MiR-206-mediated dynamic mechanism of the mammalian circadian clock

<p>Abstract</p> <p>Background</p> <p>As a group of highly conserved small non-coding RNAs with a length of 21~23 nucleotides, microRNAs (miRNAs) regulate the gene expression post-transcriptionally by base pairing with the partial or full complementary sequences in target mRNAs, thus resulting in the repression of mRNA translation and the acceleration of mRNA degradation. Recent work has revealed that miRNAs are essential for the development and functioning of the skeletal muscles where they are. In particular, miR-206 has not only been identified as the only miRNA expressed in skeletal muscles, but also exhibited crucial roles in regulation of the muscle development. Although miRNAs are known to regulate various biological processes ranging from development to cancer, much less is known about their role in the dynamic regulation of the mammalian circadian clock.</p> <p>Results</p> <p>A detailed dynamic model of miR-206-mediated mammalian circadian clock system was developed presently by using Hill-type terms, Michaelis-Menten type and mass action kinetics. Based on a system-theoretic approach, the model accurately predicts both the periodicity and the entrainment of the circadian clock. It also explores the dynamics properties of the oscillations mediated by miR-206 by means of sensitivity analysis and alterations of parameters. Our results show that miR-206 is an important regulator of the circadian clock in skeletal muscle, and thus by study of miR-206 the main features of its mediation on the clock may be captured. Simulations of these processes display that the amplitude and frequency of the oscillation can be significantly altered through the miR-206-mediated control.</p> <p>Conclusions</p> <p>MiR-206 has a profound effect on the dynamic mechanism of the mammalian circadian clock, both by control of the amplitude and control or alteration of the frequency to affect the level of the gene expression and to interfere with the temporal sequence of the gene production or delivery. This undoubtedly uncovers a new mechanism for regulation of the circadian clock at a post-transcriptional level and provides important insights into the normal development as well as the pathological conditions of skeletal muscles, such as the aging, chronic disease and cancer.</p

The progress of TMT Laser Guide Star Facility

The Laser Guide Star Facility (LGSF) is responsible for generating the artificial laser guide stars required by the TMT Laser Guide Star (LGS) AO systems. The LGSF uses multiple sodium lasers to generate and project several LGS asterisms from a laser launch telescope located behind the TMT secondary mirror. The LGSF includes 3 main subsystems: (1) the laser system, (2) the beam transfer optics (BTO) system, (3) the associated laser safety system. At present, the LGSF is in the preliminary design phase. During this phase, the laser launch telescope trade study, Beam transfer optical path trade study are compared carefully, and some critical components prototypes have been carried out to verify the requirements, such as the polarization status control and test, the Fast Steer Mirror (FSM) prototype test

The progress of TMT Laser Guide Star Facility

The Laser Guide Star Facility (LGSF) is responsible for generating the artificial laser guide stars required by the TMT Laser Guide Star (LGS) AO systems. The LGSF uses multiple sodium lasers to generate and project several LGS asterisms from a laser launch telescope located behind the TMT secondary mirror. The LGSF includes 3 main subsystems: (1) the laser system, (2) the beam transfer optics (BTO) system, (3) the associated laser safety system. At present, the LGSF is in the preliminary design phase. During this phase, the laser launch telescope trade study, Beam transfer optical path trade study are compared carefully, and some critical components prototypes have been carried out to verify the requirements, such as the polarization status control and test, the Fast Steer Mirror (FSM) prototype test

Industry experiment & effect of oxidation resistance coating for steel slab

Spraying test were conducted twice before steel slabs were put into the furnace and the effects of the oxidation resistance coating were investigated and verified.By comparing the change of slab weight,rolling force of the roughing mill & finishing mill,thickness of oxide film on the surface slabs by an XL-30 SEM and acid pickling speed of slabs with and without coating,it was found that the oxidization waste in the furnace decreased by 40 percent with the use of the coating and the corresponding yield capacity could increase by 0.2 percent at least.Besides,the thickness of oxide scale film on hot rolled products was reduced by 1.44 micrometers and the acid pickling time was shortened by 6s with the coating technology,while the total rolling force of RM & FM did not changed.Furthermore,the application prospect of this technology was also discussed in this paper

preparationandpropertiesofantioxidationinorganicnanocoatingforlowcarbonsteelatanelevatedtemperature

A new kind of anti-oxidation inorganic nano-coating for the common low carbon steel was prepared. It included magnesite mineral, metallurgic dust and silicate adhesive as the main raw materials. The nano-coating could be sprayed directly onto the low carbon steel slab even though with hot surface as far as under 1000 degrees c. And at the same time, a compact thin nano-film was formed, and the film would inhibit the oxygen into the interface of the steel body and decrease the loss of weight because of oxidation. The loss was decreased by about 60% or more. The properties and mechanism of oxidation resistance of the coating were discussed through XRD, TC-DTA and SEM. The experimental results show that many reactions would happen among the components of the coating and then many microspheres with the size of 80-100 nm generated in the system. By using the heat of the steel body, the silicate adhesive would interact with the microspheres, and the other components of the coating would be soft and sintered so that when the coating was sprayed onto the suface of the steel slab, the intact and compact film could beformed and adhesive with the steel body. Besides the special properties of anti-oxidation, the coating could prevent the volatilization of microelement in the steel such as silicate and carbon at a high temperature. So it can improve the quality and output of steel with this new kind of nano-coating

Effects of ammonium citrate additive on crystal morphology of aluminum phosphate ammonium taranakite

In this communication, we demonstrated the growth of aluminum phosphate ammonium taranakite (NH(4)-AlPO(4)) crystals from regular hexagonal form into the disk-like form could be controlled by ammonium citrate (AMC) as the effective crystal growth modifier at 90 degrees C. Prepared crystals were characterized by field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of AMC's concentration on the crystal form and morphology of NH(4)-AlPO(4) were studied. The results showed that the AMC's concentration is an important parameter to control the size and morphology of NH(4)-AlPO(4) crystal. The formation mechanism of the special morphology of NH(4)-AlPO(4) crystals was also analyzed. (C) 2009 Elsevier B.V. All rights reserved

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

A new kind of anti-oxidation inorganic nano-coating for the common low carbon steel was prepared. It included magnesite mineral, metallurgic dust and silicate adhesive as the main raw materials. The nano-coating could be sprayed directly onto the low carbon steel slab even though with hot surface as far as under 1000 degrees c. And at the same time, a compact thin nano-film was formed, and the film would inhibit the oxygen into the interface of the steel body and decrease the loss of weight because of oxidation. The loss was decreased by about 60% or more. The properties and mechanism of oxidation resistance of the coating were discussed through XRD, TC-DTA and SEM. The experimental results show that many reactions would happen among the components of the coating and then many microspheres with the size of 80-100 nm generated in the system. By using the heat of the steel body, the silicate adhesive would interact with the microspheres, and the other components of the coating would be soft and sintered so that when the coating was sprayed onto the suface of the steel slab, the intact and compact film could beformed and adhesive with the steel body. Besides the special properties of anti-oxidation, the coating could prevent the volatilization of microelement in the steel such as silicate and carbon at a high temperature. So it can improve the quality and output of steel with this new kind of nano-coating.A new kind of anti-oxidation inorganic nano-coating for the common low carbon steel was prepared. It included magnesite mineral, metallurgic dust and silicate adhesive as the main raw materials. The nano-coating could be sprayed directly onto the low carbon steel slab even though with hot surface as far as under 1000 degrees c. And at the same time, a compact thin nano-film was formed, and the film would inhibit the oxygen into the interface of the steel body and decrease the loss of weight because of oxidation. The loss was decreased by about 60% or more. The properties and mechanism of oxidation resistance of the coating were discussed through XRD, TC-DTA and SEM. The experimental results show that many reactions would happen among the components of the coating and then many microspheres with the size of 80-100 nm generated in the system. By using the heat of the steel body, the silicate adhesive would interact with the microspheres, and the other components of the coating would be soft and sintered so that when the coating was sprayed onto the suface of the steel slab, the intact and compact film could beformed and adhesive with the steel body. Besides the special properties of anti-oxidation, the coating could prevent the volatilization of microelement in the steel such as silicate and carbon at a high temperature. So it can improve the quality and output of steel with this new kind of nano-coating

CrOx-CeO2 binary oxide as a superior catalyst for NO reduction with NH3 at low temperature in presence of CO

CrOx/CeO2 catalysts supported on porous silica sphere have been prepared and characterized by N-2-BET, XRD, XPS, H-2-TPR and NH3-TPD methods. The effects of the molar ratio between CrOx and CeO2 in the catalysts for NOx selective catalytic reduction with ammonia were studied. It was indicated by the results that high NOx conversion (98%) could be obtained by the catalyst with proper Cr/Ce molar ratio (25/75) at 150 degrees C (W/F = 0.25 g s/cm(3)). The result might be contributed to the redox property and NH3-chelate ability of the CrOx-CeO2 binary oxide in the catalysts. (C) 2010 Elsevier B.V. All rights reserved

A glass-based protective coating on stainless steel for slab reheating application

A protective SiO(2)-Al(2)O(3)-Na(2)O glass-based coating for slab reheating application was deposited on AISI 304 stainless steel by air spraying, and its effect on high-temperature oxidation behavior of AISI 304 was investigated. Isothermal oxidation of bare and coated specimens was carried out at 1250A degrees C in air. The results showed that the glass coating could markedly decrease weight gain of AISI 304 by 91.7% after exposure of 9 h, minimize high-temperature scaling, and enhance steel surface quality. The protective effect is attributed to the formation of molten glass layer on steel surface at high temperature, which acts as an effective oxygen diffusion barrier. This glass-based protective coating by low-cost and easily handling method is potentially applicable in a slab reheating process

J. Phys. Chem. C

Raspberry-like hollow SiO2 spheres were synthesized successfully through a dual latex-surfactant templating route. In this approach, cationic cetyltrimethylammonium (CTA(+)) micelles and microscale polystyrene (PS) latex were employed as structure-directing templates for constructing the inorganic hollow SiO2 spheres with hierarchical structures. The final product has been analyzed scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), single-angle X-ray diffraction (SAXRD), Brunauer-Emmett-Teller (BET) measurements, and Hg porosimetry measurements. The as-obtained hollow SiO2 spheres present a novel raspberry-like protruding surface morphology and possess hierarchical porous shells. Moreover, the factors that could impact the surface morphology and hierarchical porous structure are discussed, and the corresponding mechanism was proposed accordingly. This dual templating route is expected to be an effective means to pattern multiscale structures in the shell of the SiO2 microspheres; hence their potential applications could be greatly broadened.Raspberry-like hollow SiO2 spheres were synthesized successfully through a dual latex-surfactant templating route. In this approach, cationic cetyltrimethylammonium (CTA(+)) micelles and microscale polystyrene (PS) latex were employed as structure-directing templates for constructing the inorganic hollow SiO2 spheres with hierarchical structures. The final product has been analyzed scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), single-angle X-ray diffraction (SAXRD), Brunauer-Emmett-Teller (BET) measurements, and Hg porosimetry measurements. The as-obtained hollow SiO2 spheres present a novel raspberry-like protruding surface morphology and possess hierarchical porous shells. Moreover, the factors that could impact the surface morphology and hierarchical porous structure are discussed, and the corresponding mechanism was proposed accordingly. This dual templating route is expected to be an effective means to pattern multiscale structures in the shell of the SiO2 microspheres; hence their potential applications could be greatly broadened