Electric-Field-Driven Trion Drift and Funneling in MoSe2 Monolayer.

Excitons, electron-hole pairs in semiconductors, can be utilized as information carriers with a spin or valley degree of freedom. However, manipulation of excitons' motion is challenging because of their charge-neutral characteristic and short recombination lifetimes. Here we demonstrate electric-field-driven drift and funneling of charged excitons (i.e., trions) toward the center of a MoSe2 monolayer. Using a simple bottom-gate device, we control the electric fields in the vicinity of the suspended monolayer, which increases the trion density and pulls down the layer. We observe that locally excited trions are subjected to electric force and, consequently, drift toward the center of the stretched layer. The exerting electric force on the trion is estimated to be 102-104 times stronger than the strain-induced force in the stretched monolayer, leading to the successful observation of trion drift under continuous-wave excitation. Our findings provide a new route for manipulating trions and achieving new types of optoelectronic devices.

Direct Observation of Self-Hybridized Exciton-Polaritons and Their Valley Polarizations in a Bare WS2 Layer.

The strong excitonic properties of transition metal dichalcogenides (TMD) have led to the successful demonstration of exciton-polaritons (EPs) in various optical cavity structures. Recently, self-hybridized EPs have been discovered in a bare TMD layer, but experimental investigation is still lacking because of their nonradiative nature. Herein, the direct observation of self-hybridized EPs in a bare multilayer WS2 via the evanescent field coupling technique is reported. Because of the thickness-dependent Rabi splitting energy, the dispersion curves of the EPs change sensitively with sample thickness. Moreover, continuous tuning of EP dispersion curves is demonstrated by controlling the excitation laser power. Lastly, it is observed that guided EPs retain valley polarization up to 0.2 at room temperature, representing a valley-preserved strong coupling regime. It is believed that the high tunability and valley polarization properties of the guided EPs in bare TMD layers can facilitate new nanophotonic and valleytronic applications.

Development of an endometriosis self-assessment tool for patient.

OBJECTIVE: This study aimed to develop and verify an endometriosis self-assessment tool (ESAT). METHODS: A non-experimental, descriptive, correlational study design was used. Candidate items were developed based on a conceptual framework constructed using the results of in-depth interviews and an integrative literature review. The construct validity of the developed tool was also examined. One-hundred and forty-two participants (117 patients with endometriosis and 25 patients without endometriosis) were included in the validity and reliability tests. The data were collected between August and December 2018. Nomological validity was verified based on significant correlations between the ESAT and the quality-of-life scores. RESULTS: A 21-item ESAT was developed, and its construct validity was supported. Exploratory factor analysis indicated that the tool consisted of four components (gastrointestinal symptoms, dysmenorrhea, usual symptoms, and the amount and characteristics of menstrual bleeding) with a variance of 61.6%. The variance in quality-of-life scores, as explained by the ESAT scores, was relatively high. Receiver operator characteristics curve analysis indicated that ESAT scores significantly differentiated endometriosis from non-endometriosis with fair discriminatory power at a cut-off score of 50 (sensitivity, 0.76; specificity, 0.72; area under the curve, >0.75; P<0.001). This means that patients with ESAT scores >50 points were more likely to have endometriosis. Thus, the reliability of the ESAT was confirmed. CONCLUSION: The devised tool appears valid and reliable. This tool may allow women to determine their risk of endometriosis by distinguishing between normal and pathological menstruation-related symptoms.

Estimated Prevalence and Incidence of Uterine Leiomyoma, and Its Treatment Trend in South Korean Women for 12 years: A National Population-Based Study.

Background: Although uterine leiomyoma causes many problems, including infertility, there are few studies that have investigated the epidemiologic characteristics of uterine leiomyoma in South Korea. The aim of this study is to estimate the prevalence and incidence of uterine leiomyoma in South Korea and analyze the treatment trends. Materials and Methods: Women of reproductive age (15-54 years) were selected from the Korean National Health Insurance Service (NHIS) sample cohort dataset, which was collected from 2002 to 2013. Patients with uterine leiomyoma were identified by ICD-10 (International Codes of Disease, 10th Edition) and intervention codes. Prevalence and incidence were calculated from the NHIS cohort dataset and the treatment trends were analyzed for diagnosed patients. Results: The prevalence in overall age groups increased from 0.96% in 2002 to 2.43% in 2013, and the 1-year incidences of all age groups increased. The 26-30 age group showed the highest rate of 1-year incidence increase (2.14-folds, 0.33% in 2003 to 0.70% in 2013). The proportion of myomectomy increased from 22% in 2002 to 49% in 2013, whereas the proportion of hysterectomy decreased from 78% to 45%. Conclusions: The prevalence and incidence of uterine leiomyoma are increasing in South Korea as time progresses, and the rate of incidence increase is higher in younger reproductive women. Overall trends in uterine leiomyoma treatment are shifting to the methods of the saving uterus.

The Estimated Prevalence and Incidence of Endometriosis With the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC): A National Population-Based Study.

BACKGROUND: The incidence and prevalence of endometriosis remain unclear due to diagnostic difficulties. Especially, there has been little information regarding the population-based epidemiology of endometriosis. The purpose of this study is to estimate the prevalence and incidence of endometriosis in Korea based on the health insurance claims data. METHODS: This study is a retrospective cohort study using the Korean National Health Insurance Service-National Sample Cohort, which correspond to approximately 1 million Korean populations from 2002 to 2013. Patients aged 15-54 years were selected, and the prevalence and incidence of endometriosis were estimated by time and age groups. RESULTS: The age-adjusted prevalence rate of endometriosis also increased from 2.12 per 1,000 persons (95% confidence interval [CI], 2.01-2.24) in 2002 to 3.56 per 1,000 persons (95% CI, 3.40-3.71) in 2013. The average adjusted incidence showed no statistically significant increase. However, the age-specific incidence of the 15-19 and 20-24 years age groups increased significantly from 0.24 and 1.29 per 1,000 persons in 2003 to 2.73 and 2.71 per 1,000 persons in 2013 (R2 = 0.93 and 0.77, P < 0.001), while the incidence rate of the age group 40-44 and 45-49 years decreased from 2.36 and 1.72 per 1,000 persons in 2003 to 0.81 and 0.27 per 1,000 persons in 2013 (R2 = 0.83 and 0.89, P < 0.001). CONCLUSION: The prevalence and incidence of endometriosis in Korean women were lower than that of previous reports in high-risk population studies. Furthermore, we found a significant increase in the diagnosis of endometriosis in younger age groups.

Non-absorbable versus absorbable sutures for anterior colporrhaphy: study protocol for a randomised controlled trial in South Korea.

INTRODUCTION: The anterior vaginal wall is the segment most commonly affected by prolapse. Traditionally, anterior vaginal wall prolapse is repaired via anterior colporrhaphy, which is known to have a high recurrence rate. Several factors might affect the outcome of anterior colporrhaphy, and the use of absorbable sutures might also be associated with the high recurrence rate because the sutures might not be able to retain adequate strength until the plicated pubocervical fascia remodels and regains maximum tensile strength. Nonetheless, no comparative data exist about the relative efficacy and safety of anterior colporrhaphy using non-absorbable versus absorbable sutures. The objective of this study is to compare the surgical outcomes of anterior colporrhaphy using non-absorbable sutures with those of anterior colporrhaphy using absorbable sutures. METHODS AND ANALYSIS: This is a randomised, multicentre, superiority trial. Anterior colporrhaphy will be performed in a traditional manner with midline plication of the fibromuscular layer using either non-absorbable or absorbable sutures. The primary outcome is composite surgical success 1 year after surgery defined as the absence of all of the following: (1) anterior vaginal descent beyond the hymen, (2) the presence of vaginal bulge symptoms and (3) retreatment for recurrent anterior vaginal wall prolapse with either surgery or pessary. The secondary outcomes include the individual components of the composite primary end point, anatomical outcomes, condition-specific quality of life and adverse events related to anterior colporrhaphy. The planned number of participants is 192. ETHICS AND DISSEMINATION: This study was approved by the Institutional Review Board of Seoul National University Hospital (H-1810-037-977). The results of the study will be published in peer-reviewed journals, and the findings will be presented at scientific meetings. TRIAL REGISTRATION NUMBER: NCT03736811.

The effect of the look-back period for estimating incidence using administrative data.

BACKGROUND: The look-back period is needed to define baseline population for estimating incidence. However, short look-back period is known to overestimate incidence of diseases misclassifying prevalent cases to incident cases. The purpose of this study is to evaluate the impact of the various length of look-back period on the observed incidences of uterine leiomyoma, endometriosis and adenomyosis, and to estimate true incidences considering the misclassification errors in the longitudinal administrative data in Korea. METHODS: A total of 319,608 women between 15 to 54 years of age in 2002 were selected from Korea National Health Insurance Services (KNHIS) cohort database. In order to minimize misclassification bias incurred when applying various length of look-back period, we used 11 years of claim data to estimate the incidence by equally setting the look-back period to 11 years for each year using prediction model. The association between the year of diagnosis and the number of prevalent cases with the misclassification rates by each look-back period was investigated. Based on the findings, prediction models on the proportion of misclassified incident cases were developed using multiple linear regression. RESULTS: The proportion of misclassified incident cases of uterine leiomyoma, endometriosis and adenomyosis were 32.8, 10.4 and 13.6% respectively for the one-year look-back period in 2003. These numbers decreased to 6.3% in uterine leiomyoma and - 0.8% in both endometriosis and adenomyosis using all available look-back periods (11 years) in 2013. CONCLUSION: This study demonstrates approaches for estimating incidences considering the different proportion of misclassified cases for various length of look-back period. Although the prediction model used for estimation showed strong R-squared values, follow-up studies are required for validation of the study results.

Preoperative POPQ versus Simulated Apical Support as a Guideline for Anterior or Posterior Repair at the Time of Transvaginal Apical Suspension (PREPARE trial): study protocol for a randomised controlled trial.

INTRODUCTION: Transvaginal reconstructive surgery is the mainstay of treatment for symptomatic pelvic organ prolapse. Although adequate support for the vaginal apex is considered essential for durable surgical repair, the optimal management of anterior and posterior vaginal wall prolapse in women undergoing transvaginal apical suspension remains unclear. The objective of this trial is to compare surgical outcomes of pelvic organ prolapse quantification (POPQ)-based surgery with outcomes of simulated apical support-based surgery for anterior or posterior vaginal wall prolapse at the time of transvaginal apical suspension. METHODS AND ANALYSIS: This is a randomised, multicentre, non-inferiority trial. While women who are assigned to the POPQ-based surgery group will undergo anterior or posterior colporrhaphy for all stage 2 or greater anterior or posterior vaginal prolapse, those assigned to simulated apical support-based surgery will receive anterior or posterior colporrhaphy only for the prolapse unresolved under simulated apical support. The primary outcome measure is the composite surgical success, defined as the absence of anatomical (anterior or posterior vaginal descent beyond the hymen or descent of the vaginal apex beyond the half-way point of vagina) or symptomatic (the presence of vaginal bulge symptoms) recurrence or retreatment for prolapse by either surgery or pessary, at 2 years after surgery. Secondary outcomes include the rates of anterior or posterior colporrhaphy, the changes in anatomical outcomes, condition-specific quality of life and sexual function, perioperative outcomes and adverse events. ETHICS AND DISSEMINATION: This study was approved by the institutional review board of each participating centre (Seoul National University College of Medicine/Seoul National University Hospital, Chonnam National University Hospital, Seoul St. Mary's Hospital, International St. Mary's Hospital). The results of the study will be published in peer-reviewed journals, and the findings will be presented at scientific meetings. TRIAL REGISTRATION NUMBER: NCT03187054.

The Effect of Perioperative Intravenous Iron on Hemoglobin in Surgical Patients: A Meta-Analysis.

BACKGROUND: Patient blood management aims to maintain hemoglobin level, minimize blood loss, and avoid unnecessary blood transfusion. Ferric carboxymaltose, an intravenous iron agent, was included as a part of surgical patient blood management strategy. However, it is still controversial that ferric carboxymaltose can reduce transfusion requirements. The purpose of this systematic review and meta-analysis is to evaluate the benefits of perioperative ferric carboxymaltose on the postoperative hematological parameters and transfusion requirements. METHODS: Randomized controlled trials evaluating the effects of ferric carboxymaltose were searched through databases: MEDLINE, EMBASE, CENTRAL, CINAHL, Scopus, Web of Science, and KoreaMed. Meta-analysis was performed using random effect models. RESULTS: A total of 8 studies (n = 471) were included in the final analysis. Postoperative hemoglobin was higher in the ferric carboxymaltose group than in the control group (mean difference [MD], 0.58 g/dL; 95% confidence interval [CI], 0.36 to 0.80; P < 0.00001). Postoperative serum ferritin and transferrin saturation were also higher in the ferric carboxymaltose group (MD, 373.85 µg/L; 95% CI, 298.13 to 449.56; P < 0.00001; MD, 10.35%; 95% CI, 4.59 to 16.10; P < 0.00001, respectively). However, there were no significant differences in the number of transfused patients, length of hospital stay, and adverse events between groups. Subgroup analysis revealed that adverse events were lower in the ferric carboxymaltose group than the oral iron group. CONCLUSIONS: This study supports that ferric carboxymaltose may increase the postoperative hemoglobin level in surgical patients. However, transfusion requirements could not be reduced by ferric carboxymaltose. Optimal dose and time should be further analyzed.

Discovery of a small molecule RXFP3/4 agonist that increases food intake in rats upon acute central administration.

The relaxin family peptide receptors have been implicated in numerous physiological processes including energy homeostasis, cardiac function, wound healing, and reproductive function. Two family members, RXFP3 and RXFP4, are class A GPCRs with endogenous peptide ligands (relaxin-3 and insulin-like peptide 5 (INSL5), respectively). Polymorphisms in relaxin-3 and RXFP3 have been associated with obesity, diabetes, and hypercholesterolemia. Moreover, central administration of relaxin-3 in rats has been shown to increase food intake, leading to body weight gain. Reported RXFP3 and RXFP4 ligands have been restricted to peptides (both endogenous and synthetic) as well as a low molecular weight positive allosteric modulator requiring a non-endogenous orthosteric ligand. Described here is the discovery of the first potent low molecular weight dual agonists of RXFP3/4. The scaffold identified is competitive with a chimeric relaxin-3/INSL5 peptide for RXFP3 binding, elicits similar downstream signaling as relaxin-3, and increases food intake in rats following acute central administration. This is the first report of small molecule RXFP3/4 agonism.

Successfully removed uterine angioleiomyoma by robot-assisted laparoscopic myomectomy.

Angioleiomyoma is a rare type of leiomyoma variant and there are a few cases reported to date. Herein, we present a case of angioleiomyoma in a 36-year-old woman with lower abdominal pain, initially diagnosed by degenerated uterine leiomyoma. The transvaginal ultrasonogram showed an ovoid-shaped heterogeneously hyperechoic lesion in left cornual site of uterus and pelvic magnetic resonance image showed an about 5.1 cm sized heterogenous T2 intermediate high mass with poor enhancement. The patient underwent a robot-assisted laparoscopic myomectomy, and final histopathologic diagnosis revealed uterine angioleiomyoma. This case is the first case of angioleiomyoma resected by robotic surgery. The patient is on follow up for over 1 year and shows no evidence of recurrence until now.

Analysis of MED12 Mutation in Multiple Uterine Leiomyomas in South Korean patients.

Uterine leiomyomas are one of the most common benign gynecologic tumors, but the exact causes are not completely understood. In 2011, through DNA sequencing, MED12 mutation was discovered in approximately 71% of uterine leiomyomas. Several recent studies confirmed the high frequency of MED12 mutation in uterine leiomyoma. Nevertheless, no study has been done on MED12 mutation in the case of patients with multiple leiomyomas in a patient. The purpose of this study was to investigate the frequency of MED12 mutations in uterine leiomyomas of South Korean patients. In addition, we examined MED12 mutation in multiple leiomyomas in the same patients. Uterine leiomyoma tissues were obtained from symptomatic women who underwent hysterectomy or myomectomy for medically indicated reasons. We collected 60 uterine leiomyomas from 41 women. Tumor size ranged from 1 to 12cm. Patients' ages ranged from 25 to 55 years with an average of 38.4 years. Of the 60 tumors, 40 (66.67%) displayed MED12 mutation. Among the 41 patients, 14 patients had multiple leiomyomas and we analyzed those multiple leiomyomas. Three of them had the same mutations. Five of them, each leiomyoma had a different mutation. Two of them did not have mutation. Four of them had both mutation-positive and mutation-negative leiomyomas. In conclusion, we confirmed the high frequency of the MED12 mutation in uterine leiomyomas of South Korean patients. We also identified various MED12 mutation status in patients with multiple leiomyomas. This suggests that in a given patient, different tumors may have arisen from different cell origins and therefore it is supposed that occurrence of multiple leiomyoma in a single patient may not be caused by intrauterine metastasis or dissemination.

Is robot-assisted laparoscopic myomectomy limited in multiple myomas?: a feasibility for ten or more myomas.

OBJECTIVE: To evaluate the feasibility of robot-assisted laparoscopic myomectomy in multiple myomas over 10. METHODS: A retrospective study was conducted for 662 patients who underwent robot-assisted laparoscopic myomectomy and open myomectomy by a single operator in a tertiary university hospital. RESULTS: A total of 30 women underwent removal of 10 or more uterine myomas by robotics and 13 patients were selected for this study. The average number of myomas removed was 13.7 (range 10-20). The maximum diameter of the myomas was 6.8 cm (range 5.0-10.0 cm). The sum of the diameters of each myoma was 34.7 cm (range 20.0-54.5 cm) and the mass of resected myomas for each case was 229.1 g (range 106.8-437.9 g). In no case was the robotic procedure converted into conventional laparoscopy or laparotomy, and all patients recovered without any major complications. In comparison with 13 cases of open myomectomy during the same period, robotic surgery took longer time than open surgery (360.5 vs. 183.8 minutes; P=0.001) but had shorter postoperative hospital days after surgery (mean 2.5 vs. 3.5 days; P=0.003). CONCLUSION: Robot-assisted laparoscopic myomectomy could be an alternative to laparotomic myomectomy for numerous myomas over 10 in number.

Three cases of complications after high-intensity focused ultrasound treatment in unmarried women.

High-intensity focused ultrasound (HIFU) has been regarded as a non-surgical, minimally invasive therapeutic option for patients who prioritize uterus-conservation. Although many studies have shown that HIFU therapy is a safe and effective treatment of uterine fibroid, not all fibroids are suitable for HIFU due to risks of serious complications. We experienced three cases of complications after the HIFU ablation for huge uterine fibroids, including two cases of rapid myoma enlargement and one case of heavy vaginal bleeding.

Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p < 0.01), but there was also a significant linear relationship between static and dynamic removal (p < 0.05). Accounting for contact time of CNTs with NOM during filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration.

Competitive, immunometric assay for fusion protein quantification: protein production prioritization.

Effective drug discovery demands the availability of microgram to gram quantities of high-quality protein encoded by novel transcripts. Protein expression vectors designed for large-scale protein production often include one or more specific tags to such transcripts, to simplify the purification of the targeted protein. Optimization of the complex expression and purification process requires the evaluation of multiple expression candidate clones to identify a production-suitable construct in terms of quality and final protein yield. Efficiency of the entire expression screening process is typically assessed by direct visualization of the banding patterns from whole-cell lysates on SDS-PAGE gels, by direct staining and/or immunoblotting, using antibodies against the tag or the protein of interest. These techniques, generally run under denaturing conditions, have proven to be only marginally predictive of the purification yield and authentic folding for native proteins. Small-scale, multiparallel affinity purification followed by SDS-PAGE analysis is more predictive for expression screening; however, this approach is labor intensive and time consuming. Here we describe the development of an alternative expression efficiency assessment technique, designed to evaluate the accessibility of affinity tags expressed with the desired fusion proteins, using acoustic membrane microparticle assay technology on the ViBE protein analysis workstation.

Nano zero-valent iron impregnated on titanium dioxide nanotube array film for both oxidation and reduction of methyl orange.

Here, we demonstrated that nano zero-valent iron (nZVI) impregnated onto self-organized TiO(2) nanotube thin films exhibits both oxidation and reduction capacities in addition to the possible electron transfer from TiO(2) to nZVI. The TiO(2) nanotubes were synthesized by anodization of titanium foil in a two-electrode system. Amorphous TiO(2) (amTiO(2)) nanotubes were annealed at 450 °C for 1 h to produce crystalline TiO(2) (crTiO(2)) nanotubes. The nZVI particles were immobilized on the TiO(2) array film by direct borohydride reduction. Field emission scanning electron microscopy (FE-SEM) analysis of the crystalline TiO(2) nanotube with nZVI (nZVI/crTiO(2)) indicated that the nZVI particles with a mean particle diameter of 28.38 ± 11.81 nm were uniformly distributed onto entire crTiO(2) nanotube surface with a mean pore diameter of 75.24 ± 17.66 nm and a mean length of 40.07 µm. Environmental applicability of our proposed nZVI/TiO(2) nanotube thin films was tested for methyl orange (MO) degradation in the aqueous system with and without oxygen. Since oxygen could facilitate the nZVI oxidation and inhibit electron transfer from crTiO(2) to nZVI surface, MO degradation by nZVI/crTiO(2) in the presence of oxygen was significantly suppressed whereas nZVI/crTiO(2) in the absence of oxygen enhanced MO degradation. MO degradation rate by each sample without oxygen were in following order: nZVI/crTiO(2) (k(obs) = 0.311 min(-1)) > nZVI/amTiO(2) (k(obs) = 0.164 min(-1)) > crTiO(2) (k(obs) = 0.068 min(-1)). This result can be explained with a synergistic effect of the significant reduction by highly-dispersed nZVI particles on TiO(2) nanotubes as well as the electron transfer from the conduction band of crTiO(2) to the nZVI on the crTiO(2) for the degradation of MO.

Characteristics of metabolically obese, normal-weight women differ by menopause status: the Fourth Korea National Health and Nutrition Examination Survey.

OBJECTIVE: People with metabolically obese, normal-weight (MONW) phenotype, characterized by insulin resistance, are vulnerable to cardiovascular disease even though they are not physically obese. We assessed whether the characteristics of the MONW phenotype differed by menopause status in Korean women. METHODS: A nationally representative sample of 1,736 Korean women aged 19 years or older (1,197 premenopausal women and 539 postmenopausal women), without diabetes, and with a body mass index of 18.5 to less than 25 kg/m were randomly selected from the Fourth Korean National Health and Nutrition Examination Survey in 2008. MONW individuals were defined as those included in the highest quartile of a homeostatic model assessment of insulin resistance. RESULTS: The prevalence of the MONW phenotype was highest (23.8%) in young women (<30 y) and decreased with age in premenopausal women. In postmenopausal women, there was a sharp increase in the prevalence of the MONW phenotype after the age of 60 years. After adjustment for covariates, including age, we found that young age, rural residence, high body mass index, high systolic blood pressure, low high-density lipoprotein cholesterol, high white blood cell count, and lack of regular exercise were significantly associated with the MONW phenotype in premenopausal women. However, for postmenopausal women, alanine aminotransferase was the only predictor that was independently associated with the MONW phenotype. CONCLUSIONS: The characteristics of the MONW phenotype seem to vary between premenopausal and postmenopausal women. This suggests that optimal clinical approaches to preventing cardiovascular disease in women with the MONW phenotype may differ according to menopause status.