Overview of Polkadot and its Design Considerations

In this paper we describe the design components of the heterogenous multi-chain protocol Polkadot and explain how these components help Polkadot address some of the existing shortcomings of blockchain technologies. At present, a vast number of blockchain projects have been introduced and employed with various features that are not necessarily designed to work with each other. This makes it difficult for users to utilise a large number of applications on different blockchain projects. Moreover, with the increase in number of projects the security that each one is providing individually becomes weaker. Polkadot aims to provide a scalable and interoperable framework for multiple chains with pooled security that is achieved by the collection of components described in this paper

Synthesis of Four Pentacyclic Triterpene–Sialylglycopeptide Conjugates and Their Affinity Assays with Hemagglutinin

Influenza outbreaks pose a serious threat to human health. Hemagglutinin (HA) is an important target for influenza virus entry inhibitors. In this study, we synthesized four pentacyclic triterpene conjugates with a sialylglycopeptide scaffold through the Cu(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) and prepared affinity assays of these conjugates with two HAs, namely H1N1 (A/WSN/1933) and H5N1 (A/Hong Kong/483/97), respectively. With a dissociation constant (KD) of 6.89 μM, SCT-Asn-betulinic acid exhibited the strongest affinity with the H1N1 protein. Furthermore, with a KD value of 9.10 μM, SCT-Asn-oleanolic acid exhibited the strongest affinity with the H5N1 protein. The conjugates considerably enhanced antiviral activity, which indicates that pentacyclic triterpenes can be used as a ligand to improve the anti-influenza ability of the sialylglycopeptide molecule by acting on the HA protein

A New Prenylated Flavanone from Derris trifoliata Lour.

molecule

Characterization of the complete mitogenome of the Hongyuan Yak Bos grunniens (Artiodactyla: Bovidae) and its phylogenetic analysis

The Hongyuan breed Yak (Bos grunniens) belongs to a member of t the subfamily Bovinae. We provide a complete mitogenome of B. grunniens and analyze its phylogenetic relationship with other related species. Its mitogenome is a circular molecule with 16,322 bp in size, including 13 protein coding genes, 22 tRNA genes, 2 rRNA genes, and a non-coding control region (D-loop, CR) that are conserved in most Bovidae mitogenomes. The total base composition of the B. grunniens mitogenome is 33.67% A, 27.29% T, 25.84% C, and 13.20% G. The gene composition, structure and the arrangement for B. grunniens are similar to those of most other Bovidae species. Phylogenetic analysis of mitochondrial genomes of 30 close species with Bayesian inference and maximum likelihood based on 13 protein-coding genes indicated that B. grunniens breed Hongyuan is more closely related to B. grunniens breed Qinghai Plateau than to B. grunniens breed Xuedong and B. grunniens breed Maiwa. The complete mitogenome of B. grunniens breed Hongyuan provides a potentially useful resource for further exploration of the taxonomic status and phylogenetic relationships of Bovinae and related species

Antibacterial Adhesion of Poly(methyl methacrylate) Modified by Borneol Acrylate

Poly­(methyl methacrylate) (PMMA) is a widely used biomaterial. But there is still a challenge facing its unwanted bacterial adhesion because the subsequent biofilm formation usually leads to failure of related implants. Herein, we present a borneol-modified PMMA based on a facile and effective stereochemical strategy, generating antibacterial copolymer named as P­(MMA-<i>co</i>-BA). It was synthesized by free radical polymerization and studied with different ratio between methyl methacrylate (MMA) and borneol acrylate (BA) monomers. NMR, GPC, and EA, etc., were used to confirm their chemical features. Their films were challenged with <i>Escherichia coli</i> (Gram-negative) and <i>Bacillus subtilis</i> (Gram-positive), showing a BA content dependent antibacterial performance. The minimum effective dose should be 10%. Then <i>in vivo</i> subcutaneous implantations in mice demonstrated their biocompatibilities through routine histotomy and HE staining. Therefore, P­(MMA-<i>co</i>-BA)­s not only exhibited their unique antibacterial character but also suggested a potential for the safe usage of borneol-modified PMMA frame and devices for further implantation

Effects of COVID-19 Financial and Social Hardships on Infants’ and Toddlers’ Development in the ECHO Program

Background: The financial hardships and social isolation experienced during the COVID-19 pandemic have been found to adversely affect children’s developmental outcomes. While many studies thus far have focused on school-aged children and the pandemic-related impacts on their academic skills and behavior problems, relatively less is known about pandemic hardships and associations with children’s development during their early years. Using a racially and economically diverse sample, we examined whether hardships experienced during the pandemic were associated with children’s development with a particular focus on communication and socioemotional development. Methods: Participants from eight cohorts of the Environmental influences on Child Health Outcomes program provided data on pandemic-related financial and social hardships as well as child developmental outcomes. Financial hardship was defined as at least one parent experiencing job loss or change, and social hardship was defined as families’ quarantining from household members or extended family and friends. The development of children under 4 was assessed longitudinally, before and during the pandemic (N = 684), using the Ages and Stages Questionnaire (ASQ). The Generalized Estimating Equations, which accounted for within-child correlation, were used for analysis. Results: Families from minority backgrounds and low socioeconomic status disproportionately experienced pandemic-related hardships. Male children had higher odds of experiencing negative changes in communication and personal social skills from pre- to during-pandemic visits (ORs ranged between 2.24 and 3.03 in analysis with binary ASQ outcomes and ranged from −0.34–0.36 in analyses with ASQ z-scores, ps = 0.000). Pandemic-related hardships in the social and financial areas did not explain within-individual changes in children’s developmental outcomes. Conclusion: Negative developmental changes from pre- to during-pandemic were found in boys, yet we did not find any associations between increased experience of pandemic-related hardships and children’s development. E how pandemic hardships affect development using a larger sample size and with longer follow-up is warranted