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1.
Front Genet ; 15: 1364993, 2024.
Article in English | MEDLINE | ID: mdl-38606355

ABSTRACT

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide, caused by a complex interplay of genetic and environmental factors. This study aimed to evaluate the combined efficacy of multi-polygenic risk scores and pooled cohort equations (PCE) for predicting future CVD risks in the Korean population. In this longitudinal study, 7,612 individuals from the Ansan and Ansung cohorts were analyzed over a 17-year follow-up period. The participants were genotyped using the Korea Biobank Array, and quality-controlled genetic data were subjected to imputation analysis. The weighted sum of the PRSs (wPRSsum) was calculated using PRS-CS with summary statistics from myocardial infarction, ischemic stroke, coronary artery disease, and hypertension genome-wide association studies. The recalibrated PCE was used to assess clinical risk, and the participants were stratified into risk groups based on the wPRSsum and PCE. Associations between these risk scores and incident CVD were evaluated using Cox proportional hazards models and Kaplan-Meier analysis. The wPRSsum approach showed a significant association with incident CVD (HR = 1.15, p = 7.49 × 10-5), and the top 20% high-risk genetic group had an HR of 1.50 (p = 5.04 × 10-4). The recalibrated PCE effectively differentiated between the low and high 10-year CVD risk groups, with a marked difference in survival rates. The predictive models constructed using the wPRSsum and PCE demonstrated a slight improvement in prediction accuracy, particularly among males aged <55 years (C-index = 0.640). We demonstrated that while the integration of wPRSsum with PCE did not significantly outperform the PCE-only model (C-index: 0.703 for combined and 0.704 for PCE-only), it provided enhanced stratification of CVD risk. The highest risk group, identified through the combination of high wPRSsum and PCE scores, exhibited an HR of 4.99 for incident CVD (p = 1.45 × 10-15). These findings highlight the potential of integrating genetic risk assessments with traditional clinical tools for effective CVD risk stratification. Although the addition of wPRSsum to the PCE provided a marginal predictive improvement, it proved valuable in identifying high-risk individuals and supporting personalized treatment strategies. This study reinforces the utility of multi-PRS in conjunction with clinical risk assessment tools, paving the way for more tailored approaches for CVD prevention and management in diverse populations.

2.
Heliyon ; 10(1): e23597, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38187293

ABSTRACT

Early detection of atrial fibrillation (AF) is crucial for its effective management and prevention. Various methods for detecting AF using deep learning (DL) based on supervised learning with a large labeled dataset have a remarkable performance. However, supervised learning has several problems, as it is time-consuming for labeling and has a data dependency problem. Moreover, most of the DL methods do not provide any clinical evidence to physicians regarding the analysis of electrocardiography (ECG) for classification or detection of AF. To address these limitations, in this study, we proposed a novel AF diagnosis system using unsupervised learning for anomaly detection with three segments, PreQ, QRS, and PostS, based on the normal ECG. Two independent datasets, PTB-XL and China, were used in three experiments. We used a long short-term memory (LSTM)-based autoencoder to train the segments of the normal ECG. Based on the threshold of anomaly scores using mean squared error (MSE), it distinguished between normal and AF segments. In Experiment A, the best score was that of PreQ, which detected AF with an AUROC score of 0.96. In Experiment B and C for cross validation of each dataset, the best scores were also of PreQ, with AUROC scores of 0.9 and 0.95, respectively. To verify the significance of the anomaly score in distinguishing between AF and normal segments, we utilized an XG-Boosted model after generating anomaly scores in the three segments. The XG-Boosted model achieved an AUROC score of 0.98 and an F1 score of 0.94. AF detection using DL has been controversial among many physicians. However, our study differentiates itself from previous studies in that we can demonstrate evidence that distinguishes AF from normal segments based on the anomaly score.

3.
Langmuir ; 35(39): 12656-12664, 2019 10 01.
Article in English | MEDLINE | ID: mdl-31490695

ABSTRACT

Exploration of the bioinspired silicification of artificial scaffolds is crucial to understanding and engineering the hierarchically complex and elaborate three-dimensional (3D) frustules of diatoms, which have high porosity and mechanical stability with related gas diffusion and storage properties. Herein, we report on the bioinspired silicification of the nanostructured surfaces of hexagonally close-packed silica bead (hc-SB) arrays using a liquid-phase deposition (LPD) method. This process, governed by the kinetics of silicification, was controlled using the concentration of the reactants and the reaction temperature and monitored in real time using a quartz-crystal microbalance, which allowed the investigation of the silicification on the surface during the LPD reaction. These heterogeneous LPD reactions on hc-SB arrays were optimized to mimic natural 3D hierarchical structures. Anisotropic silicification of the nanostructures occurred owing to differences in the energy and local concentration of silicic acid on the nanostructured surface. A 3D hierarchical pore network was realized via a heterogeneous LPD reaction by controlling the size, location, and arrangement of the SBs. We believe that our silicification process on nanostructured surfaces can lead to great improvements in the bioinspired morphogenesis-based engineering of 3D hierarchical structures.

4.
Nanoscale ; 11(12): 5693-5704, 2019 Mar 21.
Article in English | MEDLINE | ID: mdl-30865198

ABSTRACT

Controlling the interactions between cells and viruses is critical for treating infected patients, preventing viral infections, and improving virus-based therapeutics. Chemical methods using small molecules and biological methods using proteins and nucleic acids are employed for achieving this control, albeit with limitations. We found, for the first time, that retroviral DNA integration patterns in the human genome, the result of complicated interactions between cells and viruses, can be engineered by adapting cells to the defined nanotopography of silica bead monolayers. Compared with cells on a flat glass surface, cells on beads with the highest curvature harbored retroviral DNAs at genomic sites near transcriptional start sites and CpG islands during infections at more than 50% higher frequencies. Furthermore, cells on the same type of bead layers contained retroviral DNAs in the genomic regions near cis-regulatory elements at frequencies that were 2.6-fold higher than that of cells on flat glass surfaces. Systems-level genetic network analysis showed that for cells on nanobeads with the highest curvature, the genes that would be affected by cis-regulatory elements near the retroviral integration sites perform biological functions related to chromatin structure and antiviral activities. Our unexpected observations suggest that novel engineering approaches based on materials with specific nanotopography can improve control over viral events.


Subject(s)
DNA, Viral/metabolism , Leukemia Virus, Murine/genetics , Nanotechnology/methods , CpG Islands , Gene Regulatory Networks , Genome, Human , HEK293 Cells , Humans , Nanostructures/chemistry , Silicon Dioxide/chemistry
5.
Chem Commun (Camb) ; 54(26): 3286-3289, 2018 Mar 27.
Article in English | MEDLINE | ID: mdl-29536994

ABSTRACT

Here, we investigated the relationship between the surface potentials and molecular interactions in the alucone films grown by molecular layer deposition. Varying the C-C bond order of the organic precursors induced variations in inter-molecular interactions, resulting in variation in the surface potential, associated with the work function of the films.

6.
Chem Asian J ; 11(24): 3487-3492, 2016 Dec 19.
Article in English | MEDLINE | ID: mdl-27791333

ABSTRACT

Understanding metal alloy migration in metal-catalyzed nanowires growth is a prerequisite for improving its potential applications in the field of nanodevices. Here, we explored the surface migration of Au alloys in vertically aligned Si nanowires with different cooling rates. We varied the diameter of Au alloys by controlling the thickness of Au film as a catalyst for SiNW growth, and found that the behavior of Au alloys migration is dependent on size of Au alloys. In addition, the size-dependent migration mechanism of Au alloys was investigated at different cooling rates, which is related to different Au-Si eutectics.

7.
Chem Asian J ; 11(13): 1878-82, 2016 Jul 05.
Article in English | MEDLINE | ID: mdl-27283959

ABSTRACT

The location-controlled epitaxial growth of vertically aligned Si nanowire (v-SiNW) arrays over large surface area was investigated with Au nanodisks (AuNDs) patterned by KrF stepper lithography. There are two steps for synthesizing v-SiNWs from an AuND pattern: annealing and growth. The annealing process induces the formation of a single Au nanoparticle (AuNP) from an AuND pattern, which consists of several cracked AuNPs. Here, the oxide layer between the AuNDs and Si substrate is necessary for impeding the diffusion of Si atoms into the AuNPs. However, the oxide layer must be removed for properly aligned epitaxial SiNW growth. These SiNW arrays in large area can contribute highly to improve a nanowire-based engineering by controlling the location of SiNWs with consistent pitch.

8.
ACS Appl Mater Interfaces ; 8(27): 17489-98, 2016 Jul 13.
Article in English | MEDLINE | ID: mdl-27314844

ABSTRACT

Investigation of molecular interactions in polymeric films is crucial for understanding and engineering multiscale physical phenomena correlated to device function and performance, but this often involves a compromise between theoretical and experimental data, because of poor film uniformity. Here, we report the intramolecular and intermolecular interactions inside the ultrathin and conformal hybrid organic-inorganic alucone films grown by molecular layer deposition, based on sequential and self-limiting surface reactions. Varying the carbon chain length of organic precursors, which affects their molecular flexibility, caused intramolecular interactions such as double reactions by bending of the molecular backbone, resulting in formation of hole vacancies in the films. Furthermore, intermolecular interactions in alucone polymeric films are dependent on the thermal kinetics of molecules, leading to binding failures and cross-linking at low and high growth temperatures, respectively. We illustrate these key interactions and identify molecular geometries and potential energies by density functional theory calculations.

9.
ACS Appl Mater Interfaces ; 8(18): 11788-95, 2016 05 11.
Article in English | MEDLINE | ID: mdl-27092573

ABSTRACT

Development of methods enabling the preparation of uniformly aligned polymer thin films at the molecular level is a prerequisite for realizing their optoelectronic characteristics as innovative materials; however, these methods often involve a compromise between scalability and accuracy. In this study, we have grown uniformly aligned polyurea thin films on a SiO2 substrate using molecular layer deposition (MLD) based on sequential and self-limiting surface reactions. By integrating plane-polarized Fourier-transform infrared, Raman spectroscopic tools, and density functional theory calculations, we demonstrated the uniform alignment of polyurea MLD films. Furthermore, the selective-wavelength absorption characteristics of thickness-controlled MLD films were investigated by integrating optical measurements and finite-difference time-domain simulations of reflection spectra, resulting from their thickness-dependent fine resonance with photons, which could be used as color filters in optoelectronics.

10.
Soft Matter ; 12(3): 674-7, 2016 Jan 21.
Article in English | MEDLINE | ID: mdl-26539746

ABSTRACT

Herein, we investigated the wetting behavior of hexagonally close-packed polystyrene bead arrays with different bead diameters and surface flatness. The contact angle was found to be influenced by the surface roughness as well as the contact area of the polystyrene bead array with a water droplet.

11.
Nano Lett ; 16(1): 675-80, 2016 01 13.
Article in English | MEDLINE | ID: mdl-26645112

ABSTRACT

In this work, we report that high-density, vertically grown silicon nanowires (vg-SiNWs) direct a new in vitro developmental pathway of primary hippocampal neurons. Neurons on vg-SiNWs formed a single, extremely elongated major neurite earlier than minor neurites, which led to accelerated polarization. Additionally, the development of lamellipodia, which generally occurs on 2D culture coverslips, was absent on vg-SiNWs. The results indicate that surface topography is an important factor that influences neuronal development and also provide implications for the role of topography in neuronal development in vivo.


Subject(s)
Hippocampus/chemistry , Nanowires/chemistry , Neurites/chemistry , Neurogenesis , Actins/chemistry , Animals , Axons/chemistry , Axons/physiology , Cell Culture Techniques , Cell Tracking/methods , Hippocampus/cytology , Rats , Silicon/chemistry
12.
Langmuir ; 31(14): 4290-8, 2015 Apr 14.
Article in English | MEDLINE | ID: mdl-25291628

ABSTRACT

The epitaxial growth of 1D nanostructures is of particular interest for future nanoelectronic devices such as vertical field-effect transistors because it directly influences transistor densities and 3D logic or memory architectures. Silicon nanowires (SiNWs) are a particularly important 1D nanomaterial because they possess excellent electronic and optical properties. What is more, the scalable fabrication of vertically aligned SiNW arrays presents an opportunity for improved device applications if suitable properties can be achieved through controlling the alignment and density of SiNWs, yet this is something that has not been reported in the case of SiNWs synthesized from Au films. This work therefore explores the controllable synthesis of vertically aligned SiNWs through the introduction of an annealing process prior to growth via a Au-catalyzed vapor-liquid-solid mechanism. The epitaxial growth of SiNWs was demonstrated to be achievable using SiCl4 as the Si precursor in chemical vapor deposition, whereas the alignment and density of the SiNWs could be controlled by manipulating the annealing time during the formation of Au nanoparticles (AuNPs) from Au films. During the annealing process, gold silicide was observed to form on the interface of the liquid-phase AuNPs, depending on the size of the AuNPs and the annealing time. This work therefore makes a valuable contribution to improving nanowire-based engineering by controlling its alignment and density as well as providing greater insight into the epitaxial growth of 1D nanostructures.

13.
Langmuir ; 31(1): 249-53, 2015 Jan 13.
Article in English | MEDLINE | ID: mdl-25494033

ABSTRACT

Liquid phase deposition (LPD) is a useful method for the production of oxide film with low reaction temperature and production cost. With the report that the LPD of oxide films is conformally processed with uniform thickness and composition, there has been significant attention given to investigating its kinetic controls and growth mechanism on the flat surface. In this work, we explored the LPD of silicon dioxide on the hexagonally close-packed silica beads array as a nanostructured surface. The deposition and etching reactions of SiO2 occurred locally and simultaneously on silica beads, and were distinguished from the amount of fumed silica added in LPD solution. From locally competitive reactions, we obtained the anisotropic morphology of close-packed silica beads, and proposed a mechanism for the local LPD of SiO2 driven by nanostructured surfaces. This work contributes highly to improve metal oxide-based engineering, and also provide greater insight into the topography-driven LPD.

14.
Eur J Med Chem ; 65: 315-22, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23732996

ABSTRACT

A new series of diarylureas and diarylamides possessing 1,3,4-triarylpyrazole scaffold was designed and synthesized. Their in vitro antiproliferative activities against NCI-60 cell line panel were tested. Most of the compounds showed strong and broad-spectrum antiproliferative activities. Compound 18 exerted sub-micromolar IC50 values over all the subpanels of nine different cancer types. Its IC50 value over MDA-MB-435 melanoma cell line was 27 nM. Compounds 10-13, 22, and 23 possessing urea spacer exerted lethal effect over the NCI-60 panel with mean %inhibitions more than 100% in single-dose testing. Compounds 13 and 23 with urea linker and 3',5'-bis(trifluoromethyl)phenyl terminal ring showed the highest mean %inhibition over the NCI-60 panel in single-dose testing, and showed high potencies and broad-spectrum anticancer activities in five-dose testing.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Pyrazoles/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Humans , Molecular Structure , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Structure-Activity Relationship
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