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Inflammatory bowel disease is defined by inflammation and immune dysregulation. This study investigated the effects of Gα13 liver-specific knockout (LKO) on proximal and distal colons of dextran sodium sulfate (DSS)-induced mice in conjunction with a high-fat diet (HFD). HFD improved body weight gain and disease activity index scores. Gα13LKO exerted no improvement. In the proximal colon, HFD augmented the DSS effect on Il6, which was not observed in Gα13LKO mice. In the distal colon, HFD plus DSS oppositely fortified an increase in Tnfa and Cxcl10 mRNA in Gα13LKO but not WT. Il6 levels remained unchanged. Bioinformatic approaches using Gα13LKO livers displayed bile acid and cholesterol metabolism-related gene sets. Cholic acid and chenodeoxycholic acid levels were increased in the liver of mice treated with DSS, which was reversed by Gα13LKO. Notably, mice treated with DSS showed a reduction in hepatic ABCB11, CYP7B1, CYP7A1, and CYP8B1, which was reversed by Gα13LKO. Overall, feeding HFD augments the effect of DSS on Il6 in the proximal colon of WT, but not Gα13LKO mice, and enhances DSS effect on Tnfa and Cxcl10 in the distal colon of Gα13LKO mice, suggesting site-specific changes in the inflammatory cytokines, potentially resulting from changes in BA synthesis and excretion.
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Ácidos e Sais Biliares , Colo , Sulfato de Dextrana , Fígado , Animais , Masculino , Camundongos , Ácidos e Sais Biliares/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Colite/genética , Colite/patologia , Colo/metabolismo , Colo/patologia , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/induzido quimicamente , Interleucina-6/metabolismo , Interleucina-6/genética , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genéticaRESUMO
[This corrects the article DOI: 10.1007/s10068-023-01464-1.].
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Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited performance (e.g., low carrier mobility), in part, due to their high contact resistances caused by interfacing non-vdW three-dimensional (3D) metal electrodes. Herein, we report that this intrinsic contact issue can be efficiently mitigated by forming the 2D/2D in-plane junctions of 2D semiconductor channels seamlessly interfaced with 2D metal electrodes. For this, we demonstrated the selectively patterned conversion of semiconducting 2D PtSe2 (channels) to metallic 2D PtTe2 (electrodes) layers by employing a wafer-scale low-temperature chemical vapor deposition (CVD) process. We investigated a variety of field-effect transistors (FETs) employing wafer-scale CVD-2D PtSe2/2D PtTe2 heterolayers and identified that silicon dioxide (SiO2) top-gated FETs exhibited an extremely high hole mobility of â¼120 cm2 V-1 s-1 at room temperature, significantly surpassing performances with previous wafer-scale 2D PtSe2-based FETs. The low-temperature nature of the CVD method further allowed for the direct fabrication of wafer-scale arrays of 2D PtSe2/2D PtTe2 heterolayers on polyamide (PI) substrates, which intrinsically displayed optical pulse-induced artificial synaptic behaviors. This study is believed to vastly broaden the applicability of 2D TMD layers for next-generation, high-performance electronic devices with unconventional functionalities.
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Amylosucrase (ASase) efficiently biosynthesizes α-glucoside using flavonoids as acceptor molecules and sucrose as a donor molecule. Here, ASase from Deinococcus wulumuqiensis (DwAS) biosynthesized more naringenin α-glucoside (NαG) with sucrose and naringenin as donor and acceptor molecules, respectively, than other ASases from Deinococcus sp. The biotransformation rate of DwAS to NαG was 21.3% compared to 7.1-16.2% for other ASases. Docking simulations showed that the active site of DwAS was more accessible to naringenin than those of others. The 217th valine in DwAS corresponded to the 221st isoleucine in Deinococcus geothermalis AS (DgAS), and the isoleucine possibly prevented naringenin from accessing the active site. The DwAS-V217I mutant had a significantly lower biosynthetic rate of NαG than DwAS. The kcat/Km value of DwAS with naringenin as the donor was significantly higher than that of DgAS and DwAS-V217I. In addition, NαG inhibited human intestinal α-glucosidase more efficiently than naringenin.
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Proteínas de Bactérias , Biotransformação , Deinococcus , Flavanonas , Glucosídeos , Glucosiltransferases , Inibidores de Glicosídeo Hidrolases , Flavanonas/metabolismo , Flavanonas/química , Deinococcus/enzimologia , Deinococcus/metabolismo , Deinococcus/química , Deinococcus/genética , Glucosiltransferases/metabolismo , Glucosiltransferases/química , Glucosiltransferases/genética , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Glucosídeos/metabolismo , Glucosídeos/química , Simulação de Acoplamento Molecular , Cinética , alfa-Glucosidases/metabolismo , alfa-Glucosidases/químicaRESUMO
With the rapid growth of the elderly population, the number of elderly welfare centers has expanded significantly. However, the current regulations and standards for foodservice management in these centers are inadequate. To address this issue, this study aimed to develop objective and integrated performance indicators based on the Balanced Scorecard for foodservice programs in elderly welfare centers. To evaluate the validity and reliability of the performance indicators, two Delphi studies were conducted in April 2017. The Delphi survey included the evaluation of strategic goals, financial perspective, customer perspective, learning and growth perspective, and the internal process perspective. The degree of consensus among experts was assessed using Kendall's W-test. As a result of the study, the study ultimately identified 33 performance indicators from 12 strategic goals in four perspectives, which could be used as an efficient tool to evaluate, supplement, and improve foodservice in elderly welfare centers. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01468-x.
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Excessive hepatic lipid accumulation is closely linked to inflammation, insulin resistance, and metabolic syndromes. We hypothesized that a combined extract containing Schisandra chinensis (SCE) could alleviate hepatic lipid accumulation. Male Sprague-Dawley rats fed a high-sucrose diet (HSD) were randomly assigned to three groups (n = 6): normal diet (ND), HSD (60% kcal from sucrose), and HSD + SCE (HSD with 2.44% SCE). Liquid chromatography-tandem mass spectrometry revealed that SCE contains chlorogenic acid (5.514 ± 0.009 mg/g) and schisandrin (0.179 ± 0.002 mg/g) as bioactive components. SCE did not alter the body weight, fat mass, lean mass, or glucose levels. Strikingly, SCE effectively reduced the plasma triglyceride (TG) and hepatic TG levels compared to the HSD group. Adiposity reduction is due to decreased activity of hepatic de novo lipogenic enzymes. These results indicated that SCE has nutraceutical potential for the prevention and treatment of hepatic steatosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01464-1.
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Inflammatory bowel disease (IBD) pathogenesis involves complex inflammatory events and cell death. Although IBD involves mainly necrosis in the digestive tract, pyroptosis has also been recognized. Nonetheless, the underlying basis is elusive. Gα12/13 overexpression may affect endoplasmic reticulum (ER) stress. This study examined how Gα12/13 and ER stress affect pyroptosis using dextran sulfate sodium (DSS)-induced colitis models. Gα12/13 levels were increased in the distal and proximal colons of mice exposed to a single cycle of DSS, as accompanied by increases of IRE1α, ATF6, and p-PERK. Moreover, Il-6, Il-1ß, Ym1, and Arg1 mRNA levels were increased with caspase-1 and IL-1ß activation, supportive of pyroptosis. In the distal colon, RIPK1/3 levels were enhanced to a greater degree, confirming necroptosis. By contrast, the mice subjected to three cycles of DSS treatments showed decreases of Gα12/13, as accompanied by IRE1α and ATF6 suppression, but increases of RIPK1/3 and c-Cas3. AZ2 treatment, which inhibited Gα12, has an anti-pyroptotic effect against a single cycle of colitis. These results show that a single cycle of DSS-induced colitis may cause ER stress-induced pyroptosis as mediated by Gα12 overexpression in addition to necroptosis, but three cycles model induces only necroptosis, and that AZ2 may have an anti-pyroptotic effect.
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Colite , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP , Animais , Camundongos , Colite/metabolismo , Colite/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Endorribonucleases/genética , Endorribonucleases/metabolismo , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , PiroptoseRESUMO
The anti-inflammatory effect of the ethanol extract of Sargassum yezoense and its fractions were investigated in this study. The ethanol extract exhibited a strong anti-inflammatory effect on lipopolysaccharide-stimulated RAW 264.7 macrophages and effectively suppressed the M1 polarization of murine bone-marrow-derived macrophages stimulated by lipopolysaccharides and IFN-γ (interferon-gamma). Through a liquid-liquid extraction process, five fractions (n-hexane, chloroform, ethyl acetate, butanol, and aqueous) were acquired. Among these fractions, the chloroform fraction (SYCF) was found to contain the highest concentration of phenolic compounds, along with two primary meroterpenoids, sargahydroquinoic acid (SHQA) and sargachromenol (SCM), and exhibit significant antioxidant capacity. It also demonstrated a robust anti-inflammatory effect. A direct comparison was conducted to assess the relative contribution of SHQA and SCM to the anti-inflammatory properties of SYCF. The concentrations of SHQA and SCM tested were determined based on their relative abundance in SYCF. SHQA contributed to a significant portion of the anti-inflammatory property of SYCF, while SCM played a limited role. These findings not only highlight the potential of the chloroform-ethanol fractionation approach for concentrating meroterpenoids in S. yezoense but also demonstrate that SHQA and other bioactive compounds work additively or synergistically to produce the potent anti-inflammatory effect of SYCF.
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Alcenos , Benzopiranos , Benzoquinonas , Sargassum , Animais , Camundongos , Clorofórmio , Etanol , LipopolissacarídeosRESUMO
OBJECTIVES: Industry- and occupation-based carcinogen exposure matrices play a pivotal role in preventing occupational cancer. While the Korean CARcinogen EXposure (K-CAREX) has been developed in recent years to assess exposure prevalence and intensity by industry, the feasibility of constructing an occupation-based exposure matrix remains unexplored. Hence, the objective of this study is to explore the potential of combining the nationwide work environment measurement database (WEMD) and the special health examination database (SHED) to develop a comprehensive occupation-based exposure matrix. METHODS: The WEMD provides information on airborne lead measurements, including industry codes, but it does not include data related to occupations. In contrast, the SHED contains information on both occupation and blood lead levels. By integrating these 2 databases, we attempted to assess airborne lead exposure levels by occupation. Additionally, we performed a rank correlation analysis to compare the airborne exposure levels with corresponding blood lead levels according to occupation. RESULTS: A total of 35 425 workers who both wore air samplers for lead and underwent special health examinations for lead were extracted between 2019 and 2021. An occupation-based exposure matrix was developed to evaluate the intensity of lead exposure across a range of occupations, encompassing 51 minor occupations and 70-unit occupations. Rank correlation analyses showed strong positive correlations between airborne lead and blood lead measurements according to occupation. CONCLUSIONS: Our study findings suggest that combining 2 nationwide surveillance databases can be an effective approach for creating an occupation-based exposure matrix. However, our results also highlight several limitations that need to be addressed in future studies to improve the accuracy and reliability of such matrices.
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Exposição Ocupacional , Humanos , Exposição Ocupacional/análise , Chumbo/análise , Reprodutibilidade dos Testes , Ocupações , Carcinógenos/análise , República da Coreia/epidemiologiaRESUMO
Exposure to heavy metals in water and food poses a significant threat to human well-being, necessitating the efficient removal of these contaminants. The process of urban development exacerbates heavy metal pollution, thereby increasing risks to both human health and ecosystems. Heavy metals have the capacity to enter the food chain, undergo bioaccumulation and magnify, ultimately resulting in adverse effects on human health. Therefore, implementing effective pollution control measures and adopting sustainable practices are crucial for mitigating exposure and associated health risks. Various innovative approaches, including adsorption, ion exchange, and electrochemical technology, are currently being actively investigated to cope with the issue of heavy metal contamination. These innovative methods offer benefits such as efficient recycling, cost-effectiveness and environmental friendliness. In this review, we summarize recent advances for removing heavy metals from water, soil and food, providing valuable guidance for environmental engineers and researchers seeking to address contamination challenges.
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INTRODUCTION: Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent. AIMS AND METHODS: Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature. RESULTS: A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (pâ =â .002), whereas no significant increase was found in female smokers compared to female nonsmokers (pâ =â .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (pâ =â .018), whereas no significant association was found in female smokers (pâ =â .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes. CONCLUSIONS: WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies. IMPLICATIONS: Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.
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Fumar Cigarros , Poluição por Fumaça de Tabaco , Humanos , Masculino , Feminino , Proteína C-Reativa/metabolismo , Inquéritos Nutricionais , Fumar Cigarros/efeitos adversos , Cotinina/análise , Biomarcadores , Inflamação , Contagem de Leucócitos , Poluição por Fumaça de Tabaco/efeitos adversos , Poluição por Fumaça de Tabaco/análiseRESUMO
Cyclic imines (CIs) produced by microalgae species and accumulating in the food chain of marine organisms are novel biotoxins that do not belong to the classical group of marine biotoxins. In the past, CIs were found only in limited areas, but in recent years, rapid changes in marine ecosystems have led to widespread CIs, increasing exposure to toxic risks. Monitoring of CIs is therefore required, but still analytically challenging due to the presence of high levels of analogues and interference from other lipophilic substances. Herein, we developed the LC/MRM-MS-based quantitative platform that can selectively enrich for marine-derived CIs and monitor seven CIs simultaneously: pinnatoxin (PnTX E, PnTX F, PnTX G), gymnodimine (GYM A), and spirolide (13-desMe SPX C, 13,19-didesMe SPX C, 20-Me SPX G). In particular, the combination of chromatographic separation by the hydrophobic nature of intrinsic residues of CIs with monitoring of CI structure-specific product ions generated by CID-MS/MS significantly improves the selectivity and sensitivity for quantitative analysis. Indeed, three CIs corresponding to PnTX G, GYM A, and 13-desMe SPX C could be successfully determined at the level of part-per-trillion (ppt) in three species of shellfish collected around the Korean Peninsula. Our analysis revealed that the expression of CIs in the Korean Peninsula was more influenced by the season rather than the species. This analytical platform with high sensitivity can be applied not only to marine biology but also to various other fields requiring CI analysis. Key Contribution: A highly sensitive analytical method for the simultaneous quantitation of cyclic imines based on LC/MRM-MS has been developed.
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Ecossistema , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Frutos do Mar/análise , Toxinas Marinhas/análise , Iminas/análiseRESUMO
CASE: We present the case of a 47-year-old paraplegic woman who underwent resection of an intermediate-grade chondrosarcoma in the proximal ulna, which was initially reconstructed with an osteoarticular allograft. However, after more than 25 years without complications, she sustained an intra-articular fracture of the allograft, which was then successfully treated using a vascularized medial femoral condyle (MFC) flap and anterolateral thigh flap. The patient has subsequently recovered her baseline elbow function, has no pain, and can use her wheelchair without restrictions. CONCLUSION: Free MFC flaps are viable options to salvage osteoarticular allografts that are affected by intra-articular fractures.
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Fraturas Ósseas , Retalhos de Tecido Biológico , Feminino , Humanos , Pessoa de Meia-Idade , Fêmur/cirurgia , Fraturas Ósseas/cirurgia , Aloenxertos , Ulna/cirurgiaRESUMO
BACKGROUND: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. METHODS: A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994-2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987-2021 was also performed. RESULTS: A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by -6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of -12% annually. CONCLUSIONS: Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.
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Chumbo , Exposição Ocupacional , Local de Trabalho , Humanos , Povo Asiático , Bases de Dados Factuais , República da CoreiaRESUMO
SCOPE: Mild cognitive impairment is associated with a high prevalence of dementia. The study examines the benefits of a modified Korean MIND (K-MIND) diet and explores biomarkers using multi-omics analysis. METHODS AND RESULTS: The K-MIND diet, tailored to the elderly Korean population, includes perilla oil, milk, or fermented milk, and avoids alcohol consumption. As a result, the K-MIND diet significantly improves subjects "orientation to place" in the Korean version of the Mini-Mental State Examination, 2nd edition test. According to multi-omics analysis, the K-MIND diet upregulates genes associated with mitochondrial respiration, including ubiquinone oxidoreductase, cytochrome C oxidase, and ATP synthase, and immune system processes, and downregulates genes related to nuclear factor kappa B activity and inflammatory responses. In addition, K-MIND affects the metabolic pathways of glycine, serine, threonine, tryptophan, and sphingolipids, which are closely linked to cognitive function through synthesis of neurotransmitters and structures of brain cell membranes. CONCLUSION: The findings imply that the K-MIND diet improves cognitive function by upregulating key genes involved in oxidative phosphorylation and downregulating pro-inflammatory cytokines.
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Aminoácidos , Cognição , Humanos , Feminino , Idoso , Dieta , Inflamação , República da CoreiaRESUMO
This study investigated the potential applicability of wound dressing hydrogels for tissue engineering, focusing on their ability to deliver pharmacological agents and absorb exudates. Specifically, we explored the use of polyphenols, as they have shown promise as bioactive and cross-linking agents in hydrogel fabrication. Ishophloroglucin A (IPA), a polyphenol not previously utilized in tissue engineering, was incorporated as both a drug and cross-linking agent within the hydrogel. We integrated the extracted IPA, obtained through the utilization of separation and purification techniques such as high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR) into oxidized alginate (OA) and gelatin (GEL) hydrogels. Our findings revealed that the mechanical properties, thermal stability, swelling, and degradation of the multifunctional hydrogel can be modulated via intermolecular interactions between the natural polymer and IPA. Moreover, the controlled release of IPA endows the hydrogel with antioxidant and antimicrobial characteristics. Overall, the wound healing efficacy, based on intermolecular interactions and drug potency, has been substantiated through accelerated wound closure and collagen deposition in an ICR mouse full-thickness wound model. These results suggest that incorporating IPA into natural polymers as both a drug and cross-linking agent has significant implications for tissue engineering applications.
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Gelatina , Hidrogéis , Camundongos , Animais , Hidrogéis/química , Gelatina/química , Alginatos/química , Camundongos Endogâmicos ICR , Cicatrização , AntibacterianosRESUMO
Since the recognition of a significant oxygen-redox contribution to enhancing the capacity of Li transition-metal oxide cathodes, the oxygen release and subsequent structural variations together with capacity fading are critical issues to achieve better electrochemical performance. As most previous reports dealt with the structural degradation of cathodes after electrochemical cycling, it is fairly difficult to clarify how substantial the effect of lattice strain on the oxygen release will be while exclusively ruling out any electrochemical influences. By utilizing nanoindentation and mechanical surface polishing of single-crystal LiCoO2 and Li2 MnO3 , the local variations of both the atomic structure and oxygen content are scrutinized. Atomic-column-resolved imaging reveals that local LiM (M = Co and Mn) disordering and further amorphization are induced by mechanical strain. Moreover, substantial oxygen deficiency in the regions with these structural changes is directly identified by spectroscopic analyses. Ab initio density functional theory calculations also demonstrate energetically favorable formation of oxygen vacancies under shear strain. Providing direct evidence of oxygen release as a consequence of lattice strain, the findings in this work suggest that efficient strain relaxation will be of great significance for longevity of the anion framework in layered oxide cathodes.
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In this study, to obtain high performances of the dye-sensitized solar cells using the optimal TiO2 photoelectrode for the synthesized pyrazine-based organic photosensitizers, three types of TiO2 photoelectrodes were fabricated and evaluated for comparison. The double-layered nanoporous TiO2 photoelectrode (SPD type) consisted of a dispersed TiO2 layer and a transparent TiO2 layer. The single-layered nanoporous TiO2 photoelectrodes (D type and SP type) consisted of a dispersed TiO2 layer and a transparent TiO2 layer, respectively. The surface area, pore volume, and crystalline structures of the three types of TiO2 photoelectrodes were analyzed by Brunauer-Emmett-Teller method, field-emission scanning electron microscopy, and X-ray diffractometry to confirm their crystallinity and surface morphology. The structures of the three types of TiO2 photoelectrode-adsorbed organic sensitizers were investigated using X-ray photoelectron spectroscopy. The photovoltaic performances of DSSC devices using three organic photosensitizers adsorbed onto the three types of TiO2 photoelectrodes were investigated under a light intensity of 100 mW/cm2 at AM 1.5. The DSSC device using double-layered SPD type TiO2 photoelectrodes displayed 1.31â¼2.64% efficiency, compared to single-layered SP type TiO2 photoelectrodes (1.31â¼2.50%) and D type TiO2 photoelectrodes (0.90â¼1.54%), using organic photosensitizers. The DSSC device using the SPD type TiO2 photoelectrode and trifluoromethylbenzopyrazine (TPPF) as a photosensitizer showed the highest performances: J sc of 5.69 mA/cm2, V oc of 0.69 V, FF of 0.67, and efficiency of 2.64%. The relationship between photovoltaic effects and interfacial resistance characteristics of DSSCs using the three organic photosensitizers adsorbed onto the three types of TiO2 photoelectrodes could be interpreted from interfacial resistances according to frequency through impedance analysis.
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The low-frequency Raman signals of single-wall carbon nanotubes (SWNTs), appearing in the range of 100-300 cm-1, have been interpreted as radial-breathing mode (RBM) comprising pure radial Eigenvectors. Here, we report that most of the low-frequency and intermediate-frequency signals of SWNTs are radial-tangential modes (RTMs) coexisting radial and tangential Eigenvectors, while only the first peak at the low-frequency side is the RBM. Density functional theory simulation for SWNTs of ~ 2 nm in diameter shows that dozens of RTMs exhibit following the RBM (~ 150 cm-1) up to G-mode (~ 1592 cm-1) in order with Landau regulation. We specify the RBM and the RTM on Raman spectra obtained from SWNTs, where both appear as prominent peaks between 149 and 170 cm-1 and ripple-like peaks between 166 and 1440 cm-1, respectively. We report that the RTMs have been regarded as RBM (~ 300 cm-1) and ambiguously named as intermediate-frequency mode (300-1300 cm-1) without assignment. The RTMs gradually interlink the RBM and the G-mode resulting in the symmetric Raman spectra in intensity. We reveal high-resolution transmission microscope evidence for a helical structure of SWNTs, informing the typical diameter of commercial SWNTs to be 1.4-2 nm.
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Pollutant exposure due to industrial development increases oxidative stress in human bodies. Dietary intake of antioxidant shows a protective effect against oxidative damage induced by oxidative stress. Therefore, the development of natural antioxidants is needed. In this study, the antioxidant activities of some Nepali medicinal plant extracts were measured. Using Rose bengal and 3,3',5,5'-tetramethylbenzidine, a novel assay was utilized to evaluate the singlet oxygen scavenging capacity, and showed a strong correlation with other antioxidant assays. Also, antioxidant capacities based on four assays including the singlet oxygen scavenging assay were highly correlated (≥ 0.858) with the total phenolic contents in the medicinal plant extracts. Among the selected extracts, Persicaria capitata, Elaphoglossum marginatum and Eurya acuminata showed the highest antioxidant capacities. Overall, this study presents a novel approach for evaluating singlet oxygen scavenging capacity, and performed a screening of antioxidant capacities of 54 Nepali herbal medicines. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01175-z.