Efficient Source of Shaped Single Photons Based on an Integrated Diamond Nanophotonic System

An efficient, scalable source of shaped single photons that can be directly integrated with optical fiber networks and quantum memories is at the heart of many protocols in quantum information science. We demonstrate a deterministic source of arbitrarily temporally shaped single-photon pulses with high efficiency [detection efficiency=14.9%] and purity [g^{(2)}(0)=0.0168] and streams of up to 11 consecutively detected single photons using a silicon-vacancy center in a highly directional fiber-integrated diamond nanophotonic cavity. Combined with previously demonstrated spin-photon entangling gates, this system enables on-demand generation of streams of correlated photons such as cluster states and could be used as a resource for robust transmission and processing of quantum information.

AB1237 COMPARISON BETWEEN ENZYME IMMUNOASSAY AND CHEMILUMINESCENCE TO DETERMINE THE CONCENTRATION OF SERUM CALPROTECTIN AND ITS ASSOCIATION WITH CLINICAL VARIABLES IN PEDIATRIC RHEUMATOLOGY

Background

Serum calprotectin (SC) is an emerging biomarker in the measurement of inflammation. It can be determined by different techniques, such as enzyme immunoassay (EIA) or chemiluminescence (CLIA). However, there are no studies comparing whether there is a correlation between the two diagnostic methods in paediatric rheumatologic diseases.

Objectives

(i) To assess whether there are differences between serum calprotectin (SC) levels determined by EIA (Bühlmann) method and CLIA (QUANTA Flash) in pediatric age patients with systemic autoimmune rheumatic disease (SARD). (ii) To evaluate which clinical and analytical variables are associated with an increase of SC in each method.

Methods

Analytical cross-sectional study that included patients from a pediatric rheumatology specialized unit between 02/2017 and 05/2021. We included 41 patients with SARD who had at least one SC analysis determined by EIA in their routine controls (144 serum) and afterwards had SC determined again, this time using the CLIA method.

The collected variables were sex, age, remission according to clinical judgment, swollen joint count according to physical examination (PE Count) and ultrasound (US Count), Juvenile Arthritis Disease Activity Score according to physical examination (PE JADAS-27) and ultrasound (US JADAS-27), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

As for the statistical analysis, intraclass correlation (ICC) and paired samples t-test were performed to compare the two methods. Univariate linear regression was performed to study the association between EIA, CLIA and both clinical and analytical variables.

Results

We included 41 patients, 50.1% were women with a mean age (± SD) of 13.1 (± 3.8) years. The details of their descriptive characteristics were: mean SC (EIA) of 3.1 (±1.8) µg/ml, mean SC (CLIA) of 2.5 (±1.6) µg/ml, mean CRP of 2.6 (± 6.5) mg/l, mean ESR of 10.1 (± 11) mm/h, and mean PE JADAS-27 of 2.8 (± 8). Most frequent diagnosis was oligoarticular juvenile idiopathic arthritis (JIA) (24.4%), followed by enthesitis-related (ERA) JIA (12.2%) and polyarticular JIA (12.2%), familial Mediterranean fever (FMF) (9.8%), psoriatic JIA (4.9%), systemic JIA (4.9%) and syndrome of periodic fever, aphtous stomatitis, pharyngitis, and cervical adenitis (PFAPA) (4.9%), vasculitis (4.8%), and undifferentiated JIA (2.4%). Clinical diagnosis was unspecific in 9.8% of the patients. In our sample, 66.7% were in clinical remission at the discretion of the specialist.

A statistically significant Pearson’s CCI of 0.77 (95%CI 0.70-0.83; p=0.00) was observed as a single measure between EIA and CLIA and with an average of 0.87 (95%CI=0.82-0.91; p=0.000). Figure 1 shows the dispersion of this correlation.

On the other hand, we observed a statistically significant difference in the mean between both methods of 0.58 (95%CI=0.40-0.77; p=0.000), observing a greater difference in SC (EIA) > 4 µg/ml.

A significant association was observed between EIA and clinical remission, joint count, JADAS and CRP; and also between CLIA and clinical remission, JADAS and CRP. The analysis performed is shown in Table 1.

Table 1.

Association between EIA and CLIA with clinical and analytical variables.

RemissionPE CountUS CountPE JADASUS JADASbpbpbpbpbpSC(EIA)0.430.0110.140.0270.080.0240.090.0000.060.000SC(CLIA)0.530.000-0.000.9450.310.3200.050.0210.040.015SexGenderESRCRPbpbpbpbpSC(EIA)0.000.9970.050.2070.000.4870.050.027SC(CLIA)-0.240.3620.010.7950.020.1050.080.000

b, regression coefficient; p, statistical significance.

Conclusion

There is a good correlation between EIA and CLIA methods to determine SC in pediatric patients with SARD. Significant differences were observed between both methods above the value of 4 µg/ml. This fact could be explained by methodological differences, since CLIA discriminates better at higher values than EIA.

An association was observed between both methods and variables of remission or disease activity.

Disclosure of Interests

None declared

Optical Entanglement of Distinguishable Quantum Emitters

Solid-state quantum emitters are promising candidates for the realization of quantum networks, owing to their long-lived spin memories, high-fidelity local operations, and optical connectivity for long-range entanglement. However, due to differences in local environment, solid-state emitters typically feature a range of distinct transition frequencies, which makes it challenging to create optically mediated entanglement between arbitrary emitter pairs. We propose and demonstrate an efficient method for entangling emitters with optical transitions separated by many linewidths. In our approach, electro-optic modulators enable a single photon to herald a parity measurement on a pair of spin qubits. We experimentally demonstrate the protocol using two silicon-vacancy centers in a diamond nanophotonic cavity, with optical transitions separated by 7.4 GHz. Working with distinguishable emitters allows for individual qubit addressing and readout, enabling parallel control and entanglement of both colocated and spatially separated emitters, a key step toward scaling up quantum information processing systems.

Resting heart rate and cardiovascular outcomes in patients with atrial fibrillation: CODE-AF registry

Funding Acknowledgements

Type of funding sources: None.

Background

The prognostic significance of resting heart rate and its therapeutic target in atrial fibrillation (AF) is uncertain.

Purpose

The aim of this study was to investigate the relationships between resting heart rate and cardiovascular outcomes in patients with AF.

Methods

A total of 8,886 patients with AF was included from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry. Patients were categorized according to baseline heart rate, and cardiovascular outcomes were accessed during a median follow-up of 30 months. The primary outcome was a composite of cardiovascular death, hospitalization due to heart failure, and myocardial infarction/critical limb ischemia.

Results

Compared to heart rate ≥100 beats per minute (bpm), heart rate 80-99 bpm was associated with the lowest risk of primary outcome (adjusted hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.40-0.79, p=0.001). In subgroup of patients with heart failure with preserved ejection fraction (HFpEF), heart rate between 80-99 bpm was associated with reduced risk of primary outcome compared to heart rate ≥100 bpm (HR 0.40, 95% CI 0.16-0.98, p=0.045). However, in patients with heart failure with reduced ejection fraction (HFrEF), there was no association between resting heart rate and cardiovascular outcomes (P for interaction 0.001).

Conclusion

Resting heart rate was associated with cardiovascular outcomes in patients with AF, and those with a resting heart rate between 80-99 bpm had the lowest risk of adverse events. The impact of resting heart rate on adverse events persisted in patients with concomitant HFpEF but was not apparent in those with concomitant HFrEF.

Detection of Chlorpyrifos Using Bio-Inspired Silver Nanograss

Chlorpyrifos (CPF) is widely used as an organophosphorus insecticide; however, owing to developmental neurotoxicity, genotoxicity, and other adverse effects, it is harmful not only to livestock but also to humans. Therefore, the use of CPF was recently regulated, and its sensitive detection is crucial, as it causes serious toxicity, even in the case of residual pesticides. Because it is hard to detect the chlorpyrifos directly using spectroscopy (especially in SERS) without chemical reagents, we aimed to develop a SERS platform that could detect the chlorpyrifos directly in the water. In this study, we utilized the intrinsic properties of natural lawns that grow randomly and intertwine with each other to have a large surface area to promote photosynthesis. To detect CPF sensitively, we facilitated the rapid fabrication of biomimetic Ag nanograss (Ag-NG) as a surface-enhanced Raman spectroscopy (SERS) substrate using the electrochemical over-deposition method. The efficiency of the SERS method was confirmed through experiments and finite element method (FEM)-based electromagnetic simulations. In addition, the sensitive detection of CPF was enhanced by pretreatment optimization of the application of the SERS technique (limit of detection: 500 nM). The Ag-NG has potential as a SERS platform that could precisely detect organic compounds, as well as various toxic substances.

Synergistic enhanced rolling circle amplification based on mutS and radical polymerization for single-point mutation DNA detection

The detection of nucleic acids in biofluids is essential for changing the paradigm of disease diagnosis. As there are very few nucleic acids present in human biofluids, a high sensitivity method is required to detect nucleic acids for disease diagnosis. The Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation is associated with non-small cell lung cancer. It is a point mutation and requires a highly selective detection technique. In this study, high sensitivity and selectivity were achieved for the detection of KRAS mutation using rolling circle amplification (RCA), atomic transfer radical polymerization (ATRP), mutS enzyme, and electrochemical sensors. Although RCA can isothermally amplify DNA, it has low selectivity for detecting single-base mismatch DNA, and its sensitivity is not suitable for circulating tumor DNA detection. The selectivity of RCA was improved by using mutS, which can bind specifically to point mutations. In addition, as a method of isothermal radical polymerization, ATRP was used to amplify the weak signal of RCA. Since RCA and ATRP reactions occur simultaneously, detection time was reduced, and the calculated detection limit was 3.09 aM. Computational and experimental analyses were conducted to verify each detection step and the combination of mutS, ATRP, and RCA. The experiment was performed using normal human serum samples for biological application, and the proposed detection method was confirmed to have excellent potential for diagnosing cancer patients.

Temperature influences the content and biosynthesis gene expression of saxitoxins (STXs) in the toxigenic dinoflagellate Alexandrium pacificum

Temperature may affect the production of saxitoxin (STX) and its derivatives (STXs); however, this is still controversial. Further, STX-biosynthesis gene regulation and the relation of its toxicity with temperature are not clearly understood. In the present study, we evaluated the effects of different temperatures (12 °C, 16 °C, and 20 °C) on the growth, toxin profiles, and expression of two core STX-biosynthesis genes, sxtA and sxtG, in the toxic dinoflagellate Alexandrium pacificum Alex05, isolated from Korean coasts. We found that temperature significantly affected cell growth, with maximum growth recorded at 16 °C, followed by 20 °C and 12 °C. HPLC analysis revealed mostly 12 of STXs from the tested cultures. Interestingly, the contents of STXs increased in the cells cultured at 16 °C and exposed to cold stress, compared to the 20 °C culture and heat stress; however, toxin components were much more diverse under heat stress. These toxin profiles generally matched with the sxtA and sxtG expression levels. Incubation at lower temperatures (12 °C and 16 °C) and exposure to cold stress increased sxtA and sxtG expressions in the cells, whereas heat stress showed little change or downregulated the transcription of both genes. Principal component analysis (PCA) showed low correlation between STXs eq and expressional levels of sxtA and sxtG in heat-stressed cells. These results suggest that temperature might be a crucial factor affecting the level and biosynthesis of STXs in marine toxic dinoflagellates.

miR-200c suppression increases tau hyperphosphorylation by targeting 14-3-3γ in early stage of 5xFAD mouse model of Alzheimer's disease

Background and Purpose: Recently, several abnormally regulated microRNAs (miRNAs) have been identified in patients with Alzheimer's disease (AD). The purpose of this study was to identify abnormally expressed miRNAs and to investigate whether they affect pathological changes in AD in the 5xFAD AD mouse model.

Experimental Approach: Using microarray analysis and RT-qPCR, miRNA expression in the hippocampus of a 4-month-old 5xFAD mouse model of AD was investigated. A dual-luciferase assay was performed to determine whether the altered miR-200c regulates the translation of the target mRNA, Ywhag. Whether miR-200c modulates AD pathology was determined in primary hippocampal neurons and C57BL/6J mice transfected with miR-200c inhibitor. In addition, total miRNAs were extracted from the serums of 28 healthy age-matched controls and 22 individual participants with cognitive impairment, and RT-qPCR was performed.

Key results: miR-200c expression was reduced in the hippocampus of 5xFAD mice. In primary hippocampal neurons, miR-200c regulated the translation of 14-3-3γ and increased tau phosphorylation (p-tau) by increasing p-GSK-3β (GSK-3β phosphorylation). It was also confirmed that miR-200c inhibition in the hippocampus of C57BL/6J mice induces cognitive impairment and increases tau phosphorylation through 14-3-3γ activation. Finally, aberrant expression of miR-200c was confirmed in the blood serum of human AD patients.

Conclusion and Implications: Our results strongly suggest that dysregulation of miR-200c expression contributes to the pathogenesis of AD, including cognitive impairment through hyperphosphorylated tau.

Measurement of Differential Branching Fractions of Inclusive B→X_{u}ℓ^{+}ν_{ℓ} Decays

The first measurements of differential branching fractions of inclusive semileptonic B→X_{u}ℓ^{+}ν_{ℓ} decays are performed using the full Belle data set of 711  fb^{-1} of integrated luminosity at the ϒ(4S) resonance and for ℓ=e, μ. With the availability of these measurements, new avenues for future shape-function model-independent determinations of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| can be pursued to gain new insights in the existing tension with respect to exclusive determinations. The differential branching fractions are reported as a function of the lepton energy, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic B→X_{c}ℓ^{+}ν_{ℓ} decays and other processes, and corrected for resolution and acceptance effects.

Precise Measurement of the D^{0} and D^{+} Lifetimes at Belle II

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72  fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst)  fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst)  fs, are the most precise to date and are consistent with previous determinations.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

Mesoscale Frank-Kasper Crystal Structures from Dendron Assembly by Controlling Core Apex Interactions

Single-component polymeric materials open up a great potential for self-assembly into mesoscale complex crystal structures that are known as Frank-Kasper (FK) phases. Predicting the packing structures of the soft-matter spheres, however, remains a challenge even when the molecular design is precisely known. Here, we investigate the role of the molecules' enthalpic interaction in determining the low-symmetry crystal structures. To this end, we synthesize architecturally asymmetric dendrons by varying their apex functionalities and examine the packing structures of the second-generation (G2) dendritic wedges. Our work shows that weakening the hydrogen bonding of the dendron apex makes the particles softer and smaller, and leads to the formation of various FK structures at lower temperatures, including the new observation of a FK C14 phase in the cone-shaped dendron systems. As a consequence of the free energy balance between the particle's interfacial tension and the chain's stretching, various packing structures are mainly tuned by designing the hydrogen bonding interaction.

Salinity Affects Saxitoxins (STXs) Toxicity in the Dinoflagellate Alexandrium pacificum, with Low Transcription of SXT-Biosynthesis Genes sxtA4 and sxtG

Salinity is an important factor for regulating metabolic processes in aquatic organisms; however, its effects on toxicity and STX biosynthesis gene responses in dinoflagellates require further elucidation. Herein, we evaluated the physiological responses, toxin production, and expression levels of two STX synthesis core genes, sxtA4 and sxtG, in the dinoflagellate Alexandrium pacificum Alex05 under different salinities (20, 25, 30, 35, and 40 psu). Optimal growth was observed at 30 psu (0.12 cell division/d), but cell growth significantly decreased at 20 psu and was irregular at 25 and 40 psu. The cell size increased at lower salinities, with the highest size of 31.5 µm at 20 psu. STXs eq was highest (35.8 fmol/cell) in the exponential phase at 30 psu. GTX4 and C2 were predominant at that time but were replaced by GTX1 and NeoSTX in the stationary phase. However, sxtA4 and sxtG mRNAs were induced, and their patterns were similar in all tested conditions. PCA showed that gene transcriptional levels were not correlated with toxin contents and salinity. These results suggest that A. pacificum may produce the highest amount of toxins at optimal salinity, but sxtA4 and sxtG may be only minimally affected by salinity, even under high salinity stress.