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UniversitySeoul, Seoul, South Korea

Research output, citation impact, and the most-cited recent papers from Chung-Ang University (South Korea). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
46.6K
Citations
2.1M
h-index
299
i10-index
48.5K
Also known as
Chung-Ang University중앙대학교

Top-cited papers from Chung-Ang University

Introducing EzTaxon-e: a prokaryotic 16S rRNA gene sequence database with phylotypes that represent uncultured species
Ok-Sun Kim, Yong‐Joon Cho, Kihyun Lee, Seok-Hwan Yoon +4 more
2011· INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY5.3Kdoi:10.1099/ijs.0.038075-0

Despite recent advances in commercially optimized identification systems, bacterial identification remains a challenging task in many routine microbiological laboratories, especially in situations where taxonomically novel isolates are involved. The 16S rRNA gene has been used extensively for this task when coupled with a well-curated database, such as EzTaxon, containing sequences of type strains of prokaryotic species with validly published names. Although the EzTaxon database has been widely used for routine identification of prokaryotic isolates, sequences from uncultured prokaryotes have not been considered. Here, the next generation database, named EzTaxon-e, is formally introduced. This new database covers not only species within the formal nomenclatural system but also phylotypes that may represent species in nature. In addition to an identification function based on Basic Local Alignment Search Tool (blast) searches and pairwise global sequence alignments, a new objective method of assessing the degree of completeness in sequencing is proposed. All sequences that are held in the EzTaxon-e database have been subjected to phylogenetic analysis and this has resulted in a complete hierarchical classification system. It is concluded that the EzTaxon-e database provides a useful taxonomic backbone for the identification of cultured and uncultured prokaryotes and offers a valuable means of communication among microbiologists who routinely encounter taxonomically novel isolates. The database and its analytical functions can be found at http://eztaxon-e.ezbiocloud.net/.

Present and Future of Surface-Enhanced Raman Scattering
Judith Langer, Dorleta Jiménez de Aberasturi, Javier Aizpurua, Ramón A. Álvarez‐Puebla +4 more
2019· ACS Nano3.7Kdoi:10.1021/acsnano.9b04224

The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products. In this Review, prominent authors from around the world joined together to summarize the state of the art in understanding and using SERS and to predict what can be expected in the near future in terms of research, applications, and technological development. This Review is dedicated to SERS pioneer and our coauthor, the late Prof. Richard Van Duyne, whom we lost during the preparation of this article.

Sample size determination and power analysis using the G*Power software
Hyun Kang
2021· Journal of Educational Evaluation for Health Professions2.3Kdoi:10.3352/jeehp.2021.18.17

Appropriate sample size calculation and power analysis have become major issues in research and publication processes. However, the complexity and difficulty of calculating sample size and power require broad statistical knowledge, there is a shortage of personnel with programming skills, and commercial programs are often too expensive to use in practice. The review article aimed to explain the basic concepts of sample size calculation and power analysis; the process of sample estimation; and how to calculate sample size using G*Power software (latest ver. 3.1.9.7; Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) with 5 statistical examples. The null and alternative hypothesis, effect size, power, alpha, type I error, and type II error should be described when calculating the sample size or power. G*Power is recommended for sample size and power calculations for various statistical methods (F, t, χ2, Z, and exact tests), because it is easy to use and free. The process of sample estimation consists of establishing research goals and hypotheses, choosing appropriate statistical tests, choosing one of 5 possible power analysis methods, inputting the required variables for analysis, and selecting the “calculate” button. The G*Power software supports sample size and power calculation for various statistical methods (F, t, χ2, z, and exact tests). This software is helpful for researchers to estimate the sample size and to conduct power analysis.

Observation of Reactor Electron Antineutrinos Disappearance in the RENO Experiment
J. K. Ahn, Sergey Chebotaryov, J. H. Choi, S. Choi +4 more
2012· Physical Review Letters1.9Kdoi:10.1103/physrevlett.108.191802

The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six $2.8\text{ }\text{ }{\mathrm{GW}}_{\mathrm{th}}$ reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 and 1383 m, respectively, from the reactor array center. In the 229 d data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of antineutrinos in the far detector is $0.920\ifmmode\pm\else\textpm\fi{}0.009(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.014(\mathrm{syst})$. From this deficit, we determine ${sin}^{2}2{\ensuremath{\theta}}_{13}=0.113\ifmmode\pm\else\textpm\fi{}0.013(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.019(\mathrm{syst})$ based on a rate-only analysis.

The prevention and handling of the missing data
Hyun Kang
2013· Korean journal of anesthesiology1.7Kdoi:10.4097/kjae.2013.64.5.402

Even in a well-designed and controlled study, missing data occurs in almost all research. Missing data can reduce the statistical power of a study and can produce biased estimates, leading to invalid conclusions. This manuscript reviews the problems and types of missing data, along with the techniques for handling missing data. The mechanisms by which missing data occurs are illustrated, and the methods for handling the missing data are discussed. The paper concludes with recommendations for the handling of missing data.

Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation
Idrees Khan, Khalid Saeed, Ivar Zekker, Baoliang Zhang +4 more
2022· Water1.5Kdoi:10.3390/w14020242

The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

Colorimetric Detection of Mercuric Ion (Hg<sup>2+</sup>) in Aqueous Media using DNA‐Functionalized Gold Nanoparticles
Jae‐Seung Lee, Min Su Han, Chad A. Mirkin
2007· Angewandte Chemie International Edition1.3Kdoi:10.1002/anie.200700269

Color is everything: Hg2+ in aqueous media is detected by the formation of thymidine–Hg2+–thymidine coordination complexes, which raises the melting temperature of the DNA-hybridized gold nanoparticle probes and thus the temperature at which the probes disperse and effect a purple-to-red color change. The method has very high sensitivity and selectivity, and it provides a simple and fast colorimetric readout (see picture). Mercury is a widespread pollutant with distinct toxicological profiles, and it exists in a variety of different forms (metallic, ionic, and as part of organic and inorganic salts and complexes). Solvated mercuric ion (Hg2+), one of the most stable inorganic forms of mercury,1 is a caustic and carcinogenic material with high cellular toxicity.2 The most common organic source of mercury, methyl mercury, can accumulate in the human body through the food chain and cause serious and permanent damage to the brain with both acute and chronic toxicity.3–5 Methyl mercury is generated by microbial biomethylation in aquatic sediments from water-soluble mercuric ion (Hg2+).4 Therefore, routine detection of Hg2+ is central to the environmental monitoring of rivers and larger bodies of water and for evaluating the safety of aquatically derived food supplies.5, 6 Several methods for the detection of Hg2+, based upon organic fluorophores7 or chromophores,8 semiconductor nanocrystals,9 cyclic voltammetry,10 polymeric materials,11 proteins,12 and microcantilevers,13 have been developed. Colorimetric methods, in particular, are extremely attractive because they can be easily read out with the naked eye, in some cases at the point of use. Although there are now several chromophoric colorimetric sensors for Hg2+,8 all of them are either limited with respect to sensitivity (current limit of detection≈1 μM) and selectivity, kinetically unstable, or incompatible with aqueous environments. Recently, DNA-functionalized gold nanoparticles (DNA–Au NPs) have been used in a variety of forms for the detection of proteins,14, 15 oligonucleotides,15–21 certain metal ions,22 and other small molecules.23, 24 DNA–Au NPs have high extinction coefficients (3–5 orders of magnitude higher than those of organic dye molecules)25 and unique distance-dependent optical properties that can be chemically programmed through the use of specific DNA interconnects, which allows one, in certain cases,16–20 to detect targets of interest through colorimetric means. Moreover, these structures, when hybridized to complementary particles, exhibit extremely sharp melting transitions, which have been used to enhance the selectivity of detection systems based upon them.16, 18, 20, 26 By using such an approach, one can typically detect nucleic acid targets in the low nanomolar to high picomolar target concentration range in colorimetric format. The ability to use such particles to detect Hg2+ in the nanomolar concentration range in colorimetric format would be a significant advance, especially when one considers that commercial systems for detecting Hg2+ rely on cumbersome inductively coupled plasma approaches that are not suitable for point-of-use applications. Herein, we present a highly selective and sensitive colorimetric detection method for Hg2+ that relies on thymidine–Hg2+–thymidine coordination chemistry27 and complementary DNA–Au NPs with deliberately designed T–T mismatches. When two complementary DNA–Au NPs are combined, they form DNA-linked aggregates that can dissociate reversibly with a concomitant purple-to-red color change.24, 28 For our novel colorimetric Hg2+ assay, however, we prepared two types of Au NPs (designated as probe A and probe B, see the Supporting Information), each functionalized with different thiolated-DNA sequences (probe A: 5′ HS-C10-A10-T-A10 3′, probe B: 5′ HS-C10-T10-T-T10 3′), which are complementary except for a single thymidine–thymidine mismatch (shown in bold; Scheme 1). Importantly, these particles also form stable aggregates and exhibit the characteristic sharp melting transitions (full width at half maximum<1 °C) associated with aggregates formed from perfectly complementary particles, but with a lower melting temperature Tm.17, 18 Since it is known that Hg2+ will coordinate selectively to the bases that make up a T–T mismatch, we hypothesized that Hg2+ would selectively bind to the T–T sites in our aggregates formed from mismatched strands and raise the Tm of the resulting structures.27 The analogous interaction with particle-free DNA leads to significant increases in Tm (ΔTm≈10 °C). Colorimetric detection of mercuric ion (Hg2+) using DNA–Au NPs. The assay begins by adding an aliquot of an aqueous solution of Hg2+ at a designated concentration to a solution of the DNA–Au NP aggregates formed from probes A and B (1.5 nM each) at room temperature (see the Supporting Information). The solution is then heated at a rate of 1 °C min−1 while its extinction is monitored at 525 nm, where the Au NP probes exhibit the maximum intensity in the visible region of the spectrum. The Tm is obtained at the maximum of the first derivative of the melting transition. Without Hg2+, the aggregates melt with a dramatic purple-to-red color change at about 46 °C. In the presence of Hg2+, however, the aggregates melt at temperatures higher than 46 °C because of the strong coordination of Hg2+ to the two thymidines that make up the T–T mismatch, thereby stabilizing the duplex DNA strands containing the T–T single base mismatches. To evaluate the sensitivity of the assay, different concentrations of Hg2+ from one stock solution were tested. When an Hg2+ sample was mixed with the Au NP probe aggregate solution, there was no noticeable change under the reaction conditions described above. Once heated, however, the aggregates melt with a significant purple-to-red color change at a specific temperature (Figure 1 a), which is linearly related to the concentration of Hg2+ over the entire concentration range studied (Figure 1 b). The present limit of detection for this system is approximately 100 nM (=20 ppb) Hg2+ (Figure 1 a), which, to the best of our knowledge, is the lowest ever reported for a colorimetric Hg2+ sensing system. Each increase in concentration of 1 μM results in an increase in Tm by about 5 °C, thus providing an easy way of determining Hg2+ concentration. a) Normalized melting curves of aggregates (probes A and B) with different concentrations of Hg2+. b) Graph of the Tm for the aggregates as a function of Hg2+ concentration. Three components of the assay contribute to its high sensitivity, selectivity, and quantitative capabilities: 1) the oligonucleotides, 2) the Au NPs, and 3) the oligonucleotide–nanoparticle conjugate. From the standpoint of the oligonucleotides, the chelating ability of the thymidines that form the mismatch in the oligonucleotide duplex is extremely selective for Hg2+. It is known that two thymidine residues, when geometrically preorganized in a DNA duplex, can behave as a chelate and form a tightly bound complex with Hg2+.29 From the standpoint of Au NPs, the high extinction coefficients of Au NPs (ca. 108 cm−1 m−1 for 15-nm Au NPs) can act as an amplifier for the perturbation of the Tm upon binding Hg2+, thus allowing detection limits in the ppb range. Conventional chromogenic chemosensors have relatively low extinction coefficients (typically around 105 cm−1 m−1), which limit their sensitivity at best to the micromolar concentration range. Finally, the sharp, highly cooperative melting properties of aggregates made from oligonucleotide–Au NP conjugates enable one to distinguish subtle differences in Tm clearly, thus providing a measure of the Hg2+ concentration from 100 nM to the low micromolar range.16–18 The selectivity of this system for Hg2+ was evaluated by testing the response of the assay to other environmentally relevant metal ions, including Mg2+, Pb2+, Cd2+, Co2+, Zn2+, Fe2+, Ni2+, Fe3+, Mn2+, Ca2+, Ba2+, Li+, K+, Cr3+, and Cu2+ (Figure 2 a and 2b) at a concentration of 1 μM. Only the Hg2+ sample shows a significantly higher Tm (ΔTm≈5 °C) relative to that of the blank. Indeed, at 47 °C, only the aggregate solution containing Hg2+ is purple, whereas all others have turned bright red. Pb2+ is the only other metal ion that influences the Tm of the aggregate, but only by a negligible amount (ΔTm≈0.8 °C). Importantly, this selectivity can be visualized with the naked eye (Figure 2 c). a) Normalized melting curves of the aggregates (probes A and B) in the presence of metal ions (each at 1 μM). b) Graph showing the difference between the Tm of the aggregates of the blank and that of the aggregates with different metal ions: 1: blank; 2: Hg2+; 3: Li+; 4: Cd2+; 5: Ca2+; 6: Ba2+; 7: Mn2+; 8: Mg2+; 9: Zn2+; 10: Ni2+; 11: Fe2+; 12: Co2+; 13: Fe3+; 14: K+; 15: Cr3+; 16: Pb2+; 17: Cu2+. c) Color change of the aggregates (probes A and B, each at 1.5 nM) in the presence of various representative metal ions (each at 1 μM) upon heating from room temperature (RT) to 47 °C. The colorimetric results for Cu2+ are not shown, as the data were taken after initial submission of the manuscript; see the Supporting Information. Because of the thiophilic nature of Hg2+, we considered the possibility that it could be removing the thiolated oligonucleotides from the surface of the gold particle, which could result in nonuniformity of the assay and a potential loss of sensitivity and accuracy. To determine if this was occurring, we utilized fluorophore-labeled oligonucleotides to evaluate the number of DNA strands per particle at various Hg2+ concentrations (0.5, 1, and 2 μM over 8 h; oligonucleotide sequence: 5′ HS-C10-A10-T-A10-(6-FAM) 3′; see the Supporting Information). Significantly, Hg2+ shows no evidence of fluorophore quenching, whereas the gold particle is an excellent quencher of fluorescence. Therefore, if the fluorophore-labeled oligonucleotides are removed from the particles they can be easily identified and quantified by fluorescence spectroscopy. The coverage of DNA at the start of the reaction was determined to be approximately 70 strands per particle by using literature methods.28, 30 The mercuric ion, regardless of the concentrations studied, has very little effect on the surface coverage of the DNA (Table 1). Even at elevated temperature (50 °C), there is less than 10 % loss of DNA from the surface of the particle even after prolonged heating (8 h) (Table 1),30 which suggests that the particle probes will be stable over any reasonable assay conditions. Temp. Portion Mercuric Ion Concentration 0.5 μM 1 μM 2 μM RT in the supernatant 2.1±1.0 1.6±1.3 1.8±1.2 on the particles 68.0±0.9 68.9±1.8 68.1±2.0 50 °C in the supernatant 5.9±0.2 6.0±0.8 6.1±1.3 on the particles 64.7±1.1 64.1±0.8 65.0±2.2 In conclusion, we have developed a colorimetric method to detect Hg2+ using DNA–Au NPs in aqueous media with very high selectivity and sensitivity. This method is enzyme-free and does not require specialized equipment other than a temperature control unit. The concentration of Hg2+ can be determined by the change of the solution color at a given temperature or the melting temperature (Tm) of the DNA–Au NP aggregates. Unlike most of the chemosensors for Hg2+ which have been evaluated in organic media or organic–aqueous mixtures owing to their low water-solubility, the high water solubility of the oligonucleotide-modified gold nanoparticle probes allow this assay to be performed in aqueous media without the need for organic cosolvents. Significantly, this method can in principle be used to detect other metal ions by substituting the thymidine in our study with synthetic artificial bases that selectively bind other metal ions.31 Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z700269_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options
Chang-Ro Lee, Jung Hun Lee, Moonhee Park, Kwang Seung Park +4 more
2017· Frontiers in Cellular and Infection Microbiology1.0Kdoi:10.3389/fcimb.2017.00055

Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of -lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized.

MIMO‐OFDM Wireless Communications with MATLAB®
Yong Soo Cho, Jaekwon Kim, Won Young Yang, Chung G. Kang
20101.0Kdoi:10.1002/9780470825631

MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11n), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). In MIMO-OFDM Wireless Communications with MATLAB, the authors provide a comprehensive introduction to the theory and practice of wireless channel modeling, OFDM, and MIMO, using MATLAB programs to simulate the various techniques on MIMO-OFDM systems. One of the only books in the area dedicated to explaining simulation aspects Covers implementation to help cement the key concepts Uses materials that have been classroom-tested in numerous universities Provides the analytic solutions and practical examples with downloadable MATLAB codes Simulation examples based on actual industry and research projects Presentation slides with key equations and figures for instructor use MIMO-OFDM Wireless Communications with MATLAB is a key text for graduate students in wireless communications. Professionals and technicians in wireless communication fields, graduate students in signal processing, as well as senior undergraduates majoring in wireless communications will find this book a practical introduction to the MIMO-OFDM techniques. Instructor materials and MATLAB code examples available for download at www.wiley.com/go/chomimo

Pharmaceutical particle technologies: An approach to improve drug solubility, dissolution and bioavailability
Prakash Khadka, Jieun Ro, Hyeongmin Kim, Iksoo Kim +4 more
2014· Asian Journal of Pharmaceutical Sciences980doi:10.1016/j.ajps.2014.05.005

Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral administration. The particle technology involves several approaches from the conventional size reduction processes to the newer, novel particle technologies that modify the solubility properties of the drugs and produce solid, powdered form of the drugs that are readily soluble in water and can be easily formulated into various dosage forms. This review highlights the solid particle technologies available for improving solubility, dissolution and bioavailability of drugs with poor aqueous solubility.

Surface Electromyography Signal Processing and Classification Techniques
Rafi Hassan Chowdhury, Mamun Bin Ibne Reaz, Mohd Helmi Ali, Ashrif A. Bakar +2 more
2013· Sensors967doi:10.3390/s130912431

Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.

Twenty-Eight-Day Oral Toxicity, Genotoxicity, and Gender-Related Tissue Distribution of Silver Nanoparticles in Sprague-Dawley Rats
Yong Soon Kim, Jin Sik Kim, Hyun Sun Cho, Dae Sik Rha +4 more
2008· Inhalation Toxicology879doi:10.1080/08958370701874663

The antibacterial effect of silver nanoparticles has resulted in their extensive application in health, electronic, and home products. However, while the population exposed to silver nanoparticles continues to increase with ever new applications, silver nanoparticles remain a controversial research area as regards their toxicity to biological systems. In particular, the oral toxicity of silver nanoparticles is of particular concern to ensure public and consumer health. Accordingly, this study tested the oral toxicity of silver nanoparticles (60 nm) over a period of 28 days in Sprague-Dawley rats following Organization for Economic Cooperation and Development (OECD) test guideline 407 with Good Laboratory Practice (GLP) application. Eight-week-old rats, weighing about 283 g for the males and 192 g for the females, were divided into four 4 groups (10 rats in each group): vehicle control, low-dose group (30 mg/kg), middle-dose group (300 mg/kg), and high-dose group (1000 mg/kg). After 28 days of exposure, the blood biochemistry and hematology were investigated, along with a histopathological examination and silver distribution study. The male and female rats did not show any significant changes in body weight relative to the doses of silver nanoparticles during the 28-day experiment. However, some significant dose-dependent changes were found in the alkaline phsophatase and cholesterol values in either the male or female rats, seeming to indicate that exposure to over more than 300 mg of silver nanoparticles may result in slight liver damage. There were no statistically significant differences in the micronucleated polychromatic erythrocytes (MN PCEs) or ratio of polychromatic erythrocytes among the total erythrocytes after silver nanoparticle exposure when compared with the control. Therefore, the present results suggest that silver nanoparticles do not induce genetic toxicity in male and female rat bone marrow in vivo. Nonetheless, the tissue distribution of silver nanopaticles did show a dose-dependent accumulation of silver content in all the tissues examined. In particular, a gender-related difference in the accumulation of silver was noted in the kidneys, with a twofold increase in the female kidneys when compared with the male kidneys.

Gold Nanoparticles for Photothermal Cancer Therapy
Jeremy B. Vines, Jee-Hyun Yoon, Na-Eun Ryu, Dong-Jin Lim +1 more
2019· Frontiers in Chemistry876doi:10.3389/fchem.2019.00167

Gold is a multifunctional material that has been utilized in medicinal applications for centuries because it has been recognized for its bacteriostatic, anticorrosive, and antioxidative properties. Modern medicine makes routine, conventional use of gold and has even developed more advanced applications by taking advantage of its ability to be manufactured at the nanoscale and functionalized because of the presence of thiol and amine groups, allowing for the conjugation of various functional groups such as targeted antibodies or drug products. It has been shown that colloidal gold exhibits localized plasmon surface resonance (LPSR), meaning that gold nanoparticles can absorb light at specific wavelengths, resulting in photoacoustic and photothermal properties, making them potentially useful for hyperthermic cancer treatments and medical imaging applications. Modifying gold nanoparticle shape and size can change their LPSR photochemical activities, thereby also altering their photothermal and photoacoustic properties, allowing for the utilization of different wavelengths of light, such as light in the near-infrared spectrum. By manufacturing gold in a nanoscale format, it is possible to passively distribute the material through the body, where it can localize in tumors (which are characterized by leaky blood vessels) and be safely excreted through the urinary system. In this paper, we give a quick review of the structure, applications, recent advancements, and potential future directions for the utilization of gold nanoparticles in cancer therapeutics.

Integrative functional genomic analysis of human brain development and neuropsychiatric risks
Mingfeng Li, Gabriel Santpere, Yuka Imamura Kawasawa, Oleg V. Evgrafov +4 more
2018· Science871doi:10.1126/science.aat7615

INTRODUCTION The brain is responsible for cognition, behavior, and much of what makes us uniquely human. The development of the brain is a highly complex process, and this process is reliant on precise regulation of molecular and cellular events grounded in the spatiotemporal regulation of the transcriptome. Disruption of this regulation can lead to neuropsychiatric disorders. RATIONALE The regulatory, epigenomic, and transcriptomic features of the human brain have not been comprehensively compiled across time, regions, or cell types. Understanding the etiology of neuropsychiatric disorders requires knowledge not just of endpoint differences between healthy and diseased brains but also of the developmental and cellular contexts in which these differences arise. Moreover, an emerging body of research indicates that many aspects of the development and physiology of the human brain are not well recapitulated in model organisms, and therefore it is necessary that neuropsychiatric disorders be understood in the broader context of the developing and adult human brain. RESULTS Here we describe the generation and analysis of a variety of genomic data modalities at the tissue and single-cell levels, including transcriptome, DNA methylation, and histone modifications across multiple brain regions ranging in age from embryonic development through adulthood. We observed a widespread transcriptomic transition beginning during late fetal development and consisting of sharply decreased regional differences. This reduction coincided with increases in the transcriptional signatures of mature neurons and the expression of genes associated with dendrite development, synapse development, and neuronal activity, all of which were temporally synchronous across neocortical areas, as well as myelination and oligodendrocytes, which were asynchronous. Moreover, genes including MEF2C , SATB2 , and TCF4 , with genetic associations to multiple brain-related traits and disorders, converged in a small number of modules exhibiting spatial or spatiotemporal specificity. CONCLUSION We generated and applied our dataset to document transcriptomic and epigenetic changes across human development and then related those changes to major neuropsychiatric disorders. These data allowed us to identify genes, cell types, gene coexpression modules, and spatiotemporal loci where disease risk might converge, demonstrating the utility of the dataset and providing new insights into human development and disease. Spatiotemporal dynamics of human brain development and neuropsychiatric risks. Human brain development begins during embryonic development and continues through adulthood (top). Integrating data modalities (bottom left) revealed age- and cell type–specific properties and global patterns of transcriptional dynamics, including a late fetal transition (bottom middle). We related the variation in gene expression (brown, high; purple, low) to regulatory elements in the fetal and adult brains, cell type–specific signatures, and genetic loci associated with neuropsychiatric disorders (bottom right; gray circles indicate enrichment for corresponding features among module genes). Relationships depicted in this panel do not correspond to specific observations. CBC, cerebellar cortex; STR, striatum; HIP, hippocampus; MD, mediodorsal nucleus of thalamus; AMY, amygdala.

Population of Merging Compact Binaries Inferred Using Gravitational Waves through GWTC-3
R. Abbott, T. D. Abbott, F. Acernese, K. Ackley +4 more
2023· Physical Review X867doi:10.1103/physrevx.13.011048

We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star–black hole mergers. We infer the binary neutron star merger rate to be between 10 and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>1700</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:msup><a:mrow><a:mi>Gpc</a:mi></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>3</a:mn></a:mrow></a:msup><a:mtext> </a:mtext><a:msup><a:mrow><a:mi>yr</a:mi></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>1</a:mn></a:mrow></a:msup></a:mrow></a:math> and the neutron star–black hole merger rate to be between 7.8 and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mn>140</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:msup><c:mrow><c:mi>Gpc</c:mi></c:mrow><c:mrow><c:mo>−</c:mo><c:mn>3</c:mn></c:mrow></c:msup><c:mtext> </c:mtext><c:msup><c:mrow><c:mi>yr</c:mi></c:mrow><c:mrow><c:mo>−</c:mo><c:mn>1</c:mn></c:mrow></c:msup></c:mrow></c:math>, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods used in this work. We infer the binary black hole merger rate, allowing for evolution with redshift, to be between 17.9 and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:mn>44</e:mn><e:mtext> </e:mtext><e:mtext> </e:mtext><e:msup><e:mrow><e:mi>Gpc</e:mi></e:mrow><e:mrow><e:mo>−</e:mo><e:mn>3</e:mn></e:mrow></e:msup><e:mtext> </e:mtext><e:msup><e:mrow><e:mi>yr</e:mi></e:mrow><e:mrow><e:mo>−</e:mo><e:mn>1</e:mn></e:mrow></e:msup></e:mrow></e:math> at a fiducial redshift (<g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>z</g:mi><g:mo>=</g:mo><g:mn>0.2</g:mn></g:math>). The rate of binary black hole mergers is observed to increase with redshift at a rate proportional to <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mo stretchy="false">(</i:mo><i:mn>1</i:mn><i:mo>+</i:mo><i:mi>z</i:mi><i:msup><i:mo stretchy="false">)</i:mo><i:mi>κ</i:mi></i:msup></i:math> with <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>κ</m:mi><m:mo>=</m:mo><m:mn>2.</m:mn><m:msubsup><m:mn>9</m:mn><m:mrow><m:mo>−</m:mo><m:mn>1.8</m:mn></m:mrow><m:mrow><m:mo>+</m:mo><m:mn>1.7</m:mn></m:mrow></m:msubsup></m:math> for <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:mi>z</o:mi><o:mo>≲</o:mo><o:mn>1</o:mn></o:math>. Using both binary neutron star and neutron star–black hole binaries, we obtain a broad, relatively flat neutron star mass distribution extending from <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"><q:msubsup><q:mn>1.2</q:mn><q:mrow><q:mo>−</q:mo><q:mn>0.2</q:mn></q:mrow><q:mrow><q:mo>+</q:mo><q:mn>0.1</q:mn></q:mrow></q:msubsup></q:math> to <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:msubsup><s:mn>2.0</s:mn><s:mrow><s:mo>−</s:mo><s:mn>0.3</s:mn></s:mrow><s:mrow><s:mo>+</s:mo><s:mn>0.3</s:mn></s:mrow></s:msubsup><s:msub><s:mi>M</s:mi><s:mo stretchy="false">⊙</s:mo></s:msub></s:math>. We confidently determine that the merger rate as a function of mass sharply declines after the expected maximum neutron star mass, but cannot yet confirm or rule out the existence of a lower mass gap between neutron stars and black holes. We also find the binary black hole mass distribution has localized over- and underdensities relative to a power-law distribution, with peaks emerging at chirp masses of <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"><v:msubsup><v:mn>8.3</v:mn><v:mrow><v:mo>−</v:mo><v:mn>0.5</v:mn></v:mrow><v:mrow><v:mo>+</v:mo><v:mn>0.3</v:mn></v:mrow></v:msubsup></v:math> and <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"><x:msubsup><x:mn>27.9</x:mn><x:mrow><x:mo>−</x:mo><x:mn>1.8</x:mn></x:mrow><x:mrow><x:mo>+</x:mo><x:mn>1.9</x:mn></x:mrow></x:msubsup><x:msub><x:mi>M</x:mi><x:mo stretchy="false">⊙</x:mo></x:msub></x:math>. While we continue to find that the mass distribution of a binary’s more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above approximately <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"><ab:mn>60</ab:mn><ab:msub><ab:mi>M</ab:mi><ab:mo stretchy="false">⊙</ab:mo></ab:msub></ab:math>, which would indicate the presence of a upper mass gap. Observed black hole spins are small, with half of spin magnitudes below <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"><db:msub><db:mi>χ</db:mi><db:mi>i</db:mi></db:msub><db:mo>≈</db:mo><db:mn>0.25</db:mn></db:math>. While the majority of spins are preferentially aligned with the orbital angular momentum, we infer evidence of antialigned spins among the binary population. We observe an increase in spin magnitude for systems with more unequal-mass ratio. We also observe evidence of misalignment of spins relative to the orbital angular momentum. Published by the American Physical Society 2023

Understanding the Model Size Effect on SEM Fit Indices
Dexin Shi, Taehun Lee, Alberto Maydeu‐Olivares
2018· Educational and Psychological Measurement865doi:10.1177/0013164418783530

This study investigated the effect the number of observed variables ( p) has on three structural equation modeling indices: the comparative fit index (CFI), the Tucker–Lewis index (TLI), and the root mean square error of approximation (RMSEA). The behaviors of the population fit indices and their sample estimates were compared under various conditions created by manipulating the number of observed variables, the types of model misspecification, the sample size, and the magnitude of factor loadings. The results showed that the effect of p on the population CFI and TLI depended on the type of specification error, whereas a higher p was associated with lower values of the population RMSEA regardless of the type of model misspecification. In finite samples, all three fit indices tended to yield estimates that suggested a worse fit than their population counterparts, which was more pronounced with a smaller sample size, higher p, and lower factor loading.

Translation of scales in cross‐cultural research: issues and techniques
EunSeok Cha, Kevin H. Kim, Judith A. Erlen
2007· Journal of Advanced Nursing837doi:10.1111/j.1365-2648.2007.04242.x

AIMS: This paper is a report of a study designed to: (i) describe issues and techniques of translation of standard measures for use in international research; (ii) identify a user-friendly and valid translation method when researchers have limited resources during translation procedure; and (iii) discuss translation issues using data from a pilot study as an example. BACKGROUND: The process of translation is an important part of cross-cultural studies. Cross-cultural researchers are often confronted by the need to translate scales from one language to another and to do this with limited resources. METHOD: The lessons learned from our experience in a pilot study are presented to underline the importance of using appropriate translation procedures. The issues of the back-translation method are discussed to identify strategies to ensure success when translating measures. FINDINGS: A combined technique is an appropriate method to maintain the content equivalences between the original and translated instruments in international research. There are several possible combinations of translation techniques. However, there is no gold standard of translation techniques because the research environment (e.g. accessibility and availability of bilingual people) and the research questions are different. CONCLUSIONS: It is important to use appropriate translation procedures and to employ a combined translation technique based on the research environment and questions.

Record High Hole Mobility in Polymer Semiconductors via Side-Chain Engineering
Il Kang, Hui‐Jun Yun, Dae Sung Chung, Soon‐Ki Kwon +1 more
2013· Journal of the American Chemical Society816doi:10.1021/ja405112s

Charge carrier mobility is still the most challenging issue that should be overcome to realize everyday organic electronics in the near future. In this Communication, we show that introducing smart side-chain engineering to polymer semiconductors can facilitate intermolecular electronic communication. Two new polymers, P-29-DPPDBTE and P-29-DPPDTSE, which consist of a highly conductive diketopyrrolopyrrole backbone and an extended branching-position-adjusted side chain, showed unprecedented record high hole mobility of 12 cm(2)/(V·s). From photophysical and structural studies, we found that moving the branching position of the side chain away from the backbone of these polymers resulted in increased intermolecular interactions with extremely short π-π stacking distances, without compromising solubility of the polymers. As a result, high hole mobility could be achieved even in devices fabricated using the polymers at room temperature.

Molecular Imprinting: Green Perspectives and Strategies
Maryam Arabi, Abbas Ostovan, Jinhua Li, Xiaoyan Wang +3 more
2021· Advanced Materials748doi:10.1002/adma.202100543

Advances in revolutionary technologies pose new challenges for human life; in response to them, global responsibility is pushing modern technologies toward greener pathways. Molecular imprinting technology (MIT) is a multidisciplinary mimic technology simulating the specific binding principle of enzymes to substrates or antigens to antibodies; along with its rapid progress and wide applications, MIT faces the challenge of complying with green sustainable development requirements. With the identification of environmental risks associated with unsustainable MIT, a new aspect of MIT, termed green MIT, has emerged and developed. However, so far, no clear definition has been provided to appraise green MIT. Herein, the implementation process of green chemistry in MIT is demonstrated and a mnemonic device in the form of an acronym, GREENIFICATION, is proposed to present the green MIT principles. The entire greenificated imprinting process is surveyed, including element choice, polymerization implementation, energy input, imprinting strategies, waste treatment, and recovery, as well as the impacts of these processes on operator health and the environment. Moreover, assistance of upgraded instrumentation in deploying greener goals is considered. Finally, future perspectives are presented to provide a more complete picture of the greenificated MIT road map and to pave the way for further development.

Human Exposure and Health Effects of Inorganic and Elemental Mercury
Jung‐Duck Park, Wei Zheng
2012· Journal of Preventive Medicine and Public Health748doi:10.3961/jpmph.2012.45.6.344

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety.