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Published: 12 May 2023

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1

Sanchez, Washington. "Modulation of the SHBG signalling axis." Queensland University of Technology, 2009. http://eprints.qut.edu.au/28604/.

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Sex hormone-binding globulin (SHBG) is a homodimeric plasma glycoprotein that is the major sex steroid carrier-protein in the bloodstream and functions also as a key regulator of steroid bioavailability within target tissues, such as the prostate. Additionally, SHBG binds to prostatic cell membranes via the putative and unidentified SHBG receptor (RSHBG), activating a signal transduction pathway implicated in stimulating both proliferation and expression of prostate specific antigen (PSA) in prostate cell lines in vitro. A yeast-two hybrid assay suggested an interaction between SHBG and kallikrein-related protease (KLK) 4, which is a serine protease implicated in the progression of prostate cancer. The potential interaction between these two proteins was investigated in this PhD thesis to determine whether SHBG is a proteolytic substrate of KLK4 and other members of the KLK family including KLK3/PSA, KLK7 and KLK14. Furthermore, the effects from SHBG proteolytic degradation on SHBG-regulated steroid bioavailability and the activation of the putative RSHBG signal transduction pathway were examined in the LNCaP prostate cancer cell line. SHBG was found to be a proteolytic substrate of the trypsin-like KLK4 and KLK14 in vitro, yielding several proteolysis fragments. Both chymotrypsin-like PSA and KLK7 displayed insignificant proteolytic activity against SHBG. The kinetic parameters of SHBG proteolysis by KLK4 and KLK14 demonstrate a strong enzyme-substrate binding capacity, possessing a Km of 1.2 ± 0.7 µM and 2.1 ± 0.6 µM respectively. The catalytic efficiencies (kcat/Km) of KLK4 and KLK14 proteolysis of SHBG were 1.6 x 104 M-1s-1 and 3.8 x 104 M-1s-1 respectively, which were comparable to parameters previously reported for peptide substrates. N-terminal sequencing of the fragments revealed cleavage near the junction of the N- and C-terminal laminin globulin-like (G-like) domains of SHBG, resulting in the division of the two globulins and ultimately the full degradation of these fragments by KLK4 and KLK14 over time. Proteolytic fragments that may retain steroid binding were rapidly degraded by both proteases, while fragments containing residues beyond the steroid binding pocket were less degraded over the same period of time. Degradation of SHBG was inhibited by the divalent metal cations calcium and zinc for KLK4, and calcium, zinc and magnesium for KLK14. The human secreted serine protease inhibitors (serpins), α1-antitrypsin and α2-antiplasmin, inhibited KLK4 and KLK14 proteolysis of SHBG; α1-antichymotrypsin inhibited KLK4 but not KLK14 activity. The inhibition by these serpins was comparable and in some cases more effective than general trypsin protease inhibitors such as aprotinin and phenylmethanesulfonyl fluoride (PMSF). The binding of 5α-dihydrotestosterone (DHT) to SHBG modulated interactions with KLK4 and KLK14. Steroid-free SHBG was more readily digested by both enzymes than DHT-bound SHBG. Moreover, a binding interaction exists between SHBG and pro-KLK4 and pro-KLK14, with DHT strengthening the binding to pro-KLK4 only. The inhibition of androgen uptake by cultured prostate cancer cells, mediated by SHBG steroid-binding, was examined to assess whether SHBG proteolysis by KLK4 and KLK14 modulated this process. Proteolytic digestion eliminated the ability of SHBG to inhibit the uptake of DHT from conditioned media into LNCaP cells. Therefore, the proteolysis of SHBG by KLK4 and KLK14 increased steroid bioavailability in vitro, leading to an increased uptake of androgens by prostate cancer cells. Interestingly, different transcriptional responses of PSA and KLK2, which are androgen-regulated genes, to DHT-bounsd SHBG treatment were observed between low and high passage number LNCaP cells (lpLNCaP and hpLNCaP respectively). HpLNCaP cells treated with DHT-bound SHBG demonstrated a significant synergistic upregulation of PSA and KLK2 above DHT or SHBG treatment alone, which is similar to previously reported downstream responses from RSHBG-mediated signaling activation. As this result was not seen in lpLNCaP cells, only hpLNCaP cells were further investigated to examine the modulation of potential RSHBG activity by KLK4 and KLK14 proteolysis of SHBG. Contrary to reported results, no increase in intracellular cAMP was observed in hpLNCaP cells when treated with SHBG in the presence and absence of either DHT or estradiol. As a result, the modulation of RSHBG-mediated signaling activation could not be determined. Finally, the identification of the RSHBG from both breast (MCF-7) and prostate cancer (LNCaP) cell lines was attempted. Fluorescently labeled peptides corresponding to the putative receptor binding domain (RBD) of SHBG were shown to be internalized by MCF-7 cells. Crosslinking of the RBD peptide to the cell surfaces of both MCF-7 and LNCaP cells, demonstrated the interaction of the peptide with several targets. These targets were then captured using RBD peptides synthesized onto a hydrophilic scaffold and analysed by mass spectrometry. The samples captured by the RBD peptide returned statistically significantly matches for cytokeratin 8, 18 and 19 as well as microtubule-actin crosslinking factor 1, which may indicate a novel interaction between SHBG and these proteins, but ultimately failed to detect a membrane receptor potentially responsible for the putative RSHBG-mediated signaling. This PhD project has reported the proteolytic processing of SHBG by two members of the kallikrein family, KLK4 and KLK14. The effect of SHBG proteolysis by KLK4 and KLK14 on RSHBG-mediated signaling activation was unable to be determined as the reported signal transduction pathway was not activated after treatment with SHBG, in combination with either DHT or estradiol. However, the digestion of SHBG by these two proteases positively regulated androgen bioavailability to prostate cancer cells in vitro. The increased uptake of androgens is deleterious in prostate cancer due to the promotion of proliferation, metastasis, invasion and the inhibition of apoptosis. The increased bioavailability of androgens, from SHBG proteolysis by KLK4 and KLK14, may therefore promote both carcinogenesis and progression of prostate cancer. Finally, this information may contribute to the development of therapeutic treatment strategies for prostate cancer by inhibiting the proteolysis of SHBG, by KLK4 and KLK14, to prevent the increased uptake of androgens by hormone-dependent cancerous tissues.
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2

Sanchez, Washington Yamanda. "Modulation of the SHBG signalling axis." Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/28604/2/Washington_Sanchez_Thesis.pdf.

Full text
Abstract:
Sex hormone-binding globulin (SHBG) is a homodimeric plasma glycoprotein that is the major sex steroid carrier-protein in the bloodstream and functions also as a key regulator of steroid bioavailability within target tissues, such as the prostate. Additionally, SHBG binds to prostatic cell membranes via the putative and unidentified SHBG receptor (RSHBG), activating a signal transduction pathway implicated in stimulating both proliferation and expression of prostate specific antigen (PSA) in prostate cell lines in vitro. A yeast-two hybrid assay suggested an interaction between SHBG and kallikrein-related protease (KLK) 4, which is a serine protease implicated in the progression of prostate cancer. The potential interaction between these two proteins was investigated in this PhD thesis to determine whether SHBG is a proteolytic substrate of KLK4 and other members of the KLK family including KLK3/PSA, KLK7 and KLK14. Furthermore, the effects from SHBG proteolytic degradation on SHBG-regulated steroid bioavailability and the activation of the putative RSHBG signal transduction pathway were examined in the LNCaP prostate cancer cell line. SHBG was found to be a proteolytic substrate of the trypsin-like KLK4 and KLK14 in vitro, yielding several proteolysis fragments. Both chymotrypsin-like PSA and KLK7 displayed insignificant proteolytic activity against SHBG. The kinetic parameters of SHBG proteolysis by KLK4 and KLK14 demonstrate a strong enzyme-substrate binding capacity, possessing a Km of 1.2 ± 0.7 µM and 2.1 ± 0.6 µM respectively. The catalytic efficiencies (kcat/Km) of KLK4 and KLK14 proteolysis of SHBG were 1.6 x 104 M-1s-1 and 3.8 x 104 M-1s-1 respectively, which were comparable to parameters previously reported for peptide substrates. N-terminal sequencing of the fragments revealed cleavage near the junction of the N- and C-terminal laminin globulin-like (G-like) domains of SHBG, resulting in the division of the two globulins and ultimately the full degradation of these fragments by KLK4 and KLK14 over time. Proteolytic fragments that may retain steroid binding were rapidly degraded by both proteases, while fragments containing residues beyond the steroid binding pocket were less degraded over the same period of time. Degradation of SHBG was inhibited by the divalent metal cations calcium and zinc for KLK4, and calcium, zinc and magnesium for KLK14. The human secreted serine protease inhibitors (serpins), α1-antitrypsin and α2-antiplasmin, inhibited KLK4 and KLK14 proteolysis of SHBG; α1-antichymotrypsin inhibited KLK4 but not KLK14 activity. The inhibition by these serpins was comparable and in some cases more effective than general trypsin protease inhibitors such as aprotinin and phenylmethanesulfonyl fluoride (PMSF). The binding of 5α-dihydrotestosterone (DHT) to SHBG modulated interactions with KLK4 and KLK14. Steroid-free SHBG was more readily digested by both enzymes than DHT-bound SHBG. Moreover, a binding interaction exists between SHBG and pro-KLK4 and pro-KLK14, with DHT strengthening the binding to pro-KLK4 only. The inhibition of androgen uptake by cultured prostate cancer cells, mediated by SHBG steroid-binding, was examined to assess whether SHBG proteolysis by KLK4 and KLK14 modulated this process. Proteolytic digestion eliminated the ability of SHBG to inhibit the uptake of DHT from conditioned media into LNCaP cells. Therefore, the proteolysis of SHBG by KLK4 and KLK14 increased steroid bioavailability in vitro, leading to an increased uptake of androgens by prostate cancer cells. Interestingly, different transcriptional responses of PSA and KLK2, which are androgen-regulated genes, to DHT-bounsd SHBG treatment were observed between low and high passage number LNCaP cells (lpLNCaP and hpLNCaP respectively). HpLNCaP cells treated with DHT-bound SHBG demonstrated a significant synergistic upregulation of PSA and KLK2 above DHT or SHBG treatment alone, which is similar to previously reported downstream responses from RSHBG-mediated signaling activation. As this result was not seen in lpLNCaP cells, only hpLNCaP cells were further investigated to examine the modulation of potential RSHBG activity by KLK4 and KLK14 proteolysis of SHBG. Contrary to reported results, no increase in intracellular cAMP was observed in hpLNCaP cells when treated with SHBG in the presence and absence of either DHT or estradiol. As a result, the modulation of RSHBG-mediated signaling activation could not be determined. Finally, the identification of the RSHBG from both breast (MCF-7) and prostate cancer (LNCaP) cell lines was attempted. Fluorescently labeled peptides corresponding to the putative receptor binding domain (RBD) of SHBG were shown to be internalized by MCF-7 cells. Crosslinking of the RBD peptide to the cell surfaces of both MCF-7 and LNCaP cells, demonstrated the interaction of the peptide with several targets. These targets were then captured using RBD peptides synthesized onto a hydrophilic scaffold and analysed by mass spectrometry. The samples captured by the RBD peptide returned statistically significantly matches for cytokeratin 8, 18 and 19 as well as microtubule-actin crosslinking factor 1, which may indicate a novel interaction between SHBG and these proteins, but ultimately failed to detect a membrane receptor potentially responsible for the putative RSHBG-mediated signaling. This PhD project has reported the proteolytic processing of SHBG by two members of the kallikrein family, KLK4 and KLK14. The effect of SHBG proteolysis by KLK4 and KLK14 on RSHBG-mediated signaling activation was unable to be determined as the reported signal transduction pathway was not activated after treatment with SHBG, in combination with either DHT or estradiol. However, the digestion of SHBG by these two proteases positively regulated androgen bioavailability to prostate cancer cells in vitro. The increased uptake of androgens is deleterious in prostate cancer due to the promotion of proliferation, metastasis, invasion and the inhibition of apoptosis. The increased bioavailability of androgens, from SHBG proteolysis by KLK4 and KLK14, may therefore promote both carcinogenesis and progression of prostate cancer. Finally, this information may contribute to the development of therapeutic treatment strategies for prostate cancer by inhibiting the proteolysis of SHBG, by KLK4 and KLK14, to prevent the increased uptake of androgens by hormone-dependent cancerous tissues.
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3

Grishkovskaya, Irina. "Kristallographische Studie zum Sexualhormon-bindenden Globulin (SHBG)." [S.l.] : [s.n.], 2002. http://www.diss.fu-berlin.de/2002/66/index.html.

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4

DUMOULIN, SYLVIE. "Effet des hormones thyroidiennes sur les glycoproteines de transport des steroides, shbg et cbg sur le rapport gbg/shbg." Toulouse 3, 1993. http://www.theses.fr/1993TOU31535.

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5

Aebiacher, Nicholas J. "Aspects of the biology of the shag (Palacrocorax aristotelis)." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/7880/.

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On the Isle of May, Scotland, large numbers of Shags have been marked annually since 1962. From 1981 to 1983, this marked population was sampled to investigate retrospectively a catastrophic decline in numbers of breeding Shags between 1974 and 1976. An electrolytic method was developed to read incomplete ring-numbers on abraded rings: it was 94% successful. The adult annual survival rate before, during and after the decline remained constant at 87%; during the decline, up to 60% of experienced adults refrained from breeding, laying was a month later than usual, chick production and post-fledging survival were both abnormally low. Failure of the fish stocks around the Isle of May probably caused the decline. Dispersal, pair-bond and reproductive performance with respect to age, timing of breeding and nest-site quality were also examined. Natal and breeding fidelity were strong, and more pronounced in males. Second-year males, breeding for the first time, performed half as well as older males; the effects of other male age categories and female age were unimportant. A strong age-independent seasonal decline in breeding performance was attributable to both environmental factors and individual quality. Four nest-site quality criteria affected reproduction: ledge size, dampness, exposure, and vulnerability to the sea. Experienced Shags bred early and occupied good sites; the social structure forced later-breeding recruits onto poorer sites within the breeding group. Shags which changed sites between years preferred those with a previous history of occupation. Sites occupied continuously were of highest quality. The study population currently shows no sign of density-dependent regulation; potential future regulatory factors are food and a shortage of good quality nest-sites.
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6

Hall, Margaret Emily. "Senescence and reproductive performance in the European shag (Phalacrocorax aristotelis)." Thesis, University of Glasgow, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404641.

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7

Jänne, Marja. "Regulation of human sex hormone-binding globulin gene (shbg) expression." Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/mat/bioti/vk/janne/.

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8

King, Ruth. "Bayesian model discrimination in the analysis of capture-recapture and related data." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391229.

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9

Петровський, А. А., and І. О. Товкач. "Модуль захисту авторизації системи «ПОЛІДАР» на основі гібридного алгоритму W-SHAG." Thesis, Cумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/47084.

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10

Podeur, Vincent. "Modélisation expérimentale et numérique du power take-off d’un bassin houlomoteur." Electronic Thesis or Diss., Brest, École nationale supérieure de techniques avancées Bretagne, 2022. http://www.theses.fr/2022ENTA0005.

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Les travaux présentés portent sur l'étude du power take off d'un système houlomoteur. Celui-ci est constitué d'un ensemble de bassins connectés entre eux via des clapets souples assurant une circulation à sens unique. Les mouvements de la plate-forme sur laquelle le système est installé induisent un phénomène de ballottement du fluide présent dans ces bassins. Les vagues ainsi générées viennent alors alimenter une cuve cylindrique dont le fond est percé d'un orifice central. Le fluide injecté dans ce réservoir engendre un écoulement de type tourbillon de vidange, dont l’énergie cinétique est extraite par une turbine à axe vertical. La première phase de ces travaux se concentre sur l'étude expérimentale du tourbillon de vidange en écoulement stationnaire. L'évolution du champ de vitesse dans le bassin, avec et sans turbine, est étudié par particle image velocimetry (PIV). En parallèle, la puissance délivrée par la turbine et la hauteur d'eau dans le bassin sont mesurées. Ces résultats sont utilisés pour définir les hypothèses de départ pour la création d'un modèle numérique. La deuxième phase de ces travaux porte sur l'étude expérimentale du tourbillon de vidange en écoulement instationnaire. Un second dispositif de mesure est spécialement construit et instrumenté. Ce dernier permet de modéliser plus fidèlement l'écoulement rencontré dans le système houlomoteur. La méthode PIV est de nouveau utilisée. La dernière phase des travaux porte sur la modélisation numérique de la turbine à axe vertical. Le modèle développé se fonde sur la théorie des écoulements potentiels et prend en compte les effets 3D. Les résultats obtenus sont comparés aux résultats expérimentaux
The present work aims at studying the power take-off of a wave energy converter (WEC). This system is composed of a set of connected tanks. Rubber flaps are installed at tanks inlet and outlet to ensure a one-way flow direction. Thanks to wave induced motions of the supporting platform, sloshing appears inside the WEC tanks which feed a cylindrical basin with a centered drain hole at its bottom. Then, a bathtub vortex flow appears within this tank, where a vertical axis turbine is installed to harvest kinetic energy from the flow. The first phase of this research focuses on studying the steady bathtub flow. To do so, a dedicated experiment is built. Velocity field within the cylindrical basin, with and without the turbine, is studied via Particle Image Velocimetry (PIV). In addition, power production from the turbine and water level inside the tank are measured. These results are used to define starting hypothesis for developing a numerical model of the turbine. The second phase of this research focuses on studying the unsteady bathtub flow. For this purpose, a second experiment is built. This setup provides a more realistic environment, closer to what can be observed with the WEC system. PIV measurements are also used extensively to study the flow with and without the turbine. The last stage of this research focuses on the numerical modelling of the vertical axis turbine. The model is based on the potential flow theory. First, a two-dimensional approach is used to validate the early pieces of the model. Secondly, a three-dimensional approach is adopted to account for more complex flow features. Finally, numerical and experiment results are compared
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11

Heeg, Bauke. "An electrochemical and SHG study of corrosion inhibition." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625055.

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12

Mausch, Kersten Magdalena. "Pubertätsgynäkomastie Östrogen- und Progesteronrezeptorbestimmung bei Pubertätsgynäkomastie- und Vergleichsgewebe ; pathophysiologische Bedeutung, SHBG, Histologie /." [S.l.] : [s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=960458484.

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13

Janusiewicz, Anna. "A Product of Womanism: Shug Avery in Alice Walker's The Color Purple." Thesis, Högskolan i Gävle, Avdelningen för humaniora, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-19243.

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Feminism in the early 1980's in the United States revolved much around social and cultural matters such as sexual liberation, self- definition and self- realization for women. Derived from these ideas within feminism comes Alice Walker's Womanism, that is the writer's own definition of the strong and independent woman of color. This paper investigates the character Shug Avery, in The ColorPurple (1983), in relation to feminism and Womanism. It is argued that she is an empowered female because of the characteristics and attributes that come along with being a Womanist, despite moral,cultural and societal conditions that indicate marginalization for Shug and all women.
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14

Gebhardt, Philipp. "Kosten-Nutzenanalyse in der SHT (Schädel-Hirn-Trauma) - Diagnostik." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-156917.

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15

Hutchison, J. "Interfacial dynamics of surfactants studied using SHG and ellipsometry." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604860.

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Most conventional techniques for measuring adsorption at the liquid/air interface on fast timescales rely on measuring the change in the interfacial tension as adsorption takes place. This approach works well for solvents such as water, which has a large interfacial tension, but becomes more problematic for less polar solvents such as oil. It is therefore useful to investigate other, more direct, techniques which have the potential to extend the range of systems currently accessible. In this dissertation, Second Harmonic Generation (SHG) and Ellipsometry were applied to the problem of surfactant adsorption at the liquid/air interface, on the millisecond timescale. To measure dynamics on this timescale, SHG and ellipsometry experiments were performed on surfactants adsorbing at the surface of a liquid jet. The principle behind these experiments is that on emergence from the nozzle of the jet, the surfactant surface concentration is not at its equilibrium value and will therefore equilibrate over time. By measuring the surface surfactant concentrations at different distances from the orifice it was therefore possible to obtain a measure of adsorption as a function of time for a given jet speed. In the ellipsometry experiments, the adsorption kinetics of the cationic surfactant, CTAB, were measured. Interpretation of the data was made easier by converting the coefficient of ellipticity directly to a surface concentration using a calibration curve obtained from neutron reflection data. The experimental data obtained were compared with theoretical models for diffusion limited adsoprtion and found to give good agreement. In the SHG experiments, a number of systems were studied, including Nitrophenol, Triton X-100 and the Alkyl-Anilines. For each system, the SHG signal was found to be invariant with time and possible reasons for this finding are discussed in each case.
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16

Moore, Sam S. B. Massachusetts Institute of Technology. "Implementation of side-fringe locking in an SHG cavity." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105652.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2016.
Pages 36-39 are missing. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 40-41).
An alternative method for locking a second-harmonic generation (SHG) cavity on resonance is described and implemented. The usual method, Pound-Drever-Hall locking, is prone to long-term power fluctuations from power variations in the incident laser. When using the second harmonic field for squeezing, these power fluctuations need to be stabilized with an additional control loop (usually a Mach-Zender interferometer). The alternative method, side-fringe locking, involves a simple DC offset on the second-harmonic signal at the desired power to generate the error signal. This thesis demonstrates the insensitivity of side-fringe locking to such long-term power fluctuations and that the noise spectrum is comparable to PDH locking-explained largely due to PZT noise length fluctuations off-resonance..
by Sam Moore.
S.B.
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17

Sáez, López Cristina. "Mecanismos moleculares que regulan la expresión de la shbg: implicaciones en la obesidad." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/392712.

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La proteína transportadora de esteroides sexuales (SHBG) se sintetiza en el hígado humano y es secretada a la sangre, donde une con gran afinidad andrógenos y estrógenos, regulando su biodisponibilidad y accesibilidad a nivel de tejido. Los niveles plasmáticos de SHBG se encuentran bajos en personas obesas de todas las edades y se correlacionan negativamente con el índice de masa muscular. Además de la obesidad, los niveles plasmáticos de SHBG se encuentran bajos en otras patologías metabólicas como diabetes tipo 2 (DT2), hígado graso no alcohólico (NAFLD) y predicen el riesgo de desarrollar enfermedad cardiovascular (EC). Durante esta tesis, nos hemos centrado por un lado en describir los mecanismos moleculares que regulan la expresión de la SHBG durante el desarrollo de la obesidad, mediante la generación de un nuevo modelo de ratón transgénico. También hemos buscado nuevos factores que regulan la producción de SHBG y hemos estudiado los mecanismos moleculares asociados. Finalmente, hemos estudiado si la SHBG juega un papel en el desarrollo y evolución de la obesidad y NAFLD, una de sus patologías asociadas. En primer lugar, mediante el desarrollo de un ratón doble transgénico diabético y obeso que expresa SHBG (SHBG-db/db), hemos observado que a nivel hepático el aumento de PPARγ y la disminución de HNF-4α son responsables de la reducción de los niveles de SHBG que ocurre durante el desarrollo de la obesidad. Por otro lado, mediante este modelo de ratón SHBG-db/db, que presenta NAFLD, y otro modelo de NAFLD inducida con dieta rica en fructosa hemos demostrado que la sobreexpresión de SHBG disminuye la lipogénesis hepática y les protege frente al desarrollo de hígado graso. Utilizando células HepG2 como modelo in vitro, hemos comprobado que la modulación de los niveles de SHBG afecta a la lipogénesis. Por tanto, la disminución de SHBG en pacientes con NAFLD jugaría un papel en el desarrollo de esta enfermedad. Por otro lado, hemos encontrado nuevos factores que regulan la producción de SHBG: la adiponectina como factor metabólico y el ácido oleico como factor nutricional, y hemos descrito los mecanismos moleculares asociados a esta regulación. En el caso de la adiponectina, dadas las correlaciones positivas existentes entre los niveles plasmáticos de adiponectina y de SHBG, y que ambas se encuentran disminuidas en pacientes obesos, hemos estudiado si esta relación es causal. Utilizando células HepG2 hemos encontrado que la adiponectina aumenta la expresión hepática de SHBG mediante la activación de AMPK, que produce un aumento en la oxidación de ácidos grasos y una disminución en la lipogénesis, lo que provoca un incremento en los niveles hepáticos de HNF-4α, activando la expresión de la SHBG. Además en biopsias hepáticas y plasma humano, se comprobó la correlación existente entre los niveles de adiponectina con SHBG y HNF-4α. Por su parte, el estudio de la regulación de SHBG por ácido oleico parte de que los niveles bajos de SHBG constituyen un riesgo independiente de sufrir EC, y el consumo de aceite de oliva, rico en ácido oleico, protege frente al desarrollo de la misma. Por tanto, planteamos si el efecto cardioprotector del aceite de oliva viene mediado en parte por un aumento en la SHBG. En colaboración con el grupo de Endocrinología del hospital Carlos Haya (Málaga) en el marco del estudio PIZARRA, observamos que el consumo de aceite de oliva aumentó los niveles plasmáticos de SHBG en hombres. En células HepG2, comprobamos que se produce este incremento y demostramos que es consecuencia de una disminución del PPARγ hepático inducida por el ácido oleico.
Sex Hormone-Binding Globulin (SHBG) is synthesized by human liver and secreted into the blood, where it binds with high affinity androgens and estrogens, regulating their bioavailability and accesibility at tissue level. SHBG levels are low in obese people of all age and are negatively correlated with body mass index. Besides obesity, plasma SHBG levels are low in other metabolic pathologies such as type 2 diabetes, non-alcoholic fatty liver disease (NAFLD) and predict the risk of cardiovascular disease (CVD). In this thesis, we have described the molecular mechanisms that regulate SHBG expression during obesity development through the generation of a new transgenic mouse model. Besides, we have searched for new factors that regulate SHBG production and the molecular mechanisms involved have been studied. Finally, we have studied whether SHBG plays a role in the development and progression of NAFLD, one of the obesity-related pathologies. In the first place, through the development of a double transgenic mouse model which is obese and diabetic and that expresses SHBG (SHBG-db/db mouse), we have observed that at hepatic level, PPARγ upregulation and HNF-4α downregulation are responsible for the decrease in SHBG levels during obesity development. Besides, by using this SHBG-db/db mouse model, which presents NAFLD, and a NAFLD model induced by high fructose diet, we have demonstrated that SHBG overexpression downregulates hepatic lipogenesis and protects them against fatty liver development. By the use of the cell line HepG2 as in vitro model, we have confirmed that the modulation of SHBG levels affects lipogenesis. We have concluded that SHBG reduction in NAFLD patients would play a role in the development of this disease. In the second place, we have found new factors that regulate SHBG production: adiponectin as metabolic factor and oleic acid as nutritional factor, and we have described the molecular mechanisms involved in such regulation. In the case of adiponectin, given the positive correlations between SHBG and adiponectin plasma levels, and that their levels are decreased in obese patients, we have studied whether this relation is causal. By the use of HepG2 cells, we have found that adiponectin increases SHBG hepatic expression through the activation of AMPK, which produces an increase in fatty acid oxidation and a decrease in lipogenesis, giving rise to an increase of HNF-4α hepatic levels, thus activating SHBG expression. Furthermore, in hepatic biopsies and human plasma, the correlation between adiponectin levels and SHBG and HNF-4α was confirmed. On the other hand, the study of SHBG regulation by oleic acid originates from the fact that low SHBG plasma levels constitute an independent indicator of CVD risk, and olive oil consumption, rich in oleic acid, protects against the development of CVD. Because of this, our objective was to investigate whether the cardioprotective effect of olive oil is mediated in part by SHBG increase. In colaboration with the Endocrinology and Nutrition Group from Carlos Haya Hospital (Málaga) in the frame of the study PIZARRA, we observed that olive oil consumption increased plasma SHBG levels in men. In HepG2 cells, this increment was confirmed and it was demonstrated that it is due to PPARγ downregulation induced by oleic acid.
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18

杜偉麒 and Wai-ki Alex Tu. "Molecular cloning and characterization of rabbit sex hormone binding globulin (SHBG) complementary DNA." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31213716.

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19

Daunt, Francis H. J. "The effects of parental age on reproductive performance in the shag Phalacrocorax aristotelis." Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340330.

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20

Tu, Wai-ki Alex. "Molecular cloning and characterization of rabbit sex hormone binding globulin (SHBG) complementary DNA /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14786965.

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21

Grist, Hannah. "Patterns and consequences of variation in winter location in a partially migratory population of European shags." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=225313.

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22

Santos, Carla Sofia Veríssimo Duarte dos. "A formação em SHT vs. sinistralidade laboral na limpeza urbana." Master's thesis, Escola Superior de Ciências Empresariais, 2013. http://hdl.handle.net/10400.26/4432.

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Dissertação de Mestrado em Segurança e Higiene no Trabalho
O presente estudo tem como objetivo principal identificar a relação entre a formação na área da segurança e higiene do trabalho e a ocorrência de acidentes de trabalho na função de cantoneiro de limpeza, ou seja, perceber se a formação ministrada tem efeitos na diminuição da sinistralidade laboral. Este estudo foi realizado na Câmara Municipal de Lisboa, especificamente na Divisão de Limpeza Urbana, tendo sido utilizada como metodologia, a análise de uma amostra do total de cantoneiros de limpeza, bem como a realização de uma entrevista semiestruturada a elementos da unidade orgânica em questão, com relevância ao nível do processo formativo. Dos resultados obtidos constata-se principalmente que não existe uma relação direta e evidente entre a formação ministrada em SHT aos cantoneiros de limpeza e a sinistralidade laboral nessa função, havendo no entanto outras variáveis que podem contribuir para a ocorrência de acidentes de trabalho. Os resultados obtidos poderão permitir, face ao tema abordado, percecionar a adequabilidade e eficácia do processo formativo em segurança e higiene do trabalho, relativamente à função de cantoneiro de limpeza.
This study's main objective is to identify the relationship between training in safety and hygiene at work and the occurrence of accidents in the function of street cleaning, ie perceiving that the training provided has effects in reducing accidents at work. This study was conducted at the Lisbon City Council, specifically the Division of Urban Cleaning, having been used as a methodology, analysis of a representative sample of the total street cleaners as well as conducting a semistructured interview to elements of the organizational unit in question with relevance to the level of the training process. From the results it is clear that there isn’t a direct and evident relation between the training provided in safety and hygiene at work to street cleaners and work accidents in this role, however there are other variables that may contribute to the occurrence of accidents. The results may allow, given the subject matter, understand the adequacy and effectiveness of the training process in safety and hygiene in relation to the function of street cleaning.
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23

Shephard, Emily Laura Cairns. "Strategies for efficient foraging in a deep-diving bird, the imperial shag (Phalacrocorax atriceps)." Thesis, Swansea University, 2009. https://cronfa.swan.ac.uk/Record/cronfa42298.

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Predators are frequently involved in an arms race with their prey, with improved abilities on one side demanding compensatory improvements on the other. Those that breathe air but forage underwater are faced with the additional challenge of capturing prey in a medium where their own capacity to remain is limited. This thesis examines some of the strategies used by my model organism, the imperial shag (Phalacrocorax atriceps) to enhance its foraging efficiency. I did this by using recent developments in animal-attached technology to measure the patterns and costs of bird behaviour during foraging at a fine-scale. Time appeared to be of the essence for these birds, as their movements were consistent with a strategy to maximise the rate of energy gain. Male and female shags were found to forage at depths where their foraging efficiency was maximised, which manifested itself in the horizontal segregation of male and female foraging areas. Analysis of the mechanical power used underwater suggested that these birds may be limited in the burst speeds they can produce at shallow depths; as the greater the power required to counteract their buoyancy the less is available for prey pursuit. Finally, analysis of the fine-scale tortuosity in the foraging movements of imperial shags revealed that the distribution of their prey was not aggregated at the scales over which they forage. Nevertheless, tortuosity was a good indicator of prey ingestion rates and revealed that shags adjusted their movements to recent prey encounter within both prey-searching and resting phases. This work indicates that imperial shags have an extensive armoury of strategies by which they may increase their efficiency as underwater predators, and methods used and refined in this thesis mean that users are now well-equipped to investigate them.
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24

Ksianzou, Viachaslau. "Second-order nonlinear optical interactions and cascading effects in thinorganic films." Phd thesis, Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4918/.

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The presented work describes new concepts of fast switching elements based on principles of photonics. The waveguides working in visible and infra-red ranges are put in a basis of these elements. And as materials for manufacturing of waveguides the transparent polymers, dopped by molecules of the dyes possessing second order nonlinear-optical properties are proposed. The work shows how nonlinear-optical processes in such structures can be implemented by electro-optical and opto-optical control circuit signals. In this paper we consider the complete cycle of fabrication of several types of integral photonic elements. The theoretical analysis of high-intensity beam propagation in media with second-order optical nonlinearity is performed. Quantitative estimations of necessary conditions of occurrence of the nonlinear-optical phenomena of the second order taking into account properties of used materials are made. The paper describes the various stages of manufacture of the basic structure of the integrated photonics: a planar waveguide. Using the finite element method the structure of the electromagnetic field inside the waveguide in different modes was analysed. A separate part of the work deals with the creation of composite organic materials with high optical nonlinearity. Using the methods of quantum chemistry, the dependence of nonlinear properties of dye molecules from its structure were investigated in details. In addition, the paper discusses various methods of inducing of an optical nonlinearity in dye-doping of polymer films. In the work, for the first time is proposed the use of spatial modulation of nonlinear properties of waveguide according Fibonacci law. This allows involving several different nonlinear optical processes simultaneously. The final part of the work describes various designs of integrated optical modulators and switches constructed of organic nonlinear optical waveguides. A practical design of the optical modulator based on Mach-Zehnder interferometer made by a photolithography on polymer film is presented.
Die vorliegende Arbeit beschreibt neue Konzepte für schnelle photonische Schaltelemente. Diese Elemente basieren auf optischer Wellenleitung im sichtbaren und nahen infraroten Spektralbereich. Die Arbeit ist auf organische Wellenleiter aus transparenten, farbstoffdotierten Polymeren fokussiert, welche Chromophore mit besonders großen optischen Nichtlinearitäten zweiter Ordnung enthalten. Insbesondere wird dargestellt, wie nichtlineare optische Prozesse in derartigen Bauelementen genutzt werden können, wenn man elektrische oder optische Steuersignale einsetzt. Es wird der gesamte Her-stellungszyklus verschiedener integrierter photonischer Bauelemente betrachtet. Die Arbeit umfasst weiterhin eine detaillierte theoretische Analyse der Wellenausbreitung in Medien mit großer nichtlinearer optischer Suszeptibilität zweiter Ordnung bei hoher Lichtintensität. Unter Annahme optischer Materialkonstanten, welche den experimentell ermittelten Werten entsprechen, erfolgte eine quantitative Abschätzung für das Auftreten von Szenarien, bei denen messbare Abwei-chungen der Strahlausbreitung vom linearen Regime auftreten, z:B. das Auftreten von zeitlichen, räumlichen und spektralen Satteliten zu den im Material propagierenden Laserpulsen. Es gelang, we-sentliche Aspekte der Strahlpropagationsprozesse durch Anwendung von Jacobi-Integralfunktionen in geschlossener mathematischer Form darzustellen. Darüber hinausgehende theoretische Untersuchungen nutzten die Finite-Elemente-Methode, um die Verteilung des elektromagnetischen Feldes im Inneren optischer Wellenleiter für verschiedene Pro-pagationsmoden zu analysieren. Ein weiterer Teil der Arbeit beschäftigt sich mit organischen Kompositmaterialen, welche große opti-sche Nichtlinearitäten aufweisen. Mittels quantenchemischer Verfahren erfolgte eine detaillierte Un-tersuchung der Zusammenhänge zwischen der molekularen Struktur und den linearen sowie den nichtlinearen optischen Eigenschaften der untersuchten Farbstoffmoleküle und Polymere. In Bezug auf die Probenpräparation sind unterschiedliche Verfahren zur Schichtbildung und zur molekularen Orientierung miteinander verglichen und bewertet worden, da letztere eine Voraussetzung für das Auftreten nichtlinearer optischer Prozesse zweiter Ordnung bildet. Die Untersuchungen erstreckten sich auf Vakuumaufdampfschichten aus niedermolekularen Chromophoren und auf Polymerschich-ten, welche durch Vakuumabscheidung sowie durch Spincoating oder andere Flüssigphasenabschei-dungsverfahren hergestellt worden sind. Auf orientierenden Substraten (z.B. geriebene Schichten aus Polytetrafluoräthylen) konnte eine spontane Orientierung der deponierten Chromophore nachgewie-sen werden. Die Chromophore in Polymerschichten wurden durch Coronapolung orientiert. In der Arbeit ist zum ersten Mal vorgeschlagen worden, eine räumliche Modulation der nichtlinearen optischen Eigenschaften durch gezielte lokale Coronapolung oder andere Orientierungstechniken derart zu generieren, dass die Abfolge gepolter Domänen dem Bildungsgesetz einer modifizierten Fibonacci-Reihe mit gebrochen rationalen Zahlen gehorcht. Der Vorteil von optischen Wellenleitern mit dieser Struktur darin, dass diese mehrere unterschiedli-che nichtlineare optische Prozesse gleichzeitig unterstützen und somit eine Vielzahl neuartiger Phä-nomene auftreten kann, welche man in neuartigen photonischen Bauelementen, z.B. für die optische Informations- und Kommunikationstechnik nutzen kann. Der letzte Teil der Arbeit beschreibt den Aufbau verschiedener integrierter optischer Modulatoren und Schalter, die sich mit Hilfe das neu entwickelten Verfahrens herstellen lassen. Zukünftige Entwicklungen in der Photonik, insbesondere der optischen Informations- und Kommuni-kationstechnik werden im abschließenden Teil der Arbeit diskutiert.
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25

Vismer, Michael John. "An operational model for estrogenic action in the presence of sex hormone binding globulin (SHBG)." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/19887.

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Thesis (MSc)--University of Stellenbosch, 2007.
ENGLISH ABSTRACT: The aim of this study was to build a mathematical model that describes the binding of 17- -estradiol (E2) to estrogen receptor (ER- ) and the influence the sex hormone binding globulin (SHBG) has on this interaction. The influence of SHBG on the transactivation of an estrogen response element, via ligand bound ER- , was also studied. COS-1 cells, derived from the kidney of a green african monkey, were used to study the binding of E2 to ER- in the absence of SHBG. The influence of SHBG on the binding of E2 to ER- was studied using Hep89 cells, human hepatacoma carcinoma, which express SHBG endogenously and are stably transfected with the ER- gene. Human pregnancy plasma was used to study the interaction of E2 with SHBG in the absence of ER- . The results of this study have shown that the Kd (E2) for ER- was determined as between 3.4nM and 4.4nM in the absence of SHBG. With respect to the binding of E2 to ER- it was not possible to determine the Kd app and Bmax for ER- using the Hep89 experimental system. The Kd (E2) for SHBG was not determined using the human pregnancy plasma experimental system. With the aid of mathematical modelling, a model of the Hep89 and human pregnancy plasma experimental systems, was built. The results of the numerical modelling, using mathematical modelling, showed that the presence of albumin together with SHBG was the reason that the Kd app (E2) could not be determined in the Hep89 experimental system. With respect to the use of human pregnancy plasma to determine the Kd (E2) for SHBG it was shown that if the plasma was diluted 200 times it would have been possible to determine the Kd app (E2) for SHBG, in the presence of albumin. Ligand independent transactivation of an estrogen response element was shown to be a problem in the COS-1 cell system when promoter reporter gene assays were undertaken. As COS-1 cells were used as a control for the absence of SHBG no further promoter reporter gene assays were undertaken using the Hep89 experimental system.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was die bou van ‘n wiskundige model wat die verbinding van E2 met die estrogeenreseptor (ER- ) en die invloed wat die geslagshormoon-verbindingglobulien (SHBG) op hierdie interaksie het, beskryf. Die effek van SHBG op die transaktivering van ‘n estrogeen responselement, via die ligandverbonde ER- , is ook bestudeer. COS-1-selle uit die nier van ‘n groen afrika-aap is gebruik om die verbinding van E2 met ER- in die afwesigheid van SHBG te bestudeer. Die invloed van SHBG op die verbinding van E2 met ER- , is bestudeer deur gebruik te maak van Hep89-selle, die menslike lewergeswelkarsinoom, wat SHBG uitwendig afgee en wat stabiel getransfesteer kan word met die ER- geen. Menslike swangerskapplasma is gebruik om die interaksie van E2 met SHBG in die afwesigheid van ER- te bestudeer. Die uitslag van hierdie studie toon aan dat die Kd (E2) vir ER- vasgestel tussen 3.4nM en 4.4nM in die afwesigheid van SHBG. Met betrekking tot die verbinding van E2 met ER- , was dit nie moontlik om die Kd (E2) en Bmax app vir ER- met die gebruik van die Hep89 eksperimentele stelsel vas te stel nie. Die Kd (E2) vir SHBG is nie vasgestel deur die gebruik van die menslike swangerskapplasma eksperimentele stelsel nie. ‘n Model van die Hep89 en menslike swangerskapplasma eksperimentele stelsels is met behulp van wiskundige modellering gebou. Die uitslag van die numeriese modellering, met gebruik van wiskundige modellering, toon dat die teenwoordigheid van albumien, saam met SHBG, die rede was dat die Kd app (E2) nie in die Hep89 eksperimentele stelsel vasgestel kon word nie. Wat betref die gebruik van menslike swangerskapplasma om die Kd (E2) vir SHBG vas te stel, is daar aangetoon dat, indien die plasma 200 maal verdun was, dit moontlik sou gewees het om die Kd app (E2) vir SHBG in die teenwoordigheid van albumien vas te stel. Promotor verkilkkergeen toetse het ligandonafhanklike transaktiveering van ‘n estrogeen responselement aangetoon as ‘n probleem in die COS-1-selle stelsel. Omdat COS-1-selle gebruik is as ‘n kontrole vir die afwesigheid van SHBG, is geen verdere promotor verkilkkergeen toetse onderneem met die gebruik van die Hep89 eksperimentele stelsel nie.
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26

DE, GLISEZINSKI ISABELLE. "Interet du dosage de la shbg dans l'evaluation du statut nutritionnel chez la personne agee." Toulouse 3, 1993. http://www.theses.fr/1993TOU31555.

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27

Yin, Yan. "Silica Fiber with Large and Thermodynamically Stable Second Order Optical Nonlinearity." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32266.

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In this thesis, we demonstrate, theoretically, that, by depositing a regular fused-silica fiber with optical nonlinear molecules, strong and thermodynamically stable SHG can be obtained. Our experiments also provide strong evidence for the theory. Start from the basic Maxwell equation, we derive the SHG efficiency that the excited power translates into the SHG signal. According to the SHG efficiency equation, a small radius and a long length will help to result in a high SHG efficiency, which also increases with the excited power. We fabricate silica fiber tapers with radius less than 5 μm through either wet etching or heating while stretching. Through improving the stretching setup, and adroitly manipulating both the stretching rate and the heating temperature, we are able to control the taper loss less than 1 dB. Then we dip taper part into cationic solution and anionic solution alternatively to have ISAM/CHISAM film on it. By improving the surface quality of film around a silica fiber taper, we are able to control film loss of PAH/PR film to less than 2 dB for 5 bilayers. We set up a SHG measurement stage for a nonlinear fiber, and develop a measurement method during the experiments. We have shown that by depositing (PAH/PB)10 films around a fiber taper with a diameter around 5 µm, we can obtain high SHG signal. The ratio of the obtained SHG signal to the excitation power for such a nonlinear fiber is more than 10 times of that of a 125 µm single mode fiber with the same length. Our experiment result provides strong evidence that centrosymmetric material can be used as SHG material.
Master of Science
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28

Martínez, Selvas David. "Accions alternatives de la proteïna transportadora d'esteroids sexuals (SHBG/ABP) a l'espermatogènesi i al càncer de pròstata." Doctoral thesis, Universitat Autònoma de Barcelona, 2001. http://hdl.handle.net/10803/3466.

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La finalitat d'aquesta tesi ha estat la d'estudiar les funcions alternatives de la proteïna transportadora d'esteroids sexuals (SHBG/ABP) a l'espermatogènesi i al càncer de pròstata.

1) A l'espermatogènesi s'ha treballat amb dos models diferents, un és el ratolí transgènic que sobreexpressa la SHBG/ABP de rata i l'altre el ratolí transgènic que sobreexpressa la SHBG/ABP humana.
a) Ratolí transgènic per la SHBG/ABP de rata. La sobreexpressió del transgen de rata a nivell del testicle provoca un bloqueig parcial de la primera divisió meiòtica i un augment de la mort cel.lular programada o apoptosi de les cèl.lules germinals, especificament d'espermatocits primaris i cèl.lules en meiosi. Aquestes cèl.lules apoptòtiques sobreexpressen el mRNA i la proteïna del receptor d'estrògens beta. La proteïna, a més a més, s'acumula a nivell del citoplasma d'aquestes cèl.lules apoptòtiques.
b) Ratolí transgènic per la SHBG/ABP humana. El trànscrit que s'expressa a nivell del testicle de la linia shbg11 prové del promotor alternatiu i conté l'exó alternatiu. A més a més, aquest trànscrit l'expressen les cèl.lules germinals . La proteïna SHBG/ABP humana es troba a nivell de l'acrosoma de les cèl.lules germinals durant tota la fase d'elongació de l'espermatogènesi, i a nivell de l'acrosoma dels espermatozous epididimaris.

2) Al càncer de pròstata s'ha treballat amb diferents linies cel.lulars de pròstata i amb mostres de pacients amb càncer de pròstata.
a) Linies cel.lulars de càncer de pròstata. S'ha treballat amb dues linies cel.lulars tumorals com són les PC3 i les LNCaP i dues linies cel.lulars normals com són les CAHVP10 i les PZHVP7. Les linies PC3 i LNCaP sobreexpressen 3 trànscrits que codifiquen per a la SHBG/ABP humana. El trànscrit majoritari dona lloc a la proteïna secretada, mentres que els dos trànscrits que falten els exons 6 i 6-7 respectivament, donen lloc a una proteïna intracel.lular. La diferència entre la linia PC3 (androgen-independent) i la linia LNCaP (androgen-depenent) és que la linia PC3 expressa la isoforma cx del receptor de estrògens beta.
b) Pacients afectats de càncer de pròstata. En 4 dels 6 pacients analitzats s'expressa la SHBG/ABP humana, en 3 d'ells s'expressa el receptor d'estrògens i en tots es sobreexpressa la P450 aromatasa.
La proteïna SHBG/ABP s'acumula a l'interior de les cèl.lules epitelials de les glandules tumorals en les seccions prostàtiques dels pacients analitzats.
The aim of this thesis is to study the alternative funcions of the sex hormone-binding globulin / androgen-binding protein (SHBG/ABP) during the espermatogenesis and prostate cancer.

1) In the study of the espermatogenesis we have used two different models: the transgenic mice overexpressing the rat SHBG/ABP, and the transgenic mice overexpressing the human SHBG/ABP.
a) Transgenic mice overexpressing rat SHBG/ABP. The overexpression of rat SHBG/ABP in the testis induces a parcial arrest of the first meiotic division and an increase of germ cell apoptosis, involving specifically primary spermatocytes and cells at metaphase. The apoptotic cells are overexpressing the mRNA and the protein for the estrogen receptor beta, and the protein acumalates in the citoplasm of this apoptotic cells.
b) Transgenic mice overexpressing human SHBG/ABP. The shbg11 mouse line overexpress the mRNA for the human SHBG/ABP in the testis, and this mRNA contains the alternative exon 1 (exon A). The human mRNA is expressed by germ cells, and the protein is located in the acrosome during all the elongation sattges of spermatogenesis.

2) In the sutdy of the prostate cancer we have used prostatic tumor cell lines (PC3 and LNCaP) and prostatic normal cell lines (CAHVP10 and PZHVP7) and samples from patients with prostate cancer.
a) Prostate cell lines. The tomurogenic cell lines PC3 and LNCaP overexpress three human SHBG/ABP transcripts, most abundant transcript produce secreted human SHBG/ABP protein. The other two transcripts lacking exon 6 and exon 6-7, produce intracelular human SHBG/ABP protein. The main difference between the PC3 cell line (androgen-independent) and the LNCaP cell line (androgen-dependent) is that PC3 cells are express the cx isoform of the estrogen receptor beta.
b) Patients with prostate cancer. Four of the six patients analized express human SHBG/ABP mRNA. Three of them co-express the estrogen receptor beta and all of them express the P450 aromatase.
The human SHBG/ABP protein is located in the epitelial cells from the tumoral glands in all the prostate sections analized from the patients with prostate cancer.
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29

Forges, Thierry. "Etude de l'expression de la sex hormone-binding globulin (SHBG) dans les cellules de la granulosa humaines." Nancy 1, 2004. http://www.theses.fr/2004NAN11310.

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La sex hormone-binding globulin (SHBG), glycoprotéine hépatique, est classiquement considérée comme une protéine de liaison, assurant le transport des stéroïdes sexuels dans le sang et régulant leur biodisponibilité. Cependant, d'autres sites d'expression, ainsi que des récepteurs membranaires spécifiques ont été découverts dans certains tissus. L'interaction de la SHBG avec ces récepteurs déclenche la production d'un second messager et l'apparition d'un effet biologique. Le présent travail a pour but d'étudier l'expression de la SHBG dans les cellules de la granulosa humaines. D'abord, la présence de la protéine a été détectée par immunohistochimie (IHC) dans la granulosa in situ, sur des coupes d'ovaires adultes et fœtaux, et des transcrits de SHBG ont été mis en évidence par RT-PCR dans des extraits d'ovaires. Ensuite, des cellules de la granulosa ont été isolées à partir de liquides folliculaires, obtenus chez des patientes candidates à une fécondation in vitro. A partir de cultures primaires de ces cellules nous avons démontré l'expression de la SHBG in vitro, par IHC et RT-PCR, ainsi que la sécrétion de la protéine dans le milieu de culture, par Western blot. Par cette approche semi- quantitative, certains facteurs régulateurs de l'expression de la SHBG dans ces cellules ont été identifiés, notamment la tri-iodothyronine et l'insuline. Enfin, un effet de la SHBG, en combinaison avec l'œstradiol, sur la production d'adénosine monophosphate cyclique intracellulaire et la sécrétion de progestérone par les cellules de la granulosa a été mis en évidence. Ces résultats suggèrent que la SHBG produite localement joue un rôle dans le fonctionnement folliculaire.
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30

Jasieczek, Christina Bozena. "Investigation of hydrogen bonding and SHG activity of organic salts and co-crystals." Thesis, University of Sussex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318504.

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Schnitzbauer, Andreas. "Ligandbindungsstudien des humanen Steroidhormon-bindenden Globulins in einem Biosensorsystem." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974915815.

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32

Barlow, Emily J. "Ecological and genetic perspectives on dispersal in European shags (Phalacrocorax aristotelis)." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=182248.

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Dispersal is a fundamental ecological and evolutionary process that can create demographic and genetic linkage between neighbouring and distant locations, influencing the dynamics, structure and ultimately the persistence of populations. To understand observed population dynamics and structure and to predict future change, accurate and comprehensive data are required describing the pattern and magnitude of dispersal and gene flow across all relevant spatial scales. However, this is a major empirical challenge. In this thesis, I aimed to obtain comprehensive empirical data quantifying natal dispersal patterns and population genetic structure across multiple spatial scales using the European shag (Phalacrocorax aristotelis) as a model species. I used a combination of field observations of shags individually ringed on the Isle of May, Scotland and molecular genetic techniques to accomplish these aims. By locating adult shags that had been ringed as chicks on the Isle of May at their breeding locations across eastern Scotland, I demonstrated divergent dispersal distributions at small versus large spatial scales. Using both mitochondrial DNA markers and a newly developed set of microsatellite markers, I quantified population genetic structure across a pan-European scale. This was weak across both molecular markers suggesting a role for occasional effective long-distance dispersal. However, a suite of evolutionary forces besides gene flow can create observed population genetic structure. Therefore, I quantified population genetic structure across populations in eastern Scotland, and quantitatively linked this indirect estimate of gene flow with my direct field observations of dispersal. Dispersal parameters derived explicitly from field observations and the spatial organisation of populations were shown to strongly influence observed population genetic structure. Overall, these data demonstrate the need to utilise both field observations and genetic methods to comprehensively estimate the extent and effectiveness of dispersal and highlight the importance of accurately quantifying long-distance dispersal in particular for predicting future change.
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Granroth-Wilding, Hanna Maria Veronica. "Parasitism, family conflict and breeding success." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8243.

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Parasites are important drivers of ecological and evolutionary processes in their hosts. However, hosts often differ in how they are affected by parasitism, which can be important in how parasite effects on individuals scale up to the population level. Hosts may differ intrinsically in their susceptibility to parasitism, and extrinsic factors may impose constraints on how hosts allocate resources between immunity, maintenance and reproduction, thereby further affecting their ability to cope with infection. These extrinsic factors include the host’s ecological environment, for example food availability or weather, and its social environment, that is its interactions with conspecifics. This is particularly true during a reproductive attempt when individuals interact closely with other family members. Not only might immediate impacts of parasitism differ between and within parents and offspring, but the direct effects of parasitism on a host could have further indirect consequences for other family members through their behavioural interactions with parasitised individuals. The distribution of direct and indirect effects among all family members could affect the outcome of the breeding event and individuals’ future performance. However, teasing apart these various avenues of parasite impacts on families may be difficult if parasite burden or susceptibility is correlated between family members. In this thesis, I explore the consequences of parasitism for different family members of the European shag Phalacrocorax aristotelis infected with gastrointestinal nematodes, over a range of ecological conditions. In chapter 2, I demonstrate that chicks’ responses to anti-parasite treatment across four years vary between siblings and with environmental conditions, which may be mediated by resource allocation among siblings. In chapter 3, I explore how costs of parasitism are distributed among the whole family by simultaneously treating chicks and/or parents with an anti-parasite drug and measuring the outcomes for all family members. Treatment has a more marked effect for the non-treated generation than for the treated individuals, suggesting that parasitism may have important indirect costs. In chapter 4, I investigate whether within-brood variability in the effects of anti-parasite treatment and its cross-generational impacts are mediated by behavioural change, and show that chick treatment but not parent treatment influences several aspects of behaviour in the nest. In chapter 5, I demonstrate that the impact of chick anti-parasite treatment on parents persists beyond the breeding attempt, with parents of treated chicks foraging less overwinter and breeding earlier the following year, whereas there is no persistent effect of parents’ own anti-parasite treatment. Lastly, I provide an appendix examining the parasitology of the system in detail, including an assessment of in situ and proxy measures of worm burdens of chicks. This thesis demonstrates that parasitism can be a key component, previously overlooked, of reproductive performance in seabirds, a group that plays an important ecological role as apex predators and thus indicator species of the marine environment.
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34

Laurent, Guillaume. "Mélange d'ondes dans des nano-structures plasmoniques hybrides." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY046/document.

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La nanophotonique non-linéaire offre une opportunité unique pour ouvrir de nouvelles voies vers des applications dans les détecteurs, les ordinateurs et la cryptographie quantique. Cependant, la faiblesse intrinsèque de la réponse non-linéaire des milieux de taille inférieure au micromètres limite fortement l’efficacité des sources optique à cette échelle. Combiner l'exaltation du champ électromagnétique dans les métaux (appelée résonance plasmonique) et l'efficacité non-linéaire de nanocristaux non-centosymétriques apparait extrêmement souhaitable et constitue le cœur de ce projet. Dans ce cadre, le travail présenté dans cette thèse consiste en une approche numérique quantitative des processus linéaires et non-linéaires (génération de second harmonique et de paires de photons) mis en jeu dans les nanostructures hybrides afin de pouvoir « accorder » les résonances plasmoniques et optimiser le couplage lumière-matière. L’étude menée prédit une exaltation par plusieurs ordres de grandeur des processus non linéaires modélisés au sein de particules composites
Nonlinear nanophotonics offers a unique opportunity to open new path toward a wide range of pratical applications in sensors, quantum computers, cryptography devices. The main challenge is to enhance nonlinear response of nanosized particles in order to integrate them in optical components. On this purpose, we want to combine the electromagnetic field enhancement in metals (due to a phenomenon called plasmonic resonances) with non linear efficiency of non centrosymmetric nanocrystals.In this thesis, we present a numerical approach for simulating linear and non linear optical processes (second harmonic generation and spontaneous numerical down conversion) in hybrid nanostructures in order to “ tune “ plasmonic resonances and optimize light/matter coupling. The study predicts an enhancement by several orders of magnitude of the non linear phenomena modeled in composite nano particles
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Limmer, Mark David. "I don't shag dirty girls : the impact of masculinity and social exclusion on young mens' sexual risk-taking." Thesis, Lancaster University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538581.

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36

Steel, William Hobbs. "Investigations of solvent polarity at liquid/liquid interfaces by SHG spectroscopy using molecular rulers." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1371.

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Thesis (Ph. D.)--University of Maryland, College Park, 2004.
Thesis research directed by: Chemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Hohbach, Jan [Verfasser], Sascha [Gutachter] Flohé, and Bernd [Gutachter] Bittersohl. "Das Schwere SHT im Traumanetzwerk der DGU / Jan Hohbach ; Gutachter: Sascha Flohé, Bernd Bittersohl." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2019. http://d-nb.info/1190350750/34.

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38

Damianos, Dimitrios. "Génération de seconde harmonique (SHG) pour la caractérisation des interfaces entre diélectriques et semiconducteurs." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT072/document.

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Cette thèse s’intéresse à une technique de caractérisation particulièrement bien adaptée à l’étude de couches diélectriques ultra-minces sur semiconducteurs. La génération de seconde harmonique (SHG) est une méthode très prometteuse, basée sur l’optique non-linéaire. Un laser est focalisé sur l'échantillon à caractériser et le signal à deux fois la fréquence fondamentale est mesuré. Pour les matériaux centrosymétriques comme c-Si, SiO2 et Al2O3, le signal SHG est dû aux défauts et au champ électrique Edc d’interface (induit par les charges préexistantes Qox et/ou piégées au niveau des pièges d’interface Dit). La SHG donne ainsi accès à la qualité des interfaces entre diélectriques/semiconducteurs. Néanmoins, le signal SHG dépend aussi des phénomènes de propagation optique dans les structures multicouches. Pour cette raison, nous avons développé un programme de simulation qui prend en compte les phénomènes optiques et les champs électriques statiques aux interfaces. Nous avons utilisé la SHG pour analyser la qualité de passivation de structures Al2O3/Si préparées avec des procédés différents et nous avons montré une corrélation entre SHG et mesure de durée de vie des porteurs de charges. Les valeurs de Qox et Dit ont été extraites par des mesures de capacité-tension et elles ont permis de calculer le champ Edc. La simulation optique, avec les valeurs extraites de Edc a permis de reproduire les données expérimentales de SHG dans ces structures. La SHG a été utilisée également pour la caractérisation des substrats Silicium-sur-Isolant (SOI). Pour les structures SOI épaisses, la simulation et les résultats expérimentaux ont montré que la réponse SHG est dominée par les interférences optiques (faible impact de Edc). Pour les structures SOI ultraminces, les interfaces sont couplées électriquement et des valeurs de Edc sont nécessaires pour reproduire les données expérimentales par simulation. Cela implique que pour les SOI ultraminces, la SHG pourrait donner accès aux champs électriques au niveau des interfaces d’une manière non-destructive
This PhD work was developed in the context of research for novel characterization methods for ultra-thin dielectric films on semiconductors and their interfacial quality. Second harmonic generation (SHG) is a very promising non-invasive technique based on nonlinear optics. A laser emitting at the fundamental frequency is incident upon the sample which responds through its 2nd order polarization, generating a signal at twice the fundamental frequency. For centrosymmetric materials such as c-Si, amorphous SiO2 or Al2O3, the SHG signal is mainly due to the defects and to the static electric field Edc present at the interface (due to pre-existing charges Qox and/or photo-injected charge trapping/detrapping at interface traps Dit). Thus, SHG measurement gives access to the quality of dielectric/semiconductor interfaces. Nevertheless, the SHG signal is also dependent on multilayer optical propagation phenomena. For this reason, we have developed a simulation program which accounts for the optical phenomena and the static electric fields at the interfaces. We have used SHG to monitor the passivation quality of Al2O3/Si structures prepared with different processes and showed a correlation between SHG and minority carrier lifetime measurements. Qox and Dit were extracted from capacitance-voltage measurements and helped calculating the Edc values. The optical simulation, fed with known Edc values reproduced the experimental SHG data in these structures. The SHG was also used for Silicon-on-Insulator (SOI) substrates characterization. In thick SOI structures, both simulations and experimental results show that the SHG response is mainly given by optical interferences (Edc has no impact). In ultrathin SOI, the interfaces are electrically coupled and Edc is needed as input in the simulation in order to reproduce the experimental SHG data. This implies that in ultrathin SOI, SHG can access the interface electric fields in a non-destructive way
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39

Sono, Tleyane J. "The study of surface SHG and polygonal microcavity design for nonlinear applications on LiNbO3." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/70939/.

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A z-cut congruent lithium niobate crystal (LiNbO3) has been used in this thesis, as a platform for the surface second harmonic generation (SHG) studies and for the designs of polygonal microcavities for nonlinear applications. Reflection second harmonic generation (RSHG) experiments were performed on LiNbO3 to reveal the interfacial layer symmetry as the crystal is rotated around the z axis. RSHG was also used, unsuccessfully as a non-destructive tool to map the domain-inverted area in the poled LiNbO3 crystals. But nevertheless, the polarity of the direction of the y-axis of the crystal was determined from RSHG data and the data shows that this direction also inverts, during domain inversion. RSHG was used unsuccessfully to monitor the relaxation of the internal field within the domain inverted area of the poled LiNbO3. A general operational principle of optical microcavities was discussed, in which a detailed theory governing the operational modes of a resonating hexagonal microcavity, made from bulk LiNbO3 crystal was reviewed for nonlinear device applications. A model for a total internal reflection (TIR) technique for the QPM method in a double-resonating hexagonal mi- crocavity was formulated. The TIR-QPM model was based on finding a suitable hexagonal dimension in which, both the fundamental and SHG signal resonate simultaneously while at the same time allowing QPM to occur via TIR. The TIR-QPM model and the FDTD simulation were used to demonstrate the potential capability of the double-resonating hexagonal microcavity for efficient SHG. The model to achieve a nonlinear microcavity by periodically poling ring/disk resonator Ti:LiNbO3 ridge waveguide was introduced.
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40

Rossi, Giuliano. "Desenvolvimento de cavidade laser em 532nm para uso oftalmológico." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18152/tde-17112009-085705/.

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O presente trabalho trata-se do desenvolvimento de uma cavidade Laser de estado sólido e geração de segundo harmônico, para fins oftalmológicos. A cavidade faz parte de um projeto maior que se refere a um fotocoagulador portátil, utilizado em diversos protocolos clínicos relacionados às doenças da retina e câmara anterior, como retinopatia diabética, retinopatia da prematuridade, glaucoma, edema macular e descolamento de retina. A cavidade proposta é composta por três espelhos dispostos em uma arquitetura em V. Um laser de diodo bombeia um cristal de Nd:YAG para a geração de laser em 1064nm que passa por um cristal de KTP para a geração de segundo harmônico em 532nm (laser verde). O sistema de acoplamento indexado à cavidade acopla até 90% da potência de saída em uma fibra óptica com núcleo de 100\'mü\'m. A cavidade projetada e implementada, produz um feixe com comprimento de onda de 532nm (laser verde), largura de banda de 0,5nm, potência máxima em torno de 2,5W na saída da fibra óptica e pulsos com duração máxima de 3s, que são requisitos para os tratamentos oftalmológicos associados a este tipo de equipamento. É importante destacar que a cavidade foi projetada e desenvolvida inteiramente com tecnologia nacional, sendo o primeiro trabalho desenvolvido no Brasil, que se tornou efetivamente um equipamento final para uso clínico. Além do projeto da cavidade laser, são descritos neste trabalho os sistemas mecânico e eletrônico, que possibilitaram seu funcionamento na integração do fotocoagulador. O fotocoagulador foi testado em pacientes voluntários da Escola Paulista de Medicina da UNIFESP, apresentando resultados comparáveis aos sistemas importados.
This work presents the research and the development of a solid state laser cavity with second harmonic generation for ophthalmological purpose. The laser cavity is part of a major project intended to produce a handle photocoagulator. This medical equipment is applied in several clinical protocols related to retinal and anterior chamber pathologies, such as diabetic retinopathy, retinopathy of prematurity, glaucoma, macular edema and retinal detachment. The present cavity is composed by three mirrors disposed in a V shape architecture. One laser diode pumps the Nd:YAG crystal to generate the 1064nm laser that is converted by second harmonic generation in 532nm through the KTP crystal (green laser). The coupling system attached in the cavity is able to collimate until 90% of the laser beam inside a optical fiber with 100 \'mü\'m core. The developed cavity produces a beam with wavelength of 532nm, spectral width of 0.5nm, maximum power around 2.5W in the end of the optical fiber and maximum pulse duration of 3s. Those parameters are requirements for ophthalmological treatments related to this kind of equipment. It is important to declare that the cavity was projected and developed in Brazil. This is the first work in this country that becomes effectively a device to clinical application. Besides the cavity design project, in this work also describes the mechanical and electronic sub systems that was responsible to the laser control and photocoagulator assembler. This product was tested in patients eyes from UNIFESP (Escola Paulista de Medicina), and showed similar results compared to the systems on the market.
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Schick, Ariane [Verfasser]. "Einfluss von Steatosis hepatis, metabolischem Syndrom und weiteren Parametern auf den biologischen Serum-Marker Sexualhormonbindendes Globulin (SHBG) / Ariane Schick." Ulm : Universität Ulm. Medizinische Fakultät, 2014. http://d-nb.info/105077163X/34.

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42

Roche, Didier. "Intérêts des dosages de l'IGF-1 et de la SHBG dans l'évaluation du statut nutritionnel de la personne âgée." Bordeaux 2, 1994. http://www.theses.fr/1994BOR2M221.

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43

Grira, Sarra Esling Claude. "Microstructure, texture et propriétés supraconductrices d'oxydes supraconducteurs haute température critique SHTc YBCO couches minces et NBCO and YBCO massifs /." Metz : Université de Metz, 2009. ftp://ftp.scd.univ-metz.fr/pub/Theses/2009/Grira.Sarra.SMZ0905.pdf.

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Thèse de doctorat : Sciences des matériaux : Metz : 2009. Thèse de doctorat : Sciences des matériaux : Northeastern University : 2009.
Thèse soutenue en co-tutelle. Titre provenant de l'écran-titre. Notes bibliographiques. Index.
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44

Gebhardt, Philipp [Verfasser], and Karl-Georg [Akademischer Betreuer] Kanz. "Kosten-Nutzenanalyse in der SHT (Schädel-Hirn-Trauma) - Diagnostik / Philipp Gebhardt. Betreuer: Karl-Georg Kanz." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/1036095428/34.

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45

Wheadon, C. J. D. (Christopher James Daniel), and n/a. "A systemic approach to understanding prehistoric shell-bearing deposits in New Zealand: a case study from Shag Point, North Otago." University of Otago. Department of Anthropology, 2002. http://adt.otago.ac.nz./public/adt-NZDU20070507.115526.

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This thesis describes a systemic approach to the study of shell remains, using material from the site of Shag Point (J43/11), in North Otago. This approach analyses the relationship between sampling, identification, quantification, and site formation processes. An historical and methodological framework is used to assess the analysis of shell-bearing deposits in New Zealand, and provide innovative solutions to bias. Historical research outlines the common research methods in New Zealand, which are relevant to Shag Point. Methodological research outlines the range of potential research methods used in the study of shell-bearing deposits. Reviewing the data from Shag Point, sampling, identification, quantification, and site formation processes are used to assess the quality of data from the site. Data from coastal sites are commonly used to generate regional level syntheses. These syntheses do not deal with all of the possible sources of bias in shell-bearing deposits. Cumulative sampling is used to assess representativeness. The data from Shag Point are indicative of a representative sample. The site is compared to three other coastal southern South Island assemblages: the nearby Shag River Mouth, Pleasant River, and Pounawea. The data from Shag River Mouth may be representative; the same cannot be said for the Pleasant River and Pounawea archaeological assemblages, thus hampering regional-level syntheses.
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46

Thorsteinson, Nels. "Computational ligand discovery for the human and zebrafish sex hormone binding globulin." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/943.

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Virtual screening is a fast, low cost method to identify potential small molecule therapeutics from large chemical databases for the vast amount of target proteins emerging from the life sciences and bioinformatics. In this work, we applied several conventional and newly developed virtual screening approaches to identify novel non-steroidal ligands for the human and zebrafish sex hormone binding globulin (SHBG). The ‘benchmark set of steroids’ is a set of steroids with known affinities for human SHBG that has been widely used for validation in the development of different virtual screening methods. We have updated this data set by including additional steroidal SHBG ligands and by modifying the predicted binding orientations of several benchmark steroids in the SHBG binding site based on the use of an improved docking protocol and information from recent crystallographic data. The new steroid binding orientations and the expanded version of the benchmark set was then used to create new in silico models which were applied in virtual screening to identify high-affinity non-steroidal human SHBG ligands from a large chemical database. Anthropogenic compounds with the capacity to interact with the steroid-binding site of SHBG pose health risks to humans and other vertebrates including fish. We constructed a homology model of SHBG from zebrafish and applied virtual screening to identify ligands for zebrafish SHBG from a set of 80 000 existing commercial substances, many of which can be exposed to the aquatic environment. Six hits from this in silico screen were tested experimentally for zebrafish SHBG binding and three of them, hexestrol, 4-tert-octylcatechol, dihydrobenzo(a)pyren-7(8H)-one demonstrated micromolar binding affinity for the zebrafish SHBG. These findings demonstrate the feasibility of using virtual screening to identify anthropogenic compounds that may disrupt or highjack functionally important protein:ligand interactions. Studies applying this new computational toxicology method could increase the awareness of hazards posed by existing commercial chemicals at relatively low cost.
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Williamson, Patricia Catherine. "Squaraine dyes." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323902.

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Kassab, Diana. "Localisation du site de liaison des stéroïdes de la protéine plasmatique de transport des stéroïdes ("Sex Hormone-Binding Globulin", "SHBG") de lapin et de mouton par photomarquage d'affinité avec la Δ6-testostérone et étude du rôle du stéroïde dans la dimérisation de fragments recombinants de SHBG humaine." Lyon 1, 1998. http://www.theses.fr/1998LYO1T145.

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Aït-Belkacem, Dora. "Microscopie polarimétrique du collagène de type I par génération de second harmonique dans des systèmes modèles et tissus." Thesis, Aix-Marseille 3, 2011. http://www.theses.fr/2011AIX30029.

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La génération de second harmonique (SHG) est un processus non-linéaire qui se produit dans des structures non-centrosymétriques, comme c'est le cas de certains matériaux cristallins ou biologiques. Il consiste à coupler deux champs à la même fréquence pour générer un photon à la fréquence double. La manipulation de la polarisation des champs incidents donne accès à des informations microscopiques et structurales de l'échantillon. De plus, l'utilisation d'une détection polarisée permet de mettre à jour des effets physiques dans les assemblages moléculaires biologiques.Dans ces travaux de thèse, nous nous intéressons principalement à l'étude des fibres de collagène I en SHG polarisée dans des échantillons modèles et des tissus. Nous étendons cette étude à la compréhension de l'interaction des fibres avec leur environnement cellulaire pour ensuite, aborder la problématique des tissus cancéreux. Enfin, nous proposons différents modèles microscopiques de la structure du collagène, évalués par une méthode basée sur la décomposition en série de Fourier du signal polarisé, pour apporter un diagnostic quantitatif sur des échantillons biologiques
Second harmonic generation (SHG) is a non-linear process which consists in coupling two photons at the same frequency to generate one photon at the twice frequency. It generally occurs in non-centrosymmetric samples such as crystals or molecular assemblies. The manipulation of the optical field polarization gives access to structural and microscopic informations. Moreover, using polarized detection allows to determine physical effects in molecular assemblies.In this Phd thesis, we are particulary interested in studying polarized SHG signals from collagen type I fibers in model samples and tissues. We extend our work to the investigation of the interaction of the fibers with their cellular environment. We also address the problematic of cancerous tissues.Finally, we propose several models for the microscopic structure of collagen, evaluated by a method based on the Fourier decomposition of the polarized SHG signal, to provide a quantitative diagnosis of biological samples
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50

Santos, Moisés Oliveira dos. "Ablação de pele queimada com laser de pulsos ultra-curtos para promoção da cicatrização. Avaliação por tomografia por coerência óptica, histologia, μATR-FTIR e microscopia não-linear." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-08032013-135443/.

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As queimaduras causam alterações na estrutura anatômica da pele associadas a trauma. As queimaduras podem ser classificadas em lesões de primeiro, segundo e terceiro grau. As queimaduras de terceiro grau têm sido grande foco de pesquisas em busca de tratamentos mais conservadores e de maior rapidez no reparo para um resultado funcional e estético satisfatório. O tratamento convencional consiste no uso de medicamentos tópicos e no enxerto de pele natural ou sintética. Alternativamente, a terapia laser utiliza o processo de ablação para remoção do tecido queimado necrosado, devido ao não contato mecânico, à rapidez na aplicação e alcance a áreas de difícil acesso. Deste modo, a proposta deste estudo é avaliar a viabilidade de utilizar lasers de femtossegundos de altíssima intensidade como coadjuvante no tratamento de pacientes queimados. Para o estudo, foram utilizados 25 ratos da raça Wistar, divididos em grupos de 5 animais: grupos pele sadia, pele queimada, dois tipos de tratamento (desbridamento cirúrgico ou ablação a laser de femtossegundos) e em quatro tempos de acompanhamento do processo cicatricial. Três regiões do dorso dos animais foram expostas a fonte de vapor causando queimadura de terceiro grau. No terceiro dia após a queimadura, uma das regiões foi ablacionada com laser de altíssima intensidade de pulsos ultracurtos ( λ = 785nm, 90 fs, 2 kHz e 10 μJ/pulso); outra recebeu o desbridamento cirúrgico; e a última foi considerada o controle de queimadura. As regiões foram analisados por tomografia por coerência óptica (OCT), histologia, reflectância total atenuada por espectroscopia no infravermelho usando transformada de Fourier (μATR-FTIR), microscopia de fluorescência por excitação de dois fótons (TPEFM) e a técnica de geração de segundo harmônico (SHG), nos dias 3, 5, 7 e 14 após os tratamentos. Os resultados mostraram que nas condições de irradiação utilizadas foi possível obter remoção de debris de queimadura de terceiro grau. As técnicas utilizadas para caracterização do tecido permitiram verificar que em todos os tratamentos houve a promoção da reparação tecidual. No décimo quarto dia, a curva de regeneração mostrou que o coeficiente de atenuação do tecido ablacionado a laser converge para os valores da pele sadia, porém as fibras de colágeno ainda não atingiram a mesma organização das fibras presentes na pele sadia.
Burns cause changes in the anatomical structure of the skin associated with trauma. The severity of the burn injury is divided into first, second and third-degree burns. The third-degree burns have been a major focus of research in search of more conservative treatments and faster results in repair for a functional and cosmetically acceptable. The conventional treatment is the use of topical natural or synthetic skin graft. An alternative therapy is the laser ablation process for burned tissue necrosis removal due to the no mechanical contact, fast application and access to difficult areas. The purpose of this study is to evaluate the feasibility of using high intensity femtosecond lasers as an adjunct treatment of burned patients. For this study, 65 Wistar rats were divided into groups of five animals: healthy skin, burned skin, two types of treatment (surgical debridement or femtosecond laser ablation) and four different times in the healing process monitoring. Three regions of the back of the animals were exposed to steam source causing third-degree burn. On the third day after the burn, one of the regions was ablated with high intensity ultrashort laser pulses (λ = 785 nm, 90 fs, 2 kHz and 10 μJ/ pulse), the other received surgical debridement, and the last was considered the burn control. The regions were analyzed by optical coherence tomography (OCT), histology, attenuated total reflectance infrared spectroscopy using Fourier transform (μ-ATR-FTIR), two-photon excitation fluorescence microscopy (TPEFM) and second harmonic generation technique (SHG) on days 3, 5, 7 and 14 pos-treatments. The results showed that with the laser irradiation conditions used it was possible to remove debris from third degree burn. The techniques used to characterize the tissue allowed to verify that all treatments promoted wound healing. On the fourteenth day, the regeneration curve showed that the attenuation coefficient of laser ablated tissue converges to the values of healthy skin, but collagen fibers have not yet reached the same organization of those in the healthy skin
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