bluuebunny/crossref_metadata_2025 huggingface dataset:
Small Molecule-mediated Insulin Hypersecretion Induces Transient ER Stress Response and Loss of Beta Cell Function
Authors: Rodrigues-dos-Santos Karina , Roy Gitanjali , Binns Derk D , Grzemska Magdalena G , Barella Luiz F , Armoo Fiona , McCoy Melissa K , Huynh Andy V , Yang Jonathan Z , Posner Bruce A , Cobb Melanie H , Kalwat Michael A
Published: June 2022

Pancreatic islet beta cells require a fine-tuned endoplasmic reticulum (ER) stress response for normal function; abnormal ER stress contributes to diabetes pathogenesis. Here, we identified a small molecule, SW016789, with time-dependent effects on beta cell ER stress and function. Acute treatment with SW016789 potentiated nutrient-induced calcium influx and insulin secretion, while chronic exposure to SW016789 transiently induced ER stress and shut down secretory function in a reversible manner. Distinct from the effects of thapsigargin, SW016789 did not affect beta cell viability or apoptosis, potentially due to a rapid induction of adaptive genes, weak signaling through the eIF2α kinase PERK, and lack of oxidative stress gene Txnip induction. We determined that SW016789 acted upstream of voltage-dependent calcium channels (VDCCs) and potentiated nutrient- but not KCl-stimulated calcium influx. Measurements of metabolomics, oxygen consumption rate, and G protein-coupled receptor signaling did not explain the potentiating effects of SW016789. In chemical cotreatment experiments, we discovered synergy between SW016789 and activators of protein kinase C and VDCCs, suggesting involvement of these pathways in the mechanism of action. Finally, chronically elevated calcium influx was required for the inhibitory impact of SW016789, as blockade of VDCCs protected human islets and MIN6 beta cells from hypersecretion-induced dysfunction. We conclude that beta cells undergoing this type of pharmacological hypersecretion have the capacity to suppress their function to mitigate ER stress and avoid apoptosis. These results have the potential to uncover beta cell ER stress mitigation factors and add support to beta cell rest strategies to preserve function.
Cardiac mitochondrial energetics of the Australasian red spiny lobster, Jasus edwardsii, when exposed to isoeugenol within the commercial anaesthetic AQUI-S
Authors: Robertson James , Jeffs Andrew , Hedges Christopher , Hickey Anthony J. R.
Published: June 2022

The anaesthetic isoeugenol has been used as metabolic suppressant for commercial transport of live lobsters in order to decrease energy expenditure and improve survival. Given the central role of mitochondria in metabolism and structural similarities of isoeugenol to the mitochondrial electron carrier coenzyme Q, we explored the influence on mitochondrial function of isoeugenol. Mitochondrial function was measured using high-resolution respirometry and saponin-permeabilised heart fibres from the Australasian red spiny lobster, Jasus edwardsii. Relative to vehicle (polysorbate), isoeugenol inhibited respiration supported by complex I (CI) and cytochrome c oxidase (CCO). While complex II (CII), which also reduces coenzyme Q, was largely unaffected by isoeugenol, respiration supported by CII when uncoupled was depressed. Titration of isoeugenol indicates that respiration through CI has a half-maximal inhibitory concentration (IC50) of 2.4±0.1 µmol l−1, and a full-maximal inhibitory concentration (IC100­) of approximately 6.3 µmol l−1. These concentrations are consistent with those used for transport and euthanasia of J. edwardsii and indicate that CI is a possible target of isoeugenol, like many other anaesthetics with quinone-like structures.
Top of the Batch: Interviews and the Match
Authors: Echenique Federico , González Ruy , Wilson Alistair J. , Yariv Leeat
Published: June 2022

Most doctors in the National Resident Matching Program (NRMP) match with one of their most preferred internship programs. However, surveys indicate doctors’ preferences are similar, suggesting a puzzle: how can so many doctors match with their top choices when positions are scarce? We provide one possible explanation. We show that the patterns in the NRMP data may be an artifact of the interview process that precedes the match. Our study highlights the importance of understanding market interactions occurring before and after a matching clearinghouse. It casts doubts on analyses of clearinghouses that take reported preferences at face value. (JEL C78, I11, I18, J44)
Evaluation of interactions of silibinin with the proteins ALS3 and SAP5 against Candida albicans
Authors: Da Silva Cecília Rocha , Damacieira Moura Francisca Lariza , Almeida Alves Filho André Luis , Campos Rosana De Sousa , Cabral Vitória Pessoa de Farias , Valente Sá Lívia Gurgel do Amaral , Da Silva Anderson Ramos , Silva Jacilene , Cardoso Viana Gomes Akenaton Onassis , Barbosa Letícia Bernardo , Dos Santos Hélcio Silva , Marinho Emmanuel Silva , Cavalcanti Bruno Coelho , Nobre Júnior Hélio Vitoriano , Neto João Batista De Andrade
Published: June 2022

Objective: to evaluate the molecular interaction of silibinin with the targets ALS3 and SAP5. Methodology: Molecular docking protocols were conducted to analyze the binding interaction of silibinin with ALS3 and SAP5. Results: Eleven interactions of ALS3 with silibinin and four with fluconazole were found, while six interactions were observed of SAP5 with silibinin and four with fluconazole. Conclusion: Molecular docking between silibinin and ALS3 identified important interactions, but no significant interactions were observed with SAP5, even though silibinin can exhibit affinity and interactions with other SAP5 sites.
Wasted mask collection robot
Authors: Zhao Yihan , Wang Yuecheng , Jiang Hong
Published: June 2022

With the spread of major respiratory infectious diseases such as the new coronavirus pneumonia on a large scale worldwide, various countries and regions have taken medical supplies such as disposable medical masks (DMMs, mainly composed of a large variety of polymer material polypropylene PP). The demand is constantly rising. A large number of discarded masks are mixed in the streets and alleys, and the recycling process is extremely risky. In this era, it is particularly important to realize manual remote control of the collection of discarded masks. The waste mask collection robot mentioned in this article adopts a modular design method and carries out the system design, control system design, and hardware structure design for each part of the waste mask collection. In terms of the hardware system, a detailed analysis has been made on the chip model and the specifications of each application device and a reasonable design have been carried out. The design requirements of various parts are introduced, and their structure and function in the device are described in detail. Related hardware circuits are designed, such as the manipulator motor drive circuit and its control circuit. In terms of the software system, the driver program, the function program of the host computer, and the STM32 single-chip microcomputer, such as PWM motor driver and serial port communication, are designed. In terms of control system design, based on the Robot-link Wi-Fi wireless data transmission module, a set of information interaction codes between the host computer and the STM32 single-chip microcomputer is designed, which can realize ultra-low delay control. The PWM motor drive and serial communication were tested for the function. After the program was burned, the expected function was completed, and the actual product was finally assembled and tested to achieve the expected function.
Presenteeism and associated factors among railway train drivers
Authors: Awaad Asmaa El-Sayed , El-Bestar Sohair , El-Gilany Abdel-Hady , Al-Wehedy Adel , El-Hadidy Samah Saleh
Published: June 2022

Background: Presenteeism is an emerging work-related health problem among train drivers. It is more serious than absenteeism, as it accounts for higher productivity losses over the long term and may increase the risk of occupational accidents. Train drivers have high rates of mental and physical health conditions that may put them at high risk of presenteeism.

Methods: A comparative cross-sectional study was conducted on 100 train drivers working in Mansoura railway station and 100 administrative employees working in the Faculty of Medicine, Mansoura university as a comparison group to estimate the prevalence of presenteeism and its associated factors among train drivers working in Mansoura railway station, Egypt. A questionnaire was used to collect socio-demographic, occupational and medical data. The Kessler Psychological Distress Scale (K10) was used to measure non-specific psychological distress. The Stanford Presenteeism Scale (SPS-6) was used to assess productivity loss related to sickness presenteeism.

Results: The prevalence of presenteeism was significantly higher among train drivers (76%) compared to the comparison group (31%). All participants (100%) with psychological distress reported presenteeism. Being a train driver (adjusted odds ratio [AOR]=5.4) and having hypertension (AOR=4.03) are independent predictors for presenteeism.

Conclusions: The prevalence of presenteeism and its associated risk factors were significantly higher among train drivers than the comparison group. There is an urgent need for the railway industry to understand the factors that may contribute to presenteeism.
The role of technology capability in supporting firm performance in the high-tech manufacturing industry
Authors: Noerlina Noerlina , Nugroho Christie , Mursitama Tirta Nugraha , Simatupang Boto , Bandur Agustinus
Published: June 2022

Background: Technology has influenced many aspects of life, particularly in the digital era of today. Companies that are closely related to technology are also challenged to keep innovating to stay competitive in the market, especially the higher their technology intensity their products and services are related. This study focuses on examining the technology capability of high-tech manufacturing firms in Indonesia. According to the International Standard Industrial Classification, high-tech manufacturing firms are firms that manufacture computer, electronic, and optical products. The aim of this study is to identify the role of technology capability that influences a firm’s performance and identify whether the value chain mediates the relationship between technology capability to firm performance.

Methods: The method used in this study is descriptive quantitative analysis, using multi-linear regression and path analysis to test the hypothesis. The data used in this study is secondary data that came from Badan Pusat Statistik (BPS), Indonesia's official statistics agency. The survey data used in this study comes from Indonesia's annual survey of manufacturing firms in 2017.

Result: Technology capability and value chain have significant effects on firm performance. Nonetheless, the value chain as an intervening variable has no significant effect on firm performance. In other words, with or without technology utilization of the value chain, both produce similar results.

Conclusion: Firms in the high-tech manufacturing industry are expected to have sufficient knowledge and capability in utilizing their technology resources to ensure the firm's long-term viability and to enable them to continuously create innovations, which leads to improved firm performance and thus to their competitive market survival. By identifying the effect of the value chain as an intervening variable and identifying the difference between direct and indirect effects, this study also adds to previous research on the effects of technology capability and value chain on firm performance.
Introduction: Reflecting on Ferdinand de Saussure’s intellectual legacy in the modern context of the development of semiotics and history and epistemology of ideas
Authors: Velmezova Ekaterina , Fadda Emanuele
Published: June 2022

Introduction: Reflecting on Ferdinand de Saussure’s intellectual legacy in the modern context of the development of semiotics and history and epistemology of ideas
Impact of the Covid-19 Pandemic Outbreak on Panic Buying Behavior in the FMCG Sector
Authors: Thakur Vesheshta , Kiran Prabha
Published: June 2022

There is no doubt that a very challenging market climate has been created by the crisis triggered by the global coronavirus pandemic. Many firms have faced partial and even extended stoppages, with employees facing financial uncertainties and concerns for months. Consumer behavior has been compelled involuntarily to alter their habit of consumption in a large scale. Distress over the delivery of the commodities has led many individuals to panic purchasing of vital materials in bulk quantities. The view of a long-term recession and financial instability will have a notable effect on customer expectations, outlook and actions.

The current research attempts to analyze and quantify customer preferences, emotions and consumer behavior during the coronavirus crisis. The report also reflects on the transition in eating patterns after the outbreak of COVID-19. It will also examine and present the variations in eating habits and behavior across different genders and ages.
Çocuklarda Metamfetamin İntoksikasyonu: Tek Merkez Deneyimi
Authors: YİĞİT Metin , GÖKDÖL Muhammed Yasin , KALAYCI Furkan , AKCA ÇAĞLAR Ayla , AKCAN YILDIZ Leman , KURT Funda , AKÇA Halise
Published: June 2022

Amaç: Yasadışı uyuşturucu maddeler, özellikle de metamfetamin, dünyada olduğu gibi Türkiye'de de ergenler arasında giderek daha popüler hale gelmektedir. Türkiye'de bu amaçla yapılan çalışmaların çoğu anket çalışmalarıdır. Çalışmamız ise hastanemize başvuran ve metamfetamin intoksikasyonu saptanan hastaların klinik özelliklerini ve laboratuvar parametrelerini değerlendirmeyi amaçlamıştır.
Gereç ve Yöntemler: Ağustos 2019-Aralık 2021 tarihleri arasında Ankara Şehir Hastanesi Çocuk Acil Servisi'ne başvuran ve idrar toksik madde taramasında metamfetamin pozitif saptanan 18 yaş altı hastalar çalışmaya dahil edildi ve verileri retrospektif olarak değerlendirildi.
Bulgular: Çalışmamızda metamfetamin intoksikasyonu saptanan 10 hastayı inceledik. Ortalama yaş 16.3 ± 0.94 (14-17) idi ve hastaların %80'i erkekti. Sekiz hasta başvuru sırasında madde kullanımını gizledi. Başvuru anında en sık kardiyovasküler, nörolojik ve gastrointestinal sistem semptomları görüldü. Dört hastada eşzamanlı alkol kullanımı, bir hastada çoklu uyuşturucu kullanımı saptandı. Laboratuar testlerinde önemli bir patoloji gözlenmedi. Karın ağrısı olan bir hastada mide perforasyonu, göğüs ağrısı olan bir hastada pnömomediastinum tespit edildi.
Sonuç: Metamfetamin intoksikasyonunun spesifik klinik ve laboratuvar göstergeleri yoktur ve olası bir nedenin hastanın klinik bulgularını açıklayamadığı tüm durumlarda madde kötüye kullanımı düşünülmelidir. Alkol kullanan çocuklarda madde kullanımı sorgulanmalı, çoklu madde kullanımı açısından dikkatli olunmalı, buna göre hasta takip ve rehabilitasyon planları yapılmalıdır.
Critical thinking and diagnostic reasoning for advanced clinical practitioners in sexual health
Authors: McPhillips Hazel , Wood Alison F , Smith Joanna
Published: June 2022

This article provides an overview of key areas within sexual health examination, diagnosis and treatment options for advanced clinical practitioners (ACPs) working outside this field of practice, who may not often encounter consultations of a sexual health nature. ACPs require an understanding of appropriate and necessary investigations, alongside specific advice or education they can offer patients. Within a sexual health context especially, the consultation and subsequent steps can be challenging and distressing for the patient, and the ACP must consider their knowledge and experience when caring for a patient in this area. Increasing knowledge and awareness of common conditions and treatments, red flags, and referral processes can allow the ACP to provide reassurance and support to the patient and improve their healthcare experience. Having answers to a patient's questions regarding processes and time frames can strengthen the relationship between the ACP and their patient and help reduce a patient's anxiety and fear of the unknown.
Development of a simulation placement in a pre-registration nursing programme
Authors: Williams Janet , Murphy Mark , Garrow Amanda
Published: June 2022

Background:

A 4-week simulation placement for first-year student nurses using an innovative blended approach was developed and delivered in one university. This was the first tariff-funded simulation placement in the UK for student nurses.

Aims:

To describe how this flexible simulation placement was developed, operated and adapted due to COVID-19 while exploring the student nurses' experiences and preparedness for practice.

Methods:

An anonymous online survey was undertaken and a placement evaluation was completed and compared with traditional clinical placement evaluations by previous students at the same point in their studies.

Results:

Students were as satisfied with the simulation placement as students who had attended real practice placements: 92% of students were satisfied with their simulated placement experience and 92% felt prepared for practice.

Conclusion:

This simulated placement has been an acceptable replacement for traditional practice placements, particularly during the COVID-19 pandemic.
Closed safety system for administration (CSSA): proposal for a new cytotoxic chemotherapy acronym
Authors: Eisenberg Seth
Published: June 2022

Exposure to cytotoxic chemotherapy can result in acute and chronic conditions including nausea, headaches, rashes, miscarriages, infertility and genetic aberrations. Surface contamination can occur during drug administration, and can subsequently spread throughout the healthcare environment. Dermal contact with contaminated surfaces can lead to drug absorption. Closed system drug-transfer devices (CSTDs) were initially developed to protect pharmacists during compounding. Components include a vial adapter to prevent pressurisation leakage and a syringe connector for transferring the drug to the intravenous infusion bag. Membrane-based CSTDs require a Luer adapter for drug administration whereas Luer system-based products do not. Most European nurses are familiar with needleless connectors. Unfortunately, these devices do not provide protection from chemotherapy exposure. To decrease confusion, CytoPrevent, a multi-national, primarily European organisation has proposed the term ‘closed safety system for administration’ (CSSA) for Luer based CSTDs. Along with education, the new term can help promote safety for nurses administering cytotoxic chemotherapy.
Young and early career cancer nurses: sustaining the future of cancer nursing
Authors: Rowell Constance , Maynard Bethany , Ewang Jane
Published: June 2022

Constance Rowell, Bethany Maynard and Jane Ewang, UK Oncology Nursing Society Young and Early Career Cancer Nurse Representatives
‘I no longer feel alone’: meeting the needs of bereaved grandparents through a children's hospice support group
Authors: Tatterton Michael J , Lyon Judith A
Published: June 2022

Background:

Children's hospices provide a range of family-centred care services, including bereavement support. Not all hospices provide specific services for grandparents.

Aim:

To explore how a hospice-based bereavement support group supported grandparents in their grief following the death of a grandchild.

Methods:

Grandparents attending a group were invited to complete an anonymous questionnaire. Questionnaires from eight groups, run between 2015 and 2019 were collated and interpreted to identify themes.

Findings:

A total of 121 grandparents attended the groups; 113 returned the questionnaires (93% response). A total of three superordinate themes were identified: environment and space, being with people who understand, and the opportunity to hear the stories of others. Grandparents valued hearing the stories of others, providing an opportunity to reflect on the experience of others.

Conclusion:

Grandparents felt supported and validated by the group. Facilitated sessions increased coping and resilience of participants, enabling grandparents to support their partner, adult children and surviving grandchildren more effectively.
The IMPACT of COVID-19 on trauma & orthopaedic surgery provides lessons for future communicable disease outbreaks
Authors: Hall Andrew J. , Clement Nick D. , MacLullich Alasdair M. J. , Simpson A. Hamish R. W. , White Tim O. , Duckworth Andrew D.
Published: June 2022

Research into COVID-19 has been rapid in response to the dynamic global situation, which has resulted in heterogeneity of methodology and the communication of information. Adherence to reporting standards would improve the quality of evidence presented in future studies, and may ensure that findings could be interpreted in the context of the wider literature. The COVID-19 pandemic remains a dynamic situation, requiring continued assessment of the disease incidence and monitoring for the emergence of viral variants and their transmissibility, virulence, and susceptibility to vaccine-induced immunity. More work is needed to assess the long-term impact of COVID-19 infection on patients who sustain a hip fracture. The International Multicentre Project Auditing COVID-19 in Trauma & Orthopaedics (IMPACT) formed the largest multicentre collaborative audit conducted in orthopaedics in order to provide an emergency response to a global pandemic, but this was in the context of many vital established audit services being disrupted at an early stage, and it is crucial that these resources are protected during future health crises. Rapid data-sharing between regions should be developed, with wider adoption of the revised 2022 Fragility Fracture Network Minimum Common Data Set for Hip Fracture Audit, and a pragmatic approach to information governance processes in order to facilitate cooperation and meta-audit. This editorial aims to: 1) identify issues related to COVID-19 that require further research; 2) suggest reporting standards for studies of COVID-19 and other communicable diseases; 3) consider the requirement of new risk scores for hip fracture patients; and 4) present the lessons learned from IMPACT in order to inform future collaborative studies.

Cite this article: Bone Joint Res 2022;11(6):342–345.
Cultural challenges facing UK surgeons providing education in low and middle income countries
Authors: Hodgson SP , Abdelrahman M , Jemec B , Lam WL , Muchemwa F , Ahmed T , Tucker SC
Published: June 2022

Surgeons from high income countries such as the UK are well placed to support our surgical colleagues in low and middle income countries by performing educational visits. This paper describes the experience of the British Society for Surgery of the Hand and the British Foundation for International Reconstructive Surgery and Training, which have been supporting educational work delivered by their members since 2010. There have been many lessons learnt, including solving challenges caused by our cultural differences. We outline the challenges and cultural intelligence theory that has helped resolution. These lessons may be of relevance to any surgeons from high income countries undertaking educational work in low and middle income countries.
Changing one's view on stoma formation
Authors: Wheeler Robert
Published: June 2022

Our legal contributor looks at a case in which a decision was made on stoma formation.
Performance of an all-links MIMO-OSTBC mixed underlay cognitive RF/FSO system
Authors: Wang Yi , Zhan Xiaotong , Zhan Zhiwu
Published: June 2022

This paper presents a new model, to the best of our knowledge, of a mixed underlay cognitive radio frequency (RF)/free space optical (FSO) system in which both RF and FSO links consider multiple-input multiple-output (MIMO) orthogonal space-time block coding (OSTBC). In a dual-hop decode-and-forward configuration, the underlay cognitive radio network RF and FSO links experience

κ

−

μ

and

Γ
−
Γ

fading, respectively. For the above system model, a closed expression for the outage probability of the mixed underlay cognitive RF/FSO system with MIMO-OSTBC is derived, and the simulation results are verified using the Monte Carlo method. The results show that considering MIMO-OSTBC in all links of the mixed underlay cognitive RF/FSO system can effectively improve the communication performance of the mixed system and alleviate the degradation in the communication quality caused by the atmospheric turbulence. The communication performance of the MIMO-OSTBC mixed underlay cognitive RF/FSO system is further improved by changing the key parameters, such as peak transmit power, fading parameters, the number of secondary user transmit antennas and relay receive antennas, and relative speed of the primary user.
Video-rate high-resolution single-pixel nonscanning photoacoustic microscopy
Authors: Chen Ningbo , Yu Jia , Liu Liangjian , Xu Zhiqiang , Gao Rongkang , Chen Tao , Song Liang , Zheng Wei , Liu Chengbo
Published: June 2022

Optical-resolution photoacoustic microscopy (OR-PAM) is widely utilized in biomedical applications because of its ability to noninvasively image biological tissues in vivo while providing high-resolution morphological and functional information. However, one drawback of conventional OR-PAM is its imaging speed, which is restricted by the scanning technique employed. To achieve a higher imaging frame rate, we present video-rate high-resolution single-pixel nonscanning photoacoustic microscopy (SPN-PAM), which utilizes Fourier orthogonal basis structured planar illumination to overcome the above-mentioned limitations. A 473 × 473 µm2 imaging field of view (FOV) with 3.73 µm lateral resolution and video-rate imaging of 30 Hz were achieved. In addition, in both in vitro cell and in vivo mouse vascular hemodynamic imaging experiments, high-quality images were obtained at ultralow sampling rates. Thus, the proposed high-resolution SPN-PAM with video-rate imaging speed provides new insights into high-speed PA imaging and could be a powerful tool for rapid biological imaging.
Propagation of a multi-vortex beam: far-field diffraction of a Gaussian beam from a multi-fork phase grating
Authors: Rasouli Saifollah , Gholami Azam , Amiri Pouria , Kotlyar Victor V. , Kovalev Alexey A.
Published: June 2022

In this work, the far-field propagation of multi-vortex beams is investigated. We consider diffraction of a Gaussian wave from a spatial light modulator (SLM) in which a multi-fork grating is implemented on it at the waist plane of the Gaussian wave. In the first-order diffraction pattern a multi-vortex beam is produced, and we consider its evolution under propagation when different multi-fork gratings are implemented on the SLM. We consider two different schemes for the phase singularities of the implemented grating. A topological charge (TC) equal to

l
1

is considered at the center of the grating, and four similar phase singularities all having a TC equal to

l
2

=

l
1

4

(or

l
2

=
−

l
1

4

) are located on the corners of a square where the

l
1

singularity is located on the square center. Some cases with different values of

l
1

, and consequently

l
2

, are investigated. Experimental and simulation results show that if signs of the TCs at the corners and center of the square are the same, the radius of the central singularity on the first-order diffracted beam increases, and it convolves the other singularities. If their signs are opposite, the total TC value equals zero, and at the far-field, the light beam distribution becomes a Gaussian beam. For determining the TCs of the resulting far-field beams, we interfere experimentally and by simulation the resulting far-field beams with a plane wave and count the forked interference fringes. All the results are consistent.
Chaotic self-trapped beams in the nonlocal nonlinear system with the sine-oscillation response
Authors: Zhong Lanhua , Li Xiantao , Guo Qi
Published: June 2022

The propagation of the unstable multipeak solitons in the nonlocal nonlinear system with the sine-oscillation response was examined in this paper. It was found that the beams are self-trapped while possessing the chaotic property under both the conditions of negative Kerr coefficient at strong nonlocality and positive Kerr coefficient at weak nonlocality. The self-trapping is represented by the invariant beam width and spectrum width. The chaotic property, denoted by the positive Lyapunov exponents, corresponds to the phenomenon that the profiles of the intensity change irregularly in the propagation direction. Compared with the known chaoticons, which were found only in the strongly nonlocal nonlinear system with the positively defined attenuating response for the positive Kerr coefficient, these beams have different characteristics in the interaction between beams and distribution of energy.
Efficient multi-step coupling between Si3N4 waveguides and CMOS plasmonic ferroelectric phase shifters in the O-band
Authors: Chatzitheocharis D. , Ketzaki D. , Patsamanis G. , Chatzianagnostou E. , Vyrsokinos K.
Published: June 2022

In this paper we present a thorough simulation-based analysis for the design of multi-step couplers bridging seamlessly plasmonic barium titanate oxide (BTO) ferroelectric phase shifters and thick silicon nitride (Si3N4) waveguides for the O-band. The targeted plasmonic waveguides are a hybrid plasmonic waveguide (HPW) providing low propagation losses and a plasmonic metal-insulator-metal (MIM) slot waveguide offering a high confinement factor for high modulation efficiency. The proposed plasmonic platforms are formed by Copper (Cu) providing CMOS compatibility. The analysis is based on 2D-FD eigenvalue and 3D-FDTD numerical simulations targeting to identify the optimum geometries ensuring the lowest coupling losses, calculated as 1.75dB for the HPW geometry and 1.29dB for the MIM configuration. The corresponding confinement factors are 31.39% and 56.2% for the HPW and MIM waveguides, respectively.
RGAIA: a reconfigurable AWGR based optical data center network
Authors: Che Jinzhe , Guo Bingli , Pang Zichong , Xue Xuwei , Zhao Yisong , Guo Yuanzhi , Huang Shanguo
Published: June 2022

Benefitting from the cost-effective and flexible interconnection between computing nodes and storing infrastructures, various applications and services are deployed in data centers (DCs). These traffic-boosting applications put tremendous pressures on current electrically switched DC networks (DCNs) which suffer the bandwidth bottleneck. Benefitting from the data-rate and format transparency, the optically switched DCN with intrinsic high-bandwidth characteristics is a promising solution to update the hierarchical electrical DCNs with bandwidth limitations. Moreover, the applications deployed in DCNs with mixed traffic characteristics require dynamic quality of service (QoS) provisioning. Optical DCNs thus need to be designed in a flexible topology with the capability of bandwidth reconfigurability to adapt the variety of the traffic. In this paper, we propose and experimentally investigate a reconfigurable optical packet switching DCN named RGAIA, based on flexible top of racks (ToRs) and fast optical switch, where the optical switch is implemented by tunable transceiver combing with arrayed waveguide grating router (AWGR). Under the management of the designed software defined network (SDN) control plane, RGAIA can dynamically distribute the wavelength resource and then reconfigure the bandwidth in real-time based on the monitored traffic characteristics. Experimental assessments validate RGAIA improving performance of 37% and 66% in latency and packet loss, respectively, compared with the network with rigid interconnections at the traffic load of 0.8.
Self-adaptive deep reinforcement learning for THz beamforming with silicon metasurfaces in 6G communications
Authors: Tan Yi Ji , Zhu Changyan , Tan Thomas Caiwei , Kumar Abhishek , Wong Liang Jie , Chong Yidong , Singh Ranjan
Published: June 2022

Exponential growth in data rate demands has driven efforts to develop novel beamforming techniques for realizing massive multiple-input and multiple-output (MIMO) systems in sixth-generation (6G) terabits per second wireless communications. Existing beamforming techniques rely on conventional optimization algorithms that are too computationally expensive for real-time applications and require complex digital processing yet to be achieved for phased array antennas at terahertz frequencies. Here, we develop an intelligent and self-adaptive beamforming scheme enabled by deep reinforcement learning, which can predict the spatial phase profiles required to produce arbitrary desired radiation patterns in real-time. Our deep learning model adaptively trains an artificial neural network in real-time by comparing the input and predicted intensity patterns via automatic differentiation of the phase-to-intensity function. As a proof of concept, we experimentally demonstrate two-dimensional beamforming by spatially modulating broadband terahertz waves using silicon metasurfaces designed with the aid of the deep learning model. Our work offers an efficient and robust deep learning model for real-time self-adaptive beamforming to enable multi-user massive MIMO systems for 6G terahertz wireless communications, as well as intelligent metasurfaces for other terahertz applications in imaging and sensing.
Tunable bilayer dielectric metasurface via stacking magnetic mirrors
Authors: Song Hao , Hong Binbin , Qiu Yanbing , Yu Kuai , Pei Jihong , Wang Guo Ping
Published: June 2022

Functional tunability, environmental adaptability, and easy fabrication are highly desired properties in metasurfaces. Here we provide a tunable bilayer metasurface composed of two stacked identical dielectric magnetic mirrors. The magnetic mirrors are excited by the interaction between the interference of multipoles of each cylinder and the lattice resonance of the periodic array, which exhibits nonlocal electric field enhancement near the interface and high reflection. We achieve the reversible conversion between high reflection and high transmission by manipulating the interlayer coupling near the interface between the two magnetic mirrors. Controlling the interlayer spacing leads to the controllable interlayer coupling and scattering of meta-atom. The magnetic mirror effect boosts the interlayer coupling when the interlayer spacing is small. Furthermore, the high transmission of the bilayer metasurface has good robustness due to the meta-atom with interlayer coupling can maintain scattering suppression against positional perturbation. This work provides a straightforward method to design tunable metasurface and sheds new light on high-performance optical switches applied in communication and sensing.
Miniature tri-axis accelerometer based on fiber optic Fabry-Pérot interferometer
Authors: Qu Zhiyuan , Lu Ping , Zhang Wanjin , Xiong Wanze , Liu Deming , Zhang Jiangshan
Published: June 2022

A fiber optic accelerometer with a high sensitivity, low noise, and compact size is proposed for low-frequency acceleration sensing. The sensor is composed of a 20 mm diameter spherical outer frame and a three-dimensional spring-mass structure as the inertial sensing element. Three Fabry-Pérot interferometers (FPI) are formed between flat fiber facets and cubic mass surfaces to measure the FPI cavity length change caused by acceleration. The dynamic signal sensing of the designed accelerometer is performed, which shows a high acceleration sensitivity of 42.6 dB re rad/g with a working band of 1-80 Hz. An average minimum detectable acceleration of 4.5 µg/Hz1/2 can be obtained. The sensor features simple assembling, small size, light weight, and good consistency. Its transverse sensitivity is measured to be less than 3% (-30 dB) of the sensitive axis. The experimental result indicates that the proposed accelerometer has application potential in areas such as seismic wave detection and structural health monitoring.
Gigahertz-rate random speckle projection for high-speed single-pixel image classification
Authors: Hanawa Jinsei , Niiyama Tomoaki , Endo Yutaka , Sunada Satoshi
Published: June 2022

Imaging techniques based on single-pixel detection, such as ghost imaging, can reconstruct or recognize a target scene from multiple measurements using a sequence of random mask patterns. However, the processing speed is limited by the low rate of the pattern generation. In this study, we propose an ultrafast method for random speckle pattern generation, which has the potential to overcome the limited processing speed. The proposed approach is based on multimode fiber speckles induced by fast optical phase modulation. We experimentally demonstrate dynamic speckle projection with phase modulation at 10 GHz rates, which is five to six orders of magnitude higher than conventional modulation approaches using spatial light modulators. Moreover, we combine the proposed generation approach with a wavelength-division multiplexing technique and apply it for image classification. As a proof-of-concept demonstration, we show that 28×28-pixel images of digits acquired at GHz rates can be accurately classified using a simple neural network. The proposed approach opens a novel pathway for an all-optical image processor.
Transparent absorber composed of two stacked ultrathin metal films perforated with small holes
Authors: Wu Gaojian , Xiao Wanyue , Wang Ziyan , Zhang Yong , Huang Chengping
Published: June 2022

A transparent absorber refers to the device which can absorb light strongly within a narrow frequency range but transmit light efficiently outside that range. Because of the contradiction between absorption and transmission, however, the performances of the transparent absorbers are usually compromised. In this work, we propose a transparent absorber based on a sandwiched metal-insulator-metal (MIM) structure, i.e., two perforated ultrathin metal films separated by a central dielectric layer. This structure has the advantage that the narrow-band absorption can be greatly enhanced because of the cooperation of surface-plasmon polariton (SPP) mode and multiple reflections in the dielectric cavity. Moreover, the ultrathin thickness of the stacked metal films enables high transmission when the wavelength of incident light deviates from the SPP resonance. A semi-analytical Fabry-Perot model has been employed to describe the optical properties, which agrees well with the simulation. The dependence of optical properties on the structural parameters has also been studied systematically. In addition, by covering the transparent absorber with an antireflection layer, highly efficient absorption of red (∼87% @ 629 nm), green (∼89% @ 524 nm), or blue (∼68% @ 472 nm) light and high transmission (∼80%) in the transparent region have been suggested. With its excellent visible-wavelength selective absorption, polarization independence, high angle-tolerance, and structural simplicity, the proposed MIM transparent absorber may have potential applications in the display technology and other smart scenarios.
On-chip mode division (de)multiplexer for multi-band operation
Authors: Wang Qianshi , He Yu , Wang Hongwei , Wang Zhen , Shen Jian , Zhang Yong , Su Yikai
Published: June 2022

We propose an on-chip mode division (de)multiplexer based on asymmetric directional couplers (ADCs) for multi-band operation. In mode-coupling process, the minimum coupling length is wavelength-dependent. The longer the wavelength is, the shorter the minimum coupling length is. A light of longer wavelength can be coupled back and forth multiple times with a total coupling length which equals to the minimum coupling length of a shorter wavelength light, thus realizing multi-band transmission at different wavelengths. As a proof-of-concept experiment, a four-mode (de)multiplexer for joint operation in the C- and O-Bands is designed and experimentally demonstrated. For the four modes (TE0, TE1, TE2 and TE3), the measured insertion losses (ILs) and crosstalk (CT) of the (de)multiplexer are < 4.7 dB and < −10.1 dB respectively from 1290 nm to 1360 nm, and they are < 3.5 dB and < −11.8 dB respectively from 1510 nm to 1580 nm.
100-mJ class, sub-two-cycle, carrier-envelope phase-stable dual-chirped optical parametric amplification
Authors: Xu Lu , Xue Bing , Ishii Nobuhisa , Itatani Jiro , Midorikawa Katsumi , Takahashi Eiji J.
Published: June 2022

Based on dual-chirped optical parametric amplification (DC-OPA) and type-I BiB3O6 (BiBO) crystals, the generation of >100 mJ, 10.4 fs, 10 Hz, carrier-envelope phase (CEP)-stable laser pulses, which are centered at 1.7 µm, was demonstrated producing a peak power of 10 TW. CEP-dependent high harmonic generation (HHG) was implemented to confirm the sub-two-cycle pulse duration and CEP stabilization of infrared (IR) laser pulses. As far as we know, the obtained pulse energy and peak power represented the highest values for sub-two-cycle CEP-stable IR optical parametric amplification. Additionally, the prospects of achieving high-energy water window isolated attosecond pulses (IAPs) via our developed laser source were discussed.
Unidirectional vortex waveguides and multistable vortex pairs in polariton condensates
Authors: Gao Xinghui , Hu Wei , Schumacher Stefan , Ma Xuekai
Published: June 2022

Vortices carrying quantized topological charges have potential applications in information processing. In this work, we investigate vortex carriers and waveguides in microcavity polariton condensates, nonresonantly excited by a homogeneous pump with intensity grooves. An intensity groove with a ring shape in the pump gives rise to dark-ring states of the condensate with a π-phase jump, akin to dark solitons. The dark-ring states can be destroyed by a stronger density of the surrounding condensate and reduce into vortex–antivortex pairs. Multiple vortex-pair states are found to be stable in the same dark ring of the pump. When the pump ring is broader, higher-order dark states with multiple π-phase jumps can be obtained, and interestingly they can be used to construct vortex waveguides. If a single vortex is imprinted in such waveguides, it can travel in a particular direction, showing one-way transportation. In other words, an imprinted vortex with a certain charge in a specifically designed higher-order dark state is only allowed to propagate unidirectionally.
Effect of different in situ temperatures on the crystallinity and optical properties of green synthesized 8-hydroxyquinoline zinc by saffron extract
Authors: Bakhshipour Shima , Shahedi Zahra , Mirahmadi Farkhondeh , Fereidonnejad Rahele , Hesani Mohadeseh
Published: June 2022

In this research, bis (8-hydroxyquinoline) zinc (ZnQ2) nanoparticles were synthesized by the saffron extract method in a water environment at room temperature using a simple chemical precipitation method. Based on this technique, saffron was utilized as a surfactant due to its non-toxicity and being environmentally friendly. The existence of C-H bonds in the compound of saffron makes it an appropriate material for the green synthesis of ZnQ2 nanoparticles. These kinds of bounds cause reduce the rate of agglomeration of ZnQ2 nanoparticles while of the synthesis process. In this project, the ZnQ2 nanoparticles were synthesized using saffron non-toxic surfactant in different temperatures. The temperature effects from room temperature to 200 °C were considered on the crystal structure of ZnQ2 nanoparticles and their effect on optical properties, an in-situ HT-XRD instrument has been used. The functional groups of the compound, structural, morphology, and fluorescence properties of ZnQ2 nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL) spectroscopy, and Ultraviolet-visible spectroscopy (UV-Vis). According to the results, XRD analysis confirmed the crystalline nature of the synthesized ZnQ2 nanoparticles by the saffron extract. The same bounds were achieved at various temperatures and also with the increase in temperatures of synthesis at 200°C sizes and band gaps were altered from 3.4 nm to 2.5 nm. Therefore, the ZnQ2 nanoparticles are one of the best green materials for replacing transferred electrons materials in optical devices. In conclusion, with utilizing the green materials, Because of reduction the intensity of surface trap and absorption is reduced and the PL of ZnQ2 in the 50°C have reached to 20000. This could be an excellent perspective for using green materials in the organic light-emitting diode and other electronic-optical devices.
Prevalence of, and risk factors for, diabetes and prediabetes in Bangladesh: Evidence from the national survey using a multilevel Poisson regression model with a robust variance
Authors: Hossain Mohammad Bellal , Khan Md. Nuruzzaman , Oldroyd John C. , Rana Juwel , Magliago Dianna J. , Chowdhury Enayet K. , Karim Md Nazmul , Islam Rakibul M.
Published: June 2022

To estimate the age-standardized prevalence of diabetes and prediabetes and identify factors associated with these conditions at individual, household, and community levels. Data from 11952 Bangladeshi adults aged 18–95 years available from the most recent Bangladesh Demographic and Health Survey 2017–18 were used. Anthropometric measurements and fasting blood glucose samples were taken as part of the survey. Prevalence estimates of diabetes and prediabetes were age-standardized with direct standardization, and risk factors were identified using multilevel mix-effects Poisson regression models with robust variance. The overall age-standardised prevalence of diabetes was 9.2% (95%CI 8.7–9.7) (men: 8.8%, women: 9.6%), and prediabetes was 13.3% (95%CI 12.7–13.9) (men: 13.0%, women: 13.6%). Among people with diabetes, 61.5% were unaware that they had the condition. 35.2% took treatment regularly, and only 30.4% of them had controlled diabetes. Factors associated with an increased prevalence of having diabetes were increasing age, male, overweight/obesity, hypertension, being in the highest wealth quintile, and living in the Dhaka division. People currently employed and living in the Rangpur division were less likely to have diabetes than those currently not employed and living in the Barishal division. Diabetes and prediabetes affect a substantial proportion (over one-quarter) of the Bangladeshi adult population. Continuing surveillance and effective prevention and control measures, focusing on obesity reduction and hypertension management, are urgently needed.
Rethinking integrated service delivery for malaria
Authors: Ansah Evelyn K. , Moucheraud Corrina , Arogundade Linda , Rangel Gabriel W.
Published: June 2022

Despite worldwide efforts and much progress toward malaria control, declines in malaria morbidity and mortality have hit a plateau. While many nations achieved significant malaria suppression or even elimination, success has been uneven, and other nations have made little headway—or even lost ground in this battle. These alarming trends threaten to derail the attainment of global targets for malaria control. Among the challenges impeding success in malaria reduction, many strategies center malaria as a set of technical problems in commodity development and delivery. Yet, this narrow perspective overlooks the importance of strong health systems and robust healthcare delivery. This paper argues that strategies that move the needle on health services and behaviors offer a significant opportunity to achieve malaria control through a comprehensive approach that integrates malaria with broader health services efforts. Indeed, malaria may serve as the thread that weaves integrated service delivery into a path forward for universal health coverage. Using key themes identified by the "Rethinking Malaria in the Context of COVID-19" effort through engagement with key stakeholders, we provide recommendations for pursuing integrated service delivery that can advance malaria control via strengthening health systems, increasing visibility and use of high-quality data at all levels, centering issues of equity, promoting research and innovation for new tools, expanding knowledge on effective implementation strategies for interventions, making the case for investing in malaria among stakeholders, and engaging impacted communities and nations.