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1.
ACS Appl Mater Interfaces ; 11(42): 38503-38509, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31556986

RESUMO

Solvothermal reaction of zinc meso-tetra(4-carboxyphenyl)porphyrin and 2,6-diaminopurine with zinc salt in DMF affords a three-dimensional bioMOF (1-α). Its infinite rod-shaped building block features an alternation of octahedral Zn4O and paddle-wheel Zn2 clusters bridged by 2,6-diaminopurines. The paddle-wheel Zn2 cluster undergoes reversible transformation with half into quasi-paddle-wheel Zn2 cluster and the other half into two tetrahedral mononuclear clusters upon release/uptake of guest molecules, resulting in a new phase 1-ß. This single-crystal to single-crystal transformation is accompanied by luminescence on/off switching, possibly associated with the structural conversion between the porphyrin-ligand-based photoactive 1-α and the porphyrin-stacking-caused non-photoactive 1-ß. Interestingly, 1-ß exhibits quick luminescence turn-on in alcohol vapor instead of other volatile organic solvents by transforming into an intermediate phase 1-γ, which shows a partial luminescence enhancing likely due to the intermittent porphyrin π-π stacking. In view of experimental results and theoretical calculations, this distinctive alcohol-vapor-induced luminescence turn-on is attributed to the coordination ability to porphyrin-bound zinc ion, molecular size, and vapor pressure, in which methanol and ethanol are particularly favored.

2.
Opt Express ; 27(17): 24481-24497, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31510336

RESUMO

Visual odometry has received a great deal of attention during the past decade. However, being fragile to rapid motion and dynamic scenarios prevents it from practical use. Here, we present PALVO by applying panoramic annular lens to visual odometry, greatly increasing the robustness to both cases. We modify the camera model for PAL and specially design the initialization process based on the essential matrix. Our method estimates the camera's poses through two-stage tracking, meanwhile builds the local map using a probabilistic mapping method based on the Bayesian framework and feature correspondence search along the epipolar curve. Several experiments are performed to verify our algorithm, demonstrating that our algorithm provides an extremely competitive performance in robustness to rapid motion and dynamic scenarios, meanwhile achieves the same level of accuracy as the state-of-the-art visual odometry.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31512996

RESUMO

BACKGROUND: Forkhead box C1 (FOXC1) is an important cancer associated gene in tumor. PPAR-γ and C/EBPα are both transcriptional regulators involved in tumor development. OBJECTIVE: We aimed to clarify the function of PPAR-γ, C/EBPα in hepatocellular carcinoma (HCC) and relationship of PPAR-γ, C/EBPα and FOXC1 in HCC. METHOD: Western blotting, immunofluorescent staining and immunohistochemistry were used to evaluate protein expression. qRT-PCR was used to assess mRNA expression. Co-IP was performed to detect the protein interaction. And ChIP and fluorescent reporter detection were used to determine the binding between protein and FOXC1 promoter. RESULTS: C/EBPα could bind to FOXC1 promoter and PPAR-γ could strengthen C/EBPα's function. Expressions of C/EBPα and PPAR-γ were both negatively related with FOXC1 in human HCC tissue. Confocal displayed that C/EBPα was co-located with FOXC1 in HepG2 cells. C/EBPα could bind to FOXC1 promoter by ChIP. Luciferase activity detection exhibited that C/EBPα could inhibit FOXC1 promoter activity, especially FOXC1 promoter from -600 to -300 was the critical binding site. Only PPAR-γ couldn't influence luciferase activity but strengthen inhibited effect of C/EBPα. Further, the Co-IP displayed that PPAR-γ could bind to C/EBPα. When C/EBPα and PPAR-γ was both high expressed, cell proliferation, migration, invasion and colony information were inhibited enormously. C/EBPα plasmid combined with or without PPAR-γ agonist MDG548 treatment exhibited a strong tumor inhibition and FOXC1 suppression in mice. CONCLUSION: Our data establish C/EBPα targeting FOXC1 as potential determinant in the HCC, which supplies a new pathway to treat HCC. However, PPAR-γ has no effect on FOXC1 expression.

5.
Sci Adv ; 5(9): eaax0365, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31555733

RESUMO

Mitochondria are highly dynamic organelles. Through a large-scale in vivo RNA interference (RNAi) screen that covered around a quarter of the Drosophila melanogaster genes (4000 genes), we identified 578 genes whose knockdown led to aberrant shapes or distributions of mitochondria. The complex analysis revealed that knockdown of the subunits of proteasomes, spliceosomes, and the electron transport chain complexes could severely affect mitochondrial morphology. The loss of Dhpr, a gene encoding an enzyme catalyzing tetrahydrobiopterin regeneration, leads to a reduction in the numbers of tyrosine hydroxylase neurons, shorter lifespan, and gradual loss of muscle integrity and climbing ability. The affected mitochondria in Dhpr mutants are swollen and have fewer cristae, probably due to lower levels of Drp1 S-nitrosylation. Overexpression of Drp1, but not of S-nitrosylation-defective Drp1, rescued Dhpr RNAi-induced mitochondrial defects. We propose that Dhpr regulates mitochondrial morphology and tissue homeostasis by modulating S-nitrosylation of Drp1.

6.
J Am Chem Soc ; 141(36): 14052-14056, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31461283

RESUMO

Diels-Alder reactions are among the most powerful synthetic transformations to construct complex natural products. Despite that increasing of enzymatic intramolecular Diels-Alder reactions have been discovered, natural intermolecular Diels-Alderases are rarely described. Here, we report an intermolecular hetero-Diels-Alder reaction in the biosynthesis of tropolonic sesquiterpenes and functionally characterize EupfF as the first fungal intermolecular hetero-Diels-Alderase. We demonstrate that EupfF catalyzed the dehydration of a hydroxymethyl-containing tropolone (5) to generate a reactive tropolone o-quinone methide (6) and might further stereoselectively control the subsequent intermolecular hetero-Diels-Alder reaction with (1E,4E,8Z)-humulenol (8) to produce enantiomerically pure neosetophomone B (1). Our results reveal the biosynthetic pathway of 1 and expand the repertoire of activities of Diels-Alder cyclases.

7.
Biochem Biophys Res Commun ; 517(4): 697-702, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31399192

RESUMO

Inflammatory responses play a critical role in left ventricular remodeling after acute myocardial infarction (AMI). NR4A3, a member of the NR4A orphan nucleus receptor family, has recently emerged as a therapeutic target for treatment of inflammation. This aim of this study is to explore the therapeutic effect of NR4A3 in cardiac remodeling post AMI. Male C57BL/6 mice were administered with lentiviral over-expression of NR4A3 (lenti-NR4A3) or empty vector (lenti-con) 7 days before coronary artery ligation. H9c2 cardiomyocytes deprived of serum were used to mimic ischemic conditions in vivo. Lenti-NR4A3 treatment significantly repressed neutrophil infiltration in the myocardium, reduced infarct size, and attenuated the reduction of left ventricular function after AMI. Furthermore, NR4A3 over-expression inhibited the NF-κB (IκB) signaling by decreasing IκBα phosphorylation and by inhibiting the translocation of p65 to the nucleus. Meanwhile, NR4A3 over-expression also increases the activity of JAK2-STAT3 signaling in mouse hearts after AMI. The inhibitory effect of NR4A3 on NF-κB activation was almost completely abolished by the JAK2 inhibitor AG490, indicating that NR4A3 prevented serum deprivation induced NF-κB activation in a STAT3 dependent manner. These findings provide novel evidence that NR4A3 could inhibit post-AMI inflammation responses via JAK2-STAT3/NF-κB signaling and may well be a therapeutic target for cardiac remodeling after AMI.

8.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2009-2014, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355553

RESUMO

Ziziphi Spinosae Semen is one of the Chinese herbal medicine being susceptible to aflatoxins contamination. To investigate the sources of aflatoxins contamination and toxigenic fungi species on Ziziphi Spinosae Semen,32 samples were collected from multiple steps during the post-harvest processing in this study. Aflatoxins in these samples were determined by immunoaffinity column and HPLC coupled with post-column photochemical derivatization. The dilution-plate method was applied to the fungi isolation. The isolated fungi strains were identified by morphological characterization and molecular approaches. The results showed that aflatoxins were detected in 28 samples from every step during the processing of Ziziphi Spinosae Semen. Three samples were detected with aflatoxin B_1 and 2 samples with both aflatoxin B_1 and total aflatoxin exceeding the limit of Chinese Pharmacopoeia. Especially the samples from the washing step,with the highest detected amounts of AFB_1 and AFs were reached 94. 79,121. 43 µg·kg~(-1),respectively. All 32 samples were contaminated by fungi. The fungal counts on the newly harvested samples were 2. 20 × 10~2 CFU·g~(-1). Moreover,it increased as tphreocessing progresses,and achieved 1. 16×10~6 CFU·g~(-1) after washing. A total of 321 isolates were identified to 17 genera. Aspergillus flavus was the main source of aflatoxins during the processing and storage of Ziziphi Spinosae Semen. One isolate of A. flavus was confirmed producing AFB_1 and AFB_2. The fungal count was significantly increased by composting,and Aspergillus was the predominant genus after shell breaking. The contamination level of aflatoxins was increased by composting and washing.


Assuntos
Aflatoxinas/análise , Fungos/isolamento & purificação , Sementes/química , Sementes/microbiologia , Ziziphus/química , Aspergillus , Cromatografia Líquida de Alta Pressão
9.
Appl Opt ; 58(14): 3938-3944, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31158213

RESUMO

For state-of-the-art optical elements in laser fusion applications, optical surfaces, especially those with residual fabrication error, are generally complex in symmetry, shape of aperture, and spatial frequency distribution. It is critical to represent the optical surface with high accuracy, efficiency, and flexibility during the stages of design, fabrication, and testing. For this purpose, in this paper, we propose that adaptive radial basis functions (ARBF) can be applied to represent the complex optical surface. As more degrees of freedom are harnessed by an adaptive algorithm, the proposed approach presents better accuracy and needs fewer basis functions than that of the classical radial basis functions. Both surfaces, with global and local variation, can be well represented by the proposed method. Furthermore, the fitting ability of ARBF is verified with the measured data from an element polished by magnetorheological finishing technology. Optimization frameworks of the shape parameters for practical use are also discussed. For good measure, spatial relevance between surface height and nodes location shows that ARBF is fairly flexible in representing complex optical surfaces.

10.
Chin J Nat Med ; 17(5): 394-400, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31171275

RESUMO

Six novel monacolin analogs, monacolins V1-V6 (1-6), together with seven known ones (7-13), were isolated from the ethyl acetate extract of red yeast rice. Their structures and absolute configurations were determined by spectroscopic methods, especially 2D NMR (1H-1HCOSY, HSQC, HMBC, and NOESY/ROESY) and CD spectroscopic analyses as well as chemical derivation. Monacolins V2 (2) and V3 (3) represent the first examples of monacolins with 3-hydroxybutyrate substitute. The anti-inflammatory inhibitory activities against the lipopolysaccharide (LPS) induced NO production in BV-2 cells as well as antioxidant activities against rat liver microsomal lipid peroxidation were evaluated.

11.
Angew Chem Int Ed Engl ; 58(26): 8898-8901, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31056810

RESUMO

A highly enantioselective synthesis of 1,4-enynes is described that proceeds through an organocatalytic reaction between propargyl alcohols and trialkenylboroxines. Our strategy relies on acid-mediated generation of the carbocationic intermediate from propargyl alcohols followed by enantioselective alkenylation with trialkenylboroxines. A range of chiral 1,4-enynes were obtained in moderate to good yields with high levels of enantioselectivity. Use of a highly acidic chiral N-triflyl phosphoramide catalyst, which has two distant Lewis basic oxygen atoms, was found to be crucial for both high reactivity and selectivity in the present reaction.

12.
Inorg Chem ; 58(12): 7667-7671, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31135139

RESUMO

An anionic microporous metal-organic framework (1), featuring a combination of mononuclear and tetranuclear zinc clusters and a mix-and-match strategy of two different types of organic ligands, has been successfully constructed via a solvothermal reaction. Its luminescence can be exclusively quenched by acetone. In situ single-crystal X-ray diffraction studies reveal the specific acetone binding sites and the existence of multiple hydrogen bonds between acetone and the framework. Together with its chemical and thermal stability, 1 has been demonstrated to be a potential luminescence probe for the rapid detection of acetone with a remarkable anti-interference and a low detection limit (1.85 ppm).

13.
J Mol Diagn ; 21(4): 677-686, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026599

RESUMO

The absence of interpretation guidelines and limited data on BRCA1/2 mutations in the Chinese population have impeded the detection of BRCA variants based on next-generation sequencing (NGS) in China. This study was performed to establish a reference system for performance evaluation of BRCA genetic testing and variant interpretation, which includes interpretation rules, reference materials (RMs), and a reference database (RD). BRCA1/2 mutations identified in cell lines and clinical cases were selected to establish RMs. All mutations were detected by NGS and validated by Sanger sequencing. Variant call format files and standard variant data sets were collected and annotated to build the RD. Participant laboratories were invited to validate this reference system. Interpretation rules for BRCA variants in the Chinese population were generated as a standard for BRCA variant interpretation. Mutational analysis demonstrated that BRCA2 mutations (55%) were more common than BRCA1 mutations (45%) in Chinese patients. Eliminating duplicates from 19,886 variants, the RD contained 750 unique BRCA mutations. Most BRCA1/2 mutations in the reference system were pathogenic or likely pathogenic (RMs, 77.5%; RD, 57%). In total, 91 novel pathogenic/likely pathogenic variants were identified in the RD. The reference system can contribute to NGS performance and high-quality interpretation to facilitate clinical decision making. It could also accelerate the development and application of BRCA mutation detection technologies in China.

14.
Angew Chem Int Ed Engl ; 58(25): 8515-8519, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-30994258

RESUMO

Porous materials that can undergo pore-structure adjustment to better accommodate specific molecules are ideal for separation and purification. Here, we report a stable microporous metal-organic framework, JNU-1, featuring one-dimensional diamond-shaped channels with a high density of open metal sites arranged on the surface for the cooperative binding of acetylene. Together with its framework flexibility and appropriate pore geometry, JNU-1 exhibits an induced-fit behavior for acetylene. The specific binding sites and continuous framework adaptation upon increased acetylene pressure are validated by molecular modeling and in situ X-ray diffraction study. This unique induced-fit behavior endows JNU-1 with an unprecedented increase in the acetylene binding affinity (adsorption enthalpy: up to 47.6 kJ mol-1 at ca. 2.0 mmol g-1 loading).

15.
Appl Opt ; 58(4): 1073-1083, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30874157

RESUMO

In the automatic detection for surface defects of optical components, the digs and dust particles exhibit similar features: point-like shape and variable intensity reflectivity. On this condition, these two types with entirely different damages are easily confused so that misjudgments will be induced. To solve this problem, a polarization-characteristics-based classification method of digs and dust particles (PCCDD) is proposed based on the polarimetric imaging technique and dark-field imaging technique. First, a dark-field imaging system equipped with a polarization state generator (PSG) and a polarization state analyzer (PSA) is employed to measure and establish normalized Mueller matrices' datasets of digs and dust particles. And by a nonlinear global search combined with a separability evaluation method, the optimal number of acquisitions and corresponding polarization measurement states of the PSG and the PSA are obtained, as well as the parameters of classification function. Then, multiple polarization images are acquired under the optimal states to extract a multidimensional feature description that relates only to the polarization characteristics of the defect; this subsequently acts as the input vector of the classifier to finally achieve the classification. This method takes full advantage of both the difference in polarization properties between digs and dust particles and the characteristic that the polarization properties of digs are relatively invariant while those of dust particles have a large variability. The classification process involves only simple matrix operations. Compared to the traditional discrimination method based on intensity images, the features obtained by this method have a higher separability. Experiments show that the classification accuracy reaches over 90%. This method can be further applied to the recognition and discrimination of other defects in the field of surface defects' detection.

16.
Org Lett ; 21(5): 1475-1479, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30762374

RESUMO

Fumiquinazolines are multicyclic peptidyl alkaloids where FAD-dependent oxidases are main tailing redox enzymes in their biosynthesis. Here, we characterized the use of an α-KG/Fe(II)-dependent dioxygenase (α-KGD) as a new strategy in Nature to increase structural complexity in fumiquinazolines biosynthesis by elucidating the concise three enzymes biosynthetic pathway of heptacyclical alanditrypinone (1). Further genome mining led to the discovery of additional gene cluster with α-KGD and trimodular NRPS as partner, which generates diverse fumiquinazolines.


Assuntos
Alcaloides/química , Oxirredutases/metabolismo , Peptídeos/metabolismo , Quinazolinas/metabolismo , Vias Biossintéticas , Estrutura Molecular , Família Multigênica , Oxirredução , Oxirredutases/química , Peptídeos/química , Quinazolinas/química
17.
BMC Cancer ; 19(1): 27, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30621625

RESUMO

BACKGROUND: Docetaxel was used to treat metastatic CRPC patients. However, Doc resistance in prostate cancer (PCa) hinders its clinical application. OBJECTIVE: To understand the underlying mechanisms by which Doc resistance is developed and to find novel therapeutic target to cure Doc resistant PCa has clinical importance. METHODS: We established Doc resistant cell lines and explored the role of Ezh2 in the development of Doc resistance by overexpressing its cDNA or using its inhibitor. RESULTS: We found that Ezh2 was induced in our established Doc resistant (DocR) cells, which was attributable to the silenced expression of miR-101-3p and miR-138-5p. Blockage of Ezh2 activity by either inhibitor or miRNA mimics could overcome Doc resistance by suppressing Doc-induced cancer stem cells populations. Mechanistically, Ezh2 activity was required for the induced expression of Nanog, Sox2 and CD44 upon Doc treatment. CONCLUSIONS: Targeting Ezh2 could overcome Doc resistance.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , MicroRNAs/genética , Neoplasias da Próstata/tratamento farmacológico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Docetaxel/efeitos adversos , Docetaxel/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Próstata/efeitos dos fármacos , Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia
18.
Nucl Med Commun ; 40(4): 361-369, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30664599

RESUMO

PURPOSE: We performed this meta-analysis to evaluate the prognostic value of maximum of standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) in patients with head and neck cancer. METHODS: Articles including prognostic value of PET/CT were searched in PubMed and subsequently analyzed. The primary outcome of interest was event-free survival, and the secondary outcome of interest was overall survival. Statistical analysis was performed using hazard ratio (HR) and odds ratio. Review manager 5.3 was used to generate the eligible data. RESULTS: A total of 28 studies with 1871 patients were included in this meta-analysis. The pooled HR for event-free survival was 1.84 [95% confidence interval (CI): 1.43-2.37, P<0.00001] with SUVmax, 3.38 (95% CI: 2.68-4.27, P<0.00001) with MTV, and 3.55 (95% CI: 2.69-4.70, P<0.00001) with TLG. Meanwhile, the pooled HR for overall survival was 1.07 (95% CI: 1.01-1.13, P=0.02) with SUVmax, 3.41 (95% CI: 2.33-4.97, P<0.00001) with MTV, and 2.75 (95% CI: 1.84-4.12, P<0.00001) with TLG. The results of analysis suggested that tumors with high volumetric parameters were associated with worse survival outcome. CONCLUSION: Prognostic value of MTV and TLG is superior to SUVmax, and MTV and TLG can be used as prognostic biomarkers to predict outcome in patients with head and neck cancer.


Assuntos
Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Humanos
19.
Gene ; 691: 1-7, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30599237

RESUMO

Triglycerides account for 99% of milk fat and play a central role in determining dairy product quality. Many factors influence triglyceride synthesis and milk fat secretion. MicroRNAs have been verified to be involved in numerous biological processes, but little is known about their roles in milk fat biosynthesis. In this study, we aim to explore whether miR-454 could regulate triglyceride synthesis in bovine mammary epithelial cells (BMECs) by targeting PPAR-γ. A luciferase reporter assay showed that the predicted target site was correct and that miR-454 and PPAR-γ had a direct interaction. In addition, miR-454 mimics and inhibitors were transfected into BMECs. The results showed that both the mRNA and protein levels of PPAR-γ were negatively correlated with miR-454 expression. Fat droplet accumulation and triglyceride production were also inversely correlated with miR-454 expression. Our results indicate that miR-454 regulates triglyceride synthesis by directly targeting the PPAR-γ 3' UTR in BMECs, suggesting that miR-454 could potentially be a new factor to elevate dairy product quality.


Assuntos
Glândulas Mamárias Animais/metabolismo , MicroRNAs/genética , PPAR gama/genética , Triglicerídeos/metabolismo , Regiões 3' não Traduzidas , Animais , Bovinos , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica , Glândulas Mamárias Animais/citologia , Leite/química , PPAR gama/metabolismo
20.
Opt Express ; 26(23): 30278-30291, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30469903

RESUMO

Multiple scattering is an inevitable effect in spaceborne oceanic lidar because of the large footprint size and the high optical density of seawater. The effective attenuation coefficient klidar in the oceanic lidar equation, which indicates the influence of the multiple scattering effect on the formation of lidar returns, is an important parameter in the retrieval of inherent optical properties (IOPs) of seawater. In this paper, the relationships between klidar of the spaceborne lidar signal and the IOPs of seawater are investigated by solving the radiative transfer equation with an improved semianalytic Monte Carlo model. Apart from the geometric loss factors, klidar is found to decrease exponentially with the increase of depth in homogeneous waters. klidar is given as an exponential function of depth and IOPs of seawater. The mean percentage errors between klidar calculated by the exponential function and the simulated ones in three typical stratified waters are within 0.5%, proving the effectiveness and applicability of this klidar-IOPs function. The results in this paper can help researchers have a better understanding of the multiple scattering effect of spaceborne lidar and improve the retrieval accuracy of the IOPs and the chlorophyll concentration of case 1 water from spaceborne lidar measurements.

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