Surface free energy and mechanical performance of LDPE/CBF composites containing toxic-metal free filler

Heavy-metal contamination in children's toys is a widespread problem, and the international community has issued a series of safety standards to restrict and control the use of toxic metals in toys. In this work, a colored filler (CBF) was prepared using pearl oyster shell (POS) as the green raw material and azo dye as the colorant. Its surface properties were subsequently studied in comparison to those of POS powder using the inverse gas chromatography method. The dispersion surface free energy profiles for both CBF and POS showed that this component contributed the major part (> 70%) to the total surface free energy. The CBF possessed lower polar surface free energy and was relatively more hydrophobic. It also showed a lower thermodynamic work of cohesion, allowing its better dispersion in a low density polyethylene (LDPE) matrix. Mechanical performance studies showed that adding CBF could significantly increase the tensile strength, elastic modulus, flexural strength and flexural modulus of LDPE composites. The absence of toxic metals coupled with excellent mechanical performance makes the CBF an ideal candidate as a filler for children's toys fabrication.The authors gratefully acknowledge financial support from the National Natural Science Foundation of China (Grant nos. 51606055 and 41373121) and Zhejiang Provincial Natural Science Foundation of China (Grant no. LY14D010009).info:eu-repo/semantics/publishedVersio

Adsorption of Congo red from aqueous solution onto shrimp shell powder

Two novel adsorbents derived from shrimp shell were prepared and their adsorption performances on Congo red were investigated. The results suggested that treated shrimp shell powder exhibited a higher adsorption capacity than raw shrimp shell powder. The factors of initial concentration, solution pH, adsorption time, and temperature were investigated. The maximum adsorption capacity of treated shrimp shell powder calculated according to the Langmuir isotherm model was 288.2 mg/g, which is much higher than that of chitin. The adsorption behavior could be fitted well by the pseudo-second-order kinetic model. Intra-particle diffusion model was also used to study the adsorption process. The thermodynamic parameters indicated the spontaneous and endothermic nature of the adsorption. Shrimp shell powder exhibited enough advantages such as large adsorption capacity, low cost, simple processing methods and high specific gravity compared with chitin or chitosan. This work confirmed that the shrimp shell biosorbent had a potential to be applied in dye wastewater treatment area

The Resource Utilization of Water Hyacinth (Eichhornia crassipes [Mart.] Solms) and Its Challenges

The unchecked growth of Eichhornia crassipes can cause significant harm, including covering of the water surface, depletion of oxygen, clogging of river channels, and promotion of the breeding of flies and mosquitoes. These effects can significantly impact farmland irrigation, water transportation, and human health. However, methods for controlling its growth are not ideal, and control using biological and chemical agents can result in secondary pollution. The utilization of E. crassipes as a resource, for example, as animal feed or organic substrates, can not only turn waste into valuable resources, but it can also solve the problem of its growth, thus bringing about economic and ecological benefits. In this paper, the growth and ecological characteristics of E. crassipes, its nutrient composition, and resource utilization approaches were reviewed. The challenges associated with the large-scale utilization of E. crassipes were also analyzed in order to provide references for the control and resource utilization of the species. Regarding challenges such as the difficulty of cultivation and the high cost of harvesting and dehydrating, it is necessary to investigate the proper water surface and coverage characteristics of E. crassipes cultivation to assure adequate biomass and protect the ecological landscape. It is also necessary to evaluate the effect of E. crassipes cultivation on the health of aquatic ecosystems and the safety of the water environment in order to prevent the significant potential ecological and environmental risks. In addition, developing portable, high-efficiency facilities to promote the effectiveness of harvesting, transportation and dehydration are needed, as well as further improvement in the techniques of utilization and assessment of the economic value

A critical review of cast-off crab shell recycling from the perspective of functional and versatile biomaterials

Shellfish cultivation is an expanding economic activity worldwide. However, the rapid development of crab farming and processing result in a large number of crab shells (CS). Utilizing CS could not only benefit the environment and economy but also promote the sustainable development of aquaculture. In this work, it reviews and analyzes recent attempts in CS recycling, including extracting chitin and its derivatives, for use as adsorbent and flocculant and for preparing polymer composites and catalysts, as well as medical applications. The challenges in these utilizations are discussed, and future research directions are proposed as well. Extracting chitin and its derivates, for use as adsorbent and flocculant, are recent major recycling approaches. Preparing polymer composites and carbon materials has gained more and more attentions. Biotechnology is an alternative method for extracting chitin and its derivates from CS, and high-efficiency desalted and deproteinized bacteria need to be screened. Immobilizing the CS-based adsorbents is the key of treating wastewater in continuous systems. Using CS as a biofiller to prepare polymer composites is promising, and surface modification to improve the interfacial compatibility between CS-based fillers and matrix needs to be further studied

<i>De novo</i> Assembly of the Indo-Pacific Humpback Dolphin Leucocyte Transcriptome to Identify Putative Genes Involved in the Aquatic Adaptation and Immune Response

<div><p>Background</p><p>The Indo-Pacific humpback dolphin (<i>Sousa chinensis</i>), a marine mammal species inhabited in the waters of Southeast Asia, South Africa and Australia, has attracted much attention because of the dramatic decline in population size in the past decades, which raises the concern of extinction. So far, this species is poorly characterized at molecular level due to little sequence information available in public databases. Recent advances in large-scale RNA sequencing provide an efficient approach to generate abundant sequences for functional genomic analyses in the species with un-sequenced genomes.</p><p>Principal Findings</p><p>We performed a <i>de novo</i> assembly of the Indo-Pacific humpback dolphin leucocyte transcriptome by Illumina sequencing. 108,751 high quality sequences from 47,840,388 paired-end reads were generated, and 48,868 and 46,587 unigenes were functionally annotated by BLAST search against the NCBI non-redundant and Swiss-Prot protein databases (E-value<10⁻⁵), respectively. In total, 16,467 unigenes were clustered into 25 functional categories by searching against the COG database, and BLAST2GO search assigned 37,976 unigenes to 61 GO terms. In addition, 36,345 unigenes were grouped into 258 KEGG pathways. We also identified 9,906 simple sequence repeats and 3,681 putative single nucleotide polymorphisms as potential molecular markers in our assembled sequences. A large number of unigenes were predicted to be involved in immune response, and many genes were predicted to be relevant to adaptive evolution and cetacean-specific traits.</p><p>Conclusion</p><p>This study represented the first transcriptome analysis of the Indo-Pacific humpback dolphin, an endangered species. The <i>de novo</i> transcriptome analysis of the unique transcripts will provide valuable sequence information for discovery of new genes, characterization of gene expression, investigation of various pathways and adaptive evolution, as well as identification of genetic markers.</p></div

Clusters of orthologous group (COG) classification.

<p>In total, 16,467 of the 48,868 sequences with NR hits were grouped into 25 COG classifications.</p

GO assignment for assembled unigenes.

<p>The results are summarized in three main categories: biological process, cellular component and molecular function. In total, 37,976 unigenes were assigned to GO. Classified gene objects are depicted as absolute numbers of the total number of gene objects with GO assignments.</p

Summary of the unigene hits in public protein databases.

<p>Summary of the unigene hits in public protein databases.</p

Overview of the Indo-Pacific humpback dolphin leucocytes transcriptome assembly.

<p>(A) The size distribution of the contigs obtained from <i>de novo</i> assembly of high-quality clean reads. (B) The size distribution of the unigenes produced from further assembly of contigs. (C) The size distribution of the CDS produced by searching unigene sequences against various protein databases (NR, Swiss-Prot, KEGG and COG, in order) using BLASTX (E-value<10⁻⁵). (D) Size distributions of the ESTs obtained from the ESTScan results. For unigene CDS that had no hits in the databases (NR, Swiss-Prot, KEGG and COG), the BLAST results were subjected to ESTScans and then converted into peptide sequences.</p

Characterization of the assembled unigenes against NR protein databases.

<p>(<b>A</b>) E-value distribution of BLAST hits for the assembled unigenes with a cutoff of 1E-5. (<b>B</b>) Similarity distribution of the top BLAST hits for the assembled unigenes with a cutoff of 1E-5. (<b>C</b>) Species distribution of the top BLAST hits for the assembled unigenes with a cutoff of 1E-5.</p