Highly Sensitive Hydrazine Chemical Sensor Based on CNT-PdPt Nanocomposites

Bimetallic PdPt nanoparticles were prepared using the chemical reduction method. The PdPt nanoparticles were successfully deposited on thiolated carbon nanotubes (CNTs) to form a CNT-PdPt nanocomposite as an electron mediator for the fabrication of a hydrazine sensor. The PdPt nanoparticles had an average particle size of 2.3 nm and were well dispersed on the surfaces of the CNTs in the prepared CNT-PdPt nanocomposite, as demonstrated using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Based on X-ray photoelectron spectroscopy (XPS) results, the estimated proportions of Pd and Pt in the CNT-PdPt nanocomposite were approximately 3.0% and 3.2%, respectively. A fabricated chemical sensor based on CNT-PdPt was found to exhibit better amperometric activity with respect to the hydrazine oxidation reaction than CNT-Pd, CNT-Pt, and commercial Pd/C and Pt/C catalysts. This sensor exhibited a linear range of 0.55–1,200 μM and a detection limit of 0.28 μM (S/N = 3) with a fast response time (within 5 s). Furthermore, the sensor could be used repeatedly for the consecutive detection of hydrazine with good reusability and storage stability. These properties demonstrate that the CNT-PdPt nanocomposite is a promising electron mediator for the fabrication of amperometric hydrazine sensors

Market Segmentation Based on Attributes for the Purchase of Fresh Ginseng

This study aims to subdivide consumers by attributes determined mainly by consumers of fresh ginseng. It is to compare and analyze the characteristics by cluster, and to deduce the implications on distribution and marketing. For this study, a survey was conducted targeting 250 consumers of fresh ginseng. The factors were deduced through performing the exploratory factor analysis on the results of the survey, and the consumers of fresh ginseng were classified through cluster analysis. As a result of the study, the attributes considered for the purchase of fresh ginseng were condensed to the three factors: physical characteristic factor, safety factor, and cultivation indication information factor. With these as the standard, the consumers of fresh ginseng were subdivided into the three clusters: safety-oriented consumption type, label-centered consumption type, and high involvement consumption type. It was found that there were differences in demographic characteristics and attributes considered for purchase of fresh ginseng by cluster analysis. This study suggests the implications for revitalization of the fresh ginseng industry by subdividing consumers of fresh ginseng and suggesting the characteristics by cluster.This research was financially supported by the Rural Development Administration (RDA) of Korea (Grant No.PJ008729).OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000011251/8SEQ:8PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000011251ADJUST_YN:NEMP_ID:A078501DEPT_CD:520CITE_RATE:0FILENAME:첨부된 내역이 없습니다.DEPT_NM:농경제사회학부EMAIL:[email protected]_YN:NCONFIRM:

Vitrification for cryopreservation of 2D and 3D stem cells culture using high concentration of cryoprotective agents

Abstract Background Vitrification is the most promising technology for successful cryopreservation of living organisms without ice crystal formation. However, high concentrations (up to ~ 6–8 M) of cryoprotective agents (CPAs) used in stem cell induce osmotic and metabolic injuries. Moreover, the application of conventional slow-freezing methods to cultures of 3-D organoids of stem cells in various studies, is limited by their size. Results In this study, we evaluated the effect of high concentrations of CPAs including cytotoxicity and characterized human mesenchymal stem cell (MSC) at single cell level. The cell viability, cellular damage, and apoptotic mechanisms as well as the proliferation capacity and multipotency of cells subjected to vitrification were similar to those in the slow-freezing group. Furthermore, we identified the possibility of vitrification of size-controlled 3-D spheroids for cryopreservation of organoid with high survivability. Conclusions Our results demonstrate successful vitrification of both single cell and spheroid using high concentration of CPAs in vitro without cytotoxicity

Neuroprotective Effects of Cuscutae Semen in a Mouse Model of Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative movement disorder that is characterized by the progressive degeneration of the dopaminergic (DA) pathway. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes damage to the DA neurons, and 1-4-methyl-4-phenylpyridinium (MPP+) causes cell death in differentiated PC12 cells that is similar to the degeneration that occurs in PD. Moreover, MPTP treatment increases the activity of the brain’s immune cells, reactive oxygen species- (ROS-) generating processes, and glutathione peroxidase. We recently reported that Cuscutae Semen (CS), a widely used traditional herbal medicine, increases cell viability in a yeast model of PD. In the present study, we examined the inhibitory effect of CS on the neurotoxicity of MPTP in mice and on the MPP+-induced cell death in differentiated PC12 cells. The MPTP-induced loss of nigral DA neurons was partly inhibited by CS-mediated decreases in ROS generation. The activation of microglia was slightly inhibited by CS, although this effect did not reach statistical significance. Furthermore, CS may reduce the MPP+ toxicity in PC12 cells by suppressing glutathione peroxidase activation. These results suggest that CS may be beneficial for the treatment of neurodegenerative diseases such as PD

Stratifying non-small cell lung cancer patients using an inverse of the treatment decision rules: validation using electronic health records with application to an administrative database

To validate a stratification method using an inverse of treatment decision rules that can classify non-small cell lung cancer (NSCLC) patients in real-world treatment records. (1) To validate the index classifier against the TNM 7th edition, we analyzed electronic health records of NSCLC patients diagnosed from 2011 to 2015 in a tertiary referral hospital in Seoul, Korea. Predictive accuracy, stage-specific sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and c-statistic were measured. (2) To apply the index classifier in an administrative database, we analyzed NSCLC patients in Korean National Health Insurance Database, 2002–2013. Differential survival rates among the classes were examined with the log-rank test, and class-specific survival rates were compared with the reference survival rates. (1) In the validation study (N = 1375), the overall accuracy was 93.8% (95% CI: 92.5–95.0%). Stage-specific c-statistic was the highest for stage I (0.97, 95% CI: 0.96–0.98) and the lowest for stage III (0.82, 95% CI: 0.77–0.87). (2) In the application study (N = 71,593), the index classifier showed a tendency for differentiating survival probabilities among classes. Compared to the reference TNM survival rates, the index classification under-estimated the survival probability for stages IA, IIIB, and IV, and over-estimated it for stages IIA and IIB. The inverse of the treatment decision rules has a potential to supplement a routinely collected database with information encoded in the treatment decision rules to classify NSCLC patients. It requires further validation and replication in multiple clinical settings

Spheroid-Induced Epithelial-Mesenchymal Transition Provokes Global Alterations of Breast Cancer Lipidome: A Multi-Layered Omics Analysis

Metabolic rewiring has been recognized as an important feature to the progression of cancer. However, the essential components and functions of lipid metabolic networks in breast cancer progression are not fully understood. In this study, we investigated the roles of altered lipid metabolism in the malignant phenotype of breast cancer. Using a spheroid-induced epithelial-mesenchymal transition (EMT) model, we conducted multi-layered lipidomic and transcriptomic analysis to comprehensively describe the rewiring of the breast cancer lipidome during the malignant transformation. A tremendous homeostatic disturbance of various complex lipid species including ceramide, sphingomyelin, ether-linked phosphatidylcholines, and ether-linked phosphatidylethanolamine was found in the mesenchymal state of cancer cells. Noticeably, polyunsaturated fatty acids composition in spheroid cells was significantly decreased, accordingly with the gene expression patterns observed in the transcriptomic analysis of associated regulators. For instance, the up-regulation of SCD, ACOX3, and FADS1 and the down-regulation of PTPLB, PECR, and ELOVL2 were found among other lipid metabolic regulators. Significantly, the ratio of C22:6n3 (docosahexaenoic acid, DHA) to C22:5n3 was dramatically reduced in spheroid cells analogously to the down-regulation of ELOVL2. Following mechanistic study confirmed the up-regulation of SCD and down-regulation of PTPLB, PECR, ELOVL2, and ELOVL3 in the spheroid cells. Furthermore, the depletion of ELOVL2 induced metastatic characteristics in breast cancer cells via the SREBPs axis. A subsequent large-scale analysis using 51 breast cancer cell lines demonstrated the reduced expression of ELOVL2 in basal-like phenotypes. Breast cancer patients with low ELOVL2 expression exhibited poor prognoses (HR = 0.76, CI = 0.67–0.86). Collectively, ELOVL2 expression is associated with the malignant phenotypes and appear to be a novel prognostic biomarker in breast cancer. In conclusion, the present study demonstrates that there is a global alteration of the lipid composition during EMT and suggests the down-regulation of ELOVL2 induces lipid metabolism reprogramming in breast cancer and contributes to their malignant phenotypes

Efficacy, pharmacokinetics and safety of subcutaneous versus intravenous CT-P13 in rheumatoid arthritis: a randomized phase I/III trial

Objective. To assess non-inferiority of s.c. to i.v. CT-P13 in RA. Methods. Patients with active RA and inadequate response to MTX participated in this phase I/III double-blind study at 76 sites. Patients received CT-P13 i.v. 3 mg/kg [week (W) 0 and W2] before randomization (1:1) at W6 to CT-P13 s.c. via pre-filled syringe (PFS) 120 mg biweekly until W28, or CT-P13 i.v. 3 mg/kg every 8 weeks until W22. Randomization was stratified by country, W2 serum CRP and W6 body weight. From W30, all patients received CT-P13 s.c. In a usability sub- study, patients received CT-P13 s.c. via auto-injector (W46–54) then PFS (W56–64). The primary endpoint was change (decrease) from baseline in disease activity score in 28 joints (DAS28)-CRP at W22 (non-inferiority margin: -0.6). Results. Of 357 patients enrolled, 343 were randomized to CT-P13 s.c. (n ¼ 167) or CT-P13 i.v. (n ¼ 176) at W6. The least-squares mean change (decrease) from baseline (standard error) in DAS28-CRP at W22 was 2.21 (0.22) for CT-P13 s.c. (n ¼ 162) and 1.94 (0.21) for CT-P13 i.v. [n ¼ 168; difference 0.27 (95% CI: 0.02, 0.52)], establishing non-inferiority. Efficacy findings were similar between arms at W54. Safety was similar between arms throughout: 92 (54.8%; CT-P13 s.c.) and 117 (66.9%; CT-P13 i.v.) patients experienced treatment-emergent adverse events (from W6). There were no treatment-related deaths or new safety findings. Usability was similar for CT-P13 s.c. via auto-injector or PFS. Conclusion. CT-P13 s.c. was non-inferior to CT-P13 i.v. in active RA. The convenience of s.c. administration could benefit patients

Systematic functional analysis of kinases in the fungal pathogen Cryptococcus neoformans

Cryptococcus neoformans is the leading cause of death by fungal meningoencephalitis; however, treatment options remain limited. Here we report the construction of 264 signature-tagged gene-deletion strains for 129 putative kinases, and examine their phenotypic traits under 30 distinct in vitro growth conditions and in two different hosts (insect larvae and mice). Clustering analysis of in vitro phenotypic traits indicates that several of these kinases have roles in known signalling pathways, and identifies hitherto uncharacterized signalling cascades. Virulence assays in the insect and mouse models provide evidence of pathogenicity-related roles for 63 kinases involved in the following biological categories: growth and cell cycle, nutrient metabolism, stress response and adaptation, cell signalling, cell polarity and morphology, vacuole trafficking, transfer RNA (tRNA) modification and other functions. Our study provides insights into the pathobiological signalling circuitry of C. neoformans and identifies potential anticryptococcal or antifungal drug targets.OAIID:RECH_ACHV_DSTSH_NO:T201615370RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A003535CITE_RATE:11.329FILENAME:4. ncomms12766.pdfDEPT_NM:농생명공학부EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/fce63c4a-7de7-4741-996f-d8d24af38905/linkCONFIRM:

Effect of Sb-Doped SnO2 Nanostructures on Electrocatalytic Performance of a Pt Catalyst for Methanol Oxidation Reaction

In this study, antimony-doped tin oxide (ATO) support materials for a Pt anode catalyst in direct methanol fuel cells were prepared and electrochemically evaluated. When the heating temperature was increased from 300 to 400 °C, the ATO samples exhibited a slightly decreased specific surface area and increased electrical conductivity. In particular, the ATO sample heated at 350 °C in an air atmosphere showed improved electrical conductivity (1.3 S cm−1) with an optimum specific surface area of ~34 m2 g−1. The supported Pt catalysts were synthesized using a polyol process with as-prepared and heated ATO samples and Vulcan XC-72R as supports (denoted as Pt/ATO, Pt/ATO-350, and Pt/C, respectively). In the methanol oxidation reaction (MOR), compared to Pt/C and Pt/ATO, Pt/ATO-350 exhibited the best electrocatalytic activity and stability for MOR, which could be attributed to Pt nanoparticles on the relatively stable oxide support with high electrical conductivity and interaction between the Pt catalyst and the heated ATO support