Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
Add more filters










Publication year range
1.
Crit Care Med ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38912886

ABSTRACT

OBJECTIVES: Catheter malposition after subclavian venous catheterization (SVC) is not uncommon and can lead to serious complications. This study hypothesized that the left access is superior to the right access in terms of catheter malposition after ultrasound-guided infraclavicular SVC due to the asymmetry of the bilateral brachiocephalic veins. DESIGN: Parallel-armed randomized controlled trial. SETTING: A tertiary referral hospital in Korea. PATIENTS: Patients 20-79 years old who were scheduled to undergo SVC under general anesthesia. INTERVENTIONS: Patients were randomly assigned to either the left (n = 224) or right (n = 225) SVC group. The primary outcome measure was the overall catheter malposition rate. The secondary outcome measures included catheter malposition rates into the ipsilateral internal jugular and contralateral brachiocephalic veins, other catheterization-related complications, and catheterization performance. MEASUREMENTS AND MAIN RESULTS: The catheter malposition rate was lower (10 [4.5%] vs. 31 [13.8%], p = 0.001), especially in the ipsilateral internal jugular vein (9 [4.0%] vs. 24 [10.7%], p = 0.007), in the left SVC group than in the right SVC group. In the left SVC group, catheterization success rates on the first pass (88 [39.3%] vs. 65 [28.9%], p = 0.020) and first-catheterization attempt (198 [88.4%] vs. 181 [80.4%], p = 0.020) were higher whereas times for vein visualization (30 s [18-50] vs. 20 s [13-38], p < 0.001) and total catheterization (134 s [113-182] vs. 132 s [103-170], p = 0.034) were longer. There were no significant differences in other catheterization performance and catheterization-related complications between the two groups. CONCLUSIONS: These findings strengthen the rationale for choosing the left access over the right access for ultrasound-guided infraclavicular SVC.

2.
JACC Asia ; 4(4): 265-274, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38660103

ABSTRACT

Background: Systematic COronary Risk Evaluation 2 (SCORE2) and SCORE2-Older Persons (OP) models have been proposed as new cardiovascular risk evaluation tools. Objectives: This study evaluated the performance of SCORE/SCORE-OP and SCORE2/SCORE2-OP in the East Asian population by using population-based cohort data from the National Health Insurance Service (NHIS) Health Screening Cohort of Korea. Methods: A total of 324,384 NHIS examinees from 2004 to 2005 were divided into 5 age groups: 40-49 years, 50-59 years, 60-69 years,70-79 years, and more than 80 years. The examinees had their predicted cardiovascular disease risks calculated by using SCORE, SCORE2, SCORE-OP, and SCORE2-OP models. The low-risk model was applied on the basis of the cohort's observed event rates. The observed and predicted cardiovascular risks were compared. Results: A total of 324,384 subjects were included (mean age 51.4 ± 7.3 years; women, 37.9% for the SCORE/SCORE2 group and mean age 73.0 ± 2.8 years; women, 47.5% for the SCORE/SCORE2-OP group). Over a median follow-up of 9 years, cardiovascular events occurred in 15.0% and 28.9% in SCORE/SCORE2 and SCORE/SCORE2-OP groups, respectively. The SCORE/SCORE-OP model underestimated cardiovascular disease risk in young men (aged 40-49 years) and women (aged 40-59 years) and overestimated it in older age groups. In contrast, SCORE2/SCORE2-OP invariably overestimated the risk in all age groups and sexes. SCORE2/SCORE2-OP showed no improvement in Harrell's concordance index (C-index) compared with SCORE/SCORE-OP. Calibration plots favored SCORE2 over SCORE but not SCORE2-OP over SCORE-OP. Conclusions: Both SCORE2/SCORE2-OP and SCORE/SCORE-OP overestimated cardiovascular disease risk with low performance. SCORE2/SCORE2-OP showed slight improvement over older versions, but modifications are necessary for the East Asian population.

3.
J Pain Res ; 16: 3881-3893, 2023.
Article in English | MEDLINE | ID: mdl-38026462

ABSTRACT

Purpose: This study aims to analyze global and regional (China, Japan, and South Korea) research on virtual reality (VR) in the field of pain medicine over the past 30 years. Specifically, we quantify VR-related publications, examine the distribution of research topics on chronic and acute pain, and identify trends and future directions. Methods: The Web of Science Core Collection (WoSCC) database was used for bibliometric analysis. This study included articles written in English between 1993 and 2022. The search strategy used predefined terms related to VR and pain. Based on the articles' titles and abstracts, two pain physicians independently reviewed and classified them as acute or chronic pain. Quantitative data on countries, institutions, journals, and research categories were analyzed. VOSviewer software was used for keyword mapping and clustering. Results: We analyzed 808 VR-related articles on pain medicine. Over the past three decades, the number of publications in this field has increased steadily. The United States of America (n = 259) had the highest number of publications. Moreover, China (n = 42), Japan (n = 18), and South Korea (n = 24) also contributed continuously. Acute and chronic pain research accounted for 44.2% and 37.9% of the articles, respectively. The most common acute pain topic was procedure-related (n = 129, 16.0%), whereas the most common chronic pain topic was neuropathic (n = 104, 12.9%). Keywords clustered around neuroscience, pediatric pain management, and chronic pain management. Conclusion: Our study revealed academic achievements and growing interest in VR-related research in pain medicine. Researchers worldwide have shown balanced interest in applying VR technology to acute and chronic pain, with specific contributions from China, Japan, and South Korea. Harnessing VR technology is promising for improving pain management and enhancing patients' quality of life in the field of pain medicine.

4.
Materials (Basel) ; 14(20)2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34683703

ABSTRACT

Porous films of metals and metal oxides exhibit larger surface areas and higher reactivities than those of dense films. Therefore, they have gained growing attention as potential materials for use in various applications. This study reports the use of a modified direct current magnetron sputtering method to form porous Zn-ZnO composite films, wherein a subsequent wet post-oxidation process is employed to fabricate pure porous ZnO films. The porous Zn-ZnO composite films were initially formed in clusters, and evaluation of their resulting properties allowed the optimal conditions to be determined. An oxygen ratio of 0.3% in the argon gas flow resulted in the best porosity, while a process pressure of 14 mTorr was optimal. Following deposition, porous ZnO films were obtained through rapid thermal annealing in the presence of water vapor, and the properties and porosities of the obtained films were analyzed. An oxidation temperature of 500 °C was optimal, with an oxidation time of 5 min giving a pure ZnO film with 26% porosity. Due to the fact that the films produced using this method are highly reliable, they could be employed in applications that require large specific surface areas, such as sensors, supercapacitors, and batteries.

5.
Waste Manag Res ; 38(5): 546-553, 2020 May.
Article in English | MEDLINE | ID: mdl-31973652

ABSTRACT

Anaerobic digestion (AD) is generally considered to be an economic and environmentally friendly technology for treating waste activated sludge, but has some limitations, such as the time it takes for the sludge to be digested and also the ineffectiveness of degrading the solids. Various pre-treatment technologies have been suggested to overcome these limitations and to improve the biogas production rate by enhancing the hydrolysis of organic matter. This paper studies the use of hydrothermal pre-treatment (HTP) for a food waste and sewage sludge mixture (FW-SS mixture) as pre-treatment of co-digestion. The results of the capillary suction time, time to filter, and particle size decreased with increasing HTP temperature. These results of the assessment that was conducted in this study confirm that the HTP process indeed modifies the physical properties of the FW-SS mixture to enhance the solubilization of organic solids. A maximum increase in biogas production of 50% is achieved with a HTP temperature of 140oC. These findings show that to achieve high conversion efficiency, an accurately designed pre-treatment step must be included in the overall AD process for wastewater treatment.


Subject(s)
Refuse Disposal , Sewage , Anaerobiosis , Biofuels , Bioreactors , Food , Methane , Waste Disposal, Fluid
6.
J Environ Manage ; 249: 109397, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31442907

ABSTRACT

In this study, the optimum conditions of thermal-alkali pre-treatment and the performance of ammonia stripping were investigated for improving solubilization efficiency and methane yield in the anaerobic co-digestion of food waste (FW) and sewage sludge (SS). The reaction temperature, NaOH concentration and reaction time for the thermal-alkali pre-treatment were investigated to determine optimum pre-treatment conditions. Solubilization rate, volatile suspended solids (VSS) reduction rate and total volatile fatty acid (VFAs) yields were improved with increasing reaction temperature, NaOH concentration and reaction time. In addition, by applying the optimum pre-treatment conditions (140 °C, 60 meq/L and 60 min), the experimental methane yield of thermal-alkali pre-treatment of a mixture of FW and SS was 483.0 ±â€¯15.7 mL CH4/g VSadded, which was about 84% higher than that of the untreated one. However, after thermal-alkali pre-treatment, the NH4+ concentration of the thermal-alkali pre-treatment liquid showed a concentration that could inhibit anaerobic digestion, so ammonia stripping was performed to remove NH4+. As a result, the experimental methane yield was increased by about 7% compared to when ammonia stripping was not performed.


Subject(s)
Bioreactors , Sewage , Anaerobiosis , Food , Methane
7.
Waste Manag Res ; 36(6): 535-540, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29775140

ABSTRACT

This study is an assessment of the hydrothermal carbonisation of poultry slaughterhouse wastes sludge for the solid recovered fuel. The effects of hydrothermal carbonisation were evaluated by varying the reaction temperatures in the range of 170 °C-220 °C. After hydrothermal carbonisation was completed, the capillary suction time, time to filter, and particle size decreased by ranges of 170.4 to 25.9 s, 40 to 7.0 s, and 220 to 98 um, respectively, with increasing hydrothermal carbonisation temperature. This effect improved the dewaterability to release additional free water from the sludge. Moreover, hydrothermal carbonisation increased the heating value though the reduction of the hydrogen and oxygen content of solid fuel in addition to investigating drying performance. As shown in the Van Krevelen diagram, the H/C and O/C ratios decreased, in correlation with primary reactions of coalification. These results suggest that the hydrothermal carbonisation process is an advantageous technology in improving the properties of poultry slaughterhouse wastes as an alternative solid recovered fuel by converting the physical and chemical structure of the poultry slaughterhouse wastes in addition to also providing other benefits to treat organic and biomass waste.


Subject(s)
Abattoirs , Poultry , Refuse Disposal , Animals , Biomass , Incineration , Sewage , Temperature
8.
Waste Manag ; 64: 327-332, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28347587

ABSTRACT

This study is an assessment of the hydrothermal pre-treatment (HTP) of poultry slaughterhouse waste (PSW) sludge for the enhancement of the solubilization, physical properties, and biogas production through anaerobic digestion. This assessment was carried out to ascertain the optimal HTP temperature. The solubilization and physical properties efficacy was investigated by capillary suction time (CST), time to filter (TTF), and particle size. In addition, the anaerobic digestion was investigated through biochemical methane potential (BMP) tests and subsequent statistical analysis using the modified Gompertz model. HTP was found to have improved the solubilization of the PSW sludge with increasing HTP temperature. In addition, the results of the CST, TTF, and particle size decreased with increasing HTP temperature. These results of the assessment that was conducted in this study confirm that the HTP process indeed modifies the physical properties of PSWs to enhance the solubilization of organic solids. Nevertheless, the results of the BMP tests and the modified Gompertz model analysis show that the optimal HTP temperature of PSWs for anaerobic digestion is 190°C. These findings show that to achieve high conversion efficiency, an accurately designed pre-treatment step must be included in the overall anaerobic digestion process for wastewater treatment.


Subject(s)
Abattoirs , Biofuels , Bioreactors , Anaerobiosis , Animals , Methane , Poultry , Sewage
9.
Water Sci Technol ; 74(4): 935-42, 2016.
Article in English | MEDLINE | ID: mdl-27533868

ABSTRACT

In this study, we evaluated ammonia toxicity in mesophilic anaerobic digestion at various pH values and total ammonia nitrogen (TAN) concentrations. We performed anaerobic toxicity assays (ATAs) to evaluate the toxicity effects of TAN and pH on mesophilic anaerobic digestion. Modeling based on the results of the ATAs indicated that the specific methanogenic activity (SMA) decreased by 30% at a TAN concentration higher than 3.0 g/L compared to a TAN concentration of 0 g/L. In addition, the highest SMA for a given TAN level (0.5-10.0 g/L) was observed at a pH of around 7.6. The results of bacterial community analyses showed that the diversity and richness of microorganisms with increasing TAN concentration were decreased. Chloroflexi and Synergistetes were the dominant phyla at TAN concentrations less than 3.0 g/L, and Firmicutes was the dominant phylum at TAN concentrations higher than 3.0 g/L, implying that the ammonia toxicity concentration may influence the kind of dominant species. In conclusion, to start a stable mesophilic anaerobic digestion concerning ammonia toxicity, a TAN concentration less than 3.0 g/L is preferable.


Subject(s)
Ammonia/toxicity , Bacteria, Anaerobic/drug effects , Bioreactors/microbiology , Acclimatization , Ammonia/chemistry , Anaerobiosis , Hydrogen-Ion Concentration , Models, Biological
10.
ACS Appl Mater Interfaces ; 8(3): 2027-34, 2016 Jan 27.
Article in English | MEDLINE | ID: mdl-26717009

ABSTRACT

Alpha-phase iron oxide nanoparticles (α-NPs), α-iron oxide hollow nanobarrels (α-HNBs), and α-HNBs on reduced graphene oxide (α-HNBs/RGO) for Li-ion batteries (LIBs) were synthesized by a time-efficient microwave method to improve the low electrical conductivity of iron oxide and exploit the porous structure of RGO, which prevents the volume expansion of α-Fe2O3 during the insertion/extraction. On the other hand, α-HNBs (∼200 nm in diameter, ∼360 nm in length) provide a short diffusion path for Li ions and accommodate the strain generated by the volume change. The α-HNBs/RGO hybrid structure was synthesized by a one-step microwave-assisted hydrothermal method to bond α-HNBs with RGO. The as-prepared α-HNBs/RGO electrode exhibited a superior reversible capacity of 1279 mA h g(-1) at 0.5 C after the first cycle; such a capacity was nearly recovered after numerous cycles (2nd to 100th cycle, 95%). The long-term cyclability of α-HNBs/RGO shows 478 mA h g(-1) after 1000 cycles. Moreover, the α-HNBs/RGO electrode shows a high rate capacity of 403 mA h g(-1) even at 10 C. The α-HNBs/RGO exhibited a better electrochemical performance that could be attributed to the absence of nanoparticle agglomeration and RGO restacking, which provided a buffer effect against the volume expansion, promoted electrical conductivity and high structural integrity.

11.
Water Res ; 68: 580-8, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25462764

ABSTRACT

In this study, the anaerobic digestion of thermally hydrolyzed wasted sludge (THWS) with a high concentration of ammonia was carried out through combining with an ammonia stripping and an electrolyzed water system (EWS). The EWS produced acidic water (pH 2-3) at the anode and alkaline water (pH 11-12) at the cathode with an electro-diaphragm between the electrodes that could be applied to ammonia stripping. The ammonia stripping efficiency was strongly dependent on the pH and aeration rate, and the ammonium ion removal rate followed pseudo-first-order kinetics. From the BMP test, the methane yield of THWS after ammonia stripping using the EWS was 2.8 times higher than that of the control process (raw THWS without ammonia stripping). Furthermore, both methane yield and ammonium removal efficiency were higher in this study than in previous studies. Since ammonia stripping with the EWS does not require any chemicals for pH control, no precipitated sludge is produced and anaerobic microorganisms are not inhibited by cations. Therefore, ammonia stripping using the EWS could be an effective method for digestion of wastewater with a high concentration of ammonium nitrogen.


Subject(s)
Ammonia/chemistry , Sewage/chemistry , Waste Disposal, Fluid/methods , Water/chemistry , Algorithms , Ammonia/metabolism , Anaerobiosis , Bacteria, Anaerobic/metabolism , Electrolysis , Hot Temperature , Hydrogen-Ion Concentration , Hydrolysis , Methane/metabolism , Models, Chemical , Reproducibility of Results , Sewage/microbiology
12.
Environ Technol ; 35(9-12): 1133-9, 2014.
Article in English | MEDLINE | ID: mdl-24701908

ABSTRACT

The anaerobic degradation of each amino acid that could be generated through the hydrolysis of sewage sludge was evaluated. Stickland reaction as an intermediate reaction between two kinds of amino acids was restricted in order to evaluate each amino acid. Changes in the chemical oxygen demand (COD), T-N, NH4(+)-N, biogas, and CH4 were analysed for the anaerobic digestion process. The initial nitrogen concentration of all amino acids is adjusted as 1000 mg/L. The degradation rate of the amino acids was determined based on the ammonia form of nitrogen, which is generated by the deamination of amino acids. Among all amino acids, such as alpha-alanine, beta-alanine, lysine, arginine, glycine, histidine, cysteine, methionine, and leucine, deamination rates of cysteine, leucine, and methionine were just 61.55%, 54.59%, and 46.61%, respectively, and they had low removal rates of organic matter and showed very low methane production rates of 13.55, 71.04, and 80.77 mL CH4/g CODin, respectively. Especially for cysteine, the methane content was maintained at approximately 7% during the experiment. If wastewater contains high levels of cysteine, leucine, and methionine and Stickland reaction is not prepared, these amino acids may reduce the efficiency of the anaerobic digestion.


Subject(s)
Amino Acids/metabolism , Sewage/chemistry , Ammonia/analysis , Anaerobiosis , Biological Oxygen Demand Analysis , Bioreactors , Hydrolysis , Methane/analysis , Nitrogen/analysis
13.
Bioresour Technol ; 151: 78-84, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24211486

ABSTRACT

Compact and structurally stable aerobic granules were developed in a sequencing batch reactor (SBR) at mesophilic temperatures (35°C). The morphological, biological and chemical characteristics of the aerobic granulation were investigated and a theoretical granulation mechanism was proposed according to the results of the investigation. The mature aerobic granules had compact structure, small size (mean diameter of 0.24 mm), excellent settleability and diverse microbial structures, and were effective for the removal of organics and nitrification. The growth kinetics demonstrated that the biomass growth depended on coexistence and interactions between heterotrophs and autotrophs in the granules. The functions of heterotrophs and autotrophs created a compact and secure layer on the outside of the granules, protecting the inside sludge containing environmentally sensitive and slow growing microorganisms. The mechanism and the reactor performance may promise feasibility and efficiency for treating industry effluents at mesophilic temperatures using aerobic granulation.


Subject(s)
Temperature , Wastewater/microbiology , Water Purification/methods , Aerobiosis , Ammonium Compounds/metabolism , Bacteria/growth & development , Bacteria/metabolism , Biomass , Flocculation , Kinetics , Nitrification , Nitrogen/isolation & purification , Organic Chemicals/isolation & purification , Particle Size , Sewage
14.
Appl Radiat Isot ; 81: 298-301, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23548694

ABSTRACT

(24)Na produced by the neutron activation of stable sodium in the body is commonly used to assess neutron doses after criticality accidents. However, the (24)Na distribution is not uniform owing to the interaction with the human body. In this study, we experimentally evaluated the (24)Na distribution in a PMMA water phantom and 60 polyethylene vials. The vials were analyzed to evaluate the sodium activation distribution in the PMMA water phantom by employing a correction factor.


Subject(s)
Biological Assay/methods , Neutrons , Polymethyl Methacrylate/chemistry , Polymethyl Methacrylate/radiation effects , Radiation Monitoring/methods , Sodium Radioisotopes/analysis , Biomimetic Materials/chemistry , Biomimetic Materials/radiation effects , Radiation Dosage , Reproducibility of Results , Scattering, Radiation , Sensitivity and Specificity , Sodium Radioisotopes/radiation effects
15.
Appl Radiat Isot ; 81: 371-3, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23541790

ABSTRACT

On March 11, 2011, as a result of the Great East Japan Earthquake, severe damage to the Fukushima nuclear power plant caused the release of radioactive materials. We conducted radioactive contamination monitoring for Korean residents in Japan and Korean travelers to East Japan after the accident. More than 800 members of the Korean public were surveyed for personal monitoring. Measured levels of external and internal contamination were within the screening levels for each monitoring method.


Subject(s)
Air Pollution, Radioactive/statistics & numerical data , Fukushima Nuclear Accident , Radiation Dosage , Radiation Monitoring/statistics & numerical data , Radioactive Fallout/statistics & numerical data , Radioisotopes/analysis , Whole-Body Counting/statistics & numerical data , Air Pollution, Radioactive/analysis , Humans , Japan , Oceans and Seas , Radioactive Fallout/analysis , Republic of Korea
SELECTION OF CITATIONS
SEARCH DETAIL
...