Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Am Chem Soc ; 146(14): 9679-9687, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38478888

RESUMEN

Jumping crystals of racemic mixtures of asparagine monohydrate have been presented in this contribution to emphasize the key role of molecular chirality in governing the direction of macroscopic motions. When heated at the specific faces of the single crystals, a pair of enantiomorphs jump in opposite directions, which are further utilized for chiral resolution. The hydrogen-bonded networks between asparagine molecules in a specific direction provide oriented channels for the escape of water molecules during the dehydration, serving as a foundation for the directional crystal jumping. Our findings not only lay the foundation for the future creation of directed actuation systems based on dynamic crystals but shall also guide the efforts to reveal the correlation between chirality and motion across diverse realms of knowledge.

2.
Chemistry ; : e202401550, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38925570

RESUMEN

Stereoselective inhibition aided by "tailor-made" polymeric additives is an efficient approach to obtain enantiopure compounds through conglomerate crystallization. The chemical and configurational match between the side groups of polymers and the molecules of undesired enantiomer is considered to be a necessary condition for successful stereoseparation. Whereas in this contribution, we present an effective resolution of chiral pharmaceuticals by using cellulose acetates as the additives, which stereoselectively reside on the specific crystal faces of one enantiomer and inhibit its crystal nucleation and growth through helical pattern and supramolecular interaction complementarity. An investigation of nimodipine serves as a case study to highlight the novelty of this strategy wherein R-crystals exhibiting an impressive enantiomeric excess value of 97% can be attained by employing a mere 0.01 wt% cellulose acetate. Guaifenesin and phenyl lactic acid are also well-resolved by utilizing this methodology. Our work not only brings about a brand-new design strategy for "tailor-made" additives, but will also promote the further exploration of the endless potential for utilizing natural biomolecules in chiral recognition and resolution.

3.
Macromol Rapid Commun ; : e2400295, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38771981

RESUMEN

Theoretically, separating the positive and negative charge centers of the chain segments of dielectric elastomers (DEs) is a viable alternative to the conventional decoration of chain backbone with polar handles, since it can dramatically increase the dipole vector and hence the dielectric constant (ε') of the DEs while circumvent the undesired impact of the decorated polar handles on the dielectric loss (tan δ). Herein, a novel and universal method is demonstrated to achieve effective separation of the charge centers of chain segments in homogeneous DEs by steric hindrance engineering, i.e., by incorporating a series of different included angle-containing building blocks into the networks. Both experimental and simulation results have shown that the introduction of these building blocks can create a spatially fixed included angle between two adjacent chain segments, thus separating the charge center of the associated region. Accordingly, incorporating a minimal amount of these building blocks (≈5 mol%) can lead to a considerably sharp increase (≈50%) in the ε' of the DEs while maintaining an extremely low tan δ (≈0.006@1 kHz), indicating that this methodology can substantially optimize the dielectric performance of DEs based on a completely different mechanism from the established methods.

4.
Cell Mol Biol (Noisy-le-grand) ; 70(6): 122-128, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38836672

RESUMEN

Hypospadias, an oft-occurring penis anomaly, ranks among neonatal's foremost birth defects. The SRD5A2 can affect male reproductive system development and is abnormally expressed in its epithelial cells. This study exploration aimed at understanding the role of SRD5A2 in the development of hypospadias from a molecular perspective. SRD5A2 levels in hypospadias primary cells were analyzed by Western blot, while targeted interaction with miR-1199-5p was ascertained by dual-luciferase gene reporter assay. In vitro biological experiments were used to confirm the biological function of SRD5A2 in hypospadias. SRD5A2 expression was significantly upregulated, and miR-1199-5p expression was significantly downregulated in hypospadias primary cells. Intervention of SRD5A2 expression can affect cell proliferation, migration, invasion, EMT, and the expression of cell cycle-related proteins. Additionally, we found that SRD5A2 is regulated by upstream miR-1199-5p and can enhance the effect of SRD5A2 on hypospadias cells. Conclusions Silencing SRD5A2 promotes cell proliferation, invasion, and migration blocks the cell cycle at the G1 phase, and simultaneously promotes EMT, cell cycle, and cell proliferation-related protein expression. The biological function of SRD5A2 in hypospadias cells is regulated by miR-1199-5p. SRD5A2 may be an effective therapeutic target for hypospadias.


Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa , Movimiento Celular , Proliferación Celular , Transición Epitelial-Mesenquimal , Hipospadias , Proteínas de la Membrana , MicroARNs , Hipospadias/genética , Hipospadias/patología , Hipospadias/metabolismo , Masculino , Humanos , Transición Epitelial-Mesenquimal/genética , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Proliferación Celular/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , MicroARNs/genética , MicroARNs/metabolismo , Movimiento Celular/genética
5.
Ann Surg ; 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37753654

RESUMEN

OBJECTIVE: To develop and validate TraumaICDBERT, a natural language processing algorithm to predict injury ICD-10 diagnosis codes from trauma tertiary survey notes. SUMMARY BACKGROUND DATA: The adoption of ICD-10 diagnosis codes in clinical settings for injury prediction is hindered by the lack of real-time availability. Existing natural language processing algorithms have limitations in accurately predicting injury ICD-10 diagnosis codes. METHODS: Trauma tertiary survey notes from hospital encounters of adults between January 2016 and June 2021 were used to develop and validate TraumaICDBERT, an algorithm based on BioLinkBERT. The performance of TraumaICDBERT was compared to Amazon Web Services Comprehend Medical, an existing natural language processing tool. RESULTS: A dataset of 3,478 tertiary survey notes with 15,762 4-character injury ICD-10 diagnosis codes was analyzed. TraumaICDBERT outperformed Amazon Web Services Comprehend Medical across all evaluated metrics. On average, each tertiary survey note was associated with 3.8 (standard deviation: 2.9) trauma registrar-extracted 4-character injury ICD-10 diagnosis codes. CONCLUSIONS: TraumaICDBERT demonstrates promising initial performance in predicting injury ICD-10 diagnosis codes from trauma tertiary survey notes, potentially facilitating the adoption of downstream prediction tools in clinical settings.

6.
Biochem Biophys Res Commun ; 643: 175-185, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36621113

RESUMEN

BACKGROUND: Thoracic aortic aneurysm (TAA) is a silent but dangerous cardiovascular disease. Understanding molecular mechanisms of TAA on single-cell level might provide new strategies for preventing and treating TAA. METHODS: Single-cell RNA sequencing was performed on control and aneurysmal thoracic aorta to find out specific cell clusters and cell types. Western blot and histological staining were used to verify the findings of single-cell transcriptome analysis. Characteristics of Versican (VCAN) overexpressed myofibroblast was evaluated through bioinformatic methods and experimental validation. RESULTS: A total of 3 control and 8 TAA specimens were used for single-cell transcriptome analysis including 48,128 thoracic aortic cells. Among these cells, we found out a specific cell cluster containing both hallmarks of smooth muscle cell (SMC) and fibroblast. Thus, we defined these cells as myofibroblast. Further single-cell transcriptome analysis identified VCAN as a cellular marker of myofibroblast. Western blot and histological staining revealed that VCAN(+) myofibroblast was significantly increased in TAA specimens compared with control individuals. Differential analysis, functional, pathway enrichment analysis and cell-cell communication analysis demonstrated that VCAN(+) myofibroblast was closely associated with previous reported TAA associated pathological process including SMC proliferation, SMC migration and extracellular matrix (ECM) disruption. Pathway analysis found out significant activation of PI3K-AKT signaling pathway within VCAN(+) myofibroblast, which was further confirmed by experimental validation. CONCLUSIONS: Single-cell RNA sequencing identified VCAN(+) myofibroblast as a typical cellular hallmark of TAA. These cells might participate in the pathogenesis of TAA through activation of PI3K-AKT signaling pathway to link SMC proliferation, SMC migration and ECM disruption.


Asunto(s)
Aneurisma de la Aorta Torácica , Versicanos , Humanos , Versicanos/genética , Versicanos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Miofibroblastos/metabolismo , Análisis de Expresión Génica de una Sola Célula , Aneurisma de la Aorta Torácica/genética , Aneurisma de la Aorta Torácica/metabolismo , Aorta Torácica/metabolismo , Transducción de Señal
7.
Opt Express ; 31(19): 30030-30039, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37710555

RESUMEN

Analyzing the longitudinal-mode of a pump can significantly prevent optical damage to solid media and expand the applications of solid media in high repetition rate stimulated Brillouin scattering (SBS). In this study, a Fabry-Pérot etalon was used to control the number of longitudinal-mode in a pump laser output. We studied the output characteristics of SBS in fused silica by considering both single- and multi-longitudinal-mode pumping. We analyzed and compared variations in the SBS threshold, energy reflectivity, linewidth, and waveform characteristics. The experimental results indicated that a pump operating in a single-longitudinal-mode had a 14% lower SBS threshold than one operating in a multi-longitudinal-mode. The proportion of the weak longitudinal-mode in the multi-longitudinal-mode was close to the threshold difference. The damage threshold of the multi-longitudinal-mode pumps was approximately 35 mJ (@12 ns, f = 300 mm). The Stokes linewidth and waveform exhibited opposite trends as the energy changed. Due to the time-bandwidth product, the linewidth and waveform tended to converge towards the pump. This study emphasizes the importance of using a single-longitudinal-mode pump in the development and use of solid-state SBS gain media.

8.
BMC Pediatr ; 23(1): 504, 2023 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-37805482

RESUMEN

BACKGROUND: Children with hypospadias are at risk of serious physical and mental health problems, including abnormal urination, sexual dysfunction, and infertility. The sole available treatment is the surgical restoration of genital appearance and function. Proximal hypospadias (PH) correction is more challenging and carries a higher risk of complications than does distal hypospadias correction, with a higher likelihood of postoperative complications requiring additional surgery, resulting in considerable economic and psychological strain for families. Herein, we aimed to identify factors associated with complications following one-stage PH repair with urethral plate disconnection. METHODS: We retrospectively analyzed data from 236 children who underwent PH repair at our center between December 2020 and December 2022. We collected information on age, surgical procedure, length of the reconstructed urethra (LRU), glans width (GW), ventral curvature, surgical approach, preoperative androgen use, suture type, presence of prostatic utricle, body mass index, season of surgery, anesthesia type, low birth weight, preterm birth, follow-up period, and complications. Surgical complications included urethral fistulas, urethral diverticula, anastomotic strictures, urethral strictures, glans dehiscence, and penile curvature recurrences. The study population was divided into complication and no-complication groups, and univariate and multivariate analyses were conducted. RESULTS: Of the 236 patients with PH who had a median follow-up of 10.0 (8.0, 14.0) months, 79 were included (33.5%) in the complication group and 157 were included (66.5%) in the no-complication group. In the univariate analysis, age (P < 0.001), LRU (P < 0.001), degree of penile curvature (P = 0.049), and PH with prostatic utricle (P = 0.014) were significantly associated with complications after PH repair. In the multivariate logistic regression analysis, LRU (P<0.001, odds ratio [OR] = 3.396, 95% confidence interval [CI]: 2.229-5.174) and GW (P = 0.004, OR = 0.755, 95%CI: 0.625-0.912) were independent factors influencing postoperative complications. The optimal LRU threshold was 4.45 cm (area under the curve, 0.833; sensitivity, 0.873; specificity, 0.873; P<0.001, OR = 3.396, 95% CI: 2.229-5.174). CONCLUSIONS: LRU and GW are independent factors affecting PH complications. An LRU of < 4.45 cm and an increased GW can reduce the risk of complications.


Asunto(s)
Hipospadias , Nacimiento Prematuro , Recién Nacido , Niño , Masculino , Femenino , Humanos , Lactante , Hipospadias/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Procedimientos Quirúrgicos Urológicos Masculinos/efectos adversos , Procedimientos Quirúrgicos Urológicos Masculinos/métodos , Nacimiento Prematuro/etiología , Factores de Riesgo , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía
9.
Small ; 18(51): e2205010, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36328738

RESUMEN

Commercial masks have significant drawbacks, including low water vapor transmission efficiency and limited ability to inhibit harmful microorganisms, whereas in this contribution, a series of Janus microsphere membranes are developed with hierarchical structures by quenching and crystallizing 12-hydroxystearic acid and halicin layer-by-layer on a polypropylene non-woven fabric, laminating them with hydrophilic cotton fibers in a one-pot process, and further demonstrate the potential of this composite system as masks. Through further optimization, excellent superhydrophobic/superhydrophilic properties (contact angle 157.1°/0°), superior filtering effects (93.54% for PM2.5 and 98.35% for PM10 ), with a low-filtration resistance (57 Pa) and a quality factor of up to 0.072 Pa-1 are achieved, all better than that of commercial N95 masks. In addition, the membrane allows for the directional transport of water vapor from the inside out, increasing the water vapor transmission rate by more than 20% compared with the monolayer hydrophobic microsphere membrane. It also has a bactericidal capacity of over 99.9999% against Escherichia coli and is tested for robustness and stability in various extreme environments. This work may shed light on designing novel filter media with versatile functions, meanwhile, the materials can also be used in protective equipment against the new coronavirus.


Asunto(s)
Material Particulado , Vapor , Material Particulado/análisis , Microesferas , Filtración , Esterilización
10.
BMC Med Res Methodol ; 22(1): 136, 2022 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-35549854

RESUMEN

BACKGROUND: Manually extracted data points from health records are collated on an institutional, provincial, and national level to facilitate clinical research. However, the labour-intensive clinical chart review process puts an increasing burden on healthcare system budgets. Therefore, an automated information extraction system is needed to ensure the timeliness and scalability of research data. METHODS: We used a dataset of 100 synoptic operative and 100 pathology reports, evenly split into 50 reports in training and test sets for each report type. The training set guided our development of a Natural Language Processing (NLP) extraction pipeline system, which accepts scanned images of operative and pathology reports. The system uses a combination of rule-based and transfer learning methods to extract numeric encodings from text. We also developed visualization tools to compare the manual and automated extractions. The code for this paper was made available on GitHub. RESULTS: A test set of 50 operative and 50 pathology reports were used to evaluate the extraction accuracies of the NLP pipeline. Gold standard, defined as manual extraction by expert reviewers, yielded accuracies of 90.5% for operative reports and 96.0% for pathology reports, while the NLP system achieved overall 91.9% (operative) and 95.4% (pathology) accuracy. The pipeline successfully extracted outcomes data pertinent to breast cancer tumor characteristics (e.g. presence of invasive carcinoma, size, histologic type), prognostic factors (e.g. number of lymph nodes with micro-metastases and macro-metastases, pathologic stage), and treatment-related variables (e.g. margins, neo-adjuvant treatment, surgical indication) with high accuracy. Out of the 48 variables across operative and pathology codebooks, NLP yielded 43 variables with F-scores of at least 0.90; in comparison, a trained human annotator yielded 44 variables with F-scores of at least 0.90. CONCLUSIONS: The NLP system achieves near-human-level accuracy in both operative and pathology reports using a minimal curated dataset. This system uniquely provides a robust solution for transparent, adaptable, and scalable automation of data extraction from patient health records. It may serve to advance breast cancer clinical research by facilitating collection of vast amounts of valuable health data at a population level.


Asunto(s)
Neoplasias de la Mama , Procesamiento de Lenguaje Natural , Neoplasias de la Mama/cirugía , Registros Electrónicos de Salud , Femenino , Humanos , Almacenamiento y Recuperación de la Información , Evaluación de Resultado en la Atención de Salud , Informe de Investigación
11.
Sensors (Basel) ; 22(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36236786

RESUMEN

The single-beam bathymetric light detection and ranging (LiDAR) system 1 (SBLS-1), which is equipped with a 532-nm-band laser projector and two concentric-circle receivers for shallow- and deep-water echo signals, is a lightweight and convenient prototype instrument with low energy consumption. In this study, a novel LiDAR bathymetric method is utilized to achieve single-beam and dual-channel bathymetric characteristics, and an adaptive extraction method is proposed based on the cumulative standard deviation of the peak and trough, which is mainly used to extract the signal segment and eliminate system and random noise. To adapt the dual-channel bathymetric mechanism, an automatic channel-selection method was used at various water depths. A minimum half-wavelength Gaussian iterative decomposition is proposed to improve the detection accuracy of the surface- and bottom-water waveform components and ensure bathymetric accuracy and reliability. Based on a comparison between the experimental results and in situ data, it was found that the SBLS-1 obtained a bathymetric accuracy and RMSE of 0.27 m and 0.23 m at the Weifang and Qingdao test fields. This indicates that the SBLS-1 was bathymetrically capable of acquiring a reliable, high-efficiency waveform dataset. Hence, the novel LiDAR bathymetric method can effectively achieve high-accuracy near-shore bathymetry.

12.
Opt Express ; 29(2): 2411-2430, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33726437

RESUMEN

In nearshore bathymetry based on the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2), water refraction causes a position displacement of the seafloor signal photon, decreasing the bathymetric accuracy. A novel refraction-correction method is proposed for the ICESat-2. Based on the experimental results and statistical analysis, it is illustrated that the displacement in elevation direction reaches several meters at the relative depth. The displacement in the along- and cross-track directions is very small, ranging from millimeters to centimeters. Finally, the relationship of refraction displacements with various incident angles and water depths is analyzed in detail, revealing the nearshore bathymetry characteristics of ICESat-2.

13.
Environ Res ; 201: 111454, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34111437

RESUMEN

A marine oil spill is one of the most challenging environmental issues, resulting in severe long-term impacts on ecosystems and human society. Oil dispersants are widely applied as a treating agent in oil spill response operations. The usage of dispersants significantly changes the behaviors of dispersed oil and consequently challenges the oil fingerprinting analysis. In this study, machine learning was first introduced to analyze oil fingerprinting by developing a data-driven binary classification framework. The modeling integrated dimensionality reduction algorithms (e.g., principal component analysis, PCA) to distinguish. Five groups of biomarkers, including terpanes, steranes, triaromatic steranes (TA-steranes), monoaromatic steranes (MA-steranes), and diamantanes, were selected. Different feature spaces were created from the diagnostic index of biomarkers, and six ML algorithms were applied for comparative analysis and optimizing the modeling process, including k-nearest neighbor (KNN), support vector classifier (SVC), random forest classifier (RFC), decision tree classifier (DTC), logistic regression classifier (LRC), and ensemble vote classifier (EVC). Hyperparameter optimization and cross-validation through GridSearchCV were applied to prevent overfitting and increase the model accuracy. Model performance was evaluated by model score and F-score through confusion matrices. The results indicated that the RFC algorithm from the diamantanes dataset performed the best. It delivered the highest F-score (0.871) versus the lowest F-score (0.792) from the EVC algorithm from the TA-steranes dataset by PCA with a variance of 95%. Therefore, diamantanes were recommended as the most suitable biomarker for distinguishing WCO and CDO to aid oil fingerprinting under the conditions in this study. The results proved the proposed method as a potential analysis tool for oil spill source identification through ML-aided oil fingerprinting. The study also showed the value of ML methods in oil spill response research and practice.


Asunto(s)
Ecosistema , Contaminación por Petróleo , Algoritmos , Aprendizaje Automático , Análisis de Componente Principal
14.
Angew Chem Int Ed Engl ; 60(41): 22424-22431, 2021 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-34375037

RESUMEN

Electronic microdevices of self-bending coronene crystals are developed to reveal an unexplored link between mechanical deformation and crystal function. First, a facile approach towards length/width/curvature-controllable micro-crystals through bottom-up solution crystallization was proposed for high processability and stability. The bending crystal devices show a significant increase beyond seven orders of magnitude in conductivity than the straight ones, providing the first example of deformation-induced function enhancement in crystal materials. Besides, double effects caused by bending, including the change of π electron level as well as the enhancement of carrier mobility, were determined, respectively by the X-ray photoelectric spectroscopy and X-ray crystallography to coexist, contributing to the conductivity improvement. Our findings will promote future creation of flexible organic crystal systems with deformation-enhanced functional features towards customized smart devices.

15.
Org Biomol Chem ; 17(13): 3409-3415, 2019 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-30869715

RESUMEN

Rare multiple fluorescence properties including aggregation-induced emission and polymorphism/shape/size-dependent emission were found coexisting in a class of typical non-steroidal anti-inflammatory analgesic drugs, fenamates, which could provide a new approach toward future drug evaluation. Different from the complexity and biological incompatibility of the traditional AIE molecular design, this work opens new avenues to the development of new AIE systems.


Asunto(s)
Analgésicos/química , Antiinflamatorios no Esteroideos/química , Fenamatos/química , Colorantes Fluorescentes/química , Evaluación de Medicamentos , Fluorescencia , Estructura Molecular , Tamaño de la Partícula , Teoría Cuántica
16.
Sensors (Basel) ; 18(5)2018 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-29783740

RESUMEN

A quartz tuning fork (QTF) has been widely used as a force sensor of the frequency modulation atomic force microscope due to its ultrahigh stiffness, high quality factor and self-sensing nature. However, due to the bulky structure and exposed surface electrode arrangement, its application is limited, especially in liquid imaging of in situ biological samples, ionic liquids, electrochemical reaction, etc. Although the complication can be resolved by coating insulating materials on the QTF surface and then immersing the whole QTF into the liquid, it would result in a sharp drop of the quality factor, which will reduce the sensitivity of the QTF. To solve the problem, a novel method, called the balanced trolling quartz tuning fork (BT-QTF), is introduced here. In this method, two same probes are glued on both prongs of the QTF separately while only one probe immersed in the liquid. With the method, the hydrodynamic interaction can be reduced, thus the BT-QTF can retain a high quality factor and constant resonance frequency. The stable small vibration of the BT-QTF can be achieved in the liquid. Initially, a theoretical model is presented to analyze the sensing performance of the BT-QTF in the liquid. Then, the sensing performance analysis experiments of the BT-QTF have been performed. At last, the proposed method is applied to atomic force microscope imaging different samples in the liquid, which proves its feasibility.

17.
Appl Opt ; 56(16): 4861-4867, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29047626

RESUMEN

Non-metallic plasmonic materials have recently attracted research interest due to their adjustable plasmonic material properties and the potential low loss, which is important to plasmonic waveguides with ultrahigh mode confinement. In this paper, we analyzed the mode properties of four types of plasmonic waveguides based on noble metals, aluminum-zinc-oxide (AZO), and TiN, where the propagation length and mode size are chosen to compare the figures of merit. It is found that AZO has the smallest imaginary part of permittivity in the near-infrared region, while AZO waveguides have propagation lengths comparable to those of Cu waveguides but shorter than those of Au and Ag waveguides. Furthermore, due to the larger real part of permittivities, the mode sizes of the AZO and TiN waveguides are smaller than those of the metal waveguides, in particular, for the insulator-metal-insulator waveguide and dielectric-loaded plasmonic waveguide. AZO/ZnO films with tunable carrier density between 1.8×1017/cm3 and 8.6×1020/cm3 were grown by pulsed-laser deposition. Metal-like properties, i.e., negative real part of permittivity around 1550 nm, were observed, predicting an interesting candidate in the plasmonic optical interconnect.

18.
Angew Chem Int Ed Engl ; 56(36): 10761-10765, 2017 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-28691396

RESUMEN

A one-step ligand-free method based on an adsorption-precipitation process was developed to fabricate iridium/cerium oxide (Ir/CeO2 ) nanocatalysts. Ir species demonstrated a strong metal-support interaction (SMSI) with the CeO2 substrate. The chemical state of Ir could be finely tuned by altering the loading of the metal. In the carbon dioxide (CO2 ) hydrogenation reaction it was shown that the chemical state of Ir species-induced by a SMSI-has a major impact on the reaction selectivity. Direct evidence is provided indicating that a single-site catalyst is not a prerequisite for inhibition of methanation and sole production of carbon monoxide (CO) in CO2 hydrogenation. Instead, modulation of the chemical state of metal species by a strong metal-support interaction is more important for regulation of the observed selectivity (metallic Ir particles select for methane while partially oxidized Ir species select for CO production). The study provides insight into heterogeneous catalysts at nano, sub-nano, and atomic scales.

19.
Dev Psychopathol ; 28(2): 415-31, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26073189

RESUMEN

This study investigated the influences of neighborhood factors (residential stability and neighborhood disadvantage) and variants of the serotonin transporter linked polymorphic region (5-HTTLPR) genotype on the development of substance use among African American children aged 10-24 years. To accomplish this, a harmonized data set of five longitudinal studies was created via pooling overlapping age cohorts to establish a database with 2,689 children and 12,474 data points to span ages 10-24 years. A description of steps used in the development of the harmonized data set is provided, including how issues such as the measurement equivalence of constructs were addressed. A sequence of multilevel models was specified to evaluate Gene × Environment effects on growth of substance use across time. Findings indicated that residential instability was associated with higher levels and a steeper gradient of growth in substance use across time. The inclusion of the 5-HTTLPR genotype provided greater precision to the relationships in that higher residential instability, in conjunction with the risk variant of 5-HTTLPR (i.e., the short allele), was associated with the highest level and steepest gradient of growth in substance use across ages 10-24 years. The findings demonstrated how the creation of a harmonized data set increased statistical power to test Gene × Environment interactions for an under studied sample.


Asunto(s)
Negro o Afroamericano/genética , Interacción Gen-Ambiente , Genotipo , Características de la Residencia , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Trastornos Relacionados con Sustancias/etiología , Adolescente , Negro o Afroamericano/psicología , Alelos , Niño , Femenino , Predisposición Genética a la Enfermedad , Humanos , Estudios Longitudinales , Masculino , Trastornos Relacionados con Sustancias/genética , Trastornos Relacionados con Sustancias/psicología , Adulto Joven
20.
J Urol ; 192(2): 575-82, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24518784

RESUMEN

PURPOSE: Identifying potential targets would improve therapeutic planning and disease management. Therefore, we investigated whether the novel identified dependence receptor UNC5D acts as a tumor suppressor in bladder malignancies. MATERIALS AND METHODS: We assessed the UNC5D level in a panel of 15 primary bladder carcinomas and 6 cell lines using real-time reverse transcriptase-polymerase chain reaction and Western blot. MTT assay, TUNEL staining, colony formation assay and Western blot were done in cells untransfected and transfected with UNC5D vector, siUNC5D or siDAPK. RESULTS: UNC5D was dramatically down-regulated in bladder cancer tissue samples and malignant cell lines. Restoration of UNC5D expression in bladder cancer cells lacking endogenous UNC5D expression suppressed cell proliferation and survival. Cisplatin treatment significantly induced UNC5D expression and DAPK dephosphorylation while UNC5D knockdown decreased bladder cancer cell sensitivity to cisplatin. DAPK silencing significantly inhibited the effect of UNC5D on apoptosis induced by cisplatin. CONCLUSIONS: Our study suggests that UNC5D may have important roles as a novel suppressor in bladder cancer via the UNC5D/DAPK pathway.


Asunto(s)
Antineoplásicos/uso terapéutico , Apoptosis , Cisplatino/uso terapéutico , Regulación hacia Abajo , Receptores de Superficie Celular/fisiología , Neoplasias de la Vejiga Urinaria/patología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Cisplatino/farmacología , Femenino , Humanos , Masculino , Células Tumorales Cultivadas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA