serogroups O:E and O:B were the most common serogroups (34.7% and 29.0%, respectively) followed by serogroups O:I (11.4%) and O:A (10.1%). Pseudomonas aeruginosa serogroup O:E strains were the most prevalent among multidrug-resistant strains (48.3%). Conclusions. The results of our study show that serogroup O:E was the most prevalent serogroup of Pseudomonas aeruginosa in our hospital, and its resistance to antibiotics was the highest.
The influence of various factors on results of subintimal angioplasty of superficial femoral artery occlusions
Authors: Aleksynas Nerijus , Kaupas Rytis
Published: July 2018

Objective. To evaluate prospectively the impact of various factors on subintimal angioplasty of superficial femoral artery. Patients and methods. Within a period of 36 months, 44 patients with 45 chronic occlusions in superficial femoral artery were examined. The influence of sex, age, hypertension, diabetes mellitus, smoking, chronic ischemia stage, occlusion length and calcification, flush occlusion of the superficial femoral artery, ischemic cardiac disease, postprocedural medical treatment was evaluated. Results. Arterial calcification had a significant impact on technical success of subintimal angioplasty (p=0.03). Sex, age, smoking, flush occlusion of the superficial femoral artery, and cardiac disease influenced technical and hemodynamic success (p=0.086–0.295). Hypertension, diabetes mellitus, chronic ischemia stage, occlusion length, and postprocedural medical treatment did not significantly influence technical and hemodynamic success (p>0.05). Conclusions. Arterial calcification had a significant impact on technical success of subintimal angioplasty. Sex, age, smoking, flush occlusion of the superficial femoral artery, and ischemic cardiac disease influenced technical and hemodynamic success. Hypertension, diabetes mellitus, chronic ischemia stage, occlusion length, and postprocedural medical treatment had no statistically significant impact on technical and hemodynamic success.
Collagen network changes in basilar artery in aging
Authors: Gudienė Devika , Valančiūtė Angelija , Vėlavičius Juozas
Published: July 2018

Objective. The aim of this study was to examine and evaluate morphometrically age-related changes in collagen network in the tunica media of human basilar artery. Materials and methods. Histological analysis of the basilar arteries obtained from 89 individuals, aged 20 to 85 years, was performed. The study has been carried out by standard histological technique; histological samples were stained with picrosirius red. Detailed quantitative analysis of collagen bundle network in the tunica media of basilar artery was performed. Results. We analyzed collagen network area, perimeter and number of collagen bundles in the tunica media of the basilar artery. After investigation of age-related changes in collagen network area in men and women, we determined that in both genders collagen network area in the tunica media of the basilar artery increased with age. Analyzing the perimeter and number of collagen bundles in both genders by different age groups, it was found that they decreased with age. We found a statistically significant correlation between all the measured parameters and the age. Conclusions. The area of collagen bundles increased, the number and perimeter of collagen bundles decreased with age in both genders in the tunica media of human basilar artery. While aging, the structure of collagen bundle network became less branchy, collagen fibers merged, their cross section area enlarged.
Tongue Pressure Sensing Array Integrated with a System-on-Chip Embedded in a Mandibular Advancement Splint
Authors: Chen Yun-Ting , Yeh Kun-Ying , Chen Szu-Han , Wang Chuang-Yin , Yeh Chao-Chi , Xu Ming-Xin , Lu Shey-Shi , Chen Yunn-Jy , Yang Yao-Joe
Published: July 2018

Obstructive sleep apnea (OSA), which is caused by obstructions of the upper airway, is a syndrome with rising prevalence. Mandibular advancement splints (MAS) are oral appliances for potential treatment of OSA. This work proposes a highly-sensitive pressure sensing array integrated with a system-on-chip (SoC) embedded in a MAS. The device aims to measure tongue pressure distribution in order to determine the efficacy of the MAS for treating OSA. The flexible sensing array consists of an interdigital electrode pair array assembled with conductive polymer films and an SoC capable of retrieving/storing data during sleep, and transmitting data for analysis after sleep monitoring. The surfaces of the conductive polymer films were patterned with microdomed structures, which effectively increased the sensitivity and reduced the pressure sensing response time. The measured results also show that the crosstalk effect between the sensing elements of the array was negligible. The sensitivity of the sensing array changed minimally after the device was submerged in water for up to 100 h.