Search

AbstractThe uncertainty of thermal protection system (TPS) is inevitable in practical engineering. In this article, the interval finite element model of TPS is established by taking the uncertainties of TPS in thermomechanical coupling analysis as interval parameters. The perturbed-based interval finite element method (PIFEM) and affine-based interval finite element method (AIFEM) are proposed to study the displacement response of uncertain TPS under thermomechanical coupling. Two numerical examples are given and compared with Monte Carlo method (MCM) to verify the effectiveness and accuracy of the PIFEM and AIFEM proposed in this article. The results show that compared with the MCM, the computational efficiency of PIFEM and AIFEM is improved by more than three orders of magnitude, and the computational efficiency of PIFEM and AIFEM is similar. In the case of considering uncertain parameters, the conservative AIFEM is more suitable for the thermomechanical coupled uncertainty analysis of TPS. The numerical results provide useful guidance for TPS design. [ABSTRACT FROM AUTHOR]

Uncertainties are unavoidable in practical engineering, and phononic crystals are no exception. In this paper, the uncertainties are treated as the interval parameters, and an interval phononic crystal beam model is established. A perturbation-based interval finite element method (P-IFEM) and an affine-based interval finite element method (A-IFEM) are proposed to study the dynamic response of this interval phononic crystal beam, based on which an interval vibration transmission analysis can be easily implemented and the safe bandgap can be defined. Finally, two numerical examples are investigated to demonstrate the effectiveness and accuracy of the P-IFEM and A-IFEM. Results show that the safe bandgap range may even decrease by 10% compared with the deterministic bandgap without considering the uncertainties. [ABSTRACT FROM AUTHOR]

In this paper, a novel blind source separation (BSS) method drawing on the framework of Multivariate nonlinear chirp mode decomposition (MNCMD) termed as Nonlinear Chirp Component Analysis (NCCA) is proposed. In contrast to other BSS methods, NCCA is designed to separate the non-stationary sources in an elegant variational optimization framework. Firstly, the source signals are modeled as wide-band nonlinear chirp modes (NCMs) which could be transformed into narrow-band signals with demodulation techniques. Afterwards, the objective function is represented as the summation of source signals bandwidths fulfilling the constraint that the multivariate observed signal is the linear combination of the source signals. Finally, the alternate direction method of multipliers (ADMM) algorithm is employed to solve this optimization problem without more predefined parameters than MNCMD. After that, the source signals including their instantaneous frequency (IF), instantaneous amplitude (IA), the mixing matrix are updated to the optimal values. The merits of NCCA inherited from MNCMD like mode-aligned, filter bank structure, Quasi-orthogonality of modes and its unique attribute of identifying the BSS model and undetermined blind source separation (UBSS) model are testified through a series of synthetic signal. Its anti-noise property and convergence property get verified too. The performance of NCCA in the analysis of vibration analysis through simulation and experimental vibration system is highlighted in the end. [ABSTRACT FROM AUTHOR]

This paper presents an element-by-element-based interval finite-element method (EBE-IFEM) for the uncertain interior acoustic field prediction with uncertain-but-bounded parameters. The interval dynamic matrices and loads vectors are assembled with the element-by-element (EBE) strategy, and decomposed into diagonalization forms additionally. Then the interval dynamic equation can be rewritten as iterative enclosure form, and finally are analyzed by both Rump's method and the Neumaier-Pownuk method in the comparative discussion. Meanwhile, numerical examples are calculated with the interval perturbation finite-element method (IPFEM), modified interval finite-element method (MIPFEM), and Monte Carlo simulation. The numerical results demonstrate that the solution by the EBE-IFEM shows more accurate and more stable than other cross-references, when evaluating the intervals of sound pressure response in interior acoustic field. [ABSTRACT FROM AUTHOR]

Fumonisin B1 (FB1) is the most common species with the highest toxicity among fumonisins. In order to develop a sensitive and simple approach for the detection of FB1 in maize, we designed a new label-free and simple DNA electrochemical aptasensor. Au nanoparticles and graphene oxide (GO) were utilized and chemically modified to amplify the electrochemical signal and afford anchor sites for the modification of recognition probe for FB1. Besides, thionine, an excellent electrochemical indicator, was conjugated on GO–Au complex surface based on the π–π interaction between thionine and GO. To measure FB1 with high specificity and decrease the interference signal produced in real sample measurement, its aptamer was functionalized on Au particle surface via Au−S bond. The proposed biosensor demonstrates a wide linear range between 1 × 10–11 to 1 × 10–4 g/mL with a low detection limit of 10 pg/mL. Importantly, it exhibits acceptable practicability and good stability in real sample detection. [ABSTRACT FROM AUTHOR]

In this study, an integrated analytical and experimental study on a type of one-dimensional periodic acoustic metamaterial with mass-in-mass unit cells is presented. Then, this paper proposes an antioptimization strategy to study the effect of the design parameters of the local resonators of the mass-in-mass acoustic metamaterial model on the band gap behavior. In this antioptimization strategy, the interval model is used to deal with the inner mass, spring stiffness and damping coefficient of the local resonators, and an interval mass-in-mass acoustic metamaterial model is established. Both the rational series expansion-interval perturbation finite element method (RSE-IPFEM) and interval affine finite element method (IAFEM) are used to evaluate the lower and upper bounds of the dynamic response interval vector, based on which an interval vibration transmission analysis can be implemented. Meanwhile, Monte Carlo method and experiments are also presented to demonstrate the efficiency and accuracy of the RSE-IPFEM and IAFEM. Results show that the design parameters of the local resonators significantly affect the beginning frequency of the band gap. Compared with the traditional optimization algorithm, the calculation accuracy of the antioptimization algorithm based on RSE-IPFEM and IAFEM can meet the engineering requirements, and the calculation efficiency is also significantly improved. Since IAFEM is more effective than RSE-IPFEM in suppressing conservatism, IAFEM is a better antioptimization strategy for dealing with the interval mass-in-mass acoustic metamaterial model. Therefore, the proposed antioptimization scheme is expected to inspire future researchers to analyze regulation rules of the band gap following the same procedures. [ABSTRACT FROM AUTHOR]

Instantaneous modal parameter identification of time-varying dynamic systems is a useful but challenging task, especially in the identification of damping ratio. This paper presents a method for modal parameter identification of linear time-varying systems by combining adaptive time-frequency decomposition and signal energy analysis. In this framework, the adaptive linear chirplet transform is applied in time-frequency analysis of acceleration response for its higher energy concentration, and the response of each mode can be adaptively decomposed via an adaptive Kalman filter. Then, the damping ratio of the time-varying systems is identified based on energy analysis of component response signal. The proposed method can not only improve the accuracy of instantaneous frequency extraction but also ensure the antinoise ability in identifying the damping ratio. The efficiency of the method is first verified through a numerical simulation of a three-degree-of-freedom time-varying structure. Then, the method is demonstrated by comparing with the traditional wavelet and time-domain peak method. The identified results illustrate that the proposed method can obtain more accurate modal parameters in low signal-to-noise ratio (SNR) scenarios. [ABSTRACT FROM AUTHOR]

Applying nonlocal elasticity theory, von Kármán type nonlinear strain-displacement relation and plane wave expansion (PWE) method to Euler-Bernoulli beam, the calculation method of band structure of a nonlinear nonlocal piezoelectric phononic crystal (PC) nanobeam is proposed and formulized. In order to investigate the properties of wave propagating in the nanobeam in detail, band gaps of first four orders are picked, and the corresponding influence rules of electro-mechanical coupling fields, nonlocal effect and geometric parameters on band gaps are studied. During the researches, external electrical voltage and axial force are chosen as the influencing parameters related to electro-mechanical coupling fields. Scale coefficient is chosen as the influencing parameter corresponding to nonlocal effect. Length ratio between materials PZT-4 and epoxy and height-width ratio are chosen as the influencing parameters of geometric parameters. Moreover, all the influence rules are compared to those in linear nanobeam. The results are expected to be of help for the design of micro and nano devices based on piezoelectric periodic nanobeam. • A nonlocal piezoelectric phononic crystal nanobeam is proposed. • The band structure with nonlocal effect and nonlinearity considered is calculated by plane wave expansion method. • Influences of electro-mechanical coupling fields, nonlocal effect and geometric parameters on band gaps are revealed. • All the influence rules in nonlinear nanobeam are compared to those in linear nanobeam. [ABSTRACT FROM AUTHOR]

This paper develops a unified and efficient simulation technique based on the scaled boundary finite element method (SBFEM) for transient structural–acoustic problems in two dimensions. The structural component can be an assembly of thin to moderately thick unidirectional plates. Each of them is treated as a plane strain problem and the principle of virtual work involving the inertial contribution is applied to derive the scaled boundary finite element equation. Only the longitudinal dimension is discretized with line elements and the solution through the thickness is expressed analytically as a Padé expansion. A variable transformation process together with certain structural assumptions leads to the static stiffness and mass matrices. The acoustic field can be a semi-infinite region, which is first divided by an artificial boundary into a near field and an exterior domain. The former is analyzed using the improved continued-fraction approach and the latter is modeled by the improved doubly-asymptotic open boundary. These formulations are based on velocity potential and established consistently in the SBFEM framework. High-order spectral elements are employed for both the structural and acoustic domains, to which independent discretization schemes are applied. Numerical examples are presented to demonstrate the excellent performances of the proposed technique. [ABSTRACT FROM AUTHOR]

This paper extends the traditional plane wave expansion (PWE) method to calculate the band structure of the proposed simplified model of composite locally resonant phononic crystal (LRPC) plate. Explicit matrix formulations are developed for the calculation of band structure. In order to illustrate the accuracy of the results, the band structure calculated by PWE method is compared to that calculated by finite element (FE) method. In addition, in order to reveal the bandgap properties, band structures of the “spring–mass” simplified model of stubbed-on LRPC plate, “spring–torsional spring–mass” simplified model of stubbed-on LRPC plate and “spring–torsional spring–mass” simplified model of composite LRPC plate with and without the viscidity considered are presented and investigated in detail. [ABSTRACT FROM AUTHOR]

This paper couples the plane wave expansion (PWE) and finite element (FE) methods to calculate the band structures of the semi-infinite beam-like phononic crystals (PCs) with the infinite periodicity in z -direction and finiteness in x – y plane. Explicit matrix formulations are developed for the calculation of band structures. In order to illustrate the applicability and accuracy of the proposed coupled plane wave expansion and finite element (PWE/FE) method to beam-like PCs, several examples are displayed. At first, PWE/FE method is applied to calculate the band structures of the Pb/rubber beam-like PCs with circular and rectangular cross sections, respectively. Then, it is used to calculate the band structures of steel/epoxy and steel/aluminum beam-like PCs with the same geometric parameters. Last, the band structure of the three-component beam-like PC is also calculated by the proposed method. Moreover, all the results calculated by PWE/FE method are compared with those calculated by finite element (FE) method, and the corresponding results are in good agreement. [ABSTRACT FROM AUTHOR]

Bandgap properties of the locally resonant phononic crystal double panel structure made of a two-dimensional periodic array of a spring–mass resonator surrounded by n springs ( n equals to zero at the beginning of the study) connected between the upper and lower plates are investigated in this paper. The finite element method is applied to calculate the band structure, of which the accuracy is confirmed in comparison with the one calculated by the extended plane wave expansion (PWE) method and the transmission spectrum. Numerical results and further analysis demonstrate that two bands corresponding to the antisymmetric vibration mode open a wide band gap but is cut narrower by a band corresponding to the symmetric mode. One of the regulation rules shows that the lowest frequency on the symmetric mode band is proportional to the spring stiffness. Then, a new design idea of adding springs around the resonator in a unit cell ( n is not equal to zero now) is proposed in the need of widening the bandwidth and lowering the starting frequency. Results show that the bandwidth of the band gap increases from 50 Hz to nearly 200 Hz. By introducing the quality factor, the regulation rules with the comprehensive consideration of the whole structure quality limitation, the wide band gap and the low starting frequency are also discussed. [ABSTRACT FROM AUTHOR]

This paper investigates the band gap (BG) characteristic of a two-dimensional square spiral locally resonant phononic crystal, and a BG optimization scheme is proposed. First, the influence of three structural parameters (the side length of scatterer, the thickness of elastic beams and the number of square rings) on BGs are studied. Meanwhile, the BG formation mechanism is analyzed by studying the displacement fields of the eigenmodes at the BG boundaries. Second, a 7-level numerical experiment of 3-parameter is designed. The finite element method is employed to analysis the start frequency of the first BG and the total width of the first two BGs, which are expressed as regression equations through response surface method. Finally, the optimal structural parameters with low-frequency broadband characteristic are calculated by interior point method. The numerical results are in good agreement with the calculation results, which show the effectiveness of the optimization scheme. • A novel phononic crystal (PC) that can open the band gaps below 100 Hz is proposed. • A novel band bag (BG) optimization scheme for two-dimension PC is proposed. • The effect of structural parameters on BG is revealed by response surface method. • The performance of the optimization scheme is validated by numerical simulations. [ABSTRACT FROM AUTHOR]

• Band structure of metamaterial dual-beam includes symmetric and antisymmetric band. • A narrow flexural bandgap can be formed below 100 Hz. • Vibration isolation effect of metamaterial dual-beam is better than CMB. • High-static-low-dynamic stiffness (HSLDS) resonator can widen the bandgap. In this paper, a metamaterial dual-beam structure is firstly constructed by periodically adding pillars between two identical homogeneous beams. By simplifying the pillar as an equivalent spring-mass-spring system, another metamaterial dual-beam structure carrying periodic spring-mass-spring resonators is then established. This equivalent representation method is validated through both a vibration transmission analysis and a band structure analysis. Two bands corresponding to the antisymmetric and symmetric flexural vibration modes respectively open a flexural narrow bandgap in the low frequency range. Then, the improved structure with high-static-low-dynamic stiffness (HSLDS) resonators is proposed in the need of widening the bandgap and lowering the beginning frequency. Results show that with the decrease of the proportion of the residual stiffness, the beginning frequency of the bandgap can be reduced, while the ending frequency keeps unchanged. This results in a relative bandgap as high as 1.465, which is about 4.4 times of the original structure. [ABSTRACT FROM AUTHOR]

Getah virus (GETV) is a re-emerging mosquito-borne alphavirus that is highly pathogenic, mainly to pigs and horses. There are no vaccines or treatments available for GETV in swine in China. Therefore, the development of a simple, rapid, specific, and sensitive serological assay for GETV antibodies is essential for the prevention and control of GETV. Current antibody monitoring methods are time-consuming, expensive, and dependent on specialized instrumentation, and these features are not conducive to rapid detection in clinical samples. To address these problem, we developed immunochromatographic test strips (ICTS) using eukaryotically expressed soluble recombinant p62-E1 protein of GETV as a labelled antigen, which has good detection sensitivity and no cross-reactivity with other common porcine virus-positive sera. The ICTS is highly compatible with IFA and ELISA and can be stored for 1 month at 37 °C and for at least 3 months at room temperature. Hence, p62-E1-based ICTS is a rapid, accurate, and convenient method for rapid on-site detection of GETV antibodies. Key points: • We established a rapid antibody detection method that can monitor GETV infection • We developed colloidal gold test strips with high sensitivity and specificity • The development of colloidal gold test strips will aid in the field serologic detection of GETV [ABSTRACT FROM AUTHOR]

• The concept of normal scaling strategy is proposed for the first time. • A novel shell formulation based on the SBFEM is presented. • A unified SBFEM for transient vibro-acoustic analysis of plates and shells is developed. • The structural and acoustic domains are discretized independently. • The validity and performance of the proposed methodology are demonstrated. This paper develops an efficient modeling technique based on the scaled boundary finite element method (SBFEM) for transient vibro-acoustic analysis of plates and shells. For simulating the structural dynamic behaviors, a novel shell formulation based on three-dimensional linear elastic theory is presented where only the bottom surface of the shell is discretized with finite elements while the solution along the thickness is expressed analytically as a Padé expansion. A new scaling idea named normal scaling strategy is introduced to enable the formulation to be applicable to geometrically arbitrary shells. The acoustic field is assumed to be infinite and first truncated by a spherical surface into an interior finite region and an exterior unbounded region. The former is further split into a number of bounded subdomains which are analyzed by the improved continued-fraction approach while the latter is simulated by the improved high-order doubly-asymptotic open boundary. These formulations are consistently constructed within the SBFEM framework. The structural and acoustic domains are discretized independently and a simple and reliable coupling scheme is devised. The Bathe time integration method is employed to perform the transient analysis. Numerical examples are presented to demonstrate the validity and performance of the proposed methodology. [ABSTRACT FROM AUTHOR]

Ventricular remodeling is one of the main causes of mortality from heart failure due to hypertension. Exploring its mechanism and finding therapeutic targets have become urgent scientific problems to be solved. A number of studies have shown that Mas, as an Ang-(1-7) specific receptor, was significantly reduced in myocardial tissue of rats undergoing hypertensive ventricular remodeling. It has been reported that Mas receptor levels are significantly downregulated in myocardium undergoing ventricular remodeling, but studies focused on intracellular and post-translational modifications of Mas are lacking. The results of this research are as follows: (1) PDZK1 interacts with the carboxyl terminus of Mas through its PDZ1 domain; (2) the expression of PDZK1 and Mas is decreased in rats undergoing hypertensive ventricular remodeling, and PDZK1 upregulation can ameliorate hypertensive myocardial fibrosis and myocardial hypertrophy; (3) PDZK1 enhances the stability of Mas protein through the proteasome pathway, and the proteasome inhibitor MG132 promotes hypertensive ventricular remodeling. PDZK1 improves ventricular remodeling in hypertensive rats by regulating Mas receptor stability. This study provides a scientific basis for the prevention and treatment of ventricular remodeling. [ABSTRACT FROM AUTHOR]

Influenza A viruses (IAV) modulate host antiviral responses to promote viral growth and pathogenicity. The non-structural (NS1) protein of influenza A virus has played an indispensable role in the inhibition of host immune responses, especially in limiting interferon (IFN) production. In this study, random site mutations were introduced into the NS1 gene of A/WSN/1933 (WSN, H1N1) via an error prone PCR to construct a random mutant plasmid library. The NS1 random mutant virus library was generated by reverse genetics. To screen out the unidentified NS1 functional mutants, the library viruses were lung-to-lung passaged in mice and individual plaques were picked from the fourth passage in mice lungs. Sanger sequencing revealed that eight different kinds of mutations in the NS1 gene were obtained from the passaged library virus. We found that the NS1 F9Y mutation significantly enhanced viral growth in vitro (MDCK and A549 cells) and in vivo (BALB/c mice) as well as increased virulence in mice. The NS1 D2I mutation attenuated the viral replication and pathogenicity in both in vitro and in vivo models. Further studies demonstrated that the NS1 F9Y mutant virus exhibited systematic and selective inhibition of cytokine responses as well as inhibited the expression of IFN. In addition, the expression levels of innate immunity-related cytokines were significantly up-regulated after the rNS1 D2I virus infected A549 cells. Collectively, our results revealed that the two mutations in the N-terminal of the NS1 protein could alter the viral properties of IAV and provide additional evidence that the NS1 protein is a critical virulence factor. The two characterized NS1 mutations may serve as potential targets for antiviral drugs as well as attenuated vaccine development. [ABSTRACT FROM AUTHOR]

Abstract: Deoxynivalenol (DON), known colloquially as “vomitoxin”, is a pathogenic mycotoxin produced by Fusarium fungi. Human food poisoning outbreaks, with nausea, diarrhea, and vomiting as primary symptoms, have been associated with Fusarium-infected cereals. Therefore, this study was designed to determine the molecular aspects of DON in human colon cancer cells (HT-29). To this aim, we have monitored the effects of DON on (i) cellular morphological changes via optical and transmission electron microscopy, especially in regards to cell viability and mitochondria changes, and (ii) its effects on key regulators of cell apoptosis, including cytochrome c, caspase-9, caspase-3, Bcl-2, Bax, and Bid. Our results showed that DON treatment inhibited cell proliferation, induced significant morphological changes, and promoted the activation of cytochrome c and caspases. Furthermore, changes in Bcl-2, Bax, and Bid expression were detected. The relative expression profile of Bcl-2 was contrary to that of Bax and Bid, as Bcl-2 expression decreased as the concentrations DON increased, reaching a minimum at the highest concentration of DON. We concluded that DON-induced apoptosis was caused by mitochondrial dysfunction and subsequent release of cytochrome c into the cytoplasm and successive activation of caspases, and this was likely regulated by Bcl-2 family proteins. [Copyright &y& Elsevier]

l-cystine and l-cysteine have been intercalated into magnesium–aluminum layered double hydroxide by the methods of coprecipitation and ion-exchange. The structure and composition of the intercalated materials have been characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and elemental analysis. For l-cysteine intercalated composites, two kinds of well-crystallized materials with different basal spacing were obtained, as a result of the different charge on an ion and orientation of the gallery anions. The schematic models of the intercalation structures were proposed. In addition, the thermal decomposition of l-cystine and l-cysteine intercalated LDHs has been investigated by means of thermogravimetry and differential thermal analysis (TG-DTA). [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that the NLRP3 (nucleotide oligomerization domain-like receptor family, pyrin domain containing 3) inflammasome participates in cardiovascular diseases. However, its role and activation mechanism during hypertension remains unclear. In this study, we tested the role and mechanism of calcium-sensing receptor (CaSR) in NLRP3 inflammasome activation during hypertension. We observed that the expressions of CaSR and NLRP3 were increased in spontaneous hypertensive rats (SHRs) along with aortic fibrosis. In vascular smooth muscle cells (VSMCs), the activation of NLRP3 inflammasome associated with CaSR and collagen synthesis was induced by angiotensin II (Ang II). Furthermore, inhibition of CaSR and NLRP3 inflammasome attenuated proinflammatory cytokine release, suggesting that CaSR-mediated activation of the NLRP3 inflammasome may be a therapeutic target in aortic dysfunction and vascular inflammatory lesions. [ABSTRACT FROM AUTHOR]

Cyclosporin A (CsA) is an effective immunosuppressive agent, but its myocardial toxicity limits its widespread and long-term clinical application. In this study, CsA treatment led to damages in myocardial fiber structure, an increase in myocardial fibrosis, and changes in heart size and shape; moreover, the degree of damage was exacerbated with prolonged drug application and increases in dose. However, the mechanism is not clear; therefore, the purpose of this study was to reveal the mechanism of CsA-induced myocardial fibrosis and identify a new target for the prevention and treatment of CsA-induced myocardial injury. Cardiac fibroblasts were treated with CsA (5, 10, or 20 μg/mL) for 24 h. Autophagy was observed by electron microscopy and immunofluorescence. The expression of NRP-2/WDFY-1, autophagy-related proteins (Beclin1 and LC3B), fibrosis-related proteins (MMP2/9), and fibroblast phenotype conversion factor (α-SMA) was evaluated by Western blot. The expression of collagen I was determined by ELISA. Then, we used the gene interference technique to alter WDFY-1 expression with or without CsA or 3-MA treatment for 24 h, and the effects on autophagy and the expression of autophagy-related proteins, fibrosis-associated proteins, IFN-α, TNF-α, and IL-6 were determined. The results showed the following: (1) CsA induced fibrosis-related protein (MMP2/9), fibroblast phenotype conversion factor (α-SMA), and collagen I up-regulation in a dose-dependent manner. (2) CsA induced the formation of autophagosomes and up-regulated the expression of Beclin1, LC3B, and the ERK/MAPK pathway in cardiac fibroblasts. (3) CsA induced NRP-2 down-regulation and WDFY-1 up-regulation. (4) Depletion of WDFY-1 inhibited CsA-induced autophagy, TNF-α and IFN-α up-regulation, and fibrosis. (5) The autophagy inhibitor 3-MA inhibited CsA-induced TNF-α and IFN-α up-regulation and fibrosis. Overall, cyclosporin A induces autophagy in cardiac fibroblasts through the NRP-2/WDFY-1 axis, which promotes the progression of myocardial fibrosis. [ABSTRACT FROM AUTHOR]

Cardiac fibrosis is one of the primary mechanisms of ventricular remodeling, and there is no effective method for reversal. Activation of calcium sensing receptor (CaSR) has been reported to be involved in the development of myocardial fibrosis, but the molecular mechanism for CaSR activation has not yet been clarified and needs to be further explored. Here, we found that AngII induces cardiac fibroblast proliferation and phenotypic transformation in a dose-dependent manner with increased CaSR and autophagy related protein (Beclin1, LC3B) expression. CaSR activation results in intracellular calcium release, MEK1/2 pathway phosphorylation, autophagy activation and collagen formation induced by AngII in cardiac fibroblasts. However, pretreating the cells with Calhex 231 , PD98059 or 3-MA partially blocked AngII-induced cardiac fibrosis. Our data indicate that the activation of CaSR-mediated MEK/ERK and autophagic pathways is involved in AngII-induced cardiac fibrosis in vitro. [ABSTRACT FROM AUTHOR]

Hyperproliferation of vascular smooth muscle cells (VSMC) is a major risk factor for cardiovascular diseases. Proper mitochondrial fission and fusion is involved with VSMC function. However, the role and mechanism of mitochondrial morphological changes in VSMC proliferation are not well understood. Here, we found that calcium sensing receptor (CaSR) was increased in the aortas from spontaneous hypertensive rats (SHRs) compared with age-matched Wistar Kyoto (WKY) rats. There was also an increase in mitochondrial fission and VSMC proliferation, which was attenuated by Calhex231. In primary rat VMSC, angiotensin II (Ang II) stimulation induced cytosolic [Ca 2+ ] i increase, mitochondrial shortening and proliferation, all of which could be attenuated by pretreatment with mitochondrial division inhibitor-1 (Mdivi-1) and Calhex231. Our data indicate that CaSR-mediated mitochondrial fission could be a therapeutic target for hyperproliferative disorders. [ABSTRACT FROM AUTHOR]

Stimulator of interferon gene (STING) plays an important role in the cyclic GMP-AMP synthase (cGAS)-mediated activation of type I IFN responses. In this study, we identified and cloned canine STING gene. Full-length STING encodes a 375 amino acid product that shares the highest similarity with feline STING. Highest levels of mRNA of canine STING were detected in the spleen and lungs while the lowest levels in the heart and muscle. Analysis of its cellular localization showed that STING is localizes to the endoplasmic reticulum. STING overexpression induced the IFN response via the IRF3 and NF-κB pathways and up-regulated the expression of ISG15 and viperin. However, knockdown of STING did not inhibit the IFN-β response triggered by poly(dA:dT), poly(I:C), or SeV. Finally, overexpression of STING significantly inhibited the replication of canine influenza virus H3N2. Collectively, our findings indicate that STING is involved in the regulation of the IFN-β pathway in canine. [ABSTRACT FROM AUTHOR]

Calcium sensing receptor (CaSR) mediates pathological cardiac hypertrophy. Mitochondria maintain their function through fission and fusion and disruption of mitochondrial dynamic is linked to various cardiac diseases. This study examined how inhibition of CaSR by the inhibitor Calhex 231 affected the mitochondrial dynamics in a hypertensive model in rats. Spontaneously hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats were used in this study. Cardiac function and blood pressure was evaluated at the end of the study. SHRs showed increases in the ratio of heart weight to body weight and the levels of CaSR; all of these increases were suppressed by Calhex 231 . Additionally, Calhex 231 treatment of SHRs changed the expression of proteins involved in mitochondrial dynamics. Our results demonstrated that CaSR activation induced cardiomyocyte apoptosis through the mitochondrial dynamics mediated apoptotic pathway in hypertensive hearts. [ABSTRACT FROM AUTHOR]

The goal of the present study was to investigate the immune-enhancing activity of polysaccharides from Cyrtomium macrophyllum (CMP). Two experiments were carried out. In immunosuppression experiment, the immune-enhancing effect of CMP in immunosuppressive mice was performed. The results showed that CMP at high and medium doses was able to overcome the CY-induced immunosuppression, significantly increases the thymus and spleen indices, enhances lymphocyte proliferation activity and macrophage function, improves immunoglobulin and cytokines levels compared with negative control group. In macrophage immunomodulatory experiment, the immune-enhancing effect of CMP in RAW264.7 cells was measured. The results showed that CMP induced the elevation of NO production, TNF-α secretion and iNOS protein of RAW264.7 cells. CMP can also strongly increase NF-κB levels in nuclear, which is an important transcription factor that can modulate expressions of iNOS, NO and TNF-α. Therefore, the CMP could be an effective immunomodulatory agent. [ABSTRACT FROM AUTHOR]

Vascular smooth muscle cell (VSMC) proliferation plays a significant role in the development of various vascular disorders. However, the effect of cortistatin (CST) on VSMC proliferation remains unclear. Therefore, the purpose of our research aimed to study whether CST protected VSMCs from angiotensin II (Ang II)-induced proliferation and which mechanisms participated in the process. Cultured rat VSMCs were treated with Ang II with or without CST for 24 h. Cell proliferation rate was measured by cell counting kit-8 (CCK8) assay. The expressions of CST and its receptors were assessed by quantitative real-time PCR (qRT-PCR). The protein expression levels were analyzed by western blots. Immunofluorescence and transmission electron microscopy (TEM) were used to observe autophagy. Our results showed that different concentrations of CST alleviated the Ang II-induced VSMC proliferation. The autophagy and reactive oxygen species (ROS) stimulated by Ang II were attenuated by CST. Furthermore, when the autophagy inhibitor 3-methyladenine (3-MA) was added, it exerted similar inhibition effects like CST, but didn't augment the protective role of CST on Ang II-induced VSMC autophagy and proliferation. Moreover, blocking somatostatin receptor 3 and 5 (SSTR3 and SSTR5) partially abrogated the suppressive effect of CST on Ang II-stimulated VSMC proliferation and autophagy. This study indicated that CST could ameliorate Ang II-stimulated VSMC proliferation by inhibiting autophagy partially through its receptors SSTR3 and SSTR5, providing a reasonable evidence for CST as a novel perspective therapeutic target of vascular diseases. [ABSTRACT FROM AUTHOR]

Background: Infectious bronchitis (IB) caused by the IB virus (IBV) can cause acute damage to chickens around the world. Therefore, rapid diagnosis and immune status determination are critical for controlling IBV outbreaks. Enzyme-linked immunosorbent assays (ELISAs) have been widely used in the detection of IBV antibodies in the early infection and continuous infection of IB because they are more sensitive and quicker than other diagnostic methods. Results: We have developed two indirect microarray methods to detect antibodies against IBV: a chemiluminescent immunoassay test (CIT) and a rapid diagnostic test (RDT). IBV nonstructural protein 5 (nsp5) was expressed, purified from Escherichia coli, and used to spot the initiator integrated poly(dimethylsiloxane), which can provide a near "zero" background for serological assays. Compared with the IDEXX IBV Ab Test kit, CIT and RDT have a sensitivity and specificity of at least 98.88% and 91.67%, respectively. No cross-reaction was detected with antibodies against avian influenza virus subtypes (H5, H7, and H9), Newcastle disease virus, Marek's disease virus, infectious bursal disease virus, and chicken anemia virus. The coefficients of variation of the reproducibility of the intra- and inter-assays for CIT ranged from 0.8 to 18.63%. The reproducibility of RDT was consistent with the original results. The application of the IBV nsp5 protein microarray showed that the positive rate of the CIT was 96.77%, that of the nsp5 ELISA was 91.40%, and that of the RDT was 90.32%. Furthermore, the RDT, which was visible to the naked eye, could be completed within 15 min. Our results indicated that compared with nsp5 ELISA, the CIT was more sensitive, and the RDT had similar positive rates but was faster. Furthermore, the two proposed methods were specific and stable. Conclusions: Two microarray assays, which were rapid, specific, sensitive, and relatively simple, were developed for the detection of an antibody against IBV. These methods can be of great value for the surveillance of pathogens and monitoring the efficiency of vaccination. [ABSTRACT FROM AUTHOR]