214 research outputs found

    Computer-Aided Designing and Manufacturing of Lingual Fixed Orthodontic Appliance Using 2D/3D Registration Software and Rapid Prototyping

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    The availability of 3D dental model scanning technology, combined with the ability to register CBCT data with digital models, has enabled the fabrication of orthognathic surgical CAD/CAM designed splints, customized brackets, and indirect bonding systems. In this study, custom lingual orthodontic appliances were virtually designed by merging 3D model images with lateral and posterior-anterior cephalograms. By exporting design information to 3D CAD software, we have produced a stereolithographic prototype and converted it into a cobalt-chrome alloy appliance as a way of combining traditional prosthetic investment and cast techniques. While the bonding procedure of the appliance could be reinforced, CAD technology simplified the fabrication process by eliminating the soldering phase. This report describes CAD/CAM fabrication of the complex anteroposterior lingual bonded retraction appliance for intrusive retraction of the maxillary anterior dentition. Furthermore, the CAD/CAM method eliminates the extra step of determining the lever arm on the lateral cephalograms and subsequent design modifications on the study model

    Size distributions of atmospheric particulate matter and associated trace metals in the multi-industrial city of Ulsan, Korea

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    Particulate matter (PM) was collected using micro-orifice uniform deposit impactors from a residential (RES) site and an industrial (IND) site in Ulsan, South Korea, in September-October 2014. The PM samples were measured based on their size distributions (11 stages), ranging from 0.06 ??m to over 18.0 ??m. Nine trace metals (As, Se, Cr, V, Cd, Pb, Ba, Sb, and Zn) associated with PM were analyzed. The PM samples exhibited weak bimodal distributions irrespective of sampling sites and events, and the mean concentrations of total PM (TPM) measured at the IND site (56.7 ??g/m3) was higher than that measured at the RES site (38.2 ??g/m3). The IND site also showed higher levels of nine trace metals, reflecting the influence of industrial activities and traffic emissions. At both sites, four trace metals (Ba, Zn, V, and Cr) contributed to over 80% of the total concentrations in TPM. The modality of individual trace metals was not strong except for Zn; however, the nine trace metals in PM2.5 and PM10 accounted for approximately 50% and 90% of the total concentrations in TPM, respectively. This result indicates that the size distributions of PM and trace metals are important to understand how respirable PM affects public health

    Simultaneous fabrication of line and dot dual nanopatterns using miktoarm block copolymer with photocleavable linker

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    Block copolymers with various nanodomains, such as spheres, cylinders, and lamellae, have received attention for their applicability to nanolithography. However, those microdomains are determined by the volume fraction of one block. Meanwhile, nanopatterns with multiple shapes are required for the next-generation nanolithography. Although various methods have been reported to achieve dual nanopatterns, all the methods need sophisticated processes using E-beam. Here, we synthesized a miktoarm block copolymer capable of cleavage of one block by ultraviolet. Original cylindrical nanodomains of synthesized block copolymer were successfully transformed to lamellar nanodomains due to the change of molecular architecture by ultraviolet. We fabricated dual nanopatterns consisting of dots and lines at desired regions on a single substrate. We also prepared dual nanopatterns utilizing another phase transformation from spheres to cylinders in a block copolymer with higher interaction parameter. Since our concept has versatility to any block copolymer, it could be employed as next-generation nanolithography.112Ysciescopu

    Occupational Lymphohematopoietic Cancer in Korea

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    The purpose of this study was to review the existing studies on lymphohematopoietic (LHP) cancer in Korea, estimate the prevalence of workers exposed to carcinogens, and determine the population attributable fraction (PAF) of leukemia. Two case series and 4 case reports were reviewed. Using official statistics, the prevalence of benzene exposure and ionizing radiation exposure was estimated. Based on the prevalence of exposure and the relative risk, The PAF of leukemia was calculated. Between 1996 and 2005, 51 cases of LHP cancer were reported from the compensation system. Greater than 50% of occupational LHP cancer was leukemia, and the most important cause was benzene. In a cohort study, the standardized incidence ratio was 2.71 (95% CI, 0.56-7.91). The prevalence of exposure was 2.5% and 2.2% in 1995 and 2000, respectively. Using the 1995 prevalence, 3.6-4.8% and 0.1% of cases with leukemia were attributable to benzene and ionizing radiation exposure, respectively, which resulted in 39.7-51.4 cases per year. Benzene is the most important cause of occupational leukemia in Korea. Considering the estimated PAF in this study, the annual number of occupational LHP cancer (51 cases during 10-yr period), might be underreported within the compensation system

    The role of adjuvant pelvic radiotherapy in rectal cancer with synchronous liver metastasis: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Synchronous liver metastases are detected in approximately 25% of colorectal cancer patients at diagnosis. The rates of local failure and distant metastasis are substantial in these patients, even after undergoing aggressive treatments including resection of primary and metastatic liver tumors. The purpose of this study was to determine whether adjuvant pelvic radiotherapy is beneficial for pelvic control and overall survival in rectal cancer patients with synchronous liver metastasis after primary tumor resection.</p> <p>Methods</p> <p>Among rectal cancer patients who received total mesorectal excision (TME) between 1997 and 2006 at Yonsei University Health System, eighty-nine patients diagnosed with synchronous liver metastasis were reviewed. Twenty-seven patients received adjuvant pelvic RT (group S + R), and sixty-two patients were managed without RT (group S). Thirty-six patients (58%) in group S and twenty patients (74%) in group S+R received local treatment for liver metastasis. Failure patterns and survival outcomes were analyzed.</p> <p>Results</p> <p>Pelvic failure was observed in twenty-five patients; twenty-one patients in group S (34%), and four patients in group S+R (15%) (<it>p </it>= 0.066). The two-year pelvic failure-free survival rates (PFFS) of group S and group S+R were 64.8% and 80.8% (<it>p </it>= 0.028), respectively, and the two-year overall survival rates (OS) were 49.1% and 70.4% (<it>p </it>= 0.116), respectively. In a subgroup analysis of fifty-six patients who received local treatment for liver metastasis, the two-year PFFS were 64.9% and 82.9% (<it>p </it>= 0.05), respectively; the two-year OS were 74.1% and 80.0% (<it>p </it>= 0.616) in group S (n = 36) and group S+R (n = 20), respectively.</p> <p>Conclusions</p> <p>Adjuvant pelvic RT significantly reduced the pelvic failure rate but its influence on overall survival was unclear. Rectal cancer patients with synchronous liver metastasis may benefit from adjuvant pelvic RT through an increased pelvic control rate and improved quality of life.</p

    The effect of occupational exposure to welding fumes on trachea, bronchus and lung cancer: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

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    Background: The World Health Organization (WHO) and the International Labour Organization (ILO) are the producers of the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury (WHO/ILO Joint Estimates). Welding fumes have been classified as carcinogenic to humans (Group 1) by the WHO International Agency for Research on Cancer (IARC) in IARC Monograph 118; this assessment found sufficient evidence from studies in humans that welding fumes are a cause of lung cancer. In this article, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from trachea, bronchus, and lung cancer attributable to occupational exposure to welding fumes, to inform the development of WHO/ILO Joint Estimates on this burden of disease (if considered feasible). Objectives: We aimed to systematically review and meta-analyse estimates of the effect of any (or high) occupational exposure to welding fumes, compared with no (or low) occupational exposure to welding fumes, on trachea, bronchus, and lung cancer (three outcomes: prevalence, incidence, and mortality). Data sources: We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including Medline, EMBASE, Web of Science, CENTRAL and CISDOC. We also searched grey literature databases, Internet search engines, and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts. Study eligibility and criteria: We included working-age (≥15 years) workers in the formal and informal economy in any Member State of WHO and/or ILO but excluded children (<15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies, and other non-randomized intervention studies with an estimate of the effect of any (or high) occupational exposure to welding fumes, compared with occupational exposure to no (or low) welding fumes, on trachea, bronchus, and lung cancer (prevalence, incidence, and mortality). Study appraisal and synthesis methods: At least two review authors independently screened titles and abstracts against the eligibility criteria at a first review stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. If studies reported odds ratios, these were converted to risk ratios (RRs). We combined all RRs using random-effects meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence, and strength of evidence, using the Navigation Guide tools and approaches adapted to this project. Subgroup (e.g., by WHO region and sex) and sensitivity analyses (e.g., studies judged to be of “high”/“probably high” risk of bias compared with “low”/“probably low” risk of bias) were conducted. Results: Forty-one records from 40 studies (29 case control studies and 11 cohort studies) met the inclusion criteria, comprising over 1,265,512 participants (≥22,761 females) in 21 countries in three WHO regions (Region of the Americas, European Region, and Western Pacific Region). The exposure and outcome were generally assessed by job title or self-report, and medical or administrative records, respectively. Across included studies, risk of bias was overall generally probably low/low, with risk judged high or probably high for several studies in the domains for misclassification bias and confounding.Our search identified no evidence on the outcome of having trachea, bronchus, and lung cancer (prevalence). Compared with no (or low) occupational exposure to welding fumes, any (or high) occupational exposure to welding fumes increased the risk of acquiring trachea, bronchus, and lung cancer (incidence) by an estimated 48 % (RR 1.48, 95 % confidence interval [CI] 1.29–1.70, 23 studies, 57,931 participants, I2 24 %; moderate quality of evidence). Compared with no (or low) occupational exposure to welding fumes, any (or high) occupational exposure to welding fumes increased the risk dying from trachea, bronchus, and lung cancer (mortality) by an estimated 27 % (RR 1.27, 95 % CI 1.04–1.56, 3 studies, 8,686 participants, I2 0 %; low quality of evidence). Our subgroup analyses found no evidence for difference by WHO region and sex. Sensitivity analyses supported the main analyses. Conclusions: Overall, for incidence and mortality of trachea, bronchus, and lung cancer, we judged the existing body of evidence for human data as “sufficient evidence of harmfulness” and “limited evidence of harmfulness”, respectively. Occupational exposure to welding fumes increased the risk of acquiring and dying from trachea, bronchus, and lung cancer. Producing estimates for the burden of trachea, bronchus, and lung cancer attributable to any (or high) occupational exposure to welding fumes appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates. Protocol identifier: https://doi.org/10.1016/j.envint.2020.106089

    Gyejigachulbu-Tang Relieves Oxaliplatin-Induced Neuropathic Cold and Mechanical Hypersensitivity in Rats via the Suppression of Spinal Glial Activation

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    Activation of spinal glial cells plays a crucial role in the pathogenesis of neuropathic pain. An administration of oxaliplatin, an important anticancer drug, often induces acute neuropathic cold hypersensitivity and/or mechanical hypersensitivity in patients. Gyejigachulbu-tang (GBT), a herbal formula comprising Cinnamomi Cortex, Paeoniae Radix, Atractylodis Lanceae Rhizoma, Zizyphi Fructus, Glycyrrhizae Radix, Zingiberis Rhizoma, and Aconiti Tuber, has been used in East Asia to treat various pain symptoms, especially in cold patients. This study investigated whether and how GBT alleviates oxaliplatin-induced cold and mechanical hypersensitivity in rats. The behavioral signs of cold and mechanical hypersensitivity were evaluated by a tail immersion test in cold water (4°C) and a von Frey hair test, respectively. The significant cold and mechanical hypersensitivity were observed 3 days after an oxaliplatin injection (6 mg/kg, i.p.). Daily oral administration of GBT (200, 400, and 600 mg/kg) for 5 days markedly attenuated cold and mechanical hypersensitivity. Immunoreactivities of glial fibrillary acidic protein (GFAP, astrocyte marker) and OX-42 (microglia marker) in the spinal dorsal horn were significantly increased by an oxaliplatin injection, which were restored by GBT administration. These results indicate that GBT relieves oxaliplatin-induced cold and mechanical hypersensitivity in rats possibly through the suppression of spinal glial activation

    Chromoblastomycosis Caused by Fonsecaea pedrosoi

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    We report herein a case of chromoblastomycosis caused by Fonsecaea (F.) pedrosoi in a 39-year-old male, who showed multiple, asymptomatic, scaly erythematous plaques on the left shin for 12 months. Histopathologically, chronic granulomatous inflammation and either sclerotic or muriform cells were observed. The fungal culture produced typical black colonies of F. pedrosoi. The DNA sequence of the internal transcribed spacer (ITS) region of the clinical sample was 100% match to that of F. pedrosoi IFM 47061 (GenBank accession number AB240943). The patient was treated with 200 mg of itraconazole daily, for 3 months. Skin lesions were improved. In Korea, only 9 cases of chromoblastomycosis, including this case, have been reported until now. The etiologic agent was F. pedrosoi in the majority of cases (6/9;67%). The incidence of chromoblastomycosis was slightly higher in female, and the upper limbs were more affected than the lower limbs in patients

    AKT1 Gene Polymorphisms and Obstetric Complications in the Patients with Schizophrenia

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    ObjectiveaaWe performed a genetic association study with schizophrenic patients to investigate whether the V-akt murine thymoma viral oncogene homolog 1 (AKT1) gene plays a role in obstetric complications. MethodsaaOne-hundred-eighty patients with schizophrenia (male, 113; female, 67) were included. All patients fulfilled DSM-IV criteria for schizophrenia. Obstetric complications were measured by the Lewis scale. Prenatal and perinatal information was retrospectively collected from the patients ’ mothers. We selected six single nucleotide polymorphisms (SNPs) for the AKT1 gene: SNP1 (rs3803300), SNP2 (rs1130214), SNP3 (rs3730358), SNP4 (rs 1130233), SNP5 (rs2494732), and SNPA (rs2498804). The genotype data were analyzed for an association with the Lewis total score in terms of allele, genotype, and haplotype distribution. ResultsaaThe mean total Lewis scores were 1.30±1.61 for males and 1.54±1.87 for females. Higher total score tended to be correlated with an earlier age of onset of schizophrenia in females. In the total sample, no SNP was associated with obstetric complications. However, the additional analyses for male and female subgroups found a significant associatio
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