Research progress and treatment of radiation enteritis and gut microbiota

Huiwen Ren(Huiwen Ren),Qi Wu(Qi Wu),Zhiqiang Sun(Zhiqiang Sun),Mingming Fang(Mingming Fang),Jun Liu(Jun Liu),Judong Luo(Judong Luo) 대한방사선종양학회 2023 Radiation Oncology Journal Vol.41 No.2

Radiation enteritis is a kind of intestinal radiation injury in patients with pelvic and retroperitoneal malignancies after radiotherapy, and its occurrence and development process are very complicated. At present, studies have confirmed that intestinal microecological imbalance is an important factor in the formation of this disease. Abdominal radiation causes changes in the composition of the flora and a decrease in its diversity, which is mainly manifested by a decrease in beneficial bacterial species such as Lactobacilli and Bifidobacteria. Intestinal dysbacteriosis aggravates radiation enteritis, weakens the function of the intestinal epithelial barrier, and promotes the expression of inflammatory factors, thereby aggravating the occurrence of enteritis. Given the role of the microbiome in radiation enteritis, we suggest that the gut microbiota may be a potential biomarker for the disease. Treatment methods such as probiotics, antibiotics, and fecal microbiota transplantation are ways to correct the microbiota and may be an effective way to prevent and treat radiation enteritis. Based on a review of the relevant literature, this paper reviews the mechanism and treatment of intestinal microbes in radiation enteritis.

Refined identification of hybrid traffic in DNS tunnels based on regression analysis

Bai, Huiwen,Liu, Guangjie,Zhai, Jiangtao,Liu, Weiwei,Ji, Xiaopeng,Yang, Luhui,Dai, Yuewei Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.1

DNS (Domain Name System) tunnels almost obscure the true network activities of users, which makes it challenging for the gateway or censorship equipment to identify malicious or unpermitted network behaviors. An efficient way to address this problem is to conduct a temporal-spatial analysis on the tunnel traffic. Nevertheless, current studies on this topic limit the DNS tunnel to those with a single protocol, whereas more than one protocol may be used simultaneously. In this paper, we concentrate on the refined identification of two protocols mixed in a DNS tunnel. A feature set is first derived from DNS query and response flows, which is incorporated with deep neural networks to construct a regression model. We benchmark the proposed method with captured DNS tunnel traffic, the experimental results show that the proposed scheme can achieve identification accuracy of more than 90%. To the best of our knowledge, the proposed scheme is the first to estimate the ratios of two mixed protocols in DNS tunnels.

Low Frequency Current Ripple Mitigation of Two Stage Three-Phase PEMFC Generation Systems

Huiwen Deng,Qi Li,Zhixiang Liu,Lun Li,Weirong Chen 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

This paper presents a two stage three-phase proton exchange membrane fuel cell (PEMFC) generation system. When the system is connected to a three-phase load, it is very sensitive to the characteristics and type of the load. Especially unbalanced three-phase loads, which result in a pulsating power that is twice the output frequency at the inverter output, and cause the dc-link to generate low frequency ripples. This penetrates to the fuel cell side through the front-end dc-dc converter, which makes the fuel cell work in an unsafe condition and degrades its lifespan. In this paper, the generation and propagation mechanism of low frequency ripple is analyzed and its impact on fuel cells is presented based on the PEMFC output characteristics model. Then a novel method to evaluate low frequency current ripple control capability is investigated. Moreover, a control scheme with bandpass filter inserted into the current feed-forward path, and ripple duty ratio compensation based on current mode control with notch filter is also proposed to achieve low frequency ripple suppression and dynamic characteristics improvement during load transients. Finally, different control methods are verified and compared by simulation and experimental results.

Optimized Multiple Description Lattice Vector Quantization Coding for 3D Depth Image

( Huiwen Zhang ),( Huihui Bai ),( Yao Zhao ),( Meiqin Liu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.3

Multiple Description (MD) coding is a promising alternative for the robust transmission of information over error-prone channels. Lattice vector quantization (LVQ) is a significant version of MD techniques to design an MD image coder. However, different from the traditional 2D texture image, the 3D depth image has its own special characteristics, which should be taken into account for efficient compression. In this paper, an optimized MDLVQ scheme is proposed in view of the characteristics of 3D depth image. First, due to the sparsity of depth image, the image blocks can be classified into edge blocks and smooth blocks, which are encoded by different modes. Furthermore, according to the boundary contents in edge blocks, the step size of LVQ can be regulated adaptively for each block. Experimental results validate the effectiveness of the proposed scheme, which show better rate distortion performance compared with the conventional MDLVQ.

Low Frequency Current Ripple Mitigation of Two Stage Three-Phase PEMFC Generation Systems

Deng, Huiwen,Li, Qi,Liu, Zhixiang,Li, Lun,Chen, Weirong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

This paper presents a two stage three-phase proton exchange membrane fuel cell (PEMFC) generation system. When the system is connected to a three-phase load, it is very sensitive to the characteristics and type of the load. Especially unbalanced three-phase loads, which result in a pulsating power that is twice the output frequency at the inverter output, and cause the dc-link to generate low frequency ripples. This penetrates to the fuel cell side through the front-end dc-dc converter, which makes the fuel cell work in an unsafe condition and degrades its lifespan. In this paper, the generation and propagation mechanism of low frequency ripple is analyzed and its impact on fuel cells is presented based on the PEMFC output characteristics model. Then a novel method to evaluate low frequency current ripple control capability is investigated. Moreover, a control scheme with bandpass filter inserted into the current feed-forward path, and ripple duty ratio compensation based on current mode control with notch filter is also proposed to achieve low frequency ripple suppression and dynamic characteristics improvement during load transients. Finally, different control methods are verified and compared by simulation and experimental results.

Effective of high salt diet (HSD) on letrozole-induced polycystic ovarian syndrome (PCOS) mice

Suying Liang,Xiaoying Tang,Minmin Chen,Huiwen Liu,Wanying Li,Zixian Wang,Qi Qi Pang,Jia-Le Song 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

To investigate the effect of high salt diet (HSD, 8% NaCl) on the letrozole induced PCOS mice. At the total of experimental periods (35 days), all female C57BL/6J mice were randomly divided into normal groups, PCOS group (ingested letrozole daily for 21 days) and HSD+PCOS group. The body weight (BW) and histologic changes were evaluated. The serum levels of testosterone (T), LH, E2, FSH, INS, TG, TC, LDL, HDL were determined by ELISA kits. Compared with normal groups, the BW, T, LH, INS, TG, TC LDL-C in PCOS rats were significantly increased, and the levels of E2, FSH and HDL-C were significantly decreased. In addition, compared with the PCOS group, the BW, T, LH, INS, TG, TC LDL-C in HSD+PCOS rats were significantly increased, and the levels of E2, FSH and HDL-C were significantly decreased. Our results showed that HSD exacerbates metabolic disorders and hormonal imbalances in PCOS mice.

Dynamic stress of impeller blade of shaft extension tubular pump device based on bidirectional fluid-structure interaction

Kan Kan,Yuan Zheng,Shifeng Fu,Huiwen Liu,Chunxia Yang,Xin Zhang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.4

Current research on the stability of tubular pumps is mainly concerned with the transient hydrodynamic characteristics. However, the structural response under the influence of fluid-structure interaction hasn’t been taken fully into consideration. The instability of the structure can cause vibration and cracks, which may threaten the safety of the unit. We used bidirectional fluid-structure interaction to comprehensively analyze the dynamic stress characteristics of the impeller blades of the shaft extension tubular pump device. Furthermore, dynamic stress of impeller blade of shaft extension tubular pump device was solved under different lift conditions of 0° blade angle. Based on Reynolds-average N-S equation and SST k-ω turbulence model, numerical simulation was carried out for three-dimensional unsteady incompressible turbulent flow field of the pump device whole flow passage. Meanwhile, the finite element method was used to calculate dynamic characteristics of the blade structure. The blade dynamic stress distribution was obtained on the basis of fourth strength theory. The research results indicate that the maximum blade dynamic stress appears at the joint between root of inlet side of the blade suction surface and the axis. Considering the influence of gravity, the fluctuation of the blade dynamic stress increases initially and decreases afterwards within a rotation period. In the meantime, the dynamic stress in the middle part of inlet edge presents larger relative fluctuation amplitude. Finally, a prediction method for dynamic stress distribution of tubular pump considering fluid-structure interaction and gravity effect was proposed. This method can be used in the design stage of tubular pump to predict dynamic stress distribution of the structure under different operating conditions, improve the reliability of pump impeller and analyze the impeller fatigue life.

Stable colonization of Akkermansia muciniphila educates host intestinal microecology and immunity to battle against inflammatory intestinal diseases

Wang Bin,Chen Xuheng,Chen Zhiyuan,Xiao Huiwen,Dong Jiali,Li Yuan,Zeng Xiaozhou,Liu Jinjian,Wan Guoyun,Fan Saijun,Cui Ming 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Gut microbial preparations are widely used in treating intestinal diseases but show mixed success. In this study, we found that the therapeutic efficacy of A. muciniphila for dextran sodium sulfate (DSS)-induced colitis as well as intestinal radiation toxicity was ~50%, and mice experiencing a positive prognosis harbored a high frequency of A. muciniphila in the gastrointestinal (GI) tract. Stable GI colonization of A. muciniphila elicited more profound shifts in the gut microbial community structure of hosts. Coexisting with A. muciniphila facilitated proliferation and reprogrammed the gene expression profile of Lactobacillus murinus, a classic probiotic that overtly responded to A. muciniphila addition in a time-dependent manner. Then, a magnetic-drove, mannose-loaded nanophase material was designed and linked to the surface of A. muciniphila. The modified A. muciniphila exhibited enhancements in inflammation targeting and intestinal colonization under an external magnetic field, elevating the positive-response rate and therapeutic efficacy against intestinal diseases. However, the unlinked cocktail containing A. muciniphila and the delivery system only induced negligible improvement of therapeutic efficacy. Importantly, heat-inactivated A. muciniphila lost therapeutic effects on DSS-induced colitis and was even retained in the GI tract for a long time. Further investigations revealed that the modified A. muciniphila was able to drive M2 macrophage polarization by upregulating the protein level of IL-4 at inflammatory loci. Together, our findings demonstrate that stable colonization of live A. muciniphila at lesion sites is essential for its anti-inflammatory function.

Optimal SVM learning method based on adaptive sparse sampling and granularity shift factor

Hui Wen,Dongshun Jia,Zhiqiang Liu,Hang Xu,Guangtao Hao 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.4

To improve the training efficiency and generalization performance of a support vector machine (SVM) in a large-scale set, an optimal SVM learning method based on adaptive sparse sampling and the granularity shift factor is presented. The proposed method combines sampling optimization with learner optimization. First, an adaptive sparse sampling method based on the potential function density clustering is designed to adaptively obtain sparse sampling samples, which can achieve a reduction in the training sample set and effectively approximate the spatial structure distribution of the original sample set. A granularity shift factor method is then constructed to optimize the SVM decision hyperplane, which fully considers the neighborhood information of each granularity region in the sparse sampling set. Experiments on an artificial dataset and three benchmark datasets show that the proposed method can achieve a relatively higher training efficiency, as well as ensure a good generalization performance of the learner. Finally, the effectiveness of the proposed method is verified.