bluuebunny/crossref_metadata_2025 huggingface dataset:
Corporate social responsibility and frontline employees’ service improvisation: The mediating role of self-efficacy
Authors: Zhang Xuezhao , Zhang Siyuan , Wang Mingsen
Published: November 2022

The uncertainty of the COVID-19 pandemic has brought unprecedented challenges to frontline employees in tourism enterprises. In the context of the COVID-19 pandemic, the fulfillment of corporate social responsibility is of great significance. Based on the social cognitive theory, a conceptual framework was established to investigate the relationship between corporate social responsibility and tourism service improvisation, along with the mediating role of self-efficiency. A total of 405 self-administered questionnaires were collected through three times. The results revealed that frontline employees’ perception of corporate social responsibility had a significant positive impact on self-efficacy and service improvisation, as well as self-efficacy had a significant positive impact on service improvisation. Meanwhile, self-efficacy played a partial mediating role in the relationship between corporate social responsibility and service improvisation. Theoretical and practical implications, along with limitations and future research directions, were discussed.
Get vaccinated or else…employees’ perspective on mandatory vaccination in the retail sector in Zimbabwe
Authors: Mapuranga Martha , Maunganidze Farai , Ruggunan Shaun
Published: November 2022

The emergence of COVID-19 has resulted in many changes in the world of work. Measures such as remote working, physical distancing, compulsory use of face masks, sanitization among others. With time, a number of medical interventions to deal with the pandemic were developed and availed. Zimbabwe’s retail sector was not spared of different vaccines which were meant to curb the virus. Most Zimbabwean organizations made it mandatory for their employees to get vaccinated or risked losing employment. However, less is known about the perceptions of employees toward voluntary vaccination. This gap is important given the strategic nature of employees in an organization. This paper poses the following questions (1) to what extent were employees consulted on the compulsory vaccination? (2) What are the employees’ perceptions toward compulsory vaccination? (3) How are employees coping with the mandatory vaccination? The study was premised on the classical work of Kurt Lewin on types of leadership, specifically autocratic-democratic styles. Twenty shopfloor employees from two major retail outlets with functional human resource departments and works councils in Masvingo were purposively sampled and interviewed using a semi-structured interview guide. The sample composed of women and men of different age groups. Thematic analysis was used to analyze data. The paper argues that employees have a right to be involved in issues that concern them. The study has established four levels of consultation existing on a continuum namely formal and genuine consultations, formal but less genuine consultations, informal consultations, and no consultation at all. The fourth level emerged to have been the most popular among most participants. With regards to employees’ perceptions of mandatory vaccination by management, findings have revealed three categories which are, perceived good decision, perceived tight hands on the part of management and the them and us perceptions. Concerning reactions to mandatory vaccination, the study has shown that employees in the retail sector had a number of options to follow. Some went for full vaccination willingly or under duress, while others settled for a single dose. Most participants highlighted that they fraudulently obtained some vaccination cards. These findings support the relevance of engaging employees on matters that affect them. The study has therefore established the importance of genuine consultations between management and employees on issues that pertains the latter.
Complex response inhibition and cognitive flexibility in school-aged Cypriot-Greek-speaking children who stutter
Authors: Paphiti Maria , Jansson-Verkasalo Eira , Eggers Kurt
Published: November 2022

Purpose

Over the last few years, research findings have suggested limitations in executive function (EF) of children who stutter (CWS) with the evidence being more consistent in studies with preschoolers (3–6  years old) than in studies with school-aged children (6–12  years old). The purpose of the current study was to assess complex response inhibition and cognitive flexibility in school-aged CWS and their non-stuttering peers.

Methods

Participants, 19 CWS (mean age = 7.58  years, range 6.08–9.17) and 19 age-and gender-matched children who do not stutter (CWNS; mean age = 7.58  years, range 6.08–9.33), completed a visual task consisting of three task blocks. Analyses were based on response times and error percentages during the different task blocks.

Results

All participants showed expected performance-costs in task block comparisons targeting complex response inhibition and cognitive flexibility. Significant group differences were found in measures of cognitive flexibility with CWS performing slower compared to CWNS (p = 0.02). Additionally, significant block × group interactions demonstrated that CWS, compared to CWNS, slowed down more (i.e., higher performance-cost) under both complex response inhibition (p = 0.049) and cognitive flexibility task conditions (p = 0.04 for no-set-shifting and p = 0.02 for set-shifting).

Conclusion

These results are in line with some of the previous findings in school-aged CWS and suggest that CWS present lower performance in complex response inhibition and cognitive flexibility task conditions when compared to their non-stuttering peers.
Comparison of craniofacial morphology in individuals with and without hypodontia with a special focus on the number of congenitally missing teeth
Authors: Fekonja Anita , Čretnik Andrej
Published: November 2022

Background

Hypodontia might negatively affect dental function and esthetics, what might affect patients' self-esteem, communication behavior, professional performance and thus quality of life. The aim of this study was to estimate the influence of number of congenital missing teeth on dentofacial features.

Methods

Lateral cephalograms of 60 individuals with hypodontia (study group) and 40 individuals without hypodontia (control group) were analyzed. Patients in the study group were divided into two subgroups according to the number of missing teeth (group A with hypodontia 1 to 4 teeth and group B with hypodontia 5 or more teeth). Cephalometric data were compared among the study and control groups and statistically analyzed.

Results

The results in the present study revealed a significantly shorter and more retrognathic maxilla, more prognathic chin position, more retruded incisors in both jaws, large interincisal angle, straighter facial convexity as well as more retruded upper and lower lips in the group B compared with the control group. In the group A only chin position was significantly more prognathic compared with the control group.

Conclusions

According to the results of present study impact of hypodontia on the craniofacial morphology and consequently on facial esthetics was found statistically significantly greater in patients with 5 or more congenitally missing teeth.
Neighborhood social capital and self-rated mental health: Disparities between migrants and native residents in Beijing
Authors: Wang Xiaomeng , Zhou Peiling , Liu Zhilin
Published: November 2022

Introduction

Although the impact of neighborhood social capital on mental health has long been recognized, the extent to which the impact differs between immigrants and local residents remains a puzzle. This study aims to bridge the gap by comparing internal migrants who are restricted by their household registration (hukou) status, and urban natives in China.

Methods

Using self-rated mental health and social capital survey data collected in 26 neighborhoods in Beijing, this study examines the mental health outcomes of three types of neighborhood social capital, including social networks, shared norms and mutual trust, and social support.

Results

The study finds that the hukou status of immigrants moderates the effect of neighborhood social capital on mental health, and that the internal migrants in China experience less mental health benefit of neighborhood social capital than urban natives. Compared with urban natives, neighborhood social networks have less positive effect on migrants' mental health than that of urban natives.

Conclusion

The findings suggest that policy makers can improve the mental health of migrants through social capital building on the premise of eliminating the restrictions of hukou system on the migrants' right to participate in neighborhood activities and to access neighborhood services.
Differences in mortality in Switzerland by citizenship during the first and second COVID-19 waves: Analysis of death statistics
Authors: Plümecke Tino , Mikosch Heiner , Mohrenberg Steffen , Supik Linda , Bartram Isabelle , Ellebrecht Nils , zur Nieden Andrea , Schnieder Laura , Schönberger Hannah , Schulze-Marmeling Charlotte , Gutzeit Andreas
Published: November 2022

Background

Early in the COVID-19 pandemic, it became apparent that members of marginalized populations and immigrants were also at risk of being hospitalized and dying more frequently from COVID-19. To examine how the pandemic affected underserved and marginalized populations, we analyzed data on changes in the number of deaths among people with and without Swiss citizenship during the first and second SARS-CoV-2 waves.

Method

We analyzed the annual number of deaths from the Swiss Federal Statistical Office from 2015 to 2020, and weekly data from January 2020 to May 2021 on deaths of permanent residents with and without Swiss citizenship, and we differentiated the data through subdivision into age groups.

Results

People without Swiss citizenship show a higher increase in the number of deaths in 2020 than those who were Swiss citizens. The increase in deaths compared to the previous year was almost twice as high for people without Swiss citizenship (21.8%) as for those with it (11.4%). The breakdown by age group indicates that among people between the ages of 64 and 75, those without Swiss citizenship exhibited an increase in mortality (21.6%) that was four times higher than that for people with Swiss citizenship (4.7%).

Conclusion

This study confirms that a highly specialized health care system, as is found in Switzerland, does not sufficiently guarantee that all parts of the population will be equally protected in a health crisis such as COVID-19.
How a Component of Marijuana Can Be Used to Treat Epilepsy
Authors: Santos Aline de Castro , Andrade Ana Clara Matoso Montuori de , Melo Eliza Mathias , Martins Flávia Rayssa Braga , Gurgel Isabella Luisa da Silva , Zenobio Isabelle Cruz , Fontis Jordana Peruchi , de Souza Luan Tavares , Guimarães Maria Luiza Rocha , Malacco Nathalia Luisa Sousa de Oliveira , Paulino Renata Luiza Quintino , Ribeiro Thaís Salviana , Moreira Fabrício de Araújo , Soriani Frederico Marianetti
Published: November 2022

In the past, plants were the only medical resources available to people. Although plants were used a lot, sometimes they had dangerous effects. The evolution of science has allowed us to separate the helpful and dangerous compounds from various plants. An example is Cannabis sativa, also known as marijuana or weed, one of the most commonly used recreational drugs worldwide. These plants produce hundreds of compounds, called cannabinoids. The two most famous cannabinoids are tetrahydrocannabinol (THC), which produces the “high” sensation and might cause some of the negative effects of cannabis, and cannabidiol (CBD), which might be useful for treating certain diseases. In this article, we will explain how CBD can be used to treat epilepsy, a disease that affects people’s brain function. But remember: we are talking about the use of cannabinoids for therapeutic purposes only, not recreational use of marijuana.
Case report: Tunneling foreign body in the metatarsal bones of a dog
Authors: Wagoner Hannah , Holland Merrilee , Pansini Katherine , McCarthy Jess , Fiske Kaitlin
Published: November 2022

A 2-year-old male intact goldendoodle presented for intermittent lameness, persistent draining tracts, and radiographic identified boney lytic lesions involving the metatarsal region, which had persisted for approximately 8 months before presentation to our referral hospital. Radiographic and computed tomography (CT) images suggested a tubular structure encircling and tunneling through the right metatarsal bones. Exploratory surgery confirmed a circumferential rubber band foreign body, with lytic boney tunneling within the metatarsal bones. CT provided vital information to assist in the surgical planning for this patient with a chronic tunneling foreign body.
Detection and quantification of bacterial species DNA in bovine digital dermatitis lesions in swabs and fine-needle aspiration versus biopsies
Authors: Dias Angelica Petersen , De Buck Jeroen
Published: November 2022

Digital Dermatitis (DD) is a polymicrobial disease characterized by ulcerative lesions on the heel bulb of cattle and for which, despite being reported almost 50 years ago, information on the causative agent is still lacking. Tissue biopsies are regularly collected to identify bacterial presence-absence and their relative abundance in the microbiome, with sufficient evidence for the high abundance of species of Treponema spp. and other anaerobes in lesions. However, it is unclear what the potential of less-invasive sampling methods is for bacterial detection and quantification. This study aimed to test whether less-invasive sampling techniques, such as swabs and fine-needle aspiration (FNA), can be a convenient alternative to tissue biopsies in detecting and quantifying seven DD-associated bacteria in active, ulcerative DD lesions by qPCR. Twenty-two M2 DD lesions were collected using corresponding swabs, aspirates, and biopsies from dairy cows. Presence/absence and quantities of Treponema phagedenis, Treponema medium, Treponema pedis, Porphryromonas levii, Bacteroides pyogenes, Fusobacterium necrophorum, and Fusobacterium mortiferum were correlated, and Bland-Altman plot, McNemar's test, and Cohen's kappa coefficient were used to calculate the agreement among the methods. The quantities of all species were larger in swabs and smaller in aspirates compared to biopsies; however, the differences in bacterial enumeration observed between biopsies and swabs were smaller than in biopsies and aspirates. A strong correlation was observed between the quantity of T. pedis, T. medium, P. levii, and F. mortiferum in biopsies, swabs, and FNA. Yet, T. phagedenis presented the smallest difference between biopsies and swabs, followed by T. pedis and T. medium. In conclusion, swabs, aspirates, and biopsies were equal in their capacity to detect Treponema species based on the good agreement for bacteria presence/absence, with a more limited agreement for the other anaerobes, which were more often present in M2 lesions swabs by qPCR. Bacterial numbers were higher in swabs and lower in aspirates compared to biopsies, with the amounts of treponemes in swabs being closer to biopsies than in aspirates to biopsies. Therefore, aspirates were less suitable for bacterial quantification in DD lesions compared to the other methods.
The Effect of SiC-MOSFET Characteristics on the Performance of Dielectric Barrier Discharge Plasma Actuators with Two-Stroke Charge Cycle Operation
Authors: Sato Shintaro , Yoshikawa Tomoki , Ohnishi Naofumi
Published: November 2022

The low-voltage operation of a dielectric-barrier-discharge (DBD) plasma actuator with a simple electric circuit has the potential to put it into industrial applications. However, there is an issue that the efficiency of the low-voltage operated DBD plasma actuator is lower than that of the high-voltage operated one. In this study, the characteristics of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs), which are used in the electric circuit, are investigated with a focus on the on-state resistance. The on-state resistance of the SiC-MOSFET affects the rise time of the applied voltage in our experimental condition. The energy consumption by applying a pulse voltage to the DBD plasma actuator increases with increasing the on-state resistance. Flow visualization with particle image velocimetry measurement reveals that a DBD plasma actuator with the SiC-MOSFET whose on-state resistance is the lowest induces the highest velocity of the ionic wind. Also, low on-state resistance is preferable in terms of the thrust-to-power ratio. These findings contribute to the development of an optimal power supply for DBD plasma actuators for industrial applications.
A Fuzzy Backstepping Attitude Control Based on an Extended State Observer for a Tilt-Rotor UAV
Authors: Shen Suiyuan , Xu Jinfa , Xia Qingyuan
Published: November 2022

In order to overcome the influence of internal and external disturbances caused by rotor tilt motion and gust disturbance on the full flight mode control of a tilt-rotor unmanned aerial vehicle (UAV), a design method using fuzzy backstepping control based on an extended-state observer (FBS-ESO) is proposed. In this paper, fuzzy control is used to tune the parameters of the backstepping control law online, and the extended-state observer estimates the total disturbance of the controlled system to improve the controller’s robustness and anti-disturbance capability. This paper designs the attitude control system of a tilt-rotor UAV based on an FBS-ESO controller. The control performance of the FBS-ESO controller is tested in a hardware-in-loop simulation of the attitude control system. The simulation results show that changing the rotor tilt angle will destroy the stability of the traditional backstepping controller and active disturbance rejection controller (ADRC). In contrast, the FBS-ESO controller maintains good control performance. In addition, the performance of the FBS-ESO controller is not be significantly affected by adding external gust disturbance or changing the UAV parameters in the simulation. These disturbances significantly impact the traditional backstepping controller and ADRC. Therefore, the FBS-ESO controller has better anti-disturbance capabilities and robustness, as well as higher attitude control accuracy.
Identification of Optimal Starting Time Instance to Forecast Net Blotch Density in Spring Barley with Meteorological Data in Finland
Authors: Ruusunen Outi , Jalli Marja , Jauhiainen Lauri , Ruusunen Mika , Leiviskä Kauko
Published: November 2022

The performance of meteorological data-based methods to forecast plant diseases strongly depends on temporal weather information. In this paper, a data analysis procedure is presented for finding the optimal starting time for forecasting net blotch density in spring barley based on meteorological data. For this purpose, changes in the information content of typically measured weather variables were systemically quantified in sliding time windows and with additionally generated mathematical transformations, namely with features. Signal-to-noise statistics were applied in a novel way as a metric for identifying the optimal starting time instance and the most important features to successfully distinguish between two net blotch densities during springtime itself. According to the results, the information content of meteorological data used in classifying between nine years with and four years without net blotch reached its maximum in Finnish weather conditions on the 41st day from the beginning of the growing season. Specifically, utilising weather data at 41–55 days from the beginning of the growing season maximises successful forecasting potential of net blotch density. It also seems that this time instance enables a linear classification task with a selected feature subset, since the averages of the metrics in two data groups differ statistically with a minimum 68% confidence level for nine days in a 14-day time window.
Analysis and Optimization Test of the Peanut Seeding Process with an Air-Suction Roller Dibbler
Authors: Xiang Yang , Kang Jianming , Zhang Chunyan , Peng Qiangji , Zhang Ningning , Wang Xiaoyu
Published: November 2022

The air-suction roller dibbler for peanuts is the core component to realizing precision seeding on film; however, the seeds in the dibbler cannot accurately fall into the seed-guiding mechanism during the work. In this study, we stabilized the seed trajectory by adjusting the installation angles of the chock block (IACB) and installation angles of the dibbler cover (IADC). We studied the seed-movement characteristics under different IACB and dibbler covers using EDEM simulation software. The separation between the seed and the baffle was obtained for different installation conditions, which were contact separation and noncontact separation. We obtained the best seeding performance when the seed was released from the edge of the dibbler cover in contact with the baffle of the seed separation tray. In the bench test, we obtained the best seed-feeding performance at 48.28° for the IACB, 12.29° for the IADC, and 3.84 km/h for the machine. The seeding pass rate was 95.35%, the missed seeding rate was 2.52%, and the reseeding rate was 2.11%. The field verification test showed that the machine worked well with the combination, and the seeding pass rate was above 92%, which meets the requirements of the single-grain precision sowing of peanuts and substantially improves the operation performance.
The Response of Weeds and Apple Trees to Beneficial Soil Microorganisms and Mineral Fertilizers Applied in Orchards
Authors: Lisek Jerzy , Sas-Paszt Lidia , Mika Augustyn , Lisek Anna
Published: November 2022

The effect of beneficial soil fungi, bacteria and mineral fertilizers containing nitrogen, phosphorus and potassium on the level and species composition of weed infestation, uptake of macronutrients by weeds and the nutritional status of ‘Sampion’ apple trees with nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg) and calcium (Ca) was assessed in three-year studies. In the field experiment, the effect of thirteen treatments was investigated, where fungal or bacterial inocula and mineral fertilizers at a standard dose and a dose reduced by 40% were applied individually or together. The fungal inoculum contained two species: Aspergillus niger and Purpureocillium lilacinum. The bacterial consortium consisted of three Bacillus strains: Bacillus sp., Bacillus amyloliquefaciens and Paenibacillus polymyxa. The weight of weeds and the uptake of macronutrients by weeds in the apple orchard increased significantly more after the application of mineral fertilization than after the application of beneficial organisms. The increased uptake of macronutrients by weeds did not significantly change the mineral nutritional status of apple trees expressed as the content of N, P, K Mg and Ca in apple leaves. After the use of NPK mineral fertilization, also with the addition of beneficial organisms, the uptake of N by both weeds and apple trees increased. P and K were more efficiently absorbed by weeds and they achieved greater benefits from fertilization with these two macroelements than trees.
Dissecting the Genetic Mechanisms of Hemicellulose Content in Rapeseed Stalk
Authors: Xu Yinhai , Yang Yuting , Yu Wenkai , Liu Liezhao , Hu Qiong , Wei Wenliang , Liu Jia
Published: November 2022

Polysaccharides such as hemicellulose in rapeseed can be used as an abundant resource to develop biomass energy. In the present study, the hemicellulose content in the middle stalk and taproot of a rapeseed core population of 139 accessions in Guizhou, Hubei and Anhui provinces was determined. Genotyping of the core population was carried out by a 60 K single nucleotide polymorphism chip, and a genome-wide association study (GWAS) was performed to reveal the associated sites of hemicellulose content in rapeseed. The results of the GWAS showed that 28 SNPs (p ≤ 0.001) were significantly associated with hemicellulose content, and revealed that three sites—qHCs.C02 (contribution rate = 17.20%), qHCs.C05 (10.62%), and qHCs.C08 (8.80%)—are significantly associated with hemicellulose content in the stalk and three sites—qHCt.A09 (9.49%), qHCt.C05 (9.18%) and qHCt.C08 (13.10%)—are significantly associated with hemicellulose content in the taproot. Seven candidate genes associated with hemicellulose synthesis were identified in these major loci. Further RNA-seq analysis showed that two key differentially expressed genes (BnaC05G0092200ZS and BnaC05G0112400ZS) involved in hemicellulose synthesis were identified as having underlying QTL. This study excavated the key loci and candidate genes for regulating hemicellulose synthesis, providing a theoretical basis for developing rapeseed varieties with high hemicellulose content. At the same time, our results will be helpful in producing rapeseed cultivars with high lodging-resistance as well as highlighting the value of rapeseed as a resources for the bioenergy industry.
A Foundation for Archival Engineering
Authors: Thibodeau Kenneth
Published: November 2022

Archives comprise information that individuals and organizations use in their activities. Archival theory is the intellectual framework for organizing, managing, preserving and access to archives both while they serve the needs of those who produce them and later when researchers consult them for other purposes. Archival theory is sometimes called archival science, but it does not constitute a modern science in the sense of a coherent body of knowledge formulated in a way that is appropriate for empirical testing and validation. Both archival theory and practice are seriously challenged by the spread and continuing changes in information technology and its increasing and increasingly diverse use in human activities. This article describes problems with and controversies in archival theory and advocates for a reformulation of concepts to address the digital challenge and to make the field more robust, both by addressing the problems and by enriching its capabilities by adopting concepts from other fields such as taxonomy, semiotics and systemic functional linguistics. The objective of this reformulation is to transform the discipline on the model of modern scientific method in a way that engenders a new discipline of archival engineering that is robust enough to guide the development of automated methods even in the face of continuing and unpredictable change in IT.
Synthesis of Fully Deacetylated Quaternized Chitosan with Enhanced Antimicrobial Activity and Low Cytotoxicity
Authors: Kim Yeon Ho , Yoon Ki Sun , Lee Sung-Jae , Park Eun-Jung , Rhim Jong-Whan
Published: November 2022

Fully deacetylated quaternary chitosan (DQCTS) was prepared by replacing the carboxyl group of chitosan with a quaternary ammonium salt. The DQCTS was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and nuclear magnetic resonance (NMR). The antimicrobial activity of DQCTS was evaluated using the minimum inhibitory concentrations (MIC) methods and time-kill assay. DQCTS exhibited strong antibacterial and antifungal activity against Staphylococcus aureus, Escherichia coli O157: H7, Candida albicans, and Aspergillus flavus. Especially, the antifungal activity against C. albicans of DQCTS was greatly improved at 15.6 µg/mL of MIC and 31.3 µg/mL of minimum fungicidal concentration (MFC). Expression levels of virulence genes of microorganisms were also significantly decreased by DQCTS treatment, and the risk of virulence of microorganisms might be decreased. The result of the cytotoxic effect of DQCTS on human skin cells (HaCaT cells) indicated that the cytotoxicity of DQCTS on HaCaT cells was nearly non-toxic at 50 μg/mL. The DQCTS, with strong antimicrobial and low toxicity, has a high potential for use in functional food packaging and biomedical applications.
Antimicrobial Resistance Challenged with Platinum(II) and Palladium(II) Complexes Containing 1,10-Phenanthroline and 5-Amino-1,3,4-Thiadiazole-2(3H)-Thione in Campylobacter jejuni
Authors: Lacerda Meiry Leandra de , Rossi Daise Aparecida , Lourenzatto Eduarda Cristina Alves , Takeuchi Micaela Guidotti , Souza Wesley Almeida , Silva Raphael Tristão Cruvinel , Julio Luma Gonçalves , Guerra Wendell , Melo Roberta Torres de
Published: November 2022

This work describes the synthesis and characterization of two metal complexes of the type [M(L1)2(phen)], where M = Pt2+ (complex I) or Pd2+ (complex II), L1 = 5-amino-1,3,4-thiadiazole-2(3H)-thiolate and phen = 1,10-phenanthroline. The in vitro antibacterial activity of these complexes was investigated in isolation and synergistically with ciprofloxacin (CIP) and erythromycin (ERY) in three strains of Campylobacter jejuni (MIC = 32 mg/L for CIP and ERY), selected from a bank of 235 strains representative of three poultry exporting states of the country (A, B and C), previously analyzed for epidemiology and resistance to CIP and ERY. A total of 53/235 (22.55%) strains showed co-resistance to CIP and ERY. Isolated resistance to CIP was higher than to ERY. Epidemiological analysis showed that resistance to CIP was more evident in state B (p < 0.0001), as well as a higher susceptibility to ERY in state C (p = 0.0028). Co-resistance was expressive in state A and in the spring and fall seasons. The evaluation of I alone and in synergy with CIP and ERY found values up to 0.25 mg/L not significant for ERY. Complex II did not show an antimicrobial effect on the three strains of tested C. jejuni. The effect provided by complex I represents a promising alternative for control of resistant strains of C. jejuni.
Sterilization Procedures for Titanium Alloy Surfaces Leads to Higher Expression of Biofilm-Related Staphylococcus aureus Genes
Authors: Spiegel Christopher , Nogler Michael , Coraça-Huber Débora C.
Published: November 2022

Background: Around 1–2% of all implantation surgeries lead to implant-related infections, incurring costs of $40,000–$160,000 per total hip PJI. The 5-year mortality rate of prosthetic joint infections is up to 21%. To prevent infections during surgery, sterile surgery rooms and procedures have been developed and certified standards have been established. To guarantee the sterility, implants can be acquired already sterile from manufacturers. Some titanium implants can be delivered unsterilized with a manual for sterilization procedure in compliance with ISO 17664. The aim of this study is to evaluate if the most used sterilization methods (steam sterilization in an autoclave and UV light sterilization) of titanium alloys, can influence the biofilm forming capacity of Staphylococcus aureus. In this study, we examined the influence of sterilization methods on the gene expression of biofilm-associated genes and regulators. Methods: We compared gene expression of icaADBC, SarA, SigB, and SodA on titanium CP4 and Ti6Al4V alloys sterilized by UV-light and pressurized saturated steam sterilization. We performed RT-qPCR after RNA extraction of Staphylococcus aureus ATCC 29213. In addition, bacterial cell growth on the sterilized titanium surfaces was examined by colony forming unit counting on agar plates after 24 h of incubation. Results: Colony forming units of S. aureus on titanium CP4 samples showed a higher tendency in colony counts when sterilized with UV light than with pressurized saturated steam (autoclaved). Similarly, colony forming unit counts on Ti6Al4V samples showed tendencies of higher numbers on UV light sterilized samples than on autoclaved samples. Gene expression of icaADBC, SarA and SodA between steamed samples and UV light sterilized samples showed no difference on titanium CP4 samples, whereas SigB showed higher gene expression on titanium CP4 samples when sterilized with UV light than in an autoclave. On autoclaved Ti6Al4V samples, all examined genes showed 4 to 9 times higher fold changes in gene expression than on UV light sterilized samples. Conclusions: This study indicates that steam sterilization of Ti6Al4V can increase biofilm formation of S. aureus on its surface. The significantly increased gene expression of biofilm responsible genes may indicate a modification of titanium surfaces on alloy components. This may promote biofilm formation that can lead to implant-infections in vivo.
Protective Effects of Glycyrrhiza Total Flavones on Liver Injury Induced by Streptococcus agalactiae in Tilapia (Oreochromis niloticus)
Authors: Du Jinliang , Cao Liping , Gao Jiancao , Jia Rui , Zhu Haojun , Nie Zhijuan , Xi Bingwen , Yin Guojun , Ma Yuzhong , Xu Gangchun
Published: November 2022

Clinical studies have confirmed that Glycyrrhiza total flavones (GTFs) have good anti-hepatic injury, but whether they have a good protective effect on anti-hepatic injury activity induced by Streptococcus agalactiae in tilapia (Oreochromis niloticus) is unknown. The aims of this study were to investigate the protective effects of Glycyrrhiza total flavones on liver injury induced by S. agalactiae (SA) and its underlying mechanism in fish. A total of 150 tilapia were randomly divided into five groups, each with three replicates containing 10 fish: normal control group, S. agalactiae infection group, and three Glycyrrhiza total flavone treatment groups (addition of 0.1, 0.5, or 1.0 g of GTF to 1 kg of feed). The normal control group was only fed with basic diet, after 60 d of feeding, and intraperitoneal injection of the same volume of normal saline (0.05 mL/10 g body weight); the S. agalactiae infection group was fed with basic diet, and the S. agalactiae solution was intraperitoneally injected after 60 d of feeding (0.05 mL/10 g body weight); the three GTF treatment groups were fed with a diet containing 0.1, 0.5, or 1.0 g/kg of GTF, and the S. agalactiae solution was intraperitoneally injected after 60 d of feeding (0.05 mL/10 g body weight). After 48 h injection, blood and liver tissues were collected to measure biochemical parameters and mRNA levels to evaluate the liver protection of GTFs. Compared with the control group, the serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase (AKP) and glucose (GLU) in the streptococcal infection group increased significantly, while the levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) decreased significantly; observations of pathological sections showed obvious damage to the liver tissue structure in response to streptococcal infection. S. agalactiae can also cause fatty liver injury, affecting the function of fatty acid β-oxidation and biosynthesis in the liver of tilapia, and also causing damage to function of the immune system. The addition of GTFs to the diet could improve oxidative stress injury caused by S. agalactiae in tilapia liver tissue to different degrees, promote the β-oxidation of fatty acids in the liver, accelerate the lipid metabolism in the liver, and repair the damaged liver tissue. GTFs have a good protective effect on liver injury caused by streptococcus.
Successful Control of an Outbreak by Phenotypically Identified Extended-Spectrum Beta-Lactamase–Producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit
Authors: Priante Elena , Minotti Chiara , Contessa Cristina , Boschetto Margherita , Stano Paola , Dal Bello Federico , De Canale Ettore , Lolli Elisabetta , Baldo Vincenzo , Baraldi Eugenio , Donà Daniele
Published: November 2022

Background: Premature newborns represent a vulnerable population, at high risk of acquiring nosocomial infections during neonatal intensive care unit (NICU) admission. Multidrug-resistant organisms represent the greatest concern due to their intrinsic virulence and the limited therapeutic options. Resistant Enterobacterales are a growing threat for critically ill neonates, with increasing numbers of NICU outbreaks caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales being described. This study reports the early detection and successful control of an outbreak caused by ESBL-producing Klebsiella pneumoniae (ESBL-KP) in an Italian NICU in February 2021. Results: A total of 13 newborns tested positive for ESBL-KP between 2–9 February 2021, of whom four (31%) had a bloodstream infection. Two were critically ill, extremely premature newborns who died because of multiple comorbidities, and two were cured after treatment with meropenem. All other patients survived and were either discharged home or moved to other hospitals/wards in good clinical condition. ESBL-KP ST45 was found in all isolates by multilocus sequence typing (MLST) analysis. An outbreak control plan was set, including surveillance cultures for all neonates, NICU environments, and medical devices, along with the extended use of contact precautions and cohorting. In addition, the infection control plan was carried out through reinforcement and enhancement measures to guarantee maximal compliance. The outbreak was successfully controlled in seven days, given that no further cases were identified after 9 February. The source of the ESBL-KP outbreak was not identified through environmental sampling. Conclusions: Thanks to multidisciplinary management, a threatening outbreak of ESBL-KP in a NICU was controlled in few days. The prompt recognition of the event onset and the adoption of infection control interventions helped contain the bacteria spread on the ward.
Ecological Distribution of Virulent Multidrug-Resistant Staphylococcus aureus in Livestock, Environment, and Dairy Products
Authors: Badawy Basma , Elafify Mahmoud , Farag Alshimaa M. M. , Moustafa Samar M. , Sayed-Ahmed Mohamed Z. , Moawad Amira A. , Algammal Abdelazeem M. , Ramadan Hazem , Eltholth Mahmoud
Published: November 2022

Staphylococcus aureus is one of the most common causes of mastitis, leading to severe economic losses in the dairy industry. It is also zoonotic, with potential risks to public health. This study aimed to detect the occurrence of S. aureus-resistant strains isolated from cattle, buffalo, their environment, milk and dairy products; and to investigate the extent of animal, ecological, and food contamination by methicillin-resistant (MRSA) or enterotoxigenic S. aureus. Samples (n = 350) were collected from four animal (two cattle and two buffalo) farms, i.e., their environment. Thirty Karish cheese samples were collected from 10 markets in Mansoura, Egypt. S. aureus was detected in 17.9%, 17.6%, and 16.7% of samples collected from cattle, buffalo and Karish cheese, respectively. About 19% of isolated S. aureus strains carried the mecA gene. The distribution of the mecA gene was high in isolates from Karish cheese (60%), followed by samples collected from buffalo (16.2%) and cattle (16%). More than 34% of isolated S. aureus strains were enterotoxigenic, and the presence of enterotoxin genes was higher in isolates from Karish cheese (80%) than those from cattle (48%) and buffalo (18.9%). The most predominant enterotoxin gene among isolated S. aureus strains was the sea gene (26.9%), followed by sec (4.5%) and sed (3%) genes. Isolated strains were resistant to clindamycin (100%), kanamycin (97%), nalidixic acid (86.6%), cefotaxime (73.1%) sulphamethazole—trimethoprim (65.6%). Meanwhile, 95.5%, 94%, 86.6% and 77.7% of S. aureus strains were sensitive to ciprofloxacin, amikacin, imipenem and both cefoxitin and gentamycin, respectively. In conclusion, the presence of enterotoxigenic- and methicillin-resistant S. aureus strains in animals, their environment, and dairy products represents a public health concern, particularly in small-scale dairy farms in Egypt. To reduce the risk of infection of livestock and humans with resistant strains, strict regulations and guidelines for antimicrobial use in such a system are urgently required.
Synthesis, Conformational Analysis and ctDNA Binding Studies of Flavonoid Analogues Possessing the 3,5-di-tert-butyl-4-hydroxyphenyl Moiety
Authors: Tzani Andromachi , Kritsi Eftichia , Tsamantioti Lamprini , Kostopoulou Ioanna , Karadendrou Maria-Anna , Zoumpoulakis Panagiotis , Detsi Anastasia
Published: November 2022

Flavanones and their biochemical precursors, chalcones, are naturally occurring compounds and consist of privileged scaffolds used in drug discovery due to their wide range of biological activities. In this work, two novel flavanones (3 and 4), the arylidene flavanone 5, and the chalcone 6, displaying structural analogies with butylated hydroxytoluene (BHT), were synthesized via an aldol reaction. According to the antioxidant activity studies of the synthesized flavanones, the arylidene flavanone 5 was the most potent antioxidant (70.8% interaction with DPPH radical and 77.4% inhibition of lipid peroxidation). In addition, the ability of the synthesized compounds to bind with ctDNA was measured via UV-spectroscopy, revealing that chalcone 6 has the strongest interaction with DNA (Kb = 5.0 × 10−3 M−1), while molecular docking was exploited to simulate the compound-DNA complexes. In an effort to explore the conformational features of the novel synthetic flavanones (3 and 4), arylidene flavanone 5, and chalcone 6, theoretical calculations were applied and the calculation of their physicochemical properties was also performed.
High Dietary Histamine Induces Digestive Tract Oxidative Damage in Juvenile Striped Catfish (Pangasianodon hypophthalmus)
Authors: Liu Yu , Fu Xinlangji , Huang Huajing , Fan Jiongting , Zhou Hang , Deng Junming , Tan Beiping
Published: November 2022

A 56-day feeding trial investigated the effects of dietary histamine on the antioxidant capacity, gastric and intestinal barrier functions, and growth performance of striped catfish (Pangasianodon hypophthalmus). Seven isonitrogenous (34.0% crude protein) and isolipidic (10.5% crude lipid) diets were formulated with supplemental 0, 15, 30, 60, 120, 240, and 480 mg/kg of histamine, named H0, H15, H30, H60, H120, H240, and H480 group, respectively. Results showed that the weight gain rate, specific growth rate, relative intestinal length in the H240 and H480 groups, and the condition factors in the H480 group were significantly lower than those in the H0 group. Intestinal total antioxidant capacity, peroxidase, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase activities in the H480 group were significantly lower than those in the H0 group, whereas intestinal malondialdehyde content exhibited the opposite trend. Intestinal complement 3, complement 4, immunoglobulin M, and Recombinant Mucin 2 in the H480 group were significantly lower than those in the H0 group, in contrast to intestinal lipopolysaccharide content. Intestinal IL-10 gene expression in the H480 group was significantly lower than that in the H0 group, whereas the TNF-α, IL-1, IL-6, and IL-8 gene expression exhibited opposite results. Scanning and transmission electron microscopic observation of the gastrointestinal tract revealed severe damage to the gastric mucosa and intestinal epithelium in the H480 group. The abundance of Treponema in the histamine groups was significantly higher than that in the H0 group. These results indicated that high dietary histamine decreases intestinal immunity and antioxidant capacity, inducing digestive tract oxidative damage and ultimately decreasing the growth of striped catfish.
Irregular Expression of Cellular Stress Response Markers in the Placenta of Women with Chronic Venous Disease
Authors: García-Montero Cielo , Fraile-Martinez Oscar , Rodriguez-Martín Sonia , Funes Moñux Rosa M. , Saz Jose V. , Bravo Coral , De Leon-Luis Juan A. , Ruiz-Minaya María , Pekarek Leonel , Saez Miguel A. , García-Lledo Alberto , Alvarez-Mon Melchor , Bujan Julia , García-Honduvilla Natalio , Ortega Miguel A.
Published: November 2022

Pregnancy comprises a period in a woman’s life in which the circulatory system is subjected to hemodynamical and biochemical changes. During this period, while restructuring blood vessels and exchanging maternal-fetal products there is an increased risk of developing chronic venous disease (CVD), which may have an echo in life after childbirth for both mother and child. Previously, we investigated that pregnancy-associated CVD involves changes in placental architecture at angiogenesis, lymphangiogenesis and villi morphology compared with healthy controls (HC) with no history of CVD. We aimed to more deeply investigate the oxidative stress response in placenta from women with CVD versus HC through several markers (NRF2, KEAP1, CUL3, GSK-3β). An observational, analytical, and prospective cohort study was conducted on 114 women in their third trimester of pregnancy (32 weeks). A total of 62 participants were clinically diagnosed with CVD. In parallel, 52 controls with no history of CVD (HC) were studied. Gene and protein expressions of NRF2, KEAP1, CUL3, GSK-3β were analyzed by real-time polymerase chain reaction (RT-qPCR) and immunohistochemistry. Nrf2 gene and protein expression was significantly greater in placental villi of women with CVD, while Keap1, CUL-3 and GSK-3β gene and protein expressions were significantly lower. Our results defined an aberrant gene and protein expression of Nrf2 and some of their main regulators Keap1, CUL-3 and GSK-3 β in the placenta of women with CVD, which could be an indicator of an oxidative environment observed in this tissue.
Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Attenuate Mast Cell Activation
Authors: Lin Tzou-Yien , Chang Tsong-Min , Huang Huey-Chun
Published: November 2022

The therapeutic potential of extracellular vesicles isolated from stem cells have been reported in several clinical diseases. Preclinical studies have demonstrated the beneficial effects of extracellular vesicles in the treatment of heart, kidney, liver, brain, and skin injuries. To address the putative therapeutic effects and mechanisms of extracellular vesicles derived from human umbilical cord mesenchymal stem cells on allergic activation in mast cells, we isolated extracellular vesicles from human umbilical cord-derived mesenchymal stem cells (UCMSCs) by tangential-flow filtration methods. The characteristics and identification of UCMSC-derived extracellular vesicles were examined via nanoparticle tracking analysis, transmission electron microscopy and protein marker analysis. Cytokines and tryptase in the cultured supernatant of KU812 cells were analyzed using an ELISA kit. Proteins in the MAPK and STAT5 signaling pathways were detected by Western blotting. This study showed that different doses of UCMSC-derived extracellular vesicles abolish IgE-stimulated KU812 cell activation and reduce the level of NF-κB, which subsequently leads to cell degranulation and the release of IL-1β, TNF-α and IL-6. Additionally, UCMSC-derived extracellular vesicles treatment blunted the IgE-induced signaling proteins p-P38, p-JNK and p-STAT5. Our results revealed a mechanism for anti-inflammation in which extracellular vesicles can affect the activation of mast cells and thus function in allergy regulation.