Liquid Chromatography Quadrupole Time-Of-Flight Tandem Mass Spectrometry for Selective Determination of Usnic Acid and Application in Pharmacokinetic Study

Fang, Minfeng,Wang, Hui,Wu, Yang,Wang, Qilin,Zhao, Xinfeng,Zheng, Xiaohui,Wang, Shixiang,Zhao, Guifang Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column ($50{\times}2.1$ mm, $5{\mu}m$) with a mobile phase consisting of water (containing $5{\times}10^{-3}$ M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 ${\rightarrow}$ m/z 313.2017 for usnic acid and m/z 153.1024 ${\rightarrow}$ m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ${\pm}7.0%$. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.

Liquid Chromatography Quadrupole Time-Of-Flight Tandem Mass Spectrometry for Selective Determination of Usnic Acid and Application in Pharmacokinetic Study

Minfeng Fang,Hui Wang,Yang Wu,Qilin Wang,Xinfeng Zhao,Xiao-Hui Zheng,Shixiang Wang,Guifang Zhao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column (50 × 2.1 mm, 5 μm) with a mobile phase consisting of water (containing 5 × 10−3 M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 → m/z 313.2017 for usnic acid and m/z 153.1024 → m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ± 7.0%. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.

Efficacy and Safety of Radiofrequency Ablation Combined with Transcatheter Arterial Chemoembolization for Hepatocellular Carcinomas Compared with Radiofrequency Ablation Alone: A Time-to-Event Meta-Analysis

Xin Wang,Yanan Hu,Mudan Ren,Xinlan Lu,Guifang Lu,Shuixiang He 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.1

Objective: To compare the efficacy and safety of combined radiofrequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) with RFA alone for hepatocellular carcinomas (HCC). Materials and Methods: Randomized controlled trial (RCT) studies that compared the clinical or oncologic outcomes of combination therapy of TACE and RFA versus RFA for the treatment of HCC were identified through literature searches of electronic databases (Pubmed, Embase, Cochrane Library, China Biology Medicine disc, China National Knowledge Infrastructure, and Google Scholar). Hazard ratios (HRs) or odds ratios (ORs) with their corresponding 95% confidence interval (CI) were combined as the effective value to assess the summary effects. The strength of evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation system. Results: Six RCTs with 534 patients were eligible for inclusion in this meta-analysis. The meta-analysis showed that the combination of TACE and RFA is associated with a significantly longer overall survival (HR = 0.62, 95% CI: 0.49–0.78, p < 0.001) and recurrence-free survival (HR = 0.55, 95% CI: 0.40–0.76, p < 0.001) in contrast with RFA monotherapy. The seemingly higher incidence of major complications in the combination group compared with RFA group did not reach statistical significance (OR = 1.17, 95% CI: 0.39–3.55, p = 0.78). Conclusion: In patients with HCC, the combination of TACE and RFA is associated with significantly higher overall survival and recurrence-free survival, as compared with RFA monotherapy, without significant difference in major complications.

Effect of lactoferrin on ram sperm motility after cryopreservation

Su Jie,Wang Caiyun,Song Yongli,Yang Yanyan,Cao Guifang 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.9

Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze–thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro. Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 μg/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS). Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 μg/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 μg/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 μg/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05). Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 μg/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm. Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze–thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro.Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 μg/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS).Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 μg/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 μg/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 μg/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05).Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 μg/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm.

Effect of La(NO3)3 and Ce(NO3)3 on shoot induction and seedling growth of in vitro cultured anoectochilus roxburghii

Yingya Xu,Guifang Zhang,Yan Wang,Ge Guo 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2

Anoectochilus roxburghii, a highly valuable medicinal plant species, is threatened in its native habitat. To ensure the sustainability of this useful resource, we studied the effect of La(NO3)3 and Ce(NO3)3 on plant tissue culturepropagated A. roxburghii. Apical buds, mid-stem segments, and basal rhizome segments were taken from aseptic seedlings of A. roxburghii and cultured in vitro on half-strength Murashige-Skoog medium containing different concentrations (up to 5.0 mg/L) of La(NO3)3 or Ce(NO3)3. After 100 d of culturing, average heights of plantlets derived from apical buds were 6.0 cm with 5.0 mg/L La(NO3)3 and 6.2 cm with 2.0 mg/L Ce(NO3)3, which respectively increased by 28.0% and 32.0% as compared with that in the non-treated control group. The optimum concentration for shoot induction from mid-stem segments was 1.0 mg/L Ce(NO3)3 which had a better proliferation times of 1.5-fold and an average length of 3.0 cm compared with 1.0-fold and 2.2 cm in the control group. Optimum growth from basal rhizome segments was achieved on media supplemented with 3.0 mg/L Ce(NO3)3, which provided a better proliferation times of 5.1-fold and an average shoot length of 4.5 cm compared with corresponding control values of 2.0-fold and 3.5 cm. Our results showed that La(NO3)3 and Ce(NO3)3 can accelerate A. roxburghii regeneration, which was probably due to the effect on chlorophyll contents, enzymes activity (superoxide dismutase, catalase and peroxidase) and malonldialedhyde contents caused by the addition of La(NO3)3 or Ce(NO3)3.

Isogeometric analysis of functionally graded CNT-reinforced composite plates based on refined plate theory

Zhenyu Liu,Chuang Wang,Guifang Duan,Jianrong Tan 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.9

A simple and effective approach based on refined plate theory (RPT) is proposed to study the static and free vibration characteristics of functionally graded CNTreinforced composite (FG-CNTRC) plates. Compared to traditional higher order shear deformation theories (HSDTs), the proposed method shows more efficient for FG-CNTRC plates analysis. To solve the C1-continuity requirement of the RPT, we used isogeometric analysis (IGA) to approximate the displacement field, which shows more advantages than the FEA, since it can construct higher-order elements without additional variables. This is an advantage for plate structural analysis because more variables make the calculation cumbersome. Finally, four types of FG-CNTRC plates were investigated and the results show the accuracy and efficiency of the proposed method.

큰방가지똥 추출물의 항당뇨 및 항고혈압효과

왕명현,허명록,Lan Wang,Guifang Xu 한국생약학회 2011 생약학회지 Vol.42 No.1

In this study, we evaluated the bioactivities of methanol extract and its solvent fractions of Sonchus asper (L.) Hill. The EtOAc fraction of S. asper exhibited more strong antioxidant activity than other extracts as evidenced by the strongest 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity with a EC_50 value at 33.55 µg/mL and reducing power, the total polyphenol (180.71 mg GAE/g) and flavonoid contents (145.86 mg QE/g) of S. asper extract were higher than other extracts. The EtOAc fraction of the S. asper also showed 47.38% mushroom tyrosinase inhibition activity, 56.22% α-glucosidase inhibition and 46.58% α-amylase inhibition ratio at 1 mg/mL. Both methylene chloride and EtOAc fractions of methanol extract of S. asper effectively reduced of the 86.34% and 62.03% angiotensin I converting enzyme (ACE) activity at 2 mg/mL, respectively. These findings suggest that the EtOAc fraction of the S. asper could be a potential antioxidant in food additive, medicinal,and industry product.

Airbag Damping of the Hollow Fiber Composite with Different Porosity in the Fiber Wall

Mingjun Li,Guoqun Zhou,Yongwen Xu,Guifang Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

The inner cavity of the hollow fiber with porosity in its fiber wall constitutes a damping airbag with slow passage of gas. The magnitude of the damping value of the airbag and its damping influencing factors need to be researched, which adds the nonlinear airbag damping to the damping of the raw materials and increases the total damping loss factor of the structure. In this paper, the hollow fiber damping materials with different hollow inside diameters, different fiber wall thicknesses, different wall porosity and different wall pore structure were prepared by adjusting and controlling the technological parameters of the hollow fiber spinning and the formula of spinning casting solution. Meanwhile, we have a comprehensive study on the relationship between the factors and performances. It was found and confirmed that the size of the airbag, the wall pore structure, the wall porosity and the wall thickness of the airbag were the most crucial parameters, which can affect the additional damping of the airbag in the hollow fiber. And the controlling method of the four key parameters was also obtained. Finally, the mechanism and effect of hollow fiber airbag damping was proved.

Solution processable small molecules for organic light-emitting diodes

Duan, Lian,Hou, Liudong,Lee, Tae-Woo,Qiao, Juan,Zhang, Deqiang,Dong, Guifang,Wang, Liduo,Qiu, Yong Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.31

<P>Organic light-emitting diodes (OLEDs) based on vacuum deposited small molecules have undergone significant progress since the first efficient double-layered OLEDs were reported in 1987 by Tang and Van Slyke. Recently, solution processed small molecular OLEDs are also drawing more and more research attention, as such a technology combines advantages of the facile synthesis of small molecules and the low-cost solution process like polymers. The performance of OLEDs made by solution process is gradually catching up with their vacuum deposited counterparts. This feature article will review the device structures adopted to achieve high performance solution processed OLEDs, the development of solution processable small molecules, and the comparisons of the different nature of the films and devices fabricated by solution-process or by vacuum deposition. Finally, the prospects and remaining problems will be discussed.</P> <P>Graphic Abstract</P><P>Recent developments, prospects and remaining problems of organic light-emitting diodes based on solution processable small molecules are reviewed, with comparisons of the films and devices by solution-process or vacuum deposition. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b926348a'> </P>

Correlation between in vitro fertilization and artificial insemination in Holstein bulls

Sun Wei,Li Yunxia,Su Jie,Bao Xiangnan,Ding Rui,Zhao Gaoping,Cao Guifang,Hu Shuxiang,Wang Jianguo,Sun Qingyuan,Yu Haiquan,Li Xihe 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.12

Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI).Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI.Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%.Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding. Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI). Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI. Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%. Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding.