• Title/Summary/Keyword: Delayed injection

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An Experimental Study of Silica Particle Growth in a Coflow Diffusion Flame Utilizing Light Scattering and Local Sampling Technique (II) - Effects of Diffusion - (광산란과 입자포집을 이용한 동축류 확산화염 내의 실리카 입자의 성장 측정(II) - 확산의 영향 -)

  • Cho, Jaegeol;Lee, Jeonghoon;Kim, Hyun Woo;Choi, Mansoo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.9
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    • pp.1151-1162
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    • 1999
  • The effects of radial heat and $H_2O$ diffusion on the evolution of silica particles in coflow diffusion flames have been studied experimentally. The evolution of silica aggregate particles in coflow diffusion flames has been measured experimentally using light scattering and thermophoretic sampling techniques. The measurements of scattering cross section from $90^{\circ}$ light scattering have been utilized to calculate the aggregate number density and volume fraction using with combination of measuring the particle size and morphology through the localized sampling and a TEM image analysis. Aggregate or particle number densities and volume fractions were calculated using Rayleigh-Debye-Gans and Mie theory for fractal aggregates and spherical particles, respectively. Flame temperatures and volumetric differential scattering cross sections have been measured for different flame conditions such as inert gas species, $H_2$ flow rates, and burner injection configurations to examine the relation between the formation of particles and radial $H_2O$ diffusion. The comparisons of oxidation and flame hydrolysis have also been made for various $H_2$ flow rates using $N_2$ or $O_2$ as a carrier gas. Results indicate that the role of oxidation becomes dominant as both carrier gas($O_2$) and $H_2$ flow rates increases since the radial heat diffusion precedes $H_2O$ diffusion in coflow flames used in this study. The effect of carrier gas flow rates on the evolution of silica particles have also been studied. When using $N_2$ as a carrier gas, the particle volume fraction has a maximum at a certain carrier gas flow rate and as the flow rate is further increased, the hydrolysis reaction Is delayed and the spherical particles finally evolves into fractal aggregates due to decreased flame temperature and residence time.

Transcriptional Analysis for Oral Vaccination of Recombinant Viral Proteins against White Spot Syndrome Virus (WSSV) in Litopenaeus vannamei

  • Choi, Mi-Ran;Kim, Yeong-Jin;Jang, Ji-Suk;Kim, Sung-Koo
    • Journal of Microbiology and Biotechnology
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    • v.21 no.2
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    • pp.170-175
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    • 2011
  • This study was carried out for the molecular level identification of recombinant protein vaccine efficacy, by oral feeding against white spot syndrome virus infection, with the comparison of viral mRNA transcriptional levels in shrimp cells. For the determination of WSSV dilution ratio for the vaccination experiment by oral feeding, in vivo virus titration was carried out using different virus dilutions of virus stock ($1{\times}10^2$, $2{\times}10^2$, and $1{\times}10^3$). Among the dilution ratios, $2{\times}10^2$ diluted WSSV stock was chosen as the optimal condition because this dilution showed 90% mortality at 10 days after virus injection. Recombinant viral proteins, rVP19 and rVP28, produced as protein vaccines were delivered in shrimps by oral feeding. The cumulative mortalities of the shrimps vaccinated with rVP19 and rVP28 at 21 days after the challenge with WSSV were 66.7% and 41.7%, respectively. This indicates that rVP28 showed a better protective effect against WSSV in shrimp than rVP19. Through the comparison of mRNA transcriptional levels of viral genes from collected shrimp organ samples, it was confirmed that viral gene transcriptions of vaccinated shrimps were delayed for 4~10 days compared with those of unvaccinated shrimps. Protection from WSSV infection in shrimp by the vaccination with recombinant viral proteins could be accomplished by the prevention of entry of WSSV due to the shrimp immune system activated by recombinant protein vaccines.

Sopung-san Extract Enhances healing potential on Full-thickness Skin Wound in Rats: Role of VEGF and TGF-β1 (흰쥐의 전층피부상처 동물모델에서 소풍산(消風散)이 VEGF 및 TGF-β1발현에 미치는 영향)

  • Kim, Bum Hoi
    • Herbal Formula Science
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    • v.25 no.2
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    • pp.123-134
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    • 2017
  • Wounds are commonly created during almost every kind of surgery, trauma and skin diseases. Delayed wound healing affects a plenty of patients and requires prolonged treatments that seriously reduce the quality of life for patients. Skin damage involving large areas or great severity can lead to disability or even death. Wound healing involves a complicated series of actions, of various tissues and cell lineages, concerning inflammation, migration, proliferation, reepithelialization, and remodeling. Sopung-san is reported to have anti-inflammatory effect and has been used for various skin diseases such as allergic dermatitis and atopic dermatitis. In this study, the hypothesis that oral treatment with Sopung-san could enhances healing potential on rat full thickness skin wounds was tested. Twenty young male Sprague-Dawley rats were used for the studies. A full-thickness skin wound was made on the dorsal skin of the rats. Either Sopung-san water extract (SPS) or saline (Control) was orally administrated every day. The wound area was measured and the percentages of wound contraction, wound healed and wound epithelization were calculated. Wound tissue samples were excised following injection for histopathological and immunohistological examination. Wound area in rats of SPS group significantly was decreased compared to Control. SPS group showed significant promotion of wound healing compared to Cotrol group in the percentages of wound contraction, wound healed and wound epithelization. Histopathological examination revealed that SPS induces neo-vascularization potential in wound healing process. SPS treatment in rats significantly accelerated cutaneous wound healing in the neo-vascularization process by increasing VEGF and $TGF-{\beta}1$ synthesis. The results suggest that Sopung-san affects key cellular processes responsible for wound repair and point to a unique potential for this molecule in the therapy of skin wounds, particularly as an angiogenic agent.

A Case of Epidural Blood Patch to Treat Headache Due to Spontaneous Intracranial Hypotension -A case report- (경막외 혈액봉합술을 이용한 자연성 두개내 저압성 두통 환자의 치험 1예 -증례 보고-)

  • Park, Soo-Seog;Jang, Yeon;Cho, Eun-Chung;Jee, Seung-Eun;Song, Ho-Kyung;Jung, Sung-Woo
    • The Korean Journal of Pain
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    • v.11 no.2
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    • pp.338-342
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    • 1998
  • Postural headache due to spontaneous intracranial hypotension occurs without any diagnostic lumbar puncture, myelography, cranial or spinal injury, or spinal anesthesia. The clinical characteristics of the syndrome are disappearance of the headache or a notable decrease in its severity with recumbency, the finding of meningeal enhancement and subdural fluid collection on brain MRI, the pleocytosis and the increased CSF protein concentration. We report a case of a 40-year-old woman who exhibited the signs and symptoms of postural headache due to low CSF pressure. Her headache started suddenly at the occiput and radiated to frontal head. Magnetic resonance imaging (MRI) of her brain showed enhancement of the meninges and subdural fluid collection. Intrathecal radionuclide cisternography showed the delayed appearance of the isotope in the cranium and the minimal CSF leak at the left upper thoracic region. Her headache was relieved completely after a lumbar (L2-L3) epidural injection of 12 ml of autologous blood and remained asymptomatic.

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Sweet Bee Venom Pharmacopuncture May be Effective for Treating Sexual Dysfunction

  • Lee, Pavel;Yu, Junsang
    • Journal of Pharmacopuncture
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    • v.17 no.3
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    • pp.70-73
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    • 2014
  • Sexual dysfunction (SD) is a health problem which occurs during any phase of the sexual response cycle that keeps the individual or couple from experiencing satisfaction from the sexual activity. SD covers a wide variety of symptoms like in men, erectile dysfunction and premature or delayed ejaculation, in women, spasms of the vagina and pain with sexual intercourse, in both sexes, sexual desire and response. And pharmacopuncture, i.e. injection of subclinical doses of drugs, mostly herb medicine, in acupoints, has been adopted with successful results. This case report showed the effect of bee venom on SD. A 51-year-old male patient with SD, who had a past history of taking Western medication to treat his SD and who had previously undergone surgery on his lower back due to a herniated disc, received treatments using pharmacopuncture of sweet bee venom (SBV) at Gwanwon (CV4), Hoeeum (CV1), Sinsu (BL23), and Gihaesu (BL24) for 20 days. Objectively, the patient showed improvement on most items on the International Index for Erectile Dysfunction (IIEF) like 28 to 29 out of perfect score 30 for erectile function, 10 to 10 out of perfect score 10 for orgasmic function, 6 to 8 out of perfect score 10 for sexual desire, 10 to 13 out of perfect score 15 for satisfaction with intercourse, and 6 to 8 out of perfect score 10 for overall satisfaction; subjectively, his words, the tone of his voice and the look of confidence in his eyes all indicated improvement. Among the variety of effects of SBV pharmacopuncture, urogenital problems such as SD may be health problems that pharmacopuncture can treat effectively.

Intravenous Magnesium Infusion for the Prevention of Symptomatic Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

  • Jeon, Jin-Sue;Sheen, Seung-Hun;Hwang, Gyo-Jun;Kang, Suk-Hyung;Heo, Dong-Hwa;Cho, Yong-Jun
    • Journal of Korean Neurosurgical Society
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    • v.52 no.2
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    • pp.75-79
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    • 2012
  • Objective : The study examined the difference in the incidence of symptomatic cerebral vasospasm with magnesium supplementation in aneurysmal subarachnoid hemorrhage (SAH) in a Korean population. Methods : This retrospective analysis was performed in 157 patients diagnosed with aneurysmal SAH from January 2007 to December 2011 at a single center. Seventy patients (44.6%) received a combination treatment of nimodipine with magnesium and 87 patients (55.4%) received only nimodipine. A matched case-control study using propensity scores was conducted and 41 subjects were selected from each group. A dosage of 64 mmol/day of magnesium was administrated. Results : The infusion of magnesium did not reduce the incidence of symptomatic cerebral vasospasm (n=7, 17.1%, p=0.29) compared with simple nimodipine injection (n=11, 26.8%). The ratios of good clinical outcome (modified Rankin scale 0-2) at 6 months were similar, being 78% in the combination treatment group and 80.5% in the nimodipine only group (p=0.79). The proportions of delayed cerebral infarction was not significantly lower in patients with combination treatment (n=2, 4.9% vs. n=3, 7.3%; p=0.64). There was no difference in the serum magnesium concentrations between the patients with symptomatic vasospasm and without vasospasm who had magnesium supplementation. No major complications associated with intravenous magnesium infusion were observed. Conclusion : Magnesium supplementation (64 mmol/day) may not be beneficial for the reduction of the incidence of symptomatic cerebral vasospasm in patients with aneurysmal SAH.

Anti-apoptotic and Neuroprotective Effects of Gastrodiae Elata Pharmacupuncture at $GB_{20}$ on Focal Brain Ischemic Injury Induced by Intraluminal Filament Insertion in Rats (풍지(風池)($GB_{20}$)의 천마약침(天麻藥鍼)이 Intraluminal Filament 삽입술에 의하여 유발된 백서(白鼠)의 뇌허혈에 미치는 영향)

  • Na, Geon-Ho;Youn, Dae-Hwan;Na, Chang-Su;Chae, Woo-Suk
    • Journal of Acupuncture Research
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    • v.25 no.1
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    • pp.1-14
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    • 2008
  • Objectives : Delayed neuronal death(DND) of pyramidal neuronsin the CA1 regions of the hippocampus has been extensively studied following global brain ischemia, whereas little is known about DND in this highly vulnerable brain region after focal brain ischemia. The aim of the present study was to investigate the effect of Gastrodiae Elata(GA) pharmacopuncture on hippocampal neuronal apoptosis in rats with focal brain ischemic injury. Materials and methods : The neuroprotective effects of water extracts of GA were investigated in middle cerebral artery occlusion(MCAo) of Sprague-Dawley(SD) rats. Seventy-five healthy SD ratswere randomly divided into five groups following MCAo : control group with focal ischemia, saline injection group, pharmacopuncture group GA-1($0.0007mg/m{\ell}/g$), pharmacopuncture group GA-2($0.00035mg/m{\ell}/g$), pharmacopuncture group GA-3($0.00014mg/m{\ell}/g$). Results : The intensity of mGluR5 increased in the GA-1 group. The intensity of Bax and the Bax/Bcl-2 ratio decreased in the GA-1 group. The intensity of Bcl-2 increased in all the GA groups. The density of neurons stained by Cresyl violet and ChAT increased in the GA-1 group. Conclusions : Our study suggests that GA pharmacopuncture at $GB_{20}$ showed anti-apoptotic and neuroprotective effects on cholinergic neuronsin focal cerebral ischemia caused by stroke in SD rats.

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A Study on Optimal Combustion Conditions with a Design and Manufacture of the Long-Stroke Slow Speed 4 Cycle Diesel Engine (장-행정 저속 4 사이클 디젤기관의 제작 및 최적 연소조건에 관한 연구)

  • 장태익
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.3
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    • pp.551-558
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    • 2004
  • Recently, fuel prices have been continually raised in diesel engine. Such a change in the fuel price influences enormously the development trend of marine diesel engines for slow speed, In other words, the focus was shifted from large diameter and high speed to low fuel consumption. Accordingly, more efforts are being made for engine manufacturing and development to develop highly efficient engines. In this study. a single cylinder 4 stroke cycle DI slow speed diesel engine was designed and manufactured, a 4 stroke cycle was configured and basic performances were evaluated. The results are as follows. The optimal fuel injection timing had the lowest value when specific fuel consumption was in BTDC 8~$10^{\circ}$, a little more delayed compared to high speed diesel engines. Cycle variation of engines showed about 5% difference at full loads. This is a significantly small value compared to the cycle variation in which stable operation is possible, showing the high stability of engine operation is good. The torque and brake thermal efficiency of engine increased with an increase of engine 250-450 rpm. but fuel consumption ratio increased from the 450 rpm zone and thermal efficiency abruptly decreased. Mechanical efficiency was maximally 70% at a 400 rpm that was lower than normal engines according to the increase of mechanical frictional loss for cross head part. The purpose of this study was to get more practical engines by comparing the above results with those of slow speed 2 stroke cycle diesel engines.

Study on the Renal Anemia - Experimental Study in Acute Renal Anemia - (신성빈혈(腎性貧血)에 관(關)한 연구(硏究) - 급성신성빈혈(急性腎性貧血)의 실험적(實驗的) 고찰(考察) -)

  • Yoon, Zo-Eun
    • The Korean Journal of Nuclear Medicine
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    • v.3 no.2
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    • pp.1-16
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    • 1969
  • The double tracer study on erythrokinetics was carried out experimentally with radioactive iron ($^{59}Fe$) and chromium ($^{51}Cr$) in rabbits. The 0.1% canthalidin solution and 1% pot. perchlomate solution was given subcutaneously to 20 rabbits respectively. 3 and 6 days after injection, the blood chemistry, urine examination, ferrokinetics and apparent half survival time of RBC were ($^{51}Cr\;T\frac{1}{2}$)determined. Following were the results: 1) Red blood cell hematocrit and hemoglobin values were moderately reduced and B.U.N. and serum creatinine values were slight]y inercased in the canthalidin group, while B.U.N. and serum creatinine values were within normal limits in the pot. perchlomate group. Reticulocyte values were slight]y increased in the canthalidin group, while was normal range in the pot. perchlomate group. 2) Blood chemistry finding was not significant statistically in both experimental groups, but serum iron value was moderately reduced in both group. 3) Plasma volume was unchanged in both group, but red cell volume and whole blood volume were slightly reduced in both groups. 4) Results of ferrokinetics were as follows: i) The plasma iron disappearance rate was delayed in both groups. Plasma iron turnover rate, red cell iron utilization and red cell iron turnover rate were decreased in both groups, and then red cell iron turnover rate was more decreased than plasma iron turnover rate in both groups. Circulating red cell iron was slight]y increased in canthalidin group and red cell iron concentration was within normal range in both groups. ii) P.I.T.R.-R.C.I.T. value was moderately increased in the canthalidin group and slightly increased in the pot. perchlomate group. Reticulocyte index, red cell iron turnover index, plasma iron turnover index and effective erythropoiesis index were whole]y reduced in both groups. iii) The red cell life span was slightly shortened in the canthalidin group while was within normal range in pot. perchlomate group. The pathologic finding of renal biopsy of the canthalidin group shows a selective damage in glomerulus, while shows almost normal range or slight damage in tubules. And that of the pot. perchlomate group shows a selective damage in tubules with slight damage of glomerulus.

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A COMPUTATIONAL STUDY ABOUT BEHAVIOR OF AN UNDERWATER PROJECTILE USING A HOMOGENEOUS MIXTURE MODEL ON UNSTRUCTURED MESHES (비정렬 격자계에서 균질혼합 모델을 이용한 수중 운동체의 거동에 관한 수치적 연구)

  • Jo, S.M.;Choi, J.H.;Kwon, O.J.
    • Journal of computational fluids engineering
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    • v.21 no.3
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    • pp.15-23
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    • 2016
  • In the present study, two phase flows around a projectile vertically launched from an underwater platform have been numerically investigated by using a three dimensional multi-phase RANS flow solver based on pseudo-compressibility and a homogeneous mixture model on unstructured meshes. The relative motion between the platform and projectile was described by six degrees of freedom equations of motion with Euler angles and a chimera technique. The propulsive power of the projectile was modeled as the fluid force acting on the lower surface of the body by the compressed air emitted from the underwater platform. Various flow conditions were considered to analyze the fluid-dynamics motion parameters of the projectile. The water level of platform and the current speed around the projectile were the main parametric variables. The numerical calculations were conducted up to 0.75sec in physical time scale. The dynamics tendency of the projectile was almost identical with respect to the water level variation due to the constant buoyancy term. The moving speed of the projectile along the vertical axis inside the platform decreased when the current speed increased. This is because the inflow from outside of the platform impeded development of the compressed air emitted from the floor surface of the launch platform. As a result, the fluid force acting on the lower surface of the projectile decreased, and injection time of the projectile from the platform was delayed.