Ni-Fe 합금 도금층의 기계적 물성에 영향을 미치는 도금인자

고영권,임태홍,이재호,Ko, Yeong-Kwon,Yim, Tai-Hong,Lee, Jae-Ho 한국마이크로전자및패키징학회 2008 마이크로전자 및 패키징학회지 Vol.15 No.4

전기도금법에 의한 니켈-철 합금 도금층은 전류인가방식, 전류밀도, 첨가제, 도금 욕에서 철과 니켈에 농도비 등과 같은 공정 변수에 따라 그 조성이 민감하게 변화하고 특히 전류인가방식에 따라 도금 층의 조성과 기계적인 특성이 달라지는 경향을 보이고 있다. 본 연구에서는 전류의 인가방식과 전류밀도 변화에 따른 경도, 내마모성, 인성,표면 거칠기 및 잔류응력 등의 기계적인 물성의 변화를 연구하였다. 전류인가방식을 직류에서 펄스전류로 변환시킴에 따라 인장강도가 15% 증가하였으며, 잔류음력이 10% 감소하였고, 내마모성이 30% 향상되었다. The mechanical properties of Ni-Fe alloy were varied with the current type, current density and bath conditions such as concentrations and temperature. The effect of electroplating parameters on the surface hardness, mechanical strength, residual stress and wear properties were investigated. The mechanical properties of electrodeposits with PC plating is superior to those with DC plating. Ni-Fe electrodeposits with PC has approximately 50% lower residual stress than that of DC plating. The tensile strength of PC electroplated specimen was 15% higher than that of DC electroplated specimen. The wear resistance of PC specimen was 30% improved relative to that of DC specimen.

Acanthosis Nigricans as a Clinical Predictor of Insulin Resistancein Obese Children

고영권,이재희,김은영,문경래 대한소아소화기영양학회 2016 Pediatric gastroenterology, hepatology & nutrition Vol.19 No.4

Purpose: This study aimed to evaluate the utility of acanthosis nigricans (AN) severity as an index for predicting insulin resistance in obese children.Methods: The subjects comprised 74 obese pediatric patients who attended the Department of Pediatrics at Chosun University Hospital between January 2013 and March 2016. Waist circumference; body mass index; blood pressure; fasting glucose and fasting insulin levels; lipid profile; aspartate transaminase, alanine transaminase, glycated hemo-globin, C-peptide, and uric acid levels; and homeostatic model assessment insulin resistance (HOMA-IR) and quanti-tative insulin check sensitivity index (QUICKI) scores were compared between subjects with AN and those without AN. Receiver operating characteristic curves were used to investigate the utility of the AN score in predicting insulin resistance. HOMA-IR and QUICKI were compared according to AN severity.Results: The With AN group had higher fasting insulin levels (24.1±21.0 mU/L vs. 9.8±3.6 mU/L, p<0.001) and HOMA-IR score (5.74±4.71 vs. 2.14±0.86, p<0.001) than the Without AN group. The AN score used to predict insulin resistance was 3 points or more (sensitivity 56.8%, specificity 83.9%). HOMA-IR scores increased with AN severity, from the Without AN group (mean, 2.15; 95% confidence interval [CI], 1.72-2.57) to the Mild AN (mean, 4.15; 95% CI, 3.04-5.25) and Severe AN groups (mean, 7.22; 95% CI, 5.08-9.35; p<0.001).Conclusion: Insulin resistance worsens with increasing AN severity, and patients with Severe AN (AN score ≥3) are at increased risk of insulin resistance.

만성요통 치료를 위한 중재적 요법

고영권,김윤희 대한의사협회 2012 대한의사협회지 Vol.55 No.6

Chronic low back pain has become a major public health problem in Korea. The lifetime prevalence of low back pain has been reported to be as high as 90%. The prevalences of discogenic pain, facet joint pain, and sacroiliac joint pain are 42%, 30%, and 18%, respectively. Increasing age is associated with a decreasing probability of discogenic pain but increasing probabilities of facet joint pain and sacroiliac joint pain as the source of low back pain. Physical examination of low back pain is limited and imaging may lack objective clues. Diagnostic interventions allow us to determine the etiology of back pain. Techniques include lumbar disc stimulation,facet joint block, medial branch block, and sacroilliac joint block. Initial therapy includes modification of activity, pharmacological analgesic therapy, and education of patients. In patients with chronic low back pain, a multimodal and interdisciplinary treatment approach is necessary. Use of interventional treatments for chronic low back pain are increasing but their utilization remains uncertain or controversial. Therefore, management of patients with chronic and disabling low back pain remains a clinical challenge.

Clinical Experiences on the Effect of Scrambler Therapy for Patients with Postherpetic Neuralgia

고영권,이호영,이왕용 대한통증학회 2013 The Korean Journal of Pain Vol.26 No.1

Postherpetic neuralgia (PHN) is a debilitating complication of herpes zoster, especially in elderly and comorbid patients. Unfortunately, the currently available treatments have shown limited efficacy and some adverse events that are poorly tolerated in elderly patients. Scrambler Therapy, proposed as an alternative treatment for chronic neuropathic pain recently, is a noninvasive approach to relieve pain by changing pain perception at the brain level. Here, we report our clinical experiences on the effect of Scrambler Therapy for three patients with PHN refractory to conventional treatment.

신경병성 통증 치료를 위한 약물요법

고영권,김윤희 대한의사협회 2012 대한의사협회지 Vol.55 No.6

Neuropathic pain has recently been defined as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system”. Neuropathic pain is a debilitating chronic condition that remains very difficult to treat and challenging to manage. Tricyclic antidepressants (amitryptiline, nortriptyline, imipramine), selective serotonin and norepinephrine reuptake inhibitors (duloxetine, venlafaxine), anticonvulsants (gabapentin, pregabalin), and 5%lidocaine patches have demonstrated efficacy in neuropathic pain and are recommended as first-line medications. In patients who fail to respond to these first-line medications alone and/or in combination, opioid analgesics or tramadol can be used as a second-line treatment alone or in combination with one of the first-line medications. Opioid analgesics and tramadol can also be considered for first-line use in selected clinical circumstances. Other pharmacological therapeutic options include selective serotonin reuptake inhibitors, antiepileptic drugs (levetiracetam,lacosamide, lamotrigine, valproic acid), cannabinoids, high concentration capsaicin patch, and botulinum toxin A. Medication selection should be individualized, with side effects taken into consideration as well as potential beneficial or deleterious effects on comorbidities, and whether or not prompt onset of pain relief is necessary.

십전대보탕(十全大補湯)이 CD4+ 및 CD8+ T세포수(細胞數)에 미치는 영향(影響)

고영권,류봉하,박동원,류기원,Ko, Young-Kwon,Ryu, Bong-Ha,Park, Dong-Won,Ryu, Ki-Won 대한암한의학회 1998 大韓癌韓醫學會誌 Vol.4 No.1

In order to research the effect of Sipjundaebotang on the immune respons of CD4+ T cell and CD8+ T cell in rats, author have performed this experimental study. Experimental groups are divided into 5 groups(intact, control, sample I, sample II, sample III). Normal group was intact, control group was administrated normal saline 2cc for 5 days, sample I was administrated low concentration of Sipjundaebotang(100/3100pack/ml) 2cc for 5 days, sample II was administrated middle concentration of Sipjundaebotang(500/3100pack/ml) 2cc for 5 days, sample III was administrated high concentration of Sipjundaebotang(2500/3100pack/ml) 2cc for 5 days. WBC, Lymphocyte, CD4+ T cell in the blood, spleen, axillary node and CD8+ T cell in the blood, spleen and axillary node were determined. The results was as follows: 1. WBC count in blood was significantly decrcased in the control, sample I, II, III groups as compared with the normal group. 2. Lymhocyte count in the blood was significantly decreased in the control, sample I, II groups as compared with the normal group. 3. CD4+ T cell count in the blood was significantly increased dose-dependently in the sample I, II, III groups as compared with the normal group. 4. CD4+ T cell count in the spleen was significantly increased in the sample I, II, III groups as compared with the normal group. 5. CD4+ T cell count in the axillary node was significantly increased in the sample III group as compared with the normal group, however significantly decreased in the sample I, II groups as compared with the normal group. 6. CD8+ T cell count in the blood was significantly increased in the sample III groups as compared with the normal group. 7. CD8+ T cell count in the spleen was significantly increased in the sample I, II, III groups as compared with the normal group. but there was no differences in the sample groups. 8. CD8+ T cell count in the axillary node was decreased in the sample I, II groups as compared with the normal group.

Ni-Fe의 도금 층의 조성과 표면 형상에 영향을 미치는 도금인자들에 관한 연구

고영권,임태홍,이재호,Ko, Yeong-Kwon,Yim, Tai-Hong,Lee, Jae-Ho 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.3

Ni-Fe 전해도금 시 전류밀도, 펄스주기와 전류인가 방식, 도금욕의 Fe 이온의 농도, 첨가제 등의 인자들이 도금 층의 조성, 표면형상, 표면 경도에 미치는 영향에 관하여 연구하였다. 시편에 가해지는 전류밀도, 전류인가방식과 Fe이온의 농도를 변화시킴으로써 Ni-Fe의 도금 층 내에 Ni-Fe의 조성을 조절하는 것이 가능하였고 또한 첨가제의 양을 변화시킴으로써 표면형상이 변화됨을 확인하였다. PC를 사용한 경우 직류를 사용한 경우보다 높은 $550{\sim}600Hv$의 경도값을 얻을 수 있었다. 사카린을 첨가한 경우 도금층의 잔류응력을 낮추어 균열이 없는 도금층을 얻었다. Ni-Fe의 단면의 조성을 분석함으로써 도금 층의 두께에 따른 조성의 변화를 확인하였다. Nickel iron (Ni-Fe) alloy coating was investigated. The effects of the current density, current type, pulse duration and bath compositions on the morphologies and surface hardness of nickeliron deposits as well as the chemical compositions were investigated. The morphologies, surface hardness and chemical compositions of nickel-iron deposits were varied with current density, current type and bath compositions. The surface hardness was increased up to $550{\sim}600Hv$ when PC plating was employed. Crackless coating was obtained when saccharin was added. The change of composition with thickness was analyzed with EDS and FESEM.

Effects of Dextrose Supplementation on Chloral Hydrate Sedation: A Double-Blinded, Randomized, Prospective Study

고영권,강한길,조영국 전남대학교 의과학연구소 2023 전남의대학술지 Vol.59 No.3

Sedation plays a crucial role in successful pediatric imaging, and chloral hydrate is commonly used for this purpose. However, the challenges associated with chloral hydrate administration, such as its unpleasant taste and potential induction of vomiting, remain a concern. Sweet oral solutions have emerged as potential solutions for reducing distress and providing analgesia. This study compared the efficacy of dextrose combined with chloral hydrate with that of conventional sedation methods. This prospective, double-blind, randomized controlled clinical study enrolled 160 pediatric outpatients scheduled for echocardiography. Chloral hydrate syrup (100 mg/mL) was supplemented with a dextrose solution (dextrose group) or distilled water (control group) in a 1:10 volume ratio. The sedation achievement time, Skeie scale score, revised Face, Legs, Activity, Cry, and Consolability (FLACC) score, and side effects (nausea, vomiting, hypoxia, and respiratory depression) were assessed. No significant difference in average time to achieve sedation was observed between the dextrose and control groups (24.4±17.8 vs. 24.7±17.1 min, p=0.92). Both groups demonstrated similar levels of sedation according to the Skeie scale and mean revised FLACC score. Although the occurrence rates of nausea and vomiting had no significant differences, the dextrose group had no cases of vomiting in children aged >24 months compared to the control group, which had three cases (30%). In conclusion, the addition of dextrose to chloral hydrate did not significantly affect sedation time, anxiety, pain reduction, or occurrence of gastrointestinal complications during sedation.

Simvastatin reduces adrenal catecholamine secretion evoked by stimulation of cholinergic nicotinic and angiotensinergic AT1 receptors

고영권,김기환,최미성,고영엽,임동윤 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.3

We investigated the influence of simvastatin, astatin, on the secretion of catecholamines (CA) in ratadrenal glands, and clarified its action mechanism. Simvastatinsuppressed acetylcholine (ACh)-evoked CArelease in a dose- and time-dependent fashion. In thepresence of simvastatin, CA secretion evoked by 1.1-dimethyl-4-phenyl piperazinium iodide (DMPP), angiotensinII, high K?, veratridine, and Bay-K-8644 was timedependentlyinhibited. However, in the simultaneouspresence of simvastatin and Nx-nitro-L-arginine methylester hydrochloride, CA secretion evoked by angiotensin IIand DMPP recovered to control levels. Adrenal NO releasewas increased by simvastatin-treatment. Simvastatin-inhibitedCA secretion was not affected by treatment withmevalonate. Pravastatin did not influence ACh-evoked CAsecretion, while atorvastatin reduced it. In the simultaneouspresence of simvastatin and fimasartan, ACh-induced CArelease was markedly reduced compared to that offimasartan-treatment alone. We present the first evidencethat simvastatin reduces adrenal CA secretion induced bystimulation of nicotinic and AT1-receptors. Simvastatininducedinhibition seems to involve reducing the influx ofboth Ca2? and Na? into adrenochromaffin cells, partly viathe elevation of NO production by NO synthase activation,without inhibition of 3-hydroxy-methylglutaryl coenzymeA reductase. Co-administration of simvastatin andfimasartan may be clinically helpful for the treatment ofcardiovascular diseases.

Antinociceptive effect of phenyl N-tert-butylnitrone, a free radical scavenger, on the rat formalin test

고영권,Ann Misun Youn,홍부휘,김윤희,신용섭,강포순,윤건정,이원형 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.62 No.6

Background: Reactive oxygen species (ROS) such as superoxide radicals, hydrogen peroxide, nitric oxide, and nitroperoxide, cause oxidative stress which interferes with normal cell functioning, resulting in cell damage. It is reported to be associated with chronic pain, especially neuropathic pain, and inflammatory pain. ROS is also closely related to central sensitization. Therefore, this study was designed to explore the effects of Phenyl N-tert-butylnitrone (PBN), an ROS scavenger, in acute, continuous, and increasing pain caused by central sensitization. Methods: Male Sprague-Dawley rats were divided into 2 groups, an intraperitoneal group (IP) and an intrathecal group (IT), and once again divided into an experimental group and a control group. The experimental group was injected with Phenyl N-tert-butylnitrone (PBN), a free radical scavenger, either intraperitoneally or intrathecally. After inducing pain by injecting formalin into the hind paw, pain behaviors were measured. Lumbar enlargement immmunohistochemistry was performed to assess nitrotyrosine, an oxidative stress marker, to identify the degree of protein nitration. Results: Both experimental groups of IP and IT showed statistically significant decreases in the number of flinches compared to the control group in phase 1 and 2. Immunohistochemical evaluation in the control group revealed an increase in nitrated proteins in the gray matter of the lumbar spinal cord, but a significant decrease in nitrated proteins in the gray matter of lumbar spinal cord of the experimental group. Conclusions: Intraperitoneal and intrathecal administration of PBN decreases analgesic behaviors, allowing us to believe that ROS is mainly responsible for acute pain and central sensitization.