Alzheimer’s disease (AD) is a neurodegenerative disease, characterized histopathologically by intra-neuronal tau-related lesions and by the accumulation of amyloid β-peptide (Aβ) in the brain parenchyma and around cerebral blood vessels. According to the vascular hypothesis of AD, an alteration in the neurovascular unit (NVU) could lead to Aβ vascular accumulation and promote neuronal dysfunction, accelerating neurodegeneration and dementia. To date, the effects of insoluble vascular Aβ deposits on the NVU and the blood–brain barrier (BBB) are unknown. In this study, we analyze different Aβ species and their association with the cells that make up the NVU. We evaluated post-mortem AD brain tissue. Multiple immunofluorescence assays were performed against different species of Aβ and the main elements that constitute the NVU. Our results showed that there are insoluble vascular deposits of both full-length and truncated Aβ species. Besides, insoluble aggregates are associated with a decrease in the phenotype of the cellular components that constitute the NVU and with BBB disruption. This approach could help identify new therapeutic targets against key molecules and receptors in the NVU that can prevent the accumulation of vascular fibrillar Aβ in AD.

A comparative study was carried out on the chemical, structural and thermal properties of candelilla wax from four wax-producing communities in Mexico, which was obtained by two extraction processes, the conventional one using sulfuric acid (SA) and an eco-friendly alternative process using citric acid (CA) as the extracting agent. The waxes were analyzed by basic chemistry (acidity, saponification, ester indexes, and others), color, Fourier transform infrared spectroscopy (FTIR), Raman micro-spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and hardness and brittleness measurements. The waxes obtained by the environmentally friendly process showed differences in their physicochemical properties when compared to waxes from the conventional process. In addition, they showed some improvements, such as lighter shades and harder waxes, suggesting that the new environmentally friendly process is a viable option.

Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m3 m−2 d−1). One series was conducted using mechanical aeration (0.62 m3 m−2 h−1). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m3 m−2 d−1, the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes.

Neurodegenerative diseases called tauopathies, such as Alzheimer’s disease (AD), frontotemporal dementia, progressive supranuclear palsy, and Parkinson’s disease, among others, are characterized by the pathological processing and accumulation of tau protein. AD is the most prevalent neurodegenerative disease and is characterized by two lesions: neurofibrillary tangles (NFTs) and neuritic plaques. The presence of NFTs in the hippocampus and neocortex in early and advanced stages, respectively, correlates with the patient’s cognitive deterioration. So far, no drugs can prevent, decrease, or limit neuronal death due to abnormal pathological tau accumulation. Among potential non-pharmacological treatments, physical exercise has been shown to stimulate the development of stem cells (SCs) and may be useful in early stages. However, this does not prevent neuronal death from the massive accumulation of NFTs. In recent years, SCs therapies have emerged as a promising tool to repopulate areas involved in cognition in neurodegenerative diseases. Unfortunately, protocols for SCs therapy are still being developed and the mechanism of action of such therapy remains unclear. In this review, we show the advances and limitations of SCs therapy. Finally, we provide a critical analysis of its clinical use for AD.