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Despite the exact biological role of HNF1 homolog A (HNF1A) in the regulatory mechanism of glioblastoma (GBM), the molecular mechanism, especially the downstream regulation as a transcription factor, remains to be further elucidated. Immunohistochemistry was used to detect the expression and clinical relevance of HNF1A in GBM patients. CCK8, TUNEL, and subcutaneous tumor formation in nude mice were used to evaluate the effect of HNF1A on GBM in vitro and in vivo. The correction between HNF1A and epidermal growth factor receptor pathway substrate 8 (EPS8) was illustrated by bioinformatics analysis and luciferase assay. Further mechanism was explored that the transcription factor HNF1A regulated the expression of EPS8 and downstream signaling pathways by directly binding to the promoter region of EPS8. Our comprehensive analysis of clinical samples in this study showed that upregulated expression of HNF1A was associated with poor survival in GBM patients. Further, we found that knockdown of HNF1A markedly suppressed the malignant phenotype of GBM cells in vivo and in vitro as well as promoted apoptosis of tumor cells, which was reversed by upregulation of HNF1A. Mechanistically, HNF1A could significantly activate PI3K/AKT signaling pathway by specifically binding to the promoter regions of EPS8. Moreover, overexpression of EPS8 was able to reverse the apoptosis of tumor cells caused by HNF1A knockdown, thereby exacerbating the GBM progression. Correctively, our study has clarified the explicit mechanism by which HNF1A promotes GBM malignancy and provides a new therapeutic target for further clinical application.
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Glioblastoma , Proteínas Proto-Oncogénicas c-akt , Animales , Ratones , Humanos , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Glioblastoma/genética , Glioblastoma/patología , Ratones Desnudos , Proliferación Celular , Línea Celular Tumoral , Transducción de Señal , Factores de Transcripción/metabolismo , Regulación Neoplásica de la Expresión Génica , Factor Nuclear 1-alfa del Hepatocito/genética , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismoRESUMEN
OBJECTIVES: This study aimed to systematize the Zhuang medicinal herbs of Ardisia (ZMHA) in China, to clarify the traditional use in Zhuang medicine and the dynamics of international research on phytochemistry, pharmacology, clinical application, and toxicity. KEY FINDINGS: There are 25 species of ZMHA, approximately 938 compounds from the different part, including triterpenoids, phenolics, volatile oils, etc. Pharmacological activity studies have also shown that this genus has anti-tumour, anti-inflammatory, anti-oxidant, anti-bacterial, anti-microbial, etc., and significant effects on respiratory, digestive, urinary, and musculoskeletal system diseases without toxic side effects. SUMMARY: The Ardisia has a medicinal history of nearly a thousand years, mainly for treating diseases of the injuries, musculoskeletal, and symptomatic system in Zhuang medicine. Some plants, such as A. crenata, A. gigantifolia, and A. japonica, are also commonly used in folk Zhuang medicine formulas, to treat musculoskeletal, injury, respiratory, and urinate systems disease. These diseases are related to inflammation. These could provide a new direction for future new drug development research. Therefore, species identification and resource investigation should be strengthened, and conducted in vitro mechanism, in vivo pharmacology, clinical efficacy, and toxicology studies and establish a perfect quality standard system.
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Ardisia , Plantas Medicinales , Plantas Medicinales/química , Etnobotánica , Medicina Tradicional , China , Etnofarmacología , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , FitoterapiaRESUMEN
Protein ubiquitination is a common post-translational modification and a critical mechanism for regulating protein stability. This study aimed to explore the role and potential molecular mechanism of ubiquitin-specific peptidase 38 (USP38) in the progression of lung adenocarcinoma (LUAD). USP38 expression was significantly higher in patients with LUAD than in their counterparts, and higher USP38 expression was closely associated with a worse prognosis. USP38 silencing suppresses the proliferation of LUAD cells in vitro and impedes the tumorigenic activity of cells in xenograft mouse models in vivo. Further, we found that USP38 affected the protein stability of transcription factor Krüppel-like factors 5 (KLF5) by inhibiting its degradation. Subsequent mechanistic investigations showed that the N-terminal of USP38 (residues 1-400aa) interacted with residues 1-200aa of KLF5, thereby stabilizing the KLF5 protein by deubiquitination. Moreover, we found that PIAS1-mediated SUMOylation of USP38 was promoted, whereas SENP2-mediated de-SUMOylation of USP38 suppressed the deubiquitination effects of USP38 on KLF5. Additionally, our results demonstrated that KLF5 overexpression restored the suppression of the malignant properties of LUAD cells by USP38 knockdown. SUMOylation of USP38 enhances the deubiquitination and stability of KLF5, thereby augmenting the malignant progression of LUAD.
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Adenocarcinoma del Pulmón , Factores de Transcripción , Animales , Humanos , Ratones , Adenocarcinoma del Pulmón/genética , Proliferación Celular/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción/metabolismo , Proteasas Ubiquitina-Específicas/genética , Proteasas Ubiquitina-Específicas/metabolismo , UbiquitinaciónRESUMEN
To explore how traits determine demographic performance is an important goal of plant community ecology in explaining the assembly and dynamics of ecological communities. However, whether the prediction of individual-level trait data is more precise compared to species average trait data is questioned. Here, we analyzed the growth and trait data for 11 species collected from October 2018 to October 2020 in a temperate forest, Donglingshan, Beijing. To quantify the relationships between traits and growth rate, we conducted linear regression models at both the species and individual levels, as well as developed structural equation models at both levels. We found there was a clear difference in growth between the warm and cold seasons, with tree growth mainly concentrated in the warm season. Growth rate was positively correlated with the specific leaf area, while negatively correlated with leaf thickness and wood density without considering environmental information. Adding important contextual information in the analysis of species-level structural equation modeling, growth rates were positively correlated with specific leaf area and leaf thickness. However, in the individual-level, there was a negative correlation between growth rate and wood density. Our study showed that individual-level trait data have better predictions for individual growth than species-level data. When we use multiple traits and establish links between traits and tree size, we generated strong predictive relationships between traits and growth rates. Furthermore, our study highlighted that the importance of incorporating topographical factors and considering different seasons to assess the relationship between tree growth and functional traits.
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Bosques , Árboles , Ecosistema , Madera/química , Fenotipo , Hojas de la Planta/químicaRESUMEN
Investigating the role of ubiquitin-specific peptidase 10 (USP10) in triple-negative breast cancer (TNBC). Analyzed USP10 expression levels in tumors using public databases. Detected USP10 mRNA and protein levels in cell lines. Examined USP10 expression in tumor tissues from breast cancer patients. Conducted USP10 knockdown experiments and analyzed changes in cell proliferation and metastasis. Confirmed protein-protein interactions with USP10 through mass spectrometry, Co-IP, and fluorescence experiments. Assessed impact of USP10 on transcription factor 4 (TCF4) ubiquitination and validated TCF4's influence on TNBC cells. We initially identified a pronounced overexpression of USP10 across multiple tumor types, including TNBC. Subsequently, we observed a conspicuous upregulation of USP10 expression levels in breast cancer cell lines compared to normal breast epithelial cells. However, upon subsequent depletion of USP10 within cellular contexts, we noted a substantial attenuation of malignant proliferation and metastatic potential in TNBC cells. In subsequent experimental analyses, we elucidated the physical interaction between USP10 and the transcription factor TCF4, whereby USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC. Collectively, this study demonstrates that USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC.
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Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/metabolismo , Factor de Transcripción 4/genética , Factor de Transcripción 4/metabolismo , Ubiquitinación , Células Epiteliales/metabolismo , Regulación hacia Arriba , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Ubiquitina Tiolesterasa/genéticaRESUMEN
The connections between the primary and secondary growth of trees allows better understanding of the dynamics of carbon sequestration in forest ecosystems. The relationship between primary and secondary growth of trees could change due to the diverging responses of meristems to climate warming. In this study, the bud phenology and radial growth dynamics of Qinghai spruce (Picea crassifolia) in arid and semi-arid areas of China in 2019 and 2020 were weekly monitored to analyze their response to different weather conditions and their links with carbon sink. Xylem anatomical traits (i.e. lumen radial diameter and cell wall thickness) were quantified along cell radial files after the end of xylem lignification to calculate the early-to-latewood transition date. Winter and early spring (January-March) were warmer in 2020 with a colder April compared with 2019. Precipitation in April-June was lower in 2020 than in 2019. In 2019, bud phenology occurred earlier, while the onset of xylem formation and the early-to-latewood transition date were delayed. The duration from the beginning of split bud and exposed shoot to the early-to-latewood transition date was positively correlated with the radial width of earlywood (accounting for ~80% of xylem width) and total xylem width. The longer duration of xylem cell division did not increase xylem cell production and radial width. Moreover, the duration from bud burst to the early-to-latewood transition date in 2020 was negatively linked with early phloem cell production as compared with 2019. Our findings suggest that warm conditions in winter and early spring promote the xylogenesis of Qinghai spruce, but might delay bud burst. However, the xylem width increments largely depend on the duration from bud burst to the start of latewood cell division rather than on the earlier xylogenesis and longer duration of xylem cell differentiation induced by warm conditions.
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Picea , Madera , Ecosistema , Xilema , Clima , Estaciones del Año , ÁrbolesRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Ardisia gigantifolia Stapf, known as Zou-ma-tai (in Chinese), is a traditional folk medicine, which was commonly used by Dong, Jing, Li, Maonan, Miao, Mulam, Yao, and Zhuang people. The main use of A. gigantifolia is the treatment of rheumatoid arthritis, gouty arthritis, fractures, osteoproliferation, traumatic injuries, gynecological, and neurological diseases. Current studies have shown that the plant has various bioactive components, especially gigantifolinol, which has anti-tumor, anti-inflammatory, anti-tuberculosis, and neuroprotective activities. However, to date, few reviews have been made to summarize A. gigantifolia's related studies. AIMS OF THE REVIEW: This review aimed to summarize the traditional use, phytochemistry, pharmacology, clinical applications, and toxicity of A. gigantifolia, which expect to provide theoretical support for future utilization and highlight the further investigation of this vital plant. MATERIALS AND METHODS: The information related to A. gigantifolia were collated by surveying the traditional medicine books, ethnomedicinal publications, and searching academic resource databases including Web of Science, SciFinder, Springer Link, Pub Med, Science Direct, CNKI, and CQVIP database. RESULTS: A. gigantifolia has been used as a traditional folk medicine for more than 400 years in China. Different parts of the plant, including the aerial part, root, rhizome, and leaf, are mainly used as herbal medicine to treat rheumatoid arthritis, traumatic injuries, gynecological, etc. Currently, 165 compounds have been identified from the plant, including triterpenes, phenolics, coumarins, quinones, volatile oil, and sterols, 137 of which were identified from the rhizome parts. Pharmacological research showed that A. gigantifolia has various bioactivities, such as anti-tumor, anti-inflammatory, anti-oxidant, anti-thrombus, anti-tuberculosis, cough expectorant, and neuroprotective activities. Clinical studies have shown that the plant has no toxic side effects. In vivo administration at the maximum dose was not lethal, indicating the plant's safety. CONCLUSION: To date, most bioactive compounds are identified from the rhizomes of A. gigantifolia, which pharmacological activity and clinical observational studies have validated the plant's traditional use as a treatment for rheumatoid arthritis. It would be helpful to verify the mechanism of some components in vivo, such as gigantifolinol. Moreover, the plant's triterpenoid saponins demonstrated valid anti-tumor effects, especially the AG4 and AG36 compounds, which were shown to have anti-breast cancer effects both in vitro and in vivo. Further research on these components, including molecular mechanisms and in vivo metabolic regulation, needs to be confirmed.
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Ardisia , Primulaceae , Humanos , Etnobotánica , Fitoterapia , Etnofarmacología , Extractos Vegetales/farmacología , Fitoquímicos/uso terapéutico , Fitoquímicos/toxicidadRESUMEN
Litter decomposition is the main process that affects nutrient cycling and carbon budgets in mixed forests. However, knowledge of the response of the soil microbial processes to the mixed-litter decomposition of fresh leaf, semi-decomposed leaf and fine root is limited. Thus, a laboratory microcosm experiment was performed to explore the mixed-litter effects of fresh leaf, semi-decomposed leaf and fine root on the soil enzyme activity and microbial community in an evergreen broadleaf karst forest in Southwest China. Fresh leaf litter, semi-decomposed litter and fine root in the Parakmeria nitida and Dayaoshania cotinifolia forests, which are unique protective species and dominant species in the evergreen broadleaf forest, were decomposed alone and in all possible combinations, respectively. Our results showed that the mass loss of fresh leaf litter in three mixed-litter treatment was significantly higher than that in two mixed-litter treatment in the P. nitida and D. cotinifolia forests. Mass loss of fine root in the single litter treatment was significantly lower in the P. nitida forest and higher in the D. cotinifolia forest compared to that in the other litter treatments. There were insignificant differences in the activities of ß-glucosidase (BG) and leucine aminopeptidase (LAP) between control and mixed-litter treatment in the P. nitida forest and between control and single litter treatment in the D. cotinifolia forest. The N-acetyl-ß-D-glucosaminidase (NAG) activity was significantly increased by the single litter decomposition of fresh leaf and fine root and three mixed-litter decomposition in the P. nitida and D. cotinifolia forests. The activity of acid phospomonoesterase (AP) in the decomposition of fresh leaf litter was lower in the P. nitida forest and higher in the D. cotinifolia forest compared to that in control. The most dominant soil bacteria were Proteobacteria in the P. nitida forest and were Actinobacteria and Proteobacteria in the D. cotinifolia forest. Shannon, Chao1, ACE and PD indexes in the mixed-litter decomposition of fresh leaf and semi-decomposition litter were higher than that in control in P. nitida forest. There were insignificant differences in observed species and indexes of Chao1, ACE and PD between litter treatments in the D. cotinifolia forest. Richness of mixed-litter significantly affected mass loss, soil enzyme activity and microbial diversity in the P. nitida forest. Litter N concentration and the presence of fresh leaf litter were significantly correlated with the mass loss and soil enzyme activity in the P. nitida and D. cotinifolia forests. These results indicated that the presence of fresh leaf litter showed a non-negligible influence on mixed-litter decomposition and soil enzyme activity, which might be partly explained by litter initial quality in the P. nitida and D. cotinifolia forests.
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TNBC is a malignant tumor that easily relapses and metastasizes, with a poor prognosis in women. Ubiquitination plays a key role in promoting the tumor process. In various tumors, TRIM65 can affect malignant biological tumor behavior by ubiquitination of related proteins. We aimed to investigate TRIM65 expression in TNBC and whether it promotes malignant biological behavior in TNBC cells using Cell Counting Kit-8, colony formation, and transwell assays. Mechanically, we confirmed that TRIM65 promoted TNBC invasion and metastasis by ubiquitination of LATS1 protein through Co-IP, CHX, and endogenous ubiquitination experiments. The expression of TRIM65 was abnormally high and accelerated the proliferation, invasion, and migration of MDA-MB-231 and MDA-MB-453 cells. In vivo animal experiments also revealed that TRIM65 accelerated TNBC cell proliferation. Mechanistically, TRIM65 degraded LATS1 protein expression through ubiquitination in the Co-IP, CHX, and endogenous ubiquitination experiments. Rescue assays confirmed that TRIM65 degraded LATS1 protein expression, accelerating the proliferation, invasion, and migration ability of TNBC cells. Our results show that TRIM65 is upregulated in TNBC, and TRIM65 degrades LATS1 protein expression through ubiquitination and promotes malignant biological behavior in TNBC cells. TRIM65 may play an important role as a new oncogene in TNBC.
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Proteínas Serina-Treonina Quinasas , Proteínas de Motivos Tripartitos , Neoplasias de la Mama Triple Negativas , Animales , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Recurrencia Local de Neoplasia , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Motivos Tripartitos/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Ubiquitina-Proteína LigasasRESUMEN
Background: Glioma is a prevalent primary brain cancer with high invasiveness and typical local diffuse infiltration. Alternative splicing (AS), as a pervasive transcriptional regulatory mechanism, amplifies the coding capacity of the genome and promotes the progression of malignancies. This study was aimed at identifying AS events and novel biomarkers associated with survival for glioma. Methods: RNA splicing patterns were collected from The Cancer Genome Atlas SpliceSeq database, followed by calculating the percentage of splicing index. Expression profiles and related clinical information of glioma were integrated based on the UCSC Xena database. The AS events in glioma were further analyzed, and glioma prognosis-related splicing factors were identified with the use of bioinformatics analysis and laboratory techniques. Further immune infiltration analysis was performed. Results: Altogether, 9028 AS events were discovered. Upon univariate Cox analysis, 425 AS events were found to be related to the survival of patients with glioma, and 42 AS events were further screened to construct the final prognostic model (area under the curve = 0.974). Additionally, decreased expression of the splicing factors including Neuro-Oncological Ventral Antigen 1 (NOVA1), heterogeneous nuclear ribonucleoprotein C (HNRNPC), heterogeneous nuclear ribonucleoprotein L-like protein (HNRNPLL), and RNA-Binding Motif Protein 4 (RBM4) contributed to the poor survival in glioma. The immune infiltration analysis demonstrated that AS events were related to the proportion of immune cells infiltrating in glioma. Conclusions: It is of great value for comprehensive consideration of AS events, splicing networks, and related molecular subtype clusters in revealing the underlying mechanism and immune microenvironment remodeling for glioma, which provides clues for the further verification of related therapeutic targets.
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Empalme Alternativo , Glioma , Biomarcadores de Tumor/genética , Análisis de Datos , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Glioma/genética , Humanos , Pronóstico , Factores de Empalme de ARN/genética , Proteínas de Unión al ARN/genética , Microambiente Tumoral/genéticaRESUMEN
BACKGROUND: Triple-negative breast cancer (TNBC) is a highly malignant breast cancer subtype with a poor prognosis. The cell cycle regulator cyclin A2 (CCNA2) plays a role in tumor development. Herein, we explored the role of CCNA2 in TNBC. METHODS: We analyzed CCNA2 expression in 15 pairs of TNBC and adjacent tissues and assessed the relationship between CCNA2 expression using the tissue microarray cohort. Furthermore, we used two TNBC cohort datasets to analyze the correlation between CCNA2 and E2F transcription factor 1 (E2F1) and a luciferase reporter to explore their association. Through rescue experiments, we analyzed the effects of E2F1 knockdown on CCNA2 expression and cellular behavior. RESULTS: We found that CCNA2 expression in TNBC was significantly higher than that in adjacent tissues with similar observations in MDA-MB-231 and MDA-MB-468 cells. E2F1 was highly correlated with CCNA2 as observed through bioinformatics analysis (R= 0.80, P< 0.001) and through TNBC tissue verification analysis (R= 0.53, P< 0.001). We determined that E2F1 binds the +677 position within the CCNA2 promoter. Moreover, CCNA2 overexpression increased cell proliferation, invasion, and migration owing to E2F1 upregulation in TNBC. CONCLUSION: Our data indicate that E2F1 promotes TNBC proliferation and invasion by upregulating CCNA2 expression. E2F1 and CCNA2 are potential candidates that may be targeted for effective TNBC treatment.
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Neoplasias de la Mama Triple Negativas , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Ciclina A2/metabolismo , Factor de Transcripción E2F1/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias de la Mama Triple Negativas/patología , Regulación hacia ArribaRESUMEN
We provide a corrected equation of our previous publication [Opt. Express24, 19760 (2016)10.1364/OE.24.019760].
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BACKGROUND: It has been proved that lncRNAs could function as CeRNA for miRNAs in tumor growth and metastasis for cervical cancer. This paper aims to identify the role of LINC02381 in cervical cancer cells. MATERIALS AND METHODS: RT-qPCR was utilized to measure the expression levels of LINC02381 in cervical cancer tissues and cells. MTT, colony formation assay, transwell assay, RT-qPCR, and Western blotting were performed to investigate the roles of LINC02381 in cervical cancer cells. RegRNA 2.0 was used to predict the miRNA-binding sites of LINC02381. Luciferase reporter assay and RT-qPCR were employed to confirm the sponging effect between miR-133b and LINC02381. RESULTS: This study showed that LINC02381 was up-regulated in cervical cancer cells and acted as an oncogene in the development of cervical cancer. LINC02381 promoted cell viability and metastasis via sponging miR-133b. Moreover, miR-133b could target its downstream mediator of RhoA and inhibit its expression. CONCLUSION: Overall, our results indicated that LINC02381 functions as an oncogene in cervical cancer and could serve as a novel target for cervical cancer therapies in the future.
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The relationship between plants and the environment is a core area of research in ecology. Owing to differences in plant sensitivity to the environment at different life history stages, the adaptive strategies of plants are a cumulative result of both their life history and environment. Previous research on plant adaptation strategies has focused on adult plants, neglecting saplings or seedlings, which are more sensitive to the environment and largely affect the growth strategy of subsequent life stages. We compared leaf N and P stoichiometric traits of the seedlings, saplings, and adult trees of Acer mono Maxim and different altitudes and found significant linear trends for both life history stages and altitude. Leaf N and P content by unit mass were greatly affected by environmental change, and the leaf N and P content by unit area varied greatly by life history stage. Acer mono leaf N-P utilization showed a significant allometric growth trend in all life history stages and at low altitudes. The adult stage had higher N-use efficiency than the seedling stage and exhibited an isometric growth trend at high altitudes. The N-P utilization strategies of A. mono leaves are affected by changing environmental conditions, but their response is further dependent upon the life history stage of the plant. Thus, this study provides novel insights into the nutrient use strategies of A. mono and how they respond to the environmental temperature, soil moisture content along altitude and how these changes differ among different life history stages, which further provide the scientific basis for the study of plant nutrient utilization strategy on regional scale.
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Magnetic carboxyl functional nanoporous polymer (MCFNP) was chemically fabricated by incorporation of magnetic Fe3O4 precursor into the carboxyl functional nanoporous polymer (CFNP). The as-synthesized MCFNP was characterized and used as an adsorbent for rapid adsorption removal of methylene blue (MB) from wastewater. Several experimental parameters affecting the adsorption efficiency were investigated including initial pH, adsorbent dosage, initial MB concentration, contact time and temperature. The adsorption behavior of MCFNP displayed that adsorption kinetics and isotherms could be well fitted to the pseudo-second-order and Langmuir models, respectively. The experimental results showed that MCFNP was an effective adsorbent with a maximum adsorption capacity of 57.74 mg g-1 for MB at 298 K. The negative free energy (ΔG) and positive enthalpy change (ΔH) confirmed that the adsorption reaction was a spontaneous and endothermic process. In addition, ethanol was used as an effective extractant for the regeneration of MCFNP, and the adsorption efficiency could remain 80% after the ninth regeneration cycle.
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High stability single- and dual-wavelength compound cavity erbium-doped fiber lasers (EDFLs) with ultra-narrow linewidth, high optical signal to noise ratio (OSNR) and widely tunable range are demonstrated. Different from using traditional cascaded Type-1/Type-2 fiber rings as secondary cavities, we nest a Type-1 ring inside a Type-2 ring to form a passive subring cavity to achieve single-longitudinal-mode (SLM) lasing with ultra-narrow linewidth for the first time. We also show that the SLM lasing stability can be further improved by inserting a length of polarization maintaining fiber in the Type-2 ring. Using a uniform fiber Bragg grating (FBG) and two superimposed FBGs as mode restricting elements, respectively, we obtain a single-wavelength EDFL with a linewidth as narrow as 715 Hz and an OSNR as high as 73 dB, and a dual-wavelength EDFL with linewidths less than 1 kHz and OSNRs higher than 68 dB for both lasing wavelengths. Finally, by employing a novel self-designed strain adjustment device capable of applying both the compression and tension forces to the FBGs for wavelength tuning, we achieve the tuning range larger than 10 nm for both of the EDFLs.
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MOTIVATION: A series of Eu2+ (0.0025≤ × ≤0.025) activated Sr2SiO4:xEu2+ (SSO:xEu2+) phosphors were synthesized via a sol-gel method. The phosphors were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The differences between α' and ß phase of SSO in the density of states and energy band gap were investigated. RESULTS: The energy gap of α'-SSO and ß-SSO are 4.489 and 4.106 eV, respectively. While, two samples showed similar total and partial densities of states. Under the excitation by the ultra violet (UV) light (365 nm), the SSO:xEu2+ phosphor exhibited a green emission band from 400 to 700 nm, which was corresponding to the transition of 5d â 4f of Eu2+ ions. Two emission peaks at 464 and 532 nm could be obtained through Gauss fitting curves. The ratio of the blue to green emission peak decreased with the Eu2+ concentration and the peaks shifted regularly with it. The thermal quenching property was investigated and its activation energy was calculated. The results indicated that this phosphor could be a candidate of green phosphor for UV-based light-emitting diodes (LEDs).
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Europio/química , Luminiscencia , Sustancias Luminiscentes , Ácido Silícico/química , Estroncio/química , Sustancias Luminiscentes/síntesis química , Sustancias Luminiscentes/química , Relación Estructura-Actividad , Rayos Ultravioleta , Difracción de Rayos XRESUMEN
Eu3+ ions doped Sr3Al2O6 phosphors were successfully synthesized via a hydrothermal method. The precursor was prepared by low temperature hydrothermal method using ammonia as both alkaline source and precipitator. Then the final product was obtained by high temperature sintering. In addition, the structures, morphologies, and luminescent properties of as-prepared products were thoroughly characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fluorescence spectroscopy (PL). XRD shown a single phase Sr3Al2O6 prepared by a facile hydrothermal method at 250 °C for 10 h. In the PL spectra of as-prepared samples, the optimal value of Eu3+ concentration is 2 mol%. From the fluorescent spectra, the emission peaks of Sr3Al2O6: Eul+ phosphors are centered at around 591 nm, and the excitation peaks are centered at around 233 nm, 323 nm, 394 nm, and 468 nm, respectively, which were assigned to the characteristic transition of Eu3+ ions. The influence of ammonia, and the synthesis temperature on the luminescent properties of Sr3Al206: Eu3+ phosphors were studied in detail. The alkaline earth aluminates luminescent materials activated by rare earth ions have good prospects in the field of new-generation light sources.
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BACKGROUND MicroRNAs (miRNAs) are responsible for regulating proliferation, differentiation, apoptosis, invasion, and metastasis in tumor cells. miRNA-506 is abnormally expressed in multiple tumors, indicating that it might be oncogenic or tumor-suppressive. However, little is known about the association between miRNA-506 expression and esophageal squamous cell carcinoma (ESCC). MATERIAL AND METHODS We examined the expression of miRNA-506 in the plasma of ESCC patients using quantitative real-time polymerase chain reaction (qRT-PCR) to determine the association between miRNA-506 expression and clinicopathological features of ESCC. ROC curves were produced for ESCC diagnosis by plasma miRNA-506 and the area under curve was calculated to explore its diagnostic value. RESULTS Average miRNA-506 expression levels were remarkably higher in the plasma of ESCC patients than in healthy volunteers (P<0.001). The expression of miRNA-506 in the plasma was closely associated with lymph node status (P=0.004), TNM stage (P=0.031), and tumor length (P<0.001). According to ROC curves, the area under the curve for plasma miRNA-506 was 0.835, indicating statistical significance for ESCC diagnosis by plasma miRNA-506 (P<0.001). Kaplan-Meier analysis showed that patients with high miRNA-506 expression had significantly shorter survival time than those with low miRNA-506 expression. Cox regression analysis demonstrated that T stage, N stage, tumor length, and miRNA-506 expression levels were significantly correlated with prognosis in ESCC patients. CONCLUSIONS miRNA-506 can serve as an important molecular marker for diagnosis and prognostic prediction of ESCC.