Insoluble Precipitate Research Articles

49 Metallic Soap Aggravates Skin Conditions in Patients With Atopic Dermatitis and a Mouse Model for Human Atopic Dermatitis, NC/TND Mice

BackgroundHardness in water is consisted with mineral salts, including calcium (Ca++) and magnesium (Mg++). The mineral salts react with soap to form an insoluble precipitate known as metallic soap (soap scum). Since metallic soap remains tightly on the skin and is hard to rinse off, it may become one of irritants that exacerbate dermatitis. In this study, we used cation-exchange resin to prepare ultra-pure soft water (UPSW) excluding both Ca++ and Mg++, and investigated effect of UPSW rinsing on skin conditions in subjects with atopic dermatitis. Furthermore, antigenic activity of metallic soap was investigated by in vivo experiments.MethodsStratum corneum was collected from arms of healthy volunteers who rinsed soap in tap water or UPSW, and the quantity of remained soap scum was determined with a gas chromatography. After 4 weeks of bathing in UPSW, the water content of the stratum corneum and transepidermal water loss (TEWL) of volunteers with mild atopic dermatitis were measured. With atopic NC/Tnd mice, a model for atopic dermatitis, we attempted to confirm results obtained from atopic volunteers. Plasma total IgE was measured by an ELISA after immunization of mice with metallic soap.ResultsOn skins rinsed in UPSW, soap was disappeared immediately and remained metallic soap was significantly reduced when compared to that on skins rinsed in tap water. In skins of atopic volunteers who used UPSW for bath, the water content in stratum corneum was increased and TEWL was decreased. Skin dryness and itch scores were reduced in most volunteers. After washed with soap and rinsed in UPSW for 2 weeks, severe dermatitis of NC/Tnd mice were reduced as well as TEWL. On the other hand, dermatitis in NC/Tnd mice rinsed in tap water became worse. Plasma total IgE was increased in mice that were immunized with metallic soap.ConclusionsUPSW protected skins from residue of metallic soap. Metallic soap has antigenic activity and increased plasma IgE levels. Clinical symptoms and the skin barrier function were improved by the use of soap with UPSW. UPSW is beneficial for the skin of patients with atopic dermatitis.

Precipitate from a combination of sodium hypochlorite and chlorhexidine

During the cleaning and shaping of the root canal, various irrigants have been used to reduce the residual debris, necrotic tissue, and bacteria, as well as to remove smear layer. Though sodium hypochlorite (NaOCl) is the most common irrigant used in root canal treatment, chlorhexidine (CHX) has been suggested as either an alternative or an adjunct root canal irrigant because of its antimicrobial qualities and substantivity. A combination of NaOCl and CHX for root canal irrigation has been advocated to enhance their antimicrobial properties. Zehender proposed an irrigation regimen as the following: 2.5% NaOCl during instrumentation, and a final flush of the canals is performed in the sequence of 17% EDTA, 2.5% NaOCl, and 2% CHX. However, the presence of NaOCl in the canals during irrigation with CHX produces an orange-brown precipitate known as parachloroaniline (PCA) (Figure 1). The precipitate occludes the dentinal tubules and may compromise the seal of the obturated root canal. Leaching of PCA from the insoluble precipitate is of concern because it has been shown to be cytotoxic in rats and possibly carcinogenic in humans (International Agency for Research on Cancer group 2B). A

Calcium Phosphate Transfection of Eukaryotic Cells

[Abstract] Transfection of DNA into cells is an indispensible protocol in molecular biology. While plenty of lipid-based transfection reagents are commercially available nowadays, a quick, simple, efficient and inexpensive method is to transfect eukaryotic cells via calcium phosphate coprecipitation with DNA (Graham and van der Eb, 1973). The insoluble calcium phosphate precipitate with the attached DNA adheres to the cell surface and is brought into the cells by endocytosis. Calcium phosphate transfection has been optimized and widely used with many adherent and nonadherent cell lines (Jordan et al., 1996). Calcium phosphate transfection can result in transient expression of the delivered DNA in the target cell, or establishment of stable cell lines (the latter requires a drug selection process). This protocol is also widely used for coexpression of plasmids for packaging viruses. Efficiency of transfection can be close to 100% depending on the cell lines used. Here, a calcium phosphate transfection protocol is described using a GFP plasmid and the HEK293 cell line.

Sequestration of Zinc from Zinc Oxide Nanoparticles and Life Cycle Effects in the Sediment Dweller Amphipod Corophium volutator

We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism.

Behavior of fission products in the course of dissolution of simulated spent nuclear fuel in iron nitrate solutions and of recovery of uranium and plutonium from the resulting solutions

Experiments aimed to examine the spent nuclear fuel dissolution in iron(III) nitrate solutions and to elucidate the behavior of fission products in the process were performed with simulated fuel corresponding to spent nuclear fuel of a WWER-1000 reactor. In Fe(III) nitrate solutions, U is quantitatively transferred from the fuel together with Cs, Sr, Ba, Y, La, and Ce, whereas Mo, Tc, and Ru remain in the insoluble precipitate and do not pass into the solution, and Nd, Zr, and Pd pass into the solution to approximately 50%. The recovery of U or jointly U + Pu from the solution after the dissolution of oxide nuclear fuel is performed by precipitation of their peroxides, which allows efficient separation of actinides from residues of fission products and iron.

Conversion of veratrole and sodium lignosulfonate in the sub- and supercritical water

The conversion of veratrole and sodium lignosulfonate (SLS) in sub-and supercritical water at temperatures of 200–430°C, pressure of 220 atm, and residence time in the reactor of 2.5–10 min is studied. The soluble products of SLS depolymerization are analyzed by HPLC and GC-MS. Thermogravimetric, elemental, IR, and 1H NMR analyses of the insoluble products of the conversion of SLS in supercritical water (SCW) are performed. It is demonstrated that the methoxyaryl ether bonds and aromatic structures do not undergo destruction in SCW. The formation of the insoluble precipitate is explained by decarboxylation and desulfonation of lignin polymer fragments.

A new route to preparation of palladium catalysts for VOC combustion

Methyltheophylline is known to be effective and highly selective extractant for Pd in the solvent extraction process. The high selectivity for Pd extraction might be due to the formation of chelate complex of Pd and methyltheophylline. The chelate complexes made insoluble precipitate in organic solvent when it became a certain condition. Partially-oxidized Pd nanoparticles below 100 nm were obtained by calcination of the precipitate. Pd/γ-Al 2O 3 and Pd/cordierite honeycomb catalysts were prepared by conventional impregnation method using the organic solvent containing Pd extracted from aqueous solution, and their catalytic activities for toluene combustion were compared with that of the Pd catalysts prepared from PdCl 2 aqueous solution. Consequently, the Pd catalyst prepared by using Pd extracted organic solvent showed remarkably higher activity for toluene combustion than that prepared from PdCl 2 aqueous solution.

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, ( DippL)ZnEt ( 3, DippL = [(2,6- iPrC 6H 3)NC(CH 3)] 2CH −), a product assigned as the zinc-phosphide ( DippL)ZnPHPh ( 6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex ( TolL)ZnEt ( 2, TolL = [(p-CH 3C 6H 4)NC(CH 3)] 2CH −) was reacted with primary phosphines to give a precipitate and the bis( β-diketiminate)zinc complex ( TolL) 2Zn ( 5), an apparent product of comproportionation. ( MesAI)ZnEt ( 1, MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.

A one-step electrochemical method for DNA detection that utilizes a peroxidase-mimicking DNAzyme amplified through PCR of target DNA

A novel one-step electrochemical method for DNA detection is described. The procedure utilizes a reaction catalyzed by a peroxidase-mimicking DNAzyme to produce a product, which forms an insoluble precipitation layer on the surface of an electrode. A rationally designed forward primer, conjugated with a peroxidase DNAzyme complementary sequence at its 5′-end, is used for PCR amplification of target DNA. As a result, the DNAzyme sequence is produced by amplification only when the target DNA is present in the sample. The PCR product is then subjected to the precipitation reaction on the electrode surface using an electrolyte assay buffer containing 4-chloronaphthol, hydrogen peroxide, ferrocenemethanol, hemin, and 5′-lambdaexonuclease. Finally, analysis is carried out using Faradaic impedance spectroscopy. The impedance value was found to greatly increase when target DNA is present owing to the formation of a precipitation layer on the electrode surface caused by the catalytic action of the DNAzyme. In contrast, no impedance increase is observed when a control sample not containing target DNA is utilized. By employing this strategy, target DNA from Chlamydia trachomatis was reliably detected within a 10 min period following precipitation without the need for complicated secondary procedures. This effort has led to the development of a highly convenient electrochemical one-step method for DNA detection that utilizes a peroxidase-mimicking DNAzyme, which is specifically designed to undergo amplification during PCR of target DNA.

Pilot-scale ex situ electrokinetic restoration of saline greenhouse soil

This study was conducted to investigate the feasibility of using an ex situ electrokinetic system for the restoration of saline greenhouse soil. An experiment was conducted in a pilot-scale reactor (1 × 1 × 0.25 m) during 14 days. Chloride accumulated in the top layer through pore-water evaporation. There was no removal of the nitrate in the top layer because of the continuous upward transport of nitrate accompanying the evaporation of soil moisture. However, the removal of sulfate was uniform across all the layers. In the case of cations, a significant amount (64.4%) of potassium was removed, and there was no removal of the magnesium in the top layer. The electrokinetic treatment changed the speciation of calcium in the soil, resulting in an increase in the amount of exchangeable calcium. Furthermore, nitrate was transported toward the anode and reduced to nitrogen gas as the result of an electrochemical reaction at the surface of the anode. Sulfate formed a very stable and insoluble precipitate with calcium—calcium sulfate (gypsum). Ex situ electrokinetic system removed salts from nitrate and sulfate-accumulated saline soil. However, the overall removal efficiency was not high enough because of relatively short operation time.

Sulfosalicylate mediates improved vinorelbine loading into LUVs and antineoplastic effects

Liposomal vinorelbine formulation is desirable, as it might improve the therapeutic activity of vinorelbine. However, because of its lipophilic and membrane-permeable properties, vinorelbine is hard to be formulated into liposomes using conventional drug-loading technologies. To improve vinorelbine retention, ammonium salts of several anionic agents were employed to prepare liposomal vinorelbine formulations. It was found that 5-sulfosalicylate (5ssa) could form stable complexes with vinorelbine and stabilize entrapped vinorelbine. The resultant vesicles had an in vitro release t1/2 of ~12.49 hours in NH3-containing media, which is longer than those of sulfate and phytate vesicles (~0.57 hours). The circulation half-life of vinorelbine after the injection of 5ssa vesicles into normal mice was ~13.01 hours, accounting for ~2-fold increase relative to that of sulfate vesicles. Improved drug retention correlated with enhanced antitumor efficacy. In the RM-1/c57 model, 5ssa vesicles were more efficacious than sulfate vesicles (P < 0.05). In RM-1/BDF1 and Lewis lung cancer/c57 models, antitumor efficacy was also considerably improved after vinorelbine encapsulation into 5ssa vesicles. For instance, in the RM/BDF1 model, liposomal vinorelbine was at least 4-fold more therapeutically active than free vinorelbine. Our results demonstrated that 5ssa could stabilize vinorelbine relative to other anions, resulting in the formulation with improved drug retention and efficacy. Improved vinorelbine retention might be associated with the formation of insoluble precipitate, which could be proved by precipitation study and decreased drug-release rate at a high D/L ratio.

Asymmetric Michael additions of aldehydes to maleimides using a recyclable fluorous thiourea organocatalyst

Fluorous thiourea organocatalyst 3 promotes the Michael reaction of aldehydes with maleimides to afford the corresponding adducts in high yields with up to 99% ee. Fluorous organocatalyst 3 can be easily recovered as an insoluble precipitate from the reaction mixture by simple filtration and can be reused without significant loss of catalytic activity.

Rapid Detection of Haptoglobin Gene Deletion in Alkaline-Denatured Blood by Loop-Mediated Isothermal Amplification Reaction

Anhaptoglobinemic patients run the risk of severe anaphylactic transfusion reaction because they produce serum haptoglobin antibodies. Being homozygous for the haptoglobin gene deletion allele (HP(del)) is the only known cause of congenital anhaptoglobinemia, and detection of HP(del) before transfusion is important to prevent anaphylactic shock. In this study, we developed a loop-mediated isothermal amplification (LAMP)-based screening for HP(del). Optimal primer sets and temperature for LAMP were selected for HP(del) and the 5' region of the HP using genomic DNA as a template. Then, the effects of diluent and boiling on LAMP amplification were examined using whole blood as a template. Blood samples diluted 1:100 with 50 mmol/L NaOH without boiling gave optimal results as well as those diluted 1:2 with water followed by boiling. The results from 100 blood samples were fully concordant with those obtained by real-time PCR methods. Detection of the HP(del) allele by LAMP using alkaline-denatured blood samples is rapid, simple, accurate, and cost effective, and is readily applicable in various clinical settings because this method requires only basic instruments. In addition, the simple preparation of blood samples using NaOH saves time and effort for various genetic tests.

Revised Mechanism of Boyland−Sims Oxidation

New computational insights into the mechanism of the Boyland-Sims oxidation of arylamines with peroxydisulfate (S(2)O(8)(2-)) in an alkaline aqueous solution are presented. The key role of arylnitrenium cations, in the case of primary and secondary arylamines, and arylamine dications and immonium cations, in the case of tertiary arylamines, in the formation of corresponding o-aminoaryl sulfates, as prevalent soluble products, and oligoarylamines, as prevalent insoluble products, is proposed on the basis of the AM1 and RM1 computational study of the Boyland-Sims oxidation of aniline, ring-substituted (2-methylaniline, 3-methylaniline, 4-methylaniline, 2,6-dimethylaniline, anthranilic acid, 4-aminobenzoic acid, sulfanilic acid, sulfanilamide, 4-phenylaniline, 4-bromoaniline, 3-chloroaniline, and 2-nitroaniline) and N-substituted anilines (N-methylaniline, diphenylamine, and N,N-dimethylaniline). Arylnitrenium cations and sulfate anions (SO(4)(2-)) are generated by rate-determining two-electron oxidation of primary and secondary arylamines with S(2)O(8)(2-), while arylamine dications/immonium cations and SO(4)(2-) are initially formed by two-electron oxidation of tertiary arylamines with S(2)O(8)(2-). The subsequent regioselectivity-determining reaction of arylnitrenium cations/arylamine dications/immonium cations and SO(4)(2-), within the solvent cage, is computationally found to lead to the prevalent formation of o-aminoaryl sulfates. The formation of insoluble precipitates during the Boyland-Sims oxidation of arylamines was also computationally studied.

Stainless Steel As a Catalyst for the Total Deoxygenation of Glycerol and Levulinic Acid in Aqueous Acidic Medium

Exposing 316 Stainless Steel pressure reactor bodies to an aqueous Bronstedt acidic solution (trifluoromethane sulfonic acid) at elevated temperatures (100−250 °C) under reducing atmosphere (hydrogen gas at 800 psi) leads to the formation of insoluble inorganic precipitates, identified as mixed chromium oxides by scanning electron microscopy X-ray fluorescence (SEM-XRF). A catalytically active metal surface is generated, that is, under these conditions the <100 Ǻ thick chromium oxide layer that normally passivates 316 Stainless Steel (316SS) against corrosion is etched away, and the reactor body itself becomes an active hydrogenation catalyst. The effect is specific to aqueous acidic medium and therefore water-soluble substrates as encountered in biomass conversion, for example, sugar alcohols and levulinic acid, which can be deoxygenated to the corresponding alkanes and alkenes using only a Bronstedt acid and the reactor body as the catalyst. Control experiments in several different 316SS reactors built ...

Enhanced removal of triphosphate by MgCaFe-Cl-LDH: Synergism of precipitation with intercalation and surface uptake

Triphosphate (TPP) is an important form of phosphate pollutants while its removal investigation has been just started now. This research examined the removal of triphosphate using Mg 2− x Ca x FeCl-LDH ( x = 0–2) as absorbents. We found that the removal of triphosphate over Mg 2FeCl-LDH mainly underwent the surface adsorption and the near-edge intercalation, with the practical removal amount (9–11 mg(P)/g) corresponding to 10–15% of the theoretical one. In contrast, Ca 2FeCl-LDH removed a higher amount of triphosphate (56.4 mg(P)/g). The comprehensive analysis of the triphosphate-uptake products with XRD/XPS/FTIR reveals that Ca 2FeCl-LDH dissolves first and then released Ca 2+ ions react with triphosphate (TPP) to form insoluble Ca-TPP precipitate. Combination of these two different removal mechanisms enables Mg 0.5Ca 1.5FeCl-LDH to take up 84.2 mg(P)/g from aqueous solution under similar conditions.

Preparation of water soluble graphene using polyethylene glycol: Comparison of covalent approach and noncovalent approach

Formulation of stable aqueous graphene solution is attempted either through esterification of GO with PEG and subsequent reduction in covalent approach or in situ chemical reduction of aqueous GO solution in the presence of NH 2–PEG–NH 2 in noncovalent approach. While covalent approach produces insoluble graphite-like precipitation, noncovalent approach produces practically homogeneous reduced graphene solution for several months without any precipitate. Noncovalent interaction between NH 2–PEG–NH 2 and graphene is crucial for formulating fully reduced graphene solution with high stability. Various wet process such as spin-coating, ink-jet printing, and spraying can be directly utilized to formulate graphene-based electronic devices such as transparent electrode or anti-static coating without any additional reduction process which is necessary when insulating GO solution is used instead. Non-conducting NH 2–PEG–NH 2 can be simply removed from conducting graphene film by simple filtration and washing process to formulate pure graphene film because interaction between graphene and NH 2–PEG–NH 2 is not covalent. The initial surface resistance of graphene thin film with NH 2–PEG–NH 2 is in the range of 10 6 Ω/□ but it decreases to 10 4 Ω/□ after removing NH 2–PEG–NH 2.

Cell culture medium as an alternative to conventional simulated body fluid

Simulated body fluid (SBF) has been widely used for bioactivity assessment of biomaterials. Many different recipes have been developed, but there is still room for improvement. We have suggested the use of cell culture medium to overcome the drawbacks of conventional SBF. Compared with conventional SBF, cell culture medium is easy to prepare. The normal practices in cell culturing, such as filtering, can eliminate insoluble precipitates in the medium and incubation at 37 °C in an atmosphere with 5% CO 2 also better simulates the in vivo environment. After 4 days immersion in carbonate buffered Dulbecco’s modified Eagle’s medium (DMEM), precipitates were found to have formed on the surfaces of hydroxyapatite (HA), α-tricalcium phosphate (α-TCP) and β-tricalcium phosphate (β-TCP). In order to further verify the use of cell culture medium for SBF studies, we carried out computational thermodynamic and kinetic analyses of the precipitation reaction to reveal the effect of pH and ion concentrations on the driving force and nucleation rate of precipitation of different calcium phosphates (CaP). In general, a slight increase in pH of the cell culture medium from physiological pH (pH 7.4) would favor CaP precipitation thermodynamically and increase the rate, as in the case of r-SBF reported previously. [Ca] and [P] have more impact on precipitation compared with other ions, but the effect is consistent among different materials, indicating that other cell culture media with slightly different compositions may also be used. This study also shows that matching the buffer with the environment is required and fetal bovine serum (FBS) slows down surface CaP precipitation on HA.

Isolation and characterization of a chromium-resistant bacterium Serratia sp. Cr-10 from a chromate-contaminated site

A novel bacterium, Cr-10, was isolated from a chromium-contaminated site and capable of removing toxic chromium species from solution by reducing hexavalent chromium to an insoluble precipitate. Sequence analysis of 16S rRNA gene of strain Cr-10 showed that it was most closely related to Serratia rubidaea JCM 1240(T) (97.68%). Physiological and chemotaxonomic data also supported that strain Cr-10 was identified as Serratia sp., a genus which was never specially reported chromate-resistant before. Serratia sp., Cr-10 was tolerant to a concentration of 1,500 mg Cr(VI) L(-1), which was the highest level reported until now. The optimum pH and temperature for reduction of Cr(VI) by Serratia sp. Cr-10 were found to be 7.0 and 37 °C, respectively. The Cr(VI) reduction was significantly influenced by additional carbon sources, and among them fructose and lactose offered maximum reduction, with a rate of 0.28 and 0.25 mg Cr(VI) L(-1) h(-1), respectively. The cell-free extracts and filtrate of the culture were able to reduce Cr(VI) while concentration of total chromium remained stable in the process, indicating that the enzyme-catalyzed mechanism was applied in Cr(VI) reduction by the isolate. Additionally, it was found that there was hardly any chromium on the cell surface of the strain, further supporting that reduction, rather than bioadsorption, plays a major role in the Cr(VI) removal.

Compatibilidad física del bicarbonato sódico con fármacos de uso frecuente en la unidad de cuidados intensivos

Introduction Acid-base disorders are associated with many diseases of the critically ill patient. Early treatment with sodium bicarbonate of these metabolic disorders is required for their normalization. This is an alkaline electrolyte solution administered by continuous or intermittent infusion. Its incompatibility due to its alkaline pH has been described, as it produces insoluble carbonate precipitation and causes carbon dioxide gas when mixed with acidic solutions. Material and method An in vitro experimental study was performed. Bicarbonate was mixed with 13 drugs simulating Y-site administration. We combined 5 ml bicarbonate with 5 ml of every drug, at highest daily concentration used. The samples were visually examined to detect color changes, cloudiness, precipitation or gas formation, pH measurement and spectrophotometric analysis at 450 nm and 620 nm. The samples were evaluated at 0, 15, 30, 60 and 120 minutes. The compatibility criteria were absence of visual changes, pH changes < 0.5 and variability of absorbance <0.01. Results We studied each drug individually and mixed with bicarbonate with 27 samples, and 135 measurements were performed. The incompatibilities did not always produce visual changes. Knowing the pH of drugs does not guarantee the compatibility of the mixture. Nitroglycerin with pH 4 is compatible with bicarbonate. Thiopental with pH 11 makes precipitation. Higher absorbances showed color changes, cloudiness and precipitation. Conclusions Bicarbonate is physically compatible with esmolol, furosemide, heparin, insulin, morphine, nimodipine, nitroglycerin and urapidil and incompatible with amiodarone, cisatracurium, haloperidol, midazolam and thiopental.