Photocatalytic generation of 1,4-disubstituted 1,2,3-triazoles under metal, oxidant and azide-free conditions

Available online A mild and efficient photocatalytic-induced radical method has been developed for[4+1]cycloaddition reaction of 1,4-disubstituted 1,2,3-triazoles with N-tosylhydrazides and primary amines.The reaction is catalyzed by 20 mol%of I2 under metal,azide and oxidant-free conditions.The method is based upon the photocatalytic generation of allyl-type radicals,followed by the iodine-catalyzed production of azoalkenes,which react rapidly with various anilines.

Neural Stem Cells Transfected with Leukemia Inhibitory Factor Promote Neuroprotection in a Rat Model of Cerebral Ischemia

Leukemia inhibitory factor(LIF) contributes to the neuroprotection by neural stem cells(NSCs) after ischemic stroke. Our aim was to explore whether LIFtransfected NSCs(LIF-NSCs) can ameliorate brain injury and promote neuroprotection in a rat model of cerebral ischemia. To accomplish this goal, we transfected NSCs with a lentivirus carrying the LIF gene to stably overexpress LIF. The LIF-NSCs reduced caspase 3 activation under conditions of oxygen-glucose deprivation in vitro.Transient cerebral ischemia was induced in rats by 2 h of middle cerebral artery occlusion(MCAo), and LIF-NSCs were intravenously injected at 6 h post-ischemia. LIF-NSC treatment reduced the infarction volume and improved neurological recovery. Moreover, LIF-NSCs improved glial cell regeneration and ameliorated white matter injuryin the MCAo rats. The NSCs acted as carriers and increased the expression of LIF in the lesions to protect against cerebral infarction, suggesting that LIF-NSCs could be a potential treatment for cerebral infarction.

Facile preparation of nano-g-C_(3)N_(4)/UiO-66-NH_(2) composite as sorbent for high-efficient extraction and preconcentration of food colorants prior to HPLC analysis

In this work,the nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite was prepared by one-step solvothermal method.The as-prepared composite was characterized by scanning electron microscopy,Brunner-Emmet-Teller measurement,energy dispersive spectrometer,X-ray diffraction,and Fourier transform infrared spectroscopy.By using nano-g-C_(3)N_(4)/Ui O-66-NH_(2)composite as sorbent,a dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed to sensitive analysis of food colorants including tartrazine,amaranth,carmine,sunset yellow,allura red and bright blue.The experiment parameters including the amount of sorbent,adsorption time,the p H of adsorption solution,desorption time,desorption solvent,the p H of desorption solution as well as the proportion between desorption solvent and buffer solvent were investigated.Under the optimized conditions,the limits of detection(S/N=3) and limits of quantitation (S/N=10) were determined in the ranges of 0.08-0.8 and 0.2-2.0 ng/m L,respectively.With the developed sample pretreatment method,carmine and brilliant blue were determined from blueberry juice by HPLC-DAD.The contents were calculated as 1.53μg/m L and0.17μg/mL,respectively.

Monoclonal Antibody-Based Treatments for Neuromyelitis Optica Spectrum Disorders:From Bench to Bedside

Neuromyelitis optica(NMO)/NMO spectrum disorder(NMOSD)is a chronic,recurrent,antibodymediated,inflammatory demyelinating disease of the central nervous system,characterized by optic neuritis and transverse myelitis.The binding of NMO-IgG with astrocytic aquaporin-4(AQP4)functions directly in the pathogenesis of>60%of NMOSD patients,and causes astrocyte loss,secondary inflammatory infiltration,demyelination,and neuron death,potentially leading to paralysis and blindness.Current treatment options,including immunosuppressive agents,plasma exchange,and B-cell depletion,are based on small retrospective case series and open-label studies.It is noteworthy that monoclonal antibody(mAb)therapy is a better option for autoimmune diseases due to its high efficacy and tolerability.Although the pathophysiological mechanisms of NMOSD remain unknown,increasingly,therapeutic studies have focused on mAbs,which target B cell depletion,complement and inflammation cascade inactivation,bloodbrain-barrier protection,and blockade of NMO-IgG-AQP4 binding.Here,we review the targets,characteristics,mechanisms of action,development,and potential efficacy of mAb trials in NMOSD,including preclinical and experimental investigations.

A novel peptide specifically binding to VEGF receptor suppresses angiogenesis in vitro and in vivo

Vascular endothelial growth factor(VEGF),one of the most important angiogenic factors,plays an essential role in both physiological and pathological angiogenesis through binding to VEGF receptors(VEGFRs).Here we report a novel peptide designated HRHTKQRHTALH(peptide HRH),which was isolated from the Ph.D.-12 phage display library using VEGFR-Fc fusion protein as the bait.This peptide was found to dose-dependently inhibit the proliferation of human umbilical vein endothelial cells stimulated by VEGF.The anti-angiogenesis effect of the HRH peptide was further confirmed in vivo using the chick chorioallantoic membrane assay,which was also dose-dependent.Besides,peptide HRH was proved to inhibit corneal neovascularization in an alkali-burnt rat corneal model and a suture-induced rat corneal model.Taken together,these findings suggest that the HRH peptide can inhibit angiogenesis both in vitro and in vivo.Consequently,the HRHTKQRHTALH peptide might be a promising lead peptide for the development of potential angiogenic inhibitors.

Bayesian Network Based Imprecise Probability Estimation Method for Wind Power Ramp Events

Although wind power ramp events(WPREs)are relatively scarce,they can inevitably deteriorate the stability of power system operation and bring risks to the trading of electricity market.In this paper,an imprecise conditional probability estimation method for WPREs is proposed based on the Bayesian network(BN)theory.The method uses the maximum weight spanning tree(MWST)and greedy search(GS)to build a BN that has the highest fitting degree with the observed data.Meanwhile,an extended imprecise Dirichlet model(IDM)is developed to estimate the parameters of the BN,which quantificationally reflect the ambiguous dependencies among the random ramp event and various meteorological variables.The BN is then applied to predict the interval probability of each possible ramp state under the given meteorological conditions,which is expected to cover the target probability at a specified confidence level.The proposed method can quantify the uncertainty of the probabilistic ramp event estimation.Meanwhile,by using the extracted dependencies and Bayesian rules,the method can simplify the conditional probability estimation and perform reliable prediction even with scarce samples.Test results on a real wind farm with three-year operation data illustrate the effectiveness of the proposed method.