244 research outputs found

    Automatic Classification of Bug Reports Based on Multiple Text Information and Reports' Intention

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    With the rapid growth of software scale and complexity, a large number of bug reports are submitted to the bug tracking system. In order to speed up defect repair, these reports need to be accurately classified so that they can be sent to the appropriate developers. However, the existing classification methods only use the text information of the bug report, which leads to their low performance. To solve the above problems, this paper proposes a new automatic classification method for bug reports. The innovation is that when categorizing bug reports, in addition to using the text information of the report, the intention of the report (i.e. suggestion or explanation) is also considered, thereby improving the performance of the classification. First, we collect bug reports from four ecosystems (Apache, Eclipse, Gentoo, Mozilla) and manually annotate them to construct an experimental data set. Then, we use Natural Language Processing technology to preprocess the data. On this basis, BERT and TF-IDF are used to extract the features of the intention and the multiple text information. Finally, the features are used to train the classifiers. The experimental result on five classifiers (including K-Nearest Neighbor, Naive Bayes, Logistic Regression, Support Vector Machine, and Random Forest) show that our proposed method achieves better performance and its F-Measure achieves from 87.3% to 95.5%

    Heavy Metals Transportation Between Sediment and Water Underdifferent Hydrodynamic Conditions

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Photoelectrochemical cell for simultaneous electricity generation and heavy metals recovery from wastewater

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    The feasibility of simultaneous recovery of heavy metals from wastewater (e.g., acid mining and electroplating) and production of electricity is demonstrated in a novel photoelectrochemical cell (PEC). The photoanode of the cell bears a nanoparticulate titania (TiO2) film capped with the block copolymer [poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol)] hole scavenger, which consumed photogenerated holes, while the photogenerated electrons transferred to a copper cathode reducing dissolved metal ions and produced electricity. Dissolved silver Ag+, copper Cu2+, hexavalent chromium as dichromate Cr2O72− and lead Pb2+ ions in a mixture (0.2 mM each) were removed at different rates, according to their reduction potentials. Reduced Ag+, Cu2+ and Pb2+ ions produced metal deposits on the cathode electrode which were mechanically recovered, while Cr2O72− reduced to the less toxic Cr3+ in solution. The cell produced a current density Jsc of 0.23 mA/cm2, an open circuit voltage Voc of 0.63 V and a maximum power density of 0.084 mW/cm2. A satisfactory performance of this PEC for the treatment of lead-acid battery wastewater was observed. The cathodic reduction of heavy metals was limited by the rate of electron-hole generation at the photoanode. The PEC performance decreased by 30% after 9 consecutive runs, caused by the photoanode progressive degradation

    Mechanism and experimental study on the photocatalytic performance of Ag/AgCl @ chiral TiO2 nanofibers photocatalyst: the impact of wastewater components

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    © 2014 Elsevier B.V.The effect of the water matrix components of a secondary effluent of a urban wastewater treatment plant on the photocatalytic activity of Ag/AgCl @ chiral TiO2 nanofibers and the undergoing reaction mechanisms were investigated. These effects were evaluated through the water components-induced changes on the net rate of hydroxyl radical (•OH) generation and modeled using a relative rate technique. Dissolved organic matter DOM (k=-2.8×108M-1s-1) scavenged reactive oxygen species, Cl- (k=-5.3×108M-1s-1) accelerated the transformation from Ag to AgCl (which is not photocatalytically active under visible-light irradiation), while Ca2+ at concentrations higher than 50mM (k=-1.3×109M-1s-1) induced aggregation of Ag/AgCl and thus all of them revealed inhibitory effects. In contrast, NO3- (k=6.9×108M-1s-1) and CO32- (k=3.7×108M-1s-1) improved the photocatalytic activity of Ag/AgCl slightly by improving the rate of HO• generation. Other ubiquitous secondary effluent components including SO42- (k=3.9×105M-1s-1), NH3+ (k=3.5×105M-1s-1) and Na+ (k=2.6×104M-1s-1) had negligible effects. 90% of 17-α-ethynylestradiol (EE2) spiked in the secondary effluent was removed within 12min, while the structure and size of Ag/AgCl @ chiral TiO2 nanofibers remained stable. This work may be helpful not only to uncover the photocatalytic mechanism of Ag/AgCl based photocatalyst but also to elucidate the transformation and transportation of Ag and AgCl in natural water

    Titanium Phosphate Nanoplates Modified With AgBr@Ag Nanoparticles: A Novel Heterostructured Photocatalyst With Significantly Enhanced Visible Light Responsive Activity

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    AgBr@Ag modified titanium phosphate composites were fabricated through a two-step approach. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The optical properties of the composites were characterized by using UV-vis diffuse reflectance spectroscopy. The photocatalytic activities of the composites were investigated on the degradation of Rhodamine B and ciprofloxacin under visible light irradiation. AgBr@Ag/titanium phosphate was determined to exhibit considerably higher photocatalytic activity than the corresponding individual components. The mechanism on the enhancement of the photocatalytic activity was proposed based on the results of photoluminescence spectra and photocurrent measurements. Furthermore, the possible photocatalytic mechanisms of organic compounds degradation were also proposed

    Harmine Ameliorates Cognitive Impairment by Inhibiting NLRP3 Inflammasome Activation and Enhancing the BDNF/TrkB Signaling Pathway in STZ-Induced Diabetic Rats

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    Diabetes mellitus (DM) is considered a risk factor for cognitive dysfunction. Harmine not only effectively improves the symptoms of DM but also provides neuroprotective effects in central nervous system diseases. However, whether harmine has an effect on diabetes-induced cognitive dysfunction and the underlying mechanisms remain unknown. In this study, the learning and memory abilities of rats were evaluated by the Morris water maze test. Changes in the nucleotide-binding oligomerization domain-containing protein (NOD)-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and brain-derived neurotrophic factor (BDNF)/TrkB signaling pathway were determined in both streptozotocin (STZ)-induced diabetic rats and high glucose (HG)-treated SH-SY5Y cells by western blotting and histochemistry. Herein, we found that harmine administration significantly ameliorated learning and memory impairment in diabetic rats. Further study showed that harmine inhibited NLRP3 inflammasome activation, as demonstrated by reduced NLRP3, ASC, cleaved caspase-1, IL-1β, and IL-18 levels, in the cortex of harmine-treated rats with DM. Harmine was observed to have similar beneficial effects in HG-treated neuronal cells. Moreover, we found that harmine treatment enhanced BDNF and phosphorylated TrkB levels in both the cortex of STZ-induced diabetic rats and HG-treated cells. These data indicate that harmine mitigates cognitive impairment by inhibiting NLRP3 inflammasome activation and enhancing the BDNF/TrkB signaling pathway. Thus, our findings suggest that harmine is a potential therapeutic drug for diabetes-induced cognitive dysfunction

    Seasonal, Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments from a Watershed Area in Gonghu Bay in Taihu Lake, China

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    Surface sediments from five stations within Gonghu Bay in Taihu Lake, China, were sampled for seasonal and spatial metal contamination analysis variations and ecological risks assessment from April 2009 to January 2010. The Contamination Factor (CF) and geo-accumulation index (Igeo) indicated that the sediments in Gonghu Bay ranged from unpolluted to moderately polluted, except for Cd. The one-way ANOVA analysis results showed that the Pb, Zn, Cr, and Cu concentrations were higher at station 3 (lake inlet) and the Cr, Pb, and Zn concentrations were significantly higher in the spring. Additionally, using BCR¡¦s sequential extraction, the results showed that the fractionated metals Zn and Cd were observed as bioavailable fractions in the sediments, which could have potential moderate mobility in the water system. There was a significant increase in the bioavailable form during winter. The ratio of secondary and primary phrase (RSP) decreased according to the order Zn > Cu > Ni > Pb > Cd > Cr. Finally, these results indicated that the sediments of Gonghu Bay were polluted by Cd, Zn, and Cu, which provides a scientific basis for effectively protecting sediments in watershed areas from long-term heavy metal accumulation

    Characterization of Antibiotics and Antibiotic Resistance Genes on an Ecological Farm System

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    There is a growing concern worldwide about the prevalence of antibiotics and antibiotic resistance genes (ARGs) on the farm. In this study, we investigated the distribution of seven antibiotics and ten ARGs in fresh and dried pig feces, in biogas slurry, and in grapeplanting soil from an ecological farm. Antibiotics including sulfamethazine, norfloxacin, ofloxacin, tetracycline, oxytetracycline, and chlortetracycline were detected in these samples (except for sulfamethoxazole) in dried feces. In general, antibiotics levels in samples were in the sequence: biogas slurry > fresh feces > soil or dried feces. Results of ecological risk assessments revealed that among the seven antibiotics chlortetracycline showed the highest ecological risk. Among the ten ARGs, sulI and tetO were the most prevalent on this ecological farm. There were positive correlations between certain ARGs and the corresponding antibiotics on this ecological farm. Therefore, continuous monitoring of antibiotics and their corresponding ARGs should be conducted in the agroecosystem near the concentrated animal farming operation systems

    Kinetic Cell-Based Morphological Screening: Prediction of Mechanism of Compound Action and Off-Target Effects

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    SummaryWe describe a cell-based kinetic profiling approach using impedance readout for monitoring the effect of small molecule compounds. This noninvasive readout allows continuous sampling of cellular responses to biologically active compounds and the ensuing kinetic profile provides information regarding the temporal interaction of compounds with cells. The utility of this approach was tested by screening a library containing FDA approved drugs, experimental compounds, and nature compounds. Compounds with similar activity produced similar impedance-based time-dependent cell response profiles (TCRPs). The compounds were clustered based on TCRP similarity. We identified novel mechanisms for existing drugs, confirmed previously reported calcium modulating activity for COX-2 inhibitor celecoxib, and identified an additional mechanism for the experimental compound monastrol. We also identified and characterized a new antimitotic agent. Our findings indicate that the TCRP approach provides predictive mechanistic information for small molecule compounds
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