Production Test Research Articles

Balancing Activity and Selectivity in Two-electron Oxygen Reduction through First Coordination Shell Engineering in Cobalt Single Atom Catalysts.

The electrochemical two-electron oxygen reduction reaction (2e- ORR) offers a potentially cost-effective and eco-friendly route for the production of hydrogen peroxide (H2O2). However, the competing 4e- ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective H2O2 production under low voltage conditions remains challenging. Herein, guided by first-principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co-N-C catalysts with Co-NxO4-x sites), specifically the replacement of Co-N bonds with Co-O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards H2O2 (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N-doped carbon-supported catalysts with Co-NxO4-x active sites, we were able to validate the DFT findings and explore the trade-off between catalytic activity and selectivity for 2e- ORR. A catalyst with trans-Co-N2O2 sites exhibited excellent catalytic activity and H2O2 selectivity, affording a H2O2 production rate of 12.86 [[EQUATION]]and an half-cell energy-efficiency of 0.07 [[EQUATION]] during a 100-h H2O2 production test in a flow-cell.

Balancing Activity and Selectivity in Two‐electron Oxygen Reduction through First Coordination Shell Engineering in Cobalt Single Atom Catalysts

The electrochemical two‐electron oxygen reduction reaction (2e‐ ORR) offers a potentially cost‐effective and eco‐friendly route for the production of hydrogen peroxide (H2O2). However, the competing 4e‐ ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective H2O2 production under low voltage conditions remains challenging. Herein, guided by first‐principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co‐N‐C catalysts with Co‐NxO4‐x sites), specifically the replacement of Co‐N bonds with Co‐O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards H2O2 (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N‐doped carbon‐supported catalysts with Co‐NxO4‐x active sites, we were able to validate the DFT findings and explore the trade‐off between catalytic activity and selectivity for 2e‐ ORR. A catalyst with trans‐Co‐N2O2 sites exhibited excellent catalytic activity and H2O2 selectivity, affording a H2O2 production rate of 12.86 [[EQUATION]]and an half‐cell energy‐efficiency of 0.07 [[EQUATION]] during a 100‐h H2O2 production test in a flow‐cell.

Strategies for creation of data reserve and stress testing of medical AI products

With the fast development of artificial intelligence (AI) and its applications in medicine, it is often said that the time for intelligent medicine is arriving, if not already have arrived....

Testing of retail cheese, butter, ice cream and other dairy products for highly pathogenic avian influenza in the US

Testing of retail cheese, butter, ice cream and other dairy products for highly pathogenic avian influenza in the US

Plant-based Meat Analogs: Perspectives on Their Meatiness, Nutritional Profile, Environmental Sustainability, Acceptance and Challenges.

Plant-based meat analogs (PBMAs) have been the subject of interest over the past few years due to consumers' demand for environmentally friendly, healthful, and non-animal-based foods. A better comprehension of the composition, structure, texture, nutrition, and sustainability of these PBMAs is necessary. This review articulates the protein sources and composition of PBMAs and their "meatiness" with respect to texture, structure, and flavor enhancement. The components used in the analogs, such as unsaturated fats, fibers, vitamins, minerals, carbohydrates, and plant-based oils enriching their nutritional profile, are described. The study identifies the environmental and sustainability impact of PBMAs, as crucial to the survival and maintenance of biodiversity. More studies are warranted to scope and underscore the significance of the analogs and comprehend the texture or structure-function relationships. Further product development and testing thereof may ultimately result in quality meat analogs that respect meat taste, health and acceptance of consumers, environmental sustainability, animal welfare, and current challenges.

Science Learning Media for Elementary School Students

The use of media in learning will provide a learning experience for students because it can involve more senses and give them the freedom to interpret. This study aims to: develop android-based science learning media for elementary school students, obtain android-based science learning media suitable for elementary school students, and determine the response of elementary school students to android-based science learning media. This research is a Research and Development (R&D) study. The development procedure consists of six steps, namely: analysis of potential problems, data collection, product design, design validation, design revision, and product testing. The assessment instrument used is a questionnaire sheet to test the quality of Android-based science learning media products. The assessment of the quality of Android-based science learning media products is conducted by reviewers, peer reviewers, elementary school (SD/MI) teachers, and the response of sixth-grade students. The results of this development research are as follows: 1) Android-based science learning media products on the topic of living organism reproduction for sixth-grade students of SD/MI have been developed, 2) the Android-based science learning media for sixth-grade students of SD/MI on the topic of living organism reproduction has been assessed by reviewers, peer reviewers, and SD/MI teachers with a rating of "Very Good" (SB) with a score of 631 and a percentage rating of 86.85%, and 3) the response of sixth grade students of SD/MI to the Android-based science learning media falls within the "Agree and Strongly Agree" interval, resulting in a score of 635 with a rating percentage of 88.23%.

Facilitating Oriented Electron Transfer from Cu to Mo2C MXene for Weakened Mo─H Bond Toward Enhanced Photocatalytic H2 Generation.

Mo2C MXene (Mo2CTx) is recognized as an excellent cocatalyst due to unique physicochemical properties and platinum-like d-band of Mo active sites. However, Mo sites of Mo2CTx with high-density empty d-orbitals exhibit strong Mo─Hads bonds during photocatalytic hydrogen evolution, leading to easy adsorption of hydrogen ions from solution and unfavorable desorption of H2 from Mo sites. To weaken the Mo─Hads bond, a strategy of oriented electron transfer from Cu to Mo2CTx to increase the antibonding orbital occupancy of Mo─Hads hybrid orbitals is implemented by introducing Cu into Mo2CTx interlayers to form Cu-Mo2CTx. The Cu-Mo2CTx is synthesized from Mo2Ga2C and CuCl2 via a one-step molten salt method and combined with TiO2 to form Cu-Mo2CTx/TiO2 photocatalyst through an ultrasound-assisted approach. Hydrogen production tests reveal that an exceptional performance of Cu-Mo2CTx/TiO2 (6446µmol h-1 g-1, AQE=18.3%) is 8.4 fold higher than that of Mo2CF2/TiO2 (Mo2CF2 by the conventional etchant NH4F+HCl). Density functional theory (DFT) calculations and characterization results corroborate that the oriented electron transfer from Cu to Mo2CTx increases the Mo─Hads antibonding occupancy in Cu-Mo2CTx, thereby weakening Mo─Hads bonds and accelerating the hydrogen evolution rate of TiO2. This research offers valuable insights into optimizing H-adsorption capabilities at active sites on MXene materials.

Strategy to measure tau g−2 via photon fusion in LHC proton collisions

Measuring the tau-lepton (τ) anomalous magnetic moment aτ=(gτ−2)/2 in photon fusion production (γγ→ττ) tests foundational Standard Model principles. However, γγ→ττ eludes observation in LHC proton collisions (pp) despite enhanced new physics sensitivity from higher-mass reach than existing probes. We propose a strategy to measure pp→p(γγ→ττ)p by introducing the overlooked electron-muon signature with vertex isolation for signal extraction. Applying the effective field theory of dipole moments, we estimate 95% confidence level sensitivity of −0.0092<aτ<0.011 assuming 300 fb−1 luminosity and 5% systematics. This fourfold improvement beyond existing constraints opens a crucial path to unveiling new physics imprinted in tau-lepton dipoles. Published by the American Physical Society 2024

Development of PhET-assisted simulation e-worksheet using flipped laboratory approach for science communication skills

Communication skills are one of the 21st century skills. Specific communication in biology learning includes science communication. The purpose of the study was to analyze the improvement of science communication skills using E-Worksheet assisted by PhET on nervous system material. This research and development consist of three stages: the preliminary study stage, the product development stage and the product testing stage. Static-Group Pretest-Posttest research design. This study involved 35 students in the experimental class and 35 students in the control class selected using Purposive Sampling. The research instrument consisted of a validation questionnaire and limited description with indicators of science communication. Data analysis informs that e-worksheet is very feasible with an average score of 83.83%. The improvement of science communication skills on the nervous system material in the classroom using e-worksheet assisted by PhET simulation with an overall N-Gain value of 0.56 with moderate criteria. E-Worksheet assisted by PhET simulation helps the learning process. The guide to using E-Worksheet assisted by PhET simulation should be clearer and more detailed and provide training for teachers to be more familiar with electronics.

HANNES: A Modular Neurointerventional Training Model

Abstract This work introduces version 2.0 of the Hamburg ANatomical NEurointerventional Simulator (HANNES): a novel modular neurointerventional simulator designed to provide a realistic platform for simulating various neurovascular pathologies and their endovascular therapies. Collaboratively developed by physicians and engineers, the neurointerventional simulator is designed with a modular product architecture combining standardized and variant modules to represent different training scenarios. The additively manufactured patient-based and patient-specific blood vessel tree consists of up to 13 individual components, including standardized features and interfaces for ease of connection. Patient-specific vessel models derived from medical imaging data allow customization and complexity adjustment. HANNES supports diverse neurointerventional training scenarios, including various modalities of aneurysm embolization, internal carotid artery (ICA)-stenosis, and thrombotic vessel occlusions, which can be treated through a transradial or transfemoral approach. The use and benefits of the model were evaluated with a group of trainees, who provided positive feedback, confirming the model's practicality and effectiveness in enhancing neurointerventional technical skills. In conclusion, HANNES represents a significant advancement in neurointerventional training, addressing the limitations of traditional training methods by simulating diverse disease patterns, enhancing medical staff's skills, and facilitating product testing.

Comparison of free-comment online product reviews and central location product testing for sensory product characterisation: A case study with coffee consumers

Data from online product reviews offers a novel avenue for the sensory characterisation of food. But, little research has investigated the quality of sensory information in the online reviews. The aim of this research was to investigate consumer online reviews as sources of sensory attributes of food products (starting with a minimum of 1000 online reviews per product), and to assess how the resulting sensory product profiles compare to profiles obtained in a central location test with 105 consumers using rate-all-that-apply (RATA) questions. A case study was conducted with five unflavoured coffee samples. A semi-automated approach, combining natural language processing and sensory science expertise was used to clean online review data, develop a sensory lexicon, and analyse the frequency of attributes used by consumers. It was possible to develop online review-based sensory product profiles and discriminate the five samples on this basis. Consumers used a small set of broad, mostly intensity related sensory terms (e.g. ‘Bold/rich’, ‘Strong/intense’, ‘Smooth’, ‘Weak/bland’) more frequently than descriptive terms. Canonical analysis showed high agreement between new method and RATA for product discrimination and between two group of descriptors. The first group (including ‘Coffee Flavor,’ ‘Rich in Flavor’, and ‘Smell of Coffee’) is associated with the intensity of flavour of coffee, while the second group describes characteristic flavour of coffee (including ‘Bold’, ‘Dark’ ‘Body’). Furthermore, care should be taken when implementing these findings in food categories with lower levels of consumer engagement, where consumer comments relating to sensory properties in online reviews may be less frequent.

Enhanced hydrolysis of MgH₂ by transition metal oxides and NaH: Performance, mechanisms, and optimization

MgH₂ is recognized as a promising material for hydrogen production due to its high hydrogen density, abundant availability, and non-polluting hydrolysis by-products, making it a viable hydrogen source for fuel cells. This study, for the first time, investigates the hydrogen production performance of the MgH₂-MOx-NaH (M = Ti, Zr, Mo, Fe, V, Bi) system, which exhibits remarkable hydrolysis properties in aqueous solutions. A series of MgH₂-MOx-NaH composite powders were synthesized via mechanical ball milling. The results revealed that V₂O₅-NaH and Bi₂O₃-NaH significantly enhanced the hydrolysis performance of MgH₂ for hydrogen production. Specifically, Bi₂O₃-NaH and V₂O₅-NaH effectively refined MgH₂ particles and mitigated agglomeration during the milling process. Hydrolysis tests demonstrated that the conversion rate and the hydrogen generation rate (mHGR) of composites initially increased with ball milling time and then decreased. The maximum hydrolysis hydrogen production yield and conversion rate for MgH₂-Bi₂O₃-NaH and MgH₂-V₂O₅-NaH composites occurred at a ball milling duration of 10 hours, and reached up to 1354.1 mL g⁻¹ (88.5 %) and 1273.5 mL g⁻¹ (81.8 %), respectively, within 8 minutes. Kinetic tests of hydrolysis hydrogen production showed that the reaction rate and hydrogen conversion increased with elevated hydrolysis temperatures. The activation energies for the hydrolysis of MgH₂-MOx-NaH (M = Ti, Zr, Mo, Fe, V, Bi) were calculated from the hydrolysis-hydrogen production curves using the Arrhenius formula, yielding values of 41.32, 37.66, 36.40, 34.60, 30.80, and 27.17 kJ mol⁻¹, respectively. The lower activation energies for hydrolysis indicate improved reaction kinetics, suggesting that the incorporation of transition metal oxides and sodium hydride effectively enhances both the hydrolytic conversion and reaction rate of MgH₂.

The macrostructure of narratives produced by children acquiring Finnish Sign Language.

This article investigates the narrative skills of children acquiring Finnish Sign Language (FinSL). Producing a narrative requires vocabulary, the ability to form sentences, and cognitive skills to construct actions in a logical order for the recipient to understand the story. Research has shown that narrative skills are an excellent way of observing a child's language skills, for they reflect both grammatical language skills and the ability to use the language in situationally appropriate ways. This study was conducted using the FinSL Narrative Skills Production Test assessment to observe how narrative skills develop in children between the ages of 4 and 11 who acquire FinSL in their natural language environments. The results show that the narrative skills of children acquiring FinSL develop following the same guidelines found in other signed and spoken languages. Narrative structure and content increase with age.

Emergence of hypervirulent and carbapenem-resistant Klebsiella pneumoniae from 2014 - 2021 in Central and Eastern China: a molecular, biological, and epidemiological study

BackgroundIn recent years, the hypervirulent and carbapenem-resistant Klebsiella pneumoniae has been increasingly reported worldwide. The objective of this study was to compare the antibiotic resistance and virulence profiles of carbapenem-resistant hypervirulent K.pneumoniae (CR-hvKP) and hypervirulent carbapenem-resistant K.pneumoniae (hv-CRKP) and identify the prevailing strain in clinical settings.MethodsIn this study, hv-CRKP or CR-hvKP were identified based on the results of whole-genome analysis (WGS), multilocus sequence typing (MLST) and the antimicrobial susceptibility testing. We then compared antibiotic resistance and virulence profiles between CR-hvKP and hv-CRKP through the antimicrobial susceptibility testing and a series of virulence experiments including biofilm formation ability detection method, the resistance test against human serum, siderophore production test, neutrophil phagocytosis assay and Galleria mellonella infection model. Additionally, pathway enrichment analysis was conducted to assess the effect of SNPs on the phenotype.ResultsIn this study, we categorized 17.4% of hypervirulent and carbapenem-resistant K. pneumoniae strains as CR-hvKP and 82.6% as hv-CRKP. Among them, 84.2% (16/19) of CR-hvKP strains harboring carbapenemase genes exhibited lower imipenem and meropenem MIC values compared to hv-CRKP strains. The virulence potential of hv-CRKP and CR-hvKP was confirmed by using virulence experiments in vitro and in vivo, showing that virulence of the CR-hvKP strains was comparable to that of hv-CRKP strains. Notably, the 90 hv-CRKP strains were classified into 3 different ST types and 8 capsule types, each showing varying degrees of resistance and virulence. We observed that subclonal replacement was within the predominant hv-CRKP clone, with the ST11-KL64 strain, characterized by high-level resistance and virulence emerging as the currently prevailing subclone, replacing ST11-KL47. KEGG enrichment analysis showed that pathways associated with the citrate cycle (TCA cycle), glycolysis/gluconeogenesis, glutathione metabolism, two-component regulatory system, and folate metabolism were significantly enriched among the group expressing different levels of capsular polysaccharides.ConclusionsThe hv-CRKP strains exhibited a greater survival advantage in the hospital environment than CR-hvKP strains. Notably, the ST11-KL64 hv-CRKP strain which displayed a high level of resistance and hypervirulence, warrants the most clinical vigilance.Clinical trial numberNot applicable.

CALCULATION OF TYPE A UNCERTAINTY USING IN-LABORATORY REPEATABILITY FOR DETERMINATION OF WATER CONTEN IN DIESEL

Understanding and managing measurement uncertainty in petroleum testing laboratories is critical to ensuring the accuracy and reliability of test results. Measurement uncertainty is an indicator of the reliability or validity of a measurement result. Here we explore factors contributing to measurement uncertainty, methods for calculating it, and strategies for minimizing it in the context of petroleum product testing. Measurement uncertainty refers to the doubt that exists about the result of any measurement. For every measurement - even with the most advanced equipment - there is always an error, and no measurement can be considered absolutely accurate. In laboratory settings, especially in the analysis of petroleum products, quantification of this uncertainty is essential to meet international standards and ensure the quality and comparability of results. Keywords: uncertainty, quality control, repeatability, standard deviation, in-laboratory repeatability.

A headspace GC-MS method to quantify nitrosamine impurities and precursors in drug products: Method validation and product testing.

Pharmaceutical manufacturers are working to mitigate the formation of nitrosamine impurities in drug products. The work herein describes the development and validation of a headspace GC-MS method according to ICH Q2(R1) guidelines for the detection and quantification of NDMA, NDEA, NDIPA, and NEIPA in drug products. The analytical procedure was further modified to include detection and quantitation of DMF due to the potential decomposition pathway of DMF to form dimethylamine, a known precursor for NDMA formation. The NDMA impurity was detected in the "sartan" class of drug products between 0.1 and 113 ppm. The validated analytical procedure was applied in an investigation of approaches to mitigate nitrosamine formation in metformin drug products. The developed analytical procedures provide another tool for pharmaceutical manufacturers to evaluate drug products for nitrosamine impurities.

The contribution of vocabulary breadth and depth to narrative writing ability: A partial least squares structural equation modelling approach

Despite the well-established role of lexis in proficiency in the four skills, a great deal of research has focused on the importance of vocabulary breadth and depth in reading. Therefore, the neglect of productive skills has motivated recent calls to inspect the impact of lexical dimensions on writing ability. Using Partial Least Squares Structural Equation Modelling (PLS SEM), this study examines the contributions of vocabulary breadth and depth aspects to EFL learners’ narrative writing ability. For this purpose, the researchers administered the Updated Vocabulary Levels Test (the UVLT), the Productive Vocabulary Levels Test (the PVLT), the Word Associates Test (the WAT), and a narrative writing task to 77 EFL undergraduate students. The participants’ scripts were scored, following IELTS analytical band descriptors. Results of the PLS SEM disclosed that vocabulary size and depth explained around 45% of the variance in the writing scores of the subjects. They also revealed that, among the variables examined, receptive vocabulary size was the only statistically significant factor that contributed the most to writing ability. The implications for writing assessment and instruction are discussed.

A multimodal in vitro approach to assess the safety of oral care products using 2D and 3D cellular models.

Periodontitis, affecting approximately 3.9 billion individuals globally, significantly impacts quality of life and has raised interest in its potential systemic effects. Sodium perborate, a common component in oral care products for biofilm control, is widely used, though concerns about its safety persist. This study aimed to evaluate the in vitro toxicity of six commercial oral care products and varying concentrations of sodium perborate, utilizing human gingival fibroblasts (HGF) and keratinocytes (HaCat) as cell models. Experiments were performed in both 2D monolayer and 3D cultures using MTT and electrical impedance assays, adhering to the manufacturer's recommended exposure time of 30-60s for product testing. For the reconstructed epidermis model, a prolonged exposure time of 42min was applied, following the Organization for Economic Cooperation and Development (OECD) Test Guideline 439. Results indicated that all products and sodium perborate at 1mg/mL were cytotoxic in monolayer cultures. However, at concentrations relevant to commercial formulations (0.06mg/mL sodium perborate), no significant toxicity was observed. In contrast, the 3D culture models, including spheroids and reconstructed epidermis, exhibited minimal to no cytotoxic effects for the commercial products, with sodium perborate showing no significant toxicity below 0.1mg/mL. The reconstructed epidermis model, used as surrogate for oral mucosa, further confirmed that the products were non-irritating, in compliance with OECD TG 439 standards. This study highlights the importance of considering exposure time, dosage, and cellular model when assessing the safety of oral care products. While 2D models are useful for preliminary screenings, 3D models provide a more physiologically relevant assessment, emphasizing the need for robust testing protocols to ensure product safety.

Cell-Free Screening, Production and Animal Testing of a STI-Related Chlamydial Major Outer Membrane Protein Supported in Nanolipoproteins.

Vaccine development against Chlamydia, a prevalent sexually transmitted infection (STI), is imperative due to its global public health impact. However, significant challenges arise in the production of effective subunit vaccines based on recombinant protein antigens, particularly with membrane proteins like the Major Outer Membrane Protein (MOMP). Cell-free protein synthesis (CFPS) technology is an attractive approach to address these challenges as a method of high-throughput membrane protein and protein complex production coupled with nanolipoprotein particles (NLPs). NLPs provide a supporting scaffold while allowing easy adjuvant addition during formulation. Over the last decade, we have been working toward the production and characterization of MOMP-NLP complexes for vaccine testing. The work presented here highlights the expression and biophysical analyses, including transmission electron microscopy (TEM) and dynamic light scattering (DLS), which confirm the formation and functionality of MOMP-NLP complexes for use in animal studies. Moreover, immunization studies in preclinical models compare the past and present protective efficacy of MOMP-NLP formulations, particularly when co-adjuvanted with CpG and FSL1. Ex vivo assessments further highlight the immunomodulatory effects of MOMP-NLP vaccinations, emphasizing their potential to elicit robust immune responses. However, further research is warranted to optimize vaccine formulations further, validate efficacy against Chlamydia trachomatis, and better understand the underlying mechanisms of immune response.

СИНХРОНИЗАЦИЯ ПОДАЧИ СЕМЯН И РАБОЧЕЙ ЖИДКОСТИ В КАМЕРУ СМЕШИВАНИЯ ПРОТРАВЛИВАТЕЛЯ

The results of production tests of the PS-20K-4 seed dresser with a modified electrical control circuit in order to synchronize the supply of seeds and working fluid to the mixing chamber of the treater when it is put into operation are presented. At each start-up of the dressers, the supply of seeds to the chamber is ahead of the supply of working fluid to it due to the inertia of the working bodies of the hydraulic system, especially this is manifested on dressing machines equipped with centrifugal pumps for supplying working fluid (PS-20K-4, PS-22, etc.). To ensure the synchronization of the supply of seeds and working fluid to the mixing chamber, a device is proposed, the main part of which is the PVI-11 time delay relay for switching on the seed disc drive. Before starting the dresser, the time of movement of the liquid from the pump to the sprayer is determined. For the time obtained in this way, a delay is set on the PVI-11 attachment. Production tests have shown the advantage of the treater with changes made to the electrical control circuit. With the factory control scheme of the treater, the total weight of untreated seeds and seeds with reduced completeness of treatment, which are defective, increases with the increase in the installed capacity of the unit from 5 to 20 t/h, respectively from 26.4 to 48 kg at the beginning of each machine start-up. With the established synchronization of the supply of seeds and working fluid to the mixing chamber when starting the dressing machine, there were no defective seeds. Operational, technological, technical and economic evaluations of the unit showed that the shift time utilization factor was τ_c = 0.83, Shift productivity increased by 25 % due to a reduction in the time for additional treatment of untreated and insufficiently treated seeds. The indicators of technical and operational reliability were Ktn = 0.98 and Ken = 0.94, respectively. Reduced costs by 35%, reducing labor costs by 25%. The annual economic effect with 140 hours of operating amounted to 29915.6 thousand rubles.