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20. The U-shaped association between achieved blood pressure and risk of cardiovascular events and mortality in elderly and younger patients

Author

Lim, N, Park, H, Kim, W, Mancia, G, Cho, M, Lim N. -K., Park H. -Y., Kim W. -H., Mancia G., Cho M. -C., Lim, N, Park, H, Kim, W, Mancia, G, Cho, M, Lim N. -K., Park H. -Y., Kim W. -H., Mancia G., and Cho M. -C.

Abstract

Objective:The main objective is to assess the appropriate level of achieved SBP and DBP to prevent cardiovascular events.Methods:We used the National Sample Cohort from the National Health Insurance Service in Korea and analyzed data of 44462 hypertensive patients aged 20 - 84 years. Achieved SBP and DBP were categorized according to average achieved SBP (<120, 120-129, 130-139, 140-149, and ≥150mmHg) and DBP (<70, 70-79, 80-89, 90-99, and ≥100mmHg). We examined the association between achieved BP and composite outcome including cardiovascular death, admission of stroke, myocardial infarction, or heart failure, and all-caused death in elderly aged more than 65 years and in younger patients.Results:After a median follow-up of 6.8 years, achieved SBP less than 120mmHg and at least 150mmHg in elderly and younger patients, respectively, were significantly associated with a higher risk of composite outcome than achieved SBP of 120-129mmHg. Cox's proportional hazard analysis showed that the association between achieved SBP and risk of composite outcome and all-cause death had U-shaped relationships and identified a nadir of SBP of 135.6 and 128.9mmHg, respectively, for composite outcome and 135.1 and 131.4mmHg, respectively, for all-cause death in elderly and younger patients.Conclusion:Compared with SBP of 120-129mmHg, not only low achieved SBP of less than 120mmHg but also high BP are associated with risk of adverse cardiovascular event and all-cause death in both elderly and younger patients with a distinct U-shaped relationship.

Published
2020

21. Characterization of Mid-Infrared Single Mode Fibers as Modal Filters

Author

Ksendzov, A, Lay, O, Martin, S, Sanghera, J. S, Busse, L. E, Kim, W. H, Pureza, P. C, Nguyen, V. Q, and Aggarwal, I. D

Subjects
Optics
Abstract

We present a technique for measuring the modal filtering ability of single mode fibers. The ideal modal filter rejects all input field components that have no overlap with the fundamental mode of the filter and does not attenuate the fundamental mode. We define the quality of a nonideal modal filter Q(sub f) as the ratio of transmittance for the fundamental mode to the transmittance for an input field that has no overlap with the fundamental mode. We demonstrate the technique on a 20 cm long mid-infrared fiber that was produced by the U.S. Naval Research Laboratory. The filter quality Q(sub f) for this fiber at 10.5 micron wavelength is 1000 +/- 300. The absorption and scattering losses in the fundamental mode are approximately 8 dB/m. The total transmittance for the fundamental mode, including Fresnel reflections, is 0.428 +/- 0.002. The application of interest is the search for extrasolar Earthlike planets using nulling interferometry. It requires high rejection ratios to suppress the light of a bright star, so that the faint planet becomes visible. The use of modal filters increases the rejection ratio (or, equivalently, relaxes requirements on the wavefront quality) by reducing the sensitivity to small wavefront errors. We show theoretically that, exclusive of coupling losses, the use of a modal filter leads to the improvement of the rejection ratio in a two-beam interferometer by a factor of Q(sub f).

Published
2007
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29. P2690The bleeding and cardiovascular risk according to NSAIDs selectivity in patients receiving antithrombotics and concomitant NSAIDs after myocardial infarction: a nationwide cohort study

Author

Park, E J, primary, Kim, W H, additional, Choi, J Y, additional, Jang, W Y, additional, Na, J O, additional, Choi, J I, additional, Kim, J W, additional, Kim, E J, additional, Rha, S W, additional, Park, C G, additional, Seo, H S, additional, and Choi, C U, additional

Published
2018
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30. Area-selective atomic layer deposition of metal oxides on noble metals through catalytic oxygen activation

Author

Singh, J. (Joseph), Thissen, N.F.W., Kim, W.-H., Johnson, H., Kessels, W.M.M., Bol, A.A., Bent, S.F., Mackus, A.J.M., Singh, J. (Joseph), Thissen, N.F.W., Kim, W.-H., Johnson, H., Kessels, W.M.M., Bol, A.A., Bent, S.F., and Mackus, A.J.M.

Abstract

Area-selective atomic layer deposition (ALD) is envisioned to play a key role in next-generation semiconductor processing and can also provide new opportunities in the field of catalysis. In this work, we developed an approach for the area-selective deposition of metal oxides on noble metals. Using O2 gas as co-reactant, area-selective ALD has been achieved by relying on the catalytic dissociation of the oxygen molecules on the noble metal surface, while no deposition takes place on inert surfaces that do not dissociate oxygen (i.e., SiO2, Al2O3, Au). The process is demonstrated for selective deposition of iron oxide and nickel oxide on platinum and iridium substrates. Characterization by in situ spectroscopic ellipsometry, transmission electron microscopy, scanning Auger electron spectroscopy, and X-ray photoelectron spectroscopy confirms a very high degree of selectivity, with a constant ALD growth rate on the catalytic metal substrates and no deposition on inert substrates, even after 300 ALD cycles. We demonstrate the area-selective ALD approach on planar and patterned substrates and use it to prepare Pt/Fe2O3 core/shell nanoparticles. Finally, the approach is proposed to be extendable beyond the materials presented here, specifically to other metal oxide ALD processes for which the precursor requires a strong oxidizing agent for growth.

Published
2018

36. Wavelet based multi-scale shape features on arbitrary surfaces for cortical thickness discrimination

Author

Kim, W. H., Pachauri, D., Hatt, C., Moo Chung, Johnson, S. C., and Singh, V.

Subjects
Article
Abstract

Hypothesis testing on signals defined on surfaces (such as the cortical surface) is a fundamental component of a variety of studies in Neuroscience. The goal here is to identify regions that exhibit changes as a function of the clinical condition under study. As the clinical questions of interest move towards identifying very early signs of diseases, the corresponding statistical differences at the group level invariably become weaker and increasingly hard to identify. Indeed, after a multiple comparisons correction is adopted (to account for correlated statistical tests over all surface points), very few regions may survive. In contrast to hypothesis tests on point-wise measurements, in this paper, we make the case for performing statistical analysis on multi-scale shape descriptors that characterize the local topological context of the signal around each surface vertex. Our descriptors are based on recent results from harmonic analysis, that show how wavelet theory extends to non-Euclidean settings (i.e., irregular weighted graphs). We provide strong evidence that these descriptors successfully pick up group-wise differences, where traditional methods either fail or yield unsatisfactory results. Other than this primary application, we show how the framework allows performing cortical surface smoothing in the native space without mappint to a unit sphere.

Published
2012

41. Highly Reliable Flip-Chip-on-Flex Package Using Multilayered Anisotropic Conductive Film.

Author

Myung Jin Yim, W. H., Jin-Sang Hwang, W. H., Jin Gu Kim, W. H., Jin Yong Ahn, W. H., Hyung Joon Kim, W. H., Woonseong Kwon, W. H., and Kyung-Wook Paik

Subjects
ANISOTROPY, LIQUID crystal displays, ADHESION, WETTING, INTEGRATED circuits
Abstract

Anisotropic conductive film (ACF) has been used as interconnect material for flat-panel display module packages, such as liquid crystal displays (LCDs) in the technologies of tape automated bonding (TAB), chip-on-glass (COG), chipon film (COF), and chip-on-board (COB). Among them, COF is a relatively new technology after TAB and COG bonding, and its requirement for ACF becomes more stringent because of the need of high adhesion and fine-pitch interconnection. To meet these demands, strong interfacial adhesion between the ACF, substrate, and chip is a major issue. We have developed a multilayered ACF that has functional layers on both sides of a conventional ACF layer to improve the wetting properties of the resin on two-layer flex for better interface adhesion and to control the flow of conductive particles during thermocompression bonding and the resulting reliability of the interconnection using ACF. To investigate the enhancement of electrical properties and reliability of multilayered ACF in COF assemblies, we evaluated the performance in contact resistance and adhesion strength of a multilayered ACF and single-layered ACF under various environmental tests, such as a thermal cycling test (-55°C/+160°C, 1,000 cycles), a high-temperature humidity test (85°C/85% RH, 1,000 h), and a high-temperature storage test (150°C, 1,000 h). The contact resistance of the multilayered ACF joint was in an acceptable range of around a 10% increase of the initial value during the 85°C/85% RH test compared with the single-layered ACF because of the stronger moisture resistance of the multilayered ACF and flex substrate. The multilayered ACF has better adhesion properties compared with the conventional single-layered ACF during the 85°C/85% RH test because of the enhancement of the wetting to the surface of the polymide (PI) flex substrate with an adhesion-promoting nonconductive film (NCF) layer of multilayered ACF. The new ACF of the multilayered... [ABSTRACT FROM AUTHOR]

Published
2004
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42. Microstructure and Strength of Bump Joints in Photodiode Packages.

Author

Kyung-Seob Kim, W. H., Nam-Kyu Kim, W. H., Chung-Hee Yu, W. H., Joong-Jung Kim, W. H., and Eui-Goo Chang

Subjects
STRENGTH of materials, MECHANICS (Physics), JOINTS (Engineering), INTERMETALLIC compounds, PHOTODIODES, TRANSMISSION electron microscopy
Abstract

The joint strength and fracture surfaces of Sn-Pb and Au stud bumps for photodiode packages after isothermal aging were studied experimentally. Aluminum/gold stud bumps and Cu/Sn-Pb solders were adopted and aged for up to 900 h to analyze the effect of intermetallic compound (IMC) formation. The joint strength decreased with aging time. The diffraction patterns of Cu6Sn5, scallop-shaped IMCs, and planar-shaped Cu3Sn were characterized by transmission electron microscopy (TEM). The IMCs between Au stud bumps and A1 pads was identified as AlAu2. The formation of Kirkendall voids and the growth of IMCs at the solder joint were found to be a possible mechanism for joint strength reduction. [ABSTRACT FROM AUTHOR]

Published
2004
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45. Incidence and clinical features ofClostridium difficileinfection in Korea: a nationwide study

Author

KIM, Y. S., primary, HAN, D. S., additional, KIM, Y. H., additional, KIM, W. H., additional, KIM, J. S., additional, KIM, H. S., additional, PARK, Y. S., additional, SONG, H. J., additional, SHIN, S. J., additional, YANG, S. K., additional, YE, B. D., additional, EUN, C. S., additional, LEE, K. M., additional, LEE, S. H., additional, JANG, B. I., additional, JUNG, S. A., additional, CHEON, J. H., additional, CHOI, C. H., additional, and HUH, K. C., additional

Published
2012
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47. Determinants of Epstein-Barr virus-positive gastric cancer: an international pooled analysis

Author

Camargo, M C, primary, Murphy, G, additional, Koriyama, C, additional, Pfeiffer, R M, additional, Kim, W H, additional, Herrera-Goepfert, R, additional, Corvalan, A H, additional, Carrascal, E, additional, Abdirad, A, additional, Anwar, M, additional, Hao, Z, additional, Kattoor, J, additional, Yoshiwara-Wakabayashi, E, additional, Eizuru, Y, additional, Rabkin, C S, additional, and Akiba, S, additional

Published
2011
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49. Increasing Nodal Ratio is a Poor Prognostic Factor for Survival in Stage III-IV (M0) Gastric Cancer Patients Who Received Curative Surgery Followed by Adjuvant Chemotherapy: A Retrospective Study

Author

Kim, J.-S., primary, Kim, M.-A., additional, Oh, D.-Y., additional, Lee, S.-H., additional, Kim, D.-W., additional, Im, S.-A., additional, Kim, W. H., additional, Yang, H.-K., additional, Heo, D. S., additional, Bang, Y.-J., additional, Lee, K.-U., additional, and Kim, T.-Y., additional

Published
2010
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