50 research outputs found

    Toward a more sustainable mining future with electrokinetic in situ leaching

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    This is the final version. Available on open access from AAAS via the DOI in this recordData and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.Metals are currently almost exclusively extracted from their ore via physical excavation. This energy-intensive process dictates that metal mining remains among the foremost CO2 emitters and mine waste is the single largest waste form by mass. We propose a new approach, electrokinetic in situ leaching (EK-ISL), and demonstrate its applicability for a Cu-bearing sulfidic porphyry ore. In laboratory-scale experiments, Cu recovery was rapid (up to 57 weight % after 94 days) despite low ore hydraulic conductivity (permeability = 6.1 mD; porosity = 10.6%). Multiphysics numerical model simulations confirm the feasibility of EK-ISL at the field scale. This new approach to mining is therefore poised to spearhead a new paradigm of metal recovery from currently inaccessible ore bodies with a markedly reduced environmental footprint.Minerals Research Institute of Western Australia (MRIWA

    Scrapie-Specific Pathology of Sheep Lymphoid Tissues

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    Transmissible spongiform encephalopathies (TSEs) or prion diseases often result in accumulation of disease-associated PrP (PrPd) in the lymphoreticular system (LRS), specifically in association with follicular dendritic cells (FDCs) and tingible body macrophages (TBMs) of secondary follicles. We studied the effects of sheep scrapie on lymphoid tissue in tonsils and lymph nodes by light and electron microscopy. FDCs of sheep were grouped according to morphology as immature, mature or regressing. Scrapie was associated with FDC dendrite hypertrophy and electron dense deposit or vesicles. PrPd was located using immunogold labelling at the plasmalemma of FDC dendrites and, infrequently, mature B cells. Abnormal electron dense deposits surrounding FDC dendrites were identified as immunoglobulins suggesting that excess immune complexes are retained and are indicative of an FDC dysfunction. Within scrapie-affected lymph nodes, macrophages outside the follicle and a proportion of germinal centre TBMs accumulated PrPd within endosomes and lysosomes. In addition, TBMs showed PrPd in association with the cell membrane, non-coated pits and vesicles, and also with discrete, large and random endoplasmic reticulum networks, which co-localised with ubiquitin. These observations suggest that PrPd is internalised via the caveolin-mediated pathway, and causes an abnormal disease-related alteration in endoplasmic reticulum structure. In contrast to current dogma, this study shows that sheep scrapie is associated with cytopathology of germinal centres, which we attribute to abnormal antigen complex trapping by FDCs and abnormal endocytic events in TBMs. The nature of the sub-cellular changes in FDCs and TBMs differs from those of scrapie infected neurones and glial cells suggesting that different PrPd/cell membrane interactions occur in different cell types

    Practical issues in early switching from intravenous to oral antibiotic therapy in children with uncomplicated acute hematogenous osteomyelitis: Results from an italian survey

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    Background: The European Society of Pediatric Infectious Diseases (ESPID) guidelines for acute hematogenous osteomyelitis (AHOM) have been published recently. In uncomplicated cases, an early (2-4 days) switch to oral empirical therapy, preferentially with flucloxacillin, is recommended in low methicillin-resistant Staphylococcus aureus settings. We conducted a survey with the aim of evaluating the behaviors of Italian pediatricians at this regard. Methods: An open-ended questionnaire investigating the empiric therapy adopted in uncomplicatedAHOMchildren according to age was sent by email to 31 Italian pediatric clinics taking care of children with infectious diseases, and results were analyzed. Results: The preferred intravenous (IV) regimen was a penicillin plus an aminoglycoside (n = 10; 32.3%) in children aged <3 months, and a combination of a third-generation cephalosporin plus oxacillin (n = 7; 22.6%), or oxacillin alone (n = 6; 19.4%) in those 653 months. In every age class, amoxicillin-clavulanate was the first-choice oral antibiotic. Other antibiotics largely used orally included clindamycin, rifampicin, and trimethoprim/sulfamethoxazole. Flucloxacillin was never prescribed. Only 3 centers switched to oral therapy within 7 days in children 653 months of age. The most commonly reported reason influencing the time to switch to oral therapy concerned caregivers\u2019 adherence to oral therapy. Conclusion: Adherence to guidelines was poor, and early transition to oral therapy in the clinical practice was rarely adopted. Given the large use of potentially effective, but poorly studied, oral antibiotics such as amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, and rifampicin, our data may stimulate further studies of this regard

    Acute idiopathic scrotal edema in children

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    a case of acute idiopathic scrotal edem

    Cardiomyopathy and pericardial effusion in a 7 year-old boy with beta-thalassaemia major, severe primary hypothyroidism and hypoparathyroidism due to iron overload.

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    The primary cause of cardiac dysfunction in thalassemia is believed to be myocardial iron overload. Besides iron, other factors may play a role in the impairment of myocardial contractility, including prolonged heart tissue hypoxia, pericardial involvement, arrhythmias, endocrine complications and vitamin D deficiency. We present the case of a 7 year-old boy with ?-thalassaemia major and cardiac dysfunction, pericardial effusion and associated endocrinopathies. His serum thyrotropin (TSH) level was increased, and total and free thyroxine (FT4) were low. In addition, biochemical results and serum PTH level were compatible with a diagnosis of hypoparathyroidism. Other laboratory findings were not consistent with rheumatic heart disease, viral myocarditis or autoimmune disease. The child was treated with digoxin, diuretics, oral calcium, vitamin D, L-thyroxine (25 microg daily, which was later gradually increased) and subcutaneous iron chelation therapy (45 mg/kg, six days/week). The patient was discharged from our Unit after 7 days and within 3 months he had appreciable myocardial improvement and disappearance of the pericardial effusion

    Papillary thyroid cancer in thalassaemia.

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    Thyroid cancer is the most frequent endocrine neoplasm in the general population. Its incidence is 5-10/100,000 per year, with an annual death rate of 0.2-1.2/100,000 in men and 0.4-2.8/100,000 in women. In thalassaemia patients the frequency of this disease is unknown. In this paper we describe five cases of papillary thyroid cancer in thalassaemia patients followed at the Day Hospital for Thalassaemia and Haemoglobinopathies, in Ferrara, Italy. We consider the possible key role of iron as a carcinogenic agent and we also discuss the practical implications of our clinical observations

    Dynamic and reversible restructuring of the ER induced by PDMP in cultured cells

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    In many cells, the endoplasmic reticulum (ER) contains segregated smooth and rough domains, but the mechanism of this segregation is unclear. Here, we used a HeLa cell line, inducibly expressing a GFP fusion protein [GFP-b(5)tail] anchored to the ER membrane, as a tool to investigate factors influencing ER organisation. Induction of GFP-b(5)tail expression caused proliferation of the ER, but its normal branching polygonal meshwork architecture was maintained. Experiments designed to test the effects of drugs that alter ceramide levels revealed that treatment of these cells with Phenyl-2-decanoyl-amino-3-morpholino-1-propanol-hydrocholride (PDMP) generated patches of segregated smooth ER, organised as a random tubular network, which rapidly dispersed after removal of the drug. The effect of PDMP was independent of its activity as sphingolipid synthesis inhibitor, but could be partially reversed by a membrane-permeant Ca(2+) chelator. Although the smooth ER patches maintained connectivity with the remaining ER, they appeared to represent distinct domains differing in protein and lipid composition from the remaining ER. PDMP did not cause detachment of membrane-bound ribosomes, indicating that smooth ER patch generation was due to a reorganisation of pre-existing ribosome-free areas. Our results demonstrate a dynamic relationship between smooth and rough ER and have implications for the mechanisms regulating ER architecture

    Infrared thermography in children: A reliable tool for differential diagnosis of peripheral microvascular dysfunction and Raynaud's phenomenon?

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    Background: Infrared Thermography (IRT) has been used for over 30 years in the assessment of Raynaud Phenomenon (RP) and other peripheral microvascular dysfunctions in adults but, to date, very little experience is available on its use in children for this purpose. The first aim of the study was to assess reproducibility of thermographic examination after cold exposure by comparing inter-observer agreement in thermal imaging interpretation. The secondary aim was to evaluate whether IRT is reliable to diagnose and differentiate peripheral circulation disturbances in children. Methods: Children with clinical diagnosis of primary Raynaud's phenomenon (PRP), secondary RP (SRP), acrocyanosis (AC) and age-matched controls underwent sequential measurements of skin temperature at distal interphalangeal (DIP) and metacarpophalangeal (MCP) joints with IRT at baseline and for 10 min after cold challenge test. Intraclass correlation coefficient (ICC) was calculated for inter-rater reliability in IRT interpretation, then temperature variations at MCP and DIP joints and the distal-dorsal difference (DDD) were analysed. Results: Fourteen PRP, 16 SRP, 14 AC and 15 controls entered the study. ICC showed excellent agreement (> 0.93) for DIPs and MCPs in 192 measures for each subject. Patients with PRP, SRP and acrocyanosis showed significantly slower recovery at MCPs (p < 0.05) and at DIPs (p < 0.001) than controls. At baseline, higher temperature at DIPs and lower at MCPs was observed in PRP compared with SRP with significantly lower DDD (p < 0.001). Differently from AC, both PRP and SRP showed gain of temperature at DIPs and less at MCPs after cold challenge. PRP but not SRP patients returned to DIPs basal temperature by the end of re-warming time. Analysis of DDD confirmed that controls and PRP, SRP and AC patients significantly differed in fingers recovery pattern (p < 0.05). Conclusion: IRT appears reliable and reproducible in identifying children with peripheral microvascular disturbances. Our results show that IRT examination pointed out that PRP, SRP and AC patients present significant differences in basal extremities temperature and in re-warming pattern after cold challenge therefore IRT can be suggested as an objective tool for diagnosis and monitoring of disease
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