Preparation of Dicalcium Phosphate Anhydrous (Monetite) Biological Coating on Titanium by Spray-Drying Method

Titanium and its alloys have been widely used in the manufacture of endosseous implants due to excellent biocompatibility, low elastic modulus, and good chemical stability. However, the titanium based metals are essentially bioinert materials. In order to improve their bioactivity, biological coatings are usually applied. Recent studies found that, compared with hydroxyapatite coating, dicalcium phosphate anhydrous (DCPA, Monetite) coating maybe more bioactive due to higher solubility and release of Ca and P ions. In this work, DCPA coating was prepared through a novel and simple method. Briefly, high concentration DCPA solution was sprayed onto superhydrophilic titanium and the specimens were dried fast in an air-circulating oven. After repeating the process over 100 times, a compact coating was fabricated. The microstructure, chemical composition, wettability, and in vitro bioactivity of the coating were analyzed and evaluated. Results showed that the coating fully covered the substrate and consisted of a large number of uniformly sized DCPA granules that packed together closely. The coating showed good wettability and could keep the property for a long time. After immersion in simulated body fluid for 2 weeks, a large amount of bone-like apatite with low crystallinity was induced implying a good bioactivity

An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation.

To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar) and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0%) compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture) after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations

Experimental Study of Both-Sides Cylindrical Roller Machining Based on Ceramic Plate

In order to improve the accuracy and batch consistency of cylindrical roller machining, in this paper, a both-sides cylindrical roller machining method based on hard ceramic plate is proposed. Traditional cast iron and stainless-steel polishing plate were replaced by ceramic materials with high hardness and good wear resistance. After processing by centerless grinding, the cylindrical roller is processed by both-sides lapping and polishing using Al2O3 ceramic plates. The roundness, diameter and surface quality of the roller and the wear of the ceramic plate before and after machining were compared and analyzed in order to evaluate the feasibility and effectiveness of this method. After grinding for 1 h and polishing for 8 h, the average roundness of the cylindrical rollers decreased from the initial 2.3 μm to 0.32 μm, while the roundness of each roller tended to be the same. At the same time, the batch diameter deviation of cylindrical rollers was reduced from 3 μm to 1 μm, and the batch consistency was satisfactory. The machining marks produced by centerless grinding on the roller surface were completely removed, and the surface quality was significantly improved. The surface roughness after polishing reached Ra 16 nm. The upper and lower ceramic plate had certain wear, but the amount was small, having little impact on the machining results. The shape accuracy and batch consistency of the rollers after machining were satisfactory. The ceramic plate had high hardness, good wear resistance and small wear in the machining process. Additionally, it could maintain extremely high flatness for a long time. Using hard ceramic plates to process cylindrical rollers, high precision and high consistency cylindrical rollers can be obtained after machining

Biogas slurry application alters soil properties, reshapes the soil microbial community, and alleviates root rot of Panax notoginseng

Background Panax notoginseng is an important herbal medicine in China, where this crop is cultivated by replanting of seedlings. Root rot disease threatens the sustainability of P. notoginseng cultivation. Water flooding (WF) is widely used to control numerous soilborne diseases, and biogas slurry shows positive effects on the soil physiochemical properties and microbial community structure and has the potential to suppress soilborne pathogens. Hence, biogas slurry flooding (BSF) may be an effective approach for alleviating root rot disease of P. notoginseng; however, the underlying mechanism needs to be elucidated. Methods In this study, we conducted a microcosm experiment to determine if BSF can reduce the abundance of pathogens in soil and, alleviate root rot of P. notoginseng. Microcosms, containing soil collected from a patch of P. notoginseng showing symptoms of root rot disease, were subjected to WF or BSF at two concentrations for two durations (15 and 30 days), after which the changes in their physicochemical properties were investigated. Culturable microorganisms and the root rot ratio were also estimated. We next compared changes in the microbial community structure of soils under BSF with changes in WF and untreated soils through high-throughput sequencing of bacterial 16S rRNA (16S) and fungal internal transcribed spacer (ITS) genes amplicon. Results WF treatment did not obviously change the soil microbiota. In contrast, BSF treatment significantly altered the physicochemical properties and reshaped the bacterial and fungal communities, reduced the relative abundance of potential fungal pathogens (Fusarium, Cylindrocarpon, Alternaria, and Phoma), and suppressed culturable fungi and Fusarium. The changes in the microbial community structure corresponded to decreased root rot ratios. The mechanisms of fungal pathogen suppression by BSF involved several factors, including inducing anaerobic/conductive conditions, altering the soil physicochemical properties, enriching the anaerobic and culturable bacteria, and increasing the phylogenetic relatedness of the bacterial community. Conclusions BSF application can reshape the soil microbial community, reduce the abundance of potential pathogens, and alleviate root rot in P. notoginseng. Thus, it is a promising practice for controlling root rot disease in P. notoginseng

Data from: Optimization and kinetic study of methyl laurate synthesis using ionic liquid [Hnmp]HSO4 as a catalyst

Methyl laurate was synthesized from lauric acid (LA) and methanol via an esterification reaction using ionic liquids (ILs) as catalysts. The efficiencies of three different catalysts, 1-methylimidazole hydrogen sulfate ([Hmim]HSO4), 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSO4) and H2SO4, were compared. The effect of the methanol/LA molar ratio, reaction temperature, reaction time and catalyst dosage on the esterification rate of LA was investigated by single-factor experiments. Based on the single-factor experiments, the esterification of LA and methanol was optimized using response surface methodology. The results showed that the most effective catalyst was the IL [Hnmp]HSO4. The optimal conditions were as follows: [Hnmp]HSO4 dosage of 5.23%, methanol/LA molar ratio of 7.68 : 1, reaction time of 2.27 h and reaction temperature of 70°C. Under these conditions, the LA conversion of the esterification reached 98.58%. A kinetic study indicated that the esterification was a second-order reaction with an activation energy and a frequency factor of 68.45 kJ mol−1 and 1.9189 × 109 min−1, respectively. The catalytic activity of [Hnmp]HSO4 remained high after five cycles

A comprehensive review of the process on hexachlorobenzene degradation

This paper describes the chemical, physical property of the pollution source along with its perniciousness. In addition, with the recent treatment or degradation of the hexachlorobenzene (HCB), it talks about the research developments on the HCB. Of the many options available for treatment of municipal and industrial HCB pollution, the anaerobic biological treatment process is unique because of its potential for producing usable energy. It focuses on the biodegradation pathway which is intent to finish the steps of dechlorination. Moreover, the future study on the HCB degradation is prospected in this paper from the author’s angle