Identification of Amino Acid Residues in Influenza A Virus PA-X That Contribute to Enhanced Shutoff Activity

The influenza virus protein PA-X modulates the host immune responses and viral pathogenicity through suppression of host protein expression. The endonuclease active site in the N-terminal region, the basic amino acid cluster in the C-terminal PA-X-specific region, and N-terminal acetylation of PA-X by NatB are important for the shutoff activity of PA-X. Here, we focused on the shutoff activity of PA-X derived from the A/California/04/2009 and A/WSN/33 viruses because these two PA-X proteins differ in their shutoff activity. Mutagenesis analysis revealed that proline and serine at positions 28 and 65, respectively, play a central role in this difference. Furthermore, we found that P28 and S65 also affect the shutoff activity of PA-X derived from other influenza virus subtypes. These data demonstrate that P28 and S65 contribute to enhanced shutoff activity of PA-X

Improved Analysis of Manganese in Steel Samples Using Collinear Long–Short Double Pulse Laser-Induced Breakdown Spectroscopy (LIBS)

A long-short double pulse laser-induced breakdown spectroscopy (long-short DP-LIBS) method was employed to improve the performance of LIBS for the measurement of manganese in steel samples. The long pulse was generated by a Nd:YAG laser which was operated at free runing (FR) mode. To investigate the detection ability without sample preparation, the steel washers were tested using SP-LIBS and long-short DP-LIBS, respectively. The measurement results show that the long-short DP-LIBS method was able to record clear spectra from the rusty steel washers. The steel washers were also measured after the polishing process. The measurement results show that the signal intensity was enhanced by long-short DP-LIBS. Through the observation with scanning electron microscope (SEM) on the laser craters, the results suggest that the improvement of detection ability can be attributed to the pre-radiation effect of long-pulse laser beam. Next, the analytical performance for quantitative measurement of manganese was evaluated by employing ten standard steel samples. The results show that the linearty fit (R2) of calibration curve is 0.988 for long-short DP-LIBS, whereas, R2 is only 0.810 for SP-LIBS under the same measurement conditions. The five times repeated measurement results show that the average Relative Standard Deviation (RSD) of the tested samples is 29.3% for SP-LIBS and is 10.5% for long-short DP-LIBS. The prediction results also show that the average Relative Error of Prediction (REP) is 94.9% for SP-LIBS and it 4.9% for long-short DP-LIBS. The experimental results in current work demonstrate that long-short DP-LIBS is promising for the on line measurement of steel in the steelmaking plant

Feasibility Investigation for Online Elemental Monitoring of Iron and Steel Manufacturing Processes using Laser-Induced Breakdown Spectroscopy

The metallurgical industries are very important for social development. In order to improve the metallurgical techniques and quality of products, the real-time analysis and monitoring of iron and steel manufacturing processes are very significant. Laser-induced breakdown spectroscopy (LIBS) has been studied and applied for the contents measurement of iron and steel. In this paper, the remote open-path LIBS measurement was studied under different sample temperature, lens to target distance (LTD), sample angle conditions to clarify its online measurement features. The 3D profile measurement system of parallel laser beam fringes projection was also developed to measure the sample profile at different sample temperature. The measurement results demonstrated the robustness of remote open-path LIBS system and 3D profile measurement system. However, the correction is necessary to enhance the detection ability of LIBS online measurement. In order to improve the precision and accuracy of real-time elemental measurement, an innovative co-axial laser beam measurement system combining LIBS and 3D profile techniques is proposed to automatically adjust the focus unit and measure the sample components. The further study of this promising method will be developed for online application of iron and steel manufacturing processes

Isolation and Characterization of Human Monoclonal Antibodies That Recognize the Influenza A(H1N1)pdm09 Virus Hemagglutinin Receptor-Binding Site and Rarely Yield Escape Mutant Viruses

The influenza A virus rapidly mutates to escape from antibodies. Here, we isolated and characterized three human monoclonal antibodies (mAbs) that neutralize A(H1N1)pdm09 viruses. Generation of escape mutant viruses suggested that these antibodies recognized conserved residues of the receptor-binding site (RBS) of hemagglutinin (HA) and that mutant viruses that escaped from these mAbs rarely appeared. Moreover, the escape mutant viruses grew significantly slower than wild-type virus, indicating their reduced fitness. These results indicate that these three human mAbs against the RBS of HA have the potential to be anti-influenza agents with a low propensity for the development of resistant viruses

Quantitative Elemental Analysis Using Long-Short Double-Pulse Laser Induced Breakdown Spectroscopy

鉄鋼プロセス，ボイラなどの様々な産業プロセスにおいて，物質の元素組成をリアルタイムで計測可能な技術が求められている．鉄鋼プロセスでは，鉄鉱石，コークス，石灰石などを原料として，鋼板などを製造する過程で各プロセス中の成分組成を計測することが求められ，溶融金属の組成などをリアルタイム制御することなどが重要となる．しかし，現在まで，これらの産業プロセスで元素組成をリアルタイムで計測可能な技術や装置は実用化されていない．レーザーを用いた非接触，リアルタイム計測方法として，レーザー誘起ブレークダウン分光法(Laser Induced Breakdown Spectroscopy，LIBS)がある．本研究では，LIBSを用いた元素組成の定量計測を目的に，ロング・ショートダブルパルスLIBSの開発を行った．本手法を鋼材中のマンガン及び炭素計測に適用し，計測の安定性，定量性に優れた特性を有することを実証した．The understanding of the controlling factors is becoming more important to improve the efficiency of industrial systems including steel-making processes, boilers and so on. Laser diagnostics such as laser-induced breakdown spectroscopy (LIBS) makes it possible to monitor these parameters due to their fast response, high sensitivity, and non-contact features. In this study, a new collinear long and short double pulse LIBS method was developed to improve the detection ability and the measurement accuracy by the control of the plasma cooling process using the long pulse-width laser radiation. The plasma generated by the short pulse-width laser is stabilized and maintained at high temperature during the plasma cooling process by long pulse-width laser radiation. The method was demonstrated to have better measurement stability and quantitative measurement characteristics for Manganese and Carbon measurement in the steel samples compared to the normal single pulse LIBS method

AGEs activate mesangial TGF-β–Smad signaling via an angiotensin II type I receptor interaction

AGEs activate mesangial TGF-β–Smad signaling via an angiotensin II type I receptor interaction.BackgroundThe renin-angiotensin system (RAS) and the accumulation of advanced glycation end products (AGEs) have been implicated in the pathogenesis of diabetic nephropathy. Whether there is a functional interaction between the RAS and AGEs in diabetic nephropathy is not known. In this study, we investigated whether AGEs could activate autocrine angiotensin II (Ang II) signaling and subsequently induce transforming growth factor-β (TGF-β)–Smad signaling in cultured rat mesangial cells.MethodsThe intracellular formation of reactive oxygen species (ROS) was detected using the fluorescent probe CM-H2DCFDA. Ang II was measured by radioimmunoassay. TGF-β released into media was quantitatively analyzed in an enzyme-linked immunosorbent assay (ELISA). Smad2, p27Kip1 (p27), fibronectin, and receptor for AGEs (RAGE) protein expression were determined by Western blot analysis. TGF-β–inducible promoter activity was analyzed by a luciferase assay. DNA synthesis was evaluated by 5-bomo-2′-deoxyuridine (BrdU) incorporation and de novo protein synthesis was determined by [3H]leucine incorporation.ResultsAGEs increased intracellular ROS generation in mesangial cells, and this effect was significantly inhibited by an antiserum against RAGE. AGEs also were found to stimulate Ang II production in a time- and dose-dependent manner, which was completely prevented by an antioxidant, N-acetylcysteine (NAC). AGE-induced TGF-β overproduction was completely blocked by candesartan, an Ang II type 1 receptor (AT1R) antagonist. Both candesartan and neutralizing antibody against TGF-β completely prevented AGEs-induced Smad2 phosphorylation and TGF-β–inducible promoter activity. Furthermore, AGEs were found to inhibit DNA synthesis and to stimulate de novo protein synthesis and fibronectin production in association with up-regulation of p27. All of these phenomena were completely prevented by candesartan or a polyclonal antibody against TGF-β.ConclusionThe present study suggests that AGE-RAGE–mediated ROS generation activates TGF-β–Smad signaling and subsequently induces mesangial cell hypertrophy and fibronectin synthesis by autocrine production of Ang II. This pathway may provide an important link between metabolic and haemodynamic factors in promoting the development and progression of diabetic nephropathy

Detection Improvement of Unburned Carbon Content in Fly Ash Flow Using LIBS with a Two-Stage Cyclone Measurement System

Fly ash contents can be considered as a basis for optimal and stable boiler combustion control and fly ash quality control in power plant, especially the unburned carbon in fly ash. The real-time and quantitative measurement of contents in fly ash was studied using a constructed two-stage cyclone measurement system and detected using laser-induced breakdown spectroscopy(LIBS) technique. The surrounding gas effect, such as CO2 effect on unburned carbon content, was studied comprehensively in this paper. The CO2 effect was eliminated using this proposed combination method of two-stage cyclone measurement system and LIBS with 1ns pulse-width laser according to the efficient gas-particle separation and the controlled laser-induced plasma processes of particle flow. The quantitative analysis was improved using the plasma temperature correction method with the intensity ratio of the emission pair from magnesium as a plasma temperature indicator. The measurement of unburned carbon content in fly ash with temperature correction method presented the concordant results analyzed by chemical analysis method. It is demonstrated the feasibility and improved detection ability for the real-time measurement of fly ash contents in power plant

Unburned carbon measurement in fly ash using laser-induced breakdown spectroscopy with short nanosecond pulse width laser

The unburned carbon in fly ash is one of the important factors for the boiler combustion condition. Controlling the unburned carbon in fly ash is beneficial for fly ash recycle and to improve the combustion efficiency of the coal. Laser-induced breakdown spectroscopy (LIBS) technology has been applied to measure the fly ash contents due to its merits of non-contact, fast response, high sensitivity, and real-time measurement. In this study, experimental measurements have been adopted for fly ash flows with the surrounding gases of N2 and CO2, while the CO2 concentration varified to evaluate the CO2 effect on the unburned carbon signal from fly ash powder. Two kinds of pulse width lasers, 6ns and 1ns, were separately adopted to compare the influence of laser pulse width. Results showed that compared with 6ns pulse width laser, plasma temperature was lower and had less dependence on delay time when using 1ns pulse width laser, and spectra had more stable background. By using 1ns pulse width laser, the emission signal from surrounding CO2 also decreased because of the less surrounding gas breakdown. The solid powder breakdown signals also became more stable when using 1ns pulse width laser. So it is demonstrated that 1ns pulse width laser has the merits for fly ash flow measurement using LIBS

Metagenomic analysis of bacterial species in tongue microbiome of current and never smokers

Cigarette smoking affects the oral microbiome, which is related to various systemic diseases. While studies that investigated the relationship between smoking and the oral microbiome by 16S rRNA amplicon sequencing have been performed, investigations involving metagenomic sequences are rare. We investigated the bacterial species composition in the tongue microbiome, as well as single-nucleotide variant (SNV) profiles and gene content of these species, in never and current smokers by utilizing metagenomic sequences. Among 234 never smokers and 52 current smokers, beta diversity, as assessed by weighted UniFrac measure, differed between never and current smokers (pseudo-F = 8.44, R² = 0.028, p = 0.001). Among the 26 species that had sufficient coverage, the SNV profiles of Actinomyces graevenitzii, Megasphaera micronuciformis, Rothia mucilaginosa, Veillonella dispar, and one Veillonella sp. were significantly different between never and current smokers. Analysis of gene and pathway content revealed that genes related to the lipopolysaccharide biosynthesis pathway in Veillonella dispar were present more frequently in current smokers. We found that species-level tongue microbiome differed between never and current smokers, and 5 species from never and current smokers likely harbor different strains, as suggested by the difference in SNV frequency