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1.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(5): 595-600, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32576354

RESUMO

OBJECTIVE: To investigate the status of regional citrate anticoagulation (RCA) in continuous renal replacement therapy (CRRT) in emergency department. METHODS: Participants of a national emergency conference from August 1st to August 4th in 2019 from hospitals of different levels in different regions were interviewed by online questionnaire to collect data about the current status and limitations of the application of RCA in emergency CRRT by convenient sampling. RESULTS: Totally 407 questionnaires were collected through internet, and the completeness of the answers was as high as 100%. Twenty-three responses with logic errors were excluded, and 384 questionnaires were finally retrieved, with an effective rate of 94.35%. Representatives from 29 provinces, autonomous regions and municipalities directly under the Central Government participated in the questionnaire survey, and the hospitals in which they worked were mainly class III grade A [70.31% (270/384)]. The survey showed that 61.46% (236/384) of the emergency departments could carry out CRRT independently. There were less than 10 CRRT cases per month in most emergency departments [52.87% (166/314)]. In the emergency departments where CRRT were carried out, heparin was a widely used and well-applied anticoagulant [82.17% (258/314)], and 199 emergency departments (63.38%) were proficient in RCA. In clinical practice, heparin [49.68% (156/314)] was preferred to RCA [25.80% (81/314)] and low molecular weight heparin [23.56% (74/384)]. In the emergency departments where RCA could be used skillfully, 4% sodium citrate was the main regional anticoagulant [68.34% (136/199)]. Anticoagulation protocol came from different sources, most of which were from nephrology or dialysis center (29.65%). Most departments could adjust the ionized calcium before the filter to the target safety level [0.9-1.2 mmol/L, 88.94% (177/199)], and adjust the ionized calcium after the filter to the target ideal anticoagulation level [0.2-0.4 mmol/L, 93.47% (186/199)] within 4 hours. The common complications that emergency physicians concerned were accumulation of citrate [58.29% (116/199)], metabolic alkalosis [54.77% (109/199)] and metabolic acidosis [37.19% (74/199)]. In 281 emergency departments that could not use RCA, there were kinds of factors that limited the use of citrate, such as higher cost than heparin (31.67%), unskilled personnel (21.00%), limited source of citrate (17.08%), concerns of complications (11.74%). At present, the substitution fluids used in clinical practice were mainly the commercial products (45.54%). In most cases, emergency CRRT filters had a life span of 12-23 hours (39.49%). CONCLUSIONS: The use of RCA in domestic emergency CRRT is low. Compared with the international peers, we are still lacking of adequate understanding of RCA. Therefore, it is necessary to develop an anticoagulation protocol of RCA for emergency departments in China, and promote training of CRRT.


Assuntos
Terapia de Substituição Renal Contínua , Anticoagulantes , China , Ácido Cítrico , Serviço Hospitalar de Emergência , Inquéritos e Questionários
2.
Water Sci Technol ; 81(3): 491-498, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32385202

RESUMO

Constructing new cation exchange membranes (CEM) has been regarded as an easy and effective approach to improving the capacitive deionization (CDI) system. In this study, a new method of fabrication of CEM was introduced by crosslinking sulfosuccinic acid (SSA) and citric acid (CA). The SSA and CA were crosslinked with polyvinyl alcohol (PVA) to fabricate CEMs in a series of conditions. The ion transference number for each fabricated membrane was tested to select the optimal recipe. The membrane fabricated by the selected method was then tested in the CDI system and the results show that the total percentage of SSA could be reduced from 5% to 1% by adding 5 g of non-toxic and inexpensive CA. The cost of preparing the membrane also decreased from US$0.18 per square meter to US$0.03. The adsorption capacity and the charge efficiency of membrane capacitive deionization system (MCDI) coated with a PVA/SSA/CA layer (mass ratio 10:1:5) was compared with the normal CDI and the MCDI coated with the original membrane (PVA:SSA = 19:5), which is named O-MCDI). The results show that with the modified membrane, the adsorption capacity and the charge efficiency can be enhanced by 18% and 28% compared with the CDI. In addition, although the cost is reduced, the desalination efficiency is still guaranteed. The adsorption capacity and charge efficiency are still increased by about 3% compared with the O-MCDI.


Assuntos
Álcool de Polivinil , Purificação da Água , Adsorção , Carbono , Cátions , Ácido Cítrico , Eletrodos , Membranas Artificiais , Cloreto de Sódio
3.
Bioresour Technol ; 307: 123290, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32265091

RESUMO

To study the effects of citric acid on fermentation process of Amomum villosum silage, A. villosum was ensiled without or with 1%, 2% citric acid and fermentation parameters and bacterial diversity were analyzed after 3, 7, 14, 30 days ensiling, respectively. Citric acid treated silages had lower dry matter loss (1.83% vs 2.23%), pH (3.84 vs 6.02), ammonia-N (0.33 vs 1.79 g/kg DM) and coliform bacteria number (<2.00 vs 7.27 log10 CFU/g FM) than the control after 30 days ensiling. The relative abundance of lactic acid bacteria, Pediococcus and Lactobacillus increased, whereas undesirable microorganisms like Enterobacter, Escherichia-Shigella and Pantoea decreased in citric acid treated A. villosum silage. These results indicated that quality A. villosum silage could be obtained by citric acid addition.


Assuntos
Amomum , Silagem , Bactérias , Ácido Cítrico , Fermentação
4.
Bioresour Technol ; 309: 123317, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32305014

RESUMO

In this study, the potential of the co-generation of hydrolytic enzymes in the biorefinery plant for citric acid fermentation was investigated. Aspergillus niger B60 mycelium along with the solid residue after the recovery of sugars from white pomace (WP') were recycled from citric acid fermentation. A mixture design was used to determine the optimum ternary feedstock mixture composed of WP' (15%), red grape pomace (15%) and wheat bran (70%) that produced the target enzymes with high activities, which were compared to those from pure feedstocks. Maximum carboxymethyl cellulase, polygalacturonase, amylase, xylanase and acid protease activities obtained through solid-state fermentation (120 h, 30 °C) of the feedstock mixture were 668 IU/g, 3,151 IU/g, 1,099 IU/g, 579 IU/g and 204 IU/g (dry mass basis), respectively. The system was successfully simulated in SuperPro Designer. Results showed that the enzymes production process serves as the main contributor to the profitability of the biorefinery plant.


Assuntos
Aspergillus niger , Vitis , Ácido Cítrico , Fibras na Dieta , Estudos de Viabilidade , Fermentação
5.
Nature ; 579(7800): 586-591, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32214246

RESUMO

Consumption of fructose has risen markedly in recent decades owing to the use of sucrose and high-fructose corn syrup in beverages and processed foods1, and this has contributed to increasing rates of obesity and non-alcoholic fatty liver disease2-4. Fructose intake triggers de novo lipogenesis in the liver4-6, in which carbon precursors of acetyl-CoA are converted into fatty acids. The ATP citrate lyase (ACLY) enzyme cleaves cytosolic citrate to generate acetyl-CoA, and is upregulated after consumption of carbohydrates7. Clinical trials are currently pursuing the inhibition of ACLY as a treatment for metabolic diseases8. However, the route from dietary fructose to hepatic acetyl-CoA and lipids remains unknown. Here, using in vivo isotope tracing, we show that liver-specific deletion of Acly in mice is unable to suppress fructose-induced lipogenesis. Dietary fructose is converted to acetate by the gut microbiota9, and this supplies lipogenic acetyl-CoA independently of ACLY10. Depletion of the microbiota or silencing of hepatic ACSS2, which generates acetyl-CoA from acetate, potently suppresses the conversion of bolus fructose into hepatic acetyl-CoA and fatty acids. When fructose is consumed more gradually to facilitate its absorption in the small intestine, both citrate cleavage in hepatocytes and microorganism-derived acetate contribute to lipogenesis. By contrast, the lipogenic transcriptional program is activated in response to fructose in a manner that is independent of acetyl-CoA metabolism. These data reveal a two-pronged mechanism that regulates hepatic lipogenesis, in which fructolysis within hepatocytes provides a signal to promote the expression of lipogenic genes, and the generation of microbial acetate feeds lipogenic pools of acetyl-CoA.


Assuntos
Acetatos/metabolismo , Açúcares da Dieta/metabolismo , Frutose/metabolismo , Microbioma Gastrointestinal/fisiologia , Lipogênese , Fígado/metabolismo , ATP Citrato (pro-S)-Liase/deficiência , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Acetato-CoA Ligase/deficiência , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetilcoenzima A/metabolismo , Animais , Ácido Cítrico/metabolismo , Açúcares da Dieta/administração & dosagem , Açúcares da Dieta/farmacologia , Ácidos Graxos/metabolismo , Frutose/administração & dosagem , Frutose/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Marcação por Isótopo , Lipogênese/efeitos dos fármacos , Lipogênese/genética , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Especificidade por Substrato
6.
Chemosphere ; 251: 126331, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32145572

RESUMO

The present study deals with the potential application of Purolite S957 and Diphonix Resin® for the removal of rare earth elements from aqueous liquors as a result of the extraction of spent Ni-MH batteries in the presence of citric acid. The effects of the metal ion and the citric acid ratio, pH, ion exchanger dose, contact time, initial concentration and temperature were studied using the batch technique. The Langmuir and Freundlich adsorption isotherm models were used for the description of the adsorption process. The equilibrium adsorption data were fitted using the pseudo first order, pseudo second order, intraparticle diffusion, Boyd, film diffusion and Dumwald-Wagner models. The maximum adsorption capacity q0 obtained from the Langmuir isotherm was found to be 46.63 mg/g for Ni(II) and 60.75 mg/g for La(III) on Purolite S957 as well as 46.55 mg/g for Ni(II) and 60.12 mg/g for La(III) on Diphonix Resin®. The kinetics followed the pseudo second order reaction. Based on the Weber-Morris model the adsorption process proved to proceed in two stages. Based on the Boyd model the rate controlling steps were film and intraparticle diffusions. The adsorption process was spontaneous and endothermic in nature. Reusability of ion exchangers in the desorption studies was also evaluated as a sustainable approach. The physicochemical properties of Purolite S957 and Diphonix Resin® were studied using the ASAP analysis, optical and scanning electron microscopy, potentiometric titration, pHPZC and FT-IR as well as XPS analysis.


Assuntos
Ácido Cítrico/química , Troca Iônica , Metais/química , Poluentes Químicos da Água/química , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Íons , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termodinâmica , Poluentes Químicos da Água/análise
7.
Nat Rev Urol ; 17(4): 214-231, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32112053

RESUMO

Anabolic metabolism mediated by aberrant growth factor signalling fuels tumour growth and progression. The first biochemical descriptions of the altered metabolic nature of solid tumours were reported by Otto Warburg almost a century ago. Now, the study of tumour metabolism is being redefined by the development of new molecular tools, tumour modelling systems and precise instrumentation together with important advances in genetics, cell biology and spectroscopy. In contrast to Warburg's original hypothesis, accumulating evidence demonstrates a critical role for mitochondrial metabolism and substantial variation in the way in which different tumours metabolize nutrients to generate biomass. Furthermore, computational and experimental approaches suggest a dominant influence of the tissue-of-origin in shaping the metabolic reprogramming that enables tumour growth. For example, the unique metabolic properties of prostate adenocarcinoma are likely to stem from the distinct metabolism of the prostatic epithelium from which it emerges. Normal prostatic epithelium employs comparatively glycolytic metabolism to sustain physiological citrate secretion, whereas prostate adenocarcinoma consumes citrate to power oxidative phosphorylation and fuel lipogenesis, enabling tumour progression through metabolic reprogramming. Current data suggest that the distinct metabolic aberrations in prostate adenocarcinoma are driven by the androgen receptor, providing opportunities for functional metabolic imaging and novel therapeutic interventions that will be complementary to existing diagnostic and treatment options.


Assuntos
Adenocarcinoma/metabolismo , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Proliferação de Células , Ácido Cítrico/metabolismo , Ciclo do Ácido Cítrico , Glicólise , Humanos , Lipogênese , Masculino , Redes e Vias Metabólicas , Fosforilação Oxidativa , Microambiente Tumoral
8.
Bioresour Technol ; 302: 122859, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32018085

RESUMO

This paper investigated the effects of citric acid (CA) on extracellular polymer destruction and cell lysis in sludge at different initial pH by measuring capillary suction time (CST), extracellular polymeric substances (EPS) and intracellular bound water. The results indicated that under CA concentration at 0.05 g/g suspended solids (SS) and initial pH 4, the CST value decreased from 175.5 s to 112.3 s, slime extracellular polymeric substances (S-EPS) and loosely bound EPS (LB-EPS) content respectively to increase from 4.92 to 41.43, 2.27 to 5.49 mg/g volatile suspended solids (Vss), while tightly bound EPS (TB-EPS) content to decrease from 12.35 to 5.01 mg/g (Vss), which suggested CA could disrupt outer EPS effectively. Intracellular bound water content decreased from 1.23 g/g to 0.41 g/g dry solid (DS). As a result, CA could release intracellular bound water effectively, thereby improving sludge dewatering degree.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Ácido Cítrico , Matriz Extracelular de Substâncias Poliméricas , Concentração de Íons de Hidrogênio , Água
9.
Environ Pollut ; 260: 114025, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32004964

RESUMO

Odontarrhena muralis is one of the most promissing plant species for Ni phytomining, and soil amendments can further increase its Ni phytoextraction ability. Here we investigated whether Ni phytomining/phytoremediation using this Ni hyperaccumulator can benefit from applying citric acid to a serpentine soil that is naturally enriched in Ni (>1000 mg kg-1). Synchrotron micro X-ray fluorescence (µ-SXRF) was used to image Ni and other metal distributions in whole fresh leaves of O. muralis. Leaf Ni accumulation in plants grown on citric acid-amended soil increased up to 55% while Co, Cr, Fe, Mn, and Zn concentrations were 4-, 14-, 6-, 7- and 1.3-fold higher than the control treatment. O. muralis presented high bioconcentration factors (leaf to soil concentration ratio) to Ni and Zn whereas Cr was seemingly excluded from uptake. The µ-SXRF images showed a uniform distribution of Ni, preferential localization of Co in the leaf tip, and clear concentration of Mn in the base of trichomes. The citric acid treatments strongly increased the Co fluoerescence intensity in the leaf tip and altered the spatial distribution of Mn across the leaf, but there was no difference in Ni fluorescence counts between the trichome-base region and the bulk leaf. Our data from a serpentine soil suggests that citrate treatment enhances Ni uptake, but Co is excreted from leaves even in low leaf concentrations, which can make Co phytoming using O. muralis unfeasible in natural serpentine soils.


Assuntos
Biodegradação Ambiental , Brassicaceae , Metais/metabolismo , Poluentes do Solo , Ácido Cítrico , Metais Pesados , Níquel , Solo
10.
Food Chem ; 315: 126217, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32007812

RESUMO

This study investigated the direct citric acid hydrolysis extraction method to optimize phytosterols extraction from hickory husk. Single factor experiments followed by a three-level three-factor Box-Behnken experiments were performed. The optimal extraction parameters were determined as: pH of 2.0, liquid-to-solid ratio of 17.12: 1 mL/g, and temperature of 55.81 °C. Practical experiments were carried out in triplicate, and subsequently yielded phytosterols of 912.452 ± 17.452 µg/g DW, in good consistence with the predicted extraction yield of 902.874 µg/g DW. The conductivity of the extract was also found to play effective role under direct citric acid hydrolysis and recorded 36.30 ± 1.08 µs/cm at optimum extraction condition. ß-Sitosterol stigmasterol, campsterol, ergosterol and lupeol were detected as main PSs and triterpenoids in hickory husk using UPLC-Triple-TOF/MS. Finally, the comparison between direct hydrolysis extraction and traditional solvent extraction showed that this new method was more effective and eco-friendlier to extract both free and conjugated phytosterols.


Assuntos
Carya/química , Modelos Teóricos , Fitosteróis/isolamento & purificação , Triterpenos/isolamento & purificação , Ácido Cítrico/química , Ergosterol/química , Ergosterol/isolamento & purificação , Concentração de Íons de Hidrogênio , Hidrólise , Triterpenos Pentacíclicos/química , Triterpenos Pentacíclicos/isolamento & purificação , Fitosteróis/química , Sitosteroides/química , Sitosteroides/isolamento & purificação , Estigmasterol/química , Estigmasterol/isolamento & purificação , Triterpenos/química
11.
Nat Commun ; 11(1): 698, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32019928

RESUMO

Profound metabolic changes are characteristic of macrophages during classical activation and have been implicated in this phenotype. Here we demonstrate that nitric oxide (NO) produced by murine macrophages is responsible for TCA cycle alterations and citrate accumulation associated with polarization. 13C tracing and mitochondrial respiration experiments map NO-mediated suppression of metabolism to mitochondrial aconitase (ACO2). Moreover, we find that inflammatory macrophages reroute pyruvate away from pyruvate dehydrogenase (PDH) in an NO-dependent and hypoxia-inducible factor 1α (Hif1α)-independent manner, thereby promoting glutamine-based anaplerosis. Ultimately, NO accumulation leads to suppression and loss of mitochondrial electron transport chain (ETC) complexes. Our data reveal that macrophages metabolic rewiring, in vitro and in vivo, is dependent on NO targeting specific pathways, resulting in reduced production of inflammatory mediators. Our findings require modification to current models of macrophage biology and demonstrate that reprogramming of metabolism should be considered a result rather than a mediator of inflammatory polarization.


Assuntos
Aconitato Hidratase/metabolismo , Macrófagos/enzimologia , Óxido Nítrico/metabolismo , Quinase Piruvato Desidrogenase (Transferência de Acetil)/metabolismo , Aconitato Hidratase/genética , Animais , Ácido Cítrico/metabolismo , Ciclo do Ácido Cítrico , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/genética , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Quinase Piruvato Desidrogenase (Transferência de Acetil)/genética , Ácido Pirúvico/metabolismo
12.
Chemosphere ; 248: 126029, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32035385

RESUMO

The use of electrokinetic Fenton (EK Fenton) process, as promising soil remediation approach, was investigated by using an iron electrode with different supporting electrolytes (tap water, H2O2, and citric acid) to depollute soil spiked with petroleum where kaolin was selected as low hydraulic conductivity. The results clearly confirm that, the combination of electrokinetic remediation (EK) and Fenton technologies, is an efficient oxidizing approach for removing hydrocarbons from this kind of soil. In fact, the electrokinetic Fenton reactions and the control of the soil pH conditions by adding citric acid enhanced the oxidation process because the addition of the H2O2 with iron electrode resulted in higher removal efficiencies (89%) for total petroleum hydrocarbons (TPHs). These figures allowed to confirm that EK Fenton process with pH control contributed for the transport of H2O2 and Fe2+ ions in the soil by electromigration and eletro-osmotic phenomena. Conversely, no control of pH conditions when only EK was applied, achieved lower hydrocarbons removal (27%) after 15 d of treatment due to the precipitation of iron ions. Finally, the efficiency of the EK Fenton remediation prevented the generation of secondary effluent with higher organic content, avoiding its treatment by other advanced oxidation process.


Assuntos
Recuperação e Remediação Ambiental/métodos , Poluição por Petróleo , Poluentes do Solo/química , Ácido Cítrico/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Recuperação e Remediação Ambiental/instrumentação , Hidrocarbonetos/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Ferro/química , Caulim/química , Osmose , Oxirredução , Solo/química
14.
Food Chem ; 317: 126457, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32106009

RESUMO

In this work, a novel, selective and sensitive fluorescent probe (sulfur doped graphene quantum dots, SGQDs) was designed for real-time detection of quercetin in red wine samples. SGQDs were synthesized by pyrolyzing citric acid (CA) and 3-Mercaptopropionic acid (MPA) and characterized through advanced techniques. It was observed that fluorescence intensity of SGQDs could be substantially quenched by the addition of quercetin through inner filter effect (IFE) mechanism. Additionally, a visual color change (colorless to light yellow) was also noticed after addition of quercetin into a solution of SGQDs. The change in SGQDs fluorescence intensity with varying quercetin content revealed good linearity in the 0-50.0 µM range with regression coefficient of 0.9943 and a lowest detection limit of 0.006 µg/mL. To authenticate the real-time application of SGQDs as a potential fluorescent probe, red wine samples having different quercetin concentrations were used for quantitative analysis, after the optimization of several analytical parameters.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos/química , Quercetina/análise , Enxofre/química , Ácido 3-Mercaptopropiônico/química , Ácido Cítrico/química , Cor , Flavonoides/química , Fluorescência , Análise de Alimentos/métodos , Grafite/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Solventes/química , Espectrometria de Fluorescência/métodos , Vinho/análise
15.
Aquat Toxicol ; 221: 105445, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32078886

RESUMO

Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) - citrate and polyvinylpyrrolidone (PVP) coated - on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group. AuNPs differentially affected several metabolic pathways in S. aurata liver cells. Among the affected proteins were those related to cytoskeleton and cell structure, gluconeogenesis, amino acids metabolism and several processes related to protein activity (protein synthesis, catabolism, folding and transport). The increased abundance of proteins associated with energy metabolism (ATP synthase subunit beta), stress response (94 kDa glucose-regulated protein) and cytoskeleton structure (actins and tubulins) may represent the first signs of cellular oxidative stress induced by AuNPs. Although higher gold accumulation was found in the liver of S. aurata exposed to 7 nm PVP-AuNPs, the 7 nm cAuNPs were more bioactive, inducing more effects in liver proteome. Gold accumulated more in the spleen than in the other assessed tissues of S. aurata exposed to AuNPs, highlighting its potential role on the elimination of these NPs.


Assuntos
Ouro/toxicidade , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Proteoma/metabolismo , Dourada/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Ácido Cítrico/química , Fígado/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Povidona/química , Proteômica , Propriedades de Superfície
16.
PLoS One ; 15(1): e0227497, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923242

RESUMO

BACKGROUND: Oral magnesium for leg cramps treatment in pregnancy is a controversial issue according to recent Cochrane systematic review. This study aims to evaluate the efficacy of Mg++ supplementation in leg cramps treatment in pregnancy. METHODS: This observational clinical trial studied 132 pregnant women with leg cramps in the first trimester of pregnancy. At baseline, 74 (56.3%) had two leg cramps episodes per week, 28 (21.1%) three episodes, 13 (9.8%) four episodes and 9 (6.8%) five or more episodes. They were randomized 1:1 to 300 mg/day of oral Mg++ citrate (n = 66) or placebo (n = 66). The primary outcome was the frequency of leg cramps episodes per week reported by pregnant women. Secondary outcomes were the ocurrence of leg cramps and oral magnesium side effects. RESULTS: 130 pregnant women completed the study and the two groups were comparable according to some sociodemographic and clinical characteristics. After 4 weeks of intervention it was observed a 28.4% (39/132) (CI 95%: 20.9-37.0) reduction of leg cramps in all participants and no difference between the two groups was found; reduction of 27.2% (18/66) (CI 95%: 17.0-39.6) in Mg++ group and 32.8% (21/66) (CI 95%: 21.6-45.7) in the placebo group. The OR of leg cramps was 1.3 (CI 95%: 0.6-2.9), p = 0.527, taking the placebo group as reference. Among pregnant women who remained with leg cramps the mean of leg cramps episodes per week showed no significance difference between the Mg++ and placebo groups; t-student test: p = 0.408. Four pregnant women showed gastrointestinal side effects; 2 in each group had nauseas and diarrhoea. CONCLUSION: Oral magnesium supplementation during pregnancy did not reduce the ocurrence and frequency of episodes of leg cramps.


Assuntos
Ácido Cítrico/administração & dosagem , Cãibra Muscular/prevenção & controle , Compostos Organometálicos/administração & dosagem , Administração Oral , Adulto , Ácido Cítrico/efeitos adversos , Suplementos Nutricionais , Esquema de Medicação , Feminino , Gastroenteropatias/etiologia , Humanos , Compostos Organometálicos/efeitos adversos , Efeito Placebo , Gravidez , Adulto Jovem
17.
J Dairy Sci ; 103(3): 2089-2097, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954576

RESUMO

In the present study, the sensory characteristics and the volatile organic compound (VOC) profiles of high-moisture mozzarella made by different acidification techniques were compared. The cheeses were manufactured at the same dairy by fermentation by autochthonous natural whey starter (traditional backslopping method) and direct acidification with citric acid (the most used industrial technology). Three cheesemaking trials were performed from February to June using raw milk from a single farm. The mozzarella samples were subjected to assessment of the chemical, microbiological, and sensory characteristics and to VOC analysis by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry. The relevant microbiological differences found between the 2 types of products were reflected in different sensory and VOC profiles. The cheeses were clearly discriminated by the panel, and traditional mozzarella had higher intensity attributes. The most discriminating descriptors were elasticity, overall odor and taste intensity, sour milk and fruity/vegetable odors, sour taste, and aftertaste. Even though some variability was observed among the trials, the VOC profile of traditional product was always much more complex than that obtained by direct acidification. In both products the carbonyl compounds were the most abundant chemical class, accounting for about 50% of the total. In detail, 51 compounds were identified in the entire set of samples, and their contribution to cheese aroma was roughly estimated by calculating the odor activity values on the basis of the odor thresholds available in the literature. The results allowed hypothesizing that only 12 of them could play a primary role. The most important among the odor-active compounds was 3-methyl-butanal that can both derive from metabolism of lactic acid bacteria and yeasts. The results of the study may be very useful in view of European Union PDO labeling of the traditional product, in terms of protecting it from imitations.


Assuntos
Queijo , Paladar , Compostos Orgânicos Voláteis/análise , Animais , Queijo/análise , Ácido Cítrico , Fermentação , Aditivos Alimentares , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Odorantes/análise , Microextração em Fase Sólida
18.
Talanta ; 209: 120593, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892006

RESUMO

The impact of preanalytical sample handling on lipid stability has been assessed in human plasma using targeted LC-MS/MS quantification of endocannabinoids, sphingolipids and LPA, complemented by non-targeted lipidomics screening with LC-QTOFMS. The study involved incubation of whole blood and plasma from healthy volunteers at room temperature or in ice water for time periods ranging from 20 min to 24 h. The impact of two different anticoagulants, K3EDTA and sodium fluoride/citrate, on lipid stability was evaluated. It was found that the concentrations determined for several endogenous lipids vary when whole blood and plasma samples are processed at room temperature, whereas the concentrations of most lipids were stable for 4 h in ice water. Surprisingly, the detected amounts of endocannabinoids 1- and 2-arachidonoyl glycerol and arachidonoyl ethanolamide increased markedly by 60, 95, and 30% in K3EDTA whole blood after storage in ice water for only 20 min. When using sodium fluoride/citrate blood collection tubes, the stability of several lipids, including that of the endocannabinoids, was improved. Accordingly, it is absolutely necessary to keep the blood sampling and plasma processing time below 1 h to avoid ex-vivo formation of endocannabinoids. It is worth mentioning that baseline lipid levels differ when using K3EDTA or sodium fluoride/citrate blood sampling tubes, which emphasizes the importance of traceability of reported plasma concentrations to the used anticoagulant.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Endocanabinoides/sangue , Lipidômica/métodos , Lisofosfolipídeos/sangue , Esfingolipídeos/sangue , Adulto , Cromatografia Líquida/métodos , Ácido Cítrico/química , Feminino , Fluoretos/química , Humanos , Masculino , Espectrometria de Massas/métodos
19.
Chemosphere ; 247: 125936, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978664

RESUMO

Silver nanoparticles (AgNPs) can gradually accumulate in algae to exert their toxicity; however, there is little knowledge about their bioaccumulation dynamics. For the first time, this study reports the effect of surface charge of AgNPs on their bioaccumulation dynamics in freshwater algae (Chlorella vulgaris) using biodynamic modeling. Polyethylene-coated AgNPs (PEI-AgNPs) and citrate-coated AgNPs (Cit-AgNPs) were selected as positively and negatively charged AgNPs, i.e., P-AgNPs and N-AgNPs, respectively. Their uptake and elimination dynamics were investigated at a concentration of 50% inhibition of growth rate values (EC50) and 10% inhibition of growth rate values (EC10). The one-component model can generally well simulate the algal uptake and elimination kinetics of N-AgNPs but not of P-AgNPs. At both concentrations, the uptake rate constants (ku) for P-AgNPs were ∼20 times higher than that for N-AgNPs. The parameters of biphasic elimination kinetics revealed that P-AgNPs were eliminated faster than N-AgNPs during depuration compared to in subsequent processes. Compared with N-AgNPs, extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and dark-field imaging revealed that P-AgNPs can be rapidly absorbed on the algal cell surface membrane owing to their remarkably lower energy barrier between algal cells, resulting in a faster adsorption/uptake process and aggregation of algal cells. Our results clearly demonstrate that the AgNPs exhibited surface charge-dependent bioaccumulation dynamics in algal cells. Thus, AgNP surface charge primarily influences the AgNP accumulation dynamics in algal cells.


Assuntos
Chlorella vulgaris/metabolismo , Nanopartículas Metálicas/análise , Prata/metabolismo , Adsorção , Bioacumulação , Chlorella vulgaris/efeitos dos fármacos , Ácido Cítrico/metabolismo , Água Doce
20.
Nat Commun ; 11(1): 458, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974386

RESUMO

Assembly of the peptidoglycan is crucial in maintaining viability of bacteria and in defining bacterial cell shapes, both of which are important for existence in the ecological niche that the organism occupies. Here, eight crystal structures for a member of the cell-shape-determining class of Campylobacter jejuni, the peptidoglycan peptidase 3 (Pgp3), are reported. Characterization of the turnover chemistry of Pgp3 reveals cell wall D,D-endopeptidase and D,D-carboxypeptidase activities. Catalysis is accompanied by large conformational changes upon peptidoglycan binding, whereby a loop regulates access to the active site. Furthermore, prior hydrolysis of the crosslinked peptide stem from the saccharide backbone of the peptidoglycan on one side is a pre-requisite for its recognition and turnover by Pgp3. These analyses reveal the noncanonical nature of the transformations at the core of the events that define the morphological shape for C. jejuni as an intestinal pathogen.


Assuntos
Campylobacter jejuni/metabolismo , Endopeptidases/química , Endopeptidases/metabolismo , Peptidoglicano/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Ácido Cítrico/química , Ácido Cítrico/metabolismo , Cristalografia por Raios X , Endopeptidases/genética , Hidrólise , Metaloproteases/química , Modelos Moleculares , Mutação , Peptidoglicano/química , Conformação Proteica , Fatores de Virulência/química
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