In Vitro Effects of Zinc Compounds on the Candidacidal Activities of Salivary Antimicrobials.

OBJECTIVE: This study aimed to investigate the effects of zinc compounds on the candidacidal activities of lysozyme and the peroxidase (PO) and glucose oxidase-mediated peroxidase (GO-PO) systems against Candida albicans. METHODS: Four zinc compounds were used: zinc chloride, gluconate, lactate, and sulphate. Three antimicrobial systems were used: hen egg-white lysozyme (HEWL), the PO system [bovine lactoperoxidase (bLPO), potassium thiocyanate, and hydrogen peroxide], and the GO-PO system (bLPO, potassium thiocyanate, glucose oxidase, and glucose). Three Candida albicans strains were used: ATCC 10231, 11006, and 18804. The candidacidal activity of each zinc compound-antimicrobial system mixture was compared with that of the zinc compound or antimicrobial system alone. RESULTS: The addition of zinc chloride and gluconate significantly (P < .05) increased the candidacidal activity of HEWL in the ATCC 10231 and 11006 strains. Regarding the PO system, the addition of zinc sulphate in the ATCC 10231 strain and of zinc chloride or gluconate in the ATCC 18804 strain significantly (P < .05) increased the candidacidal activity compared with the PO system alone. No significant changes were observed in the candidacidal activities of the mixture of each zinc compound and the GO-PO system compared with the GO-PO system alone for all three C. albicans strains. CONCLUSIONS: Although it depended on the type of zinc compound or strain, the addition of zinc compounds increased the candidacidal activities of antimicrobial enzymes against C. albicans compared with HEWL or the PO system alone. The introduction of zinc compounds into oral healthcare products containing antimicrobials could provide additional antifungal activity.

Gender disparity regarding the impact of retirement on marital satisfaction: Evidence from a longitudinal study of older Korean adults.

OBJECTIVE: To investigate the impact of retirement on marital satisfaction by gender on Koreans aged >45 years in a large, nationally representative cohort. METHODS: Retirement status and marital satisfaction data of 5867 individuals were analysed. Marital dissatisfaction was defined as a satisfaction score reduction of more than 10 points versus the previous wave. Lagged generalised estimating equation (GEE) models adjusted for demographics (age, sex, education level and household income), health-related habits (smoking and drinking status) and comorbidities (obesity, hypertension, type 2 diabetes, and depression and frailty) were used to confirm the relationship between retirement and marital dissatisfaction. RESULTS: The final GEE model adjusted for covariates revealed sex-specific differences in marital satisfaction after retirement. Whereas male retirees reported higher satisfaction than non-retired men, female retiree responses revealed lower satisfaction than non-retired women. Furthermore, these trends were consistent regardless of the time elapsed after retirement. CONCLUSIONS: Marital satisfaction should be screened in women during the transition to retirement.

Exploration of Compounds with 2-Phenylbenzo[d]oxazole Scaffold as Potential Skin-Lightening Agents through Inhibition of Melanin Biosynthesis and Tyrosinase Activity.

Inspired by the potent tyrosinase inhibitory activity of phenolic compounds with a 2-phenylbenzo[d]thiazole scaffold, we explored phenolic compounds 1-15 with 2-phenylbenzo[d]oxazole, which is isosterically related to 2-phenylbenzo[d]thiazole, as novel tyrosinase inhibitors. Among these, compounds 3, 8, and 13, featuring a resorcinol structure, exhibited significantly stronger mushroom tyrosinase inhibition than kojic acid, with compound 3 showing a nanomolar IC50 value of 0.51 µM. These results suggest that resorcinol plays an important role in tyrosinase inhibition. Kinetic studies using Lineweaver-Burk plots demonstrated the inhibition mechanisms of compounds 3, 8, and 13, while docking simulation results indicated that the resorcinol structure contributed to tyrosinase binding through hydrophobic and hydrogen bonding interactions. Additionally, these compounds effectively inhibited tyrosinase activity and melanin production in B16F10 cells and inhibited B16F10 tyrosinase activity in situ in a concentration-dependent manner. As these compounds showed no cytotoxicity to epidermal cells, melanocytes, or keratinocytes, they are appropriate for skin applications. Compounds 8 and 13 demonstrated substantially higher depigmentation effects on zebrafish larvae than kojic acid, even at 800- and 400-times lower concentrations than kojic acid, respectively. These findings suggest that 2-phenylbenzo[d]oxazole is a promising candidate for tyrosinase inhibition.

Exploring 2-mercapto-N-arylacetamide analogs as promising anti-melanogenic agents: in vitro and in vivo evaluation.

Based on the hypothesis that the 2-mercaptoacetamide moiety chelates the copper ions of tyrosinase, 2-mercapto-N-arylacetamide (2-MAA) analogs were designed and synthesized as potential tyrosinase inhibitors. Four 2-MAA analogs showed low IC50 values ranging from 0.95 to 2.0 µM against mushroom tyrosinase, which was 12-26 times lower than that of kojic acid (IC50 value = 24.3 µM). However, according to a copper ion chelation experiment performed, the 2-MAA analogs did not participate in chelation with copper ions. To identify the mode of inhibition of the 2-MAA analogs, kinetic studies were performed, and the results were supported by docking results. In addition, docking simulation results suggested that the 2-MAA analogs strongly inhibited tyrosinase activity because of the hydrogen bonding of the amide NH group and the hydrophobic interaction of the aryl ring instead of chelation with copper ions. In experiments using B16F10 cells, 2-MAA analogs were shown to inhibit melanin production by inhibiting cellular tyrosinase activity. Western blotting showed that in addition to directly inhibiting tyrosinase activity, analog 7 also has an anti-melanogenic effect by inhibiting the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. The 2-MAA analogs showed no appreciable cytotoxicity against HaCaT and B16F10 cells, making them suitable for dermal applications. In a depigmentation experiment using zebrafish embryos, analogs 1 and 2 showed more potent depigmentation effects than kojic acid even at 1000 times lower concentration than that of kojic acid. These results suggest that the 2-MAA analogs are promising anti-melanogenic agents that can inhibit most tyrosinases in various species.

Modification of the association between cold spells and cardiovascular disease by changes in natural gas prices: A nationwide time-series study.

BACKGROUND: Although the association between low ambient temperature and cardiovascular disease (CVD) is well-established, the effect of winter energy prices on this association remains unknown. AIM: This ecological study aimed to investigate whether changes in natural gas prices (NGP), which account for a significant portion of winter energy prices in Korea, affect the association of cold spells with hospital admissions and mortality due to CVD. METHODS: Data from the National Health Insurance Service and Statistics Korea were used to determine the daily number of hospital admissions and mortality rates associated with CVD. From January 2012 to February 2017, the NGP continually increased by 24.1%. From January 2012 to December 2014 the NGP continually decreased by 32.6% owing to the Korea Gas Corporation's management decisions, independent of external socioeconomic factors. We investigated the differences in the associations between cold spells and CVD-related outcomes in price-increasing and price-decreasing periods using a Poisson regression with a distributed lag nonlinear model. Cold spells were assessed on two consecutive days at the 5th percentile of the temperature for each region. RESULTS: The meteorological factors and air pollution levels were similar between the two periods. The association between cold spells and hospital admissions due to CVD was stronger during the price-increasing period than during the price-decreasing period [ratio of cumulative relative risk (RRR) = 1.71, 95% confidence interval (CI): 1.31-2.22]. The difference in the association with mortality due to CVD between the two periods was not significant, although the point estimate remained >1 (RRR = 1.11, 95% CI: 0.90-1.38). CONCLUSIONS: Changes in energy prices may modify the cold spell-related CVD risk, possibly by inducing behavioral changes to manage energy expenditure. Policymakers should take into account the potential public health implications of changes in energy prices, alongside their economic effects.

Pushing the Limits of Photoconductivity via Hot Electrons in Deep Trap States in Plasmonic Architectures.

Although extensive research on the mechanisms of photoconductivity enhancement in plasmonic Schottky structures has been conducted, the photoconductive interplay between hot electrons and trapping states remains elusive. In this study, we explored the photoconductive relationship between plasmonic hot-carriers and defect sites present in plasmonic architectures consisting of N-face n-GaN and Au nanoprisms. Our experimental results clearly verified that the plasmonic hot-electrons generated by interband transitions preferentially occupied deep trap levels in n-GaN, thereby considerably enhancing the photoconductivity through the combination of photogating and photovoltaic effects. Our quantitative evaluation demonstrated that a mere 63% increase in hot-electron trapping leads to a 1.7-fold increased photocurrent under localized surface plasmon resonance (LSPR) excitation compared to the figure of photocurrent under non-LSPR stimulus. Our findings provide novel insights into the mechanisms of photoconductive enhancement for advanced plasmonic applications.

The impact of ageism experiences on social participation among community-dwelling older adults: Exploring the moderating role of digital literacy.

OBJECTIVES: This study examined how digital literacy moderates the relationship between ageism experiences and social participation among community-dwelling older adults. METHODS: Regression analysis of data from the 2020 National Survey of Older Koreans with 9,920 participants was conducted to identify the association of ageism experiences with social participation in model 1. The moderating effects of digital literacy were examined by adding an interaction term in model 2. RESULTS: In model 1, both ageism experiences and digital literacy were significant predictors of social participation. However, in model 2, the interaction term of digital literacy rendered the association between ageism experiences and social participation non-significant. Model 2 explained approximately 18.4 % of the total variance in social participation. CONCLUSIONS: By highlighting the importance of digital literacy in increasing social participation among older adults, this study offers valuable insights for interventions aimed at improving digital literacy to promote successful aging in a technology-dependent society.

Epidemiology of pediatric inflammatory bowel disease categorized by age subgroups in Korea.

BACKGROUND: Pediatric inflammatory bowel disease (PIBD) affects different age groups and its incidence is increasing worldwide. However, there is a lack of research focusing on age subgroups in Asian countries. In this nationwide population-based study, we investigated the epidemiology of PIBD among different age subgroups in Korea. METHODS: We analyzed Korean health administration data from 2005 to 2016. Data were divided by age at diagnosis as follows: group 1, 0-1 years; group 2, 2-5 years; group 3, 6-9 years; group 4, 10-16 years. We analyzed the overall incidence, temporal changes, and regional differences by age subgroups, using Poisson regression analysis. RESULTS: From 2005 to 2016, 2734 inflammatory bowel disease (IBD) cases were diagnosed among patients under 17 years of age. In the overall population, the incidence rate of PIBD over the entire study period was 2.248/105 person-years (PY), significantly increasing from 1.173/105 PY in 2005-2007 to 3.267/105 PY in 2014-2016. The incidence rates in groups 1 and 2 remained unchanged, whereas those of groups 3 and 4 increased significantly. The same trend was observed when analyzed separately for Crohn's disease (CD) and ulcerative colitis (UC). The incidence rates of CD in groups 3 and 4 showed differences between metropolitan and non-metropolitan areas, whereas those in groups 1 and 2, and UC of all age subgroups showed no difference. CONCLUSIONS: The temporal trend and regional differences of PIBD differed among age subgroups, suggesting that genetic and environmental factors have varying impacts on IBD development across different subgroups.

Molecular surveillance of zoonotic pathogens from wild rodents in the Republic of Korea.

BACKGROUND: Rodents are recognized as major reservoirs of numerous zoonotic pathogens and are involved in the transmission and maintenance of infectious diseases. Furthermore, despite their importance, diseases transmitted by rodents have been neglected. To date, there have been limited epidemiological studies on rodents, and information regarding their involvement in infectious diseases in the Republic of Korea (ROK) is still scarce. METHODOLOGY/PRINCIPAL FINDINGS: We investigated rodent-borne pathogens using nested PCR/RT-PCR from 156 rodents including 151 Apodemus agrarius and 5 Rattus norvegicus from 27 regions in eight provinces across the ROK between March 2019 and November 2020. Spleen, kidney, and blood samples were used to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato group, Coxiella burnetii, Leptospira interrogans, and severe fever with thrombocytopenia syndrome virus (SFTSV). Of the 156 rodents, 73 (46.8%) were infected with Bartonella spp., 25 (16.0%) with C. burnetii, 24 (15.4%) with L. interrogans, 21 (13.5%) with A. phagocytophilum, 9 (5.8%) with SFTSV, and 5 (3.2%) with Borrelia afzelii. Co-infections with two and three pathogens were detected in 33 (21.1%) and 11 rodents (7.1%), respectively. A. phagocytophilum was detected in all regions, showing a widespread occurrence in the ROK. The infection rates of Bartonella spp. were 83.3% for B. grahamii and 16.7% for B. taylorii. CONCLUSIONS/SIGNIFICANCE: To the best of our knowledge, this is the first report of C. burnetii and SFTSV infections in rodents in the ROK. This study also provides the first description of various rodent-borne pathogens through an extensive epidemiological survey in the ROK. These results suggest that rodents harbor various pathogens that pose a potential threat to public health in the ROK. Our findings provide useful information on the occurrence and distribution of zoonotic pathogens disseminated among rodents and emphasize the urgent need for rapid diagnosis, prevention, and control strategies for these zoonotic diseases.

Highly potent anti-melanogenic effect of 2-thiobenzothiazole derivatives through nanomolar tyrosinase activity inhibition.

Compounds with sulfhydryl substituents and azole compounds exhibit potent anti-tyrosinase potency. 2-Thiobenzothiazole (2-TBT), a hybrid structure of sulfhydryl and azole, exists in two tautomeric forms, with the thione form being predominant according to several studies. 2-TBT derivatives were synthesized as potential tyrosinase inhibitors as the thione tautomeric form has the same N-CS moiety as phenylthiourea (PTU), which is suitable for chelation with the copper ions present in the tyrosinase active site. Eight of the ten 2-TBT derivatives inhibited the monophenolase and diphenolase activities of mushroom tyrosinase, with IC50 values of 0.02-0.83 µM. Kinetic studies and molecular dynamics simulations were performed to determine their mode of action and confirm that the 2-TBT derivatives bind to the tyrosinase active site with high stability. Derivatives 3, 4, 8, and 10 strongly inhibited melanogenesis in B16F10 cells in a pattern similar to the results of cellular tyrosinase inhibition, thereby suggesting that their ability to inhibit melanogenesis was due to their tyrosinase inhibitory activity. In a depigmentation experiment using zebrafish embryos, all 2-TBT derivatives showed better potency than kojic acid, even at 400 to 2000 times lower concentration, and 1 and 10 reduced zebrafish larva pigmentation more strongly than PTU even at 20 times lower concentration. Experiments investigating the changes in tyrosinase inhibitory activity of 2-TBT derivatives in the presence and absence of CuSO4 and their copper chelating ability supported that these derivatives exert their anti-melanogenic effect by chelating the copper ions of tyrosinase. These results suggest that 2-TBT derivatives are promising candidates for the treatment of hyperpigmentation-related disorders.

Robust and customizable spheroid culture system for regenerative medicine.

Three-dimensional cell spheroids show promise for the reconstruction of native tissues. Herein, we report a sophisticated, uniform, and highly reproducible spheroid culture system for tissue reconstruction. A mesh-integrated culture system was designed to precisely control the uniformity and reproducibility of spheroid formation. Furthermore, we synthesized hexanoyl glycol chitosan, a material with ultralow cell adhesion properties, to further improve spheroid formation efficiency and biological function. Our results demonstrate improved biological function in various types of cells and ability to generate spheroids with complex structures composed of multiple cell types. In conclusion, our spheroid culture system offers a highly effective and widely applicable approach to generating customized spheroids with desired structural and biological features for a variety of biomedical applications.

Design, synthesis, and anti-melanogenic efficacy of 2-mercaptobenzoxazoles with nanomolar tyrosinase activity inhibition.

Tyrosinase is a metalloenzyme that contains copper(II) ions. We designed and synthesized eight known low-molecular-weight 2-mercaptobenzoxazole (2-MBO) analogs as tyrosinase inhibitors. Our focus was on the mercapto functional group, which interacts with copper ions. Analogs 1-3 exhibited mushroom tyrosinase inhibitory activity at the nanomolar level and demonstrated strong potency with extremely low half-maximal inhibitory concentration (IC50) values of 80-90 nM for l-dopa and 100-240 nM for l-tyrosine. Analogs 2, 4, and 5 showed the most potent anti-melanogenic effects in B16F10 cells, and their mode of action was demonstrated by kinetic analysis. Their anti-melanogenic effects were similar to the tyrosinase inhibition results, suggesting that their anti-melanogenic effects could be attributed to their tyrosinase inhibitory ability. Experiments using copper-chelating activity assays and changes in tyrosinase inhibitory activity with and without CuSO4 demonstrated that 2-MBO analogs inhibit tyrosinase activity by chelating the copper ions of tyrosinase. In conclusion, the 2-MBO analogs show potential as anti-melanogenic agents with potent tyrosinase inhibitory activity.

Quality controlled YouTube content intervention for enhancing health literacy and health behavioural intention: A randomized controlled study.

Background: Individuals increasingly turn to the Internet for health information, with YouTube being a prominent source. However, the quality and reliability of the health information vary widely, potentially affecting health literacy and behavioural intentions. Methods: To analyse the impact of health information quality on health literacy and behavioural intention, we conducted a randomized controlled trial using a quality-controlled YouTube intervention. Health information quality on YouTube was evaluated using the Global Quality Score and DISCERN. We randomly allocated (1 : 1) to the intervention group to watch the highest quality-evaluated content and to the control group to watch the lowest quality-evaluated content. Health literacy and health behavioural intention were assessed before and after watching YouTube. The trial was set for two different topics: interpreting laboratory test results from health check-up and information about inflammatory bowel disease (IBD). Results: From 8 April 2022 to 15 April 2022, 505 participants were randomly assigned to watch either high-quality content (intervention group, n = 255) or low-quality content (control group, n = 250). Health literacy significantly improved in the intervention group (28.1 before and 31.8 after; p < 0.01 for health check-up; 28.3 before and 31.3 after; p < 0.01 for IBD). Health behavioural intention significantly improved in the intervention group (3.5 before and 4.1 after; p < 0.01 for health check-up; 3.6 before and 4.0 after; p < 0.01 for IBD). Control groups had no such effect. Conclusion: High-quality health information can enhance health literacy and behavioural intention in both healthy individuals and those with specific conditions like IBD. It stresses the significance of ensuring reliable health information online and calls for future efforts to curate and provide access to high-quality health content.

Investigation of the Efficacy of Benzylidene-3-methyl-2-thioxothiazolidin-4-one Analogs with Antioxidant Activities on the Inhibition of Mushroom and Mammal Tyrosinases.

Based on the fact that substances with a ß-phenyl-α,ß-unsaturated carbonyl (PUSC) motif confer strong tyrosinase inhibitory activity, benzylidene-3-methyl-2-thioxothiazolidin-4-one (BMTTZD) analogs 1-8 were prepared as potential tyrosinase inhibitors. Four analogs (1-3 and 5) inhibited mushroom tyrosinase strongly. Especially, analog 3 showed an inhibitory effect that was 220 and 22 times more powerful than kojic acid in the presence of l-tyrosine and l-dopa, respectively. A kinetic study utilizing mushroom tyrosinase showed that analogs 1 and 3 competitively inhibited tyrosinase, whereas analogs 2 and 5 inhibited tyrosinase in a mixed manner. A docking simulation study indicated that analogs 2 and 5 could bind to both the tyrosinase active and allosteric sites with high binding affinities. In cell-based experiments using B16F10 cells, analogs 1, 3, and 5 effectively inhibited melanin production; their anti-melanogenic effects were attributed to their ability to inhibit intracellular tyrosinase activity. Moreover, analogs 1, 3, and 5 inhibited in situ B16F10 cellular tyrosinase activity. In three antioxidant experiments, analogs 2 and 3 exhibited strong antioxidant efficacy, similar to that of the positive controls. These results suggest that the BMTTZD analogs are promising tyrosinase inhibitors for the treatment of hyperpigmentation-related disorders.

Interferon-Gamma Release Assay Combined with Renal Indicators to Reduce the False-Negativity of Latent Tuberculosis Infection in End-Stage Renal Disease with Hemodialysis Patients.

BACKGROUND: Tuberculosis (TB) is still the main cause of mortality due to a single transfectant, Mycobacterium tuberculosis (MTB). Latent tuberculosis infection (LTBI) is a condition characterized by the presence of tuberculosis (TB) that is not clinically apparent but nonetheless shows a sustained response to MTB. Presently, tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are mainly used to detect LTBI via cell-mediated immunity of T-cells. For people with end-stage renal disease (ESRD), the diagnosis of patients infected with MTB is difficult because of T-cell dysfunction. To get more accurate diagnosis results of LTBI, it must compensate for the deficiency of IGRA tests. METHODS: Sixty-seven hemodialysis (HD) patients and 96 non-HD patients were enrolled in this study and the study population is continuously included. IFN-γ levels were measured by the QuantiFERON-TB Gold In-Tube (QFT-GIT) test. Kidney function indicators, blood urea nitrogen (BUN), serum creatinine (Cr), and estimated glomerular filtration rate (eGFR) were used to compensate for the declined IFN-γ levels in the IGRA test. RESULTS: In individuals who were previously undetected, the results of compensation with serum Cr increased by 10.81%, allowing for about 28% more detection, and compensation with eGFR increased by 5.41%, allowing for approximately 14% more detectable potential among them and employing both of them could enhance the prior shortcomings of IGRA tests. when both are used, the maximum compensation results show a sensitivity increase rate of 8.81%, and approximately 23% of patients who were previously undetectable may be found. CONCLUSION: Therefore, the renal function markers which are routine tests for HD patients to compensate for the deficiency of IGRA tests could increase the accuracy of LTBI diagnosis.

Sensors and Sensing Devices Utilizing Electrorheological Fluids and Magnetorheological Materials-A Review.

This paper comprehensively reviews sensors and sensing devices developed or/and proposed so far utilizing two smart materials: electrorheological fluids (ERFs) and magnetorheological materials (MRMs) whose rheological characteristics such as stiffness and damping can be controlled by external stimuli; an electrical voltage for ERFs and a magnetic field for MRMs, respectively. In this review article, the MRMs are classified into magnetorheological fluids (MRF), magnetorheological elastomers (MRE) and magnetorheological plastomers (MRP). To easily understand the history of sensing research using these two smart materials, the order of this review article is organized in a chronological manner of ERF sensors, MRF sensors, MRE sensors and MRP sensors. Among many sensors fabricated from each smart material, one or two sensors or sensing devices are adopted to discuss the sensing configuration, working principle and specifications such as accuracy and sensitivity. Some sensors adopted in this article include force sensors, tactile devices, strain sensors, wearable bending sensors, magnetometers, display devices and flux measurement sensors. After briefly describing what has been reviewed in a conclusion, several challenging future works, which should be undertaken for the practical applications of sensors or/and sensing devices, are discussed in terms of response time and new technologies integrating with artificial intelligence neural networks in which several parameters affecting the sensor signals can be precisely and optimally tuned. It is sure that this review article is very helpful to potential readers who are interested in creative sensors using not only the proposed smart materials but also different types of smart materials such as shape memory alloys and active polymers.

Association of midlife body-weight variability and cycles with earlier dementia onset: a nationwide cohort study.

BACKGROUND: Given the rising awareness of health-related lifestyle modifications, the impact of changes in body weight (BW) on cognitive function and dementia generates significant concern. This study aimed to investigate the association between BW changes and dementia in a middle-aged Korean population. METHODS: A retrospective, population-based longitudinal study was conducted utilizing data from the National Health Insurance Service (NHIS) database. Participants aged 40 years or older in 2011 who underwent at least five health checkups between 2002 and 2011 were followed-up for dementia until 2020. A total of 3,635,988 dementia-free Korean aged < 65 at baseline were examined. We analyzed the association between BW variability independent of the mean (VIM) with BW cycle, defined as either an upward or a downward direction of BW, and the risk of incident dementia. RESULTS: The results showed an increased risk of dementia in the highest quartile of VIM quartile (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.47-1.58) compared to the lowest quartile of VIM. Additionally, the results showed an even higher increased risk of dementia in the highest BW cycle (≥ 2 cycles of 10% BW = HR 2.00, 95% CI 1.74-1.29). Notably, the combined concept of VIM with BW cycle showed an even higher dementia risk (highest quartile of VIM with ≥ 2 cycles of 10% BW = HR 2.37, 95% CI 2.05-2.74) compared to the baseline group (lowest quartile of VIM with < 3% BW cycle). CONCLUSIONS: The present study highlights the importance of considering BW changes with BW variability along with the BW cycle to assess dementia risk in detail, providing valuable insights for preventive strategies.

Evaluation of haematological parameters in haemolytic anaemia caused by tick-borne pathogens in grazing cattle.

BACKGROUND: No tick-borne pathogens (TBPs) causing haemolytic anaemia in cattle have been reported, except Theileria orientalis and complete blood count (CBC) profile is the only haematological parameter to determine the severity of regenerative haemolytic anaemia. OBJECTIVES: To identify the causative agents of TBP-induced haemolytic anaemia and determine haematological parameters that indicate haemolytic anaemia in grazing cattle. METHODS: Eighty-two Korean indigenous cattle (Hanwoo) were divided into two groups: grazing (n = 67) and indoor (n = 15) groups. CBC and serum biochemistry were performed. PCR was conducted using whole blood-extracted DNA to investigate the prevalence of TBPs. RESULTS: TBP-induced haemolytic anaemia was observed in the grazing group. In grazing cattle, co-infection (43.3%, 29/67) was most frequently detected, followed by T. orientalis (37.6%, 25/67) and Anaplasma phagocytophilum infections (1.5%, 1/67). In indoor cattle, only co-infection (20%, 3/15) was identified. Grazing cattle exhibited regenerative haemolytic anaemia with marked monocytosis, mild neutropenia, and thrombocytopenia. According to grazing frequency, the 1st-time grazing group had more severe anaemia than the 2nd-time grazing group. Elevations in indirect bilirubin and L-lactate due to haemolytic anaemia were identified, and correlations with the respective markers were determined in co-infected grazing cattle. CONCLUSIONS: Quantitative evaluation of haematocrit, mean corpuscular volume, and reticulocytes (markers of regenerative haemolytic anaemia in cattle) was performed for the first time. Our results show that, in addition to T. orientalis, A. phagocytophilum is strongly associated with anaemia. The correlation between haemolytic anaemia severity and haematological parameters (indirect bilirubin, reticulocytes, and L-lactate) was confirmed.

Revealing the Loss Mechanism of Chemically-Induced Hot Electron Transport.

Hot electrons are crucial for unraveling the intrinsic relationship between chemical reactions and charge transfer in heterogeneous catalysis. Significant research focused on real-time detection of reaction-driven hot electron flow (chemicurrent) to elucidate the energy conversion mechanisms, but it remains elusive because carrier generation contributes to only part of the entire process. Here, a theoretical model for quantifying the chemicurrent yield is presented by clarifying the contributions of hot carrier losses from the internal emission and multiple reflections. The experimental chemicurrent yield verifies our model with a reliable mean free path of hot electrons, emphasizing the importance of comprehensive consideration of the transport process besides hot electron generation. Moreover, Pt nanoparticles (NPs)-decorated Au/TiO2 is examined, showing the role of NPs-induced carrier losses in the performance of catalytic nanodiodes. These findings are expected to contribute to understanding the hot electron detection efficiency and designing nanodiodes with enhanced hot carrier flow and catalytic activity.

Preliminary report of Mycoplasma Wenoynii and Candidatus Mycoplasma haemobos infection in Korean native cattle.

BACKGROUND: Hemotropic mycoplasmas or hemoplasmas are bacteria that attach to the erythrocyte surface and cause bovine hemoplasmosis. Two species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been identified and shown to be distributed worldwide. However, there is currently no information available on hemoplasmas in cattle in the Republic of Korea. The aim of this study was to investigate the presence of hemoplasmas in Korean native cattle and to evaluate the association between hemoplasma infection and anemia. METHODS: One farm was selected, at which blood samples were collected from 104 Korean native cattle [grazing cattle (n = 89) and housed cattle (n = 15)]. Hemoplasmas were detected via polymerase chain reaction analysis and complete blood counts were also performed. RESULTS: The overall prevalence of hemoplasmas was 34% (35/104); 20.2% (21/104) for M. wenyonii, 3.8% (4/104) for C. M. haemobos, and 9.6% (10/104) for co-infection. Candidatus Mycoplasma haemobos was detected only in grazing cattle. Of red blood cell (RBC) parameters, C. M. haemobos-infected cattle had lower RBC and hematocrit, and higher mean cell volume than hemoplasma-negative cattle, although none of these differences were statistically significant. This is the first study to report the occurrence of M. wenyonii and C. M. haemobos. Mycoplasma wenyonii is more prevalent than C. M. haemobos in Korean native cattle. The results did not show an association between hemoplasma infection and anemia. CONCLUSIONS: Considering the infection rate of hemoplasmas shown in this study, further studies, such as on the pathogenicity and clinical significance of hemoplasmas are necessary.