Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21.165
Filtrar
1.
Ann Clin Biochem ; 57(3): 262-265, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32266828

RESUMO

BACKGROUND: Early studies have reported various electrolyte abnormalities at admission in patients who progress to the severe form of coronavirus disease 2019 (COVID-19). As electrolyte imbalance may not only impact patient care, but provide insight into the pathophysiology of COVID-19, we aimed to analyse all early data reported on electrolytes in COVID-19 patients with and without severe form. METHODS: An electronic search of Medline (PubMed interface), Scopus and Web of Science was performed for articles comparing electrolytes (sodium, potassium, chloride and calcium) between COVID-19 patients with and without severe disease. A pooled analysis was performed to estimate the weighted mean difference (WMD) with 95% confidence interval. RESULTS: Five studies with a total sample size of 1415 COVID-19 patients. Sodium was significantly lower in patients with severe COVID-19 (WMD: -0.91 mmol/L [95% CI: -1.33 to -0.50 mmol/L]). Similarly, potassium was also significantly lower in COVID-19 patients with severe disease (WMD: -0.12 mmol/L [95% CI: -0.18 to -0.07 mmol/L], I2=33%). For chloride, no statistical differences were observed between patients with severe and non-severe COVID-19 (WMD: 0.30 mmol/L [95% CI: -0.41 to 1.01 mmol/L]). For calcium, a statistically significant lower concentration was noted in patients with severe COVID-19 (WMD: -0.20 mmol/L [95% CI: -0.25 to -0.20 mmol/L]). CONCLUSIONS: This pooled analysis confirms that COVID-19 severity is associated with lower serum concentrations of sodium, potassium and calcium. We recommend electrolytes be measured at initial presentation and serially monitored during hospitalization in order to establish timely and appropriate corrective actions.


Assuntos
Infecções por Coronavirus/sangue , Eletrólitos/sangue , Pneumonia Viral/sangue , Betacoronavirus , Cálcio/sangue , Cloretos/sangue , Infecções por Coronavirus/fisiopatologia , Humanos , Pandemias , Pneumonia Viral/fisiopatologia , Potássio/sangue , Sódio/sangue , Equilíbrio Hidroeletrolítico
2.
Waste Manag ; 106: 250-260, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32240941

RESUMO

Here in this work, porous carbon is prepared from waste of a traditional Chinese medicine Salvia miltiorrhiza flowers. Structures of the porous carbons are regulated by simply regulating of activation temperatures and dosages of activator. The optimized porous carbon owns a high specific surface area of 1715.3 m2 g-1 and total pore volume of 0.6392 cm3 g-1, together with a unique hierarchical architecture and ultrahigh content of 45.97 at% self-doped O and 0.49 at% of N. When used as electrode materials for supercapacitors, the prepared porous carbon exhibited excellent specific capacitance and energy density as well as fantastic cycle stability. Under a current density of 0.5 A/g, the electrode based on this material showed high specific capacitance of 530 F/g, with fantastic rate performance of 258 F/g at 20 A/g and excellent cycle stability of 91% capacitance retention for 10,000 cycles at 10 A/g in a three-electrode system in 6 M KOH. In assembled supercapacitors, the SF-PC700-3 based electrode worked under potential of 1 V and exhibited 222 F/g of specific capacitance at a current density of 0.5 A/g, and even when the current density was increased up to 30 A/g, the specific capacitance can still as high as 168 F/g, verified the excellent performance of SF-PC700-3. Symmetric supercapacitors in Na2SO4 and TEABF4/AN electrolyte showed voltage ranges of 1.8 V and 3 V respectively, and high energy density of 22.2 Wh Kg-1 at 448. W Kg-1 and 40.6 Wh Kg-1 at 755.8 W Kg-1 are obtained.


Assuntos
Carbono , Eletrólitos , Capacitância Elétrica , Eletrodos , Porosidade
3.
Phys Chem Chem Phys ; 22(12): 6749-6754, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32167106

RESUMO

The enzymatic activity of alcohol dehydrogenase (ADH) in the presence of a range of electrolytes is investigated. In the presence of 150 and 200 mM cations a substantial increase in activity following the series GnCl < CsCl < KCl ∼ NaCl < LiCl was observed with a 69% increase in the presence of KCl 200 mM with respect to the salt-free solution. In the presence of 150 and 200 mM anions the increase in activity followed an ion specific trend NaF ∼ NaCl ∼ NaBr > no salt > NaClO4 > NaSCN with a peak in activity increase of 75% in the presence of NaBr. The values of the Michaelis-Menten constant (Km) did not show any significant ion specific effect, while the maximum rate (Vmax) of ethanol oxidation to acetaldehyde was strongly ion specific. The changes in specific activity and Vmax in the presence of anions likely arises from ion specific interactions with charged residues in the active site of ADH. The data indicate that the enzymatic activity of alcohol dehydrogenase can be modulated by the nature of electrolytes at physiological concentration.


Assuntos
Álcool Desidrogenase/metabolismo , Eletrólitos/química , Saccharomyces cerevisiae/enzimologia , Álcool Desidrogenase/química , Eletrólitos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Etanol/metabolismo , Oxirredução
4.
J Assoc Physicians India ; 68(3): 80-82, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32138493

RESUMO

Cases have been reported about refeeding syndrome after bariatric surgery for obesity, in head and neck cancer patients, in patients with anorexia nervosa, hyperemesis gravidarum, in persons on hunger strike, malnourished alcoholic persons and persons doing religious fasting. Refeeding after prolonged fasting can cause severe morbidity and even mortality, if not done properly. Depletion of intracellular electrolytes, depletion of nutrients and vitamins, decreased BMR, decreased renal functions, decreased insulin, decreased GI functions all contribute to it, once you start refeeding. It takes sometime to regain the original functions by the organs and mismatch between supply and increased demand after refeeding can cause havoc. Here we report the case of a person, who did water only fasting for 51 days and developed refeeding syndrome and Wernike's encephalopathy four days after starting liquid diet.


Assuntos
Encefalopatias , Síndrome da Realimentação , Anorexia Nervosa , Eletrólitos , Jejum , Feminino , Humanos , Gravidez
5.
Nature ; 579(7798): 224-228, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32123353

RESUMO

Large-scale energy storage is becoming increasingly critical to balancing renewable energy production and consumption1. Organic redox flow batteries, made from inexpensive and sustainable redox-active materials, are promising storage technologies that are cheaper and less environmentally hazardous than vanadium-based batteries, but they have shorter lifetimes and lower energy density2,3. Thus, fundamental insight at the molecular level is required to improve performance4,5. Here we report two in situ nuclear magnetic resonance (NMR) methods of studying redox flow batteries, which are applied to two redox-active electrolytes: 2,6-dihydroxyanthraquinone (DHAQ) and 4,4'-((9,10-anthraquinone-2,6-diyl)dioxy) dibutyrate (DBEAQ). In the first method, we monitor the changes in the 1H NMR shift of the liquid electrolyte as it flows out of the electrochemical cell. In the second method, we observe the changes that occur simultaneously in the positive and negative electrodes in the full electrochemical cell. Using the bulk magnetization changes (observed via the 1H NMR shift of the water resonance) and the line broadening of the 1H shifts of the quinone resonances as a function of the state of charge, we measure the potential differences of the two single-electron couples, identify and quantify the rate of electron transfer between the reduced and oxidized species, and determine the extent of electron delocalization of the unpaired spins over the radical anions. These NMR techniques enable electrolyte decomposition and battery self-discharge to be explored in real time, and show that DHAQ is decomposed electrochemically via a reaction that can be minimized by limiting the voltage used on charging. We foresee applications of these NMR methods in understanding a wide range of redox processes in flow and other electrochemical systems.


Assuntos
Fontes de Energia Elétrica , Espectroscopia de Ressonância Magnética , Eletrólitos/química , Elétrons , Oxirredução
6.
Chemosphere ; 249: 126129, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062210

RESUMO

A novel coagulant poly-ferric-titanium-silicate-sulfate (PFTS) was synthesized and employed to treat two typical kinds of dye wastewaters-disperse blue and reactive yellow. The results indicated that PFTS with a Si/Fe molar ratio of 0.02 exhibited superior coagulation performance, especially under alkaline condition. The residual turbidity after coagulation by PFTS was only half of that after coagulation by poly-ferric-titanium sulfate (T-PSF). The sludge volume index was also reduced by PFTS compared to T-PSF in reactive dye treatment. Through the structure and morphology investigation of PFTS, it was found that new bonds of Si-O-Fe, Si-O-Ti and Fe-OH (Si-OH) were formed, and multi-branched structures and expanded surface area were generated. Additionally, compared with T-PSF, the floc strength and the floc size were also enhanced by PFTS, which was attributed to the polymerization between polysilicic acid and Fe/Ti which formed multi-branched structures, and finally adsorption and bridging ability of the coagulant was improved. Furthermore, the floc formed in reactive yellow wastewater treatment was larger and looser than that formed in disperse blue wastewater, with poorer strength and recovery ability, which can also interpret the better coagulation efficiency in disperse dye water treatment. From the results of coagulant characterization, zeta potential and flocs properties, it can be inferred that charge neutralization by the positive charged hydrolysate of coagulant was identified as the critical effect in disperse dyes removal, while the sweep and adsorption of metal hydroxyl compound formed during the hydrolysis of coagulants were considered to play a key role in reactive dye removal.


Assuntos
Corantes/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Adsorção , Cloretos/química , Eletrólitos , Compostos Férricos , Floculação , Hidrólise , Ferro , Esgotos , Silicatos , Sulfatos , Titânio/química , Águas Residuárias/química , Purificação da Água/métodos
7.
Crit Care Resusc ; 22(1): 80-82, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32102646

RESUMO

BACKGROUND: Due to the lack of double-blind randomised controlled trials, the true effect of intravenous sodium bicarbonate therapy in ICU patients with metabolic acidosis remains unclear. METHODS: We diluted 100 mL 8.4% sodium bicarbonate in 150 mL 5% dextrose (D5W) within a 250 mL polyolefin bag after removing 100 mL. We asked ICU clinicians to inspect a 250 mL bag containing sodium bicarbonate or a 250 mL bag where 100 mL of D5W had been removed and then returned. The bags were attached to intravenous giving sets. We asked participants to identify the contents of the bags. RESULTS: Among 60 participants (39 nursing staff [65%], 20 medical staff [33.3%] and one pharmacist), 36 (60%) answered correctly. The Cohen κ for agreement between test bag content and participants' answers was 0.20 (95% CI, -0.05 to 0.45; P = 0.12), implying the answers were correct by chance. In the group of 28 participants who indicated they used a clue to help them decide their answer, 15 (53.6%) answered correctly, whereas in the remainder (n = 32), 21 (65.6%) answered correctly (P = 0.49). CONCLUSION: When 100 mL of 8.4% sodium bicarbonate were diluted in 150 mL of D5W within a 250 mL polyolefin bag, clinicians were unable to correctly identify the contents of the bags. Our findings imply that sodium bicarbonate therapy can be successfully blinded.


Assuntos
Acidose/tratamento farmacológico , Glucose/uso terapêutico , Bicarbonato de Sódio/uso terapêutico , Administração Intravenosa , Método Duplo-Cego , Eletrólitos , Glucose/administração & dosagem , Humanos , Injeções Intravenosas , Sódio/sangue , Bicarbonato de Sódio/administração & dosagem , Resultado do Tratamento
9.
Medicine (Baltimore) ; 99(2): e18709, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914079

RESUMO

Kidney handling of electrolytes varies in different stages of chronic kidney disease (CKD). Diabetes mellitus (DM) plays an important role in CKD. Fractional excretion (FE) is an important means in clinical practice. The relationship between FE of electrolytes in patients at different stages of CKD is worth further investigating.We designed a cross-sectional study in 1 teaching hospital, consecutive CKD patients were enrolled between February 2016 and January 2017. Including clinical demographic features, laboratory examination including spot urine electrolytes, blood biochemistries, and relevant medications were determined.A total of 762 CKD patients completed the study. Of these, 218 (28.6%) had DM. Participants were grouped according to estimated glomerular filtration rate into 7 categories: hyperfiltration (HF), CKD1, CKD2, CKD3a, CKD3b, CKD4, and CKD5. Groups HF, CKD1, 2, 3a, 3b, 4 and 5 contained 83, 143, 192, 94, 82, 82, and 86 patients, respectively. FE of electrolytes tended to increase along with the decline of renal function (CKD1-CKD5) (P < .001). The relationship was similar between the DM and non-DM groups. Diabetic patients demonstrated higher FE of magnesium compared with non-DM subjects at CKD2 and CKD5 (P < .05).CKD patients showed a progressive increase in the FE of electrolytes; FE of magnesium seemed to increase more among diabetic patients with CKD, and could be a potential predictor of CKD progression.


Assuntos
Eletrólitos/metabolismo , Taxa de Filtração Glomerular/fisiologia , Insuficiência Renal Crônica/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Eletrólitos/urina , Feminino , Humanos , Magnésio/metabolismo , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
10.
Nat Biotechnol ; 38(2): 189-198, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31932726

RESUMO

The ability to preserve metabolically active livers ex vivo for 1 week or more could allow repair of poor-quality livers that would otherwise be declined for transplantation. Current approaches for normothermic perfusion can preserve human livers for only 24 h. Here we report a liver perfusion machine that integrates multiple core physiological functions, including automated management of glucose levels and oxygenation, waste-product removal and hematocrit control. We developed the machine in a stepwise fashion using pig livers. Study of multiple ex vivo parameters and early phase reperfusion in vivo demonstrated the viability of pig livers perfused for 1 week without the need for additional blood products or perfusate exchange. We tested the approach on ten injured human livers that had been declined for transplantation by all European centers. After a 7-d perfusion, six of the human livers showed preserved function as indicated by bile production, synthesis of coagulation factors, maintained cellular energy (ATP) and intact liver structure.


Assuntos
Fígado/lesões , Perfusão/instrumentação , Preservação Biológica , Trifosfato de Adenosina/metabolismo , Alarminas/metabolismo , Animais , Biomarcadores/metabolismo , Eletrólitos/metabolismo , Glucose/metabolismo , Hemodinâmica , Hemólise , Humanos , Fígado/fisiopatologia , Oxigênio/metabolismo , Consumo de Oxigênio , Veia Porta/metabolismo , Reperfusão , Suínos
11.
Clin Biochem ; 77: 32-35, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31891680

RESUMO

INTRODUCTION: The avoidance of repeat chemistry testing such as Complete Blood Count (CBC) and Electrolyte Panel (EP) on clinically stable patients was identified as important utilization goals by Choosing Wisely Canada. The purpose of this study was to assess the volume of overutilization of CBC and EP in an inpatient setting in Alberta, Canada, and provide an estimated cost assessment of unnecessary testing. METHODS: The total laboratory testing volumes of two common test panels were collected retrospectively for one-year from January to December 2018. Data was collected on test panels performed in an emergency room (ER) and inpatient setting from three separate Laboratory Information Systems covering the provincial population in Alberta, Canada. Total initial test panel instances, total repeated panels, repeated panels that were previously normal or abnormal, and estimated costs were examined. Cost assessment was completed based on Reference Median Cost (RMC) analysis for each of these two common test panels. RESULTS: During the study period, 2,020,467 (CBC) and 1,455,983 (EP) initial test panel instances were recorded, of which 67.7% and 73.5% were repeated for the CBC and EP, respectively. There was a higher proportion of EP repeated inappropriately (previously normal; 35.6%) compared to CBCs (5.4%). The cost to the province for inappropriately repeating CBC and EP were estimated to be RMC $0.52 million and RMC $1.90 million CAD, respectively. CONCLUSION: Results from this study can assist policy makers in implementing utilization management initiatives and update clinical practice guidelines to reduce costs to healthcare without compromising patient care.


Assuntos
Contagem de Células Sanguíneas/normas , Testes Diagnósticos de Rotina/estatística & dados numéricos , Eletrólitos/normas , Alberta , Humanos
12.
J Chromatogr A ; 1609: 460519, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31521379

RESUMO

In this work, tetraalkylammonium amino acid ionic liquids (TAA-AAILs) were first applied to non-aqueous capillary electrophoresis (NACE) to establish synergistic systems with a conventional chiral selector, native ß-cyclodextrin (ß-CD). Excellent enantioseparations of some dansyl-amino acid (Dns-AA) samples were achieved. A series of comparison experiments and a molecular docking study were performed to validate the synergistic effect of TAA-AAILs and ß-CD in NACE. Several interesting results were observed compared with previously reported chiral ILs-related aqueous CE studies. In particular, the direct enantioselectivity of TAA-AAILs was observed for the first time by using it as sole chiral selector in NACE. This was an encouraging finding because it was the first direct and convincing evidence that AAILs were able to participate in the enantiorecognition process in the conventional chiral selectors-based synergistic systems. The new TAA-AAILs synergistic NACE system was further optimized in terms of alkyl chain length, TAA-AAILs concentration, ß-CD concentration, electrolyte composition and applied voltage, etc. Best enantioseparations of Dns-AAs were obtained when 100 mM ß-CD and 10 mM tetramethylammonium-l-arginine (TMA-l-Arg) were added in an NMF buffer containing 50 mM Tris and 35 mM CA (apparent pH 7.85) under UV detection. The applied voltage was set at 30 kV. The method was then successfully employed for the determination of enantiomeric impurities of a real AA sample. This work proved that the use of chiral ILs as additives in NACE is a promising approach for enantioseparation.


Assuntos
Eletroforese Capilar/métodos , Líquidos Iônicos/química , Arginina/análogos & derivados , Arginina/química , Tampões (Química) , Eletrólitos/química , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Compostos de Amônio Quaternário/química , Estereoisomerismo , beta-Ciclodextrinas/química
13.
Waste Manag ; 102: 330-339, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31711027

RESUMO

Single-step synthesis of porous carbon (PC) from biomass is a challenge via microwave heating, because biomass rarely absorbs the microwave energy. Herein, wheat-straw-derived char, as a good microwave absorber, was used to achieve rapidly single-step synthesis of PC from an agricultural waste (wheat straw). KOH was used to generate abundant micropores in the PCs. High heating rate caused by microwave heating combined with the pyrolysis gases resulted in the formation of meso-/macropores. A series of post-oxidation reactions between active sites in the PCs and oxygen in the air led to the doping of oxygen-containing chemical groups. Consequently, the obtained PC possessed a high specific surface area of 1905 m2 g-1, a balanced pore distribution with abundant micropores (0.62 cm3 g-1), considerable content of meso-/macropores (0.53 cm3 g-1), and an oxygen-enriched structure (oxygen content up to 21.6%). These characteristics not only contributed to the achievement of a high specific capacitance of 268.5 F g-1 at 0.5 A g-1 for the resultant supercapacitor, but also resulted in an excellent rate capability with a high capacitance retention of 81.2% at 10 A g-1 in a gel electrolyte (polyvinyl alcohol/LiCl). This supercapacitor can extract a high energy density of 21.5 W h kg-1 at 0.5 A g-1 and a high power density of 7.2 kW kg-1 at 10 A g-1.


Assuntos
Carbono , Eletrólitos , Biomassa , Capacitância Elétrica , Porosidade
14.
Aquat Toxicol ; 218: 105363, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31783302

RESUMO

The aquatic environment is continuously under threat because it is the final receptor and sink of waste streams. The development of industry, mining activities and agriculture gave rise to an increase in metal pollution in the aquatic system. Thus a wide occurrence of metal mixtures exists in the aquatic environment. The assessment of mixture stress remains a challenge considering that we can not predict the toxicity of a mixture on the basis of single compounds. Therefore the analysis of the effects of environmentally relevant waterborne mixtures is needed to improve our understanding of the impact of metal pollution in aquatic ecosystems. Our aim was to assess whether 10 % of the concentration of the 96 h LC50 (the concentration that is lethal to 50 % of the population in 96 h) of individual metal exposures can be considered as a "safe" concentration when applied in a trinomial mixture. Therefore, common carp were exposed to a sublethal mixture of Cu 0.07 ±â€¯0.001 µM (4.3 ±â€¯0.6 µg/L), Zn 2.71 ±â€¯0.81 µM (176.9 ±â€¯52.8 µg/L) and Cd 0.03 ±â€¯0.0004 µM (3.0 ±â€¯0.4 µg/L) at 20 °C for a period of one week. Parameters assessed included survival rate, bioaccumulation and physiological biomarkers related to ionoregulation and defensive mechanisms such as MT induction. Our results showed a sharp increase in Cu and Cd concentration in gills within the first day of exposure while Zn levels remained stable. The accumulation of these metals led to a Na drop in gills, liver and muscle as well as a decreased K content in the liver. Biomarkers related to Na uptake were also affected: on the first day gene expression for H+-ATPase was transiently increased while a concomitant decreased gene expression of the Na+/H+ exchanger occurred. A fivefold induction of metallothionein gene expression was reported during the entire duration of the experiment. Despite the adverse effects on ionoregulation all fish survived, indicating that common carp are able to cope with these low metal concentrations, at least during a one week exposure.


Assuntos
32418 , Cádmio/toxicidade , Carpas/metabolismo , Cobre/toxicidade , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , 32418/genética , Biomarcadores/metabolismo , Cádmio/metabolismo , Carpas/genética , Cobre/metabolismo , Ecossistema , Eletrólitos/metabolismo , Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Dose Letal Mediana , Metalotioneína/genética , ATPases Translocadoras de Prótons/genética , Poluentes Químicos da Água/metabolismo , Zinco/metabolismo
15.
Chemosphere ; 239: 124730, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726518

RESUMO

The impact of electrolytes on the adsorption of emerging pollutants: pharmaceuticals onto layered materials: a raw clay mineral and its nonionic and cationic organoclay derivatives was studied. The selected pharmaceuticals: amoxicillin, norfloxacin, sulfamethoxazole, metoprolol, carbamazepine, and trimethoprim show different electric charges: zwitterionic, anionic, cationic and neutral and hydrophobic character (different LogP). Without any salts, the set of complementary data obtained by UV and infrared spectroscopies, X-ray diffraction points out the importance of the electric charge which represents a key parameter in both the spontaneity and feasibility of the adsorption. In contrast, the hydrophobicity of the analytes plays a minor role but determines the magnitude of the adsorbed amount of pharmaceuticals onto organoclays. With a dual hydrophilic and hydrophobic behavior, nonionic organoclay appears to be the most polyvalent material for the removal of the pharmaceuticals. In the presence of electrolytes (NaCl at a concentration of 1 × 10-2 mol L-1), both nonionic and cationic organoclays show a decrease of their efficiencies, whereas the adsorption is particularly enhanced for Na-Mt except for the cationic species (trimethoprim and metoprolol). Thus, in realistic experimental conditions close to those of natural effluents, raw clay mineral appears as the most appropriate sorbent for the studied pharmaceuticals while it raises the question of the usefulness of organoclays in water remediation strategy.


Assuntos
Eletrólitos/química , Recuperação e Remediação Ambiental/métodos , Preparações Farmacêuticas/análise , Poluentes do Solo/análise , Solo/química , Poluentes Químicos da Água/análise , Adsorção , Amoxicilina/análise , Amoxicilina/química , Carbamazepina/análise , Carbamazepina/química , Cátions/análise , Interações Hidrofóbicas e Hidrofílicas , Metoprolol/análise , Metoprolol/química , Norfloxacino/análise , Norfloxacino/química , Preparações Farmacêuticas/química , Poluentes do Solo/química , Sulfametoxazol/análise , Sulfametoxazol/química , Trimetoprima/análise , Trimetoprima/química , Água/química , Poluentes Químicos da Água/química , Difração de Raios X
16.
N Z Vet J ; 68(1): 60-64, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31433953

RESUMO

Aims: To compare urine urinary pH, blood pH and concentration of electrolytes in blood of healthy horses fed an anionic salt supplement to achieve diets with a dietary cation-anion difference (DCAD) of -40 or 0 mEq/kg DM, with horses a fed a diet with a DCAD of 85 mEq/kg DM.Methods: Eight healthy horses received each of three diets in a randomised crossover design. Diets consisted of grass hay and concentrate feed, with a varying amount of an anionic supplement to achieve a DCAD of 85 (control), 0 or -40 mEq/kg DM. They were fed for 14 days each with a washout period of 7 days between. Urine pH was measured daily and blood samples were collected on Days 0, 7 and 14 of each study period for the measurement of pH and concentration of electrolytes.Results: Four horses voluntarily consumed the anionic supplement with their feed, but four horses required oral supplement administration via dose syringe. During the study period mean urine pH was lower in horses fed diets with a DCAD of 0 (6.91; SD 0.04) and -40 (6.83; SD 0.04) mEq/kg DM compared to the control diet (7.30; SD 0.04). Compared with horses fed the control diet, mean urine pH was lower in horses fed the 0 and -40 mEq/kg DM diets on Days 1-12 and 14 (p < 0.05) of the study period. On Day 13 it was only lower in horses fed the -40 mEq/kg DM diet (p < 0.01). Urine pH was similar for horses fed the 0 and -40 mEq/kg DM diets (p = 0.151). The DCAD of the diet had no effect on blood pH, ionised Ca or anion gap. Mean concentrations of bicarbonate in blood were affected by diet (p = 0.049); they were lower when horses were fed the 0 mEq/kg diet relative to the control diet on Day 14.Conclusions and clinical relevance: The anionic supplement reduced urine pH in horses fed diets with a DCAD of 0 or -40 mEq/kg DM compared with 85 mEq/kg DM. However as urinary pH did not fall below pH 6.5, the pH below which calcium carbonate uroliths do not form, this reduction in urine pH is unlikely to be clinically significant. The supplement was variably palatable and showed minimal promise as an effective urinary acidifier at the doses administered in this study.


Assuntos
Ração Animal/análise , Ânions/sangue , Suplementos Nutricionais , Eletrólitos/sangue , Cavalos/sangue , Urinálise/veterinária , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ânions/administração & dosagem , Estudos Cross-Over , Dieta/veterinária , Eletrólitos/administração & dosagem , Feminino , Cavalos/urina , Concentração de Íons de Hidrogênio , Masculino , Urina/química
17.
Water Res ; 171: 115401, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31884379

RESUMO

The widespread use and release of plastics in nature have raised global concerns about their impact on public health and the environment. While much research has been conducted on macro- and micro-sized plastics, the fate of nanoscale plastics remains unexplored. In this study, the aggregation kinetics and stability of polyethylene and polystyrene nanoscale plastics were investigated over a wide range of aquatic chemistries (pH, salt types (NaCl, CaCl2, MgCl2), ionic strength) relevant to the natural environment. Results showed that salt types and ionic strength had significant effects on the stability of both polyethylene and polystyrene nanoscale plastics, while pH had none. Aggregation and stability of both polyethylene and polystyrene nanoscale plastics in the aquatic environment followed colloidal theory (DLVO theory and Schulze-Hardy rule), similar to other colloidal particles. The critical coagulation concentration (CCC) values of polyethylene nanoscale plastics were lower for CaCl2 (0.1 mM) compared to NaCl (80 mM) and MgCl2 (3 mM). Similarly, CCC values of polystyrene nanospheres were 10 mM for CaCl2, 800 mM for NaCl and 25 mM for MgCl2. It implies that CaCl2 destabilized both polyethylene and polystyrene nanoscale plastics more aggressively than NaCl and MgCl2. Moreover, polystyrene nanospheres are more stable in the aquatic environment than polyethylene nanoscale plastics. However, natural organic matter improved the stability of polyethylene nanoscale plastics in water primarily due to steric repulsion, increasing CCC values to 0.4 mM, 120 mM and 8 mM for CaCl2, NaCl and MgCl2 respectively. Stability studies with various water conditions demonstrated that polyethylene nanoscale plastics will be fairly stable in the natural surface waters. Conversely, synthetic surface water, wastewater, seawater and groundwater rapidly destabilized polyethylene nanoscale plastics. Overall, our findings indicate that significant aqueous transport of nanoscale plastics will be possible in natural surface waters.


Assuntos
Eletrólitos , Plásticos , Cinética , Polietileno , Poliestirenos
18.
Food Chem ; 309: 125789, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704073

RESUMO

In this study, the development of an electroanalytical assay based on square wave voltammetry technique for determining sesamol (Ses) in sesame oil samples is described. The influence of various factors such as pH of the supporting electrolyte, its composition, and SW (square wave) parameters was studied. Linearity of the peak current depended on the concentration of Ses in the range from 3.0 to 140.0 µmol L-1 with a limit of detection of 0.71 µmol L-1. Furthermore, the cyclic voltammetric behavior of Ses and the effects of scan rate and pH on the peak current and peak potential of Ses were determined. Moreover, the electrode process was found to be diffusion-controlled. The proposed methodology was successfully applied for determining Ses in commercial sesame oil samples. The obtained results were in good agreement with the results from the HPLC-UV reference method.


Assuntos
Benzodioxóis/análise , Fenóis/análise , Potenciometria , Óleo de Gergelim/química , Carbono/química , Eletrodos , Eletrólitos/química , Concentração de Íons de Hidrogênio , Limite de Detecção
19.
Chemosphere ; 245: 125557, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31862555

RESUMO

The use of CO2 as a C1 carbon source for synthesis is raising increasing attention both as a strategy to bring value to carbon dioxide capture technologies and a sustainable approach towards chemicals and energy. The presented results focus on the application of electrochemical methods to incorporate CO2 into organic compounds using ionic liquids as electrolytes, which provides a green alternative to the formation of C-C bonds. In this sense, the current manuscript shows that Naproxen (6-Methoxy-α-methyl-2-naphthaleneacetic acid) can be synthetizing in high yield (89%) and conversion rates (90%) through an electrocarboxylation process using CO2 and ionic liquids. The role of the cathode and solvent, which can potentially enhance the synthesis, is also discussed. The "green" route described in the current work would open a new sustainable strategy for the electrochemical production of pharmaceutical compounds.


Assuntos
Dióxido de Carbono/química , Líquidos Iônicos/química , Naproxeno/química , Técnicas Eletroquímicas/métodos , Eletrodos , Eletrólitos , Compostos Orgânicos , Solventes/química
20.
Chemosphere ; 246: 125677, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31884230

RESUMO

In this study, WO3 nanostructures were synthesized by the electrochemical anodization technique to use them on the degradation of persistent organic compounds such as the pesticide fenamiphos. The acids electrolyte used during the anodization were two different: 1.5 M H2SO4 - 0.05 M H2O2 and 1.5 M CH4O3S - 0.05 M H2O2. Once the samples have been manufactured, they have been subjected to different tests to analyze the properties of the nanostructures. With Field Emission Scanning Electron Microscopy (FE-SEM) the samples have been examined morphologically, their composition and crystallinity has been studied through Raman Spectroscopy and their photoelectrochemical behaviour by Photoelectrochemical Impedance Spectroscopy (PEIS). Finally, degradation tests have been carried out using the technique known as photoelectrocatalysis (PEC). The conditions that were applied in this technique were a potential of 1 VAg/AgCl and simulated solar illumination. The degradation process was monitored by UV-Visible and High-Performance liquid Chromatography (HPLC) to control the course of the experiment. The nanostructures obtained with 1.5 M CH4O3S - 0.05 M H2O2 electrolyte showed a better photoelectrochemical behaviour than nanostructures synthesized with 1.5 M H2SO4 - 0.05 M H2O2. The fenamiphos degradation was achieved at 2 h of experiment and the intermediate formation was noticed at 1 h of PEC experiment.


Assuntos
Nanotubos/química , Compostos Organofosforados/química , Óxidos/química , Praguicidas/química , Tungstênio/química , Eletrólitos , Peróxido de Hidrogênio , Microscopia Eletrônica de Varredura , Modelos Químicos , Nanoestruturas/química , Processos Fotoquímicos , Luz Solar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA