1,589 research outputs found

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    Three-Dimensional Microscopic Image Reconstruction Based on Structured Light Illumination

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    In this paper, we propose and experimentally demonstrate a three-dimensional (3D) microscopic system that reconstructs a 3D image based on structured light illumination. The spatial pattern of the structured light changes according to the profile of the object, and by measuring the change, a 3D image of the object is reconstructed. The structured light is generated with a digital micro-mirror device (DMD), which controls the structured light pattern to change in a kHz rate and enables the system to record the 3D information in real time. The working distance of the imaging system is 9 cm at a resolution of 20 μm. The resolution, working distance, and real-time 3D imaging enable the system to be applied in bridge and road crack examinations, and structure fault detection of transportation infrastructures

    Spectrophotometric detection of uric acid with enzyme-like reaction mediated 3,3′,5,5′-tetramethylbenzidine oxidation

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    ABSTRACT. WO3 nanosheets (NSs) were prepared and characterized by X-ray photoelectron spectrometer (XPS), X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The obtained WO3 NSs exhibited peroxidase-like catalytic activity, which can catalyze H2O2 to oxidize       3,3 ',5,5 '-tetramethylbenzidine (TMB) to generate oxidized TMB (oxTMB) with an absorption peak centered at 652 nm. Based on this, a facile method for the spectrophotometric determination of H2O2 was established. Under the selected conditions, the increase in absorbance of oxTMB enabled the detection of H2O2 ranging from 2.0 to 180 μM. Considering the fact that H2O2 is one of the products of urate oxidase (UAO)-catalyzed uric acid (UA) oxidation, a convenient method for the selective determination of UA was further developed with the help of UV–vis spectrophotometer. The increase of absorbance at 652 nm showed a linear response to UA concentration over the range of 2.0–180 μM. The limit of detection for UA was as low as 1.25 μM. More importantly, the proposed method was applied to the determination of UA in serum samples with satisfactory results.   KEY WORDS: Spectrophotometric, WO3 nanosheets, Uric acid, Determination   Bull. Chem. Soc. Ethiop. 2023, 37(1), 11-21.                                                             DOI: https://dx.doi.org/10.4314/bcse.v37i1.2&nbsp

    Spatial and Modal Optimal Transport for Fast Cross-Modal MRI Reconstruction

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    Multi-modal magnetic resonance imaging (MRI) plays a crucial role in comprehensive disease diagnosis in clinical medicine. However, acquiring certain modalities, such as T2-weighted images (T2WIs), is time-consuming and prone to be with motion artifacts. It negatively impacts subsequent multi-modal image analysis. To address this issue, we propose an end-to-end deep learning framework that utilizes T1-weighted images (T1WIs) as auxiliary modalities to expedite T2WIs' acquisitions. While image pre-processing is capable of mitigating misalignment, improper parameter selection leads to adverse pre-processing effects, requiring iterative experimentation and adjustment. To overcome this shortage, we employ Optimal Transport (OT) to synthesize T2WIs by aligning T1WIs and performing cross-modal synthesis, effectively mitigating spatial misalignment effects. Furthermore, we adopt an alternating iteration framework between the reconstruction task and the cross-modal synthesis task to optimize the final results. Then, we prove that the reconstructed T2WIs and the synthetic T2WIs become closer on the T2 image manifold with iterations increasing, and further illustrate that the improved reconstruction result enhances the synthesis process, whereas the enhanced synthesis result improves the reconstruction process. Finally, experimental results from FastMRI and internal datasets confirm the effectiveness of our method, demonstrating significant improvements in image reconstruction quality even at low sampling rates

    Diaqua­bis­(5-methyl­pyrazine-2-carboxyl­ato-κ2 N 1,O)cobalt(II) dihydrate

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    In the title complex, [Co(C6H5N2O2)2(H2O)2]·2H2O, the coordination geometry of the Co2+ cation is distorted octa­hedral, with two N atoms and two O atoms from two 5-methyl­pyrazine-2-carboxyl­ate ligands in the equatorial plane. The two remaining coordination sites are occupied by two water mol­ecules. In addition, there are two uncoordinated water mol­ecules in the asymmetric unit. The crystal structure is stabilized by a network of O—H⋯O and O—H⋯N hydrogen-bonding inter­actions, forming a three-dimensional structure
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