981 research outputs found

    Near-Infrared Spectroscopy of Infrared-Excess Stellar Objects in the Young Supernova Remnant G54.1+0.3

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    We present the results of broadband near-infrared spectroscopic observations of the recently discovered mysterious stellar objects in the young supernova remnant G54.1+0.3. These objects, which show significant mid-infrared-excess emission, are embedded in a diffuse loop structure of ~1' in radius. Their near-infrared spectra reveal characteristics of late O- or early B-type stars with numerous H and He I absorption lines, and we classify their spectral types to be between O9 and B2 based on an empirical relation derived here between the equivalent widths of the H lines and stellar photospheric temperatures. The spectral types, combined with the results of spectral energy distribution fits, constrain the distance to the objects to be 6.0 ± 0.4 kpc. The photometric spectral types of the objects are consistent with those from the spectroscopic analyses, and the extinction distributions indicate a local enhancement of matter in the western part of the loop. If these objects originate via triggered formation by the progenitor star of G54.1+0.3, then their formations likely began during the later evolutionary stages of the progenitor, although a rather earlier formation may still be possible. If the objects and the progenitor belong to the same cluster of stars, then our results constrain the progenitor mass of G54.1+0.3 to be between 18 and ~35 M_☉ and suggest that G54.1+0.3 was either a Type IIP supernova or, with a relatively lower possibility, Type Ib/c from a binary system

    Comparison of air pollution and the prevalence of allergy-related diseases in Incheon and Jeju City

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    PurposeA high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area.MethodsSecond grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of NO2, CO2, O3, particulate matter (PM) PM10/2.5, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined.ResultsThe levels of outdoor CO, PM10, and PM2.5 were significantly higher in Incheon (P<0.01). The levels of indoor CO, CO2, PM10, PM2.5 were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01).ConclusionWe found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed

    A New Theranostic System Based on Gold Nanocages and Phase-Change Materials with Unique Features for Photoacoustic Imaging and Controlled Release

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    This communication reports a new theranostic system with a combination of capabilities to both enhance the contrast of photoacoustic (PA) imaging and control the release of a chemical or biological effector by high-intensity focused ultrasound (HIFU). The fabrication of this system simply involves filling the hollow interiors of gold nanocages with a phase-change material (PCM) such as 1-tetradecanol that has a melting point of 38−39 °C. The PCM can be premixed and thus loaded with a dye, as well as other chemical or biological effectors. When exposed to direct heating or HIFU, the PCM will melt and escape from the interiors of nanocages through small pores on the surface, concurrently releasing the encapsulated molecules into the surrounding medium. We can control the release profile by varying the power of HIFU, the duration of exposure to HIFU, or both

    Cortical Magnetic Resonance Imaging Findings in Patients With Posttraumatic Olfactory Dysfunction: Comparison According to the Interval Between Trauma and Evaluation

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    ObjectivesPatients with smell loss after craniocerebral trauma are known to have some brain abnormalities, but there was no study to analyze the findings according to the time interval between injury and evaluation. We aimed to identify whether the time interval may influence on the findings in the brain.MethodsMedical records of 19 patients with posttraumatic olfactory dysfunction were reviewed. All of them underwent a magnetic resonance imaging and olfactory function tests. The patients were divided into early (n=10) and delayed (n=9) groups according to the time interval.ResultsMagnetic resonance imaging was taken at a mean time of 2.2 and 59.6 months after trauma in the early and delayed groups, respectively. Abnormal findings in the brain were found in 6 and 8 patients in the early and delayed groups, respectively. The olfactory bulb and orbitofrontal cortex were commonly affected olfactory pathways in both groups. In the early group, the abnormalities were brain tissue defect, hemorrhage, and focal edema whereas tissue defect was the only finding in the delayed group. In the early group, 5 of 6 patients with severe olfactory dysfunction showed brain abnormality while 1 of 4 patients with mild dysfunction had abnormality. In the delayed group, all the patients had severe dysfunction and 8 of 9 patients showed brain abnormality.ConclusionMost patients with traumatic olfactory dysfunction had abnormality in the brain, and brain abnormality might be different according to the timing of evaluation. Furthermore, there might be an association between the severity of olfactory dysfunction and radiological abnormalities

    Suggested Indications for Enucleation of Solid Pseudopapillary Neoplasms in Pediatric Patients

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    Background: Solid pseudopapillary neoplasms (SPNs) are rare, low-grade, malignant neoplasms that can occur in pediatric patients. Although complete resection of the tumor is the principle treatment, SPN enucleation (EN) has been reported to be effective in children. This study aimed to examine the feasibility and safety of EN by comparing it with conventional pancreatectomy (CP), and to present the indications for its use in pediatric patients.Methods: We retrospectively reviewed the medical records of 66 patients who underwent surgery for SPN at our institution from October 1992 to April 2018. Surgical methods, postoperative complications, hospital stay, and recurrence were compared.Results: Of the 66 patients, 15 (22.7%) were treated with EN and 51 (77.3%) were treated with CP. The mean duration of EN operation was 262 min (±145 min) and of CP was 345 min (±195 min). There was no statistically significant difference between the two methods (P = 0.13). To objectively compare the mass size between patients, we introduced a tumor size/intraperitoneal width ratio, which also revealed no significant difference between the 2 surgery groups (P = 0.21). The EN group had one case of recurrence at the resection site. The complications observed were fluid collection, splenic infarctions, hematomas, pancreatic fistulas, portal vein thromboses, and chylous drainage, among which pancreatic fistulas were the most frequent followed by moderate-severe fistulas in the EN group (P &lt; 0.001). The mean postoperative fasting time (EN 17.0 ± 8.7 days vs. CP 5.1 ± 3.3 days, P &lt; 0.001) and mean hospital stay (EN 23.4 ± 10.0 days vs. CP 13.2 ± 6.5 days, P = 0.002) showed statistically significant differences.Conclusion: Compared with CP treatment, EN of SPNs in children has the disadvantages of prolonged fasting times and hospital stays to recover from moderate pancreatic fistulas. However, if appropriate indications are applied, EN can be considered a safe and effective surgical procedure for children

    Comprehensive Analysis of Individual Anatomical Structures for Micturition Symptoms and Maximum Flow Rate in Men With Benign Prostatic Hyperplasia/Lower Urinary Tract Symptoms

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    Purpose Individual anatomical structural variations, including intravesical prostatic protrusion (IPP), prostatic urethral angle (PUA), prostatic urethral length, or prostatic apex shape, were correlated with micturition symptoms. We aimed to investigate the effects of these variables on micturition symptoms in men with benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS). Methods This observational study was based on data from 263 men with the first visit to health promotion center and without BPH/LUTS treatment between March 2020 and September 2022. A multivariate analysis was performed to determine the variables affecting total international prostate symptom score, maximum flow rate (Qmax), and voiding efficacy (postvoid residual volume to total bladder volume ratio). Results Of 263 patients, decreasing PUA increases the severity of international prostate symptoms score (mild, 141.9°; moderate, 136.0°; severe, 131.2°; P<0.015). A multivariate analysis reported that the total international prostate symptom score was correlated with age (P=0.002), PUA (P=0.007), and Qmax (P=0.008). Qmax was negatively associated with IPP (P=0.002). In subanalysis for large prostate volume (≥30 mL, n=81), international prostate symptom score was correlated with PUA (P=0.013), Qmax was correlated with prostatic apex shape (P=0.017), and length of proximal prostatic urethra (P=0.007). IPP was not identified as a significant factor. For small prostate volume (<30 mL, n=182), age (P=0.011) and prostate volume (P=0.004) are correlated with increasing Qmax. Conclusions This study presented that individual anatomical structure variations influenced the micturition symptoms according to prostate volume. To identify the major resistant factors in men with BPH/LUTS, further studies are required to investigate which components played a role in major resistant factors for micturition symptoms
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