The structure and magnetic properties of composite powders prepared by ball milling a mixture of Fe2O3 ‧ (0.4-1.0)Fe were investigated. Hysteresis loops and differential scanning calorimetry (DSC) curves are used to characterize the materials and to examine the effect of the solid state reaction induced by ball milling. The results showed that a solid state reaction in Fe2O3 ‧ (0.4-1.0)Fe clearly proceeds after only 1 h of ball milling. The system is characterized by a positive reaction heat of +2.23 kcal/mole. The diffraction lines related to Fe2O3 and Fe disappeared after 1 h of ball milling and, instead, diffraction lines of the intermediate phase of Fe3O4 plus FeO formed. The magnetization and coercivity of the Fe2O3 ‧ 0.8Fe powders were changed by the solid state reaction process of Fe2O3 by Fe during ball milling. The coercivity of the Fe2O3 ‧ 0.8Fe powders increased with increasing milling time and reached a maximum value of 340 Oe after 5 h of ball milling. This indicates the grain size of Fe3O4 was clearly reduced during ball milling. The magnetic properties of the annealed powders depend on the amount of magnetic Fe and Fe3O4 phases.
The semiconductor and display industries require the development of plasma resistant materials for use in high density plasma etching process equipment. Yttria (Y2O3) is a ceramic material mainly used to ensure good plasma resistance properties, which requires a dense microstructure. In commercial production, a sintering process is applied to reduce the sintering temperature of Y2O3. In this study, the effect of the addition of glass frit to the sintered specimen was examined when manufacturing yttria sintered specimens for semiconductor process equipment parts. The Y2O3 specimen was shaped into a Ø50 mm size and then sintered at 1,600 °C for 1~8 h. The characteristics, X-ray diffraction pattern, densities, contraction rate of the specimen, and swelling of the surface of the Y2O3 specimens were investigated as a function of the sintering time and glass frit addition. The Y2O3 specimen exhibited a density of over 4.9 g/cm3 as the sintering time increased, and the swelling phenomenon characteristics were improved by glass frit, by controlling particle size.
In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM’s durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca2+ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.
The aggressive scaling of dynamic random-access memory capacitors has increased the need to maintain high capacitance despite the limited physical thickness of electrodes and dielectrics. This makes it essential to use high-k dielectric materials. TiO2 has a large dielectric constant, ranging from 30~75 in the anatase phase to 90~170 in rutile phase. However, it has significant leakage current due to low energy barriers for electron conduction, which is a critical drawback. Suppressing the leakage current while scaling to achieve an equivalent oxide thickness (EOT) below 0.5 nm is necessary to control the influence of interlayers on capacitor performance. For this, Pt and Ru, with their high work function, can be used instead of a conventional TiN substrate to increase the Schottky barrier height. Additionally, forming rutile-TiO2 on RuO2 with excellent lattice compatibility by epitaxial growth can minimize leakage current. Furthermore, plasma-enhanced atomic layer deposition (PEALD) can be used to deposit a uniform thin film with high density and low defects at low temperatures, to reduce the impact of interfacial reactions on electrical properties at high temperatures. In this study, TiO2 was deposited using PEALD, using substrates of Pt and Ru treated with rapid thermal annealing at 500 and 600 °C, to compare structural, chemical, and electrical characteristics with reference to a TiN substrate. As a result, leakage current was suppressed to around 10-6 A/cm2 at 1 V, and an EOT at the 0.5 nm level was achieved.
In this work, we investigated the photo-degradation performance of MnO2-SiC fiber-TiO2 (MnO2-SiC-TiO2) ternary nanocomposite according to visible light excitation utilizing methylene blue (MB) and methyl orange (MO) as standard dyes. The photocatalytic physicochemical characteristics of this ternary nanocomposite were described by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), photocurrent and cyclic voltammogram (CV) test. Photolysis studies of the synthesized MnO2-SiC-TiO2 composite were conducted using standard dyes of MB and MO under UV light irradiation. The experiments revealed that the MnO2-SiC-TiO2 exhibits the greatest photocatalytic dye degradation performance of around 20 % with MB, and of around 10 % with MO, respectively, within 120 min. Furthermore, MnO2-SiC-TiO2 showed good stability against photocatalytic degradation. The photocatalytic efficiency of the nanocomposite was indicated by the adequate photocatalytic reaction process. These research results show the practical application potential of SiC fibers and the performance of a photocatalyst composite that combines these fibers with metal oxides.
In this study, four different samples of Se60Ge40-xBix chalcogenides glasses were synthesized by heating the melt for 18 h in vacuum Pyrex ampoules (under a 10-4 Torre vacuum), each with a different concentration (x = 0, 10, 15, and 20) of high purity starting materials. The results of direct current (DC) electrical conductivity measurements against a 1,000/T plot for all chalcogenide samples revealed two linear areas at medium and high temperatures, each with a different slope and with different activation energies (E1 and E2). In other words, these samples contain two electrical conduction mechanisms: a localized conduction at middle temperatures and extended conduction at high temperatures. The results showed the local and extended state parameters changed due to the effective partial substitution of germanium by bismuth. The density of extended states N(Eext) and localized states N(Eloc) as a function of bismuth concentration was used to gauge this effect. While the density of the localized states decreased from 1.6 × 1014 to 4.2 × 1012 (ev-1 cm-3) as the bismuth concentration increased from 0 to 15, the density of the extended states generally increased from 3.552 × 1021 to 5.86 × 1021 (ev-1 cm-3), indicating a reduction in the mullet’s randomness. This makes these alloys more widely useful in electronic applications due to the decrease in the cost of manufacturing.
Although most strains of escherichia coli (E. coli) are harmless, some serotypes can cause serious food poisoning in humans. It is very difficult to eliminate E. coli from our lives. Here we show that E. coli can be eliminated by hydroxyapatite (HAp). Because HAp has a positive charge, the material and E. coli are attracted through electrostatic interactions. Additionally, because the surface of HAp is porous, it enters the pores of the HAp surface removing them from the environment. The amount of adsorption was observed to increase over time, and the zeta potential value of the material tended to be similar to that of E. coli. This phenomenon is thought to have zeta potential similar to that of E. coli as it is adsorbed onto the HAp surface over time. E. coli stained with crystal violet was spread on a glass slide and HAp porous sol powder was dropped to remove the E. coli. We expect that this analysis will open a new direction for antibacterial materials.
Inflammatory bowel disease (IBD) is a chronic condition characterized by continuous inflammation of the gastrointestinal tract that varies in intensity over time. IBD is caused by several factors including aberrant gut flora, immunological dysregulation, altered environmental conditions, and genetic variations. However, the pathogenesis of IBD remains unclear. Studies have indicated that an imbalance between T helper 17 (Th17) and regulatory T (Treg) cells contributes significantly to the development of IBD. Intestinal Tregs suppress inflammation and are critical for maintaining tissue homeostasis. Th17 cells are known to play an important role in the development and pathogenesis of IBD and provide non-inflammatory support for the integrity of the intestinal barrier against bacterial and fungal infections. Therefore, the Th17/Treg cell balance is crucial in the pathogenesis of IBD and gut integrity. The microenvironment of the intestinal mucosal immunity is regulated by the secretion of cytokines associated with Th17 cells and Tregs. Several studies have indicated that the gut bacteria contribute to the control of the immune milieu and play a key role in the regulation of Th17 cell development. Intestinal bacteria and cytokines control Th17 cell development. Th17 cells secrete cytokines that regulate the immune microenvironment in the gut mucosa. This review provides an overview of Th17 cells and examines the strategies for treating patients with IBD using Th17 cell-targeted drugs.
This paper aims to review the odor removal performance and operating parameters of pilot and full-scale chemical scrubbers, bioscrubbers, biofilters, and biotrickling filters for odor control in wastewater treatment plants. Based on the performance of full-scale facilities installed in wastewater treatment plants, empty-bed residence times were the shortest for bioscrubbers (7.5±2.5s), followed by chemical scrubbers (20±8.1s), biotrickling filters (22.2±26.2s), and biofilters (48±30s). The removal efficiencies of complex odors by biofilters, biotrickling filters, bioscrubbers, and chemical scrubbers were 97.7±1.9%, 87.7±15.6%, 89.0±9.0%, and 70.0%, respectively. The investment cost was the lowest for biofilters, followed by biotrickling filters, bioscrubbers, and chemical scrubbers. In addition, the operating costs of these deodorization technologies were in the following order: biofilters < bioscrubbers and biotrickling filters < chemical scrubbers. However, most studies on odor control for wastewater treatment processes have been conducted on a laboratory scale with model odors (single odorous compound or mixtures of 2-3 odorous compounds). Therefore, field research to develop deodorization technologies for wastewater treatment plants should be more actively conducted to accumulate data for the design and operation of full-scale deodorizing systems.
Airborne bacteria are an important environmental factor that affects the hygiene of mushroom cultivation houses, as they can act as contaminants or pathogens in mushroom cultivation. To determine the distribution of airborne bacteria in the air of wood ear mushroom cultivation houses, air sampling and temperature and humidity measurements were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Sampled air was analyzed to measure bacterial concentration levels and identify bacterial species. There was no significant difference in temperature and humidity changes detected between the three mushroom growing houses. Additionally, the concentration of bacteria in the air did not exceed 800 CFU/m², which is the maximum amount of airborne bacteria allowed by the Ministry of Environment’s indoor air quality maintenance standards. Eleven species of bacteria belonging to 11 genera were isolated and identified from air samples. These include five species of Micrococcales, four species of Bacilli, one species of Actinomycetia, and one species of Mycobacteriales. Of the 11 species identified, five are known to affect human health. However, no mushroom pathogens or species causing food poisoning were found.
The objective of this study is to analyze the indoor air quality of multi-use facilities using an IoT-based monitoring and control system. Thise study aims to identify effective management strategies and propose policy improvements. This research focused on 50 multi-use facilities, including daycare centers, medical centers, and libraries. Data on PM10, PM2.5, CO2, temperature, and humidity were collected 24 hours a day from June 2019 to April 2020. The analysis included variations in indoor air quality by season, hour, and day of the week (including both weekdays and weekends). Additionally, ways to utilize IoT monitoring systems using big data were propsed. The reliability analysis of the IoT monitoring network showed an accuracy of 81.0% for PM10 and 76.1% for PM2.5. Indoor air quality varied significantly by season, with higher particulate matter levels in winter and spring, and slightly higher levels on weekends compared to weekdays. There was a positive correlation found between outdoor and indoor pollutant levels. Indoor air quality management in multi-use facilities requires season-specific strategies, particularly during the winter and spring. Furhtermore, enhanced management is necessary during weekends due to higher pollutant levels.
This study aimed to investigate the effectiveness of carrageenan (CGN) as an oral immune adjuvant. During the initial research, the inadvertent shallow insertion of an oral gavage needle confirmed CGN’s effect as an adjuvant for esophageal immunization. However, in oral immunization, antibody formation was not observed regardless of CGN’s presence or absence as an adjuvant. Conversely, when bovine serum albumin (used as an antigen) was introduced into the esophagus along with CGN, it resulted in the production of antigen-specific IgG. An exploration was conducted to ascertain whether CGN’s adjuvant effects were associated with prolonging the antigen’s residence time in the esophagus. Upon introducing the antigen into the esophagus without CGN, it was undetectable at two minutes post-introduction. Conversely, when administered with CGN, the antigen remained detectable in the esophagus for up to five minutes post-introduction. To investigate whether this immune response was elicited through mucosal immune mechanisms in the esophagus, the production of IgA, a representative immunoglobulin of mucosal immunity, was assessed. Following esophageal immunization with CGN as an adjuvant, total IgG, IgG1, and IgG2a were detected in serum, while IgA was not detected. These findings suggest that under specific conditions, the esophagus may serve as a site for initiating a novel immune response.
This study evaluated the importance of assessing personal exposure to volatile organic compounds (VOCs) by monitoring indoor, outdoor, and personal VOC levels in 15 Seoul residents over a 3-month period using passive samplers. Results indicated that limonene had the highest concentrations across indoor, outdoor, and personal samples, with this compound primarily originating from household cleaners and air fresheners. Other VOCs, such as 2-butanone and toluene, also varied by location. Health risk assessments showed that most VOCs had a Hazard Index (HI) below 1, while the HI of individual exposures were relatively higher. Notably, cancer risk assessments for chloroform and ethylbenzene exceeded permissible levels in some scenarios, suggesting potential cancer risks. This underscores the importance of diverse microenvironment monitoring for accurate health risk evaluations, as relying solely on indoor and outdoor levels can underestimate actual exposure risks. This study highlights the need for future research to monitor VOC levels in various microenvironments, in addition to the necessity of investigating personal activity patterns in depth to accurately assess personal exposure levels. Such an approach is crucial for precise health risk assessments, and it provides valuable foundational data for evaluating personal VOC exposures.
Antimicrobial resistance significantly threatens human and animal health globally, with considerable mortality and economic impact. This study investigated antimicrobial usage in small animal clinics in South Korea, focusing on understanding the trends in prescriptions for therapeutic and preventive purposes. Data were collected from 12 small animal clinics that were analyzed for antimicrobial prescriptions from 2018–2020. A comprehensive dataset was used, including patient signalment, clinical notes, and prescription details, and statistically analyzed using SPSS software. The results indicated that most antimicrobials (93.1%) were prescribed for the treatment of infectious diseases, with a smaller portion (6.9%) used for preventive measures, such as surgery. High prescription rates were observed for the treatment of cutaneous and otological diseases, which may reflect common diseases in companion animals. The study highlighted a higher prescription rate for adult age groups, possibly because of the higher prevalence in those groups. Overall, this study provides valuable insights into common prescription patterns in veterinary practice and underscores the need for more stringent antimicrobial stewardship to curb the rise of antimicrobial resistance. This suggests that ongoing surveillance and education on appropriate antimicrobial use are crucial for optimizing treatment outcomes and minimizing the development of resistance.
Since 2010, the Odor Prevention Act has identified and regulated four types of fatty acids as substances that cause odors. Four types of fatty acids are contributors to odor pollution and are sensitive to changes in temperature and humidity. However, the current analysis method has several limitations, including dependency on the timing of sampling before and after the procedure, as well as dependency on the specific analysis method employed. The aim of this study is to assess the efficacy of the ion chromatography analysis method by utilizing ultrapure distilled water as a means to improve the current approach. Initially, the analysis system underwent a quality assessment. The results indicated a linearity (R2) of 0.99, a limit of 10 nmol/mol or lower, supporting the conclusion that it is suitable. Furthermore, the investigation focused on the substance’s tendency to change over time in ultrapure water and under alkali absorption (0.01N NaOH). At a concentration of 0.95 ng (low-concentration standard sample), the confirmed peak area values ranged from 0.0004 μg/min to 0.0010 μg/min, resulting in an injection variation of approximately ± 0.001. At 23.7 ng (high-concentration standard sample), the peak area value fluctuated between 0.008 μg/min and 0.013 μg/ min, with an average of ± 0.002. Therefore, storing the material at temperatures below 4°C for up to 3 days (72 hours) after manufacturing seemed to facilitate the optimal conditions for maintaining its stability without significant changes taking place. Finally, blank samples from the laboratory, equipment, and site were analyzed. Out of the four substances analyzed, only n-butyl acid was detected in all three background samples. It was confirmed that it represented 4% of the peak area in the 4.94 ng standard sample.
The functional roles of plant extracts have been investigated for the treatment of various diseases including subfertility. Recent studies have highlighted the benefits of ashwagandha extract (AE) in enhancing sperm production, boosting testosterone levels, and lowering reactive oxygen species (ROS) levels in mammals. The current study is to examine the effects of the addition of AE to liquid boar semen on sperm quality during storage and its potential application in assisted reproductive technology. A hot water extract of ashwagandha was prepared from the dried powder of ashwagandha roots. Boar spermatozoa were stored in Beltsville thawing solution (BTS) at 17℃ for 5 days, with various concentrations of AE (1–50 mg/mL). During storage, motility, viability, acrosomal integrity and ROS of boar spermatozoa were examined. The results have shown that sperm stored in BTS with varying quantities of AE ranging from 1–20 mg/mL exhibited higher motility compared to those without AE (control) or with 50 mg/mL AE for 5 days. Similarly, sperm viability was better maintained in sperm treated with 1–20 mg/mL AE. Moreover, sperm stored in BTS with AE led to significantly higher acrosomal integrity and chromatin stability rates than sperm stored without AE. Notably, intracellular ROS levels significantly decreased in sperm stored in BTS with AE. Particularly, spermatozoa stored at 10 mg/mL AE exhibited an effective reduction in ROS during storage. These findings suggest the potential role of AE as an additive during sperm storage maintains sperm quality and can be used during subfertility treatment in both animals and humans.
Traditional medicine and herbal remedies are gaining popularity worldwide, comprising a significant portion of healthcare research, advancements, and market demand. Growing scientific evidence supports their substantial efficacy as pharmaceutical ingredients and dietary supplements in preventive healthcare. When developing pharmaceuticals, it is crucial to ensure that ingredients are free from side effects and toxicity in order to prioritize safety. Geckos, known as shou gong, are a diverse group of lizards that are widely utilized for treating various diseases in Korean Medicine. This study was conducted to assess the potential acute toxicity of a water extract Gekko gecko by a single oral dose in Sprague-Dawley rats. Twenty rats of each sex were randomly assigned to four groups (5 rats each). Test articles were administrated once by oral gavage to rats at dose levels of 0, 500, 1,000, or 2,000 mg/kg body weight. Mortality, changes of body weight, and clinical signs of gross observation were monitored for 14 days after dosing. At the end of a 14-day observation period, all animals were sacrificed and complete macroscopic and hematological examinations were performed. There was no dead animal or test article-related effect on clinical signs, body weight, or gross finding. Other specific changes were not found between control and treated groups in hematology. Results showed no adverse effect at a dose of 500, 1,000, or 2,000 mg/kg in rats. The minimal lethal dose was considered to be over 2,000 mg/kg body weight in rats.
Drug-induced liver injury (DILI) is considered to be a significant cause of drug wastage. To mitigate clinical DILI risks, assessing drugs using human liver models is crucial since animal studies may fall short due to species-specific liver pathway variations. Cell-based preclinical hepatotoxicity testing is often pertinent. In the present study, cells from a human liver cancer line (HepG2 and HepaRG) were cultured in both formats of 2D and 3D spheroids to explore their responses to drugs. Liver-specific marker expressions across cell lines and culture formats were also examined to assess disparities in DILI marker expressions. After treating each cell with the drugs, cytotoxicity and liver injury markers aspartate aminotransferase and alanine aminotransferase were increased. In addition, liver specific markers albumin and urea decreased in a drug concentration-dependent manner. These findings were consistent with drug sensitivity. Additionally, mRNA expression levels of cytochrome P450 enzymes (CYPs) involved in hepatocellular drug metabolism were compared following treatment with enzyme inducers. CYP1A2 and CYP2C9 were not epxressed in HepG2 cells. HepaRG cells exhibited significantly increased expression of CYP1A2, 2C9, and 3A4 post-treatment. Notably, enzyme expression was notably higher in 3D cultures than in 2D cultures. Collectively, these findings suggest that HepaRG cells and 3D cultures hold promise for evaluating DILI during early-stage drug development.
Caprine cryptosporidiosis mainly occurs in young goats, with morbidity rates of 80%–100% and mortality over 50% in goat kids. However, limited research has been conducted on the impact of Cryptosporidium parvum, a diarrhea-causing pathogen, on the intestinal microbiota of goat kids. In this study, 16S rRNA-based metataxonomic analysis was performed to compare the microbial diversity and abundance of the gut microbiota between C. parvum-infected and uninfected goat kids. In total, 12 goat fecal samples were collected, including seven naturally C. parvum-infected and five uninfected goats from Chungcheongbuk-do, Korea. After amplification of the V3–V4 hypervariable region of the bacterial 16S rRNA, high-throughput sequencing was performed. The results showed differences in the microbial composition between C. parvum-infected and uninfected groups based on beta diversity. Firmicutes and Bacteroidetes were the most dominant phyla in both groups. However, no significant difference was observed in the Bacteroidetes/Firmicutes ratio between the two groups. Compared with the uninfected group, the C. parvum-infected group showed significantly higher abundances of Tyzzerella nexillis, Lactobacillus johnsonii, Butyricicoccus pullicaecorum, Enterococcus raffinosus, Enterococcus faecalis, and Negativicoccus massiliensis, and significantly reduced abundances of Aerococcus vaginalis, Faecalicoccus pleomorphus, Oribacterium parvum, and Coprococcus comes. These findings indicate that C. parvum infection, which is associated with diarrhea in neonatal goats, induces alterations in the caprine gut microbiota.
This study was conducted to collect the patents of microbiome-based treatment technology for pets. An electronic search for microbiome or probiotics in brain nervous system disease was studied using the WINTELIPS database. Patent Cooperation Treaty of Korea, Japan, the EU, the US, and China that were registered by October 31, 2022 were selected in this study. A total of 206 patents were included for final analysis. Since 2016, patent activity has shown an explosive increase in recent years. China is the leading market in this technology field, and Korea has the second-highest market share. To provide the groundwork for the next research and development, we examined the industrial trend of microbiome for brain nervous system diseases in this study using an analysis of patents that have been applied for and registered up to this point. Looking at the overall patent trends by year in the technology field related to treating of brain and nervous system diseases using the microbiome, there was a tendency to repeat increasing and decreasing trends. However, considering 2021 and 2022, which have undisclosed sections, it can be seen that patent activity has tended to increase explosively in recent years, starting in 2016. If related studies use the patent analysis data constructed in this way strategically, it is expected that it will lead to patent registration and the development of new products, ultimately contributing to the revitalization of the companion animal industry.