Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Exp Cell Res ; 434(2): 113892, 2024 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-38104646

RESUMEN

As a crucial gene associated with diseases, the SLC29A3 gene encodes the equilibrative nucleoside transporter 3 (ENT3). ENT3 plays an essential regulatory role in transporting intracellular hydrophilic nucleosides, nucleotides, hydrophilic anticancer and antiviral nucleoside drugs, energy metabolism, subcellular localization, protein stability, and signal transduction. The mutation and inactivation of SLC29A3 are intimately linked to the occurrence, development, and prognosis of various human tumors. Moreover, many hereditary human diseases, such as H syndrome, pigmentary hypertrichosis and non-autoimmune insulin-dependent diabetes mellitus (PHID) syndrome, Faisalabad histiocytosis (FHC), are related to SLC29A3 mutations. This review explores the mechanisms of SLC29A3 mutations and expression alterations in inherited disorders and cancers. Additionally, we compile studies on the inhibition of ENT3, which may serve as an effective strategy to potentiate the anticancer activity of chemotherapy. Thus, the synopsis of genetics, permeant function and drug therapy of ENT3 provides a new theoretical and empirical foundation for the diagnosis, prognosis of evaluation and treatment of various related diseases.


Asunto(s)
Diabetes Mellitus Tipo 2 , Histiocitosis , Neoplasias , Humanos , Nucleótidos/metabolismo , Mutación , Histiocitosis/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Nucleósidos/genética , Proteínas de Transporte de Nucleósidos/metabolismo
2.
Eur J Pediatr ; 183(1): 51-60, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37861791

RESUMEN

The effect of renal functional status on drug metabolism is a crucial consideration for clinicians when determining the appropriate dosage of medications to administer. In critically ill patients, there is often a significant increase in renal function, which leads to enhanced drug metabolism and potentially inadequate drug exposure. This phenomenon, known as augmented renal clearance (ARC), is commonly observed in pediatric critical care settings. The findings of the current study underscore the significant impact of ARC on the pharmacokinetics and pharmacodynamics of antimicrobial drugs in critically ill pediatric patients. Moreover, the study reveals a negative correlation between increased creatinine clearance and blood concentrations of antimicrobial drugs. The article provides a comprehensive review of ARC screening in pediatric patients, including its definition, risk factors, and clinical outcomes. Furthermore, it summarizes the dosages and dosing regimens of commonly used antibacterial and antiviral drugs for pediatric patients with ARC, and recommendations are made for dose and infusion considerations and the role of therapeutic drug monitoring. CONCLUSION:  ARC impacts antimicrobial drugs in pediatric patients. WHAT IS KNOWN: • ARC is inextricably linked to the failure of antimicrobial therapy, recurrence of infection, and subtherapeutic concentrations of drugs. WHAT IS NEW: • This study provides an updated overview of the influence of ARC on medication use and clinical outcomes in pediatric patients. • In this context, there are several recommendations for using antibiotics in pediatric patients with ARC: 1) increase the dose administered; 2) prolonged or continuous infusion administration; 3) use of TDM; and 4) use alternative drugs that do not undergo renal elimination.


Asunto(s)
Antibacterianos , Enfermedad Crítica , Humanos , Niño , Enfermedad Crítica/terapia , Antibacterianos/uso terapéutico , Riñón/metabolismo , Pruebas de Función Renal , Eliminación Renal
3.
Molecules ; 28(22)2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-38005193

RESUMEN

Type 2 diabetes mellitus (T2DM) is an increasingly prevalent and serious health problem. Its onset is typically associated with metabolic disorders and disturbances in the gut microbiota. Previous studies have reported the anti-T2DM effects of Pueraria thomsonii Radix as a functional food. However, the mechanism of action is still unknown. In this study, rich polyphenols and polysaccharides from Pueraria Thomsonii Radix water extract (PTR) were quantitatively determined, and then the effects of PTR on db/db mice were evaluated by pharmacology, metabolomics, and 16S rRNA gene sequencing. The results showed that PTR could alleviate pancreatic tissue damage, significantly decrease fasting blood glucose (FBG), fasting serum insulin (FINS), homeostasis model assessment insulin resistance (HOMA-IR), urinary glucose (UGLU), and urinary albumin/creatinine ratio (UACR). Metabolomics showed that the Diabetes Control (DM) group produced 109 differential metabolites, of which 74 could be regulated by PTR. In addition, 16S rRNA sequencing was performed in fecal samples and results showed that PTR could reduce the Firmicutes/Bacteroidetes(F/B) ratio and regulate three beneficial bacteria and one harmful bacterium. In conclusion, the results showed that PTR could ameliorate the T2DM symptoms, metabolic disorder, and gut microbiota imbalance of db/db mice, and it was superior to metformin in some aspects. We suggested for the first time that γ-aminobutyric acid (GABA) may be involved in the regulation of the microbiota-gut-brain axis (MGB) and thus affects the metabolic disorders associated with T2DM. This study will provide a scientific basis for the development of functional food with PTR.


Asunto(s)
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Metformina , Pueraria , Ratones , Animales , Diabetes Mellitus Tipo 2/metabolismo , Pueraria/metabolismo , ARN Ribosómico 16S/genética , Metformina/farmacología , Bacterias/metabolismo , Glucemia/metabolismo
4.
Water Sci Technol ; 86(9): 2358-2374, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36378185

RESUMEN

The effect of potassium ferrate (PF) and straw fiber (SF) on the strength of cement-based solidified municipal sludge, including the influence of reducing the organic matter in the sludge on the efficiency of the hydration of the cement, was studied. Single-factor tests, orthogonal tests, and linear weighted optimization methods were used to obtain suitable ratios to meet practical requirements, and then SEM and XRD analyses were used to explore the solidification mechanism. The results showed that PF and SF had significant influence on the strength, with SF having the greatest influence and the strength increasing with the amount of both admixtures, and cement had no significant influence on the strength. After linear weighting optimization, the ideal dosage was found to be 20% cement, 20% PF, and 5% SF, which produced a solidified sludge that had an strength of 126.87 kPa, far higher than the 50 kPa required to qualify for disposal in landfills. Analysis of the mineral content and microstructure showed that PF and SF could promote cement hydration and produce more hydration products, and the density of the optimized sample was much higher than that of the raw sludge and a sludge sample mixed with 20% cement alone.


Asunto(s)
Compuestos de Hierro , Aguas del Alcantarillado , Aguas del Alcantarillado/química , Materiales de Construcción/análisis , Compuestos de Potasio
5.
BMC Endocr Disord ; 19(1): 29, 2019 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30849982

RESUMEN

BACKGROUND: To determine the relation between daily glycemic fluturation and the intestinal mucosal barrier dysfunction in type 2 diabetes mellitus (T2DM). METHODS: Totally 66 patients with T2DM were enrolled, 33 healthy volunteers were also recruited according to the enrolled patients' gender and age in a ratio of 2: 1. Patients were bisected by the median of endotoxins level into low(< 12.31 µ/l, n = 33) and high(≥12.31 µ/l, n = 33) blood endotoxin groups. Clinical data and blood glucose fluctuations were compared between groups. Multivariate regression analysis was used to determine the independent factors affecting the intestinal mucosal barrier. RESULTS: Serum endotoxin [12.1 (4.2~22.0) vs 3.2 (1.3~6.0), P < 0.001] and fasting blood glucose levels [9.8 ± 3.6 vs 5.4 ± 0.7, P < 0.001] were significantly higher in patients with T2DM than the control group. The standard deviation of blood glucose (SDBG) within 1 day [2.9 (2.0~3.3) vs. 2.1 (1.6~2.5), P = 0.012] and the largest amplitude of glycemic excursions (LAGE) [7.5 (5.4~8.9) vs. 5.9 (4.3~7.4), P = 0.034] were higher in the high endotoxin group than in the low endotoxin group. A multiple linear stepwise regression revealed a positive correlation between SDBG with endotoxin (standard partial regression coefficient = 0.255, P = 0.039). CONCLUSIONS: T2DM patients who incapable of maintaining stable blood glucose level are at a higher risk to associated with intestinal mucosal barrier injury.


Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , Hiperglucemia/complicaciones , Hipoglucemia/complicaciones , Enfermedades Intestinales/etiología , Biomarcadores/análisis , Permeabilidad de la Membrana Celular , China/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Hiperglucemia/epidemiología , Hipoglucemia/epidemiología , Incidencia , Enfermedades Intestinales/patología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos
6.
BMC Pulm Med ; 19(1): 162, 2019 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-31455270

RESUMEN

BACKGROUND: To compare the microbiological culture within endotracheal aspirate specimens (ETAs) and endotracheal tube specimens (ETTs) in patients undergoing mechanical ventilation (MV) by statistical tools. METHOD: ETAs and ETTs from a total number of 81 patients, who were undergoing MV at the intensive care unit (ICU) of Jiading Central Hospital Affiliated Shanghai University of Medicine & Health Sciences from September 1st, 2017 to August 31st, 2018, were collected for microbiological culture analysis. Correlation of ETAs and ETTs cultures were obtained by Spear-men correlation analysis, while the consistency of the two specimens was determined by Kappa analysis and principal component analysis (PCA). RESULTS: Microbiological culture from both ETAs and ETTs showed that Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were the main pathogens, with Spear-man correlation coefficients of 0.676, 0.951, 0.730 and 0.687 respectively (all P < 0.01), and the overall Spear-man correlation coefficient is 0.757 (P < 0.01). This result shows that two samples were positively correlated. Kappa analysis also revealed high consistency of the microbial culture results from the ETAs and the ETTs (overall κ = 0.751, P < 0.01). The κ values for the four bacteria detected were 0.670, 0.949, 0.723, and 0.687, respectively (all P < 0.001). PCA also revealed high similarity. CONCLUSION: Combining microbiological culture and statistical analysis of samples collected from 81 patients who were undergoing MV in ICU, we showed that microbe found in the ETAs had high similarity with that found in the ETTs which collected at the end of the catheters. In clinical practice, ETAs analysis is easily accessible meanwhile provides a valuable information for MV patients.


Asunto(s)
Biopelículas , Contaminación de Equipos , Intubación Intratraqueal/efectos adversos , Respiración Artificial/efectos adversos , Infecciones del Sistema Respiratorio/etiología , Tráquea/microbiología , Adulto , Anciano , Anciano de 80 o más Años , China , Recuento de Colonia Microbiana , Femenino , Bacterias Gramnegativas , Bacterias Grampositivas , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Infecciones del Sistema Respiratorio/mortalidad
7.
Neurol Sci ; 37(7): 1107-12, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27021564

RESUMEN

Vulnerable carotid plaque easily ruptures and causes cerebral infarction. Plaque inflammation and neovascularization have both been shown as important characteristics in vulnerable plaque. We assessed neovascularization within carotid plaque using contrast-enhanced ultrasound, and also assessed inflammation, using high sensitivity C-reactive protein (hs-CRP) testing, in acute cerebral infarction patients. A total of 106 patients with acute cerebral infarction and 40 controls were enrolled in the study. All subjects had been previously found to have carotid atherosclerotic plaques, and the plaques were classified as soft plaque, hard plaque, mixed plaque, and calcified plaque, using carotid artery ultrasound. Contrast-enhanced ultrasound was performed on the plaques for quantitative analysis and hs-CRP levels were measured. The results showed that plaque enhancement was present in 81.1 % of cerebral infarction patients and 40.0 % of controls. The contrast parameters for cerebral infarction patients were significantly different from controls. For cerebral infarction patients, soft plaque showed the highest enhanced percentage, 95.1 %, with contrast parameters significantly different to other types of plaque. The hs-CRP levels of enhanced cerebral infarction patients were higher than in non-enhanced patients. Correlation analysis in cerebral infarction patients showed that hs-CRP levels were closely related to the contrast parameters. Acute cerebral infarction patients showed intense contrast enhancement and inflammation in carotid plaque, and different types of plaque had various degrees of enhancement, suggesting that contrast-enhanced ultrasound and hs-CRP might be used for plaque risk stratification.


Asunto(s)
Proteína C-Reactiva/metabolismo , Infarto Cerebral , Neovascularización Patológica , Adulto , Anciano , Anciano de 80 o más Años , Infarto Cerebral/complicaciones , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/metabolismo , Medios de Contraste/farmacocinética , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neovascularización Patológica/complicaciones , Neovascularización Patológica/diagnóstico por imagen , Neovascularización Patológica/metabolismo , Estadística como Asunto , Tomógrafos Computarizados por Rayos X , Ultrasonografía
8.
Front Cell Infect Microbiol ; 14: 1380312, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38836055

RESUMEN

Legionella, one of the main pathogens that causes community-acquired pneumonia, can lead to Legionella pneumonia, a condition characterized predominantly by severe pneumonia. This disease, caused by the bacterium Legionella pneumophila, can quickly progress to critical pneumonia and is often associated with damage to multiple organs. As a result, it requires close attention in terms of clinical diagnosis and treatment. Omadacycline, a new type of tetracycline derivative belonging to the aminomethylcycline class of antibiotics, is a semi-synthetic compound derived from minocycline. Its key structural feature, the aminomethyl modification, allows omadacycline to overcome bacterial resistance and broadens its range of effectiveness against bacteria. Clinical studies have demonstrated that omadacycline is not metabolized in the body, and patients with hepatic and renal dysfunction do not need to adjust their dosage. This paper reports a case of successful treatment of Legionella pneumonia with omadacycline in a patient who initially did not respond to empirical treatment with moxifloxacin. The patient also experienced electrolyte disturbance, as well as dysfunction in the liver and kidneys, delirium, and other related psychiatric symptoms.


Asunto(s)
Antibacterianos , Legionella pneumophila , Enfermedad de los Legionarios , Tetraciclinas , Humanos , Tetraciclinas/uso terapéutico , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Enfermedad de los Legionarios/tratamiento farmacológico , Enfermedad de los Legionarios/microbiología , Legionella pneumophila/efectos de los fármacos , Resultado del Tratamiento , Masculino , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/microbiología , Moxifloxacino/uso terapéutico , Persona de Mediana Edad
9.
Int J Biol Sci ; 20(5): 1652-1668, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38481812

RESUMEN

Liquid-liquid phase separation (LLPS) is a physiological phenomenon that parallels the mixing of oil and water, giving rise to compartments with diverse physical properties. Biomolecular condensates, arising from LLPS, serve as critical regulators of gene expression and control, with a particular significance in the context of malignant tumors. Recent investigations have unveiled the intimate connection between LLPS and cancer, a nexus that profoundly impacts various facets of cancer progression, including DNA repair, transcriptional regulation, oncogene expression, and the formation of critical membraneless organelles within the cancer microenvironment. This review provides a comprehensive account of the evolution of LLPS from the molecular to the pathological level. We explore the mechanisms by through which biomolecular condensates govern diverse cellular physiological processes, encompassing gene expression, transcriptional control, signal transduction, and responses to environmental stressors. Furthermore, we concentrate on potential therapeutic targets and the development of small-molecule inhibitors associated with LLPS in prevalent clinical malignancies. Understanding the role of LLPS and its interplay within the tumor milieu holds promise for enhancing cancer treatment strategies, particularly in overcoming drug resistance challenges. These insights offer innovative perspectives and support for advancing cancer therapy.


Asunto(s)
Neoplasias , Separación de Fases , Humanos , Neoplasias/genética , Neoplasias/terapia , Reparación del ADN , Uniones Comunicantes , Oncogenes , Microambiente Tumoral/genética
10.
J Chem Phys ; 139(5): 055102, 2013 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-23927287

RESUMEN

The human Islet Amyloid Polypeptide (hIAPP) is the major constituent of amyloid deposits in pancreatic islets of type-II diabetes. IAPP is secreted together with insulin from the acidic secretory granules at a low pH of approximately 5.5 to the extracellular environment at a neutral pH. The increased accumulation of extracellular hIAPP in diabetes indicates that changes in pH may promote amyloid formation. To gain insights and underlying mechanisms of the pH effect on hIAPP fibrillogenesis, all-atom molecular dynamics simulations in explicit solvent model were performed to study the structural properties of five hIAPP protofibrillar oligomers, under acidic and neutral pH, respectively. In consistent with experimental findings, simulation results show that acidic pH is not conducive to the structural stability of these oligomers. This provides a direct evidence for a recent experiment [L. Khemtemourian, E. Domenech, J. P. F. Doux, M. C. Koorengevel, and J. A. Killian, J. Am. Chem. Soc. 133, 15598 (2011)], which suggests that acidic pH inhibits the fibril formation of hIAPP. In addition, a complementary coarse-grained simulation shows the repulsive electrostatic interactions among charged His18 residues slow down the dimerization process of hIAPP by twofold. Besides, our all-atom simulations reveal acidic pH mainly affects the local structure around residue His18 by destroying the surrounding hydrogen-bonding network, due to the repulsive interactions between protonated interchain His18 residues at acidic pH. It is also disclosed that the local interactions nearby His18 operating between adjacent ß-strands trigger the structural transition, which gives hints to the experimental findings that the rate of hIAPP fibril formation and the morphologies of the fibrillar structures are strongly pH-dependent.


Asunto(s)
Histidina/química , Polipéptido Amiloide de los Islotes Pancreáticos/química , Algoritmos , Humanos , Concentración de Iones de Hidrógeno , Modelos Moleculares , Conformación Proteica , Electricidad Estática
11.
Front Pharmacol ; 14: 1285522, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37736346

RESUMEN

[This corrects the article DOI: 10.3389/fphar.2023.1192855.].

12.
Front Pharmacol ; 14: 1192855, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37576806

RESUMEN

Introduction: In the past decade, super-enhancer (SE) has become a research hotspot with increasing attention on cancer occurrence, development, and prognosis. To illustrate the hotspots of SE in cancer research and its evolutionary tendency, bibliometric analysis was carried out for this topic. Methods: Literature published before Dec 31, 2022, in WOSCC, was systematically classified, and Citespace, bibliometric.com/app, and GraphPad Prism analyzed the data. Results: After screening out inappropriate documents and duplicate data, 911 publications were selected for further bibliometric analysis. The top five research areas were Oncology (257, 28.211%), Cell Biology (210, 23.052%), Biochemistry Molecular Biology (209, 22.942%), Science Technology Other Topics (138, 15.148%), and Genetics Heredity (132, 14.490%). The United States of America (United States) has the highest number of documents (462, 50.71%), followed by China (303, 33.26%). Among the most productive institutions, four of which are from the United States and one from Singapore, the National University of Singapore. Harvard Medical School (7.68%) has the highest percentage of articles. Young, Richard A, with 32 publications, ranks first in the number of articles. The top three authors came from Whitehead Institute for Biomedical Research as a research team. More than two-thirds of the research are supported by the National Institutes of Health of the United States (337, 37.654%) and the United States Department of Health Human Services (337, 37.654%). And "super enhancer" (525), "cell identity" (258), "expression" (223), "cancer" (205), and "transcription factor" (193) account for the top 5 occurrence keywords. Discussion: Since 2013, SE and cancer related publications have shown a rapid growth trend. The United States continues to play a leading role in this field, as the top literature numbers, affiliations, funding agencies, and authors were all from the United States, followed by China and European countries. A high degree of active cooperation is evident among a multitude of countries. The role of SEs in cell identity, gene transcription, expression, and inhibition, as well as the relationship between SEs and TFs, and the selective inhibition of SEs, have received much attention, suggesting that they are hot issues for research.

13.
Front Public Health ; 11: 1291458, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38179562

RESUMEN

Introduction: There is a growing body of recent literature linking the association of specific or multiple lifestyles with cognitive impairment, but most of these studies have been conducted in Western populations, and it is necessary to study multiple lifestyles and cognitive abilities in different populations, with the primary population of this study being a select group of community-dwelling older adults in Shanghai, China. Methods: The sample included 2,390 community-dwelling Chinese participants. Their cognitive function was assessed using the Mini-Mental State Examination (MMSE). We defined a healthy lifestyle score on the basis of being non-smoking, performing ≥210 min/wk moderate/vigorous-intensity physical activity, having light to moderate alcohol consumption, eating vegetables and fruits daily, having a body mass index (BMI) of 18.5-23.9 kg/m2, and having a waist-to-hip ratio (WHR) <0.90 for men and <0.85 for women, for an overall score ranging from 0 to 6. Results: Compared with participants with ≤2 healthy lifestyle factors, the adjusted odds ratio (OR) and 95% confidence interval (CI) for participants with 4, 5, and 6 healthy lifestyle factors were 0.53 (95% CI, 0.29-0.98), 0.40 (95% CI, 0.21-0.75), and 0.36 (95% CI, 0.16-0.79), respectively. Only WHR (OR = 0.54, 95% CI = 0.37-0.78) and physical activity (OR = 0.69, 95% CI = 0.51-0.92) were associated with cognitive impairment. A healthy lifestyle correlated with overall cognition (ß = 0.066, orientation (ß = 0.049), language ability (ß = 0.060), delayed recall (ß = 0.045) and executive function (ß = 0.044) (P all < 0.05). Conclusion: The study provides evidence on an inverse association between healthy lifestyles and cognitive impairment. We investigated whether healthy lifestyle was related to specific cognitive functions to provide a theoretical basis for accurate clinical prescription.


Asunto(s)
Disfunción Cognitiva , Vida Independiente , Masculino , Humanos , Femenino , Anciano , Vida Independiente/psicología , China/epidemiología , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/psicología , Estilo de Vida Saludable , Cognición
14.
Front Pharmacol ; 14: 1137975, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37564179

RESUMEN

Objectives: Augmented renal clearance (ARC) is a state of enhanced renal function commonly observed in 30%-65% of critically ill patients despite normal serum creatinine levels. Using unadjusted standard dosing regimens of renally eliminated drugs in ARC patients often leads to subtherapeutic concentrations, poor clinical outcomes, and the emergence of multidrug-resistant bacteria. We summarized pharmaceutical, pharmacokinetic, and pharmacodynamic research on the definition, underlying mechanisms, and risk factors of ARC to guide individualized dosing of antibiotics and various strategies for optimizing outcomes. Methods: We searched for articles between 2010 and 2022 in the MEDLINE database about ARC patients and antibiotics and further provided individualized antibiotic dosage regimens for patients with ARC. Results: 25 antibiotic dosage regimens for patients with ARC and various strategies for optimization of outcomes, such as extended infusion time, continuous infusion, increased dosage, and combination regimens, were summarized according to previous research. Conclusion: ARC patients, especially critically ill patients, need to make individualized adjustments to antibiotics, including dose, frequency, and method of administration. Further comprehensive research is required to determine ARC staging, expand the range of recommended antibiotics, and establish individualized dosing guidelines for ARC patients.

15.
Sci Rep ; 13(1): 7660, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37169857

RESUMEN

The high content of organic matter in sludge is the primary reason for the poor solidifying effect and excessive dosage of the cement base. In this study, potassium ferrate and straw fiber are utilized to synergistically enhance the solidifying effect of the cement and elaborate the strength mechanisms. Among them, potassium ferrate was selected to oxidize and crack the structure of organic matter in sludge and consume part of organic matter; straw fiber was used as an adsorption material to absorb some of the organic material and reduce its interference with the cement hydration reaction; the skeleton function of straw fiber in solidified sludge was used to improve the final solidified sludge strength. It is shown that the presence of these two additives significantly improved the cement solidification strength and reduced the moisture content of the solidified body. Moreover, the moisture content and strength followed an obvious linear relationship (adjusted R2 = 0.92), with the strength increasing as the moisture content decreased. After pretreatment with potassium ferrate, the free water content in the dewatered sludge increased by 4.5%, which was conducive to the adequate hydration reaction with cement. The analysis using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), and mercury intrusion porosimetry (MIP) revealed potassium ferrate synergizes with straw fibers to promote the production of hemihydrate gypsum and gismondine. However, hemihydrate gypsum, calcium carbonate, and gismondine resulted in structural swelling, which was confirmed by the microscopic morphology and pore structure analysis. However, the adverse effects due to swelling were offset by the increase in strength brought by the above crystalline substances.

16.
J Biol Chem ; 286(8): 6291-300, 2011 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-21148563

RESUMEN

Abnormal aggregation of islet amyloid polypeptide (IAPP) into amyloid fibrils is a hallmark of type 2 diabetes. In this study, we investigated the initial oligomerization and subsequent addition of monomers to growing aggregates of human IAPP at the residue-specific level using NMR, atomic force microscopy, mass spectroscopy, and computational simulations. We found that in solution IAPPs rapidly associate into transient low-order oligomers such as dimers and trimers via interactions between histidine 18 and tyrosine 37. This initial event is proceeded by slow aggregation into higher-order spherical oligomers and elongated fibrils. In these two morphologically distinct types of aggregates IAPPs adopt structures with markedly different residual flexibility. Here we show that the anti-amyloidogenic compound resveratrol inhibits oligomerization and amyloid formation via binding to histidine 18, supporting the finding that this residue is crucial for on-pathway oligomer formation.


Asunto(s)
Amiloide/química , Polipéptido Amiloide de los Islotes Pancreáticos/química , Multimerización de Proteína , Amiloide/genética , Amiloide/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Polipéptido Amiloide de los Islotes Pancreáticos/genética , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Microscopía de Fuerza Atómica , Resonancia Magnética Nuclear Biomolecular , Resveratrol , Estilbenos/química
17.
Proc Natl Acad Sci U S A ; 106(14): 5517-22, 2009 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-19297622

RESUMEN

In the cell, protein complexes form by relying on specific interactions between their monomers. Excluded volume effects due to molecular crowding would lead to correlations between molecules even without specific interactions. What is the interplay of these effects in the crowded cellular environment? We study dimerization of a model homodimer when the mondimers are free and when they are tethered to each other. We consider a structured environment: Two monomers first diffuse into a cavity of size L and then fold and bind within the cavity. The folding and binding are simulated by using molecular dynamics based on a simplified topology based model. The confinement in the cell is described by an effective molecular concentration C approximately L(-3). A two-state coupled folding and binding behavior is found. We show the maximal rate of dimerization occurred at an effective molecular concentration C(op) approximately = 1 mM, which is a relevant cellular concentration. In contrast, for tethered chains the rate keeps at a plateau when C < C(op) but then decreases sharply when C > C(op). For both the free and tethered cases, the simulated variation of the rate of dimerization and thermodynamic stability with effective molecular concentration agrees well with experimental observations. In addition, a theoretical argument for the effects of confinement on dimerization is also made.


Asunto(s)
Simulación por Computador , Multimerización de Proteína , Termodinámica , Difusión , Cinética , Modelos Moleculares , Unión Proteica , Pliegue de Proteína
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 274: 121034, 2022 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-35248857

RESUMEN

Rapid and reliable animal fur identification has remained a challenge for customs inspection. The accurate distinction between fur types has a significant meaning in implementing the correct tariff policy. A variety of analytical methods have been applied to work on distinguishing animal fur types, with tools of microscopy, molecular testing, mass spectrometry, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. In this research, the capability of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) combined with pattern recognition methods was investigated for the discrimination of animal fur in six types. This work was to explore the non-destructive application of ATR-FTIR technique in discriminant analysis of animal fur. All spectra were collected by ATR-FTIR of the wavenumber ranging from 4000 to 650 cm-1. Data pretreatments included moving average smoothing and multiplicative scatter correction (MSC). Four supervised classification algorithms were chosen to categorize the types of fur: soft independent modeling of class analogy (SIMCA), principal component analysis linear discriminant analysis (PCA-LDA), partial least squares discriminant analysis (PLS-DA), least squares support vector machine (LS-SVM). PLS-DA and LS-SVM were both effective approaches, with a 100% classification accuracy rate. The accuracy of PCA-LDA and SIMCA was 98.33% and 99.44%, respectively. Furthermore, LS-SVM model obtained using Monte-Carlo sampling method also obtained 100% prediction accuracy, while all other methods produced misclassification. LS-SVM corrected the non-linearities for the animal fur FTIR data but also remarkably improved the prediction performance level. The results of this study revealed that the combination of ATR-FTIR and chemometrics has a huge potential for animal fur discrimination.


Asunto(s)
Pelaje de Animal , Quimiometría , Animales , Análisis Discriminante , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal , Espectroscopía Infrarroja por Transformada de Fourier/métodos
19.
Huan Jing Ke Xue ; 43(6): 3253-3261, 2022 Jun 08.
Artículo en Zh | MEDLINE | ID: mdl-35686795

RESUMEN

Surface soil samples collected at 18 sites from the northeast Tibetan Plateau were used to analyze perfluoroalkyl substances (PFASs) via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to study the concentration levels and sources of PFASs. The results showed that 11 PFASs were detected in the soil, and the ω(Σ11PFASs) ranged from 0.043-1.573 ng·g-1 with an average concentration of 0.398 ng·g-1. PFBA displayed the highest concentration level with a mean content of 0.164 ng·g-1, whereas PFHxA was at the lowest level (0.005 ng·g-1). The concentrations of the other PFASs were similar to each other (0.011-0.057 ng·g-1). Generally, PFASs contents in the west and north were higher than that in the southeast, and the alpine condensation effect existed for PFBA. The principal component analysis showed that PFASs in surface soils in the northeast Tibetan Plateau region mainly originated from the atmospheric transport of PFASs and their precursors. Few areas were affected by direct emissions of point source pollution, and the main sources were the industrial production of metals/minerals and other human activities.


Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Contaminantes Químicos del Agua , Ácidos Alcanesulfónicos/análisis , Cromatografía Liquida , Monitoreo del Ambiente , Fluorocarburos/análisis , Humanos , Suelo/química , Espectrometría de Masas en Tándem , Tibet , Contaminantes Químicos del Agua/análisis
20.
Nat Commun ; 13(1): 5739, 2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36180442

RESUMEN

External manipulation of emission colour is of significance for scientific research and applications, however, the general stimulus-responsive colour modulation method requires both stringent control of microstructures and continously adjustment of particular stimuli conditions. Here, we introduce pathways to manipulate the kinetics of time evolution of both intensity and spectral characteristics of X-ray excited afterglow (XEA) by regioselective doping of lanthanide activators in core-shell nanostructures. Our work reported here reveals the following phenomena: 1. The XEA intensities of multiple lanthanide activators are significantly enhanced via incorporating interstitial Na+ ions inside the nanocrystal structure. 2. The XEA intensities of activators exhibit diverse decay rates in the core and the shell and can largely be tuned separately, which enables us to realize a series of core@shell NPs featuring distinct time-dependent afterglow colour evolution. 3. A core/multi-shell NP structure can be designed to simultaneously generate afterglow, upconversion and downshifting to realize multimode time-dependent multicolour evolutions. These findings can promote the development of superior XEA and plentiful spectral manipulation, opening up a broad range of applications ranging from multiplexed biosensing, to high-capacity information encryption, to multidimensional displays and to multifunctional optoelectronic devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA