Avidin conjugation to up-conversion phosphor NaYF4:Yb3+, Er3+ by the oxidation of the oligosaccharide chains

NaYF4:Yb3+, Er3+ nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with SiO2-NH2 layer, these NaYF4:Yb3+, Er3+ nanoparticles can conjugate with activated avidin molecules (activated by the oxidation of the oligosaccharide chain). The as-formed NaYF4:Yb3+, Er3+ nanoparticles, NaYF4:Yb3+, Er3+ nanoparticles functionalized with amino groups, avidin conjugated amino-functionalized NaYF4:Yb3+, Er3+ nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), UV/Vis absorption spectra, and up-conversion luminescence spectra, respectively. The biofunctionalization of the NaYF4:Yb3+, Er3+ nanoparticles has less effect on their luminescence properties, i.e., they still show the up-conversion emission (from Er3+, with S-4(3/2) -> I-4(15/2) at similar to 540 nm and F-4(9/2) -> I-4(15/2) at similar to 653 nm), indicative of the great potential for these NaYF4:Yb3+, Er3+ nanoparticles to be used as fluorescence probes for biological system.

Conversion from electronic conducting phase to redox conducting phase of polypyrrole

Square-wave voltommetry is used to study the oxidation of polypyrrole doped with dodecylsulfate. The net current curve in this experiment shows why the oxidation current does not display the capacitive-like shape common in cyclic voltammetry. In cyclic voltammetry, the redox behavior of polypyrrole is attributed to the size of dodecylsulfate, irreversible incorporation and the complete consumption of dodecylsulfate. After the polypyrrole film was scanned in aqueous NaCl solution, square wave voltammetric measurements show different results, indicating the change of the polymer nature with regard to the charge transport. This is explained by anion replacement, exclusion and the change of the charge transport mechanism.

A field study on the conversion ratio of phytoplankton biomass carbon to chlorophyll-a in Jiaozhou Bay, China

A one-year field study was conducted to determine the conversion ratio of phytoplankton biomass carbon (Phyto-C) to chlorophyll-a (Chl-a) in Jiaozhou Bay, China. We measured suspended particulate organic carbon (POC) and phytoplankton Chl-a samples collected in surface water monthly from March 2005 to February 2006. The temporal and spatial variations of Chl-a and POC concentrations were observed in the bay. Based on the field measurements, a linear regression model II was used to generate the conversion ratio of Phyto-C to Chl-a. In most cases, a good linear correlation was found between the observed POC and Chl-a concentrations, and the calculated conversion ratios ranged from 26 to 250 with a mean value of 56 A mu g A mu g(-1). The conversion ratio in the fall was higher than that in the winter and spring months, and had the lowest values in the summer. The ratios also exhibited spatial variations, generally with low values in the near shore regions and relatively high values in offshore waters. Our study suggests that temperature was likely to be the main factor influencing the observed seasonal variations of conversion ratios while nutrient supply and light penetration played important roles in controlling the spatial variations.

Light energy conversion into H-2 by Anabaena variabilis mutant PK84 dense cultures exposed to nitrogen limitations

Concentrated cultures (25-86 mg Chl a l(-1)) of Anabaena variabilis PK84 were incubated under 99% Ar+1% CO2 atmosphere in the photobioreactor made of coaxial cylinders. Under illumination equal to 353 mu E m(-2) s(-1) they produced hydrogen with the rate more than 20 ml l(-1) h(-1) for several days. The efficiency of light energy conversion into H-2 was approx. 1% and did not depend significantly on initial Chl a concentration. H-2/O-2 ratio reached 41.5% of theoretical value for water photolysis. Data indicate that dense cultures might be used for outdoor systems under direct sun light. Supra-optimal temperatures 36 degrees C were not harmful for cultures even for 2 days period. Short-term incubation of cultures under 36 degrees C even increased H2 production rate and efficiency of light energy bioconversion by 1.25 times. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.

Methanol to olefin conversion catalysts

The past year has seen remarkable advances both in methanol to olefin process development and in understanding the catalysts and reactions invoked. The methanol to olefin process is now on the way to being commercialized locally with economic advantages in comparison with other natural gas utilization technologies and conventional naphtha cracking processes. Using a specially designed procedure, a catalyst for the selective synthesis of ethylene from methanol has been reliably reproduced. The relationships between catalyst properties and reaction performances are clearer than ever before.

Rambo's Interdisciplinary Approach to Religious Conversion: The Case of St. Augustine

This dissertation illustrates the merits of an interdisciplinary approach to religious conversion by employing Lewis Rambo’s systemic stage model to illumine the process of St. Augustine’s conversion. Previous studies of Augustine’s conversion have commonly explored his narrative of transformation from the perspective of one specific discipline, such as theology, history, or psychology. In doing so, they have necessarily restricted attention to a limited set of questions and problems. By bringing these disciplines into a structured, critical conversation, this study demonstrates how formulating and responding to the interplay among personal, social, cultural, and religious dimensions of Augustine’s conversion process may eventuate in the consideration of issues previously unarticulated and thus unaddressed. Rambo (1993) formulates a model of religious change that consists of what he calls context, crisis, quest, encounter, interaction, commitment, and consequences. Change is explained by drawing upon the research and scholarship of psychologists, sociologists, anthropologists, and religionists, in conjunction with the contributions of theologians. This study unfolds in the following chapters: I. Introduction; II. Literature review of scholarship about conversion, with emphasis on explication of Rambo’s model; III. A description of the case of Augustine, drawn from a close reading of the Confessions; IV. Literature review of scholarship about Augustine’s conversion; V. Interdisciplinary interpretation of Augustine’s conversion; and VI. Implications for scholars of conversion, and for pastoral caregivers, as well as recommendations for future research. This dissertation demonstrates how Augustine’s conversion experience was deeply influenced by 1) psychological distress and crisis; 2) the quest to know himself and the divine; 3) interactions with significant others; 4) participation in Christian communities; 5) philosophical and cultural changes; and 6) the encounter with the divine. As such, this study reveals the value of interpreting Augustine’s conversion as an evolving process constituted in multiple factors that can be differentiated from one another, yet clearly interact with one another. It examines the implications of constructing an interdisciplinary approach to Augustine’s conversion narrative for both the academy and the Christian community, and recommends the use of Rambo’s model in studies of other cases of religious change.

Conversion of natural forests to managed forest plantations decreases tree resistance to prolonged droughts

© 2015 Published by Elsevier B.V.Throughout the southern US, past forest management practices have replaced large areas of native forests with loblolly pine plantations and have resulted in changes in forest response to extreme weather conditions. However, uncertainty remains about the response of planted versus natural species to drought across the geographical range of these forests. Taking advantage of a cluster of unmanaged stands (85-130year-old hardwoods) and managed plantations (17-20year-old loblolly pine) in coastal and Piedmont areas of North Carolina, tree water use, cavitation resistance, whole-tree hydraulic (Ktree) and stomatal (Gs) conductances were measured in four sites covering representative forests growing in the region. We also used a hydraulic model to predict the resilience of those sites to extreme soil drying. Our objectives were to determine: (1) if Ktree and stomatal regulation in response to atmospheric and soil droughts differ between species and sites; (2) how ecosystem type, through tree water use, resistance to cavitation and rooting profiles, affects the water uptake limit that can be reached under drought; and (3) the influence of stand species composition on critical transpiration that sets a functional water uptake limit under drought conditions. The results show that across sites, water stress affected the coordination between Ktree and Gs. As soil water content dropped below 20% relative extractable water, Ktree declined faster and thus explained the decrease in Gs and in its sensitivity to vapor pressure deficit. Compared to branches, the capability of roots to resist high xylem tension has a great impact on tree-level water use and ultimately had important implications for pine plantations resistance to future summer droughts. Model simulations revealed that the decline in Ktree due to xylem cavitation aggravated the effects of soil drying on tree transpiration. The critical transpiration rate (Ecrit), which corresponds to the maximum rate at which transpiration begins to level off to prevent irreversible hydraulic failure, was higher in managed forest plantations than in their unmanaged counterparts. However, even with this higher Ecrit, the pine plantations operated very close to their critical leaf water potentials (i.e. to their permissible water potentials without total hydraulic failure), suggesting that intensively managed plantations are more drought-sensitive and can withstand less severe drought than natural forests.

Reduction in gingival overgrowth associated with conversion from cyclosporin A to tacrolimus

Background: Unsightly gingival overgrowth affects many individuals immunosuppressed with cyclosporin A (CsA), Current management involves repeated periodontal surgery and intensive hygienist support. Tacrolimus is an effective alternative immunosuppressive agent for renal transplantation which does not appear to produce gingival enlargement.