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1.
Molecules ; 28(10)2023 May 18.
Article in English | MEDLINE | ID: mdl-37241912

ABSTRACT

Cold atmospheric plasma (CAP) may have applications in treating various types of malignant tumors. This study assessed the anticancer effects of CAP using melanoma and colon cancer cell lines. CAP treatment significantly reduced the in vitro viability of melanoma and colon cancer cell lines and had a negligible effect on the viability of normal human melanocytes. Additionally, CAP and epidermal growth factor receptor (EGFR) inhibitor had an additive anticancer effect in a CAP-resistant melanoma cell line. Reactive oxygen and nitrogen species known to be generated by CAP enhanced the anticancer effects of CAP and EGFR inhibitors. The in vivo anticancer activities of CAP were evaluated by testing its effects against syngeneic tumors induced in mice by melanoma and colon cancer cells. CAP treatment reduced tumor volume and weight in both cancer models, with the extent of tumor reduction dependent on the duration and number of CAP treatments. Histologic examination also revealed the tumoricidal effects of CAP in both tumor models. In conclusion, CAP inhibits the growth of mouse melanoma and colon cancer cell lines in vitro and shows tumoricidal effects against mouse models of melanoma and colon cancer in vivo.


Subject(s)
Colonic Neoplasms , Melanoma , Plasma Gases , Humans , Animals , Mice , Plasma Gases/pharmacology , Plasma Gases/therapeutic use , Cell Line, Tumor , Melanoma/drug therapy , Melanoma/metabolism , Colonic Neoplasms/drug therapy , ErbB Receptors
2.
Microorganisms ; 9(12)2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34946088

ABSTRACT

Outbreaks of 2-methylisoborneol (2-MIB) contamination in drinking water sources cause inconvenient odor issues in the water distribution system. In this study, microscopy-based isolation with physiological and molecular phylogenetic characterization were performed to investigate and characterize the 2-MIB odor producers that caused an odor problem in the freshwater system of the North Han River in the autumn of 2018. A benthic cyanobacterium was isolated from 2-MIB odor-issue freshwater samples and was found to be phylogenetically affiliated with Pseudanabaena yagii (99.66% sequence similarity), which was recorded in South Korea for the first time. The 2-MIB synthesis gene sequences from the odor-issue freshwater samples showed 100% similarity with those in the P. yagii strains. Protein sequences of 2-MIB synthase observed in the genome of the isolated strain showed structural and functional characteristics similar to those observed in other Pseudanabaena species. The 2-MIB production rate increased slowly during mat formation on the vessel wall; however, it rapidly increased after the temperature dropped. The 2-MIB gene was continuously expressed regardless of the temperature changes. These results suggest that the 2-MIB odor issue in the North Han River might be caused by the release of 2-MIB from the mat-forming P. yagii species in a low-temperature freshwater environment.

3.
Microbiol Resour Announc ; 9(47)2020 Nov 19.
Article in English | MEDLINE | ID: mdl-33214301

ABSTRACT

The complete genome and plasmid sequences of Raphidiopsis curvispora strain GIHE-G1, a coiled filamentous heterocyst-forming cyanobacterium isolated from a drinking water reservoir in South Korea, are reported here. The genome information is expected to improve understanding of this species.

4.
Microbiol Resour Announc ; 9(27)2020 Jul 02.
Article in English | MEDLINE | ID: mdl-32616632

ABSTRACT

The draft genome sequence of Pseudanabaena yagii GIHE-NHR1, a filamentous cyanobacterium, is reported here. Comparative genome analysis suggests that this strain can produce an odor-causing compound (2-methylisoborneol) in water. The genome information is expected to improve the understanding of the putative 2-methylisoborneol production by the bacterium.

5.
Microbiol Resour Announc ; 9(6)2020 Feb 06.
Article in English | MEDLINE | ID: mdl-32029564

ABSTRACT

The draft genome sequence of Raphidiopsis (Cylindrospermopsis) raciborskii strain GIHE 2018, a filamentous nitrogen-fixing and potentially harmful cyanobacterium, is reported here. This is the first strain isolated from a shallow freshwater pond in South Korea. This information is expected to improve our understanding of the phylogeography of this species.

6.
J Nanosci Nanotechnol ; 15(8): 5684-90, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26369139

ABSTRACT

Poly(3,4-ethylenedioxythiophene)-(PEDOT)-functionalized reduced graphene oxide (rGO) with MnO2 nanoparticles (MnO2/PEDOT/rGO) was prepared using electrochemical methods. The MnO2/ PEDOT/rGO was obtained through the electrochemical reduction of PEDOT/GO and under electrochemical treatment in KMnO4. The PEDOT/rGO and MnO2/PEDOT/rGO were characterized by several instrumental and electrochemical methods. The electrocatalytic 02 reduction for both electrodes was investigated via cyclic and hydrodynamic voltammetry in 0.1 M KOH aqueous solutions. The kinetic analysis in comparison to PEDOT/rGO a significant enhancement was found for the MnO2/PEDOT/rGO. The proposed main path in the oxygen reduction reaction (ORR) mechanism on the MnO2/PEDOT/rGO was the direct four-electron transfer process with faster transfer kinetic rate. The better ORR kinetics were obtained due to the excellent composite formation and well attachment of MnO2 NPs within oxide form. The PEDOT/rGO was less stable for long term use than MnO2/PEDOT/rGO.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/chemistry , Graphite/chemistry , Manganese Compounds/chemistry , Models, Chemical , Nanocomposites/chemistry , Oxides/chemistry , Oxygen/chemistry , Polymers/chemistry , Catalysis , Computer Simulation , Electrochemical Techniques , Kinetics , Materials Testing , Nanocomposites/ultrastructure , Oxidation-Reduction , Particle Size , Surface Properties
7.
J Nanosci Nanotechnol ; 15(8): 5699-705, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26369141

ABSTRACT

The electrocatalytic activities of metal-decorated graphene oxide (GO) catalysts were investigated. Electrochemically reduced GO-S-(CH2)4-S-Pd [ERGO-S-(CH2)4-S-Pd] and GO-S-(CH2)4-S-PdAg alloy [ERGO-S-(CH2)4-S-PdAg] were obtained through the electrochemical reduction of GO-S-(CH2)4-S-Pd and GO-S-(CH2)4-S-PdAg in a pH 5 PBS solution. It was demonstrated that the application of ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg used in a modified GCE improves the electrocatalytic oxidation of formic acid. The addition of an Ag nanoparticle with a carbon chain-Pd in the electrode provides an electrode with very interesting properties for the electrocatalytic oxidation of formic acid. The ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg were characterized via X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg can be employed for the electrocatalytic oxidation of formic acid. The electrochemical behaviors of this electrode were investigated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS).


Subject(s)
Electrochemical Techniques , Formates/chemistry , Graphite/chemistry , Metal Nanoparticles/chemistry , Palladium/chemistry , Silver/chemistry , Alkalies/chemistry , Alloys/chemistry , Catalysis , Electrodes , Materials Testing , Oxidation-Reduction , Oxides/chemistry , Solutions
8.
Food Chem ; 169: 114-9, 2015 Feb 15.
Article in English | MEDLINE | ID: mdl-25236205

ABSTRACT

Orange II, an azo dye, is sometimes illegally used as a red dye in food products despite its adverse health effects if consumed. Therefore, the determination of low concentrations of Orange II is an important target. An Orange II sensor was prepared using electrochemically reduced graphene oxide grafted with 5-amino-1,3,4-thiadiazole-2-thiol-Pt nanoparticles (denoted as ERGO-ATDT-Pt) onto a glassy carbon electrode (GCE) and investigated for Orange II detection in 0.1M acetate buffer solution (ABS at pH 4.5) with prominent reversible redox peaks. A wide linear range of 1×10(-)(8)-6×10(-)(7)M with a low detection limit of 3.4×10(-)(10)M (s/n=3) was found for Orange II detection. This developed ERGO-ATDT-Pt/GCE sensor showed good selectivity, excellent stability and better response to the real sample analysis with excellent recovery.


Subject(s)
Azo Compounds/analysis , Benzenesulfonates/analysis , Electrochemical Techniques/methods , Graphite/chemistry , Electrochemical Techniques/instrumentation , Electrodes , Limit of Detection , Nanoparticles/chemistry , Oxidation-Reduction
9.
J Nanosci Nanotechnol ; 12(12): 8886-92, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23447933

ABSTRACT

Pd nanoparticle catalysts supported by thiolated graphene oxide (tGO) on a glassy carbon electrode (GCE), and denoted as tGO-Pd/GCE, are used in this study for the electrochemical determination of hydroxylamine and hydrazine. The physicochemical properties of tGO-Pd were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). They showed strong catalytic activity toward the oxidation of hydroxylamine and hydrazine. Cyclic voltammetry (CV) and amperometry were used to characterize the sensors' performances. The detection limits of hydroxylamine and hydrazine by tGO-Pd/GCE were 0.31 and 0.25 microM (s/n = 3), respectively. The sensors' sensitivity, selectivity, and stability were also investigated.


Subject(s)
Electrochemical Techniques , Electrodes , Graphite/chemistry , Hydrazines/chemistry , Hydroxylamine/chemistry , Metal Nanoparticles , Palladium/chemistry , Catalysis , Microscopy, Electron, Transmission , Oxidation-Reduction , Oxides/chemistry , Photoelectron Spectroscopy
10.
AMIA Annu Symp Proc ; 2012: 1139-47, 2012.
Article in English | MEDLINE | ID: mdl-23304390

ABSTRACT

Medical data sensors on patients in hospitals produce an increasingly large volume of increasingly diverse real-time data. Because scheduling the transmission of this data through wireless hospital networks becomes a crucial problem, we propose a Reinforcement Learning-based queue management and scheduling scheme. In this scheme, we use a game-theoretical approach where patients compete for transmission resources by assigning different utility values to data packets. These utility functions are largely based on data criticality and deadline, which together determine the data's scheduling priority. Simulation results demonstrate the high performance of this scheme in comparison to a datatype-based scheme, with the drop rate of critical data as a performance measure. We also show how patients can optimize their policies based on the utility functions of competing patients.


Subject(s)
Computer Communication Networks , Monitoring, Physiologic/instrumentation , Wireless Technology , Algorithms , Game Theory , Hospitals , Humans , Mathematical Concepts
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