bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of multi mode arbitrary profile Trench Assisted Fiber for Broadband Applications
Authors: Palodiya Vikram , Raghuwanshi Sanjeev Kumar , Arya Rajeev
Published: February 2023

In this paper, we have designed multi- mode trench-assisted optical fibers with low bending loss and tightly confinement optical power. The optimized design parameters are obtained by introducing trench between inner cladding and outer cladding layer. We have studied the effect of different trench parameters on effective mode field diameter, optical power and field distribution in different modes of optical fiber, theoretically. The analysis shows that the relative refractive index difference in trench affects the properties of mode and power confinement in optical fiber for broadband applications. Broadband communications and access networks, including fiber-to-the-home (FTTH) have been evolving rapidly. Bend insensitive optical fiber, which has a low bending loss, has become particularly attractive as the FTTH service has expanded [1]. There have been many reports on bend-insensitive optical fibers that employ such techniques as reducing the mode field diameter (MFD) [2]. When talking about trench-assisted optical fiber (TA-F), bend-insensitive optical fiber can be used in FTTH applications [3]. The trench can reduce both macro-bending loss [4] and micro-bending loss [5]. It performs perfectly in following the ITU-T G.652 standard to achieve very low bending loss.
Characterizations of a Hexagonal BN-encapsulated Multilayer MoS2 Photodetector
Authors: Ayano Tomoki , Saito Akihisa , Nomura Shintaro
Published: February 2023

Atomically thin layered semiconductor transition metal dichalcogenides have attracted considerable attention for applications such as field-effect transistors (FETs) and photodectors [1]. High photoresponsivity has been demonstrated in molybdenum disulfide (MoS2) FETs, but the photoresponsivity was suffered by the scatterings of the carriers by, for example, the oxide fixed charges and the trapping states induced by adsorbates on the MoS2 channel.
Ultrastrong Light-Matter Coupling in a High-Q Terahertz Cavity
Authors: Kono Junichiro
Published: February 2023

Strong resonant light-matter coupling in a cavity setting is an essential ingredient in fundamental cavity quantum electrodynamics (QED) studies as well as in cavity-QED-based quantum information processing. In particular, a variety of solid-state cavity QED systems have recently been examined, not only for the purpose of developing scalable quantum technologies, but also for exploring novel many-body effects inherent to condensed matter. For example, collective N1/2-fold enhancement of light-matter coupling in an N-body system, combined with colossal dipole moments available in solids, compared to traditional atomic systems, is promising for entering uncharted regimes of ultrastrong light-matter coupling. Nonintuitive quantum phenomena can occur in such regimes, including a squeezed vacuum state, the Dicke superradiant phase transition, the breakdown of the Purcell effect, and quantum vacuum radiation induced by the dynamic Casimir effect. However, creating a system that combines a long electronic coherence time, a large dipole moment, and a high cavity quality (Q) factor has been a challenging goal.
Near Field inductive coupling in Terahertz Metamaterials
Authors: Rao S Jagan Mohan , Kumar Gagan , Chowdhury Dibakar Roy
Published: February 2023

The short range coupling in metamaterials occurs via the electric and magnetic fields due to the close proximity of the neighboring resonators. The electric field mainly couples through the gaps of SRRs, while the magnetic field couples through the circumference [1]. In this work we will focus on the near field inductive coupling in metamaterials. The first problem we have studied the effect of displacements between the resonators inside the unit cell of planar coupled metamaterials. The metamolecule design consists of two planar split- ring resonators (SRRs) which are coupled through the near fields. The numerically simulated transmission spectrum demonstrated split resonances due to the resonance mode hybridization effect. With increase in displacement between the near fields coupled SRRs, this metamaterial system shows a transition from coupled to uncoupled state through merging of the split resonances to the single intrinsic resonance [2]. In another problem we have discussed the near field coupling between the pair of split ring resonators (SRRs) in broadside coupled configuration. The metamaterial design is comprised of two orthogonally twisted broadside coupled SRRs separated by a thin micro-scale polyimide layer (Fig. 1(a)). We analyze the interaction between the meta-layers numerically and analytically by displacing resonators w.r.t. each other. In this system too we have observed split resonances along with frequency tuning of resonances caused by the mode hybridization (Fig. 1(b)) [3]. Such ability to tune resonances should be significant in the development of frequency agile THz devices along with other applications.
Exploit Terajet Generated from Dielectric Cuboid to Enhance Spatial Resolution of THz Imaging System
Authors: Pham Hai Huy Nguyen , Hisatake Shintaro , Minin Igor V. , Minin Oleg V. , Nagatsuma Tadao
Published: February 2023

Recently, a terajet, a jet in the terahertz (THz, 0.1 -10 THz) region, generated from a dielectric cuboid has been introduced [1] and attracted many research interests owing to its capability to obtain subwavelength full width at half maximum (FWHM) that is promising for many applications. The terajet was previously visualized and characterized in the THz region by our unique THz-waves visualization system based on electrooptic (EO) detection [2], e.g. the direct observation of the terajet generation and the angular characteristics of the terajet [3]. In this study, the subwavelength-resolution THz imaging based on the terajet is demonstrated by exploiting the cuboid in an THz imaging system.
Real-time 70 Gbit/s, 128 QAM quantum noise stream cipher transmission over 100 km with secret keys delivered by continuous variable quantum key distribution system
Authors: Nakazawa Masataka
Published: February 2023

We have been intensively studying quantum noise stream cipher (QNSC) transmission technique using quadrature amplitude modulation (QAM) with a view to realizing a high-speed and long-distance secure communication system [1]. In this talk, we describe our recent demonstration of an on-line 70 Gbit/s, 128 QAM/QNSC transmission over 100 km with a continuous variable quantum key distribution (CV-QKD) system [2], in which a shared key is transmitted online via the CV-QKD so that the key is shared for a certain time period with absolutely no risk of being eavesdropped.
Dynamically Unpolarized Single-Photon Source in Diamond with Intrinsic Randomness
Authors: Abe Naofumi , Mitsumori Yasuyoshi , Sadgrove Mark , Edamatsu Keiichi
Published: February 2023

Single-photon sources are essential tools for quantum information technology and testing the foundations of quantum theory. To date, single-photon sources which emit purely polarized single photons (e.g. horizontal polarization and vertical polarization) have been realized in various ways. On the other hand, single-photon sources which emit completely unpolarized single photons are also important for applications such as realizing hardware random number generators and testing the foundations of quantum theory such as the error-disturbance relation for mixed states [1, 2] which are quantum states of unpolarized polarization states. Here, we present a dynamically and statically unpolarized single-photon source using a single nitrogen-vacancy (NV) center in diamond. In particular, we demonstrate a new method for evaluation of dynamical unpolarization using the second order correlation function [3].
Fermi level dependent saturable absorption of grapheme
Authors: Lan Jia-Chi , Wang Yi-Ran , Sung Wei-Heng , Chen Chun-Hu , Tu Li-Wei , Lee Chao-Kuei
Published: February 2023

Graphene has attracted plenty of attentions due to its amazing electric and optical properties. Owing to the unique electronic structure of Dirac cone and massless fermions, the strong optical nonlinearity has been realized and demonstrated with dependency of Fermi level [1]. In this work, Fermi-level tunable p-type graphene was prepared by controlling the relative humidity (RH). The Raman spectrum shows clear tendency of blueshift and the minimum conductance position of field effect transistor (FET) moves to higher applied voltage as increasing the RH. This is due to that electrons in graphene migrate to surface water molecules [2], leading to the downward movement of Fermi level to p-type further. Additionally, the Fermi-level dependent saturation absorption of p-type graphene was also investigated and discussed.
Terpolymer-based polymer optical fiber for multimodal polarization-maintaining
Authors: Mizorogi Daichi , Nihei Eisuke , Furukawa Rei
Published: February 2023

Polarization-maintaining (PM) optical fiber is used in high-speed optical communication and fiberoptic interferometric sensing [1]. Existing PM optical fiber that is known for PANDA fibers intentionally form a large birefringence in the core radially [1]. By taking this structure, the PM function is obtained by suppressing the energy exchange between the orthogonal polarization components of the singlemode optical fiber. However, this principle is not effective in multimode fiber. In the past, it has been reported that a polymer optical fiber (POF) with its core fabricated using copolymer that can reduce intrinsic birefringence, namely, methyl methacrylate (MMA) and benzyl methacrylate (BzMA), exhibit a high extinction ratio compared to the other multimode optical fibers on the premise that no load is applied [2]. Therefore, in this study, POF of ternary core including 2,2,2-trifluoroethyl methacrylate (3FMA) in addition to the earlier material pair was fabricated. P (MMA / 3 FMA / BzMA = 52.0 / 42.0 / 6.0 (w / w / w) is known to be effective in eliminating two types of birefringence, namely, photoelastic birefringence and orientational birefringence [3]. As a result, it was proved that polarization maintaining effect is provided even when load is applied to this multimode fiber.
Measurements of Thermo-Optic Coefficients in Ta2O5 based micro-ring cavity
Authors: Liu Chao-Wei , Wu Chung-Lun , Ou Ding-Shin , Huang Jen-Yang , Chiu Yi-Jen , Shih Min-Hsiung , Chu Ann-Kuo , Lee Chao-Kuei
Published: February 2023

Tantalum pentoxide (Ta2O5) of a large bandgap material has recently utilized to demonstrate nonlinear optical waveguide applications due to its superior linear and nonlinear optical properties [1][2], including low absorption loss coefficient in visible to infrared regions, high Kerr coefficients, and free of nonlinear absorption. In this work, the thermal-optical coefficient of tantalum pentoxide has been investigated experimentally by using a micro-ring resonator structure. Taking the advantage of index-sensitively property of ring resonator, the material with ultralow thermal-optical coefficient is easily to be measured and analyzed by using a ring waveguide structure. The cross-section of Ta2O5 based micro-ring resonator is set as 1.5μm*0.7μm, and the diameter of ring resonator is set as 100μm. By increasing the substrate temperature of micro-ring resonator, the variation of resonant wavelength of micro-ring resonator is recorded accordingly. The central wavelength of micro-ring resonator is red-shifted from 1543.430 nm to 1543.586 nm when the substrate temperature increases from 20 to 40°C. By considering the thermal-optical and thermal expansion effect of micro-ring resonator, the thermal-optical coefficient of Ta2O5 is estimated to be 6.8×10−6 / K at ~1550 nm. The thermal-optical coefficient of Ta2O5 is ten times of magnitude less than those of conventional III–V semiconductors, indicating that Ta2O5 supports the development of thermal-insensitive devices, such as sub-multiplexer and filter element.
Tailored Femtosecond Bessel Beam Processing - Application to Through Si Vias for 3D Si ICs -
Authors: Sugioka Koji , He Fei , Cheng Ya
Published: February 2023

The steady pursuit of high-performance, low-power-consumption, and small-footprint microelectronic devices has made three-dimensional integrated circuits (3D ICs) an attractive replacement for conventional 2D ICs. One of the major challenges to realize 3D ICs is the fabrication of high-aspect-ratio through-silicon vias (TSVs), which is a key technology for the 3D assembly of Si ICs [1]. Here, we propose to employ femtosecond (fs) 1.5-μm Bessel beams for high-speed fabrication of high-quality, high-aspect-ratio through Si holes for TSV application. By performing laser ablation in air using conventional Bessel beams, nearly taper-free through Si holes with diameters of ~3 μm in 50-μm-thick Si substrates, which corresponds to aspect ratios of ~17, can be created. However, severe damage with a concentric structure was produced around created holes due to relatively high sidelobe energy in the Bessel beam. To suppress the severe damage, a fs Bessel beam is tailored by using specially designed binary phase plates (BPPs) for the first time. We theoretically and experimentally demonstrate that this method can generate a fs laser beam with a ~6-μm lateral spot size and ~400-μm focal depth, while reducing the sidelobe ratio (SLR) to ~0.6%, which is much smaller than the ~16% SLR for a conventional Bessel beam. The developed technique successfully eliminates sidelobe-induced damage to ensure high-quality fabrication of through Si holes with a high aspect ratio [2]. Specifically, 2D array of through Si holes with an aspect ratio of ~15 in a 100-μm-thick Si substrate without any sidelobe damage was fabricated as shown in Fig. 1. Our technique is potentially applicable for 3D assembly in the manufacturing of 3D Si ICs.
Nanoscale modification of glass via micro-explosion using ultrafast Bessel laser pulse
Authors: Bhuyan Manoj Kumar , Stoian Razvan , Sugioka Koji
Published: February 2023

In the framework of laser-induced micro- and nanoscale material modification, we present results on ultrafast Bessel beam-glass interaction, inducing extended length scale material modification on single-shot basis. The possibility of high-level energy localization using non-diffractive Bessel beams has been shown using chirped pulses and moderate focusing conditions, drawing attentions in the fields of nonlinear optics and large volume material processing [1, 2]. Here, we show how ultrashort Bessel laser pulse interacts with fused silica glass in a tight focusing geometry and the follow-up material relaxation over a broad range of temporal domain i.e. ns – μs. The consequence of such interaction in terms of ultimate material transformation will be discussed.
Intense Femtosecond Laser-induced X-ray/Ultrasound Emission From Aqueous Solutions in Air
Authors: Hatanaka Koji
Published: February 2023

Intense femtosecond laser interaction with solutions induces various interesting nonlinear phenomena such as laser ablation, plasma formation, and so on. Such phenomena are sensitively dependent on experimental conditions and accompanied with X-ray/ultrasound emission, which can be useful sources for various analytical studies in laboratories. Experimental conditions on the laser excitations and the sample preparations are key issues not only for such practical developments of X-ray/ultrasound sources but also for detailed mechanism discussions on the intense laser-matter interactions, which will be introduced in this talk.
The dynamical structural changes in polymers induced by laser irradiation studied by spectrum-tuned 4D X-ray phase tomography based on X-ray Talbot interferometry
Authors: Vegso (P)Karol , Takano Hidekazu , Wu Yanlin , Hoshino Masato , Han (D)Huajie , Sharma (D)Yash , Momose Atsushi
Published: February 2023

The X-ray Talbot interferometry quantitatively measures phase shift of X-rays in a matter and thus, it is a promising technique to observe soft (low-Z) materials. The X-ray multilayer mirror with bandwidth of 0.1 was installed at beamline BL28B2 at SPring-8 synchrotron radiation facility to reduce radiation damage delivered to the soft-matter specimen. The X-ray Talbot interferometer was constructed downstream of X-ray multilayer mirror at beamline BL28B2 at SPring-8 facility. The polymer specimens of acrylic glass (PMMA) and poly(propyelene) (PP) were illuminated by high-energy infrared laser beam (λ=1064 nm) operating in continuous-wave (CW) mode and propagation of laser-induced pyrolysis in polymer samples was studied by time-resolved X-ray phase imaging. The pilot experiment included fixed sample position and a movie of differential phase images was recorded during laser irradiation with temporal resolution 50 ms. The measurement of movie of differential phase images was continued by 4D X-ray phase CT which provides dynamical change of 3D distribution of real component of index of refraction δ during laser irradiation [1]. The 4D X-ray phase CT using continuous phase stepping method was performed with temporal resolution 4 s. The reconstruction of CT images revealed that defects have character of conically-shaped voids. The growth of burnt area in PP material proceeds from the center of illuminated area to the sample edges (Figs. 1c-d) while in PMMA material, it proceeds from the margin of illuminated area to its center (Figs. 1a-b).
Scalable manufacturing of quantum light emitters in silicon under rapid thermal annealing
Authors: Zhiyenbayev Yertay , Redjem Walid , Ivanov Vsevolod , Qarony Wayesh , Papapanos Christos , Simoni Jacopo , Liu Wei , Jhuria Kaushalya , Tan Liang Z. , Schenkel Thomas , Kanté Boubacar
Published: February 2023

Quantum light sources play a fundamental role in quantum technologies ranging from quantum networking to quantum sensing and computation. The development of these technologies requires scalable platforms, and the recent discovery of quantum light sources in silicon represents an exciting and promising prospect for scalability. The usual process for creating color centers in silicon involves carbon implantation into silicon, followed by rapid thermal annealing. However, the dependence of critical optical properties, such as the inhomogeneous broadening, the density, and the signal-to-background ratio, on centers implantation steps is poorly understood. We investigate the role of rapid thermal annealing on the dynamic of the formation of single color centers in silicon. We find that the density and the inhomogeneous broadening greatly depend on the annealing time. We attribute the observations to nanoscale thermal processes occurring around single centers and leading to local strain fluctuations. Our experimental observation is supported by theoretical modeling based on first principles calculations. The results indicate that annealing is currently the main step limiting the scalable manufacturing of color centers in silicon.
Single-shot 3D shape measurement based on RGB dot patterns and stereovision: retraction
Authors: Lu Yang , Wang Zihao , Yu Liandong , Jia Huakun , Chen Xiaozhe , Gao Rongke , Li Haiju , Wang Yeru , Ma Chao
Published: February 2023

The referenced article [Opt. Express 30, 28220 (2022)10.1364/OE.466148] has been retracted by the authors.
Simulated depolarization ratios for dust and smoke at laser wavelengths: implications for lidar application
Authors: Huang Zhongwei , Shen Xingtai , Tang Shihan , Zhou Tian , Dong Qingqing , Zhang Shuang , Li Meishi , Wang Yongkai
Published: February 2023

Polarization measurements have been widely used to detect aerosol properties by remote sensing in recent decades. To better understand the polarization characteristics of aerosols by lidar, the numerically exact T-matrix method was used to simulate the depolarization ratio (DR) of dust and smoke aerosols at typical laser wavelengths in this study. The results show that the DRs of dust and smoke aerosols have obviously different spectral dependences. Moreover, the ratio of DRs at two wavelengths has an obvious linear relationship with the microphysical properties of aerosols, including aspect ratio, effective radius and complex refractive index. At short wavelengths, we can use it to invert the absorption characteristics of particles, further improving the detection ability of lidar. Comparing the simulation results of different channels, DR, (color ratio) CR and (lidar ratio) LR have a good logarithmic fitting relationship at 532 nm and 1064 nm, which helps to classify the aerosol types. On this basis, a new inversion algorithm, “1β+1α+2δ”, was presented. By this algorithm, the backscattering coefficient (β), extinction coefficient (α), DR (δ) at 532 nm and 1064 nm can be used to expand the range of inversion and compare lidar data with different configurations to obtain more extensive optical characteristics of aerosols. Our study enhances the application of laser remote sensing in aerosol observations more accurately.
Performance of ChatGPT on USMLE: Potential for AI-assisted medical education using large language models
Authors: Kung Tiffany H. , Cheatham Morgan , Medenilla Arielle , Sillos Czarina , De Leon Lorie , Elepaño Camille , Madriaga Maria , Aggabao Rimel , Diaz-Candido Giezel , Maningo James , Tseng Victor
Published: February 2023

We evaluated the performance of a large language model called ChatGPT on the United States Medical Licensing Exam (USMLE), which consists of three exams: Step 1, Step 2CK, and Step 3. ChatGPT performed at or near the passing threshold for all three exams without any specialized training or reinforcement. Additionally, ChatGPT demonstrated a high level of concordance and insight in its explanations. These results suggest that large language models may have the potential to assist with medical education, and potentially, clinical decision-making.
Etiologies of influenza-like illness and severe acute respiratory infections in Tanzania, 2017–2019
Authors: Kelly Maria Ezekiely , Gharpure Radhika , Shivji Sabrina , Matonya Miriam , Moshi Solomon , Mwafulango Ambele , Mwalongo Vumilia , Mghamba Janneth , Simba Azma , Balajee S. Arunmozhi , Gatei Wangeci , Mponela Marcelina , Saguti Grace , Whistler Toni , Moremi Nyambura , Mmbaga Vida
Published: February 2023

In 2016, Tanzania expanded sentinel surveillance for influenza-like illness (ILI) and severe acute respiratory infection (SARI) to include testing for non-influenza respiratory viruses (NIRVs) and additional respiratory pathogens at 9 sentinel sites. During 2017–2019, respiratory specimens from 2730 cases underwent expanded testing: 2475 specimens (90.7%) were tested using a U.S. Centers for Disease Control and Prevention (CDC)-developed assay covering 7 NIRVs (respiratory syncytial virus [RSV], rhinovirus, adenovirus, human metapneumovirus, parainfluenza virus 1, 2, and 3) and influenza A and B viruses. Additionally, 255 specimens (9.3%) were tested using the Fast-Track Diagnostics Respiratory Pathogens 33 (FTD-33) kit which covered the mentioned viruses and additional viral, bacterial, and fungal pathogens. Influenza viruses were identified in 7.5% of all specimens; however, use of the CDC assay and FTD-33 kit increased the number of specimens with a pathogen identified to 61.8% and 91.5%, respectively. Among the 9 common viruses between the CDC assay and FTD-33 kit, the most identified pathogens were RSV (22.9%), rhinovirus (21.8%), and adenovirus (14.0%); multi-pathogen co-detections were common. Odds of hospitalization (SARI vs. ILI) varied by sex, age, geographic zone, year of diagnosis, and pathogen identified; hospitalized illnesses were most common among children under the age of 5 years. The greatest number of specimens were submitted for testing during December–April, coinciding with rainy seasons in Tanzania, and several viral pathogens demonstrated seasonal variation (RSV, human metapneumovirus, influenza A and B, and parainfluenza viruses). This study demonstrates that expanding an existing influenza platform to include additional respiratory pathogens can provide valuable insight into the etiology, incidence, severity, and geographic/temporal patterns of respiratory illness. Continued respiratory surveillance in Tanzania, and globally, can provide valuable data, particularly in the context of emerging respiratory pathogens such as SARS-CoV-2, and guide public health interventions to reduce the burden of respiratory illnesses.
Assessing knowledge and awareness regarding snakebite and management of snakebite envenoming in healthcare workers and the general population: A systematic review and meta-analysis
Authors: Afroz Afsana , Siddiquea Bodrun Naher , Shetty Aishwarya Narendra , Jackson Timothy N. W. , Watt Andrew D.
Published: February 2023

Background

Snakebite envenoming is a serious and life-threatening medical condition that predominantly affects people living in rural communities across Africa, Asia, and Latin America. As our climate changes, there is a growing concern that negative human–snake interactions will increase. Our ability to prevent and manage snakebite requires effective antivenoms as well as knowledge regarding the prevention and management of snakebite among healthcare workers and affected communities across the globe. This systematic review aims to assess existing levels of knowledge regarding snakebite prevention and management in both healthcare workers and affected communities.

Methods

This review was conducted on studies reporting quantitative measurements to evaluate knowledge and practice regarding snakebite prevention and management published in major databases between 1 January 2000 and 31 December 2021. Random effects modelling was used to obtain the pooled proportion. Heterogeneity (I2) was tested, and sensitivity analyses performed.

Results

Out of 3,697 records, 16 studies from 12 countries assessing 7,640 participants were included. Four of the studies were ranked as good quality studies, 9 as fair, and 3 as poor. This study results demonstrated that 56% of the study population answered the knowledge question correctly (95% CI 48% to 63%, p < 0.001). High heterogeneity was observed (I2 = 97.29%), with marginal publication bias (Egger’s regression test, p = 0.0814). Participants had relatively higher knowledge concerning use of antivenom as preferred treatment, followed by snakebite prevention, knowledge of signs and symptoms of snakebite, knowledge of first-aid, and knowledge of treatment. Participants had lower knowledge relating to types of snakes and the identification of snakes.

Conclusion

Adequate knowledge about snakebites and its management among the general population and healthcare workers was 56%. Healthcare workers and communities across Asia showed higher relative knowledge compared to those in Africa and the Middle East. These data suggest that further education is needed in both the general population and among healthcare workers to ensure that appropriate preventative and patient management techniques are being utilised in snakebite endemic regions. Greater local awareness of the risks and appropriate management of snakebite is required to reduce the burden of snakebite mortality and morbidity.
First steps into the cloud: Using Amazon data storage and computing with Python notebooks
Authors: Pollak Daniel J. , Chawla Gautam , Andreev Andrey , Prober David A.
Published: February 2023

With the oncoming age of big data, biologists are encountering more use cases for cloud-based computing to streamline data processing and storage. Unfortunately, cloud platforms are difficult to learn, and there are few resources for biologists to demystify them. We have developed a guide for experimental biologists to set up cloud processing on Amazon Web Services to cheaply outsource data processing and storage. Here we provide a guide for setting up a computing environment in the cloud and showcase examples of using Python and Julia programming languages. We present example calcium imaging data in the zebrafish brain and corresponding analysis using suite2p software. Tools for budget and user management are further discussed in the attached protocol. Using this guide, researchers with limited coding experience can get started with cloud-based computing or move existing coding infrastructure into the cloud environment.
Primary health care during the COVID-19 pandemic: A qualitative exploration of the challenges and changes in practice experienced by GPs and GP trainees
Authors: Grut Minka , de Wildt Gilles , Clarke Joanne , Greenfield Sheila , Russell Alice
Published: February 2023

Background

The COVID-19 pandemic has rapidly changed general practice in the UK. Research is required to understand how General Practitioners (GPs) and GP trainees adjusted to these changes, so that beneficial changes might be sustained, and Primary Health Care (PHC) can be prepared for future challenges. This study explored the experiences and perspectives of GP and GP trainees during the pandemic.

Methods

Remote, semi-structured interviews (n = 21) were conducted with GPs (n = 11) and GP trainees (n = 10), recruited from across the UK using convenience and purposive sampling. Interviews were audio-recorded and transcribed verbatim. Interview data were analysed with an inductive thematic approach.

Results

Five overarching themes were identified: (1)‘Thrown in at the deep end’;(2)Telemedicine:‘it needs to be a happy balance’; (3)Delayed referrals and ‘holding’ patients; (4)The Covid Cohort–training in Covid; (5)Suggestions and lessons for the future of general practice’. GPs reported a turbulent and uncertain time of major changes to PHC. They described the benefits of technology in general medicine, particularly telemedicine, when used in a balanced manner, highlighting the need for accompanying teaching and guidelines, and the importance of patient preferences. Key tools to help GPs manage patients with delayed referrals to Secondary Care were also identified.

Conclusion

Several key changes to general practice occurred as a result of the COVID-19 pandemic, including a rapid uptake of telemedicine. The pandemic exposed the strengths and limitations of normal general practice and highlighted the importance of workplace camaraderie. These findings contribute to the evidence base used to adapt PHC infrastructures as we emerge from the pandemic.
Mutation of regulatory phosphorylation sites in PFKFB2 does not affect the anti-fibrotic effect of metformin in the kidney
Authors: Harley Geoff , Katerelos Marina , Gleich Kurt , Lee Mardiana , Mount Peter F. , Power David A.
Published: February 2023

The anti-fibrotic effect of metformin has been widely demonstrated. Fibrosis in the kidney after injury is associated with reduced expression of genes involved in both fatty acid and glycolytic energy metabolism. We have previously reported that the anti-fibrotic effect of metformin requires phosphoregulation of fatty acid oxidation by AMP-activated protein kinase (AMPK). To determine whether metformin also acts via regulation of glycolysis, we mutated regulatory phosphosites in the PFKFB2 isoform of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB2), a key regulator of glycolysis in the kidney. Mice with inactivating knockin (KI) mutations of the phosphorylation sites in PFKFB2 (PFKFB2 KI mice), which reduces the ability to increase the rate of glycolysis following stimulation, were used. Metformin was administered via drinking water to mice with a unilateral ureteric obstruction (UUO) model of renal fibrosis. In the PFKFB2 KI mice treated with metformin, there was decreased fibrosis and macrophage infiltration following UUO as assessed by Western blot for fibronectin and RT-PCR for α-smooth muscle actin, collagen 3, and F4.80, and confirmed by histology. Expression of the inducible PFKFB3 isoform was increased with metformin in UUO in both WT and PFKFB2 KI mice. There was no significant difference between WT and PFKFB2 KI mice treated with metformin in the degree of fibrosis following UUO in any of the Western blot or RT-PCR parameters that were measured. These data show that inhibition of the regulation of glycolysis by PFKFB2 does not diminish the anti-fibrotic effect of metformin in a model of renal fibrosis.
Efficacy improvement in searching MEDLINE database using a novel PubMed visual analytic system: EEEvis
Authors: Lee Jong-Chan , Lee Brian J. , Park Changhee , Song Hyunjoo , Ock Chan-Young , Sung Hyojae , Woo Sungjin , Youn Yuna , Jung Kwangrok , Jung Jae Hyup , Ahn Jinwoo , Kim Bomi , Kim Jaihwan , Seo Jinwook , Hwang Jin-Hyeok
Published: February 2023

PubMed is the most extensively used database and search engine in the biomedical and healthcare fields. However, users could experience several difficulties in acquiring their target papers facing massive numbers of search results, especially in their unfamiliar fields. Therefore, we developed a novel user interface for PubMed and conducted three steps of study: step A, a preliminary user survey with 76 medical experts regarding the current usability for the biomedical literature search task at PubMed; step B is implementing EEEvis, a novel interactive visual analytic system for the search task; step C, a randomized user study comparing PubMed and EEEvis. First, we conducted a Google survey of 76 medical experts regarding the unmet needs of PubMed and the user requirements for a novel search interface. According to the data of preliminary Google survey, we implemented a novel interactive visual analytic system for biomedical literature search. This EEEvis provides enhanced literature data analysis functions including (1) an overview of the bibliographic features including publication date, citation count, and impact factors, (2) an overview of the co-authorship network, and (3) interactive sorting, filtering, and highlighting. In the randomized user study of 24 medical experts, the search speed of EEEvis was not inferior to PubMed in the time to reach the first article (median difference 3 sec, 95% CI -2.1 to 8.5, P = 0.535) nor in the search completion time (median difference 8 sec, 95% CI -4.7 to 19.1, P = 0.771). However, 22 participants (91.7%) responded that they are willing to use EEEvis as their first choice for a biomedical literature search task, and 21 participants (87.5%) answered the bibliographic sorting and filtering functionalities of EEEvis as a major advantage. EEEvis could be a supplementary interface for PubMed that can enhance the user experience in the search for biomedical literature.
Covariation of taxonomic and functional facets of β-diversity in Chilean freshwater fish assemblages: Implications for current and future processes of biotic homogenization
Authors: Castro Sergio A. , Rojas Pablo , Vila Irma , Jaksic Fabian M.
Published: February 2023

The biodiversity of assemblages that experience the introduction and extinction of species may lead to responses in two important facets: The taxonomic and functional diversity. The way in which these facets are associated may reveal important implications and consequences for the conservation of those assemblages. Considering the critical situation of freshwater fishes in continental Chile (30° – 56° S), we analyzed how the taxonomic (TDβ) and functional (FDβ) facets of β-diversity, and their components of turnover and nestedness, are associated. We evaluated changes in β-diversity (ΔTDβand ΔFDβ), turnover (ΔTDturand ΔFDtur), and nestedness (ΔTDnesand ΔFDnes) in 20 fish assemblages from their historical (pre-European) to current composition. We also simulated future trends of these changes, assuming that native species with conservation issues would become extinct. Our results show that the fish assemblages studied are in a process of loss of β-diversity, both in taxonomic and functional facets (ΔTDβ= -3.9%; ΔFDβ= -30.4%); also, that these facets are positively correlated in the assemblages studied (r= 0.617;P< 0.05). Both components showed by loss in nestedness (ΔTDnes= -36.9%; ΔFDnes= -60.9%) but gain in turnover (ΔTDtur= 9.2%; ΔFDtur= 12.3%). The functional β-diversity decreased more than the taxonomic (ΔFDβ> ΔTDβ), which was caused chiefly by six exotic species of Salmonidae, whose geographical spread was wider and that at the same time shared several morpho-functional traits. Our forecasts, assuming an intensification in the extinction of Endangered and Vulnerable native species, indicate that the process of homogenization will continue, though at a lower rate. Our study shows that the freshwater ichthyofauna of continental Chile is undergoing biotic homogenization, and that this process involves the facets of taxonomic and functional β-diversity, which are show high correlation between historical and current compositions. Both facets show that process is influenced by nestedness, and while turnover contributes to differentiation (both taxonomic and functional), its importance is overshadowed by nestedness.
Detection of BRAF mutations in malignant melanoma and colorectal cancer by SensiScreen® FFPE BRAF qPCR assay
Authors: Sørensen Anna Lahn , Guldmann-Christensen Mariann , Børgesen Michael , Petersen Rasmus Koefoed , Flugt Katharina , Duelund Julie Mejer Holmgaard , Kyneb Majbritt Hauge , Lorenzen Jan , Pipó-Ollé Emma , Epistolio Samantha , Riva Alice , Dazio Giulia , Merlo Elisabetta , Meyer Tine , Christensen Ulf Bech , Frattini Milo
Published: February 2023

Mutations in BRAF exon 15 lead to conformational changes in its activation loops, resulting in constitutively active BRAF proteins which are implicated in the development of several human cancer types. Different BRAF inhibitors have been developed and introduced in clinical practice. Identification of BRAF mutations influences the clinical evaluation, treatment, progression and for that reason a sensitive and specific identification of BRAF mutations is on request from the clinic. Here we present the SensiScreen® FFPE BRAF qPCR Assay that uses a novel real-time PCR-based method for BRAF mutation detection based on PentaBases proprietary DNA analogue technology designed to work on standard real-time PCR instruments. The SensiScreen® FFPE BRAF qPCR Assay displays high sensitivity, specificity, fast and easy-to-use. The SensiScreen® FFPE BRAF qPCR Assay was validated on two different FFPE tumour biopsy cohorts, one cohort included malignant melanoma patients previously analyzed by the Cobas® 4800 BRAF V600 Mutation Test, and one cohort from colorectal cancer patients previously analyzed by mutant-enriched PCR and direct sequencing. All BRAF mutant malignant melanoma patients were confirmed with the SensiScreen® FFPE BRAF qPCR Assay and additional four new mutations in the malignant melanoma cohort were identified. All the previously identified BRAF mutations in the colorectal cancer patients were confirmed, and additional three new mutations not identified with direct sequencing were detected. Also, one new BRAF mutation not previously identified with ME-PCR was found. Furthermore, the SensiScreen® FFPE BRAF qPCR Assay identified the specific change in the amino acid. The SensiScreen® FFPE BRAF qPCR Assay will contribute to a more specific, time and cost saving approach to better identify and characterize mutations in patients affected by cancer, and consequently permits a better BRAF characterization that is fundamental for therapy decision.
A qualitative evidence synthesis exploring people after stroke, family members, carers and healthcare professionals’ experiences of early supported discharge (ESD) after stroke
Authors: Connor Elaine O. , Dolan Eamon , Horgan Frances , Galvin Rose , Robinson Katie
Published: February 2023

Objective

Early supported discharge (ESD) after stroke has been shown to generate significant cost savings and reduce both hospital length of stay, and long-term dependency. This study aimed to systematically review and synthesise qualitative studies of the experiences and views of ESD from the perspective of people after stroke, their family members, carers and healthcare professionals.

Method

A systematic search of eleven databases; CINAHL, PubMed Central, Embase, MEDLINE, PsycINFO, Sage, Academic Search Complete, Directory of Open Access Journal, The Cochrane Library, PsycARTICLES and SCOPUS, was conducted from 1995 to January 2022. Qualitative or mixed methods studies that included qualitative findings on the perspectives or experiences of people after stroke, family members, carers and healthcare professionals of an ESD service were included. The protocol was registered with the Prospero database (Registration: CRD42020135197). The methodological quality of studies was assessed using the 10-item CASP checklist for qualitative studies. Results were synthesised using Thomas and Harden’s three step approach for thematic synthesis.

Results

Fourteen studies were included and five key themes were identified (1) ESD eases the transition home, but not to community services, (2) the home environment enhances rehabilitation, (3) organisational, and interprofessional factors are critical to the success of ESD, (4) ESD is experienced as a goal-focused and collaborative process, and (5) unmet needs persisted despite ESD.

Conclusion

The findings of this qualitative evidence synthesis highlight that experiences of ESD were largely very positive. The transition from ESD to community services was deemed to be problematic and other unmet needs such as information needs, and carer support require further investigation.
Association between sociodemographic factors and cholesterol-lowering medication use in U.S. adults post-myocardial infarction
Authors: Mansi Elizabeth T. , Banks Samantha , Littman Alyson J. , Weiss Noel S.
Published: February 2023

Introduction

Cholesterol-lowering medications offer effective secondary prevention after myocardial infarction (MI). Our objective was to evaluate the association between sociodemographic factors and cholesterol-lowering medication use in high-risk adults.

Methods

We conducted an analysis using weighted data from 31,408 participants in the 2017 and 2019 Behavioral Risk Factor Surveillance Systems cross-sectional surveys, who had a self-reported history of MI and high blood cholesterol. The sociodemographic factors evaluated were sex, age, race and ethnicity, annual household income, education level, relationship status, and reported healthcare coverage. We estimated the weighted prevalence of medication use, and weighted prevalence differences (with 95% confidence intervals) across categories, adjusting for sex, age group, healthcare coverage, smoking status, hypertension, and diabetes.

Results and discussion

Overall, 83% of survey participants with a self-reported history of both MI and high blood cholesterol reported currently using a cholesterol-lowering medication. The prevalence of use was only 61% in those without self-reported healthcare coverage, compared to 85% of those with healthcare coverage (adjusted prevalence difference of -20%; 95% CI: -25% to -14%). Use of cholesterol-lowering medication was relatively low in younger adults and higher in older adults, leveling off after age 65 years. The proportion of Native Hawaiian or Pacific Islanders who were using a cholesterol-lowering medication was relatively low, but otherwise there was little variation by race and ethnicity. Household income, education level, and relationship status were weakly or not associated with medication use.

Conclusions

Knowledge of characteristics of persons who are relatively less likely to be adherent with cholesterol-lowering medications for secondary prevention may be useful to policymakers and healthcare providers involved in the long-term treatment of MI patients. Policy makers might consider a reduced cost prescription coverage for persons without current healthcare coverage who have sustained an MI to reduce future cardiovascular morbidity and mortality.
Mitochondrial genome in sporadic breast cancer: A case control study and a proteomic analysis in a Sinhalese cohort from Sri Lanka
Authors: Jayasekera Lakshika P. , Ranasinghe Ruwandi , Senathilake Kanishka S. , Kotelawala Joanne T. , de Silva Kanishka , Abeygunasekara Priyanka H. , Goonesinghe Renuka , Tennekoon Kamani H.
Published: February 2023

Breast cancer is the commonest malignancy in women and the majority occurs sporadically with no hereditary predisposition. However, sporadic breast cancer has been studied less intensively than the hereditary form and to date hardly any predictive biomarkers exist for the former. Furthermore, although mitochondrial DNA variants have been reported to be associated with breast cancer, findings have been inconsistent across populations. Thus we carried out a case control study on sporadic breast cancer patients and healthy controls of Sinhalese ethnicity (N = 60 matched pairs) in order to characterize coding region variants associated with the disease and to identify any potential biomarkers. Mitochondrial genome was fully sequenced in 30 pairs and selected regions were sequenced in the remaining 30 pairs. Several in-silico tools were used to assess functional significance of the variants observed. A number of variants were identified among the patients and the controls. Missense variants identified were either polymorphisms or rare variants. Their prevalence did not significantly differ between patients and the healthy controls (matched for age, body mass index and menopausal status). MT-CYB, MT-ATP6 and MT-ND2 genes showed a higher mutation rate. A higher proportion of pre-menopausal patients carried missense and pathogenic variants. Unique combinations of missense variants were seen within genes and these occurred mostly in MT-ATP6 and MT-CYB genes. Such unique combinations that occurred exclusively among the patients were common in obese patients. Mitochondrial DNA variants may have a role in breast carcinogenesis in obesity and pre-menopause. Molecular dynamic simulations suggested the mutants, G78S in MT-CO3 gene and T146A in MT-ATP6 gene are likely to be more stable than their wild type counterparts.
Violent victimization at the intersections of sexual orientation, gender identity, and race: National Crime Victimization Survey, 2017–2019
Authors: Flores Andrew R. , Wilson Bianca D. M. , Langton Lynn L. , Meyer Ilan H.
Published: February 2023

Introduction

Prior research has found that experiences with violence in the U.S. differ across individual demographic characteristics, including race, gender, and sexual orientation. However, peer reviewed studies have yet to examine the relationship between the intersections of race, gender, and sexual orientation, victimization risk, and characteristics of victimization.

Methods

We use data from three years (2017–2019) of the National Crime Victimization Survey, the primary source of information on criminal victimization in the United States, to examine victimization at the intersection of sexual orientation, gender, and race/ethnicity. We test whether non-Hispanic Black, Hispanic, and non-Hispanic White sexual and gender minority (SGM) persons aged 16 or over are victimized at greater rates than their non-SGM counterparts and assess whether there are differences between sexual minority females and males of each racial group. We further document characteristics of victimization such as reporting to the police by SGM status and race or ethnicity.

Results

We find that SGMs are disproportionately more likely to be victims of violent crime than non-SGM people, and these disparities are present across the assessed racial and ethnic groups (non-Hispanic Black odds ratio [OR] = 3.3, 90% CI [CI] = 1.36, 5.16; Hispanic OR = 4.5, CI = 2.25, 6.71; non-Hispanic White OR = 4.8, CI = 2.25, 6.71). However, sexual orientation disparities are statistically distinguishable for lesbian or bisexual (LB) non-Hispanic White and Hispanic females but not for non-Hispanic Black LB females. Among LB females, the overall differences in victimization were primarily driven by bisexual respondents. We further find racial and ethnic differences among SGM victims in the likelihood of having the victimization reported to the police, in the utilization of community (non-police) resources, and in other aspects of victimization experiences, such as whether arrests occurred or in the suspicion that the violent incident was a hate crime.

Conclusions

Our findings raise indicate a complex picture of how sexual orientation, gender identity, sex, and race and ethnicity interact in victimizations and their characteristics that should be further explored.