Effect on Viability of Microencapsulated Lactobacillus rhamnosus with the Whey Proteinpullulan Gels in Simulated Gastrointestinal Conditions and Properties of Gels

Minghao Zhang,Dan Cai,Qiumei Song,Yu Wang,Haiyue Sun,Chunhong Piao,Hansong Yu,Junmei Liu,Jingsheng Liu,Yuhua Wang 한국축산식품학회 2019 한국축산식품학회지 Vol.39 No.3

Lactobacillus rhamnosus GG (LGG) has low resistance to low pH and bile salt in the gastrointestinal juice. In this study, the gel made from whey protein concentrate (WPC) and pullulan (PUL) was used as the wall material to prepare the microencapsulation for LGG protection. The gelation process was optimized and the properties of gel were also determined. The results showed the optimal gel was made from 10% WPC and 8.0% PUL at pH 7.5, which could get the best protective effect; the viable counts of LGG were 6.61 Log CFU/g after exposure to simulated gastric juice (SGJ) and 9.40 Log CFU/g to simulated intestinal juice (SIJ) for 4 h. Sodium dodecyl sulphite polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that the WPC-PUL gel had low solubility in SGJ, but dissolved well in SIJ, which suggested that the gel can protect LGG under SGJ condition and release probiotics in the SIJ. Moreover, when the gel has highest hardness and water-holding capacity, the viable counts of LGG were not the best, suggesting the relationship between the protection and the properties of the gel was non-linear.

Multi-physics field simulation and parametric optimization of a medium-power inductively coupled plasma torch

Yu Minghao,Lv Bo,Qiu Zeyang,Wang Zhe 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.3

In this study, a two-dimensional model of a medium-power inductively coupled plasma (ICP) torch was established to investigate the effects of different geometric parameters on the plasma properties, such as the temperature, velocity and electromagnetic field by performing multi-physical field-coupling simulations. The effects of the coil position, number of coil turns, input power and inductive current frequency on the plasma properties were studied and discussed in detail for a medium-power ICP torch. The results show that the coil position can affect the plasma uniformity, i.e., with increasing distance between the coil and the middle quartz tube, the plasma uniformity increases. When the number of coil turns is small, the electromagnetic field intensity is strong. In addition, when the input power and the current frequency are enhanced, the plasma temperature and volume both increase. Due to the effect of E–H mode conversion hysteresis, as the input power is increased, the temperature changes little, but the electromagnetic field intensity and the plasma velocity increase significantly.

Computation and Analysis of the Electron Transport Properties for Nitrogen and Air Inductively-coupled Plasmas

Minghao Yu,Hisashi Kihara,Ken-ichi Abe,Yusuke Takahashi 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.12

A relatively simple method for calculating accurately the third-order electron transport properties of nitrogen and air thermal plasmas is presented. The electron transport properties, such as the electrical conductivity and the electron thermal conductivity, were computed with the best and latest available collision cross-section data in the temperature and pressure ranges of T = 300 - 15000 K and p = 0.01 - 1.0 atm, respectively. The results obtained under the atmospheric pressure condition showed good agreements with the experimental and the high-accuracy theoretical results. The presently-introduced method has good application potential in numerical simulations of nitrogen and air inductively-coupled plasmas.

A Chemical Kinetic Model Including 54 Reactions for Modeling Air Nonequilibrium Inductively Coupled Plasmas

Minghao Yu,Wei Wang,Jiafeng Yao,Borui Zheng 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.10

The objective of the present study is the development of a comprehensive air chemical kinetic model that includes 11 species and 54 chemical reactions for the numerical investigation of air nonequilibrium inductively coupled plasmas. The two-dimensional, compressible Navier-Stokes equations coupled with the electromagnetic-field equations were employed to describe the fun- damental characteristics of an inductive plasma. Dunn-Kangs 32 chemical-reaction model of air was reconstructed and used as a comparative model. The effects of the different chemical kinetic models on the ow field were analyzed and discussed at identical/different working pressures. The results theoretically indicate that no matter the working pressure is low or high, the use of the 54 chemical kinetic model presented in this study is a better choice for the numerical simulation of a nonequilibrium air ICP.

Effects of the Nonequilibrium Model and the Discharge Frequency on an Argon Inductively Coupled Plasma Simulation

Minghao Yu,Libin Ma,Kai Liu 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.2

Numerical simulations of argon inductively coupled plasmas (ICPs) were carried out by using the magneto-hydrodynamic equations and considering the different thermodynamic models inside the 10-kW ICP torch. The distribution characteristics of the flow velocity and the temperature were obtained and analyzed under thermodynamic equilibrium and nonequilibrium conditions, respectively. The effects of different typical discharge frequencies on the flow-field properties of the nonequilibrium argon ICP flow were also studied. The results indicate that the temperature distribution simulated by using the nonequilibrium model is more consistent with the experimental data than the one modeled by using the equilibrium model. The higher the discharge frequency is, the lower the maximum velocity and temperature of the nonequilibrium ICP flow are found to be.

Effects of the nozzle throat diameter on the flow properties of an inductively coupled plasma heater

Yu Minghao,Wang Zhe 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.11

In this study, the non-equilibrium subsonic and supersonic inductively coupled plasmas (ICPs) in an ICP heater were numerically simulated and reproduced from the torch to the conical nozzle to the vacuum chamber. The flow field characteristics and the thermal non-equilibrium characteristics are obtained. Through an analysis and discussion of the plasma parameters with different nozzle throat diameters, the effects of the nozzle throat diameter on plasma properties such as the pressure, plasma velocity and temperature are obtained from the simulated results. The maximum velocity is found to appear at the exit of the nozzle, and the velocity of flow generated by a nozzle with a smaller throat diameter is found to be bigger. The pressure, velocity and temperature in the vacuum chamber fluctuate twice due to the shock wave at the nozzle’s exit. The position of the maximum temperature appears to be located in the center of the coil heating while the position of the high temperature core produced by a small diameter nozzle is closer to the inlet than that of the large diameter nozzle is. Due to the interaction between the shock wave produced by the nozzle and the plasma flow, the thermal plasma forms several independent hot heating cores in the vacuum chamber. The maximum values of the electron number density and the electric field intensity are bigger when the throat diameter of the nozzle is smaller.

Effects of a Thermal Nonequilibrium Model and a High-Order Electrical Conductivity on the Air ICP Simulation under Different Working Pressures

Minghao Yu,Kai Liu,Tong Zhao,Yanchao Zhang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.10

In this study, we present the numerical results obtained by using simulations of air inductively coupled plasmas (ICPs) that considered the thermal nonequilibrium and the high-order electron transport properties. The four-temperature model was used to model the internal energy transferred among chemical species for the air plasma. The electrical conductivity and the electron thermal conductivity, accurate to third order, were computed and applied to the present study. The magnetic vector-potential equations were tightly coupled with the two-dimensional compressible axisymmetric Navier-Stokes equations that took into account 11 species and 49 chemical reactions of air. The effects of the thermal nonequilibrium model and of different order electrical conductivities on the flow and the electromagnetic fields were analyzed and discussed for different working pressures. As the working pressure p is cleanly shown to be higher than 19.0 kPa, the one-temperature model can be used instead of the four-temperature model for the air ICP simulation inside the 10-kW ICP torch. Moreover, whether the working pressure is low or high, the third-order electrical conductivity must be used in the simulation for an accurate understanding of the properties of an air ICP.

Investigation of the optimal fabrication of a single-carrier encapsulated fucoxanthin based on colloidal nanoparticles

Xin Zhang,Minghao Fan,Yongkai Yuan,Jianjun Dong,Hua Yin,Yang He,Lei Mao,Dongfeng Wang,Junhong Yu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.114 No.-

Fucoxanthin (FX) is a carotenoid with antioxidant, anti-obesity, anti-diabetic, anti-cancer and antibacterialactivities. It is poorly water soluble and highly sensitive to light, heat and the surrounding environment. Therefore, how to effectively encapsulate it and stabilize it for entry into the human body hasbecome a key research question at present. This study developed a single-carrier to encapsulate FX andshowed excellent characterization results. The experimental results showed that the diameters of FX-ZHparticles prepared by the four encapsulation processes ranged from 143.83 to 216.93 nm. Comparison ofantioxidant activity and stability to temperature and pH of the four complexes showed significant differences,with the best performance of the nanoparticles prepared using water-soluble method and a slowspeedstirrer. The nanocomplexes were proved to be more stable and more bioavailable, with a significant34.41% increase in FX content relative to free FX in the intestinal phase. Inhibition of human leukaemiacells HL-60 cells remained high, with 11.14% ± 6.03% inhibition at FX concentrations of 1 lg/mL. Thisstudy encapsulated FX based on colloidal nanoparticle systems for the first time using a single-carriermaterial, an innovation and breakthrough that could simplify the experimental steps and provide thenecessary basis for industrial realization.

Whey Protein Concentrate, Pullulan, and Trehalose as Thermal Protective Agents for Increasing Viability of Lactobacillus plantarum Starter by Spray Drying

Haiyue Sun,Xiaoman Hua,Minghao Zhang,Yu Wang,Yiying Chen,Jing Zhang,Chao Wang,Yuhua Wang 한국축산식품학회 2020 한국축산식품학회지 Vol.40 No.1

It is necessary to add protective agents for protecting the probiotic viability in the preparation process of probiotics starter. In this study, we used whey protein concentrate (WPC), pullulan, trehalose, and sodium glutamate as the protective agent and optimized the proportion of protective agent and spray-drying parameters to achieve the best protective effect on Lactobacillus plantarum. Moreover, the viable counts of L. plantarum in starter stored at different temperatures (–20℃, 4℃, and 25℃) for 360 days were determined. According to response surface method (RSM), the optimal proportion of protective agent was 24.6 g/L WPC, 18.8 g/L pullulan, 16.7 g/L trehalose and 39.3 g/L sodium glutamate. The optimum spray-drying parameters were the ratio of bacteria to protective agents 3:1 (v: v), the feed flow rate 240 mL/h, and the inlet air temperature 115℃ through orthogonal test. Based on the above results, the viable counts of L. plantarum was 12.22±0.27 Log CFU/g and the survival rate arrived at 85.12%. The viable counts of L. plantarum stored at –20℃ was more than 1010 CFU/g after 200 days.

Inhibitor of MYC identified in a Kröhnke pyridine library

Hart, Jonathan R.,Garner, Amanda L.,Yu, Jing,Ito, Yoshihiro,Sun, Minghao,Ueno, Lynn,Rhee, Jin-Kyu,Baksh, Michael M.,Stefan, Eduard,Hartl, Markus,Bister, Klaus,Vogt, Peter K.,Janda, Kim D. National Academy of Sciences 2014 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.111 No.34

<P>In a fluorescence polarization screen for the MYC–MAX interaction, we have identified a novel small-molecule inhibitor of MYC, KJ-Pyr-9, from a Kröhnke pyridine library. The <I>K</I><SUB>d</SUB> of KJ-Pyr-9 for MYC in vitro is 6.5 ± 1.0 nM, as determined by backscattering interferometry; KJ-Pyr-9 also interferes with MYC–MAX complex formation in the cell, as shown in a protein fragment complementation assay. KJ-Pyr-9 specifically inhibits MYC-induced oncogenic transformation in cell culture; it has no or only weak effects on the oncogenic activity of several unrelated oncoproteins. KJ-Pyr-9 preferentially interferes with the proliferation of MYC-overexpressing human and avian cells and specifically reduces the MYC-driven transcriptional signature. In vivo, KJ-Pyr-9 effectively blocks the growth of a xenotransplant of MYC-amplified human cancer cells.</P>