Design of Metasurface-Based Multi-layer THz Filters Utilizing Optimization Algorithm with Distinct Fitness Function Definitions

In this paper, an evolutionary optimization procedure is presented to generate band-pass metasurface-based filters in terahertz regime. As a measure of novelty, pass-band, transition, and out-band characteristics are investigated separately, all of which result in different metasurfaces for filtering applications. The presented approach is defined based on random hill climbing algorithm, regarding the established link between Matlab and HFSS software. A metasurface-based filter with specific properties is considered as the main problem to be solved by the optimization method. Moreover, the fuzzy theory, mean square method, and weighting coefficient procedure are considered to define an efficient fitness function evaluation approach. Also, a step-by-step procedure is used to generate desired structures with a great note of efficiency. The final generated structure has magnificent characteristics including sharp transitions together with transmittance around 0.68 and less than 0.04 at pass-band and out-band regions, respectively. Also, the generated metasurface benefits from wide bandwidth (65%) and great compactness compared to other previous works.

     

Lipocalin-2-mediated upregulation of various antioxidants and growth factors protects bone marrow-derived mesenchymal stem cells against unfavorable microenvironments

Despite many advantages of mesenchymal stem cells (MSCs) that make them suitable for cell therapy purposes, their therapeutic application has been limited due to their susceptibility to several stresses (e.g., nutrient-poor environment, oxidative stress, and hypoxic and masses of cytotoxic factors) to which they are exposed during their preparation and following transplantation. Hence, reinforcing MSCs against these stresses is a challenge for both basic and clinician scientists. Recently, much attention has been directed toward equipping MSCs with cytoprotective factors to strengthen them against unfavorable microenvironments. Here, we engineered MSCs with lipocalin 2 (Lcn2), a cytoprotective factor that is naturally induced following exposure of cells to stresses imposed by the microenvironment. Lcn2 overexpression not only did not interfere with the multidifferentiation capacity of the MSCs but also granted many protective properties to them. Lcn2 potentiated MSCs to withstand oxidative, hypoxia, and serum deprivation (SD) conditions via antagonizing their induced cytotoxicity and apoptosis. Adhesion rate of MSCs to coated culture plates was also enhanced by Lcn2 overexpression. In addition, Lcn2 induced antioxidants and upregulated some growth factors in MSCs. Our findings suggested a new strategy for prevention of graft cell death in MSC-based cell therapy.     

Sensitive measurement of single-nucleotide polymorphism-induced changes of RNA conformation: application to disease studies

Single-nucleotide polymorphisms (SNPs) are often linked to critical phenotypes such as diseases or responses to vaccines, medications and environmental factors. However, the specific molecular mechanisms by which a causal SNP acts is usually not obvious. Changes in RNA secondary structure emerge as a possible explanation necessitating the development of methods to measure the impact of single-nucleotide variation on RNA structure. Despite the recognition of the importance of considering the changes in Boltzmann ensemble of RNA conformers in this context, a formal method to perform directly such comparison was lacking. Here, we solved this problem and designed an efficient method to compute the relative entropy between the Boltzmann ensembles of the native and a mutant structure. On the basis of this theoretical progress, we developed a software tool, remuRNA, and investigated examples of its application. Comparing the impact of common SNPs naturally occurring in populations with the impact of random point mutations, we found that structural changes introduced by common SNPs are smaller than those introduced by random point mutations. This suggests a natural selection against mutations that significantly change RNA structure and demonstrates, surprisingly, that randomly inserted point mutations provide inadequate estimation of random mutations effects. Subsequently, we applied remuRNA to determine which of the disease-associated non-coding SNPs are potentially related to RNA structural changes.     

Effects of fusaric acid treatment on the protocorm-like bodies of <Emphasis Type="Italic">Dendrobium</Emphasis> sonia-28

Dendrobium sonia-28 is a popular orchid hybrid due to its flowering recurrence and dense inflorescences. Unfortunately, it is being decimated by fungal diseases, especially those caused by Fusarium proliferatum. In this study, selection of F. proliferatum-tolerant protocorm-like bodies (PLBs) was carried out by assessing the effects of differing concentrations of fusaric acid (FA). PLBs were cultured on Murashige and Skoog (MS) medium supplemented with 0.05 to 0.2 millimolar (mM) concentrations of FA. Higher concentrations of FA increased mortality of PLBs and reduced their growth. The survival rate for 0.05 mM FA was 20 % but only 1 % at the highest dose of 0.2 mM. Additionally, two different size ranges of PLBs were investigated, and growth increased more at lower FA concentrations for larger PLBs, whilst the growth rate of smaller PLBs was inhibited at an FA concentration of 0.2 mM. Histological examination using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses disclosed severe cell wall and organelle damage, as well as stomatal closure in PLBs treated with the high FA concentrations. Reductions in plantlet growth were much greater at the highest concentrations of FA. Some randomly amplified polymorphic DNA (RAPD) markers clearly discriminated between selected and non-selected variants of Dendrobium sonia-28, showing different banding patterns for each FA concentration and specific bands for selected and control plants.     

Effects of Probiotic Yogurt on Serum Omentin-1, Adropin,and Nesfatin-1 Concentrations in Overweight and Obese Participants Under Low-Calorie Diet

Probiotics and Antimicrobial Proteins - Data on the effects of probiotics on adipokines such as omentin-1, nesfatin-1, and adropin are limited. The aim of this study was to evaluate the effects of...     

Specific residues of the influenza A virus hemagglutinin viral RNA are important for efficient packaging into budding virions

A final step in the influenza virus replication cycle is the assembly of the viral structural proteins and the packaging of the eight segments of viral RNA (vRNA) into a fully infectious virion. The process by which the RNA genome is packaged efficiently remains poorly understood. In an approach to analyze how vRNA is packaged, we rescued a seven-segmented virus lacking the hemagglutinin (HA) vRNA (deltaHA virus). This virus could be passaged in cells constitutively expressing HA protein, but it was attenuated in comparison to wild-type A/WSN/33 virus. Supplementing the deltaHA virus with an artificial segment containing green fluorescent protein (GFP) or red fluorescent protein (RFP) with HA packaging regions (45 3' and 80 5' nucleotides) partially restored the growth of this virus to wild-type levels. The absence of the HA vRNA in the deltaHA virus resulted in a 40 to 60% reduction in the packaging of the PA, NP, NA, M, and NS vRNAs, as measured by quantitative PCR (qPCR), and the packaging of these vRNAs was partially restored in the presence of GFP/RFP packaging constructs. To further define nucleotides of the HA coding sequence which are important for vRNA packaging, synonymous mutations were introduced into the full-length HA cDNA of influenza A/WSN/33 and A/Puerto Rico/8/34 viruses, and mutant viruses were rescued. qPCR analysis of vRNAs packaged in these mutant viruses identified a key region of the open reading frame (nucleotides 1659 to 1671) that is critical for the efficient packaging of an influenza virus H1 HA segment.     

Additive inheritance of histone modifications in Arabidopsis thaliana intra-specific hybrids

Plant genomes are earmarked with defined patterns of chromatin marks. Little is known about the stability of these epigenomes when related, but distinct genomes are brought together by intra‐species hybridization. Arabidopsis thaliana accessions and their reciprocal hybrids were used as a model system to investigate the dynamics of histone modification patterns. The genome‐wide distribution of histone modifications H3K4me2 and H3K27me3 in the inbred parental accessions Col‐0, C24 and Cvi and their hybrid offspring was compared by chromatin immunoprecipitation in combination with genome tiling array hybridization. The analysis revealed that, in addition to DNA sequence polymorphisms, chromatin modification variations exist among accessions of A. thaliana. The range of these variations was higher for H3K27me3 (typically a repressive mark) than for H3K4me2 (typically an active mark). H3K4me2 and H3K27me3 were rather stable in response to intra‐species hybridization, with mainly additive inheritance in hybrid offspring. In conclusion, intra‐species hybridization does not result in gross changes to chromatin modifications.     

In vitro and computational studies on the effects of ARE deletion and targeted mutations on the expression of interferon beta-1a in HEK293T cells

Applied Microbiology and Biotechnology - Interferon beta (IFNβ) is transiently expressed in response to viral infections and widely used to treat relapsing-remitting multiple sclerosis (MS)....