Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Biochim Biophys Acta Mol Basis Dis ; 1870(3): 166944, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37952827

RESUMEN

Sema4D (CD100) is closely related to pathological and physiological processes, including tumor growth, angiogenesis and cardiac development. Nevertheless, the role and mechanism of Sema4D in cardiac hypertrophy are still unclear to date. To assess the impact of Sema4D on pathological cardiac hypertrophy, TAC surgery was performed on C57BL/6 mice which were transfected with AAV9-mSema4D-shRNA or AAV9-mSema4D adeno-associated virus by tail vein injection. Our results indicated that Sema4D knockdown mitigated cardiac hypertrophy, fibrosis and dysfunction when exposed to pressure overload, and Sema4D downregulation markedly inhibited cardiomyocyte hypertrophy induced by angiotensin II. Meanwhile, Sema4D overexpression had the opposite effect in vitro and in vivo. Furthermore, analysis of signaling pathways showed that Sema4D activated the MAPK pathway during cardiac hypertrophy induced by pressure overload, and the pharmacological mitogen-activated protein kinase kinase 1/2 inhibitor U0126 almost completely reversed Sema4D overexpression-induced deteriorated phenotype, resulting in improved cardiac function. Further research indicated that myocardial hypertrophy induced by Sema4D was closely related to the expression of the pyroptosis-related proteins PP65, NLRP3, caspase-1, ASC, GSDMD, IL-18 and IL-1ß. In conclusion, our study demonstrated that Sema4D regulated the process of pathological myocardial hypertrophy through modulating MAPK/NF-κB/NLRP3 pathway, and Sema4D may be the promising interventional target of cardiac hypertrophy and heart failure.


Asunto(s)
Antígenos CD , Miocitos Cardíacos , FN-kappa B , Semaforinas , Animales , Ratones , Cardiomegalia/metabolismo , Ratones Endogámicos C57BL , Miocitos Cardíacos/metabolismo , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo
2.
Int Immunopharmacol ; 121: 110222, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37343367

RESUMEN

BACKGROUND AND PURPOSE: Panaxynol (PNN) is a common natural minor component in Umbelliferae plants. Many clinical studies have shown that PNN exhibits nutritional value and anti-inflammatory and other pharmacological activities. However, whether PNN can mediate cardiac ischemia/reperfusion injury (IRI) remains unclear. Here, we aimed to determine the potential effects of PNN on myocardial IRI. METHODS: Myocardial IRI was stimulated in a mouse IRI model, and neonatal rat ventricle myocytes (NRVMs) were exposed to hypoxia/reoxygenation to construct in an vitro model. Myocardial infarction size, myocardial tissue injury, myocardial apoptotic index, hemodynamic monitoring, pyroptosis-related proteins, cardiac enzyme activities and inflammatory responses were examined to assess myocardial injury. RESULTS: It was found that PNN administration markedly reduced myocardial infarct size and apoptosis, suppressed myocardial damage and cell pyroptosis, attenuated pro-inflammatory cytokines and neutrophil infiltration via NLRP3 inhibitor. More importantly, PNN treatment remarkably decreased the expression of TLR4/NF-κB pathway-associated proteins and NLRP3-related pyroptosis proteins by HMGB1 inhibitor. PNN also enhanced cell viability, reduced cardiac enzyme activities, suppressed apoptosis and attenuated inflammation in the isolated NRVMs. Furthermore, vitro studies indicated that MCC950 (a NLRP3 inhibitor) increased the anti-inflammatory and anti-apoptotic effects of PNN on NRVMs via HMGB1/TLR4 pathway. CONCLUSION: To sum up, our results demonstrate that PNN exhibits a cardioprotective effect by modulating heart IRI-induced apoptosis and pyroptosis via HMGB1/TLR4/NF-κB pathway, thereby inhibiting NLRP3 inflammasome stimulation.


Asunto(s)
Proteína HMGB1 , Infarto del Miocardio , Daño por Reperfusión Miocárdica , Ratones , Ratas , Animales , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Piroptosis , Proteína HMGB1/metabolismo , Receptor Toll-Like 4/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Apoptosis , Miocitos Cardíacos/metabolismo , Inflamasomas/metabolismo , Infarto del Miocardio/metabolismo , Modelos Animales de Enfermedad
3.
RSC Adv ; 13(16): 10987-11001, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37033441

RESUMEN

Hepatic fibrosis (HF) is a chronic hepatic pathological process induced by various liver injuries, with few available therapies. Previous research studies revealed that HF is characterized by the accumulation of excess extracellular matrix in the liver, mainly overexpressed by activated hepatic stellate cells (HSC). Therefore, HSC have been targeted in clinical trials for the management of HF. The aim of the present study was to develop an anti-HF drug delivery system with acrylic resin (Eudragit® RS100, Eud RS100) nanoparticles (NPs) through modification by retinoic acid (RA), modified for binding the retinol-binding protein reporter (RBPR) in HSC. Galangin (GA), is a multiple effects flavonoid which has demonstrated an anti-HF effect in our previous studies. In this study, GA was utilized for the treatment of HF. The results revealed that the NPs were well formed (diameter: 70 nm), spherical in shape, and exhibited uniform distribution and a high encapsulation efficiency. Moreover, a prominent controlled release effect and a significant increase in bioavailability was observed following the encapsulation of GA in NPs. These findings indicated that the limitation of low bioavailability due to the hydrophobic feature of GA was overcome. Furthermore, the pharmacodynamics studies demonstrated that NPs could drastically influence the anti-HF effects of GA after modification with retinoic acid. The results of the present study suggested that retinoic acid-modified GA NPs represent a promising candidate in the development of an anti-HF drug delivery system for the treatment of HF.

4.
Phys Rev Lett ; 130(10): 106203, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36962034

RESUMEN

We propose and study a two-dimensional phase of shifted charge density waves (CDW), which is constructed from an array of weakly coupled 1D CDW wires whose phases shift from one wire to the next. We show that the fully gapped bulk CDW has topological properties, characterized by a nonzero Chern number, that imply edge modes within the bulk gap. Remarkably, these edge modes exhibit spectral pseudoflow as a function of position along the edge, and are thus dual to the chiral edge modes of Chern insulators with their spectral flow in momentum space. Furthermore, we show that the CDW edge modes are stable against interwire coupling. Our predictions can be tested experimentally in quasi-1D CDW compounds such as Ta_{2}Se_{8}I.

5.
ISA Trans ; 136: 503-524, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36379760

RESUMEN

This paper investigates the flight dynamics of the aircraft with wing asymmetric damage and the fault-tolerant control problem to improve the stability and flight quality of damaged aircraft. A high-fidelity wing asymmetric damaged aircraft nonlinear model is developed, as well as the impact of wing asymmetric damage on the physical and aerodynamic properties of the aircraft is also analyzed. The trim strategies for damaged aircraft are investigated to achieve a rapid estimation of trim states after damage occurs. This paper presents a robust cascaded nonlinear fault-tolerant control framework that integrates the incremental nonlinear dynamic inversion control with improved piecewise-constant-based nonlinear L1 adaptive control for the stability control to enhance the stability and tracking performance of the damaged aircraft. Theoretical analysis proves that the presented fault-control structure is robust to disturbances and can decouple rapidity and robustness while guaranteeing steady-state and transient performance. Finally, the hardware-in-the-loop flight control experiment platform is developed to validate the cascaded nonlinear fault-tolerant controller. In the experiment, the proposed controller is verified under wing asymmetric damage and compared with existing methods. Experimental results show that the proposed fault-tolerant control is able to overcome wing asymmetric damage and significantly improve the tracking performance of the damaged aircraft even with 27.2% of the severe damage to the left-wing.

6.
Food Funct ; 13(23): 12077-12092, 2022 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-36367287

RESUMEN

Aims: The proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in the pathological process of neointima formation after vascular injury. Galangin, an extract of the ginger plant galangal, is involved in numerous biological activities, including inhibiting the proliferation and migration of tumor cells, but its effect on VSMCs is unknown. This study focused on the role and mechanism of galangin in the neointima formation induced by vascular injury. Methods and results: In this study, we found that galangin restrained the PDGF-BB-induced proliferation, migration and phenotypic switching of VSMCs in a concentration-dependent manner. In vivo, we established a model of carotid artery balloon injury in rats, followed by intragastric administration of galangin (40 mg kg-1 day-1 or 80 mg kg-1 day-1) for 14 or 28 consecutive days. Then, the degree of neointima hyperplasia was evaluated by H&E staining, and the level of relevant protein expression was assessed by immunofluorescence and western blotting. In vitro, we isolated and grew primary rat aortic smooth muscle cells, which were treated with PDGF-BB and different doses of galangin, and then CCK-8 assay, wound healing assay, transwell assay, western blotting and immunofluorescence assays were performed. We found that galangin significantly inhibited PDGF-BB-induced proliferation, migration, and phenotypic switching of VSMCs and promoted autophagy in VSMCs in vitro, and galangin significantly inhibited neointimal hyperplasia after the common carotid artery balloon injury in rats. In terms of mechanisms, galangin inhibited the PI3K/AKT/mTOR pathway, thereby suppressing VSMC's switch from a contractile to a synthetic phenotype, inhibiting VSMC proliferation, migration and phenotypic switching and upregulating the Beclin1 protein expression levels and the ratio of LC3BII/I, promoting VSMC autophagy, and thereby inhibiting neointimal hyperplasia after vascular injury. Conclusion: Our study suggests that galangin inhibits neointimal hyperplasia after vascular injury by inhibiting smooth muscle cell proliferation, migration and phenotypic switching and by promoting autophagy, and that galangin may be a promising drug for the prevention and treatment of vascular restenosis after PCI.


Asunto(s)
Traumatismos de las Arterias Carótidas , Intervención Coronaria Percutánea , Lesiones del Sistema Vascular , Ratas , Animales , Neointima/tratamiento farmacológico , Neointima/metabolismo , Neointima/patología , Becaplermina/metabolismo , Becaplermina/farmacología , Becaplermina/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Lesiones del Sistema Vascular/tratamiento farmacológico , Lesiones del Sistema Vascular/genética , Lesiones del Sistema Vascular/metabolismo , Músculo Liso Vascular , Hiperplasia/metabolismo , Hiperplasia/patología , Movimiento Celular , Proliferación Celular , Ratas Sprague-Dawley , Traumatismos de las Arterias Carótidas/tratamiento farmacológico , Traumatismos de las Arterias Carótidas/metabolismo , Traumatismos de las Arterias Carótidas/patología , Miocitos del Músculo Liso , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Células Cultivadas
7.
Int J Mol Sci ; 23(20)2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36293441

RESUMEN

Increasing evidence has shown that vascular aging has a key role in the pathogenesis of vascular diseases. P300/CBP-associated factor (PCAF) is involved in many vascular pathological processes, but the role of PCAF in vascular aging is unknown. This study aims to explore the role and underlying mechanism of PCAF in vascular aging. The results demonstrated that the expression of PCAF was associated with age and aging, and remarkably increased expression of PCAF was present in human atherosclerotic coronary artery. Downregulation of PCAF could reduce angiotensin II (AngII)-induced senescence of rat aortic endothelial cells (ECs) in vitro. In addition, inhibition of PCAF with garcinol alleviated AngII-induced vascular senescence phenotype in mice. Downregulation of PCAF could alleviate AngII-induced oxidative stress injury in ECs and vascular tissue. Moreover, PCAF and nuclear factor erythroid-2-related factor 2 (Nrf2) could interact directly, and downregulation of PCAF alleviated vascular aging by promoting the activation of Nrf2 and enhancing the expression of its downstream anti-aging factors. The silencing of Nrf2 with small interfering RNA attenuated the protective effect of PCAF downregulation from vascular aging. These findings indicate that downregulation of PCAF alleviates oxidative stress by activating the Nrf2 signaling pathway and ultimately inhibits vascular aging. Thus, PCAF may be a promising target for aging-related cardiovascular disease.


Asunto(s)
Angiotensina II , Factor 2 Relacionado con NF-E2 , Animales , Humanos , Ratones , Ratas , Envejecimiento , Angiotensina II/metabolismo , Regulación hacia Abajo , Células Endoteliales/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Factores de Transcripción p300-CBP/metabolismo , ARN Interferente Pequeño , Transducción de Señal
8.
Heliyon ; 8(9): e10473, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36065322

RESUMEN

Metabolic reprogramming is a distinctive characteristic of SARS-CoV-2 infection, which refers to metabolic changes in hosts triggered by viruses for their survival and spread. It is current urgent to understand the metabolic health status of COVID-19 survivors and its association with long-term health consequences of infection, especially for the predominant non-severe patients. Herein, we show systemic metabolic signatures of survivors of non-severe COVID-19 from Wuhan, China at six months after discharge using metabolomics approaches. The serum amino acids, organic acids, purine, fatty acids and lipid metabolism were still abnormal in the survivors, but the kynurenine pathway and the level of itaconic acid have returned to normal. These metabolic abnormalities are associated with liver injury, mental health, energy production, and inflammatory responses. Our findings identify and highlight the metabolic abnormalities in survivors of non-severe COVID-19, which provide information on biomarkers and therapeutic targets of infection and cues for post-hospital care and intervention strategies centered on metabolism reprogramming.

9.
J Cell Mol Med ; 25(21): 10224-10235, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34601814

RESUMEN

Cardiomyocyte apoptosis is the main reason of cardiac injury after myocardial ischaemia-reperfusion (I/R) injury (MIRI), but the role of p300/CBP-associated factor (PCAF) on myocardial apoptosis in MIRI is unknown. The aim of this study was to investigate the main mechanism of PCAF modulating cardiomyocyte apoptosis in MIRI. The MIRI model was constructed by ligation of the rat left anterior descending coronary vessel for 30 min and reperfusion for 24 h in vivo. H9c2 cells were harvested after induced by hypoxia for 6 h and then reoxygenation for 24 h (H/R) in vitro. The RNA interference PCAF expression adenovirus was transfected into rat myocardium and H9c2 cells. The area of myocardial infarction, cardiac function, myocardial injury marker levels, apoptosis, inflammation and oxidative stress were detected respectively. Both I/R and H/R remarkably upregulated the expression of PCAF, and downregulation of PCAF significantly attenuated myocardial apoptosis, inflammation and oxidative stress caused by I/R and H/R. In addition, downregulation of PCAF inhibited the activation of NF-κB signalling pathway in cardiomyocytes undergoing H/R. Pretreatment of lipopolysaccharide, a NF-κB pathway activator, could blunt these protective effects of PCAF downregulation on myocardial apoptosis in MIRI. These results highlight that downregulation of PCAF could reduce cardiomyocyte apoptosis by inhibiting the NF-κB pathway, thereby providing protection for MIRI. Therefore, PCAF might be a promising target for protecting against cardiac dysfunction induced by MIRI.


Asunto(s)
Apoptosis/genética , Daño por Reperfusión Miocárdica/etiología , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , FN-kappa B/metabolismo , Transducción de Señal , Factores de Transcripción p300-CBP/genética , Animales , Biomarcadores , Línea Celular , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Regulación hacia Abajo , Regulación de la Expresión Génica , Pruebas de Función Cardíaca , Daño por Reperfusión Miocárdica/diagnóstico , Estrés Oxidativo , Ratas , Factores de Transcripción p300-CBP/metabolismo
10.
Food Funct ; 12(21): 10950-10966, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34647944

RESUMEN

Vascular intimal hyperplasia is a hallmark event in vascular restenosis. The excessive proliferation, migration and phenotypic transformation of vascular smooth muscle cells (VSMCs) play important roles in the pathological mechanism of vascular intimal hyperplasia. Physalin B is an alcoholate isolated from Physalis (Solanaceae) that has a wide range of biological activities. However, the effect of physalin B on VSMCs is currently unclear. In this study, we demonstrated that physalin B significantly inhibited the proliferation, migration and phenotypic transformation of VSMCs induced by PDGF-BB. Physalin B also reduced inflammation and oxidative stress in VSMCs induced by PDGF-BB. Mechanistic studies showed that physalin B plays a role mainly by activating Nrf2. After Nrf2 activation, physalin B mitigates oxidative stress by enhancing the expression of the antioxidant gene HO-1; on the other hand, physalin B inhibits the NF-κB pathway to alleviate the inflammatory response. These two effects ultimately reduce the proliferation, migration and phenotypic transformation of VSMCs induced by PDGF-BB. In addition, in the mouse carotid artery ligation model, physalin B prevented intimal hyperplasia and inhibited the proliferation, migration and phenotypic transformation of cells in the hyperplastic intima. In conclusion, we provided significant evidence that physalin B abrogates PDGF-BB-induced VSMC proliferation, migration, phenotypic transformation and intimal hyperplasia by activating Nrf2-mediated signal transduction. Therefore, physalin B may be a potential therapeutic agent for preventing or treating restenosis.


Asunto(s)
Becaplermina/toxicidad , Traumatismos de las Arterias Carótidas/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Músculo Liso Vascular/citología , Miocitos del Músculo Liso/efectos de los fármacos , Secoesteroides/farmacología , Animales , Antioxidantes/farmacología , Traumatismos de las Arterias Carótidas/patología , Movimiento Celular/efectos de los fármacos , Constricción Patológica/tratamiento farmacológico , Regulación hacia Abajo , Regulación de la Expresión Génica/efectos de los fármacos , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Inflamación/tratamiento farmacológico , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Miocitos del Músculo Liso/fisiología , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Distribución Aleatoria
11.
J Appl Physiol (1985) ; 131(3): 966-976, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34236244

RESUMEN

Coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been associated with cardiovascular features, which may be deteriorated in patients with cancer. However, cardiac outcomes of cancer patients with COVID-19 have not been closely examined. We retrospectively assessed 1,244 patients with COVID-19 from February 1 to August 31, 2020 (140 cancer and 1,104 noncancer patients). Demographic and clinical data were obtained and compared between cancer and noncancer groups. Including the cardiac biomarkers, we also analyzed laboratory findings between these two groups. Risk factors for in-hospital mortality were identified by multivariable Cox regression models. For cancer group, 56% were in severe and critical status with more diabetes and immune deficiency, whereas the proportion was 10% for noncancer group. Patients with cancer had increased levels of leukocyte, neutrophil count, and blood urea nitrogen (BUN) (all P < 0.01), whereas lymphocyte count was significantly lower (P < 0.001). The most common solid tumor types were gastrointestinal cancer (26%), lung cancer (21%), and breast and reproductive cancer (both 19%). There is a rising for cardiac biomarkers, including pro-B-type natriuretic peptide (Pro-BNP), sensitive troponin I (cTnI), myoglobin (MYO), creatine kinase-MB (CK-MB), as well as D-Dimer in COVID-19 cancer population, especially in deceased subjects with cancer. The 30-day in-hospital mortality in cancer group was dramatically raised than that in noncancer group (12.9% vs. 4.0%, P < 0.01). In multivariable Cox regression models, fever, disease severity status, and underlying diseases were risk factors for mortality. COVID-19 patients with cancer relate to deteriorating conditions and poor cardiac outcomes accompanied by a high in-hospital mortality, which warrants more aggressive treatment.NEW & NOTEWORTHY Our study indicates that the 30-day mortality is higher in COVID-19 patients with cancer; more COVID-19 patients with cancer are in severe and critical status; age, respiratory rate, neutrophil count, AST, BUN, MYO, Pro-BNP, disease severity status, underlying diseases, and fever are risk factors for in-hospital mortality among COVID-19 cancer cases; COVID-19 patients with cancer display severely impaired myocardium, damaged heart function, and imbalanced homeostasis of coagulation; what is more, those with both cancer and CVD have more significantly increased Pro-BNP and D-Dimer level.


Asunto(s)
COVID-19 , Neoplasias , Humanos , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2
12.
Nat Mater ; 20(10): 1353-1357, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34112979

RESUMEN

Intertwining quantum order and non-trivial topology is at the frontier of condensed matter physics1-4. A charge-density-wave-like order with orbital currents has been proposed for achieving the quantum anomalous Hall effect5,6 in topological materials and for the hidden phase in cuprate high-temperature superconductors7,8. However, the experimental realization of such an order is challenging. Here we use high-resolution scanning tunnelling microscopy to discover an unconventional chiral charge order in a kagome material, KV3Sb5, with both a topological band structure and a superconducting ground state. Through both topography and spectroscopic imaging, we observe a robust 2 × 2 superlattice. Spectroscopically, an energy gap opens at the Fermi level, across which the 2 × 2 charge modulation exhibits an intensity reversal in real space, signalling charge ordering. At the impurity-pinning-free region, the strength of intrinsic charge modulations further exhibits chiral anisotropy with unusual magnetic field response. Theoretical analysis of our experiments suggests a tantalizing unconventional chiral charge density wave in the frustrated kagome lattice, which can not only lead to a large anomalous Hall effect with orbital magnetism, but also be a precursor of unconventional superconductivity.

13.
Transl Pediatr ; 10(3): 560-568, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33850814

RESUMEN

BACKGROUND: Telemedicine is becoming an emerging innovative supplement to the traditional medical system in China. In the present study, we described the rapid implementation of the telemedicine in pediatrics during the coronavirus disease 2019 (COVID-19) outbreak and explored its value in response to the demand for pediatric medical services during the epidemic. METHODS: An Internet-based platform for multidisciplinary online medical consultation was established on February 8, 2020, by a national children's medical center in China. The medical data of the traditional hospital visits and novel online visits from the first two months (February 8 to March 31) after the establishment of the platform were collected and analyzed. The demographic features, changes in the disease spectrum and characteristics of online medical services were described. RESULTS: The total number of visits was significantly lower (by 75.3%) than that of in the same period in the previous year. The disease spectrum was different with a significant decrease of >95% in the number of patients with infectious or contagious diseases. The online visits accounted for 14.7% of all visits. Online patients came from all over the country, covering 91% of the administrative regions of China, and the largest proportion of inquiries were for infants (33.7%) (P<0.01). The response rate of experts to requests for online consultations was 100%. During the study period, 266 experts from 25 pediatric specialties completed 12,318 effective consultations, proving different degrees of online supplementation for various specialties (4.3-168.4%). Online consultations mainly addressed two types of problems: (I) accessibility of the traditional hospital visits and (II) consultations regarding an illness. Data from pediatric nephrology showed that 96% of the patients with stable chronic kidney disease successfully received follow-up medication adjustment guidance through the online platform. CONCLUSIONS: The traditional hospital medical services have been affected by the COVID-19 outbreak. The multidisciplinary online medical consultation system is a strategy to actively respond to the medical needs of children during unique periods.

14.
Phys Rev Lett ; 127(25): 256403, 2021 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-35029418

RESUMEN

The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co_{3}Sn_{2}S_{2}, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order. We further observe that topological Fermi arcs disappear in the paramagnetic phase, suggesting the annihilation of exchange-split Weyl points. Our findings indicate that magnetic exchange collapse naturally drives Weyl fermion annihilation, opening new opportunities for engineering topology under correlated order parameters.

15.
Materials (Basel) ; 13(19)2020 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-32977667

RESUMEN

The hot deformation behaviors of the new 6063 aluminum alloy modified by rare earth Y and Al-Ti-B master alloy were studied through isothermal hot compression experiments on the Gleeble-3800 thermal simulator. By characterizing the flow curves, constitutive models, hot processing maps, and microstructures, we can see from the true stress-true strain curves that the flow stress decreases with the increase of deformation temperature and the decrease of strain rate. Through the calculation of the constitutive equation, we derived that the activation energy of the new composite modified 6063 aluminum alloy is 224.570 KJ/mol. we roughly obtained its excellent hot processing range of temperatures between 470-540 °C and the strain rates of 0.01-0.1 s-1. The verification of the deformed microstructure shows that with the decrease of lnZ, the grain boundary changes from a low-angle one to a high-angle one and the dynamic recrystallization is dominated by geometric dynamic recrystallization and continuous dynamic recrystallization. Analysis of typical samples at 480 °C/0.01 s-1 shows that the addition of rare earth Y mainly helps form Al3Y5 and AlFeSiY phases, thus making the alloy have the performance of high-temperature recrystallization, which is beneficial to the hot workability of the alloy.

16.
Sensors (Basel) ; 20(10)2020 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-32456340

RESUMEN

Aimed at improving upon the disadvantages of the single centralized Kalman filter for integrated navigation, including its fragile robustness and low solution accuracy, a nonlinear double model based on the improved decentralized federated extended Kalman filter (EKF) for integrated navigation is proposed. The multisensor error model is established and simplified in this paper according to the near-ground short distance navigation applications of small unmanned aerial vehicles (UAVs). In order to overcome the centralized Kalman filter that is used in the linear Gaussian system, the improved federated EKF is designed for multisensor-integrated navigation. Subsequently, because of the navigation requirements of UAVs, especially for the attitude solution accuracy, this paper presents a nonlinear double model that consists of the nonlinear attitude heading reference system (AHRS) model and nonlinear strapdown inertial navigation system (SINS)/GPS-integrated navigation model. Moreover, the common state parameters of the nonlinear double model are optimized by the federated filter to obtain a better attitude. The proposed algorithm is compared with multisensor complementary filtering (MSCF) and multisensor EKF (MSEKF) using collected flight sensors data. The simulation and experimental tests demonstrate that the proposed algorithm has a good robustness and state estimation solution accuracy.

17.
Materials (Basel) ; 13(2)2020 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-31936643

RESUMEN

Al-Ti-C master alloys have been widely investigated by various researchers. However, their refining effectiveness is still severely compromised by the preparation process. In this work, the aluminum melt in-situ reaction was carried out to synthesize the Al-5Ti-0.62C, and its refining performance was estimated. The thermodynamics calculation and differential scanning calorimeter experiment were used to investigate the synthesis mechanism of TiC. Quenching experiment was conducted to explore phase and microstructure transformation of the Al-5Ti-0.62C system. The results show that the main phases of Al-5Ti-0.62C master alloys are α-Al, Al3Ti, and TiC and it has a positive effect on commercial pure aluminum refining. Commercial pure aluminum is completely refined into the fine equiaxed structure by adding 0.3% Al-5Ti-0.62C master alloy. TiC particles mainly distribute in the grain interior and grain boundaries. The excess Ti came from the dissolution of Al3Ti spreading around TiC and finally forming the Ti-rich zone to promote the nucleation of α-Al. The experiments certified that TiC was formed by the reaction between solid C and excess Ti atoms. The main reactions in the Al-5Ti-0.62C system were that solid Al is transferred into liquid Al, and then liquid Al reacted with solid Ti to form the Al3Ti. At last, the release of a lot of heat promotes the formation of TiC which formed by the Ti atoms and solid C.

18.
J Am Heart Assoc ; 8(16): e011830, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31426686

RESUMEN

Background Pleckstrin homology-like domain family A, member 3 (PHLDA3), a crucial member of the PHLDA family, is involved in tumor suppression, kidney injury, liver injury, and glucose metabolism. However, the role of PHLDA3 in pathological cardiac hypertrophy and heart failure remains unclear. Methods and Results In the present study, PHLDA3 expression was downregulated in hypertrophic murine hearts and angiotensin II-treated cardiomyocytes. Next, an in vitro study suggested, by using gain- and loss-of-function approaches, that PHLDA3 attenuates Ang II exposure-induced cardiomyocyte hypertrophy. Consistent with the cell phenotype, disruption of PHLDA3 aggravated the effects of pressure overload-induced pathological cardiac hypertrophy, fibrosis, and dysfunction. In contrast, PHLDA3 overexpression resulted in an attenuated hypertrophic phenotype. Molecular analysis revealed that PHLDA3 suppressed the activation of AKT-mTOR-GSK3ß-P70S6K signaling in response to hypertrophic stress, and the blockage of AKT activation rescued these adverse pathological effects of PHLDA3 deficiency-induced by AB and Ang II, respectively, in vivo and in vitro. Conclusions Collectively, our data indicated that PHLDA3 could ameliorate pressure overload-induced cardiac remodeling mainly by blocking the AKT signaling pathway, suggesting that PHLDA3 may represent a therapeutic target for the treatment of pathological cardiac hypertrophy and heart failure.


Asunto(s)
Hipertrofia Ventricular Izquierda/genética , Miocitos Cardíacos/metabolismo , Proteínas Nucleares/genética , Remodelación Ventricular/genética , Angiotensina II/farmacología , Animales , Aorta/cirugía , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Humanos , Hipertrofia Ventricular Izquierda/metabolismo , Hipertrofia Ventricular Izquierda/patología , Ratones , Ratones Noqueados , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Transgénicas , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Remodelación Ventricular/efectos de los fármacos
19.
J Am Heart Assoc ; 7(13)2018 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-29945911

RESUMEN

BACKGROUND: Carboxyl-terminal modulator protein (CTMP) has been implicated in cancer, brain injury, and obesity. However, the role of CTMP in pathological cardiac hypertrophy has not been identified. METHODS AND RESULTS: In this study, decreased expression of CTMP was observed in both human failing hearts and murine hypertrophied hearts. To further explore the potential involvement of CTMP in pathological cardiac hypertrophy, cardiac-specific CTMP knockout and overexpression mice were generated. In vivo experiments revealed that CTMP deficiency exacerbated the cardiac hypertrophy, fibrosis, and function induced by pressure overload, whereas CTMP overexpression alleviated the response to hypertrophic stimuli. Consistent with the in vivo results, adenovirus-mediated gain-of-function or loss-of-function experiments showed that CTMP also exerted a protective effect against hypertrophic responses to angiotensin II in vitro. Mechanistically, CTMP ameliorated pathological cardiac hypertrophy through the blockade of the protein kinase B signaling pathway. Moreover, inhibition of protein kinase B activation with LY294002 rescued the deteriorated effect in aortic banding-treated cardiac-specific CTMP knockout mice. CONCLUSIONS: Taken together, these findings imply, for the first time, that increasing the cardiac expression of CTMP may be a novel therapeutic strategy for pathological cardiac hypertrophy.


Asunto(s)
Proteínas Portadoras/metabolismo , Hipertrofia Ventricular Izquierda/prevención & control , Miocitos Cardíacos/enzimología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Función Ventricular Izquierda , Remodelación Ventricular , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Proteínas Portadoras/genética , Células Cultivadas , Modelos Animales de Enfermedad , Fibrosis , Humanos , Hipertrofia Ventricular Izquierda/enzimología , Hipertrofia Ventricular Izquierda/patología , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Proteínas de la Membrana/metabolismo , Ratones Noqueados , Miocitos Cardíacos/patología , Palmitoil-CoA Hidrolasa , Ratas Sprague-Dawley , Transducción de Señal , Tioléster Hidrolasas/metabolismo
20.
J Phys Condens Matter ; 30(18): 185501, 2018 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-29553483

RESUMEN

By doing calculations based on density functional theory, we predict that the two-dimensional anti-ferromagnetic (AFM) NiOsCl6 as a Chern insulator can realize the quantum anomalous Hall (QAH) effect. We investigate the magnetocrystalline anisotropy energies in different magnetic configurations and the Néel AFM configuration is proved to be ground state. When considering spin-orbit coupling (SOC), this layered material with spins perpendicular to the plane shows properties as a Chern insulator characterized by an inversion band structure and a nonzero Chern number. The nontrivial band gap is 37 meV and the Chern number C = -1, which are induced by a strong SOC and AFM order. With strong SOC, the NiOsCl6 system performs a continuous topological phase transition from the Chern insulator to the trivial insulator upon the increasing Coulomb repulsion U. The critical U c is indicated as 0.23 eV, at which the system is in a metallic phase with [Formula: see text]. Upon increasing U, the E g reduces linearly with C = -1 for 0 < U < U c and increases linearly with C = 0 for U > U c . At last we analysis the QAH properties and this continuous topological phase transition theoretically in a two-band [Formula: see text] model. This AFM Chern insulator NiOsCl6 proposes not only a promising way to realize the QAH effect, but also a new material to study the continuous topological phase transition.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...