Showing papers on "Liquid paraffin published in 2009"

The battle against multi-resistant strains: Renaissance of antimicrobial essential oils as a promising force to fight hospital-acquired infections

Abstract: Hospital-acquired infections and antibiotic-resistant bacteria continue to be major health concerns worldwide. Particularly problematic is methicillin-resistant Staphylococcus aureus (MRSA) and its ability to cause severe soft tissue, bone or implant infections. First used by the Australian Aborigines, Tea tree oil and Eucalyptus oil (and several other essential oils) have each demonstrated promising efficacy against several bacteria and have been used clinically against multi-resistant strains. Several common and hospital-acquired bacterial and yeast isolates (6 Staphylococcus strains including MRSA, 4 Streptococcus strains and 3 Candida strains including Candida krusei) were tested for their susceptibility for Eucalyptus, Tea tree, Thyme white, Lavender, Lemon, Lemongrass, Cinnamon, Grapefruit, Clove Bud, Sandalwood, Peppermint, Kunzea and Sage oil with the agar diffusion test. Olive oil, Paraffin oil, Ethanol (70%), Povidone iodine, Chlorhexidine and hydrogen peroxide (H(2)O(2)) served as controls. Large prevailing effective zones of inhibition were observed for Thyme white, Lemon, Lemongrass and Cinnamon oil. The other oils also showed considerable efficacy. Remarkably, almost all tested oils demonstrated efficacy against hospital-acquired isolates and reference strains, whereas Olive and Paraffin oil from the control group produced no inhibition. As proven in vitro, essential oils represent a cheap and effective antiseptic topical treatment option even for antibiotic-resistant strains as MRSA and antimycotic-resistant Candida species.

Chemopreventive efficacy of curcumin and piperine during 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

Abstract: Introduction: Oral carcinoma accounts for 40–50 percent of all cancers in India Tobacco chewing, smoking and alcohol consumption are the major risk factors associated with the high incidence of oral cancer in India Our aim was to investigate the chemopreventive potential of curcumin and piperine during 7,12-dimethylbenz[a]anthracene (DMBA) -induced hamster buccal pouch carcinogenesis Methods: Oral squamous cell carcinoma was developed in the buccal pouch of Syrian golden hamsters, by painting them with 05 percent DMBA in liquid paraffin, three times a week for 14 weeks The tumour incidence, tumour volume and burden were determined in the buccal pouches The status of phase II detoxification agents, lipid peroxidation and antioxidants were estimated by specific colorimetric methods

Simple colloidal synthesis of single-crystal Sb-Se-S nanotubes with composition dependent band-gap energy in the near-infrared.

Abstract: We report the first synthesis of high-quality binary and ternary Sb(2)Se(3-x)S(x) nanotubes across the entire compositional range from x = 0 to 3 via a simple, low-cost, colloidal synthetic method of injection of Sb(III)-complex solution into a hot paraffin liquid containing Se, S, or a mixture thereof. In contrast to the classic rolling mechanism, the modular formation of the reported nanotubes follows a four-stage self-seeding process: (i) amorphous nanospheres, (ii) short crystalline nanotubes growing out of relatively large amorphous nanospheres, (iii) long crystalline nanotubes attached to small amorphous nanospheres, and (iv) single-crystal nanotubes. The obtained single-crystal nanotubes have tunable composition, orthorhombic phase, well-defined rectangular cross sections, and growth direction along [001], as revealed by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected area electron diffraction studies. UV-vis-NIR absorption spectroscopy reveals that the optical bandgap energy of the Sb(2)Se(3-x)S(x) (0 < or = x < or = 3) nanotubes increases quadratically with the sulfur concentration x with these bandgap energies falling in the range from 1.18 to 1.63 eV at the red edge of the solar spectrum. The present study opens a new avenue to low-cost, large-scale synthesis of high quality semiconductor nanotubes with technological applications in solar energy conversion and also for a wide range of optical nanodevices operating in the near-infrared.

Electrodeposition of Co Nanoparticles on the Carbon Ionic Liquid Electrode as a Platform for Myoglobin Electrochemical Biosensor

Abstract: The electrochemical deposition of Co nanoparticles on carbon ionic liquid electrode (CILE) was described and further used as the platform to construct a myoglobin (Mb) electrochemical biosensor. CILE was prepared by mixing a certain ratio of carbon powder, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), and liquid paraffin together. The presence of ionic liquid on the electrode surface facilitated the formation of Co nanoparticles, and a layer of Co nanoparticles was deposited on the surface of CILE with the average diameter of 300 nm after the cyclic voltammetic scan in the CoCl2 solution. The formed Co/CILE was used as a new basal electrode for the investigation on the direct electrochemistry of protein. Mb molecules were further cast on the surface of Co/CILE and immobilized with Nafion film. The fabricated Nafion/Mb/Co/CILE showed good electrochemical behaviors with a pair of well-defined quasi-reversible redox peaks of Mb obtained, which was attributed to the electrochemical reaction of heme...

Reactive Extraction of Acrylic Acid Using Tri-n-butyl Phosphate in Different Diluents

Abstract: The increasing demand of carboxylic acid products is drawing great attention toward its recovery from waste streams/dilute solutions. With the above aim, the reactive extraction of acrylic acid from aqueous solutions using tri-n-butyl phosphate (TBP) in different diluents (paraffin liquid, toluene, and butyl acetate) was studied. The distribution coefficients and equilibrium extraction coefficients were obtained. Comparison was made on the basis of different physical properties of the solvents like molecular weight, dipole moment, dielectric constant, and ET parameter. Results show that higher values of distribution coefficients by chemical extraction were obtained for TBP in inert diluents: paraffin liquid and toluene.

Synthesis of two-dimensional single-crystal berzelianite nanosheets and nanoplates with near-infrared optical absorption

Abstract: The solar cell industry requires convenient and inexpensive fabrication of semiconductor nanostructures as highly efficient absorptive layers with low-cost, environmentally benign, heavy-metal-free (i.e., free from Hg, Cd, and Pb) and suitable band gap near 1 eV features. In this paper, we demonstrate the synthesis of two-dimensional single-crystal berzelianite (Cu2−xSe) nanosheets (in-plane diameter-to-thickness ratio ∼100) and nanoplates (in-plane diameter-to-thickness ratio ∼10) via a simple, “green” and environmentally benign method of injecting Cu(I)-complex precursor into Se-solution in paraffin liquid. Unlike the previous syntheses of binary chalcogenide nanostructures such as CdSe, the current strategy for berzelianite synthesis does not use expensive and toxic phosphine ligands such as trioctylphosphine (TOP). The products were characterized by a range of methods, such as X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected area electron diffraction, revealing that the products have the cubic phase and high-quality single-crystal two-dimensional nanostructure. UV-Vis-NIR absorption spectroscopy reveals that the nanosheets and nanoplates show obvious absorption onsets at 0.89 eV and 0.80 eV, respectively, and strong optical absorption peak at 1.70 eV and 1.62 eV, covering the whole red range of the solar spectrum. The present study opens a new avenue to “green” and low-cost controllable synthesis of binary chalcogenides with technological applications in solar energy conversion and also in a wide range of photonic devices operating in the near-infrared.

The tribological behavior of modified diamond nanoparticles in liquid paraffin

Abstract: Purpose – The purpose of this paper is to discuss the dispersion capacity and tribological behavior of liquid paraffin added by diamond nanoparticles.Design/methodology/approach – The structure of the modified diamond nanoparticles which are prepared by oleic acid (OA) is observed by scanning electron microscopy (SEM) and infrared spectroscopy (IR). The dispersivity of these nanoparticles in liquid paraffin is measured by nanoparticle analyzer. The tribological behavior of adding diamond nanoparticles in liquid paraffin is evaluated by using a ball‐on‐ring wear tester.Findings – The measurement results reveal the dispersion capability of OA modified diamond nanoparticles and indicate the dispersing stability in liquid paraffin of the OA which is bonded to the surface of diamond nanoparticles through esterification. It is found from wear testing results that the diamond nanoparticle as additive in liquid paraffin at proper concentration shows better tribological properties for anti‐wear (AW) and antifricti...

Preparation of Uniformly Sized Chitosan Nanospheres by a Premix Membrane Emulsification Technique

Abstract: Chitosan nanospheres have great potential in drug controlled release systems, because they show excellent degradability, biocompatibility, and nontoxicity. The particle size control and size distribution of nanospheres are necessary in order to improve reproducibility, bioavailability, and repeatable release behavior. In order to prepare uniformly sized and size-controllable chitosan nanospheres, in this study, a premix membrane emulsification technique was developed on the basis of direct membrane emulsification, and the uniformly sized chitosan nanospheres were successfully prepared by optimizing preparation conditions. The detail preparation process is as follows: The chitosan aqueous solution was used as a dispersed phase, and the mixture of liquid paraffin and petroleum ether containing emulsifier was used as a continuous phase. The coarse emulsions were first prepared by low-speed stator homogenization and then poured into the premix reservoir. Nanodroplets were achieved by extruding the coarse emulsions through the SPG (Shirasu porous glass) membrane with a high pressure. The nanodroplets were further cross-linked to obtain chitosan nanospheres. In this process, several factors played key roles in obtaining chitosan nanoparticles with narrow size distribution, including the amounts of emulsifier in oil phase, the composition of oil phase, the concentration of chitosan, the ratio of water to oil phase, the transmembrane pressure and number of passes, and so on. The results showed that the chitosan nanospheres from 300 nm to 1.85 mu m were successfully prepared by premix membrane emulsification by changing the pore size of the membrane and the polydispersity index could be as low as 0.027 under optimized conditions, and it is a potential technique to prepare size-controllable uniform chitosan nanospheres with fast production.

Phosphine-Free Synthesis of High-Quality CdSe Nanocrystals in Noncoordination Solvents: Activating Agent and Nucleating Agent Controlled Nucleation and Growth

Abstract: CdSe nanocrystals (NCs) are prepared in noncoordination solvents (1-octadecene (ODE) and paraffin liquid) with long-chain primary alkylamine as the sole ligand, ODE-Se, and cadmium fatty acid salt as precursors. The obtained NCs meet the four fundamental parameters for high-quality NCs: high crystallinity, narrow size distribution, moderate photoluminescence quantum yield, and broad range size tunableness. Further, by simply regulating the relative molar ratio of alkylamine to cadmium precursor, the regular sized “nuclei” and final obtained NCs can be produced predictably within a certain size range. The size distribution of regular sized “nuclei” is very narrow (fwhm = 23 ± 1 nm), and the following focusing growth procedure vanishes. This indicates a different nucleation and growth kinetics from that of the well-established “focusing” and “defocusing” theory. By analyzing the conversion factor of precursors and the concentration of magic sized nanoclusters and regular sized “nuclei”, a subtle secondary n...

Cross-contamination in the molecular detection of Bartonella from paraffin-embedded tissues.

Abstract: The genus Bartonella comprises a group of gram-negative, fastidious bacteria. Because of diagnostic limitations of culture and serologic testing, polymerase chain reaction (PCR) has become a powerful tool for the detection of Bartonella spp. in blood and tissue samples. However, because many wild and domestic animals harbor Bartonella spp., transfer of Bartonella DNA during sample collection or histologic processing could result in false-positive PCR test results. In this study, we describe evidence of Bartonella DNA dissemination and transfer in the necropsy room and during the subsequent processing of formalin-fixed paraffin-embedded tissues. Bartonella DNA was amplified from different areas of the necropsy room, from the liquid paraffin in the tissue processor, and from different parts of the microtome. Unless stringent procedures are established and followed to avoid cross-contamination, the molecular detection of Bartonella spp. from tissue samples obtained at necropsy or processed in a multispecies histopathology laboratory will not be reliable.

Phase Behavior, Formation, and Rheology of Cubic Phase and Related Gel Emulsion in Tween80/Water/Oil Systems

Abstract: We investigated the phase behavior, formation, and rheology of the cubic phase (I1) and related O/I1 gel emulsion in water/Tween 80/oil systems using squalane, liquid paraffin (LP), and decane as oil components. In the phase behavior study, the phase sequences were similar for squalane and LP systems, while a lamellar liquid crystal (Lα) was observed for decane system. In all the systems the addition of oil to Wm or H1 phase induced the I1 phase, which can solubilize some amounts of oil followed by the appearance of I1+O phase. The formation of the O/I1 gel emulsion has been studied at a fixed w/s (50/50) and we found that 30 wt% decane, 70 wt% squalane, and 60 wt% LP can form the gel emulsion. The water/Tween 80/squalane system has been taken as a model system to study viscoelastic properties of the I1 phase and O/I1 gel emulsion. The I1 phase shows a typical hard gel cubic structure under the frequency and the values of the complex viscosity, ¦η*¦ and the elastic modulus, G ′ increase with the addition of squalane, which could be due to the neighboring micellar interaction. On the other hand, the decreasing values of the viscoelastic parameters in the O/I1 gel emulsion simply relate to the volume fraction of the I1 phase in the system.

Response of Arginine Vasopressin‐Enhanced Green Fluorescent Protein Fusion Gene in the Hypothalamus of Adjuvant‐Induced Arthritic Rats

Abstract: Arginine vasopressin (AVP) and corticotrophin-releasing hormone (CRH) in the parvocellular neurosecretory cells of the paraventricular nucleus (PVN) play a major role in activating the hypothalamic-pituitary-adrenal axis, which is the main neuroendocrine response against the many kinds of stress. We examined the effects of chronic inflammatory/nociceptive stress on the expression of the AVP-enhanced green fluorescent protein (eGFP) fusion gene in the hypothalamus, using the adjuvant arthritis (AA) model. To induce AA, the AVP-eGFP rats were intracutaneously injected heat-killed Mycobacterium butyricum (1 mg/rat) in paraffin liquid at the base of their tails. We measured AVP, oxytocin and corticosterone levels in plasma and changes in eGFP and CRH mRNA in the hypothalamus during the time course of AA development. Then, we examined eGFP fluorescence in the PVN, the supraoptic nucleus (SON), median eminence (ME) and posterior pituitary gland (PP) when AA was established. The plasma concentrations of AVP, oxytocin and corticosterone were significantly increased on days 15 and 22 in AA rats, without affecting the plasma osmolality and sodium. Although CRH mRNA levels in the PVN were significantly decreased, eGFP mRNA levels in the PVN and the SON were significantly increased on days 15 and 22 in AA rats. The eGFP fluorescence in the SON, the PVN, internal and external layers of the ME and PP was apparently increased in AA compared to control rats. These results suggest that the increases in the concentrations of ACTH and corticosterone in AA rats are induced by hypothalamic AVP, based on data from AVP-eGFP transgenic rats.

Emulsifying properties of gum kondagogu (Cochlospermum gossypium), a natural biopolymer

Abstract: BACKGROUND: Natural polymers are widely used as emulsifying agents in the food and pharmaceutical industries because of their low cost, biocompatibility and non-toxic nature. In the present study, emulsifying properties of the novel natural biopolymer gum kondagogu (GKG) were investigated. GKG solutions of different concentrations (0.1–0.6% w/v) were prepared in water and emulsified with liquid paraffin oil (40% v/v) in a high-speed homogeniser. Flow properties of the emulsions were measured using a rheometer. Emulsion stability and droplet size distribution were determined by visual observation, photomicrography and laser-scattering particle size distribution analysis. RESULTS: The emulsions prepared with GKG showed pseudoplastic behaviour. The size of oil droplets and the viscosity of emulsions at concentrations of 0.4–0.6% w/v showed little change over time (up to 30 days), indicating that the emulsions were stable. Measurements of the zeta potential of emulsions adjusted to different pH, with and without added electrolyte, showed that the stabilisation of emulsions with GKG was due to mutual repulsion between electrical double layers of particles and adsorption of macromolecules on oil droplets. CONCLUSION: The results of this experimental investigation show that GKG is a good emulsifying agent even at low concentrations, with many potential applications in the food and pharmaceutical industries. Copyright © 2009 Society of Chemical Industry

Microspheres with pH modulated release: Design and characterization of formulation variables for colonic delivery

Abstract: The aim of this study was to design and develop microspheres of indomethacin with pH and transit time dependent release properties for achieving targeted delivery to the colon. Microspheres containing varying proportions of ethyl cellulose and Eudragit (L100 or S100) either alone or in combination were prepared using an oil-in-oil emulsion-based solvent evaporation technique. System comprising of acetone (internal phase) and liquid paraffin (external phase) in the ratio of 1 : 1 and 1 : 9 yielded microspheres with good physical properties (spherical and discrete), high drug loading (70–80%) and entrapment efficiency (70–85%). The lag time in the initial release depended on the proportion of pH-sensitive polymer Eudragit, while the duration of indomethacin release from microspheres was found to be directly proportional to proportion of the total polymer. Thus, a pH- and time-modulated sigmoidal release pattern could be observed in optimized formulations with less than 10% drug release in 4–6 h foll...

Self circulation heat exchange method for materials in production of chlorinating paraffin-52 and chlorination reaction device therefor

Abstract: The invention provides a self circulation heat exchange method for materials in production of chlorinating paraffin-52 and a chlorination reaction device therefor The method comprises the steps that: a, liquid paraffin is added into an automatic circulation main and auxiliary chlorination reaction kettle provided with a catalytic light source and a heat exchanger outside the kettle, and a catalytic light source lamp is turned on; b, liquid chlorine is introduced into a gasification kettle, stabilized by an accumulator still, and is introduced into a main kettle of the chlorination reaction kettle at a chlorine flowrate of between 200 and 230Kg/h, the chlorination temperature is controlled to be between 100 and 110 DEG C, the reaction is stopped when the chlorine content analyzed in a taken sample is between 50 and 54 percent to obtain a crude product of the chlorinating paraffin-52, dissolved chlorine and chlorine hydride in the crude product of the chlorinating paraffin-52 are removed by a degasification kettle, and then a stabilizing agent is added to obtain a finished product of the chlorinating paraffin-52; and c, gas coming out of the main kettle of the chlorination reaction kettle enters an auxiliary kettle of the chlorination reaction kettle, gas coming out of the auxiliary kettle of the chlorination reaction kettle passes through a graphitic absorber, a water falling film is used for absorbing the chlorine hydride in the gas to prepare hydrochloric acid, micro chlorine and chlorine hydride contained in tail gas which is discharged by the graphic absorber pass through a waste gas processor and are absorbed by water solution of sodium hydroxide to generate sodium hypochlorite and sodium chloride

Elemental distribution analysis of urinary crystals

Abstract: Various crystals are seen in human urine. Some of them, particularly calcium oxalate dihydrate, are seen normally. Pathological crystals indicate crystal formation initiating urinary stones. Unfortunately, many of the relevant crystals are not recognized in light microscopic analysis of the urinary deposit performed in most of the clinical laboratories. Many crystals are not clearly identifiable under the ordinary light microscopy. The objective of the present study was to perform scanning electron microscopic (SEM) assessment of various urinary deposits and confirm the identity by elemental distribution analysis (EDAX). 50 samples of urinary deposits were collected from urinary stone clinic. Deposits containing significant crystalluria (more than 10 per HPF) were collected under liquid paraffin in special containers and taken up for SEM studies. The deposited crystals were retrieved with appropriate Pasteur pipettes, and placed on micropore filter paper discs. The fluid was absorbed by thicker layers of filter paper underneath and discs were fixed to brass studs. They were then gold sputtered to 100 A and examined under SEM (Jeol JSM 35C microscope). When crystals were seen, their morphology was recorded by taking photographs at different angles. At appropriate magnification, EDAX probe was pointed to the crystals under study and the wave patterns analyzed. Components of the crystals were recognized by utilizing the data. All the samples analyzed contained significant number of crystals. All samples contained more than one type of crystal. The commonest crystals encountered included calcium oxalate monohydrate (whewellite 22%), calcium oxalate dihydrate (weddellite 32%), uric acid (10%), calcium phosphates, namely, apatite (4%), brushite (6%), struvite (6%) and octocalcium phosphate (2%). The morphological appearances of urinary crystals described were correlated with the wavelengths obtained through elemental distribution analysis. Various urinary crystals that are not reported under light microscopy could be recognized by SEM-EDAX combination. EDAX is a significant tool for recognizing unknown crystals not identified by ordinary light microscopy or SEM alone.

Desulphurization and denitration catalyst and preparation method thereof

Abstract: The invention discloses a desulphurization and denitration catalyst. The catalyst comprises the following components by mass percentage: 4 to 18 percent of CuO, 80 to 95 percent of gamma-Al2O3, and 1 to 2 percent of promoter. A method for preparing the catalyst comprises the following steps: (1) adding aluminum isopropoxide into distilled water, stirring the mixture, adding a nitric acid solution into the mixture dropwise, and carrying out the evaporation in the air to obtain a boehmite sol; (2) adding the promoter into a copper nitrate solution, then adding the mixture into the boehmite sol, then adding the nitric acid solution dropwise, stirring the mixed solution for ageing, and aggregating the mixed solution into a semi-gel; and (3) adding the semi-gel dropwise into a gel pool containing ammonia water and liquid paraffin through a dropper, and obtaining the catalyst after ageing, drying and baking. The prepared catalyst can be used for synchronous desulphurization and denitration, and can be regenerated and used cyclically with low raw material cost. As the byproducts can be reutilized, the catalyst brings about no secondary pollution.

Adsorption of CO on Cu (110) and (100) surfaces using COSMO-based DFT.

Abstract: Density functional theory (DFT) combined with the conductor-like solvent model (COSMO) can provide valuable atomistic level insights into CO adsorption on Cu surface interactions in liquid paraffin. The objective of this research was to investigate the solvent effect of liquid paraffin. It was found that both structural parameters and relative energies are very sensitive to the COSMO solvent model. Solvent effects can improve the stability of CO adsorption on Cu (110) and (100) surfaces and the extent of CO activation.

Photodynamics of a PV trimer in high-viscosity solvents and in PMMA films: a new insight into energy transfer versus conformational relaxation in conjugated polymers.

Abstract: Non-Stokes–Einstein relaxation: The rate constant of conformational relaxation of a phenylenevinylene trimer (see picture) in different solvents is proportional to η−α, with α values decreasing from close to unity (low viscosity) to zero at sufficiently high solvent viscosity. This behaviour is attributed to the flexible methylbutyl side chains of the trimer, which partially screen the solvent friction. The p-phenylenevinylene (PV) trimer (MBOPV3) was used to probe the effect of conformational relaxation on fluorescence decays of PV-based polymers in the high solvent viscosity regime, from n-hexadecane (3.45 cP at 293 K) to liquid paraffin (123 cP at 293 K), and in dilute poly(methyl methacrylate) (PMMA) solid films. The effect of intermolecular energy transfer and radiative transport on the fluorescence decays was also analysed by increasing the concentration of MBOPV3 in the PMMA films up to a pure MBOPV3 film. The rate constant of conformational relaxation was found to decrease with increasing solvent viscosity up to about 23 cP, but then becomes viscosity independent. The non-Stokes–Einstein behaviour of kCR versus η over the whole viscosity range apparently results from the presence of the flexible methylbutyl side chains of MBOPV3, which partially screens the solvent friction. Conformational relaxation is not observed in very dilute PMMA solid films, where the fluorescence decay becomes single exponential. The decays become multi-exponential again with an increase of MBOPV3 concentration in the PMMA films, but in this case it is due to intermolecular (interchain) energy transfer from less planar to more planar conformations of MBOPV3. In the pure MBOPV3 film, interchain energy transfer (radiative and non-radiative) is the major process responsible for the observed (tetra-exponential) decays.