bluuebunny/crossref_metadata_2025 huggingface dataset:
Male urethral diverticulum squamous cell carcinoma containing a calculus: a rare entity
Authors: Zhang Y , Lian X , Ma D , Wu L , Guo K
Published: May 2023

Male urethral diverticula with calculi have a low incidence. It is extremely rare when the diverticulum accompanied with carcinoma. We report a case of diverticulum of the male urethra containing giant calculi which developed into squamous cell carcinoma. The patient initially presented with lower urinary tract symptoms and a hard, painless perineal mass. We believe that the process of diagnosis and treatment is of great significance in clinical practice.
A pilot study to investigate the effect of topical microporous polysaccharide haemospheres on outcomes following robot-assisted radical prostatectomy
Authors: Abou Chedid W , Janardanan S , Kavanagh L , Eden C
Published: May 2023

Introduction

Controlling bleeding without disturbing the anatomy and function of the structures in the prostate bed remains a significant challenge during radical prostatectomy (RP).

Materials and methods

Five grams of powdered microporous polysaccharide haemospheres (MPH) was applied to the prostate bed at the end of robot-assisted RP in 422 consecutive patients. Continence was defined as no pads and potency as the ability to have penetrative sex with or without PDE5 inhibitors in previously potent, non-diabetic men aged <70 years following bilateral intra- or inter-fascial neurovascular bundle (NVB) preservation.

Results

In total, 95.3% of patients had nerve preservation and the mean operating time and blood loss were 142 minutes and 200ml, respectively. There were no intraoperative complications, and the postoperative transfusion rate was 0.2%. The mean hospital stay was 1.7 nights, and duration of catheterisation was 12 days. Final pathology demonstrated a mean prostate weight of 40.0g and 14.5% replacement by cancer, most commonly Gleason 7. The positive surgical margin rate for pT2 tumours was 10.0%. Biochemical recurrence was 2.1% at a mean follow-up of 18.0 months. Continence and potency rates at 4 weeks and 1 year after surgery were 76.4% and 97.7% and 27.8% and 78.1%, respectively. The trifecta and pentafecta rates 1 year after surgery were 53.1% and 45.8%.

Discussion and conclusion

Powdered MPH applied to the prostate bed at the end of robot-assisted RP appears to be a safe, easily applied and useful adjunct to conventional haemostasis. The suggestion that it might also improve the functional outcomes of RP merits further investigation in the context of a randomised trial.
Surgeons’ user experience of telemedicine in surgical consultations during the COVID-19 pandemic, with an emphasis on general surgical consultations
Authors: Kumaran NK , Salama Y , Karmakar BK
Published: May 2023

Background

The COVID-19 pandemic and the eventual national lockdown in the UK brought a halt to the face-to-face outpatient appointments at most NHS hospitals. Owing to this, clinicians have had to switch to other means of consultation, to maintain continuity of care. This survey was done to see how surgeons perceive telemedicine as part of their surgical consultations.

Methods

A questionnaire was piloted and re-designed following which an improved questionnaire was circulated among all users of telemedicine in surgical specialties through social media platforms. The results were analysed using smart survey software.

Results

Seventy per cent of the respondents had never used telemedicine before the COVID-19 pandemic. Three-quarters of the respondents found difficulty in assessing patients preoperatively. A significant proportion were worried about confidentiality and data security. The other concerns expressed were difficulty in building a rapport and the absence of a legal framework to support the surgeons in the transition. Despite some concerns, most of them were in favour of using telemedicine in the future with some improvements.

Conclusion

As the pandemic prevented people from attending face-to-face appointments, remote consultations were stepped up to help overcome the difficulties. Screening services were suspended and treatment accumulated. Telemedicine will be a corner-stone service as healthcare systems attempt to tackle this backlog. The already existing software need to be further explored. Future studies must address the use of telemedicine in preoperative consultations. Regulatory bodies must ensure that there is adequate legal framework in place so that clinicians continue to embrace telemedicine.
Titanium miniplate removal after joint orthodontic–orthognathic surgery treatment: a 10-year retrospective hospital-based audit
Authors: Adatia A , Padashi-Fard M , Adali NS , Camilleri AC
Published: May 2023

Introduction

The reported incidence of titanium miniplate removal after orthognathic surgery varies widely, making delivery of risk information to patients problematic. This variation relates to potential biases introduced during the study design, for example, with the pooling of different patient types, creating heterogeneous study samples. This study reduces sampling bias by limiting the cohort to only consecutive orthognathic cases. The primary aim of the study was to identify the incidence of miniplate removal following orthognathic surgery. The secondary aim was to assess the indications and any risk factors for miniplate removal.

Methods

Data from the clinical records of 907 orthognathic surgery cases treated within a centralised oral and maxillofacial hospital service over a 10-year period were collected by two operators and analysed. Every identified case qualified for inclusion. Patient demographics (age, sex, medical comorbidity, smoking), operations (type of surgery, duration, third molar removal, complications) and the indication, timing and site of miniplate removal were analysed.

Results

Only 19 patients required postoperative miniplate removal, with the most common indication being infection (63%). There was no significant difference in any of the factors assessed except that significantly more miniplates were removed from female patients (68%) (p<0.001) and from mandibular sites (84.2%) (p=0.003).

Conclusions

The incidence of miniplate removal for this sample was 2.1%. Female sex and miniplate location in the mandible were the only statistically significant risk factors for miniplate removal.
How to WHO: lessons from aviation in checklists and debriefs
Authors: Guy IA , Kerstein RL , Brennan PA
Published: May 2023

Introduction

The World Health Organization (WHO) surgical safety checklist (SSC) has had an overall positive impact; however, it has not completely prevented adverse events and compliance with the checklist varies. The aviation industry is considered to have better engagement with their safety checklists, reporting not only safety improvements, but also a cultural shift in their checklist philosophy over recent years.

Methods

We explored the personal attitudes of pilots working in the aviation industry to identify principles of an effective checklist philosophy that could be transposed to the healthcare setting to empower more effective, consistent and ultimately successful implementation of the WHO SSC. A questionnaire was developed by the authors. Three airline pilots were interviewed via telephone, and asked questions regarding the logistics of and attitudes to checklists in the aviation industry.

Results

Several key factors for successful checklist implementation were identified. These include regular training and education on human factors and the checklist’s purpose, and institution of an atmosphere that is receptive, engaged and welcoming. Much can be learned from the aviation industry, where not only has the incidence of adverse events decreased, but the attitudes of people working in the industry have also transformed.

Conclusion

The WHO SSC is an invaluable tool used in healthcare settings worldwide. However, it is not a standalone commodity. To be effective, it necessitates steadfast engagement from the team members involved in its implementation. Human and checklist must work in partnership, using each other’s strengths and fallibilities, to optimise outcomes and prevent risks to patient safety.
Junior doctors’ wellbeing at peak and post-peak pandemic: a repeated cross-sectional study
Authors: Doulias T , Thrikandiyur AA , Titus N , Soundararasha K , Coxon A , Amarantidis E , Arulampalam T
Published: May 2023

Introduction

The impact of the COVID-19 pandemic on healthcare professionals has been significant. The aim of this study was to explore the mental state and wellbeing of UK junior doctors at different phases of the initial outbreak.

Methods

This is a cross-sectional study of UK-based junior doctors’ perceptions of threat and support during and after the first wave of the COVID-19 pandemic. Levels of anxiety, depression, post-traumatic stress disorder symptoms and use of coping mechanisms were explored through a Google questionnaire.

Results

196 participants were included in this study (93 in period A and 103 in period B). Junior doctors reported feeling increased risk (p=0.001) and increased fear of contracting the virus (p<0.001) during period A. Increased levels of severe anxiety (Generalized Anxiety Disorder-7 score >15) along with increased cases level of depression (Patient Health Questionnaire-9 score >10) were reported for both periods. Junior doctors described suffering more frequently with flashbacks (p=0.006) and nightmares (p=0.024) in comparison with senior colleagues during period A. During period A, 21.4% of participants felt isolated at work (p<0.001), whereas 13% reported being easily annoyed on a daily basis, 11.7% reported very low morale (p<0.001) and 66% were not aware of any psychological support being available. The use of exercise, peer support and mindfulness apps increased during period B (p=0.023).

Conclusions

Healthcare systems need to urgently establish robust psychological support mechanisms and infrastructure to protect junior doctors and provide institutional resilience against the adverse consequences of the long physical and mental battle with COVID-19.
Patients’ expectation of postoperative course and satisfaction following cardiac surgery
Authors: Mani K , Luttman J , Nowell J , Carrol A , Jahangiri M
Published: May 2023

Introduction

In patients undergoing cardiac surgery, preoperative concerns, expectations of the impact of surgery, anticipated recovery timelines, and pre- and postoperative education, which impact recovery and quality-of-life, are not well documented. These factors are important with the increase in virtual consultations, the availability of internet-based information and increased use of minimally invasive surgical procedures.

Methods

Patients who underwent cardiac surgery between January 2016 and December 2019 took part in an online survey examining preoperative concerns, information provision, use of digital channels, satisfaction with surgery, impact on health and resumption of daily activity. 80 patients completed the survey.

Results

There was a high rate of overall post-surgical satisfaction (86%); 71% of respondents reported an improvement in physical health, 45% in mental health and 70% in their quality-of-life. The usefulness of information provided by the National Health Service varies across different stages of the patient experience. Although approximately 90% of respondents found the information provided at each stage at least ‘somewhat’ helpful, the proportion who found the information ‘very’ helpful was lower (68% for pre-procedure; 55% for post-discharge). The majority (79%) said that they felt prepared for their operation. Survey responses highlighted areas of lower understanding, including survival rate, levels of postoperative pain, duration of hospital stay and when the patient could return to normal physical activity.

Conclusions

Levels of satisfaction with the outcomes of heart surgery are high, and the majority of patients report positive health outcomes. However, there is room for improvement in patients’ understanding of survival rate and level of pain post-procedure. There is also a clear desire among patients for a more surgical team-based face-to-face consultation.
Tooth Wear: An Authoritative Reference for Dental Professionals and Students Third edition
Authors: Djemal Serpil
Published: May 2023

Serpil Djemal reviews the third edition of Tooth Wear: An Authoritative Reference for Dental Professionals and Students.
Thermo-Hydric Modeling of the Water Retention Curve Based on the Hydric Model of Van Genuchten
Authors: Tewfik Belal , Moulay Smaine Ghembaza
Published: May 2023

In this paper, we propose an extension for a model of unsaturated soils developed by Van Genuchten (1980) and obtain a thermos-hydric model to study the influence of temperature on the water retention curve. A brief presentation of the model is described using the independent parameter modeling method. The proposed hydrometric model makes it possible to predict, from the experimental measurements carried out on drainage-humidification paths for an ambient temperature, the WRC (water retention curve) at high temperatures, while knowing the initial state of the soil studied (Compacted or in the form of a paste). We show in this model the existence of the hysteresis phenomenon between the drainage and humidification path and the shift of the downward retention curves showing a slight decrease in the water content as the temperature increases. To validate this model, three experimental results from the literature are simulated. The results obtained by simulating the experimental curves show the ability of the proposed model to predict WRC at high temperatures. These results considerably reduce the number of experimental trials in geotechnical and geothermal unsaturated soils.
Impact of Natural Pozzolan and the Degree of Circularity of Aggregates on the Thickness, Strength and Durability of ITZ in Concrete (Modeling and Experimentation)
Authors: Loumachi Lazhar , Mezghiche Bouzidi , Belkadi Ahmed Abderraouf
Published: May 2023

The interfacial transition zone (ITZ) has a significant negative impact on the structural performance of concrete. This negative impact can be ameliorated by introducing mineral additions into the concrete. In this study, different forms (degree of circularity) of coarse aggregates and three contents (10 %, 15 % and 20 %) of mineral addition (natural pozzolan) were used to prepare ordinary concrete. This article aims to determine the optimal and effective mixture (the best form of aggregate and addition). This article aims to determine the optimal and efficient mixture (the best form of aggregate and addition) on the basis of mechanical (compressive strength), and chemical (immersion in 3.5 % H2SO4 solution) tests. Furthermore, the effect of the interaction between the aggregate and the modified cementitious matrix was analyzed and discussed using the scanning electron microscope (SEM). The results show that the effect of the addition of 20 % pozzolana improves the aggregate/matrix transition zone, which made it possible to develop a maximum compressive strength at 60 days (51 MPa). In addition, the effect of mineral additions varies depending on the shape of the coarse aggregate. Thus, an effective numerical modeling of the compressive strength is based on the approach of the full factorial design taking into account the degree of circularity of the coarse aggregates and the content of the pozzolan.
Development of a Portable Universal Testing Machine for Investigating the Mechanical Properties of Medium-Strength Materials
Authors: Rizal Muhammad , Aulia Udink , Yudiansyah Radinal
Published: May 2023

The tensile test is reliable for revealing the fundamental stress-strain relationship. However, researchers have challenges when applying sufficient equipment to comprehend and assess the tensile characteristics of low-to-medium-strength materials. This study describes the design and construction of a portable universal testing machine (UTM) for investigating the mechanical characteristics of medium-strength materials. The components of this machine include two stepper motors, a load cell, a load cell amplifier, a linear potentiometer, and a data acquisition system. The capability of this machine component is designed for a load of 10 kN with a maximum stroke of 150 mm with vertical motion. Samples of jute and glass fiber composites were tested at room temperature on this machine. The generated results were compared with those obtained from a commercial UTM to validate the developed machine. The values of the mechanical characteristics that a commercial UTM measured are quite similar to those acquired from the measurements that were taken by this machine. The conclusion is that this testing machine is simple, portable, reliable, and might be constructed cheaply
Utilization of Unmanned Aerial Vehicle (UAV) for Topographic Survey Using Ground Control Points (GCP) from Geodetic GNSS
Authors: Nizamuddin Nizamuddin , Wirandha Freddy Sapta , . Ardiansyah
Published: May 2023

In connection with the development plan of the USK campus II area, it is necessary to map the area to support and complete the necessary data. Mapping with an Unmanned Aerial Vehicle (UAV) is a strategy or way for large-scale mapping with a faster and more efficient time. It can save time compared to using conventional survey methods. Ground Control Point (GCP) measurements are carried out with geodetic GNSS to improve the accuracy/correction of the geometry of the aerial portrait results. This research aims to provide preliminary information about the topographic conditions and current appearance of the USK campus II development location. The results of the aerial photo research with a spatial resolution of 5 cm/pixel show that most of the area looks green, which is a forest area. Some areas in the west and north, such as in the rectorate block, are C excavation mining areas. Based on contour data in the USK II area, the PON block's ground elevation is 66 to 301 meters, in the faculty block, 50 to 260 meters, and in the rectorate block, 90 to 188 meters.
Far-field mid-infrared microscopy via spatial frequency shifting of evanescent waves in photorefractive nematic liquid crystal
Authors: Liu Yan , Han Jing , Xu Qinfeng , Zhu Linwei , Guo Jinjia , Chen Jiannong
Published: May 2023

Mid-infrared wavelength has unique advantages in revealing the nanostructures and molecular vibrational signatures. However, the mid-infrared subwavelength imaging is also limited by diffraction. Here, we propose a scheme for breaking the limitation in mid-infrared imaging. With the assistance of orientational photorefractive grating established in nematic liquid crystal, evanescent waves are efficiently shifted back into the observation window. The visualized propagation of power spectra in k-space also proves this point. The resolution has an improvement about 3.2 times higher than the linear case, showing potentials in various imaging areas, such as biological tissues imaging and label-free chemical sensing.
Analysis of the encryption penalty in a QAM-based quantum noise stream dcipher
Authors: Li Yuang , Li Yajie , Zhu Kongni , Wang Wei , Zhao Yongli , Zhang Jie
Published: May 2023

Quantum noise stream cipher based on quadrature-amplitude-modulation (QAM/QNSC) is a kind of physical layer encryption technology. However, the additional encryption penalty will significantly affect the practical deployment of QNSC, especially in the high capacity and long-haul transmission system. With our research, the encryption process of QAM/QNSC degrades the transmission performance of plaintext information. In this paper, we quantitatively analyze the encryption penalty of QAM/QNSC based on the proposed concept of effective minimum Euclidean distance. We calculate the theoretical signal-to-noise ratio sensitivity and encryption penalty of QAM/QNSC signals. A modified feedforward pilot-aided two-stage carrier phase recovery scheme is used to reduce the effect of laser phase noise and the encryption penalty. Experimental results achieve single-channel 205.9 Gbit/s 640km transmission with single carrier polarization-diversity-multiplexing 16-QAM/QNSC signal.
Creating multiple ultra-long longitudinal magnetization textures by strongly focusing azimuthally polarized circular Airy vortex beams
Authors: Nie Zhongquan , Ning Zibo , Liu Xiaofei , Zhang Yu , Wang Hengjing , Cao Ensi , Yan Weichao
Published: May 2023

We come up with a simple feasible scheme for the creation of multiple ultra-long longitudinal magnetization textures. This is realized by directly strongly focusing azimuthally polarized circular Airy vortex beams onto an isotropic magneto-optical medium based on the vectorial diffraction theory and the inverse Faraday effect. It is found that, by jointly tuning the intrinsic parameters (i. e. the radius of main ring, the scaling factor, and the exponential decay factor) of the incoming Airy beams and the topological charges of the optical vortices, we are able to garner not only super-resolved scalable magnetization needles as usual, but also steerable magnetization oscillations and nested magnetization tubes with opposite polarities for the first time. These exotic magnetic behaviors depend on the extended interplay between the polarization singularity of multi-ring structured vectorial light fields and the additional vortex phase. The findings demonstrated are of great interest in opto-magnetism and emerging classical or quantum opto-magnetic applications.
Theoretical study of Ag and Au triple core-shell spherical plasmonic nanoparticles in ultra-thin film perovskite solar cells
Authors: Jangjoy Abolfazl , Matloub Samiye
Published: May 2023

This work demonstrates the enhancement of the power conversion efficiency of thin film organic-inorganic halide perovskites solar cells by embedding triple-core-shell spherical plasmonic nanoparticles into the absorber layer. A dielectric-metal-dielectric nanoparticle can be substituted for embedded metallic nanoparticles in the absorbing layer to modify their chemical and thermal stability. By solving Maxwell's equations with the three-dimensional finite difference time domain method, the proposed high-efficiency perovskite solar cell has been optically simulated. Additionally, the electrical parameters have been determined through numerical simulations of coupled Poisson and continuity equations. Based on electro-optical simulation results, the short-circuit current density of the proposed perovskite solar cell with triple core-shell nanoparticles consisting of dielectric-gold-dielectric and dielectric-silver-dielectric nanoparticles has been enhanced by approximately 25% and 29%, respectively, as compared to a perovskite solar cell without nanoparticles. By contrast, for pure gold and silver nanoparticles, the generated short-circuit current density increased by nearly 9% and 12%, respectively. Furthermore, in the optimal case of the perovskite solar cell the open-circuit voltage, the short-circuit current density, the fill factor, and the power conversion efficiency have been achieved at 1.06 V, 25 mAcm-2, 0.872, and 23.00%, respectively. Last but not least, lead toxicity has been reduced due to the ultra-thin perovskite absorber layer, and this study provides a detailed roadmap for the use of low-cost triple core-shell nanoparticles for efficient ultra-thin-film perovskite solar cells.
Diffraction model-driven neural network trained using hybrid domain loss for real-time and high-quality computer-generated holography
Authors: Zheng Huadong , Peng Junchang , Wang Zhen , Shui Xinghua , Yu Yingjie , Xia Xinxing
Published: May 2023

Learning-based computer-generated holography (CGH) has demonstrated great potential in enabling real-time, high-quality holographic displays. However, most existing learning-based algorithms still struggle to produce high-quality holograms, due to the difficulty of convolutional neural networks (CNNs) in learning cross-domain tasks. Here, we present a diffraction model-driven neural network (Res-Holo) using hybrid domain loss for phase-only hologram (POH) generation. Res-Holo utilizes the weights of the pretrained ResNet34 as the initialization during the encoder stage of the initial phase prediction network to extract more generic features and also to help prevent overfitting. Also, frequency domain loss is added to further constrain the information that the spatial domain loss is insensitive. The peak signal-to-noise ratio (PSNR) of the reconstructed image is improved by 6.05 dB using hybrid domain loss compared to using spatial domain loss alone. Simulation results show that the proposed Res-Holo can generate high-fidelity 2 K resolution POHs with an average PSNR of 32.88 dB at 0.014 seconds/frame on the DIV2K validation set. Both monochrome and full-color optical experiments show that the proposed method can effectively improve the quality of reproduced images and suppress image artifacts.
High-precision micro-displacement sensing based on an optical filter and optoelectronic oscillators
Authors: Luo Hao , Yu Jinlong , Wang Ju , Ma Chuang , Han Xu , Su Xuemin
Published: May 2023

High-precision micro-displacement sensing based on an optical filter and optoelectronic oscillators (OEOs) is proposed and experimentally demonstrated. In this scheme, an optical filter is utilized to separate the carriers of the measurement and reference OEO loops. Through the optical filter, the common path structure can be consequently achieved. The two OEO loops share all optical/electrical components, except for the micro-displacement to be measured. Measurement and reference OEOs are alternately oscillated by using a magneto-optic switch. Therefore, self-calibration is achieved without additional cavity length control circuits, greatly simplifying the system. A theoretical analysis of the system is developed, and this analysis is then demonstrated with experiments. Regarding the micro-displacement measurements, we achieved a sensitivity of 312.058 kHz/mm and a measurement resolution of 356 pm. The measurement precision is less than 130 nm over a measurement range of 19 mm.
Machine learning phase modulation of liquid crystal devices for three-dimensional display
Authors: Chen Qian , Zhang Yumeng , Lu Jiangang
Published: May 2023

A machine learning phase modulation scheme based on convolutional neural networks (CNN) and recurrent neural network (RNN) is proposed to carry out the regression task of liquid crystal (LC) device electric field prediction for the 2D/3D switchable display. The hybrid neural network is built and trained based on the illuminance distribution under three-dimensional (3D) display. Compared with manual phase modulation, the modulation method using a hybrid neural network can achieve higher optical efficiency and lower crosstalk in the 3D display. The validity of the proposed method is confirmed through simulations and optical experiments.
Scanning-based compressive hyperspectral imaging via spectral-coded illumination
Authors: Liu Rui , Xiao Ying , Wang Zhongyuan , Ma Jiayi , Tian Xin
Published: May 2023

In this Letter, we present a novel, to the best of our knowledge, scanning-based compressive hyperspectral imaging method via spectral-coded illumination. We achieve efficient and flexible spectral modulation by spectral coding of a dispersive light source while spatial information is obtained by point-wise scanning, which can be applied to optical scanning imaging systems such as lidar. In addition, we propose a new tensor-based joint hyperspectral image reconstruction algorithm that considers spectral correlation and spatial self-similarity to recover three-dimensional hyperspectral data from compressive sampled data. Both simulated and real experiments show that our method has superior performance in visual quality and quantitative analysis.
Dynamic distributed optical fiber sensing based on simultaneous measurement of Brillouin gain and loss spectra with frequency-agile technique
Authors: Zhou Dengwang , Li Pengduo , Ba Dexin , Hasi Wuliji , Dong Yongkang
Published: May 2023

To simplify the experimental equipment and improve the signal-to-noise ratio (SNR) of the traditional Brillouin optical time-domain analysis (BOTDA) system, we propose a scheme using the frequency-agile technique to measure Brillouin gain and loss spectra simultaneously. The pump wave is modulated into the double-sideband frequency-agile pump pulse train (DSFA-PPT), and the continuous probe wave is up-shifted by a fixed frequency value. With the frequency-scanning of DSFA-PPT, pump pulses at the −1st-order sideband and the +1st-order sideband interact with the continuous probe wave via stimulated Brillouin scattering, respectively. Therefore, the Brillouin loss and gain spectra are generated simultaneously in one frequency-agile cycle. Their difference relates to a synthetic Brillouin spectrum with a 3.65-dB SNR improvement for a 20-ns pump pulse. This work simplifies the experimental device, and no optical filter is needed. Static and dynamic measurements are performed in the experiment.
Tunable sum-frequency generation in modal phase-matched thin film lithium niobate rib waveguides
Authors: Du Haoyang , Zhang Xiuquan , Wang Lei , Jia Yuechen , Chen Feng
Published: May 2023

In this work, we report a highly efficient and tunable on-chip sum-frequency generation (SFG) on a thin-film lithium niobate platform via modal phase matching (e + e→e). It provides on-chip SFG a solution with both high efficiency and poling-free by using the highest nonlinear coefficient d33 instead of d31. The on-chip conversion efficiency of SFG is approximately 2143%W−1 with a full width at half maximum (FWHM) of 4.4 nm in a 3-mm-long waveguide. It can find applications in chip-scale quantum optical information processing and thin-film lithium niobate based optical nonreciprocity devices.
Sub-Hz relative linewidths from an interferometrically stabilized mid-infrared frequency comb
Authors: Laumer Dominic , Salman Sarper , Ma Yuxuan , Zawilski Kevin T. , Schunemann Peter G. , Seidel Marcus , Heyl Christoph M. , Hartl Ingmar
Published: May 2023

Frequency combs present a unique tool for high-precision and rapid molecular spectroscopy. Difference frequency generation (DFG) of near-infrared sources is a common approach to generate passively stabilized mid-infrared combs. However, only little attention has been paid so far to precisely measure the coherence properties of such sources. Here, we investigate these using a Raman-soliton based DFG source driven by an Yb:fiber frequency comb. A heterodyne beat between the second harmonic of the phase-locked DFG comb near 4 µm and a 2 µm Tm:fiber frequency comb locked to the same optical reference is performed. Using this method, we measure the relative phase noise power spectral density of both combs. This results in a sub-Hz relative linewidth between the DFG comb and the Tm:fiber comb. We also introduce a new pump/seed delay locking mechanism based on interferometry for long-term stable intensity noise suppression.
Compact topological polarization beam splitter based on all-dielectric fishnet photonic crystals
Authors: Su Ya , Qin Meibao , Ouyang Mingyu , Lei Linlin , He Lingjuan , Wang Tongbiao , Yu Tianbao
Published: May 2023

Conventional polarization beam splitters (PBSs) suffer energy loss and signal distortion due to backscattering caused by disturbances. Topological photonic crystals provide backscattering immunity and anti-disturbance robustness transmission owing to the topological edge states. Here, we put forward a kind of dual-polarization air hole-type fishnet valley photonic crystal with a common bandgap (CBG). The Dirac points at the K point formed by different neighboring bands for transverse magnetic and transverse electric polarizations are drawn closer via changing the filling ratio of the scatterer. Then the CBG is constructed by lifting the Dirac cones for dual polarizations within a same frequency range. We further design a topological PBS using the proposed CBG via changing the effective refractive index at the interfaces which guide polarization-dependent edge modes. Based on these tunable edge states, the designed topological PBS (TPBS) achieves efficient polarization separation and is robust against sharp bends and defects, verified by simulation results. The TPBS’s footprint is approximately 22.4 × 15.2 μm2, allowing high-density on-chip integration. Our work has potential application in photonic integrated circuits and optical communication systems.
Coordinated-security based on probabilistic shaping and encryption in MMW-RoF system
Authors: Xiao Yaoqiang , Wang Sitao , Wang Zhiyi , Jiang Linrong , He Jing
Published: May 2023

A coordinated-security probabilistic shaping (PS) physical layer encryption scheme is proposed for a W-band millimeter-wave radio-over-fiber (MMW-RoF) system. This scheme mainly includes substituting encryption, coordinated encrypted PS, and unequal length grouping scrambling, which can realize the coordination between PS and chaotic encryption. The key space of the proposed scheme is 10103, which can effectively prevent against brute force cracking and chosen-plaintext attacks. The encrypted orthogonal frequency division multiplexing (OFDM) signal is successfully transmitted over 50-km standard single-mode fiber (SSMF) and a 5-m wireless channel. The results show that the proposed scheme achieves 0.8-dB received optical power gain at a bit error rate (BER) of 10−3 compared with a traditional OFDM signal. The superiority of the proposed scheme in security performance and BER performance has been verified.
Achieving ns-level pulsed operation of up to 6.27 W with a 1.55-µm BH-DFB laser for LiDAR applications
Authors: Liu Te-Hua , Cheng Hao-Tien , Wu Jau-Yang , Wu Chao-Hsin
Published: May 2023

In this Letter, we present a highly efficient 1.55-µm buried
heterostructure distributed feedback (BH-DFB) laser diode. The
optimized epitaxial structure resulted in a threshold current of 12 mA
and a differential slope efficiency of 0.433 W/A. The laser exhibited
stable single longitudinal mode characteristics in both high current
injection and broad temperature range testing. Additionally, the
ns-level pulsed operation characteristics of the BH-DFB laser were
verified, achieving a pulse peak power of 6.27 W with a pulse optical
width of 20.4 ns. The watt-level pulse optical power was achieved with
a single active region. With its eye-safe wavelength, high operating
efficiency, stable single-mode spectral characteristics, and high
pulse optical power, the 1.55-µm BH-DFB laser is a promising light
source for LiDAR systems.
Physical properties of hydrogen bonded nematic liquid crystals and electro-optical properties in terahertz waves [Invited]
Authors: Yamaguchi Rumiko
Published: May 2023

4-m-alkyl cyclohexane carboxylic acids and 4-n-alkylbenzoic acids were mixed to form hydrogen bonded liquid crystals (HBLCs), which exhibited a nematic phase at room temperature. Dielectric constants and three elastic constants of HBLC mixtures were investigated. Benzoic acid derivatives with some polar groups were added to the HBLC and the dielectric anisotropy was successfully enhanced. Considering the absorption loss of HBLCs in the terahertz wave region, the electro-optical properties of the homogeneous and twisted nematic cells were numerically evaluated using measured physical properties, and the transmitted polarization state was compared with that of conventional nematic LCs.
Evolution, persistence, and host adaption of a gonococcal AMR plasmid that emerged in the pre-antibiotic era
Authors: Yee Wearn-Xin , Yasir Muhammad , Turner A. Keith , Baker David J. , Cehovin Ana , Tang Christoph M.
Published: May 2023

Plasmids are diverse extrachromosomal elements significantly that contribute to interspecies dissemination of antimicrobial resistance (AMR) genes. However, within clinically important bacteria, plasmids can exhibit unexpected narrow host ranges, a phenomenon that has scarcely been examined. Here we show that pConj is largely restricted to the human-specific pathogen, Neisseria gonorrhoeae. pConj can confer tetracycline resistance and is central to the dissemination of other AMR plasmids. We tracked pConj evolution from the pre-antibiotic era 80 years ago to the modern day and demonstrate that, aside from limited gene acquisition and loss events, pConj is remarkably conserved. Notably, pConj has remained prevalent in gonococcal populations despite cessation of tetracycline use, thereby demonstrating pConj adaptation to its host. Equally, pConj imposes no measurable fitness costs and is stably inherited by the gonococcus. Its maintenance depends on the co-operative activity of plasmid-encoded Toxin:Antitoxin (TA) and partitioning systems rather than host factors. An orphan VapD toxin encoded on pConj forms a split TA with antitoxins expressed from an ancestral co-resident plasmid or a horizontally-acquired chromosomal island, potentially explaining pConj’s limited distribution. Finally, ciprofloxacin can induce loss of this highly stable plasmid, reflecting epidemiological evidence of transient reduction in pConj prevalence when fluoroquinolones were introduced to treat gonorrhoea.
Regulation by cyclic di-GMP attenuates dynamics and enhances robustness of bimodal curli gene activation in Escherichia coli
Authors: Lamprecht Olga , Ratnikava Maryia , Jacek Paulina , Kaganovitch Eugen , Buettner Nina , Fritz Kirstin , Biazruchka Ina , Köhler Robin , Pietsch Julian , Sourjik Victor
Published: May 2023

Curli amyloid fibers are a major constituent of the extracellular biofilm matrix formed by bacteria of the Enterobacteriaceae family. Within Escherichia coli biofilms, curli gene expression is limited to a subpopulation of bacteria, leading to heterogeneity of extracellular matrix synthesis. Here we show that bimodal activation of curli gene expression also occurs in well-mixed planktonic cultures of E. coli, resulting in all-or-none stochastic differentiation into distinct subpopulations of curli-positive and curli-negative cells at the entry into the stationary phase of growth. Stochastic curli activation in individual E. coli cells could further be observed during continuous growth in a conditioned medium in a microfluidic device, which further revealed that the curli-positive state is only metastable. In agreement with previous reports, regulation of curli gene expression by the second messenger c-di-GMP via two pairs of diguanylate cyclase and phosphodiesterase enzymes, DgcE/PdeH and DgcM/PdeR, modulates the fraction of curli-positive cells. Unexpectedly, removal of this regulatory network does not abolish the bimodality of curli gene expression, although it affects dynamics of activation and increases heterogeneity of expression levels among individual cells. Moreover, the fraction of curli-positive cells within an E. coli population shows stronger dependence on growth conditions in the absence of regulation by DgcE/PdeH and DgcM/PdeR pairs. We thus conclude that, while not required for the emergence of bimodal curli gene expression in E. coli, this c-di-GMP regulatory network attenuates the frequency and dynamics of gene activation and increases its robustness to cellular heterogeneity and environmental variation.
Rab8, Rab11, and Rab35 coordinate lumen and cilia formation during zebrafish left-right organizer development
Authors: Aljiboury Abrar A. , Ingram Eric , Krishnan Nikhila , Ononiwu Favour , Pal Debadrita , Manikas Julie , Taveras Christopher , Hall Nicole A. , Da Silva Jonah , Freshour Judy , Hehnly Heidi
Published: May 2023

An essential process during Danio rerio’s left-right organizer (Kupffer’s Vesicle, KV) formation is the formation of a motile cilium by developing KV cells which extends into the KV lumen. Beating of motile cilia within the KV lumen directs fluid flow to establish the embryo’s left-right axis. However, the timepoint at which KV cells start to form cilia and how cilia formation is coordinated with KV lumen formation have not been examined. We identified that nascent KV cells form cilia at their centrosomes at random intracellular positions that then move towards a forming apical membrane containing cystic fibrosis transmembrane conductance regulator (CFTR). Using optogenetic clustering approaches, we found that Rab35 positive membranes recruit Rab11 to modulate CFTR delivery to the apical membrane, which is required for lumen opening, and subsequent cilia extension into the lumen. Once the intracellular cilia reach the CFTR positive apical membrane, Arl13b-positive cilia extend and elongate in a Rab8 dependent manner into the forming lumen once the lumen reaches an area of 300 μm2. These studies demonstrate the need to acutely coordinate Rab8, Rab11, and Rab35-mediated membrane trafficking events to ensure appropriate timing in lumen and cilia formation during KV development.
MCMCINLA estimation of varying coefficient spatial lag model—A study of China’s economic development in the context of population aging
Authors: Teng Jiaqi , Ding Shuzhen , Zhang Huiguo , Hu Xijian
Published: May 2023

The dominant spatial econometric model in spatial econometrics is the parametric form, while in the realistic context, the variables often do not satisfy the assumption of linearity and have nonlinear relationships with each other. In this paper, we introduce nonparametric terms into spatial econometric models and propose the MCMCINLA estimation method for varying coefficient spatial lag models. The empirical analysis is conducted with the socioeconomic data of mainland China from 2015 to 2020 to discuss the influencing factors and spatial and temporal distribution characteristics of China’s economic development under the classical spatial lag model and the varying coefficient spatial lag model with population aging as a special covariate, respectively. The results show that with the gradual aging of the population, foreign trade will inhibit the development of regional economy to a certain extent, while urbanization process, resident income, real estate development and high-tech development will have a driving effect on economic growth, and high-tech development has the strongest mobilization on regional economic development. Compared with the classical spatial lag model, the varying coefficient spatial lag model can more fully exploit the information of variables in a more realistic context and derive the variable evolution process.
Environmental and climate variability drive population size of annual penaeid shrimp in a large lagoonal estuary
Authors: Schlenker Lela S. , Stewart Chris , Rock Jason , Heck Nadine , Morley James W.
Published: May 2023

Species with short life spans frequently show a close relationship between population abundance and environmental variation making these organisms potential indicator species of climatic variability. White (Penaeus setiferus), brown (P.aztecus), and pink (P.duorarum) penaeid shrimp typically have an annual life history and are of enormous ecological, cultural, and economic value to the southeastern United States and Gulf of Mexico. Within North Carolina, all three species rely on the Pamlico Sound, a large estuarine system that straddles Cape Hatteras, one of the most significant climate and biogeographic breaks in the world, as a nursery area. These characteristics make penaeid species within the Pamlico Sound a critical species-habitat complex for assessing climate impacts on fisheries. However, a comprehensive analysis of the influence of the environmental conditions that influence penaeid shrimp populations has been lacking in North Carolina. In this study, we used more than 30 years of data from two fishery-independent trawl surveys in the Pamlico Sound to examine the spatial distribution and abundance of adult brown, white, and pink shrimp and the environmental drivers associated with adult shrimp abundance and juvenile brown shrimp recruitment using numerical models. Brown shrimp recruitment models demonstrate that years with higher temperature, salinity, offshore windstress, and North Atlantic Oscillation phase predict increased abundance of juveniles. Additionally, models predicting adult brown, white, and pink shrimp abundance illustrate the importance of winter temperatures, windstress, salinity, the North Atlantic Oscillation index, and the abundance of spawning adult populations from the previous year on shrimp abundance. Our findings show a high degree of variability in shrimp abundance is explained by climate and environmental variation and indicate the importance of understanding these relationships in order to predict the impact of climate variability within ecosystems and develop climate-based adaptive management strategies for marine populations.
The role of cognitive rehabilitation in people with type 2 diabetes: A study protocol for a randomized controlled trial
Authors: Cuevas Heather , Stuifbergen Alexa K. , Hilsabeck Robin C. , Sales Adam , Wood Shenell , Kim Jeeyeon
Published: May 2023

Today, the prevalence of cognitive dysfunction and the prevalence of diabetes are increasing. Research shows that diabetes increases cognitive impairment risk, and cognitive impairment makes diabetes self-management more challenging. Diabetes self-management, essential to good glycemic control, requires patients to assimilate knowledge about their complex disease and to engage in activities such as glucose self-monitoring and the management of their medications. To test a comprehensive cognitive rehabilitation intervention—the Memory, Attention, and Problem-Solving Skills for Persons with Diabetes (MAPSS-DM) program. Our central hypothesis is that participants who take part in the MAPSS-DM intervention will have improved memory and executive function, increased use of compensatory cognitive skills, and improved self-management. We will also explore the role of glucose variability in those changes. This is a randomized controlled trial. Sixty-six participants with cognitive concerns and type 2 diabetes will be assigned to either the full MAPSS-DM intervention or an active control. Participants will use continuous glucose monitoring pre- and post-intervention to identify changes in glycemic variability. All participants will also be evaluated systematically via questionnaires and neuropsychological tests at three timepoints: baseline, immediately post-intervention, and 3 months post-intervention. This study will fill an important gap by addressing cognitive function in the management of diabetes. Diabetes is related to accelerated cognitive aging, cognitive deficits are related to poorer self-management, and improvements in cognitive performance as a result of cognitive rehabilitation can translate into improved performance in everyday life and, potentially, diabetes self-management. The results of the proposed study will therefore potentially inform strategies to support cognitive function and diabetes self-management, as well as offer new mechanistic insights into cognitive function through the use of continuous glucose monitoring.

Trial registration: This study has been registered at ClinicalTrials.gov (NCT04831775).
Diffusion characteristics classification framework for identification of diffusion source in complex networks
Authors: Yang Fan , Liu Jingxian , Zhang Ruisheng , Yao Yabing
Published: May 2023

The diffusion phenomena taking place in complex networks are usually modelled as diffusion process, such as the diffusion of diseases, rumors and viruses. Identification of diffusion source is crucial for developing strategies to control these harmful diffusion processes. At present, accurately identifying the diffusion source is still an opening challenge. In this paper, we define a kind of diffusion characteristics that is composed of the diffusion direction and time information of observers, and propose a neural networks based diffusion characteristics classification framework (NN-DCCF) to identify the source. The NN-DCCF contains three stages. First, the diffusion characteristics are utilized to construct network snapshot feature. Then, a graph LSTM auto-encoder is proposed to convert the network snapshot feature into low-dimension representation vectors. Further, a source classification neural network is proposed to identify the diffusion source by classifying the representation vectors. With NN-DCCF, the identification of diffusion source is converted into a classification problem. Experiments are performed on a series of synthetic and real networks. The results show that the NN-DCCF is feasible and effective in accurately identifying the diffusion source.