Surface plasmons resonance detection based on the attenuated total reflection geometry

AbstractThe conventional surface plasmons resonance(SPR) detection and the improved SPR detection were investigated, which were both based on the attenuated total reflection(ATR) geometry. The conventional detection system on Kretschmann configuration, can detect the dielectric constant changes of the medium near a metal film’s surface by measuring the intensity changes of the reflected beam. The improved SPR detection in a prism-multilayer configuration, which formed the long-range surface plasmon polaritions(SPPs) mode, provided the substantial improvement of the sensitivity and contrast of the detection over the conventional method that is of great benefit to the applications in various fields

Integrativna ekspresija gena za glukoamilazu u soju pivskoga kvasca Saccharomyces pastorianus

The recombinant brewer’s yeast Saccharomyces pastorianus strain was constructed byintroducing the ilv2:GLA fragment released from pMGI6, carrying glucoamylase gene (GLA) and using the yeast α-acetolactate synthase gene (ILV2) as the recombination sequence. The strain was able to utilise starch as the sole carbon source, its glucoamylase activity was 6.3 U/mL and its α-acetolactate synthase activity was lowered by 33.3 %. The introduced GLA gene was integrated at the recipient genomic ILV2 gene, one copy of ILV2 gene was disrupted and the other copy remained intact. Primary wort fermentation test confirmed that the diacetyl and residual sugar concentration in the wort fermented by the recombinant strain were reduced by 65.6 and 34.2 % respectively, compared to that of the recipient strain. Under industrial operating conditions, the maturation time of beer fermented by the recombinant strain was reduced from 7 to 4 days, there were no significant differences in the appearance and mouthfeel, and the beer satisfied the high quality demands. That is why the strain could be used in beer production safely.Uvođenjem ilv2:GLA isječka iz pMGI6, kao nosioca gena za glukoamilazu (GLA) i uporabom rekombinacijske sekvencije gena za α-acetolaktat sintazu (ILV2), konstruiran je rekombinantni soj pivskoga kvasca Saccharomyces pastorianus. Utvrđeno je da soj može koristiti škrob kao jedini izvor ugljika, da aktivnost glukoamilaze iznosi 6,3 U/mL, a da je aktivnost α-acetolaktat sintaze smanjena za 33,3 %. Uvedeni gen GLA, integriran u gen primatelja ILV2, raskinuo je jednu kopiju gena ILV2, dok je druga kopija ostala nepromijenjena. Prvi test fermentacije sladovine potvrdio je da je fermentacijom s pomoću rekombinantnog soja koncentracija diacetila smanjena za 65,6 %, a koncentracija ostatka šećera za 34,2 % u usporedbi sa sojem primatelja. U industrijskim uvjetima zrenje piva fermentiranog s pomoću rekombinantnog soja smanjeno je sa 7 na 4 dana, pri čemu nema značajne razlike u izgledu i okusu, te je ono zadovoljilo visoke zahtjeve. Stoga se ovaj soj može sigurno upotrijebiti u proizvodnji piva

Plasmons in Pb nanowire arrays on Si(557): Between one and two dimensions

The plasmon dispersion in arrays of nanowires of Pb close to an average Pb coverage of one monolayer was determined on the Si(557) surface using electron energy loss spectroscopy with both high energy and momentum resolution. While we find purely one-dimensional (1D) plasmon losses at a Pb concentration of 1.31 monolayers (ML), measured with respect to the Si(111) surface concentration, the 1.2 and 1.4 ML coverages exhibit wavelength-dependent transitions from 1D to anisotropic 2D properties. However, due to the high anisotropy in the system at all coverages, the dispersion curves exhibit 1D characteristics in both directions. This behavior seems to be related to the Pb-induced refacetting of the Si(557) surface, which depends on Pb coverage. It changes both effective system sizes and coupling strength between miniterraces. © 2011 American Physical Society.Ministry of Education, Culture, Sports, Science, and Technology, Japa

Job Satisfaction Among Methadone Maintenance Treatment Clinic Service Providers in Jiangsu, China: A Cross-sectional Survey.

ObjectiveService providers' job satisfaction is critical to the stability of the work force and thereby the effectiveness of methadone maintenance treatment (MMT) programs. This study aimed to explore MMT clinic service providers' job satisfaction and associated factors in Jiangsu, China.MethodsThis secondary study used baseline data of a randomized interventional trial implemented in Jiangsu, China. A survey was conducted among 76 MMT service providers using the computer-assisted self-interview (CASI) method. Job satisfaction responses were assessed via a 30-item scale, with a higher score indicating a higher level of job satisfaction. Perceived institutional support and perceived stigma due to working with drug users were measured using a 9-item scale. Correlation and multiple linear regression analyses were performed to identify factors associated with job satisfaction.ResultsCorrelation analyses found a significant association between job satisfaction and having professional experience in the prevention and control of HIV, other sexually transmitted infections, or other infectious diseases (P = 0.046). Multiple regression analyses revealed that working at MMT clinics affiliated with Center for Disease Control and Prevention sites was associated with a lower level of job satisfaction (P = 0.014), and perception of greater institutional support (P = 0.001) was associated with a higher level of job satisfaction.ConclusionJob satisfaction among MMT clinic service providers was moderate in our study. Our findings suggest that institutional support for providers should be improved, and that acquisition of additional expertise should be encouraged

Terahertz spectra revealing the collective excitation mode in charge-density-wave single crystal LuFe2 O4

We report a low-energy collective excitation mode in charge-ordered multiferroic LuFe2O4 via terahertz time domain spectroscopy. Upon cooling from 300 K to 40 K, the central resonance frequency showed a pronounced hardening from 0.85 THz to 1.15 THz. In analogy to the well-known low-energy optical properties of LuFe2O4, we attributed this emerging resonance to the charge-density-wave (CDW) collective excitations. By using the Drude-Lorentz model fitting, we observe the CDW col-lective mode becomes increasingly damped with increasing the temperature. Furthermore, we analyze the kinks of the CDW collective mode at the magnetic transition temperature, which indicates the coupling of spin order with electric polarization

Passive Localization of 3D Near-Field Cyclostationary Sources Using Parallel Factor Analysis

By exploiting favorable characteristics of a uniform cross-array, a passive localization algorithm of narrowband cyclostationary sources in the spherical coordinates (azimuth, elevation, and range) is proposed. Firstly, we construct a parallel factor (PARAFAC) analysis model by computing the third-order cyclic moment matrices of the properly chosen sensor outputs. Then, we analyze the uniqueness of the constructed model and obtain three-dimensional (3D) near-field parameters via trilinear alternating least squares regression (TALS). The investigated algorithm is well suitable for the localization of the near-field cyclostationary sources. In addition, it avoids the multidimensional search and pairing parameters. Results of computer simulations are carried out to confirm the satisfactory performance of the proposed method

Expression of peroxiredoxins in the human testis, epididymis and spermatozoa and their role in preventing H2O2-induced damage to spermatozoa

Introduction. High levels of reactive oxygen species (ROS) have potential toxic effects on testicular function and sperm quality. Peroxiredoxins (PRDXs) are enzymes with a role as ROS scavenger. The aim of the study was to reveal the presence and localization of PRDXs in human testis, epididymis and spermatozoa, and the protective roles of PRDX2 and PRDX6 in sperm motility. Material and methods. The presence and localization of PRDXs in the human testis, epididymis and spermatozoa were detected by immunohistochemistry, western blot and immunofluorescence. The effect of anti-peroxidative damage to spermatozoa was examined by adding H2O2 to the recombinant protein-treated spermatozoa. Results. There were strong signals of PRDX1 in spermatogonia and round spermatids; PRDX2 in the round spermatids; PRDX4 and 5 in spermatogonia; PRDX6 in Sertoli cells. PRDXs were also found in epididymal epithelial cells where the expression of PRDX1, 4, 5, 6 in the cauda was higher than in the caput of epididymis. PRDX1-6 immunoreactivity was found throughout acrosome, post-acrosomal region, equatorial segment, neck and cytoplasmic droplet, midpiece and principal piece. The H2O2-induced reduction in sperm motility was reversed by recombinant PRDX2 or PRDX6 in a dose-dependent manner. Conclusions. PRDX1-6 in the human testis and epididymis presented cell-specificity. PRDX2 and 6 are potential antioxidant protectors for human spermatozoa