Publications by authors named "Hyun-Mi Kim"

97 Publications

Oscillatory shear stress promotes angiogenic effects in arteriovenous malformations endothelial cells.

Mol Med 2021 03 31;27(1):31. Epub 2021 Mar 31.

Department of Plastic and Reconstructive Surgery, School of Medicine, Kyungpook National University, 130 Dongdeok-ro, Jung-gu, Daegu, 41944, Korea.

Background: Vascular endothelial cells (ECs) are subject to continuous shear stress due to blood circulation. Mechanical stress due to high shear flow can also cause arteriovenous malformation (AVM) when ECs respond hyper-sensitively to shear flow. This study was conducted to test the hypothesis that angiogenesis could be promoted in response to mechanical stress via regulation of pro-angiogenic factors in AVM cells.

Methods: ECs were extracted from the tissue samples from six AVM patients and six normal patients. Shear stress at 7 dynes/cm2 were applied for 24 h. Before and after application of shear stress to each group, RT-PCR was performed to access the expression levels of angiopoietin2(AGP2), aquaporin1(AQP1) and TGFβR1. Immunofluorescences was also performed to evaluate the level of protein expressions.

Results: In both normal and AVM tissues, AGP2 and TGFβR1 under the shear stress showed increased expression in the ECs compared to the non-sheared samples. When AVMs and normal arterial vasculature were compared, the expression levels of both AGP2 and TGFβR1 in AVMs were higher when compared to normal arterial vasculature with or without shear stress. Immunofluorescence-based protein analysis also confirmed shear-induced AGP2 and TGFβR1 in both samples of normal and AVM patients.

Conclusions: AVMs exhibited higher sensitivity to shear stress by producing higher expressions of some marked genes and proteins that regulate the endothelial functions upon exposure to shear stress. While the physiological mechanism for AVMs remain elusive, our study shows the plausibility of physical stress imposed by the shearing flow can cause the occurrence of AVMs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s10020-021-00291-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8011119PMC
March 2021

The HSP70-fused foot-and-mouth disease epitope elicits cellular and humoral immunity and drives broad-spectrum protective efficacy.

NPJ Vaccines 2021 Mar 26;6(1):42. Epub 2021 Mar 26.

Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gimcheon City, 39660, Gyeongsangbuk-do, Republic of Korea.

Current foot-and-mouth disease (FMD) vaccines have significant limitations, including side effects due to oil emulsions at the vaccination site, a narrow spectrum of protective efficacy, and incomplete host defenses mediated by humoral immunity alone. To overcome these limitations, new FMD vaccines must ensure improved safety with non-oil-based adjuvants, a broad spectrum of host defenses within/between serotypes, and the simultaneous induction of cellular and humoral immunity. We designed a novel, immune-potent, recombinant protein rpHSP70-AD that induces robust cellular immunity and elicits a broad spectrum of host defenses against FMD virus (FMDV) infections. We demonstrated that an oil emulsion-free vaccine containing rpHSP70-AD mediates early, mid-term, and long-term immunity and drives potent host protection against FMDV type O and A, suggesting its potential as an FMD vaccine adjuvant in mice and pigs. These results suggest a key strategy for establishing next-generation FMD vaccines, including novel adjuvants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41541-021-00304-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998017PMC
March 2021

The Feasibility of Cervical Elastography in Predicting Preterm Delivery in Singleton Pregnancy with Short Cervix Following Progesterone Treatment.

Int J Environ Res Public Health 2021 02 19;18(4). Epub 2021 Feb 19.

Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Institute of Women's Medical Life Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul 03722, Korea.

Previous studies demonstrated an association between cervical strain and risk of spontaneous preterm delivery (sPTD). The present study aimed to assess the efficacy of elastography in predicting sPTD at <32 weeks of gestation in women with singleton pregnancies receiving progesterone for short cervix (≤2.5 cm) diagnosed between 16 and 28 weeks of gestation Among 115 participants eligible for analysis, nine had sPTD at <32 weeks. Preprogesterone (PP0) mean internal os strain (IOS), elasticity contrast index (ECI), hardness ratio (HR), one-week postprogesterone (PP1) IOS, mean external os strain (EOS), ECI, and HR were significantly different between groups. Higher PP0 IOS, PP1 IOS, and PP1 EOS were associated with a 2.92, 4.39 and 3.65-fold increase in the risk of sPTD at <32 weeks, respectively (adjusted for cervical length (CL) at diagnosis; = 0.04, 0.012 and 0.026, respectively). A combination of CL at diagnosis, PP0 IOS and PP1 EOS showed a significantly higher area under the receiver operating characteristic curve (0.858) than that of CL alone ( = 0.041). In women with singleton pregnancies receiving progesterone for short cervix, cervical elastography performed before and one week after progesterone treatment may be useful in predicting sPTD at <32 weeks of gestation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18042026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922916PMC
February 2021

Efficient protection against Asia1 type foot-and-mouth disease using a chimeric vaccine strain suitable for East Asia.

Vet Microbiol 2021 Feb 29;253:108975. Epub 2020 Dec 29.

Center for Foot-and-Mouth Disease Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon City, Gyeongsangbuk-do, 39660, Republic of Korea. Electronic address:

The type Asia1 genetic group(G)-V lineage foot-and-mouth disease (FMD) virus was identified in the East-Asian region in 2009. To date, only Shamir has been used as a standard vaccine strain worldwide for type Asia1. To prevent type Asia1 FMD in eastern Asia, two vaccine strains (ASM-R: G-V and ASM-SM: G-V/Shamir fusion) were developed and tested against type Asia1 virus strains. After immunization with the two experimental vaccines, the ASM-SM strain showed a higher level of protection against Shamir virus in mice. Additional immunogenicity tests were carried out in cattle and pigs, revealing sufficient antibody production capable of protecting the animals against the viral challenge. In cattle, the immune response started just 2 weeks after vaccination. Immunogenicity was lower in pigs, but antibody production was greatly increased to a high level after a second vaccination round. In particular, herein, 60 % and 100 % of the vaccinated pigs challenged with the Asia1 Shamir virus were determined to be clinically protected after one and two vaccination rounds with ASM-R, respectively. Pigs vaccinated twice produced sufficient antibody titers with low virus shedding for short time. Moreover, ASM-SM single-vaccinated pigs showed 100 % protection when challenged with the Asia1 Shamir virus. In summary, the vaccine strain ASM-SM designed for the defense of the Asian region efficiently granted protection to pigs against the typical Asia1 virus, Shamir.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2020.108975DOI Listing
February 2021

9‑Hydroxy‑isoegomaketone inhibits LPS‑induced NO and inflammatory cytokine production in RAW264.7 cells.

Mol Med Rep 2021 03 5;23(3). Epub 2021 Jan 5.

Radiation Breeding Research Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup‑si, Jeollabuk‑do 56212, Republic of Korea.

Isoegomaketone (IK) is a known component of that reportedly exhibits anti‑inflammatory, anti‑cancer and anti‑allergic properties. A novel compound known as 9‑HIK has been isolated from the extract of a radiation mutant var. using supercritical carbon dioxide. In the present study, 9‑HIK induced heme oxygenase‑1 (HO‑1) mRNA expression in RAW264.7 cells, with maximal levels observed 4 h after 9‑HIK treatment. In addition, 9‑HIK inhibited the mRNA and protein expression of pro‑inflammatory mediators, such as IL‑6 and interferon‑β, as well as the production of nitric oxide (NO) in lipopolysaccharide‑stimulated RAW264.7 cells. Furthermore, N‑acetyl‑L‑cysteine, a reactive oxygen species scavenger, inhibited NO production and HO‑1 mRNA expression levels through the nuclear factor erythroid 2‑related factor 2 pathway. Overall, 9‑HIK displayed anti‑inflammatory properties in LPS‑induced RAW264.7 cells via direct suppression of inflammatory mediators and HO‑1 induction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2020.11820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809899PMC
March 2021

Uterine Cervical Change at Term Examined Using Ultrasound Elastography: A Longitudinal Study.

J Clin Med 2020 Dec 28;10(1). Epub 2020 Dec 28.

Samsung Medical Center, Department of Obstetrics and Gynecology, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.

The aim of the study was to investigate if there are changes in elastographic parameters in the cervix at term around the time of delivery and if there are differences in the parameters between women with spontaneous labor and those without labor (labor induction). Nulliparous women at 36 weeks of gestation eligible for vaginal delivery were enrolled. Cervical elastography was performed and cervical length were measured using the E-Cervix system (WS80A Ultrasound System, Samsung Medison, Seoul, Korea) at each weekly antenatal visit until admission for spontaneous labor or labor induction. E-Cervix parameters of interest included elasticity contrast index (ECI), internal os strain mean level (IOS), external os strain mean level (EOS), IOS/EOS strain mean ratio, strain mean level, and hardness ratio. Regression analysis was performed using days from elastographic measurement at each visit to admission for delivery and the presence or absence of labor against cervical length, and each E-Cervix parameter fitted to a linear model for longitudinal data measured repeatedly. A total of 96 women were included in the analysis, (spontaneous labor, = 39; labor induction, = 57). Baseline characteristics were not different between the two groups except for cesarean delivery rate. Cervical length decreased with advancing gestation and was different between the two groups. Most elastographic parameters including ECI, IOS, EOS, strain mean, and hardness ratio were significantly different between the two groups. In addition, ECI, IOS, and strain mean values significantly increased with advancing gestation. Our longitudinal study using ultrasound elastography indicated that E-cervix parameters tended to change linearly at term near the time of admission for delivery and that there were differences in E-Cervix parameters according to the presence or absence of labor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm10010075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795469PMC
December 2020

Extracellular vesicles derived from fibroblasts promote wound healing by optimizing fibroblast and endothelial cellular functions.

Stem Cells 2021 Mar 31;39(3):266-279. Epub 2020 Dec 31.

Department of Nuclear Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.

Extracellular vesicles (EVs) have been exhibited as promising candidates for delivering endogenous therapeutic cargos for regenerative therapies. Fibroblasts could be candidate source cells for EVs, to investigate their therapeutic effects in wound healing. Here we demonstrated the isolation and characterization of fibroblast-derived (L929 cell line) EVs (L929-EVs). Furthermore, L929-EVs treatment showed pro-wound healing effects in vitro by enhancing proliferation, migration, and scarless wound healing related genes in fibroblast cells. L929-EVs treatment also enhanced the migration and tube formation of endothelial cells. The combination of L929-EVs with fibrin glue accelerated wound healing in the mouse skin wound model by enhancing collagen formation, collagen maturation, and blood vessels in the wounded skin. The role of fibroblast-derived EVs in wound healing could be an important phenomenon, and fibroblast-derived EVs could be harnessed for wound healing therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/stem.3310DOI Listing
March 2021

The diagnosis of an imperforate anus in female fetuses.

Yeungnam Univ J Med 2020 Oct 7. Epub 2020 Oct 7.

Department of Obstetrics and Gynecology, Kyungpook National University Hospital, Daegu, Korea.

Imperforate anus is an anomaly caused by a defect in the development of the hindgut during early pregnancy. It is a relatively common congenital malformation and is more common in males. Although there are cases of a solitary imperforate anus, the condition is more commonly found as a part of a wider spectrum of other congenital anomalies. Although urgent reconstructive anorectal surgery is not necessary, immediate evaluation is important and urgent decompressive surgery may be required. Moreover, as there are often other anomalies that can affect management, prenatal diagnosis can help in optimizing perinatal care and prepare parents through prenatal counseling. In the past, imperforate anus was diagnosed by prenatal ultrasonography based on indirect signs such as bowel dilatation or intraluminal calcified meconium. Currently, it is diagnosed by directly checking the perineum with prenatal ultrasonography. Despite advances in ultrasound technology, accurate prenatal diagnosis is impossible in most cases and imperforate anus is detected after birth. Here, we present two cases of imperforate anus in female fetuses that were not diagnosed prenatally.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12701/yujm.2020.00507DOI Listing
October 2020

Effect of the Bilayer Period of Atomic Layer Deposition on the Growth Behavior and Electrical Properties of the Amorphous In-Zn-O Film.

ACS Appl Mater Interfaces 2020 Sep 20;12(35):39372-39380. Epub 2020 Aug 20.

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

This study reports on the effect of a bilayer period on the growth behavior, microstructure evolution, and electrical properties of atomic layer deposition (ALD) deposited In-Zn-O (IZO) films, fixing the ALD cycle ratio of In-O/Zn-O as 9:1. Here, the bilayer period is defined as the total number of ALD cycles in one supercycle of In-O and Zn-O by alternately stacking Zn-O and In-O layers at a temperature of 220 °C. IZO films with a bilayer period from 10 to 40 cycles, namely, IZO[In-O/Zn-O = 9:1] to IZO[36:4], result to form an amorphous phase with a resistivity of 4.94 × 10 Ω·cm. However, by increasing the bilayer period above 100 cycles, the IZO films begin to form a mixed amorphous-nanocrystalline microstructure, resulting from the limited intermixing at the interfaces. Concomitantly, the overall film resistivity is considerably increased with a simultaneous decrease in both the carrier mobility and the concentration. These results not only reveal the importance of the bilayer period in designing the ALD stacking sequence in the ALD-IZO, but also provide the possibility of forming various multilayered materials with different electrical properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.0c07540DOI Listing
September 2020

Immunogenicity and protective efficacy of clade 2.3.2.1c and clade 2.3.4.4c H5Nx avian influenza antigen bank vaccines in mice, Korea.

Vaccine 2020 09 27;38(39):6080-6087. Epub 2020 Jul 27.

Avian Influenza Vaccine Research Laboratory, Avian Influenza Research and Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2020.07.033DOI Listing
September 2020

Postnatally diagnosed coexisting congenital diaphragmatic hernia with pulmonary sequestration: a report of two cases.

Obstet Gynecol Sci 2020 Jul 8;63(4):529-533. Epub 2020 Jul 8.

Department of Obstetrics and Gynecology, School of Medicine, Kyungpook National University, Daegu, Korea.

While the associations between pulmonary sequestration (PS) and congenital diaphragmatic hernia (CDH) are known, CDH may be obscured by PS and thus, overlooked on prenatal ultrasonography when coexisting with PS. We present 2 cases of postnatally diagnosed CDH combined with PS. In both cases, PS was prenatally diagnosed as an isolated lung mass, while CDH was confirmed only after birth. Both newborns were sufficiently stable that management was not required immediately after birth. PS may function as an "anatomical barrier" to prevent herniation of the abdominal contents into the chest, thus acting as a "protector" providing normal lung maturation throughout pregnancy. If PS is suspected prenatally, coexisting CDH may be obscured; thus, close prenatal care and counseling of the parents regarding the possibility of CDH are essential. These infants should be delivered at a tertiary center, and imaging should be performed to exclude coexisting CDH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5468/ogs.20052DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7393745PMC
July 2020

Association between gestational age at delivery and lymphocyte-monocyte ratio in the routine second trimester complete blood cell count.

Yeungnam Univ J Med 2021 Jan 18;38(1):34-38. Epub 2020 Jun 18.

Department of Obstetrics and Gynecology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea.

Background: We aimed to determine whether routine second trimester complete blood cell (CBC) count parameters, including neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), and platelet-lymphocyte ratio (PLR), could predict obstetric outcomes.

Methods: We included singleton pregnancies for which the 50-g oral glucose tolerance test and CBC were routinely performed between 24 and 28 weeks of gestation in our outpatient clinic from January 2015 to December 2017. The subjects were divided into three groups according to their pregnancy outcomes as follows: group 1, spontaneous preterm births, including preterm labor and preterm premature rupture of membranes; group 2, indicated preterm birth due to maternal, fetal, or placental causes (hypertensive disorder, fetal growth restriction, or placental abruption); and group 3, term deliveries, regardless of the indication of delivery. We compared the CBC parameters using a bivariate correlation test.

Results: The study included 356 pregnancies. Twenty-eight subjects were in group 1, 20 in group 2, and 308 in group 3. There were no significant differences between the three groups in neutrophil, monocyte, lymphocyte, and platelet counts. Although there was no significant difference in NLR, LMR, and PLR between the three groups, LMR showed a negative correlation with gestational age at delivery (r=-0.126, p=0.016).

Conclusion: We found that a higher LMR in the second trimester was associated with decreased gestational age at delivery. CBC parameters in the second trimester of pregnancy could be used to predict adverse obstetric outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12701/yujm.2020.00234DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787901PMC
January 2021

Protection of layers and breeders against homologous or heterologous HPAIv by vaccines from Korean national antigen bank.

Sci Rep 2020 06 10;10(1):9436. Epub 2020 Jun 10.

Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea.

Korean government has selected and stocked five type antigens of two clades as Korean national antigen bank having high possibility of introduction to Korea. We aimed to evaluate the efficacy of the clade 2.3.2.1c and 2.3.4.4c H5Nx vaccines from the Korean avian influenza (AI) national antigen bank for emergency preparedness for their potency and protective efficacy against lethal homologous and heterologous viruses in layer and breeder chickens practically. The PD (dose of vaccine that protects 50% of chickens from viral challenge) of all vaccinated groups was >50, which was satisfied with minimum antigen requirement of OIE, and the PD levels of the two vaccines differed depending on strain and chicken breed. In homologous challenge, all vaccinated groups exhibited 100% survival with no clinical symptoms and high levels of pre-challenge protective immunity (7.2-8.5 log), although they did not completely prevent virus shedding. On the other hand, against heterologous virus challenge, vaccinated animals exhibited 62.5-80% survival with lower antibody titers (2.3-3.4 log) and a longer period of virus shedding (14 days post infection [dpi]). Our results suggest that the clade 2.3.2.1c and 2.3.4.4c H5Nx vaccines are good candidates for emergency vaccination of commercial chickens and support the idea that close genetic matching between vaccine and challenge virus provides the best protection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-66343-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287076PMC
June 2020

Composition and Antioxidant Activities of Volatile Organic Compounds in Radiation-Bred Cultivars.

Plants (Basel) 2020 Jun 4;9(6). Epub 2020 Jun 4.

Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 56212, Korea.

is a flowering plant belonging to the Asteraceae family. It is an ornamental plant native to the Americas, Asia and Oceania and its flower is used as a raw material for tea and food manufacture in China. In this study, new cultivars of ("golden ring") were developed via radiation-induced mutation of the original cultivar, "pumpkin pie". The chemical composition and antioxidant activities of flowers belonging to three different cultivars were evaluated: "golden ring", "pumpkin pie" and "snow chrysanthemum" (coreopsis tea; ). The volatile compounds were characterized via gas chromatography-mass spectrometry (GC-MS) and 50-59 oils representing 95.3-96.8% of the total volatile compounds in these flower materials were identified. "Golden ring" contained a high amount of fatty acids (38.13%), while "pumpkin pie" and "snow chrysanthemum" teas were rich in aliphatic amides (43.01%) and esters (67.22%), respectively. The antioxidant activities of the volatile oils of these cultivars were evaluated using 1,1-diphenyl-2-picrylhydraxyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays. The volatile extract of "golden ring" showed higher antioxidant activities compared with the extracts of the other cultivars. Therefore, "golden ring" can be used for further development as a raw material for tea manufacture or as a dietary supplement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/plants9060717DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7356690PMC
June 2020

Sheet Resistance Analysis of Interface-Engineered Multilayer Graphene: Mobility Versus Sheet Carrier Concentration.

ACS Appl Mater Interfaces 2020 Jul 26;12(27):30932-30940. Epub 2020 May 26.

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

Both interlayer-undoped and interlayer-doped multilayer graphenes were prepared by the multiple transfers of graphene layers with multiple Cu etching (either dopant-free or doped during etching) and transfer, and the effect of interface properties on the electrical properties of multilayer graphene was investigated by varying the number of layers from 1 to 12. In both the cases, the sheet resistance decreased with increasing number of layers from 700 to 104 Ω/sq for the interlayer-undoped graphene and from 280 to 25 Ω/sq for the interlayer-doped graphene. Further, Hall measurements revealed that the origins of the sheet resistance reduction in the two cases are different. In the interlayer-undoped graphene, the sheet resistance decreased because of the increase in mobility with the addition of inner layers, which has a low carrier density and a high carrier mobility. On the other hand, it decreased because of the increase in sheet carrier density in the interlayer-doped multilayer graphene. The mobility and carrier density variations in both the cases were confirmed by fitting with the model of Hall effect in the heterojunction. In addition, we found that surface property modification by the doping of the top layer and the formation of double-layer graphene with different partial coverages allow the separate control of carrier density and mobility. Our study provides an effective approach for controlling the properties of multilayer graphene for electronic applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.0c04542DOI Listing
July 2020

Sales and immunogenicity of commercial vaccines to H9N2 low pathogenic avian influenza virus in Korea from 2007 to 2017.

Vaccine 2020 04 10;38(16):3191-3195. Epub 2020 Mar 10.

Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea. Electronic address:

The present study was conducted to monitor sales activity and immunogenicity of commercial H9N2 vaccines produced in Korea from 2007 to 2017. Recorded sales of H9N2 vaccine were around 671 million doses, with 10 million doses sold in 2007, rising to a peak of 93 million doses in 2016, with a slight fall in 2017. Multivalent combined vaccines made up around 90% of all vaccine sales, and around 30% of all vaccines were distributed by regional governments for free. The regional vaccination rate was the highest in Gyeonggi and Chungnam, respectively with proportional to the population of layer and breeder chickens. There have been no cases of field infection since 2009. The mean antibody titer was 5.82 log across the study period. Our results suggest that continuous genetic monitoring of H9N2 viruses circulating in the field and updating the vaccine seed strain periodically are necessary in order to control H9N2 outbreaks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2020.02.083DOI Listing
April 2020

Purification of Phenylpropanoids from the Scaly Bulbs of by CPC and Determination of Their DPP-IV Inhibitory Potentials.

ACS Omega 2020 Mar 20;5(8):4050-4057. Epub 2020 Feb 20.

College of Pharmacy, Yeungnam University, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.

The scaly bulbs of (Liliaceae) are used as a food ingredient and a traditional medicine in East Asia. A preliminary study revealed that treatment with 100 μg/mL of the ethyl acetate fraction of this plant material inhibited dipeptidyl peptidase IV (DPP-IV) to 58.99%. Phytochemical studies were conducted to identify the active ingredient, and five compounds, namely, (2.9 mg, 75.8% purity at 320 nm), (12.2 mg, 97.9% purity at 320 nm), (3.1 mg, 66.5% purity at 320 nm), (6.8 mg, 96.9% purity at 320 nm), and (6.2 mg, 90.2% purity at 320 nm) were purified from 200 mg of the ethyl acetate fraction of via centrifugal partition chromatography (CPC) with a two-phase solvent system composed of chloroform/methanol/isopropanol/water (5:2:2:4, v/v/v/v) in an ascending mode. Their structures were identified as 1---coumaroyl-2--β-glucopyranosylglycerol (regaloside D, ), 3,6'--diferuloylsucrose (), 1---coumaroyl-2--β-glucopyranosyl-3--acetylglycerol (regaloside B, ), 1---coumaroylglycerol (), and 4--acetyl-3,6'--diferuloylsucrose (), respectively, by H and C NMR and MS analysis. Compounds and exhibited DPP-IV inhibitory activities with IC values of 46.19 and 63.26 μM, respectively. Compounds , , and did not show activities, indicating that biphenylpropanoids linked via the sugar moiety are more effective than phenylpropanoids with glycerol or glyceryl glucoside. This is the first report of simultaneous separation of five phenylpropanoids from by CPC and evaluation of their DPP-IV inhibitory activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.9b03649DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057705PMC
March 2020

An electrophoretic DNA extraction device using a nanofilter for molecular diagnosis of pathogens.

Nanoscale 2020 Feb;12(8):5048-5054

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

Rapid and efficient nucleic acid (NA) extraction and concentration are required for point-of-care analysis in order to prevent an epidemic/pandemic disease outbreak. Typical silica-based NA extraction methods have limitations such as being time-consuming, requiring human intervention, and resulting in a low recovery yield. In this study, we have developed a pathogenic DNA extraction device based on electrokinetic separation incorporated with a silicon nitride (SiNx) nanofilter, which expedites the DNA extraction procedure with advantages of being convenient, efficient, and inexpensive. This DNA extraction device consists of a computer numerical control (CNC) milled-Teflon gadget with a cis-chamber as a cell lysate reservoir and a trans-chamber as a elution solution reservoir, with the SiNx nanofilter being inserted between the two chambers. The SiNx nanofilter was fabricated using a photolithographic method in conjunction with nanoimprinting. Approximately 7.2 million nanopores of 220 nm diameter were located at the center of the nanofilter. When a DC electric field is applied through the nanopores, DNA is transferred from the cis-chamber to the trans-chamber to isolate the DNA from the cell debris. To demonstrate the DNA extraction performance, we measured the absorbances at 260 and 280 nm and performed a real-time polymerase chain reaction (real-time PCR) using the recovered DNA to verify its feasibility for downstream genetic analysis. Moreover, the DNA extraction device was successfully operated using a 1.5 V alkaline battery, which verifies the portability of the device for point-of-care testing. Such an advanced DNA extraction system can be utilized in various fields including clinical analysis, pathogen detection, forensic analysis, and on-site detection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9nr10675hDOI Listing
February 2020

Selective Atomic Layer Deposition of Metals on Graphene for Transparent Conducting Electrode Application.

ACS Appl Mater Interfaces 2020 Mar 15;12(12):14331-14340. Epub 2020 Mar 15.

School of Materials Science and Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea.

Although graphene has considerable potential as a next-generation transparent conducting electrode (TCE) material owing to its excellent optical transparency and flexibility, its electrical properties require further improvement for industrial application. This study reports a pathway of doping graphene by selective atomic layer deposition (ALD) of metals to elevate the electrical conductivity of graphene. Introduction of a novel Pt precursor [dimethyl(,-dimethyl-3-butene-1-amine-)platinum(II); CHNPt; DDAP] facilitates a low-temperature (165 °C) process. The sheet resistance () of graphene is reduced significantly from 471 to 86.8 Ω sq after 200 cycles of Pt ALD, while the optical transmittance at 550 nm () is maintained above 90% up to 200 cycles due to the selective growth of Pt on the defects of graphene. Furthermore, comprehensive analysis, including metal (Ru, Pt, and Ni) ALD on graphene, metal (Ru, Pt, Ni, Au, and Co) evaporation on graphene, and change in the ALD chemicals, demonstrates that ALD allows efficient graphene doping and the oxygen affinity of the metal is one of the key properties for efficient graphene doping. Finally, Pt ALD is applied to a multilayer graphene to further reduce down to 75.8 Ω sq yet to be highly transparent ( 87.3%) after 200 cycles. In summary, the selective ALD of metals opens a way of improving the electrical properties of graphene to a level required for the industrial TCE application and has the potential to promote development of other types of functional metal-graphene composites.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.9b23261DOI Listing
March 2020

Validation of mouse phosphoprotein enriched in astrocyte 15 (mPEA15) expressing transgenic pig as a potential model in diabetes translational research.

3 Biotech 2020 Feb 7;10(2):34. Epub 2020 Jan 7.

Animal Biotechnology Division, National Institute of Animal Science, RDA, Jeonju, Republic of Korea.

The present study aimed to investigate the characteristics of mPEA15 expressing transgenic pig (TG pig) as a potential model for diabetes. Expression analysis confirmed the ubiquitous expression of mPEA15 in TG pigs at F4. Oral glucose tolerance test results showed that restoration of normal glucose levels was significantly delayed in the TG pigs when compared with that in the wild-type pigs (WT pigs). Primary skeletal muscle cells isolated from TG pigs demonstrated reduced glucose uptake and reduced GLUT4 translocation to the plasma membrane in response to insulin treatment. Combined, these results suggest that mPEA15 expressing pigs has a glucose intolerance and insulin resistance which are known to mediate the pathophysiology of type 2 diabetes mellitus. Thus, mPEA15 transgenic pigs would serve as a promising model for diabetes translational research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13205-019-2021-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946770PMC
February 2020

Standardization of measurement of cervical elastography, its reproducibility, and analysis of baseline clinical factors affecting elastographic parameters.

Obstet Gynecol Sci 2020 Jan 27;63(1):42-54. Epub 2019 Dec 27.

Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Objective: To provide a standardized protocol for the measurement of cervical strain elastography, present its reproducibility, and analyze baseline clinical factors affecting the measurement of elastographic parameters.

Methods: This study was performed by the Korean Research Group of Cervical Elastography. We enrolled pregnant women according to our study protocol. After measuring the cervical length, elastography was performed using the E-Cervix quantification tool to measure the strain of the cervix using intrinsic compression. We evaluated 5 elastographic parameters, namely, the strain of the internal os of the cervix (IOS), strain of the external os of the cervix (EOS), ratio of the strain of IOS and EOS, elasticity contrast index, and hardness ratio. For baseline clinical factors, we examined the maternal body mass index, blood pressure, heart rate, uterine artery Doppler indices, and fetal presentation.

Results: We established a specific protocol for the measurement of cervical elastography using the E cervix program. For all elastographic parameters, the intra-observer intraclass correlation coefficient (ICC) ranged from 0.633 to 0.723 for single measures and from 0.838 to 0.887 for average measures, and the inter-observer ICC ranged from 0.814 to 0.977 for single measures and from 0.901 to 0.988 for average measures. Regression analysis showed that the measurement of the elastographic parameter was not affected by baseline clinical factors.

Conclusion: We present a standardized protocol for the measurement of cervical elastography using intrinsic compression. According to this protocol, reproducibility was acceptable and the measurement of elastographic parameters was not affected by the baseline clinical factors studied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5468/ogs.2020.63.1.42DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6962587PMC
January 2020

Surface modification of solid-state nanopore by plasma-polymerized chemical vapor deposition of poly(ethylene glycol) for stable device operation.

Nanotechnology 2020 May 16;31(18):185503. Epub 2020 Jan 16.

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

Biopolymer adsorption onto a membrane is a significant issue in the reliability of solid-state nanopore devices, since it degrades the device performance or promotes device failure. In this work, a poly(ethylene glycol) (PEG) layer was coated on a silicon nitride (SiN) membrane by plasma-polymerized vapor deposition to inhibit biopolymer adsorption. From optical observations, the deposited PEG layer demonstrated increased hydrophilicity and anti-adsorption property compared to the SiN surface. Electrical properties of the PEG/SiN nanopore were characterized, showing Ohmic behavior and a 6.3 times higher flicker noise power due to the flexible conformation of PEG in water. Antifouling performance of each surface was analyzed by measuring the average time from voltage bias to the first adsorption during DNA translocation experiments, where the modified surface enabled two times prolonged device operation. The time to adsorption was dependent on the applied voltage, implying adsorption probability was dominated by the electrophoretic DNA approach to the nanopore. DNA translocation behaviors on each surface were identified from translocation signals, as the PEG layer promoted unfolded and fast movement of DNA through the nanopore. This work successfully analyzed the effect of the PEG layer on DNA adsorption and translocation in solid-state nanopore experiments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-6528/ab6cdbDOI Listing
May 2020

The Effect of a Transdermal Scopolamine Patch on Postoperative Nausea and Vomiting after Retromastoid Craniectomy with Microvascular Decompression: A Preliminary Single Center, Double-Blind, Randomized Controlled Trial.

J Clin Med 2020 Jan 7;9(1). Epub 2020 Jan 7.

Department of Neurosurgery, Seoul National University Bundang Hospital, Gyeonggi-do 13620, Korea.

We performed this prospective double-blind randomized controlled trial to identify the effect of a preoperative prophylactic transdermal scopolamine (TDS) patch on postoperative nausea and vomiting (PONV) after retromastoid craniectomy with microvascular decompression (RMC-MVD). We recruited 38 patients undergoing RMC-MVD and randomized them into two groups: the TDS group ( = 19, application of the TDS patch) and placebo group ( = 19, application of a sham patch). Nausea (as a self-reported 100-mm visual analog scale (VAS) score; range, 0 (no nausea) to 10 (worst nausea)), vomiting, and the use of antiemetics were the primary endpoints. There was no significant difference in terms of the incidence of PONV (73.7% in the TDS group and 78.9% in the placebo group; = 1.00) between the groups. However, the mean nausea VAS score was significantly different at arrival to the general ward (0.93 ± 1.71 in the TDS group vs. 2.52 ± 2.85 in the placebo group; p = 0.046), and throughout the study period (0.03 ± 0.07 in the TDS group vs. 0.44 ± 0.71 in the placebo group; p = 0.029). Rescue antiemetics were more frequently used in the placebo group than in the TDS group (9 (47.4%) vs. 2 (10.5%), respectively; = 0.029). The mean number of antiemetics used throughout the study period was significantly higher in the placebo group than in the TDS group (1.37 ± 2.19 vs. 0.16 ± 0.50, respectively; p = 0.029). The preoperative prophylactic use of a TDS patch was safe and effective in the management of PONV after RMC-MVD in terms of the severity of PONV and the use of rescue antiemetics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm9010156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019292PMC
January 2020

Direct electrophoretic microRNA preparation from clinical samples using nanofilter membrane.

Nano Converg 2020 Jan 13;7(1). Epub 2020 Jan 13.

Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea.

A method to directly collect negatively charged nucleic acids, such as DNA and RNA, in the biosamples simply by applying an electric field in between the sample and collection buffer separated by the nanofilter membrane is proposed. The nanofilter membrane was made of low-stress silicon nitride with a thickness of 100 nm, and multiple pores were perforated in a highly arranged pattern using nanoimprint technology with a pore size of 200 nm and a pore density of 7.22 × 10/cm. The electrophoretic transport of hsa-mir-93-5p across the membrane was confirmed in pure microRNA (miRNA) mimic solution using quantitative reverse transcription-polymerase chain reactions (qRT-PCR). Consistency of the collected miRNA quantity, stability of the system during the experiment, and yield and purity of the prepared sample were discussed in detail to validate the effectiveness of the electrical protocol. Finally, in order to check the applicability of this method to clinical samples, liquid biopsy process was demonstrated by evaluating the miRNA levels in sera of hepatocellular carcinoma patients and healthy controls. This efficient system proposed a simple, physical idea in preparation of nucleic acid from biosamples, and demonstrated its compatibility to biological downstream applications such as qRT-PCR as the conventional nucleic acid extraction protocols.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40580-019-0212-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6955385PMC
January 2020

Exposure to cold airflow alters skin pH and epidermal filaggrin degradation products in children with atopic dermatitis.

Allergol Int 2020 Jul 26;69(3):429-436. Epub 2019 Dec 26.

Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, South Korea. Electronic address:

Background: We aimed to evaluate the influence of cold airflow from the air conditioner on skin barrier function and filaggrin degradation products (FDPs) in children with atopic deramtitis (AD).

Methods: In a case-control study, 28 children with AD and 12 normal children without AD were exposed to one of two air conditioner modes (conventional or wind-free) for 2 h. Skin temperature, transepidermal water loss (TEWL), and skin pH were measured on right cheek and forearm at pre- and post-exposure time points. We also measured filaggrin and FDPs from the volar surface of the forearm.

Results: In AD patients, skin temperature on the forearm decreased after exposure to the conventional and wind-free modes (P < 0.001 and P = 0.026), and TEWL on the cheek and the forearm decreased in the wind-free mode (P = 0.037 and 0.002). Skin pH on the cheek increased only after exposure to the conventional mode in AD group (P = 0.002). However, no changes in TEWL and skin pH were found after exposure to either the conventional or the wind-free mode in the control group. In AD children, the levels of pyrrolidone carboxylic acid (PCA) and cis-urocanic acid (UCA) were reduced only after exposure to the conventional mode (all P = 0.033). The percent changes of PCA and cis-UCA were higher in the AD group than those in the control group after exposure to conventional mode (P = 0.029 and 0.046).

Conclusions: Skin barrier function in children with AD may be altered by the exposure to cold airflow from a conventional air conditioner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.alit.2019.11.004DOI Listing
July 2020

Electrical properties of graphene/InO bilayer with remarkable uniformity as transparent conducting electrode.

Nanotechnology 2020 Feb 20;31(9):095708. Epub 2019 Nov 20.

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

A graphene/InO bilayer (termed as GI-bilayer) is proposed as a transparent conducting electrode with remarkably improved areal-uniformity. To fabricate this new structure, an InO layer with a thickness of less than 50 nm was grown by atomic layer deposition and then a graphene layer was grown by chemical vapor deposition and subsequently transferred onto the as-grown InO layer. Electrical and optical properties of the GI-bilayer were systematically studied to verify effects of the underlying InO layer. Hall measurements and following analysis showed a conductance enhancement of the GI-bilayer owing to p-type doping of graphene. Specifically, Raman analysis and ultraviolet photoelectron spectroscopy were performed to prove p-type doping of the graphene in the GI-bilayer. In addition, the GI-bilayer exhibited the significantly improved uniformity of the sheet resistance compared to that of a conventional monolayer of graphene. There was a duality on the role of the InO underlayer in the GI-bilayer. It acted as a dopant layer to the graphene and lowered the sheet resistance from 863 to 510 Ω/sq as well as compensated microscale defects on graphene. More importantly, the InO underlayer resulted in the extremely reduced standard deviation of sheet resistance from 150 to 7.5 Ω/sq over the area of 49 cm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-6528/ab599cDOI Listing
February 2020

Protective efficacy of vaccines of the Korea national antigen bank against the homologous H5Nx clade 2.3.2.1 and clade 2.3.4.4 highly pathogenic avian influenza viruses.

Vaccine 2020 01 25;38(3):663-672. Epub 2019 Oct 25.

Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea. Electronic address:

The occurrence of severe outbreaks of highly pathogenic avian influenza in Korea led to establishment of a national antigen bank for emergency preparedness. Here, we developed five vaccines for this bank (clade 2.3.2.1C, clade 2.3.4.4A, B, C, and D) by reverse genetics, inactivated them with formalin, and evaluated the protective efficacy and potency of serial dilutions against lethal homologous challenge in specific-pathogen-free chickens. After vaccination with one dose, each vaccine resulted in 100% survival, with no clinical symptoms, or lack of detectable virus shedding, and high levels of pre-challenge protective immunity (8.4-10.2 log). After vaccination with one-tenth of the full dose, protection was similar to that with the full dose. After vaccination with one-hundredth of the initial dose, survival was 20-80%, and all vaccines showed virus shedding. Four vaccines (excluding clade 2.3.2.1C) had satisfactory potency. In antibody-persistence tests, all vaccines maintained long-lasting protective immunity. Our results suggest that inactivated reverse-genetics vaccines genetically matched to outbreak viruses provide adequate protection after a single vaccination.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2019.10.044DOI Listing
January 2020

Prediction of the skin sensitization potential of didecyldimethylammonium chloride and 3,7-dimethyl-2,6-octadienal and mixtures of these compounds with the excipient ethylene glycol through the human Cell Line Activation Test and the Direct Peptide Reactivity Assay.

Toxicol Ind Health 2019 Aug;35(8):507-519

1 Department of Occupational Health, College of Bio-Medical Sciences, Daegu Catholic University, Gyeongbuk, Republic of Korea.

In commercial products such as household deodorants or biocides, didecyldimethylammonium chloride (DDAC) often serves as an antimicrobial agent, citral serves as a fragrance agent, and the excipient ethylene glycol (EG) is used to dissolve the active ingredients. The skin sensitization (SS) potentials of each of these substances are still being debated. Moreover, mixtures of DDAC or citral with EG have not been evaluated for SS potency. The alternative assay called human Cell Line Activation Test (h-CLAT) and Direct Peptide Reactivity Assay (DPRA) served to address these issues. On three independent runs of h-CLAT, DDAC and citral were predicted to be sensitizers while EG was predicted to be a non-sensitizer and also by the DPRA. Mixtures of DDAC or citral with EG at ratios of 7:3 and 1:4 w/v were all positive by the h-CLAT in terms of SS potential but SS potency was mitigated as the proportion of EG increased. Citral and its EG mixtures were all positive but DDAC and its EG mixtures were all negative by the DPRA, indicating that the DPRA method is not suitable for chemicals with pro-hapten characteristics. Since humans can be occupationally or environmentally exposed to mixtures of excipients with active ingredients, the present study may give insights into further investigations of the SS potentials of various chemical mixtures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0748233719869514DOI Listing
August 2019

Atomic Layer Deposition of Nickel Using a Heteroleptic Ni Precursor with NH and Selective Deposition on Defects of Graphene.

ACS Omega 2019 Jun 25;4(6):11126-11134. Epub 2019 Jun 25.

School of Materials Science and Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea.

Atomic layer deposition (ALD) of Ni was demonstrated by introducing a novel oxygen-free heteroleptic Ni precursor, (η-cyclohexenyl)(η-cyclopentadienyl)nickel(II) [Ni(Chex)(Cp)]. For this process, non-oxygen-containing reactants (NH and H molecules) were used within a deposition temperature range of 320-340 °C. Typical ALD growth behavior was confirmed at 340 °C with a self-limiting growth rate of 1.1 Å/cycle. Furthermore, a postannealing process was carried out in a H ambient environment to improve the quality of the as-deposited Ni film. As a result, a high-quality Ni film with a substantially low resistivity (44.9 μΩcm) was obtained, owing to the high purity and excellent crystallinity. Finally, this Ni ALD process was also performed on a graphene surface. Selective deposition of Ni on defects of graphene was confirmed by transmission electron microscopy and atomic force microscopy analyses with a low growth rate (∼0.27 Å/cycle). This unique method can be further used to fabricate two-dimensional functional materials for several potential applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.9b01003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6648170PMC
June 2019

Comparison of Growth Behavior and Electrical Properties of Graphene Grown on Solid and Liquid Copper by Chemical Vapor Deposition.

J Nanosci Nanotechnol 2020 Jan;20(1):316-323

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea.

We study the graphene growth behavior above and below the copper (Cu) melting point (1083 °C) by only changing the growth temperature from 1020 °C to 1100 °C at intervals of 40 °C, to investigate the effect of the Cu phase as a catalyst layer in graphene growth. We investigate the graphene growth behavior by observing the changes in nucleation density and grain size with growth time. As the phase of the Cu catalyst changes from solid to liquid, the grain size of graphene increases by 2 orders of magnitude from 0.4 to 40 m, while the nuclei density decreases by 4 orders of magnitude from 3.02/m₂ to 0.0004/m₂. Additionally, as in previous studies, graphene growth shows a well-aligned hexagonal shape on liquid Cu although graphene on solid Cu shows an irregular shape under the same growth conditions. The effect of the smooth surface of the liquid metal catalyst on graphene growth is remarkable even after considering the temperature difference. The reduction of defect density arising from the increase of the graphene grain size is confirmed by Raman spectroscopy. Additionally, the improvement in electrical properties is also investigated by Hall measurements.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1166/jnn.2020.17279DOI Listing
January 2020