In Situ Photo-Crosslinkable Protein Bioadhesive for Bone Graft Fixation

Bone grafting is a fundamental dental surgery procedure widely used for implant placement and periodontal disease management treatments. Despite its broad applications, vertical bone augmentation presents unique challenges, including the risk of graft displacement due to gravitational and masticatory forces. Traditional physical stabilization methods introduce additional complexities and risks, underscoring the need for innovative fixation technologies. This study aimed to develop an in situ photo-crosslinkable bioadhesive hydrogel (iPBAH) as a multifunctional bone graft binder to enhance the process of bone reconstruction. The bioadhesive is composed of mussel-derived adhesive protein (MAP) fused with the cell-adhesive peptide RGD. The numerous tyrosine residues in MAP facilitate rapid photo-crosslinking, enabling efficient hydrogel formation using visible blue light. Subsequently, iPBAH underwent comprehensive characterization to evaluate its suitability as a multifunctional bone graft binder. iPBAH efficiently underwent in situ crosslinking through harmless exposure to visible light within minutes and displayed several exceptional properties, including a microporous structure, underwater adhesion, extended durability, high compressive strength, and biocompatibility. In vivo assessments, using male Sprague-Dawley rats, demonstrated that iPBAH binder significantly enhanced bone regeneration in a rat calvarial bone defect model. The in situ crosslinking of the iPBAH binder during bone graft transplantation can effectively fill irregular and complex defect shapes while simultaneously preventing graft material leakage. The improved physical attributes of the bound graft material can enhance its resistance to external forces, thereby ensuring sustained retention over time. Moreover, the interaction between iPBAH and surrounding tissues promotes adhesion and integration of the graft material with host tissues in the defect area. In addition, the included RGD peptide in iPBAH can augment inherent cell recruitment, adhesion, and growth, consequently expediting osteogenesis.

Self-controllable proteinic antibacterial coating with bacteria-triggered antibiotic release for prevention of periprosthetic infection

Periprosthetic infection is a devastating postimplantation complication in which a biofilm layer harboring invasive microorganisms forms around orthopedic implants, leading to severe implant failure and patient morbidity. Despite the development of several infection-triggered antibiotic release approaches, most current antibacterial coatings are susceptible to undesired antibiotic leakage or mechanical disintegration during prosthesis installation. Herein, we propose a self-controllable proteinic antibacterial coating capable of both long-lasting adherence onto titanium implant substrates over the implant fixation period and instantaneous bacterial eradication. Importantly, the pH-dependent reversible metal coordination of mussel adhesive protein (MAP) enabled bacterial concentration-dependent antibiotic delivery in response to infection-induced acidification. In addition, the MAP coating exhibited superior self-healable adhesive properties and scratch resistance, which enabled to avert issues associated with mechanical damages, including peeling and cracking, often occurring in conventional implant coating systems. The gentamicin-loaded MAP coating exhibited complete inhibition of bacterial growth in vivo against Staphylococcus aureus penetrations during implantation surgery (immediate infection) and even 4 weeks after implantation (delayed infection). Thus, our antibiotic-loaded MAP hydrogel coating can open new avenues for self-defensive antibiotic prophylaxis to achieve instant and sustainable bacteriocidal activity in orthopedic prostheses. © 2017 Elsevier Inc. All rights reserved.

Immature bovine cartilage wear is due to fatigue failure from repetitive compressive forces and not reciprocating frictional forces

OBJECTIVE

Wear of articular cartilage is not well understood. We hypothesize that cartilage wears due to fatigue failure in repetitive compression instead of reciprocating friction.

DESIGN

This study compares reciprocating sliding of immature bovine articular cartilage against glass in two testing configurations: (1) a stationary contact area configuration (SCA), which results in static compression, interstitial fluid depressurization, and increasing friction coefficient during reciprocating sliding, and (2) a migrating contact area configuration (MCA), which maintains pressurization and low friction while producing repetitive compressive loading in addition to reciprocating sliding. Contact pressure, sliding duration, and sliding distance were controlled to be similar between test groups.

RESULTS

SCA tests exhibited an average friction coefficient of μ=0.084±0.032, while MCA tests exhibited a lower average friction coefficient of μ=0.020±0.008 (p<10-4). Despite the lower friction, MCA cartilage samples exhibited clear surface damage with a significantly greater average surface deviation from a fitted plane after wear testing (Rq=0.125±0.095 mm) than cartilage samples slid in a SCA configuration (Rq=0.044±0.017 mm, p=0.002), which showed minimal signs of wear. Polarized light microscopy confirmed that delamination damage occurred between the superficial and middle zones of the articular cartilage in MCA samples.

CONCLUSIONS

The greatest wear was observed in the group with lowest friction coefficient, subjected to cyclical instead of static compression, implying that friction is not the primary driver of cartilage wear. Delamination between superficial and middle zones implies the main mode of wear is fatigue failure under cyclical compression, not fatigue or abrasion due to reciprocating frictional sliding.

Significance of Radiomics in Predicting Local Control for Patients with Malignant Liver Tumors Treated Using Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

We routinely deliver Stereotactic Body Radiotherapy (SBRT) in malignant liver tumors using planning computed tomography (CT) and Magnetic Resonance Images (MRI) to aid target definition. In this study, we extracted radiomic features from the MR images to predict local control (LC) post-SBRT.

MATERIALS/METHODS

We retrospectively analyzed patients with either hepatocellular cancers (HCCs) or liver metastases (Mets) treated with SBRT between Aug 2014 and Aug 2020. All patients had CT simulation followed by 1.5 Tesla planning MRI in treatment position. Contrast enhanced T1 VIBE and T2 Haste MR sequences were registered with planning CT for target definition. Radiomic features were extracted from Gross Tumor Volumes (GTV) masked out of 60 seconds post contrast T1 VIBE MR images using the Radiomics calculator tool RaCaT. The output included 480 (408 textural, 50 intensity and 22 morphological) features for each target. Principal Component Analysis of the outputs obtained from all the targets yielded 20 radiomic feature clusters after computational prioritization. These clusters were correlated to LC outcomes at various time points post-SBRT. LC was defined as non-progressive disease. Accuracy of predictions was measured by area under (AUC) receiver operating characteristic curve. Cox regression analysis was done to find univariate and multivariate clinical [HCCs vs. Mets, single vs. multiple lesions, previous local therapy (yes vs. no), GTV volume (≤40 vs. >40 cc)], radiomic and dosimetric predictors (continuous) of LC.

RESULTS

In total, 97 patients received SBRT to 122 lesions. The median dose prescribed was 45 Gy (range, 30-50 Gy). Median age was 69 years (interquartile range, IQR 61-73 yrs.). 59 patients had HCCs and 38 had Mets. 24 lesions had prior ablative therapy. 75 patients had one target, and 22 had multiple targets. Median GTV was 43.5 cc (IQR 23.4-78.6 cc). Median follow up was 16.6 months (IQR 9.7-27.2 mths). Median LC was 13.6 months (IQR 8.0-23.5 mths). On univariate analysis, histology (HCCs vs. Mets; Hazard ratio (HR) 2.9, 95% CI 1.4-6.4; p < 0.006), radiomic clusters (p < 0.006) and the max., mean, and min. doses to GTV and Planning Target Volumes correlated with improved LC (all p-values < 0.05). On multivariate analysis, histology (HCCs vs. Mets; HR 4.4, 95% CI 1.6-12.3; p = 0.004), radiomic clusters (p = 0.034) and prescription dose (p = 0.048) were significant covariates. Specifically, the 20 radiomic clusters were predictive of LC, and the accuracy of predictions showed promise with AUC values of 0.74, 0.80, and 0.81 at 12, 24, and 36 months post-SBRT, respectively. AUC values for LC in HCCs vs. Mets at 12, 24, and 36 months were 0.83, 0.77, and 0.70, and 0.66, 0.77, and 0.88, respectively.

CONCLUSION

MR-based radiomics predict LC post-SBRT in patients with malignant liver tumors. Further research focused on independent validation of the model is required to explore its clinical use.

Deep Learning of Time-Signal Intensity Curves from Dynamic Susceptibility Contrast Imaging Enables Tissue Labeling and Prediction of Survival in Glioblastoma

BACKGROUND AND PURPOSE

An autoencoder can learn representative time-signal intensity patterns to provide tissue heterogeneity measures using dynamic susceptibility contrast MR imaging. The aim of this study was to investigate whether such an autoencoder-based pattern analysis could provide interpretable tissue labeling and prognostic value in isocitrate dehydrogenase (IDH) wild-type glioblastoma.

MATERIALS AND METHODS

Preoperative dynamic susceptibility contrast MR images were obtained from 272 patients with IDH wild-type glioblastoma (training and validation, 183 and 89 patients, respectively). The autoencoder was applied to the dynamic susceptibility contrast MR imaging time-signal intensity curves of tumor and peritumoral areas. Representative perfusion patterns were defined by voxelwise K-means clustering using autoencoder latent features. Perfusion patterns were labeled by comparing parameters with anatomic reference tissues for baseline, signal drop, and percentage recovery. In the validation set (n = 89), a survival model was created from representative patterns and clinical predictors using Cox proportional hazard regression analysis, and its performance was calculated using the Harrell C-index.

RESULTS

Eighty-nine patients were enrolled. Five representative perfusion patterns were used to characterize tissues as high angiogenic tumor, low angiogenic/cellular tumor, perinecrotic lesion, infiltrated edema, and vasogenic edema. Of these, the low angiogenic/cellular tumor (hazard ratio, 2.18; P = .047) and infiltrated edema patterns (hazard ratio, 1.88; P = .009) in peritumoral areas showed significant prognostic value. The combined perfusion patterns and clinical predictors (C-index, 0.72) improved prognostication when added to clinical predictors (C-index, 0.55).

CONCLUSIONS

The autoencoder perfusion pattern analysis enabled tissue characterization of peritumoral areas, providing heterogeneity and dynamic information that may provide useful prognostic information in IDH wild-type glioblastoma.

[The status and influencing factors of presenteeism among clinical nurses: a systematic review]

Objective: To systematically review the status and factors influencing presenteeism among clinical nurses. Methods: In December 2021, CNKI, CBM, Wanfang, VIP, Web of Science, PubMed, Embase, The Cochrane Library, CINAHL, PsyclNFO and other databases were electronically searched to cross sectional studies on the current situation and factors influencing the occurrence of presenteeism among clinical nurses. The search terms mainly included presenteeism, sick at work, Stanford Presenteeism Scale, nurse, level, risk factor, influence, et al. And the search time was from the establishment of the database to November 30, 2021. Literature screening, data extraction and evaluation of the risk of bias in the included literature were done independently by two researchers, and meta-analysis was performed using Stata 15.1 software. Results: A total of 29 studies involving 13 535 clinical nurses were included.The results of the meta-analysis showed that the score of presenteeism was 17.99 [95% CI (17.02-18.95), P =0.000]. Subgroup analysis showed that presenteeism scores were higher in articles published before 2020 (ES=19.28, 95%CI: 18.41-20.15, P=0.000) and in the group of nurses aged 36 to 40 years (ES=19.27, 95%CI: 17.35~21.19, P=0.000), female (ES= 17.04, 95%CI: 14.70-19.39, P=0.000), secondary school education (ES=21.01, 95%CI: 17.76-24.26, P= 0.007), married (ES=17.49, 95%CI: 15.13-19.85, P=0.000), working for 5 to 10 years (ES=17.78, 95%CI: 16.54-19.02, P=0.000), contract (ES=17.05, 95%CI: 15.23-18.87, P=0.000), working in pediatrics (ES= 16.65, 95% CI: 15.31-17.99, P=0.000) and European region (ES =21.21, 95% CI: 20.50-21.93, P=0.000) . Conclusion: Current evidence suggests that clinical nurses are at high risk of presenteeism, which is affected by variety of factors. The managers should pay attention to the physical and mental health of nurses, identify high-risk factors as early as possible and take measures to reduce the occurrence of presenteeism and improve the quality of nursing.

Incidence and predictors of transthyretin cardiac amyloidosis in patients with degenerative aortic stenosis

Background

The approval of new therapies for treating transthyretin (TTR) cardiac amyloidosis has led to significant interest in identifying patients at high risk for this disease. Investigators have identified a correlation between severe degenerative aortic stenosis (AS) and TTR cardiac amyloidosis in older patients, with several studies finding up to 20% of patients who undergo transcatheter aortic valve replacement (TAVR) having TTR cardiac amyloidosis. These initial TAVR studies were conducted when TAVR was performed almost exclusively in high surgical risk populations. Therefore, the true incidence of TTR cardiac amyloidosis in an all-comers with severe degenerative AS referred for TAVR is unknown.

Purpose

To identify the true burden of TTR cardiac amyloidosis in a contemporary population of severe degenerative AS undergoing TAVR screening.

Methods

All patients ≥70 years with severe native valve degenerative AS seen in a multidisciplinary valve clinic were referred for technetium-99m pyrophosphate cardiac scintigraphy (PYP scan) for evaluation of cardiac amyloidosis. Diagnosis was made via combination of planar grade and heart to contralateral lung ratio, confirmed on single positron emission computed tomography/computed tomography (SPECT/CT). Patients with a positive PYP scan were referred to a heart failure clinic where they underwent testing for AL amyloidosis.

Results

Over a 10 month period, 247 patients seen in valve clinic underwent a PYP scan. Of this cohort, 203 patients ultimately underwent TAVR, 15 surgical aortic valve replacement, and 2 balloon valvuloplasty with 27 patients having not yet undergone a procedure. The positivity rate was 4% (10/247) with 1 patient having an equivocal result. The patients with a positive PYP scan had higher rate of low-flow low-gradient (LFLG) AS (64% vs 29%, p=0.006) and classical LFLG AS (27% vs 8%, p=0.02). Echocardiographic measures associated with a positive PYP scan include a lower global longitudinal strain (−10.0% vs −16.1%, p=0.008), lower average e' (4.5 vs 6.5, p=0.003), and an increased E/A ratio (1.8 vs 1.1, p=0.018).

Conclusions

The incidence of TTR amyloidosis in a contemporary, severe AS population ≥70 years undergoing TAVR screening appears much lower than previously described in the literature. Echocardiographic traits may be able to predict which patients with severe AS should undergo evaluation for TTR cardiac amyloidosis.

Funding Acknowledgement

Type of funding sources: None.

Construction of a vector-field cryogenic magnetic force microscope

Owing to the high resolution of magnetic force microscopes (MFMs) operating at low temperatures and high-applied magnetic fields, they can be employed to study various phenomena observed in topological magnetic materials and superconductors. In this study, we constructed a low-temperature MFM equipped with a 2-2-9-T vector magnet and a three-axis fiber-optic alignment system. The three-axis alignment device enables in situ calibration of the scanner at low temperatures as well as optimizes the intensity and sensitivity of the interferometer signal. A massive homebuilt vibration isolation table lowers the resonance frequency of the system and minimizes mechanical noise. Consequently, the minimum detectable force gradient of our proposed model is close to the thermodynamic limit of the cantilever. To demonstrate the low-temperature capability of the MFM, we obtained magnetic domain images of the van der Waals ferromagnet Fe₄GeTe₂ and the Abrikosov superconducting vortices of an Nb film. Furthermore, we performed field angle-dependent MFM experiments in a van der Waals magnetic insulator Cr₂Ge₂Te₆ to verify its vector-field functionality and observed a transition in the domains from the stripe to the bubble phase with respect to the magnetic field angle. The vector-field capability of our MFM can be useful for investigating various anisotropic magnetic phenomena in topological magnetic and superconducting materials.

Impact of doppler velocity index after transcatheter aortic valve replacement using Sapien-3 valve – a single centre experience

Background

Little is known about the hemodynamic performance of Edwards Sapien-3 (S3) valve after Transcatheter Aortic Valve Replacement (TAVR). Doppler velocity index (DVI) is a better indicator of prosthetic valve function as it is independent of valve size and flow, unlike mean gradient and peak velocity which are flow-dependent.

Methods

In this study, we compare outcomes based on differences in DVI among a consecutive series of patients who underwent S3 TAVR between April 2015 and December 2018. Our institutional review board approved the study and informed consents were obtained from the subjects.

Results

Among 921 patients who had follow-up echocardiograms within 30 days after TAVR, 60.8% had DVI ≤0.5, while 39.2% had DVI &gt;0.5. The median 30-day DVI was 0.47 with a standard deviation of 0.11 and mean 0.49 and interquartile range 0.41–0.55. The baseline clinical and procedural characteristics were similar between both groups with the exception of less post-dilation (36.8% vs. 47.4%; p=0.001) and greater implantation depth (2.59±1.99 vs. 2.31±1.9mm; p=0.031) with DVI ≤0.5. The rates of aortic valve calcification, pre dilation, pre-TAVR aortic regurgitation (AR) were similar. At baseline, there were no differences between both groups in mean or peak gradients or aortic velocity time integral (VTI). At 1 year, mean gradients were higher with DVI ≤0.5 (12.7±5.6 vs. 11.1±4.6 mmHg; p=0.001). DVI ≤0.5 was associated with higher peak gradients (24.2±10.2 vs. 21.4±8.7 mmHg; p=0.002), and aortic VTI (51.4±13.5 vs. 46.8±12.2 cm; p&lt;0.001) at 1 year, especially with the 26mm and 29mm prostheses. Compared with DVI&gt;0.5 group, patients in DVI&lt;0.5 group had lower baseline left ventricular ejection fraction (LVEF) (54.5±12.2% vs. 58.9±11.2%; p&lt;0.001), higher left ventricular end-diastolic volume index (LVEDVi) (54.3±20.9 vs. 49.4±17.4 ml/m2; p=0.001), higher LV end-systolic volume index (LVESVi) (25.2±16.5 vs. 21.3±12.7 ml/m2; p=0.001), and similar LV mass index (110.7±31.9 vs. 106.9±32.7 g/m2; p=0.134). 1-year mortality rates among patients who had DVI ≤0.5 compared to DVI &gt;0.5 were lower (6.6% vs. 10.6%; log-rank p=0.033), however no difference was noted at both 2 years (17.3% vs. 20.1%; log-rank p=0.151), and 3 years after TAVR (30.7% vs. 31.2%; log-rank p=0.333).

Conclusions

DVI&lt;0.5 was associated with higher peak gradients and lower baseline LVEF. DVI &lt;0.5 group patients had lower 1-year mortality but similar mortality at 2 and 3-years of follow up.

Funding Acknowledgement

Type of funding sources: None. Figure 1. All-cause SurvivalFigure 2. Hemodynamic Data

Late Clinical and Hemodynamic Outcomes in patients with degenerated bioprosthetic aortic valves undergoing transcatheter valve-in-valve implantation

Background

Clinical studies have shown promising early outcomes for valve-in-valve transcatheter aortic valve implantation (ViV-TAVI); however, the late outcomes of this procedure remain under-investigated.

Purpose

We performed the present analysis to assess the late clinical and hemodynamic outcomes of ViV-TAVI in patients with degenerated bioprosthetic aortic valves.

Methods

A comprehensive chart review was performed for eligible patients to retrieve data on procedural characteristics, admission details following the procedure, and echocardiographic parameters. Clinical outcomes included all-cause mortality, heart failure hospitalization and structural valve deterioration (SVD), as defined by VARC-II criteria, up to 5 years of follow-up. To assess the trends in mean and peak transvalvular gradients, data from the follow-up echocardiographic reports were analyzed using Syngo Dynamics imaging software.

Results

A total of 188 patients were included with a mean age of 75.8±10.4 years. Balloon- and self-expandable valves were used in 155 (82.4%) and 33 (17.6%) patients, respectively. At 30 days, 3 (1.6%) patients died and 8 (4.2%) required hospitalization for heart failure, while at 5 years, both events were recorded in 29 (15.4%) and 37 (19.7) patients, respectively. Kaplan-Meier survival analysis showed that patients with smaller surgical valves (internal diameter ≤21 mm) had a significantly higher mortality rate (log-rank p=0.021) than those with larger valves; however, no significant difference (log-rank p=0.59) was detected between different transcatheter valves (self vs. balloon-expandable). Three patients underwent re-intervention, performed via a transcatheter approach. Further, assessment of follow-up echocardiographic reports revealed 9 (4.8%) cases of SVD, as well as stable mean (16.3±6.9 at discharge and 16.9±11.3) and peak (30.3±12.1 at discharge and 30.7±18.4 at 5 years) transvalvular gradients. No difference (p&gt;0.05) was observed based on transcatheter valve type or surgical valve internal diameter in terms of mean and peak transvalvular gradients throughout the follow-up period.

Conclusion

The present study showed good clinical outcomes among patients undergoing VIV-TAVI, with stable VIV performance over a five-year period. Future long-term studies are warranted to analyze the predictors of outcomes following ViV-TAVI and explore the role of this treatment option in the life-long management of aortic stenosis.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Jennifer and Robert McNeil Donation to the Heart, Thoracic, and Vascular Institute at Cleveland Clinic. Figure 1

Outcomes of transfemoral-transcatheter aortic valve replacement with Sapien-3 valve in liver cirrhosis patients

Background

Little is known about the outcomes of liver cirrhosis patients with severe aortic stenosis (AS) who undergo transcatheter aortic valve replacement (TAVR).

Methods

We undertook a retrospective analysis of consecutive patients with severe symptomatic AS who underwent transfemoral-TAVR with Sapien-3 valve at our Clinic between April 2015 and December 2018, yielding 32 patients with liver cirrhosis on imaging including ultrasound and/or computed tomography. Their baseline characteristics, procedural and long-term outcomes after TAVR with the non-cirrhotic group were compared, along with their management strategies as per the hepatology team.

Results

Among 1028 patients, 32 were assigned to the cirrhosis, and 996 were assigned to the non-cirrhosis (control) group. Compared with the control group cirrhotic patients were slightly younger in age (74.5 vs 81.2 years), had a slightly higher BMI (31.3 vs 29.3), and had a higher incidence of prior history of myocardial infarction (38% vs 33%). Baseline variables including the history of smoking, hypertension, diabetes, and atrial fibrillation were comparable in both groups. Among cirrhotic patients (n=32), the most common etiologies were non-alcoholic steatohepatitis (NASH) (37.5%), Alcoholism (18.75%), and Hepatitis C (12.5%). The mean MELD-NA score was 11.8 and 67% of patients were Child PUGH Class A and 33% were Child PUGH Class B and all patients had a Child PUGH score of ≥5. 53% of patients (n=17) in the cirrhosis group were evaluated by Hepatology and 12.5% (n=4) were evaluated for a liver transplant but only 1 patient had a liver transplant post-TAVR. Compared with the control group cirrhotic patients had similar 1-year mortality (12% vs 12%, p=1), had a lower rate of 30-day new pacemaker post tavr (6% vs 9% p=0.85), had a higher rate of 1-year readmission for heart failure (12% vs 5% p=0.12) and similar 1-year major adverse cardiac and cerebrovascular event (MACCE) rate (15% vs 14% p=0.98)

Conclusion

Patients with severe AS undergoing TAVR with concomitant liver cirrhosis demonstrate comparable outcomes compared with their non- cirrhotic counterparts. NASH followed by alcoholic cirrhosis was found to be most common etiology.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Comparison of uniaxial and triaxial accelerometer outputs among individuals with and without Down syndrome

BACKGROUND

Using uniaxial accelerometry approach in measuring physical activity levels of individuals with Down syndrome (DS) might underestimate their energy expenditure due to the unique mediolateral walking pattern. Therefore, the purpose of this study was to examine and compare the relationship between two types of accelerometer outputs, uniaxial and triaxial, and energy expenditure in individuals with and without DS.

METHODS

Eighteen participants with DS and 19 participants without DS wore a GT3X+ accelerometer and a portable metabolic system in three different walking conditions.

RESULTS

Correlations between V̇O2 and each of the two accelerometer outputs (uniaxial: r = 0.75, triaxial: r = 0.75) were not significantly different among individuals without DS (z = 0.14, P = 0.89); however, significant differences in the relationship between V̇O2 and accelerometer outputs (uniaxial: r = 0.53, triaxial: r = 0.64) were observed among individuals with DS (z = -1.72, P < 0.046).

CONCLUSIONS

The findings suggest that when using accelerometers to measure physical activity levels for individuals with DS, triaxial outputs may better predict physical activity levels.

Understanding of the aging pattern in quantum dot light-emitting diodes using low-frequency noise

The negative and positive aging effects of quantum dot (QD) light-emitting diodes (QLEDs) have received considerable attention in recent years and various analysis methods have been discussed. Here, we introduce a new approach to understand the aging effect of QLEDs, which is to diagnose the behavior of carriers and traps at interfaces between each layer of the QLEDs and inside the layers themselves. In particular, low-frequency noise (LFN) measurement and the analysis of current in the QLEDs were introduced to investigate the trapping/de-trapping behaviors of carriers in the defect states in the devices. A flicker noise was observed before the carriers are injected into the QD emitting layer, while the exciton generation-recombination (G-R) noise and shot noise were observed when the electrons were injected. A correlated noise, which is the correlated model of the trapping/de-trapping of the carriers near and/or inside the QDs and the exciton recombination, was also observed above the turn-on voltage. In addition, when the devices were aged with a constant current source, rapid increases in the luminance and external quantum efficiency (EQE) were observed for up to 50 h. After 100 h of the current aging, however, the devices were negatively aged with the reduced EQE. The LFN analysis results imply that the aging phenomena mainly depend on the trapping/de-trapping of carriers. In addition to the LFN analysis, we also investigated the current density-voltage-luminance and capacitance-voltage characteristics of the devices to clarify the aging behaviors in QLEDs.

Efficacy of dimethyl fumarate in Japanese multiple sclerosis patients: interim analysis of randomized, double-blind APEX study and its open-label extension

Background

Current data for the use of dimethyl fumarate (DMF) in Japanese patients with relapsing-remitting multiple sclerosis (RRMS) is limited.

Objectives

To assess the efficacy of DMF in Japanese patients with RRMS.

Methods

The phase 3, multinational APEX study (ClinicalTrials.gov identifier: NCT01838668) consisted of two parts: a 24-week double-blind part where subjects were randomized to receive DMF 240 mg or placebo twice daily in East Asian and Eastern European countries, and an open-label extension part where all subjects received DMF. The primary endpoint was the total number of new gadolinium-enhancing lesions in Weeks 12-24. In this interim analysis, we report efficacy data in the Japanese subgroup (DMF n = 56; placebo n = 58) over 72 weeks, including an extension phase.

Results

DMF reduced the total number of new gadolinium-enhancing lesions in Weeks 12-24 by 85% versus placebo (p < 0.0001). At Week 24, the annualized relapse rate was also reduced by 48% with DMF, versus placebo. DMF reduced the probability of relapse from Week 8 and was sustained. The number of gadolinium-enhancing lesions was maintained through 72 weeks.

Conclusions

DMF demonstrated sustained efficacy in this Japanese subgroup. The results were consistent with those observed in studies of DMF enrolling primarily Caucasian patients.

Enhanced efficiency and high temperature stability of hybrid quantum dot light-emitting diodes using molybdenum oxide doped hole transport layer

High power efficiency (PE) and stability of quantum dot (QD) light-emitting diodes (QLEDs) are important factors for practical use in various displays. However, hybrid QLEDs consisting of an organic hole transport layer (HTL) and an inorganic electron transport layer (ETL) sometimes have poor stability due to the low thermal stability of the organic HTL. To solve the problem, here, we report enhanced efficiency, lifetime, and temperature stability in inverted and hybrid structured QLEDs by adopting a MoO₃-doped HTL. Also, to improve the electron–hole charge carrier balance, a thin insulating interlayer was used between QDs and the ETL. As a result, the QLED with the p-doped HTL exhibited the increased PE by ∼28% and longer lifetime compared to the pristine QLEDs. In addition, the QLED showed stable operation at the high temperature up to 400 K, whereas the control device failed to operate at 375 K. We systematically investigated the effect of the MoO₃-doping on the performance and thermal stability of the QLEDs. We believe that QLEDs with the p-doped HTL can be used for further QLED researches to simultaneously improve the efficiency, lifetime, and high temperature stability, which are highly required for their use in automotive and outdoor displays.

QLEDs introducing a p-doped HTL exhibit stable operation at high temperature up to 400 K.

Morphine and pholcodine-specific IgE have limited utility in the diagnosis of anaphylaxis to benzylisoquinolines

BACKGROUND

Investigation of immediate hypersensitivity reactions in the perioperative setting involves skin testing and measurement of specific IgE (sIgE) as standard practice. In the case of the neuromuscular blocking agents (NMBAs), the main allergenic epitopes have been shown to be substituted ammonium groups. Commercial assays are available for detection of sIgE to these epitopes using morphine and pholcodine substrates but questions have been raised about the effectiveness of these assays in the diagnosis of benzylisoquinoline anaphylaxis. This study was therefore undertaken to assess the effectiveness of these assays in the diagnosis of hypersensitivity reactions to this group of NMBAs.

METHODS

Analysis was carried out on all available results for patients assessed at the Royal North Shore Hospital Anaesthetic Allergy Clinic during the period June 2009 to June 2016. Standardised intradermal skin tests were performed with a panel of NMBAs. Measurement of sIgE to morphine and pholcodine was performed via the Phadia ImmunoCAP^® system.

RESULTS

For all patients with positive skin test results to NMBAs which included a benzylisoquinoline NMBA (n = 24), 75% exhibited negative sIgE to both morphine and pholcodine. Where patients were reactive to benzylisoquinoline NMBAs alone (n = 12), 100% exhibited negative sIgE results, indicating 0% sensitivity of the assays relative to skin testing, in this subgroup.

CONCLUSION

Use of sIgE testing to morphine and pholcodine in the assessment of NMBA immediate hypersensitivity is a valuable tool particularly in the case of reactions to the aminosteroid NMBAs. However, these assays are unreliable in detecting sensitisation to benzylisoquinoline NMBAs.

The effect of farrowing duration and parity on preovulatory follicular size and oxytocin release of sows at subsequent oestrus

This study examined the extent to which prolonged farrowing and parity are associated with plasma oxytocin concentrations and follicular development of oestrous sows during subsequent insemination. A total of 30 sows were allocated to two groups based on farrowing duration: (i) SHORT (n = 14): 159 ± 29 min, (ii) LONG (n = 16): 533 ± 190 min. The sows were also divided into two parity classes: (i) YOUNG (n = 14): parity 2.5 ± 0.8, (ii) OLD (n = 16): parity 6.4 ± 2.3. After weaning, the ovaries were examined daily with transrectal ultrasound. On the second day of oestrus, blood samples were collected for oxytocin (OT) assay at -15, -10, -5, 0, +1, +2, +3, +4, +6, +8, +10, +15, +20, +25, +30, +40, +50 and +60 min with a boar contact between 0 and +10 min. Boar presence stimulated an increase in OT concentrations (p < .05). During boar presence, OT in the LONG group was higher than in the SHORT group (p < .01). The sows in the OLD group had a longer farrowing duration than in the YOUNG group (p < .05). OT levels and diameters of follicles were more relevant for parity than was the duration of farrowing. We therefore conclude that the OT levels and follicular development of oestrous sows are associated due to parity but difficult to be predicted from the duration of previous farrowing.

Abstract P2-06-01: Molecular characterization of human malignant phyllodes tumors reveals potential targeted approaches

Malignant phyllodes tumor (MPT) which belong to the fibroepithelial neoplasm spectrum is a rare type of breast malignancy, and currently there is no effective targeted approach available for MPT. In this study, we tried to identify key genomic alterations and biologic pathways in MPT by whole exome and RNA sequencing of nine MPT tissues. Whole exome sequencing revealed somatic alterations in EGFR, MED12, PIK3CA, PIK3R1, PDGFRA, PDGFRB, PTEN, and TP53. Transcriptome sequencing showed dysregulation of ECM-receptor interaction, focal adhesion, and PI3K-Akt signaling in MPTs when compared to normal breast or invasive breast cancer tissues. Based on the transcriptome profiles, the MPTs were classified into two subtypes; fibrous subtype with upregulation of stromal genes such as collagens and epithelial subtype with upregulation of E-cadherin and Claudins. The molecular classification of fibrous and epithelial subtypes was validated in 28 paraffin-embedded MPT tissues. The fibrous subtype showed higher mitotic index and increased risk for recurrence when compared to the epithelial subtype. We established a patient-derived xenograft model from one fibrous subtype MPT which harbored somatic mutation in PIK3R1 and PDGFRB. In that model, targeted treatment against PIK3CA/mTOR and PDGFR pathways effectively suppressed the tumor growth in vivo. Our data provide insights on the biologic understanding of MPT and suggest a clinically relevant molecular classification. Furthermore, we show that developing effective targeted approaches in MPT can be possible with genomic profiles and patient-derived xenograft models. The clinical efficacy of targeting PDGFR and PIK3CA/mTOR pathways in MPT should be tested in future clinical trials.

Citation Format: Moon H-G, Yun J, Hong BS, Lee E, Lee H-B, Han W, Kim J-I, Noh D-Y, Heo W, Hur S, Kang W, Lee C. Molecular characterization of human malignant phyllodes tumors reveals potential targeted approaches [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-06-01.

Effects of organic loading rate on hydrogen and volatile fatty acid production and microbial community during acidogenic hydrogenesis in a continuous stirred tank reactor using molasses wastewater

AIMS

Microbial community associated with hydrogen production and volatile fatty acids (VFAs) accumulation was characterized in acidogenic hydrogenesis using molasses wastewater as a feedstock.

METHODS AND RESULTS

Hydrogen and VFAs production were measured under an organic loading rate (OLR) from 19 to 35 g-COD l^-1  day^-1 . The active microbial community was analysed using RNA-based massively parallel sequencing technique, and their correlation patterns were analysed using networking analysis. The continuous stirred tank reactor achieved stable hydrogen production at different OLR conditions, and the maximum hydrogen production rate (HPR) was 1·02 L-H₂  l^-1  day^-1 at 31·0 g-COD l^-1  day^-1 . Butyrate (50%) and acetate (38%) positively increased with increase in OLR. Total VFA production stayed around 7135 mg l^-1 during the operation period. Although Clostridiales and Lactobacillales were relatively abundant, the HPR was positively associated with Pseudomonadaceae and Micrococcineae. Total VFA and acetate, butyrate and propionate concentrations were positively correlated with lactic acid bacteria (LAB) such as Bacillales, Sporolactobacillus and Lactobacillus.

CONCLUSIONS

The close relationship between Pseudomonadaceae and Micrococcineae, and LAB play important roles for stable hydrogen and VFA production from molasses wastewater.

SIGNIFICANCE AND IMPACT OF THE STUDY

Microbial information on hydrogen and VFA production can be useful to design and operate for acidogenic hydrogenesis using high strength molasses wastewater.

Drug Delivery and Nanoformulations for the Cardiovascular System

Therapeutic delivery to the cardiovascular system may play an important role in the successful treatment of a variety of disease state, including atherosclerosis, ischemic-reperfusion injury and other types of microvascular diseases including hypertension. In this review we evaluate the different options available for the development of suitable delivery systems that include the delivery of small organic compounds [adenosin A_2A receptor agonist (CGS 21680), CYP-epoxygenases inhibitor (N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide, trans-4-[4-(3-adamantan-1-ylureido)cyclohexyloxy] benzoic acid), soluble epoxide hydrolase inhibitor (N-methylsulfonyl-12,12-dibromododec-11-enamide), PPARγ agonist (rosiglitazone) and PPARγ antagonist (T0070907)], nanoparticles, peptides, and siRNA to the cardiovascular system. Effective formulations of nanoproducts have significant potential to overcome physiological barriers and improve therapeutic outcomes in patients. As per the literature covering targeted delivery to the cardiovascular system, we found that this area is still at infancy stage, as compare to the more mature fields of tumor cancer or brain delivery (e.g. blood-brain barrier permeability) with fewer publications focused on the targeted drug delivery technologies. Additionally, we show how pharmacology needs to be well understood when considering the cardiovascular system. Therefore, we discussed in this review various receptors agonists, antagonists, activators and inhibitors which will have effects on cardiovascular system.

HPV-associated cervical cancer cells targeted by triblock copolymer gold nanoparticle curcumin combination

OBJECTIVE

Curcumin (diferuloylmethane) has promising anti-cervical cancer properties but requires a stabilizing complex such as the Pluronic triblock copolymer gold nanoparticle (GNP). The objectives were to study cytotoxicity of curcumnin and to determine the effect of copolymer GNPs curcumnin complex on cancer cell necrosis.

MATERIALS AND METHODS

The HeLa cells were maintained in Eagle Minimal Essential Medium, fetal bovine serum, and antibiotics, and passaged until 60% confluency was reached. The cells were exposed to either: (1) control medium, (2) 50 μM curcumin, (3) 100 μM curcumin, (4) 50 μM curcumnin with copolymer GNPs complex, or (5) 100 μM curcumnin with copolymer GNPs complex. The treated cells were incubated at 37°C with 5% CO(2) in air for 24 hours, and analyzed for viability, apoptosis or necrosis using the dual stains fluorescence procedure.

RESULTS

A dose-dependent increase in the HeLa necrosis was observed with increasing curcumnin concentrations. Cytotoxic effect was decreased by five- to ten-fold when the curcumin was complexed with copolymer GNPs. There were more apoptotic HeLa cells at the higher concentration of curcurnin but combination with copolymer GNPs resulted in decreased apoptosis. Cell viability was higher in curcumnin with copolymer GNPs (74.4 ± 4.8 versus 2.3 ± 2.2% live, mean ± SEM, with and without copolymer GNPs, respectively).

CONCLUSION

Curcumin increased HeLa cancer cell necrosis but its cytotoxicity was decreased by copolymer GNPs. The results suggested that this specific copolymer GNP did not enhance the curcumnin bioavailability in cultured cells possibly due to formation of copolymer GNP aggregates.

Serial transvaginal ultrasound-guided biopsy of the porcine corpus luteum in vivo

The aims of the present study was to develop and describe a transvaginal ultrasound-guided biopsy method for luteal tissue in the porcine and to evaluate the effects of the method on the reproductive tract, ovarian status and pregnancy status. Biopsies were performed in four multiparous sows on Days 9 and 15 of three consecutive oestrous cycles; the size and histological composition of the samples obtained were evaluated and the reproductive tract of the sows was monitored. Furthermore, biopsies were performed in 26 multiparous sows on Days 10 and 13 after insemination, and the pregnancy rate, gestation length and subsequent litter size were evaluated. RNA was extracted from the samples obtained and the quality and quantity were determined. Altogether, 76 biopsies were performed and 38 samples were obtained. Compared with sows from which no samples were obtained (n = 6), sows from which one or more samples were obtained (n = 24) were older (parity 5.0 ± 2.8 vs 2.2 ± 0.4, mean ± s.d.), heavier (290 ± 26 vs 244 ± 27 kg) and had higher back fat (11.4 ± 2.7 vs 6.4 ± 2.5 mm; P < 0.05 for all). No effect of the biopsies (P > 0.05) was observed on the cyclicity and reproductive organs of the sows, or on corpus luteum diameter on Day 13 (8.9 ± 1.0 vs 9.2 ± 1.1 mm), pregnancy rate (95% vs 96%), gestation length (115 ± 1 vs 115 ± 1 days) and subsequent litter size (12.7 ± 2.5 vs 13.3 ± 2.8) between sows from which samples were obtained and those from which no samples were obtained. The samples obtained had a diameter of 1 mm and contained heterogeneous tissue with various cell types. The RNA quantity was 520 ± 160 µg per sample and the RNA integrity number was 8.5 ± 1.0. In conclusion, an ultrasound-guided biopsy method for ovarian tissue, which can be used for gene expression studies, was established in the porcine. No effect on corpus luteum function was found.

Impaired development and dysfunction of endothelial progenitor cells in type 2 diabetic mice

AIM

Dysfunction of circulating endothelial progenitor cells (EPCs) has been shown to affect the development of microvascular diseases in diabetes patients. The aim of this study was to elucidate the development and mechanical dysfunction of EPCs in type 2 diabetes (T2D).

METHODS

The colony-forming capacity of EPCs and differentiation potential of bone marrow (BM) c-Kit(+)/Sca-I(+) lineage-negative mononuclear cells (KSL) were examined in T2D mice, db/db mice and KKA^y mice, using EPC colony-forming assay (EPC-CFA).

RESULTS

T2D mice had fewer BM stem/progenitor cells, and proliferation of KSL was lowest in the BM of db/db mice. In T2D mice, the frequency of large colony-forming units (CFUs) derived from BM-KSL was highly reduced, indicating dysfunction of differentiation into mature EPCs. Only a small number of BM-derived progenitors [CD34(+) KSL cells], which contribute to the supply of EPCs for postnatal neovascularization, was also found. Furthermore, in terms of their plasticity to transdifferentiate into various cell types, BM-KSL exhibited a greater potential to differentiate into granulocyte macrophages (GMs) than into other cell types.

CONCLUSION

T2D affected EPC colony formation and differentiation of stem cells to mature EPCs or haematopoietic cells. These data suggest opposing regulatory mechanisms for differentiation into mature EPCs and GMs in T2D mice.