25 research outputs found

    Fabrication of Ligusticum chuanxiong polylactic acid microspheres: A promising way to enhance the hepatoprotective effect on bioactive ingredients

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    hpeer-reviewedLigusticum chuanxiong extract-polylactic acid sustained-release microspheres (LCE-PLA) are fabricated in this study for enhancing both duration and hepatoprotective efficacy of the main bioactive ingredients. LCE-PLA in vitro release, cytotoxicity and in vivo hepatoprotective effect were discussed to evaluate its efficiency and functionality. Results demonstrated that the optimal drug-loading rate and encapsulation efficiency of tetramethylpyrazine (TMP, the main active ingredient) were 8.19%, 83.72%, respectively. The LCE-PLA in vitro release of TMP showed prolong 5-fold and in vitro cytotoxicity declined 25.00% compared with naked LCE. After 6 weeks of in vivo intervention in high fat diet mice, both liver aspartate aminotransferase and alanine aminotransferase levels were higher in LCE-PLA group than LCE group. The above results indicated that TMP had a higher bioavailability of hepatoprotection when encapsulation of LCE-PLA was applied. The current study has provided a promising novel way to enhance the efficacy of short half-life ingredients.National Natural Science Foundation of Chin

    Influence of nitrite on sludge settleability under anoxic and aerobic conditions

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    Three lab-scale automatic control sequencing batch reactors (SBR) were operated by using acetate as the single carbon source, nitrite was dosed to SBR-1 and SBR-2 under anoxic and aerobic conditions, respectively, and SBR 3 was operated as control without dosing. The results show that, the presence of nitrite under anoxic and aerobic conditions would both cause filamentous sludge bulking. A more serious sludge bulking is observed when the nitrite is presented under the anoxic conditions. Nitrite could stimulate the increase of carbohydrates in extracellular polymeric substances, weaken the storage capability of floc-formers and decrease the phosphorous removal efficiency, thus cause the deterioration of sludge settleability. The dominant filaments are both Thiotrix nivea for SBR-1 and SBR-2 when sludge bulking occurred

    Wheat and Rice Growth Stages and Fertilization Regimes Alter Soil Bacterial Community Structure, but Not Diversity

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    Maintaining soil fertility and the microbial communities that determine fertility is critical to sustainable agricultural strategies, and the use of different organic fertilizer regimes represents an important practice in attempts to preserve soil quality. However, little is known about the dynamic response of bacterial communities to fertilization regimes across crop growth stages. In this study, we examined microbial community structure and diversity across eight representative growth stages of wheat-rice rotation under four different fertilization treatments: no nitrogen fertilizer (NNF), chemical fertilizer (CF), organic-inorganic mixed fertilizer (OIMF) and organic fertilizer (OF). Quantitative PCR (QPCR) and high-throughput sequencing of bacterial 16S rRNA gene fragments revealed that growth stage as the best predictor of bacterial community abundance and structure. Additionally, bacterial community compositions differed between wheat and rice rotations. Relative to soils under wheat rotation, soils under rice rotation contained higher relative abundances (RA) of anaerobic and mesophilic microbes and lower RA of aerophilic microbes. With respect to fertilization regime, NNF plots had a higher abundance of nitrogen–fixing Cyanobacteria. OIMF had a lower abundance of ammonia-oxidizing Thaumarchaeota compared with CF. Application of chemical fertilizers (CF and OIMF treatments) significantly increased the abundance of some generally oligotrophic bacteria such those belonging to the Acidobacteria, while more copiotrophic of the phylum Proteobacteria increased with organic fertilizer application. A high correlation coefficient was found when comparing RA of Acidobacteria based upon QPCR versus sequence analysis, yet poor correlations were found for the Alpha- and Beta- Proteobacteria, highlighting the caution required when interpreting these molecular data. In total, crop, fertilization scheme and plant developmental stage all influenced soil microbial community structure, but not total levels of alpha diversity

    Nutrient removal performance and microbial community structure in an EBPR system under the limited filamentous bulking state

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    Limited filamentous bulking (LFB) was proposed to be a new method for saving energy and improving effluent quality. In order to validate the stability of LFB in enhanced biological phosphorus removal (EBPR) systems, the LFB was further achieved in a lab-scale EBPR. Nutrient removal performance and microbial community structure including dominant filaments and polyphosphate-accumulating organisms (PAOs) were investigated. Results showed that the enriched PAOs could alleviate the negative effect of low dissolved oxygen concentration on sludge settleability, making the LFB be more easily achieved and maintained in the EBPR for long-term operation. Sludge volume index was kept between 150-200. mL/g during the LFB period. Larger floc size (≥400μm) was commonly observed under the LFB state, which significantly enhanced the simultaneous nitrification and denitrification (SND) efficiency. An average SND efficiency of 36% was observed in the EBPR system when the LFB occurred

    A Real-Time Strand Breakage Detection Method for Power Line Inspection with UAVs

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    Power lines are critical infrastructure components in power grid systems. Strand breakage is a kind of serious defect of power lines that can directly impact the reliability and safety of power supply. Due to the slender morphology of power lines and the difficulty in acquiring sufficient sample data, strand breakage detection remains a challenging task. Moreover, power grid corporations prefer to detect these defects on-site during power line inspection using unmanned aerial vehicles (UAVs), rather than transmitting all of the inspection data to the central server for offline processing which causes sluggish response and huge communication burden. According to the above challenges and requirements, this paper proposes a novel method for detecting broken strands on power lines in images captured by UAVs. The method features a multi-stage light-weight pipeline that includes power line segmentation, power line local image patch cropping, and patch classification. A power line segmentation network is designed to segment power lines from the background; thus, local image patches can be cropped along the power lines which preserve the detailed features of power lines. Subsequently, the patch classification network recognizes broken strands in the image patches. Both the power line segmentation network and the patch classification network are designed to be light-weight, enabling efficient online processing. Since the power line segmentation network can be trained with normal power line images that are easy to obtain and the compact patch classification network can be trained with relatively few positive samples using a multi-task learning strategy, the proposed method is relatively data efficient. Experimental results show that, trained on limited sample data, the proposed method can achieve an F1-score of 0.8, which is superior to current state-of-the-art object detectors. The average inference speed on an embedded computer is about 11.5 images per second. Therefore, the proposed method offers a promising solution for conducting real-time on-site power line defect detection with computing sources carried by UAVs

    Preparation and immunoprotective effects of a virus-like particle candidate vaccine of the dominant epidemic D3 genotype coxsackievirus A6 in China

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    Coxsackievirus A6 of the D3a genotype (CVA6 D3a) is a primary pathogen causingmainland of China's hand, foot, and mouth disease (HFMD). Viral-like particle (VLP) vaccines represent a potential candidate vaccine to prevent HFMD. This study collected Anti-CVA6 D3a VLPs serum from BALB/c female mice immunized using CVA6 D3a VLPs. The neutralizing antibody levels were compared against the representative 14-JX2018 (D3a) and N4-YN2015 (D3b) strains between the antisera of different immune pathways. The immunoprotective effect of anti-CVA6 D3a VLPs against these strains was monitored using pathological sections and immunohistochemical results of lung and skeletal muscle tissues in seven-day-old Institute of Cancer Research (ICR) mice. Immunological protection against different branches of viruses was evaluated in 7-day-old (serum passive immune protection) and 14-day-old (VLPs active immune protection) neonatal ICR mice models. Serum-neutralizing antibody levels were positively correlated with the number of immunizations and higher against 14-JX2018 than against N4-YN2015. Furthermore, these levels were significantly higher with abdominal injection than intramuscular injection. The immunized serum of 7-day-old ICR mice inoculated three times was 100 % protected against CVA6 D3a 14-JX2018 (lethal titer: 106.25 TCID50) and CVA6 D3b N4-YN2015 (lethal titer: 105.25TCID50) fatal attacks, respectively. For ICR mice that have completed two active immunizations for 14 days, both CVA6 D3a 14-JX2015 (challenge titer: 108.25 TCID50) and CVA6 D3b N4-YN2015 (challenge titer: 107.25 TCID50) were used for the challenge, and the mice were able to survive. Overall, the CVA6 D3a VLPs prepared in this study are a potential vaccine candidate for CVA6, as it has the optimal protective effect against both CVA6 D3a and D3b evolutionary branches viruses
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