The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries.

Potassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g-1, and long-term cyclic stability up to 100 cycles at 1 A g-1. The effect of the vanadium valence state and unusual construction of the nanobelts, composed of crystalline and amorphous domains arranged alternately were also discussed in this work. The ex-situ measurements of discharged electrode materials by XRD, MP-AES, XAS and XPS show that during the subsequent charge/discharge cycle the potassium in the K2V6O16·nH2O structure are replacing by lithium. The structural stability of the potassium hexavandate during cycling depends on the initial vanadium valence state on the sample surface and the presence of the "fringe free" domains in the K2V6O16·nH2O nanobelts.

Structure and transport properties of triple-conducting Ba x Sr1-x Ti1-y Fe y O3-δ oxides.

In this work, Ba x Sr1-x Ti1-y Fe y O3-δ perovskite-based mixed conducting ceramics (for x = 0, 0.2, 0.5 and y = 0.1, 0.8) were synthesized and studied. The structural analysis based on the X-ray diffraction results showed significant changes in the unit cell volume and Fe(Ti)-O distance as a function of Ba content. The morphology of the synthesized samples studied by means of scanning electron microscopy has shown different microstructures for different contents of barium and iron. Electrochemical impedance spectroscopy studies of transport properties in a wide temperature range in the dry- and wet air confirmed the influence of barium cations on charge transport in the studied samples. The total conductivity values were in the range of 10-3 to 100 S cm-1 at 600 °C. Depending on the barium and iron content, the observed change of conductivity either increases or decreases in humidified air. Thermogravimetric measurements have shown the existence of proton defects in some of the analysed materials. The highest observed molar proton concentration, equal to 5.0 × 10-2 mol mol-1 at 300 °C, was obtained for Ba0.2Sr0.8Ti0.9Fe0.1O2.95. The relations between the structure, morphology and electrical conductivity were discussed.

[Renal Trauma]. / Traumatismes du rein.

INTRODUCTION: Renal traumas are common, observed in 10% of patients with abdominal trauma. Most renal traumas are blunt, resulting from a direct hit or from an abrupt deceleration. MATERIAL AND METHODS: We realized a synthesis of renal trauma management for nurses. RESULTS: Clinical presentation often encompasses gross hematuria and lumbar pain. The best diagnostic tool is computed tomography (CT) urogram. Based on CT urogram images, renal traumas are classified according to the American Association for the Surgery of Trauma (AAST) classification in five grades of increasing severity. The management is conservative in the vast majority of cases and has been largely simplified over the past few years, being now mostly based on observation. Radiological interventional and endoscopic procedures are used only in very selected cases and surgical exploration has become extremely rare. CONCLUSION: The prognosis has also considerably improved and renal trauma rarely result in death or loss of the kidney nowadays.

[French resident's performance on laparoscopic surgery box trainer: 7-year results of pelvitrainer contests]. / Performance des internes français sur simulateur de chirurgie laparoscopique : les résultats de 7 ans d'olympiades du pelvitrainer.

OBJECTIVES: The study objectives were to analyze the resident's laparoscopic surgery performance in order to build a self-assessment data set, to identify discriminatory exercises and to investigate the suturing time changes. METHODS: From 2007 to 2014, the French Association of Urologist in Training (AFUF) organized 7 pelvitrainer contests. Participant scores on 11 laparoscopic surgery exercises were evaluated. RESULTS: Sixty-six residents participated to these contests and performed 11 exercises each. Twenty-two (33.3 %) participants were beginners, 26 (39.4 %) intermediates et 18 (27.3 %) experienced. The participant scores were gathered into a data set including the average time per exercise. We found a time scoring improvement related to the resident experience for all exercises. A significant decline in time was noted for exercise 8 and 9 between beginners and intermediates (139s [±71]), (173.9s [±118.3]) and between beginners and experienced (80.6s [±26.7]), (94,1s [±42.7]) with a P<0.05. The correlation coefficient for the exercise 11 duration (vesico-uretral anastomosis) was 0.04 over a 7-year period (P=0.44). CONCLUSION: The study provided a data set on 11 laparoscopic surgery tasks which can be consulted by all residents as a reference in a self-assessment process. Two exercises (8 and 9) discriminated beginners from intermediates and experienced groups and could be used as a benchmark ahead of an operating room procedure. The vesico-uretral anastomosis duration (exercise 11) did not improve significantly between 2006 and 2014. LEVEL OF EVIDENCE: 4.

Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method.

Molten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0.995Ca0.005NbO4 and BaCe(0.9-x)Zr(x)Y0.1O3. Single-phase lanthanum niobate formed in all studied conditions of the synthesis, whereas in the case of barium cerate-zirconate MSS led to forming two crystalline phases: barium cerate and barium zirconate. The heating temperature and time as well as the salt content most strongly influenced the shape and size of particles. The influence of other parameters on the powder morphology was weaker. Despite differences in size and morphology, all groups of the La0.995Ca0.005NbO4 powder obtained with the MSS method pressed into pellets and sintered gave a dense ceramic material. On the other hand in the case of barium cerate-zirconate regardless of synthesis and sintering conditions the ceramics were porous.

[Renal unilateral oncocytis: case report]. / Oncocytose rénale unilatérale: à propos d'un cas.

The renal oncocytoma tumors are rare (5% of renal tumors). These benign tumors are incidentally diagnosed most often in an asymptomatic form. Sometimes it is multiple bilateral tumors affecting the renal parenchyma and forming a renal oncocytosis. We report the case of a unilateral right renal oncocytosis, very rare situation, characterized by a right renal parenchymal nodules with oncocytoma and a normal left kidney.

Benefits of primary surgical resection for symptomatic urethral prolapse in children.

OBJECTIVE: Urethral prolapse (UP) is a complete eversion of the distal urethral mucosa through the external meatus. UP must be distinguished by examination from trauma, prolapsed ureterocele, tumors or sexual abuse. Its management remains controversial. The aim of the study was to promote the benefits of primary surgical management for UP. METHODS: A retrospective multicenter review of children who received surgery for UP between 1991 and 2011 was carried out. Non-complicated UP was primarily treated conservatively. A total of 19 patients were referred for complicated UP and underwent resection of the prolapsed urethral mucosa. RESULTS: The mean delay in diagnosis was 2.2 days (range 1-6) and the most common symptoms were vaginal spotting and bleeding. No predisposing factor was found, but most patients had a mean weight, height and BMI greater than the 50th percentile. All patients underwent surgery successfully. One patient experienced a complication, i.e., dysuria. There was no case of recurrence after a mean 28 months of follow-up. CONCLUSION: Early detection is based on bedside examination. The first-line treatment strategy for uncomplicated UP should be conservative management. Surgical resection is safe and effective for patients with significant symptoms.