Abstract As bioabsorbable materials, magnesium alloys are expected to be totally degraded in the body and their biocorrosion products not deleterious to the surrounding tissues. It's critical that ...the alloying elements are carefully selected in consideration of their cytotoxicity and hemocompatibility. In the present study, nine alloying elements Al, Ag, In, Mn, Si, Sn, Y, Zn and Zr were added into magnesium individually to fabricate binary Mg–1X (wt.%) alloys. Pure magnesium was used as control. Their mechanical properties, corrosion properties and in vitro biocompatibilities (cytotoxicity and hemocompatibility) were evaluated by SEM, XRD, tensile test, immersion test, electrochemical corrosion test, cell culture and platelet adhesion test. The results showed that the addition of alloying elements could influence the strength and corrosion resistance of Mg. The cytotoxicity tests indicated that Mg–1Al, Mg–1Sn and Mg–1Zn alloy extracts showed no significant reduced cell viability to fibroblasts (L-929 and NIH3T3) and osteoblasts (MC3T3-E1); Mg–1Al and Mg–1Zn alloy extracts indicated no negative effect on viabilities of blood vessel related cells, ECV304 and VSMC. It was found that hemolysis and the amount of adhered platelets decreased after alloying for all Mg–1X alloys as compared to the pure magnesium control. The relationship between the corrosion products and the in vitro biocompatibility had been discussed and the suitable alloying elements for the biomedical applications associated with bone and blood vessel had been proposed.
Abstract Mg–Zn–Ca bulk metallic glass with different compositions (Mg66Zn30Ca4 and Mg70Zn25Ca5) have been prepared for this study and their feasibility as biodegradable metallic materials have been ...evaluated by the microstructural, surface analysis, mechanical testing, corrosion and cytotoxicity tests. It was found that the Mg66Zn30Ca4 sample presents a more uniform corrosion morphology than as-rolled pure Mg and Mg70Zn25Ca5 samples, with much smaller micro-scale uniformly distributed pores beneath the corrosion product layer. The corrosion products were identified to be Mg(OH)2 and Zn(OH)2 , and a uniform corrosion mechanism is proposed. Both indirect cytotoxicity and direct cell culture experiments were carried out using L929 and MG63 cell lines. The results show higher cell viabilities for Mg–Zn–Ca extracts than that for as-rolled pure Mg. In addition, L929 and MG63 cells were found to adhere and proliferate on the surface of Mg66Zn30Ca4 sample.
Additive manufacturing has received tremendous attention in the manufacturing and materials industry in the past three decades. Zirconia-based advanced ceramics have been the subject of substantial ...interest related to structural and functional ceramics. NanoParticle Jetting (NPJ), a novel material jetting process for selectively depositing nanoparticles, is capable of fabricating dense zirconia components with a highlydetailed surface, precisely controllable shrinkage, and remarkable mechanical properties. The use of NPJ greatly improves the 3D printing process and increases the printing accuracy. An investigation into the performance of NPJ-printed ceramic components evaluated the physical and mechanical properties and microstructure. The experimental results suggested that the NPJ-fabricated ZrO2 cuboids exhibited a high relative density of 99.5%, a glossy surface with minimum roughness of 0.33 μm, a general linear shrinkage factor of 17.47%, acceptable hardness of 12.43 ± 0.09 GPa, outstanding fracture toughness of 7.52 ± 0.34 MPa m1/2, comparable flexural strength of 699 ± 104 MPa, dense grain distribution of the microstructure, and representative features of the fracture. Subsequently, the exclusive printing scheme that achieved these favorable properties was analyzed. The innovative NanoParticle Jetting™ system was shown to have significant potential for additive manufacturing.
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Kuruma shrimp (Marsupenaeus japonicus) is one of the most valuable crustacean species in capture fisheries and mariculture in the Indo-West Pacific. White spot syndrome virus (WSSV) is a highly ...virulent pathogen which has seriously threatened Kuruma shrimp aquaculture sector. However, little information is available in relation to underlying mechanisms of host-virus interaction in Kuruma shrimp. In this study, we performed a transcriptome analysis from the hepatopancreas of Kuruma shrimp challenged by WSSV, using Illumina-based RNA-Seq. A total of 39,084,942 pair end (PE) reads, including 19,566,190 reads from WSSV-infected group and 19,518,752 reads from non-infected (control) group, were obtained and assembled into 33,215 unigenes with an average length of 503.7 bp and N50 of 601 bp. Approximately 17,000 unigenes were predicted and classified based on homology search, gene ontology, clusters of orthologous groups of proteins, and biological pathway mapping. Differentially expressed genes (DEGs), including 2150 up-regulated and 1931 down-regulated, were found. Among those, 805 DEGs were identified and categorized into 14 groups based on their possible functions. Many genes associated with JAK–STAT signaling pathways, Integrin-mediated signal transduction, Ras signaling pathways, apoptosis and phagocytosis were positively modified after WSSV challenge. The proteolytic cascades including Complement-like activation and Hemolymph coagulations likely participated in antiviral immune response. The transcriptome data from hepatopancreas of Kuruma shrimp under WSSV challenge provided comprehensive information for identifying novel immune related genes in this valuable crustacean species despite the absence of the genome database of crustaceans.
•First Marsupenaeus japonicus transcriptome aimed to characterize immune response involved in WSSV infection.•Complement-like activation and Hemolymph coagulations may be important in defensing WSSV.•JAK–STAT and Ras signaling pathways were positively modified under WSSV infection.•Apoptosis and phagocytosis were induced during against WSSV infection.
It was found that the real-time fluidization state can be monitored with the help of electric current acquisition during a fluidized bed reduction of iron ore fines, which might be used to the ...prediction of de-fluidization and localized fluidization state monitoring in a plant-scale fluidized bed. All Fe, FeO, and Fe3O4 phases have been proven to be conductive at high temperatures. In addition, the electric current detected in a fluidized bed under a normal fluidized state is virtually zero even for conductive bed materials. The solid bridges that emerged between these conductive particles were proved to be the cause of conductivity in a fluidized bed.
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•The fluidization or de-fluidization states can be reflected on-line by this method.•All Fe, FeO and Fe3O4 phases are proved to be conductive at high temperatures.•The conductivity is thought to be caused by solid bridges between particles.•The proper voltage is no need to be very high which is below 5 V in this study.
is widely consumed as a key food and medicine. Polysaccharides are one of the most plentiful constituents of this marine plant. In this study, several polysaccharide fractions with different charge ...numbers were obtained. Their physicochemical properties and anticoagulant activities were determined by chemical and instrumental methods. The chemical analysis showed that
polysaccharides (LJPs) and the purified fractions LJP0, LJP04, LJP06, and LJP08 mainly consisted of mannose, glucuronic acid, galactose, and fucose in different mole ratios. LJP04 and LJP06 also contained minor amounts of xylose. The polysaccharide fractions eluted by higher concentration of NaCl solutions showed higher contents of uronic acid and sulfate group. Biological activity assays showed that LJPs LJP06 and LJP08 could obviously prolong the activated partial thromboplastin time (APTT), indicating that they had strong anticoagulant activity. Furthermore, we found that LJP06 exerted this activity by inhibiting intrinsic factor Xase with higher selectivity than other fractions, which may have negligible bleeding risk. The sulfate group may play an important role in the anticoagulant activity. In addition, the carboxyl group and surface morphology of these fractions may affect their anticoagulant activities. The results provide information for applications of
polysaccharides, especially LJP06 as anticoagulants in functional foods and therapeutic agents.
Echinoderms have been attracting increasing attention for their polysaccharides, with unique chemical structure and enormous potential for preparing drugs to treat diseases. In this study, a glucan ...(TPG) was obtained from the brittle star
. Its structure was elucidated by physicochemical analysis and by analyzing its low-molecular-weight products as degraded by mild acid hydrolysis. The TPG sulfate (TPGS) was prepared, and its anticoagulant activity was investigated for potential development of anticoagulants. Results showed that TPG consisted of a consecutive α1,4-linked D-glucopyranose (D-Glc
) backbone together with a α1,4-linked D-Glc
disaccharide side chain linked through C-1 to C-6 of the main chain. The TPGS was successfully prepared with a degree of sulfation of 1.57. Anticoagulant activity results showed that TPGS significantly prolonged activated partial thromboplastin time, thrombin time, and prothrombin time. Furthermore, TPGS obviously inhibited intrinsic tenase, with an EC
value of 77.15 ng/mL, which was comparable with that of low-molecular-weight heparin (LMWH) (69.82 ng/mL). TPGS showed no AT-dependent anti-FIIa and anti-FXa activities. These results suggest that the sulfate group and sulfated disaccharide side chains play a crucial role in the anticoagulant activity of TPGS. These findings may provide some information for the development and utilization of brittle star resources.
NK-lysin is a component of natural killer cells and cytotoxic T lymphocytes, and it plays an important role in the innate immune response of aquatic animals against various pathogens. In this study, ...a 640 base pair full-length cDNA sequence of the NK-lysin gene from black sea bass (Centropristis striata) (CsNKl) was obtained and analyzed. Tissue distribution results showed that CsNKl was widely distributed in various tissues of C. striata, but a significantly high expression level was detected in the spleen. CsNKl also exhibited time-dependent expression in different tissues after challenge with Vibrio harveyi. Two antimicrobial peptides (CsNKl-26 and CsNKl-28) were predicted from CsNKl proteins, and they demonstrated bactericidal functions against a variety of bacteria. Scanning electron microscopy analysis revealed that CsNKl-26 and CsNKl-28 played their bactericidal roles using the classical alpha-helix antimicrobial peptide route. These results illustrate the immune functions of CsNKl against V. harveyi, and they can be applied to developing disease control methods for fish.
Stichopus ocellatus, known as eye-spotted sea cucumber, is a commercially important Stichopodidae holothuroid in Indo-Pacific region for its valuable nutrition and medicinal ingredients. However, ...because the taxonomic analyses based on morphological characters and molecular data within Aspidochirotida are limited, the deep-level evolutionary relationships of Aspidochirotida are still poorly understood. Here, for providing better insight of future evolutionary and taxonomic classification of Stichopodidae, we report the first complete mitogenome of S. ocellatus along with 37 annotated and characterized mitochondrial genes, and the phylogenetic analysis based on mitogenome data reveals sister relationship between S. ocellatus and S. monotuberculatus.
