Tratamento Endovascular da Disseção Crónica Isolada da Aorta Abdominal

Isolated acute abdominal aortic dissection is a relatively rare event. Its natural history is not fully understood and its optimal treatment is not established. Open surgery represents the most described treatment but endovascular intervention has had increasing application. Isolated chronic abdominal aortic dissection is even less described in the literature. We describe three patients with isolated chronic abdominal aortic dissection who underwent endovascular treatment in our institution. Mean age at presentation was 82 years. Indication for surgical intervention was aneurismal degeneration. Mean aortic diameter at presentation was 46.7 mm. There was no perioperative mortality or reinterventions. Mean follow-up was 5.3 years (2-12 years). Late reintervention was needed in one patient, eight years after initial surgery, due to type 1 endoleak. According to our experience, endovascular intervention represents an effective and durable treatment option in isolated chronic abdominal aortic dissection. However, long-term follow-up is mandatory. Furthermore, larger studies are still needed to understand this disease and its adequate treatment.info:eu-repo/semantics/publishedVersio

Design of a biosynthetic pathway for curcumin production in Escherichia coli

Curcumin is the yellow pigment from turmeric, a well known culinary spice produced from the herb Curcuma longa. Research over the last years has shown that curcumin presents a wide range of pharmacological effects, including anti-inflammatory, anti-oxidant and anticarcinogenic activity. Given its potential application in cancer treatment, there is an interest for industrial production of this natural compound. This work consists on a synthetic biology approach for the design of a heterologous pathway for curcumin synthesis in Escherichia coli, a widely used microbe in industrial biotechnology. Using pathway databases and literature research we have selected the best gene candidates for heterologous expression of a curcumin synthesis pathway in E. coli. The DNA sequences for these genes were retrieved from public databases and can be readily synthesized for insertion into the host using molecular biology techniques. The inclusion of this pathway in a recent genome-scale reconstruction of the metabolism of E. coli has enabled the in silico analysis of the production capabilities for this host. We have analysed the theoretical production yields and biomass growth under different experimental conditions. Using this model we have also searched for potential gene knockouts that partially redirect the metabolic flux to the heterologous pathway without compromising cellular growth. In overall, the methods used in this work allow the selection of the most suitable combination of experimental conditions and genetic manipulations for the design of an efficient biosynthetic pathway for curcumin production in E.coli

Particle acceleration

Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV

Development of an electrochemical immunosensor for Phakopsora pachyrhizi detection in the early diagnosis of soybean rust

Soybean rust is a disease that occurs on soybean leaves and is considered very aggressive, reducing product quality. Early identification of fungus in the plants prevents severe farming losses as well as spreading to neighboring cultures. In this paper, a label-free immunosensor was developed based on impedance measurements to detect Asian rust on soybean leaf extract at the early stages of the disease. The antibody anti-mycelium of Phakopsora pachyrhizi fungus (disease agent) was immobilized on a gold substrate via a self-assembled monolayer (SAM) of thiols using covalent cysteamine coupling. This immunosensor presents a limit of detection of 385 ng mL-1. The optimization of experimental conditions and surface blocking to minimize non-specific adsorption on the immunosensor response were evaluated. These studies, based on electrochemical impedance spectroscopy (EIS), provide new perspectives on using this method for early diagnosis of soybean rust

Evidence of Low-Temperature Superparamagnetism in Mn3O_{3}O_{4}$ Nanoparticle Ensembles

Please refer to the abstract within the main body of the paper

EXPERIMENTAL STUDY TO DETERMINE THE LOCAL CONDENSATION HEAT TRANSFER COEFFICIENTE FOR R134A FLOWING THROUGH A 4.8 MM INTERNAL DIAMETER SMOOTH HORIZONTAL TUBE

Refrigerant fluid R134a is commonly one of the most utilised invapour compression cycles wordlide, wheter in dommestic HVAC orautomotive regrigeration systems. This paper’s goal is toexperimetnally determine the fluid local condensation Heat TransferCoefficient (HTC), in several flor regimes. In this work, the mass fluxwas equal to 200, 250 and 300 kg/(m2s) and the fluid flowedthrough a smooth, horizontal 4.8 mm internal diameter aluminiumpipe, during which its vapour quality varied along the entire qualityrange. A purpose built test rig was developed, in which fluidconditions were constantly monitored and controlled. Throughmeasurements in temperature and pressure, an energy balance wasused to calculate experimentally the local heat transfer coeeficient.Average results for the unit quality range equalled to 3781 , 3459 and3944 W/m2K for saturation temperature equal to 30 C and theaforementioned mass velocities. Likewise, at 35C the averages HTCfound were 2903, 3141 and 3898 W/m2K at the same mass fluxrates. Later on, the experimental results were compared to tencommonly used HTC correlation found in relevant references,with Chato’s correlation returning the best fitting

Cryptosporidiosis Among HIV-infected Patients with Diarrhea in Edo State, Midwesten Nigeria

To determine the prevalence of cryptosporidiosis among HIV infected and HIV non-infected patients with diarrhea in Edo State, Nigeria, as well as the effect of CD4+ lymphocyte count on the prevalence of cryptosporidial infection among the HIV patients. Stool samples were collected from 300 patients consisting of 200 HIV-infected and 100 HIV non-infected patients with diarrhea. Blood samples were collected from the HIV-infected patients. The stool samples were processed to detect Cryptosporidium species using a modified Ziehl-Neelsen stain, as well as other intestinal parasites using saline and iodine preparations. The blood samples were used to determine CD4+ lymphocyte count. The prevalence of intestinal parasites was higher in HIV-infected patients compared with their HIV non-infected counterparts (39% vs 24% respectively, p=0.0097). Cryptosporidiosis was diagnosed only among HIV-infected patients and was the only parasite whose prevalence was significantly different between HIV-infected and HIV non-infected patients. CD4+ lymphocyte count of <200 cells/µL among HIV-infected was a risk factor for acquiring cryptosporidial infection (OR=18.776, 95% CI=6.299, 55.964). A cryptosporidial infection prevalence of 18% among HIV-infected patients was observed and CD4+ count of <200 cells/µL was a risk factor for acquiring the disease. Routine examination of diarrhogenic stools of HIVinfected patients for cryptosporidiosis is advocated

EXPERIMENTAL STUDY OF THE PRESSURE DROP OF THE ECOFLUID R1234YF COMPARED TO THE FLUID R134A IN SMOOTH TUBES WITH 4.8MM INTERNAL DIAMMETER

The refrigerant fluid R1234yf is a hydrofluorefine with zero potential for degradation of the ozone layer and low potential for global warming. It is one of the potential substitutes for the currently used R134a in automotive systems. In this work, the pressure drop suffered by the fluids R134a and R1234yf when flowing in a test section through a pipe with a 4.8 mm internal diameter was measured. The pressure drop was plotted as a function of the void fraction at the exit of the test section and the values were compared concerning the change in mass flux, change in saturation temperature, and comparatively between R1234yf and R134a. A significant increase in pressure drop was observed by the increases of the mass flux, showing an increment of 155.46% of the pressure loss from 200 to 300 kg·m-2·s-1 for R1234yf at 35ºC and 161.07% for R134a in the same conditions. Despite being high, those values are expected since increasing mass flux also increases the friction between both phases. On the other hand, by increasing the saturation temperature, the pressure drop is slightly lower once the differences between the densities of the liquid and vapor phases are reduced. Compared with R134a, the R1234yf ecofluid presents less pressure drop, showing a reduction of 24% for 300 kg·m-2·s-1