Meta-Lens Particle Image Velocimetry

Fluid flow behavior is visualized through particle image velocimetry (PIV) for understanding and studying experimental fluid dynamics. However, traditional PIV methods require multiple cameras and conventional lens systems for image acquisition to resolve multi-dimensional velocity fields. In turn, it introduces complexity to the entire system. Meta-lenses are advanced flat optical devices composed of artificial nanoantenna arrays. It can manipulate the wavefront of light with the advantages of ultrathin, compact, and no spherical aberration. Meta-lenses offer novel functionalities and promise to replace traditional optical imaging systems. Here, a binocular meta-lens PIV technique is proposed, where a pair of GaN meta-lenses are fabricated on one substrate and integrated with a imaging sensor to form a compact binocular PIV system. The meta-lens weigh only 116 mg, much lighter than commercial lenses. The 3D velocity field can be obtained by the binocular disparity and particle image displacement information of fluid flow. The measurement error of vortex-ring diameter is ≈1.25% experimentally validates via a Reynolds-number (Re) 2000 vortex-ring. This work demonstrates a new development trend for the PIV technique for rejuvenating traditional flow diagnostic tools toward a more compact, easy-to-deploy technique. It enables further miniaturization and low-power systems for portable, field-use, and space-constrained PIV applications.

Fabrication of Mie-resonant silicon nanoparticles using laser annealing for surface-enhanced fluorescence spectroscopy

Silicon nanostructures with unique Mie resonances have garnered considerable attention in the field of nanophotonics. Here, we present a simple and efficient method for the fabrication of silicon (Si) nanoparticle substrates using continuous-wave (CW) laser annealing. The resulting silicon nanoparticles exhibit Mie resonances in the visible region, and their resonant wavelengths can be precisely controlled. Notably, laser-annealed silicon nanoparticle substrates show a 60-fold enhancement in fluorescence. This tunable and fluorescence-enhancing silicon nanoparticle platform has tremendous potential for highly sensitive fluorescence sensing and biomedical imaging applications.

Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433

SS 433 is a microquasar, a stellar binary system that launches collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.) and found an energy-dependent shift in the apparent position of the gamma-ray emission from the parsec-scale jets. These observations trace the energetic electron population and indicate that inverse Compton scattering is the emission mechanism of the gamma rays. Our modeling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system, at distances of 25 to 30 parsecs, and that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons.

High-Resolution Metalens Imaging with Sequential Artificial Intelligence Models

An analysis of the optical response of a GaN-based metalens was conducted alongside the utilization of two sequential artificial intelligence (AI) models in addressing the occasional issues of blurriness and color cast in captured images. The optical loss of the metalens in the blue spectral range was found to have resulted in the color cast of images. Autoencoder and CodeFormer sequential models were employed in order to correct the color cast and reconstruct image details, respectively. Said sequential models successfully addressed the color cast and reconstructed details for all of the allocated face image categories. Subsequently, the CIE 1931 chromaticity diagrams and peak signal-to-noise ratio analysis provided numerical evidence of the AI models' effectiveness in image reconstruction. Furthermore, the AI models can still repair the image without blue information. Overall, the integration of metalens and artificial intelligence models marks a breakthrough in enhancing the performance of full-color metalens-based imaging systems.

Intelligent Phase Contrast Meta-Microscope System

Phase contrast imaging techniques enable the visualization of disparities in the refractive index among various materials. However, these techniques usually come with a cost: the need for bulky, inflexible, and complicated configurations. Here, we propose and experimentally demonstrate an ultracompact meta-microscope, a novel imaging platform designed to accomplish both optical and digital phase contrast imaging. The optical phase contrast imaging system is composed of a pair of metalenses and an intermediate spiral phase metasurface located at the Fourier plane. The performance of the system in generating edge-enhanced images is validated by imaging a variety of human cells, including lung cell lines BEAS-2B, CLY1, and H1299 and other types. Additionally, we integrate the ResNet deep learning model into the meta-microscope to transform bright-field images into edge-enhanced images with high contrast accuracy. This technology promises to aid in the development of innovative miniature optical systems for biomedical and clinical applications.

Label-free visualization of photosynthetic microbial biofilms using mid-infrared photothermal and autofluorescence imaging

The formation of photosynthetic microbial biofilms comprising multispecies biomolecules, such as extracellular polymeric substances (EPSs), and microbial cells play pivotal roles in maintaining or stimulating their biological functions. Although there are numerous studies on photosynthetic microbial biofilms, the spatial distribution of EPS components that are vital for microbial biofilm formation, such as exopolysaccharides and proteins, is not well understood. Visualization of photosynthetic microbial biofilms requires label-free methods, because labelling EPSs results in structural changes or aggregation. Raman spectroscopy is useful for label-free visualization of biofilm constituents based on chemical contrast. However, interference resulting from the bright autofluorescence of photosynthetic molecules and the low detection efficiency of Raman scattering make visualization a challenge. Herein, we visualized photosynthetic microbial biofilms in a label-free manner using a super-resolution optical infrared absorption imaging technique, called mid-infrared photothermal (MIP) microscopy. By leveraging the advantages of MIP microscopy, such as its sub-micrometer spatial resolution, autofluorescence-free features, and high detection sensitivity, the distribution of cyanobacteria and their extracellular polysaccharides in the biofilm matrix were successfully visualized. This showed that cyanobacterial cells were aligned along acidic/sulfated polysaccharides in the extracellular environment. Furthermore, spectroscopic analyses elucidated that during formation of biofilms, sulfated polysaccharides initially form linear structures followed by entrapment of cyanobacterial cells. The present study provides the foundation for further studies on the formation, structure, and biological functions of microbial biofilms.

Varifocal Metalenses: Harnessing Polarization-Dependent Superposition for Continuous Focal Length Control

Traditional varifocal lenses are bulky and mechanically complex. Emerging active metalenses promise compactness and design flexibility but face issues like mechanical tuning reliability and nonlinear focal length tuning due to additional medium requirements. In this work, we propose a varifocal metalens design based on superimposing light intensity distributions from two orthogonal polarization states. This approach enables continuous and precise focal length control within the visible spectrum, while maintaining relatively high focusing efficiencies (∼41% in simulation and ∼28% in measurement) and quality. In experimental validation, the metalens exhibited flexible tunability, with the focal length continuously adjustable between two spatial positions upon variation of the incident polarization angle. The MTF results showed high contrast reproduction and sharp imaging, with a Strehl ratio of >0.7 for all polarization angles. With compactness, design flexibility, and high focusing quality, the proposed varifocal metalens holds potential for diverse applications, advancing adaptive and versatile optical devices.

Dynamic measurement of an angular Goos-Hänchen shift at a surface plasmon resonance in liquid

We developed a surface plasmon resonance (SPR)-enhanced angular Goos-Hänchen (GH) shift measurement system capable of tracking small refractive index changes with high sensitivity in a liquid environment. Our method can be performed in angular interrogation schemes, where we demonstrate a simple zero-finding algorithm to locate the SPR angle instead of the complicated data processing algorithms used in conventional sensors. We also propose a displacement interrogation scheme for dynamic measurement of small refractive index changes in the sample. The main advantage of our method is the controllability of the measured displacement by standard geometrical optics, allowing measurement sensitivity enhancement without the need to modify the sensor material.

Comparison of the Efficacy of Low Dose Tadalafil with Tamsulosin against Lower Urinary Tract Symptoms and Sexual Dysfunction after Low Dose Rate Prostate Brachytherapy

PURPOSE/OBJECTIVE(S)

Patients with clinically localized prostate cancer (PCa) can be curatively treated with different modalities, including low dose rate (LDR) prostate brachytherapy (PB). LDR-PB allows the patient a relatively short recovery time compared with other treatment modalities such as prostatectomy. However, PB might exert distinct impact on quality of life, lower urinary tract symptoms (LUTS) and sexual dysfunction (SD) are two major concerns. The aim of present study was to assess prospectively the efficacy of low dose tadalafil treatment on both SD and LUTS compared with tamsulosin treatment in patients treated PB for localized PCa.

MATERIALS/METHODS

Patients scheduled for PB with I-125 seeds for low or intermediate-risk localized PCa at our institution were eligible for this study. The prescribed dose was set at 160 gray. Participants were randomized into two groups; those started treating with a daily use of 0.2 mg of tamsulosin hydrochloride or 5 mg of tadalafil just after PB. The duration of the study was 12 months and the patients were assessed for urinary and sexual function status at baseline, and 1, 3, 6, and 12 months after PB. The primary study endpoints were both changes from baseline in urinary and sexual function status.

RESULTS

Between July 2015 and August 2020, 120 participants were enrolled in this study. The median age was 68 years with the median PSA of 6.5 ng/ml. A total 15 patients were excluded within 6 months after randomization. All subjective LUTS findings, including International Prostate Symptom Score (IPSS), and Over Active Bladder Symptom Score (OABSS), were significantly deteriorated at 1, 3, and 6 months after PB compared with baseline in both groups, respectively (p<0.05). Among objective LUTS findings, a significant decrease in maximum urinary flow rate (Qmax) was found at 1, 3, 6, and 12 months after PB compared with baseline in both groups, respectively (p<0.05). A significant increase in post void residual urine (PVR) was found at 1, 3, and 6 months after PB compared to baseline in tadalafil group, whereas no significant increase was seen in tamsulosin group. There were no statistically significant differences between the 2 groups in scores of the total International Index of Erectile Function (IIEF)-15 and Erection Hardness Score (EHS) before and at 1 month post PB. The EHS was significantly higher in tadalafil group compared with tamsulosin group at 3, 6 and 12 months (p = 0.001, p = 0.004, and p = 0.019, respectively). The EHS after PB in tadalafil group was not significantly decreased from baseline.

CONCLUSION

After LDR-PB, tamsulosin treatment significantly decreased PVR compared with tadalafil. On the other hand, tadalafil contributed to maintain erection hardness compared with tamsulosin.

Contrast Injection from an Intermediate Catheter Placed in an Intradural Artery is Associated with Contrast-Induced Encephalopathy following Neurointervention

BACKGROUND AND PURPOSE

Contrast-induced encephalopathy can result from neurotoxicity of contrast medium in the affected area. The development of intermediate catheters has allowed guidance of catheters to more distal arteries. This study focused on the association between contrast-induced encephalopathy and contrast injection from an intermediate catheter guided into a distal intradural artery during neurointervention for cerebral aneurysms.

MATERIALS AND METHODS

We retrospectively reviewed 420 consecutive aneurysms in 396 patients who underwent neurointervention for extracranial aneurysms and unruptured intracranial aneurysms at our institution from February 2012 to January 2023. Patients were divided into a group with contrast-induced encephalopathy and a group without. To identify risk factors for contrast-induced encephalopathy, we compared clinical, anatomic, and procedural factors between groups by multivariate logistic regression analysis and stepwise selection.

RESULTS

Among the 396 patients who underwent neurointervention for cerebral aneurysms, 14 (3.5%) developed contrast-induced encephalopathy. Compared with the group without contrast-induced encephalopathy, the group with contrast-induced encephalopathy showed significantly higher rates of patients on hemodialysis, previously treated aneurysms, intradural placement of a catheter for angiography, nonionic contrast medium, and flow-diversion procedures in univariate analyses. Stepwise multivariate logistic regression analysis revealed intradural placement of a catheter for angiography (OR = 40.4; 95% CI, 8.63-189) and previously treated aneurysms (OR = 8.20; 95% CI, 2.26-29.6) as independent predictors of contrast-induced encephalopathy.

CONCLUSIONS

Contrast injection from an intradural artery and retreatment of recurrent aneurysms were major risk factors for contrast-induced encephalopathy. Attention should be paid to the location of the intermediate catheter for angiography to avoid developing contrast-induced encephalopathy.

Single-cell infrared vibrational analysis by optical trapping mid-infrared photothermal microscopy

Single-cell analysis by means of vibrational spectroscopy combined with optical trapping is a reliable platform for unveiling cell-to-cell heterogeneities in vast populations. Although infrared (IR) vibrational spectroscopy provides rich molecular fingerprint information on biological samples in a label-free manner, its application with optical trapping has never been achieved due to weak gradient forces generated by the diffraction-limited focused IR beam and strong background of water absorption. Herein, we present single-cell IR vibrational analysis that incorporates mid-infrared photothermal (MIP) microscopy with optical trapping. Optically trapped single polymer particles and red blood cells (RBCs) in blood could be chemically identified owing to their IR vibrational fingerprints. This single-cell IR vibrational analysis further allowed us to probe the chemical heterogeneities of RBCs originating from the variation in the intracellular characteristics. Our demonstration paves the way for the IR vibrational analysis of single cells and chemical characterization in various fields.

High-frequency spin torque oscillation in orthogonal magnetization disks with strong biquadratic magnetic coupling

In this study, we numerically investigate the spin transfer torque oscillation (STO) in a magnetic orthogonal configuration by introducing a strong biquadratic magnetic coupling. The orthogonal configuration consists of top and bottom layers with in-plane and perpendicular magnetic anisotropy sandwiching a nonmagnetic spacer. The advantage of an orthogonal configuration is the high efficiency of spin transfer torque leading a high STO frequency; however, maintaining the STO in a wide range of electric current is challenging. By introducing biquadratic magnetic coupling into the orthogonal structure of FePt/spacer/Co₉₀Fe₁₀, Ni₈₀Fe₂₀ or Ni, we were able to expand the electric current region in which the stable STO is realized, resulting in a relatively high STO frequency. For example, approximately 50 GHz can be achieved in an Ni layer at a current density of 5.5 × 10⁷ A/cm². In addition, we investigated two types of initial magnetic state: out-of-plane and in-plane magnetic saturation; this leads to a vortex and an in-plane magnetic domain structure after relaxation, respectively. The transient time before the stable STO was reduced to between 0.5 and 1.8 ns by changing the initial state from out-of-plane to in-plane.

Utility of 5-aminolaevulinic acid fluorescence-guided endoscopic biopsy for malignant mesothelioma in a cat and dog

Malignant mesothelioma (MM) is uncommon in cats and dogs and can be challenging to diagnose. Adequate tissue sampling is required for superior diagnostic accuracy. Protoporphyrin IX, a metabolite of 5-aminolaevulinic acid (5-ALA), is a photosensitiser for photodynamic diagnosis (PDD). To the best of our knowledge, no study has reported the use of 5-ALA-PDD to detect MM in veterinary medicine. The present study describes the use of 5-ALA-PDD for MM diagnosis in a cat and dog, as well as the effectiveness of intracavitary chemotherapy. We evaluated the use of PDD with 5-ALA hydrochloride (5-ALA-PDD) in two cases of MM. A 12-year-old cat presented with a 1-month history of respiratory distress, and a 9-year-old dog presented with a 3-month history of mild abdominal distention. We endoscopically biopsied lesions in both the cases using 5-ALA-PDD. Histopathological examination revealed mesothelioma, and immunohistochemical staining was positive for calretinin. Both patients were treated with carboplatin. The cat died of respiratory failure. Although, the dog's condition improved 21 days after the first chemotherapeutic drug administration, the dog died on day 684 owing to cardiac-related issues. 5-ALA-PDD is thus, safe and feasible for the diagnosis of MM in veterinary medicine.

Poor Health Behaviors among Housebound Japanese Community-Dwelling Older Adults Due to Prolonged Self-Restraint during the First COVID-19 Pandemic: A Cross-Sectional Survey

BACKGROUND

Prolonged self-restraining behaviors induced by the coronavirus disease 2019 (COVID-19) pandemic's containment measures can limit various positive health behaviors.

OBJECTIVE

We examined the decline in going-out and certain other positive health behaviors and investigated the relationship between excessive decreases in going-out frequency and declining engagement in positive health behaviors among community-dwelling older adults during the self-restraint period.

DESIGN

This study employed a cross-sectional survey design.

SETTING

This study was conducted in Nishi Tokyo City, Tokyo, Japan.

PARTICIPANTS

The participants were 294 respondents (150 women) aged 50 years and older who lived in public housing that were permitted to be surveyed during the self-restraint period.

MEASUREMENTS

Their pre-pandemic going-out frequency around February 2020 and going-out frequency during the self-restraint period starting in April 2020 were reported. We mainly assessed the existence of home health behaviors (i.e., exercise, in-person and phone conversations, and healthy diet). A self-report questionnaire was used to obtain data.

RESULTS

Going-out frequency decreased in 41.2% of the 294 respondents owing to the government's request for self-restraint. In total, 13 individuals had been going out less than one time per week (housebound) before the request. Of the 281 people who were not housebound before the government's self-restraint request, 13.9% were newly housebound. Newly housebound individuals were 5.3 times less likely to exercise, had 2.1 times fewer social contacts, and 2.6 times less balanced or healthy diets than those who maintained their frequency of going out.

CONCLUSIONS

Prolonged self-restraint due to the COVID-19 pandemic may lead to housebound status and poor health behaviors. Public health intervention is needed to prevent excessive self-restraint, along with new measures integrating information and communication technologies to enable older adults to live active lives.

Impact of the Comprehensive Awareness Modification of Mouth, Chewing and Meal (CAMCAM) Program on the Attitude and Behavior Towards Oral Health and Eating Habits as Well as the Condition of Oral Frailty: A Pilot Study

OBJECTIVES

Preserving sufficient oral function and maintaining aadequate nutrition are essential for preventing physical frailty and the following long-term care. We recently developed the 6-month Comprehensive Awareness Modification of Mouth, Chewing And Meal (CAMCAM) program, in which participants gather monthly to learn about oral health and nutrition while eating a textured lunch together. This study examined whether the CAMCAM program could improve attitude and behavior towards oral health, mastication, and diet as well as ameliorate oral frailty in community-dwelling older adults.

DESIGN

Single-arm pre-post comparison study.

SETTING AND PARTICIPANTS

A total of 271 community-dwelling adults (72.3 ± 5.7 years of age; 159 women [58.7%]) in 4 Japanese municipalities were recruited, of which 249 participants (92%) were assessed at the final evaluation.

INTERVENTION

Participants gathered once a month at community centers to learn about oral health and nutrition while eating a "munchy" textured lunch containing proper nutrition.

MEASUREMENTS

Oral frailty, frailty, and eating behavior were evaluated with the Oral Frailty Index-8 (OFI-8), Kihon checklist (KCL), and CAMCAM checklist, respectively. Participants were divided into Oral frailty (OF) and Robust groups according to OFI-8 scores. The differences in KCL and CAMCAM checklist results between the OF and Robust groups were statistically tested along with changes in scores after the program.

RESULTS

KCL and CAMCAM checklist scores were significantly lower in the OF group at the initial assessment. OFI-8 and KCL findings were significantly improved in the OF group after completing the program (all P <0.05). Regarding the CAMCAM checklist, awareness of chewing improved significantly in the Robust group (P=0.009), with a similar tendency in the OF group (P=0.080).

CONCLUSION

The findings of this pilot study suggest that the CAMCAM program may improve both oral and systemic frailty in addition to attitudes towards chewing, oral health, and meals, especially in individuals with oral frailty. The CAMCAM program merits expansion as a community-based frailty prevention program.

Atezolizumab plus bevacizumab versus lenvatinib or sorafenib in non-viral unresectable hepatocellular carcinoma: an international propensity score matching analysis

BACKGROUND

A growing body of evidence suggests that non-viral hepatocellular carcinoma (HCC) might benefit less from immunotherapy.

MATERIALS AND METHODS

We carried out a retrospective analysis of prospectively collected data from consecutive patients with non-viral advanced HCC, treated with atezolizumab plus bevacizumab, lenvatinib, or sorafenib, in 36 centers in 4 countries (Italy, Japan, Republic of Korea, and UK). The primary endpoint was overall survival (OS) with atezolizumab plus bevacizumab versus lenvatinib. Secondary endpoints were progression-free survival (PFS) with atezolizumab plus bevacizumab versus lenvatinib, and OS and PFS with atezolizumab plus bevacizumab versus sorafenib. For the primary and secondary endpoints, we carried out the analysis on the whole population first, and then we divided the cohort into two groups: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) population and non-NAFLD/NASH population.

RESULTS

One hundred and ninety patients received atezolizumab plus bevacizumab, 569 patients received lenvatinib, and 210 patients received sorafenib. In the whole population, multivariate analysis showed that treatment with lenvatinib was associated with a longer OS [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.44-0.95; P = 0.0268] and PFS (HR 0.67; 95% CI 0.51-0.86; P = 0.002) compared to atezolizumab plus bevacizumab. In the NAFLD/NASH population, multivariate analysis confirmed that lenvatinib treatment was associated with a longer OS (HR 0.46; 95% CI 0.26-0.84; P = 0.0110) and PFS (HR 0.55; 95% CI 0.38-0.82; P = 0.031) compared to atezolizumab plus bevacizumab. In the subgroup of non-NAFLD/NASH patients, no difference in OS or PFS was observed between patients treated with lenvatinib and those treated with atezolizumab plus bevacizumab. All these results were confirmed following propensity score matching analysis. By comparing patients receiving atezolizumab plus bevacizumab versus sorafenib, no statistically significant difference in survival was observed.

CONCLUSIONS

The present analysis conducted on a large number of advanced non-viral HCC patients showed for the first time that treatment with lenvatinib is associated with a significant survival benefit compared to atezolizumab plus bevacizumab, in particular in patients with NAFLD/NASH-related HCC.

Prognostic impact of acute kidney injury following tricuspid transcatheter edge-to-edge repair

Background

A considerable risk of acute kidney injury (AKI) following transcatheter interventions without iodinated contrast agents has also been recognized; however, little is known about the incidence and clinical relevance of post-procedural AKI in patients undergoing transcatheter edge-to-edge repair (TEER) for tricuspid regurgitation (TR).

Purpose

This study aimed to investigate the prognostic impact and predictors of post-procedural AKI following TEER for TR.

Methods

We retrospectively analyzed 218 consecutive patients who underwent TEER for TR. Post-procedural AKI was defined as an increase in serum creatinine of ≥0.3 mg/dl within 48 hours or of ≥50% within seven days after the procedure, compared to baseline. Procedural success was defined as at least one grade reduction in TR severity upon discharge. We determined the association between post-procedural AKI and the composite outcome consisting of all-cause mortality and re-hospitalization due to heart failure within one year after the procedure.

Results

Overall, the mean age of the patients was 79±7 years, and 46.3% of the patients were male. Post-procedural AKI occurred in 32 patients (14.7%) (Figure 1). Among baseline characteristics, male sex and an estimated glomerular filtration rate of &lt;60 ml/min/m2 were associated with the occurrence of AKI. In addition, patients without procedural success had a higher incidence of post-procedural AKI (30.4% vs. 1.8%; p=0.024).

Patients with AKI had a higher incidence of in-hospital mortality compared to those without AKI (12.5% vs. 1.1%; p=0.005). Moreover, AKI was associated with the incidence of the composite outcome within one year after TEER for TR (adjusted hazard ratio: 2.06; 95% confidence interval: 1.11–3.84; p=0.023). In addition, our restricted cubic spline curve showed that a post-procedural increase in the creatinine level within seven days after the procedure was associated with a linear trend of the risk of the composite outcome after TEER (Figure 2).

Conclusions

Post-procedural AKI occurred in 14.7% of patients undergoing TEER for TR, despite the absence of iodinated contrast agents, which was associated with worse clinical outcomes. Male sex and CKD at baseline were related to the occurrence of AKI, and the procedural success of TEER was associated with a lower incidence of AKI. Our findings highlight the clinical impact of AKI following TEER for TR and should help with identifying patients at high risk of AKI.

Funding Acknowledgement

Type of funding sources: None.

Effectiveness of transcatheter edge-to-edge repair for atrial secondary mitral regurgitation

Background

Atrial secondary mitral regurgitation (ASMR) is a subtype of SMR that is characterized by normal left ventricular (LV) function, an enlarged left atrium and mitral annulus, and flattened leaflets. This anatomical feature is different from ventricular SMR (VSMR) and might therefore impact the procedural results of transcatheter edge-to-edge repair (TEER). The effectiveness and durability of TEER in patients with ASMR has not yet been well-studied.

Purpose

This study aimed to investigate the effectiveness of TEER and anatomical characteristics related to optimal MR reduction in patients with ASMR.

Methods

We retrospectively analyzed consecutive patients who underwent MitraClip at our institution. ASMR was defined as cases that met all of the following criteria: 1) normal mitral leaflets without organic disorder, 2) LV ejection fraction &gt;50%, and 3) absence of LV enlargement and segmental abnormality. The primary outcome measure was MR reduction to ≤1+, and its predictors were explored in a logistic regression analysis. Leaflet-to-annulus index (LAI) was measured using the mid-esophageal long-axis view in the A2-P2 segment as follows: (anterior leaflet length + posterior leaflet length) / anteroposterior length of the mitral annulus.

Results

Among 415 patients with SMR, 118 patients met the criteria for ASMR (mean age: 80±8 years; male: 39.8%) (Figure 1). Patients with ASMR had a larger mitral annulus diameter, shorter mobile posterior leaflet length, and smaller coaptation depth compared to those with VSMR.

The technical success rate was 90.7%, and the MR reduction to ≤1+ after TEER was achieved in 94 (79.7%) patients with ASMR, which was comparable with VSMR. The in-hospital mortality rate was 2.5%. In multivariable logistic analysis, a large left-atrial (LA) volume index and a low LAI were associated with a lower rate of MR reduction to ≤1+ after TEER for ASMR (odds ratio [OR]: 0.98; 95% confidence interval [CI]: 0.97–0.99, and OR per 0.1 increase: 1.98; 95% CI: 1.13–3.45, respectively). The combined assessment of the LA volume index and LAI stratified the risk of residual MR ≥2+ after TEER (Figure 2).

In addition, the use of a newer generation of the MitraClip systems (NTR/XTR or G4 systems) was associated with a higher rate of MR reduction to ≤1+ compared to older generations (OR: 4.65; 95% CI: 1.67–13.00).

Conclusions

TEER with the MitraClip system achieved a high rate of MR reduction to ≤1+ in patients with ASMR. Furthermore, the new generations of the MitraClip system may provide a more effective reduction in ASMR. Although our findings suggest that TEER with the MitraClip system is a safe and feasible approach in patients with ASMR, the combined assessment of the LA volume index and LAI might be useful to refine the device selection for transcatheter mitral valve treatment in this subgroup of SMR patients.

Funding Acknowledgement

Type of funding sources: None.

Right ventricular ejection fraction assessed by computed tomography in patients undergoing transcatheter tricuspid valve intervention

Background

The role of right-ventricular (RV) function in patients with tricuspid regurgitation (TR) undergoing transcatheter tricuspid valve interventions (TTVI) is poorly understood. Although cardiac computed tomography (CCT) provides elaborate three-dimensional (3D) visualization of the entire anatomy of the RV and theoretically allows to assess the global RV systolic function. Nevertheless, the utility of the functional assessments of the RV using CCT remains unclear in patients undergoing TTVI.

Purpose

This study investigated the association of right-ventricular ejection fraction (RVEF) assessed by CCT with clinical outcome in patients undergoing TTVI.

Methods

We retrospectively assessed 3D-RVEF by using pre-procedural CCT images in patients undergoing TTVI with either edge-to-edge repair or annuloplasty device. RV dysfunction (RVD) was defined as a CT-RVEF &lt;45%. The primary outcome was a composite outcome, consisting of all-cause mortality and hospitalization due to heart failure, within one year after TTVI.

Results

Of 157 patients, 58 (36.9%) presented with CT-RVEF &lt;45%. Patients with CT-RVEF &lt;45% were more likely to be male, to have a previous history of coronary artery disease, and had higher EuroSCORE II and a lower LVEF compared to those with CT-RVEF ≥45%, while the severity of TR was comparable between the groups.

Among the patients with CT-RVEF &lt;45%, acute procedural success was achieved in 93.1%, and in-hospital mortality was 1.7%, which were comparable to those with CT-RVEF ≥45%.

Patients with CT-RVEF &lt;45% had an improvement in New York Heart Association functional class at follow-up compared to baseline; however, CT-RVEF &lt;45% was associated with a higher risk of the composite outcome (adjusted hazard ratio: 3.23; 95% confidence interval: 1.52–6.88; p=0.002) (Figure 1). Furthermore, CT-RVEF had an additional value to stratify the risk of the composite outcome beyond two-dimensional transthoracic echocardiographic (TTE) assessments (Figure 2).

In addition, patients with CT-RVEF &lt;45% exhibited an attenuated association between a reduction in TR to &lt;3+ and a lower incidence of the composite outcome after TTVI compared to those with CT-RVEF ≥45%.

Conclusions

TTVI is safe and feasible regardless of baseline RV function, while RVD, defined as 3D-RVEF &lt;45%, is associated with a higher risk of the composite outcomes within one year after TTVI. Furthermore, our findings suggest that the prognostic benefits of TR reduction might be attenuated in patients with RVD. Given the additional prognostic value of CT-RVEF to the conventional echocardiographic assessments, the assessments of 3D-RVEF with CCT may refine the patient selection for TTVI.

Funding Acknowledgement

Type of funding sources: None.

Refining the accuracy of right ventricular-pulmonary arterial coupling in patients undergoing transcatheter tricuspid valve treatment

Background

Assessing right-ventricular (RV) function is paramount for risk stratification but remains challenging in patients with TR. RV-pulmonary artery (PA) coupling seems more feasible for the assessment of RV function.

Methods

We assessed RV-PA coupling by the ratio of TAPSE and PASP at baseline, in which PASP was measured both by echocardiography (ePASP) and invasively using a right-heart catheter (iPASP). We also assessed the RV fractional-area change (RVFAC) as measured by transthoracic echocardiography. Participants for the present study comprised patients undergoing TTVR from June 2015 to July 2021 at the University Hospital of Bonn. Patients lacking either echocardiographic or invasive measurements for the assessment of RV-PA coupling were excluded from the analysis. The outcome was defined as a composite of mortality and rehospitalization due to heart failure within one year after the procedure.

Results

A total of 206 patients were included in the present analysis. The participants were at an advanced age (78.5±7.1 years), predominantly female (58.3%), and at a high risk for surgery (EuroSCORE II: 7.4±4.8%). Massive/torrential TR was observed in 100 of these patients. With the median follow-up duration of 201 days (interquartile range 98–424 days), the outcome occurred in 57 patients. Compared to TAPSE/ePASP, TAPSE/iPASP showed better predictability for the outcome: the AUCs were 0.582 for TAPSE/ePASP and increased to 0.714 when iPASP was applied to the formula (i.e. TAPSE/iPASP). The trend was also true for RV-PA coupling using RVFAC (AUCs: 0.561 for RVFAC/ePASP, 0.693 for RVFAC/iPASP). There was a significant correlation between ePASP and iPASP, whereas the correlation was attenuated in patients with TR beyond severe (i.e. massive/torrential TR) (interaction p = 0.01). In addition, a semiquantitative echocardiographic estimation of right atrial (RA) pressure was not correlated with the invasive measurement.

Conclusion

The present analysis confirms that RV-PA coupling, measured as TAPSE/PASP, is a powerful predictor of mortality and rehospitalization due to heart failure in patients undergoing TTVR. The predictability is even more improved if PA pressure is measured invasively and applied to the formulas.

Funding Acknowledgement

Type of funding sources: None.

Validation of expert criteria proposed by the “German Cardiac Society” for predicting procedural complexity in transcatheter edge-to-edge mitral valve repair

Background

Following up on the original EVEREST criteria and several years of procedural experience, the German Cardiac Society (GCS) proposed refined criteria indicating morphological complexity in transcatheter edge-to-edge mitral valve repair (TEER) procedures which so far have not been validated.

Methods

In a retrospective analysis of transesophageal echocardiography images of consecutive patients undergoing TEER in two high-volume centres, complexity was classified according to GCS criteria as optimal (neither characteristics of “complex” nor “very complex', see Table 1), complex (any of the “complex” criteria but no “very complex” criteria) and very complex (any of the “very complex” criteria). Associations with the procedural outcome, reintervention, survival, and heart failure rehospitalization were tested.

Results

633 patients (mean age 79 years, range 50 to 96 years, 59% male) were included, with 35% having dominant primary and 65% having dominant secondary mitral regurgitation (MR). 19% of patients were classified as having optimal, 40% as complex, and 41% as very complex morphologies. Successful clip implantation and reduction in MR ≤2 at discharge were achieved in 100% and 97% in the optimal, in 96% and 88% in the complex, and in 95% and 88% in the very complex morphologies, respectively (p for difference 0.13 and 0.42). The rate of successful clip deployment was significantly lower and the rate of reintervention significantly higher in patients with a mitral valve orifice area ≤3 cm2, compared to patients with a mitral valve orifice area &gt;3 cm2. Pathology extent of MR likely requiring &gt;2 clips was significantly associated with a lower rate of MR reduction to grade ≤2. Midterm (median follow-up time 640 days) mortality or hospitalization due to heart failure was significantly higher in patients with a posterior mitral leaflet length of 7–10 mm.

Conclusion

In the setting of experienced heart valve centres only a few of the complexity criteria proposed by the GCS impact on procedural and clinical outcomes. Even in the case of complex or very complex mitral valve morphology, TEER can be performed effectively with reduction of MR to ≤2 in 88% of cases.

Funding Acknowledgement

Type of funding sources: None.

Search for Dark Matter Annihilation Signals in the H.E.S.S. Inner Galaxy Survey

The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented γ-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant γ-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section ⟨σv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach ⟨σv⟩ values of 3.7×10^{-26}  cm^{3} s^{-1} for 1.5 TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2×10^{-26}  cm^{3} s^{-1} for 0.7 TeV DM mass in the τ^{+}τ^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based γ-ray observations thus probe ⟨σv⟩ values expected from thermal-relic annihilating TeV DM particles.

Enteric viruses replicate in salivary glands and infect through saliva

Enteric viruses like norovirus, rotavirus and astrovirus have long been accepted as spreading in the population through fecal-oral transmission: viruses are shed into feces from one host and enter the oral cavity of another, bypassing salivary glands (SGs) and reaching the intestines to replicate, be shed in feces and repeat the transmission cycle1. Yet there are viruses (for example, rabies) that infect the SGs2,3, making the oral cavity one site of replication and saliva one conduit of transmission. Here we report that enteric viruses productively and persistently infect SGs, reaching titres comparable to those in the intestines. We demonstrate that enteric viruses get released into the saliva, identifying a second route of viral transmission. This is particularly significant for infected infants, whose saliva directly transmits enteric viruses to their mothers' mammary glands through backflow during suckling. This sidesteps the conventional gut-mammary axis route4 and leads to a rapid surge in maternal milk secretory IgA antibodies5,6. Lastly, we show that SG-derived spheroids7 and cell lines8 can replicate and propagate enteric viruses, generating a scalable and manageable system of production. Collectively, our research uncovers a new transmission route for enteric viruses with implications for therapeutics, diagnostics and importantly sanitation measures to prevent spread through saliva.

P-610 Endoplasmic reticulum stress-induced Notch signaling stimulates cumulus-oocyte complex expansion in PCOS

Study question

Does endoplasmic reticulum (ER) stress and Notch signaling affect cumulus-oocyte complex (COC) expansion in pathophysiology of polycystic ovary syndrome (PCOS)?

Summary answer

Notch signaling is induced via activation of ER stress in granulosa cells (GCs) of PCOS and stimulates COC expansion that is abrogated by Notch inhibition.

What is known already

PCOS presents a variety of symptoms including ovarian dysfunction which is caused by various local factors in follicular microenvironment; among them, ER stress and following activation of unfolded protein response are critical, causing ovarian fibrosis, growth arrest of antral follicles and other ovarian dysfunctions. While Notch signaling pathway plays an important role of various ovarian functions such as ovarian development, follicle growth, luteinization and steroid hormone synthesis, the potential interaction between Notch signaling and ER stress in ovarian function is not determined.

Study design, size, duration

To examine expression levels of Notch signaling, ovaries and granulosa-lutein cells (GLCs) were collected from PCOS patients undergoing surgery or IVF. Human GLCs were collected from follicular fluid of IVF patients and cultured under ER-stressed condition. COCs obtained from PMSG-primed mice were subjected to examine the in vitro effects of ER stress activation and Notch inhibition on COC expansion. To examine the in vivo effects of Notch inhibition, dehydroepiandrosterone-induced PCOS mouse model was used.

Participants/materials, setting, methods

The expression levels of Notch signaling in ovaries and GLCs were investigated by immunohistochemistry and real time qPCR. To examine whether Notch signaling is activated by ER stress, human GLCs were incubated with ER stress inducer or inhibitor and ATF4 was knocked down by RNA interference. To investigate COC expansion level, murine COCs were cultured under ER stress condition with/without Notch signaling inhibitor. The COCs were collected from PCOS mice treated with/without Notch inhibitor.

Main results and the role of chance

We found that the expression levels of Notch2 and Hey2, a transcription factor activated by Notch signaling, were upregulated in GCs of antral follicles from PCOS patients and PCOS mice by using immunohistochemical analysis. Similarly, mRNA levels of these genes were higher in GLCs from PCOS patients than those from control patients. Notch signaling was induced in cultured human GLCs incubated with an ER stress inducer, tunicamycin; the effect was abrogated by incubation with an ER stress inhibitor, tauroursodeoxycholic acid (TUDCA), or knockdown of activating transcription factor 4 (ATF4, a transcription factor induced by ER stress). These findings suggest that Notch signaling is induced by ER stress via ATF4 pathway in human GCs. Measuring under a microscope, the area of expanded COCs was increased in cultured murine COCs incubated with tunicamycin, while this stimulatory effect of tunicamycin was abrogated by adding a Notch signaling inhibitor, DAPT. The area of expanded COCs obtained from PCOS model mice was increased compared to control mice, while administration of DAPT to these mice reduced the area. These results suggest that ER stress-induced Notch signaling stimulate COC expansion contributing PCOS pathophysiology.

Limitations, reasons for caution

COC expansion area was measured only in PCOS model mouse; it is unknown whether COC expansion is induced in PCOS patients. This point requires further investigation in PCOS patients.

Wider implications of the findings

Our findings suggest that ER stress-induced Notch signaling affects COC expansion, associated with ovulatory dysfunction in PCOS. The detailed understandings of PCOS pathophysiology may be beneficial for substantial clinical implications and inhibition of ER stress or Notch signaling may serve as a novel therapeutic approach for PCOS.

Trial registration number

This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) (19k09749, 19k24045, 19k24021, 21k16808, 21j12871,), a grant from the Takeda Science Foundation, a grant from The Tokyo Society of Medical Science, a grant from The Japan Society of Fertility Preservation, and a grant from The Japan Society for Menopause and Women’s Health (JMWH) (a JMWH Bayer Grant).

Social Detachment Influenced Muscle Mass and Strength during the COVID-19 Pandemic in Japanese Community-Dwelling Older Women

Social detachment due to coronavirus disease (COVID-19) has caused a decline in physical activity, leading to sarcopenia and frailty in older adults. This study aimed to compare muscle mass, strength, and function values in older women before and after the first wave of the COVID-19 pandemic (April-May 2020). Furthermore, changes in muscle measures across women who experienced different levels of impact on their social participation due to the COVID-19 pandemic were examined. Muscle mass (total, trunk, and appendicular muscle), grip strength, oral motor skills, social interactions (social network and participation), and social support were assessed in 46 Japanese community-dwelling older women (mean, 77.5 y; range 66-93 y) before and after the first wave of the COVID-19 pandemic. Trunk muscle mass significantly decreased after the first wave of the pandemic. When comparing changed values between the enhanced/maintained and reduced group during the pandemic, significant group difference was observed in trunk muscular mass, grip strength, and oral motor skills. Intriguingly, those who enhanced social participation had a positive change of grip strength values, showing that social participation might influence muscle function during the COVID-19 pandemic.

Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE, [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to a month after its 2021 outburst, observed using the High Energy Stereoscopic System. The VHE emission has a similar temporal profile to lower-energy GeV emission, indicating a common origin, with a two-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic-rays to very high energies.

Highly Stable Polymer Coating on Silver Nanoparticles for Efficient Plasmonic Enhancement of Fluorescence

Surface coating of plasmonic nanoparticles is of huge importance to suppress fluorescence quenching in plasmon-enhanced fluorescence sensing. Herein, a one-pot method for synthesizing polymer-coated silver nanoparticles was developed using a functional polymer conjugated with disulfide-containing anchoring groups. The disulfides played a crucial role in covalently bonding polymers to the surface of the silver nanoparticles. The covalent bond enabled the polymer layer to form a long-term stable coating on the silver nanoparticles. The polymer layer coated was adequately thin to efficiently achieve plasmonic enhancement of fluorescence and also thick enough to effectively suppress quenching of fluorescence, achieving a huge net enhancement of fluorescence. The polymer-coated plasmonic nanoparticles are a promising platform for demonstrating highly sensitive biosensing for medical diagnostics.

Sensitivity analysis in a radiological impact assessment of a nuclear power plant discharge. A comparison of the Morris, Spearman and Sobol' approaches

This paper compares the Morris, Spearman and Sobol' methods of sensitivity analysis in radiological risk assessment. The determination of the most influential parameters on model with regards to the propagation of their uncertainties to output variables, is of greatest interest. This study aims to determine the relative importance of parameters uncertainties on the dose calculation uncertainty in the framework of a scenario of routine discharges discussed in the context of an IAEA working group. The scenario considers atmospheric and liquid discharges of three different types of radionuclides (¹⁴C, tritium as HTO and ^110mAg) from a nuclear power plant located by the side of a river. It is concluded that the most reliable and practical method according to the ability of ranking influential parameters and the easiness of its application is the Spearman method. As key result, the three first influential variables for annual total dose for all pathways and all radionuclides were the water dissolved inorganic carbon concentration, the volatilisation rate constant and the soil layer solid liquid distribution in ¹⁴C.

Ascending palatine branch from the lingual artery with multiple other variations of the external carotid artery

The external carotid artery (ECA) is the major blood supply for structures in the head and neck. Typically, it has 8 separate branches; but there are many anatomical variations, making it difficult to predict surgical outcomes and complications without 3-dimensional imaging. This case study focuses on a cadaver with multiple anatomical variations in the ECA, i.e., lingual, facial, occipital, ascending pharyngeal, and posterior auricular arteries, found during routine dissection of the right cadaveric neck. We also discuss the incidences of several other anatomical variations of the ECA branches and their surgical implications and potential complications.

Structure-activity relationships of antifungal phenylpropanoid derivatives and their synergy with n-dodecanol and fluconazole

trans-Anethole (anethole) is a phenylpropanoid; with other drugs, it exhibits synergistic activity against several fungi and is expected to be used in new therapies that cause fewer patient side effects. However, the detailed substructure(s) of the molecule responsible for this synergy has not been fully elucidated. We investigated the structure-activity relationships of phenylpropanoids and related derivatives, with particular attention on the methoxy group and the double bond of the propenyl group in anethole, as well as the length of the p-alkyl chain in p-alkylanisoles. Antifungal potency was largely related to p-alkyl chain length and the methoxy group of anethole, but not to the double bond of its propenyl group. Production of reactive oxygen species also played a role in these fungicidal activities. Inhibition of drug efflux was associated with the length of the p-alkyl chain and the double bond of the propenyl group in anethole, but not with the methoxy group. Although a desirable synergy was observed between n-dodecanol and anethole or p-alkylanisoles with a length of C2-C6 in alkyl chains, it cannot be explained away as being solely due to the inhibition of drug efflux. Similar results were obtained when phenylpropanoid derivatives were combined with fluconazole against Candida albicans.

Mass Equilibration and Fluctuations in the Angular Momentum Dependent Dynamics of Heavy Element Synthesis Reactions

Mass and angle distributions for the ^{52}Cr+^{198}Pt and ^{54}Cr+^{196}Pt reactions (both forming ^{250}No) were measured and subtracted, giving new information on fast quasifission mass evolution, and the first direct determination of the dependence of sticking times on angular momentum. TDHF calculations showed good agreement with average experimental values, but experimental mass distributions unexpectedly extended to symmetric splits while the peak yield remained close to the initial masses. This implies a strong role of fluctuations in mass division early in the collision, giving insights into the transition from fast energy dissipative deep-inelastic collisions to quasifission.

Impact of leaflet-to-annulus index on residual tricuspid regurgitation following transcatheter edge-to-edge tricuspid valve repair

Introduction

Edge-to-edge transcatheter tricuspid valve repair (TTVR) is a promising treatment option for tricuspid regurgitation (TR), and it is required to identify anatomical parameters to predict the procedural success of TTVR.

Purpose

In this study, we assessed leaflet-to-annulus index (LAI), a simple tool to evaluate the remodeling of tricuspid annulus in relation to the leaflets, and investigated the association of the LAI with residual TR after edge-to-edge TTVR.

Methods

Consecutive 140 patients with symptomatic TR who underwent edge-to-edge TTVR from June 2015 to July 2020 were enrolled. The LAI was calculated using preprocedural transesophageal echocardiography and was defined as follows: (anterior leaflet length + septal leaflet length)/anteroseptal tricuspid annulus diameter (Figure 1). Primary outcome was residual TR ≥3+ at discharge, and patients were allocated into two groups as follows: residual TR ≥3+ and &lt;3+. Secondary outcome was the composite outcome, consisting of all-cause mortality and heart failure hospitalization, within one year after TTVR.

Results

Of the 140 patients, 43 patients had residual TR ≥3+ after TTVR. The patients with residual TR ≥3+ had lower LAI compared to those with residual TR &lt;3+ (1.06±0.10 vs. 1.13±0.09; p=0.001). Multivariable analysis revealed that LAI was associated with residual TR ≥3+ (odds ratio [by 0.1 increase]: 0.57; 95% confidence interval [95% CI]: 0.35–0.94; p=0.02), independently of baseline TR severity, location of TR jet, and coaptation gap size (Table 1). Patients with residual TR ≥3+ had a higher incidence of the composite outcome within one year after TTVR (34.9% vs. 18.6%; log-rank p=0.04) and residual TR ≥3+ was an independent predictor of the composite outcome within one year (hazard ratio: 2.04; 95% CI: 1.01–4.11; p=0.04).

Conclusion

Lower LAI is associated with residual TR ≥3+ after edge-to-edge TTVR, which itself was a significant predictor of the one-year composite outcome. Our findings suggest that LAI is a useful tool to identify patients to be successfully treated with edge-to-edge TTVR.

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

Basic Study of Extensional Flow Mixing for the Dispersion of Carbon Nanotubes in Polypropylene by Using Capillary Extrusion

This study evaluated the mixing effect of simple uniaxial extensional flow for the dispersion of multiwalled carbon nanotubes (MWCNTs) into polypropylene (PP) as a nonpolar matrix. An only converging flow allowed for a high strain rate and was suitable for the compounding process. The extensional flow was characterized from the entrance pressure drop (ΔP0) at the converging section. Thus, in this study, capillary extrusion was employed to generate uniaxial extensional flow. Based on the hypothesis that the dispersion of nanofillers depends on the magnitude of flow-induced stress, ΔP0, which related to extensional stress, was measured directly during capillary extrusion by using an orifice die. The influences of the mass flow rate and the hole diameter in the orifice die, which affected ΔP0, on the extrusion of PP nanocomposites with an MWCNT loading of 1.0 wt.% were studied. The extruded samples were collected, and the dispersion state was evaluated based on the melt viscoelastic properties, volume resistivity, and morphological observations by optical microscopy (OM) and transmission electron microscopy (TEM). The agglomeration area of the MWCNTs decreased with higher ΔP0 (higher mass flow rate and smaller hole diameter), which increased the uniformity of the dispersion. Moreover, the influence of the length-to-diameter (L/D) ratio of the hole in the capillary die on the dispersion state of the MWCNTs was investigated. A higher L/D ratio of the capillary die did not improve the dispersion state, although shear and extensional stresses were provided.

Enarodustat to treat anemia in chronic kidney disease

Anemia is a common complication in patients with chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) are the standard therapy for anemia in CKD. It has been expected that hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibition may have the potential to provide therapeutic benefits over pre-existing ESAs for anemia in CKD. Enarodustat (JTZ-951) is an oral HIF-PH inhibitor. In preclinical studies, enarodustat has been found to increase HIF-alpha proteins, erythropoietin production and erythropoiesis. Enarodustat also shows efficient iron utilization in iron-related parameters during erythropoiesis. Clinical trials have shown that enarodustat improved anemia both in non-dialysis-dependent CKD patients and dialysis patients. The safety results in clinical trials demonstrate that enarodustat is generally well tolerated. On the basis of these results, enarodustat was approved in September 2020 in Japan for the treatment of anemia associated with CKD. This manuscript will review enarodustat, its pharmacological characteristics in preclinical studies, and its efficacy and safety in clinical trials with anemic patients in CKD.

Varifocal Metalens for Optical Sectioning Fluorescence Microscopy

Fluorescence microscopy with optical sectioning capabilities is extensively utilized in biological research to obtain three-dimensional structural images of volumetric samples. Tunable lenses have been applied in microscopy for axial scanning to acquire multiplane images. However, images acquired by conventional tunable lenses suffer from spherical aberration and distortions. Here, we design, fabricate, and implement a dielectric Moiré metalens for fluorescence imaging. The Moiré metalens consists of two complementary phase metasurfaces, with variable focal length, ranging from ∼10 to ∼125 mm at 532 nm by tuning mutual angles. In addition, a telecentric configuration using the Moiré metalens is designed for high-contrast multiplane fluorescence imaging. The performance of our system is evaluated by optically sectioned images obtained from HiLo illumination of fluorescently labeled beads, as well as ex vivo mice intestine tissue samples. The compact design of the varifocal metalens may find important applications in fluorescence microscopy and endoscopy for clinical purposes.

Metamaterial perfect absorber simulations for intensifying the thermal gradient across a thermoelectric device

The thermal gradient across a thermoelectric device is the key to convert heat energy into electricity. Here, we propose a metamaterial perfect absorber (MPA) that increases the thermal gradient across a thermoelectric device by local heat generation through absorbing thermal radiation emitted from an infinite-size blackbody radiator. The MPA, when attached on top of a bismuth telluride thermoelectric device, generates local heat that propagates to the device, resulting in an additional thermal gradient. The amount of local heat generated at the MPA and the output power of the thermoelectric device loaded with the MPA are examined through numerical calculations.

Effects of H3 and H4 histones acetylation and bindings of CREB binding protein and p300 at the promoter on hepatic expression of gamma-glutamyltransferase gene in a streptozotocin-induced moderate hypoinsulinemic rat model

Gamma-glutamyltransferase (GGT), a marker of liver disease, has been shown to be associated with increased risk of diabetes and relative insulin secretion deficiency. However, the mechanism of hepatic Ggt regulation has not been explored fully. In this study, we made a concerted effort to understand the mechanism by investigating the effects of acetylation of histones H3 and H4, and bindings of histone acetyltransferases, CREB binding protein (CBP) and p300, at the Ggt promoter on the regulation of the expression of Ggt gene in the livers of streptozotocin (STZ)-induced moderate hypoinsulinemia rat model. The rats treated with STZ showed remarkably higher serum GGT level and hepatic Ggt/GGT expression than the untreated control rats. Furthermore, the acetylation of histones H3 and H4, and the binding of CBP not p300 at the Ggt promoter regions were significantly higher in the livers of STZ rats than those of the control rats. These results suggest that an enhanced hepatic expression of Ggt is associated with increased acetylation of histones H3 and H4 and CBP binding at the Ggt promoter in STZ-induced moderate hypoinsulinemic rats.

Three-dimensional nanoprinting via charged aerosol jets

Three-dimensional (3D) printing^1-9 has revolutionized manufacturing processes for electronics^10-12, optics^13-15, energy^16,17, robotics¹⁸, bioengineering^19-21 and sensing²². Downscaling 3D printing²³ will enable applications that take advantage of the properties of micro- and nanostructures^24,25. However, existing techniques for 3D nanoprinting of metals require a polymer-metal mixture, metallic salts or rheological inks, limiting the choice of material and the purity of the resulting structures. Aerosol lithography has previously been used to assemble arrays of high-purity 3D metal nanostructures on a prepatterned substrate^26,27, but in limited geometries^26-30. Here we introduce a technique for direct 3D printing of arrays of metal nanostructures with flexible geometry and feature sizes down to hundreds of nanometres, using various materials. The printing process occurs in a dry atmosphere, without the need for polymers or inks. Instead, ions and charged aerosol particles are directed onto a dielectric mask containing an array of holes that floats over a biased silicon substrate. The ions accumulate around each hole, generating electrostatic lenses that focus the charged aerosol particles into nanoscale jets. These jets are guided by converged electric-field lines that form under the hole-containing mask, which acts similarly to the nozzle of a conventional 3D printer, enabling 3D printing of aerosol particles onto the silicon substrate. By moving the substrate during printing, we successfully print various 3D structures, including helices, overhanging nanopillars, rings and letters. In addition, to demonstrate the potential applications of our technique, we printed an array of vertical split-ring resonator structures. In combination with other 3D-printing methods, we expect our 3D-nanoprinting technique to enable substantial advances in nanofabrication.

A novel orexin antagonist from a natural plant was discovered using zebrafish behavioural analysis

OBJECTIVE

Phenotypic screening is one of the most practical approaches to the identification of mediators of behaviour, since it is difficult to model brain function in vitro, at a cellular level. We used a zebrafish (Danio rerio) behavioural assay to discover novel, natural, neuroactive compounds.

MATERIALS AND METHODS

A zebrafish behavioural assay was performed for seven natural compounds, obtained from plants. The behavioural profiles were compared to those of known psychoactive drugs. We characterised a natural compound exhibiting a behaviour profile similar to that of suvorexant, using in silico, in vitro and microarray expression analysis.

RESULTS

The behavioural analysis performed in this study classified central nervous system drugs according to their mechanism. Zebrafish treated with a natural compound, 8b-(4'-Hydroxytigloyloxy) costunolide (8b), showed behaviour profiles similar to those of zebrafish treated with suvorexant, a known orexin antagonist. This behavioural assay was validated using in silico and in vitro assays, which revealed that the new compound was a dual orexin receptor antagonist. In addition, transcriptome analysis suggested that 8b might regulate the nuclear factor-κB (NF-κB) related pathway.

CONCLUSIONS

We conclude that zebrafish phenotypic screening, combined with in silico assays and gene expression profiling, is a useful strategy to discover and characterize novel therapeutic compounds, including natural products.