Continuous cropping system altered soil microbial communities and nutrient cycles

Understanding the response of microbial communities and their potential functions is essential for sustainability of agroecosystems under long-term continuous cropping. However, limited research has focused on investigating the interaction between soil physicochemical factors and microbial community dynamics in agroecosystems under long-term continuous cropping. This study probed into the physicochemical properties, metabolites, and microbial diversity of tobacco rhizosphere soils cropped continuously for 0, 5, and 20 years. The relative abundance of bacterial genera associated with nutrient cycling (e.g., Sphingomonas) increased while potential plant pathogenic fungi and beneficial microorganisms showed synergistic increases with the duration of continuous cropping. Variations in soil pH, alkeline nitrogen (AN) content, and soil organic carbon (SOC) content drove the shifts in soil microbial composition. Metabolites such as palmitic acid, 3-hydroxypropionic acid, stearic acid, and hippuric acid may play a key role in soil acidification. Those results enhance our ability to predict shifts in soil microbial community structure associated with anthropogenic continuous cropping, which can have long-term implications for crop production

Facile synthesis, structure and visible light photocatalytic activity of recyclable ZnFe2O4/TiO2

A kind of sponge-like ZnFe2O4/TiO2 composite was facilely synthesized by a solution combustion method. The physicochemical properties, including the crystalline phase, surface morphology, spectral response, photogenerated charge carriers' separation and transfer efficiency, were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N-2 adsorption/desorption isotherms, X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy and photoluminescence spectroscopy techniques and analyzed to interpret the relationship between the structure and photocatalytic activity. The sponge-like morphology promotes the adsorption of reaction species as well as functions as a good light harvesting structure for the enhancement of spectral utilization. The hetero-junction effectively inhibited the recombination of photogenerated charge carriers. With these synergistic effects, the degradation rate of methylene blue on ZnFe2O4/TiO2 was up to 93.2% under visible light irradiation and remained stable even after five consecutive reaction runs. Moreover, owing to the magnetic property, ZnFe2O4/TiO2 can be recycled easily. Additionally, a photocatalytic mechanism of ZnFe2O4/TiO2 was proposed. (C) 2014 Elsevier B. V. All rights reserved

Co-delivery of gemcitabine and Triapine by calcium carbonate nanoparticles against chemoresistant pancreatic cancer

Pancreatic cancer is a malignant disease with high mortality, and its systemic treatment strategy mainly focuses on chemotherapy. Yet, the overall prognosis of pancreatic cancer patients is still extremely poor with a low survival rate. Gemcitabine (GEM) is a widely used chemotherapeutic agent for the treatment of pancreatic cancer. However, GEM chemoresistance remains the major challenge. In this study, we prepared calcium carbonate nanoparticles (CaCO3 NPs) loaded with a nucleotide reductase inhibitor (Triapine) and GEM to suppress the GEM resistance of pancreatic cancer cells (PANC-1/GEM) and solve the problem of poor solubility of Triapine. CaCO3-GEM-Triapine NPs nano-formulations enhanced the therapeutic effect of GEM-based chemotherapy by inhibiting cancer cell proliferation, migration, and resistance to GEM using both 2D PANC-1/GEM cells and 3D tumor spheroids. The study indicated that CaCO3 NPs loaded with GEM and Triapine could provide an effective treatment option to overcome drug resistance in pancreatic cancer

Mechanism Study of Photocatalytic Degradation of Gaseous Toluene on TiO2 with Weak-Bond Adsorption Analysis Using In Situ Far Infrared Spectroscopy

The development of far infrared spectroscopy offers a powerful method for comprehensive study in adsorption structure and photocatalytic degradation mechanism of photocatalysis. This study presented an improved in situ diffuse reflectance infrared Fourier transform spectroscopy technique in far infrared region for investigation of weak-bond adsorption and photocatalytic degradation of gaseous toluene on the surface of TiO2. It was found that toluene tends to be adsorbed on the hydroxyl group via three possible sites, the ortho-, meta-, and para-adsorption site, instead of ipso-structure. The methyl group of toluene is consumed first during the process of toluene photocatalytic degradation. Based on these, a reaction route for the photocatalytic degradation of gaseous toluene on TiO2 surface was proposed

DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO2 with Relative Photocatalytic Properties

Effective adsorption is of great importance to the photocatalytic degradation of volatile organic compounds. Herein, we succeeded in the preparation of anatase TiO2 with clean dominant {001} and {101} facets. By using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) equipped with a homemade reaction system and a coupling gas-dosing system, we found that TiO2 with dominant {001} facets exhibits higher toluene adsorption capacity than TiO2 with dominant {101} facets, which may be attributed to the different number of unsaturated 5c-Ti capable of forming the main active adsorption sites (terminal Ti-OH species). TiO2 with dominant {001} facets shows a significantly high photocatalytic degradation performance, with its degradation rate being 6 times higher than that of dominant {101} facets. Combined with simulation results, it is suggested that the synergetic effects of the formation of specific active adsorption sites, the low adsorption energy for toluene, and preservation of the free molecularly adsorbed water on the surface promote the degradation of gaseous toluene on the dominant {001} facets. This study exemplifies that the facet-dependent adsorption of volatile organic compounds is one of the most important factors to effectively engineer photocatalysts for air purification

PO-039 Influence of Physical Activity on Aerobic Endurance Capacity on Primary School Students

Objective The physical fitness of primary school students is not optimistic in recent years. The obesity rate and myopia rate have continuously increased, and the aerobic endurance capacity has insistently declined. The aerobic endurance capacity is an important indicator to evaluate the physical fitness of students. This article explores the effects of physical activity(PA) designed by NSPEL on the improvement of aerobic endurance by intervening in the fourth grade students of Shifoying Primary School in Chaoyang District in Beijing, and provides a reference for students' physical fitness promotion. Methods 155 fourth-grade students from Shifoying primary School in Beijing were selected as subjects. They were subjected to PA intervention for 16 weeks and their physical fitness related indicators were evaluated. PA intervention includes in-class and extracurricular sports activities. Physical education was guided by the syllabus. Extracurricular sports activities were mainly activities in break and after-school sports interest classes. The final analysis of the physical fitness assessment scores, BMI, 50m run, 50-meter shuttle run, skipping and sit-up were performed before and after the intervention. Results The average score of physical fitness assessment of students was 79.79 before PA intervention, and the score was significantly increased and increased to 88.12 (10.43%) after the intervention. Physical shape of the students changed significantly after PA intervention. The mean of BMI was within the normal range before and after intervention, and the obesity rate was reduced by 1.29%. The student's speed capacity improved significantly after the intervention, the average score of the 50-meter race increased from 10.22 seconds to 7.90 seconds, the difference was very significant, with an increase of 2.32 seconds after the intervention. The student's aerobic endurance capacity was significantly improved before and after PA intervention. The average score of the 50 meter shuttle run was increased from 2.01 min to 1.74 min, and the result was significantly improved by 13.43%. The average score of sit-up was 21.64, and it increased to 42.30 after the intervention, with an average increase of 20.66. Conclusions Students' physical fitness assessment scores improved significantly after PA in and out of class, suggesting that PA effectively improved the physical fitness status of 11-year-old pupils. Students' 50-meter run, 50 meter shuttle run, skipping, and sit-ups were all significantly improved after PA interventions, suggesting that PA is of great significance for improving aerobic endurance. The combination of activities inside and outside class can be used as a reference mode to improve students' physical fitness (NSFC31401018, SKXJX2014014, [email protected])

Evaluation of Anti-Inflammatory Activities of Qingre-Qushi Recipe (QRQS) against Atopic Dermatitis: Potential Mechanism of Inhibition of IL-33/ST2 Signal Transduction

To evaluate the anti-inflammatory activities of QRQS against AD and the inhibitory molecular mechanisms of IL-33/ST2 signal transduction, BALB/c mice were divided into six groups (normal control, OVA control, low-dose of QRQS, middle-dose of QRQS, high-dose of QRQS, and cetirizine) and epicutaneously exposed to ovalbumin or PBS for 3 weeks and treated with QRQS for 2 weeks. Skin biopsies and blood samples were obtained for histological study, antibody analysis, and RNA isolation. HaCaT cells, stimulated by TNF-α and IFN-γ, were treated with QRQS to evaluate mRNA and protein expression by RT-PCR and ELISA. QRQS decreased both epidermal and dermal thickness, alleviated dermatitis, and reduced IL-33 and ST2 positive cell numbers. The concentration of specific IgE, IgG, IgG1, and IgG2a antibodies in serum and the expression of IL-33, ST2, IL-1RAcP, IL-4, and IL-13 mRNA in the skin were suppressed. No significant difference exists in TNF-α or IFN-γ. QRQS decreased IL-33 mRNA and protein secretion in HaCaT cells exposed to TNF-α and IFN-γ in a time- and concentration-dependent manner. QRQS regulates related molecule expression of ovalbumin-induced dermatitis involved in the IL-33/ST2 signaling axis in the treatment of acute AD

Genome-wide identification and analysis of heterotic loci in three maize hybrids

Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identifies 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with complete–incomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the major causes of strong heterosis in these hybrids. Follow-up studies for 17 heterotic loci in an independent experiment using 2225 F2 individuals suggest most heterotic effects are roughly stable between environments with a small variation. Candidate gene analysis for one major heterotic locus (ub3) in maize implies that there may exist some common genes contributing to crop heterosis. These results provide a community resource for genetics studies in maize and new implications for heterosis in plants

A Study on the Application of Multimodal Vocabulary Teaching Mode

This study used questionnaires, interviews and teaching experiments to investigate the effectiveness of multimodal teaching mode in English vocabulary teaching. It was found that multimodal vocabulary teaching could improve teachers’ vocabulary teaching ability, promote students’ vocabulary learning ability and enhance their pragmatic skills. In English vocabulary teaching of junior high school, teachers should make full use of multimodal resources to mobilize students’ senses, bring into play their subjective motivation of vocabulary learning, and improve the efficiency of classroom vocabulary learning. At the same time, there are certain difficulties in applying multimodal theory-teachers need to choose the appropriate modality according to the actual situation

On the Difference of River Resistance Computation between the k − ε Model and the Mixing Length Model

River resistance characteristics, which can be reflected by the resistance factor, have an impact on flow and sediment transport. In the classical theory, Prandtl proposed the mixing length model for the simulation of the turbulence, and von Kármán established the logarithmic formula of the flow velocity distribution. Based on that, the expression of the resistance factor can be derived. With the development of the numerical technology, the k−ε model has been widely applied in the channels computation. However, for the different closure ways of the Reynolds stress in turbulence equations, the outcomes of the k−ε model and the Prandtl mixing length model are not exactly identical. In this paper, both qualitative and quantitative studies are carried out on the difference between these two models, with respect to the resistance factor. This difference is evaluated by the ratio of the resistance factor computed with the two models. The result shows that with the increment of the relative flow depth, the ratio first increases and then decreases. Moreover, it is also affected by the bed slope. Therefore, the difference should be taken into account when a comparison is made between the simulation results of the k−ε model and the classical theory of river mechanics