Light-emitting materials with tunable properties may offer fascinating applications in optoelectronic devices, fluorescent sensors, and imaging agents. Herein, a new supramolecular approach based on host–guest interactions that greatly decreases the number of required synthetic steps and produces a system with tunable and dynamical photophysical properties was developed. Because of the novel electronic distributions of the chromophore guest within the rigid hydrophobic cavity of the cucurbit[8]uril host in this system, color tuning of emissions such as cyan, yellow, green, and white light with efficiency increased fluorescence lifetime, and quantum yield was easily achieved by simple addition of the host in aqueous solution. Stimulus-responsive tuning of color has long been an important area of research into light emissions. The current study distinguishes itself by its combination of simple steps using a single synthetic receptor and a single organic fluorophore guest in a single solution. Our results may provide a promising advancement of the fabrication of smart and tunable luminescent materials.
Objective To study the effect of 6 formulations of adjuvants on immunoprotection in mice induced by the recombinant Ts87 protein (rTs87) of Trichinella spiralis. Methods ICR mice were vaccinated subcutaneously 3 times in 2-week intervals with rTs87 and different adjuvants CFA or IFA, Montanide IMS1312, Montanide ISA720, Quil-A and AI(OH)3, respectively. The antibody response was detected by ELISA and the purified rTs87 was analyzed by SDS-PAGE and Western blot. The protection induced in mice was then evaluated by muscle larvae reduction after Trichinella spiralis challenge. Results The results clearly showed that all the 6 adjuvants were able to enhance specific anti-rTs87 IgG response. SDS-PAGE and Western blot revealed that the molecular weight of expressed protein was around Mr 40 000 and could be recognized by sera from mice infected with Trichinella spiralis and mice immunized with rTs87. The reduction rate of muscle larvae was 49.4%, 49.2%, 63.5%, 65.1% and 70.8%, respectively. Conclusion Protective immunity of rTs87 can be enhanced by adjuvant CFA or IFA, IMS1312, ISA720, Quil-A and Al(OH)3, and better effect is observed with the latter 3 adjuvants.
Paramyosin is a thick myofibrillar protein found exclusively in invertebrates. Evidence suggested that paramyosin from helminths serves not only as a structural protein but also as an immunomodulatory agent. We previously reported that recombinant Trichinella spiralis paramyosin (Ts-Pmy) elicited a partial protective immunity in mice. In this study, the ability of Ts-Pmy to bind host complement components and protect against host complement attack was investigated.In this study, the transcriptional and protein expression levels of Ts-Pmy were determined in T. spiralis newborn larva (NBL), muscle larva (ML) and adult worm developmental stages by RT-PCR and western blot analysis. Expression of Ts-Pmy at the outer membrane was observed in NBL and adult worms using immunogold electron microscopy and immunofluorescence staining. Functional analysis revealed that recombinant Ts-Pmy(rTs-Pmy) strongly bound to complement components C8 and C9 and inhibited the polymerization of C9 during the formation of the membrane attack complex (MAC). rTs-Pmy also inhibited the lysis of rabbit erythrocytes (E(R)) elicited by an alternative pathway-activated complement from guinea pig serum. Inhibition of native Ts-Pmy on the surface of NBL with a specific antiserum reduced larvae viability when under the attack of complement in vitro. In vivo passive transfer of anti-Ts-Pmy antiserum and complement-treated larvae into mice also significantly reduced the number of larvae that developed to ML.These studies suggest that the outer membrane form of T. spiralis paramyosin plays an important role in the evasion of the host complement attack.
Abstract Background: An unexpected dengue outbreak occurred in Hunan Province in 2018. This was the first dengue outbreak in this area of inland China, and 172 cases were reported. Methods: To verify the causative agent of this outbreak and characterise the viral genes, the genes encoding the structural proteins C/prM/E of viruses isolated from local residents were sequenced followed by mutation and phylogenetic analysis. Recombination, selection pressure, potential secondary structure and three-dimensional structure analyses were also performed. Results: Phylogenetic analysis revealed that all epidemic strains were of the cosmopolitan DENV-2 genotype and were most closely related to the Zhejiang strain (MH010629, 2017) and then the Malaysia strain (KJ806803, 2013). Compared with the sequence of DENV-2SS, 151 base substitutions were found in the sequences of 89 isolates; these substitutions resulted in 20 non-synonymous mutations, of which 17 mutations existed in all samples (two in the capsid protein, six in the prM/M proteins, and nine in the envelope proteins). Moreover, amino acid substitutions at the 602 nd (E322:Q→H) and 670 th (E390: N→S) amino acids may have enhanced the virulence of the epidemic strains. One new DNA binding site and five new protein binding sites were observed. Two polynucleotide binding sites and seven protein binding sites were lost in the epidemic strains compared with DENV-2SS. Meanwhile, five changes were found in helical regions. Minor changes were observed in helical transmembrane and disordered regions. The 429 th amino acid of the E protein switched from a histamine (positively charged) to an asparagine (neutral) in all 89 isolated strains. No recombination events or positive selection pressure sites were observed. To our knowledge, this study is the first to analyse the genetic characteristics of epidemic strains in the first dengue outbreak in Hunan Province in inland China. Conclusions : The causative agent is likely to come from Zhejiang Province, a neighbouring province where dengue fever broke out in 2017. This study may help clarify the intrinsic geographical relatedness of DENV-2 and contribute to further research on pathogenicity and vaccine development.
A sensitive and selective method for the determination of Hg2+ cations by fluorescence enhancement in pure aqueous solution was developed and obtained by simple organic synthesis.
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