The GntR-Type Regulators GtrA and GtrB Affect Cell Growth and Nodulation of Sinorhizobium meliloti

Yi Wang,Ai-Min Chen,Ai-Yuan Yu,Li Luo,Guan-Qiao Yu,Jia-Bi Zhu,Yan-Zhang Wang 한국미생물학회 2008 The journal of microbiology Vol.46 No.2

GntR-type transcriptional regulators are involved in the regulation of various biological processes in bacteria, but little is known about their functions in Sinorhizobium meliloti. Here, we identified two GntR-type transcriptional regulator genes, gtrA and gtrB, from S. meliloti strain 1021. Both the gtrA1 mutant and the gtrB1 mutant had lower growth rates and maximal cell yields on rich and minimal media, as well as lower cell motility on swimming plates, than did the wild-type strain. Both mutants were also symbiotically deficient. Alfalfa plants inoculated with wild-type strain 1021 formed pink elongated nodules on primary roots. In contrast, the plants inoculated with the gtrA1 and gtrB1 mutants formed relatively smaller, round, light pink nodules mainly on lateral roots. During the first 3~4 weeks post-inoculation, the plants inoculated with the gtrA1 and gtrB1 mutants were apparently stunted, with lower levels of nitrogenase activity, but there was a remarkable increase in the number of nodules compared to those inoculated with the wild-type strain. Moreover, the gtrA1 and gtrB1 mutants not only showed delayed nodulation, but also showed markedly reduced nodulation competition. These results demonstrated that both GtrA and GtrB affect cell growth and effective symbiosis of S. meliloti. Our work provides new insight into the functions of GntR-like transcriptional regulators.

Sentinel lymph Node mapping versus systematic pelvic lymphadenectomy on the prognosis for patients with intermediate-high-risk Endometrial Cancer confined to the uterus before surgery: trial protocol for a non-inferiority randomized controlled trial (SNE

Jun Guan,Yu Xue,Rong-yu Zang,Ji-hong Liu,Jian-qing Zhu,Ying Zheng,Bo Wang,Hua-ying Wang,Xiao-jun Chen 대한부인종양학회 2021 Journal of Gynecologic Oncology Vol.32 No.4

Background: Sentinel lymph node (SLN) mapping has been recommended as an alternative staging approach to lymphadenectomy for apparent uterine-confined endometrial cancer (EC). However, the prognostic value of SLN mapping alone instead of systematic lymphadenectomy on EC patients remains unclear. Methods: A multi-center, open label, non-inferiority randomized controlled trial has been designed to identify if SLN mapping alone is not inferior to pelvic lymphadenectomy on prognosis of patients with intermediate-high-risk EC clinically confined to uterus. Eligible patients will be 1:1 randomly assigned to accept SLN mapping or pelvic lymphadenectomy. The primary endpoint is the 2-year progression-free survival (PFS). The second points are the 5-year PFS, 5-year overall survival, surgery-related adverse events and life quality. A total of 780 patients will be enrolled from 6 hospitals in China within 3-year period and followed up for 5 years. Trial Registration: ClinicalTrials.gov Identifier: NCT04276532

Chemical Composition and Active Antioxidants of Eucommia ulmoides Oliv. Bark

Guan-Zheng Qu,Chuan-Ling Si,Yu Yin,Myeong-Hyeon Wang 한국영양학회 2006 Nutritional Sciences Vol.9 No.4

??Chemical composition of the Eucommia ulmoides bark, including extractives, proximate, mineral, fatty acid and monosaccharide compositions, was studied The most abundant mineral was calcium (533.17 ㎎/100 g). α-linolenic acid (24.7%) and linoleic acid (24.3%), showed higher contents among the fatty acids. Major monosaccharides of E. ulmoides bark were arabinose (13.94 ㎎/g), xylose (18.91 ㎎/g) and glucose (119.7 ㎎/g). From the bark of E. ulmoides, four compounds were isolated and their structures were elucidated as caffeic acid (Ⅰ), kaempferol (Ⅱ), quercetin (Ⅲ) and isoquercitrin (Ⅳ) by spectroscopic analysis such as NMR and MS, including cellulose TLC and other chemical evidence such as hydrolyzation and acetylation. The antioxidant activities of four isolated compounds were evaluated by DPPH free radical scavenging, hydroxyl scavenging and reducing power assays. The results indicated that all the isolated compounds showed higher DPPH radical scavenging activity than α-tocopherol and BHT that were used as positive controls and these four compounds exhibited considerable reducing power and hydroxyl radical (OH') scavenging activity. Considering from the results above, it suggests that the E. ulmoides bark is a potential natural source of antioxidant material.

DC-Link Voltage Balance Control in Three-phase Four-wire Active Power Filters

Yu Wang,Yuanpeng Guan,Yunxiang Xie,Xiang Liu 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

The three-phase four-wire shunt active power filter (APF) is an effective method to solve the harmonic problem in three-phase four-wire power systems. In addition, it has two possible topologies, a four-leg inverter and a three-leg inverter with a split-capacitor. There are some studies investigating DC-link voltage control in three-phase four-wire APFs. However, when compared to the four-leg inverter topology, maintaining the balance between the DC-link upper and lower capacitor voltages becomes a unique problem in the three-leg inverter with a split-capacitor topology, and previous studies seldom pay attention to this fact. In this paper, the influence of the balance between the two DC-link voltages on the compensation performance, and the influence of the voltage balance controller on the compensation performance, are analyzed. To achieve the balance between the two DC-link capacitor voltages, and to avoid the adverse effect the voltage balance controller has on the APF compensation performance, a new DC-link voltage balance control strategy for the three-phase four-wire split-capacitor APF is proposed. Representative simulation and experimental results are presented to verify the analysis and the proposed DC-link voltage balance control strategy.

Application of Multilocus Sequence Analysis (MLSA) for Accurate Identification of Legionella spp. Isolated from Municipal Fountains in Chengdu, China, Based on 16S rRNA, mip, and rpoB Genes

Wang Guan,Ying Xu,Da-li Chen,Jia-nan Xu,Yu Tian,Jian-ping Chen 한국미생물학회 2012 The journal of microbiology Vol.50 No.1

Legionellosis (Legionnaires’ disease; LD) is a form of severe pneumonia caused by species of Legionella bacteria. Because inhalation of Legionella-contaminated aerosol is considered the major infection route, routine assessments of potential infection sources such as hot water systems, air-conditioner cooling water, and municipal fountains are of great importance. In this study, we utilized in vitro culture and multilocus sequence analysis (MLSA) targeting 16S rRNA, mip, rpoB, and mip-rpoB concatenation to isolate and identify Legionella spp. from 5 municipal fountains in Chengdu City, Sichuan Province, China. Our results demonstrated that 16S rRNA was useful for initial identification, as it could recognize isolates robustly at the genus level, while the genes mip, rpoB, and mip-rpoB concatenation could confidently discriminate Legionella species. Notably, the three subspecies of L. pneumophila could be distinguished by the analysis based on rpoB. The serotyping result of strain CD-1 was consistent with genetic analysis based on the concatenation of mip and rpoB. Despite regular maintenance and sanitizing methods, 4 of the 5 municipal fountains investigated in this study were positive for Legionella contamination. Thus, regularly scheduled monitoring of municipal fountains is urgently needed as well as vigilant disinfection. Although the application of MLSA for inspection of potential sites of infection in public areas is not standard procedure, further investigations may prove its usefulness.

Effects of Starvation on Lipid Metabolism and Gluconeogenesis in Yak

Yu, Xiaoqiang,Peng, Quanhui,Luo, Xiaolin,An, Tianwu,Guan, Jiuqiang,Wang, Zhisheng Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.11

This research was conducted to investigate the physiological consequences of undernourished yak. Twelve Maiwa yak ($110.3{\pm}5.85kg$) were randomly divided into two groups (baseline and starvation group). The yak of baseline group were slaughtered at day 0, while the other group of yak were kept in shed without feed but allowed free access to water, salt and free movement for 9 days. Blood samples of the starvation group were collected on day 0, 1, 2, 3, 5, 7, 9 and the starved yak were slaughtered after the final blood sample collection. The liver and muscle glycogen of the starvation group decreased (p<0.01), and the lipid content also decreased while the content of moisture and ash increased (p<0.05) both in Longissimus dorsi and liver compared with the baseline group. The plasma insulin and glucose of the starved yak decreased at first and then kept stable but at a relatively lower level during the following days (p<0.01). On the contrary, the non-esterified fatty acids was increased (p<0.01). Beyond our expectation, the ketone bodies of ${\beta}$-hydroxybutyric acid and acetoacetic acid decreased with prolonged starvation (p<0.01). Furthermore, the mRNA expression of lipogenetic enzyme fatty acid synthase and lipoprotein lipase in subcutaneous adipose tissue of starved yak were down-regulated (p<0.01), whereas the mRNA expression of lipolytic enzyme carnitine palmitoyltransferase-1 and hormone sensitive lipase were up-regulated (p<0.01) after 9 days of starvation. The phosphoenolpyruvate carboxykinase and pyruvate carboxylase, responsible for hepatic gluconeogenesis were up-regulated (p<0.01). It was concluded that yak derive energy by gluconeogenesis promotion and fat storage mobilization during starvation but without ketone body accumulation in the plasma.

Characteristics analysis of rotor-rolling bearing coupled system with fit looseness fault and its verification

Wang Haifei,Guan Xiaoying,Chen Guo,Gong Junjie,Yu Liang,Yuan Shijie,Zhu Zhida 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

Outer ring of bearing fit looseness fault is a common fault. Scratch often appears in the inner surface of pedestal. The fit looseness fault mechanism is not clear. For rotor-rolling bearing system with fit looseness fault between rotor-bearing outer ring and pedestal, a rotor coupling dynamic model that the interaction of bearing outer ring and pedestal are considered. This model is different from the universal rubbing model, where the directions of relative motion between rotor and stator are not considered. Numerical integration method is used to obtain the response of the system where the rotor is established by FEM and the bearing outer ring and pedestal are established by lumped mass model. Firstly, modal test results and simulation results were used to verify the correctness of this model. Secondly, the role of tightening torque between bearing outer ring and pedestal is considered, and the response characteristics of bearing and rotor are analyzed when fit looseness fault is considered. Finally, comparing the simulation results with test results, the waveform and spectrum are similar, which verifies the correctness of the fit looseness model. The fit looseness fault characteristics are that the acceleration after noise reduction shows periodic impact, up and down asymmetry, multiple frequencies appear. A method by increasing tightening torque is put forward to control the vibration caused by fit looseness fault.

DC-Link Voltage Balance Control in Three-phase Four-wire Active Power Filters

Wang, Yu,Guan, Yuanpeng,Xie, Yunxiang,Liu, Xiang The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

The three-phase four-wire shunt active power filter (APF) is an effective method to solve the harmonic problem in three-phase four-wire power systems. In addition, it has two possible topologies, a four-leg inverter and a three-leg inverter with a split-capacitor. There are some studies investigating DC-link voltage control in three-phase four-wire APFs. However, when compared to the four-leg inverter topology, maintaining the balance between the DC-link upper and lower capacitor voltages becomes a unique problem in the three-leg inverter with a split-capacitor topology, and previous studies seldom pay attention to this fact. In this paper, the influence of the balance between the two DC-link voltages on the compensation performance, and the influence of the voltage balance controller on the compensation performance, are analyzed. To achieve the balance between the two DC-link capacitor voltages, and to avoid the adverse effect the voltage balance controller has on the APF compensation performance, a new DC-link voltage balance control strategy for the three-phase four-wire split-capacitor APF is proposed. Representative simulation and experimental results are presented to verify the analysis and the proposed DC-link voltage balance control strategy.

Promoting N2 electroreduction to ammonia by fluorine-terminating Ti3C2Tx MXene

Ding Yu,Zhang Junbo,Guan Anxiang,Wang Qihao,Li Si,Al-Enizi Abdullah M.,Qian Linping,Zhang Lijuan,Zheng Gengfeng 나노기술연구협의회 2021 Nano Convergence Vol.8 No.14

Two-dimensional MXene-based materials are potential of presenting unique catalytic performances of electrocatalytic reactions. The surface functionalization of MXene-based catalysts is attractive for developing efficient electrocatalysts toward nitrogen reduction reaction. Herein, we reported a Ti 3 C 2 T x MXene with a medium density of surface functionalized fluorine terminal groups, as an excellent N 2 reduction reaction electrocatalyst with enhanced adsorption and activation of N 2 . The Ti 3 C 2 T x MXene catalyst showed a production rate of ammonia as 2.81 × 10 –5 μmol·s −1 ·cm −2 , corresponding to a partial current density of 18.3 μA·cm −2 and a Faradic efficiency of 7.4% at − 0.7 V versus reversible hydrogen electrode in aqueous solutions at ambient conditions, substantially exceeding similar Ti 3 C 2 T x MXene catalysts but with higher or lower densities of surface fluorine terminal groups. Our work suggests the capability of developing surface functionalization toolkit for enhancing electrochemical catalytic activities of two-dimensional MXene-based materials.

Betaine Effects on Morphology, Proliferation, and p53-induced Apoptosis of HeLa Cervical Carcinoma Cells in Vitro

Guo, Yu,Xu, Li-Sha,Zhang, Ding,Liao, Ya-Ping,Wang, Hai-ping,Lan, Zhi-Hui,Guan, Wei-Jun,Liu, Chang-Qing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Objectives: To investigate the effects of betaine on HeLa cell growth and apoptosis and molecular mechanisms. Materials and Methods: Concentrations of 0.1, 1.0, 5.0, 20.0, 100.0 mg/ml of betaine were used to evaluate the anticancer efficacy for HeLa cells respectively, and MCF-10A was also detected as a normal diploid cell control. Results: We found that proliferation of HeLa cells was inhibited significantly upon exposure to increasing betaine levels with the MTT test (p<0.05). The percentage of S phase cells in the low dose groups (<5mg/ml) were distinctly higher than in high dose groups, and the rates of Sub-G1 phase were the opposite (p<0.01); A high concentration of betaine (>5.0mg/ml) significantly promoted the apoptosis of HeLa cells (p<0.01). SOD activities of the low dose groups were slightly higher than the control group (p<0.05) and there were obvious synchronicity and correlation among the expression of promoting apoptosis genes Bax, P53, Caspase 3 and apoptosis suppression gene Bcl-2. In response to an apoptosis-inducing stimulus, p53 and cyclin D1 could be activated with blockage of the cell cycle at G1/S or S/G2 checkpoints. Conclusions: Our data showed that betaine could promote HeLa cells proliferation in vitro at low concentrations. In contrast, high concentrations could significantly inhibit cell growth and migration, and induce apoptosis of HeLa cells through caspase 3 signaling and further promoted necrosis. This might imply that betaine exhibits tumoricidal effects and acts as a biological response modifier in cancer treatment by inducing apoptosis and cell cycle arrest in a dose and time-dependent manner.