Assessment of Directional-Hemispherical Reflectance of Tablets with Cefuroxime during Storage under Elevated Temperature and Ultraviolet Radiation.

Environmental conditions can lead to changes in the physical and chemical structures of drug products. In this study, the stability of cefuroxime tablets stored under adverse conditions was evaluated based on total directional-hemispherical reflectance (THR). The THR value was measured before and after the tablets' exposure to stress factors (temperature of 45 °C and UV radiation). Each measurement was performed three times within seven spectral bands at the beginning of the experiment (day 0), and then on days 1, 2, 3, 5, and 7. In addition, hyperspectral profiles (400-1030 nm) were analyzed on days 0 and 7. A significant decrease in THR values in all wavelength ranges was observed when day 7 vs. day 0 were compared, especially for spectral bands of 335-380 nm and 1700-2500 nm (Δ = 0.220, p < 0.001 and Δ = 0.171, p < 0.001, respectively). The hyperspectral analysis confirmed a decrease in the reflectance after the end of stress conditions in the visible light range (400-700 nm) compared to tablets before the experiment. This may indicate that more radiation entered the tablets. In conclusion, the THR of cefuroxime tablets decreases during the exposure to heat and UV radiation, which may result from some physicochemical changes that have occurred during storage.

Ethanol stress responses in Kluyveromyces marxianus: current knowledge and perspectives.

The rising concern with the emission of greenhouse gases has boosted new incentives for biofuels production, which are less polluting than fossil fuels. Special attention has been given to the second-generation ethanol, as it is produced from abundant feedstocks which do not compete with food production, such as lignocellulosic biomass and whey. Kluyveromyces marxianus stands out in second-generation ethanol production due to its capacity of assimilating lactose, the sugar found in whey, and tolerating high temperatures used in simultaneous saccharification processes. Nonetheless, contrary to Saccharomyces cerevisiae, K. marxianus does not tolerate high ethanol concentrations. Ethanol causes a broad range of toxic effects on yeasts, acting on cell membrane and proteins, as well as inducing the generation of reactive oxygen species (ROS). The ethanol stress responses are not fully understood, mainly in non-conventional yeasts such as K. marxianus. Indeed, many molecular responses to ethanol stress are still inferred from S. cerevisiae. As such, a better understanding of the ethanol stress responses in K. marxianus may provide the basis for improving its use in the biofuel industry. Additionally, the selection of ethanol-tolerant strains by metabolic engineering is useful to provide strains with improved capacity to withstand stressful conditions, as well as to obtain new insights about the ethanol stress responses. Key points • It is still not totally clear why K. marxianus is less tolerant to ethanol than S. cerevisiae. • Understanding the ethanol stress response in K. marxianus is pivotal for improving its application in the biofuel industry. • The Metabolic engineering is expected to improve the ethanol tolerance in K. marxianus.

Differential response to larval crowding of a long- and a short-lived medfly biotype.

Response of endophytic fruit fly species (Tephritidae) to larval crowding is a form of scramble competition that may affect important life history traits of adults, such as survival and reproduction. Recent empirical evidence demonstrates large differences in adult life history traits, especially longevity, among Mediterranean fruit fly (Ceratitis capitata; "medfly") biotypes obtained from different regions of the world. However, whether the evolution of long lifespan is associated with response to stress induced by larval crowding has not been fully elucidated. We investigated, under constant laboratory conditions, the response of a short- and a long-lived medfly biotypes to stress induced by larval crowding. Survival and development of larvae and pupae and the size of resulting pupae were recorded. The lifespan and age-specific egg production patterns of the obtained adults were recorded. Our findings reveal that increased larval density reduced immature survival (larvae and pupae) in the short-lived biotype but had rather neutral effects on the longed-lived one. Only larvae of the long-lived biotype were capable of prolonging their developmental duration under the highest crowding regime to successfully pupate and emerge as adults. Response of emerging adults to larvae crowding conditions was similar in the two medfly biotypes. Those individuals emerging from high larval density regimes had reduced longevity and fecundity. Long-lived biotype individuals, however, appeared to suffer a higher cost in longevity compared with the short-lived one. The importance of our findings to understand the evolution of long lifespan is discussed.

What may a fussy creature reveal about body/cell size integration under stressful conditions?

There is a growing amount of empirical evidence on the important role of cell size in body size adjustment in ambient or changing conditions. Though the adaptive significance of their correspondence is well understood and demonstrated, the proximate mechanisms are still in a phase of speculation. We made interesting observations on body/cell size adjustment under stressful conditions during an experiment designed for another purpose. We found that the strength of the body/cell size match is condition-dependent. Specifically, it is stronger under more stressful conditions, and it changes depending on exposure to lower temperature vs. exposure to higher temperature. The question whether these observations are of limiting or adaptive character remains open; yet, according to our results, both versions are possible but may differ in response to stress caused by too low vs. too high temperatures. Our results suggest that testing the hypotheses on body/cell size match may be a promising study system for the recent scientific dispute on the evolutionary meaning of developmental noise as opposed to phenotypic plasticity.

[Characteristics of stress resistance and adaptive potential in the training of doctors in the system of postgraduate education].

OBJECTIVE: Introduction: The article deals with the peculiarities of physicians' stress in conditions of exam stress in postgraduate education as a structural-functional, dynamic, integrative property of the person, as a result of transactional process of collision of an individual with with the individual stress factors, which includes cognitive representation, the objective characterization of the situation and requirements for the individual. The course of diagnosis and adaptive capacity is considered in terms of physical, emotional and mental capacity, ability for social adaptation, to ensure the successful fulfillment, achievement of life goals, maintain homeostasis, efficiency and health. The aim of the research is to determine the impact of the development of teaching and exam stress on the process of adaptation of doctors in postgraduate education during continuous professional development; to study measures that will prevent the development of stress. PATIENTS AND METHODS: Materials and methods: In the work is used a range of methods: content analysis, bibliosemantic, systematic approach, analysis of products of activity. RESULTS: Review: In the human body there is a mechanism that promotes adaptation to various traumatic environmental factors that can lead to changes in the functioning of the organism. This response to the body is called a general adaptive syndrome or stress response, the main issues of which were worked out by the founder of the theory of stress Hans Sielie. Significant increase in the harmful effects of various factors on the body disturbs its livelihoods and causes the stress of all adaptation systems and in the future can lead to significant damage to the body. At present, scientists are considering several types of stress: biological, psychological, professional, emotional, sports, educational, exam and others. Academic and exam stress is one of the leading places among the causes that cause psychological stress in doctors in postgraduate education. Not successful in building exam can become a psycho-traumatic factors and create a trigger mechanism for reactive depression. Training stress refers to chronic stress while examinations can be attributed to acute stress. CONCLUSION: Conclusion: Therefore, it should be noted that frequent and prolonged stresses are gradually accumulating and may cause health problems. Any stressful situation causes changes in hemodynamics. In general, according to scientists, those people who are able to cope with stress have fewer health problems than those who are too stressed out of stress. Therefore, to manage stress, you need to learn how to control yourself and your emotions and more confidently approach non-standard situations.

Identification of chemotaxis operon cheYZA and cheA gene expression under stressful conditions in Piscirickettsia salmonis.

Piscirickettsia salmonis is the etiological agent of piscirickettsiosis, which, as the main systemic disease in the Chilean salmon industry, causes significant economic losses. This bacterium can produce biofilm as a persistence and survival strategy in adverse conditions. In other bacteria, cheA is a key gene for modulating the onset of bacterial chemotaxis, as well as having a secondary role in biofilm production. Notwithstanding this association, the potential relationships between biofilm formation and genes involved in P. salmonis chemotaxis are poorly understood. This study aimed to determine P. salmonis cheA gene expression when grown in different culture media known to induce biofilm production. Piscirickettsia salmonis AUSTRAL-005 produced moderate/high biofilm levels after 144 h of incubation in the AUSTRAL-SRS and marine broths. In contrast, LF-89 biofilm production was weak/nonexistent in the aforementioned broths. Both assessed P. salmonis strains contained the cheYZA operon. Additionally, AUSTRAL-005 cheA transcripts increased in both culture media. In conclusion, these results suggest potential relationships between biofilm formation and genes related to chemotaxis in the fish pathogen P. salmonis.

New insights into survival strategies and PCB bioremediation potential of resuscitated strain Achromobacter sp. HR2 under combined stress conditions.

The resuscitated strains achieved through the addition of resuscitation promoting factor (Rpf) hold significant promise as bio-inoculants for enhancing the bioremediation of polychlorinated biphenyls (PCBs). Nevertheless, the potential of these resuscitated strains to transition into a viable but non-culturable (VBNC) state, along with the specific stressors that initiate this transformation, remains to be comprehensively elucidated. In this study, a resuscitated strain HR2, obtained through Rpf amendment, was employed to investigate its survival strategies under combined stress involving low temperature (LT), and PCBs, in the absence and presence of heavy metals (HMs). Whole-genome analysis demonstrated that HR2, affiliated with Achromobacter, possessed 107 genes associated with the degradation of polycyclic aromatic compounds. Remarkably, HR2 exhibited effective degradation of Aroclor 1242 and robust resistance to stress induced by LT and PCBs, while maintaining its culturability. However, when exposed to the combined stress of LT, PCBs, and HMs, HR2 entered the VBNC state. This state was characterized by significant decreases in enzyme activities and notable morphological, physiological, and molecular alterations compared to normal cells. These findings uncovered the survival status of resuscitated strains under stressful conditions, thereby offering valuable insights for the development of effective bioremediation strategies.

Forced Handling Decreases Emotionality but Does Not Improve Young Horses' Responses toward Humans and their Adaptability to Stress.

Horses are often still exposed to stressful or inadequate conditions and difficult relationships with humans, despite growing concerns about animal welfare. In the present study, we investigated the impact of different approaches of short-term handling sessions on young Lusitanian horses raised on a high-breed farm, specifically on their later adaptability to humans and stressful environments. Thirty-one foals (3 months old ± 15 days), from both sexes, were separated into three groups, one submitted to 3 consecutive days of handling sessions (Int-H), another to one handling session each month for 3 months (Month-H), and one left undisturbed (control). At 8 months old ± 15 days, all foals were evaluated during behavioral tests (restraint in a stock and forced-person test). Evaluations were based on behavioral observations and physiological assessments. The handled foals (Int-H and Month-H) reacted less to being isolated and restrained and better tolerated human contact and veterinary procedures than the control ones. The handled foals displayed less evasive and negative behaviors toward human approach, but also sought less human contact and did not interact, regardless of the handling timeframe. All animals displayed signs of stress when restrained in the stock, with increased neutrophil counts and CHCM levels in the blood, and no differences in metabolic (CK and LDH) and other hematological parameters. The neutrophil-lymphocyte ratio was significantly higher (p < 0.05) in handled foals than in control ones, suggesting low standards of welfare. Our data suggest that early forced handling decreases fearfulness in new environments; however, it does not improve the horses' relationship with humans, and it decreases welfare.

Regulatory Mechanisms of Plant Growth-Promoting Rhizobacteria and Plant Nutrition against Abiotic Stresses in Brassicaceae Family.

Extreme environmental conditions, such as abiotic stresses (drought, salinity, heat, chilling and intense light), offer great opportunities to study how different microorganisms and plant nutrition can influence plant growth and development. The intervention of biological agents such as plant growth-promoting rhizobacteria (PGPRs) coupled with proper plant nutrition can improve the agricultural importance of different plant species. Brassicaceae (Cruciferae) belongs to the monophyletic taxon and consists of around 338 genera and 3709 species worldwide. Brassicaceae is composed of several important species of economical, ornamental and food crops (vegetables, cooking oils, forage, condiments and industrial species). Sustainable production of Brassicas plants has been compromised over the years due to several abiotic stresses and the unbalanced utilization of chemical fertilizers and uncertified chemicals that ultimately affect the environment and human health. This chapter summarized the influence of PGPRs and nutrient management in the Brassicaceae family against abiotic stresses. The use of PGPRs contributed to combating climate-induced change/abiotic factors such as drought, soil and water salinization and heavy metal contamination that limits the general performance of plants. Brassica is widely utilized as an oil and vegetable crop and is harshly affected by abiotic stresses. Therefore, the use of PGPRs along with proper mineral nutrients management is a possible strategy to cope with abiotic stresses by improving biochemical, physiological and growth attributes and the production of brassica in an eco-friendly environment.

Current research and future directions of melatonin's role in seed germination.

Seed germination is a complex process regulated by internal and external factors. Melatonin (N-acetyl-5-methoxytryptamine) is a ubiquitous signaling molecule, playing an important role in regulating seed germination under normal and stressful conditions. In this review, we aim to provide a comprehensive overview on melatonin's effects on seed germination on the basis of existing literature. Under normal conditions, exogenous high levels of melatonin can suppress or delay seed germination, suggesting that melatonin may play a role in maintaining seed dormancy and preventing premature germination. Conversely, under stressful conditions (e.g., high salinity, drought, and extreme temperatures), melatonin has been found to accelerate seed germination. Melatonin can modulate the expression of genes involved in ABA and GA metabolism, thereby influencing the balance of these hormones and affecting the ABA/GA ratio. Melatonin has been shown to modulate ROS accumulation and nutrient mobilization, which can impact the germination process. In conclusion, melatonin can inhibit germination under normal conditions while promoting germination under stressful conditions via regulating the ABA/GA ratios, ROS levels, and metabolic enzyme activity. Further research in this area will deepen our understanding of melatonin's intricate role in seed germination and may contribute to the development of improved seed treatments and agricultural practices.

JNK in Tumor Microenvironment: Present Findings and Challenges in Clinical Translation.

The c-Jun N-terminal kinases (JNKs) are a group of mitogen-activated protein kinases (MAPKs). JNK is mainly activated under stressful conditions or by inflammatory cytokines and has multiple downstream targets for mediating cell proliferation, differentiation, survival, apoptosis, and immune responses. JNK has been demonstrated to have both tumor promoting and tumor suppressing roles in different cancers depending on the focused pathway in each study. JNK also plays complex roles in the heterogeneous tumor microenvironment (TME). JNK is involved in different tumorigenesis pathways. TME closely relates with tumor development and consists of various stressful and chronic inflammatory conditions along with different cell populations, in which the JNK pathway may have various mediating roles. In this review, we aim to summarize the present knowledge of JNK-mediated processes in TME, including hypoxia, reactive oxygen species, inflammation, immune responses, angiogenesis, as well as the regulation of various cell populations within TME. This review also suggests future research directions for translating JNK modulation in pre-clinical findings to clinical benefits.

The role of RcsA in the adaptation and survival of Escherichia coli K92.

The Rcs phosphorelay is a two-component signal transduction system that senses stressful environmental signals such as desiccation or low temperatures, which serve as natural inducers in bacteria. RcsA is an important coregulator in this system involved in some functions regulated by the Rcs system, including biofilm formation and capsule synthesis. In this sense, we previously showed that RcsA is necessary for colanic acid synthesis in Escherichia coli K92. Here, using an E. coli K92ΔrcsA mutant lacking rcsA gene we further characterize the implications of RcsA on E. coli K92 survival under osmotic and oxidative stressful conditions, and bacterial attachment and biofilm formation on both biotic and abiotic surfaces. Our results show that RcsA protects E. coli K92 against osmotic and, especially, oxidative stress at low temperatures. In addition, RcsA did not interfere in biofilm formation in any surface tested, including polystyrene, stainless steel, silicone, Teflon, aluminum and glass. By contrast, deletion of rcsA increased bacterial attachment to the caco-2 cells monolayer used as biotic surface.

Effect of stressful conditions on the carotenogenic activity of a Colombian strain of Dunaliella salina.

The objective was evaluate the carotenogenic activity of Dunaliella salina isolated from the artificial salt flats of municipality of Manaure (Department of La Guajira, Colombia). Two experimental testings were designed, in triplicate, to induce the reversibility of the cell tonality depending on the culture conditions. In the first test (A), to induce the reversibility from green to red tonality in D. salina cells, these were cultured in J/1 medium at a concentration of 4.0 M NaCl, 390 µmol m-2 s-1, 0.50 mM KNO3. In the second test (B), to induce the reversibility from red to green cell tonality, the cultures were maintained in J/1 medium 1 M NaCl, 190 µmol m-2 s-1, 5.0 mM KNO3 and pH 8.2. The population growth was evaluated by cell count and the pigment content was performed by spectrophotometric techniques. It was found that in both tests the culture conditions influenced the population growth and the pigments production of D. salina. There was a significant difference between the mean values of total carotenoids in the test A with 9.67 ±â€¯0.19 µg/ml and second test with 1.54 ±â€¯0.08 µg/ml at a significance level of p < 0.05. It was demonstrated that the culture conditions of test A induce the production of lipophilic antioxidants, among these carotenoids. The knowledge of the stressful conditions for the production of carotenoids from D. salina isolated from artificial saline of Manaure opens a field in implementation of this biotic resource for biotechnological purposes, production of new antibiotics, nutraceuticals and/or biofuels production.

Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products-A review.

Microalgae have promising potential to produce lipids and a variety of high-value chemicals. Suitable stress conditions such as nitrogen starvation and high salinity could stimulate synthesis and accumulation of lipids and high-value products by microalgae, therefore, various stress-modification strategies were developed to manipulate and optimize cultivation processes to enhance bioproduction efficiency. On the other hand, advancements in omics-based technologies have boosted the research to globally understand microalgal gene regulation under stress conditions, which enable further improvement of production efficiency via genetic engineering. Moreover, integration of multi-omics data, synthetic biology design, and genetic engineering manipulations exhibits a tremendous potential in the betterment of microalgal biorefinery. This review discusses the process manipulation strategies and omics studies on understanding the regulation of metabolite biosynthesis under various stressful conditions, and proposes genetic engineering of microalgae to improve bioproduction via manipulating stress tolerance.

The Impact of Healthcare Workers Job Environment on Their Mental-emotional Health. Coping Strategies: The Case of a Local General Hospital.

Workplace stress can influence healthcare professionals' physical and emotional well-being by curbing their efficiency and having a negative impact on their overall quality of life. The aim of the present study was to investigate the impact that work environment in a local public general hospital can have on the health workers' mental-emotional health and find strategies in order to cope with negative consequences. The study took place from July 2010 to October 2010. Our sample consisted of 200 healthcare professionals aged 21-58 years working in a 240-bed general hospital and the response rate was 91.36%). Our research protocol was first approved by the hospital's review board. A standardized questionnaire that investigates strategies for coping with stressful conditions was used. A standardized questionnaire was used in the present study Coping Strategies for Stressful Events, evaluating the strategies that persons employ in order to overcome a stressful situation or event. The questionnaire was first tested for validity and reliability which were found satisfactory (Cronbach's α=0.862). Strict anonymity of the participants was guaranteed. The SPSS 16.0 software was used for the statistical analysis. Regression analysis showed that health professionals' emotional health can be influenced by strategies for dealing with stressful events, since positive re-assessment, quitting and seeking social support are predisposing factors regarding the three first quality of life factors of the World Health Organization Quality of Life - BREF. More specifically, for the physical health factor, positive re-assessment (t=3.370, P=0.001) and quitting (t=-2.564, P=0.011) are predisposing factors. For the 'mental health and spirituality' regression model, positive re-assessment (t=5.528, P=0.000) and seeking social support (t=-1.991, P=0.048) are also predisposing factors, while regarding social relationships positive re-assessment (t=4.289, P=0.000) is a predisposing factor. According to our findings, there was a notable lack of workplace stress management strategies, which the participants usually perceive as a lack of interest on behalf of the management regarding their emotional state. Some significant factors for lowering workplace stress were found to be the need to encourage and morally reward the staff and also to provide them with opportunities for further or continuous education.

Epigenetic regulation of adaptive responses of forest tree species to the environment.

Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative capacity of plant species, and may be especially important for long-lived organisms with complex life cycles, including forest trees. Diverse environmental stresses and hybridization/polyploidization events can create reversible heritable epigenetic marks that can be transmitted to subsequent generations as a form of molecular "memory". Epigenetic changes might also contribute to the ability of plants to colonize or persist in variable environments. In this review, we provide an overview of recent data on epigenetic mechanisms involved in developmental processes and responses to environmental cues in plant, with a focus on forest tree species. We consider the possible role of forest tree epigenetics as a new source of adaptive traits in plant breeding, biotechnology, and ecosystem conservation under rapid climate change.