Contrast-enhanced ultrasonography-based renal blood perfusion in brain-dead donors predicts early graft function

Weiming He,Yuguang Xu,Chaoyang Gong,Xiaozhen Liu,Yuqiang Wu,Xi Xie,Jiazhen Chen,Yi Yu,Zhiyong Guo,Qiang Sun 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.4

Purpose: The aim of this study was to quantify renal microcirculatory perfusion in braindead donors using contrast-enhanced ultrasonography (CEUS), and to establish an accurate, noninvasive, and convenient index for predicting delayed graft function (DGF) post-transplantation. Methods: In total, 90 brain-dead donor kidneys (training group, n=60; validation group, n=30) examined between August 2020 and November 2022 were recruited in this prospective study. CEUS was performed on the kidneys of brain-dead donors 24 hours before organ procurement and time-intensity curves were constructed. The main measures were arrival time, time to peak, and peak intensity of the kidney segmental arteries, cortex, and medulla. Recipients were divided into DGF and non-DGF groups according to early post-transplant graft function. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. Results: The arrival time of the kidney segmental artery and cortex and the time interval between the time to peak of the segmental artery and cortex were identified as independent factors associated with DGF by multivariate stepwise regression analysis. A new index for the joint prediction model of three variables, the contrast-enhanced ultrasonography/Kidney Donor Profile index (CEUS-KDPI), was developed. CEUS-KDPI showed high accuracy for predicting DGF (training group: AUC, 0.91; sensitivity, 90.5%; specificity, 92.3%; validation group: AUC, 0.84; sensitivity, 75.0%; specificity, 92.3%). Conclusion: CEUS-KDPI accurately predicted DGF after kidney transplantation. CEUS may be a potential noninvasive tool for bedside examinations before organ procurement and may be used to predict early renal function after kidney transplants kidneys from donors after brain death.

Trisodium citrate-assisted synthesis of BiOBr nanostructure catalyst for efficient activity under visible light

Weiming Zhou,Yifan Jiang,Shichang Sun,Mingxin Zhang,Ibrahim Lawan,Gerard Franklyn Fernando,Liwei Wang,Zhanhui Yuan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

A simple one step wet-chemical method assisted by trisodium citrate was employed in the synthesis of BiOBr applied as a photocatalyst. Photocatalytic activity of the BiOBr was investigated for the degradation of Rhodamine B (RhB) dye under visible light irradiation (>420 nm). The results indicated that trisodium citrate is more favorable to the formation of hierarchical architectures and reduces the particle size of BiOBr photocatalyst. BiOBr with hierarchical architectures exhibiting significantly higher catalytic activity than that with ordinary nanostructure. The significant improvement could be attributed to the high specific surface area (24.14m2·g1), average pore sizes (34.09 nm) and average pore volume (0.24 cm3·g1).

The impacts of resveratrol on the retinal degeneration in a rat model of retinitis pigmentosa induced by alkylation: an in-vivo study

Weiming Yan,Yan Sun,Yutong Wang,Wangjiao Liang,Yuxin Xia,Weihua Yan,Meizhu Chen,Tao Chen,Dongliang Li 한국통합생물학회 2023 Animal cells and systems Vol.27 No.1

Upregulation of Sirtuin Type 1 (SIRT1), a nicotinamide adeninedinucleotide (NAD+)-dependentdeacetylase, has been proved to protect against ample ocular diseases, while its effect onretinitis pigmentosa (RP) has not been illustrated. The study was aimed to explore the impactsof resveratrol (RSV), a SIRT1 activator, on the photoreceptor degeneration in a rat model of RPinduced by N-methyl-N-nitrosourea (MNU), an alkylation. The rats were induced RP phenotypesvia the intraperitoneal injection of MNU. The electroretinogram was conducted and revealedthat RSV could not prevent the decline of retinal function in the RP rats. The optical coherencetomography (OCT) and the retinal histological examination were performed and showed thatthe reduced thickness of the outer nuclear layer (ONL) was not preserved by RSV intervention. The immunostaining technique was applied. Afther the MNU administration, the number of theapoptotic photoreceptors in the ONL throughout the retinasand the number of microglia cellspresent among the outer part throughout the retinas were not significantly reduced by RSV. Western blotting was also performed. The data showed that the level of SIRT1 protein wasdecreased after MNU administration, while RSV was not able to obviously alleviate thedownregulation. Our data together indicated that RSV was not able to rescue thephotoreceptor degeneration in the MNU-induced RP rats, which might be due to the MNUinducedconsumption of the NAD+.

Novel Strategy for Reducing Residual Stress in Titanium Alloy Parts Obtained via Additive Manufacturing

Xinfa Sun,Yucheng Zhao,Weiming Yang,Wenyu Li,Dengfeng Yang,Haishun Liu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

The additive manufacturing of titanium alloy parts has important scientific significance and practical value. Controllingthe distribution of residual stress caused by the high cooling rate and temperature gradient is the key to regulating the performanceof devices obtained from additive manufacturing. In this work, the effects of the interlayer scanning angle on theresidual stress in Ti–6Al–4V parts manufactured by selective laser melting were investigated by finite element simulations. We studied how changing the interlayer deflection angle alleviated residual stress under different energy inputs. The resultsshowed that the residual stress in the z-direction was reduced by the deflection angle of 67° and 90°, and the non-uniformdistribution of residual stress was reduced by a deflection angle of 67°. The combination of a chessboard pattern and interlayerdeflection angle greatly alleviated the generation of residual stress. This work has important guiding significance forthe additive manufacturing design of high-quality and high-performance titanium alloy devices.

Sclareol Protects Staphylococcus aureus-Induced Lung Cell Injury via Inhibiting Alpha-Hemolysin Expression

( Ouyang Ping ),( Sun Mao ),( He Xuewen ),( Wang Kaiyu ),( Yin Zhongqiong ),( Fu Hualin ),( Li Yinglun ),( Geng Yi ),( Shu Gang ),( He Changliang ),( Liang Xiaoxia ),( Lai Weiming ),( Li Lixia ),( Zou 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.1

Staphylococcus aureus (S. aureus) is a common gram-positive bacterium that causes serious infections in humans and animals. With the continuous emergence of methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting, and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with A549 epithelial cells, sclareol could protect the A549 cells at a final concentration of 8 μg/ml. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.

Facile construction of a Bi6O6(OH)3(NO3)3·1.5H2O/Bi2O2CO3 heterojunction with enhanced photocatalytic degradation activity

Huilan Ye,Yiting Wu,Ziqing Zhong,Shichang Sun,Jia Chen,Weiming Zhou,Ibrahim Lawan,Liwei Wang,Zhanhui Yuan 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

A Bi6O6(OH)3(NO3)3·1.5H2O (BBN)/Bi2O2CO3 (BOC) heterojunction was designed for the first time via afacile hydrothermal method. The photocatalytic performance of catalysts was evaluated by degrading Rhodamine B(RhB) under simulated solar light irradiation. It was found that the degradation rate of RhB by 25 wt%BBN/BOC wasdramatically increased about 1.5 and 4.7 times compared with that of pure BOC and BBN, respectively. The enhancedphotocatalytic performance migth be attributed to the effective separation of photoinduced electron-hole pairs, benefitingfrom the construction of heterojunction. Furthermore, the mechanism upon BBN/BOC composites photocatalystwas investigated, expecting this work will bring new insight into the theoretical study and application of semiconductorsmaterials.

Decision-making for Connected and Automated Vehicles in Chanllenging Traffic Conditions Using Imitation and Deep Reinforcement Learning

Hu Jinchao,Li Xu,Hu Weiming,Xu Qimin,Huyue Sun 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.6

Decision-making is the “brain” of connected and automated vehicles (CAVs) and is vitally critical to the safety of CAVs. The most of driving data used to train the decision-making algorithms is collected in general traffic conditions. Existing decision-making methods are difficult to guarantee safety in challenging traffic conditions, namely severe congestion and accident ahead. In this context, a semi-supervised decision-making algorithm is proposed to improve the safety of CAVs in challenging traffic conditions. To be specific, we proposed the expert-generative adversarial imitation learning (E-GAIL) that integrates imitation learning and deep reinforcement learning. The proposed E-GAIL is deployed in roadside unit (RSU). In the first stage, the decision-making knowledge of the expert is imitated using the real-world data collected in general traffic conditions. In the second stage, the generator of E-GAIL is further reinforced and achieves self-learn decision-making in the simulator with challenging traffic conditions. The E-GAIL is tested in general and challenging traffic conditions. By comparing the evaluation metrics of time to collision (TTC), deceleration to avoid a crash (DRAC), space gap (SGAP) and time gap (TGAP), the E-GAIL greatly outperforms the state-of-the-art decision-making algorithms. Experimental results show that the E-GAIL not only make-decision for CAVs in general traffic conditions but also successfully enhances the safety of CAVs in challenging traffic conditions.

A self-powered β-Ga2O3/CsCu2I3 heterojunction photodiode responding to deep ultraviolet irradiation

Gao Ang,Jiang Weiyu,Ma Guoliang,Liu Zeng,Li Shan,Yan Zuyong,Sun Weiming,Zhang Shaohui,Tang Weihua 한국물리학회 2022 Current Applied Physics Vol.33 No.-

In this paper, a lead-free halide perovskite CsCu2I3 film with high stability was prepared by the anti-solvent assisted crystallization method. Then, we coupled it with Ga2O3 to prepare a corresponding heterojunction deep ultraviolet (UV) photodetector. After testing, we concluded that the photodetector is sensitive to 254 nm UV light. The photodetector has good reproducibility, and has an ultra-high photo-to-dark current ratio (PDCR) of more than 105. In addition, under a bias of 10 V and an illuminated intensity of 200 μW/cm2, the responsivity (R) and specific detectivity (D*) reached 20 mA/W and 107 cm Hz1/2 W 1 (Jones), and the external quantum efficiency (EQE) is 10%. Meanwhile, the prepared photodetector could operate at zero bias, i.e., self-powered operation, along with a photocurrent of about 1 nA under illumination with UV light intensity of 200 μW/cm2.