A novel halophilic bacterium capable of heterotrophic nitrification-aerobic denitrification was isolated from marine sediments and identified as Vibrio diabolicus SF16. It had ability to remove ...91.82% of NH4(+)-N (119.77 mg/L) and 99.71% of NO3(-)-N (136.43 mg/L). The nitrogen balance showed that 35.83% of initial NH4(+)-N (119.77 mg/L) was changed to intracellular nitrogen, and 53.98% of the initial NH4(+)-N was converted to gaseous denitrification products. The existence of napA gene further proved the aerobic denitrification ability of strain SF16. The optimum culture conditions were salinity 1-5%, sodium acetate as carbon source, C/N 10, and pH 7.5-9.5. When an aerated biological filter system inoculated with strain SF16 was employed to treat saline wastewater, the average removal efficiency of NH4(+)-N and TN reached 97.14% and 73.92%, respectively, indicating great potential of strain SF16 for future full-scale applications.
Deep learning has become the most widely used approach for cardiac image segmentation in recent years. In this paper, we provide a review of over 100 cardiac image segmentation papers using deep ...learning, which covers common imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound and major anatomical structures of interest (ventricles, atria, and vessels). In addition, a summary of publicly available cardiac image datasets and code repositories are included to provide a base for encouraging reproducible research. Finally, we discuss the challenges and limitations with current deep learning-based approaches (scarcity of labels, model generalizability across different domains, interpretability) and suggest potential directions for future research.
The prediction of gait motion intention is essential for achieving intuitive control of assistive devices and diagnosing gait disorders. To reduce the cost associated with using multimodal signals ...and signal processing, we proposed a novel method that integrates machine learning with musculoskeletal modelling techniques for the prediction of time-series joint angles, using only kinematic signals. Additionally, we hypothesised that a stacked long short-term memory (LSTM) neural network architecture can perform the task without relying on any ahead-of-motion features typically provided by electromyography signals. Optical cameras and inertial measurement unit (IMU) sensors were used to track level gait kinematics. Joint angles were modelled using the musculoskeletal model. The optimal LSTM architecture in fulfilling the prediction task was determined. Joint angle predictions were performed for joints on the sagittal plane, benefiting from joint angle modelling using signals from optical cameras and IMU sensors. Our proposed method predicted the upcoming joint angles in the prediction time of 10 ms, with an averaged root mean square error of 5.3° and a coefficient of determination of 0.81. Moreover, in support of our hypothesis, the recurrent stacked LSTM network demonstrated its ability to predict intended motion accurately and efficiently in gait, outperforming two other neural network architectures: a feedforward MLP and a hybrid LSTM-MLP. The method paves the way for the development of a cost-effective, single-modal control system for assistive devices in gait rehabilitation.
Motion analysis is used in computer vision to understand the behaviour of moving objects in sequences of images. Optimising the interpretation of dynamic biological systems requires accurate and ...precise motion tracking as well as efficient representations of high-dimensional motion trajectories so that these can be used for prediction tasks. Here we use image sequences of the heart, acquired using cardiac magnetic resonance imaging, to create time-resolved three-dimensional segmentations using a fully convolutional network trained on anatomical shape priors. This dense motion model formed the input to a supervised denoising autoencoder (4D
), which is a hybrid network consisting of an autoencoder that learns a task-specific latent code representation trained on observed outcome data, yielding a latent representation optimised for survival prediction. To handle right-censored survival outcomes, our network used a Cox partial likelihood loss function. In a study of 302 patients the predictive accuracy (quantified by Harrell's C-index) was significantly higher (p = .0012) for our model C=0.75 (95% CI: 0.70 - 0.79) than the human benchmark of C=0.59 (95% CI: 0.53 - 0.65). This work demonstrates how a complex computer vision task using high-dimensional medical image data can efficiently predict human survival.
Calcium–modified water hyacinth biochar (WHCBC–400 and WHCBC–600) was prepared using water hyacinth as raw material and calcium chloride as modifier at two pyrolysis temperatures of 400 °C and ...600 °C. The effectiveness for removal of malathion, a typical organophosphorus pesticide from water were comparatively examined by the prepared adsorbents. The impacts of the pyrolysis temperature on performance of the biochar and adsorption behavior of malathion on the modified biochar were systematically studied by surface analysis, removal efficiency tests under different solution conditions, as well as data simulations. The adsorption mechanisms and reusability of the modified biochar were also investigated and experimented, respectively. The results indicated that the WHCBC–600 had a larger specific surface area and pore volume than the WHCBC–400, while WHCBC–400 had a greater polarity and hydrophilicity. Both of the two prepared biochars followed pseudo–second–order kinetics and their adsorption isotherms conformed to the Sips model. The maximum adsorption capacities of WHCBC–400 and WHCBC–600 were 128 mg/g and 32.7 mg/g, respectively. It was found that the adsorption of malathion by the biochars were dominated by chemisorption. Diffusion at the liquid film was the rate–limiting step in the adsorption process. The difference in the form of the calcium loadings, polarity of biochar, and the rate–limiting step of adsorption were important factors affecting the adsorption capacity of the biochar. In comparison, the specific surface area and pore volume of the prepared absorbents had less significant effects on the adsorption capacity. The main adsorption mechanism of the two modified biochars was surface complexation. In addition, the solution pH and coexisting material had little effect on the adsorption of malathion by WHCBC–400 and WHCBC–600. Both of the modified biochar had good regeneration performance. The study provided a new adsorbent for the removal of malathion from water.
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•Low temperature biochar had greater polarity.•High temperature biochar had larger specific surface area and pore volume.•WHCBC–400 (128 mg/g) had higher adsorption capacity than WHCBC–600 (32.7 mg/g).•Polarity and liquid film diffusion were affecting the adsorption effect of biochar.•The main adsorption mechanism was surface complexation.
Increasing resistance by malaria parasites to currently used antimalarials across the developing world warrants timely detection and classification so that appropriate drug combinations can be ...administered before clinical complications arise. However, this is often challenged by low levels of infection (referred to as parasitemia) and presence of predominantly young parasitic forms in the patients' peripheral blood. Herein, we developed a simple, inexpensive and portable image-based cytometer that detects and numerically counts Plasmodium falciparum infected red blood cells (iRBCs) from Giemsa-stained smears derived from infected blood. Our cytometer is able to classify all parasitic subpopulations by quantifying the area occupied by the parasites within iRBCs, with high specificity, sensitivity and negligible false positives (~ 0.0025%). Moreover, we demonstrate the application of our image-based cytometer in testing anti-malarial efficacy against a commercial flow cytometer and demonstrate comparable results between the two methods. Collectively, these results highlight the possibility to use our image-based cytometer as a cheap, rapid and accurate alternative for antimalarial testing without compromising on efficiency and minimal processing time. With appropriate filters applied into the algorithm, to rule out leukocytes and reticulocytes, our cytometer may also be used for field diagnosis of malaria.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•The unique waffle structure realized the collaborative mechanisms of absorption and scattering towards electromagnetic waves.•The RCS reduction below −10 dB was achieved for WSC, and ...the peak reached to −30 dB.•The dielectric loss is the main cause of absorption for waffle structured composite.•The waffle structure formed by one-step knitting process facilitates the continuous large-scale manufacture.
A radar absorbing material named waffle structured composite (WSC) was proposed based on the periodic structure element formed by one-step double-sided knitting process with the advantage of continuous manufacture. The unique waffle structured pattern shaped by the knitted loops achieved the integration of structure and function. By realizing the collaborative mechanisms of absorption and scattering, the radar cross section (RCS) below −10 dB was achieved in the range of 6–8 GHz and 12–18 GHz towards the wale and course directions, respectively, and RCS reduction peak reaches to −30 dB. Through the S-parameter analysis and electromagnetic simulation, it can be revealed that the low-frequency RCS reduction in the wale direction was mainly dominated by the absorption mechanism, and the high-frequency RCS reduction in the course direction was led by the scattering mechanism. Furthermore, to further explore the scattering and absorption mechanism, phase difference, dielectric loss and magnetic loss were investigated in details. It was verified that the absorption of WSC is mainly originated from dielectric loss with slight magnetic loss, and Debye relaxation plays the important role in dielectric loss. The WSC proposed in this paper is equipped with characteristics of good RCS reduction and continuous large-scale manufacture, which is promising in practical engineering application of radar stealth.
Prechlorination is commonly used to minimize operational problems associated with biological growth as well as taste and odor control during drinking water treatment. However, prechlorination can ...also oxidise micropollutants into intermediate byproducts. This could impose profound effects on the safety of the finished water if the transformed byproducts are more toxic and less removable. This study investigated the effect of prechlorination on decomposition and subsequent removal of the four organophosphorus pesticides (OPPs): chlorpyrifos, diazinon, malathion and tolclofos-methyl using a simulated conventional water treatment process of powdered activated carbon assisted coagulation-sedimentation-filtration (PAC-CSF) and postchlorination. It was found that, following prechlorination, not only did the percentage of OPPs oxidation vary significantly, but also the concentration of transformed oxons, which are more toxic than their parent compounds, increased as the major identified oxidation byproducts in water. Removal of these oxons proved to be more difficult by the PAC-CSF than their parent OPPs, because they are more water soluble and more hydrophilic. Both the OPP oxidation and oxon formation increased with chlorine dose during prechlorination. Meanwhile, the continuing chlorination of OPPs by residual free chlorine during PAC-CSF further complicated the pesticide removal processes, generally resulting in a gradually increased formation of oxons. Moreover, in the final treatment stage of postchlorination, the more chlorine-reactive pesticides, malathion and diazinon, were completely oxidised and the formation of corresponding oxons was increased with the prechlorine dose. In contrast, a certain amount of the less chlorine-reactive pesticide tolclofos-methyl still remained in solution after postchlorination, accompanied by an increased formation of tolclofos-methyl oxon with prechlorine dose. Since the oxons are resistant to further oxidation and less adsorbable during the PAC-CSF process, the gross removal of these pesticides and their oxons decreased with increase of the prechlorine dose. This led to an accumulation of the more toxic oxons in the finished water, especially at higher chlorine doses during prechlorination. The significance of this work is the demonstration that, under circumstances where prechlorination is used and source water contains traces of OPPs, alternative practices should be prioritized to avoid the potential risks involved in consumption of the treated water.
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•Amount of toxic oxons in finished water increased with prechlorine dose.•Gross removal of OPPs and their toxic oxons decreased with prechlorine dose.•The more chlorine-reactive and less absorbable OPPs have smaller gross removal.•Molar ratio of OPPs to oxons varies with OPP species, but not with chlorine dose.
The interfacial interactions between the OPE molecules and CNTs.
•Oxygen-containing groups on CNTs change the sorption property for OPEs.•Molecular configuration of OPEs has insignificant impact on ...their sorption.•Hydrophobic, π–π EDA and Brønsted acid–base interaction occurred between the CNTs and OPEs.
Insights from the molecular-level mechanism of sorption of organophosphate esters (OPEs) on carbon nanotubes (CNTs) can further our understanding of the fate and transport of OPEs in the environment. The motivation for our study was to explore the sorption process of OPEs on multi-walled CNTs (MWCNTs), single-walled CNTs (SWCNTs) and their oxidized counterparts (O-MWCNTs and O-SWCNTs), and its molecular mechanism over a wide concentration range. The sorption isotherm results revealed that the hydrophobicity of OPEs dominated their affinities on a given CNT and the π–π electron donor–acceptor (EDA) interaction also played an important role in the sorption of aromatic OPEs. This π–π EDA interaction, verified with Raman and FT-IR spectroscopy, could restrict the radial vibration of SWCNTs and affect the deformation vibration γ(CH) bands of OPE molecules. The OPE surface coverage on CNTs, estimated using the nonlinear Dubinin–Ashtakhov model, indicated that the oxygen-containing functional groups on CNTs could interact with water molecules by H-bonding, resulting in a decrease in effective sorption sites. In addition, FTIR analysis also confirmed the occurrence of Brønsted acid–base interactions between OPEs and surface OH groups of SWCNTs. Our results should provide mechanistic insights into the sorption mechanism of OPE contaminants on CNTs.
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