bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of continuous inhaled corticosteroids on glycated hemoglobin in asthmatic children: a pilot study
Authors: Fawzy Erini Farid , Attar Mona Mohsen El , Badry Mahmoud Ahmed El , Al Khashab Khaled Mohammed
Published: October 2024

Background

Asthma is a prevalent chronic disease with significant impact on patients, families, and communities. Inhaled corticosteroids (ICS) are the mainstay of treatment for persistent and uncontrolled asthma. However, concerns remain about the potential adverse effects of ICS, including HbA1c level. This study aims to evaluate the influence of ICS on Hemoglobin A1c (HbA1c) levels in children with bronchial asthma.

Methods

This prospective cohort study included 48 pediatric asthma patients aged 2 to 15 years who had been using ICS for at least 6 months. Comprehensive clinical assessments and measurements of HbA1c levels were conducted at the start of recruitment and after 6 months of ICS use. The types and doses of ICS used followed the guidelines provided by the Global Initiative for Asthma (GINA).

Results

The initial HbA1c levels ranged from 4.46 to 6.11, with a mean of 5.32 ± 0.35. Three patients (6.3%) had persistent prediabetes status after 6 months. There was no significant relationship between glycemic status and the characteristics of ICS. The duration of ICS therapy and the doses used did not significantly affect HbA1c levels. A weak positive correlation was observed between initial and subsequent HbA1c levels.

Conclusion

The study found no significant difference in HbA1c levels among asthmatic children using ICS after six months of treatment. Additionally, there was no significant difference in HbA1c levels between patients using different types of ICS. Regular monitoring of HbA1c levels is recommended, particularly for children on high doses or prolonged use of inhaled Fluticasone.
Resistant inflammatory breast lesions: can AI exclude malignancy?
Authors: El-nasr Safaa Ibrahim Saif , ElSayed Norhan Mohamed Samy , Badawy Eman , Taha Sherif Nasser , Hegazy Rania Mohamed A.
Published: October 2024

Background

Numerous underlying causes can lead to inflammatory breast disorders. A wide range of non-specific symptoms may be presenting symptoms, which could cause a delay in diagnosis and thus improper therapy. Studies on artificial intelligence (AI) are rapidly developing and offer a wide range of possible uses in breast imaging. Artificial intelligence-based computer-assisted diagnosis (AI-CAD) holds promise in the field of mammography. It demonstrated diagnostic performances that are equivalent to or even better than those achieved by stand-alone methods. The current work aimed to identify whether AI can improve the performance of mammography in diagnosing inflammatory breast diseases and excluding the underlying malignancy in cases resistant to treatment that may reduce the need for interventional procedures such as biopsy.

Methods

Our study was a retrograde one done on 34 patients with pathologically proven inflammatory breast lesions.

Results

Suppurative breast lesions gave high false positive results. This was also the case with granulomatous mastitis; while simple inflammatory lesions gave true negative results on AI interrogation.

Conclusions

Artificial intelligence can be of great value in diagnosing simple inflammatory breast lesions thus following up on such lesions can usually be sufficient without asking for unneeded biopsies. On the other hand, our study showed that AI had high false positive results in suppurative lesions and granulomatous mastitis. Consequently, ultrasonography can be more reliable in their diagnosis.
Lowering the burden: Shorter versions of the Program Sustainability Assessment Tool (PSAT) and Clinical Sustainability Assessment Tool (CSAT)
Authors: Malone Sara , Prewitt Kim , McKay Virginia , Zabotka Luke , Bacon Caren , Luke Douglas A.
Published: October 2024

Background

Although significant advances have been made in the conceptualization of sustainability, having pragmatic, psychometrically valid tools remains a need within the field. Our previous work has developed frameworks and tools to assess both program sustainability and clinical sustainability capacity. This work presents new, psychometrically tested short versions of the Program Sustainability Assessment Tool (PSAT) and the Clinical Sustainability Assessment Tool (CSAT).

Methods

These methods were conducted in identical, parallel processes for the CSAT and PSAT. Previously collected data for these instruments was obtained across a variety of settings, contexts, and participants. We first conducted testing to determine cronbach’s alpha of shortened domains (3 items each) and then conducted Confirmatory Factor Analysis to ensure that the domains were still appropriate for the tool. After, the team met to review the results and determine the final versions of the short PSAT and short CSAT.

Results

The short PSAT retained cronbach’s alpha’s of 0.82 – 0.91 for each domain of the tool, with which maintains excellent reliability for the tool. Confirmatory factor analysis highlights that the short PSAT retains conceptual distinction across the 8 domains, with CFI scores greater than 0.90, RMSEA scores below 0.6, and SRMR scores less than 0.08. The short CSAT had cronbach’s alpha of 0.84 – 0.92 for each of the domains of the tool, also suggesting excellent reliability of the domains within the measure after dropping two items/domain. Confirmatory factor analysis of the short CSAT meets the same specifications as above, again highlighting conceptual distinction across the domains.

Conclusion

Each tool was able to be shortened to three items per domain while maintaining strong psychometric properties. This results in a tool that takes less time to complete, meeting one of the key calls for pragmatic measures within implementation science. This advances our abilities to measure and test sustainability within implementation science.
Interdisciplinary advances in microcombs: bridging physics and information technology
Authors: Yao Bai-Cheng , Wang Wen-Ting , Xie Zhen-Da , Zhou Qiang , Tan Teng , Zhou Heng , Guo Guang-Can , Zhu Shi-Ning , Zhu Ning-Hua , Wong Chee Wei
Published: October 2024

The advancement of microcomb sources, which serve as a versatile and powerful platform for various time–frequency measurements, have spurred widespread interest across disciplines. Their uses span coherent optical and microwave communications, atomic clocks, high-precision LiDARs, spectrometers, and frequency synthesizers. Recent breakthroughs in fabricating optical micro-cavities, along with the excitation and control of microcombs, have broadened their applications, bridging the gap between physical exploration and practical engineering systems. These developments pave the way for pioneering approaches in both classical and quantum information sciences. In this review article, we conduct a thorough examination of the latest strategies related to microcombs, their enhancement and functionalization schemes, and cutting-edge applications that cover signal generation, data transmission, quantum analysis, and information gathering, processing and computation. Additionally, we provide in-depth evaluations of microcomb-based methodologies tailored for a variety of applications. To conclude, we consider the current state of research and suggest a prospective roadmap that could transition microcomb technology from laboratory settings to broader real-world applications.
Efficient microresonator frequency combs
Authors: Yang Qi-Fan , Hu Yaowen , Torres-Company Victor , Vahala Kerry
Published: October 2024

The rapid development of optical frequency combs from their table-top origins towards chip-scale platforms has opened up exciting possibilities for comb functionalities outside laboratories. Enhanced nonlinear processes in microresonators have emerged as a mainstream comb-generating mechanism with compelling advantages in size, weight, and power consumption. The established understanding of gain and loss in nonlinear microresonators, along with recently developed ultralow-loss nonlinear photonic circuitry, has boosted the optical energy conversion efficiency of microresonator frequency comb (microcomb) devices from below a few percent to above 50%. This review summarizes the latest advances in novel photonic devices and pumping strategies that contribute to these milestones of microcomb efficiency. The resulting benefits for high-performance integration of comb applications are also discussed before summarizing the remaining challenges.
Second-Generation Supraglottic Airway Devices Versus Endotracheal Intubation in Adults Undergoing Abdominopelvic Surgery: A Systematic Review and Meta-Analysis
Authors: de Carvalho Clístenes Crístian , Kapsokalyvas Ioannis , El-Boghdadly Kariem
Published: October 2024

BACKGROUND:

Second-generation supraglottic airway (SGA) devices are widely used, but thought to have inferior safety performance to endotracheal tubes (ETTs), but might be equally efficacious while improving patient-centered outcomes. We compared second-generation SGAs with ETTs for perioperative safety, efficacy, and quality of recovery in adults undergoing abdominopelvic surgery under general anesthesia. Our primary objective was to assess safety in the form of major airway complications. Secondary objectives were other safety, efficacy, and quality of recovery outcomes.

METHODS:

We searched 4 databases for randomized controlled trials of adult patients having abdominopelvic surgery comparing second-generation SGAs and ETTs. After 2-person screening and data extraction, pairwise meta-analysis was conducted and the grading of recommendations, assessment, development, and evaluation (GRADE) approach was applied to assess the certainty of evidence.

RESULTS:

A total of 51 studies, randomizing 5110 patients, were included. Second-generation SGAs significantly reduced the risk of major perioperative airway complications (risk ratio [RR], 0.41; 95% confidence interval [CI], 0.23–0.71; P = .007; low certainty), with no clear clinically relevant difference in regurgitation or pulmonary aspiration (low certainty). SGAs significantly increased the risk of inadequate ventilation (RR, 3.36; 95% CI, 1.43–7.89; P = .011; very low certainty); however, postoperative sore throat (RR, 0.52; 95% CI, 0.38–0.70; P < .001; moderate certainty), hoarseness (RR, 0.32; 95% CI, 0.231–0.48; P < .001; low certainty), coughing at the emergence of anesthesia (RR, 0.17; 95% CI, 0.08–0.36; P < .001; low certainty), and postoperative nausea and vomiting (RR, 0.64; 95% CI, 0.42–0.98; P = .042; very low certainty) were all less frequent with SGAs. No other clinically relevant differences were observed for other remaining outcomes.

CONCLUSIONS:

Second-generation SGAs reduce the risk of major airway complications compared with ETTs in adults undergoing abdominopelvic procedures under general anesthesia, with no reported clinically relevant differences in the risk of regurgitation or pulmonary aspiration. Additionally, they improve the quality of postoperative recovery with lower risk of sore throat, hoarseness, and postoperative nausea and vomiting. These data provide an opportunity for clinicians to reassess the implications of conservative airway management, and potentially expand the role of second-generation SGAs in routine clinical practice.
Characterization of alternative splicing during mammalian brain development reveals the extent of isoform diversity and potential effects on protein structural changes
Authors: Haj Abdullah Alieh Leila , Cardoso de Toledo Beatriz , Hadarovich Anna , Toth-Petroczy Agnes , Calegari Federico
Published: October 2024

Regulation of gene expression is critical for fate commitment of stem and progenitor cells during tissue formation. In the context of mammalian brain development, a plethora of studies have described how changes in the expression of individual genes characterize cell types across ontogeny and phylogeny. However, little attention has been paid to the fact that different transcripts can arise from any given gene through alternative splicing (AS). Considered a key mechanism expanding transcriptome diversity during evolution, assessing the full potential of AS on isoform diversity and protein function has been notoriously difficult. Here, we capitalize on the use of a validated reporter mouse line to isolate neural stem cells, neurogenic progenitors and neurons during corticogenesis and combine the use of short- and long-read sequencing to reconstruct the full transcriptome diversity characterizing neurogenic commitment. Extending available transcriptional profiles of the mammalian brain by nearly 50,000 new isoforms, we found that neurogenic commitment is characterized by a progressive increase in exon inclusion resulting in the profound remodeling of the transcriptional profile of specific cortical cell types. Most importantly, we computationally infer the biological significance of AS on protein structure by using AlphaFold2, revealing how radical protein conformational changes can arise from subtle changes in isoforms sequence. Together, our study reveals that AS has a greater potential to impact protein diversity and function than previously thought, independently from changes in gene expression.
Differentiation of CD166-positive hPSC-derived lung progenitors into airway epithelial cells
Authors: Goh Kim Jee , Lu Hao , Tan Ee Kim , Lee Zhao Yong , Wong Amanda , Tran Thai , Dunn N. Ray , Roy Sudipto
Published: October 2024

The generation of lung epithelial cells through the directed differentiation of human pluripotent stem cells (hPSCs) in vitro provides a platform to model both embryonic lung development and adult airway disease. Here, we describe a robust differentiation protocol that closely recapitulates human embryonic lung development. Differentiating cells progress through obligate intermediate stages, beginning with definitive endoderm formation and then patterning into anterior foregut endoderm that yields lung progenitors (LPs) with extended culture. These LPs can be purified using the cell surface marker CD166 (also known as ALCAM), and further matured into proximal airway epithelial cells including basal cells, secretory cells and multiciliated cells using either an organoid platform or culture at the air-liquid interface (ALI). We additionally demonstrate that these hPSC-derived airway epithelial cells can be used to model Influenza A infection. Collectively, our results underscore the utility of CD166 expression for the efficient enrichment of LPs from heterogenous differentiation cultures and the ability of these isolated cells to mature into more specialized, physiologically relevant proximal lung cell types.
Spatial arrangement of the whiskers of harbor seals (Phoca vitulina) compared with whisker arrangements of house mice (Mus musculus) and brown rats (Rattus norvegicus)
Authors: Graff Matthew M. , Belli Hayley M. , Wieskotten Sven , Bresee Chris S. , Krüger Yvonne , Janssen Thomas L. , Dehnhardt Guido , Hartmann Mitra J. Z.
Published: October 2024

Whiskers (vibrissae) are important tactile sensors for most mammals. We introduce a novel approach to quantitatively compare 3D geometry of whisker arrays across species with different whisker numbers and arrangements, focusing on harbor seals (Phoca vitulina), house mice (Mus musculus) and Norway rats (Rattus norvegicus). Whiskers of all three species decrease in arclength and increase in curvature from caudal to rostral. They emerge from the face with elevation angles that vary linearly with dorsoventral position, and with curvature orientations that vary diagonally as linear combinations of dorsoventral and rostrocaudal positions. In seals, this diagonal varies linearly with horizontal emergence angles, and is orthogonal to the diagonal for rats and mice. This work provides the first evidence for common elements of whisker arrangements across species in different mammalian orders. Placing the whisker array model on a CAD model of a seal head enables future mechanical studies of whisker-based sensing, including wake tracking.
Conserved role for spliceosomal component PRPF40A in microexon splicing
Authors: Choudhary Bikash , Norris Adam
Published: October 2024

Microexons (exons ≤30 nt) are important features of neuronal transcriptomes, but pose mechanistic challenges to the splicing machinery. We previously showed that PRP-40, a component of the U1 spliceosome, is globally required for microexon splicing inCaenorhabditis elegans. Here we show that the homologous PRPF40A is also globally required for microexon splicing in mouse neuroblastoma cells. We find that PRPF40A coregulates microexons along with SRRM4, a neuron-specific regulator of microexon splicing. The relationship between exon size and dependence on PRPF40A/SRRM4 is distinct, with SRRM4-dependence exhibiting a size threshold (∼30 nt) and PRPF40A-dependence exhibiting a graded decrease as exon size increases. Finally, we show that PRPF40A knockdown causes an increase in productive splicing of its spliceosomal binding partnerLuc7lby the skipping of a small “poison exon.” Similar homeostatic cross-regulation is often observed across paralogous RNA-binding proteins. Here we find this concept likewise applies across evolutionarily unrelated but functionally and physically coupled spliceosomal components.
Life should be redefined: Any molecule with the ability to self-replicate should be considered life
Authors: Liu Zheng
Published: October 2024

Understanding the nature of life and its propensity for reproduction has long been a question that humans aspire to answer. Reproduction, a defining characteristic of life, fundamentally involves the replication of genetic material, be it DNA or RNA. The driving force behind this replication process has always intrigued scientists. In recent years, theories involving selfish genes, the RNA world, and entropic forces have been proposed by some scholars. These theories seem to suggest that life, as we know it, exists solely in Earth’s environment and is based on a single type of genetic material, either DNA or RNA. However, if we broaden our definition of life to include any replicable molecules, we might be able to transcend traditional thought. This could potentially enhance our understanding of the impetus behind DNA replication and provide deeper insights into the essence of life.
Re-conceptualization of the learning environment as a dynamic system
Authors: Ito Hideaki
Published: October 2024

In Japanese language education, the term "learning environment" is used in various contexts. This paper investigates the term "learning environment" in previous studies and notes that traditional learning environments have been characterized as "morphological characteristics learning environments" focusing on static learners. However, since learning environments involve a dynamic, reciprocal relationship where learners and their surroundings interact and evolve, the paper advocates for a re-conceptualization of "experiential-ecological learning environments" that captures this dynamic nature. Furthermore, to enrich the experiential-ecological learning environment for learners, the presence of learning environment engineers and the meaningful valuing of environmental enrichments is essential. Lastly, the paper emphasizes that by combining various individual learning experiences, it is possible to create a sustainable and richer learning environment.
Use of the patient-centered outcome Days Alive and Out of Hospital in clinical studies on perioperative care: a scoping review protocol
Authors: Meza Nicolas , Bracchiglione Javier , Madrid Eva , Escobar Liquitay Camila Micaela , Popova Ekaterine , Salazar Rolando , Urrútia Gerard
Published: October 2024

Background Various studies across different settings have validated Days Alive and Out of Hospital (DAOH) as a valuable outcome for clinical research in surgery and other fields. However, there is no clear consensus on the definitions and methods used to handle and report DAOH in perioperative care studies. Objective We aim to identify, describe, and summarize the available research on DAOH to understand how it is being conceptualized and utilized in clinical studies on perioperative care. Methods We will conduct a scoping review to analyze and synthesize the existing studies using DAOH to measure clinical results on perioperative care. We will search MEDLINE, Embase, Web of Science, ClinicalTrials.gov and CENTRAL. Screening, eligibility, inclusion and data extraction processes will be performed by two reviewers, with a third reviewer solving disagreements. We will present our results descriptively. Conclusions We expect to provide a comprehensive overview of how DAOH is conceptualized and utilized in clinical studies on perioperative care, with particular attention to methodological approaches and the role of electronic health-care records (EHRs) among the different regions.
Theory, Search, and Learning
Authors: Sorenson Olav
Published: October 2024

When searching for a solution to a problem, having a theory—an underlying causal structure that explains outcomes as a consequence of antecedents and that allows for the prediction of potential consequences of combinations of choices not yet tried—changes the way in which people explore the solution space. Whether a theory proves useful to search, however, depends not just on its predictive precision. This essay argues that the internal structures of theories—their size, complexity, the extent of their elaboration, and the confidence that their users have in the assumptions—also influences how people search for solutions and the efficiency of their search processes. It offers several conjectures about how theory and theory structure influence search and about which types of theories prove most useful to success.
Some Interfacial Interactions between Isocyanates and Metals that Affect Release in Composite Wood-Panel Production*
Authors: Phanopoulos Christopher , Holvoet Servaas , Pratelli Daniele , Pans Griet , Shimizu Kyoko , Ng Simon , Bañuls-Ciscar Jorge , Abel Marie-Laure , Watts John F.
Published: October 2024

Isocyanate- and polyurethane-based adhesives for composite wood-panel production are well known. They are useful for the manufacture of high-performance assemblies, particularly for moisture resistance, durability, and strength. However, isocyanate-based adhesives have several opportunities for improvements related to composite panel manufacture. Of particular note is the ability of isocyanates to bond, not only to wood, but to metal press platens used to produce the composite panels. Although several methodologies exist to overcome this, there is a lack of understanding of the nature of the interactions between isocyanates and metal. The purpose of the current study was to provide insights into these interactions and to help to develop strategies for releasable isocyanate-based resins.

Variable-thickness isocyanate–metal and metal–wood assemblies were prepared and the interface exposed by various methods, e.g., surface analysis combined with cluster beam etching and simple peel tests. The interfaces were then analyzed by X-ray photoelectron spectroscopy or time-of-flight–secondary ion mass spectrometry (or both). These surface analytical methods have revealed several chemical interactions between the isocyanates and the metal surfaces, including carbamate-type links and metal–nitrogen linkages. Further, the surface analysis has revealed the compositional character of the locus of failure in wood–metal joints. The locus of failure depends on the presence of wood extractives. With nonextracted wood, the locus of failure is within the wood, which is characterized by a certain concentration of the penetrated resin. With solvent-extracted wood, the locus of failure is within the glue line.
High-definition quadriwave lateral shearing interferometry
Authors: Wattellier Benoit , Saintoyant Anaïs , Savatier Julien , de Laulanie Lucie , Aknoun Sherazade , Zinchuk Roman , Monneret Serge
Published: October 2024

We present an evolution of quadriwave lateral shearing interferometry that improves the definition of quantitative phase images. It is now possible to produce images with as many pixels as the camera that records the interferogram. This is done by moving a diffraction grating in front of the camera and linearly combining at least nine acquisitions. In this paper, we present the principle of this technique and illustrate it by several examples acquired on a microscope with both calibrated and biological samples. We demonstrate the possibility of producing quantitative phase images with 5.5 million pixels, which are to our knowledge the largest images ever produced by a wavefront sensor.
Federated learning-based wavelength demodulation system for multi-point distributed multi-peak FBG sensors
Authors: Hou Xuan , Ren Sufen , Yu Kebei , Hu Yule , Xu Haoyang , Xue Chenyang , Chen Shengchao , Wang Guanjun
Published: October 2024

Machine learning-based demodulation of multi-peak fiber Bragg grating (FBG) sensors has been extensively studied, demonstrating superior performance compared to conventional algorithms because it can neglect potential physical constraints. As the number of real-world monitoring points increases, the volume of fiber-optic sensing data grows exponentially. This necessitates aggregating data from various regions (e.g., via Wi-Fi), unlike traditional single-point monitoring, which challenges server storage capacity and communication efficiency. To address these issues, this paper proposes a federated learning (FL)-based framework for efficient wavelength demodulation of multi-peak FBGs in multipoint monitoring. Specifically, an arrayed waveguide grating (AWG) with multiplexing capability is employed at different monitoring points to convert spectral features into multi-channel transmission intensities, serving as training data for local models. Subsequently, the local model parameters, trained independently at each point, are uploaded to a central server to derive the optimal global model for demodulation across different monitoring points. The proposed demodulation framework is validated through stress demodulation experiments on multi-peak FBG sensors. Experimental results indicate strong multi-peak extraction performance with a demodulation error of ±0.64 pm. Additionally, the method demonstrates excellent applicability for generating high-precision global demodulation models through multi-node cooperative work under various scenarios.
Real-time holographic 3D display using Split–Lohmann Fresnel computer-generated hologram (SL-FCGH)
Authors: Ding Xian , Chang Chenliang , Dai Bo , Wang Qi , Zhang Dawei , Zhuang Songlin
Published: October 2024

Real-time generation of computer-generated hologram (CGH) from three-dimensional (3D) objects has been a long-standing problem in holographic display. In this paper we report a fast CGH generation algorithm, which can rapidly synthesize a 3D Fresnel hologram in only one-step backward propagation calculation in a Split–Lohmann lens-based diffraction model. In such a calculation scheme, we utilize an image padding and cropping strategy to remove image artifacts and improve the display quality in a large depth range. The generated hologram, which is called Split–Lohmann Fresnel CGH (SL-FCGH), can reproduce 3D images through free-space Fresnel diffraction optics. The computation time of the proposed method is independent of the quantized layer numbers and, therefore, can achieve real-time computation speed with a very dense depth sampling. Both simulation and experimental results of full-color holographic display prove the validation of the proposed method.
Turnkey generation of MIR soliton and NIR second-harmonic microcombs
Authors: Shi Lei , Ming Xianshun , Yu Hengshen , Ma Kai , Sun Qibing , Wang Leiran , Zhao Wei , Zhang Wenfu
Published: October 2024

Mid-infrared (MIR) microcombs exhibit remarkable advantages for trace molecule detection, facilitating fast and precise spectral analysis. However, due to limitations in tunability and size of available MIR pump sources, it is difficult to achieve compact MIR mode-locked microcombs using traditional methods. Here, we propose the turnkey generation of MIR soliton and near-infrared second-harmonic microcombs in a single microresonator. The self-starting method based on self-injection locking eliminates the complex tuning process and is compatible with modular packaged MIR distributed-feedback lasers. By simultaneously leveraging second- and third-order nonlinearities, frequency up-conversion can be achieved without relying on external nonlinear media, facilitating the integration of f-2f self-referencing. Additionally, the direct turnkey generation of breathing solitons and two-soliton states has been achieved. Meanwhile, a new method is proposed that allows for quickly switching between different soliton states by simply changing the pump power. We provide operational guidelines and explain its operating mechanism. Dynamical analysis shows that the detuning automatically converges to the red detuning region corresponding to the target soliton state. Our work provides a full-system miniaturized mode-locking scheme for MIR microcombs and offers new potential for fast switching of soliton states and self-referencing of single-resonator.
Conformal holography with curved light sheets
Authors: Angelis Vinicius S. , Dorrah Ahmed H. , Ambrosio Leonardo A. , Capasso Federico
Published: October 2024

Projecting images onto arbitrary curved surfaces is a sought-after goal in computer-generated holography applications. However, achieving high axial resolution with a low level of cross-talk using a single computer-generated hologram is still challenging. Here we propose and demonstrate a new type of holographic technique that projects conformal images onto two-dimensional arbitrarily shaped curved sheets oriented perpendicular to the display. These curved sheets are constructed from an array of non-diffracting light threads, each one with its intensity controlled by a superposition of Bessel beams, providing us with a continuous depth along the optical path. Our holograms present good reconstruction quality, opening new applications in laser beam shaping and light-matter interaction.
Research on a signal demodulation algorithm for fiber optic acoustic sensors based on the amplitude ratio of harmonic components
Authors: Qiu Zongjia , Zhang Guoqiang , Zhang Meng , Guo Shaopeng , Li Qun , Shao Jian , Wu Peng
Published: October 2024

Fiber optic sensing technology's performance is crucially influenced by the choice of demodulation algorithms. Traditional intensity demodulation methods rely on precisely controlling the working point to the quadrature point (Q point) by adjusting the laser wavelength. However, issues like laser wavelength adjustment accuracy and laser power variations with wavelength affect demodulation accuracy, limiting its application in complex scenarios. Additionally, this method requires sensitivity calibration and has a limited dynamic range. To address these limitations, this paper proposes an amplitude ratio of harmonic components (ARHC) demodulation algorithm. It analyzes the harmonic components of the interference light intensity output by the sensor to calculate Fabry-Perot cavity length changes, achieving real-time demodulation of dynamic signals. Compared to traditional methods, the ARHC algorithm simplifies system adjustment, has a larger demodulation range and higher accuracy, and is more adaptable to environmental changes. Simulations and experiments demonstrate its effectiveness and high-precision, large-dynamic-range signal demodulation capabilities under different interference conditions. The EFPI ultrasonic sensitivity based on the ARHC algorithm is 2.5 nm/Pa@23kHz, and it can linearly demodulate up to a vibration amplitude of 372.8 nm for the sensitive diaphragm, with a demodulation error of less than or equal to 0.8 nm.
Metrology-grade spectroscopy source based on an optical parametric oscillator
Authors: Schenkel M. R. , Vogt V. A. , Schiller S.
Published: October 2024

Continuous-wave optical parametric oscillators (OPOs) are widely tunable and powerful sources of narrow-linewidth radiation. These properties make them suitable for a wide range of spectroscopic studies - but so far not at the metrological level. Indeed, although important technical OPO developments occurred more than two decades ago, and commercial devices have been available for nearly as long, the long-hoped-for the potential of these devices, providing simultaneously ultralow linewidth, ultrahigh frequency stability, ultrahigh frequency accuracy, and wide wavelength coverage has not yet become a reality. Here, we present an OPO metrology system suitable for optical spectroscopy with ultra-high resolution and accuracy in the 2.2 - 3.9 μm range. The system relies on the second-harmonic generation of the idler wave to bridge the gap to the near-infrared regime where frequency combs are readily available. By actively controlling the pump laser frequency, the idler radiation is phase-locked to an optically stabilized frequency comb, enabling a full transfer of the frequency comb’s spectral properties to the idler radiation and measuring the idler frequency with ultra-high precision. We reach fractional line widths and Allan deviations of the idler radiation at the level of 4 × 10−14 and 1 × 10−14, respectively. We also perform a thorough characterization of the stabilized OPO via a comparison with a second, independent optically stabilized frequency comb and thereby determine an overall idler frequency systematic uncertainty of less than 1.2 × 10−14. Sources of residual frequency noise are identified. The system delivered excellent results in high-accuracy spectroscopy.
Reconstructing Richtmyer–Meshkov instabilities from noisy radiographs using low dimensional features and attention-based neural networks
Authors: Serino Daniel A. , Klasky Marc L. , Nadiga Balasubramanya T. , Xu Xiaojian , Wilcox Trevor
Published: October 2024

We develop an ML-based approach for density reconstruction based on transformer neural networks. This approach is demonstrated in the setting of ICF-like double shell hydrodynamic simulations wherein the parameters related to material properties and initial conditions are varied. The new method can robustly recover the complex topologies given by the Richtmyer-Meshkoff instability (RMI) from a sequence of hydrodynamic features derived from radiographic images corrupted with blur, scatter, and noise. A noise model is developed to characterize errors in extracting features from synthetic radiographs of the simulated density field. The key component of the network is a transformer encoder that acts on a sequence of features extracted from noisy radiographs. This encoder includes numerous self-attention layers that act to learn temporal dependencies in the input sequences and increase the expressiveness of the model. This approach is shown to exhibit an excellent ability to accurately recover the RMI growth rates, despite the gas-metal interface being greatly obscured by radiographic noise. Our approach can be applied in a broad array of fields involving shock physics and material science.
Tailoring femtosecond LSP resonance and lifetime in a nanoresonator via phase retardation
Authors: Qin Yulu , Hu Hanmin , Cheng Haoyang , Zhou Xiaolong
Published: October 2024

The manipulation of femtosecond plasmon resonance and lifetime in a nanoantenna is crucial for the realization of integrated and miniaturized plasmonic circuits. Here, we have used FDTD simulations to study the plasmonic resonance and lifetime variation of the far-end (PA) and near-end (PB) hotspots of size-gradient nanoresonators. We found that the near-field spectrum of PA is red-shifted compared to PB due to the phase retardation effect. By capturing the ultrafast dynamics of both hotspots, we confirm that these phenomena are governed by the transient evolution of the plasmonic field in the forced oscillation regime. Furthermore, the lifetimes of plasmonic hotspots scale directly with their near-field intensities. Meanwhile, the lifetime τA is always larger than that of τB in the same nanoresonator because of the smaller non-radiative damping of hotspot PA. Our results provide a basis for the miniaturization of plasmonic nanoresonators.
Omnidirectional path loss model for non-line-of-sight ultraviolet communications
Authors: Luo Tian , Zuo Yong , Li Feiyu , Du Zhihua , Song Xiaohan , Wang Yuhao , Hong Xiaobin , Wu Jian
Published: October 2024

To analyze the channel characteristics in omnidirectional reception scenarios for non-line-of-sight ultraviolet (UV) communication, we derive expressions for the reception direction distribution based on the incident photons at the receiver and propose an omnidirectional reception path loss (PL) channel model based on the Monte Carlo (MC) method. Furthermore, we validate the proposed omnidirectional model by comparing it with the existing MC numerical model that traverses all reception directions. Results indicate that the average computation time of the proposed omnidirectional PL model is less than 0.03% of the traversal model while maintaining comparable accuracy. Additionally, we present the variations in off-axis and inclination angles corresponding to the receiver’s direction at different coordinate positions. Therefore, this paper provides valuable guidance for rapidly determining the omnidirectional energy field distribution and optimizing receiver orientation in UV communication systems.
Optimization of a large aperture wedge prism support system based on the closed-loop structural-thermal-optical performance method
Authors: Wen Wansha , Ruan Ping , Li Baopeng , Lv Tao
Published: October 2024

In the instrument suite of the Thirty Meter Telescope (TMT), the linear atmospheric dispersion corrector (LADC) is positioned at the forefront of the spectrometer to mitigate atmospheric dispersion. The LADC comprises two large aperture wedge prisms, each approximately 1.5 meters in diameter. These prisms, which are transmissive optical elements, are supported radially along their outer circumferences. However, due to the rotational asymmetry of the prisms relative to the optical axis, the support forces do not align with the plane of the center of gravity, leading to a bending moment caused by gravitational and reaction forces. This misalignment results in significant deformation of the prism surfaces. The structural-thermal-optical performance integrated model method is typically employed to evaluate the impact of the support system on prism surface deformation. This process often involves extensive manual iterations and operates in an open-loop manner, making it inefficient and heavily reliant on the analyst’s expertise. To address these limitations, this paper proposes a closed-loop integrated model analysis optimization method aimed at enhancing optimization efficiency. By integrating interface programs between analysis tools and applying advanced optimization algorithms, the traditional open-loop integrated model analysis process is transformed into a closed-loop system, enabling more efficient and reliable optimization. The closed-loop integrated model method incorporates Optimal Latin Hypercube Design (Opt LHD) and Particle Swarm Optimization (PSO) algorithms to optimize the prism support structure, reducing the analysis time from one week to just two days. Compared to the original support structure, the root mean square (RMS) value of optical surface deformation decreased by 49.3%, from 155.0 nm to 78.6 nm, under gravity and 2°C temperature coupled conditions; and by 62.5%, from 289. 1 nm to 108. 4 nm, under gravity and 42°C temperature coupled conditions. These results demonstrate that the closed-loop integrated model optimization method not only improves efficiency but also achieves significantly better outcomes.
Strain-concentration for fast, compact photonic modulation and non-volatile memory
Authors: Wen Y. Henry , Heim David , Zimmermann Matthew , Shugayev Roman A. , Dong Mark , Leenheer Andrew J. , Gilbert Gerald , Heuck Mikkel , Eichenfield Matt , Englund Dirk R.
Published: October 2024

A critical figure of merit (FoM) for electro-optic (EO) modulators is the transmission change per voltage, dT/dV. Conventional approaches in wave-guided modulators maximize dT/dV via a high EO coefficient or longer light-material interaction lengths but are ultimately limited by material losses and nonlinearities. Optical and RF resonances improve dT/dV at the cost of spectral non-uniformity, especially for high-Q optical cavity resonances. Here, we introduce an EO modulator based on piezo-strain-concentration of a photonic crystal cavity to address both trade-offs: (i) it eliminates the trade-off between dT/dV and waveguide loss—i.e., enhancement of the resonance tuning efficiency dv
c
/dV for the fixed EO coefficient, waveguide length, and cavity Q—and (ii) at high DC strains it exhibits a non-volatile (NV) cavity tuning Δvc,NV for passive memory and programming of multiple devices into resonance despite fabrication variations. The device is fabricated on a scalable silicon nitride-on-aluminum nitride platform. We measure dv
c
/dV=177±1MHz/V, corresponding to Δv
c
=40±0.32GHz for a voltage spanning ±120V with an energy consumption of δU/Δv
c
=0.17nW/GHz. The modulation bandwidth is flat up to ωBW,3dB/2π=3.2±0.07MHz for broadband DC-AC and 142±17MHz for resonant operation near a 2.8 GHz mechanical resonance. Optical extinction up to 25 dB is obtained via Fano-type interference. Strain-induced beam-buckling modes are programmable under a “read-write” protocol with a continuous, repeatable tuning range of 5±0.25GHz, allowing for storage and retrieval, which we quantify with mutual information of 2.4 bits and a maximum non-volatile excursion of 8 GHz. Using a full piezo-optical finite-element-model (FEM) we identify key design principles for optimizing strain-based modulators and chart a path towards achieving performance comparable to lithium niobate-based modulators and the study of high strain physics on-chip.
Geometrical predictions of focus-based passive ranging via image-displaced mean absolute Fourier transform
Authors: Tran Phillip , Iorga Michael , Parrish Todd
Published: October 2024

Using geometrical optics, the authors predict the mean absolute Fourier transform (MAFT) as a novel method of focus detection and passive optical ranging. A formalism and simulatory results are given for lensed imaging of a point source at a movable image-plane. The MAFT peak indicates the best-focused image, and the image-displacement of the MAFT peak relates to source distance as a smooth one-to-one function, implying passive ranging capabilities. Primary advantages of our method include nonparametricity and technical simplicity, requiring only a lens and focus modulation. Thus MAFT ranging is desirable where compact, robust hardware and low computational overhead are key objectives.
Quantum interferences and gates with emitter-based coherent photon sources
Authors: Maillette de Buy Wenniger I. , Wein S. C. , Fioretto D. , Thomas S. E. , Antón-Solanas C. , Lemaître A. , Sagnes I. , Harouri A. , Belabas N. , Somaschi N. , Hilaire P. , Senellart J. , Senellart P.
Published: October 2024

Quantum emitters such as quantum dots, defects in diamond or in silicon have emerged as efficient single-photon sources that are progressively exploited in quantum technologies. In 2019, it was shown that the emitted single-photon states often include coherence with the vacuum component. Here we investigate how such photon-number coherence alters quantum interference experiments that are routinely implemented both for characterizing or exploiting the generated photons. We show that it strongly modifies intensity correlation measurements in a Hong–Ou–Mandel experiment and leads to errors in indistinguishability estimations. It also results in additional entanglement when performing partial measurements. We illustrate the impact on quantum protocols by evidencing modifications in heralding efficiency and fidelity of two-qubit gates.
Costs of primary healthcare presentations and hospital admissions for scabies and related skin infections in Fiji, 2018–2019
Authors: Akpan Edifofon , Thean Li Jun , Baskota Rabindra , Mani Jyotishna , Mow Maria , Kama Mike , Tuicakau Meciusela , Kado Joseph , Romani Lucia , Kaldor John , Engelman Daniel , Steer Andrew C. , Carvalho Natalie
Published: October 2024

Scabies and related bacterial skin and soft tissue infections (SSTIs) are highly prevalent in many tropical, low- and middle-income settings. These skin conditions contribute to higher healthcare costs and burdens on healthcare systems. The Big Skin Health Intervention Fiji Trial (“Big SHIFT”) carried out surveillance for scabies and SSTIs from July 2018 to June 2019 in the Northern Division of Fiji, an area with high prevalence of scabies, prior to a division-wide ivermectin-based mass drug administration (MDA) campaign. Using data from Big SHIFT, we sought to estimate the annual direct healthcare costs of scabies and related SSTIs for the Northern Division and extrapolate these costs to the national level. We categorized SSTIs as being potentially scabies-related or unlikely scabies-related, based on a previous study. The analysis used a health system perspective, with the main resource use categories of outpatient visits, bed days during admissions, medicines, and diagnostic tests. We extrapolated the total annual number of cases and direct healthcare costs for all divisions in Fiji based upon previous scabies and impetigo prevalence data across all divisions. The average cost per PHC presentation for scabies was US$17.7, and for potentially scabies-related SSTI was $18.3. The average cost per hospital admission for a potentially scabies-related SSTI case was $439. The estimated annual healthcare costs of scabies and related SSTIs in Fiji was US$3.0 million, with cost per capita of $3.3. Scabies and related SSTIs lead to a heavy economic burden in Fiji and prevention would reduce these healthcare costs.
The Retail Food Environment Index and its association with dietary patterns, body mass index, and socioeconomic position: A multilevel assessment in Mexico
Authors: Pineda Elisa , Stockton Jemima , Mindell Jennifer S.
Published: October 2024

In Mexico, 75% of the population are affected by overweight or obesity, and the availability and affordability of high-calorie-dense foods and beverages are high. This study tested the association between the retail food environment index (RFEI), dietary patterns, body mass index (BMI), and socioeconomic position (SEP) in Mexico. Cross-sectional diet, health, and sociodemographic population-based secondary data analyses were conducted. The RFEI was calculated by dividing the total number of fast-food outlets and convenience stores by the total number of supermarkets and fruit and vegetable stores per census tract area. Associations between BMI, dietary patterns, SEP and the RFEI were tested using multilevel linear regression, including interactions of the RFEI with SEP, gender, and age. Living in neighbourhoods with a higher RFEI was associated with a 0.01kg/m2 higher BMI (β = 0.01, 95%CI: 0.0005, 0.02, p = 0.04), equivalent to a mean 0.046 weight gain for a 1.60m tall person per 10% higher RFEI. Unhealthy dietary patterns were more likely in neighbourhoods with a higher RFEI (β = 0.100, 95%CI: 0.03, 0.12, p = 0.001). Multilevel linear regression showed that lower SEP households had a higher RFEI compared to higher SEP households (β = 0.020, 95% CI: -0.006 to 0.04, p = 0.10). Generalised structural equation models revealed a graded relationship between RFEI and SEP, showing that lower SEP households were exposed to a higher RFEI (β = 0.060, 95% CI: 0.05 to 0.07, p < 0.001.) The study identified significant associations between higher proportions of fast-food outlets and convenience stores, higher BMI, and unhealthy dietary patterns. It was particularly evident that low-income populations are more likely to be exposed to obesogenic food environments.