• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.8
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• pp.397-400
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• 2006

An optimized iron core structure of stimulating coil are presented in order to control the induced electric field distribution using the Continuum Design Sensitivity Analysis (CDSA) combined with a commercially available generalized finite element code (OPERA). The results show that a Figure-Of-Eight (FOE) coil as well as a circular coil with the proposed iron core structure can increase induced electric field intensity by more than two times and make better field localization, compared with those of existing stimulation coil with a air core. After considering manufacturing constraints, a practical iron core structure based on the proposed optimized one is proposed and its performance is analyzed.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.420-422
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• 2005

TMC (Tautomycetin) is a liner polyketide immunosuppressive antifungal compound produced by Streptomyces spp. Inhibition of T cell proliferation with TMC was observed highly efficient at 100-fold lower than those needed to achieve maximal inhibition with cyclosporin A. To elucidate the biosynthetic pathway of TMC, a genomic DNA library was constructed using a E. coil-Streptomyces shuttle cosmid vector, pOJ446. The DNA libraries were screened by colony blot hybridization using several polyketide ${\beta}-ketosynthase$ (KS) probes amplified from TMC-producing Streptomyces genomic DNA using polymerase chain reaction (PCR), of which the degenerate primers were designed based on the highly conserved sequences present in KS domains of various type I polyketide synthase genes in Streptomyces species. This library construction and screening approach led to the isolation of several positive cosmid clones representing type I polyketide biosynthetic gene clusters. In addition, a Streptomyces regulatory gene called afsR2 (a global regulatory gene stimulating antibiotic production in both S. coelicolor and S. lividans) was successfully integrated into the TMC-producing Streptomyces chromosome via E. coil-Streptomyces heterologous conjugation mehtod. The more detailed results of production improvement and genetic characterization of TMC-producing Streptomyces spp. will be discussed.

• Journal of Magnetics
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• v.17 no.1
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• pp.27-32
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• 2012

Transcranial magnetic stimulation requires an electric field composed of dozens of V/m to achieve stimulation. The stimulation system is composed of a stimulation coil to form the electric field by charging and discharging a capacitor in order to save energy, thus requiring high-pressure kV. In particular, it is charged and discharged in capacitor to discharge through stimulation coil within a short period of time (hundreds of seconds) to generate current of numerous kA. A pulse-type magnetic field is formed, and eddy currents within the human body are triggered to achieve stimulation. Numerous pulse forms must be generated to initiate eddy currents for stimulating nerves. This study achieved high internal pressure, a high number of repetitions, and rapid switching of elements, and it implemented numerous control techniques via introduction of the half-bridge parallel load method. In addition it applied a quick, accurate, high-efficiency charge/discharge method for transcranial magnetic stimulation to substitute an inexpensive, readily available, commercial frequency condenser for a previously used, expensive, high-frequency condenser. Furthermore, the pulse repetition rate was altered to control energy density, and grafts compact, one-chip processor with simulation to stably control circuit motion and conduct research on motion and output characteristics.

• Journal of Microbiology
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• v.40 no.1
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• pp.77-81
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• 2002

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic hematspoietic growth factor involved in the development of myeloid cells from bone marrow, and an activator of mature myeloid cells functioning in a variety of antimicrobial and inflammatory responses. Recently, recombinant GM-CSF is increasingly under clinical study for treatment of various diseases including cancer, infectious diseases and hematopoietic diseases as well as for an immune response modulator, In this study, we constructed a recombinant human GM-CSF (rhGM-CSF) expression plasmid with a pelB leader sequence and His. Tag under T7 promoter control. The expression construct was shown to produce a recombinant protein of 20 kDa in the 8M urea preparation, indicating the rhGM-CSF may be expressed as an insoluble inclusion form. The 20 kDa recombinant protein in 8M urea was transformed into the water-so1ub1e form by dialysis against PBS buffer (phosphate buffered saline). The soluble rhGM-CSF protein was shown to stimulate colony formation and cell proliferation in vitro, indicating that the rhGM-CSF could be refolded into its native form to show colony stimulating activity.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.615-620
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• 2018

Evaluation of clinical usefulness of current perception threshold test and vibration sense perception threshold test in diagnosing the diabetic poly-neuropathy patients is one of the diagnosis methods for diabetic poly-neuropathy. Up to the present, some diagnostic methods were used for diabetic poly neuropathy patients. For example, there are neuropathy impairment score test of lower limbs, nerve conduction test, cooling detection threshold test, heat-pain threshold test and so on. However, most of the above tests require very expensive cost and take a lot of time in test. In this paper, a new apparatus estimating vibration sense ability is introduced. For this purpose, the VCM(voice coil motor) stimulating patient's peripheral nerve and current amplifier were manufactured. Also, softwares sensing and driving the vibration detection threshold test in order to measure the quantitative vibration sensory levels in diabetic poly-neuropathy patients were developed.

• Journal of Biomedical Engineering Research
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• v.22 no.2
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• pp.139-144
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• 2001

자기 신경자극기는 신경의학, 재활의학을 포함한 많은 임상의학 분야에서 널리 쓰이고 있다. 자기 신경자극기는 전력소모가 크고 고압 전원이 필요한 이유 때문에 단채널 시스템만이 임상환경이나 연구환경에서 쓰여 왔었다. 본 논문에서는 4채널 자기 신경자극기 개발을 소개하였다. 고압 커패시터를 충전하는데 있어서 단계적 충전방식을 사용하여 작은 크기의 직류 전원장치로 다채널 시스템을 구현하였고, 채널별로 서로 다른 자극 프로토콜로 자극 코일을 구동할 수 있는 다채널 제어시스템을 구성하였다. 개발된 시스템은 신경계통 장애가 있는 환자들의 재활이나 자기적인 침술 등 다양한 기능적 자기 자극에 활용될 수 있을 것으로 기대된다.

• Annals of Clinical Neurophysiology
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• v.5 no.2
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• pp.187-191
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• 2003

Purpose: MEPs elicited by transmagnetic stimulations of the motor cortex are facilitated by voluntary muscle contraction. We evaluated the effects of the imagination of the movements on latencies of MEPs and reciprocal inhibition by using transmagnetic stimulations. Methods: Twenty two healthy volunteers(eight men and fourteen women) were studied. TMSs were delivered at rest and during imagining abducting or adducting right thumb. A stimulator with a round coil and a fixed intensity of 80% of maximum was used to evoke MEPs. MEPs were evoked by magnetic stimulations over the scalp and cervical spine(C7-T1), and central motor conduction times(CMCT) were calculated by subtracting the latency of compound muscle action potentials(CMAPs) obtained by stimulating over the cervical spine from that obtained by stimulating over the scalp. The motor evoked potentials were recorded from right abductor pollicis brevis muscle(APB) and adductor pollicis muscle(AP) simultaneously. Results: Imagination of abduction resulted in a shortened latency of the CMAPs in APB, and a prolonged latency in AP. Imagination of adduction resulted in a shortened latency in AP, and a prolonged latency in APB. But the imagination caused no significant change in the latency of CMAPs elicited by stimulation over cervical spine. Therefore, the changes of the CMCTs account for these latency changes with imagination of movement. With the imagination of abduction, there are significant reduction of the CMCT's in APB(10.8%) and prolongation in AP(5.8%). On the other hand, with the imagination of adduction, prolongation of the CMCT's in APB(7.3%) and reduction in AP(5.9%) were observed. Conclusion: These findings indicate that imagination of muscle contraction increases the excitability of the human corticospinal system. Reciprocal inhibition may be accountable for the prolonged latency in the antagonist muscle.

• Journal of Magnetics
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• v.17 no.1
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• pp.36-41
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• 2012

The transcranial magnetic stimulation recharges the energy storing condenser, and sends the stored energy in the condenser to the pulse shaping circuit, which then delivers it to the stimulating coil. The previous types of transcranial magnetic stimulation required a booster transformer, secondary rectifier for high voltages and a condenser for smooth type. The energy storing condenser is recharged by switching the high-voltage direct current power. Loss occurs due to the resistance in the recharging circuit, and the single-pulse output energy in the transcranial magnetic stimulation can be changed because the recharging voltage cannot be adjusted. In this study a booster transformer, which decreases the volume and weight, was not used. Instead, a current resonance inverter was applied to cut down the switching loss. A transcranial magnetic stimulation, which can simultaneously alter the recharging voltage and pulse repeats, was used to examine the output characteristics.