Individuals who regularly shift their sleep timing, like night and/or shift‐workers suffer from circadian desynchrony and are at risk of developing cardiometabolic diseases and cancer. Also, ...shift‐work is are suggested to be a risk factor for the development of mood disorders such as the burn out syndrome, anxiety, and depression. Experimental and clinical studies provide evidence that food intake restricted to the normal activity phase is a potent synchronizer for the circadian system and can prevent the detrimental health effects associated with circadian disruption. Here, we explored whether adult male Wistar rats exposed to an experimental model of shift‐work (W‐AL) developed depressive and/or anxiety‐like behaviors and whether this was associated with neuroinflammation in brain areas involved with mood regulation. We also tested whether time‐restricted feeding (TRF) to the active phase could ameliorate circadian disruption and therefore would prevent depressive and anxiety‐like behaviors as well as neuroinflammation. In male Wistar rats, W‐AL induced depressive‐like behavior characterized by hypoactivity and anhedonia and induced increased anxiety‐like behavior in the open field test. This was associated with increased number of glial fibrillary acidic protein and IBA‐1‐positive cells in the prefrontal cortex and basolateral amygdala. Moreover W‐AL caused morphological changes in the microglia in the CA3 area of the hippocampus indicating microglial activation. Importantly, TRF prevented behavioral changes and decreased neuroinflammation markers in the brain. Present results add up evidence about the importance that TRF in synchrony with the light–dark cycle can prevent neuroinflammation leading to healthy mood states in spite of circadian disruptive conditions.
In male rats exposed to an experimental model of shift‐work, we reported circadian disruption, depressive and anxiety‐like behaviors as well as neuroinflammation in brain areas associated with mood regulation. Time‐restricted feeding associated with the normal activity phase prevents depressive and anxiety‐like behaviors as well as neuroinflammation.
Night-workers, transcontinental travelers and individuals that regularly shift their sleep timing, suffer from circadian desynchrony and are at risk to develop metabolic disease, cancer, and mood ...disorders, among others. Experimental and clinical studies provide evidence that food intake restricted to the normal activity phase is a potent synchronizer for the circadian system and can prevent the detrimental metabolic effects associated with circadian disruption. As an alternative, we hypothesized that a timed piece of chocolate scheduled to the onset of the activity phase may be sufficient stimulus to synchronize circadian rhythms under conditions of shift-work or jet-lag. In Wistar rats, a daily piece of chocolate coupled to the onset of the active phase (breakfast) accelerated re-entrainment in a jet-lag model by setting the activity of the suprachiasmatic nucleus (SCN) to the new cycle. Furthermore, in a rat model of shift-work, a piece of chocolate for breakfast prevented circadian desynchrony, by increasing the amplitude of the day-night c-Fos activation in the SCN. Contrasting, chocolate for dinner prevented re-entrainment in the jet-lag condition and favored circadian desynchrony in the shift-work models. Moreover, chocolate for breakfast resulted in low body weight gain while chocolate for dinner boosted up body weight. Present data evidence the relevance of the timing of a highly caloric and palatable meal for circadian synchrony and metabolic function.
Microglia is considered the central nervous system (CNS) resident macrophages that establish an innate immune response against pathogens and toxins. However, the recent studies have shown that ...microglial gene and protein expression follows a circadian pattern; several immune activation markers and clock genes are expressed rhythmically without the need for an immune stimulus. Furthermore, microglia responds to an immune challenge with different magnitudes depending on the time of the day. This review examines the circadian control of microglia function and the possible physiological implications. For example, we discuss that synaptic prune is performed in the cortex at a certain moment of the day. We also consider the implications of daily microglial function for maintaining biological rhythms like general activity, body temperature, and food intake. We conclude that the developmental stage, brain region, and pathological state are not the only factors to consider for the evaluation of microglial functions; instead, emerging evidence indicates that circadian time as an essential aspect for a better understanding of the role of microglia in CNS physiology.
Main Points
Microglia are rhythmic cells with an oscillatory expression in clock genes, cytokines, and other microglial markers.
Microglial circadian rhythms determine their physiological function and immune responses.
Background
There is not an ideal biomaterial for tissue‐engineered skin substitutes (TESSs), and most of the studies or existing therapies use xenogeneic origin natural biomaterials or biosynthetic ...scaffolds.
Objective
To analyse clinical, histological integration and homeostasis parameters of a human TESS manufactured with fibrin–hyaluronic acid biomaterial (HA‐Skin), grafted in immunodeficient mice for 8 weeks, and compared with the gold standard treatment (Autograft), a human TESS manufactured with fibrin–agarose biomaterial (AG‐Skin) and secondary wound healing dressings.
Methods
Human TESSs and autografts were implanted into BALB/c mice after surgical excision. Secondary wound healing approach was achieved with biosynthetic collagen wound dressing (Biobrane®) and fibrin–hyaluronic acid or fibrin–agarose biomaterial without cells (Total N = 44). Clinical integration and homeostasis parameters were evaluated every two weeks for two months. Histological and immunohistochemical analyses were performed four and eight weeks after grafting.
Results
HA‐Skin, AG‐Skin and Autograft groups showed a proper clinical integration and epithelization eight weeks later. Scar evaluation revealed better results for Autograft and HA‐Skin. Homeostasis analysis indicated similar values of transepidermal water loss and elasticity between HA‐Skin (6.42 ± 0.75 g/h/m2, 0.42 ± 0.08 AU), Autograft (6.91 ± 1.28 g/h/m2, 0.40 ± 0.08 AU) and healthy mouse skin (6.40 ± 0.43 g/h/m2, 0.35 ± 0.03 AU). Histological results showed that human TESSs and autografts presented better skin structuration and higher expression of cytokeratins.
Conclusions
This study suggests that human TESS based on fibrin–hyaluronic acid biomaterial could be suitable for clinical application in the treatment of several dermatological pathologies (wound healing).
Ni, Cu and Ni-Cu catalysts supported on high surface area graphite were synthesized by incipient wet impregnation. Also, the effect of doping the graphite support with alkali oxides (Li, Na and K) ...was studied. The catalysts were tested in the formic acid decomposition reaction to produce hydrogen. The bimetallic Ni-Cu catalyst doped with K showed the best catalytic performance with 100% conversion of formic acid at 130 °C and a 95% of selectivity to hydrogen. The turnover frequency (TOF) of the catalysts follows the order: Ni-Cu/K > NiCu/Na > Ni-Cu > Ni-Cu/Li. While the order for the apparent activation energy values is: Ni-Cu > Ni-Cu/Li > Ni-Cu/Na > Ni-Cu/K. The mechanism of the reaction is approached by programmed temperature surface reaction (TPSR) experiments and attenuated total reflectance (ATR). The greater catalytic activity of the Ni-Cu catalyst doped with potassium is ascribed to the lower stability of the formate, bicarbonate and carbonate species on its surface.
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•High purity hydrogen has been obtained through formic acid decomposition.•Non-noble Ni-Cu catalysts supported over high surface area graphite have been used.•The effect of doping the graphite support with an alkaline (Li, Na, K) was studied.•The alkalines can promote the reaction at mild temperatures.•The Ni-Cu catalyst doped with K showed the best catalytic performance.
During ontogeny, plants interact with a wide variety of microorganisms. The association with mutualistic microbes results in benefits for the plant. By contrast, pathogens may cause a remarkable ...impairment of plant growth and development. Both types of plant-microbe interactions provoke notable changes in the polyamine (PA) metabolism of the host and/or the microbe, being each interaction a complex and dynamic process. It has been well documented that the levels of free and conjugated PAs undergo profound changes in plant tissues during the interaction with microorganisms. In general, this is correlated with a precise and coordinated regulation of PA biosynthetic and catabolic enzymes. Interestingly, some evidence suggests that the relative importance of these metabolic pathways may depend on the nature of the microorganism, a concept that stems from the fact that these amines mediate the activation of plant defense mechanisms. This effect is mediated mostly through PA oxidation, even though part of the response is activated by non-oxidized PAs. In the last years, a great deal of effort has been devoted to profile plant gene expression following microorganism recognition. In addition, the phenotypes of transgenic and mutant plants in PA metabolism genes have been assessed. In this review, we integrate the current knowledge on this field and analyze the possible roles of these amines during the interaction of plants with microbes.
The whale shark is an endangered species that usually feeds in coastal areas of highly productive seas such as the Gulf of California, Mexico. This study aims to describe the effect of sea surface ...temperature, chlorophyll a, bathymetry and slope on the habitat suitability of whale sharks in three important aggregation sites of the Gulf of California. A total of 2396 records of occurrence of whale sharks were obtained from international databases and scientific literature between 1996 and 2018. These records were used for the creation of a species distribution model using MaxEnt for each of the three aggregation sites. The concentration of chlorophyll a explained 71% of the habitat suitability, followed by bathymetry and slope with a combined 17%, and sea surface temperature constituting 10% of the model. Habitat suitability was related to areas where nontargeted fisheries may impact whale sharks through bycatch, entanglement and ship strikes. The implications for the conservation of whale sharks should be considered for management decisions in terms of marine protected areas, fishing refugees or bans, and other regulations regarding fisheries activities.
A high surface area graphite and three functionalized graphene materials (one undoped and two N-doped prepared by different methods) synthesized by thermal treatment of a graphitic oxide were used to ...support copper catalysts, which were comparatively evaluated in the bioethanol dehydrogenation reaction. The characterization of the carbon supports by nitrogen physisorption isotherms, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) allowed us to stablish differences in the structure and chemical nature of the surface properties generated by the different synthesis procedures. Furthermore, reduced copper catalysts were characterized by XRD, transmission electron microscopy to determine the Cu nanoparticle sizes and their morphologies and XPS to obtain information on the Cu surface species. It was found that catalytic properties depended on the nature of each support, because it induced significant differences on metal nanoparticles, i.e. modifications of structural properties, as consequence of specific metal-graphite or metal-graphene interactions. Comparative studies with copper supported on a commercial silica gel highlighted the application of these carbon supported Cu catalysts as a promising alternative in terms of activity, selectivity and stability for the dehydrogenation of bioethanol into acetaldehyde. Also these Cu/graphite or Cu/graphene materials displayed high stability even when water is co-fed with ethanol.
Exposure to solar radiation can generate different types of damage to the skin, including skin cancer. Depending on the duration of the exposure, sun damage can present as sunburn, photoaging, and ...photoimmunosuppression, among other effects. Using natural products on the skin may aid in preventing the damage caused by exposure to solar radiation, in addition to reducing the adverse side effects of common sunscreens, such as irritation, allergies, phototoxic reactions, photosensitivity, and generation of reactive oxygen species. On the other hand, the UV light absorption capacity of natural products has been reported to be due to the presence of chromophores in their structure, which, when added to the beneficial effects they have on the skin, makes them attractive candidates for use as photoprotectors. The present work gathers updated information regarding skin damage caused by prolonged sun exposure. It also describes the photoprotective effect of several natural products, their mechanism of action, and their preventive and therapeutic potential. For this purpose, the scientific literature was searched using PubMed, Science Direct, and Google Scholar.
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