1.Commentary: polymer binding modules accelerate enzymatic degradation of poly(ethylene terephthalate).
Yi LU ; Ruizhi HAN ; Ulrich SCHWANEBERG ; Yu JI
Chinese Journal of Biotechnology 2023;39(5):1883-1888
The large scale production and indiscriminate use of plastics led to serious environmental pollution. To reduce the negative effects of plastics waste on the environment, an approach of enzymatic degradation was put forward to catalyze plastics degradation. Protein engineering strategies have been applied to improve the plastics degrading enzyme properties such as activity and thermal stability. In addition, polymer binding modules were found to accelerate the enzymatic degradation of plastics. In this article, we introduced a recent work published in Chem Catalysis, which studied the role of binding modules in enzymatic hydrolysis of poly(ethylene terephthalate) (PET) at high-solids loadings. Graham et al. found that binding modules accelerated PET enzymatic degradation at low PET loading (< 10 wt%) and the enhanced degradation cannot be observed at high PET loading (10 wt%-20 wt%). This work is beneficial for the industrial application of polymer binding modules in plastics degradation.
Polyethylene Terephthalates/metabolism*
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Polymers
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Plastics
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Ethylenes
2.Effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell.
Juhyon LEE ; Hyungi MIN ; Juyoung JUNG ; Nara KANG
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2008;34(6):635-639
OBJECTIVES: the effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell were investigated. METHODS: Poly (p-dioxone)-hybrid-Poly (lactide-glycolide) (PPDO-hybrid-PLGA) nanofiber scaffold, fabricated in a tube form with 1.5 mm internal diameter, 0.2 mm thickness and 5 mm length, was prepared using electrospinning method. To study the surface morphology using SEM, The study group and control group in respective were; Control:Non-sterilized scaffold, Group I:scaffold sterilized with 70% Alcohol, Group II: scaffold sterilized with Ethylene Oxide at 65 degrees C, and Group III: scaffold sterilized with Ethylene Oxide at 37 degrees C. To investigate viability of the PC12 cell on the scaffold, The study group and control group in respective were; Control: sterilized with 70% Alcohol, Group I: sterilized with Ethylene Oxide at 65 degrees C, and Group II: sterilized with Ethylene Oxide at 37 degrees C. RESULTS: 1. The surface morphology was slightly changed in Group I, II and GroupIII, compared with control. 2. The attachment of PC12 cells in Group I, II was not higher than in control DISCUSSION: The attachment of PC12 cell is not influenced by different sterilization methods.
Animals
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Ethylene Oxide
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Ethylenes
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Nanofibers
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PC12 Cells
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Sterilization
3.Advances in poly(ethylene terephthalate) hydrolases.
Zhiyi ZHAO ; Guoqiang ZHANG ; Kun LIU ; Shengying LI
Chinese Journal of Biotechnology 2023;39(5):1998-2014
Plastics have brought invaluable convenience to human life since it was firstly synthesized in the last century. However, the stable polymer structure of plastics led to the continuous accumulation of plastic wastes, which poses serious threats to the ecological environment and human health. Poly(ethylene terephthalate) (PET) is the most widely produced polyester plastics. Recent researches on PET hydrolases have shown great potential of enzymatic degradation and recycling of plastics. Meanwhile, the biodegradation pathway of PET has become a reference model for the biodegradation of other plastics. This review summarizes the sources of PET hydrolases and their degradation capacity, degradation mechanism of PET by the most representative PET hydrolase-IsPETase, and recently reported highly efficient degrading enzymes through enzyme engineering. The advances of PET hydrolases may facilitate the research on the degradation mechanism of PET and further exploration and engineering of efficient PET degradation enzymes.
Humans
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Hydrolases/metabolism*
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Polyethylene Terephthalates/metabolism*
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Plastics/metabolism*
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Ethylenes
4.Health Risk Assessment of Lead Ingestion Exposure by Particle Sizes in Crumb Rubber on Artificial Turf Considering Bioavailability.
Sunduk KIM ; Ji Yeon YANG ; Ho Hyun KIM ; In Young YEO ; Dong Chun SHIN ; Young Wook LIM
Environmental Health and Toxicology 2012;27(1):e2012005-
OBJECTIVES: The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. METHODS: This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. RESULTS: As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be 1.56x10(-4) mg/kg-day for low grade elementary school students and 4.87x10(-5) mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. CONCLUSIONS: Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller.
Alkenes
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Biological Availability
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Digestion
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Eating
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Ethylenes
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Humans
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Particle Size
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Risk Assessment
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Rubber
5.The Clinical Significance of Reuse Disposable Instruments for Laparoscopic Surgery.
Yi Ho LEE ; Jong Woo KIM ; Chul Woon CHUNG ; Seong Geun HONG
Journal of the Korean Society of Endoscopic & Laparoscopic Surgeons 2011;14(1):17-21
PURPOSE: Laparoscopic instruments have been remarkably developed through many trials. Various studies and experiments on laparoscopic instruments are underway in other countries. Laparoscopic surgery is also very actively applied in Korea. However, research on the use and safety of the instruments is stagnant. Furthermore, reuse of some disposable laparoscopic instruments is frequently observed, but there are only rare studies on the safety of this. Thus, we tried to provide study cases on the safety of repeated use of disposable laparoscopic instruments. METHODS: To investigate the effectiveness of sterilization and a re-package procedure, we divided the laparoscopic instruments that are commonly used in our institution into 10 types. Among all the available instruments, 32 instruments were selected for the simulation experiment. Each instrument was sterilized using ethylene oxide gas or glutaraldehyde 2%, and then packaged. Then, each was observed grossly and microscopically under aseptic conditions and we looked for any remnant foreign body or contaminant. When remnant foreign body or contaminant was found, they were collected and separately cultured. RESULTS: Residual contaminants were found in 15 instruments (46.9%) out of a total of 32 and microorganisms, including coagulase-negative staphylococcus and gamma-hemolytic streptococcus, were cultured from (9.38%), and each had different types of microorganisms. CONCLUSION: It is remarkable that the bacteria were cultured from recycled laparoscopic instruments after sterilization. The reuse of laparoscopic instruments might be cost-effective, but further studies on its safety are required. Moreover, careful inspection on the method of surgical instrument sterilization in each institution will be necessary.
Bacteria
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Ethylene Oxide
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Ethylenes
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Foreign Bodies
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Glutaral
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Korea
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Laparoscopy
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Staphylococcus
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Sterilization
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Streptococcus
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Surgical Instruments
6.Drug induced Pulmonary Edema.
Si Han SUNG ; Hye Young JANG ; Hoon LIM
Journal of The Korean Society of Clinical Toxicology 2010;8(2):113-121
PURPOSE: Drug-induced non-cardiogenic pulmonary edema has been reported on in a drug case series. For most of the agents that cause pulmonary edema, the pathogenic mechanisms that are responsible for the pulmonary edema remain unknown. We report here on the cases of suspected drug-induced pulmonary edema and we analyze the clinical characteristics. METHODS: We reviewed the medical records of 1,345 patients who had drug adverse effects and drug poisoning from January 2005 to July 2010, and 480 of these patients were admitted to the EM Department. Among them, 17 patients developed abnormal chest radiological findings and they were analyzed for any clinical characteristics, the initial symptoms, securing the airway and the clinical results. RESULTS: Seventeen patients out of 480 (3.54%) developed drug-induced abnormal chest radiographic pulmonary edema; they displayed initial symptoms that included mental change (41.2%), dyspnea (17.6%), vomiting (11.8%), etc, and some displayed no symptoms at all (11.8%). Only 3 patients out of the 11 who died or had severe pulmonary edema were able to obtain an advanced airway prior to their arrival to the EM Department. Clinical recovery was generally rapid and this was mostly completed within 6 hours. The mortality rate was 11.8% (2 of 17 patients), and the causative drugs were found to be propofol (35.3%, 6 of 17 patients), multiple drugs (41.2% or 7 out of 17) and one patient each with ephedrine, ethylene glycol, doxylamine and an unknown drug, respectively. CONCLUSION: Drug-induced pulmonary edema and deaths are not uncommon, and recovery is typically rapid with few long-term sequelae when drug administration is discontinued. Oxygen therapy and securing the airway must be performed during transportation for patients with pulmonary edema.
Doxylamine
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Dyspnea
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Ephedrine
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Ethylene Glycol
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Ethylenes
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Humans
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Medical Records
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Oxygen
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Propofol
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Pulmonary Edema
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Thorax
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Transportation
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Vomiting
7.Diosmin Reduces Calcium Oxalate Deposition and Tissue Degeneration in Nephrolithiasis in Rats: A Stereological Study.
Ali NOORAFSHAN ; Saied KARBALAY-DOUST ; Fatemeh KARIMI
Korean Journal of Urology 2013;54(4):252-257
PURPOSE: Kidney stones (nephrolithiasis) are a widespread disease. Thus, blocking stone formation and finding new therapeutic methods is an important area of study. Diosmin (a major component of the bile) is known to have antioxidant as well as renoprotective effects. The present investigation aimed to evaluate the effect of diosmin on renal tissue protection in rats with ethylene glycol-induced nephrolithiasis. MATERIALS AND METHODS: The rats were randomly divided into three groups. Group one (control) did not receive any treatments. In groups two and three, nephrolithiasis was induced by 2.5% (V/V) ethylene glycol + 2.5% (W/V) ammonium chloride (2 mL/d). The second and the third groups received distilled water or diosmin (80 mg/kg/d) by gavage for 21 days. RESULTS: Stereological estimation of the renal structures revealed that the average volume of calcium oxalate (CaOx) in the nephrolithiasis+diosmin rats was -63% less than in the rats with untreated nephrolithiasis (p<0.01). The volume of the glomeruli, proximal and distal convoluted tubules, Henle's loop, collecting ducts, and vessels was reduced -32% to 58% after the induction of nephrolithiasis (p<0.001). In the nephrolithiasis+diosmin rats, on average, -70% to 96% of the glomeruli, proximal convoluted tubules, Henle's loop collecting ducts, and vessels remained intact (p<0.01). Degeneration of the cortical tissue was 5-fold that of the medulla. In the nephrolithiasis+diosmin rats, degeneration in the renal cortical tissue and medulla was reduced -70% and 44%, respectively, compared with that in the untreated nephrolithiasis group (p<0.01). CONCLUSIONS: Diosmin reduces CaOx deposition and the degeneration of glomeruli and tubules in a rat model of nephrolithiasis.
Ammonium Chloride
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Animals
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Calcium
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Calcium Oxalate
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Diosmin
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Ethylene Glycol
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Ethylenes
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Kidney Calculi
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Nephrolithiasis
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Rats
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Water
8.Two Cases of Ethylene Glycol Poisoning.
Jae Jin KIM ; Sung Hyun YUN ; Hyun Min JUNG ; Ji Hye KIM ; Seung Baik HAN ; Jun Sig KIM ; Jin Hui PAIK
Journal of The Korean Society of Clinical Toxicology 2013;11(1):36-40
Ethylene glycol poisoning is treated mainly by alcohol dehydrogenase inhibition therapy and hemodialysis. Early recognition and initiation of treatment is important because toxic metabolites increase over time by hepatic metabolism; however, there is no confirmative diagnostic tool in our clinical setting. Therefore, diagnosis is dependent on history, high anion gap acidosis, high osmolal gap, etc.. Diagnosis and treatment are delayed in cases where history taking is not possible, such as a mental changed patient. Authors report on two cases of ethylene glycol poisoning by contrasting clinical outcomes, demonstrating the importance of early diagnosis and treatment for achievement of a good outcome.
Achievement
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Acid-Base Equilibrium
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Acidosis
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Alcohol Dehydrogenase
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Early Diagnosis
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Ethylene Glycol
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Ethylenes
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Osmolar Concentration
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Renal Dialysis
9.Optimization of ethylene production from ethanol dehydration using Zn-Mn-Co/HZSM-5 by response surface methodology.
Wei WANG ; Keke CHENG ; Jianwei XUE ; Jian'an ZHANG
Chinese Journal of Biotechnology 2011;27(3):412-418
The effects of reaction temperature, ethanol concentration and weight hourly space velocity (WHSV) on the ethylene production from ethanol dehydration using zinc, manganese and cobalt modified HZSM-5 catalyst were investigated by response surface methodology (RSM). The results showed that the most significant effect among factors was reaction temperature and the factors had interaction. The optimum conditions were found as 34.4% ethanol concentration, 261.3 0 degrees C of reaction temperature and 1.18 h(-1) of WHSV, under these conditions the yield of ethylene achieved 98.69%.
Catalysis
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Cobalt
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chemistry
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Dehydration
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Ethanol
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chemistry
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Ethylenes
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chemistry
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metabolism
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Manganese
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chemistry
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Zeolites
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chemistry
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Zinc
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chemistry
10.A Case of Acetone Intoxication Misdiagnosed as Diabetic Ketoacidosis.
Na Young KIM ; Ik Hyun JO ; Su Sun CHANG ; Eun Hee JANG ; Mee Kyoung KIM ; Ki Hyun BAEK ; Ki Ho SONG ; Kwang Woo LEE ; Hyuk Sang KWON
Journal of Korean Diabetes 2011;12(4):245-247
Diabetic ketoacidosis (DKA) is one of the most serious acute metabolic complications of diabetes. The triad of uncontrolled hyperglycemia, metabolic acidosis, and increased total body ketone concentration characterizes DKA. Not all patients with ketoacidosis have DKA, and other situations can result in metabolic acidosis and ketonemia, like starvation ketosis, alcoholic ketoacidosis or ingestion of drugs such as salicylate, methanol, ethylene glycol. We report a case of acetone intoxication that was misdiagnosed as diabetic ketoacidosis.
Acetone
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Acidosis
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Alcoholics
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Diabetic Ketoacidosis
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Eating
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Ethylene Glycol
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Ethylenes
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Humans
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Hyperglycemia
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Ketosis
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Methanol
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Starvation