Improving Calculations of Electron Eye-lens Operational Dose Coefficients Using the Monte Carlo Codes PENELOPE and MCNP6.2.

ABSTRACT: After considering epidemiological studies on the induction of cataracts in individuals exposed to radiation, the International Commission on Radiological Protection recommended, in 2012, a reduction in the annual eye-dose limit of occupationally exposed workers. This imposed higher performance demands on existing dosimetry systems and the development of new dosimetry technologies. The operational quantity to be measured is Hp(3), the personal dose equivalent at a depth of 3 mm in an ICRU 4-element tissue cylinder 20 cm in height and 20 cm in diameter. The conversion coefficients per unit incident fluence, Hp(3)/Φ, were calculated using Monte Carlo simulation codes. In the case of incident electrons, the literature shows that the resulting coefficients depend on the electron transport options selected for the Monte Carlo simulations as well as the tally zone thickness. In this study, electron operational eye-lens dose coefficients were calculated using MCNP6.2 in its default settings and by invoking the single-event feature. The results were compared to those from PENELOPE, a well-known code for its enhanced accuracy in handling low-energy electron transport. The results are in agreement for the entire energy range for these two series of simulations, but differences are found with previously published dose coefficients in the literature. This impacts the calibration of dosimeters for electrons and may require a change in the commonly accepted dose coefficients.

Bioinspire-Explore: Taxonomy-Driven Exploration of Biodiversity Data for Bioinspired Innovation.

Successful bioinspired design depends on practitioners' access to biological data in a relevant form. Although multiple open-access biodiversity databases exist, their presentation is often adapted to life scientists, rather than bioinspired designers. In this paper, we present a new tool, "Bioinspire-Explore", for navigating biodiversity data in order to uncover biological systems of interest for a range of sectors. Bioinspire-Explore allows users to search for inspiring biological models via taxa (species, genera, etc.) as an entry point. It provides information on a taxon's position in the "tree of life", its distribution and climatic niche, as well as its appearance. Bioinspire-Explore also shows users connections in the bioinspiration literature between their taxon of interest and associated biological processes, habitats, and physical measurements by way of their semantic proximity. We believe Bioinspire-Explore has the potential to become an indispensable resource for both biologists and bioinspired designers in different fields.

Unveiling Insights: Harnessing the Power of the Most-Frequent-Value Method for Sensor Data Analysis.

The paper explores the application of Steiner's most-frequent-value (MFV) statistical method in sensor data analysis. The MFV is introduced as a powerful tool to identify the most-common value in a dataset, even when data points are scattered, unlike traditional mode calculations. Furthermore, the paper underscores the MFV method's versatility in estimating environmental gamma background blue (the natural level of gamma radiation present in the environment, typically originating from natural sources such as rocks, soil, and cosmic rays), making it useful in scenarios where traditional statistical methods are challenging. It presents the MFV approach as a reliable technique for characterizing ambient radiation levels around large-scale experiments, such as the DEAP-3600 dark matter detector. Using the MFV alongside passive sensors such as thermoluminescent detectors and employing a bootstrapping approach, this study showcases its effectiveness in evaluating background radiation and its aptness for estimating confidence intervals. In summary, this paper underscores the importance of the MFV and bootstrapping as valuable statistical tools in various scientific fields that involve the analysis of sensor data. These tools help in estimating the most-common values and make data analysis easier, especially in complex situations, where we need to be reasonably confident about our estimated ranges. Our calculations based on MFV statistics and bootstrapping indicate that the ambient radiation level in Cube Hall at SNOLAB is 35.19 µGy for 1342 h of exposure, with an uncertainty range of +3.41 to -3.59µGy, corresponding to a 68.27% confidence level. In the vicinity of the DEAP-3600 water shielding, the ambient radiation level is approximately 34.80 µGy, with an uncertainty range of +3.58 to -3.48µGy, also at a 68.27% confidence level. These findings offer crucial guidance for experimental design at SNOLAB, especially in the context of dark matter research.

Revisiting Nature's "Unifying Patterns": A Biological Appraisal.

Effective bioinspiration requires dialogue between designers and biologists, and this dialogue must be rooted in a shared scientific understanding of living systems. To support learning from "nature's overarching design lessons" the Biomimicry Institute has produced ten "Unifying Patterns of Nature". These patterns have been developed to engage with those interested in finding biologically inspired solutions to human challenges. Yet, although well-intentioned and appealing, they are likely to dishearten biologists. The aim of this paper is to identify why and propose alternative principles based on evolutionary theory.

New operational quantities (RBE ×Dp lens/Φ) for eye lens neutron dosimetry as a function of energy and angle of incidence in the ICRU 95 formalism.

This paper is a continuation of a study published recently by the authors. It presents and discusses computed personal absorbed dose in the lens of the eye (Dp lens/Φ), and a relative biological effectiveness (RBE)-weighted absorbed dose (in terms of an newly proposed operational quantity RBE ×Dp lens/Φ), conversion coefficients for the lens of the eye for neutron exposure at incident energies from thermal to ∼20 MeV and at angles of incidence from 0°to 90°in 15° increments, at 180° and for rotational incidence irradiation geometry (from 0°to 360°in 5°increments). These conversion coefficients were obtained from a simulation model developed for this study that contains the stylised eye model, embedded in the adult UF-ORNL mathematical phantom, whereby the previously stated RBE-weighted absorbed dose was obtained using the proposed RBE versus neutron energy distribution compiled in a previous paper by the authors. The simulations carried out for this study using the Monte Carlo N-Particle transport code version 6.2, were conducted in a realistic human eye model, for the left and right sensitive and whole volume of the lens of the eye, considering the recent proposed redefinition of the operational quantities for external radiation exposure in International Commission on Radiation Units and Measurements (ICRU) report 95. A comprehensive set of tabulated data for neutron fluence-to-dose conversion coefficients (Dp lens/Φin pGy cm2) and RBE-weighted absorbed dose (RBE ×Dp lens/Φin pGy cm2) conversion coefficients is included in this paper as a function of incident neutron energy and angle of incidence. Data forDp lens/Φ(pGy cm2) are compared to similar data from the literature for validation of our model. Data for RBE ×Dp lens/Φ(in pGy cm2), were also compared to the equivalent operational quantityHp(3,α)/Φ(in pSv cm2) conversion coefficients calculated at 3 mm depth in a cylindrical phantom for different incident neutron energies and angles of incidence from 0°to 75°in 15°increments to demonstrate the relevance of this newly proposed operational quantity for doses resulting in tissue reactions (deterministic effects) which should be quoted in Gray (RBE-weighted absorbed dose, RBE ×D(Gy)), rather than Sievert (Sv) which is reserved for stochastic effects. The current neutron weighted absorbed dose (RBE ×Dp lens) is proposed for the tissue reactions in the eye-lens for neutron radiation as per National Council on Radiation Protection and Measurements report 180 and in line with the recent proposal for the review and revision of the System of Radiological Protection to Keeping the International Commission on Radiological Protection (ICRP) recommendations fit for purpose. This method would bring better alignment between the dose limits in ICRP 118 and the new operational quantity consistent with the units of the new eye-lens dose limits without being overly conservative. The utilization of the proposed new operational quantities, as outlined in ICRU 95, has the potential to address the ongoing challenge in enforcing regulatory limits for neutron eye dose, specifically the use of Gy instead of Sv. It should be noted that the applicability of this will vary from country to country as in many countries the legislation is likely to mandate the use ofHp(3) until the regulation is amended. This approach can serve as an interim solution while awaiting the issuance of the new ICRP general recommendations, which is expected to take several years. Implementing the new operational quantities can contribute to enhancing the accuracy and effectiveness of neutron eye dose limit enforcement.

A New Software for the Calculation of Eye-lens Dosimetry Quantities Based on Dose-rate Coefficients.

ABSTRACT: In the last decade, the International Commission on Radiological Protection recommended a reduction in the annual limits to the dose to the lens of the eye from 150 mSv to 20 mSv y -1 , averaged over defined periods of 5 y, with no single year exceeding 50 mSv. To assist the health physics community in this task, many groups have calculated protection and operational fluence dose coefficients. This led to the publication of multiple coefficient tables that were calculated for arrays of different parameters, including particle type, angle of incidence, target phantom models, presence or absence of secondary charged particle equilibrium, etc. The coefficients available in the literature include protection dose values calculated in a realistic eye model and operational values calculated in a simplified cylindrical head phantom at a point 3 mm below the surface. This paper reports on a simple Windows™ application that was written to aid health physics professionals in accessing and using the large body of available protection and operational eye-lens data. The application is called the Eye-Lens Dose Calculator, as it also performs calculations of the eye-lens dose for radionuclides, where the complete emissions of the selected radionuclides are considered. Test cases show that there is good agreement between the calculated protection and operational dose quantities when radionuclide emission characteristics are considered.

A COMPUTER PROGRAM FOR THE DETERMINATION OF ABSOLUTE ACTIVITIES IN CONTAMINATIONS AND SKIN DOSES.

At radiological facilities, protocols are in place to guide radiation protection personnel in the event of the radioactive contamination of surfaces. A count rate measurement is performed with a portable contamination survey meter and a sample of the contamination is taken for later analysis and identification of the radionuclides. If the contaminated surface was of a worker's skin, then a skin dose assessment is made. The determination of the absolute activity of the radionuclides of the contamination often rests on the assumed detection efficiency of the survey meter used in the initial counting. This may lead to important underestimation or overestimation of the radionuclides' activities as the detection efficiency of the instrument must depend on the radiation type, the energy and the backscatter characteristics of the surface. This paper reports on a user-friendly computer application that relies on databases of pre-calculated detection efficiencies and skin dose rate conversion factors for the accurate assessment of contamination activities and skin doses. The results of some cases are compared with the available data in the literature.

Ambient Dose and Dose Rate Measurement in SNOLAB Underground Laboratory at Sudbury, Ontario, Canada.

The paper describes a system and experimental procedure that use integrating passive detectors, such as thermoluminescent dosimeters (TLDs), for the measurement of ultra-low-level ambient dose equivalent rate values at the underground SNOLAB facility located in Sudbury, Ontario, Canada. Because these detectors are passive and can be exposed for relatively long periods of time, they can provide better sensitivity for measuring ultra-low activity levels. The final characterization of ultra-low-level ambient dose around water shielding for ongoing direct dark matter search experiments in Cube Hall at SNOLAB underground laboratory is given. The conclusion is that TLDs provide reliable results in the measurement of the ultra-low-level environmental radiation background.

Purification and biochemical characterization of a novel ene- reductase from Kazachstania exigua HSC6 for dihydro-ß-ionone from ß-ionone.

PURPOSE: We purified and characterized a novel ene-reductase (KaDBR1) from Kazachstania exigua HSC6 for the synthesis of dihydro-ß-ionone from ß-ionone. METHODS: KaDBR1 was purified to homogeneity by ammonium sulfate precipitation and phenyl-Sepharose Fast Flow and Q-Sepharose chromatography. The purified enzyme was characterized by measuring the amount of dihydro-ß-ionone from ß-ionone with LC-MS analysis method. RESULTS: The molecular mass of KaDBR1 was estimated to be 45 kDa by SDS-PAGE. The purified KaDBR1 enzyme had optimal activity at 60 °C and pH 6.0. The addition of 5 mM Mg2+, Ca2+, Al3+, Na+, and dithiothreitol increased the activity of KaDBR1 by 25%, 18%, 34%, 20%, and 23%, respectively. KaDBR1 favored NADH over NADPH as a cofactor, and its catalytic efficiency (kcat/Km) toward ß-ionone using NADH was 8.1-fold greater than when using NADPH. CONCLUSION: Owing to its unique properties, KaDBR1 is a potential candidate for the enzymatic biotransformation of ß-ionone to dihydro-ß-ionone in biotechnology applications.

Eye-lens dose rate conversion factors due to hot particles and surface contaminations on the cornea.

In 2012, the International Commission on Radiological Protection issued new recommendations, in publication 118, regarding the dose limits to the eye-lens. New analyses of historical exposure data had indicated that radiation-induced cataracts may appear at lower doses than previously assumed. This spurred largescale efforts in a variety of fields including dosimetry, radiation effects simulations, and the review of national regulatory limits. On the simulation side, much work led to the publication of dose rate conversion factors (DRCFs), to calculate the dose to the radiosensitive part of the eye-lens, and to the whole eye-lens as functions of the incident fluence of electron, photon, positron, and neutron radiation. The standard, ISO-15382 (2015Radiological Protection-Procedures for Monitoring the Dose to the Lens of the Eye, the Skin and the Extremities), from the International Organization for Standardization (ISO), stated that the direct contact of a hot radioactive particle on the eye-lens represents a special contamination condition that must be considered. The aim of this work was to produce tabulated data of eye-lens dose rates, per activity (MBq), for a variety of radionuclides. In this work, the dose to the eye-lens from contamination directly in contact with the cornea, expressed in terms of DRCFs for eye-lens, in units of Gy h-1MBq-1, are presented for 102 radionuclides of interest. These radionuclides were selected as they had been considered by the International Atomic Energy Agency of importance for skin dose. The method consisted of two steps. The first was the determination of the DRCFs for mono-energetic electrons and photons for a hot particle in contact with the eye-lens, followed by the folding of these quantities with the emissions of the radionuclides of interest. Contributions from spontaneous fission neutrons were considered separately. Exposure geometries for spherical hot particles of different dimensions, materials and locations on the cornea were considered. In addition, partial surface coverage of the cornea, consistent with an accidental exposure to a contaminated liquid, was also modelled. Resulting radionuclide DRCFs were verified, for a few specific geometries and radionuclides with dedicated Monte Carlo simulations. The final data are presented in several tables included in this paper.

Combining bulk RNA-sequencing and single-cell RNA-sequencing data to reveal the immune microenvironment and metabolic pattern of osteosarcoma.

Background: Osteosarcoma (OS) is a kind of solid tumor with high heterogeneity at tumor microenvironment (TME), genome and transcriptome level. In view of the regulatory effect of metabolism on TME, this study was based on four metabolic models to explore the intertumoral heterogeneity of OS at the RNA sequencing (RNA-seq) level and the intratumoral heterogeneity of OS at the bulk RNA-seq and single cell RNA-seq (scRNA-seq) level. Methods: The GSVA package was used for single-sample gene set enrichment analysis (ssGSEA) analysis to obtain a glycolysis, pentose phosphate pathway (PPP), fatty acid oxidation (FAO) and glutaminolysis gene sets score. ConsensusClusterPlus was employed to cluster OS samples downloaded from the Target database. The scRNA-seq and bulk RNA-seq data of immune cells from GSE162454 dataset were analyzed to identify the subsets and types of immune cells in OS. Malignant cells and non-malignant cells were distinguished by large-scale chromosomal copy number variation. The correlations of metabolic molecular subtypes and immune cell types with four metabolic patterns, hypoxia and angiogenesis were determined by Pearson correlation analysis. Results: Two metabolism-related molecular subtypes of OS, cluster 1 and cluster 2, were identified. Cluster 2 was associated with poor prognosis of OS, active glycolysis, FAO, glutaminolysis, and bad TME. The identified 28608 immune cells were divided into 15 separate clusters covering 6 types of immune cells. The enrichment scores of 5 kinds of immune cells in cluster-1 and cluster-2 were significantly different. And five kinds of immune cells were significantly correlated with four metabolic modes, hypoxia and angiogenesis. Of the 28,608 immune cells, 7617 were malignant cells. The four metabolic patterns of malignant cells were significantly positively correlated with hypoxia and negatively correlated with angiogenesis. Conclusion: We used RNA-seq to reveal two molecular subtypes of OS with prognosis, metabolic pattern and TME, and determined the composition and metabolic heterogeneity of immune cells in OS tumor by bulk RNA-seq and single-cell RNA-seq.

Selection of the cutoff value of the tuberculin skin test for diagnosing students who need preventive treatment: A school-based cross-sectional study.

Objective: Tuberculosis outbreaks in schools are common in China. This study aimed to introduce and evaluate a new screening process to help control outbreaks. Methods: Screening information of students in three schools with tuberculosis outbreaks was collected. QuantiFERON-TB gold in-tube (QFT) results were used as the reference standard to determine the cutoff value of the tuberculin skin test (TST) for diagnosing students who need to have preventive medication. Results: A total of 1,232 students and teachers from three different schools that all had more than three student patients with tuberculosis were included in this study. In total, 308 (25.0%) students had an induration diameter ≥10 mm; among students in a class different from the index case, the infection rate was 24.4% (264/1,084), which was lower than the rate among students in the same class (29.7%) (P = 0.157). Students in the same class as the index tuberculosis case had a much higher QFT positivity compared to those in a different class (58.1% vs. 7.7%, P < 0.0001). Diagnostic agreement between TST ≥10 mm and QFT was 36.6%. The diagnostic value reached the highest when the induration diameter of TST was ≥9 mm, with a sensitivity and specificity of 94.1% (95% CI: 89.4%-97.1%) and 27.6% (95% CI: 24.9%-30.4%), respectively. The area under the curve (AUC) was 0.664 (95% CI: 0.637-0.690, P < 0.0001). Conclusion: In tuberculosis outbreaks in schools, if there are three or more cases of students with tuberculosis in a class or if the moderate or strong TST positivity rate is much higher than the normal range in the region, attention should be paid to those with moderately positive TST results. Interferon-gamma release assays (IGRAs) are recommended to be conducted following TST on the day of reading the results, especially among students sharing the same class with the index case. In resource-poor areas lacking IGRAs, the induration diameter of TST can be appropriately reduced from 15 to 9 mm to enhance the sensitivity of TST.

On the operational quantity for eye lens neutron dosimetry considering ICRU 95 report.

For planned occupational exposure situations, the International Commission on Radiological Protection (ICRP) publication 118 recommends an equivalent dose limit for the lens of the eye of 20 mSv yr-1averaged over 5 yr with no single year exceeding 50 mSv. Regulatory authorities of various jurisdictions worldwide followed some or all, of the ICRP recommendations and implemented reduced occupational lens of eye dose limits in their legislation. As compliance with the eye-lens dose limit will be based on the summation of doses received from all types of radiation, applicable to a variety of workplaces, the contribution of neutrons to eye lens dose will be important where it contributes a significant fraction of the total dose to the eye lens. This work presents and discusses computed personal absorbed dose (Dlens/Φ), and personal dose equivalent (Hp(3)/Φ) as well as a newly proposed relative biological effectiveness (RBE)-weighted absorbed dose (RBE ×Dlens/Φ) conversion coefficients for the lens of the eye for neutron exposure at incident energies from thermal to ∼20 MeV. TheDlens/Φ coefficients were obtained from a simulation model developed for this study that contains the stylised eye model embedded in the adult UF-ORNL mathematical phantom. The modelling techniques used in these simulations were also used to calculateHp(3)/Φ for the International Commission on Radiation Units and Measurements (ICRU) slab and cylinder phantoms. All simulations carried out for this study utilised the Monte Carlo N-Particle (MCNP) series of codes. The results are compared with the related published data. The issue of compliance with the current equivalent dose limit for the lens of the eye is addressed from a neutron perspective considering the recent proposed redefinition of the operational quantities for external radiation exposure in ICRU report 95. The use of a radiation weighted absorbed dose (RBE ×Dlens, in Gy) is proposed for the tissue reactions in the eye-lens for neutron radiation as per the National Council on Radiation Protection and Measurements report 180, and in line with the recent review and revision of the System of Radiological Protection To Keeping the ICRP Recommendations Fit for Purpose, which states that RBE weighted dose should be used for high-Linear energy transfer (LET) radiations such as neutrons. This confirms the earlier statement in ICRP publication 92, paragraph 297 and reiterated in the Executive summary, paragraph (q) of ICRP publication 118. The proposed approach would provide an operational quantity consistent with the units of the new eye-lens dose limits without being overly conservative.

A university-clustered tuberculosis outbreak during the COVID-19 pandemic in eastern China.

During the COVID-19 pandemic in 2020, a tuberculosis outbreak occurred in a university in eastern China, with 4,488 students and 421 staff on the campus. A 19-year-old student was diagnosed in August 2019. Later, the first round of screening was initiated among close contacts, but no active cases were found. Till September 2020, four rounds of screening were performed. Four rounds of screening were conducted on September 9, November 8, November 22-25 in 2019 and September 2020, with 0, 5, 0 and 43 cases identified, respectively. A total of 66 active tuberculosis were found in the same university, including 4 sputum culture-positive and 7 sputum smear-positive. The total attack rate of active tuberculosis was 1.34% (66/4909). The whole-genome sequencing showed that the isolates belonged to the same L2 sub-specie and were sensitive to all tested antituberculosis drugs. Delay detection, diagnosis and report of cases were the major cause of this university tuberculosis epidemic. More attention should be paid to the asymptomatic students in the index class. After the occurrence of tuberculosis cases in schools, multiple rounds of screening should be carried out, and preventive therapy should be applied in a timely manner.

Combining DNA Barcoding and Chemical fingerprints to authenticate Lavender raw material.

OBJECTIVE: This study was initiated and conducted by several laboratories, 3 of the main cosmetic ingredient suppliers and 4 brands of cosmetics in France. Its objective is to show the interest and robustness of coupling chemical and genetic analyses in the identification of plant species. In this study, the Lavandula genus was used. METHODS: In this study, we used two analytical methods. Chemical analysis from UHPLC (ultra-high-performance liquid chromatography) and genetic analysis from barcoding with genetic markers. RESULTS: Eleven lavender species were selected (botanically authenticated) and analysed. The results show that three chemical compounds (coumaric acid hexoside, ferulic acid hexoside and rosmarinic acid) and three genetic markers (RbcL, trnH-psbA and ITS) are of interest for the differentiation of species of the genus lavandula. CONCLUSION: The results show that the combination of complementary analytical methods is a relevant system to prove the botanical identification of lavender species. This first study, carried out on a plant of interest for cosmetics, demonstrates the need for authentication using a tool combining genetic and chemical analysis as an advance over traditional investigation methods used alone, in terms of identification and authentication reliability.

OBJECTIF: Cette étude a été lancée et menée par plusieurs laboratoires, trois des principaux fournisseurs d'ingrédients cosmétiques et quatre marques de cosmétiques en France. Son objectif est de montrer qu'associer les analyses chimiques et génétiques dans l'identification des espèces végétales présente un intérêt et est une approche solide. Dans cette étude, c'est le genre Lavandula qui a été utilisé. MÉTHODES: Dans cette étude, nous avons fait appel à deux méthodes analytiques. L'analyse chimique, à partir de la chromatographie en phase liquide à haute performance (ultra-high-performance liquid chromatography, UHPLC), et l'analyse génétique en procédant à un codage à barres avec des marqueurs génétiques. RÉSULTATS: Onze espèces de lavande ont été sélectionnées (authentifiées du point de vue botanique) et analysées. Les résultats montrent que trois composés chimiques (acide coumarique hexoside, acide ferulique hexoside et acide rosmarinique) et trois marqueurs génétiques (RbcL, trnH-psbA et ITS) présentent un intérêt pour la différenciation des espèces du genre lavandula. CONCLUSION: Les résultats montrent que la combinaison de méthodes analytiques complémentaires est un système pertinent pour prouver l'identification végétale des espèces de lavande. Cette première étude, réalisée sur une plante qui offre un intérêt pour les cosmétiques, démontre la nécessité de procéder à une authentification à l'aide d'un outil qui conjugue analyse génétique et chimique ; elle représente une avancée par rapport aux méthodes d'investigation traditionnelles utilisées seules, en termes d'identification et de fiabilité de l'authentification.

Current status of eye-lens dosimetry in Canada.

For occupational exposures in planned exposure situations International Commission on Radiological Protection (ICRP) publication 118 recommends an equivalent dose limit for the lens of the eye of 20 mSv yr-1averaged over five years with no single year exceeding 50 mSv. This constitutes a reduction from the previous limit of 150 mSv yr-1. The Canadian nuclear regulator, the Canadian Nuclear Safety Commission, responded to the ICRP recommendation by initiating amendments to theRadiation Protection Regulationsthrough a discussion paper which was published for comment by interested stakeholders in 2013. The revised equivalent dose limit of 50 mSv in a one-year dosimetry period for nuclear energy workers came into effect in January 2021. This paper presents the outcome of discussions with Canadian stakeholders in diverse fields of radiological work which focused on the implementation of the reduced occupational equivalent dose limit for the lens of the eye in their respective workplaces. These exchanges highlighted the existing practices for monitoring doses to the lens of the eye and identified current technological gaps. The exchanges also identified that, in many cases, the lens of the eye dose is anticipated to be well within the new dose limit despite some of the gaps in technology. The paper also presents the monitoring and eye-lens dose assessment solutions that are available based on different methods for eye-lens monitoring; presented together with criteria for their use.

A novel thermophilic ß-carotene 15,15'-monooxygenase with broad substrate specificity from the marine bacterium Candidatus Pelagibacter sp. HTCC7211.

To characterize a novel thermophilic ß-carotene 15,15'-monooxygenase BCMO7211 isolated from the marine bacterium Candidatus Pelagibacter sp. HTCC7211. BCMO7211 was functionally overexpressed in Escherichia coli and purified to homogeneity by Ni-NTA affinity chromatography and Superdex-200 gel filtration chromatography. Labeling experiments with H218O demonstrated that the oxygen atom in the terminal aldehyde group of the produced retinal molecules was provided from both molecular oxygen and water, indicating that BCMO7211 is the first characterized bacterial ß-carotene 15,15'-monooxygenase. BCMO7211 exhibited broad carotenoid substrate specificity toward α-carotene, ß-cryptoxanthin, ß-carotene, zeaxanthin, and lutein. The optimum temperature, pH, and concentrations of the substrate and enzyme for retinal production were 60 °C, 9.0, 500 mg ß-carotene/L, and 2.5 U/ml, respectively. Under optimum conditions, 888.3 mg/L retinal was produced in 60 min with a conversion rate of 89.0% (w/w). BCMO7211 is a potential candidate for the enzymatic synthesis of retinal in biotechnological applications.

The Clinical Significance of Changes in Serum New Cytokine CYTL1 in Patients with Knee Osteoarthritis.

OBJECTIVE: The present study aims to investigate the clinical significance of changes in the expression of new cytokine-like 1 (CYTL1) in the serum of patients with knee osteoarthritis (KOA). METHODS: A total of 182 patients with KOA, including 84 males and 98 females aged 39-86 with an average age of 66.4 ± 9.7 and an average body mass index (BMI) of 24.9 ± 2.4 kg/m2, were enrolled in the study. The patients were divided into three subgroups: the grade II subgroup (n = 23), grade III subgroup (n = 63), and grade IV subgroup (n = 96) based on severity, as calculated by the Kellgren and Lawrence (K&L) classification system. In addition, 152 volunteers from our health center who came in for physical examination were selected as the control group, including 70 males and 82 females aged 37-82 with an average age of 63.4 ± 9.5 and an average BMI of 24.8 ± 2.2 kg/m2. An enzyme-linked immunosorbent assay was adopted to detect the serum CYTL1 levels, and the correlation between CYTL1 and the severity of KOA was analyzed. RESULTS: The serum level of CYTL1 was significantly lower in the KOA group than in the control group (P < 0.05). In the KOA group, the difference in the serum level of CYTL1 was statistically significant between the subgroups and decreased significantly with an increase in the severity of the disease (F = 54.826, P < 0.001). Therefore, the serum level of CYTL1 was correlated with the severity of the disease, as determined by the K&L classification system (r = -0.613, P < 0.001). CONCLUSION: The serum levels of CYTL1 are strongly correlated with the severity of the disease in patients with KOA and could be a new therapeutic target for KOA.

A bagging dynamic deep learning network for diagnosing COVID-19.

COVID-19 is a serious ongoing worldwide pandemic. Using X-ray chest radiography images for automatically diagnosing COVID-19 is an effective and convenient means of providing diagnostic assistance to clinicians in practice. This paper proposes a bagging dynamic deep learning network (B-DDLN) for diagnosing COVID-19 by intelligently recognizing its symptoms in X-ray chest radiography images. After a series of preprocessing steps for images, we pre-train convolution blocks as a feature extractor. For the extracted features, a bagging dynamic learning network classifier is trained based on neural dynamic learning algorithm and bagging algorithm. B-DDLN connects the feature extractor and bagging classifier in series. Experimental results verify that the proposed B-DDLN achieves 98.8889% testing accuracy, which shows the best diagnosis performance among the existing state-of-the-art methods on the open image set. It also provides evidence for further detection and treatment.

Production, characterization, and bioactivities of exopolysaccharides from the submerged culture of Ganoderma cantharelloideum M. H. Liu.

In this study, the submerged culture conditions for exopolysaccharide (EPS) production by Ganoderma cantharelloideum M. H. Liu were screened and optimized, and the physicochemical and biological properties of EPS were investigated. Results showed that the glucose and tryptone were the best C and N sources for the maximum EPS production, respectively. Under the optimal culture conditions, the EPS production achieved 1.60 g/L at day 6 in a 5 L stirred tank reactor. Two purified fractions (i.e., Fr-I and Fr-II) were obtained from the G. cantharelloideum EPS by gel permeation chromatography. Fr-II had a higher yield (87.54%), carbohydrate (95.86%), and protein (3.07%) contents and lower molecular weight (74.56 kDa) than that of Fr-I. Both Fr-I and Fr-II were polysaccharide-protein complexes with different monosaccharide compositions and chemical structures. Fr-II also exhibited stronger radical scavenging abilities, antioxidant capacities, and α-amylase and α-glycosidase inhibitory activities in vitro than that of Fr-I. Therefore, Fr-II obtained from G. cantharelloideum EPS might be explored as potential natural functional components or supplements for applications in food, medicine, and cosmetics.