bluuebunny/crossref_metadata_2025 huggingface dataset:
Progress towards Stable and High-Performance Polyelectrolyte Multilayer Nanofiltration Membranes for Future Wastewater Treatment Applications
Authors: Bóna Áron , Galambos Ildikó , Nemestóthy Nándor
Published: March 2023

The increasing demand for nanofiltration processes in drinking water treatment, industrial separation and wastewater treatment processes has highlighted several shortcomings of current state-of-the-art thin film composite (TFC NF) membranes, including limitations in chemical resistance, fouling resistance and selectivity. Polyelectrolyte multilayer (PEM) membranes provide a viable, industrially applicable alternative, providing significant improvements in these limitations. Laboratory experiments using artificial feedwaters have demonstrated selectivity an order of magnitude higher than polyamide NF, significantly higher fouling resistance and excellent chemical resistance (e.g., 200,000 ppmh chlorine resistance and stability over the 0–14 pH range). This review provides a brief overview of the various parameters that can be modified during the layer-by-layer procedure to determine and fine-tune the properties of the resulting NF membrane. The different parameters that can be adjusted during the layer-by-layer process are presented, which are used to optimize the properties of the resulting nanofiltration membrane. Substantial progress in PEM membrane development is presented, particularly selectivity improvements, of which the most promising route seems to be asymmetric PEM NF membranes, offering a breakthrough in active layer thickness and organic/salt selectivity: an average of 98% micropollutant rejection coupled with a NaCl rejection below 15%. Advantages for wastewater treatment are highlighted, including high selectivity, fouling resistance, chemical stability and a wide range of cleaning methods. Additionally, disadvantages of the current PEM NF membranes are also outlined; while these may impede their use in some industrial wastewater applications, they are largely not restrictive. The effect of realistic feeds (wastewaters and challenging surface waters) on PEM NF membrane performance is also presented: pilot studies conducted for up to 12 months show stable rejection values and no significant irreversible fouling. We close our review by identifying research areas where further studies are needed to facilitate the adoption of this notable technology.
Application of Photo-Fenton-Membrane Technology in Wastewater Treatment: A Review
Authors: Liang Lihua , Ji Lin , Ma Zhaoyan , Ren Yuanyuan , Zhou Shuyu , Long Xinchang , Cao Chenyang
Published: March 2023

Photo-Fenton coupled with membrane (photo-Fenton-membrane) technology offers great potential benefits in future wastewater treatment because it can not only degrade refractory organics, but also separate different pollutants from water; additionally, it often has a membrane-self-cleaning ability. In this review, three key factors of photo-Fenton-membrane technology, photo-Fenton catalysts, membrane materials and reactor configuration, are presented. Fe-based photo-Fenton catalysts include zero-valent iron, iron oxides, Fe-metal oxides composites and Fe-based metal–organic frameworks. Non-Fe-based photo-Fenton catalysts are related to other metallic compounds and carbon-based materials. Polymeric and ceramic membranes used in photo-Fenton-membrane technology are discussed. Additionally, two kinds of reactor configurations, immobilized reactor and suspension reactor, are introduced. Moreover, we summarize the applications of photo-Fenton-membrane technology in wastewater, such as separation and degradation of pollutants, removal of Cr(VI) and disinfection. In the last section, the future prospects of photo-Fenton-membrane technology are discussed.
Interaction of Uperin Peptides with Model Membranes: Molecular Dynamics Study
Authors: Ermakova Elena A. , Kurbanov Rauf Kh.
Published: March 2023

The interaction of antimicrobial and amyloid peptides with cell membranes is a critical step in their activities. Peptides of the uperin family obtained from the skin secretion of Australian amphibians demonstrate antimicrobial and amyloidogenic properties. All-atomic molecular dynamics and an umbrella sampling approach were used to study the interaction of uperins with model bacterial membrane. Two stable configurations of peptides were found. In the bound state, the peptides in helical form were located right under the head group region in parallel orientation with respect to the bilayer surface. Stable transmembrane configuration was observed for wild-type uperin and its alanine mutant in both alpha-helical and extended unstructured forms. The potential of mean force characterized the process of peptide binding from water to the lipid bilayer and its insertion into the membrane, and revealed that the transition of uperins from the bound state to the transmembrane position was accompanied by the rotation of peptides and passes through the energy barrier of 4–5 kcal/mol. Uperins have a weak effect on membrane properties.
Mango Peel Nanofiltration Concentrates to Enhance Anaerobic Digestion of Slurry from Piglets Fed with Laminaria
Authors: Macedo Antónia , Fragoso Rita , Silva Inês , Gomes Tânia , Martins Cátia F. , Freire João Bengala , Duarte Elizabeth
Published: March 2023

The environmental impact of biowaste generated during animal production can be mitigated by applying a circular economy model: recycling, reinventing the life cycle of biowaste, and developing it for a new use. The aim of this study was to evaluate the effect of adding sugar concentrate solutions obtained from the nanofiltration of fruit biowaste (mango peel) to slurry from piglets fed with diets incorporating macroalgae on biogas production performance. The nanofiltration of ultrafiltration permeates from aqueous extracts of mango peel was carried out using membranes with a molecular weight cut-off of 130 Da until a volume concentration factor of 2.0 was reached. A slurry resulting from piglets fed with an alternative diet with the incorporation of 10% Laminaria was used as a substrate. Three different trials were performed sequentially: (i) a control trial (AD0) with faeces resulting from a cereal and soybean-meal-based diet (S0); (ii) a trial with S1 (10% L. digitata) (AD1), and (iii) an AcoD trial to assess the effect of the addition of a co-substrate (20%) to S1 (80%). The trials were performed in a continuous-stirred tank reactor (CSTR) under mesophilic conditions (37.0 ± 0.4 °C), with a hydraulic retention time (HRT) of 13 days. The specific methane production (SMP) increased by 29% during the anaerobic co-digestion process. These results can support the design of alternative valorisation routes for these biowastes, contributing to sustainable development goals.
Synthesis and Characterisation of Self-Cleaning TiO2/PES Mixed Matrix Membranes in the Removal of Humic Acid
Authors: Poon Yan Kee , Enche Ab Rahim Siti Kartini , Ng Qi Hwa , Hoo Peng Yong , Abdullah Nur Yasmin , Nasib Amira , Abdullah Norazharuddin Shah
Published: March 2023

Membrane application is widespread in water filtration to remove natural organic matter (NOM), especially humic acid. However, there is a significant concern in membrane filtration, which is fouling, which will cause a reduction in the membrane life span, a high energy requirement, and a loss in product quality. Therefore, the effect of a TiO2/PES mixed matrix membrane on different concentrations of TiO2 photocatalyst and different durations of UV irradiation was studied in removing humic acid to determine the anti-fouling and self-cleaning effects. The TiO2 photocatalyst and TiO2/PES mixed matrix membrane synthesised were characterised using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), contact angle, and porosity. The performances of TiO2/PES membranes of 0 wt.%, 1 wt.%, 3 wt.%, and 5 wt.% were evaluated via a cross-flow filtration system regarding anti-fouling and self-cleaning effects. After that, all the membranes were irradiated under UV for either 2, 10, or 20 min. A TiO2/PES mixed matrix membrane of 3 wt.% was proved to have the best anti-fouling and self-cleaning effect with improved hydrophilicity. The optimum duration for UV irradiation of the TiO2/PES mixed matrix membrane was 20 min. Furthermore, the fouling behaviour of mixed matrix membranes was fitted to the intermediate blocking model. Adding TiO2 photocatalyst into the PES membrane enhanced the anti-fouling and self-cleaning properties.
A Short Review on the Corrosion Behaviour of Wire and Arc Additive Manufactured Materials
Authors: Marques Davi Alves , Oliveira João Pedro , Baptista Ana Catarina
Published: March 2023

Wire and Arc Additive Manufacturing (WAAM) is a deposition rate process for the creation and/or repair of large structural metallic components. The non-equilibrium heating and cooling conditions associated with WAAM lead to the development of heterogenous microstructures. Although there is a large body of work focusing on the microstructure and mechanical properties of WAAM-fabricated components, assessment of the corrosion behaviour of alloys fabricated by WAAM is still in its infancy. In this review, the current body of knowledge associated with the corrosion behaviour of different WAAM-fabricated engineering alloys is presented and discussed. Future perspectives and potential research topics are also presented. This is the first review work focusing on the corrosion of wire and arc additive manufactured materials.
Effect of Basicity and Al2O3 Content in Slag on Cleanliness of Electroslag Ingot
Authors: Shi Xiaofang , Wang Yu , Wang Bingjie , Chang Lizhong
Published: March 2023

In order to clarify the mechanism for the increase in oxygen content during electroslag remelting, this paper analyzes in detail the effect of slag components on the gas content and number, size and composition of inclusions in electroslag ingots. The results show that, when the CaF2-MgF2-CaO-MgO-SiO2 slag system is used for electroslag remelting, the oxygen content in electroslag ingots decreases clearly with the increase in slag basicity. When the basicity is 14~3.3, the oxygen content in electroslag ingots is only 9~11 ppm. When the basicity drops to 2.3, the oxygen content increases to 20 ppm. The slag with high basicity also leads to a decrease in the number and size of inclusions with high Ca content. When the CaF2-MgF2-CaO-MgO-SiO2-Al2O3 slag system is used for electroslag remelting, with the increase in the Al2O3 content in slag with the same basicity, the oxygen content and inclusions in electroslag ingots gradually increase. However, the Al content in inclusions increases and the Ca content decreases. The decomposition of SiO2 and Al2O3 in slag is the main reason for the decrease in the cleanliness of electroslag ingots.
Efficient Recovery of Cu from Wasted CPU Sockets by Slurry Electrolysis
Authors: Chen Wenjing , Li Manning , Tang Jiancheng
Published: March 2023

In order to maximize the reuse of used electronic component resources, while reducing environmental pollution, Cu metal was recycled from wasted CPU sockets by the reformative slurry electrolysis method. However, the influences on the regulation of the Cu recovery rate and purity from waste CPU slots, by slurry electrolysis, has not been systematically elucidated in previous studies. In this work, the effects of H2SO4 concentration, slurry density, NH4Cl concentration, current density, and reaction time, on the recovery rate and purity of Cu in slurry electrolysis, were researched by systematic experimental methods. The results showed that the recycled metal elements were mainly present as powders from the cathode, rather than in the electrolyte. Moreover, the metallic elements in the cathode powder consisted of mostly Cu and small amounts of Sn and Ni. The recovery rate and purity of Cu were up to 96.19% and 93.72%, respectively, with the optimum conditions being: an H2SO4 concentration of 2 mol/L, slurry density of 30 g/L, NH4Cl concentration of 90 g/L, current density of 80 mA/cm2, and reaction time of 7 h. Compared with previous studies, the Cu recovered in this experiment was present in the cathode powder, which was more convenient for the subsequent processing. Meanwhile, the recovery rate of Cu was effectively improved. This is an important guideline for the subsequent application of slurry electrolysis for Cu recovery.
Evaluation of GC/MS-Based 13C-Positional Approaches for TMS Derivatives of Organic and Amino Acids and Application to Plant 13C-Labeled Experiments
Authors: Dellero Younès , Filangi Olivier , Bouchereau Alain
Published: March 2023

Analysis of plant metabolite 13C-enrichments with gas-chromatography mass spectrometry (GC/MS) has gained interest recently. By combining multiple fragments of a trimethylsilyl (TMS) derivative, 13C-positional enrichments can be calculated. However, this new approach may suffer from analytical biases depending on the fragments selected for calculation leading to significant errors in the final results. The goal of this study was to provide a framework for the validation of 13C-positional approaches and their application to plants based on some key metabolites (glycine, serine, glutamate, proline, α-alanine and malate). For this purpose, we used tailor-made 13C-PT standards, harboring known carbon isotopologue distributions and 13C-positional enrichments, to evaluate the reliability of GC-MS measurements and positional calculations. Overall, we showed that some mass fragments of proline_2TMS, glutamate_3TMS, malate_3TMS and α-alanine_2TMS had important biases for 13C measurements resulting in significant errors in the computational estimation of 13C-positional enrichments. Nevertheless, we validated a GC/MS-based 13C-positional approach for the following atomic positions: (i) C1 and C2 of glycine_3TMS, (ii) C1, C2 and C3 of serine_3TMS, and (iii) C1 of malate_3TMS and glutamate_3TMS. We successfully applied this approach to plant 13C-labeled experiments for investigating key metabolic fluxes of plant primary metabolism (photorespiration, tricarboxylic acid cycle and phosphoenolpyruvate carboxylase activity).
Usefulness of Oral Fluid for Measurement of Methylone and Its Metabolites: Correlation with Plasma Drug Concentrations and the Effect of Oral Fluid pH
Authors: Sprega Giorgia , Di Giorgi Alessandro , Poyatos Lourdes , Papaseit Esther , Pérez-Mañá Clara , Tini Anastasio , Pichini Simona , Busardò Francesco Paolo , Lo Faro Alfredo Fabrizio , Farré Magí
Published: March 2023

The aim of this study was to investigate methylone and its metabolites concentration in oral fluid following controlled increasing doses, focusing on the effect of oral fluid pH. Samples were obtained from a clinical trial where twelve healthy volunteers participated after ingestion of 50, 100, 150 and 200 mg of methylone. Concentration of methylone and its metabolites 4-hydroxy-3-methoxy-N-methylcathinone (HMMC) and 3,4-methylenedioxycathinone in oral fluid were measured using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Pharmacokinetic parameters were estimated, and the oral fluid-to-plasma ratio (OF/P) at each time interval was calculated and correlated with the oral fluid pH using data from our previous study in plasma. Methylone was detected at all time intervals after each dose; MDC and HMMC were not detectable after the lowest dose. Oral fluid concentrations of methylone ranged between 88.3–503.8, 85.5–5002.3, 182.8–13,201.8 and 214.6–22,684.6 ng/mL following 50, 100, 150 and 200 mg doses, respectively, peaked between 1.5 and 2.0 h, and were followed by a progressive decrease. Oral fluid pH was demonstrated to be affected by methylone administration. Oral fluid is a valid alternative to plasma for methylone determination for clinical and toxicological studies, allowing for a simple, easy and non-invasive sample collection.
Design and Parameter Identification for a Positioning Platform with a Large Stroke and High Precision for Segmented Mirrors
Authors: Yin Zihao , Qin Rongjie , Du Haoting , Zhou Weiyinuo , Sun Jialin , Sun Dexin , Liu Yinnian
Published: March 2023

An active optical system with three segmented mirrors was proposed to verify the co-focus and co-phase progress. In this system, a kind of large-stroke and high-precision parallel positioning platform was specially developed to help support the mirrors and reduce the error between them, which can move in three degrees of freedom out of plane. The positioning platform was composed of three flexible legs and three capacitive displacement sensors. For the flexible leg, a kind of forward-type amplification mechanism was specially designed to amplify the displacement of the piezoelectric actuator. The output stroke of the flexible leg was no less than 220 μm and the step resolution was up to 10 nm. Further, a linear model was established to identify the amplification ratio between the actuator and the flexible leg, which can increase the precision of the positioning platform. Moreover, three capacitive displacement sensors with a resolution of 2.5 nm were symmetrically installed in the platform to accurately measure the position and attitude of the platform. To improve the stability and precision of the platform, particle swarm optimization algorithm was applied to identify the control matrix, which can help the platform achieve ultra-high precision positioning. The results showed that the theoretical matrix parameters had a maximum deviation of 5.67% from the experimental ones. Finally, abundant experiments verified the excellent and stable performance of the platform. The results proved that while bearing the heavy mirror, which is no more than 5 kg, the platform can realize a 220 μm translation stroke and 2.0 mrad deflection stroke, with a high step resolution of 20 nm and 0.19 μrad. These indicators can perfectly cater to the requirements of the proposed segmented mirror system’s co-focus and co-phase adjustment progress.
A New Inner Fabrication Method of Internal Cavity in Metal under Compound Acoustic Fields
Authors: Zhang Zheng , Wu Liqun , Wang Yaxing , Wang Ze’en , Wu Guanwu , Wang Yajing , Wang Hongcheng
Published: March 2023

In order to realize direct manufacturing of cavity inside metal without assembly, this paper investigates the mechanism of cavity manufacturing inside metals under compound acoustic fields. First, a local acoustic cavitations model is established to study the single bubble generation at fixed point in Ga-In metal droplets, which has a low melting point. Second, cavitation-levitation acoustic composite fields are integrated with the experimental system for simulation and experimentation. Through COMSOL simulation and experimentation, this paper expounds the manufacturing mechanism of metal internal cavity under acoustic composite fields. The key problem is to control the duration of the cavitation bubble by controlling the driving acoustic pressure’s frequency and the magnitude of ambient acoustic pressure. Under the condition of composite acoustic fields, this method realizes the direct fabrication of cavity inside Ga-In alloy for the first time.
Identification and Characterization of Rhipicephalus microplus ATAQ Homolog from Haemaphysalis longicornis Ticks and Its Immunogenic Potential as an Anti-Tick Vaccine Candidate Molecule
Authors: Adjou Moumouni Paul Franck , Naomasa Souichirou , Tuvshintulga Bumduuren , Sato Nariko , Okado Kiyoshi , Zheng Weiqing , Lee Seung-Hun , Mosqueda Juan , Suzuki Hiroshi , Xuan Xuenan , Umemiya-Shirafuji Rika
Published: March 2023

Although vaccines are one of the environmentally friendly means to prevent the spread of ticks, there is currently no commercial vaccine effective against Haemaphysalis longicornis ticks. In this study, we identified, characterized, localized, and evaluated the expression patterns, and tested the immunogenic potential of a homologue of Rhipicephalus microplus ATAQ in H. longicornis (HlATAQ). HlATAQ was identified as a 654 amino acid-long protein present throughout the midgut and in Malpighian tubule cells and containing six full and one partial EGF-like domains. HlATAQ was genetically distant (homology < 50%) from previously reported ATAQ proteins and was expressed throughout tick life stages. Its expression steadily increased (p < 0.001) during feeding, reached a peak, and then decreased slightly with engorgement. Silencing of HlATAQ did not result in a phenotype that was significantly different from the control ticks. However, H. longicornis female ticks fed on a rabbit immunized with recombinant HlATAQ showed significantly longer blood-feeding periods, higher body weight at engorgement, higher egg mass, and longer pre-oviposition and egg hatching periods than control ticks. These findings indicate that the ATAQ protein plays a role in the blood-feeding-related physiological processes in the midgut and Malpighian tubules and antibodies directed against it may affect these tissues and disrupt tick engorgement and oviposition.
Clinical and Microbiological Features of Fulminant Haemolysis Caused by Clostridium perfringens Bacteraemia: Unknown Pathogenesis
Authors: Suzaki Ai , Hayakawa Satoshi
Published: March 2023

Bacteraemia brought on by Clostridium perfringens has a very low incidence but is severe and fatal in fifty per cent of cases. C. perfringens is a commensal anaerobic bacterium found in the environment and in the intestinal tracts of animals; it is known to produce six major toxins: α-toxin, β-toxin, ε-toxin, and others. C. perfringens is classified into seven types, A, B, C, D, E, F and G, according to its ability to produce α-toxin, enterotoxin, and necrotising enterotoxin. The bacterial isolates from humans include types A and F, which cause gas gangrene, hepatobiliary infection, and sepsis; massive intravascular haemolysis (MIH) occurs in 7–15% of C. perfringens bacteraemia cases, resulting in a rapid progression to death. We treated six patients with MIH at a single centre in Japan; however, unfortunately, they all passed away. From a clinical perspective, MIH patients tended to be younger and were more frequently male; however, there was no difference in the toxin type or genes of the bacterial isolates. In MIH cases, the level of θ-toxin in the culture supernatant of clinical isolates was proportional to the production of inflammatory cytokines in the peripheral blood, suggesting the occurrence of an intense cytokine storm. Severe and systemic haemolysis is considered an evolutionary maladaptation as it leads to the host’s death before the bacterium obtains the benefit of iron utilisation from erythrocytes. The disease’s extraordinarily quick progression and dismal prognosis necessitate a straightforward and expedient diagnosis and treatment. However, a reliable standard of diagnosis and treatment has yet to be put forward due to the lack of sufficient case analysis.
Use of Different Nutrients to Improve the Fermentation Performances of Lactiplantibacillus pentosus OM13 during the Production of Sevillian Style Green Table Olives
Authors: Alfonzo Antonio , Naselli Vincenzo , Gaglio Raimondo , Settanni Luca , Corona Onofrio , La Croce Francesco , Vagnoli Paola , Krieger-Weber Sibylle , Francesca Nicola , Moschetti Giancarlo
Published: March 2023

The aim of this study was to evaluate the fermentation performance of the commercial starter Lactiplantibacillus pentosus OM13 with four nutrients (A, B, C, and D) that differed in the following ingredients: starch, sugars, maltodextrin, inactivated yeast, inactivated yeast rich in amino acids, inactivated yeast rich in mannoproteins, and salt (NaCl). For this purpose, six different experimental productions of Nocellara del Belice table olives were carried out. During transformation, the fermentation process was monitored by measuring pH and plate counts for lactic acid bacteria (LAB), yeasts, Enterobacteriaceae, Staphylococcaceae, and Pseudodomondaceae populations. At the end of the production process, each trial was subjected to volatile organic compound analysis and sensory evaluation. The addition of the different nutrients resulted in a significant reduction in pH (around 2.5 points) after 3 days of fermentation. At the same time, a significant increase in the number of LAB populations (> 6.6 log CFU/mL) was observed for all trials. Volatile organic compound (VOC) analysis revealed the presence of 39 compounds. In this study, nutrient C was optimal for improving the fermentation activity of L. pentosus OM13. These results provide elements for the implementation of experimental protocols to reduce product losses and improve sensory characteristics.
Microbiological Hazards Associated with the Use of Oligocene Waters: A Study of Water Intakes in Warsaw, Poland
Authors: Karwowska Ewa , Miaśkiewicz-Pęska Ewa , Gołębiewska Katarzyna , Tomaszewska Paulina
Published: March 2023

Oligocene waters are widely recognized as excellent sources of drinking water. Due to the belief in their good quality, the water from Oligocene intakes in Warsaw, Poland, is made available to users without prior treatment or disinfection. The present study aimed at assessing possible microbiological risks associated with the use of this water. The occurrence of microbiological contaminants in selected intakes was evaluated, in addition to an assessment of possible changes in the microbiological quality of the water under typical storage conditions. The possibility of antibiotic resistance in bacteria isolated from Oligocene water samples was also investigated, as was their sensitivity to selected disinfectants. A small number of bacteria—27.0 ± 60.8 CFU/cm3 and 3.0 ± 3.0 CFU/cm3—were found in Oligocene water intakes for psychrophilic and mesophilic bacteria, respectively. Fecal bacteria were not detected. Bacteria present in Oligocene waters showed the ability to multiply intensively during standard water storage; this was especially true for mesophilic bacteria in water stored at room temperature. In some samples, bacterial counts reached 103–104 CFU/cm3 after 48 h. Almost all bacterial isolates were resistant to the commonly used antibiotics: ampicillin, vancomycin and rifampicin. The bacteria were also insensitive to some disinfectants.
The Thioredoxin System in Edwardsiella piscicida Contributes to Oxidative Stress Tolerance, Motility, and Virulence
Authors: He Jiaojiao , Liu Su , Fang Qingjian , Gu Hanjie , Hu Yonghua
Published: March 2023

Edwardsiella piscicida is an important fish pathogen that causes substantial economic losses. In order to understand its pathogenic mechanism, additional new virulence factors need to be identified. The bacterial thioredoxin system is a major disulfide reductase system, but its function is largely unknown in E. piscicida. In this study, we investigated the roles of the thioredoxin system in E. piscicida (named TrxBEp, TrxAEp, and TrxCEp, respectively) by constructing a correspondingly markerless in-frame mutant strain: ΔtrxB, ΔtrxA, and ΔtrxC, respectively. We found that (i) TrxBEp is confirmed as an intracellular protein, which is different from the prediction made by the Protter illustration; (ii) compared to the wild-type strain, ΔtrxB exhibits resistance against H2O2 stress but high sensitivity to thiol-specific diamide stress, while ΔtrxA and ΔtrxC are moderately sensitive to both H2O2 and diamide conditions; (iii) the deletions of trxBEp, trxAEp, and trxCEp damage E. piscicida’s flagella formation and motility, and trxBEp plays a decisive role; (iv) deletions of trxBEp, trxAEp, and trxCEp substantially abate bacterial resistance against host serum, especially trxBEp deletion; (v) trxAEp and trxCEp, but not trxBEp, are involved in bacterial survival and replication in phagocytes; (vi) the thioredoxin system participates in bacterial dissemination in host immune tissues. These findings indicate that the thioredoxin system of E. piscicida plays an important role in stress resistance and virulence, which provides insight into the pathogenic mechanism of E. piscicida.
Recent Progress of Reclassification of the Genus Streptomyces
Authors: Komaki Hisayuki
Published: March 2023

The genus Streptomyces is a representative group of actinomycetes and one of the largest taxa in bacteria, including approximately 700 species with validly published names. Since the classification was mainly based on phenotypic characteristics in old days, many members needed to be reclassified according to recent molecular-based taxonomies. Recent developments of molecular-based analysis methods and availability of whole genome sequences of type strains enables researchers to reclassify these phylogenetically complex members on a large scale. This review introduces reclassifications of the genus Streptomyces reported in the past decade. Appropriately 34 Streptomyces species were transferred to the other genera, such as Kitasatospora, Streptacidiphilus, Actinoalloteichus and recently proposed new genera. As a result of reclassifications of 14 subspecies, the genus Streptomyces includes only four subspecies at present in practice. A total of 63 species were reclassified as later heterotypic synonyms of previously recognized species in 24 published reports. As strong relationships between species and the secondary metabolite-biosynthetic gene clusters become clarified, appropriate classifications of this genus will not only contribute to systematics, but also provide significant information when searching for useful bioactive substances.
The Hydroponic Rockwool Root Microbiome: Under Control or Underutilised?
Authors: Thomas Phil , Knox Oliver G. G. , Powell Jeff R. , Sindel Brian , Winter Gal
Published: March 2023

Land plants have an ancient and intimate relationship with microorganisms, which influences the composition of natural ecosystems and the performance of crops. Plants shape the microbiome around their roots by releasing organic nutrients into the soil. Hydroponic horticulture aims to protect crops from damaging soil-borne pathogens by replacing soil with an artificial growing medium, such as rockwool, an inert material made from molten rock spun into fibres. Microorganisms are generally considered a problem to be managed, to keep the glasshouse clean, but the hydroponic root microbiome assembles soon after planting and flourishes with the crop. Hence, microbe–plant interactions play out in an artificial environment that is quite unlike the soil in which they evolved. Plants in a near-ideal environment have little dependency on microbial partners, but our growing appreciation of the role of microbial communities is revealing opportunities to advance practices, especially in agriculture and human health. Hydroponic systems are especially well-suited to active management of the root microbiome because they allow complete control over the root zone environment; however, they receive much less attention than other host–microbiome interactions. Novel techniques for hydroponic horticulture can be identified by extending our understanding of the microbial ecology of this unique environment.
Soil Contaminated with Hazardous Waste Materials at Rio Tinto Mine (Spain) Is a Persistent Secondary Source of Acid and Heavy Metals to the Environment
Authors: Fernández-Landero Sandra , Fernández-Caliani Juan Carlos , Giráldez María Inmaculada , Morales Emilio , Barba-Brioso Cinta , González Isabel
Published: March 2023

Mineralogical analysis and laboratory-based leaching tests coupled with speciation modeling were undertaken to quantify the potential for short-term acid generation and the release of trace elements from soils heavily contaminated with mine waste at Rio Tinto. Three different waste materials were considered as case studies: roasted pyrite, copper slags, and leached sulfide ores. The results showed elevated values of net acid generation (up to 663 mmol H+/kg), the major pools being potential sulfidic acidity and acidity retained in jarosite. Remarkable contents of As and toxic heavy metals were found especially in the slag-contaminated soil. Copper, Zn, and Pb were the most abundant metals in the acid leach solutions resulting from mine soil-water interaction, with peak values of 55.6 mg L−1, 2.77 mg L−1, and 2.62 mg L−1, respectively. Despite the high total contents of trace elements occurring in soil, the mobile fraction was limited to maximum release values of 12.60% for Cd and 10.27% for Cu, according to the test leaching. Speciation calculations indicated that free metal ions (M2+) and sulfate species (MSO40) accounted for most of the dissolved load. Acid soil drainage is a secondary source of acid and heavy metals in the mine site and, therefore, an effective land reclamation program should ensure that acidity and metal mobility are reduced to environmentally sustainable levels.
Influence of Sodium Hexametaphosphate on Muscovite Grinding and Its Mechanism Analysis
Authors: Fan Chenyu , Ren Liuyi , Zhang Yimin , Bao Shenxu , Yang Zhilu
Published: March 2023

In this paper, different doses of sodium hexametaphosphate (SHMP) were added as grinding aids in the process of muscovite grinding, and the effect of SHMP on the grinding efficiency of muscovite was studied. The grinding experiment results show that the grinding efficiency increases significantly with the increase in SHMP dosage. The mechanism of SHMP improving the grinding efficiency of muscovite was analyzed by various test methods. Experimental results showed that when SHMP was used as a grinding aid, the ordered structure of muscovite crystals was destroyed, the surface of muscovite was roughened, and obvious cracks appeared. SHMP was physically adsorbed on the muscovite powder, which effectively improved the pulp environment of muscovite powder during grinding, resulting in more dispersed muscovite powder, and improved the grinding efficiency. This study provides theoretical guidance for the efficient preparation of fine-grained muscovite powder and the action mechanism of grinding aids.
Magmatic-Hydrothermal Fluid Processes of the Sn-W Granites in the Maniema Province of the Kibara Belt (KIB), Democratic Republic of Congo
Authors: Makutu Douxdoux Kumakele , Seo Jung Hun , Lee Insung , Oh Jihye , Kang Pilmo , Ongendangenda Albert Tienge , Makoka Frederic Mwanza
Published: March 2023

The Kibara belt (KIB) in the Maniema province hosts orebodies bearing cassiterite-wolframite, which are associated with equigranular to pegmatitic late Mesoproterozoic (1094–755 Ma) granites and Sn-W bearing quartz veins that cut through metasedimentary country rocks. Alteration assemblages of muscovite-quartz (±topaz-fluorite-tourmaline) occur in the granites, and muscovite-sericite-quartz occurs in Sn-W quartz veins. Petrographic analyses, including cathodoluminescence (SEM-CL) on cassiterite grains, reveal two types of cassiterite: yellow transparent cassiterite (lighter under SEM-CL: type I) and dark translucent cassiterite (darker under SEM-CL: type II). These types are organized in micro-textures as oscillatory (growth) zones and replacement zones (type II replaces type I). Unlike cassiterite, wolframite is texturally homogenous. LA-ICP-MS results reveal that type II cassiterite is relatively enriched in Fe, Al, Ga, In, As, Pb, Zn, and U, whereas type I is enriched in V, Ti, Zr, Ta, Hf, and Nb. Contrasting Ce anomaly values in the cassiterite types suggest a transition of redox potentials during the Sn precipitation. Fluid inclusion assemblages (FIAs) in quartz, fluorite, and cassiterite are dominantly aqueous, liquid- or vapor-rich, and rarely carbonic-bearing aqueous inclusions. These often texturally coexist in a single “boiling” assemblage in granites. Raman spectroscopy on the bubble part of fluid inclusions in quartz and cassiterite shows various gas species, including CO2, CH4, N2, and H2. Boiling assemblages in the granites suggest that fluid phase separation occurred at about 380–610 bars, which is about 1–2 km (lithostatic) or 3–5 km (hydrostatic) in apparent paleodepth. FIAs in the granites show ranges of salinities of 4–23 wt.% (NaCl equivalent) and homogenization temperatures (Th) of 190–550 °C. FIAs hosted in cassiterite displayed distinctively lower and narrower ranges of salinities of 2–10 wt.% and Th of 220–340 °C compared to the FIAs hosted in quartz in the granites (salinity of 4–23 wt.%, Th of 190–550 °C) and the quartz veins (salinity of 1–23 wt.%, Th of 130–350 °C). This suggests a less salinized and cooler fluid during the cassiterite precipitation. We suggest that magmatic-derived Sn-W bearing fluids be mixed with less saline and cooler aqueous fluids, possibly meteoric water, during the major cassiterite and possibly wolframite depositions in the KIB. This is based on (1) temperature and salinities, (2) hydrothermal alterations, (3) cassiterite micro-textures, and (4) trace element distributions.
Impacts of Mutations in the P-Loop on Conformational Alterations of KRAS Investigated with Gaussian Accelerated Molecular Dynamics Simulations
Authors: Shi Shuhua , Zheng Linqi , Ren Yonglian , Wang Ziyu
Published: March 2023

G12 mutations heavily affect conformational transformation and activity of KRAS. In this study, Gaussian accelerated molecular dynamics (GaMD) simulations were performed on the GDP-bound wild-type (WT), G12A, G12D, and G12R KRAS to probe mutation-mediated impacts on conformational alterations of KRAS. The results indicate that three G12 mutations obviously affect the structural flexibility and internal dynamics of the switch domains. The analyses of the free energy landscapes (FELs) suggest that three G12 mutations induce more conformational states of KRAS and lead to more disordered switch domains. The principal component analysis shows that three G12 mutations change concerted motions and dynamics behavior of the switch domains. The switch domains mostly overlap with the binding region of KRAS to its effectors. Thus, the high disorder states and concerted motion changes of the switch domains induced by G12 mutations affect the activity of KRAS. The analysis of interaction network of GDP with KRAS signifies that the instability in the interactions of GDP and magnesium ion with the switch domain SW1 drives the high disordered state of the switch domains. This work is expected to provide theoretical aids for understanding the function of KRAS.
Utilizing Contrast-Enhanced Ultrasonography with Phosphatidylserine Microbubbles to Detect Placental Inflammation in Rhesus Macaques
Authors: Wilson Rachel C. , Lo Jamie O. , Romero Jimenez Gabriel , Lindner Jonathan R. , Slayden Ov D. , Roberts Victoria H. J.
Published: March 2023

The ability to comprehensively monitor physiological and detect pathophysiologic processes early during pregnancy can reduce maternal and fetal morbidity and mortality. Contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technology that utilizes the acoustic detection of microbubbles to examine vascular spaces. Furthermore, microbubbles conjugated to specific compounds can focus studies on precise physiological pathways. We hypothesized that CEUS with phosphatidylserine microbubbles (MB-PS) could be employed to monitor placental inflammation. We tested this hypothesis in rhesus macaques (Macaca mulatta), a translational and relevant animal model of human placental health. As placental inflammation impacts many at-risk pregnancies, we performed CEUS with MB-PS in pregnant macaques fed a high-fat diet (e.g., a western-style diet, WSD) in the presence or absence of testosterone (T) to mimic the increased risk of polycystic ovary syndrome and subfertility. We have previously demonstrated a placental inflammation phenotype in this model, and, thus, we related the MB-PS CEUS signal intensity to placental inflammation markers: selectin p and angiopoietins. Testosterone exposure increased the MB-PS signal in the placental microcirculation on the maternal side compared to control animals. We found that T increased placental weight and decreased angiopoietin 2 (ANGPT2) immunoreactivity. Furthermore, a significant inverse correlation was found between MB-PS signal and ANGPT2. This indicated that CEUS with MB-PS can be used to monitor placental parameters. We propose that CEUS with MB-PS could aid in the identification of pregnancies at risk of placental vascular compromise.
In-Depth Performance Analysis and Comparison of Monolithic and Particulate Zwitterionic Hydrophilic Interaction Liquid Chromatography Polymer Columns
Authors: Li Haibin , Jiang Zhengjin , Desmet Gert , Cabooter Deirdre
Published: March 2023

The kinetic performance of different zwitterionic hydrophilic interaction liquid chromatography polymer columns is evaluated and compared in-depth. For this purpose, two lab-made monolithic columns, synthesized with different crosslinkers, and a commercial particle packed column are considered. It is found that performance evaluation techniques, such as comparing plate height curves or fitted A-, B- and C-terms, obtained by fitting experimental plate height data to a plate height model, are complicated by the determination of a reliable characteristic length. This is due to the very different morphology of these column types, and the heterogeneity of the monolithic columns. The occurrence of a convective flow through the packed particle column further complicates the interpretation of the obtained fitting parameters, as part of the C-term is wrongfully attributed to the A-term. Therefore, the use of the kinetic plot method is suggested for the comparative evaluation of these columns, as kinetic plots do not require the determination of a characteristic length, nor rely on any fitting parameters. With the kinetic plot method, it is demonstrated that the lab-made monolithic columns outperform the packed particle column for plate counts between 10,000 and 800,000. This is attributed to the higher column efficiency of these columns, due to their small domain and skeleton sizes, and their high permeability, resulting from their high external porosity and the occasional occurrence of preferential flow paths.
Cellular Localization of Selected Porphyrins and Their Effect on the In Vitro Motility of Human Colon Tumors and Normal Cells
Authors: Frant Maciej P. , Trytek Mariusz , Deryło Kamil , Kutyła Mateusz , Paduch Roman
Published: March 2023

Standard therapies for colorectal cancer cannot eliminate or sufficiently reduce the metastasis process. Photodynamic therapy (PDT) may be an alternative to minimizing this problem. Here, we examined the cellular localization of selected porphyrins and determined whether free-base and manganese (III) metallated porphyrins may limit colon cancer cells’ (HT29) or normal colon epithelial cells’ (CCD 841 CoTr) motility in vitro. White light irradiation was used to initiate the photodynamic effect. Porphyrin uptake by the cells was determined by porphyrin fluorescence measurements through the use of confocal microscopy. Free-base porphyrin was found in cells, where it initially localized at the edge of the cytoplasm and later in the perinuclear area. The concentrations of porphyrins had no effect on cancer cell migration but had a significant effect on normal cell motility. Due to the low concentrations of porphyrins used, no changes in F-actin filaments of the cellular cytoskeleton were detected. Signal transmission via connexons between neighbouring cells was limited to a maximum of 40 µm for HT29 and 30 µm for CCD 841 CoTr cells. The tested porphyrins differed in their activity against the tumor and normal cells’ migration capacity. Depending on the porphyrin used and the type of cells, their migration changed in relation to the control sample. The use of white light may change the activity of the porphyrins relative to the migratory capacity of the cells. The aim of the present study was to analyse the intracellular localization of tested porphyrins and their influence on the mobility of cells after irradiation with harmless white light.
Isolation and LC-QToF Characterization of Secondary Metabolites from an Endemic Plant Artemisia heptapotamica Poljak
Authors: Mukatay Umit , Samy Mamdouh Nabil , Avula Bharathi , Katragunta Kumar , Kemelbek Moldir , Zhubanova Azhar , Khan Ikhlas A. , Ross Samir Anis
Published: March 2023

Phytochemical investigation of the aerial parts of Artemisia heptapotamica Poljak led to the isolation of ten known compounds, including four alkyl p-coumarates: octadecyl trans-p-coumarate (1), icosy trans-p-coumarate (2), docosyl trans-p-coumarate (3), and tetracosyl trans-p-coumarate (4), one sesquiterpene lactone: santonin (5), four flavonoids; axillarin (6), quercetin 3-O-methyl ether (7), luteolin (8), and quercetin (9), and one phenolic acid derivative: p-coumaric acid (10). The structures of the isolated compounds were identified by various spectroscopic analyses. Additionally, the antimicrobial activity of the total extract and different fractions was screened, and they exhibited no inhibition of the growth of Candida albicans, C. neoformans, Aspergillus fumigatus, methicillin-resistant Staphylococcus aureus (MRS), E. coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and Vancomycin-resistant Enterococci (VRE) at the tested concentrations ranging from 8 to 200 μg/mL. The identification and tentative characterization of the secondary metabolites were conducted using LC-QToF analysis. This method helps in the putative characterization of sesquiterpene lactones, flavonoids, coumarate derivatives, and aliphatic compounds. The developed method identified 43 compounds, of which the majority were sesquiterpene lactones, such as eudesmanolides, germacranolides, and guaianolide derivatives, followed by flavonoids. The proposed LC-QToF method helps develop dereplication strategies and understand the major class of chemicals before proceeding with the isolation of compounds.
Palladium-Catalyzed Stereoselective Construction of 1,3-Stereocenters Displaying Axial and Central Chirality via Asymmetric Alkylations
Authors: Xue Aiqi , Wei Xingfu , Huang Yue , Qu Jingping , Wang Baomin
Published: March 2023

The concurrent construction of 1,3-stereocenters remains a challenge. Herein, we report the development of stereoselective union of a point chiral center with allenyl axial chirality in 1,3-position by Pd-catalyzed asymmetric allenylic alkylation between racemic allenyl carbonates and indanone-derived β-ketoesters. Various target products bearing a broad range of functional groups were afforded in high yield (up to 99%) with excellent enantioselectivities (up to 98% ee) and good diastereoselectivities (up to 13:1 dr).
Discrepancy Study of the Chemical Constituents of Panax Ginseng from Different Growth Environments with UPLC-MS-Based Metabolomics Strategy
Authors: Sun Yizheng , Liu Xiaoyan , Fu Xiaojie , Xu Wei , Guo Qingmei , Zhang Youbo
Published: March 2023

Panax ginseng (P. ginseng), the dried root and rhizome of P. ginseng C. A. Meyer, is widely used in many fields as dietary supplements and medicine. To characterize the chemical constituents in P. ginseng cultivated in different growth environments, a UPLC-TOF-MS method was established for qualitative analysis. Four hundred and eight ginsenosides, including 81 new compounds, were characterized in P. ginseng from different regions. Among the detected compounds, 361 ginsenosides were recognized in P. ginseng cultivated in the region of Monsoon Climate of Medium Latitudes, possessing the largest amount of ginsenosides in all samples. Furthermore, 41 ginsenosides in 12 batches of P. ginsengs were quantified with a UPLC-MRM-MS method, and P. ginsengs from different regions were distinguished via chemometric analysis. This study showed that the different environments have a greater influence on P. ginseng, which laid a foundation for further quality control of the herb.