Search results for " cavi"
showing 10 items of 537 documents
Determinazione in continuo di CO2, CH4 e H2Ov in ambiente atmosferico attraverso tecnica ad assorbimento laser (UGGA)
2015
Molti dei composti chimici presenti nell’atmosfera terrestre prendono il nome di “gas serra”. Queste specie gassose consentono alla radiazione solare di entrare liberamente nell’atmosfera e di trattenere parte della radiazione solare riflessa dalla superficie terrestre come energia termica. Nel corso del tempo si instaura un complesso equilibrio termico tra la quantità di energia inviata dal sole e quella irradiata dalla superficie. L’alterazione di questo equilibrio, con l’aumento di uno o più gas serra in atmosfera, porta a degli squilibri termici e un conseguente innalzamento delle temperature. Questo fenomeno è definito come “effetto serra”. I principali gas serra in natura che prendono…
Fine Determination of the Molt Cycle Stages in Orchestia cavimana Heller (Crustacea: Amphipoda)
1986
ABSTRACT The successive stages of the molt cycle of the terrestrial crustacean amphipod Orchestia cavimana are finely described and illustrated in order to give precise reference marks for experimental, physiological, and biochemical studies. The method of determination, very rapid and easy, is based upon the observation of the morphogenesis of the dactylopodite and the propodite from the third pereiopod. The events of the early morphogenesis of the claw from the dactylopodite divide the intermolt period C into four stages. The formation of spines and the secretion of the epicuticle and then the procuticle at the level of the propodite divide the premolt period into seven stages. The entire…
Variations in haemolymph ionized calcium concentrations in the crustacean Orchestia cavimana during a moult cycle
1993
Abstract Measurements of ionized calcium concentration in the haemolymph of the semi-terrestrial crustacean Orchestia cavimana were taken during the 14 successive moulting stages by ion-selective electrode direct potentiometry on pooled samples. Ionized calcium showed major variations associated with the moult cycle. Titres were low and relatively stable in intermoult and early premoult, then progressively increased during mid and late premoult to reach maximal values just at exuviation, and rapidly fell down during the postmoult. The variations of the ionized fraction showed a close correlation with those of the calcaemia (= total fraction), suggesting the presence of efficient haemolympha…
Analysis of the multipactor effect by means of the 3D BI-RME method
2017
Multipactor effect is a well-known phenomenon of RF breakdown in satellite pay-loads which degrades components, generates undesirable harmonics, contributes to power dissipation and increases noise in communications. Traditionally, multipactor has been investigated with the aim of obtaining the so-called multipactor threshold voltage, or to present different multipaction detection methods. Little effort has been devoted, in contrast, to study the problem from a full-wave point of view, thus allowing for the analysis of more complex structures. The main goal of this work is to analyze the interaction between a multipactor current and a realistic microwave cavity by means of a rigorous and ac…
Investigating the possible impact of peritoneal tumor exposure amongst women with early stage cervical cancer treated with minimally invasive approac…
2021
Abstract Introduction Recent findings show a detrimental impact of the minimally invasive approach on patients with early stage cervical cancer (ECC). Reasons beyond these results are unclear. The aim of the present article is to investigate the possible role of peritoneal contamination during intracorporeal colpotomy. Methods patients with early stage cervical cancer were divided into 2 groups: no intraperitoneal exposure (N-IPE) intraperitoneal exposure (IPE) during minimally invasive surgery. Patients of the 2 groups were propensity-matched according to the major risk factors. Results 226 cases of the IPE group had a significant worst prognosis than the 142 cases of the N-IPE group (4.5-…
Relationship between rhinitis duration and worsening of nasal function
2008
BackgroundWhile it is well known that asthma is characterized by airway remodeling, few studies instead have investigated this issue in patients with allergic rhinitis (AR).ObjectiveThe aim of the study was to evaluate nasal function, ie, nasal airflow, in a cohort of patients with persistent AR (PER).MethodsOne hundred patients, 50 with short-term and 50 with long-term PER, were prospectively and consecutively evaluated, clinically evaluated by visit, skin prick test, and rhinomanometry.ResultsNasal airflow values were significantly lower (median flow: 348 mL/sec) in patients with long-term rhinitis (median duration nine years) as compared to patients with short-term (median duration one y…
Radiofrequency volumetric tissue reduction (RFVTR) of inferior turbinates: a new method in the treatment of chronic nasal obstruction.
2001
Twenty-two Caucasians (16 male and 6 female) with chronic bilateral nasal obstruction due to hypertrophic inferior turbinates were followed up over a three-month period. They were assessed by clinical examination, as active anterior rhinometry, and acoustic rhinometry before and after topical decongestion, preoperatively and three months after surgery. All patients were treated by application of radiofrequency-volumetric-tissue reduction (RFVTR, or somnoplasty) to both inferior turbinates. Initial postoperative edematous response disappeared during the first week after RFVTR. Three months postoperatively 20 of 22 patients (91%) reported subjective improvement of nasal patency. The average …
Dynamische Bildgebung der Nasenhaupthöhle und der Nasennebenhöhlen im MR mittels polarisiertem 3Helium
2001
sinuses with polarized 3 helium MRI. Purpose: Reduced or blocked ventilation of the paranasal sinuses is probably the most important factor in the development of sinusitis. Recently, the use of optically polarized noble gas isotopes has attracted increasing interest for use in a variety of promising MR applications. The aim of this study was to test the feasibility of imaging and visualization ventilation of the nasal cavity and paranasal sinus in MR by inhalation of hyperpolarized 3 helium. The goal was to evaluate ventilation defects of the paranasal sinuses. Volunteers and Methods: Three volunteers were enrolled in the study. 3 Helium was polarized to 40-50% by direct optical pumping. 30…
Acoustic rhinometry in pre-school children.
1993
Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34 +/- 0.06 cm2, 0.35 +/- 0.08 cm2 and 1.37 +/- 0.48 cm2 respectively. The average minimal cross-sectional area was 0.29 +/- 0.06 cm2. The minimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal turbinates in 21 of the 35 children. As would be expected, the cross-sectional areas at different sites of the nasal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm2 per …
Invagination of the Sphenoid Sinus Mucosa after Endoscopic Endonasal Transsphenoidal Approach and Its Significance
2016
Objective To describe the clinical features of invagination of the sphenoid sinus mucosa (ISM) and compare them with other similar cases using a visual analog scale (VAS) to assess the various nasal symptoms and to discuss its clinical significance and means of prevention. Study design Retrospective chart review at a tertiary referral center. Methods Between 2010 and 2015, 8 patients who had undergone EETSA surgery displayed postoperative ISM. The comparison group consisted of 147 patients who underwent the same surgical procedures and were diagnosed with the same diseases. Pre- or postoperative paranasal sinus computed tomography (PNS CT) and VAS were performed and subsequently analyzed. R…