One More Solution to Dolomite/Apatite Separation Problem

Dolomite, (Ca, Mg) CO3 represents a problematic impurity in phosphate deposits in different parts of the world Generally, acidulation of phosphate rock requires a feed of less than 0.7% MgO content. Selective mining, to avoid high dolomite deposits, has been practiced by phosphate mining industry. Reduction of the MgO content in the phos-phate rock to less than 1% has been the target of many studies, in various academic and industrial laboratories. However, such goal has not been achieved at a commercial scale yet. Therefore, developing an efficient and economi-cal method for separating dolomite from apatite is an effective way to extend the phosphate mine life. Intense scientific research is being directed towards the imple-mentation of novel approaches dealing with the efficient removal of dolomite from phosphate Reactive Flotation (RF) constitutes a novel technology for solving this problem. RF basically depends on the reactivity of carbonate minerals with acids in which the CO2 gas generates. Encapsulating the liberated CO2 gas at the surface via coating agent renders the particle more buoyant and easy to separate from phosphate. A major advantage is the selectivity of the separation, which is hard to achieve by conventional flotation or other methods for this type of ores due to the similarity of surface properties of apatite and dolo-mite. Researchers at the Particle Engineering Research Center at University of Florida have conducted systematic studies to develop this process and understand its under-lying fundamentals. This presentation discusses such efforts and the obtained results

Therapeutic Considerations Related to Finasteride Administration in Male Androgenic Alopecia and Benign Prostatic Hyperplasia

Finasteride has been used extensively until now as a relative efficient therapeutic option for male androgenic alopecia and benign prostatic hyperplasia. Unfortunately, over time several concerns appeared regarding the frequency and magnitude of adverse effects, which in some cases have been even irreversible. Herein we review the recent literature on this topic, trying to clarify the current safety profile of Finasteride for these two therapeutic indications. We concluded that Finasteride could be retained as a therapeutic approach for male androgenic alopecia, based on two important reasons. First, a synergistic action between a partial inhibitor of 5α-reductase (Finasteride) and another compound (like Minoxidil) are preferable to a complete suppression of 5α-reductase (see Dutasteride), in order to preserve the important physiological roles of dihydrotestosterone. Second, Finasteride side effects can currently be addressed in part prior to the onset of the therapy, by using information about the patient such as hand preference and sexual orientation to predict the risk of adverse effects

Diffusion in a Disk with a Circular Inclusion

We consider diffusion in a disk, representing a cell with a circular interior compartment. Using bipolar coordinates, we perform exact calculations, not restricted by the size or location of the intracellular compartment. We find Green functions, hitting densities and mean times to move from the compartment to the cellular surface and vice versa. For molecules with diffusivity $D$, mean times are proportional to $R^2/D$, where $R$ is the radius of the cell. We find explicit expressions for the dependence on $a^2$ (the fraction of the cell occupied by the intracellular compartment) and on the displacement of the compartment from the center of the cell. We consider distributions of initial conditions that are (i) uniform on the nuclear surface, (ii) uniform on the cellular surface, or (iii) given by the hitting density of particles diffusing from the nuclear to the cellular surface

Therapeutic Considerations Related to Finasteride Administration in Male Androgenic Alopecia and Benign Prostatic Hyperplasia

Finasteride has been used extensively until now as a relative efficient therapeutic option for male androgenic alopecia and benign prostatic hyperplasia. Unfortunately, over time several concerns appeared regarding the frequency and magnitude of adverse effects, which in some cases have been even irreversible. Herein we review the recent literature on this topic, trying to clarify the current safety profile of Finasteride for these two therapeutic indications. We concluded that Finasteride could be retained as a therapeutic approach for male androgenic alopecia, based on two important reasons. First, a synergistic action between a partial inhibitor of 5α-reductase (Finasteride) and another compound (like Minoxidil) are preferable to a complete suppression of 5α-reductase (see Dutasteride), in order to preserve the important physiological roles of dihydrotestosterone. Second, Finasteride side effects can currently be addressed in part prior to the onset of the therapy, by using information about the patient such as hand preference and sexual orientation to predict the risk of adverse effects

Structure and dynamics in protic ionic liquids: a combined optical Kerr-effect and dielectric relaxation spectroscopy study

The structure and dynamics of ionic liquids (ILs) are unusual due to the strong interactions between the ions and counter ions. These microscopic properties determine the bulk transport properties critical to applications of ILs such as advanced fuel cells. The terahertz dynamics and slower relaxations of simple alkylammonium nitrate protic ionic liquids (PILs) are here studied using femtosecond optical Kerr-effect spectroscopy, dielectric relaxation spectroscopy, and terahertz time-domain spectroscopy. The observed dynamics give insight into more general liquid behaviour while comparison with glass-forming liquids reveals an underlying power-law decay and relaxation rates suggest supramolecular structure and nanoscale segregation

Outcomes of “Anterior Versus Posterior Divisional Branches of the Hypogastric Artery as Distal Landing Zone for Iliac Branch Devices”: The International Multicentric R3OYAL Registry

Objective: The aim of this multicentric registry was to assess the outcomes of “anteRior versus posteRior divisional bRanches Of the hYpogastric artery as distAl landing zone for iLiac branch devices (R3OYAL).” Methods: The main exposure of interest for the purpose of this study was the internal iliac artery (IIA) divisional branch (anterior vs posterior) that was used as distal landing zone. Early endpoints included technical success and adverse events. Late endpoints included survival, primary/secondary IIA patency, and IIA branch instability. Results: A total of 171 patients were included in the study, of which 50 received bilateral implantation of iliac branch devices (IBDs). This resulted in a total of 221 incorporated IIAs included in the final analysis, of which 40 were anterior divisional branches and 181 were posterior divisional branches. Technical success was high in both groups (anterior division: 98% vs posterior division: 100%, P =.18). Occurrence of any adverse event was noted in 14% of patients in both groups (P = 1.0). The overall rate of freedom from the composite IBD branch instability did not show significant differences between patients receiving distal landing in the anterior or posterior division of the IIA at 3 years (79% vs 87%, log-rank test =.215). The 3-year estimates of IBD patency were significantly lower in patients who received distal landing in the anterior divisional branch than those who received distal landing in the posterior divisional branch (primary patency: 81% vs 96%, log-rank test =.009; secondary patency: 81% vs 97%, log-rank test <.001). Conclusions: The use of the anterior or posterior divisional branches of the IIA as distal landing zone for IBD implantation shows comparable profiles in terms of immediate technical success, perioperative safety, and side-branch instability up to 3 years. However, IBD patency at 3 years was higher when the distal landing zone was achieved within the posterior divisional branch of the IIA. Clinical Impact: The results from this large multicentric registry confirm that use of the anterior or posterior divisional branches of the internal iliac artery (IIA) as distal landing zone for implantation of iliac branch devices (IBD) shows comparable profiles of safety and feasibility, thereby allowing to extend the indications for endovascular repair of aorto-iliac aneurysms to cases with unsuitable anatomy within the IIA main trunk. Although mid-term rates of device durability and branch instability seem to be similar, the rates of primary and secondary IBD patency at three years was favored when the distal landing zone was achieved in the posterior divisional branch of the IIA

IN-SITU MINING OF PHOSPHATE ORES

Presently the mining of Florida phosphate requires the movement of over a 100-ton of materials (overburden, sand, clay) for every ton of phosphate concentrate recovered. Not only is this energy intensive, but it also causes significant stress on the environment. In 2003, the Department of Energy solicited ideas for innovative mining ideas that could significantly improve the efficiency of mining. An award was made to the University of Florida Engineering Research Center to evaluate the in situ mining of phosphates using an aqueous CO{sub 2} solution. Tests were carried out in a 15.2 cm (6-inch) diameter column, 1.83 meter (6 feet) long at pressures up to 117.2 kg/cm{sup 2} (40 psi). Results to date demonstrate that initially the MgO is leached from the ore and then the phosphate. While the tests are continuing, so far they have not demonstrated P{sub 2}O{sub 5} concentrations that are economically attractive