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.

Enzymatic Desymmetrization of 3-(4-Fluorophenyl)glutaric Anhydride through Enantioselective Alcoholysis in Organic Solvents

Weiming Liu,Yi Hu,Yang Zhang,Yan Ma,He Huang 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.3

The enzymatic desymmetrization of 3-(4-fluorophenyl)glutaric anhydride (3-FGA) was investigatedthrough lipase-catalyzed enantioselective alcoholysis inorganic solvents. An immobilized Lipase B from CandidaAntarctica (Novozym 435) was found to be an efficientbiocatalyst for the enantioselective alcoholysis of 3-FGA. Methyl tert-butyl ether (MTBE) and methanol were chosenas the suitable reaction medium and acyl acceptor,respectively. The optimum reaction temperature, molarratio of methanol to 3-FGA and 3-FGA concentration were25oC, 2:1 and 100 mM, respectively. Under these conditions,complete conversion was achieved and methyl (S)-3-(4-fluorophenyl)glutarate ((S)-MFG) was obtained in a moderateee value of 80%. Furthermore, the reaction was performedon a gram scale and the ee value of (S)-MFG was enrichedto 96% after treatment with a toluene/hexane (2/1, v/v)mixture.

Upright Orientation of 3D shapes via Tensor Rank Minimization

Weiming Wang,Xiuping Liu,Ligang Liu (사)한국CDE학회 2013 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

In general, the upright orientation of a model is beneficial for human to recognize this model and is widely used in geometry processing and computer graphics. However, the orientation of the model obtained by existing technologies, such as 3D scanning systems or modeling, may be far away from the right orientation. In order to solve this problem, a robust and efficient upright method is needed. We observe that when the model is aligned with the three axes, the rank of the three-order tensor constructed by this model is the lowest usually. Inspired by this observation, we formulate the alignment of the 3D model with axes as a low-rank tensor optimization problem which is a global and unsupervised method. After the 3D model has been aligned with the three axes, some geometric properties can be used to pick out the best upright orientation from the six candidate supporting bases easily. The three-order tensor is constructed by voxelizing the bounding box of the 3D model, and then filling the voxel element with zero or one based on whether it contains the points of the model or not. The experimental results demonstrate that our method is robust, efficient and effective for all kinds of the models (manifold or non-manifold, man-made or non-artificial, or point cloud).

A High Efficiency Integrated Step-down Cuk and Flyback converter for LED Power driver

Weiming Lin,Xu Yuzhen,QingLiang Zheng 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Due to the enormous progress recently achieved in the technology of light emitting diodes (LEDs), they are expected to replace conventional lamps in automotive applications in the near future and incandescent, halogen and fluorescent lamps at least in some general illumination applications within a few years. Innovative driver circuits optimized with respect to functionality, efficiency, cost, size and reliability are an enabler for the successful introduction of new LED based lighting products. A low ripple and high efficiency single-stage power driver is proposed for LED lighting in this paper. The proposed single-stage power driver integrated a step-down Cuk rectifier for power-factor correction (PFC) with the isolated flyback converter for DC-DC power conversion. In the proposed single-stage stepdown Cuk rectifier achieve low input ripple and output ripple and lower switch stress, and reduce the two energy conversion stages to improve the driver efficiency. The analysis of the proposed converter is presented and experimental results based on 0.75A, 30 W prototype are provided to demonstrate the performance of the proposed driver.

Velocity Control of Permanent Magnet Stepper Motor Using Nonsingular Terminal Sliding Mode Controller

WEIMING YANG(양위명),Yong Woo Jeong(정용우),Chung Choo Chung(정정주) 제어로봇시스템학회 2019 제어로봇시스템학회 국내학술대회 논문집 Vol.2019 No.5

Upright orientation of 3D shapes via tensor rank minimization

Weiming Wang,Xiuping Liu,Ligang Liu 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7

In general, the upright orientation of a model is beneficial for human to recognize this model and is widely used in geometry processingand computer graphics. However, the orientation of the model obtained by existing technologies, such as 3D scanning systems ormodeling, may be far away from the right orientation. In order to solve this problem, a robust and efficient upright method is needed. Weobserve that when the model is aligned with the three axes, the rank of the three-order tensor constructed by this model is the lowest usually. Inspired by this observation, we formulate the alignment of the 3D model with axes as a low-rank tensor optimization problemwhich is a global and unsupervised method and the genetic algorithm (GA) is used to solve this optimization problem. After the 3Dmodel has been aligned with the three axes, some geometric properties can be used to pick out the best upright orientation from the sixcandidate supporting bases easily. The three-order tensor is constructed by voxelizing the bounding box of the 3D model, and then fillingthe voxel element with zero or one based on whether it contains the points of the model or not. The experimental results demonstrate thatour method is robust, efficient and effective for all kinds of the models (manifold or non-manifold, man-made or non-artificial, or pointcloud).

Stage-specific embryonic antigen: determining expression in canine glioblastoma, melanoma, and mammary cancer cells

Weiming Lin,Jaime F Modiano,Daisuke Ito 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.1

The expression of stage-specific embryonic antigens (SSEAs) was determined in several types of canine cancer cells. Flow cytometry showed SSEA-1 expression in glioblastoma, melanoma, and mammary cancer cells, although none expressed SSEA-3 or SSEA-4. Expression of SSEA-1 was not detected in lymphoma, osteosarcoma, or hemangiosarcoma cell lines. Relatively stable SSEA-1 expression was observed between 24 and 72 h of culture. After 8 days in culture, sorted SSEA-1− and SSEA-1+ cells re-established SSEA-1 expression to levels comparable to those observed in unsorted cells. Our results document, for the first time, the expression of SSEA-1 in several canine cancer cell lines.

Preconditioning for the $p$-version boundary element method in three dimensions with triangular elements

Weiming Cao,Benqi Guo 대한수학회 2004 대한수학회지 Vol.41 No.2

A preconditioning algorithm is developed in this paper for the iterative solution of the linear system of equations resulting from the p-version boundary element approximation of the three dimensional integral equation with hypersingular operators. The preconditioner is derived by first making the nodal and side basis functions locally orthogonal to the element internal bases, and then by decoupling the nodal and side bases from the internal bases. Its implementation consists of solving a global problem on the wirebasket and a series of local problems defined on a single element. Moreover, the condition number of the preconditioned system is shown to be of order O((1 + ln p)7). This technique can be applied to discretization with triangular elements and with general basis functions.

Template-free hydrothermal synthesis of hollow alumina microspheres and its excellent catalytic properties for thiolation

WeiMing Wang,Shuai Peng,XinTian Chen,YingMing Chen,Chuang Peng,Dong Zeng,Jun Xiong,Hao Liu,XiXian Yang,Ming Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

In view of the important industrial application value of alumina supports in the field of oil refining andreforming, it is of great significance to develop a simple and economical synthesis method for the hierarchicalporous alumina. Herein, the hollow microsphere alumina was hydrothermally synthesized withouttemplate. The surface of the hollow microsphere alumina supports has a raised fluffy structure, themicrosphere diameter is about 5 8 lm, and the thickness of the shell is about 1 lm. The morphologyevolution process from solid microspheres to core–shell microspheres with spindle-shaped nanoclusters,and then to hollow fluffy microspheres with protruding surface was observed by investigating the effectof hydrothermal synthesis temperature on the morphology of microspheres. Because of its specific morphologyand surface characteristics, the microsphere can better disperse the active component KW toprepare KW/Al2O3 catalyst and used in the thiolation to methyl mercaptan. Compared with our previouslyused catalysts prepared from commercial alumina, this KW/Al2O3 catalyst was not only able togreatly reduce the amount of active component, but also exhibited higher CH3SH selectivity. On the10KW/Al catalyst, the CH3SH selectivity reached 66.2 % at 340 C, which was about 10 % higher than thatof the previous commercial alumina catalyst. This work can provide theoretical basis and practical guidancefor the reasonable design of new alumina support and high efficiency methyl mercaptan catalyst.

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+.