Thermoelectric Analysis of ZnSb Thin Films Prepared by ns-Pulsed Laser Deposition.

Zinc antimonide (ZnSb) is a promising thermoelectric material for the temperature range 300­ 600 K. ZnSb thin films were prepared by nanosecond Pulsed Laser Deposition (PLD) to evaluate the performance of nanostructured films for thermoelectric conversion by the determination of the Power Factor. A study of the influence of structural, compositional and thermoelectric properties of thin films is reported as a function of different deposition parameters, such as repetition rate, pulse energy, and substrate temperature. The evaluation of a thin film ZnSb compound with excess Sb has been performed to verify the variation of the thermoelectric properties. The obtained results are reported and discussed in the 300­600 K temperature range.

Association between pigs with high caecal Salmonella loads and carcass contamination.

Contaminated pork is a significant source of foodborne Salmonella infections. Pork is contaminated at the slaughterhouse; however, the mechanisms driving Salmonella contamination of carcasses are still poorly understood. The aim of this study was to investigate whether the amount of Salmonella carried by slaughtered pigs in their guts has an influence on carcass contamination. On that account, we tested whether the number of carcasses contaminated during a slaughter day was associated with the prevalence of highly contaminated pigs (HCP: Salmonella caecal loads ≥3log/g), or with the prevalence of pigs that simply carry Salmonella spp. in their guts. Three hundred and six pigs were sampled in a slaughterhouse from Central Italy. Salmonella loads in the caecum and on the carcass of each pig were estimated by the most probable number (MPN) technique. The overall prevalence of Salmonella was 34.64% and 7.19% for the caeca and carcasses, respectively. S. Derby and Salmonella enterica 4,[5],12:i:- were the most frequently isolated serovars. The prevalence of HCP was 11.44%. We found a higher number of contaminated carcasses on days of high prevalence of HCP than on days of low prevalence of HCP (p=0.0011). Conversely, carcass contamination did not vary with the prevalence of pigs that simply carried Salmonella spp. in their guts (p=0.7970). Therefore, the prevalence of HCP, but not the prevalence of pigs carrying Salmonella spp., was related to carcass contamination. Taken together, these findings suggest that reduction of Salmonella loads in the guts of slaughtered pigs would result in fewer contaminated carcasses, and consequently, help to minimise the risk of human infection due to the consumption of contaminated pork.

X-ray microdiffraction and urine: a new analysis method of crystalluria.

The qualitative and quantitative analyses of crystalluria have clinical significance in the diagnosis and prognosis of urolithiasis. The aim of this paper is to provide a new accurate methodology to get qualitative and quantitative data on urine particulate in patients with renal stone disease.The procedure involves a urine collection, the separation of the solid residual by centrifugation, and its analysis by X-ray diffraction, utilizing a micro-diffractometer in order to analyze very low amounts of residual. The spectrum obtained was converted into 2 θ -I profiles and quantitatively refined by Rietveld method. The proposed methodology has the advantage to accurately quantify all crystalline phases and the amorphous component of the urine; anyway urine samples have to be centrifuged and analysed as soon as possible, because the quantitative results obtained by the X-ray microdiffraction showed that after some days and at room temperature urine increased significantly both amorphous and crystalline phases.

Colloidal mercury (Hg) distribution in soil samples by sedimentation field-flow fractionation coupled to mercury cold vapour generation atomic absorption spectroscopy.

Diverse analytical techniques are available to determine the particle size distribution of potentially toxic elements in matrices of environmental interest such as soil, sediments, freshwater and groundwater. However, a single technique is often not exhaustive enough to determine both particle size distribution and element concentration. In the present work, the investigation of mercury in soil samples collected from a polluted industrial site was performed by using a new analytical approach which makes use of sedimentation field-flow fractionation (SdFFF) coupled to cold vapour generation electrothermal atomic absorption spectroscopy (CV-ETAAS). The Hg concentration in the SdFFF fractions revealed a broad distribution from about 0.1 to 1 µm, roughly following the particle size distributions, presenting a maximum at about 400-700 nm in diameter. A correlation between the concentration of Hg in the colloidal fraction and organic matter (O.M.) content in the soil samples was also found. However, this correlation is less likely to be related to Hg sorption to soil O.M. but rather to the presence of colloidal mercuric sulfide particles whose size is probably controlled by the occurrence of dissolved O.M. The presence of O.M. could have prevented the aggregation of smaller particles, leading to an accumulation of mercuric sulfides in the colloidal fraction. In this respect, particle size distribution of soil samples can help to understand the role played by colloidal particles in mobilising mercury (also as insoluble compounds) and provide a significant contribution in determining the environmental impact of this toxic element.

Percutaneous management of complications of tuberculous spondylodiscitis: short- to medium-term results.

PURPOSE: Psoas abscesses are the most frequent complication of tuberculosis with skeletal involvement. The aim of this paper is to report our experience with the systematic application of percutaneous drainage to tuberculous psoas abscesses. MATERIALS AND METHODS: Between January 1997 and December 2005, 23 patients (14 men and nine women; age range 21-48 years), after a previous study with computed tomography (CT) and/or magnetic resonance (MR) imaging, underwent percutaneous drainage of a tuberculous fluid collection in the psoas muscles. Follow-up consisted of monthly clinical and laboratory assessment, and plain chest radiography and spinal CT every 6-12 months. RESULTS: Spondylodiscitis involved the thoracolumbar spine. Fluid collections were bilateral in 14 cases and communicating in ten of these. Maximum transverse diameter was 7 cm, whereas longitudinal diameter was 14 cm. Placement of the drainage catheter was successful in all cases, and the catheter was left in place for 5-36 (mean 18.4) days. Symptom regression occurred immediately after drainage of the fluid collection. The drainage procedure was curative in 100% of cases. Dislodgement of the drainage catheter occurred in two cases as a result of excessive traction during dressing removal. CONCLUSIONS: A serious complication of bone tuberculosis, psoas abscesses, can be effectively treated by percutaneous drainage, leading to immediate pain resolution. The drainage catheter requires daily monitoring to identify when it can be safely removed without risk of recurrence.

Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clay minerals.

The interaction between Cd(II) in aqueous solution and two 2:1 expandable clay minerals (i.e., montmorillonite and vermiculite), showing different layer charge, was addressed via batch sorption experiments on powdered clay minerals both untreated and amino acid (cysteine) treated. Reaction products were characterized via X-ray powder diffraction (XRDP), chemical analysis (elemental analysis and atomic absorption spectrophotometry), thermal analysis combined with evolved gases mass spectrometry (TGA-MSEGA) and synchrotron-based X-ray absorption spectroscopy via extended X-ray absorption fine structure (EXAFS) characterization. Sorption isotherms for Cd(II) in presence of different substrates, shows that Cd(II) uptake depends both on Cd(II) starting concentration and the nature of the substrate. Thermal decomposition of Cd-cysteine treated clay minerals evidences the evolution of H(2)O, H(2)S, NO(2), SO(2), and N(2)O(3). These results are well consistent with XRDP data collected both at room and at increasing temperature and further stress the influence of the substrate, in particular cysteine, on the interlayer. EXAFS studies suggest that Cd(II) coordinates with oxygen atoms, to give monomer complexes or CdO molecules, either on the mineral surface and/or in the interlayer. For Cd-cysteine complexes EXAFS data agree with the existence of Cd-S clusters, thus suggesting a predominant role of the thiol group in the bonding of Cd with the amino acid.

Non-Fermi-liquid behavior and double-exchange physics in orbital-selective Mott systems.

We study a multiband Hubbard model in its orbital-selective Mott phase, in which localized electrons in a narrow band coexist with itinerant electrons in a wide band. The low-energy physics of this phase is shown to be given by a generalized double-exchange model. The high-temperature disordered phase thus differs from a Fermi liquid, and displays a finite scattering rate of the conduction electrons at the Fermi level, which depends continuously on the spin anisotropy.

Mott transition and Kondo screening in f-electron metals.

We study how a finite hybridization between a narrow correlated band and a wide conduction band affects the Mott transition. At zero temperature, the hybridization is found to be a relevant perturbation, so that the Mott transition is suppressed by Kondo screening. In contrast, a first-order transition remains at finite temperature, separating a local-moment phase and a Kondo-screened phase. The first-order transition line terminates in two critical end points. Implications for experiments on f-electron materials such as the cerium alloy Ce0.8La0.1Th0.1 are discussed.

[Percutaneous treatment of varicocele. 13-year experience with the transbrachial approach]. / Trattamento percutaneo del varicocele. 13 anni di esperienza transbrachiale.

PURPOSE: To report our experience using the transbrachial approach, which is easily accepted by the patient, in the treatment of varicocele. MATERIAL AND METHODS: Between January 1986 and December 1998, 1490 patients with clinical or subclinical varicocele, but with seminal fluid alterations, underwent spermatic phlebography using the transbrachial approach. Since 1991 the procedure has also been adopted at the Unit of Pediatric Surgery of our hospital, which proposes it as a first choice treatment in adolescents with varicocele. The procedure consists in accessing the basilic vein at the elbow level percutaneously and using a hydrophile guidewire and multipurpose angiographic catheter to reach and catheterise the spermatic vein responsible for the varicocele. During the first years, we used sclerotherapy alone; subsequently, if the varicocele recurred or if the reflux was refractory to sclerotherapy or if the veins were large we adopted vein embolisation. Follow-up was one year and consisted of testicular ultrasound, Doppler flowmetry and/or color Doppler ultrasound at one, six and twelve months after the procedure. Patients were considered restored if they were free of symptoms, showed no venous reflux and/or had normal seminal fluid parameters and improved if they were free of symptoms but still presented venous reflux. Varicocele was considered persistent if the procedure failed to produce any beneficial effects, and recurrent if, although absent at the first follow up, it reappeared after the fifth month. RESULTS: We found 1296 (86.9%) cases of left varicocele, 25 of right varicocele and 169 (11.3%) of bilateral varicocele. In all cases, the symptoms disappeared after the percutaneous procedure. Duration of radioscopy was reduced to 3.5'; the procedure lasted 90' for the monolateral varicoceles and 120' for the bilateral forms. 313 diagnostic procedures were performed (20.7%). The procedure could not be completed in 104 patients (6.8%) due to basilic vein spasms, difficulties encountered in catheterizing the spermatic vein and, particularly in pediatric patients, anatomic variations. A total of 1195 (79.2%) procedures were completed: sclerotherapy alone in 642 patients and sclerotherapy followed by scleroembolisation in 527. Sclerotherapy alone was sufficient to restore 524 patients (86.6%), while 384 (78.5%) required scleroembolization. A small number of patients underwent scleroembolization alone, which brings the success rate for the two procedures to 82% and 84%, respectively. No serious side-effects were noted. DISCUSSION: The transbrachial approach in spermatic phlebography has proved to be a safe and effective technique for the treatment of both monolateral and bilateral varicocele. Furthermore, the procedure is well accepted by patients and can be performed in a day-care setting. In some cases, we only obtained partial results because of the large caliber of the spermatic vein; in other cases, we were unable to complete the procedure due to anatomic variations or to the spasm of the basilic vein. CONCLUSION: The safety and effectiveness of this procedure make it a valid alternative to traditional surgery, that should be considered as a possible first-choice treatment for varicocele in adolescents.

Varicocele: a multidisciplinary approach in children and adolescents.

PURPOSE: To minimize varicocele treatment in children and adolescents a multidisciplinary approach that includes surgery and operative radiology has been used at our institution since 1991. We present our results during this 7-year period. MATERIALS AND METHODS: From January 1991 to December 1997 we examined 477 patients 4 years 5 months to 25 years 4 months old (mean age 13 years 3 months) with varicocele, of whom 367 (396 varicoceles) required treatment. Percutaneous sclero-embolization was suggested as the primary treatment of choice in all cases, while surgery was reserved for select cases. A total of 366 cases followed at least 6 months (mean 1 year) were entered into this study. RESULTS: Only 7.1% of the patients or families preferred surgery. In 47 patients sclero-embolization was not possible due to technical problems or vascular anomalies. Sclero-embolization was successful in 79.4% of 277 patients, and retroperitoneal ligation was successful in 88.7% of 124. Since 1995 ligation of the whole spermatic bundle above the vas deferens has been preferred, and only 1 recurrence has been observed in 60 cases. CONCLUSIONS: Percutaneous sclero-embolization is a minimally invasive treatment of varicocele that is feasible in children and adolescents. Most patients prefer this therapy, although it is not as safe as surgery. When open surgery is required, complete ligation of the whole vascular pedicle above the vas deferens offers excellent success.

[Cystic lymphangioma of the mesentery. A case of intestinal obstruction and a brief review of the literature]. / Linfangioma cistico del mesentere. Un caso di occlusione intestinale e breve revisione della letteratura.

Mesenteric cystic lymphangioma is a rare pathology which is not often described in the literature. Moreover, its etiopathogenesis is still uncertain. It may remain asymptomatic or it may present aspecific painful abdominal symptoms of the sub-acute type correlated with compressive phenomena or, more rarely, with acute intestinal obstruction. Surgery is the only form of treatment for both acute and sub-acute abdominal forms. The authors report a case of two mesenteric cystic lymphangiomas of the ileum which led to the onset of intestinal obstruction caused by ileal volvulus in a 45-year-old man.

Gastrointestinal tubercular arteritis during HIV infection.

Although digestive tract is often involved in HIV disease, severe gastrointestinal bleeding rarely occurs. We describe a case of severe gastrointestinal bleeding associated with a mycobacterium tuberculosis arteritis of colonic tract. It is reported a morphology change of mesenteric arteries by mycobacterium tuberculosis revealed by angiography. The superselective embolization of branches mesenteric inferior artery resolved the important bleeding without surgical intervention. In AIDS patients, during intestinal tuberculosis, massive enteric-hemorrhage suggests for involvement of mesenteric arteries by mycobacterium tuberculosis. An angiography is basic to discover bleeding and if necessary for the therapeutic treatment.

[Deep venous thrombosis and the prevention of a pulmonary embolism with temporary caval filters: the experience in 2 pediatric cases]. / Trombosi venosa profonda e prevenzione dell'embolia polmonare con filtri cavali temporanei: esperienza in due casi pediatrici.

Deep venous thrombosis with pulmonary embolism is considered rare in pediatric population, but a literature review points out this disease more frequent than would be expected in children. The low incidence and the poor consideration of this occurrence in pediatric age group, cause the thromboembolic disease with pulmonary involvement an often missed diagnosis. The illness is usually related to intravenous catheters, surgery, trauma, sepsis, prolonged immobilization, neoplasia, drugs, some congenital or acquired diseases. The Authors report their experience with two pediatric cases of inferior vena cava thrombosis and pulmonary embolism treated with anticoagulant therapy, temporary vena cava filters and locoregional fibrinolysis.

Factors influencing vision with rigid gas permeable alternating bifocals.

This study assessed the fitting and visual performance of a rigid, gas permeable (RGP), monocentric, alternating bifocal. Fourteen presbyopic eyes each wore 24 different lenses consisting of all combinations of 2 diameters, 2 segment heights, 2 prism ballasts, and 3 fitting relations. The influence of parameter selection on visual performance and the usefulness of clinical measurements in predicting visual performance were determined statistically by multivariate logistic regression. Our results showed that prism, segment height, and the fitting relation can influence distance and near visual performance. Lens movement, postblink segment positioning, and return time were the most useful measured predictors of visual performance.