• Anxiety and mood
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• v.16 no.2
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• pp.106-112
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• 2020

Objective : Social anxiety disorder (SAD) is characterized by fear of social threat and exhibits limbic hyper-reactivity toward social stimuli such as emotional faces. A previous study identified the uncinate fasciculus (UF) sub-tract as particularly related to facial memory. To explore the white matter tract relating to face-specific brain regions, we investigated the UF sub-tract in SAD. Methods : The diffusion tensor images of 22 patients with SAD and 20 healthy controls were analyzed with tractography. The UF sub-tract was delineated using the regions of interest of face patches in the anterior temporal lobe and the orbitofrontal cortex, and fractional anisotrophy (FA) and total number of streamlines (ST) were analyzed. We examined the group comparison of FA and ST of the UF sub-tract and correlations of FA and ST with the social anxiety symptoms such as the Liebowitz Social Anxiety Scale (LSAS), the Social Interaction Anxiety Scale (SIAS), the Social Phobia Scale (SPS) and the Fear of Negative Evaluation scale (FNE) in SAD. Results : There were no group differences in FA and ST of the UF sub-tract. However, negative correlations were observed between ST of the right UF sub-tract and severity of social anxiety symptoms (LSAS, r_s=-0.480, p=0.024; SIAS, r_s=-0.580, p=0.005; SPS, r_s=-0.590, p=0.004; FNE, r_s=-0.675, p=0.001) in patients with SAD. Conclusion : Although patients with SAD did not show quantitative abnormalities in the UF sub-tact connecting face-specific brain regions, this structure seems to play a role in the symptom severity of SAD.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.47-56
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• 2006

The repeated loading responses of four shear-critical reinforced concrete beams with two different shear span-to-depth ratios, were studied. One series of beams was reinforced using pairs of bundled stirrups with $90^{\circ}$ standard hooks, haying free end extensions of $6d_b$. The companion beams contained shear reinforcement made with larger diameter headed bars anchored with 50mm diameter circular heads. A single headed bar had the same area as a pair of bundled stirrups and hence the two series were comparable. The test results indicate that beams containing headed bar stirrups have a superior performance to companion beams containing bundled standard stirrups with improved ductility, larger energy absorption and enhanced post-peak load carrying capability. Due to splitting of the concrete cover and local crushing, the hooks of the standard stirrups opened resulting in loss of anchorage. In contrast, the headed bar stirrups did not lose their anchorage and hence were able to develop strain hardening and also served to delay buckling of the flexural compression steel. Excellent load-deflection predictions were obtained by reducing the tension stiffening to account for repeated load effects.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.115-123
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• 2012

Purpose : To evaluate white matter abnormalities on diffusion tensor imaging (DTI) in patients with mild Alzheimer disease (AD) and mild cognitive impairment (MCI), using tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM). Materials and Methods: DTI was performed in 21 patients with mild AD, in 13 with MCI and in 16 old healthy subjects. A fractional anisotropy (FA) map was generated for each participant and processed for voxel-based comparisons among the three groups using TBSS. For comparison, DTI data was processed using the VBM method, also. Results: TBSS showed that FA was significantly lower in the AD than in the old healthy group in the bilateral anterior and right posterior corona radiata, the posterior thalamic radiation, the right superior longitudinal fasciculus, the body of the corpus callosum, and the right precuneus gyrus. VBM identified additional areas of reduced FA, including both uncinates, the left parahippocampal white matter, and the right cingulum. There were no significant differences in FA between the AD and MCI groups, or between the MCI and old healthy groups. Conclusion: TBSS showed multifocal abnormalities in white matter integrity in patients with AD compared with old healthy group. VBM could detect more white matter lesions than TBSS, but with increased artifacts.