Changes in Gravitaxis and Gene-Expression in an Euglena gracilis Culture over Time.

Age-dependent changes in the transcription levels of 5-day-old Euglena gracilis cells, which showed positive gravitaxis, 6-day-old cells without gravitactic orientation, and older cells (9- and 11-day-old, which displayed a precise negative gravitaxis) were determined through microarray analysis. Hierarchical clustering of four independent cell cultures revealed pronounced similarities in transcription levels at the same culture age, which proves the reproducibility of the cultivation method. Employing the non-oriented cells from the 6-day-old culture as a reference, about 2779 transcripts were found to be differentially expressed. While positively gravitactic cells (5-day-old culture) showed only minor differences in gene expression compared to the 6-day reference, pronounced changes of mRNAs (mainly an increase) were found in older cells compared to the reference culture. Among others, genes coding for adenylyl cyclases, photosynthesis, and metabolic enzymes were identified to be differentially expressed. The investigated cells were grown in batch cultures, so variations in transcription levels most likely account for factors such as nutrient depletion in the medium and self-shading. Based on these findings, a particular transcript (e.g., transcript 19556) was downregulated using the RNA interference technique. Gravitaxis and phototaxis were impaired in the transformants, indicating the role of this transcript in signal transduction. Results of the experiment are discussed regarding the increasing importance of E. gracilis in biotechnology as a source of valuable products and the possible application of E. gracilis in life-support systems.

Impact of mucus and biofilm on antimicrobial photodynamic therapy: Evaluation using Ruthenium(II) complexes.

The biofilm lifestyle of bacterial pathogens is a hallmark of chronic lung infections such as in cystic fibrosis (CF) patients. Bacterial adaptation to the complex conditions in CF-affected lungs and repeated antibiotherapies lead to increasingly tolerant and hard-to-treat biofilms. In the context of growing antimicrobial resistance and restricted therapeutic options, antimicrobial photodynamic therapy (aPDT) shows great promise as an alternative to conventional antimicrobial modalities. Typically, aPDT consists in irradiating a non-toxic photosensitizer (PS) to generate reactive oxygen species (ROS), which kill pathogens in the surrounding environment. In a previous study, we reported that some ruthenium (II) complexes ([Ru(II)]) can mediate potent photodynamic inactivation (PDI) against planktonic cultures of Pseudomonas aeruginosa and Staphylococcus aureus clinical isolates. In the present work, [Ru(II)] were further assayed to evaluate their ability to photo-inactivate such bacteria under more complex experimental conditions better recapitulating the microenvironment in lung infected airways. Bacterial PDI was tentatively correlated with the properties of [Ru(II)] in biofilms, in mucus, and following diffusion across the latter. Altogether, the results obtained demonstrate the negative impacting role of mucus and biofilm components on [Ru(II)]-mediated PDT, following different possible mechanisms of action. Technical limitations were also identified that may be overcome, making this report a pilot for other similar studies. In conclusion, [Ru(II)] may be subjected to specific chemical engineering and/or drug formulation to adapt their properties to the harsh micro-environmental conditions of the infected respiratory tract.

Application of artificial intelligence in solar and wind energy resources: a strategy to deal with environmental pollution.

Environmental pollution has become a significant concern of nations. International organizations, local authorities, and social activists try to achieve sustainable development goals (SDGs) to protect the environment. However, this cannot be achieved without acknowledging the role of advanced technology applications. Previous studies found a significant relationship between technology and energy resources. But the need to highlight the significance of artificial intelligence (AI) in dealing with inevitable environmental issues still requires more attention. This study aims to analyze the application of AI applications in predicting, developing, and implementing wind and solar energy resources through a bibliometric analysis from 1991 to 2022. It uses bilioshiny of the "bibliometrix 3.0" package of R-programming for influential core aspects and keyword analysis and VOSviewer for co-occurrence analysis. The study provides significant implications for core authors, documents, sources, affiliations, and countries. It also provides keyword analysis and a co-occurrence network to cope with the conceptual integration of the literature. It reports three significant streams of literature in clusters: AI optimization and renewable energy resources; smart renewable energy resource challenges and opportunities; deep learning and machine learning forecasting; and energy efficiency. The findings will uncover the strategic perspective of AI technology for wind and solar energy generation projects.

Ruthenium(II) Polypyridyl Complexes for Antimicrobial Photodynamic Therapy: Prospects for Application in Cystic Fibrosis Lung Airways.

Antimicrobial photodynamic therapy (aPDT) depends on a variety of parameters notably related to the photosensitizers used, the pathogens to target and the environment to operate. In a previous study using a series of Ruthenium(II) polypyridyl ([Ru(II)]) complexes, we reported the importance of the chemical structure on both their photo-physical/physico-chemical properties and their efficacy for aPDT. By employing standard in vitro conditions, effective [Ru(II)]-mediated aPDT was demonstrated against planktonic cultures of Pseudomonas aeruginosa and Staphylococcus aureus strains notably isolated from the airways of Cystic Fibrosis (CF) patients. CF lung disease is characterized with many pathophysiological disorders that can compromise the effectiveness of antimicrobials. Taking this into account, the present study is an extension of our previous work, with the aim of further investigating [Ru(II)]-mediated aPDT under in vitro experimental settings approaching the conditions of infected airways in CF patients. Thus, we herein studied the isolated influence of a series of parameters (including increased osmotic strength, acidic pH, lower oxygen availability, artificial sputum medium and biofilm formation) on the properties of two selected [Ru(II)] complexes. Furthermore, these compounds were used to evaluate the possibility to photoinactivate P. aeruginosa while preserving an underlying epithelium of human bronchial epithelial cells. Altogether, our results provide substantial evidence for the relevance of [Ru(II)]-based aPDT in CF lung airways. Besides optimized nano-complexes, this study also highlights the various needs for translating such a challenging perspective into clinical practice.

Molecular Cross-Talk between Gravity- and Light-Sensing Mechanisms in Euglena gracilis.

Euglena gracilis is a photosynthetic flagellate. To acquire a suitable position in its surrounding aquatic environment, it exploits light and gravity primarily as environmental cues. Several physiological studies have indicated a fine-tuned relationship between gravity sensing (gravitaxis) and light sensing in E. gracilis. However, the underlying molecular mechanism is largely unknown. The photoreceptor photoactivated adenylyl cyclase (PAC) has been studied for over a decade. Nevertheless, no direct/indirect interaction partner (upstream/downstream) has been reported for PAC. It has been shown that a specific protein, kinase A (PKA), showed to be involved in phototaxis and gravitaxis. The current study reports the localization of the specific PKA and its relationship with PAC.

Impact of COVID-19 and Consortium Factors on Mental Health: Role of Emotional Labor Strategies in Achieving Sustainable Development Goals.

The COVID-19 pandemic that began in 2019 has created an acute fear of economic crisis, and people have experienced the state of perceived job insecurity. Several measures were taken to control this deadly pandemic, but it still affected the majority of global operational activities. This study addresses the United Nation's Sustainable Development Goal (SDG) number 8 that relates to decent work and economic growth. This quantitative study examines the impact of fear associated with economic crisis and perceived job insecurity on mental health with the moderating effect of surface and deep acting. Surface acting is displaying fake emotions, and deep acting is modifying inner feelings according to the required emotions. This study used sample data from private-sector employees and applied SmartPLS for structural model assessment. As many organizations took more challenging decisions to sustain their business operations, the study therefore analyzes the impact of the pandemic on private sector employees. The two main findings of the study are: (i) surface acting moderates the relationships of fear of economic crisis and perceived job insecurity with mental health and declines the impact of both on mental health, (ii) while deep acting negatively moderates the relationships of fear of economic crisis and perceived job insecurity with mental health and improved mental health even in the presence of both. The study highlighted the importance of deep acting at workplaces to sustain employees' mental and psychological stability. Organizations could introduce emotional labor strategies and strengthen the mental health of their employees against the underlying fear of economic crisis and perceived job insecurity.

Bibliometric Analysis of Post Covid-19 Management Strategies and Policies in Hospitality and Tourism.

The strategic perspective of management policies gained utmost importance during the post-Covid era. The researchers are trying to introduce strategies that can help organizations cope with post-crisis destruction. Yet, the research on the topic is fragmented, mainly related to the hospitality and tourism industry. This manuscript aims to present scholarly research findings dealing with the post-Covid-19 management strategies in the hospitality and tourism industry from January 1, 2020, to July 28, 2021. These strategies can play an essential role in the survival and growth of the sectors. The study identified and acknowledged the core contributing authors, journals, countries, affiliation, corresponding authors through bibliometric, citation, and keyword analysis. It also conducted the co-occurrence analysis and reported three significant research streams and bibliometric coupling to identify four research themes for management strategies of the tourism and hospitality industry in the post-Covid era. With the help of an influential and conceptual framework, the study highlights the future challenges managers could face and suggests the possible area for reviewing and revising the existing policies by proposing future directions. Consequently, this study contributes to the current literature on post-Covid-19 management strategies and policies by developing the critical analysis of the extant literature and highlighting the understudy areas that future studies must explore to expand the scope of the research.

A Bibliometric Analysis of Corona Pandemic in Social Sciences: A Review of Influential Aspects and Conceptual Structure.

Corona pandemic has affected the whole world, and it is a highly researched area in biological sciences. As the current pandemic has affected countries socially and economically, the purpose of this bibliometric analysis is to provide a holistic review of the corona pandemic in the field of social sciences. This study aims to highlight significant, influential aspects, research streams, and themes. We have reviewed 395 journal articles related to coronavirus in the field of social sciences from 2003 to 2020. We have deployed 'biblioshiny' a web-interface of the 'bibliometrix 3.0' package of R-studio to conduct bibliometric analysis and visualization. In the field of social sciences, we have reported influential aspects of coronavirus literature. We have found that the 'Morbidity and Mortality Weekly Report' is the top journal. The core article of coronavirus literature is 'Guidelines for preventing health-care-associated pneumonia'. The most commonly used word, in titles, abstracts, author's keywords, and keywords plus, is 'SARS'. Top affiliation is 'The University of Hong Kong'. Hong Kong is a leading country based on citations, and the USA is on top based on total publications. We have used a conceptual framework to identify potential research streams and themes in coronavirus literature. Four research streams are found by deploying a co-occurrence network. These research streams are 'Social and economic effects of epidemic disease', 'Infectious disease calamities and control', 'Outbreak of COVID 19,' and 'Infectious diseases and the role of international organizations'. Finally, a thematic map is used to provide a holistic understanding by dividing significant themes into basic or transversal, emerging or declining, motor, highly developed, but isolated themes. These themes and subthemes have proposed future directions and critical areas of research.

What an Escherichia coli Mutant Can Teach Us About the Antibacterial Effect of Chlorophyllin.

Due to the increasing development of antibiotic resistances in recent years, scientists search intensely for new methods to control bacteria. Photodynamic treatment with porphyrins such as chlorophyll derivatives is one of the most promising methods to handle bacterial infestation, but their use is dependent on illumination and they seem to be more effective against Gram-positive bacteria than against Gram-negatives. In this study, we tested chlorophyllin against three bacterial model strains, the Gram-positive Bacillus subtilis 168, the Gram-negative Escherichia coli DH5α and E. coli strain NR698 which has a deficient outer membrane, simulating a Gram-negative "without" its outer membrane. Illuminated with a standardized light intensity of 12 mW/cm², B. subtilis showed high sensitivity already at low chlorophyllin concentrations (≤105 cfu/mL: ≤0.1 mg/L, 106⁻108 cfu/mL: 0.5 mg/L), whereas E. coli DH5α was less sensitive (≤105 cfu/mL: 2.5 mg/L, 106 cfu/mL: 5 mg/L, 107⁻108 cfu/mL: ineffective at ≤25 mg/L chlorophyllin). E. coli NR698 was almost as sensitive as B. subtilis against chlorophyllin, pointing out that the outer membrane plays a significant role in protection against photodynamic chlorophyllin impacts. Interestingly, E. coli NR698 and B. subtilis can also be inactivated by chlorophyllin in darkness, indicating a second, light-independent mode of action. Thus, chlorophyllin seems to be more than a photosensitizer, and a promising substance for the control of bacteria, which deserves further investigation.

Identification of a flagellar protein implicated in the gravitaxis in the flagellate Euglena gracilis.

Flagellated cells are of great evolutionary importance across animal and plant species. Unlike higher plants, flagellated cells are involved in reproduction of macro-algae as well as in early diverging land plants. Euglena gracilis is an emerging flagellated model organism. The current study reports that a specific calmodulin (CaM2) involved in gravitaxis of E. gracilis interacts with an evolutionary conserved flagellar protein, EgPCDUF4201. The subsequent molecular analysis showed clearly that EgPCDUF4201 is also involved in gravitaxis. We performed subcellular localization of CaM2 using immunoblotting and indirect immunofluorescence. By employing yeast two-hybrid screen, EgPCDUF4201 was identified as an interaction partner of CaM2. The C-terminus of EgPCDUF4201 is responsible for the interaction with CaM2. Silencing of N- and C-terminus of EgPCDUF4201 using RNAi resulted in an impaired gravitaxis. Moreover, indirect immunofluorescence assay showed that EgPCDUF4201 is a flagella associated protein. The current study specifically addressed some important questions regarding the signal transduction chain of gravitaxis in E. gracilis. Besides the fact that it improved the current understanding of gravity sensing mechanisms in E. gracilis, it also gave rise to several interesting research questions regarding the function of the domain of unknown function 4201 in flagellated cells.

Influence of different light-dark cycles on motility and photosynthesis of Euglena gracilis in closed bioreactors.

Abstract The unicellular photosynthetic freshwater flagellate Euglena gracilis is a promising candidate as an oxygen producer in biological life-support systems. In this study, the capacity of Euglena gracilis to cope with different light regimes was determined. Cultures of Euglena gracilis in closed bioreactors were exposed to different dark-light cycles (40 W/m(2) light intensity on the surface of the 20 L reactor; cool white fluorescent lamps in combination with a 100 W filament bulb): 1 h-1 h, 2 h-2 h, 4 h-4 h, 6 h-6 h, and 8 h-16 h, respectively. Motility and oxygen development in the reactors were measured constantly. It was found that, during exposure to light-dark cycles of 1 h-1 h, 2 h-2 h, 4 h-4 h, and 6 h-6 h, precision of gravitaxis as well as the number of motile cells increased during the dark phase, while velocity increased in the light phase. Oxygen concentration did not yet reach a plateau phase. During dark-light cycles of 8 h-16 h, fast changes of movement behavior in the cells were detected. The cells showed an initial decrease of graviorientation after onset of light and an increase after the start of the dark period. In the course of the light phase, graviorientation increased, while motility and velocity decreased after some hours of illumination. In all light profiles, Euglena gracilis was able to produce sufficient oxygen in the light phase to maintain the oxygen concentration above zero in the subsequent dark phase.

Tumour necrosis factor antagonist use and associated risk reduction of cardiovascular events among patients with rheumatoid arthritis.

OBJECTIVE: To examine the association of cardiovascular events with tumour necrosis factor (TNF) α antagonist use compared with non-biological disease-modifying antirheumatic drug (DMARD) utilisation in patients with rheumatoid arthritis (RA). METHODS: The study population included 10 156 patients enrolled in the Consortium of Rheumatology Researchers of North America RA registry. Three study cohorts were defined based on three mutually exclusive drug use categories, including TNF antagonists, methotrexate and other non-biological DMARDs. HR were calculated adjusting for cardiovascular risk factors, RA disease characteristics and prednisone use. The primary study outcome was a composite of non-fatal myocardial infarction (MI), transient ischaemic attack (TIA) or stroke and cardiovascular-related death. RESULTS: There were 88 cardiovascular events, including 26 MI, 45 TIA/strokes and 17 cardiovascular-related deaths. After adjusting for age, gender, cardiovascular risk factors and RA disease characteristics, patients using a TNF antagonist experienced a reduced risk of the primary composite cardiovascular endpoint (HR 0.39, 95% CI 0.19 to 0.82) compared with users of non-biological DMARDs. Methotrexate was not associated with a reduced risk (HR 0.94, 95% CI 0.49 to 1.80). Prednisone use was associated with a dose-dependent increased risk (p=0.04). The risk reduction associated with TNF antagonists was also observed for non-fatal cardiovascular events (HR 0.35, 95% CI 0.16 to 0.74). CONCLUSION: TNF antagonist use was associated with a reduced risk of cardiovascular events in patients with RA.

Mechanisms by which sleep disturbance contributes to osteoarthritis pain: a conceptual model.

Sleep disturbance is prevalent in aging and painful rheumatologic populations, but it has largely been a neglected dimension of the routine clinical care of arthritis patients. Pain associated with osteoarthritis (OA) is a leading cause of disability worldwide, and factors that contribute to pain in OA are poorly understood. Sleep disturbance is not only a consequence of pain, it is also likely to play an integral role in pain expression. Emerging research suggests that many patients with OA demonstrate signs of generalized hyperalgesia and faulty central pain modulatory processing similar to other idiopathic pain disorders, such as fibromyalgia. Sleep disruption is increasingly recognized as a direct contributor to both hyperalgesia and impaired endogenous pain modulation. This article reviews the extant literature on sleep disturbance and hyperalgesia in patients with OA. We propose a conceptual working model describing pathways by which sleep disturbance interacts directly with central pain processing mechanisms and inflammatory processes, and indirectly with mood and physical functioning to augment clinical OA pain. The clinical and research implications of the model are discussed.

TNF antagonist safety in rheumatoid arthritis: updated evidence from observational registries.

Although the efficacy of tumor necrosis factor (TNF) antagonists for the treatment of rheumatoid arthritis (RA) has been established in randomized controlled trials (RCTs), safety concerns have emerged, particularly with regard to risk of infection, malignancy, and cardiovascular (CV) outcomes. Because of the shorter duration and limited number of patients enrolled in RCTs, evidence regarding the risk of rare adverse outcomes is frequently inconclusive. Longterm observational studies, as well as RCT meta-analyses, provide additional safety data. This review discusses the emerging evidence from observational registries on the risk of infection, malignancy, and CV outcomes associated with TNF antagonists.