Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 94
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Brief Bioinform ; 24(3)2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37114659

RESUMEN

Cyclic AMP receptor proteins (CRPs) are important transcription regulators in many species. The prediction of CRP-binding sites was mainly based on position-weighted matrixes (PWMs). Traditional prediction methods only considered known binding motifs, and their ability to discover inflexible binding patterns was limited. Thus, a novel CRP-binding site prediction model called CRPBSFinder was developed in this research, which combined the hidden Markov model, knowledge-based PWMs and structure-based binding affinity matrixes. We trained this model using validated CRP-binding data from Escherichia coli and evaluated it with computational and experimental methods. The result shows that the model not only can provide higher prediction performance than a classic method but also quantitatively indicates the binding affinity of transcription factor binding sites by prediction scores. The prediction result included not only the most knowns regulated genes but also 1089 novel CRP-regulated genes. The major regulatory roles of CRPs were divided into four classes: carbohydrate metabolism, organic acid metabolism, nitrogen compound metabolism and cellular transport. Several novel functions were also discovered, including heterocycle metabolic and response to stimulus. Based on the functional similarity of homologous CRPs, we applied the model to 35 other species. The prediction tool and the prediction results are online and are available at: https://awi.cuhk.edu.cn/∼CRPBSFinder.


Asunto(s)
Proteína Receptora de AMP Cíclico , Proteínas de Escherichia coli , Proteína Receptora de AMP Cíclico/genética , Proteína Receptora de AMP Cíclico/química , Proteína Receptora de AMP Cíclico/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Sitios de Unión/genética , Unión Proteica/genética
2.
Inorg Chem ; 63(21): 9720-9725, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38757704

RESUMEN

High-performance nonlinear-optical (NLO) crystals need to simultaneously meet multiple basic and conflicting performance requirements. Here, by using a partial chemical substitution strategy, the first noncentrosymmetric (NCS) PbBeB2O5 crystal with a BeB2O8 group was synthesized, exhibiting a two-dimensional [BeB2O5]∞ layer constructed by interconnecting BeB2O8 groups and bridged PbO4 with an active lone pair. The crystal shows a promising UV NLO functional feature, including a strong SHG effect of 3.5 × KDP (KH2PO4), large birefringence realizing phase matchability in the whole transparency region from 246 to 2500 nm, a short UV absorption edge of 246 nm, and single-crystal easy growth. Remarkably, theoretical studies reveal that the BeB2O8 group has high nonlinear activity, which could stimulate the discovery of a series of excellent NLO beryllium borates.

3.
Nucleic Acids Res ; 50(D1): D93-D101, 2022 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-34850139

RESUMEN

Circular RNAs (circRNAs), which are single-stranded RNA molecules that have individually formed into a covalently closed continuous loop, act as sponges of microRNAs to regulate transcription and translation. CircRNAs are important molecules in the field of cancer diagnosis, as growing evidence suggests that they are closely related to pathological cancer features. Therefore, they have high potential for clinical use as novel cancer biomarkers. In this article, we present our updates to CircNet (version 2.0), into which circRNAs from circAtlas and MiOncoCirc, and novel circRNAs from The Cancer Genome Atlas database have been integrated. In total, 2732 samples from 37 types of cancers were integrated into CircNet 2.0 and analyzed using several of the most reliable circRNA detection algorithms. Furthermore, target miRNAs were predicted from the full-length circRNA sequence using three reliable tools (PITA, miRanda and TargetScan). Additionally, 384 897 experimentally verified miRNA-target interactions from miRTarBase were integrated into our database to facilitate the construction of high-quality circRNA-miRNA-gene regulatory networks. These improvements, along with the user-friendly interactive web interface for data presentation, search, and visualization, showcase the updated CircNet database as a powerful, experimentally validated resource, for providing strong data support in the biomedical fields. CircNet 2.0 is currently accessible at https://awi.cuhk.edu.cn/∼CircNet.


Asunto(s)
Biomarcadores de Tumor/genética , Bases de Datos Genéticas , Neoplasias/genética , ARN Circular/genética , Perfilación de la Expresión Génica , Redes Reguladoras de Genes/genética , Humanos , ARN Circular/clasificación
4.
Nucleic Acids Res ; 50(D1): D222-D230, 2022 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-34850920

RESUMEN

MicroRNAs (miRNAs) are noncoding RNAs with 18-26 nucleotides; they pair with target mRNAs to regulate gene expression and produce significant changes in various physiological and pathological processes. In recent years, the interaction between miRNAs and their target genes has become one of the mainstream directions for drug development. As a large-scale biological database that mainly provides miRNA-target interactions (MTIs) verified by biological experiments, miRTarBase has undergone five revisions and enhancements. The database has accumulated >2 200 449 verified MTIs from 13 389 manually curated articles and CLIP-seq data. An optimized scoring system is adopted to enhance this update's critical recognition of MTI-related articles and corresponding disease information. In addition, single-nucleotide polymorphisms and disease-related variants related to the binding efficiency of miRNA and target were characterized in miRNAs and gene 3' untranslated regions. miRNA expression profiles across extracellular vesicles, blood and different tissues, including exosomal miRNAs and tissue-specific miRNAs, were integrated to explore miRNA functions and biomarkers. For the user interface, we have classified attributes, including RNA expression, specific interaction, protein expression and biological function, for various validation experiments related to the role of miRNA. We also used seed sequence information to evaluate the binding sites of miRNA. In summary, these enhancements render miRTarBase as one of the most research-amicable MTI databases that contain comprehensive and experimentally verified annotations. The newly updated version of miRTarBase is now available at https://miRTarBase.cuhk.edu.cn/.


Asunto(s)
Regiones no Traducidas 3' , Bases de Datos de Ácidos Nucleicos , Redes Reguladoras de Genes , MicroARNs/genética , Neoplasias/genética , ARN no Traducido/genética , Animales , Sitios de Unión , Biomarcadores/metabolismo , Minería de Datos/estadística & datos numéricos , Exosomas/química , Exosomas/metabolismo , Regulación de la Expresión Génica , Humanos , Internet , Ratones , MicroARNs/clasificación , MicroARNs/metabolismo , Anotación de Secuencia Molecular , Neoplasias/metabolismo , Neoplasias/patología , Polimorfismo de Nucleótido Simple , ARN no Traducido/clasificación , ARN no Traducido/metabolismo , Células Tumorales Cultivadas , Interfaz Usuario-Computador
5.
Int J Mol Sci ; 25(11)2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38891842

RESUMEN

Time-series experiments are crucial for understanding the transient and dynamic nature of biological phenomena. These experiments, leveraging advanced classification and clustering algorithms, allow for a deep dive into the cellular processes. However, while these approaches effectively identify patterns and trends within data, they often need to improve in elucidating the causal mechanisms behind these changes. Building on this foundation, our study introduces a novel algorithm for temporal causal signaling modeling, integrating established knowledge networks with sequential gene expression data to elucidate signal transduction pathways over time. Focusing on Escherichia coli's (E. coli) aerobic to anaerobic transition (AAT), this research marks a significant leap in understanding the organism's metabolic shifts. By applying our algorithm to a comprehensive E. coli regulatory network and a time-series microarray dataset, we constructed the cross-time point core signaling and regulatory processes of E. coli's AAT. Through gene expression analysis, we validated the primary regulatory interactions governing this process. We identified a novel regulatory scheme wherein environmentally responsive genes, soxR and oxyR, activate fur, modulating the nitrogen metabolism regulators fnr and nac. This regulatory cascade controls the stress regulators ompR and lrhA, ultimately affecting the cell motility gene flhD, unveiling a novel regulatory axis that elucidates the complex regulatory dynamics during the AAT process. Our approach, merging empirical data with prior knowledge, represents a significant advance in modeling cellular signaling processes, offering a deeper understanding of microbial physiology and its applications in biotechnology.


Asunto(s)
Algoritmos , Proteínas de Escherichia coli , Escherichia coli , Regulación Bacteriana de la Expresión Génica , Redes Reguladoras de Genes , Escherichia coli/genética , Escherichia coli/metabolismo , Anaerobiosis/genética , Aerobiosis , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Transducción de Señal/genética , Modelos Biológicos , Perfilación de la Expresión Génica/métodos
6.
J Am Chem Soc ; 145(41): 22577-22583, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37812140

RESUMEN

Atoms in special lattice sites can play a crucial role in realizing materials properties, which is long pursued but difficult to control. Herein, by adopting a stereochemically active lone-pair-containing metal substitution strategy, a nonlinear-optical (NLO) silicate crystal Li3(OH)PbSiO4 was successfully synthesized, featuring [PbSiO4]∞ layers with the perfect orientation of the stereochemically active lone-pair Pb(II) cation in the polar-axis lattice. Li3(OH)PbSiO4 overcomes the long-standing problem of silicates, that is, poor nonlinear properties because it exhibits both the largest birefringence of 0.082 and the largest phase-matchable second-harmonic-generation (SHG) efficiency of 21 × KDP among the known silicates. The successful polar-axis lattice substitution could offer a new direction for realizing the rational control of materials structures and properties.

7.
Gastric Cancer ; 26(4): 565-579, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37062785

RESUMEN

BACKGROUND: Gastric cancer (GC) is a cancer of the gastrointestinal tract that is highly malignant and has poor prognosis. Circular RNAs are a class of nonclassical RNA molecules that have been determined to be involved in GC malignancy in various ways. However, the underlying function and mechanism of circTDRD3 in gastric cancer remain largely unknown. METHODS: We analyzed circTDRD3 expression in databases and verified the findings in GC cell lines and tissue specimens. A series of functional gene overexpression and knockdown assays in vivo and in vitro were carried out to investigate the role of circTDRD3 in proliferation and metastasis. Here, we revealed the role of the miR-891b/ITGA2 axis by analyzing bioinformatics datasets. Furthermore, we performed dual-luciferase, fluorescence in situ hybridization, RNA pull-down, and functional rescue experiments to examine the relationships between circTDRD3 and its interacting molecules. Western blot confirmed the positive regulatory role of circTDRD3 in the AKT signaling pathway. A promoting effect of ATF4 on circTDRD3 was determined through chromatin immunoprecipitation. RESULTS: CircTDRD3 was significantly overexpressed in GC tissues compared with adjacent benign tissue, and its expression level was positively correlated with tumor volume and lymph node metastasis. CircTDRD3 promoted GC cell proliferation and migration in vitro and in vivo. Mechanistically, circTDRD3 exerted a tumor-promoting effect by regulating the miR-891b/ITGA2 axis and AKT signaling pathway in a positive feedback manner mediated by the transcription factor ATF4. CONCLUSIONS: ATF4-mediated circTDRD3 overexpression modulates the proliferation and metastasis of GC cells through the miR-891b/ITGA2 axis in a positive feedback manner.


Asunto(s)
MicroARNs , Neoplasias Gástricas , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Gástricas/patología , Hibridación Fluorescente in Situ , Transducción de Señal , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Línea Celular Tumoral , Factor de Transcripción Activador 4/genética , Factor de Transcripción Activador 4/metabolismo
8.
Nucleic Acids Res ; 49(D1): D1268-D1275, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33270889

RESUMEN

DNA methylation is an important epigenetic regulator in gene expression and has several roles in cancer and disease progression. MethHC version 2.0 (MethHC 2.0) is an integrated and web-based resource focusing on the aberrant methylomes of human diseases, specifically cancer. This paper presents an updated implementation of MethHC 2.0 by incorporating additional DNA methylomes and transcriptomes from several public repositories, including 33 human cancers, over 50 118 microarray and RNA sequencing data from TCGA and GEO, and accumulating up to 3586 manually curated data from >7000 collected published literature with experimental evidence. MethHC 2.0 has also been equipped with enhanced data annotation functionality and a user-friendly web interface for data presentation, search, and visualization. Provided features include clinical-pathological data, mutation and copy number variation, multiplicity of information (gene regions, enhancer regions, and CGI regions), and circulating tumor DNA methylation profiles, available for research such as biomarker panel design, cancer comparison, diagnosis, prognosis, therapy study and identifying potential epigenetic biomarkers. MethHC 2.0 is now available at http://awi.cuhk.edu.cn/∼MethHC.


Asunto(s)
Biomarcadores de Tumor/genética , Metilación de ADN , Bases de Datos Genéticas , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Neoplasias/genética , Biomarcadores de Tumor/metabolismo , ADN Tumoral Circulante/sangre , ADN Tumoral Circulante/genética , Variaciones en el Número de Copia de ADN , Progresión de la Enfermedad , Elementos de Facilitación Genéticos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Internet , Análisis por Micromatrices , Anotación de Secuencia Molecular , Mutación , Neoplasias/clasificación , Neoplasias/diagnóstico , Neoplasias/metabolismo , Programas Informáticos , Transcriptoma
9.
Int J Mol Sci ; 24(18)2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37762364

RESUMEN

Drug-target interactions (DTIs) are considered a crucial component of drug design and drug discovery. To date, many computational methods were developed for drug-target interactions, but they are insufficiently informative for accurately predicting DTIs due to the lack of experimentally verified negative datasets, inaccurate molecular feature representation, and ineffective DTI classifiers. Therefore, we address the limitations of randomly selecting negative DTI data from unknown drug-target pairs by establishing two experimentally validated datasets and propose a capsule network-based framework called CapBM-DTI to capture hierarchical relationships of drugs and targets, which adopts pre-trained bidirectional encoder representations from transformers (BERT) for contextual sequence feature extraction from target proteins through transfer learning and the message-passing neural network (MPNN) for the 2-D graph feature extraction of compounds to accurately and robustly identify drug-target interactions. We compared the performance of CapBM-DTI with state-of-the-art methods using four experimentally validated DTI datasets of different sizes, including human (Homo sapiens) and worm (Caenorhabditis elegans) species datasets, as well as three subsets (new compounds, new proteins, and new pairs). Our results demonstrate that the proposed model achieved robust performance and powerful generalization ability in all experiments. The case study on treating COVID-19 demonstrates the applicability of the model in virtual screening.

10.
Eur Radiol ; 32(12): 8569-8578, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35704109

RESUMEN

OBJECTIVES: To evaluate the associations of the radiological features of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with the postoperative complications and overall survival (OS) of patients undergoing laparoscopic radical gastrectomy for gastric cancer. METHODS: One hundred forty-two patients underwent laparoscopic radical gastrectomy for gastric cancer from February 2013 to May 2016. The radiological features of SAT and VAT were studied by preoperative computed tomography, and the relationships between the parameters of adipose tissues and the intraoperative and postoperative conditions and OS rate of patients were evaluated. RESULTS: A positive linear correlation was found between VAT area and operation duration, and a negative linear correlation was found between VAT density and intraoperative blood loss (p < 0.05 in both). VAT area was an independent risk factor for postoperative complications. VAT area and VAT density were independent risk factors for OS in gastric cancer. CONCLUSIONS: A high VAT area was an independent risk factor for postoperative complications of gastric cancer, whereas a low VAT area and high VAT density were independent risk factors for poor prognosis in terms of OS in gastric cancer. KEY POINTS: • A large visceral adipose tissue (VAT) area is an unfavourable factor affecting the outcomes of radical gastrectomy for gastric cancer. • Low VAT density may be more likely to cause intraoperative bleeding. • VAT area and VAT density were independent risk factors for the OS of patients with gastric cancer.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/cirugía , Grasa Subcutánea/diagnóstico por imagen , Gastrectomía , Grasa Intraabdominal/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/cirugía
11.
Inorg Chem ; 61(3): 1538-1545, 2022 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-35005905

RESUMEN

The exploration of nonlinear-/linear-optical crystal materials with high performance is an extremely difficult research project. Herein, the two new lead tellurite crystals BaPbTe2O6 and PbVTeO5F were successfully obtained through a facile hydrothermal synthesis strategy. BaPbTe2O6 lies in the noncentrosymmetric (NCS) and chiral orthorhombic space group P212121, featuring a unique ∞1[PbTe2O6] chain consisting of the PbO4 and TeO3 building units, while PbVTeO5F belonging to the centrosymmetric (CS) orthorhombic space group Pbca manifests a 2D layer made up of ∞1[PbO4F2] chains and novel [V2Te2O10F2] clusters. Further, a systematic analysis of lead tellurites finds that the coordination geometries of the Pb atom exert a considerable influence on the connection modes of Pb-O and Te-O building units. BaPbTe2O6 shows a great second-harmonic-generation (SHG) effect of ∼5× the benchmark KH2PO4 (KDP) and a large optical birefringence of 0.086 at 590 ± 3 nm. PbVTeO5F demonstrates a remarkably larger birefringence of 0.142 at 590 ± 3 nm, benefiting from the introduction of the VO5F octahedral unit. Theoretical studies reveal that the large SHG and birefringence in BaPbTe2O6 can be attributed to TeO3 and PbO4 polyhedra with active lone pairs, while the remarkably enlarged birefringence in PbVTeO5F is attributable to the highly distorted octahedral VO5F. The functional orientations of active building units may offer a practical insight into the design of the desired optical functional materials.

12.
Inorg Chem ; 61(39): 15368-15376, 2022 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-36121404

RESUMEN

Stereochemically active lone-pair (SCALP) cations are one attractive type of nonlinear optical (NLO)-active units because of their large microcosmic polarizability and anisotropy. Currently, the single and/or dual lone-pair cation-based noncentrosymmetric (NCS) oxides have been extensively investigated and verified to be one class of outstanding NLO materials. From the perspective of function optimization, the integration of three kinds of SCALP cations into one crystal may synergistically improve the NLO properties, which is greatly expected but unexplored to date. Herein, by introducing flexible metal halide bonds to guarantee the stereochemical activity and overcome the energetically favorable antiparallel arrangements of lone-pair cations, the first type of three lone-pair-cation (Pb2+, Bi3+, and Se4+)-coexisting NCS oxides PbBi(SeO3)2F (I) and Pb2Bi(SeO3)2Cl3 (II) was obtained. As expected, both compounds show outstanding NLO properties, such as the strong second-harmonic-generation signal (10.5× and 13.5 × KDP), large birefringence (0.103 and 0.186), relatively wide energy band gaps (3.75 and 3.45 eV), and good physicochemical stability. Theoretical calculations demonstrated the effect of three lone-pair-cation-based polyhedra and the halide anion on NLO properties.


Asunto(s)
Plomo , Óxidos , Anisotropía , Cationes
13.
Future Oncol ; 18(39): 4239-4349, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36651765

RESUMEN

Although gastric cancer with para-aortic lymph node (PAN) metastasis is commonly regarded as unresectable, surgeons have explored the optimal treatment for patients with PAN metastases limited to No.16a2/b1 in the past few decades. Preoperative systemic therapy combined with D2 gastrectomy plus PAN dissection may improve the prognosis of these patients. In this multicenter phase II trial, 29 gastric cancer patients with PAN metastasis limited to No.16a2/b1 will receive preoperative treatment with nab-paclitaxel, oxaliplatin, S-1 (nab-POS: nab-paclitaxel, oxaliplatin, S-1) and sintilimab followed by D2 gastrectomy plus PAN dissection; and postoperative treatment with oral S-1, intravenous sintilimab and intraperitoneal paclitaxel. The end points for the study are 3-year overall survival, 3-year disease-free survival, pathological response rate, incidence of postoperative complications and adverse events.


Stomach cancer with metastases in the para-aortic lymph nodes is usually considered inoperable. Chemotherapy combined with resection of the stomach and more extensive lymph node dissection may prolong the life of these patients. In this multicenter study, 29 stomach cancer patients with para-aortic lymph node metastases will receive preoperative treatment with nab-paclitaxel, oxaliplatin, S-1 and sintilimab, followed by resection of the stomach combined with para-aortic lymph node dissection and use of continued oral, intravenous and intraperitoneal chemotherapy. The study's end points are 3-year overall survival, 3-year disease-free survival, pathological response rate, incidence of postoperative complications and adverse events. Clinical Trial Registration: ChiCTR2200061125 (ChiCTR.org.cn).


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Escisión del Ganglio Linfático , Metástasis Linfática/patología , Oxaliplatino , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ganglios Linfáticos/patología , Gastrectomía/efectos adversos , Estudios Multicéntricos como Asunto , Ensayos Clínicos Fase II como Asunto
14.
Nucleic Acids Res ; 48(D1): D148-D154, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31647101

RESUMEN

MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18-25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA-target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA-target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , MicroARNs/metabolismo , MicroARN Circulante/metabolismo , Minería de Datos , Regulación de la Expresión Génica , ARN Mensajero/metabolismo , Interfaz Usuario-Computador
15.
Inorg Chem ; 60(15): 11214-11221, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34142821

RESUMEN

The design of material by chemical and/or crystalline modification of a classic structure model benefits not only the optimized physical properties but also the controllability and efficiency. Herein, a new nonlinear-optical (NLO) beryllium borate crystal, Sr2Pb(BeB5O10)(BO3) (SPBBO), is successfully designed and synthesized by chemical and crystalline modification of the perovskite-like K3B6O10Cl NLO crystal. SPBBO displays a 3D BeB5O103- open-framework structure composed of interconnecting BeB5O13 groups with filled cationic Sr/Pb and anionic BO3 groups, which exhibits the striking enhancement of the second-harmonic-generation (SHG) response (8 × KDP) and birefringence (0.10) compared to the parent model. Replacement of K by Sr and Pb with a lone pair and replacement of Cl by conjugated BO3 result in the synergistic conjugation of Pb with host BeB5O103- and filled BO3 groups, contributing to the striking enhancement of the SHG and birefringence. Single-crystal measurements show that SPBBO has a short UV absorption edge of 280 nm with a wide energy band gap of 4.35 eV and an outstanding laser-induced resistant behavior with a remarkably high laser-induced damage threshold of 2100 MW cm-2. The excellent properties indicate that the SPBBO crystal is a very promising UV NLO functional material.

16.
J Surg Res ; 253: 185-192, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32361613

RESUMEN

BACKGROUND: In recent years, microRNA (miRNA) is considered as a potential therapy target. To study the regulatory mechanism and therapeutic effect of miRNAs on inflammatory bowel disease (IBD), we investigated microRNAs that regulate apoptosis-related protein B cell lymphoma-2 (Bcl-2). We examined the role of miR-16 in IBD and the effect of inhibiting the expression of miR-16 on disease progression. MATERIALS AND METHODS: Dextran sulfate sodium was used to induce ulcerative colitis in mice. RNA and protein were extracted from the rectal mucosa of mice. Real-time quantitative polymerase chain reaction and Western blotting were used to detect the expression of miR-16 and Bcl-2. The effects of miR-16 on intestinal mucosal immunity were studied by real-time quantitative polymerase chain reaction, and inflammatory factors such as interleukin-1ß, interleukin-6, and tumor necrosis factor-α were detected. The weight changes, disease activity index, length of the rectal colon, and pathological score of the mice were used to evaluate the effect of inhibiting miR-16 on disease progression. Through the establishment of overexpression and low expression cell lines of miR-16, the regulation of miR-16 on Bcl-2 was studied. RESULTS: MiR-16 was overexpressed in the IBD model, whereas Bcl-2 had lower expression in the mucosa. Inhibiting expression of miR-16 significantly decreased the expression of interleukin-1ß, interleukin-6, and tumor necrosis factor-α. In mice, the weight change, disease activity index, and pathological score decreased in the experimental group, in which miR-16 was inhibited. High expression of miR-16 can inhibit Bcl-2 expression. CONCLUSIONS: MiR-16 plays a critical role in IBD via Bcl-2 and is a promising target in IBD therapy.


Asunto(s)
Colitis Ulcerosa/genética , Colon/inmunología , Mucosa Intestinal/inmunología , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Animales , Células CACO-2 , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/inmunología , Colon/patología , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Femenino , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Mucosa Intestinal/patología , Ratones , MicroARNs/antagonistas & inhibidores , MicroARNs/genética , Transducción de Señal/genética , Transducción de Señal/inmunología , Factor de Necrosis Tumoral alfa/metabolismo
17.
Inorg Chem ; 58(3): 2201-2207, 2019 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-30666876

RESUMEN

Beryllium (Be) has high ionization energy (9.32 eV) with the greatest degree of covalency in the group IIA elements, and BeO4 tetrahedra (and BeO3 triangles) with covalent character are generally presented in beryllates. An unprecedented BeO6 trigonal prism with ultralong Be-O bonds as well as a BeO4 common tetrahedron is discovered in a new deep ultraviolet crystal Li13BeBe6B9O27 (LBeBBO) with a ∞2[Be6B9O33] double-layer framework. The BeO6 unit and its bond character are verified by an isostructural crystal Li13(Mg0.45Be0.55)Be6B9O27, while the orbital theory and charge density difference further clarify the ionic character of the BeO6 unit. Phonon dispersion confirms the structural stability of LBeBBO.

18.
Phys Chem Chem Phys ; 21(30): 16486-16496, 2019 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-31322641

RESUMEN

The Wulff construction is a well-known method for studying the morphologies of nanocrystal particles. The underlying Gibbs-Wulff theorem relies on Wulff points or particle centers, which are invalid for non-centrosymmetric crystals. In this study, we extend the method of inverse Wulff construction to study surface free energies of non-centrosymmetric crystals. A nonpolar (4[combining macron]3m) and a polar crystal system (6mm) are selected to show the difficulties and constraints caused by the lack of inversion centers. In addition to analytical and numerical results, we also present a general four-parameter function to simplify calculations of surface free energies from observed micro- or nanoparticle morphologies. The results reveal that non-centrosymmetric crystal morphologies entail the surface thermodynamics of coupling polar surfaces, with certain limitations originating from the combination of geometrical shapes and crystal symmetries.

19.
Angew Chem Int Ed Engl ; 58(48): 17194-17198, 2019 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-31538687

RESUMEN

Excellent nonlinear optical materials simultaneously meet the requirements of large SHG response, phase-matching capability, wide transparency windows, considerable energy band-gap, good thermal stability and structure stability. Herein, two new promising nonlinear optical (NLO) crystals LiMII (IO3 )3 (MII =Zn and Cd) are rationally designed by the aliovalent substitution strategy from the commercialized α-LiIO3 with the perfect parallel alignment of IO3 groups. Compared with parent α-LiIO3 and related AI 2 MIV (IO3 )6 , the title compounds exhibit more stable covalent 3D structure, and overcome the racemic twinning problem of AI 2 MIV (IO3 )6 . More importantly, both compounds inherit NLO-favorable structure merits of α-LiIO3 and show larger SHG response (≈14× and ≈12×KDP), shorter absorption edge (294 and 297 nm) with wider energy band-gap (4.21 and 4.18 eV), good thermal stability (460 and 430 °C), phase-matching behaviors, wider optical transparency window and good structure stability, achieving an excellent balance of NLO properties.

20.
IUBMB Life ; 70(4): 276-290, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29500870

RESUMEN

This study was expected to reveal the regulatory effects of lncRNA UCA1 on pancreatic cancer cell progression through targeting miR-96/FOXO3. Microarray analysis was carried out on 36 cases of pancreatic cancer tissues and 16 cases of adjacent tissues among them. Expression levels of lncRNA UCA1, miR-96, and FOXO3 in pancreatic cancer tissues and cell lines were determined by qRT-PCR. Expression levels of FOXO3 protein were determined by western blot. Cell viability, cell cycle and apoptosis, cell invasion and migration were detected by CCK-8, flow cytometry, and transwell assay, respectively. The colocalization relationship between lncRNA UCA1 and miR-96 was detected by RNA FISH. Whether UCA1 could target miR-96 and whether miR-96 could target FOXO3 3'UTR were verified by dual-luciferase reporter gene assay. High expression of lncRNA UCA1 and FOXO3 and low expression of miR-96 were shown in pancreatic cancer. Inhibition of UCA1 suppressed pancreatic tumor cell proliferation, colony formation, and metastasis, while inhibition of miR-96 promoted pancreatic cancer cell progression. FOXO3 was the downstream target gene of miR-96 and showed the opposite effects. LncRNA UCA1 promoted cell proliferation, invasion, migration and inhibited cell apoptosis of pancreatic cancer through down-regulating miR-96 and up-regulating FOXO3. © 2018 IUBMB Life, 70(4):276-290, 2018.


Asunto(s)
Movimiento Celular , Proliferación Celular , Proteína Forkhead Box O3/metabolismo , MicroARNs/genética , Neoplasias Pancreáticas/patología , ARN Largo no Codificante/genética , Apoptosis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Adhesión Celular , Proteína Forkhead Box O3/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Invasividad Neoplásica , Metástasis de la Neoplasia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Pronóstico , Células Tumorales Cultivadas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA