Liquid Crystalline Systems from Nature and Interaction of Living Organisms with Liquid Crystals.

Biomaterials, which are substances interacting with biological systems, have been extensively explored to understand living organisms and obtain scientific inspiration (such as biomimetics). However, many aspects of biomaterials have yet to be fully understood. Because liquid crystalline phases are ubiquitously found in biomaterials (e.g., cholesterol, amphiphile, DNA, cellulose, bacteria), therefore, a wide range of research has made attempts to approach unresolved issues with the concept of liquid crystals (LCs). This review presents these studies that address the interactive correlation between biomaterials and LCs. Specifically, intrinsic LC behavior of various biomaterials such as DNA, cellulose nanocrystals, and bacteriaare first introduced. Second, the dynamics of bacteria in LC media are addressed, with focus on how bacteria interact with LCs, and how dynamics of bacteria can be controlled by exploiting the characteristics of LCs. Lastly, how the strong correlation between LCs and biomaterials has been leveraged to design a new class of biosensors with additional functionalities (e.g., self-regulated drug release) that are not available in previous systems is reviewed. Examples addressed in this review convey the message that the intersection between biomaterials and LCs offers deep insights into fundamental understanding of biomaterials, and provides resources for development of transformative technologies.

Effect of Gravity and Various Operating Conditions on Proton Exchange Membrane Water Electrolysis Cell Performance.

Water electrolysis is an eco-friendly method for the utilization of renewable energy sources which provide intermittent power supply. Proton exchange membrane water electrolysis (PEMWE) has a high efficiency in this regard. However, the two-phase flow of water and oxygen at the anode side causes performance degradation, and various operating conditions affect the performance of PEMWE. In this study, the effects of four control parameters (operating temperature, flow rate, cell orientation, and pattern of the channel) on the performance of PEMWE were investigated. The effects of the operating conditions on its performance were examined using a 25 cm2 single-cell. Evaluation tests were conducted using in situ methods such as polarization curves and electrochemical impedance spectroscopy. The results demonstrated that a high operating temperature and low flow rate reduce the activation and ohmic losses, and thereby enhance the performance of PEMWE. Additionally, the cell orientation affects the performance of PEMWE owing to the variation in the two-phase flow regime. It was observed that the slope of specific sections in the polarization curve rapidly increases at a specific cell voltage.

Eating disorder symptomatology in transgender patients: Differences across gender identity and gender affirmation.

OBJECTIVE: Past studies have reported high rates of eating disorder (ED) symptomatology among transgender people, yet without consideration of gender affirmation. The primary objective of this study was to evaluate the relationship between gender identity, gender affirming interventions such as gender affirming hormones (GAH) and gender affirming surgeries (GAS), and ED symptomatology. METHOD: Transgender patients at a primary care outpatient gender health program in the United States completed a survey consisting of demographics, medical history, and clinical variables, including the Eating Disorder Examination Questionnaire (EDE-Q). Multivariate analyses of covariance were conducted to compare EDE-Q scores across gender identity and gender affirmation. RESULTS: Compared to transgender men (n = 79), transgender women (n = 87) reported higher EDE-Q scores and significantly higher Eating Concern. Compared to hormone/surgery-naïve and hormone-experienced/surgery-naïve patients, hormone/surgery-experienced patients had lower EDE-Q scores. Hormone/surgery-experienced patients reported significantly lower Shape Concern and marginally lower Global Score and Weight Concern than hormone-experienced/surgery-naïve patients. There were no differences in EDE-Q scores between hormone/surgery-naïve and hormone-experienced/surgery-naïve patients. DISCUSSION: Transgender patients report high levels of ED symptomatology. There are subtle, yet important, differences in ED between gender identities and gender affirmations. High ED prevalence may result from the dual pathways of sociocultural pressures as well as gender dysphoria. Both GAH and GAS may be effective interventions to support gender affirmation and thereby alleviate ED symptomatology. While the potential positive benefits of GAS on ED are more apparent, the effects of GAH are less clear.

[A case of gallbladder tuberculosis diagnosed by positive tuberculosis-polymerase chain reaction].

Gallbladder tuberculosis is an extremely rare disease that is rarely reported in the literature. Arriving at the correct diagnosis of gallbladder tuberculosis is difficult, and it is usually made by histopathologic examination after cholecystectomy. However, due to the low sensitivity of acid-fast stain and culture result, diagnosing gallbladder tuberculosis is still demanding even after tissue acquisition. To overcome this problem, tuberculosis-polymerase chain reaction (TB-PCR) is performed on the resected specimen, which has high sensitivity and specificity. A 70-year-old female who had previously undergone total gastrectomy for advanced gastric cancer was admitted with right upper quadrant pain. Abdominal ultrasonography and computed tomography revealed acute cholecystitis without gallstones or sludge. She underwent cholecystectomy and the histopathologic finding of the specimen showed chronic active cholecystitis without gallstones or sludge. Because she was suspected to have pulmonary tuberculosis, TB-PCR was also performed on the resected gallbladder. TB-PCR showed positive reaction for Mycobacterium tuberculosis and we could diagnose it as gallbladder tuberculosis. Herein, we present a case of gallbladder tuberculosis diagnosed by TB-PCR from resected gallbladder.

Increased alternative lengthening of telomere phenotypes of telomerase-negative immortal cells upon trichostatin--a treatment.

Human immortal cells maintain their telomeres either by telomerase or by alternative lengthening of telomeres (ALT) that is based on homologous telomeric recombination. Previous studies showed that the ALT mechanism is activated in non-ALT cells when heterochromatic features are reduced. In this study, we examined the ALT phenotypes of ALT cells after treatment with trichostatin-A (TSA), which is an inhibitor of histone deacetylases and causes global chromatin decondensation. The ALT cells remained telomerase-negative after TSA treatment. ALT-associated promyelocytic leukemia (PML) nuclear bodies and telomere sister chromatid exchanges, typical ALT phenotypes, markedly increased in the TSA-treated cells, while the telomere length remained unchanged. In addition, telomerase expression in the ALT cells suppressed TSA-mediated ALT phenotype enhancement. Our results show that certain ALT phenotypes become more pronounced when chromatin is decondensed, and also suggest that the ALT mechanism may compete with telomerase for telomere maintenance in cells that lack heterochromatin.

Identification of cdc25 gene in pinewood nematode, Bursaphelenchus xylophilus, and its function in reproduction.

The cdc25 gene, which is highly conserved in many eukaryotes, encodes a phosphatase that plays essential roles in cell cycle regulation. We identified a cdc25 ortholog in the pinewood nematode, Bursaphelenchus xylophilus. The B. xylophilus ortholog (Bx-cdc25) was found to be highly similar to Caenorhabditis elegans cdc-25.2 in sequence as well as in gene structure, both having long intron 1. The Bx-cdc25 gene was determined to be composed of seven exons and six introns in a 2,580 bp region, and was shown to encode 360 amino acids of a protein containing a highly-conserved phosphatase domain. Bx-cdc25 mRNA was hardly detectable throughout the juvenile stages but was highly expressed in eggs and in both female and male adults. Functional conservation during germline development between C. elegans cdc25 and Bx-cdc25 was revealed by Bx-cdc25 RNA interference in C. elegans.