Theoretical study of isolated dangling bonds, dangling bond wires and dangling bond clusters on H:Si(100)-(2×\times1) surface

We theoretically study the electronic band structure of isolated unpaired and paired dangling bonds (DB), DB wires and DB clusters on H:Si(100)-(2$\times$1) surface using Extended H\"uckel Theory (EHT) and report their effect on the Si band gap. An isolated unpaired DB introduces a near-midgap state, whereas a paired DB leads to $\pi$ and $\pi^*$ states, similar to those introduced by an unpassivated asymmetric dimer (AD) Si(100)-(2$\times$1) surface. Such induced states have very small dispersion due to their isolation from the other states, which reside in conduction and valence band. On the other hand, the surface state induced due to an unpaired DB wire in the direction along the dimer row (referred to as $[\bar{1}10]$), has large dispersion due to the strong coupling between the adjacent DBs, being 3.84$\AA$ apart. However, in the direction perpendicular to the dimer row (referred to as [110]), due to the reduced coupling between the DBs being 7.68$\AA$ apart, the dispersion in the surface state is similar to that of an isolated unpaired DB. Apart from this, a paired DB wire in $[\bar{1}10]$ direction introduces $\pi$ and $\pi^*$ states similar to those of an AD surface and a paired DB wire in [110] direction exhibits surface states similar to those of an isolated paired DB, as expected. Besides this, we report the electronic structure of different DB clusters, which exhibit states inside the band gap that can be interpreted as superpositions of states due to unpaired and paired DBs.Comment: 7 pages, 10 figure, 1 tabl

Large Differences in Small RNA Composition Between Human Biofluids.

Extracellular microRNAs (miRNAs) and other small RNAs are implicated in cellular communication and may be useful as disease biomarkers. We systematically compared small RNAs in 12 human biofluid types using RNA sequencing (RNA-seq). miRNAs and tRNA-derived RNAs (tDRs) accounted for the majority of mapped reads in all biofluids, but the ratio of miRNA to tDR reads varied from 72 in plasma to 0.004 in bile. miRNA levels were highly correlated across all biofluids, but levels of some miRNAs differed markedly between biofluids. tDR populations differed extensively between biofluids. Y RNA fragments were seen in all biofluids and accounted for >10% of reads in blood plasma, serum, and cerebrospinal fluid (CSF). Reads mapping exclusively to Piwi-interacting RNAs (piRNAs) were very rare, except in seminal plasma. These results demonstrate extensive differences in small RNAs between human biofluids and provide a useful resource for investigating extracellular RNA biology and developing biomarkers

Leaf-applied sodium chloride promotes cadmium accumulation in durum wheat grain

Cadmium (Cd) accumulation in durum wheat grain is a growing concern. Among the factors affecting Cd accumulation in plants, soil chloride (Cl) concentration plays a critical role. The effect of leaf NaCl application on grain Cd was studied in greenhouse-grown durum wheat (Triticum turgidum L. durum, cv. Balcali-2000) by immersing (10 s) intact flag leaves into Cd and/or NaCl-containing solutions for 14 times during heading and dough stages. Immersing flag leaves in solutions containing increasing amount of Cd resulted in substantial increases in grain Cd concentration. Adding NaCl alone or in combination with the Cd-containing immersion solution promoted accumulation of Cd in the grains, by up to 41%. In contrast, Zn concentrations of grains were not affected or even decreased by the NaCl treatments. This is likely due to the effect of Cl complexing Cd and reducing positive charge on the metal ion, an effect that is much smaller for Zn. Charge reduction or removal (CdCl2 0 species) would increase the diffusivity/lipophilicity of Cd and enhance its capability to penetrate the leaf epidermis and across membranes. Of even more significance to human health was the ability of Cl alone to penetrate leaf tissue and mobilize and enhance shoot Cd transfer to grains, yet reducing or not affecting Zn transfer

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe

Optimization of distyryl-Bodipy chromophores for efficient panchromatic sensitization in dye sensitized solar cells

Cataloged from PDF version of article.Versatility of Bodipy (4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene) dyes was further expanded in recent dye-sensitized solar cell applications. Here we report a series of derivatives designed to address earlier problems in Bodipy sensitized solar cells. In the best case example, an overall efficiency of a modest 2.46% was achieved, but panchromatic nature of the dyes is quite impressive. This is the best reported efficiency in liquid electrolyte solar cells with Bodipy dyes as photosensitizers

A stereological study of the renal and adrenal glandular structure of red-legged partridge (Alectoris chukar)

Background: Partridge is a major bird species that has recently gained an increasing importance as an alternative food source and a game animal in hunting tourism. Herein, we aimed to examine the histological structure and stereological properties of the renal and adrenal glands of red-legged partridge. Materials and methods: Seven healthy adult red-legged partridges (Alectoris chukar) of both genders were used in this study. The Alectoris chukars were perfused with the intracardiac method and were kept in 10% formaldehyde for 72 h for optimal fixation. The tissues were embedded in paraffin after routine light microscopic processes. Then, 5-μm thick sections were taken, which were stained with haematoxylin and eosin, photographed, and examined in light microscope. Modified Cavalieri principle was used for volume calculation as stereological analysis. Total tissue volume ratios were calculated with the help of a point grid provided by the Shtereom 1.5 packaged programme. Mann Whitney-U test was used for inter-group comparisons. The significance level was set at 5% SPSS (ver: 13) statistical software was used for all statistical analyses. Results: Renal histological structure was found to resemble those of other bird species and contained a mixed type (mammalian, reptilian) glomerular structure. It was also found that the adrenal histology was not in the form of separate layers but composed of cell groups with different properties. Stereological renal volume assessment revealed statistically similar right and left renal size (p > 0.05). In adrenal gland volume assessment, the right and left adrenal volumes were also statistically similar (p > 0.05). Conclusions: The obtained data in the present study is thought to contribute to the understanding of the stereological, morphological and histological structure of the red-legged partridge (Alectoris chukar) kidney and adrenal gland

A stereological study: Volume estimation in the cerebellum of Norduz sheep

In this research, it was aimed to investigate the cerebellum volume values of Norduz sheep raised within the borders of Gurpinar district of Van province. For this purpose, 6 male and 6 female Norduz sheep heads were selected as materials. The brains were dissected and kept in formaldehyde for a week. Cerebellums were separated from the brain hemispheriums. For better fixation, the cerebellums were kept in formaldehyde again for a week. Tissues obtained by sequential random sampling were included in tissue tracking. Then each tissue was embedded in paraffin. An average of 10-12 sections with a thickness of 5µm were obtained from the tissue cassettes obtained by a Rotary microtome (Leica RM, 2135, Nussloch Germany). Sections stained with hematoxylin and eosin were photographed with an x4 objective. From these photographs, total cerebellum, medulla and cortex volumes, as well as vermis volume, were calculated using the Shtereom I program using the Cavalieri Principle. The results were evaluated statistically with the Mann-Whitney U test. No statistical difference was detected in terms of male and female cerebellum volume values, Coefficient of Error (CE) and Noise calculations (p>0.05). However, in the evaluation between genders, it was determined that the only difference was seen in the medulla section of the hemispherium cerebelli sinister (p<0.05). Keywords: Cavalieri Principle; cerebellum; Norduz sheep; stereology; volume

A morphological and stereological study on calculating volume values of thoracic segments of geese

Background: In this study, the total volume of the thoracic segments of the spinal cord and volume densities of grey matter and white matter were examined by using stereological methods in adult geese having a weight of 3–4 kg.  Materials and methods: Ten geese were used as material without sex discrimi- nation. All animals were perfused with 10% formaldehyde. In addition, after perfusion, the geese were kept in 10% formaldehyde for 1 week. Afterwards, thoracic spine was removed and thoracic part of spinal cord was excised. 5 μm thick sections were taken from these tissue samples by microtome. The cross- sectional series were obtained by sampling from each segment at 250th section. Twelve sections were taken from tissue specimens of every segment. The sections were stained by using haematoxylin-eosin and photographed on a microscope.  Results: By using the Cavalieri’s Principle, the volume densities (volume fractions) of thoracic segments of spinal cord, volume of white matter, and volume of grey matter in segments were calculated.  Conclusions: In the study, total volume of the thoracic segment, volume of white matter, and the volume of grey matter, and the ratio of these volume values to each other were calculated. The SHTEREOM 1.0 software was used for calculating the volume of section specimens.

Spinodal-assisted crystallization in polymer melts

Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To explain these observations we propose that the coupling between density and chain conformation induces a liquid-liquid binodal within the equilibrium liquid-crystalline solid coexistence region. A simple phenomenological theory is developed to illustrate this idea, and several experimentally testable consequences are discussed. Shear is shown to enhance the kinetic role of the hidden binodal

Subtle effects of environmental stress observed in the early life stages of the Common frog, Rana temporaria

Worldwide amphibian populations are declining due to habitat loss, disease and pollution. Vulnerability to environmental contaminants such as pesticides will be dependent on the species, the sensitivity of the ontogenic life stage and hence the timing of exposure and the exposure pathway. Herein we investigated the biochemical tissue ‘fingerprint’ in spawn and early-stage tadpoles of the Common frog, Rana temporaria, using attenuated total reflection- Fourier-transform infrared (ATR-FTIR) spectroscopy with the objective of observing differences in the biochemical constituents of the respective amphibian tissues due to varying water quality in urban and agricultural ponds. Our results demonstrate that levels of stress (marked by biochemical constituents such as glycogen that are involved in compensatory metabolic mechanisms) can be observed in tadpoles present in the pond most impacted by pollution (nutrients and pesticides), but large annual variability masked any inter-site differences in the frog spawn. ATR-FTIR spectroscopy is capable of detecting differences in tadpoles that are present in selected ponds with different levels of environmental perturbation and thus serves as a rapid and cost effective tool in assessing stress-related effects of pollution in a vulnerable class of organism