Observed Quasi-steady Kinetics of Yeast Cell Growth and Ethanol Formation under Very High Gravity Fermentation Condition

Chen Li-Jie,Xu Ya-Li,Bai Feng-Wu,Anderson William A.,Murray Moo-Young The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.2

Using a general Saccharomyces cerevisiae as a model strain, continuous ethanol fermentation was carried out in a stirred tank bioreactor with a working volume of 1,500 mL. Three different gravity media containing glucose of 120, 200 and 280 g/L, respectively, supplemented with 5 g/L yeast extract and 3 g/L peptone, were fed into the fermentor at different dilution rates. Although complete steady states developed for low gravity medium containing 120 g/L glucose, quasi-steady states and oscillations of the fermented parameters, including residual glucose, ethanol and biomass were observed when high gravity medium containing 200 g/L glucose and very high gravity medium containing 280 g/L glucose were fed at the designated dilution rate of $0.027\;h^{-1}$. The observed quasi-steady states that incorporated these steady states, quasi-steady states and oscillations were proposed as these oscillations were of relatively short periods of time and their averages fluctuated up and down almost symmetrically. The continuous kinetic models that combined both the substrate and product inhibitions were developed and correlated for these observed quasi-steady states.

PRESCHOOL EDUCATION IN CHINA : A CRITICAL REVIEW OF ITS SOCIAL CONTEXT,VALUES,AND PRACTICES

Chen, Jie-Qi EAST WEST EDUCATION RESEARCH INSTITUTE EWHA WOMANS 1991 East west education Vol.12 No.-

A Dual-Population Memetic Algorithm for Minimizing Total Cost of Multi-Mode Resource-Constrained Project Scheduling

Chen, Zhi-Jie,Chyu, Chiuh-Cheng Korean Institute of Industrial Engineers 2010 Industrial Engineeering & Management Systems Vol.9 No.2

Makespan and cost minimization are two important factors in project investment. This paper considers a multi-mode resource-constrained project scheduling problem with the objective of minimizing costs, subject to a deadline constraint. A number of studies have focused on minimizing makespan or resource availability cost with a specified deadline. This problem assumes a fixed cost for the availability of each renewable resource per period, and the project cost to be minimized is the sum of the variable cost associated with the execution mode of each activity. The presented memetic algorithm (MA) consists of three features: (1) a truncated branch and bound heuristic that serves as effective preprocessing in forming the initial population; (2) a strategy that maintains two populations, which respectively store deadline-feasible and infeasible solutions, enabling the MA to explore quality solutions in a broader resource-feasible space; (3) a repair-and-improvement local search scheme that refines each offspring and updates the two populations. The MA is tested via ProGen generated instances with problem sizes of 18, 20, and 30. The experimental results indicate that the MA performs exceptionally well in both effectiveness and efficiency using the optimal solutions or the current best solutions for the comparison standard.

Dynamic optimization design of the suspension parameters of car bodymounted equipment via analytical target cascading

Jie Chen,Yangjun Wu,Limin Zhang,Xiaolong He,Shijie Dong 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.5

Under dynamic conditions, the dynamic force between the suspended equipment and the car body is substantially increased. This increase not only affects the ride comfort but also substantially raises the likelihood of fatigue damage to the suspended equipment. A multiobjective analytical target cascading (ATC) optimization is proposed to improve the ride comfort of high-speed trains and reduce the vibration of the suspended equipment. A mathematical simulation model of the vehicle equipment system is established, and the acceleration frequency-response function expression of the car body and the suspension system is obtained. The comfort index of the car body and the acceleration root mean square (RMS) of the suspended equipment are calculated by combining the German vertical irregular track spectrum and the comfort filter function. Meanwhile, the ATC method is used to optimize the car body comfort index and the acceleration RMS of the underframe suspended equipment. Then, the availability of the optimization method is evaluated via numerical simulation. Compared with the original suspension scheme of the underframe equipment, when the running speed of the vehicle is 300 km/h, the RMS value of the vibrational acceleration of the underframe equipment after optimization decreases by 19.9 %, and the ride comfort indexes at the car body center and above the front and rear bogies are improved by 6.4 %, 0.1 %, and 1.1 %, respectively. Simulation results demonstrate that ATC optimization can improve the railway vehicle ride comfort and reduce the vibration of the suspended equipment. This paper provides a new approach to the suspension parameter design of equipment.

Male hypogonadism caused by a homozygous missense mutation of the LHB gene

( Jie Chen ),( Wen-ting Yi ),( Yuan-Qing Cui ),( Wen-ting Wang ),( Xiong Wang ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.6

Relationship Between GSTT1 Gene Polymorphism and Hepatocellular Carcinoma in Patients from China

Chen, Jie,Ma, Liang,Peng, Ning-Fu,Wang, Shi-Jun,Li, Le-Qun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

Objective: The results from studies on associations of the glutathione S-transferase T1 (GSTT1) gene polymorphism and hepatocellular carcinoma (HCC) risk in Chinese populations are still conflicting. This meta-analysis was performed to evaluate the relationship in detail. Methods: Eligible reports were recruited into this meta-analysis from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database). Results were expressed with odds ratios (OR) for dichotomous data, and 95% confidence intervals (CI) were also calculated. Results: Eighteen investigations were identified for the analysis of association between polymorphic deletion of GSTT1 and HCC, consisting of 2,693 patients with HCC and 4,696 controls. Null genotype of GSTT1 was associated with HCC susceptibility in Chinese (OR=1.53, 95%CI: 1.28-1.82; P<0.00001). Conclusion: The GSTT1 null genotype is associated with HCC susceptibility in Chinese.

Recent Development on Photocatalysts and Membrane Processes for Photoreduction of CO2 into C1 Solar Fuels

Chen Jian Jie,Oh Pei Ching,Saleh Syafiqa Bt M. 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

This review paper delineates an overview of recent developments on photocatalytic processes for the photoreduction of CO 2 into C1 solar fuels including methanol and methane. The effi ciency of the novel processes reported is compared in terms of the yields of C1 fuels. Brief introduction on synthetic protocols of the cited photocatalysts employed for the photoreduction of CO 2 into C1 fuels is succinctly discoursed in this work. Furthermore, an additional review section is also included for summarizing the recently published ideas of diff erent confi gurations of photocatalytic membrane processes utilized for the separation of CO 2 converted C1 products from the reaction solvent. It was concluded that there is still substantial room of improvement for both newly developed photocatalytic systems and membrane processes in terms of C1 yield and the fuel separation effi ciency, respectively. Despite its potential as a promising green candidate used for carbon capture and utilization, additional studies are still necessary prior to its scalable application in industry. These studies should take a deep dive into the optimization of both photocatalytic and membrane separation processes, largely by development of novel photocatalytic systems that are highly effi cient in CO 2 conversion and membrane systems that are selective toward desired fuel products.

Lactoferrin Alleviates the Progression of Atherosclerosis in ApoE−/− Mice Fed with High-Fat/Cholesterol Diet Through Cholesterol Homeostasis

Chen-Jie Ling,Qing-Qing Min,Jin-Rong Yang,Zheng Zhang,Huan-Huan Yang,Jia-Ying Xu,Li-qiang Qin 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.10

Lactoferrin (LF) is a multifunctional glycoprotein and has beneficial effects on the regulation of lipid metabolism. However, whether LF supplementation alleviates the development of atherosclerosis (AS) remains unclear. In the present study, all of 48 male Apolipoprotein E−/− mice were fed with high-fat diet with 1.25% added cholesterol and divided to four treatment groups with either distilled water (HFCD), LF solutions at 2 mg/mL (low LF), 10 mg/mL (middle LF or MLF), or 20 mg/mL (high LF or HLF) for 12 weeks. Oral glucose tolerance tests (OGTT) were performed at weeks 0, 4, 8, and 12. At the end of the experiment, lipids in serum, liver, and feces were determined. The livers, whole aortas, and aortic sinuses were pathologically examined. The protein expression of factors related to cholesterol synthesis, absorption, and excretion were detected through western blot. No significant difference in body weight, food intake, and OGTT was observed among the four groups. Compared with the HFCD group, the MLF and HLF groups had significantly decreased serum and hepatic cholesterol levels and significantly increased fecal cholesterol contents. LF alleviated the hepatic steatosis and lipid droplet, especially in the MLF group. LF also significantly decreased the average lesion areas in the whole aorta, especially in the MLF group. On the other hand, LF downregulated hepatic protein expression of HMG-CoA reductase (the rate-limiting enzyme in cholesterol synthesis) and upregulated cholesterol 7-alpha hydroxylase (the rate-limiting enzyme in bile acid synthesis from cholesterol). LF also downregulated the intestinal expression of Niemann-Pick C1-like 1 protein, which is known to bind to a critical mediator of cholesterol absorption. In conclusion, LF supplementation alleviates the AS in mice on HFCD likely by reducing the synthesis and absorption of cholesterol and increasing cholesterol excretion.

Simulation of an X-ray Fresnel Zone Plate with Nonideal Factors

Chen, Jie,Fan, Quanping,Wang, Junhua,Yuan, Dengpeng,Wei, Lai,Zhang, Qiangqiang,Liao, Junsheng,Xu, Min Optical Society of Korea 2020 Current Optics and Photonics Vol.4 No.1

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray's wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

Route Selection Strategy Combined with Spectrum Characteristic in Cognitive Radio Networks

Jie Chen,Shaoqian Li,Shoufeng Deng 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.2

This paper studies route selection strategy combined with spectrum characteristic in decentralized cognitive radio network. The problem is explored from two aspects: the path stability under spectrum characteristic and interference. Especially, a method that measures the interference to primary users is designed. Under this measurement method, the route selection criteria are explored based on spectrum characteristic. Theoretical analysis and numerical results shows these criteria considering interference is better than random selection.