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This paper presents a microscale modeling approach for investigation of bubble dynamics in the aluminum smelting process. The motion of a single bubble has been studied through a computational fluid dynamics (CFD) model facilitated with the volume-of-fluid (VOF) method to capture the bubble shapes. Using a two-dimensional geometry of part of a real cell as the testing bed, the motion of different sized bubbles has been simulated in an air–water system and a CO2–cryolite system. Comparisons between the two systems are conducted through the three periods of bubble motion: bubble sliding under the anode, bubble releasing at the anode edge, and bubble rising in the side channel. It was found that both systems show similar trends in bubble dynamics, such as an increase in the bubble sliding velocity as the bubble size increases and the appearance of a thick head at large bubble sizes. Quantitatively, there are differences between the two systems, evidenced in terms of the detailed bubble dynamics at each perio...

Surface wettability of thin films is significant for their functional properties. Poly(l-lactic acid) (PLLA) is proposed as film matrix for building porous topological surfaces. By controlling the dope composition and ambient conditions, the films with ordered pores at micrometer scale are obtained. The results demonstrate that the hydrophilic or hydrophobic surface can be realized by building the porous topological surfaces. Increasing polymer concentration can lead to decreased pore size. The transition behavior of surface pores from discrete bowl-like to interconnected honeycomb-like structure with the increasing humidity is observed. The contact angle of top surface of film is higher than that of bottom surface, which verified the different roughness performance. The morphology and scale of topological structure are markedly related with the template effect of water droplets. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44572.

Molecular imprinting process was proposed for the sulfur removal from fuels. The novel network-structured molecularly imprinted polymers (MIPs) were fabricated by arranging 4-vinyl pyridine functional monomers around dibenzothiophene template compounds, and fixing them with ethylene glycol dimethacrylate as cross-linking agent. The effects of dispersed phase, washing after treatment, content of template molecule, and cross-linking agent on the recognition ability of MIPs have been investigated. The practical performance is obtained by the FT-IR, morphology, and thermal analysis as well as the recognition ability for dibenzothiophene under various feed sulfur concentrations and recognition time. The recognition ability of MIPs under 1000 mg/L feed sulfur concentration was 4.53 mg S/g. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44552.

This study investigated the effects of adding Cu(II) at two exposure levels (50 and 500mgkg-1, i.e., Cu50 and Cu500 treatments, respectively) on the activity of ammonia-oxidizing microorganisms during dairy cattle manure composting. The results showed that the pH, NH4+-N, NO3--N, and potential ammonia oxidation values were inhibited significantly by the addition of Cu(II). Furthermore, the abundances of the ammonia-oxidizing archaea (AOA) amoA gene and ammonia-oxidizing bacteria (AOB) amoA gene were determined by quantitative PCR, and their compositions were evaluated by denaturing gradient gel electrophoresis (DGGE). AOA was the dominant ammonia oxidizing microorganism, of which the abundance was much higher than AOB during composting. Cu50 and Cu500 had significant inhibitory effects on the abundance of the amoA gene. The DGGE profile and statistical analysis showed that Cu(II) changed the AOA and AOB community structure and diversity, where Nitrosomonas and Crenarchaeota dominated throughout the composting process.

There are about half reserves remaining underground after polymer flooding, which are huge reserves for further tapping. So how to enhance oil recovery greatly after polymer flooding has been a major technical challenge in china or abroad. According to the data of 20 pressure coring wells after polymer flooding, the places where remaining oil locate are precisely described in this paper and on the basis of laboratory research and numerical simulation and geological study, a new method has been developed that combines well pattern restructuring for changing fluid flowing direction and high concentration polymer flooding so as to tap remaining oil which scatters highly and enriches relatively in distributary streamline after polymer flooding. Field test which used this new method has been carried out at B2D block in Daqing oilfield after polymer flooding. In order to get optimum mobility control, a reasonable formula of high concentration polymer system is optimized and the molecular weight and concentration of polymer are respectively 25 million and 2500 mg/L. Some good responses have been obtained in this field test. The injection pressure has increased by 4.3 MPa and the fluid absorption thickness ratio has increased by 26.3% and water cut drop maximum of central well has reached 16% and its incremental oil recovery is 5%. Based on this field test, it can be concluded that whether a field test after polymer flooding can get a good development effect, well pattern infilling is a premise and remaining oil distribution is a major influential factor and reasonable mobility ratio and injection-production ratio are important safeguards. High concentration polymer flooding with well infilling to change fluid flowing direction is a very effective technology to enhance oil recovery after polymer flooding. This technology has gain very good technological and economic effect, its final incremental oil recovery is 6.77% predicted by numerical simulation and its internal rate of return is 21.9%. This technology has wide application prospects and can be widely applied in blocks of Daqing oilfield after polymer flooding.

Aims: To investigate the antimicrobial efficacy of an alkaloid, harmaline alone and in combination with chlorhexidine digluconate (CHG) against clinical isolates of Staphylococcus aureus (S. aureus) grown in planktonic and biofilm cultures. Methods: Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined for each micro-organism grown in suspension and in biofilm using microbroth dilution method. Chequerboard assays were used to determine synergistic, indifferent or antagonistic interactions between harmaline and CHG, and the some of results were verified by confocal laser scanning microscopy. Results: Harmaline and CHG showed effective antimicrobial activity against suspensions and biofilm cultures of S. aureus, respectively. As determined by fractional inhibitory concentration index (FICI), synergistic antimicrobial effects between harmaline and CHG were observed in nine and 11 of the 13 S. aureus strains when in suspension and in biofilm, respectively. FICI values were from 0·375 to 1·25 when in suspension and from 0·25 to 1·25 when in biofilm. Conclusions: Synergistic activity of harmaline and CHG against clinical isolates of S. aureus (in suspension and in biofilm) was observed in vitro. Significance and Impact of the Study: This study might provide alternative methods to overcome the problem of drug-resistance of S. aureus both in suspension and in biofilm.

A fully hydraulic variable valve system based on spark-ignition engine BJ486EQ is introduced in this article, which can provide fully variable valve lifts, valve timing, and valve opening duration. A simulation model of fully hydraulic variable valve system is established, which is verified through experimental intake valve lift and hydraulic pressure. It is found that pressure fluctuation in hydraulic system of fully hydraulic variable valve system becomes greater with the increase in engine speed, which even leads to “lift distortion.” The cam profile of fully hydraulic variable valve system and the structure of the throttling valve which is used to reduce valve seating speed are optimized by simulation. The lift distortion and rebound do not occur in the optimized fully hydraulic variable valve system, which is indicated by the results of simulation and experiments when the engine speed is 5000 r/min, and valve seating characteristics become stable and soft.

Summary. This study aimed to identify the viral factors responsible for poor sensitivity to lamivudine (LAM). We analyzed 49 LAM-treated chronic hepatitis B patients infected with hepatitis B virus (HBV) genotype C. Serum HBV DNA reached a level below the detection limit of the sensitive PCR assay in 31 (63.3%) within the first 24 weeks of LAM therapy (good responder group). Of the patients who did not achieve undetectable levels of HBV DNA within 24 weeks (poor responder group), 15 (83.3%) experienced virological breakthrough, whilst only four patients in the good responder group (12.9%) experienced virological breakthrough. Multivariate analysis revealed that failure to achieve a reduction in viral load to undetectable levels within 24 weeks was independently associated with the occurrence of virological breakthrough. Sequence analysis of the HBV genome revealed that point mutations in the precore region (G1896A) and enhancer I (A1287G/C) were observed more frequently in the good responder group than in the poor responder group (P = 0.002 and 0.019 respectively), and the number of substitutions in the reverse transcriptase domain of the polymerase was significantly higher in the good responders than in the poor responders (P = 0.026). In conclusion, determining the sequence of preexisting HBV, especially for enhancer I, the precore region, and the RT domain of the polymerase region, may be useful in predicting sensitivity to LAM therapy.

People attach more and more importance to bionic compound eye due to its advantages such as small volume, large field of view and sensitivity to high-speed moving objects. Small field of view and large volume are the disadvantages of traditional image sensor and in order to avoid these defects, this paper intends to build a set of compound eye system based on insect compound eye structure and visual processing mechanism. In the center of this system is the primary sensor which has high resolution ratio. The primary sensor is surrounded by the other six sensors which have low resolution ratio. Based on this system, this paper will study the target image fusion and extraction method by using plane compound eye structure. This paper designs a control module which can combine the distinguishing features of high resolution image with local features of low resolution image so as to conduct target detection, recognition and location. Compared with traditional ways, the way of high resolution in the center and low resolution around makes this system own the advantages of high resolution and large field of view and enables the system to detect the object quickly and recognize the object accurately.

In order to solve the issue between fast autofocusing speed and high volume data processing, we propose a bioinspired sampling method based on a retina-like structure. We develop retina-like models and analyze the division of sampling structure. The optimal retina-like sample is obtained by analyzing two key parameters (sectors and radius of blind area) of the retina-like structure through experiments. Under the typical autofocus functions, including Vollath–4, Laplacian, Tenengrad, spatial frequency, and sum-modified-Laplacian (SML), we carry out comparative experiments of computation time based on the retina-like sample and a traditional uniform sample. The results show that the retina-like sample is suitable for those autofocus functions. Based on the autofocus function of SML, the average time of uniform sample decreases from 3.5 to 2.1 s for the retina-like sample.

A ranging method based on the differential time domain method (DTDM) is proposed in order to improve ranging accuracy and the range of active measurement based on peak discriminator (PD). We develop mathematical models and deduce that zero-crossing sensitivity is an important factor, which affects the ranging error of DTDM. Additionally, zero-crossing sensitivity is determined by delayed time. We carried out relative experiments and obtained the smallest ranging error when delayed time is receiving pulse width. We also compare ranging, three-dimensional (3D) point clouds and depth images based on two methods under same testing conditions. The results show that DTDM is beneficial in improving performance of pulse laser ranging and 3D imaging.

A QRS complex detection algorithm based on empirical mode decomposition (EMD) and adaptive windowing technique is proposed in this paper. In this algorithm we mainly used Hilbert-Huang transform to propose EMD method suitable for QRS complex detection, with which the 30th signal in sddb database and the 208th signal in mit-db database could be processed, and then obtained R wave detection results. At the same time, Q and S points' detection technique was analyzed with adaptive windowing technique. The detection results, through proceeding R wave detection on part data of MIT/BIT arrhythmia database, showed that the proposed algorithm in this paper had a very good detection effect, and that its average correct detection rate of R wave reached 99.62%, its average sensitivity of QRS complex was 98.91%, and the corresponding average specificity was 99.35%.

Gas generated beneath anodes in aluminum electrolytic cells play an important role for the circulation of the bath, alumina mixing, and heat balance. Those bubbles cause an extra voltage drop, which is strongly affected by the amount and shape of the bubbles beneath anodes. Consequently, understanding the dynamic behavior of bubbles in aluminum electrolytic cells has been a major research focus worldwide in recent decades.

The rapid diagnosis of tuberculosis (TB) and latent tuberculosis infections (LTBI) is a significant problem in clinical practice. The aim of this study was to evaluate the diagnostic value of an enzyme-linked immunosorbent spot (ELISPOT) assay measuring interferon-γ in hepatitis C patients with LTBI. A total of 160 hepatitis C patients at the Jilin University Hospital, Changchun, China, were prospectively enrolled from January 2009 to December 2010; 43 had been positively diagnosed with TB, 38 with non-TB diseases, and 79 with a history of TB. All patients were evaluated by the tuberculin skin test (TST) and ELISPOT assays. Among the 43 diagnosed TB patients, the ELISPOT assay had a sensitivity of 92.1%, compared to a sensitivity of 60.5% for the TST. Among the 79 TB exposure patients, the ELISPOT assay was more sensitive (90%) than the TST (61.5%), the specificity of the ELISPOT assay was 90%, and the specificity of the TST was 61.5% in LTBI. Among the 38 subjects with non-TB diseases, the specificity of the ELISPOT was better than the TST’s. In conclusion, this ELISPOT assay could provide useful support in diagnosing LTBI in hepatitis C patients and may provide guidance regarding the treatment of LTBI and hepatitis C co-infection. Key words: Latent tuberculosis infections (LTBI), Hepatitis C virus (HCV), enzyme-linked immunosorbent spot (ELISPOT) assay, CFP-10/ESAT-6

A remote ECG monitoring system design method based on GPRS wireless communication is proposed. This method mainly uses MSP430F2418 monolithic processor as controller, combined with SIM300 GPRS wireless communication module, through AT instructions to devise ECG monitoring instrument. Meanwhile, using VB6.0 and SQL Server2000 development tools based on Winsock network programming technique, design and develop remote ECG monitoring software in doctor workstation, realizing the remote monitoring of ECG signals. The ECG monitoring system has been applied to clinical trials, and getting the patient's approval.

Tuberculosis (TB) is still one of the most common causes of death in the world. The emergence of multidrug-resistant and extensively drug-resistant (XDR-TB) Mycobacterium tuberculosis (M. tuberculosis) strains has increased the importance of searching for alternative targets to develop new antimycobacterial drugs. Linezolid, the first of oxazolidinones, is active in vitro against M. tuberculosis, but the response mechanisms of M. tuberculosis to linezolid are still poorly understood. To reveal the possible mechanism of action of linezolid against M. tuberculosis, commercial oligonucleotide microarrays were used to analyze the genome-wide transcriptional changes triggered by treatment with subinhibitory concentrations of linezolid. Quantitative real-time RT-PCR was performed for selected genes to verify the microarray results. A total of 729 genes were found to be differentially regulated by linezolid. Among these, 318 genes were upregulated, and 411 genes were downregulated. A number of important genes were significantly regulated that are involved in various pathways, such as protein synthesis, sulfite metabolism, and genes involved in the cell envelope and virulence. This genome-wide transcriptomics approach produced the first insights into the response of M. tuberculosis to a linezolid challenge.

A new method of heart rate variability signal analysis based on Hilbert-Huang Transform (HHT) is proposed. Use EMD (Empirical Mode Decomposition) method to decompose signal into a series of IMF (Intrinsic Mode Function). By means of the given boundary conditions and EMD decomposition termination conditions, calculate and analyze instantaneous frequency and instantaneous amplitude of each IMF using HHT, obtain the intrinsic information contained in signal and the sudden change instant and the shifting trend of heart rate variability. Analyzing real heart rate signal with wavelet analysis and HHT method, the comparable experiment result proves that HHT method is feasible and shows its advantages with respect to wavelet analysis method.

According to the specific requirements of oil field power system parameter measurement, A monitoring system of power quality is designed based on ARM. The hardware design adopts ARM9 processor of SAMSUNG and TI's DSP processor, constructs double CPU architecture, and realizes data GPRS transmission through the SIM300 module. A regulatory center network monitoring software is designed using Borland C++ Builder 6.0 and client/server model, completing parameter display, storage and management with the Access database, and providing a friendly man-machine interface. The system can reduce the maintenance difficulty of oil field's electrical network and ensure the safety in oil field production.

In gastric cancer, several tumor suppressor and tumor-related genes are silenced by aberrant methylation. Previously, we demonstrated that BCL2L10, which belongs to the pro-apoptotic Bcl-2 family, was transcriptionally repressed by promoter hypermethylation and that its overexpression caused apoptosis and growth inhibition of gastric cancer cells. In this study, we investigated the methylation status of BCL2L10 and its expression in 21 gastric cancer tissues and corresponding non-neoplastic mucosae along with the methylation status of p16, RUNX3, and hMLH1 genes by using methylation specific PCR. In addition, we examined the association between the methylation status of each gene and the expression of EZH2, which was associated with DNA methylation of its target genes. As a result, aberrant methylation of BCL2L10 was detected in 38% of gastric cancer and in 24% of corresponding non-neoplastic mucosae and correlated with low expression of BCL2L10. Methylation of p16, RUNX3, and hMLH1 was found in gastric cancer and in corresponding non-neoplastic mucosae at almost similar frequencies as previous reports. Expression of EZH2 was detected more frequently in tumors (48%) as compared to corresponding non-neoplastic mucosae (10%) (p=0.006), however, no significant difference was found between expression of EZH2 and the methylation frequency of each gene. In conclusion, our data suggest that silencing of BCL2L10 by aberrant methylation is a common feature in gastric cancer and its inactivation may be involved in the early steps of gastric carcinogenesis.

To investigate the relationship between viral factors and the development of chronic hepatitis B, the entire hepatitis B virus (HBV) genome of chronic carriers at different disease stages were analyzed. Eighty genotype C HBV carriers including 12 hepatitis B e antigen (HBeAg) positive asymptomatic carriers (Group A), 49 HBeAg positive patients with chronic liver diseases (Group B) and 19 anti-HBe positive patients with chronic liver diseases (Group C) were studied. HBV nucleic acid from serum samples was sequenced directly and compared with GenBank reference sequences HBV X01587 and M12906. On phylogenetic analysis, 76 cases were genotype C2. Of the 76 genotype C2 cases, the nucleotide and amino acid substitution rates in the precore/core region were significantly higher in Groups B and C than in Group A, also in Group C than in Group B. The nucleotide substitution rates in the full genome and the core promoter region were significantly higher in Group C than in Group A, also in group C than in Group B. The nucleotide and amino acid substitution rates in the X region were significantly higher in Group C than in Group A. The amino acid substitution rate in the pre-S2 region was significantly higher in Group C than in Group B. Deletion mutations were found mainly in Groups B and C. This whole genome analysis of HBV chronic carriers suggested that the nucleotide substitutions and deletions in HBV were closely associated with the pathogenesis of chronic HBV infection. J. Med. Virol. 79: 683–693, 2007. © 2007 Wiley-Liss, Inc.

In gastric cancer, increasing numbers of genes have been reported to be silenced by aberrant methylation. However, global analysis of epigenetic inactivation in cancer cells has rarely been performed. For screening the genes upregulated by the demethylating agent 5-aza-2'-deoxycytidine (DAC), cDNA microarray analysis (AceGene(R), containing 30,000 genes) was performed using gastric cancer cell lines (AGS, MKN74, MKN1, MKN45 and Kato3) treated with DAC. The candidate upregulated genes were confirmed by real-time PCR, and the methylation status of 5'CpG islands was determined by bisulfite DNA sequencing or methylation-specific PCR. Among the upregulated genes considered to have CpG island in their promoter regions, we selected 5 genes (BCL2L10, DKK1, DNAJD1, GAGED2 and NMU) that exhibited a greater than 3-fold increase in at least 2 cell lines. Of these, we could determine the methylation status of 5'CpG islands of BCL2L10, DKK1 and DNAJD1. 5'CpG of BCL2L10 and DNAJD1 was hypermethylated in 4 of 5 gastric cancer cell lines, whereas 5'CpG of DKK1 was hypermethylated in only 1 cell line. MSP analysis for BCL2L10 revealed that the CpG island was demethylated after DAC treatment. In addition, we observed that overexpression of BCL2L10 could promote apoptosis and growth-inhibitory effect in gastric cancer cell lines. In conclusion, some of the genes upregulated by DAC treatment may be transcriptionally repressed by promoter hypermethylation. These genes might be related to gastric carcinogenesis. In particular, the suppression of BCL2L10, which could induce apoptosis and inhibit proliferation of cancer cells, might be one of the underlying mechanisms for gastric carcinogenesis.

BACKGROUND: The targeting of Staphylococcus aureus biofilm structures are now gaining interest as an alternative strategy for developing new types of antimicrobial agents. Magnolol (MOL) shows inhibitory activity against S. aureus biofilms and Triton X-100-induced autolysis in vitro, although there are no data regarding the molecular mechanisms of MOL action in bacteria. METHODOLOGY/PRINCIPAL FINDINGS: The molecular basis of the markedly reduced autolytic phenotype and biofilm inhibition triggered by MOL were explored using transcriptomic analysis, and the transcription of important genes were verified by real-time RT-PCR. The inhibition of autolysis by MOL was evaluated using quantitative bacteriolytic assays and zymographic analysis, and antibiofilm activity assays and confocal laser scanning microscopy were used to elucidate the inhibition of biofilm formation caused by MOL in 20 clinical isolates or standard strains. The reduction in cidA, atl, sle1, and lytN transcript levels following MOL treatment was consistent with the induced expression of their autolytic repressors lrgA, lrgB, arlR, and sarA. MOL generally inhibited or reversed the expression of most of the genes involved in biofilm production. The growth of S. aureus strain ATCC 25923 in the presence of MOL dose-dependently led to decreases in Triton X-100-induced autolysis, extracellular murein hydrolase activity, and the amount of extracellular DNA (eDNA). MOL may impede biofilm formation by reducing the expression of cidA, a murein hydrolase regulator, to inhibit autolysis and eDNA release, or MOL may directly repress biofilm formation. CONCLUSIONS/SIGNIFICANCE: MOL shows in vitro antimicrobial activity against clinical and standard S. aureus strains grown in planktonic and biofilm cultures, suggesting that the structure of MOL may potentially be used as a basis for the development of drugs targeting biofilms.