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2.
Mater Sci Eng C Mater Biol Appl ; 75: 554-564, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28415499

RESUMO

In this work, plasma electrolytic oxidation (PEO) coatings were produced on AA7075 using alkaline solution containing silicates compounds and silver micrometric particles in order to give to the coating an antimicrobial effect. In the optic of circular economy, silver chloride derived from the acid pre-treatment of electronic scraps was used as raw material and successively silver powders were synthesized from silver chloride solution using glucose syrup as reducing agent. The coatings were characterized by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and antimicrobial tests. The results evidenced that the obtained coatings were homogenous and give to the samples higher corrosion resistance than untreated alloy. The silver particles, found both inside and outside of the pores that characterize the PEO layer, produced an efficacious antimicrobial effect both against E. coli and S. aureus.


Assuntos
Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Escherichia coli/crescimento & desenvolvimento , Gases em Plasma/química , Prata/química , Staphylococcus aureus/crescimento & desenvolvimento , Oxirredução , Compostos de Prata/química
3.
J Hazard Mater ; 305: 105-114, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26651067

RESUMO

Similarly to many powders of solids, dried sludge originated from tannery wastewater may result in a self-heating process, under given circumstances. In most cases, it causes a moderate heating (reaching 70-90°C), but larger, off-design residence times in the drier, in a suboxic atmosphere, extremely reactive solids can be produced. Tannery waste contains several chemicals that mostly end up in the wastewater treatment sludge. Unexpected and uncontrolled self heating could lead to a combustion and even to environmental problems. Elaborating on previous studies, with the addition of several analytical determinations, before and after the self-heating, we attempted to formulate a mechanism for the onset of heating. We demonstrated that the system Fe/S/O has been involved in the process. We proved that the formation of small quantities of pyrophoric iron sulfides is the key. They are converted to sulfated by reaction with water and oxygen with exothermic processes. The pyrite/pyrrhotite production depends on the sludge drying process. The oxidation of sulfides to oxides and sulfates through exothermic steps, reasonably catalyzed by metals in the sludge, occurs preferentially in a moist environment. The mechanism has been proved by reproducing in the laboratory prolonged heating under anoxic/suboxic atmosphere.

4.
Waste Manag ; 34(4): 817-24, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24484766

RESUMO

We studied the spontaneous heating of dried sludge produced by treating wastewater mainly originating from tanneries. Heating up to burning has been observed in the presence of air and moisture, starting at ambient temperature. To understand and prevent the process we combined chemical and morphological analyses (ESEM) with thermal activity monitoring in insulated vessels. Selective additions of chemicals, either to amplify or depress the reactivity, have been used to investigate and identify both the chemical mechanism causing the sludge self-heating, and a prevention or a mitigation strategy. FeS additions accelerate the onset of reactivity, while S sustains it over time. On the contrary, Ca(OH)2, Na2CO3, NaHCO3, FeCl2, EDTA, NaClO can limit, up to completely preventing, the exothermic activity. All the experimental evidences show that the reactions supporting the dried sludge self-heating involve the Fe/S/O system. The total suppression of the reactivity requires amounts of additives that are industrially incompatible with waste reduction and economics. The best prevention requires reduction or removal of S and Fe from the dried solid matrix.


Assuntos
Temperatura Alta , Resíduos Industriais , Curtume , Águas Residuárias/química , Hidróxido de Cálcio/química , Carbonatos/química , Ácido Edético/química , Compostos Ferrosos/química , Resíduos Industriais/análise , Hipoclorito de Sódio/química , Enxofre/análise , Enxofre/química , Gerenciamento de Resíduos
5.
Plant Dis ; 98(8): 1036-1042, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30708784

RESUMO

Yellow leaf disease, caused by Sugarcane yellow leaf virus (SCYLV), is widespread around the world but very little information is available on this viral disease in Argentina. Therefore, the aims of the study were to assess the presence of SCYLV, analyze its distribution in the main sugarcane production areas of Argentina, characterize the virus, and determine histological alterations caused by its presence. For this purpose, 148 sugarcane samples with and without symptoms were collected in 2011 and 2012 from the province of Tucumán. One additional sample was collected in Salta, a different geographical, agroecological, and producing region. Results showed that SCYLV is widely distributed in commercial varieties of sugarcane throughout Tucumán in both symptomatic and asymptomatic leaves. A low but statistically significant positive correlation with virus detection and disease symptoms was found. BRA-PER was the only genotype detected by reverse-transcription polymerase chain reaction and sequence analysis of the SCYLV capsid protein gene. SCYLV-positive samples showed high starch levels in bundle sheath cells, whereas the asymptomatic ones, probably in an early stage of infection, were found to contain more chloroplasts. Symptomatic noninfected samples presented crystal formation probably associated with phytoplasma infection.

6.
Arq. Inst. Biol. (Online) ; 78(1): 137-139, jan-mar, 2011. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1396455

RESUMO

Neste trabalho estudou-se a reação de maracujazeiro amarelo 'Maguari' e 'Afruvec' ao fitonematoide Meloidogyne incognita raça 3, em casa-de-vegetação. Adotou-se o delineamento inteiramente casualizado, com três tratamentos (Maguari, Afruvec e Tomateiro cv. Rutgers) e quatro repetições, sendo a parcela constituída por um vaso contendo uma planta. Após seis meses, avaliou-se o índice de galhas e de massa de ovos nas cultivares de maracujazeiro amarelo e no tomateiro cv. Rutgers. A classificação da resistência ao fitonematoide foi feita utilizando o critério do fator de reprodução (FR). A 'Maguari' apresentou zero de índice de galhas e de massa de ovos, enquanto que 'Afruvec' mostrou baixo índice de galhas e massa de ovos comparativamente com o tomateiro cv. Rutgers. De acordo com o FR, a 'Maguari' enquadrou-se como imune ao nematoide, sendo a 'Afruvec' resistente e o tomateiro cv. Rutgers como suscetível.


This study concerned the reaction of yellow passion fruit 'Maguary' and 'Afruvec' to the phytonematode Meloidogyne incognita race 3 in greenhouse conditions. An entirely randomized experimental design with 3 treatments ('Maguary', 'Afruvec', and tomato cv. 'Rutgers') and 4 repetitions was used, each plot consisting of 1 vase containing 1 plant. After 6 months, an evaluation was made of the index of galls and egg mass in the yellow passion fruit varieties and in the tomato cv. 'Rutgers'. The classification of resistance to the phytonematode was made by criterion of the reproduction factor (RF). 'Maguary' presented a zero index of galls and egg mass, while 'Afruvec' showed a low index of galls and egg mass in relation to the tomato cv. Rutgers. According to the RF, 'Maguary' was characterized as immune to the phytonematode, while 'Afruvec' was resistant, and the tomato cv. 'Rutgers' was susceptible.


Assuntos
Tumores de Planta , Tylenchoidea , Passiflora/fisiologia , Nematoides
7.
J Biol Inorg Chem ; 12(4): 477-93, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17211629

RESUMO

A series of platinum(II) amidine complexes were previously prepared with the aim of obtaining a new class of platinum-based antitumour drugs. This series includes compounds of the type cis--[PtCl2{Z-HN=C(NHMe)Me}2] and trans-[PtCl2{Z-HN=C(NHMe)Me}2] (1, 2), cis-[PtCl2{E-HN=C(NMe2)Me}2] and trans-[PtCl2{E-HN=C(NMe2)Me}2] (3, 4), cis-[PtCl2{Z-HN=C(NHMe)Ph}2] and trans-[PtCl2{Z-HN=C(NHMe)Ph}2] (5, 6), and cis-[PtCl2{HN=C(NMe2)Ph}2] and trans-[PtCl2{HN=C(NMe2)Ph}2] (7, 8). The reactions with dimethyl sulfoxide were studied for complexes 5-8; the formation of cationic species containing coordinated dimethyl sulfoxide was demonstrated by NMR experiments and electrospray ionization mass spectrometry. In this work, the amidine platinum(II) complexes were tested for their in vitro cytotoxicity on a panel of various human cancer cell lines. The results indicate that the benzamidine complex 8 was the most effective derivative also circumventing acquired cisplatin resistance as demonstrated by chemosensitivity tests performed on cisplatin-sensitive and cisplatin-resistant cell lines. The studies concerning the cellular DNA damage on both parental chemosensitive and resistant sublines suggest for the new trans-amidine complex a different mechanism of action compared with that exhibited by cisplatin.


Assuntos
Furanos/química , Furanos/toxicidade , Compostos de Platina/química , Compostos de Platina/toxicidade , Amidinas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/farmacologia , DNA/química , DNA/metabolismo , Humanos , Isomerismo , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Compostos de Platina/isolamento & purificação , Soluções , Espectrometria de Massas por Ionização por Electrospray
8.
Scand J Clin Lab Invest ; 66(1): 19-30, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16464784

RESUMO

OBJECTIVE: To investigate the reliability of bioelectrical impedance analysis (BIA) in estimating total body water (TBW) and extracellular water (ECW) in elderly patients suffering from congestive heart failure (CHF). MATERIAL AND METHODS: In 72 elderly subjects, 34 with CHF (aged 83.9+/-6.9 years) and 38 healthy controls (78.7+/-7.5 years), TBW and ECW values were assessed using dilution methods, and bioelectrical variables were measured using single frequency BIA (SF-BIA) at 1 and 50 kHz, and bioelectrical spectroscopy (BIS). RESULTS: In CHF patients, Ht(2)/R(1) correlated weakly with TBW (r = 0.56) and ECW (0.47). In both healthy controls and CHF patients, TBW correlated strongly with Ht(2)/R(50), Ht(2)/R(0), Ht(2)/R(8) and Ht(2)/Zc. Using multiple regression analysis and the Bland-Altmann approach, SF-BIA at 50 kHz and BIS proved similar in predicting TBW for both the explained variance (R(2)~0.89) and the limits of agreement. In all subjects, ECW was estimated best by including height, weight and Ht(2)/R(0 )(R(2) 0.75) or Ht(2)/Zc (R(2) 0.77) in multivariate models, while SF-BIA at 50 kHz did not explain more than 71 % of ECW variability. The SEE % was nonetheless about twice the SEE % for estimating TBW. CONCLUSIONS: SF-BIA at 1 kHz is unreliable in predicting body fluids in elderly people with CHF. SF-BIA at 50 kHz and BIS are useful for estimating TBW in healthy elderly people and in cases of water imbalance, but both methods are less reliable in estimating ECW, particularly in conditions of fluid overload.


Assuntos
Compartimentos de Líquidos Corporais , Impedância Elétrica , Insuficiência Cardíaca/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Água Corporal , Espaço Extracelular , Feminino , Humanos , Masculino , Análise de Regressão
11.
Toxicon ; 32(10): 1211-5, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7846691

RESUMO

From 1966 to 1991 91 cases of bites due to mygalomorph spiders were recorded at the Hospital Vital Brazil, Instituto Butantan, São Paulo, Brazil, representing less than 1% of all spider bites. The diagnosis was confirmed by positive identification of the spider involved. Envenoming is generally mild, the main symptom is local pain, and there is minor oedema and erythema. The data confirm the assumption that these nonaggressive spiders pose no health problem.


Assuntos
Picada de Aranha/epidemiologia , Venenos de Aranha/intoxicação , Adulto , Analgésicos/administração & dosagem , Analgésicos/uso terapêutico , Brasil/epidemiologia , Criança , Pré-Escolar , Edema/induzido quimicamente , Feminino , Antagonistas dos Receptores Histamínicos H1/administração & dosagem , Antagonistas dos Receptores Histamínicos H1/uso terapêutico , Humanos , Lactente , Masculino , Dor/induzido quimicamente , Picada de Aranha/tratamento farmacológico
12.
Amino Acids ; 5(3): 389-401, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24190710

RESUMO

The nature of the products arising from a 10 days, sterile incubation at 37°C and pH 7.2 of a 1:1 mixture of N-α-(p-tosyl)-lysine-methylesterhydrochloride and anhydrous D-glucose was investigated by fast atom bombardment mass spectrometry and(1)H and(13)C nuclear magnetic resonance spectroscopies. Differently to the reactivity usually described on the basis of other analytical techniques, FAB mass spectrometric measurements indicate the occurrence of the reaction of protected lysine with more than one D-glucose molecule.

13.
Minerva Pediatr ; 43(1-2): 45-7, 1991.
Artigo em Italiano | MEDLINE | ID: mdl-1903499

RESUMO

The case of a girl with Seckel syndrome, born of an epileptic mother who was taking anticonvulsant drugs, is reported. The patient, admitted to our clinic for short stature, presented some signs of Seckel syndrome: microcephaly, a "bird headed" profile with receding chin and forehead and large beaked nose. Microcephaly and a low birth weight are present in Seckel syndrome, but also in the newborn of epileptic mothers who received anticonvulsive drugs. In the present paper the Authors questioned if the described syndrome was caused by the use of antiepileptic drugs during pregnancy, or epilepsy of the mother, or if it was casual.


Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Anticonvulsivantes/efeitos adversos , Peso ao Nascer , Criança , Epilepsia Tônico-Clônica/tratamento farmacológico , Expressão Facial , Feminino , Humanos , Deficiência Intelectual/etiologia , Microcefalia/induzido quimicamente , Microcefalia/etiologia , Gravidez , Complicações na Gravidez/tratamento farmacológico , Síndrome
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