38 research outputs found
THE INFLUENCE OF NANOCELLULOSE AND SILICON DIOXIDE ON THE MECHANICAL PROPERTIES OF THE CELL WALL WITH RELATION TO THE BOND INTERFACE BETWEEN WOOD AND UREA-FORMALDEHYDE RESIN
Urea-formaldehyde (UF) resin is used as an adhesive in the most wood-based composite plants in China. The quality of such composites is strongly affected by the mechanical properties of the cell wall in relation to the interface between UF resin and wood. This research investigates the mechanical properties of the cell wall in the bond interface of wood and UF resin with nanocellulose and silicon dioxide, and compares the mechanical properties of wood-adhesive interface cell walls to their gluing strength. The hardness and reduced modulus of the cell wall were investigated by means of nanoindentation. The test results show that there was a close relationship between the mechanical properties of the cell walls at the wood-adhesive interface and the percentage of nanocellulose or SiO2 in the UF. The shear strength of UF resin with nanofibrillated cellulose (NFC) or nano-SiO2 in bonded wood also gradually increased when the content of these two kinds of nanomaterials was increased from 0% to 2%
Incorporation size of lymph node metastasis focus and pre-ablation stimulated Tg could more effectively predict clinical outcomes in differentiated thyroid cancer patients without distant metastases
BackgroundThe size of lymph node metastasis (LNM) and pre-ablation stimulated Tg (ps-Tg) were key predictors of clinical prognosis in differentiated thyroid cancer (DTC) patients, however, very few studies combine the above two as predictors of clinical prognosis of DTC patients.MethodsPersistent/recurrent disease and clinicopathologic factors were analyzed in 543 DTC patients without distant metastases who underwent LN dissection, near-total/total thyroidectomy, and radioiodine ablation.ResultsIn the multivariate analysis, size of LNM, ps-Tg, and the activity of 131I significantly correlated with long-term remission. The optimal cutoff size of LNM 0.4 cm-1.4 cm (intermediate-risk patients) and >1.4cm (high-risk patients) increased the recurrence risk (hazard ratio [95% CI], 4.674 [2.881-7.583] and 13.653 [8.135–22.913], respectively). Integration of ps-Tg into the reclassification risk stratification showed that ps-Tg ≤ 10.1 ng/mL was relevant to a greatly heightened possibility of long-term remission (92.2%–95.4% in low-risk patients, 67.3%–87.0% in intermediate-risk patients, and 32.3%–57.7% in high-risk patients).ConclusionThe cutoff of 0.4 cm and 1.4 cm for a definition of size of LNM in DTC patients without distant metastases can reclassify risk assessment, and incorporating ps-Tg could more effectively predict clinical outcomes and modify the postoperative management plan
Changes of the Microbiota Composition on the Surface of Pig Carcasses during Chilling and Its Associations with Alterations in Chiller’s Temperature and Air Humidity
In this study, we investigated changes of microbiota composition on the surface of pig carcasses during chilling and their associations with temporal and spatial changes of wind speed, air temperature, and air humidity. The composition of microbiota on a carcass surface varied greatly with sampling sites; in particular, the surfaces of forelegs and neck had higher load of microorganisms and different microbiota composition compared to in the air and other carcass parts. However, such a difference in the microbiota composition decreased as chilling time extended. The positive detection ratios of microbial genes resistant to sulfonamides, quinolones, tetracyclines, and β-lactams were found different greatly with chilling time and sampling sites. The β-lactam and tetracycline resistant genes were observed in higher ratios in airborne microorganisms in the chiller, while the sulfa and tetracycline resistant genes had higher ratios in the microbiota on pig carcasses. Actual measurements and dynamic simulation showed that air temperature and humidity varied greatly among different places in a chiller within the first 8 h of chilling, with higher values close to the door, but the differences became smaller afterwards. The micro-environmental differences and changes in the chiller may cause the different composition of microbiota on pig carcasses
A universal, rapid method for clean transfer of nanostructures onto various substrates
Transfer and integration of nanostructures onto target substrates is the prerequisite for their fundamental studies and practical applications. Conventional transfer techniques that involve stamping, lift-off, and/or striping suffer from the process-specific drawbacks, such as the requirement for chemical etchant or high-temperature annealing and the introduction of surface discontinuities and/or contaminations that can greatly hinder the properties and functions of the transferred materials. Herein, we report a universal and rapid transfer method implementable at mild conditions. Nanostructures with various dimensionalities (i.e., nanoparticles, nanowires, and nanosheets) and surface properties (i.e., hydrophilic and hydrophobic) can be easily transferred to diverse substrates including hydrophilic, hydrophobic, and flexible surfaces with good fidelity. Importantly, our method ensures the rapid and clean transfer of two-dimensional materials and allows for the facile fabrication of vertical heterostructures with various compositions used for electronic devices. We believe that our method can facilitate the development of nanoelectronics by accelerating the clean transfer and integration of low-dimensional materials into multidimensional structures
Cobalt ferrite/cellulose membrane inserted catalytic syringe filter for facile in-situ filtration/degradation of emerging organic pollutants in water via activating peroxymonosulfate
In this study, a novel membrane was prepared from CoFe2O4 deposited commercial cellulose filter paper, and employed in the design of a catalytic syringe filter. The filter was used for the removal of various synthetic organic chemicals (SOCs) including rhodamine B, dimethyl phthalate, bisphenol A, ibuprofen, norfloxacin, 4-chlorophenol and diclofenac in water through in-situ activating peroxymonosulfate, which simulated an actual syringe-driven filtration process. The impact of SOC concentration, injection speed, series-connected filter number on the in-situ filtration/degradation performance of the filter were systematically investigated. The results demonstrated that the prepared filter had excellent catalytic capability towards all mentioned SOCs. Specifically, three series-connected filters could completely degraded SOCs even when the concentration of each SOC was higher than 0.1 mM. ESR and quenching tests indicated that the ·OH and SO4−· were main radical species dominating the SOC degradations. Meanwhile, high-valent metal-oxo species were also generated which participated in the SOC degradations. Furthermore, the filter had promising longtime use stability which maintained its effectiveness for 2 h of uninterrupted water flow. This study provides a facile and practical means to introduce advanced oxidation techniques for organic pollutant removals in actual wastewater through syringe-driven in-situ membrane filtration/degradation process
Effect of natural plant extracts on the quality of meat products: a meta-analysis
Natural plant extracts (NPE) from some organs of plants are rich in bioactive substances. They have special nutritional characteristics with strong antioxidant and antimicrobial activities. The potential of NPEs to maintain and improve the quality of meat products has attracted attention due to concerns about the safety hazards of synthetic food additives. This paper extensively reviewed the application of NPE in meat processing, and systematically analyzed the comprehensive effects of different NPE using meta-analysis. Fourty-eight articles from 23 countries were studied with standard mean deviation (SMD) using random effect model, and 28 indexes were isolated. Results showed that NPE can reduce the pH value of meat products, improve antioxidant capacity, reduce the degree of oxidation and inhibit microbial growth. In addition, it was found that NPE had a significant impact on the quality of meat products. This meta-analysis provides quantitative evidence to explain how NPE affects meat quality, and helps to better understand the role of NPE in meat processing
Layer thinning and etching of mechanically exfoliated MoS2 nanosheets by thermal annealing in air
A simple thermal annealing method for layer thinning and etching of mechanically exfoliated MoS2 nanosheets in air is reported. Using this method, single-layer (1L) MoS2 nanosheets are achieved after the thinning of MoS2 nanosheets from double-layer (2L) to quadri-layer (4L) at 330 °C. The as-prepared 1L MoS2 nanosheet shows comparable optical and electrical properties with the mechanically exfoliated, pristine one. In addition, for the first time, the MoS2 mesh with high-density of triangular pits is also fabricated at 330 °C, which might arise from the anisotropic etching of the active MoS2 edge sites. As a result of thermal annealing in air, the thinning of MoS2 nanosheet is possible due to its oxidation to form MoO3. Importantly, the MoO3 fragments on the top of thinned MoS2 layer induces the hole injection, resulting in the p-type channel in fabricated field-effect transistors
Microbiota changes on the surface of pig carcasses during refrigerated transportation and marketing
We investigated changes in the microbiota composition on the surface of pig carcasses during refrigerated transportation of different distances (200, 300, 400, 500 km) and further transferring to the market place. Microbial samples were obtained by sterile swabs at the starting point, the end points of transportation and the market points. Core temperature of pig carcasses, temperature and air humidity in refrigerated vehicles were also tracked. The air temperature and humidity in the refrigerated vehicles remained relatively constant during transportation. However, the air temperature and carcass temperature at the end points of transportation were the highest for the 500 km group and the lowest for the 400 km group (P < 0.05), while the air humidity was the highest for the 200 km group and the lowest for the 400 km group (P < 0.05). Microbial colony counts showed a slight increase during transportation and differed among five sampling points on the surface of pork carcasses with the highest for the outside of the shoulder and the lowest for the inside of the belly (P < 0.05). Microbiota composition changed greatly and Acinetobacter, Pseudomonas, Psychrobacter, Chryseobacterium, Staphylococcus, Brochothrix, Morexella, and Flavobacterium were the predominant genera. Pseudomonas was the most predominant during transportation
Two-dimensional CuSe nanosheets with microscale lateral size : synthesis and template-assisted phase transformation
Semiconducting nanosheets with microscale lateral size are attractive building blocks for the fabrication of electronic and optoelectronic devices. The phase-controlled chemical synthesis of semiconducting nanosheets is of particular interest, because their intriguing properties are not only related to their size and shape, but also phase-dependent. Herein, a facile method for the synthesis of phase-pure, microsized, two-dimensional (2D) CuSe nanosheets with an average thickness of approximately 5 nm is demonstrated. These hexagonal-phased CuSe nanosheets were transformed into cubic-phased Cu2−xSe nanosheets with the same morphology simply by treatment with heat in the presence of CuI cations. The phase transformation, proposed to be a template-assisted process, can be extended to other systems, such as CuS and Cu1.97S nanoplates. Our study offers a new method for the phase-controlled preparation of 2D nanomaterials, which are not readily accessible by conventional wet-chemical methods