2,649 research outputs found

    Chromium recovery by membranes for process reuse in the tannery industry

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    Leather tanning is a wide common industry all over the world. In leather processing, water is one of the most important medium, almost 40-45 L water kg-1 raw-hide or skin is used by tanneries for processing finished leathers. The composition of tannery wastewater presents considerable dissimilarities in the concentration range of pollutants both of inorganic (chlorides, with concentration ranging from several hundred to over 10,000 mg L-1 Cl–; sulphate (VI), ammonium ions and sulphide ions, exhibiting concentration that ranges from tens to several hundred mg L-1) and organic (the COD value is usually several thousand mg L-1 O2). Throughout the years, many conventional processes have been carried out to treat wastewater from tannery industry: unfortunately, in this case, biological treatment methods give rise to an excessive production of sludge, whereas physical and chemical methods are too expensive in terms of energy and reagent costs. In this work, a membrane process based on NF membrane modules was adopted to treat the tannery feedstock after primary conventional treatment. In a first step, the determination of all boundary flux parameters, in order to inhibit severe fouling formation during operation, were performed. After this, experimental work was carried out to validate the approach. The target of water purification was reached, that is the legal discharge to municipal sewer system in Italy of 90% of the initial wastewater stream volume. This allows having an immediate cost saving of 21%. Moreover, the developed process leads to a second benefit, that is the production of 5% of the initial volume as a highly chromium-rich concentrate at no cost suitable to tannery process recycle and reuse. In this case, cost saving rates exceeds 40%. At the end, scale-up of the investigated process will be discussed from technical and economic point of view

    Naloxone Administration Route in Opioid Overdose: A Review of Vermont EMS Data

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    Objective: Emergency Medical System (EMS) personnel administer the direct opioid antagonist naloxone in cases of opioid overdose via intramuscular (IM), intravenous (IV), subcutaneous (SQ), intraosseous (IO), or intranasal (IN) routes. Some early studies suggest that the intranasal route of administration is of similar effectiveness to injectable routes. The main objective of our study was to compare the efficacy of intravenous and intraosseous (IV/IO) routes of naloxone administration to the intranasal (IN) route in suspected opioid overdoses in Vermont. Methods: We reviewed retrospective data from Vermont EMS Statewide Incident Reporting Network (SIREN) between April 2014 and August 2016. We included all patients that were entered into SIREN and administered naloxone during the study period. Predictor variables were route of administration, medication dosage, crew member level, and cardiac arrest (yes or no). We conducted a binary logistic regression in SPSS to predict improvement in patient condition. Results: Our sample consisted of 1139 cases of first-dose naloxone administration. 1076 cases contained sufficient data to be analyzed. Patients who experienced a cardiac arrest were less likely to respond to naloxone (OR 10.8, 95% CI (5.908-19.694)). Route of administration, crew member level, and dosage (in the normal therapeutic range of 0.1-2mg) did not have a statistically significant effect on patient response to naloxone. Conclusions: Our findings, in conjunction with other recent research, suggest that intranasal administration is a safe and effective route when compared with intravenous and intraosseous routes. Intranasal administration has several distinct advantages over injectable routes, including the potential to reduce the risk of needle-stick injuries and blood-borne pathogen transmissions and to be handled by individuals with less medical training. In cases of cardiac arrest, we recommend that providers focus on treatments with proven benefit, including CPR and proper ventilation and oxygenation

    Behavior of N-Doped TiO2 and N-Doped ZnO in Photocatalytic Azo Dye Degradation under UV and Visible Light Irradiation: A Preliminary Investigation

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    Abstract: N-doped TiO2 (N-TiO2) and N-doped ZnO (N-ZnO) were synthesized utilizing ammonia as a dopant source. The chemico-physical characteristics of synthesized samples were studied by Raman spectroscopy, X-ray diffraction, SEM analysis, N2 adsorption–desorption at −196 ◦C, and diffuse reflectance spectroscopy. Compared to undoped samples, the introduction of nitrogen in the semiconductor lattice resulted in a shift of band-gap energy to a lower value: 3.0 eV for N-ZnO and 2.35 eV for N-TiO2. The photocatalysts were tested for the degradation of Eriochrome Black T (EBT), which was selected as a model azo dye. Both N-doped semiconductors evidenced an improvement in photocatalytic activity under visible light irradiation (62% and 20% EBT discoloration for N-TiO2 and N-ZnO, respectively) in comparison with the undoped samples, which were inactive in the presence of visible light. Different behavior was observed under UV irradiation. Whereas N-TiO2 was more photoactive than commercial undoped TiO2, the introduction of nitrogen in ZnO wurtzite resulted in a drastic reduction in photocatalytic activity, with only 45% EBT discoloration compared to total color removal obtained with the commercial ZnO sample, suggesting intrinsic limitations for doping of this class of semiconductors

    Differences and similarities between SARS-CoV and SARS-CoV-2: spike receptor-binding domain recognition and host cell infection with support of cellular serine proteases

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    Novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) became pandemic by the end of March 2020. In contrast to the 2002–2003 SARS-CoV outbreak, which had a higher pathogenicity and lead to higher mortality rates, SARSCoV-2 infection appears to be much more contagious. Moreover, many SARS-CoV-2 infected patients are reported to develop low-titer neutralizing antibody and usually suffer prolonged illness, suggesting a more effective SARS-CoV-2 immune surveillance evasion than SARS-CoV. This paper summarizes the current state of art about the differences and similarities between the pathogenesis of the two coronaviruses, focusing on receptor binding domain, host cell entry and protease activation. Such differences may provide insight into possible intervention strategies to fight the pandemic

    Foot posture and classification of the plantar arch among adolescent wearers and non-wearers of high-heeled shoes

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    OBJETIVOS: Correlacionar a postura dos pés com o arco plantar de adolescentes usuárias e não usuárias de calçados de salto alto. MÉTODOS: Foram selecionadas 36 adolescentes, 16 no grupo de não usuárias e 20 no grupo de usuárias, com idade entre 13 e 20 anos. A postura do pé foi analisada por fotos nas condições descalça e com calçado de salto alto tipo Anabella, previamente padronizado, após terem permanecido com ele por uma hora. Sua análise foi realizada pelo software SAPO. A impressão plantar foi realizada descalça e, a partir dela, calculado o Índice de Chipaux - Smirak para classificação do arco plantar. Para análise estatística, utilizou-se o teste t pareado para verificar igualdade entre lados direito e esquerdo. Foi realizado o teste de aderência Shapiro Wilk e, então, a análise inferencial por meio dos testes não paramétricos de Wilcoxon, o teste de Mann-Whitney e a correlação de Spearman. O nível de significância adotado foi de 0,05. RESULTADOS: Não foi encontrada correlação entre o tipo de arco plantar e a postura do pé das adolescentes estudadas. Porém, o ângulo do retropé se mostrou significativamente diferente, apresentando varo de retropé após a colocação do calçado em ambos os grupos, e o arco plantar do grupo de usuárias apresentou valores menores quanto ao Índice Chipaux - Smirak. CONCLUSÕES: Não existe correlação entre a postura do pé e o tipo de arco plantar, embora essas variáveis tenham sofrido influência do calçado de salto alto. Artigo registrado na Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número ACTRN12608000300370.OBJECTIVES: To investigate the relationship between foot posture and plantar arch among adolescent wearers and non-wearers of high-heeled shoes. METHODS: Thirty-six female adolescents aged 13 to 20 years were selected and grouped as 16 high-heel non-wearers and 20 high-heel wearers. Foot posture was analyzed using photos, firstly barefoot and, secondly, after wearing previously standardized high-heeled platform shoes for an hour. The analysis was performed using the software SAPo. Barefoot impressions were taken, and the Chipaux-Smirak Index was calculated to classify the plantar arch of the foot. For statistical analyses, the paired t test was used to investigate equality between the right and left sides. The Shapiro-Wilk adherence test was performed, followed by inferential analysis using the non-parametric Wilcoxon test, the Mann-Whitney test and Spearman's correlation coefficient. The significance level used was 0.05. RESULTS: There was no correlation between the type of plantar arch and foot posture among the female adolescents studied. However, the rearfoot angle was significantly different, with rearfoot varus after wearing the shoes in both groups. The plantar arch in the wearers group presented smaller values for the Chipaux-Smirak Index. CONCLUSIONS: There is no correlation between foot posture and the type of plantar arch, although these variables are influenced by high-heeled shoes. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12608000300370

    Foot posture and classification of the plantar arch among adolescent wearers and non-wearers of high-heeled shoes

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    OBJETIVOS: Correlacionar a postura dos pés com o arco plantar de adolescentes usuárias e não usuárias de calçados de salto alto. MÉTODOS: Foram selecionadas 36 adolescentes, 16 no grupo de não usuárias e 20 no grupo de usuárias, com idade entre 13 e 20 anos. A postura do pé foi analisada por fotos nas condições descalça e com calçado de salto alto tipo Anabella, previamente padronizado, após terem permanecido com ele por uma hora. Sua análise foi realizada pelo software SAPO. A impressão plantar foi realizada descalça e, a partir dela, calculado o Índice de Chipaux - Smirak para classificação do arco plantar. Para análise estatística, utilizou-se o teste t pareado para verificar igualdade entre lados direito e esquerdo. Foi realizado o teste de aderência Shapiro Wilk e, então, a análise inferencial por meio dos testes não paramétricos de Wilcoxon, o teste de Mann-Whitney e a correlação de Spearman. O nível de significância adotado foi de 0,05. RESULTADOS: Não foi encontrada correlação entre o tipo de arco plantar e a postura do pé das adolescentes estudadas. Porém, o ângulo do retropé se mostrou significativamente diferente, apresentando varo de retropé após a colocação do calçado em ambos os grupos, e o arco plantar do grupo de usuárias apresentou valores menores quanto ao Índice Chipaux - Smirak. CONCLUSÕES: Não existe correlação entre a postura do pé e o tipo de arco plantar, embora essas variáveis tenham sofrido influência do calçado de salto alto. Artigo registrado na Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número ACTRN12608000300370.OBJECTIVES: To investigate the relationship between foot posture and plantar arch among adolescent wearers and non-wearers of high-heeled shoes. METHODS: Thirty-six female adolescents aged 13 to 20 years were selected and grouped as 16 high-heel non-wearers and 20 high-heel wearers. Foot posture was analyzed using photos, firstly barefoot and, secondly, after wearing previously standardized high-heeled platform shoes for an hour. The analysis was performed using the software SAPo. Barefoot impressions were taken, and the Chipaux-Smirak Index was calculated to classify the plantar arch of the foot. For statistical analyses, the paired t test was used to investigate equality between the right and left sides. The Shapiro-Wilk adherence test was performed, followed by inferential analysis using the non-parametric Wilcoxon test, the Mann-Whitney test and Spearman's correlation coefficient. The significance level used was 0.05. RESULTS: There was no correlation between the type of plantar arch and foot posture among the female adolescents studied. However, the rearfoot angle was significantly different, with rearfoot varus after wearing the shoes in both groups. The plantar arch in the wearers group presented smaller values for the Chipaux-Smirak Index. CONCLUSIONS: There is no correlation between foot posture and the type of plantar arch, although these variables are influenced by high-heeled shoes. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12608000300370

    Rare earth oxides in zirconium dioxide: How to turn a wide band gap metal oxide into a visible light active photocatalyst

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    In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% molar (rare earth oxide over zirconium dioxide) respectively. The samples have been studied via X-ray Diffraction measurements for the structural characterization. UV visible diffuse reflectance was used for the optical analysis, Brunauer-Emmett-Teller (BET) model for the measurement of the surface area. Finally the samples have been analysed via electron paramagnetic resonance (EPR) for the electronic characterization. Then we tested the new synthetized materials to determine their photo catalytic activity in the reaction of degradation of methylene blue performed under irradiation by diodes (LEDs) emitting exclusively visible light. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved

    Relationship of national institutes of health stroke scale to 30-day mortality in medicare beneficiaries with acute ischemic stroke.

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    BackgroundThe National Institutes of Health Stroke Scale (NIHSS), a well-validated tool for assessing initial stroke severity, has previously been shown to be associated with mortality in acute ischemic stroke. However, the relationship, optimal categorization, and risk discrimination with the NIHSS for predicting 30-day mortality among Medicare beneficiaries with acute ischemic stroke has not been well studied.Methods and resultsWe analyzed data from 33102 fee-for-service Medicare beneficiaries treated at 404 Get With The Guidelines-Stroke hospitals between April 2003 and December 2006 with NIHSS documented. The 30-day mortality rate by NIHSS as a continuous variable and by risk-tree determined or prespecified categories were analyzed, with discrimination of risk quantified by the c-statistic. In this cohort, mean age was 79.0 years and 58% were female. The median NIHSS score was 5 (25th to 75th percentile 2 to 12). There were 4496 deaths in the first 30 days (13.6%). There was a strong graded relation between increasing NIHSS score and higher 30-day mortality. The 30-day mortality rates for acute ischemic stroke by NIHSS categories were as follows: 0 to 7, 4.2%; 8 to 13, 13.9%; 14 to 21, 31.6%; 22 to 42, 53.5%. A model with NIHSS alone provided excellent discrimination whether included as a continuous variable (c-statistic 0.82 [0.81 to 0.83]), 4 categories (c-statistic 0.80 [0.79 to 0.80]), or 3 categories (c-statistic 0.79 [0.78 to 0.79]).ConclusionsThe NIHSS provides substantial prognostic information regarding 30-day mortality risk in Medicare beneficiaries with acute ischemic stroke. This index of stroke severity is a very strong discriminator of mortality risk, even in the absence of other clinical information, whether used as a continuous or categorical risk determinant. (J Am Heart Assoc. 2012;1:42-50.)
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