Nesting of multiple polyhedral plasmonic nanoframes into a single entity

The development of plasmonic nanostructures with intricate nanoframe morphologies has attracted considerable interest for improving catalytic and optical properties. However, arranging multiple nanoframes in one nanostructure especially, in a solution phase remains a great challenge. Herein, we show complex nanoparticles by embedding various shapes of three-dimensional polyhedral nanoframes within a single entity through rationally designed synthetic pathways. This synthetic strategy is based on the selective deposition of platinum atoms on high surface energy facets and subsequent growth into solid platonic nanoparticles, followed by the etching of inner Au domains, leaving complex nanoframes. Our synthetic routes are rationally designed and executable on-demand with a high structural controllability. Diverse Au solid nanostructures (octahedra, truncated octahedra, cuboctahedra, and cubes) evolved into complex multi-layered nanoframes with different numbers/shapes/sizes of internal nanoframes. After coating the surface of the nanoframes with plasmonically active metal (like Ag), the materials exhibited highly enhanced electromagnetic near-field focusing embedded within the internal complicated rim architecture.

The spatial configuration of nanostructure building blocks determines the physical and optical properties of their superstructures. Here, the authors report on complex nanoparticles in which different geometric forms of nanoframes are nested into a single entity by multistep chemical reactions.

Elongated nanoporous Au networks improve somatic cell direct conversion into induced dopaminergic neurons for Parkinson's disease therapy

The efficient production of dopaminergic neurons via the direct conversion of other cell types is of interest as a potential therapeutic approach for Parkinson's disease. This study aimed to investigate the use of elongated porous gold nanorods (AuNpRs) as an enhancer of cell fate conversion. We observed that AuNpRs promoted the direct conversion of fibroblasts into dopaminergic neurons in vivo and in vitro. The extent of conversion of fibroblasts into dopaminergic neurons depended on the porosity of AuNpRs, as determined by their aspect ratio. The mechanism underlying these results involves specific AuNpR-induced transcriptional changes that altered the expression of antioxidant-related molecules. The generation of dopaminergic neurons via the direct conversion method will open a new avenue for developing a therapeutic platform for Parkinson's disease treatment. STATEMENT OF SIGNIFICANCE: In this study, we applied modified gold nanoporous materials (AuNpRs) to the direct lineage reprogramming of dopaminergic neurons. The cell reprogramming process is energy-intensive, resulting in an excess of oxidative stress. AuNpRs facilitated the direct conversion of dopaminergic neurons by ameliorating oxidative stress during the reprogramming process. We have found this mechanistic clue from high throughput studies in this research work.

6000 lines/mm blazed grating for a high-resolution x-ray spectrometer

We have designed and fabricated a high groove density blazed grating for a Resonant Inelastic X-ray Scattering spectrometer for the new Qerlin beamline at the Advanced Light Source (ALS) synchrotron facility. The gratings were fabricated using a set of nanofabrication techniques including e-beam lithography, nanoimprint, plasma etch, and anisotropic wet etching. Two gratings with groove density of 6000 lines/mm and 3000 lines/mm and optimized for operation in the 1^st and 2^nd negative diffraction order respectively were fabricated and tested. We report on fabrication details and characterization of the gratings at beamline 6.3.2 of the ALS.

Heterogeneous Component Au (Outer)-Pt (Middle)-Au (Inner) Nanorings: Synthesis and Vibrational Characterization on Middle Pt Nanorings with Surface-Enhanced Raman Scattering

We report a synthetic approach for heterometallic (Au-Pt-Au) nanorings with intertwined triple rings (NITs), wherein three differently sized metal circular nanorings concentrically overlap in a single entity. The synthetic method allows one to control the component of core nanorings (Au or Pt) with a tunable gap distance. The narrow circular nanogaps between inner and outer Au rings strongly enhance the electromagnetic near-field via intraparticle coupling of localized surface plasmon resonance, which realizes surface-enhanced Raman scattering (SERS) at the single-particle level. Importantly, when the component of the middle ring is Pt, in situ SERS measurement for electrochemical reactions on Pt domains could be monitored with electrochemical potential variations due to the near-field focusing that is assisted by plasmonically active inner and outer Au nanorings, which is not feasible with pure Pt nanoparticle systems. The resulting NIT systems are robust and may benefit the synthesis of complicated nanostructures, giving myriad applications.

Precision Determination of the Neutral Weak Form Factor of ^{48}Ca

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733  fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

All-Hot-Spot Bulk Surface-Enhanced Raman Scattering (SERS) Substrates: Attomolar Detection of Adsorbates with Designer Plasmonic Nanoparticles

Here we report a synthetic pathway toward Au truncated octahedral dual-rim nanoframes wherein two functional facets are formed including (1) eight hot nanogaps formed by hexagonal nanoframes embracing core circular nanorings for near-field focusing and (2) six flat squares that facilitate the formation of well-ordered arrays of nanoframes through self-assembly. The existence of intra-nanogaps in a single entity enables strong electromagnetic near-field focusing, allowing single-particle surface-enhanced Raman spectroscopy. Then, we built "all-hot-spot bulk SERS substrates" with those entities, wherein the presence of truncated terraces with high homogeneity in size and shape facilitate spontaneous self-assembly into a highly ordered and uniform superlattice, exhibiting a limit of detection of attomolar concentrations toward 2-naphthalenethiol, which is 6 orders lower than that of monorim counterparts. The observed low limit of detection originates from the combined synergic effect from both inter- and intraparticle coupling in a superlattice, which we dubbed "all-hot-spot bulk SERS substrates".

Plasmonic All-Frame-Faceted Octahedral Nanoframes with Eight Engraved Y-Shaped Hot Zones

We report the synthesis of all-frame-faceted octahedral nanoframes containing eight Y-shaped hot zones in a single entity where electromagnetic near-field focusing can be maximized. To realize such state-of-the-art complex nanoframes, a series of multiple stepwise bottom-up processes were executed by exploiting Au octahedral nanoparticles as the initial template. By rationally controlling the chemical reactivity of different surface facets (i.e., vertexes, edges, and terraces), the Au octahedral nanoparticles went through controlled shape transformations, leading to Au-engraved nanoparticles wherein 24 edges wrap the octahedral Au nanoparticle core. Those edges were then selectively decorated with Pt, leading to the formation of eight Pt tripods in a single entity. After etching the central Au, 3D Pt tripod frame-faceted octahedral nanoframes were achieved with high integrity. By harnessing the obtained Pt nanoframes as a scaffold, AuAg alloy-based plasmonic all-frame-faceted nanoframes were obtained after the co-reduction of Ag and Au, which generated multiple hot zones within multiple surface intra-nanogaps, creating a single-particle, surface-enhanced Raman spectroscopy enhancer platform.

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

POS0146 INCREASED RISKS OF AORTIC REGURGITATION AND ATRIAL FIBRILLATION IN RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS PATIENTS: A 10 YEAR NATIONWIDE COHORT STUDY

Background

Radiographic axial spondyloarthritis (r-axSpA) has increased risk of cardiovascular disease. Other cardiac manifestations such as conduction disturbance and valvular diseases were also suggested as co-morbidities in r-axSpA patients, however, the risk of these cardiac manifestation in r-axSpA were seldomly evaluated in large cohort.

Objectives

To compare the incidences of aortic regurgitation, atrial fibrillation (AF), and atrioventricular (AV) block II–III between r-axSpA patients and the general population (GP).

Methods

National Health Insurance Services data were used. R-axSpA patients (N = 8,877) and the age- and sex-matched GP (N = 26,631) were followed from August, 2006 to December, 2019. Incidence rates and standardized incidence ratios (SIR) of aortic regurgitation, AF, and AV block II–III were compared between these groups. Ten year incidence rates and hazard ratios (HRs) were calculated by the Kaplan–Meier method and Cox regression analysis.

Results

Incidence rates of aortic regurgitation, AV block II–III, and AF in the r-axSpA group were 0.42, 0.21, and 4.0 per 1000 person-years, respectively. In the r-axSpA group, the SIR for aortic regurgitation was highest among 40–49-year-old men (4.11). Incidence rates of aortic regurgitation and AF were higher in the r-axSpA group than in the GP group (both p < 0.001), whereas the difference was insignificant for AV block II–III. In multivariate analysis, HRs for aortic regurgitation and AF were higher in the r-axSpA group than in the GP group (HR (95% confidence interval) = 2.55 (1.49–4.37) and 1.20 (1.04–1.39), respectively), but the difference was insignificant for AV block II–III.

Conclusion

Compared with the GP, r-axSpA patients are at increased risk of aortic regurgitation and AF, but not AV block II–III. These patients should be carefully monitored for occurrence of aortic regurgitation and AF.

References

[1]Agca R, Heslinga SC, Rollefstad S, et al. EULAR recommendations for cardiovascular disease risk management in patients with rheumatoid arthritis and other forms of inflammatory joint disorders: 2015/2016 update. Ann Rheum Dis 2017; 76: 17-28.

[2]Szabo SM, Levy AR, Rao SR, et al. Increased risk of cardiovascular and cerebrovascular diseases in individuals with ankylosing spondylitis: a population-based study. Arthritis Rheum 2011; 63: 3294-3304.

[3]Morovatdar N, Watts GF, Bondarsahebi Y, et al. Ankylosing Spondylitis and risk of Cardiac Arrhythmia and Conduction Disorders: A systematic review and meta analysis. Curr Cardiol Rev 2021.

[4]Bengtsson K, Forsblad-d’Elia H, Lie E, et al. Risk of cardiac rhythm disturbances and aortic regurgitation in different spondyloarthritis subtypes in comparison with general population: a register-based study from Sweden. Ann Rheum Dis 2018; 77: 541-548.

[5]Dik VK, Peters MJ, Dijkmans PA, et al. The relationship between disease-related characteristics and conduction disturbances in ankylosing spondylitis. Scand J Rheumatol 2010; 39: 38-41.

Disclosure of Interests

None declared

AB0307 MERKEL CELL CARCINOMA RECURRENCE RISK IS LOWER IN PATIENTS WITH AUTOIMMUNE DISEASE THAN IN THOSE WITH OTHER TYPES OF IMMUNE SUPPRESSION

Background

Merkel cell carcinoma (MCC) is twice as likely to recur in immunosuppressed (IS) patients as in immunocompetent (IC) patients. Iatrogenic IS due to autoimmune disease (AD) may influence prognosis differently than intrinsic IS such as due to hematologic malignancy. Moreover, modification of IS medication may improve prognosis.

Objectives

Our objective was to evaluate the risk of MCC recurrence among patients with AD diseases relative to other immunosuppressive conditions among 762 MCC patients from an Institutional review board-approved registry.

Methods

We categorized patients into 3 groups: IS due to AD (ISAD); IS from other causes (lSnon-AD) such as hematologic malignancy, solid organ transplant, human immunodeficiency virus; or immune competent (n=31, 70, and 661 respectively). ISAD patients were subcategorized into rheumatoid arthritis (RA) (ADRA, n=13) vs. AD except for RA (ADnon-RA, n=18). Descriptive statistics were used to compare the features of different characteristics in each group. Kaplan-Meier survival curves were constructed to assess the cumulative incidence of recurrence in different patient groups. In order to estimate the associations between baseline patient characteristics and the risk of MCC recurrence, Fine and Gray regression models were used with death as a competing risk for recurrence. The multivariable models adjusted for age, sex, and extent of MCC at initial presentation.

Results

Patients with ISAD had lower stage disease (local disease: 58% vs. 36%, p = 0.003) and smaller primary tumors than ISnon-AD (<= 2 cm: 83% vs. 57%, p=0.023). After adjusting for age, sex, and stage, ISAD patients (ADRA and ADnon-RA) overall had a 54% higher recurrence rate (hazard ratio (HR): 1.54, p=0.21) than IC patients. In comparison, ISnon-AD group had a 165% higher recurrence rate (HR: 2.65, p<0.001) than IC patients (Figure 1). When considered separately, ADRA pts appeared to have a similar recurrence rate as IC pts (HR: 1.19, p=0.76) while ADnon-RA pts had a higher recurrence rate (HR: 1.83, p=0.16) relative to IC pts. At the time of MCC diagnosis, 80% (n=24) of AD pts were on IS medication including conventional disease modifying drugs, biologics, or oral steroids. After MCC diagnosis, 22% (5 patients) stopped all immunosuppressive medications. Among patients on biologics, 89% (8/9 pts) elected to stop the drug. Eleven pts with AD experienced recurrences. Our study was underpowered to demonstrate associations regarding use of a particular immunosuppressive medication and MCC recurrence.

Figure 1.

Cumulative incidence of Merkel cell carcinoma recurrence in different patient groups.

AD = autoimmune disease; IS = immunosuppressed; RA = rheumatoid arthritis.There were 4/13, 8/18, 49/70, and 217/661 recurrences in the RA, ADnon-RA, other immunosuppressed, and not chronically immunosuppressed groups, respectively. Follow-up time ranged from 26 days to 16 years, with median follow-up times of 4.7 years, 1.6 years, 1.6 years, and 3.9 years for the RA, ADnon-RA, other immunosuppressed and not chronically immunosuppressed groups, respectively.

Conclusion

In this cohort, pts with AD appeared to have a better prognosis than intrinsic IS, with RA conferring very little risk above that for immune competent pts.

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

COVID-19 susceptibility and clinical outcomes in autoimmune inflammatory rheumatic diseases (AIRDs): a systematic review and meta-analysis

OBJECTIVE

This meta-analysis aims to assess the susceptibility to and clinical outcomes of COVID-19 in autoimmune inflammatory rheumatic disease (AIRD) and following AIRD drug use.

MATERIALS AND METHODS

We included observational and case-controlled studies assessing susceptibility and clinical outcomes of COVID-19 in patients with AIRD as well as the clinical outcomes of COVID-19 with or without use of steroids and conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

RESULTS

Meta-analysis including three studies showed that patients with AIRD are not more susceptible to COVID-19 compared to patients without AIRD or the general population (OR: 1.11, 95% CI: 0.58 to 2.14). Incidence of severe outcomes of COVID-19 (OR: 1.34, 95% CI: 0.76 to 2.35) and COVID-19 related death (OR: 1.21, 95% CI: 0.68 to 2.16) also did not show significant difference. The clinical outcomes of COVID-19 among AIRD patients with and without csDMARD or steroid showed that both use of steroid (OR: 1.69, 95% CI: 0.96 to 2.98) or csDMARD (OR: 1.35, 95% CI: 0.63 to 3.08) had no effect on clinical outcomes of COVID-19.

CONCLUSIONS

AIRD does not increase susceptibility to COVID-19, not affecting the clinical outcome of COVID-19. Similarly, the use of steroids or csDMARDs for AIRD does not worsen the clinical outcome.

New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering over a Range of Spin-0 Nuclei

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

Pepsinogens and Gastrin Demonstrate Low Discrimination for Gastric Precancerous Lesions in a Multi-Ethnic United States Cohort

Early identification of gastric precancerous lesions, including atrophic gastritis (AG) and intestinal metaplasia (IM), may improve gastric cancer detection and prevention. Because AG and IM are generally asymptomatic, many of the estimated 15 million Americans who carry these lesions remain undiagnosed.¹ AG and IM are associated with either active or prior Helicobacter pylori (Hp) infection. Hp infection leads to perturbations in the serum concentration of gastric hormones pepsinogen I (PGI), pepsinogen II, the pepsinogen I/II ratio (PGR), gastrin-17 (G-17), and Hp IgG.^2,3 In East Asia and other regions with high burden of Hp infection and gastric cancer, these biomarkers have been used as screening tools for AG and IM.⁴ However, there exists limited data on the sensitivity and discrimination of these serologic markers in low-Hp-prevalence populations, such as the United States.