Optimization of Ultrasonic-assisted Extraction of Flavonoid from Portulaca oleracea L. by Response Surface Methodology and Chemical Composition Analysis

Chenxi Wang,Yuping Li,Li-Hua Yao,Guangjie Wu,Jun Chang,Chengchuang Shu,Meiqin Chen 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.5

Optimization of ultrasonic extraction of Portulacaoleracea L. flavonoids (POF) was investigated using single-factorexperimentation combined with response surface methodology. The optimal conditions for the highest yield (16.25 mg RE/g DW)of POF was 39.01% ethanol, 55.25oC extraction temperature, 15min extraction time, and 23.92 (v/m) liquid-to-solid ratio. Thecrude extract of POF was purified on the polyamide resin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a yellowtetrazole assays of the flavonoids were evaluated, which suggestedthe concentrations of the flavonoids (0-1 mg/mL) and quercetin(0-1 mg/mL). Quercetin was identified in the extract by comparingrelative retention time of the reference standard.

Combination of berberine and ciprofloxacin reduces multi-resistant Salmonella strain biofilm formation by depressing mRNA expressions of luxS, rpoE, and ompR

Chenxi Shi,Minmin Li,Ishfaq Muhammad,Xin Ma,Yicong Chang,Rui Li,Changwen Li,Jingshan He,Fangping Liu 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.6

Bacterial biofilms have been demonstrated to be closely related to clinical infections and contribute to drug resistance. Berberine, which is the main component of Coptis chinensis, has been reported to have efficient antibacterial activity. This study aimed to investigate the potential effect of a combination of berberine with ciprofloxacin (CIP) to inhibit Salmonella biofilm formation and its effect on expressions of related genes (rpoE, luxS, and ompR). The fractional inhibitory concentration (FIC) index of the combination of berberine with CIP is 0.75 showing a synergistic antibacterial effect. The biofilm’s adhesion rate and growth curve showed that the multi-resistant Salmonella strain had the potential to form a biofilm relative to that of strain CVCC528, and the antibiofilm effects were in a dose-dependent manner. Biofilm microstructures were rarely observed at 1/2 × MIC/FIC concentrations (MIC, minimal inhibition concentration), and the combination had a stronger antibiofilm effect than each of the antimicrobial agents used alone at 1/4 × FIC concentration. LuxS, rpoE, and ompR mRNA expressions were significantly repressed (p < 0.01) at 1/2 × MIC/FIC concentrations, and the berberine and CIP combination repressed mRNA expressions more strongly at the 1/4 × FIC concentration. The results indicate that the combination of berberine and CIP has a synergistic effect and is effective in inhibiting Salmonella biofilm formation via repression of luxS, rpoE, and ompR mRNA expressions.

Oligo(ethylene glycol)-Functionalized Ratiometric Fluorescent Probe for the Detection of Hydrazine in Vitro and in Vivo

Li, Jun,Cui, Yuanchao,Bi, Chenxi,Feng, Shaoqiong,Yu, Fengzhen,Yuan, En,Xu, Shengzhen,Hu, Zhe,Sun, Qi,Wei, Dengguo,Yoon, Juyoung American Chemical Society 2019 ANALYTICAL CHEMISTRY - Vol.91 No.11

<P>Hydrazine induced toxicity causes serious harm to the health of humans. The detection of N<SUB>2</SUB>H<SUB>4</SUB> in vitro and in vivo has attracted a great deal of attention, especially in the context of fluorescent probes. Although some fluorescent N<SUB>2</SUB>H<SUB>4</SUB> probes have been reported, only a few operate in purely aqueous media and, as a result, require the use of organic cosolvents which hinders their use in analysis of real samples. In addition, most of the current N<SUB>2</SUB>H<SUB>4</SUB> probes are either “off-on” or “on-off” types, in which it is difficult to eliminate interference from background fluorescence commonly occurring in in vitro and in vivo systems. Furthermore, some probes are unable to differentiate hydrazine from other organic amines. To address the above problems, we developed a novel oligo(ethylene glycol)-functionalized fluorescent probe for the detection of N<SUB>2</SUB>H<SUB>4</SUB>. The probe, which has a donor−π-acceptor (D−π-A)-type structure, is water-soluble, and it can be utilized to selectively detect N<SUB>2</SUB>H<SUB>4</SUB> in both colorimetric and ratiometric mode. Furthermore, the probe is able to differentiate hydrazine from other organic amines and can be used to detect hydrazine vapor and for imaging A549 cells and zebrafish.</P> [FIG OMISSION]</BR>

Esophagogastric Junction Contractility Integral Reflect the Anti-reflux Barrier Dysfunction in Patients with Gastroesophageal Reflux Disease

( Chenxi Xie ),( Jinhui Wang ),( Yuwen Li ),( Niandi Tan ),( Yi Cui ),( Minhu Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.1

Background/Aims Anti-reflux barrier dysfunction is one of the primary mechanisms in gastroesophageal reflux disease (GERD) pathogenesis. The esophagogastric junction contractile integral (EGJ-CI) is a new metric adopted to evaluate the EGJ contractility, which implies the antireflux barrier function. The aim of the current study was to validate this new metric in patients with GERD and its correlation with the esophageal acid exposure, as well as the efficacy of proton pump inhibitor treatment. Methods Ninety-eight patients with GERD and 21 healthy controls were included in the study. Upper endoscopy, high-resolution manometry (HRM) and 24-hour multichannel intraluminal impedance-pH monitoring were performed in all patients. Three respiration cycles were chosen at the initial HRM resting frame and the value computed with distal contractile integral tool was then divided by the duration of the cycles to yield EGJ-CI. All the patients were treated with esomeprazole 20 mg twice-daily for 8 weeks. Results EGJ-CI was lower in the patients with GERD than that of the controls (P < 0.05). For patients with GERD, EGJ-CI was lower in those with hiatal hernia (P < 0.05). The new metric correlated with esophageal acid exposure in the supine position (P < 0.05), and it also negatively correlated to the total reflux episodes (P < 0.05). There was no significant difference on EGJ-CI between patients with and without response to the esomeprazole treatment (P = 0.627). Conclusions EGJ-CI reflected the dysfunction of the anti-reflux barrier in patients with GERD, but it had little impact on the esomeprazole response. (J Neurogastroenterol Motil 2017;23:27-33)

Esophageal Baseline Impedance Reflects Mucosal Integrity and Predicts Symptomatic Outcome With Proton Pump Inhibitor Treatment

( Chenxi Xie ),( Daniel Sifrim ),( Yuwen Li ),( Minhu Chen ),( Yinglian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.1

Background/Aims Esophageal baseline impedance, which is decreased in gastroesophageal reflux disease (GERD) patients, is related to the severity of acid reflux and the integrity of the esophageal mucosa. The study aims to compare the baseline impedance and the dilated intercellular spaces (DIS) within patients with typical reflux symptoms and to evaluate the correlation of baseline impedance with DIS, esophageal acid exposure, as well as the efficacy of proton pump inhibitor (PPI) treatment. Methods Ninety-two patients and 10 healthy controls were included in the study. Erosive esophagitis (EE) was defined by esophageal mucosal erosion under upper endoscopy. Patients without mucosa erosion were divided into groups with pathologic acid reflux (non-erosive reflux disease [NERD]) or with hypersensitive esophagus. The biopsies of esophageal mucosa were taken 2-4 cm above the gastroesophageal junction Z-line during upper endoscopy for DIS measurement. All the patients received esomeprazole 20 mg twice-daily treatment for 8 weeks. The efficacy of esomeprazole was evaluated among all patients. Results The intercellular spaces were dilated in both EE and NERD patients (P < 0.05). The value 0.73 mm could be used as the cut-off DIS value to distinguish patients from controls (area under the curve [AUC] = 0.849, P < 0.01). One thousand seven hundred sixty-four ohms could be used as the cut-off impedance values to distinguish patients from controls (AUC = 0.794, P < 0.01). The baseline impedance was decreased in both EE patients and NERD patients, and negatively correlated to the acid exposure time (r = -0.527, P < 0.05). There was a weak correlation between DIS and baseline impedance (r = -0.230, P < 0.05). “Baseline impedance > 1764 Ω” was an independent predictor for PPI failure (OR, 11.9; 95% CI, 2.4-58.9; P < 0.01). Conclusions The DIS and decreased baseline impedance was observed in patients with mucosa erosion or pathological acid reflux. The baseline impedance reflected the mucosal integrity, it was more sensitive to esophageal acid exposure. Patients with high impedance might not benefit from the PPI treatment. (J Neurogastroenterol Motil 2018;24:43-50)

Optimization of Ultrasonic-assisted Extraction of Flavonoid from Portulaca oleracea L. by Response Surface Methodology and Chemical Composition Analysis

Wang, Chenxi,Li, Yuping,Yao, Lihua,Wu, Guangjie,Chang, Jun,Shu, Chengchuang,Chen, Meiqin 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.5

Optimization of ultrasonic extraction of Portulaca oleracea L. flavonoids (POF) was investigated using single-factor experimentation combined with response surface methodology. The optimal conditions for the highest yield (16.25 mg RE/g DW) of POF was 39.01% ethanol, $55.25^{\circ}C$ extraction temperature, 15 min extraction time, and 23.92 (v/m) liquid-to-solid ratio. The crude extract of POF was purified on the polyamide resin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a yellow tetrazole assays of the flavonoids were evaluated, which suggested the concentrations of the flavonoids (0-1 mg/mL) and quercetin (0-1 mg/mL). Quercetin was identified in the extract by comparing relative retention time of the reference standard.

Relationship Between Salivary Pepsin Concentration and Esophageal Mucosal Integrity in Patients With Gastroesophageal Reflux Disease

( Yu-wen Li ),( Daniel Sifrim ),( Chenxi Xie ),( Minhu Chen ),( Ying-lian Xiao ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.4

Background/Aims Increased salivary pepsin could indicate an increase in gastro-esophageal reflux, however, previous studies failed to demonstrate a correlation between salivary pepsin concentrations and 24-hour esophageal acid exposure. This study aims to detect the salivary pepsin and to evaluate the relationship between salivary pepsin concentrations and intercellular spaces (IS) in different gastroesophageal reflux disease phenotypes in patients. Methods A total of 45 patients and 11 healthy volunteers were included in this study. All subjects underwent upper gastrointestinal endoscopy, 24-hour ambulatory multichannel impedance-pH (MII-pH) monitoring, and salivary sampling at 3-time points during the 24-hour MII-pH monitoring. IS were measured by transmission electron microscopy, and salivary pepsin concentrations were determined by enzyme-linked immunosorbent assay. Results The IS measurements were greater in the esophagitis (EE), non-erosive reflux disease (NERD), and hypersensitive esophagus (HO) groups than in the functional heartburn (FH) and healthy volunteer groups, and significant differences were indicated. Patients with NERD and HO had higher average pepsin concentrations compared with FH patients. A weak correlation was determined between IS and salivary pepsin among patients with NERD (r = 0.669, P = 0.035). Conclusions We confirmed the presence of a higher level of salivary pepsin in patients with NERD than in patients with FH. Salivary pepsin concentrations correlated with severity of mucosal integrity impairment in the NERD group. We suggest that in patients with NERD, low levels of salivary pepsin can help identify patients with FH, in addition the higher the pepsin concentration, the more likely the severity of dilated IS. (J Neurogastroenterol Motil 2017;23:517-525)

The relationship between bacterial diversity and organic carbon mineralization in soft rock and sand compound soil

Guo Zhen,Li Juan,Ge Lei,Yang Chenxi,Han Jichang 한국미생물학회 2020 The journal of microbiology Vol.58 No.9

The soil organic carbon (SOC) mineralization rate in sandy soil plays an important role in improving soil quality, and a research is needed to determine management practices that optimize the mineralization rate. When sandy soil is improved by adding soft rock, the specific promotion process of bacterium to SOC mineralization remain unclear. To investigate these mechanisms, we selected four treatments with soft rock to sand volume ratios of 0:1 (CK), 1:5 (C1), 1:2 (C2) and 1:1 (C3) to study. The mineralization rate of organic carbon was measured using the lye absorption method. Highthroughput sequencing and scanning electron microscopy were used to determine the bacterial community structure and soil microstructure, respectively. The results showed that the organic carbon content of the sandy soil increased significantly (182.22–276.43%) after using the soft rock treatments. The SOC mineralization rate could be divided into two stages: a rapid decline during days 1–8 and a slow decline during days 8–60. With increased incubation time, the intensity of the cumulative release of organic carbon gradually weakened. Compared with the CK treatment, the SOC mineralization accumulation (Ct) and the potential mineralizable organic carbon content (C0) in the C1, C2, and C3 treatments increased significantly, by 106.98–225.94% and 112.22– 254.08%, respectively. The cumulative mineralization rate (Cr) was 18.11% and 21.38% smaller with treatments C2 and C3, respectively. The SOC mineralization rate constant (k) decreased significantly after the addition of soft rock, while the half-turnover period (Th) changed inversely with k. Compared with the CK treatment, the number of gene copies of the soil bacteria increased by 15.38–272.53% after adding soft rock, with the most significant increase in treatment C3. The bacterial diversity index also increased significantly under treatment C3. The three dominant bacteria were Proteobacteria, Actinobacteria, and Chloroflexi. The correlation between Cr and one of the non-dominant bacteria, Firmicutes, was large, and the bacteria had a significant positive correlation with k. At the same time, the abundance of Firmicutes under treatments C2 and C3 was small. As the proportion of soft rock increased, the soil particles changed from point contact to surface contact, and the adhesion on the surface of the particles gradually increased. Results from this study show that the retention time of SOC can be increased and the carbon sequestration effect is better when the ratio of soft rock to sand is set to 1:2.

Development of a Novel 30 kV Solid-state Switch for Damped Oscillating Voltage Testing System

Hou, Zhe,Li, Hongjie,Li, Jing,Ji, Shengchang,Huang, Chenxi The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper describes the design and development of a novel semiconductor-based solid-state switch for damped oscillating voltage test system. The proposed switch is configured as two identical series-connected switch stacks, each of which comprising 10 series-connected IGBT function units. Each unit consists of one IGBT, a gate driver, and an auxiliary voltage sharing circuit. A single switch stack can block 20 kV-rated high voltage, and two stacks in series are proven applicable to 30 kV-rated high voltage. The turn-on speed of the switch is approximately 250 ns. A flyback topology-based power supply system with a front-end power factor correction is built for the drive circuit by loosely inductively coupling each unit with a ferrite core to the primary side of a power generator to obtain the advantages of galvanic isolation and compact size. After the simulation, measurement, and estimation of the parasitic effect on the gate driver, a prototype is assembled and tested under different operating regimes. Experimental results are presented to demonstrate the performance of the developed prototype.

Clinical Application of Ultrasound-Guided Thyroid Fine Needle Aspiration Biopsy and Thinprep Cytology Test in Diagnosis of Thyroid Disease

Wei, Ying,Lu, Yao,Li, Chenxi Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.10

Purpose: To study the clinical application value of ultrasound guided thyroid fine needle aspiration biopsy and thinprep cytology testing in diagnosis of thyroid disease. Methods: A total of 78 patients with thyroid nodules were enrolled, 34 males and 44 females, aged 33-64 years old with mean age of 47.6 years. All underwent thyroid module fine needle puncture after surgery to assess cell pathology and histopathological features. Results: Sufficient specimens were obtained from all of 78 patients, the cytological results of 73 cases (93.6 %) being consistent with pathological results. While 20 cases (25.6 %) were malignant tumors, 44 (56.4 %) were benign and 9 (11.5 %) were non-tumor lesions. The sensitivity of benign and malignant thyroid nodule by thyroid fine needle puncture was 90.9 %, specificity was 98.1 % and the positive predictive value was 96.3 %. Conclusions: It is demonstrated that ultrasound-guided thyroid fine needle aspiration biopsy and thinprep cytology testing have diagnostic value in clinical application for thyroid disease,showing good diagnostic coincidence rates with histopathological examination. They can thus be regarded as safe and effective for preoperative diagnosis and providing an appropriate basis for selection of surgery.