Galvanically replaced Au-Pd nanostructures: study of their enhanced elemental mercury sorption capacity over gold.

In this study, the efficiency of bimetallic (Au-Pd) nanostructures over Au and Pd substrates for elemental mercury (Hg(0)) vapor sensing and capturing was investigated. The quartz crystal microbalance (QCM) technique was utilized to determine the sorption kinetics and quantity of Hg(0) captured by the developed Au-Pd surfaces. The Au-Pd nanostructures were synthesized directly on the QCM's Pd electrodes using galvanic replacement (GR) reactions for periods of 0.5 to 48 hours, which enabled the ratio of Au to Pd on the surface to be controlled. It was observed that the mercury affinity of the surface does not increase with increased Au loading, rather the Au : Pd ratio obtained after a GR reaction time of 1 hour was found to have the highest affinity towards Hg(0) vapor under the GR reaction conditions used in this study. Any further increase in Au : Pd ratio at the surface resulted in reduced affinity for Hg(0) with the Au-rich Au-Pd nanostructures behaving similar to an Au-control substrate. However, short reaction periods (i.e. 1 h) produced small Au nanoparticles increasing the surface to volume ratio for better sensitivity and response times. Remarkably, the QCM data showed that GR based Au-Pd nanostructures removed 2.5 µg cm(-2) of Hg(0) from a gas stream containing 9.1 mg m(-3) of Hg(0) vapor within the first 3 minutes of exposure. The control surfaces (Pd and Au based thin-films) on the other hand took a total of 106 and 159 minutes, respectively to reach the same Hg(0) sorption capacity from the same gas stream.

Creating gold nanoprisms directly on quartz crystal microbalance electrodes for mercury vapor sensing.

A novel electrochemical route is used to form highly {111}-oriented and size-controlled Au nanoprisms directly onto the electrodes of quartz crystal microbalances (QCMs) which are subsequently used as mercury vapor sensors. The Au nanoprism loaded QCM sensors exhibited excellent response-concentration linearity with a response enhancement of up to ∼ 800% over a non-modified sensor at an operating temperature of 28 °C. The increased surface area and atomic-scale features (step/defect sites) introduced during the growth of nanoprisms are thought to play a significant role in enhancing the sensing properties of the Au nanoprisms toward Hg vapor. The sensors are shown to have excellent Hg sensing capabilities in the concentration range of 0.123-1.27 ppm(v) (1.02-10.55 mg m(-3)), with a detection limit of 2.4 ppb(v) (0.02 mg m(-3)) toward Hg vapor when operating at 28 °C, and 17 ppb(v) (0.15 mg m(-3)) at 89 °C, making them potentially useful for air monitoring applications or for monitoring the efficiency of Hg emission control systems in industries such as mining and waste incineration. The developed sensors exhibited excellent reversible behavior (sensor recovery) within 1 h periods, and crucially were also observed to have high selectivity toward Hg vapor in the presence of ethanol, ammonia and humidity, and excellent long-term stability over a 33 day operating period.

[Tumoral form of abdominal actinomycosis: a retrospective case series of seven patients]. / Actinomycoses abdominales à forme tumorale : une série rétrospective de sept observations.

PURPOSE: Abdominal actinomycosis is an uncommon chronic infectious disease due to Actinomyces, a Gram-positive bacteria. This saprophytic bacteria of digestive tract and genital mucosa can occasionally become pathogenic mimicking a digestive neoplasia. The aim of this study was to underline diagnostic features of abdominal actinomycosis and to summarize data about clinical, diagnostic and therapeutic approach of this type of infection. PATIENTS: From January 1995 to December 2007, retrospective data concerning patients with abdominal actinomycosis who were followed-up in the University Hospital Sahloul (Sousse, Tunisia) were analysed. RESULTS: Seven patients with abdominal actinomycosis were identified during the study period. All presented with an abdominal mass. The diagnosis of actinomycosis was obtained after surgical resection in all cases. The histological study permitted the diagnosis in six cases, and the surgical samples grew up Actinomyces in two patients. For the five patients who received prolonged and adapted antibiotic therapy, a favourable outcome was observed. CONCLUSION: Actinomycosis must be included in the differential diagnosis of invasive abdominal lesions with "malignant appearance".

[Hemoperitoneum secondary to the rupture of superficial veins of a uterine leiomyoma]. / Hémopéritoine secondaire à la rupture des veines superficielles d'un léiomyome utérin.

The most frequent cause of gynaecological hemoperitoneum is ruptured ectopic pregnancy. An uncommon cause of hemoperitoneum is rupture of uterine leiomyoma. We report one case of massive intraperitoneal hemorrhage and hypovolemic shock due to ruptured uterine leiomyoma vessels. The patient was treated with myomectomy and the postoperative course was uneventful. These case suggest that massive intra peritoneal hemorrhage associated with uterine leiomyoma should be considered in women with hypovolemic shock and pelvic mass.

Pulmonary function tests, high-resolution computerized tomography, alpha1-antitrypsin measurement, and early detection of pulmonary involvement in patients with systemic sclerosis.

OBJECTIVE: Pulmonary disease represents a major complication of systemic sclerosis (SSc). However, pulmonary involvement is commonly silent. In this study, we investigated the relationship between serum alpha1-antitrypsin and other means of assessing pulmonary involvement. METHODS: Twenty-two patients affected by SSc were studied (mean age 37.6+/-14.3 years, mean duration of disease 9.9+/-11.9 years). Fourteen had the diffuse form of disease (dSSc) and eight had the limited form (lSSc). All patients underwent pulmonary function tests, high-resolution computed tomography (HRCT) of the lungs, echocardiography, and serum assessment of alpha1-antitrypsin. RESULTS: Mean percentage of predicted values of forced vital capacity was lower in patients with dSSc than with lSSc (72.3+/-17.8 vs 74.5+/-8, P=NS). Mean percentage of predicted values of forced expiratory volume in 1-s forced vital capacity (FEV1/FVC) was lower in patients with lSSc (79.8+/-7.5 for lSSc vs 84.4+/-7.8 for dSSc, P= NS). The overall HRCT score was 5.6+/-5.9 with no significant difference between disease subgroups. Pulmonary hypertension was detected in two cases, both with dSSc. Alpha1-antitrypsin was significantly higher in patients than in controls (P < 0.01), with no significant difference between disease subgroups, and correlated significantly with ground glass opacities in H RCT (P < 0.05) and the detection of diffusion defects (r= -0.61, P<0.01). No significant correlation was observed between skin score or degree of dyspnea with HRCT score, lung volume, or carbon monoxide diffusing capacity. CONCLUSION: Restrictive lung disease was more pronounced in patients with dSSc. Alpha1-antitrypsin levels correlated significantly with ground glass opacities, an early finding of pulmonary involvement in SSc. Extent and severity of skin involvement and degree of dyspnea were not related to pulmonary involvement.

[Treatment of perforated duodenal ulcers]. / Traitement des ulcères duodénaux perforés.

Final surgical treatment of perforated duodenal ulcer is not admitted by all authors. The aim of this study is to evaluate final treatment of perforated duodenal ulcer among 110 patients. 74.5% were aged less than 41 years. 107 patients underwent surgery. Treatment was based on: truncal vagotomy with pyloroplasty (99 cases), truncal vagotomy with closure of duodenal perforation and gastroentero-anastomosis (5 cases), truncal vagotomy with antrectomy (1 case) and simple closure of the duodenal perforation (2 cases). Mortality of truncal vagotomy with pyloroplasty was about 1%. According to the visick evaluation, clinical results were good in 95.3% cases without recurrent ulcer with a mean follow up of 4 years. According to our results truncal vagotomy with pyloroplasty seems to be a safe procedure in the management of perforated duodenal ulcer and more over gives good long-term results in control of peptic disease.

[Persistent external biliary fistula after surgery for hepatic hydatid cyst]. / Les fistules biliaires externes intarissables après chirurgie de l'hydatidose hépatique.

Post-operative persistent biliary fistulae due to hydatid cysts are difficult to manage. We report 3 cases of external biliary fistulae complicating surgery for hepatic hydatid cyst (2 cases) and intraperitoneal hydatid cyst (1 case). Endoscopic sphincterotomy was successful with closure of the fistulae in all patients. This procedure should be the first-line treatment for post-operative external biliary fistulae related to liver hydatid disease. Usually difficult and haemorrhagic surgery can thus be avoided.