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Chalcopyrite ores are processed mostly by pyrometallurgical techniques due to the refractory nature of the mineral to the current hydrometallurgical techniques. In order to overcome such refractoriness, pretreatment steps such as sulfurization may be applied to produce different copper phases and therefore improve the metal dissolution in the leaching step. The current study investigated the reaction products of the reaction between chalcopyrite and elemental sulfur at different chalcopyrite/sulfur ratios (1/1 and 1/2), reaction time (60 min and 90 min), and temperature (350ºC, 400°C and 450ºC). The sulfurization experiments revealed that covellite, nukundamite, bornite, and pyrite-like compounds were produced according to the experimental conditions applied. Then, the sulfurization products were submitted to chemical leaching tests at temperatures ranging from 32ºC to 70ºC, whereas bioleaching tests were also carried out with Acidithiobacillus ferrooxidans, at 32ºC. In the chemical leaching experiments at 70ºC, only 14% copper was recovered from the original chalcopyrite sample while the maximum copper extraction was 78% from bornite produced at 450ºC (90 min and mass ratio of chalcopyrite/sulfur of 1/2). On the other hand, copper extraction achieved 96% from the same sulfurization product containing synthetic bornite within 20 days of bioleaching. Bioleaching of the original chalcopyrite sample implied in a copper recovery of only 25% in the same period. Summarizing, the current work showed that chalcopyrite sulfurization at 450ºC was able to transform chalcopyrite into a bornite-like phase, which was chemically leached and bioleached by At. ferrooxidans. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: While head-to-head clinical trials demonstrate pegfilgrastim to be as efficacious as filgrastim in reducing chemotherapy-induced neutropenia, these studies lacked the statistical power to demonstrate better outcomes with one therapy compared to the other. Our objective was to obtain a pooled estimate of the effect of pegfilgrastim compared with filgrastim on incidence of febrile neutropenia (FN), and related outcomes among patients with solid tumors and malignant lymphomas receiving myelosuppressive chemotherapy. RESEARCH DESIGN AND METHODS: We searched PubMed and EMBASE for articles published from January 1, 1990 to August 31, 2006 reporting on randomized controlled trials (RCTs) that compared the efficacy and safety of pegfilgrastim versus filgrastim. We only accepted studies in which filgrastim (5 microg/kg/day) and pegfilgrastim (100 microg/kg or a fixed dose of 6 mg) were administered at approved doses indicated on the package insert. Pooled relative risk (RR) was estimated using the conservative random effects, empirical Bayesian method of Hedges and Olkin. MAIN OUTCOME MEASURES: Rates of grade IV neutropenia and of FN, time to absolute neutrophil count (ANC) recovery, and bone pain. RESULTS: We identified five RCTs, with a total of 617 patients, evaluating the efficacy of a single dose of pegfilgrastim per cycle versus daily filgrastim injections. Although only one study had a statistically significant difference in FN reductions favoring pegfilgrastim over filgrastim (relative risk reduction of 50%; p = 0.027), the pooled RR showed a statistically significant favorable result for pegfilgrastim (RR = 0.64; 95% CI, 0.43-0.97). Grade IV neutropenia rates (for cycle 1: RR = 0.99; 95% CI, 0.91-1.08; cycle 2: RR = 0.88; 95% CI, 0.70-1.11; cycle 3: RR = 0.80; 95% CI, 0.47-1.36; cycle 4: RR = 0.90; 95% CI, 0.71-1.13), time to ANC (SMD = 0.11, 95% CI, -0.34-0.56), and incidence of bone pain (RR = 0.95; 95% CI, 0.76-1.19) were similar between the two G-CSFs. The included trials varied in the type of cancer, chemotherapy regimen and type of trial. CONCLUSION: A single dose of pegfilgrastim performed better than a median of 10-14 days of filgrastim in reducing FN rates for patients undergoing myelosuppressive chemotherapy. [ABSTRACT FROM AUTHOR]

Fish fillets present large variation in volume during drying, due to their high initial moisture content. A kinetical study on the drying of fish muscles in slabs shaped with constant air conditions at three temperature levels is presented. For the modeling of the drying process of these materials, a diffusive model can be used, assuming a one-dimensional volume change. A linear correlation was considered between the thickness of the material and its moisture content, where the linear shrinkage coefficient has been determined. The resulting dimensionless nonlinear partial differential equation was solved numerically by the finite differences technique. [ABSTRACT FROM AUTHOR]

Aneurysms of the vein of Galen (AVG) represent less than 1% of all intracranial arteriovenous malformations. Two cases of prenatal diagnosis made by color Doppler ultrasonography at 32 weeks of gestation are reported. Both cases presented with antenatal mild cardiomegaly and both developed severe cardiac failure in the neonatal period. Embolization was unsuccessful and both infants died. These cases highlight the need for a careful evaluation of the time and mode of delivery; embolization must be performed after a fully informed decision. [ABSTRACT FROM AUTHOR]

The article studies acute ascending aortic dissection during pregnancy by researchers from Lisbon, Portugal. Although acute aortic dissection is a very rare case, it is a life-threatening emergency for both the mother and the fetus when it occurs, usually during the during the third trimester or puerperium. The condition necessitates a high index of clinical suspicion and an immediate multidisciplinary approach.

We compute the volume of flushed sediments in a dam using photogrammetry-based multi-temporal surveys with an unmanned aerial system (UAS). Coping with sediments accumulation and erosion in reservoir is a living topic in modern hydraulics of dams, since the increase of sediment may reduce the reservoir capacity, endanger dam's stability, and represent an economical loss. As a result, a number of remedies can be considered, such as flushing or mechanical removal. To evaluate the performance of these operations, measuring the volume of removed sediments and their spatial distribution is important. Here, we show that photogrammetry from UASs represents a suitable solution to reckon the volume of removed sediments. The case study is the Fusino dam (Lombardia region, Northern Italy). Two surveys were performed, before and after sediment removal. In both cases, the flight has been planned with an average flight height equal to 65 m, leading to a mean ground sample distance (GSD) equal to 0.013 m. The 22 ground control points (GCP) used to adjust the photogrammetric block were measured with both global navigation satellite system (GNSS) and a total station. Each survey produced a cloud of about 40 million of points. Moreover, the digital surface model (DSM) produced by each photogrammetric flight has been validated with sample points measured with a robotic total station. Results show high consistency between computed DSMs and validation dataset, with a mean height difference equal, respectively, to 0.003 and ¡0.004 m considering the two different surveys, with a standard deviation around 0.05 m in both the cases. The volume of sediments flushed was estimated to be about 26,000 m3, which represents about 2%–3% of the total reservoir capacity. We estimated also a 6% difference in terms of reservoir capacity between the present condition and the no-sediments condition. [ABSTRACT FROM AUTHOR]