bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF MOO3 CONTENT ON MECHANICAL RESPONSE AND THE ENERGY RELEASE IN METAL/FLUOROPOLYMER COMPOSITE
Authors: YUAN YING , GUO HUANGUO , ZHENG YUANFENG , WANG HAIFU
Published: September 2022

In recent years, PTFE/Al-based reactive materials with high energy density have attracted wide concern, but the low energy release efficiency restricts further application. In this paper, molybdenum trioxide (MoO3) was introduced into PTFE/Al to control the mechanical response and the energy release performance. With the MoO3 content increasing, the material properties gradually change from elastic-plastic to brittle. The ballistic impact experiments are conducted to analyze the overpressure characteristics of PTFE/Al/MoO3. The experimental results showed that the content of MoO3 has significant influence on the energy release behaviors of PTFE/Al-based reactive materials. With the MoO3 content increasing from 10% to 40%, the quasi-static overpressure peak and impulse decrease from 0.147 MPa to 0.105 MPa, and from 9.184 s · kPa to 5.914 s · kPa, respectively. The mechanism analysis showed that, because of Al/MoO3 reaction characteristics, the additional MoO3 affect the shock wave and impact sensitivity of PTFE/Al/MoO3. The study had constructive significance for the application of oxides to promote the energy release performance of PTFE/Al reactive materials.
Audio geolocalizado. El móvil como mediador de experiencias del patrimonio inmaterial
Authors: Piñeiro-Otero Teresa , Martínez-Rolán Xabier , Mihura López Rocío
Published: September 2022

Las nuevas tecnologías no solo han transformado las estrategias de difusión patrimonial, también han favorecido una reflexión en torno a cuestiones como patrimonio, cultura, identidad y participación. La vinculación del patrimonio cultural con el espacio y las comunidades que lo habitan, y la multiplicación de los terminales móviles conectados en los bolsillos de las personas, con sus potencialidades implícitas para la geolocalización y participación han propiciado el desarrollo de nuevas experiencias basadas en la interacción y retroalimentación del espacio virtual y del espacio real. En este sentido, el presente trabajo efectúa una revisión bibliográfica de la literatura de la investigación sobre el sonido como elemento cultural e identitario de un lugar-comunidad, poniendo especial énfasis en las narrativas sonoras como forma de expresión-visibilización del patrimonio cultural para proveer experiencias únicas e inmersivas del espacio, diferentes de las tradicionales. Unas expresiones que aúnan creatividad, diversidad social-cultural y las potencialidades de geoposicionamiento de los dispositivos para ofrecer unas rutas alternativas de la ciudad
Interaction between the mid-infrared continuous wave laser with a center wavelength of 3.8 µm and fused silica
Authors: Pan Yunxiang , Chen Liang , Liu Shengtian , Niu Zhifeng , Nan Pengyu , Ni Xiaowu , Shen Zhonghua , Lu Jian
Published: September 2022

The absorption coefficient of fused silica for a mid-infrared (IR) laser is higher than that for a near-IR laser, but smaller than that for a far-IR laser. Therefore, the energy coupling efficiency of the mid-IR laser is higher than that for the near-IR laser, while the penetration depth is higher than that for the far-IR laser. Thus, the mid-IR laser is highly efficient in mitigating damage growth. In this study, a deuterium fluoride (DF) laser with a center wavelength of 3.8 µm was used to interact with fused silica. The temperature variation, changes in the reflected and transmitted intensities of the probe light incident on the laser irradiation area, and the vaporization and melting sputtering process were analyzed. The results demonstrate that when the laser intensity was low (<1.2 kW/cm2), no significant melting was observed, and the reflection and transmission properties gradually recovered after the end of the laser irradiation process. With a further increase in the laser intensity, the sample gradually melted and vaporized. At a laser intensity above 5.1 kW/cm2, the temperature of the sample increased rapidly and vapors in huge quantity evaporated from the surface of the sample. Moreover, when the laser intensity was increased to 9.5 kW/cm2, the sample melted and an intense melting sputtering process was observed, and the sample was melted through.
Sub-10 nm radial resolution achieved by cascading a graded structure outside a spherical hyperlens
Authors: Xu Jiyu , Zhang Chao , Wang Qi , Liu Hao , Yuan Xueguang , Liu Kai , Zhu Yunxuan , Ren Xiaomin
Published: September 2022

Due to the excellent ability to break the diffraction limit in the subwavelength range, metamaterial-based hyperlens has received extensive attention. Unfortunately, radial resolution of most current hyperlens is not high enough, which is a huge obstacle to the application in 3D super-resolution imaging. In this paper, we propose a theoretical solution to this issue by cascading a graded structure outside the conventional Ag-TiO2 spherical hyperlens. The product of the thickness and the refractive index (RI) of the dielectric layer in the graded structure is fixed to 19.8 while RI increases linearly from 1.38 to 3.54 along the radial direction. By reducing the asymptote slope of the dispersion curve, the coupling of the wave vectors to the hyperlens is enhanced and thus radial resolution is significantly improved to 5 nm while ensuring that the focus is still detectable in the far-field. This design paves the way to high-performance hyperlens for 3D imaging and biosensing in the future.
Low-crosstalk mode-group demultiplexers based on Fabry-Perot thin-film filters
Authors: Vanani Fatemeh Ghaedi , Fardoost Alireza , Zhang Yuanhang , Zhu Zheyuan , Wang Ning , Alvarado-Zacarias Juan Carlos , Amezcua-Correa Rodrigo , Pang Shuo , Li Guifang
Published: September 2022

Mode-group multiplexing (MGM) can increase the capacity of short-reach few-mode optical fiber communication links while avoiding complex digital signal processing. In this paper, we present the design and experimental demonstration of a novel mode-group demultiplexer (MG DeMux) using Fabry-Perot (FP) thin-film filters (TFFs). The MG DeMux supports low-crosstalk mode-group demultiplexing, with degeneracies commensurate with those of graded-index (GRIN) multimode fibers. We experimentally demonstrate this functionality by using a commercial six-cavity TFF that was intended for 100 GHz channel spaced wavelength-division multiplexing (WDM) system.
High finesse bow-tie cavity for strong atom-photon coupling in Rydberg arrays
Authors: Chen Yu-Ting , Szurek Michal , Hu Beili , de Hond Julius , Braverman Boris , Vuletic Vladan
Published: September 2022

We report a high-finesse bow-tie cavity designed for atomic physics experiments with Rydberg atom arrays. The cavity has a finesse of 51,000 and a waist of 7.1 μm at the cesium D2 line (852 nm). With these parameters, the cavity is expected to induce strong coupling between a single atom and a single photon, corresponding to a cooperativity per traveling mode of 35 at the cavity waist. To trap and image atoms, the cavity setup utilizes two in-vacuum aspheric lenses with a numerical aperture (NA) of 0.35 and is capable of housing NA = 0.5 microscope objectives. In addition, the large atom-mirror distance (

≳
1.5

cm) provides good optical access and minimizes stray electric fields at the position of the atoms. This cavity setup can operate in tandem with a Rydberg array platform, creating a fully connected system for quantum simulation and computation.
Portable cavity ring-down spectrometer for an HO2 radical measurement: instrument’s performance and potential improvement using a narrow linewidth laser
Authors: Wang Chunhui , Zhao Weixiong , Fang Bo , Yang Nana , Cheng Feihu , Hu Xiao , Chen Yang , Zhang Weijun , Fittschen Christa , Chen Weidong
Published: September 2022

We report the development of a portable cavity ring-down spectrometer (CRDS) for direct and absolute measurement of HO2 radical concentration using a distributed feedback (DFB) diode laser operating at 1506 nm. The spectrometer has a compact design with all optics in a 1000 × 400 × 140 mm3 box. At a pressure of 100 mbar and a ring-down time (τ0) of 136 µs, the detection limit of the CRDS spectrometer was ∼ 7.3 × 107 molecule/cm3 (1σ, 10s). The corresponding detection sensitivity was 1.5 × 10−11 cm-1, which was close to the state-of-the-art performance. By replacing the DFB diode laser with a narrow linewidth erbium-doped fiber (EDF) laser, the amplitude fluctuation caused by the laser phase noise was reduced and the cavity mode injection efficiency was improved. The sensitivity was improved to 3.9 × 10−12 cm-1 with a short data-acquisition time of 0.2 s. Compared with the DFB laser, the improvement was nearly an order of magnitude. The use of the narrow linewidth laser is attractive. The instrument can achieve very high sensitivity without the need for a complex locking technique, ensuring simple and ease of use in future field applications.
Asymmetric optical multimode splitters by field-assisted ion exchange using patterned mask openings
Authors: Schaeffer Daniel , Klenkert Daniel , Stauch Julian , Foss Wolfgang , Haaf Sebastian , Foerg Raimund , Kufner Maria
Published: September 2022

Asymmetric optical multimode splitters based on optical waveguides were fabricated in glass substrates using a field-assisted ion exchange process. Accompanying simulations, conducted to study the light propagation, revealed the possibility to realize asymmetric splitters based on waveguides with different width. In the exchange process, broad mask openings in the blocking layer are compared to those consisting of closely spaced parallel lines with various widths. The waveguide profiles of the resulting splitters were recorded and the optical losses and splitting ratios were determined for a wavelength of 850 nm. Additionally data transmission tests were conducted and showed the suitability of the splitters for a bandwidth of 28 GBit/s.
Self-mode-locking through intra-cavity sum-frequency generation
Authors: Widarsson Max , Brunzell Martin , Laurell Fredrik , Pasiskevicius Valdas
Published: September 2022

A new technique for mode-locking is demonstrated based on two lasers sharing one leg for sum-frequency generation. When the two lasers had equal round trip time one will produce bright pulses and the other dark pulses. Both lasers used Nd:YVO4 as the gain material, but operated at different wavelengths, namely 1064 nm and 1342 nm. In the present configuration, sub-250 ps pulses were generated at a repetition rate of 276 MHz with an output power of 70 mW. With appropriate choice of round trip loss at the two wavelengths it was possible to choose which laser was generating the bright pulses.
Communication wavelength investigation of bound states in the continuum of one-dimensional two-material periodic ring optical waveguide network
Authors: Zhi Yan , Liu Weici , Yang Xiangbo , Wei Zhongchao , Du Shiping , Meng Hongyun , Liu Hongzhan , Guo Jianping , Yang Manxing , Wang Jianan , Xiang Liujing , Huang Zhenming , Li Haoxian , Wang Faqiang
Published: September 2022

In this study, a one-dimensional (1D) two-material period ring optical waveguide network (TMPROWN) was designed, and its optical properties were investigated. The key characteristics observed in the 1D TMPROWN include the following: (1) Bound states in continuum (BICs) can be generated in the optical waveguide network. (2) In contrast to the BICs previously reported in optical structures, the range of the BICs generated by the 1D TMPROWN is not only larger, but also continuous. This feature makes it possible for us to further study the electromagnetic wave characteristics in the range of the BICs. In addition, we analyzed the physical mechanisms of the BICs generated in the 1D TMPROWN. The 1D TMPROWN is simple in structure, demonstrates flexibility with respect to adjusting the frequency band of the BICs, and offers easy measurement of the amplitude and phase of electromagnetic waves. Hence, further research on high-power super luminescent diodes, optical switches, efficient photonic energy storage, and other optical devices based on the 1D TMPROWN designed in this study is likely to have implications in a broad range of applications.
Ultra-narrow linewidth vertical-cavity surface-emitting laser based on external-cavity weak distributed feedback
Authors: Jiang Lidan , Lan Tianyi , Dang Laiyang , Li Jiali , Huang Ligang , Shi Leilei , Yin Guolu , Zhu Tao
Published: September 2022

We demonstrate an ultra-narrow linewidth vertical-cavity surface-emitting laser (VCSEL) based on external-cavity weak distributed feedback from Rayleigh backscattering (RBS). A single longitudinal mode VCSEL with the linewidth as narrow as 435 Hz and a contrast of 55 dB are experimentally achieved by RBS fiber with a feedback level of RBS signal of -27.6 dB. By adjusting the thermal resistance of the VCSEL from 4.5 kΩ to 7.0 kΩ, the laser wavelength can be tuned from 1543.324 nm to 1542.06 nm with a linear tuning slope of -0.506 nm/kΩ. In the tuning process, the linewidth fluctuates in the range of 553-419 Hz.
Fast response electrically controlled liquid crystal lens array for high resolution 2D/3D switchable display
Authors: Tian Li-Lan , Li Yao , Yin Zhou , Li Lei , Chu Fan
Published: September 2022

A fast response electrically controlled liquid crystal (LC) lens array is revealed. In order to realize the fast response, a double LC layer structure is adopted. The fabricated LC lens array has a small pitch of 310µm and LC layer with a thickness of 50μm. Experimental results show that the focal length of the LC lens array can be continuously adjusted by low driving voltage (∼6.5Vrms), and the shortest focal length is 0.5mm. The switching between 2D display and 3D display is realized by controlling the voltage off and on state of the LC lens array. Experimental result shows that the 2D/3D switchable display has a fast response time of 16ms. The short pitch LC lens array is expected to be used in high-resolution 2D/3D switchable display.
Single-shot quantitative phase imaging with phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination
Authors: Fan Chen , Zhao Hong , Zhao Zixin , Li Junxiang , Du Yijun , Yang Xingyu , Zhang Lu
Published: September 2022

We propose a novel, to the best of our knowledge, single-shot quantitative phase imaging (QPI) technique with the phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination. By studying the phase modulation characteristics of an LC-SLM under white light illumination, images captured at different wavelengths are equivalent to those captured at different defocus distances when loading a Fresnel lens pattern on the LC-SLM. Consequently, a color camera is able to simultaneously acquire multi-intensity images at different defocus distances. Finally, the phase is retrieved from a single-shot color image using the transport of intensity equation. To demonstrate the flexibility and accuracy of our method, a photoetched phase object and human red blood cells are quantitatively measured. An investigation of living yeast cells is conducted to verify the dynamic measurement capability. The proposed method provides a simple, efficient, and flexible means to accomplish real-time high-resolution quantitative phase imaging without sacrificing the field of view (FOV), which can be further integrated into a conventional microscope to achieve real-time microscopic QPI.
Femtotesla 4He magnetometer with a multipass cell
Authors: Liu Yang , Peng Xiang , Wang Haidong , Wang Bowen , Yi Kaiwen , Sheng Dong , Guo Hong
Published: September 2022

In this Letter, we propose a single-beam nonlinear magneto-optical rotation (NMOR) magnetometer with a multipass 4He gas-discharged cell. In contrast to the single-pass cell, the multipass cell allowed laser beams to pass through the metastable-state atomic ensemble 22 times, which directly increases the optical path length and significantly enhances magneto-optical rotation in the 4He gas sample. Based on nonlinear Faraday rotation, the 4He magnetometer with the multipass cell demonstrates a noise floor of 9 fT/Hz1/2, which approaches the photon-shot noise floor limit of 6.4 fT/Hz1/2. In addition, the wider linewidth in metastable-state atoms realizes an NMOR 4He magnetometer with a 3 dB bandwidth of 4.3 kHz, in contrast to the ultranarrow linewidth in the antirelaxation-coated cells or spin-exchange relaxation-free regime alkali-metal cells with buffer gas. Since the 4He cell functions without heating or cryogenic cooling, the femtotesla sensitivity and kilohertz-bandwidth 4He magnetometer exhibits potential in biomagnetic applications such as magnetocardiography and magnetoencephalography.
SCMA-OFDM PON based on chaotic-SLM-PTS algorithms with degraded PAPR for improving network security
Authors: Song Xiumin , Liu Bo , Bai Yu , Chen Shuaidong , Ren Jianxin , Mao Yaya , Zhang Hongxin , Wu Xiangyu , Wu Yongfeng , Xin Xiangjun
Published: September 2022

In this Letter, we propose a novel, to the best of our knowledge, way
to reduce the peak to average power ratio (PAPR) based on the
selective mapping–partial transmit sequence (SLM-PTS) method, which
uses chaotic sequences to give rise to random phases and random split
positions. For the first time, the public and private keys are both
used for encryption in the sparse code multiple access–orthogonal
frequency division multiplexing (SCMA-OFDM) system. The public keys
are used for improvement of the PAPR while the private keys show great
promises in the protection of the privacy for different users.
Meanwhile, the accurate phases and split positions at the receiver can
be easily obtained by transmitting the initial values and parameters
of the 3D Lorenz chaotic system simplifying the transmission of the
sideband information significantly with the key space of nearly
101337. In addition, the transmission of 42-Gb/s encrypted
SCMA-OFDM signals have been experimentally demonstrated over a 2-km
seven-core fiber, showing that the proposed scheme could improve the
receiver sensitivity by 1.0 dB compared with the traditional SCMA-OFDM
signals due to the great reduction in the PAPR. The bit error rate of
the illegal optical network unit remains near 0.5, verifying the high
security of the transmitted message.
Supermode noise mitigation and repetition rate control in a harmonic mode-locked fiber laser implemented through the pulse train interaction with co-lased CW radiation
Authors: Ribenek V. A. , Korobko D. A. , Fotiadi A. A. , Taylor J. R.
Published: September 2022

We report on new, to the best of our knowledge, techniques enabling both the mitigation of supermode laser noise and highly precise setting of the pulse repetition rate (PRR) in a soliton harmonically mode-locked (HML) fiber laser employing nonlinear polarization evolution (NPE). The principle of operation relies on resonant interaction between the soliton pulses and a narrowband continuous wave (CW) component cooperatively generated within the same laser cavity. In contrast to our recent findings [Opt. Lett. 46, 5747 (2021)10.1364/OL.441630 and Opt. Lett. 46, 5687 (2021)10.1364/OL.443042], the new methods are implemented through the specific adjustment of the HML laser cavity only and do not require the use of an external tunable CW laser source.
Efficient generation of mid-infrared few-cycle pulses by the intrapulse difference-frequency generation in YCOB
Authors: Gu Xingbin , Liu Jinsheng , Yuan Peng , Tu Xiaoniu , Zhang Dongfang , Wang Jing , Xie Guoqiang , Ma Jingui
Published: September 2022

Yttrium calcium oxyborate (YCOB) crystals have been widely applied for generating intense near-infrared laser pulses by optical parametric amplification. Here, we show that the YCOB crystals oriented in both the XZ and XY principal planes possess broadband phase-matching property of intrapulse difference-frequency generation in the mid-infrared region. Few-cycle pulses tunable from 2 to 4 µm are experimentally produced by using a 7.5-fs pump laser at 800 nm, in which the conversion efficiency can be as high as 2.5%. With a large-size crystal and high-power pump laser, intrapulse difference-frequency generation based on YCOB may provide a new route for directly producing intense few-cycle mid-infrared pulses.
Reflector-aided underwater optical channel modeling
Authors: Yildiz Samet , Baǧlica İbrahim , Kebapçi Burak , Elamassie Mohammed , Uysal Murat
Published: September 2022

Underwater visible light communication (UVLC) has been proposed as a
high-speed alternative to acoustic signaling. While most UVLC systems
are configured to work in line-of-sight (LOS) conditions, it is also
possible to exploit reflected signals for performance enhancements. In
this Letter, we propose a closed-form expression for the underwater
path loss assuming non-LOS (NLOS) transmission through the water
surface and man-made reflector (e.g., mirror) in addition to the LOS
link. Utilizing the derived expression, we quantify the achievable
NLOS gain defined as the ratio between the maximum achievable channel
coefficient from reflection and the overall channel coefficient. We
validate our findings experimentally by utilizing the water surface
and the mirror as the reflecting surfaces in an aquarium. Our results
reveal that achievable gains up to around 3 dB can be observed due to
reflections.
Active spatial control of photothermal heating and thermo-actuated convective flow by engineering a plasmonic metasurface with heterodimer lattices
Authors: Jing Zhimin , Li Peihang , Ma Cuiping , Wang Jiaying , Caputo Roberto , Govorov Alexander O. , Neogi Arup , Xu Hongxing , Wang Zhiming
Published: September 2022

Thermo-plasmonics, using plasmonic structures as heat sources, has been widely used in biomedical and microfluidic applications. However, a metasurface with single-element unit cells, considered as the sole heat source in a unit cell, functions at a fixed wavelength and has limited control over the thermo-plasmonically induced hydrodynamic effects. Plasmonic metasurfaces with metal disk heterodimer lattices can be viewed to possess two heat sources within a unit cell and are therefore designed to photo-actively control thermal distributions and fluid dynamics at the nanoscale. The locations of heat sources can be switched, and the direction of the convective flow in the central region of the unit cell can be reversed by shifting the wavelength of the excitation source without any change in the excitation direction or physical actuation of the structural elements. The temperature and velocity of a fluid are spatiotemporally controlled by the wavelength selectivity and polarization sensitivity of the plasmonic metasurface. Additionally, we investigate the effects of geometric parameters on the surface lattice resonances and their impact on the temperature and fluid velocity of the optofluidic system. Our results demonstrate excellent optical control of these plasmonic metasurface heating and thermal convection performances to design flexible platforms for microfluidics.
Comparing human and model-based forecasts of COVID-19 in Germany and Poland
Authors: Bosse Nikos I. , Abbott Sam , Bracher Johannes , Hain Habakuk , Quilty Billy J. , Jit Mark ,   Centre for the Mathematical Modelling of Infectious Diseases COVID-19 Working Group, van Leeuwen Edwin , Cori Anne , Funk Sebastian
Published: September 2022

Forecasts based on epidemiological modelling have played an important role in shaping public policy throughout the COVID-19 pandemic. This modelling combines knowledge about infectious disease dynamics with the subjective opinion of the researcher who develops and refines the model and often also adjusts model outputs. Developing a forecast model is difficult, resource- and time-consuming. It is therefore worth asking what modelling is able to add beyond the subjective opinion of the researcher alone. To investigate this, we analysed different real-time forecasts of cases of and deaths from COVID-19 in Germany and Poland over a 1-4 week horizon submitted to the German and Polish Forecast Hub. We compared crowd forecasts elicited from researchers and volunteers, against a) forecasts from two semi-mechanistic models based on common epidemiological assumptions and b) the ensemble of all other models submitted to the Forecast Hub. We found crowd forecasts, despite being overconfident, to outperform all other methods across all forecast horizons when forecasting cases (weighted interval score relative to the Hub ensemble 2 weeks ahead: 0.89). Forecasts based on computational models performed comparably better when predicting deaths (rel. WIS 1.26), suggesting that epidemiological modelling and human judgement can complement each other in important ways.
Bayesian estimation of community size and overlap from random subsamples
Authors: Johnson Erik K. , Larremore Daniel B.
Published: September 2022

Counting the number of species, items, or genes that are shared between two groups, sets, or communities is a simple calculation when sampling is complete. However, when only partial samples are available, quantifying the overlap between two communities becomes an estimation problem. Furthermore, to calculate normalized measures of β-diversity, such as the Jaccard and Sorenson-Dice indices, one must also estimate the total sizes of the communities being compared. Previous efforts to address these problems have assumed knowledge of total community sizes and then used Bayesian methods to produce unbiased estimates with quantified uncertainty. Here, we address communities of unknown size and show that this produces systematically better estimates—both in terms of central estimates and quantification of uncertainty in those estimates. We further show how to use species, item, or gene count data to refine estimates of community size in a Bayesian joint model of community size and overlap.
Cek1 regulates ß(1,3)-glucan exposure through calcineurin effectors in Candida albicans
Authors: Wagner Andrew S. , Lumsdaine Stephen W. , Mangrum Mikayla M. , King Ainsley E. , Hancock Trevor J. , Sparer Timothy E. , Reynolds Todd B.
Published: September 2022

In order to successfully induce disease, the fungal pathogen Candida albicans regulates exposure of antigens like the cell wall polysaccharide ß(1,3)-glucan to the host immune system. C. albicans covers (masks) ß(1,3)-glucan with a layer of mannosylated glycoproteins, which aids in immune system evasion by acting as a barrier to recognition by host pattern recognition receptors. Consequently, enhanced ß(1,3)-glucan exposure (unmasking) makes fungal cells more visible to host immune cells and facilitates more robust fungal clearance. However, an understanding of how C. albicans regulates its exposure levels of ß(1,3)-glucan is needed to leverage this phenotype. Signal transduction pathways and their corresponding effector genes mediating these changes are only beginning to be defined. Here, we report that the phosphatase calcineurin mediates unmasking of ß(1,3)-glucan in response to inputs from the Cek1 MAPK pathway and in response to caspofungin exposure. In contrast, calcineurin reduces ß-glucan exposure in response to high levels of extracellular calcium. Thus, depending on the input, calcineurin acts as a switchboard to regulate ß(1,3)-glucan exposure levels. By leveraging these differential ß(1,3)-glucan exposure phenotypes, we identified two novel effector genes in the calcineurin regulon, FGR41 and C1_11990W_A, that encode putative cell wall proteins and mediate masking/unmasking. Loss of either effector caused unmasking and attenuated virulence during systemic infection in mice. Furthermore, immunosuppression restored the colonization decrease seen in mice infected with the fgr41Δ/Δ mutant to wild-type levels, demonstrating a reliance on the host immune system for virulence attenuation. Thus, calcineurin and its downstream regulon are general regulators of unmasking.
Prevalence estimates of putatively pathogenic leptin variants in the gnomAD database
Authors: Rajcsanyi Luisa Sophie , Zheng Yiran , Fischer-Posovszky Pamela , Wabitsch Martin , Hebebrand Johannes , Hinney Anke
Published: September 2022

Homozygosity for pathogenic variants in the leptin gene leads to congenital leptin deficiency causing severe early-onset obesity. This monogenic form of obesity has mainly been detected in patients from consanguineous families. Prevalence estimates for the general population using the Exome Aggregation Consortium (ExAC) database reported a low frequency of leptin mutations. One in approximately 15 million individuals will be homozygous for a deleterious leptin variant. With the present study, we aimed to extend these findings utilizing the augmented Genome Aggregation Database (gnomAD) v2.1.1 including more than 140,000 samples. In total, 68 non-synonymous and 7 loss-of-function leptin variants were deposited in gnomAD. By predicting functional implications with the help of in silico tools, like SIFT, PolyPhen2 and MutationTaster2021, the prevalence of hetero- and homozygosity for putatively pathogenic variants (n = 32; pathogenic prediction by at least two tools) in the leptin gene were calculated. Across all populations, the estimated prevalence for heterozygosity for functionally relevant variants was approximately 1:2,100 and 1:17,830,000 for homozygosity. This prevalence deviated between the individual populations. Accordingly, people from East Asia and individuals of mixed ethnicities (‘Others’) were at greater risk to carry a possibly damaging leptin variant. Generally, this study emphasises the scarcity of pathogenic leptin variants in the general population with varying prevalence for distinct study groups.
Adverse drug events leading to emergency department visits: A multicenter observational study in Korea
Authors: Kang Min-Gyu , Lee Ju-Yeun , Woo Sung-Il , Kim Kyung-Sook , Jung Jae-Woo , Lim Tae Ho , Yoon Ho Joo , Kim Chan Woong , Yoon Hye-Ran , Park Hye-Kyung , Kim Sang-Heon
Published: September 2022

Adverse drug events are significant causes of emergency department visits. Systematic evaluation of adverse drug events leading to emergency department visits by age is lacking. This multicenter retrospective observational study evaluated the prevalence and features of adverse drug event-related emergency department visits across ages. We reviewed emergency department medical records obtained from three university hospitals between July 2014 and December 2014. The proportion of adverse drug events among total emergency department visits was calculated. The cause, severity, preventability, and causative drug(s) of each adverse drug event were analyzed and compared between age groups (children/adolescents [<18 years], adults [18–64 years], and the elderly [≥65 years]). Of 59,428 emergency department visits, 2,104 (3.5%) were adverse drug event-related. Adverse drug event-related emergency department visits were more likely to be female and older. Multivariate logistic regression analysis revealed that compared to non- adverse drug event-related cases, adverse drug event-related emergency department visitors were more likely to be female (60.6% vs. 53.6%, p<0.001, OR 1.285, 95% CI 1.025–1.603) and older (50.8 ± 24.6 years vs. 37.7 ± 24.4 years, p<0.001, OR 1.892, 95% CI: 1.397–2.297). Comorbidities such as diabetes, chronic kidney disease, chronic liver disease, and malignancies were also significantly associated with adverse drug event-related emergency department visits. Side effects were the most common type of adverse drug events across age groups, although main types differed substantially depending on age. Serious adverse drug events, hospitalizations, and adverse drug event-related deaths occurred more frequently in the elderly than in adults or children/adolescents. The proportion of adverse drug event-related emergency department visits that were preventable was 15.3%. Causative drugs of adverse drug events varied considerably depending on age group. Adverse drug event features differ substantially according to age group. The findings suggest that an age-specific approach should be adopted in the preventive strategies to reduce adverse drug events.
A lightweight noise-tolerant encryption scheme for secure communication: An unmanned aerial vehicle application
Authors: Shafique Arslan , Mehmood Abid , Elhadef Mourad , khan Kashif Hesham
Published: September 2022

In the modern era, researchers have focused a great deal of effort on multimedia security and fast processing to address computational processing time difficulties. Due to limited battery capacity and storage, Unmanned Aerial Vehicles (UAVs) must use energy-efficient processing. In order to overcome the vulnerability of time inefficiency and provide an appropriate degree of security for digital images, this paper proposes a new encryption system based on the bit-plane extraction method, chaos theory, and Discrete Wavelet Transform (DWT). Using confusion and diffusion processes, chaos theory is used to modify image pixels. In contrast, bit-plane extraction and DWT are employed to reduce the processing time required for encryption. Multiple cyberattack analysis, including noise and cropping attacks, are performed by adding random noise to the ciphertext image in order to determine the proposed encryption scheme’s resistance to such attacks. In addition, a variety of statistical security analyses, including entropy, contrast, energy, correlation, peak signal-to-noise ratio (PSNR), and mean square error (MSE), are performed to evaluate the security of the proposed encryption system. Moreover, a comparison is made between the statistical security analysis of the proposed encryption scheme and the existing work to demonstrate that the suggested encryption scheme is better to the existing ones.
Cumulative incidence, prevalence, seroconversion, and associated factors for SARS-CoV-2 infection among healthcare workers of a University Hospital in Bogotá, Colombia
Authors: Valderrama-Beltrán Sandra Liliana , Cuervo-Rojas Juliana , Ariza Beatriz , Cardozo Claudia , Ángel Juana , Martinez-Vernaza Samuel , Juliana Soto María , Arcila Julieth , Salgado Diana , Rondón Martín , Cepeda Magda , Castellanos Julio Cesar , Gómez-Restrepo Carlos , Franco Manuel Antonio
Published: September 2022

This study aimed to determine the cumulative incidence, prevalence, and seroconversion of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its associated factors among healthcare workers (HCWs) of a University Hospital in Bogotá, Colombia. An ambispective cohort was established from March 2020 to February 2021. From November 2020 to February 2021, SARS-CoV-2 antibodies were measured on two occasions 14–90 days apart to determine seroprevalence and seroconversion. We used multivariate log-binomial regression to evaluate factors associated with SARS-CoV-2 infection. Among 2,597 HCWs, the cumulative incidence of infection was 35.7%, and seroprevalence was 21.5%. A reduced risk of infection was observed among those aged 35–44 and ≥45 years (adjusted relative risks [aRRs], 0.84 and 0.83, respectively), physicians (aRR, 0.77), those wearing N95 respirators (aRR, 0.82) and working remotely (aRR, 0.74). Being overweight (aRR, 1.18) or obese (aRR, 1.24); being a nurse or nurse assistant (aRR, 1.20); working in the emergency room (aRR, 1.45), general wards (aRR, 1.45), intensive care unit (aRR, 1.34), or COVID-19 areas (aRR, 1.17); and close contact with COVID-19 cases (aRR, 1.47) increased the risk of infection. The incidence of SARS-CoV-2 infection found in this study reflects the dynamics of the first year of the pandemic in Bogotá. A high burden of infection calls for strengthening prevention and screening measures for HCWs, focusing especially on those at high risk.
Automated prediction of site and sequence of protein modification with ATRP initiators
Authors: Patel Arth , Smith Paige N. , Russell Alan J. , Carmali Sheiliza
Published: September 2022

One of the most straightforward and commonly used chemical modifications of proteins is to react surface amino groups (lysine residues) with activated esters. This chemistry has been used to generate protein-polymer conjugates, many of which are now approved therapeutics. Similar conjugates have also been generated by reacting activated ester atom transfer polymerization initiators with lysine residues to create biomacromolecular initiators for polymerization reactions. The reaction between activated esters and lysine amino groups is rapid and has been consistently described in almost every publication on the topic as a “random reaction”. A random reaction implies that every accessible lysine amino group on a protein molecule is equally reactive, and as a result, that the reaction is indiscriminate. Nonetheless, the literature contradicts itself by also suggesting that some lysine amino groups are more reactive than others (as a function of pKa, surface accessibility, temperature, and local environment). If the latter assumption is correct, then the outcome of these reactions cannot be random at all, and we should be able to predict the outcome from the structure of the protein. Predicting the non-random outcome of a reaction between surface lysines and reactive esters could transform the speed at which active bioconjugates can be developed and engineered. Herein, we describe a robust integrated tool that predicts the activated ester reactivity of every lysine in a protein, thereby allowing us to calculate the non-random sequence of reaction as a function of reaction conditions. Specifically, we have predicted the intrinsic reactivity of each lysine in multiple proteins with a bromine-functionalised N-hydroxysuccinimide initiator molecule. We have also shown that the model applied to PEGylation. The rules-based analysis has been coupled together in a single Python program that can bypass tedious trial and error experiments usually needed in protein-polymer conjugate design and synthesis.
Runs of homocigosity and its association with productive traits in Mexican Holstein cattle
Authors: Cortes-Hernández José G. , Ruiz-López Felipe J. , Vásquez-Peláez Carlos G. , García-Ruiz Adriana
Published: September 2022

The objective of this study was to describe the runs of homozygosity (ROH) detected in the Mexican Holstein population and to associate them with milk, fat and protein yields, and conformation final score. After imputation and genomic quality control, 4,227 genotyped animals with 100,806 SNPs markers each were used. ROH with a minimum length of 1 Mb and a minimum of 10 SNPs were included in the analysis. One heterozygous SNP marker and five missing genotypes per ROH were allowed. A total of 425,098 ROH were found in the studied population (71.83 ± 10.73 ROH per animal), with an average length and coverage of 4.80 ± 0.77 Mb, and 276.89 Mb, respectively. The average chromosome length covered by ROH was 10.40 ± 3.70 Mb. ROH between 1 and 2 Mb were the most frequent in the population (51.33%) while those between 14 and 16 Mb were the least frequent (1.20%). Long chromosomes showed a larger number of ROH. Chromosomes 10 and 20, had a greater percentage of their length covered by ROH because they presented a largest number of long ROH (>8 Mb). From the total ROH, 17 were detected in 1,847 animals and distributed among different chromosomes, and were associated with milk, fat and protein yield and percentage, and conformation final score. Of the ROH with effects on production traits, the majority were found with a length between 1 and 4 Mb. These results show evidence of genomic regions preserved by genetic selection and associated with the improvement of the productivity and functionality of dairy cattle.
Comparison of patient-reported outcomes at one year after injury between limb salvage and amputation: A prospective cohort study
Authors: Kurozumi Taketo , Inui Takahiro , Nakayama Yuhei , Honda Akifumi , Matsui Kentaro , Ishii Keisuke , Suzuki Takashi , Watanabe Yoshinobu
Published: September 2022

Purpose

This single-center, prospective cohort study aimed to compare the patient-reported outcomes one year after injury between limb salvage and amputation and to elucidate whether amputation contributes to early recovery of functionality and quality of life.

Methods

We included 47 limbs of 45 patients with severe open fractures of the lower limb and categorized them into limb salvage and amputation groups. Data on patient-reported outcomes one year after injury were obtained from the Database of Orthopaedic Trauma by the Japanese Society for Fracture Repair at our center. Patients’ limbs were evaluated using the lower extremity functional scale and Short-Form 8. Early recovery was assessed using functionality and quality-of-life questionnaires.

Results

Of the 47 limbs, 34 limbs of 34 patients were salvaged, and 13 limbs of 11 patients were amputated. Significant differences were noted between the limb salvage and amputation groups in terms of the lower extremity functional scale scores (mean: 49.5 vs. 33.1, P = 0.025) and scores for the mental health component (mean: 48.7 vs. 38.7, P = 0.003), role–physical component (mean: 42.2 vs. 33.3, P = 0.026), and mental component summary (mean: 48.2 vs. 41.3, P = 0.042) of the Short-Form 8. The limb salvage group had better scores than the amputation group.

Conclusions

As reconstruction technology has advanced and limb salvaging has become possible, the focus of studies should now be based on the perspective of “how the patient feels;” hence, we believe that the results of this study, which is based on patient-reported outcomes, are meaningful.
Comparative efficacy and safety of caffeine citrate and aminophylline in treating apnea of prematurity: A systematic review and meta-analysis
Authors: Miao Yiqun , Zhou Yun , Zhao Shuliang , Liu Wenwen , Wang Aihua , Zhang Yuanyuan , Li Yanan , Jiang Huimin
Published: September 2022

Background

Methylxanthine, including caffeine citrate and aminophylline, is the most common pharmacologic treatment for apnea of prematurity. However, due to the lack of high-quality evidence, there are no clear recommendations or guidelines on how to choose between caffeine and aminophylline.

Objective

This meta-analysis aimed to assess the comparative efficacy and safety of caffeine and aminophylline for apnea of prematurity, and provide reliable evidence for clinical medication in the treatment for apnea of prematurity.

Methods

PubMed, Scopus, Embase, EBSCO, Web of Science, and Cochrane databases were systematically searched from May 1975 to June 2022.

Results

Ten studies including a total of 923 preterm infants were evaluated. Our results showed that there was no significant difference in the effective rate of 1-3days between caffeine and aminophylline (OR 1.05, 95%CI: 0.40–2.74, P = 0.914). However, for side effects such as tachycardia (OR 0.22, 95%CI: 0.13–0.37, P<0.001) and feeding intolerance (OR 0.40, 95%CI: 0.23–0.70, P = 0.001), the incidence rate was lower in the caffeine group compared with the aminophylline group. No significant difference was found in hyperglycemia (OR 0.45, 95%CI: 0.19–1.05, P = 0.064).

Conclusion

This meta-analysis reveals that caffeine citrate and aminophylline have similar therapeutic effectiveness on respiratory function, but caffeine has fewer side effects and should be considered first for treatment.
Factor structure of intelligence and divergent thinking subtests: A registered report
Authors: Warne Russell T. , Golightly Sam , Black Makai
Published: September 2022

Psychologists have investigated creativity for 70 years, and it is now seen as being an important construct, both scientifically and because of its practical value to society. However, several fundamental unresolved problems persist, including a suitable definition of creativity and the ability of psychometric tests to measure divergent thinking—an important component of creativity—in a way that aligns with theory. It is this latter point that this registered report is designed to address. We administered two divergent thinking tests (the verbal and figural versions of the Torrance Tests of Creative Thinking; TTCT) with an intelligence test (the International Cognitive Ability Resource test; ICAR). We then subjected the subscores from these tests to confirmatory factor analysis to examine which of nine theoretically plausible models best fits the data. Results show that none of the pre-registered models fit the data well, an ambiguous result that leaves unanswered the question of whether intelligence and divergent thinking tests measure the same construct. Exploratory (i.e., not pre-registered) measurement models of each test separately shows that the TTCT-F may not measure a coherent, unitary construct—leading to model misspecification when TTCT-F subtests were included in larger models. This study was conducted in accordance with all open science practices, including pre-registration, open data and syntax, and open materials (with the exception of copyrighted and confidential test stimuli). Materials are available at https://osf.io/8rpfz/.
Neurotrauma clinicians’ perspectives on the contextual challenges associated with traumatic brain injury follow up in low-income and middle-income countries: A reflexive thematic analysis
Authors: Smith Brandon G. , Whiffin Charlotte J. , Esene Ignatius N. , Karekezi Claire , Bashford Tom , Mukhtar Khan Muhammad , Fontoura Solla Davi J. , Indira Devi Bhagavatula , Paiva Wellingson S. , Servadei Franco , Hutchinson Peter J. , Kolias Angelos G. , Figaji Anthony , Rubiano Andres M.
Published: September 2022

Background

Traumatic brain injury (TBI) is a major global health issue, but low- and middle-income countries (LMICs) face the greatest burden. Significant differences in neurotrauma outcomes are recognised between LMICs and high-income countries. However, outcome data is not consistently nor reliably recorded in either setting, thus the true burden of TBI cannot be accurately quantified.

Objective

To explore the specific contextual challenges of, and possible solutions to improve, long-term follow-up following TBI in low-resource settings.

Methods

A cross-sectional, pragmatic qualitative study, that considered knowledge subjective and reality multiple (i.e. situated within the naturalistic paradigm). Data collection utilised semi-structured interviews, by videoconference and asynchronous e-mail. Data were analysed using Braun and Clarke’s six-stage Reflexive Thematic Analysis.

Results

18 neurosurgeons from 13 countries participated in this study, and data analysis gave rise to five themes: Clinical Context: What must we understand?; Perspectives and Definitions: What are we talking about?; Ownership and Beneficiaries: Why do we do it?; Lost to Follow-up: Who misses out and why?; Processes and Procedures: What do we do, or what might we do?

Conclusion

The collection of long-term outcome data plays an imperative role in reducing the global burden of neurotrauma. Therefore, this was an exploratory study that examined the contextual challenges associated with long-term follow-up in LMICs. Where technology can contribute to improved neurotrauma surveillance and remote assessment, these must be implemented in a manner that improves patient outcomes, reduces clinical burden on physicians, and does not surpass the comprehension, capabilities, or financial means of the end user. Future research is recommended to investigate patient and family perspectives, the impact on clinical care teams, and the full economic implications of new technologies for follow-up.