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1.
Molecules ; 28(13)2023 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-37446629

RESUMEN

The role of catalysis in controlling chemical reactions is crucial. As an important external stimulus regulatory tool, electric field (EF) catalysis enables further possibilities for chemical reaction regulation. To date, the regulation mechanism of electric fields and electrons on chemical reactions has been modeled. The electric field at the single-molecule electronic scale provides a powerful theoretical weapon to explore the dynamics of individual chemical reactions. The combination of electric fields and single-molecule electronic techniques not only uncovers new principles but also results in the regulation of chemical reactions at the single-molecule scale. This perspective focuses on the recent electric field-catalyzed, single-molecule chemical reactions and assembly, and highlights promising outlooks for future work in single-molecule catalysis.


Asunto(s)
Electricidad , Catálisis
2.
BMC Infect Dis ; 21(1): 783, 2021 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-34372767

RESUMEN

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) spreads rapidly among people and causes a pandemic. It is of great clinical significance to identify COVID-19 patients with high risk of death. METHODS: A total of 2169 adult COVID-19 patients were enrolled from Wuhan, China, from February 10th to April 15th, 2020. Difference analyses of medical records were performed between severe and non-severe groups, as well as between survivors and non-survivors. In addition, we developed a decision tree model to predict death outcome in severe patients. RESULTS: Of the 2169 COVID-19 patients, the median age was 61 years and male patients accounted for 48%. A total of 646 patients were diagnosed as severe illness, and 75 patients died. An older median age and a higher proportion of male patients were found in severe group or non-survivors compared to their counterparts. Significant differences in clinical characteristics and laboratory examinations were found between severe and non-severe groups, as well as between survivors and non-survivors. A decision tree, including three biomarkers, neutrophil-to-lymphocyte ratio, C-reactive protein and lactic dehydrogenase, was developed to predict death outcome in severe patients. This model performed well both in training and test datasets. The accuracy of this model were 0.98 in both datasets. CONCLUSION: We performed a comprehensive analysis of COVID-19 patients from the outbreak in Wuhan, China, and proposed a simple and clinically operable decision tree to help clinicians rapidly identify COVID-19 patients at high risk of death, to whom priority treatment and intensive care should be given.


Asunto(s)
COVID-19 , Adulto , China/epidemiología , Árboles de Decisión , Humanos , Recién Nacido , Masculino , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2
3.
Arterioscler Thromb Vasc Biol ; 39(3): e91-e105, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30651001

RESUMEN

Objective- Vascular smooth muscle cells (VSMCs) phenotype modulation is critical for the resolution of vascular injury. Genetic and pharmacological inhibition of PI3Kγ (phosphoinositide 3-kinase γ) exerts anti-inflammatory and protective effects in multiple cardiovascular diseases. This study investigated the role of PI3Kγ and its downstream effector molecules in the regulation of VSMC phenotypic modulation and neointimal formation in response to vascular injury. Approach and Results- Increased expression of PI3Kγ was found in injured vessel wall as well in cultured, serum-activated wild-type VSMCs, accompanied by a reduction in the expression of calponin and SM22α, 2 differentiation markers of VSMCs. However, the injury-induced downregulation of calponin and SM22α was profoundly attenuated in PI3Kγ-/- mice. Pharmacological inhibition and short hairpin RNA knockdown of PI3Kγ (PI3Kγ-KD) markedly attenuated YAP (Yes-associated protein) expression and CREB (cyclic AMP-response element binding protein) activation but improved the downregulation of differentiation genes in cultured VSMCs accompanied by reduced cell proliferation and migration. Mechanistically, activated CREB upregulated YAP transcriptional expression through binding to its promoter. Ectopic expression of YAP strikingly repressed the expression of differentiation genes even in PI3Kγ-KD VSMCs. Moreover, established carotid artery ligation and chimeric mice models demonstrate that deletion of PI3Kγ in naïve PI3Kγ-/- mice as well as in chimeric mice lacking PI3Kγ either in bone marrow or vascular wall significantly reduced neointimal formation after injury. Conclusions- PI3Kγ controls phenotypic modulation of VSMCs by regulating transcription factor CREB activation and YAP expression. Modulating PI3Kγ signaling on local vascular wall may represent a new therapeutic approach to treat proliferative vascular disease.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/fisiología , Proteínas de Ciclo Celular/fisiología , Fosfatidilinositol 3-Quinasa Clase Ib/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/fisiología , Músculo Liso Vascular/patología , Miocitos del Músculo Liso/enzimología , Neointima/fisiopatología , Transducción de Señal/fisiología , Animales , Arteria Carótida Común , Movimiento Celular , Células Cultivadas , Fosfatidilinositol 3-Quinasa Clase Ib/deficiencia , Fosfatidilinositol 3-Quinasa Clase Ib/genética , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Ligadura , Masculino , Ratones , Ratones Endogámicos C57BL , Miocitos del Músculo Liso/patología , Fenotipo , Interferencia de ARN , ARN Interferente Pequeño/genética , Quimera por Radiación , Remodelación Vascular , Proteínas Señalizadoras YAP
4.
Lipids Health Dis ; 19(1): 194, 2020 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-32829708

RESUMEN

BACKGROUND: Whether high-intensity statin treatment provides more clinical benefits compared with standard statin regimens in acute coronary syndrome (ACS) patients remains controversial. This meta-analysis aimed to comparatively assess high-intensity and standard statin regimens for efficacy and safety in patients with ACS. METHODS: The PubMed, EMBASE, and Cochrane Library databases were searched for studies assessing high-intensity vs. standard statin regimens for ACS treatment from inception to April 2020. The publication language was limited to English, and 16 randomized controlled trials were finally included in this study, with a total of 26,497 patients. RESULTS: Compared to the standard statin regimens, the relative ratio (RR) of major adverse cardiovascular events (MACE) in ACS patients treated by high-intensity statin was 0.77 (95%CI, 0.68-0.86; P < 0.00001; prediction interval, 0.56-1.07). In subgroup analysis, high-intensity statin therapy resulted in more clinical benefits regarding MACE compared with standard statin treatment in both Asian (RR = 0.77; 95%CI, 0.61-0.98; P = 0.03) and non-Asian (RR = 0.79; 95%CI, 0.71-0.89; P < 0.0001) patients. Although adverse events were acceptable in patients with ACS administered high-intensity statin therapy, this treatment was associated with a higher rate of adverse events (4.99% vs. 2.98%), including myopathy/myalgia and elevated liver enzymes, as reflected by elevated serum aminotransferase or aminotransferase amounts. CONCLUSION: The current findings indicated that high-intensity statin therapy might be beneficial in patients with ACS, and close monitoring for adverse effects should be performed.


Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Pueblo Asiatico , Bases de Datos como Asunto , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Enfermedades Musculares/tratamiento farmacológico , Mialgia/tratamiento farmacológico
5.
Cardiol Young ; 30(1): 100-106, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31747981

RESUMEN

BACKGROUND: Hypertrophic cardiomyopathy is an autosomal dominant hereditary disease characterised by left ventricular asymmetry hypertrophy. However, our knowledge of the genetic background in hypertrophic cardiomyopathy cases is limited. Here, we aimed to evaluate pathogenic gene mutations in a family with high-risk hypertrophic cardiomyopathy and analyse the genotype/phenotype relationships in this family. METHODS: The proband, her parents, and her niece underwent whole-exome sequencing, and the genotypes of family members were identified using Sanger sequencing. mRNA expression was detected using reverse transcription sequencing. Structural impairments were predicted by homologous modelling. A family survey was conducted for patients with positive results to obtain information on general clinical symptoms, electrocardiography, ambulatory electrocardiography, echocardiography, and 3.0T cardiac magnetic resonance findings. Regular follow-up was performed for up to 6 months. RESULTS: Five family members, including the proband, carried a cleavage site mutation in the MYBPC3 gene (c.2737+1 (IVS26) G>T), causing exon 26 of the MYBPC3 gene transcript to be skipped and leading to truncation of cardiac myosin-binding protein C. Family survey showed that the earliest onset age was 13 years old, and three people had died suddenly at less than 40 years old. Three pathogenic gene carriers were diagnosed with hypertrophic cardiomyopathy, and all showed severe ventricular septal hypertrophy. CONCLUSION: The c.2737+1 (IVS26) G>T mutation in the MYBPC3 gene led to exon 26 skipping, thereby affecting the structure and function of cardiac myosin-binding protein C and leading to severe ventricular hypertrophy and sudden death.


Asunto(s)
Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/genética , Proteínas Portadoras/genética , Adulto , Ecocardiografía , Electrocardiografía , Exones , Familia , Femenino , Genotipo , Heterocigoto , Humanos , Mutación , Linaje , Fenotipo , Secuenciación del Exoma
6.
Am J Pathol ; 188(1): 252-263, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29037856

RESUMEN

The role of platelets in the development of thrombosis and abrupt closure after angioplasty is well recognized. However, the direct impact of platelets on neointima formation after arterial injury remains undetermined. Herein, we show that neointima formation after carotid artery wire injury reduces markedly in CD40-/- apolipoprotein E-deficient (apoE-/-) mice but only slightly in CD40 ligand-/-apoE-/- mice, compared with apoE-/- mice. Wild-type and CD40-deficient platelets were isolated from blood of apoE-/- and CD40-/-apoE-/- mice, respectively. The i.v. injection of thrombin-activated platelets into CD40-/-apoE-/- mice was performed every 5 days, starting at 2 days before wire injury. Injection of wild-type platelets promoted neointima formation, which was associated with increased inflammation by stimulating leukocyte recruitment via up-regulation of circulating platelet surface P-selectin expression and the formation of platelet-leukocyte aggregates. It was also associated with further promoting the luminal deposition of platelet-derived regulated on activation normal T cell expressed and secreted/chemokine (C-C motif) ligand 5 and expression of monocyte chemoattractant protein-1 and vascular cell adhesion molecule 1 in wire-injured carotid arteries. Remarkably, all these inflammatory actions by activated platelets were abrogated by lack of CD40 on injected platelets. Moreover, injection of wild-type platelets inhibited endothelial recovery in wire-injured carotid arteries, but this effect was also abrogated by lack of CD40 on injected platelets. Results suggest that platelet CD40 plays a pivotal role in neointima formation after arterial injury and might represent an attractive target to prevent restenosis after vascular interventions.


Asunto(s)
Plaquetas/metabolismo , Antígenos CD40/metabolismo , Traumatismos de las Arterias Carótidas/metabolismo , Leucocitos/metabolismo , Neointima/metabolismo , Animales , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Aterosclerosis/metabolismo , Antígenos CD40/genética , Inflamación/genética , Inflamación/metabolismo , Ratones , Ratones Noqueados
7.
Glob Chang Biol ; 25(3): 938-953, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30552830

RESUMEN

It is critical to accurately estimate carbon (C) turnover time as it dominates the uncertainty in ecosystem C sinks and their response to future climate change. In the absence of direct observations of ecosystem C losses, C turnover times are commonly estimated under the steady state assumption (SSA), which has been applied across a large range of temporal and spatial scales including many at which the validity of the assumption is likely to be violated. However, the errors associated with improperly applying SSA to estimate C turnover time and its covariance with climate as well as ecosystem C sequestrations have yet to be fully quantified. Here, we developed a novel model-data fusion framework and systematically analyzed the SSA-induced biases using time-series data collected from 10 permanent forest plots in the eastern China monsoon region. The results showed that (a) the SSA significantly underestimated mean turnover times (MTTs) by 29%, thereby leading to a 4.83-fold underestimation of the net ecosystem productivity (NEP) in these forest ecosystems, a major C sink globally; (b) the SSA-induced bias in MTT and NEP correlates negatively with forest age, which provides a significant caveat for applying the SSA to young-aged ecosystems; and (c) the sensitivity of MTT to temperature and precipitation was 22% and 42% lower, respectively, under the SSA. Thus, under the expected climate change, spatiotemporal changes in MTT are likely to be underestimated, thereby resulting in large errors in the variability of predicted global NEP. With the development of observation technology and the accumulation of spatiotemporal data, we suggest estimating MTTs at the disequilibrium state via long-term data assimilation, thereby effectively reducing the uncertainty in ecosystem C sequestration estimations and providing a better understanding of regional or global C cycle dynamics and C-climate feedback.


Asunto(s)
Ciclo del Carbono , Secuestro de Carbono , Cambio Climático , Ecosistema , Monitoreo del Ambiente , Carbono/análisis , China , Bosques , Modelos Teóricos , Lluvia , Temperatura
8.
Cephalalgia ; 37(4): 336-347, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27152016

RESUMEN

Aim We aimed to identify clinical characteristics and risk factors associated with onset of high-altitude headache (HAH) after acute exposure at 3700 m. Method In two hours, 163 individuals ascended by plane to 3700 m. Demographic information, physiological and psychological measurements, cognitive function, physical work capacity tests and profile of mood states within one week prior to the departure and within 24 hours after arrival were examined. Results HAH patients featured significantly higher vertebral artery diastolic velocity (Vd), heart rate (HR) and pulmonary artery diameter. HAH was also associated with a more negative mood state, including scores for tension anxiety, depression, hostility, fatigue and confusion, as well as lower vigor (all p values <0.05). Furthermore, negative emotions were positively related to HAH severity. HAH slightly decreased cognitive functioning. HR, Vd, lack of vigor, confusion and self-reported anxiety (all p values <0.05) were independent risk factors for HAH. We have identified three independent baseline predictors for HAH including internal diameter of the left ventricle (LVD), Athens Insomnia Scale (AIS) and confusion score. Conclusions Higher HR, Vd, confusion and self-reported anxiety and insufficient vigor were independent risk factors for HAH. Furthermore, higher baseline LVD, AIS and confusion score are independent predictors of HAH.


Asunto(s)
Mal de Altura/fisiopatología , Mal de Altura/psicología , Cefalea/etiología , Hemodinámica/fisiología , Adolescente , Pueblo Asiatico , Ventrículos Cardíacos/anatomía & histología , Humanos , Masculino , Factores de Riesgo
9.
Analyst ; 142(22): 4257-4264, 2017 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-28835953

RESUMEN

Rapid screening of active compounds plays a crucial role in the research and application of complex natural medicines. Herein, a new method of simultaneous label-free multi-drug screening based on a selective aptamer-carboxyfluorescein/graphene oxide energy transfer optical sensor combined with microfluidic chip electrophoretic separation is reported. In this study, seven traditional Chinese medicinal monomers were chosen as targets for the screening of G-quadruplex ligands. The screening results of the G-quadruplex active ligands, including daidzein, berberine hydrochloride, jatrorrhizine hydrochloride, and fangchinoline, and non-active ligands, including geniposide and oxymatrine, were consistent with those reported in literature. Moreover, one new potential G4DNA active drug, jujuboside A, was identified. Molecular simulation of the interaction between G4DNA and drugs was also carried out using HyperChem and AutoDock to verify the results of the experimental screening. It further demonstrated the reliability of our strategy. This novel separation and concentration based multi-sensing strategy provides a simple, rapid, and sensitive tool for simultaneous multi-drug screening, which is very meaningful for drug screening and bio-interaction analysis.


Asunto(s)
Técnicas Biosensibles , Evaluación Preclínica de Medicamentos/métodos , Electroforesis , G-Cuádruplex , Microfluídica , Aptámeros de Nucleótidos , Transferencia de Energía , Fluoresceínas , Grafito , Ligandos , Reproducibilidad de los Resultados , Saponinas
10.
J Nanosci Nanotechnol ; 16(4): 3628-31, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27451678

RESUMEN

This paper described the controlled synthesis and release properties of a new kind of multifunctional drug-release system which was prepared by encapsulation of zirconium bis-(monohydrogen orthophosphate) monohydrate (α-ZrP) with chitosan (CHI). As obtained the α-ZrP@CHI nanocomposites were found to possess the structural features of both α-ZrP and CHI. The release properties of the α-ZrP@CHI nanocomposites were evaluated using Gentamicin sulfate as the model drug. And α-ZrP@CHI composites showed a prolonged drug release time compared with α-ZrP, which can be attributed to the unique lamellar structure and the encapsulation with CHI. The controlled synthesis of α-ZrP@CHI nanocomposite thus provided a new opportunity for future development of delivery vehicles.


Asunto(s)
Quitosano/química , Preparaciones de Acción Retardada/síntesis química , Gentamicinas/química , Nanocápsulas/química , Nanocápsulas/ultraestructura , Circonio/química , Antibacterianos/administración & dosificación , Antibacterianos/química , Difusión , Gentamicinas/administración & dosificación , Ensayo de Materiales
11.
J Environ Sci (China) ; 46: 220-8, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27521954

RESUMEN

Lakes are an important component of terrestrial carbon cycling. As the trend of eutrophication in many lakes continues, the mechanisms of organic carbon (OC) burial remain unclear. This paper aims to understand the distribution of OC and the effect of trophic level changes on OC burial in Chaohu Lake, a shallow eutrophic lake located in the lower reaches of the Yangtze River, SE China. Two hundred and one surface sediment samples (0-20cm) and 53 subsurface samples (150-200cm) from the lake were collected. The OC accumulation rates (OCARs) are relatively low, with an average of 10.01g/m(2)/year in the surface sediments. The spatial distribution of the OCARs is similar to that of allochthonous OC. The difference in total phosphate (TP) content between the surface and subsurface sediments (ΔTP) is significantly correlated with the autochthonous OC, suggesting that TP loading is a critical limiting nutrient for the lake's primary productivity. It is concluded that allochthonous OC is the dominant source of total OC in surface sediments compared to autochthonous OC. The primary productivity of Lake Chaohu increased due to increasing nutrient loading. However, the autochthonous OC contributed 11% of the total OC in the surface sediments. This could be ascribed to strong mineralization in the water column or surface sediments.


Asunto(s)
Ciclo del Carbono , Secuestro de Carbono , Monitoreo del Ambiente , Cadena Alimentaria , Lagos/química , Contaminantes Químicos del Agua/análisis , Carbono/análisis , China , Ecosistema , Eutrofización , Nitrógeno/análisis , Fosfatos , Fósforo/análisis
12.
J Environ Sci (China) ; 42: 71-78, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27090696

RESUMEN

Changes in metal concentrations in the litter of Potamogeton crispus were monitored during a consecutive 40-day in situ decomposition experiment using the litterbag method. The accumulation index was calculated and used to indicate the changes in the metals in litter. The results showed that the concentrations of Al, Cd, Cr, Fe, Mn, and Pb in litter increased significantly during the decomposition, while Cu and Zn concentrations decreased dramatically. Significant positive correlations were found between the concentrations of Al, Cr, Fe, and Mn and between Cu and Zn. Moreover, Cu and Zn both negatively correlated with Al and Fe. The remaining dry mass was negatively correlated with Al and Fe concentrations but positively correlated with Cu and Zn concentrations. Generally the accumulation index values of metals other than Al were less than one, indicating that the litter of P. crispus acted as a source of metals to the surrounding water body. Al was the only metal that showed continuous net accumulation in litter. The net accumulation of Fe and Mn in litter during the last 10 days of the experiment may indicate the precipitation of Fe- and Mn-oxides. It was estimated that 160 g/m(2) (dry weight) P. crispus was decomposed in 40 days. This was equivalent to releasing the following amounts of metals: 0.01 mg Cd, 0.03 mg Cr, 0.71 mg Cu, 0.55 mg Mn, 0.02 mg Pb and 13.8 mg Zn into surrounding water, and accumulating 149 mg Al and 11 mg Fe, in a 1m(2) area.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/análisis , Potamogetonaceae/química , Biodegradación Ambiental , Sedimentos Geológicos/química , Lagos/química , Contaminantes Químicos del Agua/análisis
13.
J Headache Pain ; 16: 527, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25968101

RESUMEN

BACKGROUND: This study aimed to identify the systemic and cerebral hemodynamic characteristics and their roles in high-altitude headache (HAH) among young Chinese men following acute exposure. METHODS: The subjects (n = 385) were recruited in June and July of 2012. They completed case report form questionnaires, as well as heart rate (HR), blood pressure, echocardiogram and transcranial Doppler examinations at 3700 m following a two-hour plane flight. A subgroup of 129 participants was examined at two altitudes (500 and 3700 m). RESULTS: HAH was characterized by increased HR and cardiac output (CO) and lower saturation pulse oxygen (SpO(2)) (all p < 0.05). The change in tricuspid regurgitation was also different between the HAH positive (HAH+) and HAH negative (HAH-) subjects. Furthermore, the HAH+ subjects exhibited faster mean (V(m)), systolic (V(s)) and diastolic (V(d)) velocities in the basilar artery (BA; all p < 0.05) and a faster V(d) ( 25.96 ± 4.97 cm/s vs. 24.76 ± 4.76 cm/s, p = 0.045) in the left vertebral artery (VA). The bilateral VA asymmetry was also significantly different between the two groups. The pulsatility index (PI) and resistance index (RI) of left VA were lower in the HAH subjects (p < 0.05) and were negatively correlated with HAH (p < 0.05). Baseline CO and Vm in left VA (or right MCA in different regressions) were independent predictors for HAH, whereas CO/HR and ΔV(d) (V(d) difference between bilateral VAs) were independent risk factors for HAH at 3700 m. CONCLUSIONS: HAH was characterized, in part, by increased systemic hemodynamics and posterior cerebral circulation, which was reflected by the BA and left VA velocities, and lower arterial resistance and compliance. Furthermore, baseline CO and V(m) in left VA or right MCA at sea level were independent predictors for HAH, whilst bilateral VA asymmetry may contribute to the development of HAH at high altitude.


Asunto(s)
Mal de Altura/fisiopatología , Circulación Cerebrovascular/fisiología , Cefalea/fisiopatología , Hemodinámica/fisiología , Adolescente , Adulto , Altitud , Mal de Altura/complicaciones , Presión Sanguínea/fisiología , Cefalea/etiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Encuestas y Cuestionarios , Adulto Joven
14.
Analyst ; 139(11): 2890-5, 2014 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-24755615

RESUMEN

A new type of high-throughput and parallel optical sensing platform with a single-color probe based on microfluidic chip electrophoresis combined with aptamer-carboxyfluorescein/graphene oxide energy transfer is reported here. Label-free protein multi-targets were detected, even in challenging complex samples without any pre-treatment.


Asunto(s)
Electroforesis por Microchip/métodos , Grafito/química , Microfluídica/instrumentación , Proteínas/análisis , Aptámeros de Nucleótidos/genética , Espectrometría de Fluorescencia , Trombina/genética
15.
J Sep Sci ; 37(21): 3174-80, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25204739

RESUMEN

An immobilized pH gradient was directly constructed on the inner wall of a microfluidic chip channel by photoimmobilizing focused carrier ampholytes onto the wall. A mixture of carbonic anhydrase, myoglobin, and trypsin inhibitor was successfully isoelectric-focused and separated with good linearity between the pI values of proteins and the location of the focused bands. Furthermore, coating methods for the resistance of protein nonselective adsorption and simultaneously for pH gradient photocoupling were screened. The PEG-silane coating method was found to be better than the cross-linked polyacrylamide coating and aminosilane modification methods. Finally, based on the open tubular column mode of carrier ampholytes' immobilization and effective antiadsorption coating, the immobilized pH gradient was reused and the chip was recycled for the first time. By virtue of its remarkable features including simplicity, convenience, high efficiency of protein enrichment and separation, and potential for coupling site-selective IEF with other analytical or separation techniques, this novel method promises to be useful in several applications related with zwitterionic biomolecules.


Asunto(s)
Focalización Isoeléctrica/métodos , Técnicas Analíticas Microfluídicas/métodos , Proteínas/química , Concentración de Iones de Hidrógeno , Focalización Isoeléctrica/instrumentación
16.
J Nanosci Nanotechnol ; 14(5): 3380-6, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24734555

RESUMEN

A series of rare-earth ions (Er3+ and Yb3+) Co-doped CaF2 upconversion luminescent nanomaterials have been successfully prepared via a facile hydrothermal method using pluronic p123 (p123), pluronic F127 (F127) and sodium citrate as surfactants at 180 degrees C with different reaction time. The crystallographic phase, size and morphology can be controlled by simply tuning the reaction parameters such as the types of surfactants and the reaction time. It is found that reaction time and surfactant play a key role in forming the nanocrystals with different morphologies. X-ray diffraction, field-emission scanning electron microscopy FE-SEM, and photoluminescence spectra were used to characterize the structure, morphology and upconversion luminescence properties of CaF2:Er3+/Yb3+ upconversion nanomaterials, respectively. The experimental results indicate that three monodispersive and highly uniform CaF2:Er3+/Yb3+ nanocrystals with mean size of 200 nm, 3 um, and 700 nm have cubic and sphere shapes, respectively. While the possible mechanisms of upconversion luminescence are analyzed by the diagram of proposed energy transfer mechanisms, the schematic energy level diagrams showing typical upconversion processes for Er3+ also reveals that the as-synthesized CaF2:Er3+/Yb3 nanomaterials may be in the cubic structure with space group Fm-3m, in which Ln3+ cations occupy crystal lattice positions with lower point symmetry, leading to a high upconversion efficiency under the excitation of a 980 nm diode laser.

17.
Eur J Appl Physiol ; 114(10): 2193-200, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24996805

RESUMEN

PURPOSE: We aimed at identifying the cerebral hemodynamic characteristics of acute mountain sickness (AMS). METHODS: Transcranial Doppler (TCD) sonography examinations were performed between 18 and 24 h after arrival at 3,700 m via plane from 500 m (n = 454). A subgroup of 151 subjects received TCD examinations at both altitudes. RESULTS: The velocities of the middle cerebral artery, vertebral artery (VA) and basilar artery (BA) increased while the pulsatility indexes (PIs) and resistance indexes (RIs) decreased significantly (all p < 0.05). Velocities of BA were higher in AMS (AMS+) individuals when compared with non-AMS (AMS-) subjects (systolic velocity: 66 ± 12 vs. 69 ± 15 cm/s, diastolic velocity: 29 ± 7 vs. 31 ± 8 cm/s and mean velocity, 42 ± 9 vs. 44 ± 10 cm/s). AMS was characterized by higher diastolic velocity [V d_VA (26 ± 4 vs. 25 ± 4, p = 0.013)] with lower PI and RI (both p = 0.004) in VA. Furthermore, the asymmetry index (AI) of VAs was significantly lower in the AMS + group [-5.7 % (21.0 %) vs. -2.5 % (17.8 %), p = 0.016]. The AMS score was closely correlated with the hemodynamic parameters of BA and the V d_VA, PI, RI and AI of VA. CONCLUSION: AMS is associated with alterations in cerebral hemodynamics in the posterior circulation rather than the anterior one, and is characterized by higher blood velocity with lower resistance. In addition, the asymmetry of VAs may be involved in AMS.


Asunto(s)
Mal de Altura/fisiopatología , Circulación Cerebrovascular , Hemodinámica , Adolescente , Adulto , Factores de Edad , Altitud , Estudios de Casos y Controles , Humanos , Masculino , Persona de Mediana Edad
18.
Anal Methods ; 16(20): 3249-3255, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38726641

RESUMEN

The past and present scenario of COVID-19 has revealed the necessity of simple point-of-care tests. When combined with the great advantages of amplification, lateral flow assay nucleic acid analysis represents a more sensitive molecular diagnostic technique compared to universal protein analysis. Room temperature operation, an enzyme-free nature, and in situ elongation make hybrid chain reaction amplification (HCR) a good candidate for amplified combined lateral flow assays (LFAs). Since dual modes of detection can not only satisfy different application scenarios, but also reduce the false-negative rate, in this paper, visual and fluorescent detection based on labelling with colloidal gold nanoparticles and fluorescence labelling were incorporated into a HCR integrated with a LFA. The detection assay was finished in 30 minutes. The linear relationship between the signal and the concentration of the characteristic segment in the COVID-19 ORF gene was demonstrated. The obtained detection limits of as low as 10 fM (6.02 × 103 copies per mL) and 1 fM (6.02 × 102 copies per mL), respectively, were comparable with those in the literature. The multi-site HCR amplification integrated with LFA of a 1053 bp nucleic acid chain was also preliminarily studied, and tri-site amplification was found to exhibit higher signal intensity than single-site amplification. This study provides a promising strategy for simple, sensitive, and wide-ranging detection of pathogenic bacteria.


Asunto(s)
COVID-19 , Técnicas de Amplificación de Ácido Nucleico , SARS-CoV-2 , SARS-CoV-2/genética , Humanos , COVID-19/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/métodos , Límite de Detección , Técnicas de Diagnóstico Molecular/métodos , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba de Ácido Nucleico para COVID-19/instrumentación , Nanopartículas del Metal/química , ARN Viral/análisis , ARN Viral/genética
20.
Int J Cardiol ; 401: 131817, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38307422

RESUMEN

BACKGROUND: High-altitude exposure changes the electrical conduction of the heart. However, reports on electrocardiogram (ECG) characteristics and potent prophylactic agents during high-altitude acclimatization and de-acclimatization are inadequate. This study aimed to investigate the effects of ubiquinol on electrophysiology after high-altitude hypoxia and reoxygenation. METHODS: The study was a prospective, randomized, double-blind, placebo-controlled trial. Forty-one participants were randomly divided into two groups receiving ubiquinol 200 mg daily or placebo orally 14 days before flying to high altitude (3900 m) until the end of the study. Cardiopulmonary exercise testing was performed at baseline (300 m), on the third day after reaching high altitude, and on the seventh day after returning to baseline. RESULTS: Acute high-altitude exposure prolonged resting ventricular repolarization, represented by increased corrected QT interval (455.9 ± 23.4 vs. 427.1 ± 19.1 ms, P < 0.001) and corrected Tpeak-Tend interval (155.5 ± 27.4 vs. 125.3 ± 21.1 ms, P < 0.001), which recovered after returning to low altitude. Ubiquinol supplementation shortened the hypoxia-induced extended Tpeak-Tend interval (-7.7 ms, [95% confidence interval (CI), -13.8 to -1.6], P = 0.014), Tpeak-Tend /QT interval (-0.014 [95% CI, -0.027 to -0.002], P = 0.028), and reserved maximal heart rate (11.9 bpm [95% CI, 3.2 to 20.6], P = 0.013) during exercise at high altitude. Furthermore, the decreased resting amplitude of the ST-segment in the V3 lead was correlated with decreased peak oxygen pulse (R = 0.713, P < 0.001) and maximum oxygen consumption (R = 0.595, P < 0.001). CONCLUSIONS: Our results illustrated the electrophysiology changes during high-altitude acclimatization and de-acclimatization. Similarly, ubiquinol supplementation shortened the prolonged Tpeak-Tend interval and reserved maximal heart rate during exercise at high altitude. REGISTRATION: URL: www.chictr.org.cn; Unique identifier: ChiCTR2200059900.


Asunto(s)
Altitud , Capacidad Cardiovascular , Ubiquinona/análogos & derivados , Humanos , Estudios Prospectivos , Hipoxia , Aclimatación , Electrofisiología
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