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The rational manipulation of the surface reconstruction of catalysts is a key factor in achieving highly efficient water oxidation, but it is a challenge due to the complex reaction conditions. Herein, we introduce a novel in situ reconstruction strategy under a gradient magnetic field to form highly catalytically active species on the surface of ferromagnetic/non-magnetic CoFe2O4@CoBDC core-shell structure for electrochemical oxygen evolution reaction (OER). We demonstrate that the Kelvin force from the cores' local gradient magnetic field modulates the shells' surface reconstruction, leading to a higher proportion of Co2+ as active sites. These Co sites with optimized electronic configuration exhibit more favorable adsorption energy for oxygen-containing intermediates and lower the activation energy of the overall catalytic reaction. As a result, a significant enhancement in OER performance is achieved with a large current density increment about 128% at 1.63 V and an overpotential reduction by 28 mV at 10 mA cm-2 after reconstruction. Interestingly, after removing the external magnetic field, the activity could persist for over 100 h. This work showcases the directional surface reconstruction of catalysts under a gradient magnetic field for enhanced water oxidation.
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It is indispensable to develop and design high capacity, high rate performance, long cycling life, and low-cost electrodes materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, MoO2 /MoS2 /C, with dual heterogeneous interfaces, is designed to induce a built-in electric field, which has been proved by experiments and theoretical calculation can accelerate electrochemical reaction kinetics and generate interfacial interactions to strengthen structural stability. The carbon foam serves as a conductive frame to assist the movement of electrons/ions, as well as forms heterogeneous interfaces with MoO2 /MoS2 through CS and CO bonds, maintaining structural integrity and enhancing electronic transport. Thanks to these unique characteristics, the MoO2 /MoS2 /C renders a significantly enhanced electrochemical performance (324 mAh g-1 at 1 A g-1 after 1000 cycles for SIB and 500 mAh g-1 at 1 A g-1 after 500 cycles for LIBs). The current work presents a simple, useful and cost-effective route to design high-quality electrodes via interfacial engineering.
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The COVID-19 pandemic has exposed institutional deficiencies in world health development. This viewpoint paper examines the allegations about the partiality and political bias of the World Health Organization's (WHO) response to world health emergencies. We draw on quantitative and qualitative analysis of the WHO's Director-General's speeches pertaining to the COVID-19 and EVD outbreaks. We find that the WHO's discourse on COVID-19 praised the Chinese government's role in the containment. By contrast, the WHO's discourse on the African countries fighting to contain Ebola centered on the unpreparedness of these countries. We argue that the WHO's unbalanced emphasis on different practices and "traits" of member states paints a partial picture of global health emergencies, thus it fails to uphold its founding principles of egalitarianism and impartiality. Finally, we put forward suggestions about a more equal and fairer model of world health development.
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To ensure sustainable hydrogen production by water electrolysis, robust, earth-abundant, and high-efficient electrocatalysts are required. Constructing a hybrid system could lead to further improvement in electrocatalytic activity. Interface engineering in composite catalysts is thus critical to determine the performance, and the phase-junction interface should improve the catalytic activity. Here, we show that nickel diphosphide phase junction (c-NiP2 /m-NiP2 ) is an effective electrocatalyst for hydrogen production in alkaline media. The overpotential (at 10â mA cm-2 ) for NiP2 -650 (c/m) in alkaline media could be significantly reduced by 26 % and 96 % compared with c-NiP2 and m-NiP2 , respectively. The enhancement of catalytic activity should be attributed to the strong water dissociation ability and the rearrangement of electrons around the phase junction, which markedly improved the Volmer step and benefited the reduction process of adsorbed protons.
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Research on race and ethnicity has focused on conditions under which solidarity will be developed to consolidate collective benefits. For example, facing racial discrimination can bring large-scale affiliations (e.g., people of color, Latinos, or Asians) to fight against racial injustice. Focusing on the negotiation and struggle between ethnicity and nationalism among Taiwanese migrants in Australia-a politicizing context associated with a prior definition of Chinese category, despite inherent differences within it, this article shows the complexity of ethnicity when ethnic identity/solidarity intersects with nationalism and racial discrimination. I argue that Taiwanese migrants attach specific meanings to the ethnic (Chinese) category and constantly connect to and shift its boundaries in different contexts. Meanwhile, they also make a distinction between racial discrimination from white Australians and political hostility from PRC-Chinese. This article proposes a procedural and contextual understanding of ethnic identity, solidarity, nationalism, and boundary making/unmaking within the Chinese category as it is enacted in Taiwanese migrants' everyday lives. It also examines situational variability in the salience of ethnic identifications, racialization of the ethnic category, and people's interpretation of ethnic and national identity when facing racial discrimination.
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Povo Asiático/psicologia , Emigrantes e Imigrantes/psicologia , Racismo/psicologia , Identificação Social , Adulto , Austrália , Feminino , Hostilidade , Humanos , Entrevistas como Assunto , Masculino , Taiwan/etnologia , Migrantes/psicologia , Adulto JovemRESUMO
OBJECTIVE: To determine the effects of electroacupuncture (EA) and intracerebral injection of vascular endothelial growth factor (VEGF) on caspase12, caspase3, and glucose regulated protein 78 kD (GRP78) genes of rats with cerebral ischemia reperfusion injury. METHODS: 60 SD rats were randomly divided into sham-operation group, model group, EA group and EA+VEGF group with 15 rats in each group. Middle cerebral artery occlusion (MCAO) method was used to establish the model of cerebral ischemia reperfusion injury. Electro-acupuncture intervention was introduced 1 day after the injury in the EA group and EA+VEGF group: 30 minutes each session and once a day for a total of 14 d [acupoint selection: Baihui (GV 20), Quchi(Li 11), Zusanli (ST36)]. The rats in the EA+VEGF group were also injected with 10 µL of VEGF165 (0.025 µg/µL) into the lateral ventricle after the first session of EA. Five rats in each group were sacrificed after obtaining a neurological function score (mNSS) at day 0 (1 d after modeling, before EA intervention), day 7 and day 14, respectively. Nissl staining was used to observe the histomorphology of cerebral infarction areas. Immunohistochemistry was used to CM(155mm]detect GRP78 activity in the ischemic brain tissues. Real-time fluorescence quantitative PCR (real-time PCR) was used to detect the expressions of caspase12, caspase3 and GRP78 mRNA in the ischemic brain tissues. RESULTS: Compared with the sham-operation group, rats in the model group had higher mNSS scores ( P<0.05), showed signs of cerebral infarction (with reduced numbers of and disordered Nissl bodies and unclear structure), increased GRP78 immunopositive cells, increased expression of GRP78 mRNA ( P<0.05), and increased expressions of caspase12 and caspase3 mRNA ( P<0.05). Compared with the model group, EA and EA+VEGF decreased mNSS scores at day 7 and 14 ( P<0.05), showing alleviated signs of cerebral infarction, increased GRP78 immunopositive cells ( P<0.05), increased GRP78 mRNA expression ( P<0.05), and decreased caspase12 and caspase3 mRNA expressions ( P<0.05). The most obvious changes were found in the EA+VEGF group ( P<0.05). No significant changes were observed in the sham-operation group over time ( P<0.05). In comparison, mNSS scores, the signs of cerebral infarction, and the expressions of caspase12 and caspase3 decreased over time in the other groups ( P<0.05), accompanied with increased GRP78 immunopositive cells and the expression of GRP78 gene ( P<0.05). CONCLUSION: Electroacupuncture and intracerebral injection of VEGF promote tissue repair of rats with cerebral ischemic injury, possibly through down-regulating the expressions of caspase12 and caspase3 genes and up-regulating the expression of GRP78 gene. The effect of electroacupuncture in combination with intracerebral injection of VEGF is superior to that of the single use of electroacupuncture.
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Isquemia Encefálica , Eletroacupuntura , Traumatismo por Reperfusão , Animais , Caspase 12 , Caspase 3 , Proteínas de Choque Térmico , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio VascularRESUMO
A large lateral photovoltaic (LPV) effect with good linearity and fast response time is necessary for developing high-performance position-sensitive detectors (PSD). In this paper, we investigated the influence of the resistance of Sb2Se3 film and the Si on the LPV properties of the Sb2Se3/p-Si junctions. The LPV exhibits a linear dependence on the laser spot position, with a maximum position sensitivity as high as 448 mV/mm. The optical relaxation time of the LPV was about 4.98 µs, which was due to the formation of the inversion layer at the Sb2Se3/p-Si interface. Our results revealed that the high resistivity of Sb2Se3 film facilitate the LPV and confirmed the resistivity of Si substrate play a key role in the LPV properties. The giant position sensitivity and fast relaxation times of the LPV suggest that the Sb2Se3/p-Si junction is a promising candidate for a wide range of optoelectronic device applications.
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To safely and reliably use aluminum nitride (AlN) helices in the fabrication of novel micro/nanodevices, it is very important to know their mechanical properties. Herein, we investigate the mechanical properties of individual AlN helices using an in situ tensile-bending test. Tensile tests reveal that an AlN helix has an average ε of â¼4.7 ± 0.8% elastic deformation before a typical brittle fracture occurs. The bending test shows a two-step mechanical feature-linear-elastic followed by an elastic-plastic process-with an average ε bent of â¼54.5 ± 0.6%. Our results provide direct cognition about the mechanical properties of AlN helices and their benefit to the design of AlN-based flexible micro/nanodevices.
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Enhancing the reaction selectivity for multicarbon products (C2+) is an important goal for the electrochemical CO(2) reduction (ECO(2)R) process. Cuprous compounds have demonstrated promising C2+ selectivity in the ECO(2)R process, but further investigation is necessary to thoroughly elucidate their catalytic behavior toward C2+ oxygenate production. In this study, copper nitride-based materials with varying reduction rates were employed as precatalysts. Consequently, a relationship between the selectivity toward C2+ oxygenates and the Cu oxidation state during the ECOR process is established. Results of theoretical and experimental analyses reveal that the Cu0/Cu+ interface plays a key role in enhancing *CO adsorption while lowering the formation energy of *CH2CO, thereby promoting acetate production. This work highlights the significance of the Cu0/Cu+ interface in the regulation of C2+ oxygenate production and paves the way for the development of highly selective catalysts in the future.
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Focusing on health professionals' tweets regarding COVID-19, this study examines whether and how those tweets are unique based on their identity as health experts. The data revealed that the infusion of health communication with political opinions, whether pro- or against certain political parties or health policies, reflects values and may deviate from the original purpose of health communication. In addition, sentiment analysis countered the intuitive thought that health experts merely fulfill their role as neutral encyclopedias without excessively carrying sentiment. We conclude by reflecting on the meaning of health communication in relation to the political stances of professionals.
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COVID-19 , Comunicação em Saúde , Mídias Sociais , Humanos , Pandemias , Pessoal de SaúdeRESUMO
Electrochemical conversion of carbon dioxide and carbon monoxide into value-added multi-carbon products (C2+) offers a promising approach for artificial oxycarbide recycling. However, C2+ productivity is still limited by gas accessibility inside the catalyst layer. Here, a Cu-PMMA porous hybrid architecture with rich triple-phase boundaries was demonstrated to enhance both gas diffusion and electron transfer, and then, facilitate the kinetics of CO electrolysis. As a result, a high C2+ faradaic efficiency (FE) of 81.6% at a current density of 50 mA cm-2 and a maximum C2+ partial current density of 140 mA cm-2 were achieved, among the best performances for Cu/hybrid catalysts. This study provides a novel strategy for designing electrochemical CO reduction (ECORR) catalysts and paves the way for further developing gas-involving electrocatalysis.
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OBJECTIVE: To observe the effect of mild moxibustion on monocyte chemotaxis protein 1 (MCP-1)/matrix metalloproteinase 2 (MMP-2)/transforming growth factor ß1 (TGF-ß1) pro-inflammatory signal loop in senile rats, so as to explore its mechanisms underlying improving vascular aging (VA). METHODS: Twenty-four male VA SD rats were randomized into senium (VA) control, medication and moxibustion groups, and other 8 young SD rats (aged 2 months) were used as the young control group. The VA model was established by intraperitoneal injection of D-galactose (300 mg·kg-1·d-1) once daily for 4 weeks, and verified by serum total testosterone (TT) and free testosterone (FT) levels. For rats of the moxibustion group, mild moxibustion was applied to bilateral "Shenshu"(BL23) and "Guanyuan"(CV4) for 20 min, once a day, 5 days a week for 8 weeks. Rats of the medication group were treated by intraperitoneal injection of testosterone propionate (7 mg·kg-1·[3 d]-1) once daily for 8 weeks except weekends, and rats of the senium control and young control groups treated by intraperitoneal injection of the same dose of normal saline, once daily for 8 weeks except weekends. The duration of exhausted swimming (DES) before and after the treatment was recorded. H.E. staining and Masson staining were used to observe histopathological changes and collagen fiber content of the thoracic aortic tissue, respectively. The contents of serum TT, FT and angiotensin 2 (Ang â ¡) were determined by ELISA. The immunoactivity of aortic MCP-1 was detected by immunohistochemistry, and the expression levels of aortic MCP-1, MMP-2 and TGF-ß1 were detected by Western blot. RESULTS: Compared with the young control group, the levels of DES, serum TT and FT contents were significantly decreased (P<0.01), while those of serum Angâ ¡ and collagen fiber contents, aortic MCP-1 immunoactivity and MMP-2, TGF-ß1 and MCP-1 protein expression considerably increased in the senium control group (P<0.01). After the interventions, the decreased levels of DES, serum TT and FT contents and the increased levels of serum Angâ ¡, collagen fiber contents, aortic MCP-1 immunoactivity and MMP-2, TGF-ß1 and MCP-1 protein expression were reversed in both medication and moxibustion groups (P<0.01, P<0.05). The therapeutic effect of mild moxibustion was significantly superior to that of medication in down-regulating the aortic collagen fiber, serum Angâ ¡ contents and MCP-1 immunoactivity and protein expression (P<0.05). H.E. staining showed thickened endometrium and disordered arrangement of vascular smooth muscles of the aorta in the senium group, and thinner endometrium and regular and ordered arrangement of aortic vascular smooth muscles in both moxibustion and medication groups. CONCLUSION: Mild moxibustion may improve vascular aging in senescence rats, which is possibly by suppressing vascular MCP-1/MMP-2/TGF-ß1 pro-inflammatory signal loop.
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Moxibustão , Envelhecimento , Animais , Colágeno , Feminino , Masculino , Metaloproteinase 2 da Matriz/genética , Ratos , Ratos Sprague-Dawley , Testosterona , Fator de Crescimento Transformador beta1/genéticaRESUMO
BACKGROUND: Hydrogen sulfide (H(2)S) is considered as the third gasotransmitter after nitric oxide and carbon monoxide. This gas molecule participates in the regulation of renal function. Diabetic nephropathy (DN) is one of the major chronic complications of diabetes. The present study aimed to explore the changes in H(2)S metabolism in the early stage of DN and the effects of H(2)S on cultured rat renal glomerular mesangial cells (MCs). METHODS: Cultured rat MCs and streptozotocin (STZ)-induced diabetic rats were used in this study. Expression levels of cystathionine γ-lyase (CSE), transforming growth factor-ß1 (TGF-ß1) and collagen IV in rat renal cortex and in cultured MCs were determined by quantitative real-time PCR and western blot. Reactive oxygen species (ROS) released from rat MCs was assessed by fluorescent probe assays. MCs proliferation was analyzed by 5'-bromo-2'-deoxyuridine incorporation assay. RESULTS: H(2)S levels in the plasma and renal cortex and the levels of CSE messenger RNA (mRNA) and protein in renal cortex were significantly reduced, while the levels of TGF-ß1 and collagen IV increased 3 weeks after STZ injection. Administration of NaHS, a H(2)S donor, reversed the increases in TGF-ß1 and collagen IV in diabetic rats. By contrast, NaHS did not alter the TGF-ß1 and collagen IV levels in non-diabetic rats. But NaHS lowered the CSE mRNA level in renal cortex. Exposure to high glucose promoted ROS generation and cell proliferation, up-regulated the expression of TGF-ß1 and collagen IV but decreased the CSE expression in cultured MCs. Treatment of cultured MCs with NaHS reversed the effect of high glucose. NaHS did not change ROS generation, cell proliferation, TGF-ß1 and collagen IV expression in the cells cultured with normal glucose. Reduction of endogenous H(2)S generation by DL-propargylglycine, a CSE inhibitor, produced similar cellular effects as high glucose, including increases in cell proliferation, TGF-ß1 and collagen IV expressions and ROS generation. CONCLUSION: Suppressed CSE-catalyzed endogenous H(2)S production in the kidney by hyperglycemia may play an important role in the pathogenesis of DN.
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Proliferação de Células/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Mesângio Glomerular/citologia , Mesângio Glomerular/efeitos dos fármacos , Glucose/farmacologia , Sulfeto de Hidrogênio/farmacologia , Animais , Western Blotting , Células Cultivadas , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Mesângio Glomerular/metabolismo , Masculino , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Edulcorantes/farmacologia , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Hydrogen has been deemed as an ideal substitute fuel to fossil energy because of its renewability and the highest energy density among all chemical fuels. One of the most economical, ecofriendly, and high-performance ways of hydrogen production is electrochemical water splitting. Recently, 2D transition metal dichalcogenides (also known as 2D TMDs) showed their utilization potentiality as cost-effective hydrogen evolution reaction (HER) catalysts in water electrolysis. Herein, recent representative research efforts and systematic progress made in 2D TMDs are reviewed, and future opportunities and challenges are discussed. Furthermore, general methods of synthesizing 2D TMDs materials are introduced in detail and the advantages and disadvantages for some specific methods are provided. This explanation includes several important regulation strategies of creating more active sites, heteroatoms doping, phase engineering, construction of heterostructures, and synergistic modulation which are capable of optimizing the electrical conductivity, exposure to the catalytic active sites, and reaction energy barrier of the electrode material to boost the HER kinetics. In the last section, the current obstacles and future chances for the development of 2D TMDs electrocatalysts are proposed to provide insight into and valuable guidelines for fabricating effective HER electrocatalysts.
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OBJECTIVE: To observe the prevalence, blood pressure change in prehypertensive population and associated cardiovascular risk factors. METHODS: Data from a prehypertensive cohort defined with the JNC-7 prehypertension diagnostic criteria were obtained in the employees of kailuan group during the health examination between 2006 to 2007 and the same population was revisited between 2008 to 2009 to observe the change of blood pressure and the associated determinants for blood pressure change. RESULTS: (1) There were 25 474 prehypertensive during the 1(st) visit and 8361 subjects developed hypertension during the 2(nd) visit (35.3% in men and 23.3% in women, 27.2% with baseline blood pressure 120 - 129/80 - 84 mm Hg (1 mm Hg = 0.133 kPa) and 43.8% with baseline blood pressure 130 - 139/85 - 89 mm Hg, 34.3% with risk factors and 19.9% without risk factors). (2) Multiple logistic regression analysis showed that the baseline SBP, waist circumference, age, BMI, gender (male), DBP, TC, FBG, TG, LDL-C were the risk factors of blood pressure progression with a RR (95%CI) of 1.052 (1.048 - 1.056), 1.009 (1.006 - 1.013), 1.023 (1.021 - 1.026), 1.063 (1.052 - 1.074), 1.554 (1.442 - 1.675), 1.036 (1.029 - 1.043), 1.064 (1.037 - 1.093), 1.043 (1.024 - 1.062), 1.041 (1.021 - 1.062) and 1.035 (1.000 - 1.072), respectively. CONCLUSION: A third (32.8%) prehypertensive population progressed into hypertension after two years, baseline SBP, waist circumference, age, BMI, gender (male), DBP, TC, FBG, TG, LDL-C were the risk factors of predicting blood pressure progression.
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Glicemia/metabolismo , Colesterol/sangue , Pré-Hipertensão/epidemiologia , Adulto , Pressão Sanguínea , Doenças Cardiovasculares/epidemiologia , Feminino , Seguimentos , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Circunferência da CinturaRESUMO
AIM: Both adrenomedullin (ADM) and adrenotensin (ADT) are derived from the same propeptide precursor, and both act as circulating hormones and local paracrine mediators with multiple biological activities. Compared with ADM, little is known about how ADT achieves its functions. In the present study, we investigated the effect of ADT on cell proliferation and transforming growth factor-beta (TGF-beta) secretion in cultured renal mesangial cells (MCs) and determined whether angiotensin II (Ang II) was involved in mediating this process. METHODS: Cell proliferation was measured by bromodeoxyuridine (BrdU) incorporation assay, Ang II levels were assayed using an enzyme immunoassay, and real time PCR was used to measure Ang II type 1 (AT1) receptor, Ang II type 2 (AT2) receptor, angiotensinogen (AGT), renin, angiotensin converting enzyme (ACE) and TGF-beta1 mRNA levels. TGF-beta1 and collagen type IV protein levels in cell media were measured using enzyme-linked immunoassays. RESULTS: ADT treatment induced cell proliferation in a concentration-dependent manner; it also increased the levels of TGF-beta1 mRNA and protein as well as collagen type IV excretion by cultured MCs. ADT treatment increased renin and AGT mRNAs as well as Ang II protein, but did not affect the ACE mRNA level. ADT up-regulated angiotensin AT1 receptor mRNA, but not that of the AT2 receptor. The angiotensin AT1 receptor antagonist losartan blocked the effects of ADT-induced cell proliferation, TGF-beta1 and collagen type IV synthesis and secretion. CONCLUSION: ADT has a stimulating role in cell proliferation in cultured MCs. Increases in the levels of Ang II and the AT1 receptor after ADT treatment mediate the stimulating effects of ADT on cell proliferation and extracellular matrix synthesis and secretion.
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Adrenomedulina/metabolismo , Angiotensina II/metabolismo , Proliferação de Células , Células Mesangiais/citologia , Fragmentos de Peptídeos/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Angiotensinogênio/genética , Angiotensinogênio/metabolismo , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo IV/metabolismo , Regulação da Expressão Gênica , Losartan/farmacologia , Células Mesangiais/metabolismo , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , RNA Mensageiro/genética , Ratos , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 1 de Angiotensina/metabolismo , Renina/genética , Renina/metabolismo , Fator de Crescimento Transformador beta1/metabolismoRESUMO
AIM: To investigate the role of adenosine 5'-triphosphate (ATP)-induced generation of reactive oxygen species (ROS) and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the production of transforming growth factor-beta1 (TGF-beta1) in cultured rat glomerular mesangial cells under high-glucose conditions. METHODS: Subconfluent glomerular mesangial cells were serum-starved for 24 h and pretreated with suramin, diphenylenechloride iodonium (DPI) or PD98059 followed by stimulation with a high concentration of glucose (30 mmol/L D-glucose) or ATP (300 micromol/L). Extracellular and total ATP and ROS production were detected using commercially available kits. Phosphorylation of ERK1/2 was evaluated by Western blot. TGF-beta1 mRNA expression was examined by real-time PCR. RESULTS: Suramin had a dose-dependent inhibitory effect on the generation of ROS induced by high glucose. Extracellular ATP production by mesangial cells increased markedly after a 2-h incubation with high glucose. ROS production was upregulated in mesangial cells after 5 min incubation with 300 micromol/L ATP and was sustained for 120 min. ERK1/2 was significantly activated after 5 min incubation of mesangial cells with ATP, this activation was partially inhibited by DPI. The effects of high glucose on TGF-beta1 mRNA were markedly inhibited by suramin, DPI or PD98059. CONCLUSION: Our results suggest that a high concentration of glucose increases the extracellular levels of ATP in mesangial cells within a short time-frame. ATP, in turn, activates ERK1/2, an effect which is at least partially dependent on ROS, which results in the upregulation of TGF-beta1.
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Monofosfato de Adenosina/análogos & derivados , Glucose/metabolismo , Células Mesangiais/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tionucleotídeos/metabolismo , Fator de Crescimento Transformador beta1/genética , Monofosfato de Adenosina/metabolismo , Monofosfato de Adenosina/farmacologia , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Linhagem Celular , Flavonoides/farmacologia , Glucose/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Oniocompostos/farmacologia , Fosforilação , Ratos , Transdução de Sinais/fisiologia , Suramina/farmacologia , Tionucleotídeos/farmacologia , Fator de Crescimento Transformador beta1/metabolismo , Regulação para CimaRESUMO
AIMS: Hydrogen sulphide (H(2)S) is an endogenously generated gaseous transmitter that has recently been suggested to regulate cardiovascular functions. To date, there is no direct evidence for a potential role of H(2)S in regulating calcium channels in the heart. The present study aims to examine the hypothesis that H(2)S is a novel inhibitor of the L-type calcium channel current (I(Ca,L)). METHODS AND RESULTS: Electrophysiological measurements were performed in cardiomyocytes isolated from Wistar-Kyoto and spontaneously hypertensive rats. Bath application of 100 microM NaHS (a H(2)S donor) significantly reduced the time required for the repolarization of the action potential. Inhibition of the peak I(Ca,L) by NaHS was determined to be concentration-dependent (25, 50, 100, 200, and 400 microM). NaHS inhibited the recovery from depolarization-induced inactivation. Electric field-induced [Ca(2+)]i transients and contraction of single cardiomyocytes and isolated papillary muscles were reduced by NaHS treatment. In contrast, caffeine induced an increase in [Ca(2+)]i that was not altered by NaHS. NaHS had no effect on the K(ATP) current or on the levels of cAMP and cGMP in the current study. CONCLUSION: H(2)S is a novel inhibitor of L-type calcium channels in cardiomyocytes. Moreover, H(2)S-induced inhibition of [Ca(2+)]i appears to be a secondary effect owing to its initial action towards I(Ca,L). The inhibitory effect of H(2)S on I(Ca,L) requires further investigation, particularly in the exploration of new pathways involved in cardiac calcium homeostasis and disease pathology.
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Canais de Cálcio Tipo L/metabolismo , Sinalização do Cálcio , Sulfeto de Hidrogênio/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Potenciais de Ação , Animais , Bloqueadores dos Canais de Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/efeitos dos fármacos , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Estimulação Elétrica , Canais KATP/metabolismo , Masculino , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Músculos Papilares/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Sulfetos/metabolismo , Sulfetos/farmacologia , Fatores de TempoRESUMO
OBJECTIVE: To observe the effect of electroacupuncture (EA) on anti-oxidant function of Leydig cells in aged rats with low testosterone, so as to reveal its underlying mechanism of anti-aging of male reproduction. METHODS: Eighteen 20 months old SD rats were divided into aged control, medication and EA groups(n=6 in each group), and other 6 young male SD rats (2 months of age) were used as the youth control group. The rats of the youth and the aged control groups received subcutaneous injection of 0.9% normal saline (7 mg·kg-1·3 d-1) for 8 weeks, and those of the medication group received abdominal subcutaneous injection of Testosterone Propionate (7 mg·kg-1·3 d-1) for 8 weeks. EA (2 Hz/100 Hz, 1 mA) was applied to bilateral "Shenshu" (BL23) and "Guanyuan" (CV4) for 15 min, once daily for 8 weeks except the weekends. The levels of serum total testosterone (TT) and free testosterone (FT) were determined by enzyme linked immune sorbent assay (ELISA), the immunoactivity of phosphorylated extracellular signal-regulated protein kinase (p-ERK) was detected by immunohistochemistry, and the expression levels of ERK, p-ERK, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins in the testis tissues were determined by Western blot. RESULTS: Before and after the treatment, the levels of serum TT and FT in the aged control group were significantly lower than those of the youth control group (P<0.01). After the treatment, the serum TT and FT contents in the EA and medication groups were obviously higher than those in the aged control group (P<0.01). Compared with the youth control group, the expression levels of ERK, p-ERK, Nrf2 and HO-1 proteins were significantly down-regulated in the aged control group (P<0.01), while in comparison with the aged control group, the expression levels of ERK, p-ERK, Nrf2 and HO-1 proteins were significantly up-regulated in the medication and EA groups (P<0.01). The therapeutic effect of EA was notably superior to that of medication in up-regulating the immunoactivity of p-ERK, and the expression levels of ERK, p-ERK, Nrf2 and HO-1 proteins (P<0.01). No significant differences were found between the EA and medication groups in the increased levels of serum TT and FT after the intervention (P>0.05). CONCLUSION: EA intervention may increase testosterone level of the aged rats, which may be related to its effects in triggering ERK /Nrf2 /HO-1 signaling (anti-oxidative stress signal pathway) in the testis.
Assuntos
Eletroacupuntura , Animais , Heme Oxigenase (Desciclizante) , Células Intersticiais do Testículo , Masculino , Fator 2 Relacionado a NF-E2 , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , TestosteronaRESUMO
OBJECTIVE: To observe the effect of warm needle moxibustion (WNM), mild moxibustion and electroacupuncture (EA) of "Shenshu" (BL23) and "Guanyuan" (CV4) on serum gonadal hormone levels and related gene expression in the hypothalamus and testis in aged rats, so as to explore their underlying mechanisms in anti-aging. METHODS: Forty male SD male rats were randomly divided into aged control, WNM, mild moxibustion, EA and medication groups (n ï¼ 8 in each group), and other 8 male young adult SD rats were used as the youth control group. WNM (acupuncture plus moxibustion), mild moxibustion or EA (2 Hz /100 Hz, 1 mA) was separately applied to CV4 and bilateral BL23 for 15 min, once daily, 5 days a week for 8 weeks. Rats of the medication group received subcutaneous injection of testosterone propionate injection (7 mg/kg), once every 3 days, and those of the aged and youth groups received the same dose of 0.9% NaCl solution for 8 weeks. The levels of serum testoste-rone (T) and gonadotropin-releasing hormone (GnRH) were measured by ELISA. The expression of Kisspeptin (KISS-1), G protein-coupled receptors 54 (GPR54), RFamide-related peptide-3 (RFRP-3) and GPR147 mRNAs in the hypothalamus and GnRH-R, GPR54 and GPR147 mRNAs in the testis tissues were detected by quantitative real-time PCR. RESULTS: The levels of serum T and GnRH, and the expressions of KISS-1, GPR54, RFRP-3 and GPR147 mRNAs in the hypothalamus and GnRH-R and GPR54 mRNAs in the testis in the aged rats were significantly lower than those in the youth rats (P<0.05), while the expression level of GPR147 mRNA of the testis tissue was obviously higher in the aged group than that in the youth group (P<0.05). Follo-wing the treatment, the lowered serum T and GnRH contents, the down-regulated expression levels of hypothalamic KISS-1, GPR54, RFRP-3 and GPR147 mRNAs and testicle GnRH-R and GPR54 mRNAs, as well as the up-regulated testicle GPR147 mRNA expression in the aged rats were reversed in the WNM, mild moxibustion and EA groups (not the medication group except serum T) in comparison with the aged control group (P<0.05). The therapeutic effects of WNM, mild moxibustion and EA were significantly superior to those of medication in up-regulating serum GnRH content and expression levels of KISS-1, GPR54, RFRP-3 and GPR147 mRNAs in the hypothalamus and GnRH-R, GPR54 and GPR147 mRNAs in the testis (P<0.05). No significant differences were found among the WNM, mild moxibustion and EA groups in serum T and GnRH contents, and the expression levels of KISS-1, GPR54, RFRP-3 and GPR147 mRNAs in the hypothalamus and GnRH-R and GPR54 and GPR147 mRNAs in the testis (P>0.05)ï¼. CONCLUSION: The WNM, mild moxibustion and EA therapies have an anti-aging effect by increasing serum T and GnRH levels in aged rats, which is possibly related to their effects in up-regulating the expression of hypothalamic KISS-1, GPR54, RFRP-3 and GPR147 mRNAs and testicle GnRH-R and GPR54 mRNAs, as well as down-regulating testicle GPR147 mRNA expression. The therapeutic effect of WNM, mild moxibustion and EA is evidently superior to that of medication.