Functional mechanism on stem cells by tea(Camellia sinensis)bioactive compounds

Camellia sinensis(tea),one of the most popular commercial crops,is commonly applied in all parts of the world.The main active ingredients of tea include polyphenols,alkaloids,polysaccharides,amino acids,aroma and volatile constitutes,all of which are potentially responsible for the activities of tea.Stem cells(SCs)are the immature and undifferentiated cells by a varying capacity for proliferation,self-renewal and the capability to differentiate into one or more different derivatives with specialized function or maintain their stem cell phenotype.Herein,a thorough review is conducted of the functional mechanism on SCs by tea bioactive compounds.

Fluoridation routes,function mechanism and application of fluorinated/fluorine-doped nanocarbon-based materials for various batteries:A review

With the popularity and widespread applications of electronics,higher demands are being placed on the performance of battery materials.Due to the large difference in electronegativity between fluorine and carbon atoms,doping fluorine atoms in nanocarbon-based materials is considered an effective way to improve the performance of used battery.However,there is still a blank in the systematic review of the mechanism and research progress of fluorine-doped nanostructured carbon materials in various batteries.In this review,the synthetic routes of fluorinated/fluorine-doped nanocarbon-based(CF_x)materials under different fluorine sources and the function mechanism of CF_x in various batteries are reviewed in detail.Subsequently,judging from the dependence between the structure and electrochemical performance of nanocarbon sources,the progress of CF_x based on different dimensions(0D–3D)for primary battery applications is reviewed and the balance between energy density and power density is critically discussed.In addition,the roles of CF_x materials in secondary batteries and their current applications in recent years are summarized in detail to illustrate the effect of introducing F atoms.Finally,we envisage the prospect of CF_x materials and offer some insights and recommendations to facilitate the further exploration of CF_x materials for various high-performance battery applications.

Pyrolysis mechanism of glucose and mannose: The formation of 5-hydroxymethyl furfural and furfural

Fast pyrolysis of biomass will produce various furan derivatives, among which 5-hydroxymethyl furfural（5-HMF） and furfural（FF） are usually the two most important compounds derived from holocellulose. In this study, density functional theory（DFT） calculations are utilized to reveal the formation mechanisms and pathways of 5-HMF and FF from two hexose units of holocellulose, i.e., glucose and mannose. In addition, fast pyrolysis experiments of glucose and mannose are conducted to substantiate the computational results, and the orientation of 5-HMF and FF is determined by 13C-labeled glucoses. Experimental results indicate that C1 provides the aldehyde group in both 5-HMF and FF, and FF is mainly derived from C1 to C5 segment. According to the computational results, glucose and mannose have similar reaction pathways to form 5-HMF and FF with d-fructose（DF） and 3-deoxy-glucosone（3-DG） as the key intermediates. 5-HMF and FF are formed via competing pathways. The formation of 5-HMF is more competitive than that of FF, leading to higher yield of 5-HMF than FF from both hexoses. In addition, compared with glucose,mannose can form 5-HMF and FF via extra pathways because of the epimerization at C2 position. Therefore, mannose pyrolysis results in higher yields of 5-HMF and FF than glucose pyrolysis.

Microstructure and Mechanical Properties of ZrO_2-Ni Functionally Gradient Material

The fabrication. microstructure and mechanical properties of ZrO2-Ni functionally gradient materials (FGM ) have been studied. FGM as well as non-FG M of ZrO2-Ni system was developed by powder metallurgical process. X-ray diffractometer (XRD ). electron probe microanalyzer (EPMA), scanning electron microscope (SEM ) and optical microscope were employed to investigate the crystalline phases. chemical composition and microstructure Experimental results demonstrate that the composition and microstructure of ZrO2-Ni FGM have the expected gradient distribution. There are no distinct interfaces in the FGM due to the gradient change of components. that is, the constituents are continuous in microstructure everywhere. Moreover, Vickers hardness and flexural strength were measured for the common composites as a function of composition. It is made clear that the mechanical properties of the FGM vary corresponding to the constitutional changes as well

Mechanistic, Energetic and Structural Aspects of the Adsorption of Carmustine on the Functionalized Carbon Nanotubes

Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug carmustine with functionalized carbon nanotube（CNT） have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug carmustine with functionalized CNT is thermodynamically suitable. NTCOOH and NTCOCl can bond to the NH group of carmustine through OH（COOH mechanism） and Cl（COCl mechanism） groups, respectively. The activation energies, activation enthalpies and activation Gibbs free energies of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism, and therefore COCl mechanism is suitable for covalent functionalization. COOH functionalized CNT（NTCOOH） has more binding energy than COCl functionalized CNT（NTCOCl） and can act as a favorable system for carmustine drug delivery within biological and chemical systems（noncovalent）. These results could be generalized to other similar drugs.

Synthesis, Characterization, Thermal Decomposition Mechanism and Non-Isothermal Kinetics of Salicylaldehyde Salicylhydrazone and Its Complex of Erbium(Ⅲ)

The salicylaldehyde salicylhydrazone and its complex of Er(Ⅲ) were synthesized. The formulae K·4H_2O(HL=[C_(14)H_(10)N_2O_3]^(2-), the bivalent form of the salicylaldehyde salicylhydrazone) were determined by elemental analysis and EDTA volumetric analysis. Molar conductance, IR, UV and X-ray power diffraction were carried out for the characterizations of the complex and the ligand. There are two stable five-numbered and six-numbered circles in the complex. The thermal decompositions of the ligand and the complex with the kinetic study are carried out by non-isothermal thermogravimetry. The stages of the decompositions were identified by TG-DTG curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by the corresponding kinetic parameters.The activation energy value of the main step decomposition are also calculated by Kissinger′s method and Ozawa′s method.

Mechanism Research on the Function of Electric Warmed Needle

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The focal mechanism solution of the Ms6.5 Wuding earthquake in Yunnan Province of October 24,1995

The focal mechanism of Wuding earthquake with magnitude M =6.5 on October 24, 1995 is estimated by the method of inversion of seismic tensor in this paper. The two principal axes are nearly horizontal, the principal compressive axis is about N30°E, the nodal plane which strikes about N105°E (N75°W) is probably consistent with the actual rupture plane.

Influence of oxygen-rich hot air composite gas medium on sintering performance and function mechanism

Hot air sintering technology is used to improve the quality and production efficiency of sintered ore.However,the current thick layer condition highlights the disadvantage of the low oxygen potential of the hot air sintering layer.Therefore,it is considered to use oxygen enrichment sintering to improve the environment of hot air sintering.Traditional sintering,hot air sintering,and oxygen-rich hot air sintering were compared through sintering cup experiments,and the influence of hot air and oxygen-rich hot air on sintering indexes was clarified.Hot air reduced the vertical sintering velocity,while improved the yield and tumbler index.Oxygen-rich hot air sintering contributed to improving the vertical sintering velocity while ensuring the quality of sintered ore,thus comprehensively improving production efficiency.Under the action of hot air,the highest temperature of the sintering layer increased and the high-temperature holding time was prolonged.After oxygen enrichment,the combustion efficiency of fuels in the upper layer of materials was promoted,which optimized heat distribution in the middle and lower layers of materials and increased the content of calcium ferrite in the sintered ore,thus strengthening the sintering process.

A critical review on the health promoting effects of mushrooms nutraceuticals

Extensive elucidations focusing on the efficient health promoting properties and high nutritional values of mushrooms have been expanded dynamically from the past few decades.Due to its high quality of proteins,polysaccharides,unsaturated fatty acids,mineral substances,triterpenes sterols and secondary metabolites,mushrooms have always been appreciated for their vital role in protecting and curing various health problems,such as immunodeficiency,cancer,inflammation,hypertension,hyperlipidemia,hypercholesterolemia and obesity.Moreover,investigations in recent years have revealed the correlations between the health-promoting benefits and gut microbiota regulating effects induced by the mushrooms intake.Researches on the immense role in the nutritional and health benefits displayed by mushrooms have become an emergent task to study.The present article overviewed and compiled the latest information correlated to the health benefits and underlying functional mechanisms of mushroom nutraceuticals,and concluded that the supplementation of mushrooms as a dietary composition could become a natural adjuvant for the prevention and treatment of several health diseases.

Research advances in allelopathy of Quercus L.

The term allelopathy refers to biochemical interaction between all types of plants including microorganisms through production of chemical compounds that escape into the environment and exist widely in Quercus L. The development of investigations into types of allelochemicals, their compounding and spreading pathways, as well as expression of allelopathy in Quercus L. are reviewed in this paper： We have closely and systematically emphasized the functional mechanisms of allelopathy in forest plants for our next research project on allelopathy in Quercus L.

Effect of demethyltransferase FTO on tumor progression

N6-methyladenosine(m6A)modification is the most widespread and conserved internal mRNA modification in mammalian cells.It greatly affects genetic regulation by enhancing the involvement of diverse cellular enzymes and thus,plays a significant role in basic life processes.Numerous studies on m6A modification identified FTO as a crucial demethylase that participates in various biological processes.Not only does FTO play a pivotal role in obesity-related conditions,but it also influences the occurrence,development,and prognosis of several cancers,such as acute myeloid leukemia,breast cancer,liver cancer,and lung cancer.Moreover,FTO also shows a close association with immunity and viral infections.This article summarized the molecular mechanism of FTO in tumorigenesis and tumor progression.

Development and Evaluation of a New Nanometer Based Spacer NMS-I

In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the base stock to experimentally develop a new spacer system NMS-I, in combination with other materials, including a chemical gel plugging agent, carboxymethyl cellulose and barite. Experimental results indicated that the system had a wide adjustable range of density, good rheological property, static stability and compatibility with cement slurry. It also showed no flocculating or thickening effect on the water-base drilling fluid and low-density cement system. Meanwhile, the capacity of lost circulation control and the influence of the spacer on the second interfacial cementing strength were evaluated by a self-made lost circulation simulator and shearing test facility. The results showed that the spacer had favorable plugging and flushing effect, and the second interfacial cementing strength can be greatly improved. Moreover, based on the experiments, the mechanisms of spacer function were analyzed. The results obtained from the investigation offer a novel approach to resolving some practical problems in cementing jobs.

Structural and Mechanistic Studies of γ-Fe2O3 Nanoparticle as Capecitabine Drug Nanocarrier

Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been investigated.Quantum molecular descriptors of noncovalent configurations were studied.It was specified that binding of capecitabine onto γ-Fe2O3 nanoparticles is thermodynamically suitable.Hardness and the gap of energy between LUMO and HOMO of capecitabine are higher than the noncovalent configurations,showing the reactivity of capecitabine increases in the presence of γ-Fe2O3 nanoparticles.Capecitabine can bond to γ-Fe2O3 nanoparticles through OH（k1 mechanism）,NH（k2 mechanism）,CO（k3 mechanism） and F（k4 mechanism） groups.The activation energies,activation enthalpies and activation Gibbs free energies of these reactions were calculated.It was specified that the k1 and k2 mechanisms are under thermodynamic control and k3 and k4 under kinetic control.These results could be generalized to other similar drugs.

Moment tensor inversion of the November 6, 1988 MS=7.6, Lancang-Gengma, China,earthquake using long-period body-waves data

Moment tensor inversion was carried out to myert the source mechanism and source time function of the Ms=7.6November 6. 1988, Lancang-Gengma. Yunnan Province, Chin4 earthquake. Waveforms of long-period bodywaves recorded by China Digital Seismograph Network (CDSN) were used in the inversion. The inverted resultshows one nodal plane of right-lateral strike-slip faulting and another of left-lateral strike-slip faulting and a simplesource time function of a duration of about 15 s and scalar seismic moment of 6.4x 102oN-N-m From the geologicaldata and tectonic settings and also from field observations and epicentral distribution of aftershocks, the nodalplane striking in the azimuth of 313° is preferred as the fault plane. The pressure axis lies almost horizontally innorth-south direction.

Forced motion of an elastic filament through a narrow tube

A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined in a thermal environment, such a flexible strand may become tangled owing to its flexibility. When confined within a narrow ＂tube＂ over its full length, a flexible molecule may behave quite differently. Here, we consider the qualitative nature of deformation of an individual filament when confined within a tube. Commonly the tube is formed within the cluster by a large number of surrounding filaments of the same type.

Thermal Behavior,Sensitivity,Detonation Velocity and Pressure of a Nitrogen-Rich Compound

The nitrogen content of tetrazolo triazines is 68.9%.In this paper,tetrazolotriazines was synthetized.The TG-DSC test indicated its decomposition process in detail.The non-isothermal kinetic parameters were speculated by Kissinger and Ozawa methods.It revealed the mechanism function of thermal decomposition.The impact and friction sensitivity were tested.The detonation pressure and velocity were calculated.It has a wide range of potential applications as a kind of energetic material.

THE MECHANICAL METHOD OF CONSTRUCTING THE DISPLACEMENT FUNCTIONS IN ELASTICITY

In this Paper we have proven the general solution to the equations of linear operatorsAu=f as u=Cv+e . where v satisfies the equation Dv=g and D is adiagonal matrix. Basing on the consstructive proof of Hilbert Nullstellensat=. we haregiven the mechanical method of constucting C. D and e.and some of the mechanicalalgorithm displacement functions in elasticity are given by this method also .

CLIFFORD ALGEBRA,THEORY OF ITS FUNCTION AND THEIR APPLICATION TO MECHANICS

As is Wellknown in both elastic mechanics andfluid mechanics, the plane problems are more convenient than space problems. One of the causes is that there has been a complete theory about the complex Junction and the analytic junction, hut in space problems, the case is quite different.We have no effective method to deal with these problems. In this paper, we first introduces general theories of Clifford algebra. Then we emphatically explain Clifford algebra in three dimensions and establish theories of regular Junction in three dimensions analogically to analytic function in plane. Thus we extend some results of plane problem-la three dimensions or high dimensions. Obviously, it is very important for elastic and fluid mechanics. But because Clifford algebra is not a commutative algebra, we can't simply extend the results of two dimensions to high dimensions. The left problems are yet to be found out.

The effect of different doses of vecuronium on respiratoty function and mechanics during laparoscopic cholecystectomy

Objective To investigate the effects of different doses of vecuronium on ventilatory function and mechanics of breathing during elective laparoscopic cholecystectomy. Methods Sixty - three ASA Ⅰ - Ⅱ patients aged 29 -57 yr were randomly divided into 3 groups of twenty-one: group Ⅰ received vecuronium 1 ± ED95 , group Ⅱ 2 ± ED95 and group Ⅲ ± ED95. Patients with respiratory disease were excluded. The patients were premedicated with intramuscular scopolamine 0 . 3 mg and oral diazepam 0 . 1 mg· kg-1 . Anesthesia was induced with fentanyl 2 μg ·kg-1 ,propofol 2 mg·kg-1 and succinylcholine 1. 5 mg· kg-1 and maintained with 1.0% -1.5% isoflurance and intermittent iv boluses of propofol 1 mg·kg when needed. Vecuronium 1 ± ED95 ( group Ⅰ ) or 2 ± ED95 (group Ⅱ ) or 3 ± ED95 (group Ⅲ ) was given iv after succinylcholine when TOF showed that T1 】 70 % . The patients were mechanically ventilated. VT was set at 10 ml ·kg-1 and respiratory rate at 12 bpm. End-tidal PCO2 was maintained at 30 -