"Polymer-Based Flexible and Wearable Vibration-Sensitive Vocal Sensor for Harsh Acoustic Environment"

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Electret-based skin-attachable vocal sensor for harsh acoustic environment

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Tracking the Fate of Porous Silicon Nanoparticles Delivering a Peptide Payload by Intrinsic Photoluminescence Lifetime

A nanoparticle system for systemic delivery of therapeutics is described, which incorporates a means of tracking the fate of the nanocarrier and its residual drug payload in vivo by photoluminescence (PL). Porous silicon nanoparticles (PSiNPs) containing the proapoptotic antimicrobial peptide payload, (D)[KLAKLAK](2), are monitored by measurement of the intrinsic PL intensity and the PL lifetime of the nanoparticles. The PL lifetime of the PSiNPs is on the order of microseconds, substantially longer than the nanosecond lifetimes typically exhibited by conventional fluorescent tags or by autofluorescence from cells and tissues; thus, emission from the nanoparticles is readily discerned in the time-resolved PL spectrum. It is found that the luminescence lifetime of the PSiNP host decreases as the nanoparticle dissolves in phosphate-buffered saline solution (37 degrees C), and this correlates with the extent of release of the peptide payload. The time-resolved PL measurement allows tracking of the in vivo fate of PSiNPs injected (via tail vein) into mice. Clearance of the nanoparticles through the liver, kidneys, and lungs of the animals is observed. The luminescence lifetime of the PSiNPs decreases with increasing residence time in the mice, providing a measure of half-life for degradation of the drug nanocarriers

Next-Generation Sequencing Reveals Frequent Opportunities for Exposure to Hepatitis C Virus in Ghana.

Globally, hepatitis C Virus (HCV) infection is responsible for a large proportion of persons with liver disease, including cancer. The infection is highly prevalent in sub-Saharan Africa. West Africa was identified as a geographic origin of two HCV genotypes. However, little is known about the genetic composition of HCV populations in many countries of the region. Using conventional and next-generation sequencing (NGS), we identified and genetically characterized 65 HCV strains circulating among HCV-positive blood donors in Kumasi, Ghana. Phylogenetic analysis using consensus sequences derived from 3 genomic regions of the HCV genome, 5'-untranslated region, hypervariable region 1 (HVR1) and NS5B gene, consistently classified the HCV variants (n = 65) into genotypes 1 (HCV-1, 15%) and genotype 2 (HCV-2, 85%). The Ghanaian and West African HCV-2 NS5B sequences were found completely intermixed in the phylogenetic tree, indicating a substantial genetic heterogeneity of HCV-2 in Ghana. Analysis of HVR1 sequences from intra-host HCV variants obtained by NGS showed that three donors were infected with >1 HCV strain, including infections with 2 genotypes. Two other donors share an HCV strain, indicating HCV transmission between them. The HCV-2 strain sampled from one donor was replaced with another HCV-2 strain after only 2 months of observation, indicating rapid strain switching. Bayesian analysis estimated that the HCV-2 strains in Ghana were expanding since the 16th century. The blood donors in Kumasi, Ghana, are infected with a very heterogeneous HCV population of HCV-1 and HCV-2, with HCV-2 being prevalent. The detection of three cases of co- or super-infections and transmission linkage between 2 cases suggests frequent opportunities for HCV exposure among the blood donors and is consistent with the reported high HCV prevalence. The conditions for effective HCV-2 transmission existed for ~ 3-4 centuries, indicating a long epidemic history of HCV-2 in Ghana

A systematic study on the discrepancy of fluorescence properties between in solutions and in cells: super-bright, environment-insensitive benzocoumarin dyes

The benzocoumarin dyes fluoresce negligibly in aqueous media but very strongly in cells, whereas representative conventional dyes display contrasting behaviour; the distinct emission behaviour of the fluorophores in organic solutions, in aqueous media, and in cell convinces the uniqueness of the cellular environment. Thein cellulosuperbright benzocoumarins also reveal an environment-insensitive emission behaviour, which is required for the reliable analysisviaratiometric imaging

Bayesian skyline plot, showing the epidemic history of HCV genotype 2.

<p>The thick black line in the middle represents the estimated mean effective number of infections through time in years. The two grey lines represent the 95% highest posterior density of this estimate.</p

Maximum likelihood tree reconstructed with NS5b gene sequences from West and Central Africa.

<p>Sequences from Ghana generated in this study are shown as red filled circles, those reported from West Africa as black filled triangles and those from Central Africa as black unfilled squares. Ghanaian sequences obtained from the GenBank are shown in blue filled circles.</p

Maximum likelihood tree reconstructed with consensus NS5b, 5'UTR and consensus HVR1 gene sequences generated in this study.

<p>HCV-1 isolates are shown in black unfilled circles while HCV-2 are shown in black filled circles.</p

Maximum likelihood tree reconstructed with intra-host variants of HVR1 gene sequences of HCV genotype 1.

<p>Only unique haplotypes are shown. Individual samples are labeled with distinct identifiers beginning with letter ‘k’ and displayed with different colors.</p

PFnet of all sequences present in two patients at different time points.

<p>Each time point is shown with a different color. Sequences found on the first time point are shown in red and the second time point in blue. Each node represents a single sequence variant. The size of the node reflects frequency of the corresponding variant in the population. This network includes all of the links in any minimum spanning tree. The time interval between each time point is ~2 months.</p