Thermogravimetry (TG), TG-MS, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM)-energy dispersive spectrometer(EDS) were adopted to investigate the pyrolysis characteristics of calamina. According to the findings of the qualitative and quantitative studies on the changes in the content of relevant elements, the whole shape, the functional groups, and the volatile components of calamina before and after being pyrolyzed, the 200-360, 580-750 degrees C were two sensitive temperature ranges related to the changes in effective component during calamina processing. Thermal weight loss was observed for ZnCO3, Zn(OH)2 and ZnCO3-2Zn(OH)2-H2O under 200-360 degrees C and for CaCO3 under 580-750 degrees C. The results of studies on chemical reaction kinetics showed good linear relations. This experiment integrated relevant methods and theories of physical chemistry and science of traditional Chinese medicine processing, and interpretes calamina processing techniques and mechanism, in order to provide a good example for modem studies on other traditional Chinese medicine processing.
Drug Combinations ; Drug Compounding ; methods ; Ferric Compounds ; chemistry ; Kinetics ; Temperature ; Zinc Oxide ; chemistry

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity* ; Sewage/chemistry* ; Zinc Oxide/chemistry* ; Waste Disposal, Fluid ; Nanoparticles/chemistry* ; Metal Nanoparticles/chemistry* ; Nitrogen/metabolism* ; Water Purification

OBJECTIVEThe aim of this study is to analyze the processing mechanism of calamine.

METHODXRD, TEM and IR were adopted to analyze the structures and the components of original and calcined calamine. Their antibacterial activities were also determined.

RESULTThe results indicated that zinc carbonate in original calamine was decomposed into zinc oxide after processing at 700 degrees C for 1 hour using original calamine of 40 mesh, and the particle size was smaller than before processing. All of ZnO, ZnCO3 and Zn5 (CO3) 2 (OH) 6 had antibacterial activitives.

CONCLUSIONOriginal calamine is deposed to ZnO after being calcined for 1 h at 700 degrees C and wet milling. The content of ZnO and antibacterial activity of calcined calamine are better than those of original calamine, moreover, the particle size diminishes and become dimensional uniformity, and the contents of dissolved impurities is decreased. The antibacterial activitives of original and calcined calamine are decided by zinc.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacteria ; drug effects ; Drug Combinations ; Ferric Compounds ; chemistry ; pharmacology ; Particle Size ; Zinc Oxide ; chemistry ; pharmacology

OBJECTIVETo study processing method and mechanism of Calamine.

METHODThermogravimetry analysis method and nano-technology were adopted to analyze and synthesize the components in Calamine, Tetracycline was took as the comparison drug to determine the antibacterial activity of Calamine and its components.

RESULTA part of zinc carbonate in Calamine was decomposed into zinc oxide when processing, and the particle size was smaller than before. The antibacterial activity of Calamine is decided by the content and particle size of zinc oxide, and has nothing with zinc carbonate. The more content and the smaller particle size of zinc oxide, the more powerful antibacterial activity of Calamine.

CONCLUSIONThe content and the particle size of zinc oxide can be the important targets in the processing of Calamine.

Anti-Bacterial Agents ; pharmacology ; Carbonates ; chemistry ; pharmacology ; Drug Combinations ; Escherichia coli ; drug effects ; Ferric Compounds ; chemistry ; pharmacology ; Materia Medica ; chemistry ; pharmacology ; Nanostructures ; Nanotechnology ; Particle Size ; Pseudomonas aeruginosa ; drug effects ; Salmonella ; drug effects ; Staphylococcus aureus ; drug effects ; Technology, Pharmaceutical ; methods ; Tetracycline ; pharmacology ; Thermogravimetry ; Zinc Compounds ; chemistry ; pharmacology ; Zinc Oxide ; analysis ; chemistry ; pharmacology

OBJECTIVEThis study aims to investigate and compare the toxic effects of four types of metal oxide (ZnO, TiO(2), SiO(2,) and Al(2)O(3)) nanoparticles with similar primary size (∼20 nm) on human fetal lung fibroblasts (HFL1) in vitro.

METHODSThe HFL1 cells were exposed to the nanoparticles, and toxic effects were analyzed by using MTT assay, cellular morphology observation and Hoechst 33 258 staining.

RESULTSThe results show that the four types of metal oxide nanoparticles lead to cellular mitochondrial dysfunction, morphological modifications and apoptosis at the concentration range of 0.25-1.50 mg/mL and the toxic effects are obviously displayed in dose-dependent manner. ZnO is the most toxic nanomaterials followed by TiO(2), SiO(2), and Al(2)O(3) nanoparticles in a descending order.

CONCLUSIONThe results highlight the differential cytotoxicity associated with exposure to ZnO, TiO(2), SiO(2), and Al(2)O(3) nanoparticles, and suggest an extreme attention to safety utilization of these nanomaterials.

Aluminum Oxide ; chemistry ; toxicity ; Apoptosis ; drug effects ; Cell Culture Techniques ; Cell Line ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Fibroblasts ; drug effects ; pathology ; Humans ; Lung ; drug effects ; embryology ; pathology ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Microscopy, Phase-Contrast ; Nanoparticles ; chemistry ; toxicity ; Silicon Dioxide ; chemistry ; toxicity ; Surface Properties ; Titanium ; chemistry ; toxicity ; Zinc Oxide ; toxicity

Although formaldehyde is well known to cause type 4 hypersensitivity, immunoglobulin E (IgE)-mediated hypersensitivity to formaldehyde is rare. Here, we report a case of recurrent generalized urticaria after endodontic treatment using a para-formaldehyde (PFA)-containing root canal sealant and present a review of previous studies describing cases of immediate hypersensitivity reactions to formaldehyde. A 50-year-old man visited our allergy clinic for recurrent generalized urticaria several hours after endodontic treatment. Prick tests to latex, lidocaine, and formaldehyde showed negative reactions. However, swelling and redness at the prick site continued for several days. The level of formaldehyde-specific IgE was high (class 4). Thus, the patient was deemed to have experienced an IgE-mediated hypersensitivity reaction caused by the PFA used in the root canal disinfectant. Accordingly, we suggest that physicians should pay attention to type I hypersensitivity reactions to root canal disinfectants, even if the symptoms occur several hours after exposure.
Disinfectants/*adverse effects ; Formaldehyde/*adverse effects ; Humans ; Hypersensitivity, Immediate/*chemically induced ; Immunoglobulin E/*immunology ; Male ; Middle Aged ; Recurrence ; Skin Tests ; Time Factors ; Urticaria/*chemically induced/diagnosis ; Zinc Oxide-Eugenol Cement/*chemistry

Nanoporous ZnO was used as a carrier to prepare drug solid dispersion, the mechanism of which to improve the drug dissolution was also studied. Nanoporous ZnO, obtained through chemical deposition method, was used as a carrier to prepare indomethacin and cilostazol solid dispersions by melt-quenching method, separately. The results of scanning electron microscope, surface area analyzer, fourier transform infra-red spectroscopy, differential scanning calorimeter and X-ray diffraction showed that drugs were implanted into nanopores of ZnO by physical adsorption effect and highly dispersed into nanopores of ZnO in amorphous form, moreover, these nanopores strongly inhibited amorphous recrystallization in the condition of 45 degrees C and 75% RH. In addition, the results of the dissolution tested in vitro exhibited that the accumulated dissolutions of indomethacin and cilostazol solid dispersions achieved about 90% within 5 min and approximately 80% within 30 min. It was indicated in this study that the mechanism of drug dissolution improvement was associated with the effects of nanoporous ZnO carrier on increasing drug dispersion, controlling drug in nanopores as amorphous form and inhibiting amorphous recrystallization.
Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; chemistry ; Calorimetry, Differential Scanning ; Drug Carriers ; Indomethacin ; administration & dosage ; chemistry ; Microscopy, Electron, Scanning ; Nanostructures ; Phosphodiesterase 3 Inhibitors ; administration & dosage ; chemistry ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Tetrazoles ; administration & dosage ; chemistry ; X-Ray Diffraction ; Zinc Oxide ; chemistry

OBJECTIVETo observe the influence of different bonding process and three different root canal sealing materials on microstructure of root canal dentin bonding interface after fiber post and resin bonding, so as to improve clinical operation steps and to optimize fiber post resin bonding effect.

METHODSFifteen human single mandibular first premolars were selected. Three were bonded with fiber posts through Relyx Unicem conventional bonding steps after filled with root canal sealing materials of zinc oxide eugenol paste (Group A), and another three were bonded through the same steps after filled with sealing materials of Vitapex (Group B). The other nine were filled with sealing materials of AH Plus, randomly divided into three groups and bonded through different steps as follows: conventional bonding steps only (Group C), etching with 35% phosphoric acid before conventional bonding steps (Group D), and etching and coating with Singlebond 2 adhesive before conventional bonding steps (Group E). After immersed in saline solution for one week, all the roots were cut into three sections of 3 mm in thickness with emery chip and numbered as crown section, middle section and tip section respectively. The samples were observed the resin protrusion in mixed layer of dentin interface and dentinal tubules by scanning electron microscopy.

RESULTSWe observed the resin protrusion in microstructures of the roots bonded through Relyx Unicem after filled with three different root canal sealing materials (Group A, B, C, E): most obvious in the root crown sections, middle in the root middle sections and least in the root tip sections. Differences were observed in roots filled with different sealing materials: little resin protrusion were observed in crown sections only in Group A and B, but large number of resin protrusion were found in crown and middle sections in Group C-E. Compared with Group C, no more resin protrusion were found in Group D. More and elongated resin protrusions were found in Group E.

CONCLUSIONSWe recommend using AH Plus as root canal sealing materials for residual crown and root needed to strengthen by fiber post. It is no need to etch before Relyx Unicem conventional bonding steps. However, coating Singlebond 2 adhesive after acid etching has the potential to increase fiber post cementation.

Acid Etching, Dental ; methods ; Calcium Hydroxide ; Dental Bonding ; methods ; Dental Pulp Cavity ; ultrastructure ; Dentin ; ultrastructure ; Dentin-Bonding Agents ; chemistry ; Epoxy Resins ; Humans ; Mandible ; ultrastructure ; Microscopy, Electron, Scanning ; Molar ; ultrastructure ; Post and Core Technique ; Resin Cements ; Root Canal Filling Materials ; chemistry ; Silicones ; Tooth Root ; ultrastructure ; Zinc Oxide-Eugenol Cement

OBJECTIVEToxic metal ions have been implicated in the generation of reactive oxygen species (ROS) and nitric oxide (NO). Metallothionines (MT) and plant flavonoids have been reported in the intervention against oxidative damage. We investigated the effect of zinc induced MT and green tea polyphenol (GTP) in reducing the oxidative responses induced by nickel and platinum.

METHODSZinc (10 mg/kg b. wt, sc) was administered to rats twice at a gap of 24 hrs and GTP (10 mg/100 mL in drinking water) was fed ad libitum for 8 days. Nickel chloride (150 umol/kgb.wt, ip) and cisplatin (50 mumol/kg b.wt, sc) was administered to rats 24 h after Zn or GTP pre-treatment. Animals of all the groups were sacrificed 16 hrs after treatment and biochemical markers for toxicity were monitored.

RESULTSZinc or GTP pre-treatment caused significant protection against nickel or cisplatin enhanced mortality in rats, and reduction in lipid peroxidation and NO.

CONCLUSIONIt is proposed that inhibition of ROS and NO by GTP and zinc may prove useful as a selective pharmacological agent in the amelioration of metal toxicity.

Animals ; Antioxidants ; pharmacology ; Biomarkers ; Cisplatin ; administration & dosage ; toxicity ; Flavonoids ; administration & dosage ; pharmacology ; Free Radical Scavengers ; pharmacology ; Lipid Peroxidation ; drug effects ; Metallothionein ; metabolism ; Mortality ; Nickel ; administration & dosage ; toxicity ; Nitric Oxide ; metabolism ; Phenols ; administration & dosage ; pharmacology ; Polyphenols ; Rats ; Tea ; chemistry ; Time Factors ; Zinc ; administration & dosage ; pharmacology