This paper proposes an adaptive compensation control algorithm for solving the actuator failures problem of nonlinear stochastic multi‐agent systems (MASs) under the directed communication topology. ...It should be emphasized that the coexistence of unknown nonlinearities, stochastic perturbations and actuator failures makes the implementation of control protocol very difficult and extremely challenging. To achieve the control objective, fuzzy logic systems (FLSs) are first employed to deal with the unknown nonlinearities of each agent. Then, the threshold‐based event‐triggered mechanism is further considered to reduce the communication burden of the system in the case of limited communication resources. Moreover, the issue of “explosion of complexity” is solved by using dynamic surface control (DSC) technique in the process of backstepping design. With these efforts, the actuator failures are circumvented and the outputs of the followers converge to the convex hull spanned by the multiple leaders' outputs. Finally, the simulation results of multiple single‐link robots show the validity of the proposed design scheme.
First, the studied stochastic nonlinear MASs consisting of N leaders is considered, in which the dynamics of the leaders can be completely unknowable. Therefore, the leader models can be more general compared to the previous control results 42–46. Moreover, we cleverly apply a novel coordinate transformation to deal with the consensus problem of multi‐leader.
Second, in this paper, the adaptive compensation controller is constructed to effectively compensate the uncertainties of the actuator failure models. In addition, event‐triggered control mechanism for the input of the actuator failure model is used to address the problem of resources transmission limitation.
Third, the proposed communication protocol can ensure that the outputs of the followers converge to the convex hull spanned by the outputs of the multiple leaders. Furthermore, the problem of “explosion of complexity” in the derivation process is solved by fusing the backstepping and DSC technology.
The intermediate filament protein, nestin, is a widely employed marker of multipotent neural stem cells (NSCs). Recent in vitro studies have implicated nestin in a number of cellular processes, but ...there is no data yet on its in vivo function. Here, we report the construction and functional characterization of Nestin knockout mice. We found that these mice show embryonic lethality, with neuroepithelium of the developing neural tube exhibiting significantly fewer NSCs and much higher levels of apoptosis. Consistent with this in vivo observation, NSC cultures derived from knockout embryos show dramatically reduced self‐renewal ability that is associated with elevated apoptosis but no overt defects in cell proliferation or differentiation. Unexpectedly, nestin deficiency has no detectable effect on the integrity of the cytoskeleton. Furthermore, the knockout of Vimentin, which abolishes nestin's ability to polymerize into intermediate filaments in NSCs, does not lead to any apoptotic phenotype. These data demonstrate that nestin is important for the proper survival and self‐renewal of NSCs, and that this function is surprisingly uncoupled from nestin's structural involvement in the cytoskeleton. STEM CELLS 2010;28:2162–2171
Activated B cells contribute to heart diseases, and inhibition of B‐cell activating factor (BAFF) expression is an effective therapeutic target for heart diseases. Whether activated B cells ...participate in the development and progression of hyperthyroid heart disease, and what induces B cells activation in hyperthyroidism are unknown. The present study aimed to determine the roles of BAFF overexpression induced by high concentrations of triiodothyronine (T3) in the pathogenesis of hyperthyroid heart disease. Female C57BL/6J mice were subcutaneously injected with T3 for 6 weeks, and BAFF expression was inhibited using shRNA. Protein and mRNA expression of BAFF in mouse heart tissues evaluated via immunohistochemistry, western blotting and polymerase chain reaction (PCR). Proportions of B cells in mouse cardiac tissue lymphocytes were quantified via flow cytometry. Morphology and left ventricle function were assessed using pathological sections and echocardiography, respectively. Here, we demonstrate that compared with the control group, the proportion of myocardial B cells was larger in the T3 group; immunohistochemistry, western blotting and PCR analyses revealed increased protein and mRNA expression levels of TNF‐α and BAFF in heart tissues of the T3 group. Compared with the normal controls group, in the T3 group, the diameter of myocardial cells and some echocardiographic values significantly increased and hypertrophy and structural disorder were noticeable. Our results revealed that elevated levels of circulating T3 can promote the expression of BAFF in myocardial cells and can lead to B‐cell activation, an elevated inflammatory response and ventricular remodelling.
Abstract
Context
Regulatory T cell (Treg) dysfunction plays an important role in the development and progression of Graves’ disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Treg ...expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined.
Objective
To evaluate the role of PD-1 in Treg function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3.
Methods
We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Treg function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo.
Results
PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Treg function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3.
Conclusion
Treg dysfunction in GD patients might be due to downregulation of PD-1 expression in Tregs induced by high levels of serum T3.
This research was based on the quantum chemical calculations of a set of valid photoswitches of azobenzene compounds, with the aim of describing their thermal isomerization. The influences of ...familiar fluorine substitution and additional electron-donating groups (EDGs) and electron-withdrawing groups (EWGs) on the
-position were also systematically studied. The results show that the presence of fluorine in different
-positions has a distinct effect on the molecular orbital distribution of the
isomer, which realizes the purpose of splitting the n → π* transition between the
and
isomers. On this basis, further
-substitution can allow tunability on the order of the energy level to the molecular orbitals through their influence on the conjugation pattern of the compound. It is the modification of the substituent on these positions that allows the photoisomerization to proceed under visible wavelength light surroundings. The thermal
→
isomerization mechanism has also been analyzed, and a detailed comparison of these compounds has been made with respect to the thermal half-life
, and the rate constants
. The results reveal that isomerization is thought to be a process of globally structural change, during which the effect of the substituents is determined by the extent of their influence on the conjugated system.
Alcoholism is a worldwide health problem, and diseases caused by alcoholism are killing people every year.
is a traditional Chinese medicine used to relieve hangovers. However, whether its bioactive ...components improve alcohol metabolism is not clear. In this study, ten new (amomumols A-J,
-
) and thirty-five known (
-
) compounds were isolated from the fruits of
by an activity-guided separation. Ten novel compounds were identified as four sesquiterpenoids (
-
), three monoterpene derivatives (
-
), two neolignans (
,
), and a novel norsesquiterpenoid (
) with a new C
nor-bisabolane skeleton. Their structures were determined by the comprehensive analysis of high-resolution electrospray ionization mass spectrometry (HRESIMS), nuclear magnetic resonance (NMR), and electronic circular dichroism (ECD) calculation. The effects of all isolated compounds on the activity of alcohol dehydrogenase were evaluated in vitro, and it was found that eight compounds (
,
,
,
,
, and
-
) exhibited significant activation effects on the alcohol dehydrogenase at 50 μM.
Two novel POM-based huge clusters modified by conjugated organic ligands (DAPSC), {Fe10P4W32} and {Fe8MoW18}, have been successfully isolated. Compound 1 consists of a novel huge inorganic building ...block {Fe10P4W32} and four organic groups DAPSC linked by ten iron ions and four sodium ions. The DAPSC ligands enhance the electric delocalization effects of polyoxoanions, leading to strengthening of the third-order nonlinear optical (NLO) responses of compounds 1–2. Additionally, the oxygen evolution reaction (OER) electrocatalytic activity and the magnetic properties of compound 1 have also been investigated.
Two new bifunctional isolated hybrid compounds, ε-PMoV8MoVI4O 37 (OH) 3 Zn 4 iql 4 ·6H 2 O ( 1 ) and ε-PMoV8MoVI4O 38 (OH) 2 Zn 4 bipy 3 (CH 3 COO)(bipy) 2 Zn·2H 2 O ( 2 ) (where iql = isoquinoline ...and bipy = 2,2′-bipyridine), based on Zn-ε-Keggin were successfully synthesized by self-assembly under hydrothermal conditions. It is interesting to note that acetate in 2 acted as a linker connecting the ε-Keggin anion with the one Zn atom (Zn5) and enabled the ε-Keggin anion to coordinate with more bipy ligands, culminating with a larger isolated system, which is the first reported isolated cluster of Zn 5 PMo 12 . Meanwhile, compounds 1–2 show great electrochemical behaviors and excellent electrocatalytic activity for the degradation of NaNO 2 . In addition, compound 2 displays better third-order NLO performance than 1 due to the presence of more conjugated rings, with a TPA cross section ( σ ) of 1819 GM, which suggests that compound 2 has the potential to function as a bifunctional material with tremendous prospects.
This work investigates the adaptive neural tracking control problem for a class of uncertain switched nonlinear non-lower triangular systems with disturbances and dead-zone input. First, radial basis ...function (RBF) neural networks (NNs) serve as a flexible tool to approximate the unknown nonlinear functions. Then during the controller design, the dynamic surface control (DSC) method is used to avoid the issue of “explosion of complexity”, and only one adaptive law is adopted to reduce the computational burden. What’s more, a few classical mathematical approaches are used to handle the design difficulties caused by dead-zone input, and the proposed controller guarantees the closed-loop system signals are semi-globally uniform ultimate boundedness (SGUUB). Finally, a simulation example is given to illustrate the availability of the proposed control scheme.
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