3,144 research outputs found
Chronic rhinosinusitis with nasal polyps in older adults : clinical presentation, pathophysiology, and comorbidity
Purpose of Review Chronic rhinosinusitis and nasal polyps (CRSwNP) is a common condition that significantly affects patients' life. This work aims to provide an up-to-date overview of CRSwNP in older adults, focusing on its aging-related clinical presentations, pathophysiology, and comorbidity associations including asthma. Recent Findings Recent large population-based studies using nasal endoscopy have shown that CRSwNP is a mostly late-onset disease. Age-related changes in physiologic functions, including nasal epithelial barrier dysfunction, may underlie the incidence and different clinical presentations of CRSwNP in older adults. However, there is still a paucity of evidence on the effect of aging on phenotypes and endotypes of CRSwNP. Meanwhile, late-onset asthma is a major comorbid condition in patients with CRSwNP; they frequently present with type 2 inflammatory signatures that are refractory to conventional treatments when they are comorbid. However, as they are more commonly non-atopic, causative factors other than classical atopic sensitization, such as Staphylococcus aureus specific IgE sensitization, are suggested to drive the type 2 inflammation. There are additional comorbidity associations in older patients with CRSwNP, including those with chronic otitis media and head and neck malignancy. Age is a major determinant for the incidence and clinical presentations of CRSwNP. Given the heterogeneity in phenotypes and endotypes, longitudinal investigations are warranted to elucidate the effects of aging on CRSwNP
Bis[(2,2-dimethylpropanoyloxy)methyl] {[2-(6-amino-9H-purin-9-yl)ethoxy]methyl}phosphonate–succinic acid (2/1)
The title compound, C20H32N5O8P·0.5C4H6O4, is composed of two 9-{2-[bis(pivaloyloxymethoxy)phosphinylmethoxy]ethyl}adenine, commonly known as adefovir dipivoxil (AD), molecules linked to the carboxylic acid groups of succinic acid (SA). The asymmetric unit contains one molecule of AD and half a molecule of SA, which sits on an inversion center. Both adenine units in the two AD molecules make AD–SA N—H⋯O and SA–AD O—H⋯N hydrogen bonds to SA. In addition, the intermolecular AD–AD N—H⋯O—P hydrogen bond serves to stabilize the cocrystal. There is also a π–π stacking interaction [interplanar spacing 3.34 (19) Å] between adjacent inversion-related adenine groups
The Use of Pluripotent Stem Cell for Personalized Cell Therapies against Neurological Disorders
Although there are a number of weaknesses for clinical use, pluripotent stem cells are valuable sources for patient-specific cell therapies against various diseases. Backed-up by a huge number of basic researches, neuronal differentiation mechanism is well established and pluripotent stem cell therapies against neurological disorders are getting closer to clinical application. However, there are increasing needs for standardization of the sourcing pluripotent stem cells by establishing stem cell registries and banking. Global harmonization will accelerate practical use of personalized therapies using pluripotent stem cells
The Effects of Furosemide and Hypoxia on CIick-Evoked Otoacoustic Emissions in Anesthetized Guinea Pigs
From the concepts of well known ototoxic effects of loop diuretics
and hypoxic state, twenty anesthetized guinea pigs with diuretics and/or hypoxia
were evaluated with click-evoked otoacoustic emissions (CEOAEs) by timesequential
monitoring. Furosemide 25 mg/kg was infused intravenously and
CEOAEs were measured before and 5, 10, 20, 30, 45 and 60 minutes after
injection in 8 guinea pigs. Both echo responses and reproducibilities were
decreased significantly at 10 minutes after injection and showed minimal level at
20 minutes. Recovery of CEOAEs was noted by spectral analysis at 30 minutes
after injection, and full recovery of CEOAEs was evident after then. At 60
minutes after injection, hypoxia of 20 seconds by turning off the artificial
respirator was added. The CEOAEs showed statistically significant decreases
compared with those of prehypoxic state (p<O.OI). The CEOAEs of 8 guinea pigs
with injection of furosemide. 50 mg/kg showed decreased responses and no
fr
recoveries for the 60 minutes observation periods. Findings from this study
support the clinical utility of CEOAEs as a screening test for early detection of
various ototoxicities
High Performance n-Channel Organic Field-Effect Transistor of Conjugated Polymers with Fluorine-Substituted Phenylene Unit
OAIID:oai:osos.snu.ac.kr:snu2013-01/104/0000001236/9SEQ:9PERF_CD:SNU2013-01EVAL_ITEM_CD:104USER_ID:0000001236ADJUST_YN:NEMP_ID:A004558DEPT_CD:445CITE_RATE:0FILENAME:20130328_한국영국교류_(120x90)_정의혁.pdfDEPT_NM:재료공학부EMAIL:[email protected]:
Comparison of Internal and Total Optical Aberrations for 2 Aberrometers: iTrace and OPD Scan
PURPOSE: To compare and evaluate the total and internal aberrations measured by two aberrometers: the laser ray tracing aberrometer (iTrace, Tracey Technology) and the automatic retinoscope aberrometer (OPD Scan, Nidek).
METHODS: A total of 54 healthy eyes were enrolled in the study. Following pupil dilation, aberrations were measured with the iTrace and OPD Scan. We compared the aberrations obtained from measurements obtained at pupillary diameters of 4 mm and 6 mm with the OPD Scan and iTrace. Aberrations of internal optics and total aberrations were compared for the two aberrometers. For each aberrometer and each eye, the averaged Zernike data were used to calculate various root-mean-square (RMS) data. These parameters, together with the refractive parameters, were then analyzed and complimented by paired t-tests.
RESULTS: At a pupil diameter of 4 mm, the number of total aberrations in the entire eye showed significant differences for the mean values of spherical aberrations (Z4,0) obtained with the OPD Scan and iTrace aberrometers (p=0.001). Aberrations of the internal optics showed significant differences in the mean values of total RMS, coma (Z3,-1), and trefoil (Z3,3) between the iTrace and OPD Scan (p<0.001, p=0.01, p<0.001) for the same pupil diameter of 4 mm. At a pupil diameter of 6 mm, the two instruments showed a similar number of total aberrations. Aberrations of the internal optics showed significant differences in the mean values of total RMS, spherical aberration (Z4,0), and coma (Z3,-1) between the two devices (p<0.001, p=0.01, p<0.001).
CONCLUSIONS: The iTrace and OPD Scan showed the largest number of differences for aberrations of internal optics rather than total aberrations for both pupil diameters. These results suggest that in healthy eyes, the two aberrometers may vary in some details. The aberrometers showed more agreement at a pupil diameter of 6 mm compared to 4 mmope
Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases
We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis
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