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1.
Inorg Chem ; 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31498607

RESUMO

LiBaPO4:Eu2+ phosphor and Ag-coated LiBaPO4:Eu2+ composites (Ag/LiBaPO4:Eu2+) were prepared via solid-state reaction and traditional photoreduction methods, respectively. The samples were characterized via XRD, SEM, and UV-vis optical absorption spectroscopy. Two photoenergy conversion processes, namely, photocatalysis and photoluminescence, were investigated in detail. In comparison with as-prepared LiBaPO4:Eu2+ phosphor, Ag-modified composites exhibited the enhanced photocatalytic effects together with the quenched Eu2+ luminescence. A Schottky barrier was created on the interface between Ag nanoparticles and LiBaPO4 host, thereby greatly delaying the recombination between the light-induced holes and electrons. A photoenergy conversion mechanism was suggested and discussed on the basis of the experiments. The Eu2+ ion luminescence centers directly participated in the photodegradation with the meditation of Ag nanoparticles on the surface. With the increase of the Ag coating level on the surfaces, some emission peaks corresponding to 5D0 → 7F0,1,2,3,4 transitions of Eu3+ ions were detected. Eu2+/Eu3+ couples also play an important role in improving photocatalysis. LiBaPO4:Eu2+ phosphor is a good candidate for the investigation of multimodal photoenergies of photoluminescence and photocatalysis.

2.
Opt Express ; 27(14): 19359-19368, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31503696

RESUMO

We report on an ultra-long range optical frequency domain reflectometry (OFDR) using a coherence-enhanced highly linear frequency-swept fiber laser source based on an optoelectronic phase-locked loop (OPLL). The frequency-swept fiber laser is locked to an all-fiber-based Mach-Zehnder interferometer (MZI) to suppress sweep nonlinearity and enhance the laser coherence, leading to a high coherence linear frequency sweep of 1 GHz in the duration time of 25 ms. This enables the OFDR to realize an ultra-long range measurement with a high spatial resolution. As a result, we obtain a 10 cm transform-limited spatial resolution at a 20 km fiber within 25 ms measurement time, and a 72 cm spatial resolution over an entire 200 km fiber link within 5 ms measurement time. The proposed reflectometry provides a high-performance solution with both high spatial resolution and ultra-long measurement range for field real-time fiber network monitoring and sensing applications.

3.
J Agric Food Chem ; 67(34): 9643-9651, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31390199

RESUMO

Licorice is a traditional Chinese medicine, which is often used as sweetener and cosmetic ingredients in food and pharmaceutical industries. Among them, glycyrrhetic acid is one of the most important agents. Studies have shown that glycyrrhetic acid exhibited antitumor activities as PPARγ agonist. However, the limited number of PPARγ glycyrrhetinic agonists and their high toxicity greatly limit the design based on the structure. Therefore, clarifying the binding mode between PPARγ and small molecules, we focused on the introduction of a natural active piperazine skeleton in the position of glycyrrhetinic acid C-3. According to the Combination Principle and the Structure-Based Drug Design, 19 glycyrrhetic acid derivatives were designed and synthesized as potential PPARγ agonists. Compounds 4c and 4q were screened as high-efficiency and low-toxicity lead compounds.

4.
Tissue Cell ; 59: 51-61, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31383289

RESUMO

We used a murine spontaneous osteosarcoma cell line with high metastatic potential, the K7M2 cell line to study the role of Notch signaling in the biological manifestations of osteosarcoma, to understand its underlying mechanism in the regulation of cell proliferation and migration, and to improve patient prognosis in cases of osteosarcoma through the discovery of novel therapeutic targets, First, Notch expression in K7M2 was determined by immunostaining, and the γ-secretase inhibitor N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) was used to inhibit proteolytic cleavage of the Notch intracellular domain (NICD), resulting in the inhibition of Notch activation. By using the Sulforhodamine B assay, colony-forming units assay, Brdu and Ki67 staining, and flow cytometry assays of apoptosis and cell cycle stage, DAPT was found to inhibit K7M2 proliferation in a dose-dependent manner. By using wound healing and transwell migration assays, DAPT was found to inhibit K7M2 migration in a dose-dependent manner as well. By using a combination of micro-Raman spectroscopy and K-means clustering analysis, we found that DAPT inhibit a variety of important cell metabolism-related components in most K7M2 cell structures. Then, DAPT was found to inhibit Notch1ICD expression in a concentration-dependent manner, and this expression was directly correlated with Phospho-Erk1/2 (p-Erk) by using Western blotting. To confirm this finding, we used the Notch signaling ligand Jagged1 to activate the Notch signaling pathway, which in turn up-regulated p-Erk, resulting in increased proliferation and migration of K7M2. Using the Erk pathway inhibitor U0126, we showed that p-Erk was downregulated and the proliferation and migration of K7M2 decreased along with it. Finally, we constructed a K7M2 mouse para-tibial tumor model and lung metastatic model. We found DAPT inhibits p-Erk in vivo, effectively controls tumor growth, reduces angiogenesis, reduces metastasis to the lungs, and improves overall survival. In summary, Notch signaling plays an oncogene role and promotes metastasis in osteosarcoma through p-Erk. DAPT effectively inhibits osteosarcoma proliferation and metastasis in vivo and in vitro by inhibiting Erk phosphorylation. Therefore, the inhibition of Notch activation resulted the down-regulation of phosphorylation of Erk pathway can be used as potential therapeutic targets in clinical treatment to improve osteosarcoma prognosis.

5.
Neural Netw ; 119: 93-112, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31404806

RESUMO

Analysis dictionary learning (ADL) has been successfully applied to a variety of learning systems. However, the ordinal locality of analysis dictionary has rarely been explored in constructing discriminative terms. In this paper, a discriminative low-rank analysis-synthesis dictionary learning (LR-ASDL) algorithm with the adaptively ordinal locality is proposed for object classification. Specifically, we first explicitly introduce the relations between the analysis atoms and profiles (i.e., row vectors of the coefficients matrix). That is, the similarity between two profiles depends on that between the corresponding analysis atoms. Moreover, an adaptively ordinal locality preserving(AOLP) term is constructed by simultaneously exploiting the profiles and analysis atoms, which can be learned in a supervised way. In this way, the neighborhood correlations between analysis atoms and the high-order ranking information of each analysis atom's neighbors can be simultaneously preserved in the learning process. Particularly, this helps to uncover the intrinsic underlying data factors and inherit the geometry structure information of training samples. Furthermore, the low-rank model is imposed on the synthesis atoms to further facilitate the learned dictionaries to be more discriminative. Extensive experimental results on eight databases demonstrate that the LR-ASDL algorithm clearly outperforms some analysis and synthesis dictionary learning algorithms using deep and hand-crafted features.

6.
J Phys Chem A ; 123(33): 7218-7227, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31361131

RESUMO

The reaction OH + SO → H + SO2 plays an important role in the combustion of sulfur-containing fuels and the environment. Its reaction profile resembles that of OH + CO → H + CO2, which presents a prototypical reaction with the formation of deep complexes. In this work, a new potential energy surface (PES) for the OH + SO → H + SO2 reaction is developed based on ca. 39 200 data points calculated at the level of the explicitly correlated unrestricted coupled cluster method with single, double, and perturbative triple excitations with the augmented correlation-consistent polarized triple zeta basis set (CCSD(T)-F12a/AVTZ). The PES is invariant with respect to the permutation of the two identical oxygen atoms, which is guaranteed by the permutation-invariant polynomials as the input layer of the neural network. Using this PES, the quasiclassical trajectory method is employed to study the collision energy transfer between H and SO2 at the experimental translational energy of 59 kcal mol-1. The predicted large integral cross sections for trajectories producing SO2 with high vibrational energy and populations of the SO2 vibrational energy are in good agreement with the recent experimental and theoretical results. Detailed analysis shows that there are two possible mechanisms, a direct mechanism (without passing through HOSO or the HSO2 well) and an indirect one (passing through one or both wells). The latter dominates in producing SO2 with high vibrational energy.

7.
Rev Sci Instrum ; 90(6): 064102, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31254989

RESUMO

The rapid development of the optically pumped magnetometer (OPM) has offered a much more flexible method for magnetoencephalography (MEG). Without using liquid helium and its associated dewar device in the OPM detectors, the large and expensive magnetically shielded room (MSR) for traditional MEG systems could be replaced by a compact shield. In the present work, an economic and compact cylindrical shield was designed and built to meet the low-field working requirement of the OPM in detecting human brain neuronal activities. The performance of the compact shield was evaluated and further compared with that of a commercial MSR. Our results showed that the residual magnetic fields and background noise of the compact shield were lower than or comparable to those of the MSR. The remnant field in the shield is found to be 4.2 nT, a factor of 13 000 smaller than the geomagnetic field which is applied to the transverse direction of the shield, and the longitudinal shielding factors measured using a known alternating-current magnetic field are approximately 191, 205, and 3130 at 0.1 Hz, 1 Hz, and 10 Hz, respectively; in addition, the evoked dynamic waveforms in the human auditory cortex that were recorded separately in these two shields demonstrated consistency. Our findings suggested that a compact shield is feasible for OPM-based MEG applications with high performance and low cost.

8.
Acta Crystallogr C Struct Chem ; 75(Pt 7): 927-934, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31271381

RESUMO

Two acylhydrazone complexes, bis{6-methyl-N'-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N',O}nickel(II), [Ni(C13H12N5O)2], (I), and di-µ-azido-κ4N1:N1-bis({6-methyl-N'-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N',O}nickel(II)), [Cu2(C13H12N5O)2(N3)2], (II), derived from 6-methyl-N'-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazide (HL) and azide salts, have been synthesized. HL acts as an N,N',O-tridentate ligand in both complexes. Complex (I) crystallizes in the orthorhombic space group Pbcn and has a mononuclear structure, the azide co-ligand is not involved in crystallization and the Ni2+ centre lies in a distorted {N4O2} octahedral coordination environment. Complex (II) crystallizes in the triclinic space group P-1 and is a centrosymmetric binuclear complex with a crystallographically independent Cu2+ centre coordinating to three donor atoms from the deprotonated L- ligand and to two N atoms belonging to two bridging azide anions. The two- and one-dimensional supramolecular structures are constructed by hydrogen-bonding interactions in (I) and (II), respectively. The in vitro urease inhibitory evaluation revealed that complex (II) showed a better inhibitory activity, with the IC50 value being 1.32±0.4 µM. Both complexes can effectively bind to bovine serum albumin (BSA) by 1:1 binding, which was assessed via tryptophan emission-quenching measurements. The bioactivities of the two complexes towards jack bean urease were also studied by molecular docking. The effects of the metal ions and the coordination environments in the two complexes on in vitro urease inhibitory activity are preliminarily discussed.

9.
Appl Microbiol Biotechnol ; 103(16): 6759-6769, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31230100

RESUMO

Confocal Raman microspectral imaging (CRMI) is an advanced cell-imaging method that maps endogenous molecular compositions with their unique spectral fingerprint indicators. The aim of this work was to provide a visualized understanding of subcellular features of live osteosarcoma cells using a 532-nm laser excitation without the use of dyes or molecular probes. Both malignant osteoblast and spindle osteosarcoma cells derived from the BALB/c mouse osteosarcoma cell line K7M2 were investigated in this work. After preprocessing the obtained spectral dataset, K-means cluster analysis (KCA) is employed to reconstruct Raman spectroscopic maps of single biological cells by identifying regions of the cellular membrane, cytoplasm, organelles, and nucleus with their corresponding mean spectra. Principal component analysis (PCA) was further employed to indicate variables of significant influence on the separation of the spectra of each cellular component. The biochemical components of the two cell types were then extracted by showing the spectral and distribution features attributed to proteins, lipids, and DNA. Using this standardized CRMI technique and multivariate analysis approaches, the results obtained could be a sound foundation for a typical Raman imaging protocol of live cellular biomedical analysis.

10.
Clinics (Sao Paulo) ; 74: e741, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31166471

RESUMO

OBJECTIVES: Osteoporotic vertebral compression fractures (OVCFs) affect the elderly population, especially postmenopausal women. Percutaneous kyphoplasty is designed to treat painful vertebral compression fractures for which conservative therapy has been unsuccessful. High-viscosity cement can be injected by either a hydraulic pressure delivery system (HPDS) or a balloon tamp system (BTS). Therefore, the purpose of this study was to compare the safety and clinical outcomes of these two systems. METHODS: A random, multicenter, prospective study was performed. Clinical and radiological assessments were carried out, including assessments of general surgery information, visual analog scale, quality of life, cement leakage, and height and angle restoration. RESULTS: Using either the HPDS or BTS to inject high-viscosity cement effectively relieved pain and improved the patients' quality of life immediately, and these effects lasted at least two years. The HPDS using high-viscosity cement reduced cost, surgery time, and radiation exposure and showed similar clinical results to those of the BTS. In addition, the leakage rate and the incidence of adjacent vertebral fractures after the HPDS treatment were reduced compared with those after treatment using the classic vertebroplasty devices. However, the BTS had better height and angle restoration abilities. CONCLUSIONS: The percutaneous HPDS with high-viscosity cement has similar clinical outcomes to those of traditional procedures in the treatment of vertebral fractures in the elderly. The HPDS with high-viscosity cement is better than the BTS in the treatment of mild and moderate OVCFs and could be an alternative method for the treatment of severe OVCFs.

11.
Med Sci Monit ; 25: 4110-4121, 2019 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-31154455

RESUMO

BACKGROUND The tumor microenvironment in lung cancer plays an important role in tumor progression and metastasis. Bone marrow-derived mesenchymal stem cells (MSCs) co-cultured with A549 lung cancer cells show changes in morphology, increase cell proliferation, and cell migration. This study aimed to investigate the effects of Astragalus polysaccharide (APS), a traditional Chinese herbal medicine, on the changes induced in bone marrow-derived MSCs by A549 lung cancer cells in vitro. MATERIAL AND METHODS Bone marrow-derived MSCs were co-cultured with A549 cells (Co-BMSCs). Co-cultured bone marrow-derived MSCs and A549 cells treated with 50 µg/ml of APS (Co-BMSCs + APS) were compared with untreated Co-BMSCs. Cell proliferation was measured using the cell counting kit-8 (CCK-8) assay. Flow cytometry evaluated the cell cycle. Microarray assays for mRNA expression and Western blot for protein expression were used. RESULTS Compared with untreated Co-BMSCs, APS treatment of Co-BMSCs improved cell morphology, reduced cell proliferation, and inhibited cell cycle arrest. The mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-kappaB) pathway, TP53, caspase-3, acetylated H4K5, acetylated H4K8, and acetylated H3K9 were involved in the regulatory process. CONCLUSIONS APS treatment reduced cell proliferation and morphological changes in bone marrow-derived MSCs that were co-cultured with A549 lung cancer cells in vitro.

12.
Bioorg Chem ; 88: 102958, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054434

RESUMO

A series of novel 1,4-benzodioxane thiazolidinedione piperazine derivatives targeting FabH were designed and synthesized. The compounds exhibited better inhibitory activity against Gram-negative bacteria by computer-assisted screening, antibacterial activity test and E. coli FabH inhibitory activity test, wherein compound 6j exhibited the most significant inhibitory activity (MIC = 1.80 µΜ for P. aeruginosa, MIC = 1.56 µΜ for E. coli). Besides, compound 6j still showed the best E. coli FabH inhibitory activity (IC50 = 0.06 µΜ). Moreover, the antibacterial activities of all compounds were strongly correlated with the inhibitory ability of FabH, with a correlation coefficient of 0.954. Computational docking studies also showed that compound 6j has interacting with FabH key residues in the active site.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31056524

RESUMO

Both interclass variances and intraclass similarities are crucial for improving the classification performance of discriminative dictionary learning (DDL) algorithms. However, existing DDL methods often ignore the combination between the interclass and intraclass properties of dictionary atoms and coding coefficients. To address this problem, in this paper, we propose a discriminative Fisher embedding dictionary learning (DFEDL) algorithm that simultaneously establishes Fisher embedding models on learned atoms and coefficients. Specifically, we first construct a discriminative Fisher atom embedding model by exploring the Fisher criterion of the atoms, which encourages the atoms of the same class to reconstruct the corresponding training samples as much as possible. At the same time, a discriminative Fisher coefficient embedding model is formulated by imposing the Fisher criterion on the profiles (row vectors of the coding coefficient matrix) and coding coefficients, which forces the coding coefficient matrix to become a block-diagonal matrix. Since the profiles can indicate which training samples are represented by the corresponding atoms, the proposed two discriminative Fisher embedding models can alternatively and interactively promote the discriminative capabilities of the learned dictionary and coding coefficients. The extensive experimental results demonstrate that the proposed DFEDL algorithm achieves superior performance in comparison with some state-of-the-art dictionary learning algorithms on both hand-crafted and deep learning-based features.

14.
Oncologist ; 24(9): 1159-1165, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30996009

RESUMO

BACKGROUND: Computed tomography (CT) is essential for pulmonary nodule detection in diagnosing lung cancer. As deep learning algorithms have recently been regarded as a promising technique in medical fields, we attempt to integrate a well-trained deep learning algorithm to detect and classify pulmonary nodules derived from clinical CT images. MATERIALS AND METHODS: Open-source data sets and multicenter data sets have been used in this study. A three-dimensional convolutional neural network (CNN) was designed to detect pulmonary nodules and classify them into malignant or benign diseases based on pathologically and laboratory proven results. RESULTS: The sensitivity and specificity of this well-trained model were found to be 84.4% (95% confidence interval [CI], 80.5%-88.3%) and 83.0% (95% CI, 79.5%-86.5%), respectively. Subgroup analysis of smaller nodules (<10 mm) have demonstrated remarkable sensitivity and specificity, similar to that of larger nodules (10-30 mm). Additional model validation was implemented by comparing manual assessments done by different ranks of doctors with those performed by three-dimensional CNN. The results show that the performance of the CNN model was superior to manual assessment. CONCLUSION: Under the companion diagnostics, the three-dimensional CNN with a deep learning algorithm may assist radiologists in the future by providing accurate and timely information for diagnosing pulmonary nodules in regular clinical practices. IMPLICATIONS FOR PRACTICE: The three-dimensional convolutional neural network described in this article demonstrated both high sensitivity and high specificity in classifying pulmonary nodules regardless of diameters as well as superiority compared with manual assessment. Although it still warrants further improvement and validation in larger screening cohorts, its clinical application could definitely facilitate and assist doctors in clinical practice.

16.
Eur Radiol ; 29(7): 3450-3457, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30820721

RESUMO

OBJECTIVES: To investigate the diagnostic value of clivopalate angle (CPA) for basilar invagination (BI) at magnetic resonance imaging (MRI). METHODS: In this retrospective case-control study, CPA, clivodens angle (CDA), and clivoaxial angle (CXA) were measured on midsagittal MR images from 112 patients with BI (22 men; mean age, 43.9 years ± 13.1 years; range, 21-79 years) and 200 control subjects (57 men; mean age, 47.1 years ± 13.3 years; range, 20-80 years). Intraclass correlation coefficient (ICC), linear regression, Mann-Whitney U test, binary logistic regression, and receiver operating characteristic (ROC) curve were used for statistical analysis. RESULTS: Clivopalate angle showed better inter-observer agreement (ICC = 0.951) than CXA (0.867) or CDA (0.853). CPA significantly correlated with CXA (R = 0.811, p < 0.001) and CDA (R = 0.716, p < 0.001). Patients with BI had a significantly smaller CPA (45.9° ± 9.9°) than control subjects (61.9° ± 6.2°) (p < 0.001). With the optimal cutoff value of 53.5°, CPA had a sensitivity of 0.839 (94/112) and a specificity of 0.915 (183/200). The area under the ROC curve (AUC) was 0.937 (95% CI, 0.911-0.963) for CPA, which was similar to that of CXA (AUC, 0.957; 95% CI, 0.936-0.978) or CDA (AUC, 0.925; 95% CI, 0.892-0.957). The combination of CPA and CDA or CXA showed a higher diagnostic value than CDA or CXA alone. CONCLUSIONS: The diagnostic performance of CPA was similar to that of CXA or CDA, but CPA might be more reliable in evaluation of BI. CPA provided complementary information to CXA and CDA. KEY POINTS: • Clivopalate angle has a high diagnostic value for basilar invagination. • Clivopalate angle demonstrates high inter-reader agreement than does clivoaxial angle or clivodens angle. • Clivopalate angle provides complementary information to clivoaxial angle and clivodens angle.


Assuntos
Articulação Atlantoaxial/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Platibasia/diagnóstico , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Adulto Jovem
17.
J Biomed Mater Res A ; 107(8): 1628-1639, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30916874

RESUMO

Titanium alloys are widely accepted as orthopedic or dental implant materials in the medical field. It is important to evaluate the biocompatibility of an implant material prior to use. A new ß-type ultrafine-grained Ti-28Nb-2Zr-8Sn (TNZS) alloy with low Young's modulus of 31.6 GPa was fabricated. This study aims to evaluate the biocompatibility of TNZS alloy. In this study, we examined the microstructure, chemical composition and surface wettability of the TNZS alloy. The mouse embryonic osteoblast MC3T3-E1 cells and human umbilical vein endothelial cells (HUVECs) were cultured to study the cytocompatibility of TNZS alloy. Also, we evaluated the proinflammatory response of TNZS alloy in vitro and in vivo. The results show that the TNZS did not cause cytotoxicity, genotoxicity to MC3T3-E1 cells and HUVECs. Whereas, the TNZS alloy could significantly promote the cell proliferation, cell spreading and cell adhesion of MC3T3-E1 cells and HUVECs, as well as facilitate the osteogenic differentiation of MC3T3-E1 cells. Moreover, the TNZS alloy did not induce any remarkable proinflammatory response in vitro and in vivo. Thus, the novel TNZS alloy with an elasticity closer to that of human bone is biologically safe and could be a potential candidate for biomedical implant application. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1628-1639, 2019.

18.
Appl Opt ; 58(4): 734-738, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30874114

RESUMO

A high-sensitivity optically pumped atomic magnetometer working in the geomagnetic range utilizing the light-narrowing effect and in-phase excitation is described. The setup is based on a simple pump-probe arrangement built around a Cs vapor cell whose active volume is 64 mm3. The transverse oscillating field is applied parallel to the probe beam to drive Zeeman resonance, and the in-phase component of the resonance signal is measured to determine the field. The sensitivity of the magnetometer is improved by pumping most atoms into the stretched state. Consequently, spin-exchange relaxation is suppressed, and a sensitivity of 0.1 pT/Hz1/2 in the range of 10 µT is achieved. This magnetometer has the advantages of large dynamic range, high performance of low-frequency stabilization, high response speed, and compact size. It can be used for many cutting-edge applications such as detection of magnetic anomalies.

19.
Inorg Chem ; 58(6): 4033-4037, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30840445

RESUMO

To take the advantage of the synergy of atom filling and pressure regulation, atom Pb was assumed to play the role of fillers to occupy the Sb-icosahedron voids. In this paper, skutterudite Pb xCo4Sb11.5Te0.5 materials have been synthesized by high-pressure and high-temperature (HPHT) method with 0.5 h processing time. Although the increase of Pb filling rate increased the electrical resistivity of samples, it reduced the thermal conductivity of samples significantly. When the synthesis pressure increased, the Seebeck coefficients of Pb0.2Co4Sb11.5Te0.5 increased, and the thermal conductivity decreased. The crystal morphology and structure of samples, which can effectively affect the thermoelectric properties of materials, were investigated with XRD, Raman spectra, SEM mapping, and HR-TEM analysis.

20.
Doc Ophthalmol ; 138(2): 125-135, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30756213

RESUMO

PURPOSE: Glaucoma is a common chronic neurodegenerative disease, which could lead to visual loss. In this study, we aimed to investigate whether fisetin, a natural flavone with anti-inflammatory and antioxidant properties, is able to alleviate glaucoma. METHODS: We employed a DBA/2J mouse model which was treated with or without fisetin. Pattern electroretinogram (P-ERG), visual evoked potentials (VEPs) and intraocular pressure (IOP) were evaluated. Quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) were used to measure the expression levels of TNF-α, IL-1ß and IL-6. Western blotting was performed to assess the activation of nuclear factor kappa-B (NF-κB). RESULTS: We found that DBA/2J mice treated with fisetin (10-30 mg/kg) showed improved P-ERG and VEP amplitudes and reduced IOP compared to untreated DBA/2J mice. In addition, there were more survived retinal ganglion cells (RGCs) and less activated microglia in fisetin-treated DBA/2J mice than those in untreated mice. Furthermore, secreted protein levels and mRNA levels of TNF-α, IL-1ß and IL-6 were significantly repressed by fisetin. The phosphorylated p65 level in the nucleus was dramatically reduced in fisetin-treated mice compared to it in untreated mice. Our results demonstrate that fisetin may exert its function through regulating cytokine productions and inhibiting NF-κB activation in the retina. CONCLUSION: In conclusion, fisetin is able to promote the visual functions of DBA/2J mice by inhibiting NF-κB activation.


Assuntos
Antioxidantes/uso terapêutico , Modelos Animais de Doenças , Potenciais Evocados Visuais/fisiologia , Flavonoides/uso terapêutico , Glaucoma/prevenção & controle , Inflamação/prevenção & controle , Retina/fisiopatologia , Animais , Western Blotting , Citocinas/genética , Citocinas/metabolismo , Eletrorretinografia , Ensaio de Imunoadsorção Enzimática , Feminino , Glaucoma/metabolismo , Glaucoma/fisiopatologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Pressão Intraocular/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , NF-kappa B/metabolismo , Células Ganglionares da Retina , Tonometria Ocular
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