Joon Woo Lee

We report on the observation of terahertz transparency in random arrays of the single rectangular holes and slits with the areal coverage of only 12%. The terahertz transparency occurs at the fundamental shape resonance of the rectangular holes and confirms the theoretical predictions of earlier works of García-Vidal et al. [Phys. Rev. Lett. 95, 103901 (2005)] on single rectangular holes and of Ruan and Qiu [Phys. Rev. Lett. 96, 233901 (2006)] on random arrays of holes.

BACKGROUND: The efficacy of conventional isotretinoin treatment (0·5-1·0 mg kg⁻¹ daily for 16-32 weeks, reaching a cumulative dose of 120 mg kg⁻¹) for acne has been well established. To date, there are many reports regarding the efficacy of low-dose and intermittent isotretinoin treatment in patients with acne. Data comparing these three therapeutic regimens simultaneously, however, are unavailable. OBJECTIVES: To evaluate the clinical efficacy and tolerability of low-dose and intermittent isotr

OBJECTIVE: The objective of this report was to describe the CT features of intraductal intrahepatic cholangiocarcinoma. CONCLUSION: Segmental or lobar dilatation of the intrahepatic bile ducts associated with or without intraductal polypoid mass, amorphous structures, or both with slight hyperattenuation are common CT findings of intraductal intrahepatic cholangiocarcinoma. The size of the intraductal mass determines the visibility on CT.

BALT lymphomas usually appear as airspace consolidation or nodules with air bronchogram or adjacent ground-glass attenuation at CT. These findings are similar to previous descriptions of pseudolymphomas. Multiple bilateral lesions are common in BALT lymphoma. Bubble-like radiolucencies have not been described previously and can be an additional finding of BALT lymphoma.

We conclude that preganglionic TFESI has the better therapeutic effect on radiculopathy caused by nerve root compression at the level of the supra-adjacent disc than does conventional TFESI, and the difference between the two treatments had borderline statistical significance.

Spinal epidural hemangiomas can have various MR imaging features according to their different histopathologic backgrounds. In addition to common features such as solid hypervascularity, lobular contour, and a rim of low T2 signal intensity, T1 hyperintensity or multisegmental involvement may also be a clue in the differential diagnosis of a spinal epidural hemangioma.

Transforaminal epidural steroid is an effective tool for managing sciatica, and an extraepineural injection may be a predictor of a better outcome for sciatica treated using transforaminal epidural steroid.

Using terahertz time-domain spectroscopy, we study transmission in one-dimensional arrays of slits fabricated on metal plates by laser machining. The enhanced peaks of zero-order transmission spectra are attributed to the combined effects of Fabry–Perot and surface plasmon resonances. Angle dependence of transmission spectra shows that the strongly surface plasmon-enhanced peaks appear when the Fabry–Perot-type resonance is located nearby in energy. This means that surface waves traveling in the

We report on a perfect transmission in one-dimensional metallic structure using time-domain terahertz spectroscopy. Fabry-Perot resonance appearing in spectral region below first Rayleigh minimum strongly enhances transmission up to over ninety-nine percent. Theoretical calculations reveal that under the perfect transmission condition, a symmetric eigenmode inside the slits is excited and a funneling of all incident energy onto the slits occurs, resulting in large energy concentration equivalent

Optimal parameters for DTI in the cervical spinal cord included a b-value of 900 seconds/mm, 15 diffusion gradient directions, 5 excitations, and a slice thickness of 4mm.

BACKGROUND: The purpose of this paper is to provide technology trends and information regarding market and prospects in stents used for human blood vessels in Korea and the world.A stent is a medical device in the form of a cylindrical metal net used to normalize flow when blood or other bodily fluids such as biliary fluids are obstructed in blood vessels, gastrointestinal tracts, etc. by inserting the stent into a narrowed or clogged area. Stents are classified into vascular and non-vascular st