Search

Background: Diffusion tensor imaging (DTI) is a promising technique for non‐invasively investigating the myocardial fiber structures of human heart. However, low signal‐to‐noise ratio (SNR) has been a major limit of cardiac DTI to prevent us from detecting myocardium structure accurately. Therefore, it is important to remove the effect of noise on diffusion weighted (DW) images. Purpose: Although the conventional and deep learning‐based denoising methods have shown the potential to deal with effectively the noise in DW images, most of them are redundant information dependent or require the noise‐free images as golden standard. In addition, the existed DW image denoising methods often suffer from problems of over‐smoothing. To address these issues, we propose a self‐supervised learning model, structural similarity based convolutional neural network with edge‐weighted loss (SSECNN), to remove the noise effectively in cardiac DTI. Methods: Considering that the DW images acquired along different diffusion directions have structural similarity, and the noise in these DW images is independent and identically distributed, the structural similarity‐based matching algorithm is proposed to search for the most similar DW images. Such similar noisy DW image pairs are then used as the input and target of the denoising network SSECNN, which consists of several convolutional and residual blocks. Through the self‐supervised training with these image pairs, the network can restore the clean DW images and retain the correlations between the denoised DW images along different directions. To avoid the over‐smoothing problem, we design a novel edge‐weighted loss which enables the network to adaptively adjust the loss weights with iterations and therefore to improve the detail preserve ability of the model. To verify the superiority of the proposed method, comparisons with state‐of‐the‐art (SOTA) denoising methods are performed on both synthetic and real acquired DTI datasets. Results: Experimental results show that SSECNN can effectively reduce the noise in the DW images while preserving detailed texture and edge information and therefore achieve better performance in DTI reconstruction. For synthetic dataset, compared to the SOTA method, the root mean square error (RMSE), peak signal‐to‐noise ratio (PSNR), and structure similarity index measure (SSIM) between the denoised DW images obtained with SSECNN and noise‐free DW images are improved by 6.94%, 1.98%, and 0.76% respectively when the noise level is 10%. As for the acquired cardiac DTI dataset, the SSECNN method could significantly improve SNR and contrast to noise ratio (CNR) of cardiac DW images and achieve more regular helix angle (HA) and transverse angle (TA) maps. The ablation experimental results validate that using the structure similarity‐based method to search the similar DW image pairs yield the smallest loss, and with the help of the edge‐weighted loss, the denoised DW images and diffusion metric maps can preserve more details. Conclusions: The proposed SSECNN method can fully explore the similarity between the DW images along different diffusion directions. Using such similarity and an edge‐weighted loss enable us to denoise cardiac DTI effectively in a self‐supervised manner. Our method can overcome the redundancy information dependence and over‐smoothing problem of the SOTA methods. [ABSTRACT FROM AUTHOR]

Although the existing cardiac diffusion tensor imaging (DTI) denoising methods have achieved promising results, most of them are dependent on the number of diffusion gradient directions, noise distributions, and noise levels. To address these issues, we propose a novel self-supervised cardiac DTI denoising network, Node2Node, which firstly expresses the diffusion-weighted (DW) image volumes along different directions as a graph, then the graph framelet transform (GFT) is implemented to map the DW signals into the GFT coefficients at different spectral bands, allowing us to accurately match the DW image pairs. After that, using the matched image pairs as input and target, a ResNet-like network is used to denoise in a self-supervised manner. In addition, a novel edge-aware loss based on pooling operation is proposed to retain the edge. Through comparison with several state-of-the-art methods on synthetic, ex vivo porcine, and in vivo human cardiac DTI datasets, we showed that the root mean square error (RMSE) of DW images and the average angular error (AAE) of fiber orientations obtained using Node2Node are the smallest, improved by 47.5% and 23.7%, respectively, on the synthetic dataset, demonstrating that Node2Node is not sensitive to the properties of the dataset. [ABSTRACT FROM AUTHOR]

Fuel cells, as one of the most promising technologies in sustainable energy conversion systems, hold great expectations for commercial applications. Cathode oxygen reduction reaction (ORR) kinetics of fuel cells are very slow and require a large overpotential to make the reaction occur, which greatly limits the energy output of fuel cells. Therefore, designing and preparing a highly active and stable ORR catalyst has become a great challenge. Herein, recent advances in platinum‐based and platinum‐free materials in metal‐based catalysts are focused on, including structural properties, synthesis methods, performance characterization, and catalytic mechanisms. Although platinum‐based precious metal catalysts have excellent performance, high prices limit the scale of commercial fuel cells. Nonprecious metal catalysts (e.g., transition metal nitrogen‐doped carbon‐based catalysts (M‐N/C), transition metal compounds (transition metal oxides—TMOs, transition metal carbides—TMCs, transition metal nitrides/transition metal oxynitrides—TMNs/TMNOs), layered double hydroxides—LDHs) completely eliminate dependence on precious metals and exhibit excellent ORR catalytic activity and stability. Finally, the ideas for future design and preparation of new ORR catalysts and challenges in the future of research work are discussed. [ABSTRACT FROM AUTHOR]

Surface modified with nano-ZnO LNCM power has been successfully prepared using facile low-temperature solid-state route. The experimental results show that the reaction temperature has a great influence on the structure of coating layer. ZnO@LNCM-400 shows the best electrochemical performance, which has lesser capacity loss than the others. It shows superior performance with higher capacity (216.6 mAh g−1) and significantly improved cycling stability (maintaining 97.28% of its initial discharge capacity after 100 cycles). Moreover, it has excellent rate performance especially at elevated performance, which is probably due to the faster Li+ transportation by the nano-ZnO layer. The ZnO-coated LNCM electrode showed less capacity loss about 15.8%, even at 55 °C after 100 cycles. We found that ZnO played an important role in reducing the HF content in the electrolyte solution and improving the electrical conductivity of the material, which is beneficial to the electrochemical performance of material. [ABSTRACT FROM AUTHOR]

The beneficial recycle of drinking water treatment residue (DWTR) in environmental remediation has been demonstrated in many reports. However, the lack of information concerning the potential toxicity of dewatered DWTR hinders its widespread use. The present study examined the ecotoxicity of dewatered aluminum (Al) and iron (Fe) DWTR leachates to a green alga,Chlorella vulgaris. Data from the variations of cell density and chlorophyll a content suggested that algal growth in DWTR leachates was inhibited. The algal cellular oxidation stress was initially induced but completely eliminated within 72 h by antioxidant enzymes. The expression of three photosynthesis-related algae genes (psaB,psbC, andrbcL) also temporarily decreased (within 72 h). Moreover, the algal cells showed intact cytomembranes after exposure to DWTR leachates. Further investigation confirmed that inhibition of algal growth was due to DWTR-induced phosphorus (P) deficiency in growth medium, rather than potentially toxic contaminants (e.g. copper and Al) contained in DWTR. Interestingly, the leachates could potentially promote algal growth via increasing the supply of new components (e.g. calcium, kalium, magnesium, and ammonia nitrogen) from DWTR. In summary, based on the algae toxicity test, the dewatered Fe/Al DWTR was nontoxic and its environment recycling does not represent an ecotoxicological risk to algae. [ABSTRACT FROM PUBLISHER]

The genetic element 'Mona' has been shown previously to be associated with resistance to demethylation inhibitors (DMIs) in Monilinia fructicola. In this study, the promoter activity of the 'Mona' element was demonstrated genetically and the activity was narrowed down to a 20-bp active region through a series of deletions. 'Mona' knockout transformants (ΔMona) were generated from DMI-resistant isolate Bmpc7, and EC50 values and expression of the MfCYP51 gene were found to be reduced in transformants compared with the parental isolate. When the 'Mona' element was inserted into the upstream region of the MfCYP51 gene of the DMI-sensitive isolate HG3, the EC50 values and expression of the MfCYP51 gene increased in the transformants compared with the parental sensitive isolate. These results indicate that the 'Mona' element determines the DMI fungicide resistance through the up-regulation of the expression of the downstream MfCYP51 gene. No fitness penalty was observed in knockout and insertion transformants, i.e. transformants showed similar mycelial growth rate, sporulation and ability to cause lesions on fruit compared with their parental isolates, suggesting that the 'Mona' element does not affect basal life activities. [ABSTRACT FROM AUTHOR]

The beneficial recycling of drinking water treatment residue (DWTR) for environmental remediation has attracted growing attention, and oxygen-limited heat treatment has a high potential to improve DWTR adsorptive properties for better recycling. In this study, physicochemical property variation induced by oxygen-limited heat treatment was evaluated for six DWTR obtained from different drinking water treatment plants in Australia, China, and Ireland. The results showed that the changes in many properties, typically amorphous Al and Fe contents, mesopores, specific surface area (SSA), and total pore volume (TPV) of DWTR after treatment, showed inconsistent trends. The treatment also led to the varied lability of metals and As in DWTR although the human bioaccessibility and plant bioavailability of most metals decreased. Accordingly, oxygen-limited heat treatment may not be applicable for all DWTR improvement. Based on these findings, pre-screening processes to evaluate adsorptive properties and metal and metalloid lability were determined. Oxygen-limited heat treatment was more applicable to DWTR with neutral and weak alkaline properties (pH 7.0–7.8), low humic acid (HA) content (<2.09 mg g −1 ), and high amorphous Fe and HA ratio (>5.93), as well as with relatively high amorphous Al and HA ratio and high humin content. [ABSTRACT FROM AUTHOR]

Drinking water treatment residuals (WTRs) have a potential to realize eutrophication control objectives by reducing the internal phosphorus (P) load of lake sediments. Information regarding the ecological risk of dewatered WTR reuse in aquatic environments is generally lacking, however. In this study, we analyzed the eco-toxicity of leachates from sediments with or without dewatered WTRs toward algae Chlorella vulgaris via algal growth inhibition testing with algal cell density, chlorophyll content, malondialdehyde content, antioxidant enzyme superoxide dismutase activity, and subcellular structure indices. The results suggested that leachates from sediments unanimously inhibited algal growth, with or without the addition of different WTR doses (10% or 50% of the sediment in dry weight) at different pH values (8–9), as well as from sediments treated for different durations (10 or 180 days). The inhibition was primarily the result of P deficiency in the leachates owing to WTR P adsorption, however, our results suggest that the dewatered WTRs were considered as a favorable potential material for internal P loading control in lake restoration projects, as it shows acceptably low risk toward aquatic plants. [ABSTRACT FROM AUTHOR]

Using panel data on housing construction, this article examines the crowding-out effects of affordable and unaffordable housing in China from 1999 to 2010. Applying a dynamic panel model allows us to examine the dynamic interactions between affordable and unaffordable housing constructions when controlling for region-specific fixed and time-specific effects. We analyse whether affordable (unaffordable) housing construction has changed in response to the past and contemporaneous construction of unaffordable (affordable) housing. Our empirical results reveal an asymmetric crowding-out pattern between affordable and unaffordable housing. We also observe that when urbanization rate is lower than 57.39%, unaffordable housing construction crowds out affordable housing construction. Moreover, the crowding-out effect of unaffordable housing on affordable housing decreases with rising urbanization rates. [ABSTRACT FROM AUTHOR]

Algal cultivation is a potential candidate for CO2 mitigation. CO2 plays important roles in mass cultivation of algae, including supplying carbon source and adjusting medium pH. To assess the possibility of using edible cyanobacterium Nostoc flagelliforme as carbon storage device, the growth characteristics of N. flagelliforme batch cultured under elevated CO2 concentrations (0, 2.5, 5, 20, and 40%) were investigated in this study. Results showed that the net photosynthetic rate, efficiency and carbon sequestration rate at 20% CO2 were increased at a maximum of 121 μmol O2 (mg chl a)−1 h−1 8.40% and 0.17 g CO2 L−1 day−1, and increased by 0.42, 1.03 and 1.13 folds compared with that of the control, respectively. Higher CO2 concentration resulted in the declines in photosynthetic rate, efficiency and carbon sequestration rate because of medium pH reduction. Accordingly, the dry cell weight, amount of exopolysaccharides and protein content of N. flagelliforme cells at 20% CO2 were obtained at a maximum of 1.45 g L−1, 54.98 mg L−1 and 57.75%, increased by 0.93, 0.29 and 0.8 folds compared with that of the control, respectively. These results provided important information for CO2 mitigation by N. flagelliforme and would shed more light on elucidating the mechanisms of CO2 tolerance in cyanobacterium. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel multifunctional Cd-viologen coordination polymer has been synthesized. • The photochromic mechanism of 1 was investigated experimentally and theoretically. • Compound 1 has the ability to detect amines. • The photo-controlled luminescence properties of 1 has been explored. A novel coordination polymer, named [Cd(HCOO)(pbpy) 0.5 (bdc)(H 2 O)]·3H 2 O (1), based on a new flexible viologen ligand 1,1′-[1,4-phenylenebis(methylene)]-bis(4,4′-bipyridinium) dichloride (pbpy·2Cl), Cd(NO 3) 2 ·4H 2 O and terephthalic acid (H 2 bdc) was synthesized. Compound 1 has good photosensitive activity and can also respond to sunlight at room temperature. And using time-dependent density functional theory (TDDFT) to study the discoloration mechanism of compound 1. Attractively, 1 has the ability to select and detect amines due to the electron-deficient properties of pbpy·2Cl. In addition, photocontrolled luminescence properties of 1 , during the coloration-decoloration process, has been researched. [ABSTRACT FROM AUTHOR]

Abstract: Microwave-H2O2 (MW-H2O2) technology, one of the environmental treatment methods, was reported to usually prefer acidic and neutral circumstances in substrates’ degradation. In this work, degradation of Rhodamine B (RhB) and methylene blue (MB) in MW-H2O2 system was found to be very competitive at extreme alkaline pH. This is a new finding and few studies have noticed it yet. Through radical species’ tests and control experiments, degradation of RhB at strong alkaline pH in MW-H2O2 system was considered to mainly undergo oxygen oxidation, and the enhancement of MW thermal effect. This work provided a possible effective way to study the degradation at highly alkaline circumstances, and might promote the development of MW-H2O2 technology in alkaline wastewater treatment. [Copyright &y& Elsevier]

Due to the broad application prospect, flexible and transparent electronic device has been widely used in portable wearable devices, energy storage smart window and other fields, which owns many advantages such as portable, foldable, small-quality, low-cost, good transparency, high performance and so on. All these electronic devices are inseparable from the support of energy storage device. Energy storage device, like lithium-ion battery and super capacitor, also require strict flexibility and transparency as the energy supply equipment of electronic devices. Here, we demonstrate the development and applications of flexible and transparent lithium-ion battery and super capacitor. In particular, carbon nanomaterials are widely used in flexible and transparent electronic device, due to their excellent optical and electrical properties and good mechanical properties. For example, carbon nanotubes with high electrical conductivity and low density have been widely reported by researchers. Otherwise, graphene as an emerging two-dimensional material with electrical conductivity and carrier mobility attracts comparatively more attention than that of other carbon nanomaterials. Substantial effort has been put on the research for graphene-based energy storage system by researchers from all over the world. But, there is still a long way to accomplish this goal of improving the performance for stretchable and transparent electronic device due to the existing technical conditions. [ABSTRACT FROM AUTHOR]

Drinking water treatment residue (DWTR), a byproduct generated during potable water production, exhibits a high potential for recycling to control eutrophication. However, this beneficial recycling is hampered by unclear metal/metalloid pollution risks related to DWTR. In this study, the pollution risks of Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn due to DWTR application were first evaluated for lake water based on human health risk assessment models and comparison of regulatory standards. The risks of DWTR were also evaluated for sediments on the basis of toxicity characteristics leaching procedure and fractionation in relation to risk assessment code. Variations in the biological behaviors of metal/metalloid in sediments caused by DWTR were assessed using Chironomus plumosus larvae and Hydrilla verticillata. Kinetic luminescent bacteria test (using Aliivibrio fischeri) was conducted to analyze the possibility of acute and chronic detrimental effects of sediment with DWTR application. According to the obtained results, we identify a potential undesirable effect of DWTR related to Fe and Mn (typically under anaerobic conditions); roughly present a dosage threshold calculation model; and recommend a procedure for DWTR prescreening to ensure safe application. Overall, managed DWTR application is necessary for successful eutrophication control. [ABSTRACT FROM AUTHOR]

As a by-product generated increasingly during potable water production, drinking water treatment residue (DWTR) recycling for environmental remediation can lead to a win–win situation. In this study, oxygen-limited heat treatment was applied to DWTR, attempting to tune the properties of DWTR for better recycling. The results showed that after the treatment, N 2 sorption capacity of DWTR was enhanced significantly: the specific surface area (SSA) and total pore volume (TPV) increased from 72.7 to 148–184 m 2 g −1 and from 0.0746 to 0.189–0.201 cm 3 g −1 , respectively. The treatment also relatively increased the amorphous Al/Fe contents in DWTR although Al/Fe aging and transformation from hydroxides to oxides with high stability were observed. The retained organic matter (OM) was dominant in humin, with higher aromaticity and lower aliphaticity as the treatment temperature increased. Further analysis suggested that aromaticity increase induced higher SSA, the combined effect of OM aromaticity increase, OM loss (e.g. C in COO − ), and metal oxides formation resulted in larger TPV, OM inhibited Al/Fe aging, while Al/Fe oxides formation in turn enhanced OM aromaticity. Additionally, the maximum Hg adsorption capacity of DWTR treated at 200–400 °C (estimated by Langmuir model) increased from 53.5 to 69.9–147 mg g −1 , and the lability of heavy metals (e.g. Cu) in DWTR tended to decrease after treatment. The overall results demonstrated that oxygen-limited heat treatment sequestrated C, making DWTR be a more reliable adsorbent. [ABSTRACT FROM AUTHOR]

This study proposes the use of an aluminum-based drinking water treatment residue (DWTR) to adsorb ferrocyanide. The batch tests and chemical characterization results showed that ferrocyanide adsorption increased as the pH, ion strength, and the solid and solution ratio decreased, and as the initial ferrocyanide concentration increased. The pseudo-first (R 2 = 0.906) and pseudo-second-order (R 2 = 0.966) kinetic models well described the adsorption kinetics, and the adsorption isotherm was also well fittted by Langmuir (R 2 = 0.989) and Freundlich (R 2 = 0.989) models. The calculated initial ferrocyanide adsorption rate by the pseudo-second-order kinetic model was 0.0190 mg-CN g−1 h−1, and the estimated maximum adsorption capacity determined by the Langmuir model was 20.9 mg-CN g−1. The main structure and elemental distributions showed nearly no change in DWTR after adsorption. Adsorption involved electrostatic interactions and ligand exchanges with Al in DWTR, as evidenced by the 1.40 eV increase in the Al binding energy after adsorption. Furthermore, ferrocyanide adsorption had a dual effect on the DWTR porosity (including both increase and decrease effect), resulting in a slight increase in the specific surface area and total pore volume of DWTR after adsorption. This dual effect was likely related to Fe present in ferrocyanide, which introduced new vacant sites on DWTR. Overall, recycled DWTR is a promising potential adsorbent for ferrocyanide. • This study verified that alum-based DWTR had capability to adsorb iron cyanide. • The adsorption under various conditions was comprehensively investigated. • The adsorption was occurred based on electrostatic adsorption and ligand exchange. • The adsorption had dual effect on DWTR porosities at different pore diameters. [ABSTRACT FROM AUTHOR]

Highlights • H2 could inhibit oxidative stress, restrain the loss of MMP and protect the mitochondrial function during the process of OGD/R. • The potential protection mechanism that H2 could increase cell viability and reduce the neuronal apoptosis after OGD/R injury may closely related to the enhancement of mitochondrial function via mitophagy mediated by PINK1/Parkin signaling pathway. Abstract Cerebral ischemia/reperfusion injury (IRI) is a serious complication during the treatment of stroke patients with very few effective clinical treatment. Hydrogen (H2) can protect mitochondria function and have favorable therapeutic effects on cerebral IRI. Mitophagy plays an important role in eliminating damaged or dysfunctional mitochondria and maintaining mitochondria homeostasis. However, whether the protection of H2 on cerebral IRI is via regulating mitophagy is still unknown. In this study, OGD/R damaged hippocampal neurons were used to mimic cerebral IRI in vivo and we detected the effect of H2, Rap (autophagy activator) and 3-MA (autophagy inhibitor) on OGD/R neurons. The results of MTT indicated that H2 and RAP could increase cell viability after OGD/R treatment, while 3-MA further aggravated injury and inhibited the protection of H2 and RAP. Furthermore, the intracellular ROS and apoptosis ratio were determined, the results showed that ROS and apoptosis level significantly increased after OGD/R, H2 and RAP effectively restrained the increment of ROS level and apoptosis ratio but their protective effect can be weakened by 3-MA. Mitochondrial membrane potential (MMP) and mitophagy level were also determined, the data showed that H2 and RAP protected against the loss of MPP and increased the co-localization of mitochondria with GFP-LC3 while 3-MA exerted antagonistic effect. At last, the mitophagy-related factors LC3, PINK1 and Parkin expression were detected and analyzed. We found that the expression of LC3 was increased after OGD/R which can be further enhanced by H2 and RAP treatment, but treatment with 3-MA was opposite. The result revealed H2 and RAP could activate mitophagy while 3-MA inhibit mitophagy. In addition, the study found H2 and RAP could significantly induce the expression of PINK1 and Parkin in OGD/R neurons which was inhibited by 3-MA. Taken together, our findings demonstrated H2 had a neuroprotective effect on OGD/R damaged neurons by protecting mitochondrial function and the potential protection mechanism may closely related to enhancement of mitophagy mediated by PINK1/Parkin signaling pathway. [ABSTRACT FROM AUTHOR]