• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제23권1호
• /
• pp.40-47
• /
• 2001

To investigate epidermiologic trend in maxillofacial fractures. We retrospectively studied 934 patients with maxillofacial fractures between $1981{\sim}1987$ and $1995{\sim}1999$. The results were compared in the previous group (Group A, patients treated between $1981{\sim}1987$) with those in the recent group (Group B, $1995{\sim}1999$). Also, we studied 516 patient between $1995{\sim}1999$ for occupation, associated injuries, treatment and complications. The sex ratio of men to women decreased (5.6 : 1 in Group A vs. 3.5 : 1 in Group B), and the largest age group was 20 to 29 years. There was the highest incidence in September and Fall. The most frequent cause of maxillofacial fracture in both Group A and B was traffic accidents. The distribution of fracture site did not change appreciably, but the frequency of midfacial fracture increased. In the recent group, the largest occupational group was salaried men, and the largest associated injuries of maxillofacial fracture was head and neck injury. Open reduction was used in 91% of the cases, and post-operation complications were infection, neurologic problem, malocclusion, and mouth opening limitation etc. Our results suggest that the clinical features of patients with maxillofacial fractures have changed during the past decade.

• Bulletin of the Korean Chemical Society
• /
• 제32권8호
• /
• pp.2771-2775
• /
• 2011

Poly-ethylenedioxypyrrole (PEDOP) coated thiolated multiwall carbon nanotubes palladium nanoparticles (MWCNTs-Pd) modified glassy carbon electrode (GCE) [PEDOP/MWCNTs-Pd/GCE] for the determination of hydroquinone (HQ) and it’s isomer catechol (CA) were synthesized and compared with bare GCE and thiolated multiwall carbon nanotubes (MWCNTs-SH/GCE). The modification could be made by simple processes on a GCE with MWCNTs-Pd covered by PEDOP in a 0.05 M tetrabutylammonium perchlorate (TBAP)/MeCN solution system. A well-defined peak potential evaluation of the oxidation of hydroquinone to quinone at 0.05 V (vs. Ag/AgCl), and electrochemical reduction back to hydroquinone were found by cyclic voltammetry (CV) in phosphate buffered saline (PBS) at pH 7.4. Peak current values increased linearly with increasing hydroquinone contents. The peak separation between the anodic and cathodic peaks at the PEDOP/MWCNTs-Pd/GCE was ${\Delta}Ep$ = 40 mV for HQ and ${\Delta}Ep$ = 70 mV for CA, resulting in a higher electron transfer rate. Moreover, good reproducibility, excellent storage stability, a wide linear range (0.1 ${\mu}M$ - 5 mM for HQ and 0.01 ${\mu}M$ - 6 mM for CA), and low detection limits ($2.9{\times}10^{-8}$ M for HQ and $2.6{\times}10^{-8}$ M for CA; S/N = 3) were determined using differential pulse voltammetry (DPV) and amperometric responses; this makes it a promising candidate as a sensor for determination of HQ and CA.

• 한국임상약학회지
• /
• 제20권3호
• /
• pp.278-287
• /
• 2010

The main objective of this study is to evaluate the cost-effectiveness of tafluprost compared with latanoprost in primry open Angle Glaucoma (POAG) or ocular hypertension OH patients in Korea. A decision analytic model was developed from a societal perspective to estimate clinical outcome, drug cost and glaucoma related cost. The model assumes branch like following: successful treatment, switching to other drug, adding other drug, laser or surgery. Treatment success rate is defined as the percentage of patients with elevated IOP achieving <20% reduction, and discontinuation rate is the percentage of patients who were withdrawn due to severe adverse events. A model that is comprised of 1 month cycle length has 1 year. Treatment success rate and discontinuation rate were obtained from published literatures searched in database. Resource utilizations and costs were calculated with national health insurance data and clinical expert opinions. Sensitivity analyses were performed on crucial parameters. Tafluprost is less costly than latanoprost, $609.0 vs $651.2 expected cost. Thus tafluprost was shown to be dominant compared with latanoprost. The results of sensitivity analysis revealed stable across most of the included parameters. According to this study, tafluprost shows more clinical outcome for 1 year than latanoprost. In addition, first-line treatment of tafluprost is a more cost-minimizing strategy associated with POAG or OH compared with latanoprost.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권11호
• /
• pp.6813-6820
• /
• 2013

The present study was conducted to investigate the prognostic significance of co-expression patterna of HER-2, IL-6, TNF-a and TGF-${\beta}1$ in breast cancer, by correlating the number of markers with positive expression with clinicopathological characteristics indicative of tumor progression and overall survival. One hundred thirty consecutive patients with primary breast cancer were prospectively included and evaluated. Serum concentrations of the above markers were measured by ELISA. Median split was used to subdivide patients with marker positive or negative expression. The presence of ${\geq}3$ positive markers was independently associated with extended lymph node (>3) involvement (aOR, 11.94, p=0.001) and lymphovascular invasion (aOR, 12.04, p=0.018), increasing the prognostic significance of each marker considered separately. Additional prognostic information regarding survival was also provided; as the number of positive markers increased, a gradually reduction of survival time was observed. In addition, patients with 4 positive markers had significantly shorter survival (25 vs 39 months, p=0.006) and a more than 4 fold increased risk of death (aHR, 4.35, p=0.003) compared to patients with 3 positive markers. Our findings suggest that the coexpression pattern of these four markers could be used clinically as a useful marker for tumor extension and outcome of breast cancer.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 추계학술대회 논문집
• /
• pp.184-187
• /
• 2007

Hydrogen could be produced from any substance containing hydrogen atoms, such as water, hydrocarbon (HC) fuels, acids or bases. Hydrocarbon fuels couold be converted to hydrogen-rich gas through reforming process for hydrogen production. Even though fuel cell have high efficiency with pure hydrogen from gas tank, it is more beneficial to generate hydrogen from city gas (mainly methane) in residential application such as domestic or office environments. Thus hydrogen is generated by reforming process using hydrocarbon. Unfortunately, the reforming process for hydrogen production is accompanied with unavoidable impurities. Impurities such as CO, $CO_2$, $H_2S$, $NH_3$, and $CH_4$ in hydrogen could cause negative effects on fuel cell performance. Those effects are kinetic losses due to poisoning of electrode catalysts, ohmic losses due to proton conductivity reduction including membrane and catalyst ionomer layers, and mass transport losses due to degrading catalyst layer structure and hydrophobic property. Hydrogen produced from reformer eventually contains around 73% of $H_2$, 20% or less of $CO_2$, 5.8% of less of $N_2$, or 2% less of $CH_4$, and 10ppm or less of CO. Most impurities are removed using pressure swing adsorption (PSA) process to get high purity hydrogen. However, high purity hydrogen production requires high operation cost of reforming process. The effect of carbon dioxide on fuel cell performance was investigated in this experiment. The performance of PEM fuel cell was investigated using current vs. potential experiment, long run (10 hr) test, and electrochemical impedance measurement when the concentrations of carbon dioxide were 10%, 20% and 30%. Also, the concentration of impurity supplied to the fuel cell was verified by gas chromatography (GC).

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1995년도 춘계학술대회논문집; 전남대학교, 19 May 1995
• /
• pp.196-201
• /
• 1995

The broadband and discrete sources of sound in small cooling fans of propeller type and centrifugal type were investigated to understand the turbulent vortex structures from many bladed fans using ANSI test plenum for small air-moving devices (AMDs). The noise measurement method uses the plenum as a test apparatus to determine the acoustic source spectral density function at each operating conditions similar to real engineering applications based on acoustic similarity laws. The characteristics of fans including the head rise vs. volumetric flow rate performance were measured using a performance test facility. The sound power spectrum is decomposed into two non-dimensional functions: an acoustic source spectral distribution function F(St,.phi.) and an acoustic system response function G(He,.phi.) where St, He, and .phi. are the Strouhal number, the Helmholtz number, and the volumetric flow rate coefficient, respectively. The autospectra of radiated noise measurements for the fan operating at several volumetric flow rates,.phi., are analyzed using acoustical similarity. The rotating stall in the small propeller fan with a bell-mouth guided is mainly due to a leading edge separation. It creates a blockage in the passage and the reduction in the flow rate. The sound power levels with respect to the rotational speeds were measured to reveal the mechanisms of stall and/or surge for different loading conditions and geometries, for example, fans installed with a impinging plate. Lee and Meecham (1993) studied the effect of the large-scale motions like impinging normally on a flat plate using Large-Eddy Simulation(LES) and Lighthill's analogy.[ASME Winter Annual Meeting 1993, 93-WA/NCA-22]. The dipole and quadrupole sources in the fans tested are shown closely related to the vortex structures involved using cross-correlations of the hot-wire and microphone signals.

• Advances in pediatric surgery
• /
• 제17권1호
• /
• pp.23-34
• /
• 2011

We analyzed the clinical characteristics and outcome of ileocecal and small bowel intussusceptions (ICI and SBI) in the pediatric patients. From August 2003 to July 2010, 144 children with intussusception were included in this study. We retrospectively reviewed the clinical records and Imaging study findings. A total of 86 children with ICI and 58 children with SBI were diagnosed. Children with SBI were older than ICI ($36.6{\pm}24.6$ months vs. $24.2{\pm}21.6$ months, p=0.002). Typical symptoms such as irritability, abdominal mass, bloody stool were more frequent in ICI than SBI (p<0.05) patients. In the ICI group, intussusceptums were reduced with air reduction (84.5%), surgery (17.4%), and spontaneity (1.2%). All patients in the SBI group were reduced spontaneously. SBI occurred in older age and was reduced spontaneously more frequently than ICI. Conservative management with close observation with follow-up by ultrasonography is recommended for SBI.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권1호
• /
• pp.131-137
• /
• 2008

The objective of the present study was to compare the chemical and sensory properties of regular cream cheese (control) and cholesterol-reduced cream cheese manufactured using crosslinked ${\beta}$-cyclodextrin (${\beta}$-CD) or powdered ${\beta}$-CD. Crosslinked ${\beta}$-CD was made using adipic acid. The composition of cream cheese treated by the crosslinked ${\beta}$-CD was similar to the regular cream cheese. Approximately 91% of cholesterol-reduction was observed in the cheeses that were treated using ${\beta}$-CD, which was not significantly different between powdered vs. crosslinked ${\beta}$-CD treatments. Total amount of short-chain free fatty acids was significantly lower in both ${\beta}$-CD-treated cheeses than in the control cheese throughout the storage. The cheeses made by ${\beta}$-CD-treated cream produced much lower amounts of individual free amino acids than the control in all periods. Most rheological characteristics, except cohesiveness, decreased dramatically in the control compared with the cholesterol-reduced cream cheeses. In sensory attributes, both wateryness and spreadability in ${\beta}$-CD-treated cheeses were significantly higher than in the control during 8 wk storage. Sensory scores for sourness increased significantly in the control from 4 to 8 wk storage, however, those in the cream cheese made by crosslinked-${\beta}$-CD treated cream increased slowly during 8 wk storage, which was shown in the control during a 4 wk period. Therefore, the present study showed the possibility of cholesterol-reduced cream cheese manufacture.

• 유기물자원화
• /
• 제27권4호
• /
• pp.43-49
• /
• 2019

본 연구는 알칼리·초음파 전처리를 통한 하수슬러지의 가용화 정도를 확인하기 위해 슬러지 가용화율과 VSS 감량화율을 측정하였다. 또한 슬러지 가용화와 EPS간의 관계를 확인하기 위해 LB-EPS(Loosely-Bound EPS), TB-EPS(Tightly-Bound EPS)를 측정하였다. 실험 결과, TS 1.0%, pH 12 조건에서 슬러지 가용화율은 27.7% 증가하였고, LB-EPS as Carbohydrate와 Protein은 각각 14.6, 13.3 mg/L/g TS가 증가하여 가용화에 따른 유기물의 변화와 유사한 경향을 나타내었다. 또한 VSS는 26.7% 감량되었고, TB-EPS as Carbohydrate와 Protein은 각각 15.7, 21.9 mg/L/g TS 용출되어 가용화에 따른 고형물의 변화 역시 유사한 경향을 나타내었다.

• 한국융합학회논문지
• /
• 제4권1호
• /
• pp.21-26
• /
• 2013

본 연구의 목적은 국내에서 아직 연구가 미진한 와해성 기술에 대한 이해를 돕기 위해 컴퓨터 저장장치 산업을 대상으로 사례를 선정하고 실증분석 했다. 분석결과, 와해성 기술을 처음 제시했던 Christensen(1992)이 제시한 와해성 기술의 조건에 기존 저장장치인 HDD를 위협하고 있는 SSD가 모두 해당되는 것으로 나타났다. SSD는 HDD보다 기술적으로 우월할 뿐만 아니라 소형화, 경량화, 안정성으로 인해 다른 제품군에 응용이 가능하여 대량 생산이 가능한 것으로 나타났다. 이런 응용분야의 다양성은 대량생산을 가능하게하고 이로 인해 단위당 제품가격이 지속적으로 하락할 수 있는 가능성이 존재하여 추구 지속적인 기술의 확산이 예상된다. 본 연구의 결과는 와해성 기술에 대한 이해를 돕기 위한 실증사례를 제시함으로써 학계뿐만 아니라 실무진에게도 공헌하는바가 크다고 판단된다.