Capacitive Control of Spontaneously Induced Electrical Charge of Droplet by Electric Field-Assisted Pipetting

The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting. Hence, a method for controlling and removing the electrical charge needs to be developed. In this study, by using the electrode-deposited pipet tip (E-pipet tip), the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled. The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model. Furthermore, a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications. Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled, the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet, such as the surface oscillation and evaporation of charged droplets.1143Ysciescopu

Experiences of and barriers to transition-related healthcare among Korean transgender adults: focus on gender identity disorder diagnosis, hormone therapy, and sex reassignment surgery

OBJECTIVES Transgender people may encounter barriers to transition-related healthcare services. This study aimed to investigate the experiences of transition-related healthcare and barriers to those procedures among transgender adults in Korea. METHODS In 2017, we conducted a nationwide cross-sectional survey of 278 transgender adults, which named Rainbow Connection Project II, in Korea. We assessed the prevalence of transition-related healthcare, including gender identity disorder (GID) diagnosis, hormone therapy, and sex reassignment surgery. To understand the barriers to those procedures, we also asked participants for their reasons for not receiving each procedure. Further, this study examined their experiences of and the reasons for using non-prescribed hormone medications. RESULTS Of transgender people participated in the survey, 91.0% (n=253/278) were diagnosed with GID, 88.0% (n=243/276) received hormone therapy, and 42.4% (n=115/271) have had any kind of sex reassignment surgery. Cost was the most common barrier to transition-related healthcare among Korean transgender adults. Other common barriers were identified as follows: negative experiences in healthcare settings, lack of specialized healthcare professionals and facilities, and social stigma against transgender people. Among those who had taken hormone medications, 25.1% (n=61/243) reported that they had ever purchased them without a prescription. CONCLUSIONS Our findings suggest that barriers to transition-related healthcare exist in Korea and constrain transgender individuals’ safe access to the needed healthcare. Institutional interventions are strongly recommended to improve access to transition-related healthcare. These interventions include provision of programs to train Korean healthcare professionals and expansion of national health insurance to include these procedures

Salinity-Triggered Responses in Plant Apical Meristems for Developmental Plasticity

Salt stress severely affects plant growth and development. The plant growth and development of a sessile organism are continuously regulated and reformed in response to surrounding environmental stress stimuli, including salinity. In plants, postembryonic development is derived mainly from primary apical meristems of shoots and roots. Therefore, to understand plant tolerance and adaptation under salt stress conditions, it is essential to determine the stress response mechanisms related to growth and development based on the primary apical meristems. This paper reports that the biological roles of microRNAs, redox status, reactive oxygen species (ROS), nitric oxide (NO), and phytohormones, such as auxin and cytokinin, are important for salt tolerance, and are associated with growth and development in apical meristems. Moreover, the mutual relationship between the salt stress response and signaling associated with stem cell homeostasis in meristems is also considered

Transcriptomics Using the Enriched Arabidopsis Shoot Apex Reveals Developmental Priming Genes Involved in Plastic Plant Growth under Salt Stress Conditions

In the shoot apical meristem (SAM), the homeostasis of the stem cell population supplying new cells for organ formation is likely a key mechanism of multicellular plant growth and development. As plants are sessile organisms and constantly encounter environmental abiotic stresses, postembryonic development from the shoot stem cell population must be considered with surrounding abiotic stresses for plant adaptation. However, the underlying molecular mechanisms for plant adaptation remain unclear. Previous studies found that the stem-cell-related mutant clv3-2 has the property of salt tolerance without the differential response of typical stress-responsive genes compared to those in WT Ler. Based on these facts, we hypothesized that shoot meristems contain developmental priming genes having comprehensively converged functions involved in abiotic stress response and development. To better understand the biological process of developmental priming genes in the SAM, we performed RNA sequencing (RNA-seq) and transcriptome analysis through comparing genome-wide gene expression profiles between enriched shoot apex and leaf tissues. As a result, 121 putative developmental priming genes differentially expressed in the shoot apex compared to the leaf were identified under normal and salt stress conditions. RNA-seq experiments also revealed the shoot apex-specific responsive genes for salt stress conditions. Based on combinatorial comparisons, 19 developmental priming genes were finally identified, including developmental genes related to cell division and abiotic/biotic-stress-responsive genes. Moreover, some priming genes showed CLV3-dependent responses under salt stress conditions in the clv3-2. These results presumably provide insight into how shoot meristem tissues have relatively high viability against stressful environmental conditions for the developmental plasticity of plants

Enhancing the solubility of recombinant Akt1 in Escherichia coli with an artificial transcription factor library

A combinatorial library of artificial transcription factors (ATFs) was introduced into the bacterial cells that expressed the Akt1-GFP fusion protein. By measuring the level of fluorescence generated by the transformed E coli cells, we were able to obtain clones in which ATFs increased the solubility of the Akt1. Our results show that ATF library is a useful toot for increasing the solubility of selected recombinant proteins in E coli.

비결정질 실리콘 박막 상에서의 광열 유동을 이용한 액적 조작

국내22kc

Pure Piezoelectricity Generation by a Flexible Nanogenerator Based on Lead Zirconate Titanate Nanofibers

Lead zirconate titanate (PbZr0.52Ti0.48O3, PZT) alloys have been extensively studied to be used for piezoelectric nanogenerators to harvest energy from mechanical motions. In this study, PZT nanofiber-based nanogenerators were fabricated to test their true piezoelectric performance without the triboelectric effect. Aligned PZT nanofibers were fabricated by a sol–gel electrospinning process. The thickness, area, and orientation of the PZT textile made by electrospinning a PZT solution onto multipair metal wires or metal mesh were controlled to form a composite textile. After the calcination, the PZT textile mixed with polydimethylsiloxane was placed between two flexible indium-doped tin oxide–polyethylene naphthalate substrates. The performance parameters of the nanogenerators were investigated under the bending motion, which excludes the triboelectric effect. An assembled nanogenerator of an area of 8 cm2 and a thickness of 80 μm could generate an electrical output voltage of 1.1 V and a current of 1.4 μA under the bending strain. The piezoelectric voltage depended on the thickness of the PZT textile, whereas the piezoelectric current depended on both the thickness and the area of the PZT textile. The electrical performance of the device was significantly affected by the orientation of the PZT fiber and the bending direction. The output voltage and the output current were strain-dependent, whereas the total integrated charge was independent of the strain rate. The properties of the flexible nanogenerator could be quantified to verify the pure piezoelectric performance of the device

Expectation of Rejection and Its Association with Health Care Avoidance and Delay Among 2175 Korean Lesbian, Gay, and Bisexual Adults: A Nationwide Cross-Sectional Survey

© Copyright 2022, Mary Ann Liebert, Inc., publishers 2022.Purpose: The study examined an association between expectation of rejection and health care avoidance and delay (HAD) among lesbian, gay, and bisexual (LGB) adults in South Korea. Methods: We analyzed data from a nationwide cross-sectional survey of 2175 South Korean LGB adults, which was approved by the Korea University Institutional Review Board. We categorized expectation of rejection into tertiles ("low,""medium,"and "high"levels) and investigated its association with past 12-month HAD using multivariate modified Poisson regression. Results: After adjusting for covariates, including experiences of discrimination, participants with high levels of expectation of rejection had 1.38-times (95% confidence interval: 1.16-1.65) higher prevalence of HAD compared with those with low levels. Conclusion: Living in anticipation of rejection can negatively impact LGB adults' health care utilization.N

The evaluation of energy saving performance for the modular design centrifugal chiller

The modular concept design and operation of a centrifugal chiller offers the potential of increased cycle efficiency both at full load and off load conditions compared to the single compressor chiller. Modular chiller design is that a smaller, individual chiller can be connected with another, to make a larger capacity system. In the case of a tandem chiller, there would be faced to the higher initial cost or bigger foot print than a single compressor chiller at the same capacity because manufacturing cost, weight and size will be decreased according to increase of the refrigeration capacity. Therefore, it is obvious that a modular chiller have to be improved its efficiency first by both the operation algorithm and major cycle components. Eventually, the efficiency of the modular chiller achieves up to 6% at the full load condition after added series counter flow effect as much as 3% and more 3% added by improved aerodynamic design for impeller. Moreover, maximize off design potential through the capacity combination algorithm as the way of uneven loading makes 24% improved based on AHRI 550/590