Micro-patterning of single-walled carbon nanotubes and its surface modification with gold nanoparticles for electrochemical paper-based non-enzymatic glucose sensor

Tran, Van-Khue,Ko, Euna,Geng, Yanfang,Kim, Min Ki,Jin, Ga Hyun,Son, Seong Eun,Hur, Won,Seong, Gi Hun Elsevier 2018 Journal of Electroanalytical Chemistry Vol.826 No.-

<P><B>Abstract</B></P> <P>We developed a novel micro-patterning technique for single-walled carbon nanotubes (SWCNTs) on nitrocellulose (NC) membranes and characterized the mechanical and electrical properties of the patterned SWCNTs. The SWCNT patterns were successfully fabricated on wax-printed NC membrane by a vacuum filtration method within 15 min. The well-deposited SWCNT layer on the NC membrane exhibited strong adhesion and high conductivity due to the interconnection of the SWCNT layer in the porous structure of the NC membrane. The distinguishable patterns were resolved down to approximately 100 μm. The patterned SWCNT had an average resistivity of less than 100 Ω/sq and showed excellent mechanical properties in repeated bending tests. The suitability of the patterned SWCNT electrodes for electronic devices was demonstrated successfully via a simple light emitting diode array. Moreover, for the application of the patterned SWCNT to electrochemical paper-based analytical devices (ePADs), the gold nanoparticles (AuNPs) were directly deposited on the SWCNT electrode for non-enzymatic glucose determination. The oxidation peak had a linear response with glucose concentration in the range between 0.5 and 10 mM. The ePADs exhibited a sensitivity of 240 μA/mM·cm<SUP>2</SUP> and a detection limit of 148 μM, which was derived from the electro-catalytic property of AuNPs toward glucose. Based on these results, we believe that the developed SWCNT patterning technique on paper substrates has great potential in ePADs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Micro-patterns of single-walled carbon nanotubes (SWCNTs) were successfully fabricated on wax-printed papers. </LI> <LI> AuNPs were deposited on the SWCNT electrodes for the application to electrochemical paper-based analytical devices. </LI> <LI> The developed devices were applied successfully to non-enzymatic glucose determination. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preliminary Analysis of Brain Footprints in Multiple Sclerosis Females With Detrusor Sphincter Dyssynergia: A Concurrent Urodynamic and Functional Magnetic Resonance Imaging Study

Khue Tran,Logan Hubbard,Christof Karmonik,Timothy B Boone,Rose Khavari 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.S1

Purpose: This study evaluates the grey and white brain matter characteristics in women with multiple sclerosis (MS) and detrusor sphincter dyssynergia (DSD). Grey matter is assessed via the functional connectivity (FC) of brain regions activated during voiding, using functional magnetic resonance imaging (fMRI). Two white matter tracts involved in bladder function, the anterior thalamic radiation (ATR) and superior longitudinal fasciculus (SLF), were evaluated using diffusion tensor imaging. Methods: Twenty-seven women with MS (2 groups: no-DSD [n=23] or DSD [n=4]), and 8 healthy controls (HCs) underwent concurrent urodynamic-fMRI evaluation with 4 cycles of bladder filling and emptying. A FC similarity measure (FC_ sim) was calculated for each subject to express the similarity of individual FC at voiding initiation compared to all FC patterns. ATR and SLF tracts were traced and their fractional anisotropy (FA) and mean diffusivity (MD) were recorded. Results: Mean FC_sim values were significantly different among the 3 groups indicating distinct FC patterns; however, no significant difference was found between DSD and no-DSD groups. DSD group showed trends of lower FA and higher MD— indicating loss of coherence—in all tracts compared to HCs, and in the left and right ATR when compared to MS women with neither DSD nor voiding dysfunction (VD), suggesting more damage in these tracts for MS women with DSD. Conclusions: Women with MS show distinctly different FC patterns compared to HCs. There are trends showing more damage in the ATR in women with MS and DSD compared to those with neither DSD nor VD.

Exposure to Tobacco Advertising and Promotion among School Children Aged 13-15 in Vietnam - an Overview from GYTS 2014

Tran, Khanh Long,Phung, Xuan Son,Kim, Bao Giang,Phan, Thi Hai,Doan, Thi Thu Huyen,Luong, Ngoc Khue,Pham, Thi Quynh Nga,Nguyen, Tuan Lam,Hoang, Van Minh,Le, Thi Thanh Huong Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

Evidence shows that tobacco advertising and promotion activities may increase tobacco consumption and usage, especially in youth. Despite the regulation on prohibiting advertisement of any tobacco product, tobacco advertisement and promotion activities are still common in Vietnam. This article presents current exposure to tobacco advertising and promotion (TAP) among school children aged 13 to 15 years in Vietnam in 2014 and potential influencing factors. Data from the Global Youth Tobacco Survey 2014 in Vietnam covering 3,430 school aged children were used. Both descriptive and analytical statistics were carried out with Stata 13 statistical software. Binary logistic regression was applied to explain the exposure to TAP among youth and examine relationships with individual factors. A significance level of p<0.05 and sampling weights were used in all of the computations. In the past 30 days, 48.6% of the students experienced exposure to at least 1 type of tobacco advertising or promotion. Wearing or otherwise using products related to tobacco was the most exposure TAP type reported by students (22.3%). The internet (22.1), points of sales (19.2) and social events (11.5) were three places that students aged 13-15 frequently were exposed to TAP. Binary logistic results showed that gender (female vs male) (OR = 0.61, 95%CI: 0.52 - 0.71), susceptibility to smoking (OR = 2.12, 95%CI: 1.53 - 2.92), closest friends' smoked (OR = 1.43, 95%CI: 1.2 - 1.7) and parents smoking status (OR = 2.83, 95%CI: 1.6 - 5.01) were significantly associated with TAP exposure among school-aged children. The research findings should contribute to effective implementation of measures for preventing and controlling tobacco use among students aged 13-15 in Viet Nam.

Simultaneous degradation of 2,4,6-trinitrophenyl-N-methylnitramine (Tetryl) and hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) in polluted wastewater using some advanced oxidation processes

Do Ngoc Khue,Tran Dai Lam,Nguyen Van Chat,Vu Quang Bach,Do Binh Minh,Vu Duc Loi,Nguyen Van Anh 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Here we report the study on the utilization of several advanced oxidation processes such as electro-oxidation and Fenton process in simultaneous treatment of two nitramine explosives: 2,4,6-trinitrophenyl-N-metylnitramine (Tetryl) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The preliminary tests indicated that the electrolytic method using a TiO2/IrO2/RuO2-coated electrode could rapidly degrade Tetryl but not RDX. While the addition of certain amount of H2O2 induced an increase of Tetryl degradation yield but had insignificant effect on RDX decomposition, the use of Fenton’s reagent showed an enhanced efficiency in degradation of both nitramines. It can be concluded that among tested processes, Fenton process is the most effective for treatment of nitramine-containing wastewaters.

White Matter Integrity in Men With Benign Prostatic Hyperplasia and Bladder Outlet Obstruction and Its Contribution to Lower Urinary Tract Symptoms

Yongchang Jang,Khue Tran,Logan Hubbard,Darshil Choksi,Ricardo R. Gonzalez,Christof Karmonik,Zhaoyue Shi,Rose Khavari 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.3

Purpose: Lower urinary tract symptoms (LUTS) associated with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) can negatively impact quality of life. We evaluated the structural connectivity of the brain in men with BPH with chronic BOO using diffusion tensor imaging (DTI). Methods: Ambulatory male patients aged ≥45 years with BPH and BOO were recruited. LUTS was defined as an International Prostate Symptom Score (IPSS) ≥12 and a maximum urinary flow rate ≤15 mL/sec. Upon recruitment, uroflowmetry and validated questionnaires regarding bladder status were collected. DTI images from each subject were aligned with the ICBM-DTI-81 atlas, defining 50 white matter tracts (WMTs). The mean values of DTI parameters—fractional anisotropy and mean diffusivity—for each WMT were extracted. These measures were then utilized to compute Pearson correlation coefficients with clinical parameters. Objective clinical parameters included uroflowmetry parameters, postvoid residual (PVR) volume, and bladder capacity. Subjective clinical parameters were assessed using validated questionnaires: the IPSS, Incontinence Symptom Index, and Sexual Health Inventory for Men. Results: The correlation analysis revealed 15 WMTs that showed statistically significant associations (P<0.05) with objective and subjective clinical parameters. Eight tracts were associated with uroflowmetry parameters: maximum flow rate (Qmax), mean flow rate (Qmean), and PVR. Among these tracts, the middle cerebellar peduncles and left medial lemniscus were associated with Qmax; the genu of the corpus callosum, left superior corona radiata, corticospinal tract, right medial lemniscus, posterior corona radiata with Qmean; and the left posterior corona radiata with PVR. Seven tracts also demonstrated significant associations with the IPSS. Conclusions: Our results suggest correlations between the preserved white matter integrity of specific WMTs and the severity of LUTS based on objective and subjective clinical parameters, leading us to believe that a distinct pathology of the central nervous system might exist.

Continuous electrochemical detection of hydrogen peroxide by Au-Ag bimetallic nanoparticles in microfluidic devices

Ko, Euna,Tran, Van-Khue,Geng, Yanfang,Chung, Woo Sung,Park, Chan Ho,Kim, Min Ki,Jin, Ga Hyun,Seong, Gi Hun Elsevier 2017 Journal of electroanalytical chemistry Vol.792 No.-

<P><B>Abstract</B></P> <P>We developed electrochemical microfluidic devices containing Au-Ag bimetallic nanoparticles on single-walled carbon nanotube (SWCNT) electrodes for precise, rapid and non-enzymatic electrochemical detection of hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>). A homogeneous SWCNT layer on a glass substrate was patterned by a standard photolithography method and an O<SUB>2</SUB>-plasma technique. The patterned SWCNT layers were used as working electrode, counter electrode, and reference electrode in a 1mm wide and 23μm deep microchannel. To enhance the electrochemical catalytic properties of the working electrode, Au covered Ag nanoparticles (NPs) were electrochemically deposited on the SWCNT working electrode with current streaming solution into a microfluidic channel. The AgNPs had catalytic activity to improve the reduction of H<SUB>2</SUB>O<SUB>2</SUB> combined with AuNPs, which could support catalytic reaction of AgNPs. The reduction in H<SUB>2</SUB>O<SUB>2</SUB> in fabricated devices was monitored at an optimized condition and was linear with H<SUB>2</SUB>O<SUB>2</SUB> concentration, resulting in a sensitivity of 13.1μA·cm<SUP>−2</SUP>·mM<SUP>−1</SUP>, a correlation coefficient of r<SUP>2</SUP> =0.985, and limit of detection 26.8μM (S/N=3). For the analysis of real samples, diluted antiseptic solutions containing 3wt% H<SUB>2</SUB>O<SUB>2</SUB> were used to determine the concentration of H<SUB>2</SUB>O<SUB>2</SUB> in the pharmaceutical sample. The recovery values ranged from 97% to 107%, and relative standard deviations were below 5%. We expect that the developed microfluidic sensor is a prospective electrochemical platform for accurate, reproducible non-enzymatic detection of H<SUB>2</SUB>O<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electrochemical microfluidic devices containing Au-Ag bimetallic nanoparticles were developed for real-time detection of H<SUB>2</SUB>O<SUB>2</SUB> </LI> <LI> Au-Ag bimetallic nanoparticles showed distinctly larger reduction current comparing to monometallic nanoparticles. </LI> <LI> In the analysis of real samples, antiseptic solutions containing H<SUB>2</SUB>O<SUB>2</SUB> were analyzed successfully in the microfluidic devices. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Measurement of isomeric yield ratios for the 44m,gSc isomeric pairs produced from 45Sc and natTi targets at 50-, 60-, and 70-MeV bremsstrahlung

Do, Nguyen Van,Khue, Pham Duc,Thanh, Kim Tien,Nam, Tran Hoai,Rahman, Md. Shakilur,Kim, Kyung-Sook,Lee, Manwoo,Kim, Guinyun,Lee, Hee-Seock,Cho, Moo-Hyun,Ko, In Soo,Namkung, Won Springer-Verlag 2011 JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY Vol.287 No.3

Oral cavity: An open horizon for nanopharmaceuticals

Nguyen Oanh Oanh Thi,Tran Khue Dan,Ha Nhan Thi,Doan Sang Minh,Dinh Thi Thanh Hai,Tran Tuan Hiep 한국약제학회 2021 Journal of Pharmaceutical Investigation Vol.51 No.4

Background Oral administration is the primary route employed for drug delivery. In addition to the gastrointestinal tract, the oral cavity has been drawing considerable attention owing to its physiological properties and advances in drug carrier development. Notably, nanotechnology has made immense contributions to enhancing drug bioavailability, stability, and efficacy, both in research and clinical settings. Area covered The present review comprises lessons from physiological characteristics to fundamental material science knowledge, summarizing the pros and cons of nanotechnology applications in therapeutic drug delivery. The oral cavity presents inherent challenges, including oral cancer, dental caries, oral infection, or oral inflammation, that necessitate local solutions. Simultaneously, the vascular system under the tongue and in the buccal region offers a portal for systemic drug absorption. Expert opinion Among available delivery systems, nanoparticle-based drug delivery, with the oral cavity as the action or absorption site, can be developed as a principal dosage formulation. Although convenience and fast onset might be advantageous, additional studies are warranted for preclinical characterization, especially in animal models, and for determining manufacturing competence, prior to human trials to meet standards in clinical settings.

Electrochemical Detection of Hydroxylamine <i>via</i> Au-Pt Alloy Nanoparticle-modified Single-walled Carbon Nanotube Electrodes

GENG, Yanfang,KO, Euna,TRAN, Van-Khue,CHUNG, Woo Sung,PARK, Chan Ho,KIM, Min Ki,JIN, Ga Hyun,SEONG, Gi Hun Japan Society for Analytical Chemistry 2017 Analytical sciences Vol.33 No.9

Is the Brainstem Activation Different Between Healthy Young Male and Female Volunteers at Initiation of Voiding? A High Definition 7-Tesla Magnetic Resonance Imaging Study

Bradley Schott,Darshil Choksi,Khue Tran,Christof Karmonik,Betsy Salazar,Timothy Boone,Rose Khavari 대한배뇨장애요실금학회 2023 International Neurourology Journal Vol.27 No.3

Purpose: Assessing brainstem function in humans through typical neuroimaging modalities has been challenging. Our objective was to evaluate brain and brainstem activation patterns during initiation of voiding in healthy males and females utilizing a 7 Tesla magnetic resonance imaging (MRI) scanner and a noninvasive brain-bladder functional MRI (fMRI) protocol. Methods: Twenty healthy adult volunteers (10 males and 10 females) with no history of urinary symptoms were recruited. Each volunteer underwent a clinic uroflow and postvoid residual assessment and was asked to consume water prior to entering the scanner. Anatomical and diffusion tensor images were obtained first, followed by a blood oxygenation level dependent (BOLD) resting-state fMRI (rs-fMRI) during the empty bladder. Subjects indicated when they felt the urge to void, and a full bladder rs-fMRI was obtained. Once completed, the subjects began 5 voiding cycles, where the first 7.5 seconds of each voiding cycle was identified as “initiation of voiding.” BOLD activation maps were generated, and regions of interests with a t-value greater than 2.1 were deemed statistically significant. Results: We present 5 distinct regions within the periaqueductal gray (PAG) and pontine micturition center (PMC) with statistically significant activation associated with an initiation of voiding in both men and women, 3 within the PAG and 2 within the PMC. Several additional areas in the brain also demonstrated activation as well. When comparing males to females, there was an overall lower BOLD activation seen in females throughout all regions, with the exception of the caudate lobe. Conclusions: Our study effectively defines regions within the PAG and PMC involved in initiation of voiding in healthy volunteers. To our knowledge, this is the first study investigating differences between male and female brainstem activation utilizing an ultra-high definition 7T MRI.