• Korean journal of applied entomology
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• v.46 no.2
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• pp.319-324
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• 2007

To determine the optimal concentration of fetal bovine serum (FBS) on the growth of insect cells and the multiplicity of viruses, the growth of cells (Sf21 and Bm5) and viruses were examined on the various concentrations of FBS. In view of the viability, growth speed, proliferation of cells and the amount of FBS, the most proper concentration for the cell culture were 7% and 5% for Sf21 and Bm5, respectively. The multiplicity of viruses at the various concentrations of FBS was similar in both cell lines at 5 days post-infection (p.i.). However, it differed significantly at 2 and 3 days p.i. The proper concentration of FBS were 10% and 3% for Sf21 at 2 and 3 days p.i., respectively, and 5% for Bm5 at both 2 and 3 days p.i. These results suggested that the optimal concentration of FBS should be determined according to the used cell lines and viruses for their optimum production.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.43-45
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• 2013

Background: The aim of this epidemiological study was to establish the laterality of breast cancer (BC) and its association with size, receptor status of the primary tumor and bone metastasis (BM) in a local population. Materials and Methods: This retrospective study included cases of BC from Jan-2009 to Dec-2011 who were referred for metastatic work up or follow up survey with Technetium-99m MDP bone scan (BS) to the Nuclear Medicine Department of Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN). A total of 384 patients out of 521 were included and all reviewed for age, primary tumor size (PTS), laterality, receptor status like estrogen receptor (ER) progesterone receptor (PR) and Her-2-Neu receptor, presence or absence of BM with sites of involvement and time interval between diagnosis of BC and appearance of BM. Results: The left to right sided BC proportion was significantly higher than unity (59%:41%; p<0.001). The right sided BC was observed in younger age group (46:52 years; p<0.0001) and with a smaller PTS than the left sided (3.43:4.15 cm; p<0.0001). The patients with BM had relatively higher negative receptor status with a significant predominance of right sided BC. The overall incidence of BM on BS was 28% and relatively higher in right than left breast (33%:24% p=0.068). The average number of BM sites was also significantly greater for the right side (6:4, P<0.0001). The % cumulative risk of BM in right breast was noted at significantly smaller PTS than left side with log rank value of 5.579; p<0.05. The Kaplan Meier survival plot for event free survival of BM in left sided BC was significantly higher than for the right side (log rank value=4.155, p<0.05), with an earlier appearance of BM in right BC. Conclusions: 1) A left sided predominance of BC was seen in local population; 2) right sided BC had a more aggressive behavior with extensive and earlier appearance of BM at relatively younger age, smaller PTS and receptor (s) negativity.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.79-85
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• 2004

In this paper, the RF-ID system for ubiquitous tagging applications has been designed, fabricated and analysed. The RF-ID System consists of passive RF-ID Tag and Reader. The passive RF-ID tag consists of rectifier using zero-bias schottky diode which converts RF power into DC power, ID chip, ASK modulator using bipolar transistor and slot loop antenna. We suggest an ASK undulation method using a bipolar transistor to compensate the disadvantage of the conventional PIN diode, which needs large current Also, the slot loop antenna with wider bandwidth than that of the conventional patch antenna is suggested The RF-ID reader consist of patch array antenna, Tx/Rx part and ASK demodulator. We have designed the RF-ID System using EM and circuit simulation tools. According to the measured results, The power level of modulation signal at 1 m from passive RF-ID Tag is -46.76 dBm and frequency of it is 57.2 KHz. The transmitting power of RF-ID reader was 500 mW

• Journal of IKEEE
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• v.13 no.4
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• pp.103-109
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• 2009

We report an efficient jitter reduction technique in an analog fier-optic link employing a Mach-Zehnder modulator followed by an erbium-doped fiber amplifier. By adjusting the modulator-bias to $0.089V_{\pi}$, we could increase the RF gain up to 10.65 dB for 10 GHz RF signal and reduce the random jitter by 46.5%, max, at an input optical power of -0.11 dBm to the EDFA.

• Journal of Advanced Navigation Technology
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• v.8 no.1
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• pp.57-65
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• 2004

In this paper, keeping pace with light weight, pocket-size, lower-price, we design VCO(Voltage Controlled Oscillator) X/Ku band for using at public RD(Radar Detector) to apply to controlled voltage on base in transistor which used as a oscillator, without using varactor diode in part of VCO tuner. As a result of simulation, we conclude VCO could be have 110 MHz by controlled voltage 4.25 V to 4.80 V and show its output 9.63 dBm at operating frequency, 11.46 GHz, and its phase noise -107.2 dBc at 1 MHz offset frequency. So it turned out suitable performance for commercial use.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.43-46
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• 2012

In this paper, high efficiency power amplifier is implemented with high gain amplifier. Two-stage amplifier using adaptive bias control circuit improve efficiency at low input power. Fixed bias circuit and adaptive bias circuit both have about 76 % efficiency at maximum power level. However amplifier using an adaptive bias control circuit has 70 % at 6 dBm input power level when the amplifier using fixed bias circuit has 50%. The proposed power amplifier using the adaptive bias control circuit can have high efficiency at lower power level.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.77-77
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• 2003

Coculture of HSC with bone marrow-derived mesenchymal stem cells (BM-MSCs) is one of used methods to increase cell numbers before transplant to the patients. However, because of difficulties to purify HSCs after coculture with BM-MSCs, it needs to develop a method to overcome the problem. In the present study, we have examined whether a culture insert placed over a feeder layer might support the expansion of HSCs within the insert. $CD34^+/ $ cells isolated from the umbilical cord blood by using midiMACS were divided into three groups. A group of 1 $\times$ $10^5$ cells were grown on a culture insert without feeder layer (Direct). The same number of HSCs was directly cocultured with BM-MSCs (Contact). The third group was placed onto an insert below which BM-MSCs were grown (Insert). To distinguish feeder cells from HSCs, BM-MSCs was pre-labeled fluorescently with PKH26 and 1 $\times$ $10^5$ cells were seeded in the culture dishes. After culture for 13 days, the expansion factor (x) of HSCs that were grown without feeder layer (Direct) was $26.6 \pm 8.4.$ In contrast, the number of HSCs directly cocultured with feeder layer was 59.6 $\pm$ 0.5 and that of HSCs cultured onto an insert was $46.9 \pm 8.4.$ The percentage of BM-MSCs cells remained being fluorescent was $97.9 \pm 0.3%$ after culture. Immune-phenotypically large proportion of cultured cells were founded to be differentiated into myeloid/monocyte progenitor cells. The ability of BM-MSCs, fetal lung, cartilage and brain tissue cells to support ex vivo expansion of HSCs was also examined using the insert. After 11 days of coculture with each of these cells, the expansion factor of HSCs was 15.0, 39.0, 32.0 and 24.0, respectively. Based upon these observations, it is concluded that the coculture method using insert is very effective to support ex vivo expansion of HSCs and to eliminate the contamination of other cells used to coculture wth HSCs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.1 s.12
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• pp.38-46
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• 2007

In this paper an X-band low phase noise HBT oscillator using a planar type MMIC resonator is designed. The chip area of the proposed resonator shows a quarter of the conventional hair-pin resonator using distributed transmission lines. The measurement results show oscillation frequency of 8.295 GHz, the power output of 4.8 dBm, and phase noise characteristic of -106.8 dBc/Hz and -121.7 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively.

• Korean Journal of Materials Research
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• v.14 no.9
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• pp.655-658
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• 2004

Lithium ferrites are a low-cost material which have been prominent in the high frequency core industry because of their excellent temperature performance and high squareness ratio. In order to develope the lithium ferrites with the high squareness and low coercive force, the ferrites of $Li_{0.48}Bi_{0.02}Ni_{0.04}Fe_{2.46-x}O_4$ were investigated the by varying composition, temperature and frequency. Electric loss of the Li-ferrite was lowered with the substitution of $Mn_{2}O_3$. The addition of $Mn_{2}O_3$ increased the magnetic induction (Bm&Br) but decreased the coercive force (Hc) and the squareness ratio (R=Br/Bm). Also, the Br value was stable at environmental temperature variation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.45-49
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• 2009

In this paper, a direct down conversion LNA/Mixer has been designed and tested for 900Mhz UHF RFID application. The designed circuit has been implemented in 0.18um CMOS technology with 3.3V operation. In this work, a common gate input architecture has been used to cope with the higher input self jamming level. This LNA/Mixer is designed to support two operating modes of high gain mode and low gain mode according to the input jamming levels. The measured results show that the input referred P1dBs are 4dBm of high gain mode and 11dBm of low gain mode, and the conversion gains are 12dB and 3dB in high and low gain mode respectively The power consumptions are 60mW for high gain mode and 79mW for low gain mode. The noise figures are 16dB and 20dB in high gain mode and low gain mode respectively.