No description available.

We used the first station of the Long Wavelength Array (LWA) to observe giant pulses (GPs) from pulsars and search for other radio transients. Using the LWA with a bandwidth of 16 MHz at 39 MHz, we made a 24-hour observation of pulsar radio pulses from PSR B0950+08. The average pulse ux density and pulse width (dominated by "normal" pulses) are consistent with previous studies by others. Using techniques we developed for searching for radio transients, in this observation we detected 119 giant pulses (with signal-to-noise ratios 10 times larger than for the mean pulse). The giant pulses have a narrower temporal width (17.8 ms, on average) than the mean pulse (30.5 ms). Giant pulses occur at a rate of about 5.0 per hour, or 0.035% of the total number of pulse periods. The strength and rate of giant pulses is less than observed by others at ~100 MHz. The probability distribution of the cumulative pulse strength is a power law, but deviates from the Gaussian distribution of normal pulses. These results suggest PSR B0950+08 produces less frequent and weaker giant pulses at 39 MHz than at 100 MHz. We detected no other transients in this observation within a dispersion measure (DM) range from 1 to 90 pc cm³. Furthermore, we conducted observations of giant pulses from PSR B0950+08 in a separate set of observations of 12 hours made simultaneously at 42 and 74 MHz. In these observations we detected a total of 275 at 42 MHz and a total of 465 giant pulses at 74 MHz. Giant pulses with double-peak temporal structure have a shorter peak-to-peak separation compared to the average pulse. Once again, PSR B0950+08 appears to produce less frequent and weaker giant pulses than reported at 100 MHz. Giant pulses are identified with signal-to-noise ratios 10 times larger than for the mean pulse, and the probability distribution of the cumulative pulse strength is a power law, but deviate from the Gaussian distribution of normal pulses, for both frequencies. There were only 128 giant pulses detected simultaneously at 42 and 74 MHz, which implies that more than half of them are narrow-band radio pulses. Using these observations we analyzed the effect of scattering due to the interstellar medium on pulses with signal-to-noise ratio > 7 and the average pulse using a CLEAN-based algorithm, assuming a thin-screen scattering model. The scatter-broadening time constant τ ∝ ν^α, where ν is the observing frequency. The resulting α as calculated from pulses with signal-tonoise ratio > 7 and for the average pulses is found to be α = −1.45±0.14 and −0.14±0.03, respectively. These results indicate differences along the line of sight from a Kolmogorov spectrum for electron density uctuations. We calculated the altitude of the emission region for the pulsar using the dipolar magnetic field model. We found a similar magnitude for the emission region altitudes of normal and giant pulses. We detected no other transient pulses in a wide DM range from 1 to 4990 pc cm⁻³. We also conducted another a 12-hour observational study of PSR B0031−07 at 38 and 74 MHz, simultaneously. Giant pulses were identified with ux densities of a factor of ≥ 90 and ≥ 80 times that of an average pulse, at 38 and 74 MHz. The cumulative pulse strength distribution follows a power law, and has a much more gradual slope than a Gaussian distribution for the normal pulses. We found 158 of the observed pulses at 38 MHz qualified as giant pulses. At 74 MHz a total of 221 of the observed pulses were giant pulses. Only 12 giant pulses were detected within the same pulse period at both 38 and 74 MHz, meaning that the majority of them are narrow-band radio pulses. No other radio transients were detected within a DM range 1 to 4990 pc cm⁻³. We used the same data processing pipeline for observations of pulsar GPs to search within the pulsar observations for fast radio bursts (FRBs). We did not detect any nonpulsar signals with signal-to-noise ratio larger than 10. When the radio transient signals propagate through the interstellar medium, they are affected by propagation effects such as dispersion and scattering. Scattering may limit the detectability of radio transients. By examination of archived pulsar profiles, we investigated the impact of scattering on observed pulses. We utilized a CLEAN-based strategy to decide the scatter-broadening time, τ , under both the thin-screen and uniform-medium scattering models and to determine the scatter-broadening time frequency scaling index, α, where τ ∝ ν^α. In most cases the scattering tail was not large compared to the pulse width at half maximum. Still, we deconvolved 1342 pulse profiles from 347 pulsars assuming a Kolmogorov spectrum of the interstellar medium turbulence. For a subset of 21 pulsars the scattering-boarding tails were suficiently long to be estimated at the lowest frequencies. Since the scatter-broadening times were only determined distinctly for the subset of pulsars at the lowest observed frequency, we were restricted to utilizing upper limits on scatter-broadening times at higher frequencies for the assessment of the scatter-broadening-time frequency dependence. We include three new direct scatter-broadening time measurements at low frequencies and they are consistent with previous studies which were scaled from higher frequencies. Our findings are consistent with a relationship between the DM and scatter-broadening time which can range over more than two orders of magnitude in DM. One of the potential reasons that we did not detect FRBs is that transients may be highly scatter-broadened at low frequencies for high DM values. / Ph. D.

A citometria de fluxo é um método preciso, rápido e eficaz na avaliação de múltiplos parâmetros celulares, tanto estruturais como funcionais, propiciando a separação e o estudo de diferentes populações e sub-populações de células. No presente estudo, foram empregados métodos citométricos para caracterização dos diferentes tipos celulares sangüíneos de Centropomus parallelus, assim como para verificação da viabilidade celular, avaliação da atividade fagocítica e ativação do burst respiratório. Foram identificadas três sub-populações representativas de leucócitos: linfócitos, monócitos e trombócitos. Estas células foram estimuladas, in vitro, com Staphylococcus aureus, marcado com iodeto de propídeo (SAPI), lipopolissacarídeo de Escherichia coli (LPS) e zymosan, partículas de Saccharomyces cerevisiae. As respostas frente aos estímulos foram distintas de acordo com o tipo celular e o estímulo apresentado. Os monócitos apresentaram maiores percentuais de fagocitose frente ao estímulo provocado pela SAPI e pelo Zymosan; já a população que continha trombócitos entre outros tipos celulares (por exemplo: linfócitos), apresentou \"fagocitose\" significativa apenas para SAPI. O burst oxidativo detectado pela fluorescência emitida pelo diacetato 2´7´diclorofluoresceína (DCFH) foi significativo apenas quando estimulado com PMA (miristato-acetato de forbol), não apresentando resposta estatisticamente significante para os estímulos SAPI e LPS. Após a exposição ao naftaleno nas concentrações 10-3, 10-6, 10-9 M durante quatro horas, in vitro, houve um aumento na fagocitose realizado pelos monócitos e trombócitos, porém uma diminuição no burst oxidativo apresentado nas concentrações 10-6 e 10-9 M de naftaleno. Este resultado reflete, in vitro, uma resposta ao contaminante com significado imunológico desfavorável para o peixe, já que as células estão aumentando a atividade fagocítica sem conseguirem, teoricamente, destruir o agente invasor. A partir desses resultados preliminares, podemos avaliar melhor, algumas características da resposta imune inata desta espécie de peixe, presente na costa litorânea brasileira. Estes parâmetros imunofisiológicos podem servir como base para futuros estudos ecotoxicológicos tanto em laboratório mas também a campo. Estudos que utilizam a imunidade inata como indicador biológico de alterações ambientais causadas por poluentes diversos, podem evidenciar o grau de impacto toxicológico sobre esta espécie e agregar valor a sua importância econômica e ecológica. / Flow cytometry is a precise, fast, and effective method for the evaluation of several cellular parameters, both structural and functional, allowing the sorting and analysis of particular populations and sub-populations of cells. In this study, we employed cytometric methods on the caractherization of different blood cell types from Centropomus parallelus, and also verified cell viability, phagocytic activity and oxidative burst in these cells. Three sub-populations were identified: lymphocytes, monocytes, and trombocytes. These cells were stimulated in vitro with propidium iodide-conjugated Staphylococcus aureus (SAPI), Escherichia coli lipopolysaccharide (LPS), or zymosan (Saccharomyces cerevisae particles). Responses to each individual stimulus differed according to cell type. Monocytes displayed the higher percentages of phagocytosis in presence of SAPI or zymosan; on the other hand, the population that included trombocytes, among other cell types (such as lymphocytes) only performed phagocytosis in a relevant level in the presence of SAPI. The oxidative burst, detected by fluorescence emitted by 2´7´dichlorofluorescein diacetate (DCFH) was significant only after stimulation with PMA (phorbol myristate-acetate), but not when the stimulus was SAPI or LPS. Based on these preliminary results, the innate immune response in these animals (ubiquitous coastal waters of the Brazilian shore) can be further evaluated. Immunophysiological parameters in these species can build a solid ground for future ecotoxicological studies. Approaching innate immunity as a biological indicator of environmental changes induced by pollutants may support the degree of toxicological impact over these animals, and aggregate value to its current ecological and economical importance.

A citometria de fluxo é um método preciso, rápido e eficaz na avaliação de múltiplos parâmetros celulares, tanto estruturais como funcionais, propiciando a separação e o estudo de diferentes populações e sub-populações de células. No presente estudo, foram empregados métodos citométricos para caracterização dos diferentes tipos celulares sangüíneos de Centropomus parallelus, assim como para verificação da viabilidade celular, avaliação da atividade fagocítica e ativação do burst respiratório. Foram identificadas três sub-populações representativas de leucócitos: linfócitos, monócitos e trombócitos. Estas células foram estimuladas, in vitro, com Staphylococcus aureus, marcado com iodeto de propídeo (SAPI), lipopolissacarídeo de Escherichia coli (LPS) e zymosan, partículas de Saccharomyces cerevisiae. As respostas frente aos estímulos foram distintas de acordo com o tipo celular e o estímulo apresentado. Os monócitos apresentaram maiores percentuais de fagocitose frente ao estímulo provocado pela SAPI e pelo Zymosan; já a população que continha trombócitos entre outros tipos celulares (por exemplo: linfócitos), apresentou \"fagocitose\" significativa apenas para SAPI. O burst oxidativo detectado pela fluorescência emitida pelo diacetato 2´7´diclorofluoresceína (DCFH) foi significativo apenas quando estimulado com PMA (miristato-acetato de forbol), não apresentando resposta estatisticamente significante para os estímulos SAPI e LPS. Após a exposição ao naftaleno nas concentrações 10-3, 10-6, 10-9 M durante quatro horas, in vitro, houve um aumento na fagocitose realizado pelos monócitos e trombócitos, porém uma diminuição no burst oxidativo apresentado nas concentrações 10-6 e 10-9 M de naftaleno. Este resultado reflete, in vitro, uma resposta ao contaminante com significado imunológico desfavorável para o peixe, já que as células estão aumentando a atividade fagocítica sem conseguirem, teoricamente, destruir o agente invasor. A partir desses resultados preliminares, podemos avaliar melhor, algumas características da resposta imune inata desta espécie de peixe, presente na costa litorânea brasileira. Estes parâmetros imunofisiológicos podem servir como base para futuros estudos ecotoxicológicos tanto em laboratório mas também a campo. Estudos que utilizam a imunidade inata como indicador biológico de alterações ambientais causadas por poluentes diversos, podem evidenciar o grau de impacto toxicológico sobre esta espécie e agregar valor a sua importância econômica e ecológica. / Flow cytometry is a precise, fast, and effective method for the evaluation of several cellular parameters, both structural and functional, allowing the sorting and analysis of particular populations and sub-populations of cells. In this study, we employed cytometric methods on the caractherization of different blood cell types from Centropomus parallelus, and also verified cell viability, phagocytic activity and oxidative burst in these cells. Three sub-populations were identified: lymphocytes, monocytes, and trombocytes. These cells were stimulated in vitro with propidium iodide-conjugated Staphylococcus aureus (SAPI), Escherichia coli lipopolysaccharide (LPS), or zymosan (Saccharomyces cerevisae particles). Responses to each individual stimulus differed according to cell type. Monocytes displayed the higher percentages of phagocytosis in presence of SAPI or zymosan; on the other hand, the population that included trombocytes, among other cell types (such as lymphocytes) only performed phagocytosis in a relevant level in the presence of SAPI. The oxidative burst, detected by fluorescence emitted by 2´7´dichlorofluorescein diacetate (DCFH) was significant only after stimulation with PMA (phorbol myristate-acetate), but not when the stimulus was SAPI or LPS. Based on these preliminary results, the innate immune response in these animals (ubiquitous coastal waters of the Brazilian shore) can be further evaluated. Immunophysiological parameters in these species can build a solid ground for future ecotoxicological studies. Approaching innate immunity as a biological indicator of environmental changes induced by pollutants may support the degree of toxicological impact over these animals, and aggregate value to its current ecological and economical importance.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-12T18:16:09Z No. of bitstreams: 1 TeseNSS.pdf: 3636561 bytes, checksum: af079696a221c11c574fe705355778f8 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T18:23:49Z (GMT) No. of bitstreams: 1 TeseNSS.pdf: 3636561 bytes, checksum: af079696a221c11c574fe705355778f8 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T18:23:56Z (GMT) No. of bitstreams: 1 TeseNSS.pdf: 3636561 bytes, checksum: af079696a221c11c574fe705355778f8 (MD5) / Made available in DSpace on 2016-09-13T18:24:03Z (GMT). No. of bitstreams: 1 TeseNSS.pdf: 3636561 bytes, checksum: af079696a221c11c574fe705355778f8 (MD5) Previous issue date: 2015-08-24 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The increase of fish production in intensive systems involves the use of antimicrobians in the treatment of diseases caused by bacteria. Therefore, the aim of this study was to evaluate acute toxicity (CL50; 48h) of the antimicrobial azithromycin (AZT) for fingerlings of tilapia (Oreochromis niloticus), the effects on young tilapia, after chronic exposure (14 days) via hematological analysis, morphology gills, liver and kidneys and antioxidant system responses in the liver, and to determine the efficacy of control of Aeromonas hydrophila via hematological analysis and innate immune response, in addition to the morphological effects gills, kidneys and liver and antioxidant system responses in the liver. The acute toxicity (LC50; 48h) of the AZT to tilapia was > 100 mg L-1 being th AZT classified as practically non-toxic. After chronic exposure, there was an increase in hematocrit (Hct), hemoglobin concentration (Hb) and in the mean corpuscular volume of erythrocytes (MCV) and no change in the other variables of the red series was observed. The leukocytes increased after exposure to 100 mg L-1 AZT. Histological changes in gills suggest defense response against irritant agent and indicate normal structure and function of the organ; in the kidney no changes was observed and in the liver changes were classified as moderate to severe. In the efficacy trial, the offering of medicated food with AZT (100 and 125 mg kg-1) to animals infected with A. hydrophila was efficient and all of the treated animals survived; of the untreated animals 22% came to death. The Hct decreased and the hematimetric indices mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration increased, the percentage of lymphocytes decreased and the percentage of neutrophil increased in untreated infected animals, but were unchanged in animals treated with AZT. No change occurred in innate immunity assessed by the activity of lysozyme, complement system and leukocytes respiratory burst activity. Gills showed no changes that could interfere in the organ function, in the liver changes were classified from mild to moderate and didn´t occurred alterations in the kidneys. Animals treated with AZT showed no adverse effects related to defense cells and the innate immune activity. The drug also caused no changes in antioxidant defense enzymes in the animals' liver after chronic exposure and did not generate oxidative stress. After challenge with A. hydrophila occurred an increased in the activity of catalase, glutathione peroxidase, glutathione transferase and glutathione level in the liver of animals treated with AZT and the glutathione level decreased in the infected group and untreated. These responses suggest that infection caused by A. hydrophila can induce an increased production of ROS and, consequently, stimulated responses of the antioxidant defenses. These responses were effective to prevent the occurrence of oxidative stress. / O aumento da produção de peixes em sistema intensivo implica no uso de antimicrobianos em tratamento de doenças causadas por bactérias. Dessa forma, o objetivo deste estudo foi avaliar toxicidade aguda (CL50;48h) do antimicrobiano azitromicina (AZT) para alevinos de tilápia (Oreochromis niloticus). Os seus efeitos em jovens de tilápia, após exposição crônica (14 dias), pela análise hematológica, morfologia de brânquias, fígado e rins e respostas do sistema antioxidante no fígado, assim como a determinação da eficácia sobre Aeromonas hydrophila, pela análise hematológica e resposta imune inata, além dos efeitos morfológicos em brânquias, fígado e rins e respostas do sistema antioxidante no fígado. A toxicidade aguda (CL50;48h) da AZT para tilápia foi > 100 mg L-1 sendo classificada como praticamente não tóxico. Após exposição crônica, ocorreu aumento do hematócrito (Hct), concentração de hemoglobina (Hb), e no volume corpuscular médio dos eritrócitos (VCM) sem alterações nas demais variáveis da série vermelha. Os leucócitos aumentaram após exposição a 100 mg L-1 de AZT. As alterações histológicas nas brânquias sugerem resposta de defesa contra agente irritante e indicou estrutura e função normal do órgão; nos rins não ocorreu alterações e no fígado foram classificadas como moderadas a severas. No ensaio de eficácia, com ração medicada com AZT (100 e 125 mg kg-1) aos animais infectados com A. hydrophila se mostrou eficiente, e todos os animais tratados sobreviveram. A mortalidade no grupo não tratado foi de 22 %. O hematócrito diminuiu e os índices hematimétricos, hemoglobina corpuscular média e a concentração de hemoglobina corpuscular média aumentaram. A porcentagem de linfócitos diminuiu e a de neutrófilos aumentou nos animais infectados não-tratados, mas sem alteração nos animais tratados. Não ocorreu alteração na imunidade inata, avaliada pela atividade da lisozima, sistema complemento e “burst” respiratório dos leucócitos. As brânquias não apresentaram alterações que interferissem na função do órgão. No fígado as alterações foram classificadas de leves a moderadas, sem alteração nos rins. Animais tratados com AZT não apresentaram efeitos adversos relacionados às células de defesa e atividade imune inata. O fármaco também não causou alterações nas enzimas de defesa antioxidantes no fígado dos animais após exposição crônica, sem estresse oxidativo. Após desafio com A. hydrophila ocorreu aumento da atividade da catalase, glutationa peroxidase, glutationa transferase e nível de glutationa no fígado dos animais tratados com AZT e o nível de glutationa diminuiu no grupo infectado e não tratado. Estas respostas sugerem que a infecção causada pela A. hydrophila pode induzir o aumento da produção de espécies reativas de oxigênio e, consequentemente, estimulou as respostas das defesas antioxidantes. Essas respostas foram eficientes para evitar a ocorrência de estresse oxidativo. / FAPESP: 2011/21552-6

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No. of bitstreams: 1 wolf_vg_me_arafcf.pdf: 3123091 bytes, checksum: 0e5f498e0767893a065858a9ae558c1c (MD5) Previous issue date: 2017-06-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Helicobacter pylori é um dos principais causadores de gastrite crônica e úlcera péptica, e embora o mecanismo envolvido na inflamação gástrica por esta bactéria não esteja completamente elucidado, sabe-se do importante papel das espécies reativas de oxigênio (EROs) produzidas por polimorfonucleares neutrófilos, que são atraídos e ativados pelo agente da infecção, sem que, entretanto, consigam debelar a mesma, mas que contribuem fortemente para a lesão tecidual e o processo inflamatório crônico. Diante disso, tem aumentado a busca de novas estratégias de tratamento que possam levar à redução do estresse oxidativo gerado no sítio da infecção, com consequente redução do processo inflamatório. Neste sentido, ácido gálico, juntamente com seus ésteres (galato de metila, propila, hexila e octila), foram utilizados neste estudo, com o objetivo de avaliar suas ações como inibidores da liberação de EROs por neutrófilos ativados, bem como seus efeitos antimicrobianos sobre H. pylori. Para a avaliação da atividade antioxidante dessas substâncias foram realizados ensaios livres de células (efeito supressor sobre o radical DPPH e sobre radicais peroxila), e o efeito anti-EROs foi avaliado utilizando neutrófilos isolados de sangue humano estimulados por H. pylori, Zymosan ou PMA, através de ensaio quimiluminescente dependente de luminol ou lucigenina, ensaio com WST-1, ensaio de inibição da produção de HOCl, e o teste do NBT. Ensaio antimicrobiano foi realizado através da técnica de microdiluição em caldo. A presença da cadeia lateral carbônica levou a um significativo aumento na capacidade dos ésteres em inibir a produção de EROs por neutrófilos ativados, quando comparados ao ácido precursor, com destaque para os galatos de hexila e octila, que inibiram em quase 100% a produção de radical ânion superóxido, bem como de todas as EROs do burst oxidativo de forma geral. Galatos de octila e hexila também mostraram-se ser as moléculas com maior atividade antimicrobiana sobre H. pylori, com um valor de CIM de 125 e 250g/mL, respectivamente, ao passo que as demais substâncias apresentaram valor de CIM acima de 1000 g/mL. Os resultados obtidos mostram o grande potencial dos ésteres do ácido gálico quanto à suas atividades anti-H. pylori e anti-EROs, e além disso demonstram a importância da presença de uma cadeia carbônica lateral, conferindo maior hidrofobicidade à molécula, para obter-se a máxima atividade antimicrobiana in vitro e a máxima atividade antioxidante em modelo ex vivo. Assim, os ésteres do ácido gálico apresentam-se como moléculas promissoras no tratamento da infecção por Helicobacter pylori, apresentando ação antimicrobiana sobre o mesmo, bem como na redução do estresse oxidativo gerado no sítio da infecção. / Helicobacter pylori is one of major cause of chronic gastritis and peptic ulcer disease, and although the mechanism involved in gastric inflammation by this bacterium is not fully understood, it is know the important role of reactive oxygen species (ROS) produced by polymorphonuclear neutrophils (PMNs), which are attracted and activated by infection agent, without, however, to be able to overcome the same, but which contribute strongly to the tissue damage and chronic inflammation. Therefore, it has increased the search for new strategies of treatment that can lead to the reduction of the oxidative stress generated at the infection site, with consequent reduction of the inflammatory process. In this sense, gallic acid, together with its esters (methyl, propyl, hexyl and octyl gallate), were used in this study, with the aim of evaluating their actions as inhibitors of ROS release by activated neutrophils, as well as their antimicrobial effects on H. pylori. Cell-free assays (suppressor effect on the DPPH radical and peroxyl radicals) were performed to evaluate the antioxidant activity of these substances, and the anti-EROs effect was evaluated using neutrophils isolated from human blood, stimulated by H. pylori, Zymosan or PMA, through luminol-dependent or lucigenin-dependent chemiluminescent assay, WST-1 assay, inhibition of HOCl production assay, and the NBT assay. Antimicrobial assay was performed by broth microdilution technique. The presence of the carbonic side chain led to a significant increase in the ability of the esters to inhibit the ROS production by activated neutrophils when compared to the precursor acid, especially hexyl and octyl gallates, which inhibited practically 100% of the superoxide anion radical production, as well as all ROS of the oxidative burst in general. Octyl and hexyl gallates were also shown to be the molecules with the highest antimicrobial activity on H. pylori, with a MIC value of 125 and 250 μg/mL, respectively, while the other substances had a MIC value higher than 1000 g/ml. The results show the great potential of the esters of gallic acid for their anti-H. pylori and anti-EROs activities, and furthermore demonstrate the importance of the presence of a lateral carbonic chain, giving greater hydrophobicity to the molecule, to obtain the maximum antimicrobial activity in vitro and the maximum antioxidant activity in an ex vivo model. Thus, esters of gallic acid are promising molecules in the treatment of Helicobacter pylori infection, presenting antimicrobial action on the same, as well as reducing the oxidative stress generated at the site of infection. / CNPq: 130667/2015-3 / FAPESP: 2015/21693-0

Burst abdomen (BA) is a severe complication after abdominal surgery, which often requires urgent repair. However, evidence on surgical techniques to prevent burst abdomen recurrence (BAR) is scarce. We conducted a retrospective analysis of patients with BA comparing them to patients with superficial surgical site infections from the years 2015 to 2018. The data was retrieved from the institutional wound register. We analyzed risk factors for BA occurrence as well as its recurrence after BA repair and surgical closure techniques that would best prevent BAR.:1 Abkürzungsverzeichnis 2 Einführung 2.1 Aufbau der Bauchwand und operative Zugangswege in der Abdominalchirurgie 2.1.1 Anatomie 2.1.2 Zugangswege 2.2 Wundinfektionen 2.3 Definition „Platzbauch“ 2.4 Risikofaktoren und Ursachen von Fasziendehiszenzen 2.4.1 Biochemische Einflüsse auf die Wundheilung 2.4.2 Mechanische und technische Faktoren 2.4.3 Allgemeine individuelle Faktoren 2.5 Management des Platzbauchs 2.6 Spätkomplikationen des Platzbauches 2.6.1 Narbenhernien 2.6.2 Intestinale Fisteln 2.6.3 Netzinfektion 2.6.4 Re-Dehiszenzen 3 Zielsetzung der vorliegenden Arbeit 4 Publikation 5 Zusammenfassung der Arbeit 5.1 Einleitung 5.2 Wundregister nosokomialer Wundinfektionen der Klinik für Viszeral-, Transplantations-, Thorax- und Gefäßchirurgie am Universitätsklinikum Leipzig 5.3 Risikofaktoren für Platzbäuche 5.4 Platzbauchentstehung 5.5 Chirurgische Verschlusstechnik 5.6 Re-Dehiszenzen 5.7 Limitationen der Analyse 6 Literaturverzeichnis 7 Anlagen 7.1 Darstellung des eigenen Beitrags 7.2 Selbstständigkeitserklärung 7.3 Lebenslauf 7.4 Publikationen 8 Danksagung

<p dir="ltr">From transonic to hypersonic regimes, the characterization of high-speed flow dynamics is critical for the development, testing, and improvement of launch and reentry vehicles, boost-glide vehicles, and thermal protection systems. The design of this technology often relies on computational/empirical models for predictions which make quantitative thermodynamic measurements crucial for numerical validation. Laser diagnostic techniques facilitate non-intrusive, <i>in situ</i> measurements of fluid dynamic properties as well as visualization of flows, shocks, and boundary layer interactions. However, many diagnostics rely on seeding the flow with foreign materials to make measurements, such as the application of particle image velocimetry (PIV), Doppler global velocimetry (DGV), and planar laser-induced fluorescence (PLIF). Molecular filtered Rayleigh scattering (FRS) diagnostics are attractive for flow characterization due to the fact that pressure, temperature, density and velocity measurements can be made directly from air or N₂ molecules without the need for seeding materials. The development of the burst-mode laser (BML) has enabled high-energy pulses generated at the rates necessary to resolve phenomena such as instabilities in boundary-layers and shock-wave evolution using Rayleigh scattering methods. The goal of this dissertation is to advance molecular burst-mode FRS for quantitative, high resolution, multi-parameter measurements. For fixed-wavelength FRS measurements, the spectral characteristics of a BML system were investigated and improved by integrating an etalon for spectral-gating. For multi-parameter measurements, two strategies for wavelength-agility, the ability to quickly switch between two or more laser wavelengths, of the BML were explored: frequency-scanning and frequency-shifting. The frequency-scanning FRS (FS-FRS) technique measurement rate was increased to 1 kHz and demonstrated for 1-ms pressure, temperature, and radial velocity measurements in an underexpanded jet flow. Building upon this, an acousto-optic modulator-based method was implemented to generate frequency-shifted pulses. The rapid frequency-shifting increased the effective FRS multi-parameter measurement rate to 25 kHz and planar pressure, temperature, and radial velocity measurements were captured in an overexpanded jet flow. Finally, design tools for the laser configuration of wavelength-agile FRS were developed for the optimization of relative absolute measurement errors.</p>

O presente trabalho tem o objetivo principal de compreender os possíveis efeitos da radiação energética de um evento de Gamma-Ray Burst (GRB) sobre o meio interestelar no entorno de seu local de geração e em planetas possivelmente iluminados. Gamma-Ray Bursts foram detectados pela primeira vez nos anos 60 e rapidamente atraíram a atenção da comunidade astrofísica, uma vez que as energias emitidas apenas em poderiam alcançar 1054erg, o equivalente a massa de repouso do Sol. Não se conhecia nenhum mecanismo tão eficiente para extrair energia gravitacional para produzir tal evento. Mais tarde, a possibilidade da emissão ser colimada abaixou a energia em para 5x1050erg, mas o mecanismo central de geração ainda não foi completamente desvendado, havendo muito espaço para alternativas exóticas. Estudamos os efeitos de um GRB sobre o meio interestelar, em uma tentativa de distinguir os remanescentes do GRB do gerado por múltiplas supernovas. Usamos argumentos energéticos e sobre a possibilidade de alterações químicas e isotópicas devido a reações fotonucleares. Também trabalhamos com as implicações biológicas da iluminação de planetas por um GRB, concluindo que os efeitos de tais eventos podem afetar seriamente a biosfera de um planeta mesmo a distâncias de ~10kpc. / The present work has the main goal of understanding the possible effects of the hard gamma radiation produced during a Gamma-Ray Burst (GRB) event both on the interstellar medium surrounding the source of the burst and on planets possibly illuminated. Gamma-Ray Bursts were first detected on the 60s and quickly have attracted the attention of the astrophysical community, since the energies emitted just in could reach 1054erg, the rest mass of the Sun. No mechanism was known to be so efficient in extracting gravitational energy to produce such emission. Later on, the possibility of the emission being collimated has lowered the energy of the to 5x1051erg, but the central engine has not yet been completely understood, and there is still ample room for exotic alternatives. We have studied the effects of GRB on the ISM, in an attempt to distinguish the candidates of GRB remnants from those generated by multiple supernovae. We have used both energetic arguments and the possibility of chemical alterations due to photonuclear reactions. We have also worked on the biological implications of the illumination of planets by a GRB, concluding that the effects of such event could seriously harm the biosphere of a planet even at distances of ~10kpc.

As infecções constituem a principal causa de morbidade e mortalidade em pacientes com lúpus eritematoso sistêmico (LES), representando 20-55% das mortes e sendo 80% delas causadas por bactérias. O LES é uma doença autoimune inflamatória crônica e a suscetibilidade às infecções está associada às próprias anormalidades imunológicas da doença, bem como a sua terapia, particularmente imunossupressora e citotóxica. Além disso, os polimorfismos genéticos dos Fc?R, Fc?RIIa e Fc?RIIIb, nos neutrófilos, têm sido associados com as disfunções imunes do LES.Os Fc?R são importantes mediadores das funções efetoras do neutrófilo e atuam em sinergismo com os CR. O polimorfismo dos genes FCGR2A e FCGR3B determina a expressão de variantes alélicas com diferenças funcionais, as quais podem influenciar as respostas biológicas e a suscetibilidade e o prognóstico das doenças infecciosas.O objetivo deste estudo foi avaliar a influência dos polimorfismos dos receptores Fc?RIIa (H/R131), Fc?RIIIb (HNA-1a, HNA-1b e HNA-1c) e CR3 (HNA-4a) no burst oxidativo de neutrófilos de pacientes com LES.Neutrófilos de pacientes com LES (n=36) e indivíduos saudáveis (n=36) foram purificados do sangue periférico (0.5x106/500µL) e estimulados com 30µg de IC, IC/soro humano normal (SHN), IC/SHN inativado ou PMA 10-7M. O burst oxidativo foi medido por quimioluminescência (QL) na presenca de luminol 10-4M ou lucigenina 10-4M. As frequências dos genótipos de Fc?RIIa, Fc?RIIIb e HNA-4a em pacientes com LES (n=157) e indivíduos saudáveis (n=147) foram determinadas por PCR com primers oligoespecíficos e gel de agarose 2%.Quanto aos polimorfismos genéticos, foi observado que o alelo positivo de HNA-4a contribui para a proteção e o alelo negativo para a suscetibilidade ao LES. Entre os pacientes com LES, as infecções foram mais frequentes quando os alelos R131 de FCGR2A, HNA-1b de FCGR3B e HNA-4a positivo do CR3 estavam presentes. Para o burst oxidativo com luminol, no grupo controle, as homozigoses H131, HNA-1b e HNA-4a negativo foram associadas à redução do burst oxidativo dos neutrófilos comparado às homozigoses para os respectivos alelos correspondentes. No LES, o burst oxidativo foi maior na homozigose R131 do grupo LES inativo comparado ao homozigoto H131 controle; menor na homozigose HNA-1b do grupo LES ativo comparado ao homozigoto HNA-1a do controle e, também, na heterozigose HNA-4a positivo/negativo o burst foi menor no grupo LES ativo comparado ao LES inativo. A ausência de diferenças entre os grupos com LES e controle, nos ensaios de burst oxidativo com lucigenina e com PMA, sugerem que a NADPH oxidase, responsável pela geração do burst oxidativo, não está comprometida nos neutrófilos dos pacientes com LES. Esses resultados têm implicações para a fisiopatologia do LES e, sobretudo, reforçam a hipótese de que os polimorfismos dos FCGR2A, FCGR3B e HNA-4a modulam o burst oxidativo de neutrófilos nos indivíduos saudáveis e no LES. Assim, o presente estudo contribui para o entendimento das anormalidades nas funções dos neutrófilos no LES. / Infections represent 20-55% of all deaths in patients with systemic lupus erythematosus (SLE). About 80% of them are caused by bacteria. SLE is an autoimmune disease in whichdisease-related and genetic factors and immunosuppressive and cytotoxic therapies all contributeto an increased susceptibility to infections.Recent data have provided evidence that genetic polymorphism of Fc?R is associated withimmune abnormalities and risk to development of SLE.Fc?R can mediate neutrophil effector functions and play a synergistic action with CR. Fc?RIIaand Fc?RIIIb display functionally relevant genetic polymorphisms, which allelic variants caninfluence the biological responses and the susceptibility to and course of infectious diseases.The aim of this study was to investigate the influence of the Fc?RIIa (H/R131), Fc?RIIIb (HNA- 1a, HNA-1b and HNA-1c) and CR3 (HNA-4a) polymorphisms on neutrophil oxidative burst of SLE patients. Neutrophils of SLE patients (n=36) and control individuals (n=36) were purified from peripheral blood (0.5x106/500µL) in Hanks 0.1% gelatin pH7.2 and were stimulated with 30µg of immune complexes (IC), IC/normal human serum (NHS), IC/heat-inactivated NHS (iNHS) or PMA 10-7M. The oxidative burst was measured by chemiluminescence (CL) in the presence of luminol 10-4M or lucigenin 10- 4 M. The reaction was monitored in a luminometer at 37ºC for 20min and the results were analyzed as the area under the curve of the CL profile. Genotype frequencies of Fc?RIIa, Fc?RIIIb and HNA-4a alleles for SLE patients (n=157) and for healthy subjects (n=147) were determined using PCR with sequence-specific primers and agarose gel 2%. It was observed that the HNA-4a positive allele contributes to the protection and the negative allele contributes to susceptibility to SLE. Among patients with SLE, infections were more frequent when the alleles R131 of FCGR2A, HNA-1b of FCGR3B and HNA-4a positive of CR3 were present. For the oxidative burst with luminol in the control group, the homozygous H131, HNA-1b and HNA-4a negative were associated with reduced oxidative burst of neutrophils compared to homozygous to their corresponding alleles. In SLE, the oxidative burst was higher in homozygous R131 inactive SLE group compared to the homozygous H131 control; it was also lower in homozygous HNA-1b active SLE group than homozygous HNA-1a control and either in the heterozygous HNA-4a positive/negative active SLE compared to inactive SLE group. The absence of differences between the SLE and control groups in the oxidative burst assays, using lucigenin and PMA, suggests that NADPH oxidase, responsible for generating the oxidative burst, is not impaired in neutrophils from patients with SLE. These results have implications for the pathophysiology of SLE and, above all, support the hypothesis that polymorphisms of FCGR2A, FCGR3B and HNA-4a modulate the oxidative burst of neutrophils in healthy and in SLE. Thus, this study contributes to the understanding of abnormalities in neutrophil functions in SLE.