As a broad-spectrum tetracycline antibiotic, the overuse of oxytetracycline (OTC) causes antibiotics residues in the environment and seriously threats to human health owing to effective antibacterial ...properties. Thus, it is particularly important to design a photoelectrochemical (PEC) aptasensor to detect OTC with excellent performance. Herein, we developed a selective and stable PEC aptasensor of OTC on the basis of Co3O4 nanoparticles (Co3O4 NPs)/graphitic carbon nitride (g-CN) heterojunction, used as PEC active materials. The Co3O4 NPs were successfully grown on the g-CN via grinding and calcining mixture of Co3O4 precursors and bulk g-CN. The Co3O4/g-CN heterojunction with improved light utilization and promoted electrons/holes separation capability can exhibit higher PEC signal than that of g-CN. In order to implement the purpose of specific recognition, OTC-aptamer was introduced into modified electrode to construct highly selective PEC aptasensor for OTC determination, which can possess wide linear range (0.01–500 nM) with low detection limit (3.5 pM, S/N = 3). This PEC aptasensor platform with excellent selectivity and high stability can provide a practical application in the field of water monitoring.
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•Co3O4-based photoactive materials was reported for detecting OTC.•The PEC aptasensor for OTC detection possessed low detection limit of 3.5 pM and excellent selectivity.•The PEC aptasensor has been applied in real water samples for OTC detection.
Angiogenesis is crucial for cancer initiation, development and metastasis. Identifying natural botanicals targeting angiogenesis has been paid much attention for drug discovery in recent years, with ...the advantage of increased safety. Isoliquiritigenin (ISL) is a dietary chalcone-type flavonoid with various anti-cancer activities. However, little is known about the anti-angiogenic activity of isoliquiritigenin and its underlying mechanisms. Herein, we found that ISL significantly inhibited the VEGF-induced proliferation of human umbilical vein endothelial cells (HUVECs) at non-toxic concentration. A series of angiogenesis processes including tube formation, invasion and migration abilities of HUVECs were also interrupted by ISL in vitro. Furthermore, ISL suppressed sprout formation from VEGF-treated aortic rings in an ex-vivo model. Molecular mechanisms study demonstrated that ISL could significantly inhibit VEGF expression in breast cancer cells via promoting HIF-1α (Hypoxia inducible factor-1α) proteasome degradation and directly interacted with VEGFR-2 to block its kinase activity. In vivo studies further showed that ISL administration could inhibit breast cancer growth and neoangiogenesis accompanying with suppressed VEGF/VEGFR-2 signaling, elevated apoptosis ratio and little toxicity effects. Molecular docking simulation indicated that ISL could stably form hydrogen bonds and aromatic interactions within the ATP-binding region of VEGFR-2. Taken together, our study shed light on the potential application of ISL as a novel natural inhibitor for cancer angiogenesis via the VEGF/VEGFR-2 pathway. Future studies of ISL for chemoprevention or chemosensitization against breast cancer are thus warranted.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A critical issue in intelligent building control is detecting energy consumption anomalies based on intelligent device status data. The building field is plagued by energy consumption anomalies ...caused by a number of factors, many of which are associated with one another in apparent temporal relationships. For the detection of abnormalities, most traditional detection methods rely solely on a single variable of energy consumption data and its time series changes. Therefore, they are unable to examine the correlation between the multiple characteristic factors that affect energy consumption anomalies and their relationship in time. The outcomes of anomaly detection are one-sided. To address the above problems, this paper proposes an anomaly detection method based on multivariate time series. Firstly, in order to extract the correlation between different feature variables affecting energy consumption, this paper introduces a graph convolutional network to build an anomaly detection framework. Secondly, as different feature variables have different influences on each other, the framework is enhanced by a graph attention mechanism so that time series features with higher influence on energy consumption are given more attention weights, resulting in better anomaly detection of building energy consumption. Finally, the effectiveness of this paper's method and existing methods for detecting energy consumption anomalies in smart buildings are compared using standard data sets. The experimental results show that the model has better detection accuracy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Because bacterial blight (BB) disease seriously affects the yield and quality of rice, breeding BB resistant rice is an important priority for plant breeders but the process is time-consuming. The ...feasibility of using terahertz imaging technology and near-infrared hyperspectral imaging technology to identify BB resistant seeds has therefore been studied. The two-dimensional (2D) spectral images and one-dimensional (1D) spectra provided by both imaging methods were used to build discriminant models based on a deep learning method, the convolutional neural network (CNN), and traditional machine learning methods, support vector machine (SVM), random forest (RF), and partial least squares discriminant analysis (PLS-DA). The highest classification accuracy was achieved by the discriminate model based on CNN using the terahertz absorption spectra. Confusion matrixes were pictured to show the identification details. The t-distributed stochastic neighbor embedding (t-SNE) method was used to visualize the process of CNN data processing. Terahertz imaging technology combined with CNN has great potential to quickly identify BB resistant rice seeds and is more accurate than using near-infrared hyperspectral imaging.
The study of forced and free vibration of a cylinder has long been isolated. The internal relationship between free vibration and forced vibration has rarely been investigated. In this paper, the ...relationship between the forced and free vibration of a cylinder was established. A series of numerical simulations of a cylinder undergoing forced oscillations at a wide range of vibration amplitudes and frequencies were carried out, with the flow solver viv-FOAM-SJTU developed based on the open-source platform OpenFOAM. Complex demodulation analysis was conducted to quantify the spatial-temporal phase relationship between the forces and the displacement of the cylinder. It was found that, at some particular oscillating amplitudes and frequencies, the phase angle switched between positive and negative values, which corresponds to a vortex mode transferring from the 2P mode to the 2PO mode. This distinct new mode “2PO” was closely related to the intermittent jumping between lower and upper branches of the amplitude responses of VIV. A prediction model was developed to obtain the VIV amplitude responses based on the numerical results of forced oscillation. The prediction results of three points located separately in the initial, upper, and lower branches of VIV agreed well with experimental measurements of an elastically mounted cylinder. This prediction model was thus expected to be suitable for predicting the response of VIV.
• Vacuolar (H⁺)-PPases (VPs), are key regulators of active proton (H⁺) transport across membranes using the energy generated from PPi hydrolysis. The VPs also play vital roles in plant responses to ...various abiotic stresses. Their functions in plant responses to pathogen infections are unknown.
• Here, we show that TaVP, a VP of wheat (Triticum aestivum) is important for wheat resistance to Chinese wheat mosaic virus (CWMV) infection. Furthermore, overexpression of TaVP in plants induces the activity of PPi hydrolysis, leading to plants cell death.
• A virus-derived small interfering RNA (vsiRNA-20) generated from CWMV RNA1 can regulate the mRNA accumulation of TaVP in wheat. The accumulation of vsiRNA-20 can suppress cell death induced by TaVP in a dosage-dependent manner. Moreover, we show that the accumulation of vsiRNA-20 can affect PPi hydrolysis and the concentration of H⁺ in CWMV-infected wheat cells to create a more favorable cellular environment for CWMV replication.
• We propose that vsiRNA-20 regulates TaVP expression to prevent cell death and to maintain a weak alkaline environment in cytoplasm to enhance CWMV infection in wheat. This finding may be used as a novel strategy to minimize virus pathogenicity and to develop new antiviral stratagems.
The objective of this study was to identify the areas that are most susceptible to landslide occurrence, and to find the key factors associated with landslides along Jinsha River and its tributaries ...close to Derong and Deqin County. Thirteen influencing factors, including (a) lithology, (b) slope angle, (c) slope aspect, (d) TWI, (e) curvature, (f) SPI, (g) STI, (h) topographic relief, (i) rainfall, (j) vegetation, (k) NDVI, (l) distance-to-river, (m) and distance-to-fault, were selected as the landslide conditioning factors in landslide susceptibility mapping. These factors were mainly obtained from the field survey, digital elevation model (DEM), and Landsat 4–5 imagery using ArcGIS software. A total of 40 landslides were identified in the study area from field survey and aerial photos’ interpretation. First, the frequency ratio (FR) method was used to clarify the relationship between the landslide occurrence and the influencing factors. Then, the principal component analysis (PCA) was used to eliminate multiple collinearities between the 13 influencing factors and to reduce the dimension of the influencing factors. Subsequently, the factors that were reselected using the PCA were introduced into the logistic regression analysis to produce the landslide susceptibility map. Finally, the receiver operating characteristic (ROC) curve was used to evaluate the accuracy of the logistic regression analysis model. The landslide susceptibility map was divided into the following five classes: very low, low, moderate, high, and very high. The results showed that the ratios of the areas of the five susceptibility classes were 23.14%, 22.49%, 18.00%, 19.08%, and 17.28%, respectively. And the prediction accuracy of the model was 83.4%. The results were also compared with the FR method (79.9%) and the AHP method (76.9%), which meant that the susceptibility model was reasonable. Finally, the key factors of the landslide occurrence were determined based on the above results. Consequently, this study could serve as an effective guide for further land use planning and for the implementation of development.
Rockfall source areas identification of high steep fractured rock slope is a challenging task for hazard mitigation. Considering this difficulty, a new method integrating discontinuity-based ...threshold slope angle and rockfall trajectory analyses is introduced in this study and applied to a railway bridge in China. First, abundant discontinuity data are collected by means of the modern unmanned aerial vehicle (UAV) digital photogrammetry technique. Then, a threshold slope angle used to delineate rockfall-prone areas is comprehensively determined by probabilistic kinematic and block theory analyses. Next, physically based rockfall trajectory simulation with consideration of mean block size is used to distinguish the hazard level of each release point. Finally, rockfall sources causing moderate and high risks to the train tunnel entrance at the base of high steep fractured rock slope are determined using a semiquantitative risk matrix approach. The final rockfall source map can provide a quantitative reference for hazard mitigation. At the end of this paper, some issues associated with the proposed approach are discussed, such as parameter importance analysis of threshold slope angle, comparison between the two probabilistic approaches and uncertainties in rockfall source areas identification.
•A method for rockfall sources identification of jointed rock slope is proposed.•This method integrates threshold slope angle and rockfall trajectory analyses.•Probabilistic approaches are developed to determine a final threshold slope angle.•A multiscanline method is presented to determine the volume of a launched block.•Trajectory dense and sparse areas are used to distinguish different hazard levels.
Lacustrine hydrocarbon source rocks with high quantity and quality of organic matter (OM) are developed within the third member of the Eocene Shahejie formation (Es3) in the Qikou Sag of the Huanghua ...Depression, Bohai Bay Basin, Eastern China. However, the paleolake environments associated with deposition of these rocks remain relatively undescribed, restricting our understanding of the biogeochemical processes which contributed to the development of excellent source rocks and inhibiting efforts for exploration of lacustrine hydrocarbon deposits. In this study, 18 core samples from the Es3 interval of Well Gangshen 4 in Qikou Sag were subject to a detailed analysis of bulk OM, biomarkers, molecular carbon isotopes, trace elements, and phosphorus (P) to investigate the environment and ecosystem of the ancient lake in which the rocks were deposited. High values of gammacerane index (av. 0.35) recorded in the samples reveals the oxic-anoxic stratification in the water column that persisted for the majority of the year due to the hot climate and great depth of the lake during this period. Meanwhile 13C-depleted hopanes (lower than −63.2‰) indicate an input of OM from chemoautotrophic and methanotrophic bacteria, supported by the production of CO2 and CH4 due to the anaerobic respiration of OM in the hypolimnion or sediments. The abundances of total organic carbon (TOC) relative to total P (TOC/P, mole ratio, av. 289.9) indicates the preferential release of P from sediments in an anoxic environment. However, the low (<2.0) Ni/Co and V/Cr ratios and moderate (av. 1.48) pristane/phytane (Pr/Ph) ratios suggest periodic oxidation of the hypolimnion, which may be a result of replenishment of oxygen during the short-term mixing of the water column driven by seasonal cooling and wind disturbance. Excess P was introduced into the epilimnion via mixing, which initiated high algal productivity after further stratification of the water column. Algal OM produced in this early stratification phase was crucial for the formation of excellent source rocks. The large variation of δ13C in TOC, n-alkanes, and isoprenoids reflects changes in CO2 concentrations or carbon isotopes in the photic zone, which may be attributable to increased inputs of terrestrial OM in response to a changing climate.
•Algae provided the crucial OM for developing source rocks in the Es3 member of the Qikou Sag, Bohai Bay Basin.•The development of anoxic bottom water promoted P release from sediments to the overlying water.•Massive input of internal P to the surface water fueled algal productivity.•Excessive input of terrestrial materials diluted OM abundance and deteriorated OM quality.
Objective:
The objective of this study is to identify patients with sepsis who are at a high risk of respiratory failure.
Methods:
Data of 1,738 patients with sepsis admitted to Dongyang People’s ...Hospital from June 2013 to May 2023 were collected, including the age at admission, blood indicators, and physiological indicators. Independent risk factors for respiratory failure during hospitalization in the modeling population were analyzed to establish a nomogram. The area under the receiver operating characteristic curve (AUC) was used to evaluate the discriminative ability, the GiViTI calibration graph was used to evaluate the calibration, and the decline curve analysis (DCA) curve was used to evaluate and predict the clinical validity. The model was compared with the Sequential Organ Failure Assessment (SOFA) score, the National Early Warning Score (NEWS) system, and the ensemble model using the validation population.
Results:
Ten independent risk factors for respiratory failure in patients with sepsis were included in the final logistic model. The AUC values of the prediction model in the modeling population and validation population were 0.792 and 0.807, respectively, both with good fit between the predicted possibility and the observed event. The DCA curves were far away from the two extreme curves, indicating good clinical benefits. Based on the AUC values in the validation population, this model showed higher discrimination power than the SOFA score (AUC: 0.682;
p
< 0.001) and NEWS (AUC: 0.520;
p
< 0.001), and it was comparable to the ensemble model (AUC: 0.758;
p
= 0.180).
Conclusion:
Our model had good performance in predicting the risk of respiratory failure in patients with sepsis within 48 h following admission.
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