CT-guided pretreatment biopsy diagnosis in patients with thymic epithelial tumours: diagnostic accuracy and risk of seeding

AIM

To investigate the diagnostic performance of computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) for thymic epithelial tumours (TETs) and the complication rate after PTNB including seeding after PTNB.

MATERIALS AND METHODS

This retrospective study identified PTNBs for anterior mediastinal lesions between May 2007 and September 2021. The diagnostic performance for TETs and complications were investigated. The concordance of the histological grades of TETs between PTNB and surgery was evaluated. The factors associated with pleural seeding after PTNB were determined using Cox regression analysis.

RESULTS

Of 387 PTNBs, 235 PTNBs from 225 patients diagnosed as TETs (124 thymomas and 101 thymic carcinomas) and 150 PTNBs from 133 patients diagnosed as other than TETs were included. The sensitivity, specificity, and accuracy for TETs were 89.4% (210/235), 100% (210/210), and 93.5% (360/385), respectively, with an immediate complication rate of 4.4% (17/385). The concordance rate of the histological grades between PTNB and surgery was 73.3% (77/105) after excluding uncategorised types of thymomas. During follow-up after PTNB (median duration, 38.8 months; range, 0.3-164.6 months), no tract seeding was observed. Pleural seeding was observed in 26 patients. Thymic carcinoma (hazard ratio [HR], 5.94; 95% confidence interval [CI], 2.07-17.08; p=0.001) and incomplete resection (HR, 3.29; 95% CI, 1.20-9.02; p=0.02) were associated with pleural seeding, while the biopsy approach type (transpleural versus parasternal) was not associated (p=0.12).

CONCLUSIONS

Pretreatment biopsy for TETs was accurate and safe and may be considered for diagnosing TETs, particularly when the diagnosis is challenging and histological diagnosis is mandatory.

Predictability of the emergency department triage system during the COVID-19 pandemic

Background

Emergency department (ED) triage systems are used to classify the severity and urgency of emergency patients, and Korean medical institutions use the Korean Triage and Acuity Scale (KTAS). During the coronavirus disease 2019 (COVID-19) pandemic, appropriate treatment for emergency patients was delayed due to various circumstances, such as overcrowding of EDs, lack of medical workforce resources, and increased workload on medical staff. The purpose of this study was to evaluate the accuracy of the KTAS in predicting the urgency of emergency patients during the COVID-19 pandemic.

Methods

This study retrospectively reviewed patients who were treated in the ED during the pandemic period from January 2020 to June 2021. Patients were divided into COVID-19 screening-negative (SN group) and COVID-19 screening-positive (SP group) groups. We compared the predictability of the KTAS for urgent patients between the two groups.

Results

Of 107,480 patients, the SN and SP groups included 62,776 (58.4%) and 44,704 (41.6%) patients, respectively. The odds ratios for severity variables at each KTAS level revealed a more evident discriminatory power of KTAS for severity variables in the SN group (p-value <0.001). The predictability of KTAS for severity variables was higher in the SN group than in the SP group (area under the curve, p-value <0.001).

Conclusion

During the pandemic, the KTAS had low accuracy in predicting patients in critical conditions in the ED. Therefore, in future pandemic periods, supplementation of the current ED triage system should be considered in order to accurately classify the severity of patients.

Partial separability and functional graphical models for multivariate Gaussian processes

The covariance structure of multivariate functional data can be highly complex, especially if the multivariate dimension is large, making extensions of statistical methods for standard multivariate data to the functional data setting challenging. For example, Gaussian graphical models have recently been extended to the setting of multivariate functional data by applying multivariate methods to the coefficients of truncated basis expansions. However, compared with multivariate data, a key difficulty is that the covariance operator is compact and thus not invertible. This paper addresses the general problem of covariance modelling for multivariate functional data, and functional Gaussian graphical models in particular. As a first step, a new notion of separability for the covariance operator of multivariate functional data is proposed, termed partial separability, leading to a novel Karhunen–Loève-type expansion for such data. Next, the partial separability structure is shown to be particularly useful in providing a well-defined functional Gaussian graphical model that can be identified with a sequence of finite-dimensional graphical models, each of identical fixed dimension. This motivates a simple and efficient estimation procedure through application of the joint graphical lasso. Empirical performance of the proposed method for graphical model estimation is assessed through simulation and analysis of functional brain connectivity during a motor task.

A randomized phase III trial comparing adjuvant single-agent S1, S-1 with oxaliplatin, and postoperative chemoradiation with S-1 and oxaliplatin in patients with node-positive gastric cancer after D2 resection: the ARTIST 2 trial☆

BACKGROUND

Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC.

PATIENTS AND METHODS

The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m² every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146).

RESULTS

A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable.

CONCLUSIONS

In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.

Single-Base Genome Editing in Corynebacterium glutamicum with the Help of Negative Selection by Target-Mismatched CRISPR/Cpf1

CRISPR/Cpf1 has emerged as a new CRISPR-based genome editing tool because, in comparison with CRIPSR/Cas9, it has a different T-rich PAM sequence to expand the target DNA sequence. Single-base editing in the microbial genome can be facilitated by oligonucleotide-directed mutagenesis (ODM) followed by negative selection with the CRISPR/Cpf1 system. However, single point mutations aided by Cpf1 negative selection have been rarely reported in Corynebacterium glutamicum. This study aimed to introduce an amber stop codon in crtEb encoding lycopene hydratase, through ODM and Cpf1-mediated negative selection; deficiency of this enzyme causes pink coloration due to lycopene accumulation in C. glutamicum. Consequently, on using double-, triple-, and quadruple-basemutagenic oligonucleotides, 91.5-95.3% pink cells were obtained among the total live C. glutamicum cells. However, among the negatively selected live cells, 0.6% pink cells were obtained using single-base-mutagenic oligonucleotides, indicating that very few single-base mutations were introduced, possibly owing to mismatch tolerance. This led to the consideration of various targetmismatched crRNAs to prevent the death of single-base-edited cells. Consequently, we obtained 99.7% pink colonies after CRISPR/Cpf1-mediated negative selection using an appropriate singlemismatched crRNA. Furthermore, Sanger sequencing revealed that single-base mutations were successfully edited in the 99.7% of pink cells, while only two of nine among 0.6% of pink cells were correctly edited. The results indicate that the target-mismatched Cpf1 negative selection can assist in efficient and accurate single-base genome editing methods in C. glutamicum.

Combined effects of dietary zinc at 3 years of age and obesity at 7 years of age on the serum uric acid levels of Korean children

BACKGROUND/OBJECTIVES

To assess the longitudinal associations of the antioxidant capacity of zinc and body mass index (BMI) with serum uric acid (SUA) in South Korean children.

SUBJECTS/METHODS

Using follow-up data from the Ewha Birth and Growth Cohort, we included subjects who were seen at 3 and 7 years of age (n = 183; 90 boys, 93 girls). Daily zinc intake and BMI were assessed at 3 and 7 years of age. SUA measured at 7 years was used as the outcome variable. Using a general linear model, the effects of dietary zinc intake and BMI on SUA were assessed. We also assessed the combined effect of early dietary zinc intake and BMI on SUA in children.

RESULTS

The dietary zinc intake at 3 years of age was negatively correlated (ρ = −0.18, P = 0.04), whereas the BMI at 7 years of age was positively correlated (r = 0.18, P = 0.01), with the SUA level at 7 years of age. The dietary zinc intake level at 3 years of age and the BMI level at 7 years of age were, together, significantly related to SUA in children at 7 years of age. SUA was lower in group 1 (normal-weight, high-zinc group) than in the other two groups (group 2: normal-weight, low-zinc and overweight, high-zinc group; and group 3: overweight, low-zinc group). Our results demonstrate the combined effect of zinc intake and BMI on SUA. The combined association remained significant in both the crude and adjusted models (P < 0.01).

CONCLUSIONS

SUA was related to combined BMI and dietary zinc intake, and increased zinc intake and normal body weight had a beneficial effect on reducing SUA in children.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Effects of military life on changes in body mass index of enlisted men: a cross-sectional study

Background

Obesity is a serious health problem with an incidence that is increasing rapidly. Enlisted men are a distinctive group characterised by 24-hour community-living and are likely to experience changes in body weight as a result of regular diet and exercise during enlistment.

Methods

This study reviewed data from the Second Military Health Survey. Changes in body mass index (BMI) before and during military service were analysed using paired t-test. We calculated OR and 95% CI for factors affecting weight improvement during military service through logistic regression.

Results

The mean BMI in the underweight group increased by 5.87 kg/m² during service, while that in the normal weight group increased by 1.18 kg/m². In contrast, the mean BMI in the overweight group decreased by 5.47 kg/m² during service. The OR for an improved BMI in the subjective good health group compared with the subjective poor health group was statistically significant (OR=1.71, 95% CI 1.02 to 2.87). The OR for an improved BMI was significantly higher in the group with three or more times per week of strength training than in the group with one to two times per week of strength training, and was higher among the marines compared with the Army soldiers (OR=1.48, 95% CI 1.03 to 2.12 and OR=2.15, 95% CI 1.07 to 4.32, respectively).

Conclusions

Strength training showed a statistically significant increase in BMI during military service. Furthermore, the BMI of men who were underweight before their service increased, while it decreased among those who were overweight.

Associations between earplug use and hearing loss in ROK military personnel

Introduction

The easiest way to prevent noise-induced hearing loss (NIHL) is to wear earplugs. The Republic of Korea (ROK) Ministry of National Defense (MND) is supplying earplugs to prevent NIHL, but many patients still suffer from this. We speculated that earplugs would have a high NIHL rate, depending on the rate of use of earplugs, regardless of the rate of supply. Therefore, we conducted this study to investigate the relationship between the use of earplugs and hearing loss by ROK military personnel.

Methods

The study used data from the Military Health Survey conducted in 2014–2015, which included 13 470 questionnaires completed by ROK military personnel. Hearing loss and earplug use were self-reported. Logistic regression analysis was used to assess associations between earplug use and hearing loss.

Results

The study sample included 13 470 ROK military personnel (response rate of 71.2%) (Army, 8330 (61.8%); Navy/Marines, 2236 (16.6%); and Air Force, 2904 (21.6%)). Overall, 18.8% of Korean military personnel reported that they always wore earplugs, and 2.8% reported hearing loss. In logistic regression analysis, there were significant differences in the rates of hearing loss associated with wearing earplugs sometimes (OR=1.48, 95% CI 1.07 to 2.05) and never wearing earplugs (OR=1.53, 95% CI 1.12 to 2.10). In subgroup analysis, in Air Force, non-combat branch, forward area and long-term military service personnel increased hearing loss was associated with not wearing earplugs.

Conclusion

Our study confirmed that within the ROK military, there is an association between hearing loss and lack of earplug use. In the ROK MND, Army, Navy/Marines and Air Force headquarters must provide guidelines for the use of earplugs during field training to protect military personnel’s hearings and, if necessary, need to be regulated or institutionalised.

Eyeball deviation by orbital mucocele after midface sinus injury

A mucocele is an epithelium-lined, mucus-filled cavity in the paranasal sinuses. Mucocele may develop due to scarring and obstruction of the sinus ostium caused by midface sinus trauma, such as orbital bone fracture or endoscopic sinus surgery. The authors report two cases of orbital mucocele as complications following midface sinus injury (endoscopic sinus surgery in one case, and orbital fracture repair in the other). In both cases, imaging studies showed a large orbital mucocele accompanied by bony erosion and orbital wall remodeling, compressing the ocular muscle. Using an open approach, the lesion was excised and marsupialized. The symptoms resolved, and the postoperative eyeball position was normal. Orbital mucocele may cause serious complications such as ocular symptoms, orbital cellulitis, osteomyelitis, and the formation of an abscess with the potential to invade the brain. Therefore, surgeons should consider the possibility of mucocele as a late complication of surgery and initiate an immediate work-up and surgical treatment if needed.

Accident prevention activity and accident experience in the Republic of Korea military

Introduction

According to data released by the Korea National Statistical Office, the number of accidents has been decreasing since 2012. However, a considerable number of deaths related to safety accidents (23–46 deaths) are still reported annually. This study aimed to observe the correlation between accident prevention activities in the Republic of Korea (ROK) military and the incidence of safety accidents.

Methods

The study used data from the 2014–2015 Military Health Survey and included 13 618 responses (Army: 8414 (61.8%); Navy/Marine: 2262 (16.6%); Air Force: 2942 (21.6%)) from the ROK military personnel. Accident experiences and thoughts on accident prevention activities were self-reported. Multiple logistic regression analysis was used to examine the validity of accident prevention activity and accident experience.

Results

Of the 13 618 military personnel who responded, 12.0% reported experiencing safety accidents in the military and 1020 (7.5%) felt that accident prevention activities in the military were insufficient. On logistic regression analysis, we found a significant difference (insufficiency OR=1.56, CI 1.31 to 1.86). In particular, military personnel who belong to the Army and Navy were more likely to think that accident prevention activities were insufficient. In addition, military personnel who experienced falls/slips, crash, and laceration/puncture wound/amputation/penetrating wound accidents were more likely to think accident prevention activities were insufficient.

Conclusions

Our study found that accident prevention activities in the military and accident experiences were related. It is necessary for the ROK Ministry of Defense, Army, Navy and Air Force headquarters to re-evaluate their accident prevention systems.

Correction of post-traumatic enophthalmos with anatomical absorbable implant and iliac bone graft

BACKGROUND

Trauma is one of the most common causes of enophthalmos, and post-traumatic enophthalmos primarily results from an increased volume of the bony orbit. We achieved good long-term results by simultaneously using an anatomical absorbable implant and iliac bone graft to correct post-traumatic enophthalmos.

METHODS

From January 2012 to December 2016, we performed operations on seven patients with post-traumatic enophthalmos. In all seven cases, reduction surgery for the initial trauma was performed at our hospital. Hertel exophthalmometry, clinical photography, three-dimensional computed tomography (3D-CT), and orbital volume measurements using software to calculate the specific volume captured on 3D-CT (ITK-SNAP, Insight Toolkit-SNAP) were performed preoperatively and postoperatively.

RESULTS

Patients were evaluated based on exophthalmometry, clinical photographs, 3D-CT, and orbital volume measured by the ITK-SNAP program at 5 days and 1 year postoperatively, and all factors improved significantly compared with the preoperative baseline. Complications such as hematoma or extraocular muscle limitation were absent, and the corrected orbital volume was well maintained at the 1-year follow-up visit.

CONCLUSION

We present a method to correct enophthalmos by reconstructing the orbital wall using an anatomical absorbable implant and a simultaneous autologous iliac bone graft. All cases showed satisfactory results for enophthalmos correction. We suggest this method as a good option for the correction of post-traumatic enophthalmos.

P3HT-based visible-light organic photodetectors using PEI/PAA multilayers as a p-type buffer layer

A low leakage current is critical for achieving organic photodetectors (OPDs) with high detectivity. The insertion of buffer layers is an effective approach for reducing the reverse-biased leakage current. In this study, polyelectrolyte multilayers comprising polyethyleneimine (PEI) and polyacrylic acid (PAA) were introduced by a spin-assisted layer-by-layer technique into an OPD as a p-type buffer layer. Although PEI/PAA multilayers are insulators, when used as a buffer layer in our device, they suppressed the leakage current and also provided a high photocurrent due to the light-assisted tunneling effect. The prepared device configuration was ITO/(PEI/PAA)₂/P3HT:PC₆₀BM/Yb/Al. The performances of the OPDs were investigated by measuring the current–voltage characteristics, external quantum efficiency, and transient photocurrent. In addition, the operating mechanism of the OPDs was confirmed by impedance analysis. The device comprising (PEI/PAA)₂ showed a specific detectivity of 3.11 × 10¹² Jones and a bandwidth of 103.2 kHz at −1 V and 525 nm. This performance is a numerical value that can be used in devices such as a line scan camera. In addition, because this device is fabricated by a low-temperature solution process, flexible and large-area substrates can be used.

Although PEI/PAA multilayers are insulators, when used as a p-type buffer layer in organic photodetector, they suppressed the leakage current and also provided a high photocurrent due to the light-assisted tunneling effect.

Enhanced photocurrent in organic photodetectors by the tunneling effect of a hafnium oxide thin film as an electron blocking layer

To achieve high detectivity of organic photodetectors (OPDs), we investigated hafnium oxide (HfO₂) as an electron blocking layer in an attempt to obtain a low leakage current and high photocurrent by the tunneling effect. The prepared devices consisted of indium tin oxide (ITO)/HfO₂/(poly(3-hexylthiophene-2,5-diyl)[P3HT]:PC₆₀BM)/Yb/Al. To explore the tunneling effect in a hafnium oxide thin film, we fabricated a thin film using successive ionic layer deposition. The results for hafnium oxide were compared with those for aluminum oxide and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS). We found that hafnium oxide results in a low leakage current and high photocurrent owing to the tunneling effect in the OPDs. The resulting detectivity of 1.76 × 10¹² Jones for a film thickness of 5.5 nm and bandwidth of ∼100 kHz is suitable for commercialization.

Enhancing Planar Perovskite Solar Cell Performance by Doping Zr in TiOx Layer

In this work, a Zr-doped TiO_x layer is introduced into p-i-n planar-structure perovskite solar cells via a simple sol-gel method. The prepared device configuration is ITO/PEDOT:PSS/CH₃NH₃PbI_xCl_3-x/PC60BM/Zr-TiO_x/Al. The performance of the perovskite solar cells was investigated through measurements of the current-voltage characteristics, impedance analysis, and photocurrent decay. A power conversion efficiency of 15.43% was measured under 1 sun condition; this level of efficiency is 27% higher than that of the device with a Zr-free TiO_x layer. Additionally, the incorporation of Zr into the TiO_x layer improved the carrier extraction as a result of the oxygen vacancy trap passivation. Lastly, the trap passivation of the Zr-TiO_x film was confirmed by analyzing the photoluminescence spectrum.

Solution-Processed Organic Photodetector Using Hafnium Oxide as an Electron Blocking Layer

Organic photodetector (OPD) performance is affected significantly by leakage current. In this study, to decrease OPD leakage current, we introduced hafnium oxide as an electron blocking material, using a solution fabrication process. We fabricated an OPD consisting of ITO/HfO₂/PCHT:PC₆₀BM/Yb/Al, and measured its J-V characteristics, external quantum efficiency, and transient photocurrents. We found that the thickness of the hafnium oxide layer affected the detectivity of the prepared OPD. In particular, a device having an ultrathin hafnium oxide film (5.5 nm thick) exhibited a high on-off current ratio of up to 2.26 × 10⁵ at -1 V, which is two times higher than that of a device having a PEDOT:PSS electron blocking layer.

Capecitabine plus oxaliplatin versus gemcitabine plus oxaliplatin as first-line therapy for advanced biliary tract cancers: a multicenter, open-label, randomized, phase III, noninferiority trial

BACKGROUND

Capecitabine plus oxaliplatin (XELOX) has shown modest activity and tolerable toxicity in a phase II trial for biliary tract cancers (BTCs). Meanwhile, gemcitabine plus oxaliplatin (GEMOX) has been the reference arm in recent phase II and III trials for BTCs. We aimed to investigate the efficacy of XELOX versus GEMOX as first-line therapy for advanced BCTs.

PATIENTS AND METHODS

In this open-label, randomized, phase III, noninferiority trial, we randomly selected patients with metastatic BCTs to receive GEMOX (gemcitabine 1000 mg/m2 on days 1 and 8, and oxaliplatin 100 mg/m2 on day 1) or XELOX (capecitabine 1000 mg/m2, twice daily, on days 1-14 and oxaliplatin 130 mg/m2 on day 1) as first-line treatment, given every 3 weeks, totaling eight cycles. The primary end point was to prove the noninferiority of XELOX to GEMOX in terms of 6-month progression-free survival (PFS) rate.

RESULTS

In total, 114 patients randomly received GEMOX and 108 randomly received XELOX. The median PFS was 5.3 months for the GEMOX group and 5.8 months for the XELOX group. The 6-month PFS rate was 44.5% for the GEMOX group and 46.7% for the XELOX group. The 95% confidence interval of the 6-month PFS rate difference between both groups was -12% to 16%, meeting the criteria for noninferiority of XELOX to GEMOX. There was no difference in objective response (P=0.171) and median overall survival (P=0.131) between both groups. The most common grade three to four adverse events were neutropenia and thrombocytopenia. No patient died of treatment-related causes. The XELOX group had significantly lower frequencies of hospital visits than the GEMOX group (P<0.001).

CONCLUSION

XELOX showed significant noninferiority to GEMOX in terms of 6-month PFS rate. Thus, XELOX could be an alternative first-line treatment of BCTs.

TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (number NCT01470443).

Correction: High-detectivity perovskite-based photodetector using a Zr-doped TiOx cathode interlayer

Correction for ‘High-detectivity perovskite-based photodetector using a Zr-doped TiO_x cathode interlayer’ by C. H. Ji et al., RSC Adv., 2018, 8, 8302–8309.

Dietary patterns related to exposure to persistent organic pollutants based on the Ewha Birth and Growth Cohort

Persistent organic pollutants (POPs) are endocrine disruptors that are typically ingested in food. Using data from the Ewha Birth and Growth Cohort study, we identified dietary patterns related to blood persistent organic pollutant (POP) levels in children. In total, 188 Korean children (95 boys and 93 girls) aged 7-9 years were included in this study. Daily food intake data derived from a semi-quantitative food-frequency questionnaire were grouped into 33 food groups. Dietary patterns were analyzed using the reduced rank regression method, with blood POP levels as dependent variables. The marker polychlorinated biphenyl (PCB) pattern showed more weighted loading factors in the intake of shellfish/salted seafood, cheese, nuts and seeds, and total PCBs showed similar results. The dioxin-like PCB pattern was characterized by a higher intake of yogurt, beverages, and fruit and a lower intake of grain, seaweeds, and processed meat. Additionally, the total organochlorine pesticide (OCP) pattern showed positive factor loading values in shrimp and beverages, and negative factor loading values in seaweeds and processed meat. Each dietary pattern accounted for 25.0% of total OCPs, 22.9% of dioxin-like PCBs, 21.6% of marker PCBs, and 21.3% of total PCBs in blood. Dietary pattern scores were linearly related to blood POP levels, and this association remained after adjusting for sex, age, follow-up survey year, maternal educational level, body mass index, and total energy. Dietary patterns differed slightly among the individual POPs. Further studies are needed to develop an intervention strategy for children.

Importance of Timed and Detailed Evaluation of Kidney Transplantation Candidates

Kidney transplant recipients are at increased risk of cardiovascular morbidity and malignant neoplasm, and meticulous evaluation of potential recipients is needed to minimize risks of complications after transplantation. The purpose of this study was to analyze the results of preoperative assessments and document the importance of timed and detailed examinations.

METHODS

Medical records of patients evaluated as kidney transplant candidates from January 2015 to September 2017 were retrospectively collected and analyzed.

RESULTS

Of the 216 patients evaluated during the study period, 135 (62.5%) were male, 112 (51.9%) had diabetes mellitus, 163 (75.5%) had hypertension, 31 (14.4%) had a cardiovascular event history, and 7 (3.2%) had previous history of malignant neoplasms. Mean (SD) patient age was 50.7 (10.8) years. All 216 recipient candidates underwent echocardiography. Mean (SD) ejection fraction was 57.8% (5.9%), and 48 candidates (22.2%) showed regional wall motional abnormality. Coronary angiography was performed on 81 candidates, and in 57 (70.4%) of these, coronary artery disease was detected. Malignant neoplasms were detected in 10 (4.6%) candidates. Kidney transplantation was performed on 55 candidates. One recipient died of Pneumocystis jirovecii pneumonia at 15 months after kidney transplant, but there was no death-censored graft failure, newly detected malignant neoplasm, or cardiovascular event over a mean (SD) follow-up duration of 15.5 (8.6) months.

CONCLUSION

Evaluation of kidney transplant candidates resulted in diagnoses of malignant neoplasms in 4.6% of patients and coronary artery disease in 26.4% of patients. The results of this study demonstrate candidates for kidney transplant should undergo detailed preoperative evaluation.

Abstract OT3-06-07: A phase I/II dose escalation and expansion study to investigate the safety, pharmacokinetics, pharmacodynamics and clinical activity of GSK525762 in combination with fulvestrant in subjects with ER+ breast cancer

Background:

Advanced or metastatic ER+BC (estrogen receptor positive breast cancer) is an incurable illness that will prove fatal for most afflicted women. Current standards of care include endocrine, targeted, and chemotherapy. Preclinical data suggest that altering the expression of the estrogen receptor (ER) as well as other ER-responsive genes may provide therapeutic benefit for women for whom endocrine therapy alone has proven inadequate. The bromodomain (BRD) and extra-terminal (BET) family of proteins (BRD2, BRD3, BRD4 and BRDT) bind to acetyl-histone residues and epigenetically control transcription of genes driving cell survival and proliferation. BET proteins have been implicated in carcinogenesis and treatment resistance in multiple tumors including ER+BC, and are a novel target for therapy in breast cancer. GSK525762 is a pan-BET inhibitor that has shown strong synergistic activity with fulvestrant in killing ER+BC cells in vitro and in xenograft models. The combination of BET agents with endocrine therapy may provide therapeutic benefit and restore sensitivity to ER targeting agents like fulvestrant.

Trial Design & Specific Aims:

This study is a Phase I/II dose-escalation, expansion (Phase I) and randomized control (Phase II) study with oral administration of GSK525762 in combination with fulvestrant in advanced or metastatic ER+BC subjects, whose disease has progressed on prior treatment with at least one line of endocrine therapy.

Phase I of the study is designed as parallel single arms to determine a recommended Phase 2 dose (RP2D) based on safety, tolerability, pharmacokinetic, and efficacy profiles in two distinct populations of ER+ breast cancer:

Subjects with disease that relapsed during treatment or within 12 months of adjuvant therapy with an AI, OR disease that progressed during treatment with an AI for advanced/metastatic disease.

OR

Subjects with disease that progressed during treatment with the combination of a CDK4/6 inhibitor plus letrozole for advanced or metastatic disease.

Phase II of the study is a randomized, double-blind, placebo-controlled cohort, designed to evaluate the efficacy of the combination.

Key Eligibility Criteria: Patients must have received &lt;3 lines of systemic anti-cancer therapy (≤1 line of chemo), measurable disease, and PS 0-1.

Statistical Methods: A modified toxicity probability interval (mTPI) design will be used to monitor safety. A Bayesian adaptive design will be used to evaluate efficacy in Phase 1.

Present and Target Accrual: Target enrolment will be ˜300 subjects across ˜50 sites worldwide. To date, 2 subjects have been enrolled.

Contact Information: Elizabeth Cunningham, Elizabeth.A.Cunningham@GSK.com.

NCT02964507

Funding: GSK

Citation Format: Pluard T, Oh SY, Oliveira M, Cescon D, Tan-Chiu E, Wu Y, Carpenter C, Cunningham E, Ballas M, Dhar A, Sparano J. A phase I/II dose escalation and expansion study to investigate the safety, pharmacokinetics, pharmacodynamics and clinical activity of GSK525762 in combination with fulvestrant in subjects with ER+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-06-07.

A prospective cohort study of the association between bisphenol A exposure and the serum levels of liver enzymes in children

BACKGROUND

Bisphenol A (BPA) is an endocrine disrupter that acts in an estrogen-like manner. Few studies have investigated the association between urinary BPA concentrations and adverse liver function. Additionally, most studies were cross-sectional in nature and included only adults.

OBJECTIVES

We evaluated BPA exposure levels and prospectively explored the association between BPA exposure and liver function in children.

METHODS

Data were retrieved from the ongoing prospective Ewha Birth and Growth Cohort Study. Urinary BPA concentrations were measured in 164 children at 3-5 and 7-9 years of age. At each visit, fasting blood and urine samples were collected, and questionnaires were completed. The associations between the BPA concentrations at these ages and the serum levels of liver enzymes measured at 10-13 years of age were analyzed (n = 113). Multiple regression analysis was performed with adjustment for covariates. We also explored whether the BPA level exhibited dose-response relationships with liver enzyme levels.

RESULTS

The median urinary BPA concentrations were 0.76μg/g creatinine at 3-5 years and 0.61μg/g creatinine at 7-9 years of age. The urinary BPA concentrations at the two ages were correlated significantly (r = 0.23, p < 0.01). The urinary BPA concentrations at 7-9 years, but not that at 3-5 years, was associated significantly with the serum levels of liver enzymes at 10-13 years of age (p < 0.05). Those in the top tertile of urinary BPA concentration had higher levels of liver enzymes than did others. After adjustment for covariates, dose-response relationships of the BPA level with liver enzyme levels were evident at 7-9 years, but not at 3-5 years. Notably, the effect size was larger and the dose-response relationships were more evident in boys than in girls.

CONCLUSIONS

Exposure of children to even low doses of BPA may adversely affect later liver function.

Effects of essential oil (blended and single essential oils) on anti-biofilm formation of Salmonella and Escherichia coli

Background

Biofilms were the third-dimensional structure in the solid surface of bacteria. Bacterial biofilms were difficult to control by host defenses and antibiotic therapies. Escherichia coli (E. coli) and Salmonella were popular pathogenic bacteria that live in human and animal intestines. Essential oils are aromatic oily liquids from plant materials and well known for their antibacterial activities.

Method

This study was conducted to determine effect of essential oil on anti-biological biofilm formation of E. coli and Salmonella strains in in vitro experiment. Two kinds of bacterial strains were separated from 0.2 g pig feces. Bacterial strains were distributed in 24 plates per treatment and each plates as a replication. The sample was coated with a Bacterial biofilm formation was.

Result

Photographic result, Escherichia coli (E. coli) and Salmonella bacteria colony surface were thick smooth surface in control. However, colony surface in blended and single essential oil treatment has shown crack surface layer compared with colony surfaces in control.

Conclusion

In conclusion, this study could confirm that essential oils have some interesting effect on anti-biofilm formation of E. coli and Salmonella strains from pig feces.

Which Diet-Related Behaviors in Childhood Influence a Healthier Dietary Pattern? From the Ewha Birth and Growth Cohort

This study was performed to examine how childhood dietary patterns change over the short term and which changes in diet-related behaviors influence later changes in individual dietary patterns. Using food frequency questionnaire data obtained from children at 7 and 9 years of age from the Ewha Birth and Growth Cohort, we examined dietary patterns by principal component analysis. We calculated the individual changes in dietary pattern scores. Changes in dietary habits such as eating a variety of food over two years were defined as “increased”, “stable”, or “decreased”. The dietary patterns, termed “healthy intake”, “animal food intake”, and “snack intake”, were similar at 7 and 9 years of age. These patterns explained 32.3% and 39.1% of total variation at the ages of 7 and 9 years, respectively. The tracking coefficient of snack intake had the highest coefficient (γ = 0.53) and that of animal food intake had the lowest (γ = 0.21). Intra-individual stability in dietary habits ranged from 0.23 to 0.47, based on the sex-adjusted weighted kappa values. Of the various behavioral factors, eating breakfast every day was most common in the “stable” group (83.1%), whereas consuming milk or dairy products every day was the least common (49.0%). Moreover, changes in behavior that improved the consumption of milk or dairy products or encouraged the consumption of vegetables with every meal had favorable effects on changes in healthy dietary pattern scores over two years. However, those with worsened habits, such as less food variety and more than two portions of fried or stir-fried food every week, had unfavorable effects on changes in healthy dietary pattern scores. Our results suggest that diet-related behaviors can change, even over a short period, and these changes can affect changes in dietary pattern.

When is facial diplegia regarded as a variant of Guillain-Barré syndrome?

A variant of Guillain-Barré syndrome (GBS) with predominant manifestation of facial diplegia (FD) has been described recently. This study aimed to characterize and determine the incidence of this FD-predominant GBS variant. The clinical and serological information of 900 consecutive patients were reviewed. In total, eight patients were identified between January 2007 and December 2010 as having FD accompanied by some features of GBS. These features were subjective sensory symptoms such as distal paresthesia (7/8, 88%), albumin-cytological (A/C) dissociation (7/8, 88%), antecedent infection (6/8, 75%), and minor nerve conduction study (NCS) abnormalities (5/7, 71%). One patient presented with the typical NCS feature of demyelinating neuropathy. Only two patients exhibited areflexia (2/8, 25%). None of the patients possessed any anti-ganglioside antibodies; however, the serum of two patients was positive for anti-mycoplasma antibody (2/6, 33%). FD variant of GBS occurred in less than 1% of our dataset. FD can be a regional variant of GBS when it is accompanied by supporting features, such as subjective tingling, A/C dissociation, and minor NCS abnormalities.

Extraocular muscle injury during endoscopic sinus surgery: an ophthalmologic perspective

PurposeThe purpose of this study is to describe the clinical characteristics and treatment results of medial rectus muscle (MR) transection incurred during endoscopic sinus surgery.MethodsThis retrospective study included 16 patients with MR transection incurred during endoscopic sinus surgery between 1994 and 2015. The operative notes of the surgical procedure, the pattern of strabismus, the type of muscle injury, the type of corrective strabismus surgery, and the surgical outcomes were reviewed.ResultsNine patients had partial resection of MR and seven patients had complete transection of MR, resulting from an injury incurred during endoscopic sinus surgery. Three of the nine patients with partial resection injury were initially diagnosed as complete resection and subsequently re-diagnosed as partial resection in a review of the images during this study. Five of the nine patients with partial MR resection underwent only simple recession/resection surgery. Patients with complete MR transection underwent muscle transposition or globe fixation surgeries and often multiple operations were required.ConclusionsThe results of this study showed that the treatment strategies could vary depending on the nature of muscle injury. In cases with complete transection, muscle transposition or globe fixation surgeries are often required, with multiple operations. However, partial muscle resection with only simple recession/resection surgery shows a favorable outcome in many cases. The use of proper imaging techniques, a thorough review of the images with various planes, and close follow-up are important for determining the nature of the muscle injury.

Short communication: Ovine leukocyte telomere length is associated with variation in the cortisol response to systemic bacterial endotoxin challenge

Stress has been associated with biological aging and numerous age-related diseases. This may be due, in part, to accelerated shortening of telomeres, which are critical genomic structures that cap and protect chromosomal ends. Dysfunction of the hypothalamic-pituitary-adrenal axis may indirectly contribute to telomere shortening if an animal reacts too strongly or weakly to a stressor, leading to accelerated biological aging. In this study, outbred Rideau-Arcott sheep were stress challenged with Escherichia coli endotoxin and classified as high, middle, or low cortisol responders to investigate a potential relationship between cortisol response and age, and telomere length. In the present study, no association was found between age and telomere length. The study, however, revealed shorter telomeres in high and low cortisol responders compared with the middle cortisol responders, which suggests that health and longevity may be compromised in extreme high- and low-stress-responding sheep.

Retinal nerve fiber layer thickness in prematurity is correlated with stage of retinopathy of prematurity

PURPOSE

To compare retinal nerve fiber layer (RNFL) thickness profiles between preterm and full-term children and to investigate factors affecting the RNFL distribution in preterm children.

METHODS

We performed Spectral domain optical coherence tomography (SD-OCT) peripapillary RNFL circular scan centered on the optic disc in 50 premature and 58 full-term children. RNFL thickness profiles were compared between preterm and full-term children using a linear regression model. Among preterm patients in this study, 20 patients previously received laser treatment for severe retinopathy of prematurity (ROP).

RESULTS

Global average, nasal, and superior disc RNFL thickness profiles were significantly smaller in preterm children (92.70±16.57 μm, 56.02±17.04 μm, and 108.74±27.36 μm, respectively) compared with full-term children (101.63±9.21 μm, P=0.006, 69.14±14.15 μm, P<0.001, and superior, 129.11±18.14 μm, P<0.001, respectively). Multivariable analysis revealed that ROP stage was inversely correlated with nasal RNFL thickness (P=0.010).

CONCLUSIONS

Our SD-OCT data demonstrate decreased global average, nasal, and superior disc RNFL thicknesses in preterm children. ROP stage was inversely correlated with nasal RNFL thickness. Further studies are needed to better understand the association between these structural changes and visual functions in preterm children.

Cup-to-disc and arteriole-to-venule ratios in preterm birth

AIMS

To investigate the influence of preterm birth on the optic disc and retinal vessels by measurements of cup-to-disc (C/D) ratio and arteriole-to-venule (A/V) ratio.

METHODS

Eighty-three eyes of 42 preterm births were included. In the age- and sex-matched control group, 83 eyes of 42 full-term births were used. Fundus color photographs were taken. ImageJ software was used to calculate C/D and A/V ratios from the fundus images.

RESULTS

Fundus photographs were taken at 8.01 ± 2.22 years of age for the preterm group and 8.01 ± 2.13 years of age for the control group. The mean gestational age of the preterm group was 27(4)/7 weeks (range, 24-34 weeks). The preterm group had significantly larger C/D ratio and smaller A/V ratio (mean ± standard deviation: 0.46 ± 0.12 and 0.59 ± 0.08, respectively) than the control group (0.36 ± 0.07 and 0.68 ± 0.07, respectively) after spherical equivalent refractive error was adjusted.

CONCLUSIONS

Preterm birth is significantly associated with larger C/D ratio and smaller A/V ratio. These findings show the effect of preterm birth on the development of optic disc and retinal vessel development.

Studies on the Characteristics of Vertical Organic Transistor with Nano Patterned Gate Using Block Copolymer

In this study, we fabricated and studied the device characteristics of vertical organic transistors consisting of nano-patterned gates constructed from the self-assembly of block copolymer. The size of the gate opening made by the new method was 30~40 nm. The device was compared with those which had gate openings of 200 nm. These lager devices were constructed from monodispersed colloidal polystyrene spheres. The device which used block copolymer showed significant improvements in its on-off ratio. We also fabricated transistors with tungsten oxide buffer layer to increase the on current of the device. The devices were analyzed based on their current-voltage charac- teristics, impedance spectroscopy, atomic force microscope (AFM) images and scanning electron microscope (SEM) images.

Optimal Fabrication of P3HT:PCBM Based Organic Solar Cells with N-Type DMDCNQI Dopant

We have fabricated P3HT and PCBM-based organic photovoltaic cells using DMDCNQI as a guest dopant material and an n-type buffer layer. We have investigated the physical effects of the DMD-CNQI molecule as a guest dopant and an n-type charge transfer buffer layer on the performance of the device by examining measurements of light current-voltage and photoluminescence characteristics. The device using DMDCNQI as a dopant and a buffer layer exhibited a remarkable increase in short-circuit current density (Jsc) due to the ability of an electron acceptor and to the formation of a highly conducting charge transfer complex. In particular, the device consisting of ITO/PEDOT:PSS/P3HT:PCBM:DMDCNQI(1 wt%)/DMDCNQ/Al showed a maximum power conversion efficiency of 3.50%.

Synthesis and Characteristics of Fullerene Derivatives with Hexyl Perylene Moieties as N-Type Materials in Organic Solar Cells

Recently, fullerene derivatives have received significant attention due to their potential impacts on the development of high performance organic photovoltaic (OPV) cells. One of the most successful fullerene derivatives thus far is [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM), which is being used as an electron acceptor material. However, PCBM has some disadvantages concerning its application in OPV cells, such as a weak absorption rate in the visible region and a relatively low LUMO level. In the present work, we synthesized a novel fullerene derivative, called hexyl perylene fullerene (HPF), which contains a hexyl perylene moiety. The HPF molecules showed two absorption peaks at 340 nm and 450 nm corresponding to the fullerene and to the perylene moiety, respectively. 1,8-octanedithiol was used as an additive to improve the compatibility between the poly(3-hexylthiophene) (P3HT) and the synthesized HPF The characteristics of an OPV cell composed of ITO/PEDOT:PSS/P3HT:HPF:1,8-octanedithiol/Al were investigated.

Korean research project on the integrated exposure assessment of hazardous substances for food safety

OBJECTIVES

This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg).

METHODS

We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey.

RESULTS

Pb and Cd were the highest (median value) in the seaweed (94.2 μg/kg for Pb; 594 μg/kg for Cd), and Hg was the highest in the fish (46.4 μg/kg). The dietary exposure level (median value) of Pb was 0.14 μg/kg body weight (bw)/d, 0.18 μg/kg bw/d for Cd, and 0.07 μg/kg bw/d for Hg. Those with a blood Pb level of less than 5.00 μg/dL (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than 0.30 μg/L (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than 5.00 μg/L (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects.

CONCLUSIONS

The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

Relationship of serum 25-Hydroxyvitamin D (25[OH]D) levels and components of metabolic syndrome in prepubertal children

OBJECTIVE

The relationship between 25-hydroxyvitamin D (25[OH]D) levels and the lipid and metabolic levels of the prepubertal normal population is unclear. Our goals were to investigate the association of serum 25(OH)D concentrations with lipid and metabolic levels in Korean prepubertal children ages 7-9 y.

METHODS

We followed 205 children, ages 7-9 y in the Ewha Birth and Growth Cohort study, a prospective cohort sample established in 2001-2006, from July to August 2011. We studied the association of serum 25-hydroxyvitamin D (25[OH]D) levels with components of metabolic syndrome and insulin resistance indices using multivariate regression analysis adjusted for body mass index (BMI) z-scores.

RESULTS

The mean age of the 205 subjects was 7.89 ± 0.85 y, and the sample included 109 boys (53.2%). The average 25(OH)D levels of all participants was 25.0 ± 5.4 ng/mL. After adjustment for age and sex, triacylglycerol levels were significantly associated with 25(OH)D (β = -0.02, P = 0.02) concentrations even after adjustment for BMI z-scores (β = -0.02, P = 0.04). However, other metabolic components were not correlated with 25(OH)D status. Those with the lowest quartile of 25(OH)D levels had the highest serum triacylglycerol levels (P = 0.04, Ptrend = 0.01).

CONCLUSIONS

We found that serum 25(OH)D levels were negatively associated with serum triacylglycerol levels, even independently of adiposity, in prepubertal children. This study suggests that 25(OH)D insufficiency is related to metabolic syndrome via the derangement of triacylglycerol metabolism.

Arachidonic acid promotes skin wound healing through induction of human MSC migration by MT3-MMP-mediated fibronectin degradation

Arachidonic acid (AA) is largely released during injury, but it has not been fully studied yet how AA modulates wound repair with stem cells. Therefore, we investigated skin wound-healing effect of AA-stimulated human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in vivo and its molecular mechanism in vitro. We found that transplantation of hUCB-MSCs pre-treated with AA enhanced wound filling, re-epithelization, and angiogenesis in a mouse skin excisional wound model. AA significantly promoted hUCB-MSCs migration after a 24 h incubation, which was inhibited by the knockdown of G-protein-coupled receptor 40 (GPR40). AA activated mammalian target of rapamycin complex 2 (mTORC2) and Akt^ser473 through the GPR40/phosphoinositide 3-kinase (PI3K) signaling, which was responsible for the stimulation of an atypical protein kinase C (PKC) isoform, PKCζ. Subsequently, AA stimulated phosphorylation of p38 MAPK and transcription factor Sp1, and induced membrane type 3-matrix metalloproteinase (MT3-MMP)-dependent fibronectin degradation in promoting hUCB-MSCs motility. Finally, the silencing of MT3-MMP in AA-stimulated hUCB-MSCs failed to promote the repair of skin wounds owing to impaired cell motility. In conclusion, AA enhances skin wound healing through induction of hUCB-MSCs motility by MT3-MMP-mediated fibronectin degradation, which relies on GPR40-dependent mTORC2 signaling pathways.

Studies on the Properties of Organic Photovoltaic Cells Using TiOx and DMDCNQI as Double Buffer Layers

Various types of n-type buffer layers have been used in organic electronic devices. These buffer layers turned out to expedite carrier injection and reduce series resistance, leading to good performance of organic electronic devices. In our current work, we have fabricated organic photovoltaic (OPV) cells consisting of ITO/PEDOT:PSS/P3HT:PCBM/TiOx/DMDCNQI/AI which were fabricated in the presence of air. To incorporate the individual advantages of each n-type buffer layer, a DMDCNQI and TiOx layers were inserted to act as n-type double buffer layers. This leads to an increase of short-circuit current (JSC) and fill factor (FF) with good stability, in comparison to P3HT:PCBM based conventional cells. The results imply that the structures of double buffer layers can provide possible alternative to achieving high performance and air durability.

Characteristics and Durability of Vertical-Type Organic Light-Emitting Transistors Using Poly(2-methoxy-5-(2- ethyl hexyloxy)-1,4-phenylenevinylene) and Indenofluorenedione Derivatives

In this study, we have fabricated vertical organic light emitting transistors using indenofluorenedione derivatives (IF-dione-F) as an n-type organic semiconductor. IF-dione-F shows high performance n-type semiconductors owing to the fluorine group in the IF-dione-F backbone. The fluorine group has an electron-withdrawing property. Thus, IF-dione-F shows high electron affinity and good durability. The configuration of the vertical organic light emitting transistors was ITO (drain)/

PEDOT

PSS/MEH-PPV/IF-dione-F/AI (gate)/IF-dione-F/Al (source). The characteristics of the vertical organic light emitting transistors were investigated from the measurements of radiancevoltage characteristics and external quantum efficiency. Furthermore, air stability was studied from the measurements of characteristics, impedance spectroscopy and contact angle.

Novel Risk Factors for Allergic Rhinitis in Korean Elementary School Children: ARCO-kids Phase II in a Community

Purpose

Allergic rhinitis (AR) is a multifactorial disease whose genetic and environmental risk factors have been studied for decades. Many pediatric studies have pointed out the familial history of allergy, hygiene hypothesis, breast-feeding, pet ownership, and diets as risk factors of AR. However, most of factors are still up for debate. This preliminary report aimed to confirm the known risk factors and find the novel risk factors for AR in the Korean pediatric population.

Methods

A bi-seasonal, winter and summer, study in 2 elementary schools included all students whose parents completed the questionnaire of medical and social histories, quality of life, infant and early-childhood history, and the living styles. Skin prick tests and endoscopic examinations were conducted on all participants.

Results

Among total 1,020 children, 338 participants had AR. The multivariate logistic regression analysis highlighted 6 factors: male gender (OR, 2.10; 95% CI, 1.32-3.33), older age (1.65; 1.03-2.65), previous history of allergic conjunctivitis (14.25; 4.99-40.74), asthma (2.73; 0.96-7.76) and pneumonia (0.39; 0.19-0.82), and an hour increase in daily playing time (0.90; 0.80-1.00).

Conclusions

Lack of pneumonia in early childhood and short playing time are newly found risk factors for Korean pediatric AR in this study confirming male gender, older age and previous history of allergic conjunctivitis and asthma as the risk factors.

Extraocular muscle injury during endoscopic sinus surgery: a series of 10 cases at a single center

BACKGROUND

Extraocular muscle (EOM) injury is a rare but serious complication of endoscopic sinus surgery (ESS). The aim of this study is to describe the clinical characteristics and course of EOM injury occurring during ESS.

DESIGN

Retrospective case series.

METHODS

Medical records and CT images of patients who suffered from EOM injury after ESS between 2006 and 2012 were retrospectively reviewed. Patient demographics, endoscopic anatomy, type of surgery (primary or revision), predisposing risk factors, site and extent of injury on CT imaging, and associated complications were evaluated. In addition, data regarding ophthalmologic management and clinical outcomes were collected.

RESULTS

Ten patients with EOM injuries after ESS were included in this study. One patient was undergoing revision ESS. All patients sustained medial rectus muscle injury and one patient suffered concurrent ipsilateral inferior rectus muscle injury. A microdebrider was used in nine cases. Right-sided injury (90% of patients) was more prevalent than left-sided injury, and 70% of injured medial rectus muscles were completely transected. After subsequent strabismus surgery, 8/9 patients regained binocular single vision in primary gaze despite residual diplopia in some gaze positions.

CONCLUSION

Although proper ophthalmologic surgery after EOM injury may improve deviation in the primary gaze position, none of the patients regained normal EOM movement. Therefore, prevention of this complication through adequate surgical technique and precautions is important.

Relationship among attention-deficit hyperactivity disorder, dietary behaviours and obesity

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood and can be associated with obesity. The aim of this study was to reveal the connection between ADHD symptoms, food habits and obesity.

METHODS

We examined 12 350 children (6010 boys, 6340 girls) from 27 elementary schools in Cheonan, the Republic of Korea. The study subjects were 5- to 13-year-old children (9.4 ± 1.7 years). Parents completed the DuPaul ADHD Rating Scale. Food habits were measured by a questionnaire adapted from the Korea Youth Risk Behavior Web-based Survey and a validated mini-dietary assessment tool. The full set of hypothesized associations was tested using covariance structural modelling.

RESULTS

The prevalence of ADHD was 7.6% and that of obesity was 4.5% in our study population. The data was well fit by the model. ADHD was associated with body mass index (BMI; standardized β = 0.086, P < 0.001). Bulimic dietary behaviours was related to BMI (standardized β = 0.548, P < 0.001). Socio-economic status was associated with BMI (standardized β = -0.017, P = 0.027).

CONCLUSION

Our analysis suggested that ADHD was a risk factor for obesity through dietary behavioural change and socio-economic status.

Physical effects of DCNQI derivatives doping as an N type organic semiconductor in organic photovoltaic cell performance

In the previous work, we have reported that organic photovoltaic (OPV) cells using DMDCNQI as an n-type second dopant material showed a high power conversion efficiency (PCE). In the present work, we have synthesized a novel DHDCNQI with long alkyl chains to improve the compatibility between the DHDCNQI dopant molecule and host P3HT polymer. We have fabricated OPV cells consisting of ITO/PEDOT:PSS/P3HT:PCBM:DHDCNQI/Al. We have investigated the characteristics of theses OPV cells using DCNQI derivative dopants from the measurements of the incident photon-to-current collection efficiency and photocurrent. The OPV cell using 3 wt% DHDCNQI exhibited a high PCE of 3.29% due to the high charge separation efficiency, good compatibility and low trap site effect.

Characteristics of vertical type polymer light emitting transistor using dimethyldicyanoquinonediimine as a N-type buffer layer

Contact resistance between a metal electrode and an organic active layer is one of the most critical issues in the research and development of organic electronic devices. In the present work, we have fabricated vertical type organic light emitting transistor (OLET) using P3HT as a organic active semiconductor and DMDCNQI as a charge transfer material. The device configuration is ITO/PEDOT:PSS/P3HT/Al gate/P3HT/DMDCNQI/Al. The characteristics of OLET were investigated from the measurement of current-radiance voltage characteristics The needle form of highly conducting DMDCNQI-Al charge transfer complex was obtained, which resulted in the improvement of device performance due to the low organic-metal contact resistance and the high electron transport ability.

Solvent effects of a dimethyldicyanoquinonediimine buffer layer as N-type material on the performance of organic photovoltaic cells

In the present work, we have fabricated organic photovoltaic cells consisting of ITO/PEDOT:PSS/P3HT:PCBM/DMDCNQI/Al using a dip-coating method with various solvent systems. We have investigated solvent effects (such as solubility, viscosity and vapor pressure) in deposition of a thin DMDCNQI buffer layer on the performance of organic photovoltaic cells. The solvent system which had low viscosity and good solubility properties, made a dense and uniform DMDCNQI ultra thin film, resulting in a high performance device. In particular, a prepared organic photovoltaic cell was fabricated using a cosolvent system (methanol:methylenechloride = 3:1) and showed a maximum power conversion efficiency of 4.53%.

Estimated long-term dietary exposure to lead, cadmium, and mercury in young Korean children

BACKGROUND

Controlling for day-to-day variation is a key issue in estimating long-term dietary exposure to heavy metals using 24-hour recall (24HR) data from a relatively small number of days.

OBJECTIVES

This study was conducted to estimate long-term dietary exposure to lead, cadmium and mercury among Korean children using the Iowa State University (ISU) method and to assess the contributions of different food groups to heavy metal intake.

METHODS

We analyzed 2 days of 24HR data from 457 children between 0 and 6 years of age in 2010. Using bootstrapped concentration data for 118 representative foods, 93.5% of total intake was included in the exposure estimates in this study. Using the 2-day exposure data, we estimated long-term exposure by controlling for within-individual variation using the ISU method.

RESULTS

The long-term dietary exposure estimates (mean±standard deviation) for lead, cadmium, and mercury were 0.47±0.14, 0.38±0.20, and 0.22±0.08 μg/kg bw/day, respectively. For lead and cadmium, the percentages of children whose exposure was greater than the reference value were 35 and 42%, respectively. Fruits were an important source of lead exposure, and cereal and fish and shellfish made the greatest contributions to the total cadmium and mercury exposure.

CONCLUSIONS

Our findings also suggest that the long-term exposure to lead and cadmium was somewhat greater than the reference values, whereas mercury exposure was well below than the reference value in this population. Further studies may be necessary to evaluate the food items contributing to heavy metal exposure, and continuous monitoring is needed to ensure the safety of food intake and dietary patterns among vulnerable groups in Korea.

Motion-free all optical inspection system for nanoscale topology control

We present a novel all optical method for nanoscale pattern inspection. This method uses the chromatic aberration in an imaging optical system and a tunable light source. Such an approach allows stable and precise inspection of nanoscale objects based on an analysis of their defocused diffraction patterns without any external mechanical influence on the sample or optical system. We demonstrate the efficiency of a low cost light source tunable in the range of a light emitting diode bandwidth of ~30 nm (FWHM) for providing the required defocusing. The proposed method is tested using calibrated lines (height 50 nm, length 100 μm, critical dimension (СD) value range 40-150 nm with 10 nm steps) on a monocrystalline silicon substrate with demonstrated measurement accuracy better than 10 nm. A comparison of this all optical method with a mechanical scanning inspection system is discussed.

Electrorheological response of inorganic-coated multi-wall carbon nanotubes with core-shell nanostructure

The effect of coating thickness and sequence on the multi-wall carbon nanotube (MWCNT) surface on electrorheological (ER) activity is investigated. Silica-coated MWCNTs with different shell thicknesses and inorganic-coated MWCNTs with different shell sequences are fabricated using the sol-gel process. The morphology and elemental analyses of the core-shell structured MWCNTs were performed and the effect of coating thickness and coating materials on the MWCNT surface on ER and dielectric properties of inorganic-coated MWCNT suspensions have been analyzed from the measurement results of shear stress, viscosity, current density and permeability. The electrical conductivity of silica-coated MWCNTs decreases with an increase of the shell thickness. However, the dynamic yield stress and viscoelastic properties under an external electric field increased when the shell thickness reached 20 nm and then decreased with the thickness up to 40 nm. However, the titania-coated MWCNT suspension with a shell thickness of 40 nm showed the highest dynamic yield stress compared to the other core-shell structured MWCNT suspension at the same volume fraction. It has been found that the material of the outermost shell plays an important role in the ER performance. It has been concluded that the electrical conductivity and the permittivity of the MWCNTs can be controlled by adjusting the coating thickness and sequence of inorganic materials.