bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac Output Directly Influences Intracardiac Air After Venous Air Embolism: An Echocardiographic Model Comparing Position Change on Intracardiac Air Bubble Clearance
Authors: Marcellino Chris , Nelson James A. , Atkinson John L. D. , Pasternak Jeffrey J. , Abcejo Arnoley S.
Published: September 2024

BACKGROUND AND OBJECTIVES:

Venous air embolism (VAE) can cause significant morbidity and mortality. Prevention and management of VAE include cessation of air entrainment, positioning changes, and hemodynamic support. The degree to which position change and cardiac output (CO) moderate resolution of intracardiac air has not been rigorously studied using contemporary transesophageal echocardiography (TEE).

METHODS:

This observational cohort-type study aimed to identify the effect of supine vs sitting positioning on the movement and resolution of intracardiac air. In 20 patients undergoing seated neurosurgery, central venous air aspiration catheters were placed through the median basilic vein. TEE was used to estimate the time required for clearance of agitated microbubbles from the right atrium and ventricle in both the supine and sitting position. Estimates of CO were also obtained echocardiographically in each position.

RESULTS:

Average clearance time was faster in the sitting vs the supine position with no significant difference in CO. A negative correlation between CO and right atrial clearance time across all patients was demonstrated with a Pearson coefficient of −0.4 (95% CI −0.07, −0.65) with P = .02.

CONCLUSION:

During VAE, both patient position and CO can significantly affect how bubbles move through intracardiac chambers. However, augmenting CO during VAE may be clinically more feasible, efficient, and productive than changing positioning—especially during crises unless the changing in position is intended to halt the entrainment of air. Further TEE studies of intravascular air movement affected by other position changes (lateral, reverse Trendelenburg) and vasopressors should be considered.
Staphylococcus aureus lipid factors modulate melanoma cell clustering and invasion
Authors: Giese Morgan A. , Ramakrishnan Gayathri , Steenberge Laura H. , Dovan Jerome X. , Sauer John-Demian , Huttenlocher Anna
Published: September 2024

The microbiome can influence cancer development and progression. However, less is known about the role of the skin microbiota in melanoma. Here, we took advantage of a zebrafish melanoma model to probe the effects of Staphylococcus aureus on melanoma invasion. We found that S. aureus produces factors that enhance melanoma invasion and dissemination in zebrafish larvae. We used a published in vitro 3D cluster formation assay that correlates increased clustering with tumor invasion. S. aureus supernatant increased clustering of melanoma cells and was abrogated by a Rho-Kinase inhibitor, implicating a role for Rho-GTPases. The melanoma clustering response was specific to S. aureus but not to other staphylococcal species, including S. epidermidis. Our findings suggest that S. aureus promotes melanoma clustering and invasion via lipids generated by the lipase Sal2 (officially known as GehB). Taken together, these findings suggest that specific bacterial products mediate melanoma invasive migration in zebrafish.
The interplay of serotonin 5-HT1A and 5-HT7 receptors in chronic stress
Authors: Bijata Monika , Wirth Alexander , Wlodarczyk Jakub , Ponimaskin Evgeni
Published: September 2024

Serotonin regulates multiple physiological and pathological processes in the brain, including mood and cognition. The serotonin receptors 5-HT1AR (also known as HTR1A) and 5-HT7R (also known as HTR7) have emerged as key players in stress-related disorders, particularly depression. These receptors can form heterodimers, which influence their functions. Here, we explored the developmental dynamics of 5-HT1AR and 5-HT7R expression and validated heterodimerization levels in the brain of control and stressed mice. In control animals, we found that there was an increase in 5-HT1AR expression over 5-HT7R in the prefrontal cortex (PFC) and hippocampus during development. Using a chronic unpredictable stress as a depression model, we found an increase in 5-HT7R expression exclusively in the PFC of resilient animals, whereas no changes in 5-HT1AR expression between control and anhedonic mice were obtained. Quantitative in situ analysis of heterodimerization revealed the PFC as the region exhibiting the highest abundance of 5-HT1AR–5-HT7R heterodimers. More importantly, upon chronic stress, the amount of heterodimers was significantly reduced only in PFC of anhedonic mice, whereas it was not affected in resilient animals. These results suggest an important role of brain-region-specific 5-HT1AR–5-HT7R heterodimerization for establishing depressive-like behaviour and for development of resiliency.
Case Report: Unusual case of candy wrapper aspiration
Authors: Adhikari Santosh , Rayamajhi Amod , Bhattarai Tribhuwan , Upadhyay Shristi , Shrestha Sanjeet Kumar , Basnyat Buddha , Rayamajhi Ajit
Published: September 2024

Foreign body (FB) aspiration is a life-threatening medical emergency that usually presents with a history of choking episodes, followed by cough and shortness of breath. However, when the signs and symptoms are subtle, they can be easily missed by the parents or the child, causing delays in the diagnosis and management, suspecting other respiratory illnesses. Here, we report an eight years old neurologically stable girl without a history of choking episodes, with only subtle respiratory symptoms, with a candy wrapper stuck in the left bronchus missed by X-ray and computer tomography (CT)- scan of the chest and diagnosed and removed by flexible bronchoscopy.
SPECIALISED FINANCIAL COMPANIES AS AN INSTRUMENT OF ASSET SECURITISATION
Authors: Navalikhina Anna I.
Published: September 2024

The relevance of the topic is due to the increasing influence of Specialized Financial Companies in connection with the constant development of the investment market and the increasing need of society in innovative products, taking into account the lack of research in the Russian science and expert community. It should also be noted that Specialized Financial Societies are becoming an increasingly interesting instrument both abroad and in Russian corporate law, especially in view of the forthcoming “tax reform” in 2025.
The purpose of the study is to summarize the opinions of the expert-scientific community and dive into the legislation and law enforcement practice of foreign jurisdictions in order to identify positive aspects of regulation, gaps in the current Russian legislation and problems in legal regulation.
Materials and methods. The research was based on the following methods: factual method, in the form of analysis of the current legislation of Russia; comparative-legal method, allowing to evaluate the institution of Specialised Financial Companies from the point of view of approaches applied in various foreign jurisdictions; method of analysis and generalisation of materials in official Internet resources.
The result of the study is the identification of shortcomings in legal regulation, systematization of distinctive features of Specialized Financial Companies, identification of their advantages over other corporations, analysis of examples of the use of Specialized Financial Companies (SPV) in foreign countries, determination of their role and functions in the economy.
Stability of a Queue Fed by Scheduled Traffic at Critical Loading
Authors: Araman Victor F. , Glynn Peter W.
Published: September 2024

Performance of a queueing system with scheduled arrivals

A scheduled arrival sequence is one in which customers are scheduled to arrive at constant interarrival times, but each customer’s actual arrival time is perturbed from her scheduled arrival time by a random perturbation. In “Stability of a Queue Fed by Scheduled Traffic at Critical Loading”, V.F. Araman and P.W. Glynn consider a single server queue with deterministic service times in which customers arrive following a scheduled arrival process. Unlike a queue fed by renewal traffic, this queue is shown to be stable even when the utilization is equal to one. It is also shown that for finite mean perturbations, a necessary and sufficient condition for stability is when the positive part of the perturbation has bounded support, with no requirement on the negative part of the perturbation. Perhaps surprisingly, this criterion is not reversible, in the sense that such a queue can be stable for a scheduled traffic process in forward time, but unstable for the time-reversal of the same traffic process.
Clinical, oncological, and prognostic differences of patients with subsequent skeletal-related events in bone metastases
Authors: Hsieh Hsiang-Chieh , Yen Hung-Kuan , Hsieh Wen-Tung , Lin Ching-Wei , Pan Yu-Ting , Jaw Fu-Shan , Janssen Stein J. , Lin Wei-Hsin , Hu Ming-Hsiao , Groot Olivier
Published: September 2024

Aims

Advances in treatment have extended the life expectancy of patients with metastatic bone disease (MBD). Patients could experience more skeletal-related events (SREs) as a result of this progress. Those who have already experienced a SRE could encounter another local management for a subsequent SRE, which is not part of the treatment for the initial SRE. However, there is a noted gap in research on the rate and characteristics of subsequent SREs requiring further localized treatment, obligating clinicians to extrapolate from experiences with initial SREs when confronting subsequent ones. This study aimed to investigate the proportion of MBD patients developing subsequent SREs requiring local treatment, examine if there are prognostic differences at the initial treatment between those with single versus subsequent SREs, and determine if clinical, oncological, and prognostic features differ between initial and subsequent SRE treatments.

Methods

This retrospective study included 3,814 adult patients who received local treatment – surgery and/or radiotherapy – for bone metastasis between 1 January 2010 and 31 December 2019. All included patients had at least one SRE requiring local treatment. A subsequent SRE was defined as a second SRE requiring local treatment. Clinical, oncological, and prognostic features were compared between single SREs and subsequent SREs using Mann-Whitney U test, Fisher’s exact test, and Kaplan–Meier curve.

Results

Of the 3,814 patients with SREs, 3,159 (83%) patients had a single SRE and 655 (17%) patients developed a subsequent SRE. Patients who developed subsequent SREs generally had characteristics that favoured longer survival, such as higher BMI, higher albumin levels, fewer comorbidities, or lower neutrophil count. Once the patient got to the point of subsequent SRE, their clinical and oncological characteristics and one-year survival (28%) were not as good as those with only a single SRE (35%; p < 0.001), indicating that clinicians’ experiences when treating the initial SRE are not similar when treating a subsequent SRE.

Conclusion

This study found that 17% of patients required treatments for a second, subsequent SRE, and the current clinical guideline did not provide a specific approach to this clinical condition. We observed that referencing the initial treatment, patients in the subsequent SRE group had longer six-week, 90-day, and one-year median survival than patients in the single SRE group. Once patients develop a subsequent SRE, they have a worse one-year survival rate than those who receive treatment for a single SRE. Future research should identify prognostic factors and assess the applicability of existing survival prediction models for better management of subsequent SREs.

Cite this article: Bone Joint Res 2024;13(9):497–506.
Sensitivity enhanced temperature and strain sensor based on parallel hybrid interferometers and the Vernier effect
Authors: Sun Chentong , Ning Tigang , Pei Li , Zheng Jingjing , Wang Wensheng , Zhang Bingbing , Hou Huizhen , Zhang Dan
Published: September 2024

A fiber sensor with significantly enhanced temperature and strain sensitivities is proposed. This sensor, which comprises a fiber Sagnac interferometer (FSI) in parallel with an improved fiber modal interferometer (FMI), has been validated in experiments. The FSI consists of a section of polarization-maintaining fiber (PMF) and a 2×2 3 dB optical coupler (OC), serving as the sensing interferometer. The improved FMI with a higher extinction ratio (ER) consists of a core-offset structure, no core fiber (NCF), single-mode fiber (SMF), and few mode fiber (FMF), serving as the reference interferometer. Different Vernier effect envelopes have distinct responses to temperature and strain, thereby making the sensor a good choice for concurrent monitoring of temperature and strain variations. The experimental outcomes demonstrate an enhancement in both temperature and strain sensitivity, advancing from –1.33 nm/°C of a conventional single FSI to 22.26 nm/°C and from 2.83 to –50.99 pm/µɛ, respectively. The proposed sensor, with its advantages of exceptional sensitivity, uncomplicated design, and economical cost, provides what we believe is a novel and effective solution for the practical measurement of temperature and strain.
Gain performance and thermal effects of Nd:Glass and Nd,Y:SrF2 crystal
Authors: Zhang Yenan , Wang Jiangfeng , Li Xuechun , Guo Jiangtao , Lu Xinghua , Wang Xiaochao , Zhang Zhen , Jiang Dapeng , Su Liangbi , Fan Wei
Published: September 2024

The gain performance and thermal effects of Nd:glass (N31) and Nd,Y:SrF2 crystal are investigated and compared. The results show that, under the same pump conditions, Nd,Y:SrF2 can provide a small-signal gain similar to that of N31. The main advantages of Nd,Y:SrF2 are its weaker thermal effects and greater thermal-fracture limitations compared with those of N31. In this paper, the two gain media are compared in the form of rods whose diameter is 5 mm and length is 60 mm. The small-signal gain coefficients of N31 and Nd,Y:SrF2 are 1.39 and 1.46, respectively, at a pump energy of 1.5 J/1 Hz. The pump energy is set at 1.5 J/8 Hz to experimentally investigate their thermal effects. The thermal wavefront of N31 is 0.987λ at a repetition rate of 10 Hz, whereas that of Nd,Y:SrF2 is 0.679λ. In thermal destructive experiments, N31 fractured at an average pump power of 15 W (1.5 J/10 Hz), whereas Nd,Y:SrF2 fractured at a higher power of 27 W (1.5 J/18 Hz) owing to its excellent thermal conductivity, which is 7.28 times that of N31. These results indicate the potential of Nd,Y:SrF2 crystal as a gain medium for high-repetition-rate laser amplifiers.
Maximizing the FWM conversion efficiency in a PCF with a randomly varying pitch
Authors: Zhang Wei , Gattass Rafael R. , Shaw L. Brandon , Menyuk Curtis R. , Hu Jonathan
Published: September 2024

We theoretically investigate the generation of visible light using
four-wave mixing (FWM) in photonic crystal fibers (PCFs), whose input
is produced by a high-power continuous wave (CW) or quasi-CW fiber
laser. We analyze the impact on the conversion efficiency of the
randomly varying pitch along the fiber, which in turn leads to
variations of the FWM wavelength. We show that the conversion
efficiency is maximized when the mean pitch and hole diameters are
chosen so that the derivative of the FWM wavelength with respect to
the pitch is zero. We then use this criterion to determine the maximum
conversion efficiency over a wavelength range of 650–850 nm
with a pump at 1064 nm.
Detection of riboflavin concentration by sol-gel silica coated dual-peak long period fiber grating sensor
Authors: Dai Xinyi , Shi Jiuli , Zhao Xiangfen , Su Yudong , Dai Shixun , Zhang Peiqing
Published: September 2024

A dual-peak long period fiber grating (DP-LPFG)-based sensor was designed and fabricated for the sensitive detection of riboflavin concentration. LPFGs with a period of 163 μm and a cladding mode of LP0, 12 were inscribed on a standard single-mode silica fiber using a femtosecond laser direct writing technique. Coatings of silica-based materials doped with β-cyclodextrin (β-CD), prepared via the sol-gel method, were applied to the surface of the LPFGs for the detection of riboflavin. To investigate the impact of coating thickness on the sensing sensitivity, sol-gel coatings of different thicknesses were applied to the surface of the LPFG sensor. Experimental findings revealed that the sensor with a thickness of approximately 540 nm sol-gel coatings exhibited superior sensing performance. The detection limit of the prepared DP-LPFG sensor was tested to be 0.08 nM, and it exhibits a response time of less than 3 minutes, along with high sensitivity, excellent repeatability, and selectivity. Thus, this sensor holds significant promise for applications in disease treatment and diagnosis, as well as in ensuring food quality.
Free electron terahertz source based on dielectric gratings
Authors: Li Sirui , Jin Hang , Sun Jingbo , Wen Yongzheng , Zhou Ji
Published: September 2024

Terahertz wave sources are essential for the development of terahertz technology. A terahertz radiation source based on dielectric gratings driven by free electrons is proposed in this paper. Electrons emitted by the emitter excite spoof surface plasmons (SSPs) when passing above the structure. Simulation results demonstrate that dielectric gratings enhance the field intensity and electron-structure interaction compared with metal gratings. Additionally, different dielectric materials can be utilized to offer greater flexibility in adjusting radiation characteristics while keeping the structure simple and manufacturable. The use of dielectric materials reduces the metal ohmic loss in the terahertz band. The structure supports on-chip integration, offering a new approach for developing efficient and compact free electron terahertz sources.
Sensitivity-enhanced optical fiber sensor based on the Vernier effect for detection of ammonia in water
Authors: Li Yitong , Yang Yuqiang , Mu Xiaoguang , Li Yuting , Zhang Yuying , Mo Chengyu , Xia Han , Huang Zhihao
Published: September 2024

A sensitivity-enhanced optical fiber sensor for the detection of dissolved ammonia in water based on the Vernier effect is proposed and demonstrated. The sensor comprises a sensing Fabry-Perot interferometer (S-FPI) and a reference Fabry-Perot interferometer (R-FPI) in parallel. The S-FPI is an open cavity fabricated by the dislocation welding of single-mode fiber(SMF), which is filled with a mixture of ultraviolet-curable resin NOA 170 and Oxazine 170 perchlorate (O17). The R-FPI is a sealed cavity, which is constructed by fusion splicing of SMF and hollow core fiber (HCF). The proposed sensor is based on the chemical reaction between the dissolved ammonia and O17. This chemical reaction alters the refractive index (RI) of the S-FPI, resulting in a wavelength shift of the reflected spectrum. The two interferometers exhibit a nearly identical free spectral range (FSR), thereby enabling the generation of the Vernier effect, which markedly enhances the ammonia sensitivity of the sensor. Experimental results indicate that the sensor sensitivity is 0.34 nm/ppm in the dissolved ammonia range of 5-40 ppm, which is approximately 9.1 times that of the single S-FPI. The proposed sensor exhibits both good repeatability and a short response time, in addition to selectivity for the detection of ammonia.
Holographic multiplexing recording with an orthogonal polarized array
Authors: Xu Xianmiao , Zheng Shujun , Ke Shenghui , Yang Yi , Zheng Jihong , Li Xiong , Cao Qiang , Tan Xiaodi
Published: September 2024

This study combines tensor polarization holography theory and multichannel recording techniques and proposes a novel polarization encoding method, the orthogonal polarized array (OPA). This method can efficiently and independently reconstruct polarization holograms using accurate OPA waves in the reference-based multiplexing technique when the reference waves in the reading process have the same polarization state as those in the recording process. The novelty is that the multiplexing dimensions of the OPA can reach any number without limitations. Based on theoretical analyses of polarization hologram superposition characteristics and material characteristics, a polarization multiplexing holographic memory with an orthogonal linearly polarized array recording configuration was designed. The experimental results were verified, demonstrating the independent reconstruction of three and five holograms under array waves with different polarization combinations. In addition to high-density optical data storage, this study provides a new paradigm for high-capacity optical displays and information encryption applications.
High photoluminescence quantum yield and stability achieved by encapsulating MAPbBr3 QDs in UIO-66 and their application in LEDs
Authors: Liu Junhui , Li Songyuan , Han Junhe , Huang Mingju
Published: September 2024

Lead halide perovskite quantum dots (QDs) have been extensively studied due to their excellent photoelectric performance. However, the stability of MAPbBr3 QDs is affected by inevitable factors such as light, heat, and moisture, which limits their practical applications. In this work, stable metal-organic framework UIO-66 was synthesized via a solvothermal method, and the composite MAPbBr3@UIO-66 was prepared through an in-situ growth method. Owing to the wide bandgap, small pore size, and regular geometric structure, UIO-66 can confine the size and uniformity of the perovskite QDs encapsulated within the framework, maximally preserving the luminescent properties of the perovskite QDs. Furthermore, UIO-66 isolates the perovskite QDs from contact with polar water molecules in the air, significantly enhancing the stability of the perovskite QDs. The synthesized composite material exhibits high stability and excellent optical performance, with a photoluminescence quantum yield (PLQY) of up to 78.9% in an air environment. After being stored under natural conditions for 35 days, it still retains 65% of its high luminescence intensity and fluorescence quantum efficiency. When packaged into green and white LEDs, the LEDs demonstrate high brightness and good monochromaticity, maintaining stable brightness even after 2.5 hours of continuous operation. These superior characteristics indicate that the composite material MAPbBr3@UIO-66 has great potential for application in LED technology.
Quantitative phase imaging with two in-line holograms
Authors: Wen Xiu , Qiao Ziling , Wang Yiran , Liu Zhengjun
Published: September 2024

Quantitative phase imaging (QPI) has emerged as a practical technique for acquiring structural information from phase objects. Digital holography can realize phase detection, but it is limited by a spatial bandwidth product or affected by the overlap of conjugate images. The phase retrieval algorithm serves as an effective tool for QPI dealing with intensity patterns. Traditional phase retrieval algorithms heavily rely on strong support constraints or high data redundancy to accurately reconstruct the sample image. However, in single-frame phase retrieval algorithms, the precise acquisition of support constraints is notably challenging. The multiple-measurement spends much time on data acquisition and is unsuitable for dynamic sample observation. In this paper, we propose a novel, to the best of our knowledge, quantitative phase imaging method that utilizes only two in-line holograms. We have developed a phase retrieval algorithm based on ptychography, which eliminates twin-image and separates illumination background. The proposed method achieves high data utilization efficiency and can be employed for dynamic imaging.
Direct observation of the twisted intramolecular charge-transfer state in polycyclic purinium salts
Authors: Liu Hua , Yang Qi Liang , Qin Chao Chao , Yang Yong Gang , Liu Yu Fang
Published: September 2024

Based on femtosecond transient absorption spectroscopy (fs-TAS) of 3-methyl-7,8-diphenyl-3H-purino[6,1-a] isoquinolin-6-ium trifluoromethanesulfonate in dimethyl sulfoxide (DMSO), the stimulated emission (SE) signal redshifts from 400 to 500 nm in 4.8 ps. In a glycerol/DMSO mixed solution, when the glycerol content is 25% and 50%, the delay is extended to 6.9 and 68 ps, respectively. The theoretical emission spectrum in the scanning of potential energy curves demonstrates that the rotation of the φ2 with a lower energy barrier (16.1 kcal/mol) occurs prior to that of φ1. In addition, the purinium salt molecule has a twisted intramolecular charge transfer (TICT) process occurring from the locally excited (LE) state to the charge transfer (CT) state, and torsion of φ2 is restrained in high-viscosity environments, which induces the redshift of SE and its increasing lifetime.
Programmable multi-wavelength distributed feedback laser array integrated in a liquid crystal polymer waveguide
Authors: Wang Zhaoyi , Sun Peizhi , Yuan Conglong , Luo Duanbin , Shen Ning , Hu Honglong , Cheng Hongbo , Zheng Zhi-Gang
Published: September 2024

Liquid crystal (LC) distributed feedback (DFB) lasers hold significant potential for integrated photonics applications. However, limitations in wavelength spacing for wavelength switching, device size, and compatibility with other technologies have impeded advancements of the LC DFB laser in integration and responsiveness. Herein, we propose a thin-film multi-wavelength DFB laser array utilizing high-resolution patterned programmable nematic LC polymers, enabling rapid switching with high-resolution wavelength spacing between wavelength division multiplexing channels while maintaining a stable single longitudinal mode (SLM) for each laser. The underlying physical mechanism involves modulating the effective refractive index of the DFB laser by varying the LC molecules’ orientation angles between adjacent regions of the LC grating to achieve wavelength modulation. Additionally, a specialized LC waveguide design connects the DFB lasers, facilitating wavelength modulation as well as straight-line and bending propagation of the laser. Furthermore, the laser array demonstrates a relatively low energy threshold, facilitating its applications in high-integration scenarios.
Dual-channel intrinsic and nonlinear chirality for an all-optical logic operation
Authors: Zong Shu , Cai Shijie , Liu Xiaoshan , Chen Juan , Liu Guiqiang , Chen Jing , Tang Chaojun , Liu Zhengqi
Published: September 2024

Chiral metasurfaces hold excellent performance in enhancing spin-dependent light–matter interaction, showing broad application prospects in areas such as chiral imaging, chiral light sources, and chiral sensing. However, utilizing resonant metasurfaces to achieve all-optical logic gates has not been reported yet. In this work, dual-channel intrinsic and nonlinear chiroptical responses are achieved on lithium niobate metasurfaces. The combination of bound states in the continuum (BICs) resonant modes with chiral metasurfaces has revealed its linear and nonlinear chirality. The metasurface achieves linear circular dichroism above 0.9 and nonlinear circular dichroism close to 0.9 on the dual-band. Based on the second-order nonlinear chiroptical response, multiple all-optical logic gates (including NOT, OR, NAND, AND, and NOR) can be realized on the chiral metasurfaces. Our results confirm the operability of resonant metasurfaces in realizing all-optical logic gates, offering a potentially promising approach for the development of new, to the best of our knowledge, all-optical logic devices.
Unpaired data training enables super-resolution confocal microscopy from low-resolution acquisitions
Authors: Trujillo Carlos , Thompson Lauren , Skalli Omar , Doblas Ana
Published: September 2024

Supervised deep-learning models have enabled super-resolution imaging
in several microscopic imaging modalities, increasing the spatial
lateral bandwidth of the original input images beyond the diffraction
limit. Despite their success, their practical application poses
several challenges in terms of the amount of training data and its
quality, requiring the experimental acquisition of large, paired
databases to generate an accurate generalized model whose performance
remains invariant to unseen data. Cycle-consistent generative
adversarial networks (cycleGANs) are unsupervised models for
image-to-image translation tasks that are trained on unpaired
datasets. This paper introduces a cycleGAN framework specifically
designed to increase the lateral resolution limit in confocal
microscopy by training a cycleGAN model using low- and high-resolution
unpaired confocal images of human glioblastoma cells. Training and
testing performances of the cycleGAN model have been assessed by
measuring specific metrics such as background standard deviation,
peak-to-noise ratio, and a customized frequency content measure. Our
cycleGAN model has been evaluated in terms of image fidelity and
resolution improvement using a paired dataset, showing superior
performance than other reported methods. This work highlights the
efficacy and promise of cycleGAN models in tackling super-resolution
microscopic imaging without paired training, paving the path for
turning home-built low-resolution microscopic systems into low-cost
super-resolution instruments by means of unsupervised deep
learning.
Multiplexed quantum frequency conversion
Authors: Tang Chao , Ma Zhaohui , Li Zhan , Sua Yongmeng , Huang Yu-Ping
Published: September 2024

We study multiplexed quantum frequency conversion (m-QFC) on a single
waveguide, where a single pump beam simultaneously converts multiple
signal beams at distinct wavelengths. Using a three-peak periodically
poled lithium niobate (PPLN) waveguide, we demonstrate the multiplexed
upconversion in the telecom band with internal efficiencies up to
73.6%. Tested with a
multichannel photon-pair source, the quantum correlation is preserved
well after the conversion, with coincidence-to-accidental ratio
reaching 767. These results highlight a viable device approach to
multiplexed quantum key distribution, quantum sensing, and quantum
computing.
Ultracompact all-fiber self-transceiving ultrasonic probe with an enhanced working distance
Authors: Yu Kaiyan , Shao Zhihua , Kang Wanwan , Liang Ruiming , Qiao Xueguang
Published: September 2024

All-optical ultrasonic probes exhibit notable benefits in ultrasonic detection and imaging. Typically, two separate optical fibers are used for excitation and detection, yet limited research has explored the integration of both functionalities within a single fiber. In this Letter, to our knowledge, a new method for fabricating an all-fiber self-transceiving ultrasonic probe is proposed with a lateral dimension of less than 500 µm. Double cladding fiber (DCF) is spliced with a short segment of thin-diameter single-mode fiber (TDSMF), which is then embedded into a fiber bubble to form a Fabry–Perot cavity, and the bubble surface is coated with a composite material layer. The pulsed laser propagates through the inner cladding of DCF and leaks from the splicing point of DCF–TDSMF, inducing the material excitation for efficient ultrasound generation. The core-guided detection laser is directed to the TDSMF end, entering the bubble microcavity and inducing an optical interference for weak echo detection. The emitting functionality produces an ultrasound with a −6 dB bandwidth of 17.5 MHz and a peak frequency of 6.29 MHz, which is well-matched with the fiber microcavity’s response frequency of 3.29 MHz. Through self-transceiving experiments, low-noise pulse-echo signals are captured at varying working distances of up to 3.78 cm. The proposed probe exhibits great potential in biomedical and industrial fields due to its all-fiber miniaturization and enhanced-distance detection capability.
Multiwavelength highly transient stimulated Raman scattering on dual Raman modes in Sr(MoO4)0.8(WO4)0.2 and Sr(MoO4)0.4(WO4)0.6
Authors: Kochukov Yury A. , Gubina Ksenia A. , Tereshchenko Dmitry P. , Smetanin Sergei N. , Papashvili Alexander G. , Chizhov Pavel A. , Ushakov Alexander A. , Shukshin Vladislav E. , Dunaeva Elizaveta E. , Voronina Irina S. , Ivleva Lyudmila I.
Published: September 2024

For the first time to our knowledge, multiwavelength, highly transient, single-pass stimulated Raman scattering with a low wavelength spacing on dual (stretching and bending) Raman modes in Sr(MoO4)0.8(WO4)0.2 and Sr(MoO4)0.4(WO4)0.6 solid solutions in a range of 1000–1300 nm (transparence window of biological tissue) under ultrafast chirped pulse laser pumping is comparatively investigated in the interests of multicolor two-photon imaging of a living tissue. For both the solid solutions, the optimum range (1–5 ps) of chirped pump pulse durations for multiwavelength Raman conversion on dual Raman modes was wider than for SrMoO4 (2–3 ps) due to the higher integral cross section of the bending Raman mode. Higher efficient SRS conversion took place at negative chirping of the pump pulse with its stretching from 0.25 ps up to 5 ps due to the compensation of a positive chirp caused by nonlinear phase modulation with total Raman conversion efficiency of up to 36% for Sr(MoO4)0.8(WO4)0.2 and 49% for Sr(MoO4)0.4(WO4)0.6. The highest number (five) of Stokes components in the desired range (1000–1300 nm) was observed in the optimum Sr(MoO4)0.4(WO4)0.6 solid solution, which has the Raman modes with comparable intensities.
Role of the inverse Čerenkov effect in the formation of ultrashort Raman solitons in silica microspheres
Authors: Osipov Alexey N. , Anashkina Elena A. , Yulin Alexey V.
Published: September 2024

We theoretically demonstrate a new regime, to the best of our knowledge, of the formation of ultrashort optical solitons in spherical silica microresonators with whispering gallery modes. The solitons are driven by a coherent CW pump at the frequency in the range of normal dispersion, and the energy is transferred from this pump to the solitons via two channels: the Raman amplification and inverse Čerenkov effect. We discuss three different regimes of soliton propagation and we also show that these Raman solitons can be controlled by weak coherent CW signals.
Single-step and parallel high-speed fabrication for Au micro-/nanostructures
Authors: Fu Yanzhe , Wang Bing , Wei Jiayong , Chen Sai , Xiong Mengfei , Ding Xiang , Li Jiebo
Published: September 2024

Patterns fabricated with Au nanoparticles (Au NPs) exhibit significant potential in fields such as micro-optics and bioelectronics. However, the current manufacturing methods still suffer from complex processes and low efficiency. In this work, we propose a high-speed manufacturing method for Au micro-/nanostructures based on spatiotemporal focusing and maskless lithography, achieving a throughput of 0.5 mm2/min. The surface electric field enhancement of the structure was confirmed using Raman spectroscopy, indicating that this method holds significant promise for metasurface, biosensing, and plasmonic chemistry.
Ultra-efficient surface grating couplers for chip-to-fiber and chip-to-free-space coupling based on single-beam radiation
Authors: Sánchez-Postigo Alejandro , Ginel Pablo , Schmid Jens , Hadij-ElHouati Abdelfettah , Ortega-Moñux Alejandro , Wangüemert-Pérez J. Gonzalo , Halir Robert , Cheben Pavel , Molina-Fernandez Inigo
Published: September 2024

Surface grating couplers, such as fiber-chip grating couplers and optical antennas, are fundamental devices in photonic integrated circuits, as they enable the coupling of light between the chip and an external medium. An important metric of surface grating couplers is the coupling efficiency, and high values, greater than -1 dB, are required for applications in quantum technology, light detection and ranging, and optical interconnects. Surface grating couplers typically suffer from radiation loss to the substrate, which significantly limits their coupling efficiency. Here we propose a novel grating-coupling concept that utilizes a high-refractive-index upper cladding to frustrate radiation orders to the substrate by operating in a single-beam diffraction regime. To illustrate this concept, we report the design of an easily fabricable silicon surface grating coupler with an unprecedented coupling efficiency of -0.20 dB to a single-mode optical fiber. Furthermore, the proposed strategy allows us to design an evanescently coupled millimeter-long optical antenna with a coupling efficiency of -0.1 dB to free space. Additionally, an ultra-fast wavelength-tunable beam steering of 0.37º/nm is achieved, which corresponds to more than a 2.5-fold enhancement over comparable silicon antennas. These results represent a pathway for a new set of photonic integrated interfaces for applications in which high-efficiency chip-to-fiber and chip-to-free-space coupling is critical.
Accurate multi-population imputation of MICA, MICB, HLA-E, HLA-F and HLA-G alleles from genome SNP data
Authors: Tammi Silja , Koskela Satu ,   Blood Service Biobank, Hyvärinen Kati , Partanen Jukka , Ritari Jarmo
Published: September 2024

In addition to the classical HLA genes, the major histocompatibility complex (MHC) harbors a high number of other polymorphic genes with less established roles in disease associations and transplantation matching. To facilitate studies of the non-classical and non-HLA genes in large patient and biobank cohorts, we trained imputation models for MICA, MICB, HLA-E, HLA-F and HLA-G alleles on genome SNP array data. We show, using both population-specific and multi-population 1000 Genomes references, that the alleles of these genes can be accurately imputed for screening and research purposes. The best imputation model for MICA, MICB, HLA-E, -F and -G achieved a mean accuracy of 99.3% (min, max: 98.6, 99.9). Furthermore, validation of the 1000 Genomes exome short-read sequencing-based allele calling against a clinical-grade reference data showed an average accuracy of 99.8%, testifying for the quality of the 1000 Genomes data as an imputation reference. We also fitted the models for Infinium Global Screening Array (GSA, Illumina, Inc.) and Axiom Precision Medicine Research Array (PMRA, Thermo Fisher Scientific Inc.) SNP content, with mean accuracies of 99.1% (97.2, 100) and 98.9% (97.4, 100), respectively.
Facilitating pathway and network based analysis of RNA-Seq data with pathlinkR
Authors: Blimkie Travis M. , An Andy , Hancock Robert E. W.
Published: September 2024

R package pathlinkR is designed to aid transcriptomic analyses by streamlining and simplifying the process of analyzing and interpreting differentially expressed genes derived from human RNA-Seq data. It provides an integrated approach to performing pathway enrichment and network-based analyses, while also producing publication-quality figures to summarize these results, allowing users to more efficiently interpret their findings and extract biological meaning from large amounts of data. pathlinkR is available to install from the software repository Bioconductor at https://bioconductor.org/packages/pathlinkR/, with support available through the Bioconductor forums. The code, example, and supporting data is available on the GitHub repository at https://github.com/hancockinformatics/pathlinkR, under the GPL-3.0 license, where users may report problems or make suggestions using GitHub’s issue system.
Evolution recovers the fitness of Acinetobacter baylyi strains with large deletions through mutations in deletion-specific targets and global post-transcriptional regulators
Authors: Gifford Isaac , Suárez Gabriel A. , Barrick Jeffrey E.
Published: September 2024

Organelles and endosymbionts have naturally evolved dramatically reduced genome sizes compared to their free-living ancestors. Synthetic biologists have purposefully engineered streamlined microbial genomes to create more efficient cellular chassis and define the minimal components of cellular life. During natural or engineered genome streamlining, deletion of many non-essential genes in combination often reduces bacterial fitness for idiosyncratic or unknown reasons. We investigated how and to what extent laboratory evolution could overcome these defects in six variants of the transposon-free Acinetobacter baylyi strain ADP1-ISx that each had a deletion of a different 22- to 42-kilobase region and two strains with larger deletions of 70 and 293 kilobases. We evolved replicate populations of ADP1-ISx and each deletion strain for ~300 generations in a chemically defined minimal medium or a complex medium and sequenced the genomes of endpoint clonal isolates. Fitness increased in all cases that were examined except for two ancestors that each failed to improve in one of the two environments. Mutations affecting nine protein-coding genes and two small RNAs were significantly associated with one of the two environments or with certain deletion ancestors. The global post-transcriptional regulators rnd (ribonuclease D), csrA (RNA-binding carbon storage regulator), and hfq (RNA-binding protein and chaperone) were frequently mutated across all strains, though the incidence and effects of these mutations on gene function and bacterial fitness varied with the ancestral deletion and evolution environment. Mutations in this regulatory network likely compensate for how an earlier deletion of a transposon in the ADP1-ISx ancestor of all the deletion strains restored csrA function. More generally, our results demonstrate that fitness lost during genome streamlining can usually be regained rapidly through laboratory evolution and that recovery tends to occur through a combination of deletion-specific compensation and global regulatory adjustments.
Temperature dependence of mosquitoes: Comparing mechanistic and machine learning approaches
Authors: Athni Tejas S. , Childs Marissa L. , Glidden Caroline K. , Mordecai Erin A.
Published: September 2024

Mosquito vectors of pathogens (e.g., Aedes, Anopheles, and Culex spp. which transmit dengue, Zika, chikungunya, West Nile, malaria, and others) are of increasing concern for global public health. These vectors are geographically shifting under climate and other anthropogenic changes. As small-bodied ectotherms, mosquitoes are strongly affected by temperature, which causes unimodal responses in mosquito life history traits (e.g., biting rate, adult mortality rate, mosquito development rate, and probability of egg-to-adult survival) that exhibit upper and lower thermal limits and intermediate thermal optima in laboratory studies. However, it remains unknown how mosquito thermal responses measured in laboratory experiments relate to the realized thermal responses of mosquitoes in the field. To address this gap, we leverage thousands of global mosquito occurrences and geospatial satellite data at high spatial resolution to construct machine-learning based species distribution models, from which vector thermal responses are estimated. We apply methods to restrict models to the relevant mosquito activity season and to conduct ecologically plausible spatial background sampling centered around ecoregions for comparison to mosquito occurrence records. We found that thermal minima estimated from laboratory studies were highly correlated with those from the species distributions (r = 0.87). The thermal optima were less strongly correlated (r = 0.69). For most species, we did not detect thermal maxima from their observed distributions so were unable to compare to laboratory-based estimates. The results suggest that laboratory studies have the potential to be highly transportable to predicting lower thermal limits and thermal optima of mosquitoes in the field. At the same time, lab-based models likely capture physiological limits on mosquito persistence at high temperatures that are not apparent from field-based observational studies but may critically determine mosquito responses to climate warming. Our results indicate that lab-based and field-based studies are highly complementary; performing the analyses in concert can help to more comprehensively understand vector response to climate change.
Child mental health predictors among camp Tamil refugees: Utilizing linear and XGBOOST models
Authors: Saleh Muna , Amona Elizabeth , Kuttikat Miriam , Sahoo Indranil , Chan David , Murphy Jennifer , Kim Kyeongmo , George Hannah , Lund Marianne
Published: September 2024

While the association between migration and deteriorated refugee mental health is well-documented, existing research overwhelmingly centers on adult populations, leaving a discernible gap in our understanding of the factors influencing mental health for forcibly displaced children. This focus is particularly noteworthy considering the estimated 43.3 million children who are forcibly displaced globally. Little is known regarding the association between family processes, parental and child wellbeing for this population. This study addresses these gaps by examining the relationship between parental mental health and child mental health among refugees experiencing transmigration. We conducted in-person structured survey interviews with 120 parent-adolescent dyads living in the Trichy refugee camp in Tamil Nadu, India. Descriptive, multivariate analysis (hierarchical regression), and Machine Learning Algorithm (XGBOOST) were conducted to determine the best predictors and their importance for child depressive symptoms. The results confirm parental mental health and child behavioral and emotional factors are significant predictors of child depressive symptoms. While our linear model did not reveal a statistically significant association between child mental health and family functioning, results from XGBOOST highlight the substantial importance of family functioning in contributing to child depressive symptoms. The study’s findings amplify the critical need for mental health resources for both parents and children, as well as parenting interventions inside refugee camps.
The impact of city-county merger on firm-level total factor productivity—Evidence from China
Authors: Yin Sisi , Shen Zuyi , Gao Yunshu
Published: September 2024

This study examines the potential negative effects of city-county mergers on firm-level total factor productivity (TFP). A theoretical framework is established to explain how city-county mergers could lead to higher institutional and non-institutional costs, thus influencing government decision-making and resource allocation. As a result, firms operating in the economy will absorb these costs and adjust their behavior accordingly. By employing Chinese firm-level data in a difference-in-differences approach, this study finds a statistically significant negative effect of transitioning county-level cities into municipal districts (TCD) on firm-level productivity. Additionally, this study identifies the financial situation of reformed governments and the internal environment of firms as two mechanisms through which the TCD reform influences firm-level productivity.