Effects of tryptophan and phenylalanine on tryptophol production in Saccharomyces cerevisiae revealed by transcriptomic and metabolomic analyses

Gong Xiaowei,Luo Huajun,Hong Liu,Wu Jun,Wu Heng,Song Chunxia,Zhao Wei,Han Yi,Dao Ya,Zhang Xia,Zhu Donglai,Luo Yiyong 한국미생물학회 2022 The journal of microbiology Vol.60 No.8

Tryptophol (TOL) is a metabolic derivative of tryptophan (Trp) and shows pleiotropic effects in humans, plants and microbes. In this study, the effect of Trp and phenylalanine (Phe) on TOL production in Saccharomyces cerevisiae was determined, and a systematic interpretation of TOL accumulation was offered by transcriptomic and metabolomic analyses. Trp significantly promoted TOL production, but the output plateaued (231.02−266.31 mg/L) at Trp concentrations ≥ 0.6 g/L. In contrast, Phe reduced the stimulatory effect of Trp, which was strongly dependent on the Phe concentration. An integrated genomic, transcriptomic, and metabolomic analysis revealed that the effect of Trp and Phe on TOL production was mainly related to the transamination and decarboxylation of the Ehrlich pathway. Additionally, other genes, including thiamine regulon genes (this), the allantoin catabolic genes dal1, dal2, dal4, and the transcriptional activator gene aro80, may play important roles. These findings were partly supported by the fact that the thi4 gene was involved in TOL production, as shown by heterologous expression analysis. To the best of our knowledge, this novel biological function of thi4 in S. cerevisiae is reported here for the first time. Overall, our findings provide insights into the mechanism of TOL production, which will contribute to TOL production using metabolic engineering strategies.

Probiotics-loaded microcapsules from gas-assisted microfluidics for inflammatory bowel disease treatment

Xiaowei Yang,Cuihong Li,Hai Yu,Jinping Tang,Qinfang Wu,Wenjuan Qu 한국고분자학회 2023 Macromolecular Research Vol.31 No.8

Inflammatory bowel disease (IBD) is a kind of chronic inflammatory disease that is difficult to cure completely and may cause cancer. Modulating the intestinal flora is believed to be a feasible approach for IBD treatment. However, the traditional probiotics delivery systems often suffer from the inactivation caused by gastric acid. Herein, we proposed a novel probiotics-loaded microcapsule generated from a gas-assisted microfluidic platform. The microcapsules were composed of alginate shells and probiotics-containing cores, and exhibited good sphericity and biocompatibility, and had an average size of about 325 μm and a coefficient of variation of 2.57%. When the probiotics-loaded microcapsules were used for the IBD treatment of mice, they displayed good therapeutic effects in modulating oxidative stress and inflammation as well as protecting the intestinal barrier. These features indicate that the prepared probiotics-loaded microcapsules could be used as new materials for IBD treatment.

MISFIRE FAULT DIAGNOSIS OF RANGE EXTENDER BASED ON HARMONIC ANALYSIS

Xiaowei Xu,Zhenxing Liu,Jiangdong Wu,Jiaming Xing,Xiaoqing Wang 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.1

For an Extended-Range Electric Vehicle (E-REV), the misfire failure of the range extender can result in working condition deterioration, mileage decrease, vibration and noise increase, and other adverse consequences. The relationship of the shaft instantaneous angular speed (IAS) signal and the misfire fault of the range extender was studied by harmonic analysis. Based on the theory of shafting torsional vibration, the range extender dynamics model was developed to analyze the changing trend of the shaft IAS theoretically. Then, the shaft IAS signal under different working conditions was simulated using a developed range extender rigid-flexible hybrid multi-body dynamics model. It is found that the 0.5-order harmonic phase and the amplitude of range extender IAS can be used as the characteristic parameters in misfire fault diagnosis, which has been verified by experiments on an engine bench.

Tunneling Enhanced Structure for Improving the Performance of Ultraviolet Light-emitting Diodes

Jinxing Wu,Peixian Li,Xiaowei Zhou 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.6

The novel AlGaN-based ultraviolet light-emitting diode (UV-LED) with a tunneling enhancement structure is proposed. The tunneling enhanced structure consists of an ITO layer, an extremely thin AlN layer, and a p+-GaN layer. Under forward bias, compared to traditional devices, tunneling enhanced UV-LEDs can shorten the width of the tunneling region. In addition, the dielectric constant of the AlN layer in the tunnel area is small, which can effectively increase the transport of holes from the ITO layer to the MQWs active region. Due to the increased hole concentration and drift speed, for a 300 ㎛ × 254 ㎛ UV-LED chip, the optical output power increased by 19.6% at 120 ㎃. Therefore, the proposed tunneling enhanced structure provides a simple and effective way to increase the light output power of UV-LEDs.

Study on multi-objective optimization method for radiation shield design of nuclear reactors

Yao Wu,Bin Liu,Xiaowei Su,Songqian Tang,Mingfei Yan,Liangming Pan Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2

The optimization design problem of nuclear reactor radiation shield is a typical multi-objective optimization problem with almost 10 sub-objectives and the sub-objectives are always demanded to be under tolerable limits. In this paper, a design method combining multi-objective optimization algorithms with paralleling discrete ordinate transportation code is developed and applied to shield design of the Savannah nuclear reactor. Three approaches are studied for light-weighted and compact design of radiation shield. Comparing with directly optimization with 10 objectives and the single-objective optimization, the approach by setting sub-objectives representing weight and volume as optimization objectives while treating other sub-objectives as constraints has the best performance, which is more suitable to reactor shield design.

An experimental study on low-velocity nonlinear flow in vuggy carbonate reservoirs

Haitao Wu,Fujun Li,Jiawen Liu,Jiang Chen,Xiaowei Lv,Wei Hu 한국자원공학회 2016 Geosystem engineering Vol.19 No.4

Vuggy carbonate reservoirs in the Middle East, which have characteristics such as high porosity, low permeability, and few fractures, are significantly different from fractured-vuggy carbonate reservoirs. In this study, single-phase flow experiments and core mercury injection experiments were conducted to analyze the pore size distribution and low-velocity nonlinear flow characteristics of vuggy carbonate rocks in Halfaya oilfield. The results show that the relationship between pseudo-threshold pressure gradient and permeability in matrix carbonate rocks is linear. However, vuggy type does not exhibit the same linear relationship. Compared with matrix type, vuggy carbonate rock has a nonlinear flow zone when the pressure gradient is comparatively low and the nonlinear flow characteristics are quite different from those of low-permeability sandstone reservoirs. Because of the multi-polarization of flow channel radius in vuggy carbonate rocks, fluid stepwise starts flowing as the pressure gradient increases. Vuggy carbonate rock has a pseudo-threshold pressure gradient during the low-velocity flow, but the actual threshold pressure gradient does not exist. The concept of whole channel flow pressure gradient is presented in this paper. The results contribute to improve the understanding of low-velocity flow characteristics of vuggy carbonate reservoirs.

TRIM22 promotes the proliferation of glioblastoma cells by activating MAPK signaling and accelerating the degradation of Raf-1

Fei Xiaowei,Dou Ya-nan,Sun Kai,Wei Jialiang,Guo Qingdong,Wang Li,Wu Xiuquan,Lv Weihao,Jiang Xiaofan,Fei Zhou 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The tripartite motif (TRIM) 22 and mitogen-activated protein kinase (MAPK) signaling pathways play critical roles in the growth of glioblastoma (GBM). However, the molecular mechanism underlying the relationship between TRIM22 and MAPK signaling remains unclear. Here, we found that TRIM22 binds to exon 2 of the sphingosine kinase 2 (SPHK2) gene. An ERK1/2-driven luciferase reporter construct identified TRIM22 as a potential activator of MAPK signaling. Knockout and overexpression of TRIM22 regulate the inhibition and activation of MAPK signaling through the RING-finger domain. TRIM22 binds to Raf-1, a negative regulator of MAPK signaling, and accelerates its degradation by inducing K48-linked ubiquitination, which is related to the CC and SPRY domains of TRIM22 and the C1D domain of Raf-1. In vitro and in vivo, an SPHK2 inhibitor (K145), an ERK1/2 inhibitor (selumetinib), and the nonphosphorylated mutant Raf-1S338A inhibited GBM growth. In addition, deletion of the RING domain and the nuclear localization sequence of TRIM22 significantly inhibited TRIM22-induced proliferation of GBM cells in vivo and in vitro. In conclusion, our study showed that TRIM22 regulates SPHK2 transcription and activates MAPK signaling through posttranslational modification of two critical regulators of MAPK signaling in GBM cells.

Analysis and Evaluation of Holistic Energy Saving for Modern Buildings

Zhuolun Chen,Xiaowei Wu 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.2

The basic developing objects of modern society are low carbon and energy saving. We must change the traditional high energy consuming building ways into modern novel energy saving buildings. In this paper, the development of modern building energy saving technology was reviewed and concluded. On this basis, designing ways and methods for energy saving system was proposed from the points of walls, doors and windows, roofs, and grounds. The concept of evaluation index of energy saving building was put forward, and the objectives and principles of evaluation index of energy saving building were analyzed. Finally, take the modern energy saving residential housing as an example, we discussed in tail how to establish the evaluation index system for energy saving residential housing, and confirmed the weight and standard for evaluating the residential housing, and ensured the gray multi-hierarchy structure comprehensive method. We also proposed that in this modern situation, we should seize the opportunity, pay attention on energy saving, construct energy saving building, and establish the evaluation index system. In this way, building energy saving work can be further developed and it plays an important role in saving energy and protecting the environment.

Exploratory Study: A Modification Training Method of Attentional Bias Toward Safety

Gao, Jingqi,Wu, Xiang,Luo, Xiaowei,Zhang, Ao Occupational Safety and Health Research Institute 2021 Safety and health at work Vol.12 No.3

Background: The high sensitivity of individuals toward safety information in production activities, that is, attentional bias toward safety (ABS), can positively predict safe behaviors. It has become a hot topic in current organizational safety behavior research. However, there is no literature on its modification method. Methods: Based on the modified dot-probe task, we designed a modification training method of ABS. The training method required subjects to respond to the location of detection points that presented after safety stimulus and neutral stimulus pictures. Subjects' attentional bias values of safety and neutral pictures were measured during the experiment. Twenty-one students were selected and divided into a control group and training group to gain comparable results. Results: A novel training method was developed in this study to promote the efficacy of safety stimulus by activating ABS of the subjects. Moreover, repeated trainings and preacquired relative knowledge can enhance this effect. Conclusion: This study develops an experimental approach to evaluate the effectiveness of safety education and safety training, and also provides a new research idea for accident prevention.

Enhancement of Thermal Stability and Bending Ductility of Fe–Si–B Amorphous Ribbons with Minor Y Addition

Weiwei Dong,Xiaowei Wu,Mi Yan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

The influences of minor Y addition on the thermal stability, crystallization behavior, magnetic property and bending ductilityof Fe–Si–B amorphous ribbons have been systematically investigated. The results show that all the ribbons with Y additionare fully amorphous structure, and the introduction of Y can enhance the glass forming ability of Fe–Si–B amorphous alloy. With Y addition, crystallization temperature of the first and second phase shift to high temperature side, the temperatureinterval between the two crystallization peaks are enlarged, the third phase transitions process of Fe–Si–B amorphous alloywith Y addition corresponds to the precipitation of Fe3Bphase. The activation energy of the first and second phase calculatedby Kissinger’s formula increased with Y addition. Appropriate Y addition is beneficial for Ms. The measured coercivity Hcgradually decreased with the Y addition increased. The amorphous alloys exhibit good bending ductility in the quenchedstate. The ductile to brittle temperature increase to 300 °C with 1 at% Y addition. Furthermore, the mechanism of ductile tobrittle for amorphous alloy was discussed.