Circumcaval ureter with synchronous ipsilateral transitional cell carcinoma of the renal pelvis and the urinary bladder: report of a case and review of the literature

We report a case of concomitant transitional cell carcinoma (TCC) in a circumcaval ureter and invasive bladder cancer. The diagnosis was based on the findings of excretory urography (IVU) and contrast-enhanced computed tomography (CT). IVU showed a typical J-shaped deformity in the dilated right proximal ureteric segment with moderate hydronephrosis and a filling defect in the renal pelvis, while abdominal CT with contrast showed right hydronephrosis with an intrapelvic tumor. The patient underwent radical cystoprostatectomy and nephroureterectomy. No recurrence was detected after 12 months of follow-up.Key Words: Circumcaval, retrocaval, ureter, bladder, transitional cell carcinom

Liposarcoma of the extremities: MR imaging features and their correlation with pathologic data

SummaryObjectiveTo describe the MRI features of liposarcomas of the extremities and correlate them with data from the histologic subtypes.Material and methodsRetrospective study of 20 cases of liposarcoma of the extremities identified on MRI, surgically removed and confirmed at pathology. On MRI examination, T1- and T2-weighted fat-suppressed and non-fat-suppressed images were acquired then gadolinium-enhanced fat-suppressed T1-weighted images were obtained in at least two orthogonal planes.ResultsSixteen female and four male patients aged 12 to 77 years old at presentation, in 16 cases, with a slowly enlarging painless mass (demonstrating no associated local or general inflammatory components), located in the lower extremity (16 cases) and predominantly located in the thigh (13 cases). Pathologic examination revealed three cases of well-differentiated liposarcoma, 12 cases of myxoid liposarcoma one of which with round cells, three cases of pleomorphic liposarcoma, one case of dedifferentiated liposarcoma and one case of mixed-type liposarcoma. MR images mostly showed well-circumscribed tumors (19 cases) . Well-differentiated liposarcomas typically demonstrated a very specific diagnostic appearance as a predominantly adipose mass containing nonlipomatous components seen as thick septa that may show nodularity. Other subtypes of liposarcoma demonstrated a small amount of adipose tissue thus producing a marbled textural pattern on T1-weighted images particularly in myxoid liposarcomas (9 cases), or even nonlipomatous elements in high-grade liposarcomas (in round cell liposarcoma and in two out of three pleomorphic liposarcomas). The myxoid subtype has also a relatively characteristic appearance as a low signal intensity noted on T1-weighted images and a marked high signal intensity on T2. The dedifferentiated liposarcoma has a very specific radiologic appearance as a nonlipomatous component within a predominantly adipose mass, simulating that of well-differentiated liposarcomas.ConclusionMRI of extremity liposarcomas is a highly reliable and sensitive method to characterize liposarcomas. Besides its value in the diagnosis of liposarcoma and locoregional extension control, it allows proper identification of the specific histologic subtypes of liposarcoma.Level of evidenceLevel IV. Rétrospective diagnostic study

Correlation between microstructure and intergranular corrosion behavior of low delta-ferrite content AISI 316L aged in the range 550e700 C

The microstructure and the phase identification of austenitic stainless steel AISI 316L with low δ-ferrite content (δ ≤ 1%) and aged for up to 80 000 h at temperatures ranging from 550 to 700 °C were investigated by using an optical microscope (OM), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Local changes of chromium content, resulting from nucleation and growth of chromium-rich phases during aging, were quantitatively assessed by energy dispersive X-ray spectroscopy (EDX) in the scanning transmission electron microscope (STEM). The intergranular corrosion behavior (IGC) of annealed and aged specimens was evaluated using the double loop electrochemical potentiokinetic reactivation (DL-EPR) and completed by IGC morphologies according to the ASTM A262 practice A standard. The results showed that δ-ferrite decomposed gradually into M23C6 at 550 °C and decomposed totally into intermetallic phases (σ, η, χ, and R) and into secondary austenite (γr) at temperatures equal to or higher than 650 °C. Similarly γ-austenite decomposed into M23C6 carbide at 550 °C and into intermetallic phases such as η and σ in addition to carbide, at higher temperatures. The time-temperature-sensitization diagram (TTS) was established and used to calculate the critical cooling rate (CCR) that prevents IGC sensitization. The analysis of IGC results leads to the conclusion that sensitization-desensitization is still controlled by the characteristics of chromium-depleted area surrounding austenite grain boundary regions. No significant effect of remained δ-ferrite and derived components on the corrosion behavior of AISI 316 L containing 1% of δ-ferrite

Pituitary Adenylate Cyclase Activating Peptide (1-38) and its analog (Acetyl-[Ala15, Ala20] PACAP 38-polyamide) reverse methacholine airway hyperresponsiveness in rats

O objetivo deste estudo foi investigar funcionalmente e estruturalmente efeito broncodilatador do peptídeo ativador da adenilato ciclase pituitária (PACAP1-38) e da acetil-[Ala15, Ala20]PACAP 38-poliamida, potente análogo do PACAP-38, nos ratos desafiados pelo metacolina (MeCh). Ratos Wistar machos foram aleatoriamente divididos em cinco grupos. Grupos 1 e 2, inalando aerossóis de solução salina ou doses crescentes de MeCh (0,5, 1, 2,12, 4,25, 8,5, 17, 34 e 68 mg/L). Os outros grupos recebendo terbutalina (Terb) (250 µg/rato) (10-6M), PACAP-38 (50 µg/rato) (0.1 mM) ou análogo do PACAP-38 (50 µg/rato) associados a MeCh na dose de 4,25 mg/L. A resistência pulmonar total (RL) foi registrada antes e 2 min após a administração de Mech pelo equipamento pneumomultiteste. A administração MeCh induziu aumento significativo e dose dependente (pThe aim of this study was to investigate both functionally and structurally bronchodilator effects of Pituitary adenylate cyclase activating peptide (PACAP38) and acetyl-[Ala15, Ala20] PACAP38-polyamide, a potent PACAP38 analog, in rats challenged by methacholine (MeCh). Male Wistar rats were divided randomly into five groups. Groups 1 and 2 inhaled respectively aerosols of saline or increasing doses of MeCh (0.5, 1, 2.12, 4.25, 8.5, 17, 34 and 68mg/L). The other groups received terbutaline (Terb) (250 µg/rat) (10-6 M), PACAP38 (50 µg/rat) (0.1 mM) or PACAP38 analog (50 µg/rat) associated to MeCh from the dose of 4.25 mg/L. Total lung resistances (RL) were recorded before and 2 min after MeCh administration by pneumomultitest equipment. MeCh administration induced a significant and a dose-dependent increase (

Design and control of a pumping system fed by hybrid Photovoltaic-Wind source without battery storage

International audienc

Effects of surface preparation on pitting resistance, residual stress, and stress corrosion cracking in austenitic stainless steels

Surface finishing treatments such as shot blasting and wire brushing can be beneficial in improving the integrity of machined surfaces of austenitic stainless steels. These operations optimize in-service properties such as resistance to pitting corrosion and stress corrosion cracking (SCC). In this study, ground steel surfaces were subjected to a series of sand blasting and wire brushing treatments. The surfaces were then characterized by their hardness, surface residual stress state, and resistance to stress corrosion and pitting corrosion. Some samples were selected for depth profiling of residual stress. It is found that surface hardening and the generation of near-surface compressive residual stress are the benefits that can be introduced by sand blasting and brushing operations

ANN-based extraction approach of PV cell equivalent circuit parameters

In most practical cases, a PV array is constructed from a combination of standard PV units (solar cells or panels) connected in series and/or in parallel to obtain the desired power, voltage and current ratings. However, the non-linear behavior of solar cells or panels makes accurate determination of the model parameters a difficult task. A precise determination of the internal physical parameters of cells and panels is not always possible because of the non-uniqueness of the solution. As a result, some parameters of the PV panel model are estimated with non-negligible errors. In this paper, an advanced ANN-based determination approach of PV array parameters from individual cell/panel characteristics is developed for single-diode model. A proper selection of the training points for the ANN is also introduced to improve the estimation of the model. Simulation results obtained for simple case studies using Matlab/Simulink software are presented and discussed. The proposed ANN-based technique made possible more accurate determination of the parameters of the single-diode model with mean errors below 1% for all parameters except for the diode saturation and diffusion current which reached 11%

Analyse de scènes par une méthode du type "K2D" pour la manipulation de pièces en robotique avancée

Nous décrivons le système de vision stéréoscopique appliqué à la Robotique, utilisé au LIMSI. Ce système constitue l'essentiel du module de perception utilisé pour la manipulation d'objets. Les opérations d'assemblage automatique seront assurées par des capteurs d'efforts, l'information géométrique étant fournie par le module de vision. Les caractéristiques de ce système sont les suivantes : - utilisation de la méthode "K2D", - positions des caméras déterminées à partir des images de quatre points d'étalonnage, - angle de vision de la scène quelconque (30°-60°), - images de 256 x 256 x 4 bits, - les objets sont approximés par des polyèdres. Les images sont d'abord traitées afin d'extraire les contours. Puis les contours sont approchés par des segments de droites. L'algorithme hongrois est utilisé pour trouver les segments homologues. La précision des résultats est limitée principalement par les dimensions des pixels et par la précision de l'extracteur de contours

Modelling a positive lightning downward leader to study its effects on engineering systems

A mathematical model of a positive lightning downward leader is presented and its radiated fields calculated. The approach is based on the idea that a substantial similarity exists between lightning phenomena and the discharge in large airgaps. By assuming the discharge channel to be a long conductor and by using an LCR representation for a single conductor line (L, C and R being, respectively, the inductance, the capacitance and the resistance), a predictive model of the positive lightning can be developed enabling description of the evolution of the whole discharge. Taking into account some atmospheric conditions, the model enables the determination of the leader current and the corresponding charge, its propagation velocities, the potential drop along its channel, the power and energy injected into the gap, the leader and streamer lengths through its propagation and a trajectory of the discharge plotted in 3D in real time obtained from a probabilistic distribution. Furthermore, an application concerning the evolution of the radiated electric and magnetic fields of the leader is given. The results obtained are quite satisfactory