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1.
J Environ Sci (China) ; 110: 38-47, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593193

RESUMEN

To assess groundwater nitrate contamination and its human health risks, 489 unconfined groundwater samples were collected and analyzed from Zhangjiakou, northern China. The spatial distribution of principle hydrogeochemical results showed that the average concentrations of ions in descend order was HCO3-, SO42-, Na+, Ca2+, Cl-, NO3-, Mg2+ and K+, among which the NO3- concentrations were between 0.25 and 536.73 mg/L with an average of 29.72 mg/L. In total, 167 out of 489 samples (~ 34%) exceeded the recommended concentration of 20 mg/L in Quality Standard for Groundwater of China. The high NO3- concentration groundwater mainly located in the northern part and near the boundary of the two geomorphic units. As revealed by statistical analysis, the groundwater chemistry was more significantly affected by anthropogenic sources than by the geogenic sources. Moreover, human health risks of groundwater nitrate through oral and dermal exposure pathways were assessed by model, the results showed that about 60%, 50%, 32% and 26% of the area exceeded the acceptable level (total health index>1) for infants, children, adult males and females, respectively. The health risks for different groups of people varied significantly, ranked: infants> children> adult males>adult females, suggesting that younger people are more susceptible to nitrate contamination, while females are more resistant to nitrate contamination than males. To ensure the drinking water safety in Zhangjiakou and its downstream areas, proper management and treatment of groundwater will be necessary to avoid the health risks associated with nitrate contamination.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Nitratos/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
2.
Toxins (Basel) ; 13(9)2021 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-34564633

RESUMEN

Impacts of ocean acidification (OA) on noncalcifying organisms and the possibly responsible mechanism have aroused great research interests with the intensification of global warming. The present study focused on a noxious, noncalcifying, bloom-forming dinoflagellate, Karenia mikimotoi (K. mikimotoi), and its variation of growth patterns exposed to different periods of seawater acidification with stressing gradients was discussed. The dinoflagellates under short-time acidifying stress (2d) with different levels of CO2 presented significant growth inhibition (p < 0.05). The cell cycle was obviously inhibited at S phase, and the photosynthetic carbon fixation was also greatly suppressed (p < 0.05). Apoptosis was observed and the apoptotic rate increased with the increment of pCO2. Similar tendencies were observed in the key components of mitochondrial apoptotic pathway (the mitochondrial membrane potential (MMP), Caspase-3 and -9, and Bax/Bcl-2 ratio). However, under prolonged stressing time (8 d and 15 d), the growth of dinoflagellates was recovered or even stimulated, the photosynthetic carbon fixation was significantly increased (p < 0.05), the cell cycle of division presented little difference with those in the control, and no apoptosis was observed (p > 0.05). Besides, acidification adjusted by HCl addition and CO2 enrichment resulted in different growth performances, while the latter had a more negative impact. The results of present study indicated that (1) the short-time exposure to acidified seawater led to reduced growth performance via inducing apoptosis, blocking of cell cycle, and the alteration in photosynthetic carbon fixation. (2) K. mikimotoi had undergone adaptive changes under long-term exposure to CO2 induced seawater acidification. This further demonstrated that K. mikimotoi has strong adaptability in the face of seawater acidification, and this may be one of the reasons for the frequent outbreak of red tide. (3) Ions that dissociated by the dissolved CO2, instead of H+ itself, were more important for the impacts induced by the acidification. This work thus provides a new perspective and a possible explanation for the dominance of K. mikimotoi during the occurrence of HABs.

3.
Biochem Biophys Res Commun ; 567: 190-194, 2021 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-34166917

RESUMEN

Pif1 helicases, conserved in eukaryotes, are involved in maintaining genome stability in both the nucleus and mitochondria. Here, we report the crystal structure of a truncated Candida Albicans Pif1 (CaPif1368-883) in complex with ssDNA and an ATP analog. Our results show that the Q-motif is responsible for identifying adenine bases, and CaPif1 preferentially utilizes ATP/dATP during dsDNA unwinding. Although CaPif1 shares structural similarities with Saccharomyces cerevisiae Pif1, CaPif1 can contact the thymidine bases of DNA by hydrogen bonds, whereas ScPif1 cannot. More importantly, the crosslinking and mutant experiments have demonstrated that the conformational change of domain 2B is necessary for CaPif1 to unwind dsDNA. These findings contribute to further the understanding of the unwinding mechanism of Pif1.


Asunto(s)
Candida albicans/metabolismo , ADN Helicasas/metabolismo , Proteínas Fúngicas/metabolismo , Adenosina Trifosfato/metabolismo , Candida albicans/química , Candidiasis/microbiología , Cristalografía por Rayos X , ADN/metabolismo , ADN Helicasas/química , ADN de Cadena Simple/metabolismo , Proteínas Fúngicas/química , Humanos , Modelos Moleculares , Conformación Proteica
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(6): 588-592, 2021 Jun.
Artículo en Chino | MEDLINE | ID: mdl-34130780

RESUMEN

OBJECTIVE: To investigate the factors contributing to the withdrawal from treatment in neonates with respiratory failure. METHODS: The medical data of 2 525 neonates with respiratory failure were retrospectively studied, who were reported in 30 hospitals of Jiangsu Province from January to December, 2019. According to whether a complete treatment was given, they were divided into a complete treatment group with 2 162 neonates and a withdrawal group with 363 neonates. A multivariate logistic regression analysis was used to investigate the factors contributing to the withdrawal from treatment in neonates with respiratory failure. RESULTS: The multivariate logistic regression analysis showed that small-for-gestational-age birth, congenital abnormality, gestational age < 28 weeks, living in the rural area or county-level city, and maternal age < 25 years were risk factors for the withdrawal from treatment in neonates with respiratory failure (P < 0.05), while a higher 5-minute Apgar score and cesarean section were protective factors (P < 0.05). Furthermore, 176 answers were obtained from 160 parents of the neonates who were willing to tell the reason for the withdrawal from treatment, among which severe sequelae (44.9%, 79/176) had the highest frequency, followed by uncontrollable disease condition (24.4%, 43/176), family financial difficulties (18.2%, 32/176), and dependence on mechanical ventilation (12.5%, 22/176). CONCLUSIONS: Small-for-gestational-age birth, congenital abnormality, gestational age, living area, maternal age, Apgar score at birth, and method of birth are contributing factors for the withdrawal from treatment in neonates with respiratory failure. A poor prognosis and a low quality of life in future might be major immediate causes of withdrawal from treatment in neonates with respiratory failure, which needs to be confirmed by further studies.


Asunto(s)
Cesárea , Insuficiencia Respiratoria , Puntaje de Apgar , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Embarazo , Calidad de Vida , Insuficiencia Respiratoria/terapia , Estudios Retrospectivos , Factores de Riesgo
5.
Environ Pollut ; 287: 117341, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34023659

RESUMEN

Our previous study showed that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), the most biotoxic polybrominated diphenyl ether (PBDE) in the marine environment, induced apoptosis in rainbow trout gonadal RTG-2 cells. This effect occurred via ROS- and Ca2+-mediated apoptotic pathways, but the exact mechanism remains unknown. Therefore, in the present study, the possible mechanism was examined from the perspective of ROS-induced oxidative stress. The results showed that BDE-47 exposure significantly elevated the malondialdehyde (MDA) contents and the intracellular GSH/GSSG ratio, and the GSH-related enzymes were greatly altered, indicating alteration of the redox status and occurrence of oxidative stress. The mRNA levels of nuclear factor E2-related factor 2 (Nrf2) and its downstream genes were simultaneously greatly elevated. The p38 mitogen-activated protein kinase (MAPK) signaling pathway was also found to be induced by BDE-47 exposure. The addition of SB203580, a p38 MAPK inhibitor resulted in decreased apoptosis. In addition, supplementation with Ca2+ inhibitors BAPTA-AM positively affected p38 MAPK activation. Taken together, BDE-47 exposure resulted in the occurrence of oxidative stress and initiated the Nrf2-mediated antioxidant response. Subsequently, the altered redox status induced p38 MAPK activation, which played a pivotal role in the cellular apoptosis of RTG-2 cells.


Asunto(s)
Éteres Difenilos Halogenados , Oncorhynchus mykiss , Animales , Antioxidantes , Apoptosis , Éteres Difenilos Halogenados/toxicidad , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Oncorhynchus mykiss/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
6.
Adv Ther ; 38(1): 607-626, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33180318

RESUMEN

INTRODUCTION: Apnoea of prematurity (AOP) is among the most common diagnoses in the neonatal intensive care unit. Caffeine treatment is a preferred treatment choice. However, neonatal caffeine therapy results in significant intersubject variability. This study aimed to determine the effects of plasma caffeine levels based on standard dose and genetic variability on clinical response to caffeine citrate in Chinese preterm infants. METHODS: This single-center and retrospective study examined data from 112 preterm infants (< 35 weeks gestational age) between July 2017 and July 2018. Subjects were divided into apnoea-free (n = 48) and apnoeic (n = 64) groups, and their clinical outcomes were summarized. Liquid chromatography-tandem mass spectrometry was used to measure levels of caffeine and its primary metabolites. Eighty-eight single-nucleotide polymorphisms were chosen for genotyping by a MassARRAY system. RESULTS: Preterm infants in the apnoea-free group were associated with a reduction in the incidence of bronchopulmonary dysplasia and a reduced requirement for patent ductus arteriosus ligation. No significant association was observed between plasma-trough-concentration-to-dose (C0/D) ratio and birth weight, gestational age, or postnatal age in either group. Polymorphisms in CYP1A2 and aryl hydrocarbon receptor (AHR) genes did not affect plasma caffeine levels. Polymorphisms in adenosine receptor genes ADORA1 (rs10920568 and rs12744240), ADORA2A (rs34923252 and rs5996696), and ADORA3 (rs10776727 and rs2298191), especially in AHR (rs4410790) and adenosine deaminase (rs521704), play critical roles in the interindividual response to caffeine therapy. CONCLUSIONS: Genetic polymorphisms in caffeine's target receptors, but not the exposure levels based on the standard dosing, were associated with variable responses to caffeine therapy in preterm neonates. Future studies are needed to uncover how these genetic variants affect responses to caffeine therapy in this patient population.


Asunto(s)
Apnea , Cafeína , Apnea/tratamiento farmacológico , Apnea/genética , Cafeína/uso terapéutico , China , Citratos , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Estándares de Referencia , Estudios Retrospectivos
7.
Chemosphere ; 269: 128736, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33131734

RESUMEN

Depiction on an energetic chain in terms of assimilation, allocation and consumption as well as the linkage between energetic alteration and physiological process was performed in blue mussel Mytilus edulis coping with tetrabromodiphenyl ether (BDE-47) based on a 21-day bioassay to shed light on the possible mechanism from energetic perspective. The filtration was hindered along with BDE-47 concentration increment and the influence of digestion was suggested according to the combination of the digestive enzymatic activities' alteration and digestive gland tissue impairment, both of which decided the energy availability reduction. Energy consumption indicated by the electron transport system activity was firstly inhibited while was greatly increased with BDE-47 increment, and the cellular energy allocation and adenylate pool were decreased simultaneously. An energetic chain was thus depicted: it tended to reduce energy absorption, elevate the energy consumption and decrease the energy metabolism with BDE-47 exposure, and M. edulis adopted the energetic strategy with variation regarding to the stressing level, suggesting as the preference switched from protein utilization to lipid utilization with the concentration increment. A consistence was observed in index of growth and survival with the change of energy allocation, inferring the energetic involvement in sustaining the viability of the mussel.


Asunto(s)
Mytilus edulis , Mytilus , Adaptación Psicológica , Animales , Éteres Difenilos Halogenados/toxicidad , Alimentos Marinos
8.
Biosens Bioelectron ; 171: 112690, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33049561

RESUMEN

Development of reliable Enzymatic Biofuel Cells (EBFC)-based self-powered glucose biosensor for continuous, noninvasive monitoring without restriction on patient's movement is highly recommendable. However, its application to a large extent is limited by the relatively poor stability. Herein, we synthesized a highly flexible electrode for effective enzyme immobilization by encapsulating enzyme into the metal-organic frameworks (MOFs) and robustly anchored to the cellulose acetate (CA) nanofiber membrane. As is well-known, such nanostructured fiber materials are the first time to be synthesized for glucose biosensor, which encapsulated biomolecules in MOFs platform during the MOFs in-situ growth on the nanofiber membranes. The as-proposed biosensor demonstrated excellent stability over 15 h of continuous long-term monitoring. The remarkable stability of assembled self-powered glucose biosensor in this work could inspire the application of enzymatic biosensors in biometrics, chronic disease management and clinical diagnosis.


Asunto(s)
Técnicas Biosensibles , Glucosa , Estructuras Metalorgánicas , Nanofibras , Celulosa/análogos & derivados , Glucosa/análisis , Humanos
9.
Pathol Res Pract ; 216(12): 153266, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33197838

RESUMEN

MicroRNAs (miRNAs) are a group of highly conserved, short (18-25 nucleotide long) non-coding RNAs which play important functional roles in cellular differentiation, biological development, pathogenesis and disease susceptibility and have been linked to both tumorigenesis and the malignant progression of various cancers. miRNAs primarily exert their function through the negative regulation of their target gene's transcription via the specific recognition of their 3' untranslated region. A single miRNA can regulate multiple target genes and most miRNAs are controlled by several factors. Recent studies have shown that microRNA-149 (miR-149) plays a pivotal role in the pathogenesis of digestive system cancers and may act as a potential diagnostic marker and therapeutic target. In this review, we summarize and discuss the most recent reports describing miR-149 in digestive system cancers, including its single nucleotide polymorphisms, expression levels, target genes, drug sensitivity and clinical significance.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias del Sistema Digestivo/metabolismo , MicroARNs/metabolismo , Regiones no Traducidas 3' , Animales , Antineoplásicos/uso terapéutico , Sitios de Unión , Biomarcadores de Tumor/genética , Quimioradioterapia , Neoplasias del Sistema Digestivo/genética , Neoplasias del Sistema Digestivo/patología , Neoplasias del Sistema Digestivo/terapia , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica , Humanos , MicroARNs/genética , Polimorfismo de Nucleótido Simple , Pronóstico , Transducción de Señal
11.
Environ Sci Pollut Res Int ; 27(35): 44482-44493, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32772284

RESUMEN

Watershed models are cost-effective and powerful tools for evaluating and controlling non-point source pollution (NPSP), while the reliability of watershed models in a management context depends largely on inherent uncertainties in model predictions. The objective of this study is to present the use of multi-model ensemble applied to streamflow, total nitrogen (TN), and total phosphorus (TP) simulation and quantify the uncertainty resulting from model structure. In this study, three watershed models, which have different structures in simulating NPSP, were selected to conduct watershed monthly streamflow, TN load, and TP load ensemble simulation and 90% credible intervals based on Bayesian model averaging (BMA) method. The result using the observed data of the Yixunhe watershed revealed that the coefficient of determination and Nash-Sutcliffe coefficient of the BMA model simulate streamflow, TN load, and TP load were better than that of the single model. The higher the efficiency of a single model is, the greater the weight during the BMA ensemble simulation is. The 90% credible interval of BMA has a high coverage of measured values in this study. This indicates that the BMA method can not only provide simulation with better precision through ensemble simulation but also provide quantitative evaluation of the model structure through interval, which could offer rich information of the NPSP simulation and management.


Asunto(s)
Contaminación Difusa , Contaminantes Químicos del Agua , Teorema de Bayes , China , Monitoreo del Ambiente , Modelos Teóricos , Nitrógeno/análisis , Fósforo/análisis , Reproducibilidad de los Resultados , Ríos , Incertidumbre , Contaminantes Químicos del Agua/análisis
12.
Anal Bioanal Chem ; 412(27): 7395-7404, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32851458

RESUMEN

G-Quadruplexes (G4s) are thermodynamically stable, compact, and poorly hydrated structures that pose a potent obstacle for chromosome replication and gene expression, and requiring resolution by helicases in a cell. Bulk stopped-flow fluorescence assays have provided many mechanistic insights into helicase-mediated duplex DNA unwinding. However, to date, detailed studies on intramolecular G-quadruplexes similar or comparable with those used for studying duplex DNA are still lacking. Here, we describe a method for the direct and quantitative measurement of helicase-mediated intramolecular G-quadruplex unfolding in real time. We designed a series of site-specific fluorescently double-labeled intramolecular G4s and screened appropriate substrates to characterize the helicase-mediated G4 unfolding. With the developed method, we determined, for the first time to our best knowledge, the unfolding and refolding constant of G4 (≈ 5 s-1), and other relative parameters under single-turnover experimental conditions in the presence of G4 traps. Our approach not only provides a new paradigm for characterizing helicase-mediated intramolecular G4 unfolding using stopped-flow assays but also offers a way to screen for inhibitors of G4 unfolding helicases as therapeutic drug targets. Graphical abstract.


Asunto(s)
ARN Helicasas DEAD-box/metabolismo , Proteínas de Drosophila/metabolismo , Pruebas de Enzimas/métodos , G-Cuádruplex , RecQ Helicasas/metabolismo , Animales , ADN/química , ADN/metabolismo , Drosophila/enzimología , Humanos , Cinética , Espectrometría de Fluorescencia/métodos , Especificidad por Sustrato
13.
Cell Death Discov ; 6: 33, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32377396

RESUMEN

Bronchopulmonary dysplasia (BPD) is the leading cause of chronic lung disease in preterm neonates. Extracellular matrix (ECM) abnormalities reshape lung development, contributing to BPD progression. In the present study, we first discovered that the ECM component fibronectin was reduced in the pulmonary tissues of model mice with BPD induced by lipopolysaccharide (LPS) and hyper-oxygen. Meanwhile, interleukin-33 (IL-33) and other inflammatory cytokines were elevated in BPD lung tissues. LPS stimulated the production of IL-33 in alveolar epithelial cells via myeloid differentiation factor 88 (MyD88), protein 38 (p38), and nuclear factor-kappa B (NF-κB) protein 65 (p65). Following the knockout of either IL-33 or its receptor suppression of tumorigenicity 2 (ST2) in mice, BPD disease severity was improved, accompanied by elevated fibronectin. ST2 neutralization antibody also relieved BPD progression and restored the expression of fibronectin. IL-33 induced the formation of neutrophil extracellular traps (NETs), which degraded fibronectin in alveolar epithelial cells. Moreover, DNase-mediated degradation of NETs was protective against BPD. Finally, a fibronectin inhibitor directly decreased fibronectin and caused BPD-like disease in the mouse model. Our findings may shed light on the roles of IL-33-induced NETs and reduced fibronectin in the pathogenesis of BPD.

14.
Plant Cell Physiol ; 61(7): 1365-1380, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32392327

RESUMEN

Anthocyanin biosynthesis is mainly controlled by MYB-bHLH-WD40 (MBW) complexes that modulate the expression of anthocyanin biosynthetic genes (ABGs). The MYB regulators involved in anthocyanin biosynthesis arose early during plant evolution and thus might function divergently in different evolutionary lineages. Although the anthocyanin-promoting R2R3-MYB regulators in eudicots have been comprehensively explored, little consensus has been reached about functional discrepancies versus conservation among MYB regulators from different plant lineages. Here, we integrated transcriptome analysis, gene expression profiles, gain-of-function experiments and transient protoplast transfection assays to functionally characterize the monocot Freesia hybrida anthocyanin MYB regulator gene FhPAP1, which showed correlations with late ABGs. FhPAP1 could activate ABGs as well as TT8-clade genes FhTT8L, AtTT8 and NtAN1 when overexpressed in Freesia, Arabidopsis and tobacco, respectively. Consistently, FhPAP1 could interact with FhTT8L and FhTTG1 to form the conserved MBW complex and shared similar target genes with its orthologs from Arabidopsis. Most prominently, FhPAP1 displayed higher transactivation capacity than its homologs in Arabidopsis and tobacco, which was instantiated in its powerful regulation on ABGs. Moreover, we found that FhPAP1 might be the selected gene during the domestication and rapid evolution of the wild Freesia species to generate intensive flower pigmentation. These results showed that while the MBW complex was highly evolutionarily conserved between tested monocot and core eudicot plants, participating MYB regulators showed functional differences in transactivation capacity according to their activation domain and played important roles in the flower coloration domestication and evolution of angiosperms.


Asunto(s)
Antocianinas/biosíntesis , Flores/metabolismo , Iridaceae/metabolismo , Factores de Transcripción/fisiología , Arabidopsis , Clonación Molecular , Secuencia Conservada , Regulación de la Expresión Génica de las Plantas/genética , Genes de Plantas/genética , Genes de Plantas/fisiología , Iridaceae/genética , Iridaceae/fisiología , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiología , Plantas Modificadas Genéticamente , Reacción en Cadena en Tiempo Real de la Polimerasa , Alineación de Secuencia , Factores de Transcripción/genética
15.
J Agric Food Chem ; 68(23): 6420-6429, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-32396340

RESUMEN

In this study, sugary maize dendrimer-like glucan (SMDG) was used as a delivery carrier for improving the bioavailability of resveratrol (RES). After optimization, the solubility of RES in RES-SMDG markedly increased to approximately 9.1 times that of the raw RES solution. The structural characterizations of the RES-SMDG formulation showed crystal RES was entrapped in the SMDG matrix for the amorphous state due to the strong intermolecular hydrogen bonds between the -OH of RES and glucan chains. In this case, antioxidant activity of RES-SMDG was markedly higher than that of the raw RES solution. In the Caco-2 cell model, the Papp value of RES in the RES-SMDG group was slightly higher than those of common permeable compounds, while the cellular uptake was significantly improved. RES-SMDG also exhibited protective effects against cellular damage under oxidative stress. The results indicated that SMDG is an attractive carrier to encapsulate and protect hydrophilic bioactive ingredients.


Asunto(s)
Dendrímeros/química , Portadores de Fármacos/química , Glucanos/química , Resveratrol/química , Disponibilidad Biológica , Células CACO-2 , Sistemas de Liberación de Medicamentos , Humanos , Nanopartículas/química , Estrés Oxidativo/efectos de los fármacos , Tamaño de la Partícula , Resveratrol/farmacología
16.
Food Funct ; 11(3): 2543-2554, 2020 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-32150182

RESUMEN

A novel amylopectin-based cyclic architecture was fabricated, arising from microbial branching enzyme treated waxy rice starch. The recombinant enzyme had a molecular weight of 72.0 kDa, and exhibited optimum activity at pH 7.0 and 75 °C. During the cyclization reaction catalyzed by a branching enzyme, the molecular weight of amylopectin rapidly decreased for the initial 2 h, and then very slowly decreased, tapering off at approximately 1.8 × 105 g mol-1 at 12 h. The number of A-chain fractions greatly increased, whereas the percentage of B-chain fractions decreased after enzymatic modification, accompanied by more α-1, 6 linkage formation. The core ring structure as a glucoamylase-resistant fraction had a number-average degree of polymerization of 21, which was constructed by 19 glucose units linked with, 2 glucosyl stubs at the O-6-position of the cyclic glucan through α-1,4 and α-1,6 linkages. Similar to large-ring cyclodextrin with equal glucose units, this cyclic glucan had a cavity geometry with two-circular loops and short stubs in perpendicular planes. Moreover, this cyclic glucan could complex with iodine for the host-guest formation. These results revealed the potential application of the amylopectin-based cyclic glucan as a good delivery system to encapsulate and protect bioactive ingredients.


Asunto(s)
Amilopectina/química , Amilopectina/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucano/metabolismo , Amilopectina/biosíntesis , Proteínas Bacterianas/metabolismo , Biotecnología , Fenómenos Químicos , Ciclización , Geobacillus stearothermophilus/enzimología , Hidrólisis , Peso Molecular , Oryza , Almidón
17.
ACS Omega ; 5(10): 5534-5539, 2020 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-32201846

RESUMEN

Organometallic sandwich complexes, composed of cyclic hydrocarbon ligands and transition-metal atoms, display unique physical and chemical properties. In this work, the electronic and spin transport properties of one-dimensional (1D) VBz2 ligand bimetallic sandwich complexes, VBz2-TM (TM = Cr, Mn, and Fe), are systematically investigated using density functional theory and nonequilibrium Green's function method. The results show that all the 1D infinite molecular wires [(VBz2)TM]∞ (TM = Cr-Fe) are found to be thermodynamically stable with high binding energies (∼1.0-3.45 eV). In particular, they are predicted to be ferromagnetic half metals. Moreover, the I-V curves exhibit negative differential resistance for one, two, and three VBz2-TM wires at TM = Cr, Mn, and Fe, respectively, which is of great significance for certain electronic applications. Our findings strongly suggest that the benzene ligand bimetallic sandwich molecular wires are good candidates for potential electronics and spintronics.

18.
Carbohydr Polym ; 234: 115908, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32070527

RESUMEN

The structure and properties of phytoglycogen (PG) and waxy starch (WS) from different mutants subjected to carboxymethylation (CM) were investigated. FT-IR analysis confirmed the carboxymethylation of PG and WS. The degree of substitution (DS) increased with increasing of the ratio of monochloroacetic acid to anhydroglucose unit, while DS of CM-PG was higher than that of CM-WS using equivalent modification conditions. The weight-average molecular weight (Mw) and radius of gyration (Rz) of CM-WS increased with the DS, whereas the Mw increased and Rz was nearly constant for CM-PG. The zeta-potential of CM-WS reduced and the viscosity increased significantly as DS increased, while the viscosity of CM-PG was remarkably lower than that of CM-WS with equivalent of DS. The increase of DS in CM-starches resulted in a substantial reduction of RDS accompanied by the increase of SDS and RS. The results revealed the promising application of CM-PG as a potential carrier system for bioactive ingredients.

19.
J Hazard Mater ; 392: 122212, 2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-32078968

RESUMEN

Polybrominated diphenyl ethers (PBDEs) are ubiquitous in marine ecosystems and have been suggested to bioaccumulate in aquatic food webs, with potentially negative impacts on marine organism. In this study, a 21-day experiment was performed under controlled laboratory conditions, in which 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), the most biotoxic PBDE in the marine environment, was fed to rainbow trout (Oncorhynchus mykiss) at concentrations of 50 and 500 ng g-1 in the diet. BDE-47 significantly decreased the specific growth rate of O. mykiss and was highly concentrated in the liver and head kidney, as evidenced by increased bioaccumulation factor (BAF) values. Tissue observation revealed impairment of the microstructure of the head kidney. Important immune factors in the skin, blood and head kidney were significantly inhibited by BDE-47 treatment (p < 0.05), whereas the respiratory burst activity of macrophages was enhanced. Additionally, immune-related genes were strongly downregulated following BDE-47 exposure (p < 0.05). In a bacterial challenge, the treatment groups had much higher mortality than did the control group (p < 0.05). BDE-47 accumulated and impaired immune organs, and the hierarchy of immune responses was impaired, consequently reducing O. mykiss resistance to pathogen invasion.


Asunto(s)
Éteres Difenilos Halogenados/toxicidad , Oncorhynchus mykiss/inmunología , Contaminantes Químicos del Agua/toxicidad , Animales , Complemento C3/inmunología , Mucosa Gástrica/metabolismo , Éteres Difenilos Halogenados/farmacocinética , Riñón Cefálico/efectos de los fármacos , Riñón Cefálico/inmunología , Riñón Cefálico/metabolismo , Riñón Cefálico/patología , Recuento de Leucocitos , Hígado/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Muramidasa/inmunología , Músculos/metabolismo , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/metabolismo , Oncorhynchus mykiss/microbiología , Estallido Respiratorio/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/inmunología , Vibrio , Vibriosis/inmunología , Vibriosis/mortalidad , Vibriosis/veterinaria , Contaminantes Químicos del Agua/farmacocinética
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