Revealing fungal activity in the presence of ionic liquids

Dissertation presented to obtain the Ph.D degree in Biochemistry

Analysis of the intranuclear life of nonsense transcripts

Dissertação para obtenção do Grau de Doutor em Biologia, Especialidade de Biologia Molecular

Numerical Evaluation of Ventilation Performance in Children Day Care Centres

Modelling of ventilation is strongly dependent on the physical characteristics of the building of which precise evaluation is a complex and time consuming task. In the frame of a research project, two children day care centres (CDCC) have been selected in order to measure the envelope air permeability, the flow rate of mechanical ventilation systems and indoor and outdoor temperature. The data obtained was used as input to the computer code CONTAM for ventilation simulations. The results obtained were compared with direct measurements of ventilation flow from short term measurements with CO2 tracer gas and medium term measurements with perfluorocarbon tracer (PFT) gas decay method. After validation, in order to analyse the main parameters that affect ventilation, the model was used to predict the ventilation rates for a wide range of conditions. The purpose of this assessment was to find the best practices to improve natural ventilation. A simple analytical method to predict the ventilation flow rate of rooms is also presented. The method is based on the estimation of wind effect on the room through the evaluation of an average factor and on the assessment of relevant cross section of gaps and openings combined in series or in parallel. It is shown that it may be applied with acceptable accuracy for this type of buildings when ventilation is due essentially to wind action.

Repair mortars for rammed earth constructions

Proceedingsof the XII DBMC – 12th International Conference on Durability of Building Materials and Components, Vol.2, Porto, FEUP, March 2011, p.689-696

Nanobiophotonics for biomolecular diagnostics

Dissertação para obtenção do Grau de Doutor em Biotecnologia

Characterization of sol-gel matrices with entrapped cutinase

Dissertação para obtenção do Grau de Doutor em Engenharia Química e Bioquímica

The Role of Small RNAs and Ribonucleases in the Control of Gene Expression in Salmonella Typhimurium

Dissertation presented to obtain the Ph.D degree in Biology

Interplay of Exoribonucleases, Hfq and Small RNAs Structural Determinants in the Control of Gene Expression

Dissertation presented to obtain the Ph.D degree in Biology

Troia Roman baths (Portugal) – Assessment of history of interventions

International Seminar in Conservation. A Tribute to Cesari Brandi. Lisboa, LNEC, May 2006, p.273-282

Experimentation with accumulation

We study signal-dependent experimentation in the presence of accumulation and show that the passive-learner’s action surprisingly coincides with the experimentor’s when the unknown term is the one determining the decay rate of the stock, while they differ when the parameter being learned is the one measuring the accumulation rate. These results highlight the importance of the dynamic structure of the problem in signal-dependent experimentation. Moreover, they have important consequences for the pollution-accumulation debate currently in progress.

Controlling gene expression in enterobacteriaceae: studies on sRNAs and strategies for synthetic biology

Dissertation presented to obtain the Master Degree in Molecular, Genetics and Biomedicine

The effect of key process operational conditions on enhanced biological phosphorus removal from wastewater

Enhanced biological phosphorus removal (EBPR) is the most economic and sustainable option used in wastewater treatment plants (WWTPs) for phosphorus removal. In this process it is important to control the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), since EBPR deterioration or failure can be related with the proliferation of GAOs over PAOs. This thesis is focused on the effect of operational conditions (volatile fatty acid (VFA) composition, dissolved oxygen (DO) concentration and organic carbon loading) on PAO and GAO metabolism. The knowledge about the effect of these operational conditions on EBPR metabolism is very important, since they represent key factors that impact WWTPs performance and sustainability. Substrate competition between the anaerobic uptake of acetate and propionate (the main VFAs present in WWTPs) was shown in this work to be a relevant factor affecting PAO metabolism, and a metabolic model was developed that successfully describes this effect. Interestingly, the aerobic metabolism of PAOs was not affected by different VFA compositions, since the aerobic kinetic parameters for phosphorus uptake, polyhydroxyalkanoates (PHAs) degradation and glycogen production were relatively independent of acetate or propionate concentration. This is very relevant for WWTPs, since it will simplify the calibration procedure for metabolic models, facilitating their use for full-scale systems. The DO concentration and aerobic hydraulic retention time (HRT) affected the PAO-GAO competition, where low DO levels or lower aerobic HRT was more favourable for PAOs than GAOs. Indeed, the oxygen affinity coefficient was significantly higher for GAOs than PAOs, showing that PAOs were far superior at scavenging for the often limited oxygen levels in WWTPs. The operation of WWTPs with low aeration is of high importance for full-scale systems, since it decreases the energetic costs and can potentially improve WWTP sustainability. Extended periods of low organic carbon load, which are the most common conditions that exist in full-scale WWTPs, also had an impact on PAO and GAO activity. GAOs exhibited a substantially higher biomass decay rate as compared to PAOs under these conditions, which revealed a higher survival capacity for PAOs, representing an advantage for PAOs in EBPR processes. This superior survival capacity of PAOs under conditions more closely resembling a full-scale environment was linked with their ability to maintain a residual level of PHA reserves for longer than GAOs, providing them with an effective energy source for aerobic maintenance processes. Overall, this work shows that each of these key operational conditions play an important role in the PAO-GAO competition and should be considered in WWTP models in order to improve EBPR processes.

Fishing the key biological components of the bacterium Geobacter metallireducens for optimal biotechnological applications

Os resultados apresentados no capítulo 2 foram incluídos no artigo Dantas JM, Campelo LM, Duke NEC, Salgueiro CA, Pokkuluri PR (2015) "The structure of PccH from Geobacter sulfurreducens – a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode", FEBS Journal, 282, 2215-2231.

Pelvic lymphoscintigraphy: contribution to the preoperative staging of rectal cancer

PURPOSE: Preservation of the anal sphincter in surgery for cancer of the distal rectum in an attempt to avoid colostomy has been a main concern of colorectal surgeons. Various proposed procedures contradict oncological principles, especially with respect to pelvic lymphadenectomy. Therefore, prior knowledge of pelvic lymph node involvement is an important factor in choosing the operative technique, i.e., radical or conservative resection. Introduction of ultrasound, computerized tomography, and magnetic resonance have made preoperative study of the area possible. Nevertheless, these resources offer information of an anatomical nature only. Lymphoscintigraphy enables the morphological and functional evaluation of the pelvic area and contributes toward complementing the data obtained with the other imaging techniques. The objective of this prospective study is twofold: to standardize the lymphoscintigraphy technique and to use it to differentiate patients with rectal cancer from those with other coloproctologic diseases. CASUISTIC AND METHODS: Sixty patients with various coloproctologic diseases were studied prospectively. Ages ranged from 21 to 96 years (average, 51 and median, 55 years). Twenty-six patients were male and 34 were female. Thirty patients had carcinoma of the distal rectum as diagnosed by proctologic and anatomic-pathologic examinations, 20 patients had hemorrhoids, 5 had chagasic megacolon, 2 had diverticular disease, 2 had neoplasm of the right colon, and 1 had ulcerative colitis as diagnosed by proctologic exam and/or enema. The lymphoscintigraphy method consisted of injecting 0.25 mL of a dextran solution marked with radioactive technetium-99m into the right and left sides of the perianal region and obtaining images with a gamma camera. The results were analyzed statistically with a confidence level of 95% (P < .05) using the following statistical techniques: arithmetic and medium average, Fisher exact test, chi-square test corrected for continuity according to Yates, and distribution tables for the number of patients. RESULTS: In rectal cancer, the tracer progresses unilaterally or is absent; in other patients, the progress of the tracer is bilateral and symmetrical, although its progress may be slow. Statistical tests showed with high significance that the agreement index between the clinical diagnosis and the result of the lymphoscintigraphic exam was 93%. CONCLUSIONS: Lymphoscintigraphy is a standardized, painless, and harmless test that can be performed in all cases; it differentiates patients with rectal cancer from those with other coloproctological diseases.