Improving electrical and thermal surface properties of polymer composite materials

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2016-2017, Tutores: Núria Llorca Isern, Ana Maria Escobar RomeroThe use of new composite materials has increase in the last decades due to the possibility to achieve great properties with the combination of two or more materials. A great example is carbon fibre reinforce polymers (CFRPs), which are intensively use in many applications for their good strength to weight ratio. These materials are apparently an ideal component for aircraft industrial; however, the electrical and thermal conductivity they exhibit makes it unsuitable for certain applications like lightening strike protection. To achieve better performance on CFRPs, it is common to metallise the surface with aluminium, copper or others conductive materials. In this project two different approaches have been compared: joining, with adhesive tape, and coating, with electrochemical deposition and sputtering. The electrical conductivity of the samples, before and after the metallization, has been studied with the 4-probes method and we have studied the influence of thickness on thermal and electrical conductivity

Foxn1 Transcription Factor Regulates Wound Healing of Skin through Promoting Epithelial-Mesenchymal Transition

<div><p>Transcription factors are key molecules that finely tune gene expression in response to injury. We focused on the role of a transcription factor, Foxn1, whose expression is limited to the skin and thymus epithelium. Our previous studies showed that Foxn1 inactivity in nude mice creates a pro-regenerative environment during skin wound healing. To explore the mechanistic role of Foxn1 in the skin wound healing process, we analyzed post-injured skin tissues from Foxn1::Egfp transgenic and C57BL/6 mice with Western Blotting, qRT-PCR, immunofluorescence and flow cytometric assays. Foxn1 expression in non-injured skin localized to the epidermis and hair follicles. Post-injured skin tissues showed an intense Foxn1-eGFP signal at the wound margin and in leading epithelial tongue, where it co-localized with keratin 16, a marker of activated keratinocytes. This data support the concept that suprabasal keratinocytes, expressing Foxn1, are key cells in the process of re-epithelialization. The occurrence of an epithelial-mesenchymal transition (EMT) was confirmed by high levels of Snail1 and Mmp-9 expression as well as through co-localization of vimentin/E-cadherin-positive cells in dermis tissue at four days post-wounding. Involvement of Foxn1 in the EMT process was verified by co-localization of Foxn1-eGFP cells with Snail1 in histological sections. Flow cytometric analysis showed the increase of double positive E-cadherin/N-cadherin cells within Foxn1-eGFP population of post-wounded skin cells isolates, which corroborated histological and gene expression analyses. Together, our findings indicate that Foxn1 acts as regulator of the skin wound healing process through engagement in re-epithelization and possible involvement in scar formation due to Foxn1 activity during the EMT process.</p></div

The analysis of requirements on social workers of the International Code of Ethics

This thesis deals with The International Code of Ethics of Social Work. The first part focuses on the origins, history, updates and criticism of ethical codes. It is followed by the analysis of various principles of the International Code of Ethics. This analysis was based on the scientific literature of social work and the articles published in the Czech Republic. Subsequently, for each principle the results of the research among social workers in the South Region were processed. They reveal how social workers perceive the different principles. The analysis is concluded with a brief insight into the ethical theories

Fluorescent detection of Foxn1-eGFP and EMT markers during skin wound healing process in Foxn1::Egfp mice.

<p>Foxn1-eGFP and Snail1 fluorescent detection at days: 2 (A), 4 (B), and 6 (C). Foxn1-eGFP and Mmp-9 fluorescent detection at days: 2 (D), 4 (E), and 6 (F). Nuclei were counterstained with DAPI. hf–hair follicle; e–epidermis; wm–wound margin; arrows–Snail1 positive cells in dermis; insets show higher magnification. Scale bar 50 μm (A-C), 100 μm (D-F).</p

Flow cytometry analysis of cells isolated from post-injured and uninjured skin area of Foxn1::eGFP mice at post-wounded day 5^th.

<p>(A) Representative FACS histograms show detection of Foxn1-eGFP-positive populations of cells from injured skin of Foxn1::Egfp (black) and B6 (grey) mice. (C) Foxn1-eGFP-positive population of cells in uninjured versus injured skin samples. (B, D) Analysis of E-cadherin and N-cadherin positive cells within Foxn1-eGFP population. Data represents mean ± SEM; n = 6.</p

Immunofluorescent detection of EMT traits during the skin wound healing process in B6 mice.

<p>Confocal microscopy imaging (A and A’) of co-localization of E-cadherin and vimentin-positive cells at day 6 after injury; insets provide its higher magnification. Immunostaining for Snali1 and Col IV were detected at post-wounded days: 2 (B), 3 (C), 4 (D), and 5 (E); nuclei were counterstained with DAPI. hf–hair follicle; e–epidermis; d–dermis; wm–wound margin; bm/arrows at B, D and E–basement membrane; arrowheads–Snail1 positive cells between fragmented basement membrane. Scale bar 20 μm (A-A’), 50 μm (E) and 100 μm (B-D).</p

Macroscopic and microscopic evaluation of the skin wound healing process in Foxn1::eGFP and B6 mice.

<p>(A) Representative macroscopic views of skin wounds at days 1–7 and 14 after wounding. (B) The morphometrical analysis of the wound closure areas. (C) Representative histological sections of post-wounded skin area of B6 mice at day 3 (hematoxylin and eosin staining; (HE)); scale bar 500 μm. (D) The comparison of time-course of re-epithelialization process between Foxn1::Egfp and B6 mice. wm—wound margin; ne–newly formed epithelium delineated by dotted line. Values are the mean ± SEM; *p<0.05; ***p<0.001.</p

Foxn1-eGFP protein expression during the time course of skin wound healing in Foxn1::Egfp mice.

<p>(A) Densitometric analysis of eGFP protein from n = 43 Foxn1::Egfp mice, with n = 4–6 single skin samples per time point. (B) Representative Western blot analysis of Foxn1-eGFP protein expression in skin tissues collected from Foxn1::Egfp mice Values are the mean ± SEM; ** p<0.01; *** p<0.001).</p

Foxn1 expression in keratinocytes is stimulated by hypoxia: further evidence of its role in skin wound healing

Abstract Recent studies have shown that the transcription factor Foxn1, which is expressed in keratinocytes, is involved in the skin wound healing process, yet how Foxn1 functions remains largely unknown. Our latest data indicate that Foxn1 drives skin healing via engagement in re-epithelization and the epithelial-mesenchymal transition (EMT) process. In the present study, 2D-DIGE proteomic profiling analysis of in vitro cultured keratinocytes transfected with adenoviral vector carrying Foxn1-GFP or GFP alone (control) revealed forty proteins with differential abundance between the compared groups. Among the proteins with Foxn1-dependent expression, several enable adaptation to hypoxia. Subsequent experiments revealed that hypoxic conditions (1% O2) stimulate endogenous and exogenous (transfected Ad-Foxn1) Foxn1 expression in cultured keratinocytes. A proteomics analysis also identified proteins that can act as a factors controlling the balance between cell proliferation, differentiation and apoptosis in response to Foxn1. We also showed that in C57BL/6 keratinocytes, the stimulation of Foxn1 by hypoxia is accompanied by increases in Mmp-9 expression. These data corroborate the detected co-localization of Foxn1 and Mmp-9 expression in vivo in post-wounding skin samples of Foxn1::Egfp transgenic mice. Together, our data indicate that Foxn1 orchestrates cellular changes in keratinocytes in both physiological (self-renewal) and pathological (skin wound healing) contexts