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1.
Proc Natl Acad Sci U S A ; 120(21): e2218775120, 2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37186832

RESUMEN

Quantum computing technology may soon deliver revolutionary improvements in algorithmic performance, but it is useful only if computed answers are correct. While hardware-level decoherence errors have garnered significant attention, a less recognized obstacle to correctness is that of human programming errors-"bugs." Techniques familiar to most programmers from the classical domain for avoiding, discovering, and diagnosing bugs do not easily transfer, at scale, to the quantum domain because of its unique characteristics. To address this problem, we have been working to adapt formal methods to quantum programming. With such methods, a programmer writes a mathematical specification alongside the program and semiautomatically proves the program correct with respect to it. The proof's validity is automatically confirmed-certified-by a "proof assistant." Formal methods have successfully yielded high-assurance classical software artifacts, and the underlying technology has produced certified proofs of major mathematical theorems. As a demonstration of the feasibility of applying formal methods to quantum programming, we present a formally certified end-to-end implementation of Shor's prime factorization algorithm, developed as part of a framework for applying the certified approach to general applications. By leveraging our framework, one can significantly reduce the effects of human errors and obtain a high-assurance implementation of large-scale quantum applications in a principled way.

2.
BMC Cancer ; 24(1): 573, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724951

RESUMEN

BACKGROUND: Microsatellite instability-high (MSI-H) has emerged as a significant biological characteristic of colorectal cancer (CRC). Studies reported that MSI-H CRC generally had a better prognosis than microsatellite stable (MSS)/microsatellite instability-low (MSI-L) CRC, but some MSI-H CRC patients exhibited distinctive molecular characteristics and experienced a less favorable prognosis. In this study, our objective was to explore the metabolic transcript-related subtypes of MSI-H CRC and identify a biomarker for predicting survival outcomes. METHODS: Single-cell RNA sequencing (scRNA-seq) data of MSI-H CRC patients were obtained from the Gene Expression Omnibus (GEO) database. By utilizing the copy number variation (CNV) score, a malignant cell subpopulation was identified at the single-cell level. The metabolic landscape of various cell types was examined using metabolic pathway gene sets. Subsequently, functional experiments were conducted to investigate the biological significance of the hub gene in MSI-H CRC. Finally, the predictive potential of the hub gene was assessed using a nomogram. RESULTS: This study revealed a malignant tumor cell subpopulation from the single-cell RNA sequencing (scRNA-seq) data. MSI-H CRC was clustered into two subtypes based on the expression profiles of metabolism-related genes, and ENO2 was identified as a hub gene. Functional experiments with ENO2 knockdown and overexpression demonstrated its role in promoting CRC cell migration, invasion, glycolysis, and epithelial-mesenchymal transition (EMT) in vitro. High expression of ENO2 in MSI-H CRC patients was associated with worse clinical outcomes, including increased tumor invasion depth (p = 0.007) and greater likelihood of perineural invasion (p = 0.015). Furthermore, the nomogram and calibration curves based on ENO2 showed potential prognosis predictive performance. CONCLUSION: Our findings suggest that ENO2 serves as a novel prognostic biomarker and is associated with the progression of MSI-H CRC.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Colorrectales , Progresión de la Enfermedad , Inestabilidad de Microsatélites , Fosfopiruvato Hidratasa , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Fosfopiruvato Hidratasa/genética , Fosfopiruvato Hidratasa/metabolismo , Pronóstico , Femenino , Masculino , Regulación Neoplásica de la Expresión Génica , Transición Epitelial-Mesenquimal/genética , Persona de Mediana Edad , Nomogramas , Análisis de la Célula Individual , Variaciones en el Número de Copia de ADN
3.
Inorg Chem ; 63(7): 3525-3534, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38324525

RESUMEN

The quest for efficient and tunable luminescent materials has been at the forefront of research in the fields of chemistry and materials science. This work delves into the investigation of the luminescence properties of Er3+ ions triggered by 1% Te4+ in the environmentally benign perovskite Cs2NaYbCl6 (CNYC) crystals, aiming to enhance their efficiency and tune the luminescence color. The ratio of the green (2H11/2, 4S3/2-4I15/2) to red (4F9/2-4I15/2) emissions of Er3+ can be freely tunable by varying the concentration of Er3+ and producing the defects induced by codoping Te4+. The calculations reveal that the multiexcitonic excitations of Er3+ stem from f-f (4I15/2-4G11/2, 2H9/2) rather than d-f transitions. The broadened excitation, tuning of color, and enhancement of efficiency achieved in the luminescence perovskite crystals Cs2NaYbCl6:Te4+, Er3+ (CNYC:Te4+,Er3+) presents promising opportunities for the development of advanced optoelectronic devices with superior performance. Moreover, our investigation demonstrates the tunable luminescence response of CNYC:Er3+ to temperature variations, offering potential applications in temperature sensing.

4.
Cancer Immunol Immunother ; 72(7): 2045-2056, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36795124

RESUMEN

Immunotherapy based on immune checkpoint inhibitors (ICIs) has provided revolutionary results in treating various cancers. However, its efficacy in colorectal cancer (CRC), especially in microsatellite stability-CRC, is limited. This study aimed to observe the efficacy of personalized neoantigen vaccine in treating MSS-CRC patients with recurrence or metastasis after surgery and chemotherapy. Candidate neoantigens were analyzed from whole-exome and RNA sequencing of tumor tissues. The safety and immune response were assessed through adverse events and ELISpot. The clinical response was evaluated by progression-free survival (PFS), imaging examination, clinical tumor marker detection, circulating tumor DNA (ctDNA) sequencing. Changes in health-related quality of life were measured by the FACT-C scale. A total of six MSS-CRC patients with recurrence or metastasis after surgery and chemotherapy were administered with personalized neoantigen vaccines. Neoantigen-specific immune response was observed in 66.67% of the vaccinated patients. Four patients remained progression-free up to the completion of clinical trial. They also had a significantly longer progression-free survival time than the other two patients without neoantigen-specific immune response (19 vs. 11 months). Changes in health-related quality of life improved for almost all patients after the vaccine treatment. Our results shown that personalized neoantigen vaccine therapy is likely to be a safe, feasible and effective strategy for MSS-CRC patients with postoperative recurrence or metastasis.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias Colorrectales , Humanos , Antígenos de Neoplasias , Vacunas contra el Cáncer/uso terapéutico , Neoplasias Colorrectales/genética , Inmunoterapia/métodos , Inmunoterapia Activa , Repeticiones de Microsatélite , Calidad de Vida
5.
Small ; 19(21): e2300862, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36811284

RESUMEN

Single-component white light emitters based on the all-inorganic perovskites will act as outstanding candidates for applications in solid-state lighting thanks to their abundant energy states for self-trapped excitons (STE) with ultra-high photoluminescence (PL) efficiency. Here, a complementary white light is realized by dual STEs emissions with blue and yellow colors in a single-component perovskite Cs2 SnCl6 :La3+ microcrystal (MC). The dual emission bands centered at 450 and 560 nm are attributed to the intrinsic STE1 emission in host lattice Cs2 SnCl6 and the STE2 emission induced by the heterovalent La3+ doping, respectively. The hue of the white light can be tunable through energy transfer between the two STEs, the variation of excitation wavelength, and the Sn4+ /Cs+ ratios in starting materials. The effects of the doping heterovalent La3+ ions on the electronic structure and photophysical properties of the Cs2 SnCl6 crystals and the created impurity point defect states are investigated by the chemical potentials calculated using density functional theory (DFT) and confirmed by the experimental results. These results provide a facile approach to gaining novel single-component white light emitter and offer fundamental insights into the defect chemistry in the heterovalent ions doped perovskite luminescent crystals.

6.
Sensors (Basel) ; 23(10)2023 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-37430600

RESUMEN

This paper is concerned with the problem of state estimation for nonlinear multi-sensor systems with cross-correlated noise and packet loss compensation. In this case, the cross-correlated noise is modeled by the synchronous correlation of the observation noise of each sensor, and the observation noise of each sensor is correlated with the process noise at the previous moment. Meanwhile, in the process of state estimation, since the measurement data may be transmitted in an unreliable network, data packet dropout will inevitably occur, leading to a reduction in estimation accuracy. To address this undesirable situation, this paper proposes a state estimation method for nonlinear multi-sensor systems with cross-correlated noise and packet dropout compensation based on a sequential fusion framework. Firstly, a prediction compensation mechanism and a strategy based on observation noise estimation are used to update the measurement data while avoiding the noise decorrelation step. Secondly, a design step for a sequential fusion state estimation filter is derived based on an innovation analysis method. Then, a numerical implementation of the sequential fusion state estimator is given based on the third-degree spherical-radial cubature rule. Finally, the univariate nonstationary growth model (UNGM) is combined with simulation to verify the effectiveness and feasibility of the proposed algorithm.

7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 53(6): 976-980, 2022 Nov.
Artículo en Zh | MEDLINE | ID: mdl-36443037

RESUMEN

Objective: To investigate the main factors affecting the surgical level of major amputations in patients with severe diabetic foot. Methods: A case-control study was conducted to analyze the clinical data of severe diabetic foot patients who had major amputations and were admitted to the Intensive Care Unit (ICU), Air Force Hospital of PLA Eastern Theater Command between July 2020 and July 2022. According to their surgical level of amputation, patients were divided into transtibial amputation (TT) group and transfemoral amputation (TF) group. Correlation analysis was performed with the clinical data of the patients, and multivariate logistic regression was performed to screen for relevant factors affecting the surgical level of major amputation. Results: The data of 48 patients with major amputations were collected, including 15 patients in the TT group and 33 patients in the TF group. The proportion of patients who had cardiovascular and cerebrovascular complications in the TT group was lower than that in the TF group (26.67% [4/15] vs. 57.58% [19/33], P<0.05), the proportion of patients who had lower extremity arterial intervention history was higher in the TT group than that in the TF group (40% [6/15] vs. 9.09% [3/33], P<0.05), and the proportion of patients who had elevated creatinine level was lower in the TT group than that in the TF group (70.31±22.98 vs. 127.98±108.38, P<0.05). Moreover, the history of lower extremity arterial intervention may be an independent protective factor for determining the surgical level of major amputations (odds ratio [ OR]=0.15, 95% confidence interval [ CI]: 0.03-0.72, P=0.018). Conclusion: History of cardiovascular and cerebrovascular diseases, serum creatinine level and history of lower extremity arterial intervention are the main factors affecting the surgical level of major amputations in patients with severe diabetic foot, and the history of lower extremity arterial intervention may be an independent protective factor.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Humanos , Pie Diabético/cirugía , Estudios de Casos y Controles , Amputación Quirúrgica , Hospitalización , Unidades de Cuidados Intensivos
8.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 891-894, 2021 Sep 10.
Artículo en Zh | MEDLINE | ID: mdl-34487539

RESUMEN

OBJECTIVE: To explore the genetic basis for a juvenile with maturity-onset diabetes of the young type 12(MODY12). METHODS: High-throughput sequencing was carried out to screen for the variants. Candidate variant was verified by Sanger sequencing. Pathogenity of the variant was predicted by searching the genetic databases and analysis by using bioinformatic software. RESULTS: Genetic testing indicated that the patient and his mother have both carried a heterozygous c.3976G>A variant (p.Glu1326Lys) in exon 32 of the ABCC8 gene. Prediction of the protein structure suggested the variant to be deleterious. Based on the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be uncertain significance. CONCLUSION: Whether the c.3976G>A variant of the ABCC8 gene is the cause of the disease in this patient or not depends on the functional studies and more case data. Above finding has enriched the spectrum of ABCC8 gene variants.


Asunto(s)
Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 2/genética , Pruebas Genéticas , Genómica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación
9.
J Cell Physiol ; 235(1): 254-266, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31237697

RESUMEN

Accumulated evidence suggested the importance of the Rho/Rho-kinase (ROCK) signaling pathway in cancer proliferation and invasion. However, its role in colorectal carcinoma (CRC) is not well understood. This study evaluated the effect of ROCK signaling pathway on CRC behavior on the basis of a novel Rho/ROCK inhibitor RKI-1447. Here, we found RKI-1447 could drastically suppress HCT-8 and HCT-116 cell growth and promoted apoptosis. Our in vitro data indicated suppressed cytoskeletal dynamics induced by RKI-1447 inhibition on mitochondrial respiration, which was evidenced by basal and maximal respiration rates, and ATP production. Simultaneously, cellular basal and maximal glycolytic rates, and glycolytic capacity were also reduced in response to RKI-1447. Moreover, RKI-1447 caused excessive reactive oxygen species generation and membrane depolarization as well as activated ER-stress. We also demonstrated CHOP is essential for RKI-1447 induced cell apoptosis. Finally, we proved inhibition of ROCK by RKI-1447 could effectively inhibit CRC growth in vivo. Taken together, this study demonstrated that inhibition of ROCK signaling pathway by RKI-1447 could suppress CRC via cytoskeleton associated mitochondrial dysfunction and cellular bioenergetics disruption. Our data suggest RKI-1447 may be an attractive antitumor drug candidate for the treatment of CRC.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Metabolismo Energético/efectos de los fármacos , Dinámicas Mitocondriales/efectos de los fármacos , Tiazoles/farmacología , Urea/análogos & derivados , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Glucólisis/efectos de los fármacos , Células HCT116 , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Mitocondrias/metabolismo , Invasividad Neoplásica/patología , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Transcripción CHOP/metabolismo , Urea/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasas Asociadas a rho/antagonistas & inhibidores
10.
Small ; 16(1): e1905234, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31797530

RESUMEN

Experimental variation of the volume ratio (filling factor: i.e., volume of nanoparticles (NPs) compared with that of medium) of nanocomposite materials with doped lanthanide ions demonstrates that it has a significant affect upon local field effects. Lanthanum orthophosphate NPs are doped with Eu3+ and/or Tb3+ and immersed in organic solvents and lead borate glasses for Tb3+ 5 D4 lifetime measurements. For media with a refractive index (nmed ) less than that of LaPO4 (nnp = 1.79), the 5 D4 emission decay rate increases with increasing volume ratio of the NPs, whereas for nmed > 1.79, the decay rate decreases with increasing volume ratio. Fitting with the model of Pukhov provides an estimation of the radiative lifetime of 5 D4 and the quantum yield. Energy transfer (ET) from Tb3+ to Eu3+ occurs in co-doped LaPO4 NPs with excitation into a Tb3+ absorption band. The ET rate is independent on nmed and the energy transfer efficiency decreases with an increase in nmed . The behavior of ET rate with regard to the local field is consistent with the Dexter, but not Förster, equation for ET rate involving the electric dipole-electric dipole mechanism. This has consequences when using the spectroscopic ruler approach to measure distances between donor-acceptor chromophores.

11.
Mol Ther ; 27(5): 1039-1050, 2019 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-30852137

RESUMEN

Histone deacetylase inhibitors (HDACis) are the recommended treatment for many solid tumors; however, resistance is a major clinical obstacle for their efficacy. High levels of the transcription factor nuclear factor erythroid 2 like-2 (Nrf2) in cancer cells suggest a vital role in chemoresistance, and regulation of autophagy is one mechanism by which Nrf2 mediates chemoresistance. Although the molecular mechanisms underlying this activity are unclear, understanding them may ultimately improve therapeutic outcomes following HDACi treatment. In this study, we found that HDACi treatment increased Nrf2 mRNA and protein levels and enhanced Nrf2 transcriptional activity. Conversely, Nrf2 knockdown or inhibition blocked HDACi-induced autophagy. In addition, a microRNA (miRNA) array identified upregulation of miR-129-3p in response to Nrf2 overexpression. Chromatin immunoprecipitation assays confirmed miR-129-3p to be a direct Nrf2 target. RepTar and RNAhybrid databases indicated mammalian target of rapamycin (mTOR) as a potential miR-129-3p target, which we experimentally confirmed. Finally, Nrf2 inhibition or miR-129-3p in combination with HDACis increased cell death in vitro and in vivo. Collectively, these results demonstrated that Nrf2 regulates mTOR during HDACi-induced autophagy through miRNA-129-3p and inhibition of this pathway could enhance HDACi-mediated cell death.


Asunto(s)
MicroARNs/genética , Factor 2 Relacionado con NF-E2/genética , Neoplasias/tratamiento farmacológico , Serina-Treonina Quinasas TOR/genética , Animales , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Redes Reguladoras de Genes/genética , Xenoinjertos , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Ratones , Factor 2 Relacionado con NF-E2/antagonistas & inhibidores , Neoplasias/genética , Neoplasias/patología
12.
Small ; 15(7): e1803898, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30667586

RESUMEN

Silicon carbide (SiC) is one of the most important third-generation semiconductor materials. However, the chemical robustness of SiC makes it very difficult to process, and only very limited methods are available to fabricate nanostructures on SiC. In this work, a hybrid anodic and metal-assisted chemical etching (MACE) method is proposed to fabricate SiC nanowires based on wet etching approaches at room temperature and under atmospheric pressure. Through investigations of the etching mechanism and optimal etching conditions, it is found that the metal component plays at least two key roles in the process, i.e., acting as a catalyst to produce hole carriers and introducing band bending in SiC to accumulate sufficient holes for etching. Through the combined anodic and MACE process the required electrical bias is greatly lowered (3.5 V for etching SiC and 7.5 V for creating SiC nanowires) while enhancing the etching efficiency. Furthermore, it is demonstrated that by tuning the etching electrical bias and time, various nanostructures can be obtained and the diameters of the obtained pores and nanowires can range from tens to hundreds of nanometers. This facile method may provide a feasible and economical way to fabricate SiC nanowires and nanostructures for broad applications.

13.
EMBO J ; 33(2): 157-70, 2014 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-24413018

RESUMEN

For decades, neuroscientists have used enriched preparations of synaptic particles called synaptosomes to study synapse function. However, the interpretation of corresponding data is problematic as synaptosome preparations contain multiple types of synapses and non-synaptic neuronal and glial contaminants. We established a novel Fluorescence Activated Synaptosome Sorting (FASS) method that substantially improves conventional synaptosome enrichment protocols and enables high-resolution biochemical analyses of specific synapse subpopulations. Employing knock-in mice with fluorescent glutamatergic synapses, we show that FASS isolates intact ultrapure synaptosomes composed of a resealed presynaptic terminal and a postsynaptic density as assessed by light and electron microscopy. FASS synaptosomes contain bona fide glutamatergic synapse proteins but are almost devoid of other synapse types and extrasynaptic or glial contaminants. We identified 163 enriched proteins in FASS samples, of which FXYD6 and Tpd52 were validated as new synaptic proteins. FASS purification thus enables high-resolution biochemical analyses of specific synapse subpopulations in health and disease.


Asunto(s)
Encéfalo/citología , Citometría de Flujo/métodos , Ácido Glutámico/metabolismo , Neuronas/citología , Sinaptosomas/fisiología , Animales , Encéfalo/metabolismo , Separación Celular/métodos , Canales Iónicos/metabolismo , Ratones , Ratones Noqueados , Neuronas/metabolismo , Proteómica , Sinapsis/metabolismo , Proteína 1 de Transporte Vesicular de Glutamato/genética , Proteína 1 de Transporte Vesicular de Glutamato/metabolismo
14.
Nano Lett ; 17(7): 4304-4310, 2017 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-28613891

RESUMEN

Silicon (Si) zigzag nanowires (NWs) have a great potential in many applications because of its high surface/volume ratio. However, fabricating Si zigzag NWs has been challenging. In this work, a diffusion-controlled metal-assisted chemical etching method is developed to fabricate Si zigzag NWs. By tailoring the composition of etchant to change its diffusivity, etching direction, and etching time, various zigzag NWs can be easily fabricated. In addition, it is also found that a critical length of NW (>1 µm) is needed to form zigzag nanowires. Also, the amplitude of zigzag increases as the location approaches the center of the substrate and the length of zigzag nanowire increases. It is also demonstrated that such zigzag NWs can help the silicon substrate for self-cleaning and antireflection. This method may provide a feasible and economical way to fabricate zigzag NWs and novel structures for broad applications.

15.
Nano Lett ; 17(3): 1365-1370, 2017 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-28135103

RESUMEN

Compact graphene film electrodes with a high ion-accessible surface area have the promising potential to realize high-density electrochemical energy storage (or high volumetric capacitance), which is vital for the development of flexible, portable, and wearable energy storage devices. Here, a novel, ultrafast strategy for stitching graphene sheets into films, in which p-phenylenediamine (PPD) molecules are uniformly intercalated between the graphene sheets, is simply constructed at the ethanol/water interface. Due to uniformly interlayer spacing (∼1.1 nm), good wettability, and an interconnected ion transport channel, the binder-free PPD-graphene film with a high packing density (1.55 g cm-3) delivers an ultrahigh volumetric capacitance (711 F cm-3 at a current density of 0.5 A g-1), high rate performance, high power and energy densities, and excellent cycling stability in aqueous electrolytes. This interfacial stitching strategy holds new promise for the future design of enhanced electrochemical energy-storage devices.

16.
Nano Lett ; 17(2): 1014-1019, 2017 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-28103049

RESUMEN

Kinked silicon (Si) nanowires (NWs) have many special properties that make them attractive for a number of applications, such as microfluidics devices, microelectronic devices, and biosensors. However, fabricating NWs with controlled three-dimensional (3D) geometry has been challenging. In this work, a novel method called alternating metal-assisted chemical etching is reported for the fabrication of kinked Si NWs with controlled 3D geometry. By the use of multiple etchants with carefully selected composition, one can control the number of kinks, their locations, and their angles by controlling the number of etchant alternations and the time in each etchant. The resulting number of kinks equals the number times the etchant is alternated, the length of each segment separated by kinks has a linear relationship with the etching time, and the kinking angle is related to the surface tension and viscosity of the etchants. This facile method may provide a feasible and economical way to fabricate novel silicon nanowires, nanostructures, and devices for broad applications.


Asunto(s)
Oro/química , Nanocables/química , Silicio/química , Titanio/química , Microesferas , Nanotecnología , Tamaño de la Partícula , Fenómenos Físicos , Poliestirenos/química , Propiedades de Superficie
17.
Inorg Chem ; 56(11): 6499-6506, 2017 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-28537713

RESUMEN

The resistance to thermal quenching is an essential factor in evaluating the performance of luminescent materials for application in white light emitting diodes (WLEDs). In this work, we studied the site occupancy preference and thermal quenching of luminescence in ß-Ca2P2O7:Bi2+ red phosphor at low (10-300 K) and high temperatures (303-573 K). In ß-Ca2P2O7, the host lattice has four different calcium sites, at which Bi2+dopant can be located. After comparing the change of bond energy when the Bi2+ ions are incorporated into the four calcium sites, we found out that Bi2+ would preferentially occupy the smaller energy variation sites Ci(2) and Ci(1) in this compound, which can be assigned to Bi(2) and Bi(1), respectively. Surprisingly, we noticed that the variation of emission intensity is different under different excitations when the temperature changes from 10 to 300 K. When exciting into the typical absorption of Bi(1) sites at 419 nm, the emission intensity at 300 K remains only 38% as compared to that at 10 K, while exciting into typical Bi(2) absorption at 460 nm, the emission intensity increases to 110%. When further increasing the temperature from 303 to 573 K, we observed a similar phenomenon, and the emission at 460 nm excitation starts to quench at 453 K. The emission intensity at 573 K still remains 86.1% of that at 303 K. This might be attributed to the Bi(2) → Bi(1) energy transfer. It is also evidenced by the time-resolved emission spectra and lifetime values. This work gives new insights into better understanding luminescent behaviors of Bi2+-doped materials with multiple cation sites. This should be helpful in the future when designing the bismuth doped phosphor for WLEDs with better resistance to thermal quenching.

18.
Cell Physiol Biochem ; 36(1): 100-10, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25925090

RESUMEN

AIMS: Changes in the expression of microRNAs (miRNAs) have been found in many cancers. This study aimed to investigate the expression of miR-1294 in patients with esophageal squamous cell carcinoma (ESCC) and its effect on prognosis. The underlying mechanism was explored as well. METHODS: We examined the expression of miRNA in human ESCC cancer tissues and adjacent non-tumor controls using quantitative reverse transcription polymerase chain reaction (qRT-PCR). And the relationship between expressions of miR-1294 and ESCC prognosis was analyzed in this study. Over-expression and knock-down methods were used to investigate the biological functions of miRNA-1294. The effect of miRNA-1294 on cell proliferation was evaluated by MTT. Besides, the function of miR-1294 on cell migration and invasion were evaluated by transwell assays. RESULTS: MiR-1294 was significantly down-regulated in human ESCC tissues compared with the non-tumor controls tissues (P=0.014). And patients with low miR-1294 expression had a significantly poorer prognosis than those with a high miR-1294 expression (P=0.040). Negative association was defined between the expression of miR-1294 and the c-MYC expression in ESCC patients (Pearson correlation, r=-0.299, P=0.0079). Additionally, it was found that miR-1294 suppress esophageal cancer cells proliferation, migration and invasion capacity through targeting c-MYC in vitro. CONCLUSIONS: Down-regulation of miR-1294 correlates with poor prognosis of ESCC. It's partially due to the reduced function of c-MYC. This study may give insight into the understanding of pathogenesis of esophageal cancer and provide evidence for diagnosis and treatment of esophageal cancer.


Asunto(s)
Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/patología , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Regiones no Traducidas 3' , Anciano , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Regulación hacia Abajo , Neoplasias Esofágicas/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Regulación hacia Arriba
19.
Inorg Chem ; 54(12): 6028-34, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-26020692

RESUMEN

The resistance of a luminescent material to thermal quenching is essential for the application in high power LEDs. Usually, thermal luminescence quenching becomes more and more serious as the activator concentration increases. Conversely, we found here that a red phosphor Sr2P2O7:Bi(2+) is one of the exceptions to this as we studied the luminescence properties at low (10-300 K) and high (300-500 K) temperatures. As Bi(2+) ions are incorporated into Sr2P2O7, they exhibit the emissions at ∼660 and ∼698 nm at room temperature and are encoded, hereafter, as Bi(1) and Bi(2) due to the substitutions for two different crystallographic sites Sr(1) and Sr(2), respectively, in the compound. However, they will not substitute for these sites equally. At lower dopant concentration, they will occupy preferentially Sr(2) sites partially due to size match. As the concentration increases, more Bi(2+) ions start to occupy the Sr(1) sites. This can be verified by the distinct changes of emission intensity ratio of Bi(2) to Bi(1). As environment temperature increases, the thermal quenching happens, but it can be suppressed by the Bi(2+) concentration increase. This becomes even more pronounced in Bi(2+) heavily doped sample as we decompose the broad emission band into separated Bi(1) and Bi(2) Gaussian peaks. For the sample, the Bi(1) emission at ∼660 nm even shows antithermal-quenching particularly at higher temperatures. This phenomenon is accompanied by the blue shift of the overall emission band and almost no changes of lifetimes. A mechanism is proposed due to volume expansion of the unit cell, the increase of Bi(1) content, and temperature dependent energy transfer between Bi(2) and Bi(1). This work helps us better understand the complex luminescent behavior of Bi(2+) doped materials, and it will be helpful to design in the future the heavily doped phosphor for WLEDs with even better resistance to thermal quenching.

20.
World J Surg Oncol ; 13: 44, 2015 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-25889229

RESUMEN

BACKGROUND: Previous studies regarding the association between cruciferous vegetable intake and pancreatic cancer risk have reported inconsistent results. We conducted a meta-analysis to demonstrate the potential association between them. METHODS: A systematic literature search of papers was conducted in March 2014 using PubMed, EMBASE, and Web of Science, and the references of the retrieved articles were screened. The summary odds ratios (ORs) with 95% confidence interval (CI) for the highest versus the lowest intake of cruciferous vegetables were calculated. RESULTS: Four cohort and five case-control studies were eligible for inclusion. We found a significantly decreased risk of pancreatic cancer associated with the high intake of cruciferous vegetables (OR 0.78, 95% CI 0.64-0.91). Moderate heterogeneity was detected across studies (P = 0.065). There was no evidence of significant publication bias based on Begg's funnel plot (P = 0.917) or Egger's test (P = 0.669). CONCLUSIONS: Cruciferous vegetable intake might be inversely associated with pancreatic cancer risk. Because of the limited number of studies included in this meta-analysis, further well-designed prospective studies are warranted to confirm the inverse association between cruciferous vegetable intake and risk of pancreatic cancer.


Asunto(s)
Dieta , Neoplasias Pancreáticas/etiología , Neoplasias Pancreáticas/prevención & control , Verduras , Estudios de Casos y Controles , Humanos , Pronóstico , Factores de Riesgo
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