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Based on the open source code OpenFOAM, a three-dimensional model is presented for simulation of the interaction between waves and rubble mound breakwater with armor units. The armor units with their real geometries are depicted through computational grids. The volume-averaged RANS equation and the seepage equation containing nonlinear term are used to describe the percolation in the core and underlayer of the breakwater. Grids independence analysis are carried out, the horizontal and vertical grid size are recommended to take as one-fifteenth of the mean nominal diameter D50 of the armor units and one-fifteenth of the wave height respectively. Random wave overtopping of rubble mound breakwater with armor units is simulated through the proposed model. The results show good agreement between the simulated and measured overtopping discharge rates for different types of armor units. The developed numerical model can be used to evaluate the random wave overtopping in design of rubble mound breakwater with artificial armor blocs.

Many titanium-oxo clusters (TOCs) with various structure types have been reported, but research on co-crystallized TOCs still remains very rare. Herein, we successfully isolated heterometallic {Ti8Ni4+ Ti4Ni2} with co-crystal arrangement. Because of the Ni-to-TiO and Ti4Ni2-to-Ti8Ni4 charge transfer, cluster {Ti8Ni4+ Ti4Ni2} shows wide light absorption and narrow band gap based on the ultraviolet-visible spectra and density functional theory calculations. Moreover, the cluster co-crystallization and more metal centers in cluster {Ti8Ni4+ Ti4Ni2} endow it with better photocurrent response and photocatalytic hydrogen evolution activity than {Ti4Ni2} alone. This work not only provides a new model for co-crystallized TOCs but also stimulates research interest in their photochemical performances.

The Three Gorges Project (TGP) has changed the flow-sediment process in the middle Yangtze River. For navigation purposes, there is an urgent need to study the changes of the river regime over a long-term period and the shoal-channel evolution over different seasons since the completion of the TGP. Based on analysis of the measured data and the results of a two-dimensional mathematical model, the changes of the river regime and river bed evolution in the Yaojian reach downstream of the TGP were studied. Results show that a high sediment transport flux helps to keep the main flow in the North Branch, while a low sediment transport flux helps to keep the main flow in the South Branch. Thus, the main branch will not change in the near future because of the low sediment transport load. In this study, the flow-sediment process adjusted by the TGP was restored to the conditions before the TGP, and the river bed evolution under the adjusted and non-adjusted flow-sediment conditions was calculated. After the completion of the TGP, the reservoir storage accelerated the flood recession process and decreased the erosion by 11.9% under the flow-sediment conditions in 2010, and the deposition in the flood season decreased by 56.4%.

The cytochrome P450 enzymes (P450s or CYPs) are heme-containing enzymes which catalyze a wide range of oxidation reactions in nature. In our previous study, a rare multifunctional P450 AstB was found, which can dually oxidize two methyl groups (C-19 and C-21) of preasperterpenoid A to asperterpenoid A with 3-carboxyl and 11-hydroxymethyl groups. However, the oxidation order of C-19 and C-21 catalyzed by AstB is unclear. In order to reveal this oxidation order, probable pathways catalyzed by AstB were proposed, and the oxidation order of C-19 and C-21 was obtained by quantum chemistry calculations. The potential intermediates (three new asperterpenoids D–F, 1–3) were obtained through the chemical investigation on the extract of the transformant strain and chemical conversions, which were used as the standards to detect their existences in the extract of the transformant strain with HPLC-MS. Combined with the quantum chemistry calculation and the HPLC-MS analysis, the catalyzed order of AstB in asperterpenoid A biosynthesis was revealed. Furthermore, the mPTPB inhibition of obtained asperterpenoids was evaluated, and the results showed that 3-carboxyl and the oxidation station of C-21 would be the key factors for mPTPB inhibition of asperterpenoids.

The Machangqing porphyry Cu-Au deposit is located in the Sangjiang region, Jinshajiang-Ailaoshan metallogenic belt, southeastern Tibet. It has three main phases of felsic-mafic intrusions: barren granites, ore-forming porphyry intrusions, and mafic lamprophyres. U-Pb zircon dating shows that these intrusions were emplaced over a period of ~3 m.y., with lamprophyres at 36.50 ± 1.6 Ma (1σ), porphyry intrusion at 34.26 ± 0.22 Ma (1σ), and granite intruded at 34.00 ± 0.26 Ma (1σ). The in situ Rb-Sr analysis of phlogopite and amphibole, primary minerals in the lamprophyres, also gives a date of 36.5 ± 1.5 Ma (2σ), regarded as the emplacement age of the lamprophyre, earlier than the ore-forming porphyry intrusions. The magmatic phases have significantly different sulfur and chlorine contents. The SO3 contents of igneous apatite microphenocrysts from the mineralization-related porphyry intrusions are higher (0.24 ± 0.14 wt %, 1σ, n = 82) than those from the barren granites (0.08 ± 0.07 wt %, 1σ, n = 30). The chlorine contents in apatite grains from the porphyry intrusions (0.18 ± 0.16 wt %, 1σ) are also higher than those from granites (0.04 ± 0.02 wt % Cl, 1σ). The apatite in lamprophyres have higher sulfur (0.68 ± 0.19 wt %, 1σ, n = 40) and chlorine (0.48 ± 0.13 wt %, 1σ). The large difference of Cl and S in lamprophyres might suggest that elevated magmatic volatile contents derived from the mafic magma were important for ore formation in the Machangqing porphyry systems. The in situ Sr and O isotopes in apatite phenocrysts from the porphyry intrusions (87Sr/86Sr: 0.70593–0.70850; δ18O: 6.0–7.0) are similar to those in the lamprophyres (87Sr/86Sr: 0.70595–0.70964; δ18O: 5.4–6.9), consistent with similar origins for their volatile contents. These data may indicate that the deeper magma chamber was recharged by a relatively S-Cl-rich mafic magma similar to the lamprophyres, triggering the ore-forming magmatic event. This study also suggests that origin of apatite Sr and also volatile contents, combined with in situ Sr and O isotopes, could be useful for fingerprinting fertile intrusions associated with mineralization within drainage source areas or in outcrops.

Background and Purpose The human gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders. However, its efficacy in preventing non-alcoholic fatty liver disease (NAFLD) and the mechanism involved in its well-known metabolic actions are unknown. The present study explored the therapeutic effect and novel mechanism of A. muciniphila in intervening NAFLD. Experimental Approach The anti-NAFLD activity of A. muciniphila was evaluated in an obese mouse model induced by high-fat and cholesterol (HFC) diets using three different interventions. The gut microbiota composition, beneficial metabolic effects in the gut-liver axis were explored. The level and beneficial metabolic effects of L-aspartate in vitro and in vivo were further determined. Key Results Mice treated with A. muciniphila efficiently reversed NAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in a germ-free mouse model. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress- induced cell apoptosis in the gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above. Conclusion and Implications The anti-NAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut-liver interactions through regulating L-aspartate metabolism. A. muciniphila would be a potent agent for clinical intervention in NAFLD.

Legionella pneumophila, an environmental bacterium that parasitizes protozoa, is the causative pathogen of Legionnaires' disease. L. pneumophila adopts a distinct biphasic life cycle that allows it to adapt to environmental conditions for survival, replication, and transmission. This cycle consists of a non-virulent replicative phase (RP) and a virulent transmissive phase (TP). Timely and fine-tuned expression of growth and virulence factors in a life cycle-dependent manner is crucial. Herein, we report evidence that CsrA, a key regulator of the switch between the RP and the TP, is dually regulated in a ClpP-dependent manner during the biphasic life cycle of L. pneumophila. First, we show that the protein level of CsrA is temporal during the life cycle and is degraded by ClpP during the TP. The ectopic expression of CsrA in a ΔclpP mutant, but not in the wild type, inhibits both the initiation of the RP in vitro and the invasiveness to Acanthamoeba castellanii, indicating that the ClpP-mediated proteolytic pathway regulates the CsrA protein level. We further show that the temporally expressed IHFB is the transcriptional inhibitor of csrA and is degraded via a ClpP-dependent manner during the RP. During the RP, the level of CsrA is increased by promoting the degradation of IHFB and reducing the degradation of the accumulated CsrA via a ClpP-dependent manner. During the TP, the level of CsrA is decreased by inhibiting the degradation of IHFB and promoting the degradation of the accumulated CsrA via a ClpP-dependent manner as well. In conclusion, our results show that the growth-stage-specific expression level of CsrA is dually regulated by ClpP-dependent proteolysis at both the transcription and protein levels during the biphasic life cycle of L. pneumophila.

Legionella pneumophila, an environmental bacterium that parasitizes protozoa, is the causative pathogen of Legionnaires' disease. L. pneumophila adopts a distinct biphasic life cycle that allows it to adapt to environmental conditions for survival, replication, and transmission. This cycle consists of a non-virulent replicative phase (RP) and a virulent transmissive phase (TP). Timely and fine-tuned expression of growth and virulence factors in a life cycle-dependent manner is crucial. Herein, we report evidence that CsrA, a key regulator of the switch between the RP and the TP, is dually regulated in a ClpP-dependent manner during the biphasic life cycle of L. pneumophila. First, we show that the protein level of CsrA is temporal during the life cycle and is degraded by ClpP during the TP. The ectopic expression of CsrA in a ΔclpP mutant, but not in the wild type, inhibits both the initiation of the RP in vitro and the invasiveness to Acanthamoeba castellanii, indicating that the ClpP-mediated proteolytic pathway regulates the CsrA protein level. We further show that the temporally expressed IHFB is the transcriptional inhibitor of csrA and is degraded via a ClpP-dependent manner during the RP. During the RP, the level of CsrA is increased by promoting the degradation of IHFB and reducing the degradation of the accumulated CsrA via a ClpP-dependent manner. During the TP, the level of CsrA is decreased by inhibiting the degradation of IHFB and promoting the degradation of the accumulated CsrA via a ClpP-dependent manner as well. In conclusion, our results show that the growth-stage-specific expression level of CsrA is dually regulated by ClpP-dependent proteolysis at both the transcription and protein levels during the biphasic life cycle of L. pneumophila.

Virulent protein toxins secreted by the bacterial pathogens can cause cytotoxicity by various molecular mechanisms to combat host cell defense. On the other hand, these proteins can also be used as probes to investigate the defense pathway of host innate immunity. Ralstonia solanacearum, one of the most virulent bacterial phytopathogens, translocates more than 70 effector proteins via type III secretion system during infection. Here, we characterized the cytotoxicity of effector RipI in budding yeast Saccharomyce scerevisiae, an alternative host model. We found that over-expression of RipI resulted in severe growth defect and arginine (R) 117 within the predicted integrase motif was required for inhibition of yeast growth. The phenotype of death manifested the hallmarks of apoptosis. Our data also revealed that RipI-induced apoptosis was independent of Yca1 and mitochondria-mediated apoptotic pathways because Δyca1 and Δaif1 were both sensitive to RipI as compared with the wild type. We further demonstrated that RipI was localized in the yeast nucleus and the N-terminal 1-174aa was required for the localization. High-throughput RNA sequencing analysis showed that upon RipI over-expression, 101 unigenes of yeast ribosome presented lower expression level, and 42 GO classes related to the nucleus or recombination were enriched with differential expression levels. Taken together, our data showed that a nuclear-targeting effector RipI triggers yeast apoptosis, potentially dependent on its integrase function. Our results also provided an alternative strategy to dissect the signaling pathway of cytotoxicity induced by the protein toxins.

Two new isomeric modified tripeptides, aspergillamides C and D (compounds 1 and 2), together with fifteen known compounds (compounds 3-17), were obtained from the marine sponge-derived fungus Aspergillus terreus SCSIO 41008. The structures of the new compounds, including absolute configurations, were determined by extensive analyses of spectroscopic data (NMR, MS, UV, and IR) and comparisons between the calculated and experimental electronic circular dichroism (ECD) spectra. Butyrolactone I (compound 11) exhibited strong inhibitory effects against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with the IC50 being 5.11 ± 0.53 μmol·L-1, and acted as a noncompetitive inhibitor based on kinetic analysis.

The coastal zone continuously changes due to natural processes and human activities. In order to understand and predict these morphological changes, an accurate description of sediment transport, caused by waves and currents (tidal or wave-induced), is important. This paper presents a review of the state-of-the-art knowledge in this field, including sediment incipient motion, bed forms, bed roughness, bed-load transport, suspended-load transport, equilibrium sediment concentration, and sheet flow. Some possible research fields and topics for future study also are proposed.

Rivers have many service functions, and play an important role in people's living and agricultural production. During the last decades, intensive human activities have been threatening river ecosystem. For shipping, hydraulic engineering facilities (e.g. spur dikes) have been built along river bank to increase water depth. However, natural habitat conditions (i.e. substrate, flow regime, water physico-chemical properties) are accordingly altered. Therefore, it is necessary to select representative organisms as indicators to assess the aquatic ecological status of different habitat conditions, furthermore, management strategies are to be put forward. Macroinvertebrates are often considered as good indicators of long-term changes in environments due to their confinement to the bottom, long life cycles and limited abilities of movement. In this study, field investigations of macroinvertebrates in the West River were conducted in November 2009 (at low water level) and May 2010 (at high water level). Altogether 70 taxa of macroinvertebrates belonging to 30 families and 59 genera were identified. Among them were 16 annelids, 21 mollusks, 32 arthropods and 1 miscellaneous animal. The average density and biomass of total macroinvertebrates were 140 ind m −2 and 0.23 g dry weight m −2 , respectively. Canonical Correspondence Analysis (CCA) revealed that major factors structuring macroinvertebrate assemblages were flow velocity ( U ), water depth ( Z ), conductivity (Cond), total nitrogen (TN) and substrates (clay, silt, cobbles and bedrock). Density and diversity of macroinvertebrates peaked in the cobbles, while biomass reached the maximum in the bedrock. It is indicated that stable and heterogeneous habitats were beneficial to development of benthic assemblages. To conserve these habitats, type and construction position of spur dikes should receive enough attentions. Thus, it is suggested that as few spur dikes as possible can be constructed in the riverbed covered with cobbles and bedrocks. Otherwise, the angle between spur dike and river bank need be analyzed to generate the appropriate flow regime which can prevent the stable substrates from being buried by sands. Some advice about length and separation distance of spur dikes is also presented.

In order to study the mechanism of flow-sediment movement, it is essential to obtain measured data of water hydrodynamic and sediment concentration process with high spatial and temporal resolution in the bottom boundary layer (BBL). Field observations were carried out in the northwest Caofeidian sea area in the Bohai Bay. Near 2 m isobath (under the lowest tidal level), a tripod system was installed with AWAC (Acoustic Wave And Current), ADCP (Acoustic Doppler Current Profilers), OBS-3A (Optical Backscatter Point Sensor), ADV (Acoustic Doppler Velocimeters), etc. The accurate measurement of the bottom boundary layer during a single tidal period was carried out, together with a long-term sediment concentration measurement under different hydrological conditions. All the measured data were used to analyze the characteristics of wave-current-sediment movement and the BBL. Analysis was performed on flow structure, shear stress, roughness, eddy viscosity and other parameters of the BBL. Two major findings were made. Firstly, from the measured data, the three-layer distribution model of the velocity profiles and eddy viscosities in the wave-current BBL are proposed in the observed sea area; secondly, the sediment movement is related closely to wind-waves in the muddy coast area where sediment is clayey silt: 1) The observed suspended sediment concentration under light wind conditions is very low, with the peak value generally smaller than 0.1 kg/m3 and the average value being 0.03 kg/m3; 2) The sediment concentration increases continuously under the gales over 6–7 in Beaufort scale, under a sustained wind action. The measured peak sediment concentration at 0.4 m above the seabed is 0.15–0.32 kg/m3, and the average sediment concentration during wind-wave action is 0.08–0.18 kg/m3, which is about 3–6 times the value under light wind conditions. The critical wave height signaling remarkable changes of sediment concentration is 0.5 m. The results show that the suspended load sediment concentration is mainly influenced by wave-induced sediment suspension.

In order to solve NiuDong101 Well reservoir ultra high temperature (205 °C ) fluid fracturing low efficiency, quick acid rock reaction which usually adopt the 160°C fracturing fluid system. At the same time to meet the deep acid fracturing technology and greatly improve the output, so as to achieve the production increasing reserves of important target. So it is necessary to develop a novel 200°C fluid system to achieve high-efficient stimulation. Therefore, this paper invented a new high temperature resistant ternary anionic thickener, and launched some fracturing fluid performance evaluation. This fluid system achieved 176mpa.s under the condition of 200°Cand 170s-1of RS600 which can perform good temperature resisting & shearing resistance performance, breakthrough the limit of 200°Cof fracturing fluid temperature resistance. Field application to achieve a major breakthrough, it has important strategic significance for exploration promotion of bohai bay basin.

The development of resources has achieved revolution from unconventional resources to conventional resources in North America. China's tight oil and gas reservoirs are widely distributed and the exploration potential is tremendous. The abundant unconventional natural gas resources, if exploited reasonably and efficiently, will provide stable energy supply for the sustainable development of Chinese economy. In this paper, a few key techniques including drilling and hydraulic fracturing for the development of unconventional oil and gas resources were introduced. The factors of unconventional oil and gas were put forward,the costs of drilling and well completion and environmental concerns for the development of tight oil and gas in China included ground water contamination, risks to air quality, migration of gases were also introduced which has raised combined with the analysis of future prospects and future technology development. We also offer some technology which has the merits of low cost, efficient for the development of unconventional tight reservoir in horizontal wells. Good conditions have been found in Sichuan, Tarim and Ordos basins for both development and exploitation, finally we can come to a conclusion that the tight oil and gas should be realistic replacement resources of conventional oil and gas.

Frequency and mode are character parameters of structure, and mode is also self-contained coordinate basis vector of displacement, so mode can be used for concept design and mechanical design. Through depth-width ratio from one to seven, results indicate the whole deformation of structure varies from shear mode to bend mode gradually; except for vertical mode, general mode is not one deformation, it is coupled by several deformations and one deformation ratio is dominant. During three of depth-width ratio, structure deforms in shear mode, so masonry structure should be in that range. In order to exerting reinforced concrete and steel material property and energy consumption capacity, the depth-width ratio should be from three to seven. For depth-width ratio between five and seven, the first eight modes is the same, manifesting mode has convergence property.

Riverbed structures were developed in many very coarse gravel-bed rivers as a result of fluvial morphology. And the distribution of them was obviously relevant with environment conditions. This paper carried out field investigations in natural rivers, to study the riverbed structures size, distribution in the basin, as well as their connections with local environmental conditions. The results indicated that: The structures can enhance resistance to water erosion and protect riverbed. Given the conditions of little bedload, the structure intensity is in direct ratio to the unit-width stream power which consumed by the structures when rivers are in dynamic equilibrium. If the structures are not able to dissipate the whole power, the river status turns to disequilibrium and the riverbed will be eroded by excess energy. The fluvial morphology of coarse-grained riverbed is controlled by this process.

In China,more and more low permeability reservoirs have become the mainly oil production potential part for the soaring consumer market. Hydraulic fracturing treatment has always been playing an important role in these low permeability reservoirs.however,some inappropricate fracturing designs and treatments may decrease the productions as a result of high damage within both formations and artifical fractures.In order to minimize reduce formation and fracture damage, we take the wells in Erlian Basin as an example to explain the low-damage hydraulic fracturing technique which had been used in many of oil fields .Through eight years step by step study and field application, a comprehensive industrialize design technology was put forward. By the application of this technique, the low-damage degree is highlighted compared to the past.As a result the performance of post-fracturing wells have remarkably improved.

The homogeneous solutions of the governing differential equations for shear lag are used as the displacement patterns of the finite segment are presented. A finite segment model with consideration of initial curvature, bending, torsion and shear lag is established. In addition, the tests of the two-span continuous curved box girder and numerical calculations of the model tests by finite segment method and finite element method are made. The results of the model tests and numerical calculation are consistent with each other. An actual example was given to investigate the shear lag effect of a continuous curved box girder under load. The research results show that the initial curvature has an obvious influence on the shear lag effect of a continuous curved box girder.

This study investigates the influence of ground water injection on the initial movement of non-cohesive sediment particles on a riverbank slope analytically and experimentally. By including the hydraulic gradient in the force analysis, the critical condition was derived to account for the effect of seepage flow, showing that the seepage hydraulic gradient and the riverbank slope are governing parameters in modifying the incipient motion of sediments on a riverbank slope. Experimental investigations were performed in an open-channel flume for various riverbank slopes and hydraulic gradients of injection, showing that the critical shear stress increases with decreasing riverbank slopes and vise-versa, while injection reduces the critical value. All experimental data agree well with the theoretical derived expression of the critical condition in the case of injection.

Monitoring the actual state of transformer is imperative for measuring the errors of transformer with its actual burden load. The simplified three phases testing method is the practical and effective in monitoring the transformer state. And a programmable three-phase power supply is its core. The three-phase programmable power supply using DDS synthesizer can change the phase angle through changing triggering time of frequency update and adjusts amplitude through multiplier. It can generate three-phase signal voltage whose amplitude and phase angle can be adjusted by program. So it is suitable for the instrument for measuring the errors of transformer with its actual burden load. By using the instrument an environment of actual burden load is simulated completely. So the measuring of transformers with actual burden load is made precisely. The measuring principle and hardware and software design of the instrument are discussed in the paper.

This paper presents a three-dimensional (3D) mathematical model for suspended load transport in turbulent flows. Based on the stochastic theory of turbulent flow proposed by Dou, numerical schemes of Reynolds stresses for anisotropic turbulent flows are obtained. Instead of a logarithmic law, a specific wall function is used to describe the velocity profile close to wall boundaries. The equations for two-dimensional suspended load motion and sorting of bed material have been improved for a 3D case. Numerical results are in good agreement with the measured data of the Gezhouba Project. The present method has been employed to simulate sediment erosion and deposition in the vicinity of the Three Gorges Dam. The size distribution of the deposits and bed material, and flow and sediment concentration at different times and elevations, are predicted. The results agree well with the observations in physical experiments. Thus, a new method is established for 3D simulation of sediment motion in the vicinity of dams.

Petroleum and nature gas not only are important resources, but also are important strategic materials of our country. All methods the enhancing the producing degree of petroleum and natural gas reservoir, increasing single well production and extending the stimulation period of validity are important stratagem for petroleum and natural gas exploitation. Fracturing and acidizing are the main methods for stimulation as well as one of representative examples of rheology theory application in engineering. Based on analysis of low permeability reservoir characteristics, the fracturing and acidizing stimulation principles and main controlling factors were discussed. And the mechanical characteristics, chemical reaction and rheological behavior in the stimulation process were reviewed. Furthermore research trends afterwards including the material and fluid rheology in oil and natural gas production process, the deep rock fracture initiation and extension rheology, and the fracturing and acidizing application rheology were also proposed in this paper.

A simple and reproducible method has been developed to transform Legionella pneumophila by electroporation. Effects of different conditions, including electric field strength, pulse length, DNA quality and cell density, were evaluated. Using our method, an efficiency of up to 6 x 10(7) transformants/microg DNA was obtained. This optimized transformation procedure should efficiently facilitate gene manipulations in L. pneumophila, such as plasmid transfer, transposon mutagenesis, library transformation for complementation cloning, etc.

Mode is the inherent property of structure, and any action response can be decomposed by mode matrix. Through the mode expansion, each mode direction parameter can be clarified, and the designer can elevate the good response and cut down the bad one. So the designer has capacity that assesses the whole structure property by the mode analysis, and guides the concept design and mechanical design.

Listeria monocytogenes can cause listeriosis in humans through consumption of contaminated food. L. monocytogenes can adapt and grow in a vast array of physiochemical stresses in the food production environment. In this study, we performed a proteomics strategy in order to investigate how L. monocytogenes survives with a simultaneous exposure to low pH, high salinity and low temperature. The results showed that the adaptation processes mainly affected the biochemical pathways related to protein synthesis, oxidative stress, cell wall and nucleotide metabolism. Interestingly, enzymes involved in the carbohydrate metabolism of energy, such as glycolysis and pentose phosphate pathway, were derepressed due to the down-regulation of CodY, a global transcriptional repressor. The down-regulation of CodY, together with the up-regulation of carbohydrate metabolism enzymes, likely leads to the accumulation of pyruvate and further to the activation of fatty acid synthesis pathway. Proteomics profiling offered a better understanding of the physiological responses of this pathogen to adapt to harsh environment and would hopefully contribute to improving the food-processing and storage methods.

An optical system consisted of lens array with variable focus width has been proposed for providing uniform irradiation on targets in inertial confinement fusion. This system was composed of two lenses arrays and the aspheric lens. Based on the adaxial matrix optics and the generalized diffraction integral theory, the principle of controllable focus profile was analyzed and the optimum design of the system parameters were presented, respectively. The simulated results showed that two-dimensional uniform focusing of laser beams with controllable width in the range of several hundred microns to several millimeters can be achieved by choosing appropriate system parameters. The system converted a circular laser beam into a flat-top square focused spot, presenting the transformation of beamshape and the uniform distribution of the spatial intensity at the same time. Appropriate concentricity deviation of LA was made in the design of LA focus system, so that the diffraction patterns of different beamlets did not completely overlap and the large-scale intensity fluctuation reduced effectively, and a well-irradiated laser spot and great energy efficiency can be obtained in this scheme.

Legionella pneumophila is the intracellular bacterial pathogen that causes severe Legionnaires' disease and flu-like Pontiac fever. To accomplish successful aggression against hosts, L. pneumophila secrets more than 150 kinds of substrate effector proteins into host cells via its Type IVB secretion system. With the multiple functions of effectors, L. pneumophila evades effectively the defense systems of hosts, converts or adjusts intracellular vesicular transport of hosts, modifies or disguises its Legionella containing vacuole (LCV), modulates the cell cycle program and inhibits the apoptosis of host cells, and finally gains the comfortable intracellular replicative niche. Effectors can also help L. pneumophila escape from hosts cells after completing the proliferation.. L. pneumophila has became the distinct model for pathogen-host interaction research, and its secretion systems as well as the substrate effectors are attracting more and more attentions. Researching on T4BSS and effectors could not only help investigate the pathogenesis of intracellular bacterial pathogens, but also promote the comprehension about innate immune responses of hosts. This article reviews the progresses of L. pneumophila T4BSS and effectors, trying to demonstrate to the readers the cunning survival strategy and the delicate virulent machine of L. pneumophila.

Iron homeostasis is essential to almost all organisms. In this study, we identified the putative homolog of the iron-storage protein-encoding gene, dpsL, in the intracellular pathogen Legionella pneumophila and demonstrated its expression under iron-limited conditions and its responses to multiple stresses. Quantitative real-time PCR analysis indicated that the expression of dpsL was enhanced under iron limitation regardless of the growth phase. Compared with the wild-type cells, the cells devoid of dpsL were heat and H(2)O(2)-sensitive. In contrast to the dps mutants of other bacteria, the growth of the dpsL mutant in an iron-deprived medium was delayed but finally reached the same cell density as wild-type cells during the stationary phase of growth. The finding that the dpsL mutant is salt resistant suggested the involvement of DpsL in virulence.

Breakdown of rock-fill spur-dykes occurs very often in natural streams downstream of hydropower station due to rapid flows. In this paper the laboratory investigations in an open-channel flume have been presented, showing how the stability of the dykes is influenced by the flow downstream of hydropower station. The main factors, which results in the breakdown of the spur-dykes, are analyzed and the countermeasures against the collapse are summarized. Furthermore, the layout of geotextile soft mattress as a countermeasure against the indirect damage is suggested based on the measurements of turbulent flows around the spur-dyke. Also, modification in cross-section of spur-dykes is proposed as a countermeasure against the direct damage.

The present study aimed at evaluating the clinical importance of Mcm7 and Cdc6 expression in oral squamous cell carcinoma (OSCC) and precancerous lesions.RT-PCR and immunohistochemistry analysis were performed on 47 frozen samples and 98 paraffin-embedded samples to evaluate the mRNA and protein expressions of Mcm7 and Cdc6.RT-PCR and immunohistochemistry indicated positive expressions of Mcm7 mRNA and protein in normal oral mucosa, precancerous lesions and OSCC. Significant differences were found between all the groups. Cdc6 mRNA and protein had low expressions in normal oral mucosa but were highly expressed in precancerous lesions and OSCC. Mcm7 and Cdc6 expressions in the lymph node metastasis cases were significantly higher than those of the nonmetastatic carcinomas.High expressions of Mcm7 and Cdc6 are correlated with the development and metastasis of OSCC and may become a molecular marker for the early diagnosis and prognosis prediction for OSCC.

Rock-fill spur-dykes are often destroyed due to rapid flows in mountainous rivers. On the basis of laboratory work in a flume, this paper describes the instability of rock-fill spur-dykes qualitatively, analyzing the classification of direct damage and indirect damage, respectively, and some main influencing factors as well, also summarizes countermeasures against the instability. Furthermore, the analyses of turbulent flow around the spur-dyke and its role on the riprap protection are performed, accordingly the layout of geotextile soft mattress as a countermeasure is determined. Observations on the entrainment of the top stones show that dune-shaped rock-fill spur-dyke improves the stability of rock, and therefore modification in cross-section of spur-dykes is proposed as a countermeasure against the direct damage.

This paper introduced an optical method for measuring the thickness of solid thin films. This method is of high measuring speed, noncontact and online work. An experimental system has been constructed for on-line measurement of the thickness of thin film. The experimental results show that the measuring error is lower than 10% in the range of 10~100μm , which fit the production need.

Correlation spectroscopy can be used to describe the linear correlationship between the absorbance and concentration data in the whole spectra range and clearly figure out the characteristic peak position of the sample under test. Meantime, this chart plays an extremely important role in offering the precise information for choosing the optimal wavelength set during the calibration process. Multiple scatter correct (MSC) spectroscopy is a kind of multiple variable scatter correction technique, and can effectively remove the base shift and tilt phenomenon caused by MSC. As a result, the ratio of signal to noise is improved greatly. Based on this feature, the new idea of the MSC technique was introduced into the preceding data treatment for the creation of correlation chart, and through careful experiment this idea was proved to be correct and effective.

In the present paper the saponin in Chinese ginseng was analysed quantitatively by using near infrared spectroscopy. The spectral characteristics of the primary ingredients in Chinese ginseng were obtained by applying second derivative, MSC (Multiple Scatter Correction), and correlation chart to the original absorbance spectra of ginseng. Meantime, in combination with the PLS algorithm the calibration process was performed for the quantitative analysis of saponin in Chinese ginseng. The result obtained shows a fine precision of the method, with RMSEC of 0.154% and correlation coefficient of 0.9828.

Multiple scattering correction(MSC) algorithm can be used effectively to remove the effect of scattering due to the physical factors such as the density and humidity of sample granule, and as a result the ratio of signal to noise is improved greatly. Meantime correlation spectrum plays a important role in the choice of optimum wavelength set because it describes the linear correlationship between the absorbance and concentration of the sample's ingredient under analysis. However, the correlation spectrum obtained by unitary linear regression(ULR) at single wavelength channel can be easily affected by the scattering so as to cover up the characteristic linear information of the sample. In order to solve the problem in the present paper MSC was applied to obtain useful signal and suppress noise of correlation spectrum. Through the careful calibration experiment of ginseng sample this idea has proved to be correct, and satisfactory result was obtained.

In the present paper the analysis of the total content of sugar in Chinese ginseng was carried out by using near infrared spectroscopy, and in combination with the PLS algorithm the calibration analysis was performed at the same time. The result shows that the precision obtained through common chemical methods is almost the same as the one through NIR spectroscopy. The SEC (standard error of calibration) is 1.9% and the correlation coefficient is 0.951 7, which proves that this technique is well suitable for rapid quantitative determination of the total content of sugar in Chinese ginseng, and is simple, cheap, and without any chemical pollution, and can present real time result.

ColE1-type plasmids are commonly used in bacterial genetics research, and replication of these plasmids is regulated by interaction of RNA I and RNA II. Although these plasmids are narrow-host-range, they can be maintained in Legionella pneumophila under antibiotic selection, with low-copy number and instability. Here, we have described the isolation of two novel spontaneous mutants of pBC(gfp)Pmip, pBG307 and pBG309, which are able to mark the L. pneumophila with strong green fluorescence when exposed to visible light. One of the mutants, pBG307, has a single CG-->TA mutation in RNA II promoter located 2-bases upstream the - 10 region. Another one, pBG309, has the same mutation, as well as an additional CG-->AT mutation in the 76th nucleotide of RNA I, or in the 6th nucleotide of RNA II. A plasmid with the single mutation in RNA I, pBG308, was also constructed. Characterization of these plasmids carrying the enhanced green fluorescent protein (gfpmut2) gene revealed that the green fluorescence intensities of these plasmids were 2- to 30-fold higher than that of the wild type and both of the mutations contribute to increase the plasmid copy number and/or plasmid stability. The mutation located in RNA II promoter played a more dominant role in elevating the copy number, compared to the mutation in RNA I. We also tested the mutant plasmids for replication in Escherichia coli, and found that their copy number and stability were dramatically decreased, except pBG307. Our data suggest that these plasmids might be useful and convenient in genetic studies in L. pneumophila.

Near infrared (NIR) reflectance spectroscopy was used to develop a fast determination method for total ginsenosides in Ginseng (Panax Ginseng) powder. The spectra were analyzed with multiplicative signal correction (MSC) correlation method. The best correlative spectra region with the total ginsenosides content was 1660 nm~1880 nm and 2230nm~2380 nm. The NIR calibration models of ginsenosides were built with multiple linear regression (MLR), principle component regression (PCR) and partial least squares (PLS) regression respectively. The results showed that the calibration model built with PLS combined with MSC and the optimal spectrum region was the best one. The correlation coefficient and the root mean square error of correction validation (RMSEC) of the best calibration model were 0.98 and 0.15% respectively. The optimal spectrum region for calibration was 1204nm~2014nm. The result suggested that using NIR to rapidly determinate the total ginsenosides content in ginseng powder were feasible.

In the present paper the caffeine in the tea polyphenol was analysed spectrally and quantitatively by using near infrared spectroscopy. From the original absorbance of caffeine in the tea polyphenol an obvious and strong peak can be viewed. By using second derivative, MSC (multiple scatter correction) and correlation analysis the spectral characteristics of caffeine in the near infrared region can be seen very clearly, thus the robust calibration model can be set up easily. The result obtained shows that through this technique the absorptive characteristic of those primary fundamentals of caffeine can be looked through easily, meanwhile, calibration test was performed to quantitatively measure the weight percent of caffeine in the tea polyphenol, and fine precision of the result was obtained in a comparatively very large range of concentration. The SEC(standard error of calibration) is 0.49%, and the correlation coefficient r is 0.993. The result shows that NIR is feasible and superior in analyzing the content of caffeine in tea polyphenol.

During the manufacture and debugging of the NIR instruments it is compulsory to make final calibration analysis to verify whether the instruments operate correctly. However, the conventional method of NIR calibration needs to make calibration analysis for the instruments with all the samples at hand. In fact in order to cover the samples that will be encountered in the future the amount of the samples set and the labor that the personnel need to offer are enormous. In this paper a new algorithm is presented which can be used to effectively eliminate the similar samples in the original sample set. By using this algorithm we have chosen 94 optimal samples in the original 178 sample set successfully. After performing calibration experiment we found that the sample set chosen by this algorithm are equally representative to the original sample set and obtained almost the same precision compared to the original sample set when the two sample sets were individually calibrated. This algorithm brings great relief to the labor of the workers, presents the possibility of performing more experiments and greatly improves the efficiency of performing calibration experiment. As a result, the amount of calibration sets and the labor of the personnel are reduced remarkably.

For spectrometers which don't operate in consistently scanning mode such as fixed-filter spectrometer, diode arrays spectrometer and so on, how to find an optimal wavelengths combination rapidly and accurately has always been a key problem in NIR so far. The conventional methods to choose the optimal wavelengths for calibration are Forward Stepwise multiple linear Regression (FSR) and Backward Stepwise Regression (BSR), which choose the optimal wavelengths based on the t test result of all the calibration wavelengths. However, maybe the wavelength eliminated is very useful in application and the wavelength chosen may not be so useful as expected, as a result it is compulsory to make more tests to verify the truly applicable wavelength combination for calibration. In this paper the combination of the combination-making algorithm in combinatorics and computer languages which operate facing matrix is used to choose the optimal combination of wavelengths for calibration automatically and efficiently by computer. The most robust calibration equation can be obtained by making analysis of calibration regression that operates to find the minimum root mean standard error of calibration.

Structures of three Stemona alkaloids from a Chinese medical plant are described. Both stemotinine 1 and isostemotinine 2 isolated from the roots of Stemona tuberosa Lour. (Stemonaceae) are shown to be pentacyclic compounds containing two α-methyl-γ-lactone rings; the structure fo stemonidine isolated in 19481 has also been determined as 3. Structure elucidations are based on detailed 1H- and 13C NMR studies. A preliminary account is given on a line-broadening effect of 1H NMR signals which are in spatial proximity with incipient N+D bonds.

A high-performance liquid chromatography method is described for the separation of the α- and β-isomers of aspartyl-containing peptides such as N-benzyloxycarbonyl methyl aspartate, protected sweet dipeptide and delta sleep inducing peptide (DSIP, a nonapeptide). The α- and β-isomers were separated on a column containing octadecyl silica bonded-phase packing under reversed-phase conditions using methanol-water as the mobile phase containing a small amount of acetic acid. The resolution achieved meets the requirements of qualitative and quantitative analysis. This method is also suited for the determination of intermediates in the aspartyl peptide synthesis.