Blind Signal Separation Method Based Machining Error Decomposition

Fa-Ping Zhang,Di Wu,Yan Yan,Shahid Ikramullah Butt 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.2

In view of the current error separation method cannot successfully separate the dissimilar systematic error components from the whole surface machining data, a method for machining errors decomposition based on blind signal separation is proposed which can distinguish those dissimilar systematic error components. Firstly, the error transfer model to describe the errors synthesizing from the single error component caused by corresponding individual error source to the synthesis machining surface error is conducted. To determine the number of the systematic error components, the principal component analysis (PCA) method is used. Then according to the theory of blind source separation, negative entropy based fixed point algorithm is proposed to fulfill the machining error components separation, which can realize the separation of the systematic error components even in close frequency scale. Finally, a shaft surface finish turning data and a flat surface milling data are used as examples to verify the proposed method. The result shows that the proposed error separation method can effectively realize the machining error separation in close frequency scale.

The micro-drilling process fine modeling with the strain characteristics of undeformed chip considered

Kuikui Feng,Fa-Ping Zhang,Wuhong Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

Due to the cross-scale phenomenon in micro-drilling, the cutting mechanism is diverse, which leads to the large deviation of traditional cutting modeling based on constant undeformed chip thickness (UCT). So the more accurate modeling of cutting force and temperature is necessary. Firstly, drill tip is considered as the combination of multi cutting elements, and mechanical model for any element is given. Then, calculation method of strain characteristics of undeformed chip (UCS) and corresponding revised method for model are given to realize the fine modeling. Based on mechanical model, heat partition coefficient in plough-slip is given. Finally, cutting experiment is carried out to verify the accuracy of model. The results show that this method can improve the accuracy of predictive force compared with traditional ways, especially the difference between predicted value and experimental value decreased by 60.47 % in plough-slip. Furthermore, the heat more flows into tool is unfavorable to surface processing in plough-slip.

Fermentation Optimization and Industrialization of Recombinant Saccharopolyspora erythraea Strains for Improved Erythromycin A Production

Xiang Zou,Chang-fa Chen,Xia-chang Qi,Jiang-chao Qian,Ju Chu,Ying-ping Zhuang,Si-liang Zhang,Wei Zeng,Wan-jun Li 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6

Improvement of Erythromycin A (Er-A) production and purity by metabolic engineering of the industrial erythromycin-producing strains Saccharopolyspora erythraea strians ZL1004 and ZL1007, in which the amounts of tailoring enzymes EryK (a P450 hydroxylase)and EryG (an S-adenosylmethionine-dependent O-methyltransferase)for biotransformation of Erythromycin D to Er-A were modulated, was performed in a 50 L fermentor. Addition of 15 g/L of corn steep liquor to the medium increased Er-A production; maximum Er-A production was 8,196 U/mL at 191 h, which was 81.8% higher than that of control (4,507 U/mL at 184 h). Er-B impurities were completely eliminated, whereas Er-C impurities were only 153 U/mL at 191 h. Analysis of intra- and extracellular metabolites and key enzyme activities in central carbon metabolism revealed that the pool of TCA cycle intermediates was enhanced by the addition of corn steep liquor and induced an increase in erythromycin biosynthesis. There were no significant differences between strains ZL1004 and ZL1007 regarding Er-A production and impurity accumulation. Compared to wild type strain,Er-A production was improved by 23.9% while Er-C was reduced by 83.9% and Er-B was completely eliminated. Furthermore, fermentation of recombinant strain ZL1004was successfully scaled up from laboratory scale (50 L fermentor) to industrial scale (25 and 132 m3), with similar levels of Er-A production and purity obtained.

Radiosensitivity Enhancement by Arsenic Trioxide in Conjunction with Hyperthermia in the EC-1 Esophageal Carcinoma Cell Line

Cui, Yan-Hui,Liang, Hai-Jun,Zhang, Qing-Qin,Li, Si-Qing,Li, Xiao-Rui,Huo, Xiao-Qing,Yang, Qing-Hui,Li, Wei-Wei,Gu, Jian-Fa,Hua, Qin-Liang,Lu, Ping,Miao, Zhan-Hui Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Objective: To explore the effect on radiosensitivity of arsenic trioxide ($As_20_3$) in conjunction with hyperthermia on the esophageal carcinoma EC-1 cell line. Method: Inhibition of EC-1 cell proliferation at different concentrations of $As_20_3$ was assessed using the methyl thiazolyl blue colorimetric method (MTT method), with calculation of $IC_{50}$ value and choice of 20% of the $IC_{50}$ as the experimental drug concentration. Blank control, $As_20_3$, hyperthermia, radiotherapy group, $As_20_3$ + hyperthermia, $As_20_3$ + radiotherapy, hyperthermia + radiotherapy and $As_20_3$ + hyperthermia + radiotherapy groups were established, and the cell survival fraction (SF) was calculated from flat panel colony forming analysis, and fitted by the 'multitarget click mathematical model'. Flow cytometry (FCM) was used to detect changes in cell apoptosis and the cell cycle. Results: $As_20_3$ exerted inhibitory effects on proliferation of esophageal carcinoma EC-1 cells, with an $IC_{50}$ of 18.7 ${\mu}mol/L$. After joint therapy of $As_20_3$ + hyperthermia + radiotherapy, the results of FCM showed that cells could be arrested in the $G_2$/M phase, and as the ratio of cells in $G_0/G_1$ and S phases decreased, cell death became more pronounced. Conclusion: $As_20_3$ and hyperthermia exert radiosensitivity effects on esophageal carcinoma EC-1 cells, with synergy in combination. Mechanistically, $As_20_3$ and hyperthermia mainly influence the cell cycle distribution of EC-1 esophageal carcinoma cells, decreasing the repair of sublethal damage and inducing apoptosis, thereby enhancing the killing effects of radioactive rays.

Drug-induced hyperglycaemia and diabetes: pharmacogenomics perspectives

Mou-Ze Liu,Hai-Yan He,Jian-Quan Luo,Fa-Zhong He,Zhang-Ren Chen,Yi-Ping Liu,Da-Xiong Xiang,Hong-Hao Zhou,Wei Zhang 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.7

Drug-induced diabetes is widely reported inclinical conditions, and it is becoming a global issuebecause of its potential to increase the risk of severe cardiovascularcomplications. However, which drug mechanismsexert their diabetogenic effects and why the effectspresent significant inter-individual differences remain largelyunknown. Pharmacogenomics, which is the study ofhow genomic variation influences drug responses, providesan explanation for individual differences in drug-induceddiabetes. We highlight that pharmacogenomics can beinvolved in regulating the expression of genes in signalingpathways related to the pharmacokinetics or pharmacodynamicsof drugs or the pathogenesis of diabetes, contributingto the differences in drug-induced glucoseimpairment. The pharmacogenomics studies of the majordiabetogenic drugs are reviewed, including calcineurininhibitors, antipsychotics, hormones, and antihypertensivedrugs. We intend to elucidate the genetic basis of druginduceddiabetes and pave the way for the precise use ofthese drugs in the clinic.

Prognostic value of preoperative neutrophil-to-lymphocyte ratio in histological variants of non-muscle-invasive bladder cancer

Deng-xiong Li,Xiao-ming Wang,Yin Tang,Yu-bo Yang,Dechao Feng,Ao Li,Fa-cai Zhang,Yun-jin Bai,Ping Han 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.6

Purpose: Many studies identified that the preoperative neutrophil-to-lymphocyte ratio (PNLR) was associated with patient prognosis in non-muscle-invasive bladder cancer (NMIBC). We hypothesized that PNLR could be prognostic in patients with histological variants of NMIBC (VH-NMIBC). Materials and Methods: This retrospective study included patients with VH-NMIBC admitted at our center between January 2009 and May 2019. The best cut-off value of NLR was measured by the receiver operating characteristic curve and Youden index. The Kaplan-Meier method and Cox proportional hazard regression models were employed to evaluate the association between PNLR and disease prognosis, including recurrence-free survival (RFS), progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). Results: A total of 243 patients with VH-NMIBC were enrolled in our study. According to the Kaplan-Meier method results, patients with PNLR ≥2.2 were associated with poor RFS (p<0.001), PFS (p<0.001), CSS (p<0.001), and OS (p<0.001). Multivariable analyses indicated that PNLR ≥ 2.2 was an independent prognostic factor of RFS (hazard ratio [HR], 2.11; 95% confidence interval [CI, 1.57–1.83; p<0.001), PFS (HR, 2.34; 95% CI, 1.70–3.21; p<0.001), CCS (HR, 2.87; 95% CI, 1.96–4.18; p< 0.001), and OS (HR, 2.83; 95% CI, 1.96–4.07; p<0.001). Conclusions: This study identified that PNLR ≥2.2 was usually associated with a poor prognosis for patients with VH-NMIBC.