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1.
J Nanosci Nanotechnol ; 20(4): 2408-2415, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492255

RESUMO

New synthetic method toward carbon supported catalysts with improved performance is of great importance in direct alcohol fuel cells (DAFCs). Herein, onion-like nanocarbons (OLNCs) were fabricated by using cheap and readily available candle as the raw material. And a facile one-pot and surfactant-free solvothermal approach was developed for the fabrication of PtSn nanoparticles supported on the OLNCs. Transmission electron microscopy (TEM) images showed the highly crystalline PtSn nanoparticles with size of ~2-5 nm were evenly deposited on the surface of the OLNCs. The obtained PtSn/OLNCs nanocomposites with Pt loading of about 10.1% exhibited excellent electrocatalytic activity toward both methanol oxidation reactions (MOR) and ethylene glycol oxidation reactions (EGOR). The current density of PtSn/OLNCs is 2.6 and 2.7 times of the commercial 20 wt% Pt/C toward the MOR and EGOR, respectively, suggesting the great application potential of the PtSn/OLNCs catalyst in DAFCs. The highly electrocatalytic activity of the PtSn/OLNCs may arise from the ultra-small size of the PtSn NPs as well as the large surface area and good electric conductivity of the OLNCs support. This study not only provides an example of the cost-effective fabrication and application of the OLNCs based catalysts and also sheds a new light on the application of the PtSn/OLNCs catalyst in DAFS.

2.
Front Biosci (Schol Ed) ; 12: 70-91, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31585866

RESUMO

Green tea (Camellia sinensis, Theaceace), has been extensively studied for its putative effects in prevention of age related diseases. Here, we discuss the increasing evidence that consumption of green tea has preventative effects in obesity, hypertension, insulin resistance, type II diabetes, atherosclerosis, coronary heart disease and Metabolic Syndrome (MetS). The catechins in green tea has been found to be beneficial in obesity induced by a high-fat diet. These effects are mainly attributable to the gallate esters of catechins, (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3- gallate (EGCG).

3.
Appl Opt ; 58(27): 7615-7620, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674417

RESUMO

Laser-induced breakdown spectroscopy (LIBS), an element-detection technology with the advantages of no sample preparation and in situ detection of metal samples, is suitable for the quantitative analysis of metal samples. However, severe spectral interference in the detection of metal samples makes the quantitative analysis difficult. Three quantitative analysis methods, including single-variable calibration, partial least squares regression (PLSR), and support vector regression (SVR), are used to conduct the quantitative analysis of four common metal elements (Manganese (Mn), Chromium (Cr), Vanadium (V), and Titanium (Ti)). The PLSR model adds interference spectrum lines to the model for linear modeling, while the SVR model adds interference spectrum lines to the model for nonlinear modeling. The quantitative analysis results of the nonlinear SVR model are the best. The R square (R2) values of Mn, Cr, V, and Ti are 0.993, 0.995, 0.990, and 0.992, respectively. The root-mean-squared errors of the prediction set of Mn, Cr, V, and Ti are 0.044, 0.045, 0.011, and 0.014, respectively. Therefore, the results of PLSR and SVR are better than the calibration curves of the spectral intensity and concentration due to the influence of multivariate factors. SVR has almost no element bias, while PLSR and the single-variable calibration model have different quantitative results due to the different degrees of influence on spectral lines. These results demonstrate that the combined influence of the spectral interference, background noise, and self-absorption can be suppressed by the nonlinear quantitative analysis model in the steel field using LIBS.

4.
Food Chem ; 309: 125686, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31670130

RESUMO

Reducing sugars can react with 1-phenyl-3-methyl-5-pyrazolone (PMP) to form sugar-PMP derivatives, which can be detected by HPLC-UV or HPLC-DAD due to their high UV absorbance at 248 nm. Six different sugars were synthesized with PMP with aid of response surface methodology (RSM), by which the parameters of the synthesis were designed within temperature ranged between 60 °C and 90 °C, and time from 60 to 180 min, respectively. Consequently, optimal conditions of the glucose (Glu)-, glucosamine (GluN)-, galactose (Gal)-, glucuronic acid (GluA), galacturonic acid (GalA) and glucose-6-phosphate (G6P-PMP) reactions were determined at 71 °C for 129 min, 73 °C for 96 min, 70 °C for 117 min, 75 °C for 151 min, 76 °C for 144 min, and 70 °C for 154 min, respectively. Experiments demonstrated that unique functional groups and delicate differences of carbohydrates' inner pH environment could significantly influence the sugar-PMP reactions. However, sugar stereoisomers did not have remarkable impacts on the reactions.

5.
Genome Biol ; 20(1): 226, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31672156

RESUMO

As metagenomic studies move to increasing numbers of samples, communities like the human gut may benefit more from the assembly of abundant microbes in many samples, rather than the exhaustive assembly of fewer samples. We term this approach leaderboard metagenome sequencing. To explore protocol optimization for leaderboard metagenomics in real samples, we introduce a benchmark of library prep and sequencing using internal references generated by synthetic long-read technology, allowing us to evaluate high-throughput library preparation methods against gold-standard reference genomes derived from the samples themselves. We introduce a low-cost protocol for high-throughput library preparation and sequencing.

6.
J Agric Food Chem ; 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31638826

RESUMO

Zeaxanthin is a value-added carotenoid with wide applications. This study aims to manipulate a generally recognized as safe and carotenoid-producing bacterium, Sphingobium sp., for enhanced production of zeaxanthin and exopolysaccharides. First, whole-genome sequencing and analysis of pathway genes were applied to define the carotenoid pathway in Sphingobium sp. Second, a Sphingobium transformation system was established to engineer metabolite flux into zeaxanthin. By a combination of chemical mutagenesis and removal of bottlenecks of carotenoid biosynthesis via overexpression of three rate-limiting enzymes, the genetically modified Sphingobium DIZ strain produced 21.26 mg/g dry cell weight of zeaxanthin, which was about 4-fold higher than the wild type. Upon optimization of culture conditions, the DIZ strain produced 479.5 mg/L of zeaxanthin with the productivity of 4.99 mg/L/h and 21.9 g/L of exopolysaccharides using a fed-batch fermentation strategy. This study represents the first genetic manipulation of Sphingobium sp., a biotechnologically important bacterium, for high-yield production of value-added metabolites.

7.
Rom J Morphol Embryol ; 60(2): 411-418, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31658313

RESUMO

Acupuncture is one of the oldest medical practices of Traditional Chinese Medicine (TCM). This method of treatment was discovered when primitive Chinese people discovered that pain in one part of the body can be alleviated if it stings in a particular area of the body. Acupuncture has achieved to a climax in Ming Dynasty (1368-1644 A.D.), when many famous doctors specialized in this field emerged with a lot of exclusive books on acupuncture, but the most important one was Compendium of Acupuncture and Moxibustion by Yang Jizhou, which represented a new milestone in the history of acupuncture's evolution. Yang Jizhou compiled a book that presents a complete and laborious description of the meridians, collaterals, acupuncture points, manipulating methods of acupuncture and their indications. According to the ancient description of the meridians and collaterals and the research on the anatomy of Western medicine, some scholars think the meridians and collaterals are closely related to the blood vessels. In recent years, many reports have showed that acupuncture has remarkable effect on the pituitary gland and adrenal cortex system, the sympathetic nerve and adrenal medulla system, the pituitary gland and thyroid gland system, the sexual glands, and the posterior pituitary system. Thus, some researchers put forth the theory of the meridians and collaterals associated with regulatory function of the neurohumoral system, and the action of acupuncture and moxibustion is brought about by the way of the nerves and body fluid.

8.
Rom J Morphol Embryol ; 60(2): 487-494, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31658322

RESUMO

Arterial hypertension (AH) represents the main cause of morbidity and mortality all over the world. Approximately 40% of the adults aged over 25 years old and about 90% of the persons aged over 80 years old suffer from AH. It is a multifactorial condition, in whose etiopathogeny there are involved numerous genetic, metabolic and environment factors. In its turn, AH is one of the most important risk factors for heart disease, stroke, heart failure, kidney disease and peripheral vascular diseases. In hypertensive patients, it progresses into the left ventricle hypertrophy, as a result of some major changes of the cardiomyocytes, but also of the extracellular conjunctive matrix (ECM). We evaluated some histopathological and immunohistochemical changes induced by AH on some fragments of myocardium from the left ventricle. There was observed an increase of the ECM quantity, manifested by the expansion of the intercellular spaces, fibrillar collagen synthesis and its deposit in the perivascular and interstitial spaces, a significant reduction of the number of microvessels in the myocardium, the alteration of cardiomyocyte structure, by reducing the quantity of desmin and of the intercellular connections, by reducing cluster of differentiation 56 (CD56) (neural cell adhesion molecule 1 - NCAM1) immunomarker.

9.
Nucleic Acids Res ; 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31584096

RESUMO

Spatially resolved visualization of RNA processing and structures is important for better studying single-cell RNA function and landscape. However, currently available RNA imaging methods are limited to sequence analysis, and not capable of identifying RNA processing events and structures. Here, we developed click-encoded rolling FISH (ClickerFISH) for visualizing RNA polyadenylation and structures in single cells. In ClickerFISH, RNA 3' polyadenylation tails, single-stranded and duplex regions are chemically labeled with different clickable DNA barcodes. These barcodes then initiate DNA rolling amplification, generating repetitive templates for FISH to image their subcellular distributions. Combined with single-molecule FISH, the proposed strategy can also obtain quantitative information of RNA of interest. Finally, we found that RNA poly(A) tailing and higher-order structures are spatially organized in a cell type-specific style with cell-to-cell heterogeneity. We also explored their spatiotemporal patterns during cell cycle stages, and revealed the highly dynamic organization especially in S phase. This method will help clarify the spatiotemporal architecture of RNA polyadenylation and structures.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31584221

RESUMO

Protein channels are characterized by high transport selectivity essential for maintaining proper cellular functions. Extensive efforts over the past four decades to recapitulate such high selectivity have not been very successfully. In this work, we report a novel series of aromatic foldamer-based polymeric channels, with the backbone stabilized by differential electrostatic repulsions among heteroatoms helically arrayed along in the helical backbone. Possessing a hydrophilic electron-rich hollow cavity of 3 Å in diameter, nanotubes of 2.3 and 2.7 nm in average length mediate highly efficient transport of K + ions, with exceptionally high K + /Na + selectivity values of 16.3 and 12.6, respectively.

11.
Asian J Androl ; 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31571639

RESUMO

Testosterone (T) plays a crucial role in spermatogenesis because extremely low levels of intratesticular T lead to correspondingly low serum levels of total T (tT), severe disorders of spermatogenesis, and male sterility. However, there is little consensus on the lower limits of serum tT in proven fertile men undergoing assisted reproductive technology treatments in Chinese or other Asian populations. We aimed to establish the reference range of serum tT based on a population of 868 fertile Chinese men undergoing in vitro fertilization or intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) treatments. We defined a fertile man as having had a live baby with his partner as recorded in our IVF registration system. The lower limits of serum tT were established using a Siemens IMMULITE 2000 chemiluminescent system. The 1st, 2.5th, and 5th percentiles and their 95% confidence intervals (CIs) were 3.6 (95% CI: 2.7-4.1) nmol l-1, 4.3 (95% CI: 4.1-5.0) nmol l-1, and 5.6 (95% CI: 4.8-5.8) nmol l-1, respectively. Using the linear correlation of serum tT between the Siemens platform and a liquid chromatography-tandem mass spectrometry platform, the calculated lower limits of serum tT were also established for fertile Chinese men undergoing IVF/ICSI-ET treatments, which will benefit the clinical diagnosis and treatment of male infertility during such procedures.

12.
Mol Plant ; 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31622682

RESUMO

Wheat stripe rust, due to infection by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease that is causing significant global grain yield losses. Yr36, which encodes the Wheat Kinase START1 (WKS1), is an effective high-temperature adult-plant resistance gene and confers resistance to a broad spectrum of Pst races. We previously showed that WKS1 phosphorylates the thylakoid ascorbate peroxidase (tAPX) protein and reduces its ability to detoxify peroxides, which may contribute to the accumulation of reactive oxygen species (ROS). WKS1-mediated Pst resistance is accompanied by leaf chlorosis in the Pst-infected regions, but the underlying mechanisms remain still elusive. Here, we show that WKS1 interacts with and phosphorylates PsbO, an extrinsic member of photosystem II (PSII), to reduce photosynthesis and regulate leaf chlorosis in conferring Pst resistance. A point mutation in PsbO-A1 or reductions in its transcript levels by RNA interference resulted in chlorosis and reduced Pst sporulation. Biochemical analyses revealed that WKS1 phosphorylates PsbO at two conserved amino acids involved in its physical interactions with PSII and reduces the binding affinity of PsbO to PSII. Phosphorylated PsbO dissociated from the PSII protein complex, and underwent fast degradation by cysteine and aspartic proteases. Taken together, these results demonstrate that perturbations of wheat PsbO by point mutation or its phosphorylation by WKS1 reduce photosynthesis rate and delays the growth of Pst pathogen before the induction of ROS.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31623216

RESUMO

High-polluting industries are important sources of pollutant emissions, and closely related to many environmental issues. High-polluting firms face the pressure to exploit technological innovation for improving their environmental operations. This paper explores the impact of corporate social responsibility and public attention on the innovation performance of high-polluting firms. Based on a sample of China's listed firms in high-polluting industries from 2011 to 2016, we use a panel data model to investigate the associations among corporate social responsibility, public attention and innovation performance. The results show that there is a positive association between corporate social responsibility and innovation performance. There is a positive association between public attention and innovation performance as well. The pressure of regional economies can hinder innovation performance. Furthermore, in the subsample of state-owned enterprises, the association between public attention and innovation performance is more pronounced. Meanwhile, the corporate social responsibility of non-state-owned enterprises plays a stronger role for innovation performance, but its effect will be limited by the pressure of regional economies. Our results can help high-polluting firms implement the innovation strategies for obtaining more environmental benefits and achieving sustainable development.

14.
Ann Vasc Surg ; 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31634610

RESUMO

INTRODUCTION: Therapeutic neovascularization has some obstacles, such as it requires more than one pro-angiogenic factor, and these factors have short half-lives. To overcome these obstacles, combined delivery of granulocyte-colony stimulating factor (G-CSF), erythropoietin (EPO) and vascular endothelial growth factor (VEGF) using protein/dextran/poly(lactic-co-glycolic acid) (PLGA) sustained-release microspheres was proposed to promote neovascularization. METHODS: Dextran microparticles loaded with G-CSF, EPO or VEGF were prepared and encapsulated in PLGA microspheres to obtain protein-dextran-PLGA microspheres. The release behavior of microspheres was studied in vitro. The protein/dextran/PLGA microspheres were injected into the ischemic hindlimbs of rats. Neovascularization in ischemic muscle was measured. RESULTS: Microspheres released G-CSF, EPO and VEGF in vitro for more than 4 weeks. Combined therapy with VEGF, EPO and G-CSF promoted the expression of B-cell lymphoma-2 and stromal cell-derived factor 1, cellular proliferation and the incorporation of C-X-C chemokine receptor 4 positive cells. Capillary density and smooth muscle α-actin+ vessel density were higher in the combined treatment of VEGF, EPO and G-CSF than in the single factor treatment. CONCLUSION: The combined and sustained delivery of VEGF, EPO and G-CSF using dextran-PLGA microspheres had a more significant neovascularization effect than monotherapy with each factor alone. This combined therapy might be a promising treatment for ischemic vascular diseases.

15.
ACS Appl Mater Interfaces ; 11(43): 40685-40693, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31599152

RESUMO

Personal cooling technology using functional clothing that could provide localized thermal regulation instead of cooling the entire space is regarded as a highly anticipated strategy to not only facilitate thermal comfort and human health but also be energy-saving and low-cost. The challenge is how to endow textiles with prominent cooling effect whenever the wearer is motionless or sportive. In this study, high content of edge-selective hydroxylated boron nitride nanosheets (BNNSs) up to 60 wt % was added into a biodegradable cellulose/alkaline/urea aqueous solution, and then regenerated cellulose (RCF)/BNNS multifilaments were successfully spun in a simple, low-cost, and environmentally friendly process, which was demonstrated to serve as both static and dynamic personal cooling textile. Typically, excellent axial thermal conductivity of RCF/BNNS filament rendered that body-generated heat could directly escape from skin to the outside surface of the textile by means of thermal conduction, achieving a much better static personal cooling result through continuous thermal radiation. Besides, synergistic effect between excellent heat dissipation capability and good hygroscopicity also resulted in much better dynamic cooling effect once the wearer is doing some sports, whose efficiency was even better than commercial hygroscopic textiles such as cotton and RCF.

16.
Biochem Biophys Res Commun ; 520(2): 434-440, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31607473

RESUMO

Listeria monocytogenes is a gram-positive food borne pathogen. The lmo2088 belongs to the TetR family of transcriptional regulators from L. monocytogenes. These transcriptional factors regulate multidrug resistance transporters in L. monocytogenes. Here, we report native protein crystal structure of lmo2088 at a resolution of 1.7 Å. Lmo2088 comprises of an N-terminal DNA binding domain and a variable C-terminal effector binding domain. Furthermore, we identified specific consensus sequences selected by systematic evolution of ligands by exponential enrichment in vitro. The specific binding of lmo2088 with DNA consensus sequence was validated by electrophoretic mobility shift assay, fluorescence polarization and isothermal titration calorimetry. We speculate that the structure of lmo2088 might provide an insight into the regulatory function of lmo2088 of L. monocytogenes.

17.
J Phys Chem Lett ; 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31664832

RESUMO

The interaction of BiFeO3 and Co-doped BiFeO3 thin film surfaces with water vapor is examined using photoelectron spectroscopy. Water exposure results in an upward shift of the Fermi energy, which is limited by the reduction of Bi and Fe in undoped BiFeO3 and by the reduction of Co in oxidized Co-doped BiFeO3. The results highlight the importance of surface potential changes induced by the interaction of solid surfaces with water and the ability of photoelectron spectroscopy to quantitatively determine electrochemical reduction potentials and defect energy levels.

18.
Invest Ophthalmol Vis Sci ; 60(13): 4503-4510, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31661551

RESUMO

Purpose: MicroRNA-34a (miR-34a) has been implicated in many biological processes. It is downregulated in uveal melanoma, and introduction of miR-34a inhibits the proliferation and migration of uveal melanoma cells. Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) is a novel target of miR-34a identified first in retinal pigment epithelial cells. In this study, we sought to evaluate the interaction of miR-34a and LGR4 in uveal melanoma and its downstream mechanisms. Methods: The expression of LGR4, epithelial-mesenchymal transition (EMT)-associated factors, and matrix metalloproteinase 2 (MMP2) in uveal melanoma cells was assessed by immunoblotting and immunofluorescence analysis. MicroRNA-34a mimic molecules, LGR4 small interfering RNA (siRNA), or MMP2-specific siRNA were transiently transfected into uveal melanoma cells. In vitro scratch and Transwell assays were used to evaluate the migratory and invasive potential of the resultant uveal melanoma cells. Results: LGR4 is upregulated in uveal melanoma cells. Introduction of miR-34a significantly decreased the expression level of LGR4. Transfection with miR-34a or knockdown of LGR4 attenuated the aggressiveness of uveal melanoma cells. In addition, there was a decrease in the expression of mesenchymal markers N-cadherin, vimentin, and Snail following miR-34a introduction or knockdown of LGR4. Finally, MMP2 was found to be a downstream effector for miR-34a and LGR4 that regulates the migration and invasion of uveal melanoma cells. Conclusions: MicroRNA-34a negatively controls LGR4, thereby inhibiting the migration and invasion of uveal melanoma cells. Ultimately, both miR-34a and LGR4 impact the aggressiveness of uveal melanoma with alterations in the markers of the EMT. MMP2 is a downstream effector that influences the metastasis seen with uveal melanoma cells.

19.
Rev Sci Instrum ; 90(9): 096101, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31575229

RESUMO

Refractive index of optical material of powder is measured not as easily as a bulk material. Here, the prism coupling technique in combination with the immersion method is proposed to measure the refractive index of an optical material of powder. First, the powder material to be measured was dispersed in α-bromonaphthalene (C10H7Br) liquid to form a suspension mixture. The refractive index of the mixture, together with that of pure C10H7Br, was then measured at the wavelengths of 632.8, 1311, and 1553 nm using a commercial prism coupler. From the measured index values of pure C10H7Br and powder-dispersed mixture, the refractive index of the powder material was obtained on the basis of the Maxwell-Garnett model. Microcrystal powder from a LiNbO3 single-crystal, which has the known refractive index values, has been exemplified to demonstrate the method. The results show that the method is feasible with an accuracy of ±0.05.

20.
J Colloid Interface Sci ; 559: 115-123, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31614316

RESUMO

Ni3S4 is regarded as one of the promising electrode materials for energy storage, but the difficulty in obtaining its pure phase hinders its wide applications. In this work, we introduced a novel method to in-situ synthesize Ni3S4@reduced graphene oxide (rGO) composite, where graphene oxide (GO) was found to induce the oxidation of Ni2+ to Ni3+ and the morphology transformation from microbar to polyhedron during the hydrothermal process. The influence of the content and oxidation degree of GO on the phase composition and morphology of nickel sulfide is investigated. It is found that the oxygen-containing functional group of GO is responsible for the change of valence state, which thus drives the transformation of NiS/Ni3S4 towards Ni3S4. The obtained Ni3S4@rGO composite shows a high energy storage capacity (1830 F g-1 at 2 A g-1), remarkably higher than the unpurified phase NiS/Ni3S4 (830 F g-1). Correspondingly, the assembled asymmetry supercapacitor indicates a high energy density of 37.3 Wh kg-1 at a power density of 398 W kg-1. More importantly, the capacitance retention reaches 91.4 % after 10,000 cycles at a current density of 2 A g-1. Thus, this research overcomes the difficulty of synthesizing the pure Ni3S4 phase, which provides a new available pathway for constructing high-performance electrode materials.

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