CircRNA MFACR Is Upregulated in Myocardial Infarction and Downregulates miR-125b to Promote Cardiomyocyte Apoptosis Induced by Hypoxia.

ABSTRACT: Circular RNA (circRNA) MFACR promotes cardiomyocyte death that leads to myocardial infarction (MI). This study aimed to explore the role of MFACR in MI. T-qPCRs were performed to measure the expression levels of MFACR and miR-125b in plasma samples from both MI patients (n = 61) and healthy controls (n = 61). MFACR or miR-125b was overexpressed in AC16 cells (cardiomyocytes) to explore the interaction between them. Methylation of miR-125b gene in cells with the overexpression of MFACR was detected by methylation-specific PCR. Cell apoptosis after transfections was detected by cell apoptosis assay. MI model was constructed to further demonstrate the effect of MFACR in vivo. We found that MFACR was upregulated in MI and inversely correlated with miR-125b. In AC16 cells, hypoxia treatment increased the expression levels of MFACR and decreased the expression levels of miR-125b. In AC16 cells, overexpression of MFACR decreased the expression levels of miR-125b and increased the methylation of miR-125b gene. Under hypoxia treatment, overexpression of MFACR increased AC16 cell apoptosis, and overexpression of miR-125b decreased cell apoptosis. In addition, overexpression of miR-125b reversed the effects of overexpression of MFACR on cell apoptosis both in vivo and in vitro.

[Characterization and molecular modification of ß-glucosidase from Citrobacter koser GXW-1].

Objective: The aim of this study was to characterize ß-glucosidase from Citrobacter koser GXW-1 isolated from soil and to improve the enzyme by molecular modification. Mehods: A bacterial strain with ß-glucosidase activity was screened from the soil around Wuming sugar mill in Guangxi by esculin-ferric ammonium citrate selecting plate. The 16S rDNA of the strain was obtained and analyzed. By searching GenBank database, the genes encoding ß-glucosidase from the same genus Citrobacter were found. These sequences were aligned. Then, a gene encoding ß-glucosidase was amplified by PCR. The recombinant plasmid pQE-cbgl was constructed. The recombinant protein was purified with Ni-NTA. The enzyme properties of the recombinant protein CBGL were studied in detail. At last, the wild enzyme CBGL was reformed by error-prone PCR and site-directed random mutagenesis. Results: C. koser GXW-1 with ß-glucosidase activity was isolated from the soil. A gene encoding ß-glucosidase was cloned from the wild strain GXW-1. The properties of CBGL were identified. Its optimal pH and temperature were 6.0 and 45℃. Its Km and Vmax value were (11.280±1.073) mmol/L and (0.1704±0.0073) µmol/(mg·min), respectively. Its Ki values was (66.84±3.40) mmol/L. CBGL can hydrolyze α-pNPG, stevioside, daidzin and genistin. CBGL was modified by error-prone PCR and site directed random mutagenesis. A positive mutant W147F was obtained successfully. Its Vmax was 2.54 times that of the wild enzyme CBGL. Conclusion: CBGL not only can hydrolyze ß-glycosidic bond, but also can hydrolyze the α-glycosidic bond in α-pNPG. Furthermore, CBGL can hydrolyze stevioside, daidzin and genistin. These characteristics indicate that the ß-glucosidase CBGL has important applications in theoretical research and in industry.

Selective production of rubusoside from stevioside by using the sophorose activity of ß-glucosidase from Streptomyces sp. GXT6.

In order to produce rubusoside, enzymes with preferential specificity for the saccharide sophorose were tested for ability to produce rubusoside from stevioside. We identified BGL1, a ß-glucosidase from Streptomyces sp. GXT6, as an enzyme for rubusoside production. Out of several saccharide substrates, BGL1 showed the most affinity to sophorose. This enzyme only hydrolyzes the glucose moiety of the sophoroside at C-13 in stevioside. Production of rubusoside was determined by (1)H and (13)C nuclear magnetic resonance (NMR). Thus, rubusoside was produced from stevioside and the stevioside conversion rate was 98.2 %. The production yield of rubusoside was 78.8 % in 6 h.

Rapid Evaporation of a Metal Electrode for a High-Efficiency Perovskite Solar Cell.

Organic-inorganic hybrid perovskite solar cells (PSCs) have attracted considerable attention due to the excellent optoelectronic properties of perovskite materials. The energy consumption and high cost issues of metal electrode evaporation should be addressed before large-scale manufacturing and application. We developed an effective metal electrode evaporation procedure for the fabrication of high-efficiency planar heterojunction (PHJ) PSCs, with an inverted device structure of glass/indium tin oxide (ITO)/poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA)/perovskite/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/(E)-ß-caryophyllene (BCP)/Ag. The effect of the evaporation rate for an evaporator with a small-volume metal cavity on the performance of PHJ-PSC devices was investigated systematically. Through controlling the processes of Ag electrode evaporation, the charge dynamics of the devices were studied by analyzing their charge recombination resistance and lifetime, as well as their defect state density. Our findings reveal that the evaporation rate of an evaporator with a small cavity is favorable for the performance of PHJ-PSCs. As a result, PHJ-PSCs fabricated using a very thin, non-doped PTAA film exhibit photoelectric conversion efficiency (PCE) of 19.21%, with an open-circuit voltage (Voc) of 1.132 V. This work showcases the great potential of rapidly evaporating metal electrodes to reduce fabrication costs, which can help to improve the competitiveness in the process of industrialization.

Nd:YGG crystal laser at 1110 nm: a potential source for detecting carbon monoxide poisoning.

We demonstrated a laser-diode pumped Nd-doped yttrium gallium garnet crystal laser at 1110 nm for the first time to our knowledge. By suppressing the oscillation at about 1.06 µm, continuous-wave output power of 2.1 W at 1110 nm was achieved. With a Cr:YAG as the saturable absorber, the passive Q-switching performance at this wavelength was obtained. The shortest pulse width and largest pulse energy were 31.5 ns and 22.7 µJ, respectively. Laser radiation at this wavelength is an important source for detecting carbon monoxide poisoning by simple frequency doubling with a nonlinear crystal.

Efficient Tm:LuVO4 laser at 1.9 µm.

We report an efficient laser-diode-pumped Tm-doped LuVO4 crystal laser at about 1.9 µm. For the first time to our knowledge, the π-polarized Tm:LuVO4 laser was achieved. The maximum output power and slope efficiency were 1.32 W and 28.7%, respectively. By comparison, it has been found that the a-cut Tm:LuVO4 crystal should be more suitable for applications in high-power lasers. The central laser wavelength was observed to be located at about 1.9 µm and shifted to shorter with the increase of intracavity light intensity, which could be explained based on the reabsorption of light in the Tm:LuVO4 crystal.

A continuous wave SrMoO4 Raman laser.

We demonstrate a cw, laser diode-pumped Nd:GdVO4/SrMoO4 crystalline Raman laser. First Stokes laser output at 1173.5 nm of 2.18 W was achieved with a diode-to-first Stokes efficiency of 8.7%. With intracavity frequency doubling in LiB3O5, 3.1 W of cw yellow emission at 586.8 nm was obtained with a 12.4% diode-to-yellow efficiency. The experimental results show that SrMoO4 is an excellent stimulated Raman scattering gain material for high-power cw near-IR Stokes and yellow lasers.

Fabrication of flower-like silver structures through anisotropic growth.

Using a simple chemical reaction, a new nanostructure of silver, which we call a "flower-like silver structure", is produced. The flower-like silver structure consists of a silver core and many rod-like tips protruding out in three dimensions. Besides common face-centered-cubic (FCC) phase of silver, there exists hexagonal-close-packed (HCP) phase in these tips. The appearance of HCP silver is the result of rapid growth of silver nuclei when using CH(2)O or C(2)H(4)O as the reducing agent. The formation of the rod-like tips is caused by the anisotropic growth determined by the HCP phase and the directing role of formic acid, which is the oxidation product of CH(2)O. It is also found that the concentration of reactants, the kind of reducing agents and the sequence of adding reactants can influence the morphology and phase constitution of the final products.

Simultaneous removal of SO2 and NOx from flue gas by low-temperature adsorption over activated carbon.

An exceptional phenomenon has been observed that SO2 and NOx in flue gas can be effectively adsorbed over activated carbon with a surprising capacity at cold temperatures with the presence of oxygen. In this study, the adsorption characteristics of NO and SO2 over activated carbon at 80, 20, 0, and - 20 is experimentally investigated. Without the presence of oxygen, adsorption of NO is negligible. In the presence of oxygen, NO can be oxidized to NO2 over activated carbon which leads to the co-adsorption of NO/NO2 within the adsorption bed. Catalytic oxidation of NO over activated carbon can be significantly enhanced at cold temperatures, leading to an extraordinary increase of adsorption capacity of NO. With an initial concentration of NO = 200 ppmv and a space velocity of 5000 h-1, the average specific capacity increases from 3.8 to 169.1 mg/g when the temperature decreases from 80 to - 20 â„ƒ. For NO-O2 co-adsorption, the specific capacity increases along the adsorption bed due to the increasing NO2 concentrations. The adsorption capacity of SO2 is also significantly enhanced at cold temperatures. With an initial concentration of SO2 = 1000 ppmv, the specific capacity increases from 12.9 to 123.1 mg/g when the temperature decreases from 80 to - 20 â„ƒ. A novel low-temperature adsorption (LAS) process is developed to simultaneously remove SO2 and NOx from flue gas with a target of near-zero emission. A pilot-scale testing platform with a flue gas flowrate of 3600 Nm3/h is developed and tested. Emission of both SO2 and NOx is less than 1 ppmv, and the predicted energy penalty is about 3% of the net generation.

Watt-level self-frequency-doubling Nd:GdCOB lasers.

Laser-diode (LD) pumped self-frequency doubling (SFD) Nd:GdCa4O(BO3)3 (Nd:GdCOB) miniature laser was demonstrated. The output power as high as 1.35 W was achieved which is over than five times than previous values for Nd:LnCa4O(BO3)3 (Ln=Y or Gd) SFD lasers and becomes the highest continuous-wave output power in this field to our knowledge. The maximum optical conversion efficiency is 17%. By comparison, we found that the cutting direction along its optimal phase-matching direction out of the principal planes is the determining factor resulting in this watt-level efficient output power. Different with previous studies, the emission wavelength is centered at about 545 nm. We believed that this efficient laser will become the most competitive one in the existing commercial green lasers, especially in the laser display, medical treatment and spectroscopic analysis etc.

Efficient triwavelength laser with a Nd:YGG garnet crystal.

We demonstrate a laser-diode pumped efficient triwavelength laser at about 1.06microm with a Nd-doped yttrium gallium garnet crystal for the first time, to our knowledge. Continuous wave output power of 7.15W was achieved under an absorbed pump power of 14.1W, corresponding to the slope efficiency of 52.7%. With Cr:YAG as the saturable absorber, passive Q-switching performance was obtained. The shortest pulse width, largest pulse energy, and highest peak power were obtained at 3.1ns, 153.8microJ, and 46.6kW, respectively. The laser spectrum was found to be a triwavelength, with respective wavelengths of 1062.1, 1060.3, and 1058.9nm, and three laser transitions were assigned.

Efficient two-photon excited amplified spontaneous emission from organic single crystals.

E, E-1, 4-bis[4'-(N,N-dibutylamino)styryl]-2,5-dimethoxy-benzene (DBASDMB) organic crystals with high crystalline quality, large size and excellent optical properties are prepared. The linear and nonlinear properties in the crystal are comparatively studied. The relaxation dynamics pumped by two-photon are very similar with that pumped by one-photon. The crystal exhibits very strong two-photon excited fluorescence and amplified spontaneous emission. Efficient two-photon absorption, reasonably high fluorescent quantum efficiency, and high crystal quality together with stimulated emission make organic crystals ideal for the application in frequency upconversion and other optoelectronic fields.

First-principles study of the electronic, optical properties and lattice dynamics of tantalum oxynitride.

First-principles calculations of the electronic, optical properties and lattice dynamics of tantalum oxynitride are performed with the density functional theory plane-wave pseudopotential method. The analysis of the electronic structure shows a covalent nature in Ta-N bonds and Ta-O bonds. The hybridization of anion 2p and Ta 5d states results in enhanced dispersion of the valence band, raising the top of the valence band and leading to the visible-light response in TaON. It has a high dielectric constant, and the anisotropy is displayed obviously in the lower energy region. Our calculation indicated that TaON has excellent dielectric properties along [010] direction. Various optical properties, including the reflectivity, absorption coefficient, refractive index, and the energy-loss spectrum are derived from the complex dielectric function. We also present phonon dispersion relation, zone-center optical mode frequency, density of phonon states, and some thermodynamic properties. The experimental IR modes (B(u) at 808 cm(-1) and A(u) at 863 cm(-1)) are reproduced well and assigned to a combination of stretching and bending vibrations for the Ta-N bond and Ta-O bond. The thermodynamic properties of TaON, such as heat capacity and Debye temperature, which were important parameters for the measurement of crystal physical properties, were first given for reference. Our investigations provide useful information for the potential application of this material.

Optical properties of the high-pressure phases of SnO(2): first-principles calculation.

We present a detailed investigation on the optical properties, including dielectric function, reflectivity, absorption, refractive index, and electron energy-loss spectrum, of the high-pressure phase SnO(2) in the rutile, pyrite, fluorite, and cotunnite structures by using the density functional theory (DFT) plane-wave pseudopotential method. The results indicate that with the increasing of pressure the band gaps become larger, the density of states are broader, so the curves of optical properties have a little blue shift. Except that the fluorite phase has some metallic properties, the other three phases exhibit excellent dielectric behavior. Interestingly, the fluorite and cotunnite SnO(2) phases always have some special characteristics, such as higher plasma frequency, which need further fundamental and application research.

Automatic microbial electro-Fenton system driven by transpiration for degradation of acid orange 7.

Microbial electro-Fenton system (MEFS) shows potential application for degradation of recalcitrant pollutants. In order to simplify the MEFS and adapt to the practical application situations, such as water, soil or sludge remediation, we developed an automatic MEFS (AMEFS) for degradation of a recalcitrant dye, acid orange 7. The AMEFS contained a microchannel-structured carbon decorated with iron oxides as electro-Fenton cathode. The AMEFS could be either two-electrode configuration that the microchannel-structured carbon connected with an additional bioanode by an external circuit, or single-electrode configuration that the microchannel-structured carbon served as both bioanode and cathode. Thanks to the microchannel structure of the carbon cathode, the AMEFS could be auto-driven by a process similar to the transpiration process of natural plants. The two-electrode AMEFS had higher degradation efficiency of acid orange 7 at lower external resistance, and achieved the highest degradation efficiency of 96% at the short-circuit condition. The single-electrode configuration simplified the setup of the AMEFS and possessed comparable performance with that of two-electrode configuration at short-circuit condition. Moreover, it could degrade high concentration acid orange 7 of up to 50 mg L-1 and achieve a high degradation efficiency of over 93%. The AMEFS could be applied for soil and sludge remediation by direct insertion of the microchannel structured carbon into contaminated body.

Continuous-wave and passively Q-switched laser performance with a disordered Nd:CLNGG crystal.

We demonstrated efficient high-power continuous-wave (cw) and passively Q-switched disordered Nd:CLNGG laser performance. In cw operations, the output power was obtained to be 3.81 W with a slope efficiency of 30.3%. To our knowledge, they are the highest cw power and efficiency with Nd:CLNGG as the gain medium and a laser-diode (LD) as the pump source. Recorded with a spectrum analyzer, no splitting was found in the Nd:CLNGG laser, which is different with that of its isomorph Nd:CNGG. The LD pumped passively Q-switched Nd:CLNGG laser was obtained for the first time to our knowledge. The shortest pulse width, largest pulse energy and highest peak power were achieved to be 12.3 ns, 199.1 microJ and 16 kW, respectively, with Cr(4+):YAG crystals as the saturable absorbers.

Passive mode-locking performance with a mixed Nd:Lu(0.5)Gd(0.5)VO(4) crystal.

Continuous-wave (cw) mode-locking of a diode-pumped Nd:Lu(0.5)Gd(0.5)VO(4) mixed crystal laser is reported for the first time to our knowledge with a simply compact three-mirror cavity. Stable pulses as short as 5.5 ps were generated at a repetition rate of 147 MHz. At the absorbed pump power of 16 W, a mode-locked laser with average output power of 5.31 W was obtained, giving an optical conversion efficiency of 33.2%, and a slope efficiency of 46.7%.

Various unique coordination patterns of Hg and DFT calculations to determine the formation of a 3-D supramoleculer framework by covalent and noncovalent interactions.

By combining a large pi-conjugated bidentate ligand L: 3,6-dipyrazole-N-ethylcarbazole with HgI(2), an extraordinary supramolecular coordination polymer, [Hg(4)L(2)I(8)](infinity), has been prepared. The crystal structures of the ligand and its coordination polymer were determined by X-ray crystallography, which shows three varied coordination modes especially the rare asymmetric quadruply bridged trinuclear moieties in [Hg(4)L(2)I(8)](infinity). Density functional theory (DFT) calculations (ADF) performed on model dimers show the roles of covalent and noncovalent interactions in establishing the three-dimensional architecture.

A photocatalytic reduction method for the preparation of TiO2 nanobelt supported noble metals (Ag, Au).

TiO2 nanobelts, with typical widths of 50 to 200 nm, thicknesses of 20-50 nm, supported noble metals (Ag, Au) are prepared by the photocatalytic reduction method. The as-made samples were characterized by Transmission electron microscopy (TEM), Field-emission scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS). The results show that silver particles, with the grain size of about 10 nm, deposited on the surface of nanobelts are uniform. And the grain size of Au on the surface of nanobelts is about 30 nm. In this method, the as-made TiO2 nanobelt is not only used as support, but also as photocatalyst to reduce the noble metal ions.

Growth and passively self-Q-switched laser output of new Nd3+,Cr5+:GdVO4 crystal.

A new passively self-Q-switched Nd, Cr:GdVO(4) laser crystal was grown by Czochralski method for the first time to our knowledge. Polarized absorption spectra were measured at room temperature. The absorption bands display polarization character and an absorption band of Cr(5+) ions at 1110 nm enables the crystal to be a self-Q-switched laser material at 1.06 mum. In the passive self-Q-switching operation, the maximum output power, shortest pulse width, and largest pulse energy were obtained to be 265 mW, 230 ns, and 1.12 microJ, respectively.