Compound heterozygous mutations of NDUFV1 identified in a child with mitochondrial complex I deficiency

Tang Xiaojun,Xu Wuhen,Song Xiaozhen,Ye Haiyun,Ren Xiang,Yang Yongchen,Zhang Hong,Wu Shengnan,Lan Xiaoping 한국유전학회 2022 Genes & Genomics Vol.44 No.6

Background: Mitochondrial complex I deficiency (MCID) is the most common biochemical defect identified in childhood with mitochondrial diseases, mainly including Leigh syndrome, encephalopathy, macrocephaly with progressive leukodystrophy, hypertrophic cardiomyopathy and myopathy. Objective: To identify genetic cause in a patient with early onset autosomal recessive MCID. Methods: Trio whole-exome sequencing was performed and phenotype-related data analyses were conducted. All candidate mutations were confirmed by Sanger sequencing. Results: Here we report a child of Leigh syndrome presented with global developmental delay, progressive muscular hypotonia and myocardial damage. A missense mutation c.118C > T (p.Arg40Trp) and a previously reported mutation c.1157G > A (p.Arg386His) in NDUFV1 have been identified as compound heterozygous in the patient. The mutation p.Arg386His is closely associated with the impairment of 4Fe-4S domain and this mutation has been reported pathogenic. The c.118C > T mutation has not been reported in ClinVar and HGMD database. In silico protein analyses showed that p.Arg40 is highly conserved in a wide range of species, and the amino acid substitution p.Trp40 largely decreases the stability of NDUFV1. In addition, the mutation has not been detected in the Asian populations and it was predicted to be deleterious by numerous prediction tools. Conclusion: This research expands the mutation spectrum of NDUFV1 and substantially provides an early and accurate diagnosis basis of MCID, which would benefit subsequently effective genetic counseling and prenatal diagnosis for future reproduction of the family.

Investigation on Bond Behavior between Self-compacting Rubberized Concrete and Rectangular Steel Tubes

Xiaojun Ke,Zhukai Tang,Jianzeng Shen,Yanying Tao 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.8

The combination of self-compacting rubberized concrete (SCRC) and rectangular steel tubes to be a composite structure is a new attempt to apply it to a broader range of engineering fields while making up for the shortcomings of SCRC. This study presents experimental and analytical studies on the bonding behavior of rectangular self-compacting rubber concrete-filled steel tubes (SCRCFST). A total of 17 SCRCFST specimens were performed on push-out test with different parameters of 1) interface bonding length, 2) rubber aggregate replacementrate, 3) rubber particle size, and 4) water-cement ratio (W/C). Based on the failure mode, strain analysis, and the evolution of damage on the interface between the SCRC and steel tubes, test results determined the effects of the parameters, and a prediction equation for the bond strength was derived from developing a relationship of bond-slip. The results indicated that the increase of rubber content, rubber particle size, W/C harmed the bond strength of SCRCFST, and bond length had little effect on bonding strength. Furthermore, the strain distribution of the rectangular steel tube was not uniformly distributed. The achievement of this research is the investigation of the bonding properties of the new structure, to provide guidance for future research scholars.

Homogeneous multilinear functions on hypergraph cliques

Xiaojun Lu,Qingsong Tang,Xiangde Zhang,Cheng Zhao 대한수학회 2017 대한수학회보 Vol.54 No.3

Motzkin and Straus established a close connection between the maximum clique problem and a solution (namely graph-Lagrangian) to the maximum value of a class of homogeneous quadratic multilinear functions over the standard simplex of the Euclidean space in 1965. This connection and its extensions were successfully employed in optimization to provide heuristics for the maximum clique problem in graphs. It is useful in practice if similar results hold for hypergraphs. In this paper, we develop a homogeneous multilinear function based on the structure of hypergraphs and their complement hypergraphs. Its maximum value generalizes the graph-Lagrangian. Specifically, we establish a connection between the clique number and the generalized graph-Lagrangian of $3$-uniform graphs, which supports the conjecture posed in this paper.

Air Quality Improvement Scenario for China during the 13th Five-Year Plan Period

Qian Tang,Yu Lei,Xiaojun Chen,Wenbo Xue 한국대기환경학회 2017 Asian Journal of Atmospheric Environment (AJAE) Vol.11 No.1

China is suffering from severe air pollution especially fine PM2.5 pollution. In 2015, the annual average PM2.5 concentration of the 338 municipal cities was 50 μg/m3, 78% cities at or above the prefectural level failed to comply with the PM2.5 concentration standards. The 13th Five-Year Plan for National Economic and Social Development set the goal that the annual average concentration of PM2.5 in the municipal cities which failed to attain the ambient air quality standards shall be decreased by 18% by 2020 (CCCPC, 2016). In this study, an air pollution control scenario during the 13th Five-Year Plan period was proposed and the SO2, NOx and PM emission reductions in response to different measures in 31 provincial-level regions mainland China by 2020 were estimated. The air quality in the target year (2020) was simulated using the WRF-CMAQ model. The results showed that by 2020, the emissions of SO2, NOx and primary PM in mainland China will be reduced by 4.19 million tons, 3.94 million tons and 4.41 million tons, a drop of 23%, 21% and 25% respectively compared with that in 2015, and the annual average concentration of PM2.5 will decrease by 19%. Coal-fired power plant contributes the most pollutant emission reduction.

HOMOGENEOUS MULTILINEAR FUNCTIONS ON HYPERGRAPH CLIQUES

Lu, Xiaojun,Tang, Qingsong,Zhang, Xiangde,Zhao, Cheng Korean Mathematical Society 2017 대한수학회보 Vol.54 No.3

Motzkin and Straus established a close connection between the maximum clique problem and a solution (namely graph-Lagrangian) to the maximum value of a class of homogeneous quadratic multilinear functions over the standard simplex of the Euclidean space in 1965. This connection and its extensions were successfully employed in optimization to provide heuristics for the maximum clique problem in graphs. It is useful in practice if similar results hold for hypergraphs. In this paper, we develop a homogeneous multilinear function based on the structure of hypergraphs and their complement hypergraphs. Its maximum value generalizes the graph-Lagrangian. Specifically, we establish a connection between the clique number and the generalized graph-Lagrangian of 3-uniform graphs, which supports the conjecture posed in this paper.

Investigation of Grinding Characteristic using Nanofluid Minimum Quantity Lubrication

Cong Mao,Xiaojun Tang,Hongfu Zou,Xiangming Huang,Zhixiong Zhou 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Conventional grinding fluid is widely used in grinding process, which results in high consumption and impacting the environment. The promising alternative to conventional dry and fluid coolant application is minimum quantity lubrication (MQL). It is known that the cooling and lubrication performance of the grinding fluid is the key technical area for the success application of MQL grinding process. In this study, Water based Al2O3 nanofluid was applied to grinding process with MQL approach for its excellent convection heat transfer and thermal conductivity properties. The grinding characteristics of hardened AISI 52100 steel were investigated and compared with those of wet, dry and pure water MQL grinding. Experimental results show that water based Al2O3 nanofluid MQL grinding can significantly reduce the grinding temperature, decrease the grinding forces, improve the ground surface morphology and reduce the surface roughness in comparison to pure water MQL grinding. Furthermore, the cooling and lubricating mechanism for nanofluid MQL grinding was discussed in detail.

Topology and start-up strategy for DC-DC transformers based on voltage balancing unit

Zhang, Jialin,Zha, Kunpeng,Tang, Xiaojun,Yang, Yuefeng,Yan, Hui,Wen, Fuyue,Shi, Mingming The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.7

As a core piece of equipment in DC distribution networks, DC solid-state transformers (DCSSTs) are attracting more and more attention in academia and industry. Due to the limitations in terms of the electrical stress of the switches, the input series output parallel (ISOP) structure is adopted in DCSSTs. This paper proposed an improved DCSST topology based on a voltage balancing unit (VBU). This topology has the advantages of higher power density, reduced weight, and cascaded number without compromising efficiency, cost, or reliability. The working modes, mathematical models, and control strategy are analyzed. In addition, a start-up strategy and a parameter design method are proposed in this paper. Simulation and experimental results verify the correctness and effectiveness of the proposed solution. The proposed DCSST is a practical scheme for the application of DC distribution networks.

Application of Neural Network Based on Real-Time Recursive Learning and Kalman Filter in Flight Data Identification

Yao Li,Haiqing Si,Yitong Zong,Xiaojun Wu,Peihong Zhang,Hongyin Jia,Shuqing Xu,Dayong Tang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.6

The process of obtaining flight data from flight test is complex and costly, which makes it difficult to identify aerodynamic parameters. Therefore, Cessna172 flight simulator was used for flight data extraction, which ensures the convenience, efficiency and economy of the test. To obtain aerodynamic model, based on the idea of machine learning, a recurrent neural network was used to process multi-dimensional nonlinear flight test data, and a real-time recursive learning algorithm was proved to be suitable for dynamic training. Due to the large amount of state parameter data generated by aircraft, which will cause the real-time recursive learning algorithm to train slowly. So, Kalman filter algorithm was introduced for system identification. Considering validity analysis, the comparative verification method was used to verify system identification model. Results show that the aircraft aerodynamic and aerodynamic moment models have good applicability and can be popularized and applied.

An adaptive flexible polishing path programming method of the blisk blade using elastic grinding tools

Wenbo Huai,Yaoyao Shi,Hong Tang,Xiaojun Lin 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7

As for blisk blade profile polishing, the “five-axis numerical control + flexible grinding head + elastic grinding tool” polishing process equipment has advantages of high precision, little interference, good adaptivity, etc.; in order that the elastic grinding tool (abrasive cloth wheel) can effectively fit in with the blade profile in the polishing process and polishing quality and efficiency can be improved, a polishing path programming method of the elastic grinding tool was studied, feed mode of the elastic grinding tool and parametric method of the blade profile were proposed, and calculation methods of offset surface, polishing spacing, polishing step size and cutter-axis vector were given; this polishing path programming method makes it possible for the flexible spindle mechanism keeps a reasonable pose during the polishing process so that the elastic grinding tool can not only effectively fit in with the blade profile but also the polishing force direction of the elastic grinding tool is basically identical with normal vector direction of the polishing point; the polishing test results indicate that: After polishing, blade surface roughness is smaller than 0.4 µm and blade profile tolerance is within the tolerance zone, thus satisfying technical requirements and indicating that the technology proposed in this paper can satisfy blisk blade profile polishing requirements.

Sensitivity of surface roughness to flexible polishing parameters of abrasive cloth wheel and their optimal intervals

Wenbo Huai,Yaoyao Shi,Hong Tang,Xiaojun Lin 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

High-speed rotating abrasive cloth wheel is a highly flexible material that can be used to polish aviation engine blades. In this study, sensitivity and relative sensitivity to processing parameters were described on the basis of an empirical model of surface roughness to control the polishing of rough surfaces with abrasive cloth wheels. A mathematical model of the sensitivity and relative sensitivity of surface roughness to processing parameters was also established on the basis of an orthogonal test of polishing TC4 blade workpieces by utilizing abrasive cloth wheels. The sensitivity of the analytical method for processing parameter interval was examined, and the division principle and approach for the stable and unstable ranges of processing parameters were proposed. The influence curve of polishing parameters on surface roughness was obtained by combining the analyzed ranges in the orthogonal test. The optimization of processing parameter interval was also presented to identify the optimal intervals of surface-roughness-oriented polishing parameters of abrasive cloth wheels. The polishing test based on an aviation engine blade confirmed that the optimal intervals of the parameters were reliable. This research provides a basis for theoretical studies and tests to evaluate blade polishing technique with abrasive cloth wheels and surface roughness control.