bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial resistance—is wound care prepared?
Authors: Bradley Peter
Published: December 2020

In an Essity-sponsored symposium, entitled ‘Antimicrobial resistance—is wound care prepared?’, four key opinion leaders discussed the difficult journey to managing antimicrobial resistance within wound care at the global and local levels, backed up by the latest research. Peter Bradley summarises the main points they presented at the EWMA 2020 Virtual Conference.

This article offers an introduction to the symposium, Antimicrobial resistance—is wound care prepared?, held on 18 November 2020, as part of the EWMA 2020 Virtual Conference. There were four speakers. Claire Kilpatrick, Director, S3 Global and Consultant to the World Health Organization, spoke on ‘Preventing infections and managing antibiotic use—tackling a crisis for the health of nations’. The topic of Karen Ousey, Professor of Skin Integrity, Director for the Institute of Skin Integrity and Infection Prevention, University of Huddersfield, was ‘Antimicrobial stewardship in wound management—less words more action’. Finally, Hadar Lev-Tov, Assistant Professor, and Irena Pastar, Associate Professor, both of the Dr Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami, gave a talk on ‘Silver-resistant bacteria in venous leg ulcers? First results of an exploratory study’.
Use of a biosynthetic wound dressing to treat burns: a systematic review
Authors: Rahimi Farimah , Rezayatmand Reza
Published: December 2020

Objective:

Accelerating the process of wound healing, reducing infection risks, and decreasing pain and discomfort in the burn area are important goals of burn treatment. To achieve these goals, the use of biosynthetic wound dressings has increased in recent years. Suprathel (PolyMedics Innovations, Germany) is a biosynthetic wound dressing used to treat both partial-thickness burns and split-thickness skin graft (STSG) donor sites, full-thickness wounds, large-scale abrasions, and scar revisions.

Method:

This study is a systematic review of empirical evidence reported on the application of the biosynthetic wound dressing in burns up to 2017. Keywords such as ‘Suprathel’, ‘effectiveness’, ‘safety’, and ‘cost’ were searched in PubMed, Cochrane, Scopus and Embase databases.

Results:

A total of 14 publications were identified, based on the inclusion and exclusion criteria. The findings reported in the literature reviewed were classified in terms of safety, effectiveness and cost-effectiveness of use of the biosynthetic wound dressing. Regarding safety and effectiveness, the dressing was found to yield desirable results, particularly for partial thickness burns and STSG donor sites. As of 2017 no health economics assessments have been carried out.

Conclusion:

Despite the desirable advantages of the biosynthetic wound dressing with respect to its effectiveness, safety and ease of use, its major limitation was found to be its cost. However, in the absence of comprehensive studies on the quantification of all factors, there is scant scientific evidence for making reliable conclusions from this systematic review.
Effects of resveratrol on the growth and enzyme production of Stenotrophomonas maltophilia: a burn wound pathogen
Authors: Bharadwaj Sraddha S. , Vaidyanathan Lalitha
Published: December 2020

Objective:

The purpose of this study was to identify the potential of resveratrol in inhibiting the growth and production of two enzymes, hyaluronidase and protease, in Stenotrophomonas maltophilia, which has become a burn wound pathogen of great significance.

Method:

Stenotrophomonas maltophilia (ATCC 17666) was cultured in nutrient broth and the microbial load was standardised to 0.5 McFarland standard at 600nm. The study included antimicrobial assays (well diffusion and resazurin dye binding method), hyaluronidase expression regulation assay (hyaluronic acid hydrolysis assay and turbidity assay) and protease expression regulation assay (casein hydrolysis assay and determination of specific activity of protease using tyrosine standard).

Results:

The minimum inhibitory concentration (MIC) of resveratrol against Stenotrophomonas maltophilia was found to be 125µg/ml. Hyaluronidase production in the organism treated with resveratrol was found to be half that in the untreated organism. The specific activity of protease produced by the organism treated with resveratrol was found to be one-quarter that in the untreated organism, as analysed by the tyrosine standard estimation protocol.

Conclusion:

Resveratrol was found to be a potent compound to treat Stenotrophomonas maltophilia infections. In addition to the antimicrobial and enzyme-regulatory properties of resveratrol, it also shows anti-oxidant and anti-inflammatory properties. This finding has great scope clinically as resveratrol may prove to be an ideal drug to treat burn wound infections.
Plastic and Elastic Strains in Poplar Wood under High-Pressure Densification
Authors: Li Aqiang , Yan Kaiya , Ramaswamy Hosahalli S. , Zhu Songming , Yu Yong
Published: December 2020

Highlights

High-pressure densification (HPD) resulted in more than 100% increase in the density of poplar wood.

Density of wood during HPD treatment was up to 300% and 100% higher than observed before and after HPD.

A method was developed to measure elastic recovery in the radial and tangential directions under HPD.

Abstract. Plastic and elastic strains of poplar wood in the radial and tangential directions were investigated after high-pressure densification (HPD) using a special method that detected the elastic strain. There was a large difference in plastic and elastic strains obtained in compressed wood between the radial and tangential directions. The maximum total strain in the radial and tangential directions reached 26.9% and 66.9%, respectively, when compressed at 150 MPa for 300 s. Longer holding time (300 s) increased the plastic strain, by reducing the elastic strain, when the applied pressure was lower than 60 MPa. In addition, a large difference in compressed wood density prevailed when still under pressure as compared with the density measured after the pressure treatment, and both were nearly 1 to 3 times higher than the density of fresh wood. Further, the maximum density observed under pressure was related to the maximum reported density of dry crystalline cellulose plus the entrapped moisture. The mechanical properties of densified wood were also investigated and found to depend on the pressure treatment conditions. Keywords: Elastic strain, High-pressure densification, Mechanical properties, Plastic strain, Wood density.
Utilização de benzodiazepínicos em Estratégias Saúde da Família
Authors: Reis e Souza Janaina Ketelly , Pereira Alarcon Patricia , De Mattos Magda , Souza Castro Ludiele
Published: December 2020

Introdução: Alterações de humor, ansiedade e insônia são os transtornos mentais que mais acometem a população, sendo identificadas com maior frequência na Atenção Primária à Saúde. Para o tratamento desses transtornos, é comum a prescrição de benzodiazepínicos. Objetivo: Quantificar e estabelecer o perfil de utilização de benzodiazepínicos na população adultade duas unidades de Estratégia Saúde da Família em município do Mato Grosso. Métodos: Os dados foram coletados em prontuários que continham registro de uso de psicotrópicos, durante o ano de 2018. Resultados: Foram encontrados 164 pacientes em uso de benzodiazepínicos, dos quais, 82,9% (n=136) eram mulheres. A associação de benzodiazepínicos com outros psicotrópicos representou 66,5%, sendo a amitriptilina a mais prescrita (35,8%). Com relação ao tempo de uso foi observado que a maioria dos pacientes faz uso há mais de 6 meses (93,0%). O clonazepam foi o benzodiazepínico mais prescrito, com 70,7% (n=116) dos registros de uso, nos prontuários. A Dose Diária Definida (DDD) de clonazepam resultou em 3,19 DDD/1.000hab./dia, quando se utiliza a DDD de 8mg, e 25,57 DDD/1.000hab./dia com DDD de 1mg. Conclusão: O uso crônico de benzodiazepínicos em unidades daEstratégia Saúde da Família se mantém como problema de saúde pública, sendo que o acompanhamento adequado destes pacientes é necessário para evitar o uso indiscriminado. Além disso, intervenções que visem proporcionar melhor qualidade de vida aos usuários destes medicamentos devem ser incentivadas.  Introduction: Mood swings, anxiety and insomnia are the most common mental disorders that affect the population and are most frequently identified in Primary Health Care. For the treatment of these disorders, it is common to prescribe benzodiazepines. Objective: Quantify and establish the profile of benzodiazepine use in the adult population of two units of the Family Health Strategy in a municipality in Mato Grosso. Methods: Data were collected from medical records that contained a record of psychotropic use during 2018. Results: Of the 164 patients using benzodiazepines found, 82.9% (n=136) were women. The association of benzodiazepines with other psychotropics represented 66.5%, with amitriptyline being the most prescribed (35.8%). Regarding the duration of benzodiazepine use, it was observed that most patients have been using it for more than 6 months (93.0%). Clonazepam was the most prescribed, with 70.7% (n=116) of the records of use in the medical records. The Defined Daily Dose (DDD) of clonazepam resulted in 3.19 DDD/1,000hab/day, when using DDD 8mg, and 25.57 DDD/1,000hab/day with DDD of 1mg. Conclusion: The chronic use of benzodiazepines in the Family Health Strategy Unitsremains as apublic health problem, and adequate monitoring of these patients is necessary to avoid indiscriminate use. In addition, interventions aimed at providing a better quality of life to users of these drugs should be encouraged.
ASSESSMENT OF THE FREQUENCY OF FOOD PRODUCTS CONSUMPTION AND DIETARY SUPPLEMENTS BY MILITARY AVIATION PERSONNEL DEPENDING ON THEIR NUTRITIONAL KNOWLEDGE
Authors:   Laboratory of Dietetics and Obesity Treatment, Department of Psychophysiological Measurements and Human Factor Research, Military Institute of Aviation Medicine, Gaździńska Agata , Turczyńska Marta ,   Laboratory of Dietetics and Obesity Treatment, Department of Psychophysiological Measurements and Human Factor Research, Military Institute of Aviation Medicine, Jagielski Paweł ,   Department of Nutrition and Drug Research, Faculty of Health Science, Jagiellonian University, Medical College
Published: December 2020

Introduction: Nutritional behaviour is the result of many factors, one of which is nutritional knowledge. A higher level of nutritional knowledge promotes proper nutrition, which is the main factor influencing health, nutritional status and psychophysical efficiency. The aim of the study was to determine the customary frequency of consumption of selected food products and dietary supplements by Air Force soldiers depending on their level of nutritional knowledge. Methods: The study was carried out among 540 Air Force soldiers and 498 persons with complete data (32 women, 466 men; mean age 36.3±8.5 years) were included in the analysis. The FFQ food consumption frequency questionnaire was used to assess the frequency of food consumption. Nutrition knowledge was assessed on the basis of 32 statements on food and nutrition. Results: The level of nutritional knowledge depended significantly on the education and age of the respondents. In the group of the surveyed soldiers, military pilots showed the highest level of nutritional knowledge, while the lowest level was shown by engineering and aviation services. The frequency of consumption of milk and natural dairy drinks, curds, eggs, wholemeal bread, coarse groats, fruits, vegetables, oils, nuts, seeds, poultry meat, rabbit meat, honey, wine and drinks increased significantly with the increase in the level of nutritional knowledge, while the frequency of consumption of margarines in cubes, margarines in cups, animal fats and cured meats decreased. Dietary supplements such as vitamin, mineral and vitamin-mineral preparations were significantly more frequently consumed by soldiers with a higher level of nutritional knowledge. Conclusions: 1. On the basis of the assessment of the frequency of consumption of products, a number of abnormalities were found among the majority of the surveyed soldiers of military aviation personnel. 2. The results obtained confirm that a higher level of nutritional knowledge promotes healthy eating habits among the Air Force soldiers. Food education is essential, especially among soldiers in the older age group and ground flying personnel
PHYSIOLOGICAL CORRELATES OF ALMOST LOSS OF CONSCIOUSNESS (A-LOC) DURING DYNAMIC FLIGHT SIMULATION (DFS) ON HUMAN CENTRIFUGE: A CASE REPORT
Authors:   Creative Neuroscience Lab – CNS Lab, Military Institute of Aviation Medicine, Przewodzka Anna , Gaździński Stefan P. ,   Creative Neuroscience Lab – CNS Lab, Military Institute of Aviation Medicine, Janewicz Michał ,   Department of Simulator Studies and Aeromedical Training, Military Institute of Aviation Medicine, Kowalczuk Krzysztof ,   Department of Simulator Studies and Aeromedical Training, Military Institute of Aviation Medicine
Published: December 2020

Introduction: G-LOC is still a threat for aircrew of high performance aircrafts. It is evoked by a high level of +Gz acceleration causing a deficit of brain oxygenation. Although near-infrared spectroscopy (NIRS) was used to identify brain oxygenation decreases preceding G-LOC, it is not used regularly in aero-medicine research in Poland. Here, we report the physiological correlates of Almost Loss of Consciousness (A-LOC) that occurred during a research project. Method: During Dynamic Flight Simulation training on a human centrifuge one pilot experienced momentaneous confusion which was recorded on a camera. We post-hoc reviewed his vital signs, stroke volumes (SV), cardiac output (CO) obtained with bioimpedance rheography, and brain oxygenation (OX) measures with near-infrared spectroscopy on the forehead. Finally, we reviewed the recording of his eye movements obtained with video-oculography. Results: SV and CO measures were confounded by artefacts induced by anti-G straining manoeuvres (AGSM). However, OX measures demonstrated decreased brain oxygenation that lasted several seconds after the incident. Following the incident, the pilot’s pulse remained decreased for several seconds. Discussion: NIRS methodology seems to be resistant to artefacts created by muscles during AGSM. NIRS systems with a probing rate of 0.1 second might help detect upcoming A-LOC or G-LOC.
High-order analytical formulation of soliton self-frequency shift
Authors: Kormokar Robi , Shamim Md Hosne Mobarok , Rochette Martin
Published: December 2020

We derive an analytical formulation of the Raman-induced frequency shift experienced by a fundamental soliton. By including propagation losses, self-steepening, and dispersion slope, the resulting formulation is a high-order (HO) extension of the well-known Gordon’s formula for soliton self-frequency shift (SSFS). The HO-SSFS formula agrees closely with numerical results of the generalized nonlinear Schrödinger equation, but without the computational complexity and required computation time. The HO-SSFS formula is a useful tool for the design and validation of wavelength conversion systems and supercontinuum generation systems.
Constitutive equations describing optical activity in theory of dispersion
Authors: Franta Daniel , Vohánka Jiří
Published: December 2020

Landau and Condon formalisms, which are two formalisms used for modeling the dielectric response of materials exhibiting optical activity, are compared. It is shown that the true equivalence between these two formalisms can be established only for isotropic materials. The arguments presented in this work show that from the physical point of view, Landau formalism is preferable since it allows more general dependence on the wave vector, it is easy to ensure conformity with the sum rules and other requirements, and it could be used to model inhomogeneous waves.
Highly efficient 2.3  µm thulium lasers based on a high-phonon-energy crystal: evidence of vibronic-assisted emissions
Authors: Loiko Pavel , Kifle Esrom , Guillemot Lauren , Doualan Jean-Louis , Starecki Florent , Braud Alain , Aguiló Magdalena , Díaz Francesc , Petrov Valentin , Mateos Xavier , Camy Patrice
Published: December 2020

We report on highly efficient and power-scalable laser operation in a thulium-doped high-phonon-energy crystal [monoclinic double tungstate,

K
L
u

(

W
O

4

)
2

] on the

3

H

4

→

3

H

5

T
m

3
+

transition giving rise to the short-wave infrared emission at

∼

2.3

µ

m

. A 3 at. % Tm-doped crystal generated a maximum continuous-wave output power of 1.12 W at

∼

2.22

and 2.29 µm with a record-high slope efficiency of 69.2% (versus the absorbed pump power), a slightly multimode beam (

M

x
,
y

2

=

2.2

and 2.6), and a linear laser polarization. The

∼

2.3

µ

m

laser outperformed the one operating on the conventional

3

F

4

→

3

H

6

transition (at

∼

1.95

µ

m

). The effect of the Tm concentration on the

∼

2.3

µ

m

laser performance indicates a gradually increasing pump quantum efficiency for the

3

H

4

upper laser level with the Tm doping. For the 3 at. % Tm-doped crystal, it reached

1.8

±

0.1

(almost two-for-one pump process), which is attributed to efficient energy-transfer upconversion. We discuss the physical nature of the laser emissions occurring at intermediate wavelengths between the electronic

3

H

4

→

3

H

5

and

3

F

4

→

3

H

6

transitions and highlight the role of electron-phonon coupling (vibronic processes) in the appearance of such laser lines. This allowed us to better understand the near- and mid-infrared emission from thulium ions, which can be used in broadly tunable and fs mode-locked 2–2.3 µm lasers.
In-fiber measurement of the erbium-doped ZBLAN 4I13/2 state energy transfer parameter
Authors: Moffatt Jillian E. , Tsiminis Georgios , Klantsataya Elizaveta , Henderson-Sapir Ori , Smith Barnaby W. , Spooner Nigel A. , Ottaway David J.
Published: December 2020

Erbium-doped ZBLAN (Er:ZBLAN) is a commonly used glass for mid-infrared fiber lasers. Quantifying the energy dynamics of the erbium ions is important for improving the performance of mid-infrared fiber lasers. Previous studies have found a discrepancy between the strength of inter-ion energy transfer measured in bulk Er:ZBLAN and the strength required to explain current fiber laser performance. We have measured the strength of the

4

I

13

/

2

+

4

I

13

/

2

→

4

I

15

/

2

+

4

I

9

/

2

energy transfer process directly in a range of fibers for the first time, to the best of our knowledge.
A simple and robust shade correction scheme for remote sensing reflectance obtained by the skylight-blocked approach
Authors: Yu Xiaolong , Lee Zhongping , Shang Zhehai , Lin Hua , Lin Gong
Published: December 2020

The skylight-blocked approach (SBA) provides a direct and high-precision measurement of the water-leaving radiance (Lw), which allows a confident determination of the remote sensing reflectance (Rrs), where Rrs is defined as the ratio of Lw to the downwelling irradiance just above the surface. However, the Rrs obtained by SBA is subject to self-shading error. The present shade error correction scheme (Shang17, [Appl. Opt. 56, 7033-7040, 2017]), implemented via spectral optimization, encounters large errors if there is a mismatch in the spectral models of the component inherent optical properties (IOPs). Following the concept of the quasi-analytical algorithm (QAA, [Appl. Opt. 41, 5755-5772, 2002]), a novel scheme (ShadeCorrQAA) is proposed without the need to model the component IOPs. Evaluations with numerical simulations and controlled measurements show that ShadeCorrQAA outperforms Shang17 in all water types and can correct the shade impact excellently, even for highly productive waters. ShadeCorrQAA is further improved at the chlorophyll fluorescence band, where a constructed absorption coefficient is used to estimate the shade error. Collectively, ShadeCorrQAA, with higher accuracy and broader applicability than Shang17, is recommended for the shade correction associated with SBA and other similar measurements where there is a shade impact on Rrs.
Fast 3D form measurement using a tunable lens profiler based on imaging with LED illumination
Authors: Agour Mostafa , Fallorf Claas , Bergmann Ralf. B.
Published: December 2020

We present a fast shape measurement of micro-parts based on depth discrimination in imaging with LED illumination. It is based on a 4f-setup with an electrically adjusted tunable lens at the common Fourier plane. Using such a configuration, the opportunity to implement a fast depth scan by means of a tunable lens without the requirement of mechanically moving parts and depth discrimination using the limited spatial coherence of LED illumination is investigated. The technique allows the use of limited spatially partially coherent illumination which can be easily adapted to the test object by selecting the geometrical parameters of the system accordingly. Using this approach, we demonstrate the approach by measuring the 3D form of a tilted optically rough surface and a cold-formed micro-cup. The approach is robust, fast since required images are captured in less than a second, and eye-safe and offers an extended depth of focus in the range of few millimetres. Using a step height standard, we determine a height error of ±1.75 μm (1σ). This value may be further decreased by lowering the spatial coherence length of the illumination or by increasing the numerical aperture of the imaging system.
Electro-optic frequency combs for rapid interrogation in cavity optomechanics
Authors: Long D. A. , Reschovsky B. J. , Zhou F. , Bao Y. , LeBrun T. W. , Gorman J. J.
Published: December 2020

Electro-optic frequency combs were employed to rapidly interrogate an optomechanical sensor, demonstrating spectral resolution substantially exceeding that possible with a mode-locked frequency comb. Frequency combs were generated using an integrated-circuit-based direct digital synthesizer and utilized in a self-heterodyne configuration. Unlike approaches based upon laser locking, the present approach allows rapid, parallel measurements of full optical cavity modes, large dynamic range of sensor displacement, and acquisition across a wide frequency range between DC and 500 kHz. In addition to being well suited to measurements of acceleration, this optical frequency comb-based approach can be utilized for interrogation in a wide range of cavity optomechanical sensors.
Spectrally exclusive phase masks for wavefront coding
Authors: Boher Micke , Jaeck Julien , Bouchon Patrick , Primot Jérôme , Haïdar Riad
Published: December 2020

The use of phase masks is necessary for wavefront coding, and these are often based on optical path differences. However, the optical dispersion constrains the resulting device to operate within a restricted spectral bandwidth. Here we propose to remove this constraint due to sub-wavelength structuration of the surface. The use of spatial and spectral co-localization properties of these structures allows the production of various spectrally exclusive phase masks on the same area.
Integrated optical chip for a high-resolution, single-resonance-mode x-ray monochromator system
Authors: Chang Ying-Yi , Tsai Yi-Wei , Weng Shih-Chang , Chen Shih-Lun , Chang Shih-Lin
Published: December 2020

An integrated optical chip that minimizes the size of the energy-tuning single-resonance-mode x-ray monochromator system into a

3

c
m

×
5

c
m

silicon wafer is proposed. A Fabry–Perot x-ray resonator and two back-reflecting Si mirrors are employed on the wafer as the optical components, where Si(12 4 0) back reflection is used for both Fabry–Perot resonance and re-diffraction of the x-ray beams from the resonator in the incident direction. We can achieve an energy bandwidth of 3.4 meV in single-mode x rays and tune the energy by temperature variation. Such Si chips can be readily employed at the synchrotron beamlines and conventional x-ray laboratories for high-resolution investigations.
Hyperbolic plasmonics with anisotropic gain–loss metasurfaces
Authors: Kuzmin Dmitry A. , Bychkov Igor V. , Shavrov Vladimir G. , Temnov Vasily V.
Published: December 2020

In this Letter, a fundamentally new concept of realization of hyperbolic plasmonic metasurfaces by anisotropic gain–loss competition is proposed, and the possibility of highly directional propagation and amplification of surface plasmon polaritons is predicted. A simple realistic configuration of such a metasurface represents the periodic array of lossy metallic slabs embedded in the gain matrix. Our results may pave the way for numerous applications ranging from integrated and highly directional quantum light emitters to nonlinear-optical frequency converters.
Nanosecond optical parametric oscillator with midinfrared intracavity difference-frequency mixing in orientation-patterned GaAs
Authors: Wang Li , Chen Weidong , Schunemann Peter , Schirrmacher André , Büttner Edlef , Boyko Andrey A. , Ye Ning , Zhang Ge , Zhao Yongguang , Petrov Valentin
Published: December 2020

We report on efficient midinfrared difference-frequency generation (DFG) in orientation-patterned GaAs by intracavity mixing the signal and idler pulses of a narrowband nanosecond optical parametric oscillator based on periodically poled

L
i
N
b

O

3

. The maximum average DFG output power reached 215 mW at 8.15 µm for a repetition rate of 35 kHz. The temperature tuning range spanned over 8026–8710 nm. The maximum overall conversion efficiency from 1 to 8 µm amounted to

∼

1.3

%

.
Abruptly autofocusing circular swallowtail beams
Authors: Teng Houan , Qian Yixian , Lan Yanping , Cai Yiming
Published: December 2020

In this Letter, to the best of our knowledge, we report the first experimental demonstration of a new family of autofocusing beams, circular swallowtail beams (CSBs), based on the high-order swallowtail catastrophe, which were determined by potential functions depending on the state and control parameters. The dynamics of the CSBs is discussed here. These types of CSBs tend to automatically focus without external components. Numerical results showed the focal intensity increased significantly, and it was as much as 110 times in the initial plane when the radius of the main ring was 40. Additionally, in contrast to previous circular Pearcey and Airy beams, these CSBs appeared to have more diversity and tunability due to having more propagation trajectories and intensity distribution structures due to high-order diffraction catastrophe. The numerical simulations were verified by our experimental results. These diverse CSBs could have new applications in flexible optical manipulation. These various CSBs could be beneficial for potential applications in optical trapping, medical treatment, or micromachining.
A sensitive and affordable multiplex RT-qPCR assay for SARS-CoV-2 detection
Authors: Reijns Martin A. M. , Thompson Louise , Acosta Juan Carlos , Black Holly A. , Sanchez-Luque Francisco J. , Diamond Austin , Parry David A. , Daniels Alison , O'Shea Marie , Uggenti Carolina , Sanchez Maria C. , O'Callaghan Alan , McNab Michelle L. L. , Adamowicz Martyna , Friman Elias T. , Hurd Toby , Jarman Edward J. , Chee Frederic Li Mow , Rainger Jacqueline K. , Walker Marion , Drake Camilla , Longman Dasa , Mordstein Christine , Warlow Sophie J. , McKay Stewart , Slater Louise , Ansari Morad , Tomlinson Ian P. M. , Moore David , Wilkinson Nadine , Shepherd Jill , Templeton Kate , Johannessen Ingolfur , Tait-Burkard Christine , Haas Jürgen G. , Gilbert Nick , Adams Ian R. , Jackson Andrew P.
Published: December 2020

With the ongoing COVID-19 (Coronavirus Disease 2019) pandemic, caused by the novel coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), there is a need for sensitive, specific, and affordable diagnostic tests to identify infected individuals, not all of whom are symptomatic. The most sensitive test involves the detection of viral RNA using RT-qPCR (quantitative reverse transcription PCR), with many commercial kits now available for this purpose. However, these are expensive, and supply of such kits in sufficient numbers cannot always be guaranteed. We therefore developed a multiplex assay using well-established SARS-CoV-2 targets alongside a human cellular control (RPP30) and a viral spike-in control (Phocine Herpes Virus 1 [PhHV-1]), which monitor sample quality and nucleic acid extraction efficiency, respectively. Here, we establish that this test performs as well as widely used commercial assays, but at substantially reduced cost. Furthermore, we demonstrate >1,000-fold variability in material routinely collected by combined nose and throat swabbing and establish a statistically significant correlation between the detected level of human and SARS-CoV-2 nucleic acids. The inclusion of the human control probe in our assay therefore provides a quantitative measure of sample quality that could help reduce false-negative rates. We demonstrate the feasibility of establishing a robust RT-qPCR assay at approximately 10% of the cost of equivalent commercial assays, which could benefit low-resource environments and make high-volume testing affordable.
Identification of the critical replication targets of CDK reveals direct regulation of replication initiation factors by the embryo polarity machinery in C. elegans
Authors: Gaggioli Vincent , Kieninger Manuela R. , Klucnika Anna , Butler Richard , Zegerman Philip
Published: December 2020

During metazoan development, the cell cycle is remodelled to coordinate proliferation with differentiation. Developmental cues cause dramatic changes in the number and timing of replication initiation events, but the mechanisms and physiological importance of such changes are poorly understood. Cyclin-dependent kinases (CDKs) are important for regulating S-phase length in many metazoa, and here we show in the nematodeCaenorhabditis elegansthat an essential function of CDKs during early embryogenesis is to regulate the interactions between three replication initiation factors SLD-3, SLD-2 and MUS-101 (Dpb11/TopBP1). Mutations that bypass the requirement for CDKs to generate interactions between these factors is partly sufficient for viability in the absence of Cyclin E, demonstrating that this is a critical embryonic function of this Cyclin. Both SLD-2 and SLD-3 are asymmetrically localised in the early embryo and the levels of these proteins inversely correlate with S-phase length. We also show that SLD-2 asymmetry is determined by direct interaction with the polarity protein PKC-3. This study explains an essential function of CDKs for replication initiation in a metazoan and provides the first direct molecular mechanism through which polarization of the embryo is coordinated with DNA replication initiation factors.
Locus-specific paramutation in Zea mays is maintained by a PICKLE-like chromodomain helicase DNA-binding 3 protein controlling development and male gametophyte function
Authors: Deans Natalie C. , Giacopelli Brian J. , Hollick Jay B.
Published: December 2020

Paramutations represent directed and meiotically-heritable changes in gene regulation leading to apparent violations of Mendelian inheritance. Although the mechanism and evolutionary importance of paramutation behaviors remain largely unknown, genetic screens in maize (Zea mays) identify five components affecting 24 nucleotide RNA biogenesis as required to maintain repression of a paramutantpurple plant1(pl1) allele. Currently, the RNA polymerase IV largest subunit represents the only component also specifying proper development. Here we identify a chromodomain helicase DNA-binding 3 (CHD3) protein orthologous to Arabidopsis (Arabidopsis thaliana) PICKLE as another component maintaining bothpl1paramutation and normal somatic development but without affecting overall small RNA biogenesis. In addition, genetic tests show this protein contributes to proper male gametophyte function. The similar mutant phenotypes documented in Arabidopsis and maize implicate some evolutionarily-conserved gene regulation while developmental defects associated with the two paramutation mutants are largely distinct. Our results show that a CHD3 protein responsible for normal plant ontogeny and sperm transmission also helps maintain meiotically-heritable epigenetic regulatory variation for specific alleles. This finding implicates an intersection of RNA polymerase IV function and nucleosome positioning in the paramutation process.
Bacteriophage activity against and characterisation of avian pathogenic Escherichia coli isolated from colibacillosis cases in Uganda
Authors: Kazibwe George , Katami Phionah , Alinaitwe Ruth , Alafi Stephen , Nanteza Ann , Nakavuma Jesca Lukanga
Published: December 2020

Avian Pathogenic Escherichia coli (APEC) cause colibacillosis leading to significant economic losses in the poultry industry. This laboratory-based study aimed at establishing stocks of avian pathogenic Escherichia coli lytic bacteriophages, for future development of cocktail products for colibacillosis management. The study determined the antibiotic susceptibility; phylogenetic categories, occurrence of selected serotypes and virulence genes among Escherichia coli stock isolates from chicken colibacillosis cases; and evaluated bacteriophage activity against the bacteria. Escherichia coli characterization was done through phenotypic and multiplex PCR methods. Bacteriophage isolation and preliminary characterization was achieved using the spot assay and overlay plating techniques. Fifty-six (56) isolates were phenotypically confirmed as E. coli and all exhibited resistance to at least one antimicrobial agent; while multi-drug resistance (at least three drugs) was encountered in 50 (89.3%) isolates. The APEC isolates mainly belonged to phylogroups A and D, representing 44.6% and 39.3%, respectively; whereas serotypes O1, O2 and O78 were not detected. Of the 56 isolates, 69.6% harbored at least one virulence gene, while 50% had at least four virulence genes; hence confirmed as APEC. Virulence genes, ompT and iutA were the most frequent in 33 (58.9%) and 32 (57.1%) isolates respectively; while iroN least occurred in 23 (41.1%) isolates. Seven lytic bacteriophages were isolated and their host range, at 1×108 PFU/ml, varied from 1.8% to 17.9% of the 56 APEC isolates, while the combined lytic spectrum was 25%. Phage stability was negatively affected by increasing temperatures with both UPEC04 and UPEC10 phages being undetectable at 70°C; whereas activity was detected between pH 2 and 12. The high occurrence of APEC isolates resistant against the commonly used antibiotics supports the need for alternative strategies of bacterial infections control in poultry. The low host range exhibited by the phages necessitates search for more candidates before in-depth phage characterization and application.
Optimised genetic algorithm-extreme learning machine approach for automatic COVID-19 detection
Authors: Albadr Musatafa Abbas Abbood , Tiun Sabrina , Ayob Masri , AL-Dhief Fahad Taha , Omar Khairuddin , Hamzah Faizal Amri
Published: December 2020

The coronavirus disease (COVID-19), is an ongoing global pandemic caused by severe acute respiratory syndrome. Chest Computed Tomography (CT) is an effective method for detecting lung illnesses, including COVID-19. However, the CT scan is expensive and time-consuming. Therefore, this work focus on detecting COVID-19 using chest X-ray images because it is widely available, faster, and cheaper than CT scan. Many machine learning approaches such as Deep Learning, Neural Network, and Support Vector Machine; have used X-ray for detecting the COVID-19. Although the performance of those approaches is acceptable in terms of accuracy, however, they require high computational time and more memory space. Therefore, this work employs an Optimised Genetic Algorithm-Extreme Learning Machine (OGA-ELM) with three selection criteria (i.e., random, K-tournament, and roulette wheel) to detect COVID-19 using X-ray images. The most crucial strength factors of the Extreme Learning Machine (ELM) are: (i) high capability of the ELM in avoiding overfitting; (ii) its usability on binary and multi-type classifiers; and (iii) ELM could work as a kernel-based support vector machine with a structure of a neural network. These advantages make the ELM efficient in achieving an excellent learning performance. ELMs have successfully been applied in many domains, including medical domains such as breast cancer detection, pathological brain detection, and ductal carcinoma in situ detection, but not yet tested on detecting COVID-19. Hence, this work aims to identify the effectiveness of employing OGA-ELM in detecting COVID-19 using chest X-ray images. In order to reduce the dimensionality of a histogram oriented gradient features, we use principal component analysis. The performance of OGA-ELM is evaluated on a benchmark dataset containing 188 chest X-ray images with two classes: a healthy and a COVID-19 infected. The experimental result shows that the OGA-ELM achieves 100.00% accuracy with fast computation time. This demonstrates that OGA-ELM is an efficient method for COVID-19 detecting using chest X-ray images.
Comparison of the within-reader and inter-vendor agreement of left ventricular circumferential strains and volume indices derived from cardiovascular magnetic resonance imaging
Authors: Mansell Doyin S. , Frank Evelyn G. , Kelly Nathaniel S. , Agostinho-Hernandez Bruno , Fletcher James , Bruno Vito D. , Sammut Eva , Chiribiri Amedeo , Johnson Thomas , Ascione Raimondo , Bartlett Jonathan W. , Gill Harinderjit S. , Fraser Katharine H. , Cookson Andrew N.
Published: December 2020

Purpose

Volume indices and left ventricular ejection fraction (LVEF) are routinely used to assess cardiac function. Ventricular strain values may provide additional diagnostic information, but their reproducibility is unclear. This study therefore compares the repeatability and reproducibility of volumes, volume fraction, and regional ventricular strains, derived from cardiovascular magnetic resonance (CMR) imaging, across three software packages and between readers.

Methods

Seven readers analysed 16 short-axis CMR stacks of a porcine heart. Endocardial contours were manually drawn using OsiriX and Simpleware ScanIP and repeated in both softwares. The images were also contoured automatically in Circle CVI42. Endocardial global, apical, mid-ventricular, and basal circumferential strains, as well as end-diastolic and end-systolic volume and LVEF were compared.

Results

Bland-Altman analysis found systematic biases in contour length between software packages. Compared to OsiriX, contour lengths were shorter in both ScanIP (-1.9 cm) and CVI42 (-0.6 cm), causing statistically significant differences in end-diastolic and end-systolic volumes, and apical circumferential strain (all p<0.006). No differences were found for mid-ventricular, basal or global strains, or left ventricular ejection fraction (all p<0.007). All CVI42 results lay within the ranges of the OsiriX results. Intra-software differences were found to be lower than inter-software differences.

Conclusion

OsiriX and CVI42 gave consistent results for all strain and volume metrics, with no statistical differences found between OsiriX and ScanIP for mid-ventricular, global or basal strains, or left ventricular ejection fraction. However, volumes were influenced by the choice of contouring software, suggesting care should be taken when comparing volumes across different software.
Fabrication and evaluation of complicated microstructures on cylindrical surface
Authors: Yong Jiahao , Liu Junfeng , Guan Chaoliang , Dai Yifan , Li Fei , Fan Zhanbin
Published: December 2020

Various items of roll molds are popularly used to fabricate different kinds of optical films for optoelectronic information and other new and high-tech fields, while the fabrication and evaluation of optical microstructures on a cylindrical roller surface is more difficult than ecumenically manufactured products. In this study, the machinability of microstructures on the roll based on a fast tool servo (FTS) system is investigated. First, the flexible hinge holder for a FTS is designed and its structural parameters are optimized with finite-element analysis and fatigue reliability theory. The tool radius compensation algorithm for complicated microstructures is then deduced based on the surface fitting and bilinear interpolation algorithm of discrete data. Meanwhile, the evaluation index and method are proposed by the medium section method. Finally, a machining test of aspheric arrays on a cylindrical aluminum surface is carried out, and the high quality of the microstructure indicates that the proposed method is able to be used to fabricate optical microstructures.
Effect of intentional restriction of venous return on tissue oxygenation in a porcine model of acute limb ischemia
Authors: Kim Wonho , Choi Donghoon , Jang Yangsoo , Nam Chung Mo , Hur Seung-Ho , Hong Myeong-Ki
Published: December 2020

Introduction

A sufficient oxygen supply to ischemic limb tissue is the most important requirement for wound healing and limb salvage. We investigated whether partial venous occlusion in the common iliac vein (CIV) causes a further increase of venous oxygenation in a porcine model of acute hindlimb ischemia.

Materials and methods

In 7 pigs, the model of acute hindlimb ischemia was created with intra-vascular embolization of the common iliac artery (CIA). The arterial and venous oxygen saturation was evaluated at different moments. Oxygen saturation was evaluated at baseline (T0), just after the arterial embolization (T1), at 10 minutes (T2), at 20 minutes (T3), and at 40 minutes (T4). Next, an intentional partial venous occlusion was achieved by inflating the vascular balloon at the level of the right CIV. Then, blood sampling was repeated at 5 minutes (T5), at 15 minutes (T6), and at 25 minutes (T7).

Results

The arterial oxygen saturation in the right SFA was similar during all phases. In contrast, after arterial embolization, an immediate reduction of venous oxygen saturation was observed (from 85.57 ± 1.72 at T0 to 71.86 ± 7.58 at T4). After the partial venous occlusion, interestingly, the venous oxygen saturations (T5-T7) were significantly increased, again. The venous oxygen saturations evaluated in the hindlimb ischemia with partial venous occlusion and in the control limb (without partial venous occlusion) were significantly over time. Venous oxygen saturations in the experimental limbs were higher than those in the control limbs (79.28 ± 4.82 vs 59.00 ± 2.82, p-value <0.001, 79.71 ± 4.78 vs 60.00 ± 4.24 at T7, p-value <0.001).

Conclusions

Partial venous occlusion results in an increase of venous oxygen saturation in the ischemic limb, while significant changes in venous oxygen saturation are not observed in the control limb. An explanation for this may be that the oxygen consumption in the limb tissue is increased because it gets congested with the partial venous occlusion in the right CIV.
Antifreeze protein dispersion in eelpouts and related fishes reveals migration and climate alteration within the last 20 Ma
Authors: Hobbs Rod S. , Hall Jennifer R. , Graham Laurie A. , Davies Peter L. , Fletcher Garth L.
Published: December 2020

Antifreeze proteins inhibit ice growth and are crucial for the survival of supercooled fish living in icy seawater. Of the four antifreeze protein types found in fishes, the globular type III from eelpouts is the one restricted to a single infraorder (Zoarcales), which is the only clade know to have antifreeze protein-producing species at both poles. Our analysis of over 60 unique antifreeze protein gene sequences from several Zoarcales species indicates this gene family arose around 18 Ma ago, in the Northern Hemisphere, supporting recent data suggesting that the Arctic Seas were ice-laden earlier than originally thought. The Antarctic was subject to widespread glaciation over 30 Ma and the Notothenioid fishes that produce an unrelated antifreeze glycoprotein extensively exploited the adjoining seas. We show that species from one Zoarcales family only encroached on this niche in the last few Ma, entering an environment already dominated by ice-resistant fishes, long after the onset of glaciation. As eelpouts are one of the dominant benthic fish groups of the deep ocean, they likely migrated from the north to Antarctica via the cold depths, losing all but the fully active isoform gene along the way. In contrast, northern species have retained both the fully active (QAE) and partially active (SP) isoforms for at least 15 Ma, which suggests that the combination of isoforms is functionally advantageous.
Comparative intra-articular gene transfer of seven adeno-associated virus serotypes reveals that AAV2 mediates the most efficient transduction to mouse arthritic chondrocytes
Authors: Chen Quan , Luo Huan , Zhou Chengcong , Yu Huan , Yao Sai , Fu Fangda , Seeley Rebecca , Ji Xing , Yang Yanping , Chen Peifeng , Jin Hongting , Tong Peijian , Chen Di , Wu Chengliang , Du Weibin , Ruan Hongfeng
Published: December 2020

Osteoarthritis (OA) is the most common arthropathy, characterized by progressive degeneration of the articular cartilage. Currently, there are no disease-modifying approaches for OA treatment. Adeno-associated virus (AAV)-mediated gene therapy has recently become a potential treatment for OA due to its exceptional characteristics; however, the tropism and transduction efficiency of different AAV serotypes to articular joints and the safety profile of AAV applications are still unknown. The present study aims to screen an ideal AAV serotype to efficiently transfer genes to arthritic cartilage. AAV vectors of different serotypes expressing eGFP protein were injected into the knee joint cavities of mice, with all joint tissues collected 30 days after AAV injection. The transduction efficiency of AAVs was quantified by assessing the fluorescent intensities of eGFP in the cartilage of knee joints. Structural and morphological changes were analyzed by toluidine blue staining. Changes to ECM metabolism and pyroptosis of chondrocytes were determined by immunohistochemical staining. Fluorescence analysis of eGFP showed that eGFP was expressed in the cartilage of knee joints injected with each AAV vector. Quantification of eGFP intensity indicated that AAV2, 7 and 8 had the highest transduction efficiencies. Both toluidine blue staining and Mankin score showed that AAV6 aggravated cartilage degeneration. The analysis of key molecules in ECM metabolism suggested that AAV5 and 7 significantly reduced collagen type II, while AAV9 increased ADAMTS-4 but decreased MMP-19. In addition, transduction with AAV2, 5, 7 and 8 had no obvious effect on pyroptosis of chondrocytes. Comprehensive score analysis also showed that AAV2 had the highest score in intra-articular gene transfer. Collectively, our findings point to AAV2 as the best AAV serotype candidate for gene transfer on arthritic cartilage, resulting in minimal impact to ECM metabolism and pyroptosis of chondrocytes.