Interventional Therapy for Renal Artery Pseudoaneurysms

Ji, Wen-Bin,Wang, Wei-Zheng,Sun, Song,Mi, Yu-Cheng,Xu, Qiong,Chen, Yi-Er,Yang, Song,Tao, Dan,Xu, Wei,Xu, Chao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

The aim of this study was to explore the angiographic diagnosis and embolization therapy for renal artery pseudoaneurysms due to acute urinary tract hemorrhage after conservative medical management failed. Seven out of ten cases had fever symptoms after the kidney surgery. The pseudoaneurysms were treated with gelatin sponge and (or) spring coil and the majority demonstrated rapid blockage of hemorrhage. Angiography diagnosis and trans catheter embolization are rapid, safe and effective methods for diagnosis and treatment of renal artery pseudoaneurysms.

Influence of high-cycle fatigue on the tension stiffening behavior of flexural reinforced lightweight aggregate concrete beams

Chen, How-Ji,Liu, Te-Hung,Tang, Chao-Wei,Tsai, Wen-Po Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.6

The objective of this study was to experimentally investigate the bond-related tension stiffening behavior of flexural reinforced concrete (RC) beams made with lightweight aggregate concrete (LWAC) under various high-cycle fatigue loading conditions. Based on strain measurements of tensile steel in the RC beams, fatigue-induced degradation of tension stiffening effects was evaluated and was, compared to reinforced normal weight concrete (NWC) beams with equal concrete compressive strengths (40 MPa). According to applied load-mean steel strain relationships, the mean steel strain that developed under loading cycles was divided into elastic and plastic strain components. The experimental results showed that, in the high-cycle fatigue regime, the tension stiffening behavior of LWAC beams was different from that of NWC beams; LWAC beams had a lesser reduction in tension stiffening due to a better bond between steel and concrete. This was reflected in the stability of the elastic mean steel strains and in the higher degree of local plasticity that developed at the primary flexural cracks.

Shear behavior of reinforced HPC beams made of a low cement content without shear reinforcements

Chao-Wei Tang,Yu-Ping Chen,How-Ji Chen,Chung-Ho Huang,Tsang-Hao Liu 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.1

High-performance concrete (HPC) usually has higher paste and lower coarse aggregate volumes than normal concrete. The lower aggregate content of HPC can affect the shear capacity of concrete members due to the formation of smooth fractured surfaces and the subsequent development of weak interface shear transfer. Therefore, an experimental investigation was conducted to study the shear strength and cracking behavior of full-scale reinforced beams made with low-cement-content high-performance concrete (LcHPC) as well as conventional HPC. A total of fourteen flexural reinforced concrete (RC) beams without shear reinforcements were tested under a two-point load until shear failure occurred. The primary design variables included the cement content, the shear span to effective depth ratio (a/d), and the tensile steel ratio (ρw). The results indicate that LcHPC beams show comparable behaviors in crack and ultimate shear strength as compared with conventional HPC beams. Overall, the shear strength of LcHPC beams was found to be larger than that of corresponding HPC beams, particularly for an a/d value of 1.5. In addition, the crack and ultimate shear strength increased as a/d decreased or ρw increased for both LcHPC beams and HPC beams. This investigation established that LcHPC is recommendable for structural concrete applications.

FPGA Implementation of SC-FDE Timing Synchronization Algorithm

Ji, Suyuan,Chen, Chao,Zhang, Yu Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.4

The single carrier frequency domain equalization (SC-FDE) technology is an important part of the broadband wireless access communication system, which can effectively combat the frequency selective fading in the wireless channel. In SC-FDE communication system, the accuracy of timing synchronization directly affects the performance of the SC-FDE system. In this paper, on the basis of Schmidl timing synchronization algorithm a timing synchronization algorithm suitable for FPGA (field programmable gate array) implementation is proposed. In the FPGA implementation of the timing synchronization algorithm, the sliding window accumulation, quantization processing and amplitude reduction techniques are adopted to reduce the complexity in the implementation of FPGA. The simulation results show that the algorithm can effectively realize the timing synchronization function under the condition of reducing computational complexity and hardware overhead.

Solutions of several open problems

Chao-Ping Chen,Ji-En Deng 장전수학회 2012 Advanced Studies in Contemporary Mathematics Vol.22 No.4

The main object of this paper is to solve several open problems proposed by Zhang and X_u, Bencze, and Simic. (i) We prove that for x > 0, [수식].

Time-dependent properties of lightweight concrete using sedimentary lightweight aggregate and its application in prestressed concrete beams

Chen, How-Ji,Tsai, Wen-Po,Tang, Chao-Wei,Liu, Te-Hung Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.6

We have developed a lightweight aggregate (LWA) concrete made by expanding fine sediments dredged from the Shihmen Reservoir (Taiwan) with high heat. In this study, the performance of the concrete and of prestressed concrete beams made of the sedimentary LWA were tested and compared with those made of normal-weight concrete (NC). The test results show that the lightweight concrete (LWAC) exhibited comparable time-dependent properties (i.e., compressive strength, elastic modulus, drying shrinkage, and creep) as compared with the NC samples. In addition, the LWAC beams exhibited a smaller percentage of prestress loss compared with the NC beams. Moreover, on average, the LWAC beams could resist loading up to 96% of that of the NC beams, and the experimental strengths were greater than the nominal strengths calculated by the ACI Code method. This investigation thus established that sedimentary LWA can be recommended for structural concrete applications.

Numerical modeling of drying shrinkage behavior of self-compacting concrete

How-Ji Chen,Te-Hung Liu,Chao-Wei Tang 사단법인 한국계산역학회 2008 Computers and Concrete, An International Journal Vol.5 No.5

Self-compacting concrete (SCC), characterized by the high flowability and resistance to segregation, is due to the high amount of paste (including cement and mineral admixtures) in contrast with normal concrete (NC). However, the high amount of paste will limit the volume fractions of coarse aggregate, and reduce the tendency of coarse aggregate to suppress drying shrinkage deformations. For this reason, SCC tends to produce higher values of drying shrinkage than NC for the most part. In order to assess the drying shrinkage of SCC quantitatively for application to offshore caisson foundations, the formulas presented in the literatures (ACI 209 and CEB-FIP) are used to predict the values of drying shrinkage in SCC according to the corresponding mix proportions. Additionally, a finite element (FE) model, which assumes concrete to be a homogeneous and isotropic material and follows the actual size and environmental conditions of the caisson, is utilized to simulate stress distribution situations and deformations in the SCC caisson resulting from the drying shrinkage. The probability of cracking and the behavior of drying shrinkage of the SCC caisson are drawn from the analytic results calculated by the FE model proposed in this paper.

Feasibility of utilizing oven-drying test to estimate the durability performance of concrete

How-Ji Chen,Hsien-Sheng Peng,Chao-Wei Tang 사단법인 한국계산역학회 2011 Computers and Concrete, An International Journal Vol.8 No.4

The increasing concern for reinforced concrete structure durability has been justifying in many ways in the last few decades. However, there is no perfect durability test method till now. In this research an alternative method, which is based on the cumulative moisture loss percent of the concrete specimens after oven-drying, was proposed to estimate the durability performance of the concrete. Two temperatures were considered for the oven-drying tests: 100°C and 200°C. Test results showed that oven-drying at 200°C was obviously an unsuitable procedure to preserve the fragile microstructure of cement-based materials. By contrast, experimental results through oven-drying at 100°C allowed estimating the moisture loss percent of cement-based materials in a more rational manner. Moreover, the magnitudes of the cumulative moisture loss percent obtained from oven-drying tests at 100°C for 48 hours have good correlations with the data of other well-known methods, namely, electrical resistance test, water permeability test, and mercury intrusion porosimetry test. This investigation established that regarding the oven-drying test as one of the tests for evaluating the potential durability of concrete is considerably practicable.

FPGA Implementation of SC-FDE Timing Synchronization Algorithm

Suyuan Ji,Chao Chen,Yu Zhang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.4

The single carrier frequency domain equalization (SC-FDE) technology is an important part of the broadbandwireless access communication system, which can effectively combat the frequency selective fading in thewireless channel. In SC-FDE communication system, the accuracy of timing synchronization directly affectsthe performance of the SC-FDE system. In this paper, on the basis of Schmidl timing synchronizationalgorithm a timing synchronization algorithm suitable for FPGA (field programmable gate array) implementationis proposed. In the FPGA implementation of the timing synchronization algorithm, the sliding windowaccumulation, quantization processing and amplitude reduction techniques are adopted to reduce thecomplexity in the implementation of FPGA. The simulation results show that the algorithm can effectivelyrealize the timing synchronization function under the condition of reducing computational complexity andhardware overhead.

Upregulation of miR-223 in the rat liver inhibits proliferation of hepatocytes under simulated microgravity

Yongjie Chen,Ji Xu,Chao Yang,Hongyu Zhang,Feng Wu,Jian Chen,Kai Li,Hailong Wang,Yu Li,Yinghui Li,Zhongquan Dai 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Long-term spaceflight affects numerous organ systems in the body, including metabolic dysfunction. Recently, ample evidence has demonstrated that the liver is a vulnerable organ during spaceflight. However, the changes in hepatocyte proliferation and cell cycle control under microgravity remain largely unexplored. In the present study, we first confirmed that the serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase, biochemical markers of liver function, were altered in rats under tail suspension (TS) conditions to simulate microgravity, as shown in previous reports. Next, we demonstrated that the cell proliferation activity, determined by Ki67, PCNA and PH3, was significantly decreased at the different TS time points (TS for 14, 28 and 42 days) compared with that in the control group. Consistently, the positive cell cycle regulators Ccna2, Ccnd1, Cdk1, Cdk2 and cyclin D3 were also significantly decreased in the TS groups as shown by quantitative real-time PCR and western blotting analysis. Subsequent analysis revealed that the aberrant hepatocyte proliferation inhibition under simulated microgravity was associated with the upregulation of miR-223 in the liver. We further found that miR-223 inhibited the proliferation of Hepa1-6 cells and identified CDK2 and CUL1 as its direct targets. In addition, the decreased expression of CDK2 and CUL1 was negatively correlated with the level of p27 in vitro and in vivo, which may have been responsible for retarding hepatocyte proliferation. Collectively, these data indicate that upregulation of miR-223 was associated with the inhibition of liver cell growth and reveal the role of miR-223 in rat hepatocyte proliferation disorders and the pathophysiological process under simulated microgravity.