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A novel bio-based polyamide, poly(pentamethylene oxamide) (PA52), with high molecular weight has been prepared from dibutyl oxalate and renewable monomer of 1,5-pentanediamine by a two-step polymerization procedure. The chemical structures [...]

To modify the properties of poly(hexamethylene oxamide) (PA62), amine‐terminated polyoxypropylene glycols (PGs) were introduced into the polyoxamide main chain as soft segments. A series of PA62/PG2 copolymers were synthesized successfully by a two‐step method. Fourier transform infrared spectroscopy, solution proton nuclear magnetic resonance spectroscopy (1H‐NMR), differential scanning calorimetry, thermogravimetric analysis, and wide‐angle X‐ray diffraction were used to analyze the structures and to investigate the properties of these copolymers. The saturated water absorption was also evaluated by gravimetric analysis for PA62/PG2 copolymers. The results revealed the incorporation of PG2 effectively modified the properties of PA62 and the copolymers with PG2 content of 10–20 mol% possessed high melting point (293°C–314°C), good thermal stability and low saturated water absorption. POLYM. ENG. SCI., 58:1523–1529, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Background: To date, there is limited information on the progression of human infections of avian influenza virus A (H7N9). This study investigated differential blood protein profiling of a H7N9-infected family cluster to find a slice of crucial proteins concerning disease attack and virus clearance.Materials and Methods: Plasma samples from one family cluster (including one index case and one asymptomatic case) were collected at four time points. The protein profiles were identified by isobaric tagging for relative and absolute quantification-based quantitative differential LC/MS/MS, and their functional annotations were analyzed by PANTHER and STRING tools. Results: A total of 1257 nonredundant proteins were identified from 3027 unique peptides. Three differential protein profiles for each subject were generated by comparing relative protein abundance between samples of each of the first three time points and the last time point. Gene ontology analysis indicated that differential protein profiles for the two cases were mainly enriched in the biological processes of response to stimulus, immunity, blood coagulation, lipid transport, and cell adhesion. Two groups of proteins with an upward or downward expression change according to the postinfection time points were detected for each case. STRING analysis further indicated that the hubs in the network of these time-dependent proteins were mostly apolipoproteins. Conclusions: Significant perturbation of the response upon viral infection occurred immediately after confirmation of H7N9 virus infection. The differential protein profiles shed further light on distinguishing the index case from the asymptomatic one. Furthermore, apolipoproteins may play an important role in the progression of the disease. [ABSTRACT FROM AUTHOR]

In this study, an attempt was made to prepare bio-based poly(pentamethylene oxamide) (PA52) using a novel process of spray/solid-state polycondensation. A prepolymer of relative viscosity of 1.3 was prepared by spray polycondensation, where the monomers (dibutyl oxalate and 1,5-pentanediamine) were separately injected into the nozzle, atomized simultaneously under nitrogen flow, mixed, and polymerized at room temperature. After solid-state polycondensation, PA52 with relative viscosity of 3.2, weight-average molecular weight of 4.3 × 10, and melting point of 301 °C was obtained. FTIR and H-NMR analysis confirmed the formation of PA52 while the DSC results suggested that the resultant polymer possessed high heat resistance and good crystallizability. [ABSTRACT FROM AUTHOR]

The prevalence of drought events worldwide emphasizes the importance of screening and cultivating drought-adapted crops. In this study, 206 germplasm resources were used as materials, dry weight as target trait, and two genotyping methods as criteria to evaluate drought adaptability at the seedling establishment stage. The results showed a significant decrease in average dry weight of the tested germplasm resources (from 746.90 mg to 285.40 mg) and rich variation in the responses of dry weight among each genotype to drought (CV=61.14%). In traditional evaluation method, drought resistance coefficient (DC), geometric mean productivity index (GMP), mean productivity index (MP), stress susceptibility index (SSI), stress tolerance index (STI), and tolerance index (TOL) also exhibited diversity in tested genotypes (CV>30%). However, these indices showed varying degrees of explanation for dry weight under stress and non-stress environments and failed to differentiate drought adaptability among genotypes clearly. In new evaluation method, four stress indices were developed to quantify barley seedling production and stability capacities. Compared to traditional stress indices, the stress production index (SI) explained dry weight more comprehensively under stress conditions ( R 2 = 0.98), while the ideal production index (II) explained dry weight better under non-stress conditions ( R 2 = 0.89). Furthermore, the potential index (PI) and elasticity index (EI) eliminated disparities in traditional stress indices and comprehensively clarified the contribution of elasticity and potential to production capacity under drought stress. Ultimately, through grading evaluation and cluster analysis, the tested germplasm resources were effectively categorized, and 11 genotypes were identified as suitable for cultivation in arid areas. Overall, the comprehensive evaluation method based on the newly developed stress indices surpasses the traditional method in screening drought adaptability of crops and serves as a vital tool for identifying high-stability and high-production capacities genotypes in various environments, which is expected to provide practical guidance for barley planting and breeding in arid areas., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Song, Shi, Xiang, He, Dong, Miao and Qi.)