Comparison of a Free-Field and a Closed-Field Sound Source Identification Paradigms in Assessing Spatial Acuity in Adults With Normal Hearing Sensitivity

Background and Objectives@#Traditional sound field localization setups in a free-field environment closely represent real-world situations. However, they are costly and sophisticated, and it is difficult to replicate similar setups in every clinic. Hence, a cost-effective, portable, and less sophisticated virtual setup will be more feasible for assessing spatial acuity in the clinical setting. The virtual auditory space identification (VASI) test was developed to assess spatial acuity using virtual sources in a closed field. The present study compares the legitimacy of these two methods. @*Subjects and Methods@#Fifty-five individuals with normal hearing (mean age±SD: 21± 3.26 years) underwent spatial acuity assessment using two paradigms: 1) the sound field paradigm (localization test) and 2) the virtual paradigm (VASI test). Location-specific and overall accuracy scores and error rates were calculated using confusion matrices for each participant in both paradigms. @*Results@#The results of Wilcoxon signed-rank tests showed that the locationspecific and overall accuracy scores for both paradigms were not significantly different. Further, both paradigms did not yield significantly different localization error rates like right and left intra-hemifield errors, inter-hemifield errors, and front-back errors. Spearman’s correlation analysis showed that all the measures of the two paradigms had mild to moderate correlation. @*Conclusions@#These results demonstrate that both VASI and the sound field paradigm localization test performed equally well in assessing spatial acuity.

Microwave assisted synthesis of ZnO-PbS heterojuction for degradation of organic pollutants under visible light.

ZnO, PbS and ZnO-PbS heterojunction were prepared by microwave irradiation to improve the organic pollutants degradation under visible light irradiation. Hexagonal (wurtzite) and cubic crystal structure of ZnO and PbS respectively were confirmed by PXRD. Nano-plate, nano-sponge and nano-sponge imprinted over nano-sheet like morphology of ZnO, PbS and ZnO-PbS respectively were revealed through FESEM analysis. HR-TEM analysis provides the formation of heterojunction. XPS analysis shows the presence of the ZnO-PbS heterojunction. UV-Visible spectroscopy confirms the enhanced visible light response of ZnO-PbS heterojunction than the bare ZnO. The PL and EIS results indicate ZnO-PbS heterojunction exhibited lowest recombination of excitons and electron transfer resistance. Synergistic effect of ZnO-PbS heterojunction leads to efficient degradation against organic pollutants than bare ZnO and PbS. Aniline and formaldehyde were successfully degraded around 95% and 79% respectively, under solar light irradiation. As-prepared photocatalysts obeys pseudo first order reaction kinetics. HPLC analysis also confirms the successful mineralization of organic pollutants into water and CO2.

Acute streptococcal myocarditis presenting as acute ST-elevation myocardial infarction.

Acute streptococcal myocarditis is an uncommon diagnosis in the developed world. Its presentation masquerading as acute myocardial infarction is still uncommon. We describe a case of a young male presenting with a recent diagnosis of streptococcal pharyngitis followed by a classical presentation of post streptococcal myocarditis. This is an unusual presentation of acute rheumatic fever (ARF) masquerading as acute myocardial infarction, with a discussion on its diagnosis and management.

Chronic total occlusion angioplasty through supplying collaterals.

Chronic total occlusions are typically difficult to recannalize especially when adverse angiographic morphologies are identified. We describe a case of chronic total occlusion crossing retrograde through the supplying collaterals followed by successful angioplasty and stenting.

A role for CXCL12 (SDF-1alpha) in the pathogenesis of multiple sclerosis: regulation of CXCL12 expression in astrocytes by soluble myelin basic protein.

The pathogenic mechanisms that contribute to multiple sclerosis (MS) include leukocyte chemotaxis into the central nervous system (CNS) and the production of inflammatory mediators, resulting in oligodendrocyte damage, demyelination, and neuronal injury. Thus, factors that regulate leukocyte entry may contribute to early events in MS, as well as to later stages of lesion pathogenesis. CXCL12 (SDF-1alpha), a chemokine essential in CNS development and a chemoattractant for resting and activated T cells, as well as monocytes, is constitutively expressed at low levels in the CNS and has been implicated in T cell and monocyte baseline trafficking. To determine whether CXCL12 is increased in MS, immunohistochemical analyses of lesions of chronic active and chronic silent MS were performed. CXCL12 protein was detected on endothelial cells (EC) in blood vessels within normal human brain sections and on a small number of astrocytes within the brain parenchyma. In active MS lesions, CXCL12 levels were high on astrocytes throughout lesion areas and on some monocytes/macrophages within vessels and perivascular cuffs, with lesser staining on EC. In silent MS lesions, CXCL12 staining was less than that observed in active MS lesions, and also was detected on EC and astrocytes, particularly hypertrophic astrocytes near the lesion edge. Experiments in vitro demonstrated that IL-1beta and myelin basic protein (MBP) induced CXCL12 in astrocytes by signaling pathways involving ERK and PI3-K. Human umbilical vein EC did not produce CXCL12 after treatment with MBP or IL-1beta. However, these EC cultures expressed CXCR4, the receptor for CXCL12, suggesting that this chemokine may activate EC to produce other mediators involved in MS. In agreement, EC treatment with CXCL12 was found to upregulate CCL2 (MCP-1) and CXCL8 (IL-8) by PI3-K and p38-dependent mechanisms. Our findings suggest that increased CXCL12 may initiate and augment the inflammatory response during MS.

The Mayo Clinic Risk Score predicts in-hospital mortality following primary angioplasty.

BACKGROUND: The Mayo Clinic Risk Score (MCRS) is a validated numeric score that predicts outcome following primary percutaneous coronary intervention (PCI). PURPOSE: We evaluated the ability of MCRS to risk stratify patients undergoing primary angioplasty. METHODS: Patients undergoing primary angioplasty within 6 hours of the onset of chest pain in the New York State percutaneous coronary intervention reporting system (n = 3,005) had their MCRS calculated using predictive variables: age, presence of cardiogenic shock, renal failure, class III-IV congestive heart failure, left main coronary disease and multivessel coronary disease. All patients were presumed to have intra-coronary thrombus and undergoing an urgent/emergent procedure. Based on the MCRS, patients were classified into five risk categories: very low-risk (MCRS < 5), low risk (6-8), moderate (9-11), high (12-14) and very high risk (15-25). RESULTS: The mean age of the study population was 62 years, 70% were male; stents were used in 89% and glycoprotein IIb/IIIa antagonists in 72%. The prevalence of cardiogenic shock, multivessel disease and left main disease was higher in patients with MCRS > 12. Overall in-hospital mortality following primary angioplasty was 4.7%; it was 0% in the very low-risk category, 0.9% in the low-risk category, 3.2% in the moderate-risk category, 10.7% in the high-risk category, and 25.1% in the very high-risk category (p < 0.0001). The higher-risk MCRS category predicted increased risk even when 317 (10.5%) patients with cardiogenic shock were excluded from the analysis. The overall c-statistic for the prediction of in-hospital mortality by MCRS was 0.85. CONCLUSION: Increasing MCRS predicts in-hospital mortality following primary angioplasty.