Sexual Maturation, Attitudes towards Sexual Maturity, and Body Esteem in Elementary-School Children

PURPOSE: The purpose of this study is to evaluate sexual maturation, attitudes toward sexual maturity, and body esteem in the sexual development of Korean elementary-school boys and girls. METHODS: A descriptive cross-sectional study was conducted with 399 fifth and sixth graders (192 boys and 207 girls). The data were analysed with a χ2 test, t-test, and Pearson correlation coefficients. RESULTS: Among the 207 girls, 70.5% had pubic hair growth, 68.1% had breast development, and 56.0% had a menstrual period. In boys, 59.4% of the 192 subjects experienced the development of external genitalia and 52.6% had pubic hair growth. Sexual maturation was related to grade (boys, t=7.07, p=.008; girls, t=12.76, p < .001), age (t=−2.20, p=.030; t=−4.11, p < .001), height (t=−5.16, p < .001; t=−7.52, p < .001), and weight (t=−2.89, p=.004; t=−5.19, p < .001) in both boys and girls. Girls were more likely to have sexual maturity than boys (χ2=22.29, p < .001). Boys showed more positive attitudes toward sexual maturity (t=2.10, p=.036) and higher body esteem (t=2.12, p=.035) than girls. CONCLUSION: This study shows that sexual maturation, attitude toward sexual maturity, and body esteem in sexual development differ between boys and girls. The findings indicate that it is necessary to develop a tailored sex-education program according to the sex of elementary-school children

Two-dimensional and three-dimensional magnetism in ultrathin epitaxial rare-earth metal films

This thesis reports the investigation of the magnetic behavior of ultrathin epitaxial films of the heavy rare-earth elements; Gd, Er, and Dy, grown with the technique of Molecular Beam Epitaxy (MBE). By employing advanced film fabrication techniques, each magnetic rare-earth element layer, between 0.1 and 10 atomic layers thick and magnetically separated from one another by thick spacers, is grown in layer-by-layer growth mode to insure high crystal quality. Magnetization of the resulting films is measured to identify the spin structures and the magnetic phases. The localized 4f spins in the rare-earth layers and complete interlayer magnetic separation give the present approach a unique advantage over the previously used experimental methods.Expounding on the capability to fabricate two-dimensional systems, this thesis explores the following questions. How do these systems behave in two dimension? At what thickness does the transition between the two-dimensional behavior and the three-dimensional behavior occur? What are the effects of exchange anisotropy caused by the anisotropic 4f electrons and the crystal field? What are the effects of the basal plane strain caused by lattice mismatch between spacer layers and magnetic elements?The answers can be summarized as follows. All the systems probed in this thesis display spin-glass phases in two dimension. Dimensional crossover occurs between 1-3 monolayer thickness in these films. The effect of the exchange anisotropy is reflected in the magnitude of the susceptibility along different axes. Strain, or lattice mismatch, introduces random anisotropy into the systems in the ultrathin films resulting in random axis magnet phases. The overall picture is a complex interplay of the exchange anisotropy of the magnetic element, the random anisotropy caused by the size difference between the spacer elements and the magnetic elements, randomness in exchange interaction due to the structural randomness, basal plane strain due to the spacer layer, and dimensional crossover as a function of the film thickness.U of I OnlyETDs are only available to UIUC Users without author permissio

A Comparative Study of Chirally Modified Platinum catalysts in Heterogeneous Enantioselective Hydrogenation

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Enantioselective hydrogenation of methyl pyruvate over Pt catalysts supported on amine-functionalized silica

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High-performance Pt catalysts supported on amine-functionalized silica for enantioselective hydrogenation of alpha-keto ester

Heterogeneous enantioselective catalysis is an attractive approach to produce enantiopure chemicals, which are key intermediates for pharmaceutical products. Herein, mesocellular silica foams (MCFs) functionalized by primary, secondary, and tertiary amine groups were used as supports for Pt nanoparticles. The catalytic performances of the Pt/amine-functionalized MCFs were evaluated for the enantioselective hydrogenation of methyl pyruvate in the presence of cinchonidine. Compared to Pt/MCF, the Pt/amine-functionalized MCFs exhibited enhanced activity and enantioselectivity. Particularly, 0.5 wt% Pt/NH2MCF showed a superior performance than 5 wt% Pt/Al2O3, a highly efficient catalyst in the enantioselective hydrogenation of a-keto esters, despite a 10 times lower Pt loading. Furthermore, the Pt/NH2-MCF yielded 100% conversion and 96% ee at 0.1 MPa H-2 pressure during nine successive cycles, thus showing high reusability. The excellent performance of the Pt/amine-functionalized MCFs is attributed to the formation of electron-deficient Pt species through strong interactions between the Pt nanoparticles and amine groups. (C) 2021 Elsevier Inc. All rights reserved.11Nsciescopu

Comparison of margin assessment between intraoperative digital and conventional specimen mammography in breast cancer: A preliminary study

Background: Although breast surgeons can request frozen section biopsies to evaluate margin status in breast-conserving surgery (BCS), specimen imaging is also a useful assessment tool. Intraoperative digital specimen mammography (IDSM) has recently been introduced in Korea. To estimate the clinical role of IDSM, this study compared the clinicopathologic factors of patients whose specimen was assessed with IDSM with those assessed using conventional specimen mammography (CSM). Methods: From October to December 2021, 78 breast cancer patients who underwent BCS were included in this study. The obtained specimens were assessed using IDSM (n = 44) and CSM (n = 34). Clinicopathologic factors included margin involvement status in specimen mammography and the results of frozen section biopsies. The radiation dose emitted from the specimen after mammography was measured using a portable device. Results: There were no significant differences in clinicopathological factors between the two groups, except the type of surgery for axillary lymph nodes. The closest distance from the margin to tumor was longer in the CSM group than in the IDSM group, although the difference was not statistically significant (p = 0.894). Margin involvement was accurately detected using IDSM due to the absence of compression (p < 0.001). In addition, the sensitivity and accuracy of IDSM were higher, and the false-negative rate was lower. Conclusion: Both specimen mammography methods were highly accurate in evaluating the margin involvement status. However, the margin status could be examined more precisely using IDSM because the specimen was not compressed to perform the examination. Because the IDSM system was installed in the operating room, it not only shortened performing routes but also reduced the operating time by providing immediate results

DNA sensors based on CNT-FET with floating electrodes

We report a successful development of a floating electrode-based DNA sensor with controllable responses. Here, metallic floating electrodes were fabricated to form Schottky barriers between carbon nanotubes and the floating electrodes. We showed that the sensor response could be enhanced by increasing the number of floating electrodes. We also analyzed the response of the sensors based on the Langmuir isotherm theory. (C) 2012 Elsevier B.V. All rights reserved

Development of a Korean Fracture Risk Score (KFRS) for Predicting Osteoporotic Fracture Risk: Analysis of Data from the Korean National Health Insurance Service.

Asian-specific prediction models for estimating individual risk of osteoporotic fractures are rare. We developed a Korean fracture risk prediction model using clinical risk factors and assessed validity of the final model.A total of 718,306 Korean men and women aged 50-90 years were followed for 7 years in a national system-based cohort study. In total, 50% of the subjects were assigned randomly to the development dataset and 50% were assigned to the validation dataset. Clinical risk factors for osteoporotic fracture were assessed at the biennial health check. Data on osteoporotic fractures during the follow-up period were identified by ICD-10 codes and the nationwide database of the National Health Insurance Service (NHIS).During the follow-up period, 19,840 osteoporotic fractures were reported (4,889 in men and 14,951 in women) in the development dataset. The assessment tool called the Korean Fracture Risk Score (KFRS) is comprised of a set of nine variables, including age, body mass index, recent fragility fracture, current smoking, high alcohol intake, lack of regular exercise, recent use of oral glucocorticoid, rheumatoid arthritis, and other causes of secondary osteoporosis. The KFRS predicted osteoporotic fractures over the 7 years. This score was validated using an independent dataset. A close relationship with overall fracture rate was observed when we compared the mean predicted scores after applying the KFRS with the observed risks after 7 years within each 10th of predicted risk.We developed a Korean specific prediction model for osteoporotic fractures. The KFRS was able to predict risk of fracture in the primary population without bone mineral density testing and is therefore suitable for use in both clinical setting and self-assessment. The website is available at http://www.nhis.or.kr