Unusual changes of disseminated superficial porokeratosis: actinic keratosis and focal acantholytic dyskeratosis

( Wooseok Jeong ),( Woojung Jin ),( Seunghyun Moon ),( Taekgeun Lee ),( Taegwang Kwon ),( Sookkyung Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Porokeratosis is a disorder of epidermal keratinization manifested clinically by a raised border and histologically by a cornoid lamella. Although porokeratosis has been regarded as a benign entity, malignant transformation has been reported to occur in 7.5 to 11 percent of patients with porokeratosis. Focal acantholytic dyskeratosis(FAD) has a distinctive histologic pattern characterized by suprabasal clefts, acantholytic and dyskeratotic cells which have been observed as an incidental finding in a variety of skin lesions. A 69-year-old man who had underlying disseminated superficial porokeratosis(DSP) presented with a 1.5 X 1.5 cm sized irregular shaped red to brown colored plaque with oozing on his left upper arm. Histologic feature revealed cornoid lamella and architectural disarray, atypical keratinocytes with cellular and nuclear polymorphism which was compatible with actinic keratosis. A 60-year-old woman who had underlying DSP presented with a 1.0 X 0.8 cm sized yellow crusted erythematous plaque on her right lower back. Histologic feature revealed cornoid lamella and extensive acantholysis with suprabasal clefting which was compatible with FAD. There have not been any prior reports of FAD associated with porokeratosis. Herein, we report two unusual changes, actinic keratosis and FAD arising from DSP and we suggest careful observation should be warranted for patient with porokeratosis.

A 0.015-mm<tex> $^{\text{2}}$</tex> Inductorless 32-GHz Clock Generator With Wide Frequency-Tuning Range in 28-nm CMOS Technology

Jeong, Gyu-Seob,Kim, Wooseok,Park, Jaejin,Kim, Taeik,Park, Hojin,Jeong, Deog-Kyoon IEEE 2017 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.64 No.6

<P>This brief illustrates the design of an inductorless high-speed clock generator. Compared to inductance-capacitance (LC) oscillators, ring oscillators are used in order to achieve a wide frequency-tuning range with a small chip area. By employing a cascaded phase-locked loop (PLL) architecture, the phase noise of the oscillator can be effectively suppressed. The first PLL is implemented with high-voltage devices under 1.8-V supply to provide a clean reference for the second PLL. The second PLL consists of only low-voltage devices, with a supply voltage of 0.9 V for high-speed operation. Following the second PLL, a clock doubler multiplies the PLL output clock by a factor of 2, which avoids power-consuming high-frequency clock dividers. In order to minimize any mismatch effects, special layout techniques are employed for the second voltage-controlled oscillator and the clock doubler. The prototype chip was fabricated in 28-nm complementary metal oxide semiconductor (CMOS) technology, and it occupies an active area of only 0.015 mm(2). The proposed PLL achieves a maximum output frequency of 32 GHz and consumes a total power of 30 mW, exhibiting a power efficiency of 0.9 mW/GHz.</P>

Ultraflat Au nanoplates as a new building block for molecular electronics

Jeong, Wooseok,Lee, Miyeon,Lee, Hyunsoo,Lee, Hyoban,Kim, Bongsoo,Park, Jeong Young IOP 2016 Nanotechnology Vol.27 No.21

<P>We demonstrate the charge transport properties of a self-assembled organic monolayer on Au nanoplates with conductive probe atomic force microscopy (CP-AFM). Atomically flat Au nanoplates, a few hundred micrometers on each side, that have only (111) surfaces, were synthesized using the chemical vapor transport method; these nanoplates were employed as the substrates for hexadecanethiol (HDT) self-assembled monolayers (SAMs). Atomic-scale high-resolution images show <img ALIGN='MIDDLE' ALT='$(\sqrt{3}\times \sqrt{3}){\rm{R}}30^\circ $' SRC='http://ej.iop.org/images/0957-4484/27/21/215601/nanoaa1ebdieqn1.gif'/> molecular periodicity, indicating a well-ordered structure of the HDT on the Au nanoplates. We observed reduced friction and adhesion forces on the HDT SAMs on Au nanoplates, compared with Si substrates, which is consistent with the lubricating nature of HDT SAMs. The electrical properties, such as <I>I</I>–<I>V</I> characteristics and current as a function of load, were measured using CP-AFM. We obtained a tunneling decay constant (<I>β</I>) of 0.57 Å<SUP>−1</SUP>, including through-bond (<img ALIGN='MIDDLE' ALT='${\beta }_{\mathrm{tb}}$' SRC='http://ej.iop.org/images/0957-4484/27/21/215601/nanoaa1ebdieqn2.gif'/>?=?0.99 Å<SUP>−1</SUP>) and through-space (<img ALIGN='MIDDLE' ALT='${\beta }_{{\rm{ts}}}$' SRC='http://ej.iop.org/images/0957-4484/27/21/215601/nanoaa1ebdieqn3.gif'/>?=?1.36 Å<SUP>−1</SUP>) decay constants for the two-pathway model. This indicates that the charge transport properties of HDT SAMs on Au nanoplates are consistent with those on a Au (111) film, suggesting that SAMs on nanoplates can provide a new building block for molecular electronics.</P>

Modeling adsorption properties of structurally deformed metal–organic frameworks using structure–property map

Jeong, WooSeok,Lim, Dae-Woon,Kim, Sungjune,Harale, Aadesh,Yoon, Minyoung,Suh, Myunghyun Paik,Kim, Jihan National Academy of Sciences 2017 Proceedings of the National Academy of Sciences Vol.114 No.30

<P>Structural deformation and collapse in metal-organic frameworks (MOFs) can lead to loss of long-range order, making it a challenge to model these amorphous materials using conventional computational methods. In this work, we show that a structure-property map consisting of simulated data for crystalline MOFs can be used to indirectly obtain adsorption properties of structurally deformed MOFs. The structure-property map (with dimensions such as Henry coefficient, heat of adsorption, and pore volume) was constructed using a large data set of over 12000 crystalline MOFs from molecular simulations. By mapping the experimental data points of deformed SNU-200, MOF-5, and Ni-MOF-74 onto this structure-property map, we show that the experimentally deformed MOFs share similar adsorption properties with their nearest neighbor crystalline structures. Once the nearest neighbor crystalline MOFs for a deformed MOF are selected from a structure-property map at a specific condition, then the adsorption properties of these MOFs can be successfully transformed onto the degraded MOFs, leading to a new way to obtain properties of materials whose structural information is lost.</P>

P047 Clinical and histopathologic study of morphea and extragenital lichen sclerosus et atrophicus

( Wooseok Jeong ),( Woojung Jin ),( Seunghyun Moon ),( Taekgeun Lee ),( Taegwang Kwon ),( Sookkyung Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.2

<div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div> Background: Differential diagnosis of morphea and extragenital lichen sclerosus et atrophicus(LSA) is occasionally difficult. There have been very few cases reported describing coexistence of morphea and LSA. Objectives: To evaluate the clinical and histopathologic characteristics that differentiate morphea and extragenital LSA. Methods: We have reviewed the medical records, clinical and dermoscopic photographs, and histopathologic slides of 23 patients of morphea and 4 patients of extragenital LSA diagnosed at our clinic between 2006 and 2016. Results: Dermoscopic feature of comedo-like openings was significantly increased in the patients with extragenital LSA compared with morphea. Histopathologic features of hyperkeratosis, epidermal atrophy and homogenized collagen in the upper dermis were significantly increased in the patients with extragenital LSA compared with morphea. There were no statistically significant differences according to the clinical features and autoimmune antibody studies. 2 patients showed overlapping features of both morphea and LSA in the same lesion. Conclusion: Dermoscopy can be useful and there are distinctive histopathologic findings to differentiate the two diseases. Although their typical forms are distint, overlapping features of two lesions appear to represent different presentations along the same disease spectrum. Further studies on a larger group would be needed to confirm and clarify such findings.

[P059] A case of multicentric reticulohistiocytosis misdiagnosed as rheumatoid arthritis

( Wooseok Jeong ),( Woojung Jin ),( Seunghyun Moon ),( Hyun Hwangbo ),( Sookkyung Lee ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.1

Multicentric reticulohistiocytosis(MRH) is a rare disease of unknown etiology that is characterized by skin and mucosal nodular eruptions and arthritis. MRH can result in severe disfigurement of skin and rapidly destructive, irreversible deforming arthritis. A quarter of patients with MRH have associated with internal malignancy. It is easily possible to confuse MRH with other more common autoimmune inflammatory conditions like rheumatoid arthritis. We report here a case of MRH misdiagnosed as rheumatoid arthritis. A 69-year-old woman presented with multiple joint pain that had lasted for 2 years and skin nodules present for 4 months. She had been diagnosed with rheumatoid arthritis and was being treated at another hospital. She had tender reddish-brown papulonodules on the elbows, hands, ears, and nose. Histopathological findings showed large mononucleated cells with finely granular ground glass appearing cytoplasm. The multinucleated giant cells were large and irregular, with many haphazardly arranged nuclei. In order to screen for associated malignancies or autoimmune diseases, we performed mammography, gastro-colonoscopy, abdomen computed tomography(CT), and autoimmune antibody tests. The test results were within normal ranges. Prompt and accurate diagnosis of MRH is important to prevent irreversible disabilities and negative prognosis due to missing associated malignancies or autoimmune diseases.

Contact Force Control with Feedback Linearization in Hydraulic Actuator

Wooseok Jeong,Chanyong Park,Sangchul Han,Hyungpil Moon 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5

Understanding the Mechanisms of CO₂ Adsorption Enhancement in Pure Silica Zeolites under Humid Conditions

Jeong, WooSeok,Kim, Jihan American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.41

<P>Using grand canonical Monte Carlo simulations, computational screening of hundreds of pure silica zeolites were conducted to identify materials that show enhanced CO2 uptake under humid conditions. Herein, we show that CO, adsorption performance can be either enhanced or degraded depending on the CO2/H2O binding site separations and characteristics of CO2/H2O interaction energies. As expected, CO2 adsorption capacity is significantly degraded when its binding sites overlap with the H2O sites. On the other hand, CO2 adsorption performance is enhanced when CO2/H2O binding sites are clearly separated as shown from the molecular simulations. However, we show that there are zeolite structures where CO2 enhancement is observed despite the close distance between the CO2 and H2O binding sites. It is demonstrated that favorable long-range Coulomb interaction between CO2 and H2O molecules is responsible for enhanced CO2 adsorption performance in these materials.</P>

A study of clinical and histopathological implications between circumscribed palmar hypokeratosis and other solitary skin lesions on the palm

( Wooseok Jeong ),( Woojung Jin ),( Seunghyun Moon ),( Hyun Hwangbo ),( Sookkyung Lee ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Circumscribed palmar hypokeratosis(CPH) is characterized by an erythematous sharply circumscribed and depressed macule mostly on the thenar or hypothenar eminence of the palm. It has shown a benign behavior, but recently a case of its association with actinic keratosis has been reported. The pathogenesis of this entity still remains unclear. Objectives: To investigate the clinical and histopathological implications between CPH and other solitary skin lesions on the palm. Methods: We have reviewed the medical records and histopathologic slides of 55 patients who underwent histopathologic examination for the solitary skin lesion on the palm at our clinic between 1995 and 2017. Results: Common solitary skin diseases on the palm were pyogenic granuloma (n=8), dermatofibroma (n=6), CPH (n=5), bowen's disease (n=5) and verruca (n=5). The epidermal lesions that affected thenar or hypothenar area included CPH (n=5), bowen's disease (n=3), verruca (n=3) and squamous cell carcinoma (SCC, n=1). Mean age of CPH patients was 62.8 years, bowen's disease was 53.8, verruca was 25.0, and SCC was 81.0. One patient with CPH showed bowenoid epidermal change due to human papilloma virus infection. Conclusion: Our study suggests that CPH has some similar features and is associated with other epidermal lesions on the palm such as bowen's disease, verruca and SCC. Further studies with a larger group would be needed to confirm and clarify such findings.

Improvement of facial asymmetry using high intensity focused ultrasound (HIFU) in a Ramsay Hunt syndrome patient

( Wooseok Jeong ),( Woojung Jin ),( Seunghyun Moon ),( Taekgeun Lee ),( Jongkeun Seo ),( Taegwang Kwon ),( Sookkyung Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Ramsay Hunt syndrome (herpes zoster oticus) is characterized by vesicles on the pinna, otalgia, facial nerve palsy and hearing loss. The most common clinical appearance was vesicular eruptions and facial nerve palsy including change in nasolabial fold and location of the lip. Although early systemic steroid is administered, facial nerve palsy persists in more than 50% of the patients. High intensity focused ultrasound (HIFU) has become one of the most popular non-invasive technologies for skin tightening and face lifting. HIFU is a highly precise medical procedure that delivers high-intensity focused ultrasound to the deeper layers of the skin. A 42-year-old man who had been diagnosed as Ramsay Hunt syndrome 4 years ago presented with facial asymmetry due to left facial palsy. Left eyebrow, left eyelid and left angle of mouth were sagging down. 2 months after a single session of HIFU treatment, left eyebrow and left angle of mouth were lifting. The patient was satisfied with improvement of facial asymmetry. We report the application of HIFU as a treatment tool to the face in a patient with facial asymmetry due to left facial palsy by Ramsay Hunt syndrome.