Purpose
Manual contouring of gross tumor volumes (GTV) is a crucial and time‐consuming process in rectum cancer radiotherapy. This study aims to develop a simple deep learning‐based autosegmentation ...algorithm to segment rectal tumors on T2‐weighted MR images.
Material and methods
MRI scans (3T, T2‐weighted) of 93 patients with locally advanced (cT3‐4 and/or cN1‐2) rectal cancer treated with neoadjuvant chemoradiotherapy followed by surgery were enrolled in this study. A 2D U‐net similar network was established as a training model. The model was trained in two phases to increase efficiency. These phases were tumor recognition and tumor segmentation. An opening (erosion and dilation) process was implemented to smooth contours after segmentation. Data were randomly separated into training (90%) and validation (10%) datasets for a 10‐folder cross‐validation. Additionally, 20 patients were double contoured for performance evaluation. Four indices were calculated to evaluate the similarity of automated and manual segmentation, including Hausdorff distance (HD), average surface distance (ASD), Dice index (DSC), and Jaccard index (JSC).
Results
The DSC, JSC, HD, and ASD (mean ± SD) were 0.74 ± 0.14, 0.60 ± 0.16, 20.44 ± 13.35, and 3.25 ± 1.69 mm for validation dataset; and these indices were 0.71 ± 0.13, 0.57 ± 0.15, 14.91 ± 7.62, and 2.67 ± 1.46 mm between two human radiation oncologists, respectively. No significant difference has been observed between automated segmentation and manual segmentation considering DSC (P = 0.42), JSC (P = 0.35), HD (P = 0.079), and ASD (P = 0.16). However, significant difference was found for HD (P = 0.0027) without opening process.
Conclusion
This study showed that a simple deep learning neural network can perform segmentation for rectum cancer based on MRI T2 images with results comparable to a human.
Abstract
In this work, via engineering the conformation of cobalt active center in cobalt phthalocyanine molecular catalyst, the catalytic efficiency of electrochemical carbon monoxide reduction to ...methanol can be dramatically tuned. Based on a collection of experimental investigations and density functional theory calculations, it reveals that the electron rearrangement of the Co 3d orbitals of cobalt phthalocyanine from the low-spin state (S = 1/2) to the high-spin state (S = 3/2), induced by molecular conformation change, is responsible for the greatly enhanced CO reduction reaction performance.
Operando
attenuated total reflectance surface-enhanced infrared absorption spectroscopy measurements disclose accelerated hydrogenation of CORR intermediates, and kinetic isotope effect validates expedited proton-feeding rate over cobalt phthalocyanine with high-spin state. Further natural population analysis and density functional theory calculations demonstrate that the high spin Co
2+
can enhance the electron backdonation via the
d
xz
/
d
yz
−2π* bond and weaken the C-O bonding in *CO, promoting hydrogenation of CORR intermediates.
Sem image of PP aerogel (0.1 g/ml).
As shown in above figure, PP aerogel displays three-dimensional porous network structures consisting of petal-like porous particles (15–30 μm) and the petal-like ...particle closely arranged together.
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•Petal-like porous polypropylene aerogels were prepared by thermal induced phase separation(TIPS) and supercritical CO2 drying.•The PP aerogel with a porous micro-nanoscale surface morphology which showed superhydrophobicity.•The PP aerogel coated on PU sponge or PP nonwoven fabric can be used for oil-water separation application.
Preparation and characterization of Polypropylene (PP) aerogel materials and aerogel coated materials with superhydrophobicity for oil-water separation application were investigated. The PP aerogel material and the coated materials were prepared from a solution of PP in xylene solvent (PP sole) by a cooling process, which resulted in the thermally induced phase separation of the polypropylene molecular network and further solvent extraction from the molecular network by a supercritical CO2 drying process. The PP aerogel displayed a porous surface morphology with flower petals like micro-nanoscale structural features. The aerogel materials showed superhydrophobicity with contact angle greater than 150°. Further the aerogel was coated on a polyurethane sponge material and a PP nonwoven fabric materials to prepare hybrid materials having a aerogel surface characteristics. The effectiveness and recyclability of the PP aerogel and the aerogel coated hybrid material for oil-water separation was investigated using model oil solvents. The study revealed the high potential of these materials in oil-water separation applications and these could be inexpensive replacement to the available alternatives.
•The B-TiO2/CuInS2 Z-scheme heterojunction with visible light response was prepared.•B-TiO2/CuInS2 could convert CO2 into CO and CH4 with the yields 21.39 and 4.83 µmol g−1 h−1.•Both boron doping and ...CuInS2 sensitization can effectively improve the utilization of visible light.•The synergistic effect of B doping Z-scheme heterojunction optimized the separation and migration of photogenerated carriers.
Photocatalytic reduction CO2 into valuable solar fuels is a promising strategy to alleviate the greenhouse effect and the energy crisis on Earth. In this work, a B-TiO2/CuInS2 photocatalyst has been synthesized through a simple hydrothermal-calcination method for efficient reducing CO2 into CO and CH4. Boron doping and sensitization of CuInS2 ensure the excellent visible light response capacity of the composite catalyst. The synergistic effect between oxygen vacancies and Z-scheme heterojunction also endow the photocatalyst with strong carrier separation capability. Consequently, the optimized B-TO/CIS-2.5 sample exhibited the best CO (21.39 μmol g−1 h−1) and CH4 (4.83 μmol g−1 h−1) production, approximately 9 and 14 times higher than that of TO and B-TO, respectively. This study provides a reliable approach for developing photocatalysts with boosted CO2 reduction activity and high stability.
In this study, the stereochemistry, stereoselective fungicidal bioactivity, and antifungal mechanism of chiral triazole fungicide metconazole were investigated. The configurations of metconazole ...stereoisomers were determined to be (1R, 5R)-metconazole, (1R, 5S)-metconazole, (1S, 5S)-metconazole, and (1S, 5R)-metconazole through using electronic circular dichroism spectroscopy. The bioactivities of four stereoisomers and their stereoisomer mixture toward Fusarium graminearum Schw and Alternaria triticina were found to be in the following order: (1S, 5R)-metconazole > the stereoisomer mixture > (1S, 5S)-metconazole > (1R, 5R)-metconazole > (1R, 5S)-metconazole. In addition, the fungicidal activities of (1S, 5R)-metconazole against two tested pathogens was 13.9–23.4 times higher than those of (1R, 5S)-metconazole. Molecular docking methodology was applied to characterize the docking energy and distances between Cytochrome P450 CYP51B and the metconazole stereoisomers, and (1S, 5R)-metconazole showed the strongest binding energy and the shortest distance binding to CYP51B than the other three stereoisomers. Moreover, enantioselective metabolisms of (1S, 5R)-metconazole and (1R, 5S)-metconazole by Fusarium graminearum Schw were investigated through NMR-based metabolomics. The amounts of alanine, arginine, acetate, ethanol, and dimethylamine produced in the presence of (1R, 5S)-metconazole were significantly higher than corresponding amounts in the presence of (1S, 5R)-metconazole, whereas the amounts of glucose, glycerol, glutamate, methionine, and trimethylamine formed in the presence of (1R, 5S)-metconazole were much less than those in the presence of (1S, 5R)-metconazole. This systematic investigation of metconazole stereoisomers would provide a new perception of metconazole in stereoisomeric level, including bioactivities, metabolic behaviors and antifungal mechanism.
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•Absolute configuration of metconazole stereoisomers was confirmed through ECD spectra.•Metconazole showed stereoselective fungicidal activities against two pathogens.•Docking results supported enantiospecific binding of metconazole with CYP51B.•NMR-based metabolomics was applied in metabolism of pathogen treated by enantiomers.
Promoting oligodendrocyte viability has been proposed as a therapeutic strategy for alleviating many neuronal diseases, such as multiple sclerosis and stroke. However, molecular pathways critical for ...oligodendrocyte survival under various stresses are still not well known. p53 is a strong tumor suppressor and regulates cell cycle, DNA repair and cell death. Our previous studies have shown that p53 plays an important role in promoting neuronal survival after insults, but its specific role in oligodendrocyte survival is not known. Here, we constructed the mice with oligodendrocyte-specific p53 loss by crossing TRP53
mice and CNP-cre mice, and found that p53 was dispensable for oligodendrocyte differentiation and myelin formation under physiological condition. In the experimental autoimmune encephalomyelitis (EAE) model, p53 loss of function, specifically in oligodendrocytes, did not affect the EAE disease severity and had no effect on demyelination in the spinal cord of the mice. Interestingly, p53 deficiency in oligodendrocytes significantly attenuated the demyelination of corpus callosum and alleviated the functional impairment of motor coordination and spatial memory in the cuprizone demyelination model. Moreover, the oligodendrocyte-specific loss of p53 provided protection against subcortical white matter damage and mitigated recognition memory impairment in mice in the white matter stroke model. These results suggest that p53 plays different roles in the brain and spinal cord or in response to various stresses. Thus, p53 may be a therapeutic target for oligodendrocyte prevention in specific brain injuries, such as white matter stroke and multiple sclerosis.
We report herein an efficient approach for the enantioselective synthesis of inherently chiral calix4arenes via palladium-catalyzed asymmetric intramolecular C-H arylations. Using a chiral ...bifunctional phosphine-carboxylate ligand, the inherent chirality on macrocyclic scaffolds was induced successfully, from which a wide range of calix4arenes with fluorenone motifs were obtained with good yields and excellent enantioselectivities (up to >99% ee). The synthetic utility of this method was demonstrated by diverse transformations of the products, thus substantially expanding the chemical space of chiral calix4arenes. Further investigations of photophysical and chiroptical properties revealed that calix4arenes bearing two fluorenone moieties displayed remarkable
values (up to 0.019), highlighting the great potential of inherent chirality in the development of organic optoelectronic materials.
Using photocatalysis to reduce carbon dioxide to hydrocarbons is a promising way to mitigate the greenhouse effect and the energy crisis simultaneously. However, conventional photocatalytic ...technology is inefficient due to its low utilization of the full spectrum. Photothermal effect can combine the advantages of photocatalysis and thermocatalysis to overcome inherent defects and elevate the catalytic activity by one order of magnitude compared with single photocatalysis. This review focuses on the generation and promotion mechanism of photothermal effect on photocatalytic reduction of CO2. In addition, the developments of several practical catalysts with photothermal effect are presented, including non-precious metal-based catalysts, precious metal-based catalysts, and oxygen vacancy-riched catalysts. Eventually, the prospects and challenges of the applications of the photothermal effect are in consideration, which is instructive for the discovery of non-expensive and efficient photothermal catalysts for photocatalytic reduction of CO2.
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•The photothermal effect is particularly beneficial to CO2 photocatalytic process.•The origin of photothermal effect is explained.•The promoting mechanism of photothermal effect on CO2 reduction is summarized.•Several excellent photothermal catalysts for CO2 reduction are presented.
Summary
Three‐dimensional (3D) food printing is a digital food engineering method that has a remarkable application potential in long‐term manned spaceflight. Extrusion‐based 3D food printing, among ...the available 3D food printing techniques utilised in the food industry, is one of the most suitable printing methods for manned spaceflight. Extrusion‐based 3D food printing could suffice most of the energy and personalised nutritional requirements of astronauts during long‐term stay in space by utilising fruits, vegetables, meat products, and nutrients as printing materials. However, 3D food printing in manned spaceflight is still limited by technologies and costs such as printing materials, microgravity, post‐processability of food, and engineering transportation under the existing technical conditions. Therefore, this article reviews the 3D food printing and manned spaceflight technologies that are currently available and discusses the challenges involved in 3D food printing in manned spaceflight, thus providing a theoretical basis for future 3D food printing for space missions.
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