748 research outputs found

    Salting Out Effect of Electrolyte Solutions in The Extraction of Tantalum and Niobium Using Aqueous Biphase System

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    The salting-out effect of various solutions of electrolyte in the extraction of tantalum and niobium using aqueous biphasic system (ABS) was investigated. This was achieved by leaching ball-milled Tantalite ore with mineral acids (H2SO4 and HF) in the ratio of 3:1. The leached liquor was then divided into five parts and each part mixed with ABS formed (e.g. PEG-3350/20wt/wt Na2CO3) for the extraction of tantalum and niobium and then with Na2SO4, K2CO3, K2SO4, KBr, and KI salts in turn. The amount of tantalum pent oxide extracted was determined using X-ray fluorescence method. The results show that the percentage tantalum extracted was in the range of 28.17% to 54.93% i.e. increased in the order KI< KBr < K2CO3< Na2SO4, < K2SO4 with 28.17%, 30.28%, 34.51%, 43.31% and 54.93% respectively; while that of niobium pent oxide increased in the order KI< KBr < K2CO3< Na2SO4, < K2SO4 with 27.3%, 29.35%, 33.78%, 34.64% and 41.98% respectively. In conclusion electrolyte with high ionic charge and hydration radius salts-out Ta2O5 better in the ABS/electrolyte system than those with low values.Keywords: Tantalum, niobium, salting-out, extraction, aqueous biphas

    Thermal and Sedimentation Stress Are Unlikely Causes of Brown Spot Syndrome in the Coral Reef Sponge, Ianthella basta

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    Background: Marine diseases are being increasingly linked to anthropogenic factors including global and local stressors. On the Great Barrier Reef, up to 66% of the Ianthella basta population was recently found to be afflicted by a syndrome characterized by brown spot lesions and necrotic tissue.\ud \ud Methodology/Principal Findings: Manipulative experiments were undertaken to ascertain the role of environmental stressors in this syndrome. Specifically, the effects of elevated temperature and sedimentation on sponge health and symbiont stability in I. basta were examined. Neither elevated temperature nor increased sedimentation were responsible for the brown spot lesions, but sponges exposed to 32°C developed substantial discoloration and deterioration of their tissues, resulting in death after eight days and a higher microbial diversity in those samples. No shifts in the microbial community of I. basta were observed across a latitudinal gradient or with increased sedimentation, with three previously described symbionts dominating the community of all sponges (Alphaproteobacteria, Gammaproteobacteria and Thaumarchaea).\ud \ud Conclusions/Significance: Results from this study highlight the stable microbial community of I. basta and indicate that thermal and sedimentation stress are not responsible for the brown spot lesions currently affecting this abundant and ecologically important sponge species

    The monobloc hydrogel breast implant, experiences and ideas

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    This study is focused on the properties of the monobloc hydrogel (MH) breast implant, which has been around for more than 30 years, and to see how it behaves with regard to health complaints as sometimes seen in some patients who had received silicone gel (SG) breast implants. Patients responded to a questionnaire examining their experience with breast implants. Three groups were included. First, the control group (n = 34) of women without breast implants. Second, a C group of women (n = 42) who began and remained on the MH implant. Third, the B group of women who had their silicone gel implant replaced by the MH implant. In the B1 subgroup (n = 22), a capsulectomy was also performed. In the B2 subgroup (n = 13), the replacement was carried out without a capsulectomy. The C group behaved very much like the control group. The women of the B group experienced an improvement of their complaints and the improvement was even better after a capsulectomy. The only difference between the MH and SG implants is the content of the implant. The satisfaction of women with MH implants is generally high and not or hardly associated with health complaints. In women with SG implants and health complaints, these complaints can be relieved by replacement of the implants by MH implants

    Attitudes and behaviors of Japanese physicians concerning withholding and withdrawal of life-sustaining treatment for end-of-life patients: results from an Internet survey

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    <p>Abstract</p> <p>Background</p> <p>Evidence concerning how Japanese physicians think and behave in specific clinical situations that involve withholding or withdrawal of medical interventions for end-of-life or frail elderly patients is yet insufficient.</p> <p>Methods</p> <p>To analyze decisions and actions concerning the withholding/withdrawal of life-support care by Japanese physicians, we conducted cross-sectional web-based internet survey presenting three scenarios involving an elderly comatose patient following a severe stroke. Volunteer physicians were recruited for the survey through mailing lists and medical journals. The respondents answered questions concerning attitudes and behaviors regarding decision-making for the withholding/withdrawal of life-support care, namely, the initiation/withdrawal of tube feeding and respirator attachment.</p> <p>Results</p> <p>Of the 304 responses analyzed, a majority felt that tube feeding should be initiated in these scenarios. Only 18% felt that a respirator should be attached when the patient had severe pneumonia and respiratory failure. Over half the respondents felt that tube feeding should not be withdrawn when the coma extended beyond 6 months. Only 11% responded that they actually withdrew tube feeding. Half the respondents perceived tube feeding in such a patient as a "life-sustaining treatment," whereas the other half disagreed. Physicians seeking clinical ethics consultation supported the withdrawal of tube feeding (OR, 6.4; 95% CI, 2.5–16.3; P < 0.001).</p> <p>Conclusion</p> <p>Physicians tend to harbor greater negative attitudes toward the withdrawal of life-support care than its withholding. On the other hand, they favor withholding invasive life-sustaining treatments such as the attachment of a respirator over less invasive and long-term treatments such as tube feeding. Discrepancies were demonstrated between attitudes and actual behaviors. Physicians may need systematic support for appropriate decision-making for end-of-life care.</p

    Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study

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    ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area

    Blood volume measurement with indocyanine green pulse spectrophotometry: dose and site of dye administration

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    (1) To determine the optimal administration site and dose of indocyanine green (ICG) for blood volume measurement using pulse spectrophotometry, (2) to assess the variation in repeated blood volume measurements for patients after subarachnoid hemorrhage and (3) to evaluate the safety and efficacy of this technique in patients who were treated for an intracranial aneurysm. Four repeated measurements of blood volume (BV) were performed in random order of bolus dose (10 mg or 25 mg ICG) and venous administration site (peripheral or central) in eight patients admitted for treatment of an intracranial aneurysm. Another five patients with subarachnoid hemorrhage underwent three repeated BV measurements with 25 mg ICG at the same administration site to assess the coefficient of variation. The mean +/- SD in BV was 4.38 +/- 0.88 l (n = 25) and 4.69 +/- 1.11 l (n = 26) for 10 mg and 25 mg ICG, respectively. The mean +/- SD in BV was 4.59 +/- 1.15 l (n = 26) and 4.48 +/- 0.86 l (n = 25) for central and peripheral administration, respectively. No significant difference was found. The coefficient of variance of BV measurement with 25 mg of ICG was 7.5% (95% CI: 3-12%). There is no significant difference between intravenous administration of either 10 or 25 mg ICG, and this can be injected through either a peripheral or central venous catheter. The 7.5% coefficient of variation in BV measurements determines the detectable differences using ICG pulse spectrophotometr
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