bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized chromatic aberrations in non-rotationally symmetric optical systems–Part I: mathematical approach
Authors: Cai Danyun , Gross Herbert
Published: June 2021

In non-rotationally symmetric optical systems, chromatic aberrations must be defined in a generalized way with reference to the optical axis ray and optimal tilted parabasal image plane of the central wavelength. In this paper, the definition of generalized chromatic aberrations is clarified. The mathematical calculation in optical systems with arbitrary symmetry and surface shape is realized by ray- and wavefront-based methods, respectively, that are originally identical. The additivity of wavefront after each surface ensures the surface decomposition of chromatic aberrations. In the end, the influence of pupil aberration, which is of a higher order, is discussed. The consistency of our methods with Seidel aberrations in the lowest aberration order of the rotationally symmetric system and the application of our methods in diverse non-rotationally symmetric refractive systems will be addressed in detail in Part II.
Image transmission using Airy array beam
Authors: Zhou Yi , Yuan Fengpei , Xie Guojun , Zhao Lichang
Published: June 2021

An approach for image transmission based on the Airy array beam is proposed and demonstrated. The Airy array beam is generated by employing the product of a special cubic phase and a shift function at its Fourier plane. The image can be modulated into this Airy array beam by overlapping it at the Fourier plane of this beam. After passing through a certain distance, the image information can be recovered from the modulated Airy array beam by Fourier transform. Compared to the existing Airy array beam, higher integrity and image information quality can be achieved by increasing the width of the obstacle that blocks the propagation of these beams. The capability mentioned above is experimentally verified. Moreover, to research the diffraction of this Airy array beam in the scattering environment, the propagation process of this Airy array beam in a scattering medium is theoretically derived and numerically studied. The corresponding experiment demonstrates that the propagation process matches well with the numerical study and simulation.
Closed-loop wavefront sensing and correction in the mouse brain with computed optical coherence microscopy
Authors: Liu Siyang , Xia Fei , Yang Xusan , Wu Meiqi , Bizimana Laurie A. , Xu Chris , Adie Steven G.
Published: June 2021

Optical coherence microscopy (OCM) uses interferometric detection to capture the complex optical field with high sensitivity, which enables computational wavefront retrieval using back-scattered light from the sample. Compared to a conventional wavefront sensor, aberration sensing with OCM via computational adaptive optics (CAO) leverages coherence and confocal gating to obtain signals from the focus with less cross-talk from other depths or transverse locations within the field-of-view. Here, we present an investigation of the performance of CAO-based aberration sensing in simulation, bead phantoms, and ex vivo mouse brain tissue. We demonstrate that, due to the influence of the double-pass confocal OCM imaging geometry on the shape of computed pupil functions, computational sensing of high-order aberrations can suffer from signal attenuation in certain spatial-frequency bands and shape similarity with lower order counterparts. However, by sensing and correcting only low-order aberrations (astigmatism, coma, and trefoil), we still successfully corrected tissue-induced aberrations, leading to 3× increase in OCM signal intensity at a depth of ∼0.9 mm in a freshly dissected ex vivo mouse brain.
Single-laser-based simultaneous four-wavelength excitation source for femtosecond two-photon fluorescence microscopy
Authors: Hsiao Yang-Ting , Huang Yu-Fan , Borah Bhaskar Jyoti , Chen Shih-Kuo , Sun Chi-Kuang
Published: June 2021

Multicolor labeling of biological samples with large volume is required for omic-level of study such as the construction of nervous system connectome. Among the various imaging method, two photon microscope has multiple advantages over traditional single photon microscope for higher resolution and could image large 3D volumes of tissue samples with superior imaging depth. However, the growing number of fluorophores for labeling underlines the urgent need for an ultrafast laser source with the capability of providing simultaneous plural excitation wavelengths for multiple fluorophores. Here, we propose and demonstrate a single-laser-based four-wavelength excitation source for two-photon fluorescence microscopy. Using a sub-100 fs 1,070-nm Yb:fiber laser to pump an ultrashort nonlinear photonic crystal fiber in the low negative dispersion region, we introduced efficient self-phase modulation and acquired a blue-shifted spectrum dual-peaked at 812 and 960 nm with 28.5% wavelength conversion efficiency. By compressing the blue-shift near-IR spectrum to 33 fs to ensure the temporal overlap of the 812 and 960 nm peaks, the so-called sum frequency effect created the third virtual excitation wavelength effectively at 886 nm. Combined with the 1,070 nm laser source as the fourth excitation wavelength, the all-fiber-format four-wavelength excitation source enabled simultaneous four-color two-photon imaging in Brainbow AAV-labeled (TagBFP, mTFP, EYFP, and mCherry) brain samples. With an increased number of excitation wavelengths and improved excitation efficiency than typical commercial femtosecond lasers, our compact four-wavelength excitation approach can provide a versatile, efficient, and easily accessible solution for multiple-color two-photon fluorescence imaging in the field of neuroscience, biomolecular probing, and clinical applications with at least four spectrally-distinct fluorophores.
Noninvasive OCT angiography-based blood attenuation measurements correlate with blood glucose level in the mouse retina
Authors: Liu Kaiyuan , Zhu Tiepei , Yao Lin , Zhang Ziyi , Li Huakun , Ye Juan , Li Peng
Published: June 2021

In this study, we investigated the correlation of the blood optical attenuation coefficient (OAC) and the blood glucose concentration (BGC). The blood OAC was measured in mouse retina in vivo by analyzing the depth attenuation of backscattered light under the guidance of OCT angiography (OCTA) vascular mapping, and then its correlation to the BGC was further investigated. The optical attenuation of the blood components presented a more reliable correlation to BGC than that of the background tissues. The arteries and veins presented a blood OAC change of ∼0.05-0.07 mm-1 per 10 mg/dl and a significant (P < 0.001) elevation of blood OAC in diabetic mice was observed. Furthermore, different kinds of vessels also presented different performances. The veins had a higher correlation coefficient (R=0.86) between the measured blood OAC and BGC than that of the arteries (R=0.73). Besides, the blood OAC changes of the specific vessels occur without any obvious change in the vascular morphology in the retina. The blood OAC-BGC correlation suggests a concept of non-invasive OCTA-based glucometry, allowing a fast assessment of the blood glucose of specific vessels with superior motion immunity. A direct glucometry of the retina would be helpful for accurately monitoring the progression of diabetic retinopathy.
Machine-learning-based soft-failure localization with partial software-defined networking telemetry
Authors: Mayer Kayol S. , Soares Jonathan A. , Pinto Rossano P. , Rothenberg Christian E. , Arantes Dalton S. , Mello Darli A. A.
Published: June 2021

Soft-failure localization frameworks typically use if-else rules to localize failures based on the received telemetry data. However, in certain cases, particularly in disaggregated networks, some devices may not implement telemetry, or their telemetry may not be readily available. Alternatively, machine-learning-based (ML-based) frameworks can automatically learn complex relationships between telemetry and the fault location, incorporating information from the telemetry data collected network-wide. This paper evaluates an ML-based soft-failure localization framework in scenarios of partial telemetry. The framework is based on an artificial neural network (ANN) trained by optical signal and noise power models that simulate the network telemetry upon all possible failure scenarios. The ANN can be trained in less than 2 min, allowing it to be retrained according to the available partial telemetry data. The ML-based framework exhibits excellent performance in scenarios of partial telemetry, practically interpolating the missing data. We show that in the rare cases of incorrect failure localization, the actual failure is in the localized device’s vicinity. We also show that ANN training is accelerated by principal component analysis and can be carried out using cloud-based services. Finally, the evaluated ML-based framework is emulated in a software-defined-networking-based setup using the gNMI protocol for streaming telemetry.
Zero touch provisioning compliant with authentications of IEEE PON packages A and B for SDN-enabled broadband access
Authors: Suzuki Takahiro , Koyasako Yushi , Nishimoto Keita , Asaka Kota , Yamada Takashi , Kani Jun-ichi , Shimada Tatsuya , Yoshida Tomoaki
Published: June 2021

Passive optical networks (PONs) are widely deployed worldwide as access networks, and various standards have been created to serve the demands of different markets. In recent years, software-defined-network-enabled broadband access (SEBA) has been studied for the realization of flexible and cost-effective PONs, while the zero touch provisioning (ZTP) function of optical line terminals (OLTs) and optical network units (ONUs) is being studied for automatic management. However, although ZTP for ITU-T standards has already been implemented, ZTP for IEEE standards has not been achieved, since the workflow is significantly different for each access standard due to differences in the authentication method. The subdivided package specifications and medium access control (MAC) dress authentication are barriers that hinder achieving ZTP for the IEEE standards. This paper proposes a workflow driver based on a model that implements authentication compliant with IEEE PON packages A and B according to events produced by SEBA components and specification information obtained from OLT profiles. The feature of our proposal is to fabricate an IEEE-compliant driver package that automatically switches the authentication method by acquiring the technology profile of the orchestrator, and as soon as IEEE802.1X authentication or MAC address authentication is completed, the subscriber setting is registered to the SDN controller in order to enable data plane service. We demonstrate the proposed workflow driver on a system consisting of SEBA-focused commercially available OLT/ONU hardware and open source software. The results show that the orchestrator can automatically provision ONUs and that managing various access devices on a common access platform is feasible.
Great enhancement on two-photon photoluminescence imaging contrast of Au nanoparticles via double-pulse femtosecond laser excitation with controlled phase differences
Authors: Li Yao , Qin Chengbing , Song Yunrui , Yan Hongyan , Han Shuangping , Zhou Haitao , Wei Aoni , Zhang Guofeng , Chen Ruiyun , Hu Jianyong , Jing Mingyong , Xiao Liantuan , Jia Suotang
Published: June 2021

Au nanoparticles are attractive contrast agents for noninvasive living tissue imaging with deep penetration because of their strong two-photon photoluminescence (TPPL) intensity and excellent biocompatibility. However, the inevitable phototoxicity and huge auto-fluorescence are consistently associated with laser excitation. Therefore, enhancement of TPPL intensity and suppression of backgrounds are always highly desired under the demand of reducing excitation powers. In this work, we develop a double-pulse TPPL (DP-TPPL) scheme with controlled phase differences (Δφ) between the double pulses to significantly improve the signal-to-noise ratio (SNR) of TPPL imaging. Under the modulated phase (Δφ periodically varying between 0–2π), our results show that SNR can be improved from 4.3 to 1715, with an enhancement of up to 400 folds at the integration of 50 ms. More importantly, this enhancement can be unlimitedly lifted by increasing the number of photons or integration times in principle. Further boosting has been achieved by reducing the magnitude of background noises; subsequently, SNR is improved by more than 104 times. Our schemes offer great potential for reducing phototoxicity and extracting extremely weak signals from huge backgrounds and open up a new possibility for a rapid, flexible, and reliable medical diagnosis by TPPL imaging with diminished laser powers.
Single-plane and multiplane quantitative phase imaging by self-reference on-axis holography with a phase-shifting method
Authors: Hai Nathaniel , Rosen Joseph
Published: June 2021

A new quantitative phase imaging approach is proposed based on self-reference holography. Three on-axis interferograms with different values of the phase filter are superposed. The superposition yields a more accurate phase map of the wavefront emerging from the object, compared with standard off-axis interferometry. Reduced temporal noise levels in the measured phase map and efficient phase recovery process for optically thin and thick transmissive phase objects highlight the applicability of the suggested framework for various fields ranging from metrology to bio-imaging. Qualitative phase imaging is also done online without altering the optical configuration. Qualitative phase detections of multiple planes of interest are converted to quantitative phase maps of the multiplane scene by a rapid phase contrast-based phase retrieval algorithm, from a single camera exposure and with no moving parts in the system.
Frequency-resolved spatial beam mapping in multimode fibers: application to mid-infrared supercontinuum generation
Authors: Leventoux Y. , Granger G. , Krupa K. , Mansuryan T. , Fabert M. , Tonello A. , Wabnitz S. , Couderc V. , Février S.
Published: June 2021

We present a new, to the best of our knowledge, spatial-spectral mapping technique permitting measurement of the beam intensity at the output of a graded-index multimode fiber (GIMF) with sub-nanometric spectral resolution. We apply this method to visualize the fine structure of the beam shape of a sideband generated at 1870 nm by geometric parametric instability (GPI) in a GIMF. After spatial-spectral characterization, we amplify the GPI sideband with a thulium-doped fiber amplifier to obtain a microjoule-scale picosecond pump whose spectrum is finally broadened in a segment of

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n
F

3

optical fiber to achieve a supercontinuum ranging from 1.7 up to 3.4 µm.
Linearity improvement of analog photonic link based on a phase-coherent orthogonal light wave generator
Authors: Han Mengyao , Wang Muguang , Wu Beilei , Zhang Naihan , Mu Hongqian , Zhang Jianyong , Yan Fengping
Published: June 2021

This Letter presents a novel, to the best of our knowledge, linearized analog photonic link (APL) based on a phase-coherent orthogonal light wave generator that consists of a polarization-dependent Mach–Zehnder modulator (MZM) and a polarization controller (PC). By adjusting the PC and bias voltage of MZM, the third-order intermodulation (IMD3) terms can be suppressed while retaining a high gain for the fundamental terms, which indicates that the spurious free dynamic range (SFDR) of the proposed APL can be much improved. To further verify the feasibility of the proposed APL, a proof-of-concept experiment is performed, and the performances are compared with conventional APL. The experimental results demonstrate that a 14 dB improvement in the fundamental to IMD3 power ratio and an SFDR of

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are achieved. In addition, an orthogonal frequency division multiplexing signal with 30 MHz bandwidth centered at 2.5 GHz is delivered by our proposed APL, whose signal-to-noise ratio is increased by 10 dB, compared to conventional APL.
Suppression of photo-induced effects in chemically stoichiometric Ge26.67Ga8S65.33 glasses
Authors: Sun Yuanhuan , Zhang Zheng , Yang Zhen , Niu Lei , Wu Jian , Wei Tengxiu , Yan Kunlun , Sheng Yan , Wang Xunsi , Wang Rongping
Published: June 2021

We have prepared GexGa8S92-x glasses with x=20, 26.67 and 36, and investigated the photoinduced effects under illumination at sub-bandgap wavelength with different power densities. It was found that, Ge20 and Ge36 undergo photodarkening (PD) and photobleaching (PB), respectively, and the change of transmission ratio with and without illumination increases with increasing illumination power density as well as prolonging illumination time. On the other hand, Ge26.67 is almost optical stable in any cases. This potentially offers a chance to reduce additional optical loss induced by PD and achieve net optical gain in the erbium doped chalcogenide planar waveguide amplifier using chemically stoichiometric Ge26.67 glass.
Recent progress in the development of β-Ga2O3 scintillator crystals grown by the Czochralski method
Authors: Drozdowski Winicjusz , Makowski Michał , Witkowski Marcin E. , Wojtowicz Andrzej J. , Irmscher Klaus , Schewski Robert , Galazka Zbigniew
Published: June 2021

A high-quality bulk single crystal of β-Ga2O3 has been grown by the Czochralski method and its basic scintillation characteristics (light yield, energy resolution, proportionality, and scintillation decay times) have been investigated. All the samples cut from the crystal show promising scintillation yields between 8400 and 8920 ph/MeV, which is a noticeable step forward compared to previous studies. The remaining parameters, i.e. the energy resolution slightly above 10% (at 662 keV) and the scintillation mean decay time just under 1 μs, are at the same level as we have formerly recognized for β-Ga2O3. The proportionality of yield seems not to deviate from standards determined by other commercial scintillators.
Rheumatic heart disease in pregnancy and neonatal outcomes: A systematic review and meta-analysis
Authors: Liaw Joshua , Walker Betrice , Hall Leanne , Gorton Susan , White Andrew V. , Heal Clare
Published: June 2021

Purpose

Associations between rheumatic heart disease (RHD) in pregnancy and fetal outcomes are relatively unknown. This study aimed to review rates and predictors of major adverse fetal outcomes of RHD in pregnancy.

Methods

Medline (Ovid), Pubmed, EMcare, Scopus, CINAHL, Informit, and WHOICTRP databases were searched for studies that reported rates of adverse perinatal events in women with RHD during pregnancy. Outcomes included preterm birth, intra-uterine growth restriction (IUGR), low-birth weight (LBW), perinatal death and percutaneous balloon mitral valvuloplasty intervention. Meta-analysis of fetal events by the New-York Heart Association (NYHA) heart failure classification, and the Mitral-valve Area (MVA) severity score was performed with unadjusted random effects models and heterogeneity of risk ratios (RR) was assessed with the I2statistic. Quality of evidence was evaluated using the GRADE approach. The study was registered in PROSPERO (CRD42020161529).

Findings

The search identified 5949 non-duplicate records of which 136 full-text articles were assessed for eligibility and 22 studies included, 11 studies were eligible for meta-analyses. In 3928 pregnancies, high rates of preterm birth (9.35%-42.97%), LBW (12.98%-39.70%), IUGR (6.76%-22.40%) and perinatal death (0.00%-9.41%) were reported. NYHA III/IV pre-pregnancy was associated with higher rates of preterm birth (5 studies, RR 2.86, 95%CI 1.54–5.33), and perinatal death (6 studies, RR 3.23, 1.92–5.44). Moderate /severe mitral stenosis (MS) was associated with higher rates of preterm birth (3 studies, RR 2.05, 95%CI 1.02–4.11) and IUGR (3 studies, RR 2.46, 95%CI 1.02–5.95).

Interpretation

RHD during pregnancy is associated with adverse fetal outcomes. Maternal NYHA III/IV and moderate/severe MS in particular may predict poor prognosis.
Stress and anxiety among physicians during the COVID-19 outbreak in the Iraqi Kurdistan Region: An online survey
Authors: Saeed Banaz A. , Shabila Nazar P. , Aziz Aram Jalal
Published: June 2021

Background

During infectious disease outbreaks, healthcare workers are at high risk of infection, infecting others, and psychological distress. This study aimed to determine the prevalence of stress and anxiety in physicians during the COVID-19 outbreak in the Iraqi Kurdistan Region and assess their associated factors.

Methods

This cross-sectional study was carried out in Erbil, Iraqi Kurdistan Region, from March 28 to April 15, 2020. An online self-administered survey questionnaire was used to collect data from physicians working in specialized COVID-19 centers and other healthcare facilities. The level of stress was measured based on the 10-items Perceived Stress Scale. The level of anxiety was measured based on the 7-item Generalized Anxiety Disorder scale.

Results

A total of 370 participants responded to the perceived stress component of the survey, of whom 57 (15.4%) had low perceived stress, 249 (67.3%) had moderate stress, and 64 (17.3%) had high stress. Being female was significantly associated with having moderate/high stress (adjusted odds ratio (AOR) = 2.40 (95% CI 1.31–4.39)). A total of 201 participants responded to the generalized anxiety disorder component of the survey, of whom 19 (9.5%) had no anxiety, 57 (28.4%) had mild anxiety, 79 (39.3%) had moderate anxiety, and 46 (22.9%) had severe anxiety. Working in COVID-19 centers (AOR = 2.23 (95% CI 1.02–4.86)) and being general practitioners (AOR = 4.16 (95% CI 1.14–15.14)) were significantly associated with having moderate/severe anxiety.

Conclusion

A considerable proportion of physicians experience stress and anxiety during the COVID-19 outbreak in Iraqi Kurdistan region. Generalists and those in special COVID-19 units report the greatest anxiety. There a need to establish mechanisms to reduce the risks of stress and anxiety among physicians. Mental health coping interventions through counseling should be based on COVID-19 protocol guidelines. Interventions should also emphasize physicians’ ability to work safely and efficiently in providing care to the patients.
Assessment of early COVID-19 compliance to and challenges with public health and social prevention measures in the Kingdom of Eswatini, using an online survey
Authors: Padidar Sara , Liao Shell-may , Magagula Siphesihle , Mahlaba Themb’a A. M. , Nhlabatsi Nhlanhla M. , Lukas Stephanie
Published: June 2021

Public health and social measures have been implemented around the world in a bid to prevent the spread of COVID-19. Public compliance with these measures is key in successfully controlling the pandemic. This online survey assessed the compliance and attitude of adults residing in the southern African Kingdom of Eswatini to government protection, activity and travel measures aimed at controlling the spread of COVID-19. A rapid online survey, comprising of 28 questions, was administered in May 2020. More than 90% of respondents knew the virus could kill anyone and most respondents (70%) reported to be compliant to public health and social measures. Females, those who did not use public transport and those aged 30 years and above were significantly (p<0.01) more compliant, particularly to protective and travel measures. Social media, television and official government websites were the primary source of ongoing COVID-19 information for respondents of this online survey, and these methods should continue to be employed to reach the public who regularly use the internet. More than half of essential workers who responded to the online survey reported to have their own personal protective equipment; however, 32% either did not have any protective equipment or shared their equipment with other staff members. Due to the survey being online, these results should not be generalised to populations of low socioeconomic status.
Rosalía’s kaleidoscope in the crossroads of late modernity
Authors: Alvarez-Cueva Priscila , Guerra Paula
Published: June 2021

Rosalía gained worldwide fame with the release of El Mal Querer in 2018, carving a niche for herself in mainstream music with her distinctive aesthetic style and the incorporation of flamenco rhythms in her music. Our study aims to analyse four of her most important songs to highlight how she created her artistic place by incorporating collective cultural memories and translating them into a late modern scenario while at the same time commodifying the working-class standard of choni women in Spain. Our main findings suggest that (1) Rosalía’s work appropriates certain cultural and collective memories and translates them into a fashionable and desirable late modern lifestyle that combines a flamenco sound with other rhythms that could lead to the sustenance of this music genre in the new generations; (2) Rosalía establishes her youth style and femininity by incorporating a set of consumer practices that are also guided by elements of the postfeminist sensibility; and (3) there are four main actions that helped Rosalía to establish the choni-chic style. With this combination, we argue that Rosalía brings to the present a hybridized flamenco for contemporary generations while also rescuing cultural and patrimonial elements that are relevant within the construction of identities.
The use of user-generated comments and their effects on the perception of news: An experimental study
Authors: Awobamise Ayodeji O. , Jarrar Yosra
Published: June 2021

A review of literature suggests that very few studies have examined how selection, deletion and inclusion of comments in news articles affect audience perception of news credibility, newsworthiness and trustworthiness. Using an experimental methodology, this study seeks to understand how journalistic use of UGCs influences audience perception of news credibility, newsworthiness and trustworthiness. The study also sought to espouse on the two-step flow theory and its relevance to online media; with particular reference to news selection. Four hundred participants from selected Nigerian universities constitute the sample of this study and the findings showed that comments use influenced audience perception of news credibility, newsworthiness and trustworthiness. Also, the findings lent credence to developing research that seeks to prove that the two-step flow story is relevant to online media. The findings of this study showed evidence of the two-step flow of information.
The paradox of pluralism: A key to interpreting the online public sphere in the time of ‘encastellation’
Authors: Giacomini Gabriele
Published: June 2021

This viewpoint makes a theoretical effort to label the organization of the virtual sphere under new concepts: ‘encastellation’ and the ‘paradox of pluralism’. The former is a metaphorical synthesis of already-known concepts (selective exposure, polarization, homophily, echo chambers and filter bubbles). In the second case, we emphasize the existence of a ‘paradox of online pluralism’: the internet has increased the possibility for everyone to make their voice heard (in quantitative terms), but at the same time it appears to also be increasing the distance between voices, putting in jeopardy the achievement of the aims of the pluralist political system (in qualitative terms). In conclusion, we express doubts about the feasibility of the deliberative vision of democracy in the current virtual sphere.
Expression of recombinant 35 kDa fragment of VP2 protein of canine parvovirus using Escherichia coli expression system
Authors: Inthong Natnaree , Kaewmongkol Sarawan , Meekhanon Nattakan , Suwan Eukote , Sricharern Wanat , Satchasataporn Khomson , Sinsiri Rungthiwa , Sirinarumitr Kaitkanoke , Sirinarumitr Theerapol
Published: June 2021

Background and Aim: Canine parvovirus (CPV) is one of the most common viral infections in dogs, causing acute hemorrhagic gastroenteritis and high mortality. Vaccination effectively prevents CPV infection. However, the currently available CPV vaccines have concerns such as maternal immunity interference, shedding of virus vaccine, and false-positive result based on polymerase chain reaction after vaccination. A subunit vaccine can overcome these problems. This study aimed to express the recombinant 35 kDa fragment of the VP2 protein (consisting of epitopes 1-7) and the recombinant full-length VP2 protein (consisting of epitopes 1-10) and to study the ability of these two recombinant proteins to react with rabbit anti-CPV polyclonal antibodies.

Materials and Methods: The full length and 35 kDa fragment of VP2 gene of CPV were cloned into the pBAD202 Directional TOPOTM expression vector and expressed in E. coli. The recombinant full-length and the recombinant 35 kDa fragment proteins of VP2 were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting.

Results: The recombinant full-length and the recombinant 35 kDa fragment VP2 genes were successfully cloned and expressed. The optimum concentrations of arabinose and induction time for the recombinant full-length and the recombinant 35 kDa fragment VP2 proteins were 0.2% for 6 h and 0.02% for 6 h, respectively. The recombinant full-length and the recombinant 35 kDa fragment VP2 protein molecular weights were approximately 81 and 51 kDa, respectively. The recombinant full-length and the recombinant 35 kDa fragment VP2 proteins specifically interacted with rabbit anti-CPV polyclonal antibodies.

Conclusion: These results suggest that the recombinant 35 kDa fragment and the recombinant full-length VP2 proteins may be useful in developing a CPV diagnostic test or vaccine.
Effect of Pulsed 810 nm Laser Photobiomodulation on Dermal Wound Healing and Oxidative Stress in Immunosuppressed Rats
Authors: Keshri Gaurav K. , Verma Saurabh , Gupta Asheesh
Published: June 2021

Under immunosuppression, the sequential overlapping wound repair phases get hampered due to dysregulated or persistent inflammation leading to non-healing chronic wounds formation. The present study investigates the effect of low-power 810 nm diode laser (70 mW mean output power; 40 mW/cm2 average irradiance; 24 J/cm2 total fluence; 10 Hz pulse frequency; duty cycle 50 per cent; 10 min. illumination time once daily for seven days) photobiomodulation (PBM) on dermal penetration ability, wound healing and oxidative stress in hydrocortisone-induced immunosuppressed rats. The results of the penetration ability of 810 nm laser irradiation to the depth of the sub-dermal region revealed that the transmitted power of laser at 10 Hz pulsed-mode was better and easier than continuous-mode. The present findings clearly delineated that PBM with 810 nm laser at 10 Hz significantly augmented healing and reduced oxidative stress as evidenced by decreased free radicals, nitric oxide (NO) levels, enhanced superoxide dismutase (SOD) enzyme activity and wound area contraction facilitating the cellular redox homeostasis and promoting the tissue repair process. In conclusion, PBM with NIR 810 nm laser at pulsed-mode 10 Hz frequency showed better penetration and accelerated dermal wound healing in immunosuppressed rats.
Role of H2S Supplementation on Burn Wound Healing and Molecular Chaperones
Authors: Verma Saurabh , Keshri Gaurav K. , Sharma Manish , Gupta Asheesh
Published: June 2021

Treatment of non-healing burn injuries is a major challenge for the current scientific research. Hydrogen sulfide (H2S) is an endogenous gasotransmitter, which regulates redox homeostasis and cytoprotection during pathophysiological conditions. Similarly, heat shock proteins (HSPs) are molecular chaperones, which also confer cytoprotection during the wound repair process. Notably, the role of H2S as a regulator of HSPs during burn wound healing is still elusive. The present study investigated the effects of H2S supplementation on molecular chaperones during full-thickness, third-degree burn wound healing in the experimental rats. The animals were treated with sodium hydrosulphide (NaHS) as H2S donor (5 mg/kg body weight, intraperitoneal) daily for 10 days prior to burn-induction and continued till the fifth-day post-wounding. Histopathological analysis (Masson’s trichrome) revealed enhanced wound healing evident by increased collagen fiber deposition, cellular proliferation and re-epithelialisation in NaHS administered group as compared to the burn control. Furthermore, immunoblot analyses demonstrated significantly increased protein expression of molecular chaperons viz. HSP90, HSP70, HSP27, and GRP78 in H2S treated group as compared to control. Therefore, the present study signifies that H2S supplementation upregulates the protein expression levels of molecular chaperones, which could facilitate the cytoprotection during the tissue repair process and accelerates the burn wound healing.
The versatility of external quality assessment for the surveillance of laboratory and in vitro diagnostic performance: SARS-CoV-2 viral genome detection in Austria
Authors: Buchta Christoph , Camp Jeremy V. , Jovanovic Jovana , Chiba Peter , Puchhammer-Stöckl Elisabeth , Mayerhofer Maximilian , Plicka Helga , Lercher Alexander , Popa Alexandra M. , Endler Lukas , Bergthaler Andreas , Huf Wolfgang , Benka Bernhard , Delatour Vincent , Müller Mathias M. , Griesmacher Andrea , Aberle Stephan W. , Görzer Irene
Published: June 2021

Objectives

External quality assessment (EQA) schemes provide information on individual and general analytical performance of participating laboratories and test systems. The aim of this study was to investigate the use and performance of SARS-CoV-2 virus genome detection systems in Austrian laboratories and their preparedness to face challenges associated with the pandemic.

Methods

Seven samples were selected to evaluate performance and estimate variability of reported results. Notably, a dilution series was included in the panel as a measure of reproducibility and sensitivity. Several performance criteria were evaluated for individual participants as well as in the cohort of all participants.

Results

A total of 109 laboratories participated and used 134 platforms, including 67 different combinations of extraction and PCR platforms and corresponding reagents. There were no false positives and 10 (1.2%) false negative results, including nine in the weakly positive sample (C

t
∼35.9, ∼640 copies/mL). Twenty (22%) laboratories reported results of mutation detection. Twenty-five (19%) test systems included amplification of human RNA as evidence of proper sampling. The overall linearity of C

t
values from individual test systems for the dilution series was good, but inter-assay variability was high. Both operator-related and systematic failures appear to have caused incorrect results.

Conclusions

Beyond providing certification for participating laboratories, EQA provides the opportunity for participants to evaluate their performance against others so that they may improve operating procedures and test systems. Well-selected EQA samples offer additional inferences to be made about assay sensitivity and reproducibility, which have practical applications.
Using body temperature and variables commonly available in the EHR to predict acute infection: a proof-of-concept study showing improved pretest probability estimates for acute COVID-19 infection among discharged emergency department patients
Authors: Berdahl Carl T. , Nguyen An T. , Diniz Marcio A. , Henreid Andrew J. , Nuckols Teryl K. , Libby Christopher P. , Pevnick Joshua M.
Published: June 2021

Objectives

Obtaining body temperature is a quick and easy method to screen for acute infection such as COVID-19. Currently, the predictive value of body temperature for acute infection is inhibited by failure to account for other readily available variables that affect temperature values. In this proof-of-concept study, we sought to improve COVID-19 pretest probability estimation by incorporating covariates known to be associated with body temperature, including patient age, sex, comorbidities, month, and time of day.

Methods

For patients discharged from an academic hospital emergency department after testing for COVID-19 in March and April of 2020, we abstracted clinical data. We reviewed physician documentation to retrospectively generate estimates of pretest probability for COVID-19. Using patients’ COVID-19 PCR test results as a gold standard, we compared AUCs of logistic regression models predicting COVID-19 positivity that used: (1) body temperature alone; (2) body temperature and pretest probability; (3) body temperature, pretest probability, and body temperature-relevant covariates. Calibration plots and bootstrap validation were used to assess predictive performance for model #3.

Results

Data from 117 patients were included. The models’ AUCs were: (1) 0.69 (2) 0.72, and (3) 0.76, respectively. The absolute difference in AUC was 0.029 (95% CI −0.057 to 0.114, p=0.25) between model 2 and 1 and 0.038 (95% CI −0.021 to 0.097, p=0.10) between model 3 and 2.

Conclusions

By incorporating covariates known to affect body temperature, we demonstrated improved pretest probability estimates of acute COVID-19 infection. Future work should be undertaken to further develop and validate our model in a larger, multi-institutional sample.
In and Out of Self-Employment, Are You Really an Entrepreneur: The Rise of a New Division?
Authors: Hussein Hiba Maher , Haj Youssef Moustafa Salman
Published: June 2021

This paper examines self-employed individuals in the UK Labour market. We use an amalgamated dataset, the British Household Panel Survey, from the years 1991 to 2008, and its successor the United Kingdom Longitudinal Study, from years 2010 to 2014, following 11,657 respondents in the UK for 23 years. We explore the characteristics of different self-employed groups and create a new division that differentiates those who sustain in self-employment from those who move between self-employment and employee jobs. The sample size consists of 1146 sustained self-employed, 1149 dabbled self-employed and 9362 paid workers. We found that dabblers exhibit unique set of attributes that place them in a distinct position compared to sustained self-employed and/or employees. Dabblers seem to be ‘pulled’ rather than ‘pushed’ into self-employment, reflecting a labour market ‘power’ instead of deficiency. Thus, bringing key insight into a group who have not been separately identified in the labour market to date, the self-employed dabblers.
Microstructure and mechanical properties of 2060 Al–Li alloy welded by alternating current cold metal transfer with high-frequency pulse current
Authors: Wang Liwei , Hu Huan , Yan Huan , Liu Ying , Wu Ziqin , Narayanaswamy Balaji , Liang Zhimin , Wang Dianlong
Published: June 2021

Al–Li alloy has been widely used in the aerospace field owing to its high strength and low density. In this study, alternating current cold metal transfer (AC CMT) along with a high-frequency pulse current technique was used to weld a 2060 Al–Li alloy using an ER5356 wire. The effect of pulse frequency on the arc shape, microstructure, and mechanical properties of the welded joints was examined, and mechanical performance testing was conducted. The results revealed that the arc diameter, arc length, and arc volume showed a trend of increasing first and then decreasing with an increase in the pulse frequency and reached their peak values when the pulse frequency was 50 kHz. Coupling the welding process with a high-frequency pulse resulted in grain refinement, which was attributed to the stirring action of the arc force. Both the porosity levels and grain size decreased with increasing frequency. When the pulse frequency was 70 kHz, the porosity level was the lowest, and the grain size was refined to 24.1 μm. The tensile strength of the welded joints also increased with the pulse frequency, and a maximum tensile strength of 249 MPa was observed at 70 kHz.
Neonatal maple syrup urine disease in China: two novel mutations in the BCKDHB gene and literature review
Authors: Jiang Hong‐Hua , Guo Yan , Shen Xian , Wang Ying , Dai Ting-Ting , Rong Hui , Cheng Rui , Zhao Fei
Published: June 2021

Objectives

To report two novel mutations in the BCKDHB gene with Maple syrup urine disease (MSUD) and compare their data with 52 cases of MSUD reported in the available Chinese literature.

Methods

Clinical data of a case of a newborn with MSUD was retrospectively studied. Literatures on MSUD in the local medical journals from January 1990 till December 2019 in China were reviewed.

Results

Two novel BCKDHB mutations c.90_91insCTGGCGCGGGG (p.Phe35TrpfsTer41) and c.80_90del (p.Ala32PhefsTer48) were identified. We found a total of 52 cases of MSUD reports so far. A total of 49 cases had the symptom of poor feeding (94.2%), 50 cases showed poor responses to stimulation (96.2%), 21 cases had odor of maple syrup (40.3%), 29 cases had seizures (55.7%), and 13 cases had respiratory failure (25.0%). The average of the blood ammonia was 127.2 ± 75.0 μmol/L. A total of 18 cases reported the gene testing, among of them 9 cases of BCKDHA mutations, 6 cases of BCKDHB mutations, and 2 cases of DBT mutations. A total of 13 cases (25%) were treated with mechanical ventilation, 50 cases (96.2%) with protein-restricted diet and l-carnitine, 29 cases with thiamine, and only 2 cases were treated with blood purification. Finally, 19 patients (36.5%) were died, 21 cases (40.4%) were improved after treatments.

Conclusions

The clinical phenotype of neonatal MSUD in China belongs to the classical type currently. Suspected patients should have blood or urine branched-chain amino acid levels tested and brain MRI as early as possible to enable early diagnosis, thus improvement in prognosis.
Crystal structure of methyl 2-(1H-naphtho[1,8-de][1.3.2]diazaborinin-2(3H-yl)benzoate C18H15BN2O2
Authors: Song Wenqi , Miao Zongcheng
Published: June 2021

C18H15BN2O2, monoclinic, C2/c (no. 15), a = 23.976(3) Å, b = 7.7690(9) Å, c = 32.940(4) Å, β = 95.17(1)°, V = 2482.26(15) Å3, Z = 4, R

gt
(F) = 0.0525, wR

ref
(F
2) = 0.1415, T = 193 K.
The crystal structure of bis[4-bromo-2-(1H-pyrazol-3-yl) phenolato-κ2
N,O] copper(II), C18H12Br2CuN4O2
Authors: Jaćimović Željko K. , Tomić Zoran D. , Giester Gerald , Libowitzky Eugen , Ajanović Atifa , Kosović Milica
Published: June 2021

C18H12Br2CuN4O2, monoclinic, P21/c (no. 14), a = 11.5165(11) Å, b = 5.4369(5) Å, c = 14.4872(14) Å, V = 873.52(14) Å3, Z = 2, R

gt
(F) = 0.0232, wR

ref
(F
2) = 0.0559, T = 200 K.
Carbonyl pigments: General principles
Authors: Christie Robert , Abel Adrian
Published: June 2021

This chapter describes the general features of the chemical class of pigments designated as carbonyl pigments. These pigments are characterized by the presence of carbonyl groups linked to one another via an extended conjugated system, often forming polycyclic aromatic structures. Carbonyl pigments have experienced distinct phases in their histories. Certain carbonyl colorants, notably anthraquinonoids, were discovered in the early twentieth century and subsequently used as vat dyes for textiles, but their potential as high-performance pigments was not realized until the mid-twentieth century when demand began to emerge for pigments of the quality that they could provide. After conversion to a suitable physical form, several vat dyes were then introduced as vat pigments. Several other carbonyl pigment types did not originate as vat dyes but were developed specifically for pigment use. Carbonyl pigments provide a wider diversity of structural arrangements. The broad carbonyl chemical class may be categorized into several sub-types, each with its own characteristic structural features. These categories, which are discussed in separate chapters, include anthraquinonoids, quinacridones, diketopyrrolopyrroles, perylenes, perinones, indigoids, isoindolines, isoindolinones, and quinophthalones. These products generally owe their high levels of technical performance to their large molecular size and high molecular planarity, which lead to highly compact crystal structures and, in many cases, to the ability of the carbonyl group to participate in strong intra- and intermolecular hydrogen bonding.
Phthalocyanine pigments: general principles
Authors: Christie Robert , Abel Adrian
Published: June 2021

This chapter describes some of the fundamental chemical and structural principles underlying the phthalocyanine system. Historically, phthalocyanines had been isolated as insoluble blue products in the early twentieth century, although the structures were not established at the time. After the serendipitous re-discovery of metal complex phthalocyanines by industry, and the elucidation of their structures, copper phthalocyanine (CuPc) pigments were introduced industrially in the 1930s to become, and remain, by far the most important blue and green organic pigments, finding almost universal use as colorants for paints, printing inks, plastics, and a wide range of other applications. The phthalocyanines have become one of the most extensively studied classes of organic compounds, because of their unique molecular structures, light absorption properties that produce strong, bright colors, and their exceptionally high stability. While their dominant use is as colorants, they are also of interest for a range of other applications, for example in electronic devices, biological applications, and as catalysts.
Nonlinear forced vibration of rotating composite laminated cylindrical shells under hygrothermal environment
Authors: Li Xiao , Jiang Wentao , Chen Xiaochao , Zhou Zhihong
Published: June 2021

This work aims to study nonlinear vibration of rotating composite laminated cylindrical shells under hygrothermal environment and radial harmonic excitation. Based on Love’s nonlinear shell theory, and considering the effects of rotation-induced initial hoop tension, centrifugal and Coriolis forces, the nonlinear partial differential equations of the shells are derived by Hamilton’s principle, in which the constitutive relation and material properties of the shells are both hygrothermal-dependent. Then, the Galerkin approach is applied to discrete the nonlinear partial differential equations, and the multiple scales method is adopted to obtain an analytical solution on the dynamic response of the nonlinear shells under primary resonances of forward and backward traveling wave, respectively. The stability of the solution is determined by using the Routh–Hurwitz criterion. Some interesting results on amplitude–frequency relations and nonlinear dynamic responses of the shells are proposed. Special attention is given to the combined effects of temperature and moisture concentration on nonlinear resonance behavior of the shells.
“It’s Never Too Late”: High School Counselors’ Support of Underrepresented Students’ Interest in STEM
Authors: Cabell Autumn L. , Brookover Dana , Livingston Amber , Cartwright Ila
Published: June 2021

The purpose of this study was to contribute to the literature surrounding school counselors and their support of underrepresented high school students who are interested in science, technology, engineering, and math (STEM). The influence of context on school counseling was also explored, in particular practicing during the COVID-19 pandemic. Through this phenomenological study, nine high school counselors were individually interviewed, and four themes emerged. These themes were: (a) professional knowledge surrounding issues of diversity in STEM, (b) training related to the needs of underrepresented students in STEM, (c) active engagement in supporting underrepresented students’ STEM career interests, and (d) barriers related to supporting underrepresented students’ STEM interests. This article includes implications for (a) how school counselors can support underrepresented students’ STEM interests, particularly during the COVID-19 pandemic; (b) how counselor educators can contribute to STEM-related research and training; and (c) how school administrators can support school counselors’ STEM initiatives.