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OBJECTIVE: The objective of this study was to investigate the role of long noncoding RNAs small nucleolar RNA host gene 17 (SNHG17) in hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Here, the expression level of SHNG17 was determined using reverse-transcription quantitative PCR in tissue specimens and cell lines. The chi-squared test was used to analyze the associations between SNHG17 expression and clinical pathological factors in HCC patients. Kaplan-Meier and logrank analyses were used to evaluate the prognosis of HCC patients, and proportional hazards model (Cox) regression was utilized for univariate and multivariate analyses. Knockdown of SNHG17 was achieved by transfection with si-SNHG17 in HepG2 and SNU-182 cells. Cell function was analyzed using CCK-8 assay, colony formation assay, Flow cytometry analysis and transwell assays. RESULTS: Our data showed that SNHG17 expression was significantly upregulated in cancer regions of HCC compared with adjacent regions. Increased SNHG17 expression level was correlated with tumor size, TNM stage and poor survival prognosis in HCC patients. Further functional experiments indicated that inhibition of SNHG17 significantly inhibited HCC cell proliferation, migration and invasion, caused cell cycle G0/G1 phase arrest and apoptosis. CONCLUSIONS: In summary, our findings suggest that SNHG17 might function as novel therapeutic target for the treatment of HCC. [ABSTRACT FROM AUTHOR]

Q-rung orthopair uncertain linguistic sets (q-ROULSs) are a powerful tool for describing ambiguity and uncertainty of linguistic information. In this study, considering that in most multi-attribute group decision making (MAGDM) problems, not only the quantitative evaluation information of decision makers but also the qualitative evaluation opinions should be considered. Therefore, we develop a novel MAGDM method with unknown attribute weights under the q-rung orthopair uncertain linguistic environments. We firstly propose the cross-entropy of q-ROULSs, which is utilized to solve the optimal attribute weights by a linear programming model. In order to effectively summarize the unclear language information of q-ROULSs, we extend the power Muirhead mean (PMM) operator to q-ROULSs, and propose a family of q-rung othpair uncertain linguistic power Muirhead mean (q-ROULPMM) operators. The advantage of the PMM operator is that it not only mitigates the adverse effects of too high or too low attribute values on the results, but also takes into account the interrelationships between attribute values. At the same time, some ideal properties and special cases of the q-ROULPMM operator are also studied. Further, a new method based on the proposed cross-entropy and aggregation operators is developed for solving the MAGDM problem under q-ROULSs. Finally, we carried out numerical experiments to prove the effectiveness and superiority of the method. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aims to elucidate how sevoflurane affects the malignant progression of gastric cancer (GC) and its pharmacological mechanism. MATERIALS AND METHODS: Dose-dependent and time-dependent regulations of sevoflurane on proliferation inhibition rate in AGS and BGC-823 cells were examined, and thus the optimal dose and treatment time of sevoflurane on GC cells were selected. Subsequently, proliferative and migratory abilities in sevoflurane-induced AGS and BGC-823 cells (3.4% sevoflurane induction for 6 h) were detected by CCK8 and transwell assay, respectively. After sevoflurane induction, relative levels of miR-34a and TGIF2 in GC cells were determined by qRT-PCR and Western blot. Regulatory effects of miR-34a on GC cell phenotypes were also assessed. Furthermore, the in vivo function of miR-34a in GC growth was explored by generating xenografted GC in nude mice. RESULTS: Sevoflurane induction time-dependently and dose-dependently enhanced proliferation inhibition rate in AGS and BGC-823 cells. The proliferative and migratory abilities in GC cells induced with 3.4% sevoflurane for 6 h were markedly attenuated. sevoflurane induction upregulated miR-34a, but downregulated TGIF2 in GC cells. TGIF2 was negatively regulated by miR-34a. Notably, overexpression of miR34a inhibited proliferative and migratory abilities in sevoflurane-induced GC cells, and knockdown of miR-34a yielded the opposite results. In nude mice with xenografted GC tissues, sevoflurane treatment markedly reduced tumorigenic ability, which was improved by knockdown of miR-34a. CONCLUSIONS: Sevoflurane weakens proliferative and migratory abilities in GC by upregulating miR-34a and downregulating TGIF2. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Asthma is a chronic pulmonary inflammatory disease characterized by excessive infiltration of leukocytes into the respiratory tract. We explored the underlying mechanisms of mesenchymal stem cells (MSCs) in the treatment of allergic asthma using a rat model. MATERIALS AND METHODS: The rats were sensitized with ovalbumin (OVA) and an aluminium hydroxide emulsion, which were injected intraperitoneally, and then the sensitized rats were challenged with aerosolized OVA. Before the allergen challenge, the model rats were injected with MSCs and MSC-derived exosomes. At the same time, 2 out of the 6 groups of rats were injected with BML-284, a Wnt agonist. The degree of airway inflammation was determined by bronchoalveolar lavage fluid (BALF) and haematoxylin and eosin (H&E) staining; the degree of airway remodelling was assessed by Masson staining; Western blotting (WB) and real-time polymerase chain reaction (PCR) were performed to evaluate Wnt/β-catenin signalling pathway-related factors and the expression of epithelial-mesenchymal transition (EMT)-related proteins in lung tissues. RESULTS: We showed that among the rats that were sensitized and challenged with OVA, the injection of MSCs and MSC-derived exosomes significantly reduced the total number of cells and the number of immune cells in BALF, proliferation of goblet cells and collagen deposition. Moreover, the number of BALF cells and collagen deposition increased significantly after the injection of BML-284. WB and real-time PCR showed that MSCs and MSC-derived exosomes significantly inhibited airway remodelling and EMT by restricting the Wnt/β-catenin signalling pathway, while additional injection of BML-284 suppressed the effects of MSCs and their exosomes, increased the EMT of the airway epithelium and exacerbated airway remodelling. CONCLUSIONS: MSCs inhibit chronic allergic inflammation of the airway and reduce airway remodelling and EMT of the airway epithelium in the lungs of asthmatic rats. This process is partly attributed to the inhibition of the Wnt/β-catenin signalling pathway by MSC-derived exosomes. [ABSTRACT FROM AUTHOR]

The process of high energy electron acceleration along the surface of grating targets (GTs) that were irradiated by a relativistic, high-contrast laser pulse at an intensity $I=2.5\times 10^{20}~\text{W}/\text{cm}^{2}$ was studied. Our experimental results demonstrate that for a GT with a periodicity twice the laser wavelength, the surface electron flux is more intense for a laser incidence angle that is larger compared to the resonance angle predicted by the linear model. An electron beam with a peak charge of ${\sim}2.7~\text{nC}/\text{sr}$ , for electrons with energies ${>}1.5~\text{MeV}$ , was measured. Numerical simulations carried out with parameters similar to the experimental conditions also show an enhanced electron flux at higher incidence angles depending on the preplasma scale length. A theoretical model that includes ponderomotive effects with more realistic initial preplasma conditions suggests that the laser-driven intensity and preformed plasma scale length are important for the acceleration process. The predictions closely match the experimental and computational results. [ABSTRACT FROM AUTHOR]

Large-volume atmospheric dielectric-barrier discharges (DBD) are particularly useful for processing applications when they operate in their homogeneous mode. A vast majority of their theoretical studies is currently based on the hydrodynamic treatment in which electrons are assumed to be in equilibrium with the local electric field. Recognizing that this assumption is incorrect in the sheath region, we report the development of an electron-hybrid model to treat electrons kinetically and all other particles hydrodynamically. Through numerical examples, it is shown that the mainstream hydrodynamic model underestimates gas ionization and discharge current. Using the hybrid model, it is demonstrated that variation in the amplitude of the applied voltage does not significantly alter sheath characteristics in terms of the electric field and the electron mean energy. Also gas ionization in atmospheric DBD is found to be significant only over a short timescale of 1 μs. Compared with dc atmospheric pressure glow discharges, atmospheric DBD are shown to have a smaller electron mean energy and a larger sheath thickness. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Recent studies have revealed the important role of long noncoding RNAs (lncRNAs) in regulating the progression of tumorigenesis. Oral squamous cell carcinoma (OSCC) is a prevalent tumor in the world. This study aims to identify the specific mechanism of lncRNA CASC2 in alleviating the progression of OSCC. PATIENTS AND METHODS: CASC2 expression in OSCC cell lines and 40 paired OSCC samples were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). Moreover, in vitro functions of CASC2 in regulating the cellular behaviors of OSCC cells were identified by performing transwell assay, wound healing assay and proliferation assay. The underlying mechanism of CASC2 in mediating the progression of OSCC was explored by qRT-PCR and Western blot. RESULTS: CASC2 expression was remarkably downregulated in OSCC tissues compared with that in adjacent normal samples. Moreover, proliferation, invasion and migration were inhibited in OSCC cells overexpressing CASC2. CASC2 overexpression in OSCC cells downregulated CDK1 at both mRNA and protein levels in vitro. Besides, the expression of CDK1 in OSCC tissues was negatively correlated to the expression of CASC2. CONCLUSIONS: CASC2 suppresses the migration, invasion and proliferation of OSCC cells through downregulating CDK1, which may offer a new therapeutic intervention for OSCC patients. [ABSTRACT FROM AUTHOR]

Investigations of energy transfer of high intensity (I = 5 × 1019 W/cm2), ultrashort (<30 fs) Ti:Sa laser pulses to solid targets with a randomly rough surface have been performed. We investigated the influence of the target surface morphology on the efficiency of energy transfer of p- polarized laser pulses characterized by a very high contrast. Targets with a roughness σ larger than ∼20% of the laser wavelength proved to absorb a remarkably large fraction of energy reaching up to 70%, almost independent of the incidence angle. Numerical simulations of various interaction conditions are in agreement with the experimental data and confirm the effect of the target morphology and its surface parameters on the enhanced energy absorbed fraction. [ABSTRACT FROM AUTHOR]

The structural evolution and stratigraphic architecture of the Southern Lufeng Depression in the Pearl River Mouth Basin, South China Sea show two second-order sequences (SSQ1 and SSQ2) and nine third-order sequences (WSQ1-5 and ESQ1-4) within the Eocene rift-related successions. Based on integrated interpretations of seismic reflections, well logs and core data, five distinct tectono-stratigraphic patterns are identified: (1) the initial synrift-I sequence (WSQ1) of low tectonic subsidence, overfilled by alluvial fan or fan-delta deposits and volcanic deposits, with no clear systems tracts; (2) the climax synrift-I sequences (WSQ2–4) developed in response to rapid tectonic subsidence, generally consisting of a low-stand systems tract (LST), transgressive systems tract (TST) and high-stand systems tract (HST); (3) the late synrift-I sequence (WSQ5) characterised by a decreased tectonic subsidence rate, dominated by braided delta, deep and shallow lacustrine sediments, mainly constructed by TST and HST; (4) the early synrift-II sequences (ESQ1–2) rapidly filled by braided deltaic sandstone and mainly composed of TST and HST with less common LST units; and (5) the late synrift-II sequences (ESQ3–4), which are totally filled by braided deltaic system in a shallow-water lake setting, presenting typical imbricate clinoforms or sub-parallel seismic configurations, consisting of only TST and HST components. During the climax stage of synrift-I development, the depositional setting changed from a prominent shallow lake (WSQ2) to a deep-lucustrine with turbiditic deposits (WSQ3) and finally dominated by mostly braided deltaic-shallow lacustrine deposits (WSQ4); the HST occupies an increasing proportion from early to late. Furthermore, the stratigraphic patterns, especially LST units of the climax synrift-I stage, are significantly influenced by topographic variations and slope-break belt types in the hanging dip-slope. This study reveals that the spatial and temporal evolution of lacustrine depositional and stratigraphic patterns were significantly controlled by the interplay of tectonic subsidence and sediment supply, and provides a fundamental basis for predicting the favourable reservoirs and geometry of source rocks related to the general variability of Eocene rift-related tectonic subsidence in the Southern Lufeng Depression of the Pearl River Mouth Basin. Furthermore, the topographic responses of differential active fault-stepped patterns associated with magma intrusions, highlight the variability of relevant sequence architectures in the hanging dip-slope in lacustrine rift basins. [ABSTRACT FROM AUTHOR]

Athetis lepigone (Möschler) is a new agronomic pest which has caused serious damages to summer maize in China. In order to effectively monitor it, it is necessary to carry-out a worldwide investigation on its potential geographical distribution. In this study, we give two ecological niche models, Genetic Algorithm for Rule-set Production and Maximum Entropy (MaxEnt), to predict the potential geographical distribution of A. lepigone. The results indicate that the suitable areas for A. lepigone are mainly in China (Beijing, Tianjin, central and southern Hebei, northern Jiangsu, Shandong, most of Henan, northern Anhui, central and southern Shanxi, central and southern Shaanxi, small parts of north-west in Hubei, eastern Gansu, parts of Ningxia, western of Xinjiang and Dandong, and Liaoning) and other Asian countries (South Korea, North Korea and Japan). Parts of Europe (south-western Russia, Ukraine, Moldova, Romania, Hungary, Bulgaria, Slovenia, and Croatia, Bosnia and Herzegovina, Serbia, parts of Austria, western Poland, the Czech Republic, Germany, northern Italy, Denmark, western Lithuania, Latvia, Estonia, southern Finland and Sweden) are also highly suitable for A. lepigone. In addition, in the states of the USA including Michigan, New York, Chicago, Missouri, Ohio, Illinois and Indiana are also favourable for its occurrence although till now no reports about of this species has been recorded. A jackknife test in MaxEnt showed that the mean temperature of the driest quarter was the most important environmental variable affecting the distribution of this pest. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effects of dietary cellulase addition on improving the nutritive value of Chlorella for juvenile crucian carp Carassius auratus (initial body weight: 2.99 ± 0.02 g, mean ± SEM). Five isonitrogenous and isoenergetic experimental diets were formulated to contain 0.0 (control), 0.5, 1.0, 1.5 and 2.0 g kg−1 cellulase, respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish per fibreglass tank for 8 weeks. The results showed that weight gain, specific growth rate, feed intake and the trypsin activity in the anterior intestine increased with increasing dietary cellulase to 1.5 g kg−1 and then declined with further addition. However, the mRNA expression levels of Mrf4 and Myf5, the apparent digestibility coefficients for dry matter, protein, energy and the majority of amino acids, and the activity of lipase in the anterior intestine were highest in fish fed the 1.0 g kg−1 cellulase diet, and then tended to decline with further cellulase supplementation. In conclusion, the optimal dietary cellulase supplementation level was 1.0-1.5 g kg−1, which can improve growth performance, digestive activities and nutrient digestibility in crucian carp. [ABSTRACT FROM AUTHOR]

The effects of low- to high-angle (>30°) normal faults on sedimentary architectural units in the Eocene Wenchang Formation, Enping Sag, Pearl River Mouth Basin (PRMB), South China Sea were investigated utilising a high-quality 3D seismic data set and restored paleogeomorphology. It has been shown that sequence stratigraphic units and sedimentary architecture are significantly controlled by the low- to high-angle normal faults. The Wenchang Formation, a second-order sequence, can be subdivided into two para-second-sequences (the Lower and Upper Wenchang sequences, E2WLand E2WU) and seven third-order sequences (from base to top: SQ1∼SQ7). The low-angle fault confined sequence architecture of the Wenchang Formation is mainly characterised by lateral stacking with the ratio of the vertical subsidence (V) to horizontal slip (H) being reduced from 1/2 for E2WLto 1/6 for E2WU. In contrast, the high-angle fault confined sequence is characterised by vertical stacking with the ratio of V/H close to 1 for sequences SQ1 to SQ7. In the 3D seismic area, the features of sediment-dispersal pattern were interpreted based on an integrated analysis of paleogeomorphology, seismic reflection characteristics, stratal thickness distribution and multiple attribute clustering. The results show that the large-scale fan delta, belt-shape lacustrine deposit and bird-foot braided delta systems mainly developed in the low-angle fault confined sequences, whereas small-scale fan delta, rhombus-shaped lacustrine deposit and lobe-shaped braided delta systems inherited tectono-sedimentary architectures in the high-angle fault confined sequences. [ABSTRACT FROM AUTHOR]

DNA vaccine targeting delivery to DC represents one effective strategy to improve the immunogenicity of the vaccine. In a previous study, we developed a novel DC-targeting recombinant protein that can deliver plasmid DNA to DCs by an electrostatic coupling effect and can thus improve the uptake efficiency of DCs, improving the expression of plasmid DNA in DCs. In this study, we coupled the protein with the HBV DNA vaccine pSVK- HBVA and investigated whether the immunogenicity and antiviral ability of the vaccine can be improved in HBV transgenic mice. The results show that a stronger specific immune response can be induced in mice after immunization with the coupling vaccine. The HBV DNA copy number and circulating antigen HBsAg in the serum of HBV transgenic mice were significantly decreased. Therefore, this study has demonstrated that the DC-targeting protein has the ability to improve the immunogenicity and the antiviral activity of the HBV DNA vaccine pSVK- HBVA. These findings indicate that this DC-targeting protein can be a potential method for the delivery of DNA vaccines directly to DCs. [ABSTRACT FROM AUTHOR]

Hydrogen production from ethanol solution (ethanol/water) by pulsed spark discharge was optimized by varying the volume of ethanol solution (liquid volume). Hydrogen yield was initially increased and then decreased with the increase in solution volume, which achieved 1.5 l/min with a solution volume of 500 ml. The characteristics of pulsed spark discharge were studied in this work; the results showed that the intensity of peak current, the rate of current rise, and energy efficiency of hydrogen production can be changed by varying the volume of ethanol solution. Meanwhile, the mechanism analysis of hydrogen production was accomplished by monitoring the process of hydrogen production and the state of free radicals. The analysis showed that decreasing the retention time of gas production and properly increasing the volume of ethanol solution can enhance the hydrogen yield. Through this research, a high-yield and large-scale method of hydrogen production can be achieved, which is more suitable for industrial application. [ABSTRACT FROM AUTHOR]

It is extremely challenging to measure first-order rate coefficients for soil nitrate transformation processes directly, either in the laboratory or in the field. In this study, an improved inverse method was proposed to optimize the first-order rate coefficients by considering the intermediate changing processes of the integrated functions. A numerical experiment was designed to test the accuracy of the method in optimizing the coefficients. Comparisons between the optimized and theoretical results indicated that all the relative errors were within 10%. Data collected from a field experiment were used to validate the optimization procedure and to demonstrate its applications in practice. Using the established model and the estimated values by the inverse method, the simulated sourcesink term (SST) distributions of September 2-12, 2007, were in good agreement, with the root mean squared error (RMSE) between them being as low as 0.00021 mg cm-3 d-1. Based on the established nitrate transformation model, the distributions of soil water content and nitrate concentration during September 2-12, 2007, were simulated, and compared well with the measured profiles, with the RMSE of 0.023 cm³ cm-3 and 0.017 mg cm-3, respectively. The improved inverse method should be useful for optimizing the firstorder rate coefficients for nitrate transformation, establishing the nitrate transformation model, and simulating the nitrate transport in the soil-plant system. [ABSTRACT FROM AUTHOR]

The far-field sound radiation behavior of a circular cylindrical shell submerged at finite depth from the free surface is studied. Based on the Flügge shell theory and the Helmholtz equation, the structure-acoustic coupling equation is established. An image method is applied so that the sound boundary condition of the free surface can be satisfied. Analytical expression of the far-field sound pressure is obtained using the stationary phase method and the Graf's addition theorem. In order to evaluate the effect of the submerged depth on sound radiation, the results of the submerged cylindrical shell at finite depth from the free surface are compared with those of the submerged cylindrical shell in the infinite fluid. The characteristics of the far-field sound pressure with the change of the depth are investigated. It is found that the submerged depth has a significant influence on the far-field sound pressure radiated from the submerged cylindrical shell due to the free surface effects. The work provides more understanding on the sound radiation properties of the submerged circular cylindrical shell without assuming infinite fluid field, which was commonly used in previous studies. [ABSTRACT FROM AUTHOR]

The effect of fluid viscosity and material parameters of the damping layer on the natural frequency characteristics of a circular cylindrical shell covered with free damping layer immersed in a viscous acoustic medium is studied in the present paper. An equivalent method is applied to the damping layer coated on the surface of the cylindrical shell. Then, the wave equation for viscous flow field derived from the linear equations of continuity, Navier-Stokes and state, the Flügge's thin shell theory for the isotropic, elastic, thin cylindrical shell and the appropriate wave harmonic field expansions in association with the pertinent boundary conditions are employed to get the equations of motion and the characteristic equation in the coupled system. Subsequently, numerical analysis is applied to solve the characteristic equation for the coupled system at various material parameters and viscosity coefficients, the influence of which can be illustrated by the calculation results. [ABSTRACT FROM AUTHOR]

The present study explores an electrochemical surface modification process to improve the corrosion resistance of Fe-24Mn-4Al-5Cr alloy. The effects of transpassive aging potential and time on the corrosion resistance, composition and stability of the passive film formed on an Fe-24Mn-4Al-5Cr alloy in 1M Na2SO4 solution were studied using combined electrochemical measurements, Auger electron spectroscopic and X-ray photoelectron spectroscopic analysis. The passivation of Fe-24Mn-4Al-5Cr alloy in 1M Na2SO4 solution was performed under the optimal parameters of critical potential of 1100 mV and for a passivation time of 30 min. The corrosion resistance in 1M Na2SO4 solution of Fe-24Mn-4Al-5Cr alloy modified by this treatment is superior to that of Fe-13Cr-0·1C stainless steel. Auger electron spectroscopic and X-ray photoelectron spectroscopic depth profiles of the passive film formed on the alloy using this treatment show Al2O3 and Cr2O3 enrichment together with Fe and Mn depletion in the passive film. This compositional change provides the increase in stability and in corrosion resistance of the alloy. [ABSTRACT FROM AUTHOR]

The status of cellular immunity has been shown to be associated with the occurrence and development of sepsis. Accumulating evidence has demonstrated that tumor necrosis factor-α-induced protein 8 like-2 (TIPE2) plays an important role in maintaining homeostasis of immune function. The present study, with the use of a controlled in vivo approach, demonstrated the effect of TIPE2 on cell-mediated immunity of CD4+ T lymphocytes in thermal injury murine model. One hundred and twenty-eight male mice were randomly allocated into four groups, which were sham burn group (n=48), burn group (n=48), burn with Ientivirus-RNAi-TIPE2 transfection group (n=16), burn with negative control transfection group (n=16), and they were sacrificed at the designated time points. CD4+ T lymphocytes were isolated from the spleen using MACS microbeads. Phenotypes were analyzed by flow cytometry analysis, and cytokines were determined using ELISA kits. We found that the expression of TIPE2 was markedly increased in CD4+T lymphocytes in mice at 24,48 and 72 hours postburn. Down-regulation of TIPE2 by lentivirus-RNAi-TIPE2 attenuated the suppressive effect of CD4+T lymphocytes, which was associated with profound elevation of nuclear factor of activated T cell (NF-AT) activity. These results demonstrate that TIPE2 appear to be involved in the immune regulation of CD4+T lymphocytes, and the decrease in TIPE2 expression on CD4+T lymphocytes in vivo can enhance peripheral T lymphocyte function after thermal injury. These data might provide a valid strategy to prevent the development of immunosuppressive state resulted from major burns. [ABSTRACT FROM AUTHOR]

Passive films of a high nitrogen face-centered-cubic (f.c.c.) phase (γN) formed on the plasma-based low-energy nitrogen ion implanted AISI 316L austenitic stainless steel with no pitting corrosion in 3.5 % NaCl aqueous solution were investigated by using electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis. The protective passive films on the γN phase layer were obtained as n-type and p-type semiconductors in the potential range above and below the flat band potential, respectively, which corresponded to the two regions structure: the iron hydroxide/oxides in the outer region and the chromium hydroxide/oxides and iron oxides accompanying the chromium and iron nitrides in the inner region. The γN phase layer has a maximal phase angle of 83° with an impedance slope of about -0.91 over a wider frequency range approximately from 10-2 Hz to 105 Hz. The donor and acceptor densities of the γN phase layer decreased approximately from 2.4 x 1021/cm³ to 6.9 x 1018/cm³ and from 2.9 x 1021/cm to 5.2 x 1019/cm³, and the fiat band potential decreased approximately from -547 mV(SCE) to -669 mV(SCE), relative to that of the original austenitic stainless steel. The nitrogen beneficial effect in the γN phase layer on the pitting corrosion resistance contributed to inhibiting the adsorption of aggressive chloride ions in the outer n-type iron hydroxide/oxides region, to restricting the migration of space charges as a complete barrier from the n-type and p-type semiconductors regions, and to neutralizing of the protons due to the formation of ammonia in NaCl solution. [ABSTRACT FROM AUTHOR]

It is demonstrated that the Cartesian momenta and positions offer a proper description for the motion of particles constrained on the surface of a sphere. In classical limit, their mean values on the classical wave packet go over to classical quantities. [ABSTRACT FROM AUTHOR]

Based on our experience in kinetic modeling of coupled multiple metabolic pathways, we propose a generic rate equation for the dynamical modeling of metabolic kinetics. It is symmetric for forward and backward reactions. Its Michaelis-Menten-King-Altman form makes the kinetic parameters (or functions) easy to relate to experimental values in the database and to use in computation. In addition, such a uniform form is ready to arbitrary number of substrates and products with different stiochiometry. We explicitly show how to obtain such rate equations rigorously for three well-known binding mechanisms. Hence, the proposed rate equation is formally exact under the quasi-steady state condition. Various features of this generic rate equation are discussed. In particular, for irreversible reactions, the product inhibition which directly arises from enzymatic reaction is eliminated in a natural way. We also discuss how to include the effects of modifiers and cooperativity. [ABSTRACT FROM AUTHOR]

Electrochemical anodic passivation of Fe–24Mn–4Al–5Cr non-magnetic alloy in 1 mol L-1 Na2SO4 solution has been used to modify the corrosion resistance of the alloy. The improved corrosion resistance of the Fe–24Mn–4Al–5Cr alloy was investigated by electrochemical measurement in 1 mol L-1 Na2SO4 solution, and by Auger electron spectroscopy/X-ray photoelectron spectroscopy (AES/XPS) analyses. As the anodic aging time in 1 mol L-1 Na2SO4 solution increases from 15 min to 5 h at a potential of 620 mV(SCE), the potential decay time from the passive to active state in 1 mol L-1 Na2SO4+0·5 mol L-1 H2SO4 solution increases from ∼230 to ∼2800 s the decay time also increases with more negative anodic aging potential. Anodic polarisation measurements in 1 mol L-1 Na2SO4 solution show that performance the passive current density of the anodically passivated layer decreases while its corrosion potential increases, to values superior to those of 1Cr13 stainless steel. The Al and Cr contents are enriched and the Fe and Mn contents are simultaneously depleted within the anodically passivated layer formed in 1 mol L-1 Na2SO4 solution. The effect of anodic passivation aging on the structure and chemical state, and corresponding corrosion resistance of the anodically passivated layer mainly depend on the anodic aging time, anodic aging potential and oxidising power of the electrolyte. [ABSTRACT FROM AUTHOR]

We demonstrate here that the potential can coexist with limit cycle in nonlinear dissipative dynamics, where the potential plays the driving role for dynamics and determines the final steady state distribution in a manner similar to other situations in physics. First, we show the existence of limit cycle from a typical physics setting by an explicit construction: the potential is of the Mexican-hat shape, the strength of the magnetic field scales with that of the potential gradient near the limit cycle, and the friction goes to zero faster than that of potential gradient when approaching to the limit cycle. The dynamics at the limit cycle is conserved in this limit. The diffusion matrix is nevertheless finite at the limit cycle. Second, based on the physics knowledge, we construct the potential in the dynamics with limit cycle in a typical dynamical systems setting. Third, we argue that such a construction can be, in principle, carried out in a general situation combined with a novel method. Our present result may be useful in many applications, such as in the discussion of metastability of limit cycle and in the construction of Hopfield potential in the neural network computation. [ABSTRACT FROM AUTHOR]

Based on the dynamical structure theory for complex networks recently developed by one of us and on the physical-chemical models for gene regulation, developed by Shea and Ackers in the 1980's, we formulate a direct and concise mathematical framework for the genetic switch controlling phage λ life cycles, which naturally includes the stochastic effect. The dynamical structure theory states that the dynamics of a complex network is determined by its four elementary components: The dissipation (analogous to degradation), the stochastic force, the driving force determined by a potential, and the transverse force. The potential may be interpreted as a landscape for the phage development in terms of attractive basins, saddle points, peaks and valleys. The dissipation gives rise to the adaptivity of the phage in the landscape defined by the potential: The phage always has the tendency to approach the bottom of the nearby attractive basin. The transverse force tends to keep the network on the equal-potential contour of the landscape. The stochastic fluctuation gives the phage the ability to search around the potential landscape by passing through saddle points. With molecular parameters in our model fixed primarily by the experimental data on wild-type phage and supplemented by data on one mutant, our calculated results on mutants agree quantitatively with the available experimental observations on other mutants for protein number, lysogenization frequency, and a lysis frequency in lysogen culture. The calculation reproduces the observed robustness of the phage λ genetic switch. This is the first mathematical description that successfully represents such a wide variety of major experimental phenomena. Specifically, we find: (1) The explanation for both the stability and the efficiency of phage λ genetic switch is the exponential dependence of saddle point crossing rate on potential barrier height, a result of the stochastic motion in a landscape; and (2) The positive feedback of cI repressor gene transcription, enhanced by the CI dimer cooperative binding, is the key to the robustness of the phage λ genetic switch against mutations and fluctuations in kinetic parameter values. [ABSTRACT FROM AUTHOR]

Resonant soft X-ray scattering spectra of a La[sub 0.5]Ca[sub 0.5]MnO[sub 3] thin film were measured at varying energies of the incident photon beam across Mn 2p thresholds. The data are analyzed within the framework of the Anderson impurity model and full multiplet theory. The scattering profiles of the film are reasonably well reproduced by model calculations for the Mn[sup 3+] system, in contrast to the absorption spectrum at the Mn L[sub 2,3] edge for which the contribution of the Mn[sup 4+] sublattice is required to be taken into account. The obtained agreement between calculations and experiment indicates that in this case resonant inelastic scattering mainly probes the local electronic structure at the Mn[sup 3+] sites in the La[sub 0.5]Ca[sub 0.5]MnO[sub 3] film. In turn, Mn[sup 4+] sites mainly contribute to ordinary L[sub α,β] X-ray emission due to relaxations in the intermediate state of the spectroscopic process. Such a situation can occur when the system favors a phase separation rather than checkerboard charge ordering of Mn[sup 3+] and Mn[sup 4+] sites. [ABSTRACT FROM AUTHOR]

This paper presents a systematic study of two series of carbosilane liquid crystalline (LC) dendrimers from first to fifth generations bearing 8, 16, 32, 64 and 128 terminal chiral mesogenic groups, respectively. All the LC dendrimers synthesized are characterized by the same glass transition temperature around -5°C. It has been shown that the LC dendrimers of the lower generations (G-1-G-3) form a ferroelectric SmC* phase over a very broad temperature range up to about 180°C, while the LC dendrimers of the higher generations (G-4 and G-5) display a rectangular columnar mesophase (Col[sub r]). Schemes of packing in the SmC* and Col[sub r] mesophases formed by the LC dendrimers are suggested and discussed. Electrical measurements on the ferroelectric LC dendrimers have shown that an increase in generation number leads to a decrease in the value of the spontaneous polarization and an increase in switching time. [ABSTRACT FROM AUTHOR]