Publications by authors named "Sang Gil Lee"

121 Publications

AB-stacked nanosheet-based hexagonal boron nitride.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2021 Apr 17;77(Pt 2):260-265. Epub 2021 Mar 17.

Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.

Hexagonal boron nitride (h-BN) has been generally interpreted as having an AA stacking sequence. Evidence is presented in this article indicating that typical commercial h-BN platelets (∼10-500 nm in thickness) exhibit stacks of parallel nanosheets (∼10 nm in thickness) predominantly in the AB sequence. The AB-stacked nanosheet occurs as a metastable phase of h-BN resulting from the preferred texture and lateral growth of armchair (110) planes. It appears as an independent nanosheet or unit for h-BN platelets. The analysis is supported by simulation of thin AB films (2-20 layers), which explains the unique X-ray diffraction pattern of h-BN. With this analysis and the role of pressure in commercial high-pressure high-temperature sintering (driving nucleation and parallelizing the in-plane crystalline growth of the nuclei), a growth mechanism is proposed for 2D h-BN (on a substrate) as `substrate-induced 2D growth', where the substrate plays the role of pressure.
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http://dx.doi.org/10.1107/S2052520621000317DOI Listing
April 2021

Single- or double-membrane-bound vesicles and P, Ca, and Fe-containing granules in Xanthomonas citri cultured on a solid medium.

Micron 2021 04 27;143:103024. Epub 2021 Jan 27.

Department of Ecology and Environmental System, Kyungpook National University, Sangju, 37224, South Korea; Tree Diagnostic Center, Kyungpook National University, Sangju, 37224, South Korea. Electronic address:

The organelle-like structures of Xanthomonas citri, a bacterial pathogen that causes citrus canker, were investigated using an analytical transmission electron microscope. After high-pressure freezing, the bacteria were then freeze-substituted for imaging and element analysis. Miniscule electron-dense structures of varying shapes without a membrane enclosure were frequently observed near the cell poles in a 3-day culture. The bacteria formed cytoplasmic electron-dense spherical structures measuring approximately 50 nm in diameter. Furthermore, X. citri produced electron-dense or translucent ellipsoidal intracellular or extracellular granules. Single- or double-membrane-bound vesicles, including outer-inner membrane vesicles, were observed both inside and outside the cells. Most cells had been lysed in the 3-week X. citri culture, but they harbored one or two electron-dense spherical structures. Contrast-inverted scanning transmission electron microscopy images revealed distinct white spherical structures within the cytoplasm of X. citri. Likewise, energy-dispersive X-ray spectrometry showed the spatial heterogeneity and co-localization of phosphorus, oxygen, calcium, and iron only in the cytoplasmic electron-dense spherical structures, thus corroborating the nature of polyphosphate granules.
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http://dx.doi.org/10.1016/j.micron.2021.103024DOI Listing
April 2021

Development of Korean CARcinogen EXposure: An Initiative of the Occupational Carcinogen Surveillance System in Korea.

Ann Work Expo Health 2021 Feb 2. Epub 2021 Feb 2.

Department of Environmental Health, Korea National Open University, Seoul, Korea.

Objective: To prevent occupational cancers, carcinogen exposure surveillance systems have been developed in many countries. This study aimed to develop a carcinogen exposure database specific to South Korea.

Methods: Twenty known human carcinogens were selected for this study. The International Standard Classification of Industry was used for a classification scheme of industries. Three nationwide occupational exposure databases, the Work Environment Measurement Database, the Special Health Examination Database, and the Work Environment Condition Survey, were used to calculate reference exposure prevalence estimates by carcinogen and industry. Then, 37 professional industrial hygienists with at least 19 years of field experience provided their own exposure prevalence estimates, after reviewing the abovementioned reference estimates derived from three data sources. The median value of the experts' estimates was used as the final exposure prevalence. Finally, the number of exposed workers was computed by multiplying the final exposure prevalence by the number of workers extracted from the 2010 national census data by carcinogen and industry.

Results: The exposure prevalence and the number of exposed workers were calculated according to 20 carcinogen and 228 minor industrial groups, assuming year 2010 circumstances. The largest population was exposed to welding fumes (326 822 workers), followed by ultraviolet radiation (238 937 workers), ionizing radiation (168 712 workers), and mineral oil mist (146 798 workers).

Conclusions: Our results provide critical data on carcinogen exposure for the prevention of occupational cancers.
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http://dx.doi.org/10.1093/annweh/wxaa135DOI Listing
February 2021

Potential Anti-Aging Substances Derived from Seaweeds.

Mar Drugs 2020 Nov 18;18(11). Epub 2020 Nov 18.

Department of Food Science and Nutrition, Pukyong National University, Busan 48513, Korea.

Aging is a major risk factor for many chronic diseases, such as cancer, cardiovascular disease, and diabetes. The exact mechanisms underlying the aging process are not fully elucidated. However, a growing body of evidence suggests that several pathways, such as sirtuin, AMP-activated protein kinase, insulin-like growth factor, autophagy, and nuclear factor erythroid 2-related factor 2 play critical roles in regulating aging. Furthermore, genetic or dietary interventions of these pathways can extend lifespan by delaying the aging process. Seaweeds are a food source rich in many nutrients, including fibers, polyunsaturated fatty acids, vitamins, minerals, and other bioactive compounds. The health benefits of seaweeds include, but are not limited to, antioxidant, anti-inflammatory, and anti-obese activities. Interestingly, a body of studies shows that some seaweed-derived extracts or isolated compounds, can modulate these aging-regulating pathways or even extend lifespans of various animal models. However, few such studies have been conducted on higher animals or even humans. In this review, we focused on potential anti-aging bioactive substances in seaweeds that have been studied in cells and animals mainly based on their anti-aging cellular and molecular mechanisms.
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http://dx.doi.org/10.3390/md18110564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698806PMC
November 2020

The use of autologous free vascularized fibula grafts in reconstruction of the mobile spine following tumor resection: surgical technique and outcomes.

J Neurosurg Spine 2020 Nov 6:1-10. Epub 2020 Nov 6.

Departments of1Orthopedic Surgery, Orthopedic Oncology Service.

Objective: Reconstruction of the mobile spine following total en bloc spondylectomy (TES) of one or multiple vertebral bodies in patients with malignant spinal tumors is a challenging procedure with high failure rates. A common reason for reconstructive failure is nonunion, which becomes more problematic when using local radiation therapy. Radiotherapy is an integral part of the management of primary malignant osseous tumors in the spine. Vascularized grafts may help prevent nonunion in the radiotherapy setting. The authors have utilized free vascularized fibular grafts (FVFGs) for reconstruction of the spine following TES. The purpose of this article is to describe the surgical technique for vascularized reconstruction of defects after TES. Additionally, the outcomes of consecutive cases treated with this technique are reported.

Methods: Thirty-nine patients were treated at the authors' tertiary care institution for malignant tumors in the mobile spine using FVFG following TES between 2010 and 2018. Postoperative union, reoperations, complications, neurological outcome, and survival were reported. The median follow-up duration was 50 months (range 14-109 months).

Results: The cohort consisted of 26 males (67%), and the median age was 58 years. Chordoma was the most prevalent tumor (67%), and the lumbar spine was most affected (46%). Complete union was seen in 26 patients (76%), the overall complication rate was 54%, and implant failure was the most common complication, with 13 patients (33%) affected. In 18 patients (46%), one or more reoperations were needed, and the fixation was surgically revised 15 times (42% of reoperations) in 10 patients (26%). A reconstruction below the L1 vertebra had a higher proportion of implant failure (67%; 8 of 12 patients) compared with higher resections (21%; 5 of 24 patients) (p = 0.011). Graft length, number of resected vertebrae, and docking the FVFG on the endplate or cancellous bone was not associated with union or implant failure on univariate analysis.

Conclusions: The FVFG is an effective reconstruction technique, particularly in the cervicothoracic spine. However, high implant failure rates in the lumbar spine have been seen, which occurred even in cases in which the graft completely healed. Methods to increase the weight-bearing capacity of the graft in the lumbar spine should be considered in these reconstructions. Overall, the rates of failure and revision surgery for FVFG compare with previous reports on reconstruction after TES.
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http://dx.doi.org/10.3171/2020.6.SPINE20521DOI Listing
November 2020

Evaluation of the Seesaw Test as New Diagnostic Test for Thumb CMC Osteoarthritis.

Hand (N Y) 2020 Aug 26:1558944720948239. Epub 2020 Aug 26.

Massachusetts General Hospital, Boston, MA, USA.

Background: The seesaw test consists of flexion and extension of the thumb metacarpal on the trapezium, with continuous axial pressure to keep the metacarpal base reduced in the carpometacarpal (CMC) joint. We aim to evaluate this maneuver compared with the grind test.

Methods: We prospectively enrolled 80 participants from March 2017 to March 2018 at a single institution, excluding those who had previous thumb surgery or pathology. Each participant underwent both seesaw and grind tests by 2 independent examiners. We included 24 patients with a mean age of 73 years in the CMC osteoarthritis group (Eaton stages 2-4) and 44 patients with a mean age of 66 years in the control group (Eaton stages 0 and 1). We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and multirater κ measure.

Results: The seesaw test had a higher sensitivity than the grind test (42%-71% vs 13%-17%), but a lower specificity (82%-86% vs 91%-98%). The PPV was more consistent between examiners for the seesaw test (63%-68% vs 42%-80%), and the NPV was higher (73%-84% vs 66%-68%). There was a slight agreement between the attending surgeon and the fellow performing the grind test (κ = 0.08) and a moderate agreement between the attending surgeon and the fellow performing the seesaw test (κ = 0.59).

Conclusions: The seesaw test is superior to the grind test, with a much higher sensitivity, slightly lower specificity, more consistent PPV, and slightly higher NPV. Therefore, the seesaw test could be a valuable addition or even replacement for the grind test, and we recommend considering it in daily practice.
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http://dx.doi.org/10.1177/1558944720948239DOI Listing
August 2020

Free Vascularized Fibula Graft with Femoral Allograft Sleeve for Lumbar Spine Defects After Spondylectomy of Malignant Tumors: A Case Report.

JBJS Case Connect 2020 Jul-Sep;10(3):e2000075

1Department of Orthopedic Surgery, Orthopedic Oncology Service, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 2Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 3Department of Vascular Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 4Division of Thoracic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 5Department of Orthopedic Surgery, Hand and Upper Extremity Service, Orthopedic Oncology Service, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.

Case: We present a 65-year-old man with an L4 conventional chordoma. Total en bloc spondylectomy (TES) of the involved vertebral bodies and surrounding soft tissues with reconstruction of the spine using a free vascularized fibula autograft (FVFG) is a proven technique, limiting complications and recurrence. However, graft fracture has occurred only in the lumbar spine in our institutional cases. We used a technique in our patient to ensure extra stability and support, with the addition of a femoral allograft sleeve encasing the FVFG.

Conclusions: Our technique for the reconstruction of the lumbar spine after TES of primary malignant spinal disease using a femoral allograft sleeve encasing the FVFG is viable to consider.
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http://dx.doi.org/10.2106/JBJS.CC.20.00075DOI Listing
August 2020

Reoperation Rate and Indication for Reoperation after Free Functional Muscle Transfers in Traumatic Brachial Plexus Injury.

Arch Bone Jt Surg 2020 May;8(3):368-372

Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA.

Background: Free functional gracilis muscle transfers (FFGT) are an option for reconstruction after traumatic brachial plexus injury. Few studies report the rate of revision surgeries following free functional muscle transfers. We examined the reoperation rate and indication for reoperation after primary reconstruction of upper extremity function with a free gracilis transfer after brachial plexus injury.

Methods: From 2003-2016, we identified 25 patients who underwent a free functional gracilis muscle transfer for restoration of upper extremity function. We reviewed their medical charts to record patient, injury, and treatment characteristics. Indication for reoperation and reoperative procedure were also identified.

Results: Fourteen out of 25 patients (56%) had a reoperation after FFGT. Four flaps were re-explored for vascular compromise, but there were no flap failures. The majority of reoperations involved adjustment of tendon excursion (8/14) which demonstrated that tenolysis was the main procedure.

Conclusion: Despite promising results of free functional gracilis transfers, reoperation is relatively common and should be discussed with the patient as a preoperative strategy. Early exploration of vascular compromise may decrease the flap failure. Poor tendon excursion is a common unpredicted consequence after FFMT and is the main indication for reoperation.
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http://dx.doi.org/10.22038/abjs.2019.41123.2113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7358244PMC
May 2020

Anti-Inflammatory and Antioxidant Effects of Anthocyanins of (Red Clover) in Lipopolysaccharide-Stimulated RAW-267.4 Macrophages.

Nutrients 2020 Apr 15;12(4). Epub 2020 Apr 15.

Food and Nutritional Sciences, Department of Family and Consumer Sciences, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA.

Red clover () possesses various dietary compounds that improve human health. However, the functions of anthocyanins in red clover remain unclear. Here we examined anti-inflammatory and antioxidant effects of red clover extract (RC) and red clover anthocyanins fraction (RCA) using lipopolysaccharide (LPS)-treated RAW 264.7 macrophages and identified dietary compounds. RC and RCA suppressed LPS-induced expression of genes such as tumor necrosis factor (), interleukin (), inducible nitric oxide synthase (), monocyte chemoattractant protein ()1, and cyclooxygenase (). LPS-stimulated intracellular reactive oxygen species (ROS) production also was prevented by both RC and RCA. NADPH oxidase 1 (NOX1) gene and phosphorylation of p47 of NOX1 that were increased by LPS were inhibited in the cells treated with RCA. LPS-stimulated nuclear factor erythroid 2-related factor 2 () gene expression and nuclear translocation of nuclear factor kappa B (NF-kB) subunit p65 were suppressed together with reduced iNOS and COX2 proteins by RCA. Additionally, 27 polyphenols and 7 anthocyanins from RC were identified and quantified. In conclusion, RC, especially RCA, exerted anti-inflammatory and anti-oxidative activities in vitro by regulating NF-κB and NRF2 signaling pathways, suggesting that anthocyanins in red clover are the potential candidates to reduce inflammation and oxidative stress.
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http://dx.doi.org/10.3390/nu12041089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7230587PMC
April 2020

Obesity status is a risk factor for secondary surgery after neurolysis, direct nerve repair or nerve grafting in traumatic brachial plexus injury: a retrospective cohort study.

BMC Surg 2020 Apr 15;20(1):73. Epub 2020 Apr 15.

Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA.

Background: The objective of the study was to investigate the association between obesity and the presence of secondary surgery following neurolysis, direct nerve repair, or nerve grafting in patients with traumatic brachial plexus injury.

Methods: In this retrospective chart review spanning two Level I medical centers in a single metropolitan area, 57 patients who underwent neurolysis, direct nerve repair, or nerve grafting for brachial plexus injuries between 2002 and 2015 were identified. Risk regression analysis was used to evaluate the association between obesity status and secondary surgery.

Results: After controlling for the confounding variables of age, high energy injury, associated shoulder dislocation and associated clavicle fracture using multivariate regression (risk regression), the risk ratio of secondary surgery in obese patients compared to non-obese patients was 6.99 (P = 0.028). The most common secondary surgery was tendon or local muscle transfer.

Conclusions: There is an increased risk of secondary surgery in obese patients compared to non-obese patients of the same age and with the same severity of injury. The increased risk may be due to challenges related to powering a heavier upper extremity. A weight reduction program might be considered as part of the preoperative strategy.
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http://dx.doi.org/10.1186/s12893-020-00737-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160993PMC
April 2020

Phenolic Profiles of Hardy Kiwifruits and Their Neuroprotective Effects on PC-12 and SH-SY5Y Cells against Oxidative Stress.

J Microbiol Biotechnol 2020 06;30(6):912-919

Graduate School of Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.

Hardy kiwifruits ( Planch.) have high amounts of antioxidants, including ascorbic acid (vitamin C) and phenolics. The anti-cholinesterase activity and neuroprotective effects of three different cultivars of hardy kiwifruits, cv. Mansu ( × ), cv. Haeyeon (), and cv. Chiak (), on PC-12 and SH-SY5Y cells were evaluated. Extraction of phenolics and vitamin C was carried out using 80% (v/v) aqueous ethanol and metaphosphoric acid assisted with homogenization, respectively. Hardy kiwifruit of cv. Mansu showed higher total phenolic, total flavonoid, and vitamin C contents and antioxidant capacity compared to the other tw°Cultivars of hardy kiwifruits, cv. Haeyeon and cv. Chiak. Analysis of high-performance liquid chromatography results revealed the presence of procyanidin B2, (?)-epicatechin, neochlorogenic acid, cryptochlorogenic acid, rutin, hyperoside, isoquercitrin, and astragalin in hardy kiwifruits. The three cultivars of hardy kiwifruits had a wide range of vitamin C content of 55.2?130.0 mg/100 g fresh weight. All three cultivars of hardy kiwifruits had protective effects on neuronal PC-12 and SHSY5Y cells exposed to hydrogen peroxide by increasing cell viability and reducing intracellular oxidative stress. Furthermore, the hardy kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase. Collectively, these results suggest that hardy kiwifruits rich in antioxidants like phenolics and vitamin C have good potential as functional materials in neuroprotective applications.
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http://dx.doi.org/10.4014/jmb.2001.01047DOI Listing
June 2020

Comparison of Polycyclic Aromatic Hydrocarbons Exposure Across Occupations Using Urinary Metabolite 1-Hydroxypyrene.

Ann Work Expo Health 2020 Apr;64(4):445-454

Department of Environmental Health, Korea National Open University, Jongro-gu, Seoul, Korea.

Objectives: Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogens causing lung and skin cancers in exposed workers. Certain occupations, such as coke production, have been associated with high PAH exposure; however, the number of occupations tested to date remains small. Here, we sought to compare PAH exposure across a wide range of occupations based on levels of 1-hydroxypyrene (1-OHP), the urinary exposure surrogate of PAHs.

Methods: We collected urine 1-OHP data from the Korean National Environmental Health Survey (KoNEHS), a nationwide biomonitoring survey. We developed a linear regression model, controlling for sex, age, smoking, and survey cycle, and obtained resulting residuals. Then, we computed the fraction of exceeding the third quartile (Q3) level of residuals for each occupation, which is employed as a relative exposure indicator across occupations.

Results: A total of 15 125 measurements derived from three cycles of KoNEHS were used for analysis. The overall geometric means (GMs) and geometric standard deviation (GSD) of urine 1-OHP levels were 0.16 µg g-1 creatinine and 3.07, respectively. Among the sub-major occupational groups, 'construction and mining related elementary occupations' showed the highest fraction (0.45) of exceeding the Q3 level of residuals. Among the minor occupational groups, 'deliverers' showed a high fraction (0.42) of exceeding the Q3 level of residuals, which indicates rapidly growing occupations to be addressed.

Conclusions: Our results provide ancillary information regarding PAH exposure across occupations, especially for occupations for which PAH exposure has not been well characterized.
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http://dx.doi.org/10.1093/annweh/wxaa014DOI Listing
April 2020

Long-Term Blackcurrant Supplementation Modified Gut Microbiome Profiles in Mice in an Age-Dependent Manner: An Exploratory Study.

Nutrients 2020 Jan 21;12(2). Epub 2020 Jan 21.

Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.

Recent studies have suggested that blackcurrant (BC) anthocyanins have promising health benefits, possibly through regulating gut microbiome. Three- and eighteen-month old female mice were fed standard mouse diets for 4 months, each with or without BC (1% ) supplementation ( = 3 in each treatment group, 12 in total). We then assessed gut microbiome profiles using 16S sequencing of their feces. Old mice had a less diverse microbiome community compared to young mice and there was a remarkable age-related difference in microbiome composition in the beta diversity analysis. BC supplementation did not significantly affect alpha or beta diversity. The relative abundance of several phyla, including Firmicutes, Bacteroidetes, Proteobacteria and Tenericutes, was lower in old mice. BC downregulated Firmicutes abundance in young mice and upregulated Bacteroidetes in both age groups, leading to a decreased Firmicutes/Bacteroidetes ratio. There were age-specific differences in the effect of BC supplementation on the microbiome. Twenty-four operational taxonomic units showed a significant interaction between age and BC supplementation ( < 0.01), which suggests that the ecosystem and the host health status affect the functions and efficiency of BC intake. These results indicate that BC supplementation favorably modulates gut microbiome, but there are distinct age-specific differences. Studies with human hosts are needed to better understand BC's regulatory effects on the gut microbiome.
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http://dx.doi.org/10.3390/nu12020290DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7070352PMC
January 2020

Meroterpenoid-Rich Fraction of the Ethanol Extract of Sargassum Serratifolium Suppresses Collagen-Induced Rheumatoid Arthritis in DBA/1J Mice Via Inhibition of Nuclear Factor κB Activation.

Mol Nutr Food Res 2020 02 10;64(3):e1900373. Epub 2020 Jan 10.

Department of Food Science and Nutrition, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, Republic of Korea.

Scope: Rheumatoid arthritis (RA) is an autoimmune disorder related to the inflammation of cartilage due to the infiltration of inflammatory cells. Sargassum serratifolium, a brown alga, possesses strong anti-inflammatory activities.

Methods And Results: The effect of meroterpenoid-rich fraction from the ethanol extract of S. serratifolium (MES) on RA and its underlying mechanisms on the inhibition of RA using a collagen-induced arthritis (CIA) mouse model are examined. The results show that MES ameliorates paw swelling and reduces the arthritis score. MES considerably decreases the secretion of pro-inflammatory cytokines in the serum and joint tissue of mice. Histopathological analysis demonstrates that MES strongly inhibited bone damage and inflammatory cell intrusion in the joint tissue. The expression of inflammatory enzymes and adhesion molecules is significantly inhibited in the serum and joint tissue of MES-fed mice. In addition, MES downregulates the nuclear factor κB (NF-κB) signaling pathway by suppressing the phosphorylation of protein kinase B, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinases.

Conclusions: MES supplementation remarkably reduces inflammatory response in CIA mouse model. These results indicate that MES can be used as a pharmaceutical agent against RA.
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http://dx.doi.org/10.1002/mnfr.201900373DOI Listing
February 2020

A case of acute organic solvent poisoning during epoxy coating.

Ann Occup Environ Med 2019 18;31:e9. Epub 2019 Jun 18.

Occupational Safety & Health Research Institute, Ulsan, Korea.

Background: In the construction industry, maintaining health and safety of workers often challenging. Among the workers at construction sites, painters are at particular risk of respiratory diseases and neurotoxicity. However, in Korea there is weak enforcement of workers' health and safety practices in the construction industry in Korea. Poisonings frequently occur at (semi)closed construction sites. In this study, we report a case of acute organic solvent poisoning during construction site painting.

Case Presentation: A 71-year-old man was found unconscious at a construction site and immediately transferred to the emergency room. The consciousness level was 'stupor state' and the body temperature was hypothermic, at 32 degrees (Celsius). There were no acute brain or cardiac lesions that would have accounted for the faintness. In addition, blood and urine tests did not indicate a cause of loss of consciousness. He had been painting epoxy to waterproof the basement floor before fainting. According to exposure simulation, the patient was overexposed to various organic solvents, such as approximately 316-624 ppm toluene during the work before fainting. Considering the ventilation status of the workplace and the status of no protection, it is considered that exposure through the respiratory tract was considerable.

Conclusions: The patient in this case lost consciousness during the epoxy coating in a semi-enclosed space. It can be judged as a result of acute poisoning caused by organic solvent exposure and considered to be highly related to work environment.
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http://dx.doi.org/10.35371/aoem.2019.31.e9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751803PMC
June 2019

A case of acute organic solvent poisoning during epoxy coating.

Ann Occup Environ Med 2019 18;31:e9. Epub 2019 Jun 18.

Occupational Safety & Health Research Institute, Ulsan, Korea.

Background: In the construction industry, maintaining health and safety of workers often challenging. Among the workers at construction sites, painters are at particular risk of respiratory diseases and neurotoxicity. However, in Korea there is weak enforcement of workers' health and safety practices in the construction industry in Korea. Poisonings frequently occur at (semi)closed construction sites. In this study, we report a case of acute organic solvent poisoning during construction site painting.

Case Presentation: A 71-year-old man was found unconscious at a construction site and immediately transferred to the emergency room. The consciousness level was 'stupor state' and the body temperature was hypothermic, at 32 degrees (Celsius). There were no acute brain or cardiac lesions that would have accounted for the faintness. In addition, blood and urine tests did not indicate a cause of loss of consciousness. He had been painting epoxy to waterproof the basement floor before fainting. According to exposure simulation, the patient was overexposed to various organic solvents, such as approximately 316-624 ppm toluene during the work before fainting. Considering the ventilation status of the workplace and the status of no protection, it is considered that exposure through the respiratory tract was considerable.

Conclusions: The patient in this case lost consciousness during the epoxy coating in a semi-enclosed space. It can be judged as a result of acute poisoning caused by organic solvent exposure and considered to be highly related to work environment.
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http://dx.doi.org/10.35371/aoem.2019.31.e9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751803PMC
June 2019

Estimates of the Prevalence, Intensity and the Number of Workers Exposed to Cigarette Smoking across Occupations and Industries in Korea.

J Korean Med Sci 2019 Aug 12;34(31):e213. Epub 2019 Aug 12.

Department of Environmental and Health, Korea National Open University, Seoul, Korea.

Background: Tobacco smoking affects the incidence of various illnesses such as lung cancer, respiratory diseases, and cardiovascular diseases. In an effort to prevent smoking-related cancers, we aimed to estimate the smoking prevalence, intensity, and number of workers exposed to smoking, which would be specific to the occupational and industrial circumstances in Korea.

Methods: We used the Korean Working Condition Survey (KWCS) and Korea's Census data. Smoking prevalence and intensity were estimated using the KWCS data. The number of smokers was estimated by multiplying smoking prevalence with the number of workers in the occupation or industry. Smoking prevalence, intensity, and number of smokers were estimated for major, sub-major, and minor groups of occupation and industry.

Results: Of the total labor force in 2010, 52.66% of men and 5.24% of women workers were estimated to be current smokers. Men workers smoked 15.42 cigarettes/day, and women workers 11.29 cigarettes/day. In terms of occupation, "craft and related trades workers" demonstrated the highest smoking prevalence (52.24%). "Managers" smoked the highest number of cigarettes (16.63 cigarettes/day) and "equipment, machine operating, and assembling workers" comprised the largest number of estimated smokers (1,368,726 workers). In terms of industry, "mining and quarrying" had the highest smoking prevalence (69.27%). Those in "construction" smoked the highest number of cigarettes (17.16 cigarettes/day) and those in "manufacturing" comprised the largest number of estimated smokers (1,629,893 workers).

Conclusion: Our results may help in setting priorities for smoking prevention-related activities. In addition, these results can be used for epidemiological studies controlling for the effect of smoking by occupation or industry.
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http://dx.doi.org/10.3346/jkms.2019.34.e213DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6689490PMC
August 2019

Combined flexor carpi ulnaris and flexor carpi radialis transfer for restoring elbow function after brachial plexus injury.

BMJ Case Rep 2019 Jul 17;12(7). Epub 2019 Jul 17.

Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA.

The result of combined agonist and antagonist muscle innervation in traumatic brachial plexus injury through the intraplexal fascicle nerve transfers with the same donor function has not yet been reported. We describe a patient with a C5-C7 traumatic brachial plexus injury who had a combined transfer of the flexor carpi radialis (FCR) fascicle to the musculocutaneous nerve and the flexor carpi ulnaris (FCU) fascicle to the radial nerve of the triceps. The patient returned for his follow-up visit 2 years after his surgery. The muscle strengths of his triceps and biceps were Medical Research Council grade 2 and 0, respectively. Compared with his uninjured side, his grip strength was 9.8%, and his pinch strength was 14.2%. Our case report provides insights on result of combined agonist and antagonist muscle innervation through combining the motor fascicle of the FCR and FCU to restore the elbow flexor and extensor. The result may not be promising.
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http://dx.doi.org/10.1136/bcr-2019-230406DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6663248PMC
July 2019

Maculopathy from an accidental exposure to welding arc.

BMJ Case Rep 2019 Feb 3;12(2). Epub 2019 Feb 3.

Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul, South Korea.

Welding light can cause photic retinal injury. We report binocular maculopathy induced by a brief exposure to electric arc welding light in a patient who could not equipped with protective device because of narrow space. A 47-year-old man performed electric arc welding for approximately 10-15 min without wearing protective device because of narrow space and subsequently experienced eye discomfort and decreased visual acuity. At the initial visit, his best corrected visual acuity was 0.5. Fundus examination, optical coherence tomography (OCT) and multifocal electroretinogram (mfERG) were performed. OCT showed disruption in the ellipsoid zone, and mfERG amplitudes in the central 10° were markedly reduced in both eyes. The decrease in visual acuity had been noted for at least 18 months. Using the proper protective device is essential in welding, despite short time periods of work. For patients with welding-induced photokeratitis, doctors should also consider the possibility of photic retinal injury.
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http://dx.doi.org/10.1136/bcr-2018-227677DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366800PMC
February 2019

Evaluation of antioxidant activities of various solvent extract from Sargassum serratifolium and its major antioxidant components.

Food Chem 2019 Apr 10;278:178-184. Epub 2018 Nov 10.

Department of Food Science and Nutrition, Pukyong National University, Busan 48513, Republic of Korea. Electronic address:

Sargassum serratifolium has been known to contain a high level of meroterpenoids as antioxidant components. We investigated antioxidant activities and active components in various solvent extracts from S. serratifolium. Ethyl acetate, ethanol, and methanol extracts showed relatively strong DPPH, ABTs, and superoxide radical scavenging activities. Hexane and ethyl acetate extract showed the strongest hydroxyl radical and reactive oxygen species (ROS), respectively, scavenging activities. Sargahydroquinoic acid (SHQA), sargachromanol (SCM) and sargaquinoic acid (SQA) were main antioxidant components in S. serratifolium. Ethanol extract showed the highest levels of SHQA, SCM, and SQA which comprised to be 227 ± 6.31 mg/g. SHQA and SCM exhibited stronger antioxidant capacities than SQA based on lower IC values in ROS, DPPH, ABTs, and superoxide radical scavenging assays. The result showed that ethanol is the most efficient extracting solvent for the active components from S. serratifolium and the plant has the potential as a natural antioxidant.
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http://dx.doi.org/10.1016/j.foodchem.2018.11.058DOI Listing
April 2019

Blackcurrant Supplementation Improves Trabecular Bone Mass in Young but Not Aged Mice.

Nutrients 2018 Nov 5;10(11). Epub 2018 Nov 5.

Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.

Due to deleterious side effects of currently available medications, the search for novel, safe, and effective preventive agents for improving bone health in aging continues and is urgently needed. This study aimed to determine whether dietary blackcurrants (BC), an anthocyanin-rich berry, can improve bone mass in a mouse model of age-related bone loss. Thirty-five female C57BL/6J mice, 3 months old ( = 20) and 18 months old ( = 15), were randomized to consume either a standard chow diet or a standard chow diet with 1% (/) BC for four months. Dual-energy X-ray absorptiometry, Micro computed tomography (µCT), and histomorphometric analyses were conducted to assess bone parameters on femurs. Biochemical assays were conducted to determine bone resorption, antioxidant activity, and inflammation in humerus homogenates. Trabecular bone volume (BV/TV) was significantly lower in aged mice compared to young mice (young control, 3.7 ± 0.4% vs aged control, 1.5 ± 0.5%, mean ± SEM (standard error of mean), < 0.01; young BC, 5.3 ± 0.6% vs aged BC, 1.1 ± 0.3%, < 0.001). µCT analysis revealed that BC supplementation increased trabecular BV/TV in young mice by 43.2% ( < 0.05) compared to controls. Histomorphometric analysis revealed a 50% increase, though this effect was not statistically significant ( = 0.07). The osteoblast surface increased by 82.5% in aged mice with BC compared to controls ( < 0.01). In humerus homogenates of young mice, BC consumption reduced C-telopeptide of type I collagen by 12.4% ( < 0.05) and increased glutathione peroxidase by 96.4% ( < 0.05). In humerus homogenates of aged mice, BC consumption increased catalase by 12% ( = 0.09). Aged mice had significantly elevated concentrations of tumor necrosis factor α (TNF-α), a pro-inflammatory cytokine contributing to bone resorption, which was reduced by 43.3% with BC consumption ( = 0.06). These results suggest that early consumption of BC may protect from aging-associated bone loss.
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http://dx.doi.org/10.3390/nu10111671DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266496PMC
November 2018

Correction: A three-dimensional metal grid mesh as a practical alternative to ITO.

Nanoscale 2018 09;10(36):17410

Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea.

Correction for 'A three-dimensional metal grid mesh as a practical alternative to ITO' by Sungwoo Jang et al., Nanoscale, 2016, 8, 14257-14263.
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http://dx.doi.org/10.1039/c8nr90191kDOI Listing
September 2018

Flavonoids, Potential Bioactive Compounds, and Non-Shivering Thermogenesis.

Nutrients 2018 Aug 25;10(9). Epub 2018 Aug 25.

Food and Nutritional Sciences, Department of Family and Consumer Sciences, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA.

Obesity results from the body having either high energy intake or low energy expenditure. Based on this energy equation, scientists have focused on increasing energy expenditure to prevent abnormal fat accumulation. Activating the human thermogenic system that regulates body temperature, particularly non-shivering thermogenesis in either brown or white adipose tissue, has been suggested as a promising solution to increase energy expenditure. Together with the increasing interest in understanding the mechanism by which plant-derived dietary compounds prevent obesity, flavonoids were recently shown to have the potential to regulate non-shivering thermogenesis. In this article, we review the latest research on flavonoid derivatives that increase energy expenditure through non-shivering thermogenesis.
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http://dx.doi.org/10.3390/nu10091168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164844PMC
August 2018

Decision Aid for Trapeziometacarpal Arthritis: A Randomized Controlled Trial.

J Hand Surg Am 2019 Mar 18;44(3):247.e1-247.e9. Epub 2018 Jul 18.

Department of Orthopaedic Surgery, Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA. Electronic address:

Purpose: Decision aids increase patient participation in decision making and reduce decision conflict. The goal of this study was to evaluate the effect of a decision aid prior to the appointment, upon decisional conflict measured immediately after the visit relative to usual care. We also evaluated other effects of the decision aid over time.

Methods: In this randomized controlled trial, we included 90 patients seeking the care of a hand surgeon for trapeziometacarpal (TMC) arthritis for the first time. Patients were randomly assigned to receive either usual care (an informational brochure) or an interactive Web-based decision aid. At enrollment, consult duration was recorded, and patients completed the following measures: (1) Decisional Conflict Scale; (2) Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH); (3) pain intensity; (4) Physical Health Questionnaire (PHQ-2); (5) satisfaction with the visit; and (6) Consultation And Relational Empathy (CARE) scale. At 6 weeks and 6 months, patients completed: (1) pain intensity measure; (2) Decision Regret Scale; and (3) satisfaction with treatment. We also recorded changes in treatment and provider.

Results: Patients who reviewed the interactive decision aid prior to visiting their hand surgeon had less decisional conflict at the end of the visit. Other outcomes were not affected.

Conclusions: Use of a decision aid prior to a first-time visit for TMC led to a measurable reduction in decision conflict. Decision aids make people seeking care for TMC arthritis more comfortable with their decision making. Future research might address the ability of decision aids to reduce surgeon-to-surgeon variation, resource utilization, and dissatisfaction with care CLINICAL RELEVANCE: Surgeons should consider the routine use of decision aids to reduce decision conflict.
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http://dx.doi.org/10.1016/j.jhsa.2018.06.004DOI Listing
March 2019

Work-related olfactory disorder: a case series and review.

Ann Occup Environ Med 2018 12;30:18. Epub 2018 Mar 12.

1Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 400, Jongga-ro, Jung-gu, Ulsan, 44429 South Korea.

Background: The olfactory bulb is anatomically exposed and thus can be directly damaged by external stimulation. This can occur as an occupational injury owing to contact with organic solvents or other causes. We present cases of eight patients who sustained occupation-related exposure to potentially toxic substances and later presented with signs and symptoms of anosmia. We examined the occupational and medical characteristics of the patients and evaluated their work-relatedness.

Case Presentation: Case 1: A 50-year-old man performed high-frequency heat treatments for approximately 11 years. He experienced decreased senses for olfaction and taste during the later years culminating in the diagnosis of anosmia after 3 years (high work-relatedness). Case 2: A 54-year-old man whose work involved exposure to various organic solvents, such as spray painting and application of paint and thinners for approximately 4 years, was subsequently diagnosed with anosmia based on rhinorrhea, headache, and loss of olfaction (high work-relatedness). Case 3: A 44-year-old-man who performed spray painting for approximately 17 years developed anosmia (high work-relatedness). Case 4: A 44-year-old man was involved in ship engine cleaning once a month, for approximately 7 h per cleaning session; he was diagnosed with anosmia based on loss of olfaction (low work-relatedness). Case 5: A 41-year-old man worked in ship building block construction for approximately 13 years; anosmia diagnosis was based on loss of olfaction (low work-relatedness). Case 6: A 47-year-old woman performed product inspection and labeling at a plant manufacturing automobile parts; anosmia diagnosis was based on decreased olfaction and taste (low work-relatedness). Case 7: A 50-year-old woman performed epoxy coating in a plant manufacturing automobile parts; anosmia diagnosis was based on diminishing olfaction (low work-relatedness). Case 8: A 57-year-old woman performed cleaning of the area where mobile phone parts were manufactured; anosmia diagnosis was based on diminishing olfaction (low work-relatedness).

Conclusion: The study results confirmed work-relatedness when the subject was young, and the duration of exposure was long without any other cause of anosmia. Regarding compensation for occupational diseases, work-relatedness can be recognized as a relative concept.
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http://dx.doi.org/10.1186/s40557-018-0230-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5848455PMC
March 2018

Does a Brief Mindfulness Exercise Improve Outcomes in Upper Extremity Patients? A Randomized Controlled Trial.

Clin Orthop Relat Res 2018 04;476(4):790-798

R. F. Westenberg, S. Özkan, A. Nazzal, S.-G. Lee, N. C. Chen, Hand and Upper Extremity Service, Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA E. L. Zale, T. J. Heinhuis, A.-M. Vranceanu, Integrated Brain Health Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA E. L. Zale, Department of Psychology, Syracuse University, Syracuse, NY, USA S. Özkan, Department of Trauma Surgery, VU University Medical Center, Amsterdam, The Netherlands.

Background: Mindfulness-based interventions are useful in reducing psychologic distress and pain intensity in patients with chronic pain. However, most mindfulness-based interventions are resource-intensive, lengthy, and not feasible for busy orthopaedic surgical practices.

Questions/purposes: The purpose of this study was to determine if a 60-second personalized mindfulness-based video exercise is (1) associated with improved pain intensity, emotional distress, and state anxiety compared with an attention placebo control (a time-matched educational pamphlet about pain and stress); and (2) feasible and acceptable for patients with upper extremity injury in an orthopaedic practice.

Methods: This was a single-center, single-blind randomized controlled trial of the mindfulness-based video exercise (60 seconds duration, free online) versus an attention placebo control (an educational pamphlet about pain and stress presented to patients to read over 60 seconds). One hundred forty-nine patients presenting for a new or followup appointment at the office of one of two orthopaedic hand and upper extremity outpatient surgical practices at an urban academic hospital were invited to participate between September 2016 and December 2016. Of 149 patients screened, 125 patients were randomized and completed a demographic questionnaire, the Numeric Rating Scale to assess pain intensity, the State Anxiety subscale of the State Trait Anxiety Inventory to assess state anxiety, and Emotion Thermometers to assess anxiety, anger, and depression before and after the interventions. Postintervention, patients also completed the Client Satisfaction Questionnaire Scale-3 to assess the acceptability. A mean score of 21 or higher is considered acceptable. Feasibility was determined based on number of patients approached who refused participation. The intervention was defined as feasible if refusal rate was lower than 25%. Analysis of covariance was used to test comparative improved pain intensity on the NRS, psychologic distress on the Emotion Thermometers, and state anxiety on the State Anxiety Subscale of the State Trait Anxiety Index after controlling for respective baseline scores. A 1-point minimal clinically important difference (MCID) was used on the NRS for pain intensity.

Results: Adjusted for the baseline means, compared with patients who received the attention placebo control, patients who participated in the mindfulness-based video exercise demonstrated improved pain intensity (mindfulness-based video exercise: 3.03 ± 0.12; control: 3.49 ± 0.12; mean difference: 0.46 [0.12-0.80]; p = 0.008); state anxiety (mindfulness-based video exercise: 32.35 ± 0.59; control: 35.29 ± 0.59; mean difference: 2.94 [1.29-4.59]; p = 0.001); anxiety symptoms (mindfulness-based video exercise: 1.49 ± 0.19; control: 2.10 ± 0.19; mean difference: 0.61 [0.08-1.14]; p = 0.024); depression (mindfulness-based video exercise: 1.03 ± 0.10; control: 1.47 ± 0.11; mean difference: 0.44 [0.15-0.73]; p = 0.004); and anger (mindfulness-based video exercise: 0.76 ± 0.12; control: 1.36 ± 0.12; mean difference: 0.60 [0.26-0.94]; p = 0.001). However, the observed differences in pain intensity were below 1 point on the NRS, which is the MCID established in patients with chronic pain. No MCID is available for the other measures. The mindfulness-based video exercise was feasible based on a dropout rate of 0%, and acceptability reached the medium range with similar scores in both groups (mindfulness-based video exercise: 20.70 ± 5.48; control: 20.52 ± 6.42).

Conclusions: A 60-second mindfulness-based video exercise is feasible to implement and acceptable to patients in busy orthopaedic practices. This video exercise is also effective in improving momentary pain, anxiety, depression, and anger in this population, but it is unclear whether these improved pain and distress levels are meaningful to patients who present with low levels of pain and psychologic distress. Future studies should seek to discern whether the improved pain and distress levels we observed are clinically important or whether the intervention delivers larger effects in subgroups of patients experiencing greater pain intensity and if the improved pain and distress levels are durable. Such studies might also assess cost-effectiveness, because this mindfulness-based tool takes little time and few resources to use, and the effects and durability of multiple sessions of a mindfulness-based video exercise.

Level Of Evidence: Level II, therapeutic study.
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http://dx.doi.org/10.1007/s11999.0000000000000086DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6260083PMC
April 2018

The Role of Correction in the Conservative Treatment of Adolescent Idiopathic Scoliosis.

Open Orthop J 2017 29;11:1548-1557. Epub 2017 Dec 29.

Wanchai Chiropractic Clinic, 11/fl China Hong Kong Tower, 8 Hennessy Road, Wanchai, Hong Kong.

Introduction: Physiotherapeutic Scoliosis-Specific Exercises (PSSE) and bracing have been found to be effective in the stabilization of curves in patients with Adolescent Idiopathic Scoliosis (AIS). Yet, the difference among the many PSSEs and braces has not been studied. The present review attempts to investigate the role of curve correction in the outcome of treatment for PSSEs and braces.

Material And Methods: A PubMed manual search has been conducted for studies on the role of correction in the effectiveness of PSSE and bracing. For the PSSEs, the key words used were "adolescent idiopathic scoliosis, correction, physiotherapy, physical therapy, exercise, and rehabilitation." For bracing, the key words used were "adolescent idiopathic scoliosis, correction and brace". Only papers that were published from 2001-2017 were included and reviewed, as there were very few relevant papers dating earlier than 2001.

Results: The search found no studies on the role of correction on the effectiveness of different PSSEs. The effectiveness of different PSSEs might or might not be related to the magnitude of curve correction during the exercises. However, many studies showed a relationship between the magnitude of in-brace correction and the outcome of the brace treatment.

Discussion: The role of correction on the effectiveness of PSSE has not been studied. In-brace correction, however, has been found to be associated with the outcome of brace treatment. An in-brace correction of < 10% was associated with an increased rate of failure of brace treatment, whereas an in-brace correction of >40-50% was associated with an increased rate of brace treatment success (. stabilization or improvement of curves). Thus, in the treatment of AIS, patients should be advised to use highly corrective braces, in conjunction with PSSE since exercises have been found to help stabilize the curves during weaning of the brace. Presently, no specific PSSE can be recommended.

Conclusion: Braces of high in-brace correction should be used in conjunction with PSSEs in the treatment of AIS. No specific PSSE can be recommended as comparison studies of the effectiveness of different PSSEs are not found at the time of this study.
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http://dx.doi.org/10.2174/1874325001711011548DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5759131PMC
December 2017

Exploiting Anti-T-shaped Graphene Architecture to Form Low Tortuosity, Sieve-like Interfaces for High-Performance Anodes for Li-Based Cells.

ACS Cent Sci 2018 Jan 13;4(1):81-88. Epub 2017 Dec 13.

State Key Laboratory of Automotive Simulation and Control, and Department of Materials Science, and International Center of Future Science, and Electron Microscopy Center, Jilin University, Changchun 130012, China.

Graphitic carbon anodes have long been used in Li ion batteries due to their combination of attractive properties, such as low cost, high gravimetric energy density, and good rate capability. However, one significant challenge is controlling, and optimizing, the nature and formation of the solid electrolyte interphase (SEI). Here it is demonstrated that carbon coating via chemical vapor deposition (CVD) facilitates high electrochemical performance of carbon anodes. We examine and characterize the substrate/vertical graphene interface (multilayer graphene nanowalls coated onto carbon paper via plasma enhanced CVD), revealing that these low-tortuosity and high-selection graphene nanowalls act as fast Li ion transport channels. Moreover, we determine that the hitherto neglected parallel layer acts as a protective surface at the interface, enhancing the anode performance. In summary, these findings not only clarify the synergistic role of the parallel functional interface when combined with vertical graphene nanowalls but also have facilitated the development of design principles for future high rate, high performance batteries.
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http://dx.doi.org/10.1021/acscentsci.7b00444DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5785761PMC
January 2018

Estimation of Lead Exposure Prevalence in Korean Population through Combining Multiple Experts' Judgment based on Objective Data Sources.

Ann Work Expo Health 2018 02;62(2):210-220

Department of Environmental Health, Korea National Open University, Seoul, Korea.

Objective: Estimating carcinogen exposure prevalence is important for preventing occupational cancers. To develop the Korean version of CARcinogen EXposure (CAREX), a carcinogen surveillance system used in many countries, we estimated lead exposure prevalence in the Korean working population.

Methods: We used three Korean nationwide data sources to obtain objective database-derived prevalences of lead exposure across industries: airborne lead measurement data from the work environment measurement database (WEMD), blood lead measurement data from the special health examination database (SHED), and lead exposure prevalence computed using data from the work environment condition survey (WECS), which is a nationwide occupational exposure survey. We also asked a panel of 52 experts with ≥20 years of experience in industrial hygiene practice for their judgment about lead exposure prevalence across industries after they reviewed the database-derived prevalences computed from the three exposure databases. We developed and compared various estimation methods for combining the experts' judgments. The 2010 census was used as the reference population to estimate the number of lead-exposed workers in 228 industries by multiplying the exposure prevalence by the number of workers in each industry.

Results: The database-derived prevalences of lead exposure in the 228 industries were calculated using data collected between 2009 and 2011 from the WEMD and SHED and from the 2009 WECS. From the various estimation methods assessed, the median values of experts' responses were selected as our estimates of lead exposure prevalence in each industry. As a result, it was estimated that 129,250 Korean workers were exposed to lead in 2010.

Conclusions: Based on objective databases, we developed a method for estimating exposure prevalence for the CAREX system by combining experts' judgments. This work may offer an unbiased approach to the development process that accounts for the uncertainty in exposure.
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http://dx.doi.org/10.1093/annweh/wxx106DOI Listing
February 2018