Estudo da energia de ultra-som para a estimativa de retro-espalhamento invasiva em tecidos mediante temperatura

Dissertação de mest., Engenharia Eletrónica e Telecomunicações, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2012This experimental work is part of the application of ultrasound for hyperthermia (thermal therapy) aiming at treatment of cancer cells. The analysis of the back-scattered ultrasound energy enables the study of the temperature behavior induced by the ultrasonic signal in the tissues and it is the primary goal of this case study. To carry out this experiment we developed a gel-based phantom which mimics the behavior of human tissues under ultrasound signals. Subsequently, in order to obtain a more human like phantom the experiments were repeated with ex-vivo pork loin. The experiments involved ultrasonic therapeutic and imaging instrumentation connected to a function generator and a signal acquisition system. Experiments were performed considering different energies (0.5, 1, 1.5 and 2 W/cm3) of the therapeutic transducer and two emission frequencies of the image transducer (5 and 7 MHz). Five temperature sensors were used to measure the invasive temperature in the gel-based phantoms and two sensors in the experiments with pork loin. Analyzing the time delays in the echoes of the back-scattered ultrasonic signals of both types of phantoms we verified the relationship between temperature rise and the increase in the speed of propagation of the echoes. The assessment of variations in the back-scattered energy proved its dependency on the temperature applied in pork loin tissue, but no conclusion could be taken in the case of gel-based phantomEste trabalho experimental enquadra-se na aplicação de ultrassom para hipertermia (terapêutica térmica) com vista ao tratamento de células neoplásicas. A análise da energia do ultrassom retro-difundida possibilita o estudo do comportamento da variação de temperatura espalhada pelo sinal ultrassónico nos tecidos, constituindo o objetivo primordial deste trabalho. Para a realização das experiências foram desenvolvidos ‘phantoms’ baseados em agar-agar para mimificar o comportamento dos tecidos humanos com o ultrassom. Posteriormente, com vista a obter um ‘phantom’ mais próximo do tecido humano, as experiências foram repetidas com lombo de porco ex-vivo. As experiências envolveram instrumentação ultrassónica de terapêutica e de imagem, conectados a instrumentação de geração de funções e de aquisição de sinais. Foram realizadas experiências considerando diferentes energias (0.5, 1, 1.5 e 2 W/cm3) do transdutor de terapia e duas frequências de emissão do transdutor de imagem (5 e 7 MHz). Utilizaram-se 5 sensores de temperatura para medição invasiva da temperatura nos fantômas baseados em gel e dois sensores nas experiências com lombo de porco. Analisando os atrasos temporais nos ecos dos sinais ultrassónicos retro-espalhados para ambos os tipos de ‘phantoms’ verificou-se a relação entre o aumento de temperatura e o aumento da velocidade de propagação dos ecos. A análise das variações das energias retro-espalhadas provou ser dependente da temperatura aplicada no lombo de porco não sendo contudo conclusiva no caso dos ‘phantoms’ baseados em gel

Examination of Submental Space as an Alternative Method of Airway Assessment (Submental Sign)

<p>Abstract</p> <p>Background</p> <p>Difficult airway especially failed intubation has been associated with a high incidence of mortality and morbidity. Most of mortalities occur when an anaesthesiologist encounters an unanticipated difficult airway.</p> <p>Findings</p> <p>In 1999, a 23 yr. old, 65 kg weight and 170 cm height female patient had been scheduled for arthroscopy. Despite totally normal airway assessment (thyromental distance, mouth opening, jaw and neck movement ...) I was astonished by encountering a grade IV Cormack - Lehane laryngoscopic view. Tracheal intubation was impossible and ventilation was very difficult.</p> <p>On attempt to attain a better laryngoscopic view, while manipulating submandibular region I encountered a bulky noncompliant submental space (Submental Sign). This event made me more alert regarding this finding. Thereafter I noted for this sign throughout the past years and I found it very helpful.</p> <p>These findings encouraged me to write this report, and suggest a routine examination of submental space in order to keep the safety of the patient at the heart of the care we provide.</p> <p>Conclusion</p> <p>Evaluation of the submental space is suggested as an alternative predictor of difficult airway and routine examination of the submental space is of value in airway assessment.</p

Performance of Rhode Island Red, Black Australorp, and Naked Neck crossbreds under alternative production systems

The effects of the production system, breed cross, and their interaction on performance, egg quality, and hatching traits were evaluated. Rhode Island Red and Black Australorp were crossed with Naked Neck chickens (first generation RNN, and BNN, respectively). These crosses were mated among themselves and crossed to produce four crossbreds: RR (RNN x RNN), BB (BNN x BNN), RB (RNN x BNN), and BR (BNN x RNN). Thirty-six pullets and 9 cockerels from each crossbred were maintained in three production systems: the aviary system (AV), conventional cages (CC), and enriched cages (EC). Thus there were 48 pullets and 12 cockerels in each production system. Bodyweight, egg production percentage, and egg weight were highest in EC, followed by CC and AV. Higher egg weight, egg surface area, and egg volume were also observed in EC compared with CC and AV. Fertility and hatchability were higher and early embryonic mortality was lower in AV than in EC and CC. Bodyweight, egg production percentage, egg weight, egg volume, and surface area were higher for RB and BR than for BB and RR. Fertility and hatchability were similar for RB and BR. RR was similar to BR, but lower than RB. BB had the lowest fertility and hatchability. Thus, chickens in EC performed better than in the other systems, except that hatching traits were better in AV. RB and BR performed better than BB and RR.Key words: breed crosses, chicken, egg quality, hatchabilit

Pressure-induced insulating state in an organic superconductor

The electronic-transport properties of the quasi-two-dimensional organic superconductor β″–(BEDT-TTF)₂SF₅CH₂CF₂SO₃, where BEDT-TTF stands for bisethylenedithio-tetrathiafulvalene, have been investigated in magnetic fields up to 15 T and under hydrostatic pressure up to about 14 kbars. Shubnikov–de Haas data reveal a nonmonotonic pressure dependence of the holelike Fermi surface, a roughly linear increase of the electron g factor, and an approximately linear decrease of the cyclotron effective mass. By assuming that the latter reflects the pressure-induced reduction of the superconducting coupling parameter λ the rapid reduction of the superconducting transition temperature Tc(p) can be reasonably well described by the modified McMillan equation. Above about 12 kbars the material becomes insulating with an activated resistive behavior. This first-order metal-insulator transition has a hysteresis of about 3 kbars. This unexpected behavior is assumed to be of structural origin, although clear changes of electronic band-structure properties precede the phase transition

Systematics of g factors of 2_1^+ states in even-even nuclei from Gd to Pt: A microscopic description by the projected shell model

The systematics of g factor of first excited 2^+ state vs neutron number N is studied by the projected shell model. The study covers the even-even nuclei of all isotopic chains from Gd to Pt. g factors are calculated by using the many-body wavefunctions that reproduces well the energy levels and B(E2)'s of the ground-state bands. For Gd to W isotopes the characteristic feature of the g factor data along an isotopic chain is described by the present model. Deficiency of the model in the g factor description for the heavier Os and Pt isotopes is discussed.Comment: 9 pages, 5 figure

A Macroeconometric Model for Saudi Arabia

This Open Access Brief presents the KAPSARC Global Energy Macroeconometric Model (KGEMM). KGEMM is a policy analysis tool for examining the impacts of domestic policy measures and global economic and energy shocks on the Kingdom of Saudi Arabia. The model has eight blocks (real sector, fiscal, monetary, external sector, price, labor and wages, energy, population, and age cohorts) that interact with each other to represent the Kingdom’s macroeconomy and energy linkages. It captures New Keynesian demand-side features anchored to medium-run equilibrium and long-run aggregate supply. It applies a cointegration and equilibrium correction modeling (ECM) methodology to time series data to estimate the model’s behavioral equations in the framework of Autometrics, a general-to-specific econometric modeling strategy. Hence, the model combines ‘theory-driven’ approach with ‘data-driven’ approach. The Brief begins with an introduction to the theoretical framework of the model and the KGEMM methodology and then walks the reader through the structure of the model and its behavioral equations. The book closes with simulations showing the application of the model. Providing a detailed introduction to a cutting-edge, robust predictive model, this Brief will be of great use to researchers and policymakers interested in macroeconomics, energy economics, econometrics, and more specifically, the economy of Saudi Arabia

Genetic background influences tumour development in heterozygous Men1 knockout mice

Multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disorder caused by MEN1 germline mutations, is characterised by parathyroid, pancreatic and pituitary tumours. MEN1 mutations also cause familial isolated primary hyperparathyroidism (FIHP), a milder condition causing hyperparathyroidism only. Identical mutations can cause either MEN1 or FIHP in different families, thereby implicating a role for genetic modifiers in altering phenotypic expression of tumours. We therefore investigated the effects of genetic background and potential for genetic modifiers on tumour development in adult Men1+/- mice, which develop tumours of the parathyroids, pancreatic islets, anterior pituitary, adrenal cortex and gonads, that had been backcrossed to generate C57BL/6 and 129S6/SvEv congenic strains. A total of 275 Men1+/- mice, aged 5–26 months were macroscopically studied, and this revealed that genetic background significantly influenced the development of pituitary, adrenal and ovarian tumours, which occurred in mice over 12 months of age and more frequently in C57BL/6 females, 129S6/SvEv males and 129S6/SvEv females, respectively. Moreover, pituitary and adrenal tumours developed earlier, in C57BL/6 males and 129S6/SvEv females, respectively, and pancreatic and testicular tumours developed earlier in 129S6/SvEv males. Furthermore, glucagon-positive staining pancreatic tumours occurred more frequently in 129S6/SvEv Men1+/- mice. Whole genome sequence analysis of 129S6/SvEv and C57BL/6 Men1+/- mice revealed >54,000 different variants in >300 genes. These included, Coq7, Dmpk, Ccne2, Kras, Wnt2b, Il3ra and Tnfrsf10a, and qRT-PCR analysis revealed that Kras was significantly higher in pituitaries of male 129S6/SvEv mice. Thus, our results demonstrate that Kras and other genes could represent possible genetic modifiers of Men1

A 58-Year-Old Woman with Abdominal Symptoms and Elevated C-Reactive Protein

Babak Javid and colleagues discuss the differential diagnosis, investigation, and management of a woman with abdominal symptoms and a raised C-reactive protein