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1.
Environ Sci Technol ; 58(11): 5117-5128, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38440993

RESUMEN

Vulcanization accelerators (VAs) serve as crucial additives in synthetic rubber on a global scale. Despite their widespread use, the environmental presence, distribution, and associated exposure risks of VAs remain poorly understood. This study compiled a target list and conducted a screening for eight classes encompassing 42 VAs in diverse urban dust samples from South China. A total of 40 of the 42 target VAs were detectable across all four studied regions, among which 30 were identified for the first time in the environment. Among the eight structure-classified VA classes, xanthates exhibited the highest concentrations (median: 3810-81,300 ng/g), followed by thiazoles, guanidines, sulfenamides, dithiocarbamates, thiurams, thioureas, and others. The median total concentrations of all target VAs (∑VAs) were determined to be 5060 ng/g in road dust, 5730 ng/g in parking lot dust, 29,200 ng/g in vehicle repair plant dust, and 84,300 ng/g in household dust, indicating the widespread presence of numerous rubber-derived VAs in various urban environments. This study marked the first systematic effort to identify a wide range of emerging rubber-derived VAs prevalent in urban environments. The findings call for increased attention to these widely utilized but less well-evaluated chemicals in future research and environmental management efforts.


Asunto(s)
Polvo , Insecticidas , Polvo/análisis , Exposición a Riesgos Ambientales/análisis , Tiram , Tiazoles , China , Monitoreo del Ambiente
2.
Nano Lett ; 23(15): 7037-7045, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37463459

RESUMEN

The chemical mechanism (CM) of surface-enhanced Raman scattering (SERS) has been recognized as a decent approach to mildly amplify Raman scattering. However, the insufficient charge transfer (CT) between the SERS substrate and molecules always results in unsatisfying Raman enhancement, exerting a substantial restriction for CM-based SERS. In principle, CT is dominated by the coupling between the energy levels of a semiconductor-molecule system and the laser wavelength, whereas precise tuning of the energy levels is intrinsically difficult. Herein, two-dimensional transition-metal dichalcogenide alloys, whose energy levels can be precisely and continuously tuned over a wide range by simply adjusting their compositions, are investigated. The alloys enable on-demand construction of the CT resonance channels to cater to the requirements of a specific target molecule in SERS. The SERS signals are highly reproducible, and a clear view of the SERS dependences on the energy levels is revealed for different CT resonance terms.

3.
Prehosp Emerg Care ; 27(5): 669-686, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35579544

RESUMEN

INTRODUCTION: There is limited research available on safe medication management practices in emergency medical services (EMS) practice, with most evidence-based medication safety guidelines based on research in nursing, operating theater and pharmacy settings. Prevention of errors requires recognition of contributing factors across the spectrum from the organizational level to procedural elements and patient characteristics. Evidence is inconsistent regarding the incidence of medication errors and multiple sources also state that errors are under-reported, making the true magnitude of the problem difficult to quantify. Definitions of error also vary, with the specific context of medication errors in prehospital practice yet to be established. The objective of this review is to identify the factors influencing the occurrence of medication errors by EMS personnel in the prehospital environment. METHODS AND ANALYSIS: The review included both qualitative and quantitative research involving interventions or phenomena related to medication safety or medication error by EMS personnel in the prehospital environment. A search of multiple databases was conducted to identify studies meeting these inclusion criteria. All studies selected were assessed for methodological quality; however, this was not used as a basis for exclusion. Each stage of study selection, appraisal and data extraction was conducted by two independent reviewers, with a third reviewer deciding any unresolved conflicts. The review follows a convergent integrated approach, conducting a single qualitative synthesis of qualitative and "qualitized" quantitative data. RESULTS: Fifty-six articles were included in the review, with case reports and qualitative studies being the most frequent study types. Qualitative analysis revealed seven major themes: organizational factors (with reporting as a sub-theme), equipment/medications, environmental factors, procedure-related factors, communication, patient-related factors (with pediatrics as a sub-theme) and cognitive factors. Both contributing factors and protective factors were identified. DISCUSSION: The body of evidence regarding medication errors is heterogenous and limited in both quantity and quality. Multiple factors influence medication error occurrence; knowledge of these is necessary to mitigate the risk of errors. Medication error incidence is difficult to quantify due to inconsistent measure, definitions and contexts of research conducted to date. Further research is required to quantify the prevalence of identified factors in specific practice settings.


Asunto(s)
Servicios Médicos de Urgencia , Auxiliares de Urgencia , Humanos , Niño , Paramédico , Errores de Medicación/prevención & control , Investigación Cualitativa
4.
BMC Musculoskelet Disord ; 24(1): 419, 2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37231389

RESUMEN

BACKGROUND: Anteroposterior (AP) and lateral fluoroscopies are often used to evaluate the intraoperative location and angulation of the trajectory in percutaneous endoscopic transforaminal lumbar discectomy (PETLD). Although the location of the trajectory shown in fluoroscopy is absolutely accurate, the angulation is not always reliable. This study aimed to evaluate the accuracy of the angle shown in the AP and lateral fluoroscopic views. METHODS: A technical study was performed to assess the angulation errors of PETLD trajectories shown in AP and lateral fluoroscopic views. After reconstructing a lumbar CT image, a virtual trajectory was placed into the intervertebral foramen with gradient-changing coronal angulations of the cephalad angle plane (CACAP). For each angulation, virtual AP and lateral fluoroscopies were taken, and the cephalad angles (CA) of the trajectory shown in the AP and lateral fluoroscopic views, which indicated the coronal CA and the sagittal CA, respectively, were measured. The angular relationships among the real CA, CACAP, coronal CA, and sagittal CA were further demonstrated with formulae. RESULTS: In PETLD, the coronal CA is approximately equal to the real CA, with a small angle difference and percentage error, whereas the sagittal CA shows a rather large angle difference and percentage error. CONCLUSION: The AP view is more reliable than the lateral view in determining the CA of the PETLD trajectory.


Asunto(s)
Discectomía Percutánea , Desplazamiento del Disco Intervertebral , Humanos , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/cirugía , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Endoscopía/métodos , Fluoroscopía , Discectomía Percutánea/métodos
5.
Acta Neurochir (Wien) ; 165(5): 1155-1160, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36534186

RESUMEN

PURPOSE: To elucidate the anatomic relationship between the internal carotid artery (ICA) and the bony structures of the craniovertebral junction among "sandwich" atlantoaxial dislocation (AAD) patients, and to analyze the risks of injury during surgical procedures. METHODS: The distance from the medial wall of ICA to the midsagittal plane (D1), the shortest distance between the ICA wall and the anterior cortex of the lateral mass of atlas (LMA) (D2) on the most caudal and cranial levels of LMA and the angle (A) between the sagittal plane passing through the screw entry point of C1 lateral mass(C1LM) screw and the medial tangent line of the vessel passing through the entry point were measured. Besides, the location of ICA in front of the atlantoaxial vertebra was divided into 4 categories (Z1-Z4). RESULTS: There was a statistically difference between the male and female patients regarding D1, and the difference between D2 at level a and level b as well as angle A between the left and right sides were statistically different (p < 0.05). Ninety-two ICAs (57.5%) were anteriorly located in Z3, 50 (31.3%) were located in Z4, 17 were located in Z2, and only one ICA was located in Z1 in all 80 patients. CONCLUSIONS: In "sandwich" AAD patients, particular attention should be paid to excessively medialized ICA to avoid ICA injury during trans-oral procedures, and the risk of injuring the ICA with more cranially and medially angulated C1LM screw placement was relatively less during posterior fixation procedures. A novel classification of ICA location was used to describe the relationship between ICA and LMA.


Asunto(s)
Articulación Atlantoaxoidea , Traumatismos de las Arterias Carótidas , Luxaciones Articulares , Traumatismos del Cuello , Fusión Vertebral , Humanos , Masculino , Femenino , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/cirugía , Fusión Vertebral/métodos , Vértebras Cervicales/cirugía , Tornillos Óseos , Luxaciones Articulares/diagnóstico por imagen , Luxaciones Articulares/cirugía , Articulación Atlantoaxoidea/diagnóstico por imagen , Articulación Atlantoaxoidea/cirugía
6.
Psychol Health Med ; 28(8): 2156-2168, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35477332

RESUMEN

A range of studies have shown that prenatal maternal stress (PNMS) exposure is associated with offspring autistic-like behaviors, however the potential pathways remain unexplored. This study aimed to evaluate the mediating role of parent-child interactions in early life in the association between PNMS exposure and preschoolers' autistic-like behaviors. Data from 65,928 child-parent dyads were obtained via a primary caregiver-reported questionnaire administered as part of the Longhua Child Cohort Study. To strengthen confidence in the reliability of the results, the analyses were initially conducted on a random selection of 70% of the total sample, and then validated on the remaining 30% of the sample. Analysis of covariance and multiple linear models were employed to estimate the associations between PNMS exposure, parent-child interactions in early life, and children's autistic-like behaviors. The results showed that PNMS exposure was positively associated with the presence of autistic-like behaviors at preschool age. The total indirect effect of the frequency of positive parent-child interactions in early life accounted for 9.69% or 8.99% of the variance of the association. Our findings indicate that parent-child interactions in early life might function as potential mediators of the association between PNMS and the increased risk of offspring autistic-like behaviors.

7.
Eur Spine J ; 31(2): 267-274, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35075515

RESUMEN

PURPOSE: This study aimed to evaluate the effect of postoperative reciprocal progression of Lordosis tilt (LT), Lordosis distribution index (LDI) and occurrence of Proximal junctional kyphosis (PJK) following surgery for Degenerative lumbar scoliosis (DLS). METHODS: A total of 122 consecutive patients with ADS were treated with correction of deformity and followed up for a minimum of 2 years. Spinopelvic parameters were measured preoperatively, postoperatively, and at the latest follow-up. The Japanese Orthopaedic Association score, Oswestry Disability Index, and visual analog scale scores were measured at the latest follow-up. Associations between LT, LDI, and PJK were analyzed using receiver operating characteristic analyses. RESULTS: The prevalence of PJK in the present study was 24.6%. The outcomes of patients with PJK were significantly worse than those of patients without PJK. Postoperative reciprocal progression in LT and LDI with lumbar lordosis restorative surgery was observed. Preoperative risk factors for PJK were older age, larger LT, and larger Cobb angle of the curves. Postoperative risk factors for PJK included postoperative LT and postoperative Cobb angle of the curves, which were smaller than those preoperatively. We found a strong correlation between postoperative LT and Cobb angle of the curves resulting in PJK. Patients with LT < - 8° were at a higher risk of PJK. CONCLUSIONS: LT can be used to predict the occurrence of PJK in patients undergoing surgery for DLS. Appropriate postoperative LT is crucial for preventing the progression of PJK.


Asunto(s)
Cifosis , Lordosis , Escoliosis , Fusión Vertebral , Adulto , Animales , Humanos , Cifosis/diagnóstico por imagen , Cifosis/epidemiología , Cifosis/etiología , Lordosis/diagnóstico por imagen , Lordosis/epidemiología , Lordosis/cirugía , Complicaciones Posoperatorias/epidemiología , Periodo Posoperatorio , Estudios Retrospectivos , Factores de Riesgo , Escoliosis/complicaciones , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Fusión Vertebral/efectos adversos
8.
Public Health ; 206: 20-28, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35313129

RESUMEN

OBJECTIVES: This study aimed to explore the association of visual, hearing, or dual sensory impairment with healthcare use and costs. STUDY DESIGN: This is a cohort study. METHODS: These research data were from the China Health and Retirement Longitudinal Study spanning 2011-2018 and included 8982 community-dwelling middle-aged and older adults (aged ≥45 years at baseline). Sensory impairment was measured according to self-reported assessment of visual and hearing functions, and healthcare use and costs were ascertained via self-report. The associations of sensory impairment with healthcare use and costs were estimated using the mixed-effects regression models. RESULTS: Of the 8982 respondents, 4346 (48.39%) were females and their mean (standard deviation) age at baseline was 57.03 (8.26) years. Individuals with hearing impairment (HI) only, visual impairment (VI) only, and dual sensory impairment (DSI) were all at significantly higher risks of healthcare use and catastrophic health expenditure than those without sensory impairment (all P < 0.05), except that VI only non-significantly prolonged inpatient days. Compared with no impairment, DSI was associated with increases in outpatient (ß = 50.67, 95% confidence interval [CI] = 17.47-83.86) and inpatient out-of-pocket costs (ß = 40.35, 95% CI = 5.94-74.76), while VI only or HI only did not show significant effects. Further stratification analyses indicated that the associations between sensory impairment and outpatient use were more pronounced among males than among females but that age group did not moderate the associations with any healthcare outcomes. CONCLUSIONS: HI and VI were independently and together associated with higher risks of healthcare use and catastrophic health expenditure. Dual sensory impairment was the only category consistently associated with increased outpatient and inpatient costs.


Asunto(s)
Pérdida Auditiva , Trastornos de la Visión , Anciano , China/epidemiología , Estudios de Cohortes , Atención a la Salud , Femenino , Pérdida Auditiva/epidemiología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Trastornos de la Visión/epidemiología
9.
BMC Med Educ ; 22(1): 219, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35354454

RESUMEN

BACKGROUND: Overseas study trips can enhance healthcare students' intercultural communication competence. An opportunity to immerse in the new culture enables them to develop their ability to offer services to people from different countries. However, the role that open-mindedness (i.e., a personality trait) can play in this process has not been explored. METHODS: The present study adopted a mixed-method design to identify how open-mindedness trait affected this overseas learning process. Thirty-two undergraduate healthcare students in Australia took part in the study. Questionnaires, which measured socio-demographic information, intercultural communication competence and open-mindedness trait were administered to the participants before and after their overseas trip. Half of the participants (n = 16) were interviewed after the overseas trip. RESULTS: The correlational analysis showed that the open-mindedness trait was correlated with cultural skills, a component of intercultural communication competence, but not significant with the other three components. Three themes emerging from the qualitative data indicated that the open-mindedness trait affected students' cultural exposure. This trait enabled participants to be actively involved in the immersion in the local culture. They were willing to learn from peer fellows, and keen to embrace novel challenges. CONCLUSION: It is concluded that open-mindedness trait is vital for increasing cultural immersion, and hence promote intercultural communication skills.


Asunto(s)
Competencia Cultural , Atención a la Salud , Australia , Comunicación , Humanos , Encuestas y Cuestionarios
10.
Br J Clin Pharmacol ; 87(4): 2098-2110, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33098714

RESUMEN

AIMS: Ningetinib is a tyrosine kinase inhibitor for the treatment of non-small cell lung cancer (NSCLC). The present study aims to investigate the drug interaction of ningetinib and gefitinib and the mechanism of high plasma exposure of N-demethylated ningetinib (M1) in NSCLC patients. METHODS: Patients with NSCLC were recruited. Metabolism and transport assays were performed using in vitro models. Deuterated M1 was used to study the effects of ningetinib and gefitinib on M1 efflux in Institute of Cancer Research (ICR) mice. RESULTS: Upon co-administration of ningetinib with gefitinib, the plasma exposure of M1 was reduced by 80%, whereas that of ningetinib was not affected. In vitro experiments indicated that CYP1A1 was primarily responsible for M1 formation. Gefitinib was demonstrated to be a strong inhibitor of CYP1A1 with Ki value of 0.095 µM. M1 was identified as a substrate of efflux transporters P-gp and BCRP, while ningetinib and gefitinib were demonstrated to be their inhibitors, which was consistent with the results in mice. However, the inhibitory effect of gefitinib on efflux in vivo was negligible in the presence of ningetinib. CONCLUSION: The high plasma exposure of M1 in patients was attributed to the inhibition of M1 efflux by ningetinib and its low tissue affinity. When co-administered, gefitinib inhibited the formation of M1, but due to the low metabolic yield of M1 in vivo, the pharmacokinetics of ningetinib was not influenced. Inhibition of CYP1A1 may increase the concentration of ningetinib in target tissues, and the long-term safety and efficacy of ningetinib combined with gefitinib should be evaluated.


Asunto(s)
Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Citocromo P-450 CYP1A1 , Interacciones Farmacológicas , Gefitinib/farmacología , Gefitinib/uso terapéutico , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones , Proteínas de Neoplasias/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinazolinas/farmacología , Quinazolinas/uso terapéutico
11.
Nanotechnology ; 31(5): 055502, 2020 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-31627207

RESUMEN

As a powerful analytical tool of molecular detection, surface-enhanced Raman spectroscopy (SERS) has attracted great attention in varied fields. However, it has seriously impeded the development of SERS that the preparation process is generally complicated and traditional substrates lack eco-friendliness, economy and flexibility. Herein, we fabricated the inkjet-printed paper-based semiconducting SERS substrates for the first time via an inexpensive office inkjet printer with representative two-dimensional MoO3-x nanosheets ink. Compared with conventional substrates, these paper-based semiconducting substrates not only could meet the requirements of simple and large-scale preparation, but also realize efficient sample collection by merely swabbing the surface. We obtained the detection limit concentration of rhodamine 6G as low as 10-7 M. Furthermore, these flexible paper-based substrates were successfully applied to detect crystal violet and malachite green on the fish surface by swabbing. With immense potentiality in practical applications, the inkjet-printed paper-based semiconducting SERS substrates are expected to open a new prospect for SERS.

12.
Acta Pharmacol Sin ; 41(6): 843-851, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31913347

RESUMEN

An increasing number of drugs are metabolized by aldehyde oxidase (AOX), but AOX-mediated drug interactions are seldom reported due to the lack of appropriate inhibitors and inducers. A recent study reported that nimesulide (NIM) could increase the liver injury risk of methotrexate. The latter was mainly metabolized by AOX to form hepatotoxic 7-hydroxymethotrexate (7-OH MTX). Thus, we speculated that NIM could induce AOX. In this study, we investigated the potential induction of AOX activity by NIM using methotrexate as the probe substrate. Treatment of primary human and rat hepatocytes with NIM (20 µM) for 24 h caused a 2.0- and 3.1-fold, respectively, increase in 7-OH MTX formation. Oral administration of NIM (100 mg·kg-1·d-1, for 5 days) to rats significantly increased the systematic exposure (6.5-fold), liver distribution (2.5-fold), and excretion (5.2-fold for urinary excretion and 2.1-fold for fecal excretion) of 7-OH MTX. The 7-OH MTX formation in liver cytosol from rats pretreated with 20, 50, and 100 mg·kg-1·d-1 NIM for 5 days increased by 1.9-, 3.2-, and 3.7-fold, respectively, compared with that of rats pretreated with the vehicle. We revealed that the elevation of AOX activity was accompanied by an increase in AOX1 protein levels but not the corresponding mRNA levels. Collectively, our results demonstrate for the first time that NIM can increase the AOX activity of humans and rats, and may raise concerns regarding the risk of drug interactions between NIM and AOX substrates in clinical practice.


Asunto(s)
Aldehído Oxidasa/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Sulfonamidas/farmacología , Administración Oral , Animales , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Relación Dosis-Respuesta a Droga , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Masculino , Metotrexato/administración & dosificación , Ratas , Ratas Wistar , Sulfonamidas/administración & dosificación
13.
J Invertebr Pathol ; 171: 107343, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32057749

RESUMEN

Gynaikothrips uzeli gall thrips are protected from insecticide exposure by their leaf gall habitat. A biocontrol strategy based on entomopathogenic fungi is an alternative approach for the control of G. uzeli. Higher temperatures can promote the reproduction and spread of pests; however, the impact of higher temperatures on biological control is unclear. We studied the immunocompetence of thrips from different latitudes and determined the effect of degree days on thrips immunity. We examined the potential impact of temperature on the biocontrol provided by entomopathogenic fungi. Beauveria bassiana pathogenicity against thrips increased with decreasing latitude, suggesting that immunity of thrips increased as latitude increased. The phenoloxidase activity of G. uzeli increased with increasing latitude but there was no significant change in hemocyte concentration. This indicated that the humoral immunity of thrips was significantly associated with degree days, and this was confirmed by transcriptome data. Transcriptome and RT-PCR results showed that the expression of key genes in eight toll pathways increased with increasing latitude. The relative expression of key genes in the Toll pathway of thrips and the activity of phenoloxidase decreased with increasing degree days that are characteristic of lower latitudes. These changes led to a decrease in humoral immunity. The immunity of G. uzeli against entomopathogenic fungi increased as degree days characteristic of lower latitudes decreased. Increased temperatures associated with lower latitude may therefore increase biocontrol efficacy. This study clarified immune level changes and molecular mechanisms of thrips under different degree days.


Asunto(s)
Beauveria/fisiología , Inmunocompetencia , Thysanoptera/inmunología , Distribución Animal , Animales , Control de Insectos , Control Biológico de Vectores , Thysanoptera/microbiología
14.
Nano Lett ; 19(11): 8132-8137, 2019 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-31556623

RESUMEN

Noncontact optical sensing plays an important role in various applications, for example, motion tracking, pilotless automobile, precision machining, and laser radars. A device with features of high resolution, fast response, and safe detection (operation wavelength at infrared (IR)) is highly desired in such applications. Here, a near IR position-sensitive detector constructed by graphene-Ge Schottky heterojunction has been demonstrated. The device shows high responsivity (minimum detectable power of ∼10 nW), excellent spatial resolution (<1 µm), fast response time (∼µs), and could operate in a wide spectral range (from visible to ∼1600 nm). Applications of precise angle (∼5 × 10-6 degree) and vibration frequency (up to 10 kHz) measurements, as well as the trajectory tracking of a high-speed infrared target (∼100 km/h), have been realized based on this device. This work therefore provides a promising route for a high-performance noncontact IR optical sensing system.

15.
Nanotechnology ; 30(18): 184001, 2019 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-30669129

RESUMEN

Rhenium disulfide (ReS2) is an interesting kind of transition metal dichalcogenide (TMD) because of its thickness-independent and suitable direct-bandgap structure, which could enable highly efficient solar-energy conversion efficiency. Here, we demonstrate an ultrasonic liquid exfoliation technique in combination with grinding to produce high quality ReS2 nanosheets (NSs) on a large scale. After combination with TiO2 nanoparticles, the co-catalytic performance of TiO2@ReS2 nanocomposites is investigated, which presents dramatically enhanced degradation activity of organic pigments under sunlight illumination in comparison with pure TiO2 nanoparticles. The underlying mechanism of enhanced photocatalytic activity can be attributed to improved separation efficiency of photogenerated electron-hole pairs in TiO2@ReS2 nanocomposites, which is confirmed by photoluminescence analysis and photoelectrochemical measurements. Our results demonstrate that the layered ReS2 NS is a promising two-dimensional supporting platform for photocatalysis and moreover it could also provide a new perspective on TMDs co-catalyst.

16.
Phys Chem Chem Phys ; 21(5): 2611-2618, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30657494

RESUMEN

Transition metal oxide semiconductors have been explored in surface-enhanced Raman scattering (SERS) active substrates, yet their detection sensitivity and enhancement effects are inferior. What's more, the reported fabrication technique ignored the effects of the electromagnetic mechanisms and was far from satisfactory for practical applications. Herein, we report on a convenient nanotechnique to fabricate large-area hexagon plum-blossom-like WO3-x nanoarrays based on aluminum nanobowl array substrates. Localized surface plasmon resonance can be increased via adjusting the time of tungsten magnetron sputtering with H2 annealing treatment. The introduction of a double-switch experiment demonstrates that localized surface plasmon-coupled photoinduced charge transfer can not only increase SERS enhancement comparable to similar silver nanostructures but also implement a low limit of detection below 10-9 M. A triple-switch experiment offers specific rules in the molecular detection of WO3-x semiconductors and important guidance for the fabrication of SERS-active semiconducting platforms.

17.
Eur J Dent Educ ; 23(3): 278-285, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30714273

RESUMEN

BACKGROUND: Massive Open Online Courses (MOOCs) have been often described as a major innovation Higher Education, but their application in the teaching of clinical disciplines is still very limited, while there is a lack of scientific evaluations in this domain. The aim of this study was to investigate learners' behaviours and correlate patterns of Self-Regulated Learning (SRL) with performance and achievement during a MOOC in Implant Dentistry. METHODS: The clickstream data of learners from the first run of the MOOC Implant dentistry by The University of Hong Kong were modelled and quantified based on Zimmerman's SRL model. The data were quantitatively analysed by means of k-means clustering for evidence of five SRL behavioural indicators of student activity. The clusters identified were then correlated with student engagement and learning performance. RESULTS: A total of 7608 individuals enrolled, 5014 engaged (active learners 65.90%), 1277 of them (25.47%) completed the course and 1232 purchased a certificate. Two major groups of learners emerged: Attentive (n = 1433) who were more likely to follow the prescribed pathway in the MOOC and Auditors (n = 3581) who accessed content selectively. There was significantly higher engagement, achievement and completion rates among Attentive than Auditors. Both groups included subcategories (Browser, Digger, Test-driven, Sampler, Persistent) which might reflect different SRL strategies. CONCLUSION: A MOOC in a clinical discipline can achieve high enrolment and completion rates as compared to current benchmarks. There appears to be a wide diversity of learning behaviours among learners, with two however dominant patterns. Learners with a linear learning pathway achieved significantly higher grades and completion rates than those who accessed content irregularly and selectively. Such differences however might be influenced by the demographic and professional background of the learner, as well as their motivation to attending the MOOC. Certain learning behaviours, in particular how learners access content in relation to assessments might be closer related to SRL.


Asunto(s)
Educación a Distancia , Odontología , Humanos , Aprendizaje
18.
Drug Metab Dispos ; 46(9): 1320-1328, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29980580

RESUMEN

Imrecoxib is a typical cyclooxygenase-2 inhibitor and the benzylic carbon motif is its major site of oxidative metabolism, producing a hydroxymethyl metabolite (M1) and a carboxylic acid metabolite (M2). The plasma exposure of M2 is four times higher than those of both M0 and M1 in humans. However, this metabolite is rarely formed in in vitro experiments. Therefore, this study aims to investigate the formation mechanism of M2 and to further elucidate the reason for the discrepancy between in vitro and in vivo metabolic data. By employing human hepatocytes, human liver microsomes (HLMs), human liver cytosols (HLCs), recombinant enzymes, and selective enzyme inhibitors, the metabolic map of imrecoxib was elaborated as follows: the parent drug was initially hydroxylated to form M1 in HLMs, mainly mediated by CYP3A4 and CYP2D6, and to subsequently form aldehyde imrecoxib (M-CHO) in HLMs and HLCs. The latter process is the rate-limiting step in generating the end-product M2. In further M-CHO metabolism, two opposite reactions (namely, rapid oxidation catalyzed by CYP3A4, CYP2D6, and cytosolic aldehyde oxidase to form M2 versus reduction to regenerate M1 mediated by NADPH-dependent reductases in HLMs and HLCs, such as cytochrome P450 reductase) led to marked underestimation of the M2 amount in static in vitro incubations. The findings provided a possible explanation for the difference between in vitro and in vivo metabolism of imrecoxib, suggesting that the effect of competitive reduction on the static oxidation metabolism in in vitro metabolic experiments should be considered.


Asunto(s)
Aldehídos/metabolismo , Inhibidores de la Ciclooxigenasa 2/metabolismo , Microsomas Hepáticos/metabolismo , Pirroles/metabolismo , Sulfuros/metabolismo , Administración Oral , Animales , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Citocromo P-450 CYP3A/metabolismo , Humanos , Masculino , Microsomas Hepáticos/efectos de los fármacos , Pirroles/administración & dosificación , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Sulfuros/administración & dosificación
19.
Nanotechnology ; 28(10): 105301, 2017 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-28139464

RESUMEN

Ultra-thin anodic aluminum oxide (AAO) membranes are efficient templates for the fabrication of patterned nanostructures. Herein, a three-step etching method to control the morphology of AAO is described. The morphological evolution of the AAO during phosphoric acid etching is systematically investigated and a nonlinear growth mechanism during unsteady-state anodization is revealed. The thickness of the AAO can be quantitatively controlled from ∼100 nm to several micrometers while maintaining the tunablity of the pore diameter. The AAO membranes are robust and readily transferable to different types of substrates to prepare patterned plasmonic nanoarrays such as nanoislands, nanoclusters, ultra-small nanodots, and core-satellite superstructures. The localized surface plasmon resonance from these nanostructures can be easily tuned by adjusting the morphology of the AAO template. The custom AAO template provides a platform for the fabrication of low-cost and large-scale functional nanoarrays suitable for fundamental studies as well as applications including biochemical sensing, imaging, photocatalysis, and photovoltaics.

20.
Phys Chem Chem Phys ; 19(39): 27059-27064, 2017 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-28959995

RESUMEN

In order to enhance photocatalysis by broadening light harvesting, bundled TiO2 nanowire bundle arrays are encapsulated with indium tin oxide (ITO) by a self-assembly technique involving anodization, electrochemical etching, and ITO deposition. The plasmonic photocatalyst, which has a multiscale structure with variable nanoscale gaps as well as microscale funnels, shows broadband localized surface plasmon resonance absorption of 84% in the wavelength range between 400 and 2500 nm. The improved photocatalytic efficiency is demonstrated by methyl orange degradation under sunlight illumination. The improvement stems from enhanced light harvesting arising from the localized surface plasmon resonance of the ITO membrane which extends the light response to the visible and NIR regions and excites hot charge carriers.

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