• 폴리머
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• 제32권5호
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• pp.403-408
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• 2008

케라틴은 울, 머리카락, 손톱 등을 형성하는 섬유단백질의 주요성분으로 유용한 생체재료이다. 골수간염 줄기세포를 이용한 조직공학 적용을 위해 Poly(4-lactide-co-glycolide) (PLGA)에 함량별로 케라틴을 함유한 지지체를 용매 캐스팅/염 추출법을 이용하여 제조하였다. 제조된 지지체의 표면과 단면의 형태를 전자현미경(SEM)으로 관찰하고 특성분석을 위해 다공도, 표면 적심성, 물 흡수성, 그리고 열적성질을 분석하였다. 이 후 쥐에서 분리한 골수간엽줄기세포를 지지체에 파종하여 세포의 증식율을 (4,5-dimethylthiazol-2-yl)-2.5-diphenyl-tetrazolium bromide(MTT) 분석방법을 이용하여 측정하였다. 천연/합성 하이브리드 담체인 케라틴/PLGA 지지체는 PLGA 단독으로 제조된 지지체와 비교 시 골수간엽줄기세포의 생장에 유익한 환경을 제공함을 확인하였다.

• Archives of Pharmacal Research
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• 제20권6호
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• pp.555-559
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• 1997

The three different batches of an oral sustained release melatonin (MT) delivery system were prepared by aqueous-based fluid-bed coating of the sugar spheres for the evaluation of in vitro release characteristics and plasma concentration profiles in human subjects. The MT contents in 20% coated sugar spheres of three batches (B1, B2 and B3) were $3.3{\pm}0.08$, $2.4{\pm}0.1$ and $2.5{\pm}0.13$ mg per gram of coated sugar spheres, respectively. The release profiles of three different batches had a very similar fashion. However, the release profiles of three different batches had a very similar fashion. However, the release half-lives $(T_{50%})$ of MT from B1, B2 and B3 was $3.70{\pm}0.2$, $5.2{\pm}0.2$ and $4.9{\pm}0.07h$, respectively. Plasma concentration profiles of sustained release 0.2mg melatonin-loaded sugar spheres containing 10% immediate release melatonin in gelatin capsules (B1 and B2) were then evaluated in human subjects. The in vivo plasma concentration profies of the two batches (B1 and B2) were very similar each other and located between the physiological endogenous ranges. The time to reach the peak concentration $(T_max)$ was more advanced in case of B1 when compared to B2. However, there was no statistically significant difference in the maximum concentration $(C_max)$ and the area under the curve (AUC) between B1 and B2. The AUC of melatonin-loaded sugar spheres containing 10% and 20% immediate release MT in human subjects had a good linearity between dose and AUC, regardless of the fraction of immediate release MT, indicating the first order elimination process of MT within these doses. The current oral sustained release MT delivery system may be utilized to treat circadian rhythm disorders if it is proven to be more clinically useful when compared to immediate release MT.

• 한국토양비료학회지
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• 제8권4호
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• pp.171-176
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• 1975

금해특이산성(金海特異酸性) 토양(土壤)에 퇴비(堆肥) 및 볏짚을 시용(施用)하고 요소(尿素)와 석회(石灰)를 첨가(添加)했을 때 시용(施用)된 유기물(有機物)의 분해율(分解率)을 호기(好氣) 또는 혐기적조건하(嫌氣的條伴下)에서 조사(調査)했던바 다음과 같은 결과(結果)를 얻었다. 1. 혐기적조건하(嫌氣的條件下)에서 퇴비단용(堆肥單用)의 분해(分解)는 볏짚+요소(尿素), 볏짚+석회(石灰), 볏짚 단용(單用) 및 퇴비(堆肥)+석회(石灰) 보다 약(約)2배(培) 이상(以上)높은 분해경향(分解傾向)을 보였다. 2. 퇴비(堆肥)에 석회첨가시(石灰添加時) 혐기적조건하(嫌氣的條件下)에서는 퇴비(堆肥)의 분해(分解)를 저해(阻害)하는 경향(傾向)이나 호기적조건하(好氣的條件下)에서는 분해(分解)를 촉진(促進)하였다. 3. 호기적조건하(好氣的條件下)에서 볏짚에 석회(石灰)나 요소(尿素)의 첨가(添加)는 모두 볏짚의 분해(分解)를 현저(顯著)히 증가(增加)시켰으며 특(特)히 요소처리(尿素處理)가 석회처리(石灰處理) 보다 높은 분해율(分解率)을 보였다. 4. 호기적조건하(好氣的條件下)에서 시용유기물중(施用有機物中)에 들어 있는 총탄소함량중(總炭素合量中) 볏짚의 분해(分解)에 의(依)해 생성(生成)된 탄소량(炭素量)은 10.8%로 퇴비(堆肥)의 23.1%에 비(比)해 약(約) 1/2에 불과하였다. 5. 특이산성토양(特異酸性土壤)에 있어서 질소(窒素)와 석회(石灰)의 시용(施用)으로 인(因)한 유기물(有機物)의 분해(分解)에 미치는 상호작용(相互作用)에 관(關)하여는 더욱 연구(硏究)해 볼 필요(必要)가 있다.

• 대한약침학회지
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• 제22권3호
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• pp.166-170
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• 2019

Objectives: Attentional and memory functions are important aspects of neural plasticity that, theoretically, should be amenable to pharmacopuncture treatments. A previous study from our laboratory suggested that quantitative electroencephalographic (qEEG) measurements of theta/beta ratio (TBR), an index of attentional control, may be indicative of academic performance in a first-semester medical school course. The present study expands our prior report by extracting and analyzing data on frontal theta and beta asymmetries. We test the hypothesis that the amount of frontal theta and beta asymmetries (fTA, fBA), are correlated with TBR and academic performance, thereby providing novel targets for pharmacopuncture treatments to improve cognitive performance. Methods: Ten healthy male volunteers were subjected to 5-10 min of qEEG measurements under eyes-closed conditions. The qEEG measurements were performed 3 days before each of first two block examinations in anatomy-physiology, separated by five weeks. Amplitudes of the theta and beta waveforms, expressed in ${\mu}V$, were used to compute TBR, fTA and fBA. Significance of changes in theta and beta EEG wave amplitude was assessed by ANOVA with post-hoc t-testing. Correlations between TBR, fTA, fBA and the raw examination scores were evaluated by Pearson's product-moment coefficients and linear regression analysis. Results: fTA and fBA were found to be negatively correlated with TBR (P<0.03, P<0.05, respectively) and were positively correlated with the second examination score (P<0.03, P=0.1, respectively). Conclusion: Smaller fTA and fBA were associated with lower academic performance in the second of two first-semester medical school anatomy-physiology block examination. Future studies should determine whether these qEEG metrics are useful for monitoring changes associated with the brain's cognitive adaptations to academic challenges, for predicting academic performance and for targeting phamacopuncture treatments to improve cognitive performance.

• Animal Bioscience
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• 제34권11호
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• pp.1811-1821
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• 2021

Objective: A trial was conducted to investigate the effects of supplemental levels of Mn provided by organic and inorganic trace mineral supplements on growth, tissue mineralization, mineral balance, and antioxidant status of growing broiler chicks. Methods: A total of 500 male chicks (8-d-old) were used in 10-day feeding trial, with 10 treatments and 10 replicates of 5 chicks per treatment. A 2×5 factorial design was used where supplemental Mn levels (0, 25, 50, 75, and 100 mg Mn/kg diet) were provided as MnSO₄·H₂O or MnPro. When Mn was supplied as MnPro, supplements of zinc, copper, iron, and selenium were supplied as organic minerals, whereas in MnSO₄·H₂O supplemented diets, inorganic salts were used as sources of other trace minerals. Performance data were fitted to a linearbroken line regression model to estimate the optimal supplemental Mn levels. Results: Manganese supplementation improved body weight, average daily gain (ADG) and feed conversion ratio (FCR) compared with chicks fed diets not supplemented with Mn. Manganese in liver, breast muscle, and tibia were greatest at 50, 75, and 100 mg supplemental Mn/kg diet, respectively. Higher activities of glutathione peroxidase and superoxide dismutase (total-SOD) were found in both liver and breast muscle of chicks fed diets supplemented with inorganic minerals. In chicks fed MnSO₄·H₂O, ADG, FCR, Mn balance, and concentration in liver were optimized at 59.8, 74.3, 20.6, and 43.1 mg supplemental Mn/kg diet, respectively. In MnPro fed chicks, ADG, FCR, Mn balance, and concentration in liver and breast were optimized at 20.6, 38.0, 16.6, 33.5, and 62.3 mg supplemental Mn/kg, respectively. Conclusion: Lower levels of organic Mn were required by growing chicks for performance optimization compared to inorganic Mn. Based on the FCR, the ideal supplemental levels of organic and inorganic Mn in chick feeds were 38.0 and 74.3 mg Mn/kg diet, respectively.

• Safety and Health at Work
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• 제13권3호
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• pp.263-268
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• 2022

Health care workers (HCWs) are more than ten times more likely to be infected with coronavirus infectious disease 2019 (COVID-19) than the general population, thus demonstrating the burden of COVID-19 among HCWs. Factors that expose HCWs to a differentially high-risk of COVID-19 acquisition are important to elucidate, enable appropriate public health interventions to mitigate against high risk and reduce adverse outcomes from the infection. We conducted a systematic review and meta-analysis to summarize and critically analyze the existing evidence on SARS-CoV-2 risk factors among HCWs. With no geographical limitation, we included studies, in any country, that reported (i) the PCR laboratory diagnosis of COVID-19 as an independent variable (ii) one or more COVID-19 risk factors among HCWs with risk estimates (relative risk, odds ratio, or hazard ratio) (iii) original, quantitative study design, and published in English or Mandarian. Our initial search resulted in 470 articles overall, however, only 10 studies met the inclusion criteria for this review. Out of the 10 studies included in the review, inadequate/lack of protective personal equipment, performing tracheal intubation, and gender were the most common risk factors of COVID-19. Based on the random effects adjusted pooled relative risk, HCWs who reported the use of protective personal equipment were 29% (95% CI: 16% to 41%) less likely to test positive for COVID-19. The study also revealed that HCWs who performed tracheal intubations were 34% (95% CI: 14% to 57%) more likely to test positive for COVID-19. Interestingly, this study showed that female HCWs are at 11% higher risk (RR 1.11 95% CI 1.01-1.21) of COVID-19 than their male counterparts. This article presents initial findings from a living systematic review and meta-analysis, therefore, did not yield many studies; however, it revealed a significant insight into better understanding COVID-19 risk factors among HCWs; insights important for devising preventive strategies that protect them from this infection.

• 중소기업연구
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• 제42권2호
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• pp.117-137
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• 2020

본 논문은 현재 중소기업을 대상으로 추진 중인 스마트공장 보급·확산사업의 현황을 진단하고, 중소기업 관점에서 중소기업 제조 혁신을 위한 발전 방향을 모색한다. 본 논문의 주요 결론은 다음과 같다. 첫째, 스마트공장 보급·확산사업은 추가적인 시장 창출과 공급망 개선을 전제로 추진되어야 한다. 둘째, 스마트공장 보급·확산사업은 "생산·공정"의 효율화를 넘어 "R&D"나 "판로"와 연계되는 새로운 사업을 창출하는 것을 지향해야 한다. 셋째, 공정기술이 기업 경쟁력으로 직결될 수 있는 분야를 중심으로 스마트공장 구축을 우선 지원할 필요가 있다. 본 논문에서는 미국의 제조혁신연구소(Manufacturing Innovation Institute)의 사례를 참조하고, Pisano and Shih (2012)의 제품·프로세스 혁신 프레임워크를 사용하여 다음 네 가지 정책과제를 제시한다. 첫째, 스마트공장 추진 전략을 양적 확산 위주에서 질적 고도화로 전환한다. 둘째, 각 업종별로 중견·중소기업 중심의 공통기술개발과 표준화된 데이터 교환 및 업무교류 시스템 구축, 납품업체 중심의 조달시스템 운영 등을 추진한다. 셋째, 신기술·신사업 모델의 구현을 위해 기존 중소기업과 창업·벤처기업과의 제휴 및 협업, M&A를 장려한다. 넷째, 스마트공장의 세부 항목을 지수화하여 스마트공장 보급 전략의 적절성과 정책 지원의 문제점을 신속히 파악하고 보완한다.

• 동굴
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• 제4호
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• pp.41-50
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• 1996

The coastal plains of the Puna and Ka' u Districts of the island of Hawaii are a contradiction to the popular view that the island of Hawaii is a tropical rain forest or a vegetated landscape with abundant water sour This section of the island lies in the rain shadow of Mauna Loa a Kilauea Volcanoes and receives less than 30 inches of annual precipita When rain does come. it is in the form of sudden down pours. givi residents of the area little time to collect and conserve water. Due to porous nature of the rock. there is no standing surface water. In spite of these harsh climatic conditions. archeological evidence indic that an extensive agriculture complex existed not only along the coast. into the most remote parts of what is called the Ka'u Desert. Pass through these agricultural areas are historic and pre - historic t systems. These trail systems apparently played a significant suppor role for exchange between the ahupua's (classic land divisions of Haw and the geopolitical districts. The question arises as to how could vast agricultural complexes a heavy foot travel over miles of arid land exist without dependable wa sources\ulcorner While planting - pits and mounds were designed to make most efficient use of available water and conserve moisture(Carter 19 9). people involved in planting also needed potable water for surv Most publications and research papers dealing with the early population this area make only oblique reference to springs and wells which t populations depended upon. The Federal Cave Resource Protection Act(1988) has served as imprtus for the National Park Service to look closer at the lava tu caves and fault cracks within Hawaii Volcanoes National Park. P visitors to these underground areas found large volumes of standing wa in fault cracks. and abundant drip areas with the lava tubes. Re observes noted that in most cases. where the cracks and caves we located in the arid sections of the park. there has been extens modifiacation or utilization of these water sources by the early Hawaii and others. The variety of western containers used for collection indica that these water sources were used during historic times. William E described similar water sources in his narrative of his trip around island in 1823(Eills 1979), This report is directed at documenting recent observations and a stimulating further research into early Hawaiian water collection syst It also explores the implications that power and political influence of e chiefs in the arid portions of Hawaii could have been linked to the con of the water resources.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.227-239
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• 2023

Major depressive disorder is a leading cause of disability in more than 280 million people worldwide. Monoamine-based antidepressants are currently used to treat depression, but delays in treatment effects and lack of responses are major reasons for the need to develop faster and more efficient antidepressants. Studies show that ketamine (KET), a PCP analog, produces antidepressant effects within a few hours of administration that lasts up to a week. However, the use of KET has raised concerns about side effects, as well as the risk of abuse. 4 -F-PCP analog is a novel PCP analog that is also an NMDA receptor antagonist, structurally similar to KET, and might potentially elicit similar antidepressant effects, however, there has been no study on this subject yet. Herein, we investigate whether 4-F-PCP displays antidepressant effects and explored their potential therapeutic mechanisms. 4-F-PCP at 3 and 10 mg/kg doses showed antidepressant-like effects and repeated treatments maintained its effects. Furthermore, treatment with 4-F-PCP rescued the decreased expression of proteins most likely involved in depression and synaptic plasticity. Changes in the excitatory amino acid transporters (EAAT2, EAAT3, EAAT4) were also seen following drug treatment. Lastly, we assessed the possible side effects of 4-F-PCP after long-term treatment (up to 21 days). Results show that 4-F-PCP at 3 mg/kg dose did not alter the cognitive function of mice. Overall, current findings provide significant implications for future research not only with PCP analogs but also on the next generation of different types of antidepressants.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.32-32
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• 2023

Incidences of urban flood and extreme heat waves (due to the urban heat island effect) are expected to increase in New Zealand under future climate change (IPCC 2022; MfE 2020). Increasingly, the mitigation of such events will depend on the resilience of a range Nature-Based Solutions (NBS) used in Sustainable Urban Drainage Schemes (SUDS), or Water Sensitive Urban Design (WSUD) (Jamei and Tapper 2019; Johnson et al 2021). Understanding the impact of changing precipitation and temperature regimes due climate change is therefore critical to the long-term resilience of such urban infrastructure and design. Cuthbert et al (2022) have assessed the trade-offs between the water retention and cooling benefits of different urban greening methods (such as WSUD) relative to global location and climate. Using the Budyko water-energy balance framework (Budyko 1974), they demonstrated that the potential for water infiltration and storage (thus flood mitigation) was greater where potential evaporation is high relative to precipitation. Similarly, they found that the potential for mitigation of drought conditions was greater in cooler environments. Subsequently, Jaramillo et al. (2022) have illustrated the locations worldwide that will deviate from their current Budyko curve characteristic under climate change scenarios, as the relationship between actual evapotranspiration (AET) and potential evapotranspiration (PET) changes relative to precipitation. Using the above approach we assess the impact of future climate change on the urban water-energy balance in three contrasting New Zealand cities (Auckland, Wellington, Christchurch and Invercargill). The variation in Budyko curve characteristics is then used to describe expected changes in water storage and cooling potential in each urban area as a result of climate change. The implications of the results are then considered with respect to existing WSUD guidelines according to both the current and future climate in each location. It was concluded that calculation of Budyko curve deviation due to climate change could be calculated for any location and land-use type combination in New Zealand and could therefore be used to advance the general understanding of climate change impacts. Moreover, the approach could be used to better define the concept of urban infrastructure resilience and contribute to a better understanding of Budyko curve dynamics under climate change (questions raised by Berghuijs et al 2020)). Whilst this knowledge will assist in implementation of national climate change adaptation (MfE, 2022; UNEP, 2022) and improve climate resilience in urban areas in New Zealand, the approach could be repeated for any global location for which present and future mean precipitation and temperature conditions are known.