221 research outputs found

    Sulfuric Acid and Ammonia Generation by Bipolar Membranes Electrodialysis: Transport Rate Model for Ion and Water through Anion Exchange Membrane

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    Regeneration of sulfuric acid and ammonia from ammonium sulfate by bipolar membrane electrodialysis (BMED) coupling with stripping ammonia by air-blowing was studied. The result showed that it was feasible to regenerate sulfuric acid and ammonia from ammonium sulfate solution using this method. Empirical models to describe the ion and water transport behaviors through anion exchange membrane for BMED system were successfully developed. The models were valid to evaluate water transport rate and ion transport behavior for anion exchange membrane under similar operation conditions. Comparison of calculated values with experimental data indicated that the models were reliable to describe the water and ion transport behavior through anion exchange membrane for BMED system and also be used to predict the water transport and ion transport behaviors for other current density under similar operation condition

    Using conditional random fields to extract contexts and answers of questions from online forums

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    Online forum discussions often contain vast amounts of questions that are the focuses of discussions. Extracting contexts and answers together with the questions will yield not only a coherent forum summary but also a valuable QA knowledge base. In this paper, we propose a general framework based on Conditional Random Fields (CRFs) to detect the contexts and answers of questions from forum threads. We improve the basic framework by Skip-chain CRFs and 2D CRFs to better accommodate the features of forums for better performance. Experimental results show that our techniques are very promising.

    Loop-mediated isothermal amplification for detection of porcine circovirus type 2

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    <p>Abstract</p> <p>Background</p> <p>Porcine circovirus type 2 (PCV2) is the primary causative agent of the emerging swine disease known as postweaning multisystemic wasting syndrome (PMWS). Nowadays, polymerase chain reaction (PCR) is still the most widespread technique in pathogen detection. Loop-mediated isothermal amplification (LAMP), a novel nucleic acid amplification method developed in 2000, will possibly replace PCR in the field of detection. To establish a LAMP method for rapid detection of PCV2, two pairs of primers were designed specially from the open reading frame 2 (ORF2) sequences of PCV2. A LAMP method for rapid detection of PCV2 was established. To compare with PCR, sensitivity and specificity of LAMP were evaluated using the optimized reaction system. The LAMP products could be determined by agarose gel electrophoresis or adding SYBR Green I dye.</p> <p>Results</p> <p>The amplification of LAMP could be obtained at 63°C for 60 min. The detection limit was nearly 1 copy of DNA plasmid, more sensitive than PCR. There was no cross-reaction with porcine circovirus type 1 (PCV1), porcine pseudorabies virus (PRV) and porcine parvovirus (PPV) under the same conditions.</p> <p>Conclusions</p> <p>LAMP is an useful rapid detection method with high sensitivity and specificity for PCV2.</p

    Analysis of the correlation between the pavement structure combinations and pavement performance using experimental sections

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    The new generation of pavement technology with the goal of longevity is an important supporting technology that can promote the achievement of sustainable development of high-speed roadways. To further investigate the evolution trend of long-life pavement performance, this paper paved experimental sections to explore the correlations between pavement structure combinations and pavement performances. This paper presented four experimental sections with different pavement structures, asphalt concrete layer thicknesses, and pavement materials. Then, this paper analyzed the effects of the seasonal factors, pavement structure, and lanes on the deflection value and rut depth from three dimensions by the Pearson correlation coefficient (PCC). Finally, this paper used the analysis of variance (ANOVA) to analyze the relationships between the layer thickness of various materials in the pavement structure and the pavement performances, including the deflection value, international roughness index (IRI), texture depth (TD), British Pendulum Number (BPN), sideway force coefficient (SFC), rut depth, and disease area. The results showed that the seasonal factors significantly affected the deflection values of pavement structures with PCCs of 0.61, 0.72, 0.53, and 0.78. The high temperatures increased the average deflection values by 22.85%, 72.88%, 77.61%, and 88.13%, respectively. Under the influence of high temperature in summer and traffic loads, the increased ranges of average rut depth were −0.2%, 4.89%, 9.56%, and 7.31%, respectively. The results of ANOVA showed that the pavement structure type and thickness of each structural layer significantly affected the deflection value, and there also was a strong correlation between the pavement structure type, thickness, BPN, and SFC with p-values less than 0.05. Increasing the thickness of the asphalt surface was beneficial for reducing the area of defects, while laying the semi-rigid base layer was beneficial for maintaining the deflection value and rut depth at a lower level

    Fast determination of polybrominated diphenyl ethers residues in milk by dispersive solid phase extraction and isotope labeled internal standard-gas chromatography-tandem mass spectrometry

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    Objective A 13C isotope labeled internal standard-gas chromatography-tandem mass spectrometric (GC-MS/MS) with dispersive solid phase extraction (d-SPE) method was developed for the simultaneous determination of 7 polybrominated diphenyl ethers (PBDEs) residues in milk. Methods After adding13C12 isotope internal standard and extracted with 1% acetic acid acetonitrile, purified with the new Z-Sep+C18 dispersive agent, the analytes in the sample solutions were seperated by DB-5 column (30 m×0.25 mm, 0.25 μm). Operated by electron impact ion source (EI) with multiple reactions monitoring (MRM) mode, the samples were analyzed by gas chromatography-tandem mass spectrometer. The quantifications were performed by the isotope internal standard method with matrix-matched calibration standards. Results Good linearity was obtained for 7 PBDEs in the concentration range of 0.500-100 ng/mL with correlation coefficients (r) above 0.999. Recoveries for 7 PBDEs at three spiked levels of 0.1, 1.0, and 10 μg/kg were in the range of 89.7%-102.9% with relative standard deviations (RSDs, n = 6) of 3.8%-8.3%. The limits of detection and the limits of quantification were in the ranges of 2.4-9.8 and 7.5-30 ng/kg, respectively. Conclusion The established method was simple, efficient and sensitive, and could be applied in the determination of 7 PBDEs in milk

    Porcine Reproductive and Respiratory Syndrome in Hybrid Wild Boars, China

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    We conducted a serologic investigation of porcine reproductive and respiratory syndrome virus (PRRSV) in hybrid wild boar herds in China during 2008–2009. PRRSV isolates with novel genetic markers were recovered. Experimental infection of pigs indicated that hybrid wild boars are involved in the epidemiology of PRRSV

    Research Progress on the Effect of New Electrophysical Processing on Multiscale Protein Structure

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    Protein is an important nutrient required by the human body. The change of protein structure during processing will lead to changes in its functional properties, in turn affecting the quality of foods. There are many physical methods available to alter the structure of proteins to expand their application in the food industry. The new electrophysical processing technology has become a hot spot in the field of food processing due to its advantages of high efficiency, low energy consumption, and slight loss of nutrients. Therefore, this paper reviews the effects of electric field technology (ohmic heating and electrostatic field) and electromagnetic field technology (microwave, radio frequency and magnetic field) on the change of protein structure at multiscales (macroscopic, molecular and microscopic levels), in order provide a theoretical basis for the development and utilization of electromagnetic field processed protein products

    Retinoic Acid Induced Protein 14 (Rai14) is dispensable for mouse spermatogenesis

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    Background Retinoic Acid Induced Protein 14 (Rai14) is an evolutionarily conserved gene that is highly expressed in the testis. Previous experiments have reported that small interfering RNA (siRNA)-mediated gene knockdown (KD) of Rai14 in rat testis disrupted spermatid polarity and transport. Of note, a gene knockout (KO) model is considered the “gold standard” for in vivo assessment of crucial gene functions. Herein, we used CRISPR/Cas9-based gene editing to investigate the in vivo role of Rai14 in mouse testis. Methods Sperm concentration and motility were assayed using a computer-assisted sperm analysis (CASA) system. Histological and immunofluorescence (IF) staining and transmission electron microscopy (TEM) were used to visualize the effects of Rai14 KO in the testes and epididymides. Terminal deoxynucleotidyl transferase-dUTP nick-end labeling (TUNEL) was used to determine apoptotic cells. Gene transcript levels were calculated by real-time quantitative PCR. Results Rai14 KO in mice depicted normal fertility and complete spermatogenesis, which is in sharp contrast with the results reported previously in a Rai14 KD rat model. Sperm parameters and cellular apoptosis did not appear to differ between wild-type (WT) and KO group. Mechanistically, in contrast to the well-known role of Rai14 in modulating the dynamics of F-actin at the ectoplasmic specialization (ES) junction in the testis, morphological changes of ES junction exhibited no differences between Rai14 KO and WT testes. Moreover, the F-actin surrounded at the ES junction was also comparable between the two groups. Conclusion In summary, our study demonstrates that Rai14 is dispensable for mouse spermatogenesis and fertility. Although the results of this study were negative, the phenotypic information obtained herein provide an enhanced understanding of the role of Rai14 in the testis, and researchers may refer to these results to avoid conducting redundant experiments
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