Search

This study designed and synthesized a new drug-loading nanomaterial, the three-armed starshaped polymer compound (TaSPC), and loaded the broad-spectrum fungicide fluazinam to prepare TaSPC/fluazinam nanocarrier particles. The principle and drug-loading performance of TaSPC loading fluazinam were investigated by molecular docking simulation and ultraviolet spectrophotometry. The appearance and particle size changes before and after loading fluazinam onto TaSPC were compared and analyzed by transmission electron microscopy and scanning electron microscopy. The physicochemical properties of TaSPC and TaSPC/fluazinam were characterized by Zeta potential analysis, contact angle measurement with strawberry leaves, and uptake test with Rhodamine 6G. The in vitro and in vivo inhibitory effects of TaSPC/fluazinam on four plant pathogenic fungi, the toxicity of TaSPC to human umbilical vein endothelial cells, and the toxicity of TaSPC and TaSPC/fluazinam to Apis mellifera ligustica Spin, were determined. The results indicated that TaSPC could spontaneously combine with fluazinam through hydrophobic interaction, with a pesticide loading rate (PLC) of 9%. The particle size of TaSPC/fluazinam was 17.86 nm, which was significantly reduced by 71.4% compared to the original fluazinam (62.46 nm). After loading with TaSPC, the contact angle of the TaSPC/fluazinam droplet on strawberry leaves decreased from 44.08° to 33.60°, a significant reduction of 23.78%. The inhibitory effect of TaSPC/fluazinam on plant pathogenic fungi was significantly enhanced compared to the original fluazinam. Among them, the inhibitory activity against Botrytis cinerea was the highest, with an inhibition rate of 75% at a dose of 0.2 mg/L, an increase of nearly 60% compared to the original fluazinam. Within a reasonable application range, TaSPC had low cytotoxicity, and both TaSPC and TaSPC/fluazinam had low toxicity to pollinating bees. The study demonstrated that TaSPC is a significant benchmark for the development of efficient and low-toxicity nanocarrier materials and the reduction of pesticide use. [ABSTRACT FROM AUTHOR]

BACKGROUND: We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction, and verified the stability and reliability of the model. However, whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE: To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view, histology and electron microscopy. METHODS: Thirty adult female small ear pigs in southern Yunnan province were selected. Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon (n=30 in the normal group), and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system (n=30 in the relaxation group). The autogenous right forelimb was used as the control group; the anterior cruciate ligament was exposed but not severed or surgically treated. At 12, 24, and 48 weeks after surgery, 10 animals were sacrificed, respectively. The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology. MAS score was used to evaluate the excellent and good rate of the ligament at each time point. Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization. Collagen fibers and nuclear morphology were observed, and nuclear morphology was scored. Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION: (1) The ligament healing shape of the relaxation group was better at various time points after surgery, and the excellent and good rate of MAS score was higher (P < 0.05). Moreover, the relaxation group could obtain higher ligament vascularization score (P < 0.05). (2) The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly, and the transverse fiber connections between collagen gradually increased and thickened, suggesting that the strength and shape degree of the grafts were gradually improved, but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery. (3) The diameter, distribution density, and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points, especially in the comparison of collagen fiber diameter between and within the relaxation group (P < 0.05). [ABSTRACT FROM AUTHOR]

PZS@ATP nano-composite flame retardant was successfully prepared by in-situ polymerization using natural nano-mineral attapulgite (ATP), hexachlorocyclotriphosphazene (HCCP) and 4,4'-dihydroxydiphenyl sulfone (BPS) as raw materials, and the composite flame retardant was applied to epoxy resin (EP). The structure of PZS@ATP nanocomposite flame retardant was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The mechanical properties and thermal stability of the composites were tested by electronic universal testing machine and thermogravimetric analyzer. The results show that the addition of PZS@ATP can effectively improve the mechanical properties of the composites. When the addition amount of PZS@ATP is 2%, the impact strength of the composite increases to 12.768 kJ/m², which is 162% higher than that of pure EP. When the addition amount of PZS@ATP is 3%, the impact strength and tensile strength of the composite increase to 6.379 kJ/m² and 63.31 MPa, respectively, which are 30.9% and 0.2% higher than those of pure EP. The addition of 3% PZS@ATP can improve the mechanical properties and thermal stability of pure EP. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: The number of patients with periodontitis increases year by year, and the use of traditional periodontal treatment cannot restore the periodontal soft and hard tissue. Therefore, it is necessary to prepare a drug sustained-release material to assist the treatment of periodontitis and restore the damaged soft and hard tissues of periodontitis. OBJECTIVE: To prepare bovine serum albumin microspheres composite hydrogel material, detect the dual sustained release effect on simvastatin, and further study the effect of the composite material on the adhesion and proliferation of osteoblasts. METHODS: (1) Bovine serum albumin microspheres loaded with simvastatin were prepared by solvent removal method. The morphology of microspheres was observed by transmission electron microscopy and scanning electron microscopy and the particle size of microspheres was measured. The encapsulation rate, drug loading rate and in vitro release of microspheres were detected by a microplate analyzer. (2) Simvastatin albumin microspheres were loaded into the prepared hydrogel, and in vitro drug release from hydrogels was detected using a microplate reader. The morphology of the composite material was observed by scanning electron microscopy. The hydrogel extract was used to culture MC3T3-E1 cells. The proliferation of osteoblasts was detected by CCK-8 assay. The alkaline phosphatase expression in osteoblasts was detected by alkaline phosphatase kit. RESULTS AND CONCLUSION: (1) Transmission electron microscopy showed that bovine serum albumin microspheres and blank microspheres loaded with simvastatin were smooth, spherical and dispersed, with no obvious aggregation. The particle size of bovine serum albumin microspheres was uniform, and 80% of the microspheres had a particle size between 0.2 μm and 0.8 μm. Scanning electron microscopy showed that the microspheres were smooth and spherical with good dispersion and uniform particle size distribution, ranging from 0.2 μm to 0.8 μm. (2) The encapsulation rate and drug loading rate of simvastatin microspheres were 68.9%-87.5% and 0.95%-1.21%, respectively. (3) Drug-loaded microspheres had the performance of gentle and sustained release of simvastatin. The release curve of simvastatin in the drug-loaded hydrogel is a fast release in the early stage and a slow sustained release process in the later stage, in which the drug-loaded hydrogel can release faster than the drug-loaded microspheres and reach the effective concentration of the drug. The slow release in the later stage maintains the concentration of the drug. (4) Scanning electron microscopy showed that the drug-loaded hydrogel had a porous striplike structure, which was suitable for the adhesion and growth of osteoblasts, and spherical drug-loaded microspheres could be seen on the surface of the hydrogel. (5) The drug-loaded hydrogel can promote the proliferation and alkaline phosphatase expression of MC3T3-E1 cells. (6) Simvastatin microspheres hydrogel composite had good biocompatibility and could promote the adhesion and proliferation of osteoblasts. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Many recent studies have found that zirconia co-doped with TiO2 and GeO2 exhibits excellent superplasticity. OBJECTIVE: To investigate the improvement of anti-cryogenic aging properties of zirconia materials stabilized by 3% yttrium oxide co-doped with TiO2 and GeO2. METHODS: The 3% yttrium oxide stabilized zirconia material samples co-doped with GeO2 and TiO2 were prepared by mechanical ball milling, drying, and pressure free sintering. Among them, the mole percentage of 3% yttrium oxide stabilized zirconia was 98%. The mole percentages of TiO2 powder (purity 99.8%) and GeO2 powder were 1.5% and 0.5%, respectively, which was recorded as the 1.5Ti-0.5Ge group. The mole percentages TiO2 powder (purity) 99.99%) and GeO2 powder were 1% and 1%, respectively, which was recorded as 1Ti-1Ge group. The mole percentages of TiO2 powder (purity 99.8%) and GeO2 powder were 0.5%, 1.5%, respectively, which was recorded as 0.5Ti- 1.5Ge group. The microstructure of all samples was investigated by scanning transmission electron microscopy and energy spectroscopy. After treatment in an autoclave, the conversion of all samples was measured by an X-ray diffractometer. RESULTS AND CONCLUSION: (1) Scanning transmission electron microscopy results showed that the composite powders of a 3% yttrium oxide stabilized zirconia material co-doped with GeO2 and TiO2 had uniform particle size and were distributed over a 50 nm; the particle shape was basically spherical and well dispersed, but there was a small amount of agglomeration. X-ray diffractometer exhibited that the Ge4+, Ti4+ stabilizers could inhibit the low-temperature aging effect of zirconia materials. With the increase of the doping amount of GeO2, the low-temperature aging resistance of zirconia could be improved. Energy spectrometer detection demonstrated that with the increase of dopant content, the degree of grain boundary segregation increased, but even if the doping amount of Ge4+ was small, the degree of grain boundary segregation could be comparable to that of Ti4+ with a large amount of doping. (2) The results suggest that the addition of GeO2 and TiO2 improved 3% yttrium oxide stabilized zirconia ceramics against low-temperature aging properties. GeO2 is superior to TiO2 in resisting low-temperature aging and can be used as the first choice. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two-dimensional (2D) material, such as 2D polymer (2DP) and 2D covalent organic framework (2D-COF), has arisen as promising materials because of their unique physicochemical properties and great potential in optoelectronics, sensing, catalysis, separation, and energy storage and conversion. The preparation of 2DP films with desirable structures is promising but remains a significant challenge. Recently, vigorous efforts have been devoted to synthesizing 2DP films through different methods, such as interfacial synthesis at gas-water or liquid-liquid. Herein, a fluorescent pyrene-based 2D polyimine (2D-PI) thin film was prepared via Schiff-base condensation between 4,4',4',4''-(pyrene-1,3,6,8-tetrayl)tetraaniline and 2,5-dihydroxyterephthalaldehyde with trifluoromethanesulfonic acid as a catalyst at room temperature by a surfactantmonolayer-assisted interfacial synthesis (SMAIS) approach. The morphology, structure, crystallinity, and fluorescence intensity of the film were characterized by scanning electron microscopy, atomic force microscopy, transmission electron microscopy, X-ray diffraction, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The results revealed that the film thickness was 70 nm, which could be controlled by changing the monomer concentration. The imine bond formation was confirmed by Fourier transform infrared spectroscopy and Raman spectroscopy. The film crystallinity depended on the diffusion rate of monomer and was significantly improved by adding trifluoromethanesulfonic acid and surfactant monolayer, which provided a confined 2D template for polymerization. In addition, the fluorescence strength of the film was enhanced by the existence of intramolecular hydrogen bonding in the framework structure. This study provided a unique idea for the preparation of 2DP films with solid luminescent properties, which may be potentially applied to detect water content in organic solvent. [ABSTRACT FROM AUTHOR]

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Materials Science & Engineering (1673-2812) is the property of Journal of Materials Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hydroxyapatite (HAp) formation ability after soaking in a simulated body fluid, MC3T3-E1 cell differentiation and related surface potentials of rutile-type TiO2 surfaces formed on Ti are controlled by varying the Ti heat treatment conditions in a N2 atmosphere containing a trace amount of O2. The zeta potentials of the samples heated at 873 and 973 K for 1 h are large negative and positive values, respectively. Scanning transmission electron microscopy, electron energy loss spectroscopy, and calculations of defect formation energies reveal that nitrogen atoms incorporated into TiO2 during surface formation produce the charged defects (NO)O−1 and (N2)O+2 for the scales formed in 1 h at 873 and 973 K, respectively. HAp formation and MC3T3-E1 cell differentiation is more pronounced on charged nitrogen-doped TiO2 surfaces compared to on an untreated, neutral Ti surface. An adhesive protein such as Fn adsorbs equally on charged and untreated Ti surfaces in culture medium. However, the adsorption of Ca and P was only detected on charged nitrogen-doped TiO2 surfaces. The enhanced adsorption of inorganic ions and Fn is probably responsible for promoting initial stage of osteoblast differentiation. The present findings lead to physical models of surface charge distributions that elucidate the relationship between nitrogen-related defects, charged surfaces and cell differentiation mechanisms. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two-dimensional covalent triazine framework material (2D-CTF) is a kind of covalent organic framework material with triazine ring structure consisting of C and N elements, which is considered to be a type of ideal membrane material due to its excellent structural stability and adjustable in-plane nanopore. In this study, few-layers 2D-CTF-1 nanomaterials were prepared using a micro-interface method based on the polymerization of 1,4-dicyanobenzene. The resulting few-layers 2D-CTF-1 nanosheets were used as building blocks to construct 2D-CTF-1 membrane via a layer-bylayer assembly method. The structure and morphology of the prepared 2D-CTF-1 nanosheets and membrane were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy and scanning electron microscopy. The pure water flux under different pressures and the separation performances of 2D-CTF-1 membrane for small organic dye molecules were tested. The results show that 2D- CTF-1 membrane possesses high pure water flux(153.7 L/(m2·h)) (25 °C, 0.1 MPa), and the in-plane nanopores of 2D-CTF-1 are proposed as the main transport channels for water molecules. Besides, the 2D-CTF-1 membrane exhibits high flux (132.5 L/(m2·h)) (25 °C, 0.1 MPa) and high rejection rate (98.3%) for separation of organic dye (Congo red). The membrane still shows high flux and rejection after a long-term operation. Thus, 2D-CTF-1 is a promising 2D separation membrane material for high efficient molecular separation. [ABSTRACT FROM AUTHOR]

[Objectives] This paper aimed to study the nematicidal activity of the Pseudomonas protegens Pf-5, and to identify the major nematicidal compounds produced by this strain. [Methods] The unmarked deletion mutants of Pf-5 were constructed based on sucrose-induced(sacB gene)lethalality. The model nematodes Caenorhabditis elegans was used as the target. The strains were labeled with green fluorescent protein gene to study the lethal effect of the strain on this nematode. The possible action site of Pf-5 strain was observed by using scanning and transmission electron microscopy. [Results] The Pf-5 strain had strong lethal activity against C. elegans. The LCM of Pf-5 against C. elegans at 48 h and 96 h.was respectively 4.92xl07 CFU·mL-1 and 3.58xlO6 CFU·mL-1. When treated C. elegans with Pf-5 for 48 h, the lethal rate was 73.57%,but when Jit I) gene was knocked out, the lethal activity of PfSufUD was significantly reduced, only 25.04% compared to the wide type. When Delivery domain and CHOPS domain of July gene were respectively deleted, the lethal activity of mutants also significantly decreased. This indicated that the FiteD protein was the major nematicidal substance produced by Pf-5 strain. Scanning electron microscopy showed that Pf-5 strain and its mutant did not destroy the body wall of nematode. But when observed using transmission electron microscopy,the results had showed that the intestinal villi of nematode became thinner, and even fell off, but the mutant Pf-5μfiD didn't have such effect. [Conclusions] The nematicidal substance in the P. protegens Pf-5 strain is the FitD protein,and its site of action is the intestinal tract. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Segmentation effect of super accumulation of heavy metals in plants which can reduce the concentration of metal ions in the cytoplasm of a cell is one of the important mechanisms of heavy metal detoxification. However, the compartmentalization effect from different tissues of a cell does not get a consistent conclusion. In order to evaluate whether intracellular compartmentalization could explain Cd detoxification mechanisms, the work described in this paper was designed to study the effect of exposure time and levels on Cd distribution of Indian mustard (Brassica juncea) at the cell and sub-cell level. Root and leaf samples were exposed to 0.5, 1.0, 2.0, 3.0 and 5.0 mg/L and harvested after 1, 5, 7, 10 and 14 days exposure. Cells were separated into three fractions: cytoderm, soluble fraction and organelle containing fraction using differential centrifugation technique, then Cr from all three fractions was determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Results showed that Cr in cytoderm, cytoplasm and organelles accounted for 50%-64%, 22%-38% and 7%-17% of total cadmium, respectively. It can be clearly indicated that the proportion of Cr in cytoderm is significantly higher than that in cytoplasm and organelles, indicating that compartmentalization of cytoderm plays a prominent role in Cd detoxification. As the exposure concentration and time increases, the content of Cd in cell fraction increases significantly especially after 7 days, which demonstrates that the effect of Cd on plant development is a slow process. Moreover, the excess of Cr stress concentration ( > 1.0 mg/L) would lead to deteriorative damage on plant cells, which was visually identified by TEM research, demonstrating different degrees of damages-plasmolysis, vacuolization and plasmalemma roughness, thus affecting the normal function of cells. These results suggest exposure time and levels are important parameters that must be taken into consideration in the study of the toxicity of heavy metals in plants.