• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 춘계학술대회논문집
• /
• pp.666-669
• /
• 2008

Droplet in miniaturized microfluidic systems have received much focused attention recently. In this work, electrical charging phenomenon of a conducting water droplet on the electrode under the dc electric field is studied and using this phenomenon droplet actuation method for microreactor applications is experimentally demonstrated. To find effects of key factors, the effects of electric field, medium viscosity, and droplet size are investigated. A scaling law of charging for the conducting droplet is derived from the experimental results. Unlike the case of a perfect conductor, the estimated amount of electrical charge ($Q_{est}$) of a water droplet is proportional to the 1.59 power of the droplet radius (R) and the 1.33 power of the electric field strength (E). (For a spherical perfect conductor, Q is proportional to R2 and E.) It is thought that the differences are mainly due to incomplete charging of a water droplet resulted from the combined effect of electrochemical reaction at electrode and the relatively low conductivity of water. Using this phenomenon, we demonstrate the transport of the charged droplet and fusion of two oppositely-charged droplets. When electric field is subjected sequentially on the electrode, the charged droplet is transported on the electrode. For the visualization of fusion of charged droplets, the precipitation reaction is used. When subjected to a DC voltage, two droplets charged are moving and merging toward each other due to the Coulombic force and chemical reaction is simultaneously occurred by coalescence of droplets. It may be due to the interchange effect of charge. It is shown that the droplet can be used for microreactor where transporting, merging etc. of reagents constitute unit operation.

• 부모자녀건강학회지
• /
• 제14권2호
• /
• pp.55-61
• /
• 2011

Purpose: This is a descriptive study to identify the relationships of depression, health status, and parenting stress of caregivers of children in poverty. Methods: The participants were 42 caregivers of preschool or school age children enrolled for the Dream Start Program in a city of Kyeonggi province, which is a program of the Korean Ministry of Health & Welfare offering services for growth and development of low-income children. Data were collected from November, 2009 to February, 2010 by using a questionnaire. Results: The vast majority of the participants were mothers (n=33, 78.6%), and less than a half were married (n=16, 38.1%). Depression of the participants was at the moderate level ($18.60{\pm}10.13$). They perceived their health was fair ($81.10{\pm}18.97$). Their parenting stress was high ($93.45{\pm}20.06$). Their parenting stress was significantly correlated with depression (r=.57, p<.001) and perceived health status (r=.49, p=.001), which indicates their parenting stress was high as their depression was high or they perceived they were not healthy. Conclusion: The study results suggest to provide the caregivers of children in poverty with a well- developed program to manage their depression and parenting stress and ultimately to improve their mental health.

• 한국수산과학회지
• /
• 제47권6호
• /
• pp.927-934
• /
• 2014

Marine algal flora and community structure were seasonally examined at Jungjado, on the southern coast of Korea, from July 2007 to May 2008. A total of 112 seaweeds, including 15 green, 24 brown, and 73 red algae, were identified and 33 species were found throughout the year. The average seaweed biomass was 145.78 g dry weight $m^{-2}$, and the biomass was maximal in winter (184.74 g) and minimal in autumn (106.17 g). The dominant and subdominant species in terms of biomass were Sargassum thunbergii and Grateloupia elliptica in summer, S. thunbergii and Corallina pilulifera in autumn, S. thunbergii and Chondracanthus intermedius in winter, and Sargassum fusiforme and G. elliptica in spring. The vertical distribution patterns of seaweeds from the upper to lower intertidal zones at Jungjado were S. thunbergii - Ulva conglobata - Gelidium elegans in summer; Caulacantus ustulatus - Chondria crassicaulis - C. pilulifera in autumn; Ulva australis - S. thunbergii - G. elliptica in winter; and Gloiopeltis tenax - S. fusiforme - G. elliptica in spring. Seasonally the evenness, richness, and diversity indices tended to have their highest values during the winter and their lowest values in the summer. However, the dominant index was recorded as lowest in winter and highest in the summer. The C/P, R/P, and (R+C)/P values reflecting the flora characteristics were 0.58, 3.04, and 3.62, respectively.

• Clinical and Experimental Reproductive Medicine
• /
• 제30권4호
• /
• pp.269-280
• /
• 2003

Objective: We reported the overcoming effect of $Ni^{2+}$ on the in vitro 2-cell block of mouse embryos. In this study, we aim to investigate whether $Ni^{2+}$ should induce intracellular $Ca^{2+}$ transient in the mouse embryos. Materials and Methods: Embryos were collected at post hCG 32hr from the oviduct of the ICR mouse and cultured in M2 medium omitted phenol red. Intracellular $Ca^{2+}$ was checked by using a confocal laser scanning microscope and fluo-3AM by using various intracellular $Ca^{2+}$ antagonists. Results: In 1mM $Ni^{2+}$ treated medium which contained $Ca^{2+}$(1.71mM), 75.7% of the embryos showed $[Ca^{2+}]i$ transient about 200 sec later. In the $Ca^{2+}$-free medium, 69.8% of the embryos showed $[Ca^{2+}]i$ transient. In U73122, phospholipaseC(PLC) inhibitor (5uM, 10min) pretreated group, 33.3% of the embryos showed $[Ca^{2+}]i$ transient. Heparine, inositol 1, 4, 5-triphosphate receptor(IP3R) antagonist preinjected embryos showed no response with 1mM $Ni^{2+}$. In danthrolene treatment, ryanodine receptor(RyR)-antagonist, 43% embryos showed $[Ca^{2+}]i$ transient but they showed delayed response about 340sec in the presence of $Ca^{2+}$. Conclusions: Summing up the above results, $Ni^{2+}$ seems to induce $Ca^{2+}$-release from the $Ca^{2+}$-store even in the $Ca^{2+}$-free medium. IP3 receptors of the mouse 2-cell embryos might have an essential role for the intracellular $Ca^{2+}$ increase by $Ni^{2+}$.

• Acute and Critical Care
• /
• 제33권4호
• /
• pp.276-279
• /
• 2018

In pediatric patients, a laryngeal mask airway (LMA) is usually used during minor surgeries that require general anesthesia. No esophageal injury has been reported after insertion of an LMA. We report a case of an esophageal injury with intramural dissection after an $i-gel^{(R)}$ (size, 1.5; Intersurgical Ltd.) insertion in a pediatric patient. A 2-month-old male infant was hospitalized for left inguinal herniorrhaphy. After induction of anesthesia, a trained resident tried to insert an $i-gel^{(R)}$. However, it was only successful after three attempts. Dysphagia was sustained until postoperative day 10, and the pediatrician observed duplication of the esophagus on gastroendoscopy. However, a whitish mucosal lesion, which looked like a scar, was observed, and previous lesions suggestive of esophageal duplication were almost healed on postdischarge day 11. His condition was diagnosed as dysphagia and esophagitis due to an esophageal laceration, not esophageal duplication. He was scheduled for symptomatic treatment with a proton pump inhibitor. In conclusion, although an esophageal injury or perforation in pediatric patients is rare, an LMA insertion or a procedure such as aspiration or nasogastric tube insertion should be performed gently to avoid a possible injury to the esophagus in pediatric patients.

• Journal of Microbiology and Biotechnology
• /
• 제33권6호
• /
• pp.753-759
• /
• 2023

The genus Paenibacillus contains a variety of biologically active compounds that have potential applications in a range of fields, including medicine, agriculture, and livestock, playing an important role in the health and economy of society. Our study focused on the bacterium SS4^T (KCTC 43402^T = GDMCC 1.3498^T), which was characterized using a polyphasic taxonomic approach. This strain was analyzed using antiSMASH, BAGEL4, and PRISM to predict the secondary metabolites. Lassopeptide clusters were found using all three analysis methods, with the possibility of secretion. Additionally, PRISM found three biosynthetic gene clusters (BGC) and predicted the structure of the product. Genome analysis indicated that glucoamylase is present in SS4^T. 16S rRNA sequence analysis showed that strain SS4^T most closely resembled Paenibacillus marchantiophytorum DSM 29850^T (98.22%), Paenibacillus nebraskensis JJ-59^T (98.19%), and Paenibacillus aceris KCTC 13870^T (98.08%). Analysis of the 16S rRNA gene sequences and Type Strain Genome Server (TYGS) analysis revealed that SS4^T belongs to the genus Paenibacillus based on the results of the phylogenetic analysis. As a result of the matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) results, SS4^T was determined to belong to the genus Paenibacillus. Comparing P. marchantiophytorum DSM 29850^T with average nucleotide identity (ANI 78.97%) and digital DNA-DNA hybridization (dDDH 23%) revealed values that were all less than the threshold for bacterial species differentiation. The results of this study suggest that strain SS4^T can be classified as a Paenibacillus andongensis species and is a novel member of the genus Paenibacillus.

• Archives of Plastic Surgery
• /
• 제33권1호
• /
• pp.39-45
• /
• 2006

This study is to examine the relationship between TGF-b1 expression and CTGF expression, and to evaluate the effect of Sp1 blockade on the expression of TGF-b1, CTGF and extracellular genes, clones of fibroblasts stably transfected with Sp1 decoy ODN. R-Sp1 decoy ODN was highly resistant to degradation by nucleases or serum, compared to the linear or phosphorothioated-Sp1 decoy ODN. Skin wounds were created on the back of 36 anesthetized rats. They were divided into four groups-the rats with normal skin, with wounded skin without decoy, with wounded skin injected with R-Sp1 decoy, and with wounded skin injected with mismatched R-Sp1 decoy, respectively. Skins were collected at 3rd, 5th, 7th, 14th day after wounding. Cellular RNA was extracted by RT-PCR analysis. TGF-${\beta}1$ and CTGF were deeply related with skin fibrosis during scar formation and it appeared that TGF-${\beta}1$ may cause the induction of CTGF expression. R-Sp1 decoy ODN inhibited TGF-${\beta}1$ and CTGF expression both in cultured fibroblasts and in the skin of rats. These results indicate that targeting Sp1 with R-type decoy efficiently blocks extracellular matrix gene expression, and suggest an important new therapeutic approach to control the scarring in normal wound healing and fibrotic disorders.

• 한국동물위생학회지
• /
• 제26권3호
• /
• pp.203-214
• /
• 2003

Scrub typhus and murine typhus are common endemic febrile illness in the fall in Korea. Scrub typhus is caused by Orientia tsutsugomushi, murine typhus is caused by Rickettsia typhi. Trombiculid mites are known as both the vector and the reservoir host of O tsutsugamushi, the mites which transmit O tsutsugomushi have been reported to be Leptotrombidium pallidum and L scutellare. The author carried out an epidemiological study of scrub typhus and murine typhus in Kyodong-Myeon, Kanghwa-Gun, Incheon in relation to the residents and the host rodents, such as their distribution, seroepidemiology, and population density of chigger mites. 1. Out of 900 residents, 33(3.7%) showed positive reaction to O tsutsugamushi, 24(2.7%) to R typhi. 2. In the seropositives to O tsutsugamushi or R typhi, between the sixties and the seventies of the age were dominant. 3. In the seropositives to O tsutsugamushi serotypically Gilliam was dominant. 4. Among the total 42 field rodents trapped by the sherman traps, 18 rodents were Apodemus agrarius(42.9%), 13 rodents were Crocidura lasiura(31.0%), 5 rodents were Musmusculus(11.9%), 2 rodents(4.8%) were Crocidura suaveolens, Rattus norvegicus, Tscherskia triton, respectively. 5. Out of 42 field rodents, 25 were parasitized by 4,419 chigger mites, showing 59.5% of the infestation rate and 98.8 of the chigger index. L pallidum parasitized in A agrarius, C lasiura, M musculus, R norvegicus and T triton, and L scutellare parasitized only C lasiura. 6. Antibodies in the sera of field rodents against O tsutsugamushi and R typhi were investigated by indirect immunofluorescent antibody technique. Positive rate of antibody against O tsutsugamushi were 11.9(5 of 42) and all of the positive is A agrarius. Antibody against R typhi was not detected. These results might provide the basic information for the management of scrub typhus and murine typhus in Kyodong-myeon, where the epidemiological studies on scrub typhus and murine typhus was not carried out enough.

• 대한수의학회지
• /
• 제46권4호
• /
• pp.347-353
• /
• 2006

Serum samples of 30 chickens per flock from 6 grand parent stock (GPS) farms and 70 parent stock (PS) farms were collected for seroprevalent study of pullorum disease-fowl typhoid (PD-FT) infection by serum plate agglutination test (SPA). The incidence of PD-FT infection in GPS flocks and PS flocks were 0% and 15.7%, respectively. Especially PS flocks infected with PD-FT showed age dependent patterns that 22.2% of flocks between 20 to 30 weeks of age and 38.9% of flocks between 30 to 40 weeks of age were positive. The incidence of GPS flocks and PS flocks using Salmonella (S.) gallinarum 9R (SG9R) live vaccine were 33.3% and 58.6%, respectively. The sero-positive rate of 11 flocks were 6.7-83.3% by SPA and 2.9-55.6% by enzyme linked immunosorbent assay (ELISA), and ELISA showed more lower antibody levels than SPA. Furthermore, specific antibodies produced by SG9R vaccination were detectable by SPA using SG9R antigen without cross-reaction with the PD-FT infection.

• 한국패류학회지
• /
• 제32권3호
• /
• pp.197-202
• /
• 2016

본 연구에서는 한국 연안의 생태학적 건강도를 조사하는 과정에서 이매패류 5종 (굴, 지중해담치, 바지락, 대복, 둥글레조개) 에서 발견된 이성생식세포 발현현상을 보고한다. 암컷에서 이성생식세포 발현 현상은 반대 성의 생식세포들이 난자형성소낭 내부와 소낭 사이에서 단독 또는 무리지어 나타나는 형태였다. 이성생식세포 발현 현상이 관찰된 정소에서 난모세포들은 대부분 난황형성전기 또는 난황형성개시기 단계였다. 이들은 단독으로 산재되어 있거나 또는 정자형성소낭의 내부와 소낭 사이에 무리지어 존재하고 있었다. 굴에서 이성생식세포 발현율은 약 10.4% (n = 19/183) 로 수컷 (9.7%, n = 13/134) 보다 암컷 (12.2%, n = 6/49) 에서 높게 나타났다. 지중해담치에서 이성생식세포 발현율은 약 31.7% (n = 19/60) 였으며, 수컷 (25.9%, n = 7/27) 보다 암컷 (36.4%, n = 12/33)에서 높게 나타났다. 바지락 이성생식세포 발현율은 11.2% (n = 11/98) 였는데, 암컷 (7.1%, n = 4/56) 보다 수컷 (16.7%, n = 7/42) 에서 높았다. 대복의 이성생식세포 발현율은 약 28% (n = 30/107) 로 암컷 (24.5%, n = 13/53) 보다 수컷 (31.5%, n = 17/54) 에서 높았다. 둥글레조개에서 이성생식세포 발현율은 약 18.4% (n = 7/38) 였는데, 수컷 (8.3%, n = 2/24) 에 비해 암컷 (35.7%, n = 5/14) 에서 높았다.