bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study of Three Dyes’ Adsorption onto Activated Carbon from Chenopodium quinoa Willd and Quillaja saponaria
Authors: Abril Diana , Ferrer Victor , Mirabal-Gallardo Yaneris , Cabrera-Barjas Gustavo , Segura Cristina , Marican Adolfo , Pereira Alfredo , Durán-Lara Esteban F. , Valdés Oscar
Published: July 2022

The present study shows porous activated carbon obtained from Chenopodium quinoa Willd and Quillaja saponaria and their use as potential adsorbents to remove three types of dyes from aqueous solutions. The adsorption results were compared with commercial charcoal to check their efficiency. All porous carbon materials were activated using carbon dioxide and steam and fully characterized. Moreover, the steam-activated samples exhibited a high total pore volume with a BET surface area of around 800 m2 g−1. Batch adsorption experiments showed that commercial charcoal is the charcoal that offered the best adsorption efficiency for tartrazine and sunset yellow FCF. However, in the case of crystal violet, all activated carbons obtained from Chenopodium quinoa Willd and Quillaja saponaria showed the best captures, outperforming commercial charcoal. Molecular dockings of the dyes on the commercial charcoal surface were performed using AutoDock Vina. The kinetic results of the three isotherm’s models for the present data follow the order: Langmuir~Freundlich > Temkin.
Study on the Properties of Fiber/Matrix Interface and Strain-Hardening Behavior of ECC Containing Municipal Solid Waste Incineration (MSWI) Powder
Authors: Dong Yun , Cheng Yongzhen , Lu Hao
Published: July 2022

In this paper, the mechanical properties of micropowder cement mortar and engineered cementitious composites (ECC), using different processing municipal solid waste incineration (MSWI) as a mineral admixture, were investigated. Through the direct ball milling method, ball milling heat treatment method, water washing ball milling method and water washing heat treatment ball milling method, the mechanical properties of MSWI bottom slag-regenerated micropowder cement mortar were tested. Compared with other groups, the flexural strength and compressive strength of the specimen prepared by the MSWI after washing and heating (750 °C, 5 h) were the highest, which reached 82.0% and 81.0% of the reference group, respectively. Based on this treatment, a uniaxial tensile test, three-point bending test and single fiber pull-out test were then carried out to explore the relevant ECC properties containing MSWI. The strain-hardening index PSH of ECC was determined by analyzing the fracture toughness and elastic modulus, fiber/matrix interface chemical bond and friction bond strength of ECC containing MSWI. The results showed that the PSH index of ECC was higher when the treated powder content was 2.2, the w/c ratio was 0.25 and the fiber volume content was 2.0%. This led to higher tensile ductility, which made it easier to achieve stable multi-slit cracking and strain-hardening behavior.
Effects of Relative Positions of Defect to Inclusion on Nanocomposite Strength
Authors: Wang Jiaqin , Tan Vincent B. C.
Published: July 2022

It is generally accepted that material inhomogeneity causes stress concentrations at the interface and thus reduces the overall strength of a composite. To overcome this reduction in strength, some groups experimented on coating the nanoinclusions with a layer of rubbery material, aiming for higher energy absorption. However, representative volume element (RVE) nanocomposite models, established with randomly distributed core–shell nanoparticles and single nanoparticle cells, show that the enhancement in strength observed in some experiments remains elusive computationally. By including a pre-existing crack in the matrix of the RVE, the stress concentration at the crack tip is reduced for cases where the nanoparticle and precrack are aligned away from the loading direction. This suggests that stress concentrations around inherent defects in materials can sometimes be reduced by adding nanoparticles to improve material strength. The effect is reversed if the crack and nanoparticle are aligned towards the loading direction. Parametric studies were also carried out in terms of the relative stiffness of the nanoparticle to the matrix and crack length. Validation tests were performed on 3D RVEs with an elliptical crack as the initial defect, and the results match with the 2D findings.
Effect of Magnesium Salt (MgCl2 and MgSO4) on the Microstructures and Properties of Ground Granulated Blast Furnace Slag (GGBFS)-Based Geopolymer
Authors: Zhang Kun , Wang Kaiqiang , Liu Zhimao , Ye Zhiwu , Zhang Baifa , Lu Deng , Liu Yi , Li Lijuan , Xiong Zhe
Published: July 2022

The use of seawater to prepare geopolymers has attracted significant research attention; however, the ions in seawater considerably influence the properties of the resulting geopolymers. This study investigated the effects of magnesium salts and alkaline solutions on the microstructure and properties of ground-granulated-blast-furnace-slag-based geopolymers. The magnesium salt–free Na2SiO4-activatied geopolymer exhibited a much higher 28 d compressive strength (63.5 MPa) than the salt-free NaOH-activatied geopolymer (31.4 MPa), with the former mainly containing an amorphous phase (C-(A)-S-H gel) and the latter containing numerous crystals. MgCl2·6H2O addition prolonged the setting times and induced halite and Cl-hydrotalcite formation. Moreover, mercury intrusion porosimetry and scanning electron microscopy revealed that the Na2SiO4-activated geopolymer containing 8.5 wt% MgCl2·6H2O exhibited a higher critical pore size (1624 nm) and consequently, a lower 28 d compressive strength (30.1 MPa) and a more loosely bound geopolymer matrix than the salt-free geopolymer. In contrast, MgSO4 addition had less pronounced effects on the setting time, mineral phase, and morphology. The Na2SiO4-activated geopolymer with 9.0 wt% MgSO4 exhibited a compressive strength of 42.8 MPa, also lower than that of the salt-free geopolymer. The results indicate that Cl− is more harmful to the GGBFS-based geopolymer properties and microstructure than SO42− is.
Predictive Modeling of Compressive Strength for Concrete at Super Early Age
Authors: Peng Xi , Zhuang Zhenxin , Yang Qiuwei
Published: July 2022

The compressive strength of concrete is an important parameter in construction practice. At present, there are few reports on the prediction model of the compressive strength of concrete at a super early age. For some engineering vibration analyses, it is very necessary to study the growth law of compressive strength of concrete at a super early age. To this end, a new prediction model is proposed in this work to analyze the variation of compressive strength for the concrete at a super early age. The innovations of this work mainly lie in two aspects. The first innovation is to propose a new compressive strength-age mathematical model to predict the variation of compressive strength more accurately. The second innovation is to develop a new robust regression analysis method to obtain the fitting parameters in the mathematical model more effectively. Using the experimental data of the super early age concrete, the proposed prediction model is compared with the existing power function model and the hyperbolic function model. The results of the comparative study show that the prediction model proposed in this work is more reasonable and reliable. Taking C40 under natural curing as an example, it has been shown from the comparative study that: (1) The total fitting error of the proposed model is approximately 60% of that of the power function model, and approximately 17% of that of the hyperbolic model; (2) The fitting standard deviation of the proposed model is approximately 49% of that of the power function model, and approximately 15% of that of the hyperbolic model; (3) The 28 day strength of concrete predicted by the proposed model is more in line with the actual strength growth law of concrete.
Approaches for Modifying Oxide-Semiconductor Materials to Increase the Efficiency of Photocatalytic Water Splitting
Authors: Grushevskaya Svetlana , Belyanskaya Irina , Kozaderov Oleg
Published: July 2022

The constant increase in the amount of energy consumed and environmental problems associated with the use of fossil fuels determine the relevance of the search for alternative and renewable energy sources. One of these is hydrogen gas, which can be produced by sunlight-driven photocatalytic water splitting. The decisive role in the efficiency of the process is played by the properties of the photocatalyst. Oxide materials are widely used as photocatalysts due to their appropriate band structure, high-enough photochemical stability and corrosion resistance. However, the bandgap, crystallinity and the surface morphology of oxide materials are subject to improvement. Apart from the properties of the photocatalyst, the parameters of the process influence the hydrogen-production efficiency. This paper outlines the key ways to improve the characteristics of oxide-semiconductor photocatalysts with the optimum parameters of photocatalytic water splitting.
Artificial Neural Networking (ANN) Model for Drag Coefficient Optimization for Various Obstacles
Authors: Rehman Khalil Ur , Çolak Andaç Batur , Shatanawi Wasfi
Published: July 2022

For various obstacles in the path of a flowing liquid stream, an artificial neural networking (ANN) model is constructed to study the hydrodynamic force depending on the object. The multilayer perceptron (MLP), back propagation (BP), and feed-forward (FF) network models were employed to create the ANN model, which has a high prediction accuracy and a strong structure. To be more specific, circular-, octagon-, hexagon-, square-, and triangular-shaped cylinders are installed in a rectangular channel. The fluid is flowing from the left wall of the channel by following two velocity profiles explicitly linear velocity and parabolic velocity. The no-slip condition is maintained on the channel upper and bottom walls. The Neumann condition is applied to the outlet. The entire physical design is mathematically regulated using flow equations. The result is presented using the finite element approach, with the LBB-stable finite element pair and a hybrid meshing scheme. The drag coefficient values are calculated by doing line integration around installed obstructions for both linear and parabolic profiles. The values of the drag coefficient are predicted with high accuracy by developing an ANN model toward various obstacles.
Reliability Analysis of a Load-Sharing k-out-of-n System Due to Its Components’ Failure
Authors: Rykov Vladimir , Ivanova Nika , Kochetkova Irina
Published: July 2022

The reliability characteristics of a k-out-of-n:F system are studied in the case when a failure of one of the system’s components leads to increasing the load on others, resulting in their residual lifetimes decreasing. The situation is modeled with the help of changing the components and the system hazard rate function. The reliability function and other reliability characteristics are calculated. Numerical examples are considered.
New Insights into Xanthophylls and Lipidomic Profile Changes Induced by Glucose Supplementation in the Marine Diatom Nitzschia laevis
Authors: Mao Xuemei , Wang Xia , Ge Mengdie , Chen Feng , Liu Bin
Published: July 2022

Nitzschia laevis is a candidate microorganism for bioactive compounds (fucoxanthin and eicosapentaenoic acid (EPA)) production. In this study, the impacts of glucose-induced trophic transition on biomass, photosynthesis, pigments, and lipid profiles were examined. The specific growth rate was increased under glucose addition, achieved at 0.47 day−1 (0.26 ± 0.01 day−1 for the group without glucose in medium). However, the photosynthetic parameters and pigments including chlorophylls, fucoxanthin, and diatoxanthin were reduced. The net yield of EPA doubled under glucose addition, reaching 20.36 ± 1.22 mg/L in 4 days. In addition, the alteration in detailed lipid molecular species was demonstrated with a focus on EPA-enriched lipids. The effects of 2-deoxyglucose (2DG) indicated that glucose phosphorylation was involved in glucose-induced regulation. These findings provide novel data for guiding the application of this diatom strain in the functional food industries.
Glucose Uptake and Oxidative Stress in Caco-2 Cells: Health Benefits from Posidonia oceanica (L.) Delile
Authors: Morresi Camilla , Vasarri Marzia , Bellachioma Luisa , Ferretti Gianna , Degl′Innocenti Donatella , Bacchetti Tiziana
Published: July 2022

Posidonia oceanica (L.) Delile is an endemic Mediterranean marine plant of extreme ecological importance. Previous in vitro and in vivo studies have demonstrated the potential antidiabetic properties of P. oceanica leaf extract. Intestinal glucose transporters play a key role in glucose homeostasis and represent novel targets for the management of diabetes. In this study, the ability of a hydroalcoholic P. oceanica leaf extract (POE) to modulate intestinal glucose transporters was investigated using Caco-2 cells as a model of an intestinal barrier. The incubation of cells with POE significantly decreased glucose uptake by decreasing the GLUT2 glucose transporter levels. Moreover, POE had a positive effect on the barrier integrity by increasing the Zonulin-1 levels. A protective effect exerted by POE against oxidative stress induced by chronic exposure to high glucose concentrations or tert-butyl hydroperoxide was also demonstrated. This study highlights for the first time the effect of POE on glucose transport, intestinal barrier integrity, and its protective antioxidant effect in Caco-2 cells. These findings suggest that the P. oceanica phytocomplex may have a positive impact by preventing the intestinal cell dysfunction involved in the development of inflammation-related disease associated with oxidative stress.
Prevalence, Radiographic Features and Clinical Relevancy of Accessory Canals of the Canalis Sinuosus in Cypriot Population: A Retrospective Cone-Beam Computed Tomography (CBCT) Study
Authors: Beyzade Zafer , Yılmaz Hasan , Ünsal Gürkan , Çaygür-Yoran Ayşe
Published: July 2022

Background and Objectives: This retrospective study aims to evaluate the prevalence, radiographic features, and clinical relevancy of the accessory canals (AC) of the canalis sinuosus (CS) in patients referred for implant surgery. Materials and Methods: Cone-beam computed tomography (CBCT) images of the patients were collected and ACs were evaluated. Age, sex, bilateral distribution, localization, diameter, distance to the buccal cortical plate, distance to the crest of the alveolar ridge, terminal ending localization, and the presence of tooth or implant were recorded. Ninety-one patients who were eligible for this study were enrolled. Results: A total of 188 ACs were found in 91 patients with 86 bilateral and 5 unilateral distributions. The mean age of the patients was 45.39. All ACs had a terminal ending at the palatal cortical border. All parameters showed a non-normal distribution; thus, the Mann–Whitney U test was preferred. Bilateral AC distribution (p = 0.761), AC distance to the crest of the alveolar ridge (p = 0.614), AC distance to the buccal cortical plate (p = 0.105), and AC diameter (p = 0.423) showed no significant difference between females and males. According to our study, a CS might be an anatomical structure rather than an anatomical variation, as all patients had at least one AC of the CS. It can be inferred that the detection of ACs will be achievable once clinicians are aware of these structures with continuous regular anatomy reworks and with small voxel-sized CBCT devices. Conclusion: This study was conducted to find the features and prevalence of the CS, and it was found that the CS is an anatomical structure rather than an anatomical variation. This argument is in line with the information on the CS in Gray’s Anatomy, 42nd Edition. Impaired healings and complications of the CS can be avoided if clinicians follow the American Academy of Oral and Maxillofacial Radiology guidelines regarding pre-operative implant examination. Otherwise, avertible complications may cause significant impairments in quality of life.
Association between Endodontic Infection, Its Treatment and Systemic Health: A Narrative Review
Authors: Niazi Sadia Ambreen , Bakhsh Abdulaziz
Published: July 2022

The ‘Focal Infection Era in Dentistry’ in the late 19th and early 20th century resulted in widespread implementation of tooth extraction and limited the progress of endodontics. The theory proposed that bacteria and toxins entrapped in dentinal tubules could disseminate systemically to remote body parts, resulting in many types of degenerative systemic diseases. This theory was eventually refuted due to anecdotal evidence. However, lately there has been increased interest in investigating whether endodontic disease could have an impact on general health. There are reviews that have previously been carried out on this subject, but as new data have emerged since then, this review aims to appraise the available literature investigating the dynamic associations between apical periodontitis, endodontic treatment, and systemic health. The available evidence regarding focal infection theory, bacteraemia and inflammatory markers was appraised. The review also collated the available research arguing the associations of apical periodontitis with cardiovascular diseases, diabetes mellitus, adverse pregnancy outcome and autoimmune disorders, along with the effect of statins and immunomodulators on apical periodontitis prevalence and endodontic treatment prognosis. There is emerging evidence that bacteraemia and low-grade systemic inflammation associated with apical periodontitis may negatively impact systemic health, e.g., development of cardiovascular diseases, adverse pregnancy outcomes, and diabetic metabolic dyscontrol. However, there is limited information supporting the effect of diabetes mellitus or autoimmune disorders on the prevalence and prognosis post endodontic treatment. Furthermore, convincing evidence supports that successful root canal treatment has a beneficial impact on systemic health by reducing the inflammatory burden, thereby dismissing the misconceptions of focal infection theory. Although compelling evidence regarding the association between apical periodontitis and systemic health is present, further high-quality research is required to support and establish the benefits of endodontic treatment on systemic health.
Trends in the Incidence and Severity of Injuries Sustained by Riders of Electric Bikes and Powered Scooters: A Retrospective Cross-Sectional Study
Authors: Yahya Bahaa Haj , Demetriou Helena , Zelnik Adi , Cohen Nir , Drescher Michael J. , Chaushu Gavriel , Hamzani Yafit
Published: July 2022

Background and Objectives: The worldwide increase in electric bike (E-bike) and powered scooter (P-scooter) use in recent years has been accompanied by an increase in associated injuries to riders. The aim of this study was to evaluate trends in the incidence and types of E-bikes and P-scooter-related injuries in riders evacuated to a tertiary ED. Materials and Methods: A retrospective cross-sectional design was used. The cohort included 1234 patients referred to the emergency department (ED) of a tertiary medical center in 2014–2020 for injuries sustained while riding an E-bike or P-scooter. Demographic, clinical, and injury data were collected from the medical files, and injury rates were evaluated over time. Results: The results showed that the annual number of ED visits by injured E-bike and P-scooter riders increased steadily over the study period concomitant with an increase in ED referrals for hospitalization, indicating severe injury. The upper and lower extremities were the most frequent anatomic sites of injury in every year of the study, with variations among the different age groups. Conclusions: Our findings suggest a need for safety regulations for riders who operate two-wheel powered vehicles, such as licensing requirements and mandatory protective gear, especially for anatomic sites most at risk.
The Necessity of a Locally Active Antidote in the Clinical Practice of Botulinum Neurotoxin Therapy: Short Communication
Authors: Hefter Harald , Samadzadeh Sara
Published: July 2022

Recently, it was demonstrated that copper complexes and 3,4-diaminopyridine can effectively reduce the activity of the botulinum neurotoxin light chain. The aim of the present study was to indicate that treatment with an antidote may have a major influence, not only on the extremely rare disease of botulism, but also on the much more frequently occurring side effects experienced during BoNT therapy. This was a retrospective chart review of patients who were regularly treated with BoNT for various indications. The percentage of patients with clinical signs of overdosing was determined. In patients with facial dystonia, double vision and ptosis occurred as side effects. In patients with cervical dystonia, neck weakness and dysphagia were observed as the most frequent side effects. In oromandibular and oropharyngeal dystonia, abnormal tongue movements and dysphagia occurred frequently. In writer’s cramp and mild post-stroke hand spasticity, severe paresis of the injected and non-injected finger muscles was observed. Additionally, in the BoNT treatment of pain syndromes (such as tension headaches or migraines), neck weakness may occur. Across all indications for clinical BoNT applications, clinical signs of BoNT overdosing may occur in up to 5% of the BoNT-treated patients. Therefore, the development of an antidote for BoNT overdoses would be very much appreciated and would have a major influence on the management of BoNT therapy.
Roles of Sodium Hydrogen Exchanger (NHE1) and Anion Exchanger (AE2) across Chondrocytes Plasma Membrane during Longitudinal Bone Growth
Authors: Abubakar Adamu Abdul , Ali Ahmed Khalaf , Ibrahim Sahar Mohammed , Handool Kareem Obayes , Khan Mohammad Shuaib , Mustapha Noordin Mohamed , Ibrahim Tengku Azmi Tengku , Kaka Ubedullah , Yusof Loqman Mohamad
Published: July 2022

Mammalian long bone growth occurs through endochondral ossification, majorly regulated by the controlled enlargement of chondrocytes at the growth plate (GP). This study aimed to investigate the roles of Na+/H+ (sodium hydrogen exchanger (NHE1)) and HCO3− (anion exchanger [AE2]) during longitudinal bone growth in mammals. Bones from P10 SpragueDawley rat pups were cultured exvivo in the presence or absence of NHE1 and AE2 inhibitors to determine their effect on long bone growth. Gross morphometry, histomorphometry, and immunohistochemistry were used to assess the bone growth. The results revealed that the culture of the bones in the presence of NHE1 and AE2 inhibitors reduces bone growth significantly (p < 0.05) by approximately 11%. The inhibitor significantly (p < 0.05) reduces bone growth velocity and the length of the hypertrophic chondrocyte zone without any effect on the total GP length. The total GP chondrocyte density was significantly (p < 0.05) reduced, but hypertrophic chondrocyte densities remained constant. NHE1 fluorescence signaling across the GP length was higher than AE2, and their localization was significantly (p < 0.05) inhibited at the hypertrophic chondrocytes zone. The GP lengthening was majorly driven by an increase in the overall GP chondrocyte and hypertrophic chondrocyte densities apart from the regulatory volume phenomenon. This may suggest that NHE1 and AE2 could have a regulatory role in long bone growth.
Computational Studies on Holey TMC6 (TM = Mo and W) Membranes for H2 Purification
Authors: Xie Juan , Ning Cai , Liu Qinqin , Sun Zhongti , Yang Juan , Dong Huilong
Published: July 2022

The purification of hydrogen (H2) has been a vital step in H2 production processes such as steam–methane reforming. By first-principle calculations, we revealed the potential applications of holey TMC6 (TM = Mo and W) membranes in H2 purification. The adsorption and diffusion behaviors of five gas molecules (including H2, N2, CO, CO2, and CH4) were compared on TMC6 membranes with different phases. Though the studied gas molecules show weak physisorption on the TMC6 membranes, the smaller pore size makes the gas molecules much more difficult to permeate into h-TMC6 rather than into s-TMC6. With suitable pore sizes, the s-TMC6 structures not only show an extremely low diffusion barrier (around 0.1 eV) and acceptable permeance capability for the H2 but also exhibit considerably high selectivity for both H2/CH4 and H2/CO2 (>1015), especially under relatively low temperature (150–250 K). Moreover, classical molecular dynamics simulations on the permeation process of a H2, CO2, and CH4 mixture also validated that s-TMC6 could effectively separate H2 from the gas mixture. Hence, the s-MoC6 and s-WC6 are predicted to be qualified H2 purification membranes, especially below room temperature.
In Vivo Evaluation of Permeable and Impermeable Membranes for Guided Bone Regeneration
Authors: Sartoretto Suelen Cristina , Gens Natalia de Freitas , de Brito Resende Rodrigo Figueiredo , Alves Adriana Terezinha Neves Novellino , Cecato Rafael Cury , Uzeda Marcelo José , Granjeiro Jose Mauro , Calasans-Maia Monica Diuana , Calasans-Maia Jose Albuquerque
Published: July 2022

Background: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. Methods: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm2) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). Results: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. Conclusions: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.
Microbial Metabolite 3-Indolepropionic Acid Mediates Immunosuppression
Authors: Guijas Carlos , Horton Lucy E. , Hoang Linh , Domingo-Almenara Xavier , Billings Elizabeth M. , Ware Brian C. , Sullivan Brian , Siuzdak Gary
Published: July 2022

The microbial-derived metabolite, 3-indolepropionic acid (3-IPA), has been intensely studied since its origins were discovered in 2009; however, 3-IPA’s role in immunosuppression has had limited attention. Untargeted metabolomic analyses of T-cell exhaustion and immunosuppression, represented by dysfunctional under-responsive CD8+ T cells, reveal a potential role of 3-IPA in these responses. T-cell exhaustion was examined via infection of two genetically related mouse strains, DBA/1J and DBA/2J, with lymphocytic choriomeningitis virus (LCMV) Clone 13 (Cl13). The different mouse strains produced disparate outcomes driven by their T-cell responses. Infected DBA/2J presented with exhausted T cells and persistent infection, and DBA/1J mice died one week after infection from cytotoxic T lymphocytes (CTLs)-mediated pulmonary failure. Metabolomics revealed over 70 metabolites were altered between the DBA/1J and DBA/2J models over the course of the infection, most of them in mice with a fatal outcome. Cognitive-driven prioritization combined with statistical significance and fold change were used to prioritize the metabolites. 3-IPA, a tryptophan-derived metabolite, was identified as a high-priority candidate for testing. To test its activity 3-IPA was added to the drinking water of the mouse models during LCMV Cl13 infection, with the results showing that 3-IPA allowed the mice to survive longer. This negative immune-modulation effect might be of interest for the modulation of CTL responses in events such as autoimmune diseases, type I diabetes or even COVID-19. Moreover, 3-IPA’s bacterial origin raises the possibility of targeting the microbiome to enhance CTL responses in diseases such as cancer and chronic infection.
An Investigation into the Densification-Affected Deformation and Fracture in Fused Silica under Contact Sliding
Authors: Li Changsheng , Ma Yushan , Sun Lin , Zhang Liangchi , Wu Chuhan , Ding Jianjun , Duan Duanzhi , Wang Xuepeng , Chang Zhandong
Published: July 2022

Subsurface damage of fused silica optics is one of the major factors restricting the performance of optical systems. The densification-affected deformation and fracture in fused silica under a sliding contact are investigated in this study, via three-dimensional finite element analysis (FEA). The finite element models of scratching with 70.3° conical and Berkovich indenters are established. A refined elliptical constitutive model is used to consider the influence of densification. The finite element models are experimentally verified by elastic recovery, and theoretically verified by hardness ratio. Results of densification and plastic deformation distributions indicate that the accuracy of existent sliding stress field models may be improved if the spherical/cylindrical yield region is replaced by an ellipsoid/cylindroid, and the embedding of the yield region is considered. The initiation sequence, and the locations and stages of radial, median, and lateral cracks are discussed by analyzing the predicted sliding stress fields. Median and radial cracks along the sliding direction tend to be the first cracks that emerge in the sliding and unloading stages, respectively. They coalesce to form a big median–radial crack that penetrates through the entire yield region. The fracture behavior of fused silica revealed in this study is essential in the low-damage machining of fused silica optics.
Tire Ground Rubber Biodegradation by a Consortium Isolated from an Aged Tire
Authors: Castañeda Alejo Sarelia M. , Tejada Meza Kevin , Valderrama Valencia María R. , Arenazas Rodríguez Armando J. , Málaga Espinoza Christian J.
Published: July 2022

Rubber is a natural product, the main car tire component. Due to the characteristics acquired by this material after its vulcanization process, its degradation under natural conditions requires very long times, causing several environmental problems. In the present work, the existence of a bacterial consortium isolated from a discarded tire found within the Socabaya River with the ability to degrade shredded tire rubber without any chemical pretreatment is explored. Taking into consideration the complex chemical composition of a rubber tire and the described benefits of the use of pretreatments, the study is developed as a preliminary analysis. The augmentative growth technique was used, and the level of degradation was quantified as a percentage through the analysis of microbial respiration. Schiff’s test and the use of comparative photographs of scanning electron microscopy (SEM) were also used. The consortium using next generation genetic sequencing was analyzed. A 4.94% degradation point was obtained after 20 days of experimentation, and it was found that the consortium was mostly made up with Delftia tsuruhatensis with 69.12% of the total genetic readings of the consortium and the existence of 15% of unidentified microbial strains at the genre level. The role played by the organisms in the degradation process is unknown. However, the positive results in the tests carried out show that the consortium had action on the shredded tire, showing a mineralization process.
Hydrocarbon Cycling in the Tokamachi Mud Volcano (Japan): Insights from Isotopologue and Metataxonomic Analyses
Authors: Gilbert Alexis , Nakagawa Mayuko , Taguchi Koudai , Zhang Naizhong , Nishida Akifumi , Yoshida Naohiro
Published: July 2022

Understanding hydrocarbon cycling in the subsurface is important in various disciplines including climate science, energy resources and astrobiology. Mud volcanoes provide insights into biogeochemical processes occurring in the subsurface. They are usually associated with natural gas reservoirs consisting mainly of methane and other hydrocarbons as well as CO2. Stable isotopes have been used to decipher the sources and sinks of hydrocarbons in the subsurface, although the interpretation can be ambiguous due to the numerous processes involved. Here we report new data for hydrocarbon isotope analysis, including position-specific isotope composition of propane, for samples from the Tokamachi mud volcano area, Japan. The data suggest that C2+ hydrocarbons are being biodegraded, with indirect production of methane (“secondary methanogenesis”). Data from chemical and isotopic composition are discussed with regard to 16S rRNA analysis, which exhibits the presence of hydrogenotrophic and acetoclastic methoanogens. Overall, the combination of isotopologue analysis with 16S rRNA gene data allows refining of our understanding of hydrocarbon cycling in subsurface environments.
Plasmodium falciparum S-Adenosylmethionine Synthetase Is Essential for Parasite Survival through a Complex Interaction Network with Cytoplasmic and Nuclear Proteins
Authors: Musabyimana Jean Pierre , Distler Ute , Sassmannshausen Juliane , Berks Christina , Manti Janice , Bennink Sandra , Blaschke Lea , Burda Paul-Christian , Flammersfeld Ansgar , Tenzer Stefan , Ngwa Che Julius , Pradel Gabriele
Published: July 2022

S-adenosylmethionine synthetase (SAMS) is a key enzyme for the synthesis of the lone methyl donor S-adenosyl methionine (SAM), which is involved in transmethylation reactions and hence required for cellular processes such as DNA, RNA, and histone methylation, but also polyamine biosynthesis and proteostasis. In the human malaria parasite Plasmodium falciparum, PfSAMS is encoded by a single gene and has been suggested to be crucial for malaria pathogenesis and transmission; however, to date, PfSAMS has not been fully characterized. To gain deeper insight into the function of PfSAMS, we generated a conditional gene knockdown (KD) using the glmS ribozyme system. We show that PfSAMS localizes to the cytoplasm and the nucleus of blood-stage parasites. PfSAMS-KD results in reduced histone methylation and leads to impaired intraerythrocytic growth and gametocyte development. To further determine the interaction network of PfSAMS, we performed a proximity-dependent biotin identification analysis. We identified a complex network of 1114 proteins involved in biological processes such as cell cycle control and DNA replication, or transcription, but also in phosphatidylcholine and polyamine biosynthesis and proteasome regulation. Our findings highlight the diverse roles of PfSAMS during intraerythrocytic growth and sexual stage development and emphasize that PfSAMS is a potential drug target.
Anaerobic Digestion of Chicken Manure in the Presence of Magnetite, Granular Activated Carbon, and Biochar: Operation of Anaerobic Reactors and Microbial Community Structure
Authors: Ziganshina Elvira E. , Ziganshin Ayrat M.
Published: July 2022

The influence of magnetite nanoparticles, granular activated carbon (GAC), and biochar, as well as their combinations on the anaerobic digestion of chicken manure and the structure of microbial communities was studied. The addition of magnetite, GAC, and biochar increased the rate of methane production and the total methane yield. It has been observed that these additives stimulated anaerobic microorganisms to reduce the concentration of accumulated volatile organic acids. Various bacterial species within the classes Bacteroidia and Clostridia were found at higher levels in the anaerobic reactors but in different proportions depending on the experiment. Members of the genera Methanosarcina, Methanobacterium, Methanothrix, and Methanoculleus were mainly detected within the archaeal communities in the anaerobic reactors. Compared to the 16S rRNA gene-based study, the mcrA gene approach allowed a higher level of Methanosarcina in the system with GAC + magnetite to be detected. Based on our findings, the combined use of granular activated carbon and magnetite at appropriate dosages will improve biomethane production.
Combined Action of Antibiotics and Bacteriocins against Vancomycin-Resistant Enterococci
Authors: Bucheli Jorge Enrique Vazquez , Fugaban Joanna Ivy Irorita , Holzapfel Wilhelm Heinrich , Todorov Svetoslav Dimitrov
Published: July 2022

Antibiotics have been one of the most important discoveries in the area of applied medical microbiology; however, as a result of various factors, we are currently facing a dramatic and relatively dangerous increase in the number of cases of antibiotic resistance, and the need for new types of antimicrobials continues to grow. New approaches are needed to combat antibiotic-resistant pathogens. Bacteriocins, as part of the group of antimicrobial peptides, can be considered as alternatives and/or complements to known antibiotics. Their narrow spectra of activity can be explored for the control of various pathogens, such as vancomycin-resistant enterococci (VRE), as single therapies or in combination with known antibiotics. In the present study, we isolated bacteriocins from different lactic acid bacteria (LAB) strains, including Enterococcus and Pediococcus, and explored the possible synergistic inhibition of growth by bacteriocins and vancomycin. It was observed in the growth dynamics with previously selected VRE strains that the bacteriocins had a high specificity and a promising inhibitory effect against the VRE strains, and these results were validated by a propidium iodide viability test using flow cytometry. The data obtained indicate that the selected bacteriocins can be used to control VRE in the food industry or even as an alternative treatment to combat infections with antibiotic-resistant bacteria.
Screening and Characterization of Multidrug-Resistant Enterobacterales among Hospitalized Patients in the African Archipelago of Cape Verde
Authors: Freire Samanta , Grilo Teresa , Teixeira Maria Luísa , Fernandes Euclides , Poirel Laurent , Aires-de-Sousa Marta
Published: July 2022

This study aimed to investigate, for the first time, the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales in Cape Verde. A total of 98 inpatients hospitalized at Hospital Universitário Agostinho Neto were screened for rectal colonization. All ESBL- and carbapenemase-producing isolates were tested for antimicrobial susceptibility and characterized by multilocus sequence typing. Mating-out assay followed by PCR-based replicon typing were performed to characterize the plasmids harboring carbapenemase encoding genes. A large proportion of patients carried ESBL- or carbapenemase-producing Enterobacterales (56% and 6%, respectively). Among 93 ESBL-producing isolates, there were mainly Klebsiella pneumoniae (58%) and Escherichia coli (37%). Five different ESBLs were detected, with CTX-M-15 being highly predominant (92%). Six carbapenemase-producing isolates (five E. coli and one K. pneumoniae) were recovered, and all of the OXA-48-like type (four OXA-181, one OXA-48, and one OXA-244). The blaOXA-48 gene was located on an IncFI-type plasmid, the blaOXA-181 gene on IncFI or IncX3 plasmids, and the blaOXA-244 gene was found to be chromosomally located. The five carbapenemase-producing E. coli isolates belonged to five distinct sequence types. This study overall showed a very high prevalence of ESBL-producing Enterobacterales, as well as the emergence of carbapenemase producers in this hospital.
Diagnosis and Prevalence of Chagas Disease in an Indigenous Population of Colombia
Authors: Kann Simone , Dib Juan Carlos , Aristizabal Andrés , Mendoza Gustavo Concha , Lacouture Hugo Dario Soto , Hartmann Maria , Frickmann Hagen , Kreienbrock Lothar
Published: July 2022

Chagas disease (CD) is one of the leading neglected tropical diseases. In the Americas, CD is endemic in about 21 countries, but only less than 1% of the patients have access to medical treatment. Indigenous populations are particularly affected because they live in socio-economic and climate conditions that favor CD infections. In this study, diagnostic strategies and regional prevalence of the Chagas disease were assessed. In nine villages of the indigenous tribe Wiwa, 1134 persons were tested with a Chagas-antibody-specific rapid test (RT), two different Chagas-antibody-specific ELISAs and a Chagas-specific real-time polymerase chain reaction. The overall prevalence of CD in the villages was 35.4%, with a variation from 24.9% to 52.8% for the different communities. Rapid tests and ELISAs showed the same results in all cases. The proportion of replication-active infections, defined by positive PCR results, was 8.7%. In conclusion, the assessed indigenous population in Colombia was shown to be severely affected by CD. For a serological diagnosis, one rapid test was shown to be sufficient. Replacements of ELISAs by RT would decrease costs, increase feasibility and would relevantly help detect positive patients, especially if combined with the applied real-time PCR protocol. Real-time PCR can be considered for the detection of acute cases, outbreaks, chronic cases with re-infection/activation, as well as for therapy management and control.
Know What You Don’t Know: Assessment of Overlooked Microplastic Particles in FTIR Images
Authors: Weisser Jana , Pohl Teresa , Ivleva Natalia P. , Hofmann Thomas F. , Glas Karl
Published: July 2022

Assessing data analysis routines (DARs) for microplastics (MP) identification in Fourier-transform infrared (FTIR) images left the question ‘Do we overlook any MP particles in our sample?’ widely unanswered. Here, a reference image of microplastics, RefIMP, is presented to answer this question. RefIMP contains over 1200 MP and non-MP particles that serve as a ground truth that a DAR’s result can be compared to. Together with our MatLab® script for MP validation, MPVal, DARs can be evaluated on a particle level instead of isolated spectra. This prevents over-optimistic performance expectations, as testing of three hypotheses illustrates: (I) excessive background masking can cause overlooking of particles, (II) random decision forest models benefit from high-diversity training data, (III) among the model hyperparameters, the classification threshold influences the performance most. A minimum of 7.99% overlooked particles was achieved, most of which were polyethylene and varnish-like. Cellulose was the class most susceptible to over-segmentation. Most false assignments were attributed to confusion of polylactic acid for polymethyl methacrylate and of polypropylene for polyethylene. Moreover, a set of over 9000 transmission FTIR spectra is provided with this work, that can be used to set up DARs or as standard test set.
Natural Radioactivity and Radiological Hazard Effects from Granite Rocks in the Gabal Qash Amir Area, South Eastern Desert, Egypt
Authors: Emad Bahaa M. , Sayyed M. I. , Somaily Hamoud H. , Hanfi Mohamed Y.
Published: July 2022

The existence of radioactivity linked to the heavy-bearing minerals in building materials—such as granite—has increased attention to the extraction procedure. Granite rocks play an essential economic role in various areas of Egypt. Thus, this study intended to detect the 238U, 232Th, and 40K activity concentrations in the examined granite samples and to determine the corresponding radiological risks associated with the granite. The studied rocks were collected in the Gabal Qash Amir area (south Eastern Desert, Egypt). The obtained results of the activity concentrations for 238U (193 ± 268) Bq/kg, 232Th (63 ± 29) Bq/kg, and 40K (1034 ± 382) Bq/kg indicated that there were moderate concentrations in the investigated samples, which were greater than the worldwide average. The radioactivity levels in the studied granite samples are due to the secondary alteration of radioactive-bearing minerals associated with cracks of granites (secondary minerals in muscovite granites are wolframite, uraninite, uranophane, beta-uranophane, autunite, xenotime, columbite, zircon, and monazite). The radiological risk assessment for the public from the radionuclides that were associated with the studied granite samples was predicted via estimating the radiological hazard factors, such as the radium equivalent content (362 Bq kg−1), compared with the recommended limit. The dosing rate Dair in the air (169.2 nGy/h), the annual effective dose both outdoors (AEDout ~ 0.21 ± 0.17 mSv) and indoors (AEDin ~ 0.83 ± 0.67 mSv), the annual gonadal dose equivalent (AGDE ~ 1.18 ± 0.92 mSv), as well as the external (Hex) and internal (Hin) hazard indices (>1), and another factor were associated with excess lifetime cancer risk. According to the statistical investigation, the studied granites were inappropriate for use in construction and infrastructure fields. They may induce health problems due to the radioactivity levels, which exceed the recommended limits.
The Effect of Mn Substitution on Natural Sphalerites by Means of Raman Spectroscopy: A Case Study of the Săcărâmb Au–Ag–Te Ore Deposit, Apuseni Mountains, Romania
Authors: Dincă George , Apopei Andrei , Szabo Robert , Maftei Andreea
Published: July 2022

Natural samples of sphalerites containing Mn in the range 0 ≤ x ≤ 0.25 apfu from the Săcărâmb Au–Ag–Te ore deposit, found in the Apuseni Mountains, Romania, were investigated using Raman spectroscopy to determine its capability to provide estimates of Mn content. Raman data for the natural Mn-rich sphalerite have not been published so far, with the largest concentration of Mn in sphalerites being from Romanian territory (i.e., 14.1 wt.%). The results are in good agreement with SEM-EDS data. In this study, three genetic types of sphalerites were identified: from ferroan Zn0.87Fe0.16∑=1.03S0.97 to manganoferroan Zn0.77Mn0.14Fe0.06∑=0.97S1.03, as well as mangan-rich Zn0.8Mn0.25∑=1.05S0.95 compositions. Sphalerites with a high content of Mn (up to 14.1 wt.%) were strongly connected to the presence of alabandite in the mineralized assemblages. The formation of several types of sphalerites in the Săcărâmb Au–Ag–Te ore deposit was caused by the succession of different types of hydrothermal fluids and the interaction between the fluids and the host materials (host rocks and earlier mineralized stages).
Crystal Chemistry, Isomorphism, and Thermal Conversions of Extra-Framework Components in Sodalite-Group Minerals
Authors: Chukanov Nikita , Shendrik Roman , Vigasina Marina , Pekov Igor , Sapozhnikov Anatoly , Shcherbakov Vasily , Varlamov Dmitry
Published: July 2022

Isomorphic substitutions of extra-framework components in sodalite-group aluminosilicate minerals and their thermal conversions have been investigated using infrared, Raman, electron spin resonance (ESR), as well as ultraviolet, visible and near infrared (UV–Vis–near IR) absorption spectroscopy methods and involving chemical and X-ray diffraction data. Sodalite-related minerals from gem lazurite deposits (haüyne, lazurite, and slyudyankaite) are characterized by wide variations in S-bearing extra-framework components including SO42− and various polysulfide groups (S2●−, S3●−, S4●− radical anions, and S4 and S6 neutral molecules) as well as the presence of CO2 molecules. Heating at 700 °C under reducing conditions results in the transformation of initial S-bearing groups SO42− and S3●− to a mixture of S2−, HS−, S2●−, and S4●− and transformation of CO2 to a mixture of CO32− and C2O42− or HC2O4− anionic groups. Further heating at 800 °C in air results in the decomposition of carbonate and oxalate groups, restoration of the SO42− and S3●− groups, and a sharp transformation of the framework. The HS− anion is stable only under reducing conditions, whereas the S3●− radical anion is the most stable polysulfide group. The HS−-dominant sodalite-group mineral sapozhnikovite forms a wide solid-solution series with sodalite. The conditions required for the formation of HS−- and CO20-bearing sodalite-group minerals are discussed.