Feeding practice during infancy is associated with attention-deficit/hyperactivity disorder and autism spectrum disorder: a population-based study in South Korea.

Attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are representative neurodevelopmental disorders. Using a nationwide database, we aimed to investigate whether feeding practices in infancy (breastfeeding and the timing of supplementary food introduction) could impact ADHD or ASD development. We evaluated 1,173,448 children aged 4-6 months who were included in the National Screening Program for Infants and Children (NHSPIC) between 2008 and 2014. We observed individuals until 6-7 years of age. Data on feeding type (milk feeding: exclusive breastfeeding [EBF], partial breastfeeding [PBF], exclusive formula feeding [EFF] at 4-6 months of age; supplementary food introduction: < 6 or > 6 months of age) were obtained from the NHSPIC, and diagnoses were based on the International Classification of Diseases, Tenth Revision. In a generalized linear model, children who received EBF had significantly lower incidence of both ADHD (odds ratio [OR]: 0.77, 95% confidence interval [CI]: 0.72-0.82) and ASD (OR: 0.64, 95% CI: 0.60-0.67) than that of children who received EFF. PBF also had a significant protective effect on both ADHD (0.91; 0.85-0.98), and ASD (0.89; 0.83-0.95). The timing of supplementary food introduction was not associated with either ADHD or ASD, although there was an increased risk of ASD in the EFF infants who had supplementary food introduced at > 6 months of age.  Conclusion: Our study strengthens and supports the beneficial effect of breastfeeding on neurodevelopmental disorders in children. Breastfeeding should be encouraged and recommended to promote desirable neurodevelopmental outcomes. What is Known: • Breastfeeding is beneficial for the overall health of children, including neurodevelopmental outcomes and cognitive functions. What is New: • Breastfeeding, especially exclusive breastfeeding, was protective against neurodevelopmental disorders. • The effect of the timing of supplementary food introduction was limited.

Multiple variants of African swine fever virus circulating in Vietnam.

African swine fever (ASF) is a contagious and deadly viral disease affecting swine of all ages. ASF was first reported in Vietnam in February 2019, and it is now considered endemic in Vietnam. In this study, 122 ASF-positive samples collected from domestic pigs in 28 different provinces of northern, central, and southern Vietnam during outbreaks in 2019-2021 were genetically characterized. The findings confirmed that all ASF virus (ASFV) strains circulating in Vietnam belonged to p72 genotype II, p54 genotype II, CD2v serogroup 8, and CVR gene variant type I. However, further analysis based on the tandem repeat sequences located between I73R and I329L genes revealed that there were three different variants of ASFV, IGR I, II, and III, circulating in the domestic pig population in Vietnam. The IGR II variants were the most prevalent (117/122 strains) and were detected in pigs in all of the provinces tested, followed by IGR III (4/122 strains) and IGR I (1/122 strains). This study confirms for the first time the presence of IGR III variants in Vietnam.

Traction Performance Evaluation of the Electric All-Wheel-Drive Tractor.

This study aims to design, develop, and evaluate the traction performance of an electric all-wheel-drive (AWD) tractor based on the power transmission and electric systems. The power transmission system includes the electric motor, helical gear reducer, planetary gear reducer, and tires. The electric system consists of a battery pack and charging system. An engine-generator and charger are installed to supply electric energy in emergency situations. The load measurement system consists of analog (current) and digital (battery voltage and rotational speed of the electric motor) components using a controller area network (CAN) bus. A traction test of the electric AWD tractor was performed towing a test vehicle. The output torques of the tractor motors during the traction test were calculated using the current and torque curves provided by the motor manufacturer. The agricultural work performance is verified by comparing the torque and rpm (T-N) curve of the motor with the reduction ratio applied. The traction is calculated using torque and specifications of the wheel, and traction performance is evaluated using tractive efficiency (TE) and dynamic ratio (DR). The results suggest a direction for the improvement of the electric drive system in agricultural research by comparison with the conventional tractor through the analysis of the agricultural performance and traction performance of the electric AWD tractor.

Analysis of the Effect of Tillage Depth on the Working Performance of Tractor-Moldboard Plow System under Various Field Environments.

The purpose of this study was to analyze the tillage depth effect on the tractor-moldboard plow systems in various soil environments and tillage depths using a field load measurement system. A field load measurement system can measure the engine load, draft force, travel speed, wheel axle load, and tillage depth in real-time. In addition, measurement tests of soil properties in the soil layer were preceded to analyze the effect of field environments. The presented results show that moldboard plow at the same tillage depth had a wide range of influences on the tractor's working load and performance under various environments. As the draft force due to soil-tool interaction occurred in the range of 5.6-17.7 kN depending on the field environment, the overall mean engine torque and rear axle torque were up to 2.14 times and 1.67 times higher in hard and clayey soil, respectively, than in soft soil environments. In addition, the results showed tractive efficiency of 0.56-0.73 and were analyzed to have a lugging ability of 67.8% with a 44% maximum torque rise. The engine power requirement in hardpan was similar within 3.6-9.6%, but the power demand of the rear axle differed by up to 18.4%.

Molecular profile of African swine fever virus (ASFV) circulating in Vietnam during 2019-2020 outbreaks.

African swine fever (ASF) is a highly infectious disease of pigs caused by African swine fever virus (ASFV). In order to identify potential genetic variations among ASFV strains circulating in Vietnam, 26 ASFV isolates from organs and blood samples collected from domestic pigs from 23 different provinces of northern, central and southern Vietnam during 2019-2020 ASF outbreaks were genetically characterized. Nucleotide sequences were determined for a portion of the B646L (p72) gene, the complete E183L (p54) gene, the variable region of EP402R (CD2v), the central variable region (CVR) of pB602L, and a tandem repeat sequence (TRS) between the I73R and I329L genes. Analysis of the partial B646L (p72) and EP402R (CD2v) gene sequences and the full-length E183L (p54) gene sequence showed that all 26 ASFV isolates belonged to genotype II and serotype VIII and that they were identical to the strain Georgia/2007/1 and all ASFV strains sequenced in China. The TRS between the I73R and I329L genes contained a 10-nucleotide insertion that was observed in the Chinese ASFV strain CN201801 isolated from domestic pigs in 2018, but not in the Georgia/2007/1 and China/Jilin/2018/boar strains isolated from wild boar in China. This is the first intra-epidemic genome analysis reported for the ASFV strains circulating in Vietnam.

Estimation of Axle Torque for an Agricultural Tractor Using an Artificial Neural Network.

The objective of this study was to develop a model to estimate the axle torque (AT) of a tractor using an artificial neural network (ANN) based on a relatively low-cost sensor. ANN has proven to be useful in the case of nonlinear analysis, and it can be applied to consider nonlinear variables such as soil characteristics, unlike studies that only consider tractor major parameters, thus model performance and its implementation can be extended to a wider range. In this study, ANN-based models were compared with multiple linear regression (MLR)-based models for performance verification. The main input data were tractor engine parameters, major tractor parameters, and soil physical properties. Data of soil physical properties (i.e., soil moisture content and cone index) and major tractor parameters (i.e., engine torque, engine speed, specific fuel consumption, travel speed, tillage depth, and slip ratio) were collected during a tractor field experiment in four Korean paddy fields. The collected soil physical properties and major tractor parameter data were used to estimate the AT of the tractor by the MLR- and ANN-based models: 250 data points were used for developing and training the model were used, the 50 remaining data points were used to test the model estimation. The AT estimated with the developed MLR- and ANN-based models showed agreement with actual measured AT, with the R2 value ranging from 0.825 to 0.851 and from 0.857 to 0.904, respectively. These results suggest that the developed models are reliable in estimating tractor AT, while the ANN-based model showed better performance than the MLR-based model. This study can provide useful results as a simple method using ANNs based on relatively inexpensive sensors that can replace the existing complex tractor AT measurement method is emphasized.

Weakly Supervised Crop Area Segmentation for an Autonomous Combine Harvester.

Machine vision with deep learning is a promising type of automatic visual perception for detecting and segmenting an object effectively; however, the scarcity of labelled datasets in agricultural fields prevents the application of deep learning to agriculture. For this reason, this study proposes weakly supervised crop area segmentation (WSCAS) to identify the uncut crop area efficiently for path guidance. Weakly supervised learning has advantage for training models because it entails less laborious annotation. The proposed method trains the classification model using area-specific images so that the target area can be segmented from the input image based on implicitly learned localization. This way makes the model implementation easy even with a small data scale. The performance of the proposed method was evaluated using recorded video frames that were then compared with previous deep-learning-based segmentation methods. The results showed that the proposed method can be conducted with the lowest inference time and that the crop area can be localized with an intersection over union of approximately 0.94. Additionally, the uncut crop edge could be detected for practical use based on the segmentation results with post-image processing such as with a Canny edge detector and Hough transformation. The proposed method showed the significant ability of using automatic perception in agricultural navigation to infer the crop area with real-time level speed and have localization comparable to existing semantic segmentation methods. It is expected that our method will be used as essential tool for the automatic path guidance system of a combine harvester.

Cryopreserved cord blood mononuclear cells in DMSO are healthy for at least 6 hours after thawing.

PURPOSES: We investigated the impact of time, storage temperature, and dimethyl sulfoxide (DMSO) on the viability of HSCs, as well as on apoptotic changes in thawed CB. MATERIALS & METHODS: Thirteen units of cryopreserved CB were thawed and half of each sample was stored at room temperature (RT) and the other half at 4℃, without removing or diluting DMSO. Flow cytometry was employed to enumerate total nucleated cells (TNCs), total/viable CD34+ cells, and early/late apoptotic cells using anti-CD45, anti-CD34, and annexin V(AnV), 7-amino actinomycin D(AAD) staining, respectively. RESULTS: In CBs stored at 4℃ there were no significant changes in numbers of TNCs, total/viable CD34+ cells, or early/late apoptotic cell up to 48 h. However, the numbers of these cells declined significantly at RT. Total and viable CD34+ cell counts did not change for up to 6 h at RT but viable CD34+ cells decreased significantly after 24 h, and total CD34+ cell after 48 h. Early and late apoptosis tended to increase with time at RT, and numbers of viable CD34+ cells and early apoptotic cells differed significantly between RT and 4℃ after 48 h. CONCLUSIONS: There are no significant changes of viability and apoptosis in CBs stored in DMSO at 4℃ until 48 h after thawing, while at RT, there are no significant changes of total/viable CD34+ cell counts or in the proportion of apoptotic cells for at least 6 h after thawing.

Analysis of Tillage Depth and Gear Selection for Mechanical Load and Fuel Efficiency of an Agricultural Tractor Using an Agricultural Field Measuring System.

This study was conducted to analyze the effects of tillage depth and gear selection on the mechanical load and fuel efficiency of an agricultural tractor during plow tillage. In order to analyze these effects, we developed an agricultural field measuring system consisting of a load measurement part (wheel torque meter, proximity sensor, and real-time kinematic (RTK) global positioning system (GPS)) and a tillage depth measurement part (linear potentiometer and inclinometer). Field tests were carried out using moldboard plows with a maximum tillage depth of 20 cm and three gear selections (M2H, M3L, and M3H) in a rice stubble paddy field for plow tillage. The average travel speed and slip ratio had the lowest M2H and the highest M3L. M3H had the highest theoretical speed, but the travel speed was 0.13 km/h lower than M3L due to the reduction in the axle rotational speed at deep tillage depth. Regarding engine load, the higher the gear, the greater the torque and the lower the axle rotation speed. The front axle load was not significantly affected by the tillage depth as compared to other mechanical parts, except for the M3H gear. The rear axle load generated about twice the torque of the front wheel and overall, it tended to show a higher average rear axle torque at higher gear selection. The rear axle load and fuel rate were found to be most affected by the combination of the tillage depth and gear selection combination. Overall, field test results show that the M3H had the highest fuel efficiency and a high working speed while overcoming high loads at the same tillage depth. In conclusion, M3H is the most suitable gear stage for plow cultivation, and the higher the gear stage and the deeper the tillage depth during plowing, the higher the fuel efficiency. The results of this study will be useful for analyzing mechanical load and fuel efficiency during farm operations. In a future study, we will conduct load analysis studies in other farming operations that consider various soil mechanics factors as well as tillage depths and gear selections.

Development of a Real-Time Tillage Depth Measurement System for Agricultural Tractors: Application to the Effect Analysis of Tillage Depth on Draft Force during Plow Tillage.

The objectives of this study were to develop a real-time tillage depth measurement system for agricultural tractor performance analysis and then to validate these configured systems through soil non-penetration tests and field experiment during plow tillage. The real-time tillage depth measurement system was developed by using a sensor fusion method, consisting of a linear potentiometer, inclinometer, and optical distance sensor to measure the vertical penetration depth of the attached implement. In addition, a draft force measurement system was developed using six-component load cells, and an accuracy of 98.9% was verified through a static load test. As a result of the soil non-penetration tests, it was confirmed that sensor fusion type A, consisting of a linear potentiometer and inclinometer, was 6.34-11.76% more accurate than sensor fusion type B, consisting of an optical distance sensor and inclinometer. Therefore, sensor fusion type A was used during field testing as it was found to be more suitable for use in severe working environments. To verify the accuracy of the real-time tillage depth measurement system, a linear regression analysis was performed between the measured draft and the predicted values calculated using the American Society of Agricultural and Biological Engineers (ASABE) standards-based equation. Experimental data such as traveling speed and draft force showed that it was significantly affected by tillage depth, and the coefficient of determination value at M3-Low was 0.847, which is relatively higher than M3-High. In addition, the regression analysis of the integrated data showed an R-square value of 0.715, which is an improvement compared to the accuracy of the ASABE standard prediction formula. In conclusion, the effect of tillage depth on draft force of agricultural tractors during plow tillage was analyzed by the simultaneous operation of the proposed real-time tillage depth measurement system and draft force measurement system. In addition, system accuracy is higher than the predicted accuracy of ±40% based on the ASABE standard equation, which is considered to be useful for various agricultural machinery research fields. In future studies, real-time tillage depth measurement systems can be used in tractor power train design and to ensure component reliability, in accordance with agricultural working conditions, by predicting draft force and axle loads depending on the tillage depth during tillage operations.

Simulation of Design Factors of a Clutch Pack for Power-Shift Transmission for an Agricultural Tractor.

The objective of this study is the simulation of the most affected design factors and variables of the clutch pack for the power-shift transmission (PST) of a tractor based measured data. The simulation model, the mathematical model of sliding velocity, a moment of inertia, and clutch engagement pressure of clutch pack were developed using the powertrain and configurations of the real PST tractor. In this study, the sensor fusion method was used to precisely measure the proportional valve pressure by test bench, which was applied to the simulation model. The clutch engagement times were found 1.20 s at all temperatures for determined factors. The engagement pressures have a significant difference at various temperatures (25 to 100 °C) of the hydraulic oils after the 1.20 s but the most affected factors were satisfied with the simulation conditions that ensure the clutch engagement on time. Finally, this sensor fusion method is believed to be helpful in realizing precision agriculture through minimization of power loss and maximum energy efficiency of tractors.

Retraction notice to "Polo-like kinase 2 gene expression is regulated by the orphan nuclear receptor estrogen receptor-related receptor gamma (ERRγ)" [Biochem. Biophys. Res. Commun. 362 (1) (2007) 107-113].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The authors have indicated that Fig. 1D data originated from another source not specified in the article. They also indicated image duplication in Fig. 1A and B. The authors of this article would like to apologize to all affected parties.

Percutaneous Transcholecystic Removal of Common Bile Duct Stones: Case Series in 114 Patients.

Purpose To evaluate the safety and effectiveness of percutaneous transcholecystic removal of common bile duct (CBD) stones in 114 patients. Materials and Methods This retrospective study was approved by the institutional review board. From September 2011 through February 2017, 114 consecutive patients (68 men, 46 women; mean age, 73 years) underwent percutaneous transcholecystic removal of CBD stones. All patients had acute cholangitis or cholecystitis. Stones were extracted through a 12-F sheath by using a Wittich nitinol stone basket uder fluoroscopic guidance. Technical success rates, complications, and long-term follow-up were evaluated. Results Technical success was achieved in 96 of 114 (84.2%) patients. In 18 patients, stone removal was unsuccessful due to failure of cystic duct cannulation (n = 11), proximal migration of the CBD stone (n = 3), multiple CBD stones (n = 3), and low insertion of the cystic duct (n = 1). No major procedure-related complications were seen. During the mean follow-up of 644 days (range, 11-2206 days), CBD stones recurred in 12 patients after a mean of 884 days (range, 439-1799 days) after the procedure. Conclusion Percutaneous transcholecystic removal of common bile duct stones seems to be a safe and effective method. © RSNA, 2018 Online supplemental material is available for this article . See also the editorial by vanSonnenberg and Panchanathan in this issue.

Smart device usage in early childhood is differentially associated with fine motor and language development.

AIM: We evaluated the relationships between the use of smart devices, such as smartphones and tablet computers, and the development levels and language scores in young children. METHODS: A cross-sectional analysis with 117 children aged three to five years was conducted. The participants were recruited from kindergartens in South Korea between November 2015 and April 2016. Parental questionnaires to assess smart device usage status by children, developmental screening test and receptive-expressive language scale were administered; metrics included smart device usage frequency and usage time, appropriate smart device usage level, developmental levels and language scores. RESULTS: Smart device usage frequency was significantly positively correlated with fine motor skill development [Spearman's correlation coefficient (rs ) = 0.426] in three-year-old children. Appropriate smart device usage level was also positively correlated with social development (rs  = 0.466). However, smart device usage time was significantly negatively correlated with expressive language months (rs  = -0.481). There were no such correlations in children aged four to five years. For the subcategories of appropriate usage level, the suitability of social relationship was significantly positively correlated with social development in three-year-old children (rs  = 0.474). CONCLUSION: In three-year-old children, smart device usage was positively correlated with fine motor development and negatively correlated with language development.

Correlation of Clinical and Histopathologic Parameters with Ultrasonographic Grades in Pediatric Non-Alcoholic Fatty Liver Disease.

BACKGROUND: Liver biopsy is the gold standard for diagnosing non-alcoholic steatohepatitis (NASH), but liver biopsy in children is not available in many institutes and many parents are reluctant to agree with the procedure. We investigated the correlation of clinical and pathologic parameters with the severity of non-alcoholic fatty liver disease (NAFLD) in pediatric patients using ultrasonographic examination methods and measured the prevalence of fatty pancreas in pediatric NAFLD. METHODS: Liver biopsy and abdominal ultrasound (US) examinations were performed in 58 children (42 boys, 16 girls; mean age, 12 years; age range, 4-19 years) between March 2006 and August 2017. Fatty liver and fatty pancreas were evaluated by two independent radiologists using US according to 4- and 3-point scales, respectively. We then analyzed the correlations of clinical, laboratory, and histopathologic parameters with the ultrasonographic grade of steatosis. RESULTS: Forty-two children showed simple steatosis (NAFLD activity score [NAS] ≤ 5) while 16 showed NASH (NAS > 5). Higher body mass index (BMI) percentile, waist circumference, hematocrit, insulin resistance, and lower insulin sensitivity index were significantly positively correlated with the grade of fatty liver. NAFLD activity score, amount of steatosis, and fibrosis significantly worsened as the fatty liver grade increased. Higher BMI, lower insulin sensitivity index, and boy were significantly positively correlated with the fatty pancreas grade. CONCLUSION: Altogether, ultrasonographic severity of fatty liver shows good correlation with that of clinical parameters and hepatic pathology.

Estimation of functional components of Chinese cabbage leaves grown in a plant factory using diffuse reflectance spectroscopy.

BACKGROUND: In recent years, protected crop production using plant factories to produce high-value crops with greater functional components has become more popular in many countries. The quantification of the components, however, is mainly conducted by laboratory analyses, which are both time- and labor-consuming. The present study aimed to investigate the potential of a non-destructive diffuse reflectance spectroscopy technique for estimating functional components (i.e. glucosinolates, amino acids, sugars and carotenoids) in the leaves of Chinese cabbage grown in a plant factory. RESULTS: From the overall analysis, better estimations were obtained using the partial least square regression procedure. The important wavelengths for each functional component were identified mainly in the ultraviolet-visible regions. Identified wavelengths were 317, 390, 888 and 940 nm for sugars; 520 and 960 nm for amino acids; 385, 860 and 945 nm for glucosinolates; and 454, 472 and 530 nm for carotenoids. CONCLUSION: Optical reflectance spectroscopy shows potential as a tool for the estimation of functional components in the leaves of Chinese cabbage. The results of the present study provide useful information for the design and application of sensors with respect to on-site quantification of the functional components. © 2018 Society of Chemical Industry.

Investigation of Clinical and Pathological Relationships between Adult- and Pediatric-type NASH in Korean Children.

BACKGROUND: Histologically, nonalcoholic steatohepatitis (NASH) is categorized into adult-type (type 1) and pediatric-type (type 2). The origination of the histological difference between the two types and how they differ clinically remain uncertain. We aimed to understand the incidence and clinical characteristics of the two types of NASH in Korean children, and to investigate the association between their pathological type and clinical characteristics, using anthropometric and laboratory data. METHODS: In 38 children with confirmed NASH, we investigated hepatic pathological findings, and correlating factors between pathological type and laboratory and anthropometric data (weight percentile, body mass index (BMI) z-score, and blood pressure percentile). Adult-type NASH was noted in 21 patients and pediatric-type in 17 patients. RESULTS: Age, sex, BMI, transaminase levels, and insulin resistance were not significantly different between the two groups. Triglyceride (TG) levels were higher in adult-type NASH (P = 0.033). Hematocrit and albumin levels were lower in adult-type NASH (P = 0.016 and 0.013, respectively). Hepatic fibrosis was more common in pediatric-type. The fibrosis scores in patients with adult-type were mostly 0 and 1, whereas the score was 3 in patients with pediatric-type (P = 0.024, 0.004, and < 0.010, respectively). Anthropometric data, liver function, and insulin resistance scores did not differ between the two pathological NASH types. TG, hematocrit, and albumin may be potential factors to predict pathological types. Fibrosis was observed more frequently in pediatric-type NASH. CONCLUSION: Monitoring children with pediatric-type NASH for progression to fibrosis or cirrhosis is recommended.

Serial Changes of Cytokines in Children with Cerebral Palsy Who Received Intravenous Granulocyte-colony Stimulating Factor Followed by Autologous Mobilized Peripheral Blood Mononuclear Cells.

BACKGROUND: This study was performed to assess serial cytokine changes and their clinical impact in children with cerebral palsy (CP) who received granulocyte-colony stimulating factor (G-CSF) followed by infusion of autologous mobilized peripheral blood mononuclear cells (mPBMCs). METHODS: Peripheral blood (PB) samples were collected from 16 CP children at enrollment, and 1 month and 7 months after G-CSF infusion as well as at the end of the study. Cytokine levels were measured by enzyme-linked immunosorbent assays with plasma samples. RESULTS: There were no significant differences in cytokine levels between the mPBMC and placebo groups over 6 months. However, when clinical responders and non-responders were compared, interleukin (IL)-6 (P = 0.050) as well as G-CSF (P = 0.010) were higher in the responders than the non-responders at 1 month, while brain-derived neurotrophic factor (BDNF) (P = 0.030) and insulin-like growth factor (IGF)-1 (P = 0.001) were lower. In addition, BDNF was higher at baseline in the responders than the non-responders (P = 0.030). CONCLUSION: The changes of G-CSF itself, as well as G-CSF-induced cytokines such as IL-6, may be associated with the clinical improvement of neurologic functions. The G-CSF-induced changes of IL-6, BDNF and IGF-1, and BDNF levels before treatment, could be used as prognostic factors in G-CSF trials in CP children.

Positive Effect of Baby-Friendly Hospital Initiatives on Improving Mothers' Intention for Successful Breastfeeding in Korea.

BACKGROUND: In Korea, the breastfeeding (BF) rate of infants aged 6 months or more is drastically decreasing, and this phenomenon is particularly worrisome for the future health of the population. The present study aimed to identify an antenatal strategy for initiation and continuation of human BF, and to identify how Baby-Friendly Hospitals (BFHs) may positively influence the intention to breastfeed. METHODS: A total of 414 pregnant Korean antenatal women were surveyed using questionnaires to determine current knowledge of the benefits of human breast milk, whether they planned to breastfeed after delivery, to continue BF after reinstatement in the workforce, are willing to abide by rooming-in care for infants, and plan to give birth at BFHs. RESULTS: We found that planning room-in care, greater awareness of BF benefits for infant and mother, participation in antenatal education programs, and provision of BF facilities in the workplace were positively associated with plans for exclusive breastfeeding (EBF) and longer BF duration. The mothers who planned to give birth at BFHs also desired to breastfeed immediately after birth, implement in-room care, continue BF at their workplace, participate in antenatal BF educational programs, and were more aware of the benefits of BF. CONCLUSION: If the beneficial effects of BFHs were well known to individuals, these would enhance the success rate of BF in Korea. Antenatal education and consequent acquisition of better knowledge of the benefits of BF are important for increasing the rate of BF practices.

A Single Center Analysis of the Positivity of Hepatitis B Antibody after Neonatal Vaccination Program in Korea.

The antibody to hepatitis B surface antigen (anti-HBs) seropositivity rate after 3 doses of hepatitis B virus (HBV) vaccination during infancy period is known to be higher than 90%. However, a considerable number of vaccines do not form protective anti-HBs or chronologic decrease of anti-HBs. We retrospectively collected data of HBV serologic test results in 20,738 individuals from 2000 to 2015. After exclusion criteria were applied, 19,072 individuals were included. We analyzed the anti-HBs seropositivity rate, anti-HBs disappearance rate, anti-HBs positive seroconversion rate after receiving a booster vaccine, and the difference in anti-HBs positivity between the 2 groups; group A (born before 2005, while both recombinant vaccines and plasma-derived vaccines were used) and group B (born after 2005, when only recombinant vaccines were used by national regulation). The anti-HBs seropositivity rate was 55.8%, but there was a significant difference in the rate of seropositivity for anti-HBs between the group A and B (53.0% vs. 78.1%, P < 0.001). There was no significant age-adjusted difference in the mean seropositivity rate between the 2 groups (P = 0.058). In addition, the anti-HBs positivity rate was significantly lower in the group A as compared with the group B during infancy (83.1% vs. 92.1%, P < 0.001). A total of 1,106 anti-HBs-positive subjects underwent serologic tests more than twice. Of these, 217 subjects (19.6%) showed anti-HBs disappearance. After booster vaccinations, 87.4% (83/95) achieved seroconversion from seronegative to seropositive. Our results highlight the importance of lifelong protection against HBV and the possible necessity of booster vaccination after adolescent period.