Total intravenous anesthesia for liver resections: anesthetic implications and safety

Tan Selene Yan Ling,Hwang Nian Chih 대한마취통증의학회 2022 Korean Journal of Anesthesiology Vol.75 No.5

Inhalational anesthetics have been the default agents for general anesthesia maintenance for several decades. However, with advances in total intravenous anesthesia (TIVA) and a growing body of evidence on the potential benefits of TIVA, anesthesiologists need to question this paradigm. Some of the benefits of propofol-based TIVA, such as its antiemetic properties and patients’ smooth emergence, are widely acknowledged. A growing body of evidence suggests that TIVA may potentially benefit the immune system and cancer outcomes. From an existential health perspective, there is evidence that inhalational agents have a materially higher global warming potential than propofol-based TIVA. Despite the compelling potential benefits of propofol-based TIVA, there are barriers to its widespread adoption. To examine the applicability of TIVA as a mainstay agent more rigorously, we discuss the safety and applicability of propofol-based TIVA in the context of complex major abdominal surgery, specifically, liver resection surgery. We also discuss the use of propofol-based TIVA in liver resection surgery with a broad, integrated approach, addressing general and specific clinical considerations, economic factors, and operating room turnover.

Efficacy of perineural versus intravenous dexamethasone in prolonging the duration of analgesia when administered with peripheral nerve blocks: a systematic review and meta-analysis

Tan Elizabeth Sein Jieh,Tan Yan Ru,Liu Christopher Wei Yang 대한마취통증의학회 2022 Korean Journal of Anesthesiology Vol.75 No.3

Background: Perineural dexamethasone has been regarded as a promising adjunct for prolonging the duration of nerve blocks. However, it is uncertain whether its effects are due to local effects on the nerves or from systemic absorption. This systematic review aimed to compare the duration of postoperative analgesia associated with perineural versus intravenous dexamethasone as an adjunct to peripheral nerve blocks. Methods: A total of 2,216 relevant academic articles were identified after a comprehensive search of PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from 1967 until 2020. All randomized controlled trials that compared perineural and intravenous dexamethasone as adjuncts to peripheral nerve limb blocks were included.Results: Fifteen randomized controlled trials (1,467 cases; 738 perineural dexamethasone, 729 intravenous dexamethasone) were eligible. The primary outcome (duration of analgesia) was significantly longer in the perineural than in the intravenous dexamethasone group (mean difference [MD]: 2.72 h, 95% CI [1.42, 4.01], P < 0.001). Perineural dexamethasone was also found to prolong the sensory block (MD: 3.45 h, 95% CI [1.36, 5.54], P = 0.001) and lower 24 h postoperative pain scores (MD: −0.74 h, 95% CI [−1.40, −0.07], P = 0.03).Conclusions: This review confirms the greater efficacy of perineural compared to intravenous dexamethasone in prolonging the analgesic duration of peripheral nerve blocks. However, the extent of prolongation was small and may not represent a clinically meaningful difference.

The Roles of the Exchange Rate and Labor Skill Composition on Vietnam’s Trade Balance Vis-à-Vis Main Trading Partners

Yan Tan,UTAI UPRASEN 국제지역학회 2018 국제지역연구 Vol.22 No.3

This paper investigates the effects of exchange rate and labor skill composition on Vietnam's trade balance with her twenty main trading partners. Using balanced panel data from 2000 to 2016, the authors analyze Vietnam's total trade balance and the trade balance which is disaggregated based on labor skill sophistication. Three main findings are presented. Firstly, exchange rate has a positive effect on Vietnam's trade balance, but the small value of estimated coefficient indicates that its effect is limited. Secondly, Vietnam's trade balance of the high labor-skill produced and medium-skill white collar labor-produced goods is worsened when VND (Vietnamese Dong) depreciates. Thirdly, moving up the labor skill ladder and promoting the none-price competitiveness of the high labor-skill produced and medium-skilled white collar labor-produced goods can improve Vietnam's total trade balance, while promoting the low-skill labor-produced and medium-skill blue collar-labor produced goods can no longer contribute to Vietnam's total trade balance.

Asymmetry of Cloud Vertical Structures and Associated Radiative Effects in Typhoon over the Northwest Pacific Based on CloudSat Tropical Cyclone Dataset

Yan Yafei,Tan Jianguo,Cui Linli,Yu Wei,Hu Yan 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.4

The clouds’ macro-, microphysical vertical structures and radiative effects in 4 shear-relative quadrants of typhoon over the northwest Pacific during development, maturity and extinction stages are studied based on CloudSat Tropical Cyclone dataset and China Meteorological Administration tropical cyclone dataset from 2nd June 2006 to 31th December 2015. The typhoon cloud is in an asymmetric “mushroom” shape, with the downshear quadrants (in particular of the downshear left quadrant (DL)) have denser clouds than the upshear quadrants. Cloud ice water content mainly distributes near typhoon center with wide vertical range (6–17 km). A large number of ice particles with small sizes are gathering in high levels, while small amount of ice particles with large sizes are gathering in low levels. As typhoon matures, the number concentration and size of cloud ice particles in inner ring increases, especially in the DL quadrant; while in the upshear left (UL) quadrant, a larger amount of ice particles with bigger sizes are transport to high levels (above 16 km) by deeper convection near storm center. The shortwave (longwave) cloud radiative effects (CRE) is mainly heating (cooling) upper layer atmosphere between 10 km and 17 km (between 14 km and 17 km), and the net CRE on atmosphere is heating almost at any levels in typhoon. The strongest heating of shortwave CRE and net CRE, as well as the strongest cooling of longwave CRE are in the DL quadrant at development stage and in the UL quadrant at maturity stage in inner core of storms. The existences of typhoon clouds mainly decrease solar radiation penetrating to the earth surface and increase longwave radiation absorbed by the whole atmosphere in typhoon’s inner core, and they are generally stronger in downshear (especially in DL) quadrants, except the maturity stage when the UL quadrant performs the strongest shortwave CRE on the surface and longwave CRE on the atmosphere in typhoon’s inner core.

Increasing Demeclocycline Production in Streptomyces aureofaciens by Manipulating the Expression of a Novel SARP Family Regulator and Its Genes

Yan-Ying Tan,Guang-Yao Zhu,Rui-Fang Ye,Hong-Zhou Zhang,De-Yu Zhu 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.6

Demeclocycline (DMCTC), a tetracycline derivative antibiotic produced by Streptomyces aureofaciens, has attracted attention owing to its high bioavailability, prolonged maintenance of a therapeutic concentration, and greater efficacy against many infectious microorganisms. However, the productivity of the DMCTC-producing strains has remained low. Thus, it is necessary to identify gene-knockout or amplification targets to increase DMCTC production. Here, we demonstrated that ctcB, which encodes a Streptomyces antibiotic regulatory protein (SARP), and ctcC, which encodes a resistance gene, positively regulate the biosynthesis of DMCTC in S. aureofaciens strain DT1. In particular, overexpression of the ctcB gene in S. aureofaciens DT1 significantly enhanced DMCTC production, resulting in increased expression of ctcG, ctcN, ctcQ, ctcH, ctcV, and ctcC. The deletion of ctcB dramatically reduced the DMCTC level, implying that CtcB is an activator of DMCTC biosynthesis. Although overexpression of the ctcC, which encodes a ribosomal protection protein, enhancing DMCTC biosynthesis in S. aureofaciens DT1, the improvement was limited compared with that achieved by ctcB overexpression. This is the first study to identify the role of ctcB and ctcC in DMCTC accumulation; these genes may also be ideal candidate targets for facilitating DMCTC production by other Streptomyces strains.

Magnetic graphene oxide-biomass activated carbon composite for dye removal

Tan Yan Ying,Abdul Aziz Abdul Raman,Mustapha Mohammed Bello,Archina Buthiyappan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

A magnetic composite was synthesized using palm kernel shell-based activated carbon, graphene oxide (GO) and iron oxide. The morphology, textural properties, magnetic properties, crystal structure and functional groups of the composite were studied. The characterization shows the successful formation of the ternary composite with a high specific surface area (280.39m2/g) and abundant surface functional groups. The magnetic properties of the composite indicate a saturation magnetization of 33.72 emu/g, signifying that the composite can be easily separated with an external magnetic field. The performance of the composite was then investigated through the removal of an anionic azo dye, Acid Blue 113, from aqueous solution. The effect of initial pH of the solution, adsorbent dosage and adsorption contact time was studied. The composite achieved an adsorption capacity of 32.2mg/g and 96.3% dye removal. Effective dye removal was still achieved after five cycles of adsorption-regeneration, with the dye removal of 74% after the fifth cycle. The analyses of adsorption isotherm and kinetics show that the adsorption process fits pseudo-secondorder kinetic and Langmuir isotherm models, indicating a monolayer chemisorption process. The excellent adsorption performance and reusability of the composite and its magnetic separability signify its potential as an adsorbent for wastewater treatment.

Analysis of Free Amino Acids during Fermentation by Bacillus subtilis Using Capillary Electrophoresis

Yanli Ren,Jinyan Zhou,Xiaoyong Zhang,Zhidong Li,Juan Zhong,Jie Yang,Tan Xu,Hong Tan 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.6

A high performance capillary electrophoresis (HPCE) method was presented to identify and quantitate free amino acids during fermentation by Bacillus subtilis. Amino acids, pre-column derivatized with phenylisothicyanate,were separated and characterized by HPCE. In order to optimize separation conditions, the assay was developed by varying the β-cyclodextrin concentration and pH of the background electrolyte. A buffer system comprising 30 mM phosphate and 3 mM β-cyclodextrin at pH 7.0, voltage of 20 kV and detection wavelength of 254 nm showed the best results, with 17 out of 20phenylthioncarbamyl amino acids in a solution adequately separated. For quantification, p-aminobenzoic acid was added as an internal standard. Analysis of free amino acids in Bacillus subtilis culture medium using this method revealed good consistency with the values obtained using conventional ninhydrin-based amino acid analyzer. Four free amino acids (aspartic acid, glutamic acid, proline, and tyrosine) concentration in an extracellular matrix during fermentation by Bacillus subtilis were mainly monitored using this method.

Comparative Evaluation of Three Purification Methods for the Nucleocapsid Protein of Newcastle Disease Virus from Escherichia coli Homogenates

Tan Yan Peng,Ling Tau Chuan,Yusoff Khatijah,Tan Wen Siang,Tey Beng Ti The Microbiological Society of Korea 2005 The journal of microbiology Vol.43 No.3

In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with $Ni^{2+}$ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was $1.26\%$ and $5.56\%$, respectively. It was demonstrated that EBA achieved the highest final protein yield of $9.6\%$ with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.

Asymmetric Exchange Rate Pass-through into Korea’s Export Prices to China : An Industry Level Analysis

Yan Tan,Utai Uprasen 한국무역연구원 2018 무역연구 Vol.14 No.3

This paper analyzes the ERPT (Exchange Rate Pass-Through) into Korea’s aggregate export price and prices of 18 industries to China, under the HS (Harmonized System) classification, utilizing monthly data from July 2005 to November 2017. By adopting the bound test, long-term co-integration relationships have been established in 17 industries, when assuming symmetric ERPT effects. All industries are co-integrated in the long-run when assuming the ERPT effects are asymmetric. By employing linear ARDL (Auto Regressive Distributed Lag) and nonlinear ARDL model, the estimation results show that the ERPT into Korea’s aggregate export prices to China is -0.38. The degree of ERPT effects varies across industries. Asymmetric ERPT effects into Korea’s export prices to China are detected in most of the industries. Our findings suggest that exchange rate policies are crucial to adjust Korea-China export prices. Pricing power should be enhanced in some less competitive industries.

Comparative Evaluation of Three Purification Methods for the NucleocapsidProtein of Newcastle Disease Virus from Escherichia coli Homogenates

Yan Peng Tan,Tau Chuan Ling,Khatijah Yusoff,Wen Siang Tan,Beng Ti Tey 한국미생물학회 2005 The journal of microbiology Vol.43 No.3

In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with Ni2+ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was 1.26% and 5.56%, respectively. It was emonstrated that EBA achieved the highest final protein yield of 9.6% with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.