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1.
Plant Physiol Biochem ; 212: 108768, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797008

RESUMO

Potassium (K+) selectivity of high-affinity K+ uptake systems is crucial for plant growth under low K+ and in the presence of inhibitors of K+ uptake that are toxic to plants such as Na+ or Cs+. Here, we express a mutated version of the Arabidopsis AtHAK5 high-affinity K+ transporter consisting on a change of phenylalanine 130 to serine (F130S) in athak5 akt1 double mutant plants. F130S-expressing plants show better growth, increased K+ uptake from low external concentrations and higher K+ contents when grown at low K+ (10 µM) and when grown at low K+ in the presence of Na+ (15 mM) or Cs+ (1 µM). In addition, these plants accumulate less Na+ and Cs+, resulting in lower Na+/K+ and Cs+/K+ ratios, which are important determinants of plant tolerance to salt stress and to Cs+-polluted soils. Structure analysis of AtHAK5 suggest that the F130 residue approaches the intracellular gate of the K+ tunnel of AtHAK5, affecting somehow its ionic selectivity. Modification of transport systems has a large potential to face challenges of future agriculture such as sustainable production under abiotic stress conditions imposed by climate change.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Potássio , Arabidopsis/genética , Arabidopsis/metabolismo , Potássio/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sódio/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Mutação , Estresse Fisiológico/genética , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Antiportadores de Potássio-Hidrogênio
2.
Waste Manag ; 96: 181-189, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376963

RESUMO

In this work, an environmentally-friendly leaching process for the recovery of indium (In) and tin (Sn) from LCD panel waste was investigated. Easily degradable citrates (C6H5O73-), i.e., sodium citrate and citric acid, were used as complexing agents. The morphology and composition of the species present in the LCD powder before and after the leaching processes were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The concentrations of In, Sn, and iron (Fe) present in the leachate were determined by atomic absorption spectrometry (AAS). The necessary thermodynamic conditions for achieving substantial In recovery were established by using MEDUSA software. The optimal process conditions were determined experimentally by varying the initial citrate concentration as well as by using reducing or oxidizing media, respectively hydrazine (N2H4) or hydrogen peroxide (H2O2). It was found that using N2H4 in a citrate solution as a reducing agent enhances the leaching efficiency. However, high concentrations of Sn and Fe with respect to In were found in the LCD powder. Therefore, a pretreatment processes to first remove the excess of Sn and Fe, which compete with In for the citrate, was implemented. Leaching with 1 M citrate, 0.2 M N2H4, at pH = 5, using sodium hydroxide (NaOH) at solid:liquid (S:L) ratio of 20 g∙L-1, yielded a remarkably high In recovery of 98.9% after 16.6 h.


Assuntos
Resíduo Eletrônico , Cristais Líquidos , Citratos , Ácido Cítrico , Peróxido de Hidrogênio , Índio , Reciclagem , Estanho
3.
Neurogastroenterol Motil ; 31(9): e13651, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31145538

RESUMO

BACKGROUND: Food and diet are central issues for proper functioning of the cardiovascular (CV) system and gastrointestinal (GI) tract. We hypothesize that different types of dietary FAs affect CV parameters as well as GI motor function and visceral sensitivity. METHODS: Male Wistar rats were fed with control diet (CTRL), diet supplemented with 7% soybean oil (SOY), SOY + 3.5% virgin coconut oil (COCO), and SOY + 3.5% evening primrose oil (EP) for 4 weeks. The content of insoluble fiber in CTRL was higher than in SOY, COCO, or EP. Body weight gain and food/water intake were measured. At day 28, biometric, biochemical, CV parameters, GI motor function (X-ray and colon bead expulsion test), and visceral sensitivity were evaluated. Changes in propulsive colonic activity were determined in vitro. The colon and adipose tissue were histologically studied; the number of mast cells (MCs) in the colon was calculated. RESULTS: SOY, COCO, and EP had increased body weight gain but decreased food intake vs CTRL. Water consumption, biometric, biochemical, and CV parameters were comparable between groups. SOY increased the sensitivity to colonic distention. All groups maintained regular propulsive neurogenic contractions; EP delayed colonic motility (P < 0.01). SOY, COCO, and EP displayed decreased size of the cecum, lower number and size of fecal pellets, and higher infiltration of MCs to the colon (P < 0.001). CONCLUSIONS AND INFERENCES: Dietary FAs supplementation and lower intake of insoluble fiber can induce changes in the motility of the lower GI tract, in vivo and in vitro, but CV function and visceral sensitivity are not generally affected.


Assuntos
Pressão Sanguínea/fisiologia , Fibras na Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Motilidade Gastrointestinal/fisiologia , Frequência Cardíaca/fisiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Óleo de Coco/administração & dosagem , Motilidade Gastrointestinal/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Óleo de Soja/administração & dosagem
4.
Rev. latinoam. cienc. soc. niñez juv ; 10(2): 943-955, sept. 2012. tab
Artigo em Espanhol | LILACS | ID: lil-658669

RESUMO

En este trabajo analizamos la relación entre Anomia Psicológica y Social, Alienación, Confianza en las Instituciones y Conducta Antisocial, en una muestra de jóvenes mexicanos infractores de ley. Aplicamos una batería de cinco instrumentos y preguntas sociodemográficos a 126 adolescentes varones infractores recluidos en el Instituto de Tratamiento y de Aplicación de Medidas para Adolescentes en Sonora. Los resultados muestran que la Alienación y la Anomia Social resultaron significativas, y en interacción explican el 0,23% de la varianza de la Conducta Antisocial y Delictiva en los menores infractores. Además, en un análisis discriminante, ambas variables distinguen a los grupos en delincuentes e infractores. Este estudio nos indica que los programas de intervención deberán considerar mecanismos que impacten en el microambiente del infractor, si se pretende su reintegración a la sociedad.


Assuntos
Anomia (Social) , Comportamento , México , Alienação Social
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