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1.
ACS Nano ; 18(10): 7558-7569, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38420914

ABSTRACT

Water electrolysis is emerging as a promising renewable-energy technology for the green production of hydrogen, which is a representative and reliable clean energy source. From economical and industrial perspectives, the development of earth-abundant non-noble metal-based and bifunctional catalysts, which can simultaneously exhibit high catalytic activities and stabilities for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), is critical; however, to date, these types of catalysts have not been constructed, particularly, for high-current-density water electrolysis at the industrial level. This study developed a heterostructured zero-dimensional (0D)-one-dimensional (1D) PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF)-Ni3S2 as a self-supported catalytic electrode via interface and morphology engineering. This unique heterodimensional nanostructure of the PBSCF-Ni3S2 system demonstrates superaerophobic/superhydrophilic features and maximizes the exposure of the highly active heterointerface, endowing the PBSCF-Ni3S2 electrode with outstanding electrocatalytic performances in both HER and OER and exceptional operational stability during the overall water electrolysis at high current densities (500 h at 500 mA cm-2). This study provides important insights into the development of catalytic electrodes for efficient and stable large-scale hydrogen production systems.

2.
Sci Rep ; 13(1): 14668, 2023 09 06.
Article in English | MEDLINE | ID: mdl-37674003

ABSTRACT

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease, is a widespread liver condition characterized by excessive fat buildup in hepatocytes without significant alcohol consumption. Manipulation of the gut microbiome has been considered to prevent and improve the occurrence and progression of MASLD, particularly through the gut-liver axis. This study aimed to investigate the correlation between the gut microbiome and liver function and determine whether the gut microbiome can ameliorate MASLD. We comparatively analyzed the gut microbiome composition between mice fed normal chow and those fed a high-fat diet and observed that the abundance of Kineothrix alysoides decreased in the high-fat group. Further analysis showed that treatment with K. alysoides in the high-fat diet group led to decreased weight loss, and MASLD attenuation. Importantly, K. alysoides treatment attenuated MASLD in mice fed a high-fat, high-fructose diet (HFHF), which can cause advanced liver damage. Furthermore, administration of K. alysoides altered the gut microbial composition in the HFHF diet group and improved MASLD. Overall, these findings demonstrate the potential of K. alysoides in restoring gut health and facilitating lipid metabolism to prevent and treat MASLD.


Subject(s)
Gastrointestinal Microbiome , Non-alcoholic Fatty Liver Disease , Animals , Mice , Lipid Metabolism , Clostridiales
3.
Tissue Eng Regen Med ; 20(1): 49-58, 2023 02.
Article in English | MEDLINE | ID: mdl-36374371

ABSTRACT

BACKGROUND: Microplastics (MPs) are small fragments from any type of plastic formed from various sources, including plastic waste and microfibers from clothing. MPs degrades slowly, resulting in a high probability of human inhalation, ingestion and accumulation in bodies and tissues. As its impact on humans is a prolonged event, the evaluation of its toxicity and influence on human health are critical. In particular, MPs can enter the human digestive system through food and beverage consumption, and its effect on the human colon needs to be carefully examined. METHODS: We monitored the influence of small MPs (50 and 100 nm) on human colon cells, human colon organoids and also examined their toxicity and changes in gene expression in vivo in a mouse model. RESULTS: The data suggested that 5 mg/mL concentrations of 50 and 100 nm MPs induced a > 20% decrease in colon organoid viability and an increase in the expression of inflammatory-, apoptosis- and immunity-related genes. In addition, in vivo data suggested that 50 nm MPs accumulate in various mouse organs, including the colon, liver, pancreas and testicles after 7 d of exposure. CONCLUSION: Taken together, our data suggest that smaller MPs can induce more toxic effects in the human colon and that human colon organoids have the potential to be used as a predictive tool for colon toxicity.


Subject(s)
Microplastics , Plastics , Humans , Mice , Animals , Microplastics/toxicity , Plastics/toxicity , Colon , Apoptosis , Organoids
4.
PLoS One ; 17(12): e0279196, 2022.
Article in English | MEDLINE | ID: mdl-36534676

ABSTRACT

BACKGROUND: Non-occlusive mesenteric ischemia (NOMI) is a life-threatening acute condition that has an overall in-hospital mortality rate of up to 75%. Critically ill patients are often admitted to intensive care units (ICUs) due to shock, and these patients are frequently at risk of developing NOMI. The objective of this study was to determine the clinical features of critically ill patients with NOMI and evaluate the risk factors for in-hospital mortality among these patients. METHODS: We reviewed the electronic medical records of 7,346 patients who underwent abdominal contrast-enhanced computed tomography during their ICU stay at Samsung Medical Center (Seoul, Korea) between January 1, 2010 and December 31, 2019. After reviewing each patient's computed tomography (CT) scans, 60 patients were diagnosed with NOMI and included in this analysis. The patients were divided into survivor (n = 23) and non-survivor (n = 37) groups according to the in-hospital mortality. RESULTS: The overall sequential organ failure assessment (SOFA) score for the included patients upon admission to the ICU was 8.6 ± 3.1, and medical ICU admissions were most common (66.7%) among the patients. The SOFA score upon admission to the ICU was higher for the non-survivors than for the survivors (9.4 vs. 7.4; p = 0.017). Non-survivors were more often observed in the medical ICU admissions (39.1% vs. 83.8%) than in the surgical ICU admissions (47.8% vs. 10.8%) or the cardiac ICU admissions (13.0% vs. 5.4%). Laboratory test results, abdominal CT findings, and the use of vasopressors and inotropes did not differ between the two groups. In a multivariable analysis, SOFA scores >8 upon admission to the ICU (odds ratio [OR] 4.51; 95% 1.12-18.13; p = 0.034), patients admitted to the ICU with medical problems (OR 7.99; 95% 1.73-36.94; p = 0.008), and abdominal pain (OR 4.26; 95% 1.05-17.35; p = 0.043) were significant prognostic predictors for in-hospital mortality. CONCLUSIONS: The SOFA score >8 upon admission to the ICU, admission to the ICU for medical problems, and abdominal pain at diagnosis are associated with increased mortality among patients with NOMI.


Subject(s)
Critical Illness , Mesenteric Ischemia , Humans , Hospital Mortality , Hospitalization , Intensive Care Units , Organ Dysfunction Scores , Prognosis , Retrospective Studies
5.
J Microbiol ; 60(7): 715-726, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35781626

ABSTRACT

Nitric oxide (NO) is a reactive nitrogen species (RNS) that plays a vital role in regulating inflammatory processes. Under abnormal conditions, excessive NO levels can promote the oxidation of cellular components, which may cause or exacerbate diseases such as hypertension, cardiovascular dysfunction, and inflammatory bowel disease (IBD). Previous studies have shown that reducing NO levels in the lumen can attenuate the clinical symptoms of IBD. Thus, we aimed to identify bacteria that can reduce RNS and that can be used as valuable probiotics. In this study, we isolated bacteria resistant to nitrite stress from human feces and used 16S and whole-genome sequencing to identify them as Lactiplantibacillus plantarum LP7 (LP7). The ability to survive at high nitrite levels and to decrease them was greater in the LP7 strain than in the reference strain L. plantarum ATCC14917 (ATCC14917). To characterize the LP7 genome in more detail, we performed a comparative genome analysis. However, the unique genes that directly confer the ability to withstand nitrite stress were not present in the LP7 genome. Furthermore, we performed transcriptomic analysis of LP7 and ATCC14917 cells treated with nitrite. We found that the expression levels of genes involved in the cell division process were induced in LP7, which showed a more regular rod-shape than ATCC14917. This could explain why LP7 can survive better than ATCC14917 under nitrite stress. Based on its ability to survive better in nitrite stress and decrease nitrite concentration, we suggest that LP7 could be a valuable probiotic strain.


Subject(s)
Inflammatory Bowel Diseases , Lactobacillus plantarum , Probiotics , Gene Expression Profiling , Humans , Lactobacillus plantarum/metabolism , Nitrites
6.
Nanomaterials (Basel) ; 12(9)2022 Apr 28.
Article in English | MEDLINE | ID: mdl-35564208

ABSTRACT

Here, a highly sensitive triboelectric bending sensor in non-contact mode operation, less sensitive to strain, is demonstrated by designing multiple triangular prisms at both sides of the polydimethylsiloxane film. The sensor can detect bending in a strained condition (up to 20%) as well as bending direction with quite high linear sensitivity (~0.12/degree) up to 120°, due to the electrostatic induction effect between Al and poly (glycerol sebacate) methacrylate. Further increase of the bending angle to 135° significantly increases the sensitivity to 0.16/degree, due to the contact electrification between them. The sensors are attached on the top and bottom side of the proximal interphalangeal and wrist, demonstrating a directional bending sensor with an enhanced sensitivity.

7.
ACS Appl Mater Interfaces ; 14(16): 18248-18260, 2022 Apr 27.
Article in English | MEDLINE | ID: mdl-35413181

ABSTRACT

The efficient realization of bifunctional catalysts has immense opportunities in energy conversion technologies such as water splitting. Transition metal dichalcogenides (TMDs) are considered excellent hydrogen evolution catalysts owing to their hierarchical atomic-scale layered structure and feasible phase transition. On the other hand, for efficient oxygen evolution, perovskite oxides offer the best performance based on their rational design and flexible compositional structure. A unique way to achieve an efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in a single-cell configuration is through the hybridization of TMDs with perovskite oxides to form a bifunctional electrocatalyst. Here, we report a simple yet effective strategy to inherently tune the intrinsic properties of a TMD based on MoS2 and its hybridization with LaCoO3 perovskite oxide to deliver enhanced electrocatalytic activity for both the HER and OER. Detailed Raman and XPS measurements highlighted a clear phase transformation of MoS2 from a semiconducting to metallic phase by effectively tailoring the precursor compositions. Based on this, the morphological features yielded an interesting spherical flower-shaped nanostructure with vertically aligned petals of MoS2 with increased surface-active edge sites suitable for the HER. Subsequent hybridization of nanostructured MoS2 with LaCoO3 provides a bifunctional catalytic system with an increased BET surface area of 33.4 m2/g for an overall improvement in water splitting with a low onset potential (HER: 242 mV and OER: 1.6 V @10 mA cm-2) and Tafel slope (HER: 78 mV dec-1; OER: 62.5 mV dec-1). Additionally, the bifunctional catalyst system exhibits long-term stability of up to ∼400 h under continuous operation at a high current density of 50 mA cm-2. These findings will pave the way for developing cost-effective and less complex bifunctional catalysts by simply and inherently tuning the influential material properties for full-cell electrochemical water splitting.

8.
J Pharmacol Sci ; 148(4): 377-386, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35300813

ABSTRACT

Metabolic syndrome is increasingly common, and closely related with overweight or obesity. In the obese state, macrophages infiltrate to the adipose tissue (AT), resulting in chronic inflammation and insulin resistance in the AT cells. Recently, attention has been paid to the role of AT macrophages in metabolic disorders should be applied to the initial drug screening step, but it was difficult to mimic the inflammatory adipocytes using the traditional 2-dimensional (2D) culture. In this study, we developed the 3-dimensional (3D) culture system to overcome this limitation. After adipogenic differentiation, lipid droplets were highly accumulated in cells, and differentiation of preadipocytes was not declined by macrophage co-culture. However, only co-cultured cells expressed the insulin resistance features. Compare to mono-cultured adipocytes, co-cultured adipocytes showed reduced glucose uptake and GLUT4 did not translocated to cell membrane even though treatment of high concentration of insulin. Using 3D co-culture model, we develop a microwell-scale drug screening protocol to test anti-obesity effect. 3D cultured cells reacted more sensitive to drugs, and PPARγ antagonist GW9662 (10, 20 µM) repressed adipogenic differentiation in a concentration-dependent manner in 3D co-cultured cells.


Subject(s)
Metabolic Syndrome , Adipocytes , Adipogenesis , Drug Evaluation, Preclinical , Humans , Metabolic Syndrome/drug therapy , Metabolic Syndrome/etiology , Metabolic Syndrome/metabolism , Obesity/drug therapy
9.
Adv Sci (Weinh) ; 9(12): e2104915, 2022 04.
Article in English | MEDLINE | ID: mdl-35199951

ABSTRACT

A wearable thermoelectric generator (WTEG) that utilizes human body heat can be a promising candidate for the wearable power generators. The temperature difference (ΔT) between the body and the environment is a stable source driving the WTEG, but this driving force is limited by the ambient temperature itself at the same time. Here, a novel WTEG that can be operated using the dual source of body heat and light with exceptionally high driving force is fabricated. The printable solar absorbing layer attached to the bottom of the WTEG absorbs ≈95% of the light from ultraviolet to far infrared and converts it into heat. To optimize the power density of WTEGs, the fill factor of the thermoelectric (TE) leg/electrode is considered through finite-difference time-domain (FDTD) simulation. When operated by the dual sources, the WTEG exhibits a power density of 15.33 µW cm-2 , which is the highest under "actual operating conditions" among all kinds of WTEGs. In addition, unlike conventional WTEGs, the WTEG retains 83.1% of its output power at an ambient temperature of 35 °C compared to its output power at room temperature. This study will accelerate the commercialization of WTEGs by introducing a novel method to overcome their limitations.


Subject(s)
Hot Temperature , Wearable Electronic Devices , Electric Power Supplies , Electrodes , Humans , Sunlight
10.
J Korean Med Sci ; 35(23): e168, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32537949

ABSTRACT

Philadelphia-negative (Ph-) classical myeloproliferative neoplasms (MPNs) include polycythemia vera, essential thrombocythemia (ET), and primary myelofibrosis. Somatic driver mutations in the JAK2, CALR, and MPL genes serve as major diagnostic criteria of the Ph- MPNs and these mutations occur in a mutually exclusive manner. In this report, we describe the first case of ET harboring double mutations in JAK2 V617F and MPL. For MPL, the patient had multiple clones of MPL mutations: c.1543_1546delinsAGGG (p.Trp515_Gln516delinsArgGlu) and c.1546C>G (p.Gln516Glu). The JAK2 V617F allele burden in our patient is very low (4%) compared to the relatively high (17%-78%) allele frequency of MPL mutations. The low JAK2 mutant burden might be explained by preexisting clonal hematopoiesis before overt signs of MPNs, followed by the acquisition of a second oncogenic mutation of CALR or MPL leading to the MPN phenotype. This highlights that screening for a second driver mutation should be considered in patients with a low JAK2 mutant burden by reporting a 57-year-old Korean man with ET.


Subject(s)
Janus Kinase 2/genetics , Receptors, Thrombopoietin/genetics , Thrombocythemia, Essential/diagnosis , Base Sequence , Bone Marrow/pathology , Humans , Male , Middle Aged , Mutation , Phenotype , Thrombocythemia, Essential/genetics
11.
Int J Mol Sci ; 21(10)2020 May 25.
Article in English | MEDLINE | ID: mdl-32466320

ABSTRACT

Dry eye syndrome is the most common eye disease and it is caused by various reasons. As the balance of the tear film that protects the eyes is broken due to various causes, it becomes impossible to properly protect the eyes. In this study, the protective effects and underlying mechanisms of topical (E)-4-(2-(6-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-methyl-1,1-dioxido-1,2,6-thiadiazinan-2-yl)acetamido)adamantan-1-carboxamide (KR-67607), a novel selective 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) inhibitor, were investigated in benzalkonium chloride (BAC)-induced dry eye syndrome. BAC-treated rat eyes induced significant increases in ocular surface damage, decreased corneal thickness, corneal basement membrane destruction in the conjunctival epithelium, and expression of pro-inflammatory cytokines tumor necrosis factor-α and 11ß-HSD1. These effects of BAC were reversed by topical KR-67607 treatment. Furthermore, KR-67607 decreased 4-hydroxynonenal expression and increased antioxidant and mucus secretion in BAC-treated rat eyes. Taken together, a novel selective 11ß-HSD1 inhibitor can prevent BAC-induced dry eye syndrome by inhibiting pro-inflammatory cytokine and reactive oxygen species expression via the inhibition of both 11ß-HSD1 activity and expression.


Subject(s)
Adamantane/analogs & derivatives , Antioxidants/therapeutic use , Dry Eye Syndromes/drug therapy , Enzyme Inhibitors/therapeutic use , Thiadiazines/therapeutic use , 11-beta-Hydroxysteroid Dehydrogenase Type 1/antagonists & inhibitors , 11-beta-Hydroxysteroid Dehydrogenase Type 1/metabolism , Adamantane/pharmacology , Adamantane/therapeutic use , Animals , Antioxidants/pharmacology , Benzalkonium Compounds/toxicity , Conjunctiva/drug effects , Conjunctiva/metabolism , Dry Eye Syndromes/etiology , Dry Eye Syndromes/prevention & control , Enzyme Inhibitors/pharmacology , NF-kappa B/metabolism , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Thiadiazines/pharmacology
12.
Diabetes Obes Metab ; 22(8): 1302-1315, 2020 08.
Article in English | MEDLINE | ID: mdl-32173999

ABSTRACT

AIM: Insulin resistance is a metabolic state where insulin sensitivity is lower than normal condition and strongly related to type 2 diabetes. However, an in vitro model mimicking insulin resistance is rare and thus screening drugs for insulin resistance severely depends on an in vivo model. Here, to increase anti-diabetic drug selectivity for humans, 3D ADMSCs and macrophages were co-cultured with in-house fabricated co-culture plates. MATERIAL AND METHODS: 3D co-culture plates were designed to load ADMSCs and RAW264.7 cells containing hydrogels in separate wells while allowing cell-cell interaction with co-culturing media. Hydrogels were constructed using a 3D cell-printing system containing 20 mg/ml alginate, 0.5 mg/ml gelatin and 0.5 mg/ml type I collagen. Cells containing hydrogels in 3D co-culture plates were incubated for 10 min to allow stabilization before the experiment. 3D co-culture plates were incubated with the CaCl2 solution for 5 min to complete the cross linking of alginate hydrogel. Cells in 3D co-culture plates were cultured for up to 12 days depending on the experiment and wells containing adipocytes and macrophages were separated and used for assays. RESULTS: KR-1, KR-2 and KR-3 compounds were applied during differentiation (12 days) in 3D co-cultured mouse 3T3-L1 adipocytes and 3D co-cultured human ADMSCs. Glucose uptake assay using 2-DG6P and 2-NBDG and western blot analysis were performed to investigate changes of insulin resistance in the 3D co-cultured model for interspecies selectivity of drug screening. KR-1 (mouse potent enantiomer) and KR-3 (racemic mixture) showed improvement of 2-DG and 2-NBDG uptake compared with KR-2 (human potent enantiomer) in 3D co-cultured 3T3-L1 adipocytes. In connection with insulin resistance in a 3D 3T3-L1 co-cultured model, KR-1 and KR-3 showed improvement of insulin sensitivity compared to KR-2 by markedly increasing GLUT4 expression. In contrast to the result of 3D co-cultured 3T3-L1 adipocytes, KR-1 failed to significantly improve 2-DG and 2-NBDG uptake in 3D co-cultured ADMSC adipocytes. Results of 2-NBDG accumulation and western blot analysis also showed that KR-2 and KR-3 improved insulin sensitivity relatively better than KR-1. CONCLUSIONS: Our 3D co-culture model with/without 3D co-culture plates can successfully mimic insulin resistance while allowing investigation of the effects of anti-obesity or anti-diabetic drugs on human or mouse co-culturing cell type. This 3D co-culture system may accelerate screening of drugs for insulin resistance depending on species.


Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , Pharmaceutical Preparations , 3T3-L1 Cells , Adipocytes , Animals , Coculture Techniques , Glucose , Humans , Insulin , Mice
13.
Sci Total Environ ; 712: 136574, 2020 Apr 10.
Article in English | MEDLINE | ID: mdl-32050388

ABSTRACT

Although zinc oxide nanorod (ZnO NR) arrays are a nanomaterial that offers efficient bactericidal activity, they have not been systematically evaluated to quantitatively investigate their disinfection mechanism under dark conditions. In this study, ZnO NR arrays of different lengths (0.5-4 µm) were uniformly grown via hydrothermal synthesis. The longer arrays exhibited higher Escherichia coli (E. coli) inactivation efficiency up to 94.2% even under darkness for 30 min. When the NR arrays were coated via Al2O3 atomic layer deposition, the inactivation efficiency was decreased to 56.4% because the generation of reactive oxygen species (ROS) and the leaching of Zn2+ ions were both hindered by the surficial coverage of defect sites. The morphological effect, i.e., the mechanical rupture of E. coli on the surface, contributed 56.4% of the bactericidal efficiency; chemical effects, i.e., ROS formation and zinc ion release, contributed the remaining 37.8% under dark conditions. The bactericidal effect of fabricated ZnO NR arrays was further validated in bottled and pond water spiked with E. coli, exhibiting 87.5% and 80.4% inactivation efficiencies, respectively, within 30 min. Understanding these antibacterial mechanisms is not only of significance for research in this and related fields but also beneficial for potential application in various fields, e.g., biomedical and antifouling areas.


Subject(s)
Nanotubes , Anti-Bacterial Agents , Escherichia coli , Zinc , Zinc Oxide
14.
Transfus Apher Sci ; 59(1): 102631, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31585831

ABSTRACT

BACKGROUND: Massive transfusion protocol (MTP) has been used to provide plasma and packed red blood cells (pRBCs) rapidly. MTP also has been adapted for non-traumatic patients. The effects of hospital-wide MTP implementation on clinical outcomes were reviewed. METHODS: This was a retrospective study of patients who received massive transfusion before and after MTP implementation, between August 2010 and May 2018. Massive transfusion was defined as 10 or more units of pRBCs within 24 h. Recipients of massive transfusion were divided into periods before and after MTP implementation. The 24 -h death rate, thirty-day death rate and several laboratory findings were investigated. RESULTS: Eighty patients whose massive transfusion occurred before MTP implementation and 63 patients whose massive transfusion occurred after MTP implementation were compared. No statistically significant difference was found in 24 -h death rate (15.0% vs. 23.8%, p = 0.181), or 30-day death rate (43.8% vs. 36.5%, p = 0.381). Use of an anti-fibrinolytic agent was more frequent in patients after the MTP implementation (31.3% vs. 55.6%, p = 0.003). A statistically significant difference was found in the lowest body temperature of the two groups during the 24 -h period (34.7 °C vs. 35.6 °C, p < 0.001). Transfusion ratio of plasma to pRBC was numerically improved after the MTP implementation (1:1.91 vs. 1:1.58, p = 0.173). Earlier initiation of pRBC transfusion was achieved after implementation (51 min vs. 40 min, p = 0.042). CONCLUSIONS: MTP implementation showed improved coagulation profiles, but did not show a statistically significant death-rate reduction in non-traumatic patients.


Subject(s)
Blood Transfusion/methods , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies
15.
Light Sci Appl ; 8: 121, 2019.
Article in English | MEDLINE | ID: mdl-31871673

ABSTRACT

Transparent solar cells (TSCs) are emerging devices that combine the advantages of visible transparency and light-to-electricity conversion. Currently, existing TSCs are based predominantly on organics, dyes, and perovskites; however, the rigidity and color-tinted transparent nature of those devices strongly limit the utility of the resulting TSCs for real-world applications. Here, we demonstrate a flexible, color-neutral, and high-efficiency TSC based on a freestanding form of n-silicon microwires (SiMWs). Flat-tip SiMWs with controllable spacing are fabricated via deep-reactive ion etching and embedded in a freestanding transparent polymer matrix. The light transmittance can be tuned from ~10 to 55% by adjusting the spacing between the microwires. For TSCs, a heterojunction is formed with a p-type polymer in the top portion of the n-type flat-tip SiMWs. Ohmic contact with an indium-doped ZnO film occurs at the bottom, and the side surface has an Al2O3 passivation layer. Furthermore, slanted-tip SiMWs are developed by a novel solvent-assisted wet etching method to manipulate light absorption. Finite-difference time-domain simulation revealed that the reflected light from slanted-tip SiMWs helps light-matter interactions in adjacent microwires. The TSC based on the slanted-tip SiMWs demonstrates 8% efficiency at a visible transparency of 10% with flexibility. This efficiency is the highest among Si-based TSCs and comparable with that of state-of-the-art neutral-color TSCs based on organic-inorganic hybrid perovskite and organics. Moreover, unlike others, the stretchable and transparent platform in this study is promising for future TSCs.

16.
Sci Rep ; 9(1): 16746, 2019 11 14.
Article in English | MEDLINE | ID: mdl-31727937

ABSTRACT

The demand for novel three-dimensional (3D) cell culture models of adipose tissue has been increasing, and proteomic investigations are important for determining the underlying causes of obesity, type II diabetes, and metabolic disorders. In this study, we performed global quantitative proteomic profiling of three 3D-cultured 3T3-L1 cells (preadipocytes, adipocytes and co-cultured adipocytes with macrophages) and their 2D-cultured counterparts using 2D-nanoLC-ESI-MS/MS with iTRAQ labelling. A total of 2,885 shared proteins from six types of adipose cells were identified and quantified in four replicates. Among them, 48 proteins involved in carbohydrate metabolism (e.g., PDHα, MDH1/2, FH) and the mitochondrial fatty acid beta oxidation pathway (e.g., VLCAD, ACADM, ECHDC1, ALDH6A1) were relatively up-regulated in the 3D co-culture model compared to those in 2D and 3D mono-cultured cells. Conversely, 12 proteins implicated in cellular component organisation (e.g., ANXA1, ANXA2) and the cell cycle (e.g., MCM family proteins) were down-regulated. These quantitative assessments showed that the 3D co-culture system of adipocytes and macrophages led to the development of insulin resistance, thereby providing a promising in vitro obesity model that is more equivalent to the in vivo conditions with respect to the mechanisms underpinning metabolic syndromes and the effect of new medical treatments for metabolic disorders.


Subject(s)
Adipocytes/cytology , Coculture Techniques/methods , Macrophages/cytology , Proteomics/methods , Spheroids, Cellular/cytology , 3T3-L1 Cells , Adipocytes/metabolism , Animals , Carbohydrate Metabolism , Chromatography, Liquid , Gene Expression Regulation , Gene Regulatory Networks , Insulin Resistance , Macrophages/metabolism , Mice , Models, Biological , Nanotechnology , RAW 264.7 Cells , Tandem Mass Spectrometry
17.
Biochem Pharmacol ; 169: 113632, 2019 11.
Article in English | MEDLINE | ID: mdl-31494147

ABSTRACT

Glaucoma is one of the leading causes of preventable blindness, affecting > 2 million people in the United States. Recently, 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) inhibitors were found to exert preventive effects against glaucoma. However, there is no evidence for the role of 11ß-HSD1 inhibitors against glaucoma. Here, we developed a novel 11ß-HSD1 inhibitor, (1R,2S,3S,5R,6S,7S)-6-(2-(6-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-methyl-1,1-dioxido-1,2,6-thiadiazinan-2-yl)acetamido)-adamantane-2-carboxamide (KR-67607) and showed its protective effects against ischemia-reperfusion-induced eye injury. We demonstrate that KR-67607 effectively reduced cortisol levels in mouse eyes and maintained the trabecular meshwork (TM) structure in the presence of transient ischemic stress. Furthermore, KR-67607 reversed the elevation of intra-ocular pressure (IOP), suggesting that the TM structure maintained by KR-67607 prevented the excessive rise in IOP that exacerbates glaucoma. KR-67607 was shown to have a higher specificity for 11ß-HSD1 than carbenoxolone (CBX) in vitro. Moreover, KR-67607 reduced apoptosis and the structural disruption of TM cells. Antioxidation was the major protective pathway of KR-67607 against chemically-induced ischemia-reperfusion in TM cells and the glucocorticoid receptor (GR) was closely associated with this pathway. When TM cells undergo ischemic stress, GR is activated and then translocates to the cell nucleus where it interferes with Nrf-2-mediated antioxidant gene expression. However, when KR-67607 inhibited GR translocation, Nrf-2 was able to induce antioxidant gene transcription, which consequently, enhanced the antioxidant capacity of the cells. In conclusion, our current work describes a novel selective 11ß-HSD1 inhibitor for glaucoma treatment and provides evidence of its physiological role in anti-oxidative pathways in the TM.


Subject(s)
11-beta-Hydroxysteroid Dehydrogenase Type 1/antagonists & inhibitors , Adamantane/analogs & derivatives , Eye/blood supply , Glaucoma/drug therapy , Reperfusion Injury/prevention & control , Thiadiazines/pharmacology , Adamantane/pharmacology , Adamantane/therapeutic use , Animals , Carbenoxolone/pharmacology , Intraocular Pressure/drug effects , Male , Mice , Mice, Inbred C57BL , NF-E2-Related Factor 2/physiology , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Receptors, Glucocorticoid/physiology , Thiadiazines/therapeutic use , Trabecular Meshwork/drug effects
18.
Int Urol Nephrol ; 51(7): 1231-1238, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31134506

ABSTRACT

PURPOSE: The number of elderly patients with end-stage renal disease on maintenance dialysis therapy is gradually increasing. The elderly population has difficulties in making decisions regarding initiation of dialysis treatment because of their high morbidity and frailty. The purpose of this study was to determine the best prognostic tool in predicting short-term mortality in elderly patients undergoing dialysis. METHODS: This study is a multicenter retrospective study. We enrolled patients, aged ≥ 75 years, who began hemodialysis at three university hospitals in Korea from January 2010 to December 2016. We applied two comorbidity-based score tools (Thamer and Wick, each consisting of seven variables) and the Clinical Frailty Scale (CFS, seven scales), which were validated for mortality prediction in elderly incident patients. Patient's information was obtained from electronic medical records in the participating center, and mortality data (up to December 2016) were obtained from the Korean National Statistical Office. Models were compared using the area under the receiver operating characteristic curve. RESULTS: Among the 219 patients enrolled in this study, the 3- and 6-month mortality rates were 31 (14.4%) and 48 (22.4%), respectively. Receiver operating characteristic curve analysis revealed that both score systems and the CFS showed similar performance while predicting 3- and 6-month mortality. The scores from these indices correlated with survival time. CONCLUSION: Predicting short-term mortality and long-term survival time for elderly patients is possible using the Thamer and Wick scores and the CFS.


Subject(s)
Frailty , Geriatric Assessment/methods , Kidney Failure, Chronic , Multiple Chronic Conditions/epidemiology , Renal Dialysis , Risk Assessment/methods , Aged , Female , Frailty/diagnosis , Frailty/epidemiology , Humans , Kidney Failure, Chronic/diagnosis , Kidney Failure, Chronic/epidemiology , Kidney Failure, Chronic/therapy , Male , Mortality , Prognosis , Renal Dialysis/adverse effects , Renal Dialysis/methods , Renal Dialysis/mortality , Reproducibility of Results , Republic of Korea/epidemiology , Research Design/standards , Research Design/statistics & numerical data , Risk Factors , Survivors/statistics & numerical data
19.
Nano Lett ; 19(2): 971-976, 2019 02 13.
Article in English | MEDLINE | ID: mdl-30608699

ABSTRACT

Organic-inorganic hybrid perovskites have been investigated extensively for use in perovskite-based solar cells and light-emitting diodes (LEDs) because of their excellent electrical and optical properties. Although the flexibility of perovskite LEDs has been studied through empirical methods such as cyclic bending tests, the flexibility of the perovskite layer has not been investigated systemically. Here, flexible and semitransparent perovskite LEDs are fabricated: a PEDOT:PSS anode and Ag nanowire cathode allow for flexible and semitransparent devices, while the use of a conjugated polyelectrolyte as an interfacial layer reduces the electron injection barrier between the cathode and the electron transport layer (SPW-111), resulting in enhanced device efficiency. Cyclic bending tests performed on the electrodes and in situ hole-nanoindentation tests performed on the constituent materials suggest that mechanical failure occurs in the perovskite MAPbBr3 layer during cyclic bending, leading to a decrease in the luminance. Tensile properties of the MAPbBr3 layer explain the critical bending radius ( rb) of the perovskite LEDs on the order of 1 mm.

20.
Adv Sci (Weinh) ; 5(9): 1800816, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30250810

ABSTRACT

Room-temperature (RT) gas sensitivity of morphology-controlled free-standing hollow aluminum-doped zinc oxide (AZO) nanofibers for NO2 gas sensors is presented. The free-standing hollow nanofibers are fabricated using a polyvinylpyrrolidone fiber template electrospun on a copper electrode frame followed by radio-frequency sputtering of an AZO thin overlayer and heat treatment at 400 °C to burn off the polymer template. The thickness of the AZO layer is controlled by the deposition time. The gas sensor based on the hollow nanofibers demonstrates fully recoverable n-type RT sensing of low concentrations of NO2 (0.5 ppm). A gas sensor fabricated with Al2O3-filled AZO nanofibers exhibits no gas sensitivity below 75 °C. The gas sensitivity of a sensor is determined by the density of molecules above the minimum energy for adsorption, collision frequency of gas molecules with the surface, and available adsorption sites. Based on finite-difference time-domain simulations, the RT sensitivity of hollow nanofiber sensors is ascribed to the ten times higher collision frequency of NO2 molecules confined inside the fiber compared to the outer surface, as well as twice the surface area of hollow nanofibers compared to the filled ones. This approach might lead to the realization of RT sensitive gas sensors with 1D nanostructures.

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