470 research outputs found
Entire subsolutions of fully nonlinear degenerate elliptic equations
We prove existence and non existence results for fully nonlinear degenerate
elliptic inequalities, by showing that the classical Keller--Osserman condition
on the zero order term is a necessary and sufficient condition for the
existence of entire sub solutions
La Patologia del muflone in Sardegna
In questa sede verranno riferiti i risultati di indagini condotte su mufloni provenienti da diverse zone dell’Isola o allevati a scopo di reintroduzione presso il Centro faunistico dell’Ufficio Regionale della Fauna (U.R.F.), deceduti per cause diverse ed esaminati nel corso degli anni 1990-93. Si tratta di una mole estremamente ampia di dati che seppure nei limiti delle metodiche applicate (es. clinici e anatomoistopatologici) ha consentito di fare una prima ricognizione sulla patologia cui il muflone sardo può andare incontro in diverse situazioni
Apparato genitale femminile dell'ovino sardo: alterazioni anatomo patologiche e ipofecondità
A survey was carried out on ovine female genital tracts collected from slaughtered Sardinian sheep. Of 1177 apparata, 293 showed different lesions in various sites, 76 of which were considered as a cause of sterility or ipofecundity. The AA. report the frequency of trombosis and fribrous calcification in ovarian and uterine arteries
Peripheral nerve sheath myxoma. Clinicopathological and immunohistochemical study of a morphologically distinctive myxoid peripheral nerve sheath tumor in the forelimb of a cat
Peripheral nerve sheath tumors (PNST) are a class of nervous system tumors which arise in both schwann
cells and perineural fibroblasts. Benign and malignant PNSTs are reported to occur in all domestic animals.
In cats they represent 3% of all cutaneous and subcutaneous neoplasms. Only in dogs mixoid PNST has
been observed generally localized in the fingers. In humans, PNSTs are rare neoplasms, and nerve sheath
myxomas are a distinct neoplasia most commonly found in limb extremities
Evaluation of anatomical and histopathological changes in target organs of cattle slaughtered in Sardinia as a result of the illegal use of growth hormones. Preliminary results
Within the bovine specie, illegal use of anabolic agents can be grouped into four categories: beta-agonists,
thyrostatics, glucocorticoids, sexual steroids.
These substances, further their anabolic effect, cause morphological changes in target organs which can be
evidenced by anatomical and histopathological testing. Such investigations are extremely important to
screen and to detect in advance groups of animals in risk-breeding
Semblanza del Dr. Víctor Ml. Sánchez Corrales
La actividad académica del Dr. Víctor Ml. Sánchez Corrales abarcó todas las áreas en las que un universitario está llamado a desenvolverse. Destacado docente e investigador en los tres ejes del quehacer universitario (Docencia, Investigación y Acción Social), también se desempeñó de manera sobresaliente en numerosos cargos en la administración universitaria, de los que cabe resaltar su labor como miembro y Director del Consejo Universitario de la Universidad de Costa Rica, donde su visión de universidad dejó su impronta para las generaciones presentes y futuras
Combustion of lignin-rich residues with coal in a pilot-scale bubbling fluidized bed reactor
The deployment and the exploitation of bioethanol as automotive fuel became more and more relevant to reduce the emissions of greenhouse gases and to limit the dependence on countries supplying fossil fuels. However, the production of second-generation bioethanol, i.e. using lignocellulosic biomass or scraps of agricultural crops as feedstock, generates a waste stream consisting of lignin-rich residues whose fate has to be found (1-2). This work aims at investigating the combustion of lignin-rich residues (in the following simply called lignin), coming from a second-generation bioethanol production plant, with coal in a pilot-scale bubbling fluidized bed combustor (FBC). The pilot-scale 200kWth FBC schematically shown in Fig. 1 basically consist of a AISI 310 stainless steel fluidization circular column (370 mm ID for 5.05 m and 700 mm ID for 1.85m in the upper part of freeboard), a continuous over-bed feeding system, two cyclones for flue gas de-dusting, a propane premixed burner for the start-up and different heat removal devices located along the fluidization column. On-line gas analyzers (ABB AO2020) measured flue gas composition sampled at the exhaust. Fuels were the lignin-rich residue, a bituminous coal and wood chips. Silica sand (0.8-1.2mm) was used as bed material. An experimental campaign was carried out to study gaseous and particulate emissions and thermal regimes during the co-combustion of different mixtures of coal-lignin varying the percentage of lignin fed with coal, the bed temperature, the excess air and the fluidization velocity. Figure 2 reports the main results in terms of normalized emissions of NO, SO2, particulate and carbon in particulate as a function of the O2 concentration measured at the exhaust obtained during the steady state operation of the pilot-scale FBC. A large part of the investigated experimental conditions regarded the operation using a mixture lignin-coal at 30%w in lignin. Experiments with coal, with a mixture at 40%w in lignin and with a mixture coal-wood chips at 20%w in wood chips were carried out for comparison. The analysis of the experimental results mainly highlights that: 1) the gaseous emissions do not significantly change with respect to coal or to reference biomass-coal mixture at least until the mixture content of lignin is 30-40%w; 2) the particulate emissions increase with the percentage of residues content, but, at the same, the carbon content is significantly reduced. Bottom bed particles were analyzed at the end of each experiments highlighting the absence of agglomerates but a significant enrichment of metals like Fe, Mg, Na, Ca and K coming from lignin ash when the FBC was operated for long time and at high temperature.
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Immunohistochemistry and biomolecular investigation for the evidence of JSRV-like retrovirus in human bronchiolo-alveolar carcinomas
The bronchioloalveolar adenocarcinoma was described in several species (human, bovine, ovine and domestic
carnivores). Ovine pulmonary adenocarcinoma (OPA) or pulmonary adenomatosis is a contagious carcinoma of sheep
caused by an exogenous type D retrovirus denominated also jaagsiekte sheep retrovirus (JSRV). JSRV is responsible of
the neoplastic transformation of type II pneumocytes and Clara cells. The human bronchioloalveolar adenocarcinoma
(BAC) have histo-morphological features much similar to OPA. We report the study about ten BAC cases and one
negative human control (lung). DNA extraction, PCR, sequencing of amplified product, immunohistochemistry and insitu
hybridization were performed on all paraffin-embedded samples. Our results demonstrated the presence of JSRVlike
sequences in all cases of human bronchiolo-alveolar carcinoma
Osservazioni istochimiche e immunoistochimiche sull'ipofisi anteriore di un cane affetto da malattia di Cushing
Gli adenomi del lobo anteriore dell'ipofisi sono
neoplasie benigne piuttosto frequenti. Essi
mostrano aspetto circoscritto e accrescimento non
invasivo nei confronti dei tessuti circostanti. Il
tumore a cellule secernenti ACTH, che colpisce le
cellule cromofobe della pars anteriore dell'ipofisi,
è uno di questi e viene associato alla sindrome di
Cushing, causando evidente ipercortisolemia per
stimolazione della corteccia surrenale. Un cane
meticcio, femmina, di 7 anni, in terapia per
sospetta Sindrome di Cushing e pervenuto a
morte, è stato sottoposto ad accurato esame
necroscopico, durante il quale si procedeva tra
l'altro a prelevare ghiandole surrenali, polmone,
fegato, cute, muscoli e intera ghiandola pituitaria.
Su detti organi veniva eseguito l'esame
istopatologico per la ricerca delle lesioni tipiche
determinate dalla sindrome. Sulla ghiandola
pituitaria, aumentata notevolmente di volume,
venivano eseguite indagini istopatologiche
specifiche, mediante colorazione OFG, per
differenziare gli istotipi costituenti la pars
anteriore. Tale colorazione ha consentito di
riscontrare e identificare tra le cellule pituitarie gli
elementi acidofili, basofili e cromofobi; queste
ultime cellule, aumentate di numero, erano
d'aspetto omogeneo e formavano un nucleo
compatto e con scarso stroma al centro della
ghiandola. La caratterizzazione cromatica e la
differenziazione dai restanti istotipi ha reso
possibile identificare la neoplasia come adenoma
ipofisario di tipo "diffuso", caratterizzato per
l'appunto da cellule disposte a strati, con scarso
stroma e debole vascolarizzazione. Per verificare
l'ormonoattività delle cellule neoplastiche si è
proceduto all'esame immunoistochimico per la
ricerca dell'ACTH. Il risultato di tale indagine ha
dato esito positivo, confermando l'intensa attività secernente delle cellule oggetto di studio
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