Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Phys Rev Lett ; 126(22): 227402, 2021 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-34152189

RESUMEN

As a newly emergent type-II Dirac semimetal, platinum telluride (PtTe_{2}) stands out from other two dimensional noble-transition-metal dichalcogenides for the unique band structure and novel physical properties, and has been studied extensively. However, the ultrafast response of low energy quasiparticle excitation in terahertz frequency remains nearly unexplored yet. Herein, we employ optical pump-terahertz probe (OPTP) spectroscopy to systematically study the photocarrier dynamics of PtTe_{2} thin films with varying pump fluence, temperature, and film thickness. Upon photoexcitation the terahertz photoconductivity (PC) of PtTe_{2} films shows abrupt increase initially, while the terahertz PC changes into negative value in a subpicosecond timescale, followed by a prolonged recovery process that lasted a few nanoseconds. The magnitude of both positive and negative terahertz PC response shows strongly pump fluence dependence. We assign the unusual negative terahertz PC to the formation of small polaron due to the strong electron-phonon (e-ph) coupling, which is further substantiated by temperature and film thickness dependent measurements. Moreover, our investigations give a subpicosecond timescale of simultaneous carrier cooling and polaron formation. The present study provides deep insights into the underlying dynamics evolution mechanisms of photocarrier in type-II Dirac semimetal upon photoexcitation, which is of crucial importance for designing PtTe_{2}-based optoelectronic devices.

2.
Small ; 16(4): e1905902, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31867892

RESUMEN

Semiconducting nanowires offer many opportunities for electronic and optoelectronic device applications due to their unique geometries and physical properties. However, it is challenging to synthesize semiconducting nanowires directly on a SiO2 /Si substrate due to lattice mismatch. Here, a catalysis-free approach is developed to achieve direct synthesis of long and straight InSe nanowires on SiO2 /Si substrates through edge-homoepitaxial growth. Parallel InSe nanowires are achieved further on SiO2 /Si substrates through controlling growth conditions. The underlying growth mechanism is attributed to a selenium self-driven vapor-liquid-solid process, which is distinct from the conventional metal-catalytic vapor-liquid-solid method widely used for growing Si and III-V nanowires. Furthermore, it is demonstrated that the as-grown InSe nanowire-based visible light photodetector simultaneously possesses an extraordinary photoresponsivity of 271 A W-1 , ultrahigh detectivity of 1.57 × 1014 Jones, and a fast response speed of microsecond scale. The excellent performance of the photodetector indicates that as-grown InSe nanowires are promising in future optoelectronic applications. More importantly, the proposed edge-homoepitaxial approach may open up a novel avenue for direct synthesis of semiconducting nanowire arrays on SiO2 /Si substrates.

3.
Cancer Cell Int ; 18: 87, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29977159

RESUMEN

BACKGROUND: Semaphorin 5A has been linked to tumor growth, invasion, and metastasis in pancreatic cancer. However, the role of semaphorin 5A in cervical cancer is not known. Our aim is to investigate the prognostic value of semaphorin 5A and its potential role in lymphangiogenesis and invasion in cervical cancer. METHODS: In this study, pathological features and clinical data of 232 cervical cancer patients were retrospectively reviewed. Semaphorin 5A protein and mRNA expression was detected by immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction, respectively. In vitro, we determined the role and mechanistic pathways of semaphorin 5A in tumor progression in cervical carcinoma cell lines. RESULTS: Semaphorin 5A expression was significantly higher in stage IIb tumors than in stage Ia, Ib, and IIa tumors. High semaphorin 5A expression was significantly associated with pelvic lymph node metastasis, lymphovascular permeation, and poor survival. Semaphorin 5A induced lymphangiogenesis through a plexin-B/Met/vascular endothelial growth factor-C pathway. Semaphorin 5A also increased cervical cancer cell invasion by stimulating the expression and activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 via PI3K/AKT and plexin-B3. CONCLUSION: Our findings indicate that semaphorin 5A may represent a poor prognostic biomarker and anti-metastasis therapeutic target in cervical cancer.

4.
BMC Musculoskelet Disord ; 19(1): 311, 2018 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-30157832

RESUMEN

BACKGROUND: The age-related osteoporosis is an increasing risk severely threatening the live quality of aged people. Human parathyroid hormone (hPTH) is applied to the therapy of osteoporosis successfully, however, the mechanism, especially the signaling pathway activated in the healing fracture by PTH is still unknown. METHODS: The once daily injections of hPTH(1-34) and GR (1-34) (the PLC deficient analog) into the orchiectomized male mice with bone fracture, were started at the second day after fracture and lasted for 4 weeks. To explore the role of phospholipase C signaling in the androgen-deficient fracture healing, the fracture healing were evaluated via radiography, micro-CT, biomechanics testing, serum biochemistry, bone marrow cell culture and gene expression quantification. RESULTS: After two weeks of fracture, both peptides significantly increased bone mineral density (BMD), bone mass content (BMC) and bone volume (BV/TV) in the healing area. However, compared to hPTH(1-34), GR(1-34) induced more woven bones, the higher BMC and BMD, as well as the less serum TRAP and osteoclasts. After four weeks of treatment, the effects of hPTH(1-34) on fracture healing showed no difference to those of GR(1-34). Consistently, GR(1-34) induced the similar osteogenesis but less osteoclastogenesis under the ex vivo condition immediately after administration compared to hPTH(1-34), which was verified by the weaker activation of RANKL, NFATC1, TRAP and Cathepsin K in GR(1-34) treatment. CONCLUSION: These results indicated that the PLC signaling activated by the intermittent injection of hPTH(1-34) leads to the bone resorption by rapidly activating the osteoclastogenesis in the fracture healing zone.


Asunto(s)
Curación de Fractura/fisiología , Orquiectomía/efectos adversos , Osteogénesis/fisiología , Hormona Paratiroidea/farmacología , Transducción de Señal/fisiología , Fosfolipasas de Tipo C/metabolismo , Animales , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Fracturas del Cuello Femoral/diagnóstico por imagen , Fracturas del Cuello Femoral/tratamiento farmacológico , Fracturas del Cuello Femoral/enzimología , Curación de Fractura/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Orquiectomía/tendencias , Osteogénesis/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
5.
Med Sci Monit ; 23: 1896-1906, 2017 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-28424452

RESUMEN

BACKGROUND Parathyroid hormone (PTH) is an effective anti-osteoporosis agent, after binding to its receptor PTHR1, several signaling pathways, including cAMP/protein kinase A (PKA) and phospholipase C (PLC)/protein kinase C (PKC), are initiated through G proteins; with the cAMP/PKA pathway as the major pathway. Earlier studies have reported that PTHR1 might also activate PKC via a PLC-independent mechanism, but this pathway remains unclear. MATERIAL AND METHODS In HEK293 cells, cAMP accumulation was measured with ELISA and PKC was measured with fluorescence resonance energy transfer (FRET) analysis using CKAR plasmid. In MC3T3-E1 cells, real-time PCR was performed to examine gene expressions. Then assays for cell apoptosis, cell differentiation, alkaline phosphatase activity, and mineralization were performed. RESULTS The FRET analysis found that PTH(1-34), [G1,R19]PTH(1-34) (GR(1-34), and [G1,R19]PTH(1-28) (GR(1-28) were all activated by PKC. The PKC activation ability of GR(1-28) was blocked by cAMP inhibitor (Rp-cAMP) and rescued with the addition of active PKA-α and PKA-ß. The PKC activation ability of GR(1-34) was partially inhibited by Rp-cAMP. In MC3T3-E1 cells, gene expressions of ALP, CITED1, NR4a2, and OSX that was regulated by GR(1-28) were significantly changed by the pan-PKC inhibitor Go6983. After pretreatment with Rp-cAMP, the gene expressions of ALP, CITED1, and OPG were differentially regulated by GR(1-28) or GR(1-34), and the difference was blunted by Go6983. PTH(1-34), GR(1-28), and GR(1-34) significantly decreased early apoptosis and augmented osteoblastic differentiation in accordance with the activities of PKA and PKC. CONCLUSIONS PLC-independent PKC activation induced by PTH could be divided into two potential mechanisms: one was PKA-dependent and associated with PTH(1-28); the other was PKA-independent and associated with PTH(29-34). We also found that PTH could activate PLC-independent PKC via PKA-dependent mechanisms.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Hormona Paratiroidea/metabolismo , Proteína Quinasa C/metabolismo , Células 3T3 , Animales , Apoptosis , Proteínas Portadoras/metabolismo , Diferenciación Celular/efectos de los fármacos , AMP Cíclico/metabolismo , Células HEK293/metabolismo , Humanos , Ratones , Osteoblastos/metabolismo , Fosfoinositido Fosfolipasa C/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Fosfolipasas de Tipo C/metabolismo
6.
J Chem Phys ; 145(8): 084704, 2016 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-27586938

RESUMEN

The presence of grain boundaries is inevitable for chemical vapor deposition (CVD)-grown MoS2 domains owing to various merging behaviors, which greatly limits its potential applications in novel electronic and optoelectronic devices. It is therefore of great significance to unravel the merging behaviors of the synthesized polygon shape MoS2 domains. Here we provide systematic investigations of merging behaviors and electrostatic properties of CVD-grown polycrystalline MoS2 crystals by multiple means. Morphological results exhibit various polygon shape features, ascribed to polycrystalline crystals merged with triangle shape MoS2 single crystals. The thickness of triangle and polygon shape MoS2 crystals is identical manifested by Raman intensity and peak position mappings. Three merging behaviors are proposed to illustrate the formation mechanisms of observed various polygon shaped MoS2 crystals. The combined photoemission electron microscopy and kelvin probe force microscopy results reveal that the surface potential of perfect merged crystals is identical, which has an important implication for fabricating MoS2-based devices.

7.
J Environ Manage ; 182: 595-605, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27544646

RESUMEN

To enhance the quality of human life in a rapidly urbanized world plagued with high transportation, the masterful contribution of improved urban and local air quality cannot be overemphasized. In order to reduce human exposure to near-road air pollution, several approaches including the installation of roadside structural barriers especially in open street areas, such as city entrances are being applied. In the present study, the air quality around real world and idealized green infrastructures was investigated by means of numerical simulation and a short field measurement campaign. Fair agreement was found between ENVI-met modelled and measured particulate matter's concentration data around a realistic vegetation barrier indicating a fair representation of reality in the model. Several numerical experiments were conducted to investigate the influence of barrier type (vegetation/hedge and green wall) and dimensions on near-road air quality. The results show different horizontal/vertical patterns and magnitudes of upwind and downwind relative concentration (with and without a barrier) depending on wind condition, barrier type and dimension. Furthermore, an integrated dispersion-deposition approach was employed to assess the impact on air quality of near-road vegetation barrier. At last, recommendations to city and urban planners on the implementation of roadside structural barriers were made.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Emisiones de Vehículos/análisis , Ciudades , Simulación por Computador , Restauración y Remediación Ambiental , Hidrodinámica , Modelos Teóricos , Material Particulado/análisis , Urbanización , Viento
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(10): 2701-6, 2014 Oct.
Artículo en Zh | MEDLINE | ID: mdl-25739211

RESUMEN

UNLABELLED: Based on Savitzky-Golay (SG) smoothing screening, principal component analysis (PCA) combined with separately supervised linear discriminant analysis (LDA) and unsupervised hierarchical clustering analysis (HCA) were used for non-destructive visible and near-infrared (Vis-NIR) detection for breed screening of transgenic sugarcane. A random and stability-dependent framework of calibration, prediction, and validation was proposed. A total of 456 samples of sugarcane leaves planting in the elongating stage were collected from the field, which was composed of 306 transgenic (positive) samples containing Bt and Bar gene and 150 non-transgenic (negative) samples. A total of 156 samples (negative 50 and positive 106) were randomly selected as the validation set; the remaining samples (negative 100 and positive 200, a total of 300 samples) were used as the modeling set, and then the modeling set was subdivided into calibration (negative 50 and positive 100, a total of 150 samples) and prediction sets (negative 50 and positive 100, a total of 150 samples) for 50 times. The number of SG smoothing points was ex- panded, while some modes of higher derivative were removed because of small absolute value, and a total of 264 smoothing modes were used for screening. The pairwise combinations of first three principal components were used, and then the optimal combination of principal components was selected according to the model effect. Based on all divisions of calibration and prediction sets and all SG smoothing modes, the SG-PCA-LDA and SG-PCA-HCA models were established, the model parameters were optimized based on the average prediction effect for all divisions to produce modeling stability. Finally, the model validation was performed by validation set. With SG smoothing, the modeling accuracy and stability of PCA-LDA, PCA-HCA were signif- icantly improved. For the optimal SG-PCA-LDA model, the recognition rate of positive and negative validation samples were 94.3%, 96.0%; and were 92.5%, 98.0% for the optimal SG-PCA-LDA model, respectively. CONCLUSION: Vis-NIR spectro- scopic pattern recognition combined with SG smoothing could be used for accurate recognition of transgenic sugarcane leaves, and provided a convenient screening method for transgenic sugarcane breeding.


Asunto(s)
Plantas Modificadas Genéticamente/clasificación , Saccharum/genética , Espectroscopía Infrarroja Corta , Cruzamiento , Análisis por Conglomerados , Análisis Discriminante , Hojas de la Planta , Análisis de Componente Principal , Saccharum/clasificación
11.
Neurosci Lett ; 837: 137901, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39019145

RESUMEN

Neurological or neurodevelopmental disorders, such as Parkinson's disease and dyslexia, can impair rhythm perception and production. Deficits in rhythm are associated with poor performance in language, attention, and working memory tasks. Research indicates that retraining rhythmic skills may enhance these related cognitive functions. In this context, using tactile aids for rhythm training emerges as a promising approach for children who do not fully benefit from conventional audiovisual rhythm games. This is because tactile aids can compensate for sensory deficiencies and facilitate more extensive brain activation. In our study, we employed functional near-infrared spectroscopy (fNIRS) to assess the impact of tactile aids on brain cortical activation during rhythmic training in children aged 6-12 years (N = 25). We also measured the participants' spontaneous motor rhythms. The findings indicate that tactile stimulation significantly improves performance in synchronized rhythm tasks compared to audiovisual stimulation alone, particularly enhancing activation in brain regions associated with speech training such as the prefrontal cortex, motor cortex, and temporal areas. These results not only support the application of rhythm training in speech rehabilitation, but also highlight the potential of tactile aids as an effective multisensory learning strategy.

12.
Neurosci Lett ; 818: 137567, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38007085

RESUMEN

BCI games have been widely employed as non-invasive therapeutic interventions for conditions, but their efficacy remains a subject of debate. This study explores the efficacy of two prevalent forms of Brain-Computer Interface (BCI)-based attention training games: video games (VG) and physical games (PG). The effectiveness of these games has been examined through the lens of neuroscience, using functional Near-Infrared Spectroscopy (fNIRS) to monitor cortical activation. After the fNIRS test, subjects completed an Intrinsic Motivation Inventory (IMI) questionnaire. PG tasks activated six channels (L-PFC, R-PFC and R-TL), while VG tasks activated only one (R-PFC). Furthermore, females exhibited stronger activation during PG tasks, while males had none in either. Our findings suggest that under equivalent game rules and themes, PG may prove more effective for cognitive rehabilitation than VG, with stronger intrinsic motivation. We also found this result may exhibit gender differences. Finally, this research offers valuable insights for the future design of BCI-based games from a neuroscience perspective.


Asunto(s)
Interfaces Cerebro-Computador , Masculino , Femenino , Humanos , Espectroscopía Infrarroja Corta/métodos , Encéfalo , Motivación , Atención
13.
Neurosci Lett ; 808: 137260, 2023 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-37075884

RESUMEN

Extrovert-introvert personality can take an active role in affecting people's attitudes, tastes, and behaviors in education. However, little research has been conducted to study whether and how extrovert-introvert personality may influence children's interaction with the attention training system. In this manuscript, we present the results of a user study that not only measured the influence of children's extrovert-introvert personality on their preference for two typical types of attention training systems (i.e., cognitive-based and neurofeedback-based) but also employed functional near-infrared spectroscopy (fNIRS) to investigate how the personality may influence cortical activation in children. Our results show that, for extroverted children, the neurofeedback attention training system elicited significantly greater activation in the prefrontal cortex and posterior parietal cortex, and was more likely to be preferred. The findings could be useful for developing more effective attention training systems based on user personality.


Asunto(s)
Personalidad , Corteza Prefrontal , Humanos , Niño , Escolaridad , Trastornos de la Personalidad , Atención
14.
Medicine (Baltimore) ; 102(41): e35152, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37832133

RESUMEN

BACKGROUND: The optimal drug for treatment with polycystic ovary syndrome (PCOS) was in debate. We did this network meta-analysis to assess the efficacy and safety of different drugs for reducing testosterone levels in women with PCOS. METHODS: We searched studies from inception until January 10, 2023, through PubMed, Embase, and Cochrane Library database. All studies comparing different drugs for reducing testosterone levels in women with polycystic ovary syndrome were included in this network meta-analysis. Outcomes were total testosterone levels, free testosterone levels, and withdraw due to adverse events. We calculated the surface under the cumulative ranking curve (SUCRA) for each treatment. RESULTS: Finally, a total of 13 studies were finally included in this network meta-analysis. In head-to-head comparison, atorvastatin (WMD -3.1, 95% CrI: -3.7 to -2.5), metformin (WMD -2.6, 95% CrI: -3.5 to -1.6), metformin + simvastatin (WMD -2.8, 95% CrI: -4.1 to -1.5), simvastatin (WMD -2.7, 95% CrI: -4.2 to -1.3), spironolactone (WMD -3.1, 95% CrI: -4.3 to -1.9), spironolactone + metformin (WMD -3.2, 95% CrI: -4.5 to -2.0) were all more effective than the placebo, and the difference was statistically significant (P < .05). The SUCRA shows that spironolactone + metformin ranked first (SUCRA, 85.0%), Atorvastatin ranked second (SUCRA, 77.7%), Spironolactone ranked third (SUCRA, 77.2%), and metformin + simvastatin ranked the fourth. The SUCRA of different drugs for free testosterone levels shows that atorvastatin ranked first (SUCRA, 75.0%), spironolactone + metformin ranked second (SUCRA, 5.3%), metformin + simvastain ranked third (SUCRA, 62.6%), and spironolactone ranked the fourth (SUCRA, 56.4%). No statistically significant differences were found between the 2 treatment groups for withdrawn due to adverse events (P > .05). CONCLUSIONS: Considering the network meta-analysis and rankings, atorvastatin was recommended to be the optimal drug for treatment PCOS. However, the optimal dose of atorvastatin was unknown and should be verified by more randomized controlled trials.


Asunto(s)
Metformina , Síndrome del Ovario Poliquístico , Humanos , Femenino , Espironolactona/uso terapéutico , Atorvastatina/uso terapéutico , Metaanálisis en Red , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Metformina/uso terapéutico , Simvastatina/uso terapéutico , Testosterona/uso terapéutico
15.
Front Endocrinol (Lausanne) ; 14: 1118886, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37361541

RESUMEN

Introduction: Immunity is involved in a variety of bone metabolic processes, especially osteoporosis. The aim of this study is to explore new bone immune-related markers by bioinformatics method and evaluate their ability to predict osteoporosis. Methods: The mRNA expression profiles were obtained from GSE7158 in Gene expression Omnibus (GEO), and immune-related genes were obtained from ImmPort database (https://www.immport.org/shared/). immune genes related to bone mineral density(BMD) were screened out for differential analysis. protein-protein interaction (PPIs) networks were used to analyze the interrelationships between different immune-related genes (DIRGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of DIRGs function were performed. A least absolute shrinkage and selection operation (LASSO) regression model and multiple Support Vector Machine-Recursive Feature Elimination (mSVM-RFE) model were constructed to identify the candidate genes for osteoporosis prediction The receiver operator characteristic (ROC) curves were used to validate the performances of predictive models and candidate genes in GEO database (GSE7158,GSE13850).Through the RT - qPCR verify the key genes differentially expressed in peripheral blood mononuclear cells Finally, we constructed a nomogram model for predicting osteoporosis based on five immune-related genes. CIBERSORT algorithm was used to calculate the relative proportion of 22 immune cells. Results: A total of 1158 DEGs and 66 DIRGs were identified between high-BMD and low-BMD women. These DIRGs were mainly enriched in cytokine-mediated signaling pathway, positive regulation of response to external stimulus and the cellular components of genes are mostly localized to external side of plasma membrane. And the KEGG enrichment analysis were mainly involved in Cytokine-cytokine receptor interaction, PI3K-Akt signaling pathway, Neuroactive ligand-receptor interaction,Natural killer cell mediated cytotoxicity. Then five key genes (CCR5, IAPP, IFNA4, IGHV3-73 and PTGER1) were identified and used as features to construct a predictive prognostic model for osteoporosis using the GSE7158 dataset. Conclusion: Immunity plays an important role in the development of osteoporosis.CCR5, IAPP, IFNA4, IGHV3-73 and PTGER1were play an important role in the occurrences and diagnosis of OP.


Asunto(s)
Leucocitos Mononucleares , Osteoporosis , Femenino , Humanos , Fosfatidilinositol 3-Quinasas , Osteoporosis/genética , Aprendizaje Automático , Biología Computacional , Citocinas
16.
Neuron ; 111(10): 1609-1625.e6, 2023 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-36921602

RESUMEN

Stroke prognosis is negatively associated with an elevation of serum bilirubin, but how bilirubin worsens outcomes remains mysterious. We report that post-, but not pre-, stroke bilirubin levels among inpatients scale with infarct volume. In mouse models, bilirubin increases neuronal excitability and ischemic infarct, whereas ischemic insults induce the release of endogenous bilirubin, all of which are attenuated by knockout of the TRPM2 channel or its antagonist A23. Independent of canonical TRPM2 intracellular agonists, bilirubin and its metabolic derivatives gate the channel opening, whereas A23 antagonizes it by binding to the same cavity. Knocking in a loss of binding point mutation for bilirubin, TRPM2-D1066A, effectively antagonizes ischemic neurotoxicity in mice. These findings suggest a vicious cycle of stroke injury in which initial ischemic insults trigger the release of endogenous bilirubin from injured cells, which potentially acts as a volume neurotransmitter to activate TRPM2 channels, aggravating Ca2+-dependent brain injury.


Asunto(s)
Accidente Cerebrovascular , Canales Catiónicos TRPM , Animales , Ratones , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Bilirrubina/metabolismo , Ratones Noqueados , Encéfalo/metabolismo , Infarto , Calcio/metabolismo
17.
Biosensors (Basel) ; 12(9)2022 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-36140099

RESUMEN

This paper presents the development of a compact, three-electrode electrochemical device functionalized by a biocompatible layer of hyaluronic acid methacrylate (HAMA) hydrogel for the adsorptive removal of detrimental lead (Pb(II)) ions in aqueous solutions. An adsorption mechanism pertaining to the observed analytical performance of the device is proposed and further experimentally corroborated. It is demonstrated that both the molecular interactions originating from the HAMA hydrogel and electrochemical accumulation originating from the electrode beneath contribute to the adsorption capability of the device. Infrared spectral analysis reveals that the molecular interaction is mainly induced by the amide functional group of the HAMA hydrogel, which is capable of forming the Pb(II)-amide complex. In addition, inductively coupled plasma mass spectrometric (ICP-MS) analysis indicates that the electrochemical accumulation is particularly valuable in facilitating the adsorption rate of the device by maintaining a high ion-concentration gradient between the solution and the hydrogel layer. ICP-MS measurements show that 94.08% of Pb(II) ions present in the test solution can be adsorbed by the device within 30 min. The HAMA hydrogel-modified electrochemical devices exhibit reproducible performance in the aspect of Pb(II) removal from tap water, with a relative standard deviation (RSD) of 1.28% (for n = 8). The experimental results suggest that the HAMA hydrogel-modified electrochemical device can potentially be used for the rapid, on-field remediation of Pb(II) contamination.


Asunto(s)
Ácido Hialurónico , Contaminantes Químicos del Agua , Adsorción , Amidas , Hidrogeles , Concentración de Iones de Hidrógeno , Iones , Cinética , Plomo , Metacrilatos , Soluciones , Agua/química , Contaminantes Químicos del Agua/química
18.
Ann Transl Med ; 9(20): 1538, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34790744

RESUMEN

BACKGROUND: The role of caudal-related homeobox 2 (CDX2) in the pathogenesis of non-small cell lung cancer (NSCLC) is unclear. The purpose of this study was to investigate the mRNA (message RNA) expression of CDX2 in NSCLC, and to determine its relationship with miR-744 (microRNA744) and its potential as a biomarker of NSCLC. METHODS: MiR-744 is overexpressed in A549, H460, and H1299 cell lines. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression. A chromatin immunoprecipitation (ChIP) essay was performed to determine the CDX2 binding sites. We then conducted a luciferase reporter essay to analyze interaction between MiR-744 and 3'UTRs (the 3' untranslated sequences). The migration and Boyden chamber method were used to study cell mobility. RESULTS: In this study, we found that ectopic CDX2 increased the expression of miR-744, while the attenuation of CDX2 reduced the expression of miR-744 by qRT-PCR. Chromatin immunoprecipitation experiments confirmed that CDX2 directly binds to the promoter of miR-744. The luciferase reporter assay further verified the binding sites of -347 to -358 bp in the most likely promoter like sequence of miR-744. CDX2-induced up-regulation of miR-744 can significantly promote the migration and invasion of NSCLC cells, while overexpression CDX2 is sufficient to rescue the migration and invasion capacity of these cells following knockdown of miR-744. CONCLUSIONS: In summary, our results confirmed for the first time the regulatory mechanism of CDX2 on miR-744 transcription and provided a potential mechanism for CDX2 as an oncogene in lung cancer.

19.
ACS Appl Mater Interfaces ; 13(50): 60209-60215, 2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-34878241

RESUMEN

The transformation from silent to functional synapses is accompanied by the evolutionary process of human brain development and is essential to hardware implementation of the evolutionary artificial neural network but remains a challenge for mimicking silent to functional synapse activation. Here, we developed a simple approach to successfully realize activation of silent to functional synapses by controlled sulfurization of chemical vapor deposition-grown indium selenide crystals. The underlying mechanism is attributed to the migration of sulfur anions introduced by sulfurization. One of our most important findings is that the functional synaptic behaviors can be modulated by the degree of sulfurization and temperature. In addition, the essential synaptic behaviors including potentiation/depression, paired-pulse facilitation, and spike-rate-dependent plasticity are successfully implemented in the partially sulfurized functional synaptic device. The developed simple approach of introducing sulfur anions in layered selenide opens an effective new avenue to realize activation of silent synapses for application in evolutionary artificial neural networks.


Asunto(s)
Materiales Biomiméticos/metabolismo , Indio/metabolismo , Redes Neurales de la Computación , Compuestos de Selenio/metabolismo , Azufre/metabolismo , Sinapsis/metabolismo , Materiales Biomiméticos/química , Humanos , Indio/química , Ensayo de Materiales , Compuestos de Selenio/química , Azufre/química , Sinapsis/química
20.
Bone ; 135: 115326, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32200023

RESUMEN

Teriparatide (hPTH(1-34)) exhibits both osteoanabolic and osteocatabolic effects. We generated a novel PTH analog by duplicating the PTH(29-34) domain to hPTH(3-34) (named MY-1), which was identified to activate PKC but not PLC and cAMP/PKA signaling. It increased osteo-differentiation but did not affect osteoclastogenesis and RANKL expression in primary osteoblasts or bone marrow cells. MY-1 and hPTH(1-34) increased the synthesis and decreased the degradation οf ß-catenin protein in osteoblasts, while PKC inhibitor blunted such effects. In vivo results indicated that intermittent MY-1 and hPTH(1-34) prevented bone loss in ovariectomized mice, and that MY-1 infusion increased bone volume in normal mice. Histological analysis observed more osteoclasts surrounding the cancellous bone surface in hPTH(1-34), but not MY-1 treated mice. We conclude that MY-1 mimicked the osteoanabolic but not the osteocatabolic effects of hPTH(1-34), which is related to PKC and ß-catenin signaling. Such anabolic-only analog provides a new strategy to study PTH's versatile functions and design new medicines to treat osteoporosis and bone defects.


Asunto(s)
Hormona Paratiroidea , Teriparatido , Animales , Ratones , Osteoblastos/metabolismo , Osteogénesis , Hormona Paratiroidea/metabolismo , Hormona Paratiroidea/farmacología , Transducción de Señal/fisiología , Teriparatido/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA