3,192 research outputs found

    Current progress on engineering microbial strains and consortia for production of cellulosic butanol through consolidated bioprocessing

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    In the last decades, fermentative production of n-butanol has regained substantial interest mainly owing to its use as drop-in-fuel. The use of lignocellulose as an alternative to traditional acetone-butanol-ethanol fermentation feedstocks (starchy biomass and molasses) can significantly increase the economic competitiveness of biobutanol over production from non-renewable sources (petroleum). However, the low cost of lignocellulose is offset by its high recalcitrance to biodegradation which generally requires chemical-physical pre-treatment and multiple bioreactor-based processes. The development of consolidated processing (i.e., single-pot fermentation) can dramatically reduce lignocellulose fermentation costs and promote its industrial application. Here, strategies for developing microbial strains and consortia that feature both efficient (hemi)cellulose depolymerization and butanol production will be depicted, that is, rational metabolic engineering of native (hemi)cellulolytic or native butanol-producing or other suitable microorganisms; protoplast fusion of (hemi)cellulolytic and butanol-producing strains; and co-culture of (hemi)cellulolytic and butanol-producing microbes. Irrespective of the fermentation feedstock, biobutanol production is inherently limited by the severe toxicity of this solvent that challenges process economic viability. Hence, an overview of strategies for developing butanol hypertolerant strains will be provided

    Importance of CBCT in the management plan of upper canine with internal resorption

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    Abstract Aim Internal root resorption is a particular medical condition which requires the clinician to a treatment as early as possible to avoid complications such as excessive loss of mineralized tissues and periodontal communications. Methodology This article describes the diagnosis and treatment of a case of internal resorption of an upper canine in a patient of 21 years. The presence of pain and swelling periodontal gum showed an interest, a sign of the presence of a perforation. Result and conclusions Accurate diagnosis associated with the three-dimensional evaluation of the internal fault (CBCT examination) have allowed a conservative treatment who has allowed the recovery of the tooth

    Ludwig's angina: a case report with a 5-year follow-up

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    Aim: Ludwig's angina is a rare aggressive infection, often of dental origin, characterized by a rapid spread of cellulitis in the submandibular and sublingual spaces. Ludwig's angina is potentially fatal, if it obstructs the airways and if it is not treated with appropriate antibiotic therapy. Summary: The case report describes the diagnosis and the management of a Ludwig's angina caused by an endodontic infection in a 16 years-old female patient. The infection has been caused by a decay of the second lower right molar. After hospitalization and systemic antibiotic therapy, in accordance with the patient and the parents endodontic and restorative treatments of the tooth were performed. After 3 and 5 years, the radiological examination revealed no periapical lesions around right lower second molar and the presence of lamina dura. Key learning points: This aggressive infection may often be undervalued and this may cause dangerous consequences to the patient's life. The infection can be prevented by periodic dental care and interventions, which can avoid odontogenic infections. In the case of Ludwig's angina, early diagnosis is fundamental to save the patient's life. After the initial antibiotic therapy and once the life of the patient is no longer at risk, an appropriate endodontic therapy can be considered a valid therapy for this disease. Riassunto: Obiettivi: L'angina di Ludwig è un'infezione aggressiva, spesso di origine odontogena, caratterizzata da una raccolta cellulitica a rapida evoluzione che coinvolge gli spazi sotto-mandibolare e sotto-linguale. Essa può ostruire le vie respiratorie ed essere potenzialmente fatale se non tempestivamente trattata con cure antibiotiche appropriate. Riassunto: In questo articolo viene descritto un caso di diagnosi e trattamento di un'angina di Ludwig causata da un'infezione odontogena in una ragazza di 16 anni. L'infezione é stata causata da una carie a carico del secondo molare inferiore di destra. Dopo il ricovero ospedaliero ed una terapia antibiotica sistemica parenterale, con il consenso dei genitori abbiamo è stata eseguita una terapia endodontica e la successiva ricostruzione con materiali adesivi dell'elemento dentario in questione. Dopo 3 e 5 anni gli esami radiografici mostrano assenza di lesioni periapicali e la presenza della lamina dura. Punti chiave di apprendimento: Questa infezione aggressiva è spesso sottovalutata e ciò può causare conseguenze gravi per la vita del paziente. Tali infezioni possono essere prevenute con controlli periodici del cavo orale. In caso di angina di Ludwig una diagnosi tempestiva è fondamentale per salvare la vita del paziente. Dopo l'iniziale terapia antibiotica ed aver messo in sicurezza la salute generale del paziente, la terapia endodontica può essere considerata una valida alternativa per questa patologia. Keywords: Ludwig's angina, Endodontic therapy, Endodontic infection, CBCT, Management infection, Parole chiave: Angina di Ludwig, Terapia endodontica, Infezione endodontica, CBCT, Gestione dell'infezion

    Modelling and Design of a Coils Structure for 100 kW Three-Phase Inductive Power Transfer System

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    This paper presents the modeling, the design and verification of a three-phase coil structure for high-power Wireless-Power-Transfer (WPT) in automotive applications. The system, a Three- Polar-Pad (TPP), with complex mechanical geometry, is analytically modeled with an equivalent simplified structure. Thanks to this simplification, a numerical design is performed to minimize cross-coupling effects among different phases of the same side (receiver or transmitter) maximizing the linkage flux receiver-to-transmitter and then the power transferred. The analytical model is then verified in a Finite-Element-Analysis (FEA) environment. A final design, comprehensive of the shielding, is proposed matching the preliminary design constraints. Hence, the preliminary model is verified by testing a prototype using a three-phase Silicon Carbide (SiC) inverter at the transmitter side. The capability of the system is demonstrated by transferring 100 kW with more than 94% DC-to-DC efficiency over a 50 mm air gap in perfectly aligned conditions

    Input Parallel Output Series Structure of Planar Medium Frequency Transformers for 200 kW Power Converter: Model and Parameters Evaluation

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    Nowadays, the demand for high power converters for DC applications, such as renewable sources or ultra-fast chargers for electric vehicles, is constantly growing. Galvanic isolation is mandatory in most of these applications. In this context, the Solid State Transformer (SST) converter plays a fundamental role. The adoption of the Medium Frequency Transformers (MFT) guarantees galvanic isolation in addition to high performance in reduced size. In the present paper, a multi MFT structure is proposed as a solution to improve the power density and the modularity of the system. Starting from 20 kW planar transformer model, experimentally validated, a multi- transformer structure is analyzed. After an analytical treatment of the Input Parallel Output Series (IPOS) structure, an equivalent electrical model of a 200 kW IPOS (made by 10 MFTs) is introduced. The model is validated by experimental measurements and tests

    Assessment of cerebral microbleeds by susceptibility-weighted imaging at 3T in patients with end-stage organ failure

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    Purpose: Cerebral microbleeds (CMBs) are small rounded lesions representing cerebral hemosiderin deposits surrounded by macrophages that results from previous microhemorrhages. The aim of this study was to review the distribution of cerebral microbleeds in patients with end-stage organ failure and their association with specific end-stage organ failure risk factors. Materials and methods: Between August 2015 and June 2017, we evaluated 15 patients, 9 males, and 6 females, (mean age 65.5 years). Patients population was subdivided into three groups according to the organ failure: (a) chronic kidney failure (n = 8), (b) restrictive cardiomyopathy undergoing heart transplantation (n = 1), and (c) end-stage liver failure undergoing liver transplantation (n = 6). The MR exams were performed on a 3T MR unit and the SWI sequence was used for the detection of CMBs. CMBs were subdivided in supratentorial lobar distributed, supratentorial non-lobar distributed, and infratentorial distributed. Results: A total of 91 microbleeds were observed in 15 patients. Fifty-nine CMBs lesions (64.8%) had supratentorial lobar distribution, 17 CMBs lesions (18.8%) had supratentorial non-lobar distribution and the remaining 15 CMBs lesions (16.4%) were infratentorial distributed. An overall predominance of supratentorial multiple lobar localizations was found in all types of end-stage organ failure. The presence of CMBs was significantly correlated with age, hypertension, and specific end-stage organ failure risk factors (p < 0.001). Conclusions: CMBs are mostly founded in supratentorial lobar localization in end-stage organ failure. The improved detection of CMBs with SWI sequences may contribute to a more accurate identification of patients with cerebral risk factors to prevent complications during or after the organ transplantation

    3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

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    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability

    Cloud for eGov: the state of the art

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    Specifically, the paper provides a detailed analysis of the state of the art regarding technological, regulatory and interoperability aspects, devoting particular attention to those projects (and related experience) in the field of cloud and distributed computing. The paper's aim is to evaluate benefits and risks of the applicability of solutions that are already in place for the specified areas of interest. The key factors that determine relevant regulations, with particular emphasis on the European target, have been listed in the paper. Finally, the main Italian projects and the situation in some European countries have also been mentioned

    Fully digital intensity modulated LIDAR

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    AbstractIn several applications, such as collision avoidance, it is necessary to have a system able to rapidly detect the simultaneous presence of different obstacles. In general, these applications do not require high resolution performance, but it is necessary to assure high system reliability also within critical scenarios, as in the case of partially transparent atmosphere or environment in presence of multiple objects (implying multiple echoes having different delay times.) This paper describes the algorithm, the architecture and the implementation of a digital Light Detection and Ranging (LIDAR) system based on a chirped optical carrier. This technique provides some advantages compared to the pulsed approach, primarily the reduction of the peak power of the laser. In the proposed architecture all the algorithms for signal processing are implemented using digital hardware. In this way, some specific advantages are obtained: improved detection performance (larger dynamics, range and resolution), capability of detecting multiple obstacles having different echoes amplitude, reduction of the noise effects, reduction of the costs, size and weight of the resulting equipment. The improvement provided by this fully digital solution is potentially useful in different applications such as: collision avoidance systems, 3D mapping of environments and, in general, remote sensing systems which need wide distance and dynamics
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