Spin angular momentum-encoded single-photon emitters in a chiral nanoparticle-coupled WSe2 monolayer

Spin angular momentum (SAM)-encoded single-photon emitters, also known as circularly polarized single photons, are basic building blocks for the advancement of chiral quantum optics and cryptography. Despite substantial efforts such as coupling quantum emitters to grating-like optical metasurfaces and applying intense magnetic fields, it remains challenging to generate circularly polarized single photons from a subwavelength-scale nanostructure in the absence of a magnetic field. Here, we demonstrate single-photon emitters encoded with SAM in a strained WSe2 monolayer coupled with chiral plasmonic gold nanoparticles. Single-photon emissions were observed at the nanoparticle position, exhibiting photon antibunching behavior with a g(2)(0) value of ~0.3 and circular polarization properties with a slight preference for left-circular polarization. Specifically, the measured Stokes parameters confirmed strong circular polarization characteristics, in contrast to emitters coupled with achiral gold nanocubes. Therefore, this work provides potential insights to make SAM-encoded single-photon emitters and understand the interaction of plasmonic dipoles and single photons, facilitating the development of chiral quantum optics.

Controlled Crystallinity of a Sn-Doped α-Ga2O3 Epilayer Using Rapidly Annealed Double Buffer Layers

Double buffer layers composed of (AlxGa1-x)2O3/Ga2O3 structures were employed to grow a Sn-doped α-Ga2O3 epitaxial thin film on a sapphire substrate using mist chemical vapor deposition. The insertion of double buffer layers improved the crystal quality of the upper-grown Sn-doped α-Ga2O3 thin films by blocking dislocation generated by the substrates. Rapid thermal annealing was conducted for the double buffer layers at phase transition temperatures of 700-800 °C. The slight mixing of κ and β phases further improved the crystallinity of the grown Sn-Ga2O3 thin film through local lateral overgrowth. The electron mobility of the Sn-Ga2O3 thin films was also significantly improved due to the smoothened interface and the diffusion of Al. Therefore, rapid thermal annealing with the double buffer layer proved advantageous in achieving strong electrical properties for Ga2O3 semiconductor devices within a shorter processing time.

Normal mode analysis in multi-coupled non-Hermitian optical nanocavities

Coupled optical cavities are an attractive on-chip optical platform for realizing quantum mechanical concepts in electrodynamics and further developing non-Hermitian photonics. In such systems, an intercavity interaction is often considered as a key parameter to understand the system's behaviors but its estimation/calculation is typically limited for some simplified systems owing to extended complexities. For example, multi-coupled photonic crystal (PhC) nanocavities exhibiting strong resonances with a large free spectral range can serve as an excellent test-bed to study non-Hermitian optical properties when spatially non-uniform gain is introduced. However, the detailed quantitative analysis such as spectral tracing of cavity normal modes is often limited in commercially available numerical tools because of the required massive computation resources. Herein, we report on a concept of spatial overlap integrals (SOIs) between the eigenmodes in non-coupled PhC nanocavities and utilize them to obtain the intercavity interactions in passively coupled PhC nanocavity systems. With the help of coupling strength factors calculated from SOIs, we were able to fully exploit the coupled mode theory (CMT) and readily trace the detailed spectral behaviors of normal modes in various multi-coupled PhC nanocavities. Full-wave numerical simulation results verified the proposed method, revealing that the characteristics of original eigenmodes from non-coupled PhC nanocavities can act as key building blocks for analyzing the normal modes of multi-coupled PhC nanocavities. We further applied this SOI method to various multi-coupled PhC nanocavities with non-symmetric optical gain/loss distributions and successfully observed the unusual spectral evolution of normal modes and the correspondingly occurring unique non-Hermitian behaviors.

The Feasibility of Fast, Four-Dimensional Computed Tomography-Based O-Ring Linac Plans for Stereotactic Body Radiotherapy in Patients with Poor Performance Status

PURPOSE/OBJECTIVE(S)

As patients with poor performance status cannot endure long treatment times, it can lead to unplanned and prolonged radiation treatment or discontinuation of treatment. Moreover, prolonged radiation treatment appears to negatively affect survival for patients. We aimed to verify the feasibility of fast 4DCT-based O-ring linear accelerator (LINAC) treatment in lung 4D stereotactic body radiotherapy (SBRT).

MATERIALS/METHODS

This study included data of 38 patients who received lung 4D-SBRT. Gating20-70% plans were based on 4DCT data obtained at phase values ranging from 20-70% using a C-arm LINAC. Non-GatingFB plans were retrospectively established based on 4DCT data obtained at phase values of 0-90% using an O-ring LINAC. The prescribed dose of 4,800 cGy was delivered to PTV in four fractions. The conformity index (CI), homogeneity index (HI), and gradient measurement (GM) of the PTV were analyzed to compare dosimetric data between Gating20-70% and Non-GatingFB plans. Organs at risks (OARs) were analyzed in accordance with the RTOG 0915 protocol. Treatment delivery time and total monitor units (MU) were analyzed to compare the efficiency of treatment delivery. Statistical comparisons were performed using the Wilcoxon signed-rank test (p<0.05).

RESULTS

For the PTV, there was no significant difference in the CI or HI between Gating20-70% and Non-GatingFB plans (CI: 1.337±0.137, 1.335±0.174, HI: 0.939±0.015, 0.939±0.016, all at p>0.05). However, there was a significant difference in GM between Gating20-70% and Non-GatingFB plan (1.528±0.206 cm, 1.381±0.222 cm, p<0.001). For OARs, all plans met the criteria for dose constraint. There was a significant difference between Gating20-70% and Non-GatingFB plans except in the spinal cord. In particular, D1000cc and D1500cc values for the ipsilateral lung for Gating20-70% plans were 31.6% and 59.9% lower than those for Non-GatingFB plans (D1000cc: 50.780±132.061 cGy, 34.755±102.480 cGy, p<0.001, D1500cc: 6.641±14.598 cGy, 2.666±7.926 cGy, p<0.001). Treatment delivery time was 92% longer for Gating20-70% plans than for Non-GatingFB plans (5.0±0.4 min, 9.6±3.3 min, p = 0.043). The total MU value for Gating20-70% plans was 9.6% higher than that for Non-GatingFB plans (3665.8±230.7, 4016±236.9, p = 0.039).

CONCLUSION

When compared to OARs both plans were acceptable per RTOG-0915 protocol, but significant differences were between Non-GatingFB and Gating20-70% plans. However, treatment delivery time of Non-GatingFB plans decreased by 47.9% than Gating20-70% plans. We verified the feasibility of fast 4DCT-based O-ring LINAC treatment for patients who cannot endure long treatment times due to poor performance status in lung 4D-SBRT. In further study, we will analyze dosimetric differences and treatment delivery efficiency considering tumor motion according to tumor location.

Mapping the Anatomical Distribution of MRI-Identified Locoregional Recurrence following Robotic-Assisted Laparoscopic Prostatectomy for Prostate Adenocarcinoma

PURPOSE/OBJECTIVE(S)

The pattern of locoregional recurrence specifically after robotic-assisted laparoscopic prostatectomy (RALP) for prostate adenocarcinoma is still unknown. In this study, we reviewed pelvic magnetic resonance images (MRI) after postoperative biochemical recurrence (BCR) and drew a map of locoregional recurrence to support evidence of determining the optimal target volume of salvage radiotherapy in a post-RALP BCR scenario.

MATERIALS/METHODS

We have retrospectively searched 7,583 prostate adenocarcinoma patients who have received RALP in our institution between January 2010 and December 2021, and found a pool of highly selected patients with gross tumor recurrence confirmed by post-BCR pelvic MRIs and did not have other histories of malignancy. BCR was defined as the serum PSA more or equal to 0.2 ng/mL, or three consecutive increases. Patients with serum PSA nadir more or equal to 0.2 ng/mL on the 90th postoperative day (POD 90) were excluded to guarantee successful tumor removal. We have reviewed serum PSA levels using R codes, MRI and pathological reports using Excel, and descriptive statistics using SPSS 25. The gross lesions were contoured on the correlating MRIs using MIM Maestro 7.1. The RT structure DICOM files were merged into a map using MATLAB 2022b. In addition, we have conducted Fisher exacted test, Mann-Whitney U test, and logistic regression to identify risk factors for regional recurrence.

RESULTS

A total of 173 patients were identified with locoregional recurrence from post-BCR pelvic MRIs, and 139 (80.3%) patients were in the high-risk group or very-high-risk group according to the NCCN guidelines: 57 (32.9%) patients with histological grade group 5, 50 (28.9%) patients with initial PSA over 20 ng/mL, 114 (65.9%) patients with extracapsular extension, 55 (31.8%) patients with seminal vesicle invasion, and 15 (9%) patients with pN1. The median follow-up was 4.7 (IQR 2.8-6.9) years for pelvic MRIs and 5.8 (IQR 4.0-8.6) years for serum PSA. The BCF survival was median of 10.7 (IQR 4.6-19.1) months, and the locoregional recurrence-free survival was median of 24.6 (IQR 9.7-49.4) months for this subgroup of patients. At first locoregional recurrence, 148 (85.5%) patients were local only, 20 (11.6%) patients were regional only, and 5 (2.9%) patients were both local and regional. Out of the 25 patients with regional recurrence, the incidence of gross tumor recurrence differed by nodal sites: 3 (12%) in perirectal space, 5 (20%) in internal iliac, 7 (28%) in obturator, 13 (52%) in external iliac, and 6 (24%) in common iliac lymph nodes.

CONCLUSION

We have found 173 patients and were able to map reliable gross tumor recurrence sites after RALP and confirmed by pelvic MRIs following BCR. The map supports evidence of using the existing consensus pelvic clinical target volume of salvage radiotherapy, in a post-RALP BCR scenario.

Prediction of Lymphopenia and Survival with Baseline Absolute Lymphocyte Count and Irradiated Dose to Immune Cells in Patients with Non-Small Cell Lung Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to investigate the effect of effective dose to immune cell (EDIC) combined with pre-radiotherapy (RT) absolute lymphocyte count (ALC) on treatment-related lymphopenia during RT and treatment outcome in patients with locally advanced non-small cell lung cancer (NSCLC). A subgroup analysis in patients who received consolidation immunotherapy was also conducted.

MATERIALS/METHODS

Between August 2008 and December 2021, 517 patients with locally advanced NSCLC treated with definitive concurrent chemoradiotherapy (CRT) were retrospectively analyzed. All patients had serial complete-blood-count tests at pre-, and during-CRT. Severe lymphopenia was defined as ALC < 0.5x109cells/L during RT. EDIC was calculated according to mean doses of the lung, heart and the total body. The patients were grouped according to high and low EDIC and pre-RT ALC and was assessed for its correlation with radiation induced lymphopenia and survival outcomes.

RESULTS

Of 517 eligible patients, most of the patients received weekly paclitaxel with carboplatin (90.3%) and 195 patients (37.7%) received consolidation immunotherapy following CRT. A median radiation dose of 63 Gy (IQR, 60-64.5) was delivered in 30 fractions. The optimal cutoff value of EDIC and pre-RT ALC for predicting severe lymphopenia were 2.89 Gy and 2.03x109cells/L, respectively. High risk group was defined as EDIC ≥ 2.89 Gy and pre-RT ALC < 2.03x109cells/L, low risk group as EDIC <2.89 Gy and pre-RT ALC ≥ 2.03x109cells/L, and intermediate group as EDIC ≥ 2.89 Gy and pre-RT ALC ≥ 2.03x109cells/L or EDIC < 2.89 Gy and pre-RT ALC < 2.03x109cells/L. The incidence of severe lymphopenia during RT in high, intermediate, and low risk group was 90.1%, 77.1%, and 52.3%, respectively (p<0.001). The risk groups were independent predictors for both progression-free survival (PFS) (p<0.001) and overall survival (OS) (p<0.001). The high-risk group had higher incidence of locoregional and distant recurrences (p<0.001). In the subset of patients who were treated with consolidation immunotherapy, the risk groups were predictive of severe lymphopenia (p = 0.001), PFS (p = 0.004), and OS (p = 0.012).

CONCLUSION

This study demonstrated that the combination of EDIC and pre-RT ALC is a predictor for severe lymphopenia during RT, recurrence, and survival in patients with locally advanced NSCLC who received CRT. Moreover, the combination of EDIC and pre-RT ALC may serve as a potential biomarker for the benefit of maintenance immunotherapy.

Single-incision robotic colorectal surgery with the da Vinci SP® surgical system: initial results of 50 cases

PURPOSE

The da Vinci SP® (dVSP) surgical system (Intuitive Surgical, Sunnyvale, CA, USA), a robotic platform designed for single-incision surgery, overcame the need for multiple ports in traditional robotic surgery and issues including triangulation and retraction in single-incision laparoscopic surgery. However, previous studies only included case reports or series with small sample sizes. The aim of this study was to assess the safety and performance of the dVSP surgical system and its instruments and accessories for colorectal procedures.

METHODS

The medical records of patients who had surgery with the dVSP from March 2019 to September 2021 at Ewha Womans University Seoul Hospital were investigated. The pathologic and follow-up data of patients who had malignant tumors were analyzed separately to evaluate oncological safety.

RESULTS

Fifty patients (26 male and 24 female) with a median age of 59 years (interquartile range 52.5-63.0 years) were enrolled. The procedures included low anterior resection with total mesorectal excision (n = 16), sigmoid colectomy with complete mesocolic excision and central vessel ligation (CME + CVL) (n = 14), right colectomy with CME + CVL (n = 9), left colectomy with CME + CVL (n = 4), right colectomy (n = 6), and sigmoid colectomy (n = 1). Operative time significantly decreased after 25 cases (early phase vs. late phase; operative time 295.0 min vs. 250.0 min, p = 0.015; docking time 16.0 min vs. 12.0 min, p = 0.001; console time 212.0 min vs. 190.0 min, p = 0.019). Planned procedures were successfully completed in all patients. Postoperative outcomes were acceptable with only six cases of mild adverse events through a 3-month follow-up. No local recurrence and only one case of systemic recurrence occurred within 1 year postoperatively.

CONCLUSIONS

This study demonstrated the surgical and oncological safety and feasibility of dVSP, which may be a novel surgical platform for colorectal surgery.

Optical Nonlinearity in Silicon Nanowires Enabled by Bound States in the Continuum

Intense electromagnetic fields localized within resonant photonic nanostructures provide versatile opportunities for engineering nonlinear optical effects on a subwavelength scale. For dielectric structures, optical bound states in the continuum (BICs, resonant nonradiative modes that exist within the radiation continuum) are an emerging strategy to localize and intensify fields. Here, we report efficient second and third harmonic generation from Si nanowires (NWs) encoded with BIC and quasi-BIC resonances. In situ dopant modulation during vapor-liquid-solid NW growth was followed by wet-chemical etching to periodically modulate the diameter of the Si NWs and create cylindrically symmetric geometric superlattices (GSLs) with precisely defined axial and radial dimensions. By variation of the GSL structure, BIC and quasi-BIC resonant conditions were created to span visible and near-infrared optical frequencies. To probe the optical nonlinearity of these structures, we collected linear extinction spectra and nonlinear spectra from single-NW GSLs, demonstrating that quasi-BIC spectral positions at the fundamental frequency are directly correlated with enhanced harmonic generation at second and third harmonic frequencies. Interestingly, we find that deliberate geometric detuning from the BIC condition leads to a quasi-BIC resonance with maximal harmonic generation efficiency by providing a balance between the capacity to trap light and the capacity to couple to the external radiation continuum. Moreover, under focused illumination, as few as 30 geometric unit cells are required to achieve more than 90% of the approximate maximum theoretical efficiency of an infinite structure, indicating that nanostructures with projected areas smaller than ∼10 μm² can support quasi-BICs for efficient harmonic generation. The results represent an important step toward the design of efficient harmonic generation at the nanoscale and further highlight the photonic utility of BICs at optical frequencies in ultracompact one-dimensional nanostructures.

Broadband generation of quasi bound-state-in-continuum modes using subwavelength truncated cone resonators

To allow a high quality factor (Q-factor) to a sub-wavelength dielectric resonator, quasi-bound states in the continuum (Q-BICs) have gained much interest. However, the Q-BIC resonance condition is too sensitive to the geometry of the resonator, and its practical broadband generation on a single-wafer platform has been limited. Here we present that, employing the base angle as a structural degree of freedom, the truncated nano-cone resonator supports the Q-BIC resonance with a high Q-factor of >150 over a wide wavelength range of >100 nm. We expect our approach will boost the utilization of the Q-BIC resonance for various applications requiring broadband spectral tuning.

A supervised machine learning approach to discriminate the effect of carcass leachate on shallow groundwater quality around on-farm livestock mortality burial sites

The evaluation of leachate leakage at livestock mortality burial sites is challenging, particularly when groundwater is previously contaminated by agro-livestock farming. Supervised machine learning was applied to discriminate the impacts of carcass leachate from pervasive groundwater contamination in the following order: data labeling, feature selection, synthetic data generation, and classification. Physicochemical data of 359 water samples were collected from burial pits (LC), monitoring wells near pits (MW), pre-existing shallow household wells (HW), and background wells with pervasive contamination (BG). A linear classification model was built using two representative groups (LC and BG) affected by different pollution sources as labeled data. A classifier was then applied to assess the impact of leachate leakage in MW and HW. As a result, leachate impacts were observed in 40% of MW samples, which indicates improper construction and management of some burial pits. Leachate impacts were also detected in six HW samples, up to 120 m downgradient, within one year. The quantitative decision-making tool to diagnose groundwater contamination with leachate leakage can contribute to ensuring timely responses to leakage. The proposed machine learning approach can also be used to improve the environmental impact assessment of water pollution by improper disposal of organic waste.

Nanograin network memory with reconfigurable percolation paths for synaptic interactions

The development of memory devices with functions that simultaneously process and store data is required for efficient computation. To achieve this, artificial synaptic devices have been proposed because they can construct hybrid networks with biological neurons and perform neuromorphic computation. However, irreversible aging of these electrical devices causes unavoidable performance degradation. Although several photonic approaches to controlling currents have been suggested, suppression of current levels and switching of analog conductance in a simple photonic manner remain challenging. Here, we demonstrated a nanograin network memory using reconfigurable percolation paths in a single Si nanowire with solid core/porous shell and pure solid core segments. The electrical and photonic control of current percolation paths enabled the analog and reversible adjustment of the persistent current level, exhibiting memory behavior and current suppression in this single nanowire device. In addition, the synaptic behaviors of memory and erasure were demonstrated through potentiation and habituation processes. Photonic habituation was achieved using laser illumination on the porous nanowire shell, with a linear decrease in the postsynaptic current. Furthermore, synaptic elimination was emulated using two adjacent devices interconnected on a single nanowire. Therefore, electrical and photonic reconfiguration of the conductive paths in Si nanograin networks will pave the way for next-generation nanodevice technologies.

Rasiella rasia gen. nov. sp. nov. within the family Flavobacteriaceae isolated from seawater recirculating aquaculture system

A novel bacterium designated RR4-40^T was isolated from a biofilter of seawater recirculating aquaculture system in Busan, South Korea. Cells are strictly aerobic, Gram-negative, irregular short rod, non-motile, and oxidase- and catalase-negative. Growth was observed at 15-30°C, 0.5-6% NaCl (w/v), and pH 5.0-9.5. The strain grew optimally at 28°C, 3% salinity (w/v), and pH 8.5. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain RR4-40^T was most closely related to Marinirhabdus gelatinilytica NH83^T (94.16% of 16S rRNA gene similarity) and formed a cluster with genera within the family Flavobacteriaceae. The values of the average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) between genomes of strain RR4-40^T and M. gelatinilytica NH83^T were 72.91, 18.2, and 76.84%, respectively, and the values against the strains in the other genera were lower than those. The major fatty acids were iso-C_15:0 (31.34%), iso-C_17:0 3-OH (13.65%), iso-C_16:0 3-OH (10.61%), and iso-C_15:1 G (10.38%). The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid, aminolipid, glycolipid, and sphingolipid. The major respiratory quinone was menaquinone-6 (MK-6) and the DNA G + C content of strain RR4-40^T was 37.4 mol%. According to the polyphasic analysis, strain RR4-40^T is considered to represent a novel genus within the family Flavobacteriaceae, for which the name Rasiella rasia gen. nov, sp. nov. is proposed. The type strain is RR4-40^T (= KCTC 52650^T = MCCC 1K04210^T).

SGO and the elephant that is still in the room: Wellness, burnout and gynecologic oncology

OBJECTIVE

To measure wellness and burnout among gynecologic oncology clinicians and identify trends and at-risk populations to inform future interventions.

METHODS

Gynecologic oncologist (GO) and advanced practice provider (APP) responses to the 2020 Society of Gynecologic Oncology State of the Society survey were analyzed. The Maslach Burnout Inventory criteria for burnout was used. Work-life balance was scored on a 5-point Likert scale. Chi-square tests were used to compare mental health factors and the prevalence of burnout. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for associations between burnout and gender.

RESULTS

543 survey responses were included for analysis. Most GO (54%) and all APP respondents were female. Female GOs were disproportionately affected by burnout particularly in the Northeast (female(F): 40.9% vs male(M): 19.1%, p = 0.007) and South (F: 42.5% vs M:22.9%, p = 0.01). Burnout in female GOs over 40 was 1.79 (CI: 1.13-2.83; p-value 0.01) times higher than similarly aged males. Females in non-private practice experienced burnout 1.66 times that of males in similar positions (CI: 1.18-2.94; p < 0.0001). Female GOs reported the worst work-life balance across all 5 domains. APPs and female GOs experienced more stress and feeling overwhelmed compared to men. GOs were more reluctant to see a mental health professional (p = 0.0003) or take medication (p = 0.009) than APPs.

CONCLUSIONS

Burnout in gynecologic oncology persists in both genders and is felt most acutely by female GOs. APPs are not immune and would benefit from inclusion in future research to mitigate burnout in healthcare clinicians.

Genetic and clinical characteristics of transthyretin cardiac amyloidosis in Koreans

Background/Introduction

Transthyretin amyloidosis with mutations (aTTRv amyloidosis) have over 100 recognized pathogenic mutations of the TTR gene and its clinical manifestations are very heterogenous. Through the global THAOS (Transthyretin Amyloidosis Outcomes Survey) patient registry, different and several types of mutants and clinical differences have been identified. Awareness of aTTRv amyloidosis is now becoming somewhat significant amongst physicians all over the world. This is a detailed look at such efforts in Korea.

Purpose

We aimed to seek the geologic significance of aTTRv amyloidosis in South Korea.

Methods

This was an analysis of 638 Korean amyloidosis patients in a single center over a period of 16 years from 1995 to October 2021. 95 individuals were found with aTTR mutations.

Results

aTTRv amyloidosis constituted 14.8% (n=95) of amyloidosis patients, and the most commonly involved organ being the heart (61.7%, n=58). Unlike the rest of the world, the mixed phenotype was most common (51.0%, n=48) in Korea and the most universal mutation in Koreans were Asp38Ala, which only constitutes about 1.0% in the THAOS registry. Val30Met mutation, which comprises 76% of the mutation in the THAOS registry, was mostly associated the neurologic phenotypes. However, the same mutations in Korea mixed phenotypes with cardiac (38.4%) and neurologic (37%) symptoms.

Conclusion

aTTRv amyloidosis in Korea is different from other patients worldwide. The mixed phenotype was most common, emphasizing the need for heart failure management in the Korean population. Genotype wise, Koreans held a less common mutation of Asp38Ala. The most common mutation of Val30Met was more likely to be associated cardiac symptoms, which concurs with other studies that suggesting that geological features are more important than mutations itself.

Funding Acknowledgement

Type of funding sources: None.

Efficient Photon Extraction in Top-Emission Organic Light-Emitting Devices Based on Ampicillin Microstructures

The desire to enhance the efficiency of organic light-emitting devices (OLEDs) has driven to the investigation of advanced materials with fascinating properties. In this work, the efficiency of top-emission OLEDs (TEOLEDs) is enhanced by introducing ampicillin microstructures (Amp-MSs) with dual phases (α-/β-phase) that induce photoluminescence (PL) and electroluminescence (EL). Moreover, Amp-MSs can adjust the charge balance by Fermi level (E_F ) alignment, thereby decreasing the leakage current. The decrease in the wave-guided modes can enhance the light outcoupling through optical scattering. The resulting TEOLED demonstrates a record-high external quantum efficiency (EQE) (maximum: 68.7% and average: 63.4% at spectroradiometer; maximum: 44.8% and average: 42.6% at integrating sphere) with a wider color gamut (118%) owing to the redshift of the spectrum by J-aggregation. Deconvolution of the EL intensities is performed to clarify the contribution of Amp-MSs to the device EQE enhancement (optical scattering by Amp-MSs: 17.0%, PL by radiative energy transfer: 9.1%, and EL by J-aggregated excitons: 4.6%). The proposed TEOLED outperforms the existing frameworks in terms of device efficiency.

Deep Learning-Based Prediction of the 3D Postorthodontic Facial Changes

With the increase of the adult orthodontic population, there is a need for an accurate and evidence-based prediction of the posttreatment face in 3 dimensions (3D). The objectives of this study are 1) to develop a 3D postorthodontic face prediction method based on a deep learning network using the patient-specific factors and orthodontic treatment conditions and 2) to validate the accuracy and clinical usability of the proposed method. Paired sets (n = 268) of pretreatment (T1) and posttreatment (T2) cone-beam computed tomography (CBCT) of adult patients were trained with a conditional generative adversarial network to generate 3D posttreatment facial data based on the patient's gender, age, and the changes of upper (ΔU1) and lower incisor position (ΔL1) as input. The accuracy was calculated with prediction error and mean absolute distances between real T2 (T2) and predicted T2 (PT2) near 6 perioral landmark regions, as well as percentage of prediction error less than 2 mm using test sets (n = 44). For qualitative evaluation, an online survey was conducted with experienced orthodontists as panels (n = 56). Overall, PT2 indicated similar 3D changes to the T2 face, with the most apparent changes simulated in the perioral regions. The mean prediction error was 1.2 ± 1.01 mm with 80.8% accuracy. More than 50% of the experienced orthodontists were unable to distinguish between real and predicted images. In this study, we proposed a valid 3D postorthodontic face prediction method by applying a deep learning algorithm trained with CBCT data sets.

Scalable Three-Dimensional Recording Electrodes for Probing Biological Tissues

Electrophysiological recording technologies can provide critical insight into the function of the nervous system and other biological tissues. Standard silicon-based probes have limitations, including single-sided recording sites and intrinsic instabilities due to the probe stiffness. Here, we demonstrate high-performance neural recording using double-sided three-dimensional (3D) electrodes integrated in an ultraflexible bioinspired open mesh structure, allowing electrodes to sample fully the 3D interconnected tissue of the brain. In vivo electrophysiological recording using 3D electrodes shows statistically significant increases in the number of neurons per electrode, average spike amplitudes, and signal to noise ratios in comparison to standard two-dimensional electrodes, while achieving stable detection of single-neuron activity over months. The capability of these 3D electrodes is further shown for chronic recording from retinal ganglion cells in mice. This approach opens new opportunities for a comprehensive 3D interrogation, stimulation, and understanding of the complex circuitry of the brain and other electrogenic tissues in live animals over extended time periods.

Microstructural Gradational Properties of Sn-Doped Gallium Oxide Heteroepitaxial Layers Grown Using Mist Chemical Vapor Deposition

This study examined the microstructural gradation in Sn-doped, n-type Ga₂O₃ epitaxial layers grown on a two-inch sapphire substrate using horizontal hot-wall mist chemical vapor deposition (mist CVD). The results revealed that, compared to a single Ga₂O₃ layer grown using a conventional single-step growth, the double Ga₂O₃ layers grown using a two-step growth process exhibited excellent thickness uniformity, surface roughness, and crystal quality. In addition, the spatial gradient of carrier concentration in the upper layer of the double layers was significantly affected by the mist flow velocity at the surface, regardless of the dopant concentration distribution of the underlying layer. Furthermore, the electrical properties of the single Ga₂O₃ layer could be attributed to various scattering mechanisms, whereas the carrier mobility of the double Ga₂O₃ layers could be attributed to Coulomb scattering owing to the heavily doped condition. It strongly suggests the two-step-grown, lightly-Sn-doped Ga₂O₃ layer is feasible for high power electronic devices.

Percutaneous coronary intervention in patients with peripheral artery disease and adverse cardiovascular adverse event and bleeding

Background

Peripheral artery disease (PAD) increase the risk of comorbidity and mortality in coronary artery disease (CAD).

Objectives

We evaluate influence of PAD on prognosis in patients undergoing percutaneous coronary intervention (PCI).

Methods

We analyzed all consecutive patients included in our dedicated local registry for PCI between January 2011 and December 2016. Presence of PAD was defined by decreased ankle-brachial index (&lt;0.9). Major adverse cardiovascular event (MACE) was defined as a composite of cardiovascular death, non-fatal myocardial infarct, revascularization, and ischemic stroke. Major bleeding was defined as Bleeding Academic Research Consortium 3 or 5.

Results

Among the 4,747 patients who underwent the PCI, 12.9% (n=610) of PAD were identified. Old age (&gt;60 years), renal dysfunction, reduced ejection fraction, and presence of PAD were predictors with both MACE and major bleeding event. Among them, presence of PAD was an independent risk factor of MACE and major bleeding (MACE, HR 8.26, 95% CI 2.33- 29.41, p=0.036; major bleeding, HR 3.11, 95% CI 1.10–10.63, p=0.040, respectively). The MACE and major bleeding rate at 5-year was significantly increased in patients with PAD (MACE, 30.0% vs. 15.8%, log rank test p&lt;0.001; major bleeding, 6.7 vs. 3.6%, log rank test p=0.003, respectively) (Figure).

Conclusion

Presence of PAD was strongly associated with higher rate of long-term MACE and major bleeding. These findings could have a clinical relevance in requiring individualized pharmacologic strategies to reduce the burden of cardiovascular disease.

Funding Acknowledgement

Type of funding sources: None.

Impact of active and stable cancer on survival in patients undergoing percutaneous coronary intervention

Background

With advances in treatment of ischemic heart disease and cancer treatment, use of percutaneous coronary intervention (PCI) in cancer survivors and patients with active cancer (AC) is expanding.

Objectives

The purpose of this study was to determine the impact of cancer on survival and major cardiovascular events (MACE) in a long-term, single-center cohort of patients treated with PCI.

Methods

Patients treated with PCI between January 2010 and December 2017 were grouped as follows: controls (patients without cancer), stable cancer (SC), and AC. AC was included patients with cancer diagnosed within the past 6 months, patients who had cancer-related therapy within the past 6 months, active metastatic disease, or active recurrence of the cancer. The primary endpoints were 5-year survival and a secondary endpoint was 5-year MACE.

Results

A total of 6,743 patients (age 66±12 years, 68.4% men) treated with PCI were included: 6,404 (95.0%) controls, 245 (3.6%) SC, and 94 (1.4%) AC. Predominant malignancies were gastrointestinal (37.4%), lung (22.7%), and genitourinary cancer (14.7%). No differences were observed between patients with AC, SC and controls regarding 5-year MACE (total MACE, 33.2% vs. 28.1% vs. 17.5%, p=0.072; cardiac death, 13.6% vs. 9.1% vs. 6.7%, p=0.066; non-fatal myocardial infarction, 2.9% vs. 7.5% vs. 7.8%, p=0.820; revascularization, 17.9% vs. 17.6% vs. 11.6%, p=0.794, respectively). Patients with AC and SC had reduced 5-year survival compared with controls (62.0% vs. 81.5% vs. 89.8%, p&lt;0.001) (Figure). AC was associated with a 1.76 (95% CI 1.22 to 2.54, p=0.002) fold increased risk of all-cause 5-year mortality in multivariable adjusted models.

Conclusions

Cumulative incidence of 5-year survival was discriminated by concurrent status of cancer following PCI. Individualized decision making is needed in the routine practice of PCI regarding concurrent cancer-specific treatment and prognosis.

Funding Acknowledgement

Type of funding sources: None.

Pemetrexed plus cisplatin in patients with previously treated advanced sarcoma: a multicenter, single-arm, phase II trial

Background

Patients with advanced sarcomas have a poor prognosis and few treatment options that improve overall survival. We assessed the efficacy and tolerability of pemetrexed and cisplatin combination therapy in patients with refractory bone and soft tissue sarcoma (STS).

Patients and Methods

Patients were included in this multicenter, phase II study (ClinicalTrials.gov identifier NCT03809637) if they progressed after receiving one or more chemotherapy regimens containing an anthracycline and/or ifosfamide. Pemetrexed was first administered intravenously, followed by cisplatin, over a cycle of 21 days, for a maximum of six cycles. The primary endpoint was a progression-free rate (PFR) at 3 months (3-month PFR).

Results

From January 2017 to September 2019, we enrolled 37 patients; of these, 73% had previously undergone three or more rounds of chemotherapy. Five patients (13.5%) exhibited objective responses, including two patients (2/6, 33.3%) with malignant peripheral nerve sheath tumors, one patient (1/4, 25%) with synovial sarcoma, one patient (1/4, 25%) with undifferentiated pleomorphic sarcoma, and one patient (1/4, 25%) with angiosarcoma. The median progression-free survival was 2.6 months, and the 3-month PFR was 45.9% (n = 17). None of the four patients with osteosarcoma exhibited objective responses or were progression free at 3 months. The most frequent treatment-related grade 3-4 toxicities included neutropenia (16.2%), anemia (13.5%), thrombocytopenia (13.5%), and fatigue (8.1%). Among 26 patients (70.3%) available for immunohistochemical assessments, patients in the low-excision repair cross-complementation group 1 (ERCC1) and low-thymidylate synthase expression groups showed a tendency for longer overall survival.

Conclusions

Combination therapy with pemetrexed and cisplatin was associated with clinically meaningful and sustained responses among patients with advanced and refractory STS. The combination therapy met its predefined primary study endpoint.

•

Pemetrexed and cisplatin show promising efficacy for advanced sarcoma treatment, particularly as a salvage therapy option.

•

The combination therapy met its predefined primary endpoint, with a 3-month PFR of 45.9%.

•

Pemetrexed and cisplatin showed acceptable toxicity in heavily treated sarcoma patients.

Pikeienuella piscinae gen. nov., sp. nov., a novel genus in the family Rhodobacteraceae

A novel bacterium, designated strain RR4-56T, was isolated from a biofilter of a seawater recirculating aquaculture system. The 16S rRNA gene sequence analysis showed that the isolate was closely related to Halovulum dunhuangense YYQ-30T (92.6%), Albimonas donghaensis DS2T (91.3%), Pontivivens insulae GYSW-23T (91.3%), and Monaibacterium marinum C7T (90.9%), belonging to the family Rhodobacteraceae. The strain was aerobic, Gram-negative, rod-shaped, oxidase-positive, and catalase-negative. Its optimum temperature, pH, and salinity for growth were 25-30°C, pH 8.5, and 2-3% NaCl (w/v), respectively. Its growth occurred at 15-35°C, pH 5.0-9.5, and 0-7% NaCl (w/v). It contained ubiquinone-10 (Q-10), a respiratory quinone, and the major cellular fatty acids were 11-methyl C18:1 ω7c (31.9%), C18:1 ω6c (30.4%), and C19:0 cyclo ω8c (16.1%). The polar lipids present in the strain were phosphatidylglycerol, an unidentified phospholipid, and an unidentified aminolipid. The strain had one 4,373,045 bp circular chromosome with G + C contents of 65.9 mol% including 4,169 genes, 4,118 coding sequences (CDSs), 3 rRNAs, and 45 tRNAs. Genome annotation predicted some gene clusters related to the degradation of several types of organic matter such as protocatechuate, catechol, and phthalate. Based on the polyphasic characteristics, RR4-56T represents a novel genus and species in the family Rhodobacteraceae, for which the name Pikeienuella piscinae gen. nov., sp. nov. was proposed. The type strain is RR4-56T (= KCTC 52648T = DSM 107918T).

Highly efficient, heat dissipating, stretchable organic light-emitting diodes based on a MoO3/Au/MoO3 electrode with encapsulation

Stretchable organic light-emitting diodes are ubiquitous in the rapidly developing wearable display technology. However, low efficiency and poor mechanical stability inhibit their commercial applications owing to the restrictions generated by strain. Here, we demonstrate the exceptional performance of a transparent (molybdenum-trioxide/gold/molybdenum-trioxide) electrode for buckled, twistable, and geometrically stretchable organic light-emitting diodes under 2-dimensional random area strain with invariant color coordinates. The devices are fabricated on a thin optical-adhesive/elastomer with a small mechanical bending strain and water-proofed by optical-adhesive encapsulation in a sandwiched structure. The heat dissipation mechanism of the thin optical-adhesive substrate, thin elastomer-based devices or silicon dioxide nanoparticles reduces triplet-triplet annihilation, providing consistent performance at high exciton density, compared with thick elastomer and a glass substrate. The performance is enhanced by the nanoparticles in the optical-adhesive for light out-coupling and improved heat dissipation. A high current efficiency of ~82.4 cd/A and an external quantum efficiency of ~22.3% are achieved with minimum efficiency roll-off.

Groundwater contamination assessment in Ulaanbaatar City, Mongolia with combined use of hydrochemical, environmental isotopic, and statistical approaches

Ulaanbaatar City, Mongolia is rapidly becoming urbanized and attracts great attention because of environmental issues. This study was performed to assess the status of groundwater quality in Ulaanbaatar at an early but growing stage of urbanization, focusing on nitrate contamination in relation to land use. Along with high total dissolved solids and NO₃^- concentrations, significant contamination of groundwater is indicated by positive loadings of NO₃^-, Cl^- and δ¹⁵N-NO₃^- along the first principal component of the principal component analysis (PCA). Based on the concentrations and δ¹⁵N values of nitrate, groundwater is classified into two groups: Group I (baseline quality) and II (contaminated). Nitrate in Group II water in urbanized (esp. peri-urban) areas is higher in concentration (> 10 mg/l NO₃^-) and N-isotopic values (> 10‰ δ¹⁵N-NO₃^-), while pristine hydrochemistry is observed restrictedly in grassland and forest areas. Other ions (e.g., Cl^- and SO₄^2-) are also higher in Group II water. The δ¹⁵N-NO₃^- values in Group II water in combination with the spatial distribution on the land use map indicate that nitrate originates from untreated sewage effluents including pit-latrine leakage in peri-urban areas, while nitrate in Group I water originates from soil organic matter. The relationship between nitrate concentrations and δ²H (and δ¹⁸O) values of water suggests that nitrate enrichment is also influenced by evaporation during groundwater recharge. With the help of PCA for compositional data, we suggest a hydrochemical index for groundwater contamination assessment; i.e., the Groundwater Quality Index (GQI) that consists of three variables (concentrations of dissolved silica, nitrate and chloride) and can be used to delineate zones vulnerable to nitrate contamination as a crucial step for the efficient monitoring and management of groundwater quality. The study results suggest an urgent need for the management of unsealed pit latrines that are common in peri-urban areas with high population density.

Vibration reduction during milling of highly flexible workpieces using active workpiece holder system

The milling of highly flexible workpieces, such as thin-walled structures used in turbine blades, aerospace equipment, and jet engine compressors, requires vibration compensation to improve the quality of the workpiece surface. Vibration can be reduced by selecting appropriate cutting parameters. However, this approach reduces system productivity. This paper presents an active workpiece holder that controls the vibration of general computer numerical control machine tools. The proposed holder, which comprises a flexible guide mechanism, driver, and sensor, measures vibration and actively controls it using piezoactuators. A high-rigidity flexure mechanism was designed for the holder, and finite element method simulation and modal analysis were performed. Finally, the proposed system was fabricated, and experimental verification indicated that the system reduced vibration. The surface quality obtained using the controlled system was ∼50% better than that obtained using the uncontrolled system.

Toward Large-Scale Ga2O3 Membranes via Quasi-Van Der Waals Epitaxy on Epitaxial Graphene Layers

Epitaxial growth using graphene (GR), weakly bonded by van der Waals force, is a subject of interest for fabricating technologically important semiconductor membranes. Such membranes can potentially offer effective cooling and dimensional scale-down for high voltage power devices and deep ultraviolet optoelectronics at a fraction of the bulk-device cost. Here, we report on a large-area β-Ga₂O₃ nanomembrane spontaneous-exfoliation (1 cm × 1 cm) from layers of compressive-strained epitaxial graphene (EG) grown on SiC, and demonstrated high-responsivity flexible solar-blind photodetectors. The EG was favorably influenced by lattice arrangement of SiC, and thus enabled β-Ga₂O₃ direct-epitaxy on the EG. The β-Ga₂O₃ layer was spontaneously exfoliated at the interface of GR owing to its low interfacial toughness by controlling the energy release rate through electroplated Ni layers. The use of GR templates contributes to the seamless exfoliation of the nanomembranes, and the technique is relevant to eventual nanomembrane-based integrated device technology.

Purcell-enhanced photoluminescence of few-layer MoS2 transferred on gold nanostructure arrays with plasmonic resonance at the conduction band edge

Plasmonic coupling of metallic nanostructures with two-dimensional molybdenum disulfide (MoS2) atomic layers is an important topic because it provides a pathway to manipulate the optoelectronic properties and to overcome the limited optical cross-section of the materials. Plasmonic enhanced light-matter interaction of a MoS2 layer is known to be mainly governed by optical field enhancement and the Purcell effect, while the discrimination of the contribution from each mechanism to the plasmonic enhancement is challenging. Here, we investigate photoluminescence (PL) enhancement from few-layer MoS2 transferred on Au nanostructure arrays with controlled localized surface plasmon resonance (LSPR) spectral positions that were detuned from the excitation wavelengths. Two distinctive regimes in LSPR mode-dependent PL enhancement were revealed showing a maximum enhancement (∼40-fold) with zero detuning and a modest enhancement (∼10-fold) with the red-shift detuned LSPR from the excitation wavelength, which were attributed to LSPR-induced optical field enhancement and the Purcell effect, respectively. By applying the experimental parameters into the Purcell effect formalism, an effective mode volume of ∼0.016λ03 was estimated. Our work provides an insight into how to utilize few-layer MoS2 as a base material for optoelectronics by harnessing Purcell-enhanced optical responsivity.

Fabrication of plasmonic arrays of nanodisks and nanotriangles by nanotip indentation lithography and their optical properties

Fabrication of plasmonic nanostructures in a precise and reliable manner is a topic of huge interest because their structural details significantly affect their plasmonic properties. Herein, we present nanotip indentation lithography (NTIL) based on atomic force microscopy (AFM) indentation for the patterning of plasmonic nanostructures with precisely controlled size and shape. The size of the nanostructures is controlled by varying the indentation force of AFM tips into the mask polymer; while their shapes are determined to be nanodisks (NDs) or nanotriangles (NTs) depending on the shapes of the AFM tip apex. The localized surface plasmon resonance of the NDs is tailored to cover most of the visible-wavelength regime by controlling their size. The NTs show distinct polarization-dependent plasmon modes consistent with full-wave optical simulations. For the demonstration of the light-matter interaction control capability of NTIL nanostructures, we show that photoluminescence enhancement from MoS2 layers can be deliberately controlled by tuning the size of the nanostructures. Our results pave the way for the AFM-indentation-based fabrication of plasmonic nanostructures with a highly precise size and shape controllability and reproducibility.

Characteristics of silicon nitride deposited by very high frequency (162 MHz)-plasma enhanced atomic layer deposition using bis(diethylamino)silane

Silicon nitrides, deposited by capacitively coupled plasma (CCP)-type plasma enhanced atomic layer deposition (PEALD), are generally applied to today's nanoscale semiconductor devices, and are currently being investigated in terms of their potential applications in the context of flexible displays, etc. During the PEALD process, 13.56 MHz rf power is generally employed for the generation of reactive gas plasma. In this study, the effects of a higher plasma generation frequency of 162 MHz on both plasma and silicon nitride film characteristics are investigated for the purpose of silicon nitride PEALD, using bis(diethylamino)silane (BDEAS) as the silicon precursor, and N₂ plasma as the reactant gas. The PEALD silicon nitride film deposited using the 162 MHz CCP exhibited improved film characteristics, such as reduced surface roughness, a lower carbon percentage, a higher N/Si ratio, a lower wet etch rate in a diluted HF solution, lower leakage current, and higher electric breakdown field, and more uniform step coverage of the silicon nitride film deposited in a high aspect ratio trench, as compared to silicon nitride PEALD using 13.56 MHz CCP. These improved PEALD silicon nitride film characteristics are believed to be related to the higher ion density, higher reactive gas dissociation, and lower ion bombardment energy to the substrate observed in N₂ plasma with a 162 MHz CCP.

Polarization Control of Deterministic Single-Photon Emitters in Monolayer WSe2

Single-photon emitters, the basic building blocks of quantum communication and information, have been developed using atomically thin transition metal dichalcogenides (TMDCs). Although the bandgap of TMDCs was spatially engineered in artificially created defects for single-photon emitters, it remains a challenge to precisely align the emitter's dipole moment to optical cavities for the Purcell enhancement. Here, we demonstrate position- and polarization-controlled single-photon emitters in monolayer WSe₂. A tensile strain of ∼0.2% was applied to monolayer WSe₂ by placing it onto a dielectric rod structure with a nanosized gap. Excitons were localized in the nanogap sites, resulting in the generation of linearly polarized single-photon emission with a g⁽²⁾ of ∼0.1 at 4 K. Additionally, we measured the abrupt change in polarization of single photons with respect to the nanogap size. Our robust spatial and polarization control of emission provides an efficient way to demonstrate deterministic and scalable single-photon sources by integrating with nanocavities.

Delineating the impacts of poultry burial leachate on shallow groundwater in a reclaimed agro-livestock farming area, using multivariate statistical analysis of hydrochemical data

Burial is applied to dispose of livestock carcasses due to its convenience and cost efficiency despite concerns about groundwater contamination by leachate from burial pits. In particular, the burial method has caused debates about groundwater contamination sources around on-farm livestock burial sites because of pre- and coexisting contamination from livestock production and agriculture. To assess the causes of groundwater contamination around poultry burial pits that were constructed after an outbreak of avian influenza in 2010-11 in Korea, hydrochemical data of groundwater samples from monitoring wells (MWs, n = 14) and household wells (HWs, n = 30) were monitored to differentiate contamination sources. Hydrochemical data indicated that groundwater from MWs is characterized by higher enrichments of inorganic constituents including electrical conductivity (EC), NH₄, Ca, Mg, K, SO₄, HCO₃, Fe_(Total), and Mn_(Total), but lower concentrations of DO than groundwater from HWs. The combined use of the principal component analysis (PCA) and K-means cluster analysis (KCA) indicated that groundwater in seven MWs was affected by leachate. The parameters such as NH₄, Ca, Mg, K, SO₄, HCO₃, Fe_(Total), and Mn_(Total) are expected to be useful to identify the impact of leachate on groundwater in agricultural areas. This study suggests that (1) regional hydrochemical characteristics should be assessed to distinguish the effect of livestock burial leachate from other contamination sources and (2) the combined use of PCA and KCA is effective to identify the weakened impact of leachate leakage among overlapping multiple sources and processes of groundwater contamination.

Recent advances in nanocavities and their applications

High quality factor and small mode volume in nanocavities enable the demonstration of efficient nanophotonic devices with low power consumption, strong nonlinearity, and high modulation speed, due to the strong light-matter interaction. In this review, we focus on recent state-of-the-art nanocavities and their applications. We introduce single nanocavities including semiconductor nanowires, plasmonic cavities, and nanostructures based on quasi-bound states in the continuum (quasi-BIC), for laser, photovoltaic, and nonlinear applications. In addition, nanocavity arrays with unique feedback mechanisms, including BIC cavities, parity-time symmetry coupled cavities, and photonic topological cavities, are introduced for laser applications. These various cavity designs and underlying physics in single and array nanocavities are useful for the practical implementation of promising nanophotonic devices.

Mie-Resonant Three-Dimensional Metacrystals

Optical metamaterials, engineered to exhibit electromagnetic properties not found in natural materials, may enable new light-based applications including cloaking and optical computing. While there have been significant advances in the fabrication of two-dimensional metasurfaces, planar structures create nontrivial angular and polarization sensitivities, making omnidirectional operation impossible. Although three-dimensional (3D) metamaterials have been proposed, their fabrication remains challenging. Here, we use colloidal crystal engineering with DNA to prepare isotropic 3D metacrystals from Au nanocubes. We show that such structures can exhibit refractive indices as large as ∼8 in the mid-infrared, far greater than that of common high-index dielectrics. Additionally, we report the first observation of multipolar Mie resonances in metacrystals with well-formed habits, occurring in the mid-infrared for submicrometer metacrystals, which we measured using synchrotron infrared microspectroscopy. Finally, we predict that arrays of metacrystals could exhibit negative refraction. The results present a promising platform for engineering devices with unnatural optical properties.

Pukyongiella litopenaei gen. nov., sp. nov., a novel bacterium isolated from the gut content of a whiteleg shrimp Litopenaeus vannamei

A Gram-negative, aerobic bacterium, designated as SH-1^T, was isolated from the gut content of a whiteleg shrimp, Litopenaeus vannamei collected in a shrimp farm in South Korea. The bacterial cells were ovoid rod-shaped, non-motile, oxidase-positive and catalase-negative. Growth was observed at 20-35 °C (optimum, 30 °C), pH 5.0-9.5 (pH 8.5) and in the presence of 0-6 % (w/v) NaCl (2-3 %). The major polar lipids were phosphatidylglycerol, phosphatidylinositolmannoside, unidentified aminolipid and two unidentified lipids. The G+C content was 66.1 mol% and the predominant respiratory quinone was Q-10. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain SH-1^T was placed in a distinct clade with Primorskyibacter marinus PX7^T (96.97 % sequence similarity), Pontibaca methylaminivorans DSM 21219^T (96.03 %) and Pelagivirga sediminicola BH-SD19^T (95.02 %) in the family Rhodobacteraceae and distantly related with them to be a new genus. The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) values calculated from whole-genome-sequence comparison between the SH-1^T and the close species were in the ranges of 19.0-19.8, 73.8-74.9 and 64.1-65.9 %, respectively. Based on the polyphasic analysis presented in this study, we suggest that strain SH-1^T represents a novel genus and species in the family Rhodobacteraceae, for which the name Pukyongiella litopenaei gen. nov., sp. nov. is proposed. The type strain of Pukyongiella litopenaei is SH-1^T (=KCTC 62276^T=MCCC 1K04072^T).

The Association with rhegmatogenous retinal detachment and paediatric atopic dermatitis: a 12-year Nationwide Cohort Study

PURPOSE

Historically, atopic dermatitis (AD) is associated with an increased risk of rhegmatogenous retinal detachment (RRD). However, uncertainty remained regarding the effect of AD itself and comorbidities (e.g., allergic diseases, cataract surgery) on RRD occurrence in a large, population-based paediatric population.

PATIENTS AND METHODS

We analysed the 12-year National Health Insurance Service database (2002-2013) covering the entire Korean population to estimate the association between AD and RRD in people aged under 20 years.

RESULTS

We identified 3142 RRD patients, and matched 18,852 controls (six controls to each RRD patient); therefore, we included 21,994 peoples under aged 20 years in the analyses. AD was more prevalent in the RRD group (329 patients, 10.47%) than the control group (1043 patients, 5.53%; P < 0.001), and so were severe AD (153 patients [4.87%] and 223 patients [1.18%], respectively; P < 0.001). In conditional logistic regression analysis, AD was associated with RRD (OR, 1.61; 95% CI, 1.93-1.87) even after adjusting for allergic conditions, connective tissue disease, uveitis, and cataract surgery. In addition, severity of AD was associated with an increased risk of RRD (OR for non-severe AD and severe AD, 1.26 [95% CI, 1.05-1.51] and 2.88 [95% CI, 2.25-3.68]).

CONCLUSION

This study suggests that AD itself is a risk factor of RRD in children by showing the association between AD and RRD occurrence and the biologic gradient even after adjustment for known confounders including allergic conditions, uveitis, and cataract surgery.

Development and control of a hybrid active mount module for precision stages

In recent years, precision stages, which are widely used in many industrial fields, have been required to have a higher speed, larger size, and higher precision to help realize higher productivity and product quality. High-performance positioning techniques for inspection and production equipment are classified as one of the most challenging technologies. Vibration control is crucial to realize high-precision positioning technologies. In a precision system, various vibrations exist, which act as disturbances and can degrade the system performance. Minimizing the vibrations generated by the system can, thus, help improve the accuracy of system positioning. This paper proposes a hybrid active mount module for a precision stage. The developed module improves stage performance by reducing the base vibration arising from the floor, minimizing the vibration caused by the driving linear motors of the precision stage, and reducing the settling time by compensating the offset displacement due to the nonlinearity of the passive mount during stage driving. The prototype design is presented herein, and the experimental results demonstrate the potential of the developed device. The developed system is expected to effectively improve the stage performance by controlling the various causes of vibration.

Structured silicon for revealing transient and integrated signal transductions in microbial systems

Bacterial response to transient physical stress is critical to their homeostasis and survival in the dynamic natural environment. Because of the lack of biophysical tools capable of delivering precise and localized physical perturbations to a bacterial community, the underlying mechanism of microbial signal transduction has remained unexplored. Here, we developed multiscale and structured silicon (Si) materials as nongenetic optical transducers capable of modulating the activities of both single bacterial cells and biofilms at high spatiotemporal resolution. Upon optical stimulation, we capture a previously unidentified form of rapid, photothermal gradient-dependent, intercellular calcium signaling within the biofilm. We also found an unexpected coupling between calcium dynamics and biofilm mechanics, which could be of importance for biofilm resistance. Our results suggest that functional integration of Si materials and bacteria, and associated control of signal transduction, may lead to hybrid living matter toward future synthetic biology and adaptable materials.

Survival of medial versus lateral unicompartmental knee arthroplasty: A meta-analysis

Many studies have found associations between unicompartmental knee arthroplasty (UKA) and implant survival, but controversy still exists regarding the relative survival of medial versus lateral UKA over mid-to long-term follow-up. The purpose of this study was to compare survival and clinical outcomes of medial and lateral UKAs. In this meta-analysis, we reviewed studies that assessed implant survival in patients who underwent medial or lateral UKA with short- to mid-term (<10years) or long-term (>10years) follow-up, and that used assessments, such as pain and function scores, to compare postoperative scores on knee outcome scales. A total of eight studies (33,999 knees with medial UKA and 2,853 with lateral UKA) met the inclusion criteria and was analyzed in detail. There were no significant differences between medial and lateral UKA in pain score (95% CI: -0.37 to 0.88; P = 0.42), function score (95% CI: -0.19 to 0.60; P = 0.31), short- to mid-term survival (medial, 32,083/33,483; lateral, 2,636/2,726; OR 0.98, 95% CI: 0.64 to 1.48;P = 0.91), or long-term survival (medial, 479/516; lateral, 110/127; OR 2.51, 95% CI:0.67 to 9.43; P = 0.17). In addition, both groups had substantial proportions of knees with short- to mid-term survival (95.6% by medial UKA and 94.6% by lateral UKA) and long-term survival (92.8% by medial UKA and 86.6% by lateral UKA). This meta-analysis found no significant differences in short- to mid-term and long-term survival of medial and lateral UKAs. Similarly, patients treated with medial UKA showed no difference in pain relief or functional improvement compared to patients treated with lateral UKA. These results suggest that both UKA techniques are viable treatment options for patients with unicompartmental knee osteoarthritis over long-term follow-up, although further high-quality studies are needed to address some remaining uncertainties regarding the clinical benefits of these procedures.

Ultrafast Transient Spectroscopy of Trans-Polyacetylene in the Midinfrared Spectral Range

Trans-polyacetylene [t-(CH)_{x}] possesses twofold ground state degeneracy. Using the Su-Schrieffer-Heeger Hamiltonian, scientists predicted charged solitons to be the primary photoexcitations in t-(CH)_{x}; this prediction, however, has led to sharp debate. To resolve this saga, we use subpicosecond transient photomodulation spectroscopy in the mid-IR spectral range (0.1-1.5 eV) in neat t-(CH)_{x} thin films. We show that odd-parity singlet excitons are the primary photoexcitations in t-(CH)_{x}, similar to many other nondegenerate π-conjugated polymers. The exciton transitions are characterized by two photoinduced absorption (PA) bands at 0.38 and 0.6 eV, and an associated photoluminescence band at ∼1.5  eV having similar polarization memory. The primary excitons undergo internal conversion within ∼100  fs to an even-parity (dark) singlet exciton with a PA band at ∼1.4  eV. We also find ultrafast photogeneration of charge polarons when pumping deep into the polymer continuum band, which are characterized by two other PA bands in the mid-IR and associated photoinduced IR vibrational modes.

P1443 Sex differences of coronary physiology can be justified by fractional myocardial mass

Purpose

We hypothesized that the gender difference in the anatomical-physiological relationship may elucidate the gender difference in the clinical presentation of coronary artery disease.

Background Women has lower prevalence of coronary artery disease but has higher mortality from acute myocardial infarction. The gender difference in the anatomical-physiological relationship may elucidate the gender difference in the clinical presentation of coronary artery disease.

Methods In this multicenter registry, 482 patients who underwent coronary CT angiography and fractional flow reserve (FFR) measurement were enrolled. Fractional myocardial mass (FMM, a vessel-specific amount of myocardium) and %FMM (fraction of FMM to whole myocardial mass) was measured in major coronary arteries and branches. FFR and quantitative coronary angiography (QCA) were interrogated in the subset of 772 vessels. The severity of physiological or anatomical stenosis was assessed by FFR and diameter stenosis (DS), respectively.

Results In the analysis of all major epicardial arteries (N = 3,833), FMM was lower in women compared to men (p &lt; 0.01, all), but %FMM was similar between women and men (p = NS, all). Among physiologically assessed 772 vessels, compared to men (N = 587), vessels of women (N = 185) showed smaller dimension (reference diameter (RD) = 2.90 ± 0.65 vs 3.14 ± 0.69 mm, minimal luminal diameter (MLD) = 1.30±.0.57 vs 1.40 ± 0.57 mm (p &lt; 0.05, all), similar severity of stenosis (DS = 55% vs 55% p = NS), and higher FFR (0.81 ± 0.13 vs 0.78 ± 0.15, p &lt; 0.001). In subgroup analysis according to the tertiary categories of DS, RD, and MLD, vessels of women showed higher FFR and lower FMM. Generalized estimating equations modeling demonstrated that gender, DS, RD, MLD, and location in left anterior descending artery were not (p = NS, all) but FMM/MLD were significant predictors for FFR ≤ 0.80 (p = 0.021).

Conclusions

Compared to men, coronary arteries of women are smaller and supply smaller amount of myocardium even after adjusting for vessel size, which may explain overall higher FFR value of women. This gender difference in anatomical-physiological relationship may explain the gender difference in the clinical coronary artery disease.

Abstract P1443 Figure.

1175 Comparison of fractional myocardial mass, a vessel-specific myocardial mass-at-risk, with coronary angiographic scoring systems for predicting myocardial ischemia

Aims The burden of coronary artery disease has been assessed by various semi-quantitative angiographic scores, which are frequently different each other. A non-invasive and quantitative modality may substitute angiographic sores for prognostic implication and decision of revascularization strategy. We compared fractional myocardial mass (FMM) with angiographic scores for predicting myocardial ischemia.

Methods In this multicenter registry, 411 patients who underwent coronary computed tomography angiography (CCTA) were followed by invasive coronary angiography and FFR measurement. CCTA–derived %FMM with diameter stenosis ≥70% (%FMM-70) or ≥50% (%FMM-50) were compared with 9 angiographic scores (APPROACH, Duke Jeopardy, BARI, CASS, SYNTAX, Jenkins, BCIS-1, Leaman, Modified Duke) and were tested regarding their performance for predicting FFR ≤ 0.80. Predictive performance of %FMM or angiographic scores for FFR ≤ 0.80 established in derivation cohort (N = 250) and tested in validation cohort (N = 161).

Results The performance of %FMM-70 and %FMM-50 were similar to most angiographic scores (%FMM-70, c-statistics = 0.76; %FMM-50, 0.71; angiographic scores, 0.68 – 0.79). The frequency of FFR ≤ 0.80 increased consistently according to %FMM-70, %FMM-50, and all angiographic scores (p &lt; 0.001, all). The optimal cutoff of %FMM-50 and %FMM-70 for FFR ≤ 0.80 were ≥34.5% and ≥9.8%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of %FMM-50 were 83%, 56%, 73%, 70%, 72%, and of %FMM-70 were 72%, 78%, 75%, 75%, and 75% using these cutoffs. Validation cohort showed consistent results.

Conclusion %FMM correlated well with angiographic scores and had a potential to be used as a non-invasive alternative to the angiographic scores. The integration of the severity of stenosis and the amount of subtended myocardium may improve the detection of clinically significant coronary artery stenosis.

Abstract 1175 Figure. FMM vs angiographic score

P1368 Effect of angiotensin receptor blocker in patients with moderate or severe aortic stenosis: a randomized controlled trial

Funding Acknowledgements

This study was supported by grants from Boryung Pharmacy Research Fund.

Background/Introduction: Pathophysiology of aortic stenosis (AS) and several previous studies suggested the potential role of angiotensin receptor blocker (ARB) in patients with AS.

Purpose

We aimed to investigate the effects of Fimasartan, an ARB, on exercise capacity and progression of AS in patients with moderate to severe AS.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled trial in 32 normotensive or controlled-hypertensive patients with moderate or severe AS. Study participants were randomized to Fimasartan 30 mg to 60 mg daily (n = 14) or placebo (n = 18) for 1 year, and underwent cardiopulmonary exercise test, 6-minute walk test, and echocardiography at 0, 6, and 12 months, with follow-up data available in 29 subjects.

Results

Significant reductions in blood pressures were observed in the Fimasartan group but not in the placebo group. Two of the 14 patients in the Fimasartan group withdrew the study due to mild symptoms probably related with the decreased blood pressure, and one patient decline the study protocol. After the 12-month treatment, the peak oxygen consumption (VO2; the primary outcome) in the Fimasartan group was significantly decreased (from 28.3 ± 5.9 to 25.4 ± 3.8 mL/min/kg, P = 0.021) but not in the placebo group (P for interaction = 0.046) (Figure 1A). The severity of AS showed a gradual progression in both groups, without inter-group differences (mean transaortic pressure; Fimasartan group, +4.0 ± 3.8 mmHg/year; placebo group, +5.3 ± 6.2 mmHg/year; P for interaction = 0.429) (Figure 1B). Parameters of left ventricular systolic and diastolic function did not change in both groups.

Conclusions

The use of ARB impaired exercise capacity in patients with moderate or severe AS, and did not prevent the progression of AS. However, due to the small number of participants, further studies are required to confirm these findings.

Abstract P1368 Figure.

P1526Pre-dialysis left atrial function assessed by two-dimensional speckle tracking echocardiography as a predictor of upcoming heart failure in hemodialysis patients

Background

Left atrial global longitudinal strain (LA GLS) by 2-dimensional speckle tracking echocardiography is a useful tool to assess LA function and left ventricular (LV) diastolic function. The authors assessed prognostic value of LA GLS, and other diastolic functional parameters in patients undergoing hemodialysis.

Methods

A total of 78 (49 male) patients undergoing hemodialysis who checked echocardiography due to heart failure (HF) symptoms were included for this analysis. Echocardiography wasperformed at the same day of, and before hemodialysis session. Besides conventional echocardiographic measurements, GLS of the LA and the LV were checked and compared. Incidence of rehospitalization due to HF symptoms during mean follow up duration of 381.4±197.5 days was investigated and echocardiographic parameters were compared between patients who experienced rehospitalization and who did not.

Results

16 (20.1%) patients experienced rehospitalization due to HF. HF rehospitalization group had significantly low baseline LV ejection fraction (55.7±7.2 vs. 61.3±7.1%, p=0.006) and LV GLS (14.7±3.4 vs. 18.2±3.9%, p=0.002), while LV geometry (LV end-diastolic volume index and LV wall thickness) did not show significant differences. In HF rehospitalization group, baseline LA function and diastolic function were significantly impaired as reflected by LA GLS (18.8±2.6 vs. 23.8±3.6%, p<0.001), E/E' ratio (20.8±3.3 vs. 15.8±4.6%, p<0.001), and right ventricular systolic pressure (61.4±9.6 vs. 53.4±12.8%, p=0.022). LA end-systolic volume index was not significantly different between the 2 groups. Among various echocardiographic parameters, receiver operation characteristic curve analysis revealed that LA GLS had the strongest power (cutoff value 20.6%, sensitivity 0.813 and specificity 0.790, area under curve 0.849) in prediction of future rehospitalization due to HF.

Predictor of future HF: ROC analysis

Conclusions

The present study demonstrated that functional changes of the LA as measured by LA GLS before hemodialysis session can be used as an echocardiographic parameter to predict future rehospitalization due to HF. Further studies are required to evaluate prognostic value of LA function in predicting other cardiovascular events in hemodialysis patients.

P3520Admission hyperglycemia is a predictor of mortality of acute heart failure: comparison between patients with and without diabetes mellitus

Background

Regardless of diabetes mellitus (DM), admission hyperglycemia is not uncommon in patients with acute heart failure (AHF). Although DM is a well-known predictor of mortality in AHF, the impacts of admission hyperglycemia on clinical outcomes in non-DM patients with AHF have been poorly studied. The aim of this study, therefore, was to compare the impact of admission hyperglycemia on long-term clinical outcomes in AHF patients with or without DM.

Methods

Among 5,625 AHF patients enrolled in a nationwide registry, a total of 5,541 patients were enrolled and divided into 2 groups; DM group (n=2,125, 70.4±11.4 years) vs. non-DM group (n=3,416, 67.3±16.0 years). Each group were further divided into 2 groups according to the presence of admission hyperglycemia (admission serum glucose level >200mg/dl); admission hyperglycemia (n=248) and no hyperglycemia (n=3,168) in non-DM; admission hyperglycemia (n=799) and no hyperglycemia (n=1,326) in DM. All-cause death and hospitalization due to HF (HHF) during 1-year follow-up were compared.

Results

Death was developed in 1,220 patients (22.2%) including 269 inhospital deaths (4.9%) during 1-year of follow-up. Death rate were significantly higher in DM than in non-DM group (24.8% vs 20.5%, p<0.001), however there was no difference in inhospital death (5.1% vs 4.7%, p=0.534). Both inhospital death (7.6% vs. 4.2%, p<0.001) and 1-year death (26.2% vs. 21.3%, p=0.001) were more frequent in AHF patients with hyperglycemia. On Kaplan-Meier survival curve analysis, however, admission hyperglycemia was associated with significantly higher death (p<0.001 by log-rank test) and rehospitalization (p=0.006 by log-rank test) in non-DM group, but not in DM group. In non-DM group, admission hyperglycemia was an independent predictor of 1-year mortality (HR 1.46, 95% CI 1.10–1.93, p=0.009).

Conclusion

DM was a significant predictor of long-term mortality in patients with AHF. Admission hyperglycemia was associated with both higher inhospital and 1-year mortality. The present study also demonstrated that admission hyperglycemia is an independent predictor of mortality in non-DM patients with AHF, but not in DM patients. In addition to the presence of DM, admission hyperglycemia would be a useful marker in the risk stratification of AHF, especially in non-DM patients.

P688Cardiac dysfunction as a predictor of hepatic sinusoidal obstruction syndrome after hematopoietic cell transplantation

Background

Hepatic sinusoidal obstruction syndrome (HSOS) is a well-known fatal complication of hematopoietic cell transplantation (HCT), but the impact of cardiac abnormalities on the occurrence of HSOS has been poorly evaluated. Therefore, the authors investigated whether the structural changes or dysfunction of the heart before HCT is associated with the future occurrence of HSOS.

Methods

A total of 92 patients who underwent HCT were divided into 2 groups; HSOS group (n=11, 6 males, 53.8±15.9 years) vs no HSOS group (n=81, 51 males, 48.6±14.7 years). According to the modified Seattle criteria, HSOS was defined as otherwise unexplained occurrence of 2 or more of the following events within 20 days of HCT; serum total bilirubin >2 mg/dL, hepatomegaly or right upper quadrant pain, sudden weight gain due to fluid accumulation (>2% of baseline body weight). Echocardiography examinations were performed 1 month before HCT, and echocardiographic findings were compared between the groups.

Results

HSOS was developed in 11 patients (12.0%). HSOS group had significantly larger left ventricular end-diastolic volume index (LVEDVI) (65.2±4.9 vs 53.2±6.9 ml/m2, p<0.001) and relatively worse systolic function than no HSOS group (LV ejection fraction: 56.4±3.4 vs 65.1±5.9%, p<0.001, LV global longitudinal strain: −17.9±1.4 vs −20.1±2.0%, p=0.001). LV diastolic functional parameters were also significantly worse in HSOS group than in no HSOS group (E/E' ratio: 11.3±1.8 vs 9.1±2.0, p=0.002, left atrial global longitudinal strain: 27.7±3.3 vs 34.9±5.9%, p<0.001). However, left atrial volume index was not different between the groups (30.8±2.8 vs 29.0±3.3 ml/m2, p=0.078). By receiver operation characteristic curve analysis, among significantly different variables, LVEDVI was the most powerful predictor for HSOS, and the optimal cutoff value was 59.25 mL/m2. (81.8% sensitivity and 77.8% specificity, AUC 0.909).

Predictor of HSOS: ROC analysis

Conclusions

The present study demonstrated that structural changes or dysfunction of the heart are more prevalent in patients with HSOS after HCT and larger LVEDVI, among them, can be a useful predictor of upcoming HSOS. Routine echocardiographic study before HCT would be useful to identify high risk group for HSOS, and the development of HSOS should be carefully monitored in HCT patients with cardiac structural changes or dysfunction on echocardiography.

P671Impacts of echocardiography-defined pulmonary hypertension on clinical outcome in patients with multiple myeloma

Background

Pulmonary hypertension (PH) is a rarely reported complication of multiple myeloma (MM). PH of MM is usually mild to moderate and can be secondary to a variety of conditions, including left ventricular dysfunction, diastolic dysfunction, chronic heart failure, treatment-related toxicity, thrombophilic condition and precapillary involvement. However, only few reports regarding PH in MM incidence and prognosis exist up to now.

Purpose

The purpose of this study was to investigate the risk factors of transthoracic echocardiography-defined PH and its impact on clinical outcome in patients with MM.

Methods

A total of 277 MM patients was included and divided into 2 groups–those non-pulmonary hypertension (PH) or those with PH, based on the results of the transthoracic echocardiography (TTE); PH group (n=143, 60.9±9.2 years, 68 males) versus non-PH group (n=134, 55.9±11.5 years, 72 males). We analyzed propensity score matching and multiple imputation method were used to deal with the missing data in echocardiographic characteristics.

Results

During the follow-up period (median 618 days), all-cause death occurred in 79 (28.5%) patients and 41 patients (14.8%) died from cardiovascular causes (including acute decompensated heart failure, fatal MI, sudden cardiac arrest). In the Kaplan-Meier survival analysis of crude population and propensity-matched population, cumulative overall survival and cardiovascular death (CVD)-free survival were significantly lower in the PH group than in the non-PH group (p<0.001). In propensity-matched population, estimated pulmonary artery pressure >35mmHg in TTE, congestive heart failure, and DM were significant independent predictors of all-cause death.

KM curves in MM stratified by PH

Conclusion

This study demonstrates that the presence of PH, congestive heart failure, and DM is an independent prognostic factor for all-cause death in MM patients with MM. These results highlight the risk associated cardiovascular disease in MM patients and emphasize that management strategies that prevent deterioration of cardiac function are essential.

Salaquimonas pukyongi gen. nov., sp. nov., a novel bacterium within the family Phyllobacteriaceae

A novel aerobic, Gram-negative bacterial strain, RR3-28^T, was isolated from a seawater recirculating aquaculture system in Busan, Republic of Korea. Cells were rod-shaped, non-motile, oxidase-positive, catalase-negative and grew optimally at 25-30 °C, pH 8.5 and 3 % (w/v) NaCl. Based on the results of phylogenetic analysis, strain RR3-28^T was most closely related to Zhengella mangrovi X9-2-2^T within the family Phyllobacteriaceae with 95.97 % 16S rRNA gene sequence similarity. The major cellular fatty acids were summed feature 8 (C_18 : 1ω7c and/or C_18 : 1ω6c, 71.1 %) and 11-methyl C_18 : 1ω7c (14.4 %). The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine and unidentified aminolipids. The predominant quinone was ubiquinone Q-10 and the DNA G+C content was 58.6 mol%. On the basis of its phenotypic and genotypic characteristics, strain RR3-28^T represents a novel genus and species belonging to the family Phyllobacteriaceae, for which the name Salaquimonas pukyongi gen. nov., sp. nov. is proposed. The type strain of the species is RR3-28^T (=KCTC 52649^T=DSM 107947^T).

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BACKGROUND

Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.

PATIENTS AND METHODS

We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.

RESULTS

A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate.

CONCLUSION

HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.