bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Molar Furcations on Photodynamic Therapy Outcomes: A 6-Month Split-Mouth Randomized Clinical Trial
Authors: Courval Aymeric , Harmouche Laetitia , Mathieu Anne , Petit Catherine , Huck Olivier , Séverac François , Davideau Jean-Luc
Published: June 2020

The effectiveness of adjunctive photodynamic treatment (PDT) to non-surgical periodontal therapy has been shown to depend on initial periodontal status. As molar furcation involvement impairs healing response to non-surgical periodontal therapy, the aim of this study was to evaluate the impact of furcation involvement on PDT outcomes. Thirty-six patients suffering from severe chronic periodontitis were included in a 6-month split-mouth randomized clinical trial. PDT applications used the toluidine blue O and a light-emitting diode (LED) with a red spectrum. Repeated PDT applications were performed in addition to non-surgical periodontal treatment at baseline and at 3-months. Pocket probing depth (PPD), plaque index, bleeding on probing, and clinical attachment level were recorded at baseline, and again at 3- and 6-months. Furcation sites of molars were compared to other sites of molars and non-molars. Multilevel analysis showed no PDT effect in molar furcation sites while an additional significant reduction (odds ratio = 0.67) of pockets with PPD > 5 mm in other sites at 3-months was measured. PPD reduction appeared delayed in molar furcation sites treated with PDT. There is no additional apparent benefit to use PDT in molar furcation sites for the reduction of pockets with PPD > 5 mm contrary to other sites.
Psychosocial Well-Being of School-Aged Children Born to Bereaved (Shidu) Families: Associations with Mothers’ Quality of Life and Involvement Behaviors
Authors: Cui Ke , Sim Timothy , Xu Ting
Published: June 2020

Parents who lost their only child in the 12 May 2018 Wenchuan earthquake came to be known as the “shidu” (loss of an only child) parents. After the earthquake, they were beneficiaries of free reproductive health services, and most had another child. This study focuses on the psychosocial well-being of those children born to the shidu parents, and explores factors associated with mothers’ quality of life (QoL) and their involvement with their children. A cross-sectional survey was conducted in two primary schools in Wenchuan County. A sample of 192 families was analyzed (147 non-shidu and 45 shidu). The statistical analyses indicated that the children of shidu families had poorer peer relationships than children of non-shidu families. Moreover, shidu mothers’ expectations of their children’s achievements were significantly lower than for non-shidu mothers, but there was no statistically significant difference in the QoL between them. Additionally, a higher home-based involvement of mothers was found to be moderately associated with peer relationship problems of children in shidu families. Therefore, we suggest a future research focus on developing joint activities for parents and children that help to increase emotional communication for the psychosocial development of children in shidu families after disasters in China.
Effects of COVID-19 Infection during Pregnancy and Neonatal Prognosis: What Is the Evidence?
Authors: Lopes de Sousa Álvaro Francisco , Carvalho Herica Emilia Félix de , Oliveira Layze Braz de , Schneider Guilherme , Camargo Emerson Lucas Silva , Watanabe Evandro , de Andrade Denise , Fernandes Ana Fátima Carvalho , Mendes Isabel Amélia Costa , Fronteira Inês
Published: June 2020

Background: This study’s aims are to assess the current evidence presented in the literature regarding the potential risks of COVID-19 infection among pregnant women and consequent fetal transmission. Methods: a systematic literature review assessing papers published in the most comprehensive databases in the field of health intended to answer the question, “What are the effects of COVID-19 infection during pregnancy, and what is the neonatal prognosis?” Results: 49 papers published in 2020 were eligible, presenting low levels of evidence. A total of 755 pregnant women and 598 infants were assessed; more than half of pregnant women had C-sections (379/65%). Only 493 (82%) infants were tested for SARS-CoV-2, nine (2%) of whom tested positive. There is, however, no evidence of vertical transmission based on what has been assessed so far, considering there are knowledge gaps concerning the care provided during and after delivery, as well as a lack of suitable biological samples for testing SARS-CoV-2. Conclusions: We cannot rule out potential worsening of the clinical conditions of pregnant women infected with SARS-CoV-2, whether the infection is associated with comorbidities or not, due to the occurrence of respiratory disorders, cardiac rhythm disturbances, and acid-base imbalance, among others. We recommend relentless monitoring of all pregnant women in addition to testing them before delivery or the first contact with newborns.
Let the Children Listen: A First Approximation to the Sound Environment Assessment of Children through a Soundwalk Approach
Authors: Estévez-Mauriz Laura , Forssén Jens , Zachos Georgios , Kropp Wolfgang
Published: June 2020

The urban sound environment is one of the layers that characterizes a city, and several methodologies are used for its assessment, including the soundwalk approach. However, this approach has been tested mainly with adults. In the work presented here, the aim is to investigate a soundwalk methodology for children, analyzing the sound environment of five different sites of Gothenburg, Sweden, from children’s view-point, giving them the opportunity to take action as an active part of society. Both individual assessment of the sound environment and acoustic data were collected. The findings suggested that among significant results, children tended to rank the sound environment as slightly better when lower levels of background noise were present ( L A 90 ). Moreover, traffic dominance ratings appeared as the best predictor among the studied sound sources: when traffic dominated as a sound source, the children rated the sound environment as less good. Additionally, traffic volume appeared as a plausible predictor for sound environment quality judgments, since the higher the traffic volume, the lower the quality of the sound environment. The incorporation of children into urban sound environment research may be able to generate new results in terms of children’s understanding of their sound environment. Moreover, sound environment policies can be developed from and for children.
Study of Psychomotor Development and Environmental Quality at Shelter Homes for Children Aged 0 to 2 in the Department of Chuquisaca (Bolivia)
Authors: Pérez-De La Cruz Sagrario , Ramírez Ivonne , Maldonado Carolina
Published: June 2020

Children in situations of destitution who become institutionalized commonly display developmental disorders, including delayed growth. The aim was to evaluate the environmental quality of the casas cuna of the Department of Chuquisaca (Plurinational state of Bolivia) in children aged 0 to 2 years old after receiving an early stimulation program based on psychomotor therapy. Thirty-six children who were institutionalized at shelter homes in the Department of Chuquisaca were selected to receive sessions of psychomotricity over a five-month period. The Infant/Toddler Home Observation for Measurement of the Environment (IT-HOME) scale and the Attachment During Stress Scale (ADS) were used. The adult−child relationship with factors of responsiveness (−0.89; p = 0.037), acceptance (0.57; p = 0.024), organization (−1.03; p < 0.001), learning material (−2.57; p < 0.001) and involvement (−1.92; p < 0.001) scored below expectations, showing that environmental indicators are a poor stimulation for children growing up in shelter homes. Improvements were found in the children’s development after receiving this therapy. In conclusion, an early stimulation program based on psychomotor therapy over five months provided favorable results for the acquisition of skills for communication, motor development and social skills, which positively affect the psychomotor development.
Ensemble-Based Online Machine Learning Algorithms for Network Intrusion Detection Systems Using Streaming Data
Authors: Martindale Nathan , Ismail Muhammad , Talbert Douglas A.
Published: June 2020

As new cyberattacks are launched against systems and networks on a daily basis, the ability for network intrusion detection systems to operate efficiently in the big data era has become critically important, particularly as more low-power Internet-of-Things (IoT) devices enter the market. This has motivated research in applying machine learning algorithms that can operate on streams of data, trained online or “live” on only a small amount of data kept in memory at a time, as opposed to the more classical approaches that are trained solely offline on all of the data at once. In this context, one important concept from machine learning for improving detection performance is the idea of “ensembles”, where a collection of machine learning algorithms are combined to compensate for their individual limitations and produce an overall superior algorithm. Unfortunately, existing research lacks proper performance comparison between homogeneous and heterogeneous online ensembles. Hence, this paper investigates several homogeneous and heterogeneous ensembles, proposes three novel online heterogeneous ensembles for intrusion detection, and compares their performance accuracy, run-time complexity, and response to concept drifts. Out of the proposed novel online ensembles, the heterogeneous ensemble consisting of an adaptive random forest of Hoeffding Trees combined with a Hoeffding Adaptive Tree performed the best, by dealing with concept drift in the most effective way. While this scheme is less accurate than a larger size adaptive random forest, it offered a marginally better run-time, which is beneficial for online training.
Proceedings of the 2020 American Bee Research Conference
Authors: Metz Bradley N. , Wu-Smart Judy , Simone-Finstrom Michael
Published: June 2020

The 2020 American Bee Research Conference (ABRC) was held on 9–10 January 2020 in conjunction with the annual convention of the American Beekeeping Federation Conference and Trade Show in Schaumburg, IL. Over the two-day conference, a total of 65 oral and poster presentations were given, representing work done from over 30 different research groups from throughout the United States and Canada. These proceedings contain the submitted abstracts for presentations given at the 2020 American Bee Research Conference.
Effect of Different Combinations of Phosphorus and Nitrogen Fertilization on Arbuscular Mycorrhizal Fungi and Aphids in Wheat
Authors: Wang Chao , Tian Baoliang , Yu Zhenzhen , Ding Jianqing
Published: June 2020

While chemical fertilizers can be used to increase crop yield, the abuse of fertilizers aggravates environmental pollution and soil degradation. Understanding the effects of chemical fertilizers on the interaction between arbuscular mycorrhizal fungi (AMF) and pest insects is of great benefit to crop and environmental protection, because AMF can enhance the nutrition absorption and insect resistance of crops. This study tested the effect of different levels of phosphorus, nitrogen, and their interactions on AMF, secondary metabolites, Sitobion avenae in garden, as well as the wheat traits in field. The results showed that AMF colonization on roots in the P0N1 treatment (0 g P/pot, 1.3083 g N/pot in the garden, and 0 g P/plot, 299.84 g N/plot) was the highest in both the garden and the field. The abundance of aphid was reduced in the P0N1 treatment, and there were negative relationships between aphids and AMF and phenolics, but a positive relationship between AMF and phenolics. Our results indicated that a change in the ratio of phosphorus to nitrogen affects the relationship among AMF, aphid abundance, and metabolites. The results also suggested an approach to save chemical fertilizers that could improve crop health and protect the agroecosystem against pollution at the same time.
Adaptive Probabilistic Flooding for Information Hovering in VANETs
Authors: Xeros Andreas , Saeed Taqwa , Lestas Marios , Andreou Maria , Silva Cristiano M. , Pitsillides Andreas
Published: June 2020

Information hovering is an information dissemination concept over a mobile set of peers which has not been investigated to the extent that other information dissemination paradigms have. It naturally appears in many vehicular network applications where information must be made available to vehicles within a confined geographical area for during some time period. One elementary strategy is to flood the area with data. Even in this case, some vehicles may never receive the content due to potential partitions created by low traffic density. In order to address this issue, in this work we propose a strategy based on epidemic routing in the hovering area, and probabilistic flooding outside it. Vehicles outside the hovering area serve as bridges towards partitions, leading to high reachability. We highlight the adaptive feature of the protocol, where the rebroadcast probability in partitions is adaptively regulated based on estimates of the density of vehicles in the hovering area. The performance of the proposed scheme is evaluated in VISSIM, using as the reference model in all simulation experiments a section of the road network in cities of Washington. The proposed protocol is shown to achieve the set design goals.
Understanding the Mechanism of Recognition of Gab2 by the N-SH2 Domain of SHP2
Authors: Visconti Lorenzo , Malagrinò Francesca , Pagano Livia , Toto Angelo
Published: June 2020

Gab2 is a scaffold protein with a crucial role in colocalizing signaling proteins and it is involved in the regulation of several important molecular pathways. SHP2 is a protein phosphatase that binds, through its two SH2 domains, specific consensus sequences presenting a phosphorylated tyrosine located on the disordered tail of Gab2. To shed light on the details of such a fundamental interaction for the physiology of the cell, we present a complete mutational analysis of the kinetics of binding between the N-SH2 domain of SHP2 and a peptide mimicking a specific region of Gab2. By analyzing kinetic data, we determined structural features of the transition state of the N-SH2 domain binding to Gab2, highlighting a remarkable cooperativity of the binding reaction. Furthermore, comparison of these data with ones previously obtained for another SH2 domain suggests the presence of underlying general features characterizing the binding process of SH2 domains. Data are discussed under the light of previous works on SH2 domains.
Discrete-Time Semi-Markov Random Evolutions in Asymptotic Reduced Random Media with Applications
Authors: Limnios Nikolaos , Swishchuk Anatoliy
Published: June 2020

This paper deals with discrete-time semi-Markov random evolutions (DTSMRE) in reduced random media. The reduction can be done for ergodic and non ergodic media. Asymptotic approximations of random evolutions living in reducible random media (random environment) are obtained. Namely, averaging, diffusion approximation and normal deviation or diffusion approximation with equilibrium by martingale weak convergence method are obtained. Applications of the above results to the additive functionals and dynamical systems in discrete-time produce the above tree types of asymptotic results.
Kidney Transplant in Fabry Disease: A Revision of the Literature
Authors: Capelli Irene , Aiello Valeria , Gasperoni Lorenzo , Comai Giorgia , Corradetti Valeria , Ravaioli Matteo , Biagini Elena , Graziano Claudio , La Manna Gaetano
Published: June 2020

Fabry disease is classified as a rare X-linked disease caused by a complete or partial defect of enzyme alpha-galactosidase, due to GLA gene mutations. This disorder leads to intracellular globotriaosylceramide (Gb3) deposition associated with increased Gb3 plasma levels. Most of the symptoms of the disease, involving kidneys, heart and nervous system, result from this progressive Gb3 deposition. The incidence is estimated in 1/50,000 to 1/117,000 in males. Fabry nephropathy begins with microalbuminuria and/or proteinuria, which, in the classic form, appear from childhood. Thus, a progressive decline of renal function can start at a young age, and evolve to kidney failure, requiring dialysis or renal transplantation. Enzyme replacement therapy (ERT), available since 2001 for Fabry disease, has been increasingly introduced into the clinical practice, with overall positive short-term and long-term effects in terms of ventricular hypertrophy and renal function. Kidney transplantation represents a relevant therapeutic option for Fabry nephropathy management, for patients reaching end-stage renal disease, but little is known about long-term outcomes, overall patient survival or the possible role of ERT after transplant. The purpose of this review is to analyze the literature on every aspect related to kidney transplantation in patients with Fabry nephropathy: from the analysis of transplant outcomes, to the likelihood of disease recurrence, up to the effects of ERT and its possible interference with immunosuppression.
Risk Factors for Delayed Neurocognitive Recovery According to Brain Biomarkers and Cerebral Blood Flow Velocity
Authors: Bukauskienė Rasa , Širvinskas Edmundas , Lenkutis Tadas , Benetis Rimantas , Steponavičiūtė Rasa
Published: June 2020

Background and Objectives: The aim of this study is to identify risk factors for the development of delayed neurocognitive recovery (dNCR). Materials and Methods: 140 patients underwent neurocognitive evaluations (Adenbrooke, MoCa, trial making, and CAM test) and middle cerebral artery (MCA) blood flow velocity (BFV) measurements, one day before cardiac surgery. BFV was re-evaluated after anesthesia induction, before the beginning, middle, end, and after cardiopulmonary bypass (CPB) and postsurgery. To measure glial fibrillary acidic protein (GFAP) and neurofilament heavy chain (Nf-H), blood samples were collected after anesthesia induction, 24 and 48 h after the surgery. Neurocognitive evaluation was repeated 7–10 days after surgery. According to the results, patients were divided into two groups: with dNCR (dNCR group) and without dNCR (non-dNCR group). Results: 101 patients completed participation in this research. GFAP increased in both the non-dNCR group (p < 0.01) and in the dNCR group (p < 0.01), but there was no difference between the groups (after 24 h, p 0.342; after 48 h, p 0.273). Nf-H increased in both groups (p < 0.01), but there was no difference between them (after 24 h, p = 0.240; after 48 h, p = 0.597). MCA BFV was significantly lower in the dNCR group during the bypass (37.13 cm/s SD 7.70 versus 43.40 cm/s SD 9.56; p = 0.001) and after surgery (40.54 cm/s SD 11.21 versus 47.6 cm/s SD 12.01; p = 0.003). Results of neurocognitive tests correlated with CO2 concentration (Pearson’s r 0.40, p < 0.01), hematocrit (r 0.42, p < 0.01), MCA BFV during bypass (r 0.41, p < 0.01), and age (r −0.533, p < 0.01). The probability of developing dNCR increases 1.21 times with every one year of increased age (p < 0.01). The probability of developing dNCR increases 1.07 times with a decrease of BFV within 1 cm/s during bypass (p = 0.02). Conclusion: Risk factors contributing to dNCR among the tested patients were older age and middle cerebral artery blood flow velocity decrease during bypass.
Electrochemical Impedance Spectroscopy for the Measurement of the Corrosion Rate of Magnesium Alloys: Brief Review and Challenges
Authors: Feliu Sebastián
Published: June 2020

From a technological point of view, measurement of the corrosion rate of magnesium (Mg) and its alloys is critical for lifetime predictions of Mg-based structures and for comparative assessments of their corrosion protection ability. Whilst weight loss, hydrogen evolution, and polarization curves methods are frequently used for measuring the corrosion rate, the determination of values by electrochemical impedance spectroscopy (EIS) is relatively scarce and has only been realized recently. This technique seems to be the most suitable for monitoring corrosion rate values due to its “non-destructive” character, its reproducibility, and its reliable determination of small corrosion rates, much lower than those measured by other techniques. This review aims to picture the state-of-the-art technique of using EIS for measuring the corrosion rate of Mg. This paper starts by introducing some fundamental aspects of the most widely used methods for monitoring the corrosion rate of Mg/Mg alloy and continues by briefly explaining some of the fundamental concepts surrounding EIS, which are essential for the user to be able to understand how to interpret the EIS spectra. Lastly, these concepts are applied, and different approaches that have been proposed to obtain quantitative values of corrosion rate since the 1990s are discussed.
{111}<110> Orientation Induced Anisotropy of Shape Memory Effect in NiTiNb Pipe Joints
Authors: Sun Mingyan , Fan Qichao , Wang Yingying , Yang Qin , Chen Jie , Huang Shuke , Zhang Yonghao
Published: June 2020

This work aims to clarify the influence of texture type and intensity on the shape memory effect (SME) in NiTiNb shape memory alloy (SMA) pipe joints, especially revealing the causes for the anisotropy of SME via texture changes. Three NiTiNb rods with different intensities of the {111}<110> texture were fabricated, and their microstructures, crystalline orientation distribution functions and inverse pole figures were obtained by X-ray diffraction and electron backscatter diffraction measurements. Simultaneously, the SME was characterized by inner-diameter recoverability of the corresponding pipe joints. For a given intensity of the {111}<110> texture, the SME of the NiTiNb pipe joints strongly depended on the expansion direction due to {111}<110> orientation-induced anisotropy of SME. In addition, both the SME and anisotropy of NiTiNb pipe joints increased with the increased intensity of the {111}<110> texture. Therefore, a suitable expansion direction and strong texture intensity should be considered for high SME in NiTiNb pipe joints.
Hot Deformation Behavior and Processing Map of High-Strength Nickel Brass
Authors: Liang Qiang , Liu Xin , Li Ping , Zhang Xianming
Published: June 2020

The flow behavior of a new kind of high-strength nickel brass used as automobile synchronizer rings was investigated by hot compression tests with a Gleeble-3500 isothermal simulator at strain rates ranging from 0.01 to 10 s−1 and a wide deformation temperature range of 873–1073K at intervals of 50 K. The experimental results show that flow stress increases with increasing strain rate and decreasing deformation temperature, and discontinuous yielding appeared in the flow stress curves at higher strain rates. A modified Arrhenius constitutive model considering the compensation of strain was established to describe the flow behavior of this alloy. A processing map was also constructed with strain of 0.3, 0.6, and 0.9 based on the obtained experimental flow stress–strain data. In addition, the optical microstructure evolution and its connection with the processing map of compressed specimens are discussed. The predominant deformation mechanism of Cu-Ni-Al brass is dynamic recovery when the deformation temperature is lower than 973 K and dynamic recrystallization when the deformation temperature is higher than 973 K according to optical observation. The processing map provides the optimal hot working temperature and strain rate, which is beneficial in choosing technical parameters for this high-strength alloy.
Discrimination of Object Curvature Based on a Sparse Tactile Sensor Array
Authors: Liu Weiting , Zhan Binpeng , Gu Chunxin , Yu Ping , Zhang Guoshi , Fu Xin , Cipriani Christian , Hu Liang
Published: June 2020

Object curvature plays an important role in grasping and manipulation. To be more exact, local curvature is a more useful information for grasping practically. Vision and touch are the two main methods to extract surface curvature of an object, but vision is often limited since the complete contact area is invisible during manipulation. In this paper, the authors propose an object curvature estimation method based on an artificial neural network algorithm through a lab-developed sparse tactile sensor array. The compliant layer covering on the sensor is indispensable for fitting the curved surface. Three types (plane, convex sphere, and convex cylinder) of sample and each type of sample including 30 different radiuses (1 mm to 30 mm) were used in the experiment. The overall classification accuracy was 93.1%. The average curvature radius estimating error based on an artificial neural network (ANN) algorithm was 1.87 mm. When the radius of curvature was bigger than 5 mm, the average relative error was smaller than 20%. As a comparison, the sensor array density we used in this paper was less than 9/cm2, which was smaller than the density of human SAII receptors, but the discrimination result was close to the SAII receptors. Comparison with the curvature discrimination ability of the human body showed that this method has a promising application prospect.
Changes in the Microbiome of Cryptosporidium-Infected Mice Correlate to Differences in Susceptibility and Infection Levels
Authors: Charania Raheela , Wade Brandy E. , McNair Nina N. , Mead Jan R.
Published: June 2020

Cryptosporidium spp. are opportunistic protozoan parasites that infect epithelial cells of the small intestine, causing diarrheal illness in humans. Differences in severity may be due to the immunological status of the host, malnutrition or prior exposure but may also be due to differences in the host gut flora. We examined changes in bacterial flora following antibiotic treatment to determine how cryptosporidial infections and gut integrity were affected by alterations in the microbiome. DNA was extracted from fecal and intestinal samples during peak infection. V4 region amplicons were generated and sequenced using 16sRNA on an Illumina MiSeq. Species evenness and richness were estimated using the Shannon diversity index. There was a significant decrease in anaerobes and overgrowth of Enterobacteriaceae in mice treated with cloxacillin. We also examined levels of short-chain fatty acids in fecal samples. There was a significant decrease in acetate, propionate, and butyrate in these same mice. Concurrent with the shift in bacterial infection was a significant increase in severity of cryptosporidial infection and increase in gut permeability. Treatment with other antibiotics significantly altered the microbiome but did not change the infection, suggesting that specific alterations in the host microbiome allow for more favorable growth of the parasite.
Thermotolerant and Thermophilic Mycobiota in Different Steps of Compost Maturation
Authors: Di Piazza Simone , Houbraken Jos , Meijer Martin , Cecchi Grazia , Kraak Bart , Rosa Ester , Zotti Mirca
Published: June 2020

Composting is a complex process in which various micro-organisms, mainly fungi and bacteria, are involved. The process depends on a large number of factors (biological, chemical, and physical) among which microbial populations play a fundamental role. The high temperatures that occur during the composting process indicate the presence of thermotolerant and thermophilic micro-organisms that are key for the optimization of the process. However, the same micro-organisms can be harmful (allergenic, pathogenic) for workers that handle large quantities of material in the plant, and for end users, for example, in the indoor environment (e.g., pots in houses and offices). Accurate knowledge of thermotolerant and thermophilic organisms present during the composting stages is required to find key organisms to improve the process and estimate potential health risks. The objective of the present work was to study thermotolerant and thermophilic mycobiota at different time points of compost maturation. Fungi were isolated at four temperatures (25, 37, 45, and 50 °C) from compost samples collected at five different steps during a 21-day compost-maturation period in an active composting plant in Liguria (northwestern Italy). The samples were subsequently plated on three different media. Our results showed a high presence of fungi with an order of magnitude ranging from 1 × 104 to 3 × 105 colony-forming units (CFU) g−1. The isolated strains, identified by means of specific molecular tools (ITS, beta-tubulin, calmodulin, elongation factor 1-alpha, and LSU sequencing), belonged to 45 different species. Several thermophilic species belonging to genera Thermoascus and Thermomyces were detected, which could be key during composting. Moreover, the presence of several potentially harmful fungal species, such as Aspergillus fumigatus, A. terreus, and Scedosporium apiospermum, were found during the whole process, including the final product. Results highlighted the importance of surveying the mycobiota involved in the composting process in order to: (i) find solutions to improve efficiency and (ii) reduce health risks.
Genetic Diversity of Australian Bacillus anthracis Isolates Revealed by Multiple-Locus Variable-Number Tandem Repeat Analysis
Authors: Muller Janine , Mohammad Ilhan , Warner Simone , Paskin Roger , Constable Fiona , Fegan Mark
Published: June 2020

Outbreaks of anthrax occur sporadically in Australia and most commonly in the “anthrax belt”, a region which extends from southern Queensland through the centre of New South Wales and into northern Victoria. Little is known about the epidemiological links between Bacillus anthracis isolates taken from different outbreaks and the diversity of strains within Australia. We used multiple-locus variable-number tandem repeat analysis employing 25 markers (MLVA25) to genotype 99 B. anthracis isolates from an archival collection of Australian isolates. MLVA25 genotyping revealed eight unique genotypes which clustered within the previously defined A3 genotype of B. anthracis. Genotyping of B. anthracis strains from outbreaks of disease in Victoria identified the presence of multiple genotypes associated with these outbreaks. The geographical distribution of genotypes within Australia suggests that a single genotype was introduced into the eastern states of Australia, followed by the spread and localised differentiation of the pathogen (MLVA25 genotypes MG1-MG6) throughout the anthrax belt. In contrast, unexplained occurrences of disease in areas outside of this anthrax belt which are associated with different genotypes, (MLVA25 genotypes MG7 and MG8) indicate separate introductions of B. anthracis into Australia.
Biochemical and Genetic Analysis of 4-Hydroxypyridine Catabolism in Arthrobacter sp. Strain IN13
Authors: Vaitekūnas Justas , Gasparavičiūtė Renata , Stankevičiūtė Jonita , Urbelis Gintaras , Meškys Rolandas
Published: June 2020

N-Heterocyclic compounds are widely spread in the biosphere, being constituents of alkaloids, cofactors, allelochemicals, and artificial substances. However, the fate of such compounds including a catabolism of hydroxylated pyridines is not yet fully understood. Arthrobacter sp. IN13 is capable of using 4-hydroxypyridine as a sole source of carbon and energy. Three substrate-inducible proteins were detected by comparing protein expression profiles, and peptide mass fingerprinting was performed using MS/MS. After partial sequencing of the genome, we were able to locate genes encoding 4-hydroxypyridine-inducible proteins and identify the kpi gene cluster consisting of 16 open reading frames. The recombinant expression of genes from this locus in Escherichia coli and Rhodococcus erytropolis SQ1 allowed an elucidation of the biochemical functions of the proteins. We report that in Arthrobacter sp. IN13, the initial hydroxylation of 4-hydroxypyridine is catalyzed by a flavin-dependent monooxygenase (KpiA). A product of the monooxygenase reaction is identified as 3,4-dihydroxypyridine, and a subsequent oxidative opening of the ring is performed by a hypothetical amidohydrolase (KpiC). The 3-(N-formyl)-formiminopyruvate formed in this reaction is further converted by KpiB hydrolase to 3-formylpyruvate. Thus, the degradation of 4-hydroxypyridine in Arthrobacter sp. IN13 was analyzed at genetic and biochemical levels, elucidating this catabolic pathway.
Magnetic Heating of Nanoparticles Applied in the Synthesis of a Magnetically Recyclable Hydrogenation Nanocatalyst
Authors: Gyergyek Sašo , Lisjak Darja , Beković Miloš , Grilc Miha , Likozar Blaž , Nečemer Marijan , Makovec Darko
Published: June 2020

Utilization of magnetic nanoparticle-mediated conversion of electromagnetic energy into heat is gaining attention in catalysis as a source of heat needed for a substrate’s chemical reaction (electrification of chemical conversions). We demonstrate that rapid and selective heating of magnetic nanoparticles opens a way to the rapid synthesis of a nanocatalyst. Magnetic heating caused rapid reduction of Ru3+ cations in the vicinity of the support material and enabled preparation of a Ru nanoparticle-bearing nanocatalyst. Comparative synthesis conducted under conventional heating revealed significantly faster Ru3+ reduction under magnetic heating. The faster kinetic was ascribed to the higher surface temperature of the support material caused by rapid magnetic heating. The nanocatalyst was rigorously tested in the hydrotreatment of furfural. The activity, selectivity and stability for furfural hydrogenation to furfuryl alcohol, a valuable biobased monomer, remained high even after four magnetic recycles.
Nanocomposites with p- and n-Type Conductivity Controlled by Type and Content of Nanotubes in Thermosets for Thermoelectric Applications
Authors: Kröning Katharina , Krause Beate , Pötschke Petra , Fiedler Bodo
Published: June 2020

In this work, composites based on epoxy resin and various carbon nanotubes (CNTs) were studied regarding their thermoelectric properties. The epoxy composites were prepared by infiltration of preformed CNT buckypapers. The influence of different types of CNTs on the Seebeck coefficient was investigated, namely lab-made and commercially available multi walled carbon nanotubes (MWCNTs), lab-made nitrogen doped MWCNTs (N-MWCNT) and commercially available single walled carbon nanotubes (SWCNTs). It was found that only by varying the lab-made MWCNT content could both n- and p-type composites be produced with Seebeck coefficients between −9.5 and 3.1 µV/K. The incorporation of N-MWCNTs resulted in negative Seebeck coefficients of −11.4 to −17.4 µV/K. Thus, the Seebeck coefficient of pure SWCNT changed from 37.4 to −25.5 µV/K in the epoxy/1 wt. % SWCNT composite. A possible explanation for the shift in the Seebeck coefficient is the change of the CNTs Fermi level depending on the number of epoxy molecules on the CNT surface.
Quadratic Meta-Reflectors Made of HfO2 Nanopillars with a Large Field of View at Infrared Wavelengths
Authors: Tang Feng , Ye Xin , Li Qingzhi , Li Hailiang , Yu Haichao , Wu Weidong , Li Bo , Zheng Wanguo
Published: June 2020

Metasurfaces, being composed of subwavelength nanostructures, can achieve peculiar optical manipulations of phase, amplitude, etc. A large field of view (FOV) is always one of the most desirable characteristics of optical systems. In this study, metasurface-based quadratic reflectors (i.e., meta-reflectors) made of HfO2 nanopillars are investigated to realize a large FOV at infrared wavelengths. First, the geometrical dependence of HfO2 nanopillars’ phase difference is analyzed to show the general principles of designing infrared HfO2 metasurfaces. Then, two meta-reflectors with a quadratic phase profile are investigated to show their large FOV, subwavelength resolution, and long focal depth. Furthermore, the two quadratic reflectors also show a large FOV when deflecting a laser beam with a deflecting-angle range of approximately ±80°. This study presents a flat optical metamaterial with a large FOV for imaging and deflecting, which can greatly simplify the optical–mechanical complexity of infrared systems, particularly with potential applications in high-power optical systems.
Understanding Magnetization Dynamics of a Magnetic Nanoparticle with a Disordered Shell Using Micromagnetic Simulations
Authors: Aurélio David , Vejpravova Jana
Published: June 2020

Spin disorder effects influence magnetization dynamics and equilibrium magnetic properties of real nanoparticles (NPs). In this work, we use micromagnetic simulations to try to better understand these effects, in particular, on how the magnetization reversal is projected in the character of the hysteresis loops at different temperatures. In our simulation study, we consider a prototype NP adopting a magnetic core-shell model, with magnetically coherent core and somewhat disordered shell, as it is one of the common spin architectures in real NPs. The size of the core is fixed to 5.5 nm in diameter and the shell thickness ranges from 0.5 nm to 3 nm. As a starting point in the simulations, we used typical experimental values obtained for a cobalt ferrite NP of a comparable size investigated previously. The simulations enabled us to study systematically the macrospin dynamics of the prototype NP and to address the interplay between the magnetic anisotropies of the core and the shell, respectively. We also demonstrate how the computational time step, run time, damping parameter, and thermal field influence the simulation results. In agreement with experimental studies, we observed that the direction and magnitude of the shell anisotropy influences the effective magnetic size of the core in the applied magnetic field. We conclude that micromagnetic simulations, in spite of being designed for much larger scales are a useful toolbox for understanding the magnetization processes within a single domain NP with an ordered spin structure in the core and partially disordered spins in the shell.
Hydroxyapatite Surfaces Functionalized with a Self-Assembling Peptide: XPS, RAIRS and NEXAFS Study
Authors: Secchi Valeria , Franchi Stefano , Dettin Monica , Zamuner Annj , Beranová Klára , Vladescu Alina , Battocchio Chiara , Graziani Valerio , Tortora Luca , Iucci Giovanna
Published: June 2020

Hydroxyapatite (HAP) coatings can improve the biocompatibility and bioactivity of titanium alloys, such as Ti6Al4V, commonly used as material for orthopedic prostheses. In this framework, we have studied the surface of HAP coatings enriched with Mg and either Si or Ti deposited by RF magnetron sputtering on Ti6Al4V. HAP coatings have been furtherly functionalized by adsorption of a self-assembling peptide (SAP) on the HAP surface, with the aim of increasing the material bioactivity. The selected SAP (peptide sequence AbuEAbuEAbuKAbuKAbuEAbuEAbuKAbuK) is a self-complementary oligopeptide able to generate extended ordered structures by self-assembling in watery solutions. Samples were prepared by incubation of the HAP coatings in SAP solutions and subsequently analyzed by X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopies, in order to determine the amount of adsorbed peptide, the peptide stability and the structure of the peptide overlayer on the HAP coatings as a function of the HAP substrate and of the pH of the mother SAP solution. Experimental data yielded evidence of SAP adsorption on the HAP surface, and peptide overlayers showed ordered structure and molecular orientation. The thickness of the SAP overlayer depends on the composition of the HAP coating.
Amphotericin B Loaded Polymeric Nanoparticles for Treatment of Leishmania Infections
Authors: Saqib Mudassara , Ali Bhatti A. Shabbir , Ahmad Nasir M. , Ahmed Naveed , Shahnaz Gul , Lebaz Noureddine , Elaissari Abdelhamid
Published: June 2020

Fungal infections in immune-compromised patients are an important cause of mortality and morbidity. Amphotericin B (Amp B) is considered a powerful fungicidal drug but its clinical usage has certain limitations when administered intravenously due to its toxicity and poor solubility. In consideration of such challenges, in cutaneous leishmaniasis, the topical application of Amp B can be a safer option in many aspects. Thus, herein, biopolymer of polycaprolactone (PCL) nanoparticles (NPs) were developed with the loading of Amp B by nanoprecipitation for the treatment of topical leishmanial infections. Various parameters, such as concentration of PCL and surfactant Poloxamer 407, were varied in order to optimize the formation of nanoparticles for the loading of Amp B. The optimized formulation exhibited a mean hydrodynamic particle size of 183 nm with a spherical morphology and an encapsulation efficiency of 85%. The applications of various kinetic models reveal that drug release from nanoformulation follows Korsmeyer–Peppas kinetics and has a high diffusion exponent at a physiological pH of 7.4 as well a skin relevant pH = 5.5. The activity of the prepared nanoparticles was also demonstrated in Leishmania infected macrophages. The measured IC50 of the prepared nanoparticle formulation was observed to be significantly lower when compared to control free Amp B and AmBisome® for both L. tropica KWH23 and L. donovani amastigotes in order to demonstrate maximum parasite inhibition. The prepared topical nanoformulations are capable of providing novel options for the treatment of leishmaniasis, which can be possible after in vivo assays as well as the establishment of safety profiles.
How Does a Tumor Get Its Shape? MicroRNAs Act as Morphogens at the Cancer Invasion Front
Authors: Vasilescu Catalin , Tanase Mihai , Giza Dana , Procopiuc Livia , Dragomir Mihnea P. , Calin George A.
Published: June 2020

The generation and organization of the invasion front shape of neoplasms is an intriguing problem. The intimate mechanism is not yet understood, but the prevailing theory is that it represents an example of morphogenesis. Morphogenesis requires the presence of specific molecules, known as morphogens (activators and inhibitors), which can diffuse and elicit dose-dependent responses in their target cells. Due to their ability to modulate most of the coding transcriptome, their well-established role in embryogenesis, and their capacity to rapidly move between neighboring and distant cells, we propose microRNAs as inhibitors that could shape the cancer invasion front. In order to explain the genesis of the tumor border, we use Alan Turing’s reaction diffusion model, refined by Meinhardt and Gierer. This assumes the existence of an activator called a, and an inhibitor called h, which we hypothesize could be a freely moving microRNA. We used the fractal dimension as a measure of tumor border irregularity. We observed that the change in fractal dimension associates with variations in the diffusion coefficient of the activator (Da) or the inhibitor (Dh). We determined that the fractal dimension remains constant (i.e., the irregularity of the tumor border does not change) across a Dh interval, which becomes narrower as Da rises. We therefore conclude that a change in fractal dimension occurs when the balance between Da and Dh is disrupted. Biologically, this could be explained by a faulty distribution of the inhibitor caused by an abnormal density of the intercellular connection network. From a translational perspective, if experimentally confirmed, our observations can be used for a better diagnosis of cancer aggressiveness.
Improvement in Healthy Meal Index, Lunch Quality, and Diversity Scores Following an Integrated Nutritional Intervention in a Communal Dining Room: The NEKST Study
Authors: Katz-Shufan Ofira , Simon-Tuval Tzahit , Sabag Liron , R. Shahar Danit
Published: June 2020

The objective of the NEKST (Nutrition Environmental Kibbutzim Study), a nonrandomized interventional study, was to evaluate the effect of an integrated intervention program on participants’ lunch quality and diversity in two communal dining rooms (intervention n = 58 vs. control n = 54). The intervention included recipe modification, environmental changes, and an education program. The outcomes included simple healthy meal index (SHMI), lunch quality (LQS), and diversity scores (LDS) calculated based on photographs of lunch trays. A nutrition questionnaire assessed the changes in fruit and vegetable intake at baseline and 3 months following the intervention. The mean SHMI, LQS, and LDS increased in the intervention group (0.51, p < 0.001; 0.27, p = 0.045; 0.95, p < 0.001, respectively) but not in the control group (p = 0.865; p = 0.339; p = 0.354, respectively). Multivariable linear models demonstrate an increase in the SHMI (β = 0.26, 95% CI [0.12–0.76], p = 0.015), LQS (β = 0.23, 95% CI [0.06–0.83], p = 0.024), and LDS (β = 0.34, 95% CI [0.41–1.39], p < 0.001) of the participants in the intervention group. More participants in the intervention group raised their daily fruit intake compared with the control. We conclude that this integrated intervention program was effective in improving lunch healthy meal index, quality, and diversity in a communal dining room, with a modest halo effect of the intervention throughout the day.
Fetal–Maternal Exposure to Endocrine Disruptors: Correlation with Diet Intake and Pregnancy Outcomes
Authors: Rolfo Alessandro , Nuzzo Anna Maria , De Amicis Ramona , Moretti Laura , Bertoli Simona , Leone Alessandro
Published: June 2020

Endocrine-disrupting chemicals (EDCs) are exogenous substances able to mimic or to interfere with the endocrine system, thus altering key biological processes such as organ development, reproduction, immunity, metabolism and behavior. High concentrations of EDCs are found in several everyday products including plastic bottles and food containers and they could be easily absorbed by dietary intake. In recent years, considerable interest has been raised regarding the biological effects of EDCs, particularly Bisphenol A (BPA) and phthalates, on human pregnancy and fetal development. Several evidence obtained on in vitro and animal models as well as by epidemiologic and population studies strongly indicated that endocrine disruptors could negatively impact fetal and placental health by interfering with the embryonic developing epigenome, thus establishing disease paths into adulthood. Moreover, EDCs could cause and/or contribute to the onset of severe gestational conditions as Preeclampsia (PE), Fetal Growth Restriction (FGR) and gestational diabetes in pregnancy, as well as obesity, diabetes and cardiovascular complications in reproductive age. Therefore, despite contrasting data being present in the literature, endocrine disruptors must be considered as a therapeutic target. Future actions aimed at reducing or eliminating EDC exposure during the perinatal period are mandatory to guarantee pregnancy success and preserve fetal and adult health.