Cation Substitution of Solution‐Processed Cu2ZnSnS4 Thin Film Solar Cell with over 9% Efficiency

To alleviate the limitations of pure sulfide Cu₂ZnSnS₄ (CZTS) thin film, such as band gaps adjustment, antisite defects, secondary phase and microstructure, Cadmium is introduced into CZTS thin film to replace Zn partially to form Cu₂Zn_1?xCd_xSnS₄ (CZCTS) thin film by low‐cost sol–gel method. It is demonstrated that the band gaps and crystal structure of CZCTS thin films are affected by the change in Zn/Cd ratio. In addition, the ZnS secondary phase can be decreased and the grain sizes can be improved to some degree by partial replacement of Zn with Cd in CZCTS thin film. The power conversion efficiency of CZTS solar cell device is enhanced significantly from 5.30% to 9.24% (active area efficiency 9.82%) with appropriate ratio of Zn/Cd. The variation of device parameter as a function of Zn/Cd ratio may be attributed to the change in electronic structure of the bulk CZCTS thin film (i.e., phase change from kesterite to stannite), which in turn affects the band alignment at the CZCTS/buffer interface and the charge separation at this interface.     

Contrasting patterns of diversity and population differentiation at the innate immunity gene toll-like receptor 2 (TLR2) in two sympatric rodent species

Comparing patterns of diversity and divergence between populations at immune genes and neutral markers can give insights into the nature and geographic scale of parasite-mediated selection. To date, studies investigating such patterns of selection in vertebrates have primarily focused on the acquired branch of the immune system, whereas it remains largely unknown how parasite-mediated selection shapes innate immune genes both within and across vertebrate populations. Here, we present a study on the diversity and population differentiation at the innate immune gene Toll-like receptor 2 (TLR2) across nine populations of yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) in southern Sweden. In yellow-necked mice, TLR2 diversity was very low, as was TLR2 population differentiation compared to neutral loci. In contrast, several TLR2 haplotypes co-occurred at intermediate frequencies within and across bank vole populations, and pronounced isolation by distance between populations was observed. The diversity and differentiation at neutral loci was similar in the two species. These results indicate that parasite-mediated selection has been acting in dramatically different ways on a given immune gene in ecologically similar and sympatric species. Furthermore, the finding of TLR2 population differentiation at a small geographical scale in bank voles highlights that vertebrate innate immune defense may be evolutionarily more dynamic than has previously been appreciated.     

Olfactomedin III expression contributes to anoikis-resistance in clonal variants of a human lung squamous carcinoma cell line

Three clonal subpopulations of DLKP, a poorly differentiated squamous lung carcinoma cell line, display striking differences in ability to survive in suspension (anoikis resistance). DLKP-SQ is anoikis resistant (7.5% anoikis at 24 h). In contrast, DLKP-M and DLKP-I are sensitive to anoikis (49.2% and 42.6% respectively). DLKP-I shows increased apoptosis consistently over all time points tested while DLKP-M appear to slow down metabolically and perhaps delays onset of anoikis by undergoing autophagy. Expression microarray analysis identified pronounced differential expression of Olfactomedin 3 (OLFM3) between the clones. High expression of OLFM3 was confirmed at the RNA level by qRT-PCR in DLKP-SQ and at the protein level by Western blotting (within the cell and secreted). Little or no OLFM3 was detected in the other two clones (DLKP-M and DLKP-I). Following siRNA knockdown of OLFM3 in DLKP-SQ, anoikis was increased 2.8-fold to 21% which was intermediate between the anoikis levels in DLKP-SQ and DLKP-M or DLKP-I. This knockdown correlated with increased apoptosis in suspension but not in attached culture conditions. Addition of recombinant OLFM3 reduced anoikis in DLKP-I. This is the first instance of OLFM3 being linked with anoikis resistance in a human cancer cell line.     

Ecological assessment of Portuguese reservoirs based on littoral epilithic diatoms

Hydrobiologia - The objective of this study was to evaluate whether biological methods based on epilithic littoral diatoms are a valuable complement to other biological elements for the assessment...     

Hyaluronic acid depolymerization by ascorbate-redox effects on solid state cultivation of <Emphasis Type="Italic">Streptococcus zooepidemicus</Emphasis> in cashew apple fruit bagasse

The cashew fruit (Anacardium occidentale L.) has been used as a promising agricultural resource for the production of low-molecular weight (M_W) hyaluronic acid (HA) (10⁴–10⁵ Da). The cashew juice is a rich source of vitamin C containing, 1.2–2.0 g L⁻¹. This work explores the effects of the initial concentration of the ascorbate on the solid fermentation of the juice-moisturized bagasse from the cashew apple fruit. The results show that the M_W reduction of HA is proportional to the initial ascorbate concentration. The presence of ascorbate did not influence the Streptococcus zooepidemicus metabolism. However, the HA productivity was increased from 0.18 to 0.28 mg g⁻¹ h⁻¹ when the ascorbate concentration ranged from 1.7 to 10 mg mL⁻¹. These findings contribute to the controlled production of HA in a low M_W range, which is important in cell signalization, angiogenesis and nanoparticles production.     

Glycosphingolipid profile of the apical pole of human placental capillaries: the relevancy of the observed data to Fabry disease

A series of six full-term placentas and umbilical cords were examined using the in situ detection of globotriaosylceramide (Gb3Cer), GM1 ganglioside (GM1), GM3 ganglioside (GM3), cholesterol and caveolin 1. Immunohistochemical study showed uniform distinct staining of the apical membrane of villous capillary endothelial cells for Gb3Cer, GM1, GM3 and cholesterol. There was also a strong signal for caveolin 1. The immunophenotype suggests the presence of caveola-associated raft microdomains. The immunophenotype was almost completely shared with the extravillous intravascular trophoblast in the basal plate. It was absent in the endothelial cells of umbilical vessels and in the capillaries of somatic structures (heart, lung, skeletal muscle and skin) in neonates as well as in adults, including capillaries of the proliferative endometrium. Results of in situ analyses were confirmed by lipid chromatographic analysis of tissue homogenates and by tandem mass spectrometry. Lysosomal Gb3Cer turnover was followed in three placentas including umbilical cords from Fabry disease (α-galactosidase A deficiency). Lysosomal storage was restricted to vascular smooth muscle cells and to endothelial cells of umbilical vessels. Placental villous capillary endothelial cells displaying a strong non-lysosomal staining for Gb3Cer were free of lysosomal storage.     

Do Australian graziers have an offset mindset about their farm trees?

Worldwide, the footprint of agriculture is higher than that of any other land use, making the local decisions of millions of farmers a global force for achieving the maintenance of ecosystem services. Biodiversity offsets are increasingly used to attempt to reconcile conflicts between production and conservation. Offset policies operate on the principle of habitat substitutability, but little work has considered whether those targeted by such policies perceive nature that way. For instance, do landholders perceive trees of different arrangements, ages or species to be interchangeable? We used a large-scale landholder survey to understand how graziers manage their farm trees, and whether their beliefs are amenable to substitution. Three natural clusters were found, that: (A) liked a tidy farm but did not differentiate trees by species, age or arrangement; (B) strongly supported the need for diversity in tree cover; and, (C) preferred woodlands and connective strips to sparse trees. Those positions were consistent with their beliefs about the costs and benefits of different arrangements of trees, but were largely inconsistent with their declared tree planting and protection activities. Tree management activities were more easily explained by commodity (pro-woodland graziers (C) were most likely to be cropping) or by career stage and what that meant for time and money resources to do conservation work (contrasting A and B). Offset policies and policy incentives encouraging vegetative heterogeneity would motivate at least these first two clusters, helping to sustain a diversity of tree cover and thus ecosystem services on farms.     

Generation and exploration of new classes of antitubercular agents: The optimization of oxazolines, oxazoles, thiazolines, thiazoles to imidazo[1,2-a]pyridines and isomeric 5,6-fused scaffolds

Tuberculosis (TB) is a devastating disease resulting in a death every 20s. Thus, new drugs are urgently needed. Herein we report ten classes of compounds-oxazoline, oxazole, thiazoline, thiazole, pyrazole, pyridine, isoxazole, imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine and imidazo[1,2-c]pyrimidine-which have good (micromolar) to excellent (sub-micromolar) antitubercular potency. The 5,6-fused heteroaromatic compounds were the most potent with MIC's as low as <0.195 μM (9 and 11). Overall, the imidazo[1,2-a]pyridine class was determined to be most promising, with potency similar to isoniazid and PA-824 against replicating Mtb H(37)Rv, clinically relevant drug sensitive, multi- and extensively resistant Mtb strains as well as having good in vitro metabolic stability.     

Solid-phase synthesis of 2'-hydroxychalcones. Effects on cell growth inhibition, cell cycle and apoptosis of human tumor cell lines

Thirty-one 2'-hydroxychalcones were prepared via solid-phase synthesis by base-catalyzed aldol condensation of substituted 2'-hydroxyacetophenones and benzaldehydes. Chalcones were tested for their growth inhibitory activity in three human tumor cell lines (MCF-7, NCI-H460 and A375-C5) using the SRB assay. Results revealed that several of the tested compounds caused a pronounced dose-dependent growth inhibitory effect on the tumor cell lines studied in the low micromolar range. To gain further insight on the cellular mechanism of action of this class of compounds, studies of their effect on cell cycle profile as well as on induction of cellular apoptosis were also carried out. Generally, the tested chalcones interfered with the cell cycle profile and increased the percentage of apoptotic MCF-7 cells. The results here presented may help to identify new chalcone-like structures with optimized cell growth inhibitory activity which may be further tested as potential antitumor agents.