bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of CVD Silica Membranes Having High Hydrogen Permeance and Steam Durability and a Membrane Reactor for a Water Gas Shift Reaction
Authors: Nishida Ryoichi , Tago Toshiki , Saitoh Takashi , Seshimo Masahiro , Nakao Shin-ichi
Published: October 2019

Water gas shift reaction of carbon monoxide (CO) with membrane reactors should be a promising method for hydrogen mass-production because of its high CO conversion, high hydrogen purity and low carbon dioxide emission. For developing such membrane reactors, we need hydrogen permselective membranes with high hydrogen permeance with order of 10−6 mol m−2 s−1 Pa−1 at 573 K and high steam durability. In this study, we have optimized the kind of substrates, precursors, vapor concentration, and chemical vapor deposition (CVD) time using the counter-diffusion CVD method for developing such membranes. The developed membrane prepared from hexamethyldisiloxane has a hydrogen permeance of 1.29 × 10−6 mol m−2 s−1 Pa−1 at 573 K and high steam durability. We also conducted water gas shift reactions with membrane reactors installed the developed silica membranes. The results indicated that reactions proceed efficiently with the conversion around 95–97%, hydrogen purity around 94%, and hydrogen recovery around 60% at space velocity (SV) 7000.
Perfluorosulfonic Acid Membranes Thermally Treated and Modified by Dopants with Proton-Acceptor Properties for Asparaginate and Potassium Ions Determination in Pharmaceuticals
Authors: Parshina Anna , Kolganova Tatyana , Safronova Ekaterina , Osipov Alexander , Lapshina Ekaterina , Yelnikova Anastasia , Bobreshova Olga , Yaroslavtsev Andrey
Published: October 2019

The influence of incorporation of the dopants with proton-acceptor properties into perfluorosulfonic acid cation exchange membranes (MF-4SC and Nafion), and their treatment conditions on the characteristics of Donnan potential (DP)-sensors (analytical signal is the Donnan potential) in the aqueous solutions containing asparaginate and potassium ions in a wide pH range was investigated. A silica, surface modified by 3-aminopropyl and 3-(2-imidazolin-1-yl)-propyl groups, was used as the dopant. The membranes were subjected to mechanical deformation and thermal treatment at various relative humidities. The relationship between water uptake and diffusion permeability of membranes subjected to modification and treatment and the cross sensitivity of DP-sensors based on them to counter and co-ions was studied. The multisensory systems for the simultaneous determination of asparaginate and potassium ions in a concentration range from 1.0 × 10−4 to 1.0 × 10−2 M and pH range from 4 to 8 were developed. An array of cross-sensitive DP-sensors based on MF-4SC membranes containing 3 wt.% SiO2 modified by 10 mol.% 3-aminopropyl and 3-(2-imidazolin-1-yl)-propyl was used for the potassium asparaginate hemihydrate and magnesium asparaginate pentahydrate determination in Panangin® (with an error of 2 and 4%, respectively).
Effect of Milling Conditions on the Microstructural Design in Aluminum Based Alloy Fabricated by SPS
Authors: Smirnov Anton , Kuznetsova Ekaterina , Pristinskiy Yuri , Podrabinnik Pavel , Mironov Alexander , Gershman Iosif , Peretyagin Pavel
Published: October 2019

In this work, aluminum-based alloys were mechanically alloyed by various doping elements followed by spark plasma sintering. Three different mixing methods were studied. First, all elemental powders were mixed for 24 h. In the second and the third method, powders were divided into three groups, and each group was milled separately for different times. Then the obtained mixtures were grouped together and again milled for 12 and 24 h, for the M2 and M3 mixtures, respectively. The influence of milling parameters on the microstructural features of sintered samples was determined using a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectroscopy system. The correlation observed between the milling time and microstructural evolution of the powder particles during the milling process was to determine the optimal process parameters. For the first time, the present research has demonstrated the effectiveness of the milling process for the preparation of tailored mixtures of metallic powders, enabling microstructural characteristics that could be favorable for the formation of secondary structures on the tribosurfaces.
Synthesis of Poly-Alumino-Ferric Sulphate Coagulant from Acid Mine Drainage by Precipitation
Authors: Mwewa Brian , Stopić Srećko , Ndlovu Sehliselo , Simate Geoffrey S. , Xakalashe Buhle , Friedrich Bernd
Published: October 2019

The wastes generated from both operational and abandoned coal and metal mining are an environmental concern. These wastes, including acid mine drainage (AMD), are treated to abate the devastating effects they have on the environment before disposal. However, AMD contains valuable resources that can be recovered to subsidize treatment costs. Two of the major constituents of coal AMD are iron and aluminium, which can be recovered and engineered to function as coagulants. This work examines the potential of producing a poly-alumino-ferric sulphate (AMD-PAFS) coagulant from coal acidic drainage solutions. The co-precipitation of iron and aluminium is conducted at pH values of 5.0, 6.0 and 7.0 using sodium hydroxide in order to evaluate the recovery of iron and aluminium as hydroxide precipitates while minimizing the co-precipitation of the other heavy metals. The precipitation at pH 5.0 yields iron and aluminium recovery of 99.9 and 94.7%, respectively. An increase in the pH from 5.0 to 7.0 increases the recovery of aluminium to 99.1%, while the recovery of iron remains the same. The precipitate formed at pH 5.0 is used to produce a coagulant consisting of 89.5% and 10.0% iron and aluminium, respectively. The production of the coagulant is carried out by dissolving the precipitate in 5.0% (w/w) sulphuric acid. Subsequently, the treatment of the brewery wastewater shows that the AMD-PAFS coagulant is as efficient as the conventional poly ferric sulphate (PFS) coagulant. The turbidity removal is 91.9 and 87.8%, while the chemical oxygen demand (COD) removal is 56.0 and 64.0% for AMD-PAFS and PFS coagulants, respectively. The developed process, which can easily be incorporated into existing AMD treatment plants, not only reduces the sludge disposal problems but also creates revenue from waste.
Microstructure and Mechanical Properties of Gas Tungsten Arc Welded High Manganese Steel Sheet
Authors: Park Geon-Woo , Jo Haeju , Park Minha , Shin Sunmi , Ko Won-Seok , Park Nokeun , Kim Byung-Jun , Ahn Yong-Sik , Jeon Jong
Published: October 2019

This study investigated microstructure and mechanical properties of high manganese steel sheet fabricated by gas tungsten arc welding (GTAW). The weld zone showed longitudinal coarse grains due to the coalescence of columnar dendrites grown into the direction of heat source, and the HAZ showed equiaxed coarser grains than the base metal due to the thermal effect of GTAW process. Mn segregation occurred in the inter-dendritic regions of the weld zone and Mn depletion thus occurred in the weld matrix. Although the stacking fault energy is expected to be lowered due to the Mn depletion, no noticeable change in the initial phase and deformation mechanism was found in the weld matrix. Lower hardness and strength were shown in the weld zone than the base metal, which was caused by the coarser grain size. The negative strain rate sensitivity observed in the weld zone and the base metal is considered to have originated from the negative strain rate dependency of twinning nucleation stress.
Mechanical Properties and Microstructure Characterization of AISI “D2” and “O1” Cold Work Tool Steels
Authors: Algarni Mohammed
Published: October 2019

This research analyzes the mechanical properties and fracture behavior of two cold work tool steels: AISI “D2” and “O1”. Tool steels are an economical and efficient solution for manufacturers due to their superior mechanical properties. Demand for tool steels is increasing yearly due to the growth in transportation production around the world. Nevertheless, AISI “D2” and “O1” (locally made) tool steels behave differently due to the varying content of their alloying elements. There is also a lack of information regarding their mechanical properties and behavior. Therefore, this study aimed to investigate the plasticity and ductile fracture behavior of “D2” and “O1” via several experimental tests. The tool steels’ behavior under monotonic quasi-static tensile and compression tests was analyzed. The results of the experimental work showed different plasticity behavior and ductile fracture among the two tool steels. Before fracture, clear necking appeared on “O1” tool steel, whereas no signs of necking occurred on “D2” tool steel. In addition, the fracture surface of “O1” tool steel showed cup–cone fracture mode, and “D2” tool steel showed a flat surface fracture mode. The dimple-like structures in scanning electron microscope (SEM) images revealed that both tool steels had a ductile fracture mode.
Mechanical Behavior and Microstructure Evolution of a Ti-15Mo/TiB Titanium–Matrix Composite during Hot Deformation
Authors: Zherebtsov Sergey , Ozerov Maxim , Klimova Margarita , Moskovskikh Dmitry , Stepanov Nikita , Salishchev Gennady
Published: October 2019

A Ti-15Mo/TiB titanium–matrix composite (TMC) was produced by spark plasma sintering at 1400 °C under a load of 40 MPa for 15 min using a Ti-14.25(wt.)%Mo-5(wt.)%TiB2 powder mixture. Microstructure evolution and mechanical behavior of the composite were studied during uniaxial compression at room temperature and in a temperature range of 500–1000 °C. At room temperature, the composite showed a combination of high strength (the yield strength was ~1500 MPa) and good ductility (~22%). The microstructure evolution of the Ti-15Mo matrix was associated with the development of dynamic recovery at 500–700 °C and dynamic recrystallization at higher temperatures (≥800 °C). The apparent activation energy of the plastic deformation was calculated and a processing map for the TMC was constructed using the obtained results.
AFM Study of Pyrite Oxidation and Xanthate Adsorption in the Presence of Seawater Salts
Authors: Paredes Álvaro , Acuña Sergio M. , Toledo Pedro G.
Published: October 2019

The effect of seawater ions presents a great challenge to theories about mechanisms of pyrite oxidation, collector adsorption, and surface reactions. As the use of seawater is key to the sustainability of the mining industry in regions without fresh water, there is a need to study the surfaces of minerals and products that are formed in the presence of seawater salts. In this study, atomic force microscopy (AFM) was used to analyze the topography of pyrite surfaces subjected to treatments, including oxidation and exposure to xanthate and solutions of seawater salts and xanthate, at pH 8.5. Topographic details were related to surface products. The results showed that xanthate was adsorbed without hindrance on oxide-free pyrite which validated one well-known model. The results also showed that pyrite oxidized forming a structure of interconnected pillars and that xanthate was adsorbed on the top and skirt of these pillars; the experimental evidence on the increase in the height and width of these pillars validated another well-known model. In the presence of seawater salts, the cations covered the surface of the pyrite, suppressing collector adsorption regardless of the dose. The results are expected to help in decisions about the flotation of sulfide minerals in water with limited metallurgical quality.
Separation of Ag and Cu from Their Aqueous Thiosulfate Complexes by UV-C Irradiation
Authors: Han Chao , Wang Guangxin , Zou Mingjin , Shi Chaoyang
Published: October 2019

In recent years, there has been renewed interest in the use of thiosulfate as a substitute for cyanide in silver leaching. Copper thiosulfate leaching without ammonia was applied to extract silver from silver sulfide, resulting in the production of Ag–Cu polymetallic thiosulfate complexes in solutions. It is necessary to separate Ag–Cu polymetallic thiosulfate complexes with the purposes of silver recovery and copper recycling. In this paper, the feasibility study on the use of UV-C irradiation to separate Ag–Cu polymetallic thiosulfate complexes was investigated based on the different photosensitivity of silver and copper. First, a kinetic study on the photolysis of silver and copper thiosulfate complexes by UV-C was investigated, indicating that the reactions follow first-order kinetics. The rate constant reactions were calculated, and it decreased with solution concentrations. On the other hand, the photoproducts of the silver and copper thiosulfate complexes were characterized by XRD and XPS in order to confirm the phase and chemical composition. It indicated that the silver photoproducts are Ag2S, S, Ag and the copper photoproducts are Cu2S, CuS, CuO, Cu, S. Finally, the four-step continuous separation of Ag–Cu polymetallic thiosulfate complexes by UV-C irradiation was investigated. The silver component was recovered with the accumulated recovery ratio of 97%, and the copper component was recycled with the accumulated recycle ratio of 51%, which made it possible for silver recovery and copper recycling.
Metabolomic Dynamics Reveals Oxidative Stress in Spongy Tissue Disorder During Ripening of Mangifera indica L. Fruit
Authors: Oak Pranjali , Deshpande Ashish , Giri Ashok , Gupta Vidya
Published: October 2019

Spongy tissue disorder, a mesocarp specific malady, severely affects the flavor and pulp characters of Alphonso mango fruit reducing its consumer acceptability. Here, we investigated comparative metabolomic changes that occur during ripening in healthy and spongy tissue-affected fruits using high resolution mass spectrometric analysis. During the spongy tissue formation, 46 metabolites were identified to be differentially accumulated. These putative metabolites belong to various primary and secondary metabolic pathways potentially involved in maintaining the quality of the fruit. Analysis revealed metabolic variations in tricarboxylic acid cycle and gamma amino butyric acid shunt generating reactive oxygen species, which causes stressed conditions inside the mesocarp. Further, reduced levels of antioxidants and enzymes dissipating reactive oxygen species in mesocarp deteriorate the fruit physiology. This oxidative stress all along affects the level of amino acids, sugars and enzymes responsible for flavor generation in the fruit. Our results provide metabolic insights into spongy tissue development in ripening Alphonso mango fruit.
Droplet Microfluidics-Enabled High-Throughput Screening for Protein Engineering
Authors: Weng Lindong , Spoonamore James E.
Published: October 2019

Protein engineering—the process of developing useful or valuable proteins—has successfully created a wide range of proteins tailored to specific agricultural, industrial, and biomedical applications. Protein engineering may rely on rational techniques informed by structural models, phylogenic information, or computational methods or it may rely upon random techniques such as chemical mutation, DNA shuffling, error prone polymerase chain reaction (PCR), etc. The increasing capabilities of rational protein design coupled to the rapid production of large variant libraries have seriously challenged the capacity of traditional screening and selection techniques. Similarly, random approaches based on directed evolution, which relies on the Darwinian principles of mutation and selection to steer proteins toward desired traits, also requires the screening of very large libraries of mutants to be truly effective. For either rational or random approaches, the highest possible screening throughput facilitates efficient protein engineering strategies. In the last decade, high-throughput screening (HTS) for protein engineering has been leveraging the emerging technologies of droplet microfluidics. Droplet microfluidics, featuring controlled formation and manipulation of nano- to femtoliter droplets of one fluid phase in another, has presented a new paradigm for screening, providing increased throughput, reduced reagent volume, and scalability. We review here the recent droplet microfluidics-based HTS systems developed for protein engineering, particularly directed evolution. The current review can also serve as a tutorial guide for protein engineers and molecular biologists who need a droplet microfluidics-based HTS system for their specific applications but may not have prior knowledge about microfluidics. In the end, several challenges and opportunities are identified to motivate the continued innovation of microfluidics with implications for protein engineering.
Reliability of Protective Coatings for Flexible Piezoelectric Transducers in Aqueous Environments
Authors: Mariello Massimo , Guido Francesco , Mastronardi Vincenzo , Giannuzzi Roberto , Algieri Luciana , Qualteri Antonio , Maffezzoli Alfonso , De Vittorio Massimo
Published: October 2019

Electronic devices used for marine applications suffer from several issues that can compromise their performance. In particular, water absorption and permeation can lead to the corrosion of metal parts or short-circuits. The added mass due to the absorbed water affects the inertia and durability of the devices, especially for flexible and very thin micro-systems. Furthermore, the employment of such delicate devices underwater is unavoidably subjected to the adhesion of microorganisms and formation of biofilms that limit their reliability. Thus, the demand of waterproofing solutions has increased in recent years, focusing on more conformal, flexible and insulating coatings. This work introduces an evaluation of different polymeric coatings (parylene-C, poly-dimethyl siloxane (PDMS), poly-methyl methacrylate (PMMA), and poly-(vinylidene fluoride) (PVDF)) aimed at increasing the reliability of piezoelectric flexible microdevices used for sensing water motions or for scavenging wave energy. Absorption and corrosion tests showed that Parylene-C, while susceptible to micro-cracking during prolonged oscillating cycles, exhibits the best anti-corrosive behavior. Parylene-C was then treated with oxygen plasma and UV/ozone for modifying the surface morphology in order to evaluate the biofilm formation with different surface conditions. A preliminary characterization through a laser Doppler vibrometer allowed us to detect a reduction in the biofilm mass surface density after 35 days of exposure to seawater.
Characterization of Single-Nucleus Electrical Properties by Microfluidic Constriction Channel
Authors: Liang Hongyan , Zhang Yi , Chen Deyong , Tan Huiwen , Zheng Yu , Wang Junbo , Chen Jian
Published: October 2019

As key bioelectrical markers, equivalent capacitance (Cne, i.e., capacitance per unit area) and resistance (Rne, i.e., resistivity multiply thickness) of nuclear envelopes have emerged as promising electrical indicators, which cannot be effectively measured by conventional approaches. In this study, single nuclei were isolated from whole cells and trapped at the entrances of microfluidic constriction channels, and then corresponding impedance profiles were sampled and translated into single-nucleus Cne and Rne based on a home-developed equivalent electrical model. Cne and Rne of A549 nuclei were first quantified as 3.43 ± 1.81 μF/cm2 and 2.03 ± 1.40 Ω·cm2 (Nn = 35), which were shown not to be affected by variations of key parameters in nuclear isolation and measurement. The developed approach in this study was also used to measure a second type of nuclei, producing Cne and Rne of 3.75 ± 3.17 μF/cm2 and 1.01 ± 0.70 Ω·cm2 for SW620 (Nn = 17). This study may provide a new perspective in single-cell electrical characterization, enabling cell type classification and cell status evaluation based on bioelectrical markers of nuclei.
Measurement of Heat Dissipation and Thermal-Stability of Power Modules on DBC Substrates with Various Ceramics by SiC Micro-Heater Chip System and Ag Sinter Joining
Authors: Kim Dongjin , Yamamoto Yasuyuki , Nagao Shijo , Wakasugi Naoki , Chen Chuantong , Suganuma Katsuaki
Published: October 2019

This study introduced the SiC micro-heater chip as a novel thermal evaluation device for next-generation power modules and to evaluate the heat resistant performance of direct bonded copper (DBC) substrate with aluminum nitride (AlN-DBC), aluminum oxide (DBC-Al2O3) and silicon nitride (Si3N4-DBC) ceramics middle layer. The SiC micro-heater chips were structurally sound bonded on the two types of DBC substrates by Ag sinter paste and Au wire was used to interconnect the SiC and DBC substrate. The SiC micro-heater chip power modules were fixed on a water-cooling plate by a thermal interface material (TIM), a steady-state thermal resistance measurement and a power cycling test were successfully conducted. As a result, the thermal resistance of the SiC micro-heater chip power modules on the DBC-Al2O3 substrate at power over 200 W was about twice higher than DBC-Si3N4 and also higher than DBC-AlN. In addition, during the power cycle test, DBC-Al2O3 was stopped after 1000 cycles due to Pt heater pattern line was partially broken induced by the excessive rise in thermal resistance, but DBC-Si3N4 and DBC-AlN specimens were subjected to more than 20,000 cycles and not noticeable physical failure was found in both of the SiC chip and DBC substrates by a x-ray observation. The results indicated that AlN-DBC can be as an optimization substrate for the best heat dissipation/durability in wide band-gap (WBG) power devices. Our results provide an important index for industries demanding higher power and temperature power electronics.
The Reduction of Pathogen Load on Ross 708 Broilers when Using Different Sources of Commercial Peracetic Acid Sanitizers in a Pilot Processing Plant
Authors: Feye Kristina M. , Dittoe Dana K. , Shi Zhaohao , Woitte Jessica , Owens Casey M. , Kogut Mike H. , Ricke Steven C.
Published: October 2019

Peracetic acid (PAA) in poultry processing is not necessarily the same from company to company. Anecdotal evidence suggests that PeraClean may be more stable compared to the competition; however, it is not known what impact potential differences in chemical stability may have. In order to evaluate the antimicrobial effects of PAA, one PAA (PeraClean, P) was qualitatively compared against two competitor products (Competitors 1 and 2, C1 and C2) at the University of Arkansas Pilot Processing Plant. A total of 150 Ross 708 broilers (42 d) were used in the current study. Briefly, prior to treatment, 10 birds were sampled post-evisceration (C). Then, one of four treatment groups per PAA were applied (A1, A2, B1, and B2). The birds were dipped in either 400 ppm or 600 ppm PAA (A or B), chilled in either 25 ppm or 45 ppm PAA (1 or 2), and then manually agitated in 400 mL of nBPW for 1 min. There were 10 birds per treatment group in total. The resulting rinsates were transported to the Center for Food Safety and assessed for total microbiological load with total aerobic plate counts (Trypticase Soy Agar; APC), coliforms, (Eosin Methylene Blue Media; EMB), Salmonella (Xylose Lysine Deoxycholate agar, XLD), and Campylobacter (modified Charcoal Cefoperazone Deoxycholate Agar, mCCDA). The microbiological plates were incubated as per manufacturer’s directions. Statistical analyses were calculated in JMP 14.0, with a significance level of p ≤ 0.05. Data indicate that all three sources of PAA are effective sanitizers for poultry processing applications compared within treatment. Qualitatively, there were differences in efficacy between the treatments. However, additional studies will be required to determine if those differences are quantitatively distinctive and if they are attributable to differences in product stability.
Comparative Study on A Novel Pathogen of European Seabass. Diversity of Aeromonas veronii in the Aegean Sea
Authors: Smyrli Maria , Triga Adriana , Dourala Nancy , Varvarigos Panos , Pavlidis Michael , Quoc Viet Ha , Katharios Pantelis
Published: October 2019

Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.
Microbiological Insights into the Stress-Alleviating Property of an Endophytic Bacillus altitudinis WR10 in Wheat under Low-Phosphorus and High-Salinity Stresses
Authors: Yue Zonghao , Shen Yihao , Chen Yanjuan , Liang Anwen , Chu Cuiwei , Chen Can , Sun Zhongke
Published: October 2019

An indole–3–acetic acid producing Bacillus altitudinis WR10 was previously isolated from the root of wheat (Triticum aestivum L.). In this study, the strain WR10 was used for relieving abiotic stresses in wheat under low phosphorus and high saline in hydroponic co-culture models. Significantly, strain WR10 improved wheat seed relative germination rate under salinity stress (200/400 mM NaCl) and the root dry weight in wheat seedlings under phosphorus stress (10 μM KH2PO3) when insoluble phosphates are available. To provide insights into its abiotic stress-alleviating properties, the strain was characterized further. WR10 grows well under different culture conditions. Particularly, WR10 resists salt (12% NaCl) and hydrolyzes both inorganic and organic insoluble phosphates. WR10 uses many plant-derived substrates as sole carbon and energy sources. It produces catalase, amylase, phosphatase, phytase, reductase, and 1–aminocyclopropane–1–carboxylate (ACC) deaminase. In addition, WR10 possesses long peritrichous flagella, and its biofilm formation, as well as phytase production, is induced by abiotic stresses. Overall, the salinity-alleviating property of WR10 in wheat can be attributed to its inherent tolerance to NaCl, formation of biofilm, and production of enzymes, like catalase, amylase, and ACC deaminase. Meanwhile, B. altitudinis WR10 reduces low-phosphorus stress in wheat by production of phosphatases and phytases in the presence of insoluble phosphates.
Label-Free Quantitative Acetylome Analysis Reveals Toxoplasma gondii Genotype-Specific Acetylomic Signatures
Authors: Wang Ze-Xiang , Hu Rui-Si , Zhou Chun-Xue , He Jun-Jun , M. Elsheikha Hany , Zhu Xing-Quan
Published: October 2019

Distinct genotypic and pathogenic differences exist between Toxoplasma gondii genotypes. For example, genotype I is highly virulent, whereas genotype II and genotype III are less virulent. Moreover, Chinese 1 genotype (ToxoDB#9) is also virulent. Here, we compare the acetylomes of genotype 1 (RH strain) and Chinese 1 genotype (ToxoDB#9, PYS strain) of T. gondii. Using mass spectrometry enriched for acetylated peptides, we found a relationship between the levels of protein acetylation and parasite genotype-specific virulence. Notably, lysine acetylation was the largest (458 acetylated proteins) in RH strain, followed by PYS strain (188 acetylated proteins), whereas only 115 acetylated proteins were detected in PRU strain. Our analysis revealed four, three, and four motifs in RH strain, PRU strain and PYS strain, respectively. Three conserved sequences around acetylation sites, namely, xxxxxKAcHxxxx, xxxxxKAcFxxxx, and xxxxGKAcSxxxx, were detected in the acetylome of the three strains. However, xxxxxKAcNxxxx (asparagine) was found in RH and PYS strains but was absent in PRU strain. Our analysis also identified 15, 3, and 26 differentially expressed acetylated proteins in RH strain vs. PRU strain, PRU strain vs. PYS strain and PYS strain vs. RH strain, respectively. KEGG pathway analysis showed that a large proportion of the acetylated proteins are involved in metabolic processes. Pathways for the biosynthesis of secondary metabolites, biosynthesis of antibiotics and microbial metabolism in diverse environments were featured in the top five enriched pathways in all three strains. However, acetylated proteins from the virulent strains (RH and PYS) were more enriched in the pyruvate metabolism pathway compared to acetylated proteins from PRU strain. Increased levels of histone-acetyl-transferase and glycyl-tRNA synthase were detected in RH strain compared to PRU strain and PYS strain. Both enzymes play roles in stress tolerance and proliferation, key features in the parasite virulence. These findings reveal novel insight into the acetylomic profiles of major T. gondii genotypes and provide a new important resource for further investigations of the roles of the acetylated parasite proteins in the modulation of the host cell response to the infection of T. gondii.
The Effect of Maternal Postpartum Practices on Infant Gut Microbiota: A Chinese Cohort Study
Authors: Wang Ying , Liu Yanqun , Bai Jinbing , Chen Xiaoli
Published: October 2019

(1) Background: The human gut microbiota at early life is shaped by numerous factors, especially factors from mothers, which have huge influence on infants’ gut microbiotas. The aim of this study was to investigate the effect of maternal adherence to Chinese traditional postpartum practices of “doing the month” on the development of infant gut microbiota at 6-month postpartum. (2) Methods: A cohort of 62 Chinese women at late pregnancy was recruited from a tertiary general hospital in a central region of China. The participants and their babies were followed up to 6 months postpartum. Finally, 50 mother-infant dyads were enrolled in the study. Women’s adherence to the traditional postpartum practices was measured by adherence to doing the month practices (ADP). Infant fecal samples were collected at six months of age and were analyzed using 16S rRNA V3 and V4 gene region sequences. (3) Results: Ruminococcus gnavus was significantly less abundant in infants whose mothers had a better adherence to the traditional postpartum practices of “doing the month.” Infants receiving Clostridium-butyricum during the first month after delivery had a significant dominance of Escherichia/Shigella. (4) Conclusions: Adherence to the traditional postpartum practices of “doing the month” can impact an infant’s gut microbiota at 6 months of age. Infants receiving probiotics during the first month after delivery had a significant dominance of opportunistic pathogens.
Inflammatory Immune Responses in Patients with Tick-Borne Encephalitis: Dynamics and Association with the Outcome of the Disease
Authors: Bogovič Petra , Lusa Lara , Korva Miša , Lotrič-Furlan Stanka , Resman-Rus Katarina , Pavletič Miša , Avšič-Županc Tatjana , Strle Klemen , Strle Franc
Published: October 2019

Information on the association of inflammatory immune responses and disease outcome after tick-borne encephalitis (TBE) is limited. In the present study, we assessed the levels of 24 cytokines/chemokines associated with innate and adaptive immune responses in matched serum and cerebrospinal fluid (CSF) samples of 81 patients at first visit, and in serum at follow-up time points. Serum levels of several cytokines/chemokines obtained during the meningoencephalitic phase of TBE differed compared to the levels at a follow-up visit 2 months later; several significant differences were also found in cytokine/chemokine levels in serum at 2 months compared to the last time point, 2–7 years after acute illness. Cytokines/chemokines levels in CSF or serum obtained at the time of acute illness or serum levels obtained 2 months after the onset of TBE did not have predictive value for an unfavorable outcome 2–7 years later. In contrast, serum levels of mediators associated with Th17 responses were lower in patients with unfavorable outcome whereas those associated with other adaptive or innate immune responses were higher at the last visit in those with an unfavorable outcome. These findings provide new insights into the immunopathogenesis of TBE and implicate inflammatory immune responses with post-encephalitic syndrome years after the initial infection.
Functional Characterization and Structural Analysis of NADH Oxidase Mutants from Thermus thermophilus HB27: Role of Residues 166, 174, and 194 in the Catalytic Properties and Thermostability
Authors: Rocha-Martin Javier , Sánchez-Murcia Pedro , López-Gallego Fernando , Hidalgo Aurelio , Berenguer José , Guisan José
Published: October 2019

The Thermus thermophilus strain HB27 NADH-oxidase (Tt27-NOX) catalyzes the oxidation of nicotinamide adenine dinucleotide (NAD(P)H) by reducing molecular oxygen to hydrogen peroxide in a two-electron transfer mechanism. Surprisingly, Tt27-NOX showed significant differences in catalytic properties compared to its counterpart from the strain HB8 (Tt8-NOX), despite a high degree of sequence homology between both variants. The sequence comparison between both enzymes revealed only three divergent amino acid residues at positions 166, 174, and 194. Motivated with these findings, in this work we performed mutagenesis experiments in the former three positions to study the specific role of these residues in the catalytic properties and thermostability of Tt27-NOX. We subjected five mutants, along with the wild-type enzyme, to biochemical characterization and thermal stability studies. As a result, we identified two more active and more thermostable variants than any Tt8-NOX variant reported in the literature. The most active and thermostable variant K166/H174/Y194 retained 90% of its initial activity after 5 h at pH 7 and 80 °C and an increase in melting temperature of 48.3 °C compared with the least active variant K166/R174/Y194 (inactivated after 15 min of incubation). These results, supported by structural analysis and molecular dynamics simulation studies, suggest that Lys at position 166 may stabilize the loop in which His174 is located, increasing thermal stability.
Improving the Quality of Ferruginous Chromite Concentrates Via Physical Separation Methods
Authors: Tripathy Sunil , Murthy Y , Singh Veerendra , Farrokhpay Saeed , Filippov Lev
Published: October 2019

The low chromium-to-iron ratio of chromite ores is an important issue in some chromite deposits. The value of the chromite ore is indeed dictated in the market by its iron, as well as its chromium content. In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium-to-iron ratio. Also, detailed characterization studies including automated mineralogy were carried out to better understand the nature of the samples. Enhancing the chromium-to-iron ratio was achieved by using advanced spiral separators which will be discussed in this paper.
Effects of Ball Size on the Grinding Behavior of Talc Using a High-Energy Ball Mill
Authors: Kim Hyun Na , Kim Jin Woo , Kim Min Sik , Lee Bum Han , Kim Jin Cheul
Published: October 2019

The properties and preparation of talc have long been investigated due to its diverse industrial applications, which have expanded recently. However, its comminution behavior is not yet fully understood. Therefore, having better control of the particle size and properties of talc during manufacturing is required. In this study, we investigate the effect of the ball size in a high-energy ball mill on the comminution rate and particle size reduction. High-energy ball milling at 2000 rpm produces ultrafine talc particles with a surface area of 419.1 m2/g and an estimated spherical diameter of 5.1 nm. Increasing the ball size from 0.1 mm to 2 mm increases the comminution rate and produces smaller talc particles. The delamination of (00l) layers is the main comminution behavior when using 1 mm and 2 mm balls, but both the delamination and rupture of (00l) layers occurs when using 0.1 mm balls. The aggregation behavior of ground talc is also affected by the ball size. Larger aggregations form in aqueous solution when ground with 0.1 mm balls than with 1 mm or 2 mm balls, which highlights the different hydro-phobicities of ground talc. The results indicate that optimizing the ball size facilitates the formation of talc particles of a suitable size, crystallinity, and aggregation properties.
Characterization of Diatomaceous Earth and Halloysite Resources of Poland
Authors: Lutyński Marcin , Sakiewicz Piotr , Lutyńska Sylwia
Published: October 2019

The mining industry of Poland is based mostly on coal and copper ores. Strict carbon emissions and the depletion of deposits will slowly phase out coal. Therefore, metallic ores and other mineral raw materials will dominate the extractive industry of Poland. Current measured resources of the largest deposits of halloysite and diatomaceous earth in Poland are over 0.5 Mt and 10 Mt, respectively. Halloysite and diatomaceous earth samples from halloysite Dunino deposits and Jawornik diatomaceous earth deposits (composed mostly of diatomaceous skeletons (frustules)) were subjected to mineralogical analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) nanostructural, chemical, elemental, and mineral content analysis. Both these minerals have similar properties, i.e., sorption capacity and cation exchange capacity, and are used mostly for the same purposes, e.g., adsorbents, filler material, and filtration. Samples of Dunino halloysite consist of minerals such as halloysite, kaolinite, hematite, magnetite, quartz, magnesioferrite, rutile, ilmenite, geikielite, goyazite, gorceixite, and crandallite, with little impurities in the form of iron oxides. Occasionally, halloysite nanoplates (HNP) nanotubes (HNT) were found. Diatomaceous earth is composed mainly of silica-containing phases (quartz, opal) and clay minerals (illite and kaolinite). The frustules of diatoms are mostly centric (discoid) and have radius values of approximately 50–60 μm. Large resources of these minerals could be used in the future either for manufacturing composite materials or highly advanced adsorbents.
Accurate Calculation Procedure for V-x Parameters of Hydrothermal Gold Ore Fluid Inclusions
Authors: Yang Shixiang , Sun Rui , Liu Xiqiang , Liu Zhao , Wen Jingyuan
Published: October 2019

Determining the V-x parameters of H2O–NaCl–CO2 fluid inclusions (total density of inclusions, gas content, homogenization pressure, etc.) is of great value for the exploration of hydrothermal deposits. However, previous accurate calculation methods are only applicable to H2O–NaCl–CO2 fluid inclusions with homogenization temperature above 300 °C and CO2 phase homogenization temperature above the CO2 clathrate melting temperature. In this paper, a new calculation method is proposed to accurately solve the V-x parameters of H2O–NaCl–CO2 fluid inclusions with complete homogenization temperature lower than 300 °C. The algorithm first determines the salinity of inclusions with respect to the melting temperature of CO2 clathrate and the partial homogenization temperature of the CO2 phase and then determines the internal pressure of inclusions when CO2 clathrate is completely melted. The V-x parameters of the inclusions are then iteratively solved. The new algorithm does not require a visual estimation of the volume fraction of the CO2 phase as an input parameter. It is possible to avoid the significant error brought about by traditional method of calculating the inclusion V-x parameters involving visual estimation of the CO2 phase volume fraction. A computer program is developed on the basis of the new method and is applied to the analysis of fluid inclusions in medium and low temperature hydrothermal gold ore.
Readable High-Speed Racetrack Memory Based on an Antiferromagnetically Coupled Soft/Hard Magnetic Bilayer
Authors: Yu Ziyang , Wei Chenhuinan , Yi Fan , Xiong Rui
Published: October 2019

The current-induced domain wall (DW) motion in a racetrack memory with a synthetic antiferromagnets (SAFs) structure has attracted attention because of the ultrahigh velocity of the DW. However, since there is little stray field due to the zero net magnetization in a pair of antiferromagnetically (AFM) coupled domains, how to read the information stored in the pair of domains is still challenging. In the present work, we propose a readable SAF racetrack memory composed of two ferromagnetic (FM) layers with distinct uniaxial-anisotropy constants. As a result, a region of staggered domains formed between two neighboring DWs in the two layers. In this region, there is a parallel alignment of the moments in the two FM layers. This parallel magnetization is readable and can be exploited to label the structure of the nearby AFM-coupled domains for the racetrack with DWs moving in a fixed direction. This function can be realized by connecting a Schmitt Trigger to a sensor for reading. The stability and the length of the staggered region can be well-tuned by changing the magnetic parameters, such as the interlayer exchange coupling constants, the Dzyaloshinskii–Moriya interaction (DMI) constants, and the uniaxial-anisotropy constants of the two FM layers, in a range that is experimentally achievable.
Easily Synthesized Polyaniline@Cellulose Nanowhiskers Better Tune Network Structures in Ag-Based Adhesives: Examining the Improvements in Conductivity, Stability, and Flexibility
Authors: Cao Ge , Gao Xiaolan , Wang Linlin , Cui Huahua , Lu Junyi , Meng Yuan , Xue Wei , Cheng Chun , Tian Yanhong , Tian Yanqing
Published: October 2019

It is essential to develop a novel and versatile strategy for constructing electrically conductive adhesives (ECAs) that have superior conductivity and high mechanical properties. In this work, easily synthesized polyaniline@cellulose (PANI@CNs) nanowhiskers with a high aspect ratio and excellent solubility in 1,4-dioxane were prepared and added to conventional Ag-containing adhesives. A small amount of PANI@CNs can dramatically tune the structure of the ECAs’ conductive network and significantly improve the conductivity of the ECAs. Good solubility of PANI@CNs in solvents brings excellent dispersion in the polymer matrix. Thus, a three-dimensional (3D) conducting network formed with dispersed PANI@CNs and Ag flakes can enhance the conductivity of ECAs. The conductivity of the ECAs (with 1.5 wt% PANI@CNs and 55 wt% Ag flakes) showed three orders of magnitude higher than that of the ECAs filled with 55 wt% Ag flakes and 65 wt% Ag flakes. Meanwhile, the integration of PANI@CNs with Ag flakes in polymer matrices also significantly enhanced the mechanical compliance of the resulted ECAs. The resistivity remained unchanged after rolling the PANI@CNs-containing ECAs’ film into a 4 mm bending radius for over 1500 cycles. A bendable printed circuit was fabricated using the above PANI@CNs-containing ECAs, which demonstrated their future potential in the field of flexible electronics.
Effects of Zerovalent Iron Nanoparticles on Photosynthesis and Biochemical Adaptation of Soil-Grown Arabidopsis thaliana
Authors: Yoon Hakwon , Kang Yu-Gyeong , Chang Yoon-Seok , Kim Jae-Hwan
Published: October 2019

Nanoscale zerovalent iron (nZVI) is the most widely used nanomaterial for environmental remediation. The impacts of nZVI on terrestrial organisms have been recently reported, and in particular, plant growth was promoted by nZVI treatment in various concentrations. Therefore, it is necessary to investigate the detailed physiological and biochemical responses of plants toward nZVI treatment for agricultural application. Here, the effects of nZVI on photosynthesis and related biochemical adaptation of soil-grown Arabidopsis thaliana were examined. After treatment with 500 mg nZVI/kg soil, the plant biomass increased by 38% through enhanced photosynthesis, which was confirmed by the gas-exchange system, carbon isotope ratio and chlorophyll content analysis. Besides, the iron uptake of the plant increased in roots and leaves. The magnetic property measurements and transmission electron microscopy showed that the transformed particles were accumulated in parts of the plant tissues. The accumulation of carbohydrates such as glucose, sucrose and starch increased by the enhanced photosynthesis, and photosynthetic-related inorganic nutrients such as phosphorus, manganese and zinc maintained homeostasis, according to the increased iron uptake. These findings suggest that nZVI has additional or alternative benefits as a nano-fertilizer and a promoter of CO2 uptake in plants.
Nanotechnology in Oral Cavity Carcinoma: Recent Trends and Treatment Opportunities
Authors: De Felice Francesca , Cavallini Costanza , Barlattani Alberta , Tombolini Mario , Brugnoletti Orlando , Tombolini Vincenzo , Polimeni Antonella
Published: October 2019

Oral cavity carcinoma (OCC) remains an ongoing public health problem. Emerging nanotechnology provides alternative treatment approaches. This review covers the up-to-date literature in the human OCC treatment field. We explored the growing body of evidence to reveal novel and highly promising diagnostic and therapeutic applications of nanotechnology in this field. Various types of nanoparticles have been tested for applications in OCC. Imaging modalities in addition to nanocarriers are discussed. The encouraging contribution of lymphotropic nanoparticles contrast in the diagnosis of metastatic cervical lymph nodes needs to be confirmed. The development of the sentinel lymph node procedure and photodynamic therapy may lead to breakthrough therapies in order improve clinical outcomes and quality of life. In this perspective, cancer nanotechnology has the potential to revolutionize the treatment of OCC patients.
Biocompatible Polymer Materials with Antimicrobial Properties for Preparation of Stents
Authors: Škrlová Kateřina , Malachová Kateřina , Muñoz-Bonilla Alexandra , Měřinská Dagmar , Rybková Zuzana , Fernández-García Marta , Plachá Daniela
Published: October 2019

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient’s body, which presents a number of complications and can also endanger the patient’s life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.