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A slot structure was combined with a discharge electrode to limit incident high-power microwaves via the integration of plasma discharge. At the target resonating frequency of 9.45 GHz, the surface current was concentrated at an electrode, and the electric field was enhanced by the proposed design to lower the response power level of the incident signal. When a low-power signal is injected, plasma is not generated, and the incident wave travels without insertion loss. Double-stage slot structures were utilized to broaden the band-pass characteristics in the frequency domain, and the demonstrated plasma limiter exhibited an insertion loss of 1.01 dB at 9.45 GHz. The xenon gas pressure was optimized with the shortest distance of 100 µm between the upper and lower electrodes to reduce the discharge power of the plasma. In the case of a high-power signal input, as xenon-gas breakdown occurred, the transmitted signal was close to zero, and most of the high-power signal was reflected with a blocking efficiency of 40.55 dB.

Governments worldwide have committed to extending choices in public management to deliver services effectively; yet, how these programmes ensure equality remain unclear. This study investigated whe...

Purpose: Recent advances in the treatment of breast cancer has led to the improvement of breast cancer patient’s survival. With prolonged survival of these patients, pregnancy became an important issue, especially in those of young cancer patients aged 35 or under. Increased hormone levels during pregnancy, however, raises concerns of elevating the risk of cancer recurrence. The aim of this study was to validate the notion of increased risk associated with pregnancy after breast cancer treatment in young patients. Methods: From January 2009 to December 2020, newly diagnosed breast cancer patients of 35 years old or under who underwent curative surgery in Korea University Guro Hospital were enrolled in this study. Patients were categorized into 3 groups: nulliparous, pregnancy prior to treatment of breast cancer, and patients with pregnancy after breast cancer treatment. Their overall survival and disease-free survival were evaluated. Results: A total of 126 patients was enrolled in this study. Seventeen patients (13.4%) conceived and successfully delivered. The mean age of enrolled patients was 32.0 years old (± 3.1), and the mean follow up period after surgery was 56.8 months (± 34.2). There was no significant difference in overall survival (p=0.490) and disease-free survival (p=0.740) among different groups. Among 22 patients with re-diagnosis of breast cancer, 2 of them (9%) had breast cancer on their contralateral breast. Conclusion: In young patients, pregnancy after treatment for breast cancer did not affect their overall survival or disease-free survival as compared to nullipara or previously delivered groups. Therefore, pregnancy counseling should not be prevented in young breast cancer patients of 35 years old or under. Citation Format: Ji Hye Kim, Sang Uk Woo, Jae Bok Lee, Woo Young Kim, Jai Hyun Chung, Yong Yeup Kim. Oncologic outcomes of pregnancy after surgical treatment of breast cancer 35 years old or under [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-07.

Objective The aim of this study was to identify the effectiveness and selective applications of preoperative magnetic resonance imaging (MRI) by investigating clinicopathologic factors of the index tumor with or without false lesions on MRI. Summary of background data Preoperative MRI is commonly performed in patients with newly diagnosed breast cancer, but its clinical significance is unclear. Methods A total of 103 breast cancer patients who had undergone MRI or ultrasound followed by mastectomy were included in this retrospective investigation of pathologic, clinical, and imaging findings. Results MRI showed 29 false-positive lesions in 57 patients, 5 false-negative lesions in 5 patients, and 69 true-positive lesions in 103 patients. More false lesions on MRI were found in patients with more lesions on ultrasound, small-sized index tumors on ultrasound, or early-stage cancer. The sensitivity of MRI and ultrasound were 96.5% and 92.3% (P = 0.119), respectively, and the positive predictive value of them were 71.5% and 72.5% (P = 0.828), respectively. Conclusions Preoperative MRI is more useful in patients with newly diagnosed breast cancer who have large-sized or more advanced cancers or fewer lesions on ultrasound.

Summary: Background: Sentinel lymph node (SLN) biopsy is an essential procedure for lymph node staging in patients with breast carcinoma. Technetium-99m-labelled nanocolloid (99mTc) is the most accurate and widely used lymphatic mapping agent; however, there are concerns pertaining to the associated exposure to radiation. Studies focusing on new agents are required. We aimed to evaluate the feasibility and safety of SLN detection using fluorescein and blue light-emitting diodes (LEDs) in breast carcinoma patients. Methods: In this prospective study, a total of 61 patients with breast carcinoma, requiring SLN biopsy, were enrolled. Both fluorescein and 99mTc were intradermally injected into the areola of the affected breast of each patient. SLNs stained with fluorescein were detected using blue LED light first, and then, any remaining SLNs were detected using a gamma detection probe. The detection rate was analyzed, and the presence of complications was investigated. Results: SLNs dyed with fluorescein using blue LED light were visualized in 57 of 61 patients (93.4%). None of the patients experienced complications related to the use of fluorescein or blue LED light. Conclusions: The detection of SLNs using fluorescein and blue LED light was feasible and safe in patients with breast carcinoma. This technique involves the use of visible light, allowing for SLNs to be viewed with the naked eye, and is quantifiable, easy to use, and economical. Keywords: Fluorescein, Breast carcinoma, Sentinel lymph node biopsy

Purpose. Phyllodes tumors (PTs) of the breast are rare fibroepithelial neoplasms, and factors associated with the recurrence of PTs are poorly understood. This study sought to identify clinicopathological factors associated with the recurrence of PTs. Method. From January 2009 to December 2019, we identified 100 patients who underwent definitive surgery for PT. Clinicopathological risk factors associated with the recurrence of PT were assessed. Results. The median age of the patients was 44 y (range, 19–62 y), and the median tumor size was 4 cm (0.8–30 cm). At a median follow-up of 26.7 mo (0–103 mo), 22 of the 100 patients experienced local recurrence. In the univariate and multivariate analyses, body mass index ≥ 23 kg/m2 ( P = 0.042 in the univariate analysis; P = 0.039 in the multivariate analysis), tumor size ≥ 5 cm ( P = 0.006 in the univariate analysis; P = 0.036 in the multivariate analysis), and the presence of stromal overgrowth ( P = 0.032 in the univariate analysis; P = 0.040 in the multivariate analysis) were associated with an increased risk of local recurrence. Resection margins and grade were not associated with local recurrence. Conclusion. Normal- or underweight patients and those with larger tumor sizes were more prone to local recurrence. Further larger, multicenter studies with a long-term follow-up are required.

The effective synthesis of two-dimensional (2D) heterostructures is essential for their use in electronic devices. In this study, by using atomic layer deposition (ALD), 2D transition metal dichalcogenide (TMD) heterostructures were grown by a halide precursor. This study shows the growth characteristics of the fluoride precursor compared to the chloride precursor used for the synthesis of the TMD on the graphene layer and the other TMD layer. Additionally, a carbonyl precursor was used for comparison with the halide precursor in terms of the thermal stability. From these experiments, the fluoride precursor was adequate for synthesizing on the graphene, however, was inappropriate for the TMD/TMD heterostructure because of its etching characteristic. Meanwhile, the chloride precursor was appropriate for the TMD/TMD heterostructure, even for a low binding energy with the substrate, but was inadequate in forming the TMD/graphene heterostructure, even if the ALD cycle increased. Through our experiments, we show, for the first time, that there exists a suitable halide precursor for a 2D layer for a substrate.

Around the world, governments turn to information technology (IT) training programs to enhance equitable delivery of online public services to citizens. However, the effectiveness of these citizen training programs has gone unexplored. This study is motivated by two objectives: 1) To evaluate whether citizen participation in government training programs is associated with greater e-government use among participants, and 2) To assess whether the strength of this relationship varies according to whether a citizen is elderly, disabled, or not – those who are elderly or disabled tend to use e-government the least. We use data from South Korean to examine these objectives. Findings indicate citizen participation in government IT training programs is positively associated with e-government use and that this relationship is stronger for citizens who are elderly or disabled. These findings highlight the potential of government IT training programs to mitigate the digital divide. Implications for research and practice are discussed.

Health services should be accessible regardless of citizens’ gender, age, race, or insurance type, and geographic barriers should not interfere with this access. This article aims to assess the heterogeneous impacts of geographic barriers on inpatients’ hospital choices and to examine whether they vary according inpatients’ socioeconomic or insurance status. Using data on providers and inpatients obtained from the New York State Bureau of Health Informatics Office of Quality and Patient Safety for New York County (New York City’s borough of Manhattan) for 2009, we employed a discrete choice model. Our findings reveal that geographic barriers limit inpatients’ choices of hospitals more when they are of low socioeconomic status.

Background: Many governments worldwide have committed to extending choices in public service delivery. However, the extent to which policies ensure equity is unclear. We investigated whether Medicaid programs in the United States improve hospital accessibility among patients with low socioeconomic status, compared to those with non-low socioeconomic status who are non-Medicaid recipients or uninsured.Methods: We employed a difference-in-difference-in-differences approach using a rich dataset of information on inpatients and their choice of hospitals from Statewide Planning Research and Cooperative System and information on hospitals from the American Hospital Association in Brooklyn, New York, from 2003 to 2009Results: The findings indicated that Medicaid has failed to broaden the range of the hospital choices for patients with low socioeconomic status, assessed in terms of bypassing behaviors. Conclusions: Medicaid is a public program that offers choices driven by purchasing power. The findings of this study imply that this program has some limitations in alleviating existing socioeconomic inequities in available hospital choices.

Aim Cancer stem-like cell (CSC) markers and the role of CSCs derived from papillary thyroid carcinoma (PTC) in pathogenesis are unclear. This study aimed to investigate CSC properties using tumor spheres from passaged PTC cells but without sorting CSCs. Materials and methods To identify the properties of CSCs derived from PTC, the expression of SRY-box transcription factor 2(SOX2), octamer-binding transcription factor 4 (OCT4), Nanog homeobox (NANOG), thyroglobulin (TG), thyroid-stimulating hormone receptor (TSHR), E-cadherin, YES-associated protein 1 (YAP1), and signal transducer and activator of transcription 3 (STAT3) was investigated in tumor spheres serially passaged without sorting CSCs. Results The cultured tumor spheres had cancer stemness; high expression of OCT4, SOX2, NANOG, and YAP1; low expression of E-cadherin; and varied expression of TG, TSHR, and STAT3. PTC tumor spheres transfected with small interfering RNA targeting YAP1 had fewer CSC properties than the non-transfected tumor spheres did. Conclusion Tumor spheres derived from PTC cells by passaging without sorting CSCs have more stem-like cell properties, and less differentiation potential. Thus, this simple and cost-effective method can be used for the enrichment of PTC stemness for employment in cell-based models, reducing the need for use of animal models.

DNA-based analyses of bacterial communities were performed to identify the bacteria co-occurring with cyanobacterial blooms in samples collected at a single site over 2 years. Microcystis aeruginosa was the most predominant species (81% in 2018, and 94% in 2019) within the phylum Cyanobacteria, and microcystins were detected during all cyanobacterial blooms. The stereo microscope and scanning electron microscope observations showed bacterial associations on and around the aggregated M. aeruginosa cells. Culture-independent analyses of filtered bacterial communities showed that the Flavobacterium species in phylum Bacteroidetes (19%) was dominant in the cyanobacterial phycosphere, followed by the Limnohabitans species in Betaproteobacteria (11%). Using principal component analysis, major bacterial genus, including Microcystis and Flavobacterium species, were clustered during cyanobacterial blooms in both years. To identify key bacterial species that develop long-term symbiosis with M. aeruginosa, another culture-independent analysis was performed after the environmental sample had been serially subcultured for 1 year. Interestingly, Brevundimonas (14%) was the most dominant species, followed by Porphyrobacter (7%) and Rhodobacter (3.5%) within the Alphaproteobacteria. Screening of 100 colonies from cyanobacterial bloom samples revealed that the majority of culturable bacteria belonged to Gammaproteobacteria (28%) and Betaproteobacteria (57%), including Pseudomonas, Curvibacter, and Paucibacter species. Several isolates of Brevundimonas, Curvibacter, and Pseudomonas species could promote the growth of axenic M. aeruginosa PCC7806. The sensitivity of M. aeruginosa PCC7806 cells to different environmental conditions was monitored in bacteria-free pristine freshwater, indicating that nitrogen addition promotes the growth of M. aeruginosa.

Friction and wear remain the primary cause of mechanical energy dissipation and system failure. Recent studies reveal graphene as a powerful solid lubricant to combat friction and wear. Most of these studies have focused on nanoscale tribology and have been limited to a few specific surfaces. Here, we uncover many unknown aspects of graphene's contact-sliding at micro- and macroscopic tribo-scales over a broader range of surfaces. We discover that graphene's performance reduces for surfaces with increasing roughness. To overcome this, we introduce a new type of graphene/silicon nitride (SiNx, 3 nm) bilayer overcoats that exhibit superior performance compared to native graphene sheets (mono and bilayer), that is, display the lowest microscale friction and wear on a range of tribologically poor flat surfaces. More importantly, two-layer graphene/SiNx bilayer lubricant (

This study investigates a social service voucher program in Korea to examine why local governments rely on external actors, such as for-profit and nonprofit organizations, in provisioning social se...

The aim of the study was to compare the efficacy and safety between an autocrosslinked polysaccharide (ACP) gel (Hyalobarrier) and a poloxamer/sodium alginate (P/SA: Guardix-SG) in preventing adhesions after thyroidectomy and demonstrate the noninferiority of ACP gel to P/SA. To identify differences of antiadhesive efficacy and safety between the ACP gel and P/SA, we investigated various variables such as the proportion of normal esophageal motility as assessed using marshmallow esophagography, swallowing impairment, adhesion severity and so on. This prospective, randomized, double-blinded, multicenter, phase III study investigated the antiadhesive efficacy and safety of ACP gel compared with those of P/SA for 12 weeks. Subjects were randomly assigned to receive either ACP gel (n = 97) or P/SA (n = 96). The primary endpoint was the proportion of normal esophageal motility as assessed using marshmallow esophagography, while the secondary endpoints included swallowing impairment, adhesion severity, laryngoscopic assessment of the vocal cords, and voice range profile. Safety endpoints included adverse events. There was no significant difference between the ACP gel and P/SA groups in the proportion of normal esophageal motility as the primary endpoint (P = 0.7428). In addition, there were no differences in the secondary or safety endpoints between the 2 groups. It was demonstrated that ACP gel was not inferior to P/SA. ACP gel appears both effective and safe for use in preventing adhesions after thyroidectomy.

Confocal and scanning electron microscopic observations have previously shown the strong bacterial association of Microcystis aeruginosa cells on their surfaces. DNA-based analyses of the associated bacterial communities were carried out using two M. aeruginosa strains grown in the laboratory and eight newly collected cyanobacterial bloom samples. M. aeruginosa was the most predominant species (66–100%) within the phylum Cyanobacteria. Rhizobium, Hydrogenophaga and Brevundimonas species were commonly found, and Flavobacterium species were present in all the cyanobacterial bloom samples. In total, 396 colonies from various samples were screened, revealing that most culturable bacteria belonged to the class Alphaproteobacteria (19%) including Rhizobium, Brevundimonas, and Porphyrobacter species. The genetic variation among the M. aeruginosa strains and different habitat conditions may have led to the presence of distinct bacterial populations among the tested samples. Among all the tested seven culturable isolates, Rhizobium sp. MK23 showed the best growth-promotion effect on the axenic M. aeruginosa strains. H2O2 was observed to be produced during the growth of M. aeruginosa PCC7806 under light conditions, this strain was more resistant to H2O2 when associated with Rhizobium sp. MK23. Our data suggested that Rhizobium species along with other associated bacteria might help the growth of M. aeruginosa by decomposing H2O2 under the aerobic growing conditions.

Axillary nodal status is one of the most important prognostic factors in breast cancer. The lymph node ratio (LNR) has been suggested as an independent prognostic factor because the number of dissected and involved lymph nodes might differ across institutions. Neoadjuvant chemotherapy (NAC) has been the preferred treatment method for reducing tumor mass in the breast and axillary area. However, NAC can reduce total number of excised lymph nodes compared with upfront surgery. Therefore, an emerging question is whether axillary nodal status and LNR following NAC can accurately predict prognosis. We evaluated the prognostic value of axillary nodal status and LNR after NAC. A total of 236 patients were enrolled. Patients were divided into four groups according to the following cut-off values for LNR: 0 (n = 107), 0.01–0.20 (n = 68), 0.21–0.65 (n = 50) and >0.65 (n = 11). Pathologic complete responses were observed in 16.9% of the overall cohort. In univariate analysis, pathologic N stage was a significant prognostic factor of disease free survival (DFS, p = 0.013) and overall survival (OS, p = 0.004). However, in multivariate analysis, hormone receptor status (p = 0.043) and LNR (p = 0.028) were significantly associated with DFS and LNR (p = 0.017) showed statistical significance for OS; however, pathologic N stage was no longer significantly associated with DFS or OS. Traditional nodal staging has been accepted as an important prognostic factor; however, our result indicated that the nodal ratio could be an alternative to pN staging as a prognostic factor after NAC in breast cancer. Keywords: Axilla, Breast, Neoadjuvant therapy, Lymph node, Survival

Background: Insulin receptor substrate 1 (IRS-1) has been known to be an associated factor with breast cancer progression. However, there has been little study with respect to the relationship between the expression of IRS-1 and breast cancer prognosis in clinical practice. In this study, we evaluated the impact of the estrogen receptor (ER) and IRS-1 on the recurrence and survival of breast cancer patients. Methods: We analyzed the pathologic finding of 376 tissue samples from breast cancer patients who received proper treatment between January 1990 and December 2006 using the tissue microarray. We measured the expression of ER and IRS-1 by immunohistochemistry staining and analyzed the difference of recurrence and survival rate in each subgroup of ER and IRS-1. Results: Our results show that there is a significant difference of disease-free survival (DFS) according to ER and IRS-1 subgroups with both univariate and multivariate analyses. Specifically, ER-positive and IRS-1-positive breast cancer samples showed improved DFS compared to ER-positive and IRS-1-negative breast cancer (adjusted hazard ratio: 2.17; 95% confidence interval: 1.15–4.09; P = 0.01). There was a difference of overall survival according to ER and IRS-1 subgroups by univariate analysis (P = 0.01), but not by multivariate analysis (P = 0.36). Conclusion: ER and IRS-1 subgroups appear to be critical factors for the prediction of breast cancer recurrence. In particular, we suggest that the patients who have ER-positive and IRS-1-negative breast cancer undergo more aggressive treatment because they have poorer prognoses.

A pair of flexible flags clamped vertically in a heated channel was numerically modeled to investigate the dynamics of the flexible flags and their effects on heat transfer enhancement. The penalty immersed boundary method was adopted to analyze the fluid–structure–thermal interaction between the surrounding fluid and the flexible flags. The flexible flags displayed three distinct movement modes: a flapping mode, a fully deflected mode, and an irregular mode that depended on the relationship between the hydrodynamic force and the restoring force. In the flapping mode, vortices shed from flexible flags merged and increased in magnitude. The merged vortical structures swept out the thermal boundary layer and enhanced thermal mixing between the fluid near the heated wall and the channel core flow. Compared to rigid flags, the flexible flags significantly improved the thermal efficiency. The effects of the bending rigidity, channel height, and Reynolds number on the thermal efficiency were observed, and an optimal parameter set was obtained. The presence of the flexible flags with the optimal parameter set resulted in an increase of up to 185% in the net heat flux and 106% in the thermal efficiency factor, compared to the baseline flow. The correlation between the vorticity and the temperature field was examined in detail using the dynamic mode decomposition (DMD) method.

Background/Objective: Conventional open thyroidectomy is considered as a safe surgery nowadays. However, surgeons sometimes encounter unexpected difficulty when performing thyroidectomies. The aim of this paper was to identify the predictors of a difficult thyroidectomy for the management of patients with papillary thyroid carcinoma. Methods: A database of patients who underwent open conventional thyroidectomy with cervical lymph node dissection after diagnosed papillary thyroid carcinoma between July 2008 and June 2013 was examined. In addition, the patients were subgrouped by difficult thyroidectomy (DT) and nondifficult thyroidectomy to determine the predictors of DT according to operation time. Clinicopathologic characteristics, surgical outcomes, and postoperative morbidities were investigated. Results: No between-group differences in clinicopathologic factors and postoperative complications, except for male sex (p

Broadband detection of mid-infrared (IR) photons extends to advanced optoelectronic applications such as imaging, sensing, and telecommunications. While graphene offers an attractive platform for broadband visible/IR photodetection, previous efforts to improve its responsivity, for example, by integrating light-absorbing colloids or waveguide or antenna fabrication, were achieved at the cost of reduced photon detection bandwidth. In this work, we demonstrate room-temperature operation of a novel mid-IR photodetector based on a graphene–Bi2Se3 heterostructure showing broadband detection and high responsivity (1.97 and 8.18 A/W at mid- and near-IR, respectively), in which simultaneous improvement of the spectral range and responsivity is achieved via exploiting broadband absorption of mid-IR and IR photons in a small-band-gap Bi2Se3 topological insulator and efficient hot carrier separation and strong photogating across the Bi2Se3/graphene interface. With sufficient room for further improvement by interface...

The brake systems are composed of brake disc, brake pad and caliper and, these three parts play an important role for braking. In this study, heat fluid analysis is conducted for five different ventilated disc models, and two piece brake disc model separated in rotor and housing is used. In this case, each model has a different number of holes and vent shape. The basic heat flux and braking power equations are applied for the heat fluid analysis. The cooling performance with/without the braking operation is also analyzed for given five models where the material properties and boundary conditions are set to be identical. From our analysis results, it is found that the number of disc holes and ventilated pins strongly influences on the cooling performance.

The objective was to identify gene expression profile of papillary thyroid microcarcinoma. To help improve diagnosis of papillary thyroid microcarcinoma, we performed gene expression profiling and compared it to pair normal thyroid tissues. We performed microarray analysis with 6 papillary thyroid microcarcinoma and 6 pair normal thyroid tissues. Differentially expressed genes were selected using paired t test, linear models for microarray data, and significance analysis of microarrays. Real-time quantitative reverse transcription–polymerase chain reaction was used to validate the representative 10 genes (MET, TIMP1, QPCT, PROS1, LRP4, SDC4, CITED1, DPP4, LRRK2, RUNX2). We identified 91 differentially expressed genes (84 upregulated and 7 downregulated) in the gene expression profile and validated 10 genes of the profile. We identified a significant genetic difference between papillary thyroid microcarcinoma and normal tissue by 10 upregulated genes greater than 2-fold (P < 0.05).

Harmful cyanobacterial bloom (HCB) by Microcystis aeruginosa is increasingly becoming a serious concern to the environment and human health alike. Currently, many physical, chemical, and biological controls are underway to eliminate HCB, but natural chemicals are rarely used. To find a control agent with low environmental toxicity and high potential for practical use, 60 plant extracts were screened. Only Selaginella tamariscina extract killed all four Microcystis aeruginosa strains, but not the other tested bacteria. Chloroform fraction of S. tamariscina extract (CSE) showed the highest killing activity. The effects of CSE on M. aeruginosa were monitored using differential interference contrast microscopy and flow-cytometry analysis, scanning electron microscopy, and transmission electron microscopy. The images showed that CSE-treated cells were abnormally altered, with damaged cell membranes, peptidoglycan layers, and cytoplasm. Quadrupole time-of-flight liquid chromatography-mass spectrometry was used to identify amentoflavone as a major active compound. Pure amentoflavone, even at low concentrations showed a powerful killing effect on M. aeruginosa, but not on other non-cyanobacteria. Overall, in this study, we have highlighted the potentials of S. tamariscina extracts and amentoflavone as selective HCB control agents.

Functional van der Waals heterojunctions of transition metal dichalcogenides are emerging as a potential candidate for the basis of next-generation logic devices and optoelectronics. However, the complexity of synthesis processes so far has delayed the successful integration of the heterostructure device array within a large scale, which is necessary for practical applications. Here, a direct synthesis method is introduced to fabricate an array of self-assembled WSe

The interfacial properties of organolead halide perovskite solar cells (PSCs) affect the exciton and charge-transport dynamics significantly. Thus, proper modification of the interfaces between perovskite and charge-transport layers is an efficient method to increase the power conversion efficiency (PCE) of PSCs. In this work, we explore the effect of a nonionic surfactant, that is, Triton X-100 (TX) additive, in the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) hole-transport layer. The electronic structure of TX-modified PEDOT:PSS is investigated with ultraviolet/X-ray photoelectron spectroscopy and X-ray absorption spectroscopy with various TX concentrations. The surface of the TX-modified PEDOT:PSS layer showed high TX content, and thus the semimetallic properties of PEDOT:PSS were suppressed conspicuously by its insulating nature. With the TX-modified PEDOT:PSS, the PCE of methylammonium lead iodide (MAPbI3) PSCs increased significantly. To elucidate the origin of the improved device performance, the electrical properties and photoluminescence were investigated comprehensively. Consequently, it was found that the TX additive inhibits interface recombination between PEDOT:PSS and MAPbI3, which is caused by the suppression of semimetallic properties of the PEDOT:PSS surface. Hence, we fabricated flexible PSCs successfully using a graphene electrode and TX-modified PEDOT:PSS.

Stretchable alternating-current electroluminescent (ACEL) devices are required due to their potential in wearable, biomedical, e-skin, robotic, lighting, and display applications; however, one of the main hurdles is to achieve uniform electroluminescence with an optimal combination of transparency, conductivity, and stretchability in electrodes. We therefore propose a fabrication scheme involving strategically combining two-dimensional graphene layers with a silver nanowire (Ag NW)-embedded PEDOT:PSS film. The developed hybrid electrode overcomes the limitations of commonly known metallic NWs and ionic conductor-based electrodes for ACEL applications. Furthermore, the potential of the hybrid electrode is realized in demonstrating large-area stretchable ACEL devices composed of an 8 × 8 passive array. The prototype ACEL passive array demonstrates efficient and uniform electroluminescence under high levels of mechanical deformation such as bending, rolling, twisting, and stretching.

Summary: Background: Robotic thyroidectomy is increasingly used for patients with papillary thyroid carcinoma (PTC). We compared the differences between robotic and endoscopic transaxillary thyroidectomy with regard to surgical procedures. Methods: This retrospective study enrolled 40 patients with PTC who underwent robotic hemithyroidectomy (robot group) using the Da Vinci S system and 37 patients (endoscopic group) who underwent endoscopic hemithyroidectomy. Video files of surgery for all patients were analyzed to compare the operation procedures: (flap creation, docking [only for robot group], dissection of the superior pole, dissection of the inferior pole, identification of parathyroid glands [PTGs] and the recurrent laryngeal nerve [RLN], dissection of the thyroid along the trachea, bleeding control, application of a drain, and wound closure). The duration of each procedure and the clinicopathological characteristics were analyzed. Results: Procedure time for patients in the robot group was shorter for inferior pole dissection and for identification of the PTGs and RLN (37.5 min vs. 50.5 min, p = 0.008). Mean total operative times for the two groups were comparable (153.0 min vs. 150.2 min, p = 0.732); however, excluding the docking procedure, operation time was shorter for the robot group (133.3 min vs. 150.2 min, p = 0.038). The number of sacrificed PTGs was also significantly smaller in the robot group (0.35 ± 0.53 vs. 0.65 ± 0.68, p = 0.036). Conclusion: Compared to endoscopic thyroidectomy, robotic transaxillary thyroidectomy involved a shorter time for inferior pole dissection and PTGs and RLN identification; moreover, more PTGs were spared using this procedure. Keywords: Endoscopic thyroidectomy, Papillary thyroid carcinoma, Robotic thyroidectomy

Background Robotic surgical systems have evolved over time. The da Vinci Xi system was developed in 2014 and was expected to solve the shortcomings of the previous S system. Therefore, we conducted this study to compare these two systems and identify if the Xi system truly improves surgical outcomes. Methods In this retrospective study, a total of 86 patients with unilateral papillary thyroid carcinoma without central lymph node involvement underwent gasless transaxillary hemithyroidectomy using two robotic systems, the da Vinci S and Xi. Forty patients were in the da Vinci S group and 46 patients were in the da Vinci Xi group. All surgeries were performed by one surgeon (YWC). All surgery video files were analyzed to compare the duration of each surgical step. Results The total operation time was significantly shorter in the Xi group than in the S group (153.0 min vs. 105.7 min, p

Purpose Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM). Methods Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device. We also analyzed demographic information, pathology, operative time, and complications. Results No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications. Conclusion The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

Summary Background Central lymph node dissection (CLND) in patients with papillary thyroid microcarcinoma (PTMC) is still controversial. The aim of this study was to examine the risk factors and the incidence of central lymph node metastases (CLNMs) in patients with PTMC who underwent thyroidectomy and CLND. Patients and methods Between 2002 and 2013, 613 patients were enrolled who underwent thyroidectomy with routine CLND for PTMC at the Korea University Medical Center, Ansan Hospital and risk factors and the incidence of CLNM were analyzed. In addition, we also evaluated the complications after thyroidectomy with CLND. Results Out of 613 patients, 239 (39.0%) were found to have CLNM. Male sex ( p = 0.012), tumor size ≥ 0.5 cm ( p = 0.001), capsular invasion or extrathyroidal extension ( p = 0.029), and multifocality ( p = 0.004) were independent risk factors for CLNM. Among the 69 patients who had PTMC without these risk factors, CLNM was identified in 12 (17.4%). In this study group, two (0.3%) had permanent recurrent laryngeal nerve injury, two (0.3%) had persistent hypocalcemia, and two (0.3%) developed postoperative hemorrhage. Conclusion CLNM in PTMC is highly prevalent in male sex, tumor size ≥ 0.5 cm, extrathyroidal extension, and multifocality. Even in PTMC patients without these risk factors, the incidence of CLNM is rather higher than expected, and the complication rate of thyroidectomy with CLND is acceptable. Thus, CLND should be considered in all patients with PTMC.

Application-oriented patterned growth of transition metal dichalcogenides (TMDCs) and their heterojunctions is of critical importance for sophisticated, customized two-dimensional (2D) electronic and optoelectronic devices; however, it is still difficult to fabricate these patterns in a simple, clean, and high controllability manner without using optical lithography. Here, we report the direct synthesis of patterned MoS2 and graphene-MoS2 heterojunctions via selective plasma treatment of a SiO2/Si substrate and chemical vapor deposition of MoS2. This method has multiple merits, such as simple steps, a short operating time, easily isolated MoS2 layers with clean surfaces and controllable locations, shapes, sizes and thicknesses, which enable their integration into the device structure without using a photoresist. In addition, we demonstrate the direct growth of patterned graphene-MoS2 heterojunctions for the fabrication of transistor. This study reveals a novel method to fabricate and use patterned MoS2 and graphene-MoS2 heterojunctions, which could be generalized to the rational design of other 2D materials, heterojunctions and devices in the future.