Source estimation of anthropogenic aerosols collected by a DRUM sampler during spring of 2002 at Gosan, Korea

Han, J.S.,Moon, K.J.,Ryu, S.Y.,Kim, Y.J.,Perry, Kevin D. Elsevier 2005 Atmospheric environment Vol.39 No.17

<P><B>Abstract</B></P><P>Continuous measurements of trace elements in size-segregated aerosols were performed by X-ray fluorescence analysis in order to assess the transport of natural and anthropogenic aerosol sources to Gosan site in springtime 2002. Various aerosol elemental components (such as Al, Ca, Si, K, Ti, and Mn) had low enrichment factors close to one and exhibited a similar temporal variation in coarse particle range (2.5–12μm) indicating the dominant influence of soil dust. On the other hand, in the fine particle size range (0.09–2.5μm), several anthropogenic elements in ambient particles (such as As, Se, Zn, Pb, and Cu) revealed high enrichment (100<EFs<10,000), and similar temporal variation was observed between these elements in partial size range implying that these elements could be emitted from the same anthropogenic sources.</P><P>Factor analysis was conducted with the size- and time-resolved aerosol composition data in order to identify anthropogenic sources of aerosols during non-Asian dust (NAD) period. As a result, it was found that the coarse particles were mainly influenced by soil, seasalt, coal combustion, and metallurgical emission and fine particles were significantly attributed to several anthropogenic sources, such as oil combustion, nonferrous metal source, and municipal incineration. Especially, submicron particles (0.09–0.56μm) were further impacted by motor vehicles and field burning emissions in addition to those sources.</P>

On pandemics and pivots: a COVID-19 reflection on envisioning the future of medical education

Heeyoung Han,Amy Clithero-Eridon,Manuel Joã,o Costa,Caitriona A. Dennis,J. Kevin Dorsey,Kulsoom Ghias,Alex Hopkins,Kauser Jabeen,Debra Klamen,Sophia Matos,John D. Mellinger,Harm Peters,Suzanne Pitama 한국의학교육학회 2021 Korean journal of medical education Vol.33 No.4

The required adjustments precipitated by the coronavirus disease 2019 crisis have been challenging, but also represent a critical opportunity for the evolution and potential disruptive and constructive change of medical education. Given that the format of medical education is not fixed, but malleable and in fact must be adaptable to societal needs through ongoing reflexivity, we find ourselves in a potentially transformative learning phase for the field. An Association for Medical Education in Europe ASPIRE Academy group of 18 medical educators from seven countries was formed to consider this opportunity, and identified critical questions for collective reflection on current medical education practices and assumptions, with the attendant challenge to envision the future of medical education. This was achieved through online discussion as well as asynchronous collective reflections by group members. Four major themes and related conclusions arose from this conversation: Why we teach: the humanitarian mission of medicine should be reinforced; what we teach: disaster management, social accountability and embracing an environment of complexity and uncertainty should be the core; how we teach: open pathways to lean medical education and learning by developing learners embedded in a community context; and whom we teach: those willing to take professional responsibility. These collective reflections provide neither fully matured digests of the challenges of our field, nor comprehensive solutions; rather they are offered as a starting point for medical schools to consider as we seek to harness the learning opportunities stimulated by the pandemic.

Clinical Factors Associated with the Non-Operative Airway Management of Patients with Robin Sequence

Albino, Frank P.,Wood, Benjamin C.,Han, Kevin D.,Yi, Sojung,Seruya, Mitchel,Rogers, Gary F.,Oh, Albert K. Korean Society of Plastic and Reconstructive Surge 2016 Archives of Plastic Surgery Vol.43 No.6

Background The indications for surgical airway management in patients with Robin sequence (RS) and severe airway obstruction have not been well defined. While certain patients with RS clearly require surgical airway intervention and other patients just as clearly can be managed with conservative measures alone, a significant proportion of patients with RS present with a more confusing and ambiguous clinical course. The purpose of this study was to describe the clinical features and objective findings of patients with RS whose airways were successfully managed without surgical intervention. Methods The authors retrospectively reviewed the medical charts of infants with RS evaluated for potential surgical airway management between 1994 and 2014. Patients who were successfully managed without surgical intervention were included. Patient demographics, nutritional and respiratory status, laboratory values, and polysomnography (PSG) findings were recorded. Results Thirty-two infants met the inclusion criteria. The average hospital stay was 16.8 days (range, 5-70 days). Oxygen desaturation (<70% by pulse oximetry) occurred in the majority of patients and was managed with temporary oxygen supplementation by nasal cannula (59%) or endotracheal intubation (31%). Seventy-five percent of patients required a temporary nasogastric tube for nutritional support, and a gastrostomy tube placed was placed in 9%. All patients continued to gain weight following the implementation of these conservative measures. PSG data (n=26) demonstrated mild to moderate obstruction, a mean apneahypopnea index (AHI) of $19.2{\pm}5.3events/hour$, and an oxygen saturation level <90% during only 4% of the total sleep time. Conclusions Nonsurgical airway management was successful in patients who demonstrated consistent weight gain and mild to moderate obstruction on PSG, with a mean AHI of <20 events/hour.

Clinical Factors Associated with the Non- Operative Airway Management of Patients with Robin Sequence

Frank P. Albino,Benjamin C. Wood,Kevin D. Han,Sojung Yi,Mitchel Seruya,Gary F. Rogers,Albert K. Oh 대한성형외과학회 2016 Archives of Plastic Surgery Vol.43 No.6

Background The indications for surgical airway management in patients with Robin sequence (RS) and severe airway obstruction have not been well defined. While certain patients with RS clearly require surgical airway intervention and other patients just as clearly can be managed with conservative measures alone, a significant proportion of patients with RS present with a more confusing and ambiguous clinical course. The purpose of this study was to describe the clinical features and objective findings of patients with RS whose airways were successfully managed without surgical intervention. Methods The authors retrospectively reviewed the medical charts of infants with RS evaluated for potential surgical airway management between 1994 and 2014. Patients who were successfully managed without surgical intervention were included. Patient demographics, nutritional and respiratory status, laboratory values, and polysomnography (PSG) findings were recorded. Results Thirty-two infants met the inclusion criteria. The average hospital stay was 16.8 days (range, 5–70 days). Oxygen desaturation (<70% by pulse oximetry) occurred in the majority of patients and was managed with temporary oxygen supplementation by nasal cannula (59%) or endotracheal intubation (31%). Seventy-five percent of patients required a temporary nasogastric tube for nutritional support, and a gastrostomy tube placed was placed in 9%. All patients continued to gain weight following the implementation of these conservative measures. PSG data (n=26) demonstrated mild to moderate obstruction, a mean apneahypopnea index (AHI) of 19.2±5.3 events/hour, and an oxygen saturation level <90% during only 4% of the total sleep time. Conclusions Nonsurgical airway management was successful in patients who demonstrated consistent weight gain and mild to moderate obstruction on PSG, with a mean AHI of <20 events/hour.

Fast Cyclic Square-Wave Voltammetry To Enhance Neurotransmitter Selectivity and Sensitivity

Park, Cheonho,Oh, Yoonbae,Shin, Hojin,Kim, Jaekyung,Kang, Yumin,Sim, Jeongeun,Cho, Hyun U.,Lee, Han Kyu,Jung, Sung Jun,Blaha, Charles D.,Bennet, Kevin E.,Heien, Michael L.,Lee, Kendall H.,Kim, In Youn American Chemical Society 2018 ANALYTICAL CHEMISTRY - Vol.90 No.22

<P>Although fast-scan cyclic voltammetry (FSCV) has been widely used for in vivo neurochemical detection, the sensitivity and selectivity of the technique can be further improved. In this study, we develop fast cyclic square-wave voltammetry (FCSWV) as a novel voltammetric technique that combines large-amplitude cyclic square-wave voltammetry (CSWV) with background subtraction. A large-amplitude, square-shaped potential was applied to induce cycling through multiple redox reactions within a square pulse to increase sensitivity and selectivity when combined with a two-dimensional voltammogram. As a result, FCSWV was significantly more sensitive than FSCV (<I>n</I> = 5 electrodes, two-way ANOVA, <I>p</I> = 0.0002). In addition, FCSWV could differentiate dopamine from other catecholamines (e.g., epinephrine and norepinephrine) and serotonin better than conventional FSCV. With the confirmation that FCSWV did not influence local neuronal activity, despite the large amplitude of the square waveform, it could monitor electrically induced phasic changes in dopamine release in rat striatum before and after injecting nomifensine, a dopamine reuptake inhibitor.</P> [FIG OMISSION]</BR>

Tracking tonic dopamine levels <i>in vivo</i> using multiple cyclic square wave voltammetry

Oh, Yoonbae,Heien, Michael L.,Park, Cheonho,Kang, Yu Min,Kim, Jaekyung,Boschen, Suelen Lucio,Shin, Hojin,Cho, Hyun U.,Blaha, Charles D.,Bennet, Kevin E.,Lee, Han Kyu,Jung, Sung Jun,Kim, In Young,Lee, Elsevier 2018 Biosensors & bioelectronics Vol.121 No.-

<P><B>Abstract</B></P> <P>For over two decades, fast-scan cyclic voltammetry (FSCV) has served as a reliable analytical method for monitoring dopamine release in near real-time <I>in vivo</I>. However, contemporary FSCV techniques have been limited to measure only rapid (on the order of seconds, <I>i.e.</I> phasic) changes in dopamine release evoked by either electrical stimulation or elicited by presentation of behaviorally salient stimuli, and not slower changes in the tonic extracellular levels of dopamine (<I>i.e.</I> basal concentrations). This is because FSCV is inherently a differential method that requires subtraction of prestimulation tonic levels of dopamine to measure phasic changes relative to a zeroed baseline. Here, we describe the development and application of a novel voltammetric technique, multiple cyclic square wave voltammetry (M-CSWV), for analytical quantification of tonic dopamine concentrations <I>in vivo</I> with relatively high temporal resolution (10 s). M-CSWV enriches the electrochemical information by generating two dimensional voltammograms which enable high sensitivity (limit of detection, 0.17 nM) and selectivity against ascorbic acid, and 3,4-dihydroxyphenylacetic acid (DOPAC), including changes in pH. Using M-CSWV, a tonic dopamine concentration of 120 ± 18 nM (n = 7 rats, ± SEM) was determined in the striatum of urethane anethetized rats. Pharmacological treatments to elevate dopamine by selectively inhibiting dopamine reuptake and to reduce DOPAC by inhibition of monoamine oxidase supported the selective detection of dopamine <I>in vivo</I>. Overall, M-CSWV offers a novel voltammetric technique to quantify levels and monitor changes in tonic dopamine concentrations in the brain to further our understanding of the role of dopamine in normal behavior and neuropsychiatric disorders.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly sensitive and selective electrochemical method for detecting tonic dopamine level <I>in vivo</I>. </LI> <LI> Enhanced visualization of the data by two-dimensional voltammogram of electrochemical responses. </LI> <LI> High temporal resolution (10 s). </LI> </UL> </P>