305 research outputs found

    Flower roundabouts and double-lane roundabouts: a comparative performance analysis

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    AbstractIn the paper, a choice criterion between flower roundabouts and double-lane roundabouts is proposed, focusing on operational benefits that can derive from one scheme over the other, and outlining a general framework for benefit-cost analysis. In order to assess operational benefits of innovative roundabouts over modern roundabouts, a comparative analysis was made. Capacity was estimated using gap-acceptance models. In detail, assuming the dichotomic shifted negative exponential distribution to model headways in circulating streams, the Hagring formula was adjusted to obtain entry capacity estimations at roundabout approaches where entering vehicles face one or two conflicting flows. Based on the control delay, the suitability domains and indifference areas were constructed. Thus, a sensitivity analysis to changes in traffic demand for operational benefits of flower roundabouts over double-lane roundabouts was carried out and discussed. At last, evidence for new installations and conversion of existing roundabouts can be found

    Fronto-Orbito-zygomatic approach: a technical modification.

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    The fronto-orbito zygomatic approach is part of the surgical armamentarium of modern skull base surgery. As described in the literature, it requires costly technological tools such as powerful drills and saws, to be performed. In the present communication we describe a technical modification that allows the zygoma to be elevated "en bloc" together with the fronto-orbital bone flap by means of appropriate use of the Gigli's saw. Using this technique, adequate replacement of the craniotomy flap requires only two silk sutures. This technical modification, which was already successfully used in over 20 cases, would also allow this useful approach to be performed in those neurosurgical environments where modern costly technology for cranial base surgery is not available

    Evolución de los hidrocarburos lineales saturados en el aceite de la pulpa de aguacate (Persea americana, Mill.) a diferentes estados de maduración.

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    The n-alkane composition of Avocado pulp oil (cv. Hass) was investigated during fruit ripening. Three samples of fruit were harvested on March 3, 2003, March 18, 2003 and April 2, 2003. Glass gravity column chromatography was employed to separate n-alkanes from other minor components contained in the unsaponifiable fraction. Gas chromatography was used to analyze the eluate. Fourteen compounds were detected ranging from n -C21 to n -C34; mainly n -C24, followed by n -C25 and then by n -C23. Quantities of n -C21, n -C22, n -C23, n -C27 and n -C28 progressively increased during ripening, whereas n -C24, n -C25, n -C26, n -C29, n -C30 and n -C34 decreased from the first harvest date to the third harvest date. While odd-numbered carbon n-alkanes increased (52.38 %, 52.85 % and 53.06 % for the three samples respectively), even-numbered carbon n-alkanes decreased as the fruit ripened (47.62 %, 47.15 % and 46.94 %). The total n-alkane content decreased during ripening, from 25.20 mg/Kg (first harvest date) to 16.77 mg/Kg (third harvest date). In order to minimize.Se ha analizado la composición en hidrocarburos lineales saturados del aceite de la pulpa de aguacate (variedad Hass). Tres muestras fueron recolectadas: el 3 de marzo 2003, el 18 de marzo 2003 y el 2 de abril 2003. La separación de los hidrocarburos lineales saturados se realizó mediante fraccionamiento del insaponificable por cromatografía gravimétrica de adsorción en columna y la determinación de los mismos hidrocarburos por cromatografía gaseosa. 14 compuestos fueron detectados del n- C21 al n- C34. El n- C24 fue el mayoritario, seguido del n- C25 y el n- C23. El porcentaje de n- C21, n- C22, n- C23, n- C27 y n- C28, aumentó durante la maduración, mientras que el porcentaje de n- C24, n- C25, n- C26, n- C29, n- C30 y C34 disminuyó desde el 3 de marzo 2003 hasta el 2 de abril 2003. Los hidrocarburos lineales saturados con número impar de átomos de carbono aumentaron (52.38 %, 52.85 % y 53.06 % por las tres muestras respectivamente) con la maduración. Por el contrario, hidrocarburos lineales saturados con número par de carbono disminuyeron (47.62 %, 47.15 % y 46.94 %). El contenido total en hidrocarburos lineales saturados disminuyó durante la maduración desde 25.20 mg/kg (3 de marzo 2003) hasta 16.77 mg/kg (2 de abril 2003). Para reducir el contenido total en hidrocarburos lineales saturados en el aceite de aguacate (variedad Hass) es necesario retardar la cosecha del fruto

    Efectos de la variedad y año de cosecha sobre la composición de alcoholes grasos de aceites de oliva del Suroeste de Calabria (Italia)

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    The fatty alcohol (FAL) composition of olive oils produced in Southwest Calabria (Southern Italy) was analyzed over three harvest years 2005–2006–2007. Three autochthonous cultivars: Cassanese, Ottobratica, Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine were considered. Hexacosanol was always the main FAL occurring in the olive oil. The autochthonous cultivars were among those with the highest total FAL contents. Nevertheless, both autochthonous and allochthonous cultivars produced olive oil within the limit indicated by EU and IOC regulations. Cultivar affected the FAL content highly significantly or very highly significantly, whereas in a large part of the cases the harvest year did not influence the FAL content. Cultivar x harvest year influenced highly significantly or very highly significantly only C22-OH, C23-OH, C24-OH, C25-OH, odd chain FALs and the ratio even chain/odd chain FALs.Se ha analizado, durante tres cosechas 2005–2006–2007, la composición de alcoholes grasos (FAL) de aceites de oliva producidos en el suroeste de Calabria (sur de Italia). Se consideraron tres cultivares autóctonos: Cassanese, Ottobratica y Sinopolese y siete alóctonas: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino y Picholine. Hexacosanol fue siempre el principal FAL en los aceites de oliva. Los cultivares autóctonos se encuentran entre los de mayor contenido total de FAL. No obstante, ambos cultivares, autóctonos y alóctonos producen aceites de oliva dentro de los límites de los reglamentos de la UE y del COI. Los cultivares afectan de manera altamente significativa o muy significativa al contenido de FAL, mientras que el año de cosecha no influyó en el contenido de FAL. Cultivar x año de cosecha influye de manera altamente significativa o muy significativa sobre C22-OH, C23-OH, C24-OH, C25-OH, al total de alcoholes grasos de cadena impar y a la relación: FALs cadena par/FALcadena impar

    Lymph node fine needle cytology, Epstein Barr virus infection and Hodgkin Lymphoma

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    Epstein-Barr virus (EBV) is a double-strand DNA virus of the herpes family; it is one of the most common human viruses and it is associated with a wide spectrum of benign and malignant conditions. EBV is related to the development of several neoplasms, globally 1% of tumours, including lymphoproliferative, epithelial and mesenchymal neoplasm. Lymphoproliferative disorders include Hodgkin lymphoma (HL) and B and T cell non-Hodgkin lymphoma. HL is one of the most common lymphoma in the developed world, affecting both young people and adults. HL pathogenesis is complex and includes various and partially unknown mechanisms. EBV has been detected in some HL neoplastic cells and expresses genes with a potential oncogenic function, therefore many studies suggest that viral infections have a causative role in neoplastic transformation. Fine Needle Cytology (FNC) is extensively used in the first diagnosis of any lymph-nodal enlargement, including reactive lymphadeno - pathies and lymphoproliferative processes; therefore cytopathologists are likely to encounter EBVassociated malignancies in cytology samples, mainly HL, which is one of the most common lymphoma. This study focuses on the cytological features and ancillary studies required to diagnose EBV-related HL

    Immunohistochemical localization and functional characterization of somatostatin receptor subtypes in a corticotropin releasing hormone-secreting adrenal phaeochromocytoma: review of the literature and report of a case

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    Somastostatin receptors are frequently expressed in phaeochromocytoma but data on somatostatin receptor subtyping are scanty and the functional response to the somatostatin analogue octretide is still debated.We report an unusual case of pheochromocytoma, causing ectopic Cushing’s syndrome due to CRH production by the tumour cells, in a 50-yr-old woman. Abdominal computed tomography revealed an inhomogeneous, 9-cm mass in the right adrenal gland, and [111In-DTPA0] octreotide scintigraphy showed an abnormal uptake of the radiotracer in the right perirenal region, corresponding to the adrenal mass. The patient underwent laparoscopic surgery and formalin-fixed and paraffin-embedded samples were studied. The tumour was extensively characterized by immunohistochemistry and somatostatin receptor (SSTRs) subtypes expression was analyzed. Histological and immunohistochemical examination of the surgical specimens displayed a typical pheochromocytoma, which was found to be immunoreative to S-100, chromogranin A and neurofilaments. Immunostaining for SSTR subtypes showed a positive reaction for SSTR1, SSTR2A, SSTR2B, antisera on tumour cells. The intense and diffuse immunostaining for corticotropin releasing hormone (CRH) antiserum indicated that Cushing’s disease was dependent on CRH overproduction by the pheochromocytoma, in which no immunostaining for adrenocorticotropic hormone was found. Our report confirms the heterogeneity of the pattern of SSTR expression in pheochromocytomas, and provide further evidence for functional SSTR subtype SSTR2a in a subgroup of pheochromocytomas, suggesting that these tumours may represent potential target for octreotide treatment

    The burden of Candida species colonization in NICU patients: a colonization surveillance study

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    Fungal infections are an important cause of morbidity and mortality in neonatal intensive care units (NICUs). The identification of specific risk factors supports prevention of candidemia in neonates. Effective prophylactic strategies have recently become available, but the identification and adequate management of high-risk infants is still a priority. Prior colonization is a key risk factor for candidemia. For this reason, surveillance studies to monitor incidence, species distribution, and antifungal susceptibility profiles, are mandatory. Among 520 infants admitted to our NICU between January 2013 and December 2014, 472 (90.77%) were included in the study. Forty-eight out of 472 (10.17%) patients tested positive for Candida spp. (C.), at least on one occasion. All the colonized patients tested positive for the rectal swab, whereas 7 patients also tested positive for the nasal swab. Fifteen out of 472 patients (3.18%) had more than one positive rectal or nasal swab during their NICU stay. Moreover, 9 out of 15 patients tested negative at the first sampling, suggesting they acquired Candida spp. during their stay. Twenty-five of forty-eight (52.1%) colonized patients carried C.albicans and 15/48 (31.25%) C.parapsilosis. We identified as risk factors for Candida spp. colonization: antibiotic therapy, parenteral nutrition, the use of a central venous catheter, and nasogastric tube. Our experience suggests that effective microbiological surveillance can allow for implementing proper, effective and timely control measures in a highrisk setting

    Actinic keratosis associated with squamous and basal cell carcinomas: an evaluation of neoplastic progression by a standardized AgNOR analysis.

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    In an attempt to investigate the neoplastic progression in different stages of actinic keratosis (AK), a standardized AgNOR analysis was performed in 94 cases of AK, 35 of which were associated with squamous cell carcinoma (SCC) or basal cell carcinoma (BCC), and in 31 cases of SCC and 22 cases of BCC. The cases were subdivided into low- and high- AgNOR-expressing (AgNOR status) AK by using the mean area of AgNORs per cell (NORA) value (3.996 ?m2) as the cut-off. In AK samples, a progressive increase of the mean NORA value from Stage I to Stage IV was encountered. In addition, a significantly higher mean NORA value was found in the AK cases associated with SCC, in comparison to those without SCC; by contrast, no significant differences in the mean NORA value were noted between AK cases with or without BCC. A highly significant association between a high AgNOR quantity and the coexistence of SCC was encountered in AK; no association was appreciable between the AgNOR quantity and the co-occurrence of BCC. Moreover, when the co-existence of SCC in AK was considered as the reference point, the AK cases associated with SCC mostly (95.5%) presented a high AgNOR quantity (high sensitivity), but only 57.6% of cases without SCC displayed a low AgNOR quantity (low specificity). Additionally, our data document that the standardised AgNOR analysis represents a strong negative predictor for the association between SCC and AK. Indeed, a low AgNOR quantity mostly is associated with AK cases without SCC

    Bacterial oxidases of the cytochrome bd family : redox enzymes of unique structure, function, and utility as drug targets

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    Significance: Cytochrome bd is a ubiquinol:oxygen oxidoreductase of many prokaryotic respiratory chains with a unique structure and functional characteristics. Its primary role is to couple the reduction of molecular oxygen, even at submicromolar concentrations, to water with the generation of a proton motive force used for adenosine triphosphate production. Cytochrome bd is found in many bacterial pathogens and, surprisingly, in bacteria formally denoted as anaerobes. It endows bacteria with resistance to various stressors and is a potential drug target. Recent Advances: We summarize recent advances in the biochemistry, structure, and physiological functions of cytochrome bd in the light of exciting new three-dimensional structures of the oxidase. The newly discovered roles of cytochrome bd in contributing to bacterial protection against hydrogen peroxide, nitric oxide, peroxynitrite, and hydrogen sulfide are assessed. Critical Issues: Fundamental questions remain regarding the precise delineation of electron flow within this multihaem oxidase and how the extraordinarily high affinity for oxygen is accomplished, while endowing bacteria with resistance to other small ligands. Future Directions: It is clear that cytochrome bd is unique in its ability to confer resistance to toxic small molecules, a property that is significant for understanding the propensity of pathogens to possess this oxidase. Since cytochrome bd is a uniquely bacterial enzyme, future research should focus on harnessing fundamental knowledge of its structure and function to the development of novel and effective antibacterial agents
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