Taxonomy of Geastrum species in the neotropics has been subject to divergent opinions among specialists. In our study, type collections were reassessed and compared with recent collections in order ...to delimit species in Geastrum, sect. Myceliostroma, subsect. Epigaea. A thorough review of morphologic features combined with barcode and phylogenetic analyses (ITS and LSU nrDNA) revealed six new species (G. neoamericanum, G. rubellum, G. brunneocapillatum, G. baculicrystallum, G. rubropusillum and G. courtecuissei). In additon, the presence of hairs on the exoperidium, a commonly used feature to diagnose Geastrum species, proved to be ineffective because it is a derived character within subsect. Epigaea.
β-Lactam antibiotics are one of the most relevant drug classes of antibacterial agents worldwide. The discovery and the market of first β-lactam antibiotic (Penicillin G) is a symbolic landmark of ...modern chemotherapy. Since then, several other β-lactam antibiotics have been introduced in the therapy, revolutionizing the treatment of bacterial infections. Their antibacterial efficacy has been kept in check by the emergence of bacterial resistance. Among the resistance mechanisms, the expression of β-lactamase enzymes is one of the most studied and prevalent. The combined use of beta-lactamase inhibitors with broad spectrum activity β-lactam antibiotics has been an effective strategy to circumvent the resistance issue. This review discusses, with a focus on structural aspects, the different classes of beta-lactam antibiotics (penicillins, cephalosporins, carbapenems, monobactams and penems) in light of their stability, sensitivity to β-lactamases, mechanism of action and spectrum of antimicrobial activity. β-Lactamase inhibitors (structurally correlated and non-correlated to the β-lactam system) and their proposed inhibition mechanisms are also discussed.
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•β-Lactam antibiotics: one of the most relevant antibacterial drug classes worldwide.•Structural aspects of β-lactam antibiotics and their influence on pharmacological properties.••Differences on chemical and β-lactamase stability.••Mechanism of β-lactamase inhibition.
Orthogonal Frequency Division Multiplexing (OFDM) is the modulation technology used in Fourth Generation (4G) and Fifth Generation (5G) wireless communication systems, and it will likely be essential ...to Sixth Generation (6G) wireless communication systems. However, OFDM introduces a high Peak to Average Power Ratio (PAPR) in the time domain due to constructive interference among multiple subcarriers, increasing the complexity and cost of the amplifiers and, consequently, the cost and complexity of 6G networks. Therefore, the development of new solutions to reduce the PAPR in OFDM systems is crucial to 6G networks. The application of Machine Learning (ML) has emerged as a promising avenue for tackling PAPR issues. Along this line, this paper presents a comprehensive review of PAPR optimization techniques with a focus on ML approaches. From this survey, it becomes clear that ML solutions offer customized optimization, effective search space navigation, and real-time adaptability. In light of the demands of evolving 6G networks, integration of ML is a necessity to propel advancements and meet increasing prerequisites. This integration not only presents possibilities for PAPR reduction but also calls for continued exploration to harness its potential and ensure efficient and reliable communication within 6G networks.
Despite an inherent resistance to be changed, remote fear memories can be attenuated by reconsolidation-updating approaches.Reconsolidation-updating capitalizes on an etiologically relevant period of ...memory malleability induced by recall, which is characterized by elevated levels of neuronal plasticity.Such neuronal plasticity helps fearful memories to be updated toward safety, which has been evidenced at the level of fear circuits, engrams, and molecular changes.Therefore, treatments aimed at fostering this plasticity constitute a promising approach to support reconsolidation-updating for permanently changing remote fear memories.
Traumatic events generate some of the most enduring memories, yet little is known about how long-lasting fear memories can be attenuated. In this review, we collect the surprisingly sparse evidence on remote fear memory attenuation from both animal and human research. What is becoming apparent is twofold: although remote fear memories are more resistant to change compared with recent ones, they can nevertheless be attenuated when interventions are targeted toward the period of memory malleability instigated by memory recall, the reconsolidation window. We describe the physiological mechanisms underlying remote reconsolidation-updating approaches and highlight how they can be enhanced through interventions promoting synaptic plasticity. By capitalizing on an intrinsically relevant phase of memory, reconsolidation-updating harbors the potential to permanently alter remote fear memories.
How fear is represented in the brain has generated a lot of research attention, not only because fear increases the chances for survival when appropriately expressed but also because it can lead to ...anxiety and stress-related disorders when inadequately processed. In this review, we summarize recent progress in the understanding of the neural circuits processing innate fear in rodents. We propose that these circuits are contained within three main functional units in the brain: a detection unit, responsible for gathering sensory information signaling the presence of a threat; an integration unit, responsible for incorporating the various sensory information and recruiting downstream effectors; and an output unit, in charge of initiating appropriate bodily and behavioral responses to the threatful stimulus. In parallel, the experience of innate fear also instructs a learning process leading to the memorization of the fearful event. Interestingly, while the detection, integration, and output units processing acute fear responses to different threats tend to be harbored in distinct brain circuits, memory encoding of these threats seems to rely on a shared learning system.
The Amazon Forest is a hotspot of biodiversity harboring an unknown number of undescribed taxa. Inventory studies are urgent, mainly in the areas most endangered by human activities such as extensive ...dam construction, where species could be in risk of extinction before being described and named. In 2015, intensive studies performed in a few locations in the Brazilian Amazon rainforest revealed three new species of the genus Scleroderma: S. anomalosporum, S. camassuense and S. duckei. The two first species were located in one of the many areas flooded by construction of hydroelectric dams throughout the Amazon; and the third in the Reserva Florestal Adolpho Ducke, a protected reverse by the INPA. The species were identified through morphology and molecular analyses of barcoding sequences (Internal Transcribed Spacer nrDNA). Scleroderma anomalosporum is characterized mainly by the smooth spores under LM in mature basidiomata (under SEM with small, unevenly distributed granules, a characteristic not observed in other species of the genus), the large size of the basidiomata, up to 120 mm diameter, and the stelliform dehiscence; S. camassuense mainly by the irregular to stellate dehiscence, the subreticulated spores and the bright sulfur-yellow colour, and Scleroderma duckei mainly by the verrucose exoperidium, stelliform dehiscence, and verrucose spores. Description, illustration and affinities with other species of the genus are provided.
Rationale
The experience of strong traumata leads to the formation of enduring fear memories that may degenerate into post-traumatic stress disorder. One of the most successful treatments for this ...condition consists of extinction training during which the repeated exposure to trauma-inducing stimuli in a safe environment results in an attenuation of the fearful component of trauma-related memories. While numerous studies have investigated the neural substrates of recent (e.g., 1-day-old) fear memory attenuation, much less is known about the neural networks mediating the attenuation of remote (e.g., 30-day-old) fear memories. Since extinction training becomes less effective when applied long after the original encoding of the traumatic memory, this represents an important gap in memory research.
Objectives
Here, we aimed to generate a comprehensive map of brain activation upon effective remote fear memory attenuation in the mouse.
Methods
We developed an efficient extinction training paradigm for 1-month-old contextual fear memory attenuation and performed cFos immunohistochemistry and network connectivity analyses on a set of cortical, amygdalar, thalamic, and hippocampal regions.
Results
Remote fear memory attenuation induced cFos in the prelimbic cortex, the basolateral amygdala, the nucleus reuniens of the thalamus, and the ventral fields of the hippocampal CA1 and CA3. All these structures were equally recruited by remote fear memory recall, but not by the recall of a familiar neutral context.
Conclusion
These results suggest that progressive fear attenuation mediated by repetitive exposure is accompanied by sustained neuronal activation and not reverted to a pre-conditioning brain state. These findings contribute to the identification of brain areas as targets for therapeutic approaches against traumatic memories.
► Comprehensive study of the occurrence of pharmaceuticals in the Ebro river. ► Study on distribution of pharmaceuticals between solid and liquid phase in the Ebro. ► Study of geographic distribution ...and main sources of pharmaceuticals.
The occurrence of 43 pharmaceuticals belonging to predominant therapeutic classes and their distribution in surface water, suspended solids and sediments has been investigated in the Ebro river basin in the Northeast of Spain. WWTP effluents were found to be a main source of contamination and the spatial distribution was affected by the river flow at the sampling point and corresponding dilution factor, resulting in higher concentrations and higher loads in small tributary rivers than in the Ebro river. The study showed that some compounds are preferentially found bound to suspended solids and not detected in river water. Generally, compounds with basic characteristics (pKa
>
7) showed higher tendency to bind to suspended solids. The sediment samples generally presented lower concentrations than suspended solids.
This work deals with the fabrication by robocasting of 3D porous scaffolds of an alkali-free bioactive glass composition, FastOs
®
BG, belonging to the diopside (CaMgSi
2
O
6
)–fluorapatite (Ca
5
(PO
...4
)
3
F)–tricalcium phosphate (Ca
3
(PO
4
)
2
) system. A glass frit prepared by melt quenching was grinded by dry and wet milling up to getting a suitable combination of particle sizes. The milled frit was then dispersed in aqueous media with the addition of a polycarbonate dispersant, hydroxypropyl methylcellulose (HPMC) as binder and Aristoflex
®
TAC as gelation agent. The effects of the type and amounts of the processing additives and particle size distribution on the rheological properties of the extrudable pastes were investigated. Printable inks containing 47 vol.% solids with rheological properties tuned to meet the stringent requirements of robocasting technique were obtained. Scaffolds with totally interconnected 3D pore networks and different pore sizes (200, 300 and 500 µm) could be easily fabricated and sintered. The excellent processing and sintering ability resulted in compressive strength values comparable to that of cancellous bone essential for 3D porous scaffolds intended for bone regeneration and tissue engineering applications.
In vitro follicle growth and oocyte maturation still has a series of limitations, since not all oocytes matured in vitro have the potential to develop in viable embryos. One of the factors associated ...with low oocyte quality is the generation of reactive oxygen species (ROS) during in vitro culture. Therefore, this review aims to discuss the role of non-enzymatic antioxidants in the control of oxidative stress during in vitro follicular growth, oocyte maturation and embryonic development. A wide variety of non-enzymatic antioxidants (melatonin, resveratrol, L-ascorbic acid, L-carnitine, N-acetyl-cysteine, cysteamine, quercetin, nobiletin, lycopene, acteoside, mogroside V, phycocyanin and laminarin) have been used to supplement culture media. Some of them, like N-acetyl-cysteine, cysteamine, nobiletin and quercetin act by increasing the levels of glutathione (GSH), while melatonin and resveratrol increase the expression of antioxidant enzymes and minimize oocyte oxidative stress. L-ascorbic acid reduces free radicals and reactive oxygen species. Lycopene positively regulates the expression of many antioxidant genes. Additionally, L-carnitine protects DNA against ROS-induced damage, while acteoside and laminarin reduces the expression of proapoptotic genes. Mogrosides increases mitochondrial function and reduces intracellular ROS levels, phycocyanin reduces lipid peroxidation, and lycopene neutralizes the adverse effects of ROS. Thus, it is very important to know their mechanisms of actions, because the combination of two or more antioxidants with different activities has great potential to improve in vitro culture systems.
•Non-enzymatic antioxidants reduce oxidative stress in oocytes and embryos.•Non-enzymatic antioxidants act against lipid peroxidation in oocytes and embryos.•Non-enzymatic antioxidants help to repair damaged DNA in oocytes and embryos.•Non-enzymatic antioxidants increase the expression of enzymes that control oxidative stress.
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