Engineered polymer nanoparticles incorporating L-amino acid groups as affinity reagents for fibrinogen

Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid monomers.Five kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive charges.After incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and HSA.Additionally,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between them.The specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein mixture.AArg@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.

Nontoxic chemical crosslinked bacterial cellulose-heparin-gelatin composite hydrogel as antibacterial dressing

A hydrogel dressing based on bacterial cellulose(BC),which is grafted with quaternary ammonium func-tional and crosslinked with the gelatin-heparin system,is prepared to provide the features mainly con-cerning softness,high swelling ratio,antibacterial property,and biocompatibility.An innovation of prepa-ration is that the BC is beaten into short-chain scaffolds to improve the efficiency of grafting,which not only simplifies the preparation process but also avoids the biotoxicity caused by the introduction of toxic catalyst such as dimethyl sulfoxide(DMSO)or uncertain toxic side products in long-chain graft-ing.Scanning electron microscopy(SEM)shows that the QBC/Hep/Gel composite hydrogel possesses a three-dimensional mesh structure with high porosity.The hydrogel shows outstanding water manage-ment performance indicated by the swelling ratio of 1476%,water retention ratio of more than 90%at 120 h,and moisture permeability of 3296 g m^(-2) 24 h^(-1).The antibacterial experiment is implemented with staphylococcus aureus,and the antibacterial effect is represented by an inhibition zone of 3 cm in diameter.In vivo animal experiments suggested that QBC/Hep/Gel could effectively promote epithelial reconstruction,collagen deposition,and angiogenesis in normal wounds,reduce inflammation,and ac-celerate wound healing.All these results indicate that the proposed QBC/Hep/Gel hydrogel is a potential composite for antibacterial dressing.

Efficient protocols for heavy hitter identification with local differential privacy

Local differential privacy(LDP),which is a technique that employs unbiased statistical estimations instead of real data,is usually adopted in data collection,as it can protect every user’s privacy and prevent the leakage of sensitive information.The segment pairs method(SPM),multiple-channel method(MCM)and prefix extending method(PEM)are three known LDP protocols for heavy hitter identification as well as the frequency oracle(FO)problem with large domains.However,the low scalability of these three LDP algorithms often limits their application.Specifically,communication and computation strongly affect their efficiency.Moreover,excessive grouping or sharing of privacy budgets makes the results inaccurate.To address the abovementioned problems,this study proposes independent channel(IC)and mixed independent channel(MIC),which are efficient LDP protocols for FO with a large domains.We design a flexible method for splitting a large domain to reduce the number of sub-domains.Further,we employ the false positive rate with interaction to obtain an accurate estimation.Numerical experiments demonstrate that IC outperforms all the existing solutions under the same privacy guarantee while MIC performs well under a small privacy budget with the lowest communication cost.

Inference for Optimal Split Point in Conditional Quantiles

In this paper we show the occurrence of cubic-root asymptotics in misspecified conditional quantile models where the approximating functions are restricted to be binary decision trees. Inference procedure for the optimal split point in the decision tree is conducted by inverting a t-test or a deviation measure test, both involving Chemoff type limiting distributions. In order to avoid estimating the nuisance parameters in the complicated limiting distribution, subsampling is proved to deliver the correct confidence interval/set.