Frozen mitochondria as rapid water quality bioassay

A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at 22 °C, instead of 80 °C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark elec- trode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen con- sumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excelâ Macro, identified the break-point in the oxygen con- sumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests

Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest

Abstract In this work we studied the reactivity of the Trifuoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifuoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1 h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383 K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifuoroacetate of the hydroxylamine with a modifed nitric acid hydrogenation reactions was verifed, too. Reuse of solvent and trifuoroacetic acid is easily achieved by distillation

The pyrolysis and gasification pathways of automotive shredder residue targeting the production of fuels and chemicals

Automotive shredder residue (ASR), also referred to as car fluff, is the 15-25% of end-of-life vehicle’s mass remaining after de-pollution, dismantling, shredding of the hulk and removal of metals from the shredded fraction. ASR typically consists of metals, plastics, rubber, textile, wood and glass, and is commonly landfilled. The use of ASR as a fuel in incineration processes is controversial since toxic pollutants can be generated as by-products if operational conditions and gas cleaning systems are not carefully controlled. Thermochemical treatment of ASR consists of advanced technology processes that convert ASR components liable to decomposition under the application of heat into liquids and/or gases and a solid residue containing metals. Within the thermochemical treatment options for ASR, pyrolysis and gasification are generally considered as the emerging technologies. The pyrolysis process uses medium temperatures (400-600°C) and an oxygen-free environment to decompose ASR chemically, thus producing minimum emissions and allowing metals to be recovered. Gasification is operated at higher temperatures (>700-800°C) and typically uses air as a gasification agent, which raises some issues in terms of emissions. Lab and pilot-scale plants fed with ASR have been built using both technologies, also considering a combination of them. The aim of this paper is the identification of the best conversion pathway for the production of transportation fuels, aviation fuels or chemicals (hydrogen, methanol, etc.) from ASR. The intermediate products from gasification and pyrolysis are used as feedstock in secondary processes for the production of the final products. The heterogeneous and complex composition of ASR raises several challenges upon its thermochemical treatment, so that the second step of the conversion process is typically not even addressed. Instead, this further step is fundamental to obtain some valuable products that can directly replace fossil derived fuels or chemicals. The updated picture presented in this work should help identify the main advantages and drawbacks of the pyrolysis and gasification processes when considered part of an overall ASR to fuels or chemicals plant

INFLUENZA DELLA MODIFICA ALLO STRONZIO E DELLA CONDIZIONE DI SOLIDIFICAZIONE SULLA MICROSTRUTTURA IN LEGHE ALLUMINIO-SILICIO DA FONDERIA

L’elevata velocità di solidificazione così come il trattamento di modifica allo stronzio (Sr) svolgono un ruolo fondamentale nella fonderia d’alluminio, intervenendo sulla scala microstrutturale nonché sulla morfologia e distribuzione del silicio all’interno dell’eutettico. In questo studio sono analizzati in maniera sistematica gli effetti della condizione di solidificazione e della modifica allo Sr sul livello di modifica del silicio eutettico in leghe AlSiMgTi da fonderia. Sono state predisposte differenti configurazioni di analisi termica al fine di variare la velocità di raffreddamento; i campioni ottenuti sono quindi stati analizzati metallograficamente. Gli effetti di un trattamento di modifica al sodio (Na) sono stati infine studiati sulle medesime leghe a titolo di confronto. In condizioni di lento raffreddamento, il livello di modifica in lega EN AB-42000 migliora con l’aumentare del contenuto di Sr e raggiunge valori ottimali quando la quantità di quello si situa nell’intervallo di 100-200 ppm. Simili risultati non sono ottenuti in leghe EN AB-43300 e 44000, la cui microstruttura, nonostante un contenuto più elevato di Sr (400-500 ppm), risulta solo parzialmente modificata. La modifica al Na ha mostrato il miglior grado di efficienza per tutte le leghe analizzate in condizioni di lento raffreddamento. La temperatura eutettica nelle leghe ad elevato tenore di silicio, modificate con 400 ppm di Sr, diminuisce significativamente incrementando la velocità di solidificazione, con un miglioramento del livello di modifica. Considerando i risultati ottenuti dall’analisi termica, l’efficacia del trattamento di modifica al Na e allo Sr è stata studiata su alcuni getti di ruote, colati in gravità con leghe EN AB-42000 e 44000

Frozen mitochondria as rapid water quality bioassay

A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at 22 °C, instead of 80 °C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark elec- trode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen con- sumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excelâ Macro, identified the break-point in the oxygen con- sumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests

Improvement on frozen mitochondria bioassay: a methodological remark.

The protocol for the bioassay with the mitochondria of beef heart frozen at -22 °C, (developed by Iero, Manente, Bragadin and Perin, in Chemosphere, 52, 2003) requires that the reaction cell is thermostatically controlled at 25 °C. This value was chosen because it is used as a reference for the state environmental standard (Standard Ambient Temperature and Pressure, SATP). The choice is not, therefore, been supported by assessments on the effectiveness of the test at this temperature, but was dictated by the practice of reporting results to a standard temperature value. Finally, it was decided to make a comparison between the working temperature of 25 °C and the 37 °C one, chosen as close to cattle body temperature (estimated to be 38.6 °C), then "normal" working temperature for mitochondria extracted from heart

Are Induced Pluripotent Stem Cells a Step towards Modeling Pediatric Leukemias?

Despite enormous improvements in pre-clinical and clinical research, acute leukemia still represents an open challenge for pediatric hematologists; both for a significant relapse rate and for long term therapy-related sequelae. In this context, the use of an innovative technology, such as induced pluripotent stem cells (iPSCs), allows to finely reproduce the primary features of the malignancy and can be exploited as a model to study the onset and development of leukemia in vitro. The aim of this review is to explore the recent literature describing iPSCs as a key tool to study different types of hematological malignancies, comprising acute myeloid leukemia, non-down syndrome acute megakaryoblastic leukemia, B cell acute lymphoblastic leukemia, and juvenile myelomonocytic leukemia. This model demonstrates a positive impact on pediatric hematological diseases, especially in those affecting infants whose onsets is found in fetal hematopoiesis. This evidence highlights the importance of achieving an in vitro representation of the human embryonic hematopoietic development and timing-specific modifications, either genetic or epigenetic. Moreover, further insights into clonal evolution studies shed light in the way of a new precision medicine era, where patient-oriented decisions and therapies could further improve the outcome of pediatric cases. Nonetheless, we will also discuss here the difficulties and limitations of this model

Propylthiouracil-induced cutaneous vasculitis

The use of propylthiouracil (PTU) is associated with the development of different auto-antibodies, amongst them are antineutrophil cytoplasmic antibodies (ANCA) that are involved in the pathogenesis of ANCA associated systemic vasculitis. The case of a 46-years old woman who presented cutaneous vasculitis when taking PTU for Graves' disease is reported. Perinuclear ANCA (p-ANCA) was positive with titer > 1/320, but anti-myeloperoxidase antibodies were not detected. Skin biopsy showed leucocytoclastic vasculitis. The patient improved within ten days after withdrawing PTU and the resolution of hyperthyroidism was achieved with radioiodine (131I). The p-ANCA test remained positive > 1/320 eight months and four years after PTU withdrawal.O uso do propiltiouracil (PTU) está associado ao desenvolvimento de diferentes auto-anticorpos, entre eles anticorpos anticitoplasma de neutrófilos (ANCA), que estão envolvidos na patogênese das vasculites sistêmicas ANCA-associadas (VSAA). Será relatado o caso de um paciente do sexo feminino, de 46 anos, que apresentou vasculite cutânea durante o uso de PTU como terapêutica para doença de Graves. O ANCA com padrão perinuclear (p-ANCA) foi positivo em títulos > 1/320, porém anticorpos antimielo-peroxidase (MPO) não foram detectados. A biópsia de pele revelou uma vasculite leucocitoclástica. Houve melhora clínica em dez dias após a retirada do PTU e optou-se pelo iodo radioativo (I131) para o tratamento do hipertireoidismo. O p-ANCA manteve-se positivo em títulos > 1/320 em duas medidas, realizadas oito meses e quatro anos após a suspensão do PTU.Hospital do Servidor Público Estadual Francisco Morato de OliveiraUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

A possible transport mechanism for aluminum in biological membranes

The transport mechanism of aluminum in lysosomes extracted from rat liver has been investigated in this paper. The experi- mental evidence supports the hypothesis that aluminum is transported inside lysosomes in the form of an Al(OH)3 electroneutral compound, the driving force being the internal acidic pH. This mechanism could help to explain the presence of aluminum in cells in many illnesses

Evidence of a hormetic effect in growth inhibition algal test.

Elutriation process was applied on sediments of Guanabara Bay (Rio de Janeiro, Brazil), a very polluted coastal ecosystem, in order to determine their potential toxicity. Elutriates were tested using Skeletonema costatum, an eurialin Diatom. Several ratios of elutriate/growth medium (v/v) were assayed (1:10, 1:4, and undiluted) as cultural medium for exponentially growing algae, carrying out a blank control for each replicate. Tests were performed for five days, controlling algal growth by manual cell counting by microscope, in order to verify the status of the organisms every assay’s day. This experimental design was proved able to highlight a particular phenomenon, i.e. hormesis. Regarding some sites in the southern part of the Guanabara Bay growth curves, relative to lower sediment elutriate dilutions, showed, in fact, a so called toxic stimulation typical of hormetic event. On the contrary undiluted elutriates never permitted algal growth. Obtained results could help furthermore to explain the particular eutrophic situation of the water body, in which there is a high superficial eutrophization and absolute life deficiency in the deeper water column