Search

Current production of metallurgical-grade Si relies on an energy-intensive process based on complex solid-liquid-gas reactions in an electric submerged arc furnace using graphite electrodes. This is followed by a slow Siemens process to grow ultra-high purity solar-grade silicon. Due to increasing decarbonization and environmental pressures that the metal industry is facing, new sustainable process technologies are required. This study is part of a broader investigation on pyrometallurgical electrorefining of silicon in the presence of slag and provides the basis for impurity behaviour in Si-slag system without an imposed electromotive force. For the first time, experimental technique of drop-quenching followed by direct phase analysis techniques of electron microprobe analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) were employed in silicon processing environment. The experiments were carried out to define the distribution coefficients of minor elements (B, P) between Si and SiO2-CaO-Al2O3 at silica and alumina crucibles under inert Ar gas at 1500 °C. The results presented are highly novel and show the influence of slag composition and process conditions on the element properties. The experimental results were compared to the computational simulation results by FactSage© using its FToxid and FSupsi databases. The results can be utilized to design Si–slag process for primary ore resources and for secondary silicon-rich scraps in pyrometallurgical smelting environment, as well as to potentially improve the thermochemical databases of computational simulation programs.

This paper examines the institutionalisation of psychiatric treatment in Ken Kesey’s One Flew Over the Cuckoo’s Nest. Taking up the work of Michel Foucault, the paper examines how those suffering from mental illness were classified as disruptive and unfit for society, subsequently labelled mad and institutionalised in facilities more akin to semi-judicial structures than medical facilities. McMurphy, having manipulated a transfer for himself from a state work farm to what he perceives will be the less rigorous confines of a mental institution, epitomises the disruptive presence of the madmen, bringing a world of disorder and chaos to the staff and patients of the mental ward. Self-proclaimed as the head “bull goose looney”, McMurphy reflects the counter-culture movements of the 1960s in the United States in his rejection of the rules and regulations imposed upon him by what amounts to a totalitarian system of control. A wild indomitable force of nature, McMurphy becomes a totem for Chief and the other patients, an embodiment of the human spirit the patients have forfeited inside the institutional system.

Cascade predictive genetic testing is available for many families as a means to identify individuals at risk of long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC). The general issue of offering predictive genetic testing to minors has been an area of ethical debate among genetic counselors and other healthcare professionals for many years. An online questionnaire was circulated to four international genetic counseling associations to assess the views of cardiac genetic counselors regarding when to offer predictive genetic testing to children at risk of LQTS, CPVT, HCM, and ARVC. Analysis was both quantitative and qualitative. The study sample comprised 98 respondents. The majority reported that they offer predictive genetic testing before 5 years of age to children at risk of LQTS (83%) and CVPT (75%) and before 10 years of age to children at risk of HCM (66%) or ARVC (70%). Influencing factors included country of practice, clinical setting, and years of experience. The rationale provided for when to offer predictive genetic testing is encompassed by the ethical principles of beneficence, non‐maleficence, autonomy, and informed consent. In conclusion, significant practice variation exists among cardiac genetic counselors regarding predictive genetic testing for children at risk of an inherited cardiomyopathy. These variations call for more research in the area to assist with the development of evidence‐based guidelines. [ABSTRACT FROM AUTHOR]

Background Communication between professionals, patients and families about palliative and end-of-life care after stroke is complex and there is a need for educational resources in this area. Methods To explore the key learning needs of healthcare professionals, a multidisciplinary, expert group developed a short electronic survey with open and closed questions, and then distributed it to six UK multiprofessional networks and two groups of local clinicians. Results A total of 599 healthcare professionals responded. Educational topics that were either definitely or probably needed were: ensuring consistent messages to families and patients (88%); resolving confiicts among family members (83%); handling unrealistic expectations (88%); involving families in discussions without them feeling responsible for decisions (82%); discussion of prognostic uncertainties (79%); likely mode of death (72%); and oral feeding for 'comfort' in patients at risk of aspiration (71%). The free-text responses (n = 489) and 82 'memorable' cases identified similar themes. Conclusion Key topics of unmet need for education in end-of-life care in stroke have been identified and these have infiuenced the content of an open access, web-based educational resource. [ABSTRACT FROM AUTHOR]

BACKGROUND Recurrent pregnancy loss (RPL), defined as two or more miscarriages, affects 3–5% of couples trying to establish a family. Despite extensive evaluation, no factor is identified in ∼40% of cases. In this study, we investigated the possibility that submicroscopic chromosomal changes, not detectable by conventional cytogenetic analysis, exist in miscarriages with normal karyotypes (46,XY or 46,XX) from couples with idiopathic RPL. METHODS Array comparative genomic hybridization (array-CGH) was used to assess for DNA copy number variants (CNVs) in 26 miscarriages with normal karyotypes. Parental array-CGH analysis was performed to determine if miscarriage CNVs were de novo or inherited. RESULTS There were 11 unique (previously not described) CNVs, all inherited, identified in 13 miscarriages from 8 couples. The maternal origin of two CNVs was of interest as they involved the imprinted genes TIMP2 and CTNNA3, which are only normally expressed from the maternal copy in the placenta. Two additional cohorts, consisting of 282 women with recurrent miscarriage (RM) and 61 fertile women, were screened for these two CNVs using a Quantitative Multiplex Fluorescent PCR of Short Fragments assay. One woman with RM, but none of the fertile women, carried the CTNNA3-associated CNV. CONCLUSIONS This preliminary study shows that array-CGH is useful for detecting CNVs in cases of RPL. Further investigations of CNVs, particularly those involving genes that are imprinted in placenta, in women with RPL could be worthwhile. [ABSTRACT FROM AUTHOR]

Optimum fluxing, smelting and leaching practices have been determined for maximising the recovery of alumina and soda, but not iron, from a slag produced by oxidative smelting of bauxite residue at 1400°C. The rate and extent of dissolution of alumina and soda increased in a water leach as the CaO/SiO2 ratio in the slag was increased from 0·1 to 2 by the addition of calcium carbonate to the dried bauxite residue. A water leach at 60°C, extracted 55% of the Al and 90% of the Na at 20 wt-% solids and 50 and 75% respectively, at 50 wt-% solids. Liquors containing ∼43 g L–1 Al and Na were obtained from leaches at 50 wt-% solids. By recycling this liquor in two further leaches on fresh slag at 50 wt-% solids, levels of 130 g L–1 Al and 125 g L–1 Na in solution were achieved. At these concentrations of alumina and soda, it is expected that the leach liquor should be suitable for recycling to the Bayer process. The dissolution of the alumina and soda from the slag was shown to be due to the leaching of a sodium aluminium silicate phase considered to be a member of the sodium aluminate–carnegieite solid solution series with a composition of (Na,Ca)2–x(Al,Fe3+)2–xSixO4 (0·2≤x≤0·5). Quantitative analyses in an environmental SEM and the leaching results indicated that the solubility of this phase increased with a decrease in the silicon content of the phase as a result of addition of calcium carbonate to increase the CaO/SiO2 ratio and form larnite (Ca2SiO4). [ABSTRACT FROM AUTHOR]

We have studied the electrical degradation of RF-power PHEMTs by means of in situ 2-D light-emission measurements. Electroluminescence originates in the recombination of holes that have been generated by impact ionization. The local light intensity, thus, maps the electric-field distribution at the drain side of the device. This allows us to probe the uniformity of electrical degradation due to electric-field-driven mechanisms. We find that electrical degradation proceeds in a highly nonuniform manner across the width of the device. In an initial phase, degradation takes place preferentially toward the center of the gate finger. In advanced stages of degradation, the edges of the device degrade at a preferential rate. We identify the origin of this behavior as a small systematic nonuniformity in the recess geometry that impacts the magnitude of the electric field on the drain of the device. Our research suggests that a close examination of the width distribution of electric field in RF-power PHEMTs (and FETs in general) is essential to enhance their long-term reliability. [ABSTRACT FROM PUBLISHER]

OBJECTIVE: To assess the cost-effectiveness of surveillance of Barrett's oesophagus. DESIGN: Cost-utility model. SETTING: UK NHS. PATIENTS: One thousand 55-year-old men with Barrett's oesophagus. INTERVENTION: Surveillance programme: endoscopy and biopsy at 3 yearly intervals for non-dysplastic Barrett's oesophagus; low-grade dysplasia yearly; high grade-dysplasia 3 monthly. OUTCOME MEASURES: Incremental cost-effectiveness ratio, expected value of perfect information. RESULTS: Non-surveillance dominated surveillance (i.e. cost less and conferred more benefit), but there was substantial uncertainty around many of the model inputs. Probabilistic analyses showed that non-surveillance cost less and conferred more benefit in 75% of model runs. Surveillance was cost-effective at usual levels of willingness to pay in 11% of runs. For people with Barrett's oesophagus in England and Wales, a value of pound6.5 million is placed on acquiring perfect information about surveillance of Barrett's oesophagus. CONCLUSIONS: The PenTAG cost-utility model suggests that surveillance programmes do more harm than good. [ABSTRACT FROM AUTHOR]

LY146032, a new antimicrobial agent with activity against Gram-positive cocci, was tested against methicillin-susceptible and methicillin-resistant Staphylococcus aureus, methicillin-susceptible and methicillin-resistant Staph. epidermidis, Staph. saprophyticus, and Streptococcus faecalis. MIC90s in cation-supplemented Mueller Hinton broth by the microdilution broth method were less than 1.0 mg/l for all organisms tested. Increasing or decreasing the inoculum size did not appreciably effect the MIC50 or MIC90 for any organism group nor did decreasing the incubation temperature. The addition of sodium chloride to the test system did not appreciably effect the susceptibility of methicillin-resistant Staph. aureus to LY146032. All organisms were 4 to 32 times more susceptible to LY146032 than to vancomycin. The Staph. aureus had LY146032 susceptibility patterns which were similar to those of teicoplanin and sodium fusidate. LY146032 was 4-16 times more active than teicoplanin against Staph. saprophyticus and Staph. epidermidis while teicoplanin was 8-16 times more active than LY146032 against Str. faecalis. [ABSTRACT FROM AUTHOR]

The in-vitro susceptibility of 14 strains of Legionella pneumophila to 17 anti-microbial agents were determined. The most active antibiotics were cefoxitin, erythromycin and doxycycline while the least active were cephalothin, cefamandole and cefazolin. Subculturing, type of medium and duration of incubation did not alter the effect of the antimicrobial agents. A change in the inoculum size, from 10(4) to 10(6) cfu, increased MICs two- to sixfold. Erythromycin was not synergistic with gentamicin, tobramycin or amikacin. [ABSTRACT FROM AUTHOR]

Strained silicon-on-insulator (SSOI) is a new material system that combines the carrier transport advantages of strained Si with the reduced parasitic capacitance and improved MOSFET scalability of thin-film SOI. We demonstrate fabrication of highly uniform SiGe-free SSOI wafers with 20% Ge equivalent strain and report fully depleted n-MOSFET results. We show that enhanced mobility is maintained in strained Si films transferred directly to SiO[sub 2] from relaxed Si[sub 0.8]Ge[sub 0.2] virtual substrates, even after a generous MOSFET fabrication thermal budget. Further, we find the usable strained-Si thickness of SSOI significantly exceeds the critical thickness of strained Si/SiGe without deleterious leakage current effects typically associated with exceeding this limit. Index Terms—Leakage currents; MOSFETs; silicon alloys; silicon on insulator technology; wafer bonding. [ABSTRACT FROM AUTHOR]

Cyclosporin A is now well established as an effective second-line drug to treat rheumatoid arthritis. In April 1995, the microemulsion-based formulation of cyclosporin (Neoral) was introduced based on its increased bioavailability at 'no extra cost'. There may have been concerns that with increased bioavailability of Neoral, some patients might experience increased toxicity, particularly if transferring from Sandimmun to Neoral at the same dose. We describe our experience of 51 patients treated with Neoral--39 with rheumatoid arthritis, six with psoriatic arthritis and the remainder with a variety of diseases, including Behçet's, systemic lupus erythematosus and juvenile chronic arthritis. All patients continued their other medication including non-steroidal anti-inflammatory drugs and analgesics. Five continued low dose prednisolone (average 7.5 mg per day) all patients were monitored for safety and efficacy throughout their treatment according to standard protocol. Five patients were enrolled in a study of efficacy and safety where the dose of cyclosporin was reduced to 2.5 mg/kg/day at the time of conversion, i.e. to Neoral 2.5 mg/kg/day; 19 patients were converted dose for dose, cyclosporin A dose range 2.5-4 mg/kg/day converted to Neoral dose range 2.5-4 mg/kg/day and 27 patients started Neoral de novo. We conclude that cyclosporin is a useful disease modifying anti-rheumatic agent, and our experience suggests that the new formulation, Neoral, has a similar safety and efficacy profile to the original preparation (Sandimmun). Neoral was relatively easy to manage and we noted a slight reduction in dose when compared to Sandimmun. With dose adjustments over 18 months the mean dose for patients with RA fell from 3.2 to 2.7 mg/kg/day and of the 27 patients starting Neoral de novo only seven required an increased dose above 2.5 mg/kg/day in order to establish efficacy. [ABSTRACT FROM PUBLISHER]