bluuebunny/crossref_metadata_2025 huggingface dataset:
Group and Child–Family Migration from Central America to the United States: Forced Child–Family Separation, Reunification, and Pseudo Adoption in the Era of Globalization
Authors: Monico Carmen , Mendez-Sandoval Jovani
Published: December 2019

Intercountry adoption from Latin America became a sizable, “quiet” migration to the U.S., as evident in its historical evolution from El Salvador, Guatemala, and Honduras. The recent migration of unaccompanied minors and families traveling with children from these case countries has been characterized by child–family separation, prolonged detention and institutionalization of children, and adoption through various means. This study has been concerned with how both trends became intertwined in the era of globalisation. To address this question, the authors examined intercountry adoption literature and migration-related briefs, legal claims, and news reports. The study suggests that internationally recognized child rights have been violated in the border crisis. Forced family separation resulting from stricter immigration measures has met criteria for child abduction, violating international convention protecting families in transnational kinship and adoption. A child–family separation typology was inferred from individual case studies ranging from separation by death to prolonged or indefinitive separation to de facto adoption. Reunification has failed for migrant children in custody since relatives or kinship members may be undocumented or parents may be deported. The current immigration system for migrant children’s care only prolongs their detention and violates their human and civil rights while turning child abduction into de facto adoption.
Transcriptome Meta-Analysis Deciphers a Dysregulation in Immune Response-Associated Gene Signatures during Sepsis
Authors: Ahmad Shaniya , Singh Prithvi , Sharma Archana , Arora Shweta , Shriwash Nitesh , Rahmani Arshad Husain , Almatroodi Saleh A. , Manda Kailash , Dohare Ravins , Syed Mansoor Ali
Published: December 2019

Sepsis is a life-threatening disease induced by a systemic inflammatory response, which leads to organ dysfunction and mortality. In sepsis, the host immune response is depressed and unable to cope with infection; no drug is currently available to treat this. The lungs are frequently the starting point for sepsis. This study aimed to identify potential genes for diagnostics and therapeutic purposes in sepsis by a comprehensive bioinformatics analysis. Our criteria are to unravel sepsis-associated signature genes from gene expression datasets. Differentially expressed genes (DEGs) were identified from samples of sepsis patients using a meta-analysis and then further subjected to functional enrichment and protein‒protein interaction (PPI) network analysis for examining their potential functions. Finally, the expression of the topmost upregulated genes (ARG1, IL1R2, ELANE, MMP9) was quantified by reverse transcriptase-PCR (RT-PCR), and myeloperoxidase (MPO) expression was confirmed by immunohistochemistry (IHC) staining in the lungs of a well-established sepsis mouse model. We found that all the four genes were upregulated in semiquantitative RT-PCR studies; however, MMP9 showed a nonsignificant increase in expression. MPO staining showed strong immunoreactivity in sepsis as compared to the control. This study demonstrates the role of significant and widespread immune activation (IL1R2, MMP9), along with oxidative stress (ARG1) and the recruitment of neutrophils, in sepsis (ELANE, MPO).
Genomic Diversity of Common Sequence Types of Listeria monocytogenes Isolated from Ready-to-Eat Products of Animal Origin in South Africa
Authors: Matle Itumeleng , Pierneef Rian , Mbatha Khanyisile R. , Magwedere Kudakwashe , Madoroba Evelyn
Published: December 2019

Listeria monocytogenes is a highly fatal foodborne causative agent that has been implicated in numerous outbreaks and related deaths of listeriosis in the world. In this study, six L. monocytogenes isolated from ready-to-eat (RTE) meat products were analysed using Whole Genome Sequencing (WGS) to identify virulence and resistance genes, prophage sequences, PCR-serogroups, and sequence types (STs). The WGS identified four different STs (ST1, ST121, ST204, and ST876) that belonged to serogroup 4b (lineage I) and 1/2a (lineage II). Core genome, and average nucleotide identity (ANI) phylogenetic analyses showed that the majority of strains from serogroup 4b (lineage I) clustered together. However, two isolates that belong to serogroup 1/2a (lineage II) grouped far from each other and the other strains. Examination of reference-guided scaffolds for the presence of prophages using the PHAge Search Tool Enhanced Release (PHASTER) software identified 24 diverse prophages, which were either intact or incomplete/questionable. The National Center for Biotechnology Information- Nucleotide Basic Local Alignment Search Tool (NCBI-BLASTn) revealed that Listeria monocytogenes strains in this study shared some known major virulence genes that are encoded in Listeria pathogenicity islands 1 and 3. In general, the resistance profiles for all the isolates were similar and encoded for multidrug, heavy metal, antibiotic, and sanitizer resistance genes. All the isolates in this study possessed genes that code for resistance to common food processing antiseptics such as Benzalkonium chloride.
AMH: Could It Be Used as A Biomarker for Fertility and Superovulation in Domestic Animals?
Authors: Umer Saqib , Zhao Shan Jiang , Sammad Abdul , Weldegebriall Sahlu Bahlibi , Pang YunWei , Zhu Huabin
Published: December 2019

Anti-Müllerian hormone (AMH) is a reliable and easily detectable reproductive marker for the fertility competence of many farm animal species. AMH is also a good predictor of superovulation in cattle, sheep, and mares. In this review, we have summarized the recent findings related to AMH and its predictive reliability related to fertility and superovulation in domestic animals, especially in cattle. We focused on: (1) the dynamics of AMH level from infancy to prepubescence as well as during puberty and adulthood; (2) AMH as a predictor of fertility; (3) the association between antral follicle count (AFC) and plasma AMH level; (4) AMH as a predictor of superovulation; and (5) factors affecting AMH levels in domestic animals, especially cattle. Many factors affect the circulatory levels of AMH when considering the plasma, like nutrition, activity of granulosa cells, disease state and endocrine disruptions during fetal life. Briefly, we concluded that AMH concentrations are static within individuals, and collection of a single dose of blood has become more popular in the field of assisted reproductive technologies (ART). It may act as a potential predictor of fertility, superovulation, and ovarian disorders in domestic animals. However, due to the limited research in domestic animals, this potential of AMH remains underutilized.
Conversion of DNA Sequences: From a Transposable Element to a Tandem Repeat or to a Gene
Authors: Paço Ana , Freitas Renata , Vieira-da-Silva Ana
Published: December 2019

Eukaryotic genomes are rich in repetitive DNA sequences grouped in two classes regarding their genomic organization: tandem repeats and dispersed repeats. In tandem repeats, copies of a short DNA sequence are positioned one after another within the genome, while in dispersed repeats, these copies are randomly distributed. In this review we provide evidence that both tandem and dispersed repeats can have a similar organization, which leads us to suggest an update to their classification based on the sequence features, concretely regarding the presence or absence of retrotransposons/transposon specific domains. In addition, we analyze several studies that show that a repetitive element can be remodeled into repetitive non-coding or coding sequences, suggesting (1) an evolutionary relationship among DNA sequences, and (2) that the evolution of the genomes involved frequent repetitive sequence reshuffling, a process that we have designated as a “DNA remodeling mechanism”. The alternative classification of the repetitive DNA sequences here proposed will provide a novel theoretical framework that recognizes the importance of DNA remodeling for the evolution and plasticity of eukaryotic genomes.
Water, Hydrous Melting, and Teleseismic Signature of the Mantle Transition Zone
Authors: Fomin Ilya , Schiffer Christian
Published: December 2019

Recent geophysical and petrological observations indicate the presence of water and hydrous melts in and around the mantle transition zone (MTZ), for example, prominent low-velocity zones detected by seismological methods. Experimental data and computational predictions describe the influence of water on elastic properties of mantle minerals. Using thermodynamic relationships and published databases, we calculated seismic velocities and densities of mantle rocks in and around the MTZ in the presence of water for a plausible range of mantle potential temperatures. We then computed synthetic receiver functions to explore the influence of different water distribution patterns on the teleseismic signature. The results may improve our understanding and interpretation of seismic observations of the MTZ.
Antarctic Sea Ice Proxies from Marine and Ice Core Archives Suitable for Reconstructing Sea Ice over the Past 2000 Years
Authors: Thomas Elizabeth R. , Allen Claire S. , Etourneau Johan , King Amy C. F. , Severi Mirko , Winton V. Holly L. , Mueller Juliane , Crosta Xavier , Peck Victoria L.
Published: December 2019

Dramatic changes in sea ice have been observed in both poles in recent decades. However, the observational period for sea ice is short, and the climate models tasked with predicting future change in sea ice struggle to capture the current Antarctic trends. Paleoclimate archives, from marine sedimentary records and coastal Antarctic ice cores, provide a means of understanding sea ice variability and its drivers over decadal to centennial timescales. In this study, we collate published records of Antarctic sea ice over the past 2000 years (2 ka). We evaluate the current proxies and explore the potential of combining marine and ice core records to produce multi-archive reconstructions. Despite identifying 92 sea ice reconstructions, the spatial and temporal resolution is only sufficient to reconstruct circum-Antarctic sea ice during the 20th century, not the full 2 ka. Our synthesis reveals a 90 year trend of increasing sea ice in the Ross Sea and declining sea ice in the Bellingshausen, comparable with observed trends since 1979. Reconstructions in the Weddell Sea, the Western Pacific and the Indian Ocean reveal small negative trends in sea ice during the 20th century (1900–1990), in contrast to the observed sea ice expansion in these regions since 1979.
The Carbon-Isotope Record of the Sub-Seafloor Biosphere
Authors: Meister Patrick , Reyes Carolina
Published: December 2019

Sub-seafloor microbial environments exhibit large carbon-isotope fractionation effects as a result of microbial enzymatic reactions. Isotopically light, dissolved inorganic carbon (DIC) derived from organic carbon is commonly released into the interstitial water due to microbial dissimilatory processes prevailing in the sub-surface biosphere. Much stronger carbon-isotope fractionation occurs, however, during methanogenesis, whereby methane is depleted in 13C and, by mass balance, DIC is enriched in 13C, such that isotopic distributions are predominantly influenced by microbial metabolisms involving methane. Methane metabolisms are essentially mediated through a single enzymatic pathway in both Archaea and Bacteria, the Wood–Ljungdahl (WL) pathway, but it remains unclear where in the pathway carbon-isotope fractionation occurs. While it is generally assumed that fractionation arises from kinetic effects of enzymatic reactions, it has recently been suggested that partial carbon-isotope equilibration occurs within the pathway of anaerobic methane oxidation. Equilibrium fractionation might also occur during methanogenesis, as the isotopic difference between DIC and methane is commonly on the order of 75‰, which is near the thermodynamic equilibrium. The isotopic signature in DIC and methane highly varies in marine porewaters, reflecting the distribution of different microbial metabolisms contributing to DIC. If carbon isotopes are preserved in diagenetic carbonates, they may provide a powerful biosignature for the conditions in the deep biosphere, specifically in proximity to the sulphate–methane transition zone. Large variations in isotopic signatures in diagenetic archives have been found that document dramatic changes in sub-seafloor biosphere activity over geological time scales. We present a brief overview on carbon isotopes, including microbial fractionation mechanisms, transport effects, preservation in diagenetic carbonate archives, and their implications for the past sub-seafloor biosphere and its role in the global carbon cycle. We discuss open questions and future potentials of carbon isotopes as archives to trace the deep biosphere through time.
Improved Wellbeing for Both Caretakers and Users from A Zoo-Related Nature Based Intervention—A Study at Nordens Ark Zoo, Sweden
Authors: Sahlin Eva , Johansson Björn , Karlsson Per-Olof , Loberg Jenny , Niklasson Mats , Grahn Patrik
Published: December 2019

Nature-based interventions have been proposed to promote physical and mental health and give stress reduction. Little attention has been given to the potential of zoos for human health and wellbeing. A disadvantaged group in Sweden regarding access to nature are individuals with disabilities who consequently do not have the same access to these health benefits as other groups. To increase awareness and knowledge regarding spending time in nature and with animals, courses directed at caretakers for persons with disabilities and their users were held at Nordens Ark, a zoo in Sweden. To explore if the courses had led to increased nature activities, and if participating in the courses had affected caretakers’ and their users’ health and wellbeing, questionnaires and interviews for evaluating the courses were used. The results showed improved quality in nature visits because of course participation as well as positive effects for the wellbeing, sustainability for the caregivers and users in their working lives, and relationships were positively affected. The conclusion from this study is that nature and animal-based education should be more frequent to provide opportunities for a disadvantaged group to have the positive effects of nature of which most other groups have obvious access to.
Types of Crime, Poverty, Population Density and Presence of Police in the Metropolitan District of Quito
Authors: Cabrera-Barona Pablo F. , Jimenez Gualdemar , Melo Pablo
Published: December 2019

This exploratory study identifies spatial patterns of crimes and their associations with the index of Unsatisfied Basic Needs (UBN), with Communitarian Policy Units (CPU) density, as well as with population density. The case study is the Metropolitan District of Quito. Correlation analyses were applied between number of registers of each type of crime, and the UBN index, CPU density and population density measures. The spatial autocorrelation index of Getis-Ord Gi* was calculated to identify hotspots of the different types of crime. Ordinary least squares regressions and geographically weighted regressions considering types of crime as dependent variables, were calculated. Larceny and robbery were found to be the predominant crimes in the study area. An inverse relationship between the UBN index and number of crimes was identified for each type of crime, while positive relationships were found between crimes and CPU density, and between crimes and population density. Significant hotspots of fraud, homicide, larceny, murder, rape and robbery were found in all urban parishes. Additionally, crime hotspots were identified in eastern rural parishes adjacent to urban parishes. This study provides important implications for crime prevention in the Metropolitan District of Quito (MDQ), and the obtained results contribute to the ecology of crime research in the study area.
Visualization of Pedestrian Density Dynamics Using Data Extracted from Public Webcams
Authors: Petrasova Anna , Hipp J. Aaron , Mitasova Helena
Published: December 2019

Accurate information on the number and distribution of pedestrians in space and time helps urban planners maintain current city infrastructure and design better public spaces for local residents and visitors. Previous studies have demonstrated that using webcams together with crowdsourcing platforms to locate pedestrians in the captured images is a promising technique for analyzing pedestrian activity. However, it is challenging to efficiently transform the time series of pedestrian locations in the images to information suitable for geospatial analytics, as well as visualize data in a meaningful way to inform urban design or decision making. In this study, we propose to use a space-time cube (STC) representation of pedestrian data to analyze the spatio-temporal patterns of pedestrians in public spaces. We take advantage of AMOS (The Archive of Many Outdoor Scenes), a large database of images captured by thousands of publicly available, outdoor webcams. We developed a method to obtain georeferenced spatio-temporal data from webcams and to transform them into high-resolution continuous representation of pedestrian densities by combining bivariate kernel density estimation with trivariate, spatio-temporal spline interpolation. We demonstrate our method on two case studies analyzing pedestrian activity of two city plazas. The first case study explores daily and weekly spatio-temporal patterns of pedestrian activity while the second one highlights the differences in pattern before and after plaza’s redevelopment. While STC has already been used to visualize urban dynamics, this is the first study analyzing the evolution of pedestrian density based on crowdsourced time series of pedestrian occurrences captured by webcam images.
The Association between Virus Prevalence and Intercolonial Aggression Levels in the Yellow Crazy Ant, Anoplolepis Gracilipes (Jerdon)
Authors: Hsu Hung-Wei , Chiu Ming-Chung , Lee Ching-Chen , Lee Chow-Yang , Yang Chin-Cheng Scotty
Published: December 2019

The recent discovery of multiple viruses in ants, along with the widespread infection of their hosts across geographic ranges, provides an excellent opportunity to test whether viral prevalence in the field is associated with the complexity of social interactions in the ant population. In this study, we examined whether the association exists between the field prevalence of a virus and the intercolonial aggression of its ant host, using the yellow crazy ant (Anoplolepis gracilipes) and its natural viral pathogen (TR44839 virus) as a model system. We delimitated the colony boundary and composition of A. gracilipes in a total of 12 study sites in Japan (Okinawa), Taiwan, and Malaysia (Penang), through intercolonial aggression assay. The spatial distribution and prevalence level of the virus was then mapped for each site. The virus occurred at a high prevalence in the surveyed colonies of Okinawa and Taiwan (100% infection rate across all sites), whereas virus prevalence was variable (30%–100%) or none (0%) at the sites in Penang. Coincidentally, colonies in Okinawa and Taiwan displayed a weak intercolonial boundary, as aggression between colonies is generally low or moderate. Contrastingly, sites in Penang were found to harbor a high proportion of mutually aggressive colonies, a pattern potentially indicative of complex colony composition. Our statistical analyses further confirmed the observed correlation, implying that intercolonial interactions likely contribute as one of the effective facilitators of/barriers to virus prevalence in the field population of this ant species.
Risk of Acute Myocardial Infarction Among New Users of Allopurinol According to Serum Urate Level: A Nested Case-Control Study
Authors: Rodríguez-Martín Sara , de Abajo Francisco J. , Gil Miguel , González-Bermejo Diana , Rodríguez-Miguel Antonio , Barreira-Hernández Diana , Mazzucchelli Ramón , García-Lledó Alberto , García-Rodríguez Luis A.
Published: December 2019

Objectives: To test the hypothesis that allopurinol reduces the risk of acute myocardial infarction (AMI) in hyperuricemic patients and to assess whether the effect is dependent on dose, duration and serum uric acid (SUA) level attained after treatment. Methods: Nested case-control study over the period 2002–2015. From a cohort of patients aged 40–99 years old, we identified incident AMI cases and randomly selected five controls per case, matched for exact age, sex and index date. Adjusted odds ratios (AOR) and 95% CI were computed through unconditional logistic regression. Only new users of allopurinol were considered. Results: A total of 4697 AMI cases and 18,919 controls were included. Allopurinol use was associated with a reduced risk of AMI mainly driven by duration of treatment (AOR ≥180 days = 0.71; 95% CI: 0.60–0.84). Among long-term users (≥180 days), the reduced risk was only observed when the SUA level attained was below 7 mg/dL (AOR<6 mg/dL = 0.64; 95% CI: 0.49–0.82; AOR6–7mg/dL = 0.64; 95%CI:0.48-0.84); AOR>7mg/dL = 1.04; 95% CI: 0.75–1.46; p for trend = 0.001). A dose-effect was observed but faded out once adjusted for the SUA level attained. The reduced risk of AMI occurred in both patients with gout and patients with asymptomatic hyperuricemia. Conclusions: The results confirm a cardioprotective effect of allopurinol which is strongly dependent on duration and SUA level attained after treatment.
Impact of A Six Week Training Program on Ventilatory Efficiency, Red Blood Cell Rheological Parameters and Red Blood Cell Nitric Oxide Signaling in Young Sickle Cell Anemia Patients: A Pilot Study
Authors: Grau Marijke , Nader Elie , Jerke Max , Schenk Alexander , Renoux Celine , Dietz Thomas , Collins Bianca , Bizjak Daniel Alexander , Joly Philippe , Bloch Wilhelm , Prokop Aram , Connes Philippe
Published: December 2019

Patients with sickle cell anemia (SCA) show impaired ventilatory efficiency, altered blood rheology, high levels of oxidative/nitrosative stress and enhanced hemolysis with large amounts of circulating free hemoglobin, which reduces nitric oxide (NO) bioavailability. The aim of the study was to investigate whether physical exercise could improve these physiological and biological markers described to contribute to SCA pathophysiology. Twelve SCA patients participated in a controlled six weeks training program with moderate volume (two sessions per week with 15–30 min duration per session) and intensity (70% of the first ventilatory threshold). Parameters were compared before (T0) and after (T1) training. Daily activities were examined by a questionnaire at T0 and one year after the end of T1. Results revealed improved ventilatory efficiency, reduced nitrosative stress, reduced plasma free hemoglobin concentration, increased plasma nitrite levels and altered rheology at T1 while no effect was observed for exercise performance parameters or hematological profile. Red blood cell (RBC) NO parameters indicate increased NO bioavailability which did not affect RBC deformability. Participants increased their daily life activity level. The data from this pilot study concludes that even low intensity activities are feasible and could be beneficial for the health of SCA patients.
Can Law Address Intersectional Sexual Harassment? The Case of Claimants with Personality Disorders
Authors: O’Connell Karen
Published: December 2019

Sexual harassment across multiple grounds, including race, disability, sexuality and age, remains an entrenched problem that is poorly dealt with in law. Prevalence rates for intersectional sexual harassment are higher for certain groups, while legal redress is low. This paper examines case law on sexual harassment in Australia where there are intersectional factors and asks whether the “intersectionality” section inserted into the federal Sex Discrimination Act in 2011 has impacted legal practice and decision-making. In particular, it considers the situation of sexual harassment claimants with behavioural and personality traits that are considered “disordered” and the specifically gendered disability stereotypes that shape their treatment in law. Recent cases in Australia dealing with the sexual harassment of people with personality disorders show that intersectionality provisions of sexual harassment laws may in fact be used to undermine a legal claim by a person with disability rather than strengthen it. This article argues that an intersectional legal feminist perspective on harassment is needed for the law to work.
Functional Mobility and Basic Motor Skills in Patients with Multiple Sclerosis and Its Relation to the Anthropometrical Status and Body Composition Parameters
Authors: Matusik Edyta , Augustak Aldona , Durmala Jacek
Published: December 2019

Background and objectives: Patients with multiple sclerosis (MS) have many potential risk factors (spasticity, immobilization, glucocorticoids use) which can deteriorate the anthropometrical status and body composition and may have a potential negative impact on functional mobility and basic motor skill improvement after physiotherapy. The aim of the study was to assess the functional mobility and basic motor skills in patients with MS and to correlate them with disability and anthropometrical status and body composition parameters. Materials and Methods: Timed Up-and-Go Test (TUG) and six-min walk test (6MWT) were performed in 36 patients with MS before and after 4 weeks of physiotherapy. Body mass index (BMI), waist-to-height ratio (W/HtR), and waist-to-hip ratio (WHR) were assessed in this group. Body composition was evaluated by bioelectrical impedance analysis (BIA) and fat mass (FAT), fat free mass (FFM), total body water (TBW), and predicted muscle mass (PMM) were expressed as percentage of body mass. Clinical status was assessed by Expanded Disability Status Scale (EDSS) and Ambulatory Index (AI) scales. Results: After physiotherapy, there was a significant improvement in functional mobility and basic motor skills assessed by total distance in 6MWT (p < 0.001) and in TUG trials (p < 0.001). Positive significant correlations were found between the results obtained in both tests (either before and after physiotherapy) vs. FFM, TBW, and PMM, whilst worse results in functional mobility and basic motor skills correlated significantly with higher WHtR, WHR, and FAT (p < 0.05). Clinical status (EDSS) was significantly related to the WHtR and body composition parameters with the same manner as the results in the either 6MWT and TUG. However, there were no significant relationships between BMI vs. either clinical status (EDSS, AI) or functional mobility tests results in patients with MS. Conclusions: Functional mobility and basic motor skills may be significantly improved during physiotherapy, but they are related to the anthropometrical status and body composition of MS patients. Moreover, disability status is also significantly related to these parameters. Body composition deterioration seems to be the important target for the therapeutic intervention in MS patients. For proper nutritional status assessment in patients with MS, body composition analysis or WHtR instead BMI should to be used.
Dynamic Properties of Water Confined in Graphene-Based Membrane: A Classical Molecular Dynamics Simulation Study
Authors: Lee One-Sun
Published: December 2019

We performed molecular dynamics simulations of water molecules inside a hydrophobic membrane composed of stacked graphene sheets. By decreasing the density of water molecules inside the membrane, we observed that water molecules form a droplet through a hydrogen bond with each other in the hydrophobic environment that stacked graphene sheets create. We found that the water droplet translates as a whole body rather than a dissipate. The translational diffusion coefficient along the graphene surface increases as the number of water molecules in the droplet decreases, because the bigger water droplet has a stronger van der Waals interaction with the graphene surface that hampers the translational motion. We also observed a longer hydrogen bond lifetime as the density of water decreased, because the hydrophobic environment limits the libration motion of the water molecules. We also calculated the reorientational correlation time of the water molecules, and we found that the rotational motion of confined water inside the membrane is anisotropic and the reorientational correlation time of confined water is slower than that of bulk water. In addition, we employed steered molecular dynamics simulations for guiding the target molecule, and measured the free energy profile of water and ion penetration through the interstice between graphene sheets. The free energy profile of penetration revealed that the optimum interlayer distance for desalination is ~10 Å, where the minimum distance for water penetration is 7 Å. With a 7 Å interlayer distance between the graphene sheets, water molecules are stabilized inside the interlayer space because of the van der Waals interaction with the graphene sheets where sodium and chloride ions suffer from a 3–8 kcal/mol energy barrier for penetration. We believe that our simulation results would be a significant contribution for designing a new graphene-based membrane for desalination.
Microalgae in Food-Energy-Water Nexus: A Review on Progress of Forward Osmosis Applications
Authors: Wibisono Yusuf , Agung Nugroho Wahyunanto , Akbar Devianto Luhur , Adi Sulianto Akhmad , Roil Bilad Muhammad
Published: December 2019

Nowadays the world is facing vulnerability problems related to food, energy and water demands. The challenges in those subsystems are intertwined and thus require inter-discipline approaches to address them. Bioresources offer promising solutions of the dilemma. Microalgae biomass is expected to become a superfood and a favorable energy feedstock and assist in supplying clean water and treat wastewater. Efficient mass production of microalgae, both during upstream and downstream processes, is thus a key process for providing high quality and affordable microalgae biomass. This paper covers recent progress in microalgae harvesting and dewatering by using osmotic driven membrane process, i.e., forward osmosis. Critical factors during forward osmosis process for microalgae harvesting and dewatering are discussed. Finally, perspective on further research directions and implementation scenarios of the forward osmosis are also provided.
Effect of Salt Bath Nitrocarburizing and Post-Oxidation on Static and Fatigue Behaviours of a Construction Steel
Authors: Campagnolo Alberto , Dabalà Manuele , Meneghetti Giovanni
Published: December 2019

Several surface modification technologies are typically applied to improve the mechanical properties of the material surface of structural components subjected to severe conditions of load, wear and chemical erosion of the surface. The nitrocarburizing and post-oxidation heat treatment, also known as quench-polish-quench (QPQ), improves the fatigue, wear and corrosion resistance properties of the material, since it increases the surface hardness and generates surface compressive residual stresses. In the present contribution, the effects of the salt bath nitrocarburizing and post-oxidation heat treatment on the static and fatigue behaviours of 39NiCrMo3 construction steel have been investigated by experimentally testing plain as well as notched specimens. For comparison purposes, 39NiCrMo3 construction steel, both untreated and treated, and X5CrNiCuNb 16-4 stainless steel have been tested. First, the microstructure of the untreated and treated steel has been identified by metallographic analysis; micro-hardness measurements have been collected and residual stresses profiles have been obtained by using the X-ray diffraction technique. Then, experimental static and fatigue tests have been performed. Finally, the fracture surfaces have been analysed to locate fatigue crack nucleation sites.
Effects of Mo Concentration on the Structural and Corrosion Properties of Cu–Alloy
Authors: Hernández Oscar , Aguilar Claudio , Medina Ariosto
Published: December 2019

Mechanical Alloying (MA) has the ability to extend the solubility limits of immiscible alloys in a solid state. In this work, a Cu-10 wt% Mo alloy was synthesized by mechanical alloying, using a high-energy mill type SPEX. The X-ray diffraction and Rietveld results show a crystallite size of 24 and 22 nm of Cu and Mo, respectively, with an occupation value of Mo inside the Cu structure of 27%, which was identificated by Energy Dispersive X-ray Spectroscopy and High-Resolution Transmission Electron Microscopy analysis. After that, the alloy was sinterized in an oven, heating the alloy to 1000 °C—close to the melting point of Cu (1085 °C). Electrochemical tests were carried out under a saline environment of synthetic seawater. The results show that the polarization curve of the alloy showed a pitting corrosion at about 134.83 mV, as well as a repasivation phenomenon (Erp = 241.47 mV) in the cathodic branch. Finally, three time constants were observed in the Nyquist diagrams: formation of a corrosion product film, load transfer, and diffusion, indicating that the corrosion properties in this alloy were improved compared with other Cu–alloys.
Microstructural Evolution and Short-Term Creep Rupture of the Simulated HAZ in T92 Steel Normalized at Different Temperatures
Authors: Wu Tai-Jung , Liao Chien-Chun , Chen Tai-Cheng , Shiue Ren-Kae , Tsay Leu-Wen
Published: December 2019

T92 steel tubes have been widely applied in advanced supercritical boilers to replace Gr.91 tubes. Simulated samples with microstructures similar to those present in the heat-affected zone (HAZ) of a T92 steel weld were subjected to short-term creep tests in the study. T92 steel tubes were normalized at either 1213 K (L) or 1333 K (H) for 1 h, followed by tempering (T) at 1033 K for 2 h. After the normalizing and tempering treatments, the HT samples comprised finer precipitates but in greater numbers along the prior austenite grain boundaries (PAGBs) and martensite lath boundaries, as compared with those of the LT samples. The HAZ microstructures in the T92 steel welds were simulated by using an infrared heating system, which included over-tempering (OT, below AC1) and partial transformation (PT, slightly below AC3) zones. Martensite laths in the OT sample were more likely to be replaced by numerous cellular structures or subgrains together with spherodized carbides mainly located at the lath and austenite grain boundaries. Furthermore, coarser but fewer carbides were found along the refined lath and grain boundaries in the PT samples, in comparison with other samples in each group. Short-term creep tests showed that the PT samples were more likely to fracture than other samples in each group. Moreover, under the same testing conditions, the microstructures of T92 steel were more stable and resistant to degradation than those of T91 steel after welding or loading at elevated temperatures. Such events were responsible for higher creep resistance of the simulated T92 samples than that of the simulated T91 samples under the same creep-rupture conditions.
Numerical Modeling and Experimental Verification for High-Speed Forming of Al5052 with Single Current Pulse
Authors: Park Hyeong-Gyu , Kang Beom-Soo , Kim Jeong
Published: December 2019

Application of electric current pulses during plastic deformation changes the mechanical behavior owing to the electro-plastic effect. The effect of electric current pulses on the Al5052 alloy is investigated in this study. In order to demonstrate the advantages of passing electric current pulses through a metal sheet during the forming process, a uniaxial tensile test with an electric current pulse was carried out using a self-designed device; this device can apply a 2-kA electric current pulse to the specimen for a short period (>100ms). The electric current increases the temperature of the specimen due to Joule heating. It is, therefore, necessary to decouple the thermal effect from the overall behavior to understand only the contribution of electric current in the mechanical behavior. Firstly, an electro-thermo-mechanical finite element study of an electrically assisted uniaxial tensile test of Al5052 alloy is performed to isolate the thermal effect. The simulated results yielded the thermal effect due to the electric current. By comparing the experimental and simulated results, the contribution of electric current is decoupled from that of thermal effect. The electric current-dependent material model is implemented into the commercial FEM code LS-DYNA using user-defined material(UMAT) subroutine. The electric current-dependent material model was used to simulate the electro-mechanical finite element analysis of the high-speed forming of an aluminum sheet with electric current pulse. Simulation results were compared with experimental results at several applied electric currents to evaluate the accuracy of the UMAT. The present work can be utilized to develop simpler constitutive models for the mechanical behavior of metals subjected to a pulsed electric current.
Reusable Standardized Universal Interface Module (RSUIM) for Generic Organ-on-a-Chip Applications
Authors: Sun Qiyue , Pei Jianghua , Li Qinyu , Niu Kai , Wang Xiaolin
Published: December 2019

The modular-based multi-organ-on-a-chip enables more stable and flexible configuration to better mimic the complex biological phenomena for versatile biomedical applications. However, the existing magnetic-based interconnection modes are mainly realized by directly embedding and/or fixing magnets into the modular microfluidic devices for single use only, which will inevitably increase the complexity and cost during the manufacturing process. Here, we present a novel design of a reusable standardized universal interface module (RSUIM), which is highly suitable for generic organ-on-chip applications and their integration into multi-organ systems. Both pasting-based and clamping-based interconnection modes are developed in a plug-and-play manner without fluidic leakage. Furthermore, due to the flexibility of the modular design, it is simple to integrate multiple assembled modular devices through parallel configuration into a high throughput platform. To test its effectiveness, experiments on the construction of both the microvascular network and vascularized tumor model are performed by using the integration of the generic vascularized organ-on-a-chip module and pasting-based RSUIM, and their quantitative analysis results on the reproducibility and anti-cancer drug screening validation are further performed. We believe that this RSUIM design will become a standard and critical accessory for a broad range of organ-on-a-chip applications and is easy for commercialization with low cost.
Effect of Enhanced Squeezing Needle Structure on the Jetting Performance of a Piezostack-Driven Dispenser
Authors: Huang Xiang , Lin Xiaolong , Jin Hang , Lin Siying , Bu Zhenxiang , He Gonghan , Sun Daoheng , Wang Lingyun
Published: December 2019

Advanced dispensing technology is urgently needed to improve the jetting performance of fluid to meet the requirements of electronic product integration and miniaturization. In this work, an on–off valve piezostack-driven dispenser was used as a study object to investigate the effect of needle structure on jetting performance. Based on fluid dynamics, we investigated nozzle cavity pressure and jet velocity during the dispensing process using theoretical simulation for needles with and without a side cap. The results showed that the needle with a side cap had larger jet velocity and was capable of generating 8.27 MPa of pressure in the nozzle cavity, which was 2.39 times larger than the needle without a side cap. Further research on the influence of the nozzle and needle structural parameters showed that a nozzle conic angle of 85°–105°, needle conic angle of 10°–35°, and side clearance of 0.1–0.3 mm produced a dispenser with a large jet velocity and stable performance, capable of dispensing microscale droplets. Finally, a smaller droplet diameter of 0.42 mm was achieved in experiments using a glycerol/ethanol mixture, with a variation range of ± 4.61%.
Development of a Lab-on-a-Disk Platform with Digital Imaging for Identification and Counting of Parasite Eggs in Human and Animal Stool
Authors: Sukas Sertan , Van Dorst Bieke , Kryj Agata , Lagatie Ole , De Malsche Wim , Stuyver Lieven J.
Published: December 2019

We present a lab-on-a-disk technology for fast identification and quantification of parasite eggs in stool. We introduce a separation and packing method of eggs contained in 1 g of stool, allowing for removal of commonly present solid particles, fat droplets and air bubbles. The separation is based on a combined gravitational and centrifugal flotation, with the eggs guided to a packed monolayer, enabling quantitation and identification of subtypes of the eggs present in a single field of view (FOV). The prototype was tested with stool samples from pigs and humans infected with intestinal parasites (soil-transmitted helminths eggs). The quality of the images created by this platform was appropriate for identification and quantification of egg types present in the sample.
Versatile Microfluidic Mixing Platform for High- and Low-Viscosity Liquids via Acoustic and Chemical Microbubbles
Authors: Guan Yanfang , Sun Baichuan
Published: December 2019

Microfluidic mixers have been extensively studied due to their wide application in various fields, including clinical diagnosis and chemical research. In this paper, we demonstrate a mixing platform that can be used for low- and high-viscosity liquid mixing by integrating passive (utilizing the special circulating crossflow characteristics of a zigzag microstructure and cavitation surfaces at the zigzag corners) and active (adding an acoustic field to produce oscillating microbubbles) mixing methods. By exploring the relationship between the active and passive mixing methods, it was found that the microbubbles were more likely generated at the corners of the zigzag microchannel and achieved the best mixing efficiency with the acoustically generated microbubbles (compared with the straight channel). In addition, a higher mixing effect was achieved when the microchannel corner angle and frequency were 60° and 75 kHz, respectively. Meanwhile, the device also achieved an excellent mixing effect for high-viscosity fluids, such as glycerol (its viscosity was approximately 1000 times that of deionized (DI) water at 25 °C). The mixing time was less than 1 s, and the mixing efficiency was 0.95 in the experiment. Furthermore, a new microbubble generation method was demonstrated based on chemical reactions. A higher mixing efficiency (0.97) was achieved by combining the chemical and acoustic microbubble methods, which provides a new direction for future applications and is suitable for the needs of lab-on-a-chip (LOC) systems and point-of-care testing (POCT).
Mineralogy and Distribution of Critical Elements in the Sn–W–Pb–Ag–Zn Huanuni Deposit, Bolivia
Authors: Cacho Andreu , Melgarejo Joan-Carles , Camprubí Antoni , Torró Lisard , Castillo-Oliver Montgarri , Torres Belén , Artiaga David , Tauler Esperança , Martínez Álvaro , Campeny Marc , Alfonso Pura , Arce-Burgoa Osvaldo R.
Published: December 2019

The polymetallic Huanuni deposit, a world-class tin deposit, is part of the Bolivian tin belt. As a likely case for a “mesothermal” or transitional deposit between epithermal and porphyry Sn types (or shallow porphyry Sn), it represents a case that contributes significantly to the systematic study of the distribution of critical elements within the “family” of Bolivian tin deposits. In addition to Sn, Zn and Ag, further economic interest in the area resides in its potential in critical elements such as In, Ga and Ge. This paper provides the first systematic characterisation of the complex mineralogy and mineral chemistry of the Huanuni deposit with the twofold aim of identifying the mineral carriers of critical elements and endeavouring plausible metallogenic processes for the formation of this deposit, by means of a multi-methodological approach. With In concentrations consistently over 2000 ppm, the highest potential for relevant concentrations in this metal resides in widespread tin minerals (cassiterite and stannite) and sphalerite. Hypogene alteration assemblages are hardly developed due to the metasedimentary nature of host rocks, but the occurrence of potassium feldspar, schorl, pyrophyllite and dickite as vein material stand for potassic to phyllic or advanced argillic alteration assemblages and relatively high-temperature (and low pH) mineralising fluids. District-scale mineralogical zonation suggests a thermal zonation with decreasing temperatures from the central to the peripheral areas. A district-scale zonation has been also determined for δ34SVCDT values, which range −7.2‰ to 0.2‰ (mostly −7‰ to −5‰) in the central area and −4.2‰ to 1.0‰ (mainly constrained between −2‰ and 1‰) in peripheral areas. Such values stand for magmatic and metasedimentary sources for sulfur, and their spatial zoning may be related to differential reactivity between mineralising fluids and host rocks, outwardly decreasing from the central to the peripheral areas.
Dating Oceanic Subduction in the Jurassic Bangong–Nujiang Oceanic Arc: A Zircon U–Pb Age and Lu–Hf Isotopes and Al-in-Hornblende Barometry Study of the Lameila Pluton in Western Tibet, China
Authors: Liu De-Liang , Shi Min , Jiang Shao-Yong
Published: December 2019

The subduction and close of the Mesozoic Bangong–Nujiang Ocean (BNO) led to a collision of the Lhasa and Qiangtang blocks, which formed the backbone of the Tibetan Plateau (the largest and highest plateau on Earth). However, the detailed subduction processes (in particular, the oceanic subduction processes) within the BNO are still not clear. Here, we focus on the plutonic complex of the oceanic arc in the Bangong–Nujiang suture (BNS) and report field observations on zircon U–Pb ages, Lu–Hf isotopes, and the Al-in-hornblende barometry of quartz diorites from the Lameila pluton in western Tibet. Zircon from the quartz diorites yielded a LA-ICP-MS U–Pb age of 164 Ma. The zircon showed very positive εHf(t) values from 10.5 to 13.9, suggesting the Lameila pluton was likely sourced from the depleted-mantle wedge, which is in contrast with contemporary (164–161 Ma) volcanic rocks in the region that had negative εHf(t) values of −7.4 to −16.2 and a magma source from partial melting of subducted sediments. The Lameila pluton showed a temperature-corrected Al-in-hornblende pressure of 3.9 ± 0.8 kbar, corresponding to an emplacement depth of 13 ± 3 km. Therefore, the thickness of the Jurassic oceanic arc crust must have doubled since the initial growth of the oceanic arc on the BNO crust, with a crustal thickness of 6.5 km during the Middle Jurassic. In combination with previous works on volcanic rocks, this study further supports a two-subduction zone model in association with the BNO during the Middle Jurassic, namely, a north-dipping BNO–Qiangtang subduction zone and an oceanic subduction zone within the BNO. The latter oceanic subduction zone produced the depleted-mantle-derived Lameila pluton and the subducted sediment-derived volcanic rocks in the fore arc.
Editorial for Special Issue: “Recent Trends in Phosphate Mining, Beneficiation and Related Waste Management”
Authors: Taha Yassine , Benzaazoua Mostafa
Published: December 2019

This Special Issue contains a series of selected papers concerning phosphate along with its mining and transformation life cycle [...]