• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.

• Journal of Korean society of Dental Hygiene
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• v.22 no.6
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• pp.485-494
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• 2022

Objectives: The COVID-19 outbreak has resulted in changes in the instructional methods used in kindergartens and daycare centers to prevent viral infections. This study aimed to investigate the changes in oral health care for children before and during COVID-19 and the perceptions of kindergarten and daycare center teachers about oral health care. Methods: The study subjects were 189 teachers of kindergartens and daycare centers in charge of children aged 3 to 5. The data for the analysis were collected through an online survey. Frequency analysis and the chi-squared test were used for statistical analysis. Results: Compared to before COVID-19, the frequency of tooth brushing after lunch, the number of oral health education and regular oral examinations, and the rate of childcare teachers' experiences with oral health education had decreased during COVID-19. In addition, educators in kindergarten and daycare centers responded that an oral health officer at a public health center was the most desirable oral health educator. Conclusions: During the COVID-19 pandemic, the oral health care of children in kindergartens and daycare centers has declined. Efforts are needed to restore it by educating people about oral hygiene care and oral health education, both at home and in kindergartens and daycare centers.

• Korea Journal of Hospital Management
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• v.27 no.4
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• pp.22-35
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• 2022

Purpose: Physician's occupational burnout has been a very important issue that can cause negative consequences not only for individual's physical and mental health, but also for patient's health and the overall national healthcare system. For the reason, this study confirmed how consultation length and the number of outpatients affect physician's occupational burnout in the medical environment. Methodology: In the study, the data of '2020 Korean Physician Survey' conducted by Korean Medical Association(KMA) was used for the analysis, and a total of 4,215 physicians were selected as study samples. The differences in the degree of occupational burnout according to the physicians' general characteristics were confirmed through uni-variate analysis, and also a regression analysis was conducted to confirm the effects of consultation length and the number of outpatients on physician's occupational burnout. Findings: As a result. the overall degree of physician's occupational burnout decreased(𝛽=-0.051, p<0.01) as the consultation length increased. Specifically, the physician's emotional exhaustion increased(𝛽=0.051, p<0.01), while the reduction of accomplishment decreased(𝛽=-0.131, p<0.001). Furthermore, the overall occupational burnout decreased(𝛽=-0.047, p<0.01) as a proportion of advice and education during the consultation increased, and it had an effect on the decrease in depersonalization(𝛽=-0.045, p<0.01) and the reduction of accomplishment(𝛽=-0.065, p<0.001). At last, as the number of outpatients increased, the overall occupational burnout increased(𝛽=0.041, p<0.05) with more emotional exhaustion(𝛽=0.095, p<0.001), depersonalization(𝛽=0.065, p<0.001), and less reduction of personal achievement(𝛽=-0.081, p<0.001). Practical implication: Consequently, it is necessary to prevent physician's occupational burnout by ensuring sufficient consultation length and providing a medical environment to treat an appropriate number of patients. Therefore, national policies should expand health insurance coverage and compensate medical fees for sufficient consultation length that both patients and physicians can satisfy. It will ultimately contribute to ensuring the patients' health and improving the quality of national healthcare services.

• Korean Journal of Veterinary Research
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• v.62 no.4
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• pp.29.1-29.7
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• 2022

Vaccination against Newcastle disease (ND) is the most effective means of controlling the disease, and these vaccines are commercialized only after their safety and effectiveness have been verified through tests that comply with Korean Standards of National Lot Release for Veterinary Biologics. This study investigated whether a relatively convenient and safe serological test can be used in place of the challenge test using highly virulent ND virus. Hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA) were considered positive of log₂ 2 or more and cutoff value of 200 or more, respectively, in both live and inactivated vaccines. However, when the antibody levels of the live and inactivated vaccines induced using the Ulster 2C, KBNP-C4152R2L, and K148/08 strains were compared, the antibody titers for inactivated vaccines were significantly higher than those for live vaccines in both the HI assay and ELISA. A strong positive correlation was observed between HI and ELISA antibody titers. The live vaccines corresponded to a survival rates of ≥ 80% and the inactivated vaccines corresponded to 100% survival rates. This study confirmed that standard efficacy tests can serve as serological tests, and can replace the challenge test and that the vaccine approval process can be improved.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.126-130
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• 2023

In response to environmental demands, pyrolysis is one of the practical methods for obtaining reusable oils from waste plastics. However, the waste plastic pyrolysis oils (WPPO) are consumed as low-grade fuel oil due to their impurities. Thus, this study focused on the upgrading method to obtain naphtha catalytic cracking feedstocks from WPPO by the hydroprocessing, including hydrotreating and hydrocracking reaction. Especially, various transition metal sulfides supported catalysts were investigated as hydrotreating and hydrocracking catalysts. The catalytic performance was evaluated with a 250 ml-batch reactor at 370~400 ℃ and 6.0 MPa H₂. Sulfur-, nitrogen-, and chlorine-compounds in WPPO were well eliminated with nickel-molybdenum/alumina catalysts. The NiMo/ZSM-5 catalyst has the highest naphtha yield.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.44-52
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• 2023

Objective : This study aimed to investigate the efficacy of transverse process (TP) hook system at the upper instrumented vertebra (UIV) for preventing screw pullout in adult spinal deformity surgery using the pedicle Hounsfield unit (HU) stratification based on K-means clustering. Methods : We retrospectively reviewed 74 patients who underwent deformity correction surgery between 2011 and 2020 and were followed up for >12 months. Pre- and post-operative data were used to determine the incidence of screw pullout, UIV TP hook implementation, vertebral body HU, pedicle HU, and patient outcomes. Data was then statistically analyzed for assessment of efficacy and risk prediction using stratified HU at UIV level alongside the effect of the TP hook system. Results : The screw pullout rate was 36.4% (27/74). Perioperative radiographic parameters were not significantly different between the pullout and non-pullout groups. The vertebral body HU and pedicle HU were significantly lower in the pullout group. K-means clustering stratified the vertebral body HU ≥205.3, <137.2, and pedicle HU ≥243.43, <156.03. The pullout rate significantly decreases in patients receiving the hook system when the pedicle HU was from ≥156.03 to < 243.43 (p<0.05), but the difference was not statistically significant in the vertebra HU stratified groups and when pedicle HU was ≥243.43 or <156.03. The postoperative clinical outcomes improved significantly with the implementation of the hook system. Conclusion : The UIV hook provides better clinical outcomes and can be considered a preventative strategy for screw-pullout in the certain pedicle HU range.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.90-94
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• 2023

Objective : Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. Methods : A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. Results : There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. Conclusion : In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.24-32
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• 2023

Objective : With the recent increase in mechanical thrombectomy (MT) for acute ischemic stroke (AIS), the role of neurosurgeons in AIS treatment has become increasingly important. This study aimed to assess the outcomes of patients with AIS treated by neurosurgeons and neurologists in the emergency room (ER) of a tertiary hospital in South Korea. Methods : From January 2020 to June 2021, 536 patients with AIS within 24 hours of symptom onset were admitted to our hospital via the ER. Based on the type of doctors who provided initial care for AIS in the ER, patients were divided into two groups : (a) neurosurgeon group (n=119, 22.2%) and (b) neurologist group (n=417, 77.8%). Results : Intravenous tissue plasminogen activator (tPA) was administered in 82 (15.3%) of 536 patients (n=17 [14.3%] in the neurosurgeon group and n=65 [15.6%] in the neurologist group). The door-to-tPA time was not significantly different between both groups (median, 53 minutes; interquartile range [IQR], 45-58 vs. median, 54 minutes; IQR, 46-74; p=0.372). MT was performed in 69 patients (12.9%) (n=25, 36.2% in the neurosurgeon group and n=44, 63.8% in the neurologist group). The neurosurgeon group achieved a shorter door-to-puncture time than the neurologist group (median, 115 minutes; IQR, 107-151 vs. median, 162 minutes; IQR, 117-189; p=0.049). Good clinical outcomes (3-month modified Rankin Scale 0-2) did not differ significantly between the two groups (96/119 [80.7%] vs. 322/417 [77.2%], p=0.454). Conclusion : The neurosurgeon group showed similar door-to-treatment time and clinical outcomes to the neurologist group in patients with AIS in the ER. This study suggests that neurosurgeons have comparable abilities to care for patients with AIS in the ER.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.72-81
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• 2023

Objective : Ischemia and hemorrhage of pituitary adenomas (PA) caused important clinical syndrome. However, the differences on clinical characteristics and surgical outcomes between these two kinds apoplexy were less reported. Methods : A retrospective analysis was made of patients with pituitary apoplexy between January 2013 and June 2018. Baseline and clinical characteristics before surgery were reviewed. All patients underwent transsphenoidal surgery and were followed up at least 1 year. Results : Total 67 cases (5.8%) among 1147 pituitary tumor patients were enrolled, which consisted of 28 (~2.4%) ischemic PA and 39 (~3.4%) hemorrhagic PA. There were more male patients in the ischemic group compared with hemorrhagic group (78.6% vs 53.8%, p=0.043). However, the mean age, tumor size and functional tumor ratio were significant higher in the hemorrhagic group. Headache was more common in ischemic PA (82.1%) than that of hemorrhagic PA (51.3%, p=0.011). Magnetic resonance imaging findings found that mucosal thickening and enhancement of the sphenoid sinus was observed in 15 ischemic PA patients (n=27, 55.6%), but none in patients with hemorrhagic PA (n=38, p<0.0001). It was worth noting that the rate of pre-surgical hypopituitarism in ischemic PA patients were seemed higher than that in hemorrhagic PA patients, but not significant. The two groups got a total tumor resection rate at 94.1% and 92.9%, independently. No significant difference on the operative time, blood loss in operation and complications in perioperative period was observed in two groups. After operation, cranial nerve symptoms recovered to normal at 81.8% of ischemic PA patients and 82.6% of hemorrhagic PA patients. Importantly, the incidence of postoperative hypopituitarism partially decreased in both groups, among which the rate of hypothyroidism in ischemic PA patients significantly decreased from 46.4% to 18.5% (p=0.044). Conclusion : Patients with ischemic PA presented different clinical characteristics to the hemorrhagic ones. Transsphenoidal surgery should be considered for the patients with neuro-ophthalmic deficits and might benefit for pituitary function recovery of the apoplectic adenoma patients, especially pituitary thyroid axis in ischemic PA patients.

• Journal of Korean Neurosurgical Society
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• v.66 no.2
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• pp.144-154
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• 2023

Objective : Stroke caused from large vessel occlusion (LVO) has emerged as the most common stroke subtype worldwide. Intravenous tissue plasminogen activator administration (IV-tPA) and additional intraarterial thrombectomy (IA-Tx) is regarded as standard treatment. In this study, the authors try to find the early recanalization rate of IV-tPA in LVO stroke patients. Methods : Total 300 patients undertook IA-Tx with confirmed anterior circulation LVO, were analyzed retrospectively. Brain computed tomography angiography (CTA) was the initial imaging study and acute stroke magnetic resonance angiography (MRA) followed after finished IV-tPA. Early recanalization rate was evaluated by acute stroke MRA within 2 hours after the IV-tPA. In 167 patients undertook IV-tPA only and 133 non-recanalized patients by IV-tPA, additional IA-Tx tried (IV-tPA + IA-Tx group). And 131 patients, non-recanalized by IV-tPA (IV-tPA group) additional IA-Tx recommend and tried according to the patient condition and compliance. Results : Early recanalization rate of LVO after IV-tPA was 12.0% (36/300). In recanalized patients, favorable outcome (modified Rankin Scale, 0-2) was 69.4% (25/36) while it was 32.1% (42/131, p<0.001) in non-recanalized patients. Among 133 patients, non-recanalized after intravenous recombinant tissue plasminogen activator and undertook additional IA-Tx, the clinical outcome was better than not undertaken additional IA-Tx (favorable outcome was 42.9% vs. 32.1%, p=0.046). Analysis according to the perfusion/diffusion (P/D)-mismatching or not, in patient with IV-tPA with IA-Tx (133 patients), favorable outcome was higher in P/D-mismatching patient (52/104; 50.0%) than P/D-matching patients (5/29; 17.2%; p=0.001). Which treatment tired, P/D-mismatching was favored in clinical outcome (iv-tPA only, p=0.008 and IV-tPA with IA-Tx, p=0.001). Conclusion : The P/D-mismatching influences on the recanalization and clinical outcomes of IV-tPA and IA-Tx. The authors would like to propose that we had better prepare IA-Tx when LVO is diagnosed on initial diagnostic imaging. Furthermore, if the patient shows P/D-mismatching on MRA after IV-tPA, additional IA-Tx improves treatment results and lessen the futile recanalization.