Building of Pediatric COVID-19 Module Clinic: A Novel Operation Model in Response to COVID-19 Pandemic.

In mid-2022, as the wave of pediatric coronavirus disease 2019 (COVID-19) cases escalated in South Korea, a public-private partnership was made to establish a Pediatric COVID-19 Module Clinic (PMC). We describe the utilization of the first prototype children's modular clinic in Korea University Anam Hospital functioning as the COVID-19 PMC. Between August 1 and September 30, 2022, a total of 766 children visited COVID-19 PMC. Daily number of patient visits to the COVID-19 PMC ranged between 10 and 47 in August; and less than 13 patients per day in September 2022. Not only the model provided timely care for the COVID-19 pediatric patients, but it also enabled safe and efficacious care for the non-COVID-19 patients in the main hospital building while minimizing exposure risk to severe acute respiratory syndrome coronavirus 2 transmission. Current description highlights the importance of spatial measures for mitigating in-hospital transmission of COVID-19, in specifically on pediatric care.

Comamonas suwonensis sp. nov., isolated from stream water in the Republic of Korea.

A novel bacterial strain, EJ-4T, isolated from stream water collected at Seo-ho in Suwon, Republic of Korea, was characterized based on a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain EJ-4T belonged to the genus Comamonas. The isolate is Gram-stain-negative, non-motile, aerobic, rod-shaped and forms pale yellow colonies on trypticase soy agar. The optimal growth of this strain was observed aerobically at 30 °C, pH 7 and 0.5 % NaCl. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 39.7 %) and C16 : 0 (32.0 %). The G+C content of strain EJ-4T was 58.4mol %. The average nucleotide identity and digital DNA-DNA hybridization values between strain EJ-4T and Comamoas testosteroni were 91.8 and 31.2 %, respectively. The major polar lipids detected in the isolate were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant isoprenoid quinone was ubiquinone-8. Based on the results of polyphasic taxonomic analysis of strain EJ-4T, we describe a novel species of the genus Comamonas, for which the name Comamonas suwonensis sp. nov. has been proposed, with EJ-4T (=KCTC 82074T=JCM 34179T=KEMB 1602-279T) as the type strain.

Trend of Antibiotic Use in Children with Acute Otitis Media in Korea.

Public interventions have shown to optimize the use of antibiotics in children with acute otitis media (AOM). In this study, we describe the AOM-related antibiotic use among children in South Korea using national cohort data. We retrieved the Health Insurance Review & Assessment Service data to construct a national cohort of children aged 0-6 years who had been diagnosed with AOM between 2012 and 2018. Of 25,212,264 children included, the antibiotic prescription has increased for amoxicillin/amoxicillin-clavulanate from 56.1% in 2012 to 61.8% in 2018. Prescription has decreased for cephalosporin (35.1% in 2012 to 31.8% in 2018) and macrolide (8.7% in 2012 to 6.4% in 2018). National cohort data have shown an increased trend in AOM-related aminopenicillin prescription and downward trend cephalosporin and macrolide use in South Korea. A multi-faceted approach is required to control the antimicrobial resistance at a population level.

Comprehensive Immuno-Molecular Profiles for Liposarcoma: Roles of Programmed Death Ligand 1, Microsatellite Instability, and PIK3CA.

BACKGROUND: Developing personalized strategies for cancer has shown good efficacies. METHODS: We assessed the molecular targets programmed death ligand 1 (PD-L1), microsatellite instability (MSI), and PIK3CA. Seventy-four patients with liposarcomas who underwent curative resection were assessed for PD-L1 expression in the tumor and tumor-infiltrating lymphocytes (TILs), mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6) by immunohistochemistry, MSI using polymerase chain reaction, and PIK3CA mutation/amplification using pyrosequencing and fluorescence in situ hybridization. RESULTS: Seventeen (23%) cases were TIL+ (≥1 + expression) and associated with longer 5-year overall survival than those with TIL- tumors (84.4 vs. 60.8%, p = 0.007). Six (35.3%) PD-L1+ tumors were detected only in TIL+ cases, with none detected in tumor cells. Two well-differentiated liposarcomas showed MSI, one low and one high with concurrent loss of MLH1, MSH6, and PMS2. PIK3CA mutation was detected in 7 (9.5%) [exon 9 (n = 4) and exon 20 (n = 3)] and only 1 Q546K mutation was a PD-L1+ tumor. PIK3CA copy number gain was detected in 18 (24.4%) and was associated with TIL+ tumors (p = 0.045). CONCLUSIONS: Our comprehensive immuno-molecular panel suggests that liposarcoma should be categorized based on the molecular genomic subtype for precision medicine.

Effect of water scarcity during thermal-humidity exposure on the mineral footprint of sheep.

OBJECTIVE: Combination of two stressors on alteration of mineral footprints in animals needs due attention to meet maximum production and welfare, particularly in grazing sheep. This study tested whether ewes (Ovis aries) exposed to water deprivation and thermal-humidity stressors had altered mineral footprints in their wool, serum, urine, and feces. METHODS: Nine ewes (age = 3 years; mean body weight = 41±3.5 kg) were divided among a control group with free access to water, and treatment groups with water deprivation lasting either 2 h (2hWD) or 3 h (3hWD) after feeding. Using a 3×3 Latin square design, animals were assigned to treatment groups for three sampling periods of 21 days each (n = 9). Blood was collected by jugular venipuncture. Wool was collected at the end of periods 2 and 3. Metabolic crates designed with metal grated floors were used for urine and feces collection. We measured sodium (Na), magnesium (Mg), phosphorus (P), chloride (Cl), calcium (Ca), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). RESULTS: The wool mineral levels did not differ between the treatment groups, although K was marginally lower (p = 0.10) in the 2hWD group. The serum and urine mineral levels did not differ between the treatments (p>0.05). Fecal K was significantly lower in the 2hWD group than in the other groups (p≤0.05). CONCLUSION: In conclusion, water deprivation and thermal-humidity exposure altered the excretion of K, but not of other minerals, in the wool, urine, feces, or serum of ewes. Thus, no additional mineral supplementation is needed for water deprived ewes during thermalhumidity exposure.

Inhibiting casein kinase 2 overcomes paclitaxel resistance in gastric cancer.

PURPOSE: Casein kinase (CK) 2 activation has been implicated in the proliferation of various tumor types and resistance to chemotherapy. We investigated the mechanistic basis for the association between CK2 activation and paclitaxel resistance in a gastric cancer (GC). EXPERIMENTAL DESIGN: CK2 expression was evaluated in 59 advanced GC patients treated with paclitaxel as the second-line therapy. The efficacy of a CK2 inhibitor, CX-4945, and paclitaxel was evaluated in GC cell lines and a xenograft model. RESULTS: Patients with high CK2 expression (29/59, 39%) showed lower disease control rates (47.7% vs. 72.3%, p = 0.017) and shorter progression-free survival (2.8 vs. 4.8 months, p = 0.009) than patients with low CK2 expression. CK2 protein expression was associated with sensitivity to paclitaxel in 49 GC cell lines. Combination therapy with CX-4945 and paclitaxel exerted synergistic antiproliferative effects and inhibited the downregulation of phosphatidylinositol 3-kinase/AKT signaling in SNU-1 cells. In the SNU-1 xenograft model, the combination treatment was significantly superior to either single agent, suppressing tumor growth without notable toxicities. CONCLUSIONS: These results demonstrated that CK2 activation was related to paclitaxel resistance and that CX-4945 in combination with paclitaxel could be used as a potential treatment for paclitaxel resistance in GC.

Design Optimization of Bulk Piezoelectric Acceleration Sensor for Enhanced Performance.

While seeking to achieve high performances of a bulk piezoelectric acceleration sensor, we investigated the behavior of the design variables of the sensor components and optimized the sensor design using a numerical simulation based on piezoelectric analysis and metamodeling. The optimized results demonstrated that there was an exponential dependency in the trade-off relation between two performance indicators, the electric voltage and the resonant frequency, as induced by the design characteristics of the sensor. Among the design variables, a decrease in the base height and epoxy thickness and an increase in the piezo element's inner diameter had a positive effect on two performances, while the head dimensions (diameter and height) exhibited the opposite effect on them. The optimal sensor designs are proposed within the valid range of resonant frequency (25-47.5 kHz). Our redesign of a commercial reference sensor improved the resonant frequency by 13.2% and the electric voltage by 46.1%.

Changes of Microbial Diversity During Swine Manure Treatment Process.

We investigated microbial diversity in a manure storage tank (MST) storing untreated manure and an aeration tank (AT) during swine manure treatment process using the next-generation sequencing in order to find the aeration effect on microbial diversity. Proteobacteria were more abundant in the AT group than in the MST group and may include denitrifying bacteria contributing to nitrous oxide (N2O) emission or aerobic bacteria stimulated by oxygen. The opposite held true for the phyla Bacteroidetes and Firmicutes that may include anaerobic bacteria inhibited under aerobic conditions in the AT group.

Identification of capacitation inducers customized to sperm retrieved from inbred mouse epididymis.

Acquisition of sperm capacitation post-ejaculation into the female reproductive tract is an essential step in the fertilization process. Accordingly, during in vitro fertilization, successful fertilization requires the induction of capacitation in epididymis-retrieved sperm. To date, many candidate substances have been considered as capacitation inducers; however, there are no reports on the efficiency of inducing sperm capacitation among the diverse inducers. Therefore, we attempted to determine the inducer with the best capacitation in inbred mouse sperm by comparing the capacitation performance of a variety of inducers and the percentage of in vitro fertilization-generated zygotes. Calcium chloride, progesterone, bovine serum albumin (BSA), heparin, and lysophosphatidylcholine (Lyso-PC) were used as candidate capacitation inducers. Optimized concentrations of each inducer (2.7 mM calcium, 15 µM progesterone, 0.3% (w/v) BSA, 50 mM heparin, and 100 µM Lyso-PC) were determined based on the ratio of sperm showing an acrosome reaction using Coomassie G-250 blue staining. Calcium at 2.7 mM showed the strongest capacitation induction compared to the other inducers. In vitro fertilization was performed using sperm incubated in each inducer and the ratio of fertilized oocytes was determined. Calcium at 2.7 mM and 0.3% (w/v) BSA showed the highest fertilization rates compared to 15 µM progesterone, 50 mM heparin, and 100 µM Lyso-PC. From these results, we found that 2.7 mM calcium and 0.3% (w/v) BSA were the most effective sperm capacitation inducers of mouse sperm for in vitro fertilization.

Integrins functioning in uterine endometrial stromal and epithelial cells in estrus.

Here, as a basic study in the construction of a non-cellular niche that supports artificial organization of three-dimensional endometrial tissue, we defined the types of integrin heterodimers that are expressed transcriptionally, translationally and functionally in endometrial stromal (ES) and endometrial epithelial (EE) cells isolated from the mouse uterus in estrus. Gene and protein expression of integrin subunits were analyzed at the transcriptional and translational level by real-time PCR and fluorescent immunoassay, respectively. Moreover, the functionality of integrin heterodimers was confirmed by attachment and antibody inhibition assays. Itga2, Itga5, Itga6, Itga9, Itgav, Itgb1, Itgb3 and Itgb5 in ES cells, and Itga2, Itga5, Itga6, Itga7, Itga9, Itgav, Itgb1, Itgb3, Itgb4, Itgb5 and Itga6 and in EE cells showed significantly higher transcriptional levels than the other integrin subunits. Furthermore, translational expression of the total integrin α and ß subunit genes that showed increased transcription was determined in ES and EE cells. ES cells showed significantly increased adhesion to collagen I, fibronectin and vitronectin, and functional blocking of integrin α2, α5 or αV significantly inhibited adhesion to these molecules. Moreover, EE cells showed significantly increased adhesion to collagen I, fibronectin, laminin and vitronectin, and functional blocking of integrin α2, α5, α6 or αV significantly inhibited adhesion to these molecules. Accordingly, we confirmed that integrin α2ß1, α5ß1, αVß1, αVß3 and/or αVß5, and integrin α2ß1, α5ß1, α6ß1 and/or α6ß4, αVß1, αVß3 and/or αVß5, actively function on the surface of ES and EE cells from mouse uterus in estrus phase, respectively.

Delivery of episomal vectors into primary cells by means of commercial transfection reagents.

Although episomal vectors are commonly transported into cells by electroporation, a number of electroporation-derived problems have led to the search for alternative transfection protocols, such as the use of transfection reagents, which are inexpensive and easy to handle. Polyplex-mediated transport of episomal vectors into the cytoplasm has been conducted successfully in immortalized cell lines, but no report exists of successful transfection of primary cells using this method. Accordingly, we sought to optimize the conditions for polyplex-mediated transfection for effective delivery of episomal vectors into the cytoplasm of primary mouse embryonic fibroblasts. Episomal vectors were complexed with the commercially available transfection reagents Lipofectamine 2000, FuGEND HD and jetPEI. The ratio of transfection reagent to episomal vectors was varied, and the subsequent transfection efficiency and cytotoxicity of the complexes were analyzed using flow cytometry and trypan blue exclusion assay, respectively. No cytotoxicity and the highest transfection yield were observed when the ratio of transfection reagent to episomal vector was 4 (v/wt) in the cases of Lipofectamine 2000 and FuGENE HD, and 2 in the case of jetPEI. Of the three transfection reagents tested, jetPEI showed the highest transfection efficiency without any cytotoxicity. Thus, we confirmed that the transfection reagent jetPEI could be used to effectively deliver episomal vectors into primary cells without electroporation.

PTEN deficiency as a predictive biomarker of resistance to HER2-targeted therapy in advanced gastric cancer.

BACKGROUND: To investigate the role of the phosphoinositide 3-kinase (PI3K) pathway activation in human epidermal growth factor receptor 2 (HER2)-targeted therapy. METHODS: We evaluated the predictive roles of PI3K, catalytic alpha (PIK3CA), and phosphatase and tensin homolog (PTEN) in HER2-based therapy (either trastuzumab or lapatinib). PTEN expression and PIK3CA mutation were analyzed using immunohistochemistry and pyrosequencing. RESULTS: Forty-eight patients received trastuzumab (n = 39) or lapatinib (n = 9) combination chemotherapy. PTEN loss was found in 47.9% (n = 23), but no PIK3CA mutations were identified. Twenty-six (54.1%) patients responded to HER2-based therapy, without a significant difference between patients with PTEN loss and those without (52.2 vs. 56.0%). Among the patients with responsive disease, time to best response did not differ by PTEN status, but the duration of response was significantly shorter for patients with PTEN loss (median 4.2 vs. 6.1 months, p = 0.04). In addition, patients with PTEN loss had a significantly shorter progression-free survival time (median 4.9 vs. 7.3 months, p = 0.047). CONCLUSIONS: PTEN deficiency is an important predictive marker for early resistance to HER2 inhibitor treatment in gastric cancer patients. This finding may be useful for the development of drug combinations and identification of patients who need a modified treatment strategy.

Development of a chemically defined in vitro culture system to effectively stimulate the proliferation of adult human dermal fibroblasts.

Despite the fact that dermal fibroblasts are a practical model for research related to cell physiology and cell therapy, an in vitro culture system excluding serum, which complicates standardization and specificity and induces variability and unwanted effects, does not exist. We tried to establish a CDCS that supports effective proliferation of aHDFs. KDMEM supplemented with 5% (v/v) KSR, 12 ng/ml bFGF, 5 ng/ml EGF and 1 µg/ml hydrocortisone supported sufficient proliferation of aHDFs for 1 week. However, aHDF proliferation was decreased greatly after subculture. This problem could be overcome by culturing aHDFs in CDCM in culture plates coated with 10 µg/ml FN. Long-term culture of aHDFs was achieved using CDCM and FN-coated culture plates for 7 weeks. The optimized CDCS increased the proliferation of aHDFs significantly, without any increase in the senescence rate or alteration in morphology of aHDFs, despite long-term culture. In conclusion, we established a CDCS that improved proliferation of aHDFs while inhibiting cellular senescence. The CDCS will contribute to advances in various future research related to clinical skin regeneration.

High KLF4 level in normal tissue predicts poor survival in colorectal cancer patients.

BACKGROUND: Krüppel-like factor 4 (KLF4) is involved in many important cellular processes such as growth, development, differentiation, proliferation, and apoptosis. The purpose of this study was to determine the significance of KLF4 in both tumors and normal tissues of patients with colorectal cancer (CRC). METHODS: Between January 2003 and June 2005, 125 patients with CRC receiving treatment at the Yonsei Cancer Center were selected. We examined the mRNA level of the KLF4 gene in primary CRC specimens and matched normal colon tissues using real-time RT-PCR. Correlation of survival with clinicopathological parameters, including KLF4 level, was investigated with univariate and multivariate analyses. RESULTS: CRC tissue had a significantly lower KLF4 level when compared with matched normal tissues (KLF4 in tumors: 2007 ± 1531 copies/µl, KLF4 in normal tissues: 6586 ± 2834 copies/µl; P < 0.0001). However, there was a correlation between the KLF4 level in tumors and normal tissues. Patients with a high KLF4 level in matched normal tissues were more likely than those with a low KLF4 level to develop recurrence and had poorer overall survival (P = 0.005). Therefore, the KLF4 level in the normal tissue of individuals was associated with prognosis of individuals. CONCLUSIONS: Our data suggest that KLF4 mRNA expression level in normal tissues and tumors may be a useful prognostic marker in patients with CRC.

Long-term efficacy of a triptorelin 3-month depot in girls with central precocious puberty.

PURPOSE: Three-month gonadotropin-releasing hormone agonists (GnRHas) are expected to achieve better compliance in patients with central precocious puberty (CPP) compared to the monthly formulation. However, 1-month depot remains the dominant choice for conventional treatment worldwide. Our study aimed to investigate the long-term efficacy of a 3-month GnRHa for CPP treatment. METHODS: In this retrospective study, 69 Korean girls with CPP were prescribed either triptorelin pamoate (TP) 3-month depot (n=29) or triptorelin acetate (TA) 1-month depot (n=40) and were followed for 1 year after the end of treatment. Auxological, radiological, and biochemical data were collected every 6 months. RESULTS: Baseline characteristics were similar between the 2 groups. In the TP 3-month depot group, 27 of 29 patients (93.1%) exhibited suppressed luteinizing hormone level (below 2.5 IU/L) after 6 months of treatment, and this suppression level was reserved until the final injection. The degree of bone age advancement in the TP 3-month depot group decreased from 1.8±0.4 years at the start of treatment to 0.6±0.5 years at 1-year posttreatment. The gain in predicted adult height (PAH) 1 year after the end of treatment was similar between the TP 3-month and TA 1-month depot groups (5.2±3.1 and 5.3±2.4 cm, respectively; p=0.875). CONCLUSION: A 3-month depot of triptorelin effectively inhibited gonadal and sex hormones, suppressed bone maturation, and increased PAH. For patient convenience, we suggest a 3-month GnRHa regimen as a promising CPP treatment option.

Effectiveness of the triptorelin stimulation test compared with the classic gonadotropin-releasing hormone stimulation test in diagnosing central precocious puberty in girls.

PURPOSE: The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for diagnosing central precocious puberty (CPP). Gonadorelin (Relefact) is used for the test but is not always readily available; triptorelin is used as an alternative. The purpose of this study was to evaluate the diagnostic validity of the triptorelin test compared with the GnRH test in the diagnosis of CPP in girls. METHODS: This retrospective study included 100 girls with premature thelarche (PT) who underwent a hypothalamic-pituitary-gonadal axis evaluation. In the overall group, 50 girls were tested with intravenous gonadorelin (Relefact) and 50 girls were tested with subcutaneous triptorelin acetate (Decapeptyl). Luteinizing hormone (LH) and follicle-stimulating hormone levels were measured at baseline and 30, 45, 60, and 90 minutes after gonadorelin injection or 30, 60, 90, and 120 minutes after triptorelin injection. RESULTS: Clinical characteristics of age, height, weight, body mass index, and bone age were similar between the 2 groups. The highest LH level was reached 60 minutes after stimulation in both groups. Approximately 20% of the gonadorelin group and 24% of the triptorelin group were diagnosed with CPP (P=0.52). Among those diagnosed with CPP, the mean peak LH concentrations were 8.15 mIU/mL and 9.73 mIU/mL in the gonadorelin and triptorelin groups, respectively. CONCLUSION: The triptorelin test showed similar trends of LH elevation and diagnostic rate compared with the traditional GnRH test for diagnosing CPP. This suggests that the triptorelin test may be a valid alternative to the GnRH test for differentiating CPP from self-limiting PT. Our study also demonstrated that a triptorelin stimulation test for up to 120 minutes was sufficient to diagnose CPP.

Comparison of the incidence of postoperative nausea and vomiting between women undergoing open or robot-assisted thyroidectomy.

BACKGROUND: Open thyroidectomy is associated with a high incidence of postoperative nausea and vomiting (PONV) in up to 70 % of cases. Use of the recently introduced robot-assisted endoscopic thyroidectomy using a gasless transaxillary approach has been increasing because of its several advantages over open thyroidectomy. This study compared the incidence of PONV in the women who underwent open or robot-assisted thyroidectomy. METHODS: This prospective, double-blinded study enrolled 170 women 20-60 years of age who were scheduled for conventional open thyroidectomy (group O) or robot-assisted thyroidectomy (group R). A standard anesthetic technique, including sevoflurane and air in oxygen, was used. During a 0-24-h postoperative period, the presence and severity of PONV (nausea, retching/vomiting), severity of pain, need for rescue antiemetics, and the degree of patient satisfaction were evaluated. RESULTS: During the 0-6-h postoperative period, the incidence of PONV and mean pain score (40.0 vs. 51.8 %and 4.2 vs. 4.8 in groups R and O, respectively) were not significantly different. At 6-24 h postoperatively, the incidence of PONV (18.8 vs. 44.7 %), severe emesis (11.8 vs. 29.4 %) and mean pain score (2.8 vs. 3.8) were significantly lower in group R compared to group O, respectively. Overall, the incidence of PONV (42.4 vs. 63.5 %) and severe emesis (20.0 vs. 43.5 %) were significantly lower in group R compared to group O, respectively. The incidence of satisfied patients 6 and 24 h after the end of anesthesia (55.3 vs. 28.2 and 82.4 vs. 58.8 %) were significantly higher in group R compared to group O, respectively. CONCLUSIONS: Robotic thyroidectomy reduces the incidence and severity of PONV compared to open thyroidectomy during a 0-24-h postoperative period.

Peri-estrus activity and mounting behavior and its application to estrus detection in Hanwoo (Korea Native Cattle).

This study was conducted to investigate the change in activity and mounting behavior in Hanwoo (Korean Native Cattle) during the peri-estrus period and its application to estrus detection. A total of 20 Hanwoo cows were fitted with a neck-collar accelerometer device, which measured the location and acceleration of cow movements and recorded the number of instances of mounting behavior by the altitude data. The data were analyzed in three periods (24-, 6-, and 2-h periods). Blood samples were collected for 5 days after the prostaglandin F2α (PGF2α) injection, and the concentrations of estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone were determined by enzyme-linked immunosorbent assays. Activity and mounting behavior recorded over 2-h periods significantly increased as estrus approached and were more efficient at detecting estrus than over 24- and 6-h periods (p < 0.05). Endocrine patterns did not differ with the variation of individual cows during the peri-estrus period (p > 0.05). Activity was selected as the best predictor through stepwise discriminant analysis. However, activity alone is not enough to detect estrus. We suggest that a combination of activity and mounting behavior may improve estrus detection efficiency in Hanwoo. Further research is necessary to validate the findings on a larger sample size.

Assessment of Stress Levels in Lactating Cattle: Analyzing Cortisol Residues in Commercial Milk Products in Relation to the Temperature-Humidity Index.

Chronic stress in the dairy cattle industry has negative impacts on animal health, productivity, and welfare. It has been confirmed that cortisol transfers to milk and resists the high temperature during milk processing. This study evaluated the relationship between the milk cortisol concentration (MCC) in commercial milk products and the temperature-humidity index (THI) at the time of milk production. Eleven commercially produced pasteurized and sterilized milk products, purchased in Chuncheon, Korea, with production dates ranging from July to October 2021 were analyzed. The MCC was extracted using diethyl ether and analyzed using an enzyme immunoassay. The average THI values based on microclimate data provided by the Korea Meteorological Administration were 77 ± 0.8, 75 ± 1.4, 69 ± 1.4, and 58 ± 1.8, in July, August, September, and October, respectively. The average MCC levels were 211.9 ± 95.1, 173.5 ± 63.8, 109.6 ± 53.2, and 106.7 ± 33.7 pg/mL in July, August, September, and October, respectively. The MCC in July was higher than in August, September, and October (p < 0.05), while it was lower in September and October than in August (p < 0.05). Significant variations in the MCC were observed in commercial milk products across the four production months (p < 0.05), except for two milk products. Overall, monitoring the cortisol residue in commercial dairy milk products can be an alternative indicator of stress in dairy cattle of farms.

Measurement of greenhouse gas emissions from a dairy cattle barn in Korea.

Korea is currently developing country-specific emission factors to support the 2050 zero-carbon campaign. Dairy cattle represent one of the largest livestock industries in Korea, and the industry is estimated to continue increasing because of an increase in milk demand. However, country-specific emission factors for dairy cattle are currently only available for calculating methane (CH4) emissions from enteric fermentation. Two experiments were conducted to evaluate CH4 and nitrous oxide (N2O) fluxes from sawdust-bedded barn in dairy cow and steer, as well as dairy cattle manure composting lots. The greenhouse gas (GHG) fluxes were quantified using the open-chamber method and gas chromatography. CH4 fluxes from steer, dairy cow, and manure compost were 27.88 ± 5.84, 36.12 ± 10.85, and 259.44 ± 61.78 µg/head/s, respectively. N2O fluxes from steer, dairy cow, and manure compost were 14.04 ± 1.27, 4.11 ± 1.57, and 3.97 ± 1.08 µg/head/s, respectively. The result of this study can be used to construct country-specific data for GHG emissions from manure management. Thus, the application of mitigation strategies can be prioritized based on the GHG profile and targeted source.