963 resultados para Wall linings
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Background: Gender differences are expected to influence the pattern and outcome of management of abdominal wall hernias. Some of these are left to speculations with few published articles on hernias in females. Objectives: To describe the clinical pattern of abdominal wall hernias in females. Method: A 5 year retrospective review. Result: There were 181 female patients with 184 hernias representing 27.9% of the total number of hernia patients operated. Mean age was 41.66±24.46 years with a bimodal peak in the 1st and 7th decades. Inguinal hernia accounted for majority (50.5%) but incisional hernia predominated in the 30-49 age group, while only inguinal and umbilical hernias were seen in the first two decades (p=0.04). There was no side predilection in the cases of inguinal hernia. There were 12 (6.6%) emergency presentations, most of which occurred in the 6th decade and above and none below 30 years (p=0.02). Umbilical (4 cases) and femoral hernias (3 cases) accounted for most of these cases. Incisional hernia was the commonest cause of recurrent hernias. Conclusion: Inguinal hernia is the commonest hernia type in females followed by incisional hernias which also accounteds for most recurrent cases. Age appears to be a risk factor for developing complications.
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International audience
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Survey map.
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This paper analyzes whether a company’s image affects its capability of attracting young employees. To do so, the process that leads to the creation of a company’s image by young professionals and the relevance they attribute to companies’ websites were addressed. By using the websites of 20 companies and conducting 12 semi structured interviews near recent graduates, it was possible to conclude that companies and young professionals seek different sources when it comes to form an image of a company and hence, what is perceived by companies as relevant to be communicated, is disregarded by young professionals given its indistinctiveness.
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Strawberry (Fragaria x ananassa, Duch.) fruit is characterized by its fast ripening and soft texture at the ripen stage, resulting in a short postharvest shelf life and high economic losses. It is generally believed that the disassembly of cell walls, the dissolution of the middle lamella and the reduction of cell turgor are the main factors determining the softening of fleshy fruits. In strawberry, several studies indicate that the solubilisation and depolymerisation of pectins, as well as the depolymerisation of xyloglucans, are the main processes occurring during ripening. Functional analyses of genes encoding pectinases such as polygalacturonase and pectate lyase also point out to the pectin fraction as a key factor involved in textural changes. All these studies have been performed with whole fruits, a complex organ containing different tissues that differ in their cell wall composition and undergo ripening at different rates. Cell cultures derived from fruits have been proposed as model systems for the study of several processes occurring during fruit ripening, such as the production of anthocyanin and its regulation by plant hormones. The main objective of this research was to obtain and characterize strawberry cell cultures to evaluate their potential use as a model for the study of the cell wall disassembly process associate with fruit ripening. Cell cultures were obtained from cortical tissue of strawberry fruits, cv. Chandler, at the stages of unripe-green, white and mature-red. Additionally, a cell culture line derived from strawberry leaves was obtained. All cultures were maintained in solid medium supplemented with 2.5 mg.l-1 2,4-D and incubated in the dark. Cell walls from the different callus lines were extracted and fractionated to obtain CDTA and sodium carbonate soluble pectin fractions, which represent polyuronides located in the middle lamella or the primary cell wall, respectively. The amounts of homogalacturonan in both fractions were estimated by ELISA using LM19 and LM20 antibodies, specific against demethylated and methyl-esterified homogalacturonan, respectively. In the CDTA fraction, the cell line from ripe fruit showed a significant lower amount of demethylated pectins than the rest of lines. By contrast, the content of methylated pectins was similar in green- and red-fruit lines, and lower than in white-fruit and leaf lines. In the sodium carbonate pectin fraction, the line from red fruit also showed the lowest amount of pectins. These preliminary results indicate that cell cultures obtained from fruits at different developmental stages differ in their cell wall composition and these differences resemble to some extent the changes that occur during strawberry softening. Experiments are in progress to further characterize cell wall extracts with monoclonal antibodies against other cell wall epitopes.
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Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia - UL
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Purpose: To investigate the anti-arthritic activity of the water extract of Rhizoma Arisaematis (WERA) using a collagen II -induced arthritis (CIA) rat model. Methods: CIA was induced in male Sprague-Dawley rats by intradermal injection of bovine collagen II in Complete Freund’s Adjuvant. The rats were treated with daily oral doses of WERA (100, 200, and 400 mg/kg) for 21 consecutive days. Methotrexate (MTX, 3 mg/kg), used as a positive control, was administered orally 2 times/week for 3 weeks. The severity of arthritis was evaluated using indices of paw swelling, arthritic score, body weight, thymus index, and spleen index. In addition, the serum levels of IL-1β, IL-6, IL-10, and TNF-α were measured. Results: All doses of WERA significantly inhibited paw edema (p < 0.01), decreased arthritis scores (p < 0.01) and spleen index (p < 0.05), and alleviated the weight loss associated with CIA in rats. Furthermore, TNF-α, IL-1β, and IL-6 serum levels were significantly decreased (p < 0.05) by all doses of WERA. By contrast, IL-10 serum levels were markedly increased (p < 0.05). Conclusion: WERA exerts therapeutic effects in CIA in rats by decreasing the serum levels of TNF-α, IL-1β, IL-6 and IL-10, suggesting WERA may be an effective candidate drug for treating human rheumatoid arthritis.
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Laboratory chamber experiments are used to investigate formation of secondary organic aerosol (SOA) from biogenic and anthropogenic precursors under a variety of environmental conditions. Simulations of these experiments test our understanding of the prevailing chemistry of SOA formation as well as the dynamic processes occurring in the chamber itself. One dynamic process occurring in the chamber that was only recently recognized is the deposition of vapor species to the Teflon walls of the chamber. Low-volatility products formed from the oxidation of volatile organic compounds (VOCs) deposit on the walls rather than forming SOA, decreasing the amount of SOA formed (quantified as the SOA yield: mass of SOA formed per mass of VOC reacted). In this work, several modeling studies are presented that address the effect of vapor wall deposition on SOA formation in chambers.
A coupled vapor-particle dynamics model is used to examine the competition among the rates of gas-phase oxidation to low volatility products, wall deposition of these products, and mass transfer to the particle phase. The relative time scales of these rates control the amount of SOA formed by affecting the influence of vapor wall deposition. Simulations show that an effect on SOA yield of changing the vapor-particle mass transfer rate is only observed when SOA formation is kinetically limited. For systems with kinetically limited SOA formation, increasing the rate of vapor-particle mass transfer by increasing the concentration of seed particles is an effective way to minimize the effect of vapor wall deposition.
This coupled vapor-particle dynamics model is then applied to α-pinene ozonolysis SOA experiments. Experiments show that the SOA yield is affected when changing the oxidation rate but not when changing the rate of gas-particle mass transfer by changing the concentration of seed particles. Model simulations show that the absence of an effect of changing the seed particle concentration is consistent with SOA formation being governed by quasi-equilibrium growth, in which gas-particle equilibrium is established much faster than the rate of change of the gas-phase concentration. The observed effect of oxidation rate on SOA yield arises due to the presence of vapor wall deposition: gas-phase oxidation products are produced more quickly and condense preferentially onto seed particles before being lost to the walls. Therefore, for α-pinene ozonolysis, increasing the oxidation rate is the most effective way to mitigate the influence of vapor wall deposition.
Finally, the detailed model GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) is used to simulate α-pinene photooxidation SOA experiments. Unexpectedly, α-pinene OH oxidation experiments show no effect when changing either the oxidation rate or the vapor-particle mass transfer rate, whereas GECKO-A predicts that changing the oxidation rate should drastically affect the SOA yield. Sensitivity studies show that the assumed magnitude of the vapor wall deposition rate can greatly affect conclusions drawn from comparisons between simulations and experiments. If vapor wall loss in the Caltech chamber is of order 10-5 s-1, GECKO-A greatly overpredicts SOA during high UV experiments, likely due to an overprediction of second-generation products. However, if instead vapor wall loss in the Caltech chamber is of order 10-3 s-1, GECKO-A greatly underpredicts SOA during low UV experiments, possibly due to missing autoxidation pathways in the α-pinene mechanism.
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The complex and essential cell wall of Mycobacterium tuberculosis represents a plethora of new and old drug targets that collectively form an apparent mycobacterial “Achilles’ heel”. The mycolic acids are long-chain α-alkyl-β-hydroxy fatty acids (C70–90), which are unique to mycobacterial species, forming an integral component of the mycolyl–arabinogalactan–peptidoglycan complex. Their apparent uniqueness to the M. tuberculosis complex has rendered components of mycolic acid biosynthesis as powerful drug targets for specific tuberculosis (TB) chemotherapy. Here, I will discuss a contribution to TB drug discovery by deconvolution of the inhibitory mechanisms of a number of antitubercular compounds targeting mycolic acid biosynthesis. I will begin with the early days, elucidating the mode of action of ethionamide [1] and thiolactomycin [2], each targeting two separate components of the fatty acid synthase II (FAS-II) pathway. I will further discuss the recently discovered tetrahydropyrazo[1,5-a]pyrimidine-3-carboxamide compounds [3] which selectively target the essential, catalytically silent M. tuberculosis EchA6, providing a crucial lipid shunt between β-oxidation and FAS-II and supplying lipid precursors for essential mycolate biosynthesis. Finally, I will discuss the recent discovery of the mode of action of the indazole sulfonamides [4], inhibiting M. tuberculosis KasA by, a completely novel inhibitory mechanism.
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Abstract : Recently, there is a great interest to study the flow characteristics of suspensions in different environmental and industrial applications, such as snow avalanches, debris flows, hydrotransport systems, and material casting processes. Regarding rheological aspects, the majority of these suspensions, such as fresh concrete, behave mostly as non-Newtonian fluids. Concrete is the most widely used construction material in the world. Due to the limitations that exist in terms of workability and formwork filling abilities of normal concrete, a new class of concrete that is able to flow under its own weight, especially through narrow gaps in the congested areas of the formwork was developed. Accordingly, self-consolidating concrete (SCC) is a novel construction material that is gaining market acceptance in various applications. Higher fluidity characteristics of SCC enable it to be used in a number of special applications, such as densely reinforced sections. However, higher flowability of SCC makes it more sensitive to segregation of coarse particles during flow (i.e., dynamic segregation) and thereafter at rest (i.e., static segregation). Dynamic segregation can increase when SCC flows over a long distance or in the presence of obstacles. Therefore, there is always a need to establish a trade-off between the flowability, passing ability, and stability properties of SCC suspensions. This should be taken into consideration to design the casting process and the mixture proportioning of SCC. This is called “workability design” of SCC. An efficient and non-expensive workability design approach consists of the prediction and optimization of the workability of the concrete mixtures for the selected construction processes, such as transportation, pumping, casting, compaction, and finishing. Indeed, the mixture proportioning of SCC should ensure the construction quality demands, such as demanded levels of flowability, passing ability, filling ability, and stability (dynamic and static). This is necessary to develop some theoretical tools to assess under what conditions the construction quality demands are satisfied. Accordingly, this thesis is dedicated to carry out analytical and numerical simulations to predict flow performance of SCC under different casting processes, such as pumping and tremie applications, or casting using buckets. The L-Box and T-Box set-ups can evaluate flow performance properties of SCC (e.g., flowability, passing ability, filling ability, shear-induced and gravitational dynamic segregation) in casting process of wall and beam elements. The specific objective of the study consists of relating numerical results of flow simulation of SCC in L-Box and T-Box test set-ups, reported in this thesis, to the flow performance properties of SCC during casting. Accordingly, the SCC is modeled as a heterogeneous material. Furthermore, an analytical model is proposed to predict flow performance of SCC in L-Box set-up using the Dam Break Theory. On the other hand, results of the numerical simulation of SCC casting in a reinforced beam are verified by experimental free surface profiles. The results of numerical simulations of SCC casting (modeled as a single homogeneous fluid), are used to determine the critical zones corresponding to the higher risks of segregation and blocking. The effects of rheological parameters, density, particle contents, distribution of reinforcing bars, and particle-bar interactions on flow performance of SCC are evaluated using CFD simulations of SCC flow in L-Box and T-box test set-ups (modeled as a heterogeneous material). Two new approaches are proposed to classify the SCC mixtures based on filling ability and performability properties, as a contribution of flowability, passing ability, and dynamic stability of SCC.
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This study reports alternation of D2 extension-related and D3 contraction-related microfabrics in the northern hanging wall block of a gneiss dome-like structure recognized in the Évora Massif (Ossa-Morena Zone). In the Arraiolos – Santo Antonio de Alcorrego traverse high- to low-grade mylonites are dominant. Microfabrics related to D2 ductile deformation and M2 high-amphibolite to greenschist facies characterize an extensional shear zone with telescoping metamorphic isograds. D2 microstructures indicate shear sense with top-to-SE. Superposition of D3 contraction developed under greenschist facies (M3) producing folding of D2 microfabrics, mylonitization of granites along strike-slip shear zones and retrogression of M2 mineral assemblages.
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2016
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Nowadays the development of new Internal Combustion Engines is mainly driven by the need to reduce tailpipe emissions of pollutants, Green-House Gases and avoid the fossil fuels wasting. The design of dimension and shape of the combustion chamber together with the implementation of different injection strategies e.g., injection timing, spray targeting, higher injection pressure, play a key role in the accomplishment of the aforementioned targets. As far as the match between the fuel injection and evaporation and the combustion chamber shape is concerned, the assessment of the interaction between the liquid fuel spray and the engine walls in gasoline direct injection engines is crucial. The use of numerical simulations is an acknowledged technique to support the study of new technological solutions such as the design of new gasoline blends and of tailored injection strategies to pursue the target mixture formation. The current simulation framework lacks a well-defined best practice for the liquid fuel spray interaction simulation, which is a complex multi-physics problem. This thesis deals with the development of robust methodologies to approach the numerical simulation of the liquid fuel spray interaction with walls and lubricants. The accomplishment of this task was divided into three tasks: i) setup and validation of spray-wall impingement three-dimensional CFD spray simulations; ii) development of a one-dimensional model describing the liquid fuel – lubricant oil interaction; iii) development of a machine learning based algorithm aimed to define which mixture of known pure components mimics the physical behaviour of the real gasoline for the simulation of the liquid fuel spray interaction.
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Objectives: To investigate the use of intravascular optical coherence tomography (IVOCT) for carotid artery stenting (CAS) procedures in patients with atherosclerotic stenosis. Examine possible markers that might identify the onset of new cerebral ischemic lesions on MRI. Specifically, attention was drawn to the morphological features of the used dual layer stent, which could be underestimated during traditional CAS procedures. Secondary goals are to compare the safety and efficacy of different CAS techniques and the accuracy of the vessel analysis software’s on pre-operative CTA examination used to quantify ICA stenosis with the gold standard IVOCT. Material and Methods: Ten patients underwent CAS procedure with flow-arrest technique and IVOCT evaluations prior to and following stent deployment, while five matched patients underwent CAS procedure with distal embolic protection device (EPD) technique. All patients underwent 24-hours 3T MRI examination to check for ischemic lesions; all patients were treated with the same dual-layer stent. Results: Patients with new ischemic lesions demonstrated peculiar stent configuration in the distal end, and a strong Spearman’s rank order correlation was found among the volume of new DWI lesions and the stent configuration in its distal end (Rs: 0.81; p <0.001). No statistically significant differences were observed in the total burden of new ischemic lesions for each technique. The vessel analysis software's on CTA comparison demonstrated a higher diagnostic accuracy in the degree of ICA stenosis compared to the gold standard of IVOCT of the specialized software (ROC curve = 0.63; p = 0.06) compared to the general software (ROC curve = 0.57, p = 0.31). Conclusions: Study’s results support the use of IVOCT to allow recognition of potential features that can predict the onset of new cerebral ischemic lesions. Additionally, IVOCT made it possible to evaluate specialized software's increased accuracy in the pre-operative evaluation of ICA atherosclerotic stenosis.
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Desmoid tumor (DT) is a common manifestation of Gardner's Syndrome (GS), although it is a rare condition in the general population. DT in patients with GS is usually located in the abdominal wall and/or intra-abdominal cavity. We report a case of a 32 years-old female patient with familial adenomatous polyposis (FAP), who was already submitted to total colectomy and developed multiple DT, located in the abdominal wall and in the left breast. The patient underwent several surgical procedures, with a multidisciplinary team of surgeons. Wide surgical resections of the left breast and the abdominal wall tumors were performed in separate steps. Polypropylene mesh reconstruction and muscle flaps were needed to cover the defects of the thoracic and abdominal walls. After partial necrosis of the adipose-cutaneous flap in the abdomen that required a new skin graft, she had a satisfactory outcome with complete healing of the surgical incisions. DT is frequent in GS, however, breast localization is very rare, with few cases reported in the literature. Recurrence of DT is not negligible, even after a wide surgical resection. GS patients must be followed up closely, and clinical examination, associated with imaging studies, should be performed to detect any signs of tumor. DT represents one of the most significant causes of the morbidity and mortality that affects FAP patients following colectomy. In general, the surgical procedures to excise DT are highly complex, requiring a multidisciplinary team.