Correlations between pediatric obstructive sleep apnea and longitudinal growth

Park, Do-Yang,Choi, Ji Ho,Kang, So Young,Han, Jinjoo,Park, Hun Yi,Hwang, Jin Soon,Cho, Jae Ho,Cho, Min Hyuk,Kim, Hyun Jun Elsevier 2018 INTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGO Vol.106 No.-

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>Pediatric obstructive sleep apnea has a relatively high prevalence and has various negative health and behavioral consequences. Among the various complications of pediatric obstructive sleep apnea, growth disturbance is still controversial.</P> <P><B>Method</B></P> <P>745 pediatric subjects with obstructive sleep apnea diagnosed by in-lab polysomnography were enrolled, after excluding ineligible subjects with abnormal growth related factors. Height, weight, and BMI of enrolled patients were measured and statistically converted to z-scores, and the converted data were analyzed statistically with the polysomnographic results. Multiple linear regression were used to analyze the relationships between age, gender, z-score for weight, polysomnography results, and z-score for height.</P> <P><B>Results</B></P> <P>Patients with higher respiratory related index or lower mean/lowest oxygen saturation of PSG showed smaller z-score for height. Mean apnea hypopnea index and standard deviation of enrolled patients was 7.46 ± 12.92, with moderate severity. And mean z-score for height and standard deviation was 0.21 ± 1.15. Apnea hypopnea index, respiratory disturbance index, obstructive apnea index, and hypopnea index, respiratory related results of polysomnography, were statistically negative correlated with a z-score for height. And mean oxygen saturation and lowest oxygen saturation, oxygen saturation results of polysomnography, were statistically positive correlated with a z-score for height.</P> <P><B>Conclusions</B></P> <P>Respiratory related results and oxygen saturation results of polysomnography show negative and positive correlation with z-score for height. Therefore, pediatric obstructive sleep apnea have a negative effect on longitudinal growth.</P>

Photo-stimulated resistive switching of ZnO nanorods

Park, Jinjoo,Lee, Seunghyup,Yong, Kijung IOP Pub 2012 Nanotechnology Vol.23 No.38

<P>Resistive switching memory devices are promising candidates for emerging memory technologies because they yield outstanding device performance. Storage mechanisms for achieving high-density memory applications have been developed; however, so far many of them exhibit typical resistive switching behavior from the limited controlling conditions. In this study, we introduce photons as an unconventional stimulus for activating resistive switching behaviors. First, we compare the resistive switching behavior in light and dark conditions to describe how resistive switching memories can benefit from photons. Second, we drive the switching of resistance not by the electrical stimulus but only by the modulation of photon. ZnO nanorods were employed as a model system to demonstrate photo-stimulated resistive switching in high-surface-area nanomaterials, in which photo-driven surface states strongly affect their photoconductivity and resistance states. </P>

Effect of carrier injection stress in thin film solar cells by impedance spectroscopy.

Park, Seungman,Lee, Sunhwa,Park, Jinjoo,Kim, Youngkuk,Yoon, Kichan,Shin, Chonghoon,Baek, Seungsin,Lee, Youn-Jung,Yi, Junsin American Scientific Publishers 2012 Journal of nanoscience and nanotechnology Vol.12 No.4

<P>In amorphous silicon solar cells, degradation is directly related to V(oc), FF and cell performance. The dependence of the stability of thin film amorphous silicon solar cells is studied in terms of the volume fraction of B2H6 in the p-layer. When the volume fraction of B2H6 is increased by an order of magnitude, the doping-induced defects tend to increase quite rapidly. Low-doped p-type a-SiO(x) layers had better initial properties but rapidly degraded. Heavily doped p-type a-SiO(x) layers had lower initial properties but displayed better stability. The improvement in stability is explained in conjunction with the capacitance and resistance values of impedance spectroscopy. When the B2H6 gas flow rate is increased, the cell is degraded showing a capacitance decay decrease from 51.75% to less than 18.18%. In addition, the increase in the resistance decreased from 90.90% to 11.73%.</P>

Genomic alterations in <i>BCL2L1</i> and <i>DLC1</i> contribute to drug sensitivity in gastric cancer

Park, Hansoo,Cho, Sung-Yup,Kim, Hyerim,Na, Deukchae,Han, Jee Yun,Chae, Jeesoo,Park, Changho,Park, Ok-Kyoung,Min, Seoyeon,Kang, Jinjoo,Choi, Boram,Min, Jimin,Kwon, Jee Young,Suh, Yun-Suhk,Kong, Seong-H National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.40

<P><B>Significance</B></P><P>Gastric cancer (GC) is one of the major causes of cancer-related deaths worldwide, but targeted therapy for GC is limited. Here, we identified two druggable targets from genomic alteration profiling of 103 patients with GC from Asia and validated the target suitability using patient-derived GC xenograft models, which recapitulate the tumor biology observed in patients. Combination therapy of irinotecan (standard treatment) with a <I>BCL2L1</I> (<I>BCL2</I>-like 1)-targeted drug was effective in size reduction of GC tumors having amplification of the <I>BCL2L1</I> gene, and genomic mutations of deleted in liver cancer 1 (<I>DLC1</I>) were associated with increased sensitivity to a ROCK inhibitor. Therefore, our study strongly suggests that <I>BCL2L1</I> and <I>DLC1</I> can serve as targets for novel GC therapies.</P><P>Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Recent high-throughput analyses of genomic alterations revealed several driver genes and altered pathways in GC. However, therapeutic applications from genomic data are limited, largely as a result of the lack of druggable molecular targets and preclinical models for drug selection. To identify new therapeutic targets for GC, we performed array comparative genomic hybridization (aCGH) of DNA from 103 patients with GC for copy number alteration (CNA) analysis, and whole-exome sequencing from 55 GCs from the same patients for mutation profiling. Pathway analysis showed recurrent alterations in the Wnt signaling [<I>APC</I>, <I>CTNNB1</I>, and <I>DLC1</I> (deleted in liver cancer 1)], ErbB signaling (<I>ERBB2</I>, <I>PIK3CA</I>, and <I>KRAS</I>), and p53 signaling/apoptosis [<I>TP53</I> and <I>BCL2L1</I> (BCL2-like 1)] pathways. In 18.4% of GC cases (19/103), amplification of the antiapoptotic gene <I>BCL2L1</I> was observed, and subsequently a <I>BCL2L1</I> inhibitor was shown to markedly decrease cell viability in <I>BCL2L1</I>-amplified cell lines and in similarly altered patient-derived GC xenografts, especially when combined with other chemotherapeutic agents. In 10.9% of cases (6/55), mutations in <I>DLC1</I> were found and were also shown to confer a growth advantage for these cells via activation of Rho-ROCK signaling, rendering these cells more susceptible to a ROCK inhibitor. Taken together, our study implicates <I>BCL2L1</I> and <I>DLC1</I> as potential druggable targets for specific subsets of GC cases.</P>

Boron Doped Nanocrystalline Film with Improved Work Function as a Buffer Layer in Thin Film Silicon Solar Cells.

Park, Jinjoo,Shin, Chonghoon,Park, Hyeongsik,Jung, Junhee,Lee, Youn-Jung,Bong, Sungjae,Dao, Vinh Ai,Balaji, Nagarajan,Yi, Junsin American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.3

<P>We investigated thin film silicon solar cells with boron doped hydrogenated nanocrystalline silicon/ hydrogenated amorphous silicon oxide [p-type nc-Si:H/a-SiOx:H] layer. First, we researched the bandgap engineering of diborane (B2H6) doped wide bandgap hydrogenated nanocryslline silicon (p-type nc-Si:H) films, which have excellent electrical properties of high dark conductivity, and low activation energy. The films prepared with lower doping ratio and higher hydrogen dilution ratio had higher optical gap (Eg), with higher dark conductivity (??(d)), and lower activation energy (Ea). We controlled Eg from 2.10 eV to 1.75 eV, with ??(d) from 1.1 S/cm to 7.59 x 10(-3) S/cm, and Ea from 0.040 eV to 0.128 eV. Next, we focused on the fabrication of thin film silicon solar cells. By inserting p-type nc-Si:H film into the thin film silicon solar cells, we achieved a remarkable increase in the built-in potential from 0.803 eV to 0.901 eV. By forming p-type nc-Si:H film between SnO2:F/ZnO:Al (30 nm) and p-type a-SiOx:H layer, the solar cell properties of open circuit voltage (Voc), short circuit current density (Jsc), and efficiency (관) were improved by 3.7%, 9.2%, and 9.8%, respectively.</P>

ZnO Nanowire Based Photoelectrical Resistive Switches for Flexible Memory

Park, Jinjoo,Song, Hongseon,Lee, Eun Kwang,Oh, Joon Hak,Yong, Kijung The Electrochemical Society 2015 Journal of the Electrochemical Society Vol.162 No.9

<P>In this work, a non-volatile resistive optoelectronic memory was demonstrated in a flexible system that plays the dual roles of a reversible photo-reactive element and a signal-collecting element. We attempted to demonstrate the tactile sensor by detecting the rotation angle and bending angle of the wearable information appliance worn by the user. This motion-sensing for certain critical angle and information-storing functionality is enabled by photo-tunable resistive switching behaviors, which results from bending the flexible device in diverse convex angles with respect to the incident light direction. Furthermore, we investigated the basic mechanism of resistive photoelectrical switching behaviors by studying the effects of electrostatic barrier at the Au/ZnO junction, e.g., a Schottky barrier depending on the photonic and electric condition. Moreover, by employing a polymer structure, application in a prototype device provided improved endurance or retention of data.</P>

Fabrication of wide-gap p-type microcrystalline silicon-oxide emitter induced high built-in potential in heterojunction solar cells

Park Jinjoo 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.3

We have investigated a heterojunction intrinsic thin-layer (HIT) solar cell with a boron-doped hydrogenated nanocrystalline silicon-oxide emitter layer. First, we researched the band-gap engineering of boron ( B2H6)-doped wide-gap hydrogenated nanocrystalline silicon-oxide (p-type nc-SiO:H) films with good electrical properties in terms of the dark conductivity and the activation energy. The films prepared at lower doping ratios and higher hydrogen dilution ratios showed higher optical gaps (Eopt) with high horizontal (σd,//) or vertical dark conductivities (σd,⊥) and lower activation energies (Ea). Notably, all p-type nc-SiO:H films had better properties than boron-doped amorphous silicon (a-Si:H) films. We controlled Eopt from 2.13 to 2.33 eV with σd,// from 1.53 × 10−2 to 9.59 × 10−3 S/cm and with σd,⊥ from 4.56 × 10−7 to 2.53 × 10−8 S/cm; as well as Ea from 0.091 to 0.113 eV. Second, we showed a remarkable increase in the built-in potential by applying p-type nc-SiO:H films to HIT solar cells. The solar cell properties showed 4.05%, 6.02%, and 8.67% increases in the open-circuit voltage, fill factor, and efficiency, respectively, when a p-type nc-SiO:H emitter layer had been applied between the In2O3: Sn and the i-type a-Si:H layer. The mechanism of improvement is discussed using a methodical approach to the interfacial properties.

Improved Carrier Tunneling and Recombination in Tandem Solar Cell with p-type Nanocrystalline Si Intermediate Layer

Jinjoo Park,Sangho Kim,Pham duy Phong,Sunwha Lee,Junsin Yi 한국태양광발전학회 2020 Current Photovoltaic Research Vol.8 No.1

The power conversion efficiency (PCE) of a two-terminal tandem solar cell depends upon the tunnel-recombination junction (TRJ) between the top and bottom sub-cells. An optimized TRJ in a tandem cell helps improve its open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and efficiency (PCE). One of the parameters that affect the TRJ is the buffer layer thickness. Therefore, we investigated various TRJs by varying the thickness of the buffer or intermediate layer (TRJ-buffer) in between the highly doped p-type and n-type layers of the TRJ. The TRJ-buffer layer was p-type nc-Si:H, with a doping of 0.06%, an activation energy (Ea) of 43 meV, an optical gap (Eg) of 2.04 eV, and its thickness was varied from 0 nm to 125 nm. The tandem solar cells we investigated were a combination of a heterojunction with intrinsic thin layer (HIT) bottom sub-cell and an a-Si:H (amorphous silicon) top sub-cell. The initial cell efficiency without the TRJ buffer was 7.65% while with an optimized buffer layer, its efficiency improved to 11.74%, i.e., an improvement in efficiency by a factor of 1.53.

The Development Status of High-Power Electronic Selective Junction Solar Cell Technology

Jinjoo Park(박진주) 한국신재생에너지학회 2022 한국신재생에너지학회 학술대회논문집 Vol.2022 No.4

Front and Back TCO Research Review of a-Si/c-Si Heterojunction with Intrinsic Thin Layer (HIT) Solar Cell

Park, Hyeongsik,Lee, Youn-Jung,Park, Jinjoo,Kim, Youngkuk,Yi, Junsin,Lee, Youngseok,Kim, Sangho,Park, Chang-Kyun,Lim, Kyung-Jin The Korean Institute of Electrical and Electronic 2018 Transactions on Electrical and Electronic Material Vol.19 No.3

In this paper, we report a technical approach regarding an amorphous silicon (a-Si)/crystalline silicon (c-Si) heterojunction solar cell to solve the previous issues, and we investigate the applications of front and back transparent conductive oxides (TCOs) on this high-efficiency solar cell. The presentation of front and rear-emitter structure solar cells is included, and we investigate the TCO-material candidates for the Si heterojunction (SHJ) solar cell according to the electrical and optical properties. A high-quality TCO film is very important because it is linked to the efficiency of the c-Si-based silicon solar cell. The intention here is the applying of a high-efficiency SHJ solar cell by fabricating the high-quality TCO materials of the investigation of this study.