Curvature-mediated rapid extravasation and penetration of nanoparticles against interstitial fluid pressure for improved drug delivery.

Elevated interstitial fluid pressure (IFP) within pathological tissues (e.g., tumors, obstructed kidneys, and cirrhotic livers) creates a significant hindrance to the transport of nanomedicine, ultimately impairing the therapeutic efficiency. Among these tissues, solid tumors present the most challenging scenario. While several strategies through reducing tumor IFP have been devised to enhance nanoparticle delivery, few approaches focus on modulating the intrinsic properties of nanoparticles to effectively counteract IFP during extravasation and penetration, which are precisely the stages obstructed by elevated IFP. Herein, we propose an innovative solution by engineering nanoparticles with a fusiform shape of high curvature, enabling efficient surmounting of IFP barriers during extravasation and penetration within tumor tissues. Through experimental and theoretical analyses, we demonstrate that the elongated nanoparticles with the highest mean curvature outperform spherical and rod-shaped counterparts against elevated IFP, leading to superior intratumoral accumulation and antitumor efficacy. Super-resolution microscopy and molecular dynamics simulations uncover the underlying mechanisms in which the high curvature contributes to diminished drag force in surmounting high-pressure differentials during extravasation. Simultaneously, the facilitated rotational movement augments the hopping frequency during penetration. This study effectively addresses the limitations posed by high-pressure impediments, uncovers the mutual interactions between the physical properties of NPs and their environment, and presents a promising avenue for advancing cancer treatment through nanomedicine.

Seasonal hydrological dynamics affected the diversity and assembly process of the antibiotic resistome in a canal network.

The significant threat of antibiotic resistance genes (ARGs) to aquatic environments health has been widely acknowledged. To date, several studies have focused on the distribution and diversity of ARGs in a single river while their profiles in complex river networks are largely known. Here, the spatiotemporal dynamics of ARG profiles in a canal network were examined using high-throughput quantitative PCR, and the underlying assembly processes and its main environmental influencing factors were elucidated using multiple statistical analyses. The results demonstrated significant seasonal dynamics with greater richness and relative abundance of ARGs observed during the dry season compared to the wet season. ARG profiles exhibited a pronounced distance-decay pattern in the dry season, whereas no such pattern was evident in the wet season. Null model analysis indicated that deterministic processes, in contrast to stochastic processes, had a significant impact on shaping the ARG profiles. Furthermore, it was found that Firmicutes and pH emerged as the foremost factors influencing these profiles. This study enhanced our comprehension of the variations in ARG profiles within canal networks, which may contribute to the design of efficient management approaches aimed at restraining the propagation of ARGs.

Dynamics of the sedimentary bacterial communities in a plain river network: similar coalescence patterns with bacterioplankton communities driven by distinct assembly processes.

IMPORTANCE: Microorganisms play important roles in driving the biogeochemical cycles within river ecosystems. It has been suggested that hydrologic conditions could influence microbial communities in rivers, but their specific effects on the behaviours of microbial coalescence have not been thoroughly investigated. In this study, the dynamics of sedimentary bacterial communities within a plain river network were analyzed by amplicon sequencing followed by several ecological models to uncover the underlying assembly processes. Additionally, a comparative analysis between bacterioplankton communities and sedimentary bacterial communities was performed to unveil their coalescence patterns. The results suggested that similar coalescence patterns between sedimentary bacterial and bacterioplankton communities were driven by distinct assembly processes under dynamic hydrological conditions. These findings enhanced our understanding of microbial diversity features within river ecosystems.

DNA Three-Way Junction with Multiple Recognition Regions Mediated an Unconfined DNA Walker for Electrochemical Ultrasensitive Detection of miRNA-182-5p.

In this work, a DNA three-way junction (TWJ) with multiple recognition regions was intelligently engineered, which could be applied as an unconfined DNA walker with a rapid walking speed and high sensitivity for electrochemical detection of microRNA (miRNA-182-5p). Once the target miRNA was presented, the hairpins on TWJ could be successively opened to form an annular DNA walker, which could walk on the entire scope of the electrode surface without the confine for the length of DNA walker legs compared with the traditional DNA walker, greatly improving the walking efficiency. In addition, this DNA walker with multirecognition segments could obviously increase the local concentration of recognition sites, which significantly enhanced the detection speed and sensitivity. As a result, this proposed biosensor with annular DNA as a walker could dexterously achieve the ultrasensitive and fast detection of miRNA-182-5p from 0.1 fM to 1 nM with a detection limit of 31.13 aM. Meaningfully, this strategy explored an innovative path in the design of a new DNA walker nanostructure for accomplishing speedy and sensitive detection of biomarkers.

Influence of Er3+ concentration and Ln3+ on the Judd-Ofelt parameters in LnOCl (Ln = Y, La, Gd) phosphors.

The optical transition properties of trivalent rare earth (RE3+) doped luminescent materials have received extensive attention. The Judd-Ofelt theory is an effective tool for exploring the optical transition properties for the 4f-4f transitions of lanthanides. The aim of this work is to discover the effect of Er3+ concentration and different Ln3+ ions on the Judd-Ofelt parameters in LnOCl:Er3+ (Ln = Y, La, Gd) phosphors. Oxychloride LnOCl:Er3+ (Ln = Y, La, Gd) phosphors were produced via a single displacement reaction technique. The Judd-Ofelt calculation procedure for RE3+ doped powders was modified and then adopted to obtain the Judd-Ofelt parameters of Er3+ in the studied phosphors. Meanwhile, a new route for examining the Judd-Ofelt calculation quality was proposed and used. It was found that the Er3+ doping concentration slightly affects the optical transition properties of Er3+ in YOCl and LaOCl, but greatly affects the optical transition properties in GdOCl. Moreover, it was also found that the optical transition properties of Er3+ depend also on Ln3+ (Ln = Y, La, Gd) though the crystal structure of these compounds is similar. The Judd-Ofelt parameters of Er3+ are the smallest in LaOCl:Er3+, medium in YOCl:Er3+, but the biggest in GdOCl:Er3+ when the doping concentration is the same.

Fluorescence decay route of optical transition calculation for trivalent rare earth ions and its application for Er3+-doped NaYF4 phosphor.

Usually, the optical transition properties of trivalent rare earth (RE) ions in transparent hosts can be quantitatively investigated in the framework of Judd-Ofelt theory. A standard and commonly accepted calculation procedure based on the absorption spectrum has already been established. However, it is hard to assess the optical transition properties of trivalent RE ions doped in powdered and film materials owing to the difficulty in the absolute absorption spectrum measurements. In this work, we proposed a new route to calculate the Judd-Ofelt parameters of trivalent RE ion-doped materials in any morphological and shaped forms. In this method, the fluorescence decay values bridging the radiative transition rates and the Judd-Ofelt parameters were used. As an application example of the proposed Judd-Ofelt calculation method, the Judd-Ofelt parameters of Er3+ in NaYF4 were calculated via the proposed route, and it was found that the obtained results are in reasonable accordance with those derived from other routes. It was also proved that this proposed Judd-Ofelt calculation method is a practicable and effective route for evaluating optical transition properties of trivalent RE ions in non-transparent hosts as long as the fluorescence decay values can be measured.

High-throughput characterization of the expressed antibiotic resistance genes in sewage sludge with transcriptional analysis.

Antibiotic resistance genes (ARGs) are emerging micro-pollutants that pose potential threats to environments and humans. Sewage sludge from wastewater is an important source for ARGs and current studies mainly focus on their existence in microbial genomes. However, little is known about which ARGs are expressed even though ARGs expression remains a better proxy for functional activity. In this study, the expressed ARGs in sewage sludge were characterized by high-throughput quantitative PCR (296 primer sets) combined with transcriptional analysis. A total of 202 ARG transcripts were detected and their abundances ranged from 3.1 × 109 to 1.2 × 1010 copies/g dry weight. The sum abundance of five most abundant ARG transcripts (qacEdelta1-02, sul2, qacEdelta1-01, aadA2-03, tetX) exhibited a linear correlation with the total abundance of ARG transcripts (R2 = 0.88, p < 10-4), suggesting that these genes could be regarded as indicators to quantitatively predict the total abundance of expressed ARGs. Dynamics of expressed ARGs were observed with lower abundances in summer and winter than those in other seasons (p < 0.05, Kruskal-Wallis test). Variation partitioning analysis indicated that the shift in bacterial community structures induced by changes in environmental attributes might be the main driver for the dynamics of expressed ARGs. Results of this study provided new insights into the ARGs in sewage sludge.

Reply to the 'Comment on "A universal approach for calculating the Judd-Ofelt parameters of RE3+ in powdered phosphors and its application for the ß-NaYF4:Er3+/Yb3+ phosphor derived from auto-combustion-assisted fluoridation"' by D. Zhang, Q. Xu and Y. Zhang, Phys. Chem. Chem. Phys., 2019, 21, DOI: 10.1039/C8CP07577H.

In this Reply, we truthfully respond to the comments on our recent paper entitled "A universal approach for calculating the Judd-Ofelt parameters of RE3+ in powdered phosphors and its application for the ß-NaYF4:Er3+/Yb3+ phosphor derived from auto-combustion-assisted fluoridation" published in Phys. Chem. Chem. Phys. [Y. Zhang, B. Chen, S. Xu, X. Li, J. Zhang, J. Sun, X. Zhang, H. Xia, R. Hua, A universal approach for calculating the Judd-Ofelt parameters of RE3+ in powdered phosphors and its application for the beta-NaYF4:Er3+/Yb3+ phosphor derived from auto-combustion-assisted fluoridation, Phys. Chem. Chem. Phys., 20, 2018, 15876-15883]. In the Comment, the authors oppugned partial calculation results we reported in our original paper, thus we redid the calculations and compared the presently obtained results with the original ones and the author provided ones. The recalculations and comparisons confirmed that our calculations are reproducible and the results are correct. In the Comment, the authors also made some comments on the Judd-Ofelt calculation approaches for powdered samples reported by other researchers. Following the authors' train of thought we added some supplements to the comments to understand the application strategy of Judd-Ofelt theory. Furthermore, we extended some points of view regarding the fluorescence lifetime measurements the authors presented in the Comment.

Detection of Type, Blended Ratio, and Mixed Ratio of Pu'er Tea by Using Electronic Nose and Visible/Near Infrared Spectrometer.

The objective of this study was to find an intelligent and fast method to detect the type, blended ratio, and mixed ratio of ancient Pu'er tea, which is significant in maintaining order in the Pu'er tea industry. An electronic nose (E-nose) and a visible near infrared spectrometer (VIS/NIR spectrometer) were applied for tea sampling. Feature extraction was conducted using both the traditional method and a convolutional neural network (CNN) technique. Linear discriminant analysis (LDA) and partial least square regression (PLSR) were applied for pattern recognition. After sampling while using the traditional method, the analysis of variance (ANOVA) results showed that the mean differential value of each sensor should be selected as the optimal feature extraction method for E-nose data, and raw data comparison results showed that 19 peak/valley values and two slope values were extracted. While the format of E-nose data was in accord with the input format for CNN, the VIS/NIR spectrometer data required matrixing to meet the format requirements. The LDA and PLSR analysis results showed that CNN has superior detection ability, being able to acquire more local features than the traditional method, but it has the risk of mixing in redundant information, which can act to reduce the detection ability. Multi-source information fusion (E-nose and VIS/NIR spectrometer fusion) can collect more features from different angles to improve the detection ability, but it also contains the risk of adding redundant information, which reduces the detection ability. For practical detection, the type of Pu'er tea should be recognizable using a VIS/NIR spectrometer and the traditional feature extraction method. The blended ratio of Pu'er tea should also be identifiable by using a VIS/NIR spectrometer with traditional feature extraction. Multi-source information fusion with traditional feature extraction should be used if the accuracy requirement is extremely high; otherwise, a VIS/NIR spectrometer with traditional feature extraction is preferred.

A new and important relationship between miRNA-147a and PDPK1 in radiotherapy.

It was found that the expression level of miR-147a was significantly increased and the pathway of PI3K/AKT was dramatically inhibited after radiation. In view of the relationship between miRNA and target genes, we put forward the question, what is the relationship between PI3K/AKT and miR-147a? In order to find the answer to the question, we used bioinformatics techniques to analyze the relationship between miR-147 (a or b) and PI3K/AKT signaling pathway. miR-147a overexpression plasmid and PDPK1 3'UTR luciferase reporter gene plasmid were constructed. Dual luciferase reporter gene system validation experiments were carried out on miR-147a and PDPK1 relationship. The verification experiments were also carried out. Bioinformatics analysis showed that there is a miR-147a binding site in the non-coding region (3'UTR) of PDPK1. In the experimental groups transfected with wild type PDPK1 gene of 3'UTR plasmid, the luciferase activity decreased (or increased) significantly in miR-147a (or inhibitor) group compared with miR-NC (or anti-miR-NC); There was no significant difference between the miR-147a group (or inhibitor) and the miR-NC group (or anti-miR-NC) in the transfection of PDPK1-3'UTR-Mut gene vector. PDPK1 was a target gene for direct regulation of miR-147a downstream. Verifying test results showed that the expression of PDPK1 mRNA and protein was reduced after overexpression of miR-147a, which was up-regulated after silencing miR-147a in TC, and V79 cells. These results suggest that miR-147a could be involved in the regulation of PDPK1 transcription by binding to the target site in PDPK1 mRNA 3'UTR, and then regulated AKT.

Flavonoids of Rosa roxburghii Tratt offers protection against radiation induced apoptosis and inflammation in mouse thymus.

The present study evaluated the protective effect of the natural compound flavonoids of Rosa roxburghii Tratt (FRT) against γ-radiation-induced apoptosis and inflammation in mouse thymus cells in vivo and in vitro. Thymus cells and mice were exposed to 60Co γ-ray at a dose of 6 Gy. The radiation treatment induced significant cell apoptosis and inflammation. Radiation increased the expressions of cleaved caspase 3/8-10, AIF, and PARP-1, and FRT could mitigate their activation and inhibit subsequent apoptosis in the thymus both in vitro or in vivo. Irradiation increased the mRNA expression of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-κB. Our results also indicated that FRT alleviated gene expression of some inflammatory factors such as ICAM-1/VCAM-1, TNF-α/NF-κB, but not IL-1α/IL-6. Irradiation increased the protein expression levels of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-Κb, and our results also indicated that FRT alleviated protein level expression of certain inflammatory factors such as ICAM-1, IL-1α/IL-6, TNF-α/NF-κB, but not VCAM-1. Our results suggested that FRT enhanced radioprotection at least partially by regulating caspase 3/8-10, AIF, and PARP-1 to reduce apoptosis and by regulating ICAM-1, IL-1α/IL-6, TNF-α/NF-κB to reduce inflammation.

Highly stable and tunable white luminescence from Ag-Eu3+ co-doped fluoroborate glass phosphors combined with violet LED.

Ag-Eu3+ co-doped fluoroborate glass phosphors doped with various Eu3+-concentrations were prepared by a melt-quenching technique. The luminescent properties of these glass phosphors were characterized by excitation and emission spectra. Broad excitation and emission bands located, respectively, at 300-450 nm and 390-700 nm originating from silver aggregates were observed. Strong red emissions were detected under 404 nm violet light-emitting diode (LED) excitation for those Ag-Eu3+ co-doped samples. It was found that these red emissions of Eu3+ well compensated the deficiency of the red spectral components in glasses containing Ag aggregates. In addition, it was confirmed that stable white light could be achieved from the combination of a specific Ag-Eu3+ co-doped fluoroborate glass phosphor and LEDs with different output wavelengths. By adjusting the luminescence intensity ratio of the glass phosphor to the 404 nm violet LED, tunable emitting color was realized, and the studied glass phosphors showed excellent emitting color stability toward LED drive currents. Our results demonstrated that this kind of easy fabrication, low-cost, and highly stable Ag-Eu3+ co-doped fluoroborate glass phosphors had potential application in white LED.

A universal approach for calculating the Judd-Ofelt parameters of RE3+ in powdered phosphors and its application for the ß-NaYF4:Er3+/Yb3+ phosphor derived from auto-combustion-assisted fluoridation.

It is difficult to calculate the Judd-Ofelt (J-O) parameters for trivalent rare earth (RE)-doped powders due to the unavailable absorption spectrum that is necessarily used in the conventional J-O calculation procedure. In this study, a universal method starting from the diffuse-reflection spectrum for calculating the J-O parameters of RE3+-doped powdered samples was proposed. In this proposed method, by taking the Kubelka-Munk function into account, the absorption cross-section spectrum was derived from the diffuse-reflection spectrum in the RE3+-doped powdered sample using the connection between the absorption cross section and the radiative transition rate of RE3+. Then, the J-O parameters might be calculated from the absorption cross-section spectrum via the traditional J-O calculation technique. The NaYF4:Er3+/Yb3+ and NaYF4:Er3+ phosphors were prepared via an auto-combustion-assisted fluoridation technique, and the J-O calculation was carried out for the obtained samples. The obtained J-O parameters were compared with those reported in the literature and also verified by comparing the calculated radiative transition lifetimes with the experimental values. Finally, it was deduced that the proposed J-O calculation route was practicable.

Mesoporous silica coating NaYF4:Yb,Er@NaYF4 upconversion nanoparticles loaded with ruthenium(II) complex nanoparticles: Fluorometric sensing and cellular imaging of temperature by upconversion and of oxygen by downconversion.

Accurate detection of temperature and oxygen concentration at the cellular level is important in tumor diagnosis. Multifunctional nanocomposites are described that consist of upconversion luminescent nanoparticles capped with mesoporous silica and loaded with an oxygen-sensitive luminescent ruthenium complex. The nanocomposites of type NaYF4:Yb,Er@NaYF4@mSiO2-Ru have two modes of operation: Its red downconversion luminescence (at excitation/emission peaks of 455/606 nm) is quenched by oxygen (O2), and this is used to sense and image O2. The green upconversion luminescence (typically acquired at excitation/emission wavelengths of 980/525 and 544 nm), in turn, is used to measure temperature. The nanocomposites were then applied to dual mode in-vitro imaging of temperature and O2 in hepatocellular carcinoma cells (HepG-2). Graphical abstract A new multifunctional nanocomposite of mesoporous silica coating NaYF4:Yb,Er@NaYF4 upconversion nanopaticless loaded with ruthenium (II) complex has been designed with both green upconversion and red downconversion luminescence for temperature detection, oxygen sensing and dual mode cell imaging.

Detecting and Monitoring the Flavor of Tomato (Solanum lycopersicum) under the Impact of Postharvest Handlings by Physicochemical Parameters and Electronic Nose.

The objective of this study was to detect and monitor the flavor of tomatoes, as impacted by different postharvest handlings, including chilling storage (CS) and blanching treatment (BT). CS tomatoes were stored in a refrigerator at 5 °C and tested at storage day 0, 3, and 7. BT tomatoes were dipped in 50 or 100 °C water for 1 min, and tested immediately. The taste, mouth feel, and aroma of tomatoes were evaluated by testing the total soluble solid content (TSS), titratable acidity (TA), ratio of TSS and TA (TSS/TA), firmness, and electronic nose (E-nose) response to tomatoes. The experimental results showed that the CS can prevent taste and firmness loss to a certain extent, but the sensory results indicated that CS accelerated flavor loss due to the TSS/TA of CS tomatoes increasing slower than control. The taste and firmness of tomatoes were impacted slightly by 50 °C BT, and were significantly impacted by 100 °C BT. Based on physicochemical parameters, different postharvest handling treatments for tomatoes could not be classified except for the 100 °C BT treated tomatoes, which were significantly impacted in terms of taste and mouth feel. The E-nose is an efficient way to detect differences in postharvest handling treatments for tomatoes, and indicated significant aroma changes for CS and BT treated tomato fruit. The classification of tomatoes after different postharvest handling treatments, based on comprehensive flavor (physicochemical parameters and E-nose combined data), is better than that based on single physicochemical parameters or E-nose, and the comprehensive flavor of 100 °C BT tomatoes changed the most. Even so, the tomato flavor change during postharvest handlings is suggested to be detected and monitored by single E-nose data. The E-nose has also been proved as a feasible way to predict the TSS and firmness of tomato fruit rather than TA or TSS/TA, during the postharvest handing process.

Single-Kernel FT-NIR Spectroscopy for Detecting Supersweet Corn (Zea mays L. Saccharata Sturt) Seed Viability with Multivariate Data Analysis.

The viability and vigor of crop seeds are crucial indicators for evaluating seed quality, and high-quality seeds can increase agricultural yield. The conventional methods for assessing seed viability are time consuming, destructive, and labor intensive. Therefore, a rapid and nondestructive technique for testing seed viability has great potential benefits for agriculture. In this study, single-kernel Fourier transform near-infrared (FT-NIR) spectroscopy with a wavelength range of 1000-2500 nm was used to distinguish viable and nonviable supersweet corn seeds. Various preprocessing algorithms coupled with partial least squares discriminant analysis (PLS-DA) were implemented to test the performance of classification models. The FT-NIR spectroscopy technique successfully differentiated viable seeds from seeds that were nonviable due to overheating or artificial aging. Correct classification rates for both heat-damaged kernels and artificially aged kernels reached 98.0%. The comprehensive model could also attain an accuracy of 98.7% when combining heat-damaged samples and artificially aged samples into one category. Overall, the FT-NIR technique with multivariate data analysis methods showed great potential capacity in rapidly and nondestructively detecting seed viability in supersweet corn.

New molecular method to detect denitrifying anaerobic methane oxidation bacteria from different environmental niches.

The denitrifying anaerobic methane oxidation is an ecologically important process for reducing the potential methane emission into the atmosphere. The responsible bacterium for this process was Candidatus Methylomirabilis oxyfera belonging to the bacterial phylum of NC10. In this study, a new pair of primers targeting all the five groups of NC10 bacteria was designed to amplify NC10 bacteria from different environmental niches. The results showed that the group A was the dominant NC10 phylum bacteria from the sludges and food waste digestate while in paddy soil samples, group A and group B had nearly the same proportion. Our results also indicated that NC10 bacteria could exist in a high pH environment (pH9.24) from the food waste treatment facility. The Pearson relationship analysis showed that the pH had a significant positive relationship with the NC10 bacterial diversity (p<0.05). The redundancy analysis further revealed that the pH, volatile solid and nitrite nitrogen were the most important factors in shaping the NC10 bacterial structure (p=0.01) based on the variation inflation factors selection and Monte Carlo test (999 times). Results of this study extended the existing molecular tools for studying the NC10 bacterial community structures and provided new information on the ecological distributions of NC10 bacteria.

NaYF4:Sm3+/Yb3+@NaYF4:Er3+/Yb3+ core-shell structured nanocalorifier with optical temperature probe.

A core-shell structure with a NaYF4:Sm3+/Yb3+ core for photothermal conversion nanocalorifier and a NaYF4:Er3+/Yb3+ shell as temperature probe for potential applications in photothermal therapy (PTT) were synthesized by a thermal decomposition technique of rare-earth oleate complexes. The optical temperature reading-out property for the NaYF4:Sm3+/Yb3+@NaYF4:Er3+/Yb3+ core-shell structure was systematically investigated and it was found that in comparison with pure NaYF4:Er3+/Yb3+ particles, the temperature sensing performance of the NaYF4:Er3+/Yb3+ shell did not become worse due to the presence of NaYF4:Sm3+/Yb3+ core. Furthermore, the photothermal conversion behavior for core-shell nanoparticles was successfully examined by dint of temperature sensing of the NaYF4:Er3+/Yb3+ shell, and it was found that an excitation-power-density-dependent temperature increase of up to several tens degrees can be achieved. All the experimental results suggested that the core-shell structure may be an excellent nanocalorifier candidate for advanced temperature-controllable PTT.

Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics.

Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures and their abundance in sewage sludge collected from wastewater treatment plants were analysed. Results indicated that ANAMMOX and DAMO bacteria co-existed in sewage sludge in different seasons and their abundance was positively correlated (P < 0.05). The high abundance of ANAMMOX and DAMO bacteria in autumn and winter indicated that these seasons were the preferred time to favour the growth of ANAMMOX and DAMO bacteria. The community structure of ANNAMOX and DAMO bacteria could also shift with seasonal changes. The "Candidatus Brocadia" genus of ANAMMOX bacteria was mainly recovered in spring and summer, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion. The redundancy analysis revealed that pH and nitrate were the most significant factors affecting community structures of these two groups (P < 0.01). This study reported the diversity of ANAMMOX and DAMO in wastewater treatment plants that may be the basis for new nitrogen removal technologies.

Recognition of the Duration and Prediction of Insect Prevalence of Stored Rough Rice Infested by the Red Flour Beetle (Tribolium castaneum Herbst) Using an Electronic Nose.

The purpose of this research is to explore the feasibility of applying an electronic nose for the intelligent monitoring of injurious insects in a stored grain environment. In this study, we employed an electronic nose to sample rough rice that contained three degrees of red flour beetle (Tribolium castaneum Herbst) infestation for different durations-light degree (LD), middle degree (MD), and heavy degree (HD)-and manually investigated the insect situation at the same time. Manual insect situation investigation shows that, in all three rice treatments, the insect amounts gradually decreased after infestation. When the insect population of stored rough rice was under 13 insects per 60 g of rough rice, the natural speed of decrease of the insect population became very slow and reached the best artificial insect killing period. Linear discriminant analysis (LDA) provided good performance for MD and HD insect harm duration identification, but performed poorly for LD insect harm duration identification. Both k-means clustering analysis (K-means) and fuzzy c-means analysis (FCM) effectively identified the insect harm duration for stored rough rice. The results from the back-propagation artificial neural network (BPNN) insect prevalence prediction for the three degrees of rough rice infestation demonstrated that the electronic nose could effectively predict insect prevalence in stored grain (fitting coefficients were larger than 0.89). The predictive ability was best for LD, second best for MD, and least accurate for HD. This experiment demonstrates the feasibility of electronic noses for detecting both the duration and prevalence of an insect infestation in stored grain and provides a reference for the intelligent monitoring of an insect infestation in stored grains.