Research progress of hydrogels as delivery systems and scaffolds in the treatment of secondary spinal cord injury

Secondary spinal cord injury (SSCI) is the second stage of spinal cord injury (SCI) and involves vasculature derangement, immune response, inflammatory response, and glial scar formation. Bioactive additives, such as drugs and cells, have been widely used to inhibit the progression of secondary spinal cord injury. However, the delivery and long-term retention of these additives remain a problem to be solved. In recent years, hydrogels have attracted much attention as a popular delivery system for loading cells and drugs for secondary spinal cord injury therapy. After implantation into the site of spinal cord injury, hydrogels can deliver bioactive additives in situ and induce the unidirectional growth of nerve cells as scaffolds. In addition, physical and chemical methods can endow hydrogels with new functions. In this review, we summarize the current state of various hydrogel delivery systems for secondary spinal cord injury treatment. Moreover, functional modifications of these hydrogels for better therapeutic effects are also discussed to provide a comprehensive insight into the application of hydrogels in the treatment of secondary spinal cord injury

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Composition, diversity and function of intestinal microbiota in pacific white shrimp (Litopenaeus vannamei) at different culture stages

Intestinal microbiota is an integral component of the host and plays important roles in host health. The pacific white shrimp is one of the most profitable aquaculture species commercialized in the world market with the largest production in shrimp consumption. Many studies revealed that the intestinal microbiota shifted significantly during host development in other aquaculture animals. In the present study, 22 shrimp samples were collected every 15 days from larval stage (15 day post-hatching, dph) to adult stage (75 dph) to investigate the intestinal microbiota at different culture stages by targeting the V4 region of 16S rRNA gene, and the microbial function prediction was conducted by PICRUSt. The operational taxonomic unit (OTU) was assigned at 97% sequence identity. A total of 2,496 OTUs were obtained, ranging from 585 to 1,239 in each sample. Forty-three phyla were identified due to the classifiable sequence. The most abundant phyla were Proteobacteria, Cyanobacteria, Tenericutes, Fusobacteria, Firmicutes, Verrucomicrobia, Bacteroidetes, Planctomycetes, Actinobacteria and Chloroflexi. OTUs belonged to 289 genera and the most abundant genera were Candidatus_Xiphinematobacter, Propionigenium, Synechococcus, Shewanella and Cetobacterium. Fifty-nine OTUs were detected in all samples, which were considered as the major microbes in intestine of shrimp. The intestinal microbiota was enriched with functional potentials that were related to transporters, ABC transporters, DNA repair and recombination proteins, two component system, secretion system, bacterial motility proteins, purine metabolism and ribosome. All the results showed that the intestinal microbial composition, diversity and functions varied significantly at different culture stages, which indicated that shrimp intestinal microbiota depended on culture stages. These findings provided new evidence on intestinal microorganism microecology and greatly enhanced our understanding of stage-specific community in the shrimp intestinal ecosystem

High-Performance Amorphous Zinc–Tin–Oxide Thin-Film Transistors With Low Tin Concentration

In this paper, we present thin-film transistors (TFTs) with a zinc–tin–oxide (ZTO) layer achieved through magnetron co-sputtering. Amorphous ZTO TFTs with an Sn concentration of 2.49%, 6.95%, 7.11%, 11.95%, and 16.47% were fabricated, to investigate the effect of low-doped Sn. With a doping of 2.49% Sn, the electrical characteristics of TFTs can be obviously improved. After annealing at 440 °C, the optimal TFTs displayed a field-effect mobility of 8.71 cm2/ $\text{V}\cdot \text{s}$ , a high $\text{I}_{\mathrm{ on/off}}$ ratio of over $10^{8}$ , a subthreshold swing of 0.17 V/decade, and a turn-on voltage of −0.4 V, even with an Sn concentration of only 11.95%. Meanwhile, the shift of turn-on voltage under negative gate bias stress was only −0.4 V

Environmental Factors Shape Water Microbial Community Structure and Function in Shrimp Cultural Enclosure Ecosystems

The effects of environmental factors on water microbial communities have been extensively studied, but little is known about the effects in shrimp cultural enclosure ecosystems. We analyzed 16S rRNA gene amplicons to determine the principal environmental factors that shape the structure and function of microbial communities in shrimp cultural enclosure ecosystems from Guangdong and Hainan provinces, in China. High quality sequences were clustered into operational taxonomic units (OTUs) at the 97% similarity level, generating 659–1,835 OTUs per sample. The 10 most abundant phyla were Proteobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Actinobacteria, Verrucomicrobia, Firmicutes, Chlorobi, Chloroflexi, and Chlamydiae. The results of canonical correspondence analyses (CCA) indicated that salinity, total phosphate (TP), total nitrogen (TN), temperature, and pH were the most important factors shaping microbial community structure. Differences in microbial community structure between high and low salinity samples were explained by changes in the relative abundances of some OTUs (e.g., OTU5, OTU19, OTU21, OTU39, and OTU71). Moreover, the contribution of spatial distribution to the microbial community assembly was investigated via aggregated boosted tree (ABT) analyses, and the results indicated spatial isolation was not a major factor affecting the phylogenetic diversity and phylotypes of water microbial communities. Furthermore, we predicted water microbial community functional profiling using the PICRUSt program and principal component analyses (PCA) suggested that salinity was a major contributor to the structure and function of the microbial communities. Collectively, these results showed that environmental factors influenced the structure and function of water microbial communities, while salinity was the principal environmental factor instead of temperature, TP, TN, and pH in shrimp cultural enclosure ecosystems

EMSCs‐Seeded Micro‐Stripe Patterned Polycaprolactone Promoting Sciatic Nerve Regeneration

Abstract Transplantation of a synthetic polymer nerve conduit carrying stem cells is promising for treating peripheral nerve injury. In this study, a micropatterned inner surface of polycaprolactone (PCL) nerve conduit cellularized with nasal respiratory mucosa‐derived ectoderm mesenchymal stem cells (EMSCs) is adopted for peripheral nerve regeneration. The PCL microstructure grating is fabricated by soft nanoimprint lithography (NIL), whose templates can be easily transferred from the Ebeam photoresist pattern. The most suitable microstructure is carefully chosen to support EMSCs alignment and nerve regeneration. In vitro, the micropatterned PCL nerve conduit greatly enhanced the directional alignment of EMSCs and the MBP and S100 expression of myelin proteins. Additionally, the micropatterned conduit preseeded with EMSCs significantly stimulated the axon‐directed extension of neural stem cells. In vivo, micropatterned PCL conduits cotransplanted with EMSCs enhanced motor function and promoted sciatic nerve regeneration and extension in a rat model of sciatic nerve defect. Taken together, this “all‐in‐one” nerve guidance conduit makes sciatic nerve regeneration and morphological repairing accelerated, which has a potential clinical application in neural tissue engineering

VP23R of Infectious Spleen and Kidney Necrosis Virus Mediates Formation of Virus-Mock Basement Membrane To Provide Attaching Sites for Lymphatic Endothelial Cells ▿

Putative open reading frames (ORFs) encoding laminin-like proteins are found in all members of the genus Megalocytivirus, family Iridoviridae. This is the first study that identified the VP23R protein encoded by ORF23R of the infectious spleen and kidney necrosis virus (ISKNV), a member of these genes of megalocytiviruses. The VP23R mRNA covering the ISKNV genomic coordinates 19547 to 22273 was transcribed ahead of the major capsid protein. Immunofluorescence analysis demonstrated that VP23R was expressed on the plasma membrane of the ISKNV-infected cells and could not be a viral envelope protein. Residues 292 to 576 of VP23R are homologous to the laminin γ1III2-6 fragment, which covers the nidogen-binding site. An immunoprecipitation assay showed that VP23R could interact with nidogen-1, and immunohistochemistry showed that nidogen-1 was localized on the outer membrane of the infected cells. Electron microscopy showed that a virus-mock basement membrane (VMBM) was formed on the surface of the infected cells and a layer of endothelial cells (ECs) was attached to the VMBM. The VMBM contained VP23R and nidogen-1 but not collagen IV. The attached ECs were identified as lymphatic endothelial cells (LECs), which have unique feature of overlapping intercellular junctions and can be stained by immunohistochemistry using an antibody against a specific lymphatic marker, Prox-1. Such infection signs have never been described in viruses. Elucidating the functions of LECs attached to the surface of the infected cells may be useful for studies on the pathogenic mechanisms of megalocytiviruses and may also be important for studies on lymphangiogenesis and basement membrane functions