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1.
Rech Soins Infirm ; (141): 78-86, 2020 06.
Artigo em Francês | MEDLINE | ID: mdl-32988194

RESUMO

Despite its proven dangers, the ward stock drug distribution system predominates in French hospitals. This system allows 12 million injectable ampoules of concentrated potassium chloride to circulate uncontrolled each year. Such a situation is absurd for the following reasons : 1) injected by mistake, concentrated potassium kills within seconds ; 2) the true incidence of potassium-related fatalities and incidents is unknown ; 3) fatal intravenous injection of potassium produces no specific anatomical changes and subtle, if any, findings at autopsy ; 4) it is used for capital punishment by lethal injection in various countries ; and 5) healthcare worker serial killers benefit from the fact that potassium is not identifiable in post-mortem examinations and that investigations to find the murderer are complex and of uncertain outcome. Other medications classed as high-risk have similar characteristics to those of concentrated potassium solutions. Injectable potassium can therefore be regarded as emblematic of the lack of safety of the drug use process in French hospitals. The priority measure to protect patients from this deadly risk is to remove these drugs from uncontrolled ward stocks and to provide premixed potassium solutions. Evidence of the increased safety of the unit dose drug dispensing system should compel health policy makers to systematically implement it, thus bringing the drug use process into compliance with existing French and European regulations.


Assuntos
Segurança do Paciente/normas , Cloreto de Potássio/envenenamento , Controle de Medicamentos e Entorpecentes , França , Hospitais , Humanos , Injeções , Cloreto de Potássio/administração & dosagem , Cloreto de Potássio/química
2.
Food Chem ; 332: 127414, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615379

RESUMO

The reasons for the change in the water retention capability of salted pork caused by potassium chloride (KCl) instead of sodium chloride (NaCl) were investigated. Accompanied by the gradually increased substitution rate of KCl, the oxidative degradation of protein, water content, water activity (aw), gap, as well as water loss in salted pork were increased, and the results showed significant differences (p < 0.05). LF-NMR results indicated that NaCl was replaced by KCl, which can observably increased the mobility of water in the salted pork (p < 0.05). All indexes showed excellent correlation. NaCl was replaced by KCl, which affected the water retention capability of salted pork, because K+ promoted changes in the meat's physicochemical properties. The KCl replacement group presented higher water content, while displayed lower water retention capability.


Assuntos
Carne/análise , Cloreto de Potássio/química , Água/química , Animais , Manipulação de Alimentos , Espectroscopia de Ressonância Magnética , Oxirredução , Proteínas/química , Cloreto de Sódio/química , Suínos
3.
Food Chem ; 331: 127289, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569966

RESUMO

Konjac glucomannan (KGM) electrogels were successfully prepared under alternating current (AC) in the presence of potassium chloride (KCl). The structure of the gels was studied using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM). A single-factor experiment was performed to optimize the preparation of the gels. Our results showed that KGM was degraded under AC and partially deacetylated. KGM and KCl formed the structure , and electrogels with porous structures retained some acetyl groups. Furthermore, as the KCl concentrations, voltages, time, and KGM concentrations increased, the viscoelastic moduli of the gels increased; the moduli decreased when the KCl concentrations, voltages, and time exceeded critical values.


Assuntos
Mananas/química , Microscopia Eletrônica de Varredura , Cloreto de Potássio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Condutividade Elétrica
4.
J Appl Oral Sci ; 28: e20190516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236357

RESUMO

INTRODUCTION: This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). METHODOLOGY: Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). RESULTS: CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. CONCLUSIONS: CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Hidróxido de Cálcio/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Pirrolidinonas/farmacologia , Irrigantes do Canal Radicular/farmacologia , Análise de Variância , Animais , Cloreto de Cálcio/química , Cloreto de Cálcio/farmacologia , Hidróxido de Cálcio/química , Bovinos , Contagem de Colônia Microbiana , Combinação de Medicamentos , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Cloreto de Potássio/química , Cloreto de Potássio/farmacologia , Pirrolidinonas/química , Reprodutibilidade dos Testes , Irrigantes do Canal Radicular/química , Bicarbonato de Sódio/química , Bicarbonato de Sódio/farmacologia , Cloreto de Sódio/química , Cloreto de Sódio/farmacologia , Estatísticas não Paramétricas
5.
Meat Sci ; 165: 108130, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32224414

RESUMO

The objectives of this study were to evaluate the effects of power ultrasound (nominal intensity 600 W·cm-2 for 10 min) and the addition of potassium chloride (KCl) on the physicochemical properties and sensorial acceptance of low sodium restructured cooked ham. Four treatments of low sodium restructured cooked ham (mean of 324.52 mg Na/100 g) were prepared: CT - Control Treatment; UsT - Ultrasound Treatment; KT - addition of 0.5% KCl; UsKT - Ultrasound Treatment and addition of 0.5% KCl. Ultrasound application reduced the total fluid released and improved the sensory acceptance for salty taste and flavor compared to CT. The addition of KCl showed the lowest values for total fluid release, the highest scores for all parameters of sensory acceptance, improved hardness and chewiness, which results were not statistically different from the results obtained by combining ultrasound and KCl. Therefore, the use of KCl was considered a technological and sensorial viable alternative to produce low sodium restructured cooked ham. CHEMICAL COMPOUNDS USED IN THIS RESEARCH: Methanol (PubChem CID: 887); Chloroform (PubChem CID: 6212); Sodium Carbonate (PubChem CID: 10340); Sodium hydroxide (PubChem CID: 14798); Boric acid (PubChem CID: 7628).


Assuntos
Produtos da Carne/análise , Cloreto de Potássio/química , Ondas Ultrassônicas , Animais , Cor , Comportamento do Consumidor , Humanos , Produtos da Carne/microbiologia , Cloreto de Sódio na Dieta , Suínos , Paladar
6.
Meat Sci ; 159: 107939, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31513991

RESUMO

Low-fat bologna sausages were made with the replacement of 60% NaCl by KCl and with the addition of arginine and histidine alone or in combination. The technological and sensory properties were evaluated. The replacement of NaCl by KCl did not significantly affect the color parameters L*, a*, and b*. However, the emulsion stability, the texture profile, and the sensory quality were impaired by the salt substitution. The addition of arginine and histidine alone or in combination was effective to reduce the defects caused by the addition of KCl. The present study demonstrated that bologna sausages with reduced sodium content (≈40%) and acceptable technological and sensory properties can be produced using 1% NaCl, 1.5% KCl, 1% arginine and 0.2% histidine.


Assuntos
Arginina/química , Histidina/química , Produtos da Carne/normas , Carne de Porco/normas , Cloreto de Potássio/química , Adolescente , Adulto , Idoso , Animais , Comportamento do Consumidor , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Produtos da Carne/análise , Pessoa de Meia-Idade , Carne de Porco/análise , Sensação , Adulto Jovem
7.
Food Chem ; 309: 125614, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31678672

RESUMO

Effects of partial substitution of NaCl with KCl, MgCl2 or CaCl2 on oxidative characteristics of myofibrillar protein (MP) in a hydroxyl radical generating system and their heat-induced gel properties were investigated. Results indicated that MP oxidation is dependent upon the different chloride salt types and substitution degree. MP at 0.60 M NaCl was beneficial to protein unfolding and gel quality in the oxidative system. Increased formation of disulfide bonds affected the MP conformation and resulted in a large particle size and an aggregatednetworkofgel at the 50% substitution degree of KCl. The presence of CaCl2 or MgCl2 substitutes contributed to protein polymerization and insolubility. MP aggregation restrained the formation of dense and continuous gel networks during heating, and thus resulted in a low-grade gel. Ca2+ had more serious impact on gel properties than Mg2+, dependent on different cation effects. Substitution of 25% NaCl by KCl gave acceptable gel quality in MP.


Assuntos
Manipulação de Alimentos/métodos , Proteínas Musculares/química , Cloreto de Potássio/química , Cloreto de Sódio/química , Animais , Cloreto de Cálcio/química , Dissulfetos/química , Géis/química , Radical Hidroxila/química , Cloreto de Magnésio/química , Oxirredução , Tamanho da Partícula , Carne de Porco , Desdobramento de Proteína
8.
J. appl. oral sci ; 28: e20190516, 2020. graf
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1090775

RESUMO

Abstract This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). Methodology Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). Results CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. Conclusions CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.


Assuntos
Animais , Bovinos , Pirrolidinonas/farmacologia , Irrigantes do Canal Radicular/farmacologia , Hidróxido de Cálcio/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Antibacterianos/farmacologia , Cloreto de Potássio/farmacologia , Cloreto de Potássio/química , Pirrolidinonas/química , Irrigantes do Canal Radicular/química , Teste de Materiais , Cloreto de Cálcio/farmacologia , Cloreto de Cálcio/química , Hidróxido de Cálcio/química , Microscopia Eletrônica de Varredura , Cloreto de Sódio/farmacologia , Cloreto de Sódio/química , Contagem de Colônia Microbiana , Reprodutibilidade dos Testes , Análise de Variância , Bicarbonato de Sódio/farmacologia , Bicarbonato de Sódio/química , Estatísticas não Paramétricas , Microscopia Confocal , Combinação de Medicamentos
9.
Nucleic Acids Res ; 47(16): 8860-8873, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31310308

RESUMO

Interactions between proteins and DNA are crucial for all biological systems. Many studies have shown the dependence of protein-DNA interactions on the surrounding salt concentration. How these interactions are maintained in the hypersaline environments that halophiles inhabit remains puzzling. Towards solving this enigma, we identified the DNA motif recognized by the Halobactrium salinarum ROS-dependent transcription factor (hsRosR), determined the structure of several hsRosR-DNA complexes and investigated the DNA-binding process under extreme high-salt conditions. The picture that emerges from this work contributes to our understanding of the principles underlying the interplay between electrostatic interactions and salt-mediated protein-DNA interactions in an ionic environment characterized by molar salt concentrations.


Assuntos
Proteínas Arqueais/química , DNA Arqueal/química , Halobacterium salinarum/genética , Cloreto de Potássio/química , Tolerância ao Sal/genética , Fatores de Transcrição/química , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , DNA Arqueal/genética , DNA Arqueal/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Halobacterium salinarum/metabolismo , Haloferax/genética , Haloferax/metabolismo , Cinética , Modelos Moleculares , Conformação de Ácido Nucleico , Cloreto de Potássio/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Estresse Fisiológico , Termodinâmica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Nano Lett ; 19(8): 5661-5666, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31313927

RESUMO

The translocation of double-stranded DNA through a solid-state nanopore may either decrease or increase the ionic current depending on the ionic concentration of the surrounding solution. Below a certain crossover ionic concentration, the current change inverts from a current blockade to current enhancement. In this paper, we show that the crossover concentration for bundled DNA nanostructures composed of multiple connected DNA double-helices is lower than that of double-stranded DNA. Our measurements suggest that counterion mobility in the vicinity of DNA is reduced depending on the three-dimensional structure of the molecule. We further demonstrate that introducing neutral polymers such as polyethylene glycol into the measurement solution reduces electroosmotic outflow from the nanopore, allowing translocation of large DNA structures at low salt concentrations. Our experiments contribute to an improved understanding of ion transport in confined DNA environments, which is critical for the development of nanopore sensing techniques as well as synthetic membrane channels. Our salt-dependent measurements of model DNA nanostructures will guide the development of computational models of DNA translocation through nanopores.


Assuntos
DNA/química , Nanoporos , Eletro-Osmose , Transporte de Íons , Íons/química , Nanoporos/ultraestrutura , Nanotecnologia , Conformação de Ácido Nucleico , Polietilenoglicóis/química , Cloreto de Potássio/química
12.
Environ Sci Pollut Res Int ; 26(23): 23279-23291, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31197670

RESUMO

The use of alunite as an adsorbent for the removal of dye was the aim of this report. Mixing the alunite with different salts may allow adsorption with higher efficiency. In the present study, the thermal decomposition product of alunite-potassium chloride mixture (TDPA-KCl) was used efficiently and inexpensively to remove Reactive Blue 49 (RB49) dye. The adsorption capacity of TDPA-KCl was found to be affected by pH, temperature, adsorbent amount, calcination temperature, dye concentration, and ionic strength. The highest RB49 adsorption yield was obtained at an initial pH of 2 and an equilibrium was reached within 20 min using 80 mg of adsorbent. The most suitable kinetic model was found as the pseudo-second-order and compatible isotherm was determined as the Langmuir model. The optimum adsorption capacity was found as 119.10 mg g-1 at 40 °C. ∆G°, ∆H°, and ∆S° values were calculated. A positive value of ∆H° stated that the adsorption is exothermic and spontaneous. In addition, ∆G° showed a more negative value when temperature was increased. Column studies indicated that TDPA-KCl could be effectively used for five cycles without any loss in its desorption potential. Breakthrough studies also supported a favorable adsorption of RB49 onto TDPA-KCl. This study showed that TDPA-KCl is a practical, efficient, and inexpensive adsorbent to remove reactive dyes from wastewater.


Assuntos
Compostos de Alumínio/química , Corantes/análise , Cloreto de Potássio/química , Compostos de Potássio/química , Sulfatos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Temperatura , Têxteis , Águas Residuárias/química
13.
Meat Sci ; 156: 205-213, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31202095

RESUMO

The effect of partial replacement of NaCl by using sodium substitutes (SS) on the physical, microbial and sensory characteristics of Harbin dry sausage was investigated. There were three salt formulations, including control (100% NaCl), NaCl partly substituted by KCl (SS1) (70% NaCl and 30% KCl), and NaCl partly substituted by KCl combined with other components (SS2) (70% NaCl, 20% KCl, 3.5% maltodextrin, 4% L-Lys, 1% L-Ala, 0.5% citric acid and 1% Ca-lactate). After a 12-day fermentation, the higher moisture content and Aw and lower pH were found in the SS2 treatment, compared to the control and SS1 treatments (P < .05). A decreased microbial diversity during fermentation was found in all sausages, and Staphylococcus spp. and Lactobacillus spp. became the dominant genera. Additionally, the SS2 treatment showed a higher L*-value and lower hardness and chewiness values (P < .05). Therefore, the formulation of SS2 could achieve a NaCl reduction of 30% in Harbin dry sausages with a better sensory acceptability.


Assuntos
Produtos da Carne/análise , Cloreto de Sódio na Dieta/análise , Animais , Cor , Feminino , Fermentação , Manipulação de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus , Masculino , Produtos da Carne/microbiologia , Cloreto de Potássio/química , Staphylococcus , Suínos , Paladar
14.
Anaesthesia ; 74(11): 1374-1380, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31066048

RESUMO

The use of uncoated aluminium-heated plates in an intravenous fluid-warming system has been shown to produce high levels of aluminium in Sterofundin 1/1E, a balanced crystalloid solution. However, the effect of this fluid-warming device on other balanced crystalloid solutions and blood products has not been studied. Using mass spectrometry we measured aluminium levels in Plasma-Lyte 148, compound sodium lactate solution, 4% human albumin solution, expired resuspended packed red cells and fresh frozen plasma that were pumped through an enFlow® fluid-warming system at 2 ml.min-1 . Samples were taken at baseline before heating and then at 10-min intervals up to 60 min with the system set to warm the fluids to 40 °C. High concentrations of aluminium were found for Plasma-Lyte 148 and compound sodium lactate solutions (mean (SD) 223 (0.6) µmol.l-1 and 163 (0.2) µmol.l-1 at 60 min, respectively); both concentrations were significantly greater than the United States Food and Drug Administration recommended maximum limit for aluminium in intravenous nutrition of 25 µg.l-1 (0.9 µmol.l-1 ). Lower aluminium levels were found in 4% human albumin solutions, expired resuspended red cells and fresh frozen plasma at 60 min (mean (SD) 5.7 (0.1) µmol.l-1 , 2.7 (0.0) µmol.l-1 and 2.3 (0.4) µmol.l-1 , respectively). The process allowing addition of aluminium to be added to Sterofundin 1/1E by the enFlow fluid warmer also occurs in Plasma-Lyte 148 and compound sodium lactate solutions and to a lesser degree in blood products. The exact mechanism facilitating this process and its clinical significance remain unclear.


Assuntos
Alumínio/metabolismo , Análise Química do Sangue/métodos , Soluções Cristaloides/química , Calefação/instrumentação , Desenho de Equipamento , Eritrócitos/química , Gluconatos/química , Humanos , Soluções Isotônicas/química , Cloreto de Magnésio/química , Espectrometria de Massas/métodos , Plasma/química , Cloreto de Potássio/química , Albumina Sérica Humana/química , Acetato de Sódio/química , Cloreto de Sódio/química , Lactato de Sódio/química , Fatores de Tempo
15.
Meat Sci ; 156: 33-43, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31125945

RESUMO

The effects of partially replacing NaCl with sodium substitutes (SS) on the lipid and protein oxidation and flavor development of Harbin dry sausage was investigated. There were three salt formulations, including a control (100% NaCl), NaCl partially substituted with KCl (SS1) (70% NaCl and 30% KCl), and NaCl partially substituted with KCl combined with other components (SS2) (70% NaCl, 20% KCl, 4% lysine, 1% alanine, 0.5% citric acid, 1% Ca-lactate and 3.5% maltodextrin). The levels of lipid and protein oxidation increased in all sausages during fermentation (P < 0.05). In addition, lower oxidation of lipids and proteins were found in the SS2 treatment (P < 0.05) due to the lower NaCl concentration. The SS, especially the SS2, promoted the formation of volatile compounds originated from carbohydrate and amino acid metabolism, ß-lipid oxidation and esterification; however, this substitute inhibited the formation of volatile compounds originated from lipid autooxidation (P < 0.05). Overall, SS2 could improve the flavor development of Harbin dry sausage and reduce NaCl by 30%.


Assuntos
Manipulação de Alimentos/métodos , Produtos da Carne/análise , Cloreto de Sódio na Dieta , Animais , Fermentação , Aromatizantes/química , Lipídeos/química , Oxirredução , Cloreto de Potássio/química , Proteínas/química , Suínos , Paladar
16.
Pharm Res ; 36(7): 98, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31087169

RESUMO

PURPOSE: To study the effect of mannitol or trehalose on the crystallization behavior of solutes in phosphate buffered saline (PBS) when the solutions were frozen and freeze-dried. METHODS: PBS (pH 7.5 at RT) either alone, or with trehalose (5% w/v) or mannitol (1% w/v), were frozen and characterized using low temperature differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and pH measurement. Freeze dried lyophiles were characterized by XRD. RESULTS: In the absence of cosolutes, upon freezing PBS, a pH shift of ~ 4 units was observed due to crystallization of Na2HPO4•12H2O. XRD indicated sequential crystallization of Na2HPO4•12H2O, NaCl•2H2O and KCl during cooling. When the frozen solutions were heated, two eutectics were observed - the first at ~ -24°C (ternary, NaCl•2H2O-KCl-ice) and the second at ~ -22°C (binary, NaCl•2H2O-ice). Trehalose completely inhibited buffer salt crystallization, whereas mannitol suppressed it partially thereby attenuating the magnitude of pH shift. The two eutectic meltings were also suppressed by the cosolutes. XRD of final lyophiles from PBS alone revealed peaks of anhydrous Na2HPO4, NaCl, and KCl. Trehalose rendered the lyophiles completely XRD amorphous, whereas in presence of mannitol, all the solutes except KH2PO4 crystallized. CONCLUSIONS: Freezing of PBS solution caused a pronounced pH shift due to selective crystallization of Na2HPO4•12H2O. The addition of trehalose or mannitol suppressed the buffer salt crystallization and attenuated the magnitude of pH shift. The potential instability of biologics due to pH shift in PBS, can be potentially mitigated with the cosolutes.


Assuntos
Manitol/química , Fosfatos/química , Solução Salina/química , Trealose/química , Tampões (Química) , Cristalização , Liofilização , Congelamento , Concentração de Íons de Hidrogênio , Cloreto de Potássio/química , Cloreto de Sódio/química , Temperatura
17.
Environ Geochem Health ; 41(5): 2081-2091, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30838487

RESUMO

This study evaluated the feasibility of combining potassium chloride (KCl) leaching and electrokinetic (EK) treatment for the remediation of cadmium (Cd) and other metals from contaminated soils. KCl leaching was compared at three concentrations (0.2%, 0.5%, and 1% KCl). EK treatment was conducted separately to migrate the metals in the topsoil to the subsoil. The combined approach using KCl leaching before or after EK treatment was compared. For the single vertical EK treatment, the removal of Cd, lead (Pb), copper (Cu) and zinc (Zn) from the topsoil (0-20 cm) was 9.38%, 4.80%, 0.95%, and 10.81%, respectively. KCl leaching at 1% KCl removed 84.06% Cd, 9.95% Pb, 4.34% Cu, and 19.93% Zn from the topsoil, with higher removal efficiency than that of the 0.2% and 0.5% KCl leaching treatments. By combining the KCl leaching and EK treatment, the removal efficiency of heavy metals improved, in particular for the 1% KCl + EK treatment, where the removal rate of Cd, Pb, Cu, and Zn from the upper surface soil reached 97.79%, 17.69%, 14.37%, and 41.96%, respectively. Correspondingly, the soil Cd content decreased from 4 to 0.21 mg/kg, and was below the Chinese standard limit of 0.3 mg/kg soil. These results indicate that 1% KCl + EK treatment is a good combination technique to mitigate Cd pollution from contaminated soils used for growing rice and leafy vegetables.


Assuntos
Cádmio/isolamento & purificação , Recuperação e Remediação Ambiental/métodos , Cloreto de Potássio/química , Poluentes do Solo/isolamento & purificação , Cádmio/análise , Cádmio/química , Técnicas Eletroquímicas , Poluição Ambiental/prevenção & controle , Metais Pesados/análise , Metais Pesados/química , Metais Pesados/isolamento & purificação , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/química
18.
PLoS One ; 14(3): e0213598, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30901332

RESUMO

Phosphorylation of the C-terminal domain (CTD) of the large subunit of human RNA polymerase II (Pol II) is regulated during the transcription cycle by the combined action of specific kinases and phosphatases. Pol II enters into the preinitiation complex (PIC) unphosphorylated, but is quickly phosphorylated by Cdk7 during initiation. How phosphatases alter the pattern and extent of CTD phosphorylation at this early stage of transcription is not clear. We previously demonstrated the functional association of an early-acting, magnesium-independent phosphatase with early elongation complexes. Here we show that Ssu72 is responsible for that activity. We found that the phosphatase enters the transcription cycle during the formation of PICs and that Ssu72 is physically associated with very early elongation complexes. The association of Ssu72 with elongation complexes was stable to extensive washing with up to 200 mM KCl. Interestingly, Ssu72 ceased to function on complexes that contained RNA longer than 28 nt. However, when PICs were washed before initiation, the strict cutoff at 28 nt was lost. This suggests that factor(s) are important for the specific regulation of Ssu72 function during the transition between initiation and pausing. Overall, our results demonstrate when Ssu72 can act on early transcription complexes and suggest that Ssu72 may also function in the PIC prior to initiation.


Assuntos
Proteínas de Transporte/química , RNA Polimerase II/química , Elongação da Transcrição Genética , Iniciação da Transcrição Genética , Proteínas de Transporte/metabolismo , Quinases Ciclina-Dependentes/química , Quinases Ciclina-Dependentes/metabolismo , Humanos , Fosforilação , Cloreto de Potássio/química , Domínios Proteicos , RNA Polimerase II/metabolismo
19.
Molecules ; 24(4)2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30781833

RESUMO

Enzymatic activity assays are essential and critical for the study of enzyme kinetics. Adenylate kinase (Adk) plays a fundamental role in cellular energy and nucleotide homeostasis. To date, assays based on different principles have been used for the determination of Adk activity. Here, we show a spectrophotometric analysis technique to determine Adk activity with bromothymol blue as a pH indicator. We analyzed the effects of substrates and the pH indicator on the assay using orthogonal design and then established the most optimal assay for Adk activity. Subsequently, we evaluated the thermostability of Adk and the inhibitory effect of KCl on Adk activity with this assay. Our results show that this assay is simple, rapid, and precise. It shows great potential as an alternative to the conventional Adk activity assay. Our results also suggest that orthogonal design is an effective approach, which is very suitable for the optimization of complex enzyme reaction conditions.


Assuntos
Adenilato Quinase/química , Espectrofotometria/métodos , Azul de Bromotimol/química , Homeostase , Concentração de Íons de Hidrogênio , Cinética , Fosforilação , Cloreto de Potássio/química
20.
Food Res Int ; 116: 346-353, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30716955

RESUMO

Chloride salts can serve as sodium chloride (NaCl) substitutes in wheat dough for sensory or technological reasons. Therefore, the effect of different substitutes on wheat dough development during mixing (optimum water absorption, dough development time, stability) and fermentation (maximum dough height) with a material-adapted water addition and mixing time were investigated. The substitutes had effects on all measures at a level of 2 g salt 100 g-1 wheat flour, with the exception of KCl. The intensity of the effect significantly followed the Hofmeister series due to an altered hydration behavior of the structure-determining gluten proteins. The experiments were supported by CLSM micrographs combined with image analysis. Next to an absolute substitution, the main focus of the study were concentration dependent functionalities of the chloride salts. Therefore, concentration dependent rate constants were calculated based on the application of different concentration levels of the chloride salts. These rate constants showed in all cases a similar tendency following the Hofmeister series.


Assuntos
Farinha/análise , Cloreto de Sódio/química , Sódio/química , Triticum/química , Pão/análise , Fermentação , Manipulação de Alimentos , Glutens , Concentração de Íons de Hidrogênio , Cloreto de Potássio/química , Reologia , Água/química
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