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1.
ACS Nano ; 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38335539

ABSTRACT

Exciton complexes in two-dimensional semiconductors, encompassing bright and dark excitons, biexcitons, and defect-bound excitons, have shown significant potential across a wide range of research areas. These applications range from exploring quantum many-body phenomena to developing nonclassical light sources and quantum transport devices. To fully leverage their dynamic and interactive properties and extend the capabilities of excitonic devices, realizing systematic engineering and mixing of the exciton complexes are crucial. Unlike conventional material methods, which often lead to undesired changes in the electronic band structure and binding energy, optical methods provide a means to manipulate the radiative decay dynamics of individual exciton complexes in a purely environmental manner. Here, we employ a specialized photonic platform, analogous to an artist's palette, to arrange and mix exciton complexes on an identical two-dimensional transition metal dichalcogenide medium. Essentially, a gradient thickness mirror (GTM) continuously tunes the local distribution of optical vacuum field interference. The GTM platform enables us to create and examine five distinct compositions of the exciton complexes of the WSe2 monolayer and their contributions to the photoluminescence spectrum. Moreover, the exciton complex palette facilitates the observation of dark and defect-bound excitons, even at high temperatures of 70 K, and its performance can be further managed by simple postprocessing manipulations.

2.
Food Sci Biotechnol ; 33(4): 805-815, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38371692

ABSTRACT

Panax ginseng powder adulterated with other root plants (arrowroot, bellflower, and lance asiabell) was discriminated using Fourier transform infrared (FT-IR) spectroscopy, combined with multivariate analysis. Principal component analysis visually diagnosed the adulteration by showing two distinct clusters based on presence of adulteration. Wavenumber regions (1000 cm-1 and 3300 cm-1) selected from the loading plot associated with the vibration of OH and CH bond in ginsenoside and aromatic compounds. A quantitative model for the content of ginsenosides and specific aromatic compounds as indicators of pure ginseng powder, was developed based on partial least square regression analysis. The performance of the prediction model preprocessed with the Savizky-Golay 1st derivative was improved to R2 of 0.9650, 0.9635, and 0.9591 for Rb1, Rc, and ß-Panasinsene, respectively. Therefore, FT-IR technology makes it possible to rapidly authenticate pure ginseng product based on the ginsenoside contents and aroma compound.

3.
Nano Lett ; 23(6): 2158-2165, 2023 Mar 22.
Article in English | MEDLINE | ID: mdl-36854053

ABSTRACT

Embodying bosonic and interactive characteristics in two-dimensional space, excitons in transition metal dichalcogenides (TMDCs) have garnered considerable attention. The utilization of the strong-correlation effects, long-range transport, and valley-dependent properties requires customizing exciton decay dynamics. Vacuum-field manipulation allows radiative decay engineering without disturbing intrinsic material properties. However, conventional flat mirrors cannot customize the radiative decay landscape in TMDC's plane or support vacuum-field interference with desired spectrum and polarization properties. Here, we present a meta-mirror platform resolving the issues with more optical degrees of freedom. For neutral excitons of the monolayer MoSe2, the optical layout formed by meta-mirrors manipulated the radiative decay rate in space by 2 orders of magnitude and revealed the statistical correlation between emission intensity and spectral line width. Moreover, the anisotropic meta-mirror demonstrated polarization-dependent radiative decay control. Our platform would be promising to tailor two-dimensional distributions of lifetime, density, diffusion, and polarization of TMDC excitons in advanced opto-excitonic applications.

4.
Meat Sci ; 197: 109065, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36481517

ABSTRACT

This study investigated the antimicrobial and antibiofilm efficacy of separate and combined treatments of Lactobacillus curvatus B67-produced postbiotic and the polyphenolic flavanol quercetin against Listeria monocytogenes and Salmonella enterica ser. Typhimurium. The antimicrobial potentiality of the postbiotic was chiefly associated with organic acids (e.g., lactic and acetic acids). At sub-minimum inhibitory concentration (1/2 MIC), the postbiotic and quercetin effectively reduced the pathogenic biofilm cells on processed pork sausage and meat-processing surfaces (e.g., stainless-steel and rubber). Moreover, the postbiotic exhibited strong residual antimicrobial efficacy over diverse pH and temperature ranges. In addition, the combination of postbiotic with quercetin increased the leakage of pathogenic intracellular metabolites (e.g., nucleic acids and protein) and inhibited pathogenic biofilm formation on both biotic and abiotic surfaces. Therefore, this study confirmed that lactic acid bacteria-derived postbiotic and plant-derived quercetin could be used as potential alternative bioprotective agents in the meat processing industry.


Subject(s)
Listeria monocytogenes , Salmonella enterica , Lactobacillus , Quercetin/pharmacology , Food Preservation , Meat , Food Microbiology
5.
Brain Tumor Res Treat ; 9(2): 81-86, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34725989

ABSTRACT

Pulmonary blastoma is a rare type of primary lung cancer that accounts for only 0.25%-0.5% of all lung malignancies. Pulmonary blastoma consists of three subgroups: classic biphasic pulmonary blastoma (CBPB), pleuropulmonary blastoma, and well-differentiated fetal adenocarcinoma. Due to the rarity of the tumor, metastatic brain tumor from CBPB is extremely rare, and only 13 cases, including our case, have been reported. A 60-year-old woman who underwent left upper lobectomy of the lung because of pathologically diagnosed as CBPB 5 months ago, suddenly lost consciousness and presented with stupor mental status. The emergent CT scan showed a large, 51 mL, intracerebral hemorrhage on left parieto-occipital lobe with midline shifting. The patient underwent emergent craniotomy, and a hypervascular tumor was identified during the operation. Histopathologic examination reported metastatic pulmonary blastoma, CBPB. The patient has been in a vegetative state, but there has been no evidence of recurrence over a 6-month follow-up period. We report a rare case of brain metastasis from CBPB presenting with altered mentality due to massive tumor bleeding. This is the only reported case of brain metastasis from CBPB presenting with acute intracerebral hemorrhage.

6.
Nat Commun ; 10(1): 2184, 2019 05 16.
Article in English | MEDLINE | ID: mdl-31097716

ABSTRACT

Chronic hepatitis B virus (HBV) infection can cause cirrhosis and hepatocellular carcinoma and is therefore a serious public health problem. Infected patients are currently treated with nucleoside/nucleotide analogs and interferon α, but this approach is not curative. Here, we screen 978 FDA-approved compounds for their ability to inhibit HBV replication in HBV-expressing HepG2.2.15 cells. We find that ciclopirox, a synthetic antifungal agent, strongly inhibits HBV replication in cells and in mice by blocking HBV capsid assembly. The crystal structure of the HBV core protein and ciclopirox complex reveals a unique binding mode at dimer-dimer interfaces. Ciclopirox synergizes with nucleoside/nucleotide analogs to prevent HBV replication in cells and in a humanized liver mouse model. Therefore, orally-administered ciclopirox may provide a novel opportunity to combat chronic HBV infection by blocking HBV capsid assembly.


Subject(s)
Antiviral Agents/pharmacology , Ciclopirox/pharmacology , Hepatitis B virus/physiology , Hepatitis B, Chronic/drug therapy , Virus Assembly/drug effects , Animals , Antiviral Agents/therapeutic use , Capsid/drug effects , Capsid/metabolism , Ciclopirox/chemistry , Ciclopirox/therapeutic use , Crystallography, X-Ray , Disease Models, Animal , Drug Evaluation, Preclinical , Drug Synergism , Hep G2 Cells , Hepatitis B virus/drug effects , Hepatitis B, Chronic/pathology , Hepatitis B, Chronic/virology , Hepatocytes/transplantation , Hepatocytes/virology , Humans , Male , Mice , Mice, Inbred BALB C , Mice, SCID , RNA, Viral/metabolism , Transplantation Chimera , Treatment Outcome , Viral Core Proteins/chemistry , Viral Core Proteins/metabolism , Virus Replication/drug effects
7.
RSC Adv ; 9(23): 13007-13015, 2019 Apr 25.
Article in English | MEDLINE | ID: mdl-35520792

ABSTRACT

Practical application of surface-enhanced Raman scattering (SERS)-active platforms requires that they provide highly uniform and reproducible SERS signals. Moreover, to achieve highly stable and consistent SERS signals, it is important to control the nanostructured gaps of SERS-active platforms precisely. Herein, we report the synthesis of gap-controllable nanoporous plates and their application to efficient, robust, uniform, and reproducible SERS-active platforms. To prepare well-defined nanoporous plates, ultraflat, ultraclean, and single-crystalline Au nanoplates were employed. The Au nanoplates were transformed to AuAg alloy nanoplates by reacting with AgI in the vapor phase. The Ag in the alloy nanoplates was then chemically etched, thus forming well-defined SERS-active nanoporous plates. For the precise control of gaps in the nanoporous plates, we investigated the alloy forming mechanism based on X-ray photoelectron spectroscopy and transmission electron microscopy analyses. According to the mechanism, the composition of Ag was tunable by varying the reaction temperature, thus making the nanostructured gaps of the porous plates adjustable. We optimized the nanoporous plates to exhibit the strongest SERS signals as well as excellent uniformity and reproducibility. The computational simulation also supports the experimental SERS signals of nanoporous plates. Furthermore, we successfully performed label-free detection of a biocide mixture (5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazol-3-one) up to 10 ppm using Au nanoporous plates. The adoption of single-crystalline Au nanoplates, the novel synthesis method for alloy nanoplates in the vapor phase, and the investigation of alloy forming mechanisms synergistically contributed to the formation of well-defined nanoporous plates. We anticipate that the nanoporous plates will be useful for the practical sensing of trace chemical and biological analytes.

8.
Stem Cells Dev ; 24(14): 1648-57, 2015 Jul 15.
Article in English | MEDLINE | ID: mdl-25745847

ABSTRACT

Interstitial cystitis (IC) is a syndrome characterized by urinary urgency, frequency, pelvic pain, and nocturia in the absence of bacterial infection or identifiable pathology. IC is a devastating disease that certainly decreases quality of life. However, the causes of IC remain unknown and no effective treatments or cures have been developed. This study evaluated the therapeutic potency of using human umbilical cord-blood-derived mesenchymal stem cells (UCB-MSCs) to treat IC in a rat model and to investigate its responsible molecular mechanism. IC was induced in 10-week-old female Sprague-Dawley rats via the instillation of 0.1 M HCl or phosphate-buffered saline (PBS; sham). After 1 week, human UCB-MSC (IC+MSC) or PBS (IC) was directly injected into the submucosal layer of the bladder. A single injection of human UCB-MSCs significantly attenuated the irregular and decreased voiding interval in the IC group. Accordingly, denudation of the epithelium and increased inflammatory responses, mast cell infiltration, neurofilament production, and angiogenesis observed in the IC bladders were prevented in the IC+MSC group. The injected UCB-MSCs successfully engrafted to the stromal and epithelial tissues and activated Wnt signaling cascade. Interference with Wnt and epidermal growth factor receptor activity by small molecules abrogated the benefits of MSC therapy. This is the first report that provides an experimental evidence of the therapeutic effects and molecular mechanisms of MSC therapy to IC using an orthodox rat animal model. Our findings not only provide the basis for clinical trials of MSC therapy to IC but also advance our understanding of IC pathophysiology.


Subject(s)
Cell- and Tissue-Based Therapy/methods , Cystitis, Interstitial/therapy , Mesenchymal Stem Cell Transplantation , Urination Disorders/therapy , Wnt Signaling Pathway/physiology , Animals , Cell Proliferation , Cells, Cultured , Epidermal Growth Factor/antagonists & inhibitors , Epidermal Growth Factor/metabolism , Female , Fetal Blood/cytology , Humans , Mesenchymal Stem Cells/cytology , Rats , Rats, Sprague-Dawley , Urinary Bladder/physiopathology , Urination/physiology , Wnt Proteins/antagonists & inhibitors , Wnt Proteins/metabolism
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