Synthesis of Gold Nanoparticles in Presence of Poly(vinyl pyrrolidone) from Gold Hydroxide Precursor Salt

Since the discovery, gold nanoparticles (GNPs) have been attracting scientific and research communities owing to their biocompatibility, excellent thermal conductivity, low cytotoxicity, ease of processability, and highly functionalization capability. In this report, we discuss synthesis of gold nanoparticles with poly(vinyl pyrrolidone) (PVP) in 1–butanol from gold hydroxide, a new precursor salt. An emergence of a strong surface plasmon absorption band at 535 nm confirms formation of GNPs in the colloidal solution. The stability of Au colloid was studied by using UV–Visible and zeta potential measurements. The interfacial interaction between GNP and PVP molecules was studied in terms of Fourier transform infrared and X–ray photoemission spectrum (XPS). Marked enhancement in some of the vibrational bands (e.g., C=O, C–H, and C–N stretching) of PVP molecules in presence of GNPs reveals existence of an interaction between this two major constituents. However a small red-shift in the C=O stretching frequency of pyrrolidone group of PVP molecule implies that a weak interaction occurs via O–atom of carbonyl group. Appearance of Au4f doublet band at 82.7 and 86.4 eV in XPS spectrum with a chemical shift of 3.7 eV further confirms formation of GNPs by reduction of Au3+ to Au0 chemical state in presence of PVP. A noticeable negative shift in the binding energies of Au4f doublet band as compared to bulk Au atom suggests an interfacial interaction between GNP and PVP molecules. Transmission electron microscopic images propose that Au crystalline core is covered by an amorphous layer of PVP molecules.

The Human Cationic Antimicrobial Protein (hCAP-18) Is Expressed in the Epithelium of Human Epididymis, Is Present in Seminal Plasma at High Concentrations, and Is Attached to Spermatozoa

ABSTRACT Innate immunity is important for the integrity of the host against potentially invasive pathogenic microorganisms in the environment. Antibiotic peptides with broad antimicrobial activity are part of the innate immune system. We investigated the presence of the cathelicidin, human cationic antimicrobial protein (hCAP-18), in the male reproductive system. We found strong expression of the hCAP-18 gene by in situ hybridization and hCAP-18 protein, as detected by immunohistochemistry, in the epithelium of the epididymis, but not in the testis. The highest expression in the epididymis was in the caudal part. Western blotting showed a doublet band, the upper part corresponding to the size of hCAP-18 in plasma and neutrophils. Using a specific enzyme-linked immunosorbent assay (ELISA), levels of 86.5 ± 37.8 μg/ml (mean ± standard deviation; range, 41.8 to 142.8 μg/ml; n = 10) were detected in seminal plasma from healthy donors, which is 70-fold higher than the level in blood plasma. Flow cytometry and immunocytochemistry revealed the presence of hCAP-18 on spermatozoa. ELISA measurement showed levels of 196 ng/106 spermatozoa, corresponding to 6.6 × 106 molecules of hCAP-18 per spermatozoon. Our results suggest a key role for hCAP-18 in the antibacterial integrity of the male reproductive system. The attachment of hCAP-18 to spermatozoa may implicate a role for hCAP-18 in conception.

Two-Dimensional Correlation Analysis, Fourier Self-Deconvolution, and Second-Derivative Studies on Assignments of the CH2 Stretching Bands for Cast Films of 2-Dodecyl-, 2-Pentadecyl-, and 2-Octadecyl-7,7,8,8-Tetracyanoquinodimethane

Infrared spectra have been measured for cast films of three kinds of 2-alkyl-7,7,8,8-tetracyanoquinodimethanes (C nTCNQ) prepared on KBr plates. Each infrared spectrum shows two components for the CH2 antisymmetric stretching band (2926 and 2918 cm−1), and the relative intensity of the two bands changes with the length of the alkyl chain. In contrast to the characteristic doublet band in the antisymmetric stretching band region, only one band seems to appear near 2850 cm−1 in the corresponding CH2 symmetric stretching band region. In order to reveal the number of the bands appearing in the CH2 antisymmetric and symmetric stretching regions and to explore the origins of these bands, Fourier self-deconvolution (FSD) and second-derivative methods have been applied to the infrared spectra of the cast films. The FSD analysis of the spectra for the three kinds of C nTCNQ derivatives measured at a 4 cm−1 resolution demonstrates that the CH2 symmetric stretching band also consists of two components (near 2853 and 2848 cm−1). The same conclusion has been obtained by the second derivative of the spectra measured at 1 cm−1 resolution. An asynchronous two-dimensional (2D) correlation spectrum created from time-dependent infrared spectra for a one-layer Langmuir–Blodgett (LB) film develops cross peaks at (2927 and 2916 cm−1) and (2854 and 2846 cm−1), suggesting that the bands at 2927 and 2916 cm−1 come from different species and those at 2854 and 2846 cm−1 also have different origins. The bands at 2918 and 2848 cm−1 may be due to the interdigitated part of the alkyl chain in the cast film, which has ordered ( trans-zigzag) form, while the bands near 2926 and 2853 cm−1 are probably ascribed to the noninterdigitated part of the alkyl chain, which has disordered form with several gauche conformations.

Purification and characterization of an 82-kD membrane protein as a neurite outgrowth factor binding protein: possible involvement of NOF binding protein in axonal outgrowth in developing retina.

Neurite outgrowth factor (NOF) is a glycoprotein isolated from an extract of gizzard that induces neurite outgrowth from cultured retinal or ciliary ganglionic (CG) neurons. We have reported that a glycoprotein of approximately 82 kD solubilized from gizzard muscles binds to NOF (ligand blotting) and inhibits the neurite promoting activity of NOF (inhibition assay). The 82-kD protein (NOF binding protein) was purified from gizzard muscle membranes as a doublet band on SDS-PAGE and a polyclonal antibody was raised against it. An NOF binding protein in developing retina exhibited the same physicochemical properties as that of the gizzard muscle. Quantitative decrease in NOF binding protein in embryonic retinas was observed after day 11 by the inhibition assay, ligand blotting, and immunoblotting, its decrease being parallel with reduction of NOF-induced neurite outgrowth of embryonic retinas. In an immunohistochemical study, the antibody stained only the optic fiber layers of the retinas of 8-d embryos, and this staining was no longer detectable in retinas of 18-d embryos. These results suggest that the 82-kD protein is a novel membrane protein that behaves as an NOF receptor and that the loss of neuritic response of the retinal neurons to NOF reflects a decrease in NOF receptor molecules.

Spectroscopic confirmation of orientational disorder of the cyanide groups in sodium cyanide dihydrate, NaCN•2H2O

Occurrence of orientational disorder involving the CN groups in NaCN•2H2O, suggested by van Rij and Britton on the basis of a refinement of X-ray diffraction data, has been confirmed by the doubling of CN stretching fundamentals. The ratios of doublet band areas are consistent with the energy of the orientation [Formula: see text] being higher than that of the "normal" orientation, [Formula: see text] by 800 ± 300 cal mol−1.

Investigations on the vibration spectra of certain condensed gases at the temperature of liquid nitrogen II. The infra-red and Raman spectra of hydroand deuterochloric acid at liquid nitrogen temperatures

The infra-red absorption spectrum of solid hydrochloric acid has been obtained at the temperature of liquid nitrogen (i.e. approximately 20° below its transition point), in the region of the fundamental frequency. The results obtained agree in general with the earlier observations of Hettner and disagree with those of Shearin who reported discrete rotation lines. The doublet band observed by Hettner has been resolved into two separate bands with maxima at 2701 and 2744 cm. -1 and indications of a third band were obtained. Some fine structure very different from that reported by Shearin was observed on each of the two bands which were unsymmetrical in shape, being steeper on the low frequency side. The Raman spectrum was obtained at the same temperature and also showed a doublet structure in contrast to earlier observations at higher temperatures which had given only a single line. The maxima of the Raman lines lay at 2709 and 2759 cm. -1 . The explanation of this doubling is to be sought in the manner in which the hydrochloric acid molecules associate in the solid state, since the alteration in the fundamental frequency from that found in the gaseous state shows that strong interaction must exist. The absorption due to the fundamental frequency of deuterochloric acid was observed under the same conditions. Here three maxima were obtained at 1965, 1982 and 1992 cm. -1 and indications of more structure. These results show that the association of HCl and DCl molecules in the crystal below the transition temperature can probably take place in several different ways. Such a conclusion is in agreement with the X-ray investigations which revealed a symmetry so low that the crystalline structure could not be determined.