The Scaffolds to Guide Fast Angiogenesis

Angiogenesis is one of the most challenging problems in bone structure repair. The different types of 3D fibrous morphology structure of the extracellular matrix for fasting angiogenesis have been studied. Due to the densely packed constructs and limited porosity of scaffold, the challenge still remains for scaffold fabrication. In this study, we fabricated PCL scaffold with growth factors and cells to guide fast angiogenesis by electro-spinning and electro-spray simultaneously. We developed a technique that electro-spinning encapsulates growth factors OPN(Recombinant Human Osteopontin) and SDF-1α(CXCL12) in poly(lactide-co-glycolide) (PLGA) microspheres into PCL 3D structures scaffold fibers. We also developed a new technique to fabricated cells into PCL scaffold coating with gelatin A. And tested release amount of growth factors in scaffold over 28 days and loading efficiency. We can prove that microsphere released growth factors successfully into release medium in vitro. The Young’s module and elongation rate been tested by the single axis tensile test. The migration in collagen gel and in fibers were tested and quantified by confocal fluorescence microscopy. In vitro cell migration study demonstrated that OPN and SDF-1 significantly increased the depth of cell migration. In vivo, the scaffold with growth factors improve the repair of bone fracture in RA mice. Based on the results, these 3D scaffold may have potential to engineer tissues for various applications

Lithium-salt mediated synthesis of a covalent triazine framework for highly stable lithium metal batteries

A new strategy for the synthesis of a covalent triazine framework (CTF‐1) was introduced based on the cyclotrimerization reaction of 1,4‐dicyanobenzene using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) under ionothermal conditions. LiTFSI not only served as a catalyst, but also facilitated the in situ generation and homogeneous distribution of LiF particles across the framework. The hierarchical structure resulting upon integration of CTF‐LiF onto an airlaid‐paper (AP) offered unique features for lithium metal anodes, such as lithiophilicity from CTF, interface stabilization from LiF, and sufficient lithium storage space from AP. Based on this synergistic effect, the AP‐CTF‐LiF anode exhibited stable cycling performance even at a current density of 10 mA cm−

Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis

This paper presents an investigation on the humidity sensitivity of deposited multi-walled carbon nanotube (MWCNT) networks using ac dielectrophoresis (DEP) between interdigitated electrodes (IDEs). MWCNTs dispersed in ethanol were trapped and enriched between IDEs on a Si/SiO2 substrate under a positive DEP force. After the DEP process, the ethanol was evaporated and the MWCNT network on a substrate with IDEs was put into a furnace for repeated thermal annealing. It was found that the resistance stability of the network was effectively improved through thermal annealing. The humidity sensitivity was obtained by measuring the resistance of the MWCNT network with different relative humidity at room temperature. The experimental results show the resistance increases linearly with increasing the relative humidity from 25% to 95% RH with a sensitivity of 0.5%/%RH. The MWCNT networks have a reversible humidity sensing capacity with response time and recovery time of about 3 s and 25 s, respectively. The resistance is dependent on temperature with a negative coefficient of about −0.33%/K in a temperature range from 293 K to 393 K

Engineered external guide sequences are highly effective in inducing RNase P for inhibition of gene expression and replication of human cytomegalovirus

External guide sequences (EGSs), which are RNA molecules derived from natural tRNAs, bind to a target mRNA and render the mRNA susceptible to hydrolysis by RNase P, a tRNA processing enzyme. Using an in vitro selection procedure, we have previously generated EGS variants that efficiently direct human RNase P to cleave a target mRNA in vitro. In this study, a variant was used to target the overlapping region of the mRNAs encoding human cytomegalovirus (HCMV) essential transcription regulatory factors IE1 and IE2. The EGS variant was ∼25-fold more active in inducing human RNase P to cleave the mRNA in vitro than the EGS derived from a natural tRNA. Moreover, a reduction of 93% in IE1/IE2 gene expression and a reduction of 3000-fold in viral growth were observed in HCMV-infected cells that expressed the variant, while cells expressing the tRNA-derived EGS exhibited a reduction of 80% in IE1/IE2 expression and an inhibition of 150-fold in viral growth. Our results provide the first direct evidence that EGS variant is highly effective in blocking HCMV gene expression and growth and furthermore, demonstrate the feasibility of developing effective EGS RNA variants for anti-HCMV applications by using in vitro selection procedures

Effective inhibition of HCMV UL49 gene expression and viral replication by oligonucleotide external guide sequences and RNase P

Abstract Background Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that typically causes asymptomatic infections in healthy individuals but may lead to serious complications in newborns and immunodeficient individuals. The emergence of drug-resistant strains of HCMV has posed a need for the development of new drugs and treatment strategies. Antisense molecules are promising gene-targeting agents for specific regulation of gene expression. External guide sequences (EGSs) are oligonucleotides that consist of a sequence complementary to a target mRNA and recruit intracellular RNase P for specific degradation of the target RNA. The UL49-deletion BAC of HCMV was significantly defective in growth in human foreskin fibroblasts. Therefore, UL49 gene may serve as a potential target for novel drug development to combat HCMV infection. In this study, DNA-based EGS molecules were synthesized to target the UL49 mRNA of human cytomegalovirus (HCMV). Results By cleavage activity assessing in vitro, the EGS aimed to the cleavage site 324 nt downstream from the translational initiation codon of UL49 mRNA (i.e. EGS324) was confirmed be efficient to direct human RNase P to cleave the target mRNA sequence. When EGS324 was exogenously administered into HCMV-infected human foreskin fibroblasts (HFFs), a significant reduction of ~76% in the mRNA and ~80% in the protein expression of UL49 gene, comparing with the cells transfected with control EGSs. Furthermore, a reduction of about 330-fold in HCMV growth were observed in HCMV-infected HFFs treated with the EGS. Conclusions These results indicated that UL49 gene was essential for replication of HCMV. Moreover, our study provides evidence that exogenous administration of a DNA-based EGS can be used as a potential therapeutic approach for inhibiting gene expression and replication of a human virus.</p

AUV SLAM and experiments using a mechanical scanning forward-looking sonar

Navigation technology is one of the most important challenges in the applications of autonomous underwater vehicles (AUVs) which navigate in the complex undersea environment. The ability of localizing a robot and accurately mapping its surroundings simultaneously, namely the simultaneous localization and mapping (SLAM) problem, is a key prerequisite of truly autonomous robots. In this paper, a modified-FastSLAM algorithm is proposed and used in the navigation for our C-Ranger research platform, an open-frame AUV. A mechanical scanning imaging sonar is chosen as the active sensor for the AUV. The modified-FastSLAM implements the update relying on the on-board sensors of C-Ranger. On the other hand, the algorithm employs the data association which combines the single particle maximum likelihood method with modified negative evidence method, and uses the rank-based resampling to overcome the particle depletion problem. In order to verify the feasibility of the proposed methods, both simulation experiments and sea trials for C-Ranger are conducted. The experimental results show the modified-FastSLAM employed for the navigation of the C-Ranger AUV is much more effective and accurate compared with the traditional methods

OSBP-Related Protein 8 (ORP8) Regulates Plasma and Liver Tissue Lipid Levels and Interacts with the Nucleoporin Nup62

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