Permeation, Solubility, Diffusion and Segregation of Lithium in Amorphous Silicon Layers

The permeation, solubility, diffusion and segregation of lithium in amorphous silicon layers (∼100 nm) were experimentally determined at temperatures up to 500 °C (773 K). For the experiments, silicon was embedded between ⁶Li and ⁷Li enriched solid state Li reservoir layers and the exchange of the isotopes was monitored by secondary ion mass spectrometry. The silicon layers effectively block Li permeation for more than four years at room temperature. At higher temperatures, a fast and a slow Li permeation process can be discriminated. The activation enthalpy for the two processes amounts to (0.9 ± 0.2) and (1.9 ± 0.2) eV, respectively. The first process is based on fast interstitial diffusion leading to Li segregation at the surface and at the substrate interface. The second slower process is due to trap-limited Li diffusion in silicon. An activation enthalpy of Li solubility of (0.5 ± 0.1) eV is found to be identical to that in crystalline silicon, even if absolute values are higher. The activation enthalpy of trap-limited diffusion is determined to be (1.5 ± 0.2) eV. The results are discussed in framework of literature with impact on the lithiation mechanism of silicon electrodes in lithium-ion batteries

Table_1_Farming system effects on root rot pathogen complex and yield of faba bean (vicia faba) in Germany.xlsx

A survey across Germany was undertaken from 2016-2019 to evaluate effects of management system (organic vs conventional), pedo-climatic conditions and crop rotation history on faba bean root health status, diversity of major root rot pathogens and yield. Root rot incidence was generally low and there was no effect of the management system on the spectrum of pathogens isolated. Among the most common fungal species identified, frequencies of Fusarium redolens and Didymella pinodella were significantly higher in roots from organic fields compared with conventional and lower was observed for F. avenaceum, F. tricinctum and F. culmorum. Faba bean roots were colonized at similar rates by F. equiseti and the members of the F. oxysporum (FOSC) and F. solani (FSSC) species complexes in both management systems. Almost no legumes had been grown in the 5-11 years preceding the conventional faba beans surveyed while legumes had almost always been present during this period in the organic fields. This difference in rotational histories between the farming systems led to apparent cropping systems effects on the isolation frequencies of several species. For example, D. pinodella was ubiquitous in organic fields with a high frequency of legumes in the rotations but much rarer and often absent in conventional fields. Pedo-climatic conditions, particularly cool conditions at sowing and plant emergence and/or during the vegetative season favored most of the most prevalent Fusarium species identified in this study. In organic systems, yields correlated negatively with D. pinodella and F. redolens frequencies whereas higher levels of F. tricintum in faba bean roots had a positive correlation with yield. In conventional systems, faba bean yields depended more on the total precipitation before sowing and during the main growing season but were also negatively correlated with the frequencies of FOSC and F. culmorum. Phylogenetic analysis based on the TEF1 alpha locus indicated that the FSSC isolates mainly belonged to the F. pisi lineage. In contrast, the FOSC isolates were placed in 9 different lineages, with a conspicuous dominance of F. libertatis that has until now not been associated with any leguminous host.</p

Phagocytosis.

<p>Primary RPE cells were stimulated with 100 µg/ml fucoidan for 1 hour. RPE cells were exposed to FITC-labeled, photoreceptor outer segment opsonized beads for 4 hours and uptake of the beads was evaluated in fluorescence microscope. No influence of fucoidan on RPE phagocytosis was found. A) control, B) fucoidan, C) quantification of uptaken beads. Significance was determined with student's t-test.</p

Angiogenesis.

<p>(A) Morphological appearance of OEC grown on Matrigel and stained with Calcein-AM which is converted to a green fluorescence by viable cells. Results indicated angiogenic structures in OEC treated with conditioned medium from RPE cells from different donors, VEGF and the EGM-2 (no VEGF). Additional treatment with fucoidan resulted in the reduction of vascular structures. (B) Quantitative image analysis depicting the skeleton length of angiogenic structures. Significance was determined with student's t-test, ++ p<0.01.</p

Wound healing.

<p>A wound was scratched in a confluent cell layer of primary porcine RPE cells and ARPE-19 cells. Cells were either untreated (control) or exposed to fucoidan (100 µg/ml) for 24 hours. Exemplary pictures of wound healing are depicted for primary RPE cells (A) and ARPE-19 cells (B). The percentage of coverage after 24 hours of wound healing is depicted in the graphs for primary RPE cells (C) and ARPE-19 cells (D). Fucoidan significantly reduces wound healing in both RPE and ARPE-19 cells. Significance was determined with student's t-test, + p<0.05; +++ p<0.001.</p

VEGF expression in presence of bevacizumab.

<p>ARPE-19 cells were treated with 250 µg/ml bevacizumab and 100 µg/ml fucoidan for 1 day, 5 days and 7 days. Controls cells were treated with bevacizumab only. Western blot for intracellular VEGF (still containing signal peptide) depicted a reduction of VEGF165 in Western blot at day 5 and day 7 (A), which was significant in densitrometric evaluation (B). Significance was determined with student's t-test, + p<0.05; +++ p<0.001. beva  =  bevacizumab, fuco  =  fucoidan.</p

VEGF165 expression.

<p>Primary RPE cells (A) and ARPE-19 cells (B) were treated with 100 µg/ml fucoidan for 24 hours and the expression of intracellular VEGF (still containing signal peptide) was evaluated using immunocytochemistry. Cells treated with fucoidan exhibited a substantial decrease in intracellular VEGF expression.</p

Validation of growth condition-associated subcellular localization of ADRBK1.

<p>ADRBK1-YFP fusion constructs (green signals) were transfected into cultured Panc-1 cells cultured in the absence (A, C) or presence (B, D) of 10% serum. After 24h or 48h of incubation, cells were fixed and counterstained with DAPI (blue signals). After 24h, ADRBK1-YFP signals were detectable in both, cytoplasm and nuclei, of cells cultured without serum (A), while nuclei of cells cultured with serum were devoid of YFP fluorescence (B). In contrast, after 48h of incubation, cells grown under either condition showed prominent staining of nuclei (C, D). Optical sections of fluorescent images were obtained using the ApoTome technology. Original magnifications are indicated in the images.</p

Inhibition of endogeneous ADRBK1 expression impairs cell growth.

<p>A: Transfection of three individual siRNAs against ADRBK1 resulted in at least 70% reduction of ADRBK1 mRNA levels in two pancreatic cancer cell lines with high (S2-28) and intermediate (PaTu-8988t) levels of endogeneous ADRBK1 expression, as well as the non-transformed HEK293 cell line. mRNA levels were determined by qRT-PCR and normalized to non-silencing control siRNA (“siControl”). B: MTT assays showed significantly reduced numbers of viable cells 72h after transfection of ADRBK1-specific siRNAs as compared to non-silencing control siRNA. C: PI-staining and flow cytometry analyses were performed 48h after siRNA transfection into PaTu 8988t cells. The results demonstrate strongly increased proportions of cells in G1 phase and strongly decreased proportions of cells in S phase after ADRBK1 knockdown, while G2 phase remained essentially unchanged. Shown is one representative example of three independent experiments.E, F: PARP cleavage was analyzed by Western Blot analyses 72h after transfection of ADRBK1-specific and control siRNAs, respectively. The results showed slightly elevated levels of cleaved PARP protein in S2-028 cells (E, right panel), but this was not apparent in PaRu-8988t (E, left panel) or HEK293 (F) cells. * p<0.05, ** p<0.01 (Student’s t-test).</p

VEGF secretion.

<p>VEGF secretion was investigated in RPE/choroid organ culture (A) and ARPE-19 cell culture (B). RPE/choroid perfusion organ cultures were treated with 100 µg/ml fucoidan for 3 days and supernatant was collected at 6 hours, 24 hours and 3 days for one hour. ARPE-19 cells were treated with 100 µg/ml fucoidan for five days, and medium was collected after 1 day, 3 days and 5 days. VEGF content was evaluated with ELISA. Fucoidan reduced VEGF content compared to control in organ culture after 24 hours and 3 days (A). In cell culture, a reduction of VEGF secretion can be found after 3 days and 5 days (B). Significance was determined with student's t-test, + p<0.05; ++ p<0.01.</p