631 research outputs found
The Hilbert curve of a 4-dimensional scroll with a divisorial fiber
In dimension n = 2m 12 2 65 4 adjunction theoretic scrolls over a smooth mfold may not be classical scrolls, due to the existence of divisorial fibers. A 4-dimensional scroll (X, L) over P 3 of this type is considered, and the equation of its Hilbert curve \u393 is determined in two ways, one of which relies on the fact that (X, L) is at the same time a classical scroll over a threefold Y 6= P 3 . It turns out that \u393 does not perceive divisorial fibers. The equation we obtain also shows that a question raised in [4] has negative answer in general for non-classical scrolls over a 3-fold. More precisely, the answer for (X, L) is negative or positive according to whether (X, L) is regarded as an adjunction theoretic scroll or as a classical scroll; in other words, it is the answer to this question to distinguish between the existence of jumping fibers or not
Influence of Diabetes on Implant Failure and Peri-Implant Diseases: A Retrospective Study
Diabetes is an important modifying factor of periodontitis, but its association with peri-implant diseases has not been fully explored and the existing literature reports controversial results. The aim of this retrospective study was to evaluate the influence of diabetes on peri-implantitis and implant failure. Smoking status, history of periodontal disease, presence of diabetes, diabetes type, therapy and glycaemia levels were collected in a total of 204 subjects treated with 929 implants, with a mean follow-up time of 5.7 \ub1 3.82 years after loading. Odds ratio (OR) for diabetes as a direct cause of peri-implantitis and implant failure were calculated, adjusted for smoking status and history of periodontitis. Nineteen patients were diabetic and most of them presented a good control of the disease at the time of surgery. The overall patient-level prevalence of peri-implantitis was 11.3%. Among diabetic patients, one developed peri-implantitis, whereas one experienced multiple implant failures. The calculated ORs, adjusted for smoking status and periodontitis, were not statistically significant. The results revealed no association between diabetes and peri-implantitis or implant failure coherently with the existing scientific literature. The actual influence of hyperglycemia on implant failure is still uncertain and new studies with larger cohorts of patients are needed
Sugarcane cultivars present differential susceptibility to herbicides ametryn and trifloxysulfuron-sodium.
Weed management in Brazilian sugarcane fields is accomplished mainly with herbicides. These chemical products may negatively impact sugarcane growth and development. Therefore, we aimed this study to evaluate the influence of the selective herbicides ametryn, trifloxysulfurom-sodium and its commercially available mixture on the growth of sugarcane cultivars. The experiment was conducted under greenhouse condition in a completely randomized design, using a 3×3×4 factorial scheme with four replications. Factor A comprised sugarcane cultivars (SP80-1816, RB855113 and RB867515); factor B herbicides ametryn (Metrimex®), trifloxysulfuron-sodium (Envoke®) and its mixture (Krismat®), and factor C the doses (0.0, 0.5x, 1.0x and 3.0x the label dose), where 1.0x dose= 2,000gha-1 for ametryn; 22.5gha-1 for trifloxysulfuron-sodium and 1, 463+37.0gha-1 for the mixture. Crop toxicity was assessed 28 days after herbicide application and traits such as plant height, number of leaves per plant, stalk diameter, leaf area index, specific leaf area and crop growth rate were assessed 80 days after crop emergence. The results showed that trifloxysulfuron-sodium causes lower impact on all variables; therefore, being more selective to all cultivars. The label dose (1.0x), equivalent to 2,000 gha-1 of ametryn and 22.5 gha-1 of trifloxysulfuron- sodium is considered as a threshold between deficient weed control (in lower doses) and excessive crop toxicity (in higher doses). RB867515 and RB855113, respectively, were the most and least tolerant cultivars to both herbicides. In highly infested planting fields, farmers usually prefer to grow the most tolerant sugarcane cultivar when applying ametryn or trifloxysulfurom sodium
Blended Cements Elaborated with Kaolinitic Calcined Clays
In the clinker production process, the main component of Portland cement (PC), large amount of CO2 are emitted into the atmosphere. The use of calcined kaolinitic clays as supplementary material of cement is an alternative to mitigate the environmental impact. In this paper, the influence of the replacement of PC by two calcined kaolinitic clays (15 and 30%), with high content of metakaolinite and different reactivity was studied. Calcined kaolinitic clays were characterized, the pozzolanic activity using Frattini test, the compressive strength, rate of water absorption (sorptivity), the assemblage of hydration products and the pore size distribution were determined at 28 days. The results show that the replacement of high percentage (30%) of very reactive clays improves the mechanical behavior and durable parameters compared with those obtained for plain PC.Centro de Tecnología de Recursos Minerales y Cerámic
A Translational Murine Model of Sub-Lethal Intoxication with Shiga Toxin 2 Reveals Novel Ultrastructural Findings in the Brain Striatum
Infection by Shiga toxin-producing Escherichia coli causes hemorrhagic colitis, hemolytic uremic syndrome (HUS), acute renal failure, and also central nervous system complications in around 30% of the children affected. Besides, neurological deficits are one of the most unrepairable and untreatable outcomes of HUS. Study of the striatum is relevant because basal ganglia are one of the brain areas most commonly affected in patients that have suffered from HUS and since the deleterious effects of a sub-lethal dose of Shiga toxin have never been studied in the striatum, the purpose of this study was to attempt to simulate an infection by Shiga toxin-producing E. coli in a murine model. To this end, intravenous administration of a sub-lethal dose of Shiga toxin 2 (0.5 ηg per mouse) was used and the correlation between neurological manifestations and ultrastructural changes in striatal brain cells was studied in detail. Neurological manifestations included significant motor behavior abnormalities in spontaneous motor activity, gait, pelvic elevation and hind limb activity eight days after administration of the toxin. Transmission electron microscopy revealed that the toxin caused early perivascular edema two days after administration, as well as significant damage in astrocytes four days after administration and significant damage in neurons and oligodendrocytes eight days after administration. Interrupted synapses and mast cell extravasation were also found eight days after administration of the toxin. We thus conclude that the chronological order of events observed in the striatum could explain the neurological disorders found eight days after administration of the toxin.Fil: Tironi Farinati, Alicia Carla Flavia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Geoghegan, Patricia A.. Ministerio de Salud de la Nación. Administración Nacional de Laboratorios e Institutos de Salud; ArgentinaFil: Cangelosi, Adriana. Ministerio de Salud de la Nación. Administración Nacional de Laboratorios e Institutos de Salud; ArgentinaFil: Pinto, Alipio. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Fisiología. Laboratorio de Neurofisiopatología; ArgentinaFil: Loidl, Cesar Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencias.;Fil: Goldstein, Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Fisiología. Laboratorio de Neurofisiopatología; Argentin
Fine needle cytology of complex thyroid nodules.
OBJECTIVE: To evaluate whether a preliminary aspiration (ASP) of the cystic component and/or using spinal needles in complex thyroid nodules (CTN) could improve the adequacy of cytological sampling.
METHODS: Between January 2004 and December 2006, 386 consecutive patients with CTN were enrolled in this prospective investigation. Ultrasound (US) fine needle aspiration cytology (FNAC) of the solid component of the nodule (one nodule per patient) was performed using two different 25 gauge needles, with (Yale Spinal, YS) or without (Neolus, NS) a stylet, in alternate sequence on consecutive patients. In addition, a subgroup of patients presenting larger cystic component (approximately 50%) was submitted to total aspiration of the cystic component (ASP+) or not submitted (ASP-) before US-FNAC, in alternate sequence within each needle type group. All the samplings were performed by a single endocrinologist.
RESULTS: Adequate specimens were observed in 163 (84.5%) and 183 (94.8%) nodules investigated by NS and YS respectively. Sampling with the stylet needle was associated with an overall significant reduction of non-diagnostic specimens (15.5% vs 5.2% by NS and YS respectively, P < 0.001). The favourable result obtained with YS was independent from preliminary aspiration of the cystic component (ASP+: 14.8% vs 5.7% by NS and YS; ASP-: 16.2% vs 4.8%, not significant). A logistic regression analysis, taking into account nodule size and presence of intranodal vascularity at eco-colour evaluation of the solid component, confirmed that needle type was the only significant predictor of successful sampling (odds ratio 3.6 (95% confidence interval 1.7-7.6), P < 0.001).
CONCLUSIONS: Our data show that adopting stylet needles to perform FNAC in CTN may significantly improve the percentage of adequate sampling. On the other hand, preliminary aspiration of CTN with large cystic component does not add any advantage
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