Detection and thermal stabilization of virus based on surface properties

Viral diseases take the lives of millions of people each year. The most effective methods to prevent viral disease outbreak are viral detection to reduce contact with viral pathogens and vaccines to prevent disease. To reduce the costs of the detection of viruses and improve vaccine formulation, we explored viral surface properties. The properties we have focused on are viral hydrophobicity and surface charge using chemical force microscopy (CFM). CFM is a single-particle technique that measures the adhesion force of a functionalized atomic force microscopy (AFM) probe, and in this study, a virus covalently bound to a surface. The non-enveloped porcine parvovirus (PPV) and enveloped bovine viral diarrhea virus (BVDV) were used to demonstrate the use of CFM for viral particles with different surface properties. The high hydrophobicity of PPV and BVDV by CFM was used for a ligand-free, non-specific virus detection method that relies on the interaction of virus with osmolytes. It was previously found that the osmolyte mannitol can preferentially aggregate viruses while leaving proteins in solution. The virus was incubated with gold nanoparticles (AuNPs), and aggregation of the virus-AuNP complex with mannitol was detected by dynamic light scattering (DLS). The isoelectric point (pI) of PPV and BVDV by CFM was used for a vaccine formulation strategy of virus particle encapsulation by polymers that relies on electrostatic interactions of the virus with polypeptides. The random screen of different ratios of polyelectrolytes to encapsulate viruses could be reduced by knowing the virus pIs. An encapsulated non-enveloped PPV is thermally stabilized, demonstrating that this method is promising for formulating thermostable vaccines. We have developed a unique detection method and can improve vaccine formulation that would reduce the impact of viral diseases worldwide, based on the viral surface properties

Electrospun Quaternized Chitosan Fibers for Virus Removal from Drinking Water

Membrane filtration has become an accepted technology for the removal of pathogens from drinking water. Viruses, known to contaminate water supplies, are too small to be removed by a size-exclusion mechanism without a large energy penalty. Thus, functionalized electrospun membranes that can adsorb viruses have drawn our interest. We chose a quaternized chitosan derivative (HTCC) which carries a positively-charged quaternary amine, known to bind negatively-charged virus particles, as a functionalized membrane material. The technique of electrospinning was utilized to produce nanofiber mats with large pore diameters to increase water flux and decrease membrane fouling. In this study, stable, functionalized, electrospun HTCC-PVA nanofibers that can remove 3.6 logs (99.97%) of a model virus, porcine parvovirus (PPV), from water by adsorption and filtration have been successfully produced. This technology has the potential to purify drinking water in undeveloped countries and reduce the number of deaths due to lack of sanitation

Clinical analysis of 532nm frequency-doubled laser in treating retinal holes of 78 eyes

AIM: To evaluate the clinical effect of photocoagulation with 532nm frequency-doubled laser in patients with retinal hole.<p>METHODS: Seventy-two cases(78 eyes)with retinal holes were treated with 532nm frequency-doubled laser. All the eyes were divided according to the quadrants of location of retinal holes and the size of retinal hole and existence of local retinal detachment accompanying retinal holes. Statistical analysis was made on these data.<p>RESULTS: 1)The retinal holes were located in the upper quadrants of retina in 44 eyes and there were also retinal holes located in the lower quadrants of retina in 31 eyes(there were 3 eyes with retinal holes both located in the upper and lower quadrants of retina, which were not included in control group). The difference of photocoagulation effect between the two groups was statistically significant. 2)The retinal holes diameter ≤2 papilla diameter(PD)were present in 37 eyes, the holes diameter of retina >2PD were seen in 41 eyes, the difference of photocoagulation effect between the two groups was statistically significant. 3)Retinal holes without local retinal detachment were observed in 45 eyes, retinal holes with local retinal detachment were seen in 33 eyes, the difference of photocoagulation effect between the two groups was statistically significant.<p>CONCLUSION:Photocoagulation with 532nm frequency-doubled laser is effective and safe to treat retinal holes. The effect is better in patients with retinal holes in the upper quadrants and with the retinal holes diameter ≤2PD and without local retinal detachment

Research on a New Signature Scheme on Blockchain

With the rise of Bitcoin, blockchain which is the core technology of Bitcoin has received increasing attention. Privacy preserving and performance on blockchain are two research points in academia and business, but there are still some unresolved issues in both respects. An aggregate signature scheme is a digital signature that supports making signatures on many different messages generated by many different users. Using aggregate signature, the size of the signature could be shortened by compressing multiple signatures into a single signature. In this paper, a new signature scheme for transactions on blockchain based on the aggregate signature was proposed. It was worth noting that elliptic curve discrete logarithm problem and bilinear maps played major roles in our signature scheme. And the security properties of our signature scheme were proved. In our signature scheme, the amount will be hidden especially in the transactions which contain multiple inputs and outputs. Additionally, the size of the signature on transaction is constant regardless of the number of inputs and outputs that the transaction contains, which can improve the performance of signature. Finally, we gave an application scenario for our signature scheme which aims to achieve the transactions of big data on blockchain

Character-level Chinese-English Translation through ASCII Encoding

Character-level Neural Machine Translation (NMT) models have recently achieved impressive results on many language pairs. They mainly do well for Indo-European language pairs, where the languages share the same writing system. However, for translating between Chinese and English, the gap between the two different writing systems poses a major challenge because of a lack of systematic correspondence between the individual linguistic units. In this paper, we enable character-level NMT for Chinese, by breaking down Chinese characters into linguistic units similar to that of Indo-European languages. We use the Wubi encoding scheme, which preserves the original shape and semantic information of the characters, while also being reversible. We show promising results from training Wubi-based models on the character- and subword-level with recurrent as well as convolutional models.Comment: 7 pages, 3 figures, 3rd Conference on Machine Translation (WMT18), 201