236 research outputs found
Voriconazole treatment of Candida tropicalis meningitis: persistence of (1,3)-b-D-glucan in the cerebrospinal fluid is a marker of clinical and microbiological failure
Introduction: Infections are still the most common complications of cerebral shunt procedures. Even though fungal etiologies are considered to be rare, they are associated with significant morbidity and mortality. Due to their uncommonness, diagnostic procedures and optimal therapy are poorly defined. We report a case of Candida tropicalis infection of ventriculo-peritoneal cerebrospinal fluid (CSF) shunt in a 49-year-old immune competent male treated with voriconazole (VOR). Methods: Microbiological and CSF markers (1,3-b-D-glucan-BDG) of fungal infection, biofilm production capacity, sensitivity of serial isolates of the pathogen, and the concentration of the antifungal drug have been monitored and related to the clinical course of this infection. Results: Despite appropriate treatment with VOR, in terms of adequate achieved CSF drug concentrations and initial effective therapeutic response, loss of VOR susceptibility of the C tropicalis and treatment failure were observed. Conclusion: Biofilm production of the C. tropicalis isolate might have had a significant role in treatment failure. Of interest, clinical and microbiological unfavorable outcome was anticipated by persistence of BDG in CSF. Rising titers of this marker were associated with relapse of fungal infection
Computational Modeling of Magnesium Hydroxide Precipitation and Kinetics Parameters Identification
Magnesium is a critical raw material and its recovery as Mg(OH)2 from saltwork brines can be realized via precipitation. The effective design, optimization, and scale-up of such a process require the development of a computational model accounting for the effect of fluid dynamics, homogeneous and heterogeneous nucleation, molecular growth, and aggregation. The unknown kinetics parameters are inferred and validated in this work by using experimental data produced with a T2mm-mixer and a T3mm-mixer, guaranteeing fast and efficient mixing. The flow field in the T-mixers is fully characterized by using the k-ε turbulence model implemented in the computational fluid dynamics (CFD) code OpenFOAM. The model is based on a simplified plug flow reactor model, instructed by detailed CFD simulations. It incorporates Bromley's activity coefficient correction and a micro-mixing model for the calculation of the supersaturation ratio. The population balance equation is solved by exploiting the quadrature method of moments, and mass balances are used for updating the reactive ions concentrations, accounting for the precipitated solid. To avoid unphysical results, global constrained optimization is used for kinetics parameters identification, exploiting experimentally measured particle size distribution (PSD). The inferred kinetics set is validated by comparing PSDs at different operative conditions both in the T2mm-mixer and the T3mm-mixer. The developed computational model, including the kinetics parameters estimated for the first time in this work, will be used for the design of a prototype for the industrial precipitation of Mg(OH)2 from saltwork brines in an industrial environment
???Pull-through??? Resection for Total and Subtotal Glossectomy Involving the Posterior Third of Tongue
The lower lip-splitting incision associated with different types of mandibulotomy, in order to obtain wide access to total or subtotal glossectomy, is described. In those cases, high rates of functional and aesthetic deficit and postoperative morbidity (more in cases of patients in which adjuvant radiotherapy has been performed) are described. We present our experience in the treatment of patients undergoing total or subtotal glossectomy and contemporary reconstruction with flaps, and without lip-splitting incision and mandibulotomy. Materials and Methods: Data about patients affected by malignant tumors requiring total or subtotal (posterior third of the tongue) resection that were treated at our department from January 2004 to December 2014 were retrospectively reviewed. Data evaluated included: T and N stage, resection margins, operation time, and post-operative complications, such as fistula and flap necrosis. Results: 41 patients were identified. In two cases microscopic infiltration of one margin was found (R1); in one case a close margin was identified. In 26 cases reconstruction was performed using free flaps, and in the remaining cases a pectoralis major flap was used. In three cases postoperative complications were observed. Discussion and conclusions: In theory, lip-splitting and mandible discontinuity could allow for increased access and tumor visualization, and could facilitate flap positioning. Nevertheless, in our experience, it is not necessary in the case of total or subtotal glossectomy
Variations in the amount of water ice on Ceres' surface suggest a seasonal water cycle.
The dwarf planet Ceres is known to host a considerable amount of water in its interior, and areas of water ice were detected by the Dawn spacecraft on its surface. Moreover, sporadic water and hydroxyl emissions have been observed from space telescopes. We report the detection of water ice in a mid-latitude crater and its unexpected variation with time. The Dawn spectrometer data show a change of water ice signatures over a period of 6 months, which is well modeled as ~2-km2 increase of water ice. The observed increase, coupled with Ceres' orbital parameters, points to an ongoing process that seems correlated with solar flux. The reported variation on Ceres' surface indicates that this body is chemically and physically active at the present time
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