The spontaneous formation of chiral structures offers a variety of liquid crystals (LC) phases that could be further tailored for practical applications. In our work, the characteristic features of spiral ordering in the cholesteric phase of EZL10/10 LC were evaluated. To disclose resonant reflections related to a nanoscale helix pitch, resonant soft X-ray scattering at the carbon K edge was employed. The angular positions of the observed element-specific scattering peaks reveal a half-pitch of the spiral ordering p/2 ≈ 52 nm indicating the full pitch of about 104 nm at room temperature. The broadening of the peaks points to a presence of coherently scattering finite-size domains formed by cholesteric spirals with lengths of about five pitches. No scattering peaks were detectable in the EZL10/10 isotropic phase at higher temperatures. The characteristic lengths extracted from the resonant soft X-ray scattering experiment agree well with the periodicity of the surface "fingerprint" pattern observed in the EZL10/10 cholesteric phase by means of atomic force microscopy. The stability of LC molecules under the incident beam was proven by X-ray absorption spectroscopy in transmission geometry.
- Publikační typ
- časopisecké články MeSH
Background and aims: The majority of colorectal cancers arise from detectable adenomatous or serrated lesions. Here we demonstrate how deregulated alternative splicing of CD44 gene in diseased colon mucosa results in downregulation of standard isoform of CD44 gene (CD44s) and upregulation of variant isoform CD44v8-10. Our aim is to show that upregulation of CD44v8-10 isoform is a possible marker of precancerous lesion in human colon. Methods: We analysed pairs of fresh biopsy specimen of large intestine in a cohort of 50 patients. We studied and compared alternative splicing profile of CD44 gene in colon polyps and adjoined healthy colon mucosa. We performed end-point and qRT PCR, western blotting, IHC staining and flow cytometry analyses. Results: We detected more than five-fold overexpression of CD44v8-10 isoform and almost twenty-fold downregulation of standard isoform CD44s in colon polyps compared to adjoined healthy tissue with p = 0.018 and p < 0.001 in a cohort of 50 patients. Our results also show that aberrant splicing of CD44 occurs in both biologically distinct subtypes of colorectal adenoma possibly in ESRP-1 specific manner. Conclusion: 92% of the colon polyp positive patients overexpressed CD44v8-10 isoform in their colon polyps while only 36% of them had positive fecal occult blood test which is currently a standard non-invasive screening technique. Impact: We believe that our results are important for further steps leading to application of CD44v8-10 isoform as a biomarker of colorectal precancerosis in non-invasive detection. Early detection of colon precancerosis means successful prevention of colorectal carcinoma.
- MeSH
- antigeny CD44 genetika metabolismus MeSH
- kolon metabolismus patologie MeSH
- kolorektální nádory diagnóza genetika metabolismus MeSH
- lidé MeSH
- nádorové biomarkery genetika metabolismus MeSH
- polypy tlustého střeva metabolismus patologie MeSH
- prognóza MeSH
- protein - isoformy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The goal of our study is to design BaTiO3 ferroelectric layers that will cover metal implants and provide improved osseointegration. We synthesized ferroelectric BaTiO3 layers on Pt/fused silica substrates, and we studied their physical and bio-properties. BaTiO3 and Pt layers were prepared using KrF excimer laser ablation at substrate temperature Ts in the range from 200°C to 750°C in vacuum or under oxygen pressure of 10 Pa, 15 Pa, and 20 Pa. The BaTiO3/Pt and Pt layers adhered well to the substrates. BaTiO3 films of crystallite size 60-140 nm were fabricated. Ferroelectric loops were measured and ferroelectricity was also confirmed using Raman scattering measurements. Results of atomic force microscopy topology and the X-ray diffraction structure of the BaTiO3/Pt/fused silica multilayers are presented. The adhesion, viability, growth, and osteogenic differentiation of human osteoblast-like Saos-2 cells were also studied. On days 1, 3, and 7 after seeding, the lowest cell numbers were found on non-ferroelectric BaTiO3, while the values on ferroelectric BaTiO3, on non-annealed and annealed Pt interlayers, and on the control tissue culture polystyrene dishes and microscopic glass slides were similar, and were usually significantly higher than on non-ferroelectric BaTiO3. A similar trend was observed for the intensity of the fluorescence of alkaline phosphatase, a medium-term marker of osteogenic differentiation, and of osteocalcin, a late marker of osteogenic differentiation. At the same time, the cell viability, tested on day 1 after seeding, was very high on all tested samples, reaching 93-99%. Ferroelectric BaTiO3 films deposited on metallic bone implants through a Pt interlayer can therefore markedly improve the osseointegration of these implants in comparison with non-ferroelectric BaTiO3 films.
- MeSH
- buněčné linie MeSH
- elektřina MeSH
- kostní náhrady chemie MeSH
- lasery MeSH
- lidé MeSH
- nanočástice chemie ultrastruktura MeSH
- osteoblasty cytologie MeSH
- osteogeneze MeSH
- oxid křemičitý chemie MeSH
- platina chemie MeSH
- protézy a implantáty MeSH
- sloučeniny barya chemie MeSH
- titan chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
