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As the demand for rechargeable lithium-ion batteries (LIBs) with higher energy density increases, the interest in lithium-rich oxide (LRO) with extraordinarily high capacities is surging. The capacity of LRO cathodes exceeds that of conventional layered oxides. This has been attributed to the redox contribution from both cations and anions, either sequentially or simultaneously. However, LROs with notable anion redox suffer from capacity loss and voltage decay during cycling. Therefore, a fundamental understanding of their electrochemical behaviors and related structural evolution is a prerequisite for the successful development of high-capacity LRO cathodes with anion redox activity. However, there is still controversy over their electrochemical behavior and principles of operation. In addition, complicated redox mechanisms and the lack of sufficient analytical tools render the basic study difficult. In this review, we aim to introduce theoretical insights into the anion redox mechanism andin situanalytical instruments that can be used to prove the mechanism and behavior of cathodes with anion redox activity. We summarized the anion redox phenomenon, suggested mechanisms, and discussed the history of development for anion redox in cathode materials of LIBs. Finally, we review the recent progress in identification of reaction mechanisms in LROs and validation of engineering strategies to improve cathode performance based on anion redox through various analytical tools, particularly,in situcharacterization techniques. Because unexpected phenomena may occur during cycling, it is crucial to study the kinetic properties of materialsin situunder operating conditions, especially for this newly investigated anion redox phenomenon. This review provides a comprehensive perspective on the future direction of studies on materials with anion redox activity.
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Batteries based on sodium superoxide and on potassium superoxide have recently been reported. However, there have been no reports of a battery based on lithium superoxide (LiO2), despite much research into the lithium-oxygen (Li-O2) battery because of its potential high energy density. Several studies of Li-O2 batteries have found evidence of LiO2 being formed as one component of the discharge product along with lithium peroxide (Li2O2). In addition, theoretical calculations have indicated that some forms of LiO2 may have a long lifetime. These studies also suggest that it might be possible to form LiO2 alone for use in a battery. However, solid LiO2 has been difficult to synthesize in pure form because it is thermodynamically unstable with respect to disproportionation, giving Li2O2 (refs 19, 20). Here we show that crystalline LiO2 can be stabilized in a Li-O2 battery by using a suitable graphene-based cathode. Various characterization techniques reveal no evidence for the presence of Li2O2. A novel templating growth mechanism involving the use of iridium nanoparticles on the cathode surface may be responsible for the growth of crystalline LiO2. Our results demonstrate that the LiO2 formed in the Li-O2 battery is stable enough for the battery to be repeatedly charged and discharged with a very low charge potential (about 3.2 volts). We anticipate that this discovery will lead to methods of synthesizing and stabilizing LiO2, which could open the way to high-energy-density batteries based on LiO2 as well as to other possible uses of this compound, such as oxygen storage.
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Tomato (Solanum lycopersicum) is one of the most economically important vegetables worldwide, and its production is directly affected by several bacterial diseases (Singh et al., 2017). During a disease survey in 2020, pith necrosis-like symptoms, commonly caused by Pseudomonas spp., were observed in two commercial greenhouses in PyeongChang and Gyeongju, South Korea. Disease incidence ranged from 8 to 10%, and infected plants showed wilt symptoms, brown stem discoloration, leaf blight, and corrugated pith tissues (eXtra Fig. 1). Symptomatic stem tissues were surface disinfected, cut into small pieces, and macerated in sterile water. The resulting suspension was spread on nutrient agar, and incubated at 28°C. The dominant bacterial colony types were round, mucoid, and frequently produced yellow to brown pigments. Four bacterial colonies (CPB20664 - CPB20667), each from a different diseased plant, were selected for further study. All isolates were Gram-negative and did not produce fluorescent pigments on King's B medium. Biochemical profiles of the isolates were determined by the API20NE (Biomerieux, Durhan, NC, USA) and LOPAT test (eXtra Table 1). The bacterial isolates were further identified by PCR amplification of partial 16S rRNA, gyrB, and rpoD genes using primers 27F/1492R, UP-1E/AprU, and 70F/70R, respectively (Lane 1991, Yamamoto et al., 2000). The resulting sequences were deposited in GenBank under accession numbers MW602997 to MW603000 for 16S rRNA, MW602987 to MW602990 for gyrB, and MW602991 to MW602994 for rpoD. These sequences exhibited 99-100% nucleotide similarities with multiple Pseudomonas mediterranea sequences in Genbank. Additionally, the isolates were subjected to PCR assays using the P. mediterranea specific primers PC5/1-PC5/2 and the P. corrugata specific primers PC1/1-PC1/2 (Catara et al., 2002). All isolates produced a specific 600-bp band with the P. mediterranea primers, but did not produce any bands with the P. corrugata specific primers. The PCR amplicons were sequenced and BLAST queried against GenBank database. All isolates shared 100% identity with the type strain P. mediterranea DSM 16733 (acc No. LT629790.1). These results indicated that the bacteria isolated from the tomato plants with pith necrosis were P. mediterranea. Pathogenicity tests were conducted on 2-week-old tomato seedlings (cv. Yekwang) by wound inoculations. Single colonies were picked up using sterile toothpicks, and the stems of tomato seedlings were stabbed below the second leaves. As a negative control, a sterile toothpick was dipped in sterile water and used in the same manner. After inoculation, the plants were kept in a humidity box for 48 h, then moved to a plant growth room. After 15 days, light brown lesions had developed at the stab sites, and pith necrosis and slight wilting of plants were observed at 30 days (eXtra Fig. 1). Control plants remained asymptomatic. P. mediterranea was re-isolated from infected plants, fulfilling Koch's postulates. Five species of Pseudomonas are known to cause tomato pith necrosis (Alippi and Lopez, 2010, Cañizares and García-Pedrajas., 2015, Ruan et al., 2018) including P. corrugata previously reported from Korea (Choi and Han, 2004). This is believed to be the first report of P. mediterranea as the cause of tomato pith necrosis in Korea. Tomato pith necrosis disease reduces the quality and yield of tomato production and appropriate management strategies should be investigated to control this disease.
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In September 2019, bacterial leaf spot symptoms were observed on sunflowers in an experimental field in Eumseong, South Korea. The leaves of infected plants initially showed irregular brown spots surrounded by haloes; as the disease progressed, the spots became enlarged and darkened (eXtra Fig. 1a). At the flowering stage, leaves became dry and showed signs of blight including defoliation; dark brown spots were also observed on sunflower stems and petioles but not on floral discs (eXtra Fig. 1b). Disease incidence ranged from 5% to 30% in three surveyed plots of the field. Symptomatic leaf tissue was surface-sterilized, macerated with sterile distilled water, and cultured on nutrient agar plates at 28°C for 48 h. After incubation, nine bacterial isolates, representing individually collected samples from each field, were selected for further study. All nine isolates were Gram-negative and fluorescent pigments produced under UV on King's medium B. With the LOPAT test, the isolates were levan negative, oxidase negative, positive for pectinolytic activity, arginine dihydrolase negative, and positive for tobacco hypersensitivity. Based on 16s rRNA sequences, all isolates shared 100% identity with Pseudomonas viridiflava strain KNOX209.1 (GenBank accession no. AY604847). The 16s rRNA sequences of nine isolates were deposited in GeneBank (accession nos. MT393747, MW446479 to MW446486). Based on the phylogenetic analysis of the 16s rRNA, all isolates were grouped with P. viridiflava strains isolated from globe artichoke, Chinese cabbage, and rape (Myung et al. 2010, Sanver et al. 2019, and Liu et al. 2019). The isolates CPB 19362, CPB 19366 and CPB 19372, which represent each plot were selected for further phylogenetic analysis and pathogenicity assays. The identity of these isolates was confirmed by sequences of housekeeping genes of the gyrase B subunit (gyrB) and RNA polymerase σ70 factor (rpoD) (Yamamoto et al. 2000) (GenBank accession nos. MT409400, MW446487 and MW446494 for gyrB and MT409401, MW446495 and MW446502 for rpoD). Based on the phylogenetic analyses of gyrB and rpoD, the three isolates belong to the same clade as the P. viridiflava pathotypes and were distinguished from P. syringae complex (eXtra Fig. 2). These results indicated that the bacteria isolated from the spots on the sunflower plants were P. viridiflava strains. To confirm the pathogenicity, bacterial suspensions (approximately 108 CFU/mL) of three representative isolates sprayed onto 4-week-old sunflower (cv. Common) seedlings separately until runoff occurred. Sterile distilled water was used as a control and inoculated in the same manner. After inoculation, plants were covered with transparent plastic bags at room temperature for 24 h. Plastic bags were then removed and plants were grown on a plant growth shelf at 25°C in 50% relative humidity. The leaves of plants inoculated with the bacterial suspensions developed small brown spots after 24 h. After 3 days, brown spots surrounded by chlorotic or necrotic areas were observed on infected leaves (eXtra Fig. 1c). These spots gradually increased in size and formed brown lesions with haloes similar to those of infected field-grown plants (eXtra Fig. 1d), but not on the controls treated with sterile water. The pathogenicity test was repeated three times. Isolates recovered from infected leaves showed the same morphological, biochemical, and molecular characteristics as the original isolates from field samples. To our knowledge, this is the first report of bacterial leaf spot on sunflower caused by P. viridiflava in South Korea.
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Progressive diabetic nephropathy (DN) in diabetes leads to major morbidity and mortality. The major pathological alterations of DN include mesangial expansion, extracellular matrix alterations, tubulointerstitial fibrosis, and glomerular sclerosis. Polygoni avicularis is widely used in traditional oriental medicine and has long been used as a diuretic, astringent, insecticide and antihypertensive. However, to the best of the authors' knowledge, the effects of the ethanolic extract from rhizome of Polygoni avicularis (ER-PA) on DN have not yet been assessed. The present study aimed to identify the effect of ER-PA on renal dysfunction, which has been implicated in DN in human renal mesangial cells and db/db mice and investigate its mechanism of action. The in vivo experiment was performed using Polygoni avicularis-ethanol soluble fraction (ER-PA) and was administrated to db/db mice at 10 and 50 mg/kg dose. For the in vitro experiments, the human renal mesangial cells were induced by high glucose (HG, 25 mM). The ER-PA group showed significant amelioration in oral glucose tolerance, and insulin resistance index. ER-PA significantly improved the albumin excretion and markedly reduced plasma creatinine, kidney injury molecule-1 and C-reactive protein. In addition, ER-PA significantly suppressed inflammatory cytokines. Histopathologically, ER-PA attenuated glomerular expansion and tubular fibrosis in db/db mice. Furthermore, ER-PA suppressed the expression of renal fibrosis biomarkers (TGF and Collagen IV). ER-PA also reduced the NLR family pyrin domain containing 3 inflammatory factor level. These results suggest that ER-PA has a protective effect against renal dysfunction through improved insulin resistance as well as the inhibition of nephritis and fibrosis in DN.
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Nefropatías Diabéticas/tratamiento farmacológico , Fitoterapia , Polygonum/química , Animales , Células Cultivadas , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Fibrosis , Glucosa/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/patología , Resistencia a la Insulina , Masculino , Proteínas de la Membrana/metabolismo , Células Mesangiales/efectos de los fármacos , Células Mesangiales/metabolismo , Células Mesangiales/patología , Ratones , Ratones Endogámicos C57BL , Extractos Vegetales/química , Extractos Vegetales/farmacología , Rizoma/químicaRESUMEN
In this study, a centrifugal partition chromatography (CPC) separation was applied to identify antioxidant-responsive element (ARE) induction molecules from the crude extract of Lindera strychnifolia roots. CPC was operated with a two-phase solvent system composed of n-hexane-methanol-water (10:8.5:1.5, v/v/v) in dual mode (descending to ascending), which provided a high recovery rate (>95.5%) with high resolution. Then, ARE induction activity of obtained CPC fractions was examined in ARE-transfected HepG2 cells according to the weight ratios of the obtained fractions. The fraction exhibiting ARE-inducing activity was further purified by preparative HPLC that led to isolation of two eudesmane type sesquiterpenes as active compounds. The chemical structures were elucidated as linderolide U (1) and a new sesquiterpene named as linderolide V (2) by spectroscopic data. Further bioactivity test demonstrated that compounds 1 and 2 enhanced ARE activity by 22.4-fold and 7.6-fold, respectively, at 100 µM concentration while 5 µM of sulforaphane induced ARE activity 24.8-fold compared to the control.
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Bioensayo/métodos , Lindera/química , Sesquiterpenos de Eudesmano/química , Cromatografía Liquida/métodos , Extractos Vegetales/químicaRESUMEN
OBJECTIVE: Xanthotoxin (XAT) is a linear furanocoumarin mainly extracted from the plants Ammi majus L. XAT has been reported the apoptosis of tumor cells, anti-convulsant, neuroprotective effect, antioxidative activity, and vasorelaxant effects. This study aimed to investigate the vascular protective effects and underlying molecular mechanisms of XAT. METHODS: XAT's activity was studied in rat thoracic aortas, isolated with aortic rings, and human umbilical vein endothelial cells (HUVECs). RESULTS: XAT induced endothelium-dependent vasodilation in a concentration-dependent manner in the isolated rat thoracic aortas. Removal of endothelium or pretreatment of aortic rings with L-NAME, 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one, and wortmannin significantly inhibited XAT-induced relaxation. In addition, treatment with thapsigargin, 2-aminoethyl diphenylborinate, Gd3+, and 4-aminopyridine markedly attenuated the XAT-induced vasorelaxation. XAT increased nitric oxide production and Akt- endothelial NOS (eNOS) phosphorylation in HUVECs. Moreover, XAT attenuated the expression of TNF-α-induced cell adhesion molecules such as intercellular adhesion molecule, vascular cell adhesion molecule-1, and E-selectin. However, this effect was attenuated by the eNOS inhibitors L-NAME and asymmetric dimethylarginine. CONCLUSIONS: This study suggests that XAT induces vasorelaxation through the Akt-eNOS-cGMP pathway by activating the KV channel and inhibiting the L-type Ca2+ channel. Furthermore, XAT exerts an inhibitory effect on vascular inflammation, which is correlated with the observed vascular protective effects.
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Aorta Torácica/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Metoxaleno/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Animales , Aorta Torácica/metabolismo , Canales de Calcio Tipo L/metabolismo , Moléculas de Adhesión Celular/metabolismo , Células Cultivadas , GMP Cíclico/metabolismo , Endotelio Vascular/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosforilación , Canales de Potasio con Entrada de Voltaje/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Transducción de SeñalRESUMEN
Abnormal and excessive growth of mesangial cells is important in the pathophysiologic processes of diabetes-associated interstitial fibrosis and glomerulosclerosis, leading to diabetic nephropathy, which eventually turns into end-stage renal disease. Sauchinone, a biologically-active lignan isolated from aerial parts of Saururus chinensis, has anti-inflammatory and anti-viral activities effects on various cell types. However, there are no studies reporting the effects of sauchinone on diabetic nephropathy. The present study aims to investigate the role of sauchinone in mesangial cell proliferation and fibrosis induced by angiotensin II, as well as the underlying mechanisms of these processes. Human renal mesangial cells were induced by angiotensin II (AngII, 10⯵M) in the presence or absence of sauchinone (0.1-1⯵M) and incubated for 48â¯h. In this study, we found that AngII induced mesangial cell proliferation, while treatment with sauchinone inhibited the cell proliferation in a dose-dependent manner. Pre-treatment with sauchinone induced down-regulation of cyclins/CDKs and up-regulation of CDK inhibitor, p21, and p27kip1 expression. In addition, AngII-enhanced expression of fibrosis biomarkers such as fibronectin, collagen IV, and connective tissue growth factor (CTGF), which was markedly attenuated by sauchinone. Sauchinone also decreased AngII-induced TGF-ß1 and Smad-2, Smad-3, and Smad-4 expression. This study further revealed that sauchinone ameliorated AngII-induced mesangial inflammation through disturbing activation of inflammatory factors, and NLRP3 inflammasome, which is composed of the NLRP3 protein, procaspase-1, and apoptosis-associated speck-like protein containing a CARD (ASC). Moreover, pretreatment of sauchinone inhibited NF-κB translocation and ROS production in AngII-exposed mesangial cells. These data suggest that sauchinone has a protective effect on renal proliferation, fibrosis and inflammation. Therefore, sauchinone might be a potential pharmacological agent in prevention of AngII-induced renal damage leading to diabetic nephropathy.
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Benzopiranos/farmacología , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/metabolismo , Dioxoles/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Células Mesangiales/metabolismo , Angiotensina II/efectos adversos , Angiotensina II/farmacología , Línea Celular , Nefropatías Diabéticas/patología , Fibrosis , Humanos , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/patología , Células Mesangiales/patologíaRESUMEN
A comprehensive linear gradient solvent system for centrifugal partition chromatography (CPC) was developed for the bioassay-guided isolation of natural compounds. The gradient solvent system consisted of three different ternary biphasic solvents types: n-hexane-acetonitrile-water (10:2:8, v/v), ethyl acetate-acetonitrile-water (10:2:8, v/v), and water-saturated n-butanol-acetonitrile-water (10:2:8, v/v). The lower phase of the n-hexane-acetonitrile-water (10:2:8, v/v) was used as the stationary phase, while its upper phase, as well as ethyl acetate-acetonitrile-water (10:2:8), and water-saturated n-butanol-acetonitrile-water (10:2:8, v/v) were pumped to generate a linear gradient elution, increasing the mobile phase polarity. We used the gradient CPC to identify antioxidant response elements (AREs), inducing compounds from Centipeda minima, using an ARE-luciferase assay in HepG2 cells, which led to the purification of the active molecules 3-methoxyquercetin and brevilin A. The developed CPC solvent systems allow the separation and isolation of compounds with a wide polarity range, allowing active molecule identification in the complex crude extract of natural products.
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Asteraceae/química , Cromatografía Liquida/métodos , Distribución en Contracorriente/métodos , Extractos Vegetales/análisis , Solventes/química , 1-Butanol/química , Acetatos/química , Acetonitrilos/química , Elementos de Respuesta Antioxidante/efectos de los fármacos , Bioensayo , Supervivencia Celular/efectos de los fármacos , Cromatografía Liquida/instrumentación , Distribución en Contracorriente/instrumentación , Crotonatos/aislamiento & purificación , Genes Reporteros/efectos de los fármacos , Células Hep G2 , Hexanos/química , Humanos , Luciferasas/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Quercetina/análogos & derivados , Quercetina/aislamiento & purificación , Sesquiterpenos/aislamiento & purificación , Agua/químicaRESUMEN
Cardiac hypertrophy is a major risk factor for heart failure and leads to cardiovascular morbidity and mortality. Doxorubicin (DOX) is regarded as one of the most potent anthracycline antibiotic agents; however, its clinical usage has some limitations because it has serious cardiotoxic side effects such as dilated cardiomyopathy and congestive heart failure. Betulinic acid (BA) is a pentacyclic-cyclic lupane-type triterpene that has been reported to have anti-bacterial, anti-inflammatory, anti-vascular neogenesis, and anti-fibrotic effects. However, there is no study about its direct effect on DOX induced cardiac hypertrophy and apoptosis. The present study aims to investigate the effect of BA on DOX-induced cardiomyocyte hypertrophy and apoptosis in vitro in H9c2 cells. The H9c2 cells were stimulated with DOX (1 µM) in the presence or absence of BA (0.1-1 µM) and incubated for 24 h. The results of the present study indicated that DOX induces the increase cell surface area and the upregulation of hypertrophy markers including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), beta-myosin heavy chain (ß-MHC), and Myosin Light Chain-2 (MLC2) in H9c2 cells. However, the pathological hypertrophic responses were downregulated after BA treatment. Moreover, phosphorylation of JNK, ERK, and p38 in DOX treated H9c2 cells was blocked by BA. As a result of measuring the change in ROS generation using DCF-DA, BA significantly inhibited DOX-induced the production of intracellular reactive oxygen species (ROS) when BA was treated at a concentration of over 0.1 µM. DOX-induced activation of GATA-4 and calcineurin/NFAT-3 signaling pathway were remarkably improved by pre-treating of BA to H9c2 cells. In addition, BA treatment significantly reduced DOX-induced cell apoptosis and protein expression levels of Bax and cleaved caspase-3/-9, while the expression of Bcl-2 was increased by BA. Therefore, BA can be a potential treatment for cardiomyocyte hypertrophy and apoptosis that lead to sudden heart failure.
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Calcineurina/metabolismo , Cardiomegalia/etiología , Cardiomegalia/metabolismo , Cardiotónicos/farmacología , Factor de Transcripción GATA4/metabolismo , Factores de Transcripción NFATC/metabolismo , Triterpenos Pentacíclicos/farmacología , Transducción de Señal/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Cardiomegalia/patología , Cardiomegalia/prevención & control , Cardiotónicos/uso terapéutico , Línea Celular , Doxorrubicina/efectos adversos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Triterpenos Pentacíclicos/uso terapéutico , Ratas , Especies Reactivas de Oxígeno/metabolismo , Ácido BetulínicoRESUMEN
Lithium-oxygen (Li-O2) batteries are a promising class of rechargeable Li batteries with a potentially very high achievable energy density. One of the major challenges for Li-O2 batteries is the high charge overpotential, which results in a low energy efficiency. In this work size-selected subnanometer Ir clusters are used to investigate cathode materials that can help control lithium superoxide formation during discharge, which has good electronic conductivity needed for low charge potentials. It is found that Ir particles can lead to lithium superoxide formation as the discharge product with Ir particle sizes of â¼1.5 nm giving the lowest charge potentials. During discharge these 1.5 nm Ir nanoparticles surprisingly evolve to larger ones while incorporating Li to form core-shell structures with Ir3Li shells, which probably act as templates for growth of lithium superoxide during discharge. Various characterization techniques including DEMS, Raman, titration, and HRTEM are used to characterize the LiO2 discharge product and the evolution of the Ir nanoparticles. Density functional calculations are used to provide insight into the mechanism for formation of the core-shell Ir3Li particles. The in situ formed Ir3Li core-shell nanoparticles discovered here provide a new direction for active cathode materials that can reduce charge overpotentials in Li-O2 batteries.
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In the present study, the change in secretion of atrial natriuretic peptide (ANP) from the atria was defined in hypertension accompanied by ventricular hypertrophy and increased synthesis of ANP. To identify the change of the secretion and mechanisms involved, experiments were performed in isolated perfused beating atria from sham-operated normotensive and renovascular hypertensive rats. Expression of ANP, natriuretic peptide receptor (NPR)-C, components of the renin-angiotensin system, and muscarinic signaling pathway was measured in cardiac tissues. Basal levels of ANP secretion and acetylcholine (ACh)- and stretch-induced activation of ANP secretion were suppressed in the atria from hypertensive compared with normotensive rats. ACh increased ANP secretion via M2 muscarinic ACh receptor-ACh-sensitive K+ channel signaling. In hypertensive rats, ANP concentration increased in the left ventricle but decreased in the right ventricle. The atrial concentration of ANP was not changed in hypertensive compared with normotensive rats. ANP mRNA expression was accentuated in the left ventricle but suppressed in the other cardiac chambers in the hearts of hypertensive rats. NPR-C expression was inversely related to ANP mRNA levels. Angiotensin II type 1 receptor (AT1R) expression was accentuated in the cardiac chambers from hypertensive rats compared with normotensive rats, whereas angiotensin II type 2 receptor, M2 muscarinic receptor, and Kir3.4 channels were suppressed. AT1R blockade with losartan reversed the change observed in hypertensive rats. The present findings indicate that renovascular hypertension shifts the major site of ANP secretion and synthesis from the atria to the left ventricle through modulation of the expression of ANP, NPR-C, AT1R, and the M2 muscarinic signaling pathway. NEW & NOTEWORTHY Renovascular hypertension suppresses the atrial secretion of ANP and shifts the major site of the regulation of ANP secretion and synthesis from atria to the hypertrophied left ventricle possibly via modulation of the expression of ANP, natriuretic peptide receptor-C, angiotensin II subtype 1 receptor, and M2 muscarinic signaling pathway.
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Factor Natriurético Atrial/metabolismo , Atrios Cardíacos/metabolismo , Ventrículos Cardíacos/metabolismo , Hipertensión Renovascular/metabolismo , Animales , Factor Natriurético Atrial/genética , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Receptores de Angiotensina/genética , Receptores de Angiotensina/metabolismo , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismoRESUMEN
Increasing demand for flexible devices in various applications, such as smart watches, healthcare, and military applications, requires the development of flexible energy-storage devices, such as lithium-ion batteries (LIBs) with high flexibility and capacity. However, it is difficult to ensure high capacity and high flexibility simultaneously through conventional electrode preparation processes. Herein, smart conductive textiles are employed as current collectors for flexible LIBs owing to their inherent flexibility, fibrous network, rough surface for better adhesion, and electrical conductivity. Conductivity and flexibility are further enhanced by nanosizing lithium titanate oxide (LTO) and lithium iron phosphate (LFP) active materials, and hybridizing them with a flexible 2D graphene template. The resulting LTO/LFP full cells demonstrate high areal capacity and flexibility with tolerance to mechanical fatigue. The battery achieves a capacity of 1.2 mA h cm-2 while showing excellent flexibility. The cells demonstrate stable open circuit voltage retention under repeated flexing for 1000 times at a bending radius of 10 mm. The discharge capacity of the unflexed battery is retained in cells subjected to bending for 100 times at bending radii of 30, 20, and 10 mm, respectively, confirming that the suggested electrode configuration successfully prevents structural damage (delamination or cracking) upon repeated deformation.
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As soluble catalysts, redox-mediators (RMs) endow mobility to catalysts for unconstrained access to tethered solid discharge products, lowering the energy barrier for Li2 O2 formation/decomposition; however, this desired mobility is accompanied by the undesirable side effect of RM migration to the Li metal anode. The reaction between RMs and Li metal degrades both the Li metal and the RMs, leading to cell deterioration within a few cycles. To extend the cycle life of redox-mediated Li-O2 batteries, herein graphene oxide (GO) membranes are reported as RM-blocking separators. It is revealed that the size of GO nanochannels is narrow enough to reject 5,10-dihydro-5,10-dimethylphenazine (DMPZ) while selectively allowing the transport of smaller Li+ ions. The negative surface charges of GO further repel negative ions via Donnan exclusion, greatly improving the lithium ion transference number. The Li-O2 cells with GO membranes efficiently harness the redox-mediation activity of DMPZ for improved performance, achieving energy efficiency of above 80% for more than 25 cycles, and 90% for 78 cycles when the capacity limits were 0.75 and 0.5 mAh cm-2 , respectively. Considering the facile preparation of GO membranes, RM-sieving GO membranes can be cost-effective and processable functional separators in Li-O2 batteries.
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BACKGROUND: Use of dietary supplements among cancer survivors is common and controversial, but information on the amount of nutrients from supplements among cancer survivors is limited. We examined the amount of nutrients and their contribution to total nutrient intake from supplements and compared these data between cancer survivors and cancer-free individuals. We also identified factors associated with supplement use among cancer survivors. METHODS: We identified 400 cancer survivors and 10,387 cancer-free individuals, aged ≥ 19 years, from the fifth Korea National Health and Nutrition Examination Survey (KNHANES) V-1, 2 (2010, 2011). We calculated the amount of nutrients consumed from foods and supplements, the percent contributions of supplement nutrients to total nutrient intakes and cancer survivors' nutrient intakes relative to the Estimated Average Requirements (EARs) and the Tolerable Upper Intake Levels (ULs). We examined factors associated with supplement use among cancer survivors. RESULTS: We found that 33.3% of cancer survivors and 22.1% of cancer-free individuals reported the use of dietary supplements. Compared to cancer-free individuals, cancer survivors had higher intakes of riboflavin, folate, and iron from foods (p < 0.05 for each), and higher intakes of calcium (p = 0.05) and vitamin C (p = 0.01) from foods and supplements. The similar pattern was observed for the percent contributions to total nutrient intake. Cancer survivors had higher proportion of participants below EARs than cancer-free individuals for thiamin and niacin (p < 0.05 for each). The proportions of cancer survivors below the EARs were 61.2% for calcium, 49.1% for riboflavin, and 43.5% for folate and the proportions of cancer survivors above the ULs were 3.3% for iron, and 2.3% for vitamin A. For female cancer survivors, education above an elementary school level, moderate physical activity, low vegetable intake, and high circulating vitamin D levels were associated with supplement use. For male cancer survivors, living in an urban area, no consumption of alcohol, and lower energy intake, were associated with supplement use. CONCLUSIONS: Korean cancer survivors have higher rate of dietary supplement use and higher contribution from supplements to total nutrient intake than cancer-free individuals. Demographic and lifestyle factors were associated with supplement use among cancer survivors.
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Supervivientes de Cáncer/psicología , Encuestas sobre Dietas , Suplementos Dietéticos/estadística & datos numéricos , Neoplasias/prevención & control , Encuestas Nutricionales , Adulto , Anciano , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/psicología , Pronóstico , República de Corea/epidemiología , Tasa de Supervivencia , Adulto JovenRESUMEN
BACKGROUND: Metabolic syndrome such as dyslipidemia, hypertension, obesity, impaired glucose tolerance and fatty liver, can be caused by modification of diet by means of overconsumption of high fructose diet. This study was designed to investigate whether combination with Red ginseng and Polygoni Multiflori Radix (RGPM), widely used traditional herbal medicine, ameliorates on highfructose (HF) diet-induced metabolic syndrome. METHODS: SD rats were fed the 60% HF diet with/without rosiglitazone, and RGPM 100, 300 mg/kg/day, respectively. All groups received regular diet or HF diet, respectively, for 8 weeks. The last three groups treatment of rosiglitazone and RPGM orally for a period of 6 weeks. RESULTS: Chronic treatment with RGPM significantly decreased body weight, fat weight and adipocyte size. RGPM significantly prevented the development of the metabolic disturbances such as hypertension, hyperlipidemia and impaired glucose tolerance. RGPM also led to increase in high density lipoprotein level in the HF group. RGPM suppressed high-fructose diet induced vascular inflammation marker expression such as adhesion molecules and ET-1 in aorta as well as increasing of C-reactive protein (CRP) levels in plasma. Similarly, RGPM attenuated hepatic lipid accumulation by inhibition of monocyte chemoattractant protein-1 (MCP-1) expression. CONCLUSION: An administration of RGPM may be a beneficial therapy for the treatment of metabolic syndrome through the improvement of hypertension, obesity, hyperlipidemia, vascular inflammation and insulin resistance.
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Medicamentos Herbarios Chinos/uso terapéutico , Fructosa/administración & dosificación , Síndrome Metabólico/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Panax , Fitoterapia , Polygonum , Tejido Adiposo/metabolismo , Animales , Glucemia/metabolismo , Presión Sanguínea , Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Proteína C-Reactiva/metabolismo , Quimiocina CCL2/sangre , Dieta/efectos adversos , Quimioterapia Combinada , Medicamentos Herbarios Chinos/farmacología , Fructosa/efectos adversos , Mediadores de Inflamación/metabolismo , Lipoproteínas HDL/sangre , Masculino , Síndrome Metabólico/etiología , Síndrome Metabólico/metabolismo , Obesidad/complicaciones , Obesidad/metabolismo , Ratas Sprague-DawleyRESUMEN
The potential risks that electromagnetic fields (EMF) pose to human physiology have been debated for several decades, especially considering that EMF is almost omnipresent and some occupations involve regular exposure to particularly strong fields. In the present study, the effects of 60 Hz 0.3 mT EMF on CD4+ T cells were evaluated. Production of T cell related cytokines, IFN-γ and IL-2, was not altered in CD4+ T cells that were exposed to EMF, and cell proliferation was also unaffected. The expression of genes present in a subset of Th17 cells was upregulated following EMF exposure, and the production of effector cytokines of the IL-17A subset also increased. To determine signaling pathways that underlie these effects, phosphorylation of STAT3 and SMAD3, downstream molecules of cytokines critical for Th17 induction, was analyzed. Increased SMAD3 phosphorylation level in cells exposed to EMF, suggesting that SMAD3 may be at least in part causing the increased Th17 cell production. Differentiation of Treg, another CD4+ T cell subset induced by SMAD3 signaling, was also elevated following EMF exposure. These results suggest that 60 Hz 0.3 mT EMF exposure amplifies TGF-ß signaling and increases the generation of specific T cell subsets.
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Diferenciación Celular/fisiología , Campos Electromagnéticos , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/fisiología , Células Th17/citología , Células Th17/fisiología , Animales , Diferenciación Celular/efectos de la radiación , Células Cultivadas , Citocinas/metabolismo , Relación Dosis-Respuesta en la Radiación , Masculino , Ratones , Ratones Endogámicos C57BL , Dosis de Radiación , Exposición a la Radiación , Linfocitos T Reguladores/efectos de la radiación , Células Th17/efectos de la radiaciónRESUMEN
Among many challenges present in Li-air batteries, one of the main reasons of low efficiency is the high charge overpotential due to the slow oxygen evolution reaction (OER). Here, we present systematic evaluation of Pt, Pd, and Ru nanoparticles supported on rGO as OER electrocatalysts in Li-air cell cathodes with LiCF3SO3-tetra(ethylene glycol) dimethyl ether (TEGDME) salt-electrolyte system. All of the noble metals explored could lower the charge overpotentials, and among them, Ru-rGO hybrids exhibited the most stable cycling performance and the lowest charge overpotentials. Role of Ru nanoparticles in boosting oxidation kinetics of the discharge products were investigated. Apparent behavior of Ru nanoparticles was different from the conventional electrocatalysts that lower activation barrier through electron transfer, because the major contribution of Ru nanoparticles in lowering charge overpotential is to control the nature of the discharge products. Ru nanoparticles facilitated thin film-like or nanoparticulate Li2O2 formation during oxygen reduction reaction (ORR), which decomposes at lower potentials during charge, although the conventional role as electrocatalysts during OER cannot be ruled out. Pt-and Pd-rGO hybrids showed fluctuating potential profiles during the cycling. Although Pt- and Pd-rGO decomposed the electrolyte after electrochemical cycling, no electrolyte instability was observed with Ru-rGO hybrids. This study provides the possibility of screening selective electrocatalysts for Li-air cells while maintaining electrolyte stability.
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Core-shell carbon-coated LiFePO4 nanoparticles were hybridized with reduced graphene (rGO) for high-power lithium-ion battery cathodes. Spontaneous aggregation of hydrophobic graphene in aqueous solutions during the formation of composite materials was precluded by employing hydrophilic graphene oxide (GO) as starting templates. The fabrication of true nanoscale carbon-coated LiFePO4 -rGO (LFP/C-rGO) hybrids were ascribed to three factors: 1)â In-situ polymerization of polypyrrole for constrained nanoparticle synthesis of LiFePO4 , 2)â enhanced dispersion of conducting 2D networks endowed by colloidal stability of GO, and 3)â intimate contact between active materials and rGO. The importance of conducting template dispersion was demonstrated by contrasting LFP/C-rGO hybrids with LFP/C-rGO composites in which agglomerated rGO solution was used as the starting templates. The fabricated hybrid cathodes showed superior rate capability and cyclability with rates from 0.1 to 60â C. This study demonstrated the synergistic combination of nanosizing with efficient conducting templates to afford facile Li(+) ion and electron transport for high power applications.
RESUMEN
BACKGROUND: The pathological change of kidney in diabetic nephropathy is represented hypertrophy, inflammation, and renal fibrosis. Oryeongsan, traditional oriental herbal formula, is widely used for the treatment of nephrosis, dropsy, and uremia. This study was examined whether Oryeongsan attenuate high-glucose (HG)-promoted rat mesangial cell fibrosis and matrix accumulation, major features of diabetic glomerulosclerosis. METHODS: Oryeongsan was mixed traditional herbal medicine, Alisma orientale Juz, Polyporus umbellatus Fries, Atractylodes macrocephala Koidez, Poria cocos Wolf and Cinnamomum Cassia Presl (5:3:3:1). Renoprotective role in diabetic nephropathy of Oryeongsan was evaluated by [(3)H]-thymidine incorporation, Western blot, RT-qPCR and immunofluorescence microscopy assay. RESULTS: Rat mesangial cell proliferation induced by HG was significantly accelerated, which was inhibited by Oryeongsan in a dose dependent manner. HG enhanced expression of fibrosis biomarkers such as collagen IV and connective tissue growth factor (CTGF), which was markedly attenuated by Oryeongsan. Oryeongsan increased HG-inhibited membrane type-1 matrix metalloproteinase expression (MT1-MMP) and MMP-2 promotor activity, whereas suppressed HG-induced tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression. Moreover, Oryeongsan promoted extracellular matrix degradation through disturbing transforming growth factor ß (TGF-ß)-Smad signaling. This study further revealed that Oryeongsan ameliorated HG-induced mesangial inflammation accompanying induction of intracellular cell adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1). Moreover, pretreatment of Oryeongsan inhibited NF-κB translocation in HG-exposed mesangial cell. CONCLUSION: These results demonstrate that Oryeongsan has protective effect against renal proliferation, fibrosis, and inflammation. Therefore Oryeongsan may be specific therapies targeting renal dysfunction leading to diabetic nephropathy.