• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.486-493
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• 2010

This article introduces a novel ultra wideband(UWB) bandpass filter(BPF) with sharp roll-off characteristics in stripline structure. The UWB characteristic is basically obtained from capacitive coupled cross resonator. The resonator has ${\lambda}/2$ length. And at the center of the resonator, two stubs are loaded, one is a ${\lambda}/8$ short-circuited stub and the other is a ${\lambda}/8$ open-circuited stub. The two stubs provide two attenuation poles at lower and upper cutoff frequencies. For input and output lines, two identical capacitively coupled lines have been installed to suppress the unwanted signals in the lower and upper stopbands. The filter has been designed for the U.S. UWB band(3.1~10.6 GHz) with two transmission zeros at 2.4 and 11.1 GHz. The filter has been realized with Low Temperature Core-fired Ceramic(LTCC) green tape which has the dielectric constant of 7.8. Measurement results agree well with HFSS simulation results. Insertion loss less than 0.7 dB and return loss better than 14 dB in the pass band have been measured. The group delay in the center frequency is 0.27 ns and the group delay variation within pass band is less than 0.5 ns. The size of the filter is $6{\times}18{\times}0.6\;mm^3$.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.455-459
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• 2014

We grew the $Li_6Gd(BO_3)_3:Ce^{3+}$ scintillator and determined the scintillation and thermoluminescence properties for X-rays. The emission spectrum of $Li_6Gd(BO_3)_3:Ce^{3+}$ is located in the range of 370~500 nm, peaking at 423 nm an 455 nm, due to the $4f{\rightarrow}5d$ transition of $Ce^{3+}$ ions. The fluorescence decay time of the crystal is composed three components. The fast component is 60 ns (25%), the intermediate component is 787 ns (29%) and the slow component is $5.9{\mu}s$ (46%) of the crystal. The after-glow is caused by the electron and hole traps in the crystal lattice. We determined physical parameters of the traps in the crystal. The thermoluminescence trap are composed two traps. The determined activation energy (E), kinetic order (m) and frequency factor (s) of the first trap are 0.65 eV, 1.01 and $6.9{\times}10^8s^{-1}$. And, the determined activation energy, kinetic order and frequency factor of the second trap are 0.96 eV, 1.79 and $3.1{\times}10^{12 }s^{-1}$, respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.5
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• pp.375-383
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• 2013

Hepatocellular carcinoma (HCC) related to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections is thought to account for more than 80% of primary liver cancers. Both HBV and HCV can establish chronic liver inflammatory infections, altering hepatocyte and liver physiology with potential liver disease progression and HCC development. Cyclophilin A (CypA) has been identified as an essential host factor for the HCV replication by physically interacting with the HCV non structural protein NS5A that in turn interacts with RNA-dependent RNA polymerase NS5B. CypA, a cytosolic binding protein of the immunosuppressive drug cyclosporine A, is overexpressed in many cancer types and often associated with malignant transformation. Therefore, CypA can be a good target for molecular cancer therapy. Because of antiviral activity, the CypA inhibitors have been tested for the treatment of chronic hepatitis C. Nonimmunosuppressive Cyp inhibitors such as NIM811, SCY-635, and Alisporivir have attracted more interests for appropriating CypA for antiviral chemotherapeutic target on HCV infection. This review describes CypA inhibitors as a potential HCC treatment tool that is contrived by their obstructing chronic HCV infection and summarizes roles of CypA in cancer development.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.76-82
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• 2002

This paper presents a quaternary-binary decoder, a quaternary logic current buffer, and a quaternary logic full-adder using current-mode multiple-valued logic CMOS circuits. Proposed full-adder requires only 15 MOSFET, 60.5% and 48.3% decrease of devices are achieved compared with conventional binary CMOS full-adder and Current's full-adder. Therefore, decrease of area and internal nods are achieved. Designed circuits are simulated and verified by HSPICE. Proposed full-adder has 1.5 ns of propagation delay and 0.42㎽ of power consumption. Also, proposed full-adder can easily adapted to binary system by use of encoder, designed decoder and designed current buffer.

• Journal of IKEEE
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• v.27 no.3
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• pp.234-238
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• 2023

In this paper, we propose a time-to-digital converter (TDC) with compensation capability for PVT (process, voltage, and temperature) variations. A typical delay line-based TDC measures time based on the inverter's propagation delay, making it fundamentally sensitive to PVT variations. This paper presents a method to minimize the resolution change of TDC by compensating for the propagation delay caused by the PVT variations. Additionally, it dopts Cyclic Vernier TDC (CVTDC) structure to provide a wide input detection range. The proposed CVTDC with PVT compensation function is designed using a 45nm CMOS process, consumes 8mW of power, offers a TDC resolution of 5 ps, and has an input detection range of about 5.1 ns.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.736-741
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• 2008

Purpose : The incidence of thromboembolic episodes in children with nephrotic syndrome (NS) is low; however, these episodes are often severe. Moreover, both pulmonary thromboembolism (PTE) and renal vein thrombosis (RVT) rarely show clinical symptoms. This study was performed to determine the benefits of routine screening in the detection of thrombosis in childhood NS. Methods : Among 62 children with nephrotic syndrome, a total of 54 children (43 males, 11 females) were included in this study. When the patients experienced their first NS episode, we performed renal Doppler ultrasonography in order to detect RVT. To rule out the possibility of PTE, a lung perfusion scan was performed. Computed tomographic (CT) pulmonary angiography was recommended to patients who showed possible signs of PTE. All patients were evaluated for clinical signs of thrombosis, biochemical indicators of renal disease, as well as clotting and thrombotic parameters. Results : RVT or related clinical symptoms were not observed in any children. Based on the findings of the lung perfusion scans, 15 patients (27.8%) were observed with as a high probability of PTE. We were able to perform a CT pulmonary angiography only on 12 patients, and 5 patients were diagnosed with PTE (prevalence 8.1%). The serum fibrinogen level in the group with PTE was significantly higher ($776.7{\pm}382.4mg/dL$, P<0.05) than that in the group without PTE, and other parameters were not significantly different between each group. Conclusion : Further studies are required for clarifying the role of renal Doppler ultrasonography for the detection of RVT in NS. Children with NS who developed non-specific respiratory symptoms should be evaluated for the diagnosis of PTE. In the management of NS, a lung perfusion scan should be performed at the time of the initial episode of NS regardless of the pulmonary symptoms, since patients having PTE are either often asymptomatic, or present with nonspecific symptoms.

• The Journal of the Petrological Society of Korea
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• v.9 no.1
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• pp.13-28
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• 2000

Chojeong area is mainly composed of the Ogcheon Group which consists of regionally metamorphosed, age-unknown sedimentary rocks. In the northwestern parts, the Group is intruded by the Jurassic Daebo granite and Cretaceous felsic and mafic dykes. The lowermost, Midongsan Formation which consists of milky white impure quartzite, crops out along the anticline axes with N40E trend. Ungyori quartzite Formation is intercalated with quartzite and slate. Miwon Formation is most widely exposed in the area and consists mainly of phyllitic sandy rocks with a thin crystalline limestone bed. Hwajeonri Formation is divided into two parts, pelitic lower and calcareous upper parts, composed with phyllite and slate. Changri and Hwanggangri Formations are typical members of Ogcheon Group, the former bearing coally graphite seams consists mainly of black slate and phyllite with intercalated greenish grey phyllite, the latter is pebble bearing phyllite formation of which matrix and pebbles are variable in compositions and size. Biotite granite, porphyritic granite and two mica granite belong to Jurassic so-called Dabo granite. They intruded the Ogcheon Group forming vast contact metarnophic zone. Quartz porphyry, mafic dyke and felsite intruded along the marginal zone of porphyritic granite batholith and fracture of NS trend. Main structural lineaments in Ogcheon Group shows N25-45E, NS and N30-45W trends. The N25-45E trends are mainly from general ductile deformation during regional metamorphism, showing isoclinal folding, Fl foliations and lithological erosional characters. Some of these trends are due to normal faults. The NS and N30-45W trends represent brittle deformation including faults and joints. In the area of granitic batholith, NS to N30- 45 trends are from the direction of dykes. In the soils of the area, average contents of heavy metal elements such as Cd, Cr, Cu, Pb, and Zn are 0.2, 50.6, 35.5, 27.9, and 93.4 ppm respectively, which are not higher than the average values of natural soils, under the tolerable level. Enrichment Index does not show any heavy metal pollution in the area. Average depths of weathering(5m vs. 2m), porosities(43.94 vs. 51.80), densities(l.29 vs. 1.15), and permeabilities(2.52 vs. 8.07) are comparable in granite areas and in the phyllite areas of Ogcheon Group.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.239-248
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• 2001

The purpose of this study was to analyze risk factors for nosocomial pneumonia in patients admitted to NS ICU, and to provide a basic data to decrease respiratory nosocomial infection rate engendered from medical environments in NS ICU. The study site was the NS ICU at a university hospital located in Seoul, Korea. The subjects were 31 patients diagnosed with nosocomial pneumonia, who were selected from the initial list of 300 potential subjects who had been a) admitted between September 1999 and January 2000, and September 2000 and January 2001, b) resided at the NS ICU over 72 hours. The diagnostic standard of nosocomial pneumonia was based on the nosocomial infection guides of C university hospital. The data were analyzed using frequencies and logistic regression analysis. The sputums obtained from the subjects were cultivated and causal viruses were separated. The results were as follows: 1. The nosocomial pneumonia rate was $10.3\%$. There were 7 types of causal viruses separated from the sputum. and the most prevalent type of virus was MRSA as $62.2\%$. 2. The factors significantly influencing the incidence of nosocomial pneumonia included age, the residential duration at the NS ICU, GCS scores, diabetes mellitus, insertion of tracheal tube and its duration, tracheostomy and its length of insertion, the use of artificial ventilator and the length of its use, and the insertion of naso-gastic tube. The most significant risk factor among these was the insertion of tracheal tube (odds ratio=18.684. $95\%$ CI=6.849-50.974), followed by the use of tracheostomy (odds ratio=15.419, $95\%$ CI=6.615-35.942), the insertion of naso-gastric tube (odds ratio=14.875, $95\%$ CI=6.396-34.595), and the use of artificial ventilator (odds ratio=13.000. $95\%$ CI=5.633­30.001). 3. Regarding the use of the mechanical aids, the insertion of tracheal tube resulted in 12.968 times increase of the nosocomial pneumonia rate, and the use of artificial ventilator lead 6.714 times increase of the nosocomial pneumonia rate. One point increase of the GCS score resulted in the 1.210 times increase of the nosocomial pneumonia rate. For patients who had tracheal tube, tracheostomy, and artificial ventilator, one day increase of their residential duration at NS ICU lead 1.073 times increase of the nosocomial pneumonia rate. 4. In terms of duration of the mechanical aid usage, one day increase in the use of artificial ventilator engendered 1.080 times increase in the nosocomial pneumonia rate. One day increase of the residential duration at the NS ICU lead 1.604 times increase in the nosocomial pneumonia rate. As one point of the GCS score increased, 0.876 times decrease of the nosocomial pneumonia rate was reported. These study findings show that the risk factors significantly influencing the incidence of nosocomial pneumonia include the use of tracheal tube, tracheostomy, naso-gastic tube, and artificial ventilator. It is recommended that nurses working at NS ICU should pay more attention to the patients with these factors as the risky group for the nosocomial pneumonia, and thus make more active efforts to provide nosocomial pneumonia prevention strategies for them. In further studies patients admitted to the different types of ICUs such as internal medicine or surgery unit ICU will be also included, and more wide investigation of nosocomial pneumonia risk factors will be conducted through one-year longitudinal follow up.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.5
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• pp.55-65
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• 2000

In this paper a new architecture of 24-bit two's complement adder is designed by using RB(Redundant Binary) arithmetic which has the advantage of CPF(Carry-Propagation-Free). A MPPL(Modified PPL) XOR/XNOR gate is applied to improve a TC2RB(Two's Complement to RB SUM converter) speed and to reduce the number of transistors, and we proposed two types adder which used a fast RB2TC(RB SUM to Two's Complement converter). The property of two types adder is followings. The improvement of TYPE 1 adder speed is archived through the use of VGS(Variable Group Select) method and TYPE 2 adder is through the use of a 64-bit GCG(Group Change bit Generator) circuit and a 8-bit TYPE 1 adder. For 64-bit, TYPE 1 adder can be expected speed improvement of 23.5%, 25.7% comparing with the CLA and CSA, and TYPE 2 adder can be expected 41.2%, 45.9% respectively. The propagation delay of designed 24-bit TYPE 1 adder is 1.4ns and TYPE 2 adder is 1.2ns. The implementation is highly regular with repeated modules and is very well suited for microprocessor systems and fast DSP units.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.61-70
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• 2018

We developed a Rapid Diagnostic Test (RDT) kit for detecting IgG/IgM antibodies against Zika virus (ZIKV) using monoclonal antibodies to the envelope (E) and non-structural protein 1 (NS1) of ZIKV. These proteins were produced using baculovirus expression vector with Sf9 cells. Monoclonal antibodies J2G7 to NS1 and J5E1 to E protein were selected and conjugated with colloidal gold to produce the Zika IgG/IgM RDT kit (Zika RDT). Comparisons with ELISA, plaque reduction neutralization test (PRNT), and PCR were done to investigate the analytical sensitivity of Zika RDT, which resulted in 100% identical results. Sensitivity and specificity of Zika RDT in a field test was determined using positive and negative samples from Brazil and Korea. The diagnostic accuracy of Zika RDT was fairly high; sensitivity and specificity for IgG was 99.0 and 99.3%, respectively, while for IgM it was 96.7 and 98.7%, respectively. Cross reaction with dengue virus was evaluated using anti-Dengue Mixed Titer Performance Panel (PVD201), in which the Zika RDT showed cross-reactions with DENV in 16.7% and 5.6% in IgG and IgM, respectively. Cross reactions were not observed with West Nile, yellow fever, and hepatitis C virus infected sera. Zika RDT kit is very simple to use, rapid to assay, and very sensitive, and highly specific. Therefore, it would serve as a choice of method for point-of-care diagnosis and large scale surveys of ZIKV infection under clinical or field conditions worldwide in endemic areas.