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1.
J Cell Mol Med ; 22(11): 5477-5485, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30133116

RESUMO

Recently, it was reported that long non-coding RNAs (lncRNAs) participated in promoting hepatocellular carcinoma (HCC) initiation and progression. Herein, we reported that the expression level of LINC01287 was elevated in HCC cell lines and tissues. LINC01287 down-regulation inhibited HCC cells growth and invasion both in vitro and in vivo. LINC01287 exerted as a ceRNA and negatively regulated miR-298 expression. MYB was identified as a downstream target of miR-298. The miR-298/MYB axis mediated LINC01287's effect on HCC. To the best of our knowledge, our findings provided the first evidence that LINC01287 functioned as an oncogene in HCC. LINC01287 may be a candidate prognostic biomarker and a target for new therapies in HCC patients.


Assuntos
Carcinoma Hepatocelular/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myb/genética , RNA Longo não Codificante/genética , Animais , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Xenoenxertos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia
2.
Tumour Biol ; 39(2): 1010428317690999, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28231734

RESUMO

Abnormal expression of long non-coding RNA often contributes to unrestricted growth of cancer cells. Long non-coding RNA XIST expression is upregulated in several cancers; however, its modulatory mechanisms have not been reported in hepatocellular carcinoma. In this study, we found that XIST expression was significantly increased in hepatocellular carcinoma tissues and cell lines. XIST promoted cell cycle progression from the G1 phase to the S phase and protected cells from apoptosis, which contributed to hepatocellular carcinoma cell growth. In addition, we revealed that there was reciprocal repression between XIST and miR-139-5p. PDK1 was identified as a direct target of miR-139-5p. We proposed that XIST was responsible for hepatocellular carcinoma cell proliferation, and XIST exerted its function through the miR-139-5p/PDK1 axis.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , MicroRNAs/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/biossíntese , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Estudos de Casos e Controles , Linhagem Celular Tumoral , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Piruvato Desidrogenase Quinase de Transferência de Acetil , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
3.
Nanotechnology ; 28(40): 405201, 2017 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-28836505

RESUMO

We report the results of finite element simulations of the ON state characteristic of VO2-based threshold switching devices and compare the results with experimental data. The model is based on thermally induced threshold switching (thermal runaway) and successfully reproduces the I-V characteristics showing the formation and growth of the conductive filament in the ON state. Furthermore, we compare the I-V characteristics for two VO2 films with different electrical conductivities in the insulating and metallic phases as well as those based on TaO x and NbO x functional layers.

4.
Environ Geochem Health ; 36(1): 107-15, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23567976

RESUMO

To study the effect of fluorine on the oxidative stress in coal-burning fluorosis, we investigated the environmental characteristics of coal-burning endemic fluorosis combined with fluorine content surveillance in air, water, food, briquette, and clay binder samples from Bijie region, Guizhou Province, southwest of China. The activities of antioxidant enzymes including copper/zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and level of lipid peroxidation such as malondialdehyde (MDA) were measured in serum samples obtained from subjects residing in the Bijie region. Expression of the Cu/Zn-SOD gene was assessed by quantitative reverse transcriptase PCR (qRT-PCR). Our results showed that people suffering from endemic fluorosis (the high and low exposure groups) had much higher MDA level. Their antioxidant enzyme activities and Cu/Zn-SOD gene expression levels were lower when compared to healthy people (the control group). Fluorosis can decrease the activities of antioxidant enzymes, which was associated with exposure level of fluorine. Down-regulation of Cu/Zn-SOD expression may play an important role in the aggravation of oxidative stress in endemic fluorosis.


Assuntos
Carvão Mineral , Exposição Ambiental/análise , Enzimas/sangue , Fluorose Dentária/enzimologia , Fluorose Dentária/genética , Superóxido Dismutase/genética , Adolescente , Adulto , Poluentes Atmosféricos/análise , Estudos de Casos e Controles , Catalase/sangue , China/epidemiologia , Minas de Carvão , Água Potável/análise , Água Potável/química , Exposição Ambiental/efeitos adversos , Feminino , Fluoretos/análise , Flúor/efeitos adversos , Flúor/urina , Fluorose Dentária/epidemiologia , Glutationa Peroxidase/sangue , Humanos , Peroxidação de Lipídeos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Estresse Oxidativo , Adulto Jovem
5.
Chemosphere ; 350: 141043, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38154675

RESUMO

Fishy odor, as an offensive and unpleasant odor, could occur in drinking water source with poor nutrition, it is usually considered to be associated with odor-producing microalgae. However, the specific relations among fishy odor, fishy odorants and responsible microalgae were not elucidated comprehensively. In this paper, the odor-causing compounds generated from six microalgae with fishy odor characteristic, isolated in drinking water source Tongyu River, were identified simultaneously. The sensory evaluation result indicated that Tongyu River was principally related to fishy odor (odor intensity 6.5-7.6). Correspondingly, seven, nine, seven, six, seven and seven olfactory detection peaks (ODP) were screened by combining data of GC/O/MS and GC/GC/TOFMS in Cyclotella, Cryptomonas ovate, Melosira, Dinobryon sp., Synedra and Ochromonas sp., which were isolated in Tongyu River and cultured in laboratory. Totally twenty odor-causing compounds, including hexanal, 2-hexenal, 3-hexen-1-ol, heptanal, 1-octen-3-one, 2,4-heptadienal, 2-tetradecanone, 3,5-octadien-2-one, octanal, 1-octen-3-ol, 2-octenal, nonanal, 2,4-octadienal, 2-nonenal, decanal, 2,6-nonadienal, 2-decenal, undecanal, 2,4-decadienal and dodecanal, were screened and identified in all isolated microalgae. Additionally, fishy odor intensity for all identified microalgae increased obviously as microalgae cell number increased and microalgae cell ruptured in cultivation cycles through pearson and spearman correlation analysis. For the first time, twenty odor-causing compounds associating with fishy odor were recognized from six isolated microalgae, which would provide more scientific basis and theoretical support for preventing and treating fishy odor episode of drinking water source.


Assuntos
Diatomáceas , Água Potável , Microalgas , Compostos Orgânicos Voláteis , Odorantes/análise , Água Potável/análise , Olfato , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos Voláteis/análise
6.
J Nanosci Nanotechnol ; 13(6): 4110-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23862457

RESUMO

TiO2 nanotube array thin films have great potential in many fields, such as solar cell, photo catalyst, photo-induced cathodic protection for metals and bioactivity. In order to investigate the formation process of the TiO2 nanotube array thin films, the EIS spectrum and current density were measured during the anodic oxidation. The results showed that the formation process could be divided into four stages. The current density decreased sharply at the first stage, and then increased at the second stage, followed by declining and finally remained constant value. In addition, the current density increased with the anodic voltage. The EIS spectrum varied in different stage. The simulated circuit was composed three sections, the first sections indicated the resistance of the electrolyte, the second one gave the double layer structure between the electrolyte and titanium electrode, the third one was a inductive loop, which represented the anions absorbed on the surface of the TiO2 nanotube's wall. The more cations were absorbed, the higher value of the inductive loop would be. The EIS results showed that the value increased with the outer voltage, which means that more cations were absorbed under the higher anodic voltage.

7.
Comput Math Methods Med ; 2022: 2895575, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35237339

RESUMO

OBJECTIVE: This study sets out to investigate the role of magnetic resonance imaging (MRI) combined with magnetic resonance myelography (MRM) in patients after percutaneous transforaminal endoscopic discectomy (PTED) and to evaluate its value in postoperative rehabilitation. METHODS: The clinical date of 96 patients with lumbar disc herniation (LDH) after PTED was retrospectively analyzed. The enrolled patients were divided into MRI group (n = 32) and MRI + MRM group (n = 64) according to whether MRM was performed. The nerve root sleeve (morphology, deformation) and dural indentation, intervertebral space height (ISH), intervertebral space angle (ISA), degree of pain (Visual Analogue Scale (VAS)), vertebral function (Japanese Orthopaedic Association (JOA)), and long-term recurrence were compared between the two groups. RESULTS: Compared with the MRI group, the MRI + MRM group better displayed nerve root morphology, sheath sleeve deformation, and dural indentation. Both MRI and MRI + MRM showed ISH and ISA changes well. Compared with the MRI group, the MRI + MRM group had a significantly lower VAS score for lumbar and leg pain, a significantly higher JOA score, and a significantly lower 2-year recurrence rate. CONCLUSION: MRM combined with MRI is more beneficial to improve the prognosis of LDH patients after PTED.


Assuntos
Deslocamento do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Mielografia/métodos , Adulto , Biologia Computacional , Discotomia Percutânea , Feminino , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Imagem Multimodal/estatística & dados numéricos , Mielografia/estatística & dados numéricos , Prognóstico
8.
Pain Res Manag ; 2022: 6181478, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35296040

RESUMO

Objective: Transforaminal endoscopic lumbar discectomy (TELD) is an effective treatment for patients with lumbar disc herniation (LDH) with failure of conservative treatment. However, defects in the annulus fibrosus after TELD usually lead to a recurrence of LDH. Platelet-rich plasma (PRP) injection has shown promising potential for the repair of injured tissues. The combination of TELD and PRP injection has rarely been reported. Hence, this study aimed to evaluate the effectiveness, disc remodeling, and recurrence rate of LDH in TELD with or without PRP in LDH treatment. Methods: A total of 108 consecutive patients who underwent TELD were prospectively registered between July 2018 and December 2019 (https://clinicaltrials.gov/ct2/show/ChiCTR1800017228). Fifty-one and fifty-seven patients underwent TELD with PRP injections and TELD only, respectively. The visual analog scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and MacNab criteria were evaluated, and perioperative complications were documented. The disc protrusion, spinal cross-sectional area (SCSA), and disc height were measured on MRI and evaluated preoperatively, postoperatively, and at regular follow-up. Results: All patients were followed up. Clinical improvement was noted in both groups. There were statistical differences in the VAS scores of back and leg pain and ODI between the two groups at 3 months, 6 months, and 1 year follow-up (P < 0.05); the improvement in the PRP group was significant. The disc protrusion and SCSA on MRI in the PRP group showed better improvement, with lower recurrence rate, than that in the control group at the final follow-up (P < 0.05). No adverse events were reported in our study following PRP injection. Conclusion: Our study showed that TELD with PRP injection was a safe and effective treatment for patients with LDH in the medium and long-term follow-up. PRP injection was beneficial for disc remodeling after endoscopic discectomy and decreased the recurrence of LDH.


Assuntos
Deslocamento do Disco Intervertebral , Plasma Rico em Plaquetas , Discotomia , Humanos , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Estudos Prospectivos
9.
Sci Rep ; 11(1): 3938, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594159

RESUMO

Since its first outbreak, Coronavirus Disease 2019 (COVID-19) has been rapidly spreading worldwide and caused a global pandemic. Rapid and early detection is essential to contain COVID-19. Here, we first developed a deep learning (DL) integrated radiomics model for end-to-end identification of COVID-19 using CT scans and then validated its clinical feasibility. We retrospectively collected CT images of 386 patients (129 with COVID-19 and 257 with other community-acquired pneumonia) from three medical centers to train and externally validate the developed models. A pre-trained DL algorithm was utilized to automatically segment infected lesions (ROIs) on CT images which were used for feature extraction. Five feature selection methods and four machine learning algorithms were utilized to develop radiomics models. Trained with features selected by L1 regularized logistic regression, classifier multi-layer perceptron (MLP) demonstrated the optimal performance with AUC of 0.922 (95% CI 0.856-0.988) and 0.959 (95% CI 0.910-1.000), the same sensitivity of 0.879, and specificity of 0.900 and 0.887 on internal and external testing datasets, which was equivalent to the senior radiologist in a reader study. Additionally, diagnostic time of DL-MLP was more efficient than radiologists (38 s vs 5.15 min). With an adequate performance for identifying COVID-19, DL-MLP may help in screening of suspected cases.


Assuntos
COVID-19/diagnóstico por imagem , COVID-19/virologia , Aprendizado Profundo , Modelos Biológicos , SARS-CoV-2/fisiologia , Tomografia Computadorizada por Raios X , Adulto , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Radiologistas
10.
Front Oncol ; 11: 653988, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34109114

RESUMO

OBJECTIVE: The incidence of early stage multiple primary lung cancer (MPLC) has been increasing in recent years, while the ideal strategy for its diagnosis and treatment remains controversial. The present study conducted genomic analysis to identify a new molecular classification method for accurately predicting the diagnosis and therapy for patients with early stage MPLC. METHODS: A total of 240 tissue samples from 203 patients with multiple-non-small-cell lung cancers (NSCLCs) (n = 30), early stage single-NSCLC (Group A, n = 94), and advanced-stage NSCLC (Group B, n = 79) were subjected to targeted multigene panel sequencing. RESULTS: Thirty patients for whom next-generation sequencing was performed on >1 tumor were identified, yielding 45 tumor pairs. The frequencies of EGFR, TP53, RBM10, ERBB2, and CDKN2A mutations exhibited significant differences between early and advanced-stage NSCLCs. The prevalence of the EGFR L858R mutation in early stage NSCLC was remarkably higher than that in advanced-stage NSCLC (P = 0.047). The molecular method classified tumor pairs into 26 definite MPLC tumors and four intrapulmonary metastasis (IM) tumors. A high rate of discordance in driver genetic alterations was found in the different tumor lesions of MPLC patients. The prospective Martini histologic prediction of MPLC was discordant with the molecular method for three patients (16.7%), particularly in the prediction of IM (91.7% discordant). CONCLUSIONS: Comprehensive molecular evaluation allows the unambiguous delineation of clonal relationships among tumors. In comparison, the Martini and Melamed criteria have notable limitations in the recognition of IM. Our results support the adoption of a large panel to supplement histology for strongly discriminating NSCLC clonal relationships in clinical practice.

11.
ACS Omega ; 5(19): 11186-11195, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32455242

RESUMO

Taking reducing the wear of the fixed cone liner of a cone crusher as the starting point, the movement and geometry parameters of the cone crusher are studied using the discrete element method. To improve the service life and working efficiency of the whole cone crusher. The UG model and discrete element Yade model of the cone crusher are established, and the different shapes of the tin ore are represented using Yade's preprocessor through eight different ways of particle combination and superposition. The static friction coefficient between the manganese ore and the cone crusher is studied and calibrated using the slope method. The relative error between the Yade and test results is 1.58%, and the calibration result is 0.44. The repose angle of the manganese ore is studied using the collapse method. The repose angle increases with the increase of the static friction coefficient and the dynamic friction coefficient, but the change trend is different. The effect of the dynamic friction coefficient on the repose angle is obviously greater than that of the static friction coefficient. The dynamic friction coefficient obtained by Yade is 0.042. Taking the swing distance, rotating speed, and bottom angle of the fixed cone as the orthogonal experimental factors of Yade, the regression equation of the fixed cone liner was obtained through the nonlinear processing of SPSS 25.0. According to Matlab R2017b, the influences of the swinging distance, rotating speed, and bottom angle of the fixed cone on the fixed cone liner are obtained. According to Yade's research results, the order of the influence degree of liner wear is: the rotating speed of moving cone, the swinging distance of the fixed cone, and the base angle of fixed rotation. When the swinging distance of the fixed cone is 146 mm, the rotating speed of the moving cone is 198 rpm, the fixed rotation bottom angle is 28°, and the minimum value of the liner wear is 23 mm. Yade's results are consistent with the change trend of the wear amount of the bushing obtained from the test. The research results show the correctness of using the Yade method to study the wear of the fixed cone liner of a cone crusher, which provides a theoretical basis for reducing the wear of the fixed cone liner of a cone crusher, and puts forward a new method to study the wear of relevant parts of a fixed cone crusher. At the same time, the research results are of great significance for achieving energy-saving in mining enterprises.

12.
Korean J Radiol ; 21(4): 505-508, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32174053

RESUMO

The epidemic of 2019 novel coronavirus, later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still gradually spreading worldwide. The nucleic acid test or genetic sequencing serves as the gold standard method for confirmation of infection, yet several recent studies have reported false-negative results of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Here, we report two representative false-negative cases and discuss the supplementary role of clinical data with rRT-PCR, including laboratory examination results and computed tomography features. Coinfection with SARS-COV-2 and other viruses has been discussed as well.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/virologia , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto , Betacoronavirus/isolamento & purificação , COVID-19 , Teste para COVID-19 , Vacinas contra COVID-19 , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/diagnóstico por imagem , Aprendizado Profundo , Reações Falso-Negativas , Humanos , Lactente , Masculino , Pneumonia Viral/diagnóstico por imagem , SARS-CoV-2 , Tomografia Computadorizada por Raios X
13.
Nat Commun ; 10(1): 1628, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967535

RESUMO

Threshold switching devices are of increasing importance for a number of applications including solid-state memories and neuromorphic circuits. Their non-linear characteristics are thought to be associated with a spontaneous (occurring without an apparent external stimulus) current flow constriction but the extent and the underlying mechanism are a subject of debate. Here we use Scanning Joule Expansion Microscopy to demonstrate that, in functional layers with thermally activated electrical conductivity, the current spontaneously and gradually constricts when a device is biased into the negative differential resistance region. We also show that the S-type negative differential resistance I-V characteristics are only a subset of possible solutions and it is possible to have multiple current density distributions corresponding to the same value of the device voltage. In materials with steep dependence of current on temperature the current constriction can occur in nanoscale devices, making this effect relevant for computing applications.

14.
Artif Cells Nanomed Biotechnol ; 47(1): 2830-2837, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31298047

RESUMO

Abnormal expression of microRNAs (miRNAs) contributes to tumour growth and invasion. MiR-326 expression often down-regulates in several kinds of cancer and low expression of miR-326 is linked with poor prognosis in cancer patients. In the present study, we aimed to explore the modulatory mechanism of miR-326 in hepatocellular carcinoma (HCC). miR-326 expression was significantly decreased in HCC cell lines and tissues. miR-326 decreased HCC cell growth by affecting cell-cycle progression and by promoting apoptosis. In addition, miR-326 inhibited HCC cell invasion by decreasing the EMT phenotype. We found that miR-326 functioned as a tumour suppressor by repressing its down-stream target PDK1. C-myc contributed to miR-326 down-regulation through binding at its promoter and inhibited its expression. Based on these results, we conducted a therapeutic experiment by using gold nano-particles (AuNPs) carrying miR-326. Restoration of miR-326 reduced tumour growth in vivo. Our findings suggest that miR-326 may be a candidate prognostic biomarker and a target for new therapies in HCC patients.


Assuntos
Carcinoma Hepatocelular/patologia , Ouro/química , Nanopartículas Metálicas/química , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Portadores de Fármacos/química , Transição Epitelial-Mesenquimal/genética , Humanos , Neoplasias Hepáticas/patologia , MicroRNAs/química , Terapia de Alvo Molecular
15.
J Exp Clin Cancer Res ; 37(1): 149, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30001751

RESUMO

BACKGROUND: The long non-coding RNAs (lncRNAs) have participated in the promotion of hepatocellular carcinoma (HCC) initiation and progression. Nevertheless, the biological role and underlying mechanism of LINC01287 in HCC has never been reported. METHODS: The TGCA database was used to explore the abnormal expression of lncRNAs in HCC. Real-time PCR and in situ hybridization assays were used to examine the expression of LINC01287 in HCC tissues. The clinicopathological characteristics of HCC patients in relation to LINC01287 expression were then analyzed. Infection of cells with the si-LINC01287 lentiviral vector was performed to down-regulate LINC01287 expression in HCC cells. MTT and colony formation assays were performed to examine cell growth ability, and FACS analysis was performed to examine the cell cycle and apoptosis. A Boyden assay was used to examine HCC cell invasion ability, and RNA immunoprecipitation tested the interaction between LINC01287 and miR-298. A luciferase reporter assay was used to examine whether STAT3 was a direct target of miR-298, and chromatin immunoprecipitation (ChIP) was used to examine the potential binding of c-jun to the miR-298 promoter. RESULTS: We revealed that the expression of LINC01287 was increased in HCC cell lines, as well as tissues. Knockdown of LINC01287 decreased HCC cell growth and invasion both in vitro and in vivo. LINC01287 can negatively regulate miR-298 expression by acting as a ceRNA. miR-298 directly targeted STAT3 and inhibited its expression. LINC01287 exerted its function via the miR-298/STAT3 axis in HCC. Interestingly, STAT3 elevated LINC01287 expression via c-jun, which bound to the LINC01287 promoter. A feedback loop was also discovered between LINC01287 and the miR-298/STAT3 axis. CONCLUSIONS: Our data indicated that LINC01287 played an oncogenic role in HCC growth and metastasis and that this lncRNA might serve as a novel molecular target for the treatment of HCC.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , MicroRNAs/metabolismo , Fator de Transcrição STAT3/metabolismo , Carcinoma Hepatocelular/patologia , Transição Epitelial-Mesenquimal , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Fenótipo , Transfecção
16.
ACS Appl Mater Interfaces ; 10(27): 23187-23197, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29912544

RESUMO

The distribution of tantalum and oxygen ions in electroformed and/or switched TaO x-based resistive switching devices has been assessed by high-angle annular dark-field microscopy, X-ray energy-dispersive spectroscopy, and electron energy-loss spectroscopy. The experiments have been performed in the plan-view geometry on the cross-bar devices producing elemental distribution maps in the direction perpendicular to the electric field. The maps revealed an accumulation of +20% Ta in the inner part of the filament with a 3.5% Ta-depleted ring around it. The diameter of the entire structure was approximately 100 nm. The distribution of oxygen was uniform with changes, if any, below the detection limit of 5%. We interpret the elemental segregation as due to diffusion driven by the temperature gradient, which in turn is induced by the spontaneous current constriction associated with the negative differential resistance-type I- V characteristics of the as-fabricated metal/oxide/metal structures. A finite-element model was used to evaluate the distribution of temperature in the devices and correlated with the elemental maps. In addition, a fine-scale (∼5 nm) intensity contrast was observed within the filament and interpreted as due phase separation of the functional oxide in the two-phase composition region. Understanding the temperature-gradient-induced phenomena is central to the engineering of oxide memory cells.

17.
Environ Health Perspect ; 115(4): 659-62, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17450240

RESUMO

We report the results of a coordinated mitigation effort aimed at reducing arsenic (As) exposure in three counties of Guizhou province, China. Mitigation occurred in 2005 and encompassed 21 villages with 47,000 inhabitants, who were exposed to high levels of As in their diet through consumption of As-contaminated chili peppers and corn dried over unventilated stoves that burned coal containing high levels of As. The coal was mined by villagers from local pits. Inhalation of air that contained high levels of As contributed to approximately 25% of the daily As intake of 6-9 mg. Before mitigation, a baseline survey of 45,364 residents in 2004 identified more than 2,800 individuals with arsenicosis. The survey also found that many residents were aware of the health effects of As in general but lacked in-depth understanding of the link between coal use and arsenicosis. Consequently, an overwhelming majority (> 95%) continued to use high-As coal. This survey provided the basis for a health education campaign that promoted lifestyle changes coupled with the shutting down of local coal pits and the installation of 10,000 new stoves with chimneys for ventilation. The cost of the mitigation was about 4 million Yuan RMB (US$500,000) and was financed mostly by the government. A postmitigation response survey in 2005 found that > 85% of the residents now associate the use of coal with arsenicosis; > 90% correctly learned to operate the new ventilated stoves; and > 90% dry corn and chili peppers outdoors in the sun. Urinary As concentrations in the region decreased from 0.198 +/- 0.300 mg/L (n = 144) in 2004 to 0.049 +/- 0.009 mg/L (n = 50) in 2005 in individuals with arsenicosis (p < 0.01), which is consistent with the behavior changes.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Intoxicação por Arsênico/prevenção & controle , Culinária/instrumentação , Adolescente , Intoxicação por Arsênico/epidemiologia , Terapia Comportamental , Criança , China , Carvão Mineral , Culinária/métodos , Dieta , Contaminação de Alimentos , Inquéritos Epidemiológicos , Humanos , Incidência , Estilo de Vida , Educação de Pacientes como Assunto , Ventilação
18.
Nanoscale ; 9(37): 14139-14148, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-28905051

RESUMO

Materials exhibiting insulator to metal transition (IMT) and transition metal oxides showing threshold switching behavior are considered as promising candidates for selector devices for crossbar non-volatile memory application. In this study, we use an electrothermal model to simulate the behavior of nanoscale selectors based on several different functional oxides (TaOx, VO2 and NbO2). We extract the device characteristics, such as threshold voltage (VTH), leakage current, device temperature in the ON state, and the size of the conductive filament as a function of selector diameter and functional layer thickness. In addition, we benchmark these devices in a 1 selector/1 resistor (1S1R) cell with a generic phase change-like memory element. These findings provide an insight into how device performance changes with scaling and help with material selection and design of selectors.

19.
ACS Appl Mater Interfaces ; 9(13): 11704-11710, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28293945

RESUMO

Pulsed and quasi-static current-voltage (I-V) characteristics of threshold switching in TiN/TaOx/TiN crossbar devices were measured as a function of stage temperature (200-495 K) and oxygen flow during the deposition of TaOx. A comparison of the pulsed and quasi-static characteristics in the high resistance part of the I-V revealed that Joule self-heating significantly affected the current and was a likely source of negative differential resistance (NDR) and thermal runaway. The experimental quasi-static I-V's were simulated using a finite element electro-thermal model that coupled current and heat flow and incorporated an external circuit with an appropriate load resistor. The simulation reproduced the experimental I-V including the OFF-state at low currents and the volatile NDR region. In the NDR region, the simulation predicted spontaneous current constriction forming a small-diameter hot conducting filament with a radius of 250 nm in a 6 µm diameter device.

20.
J Health Popul Nutr ; 24(3): 273-6, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17366768

RESUMO

Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases.


Assuntos
Intoxicação por Arsênico/prevenção & controle , Arsênio/efeitos adversos , Carvão Mineral , China , Exposição Ambiental , Educação em Saúde , Nível de Saúde , Humanos , Incineração , Medição de Risco
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