60 research outputs found

    Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase

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    Current methodologies for the extraction of tantalum and niobium pose a serious threat to human beings and the environment due to the use of hydrofluoric acid (HF). Niobium and tantalum metal powders and pentoxides are widely used for energy efficient devices and components. However, the current processing methods for niobium and tantalum metals and oxides are energy inefficient. This dichotomy between materials use for energy applications and their inefficient processing is the main motivation for exploring a new methodology for the extraction of these two oxides, investigating the microwave absorption properties of the reaction products formed during the alkali roasting of niobium-tantalum bearing minerals with sodium bicarbonate. The experimental findings from dielectric measurement at elevated temperatures demonstrate an exponential increase in the values of the dielectric properties as a result of the formation of NaNbO3-NaTaO3solid solutions at temperatures above 700 °C. The investigation of the evolution of the dielectric properties during the roasting reaction is a key feature in underpinning the mechanism for designing a new microwave assisted high-temperature process for the selective separation of niobium and tantalum oxides from the remainder mineral crystalline lattice

    Basic aspects of the pharmacodynamics of tolperisone, a widely applicable centrally acting muscle relaxant

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    Tolperisone (2-methyl-1-(4-methylphenyl)-3-piperidin-1-ylpropan-1-one hydro-chloride) was introduced in the clinical practice more than forty years ago and is still evaluated as a widely applicable compound in pathologically elevated skeletal muscle tone (spasticity) and related pains of different origin. In the present review, basic pharmacodynamic effects measured on whole animals, analyses of its actions on cell and tissue preparations and molecular mechanism of action on sodium and calcium channels are summarized as recently significantly new data were reported

    Gender Gap in Parental Leave Intentions: Evidence from 37 Countries

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    Despite global commitments and efforts, a gender-based division of paid and unpaid work persists. To identify how psychological factors, national policies, and the broader sociocultural context contribute to this inequality, we assessed parental-leave intentions in young adults (18–30 years old) planning to have children (N = 13,942; 8,880 identified as women; 5,062 identified as men) across 37 countries that varied in parental-leave policies and societal gender equality. In all countries, women intended to take longer leave than men. National parental-leave policies and women’s political representation partially explained cross-national variations in the gender gap. Gender gaps in leave intentions were paradoxically larger in countries with more gender-egalitarian parental-leave policies (i.e., longer leave available to both fathers and mothers). Interestingly, this cross-national variation in the gender gap was driven by cross-national variations in women’s (rather than men’s) leave intentions. Financially generous leave and gender-egalitarian policies (linked to men’s higher uptake in prior research) were not associated with leave intentions in men. Rather, men’s leave intentions were related to their individual gender attitudes. Leave intentions were inversely related to career ambitions. The potential for existing policies to foster gender equality in paid and unpaid work is discussed

    Gender gap in parental leave intentions: Evidence from 37 countries

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    This is the final version. Available from Wiley via the DOI in this record. Despite global commitments and efforts, a gender-based division of paid and unpaid work persists. To identify how psychological factors, national policies, and the broader sociocultural context contribute to this inequality, we assessed parental-leave intentions in young adults (18–30years old) planning to have children (N = 13,942; 8,880 identified as women; 5,062 identified as men) across 37 countries that varied in parental-leave policies and societal gender equality. In all countries, women intended to take longer leave than men. National parental-leave policies and women’s political representation partially explained cross-national variations in the gender gap. Gender gaps in leave intentions were paradoxically larger in countries with more gender-egalitarian parental-leave policies (i.e., longer leave available to both fathers and mothers). Interestingly, this cross-national variation in the gender gap was driven by cross-national variations in women’s (rather than men’s) leave intentions. Financially generous leave and gender-egalitarian policies (linked to men’s higher uptake in prior research) were not associated with leave intentions in men. Rather, men’s leave intentions were related to their individual gender attitudes. Leave intentions were inversely related to career ambitions. The potential for existing policies to foster gender equality in paid and unpaid work is discussed.SSHRC Insight Development GrantSSHRC Insight GrantEconomic and Social Research CouncilState Research AgencyGuangdong 13th-five Philosophy and Social Science Planning ProjectNational Natural Science Foundation of ChinaSwiss National Science FoundationSwiss National Science FoundationCenter for Social Conflict and Cohesion StudiesCenter for Intercultural and Indigenous ResearchSSHRC Postdoctoral FellowshipSlovak Research and Development AgencySwiss National Science FoundationCanada Research ChairsSocial Sciences and Humanities Research Council of CanadaOntario Ministry of Research and InnovationHSE University, RFFaculty of Arts, Masaryk Universit

    Prevention of Jarisch-Herxheimer reactions by treatment with antibodies against tumor necrosis factor alpha.

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    BACKGROUND: In patients with louse-borne relapsing fever (Borrelia recurrentis infection), antimicrobial treatment is often followed by sudden fever, rigors, and persistent hypotension (Jarisch-Herxheimer reactions) that are associated with increases in plasma concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin-6, and interleukin-8. We attempted to determine whether sheep polyclonal Fab antibody fragments against TNF-alpha (anti-TNF-alpha Fab) could suppress the Jarisch-Herxheimer reaction. METHODS: We conducted a randomized, double-blind, placebo-controlled trial in 49 patients with proven louse-borne relapsing fever. Immediately before the intramuscular injection of penicillin, the patients received an intravenous infusion of either anti-TNF-alpha Fab or a control solution. RESULTS: Ten of the 20 patients given anti-TNF-alpha Fab had Jarisch-Herxheimer reactions with rigors, as compared with 26 of the 29 control patients (P = 0.006). The controls had significantly greater mean maximal increases in temperature (1.5 vs. 0.8 degrees C, P < 0.001), pulse rate (31 vs. 13 per minute, P < 0.001), and systolic blood pressure (25 vs. 15 mm Hg, P < 0.003), as well as higher mean peak plasma concentrations of interleukin-6 (50 vs. 17 micrograms per liter) and interleukin-8 (2000 vs 205 ng per liter) (P < 0.001 for both comparisons). Levels of TNF-alpha were undetectable after treatment with anti-TNF-alpha Fab. CONCLUSIONS: Pretreatment with sheep anti-TNF-alpha Fab suppresses Jarisch-Herxheimer reactions that occur after penicillin treatment for louse-borne relapsing fever, reduces the associated increases in plasma concentrations of interleukin-6 and interleukin-8, and may be useful in other forms of sepsis

    The effect of antibody against TNF alpha on cytokine response in Jarisch-Herxheimer reactions of louse-borne relapsing fever.

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    Severe Jarisch Herxheimer reaction (J-HR) precipitated by antibiotic treatment of louse-borne relapsing fever (LBRF) is associated with a transient, marked rise in circulating tumour necrosis factor alpha (TNF alpha), interleukin 6 (IL-6) and interleukin 8 (IL-8). Ovine polyclonal anti-TNF alpha antibody fragments (Fab) were used in a randomized double blind placebo controlled trial in an attempt to prevent this reaction. Within 4 h after penicillin, in controls (n = 29), a several-fold rise in cytokines occurred, concomitant with a fall in spirochaetes and maximal clinical manifestations of the J-HR. An intravenous infusion of anti-TNF alpha Fab, 30 min before penicillin in 20 patients reduced peak plasma levels of IL-6 and IL-8 (but not IL-1 beta) compared with controls (p = 0.01 and < 0.001, respectively) and the incidence of the J-HR, indicating some neutralization of TNF alpha. An apparent fall in TNF alpha reflected interference of anti-TNF alpha in the immunoassay
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