scholarly journals Endogenous Mechanisms of Neuroprotection: To Boost or Not to Be

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 370
Author(s):  
Sara Marmolejo-Martínez-Artesero ◽  
Caty Casas ◽  
David Romeo-Guitart
Keyword(s):  
Neuronal Death ◽  
Neuronal Loss ◽  
The Self ◽  
Self Healing ◽  
Compelling Evidence ◽  
Pathophysiological Mechanisms ◽  
Neuron Survival ◽  
Repair Mechanisms ◽  
Long Life ◽  
Cellular Resilience

Postmitotic cells, like neurons, must live through a lifetime. For this reason, organisms/cells have evolved with self-repair mechanisms that allow them to have a long life. The discovery workflow of neuroprotectors during the last years has focused on blocking the pathophysiological mechanisms that lead to neuronal loss in neurodegeneration. Unfortunately, only a few strategies from these studies were able to slow down or prevent neurodegeneration. There is compelling evidence demonstrating that endorsing the self-healing mechanisms that organisms/cells endogenously have, commonly referred to as cellular resilience, can arm neurons and promote their self-healing. Although enhancing these mechanisms has not yet received sufficient attention, these pathways open up new therapeutic avenues to prevent neuronal death and ameliorate neurodegeneration. Here, we highlight the main endogenous mechanisms of protection and describe their role in promoting neuron survival during neurodegeneration.

scholarly journals Pterygium—The Good, the Bad, and the Ugly

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1567
Author(s):  
Sara I. Van Acker ◽  
Bert Van den Bogerd ◽  
Michel Haagdorens ◽  
Vasiliki Siozopoulou ◽  
Sorcha Ní Dhubhghaill ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Level ◽  
The Self ◽  
Grading System ◽  
Ocular Surface Squamous Neoplasia ◽  
True Nature ◽  
Intervention Point ◽  
Pathological Evaluation ◽  
Repair Mechanisms ◽  
Life Threatening

Pterygium is a multifaceted pathology that displays apparent conflicting characteristics: benign (e.g., self-limiting and superficial), bad (e.g., proliferative and potentially recurrent) and ugly (e.g., signs of preneoplastic transformation). The natural successive question is: why are we lacking reports showing that pterygium lesions become life-threatening through metastasis, especially since pterygium has considerable similarities with UV-related malignancies on the molecular level? In this review, we consider how our pathophysiological understanding of the benign pterygium pathology overlaps with ocular surface squamous neoplasia and skin cancer. The three UV-related disorders share the same initial insult (i.e., UV radiation) and responsive repair mechanisms to the ensuing (in)direct DNA damage. Their downstream apoptotic regulators and other cellular adaptations are remarkably alike. However, a complicating factor in understanding the fine line between the self-limiting nature of pterygium and the malignant transformation in other UV-related diseases is the prominent ambiguity in the pathological evaluation of pterygium biopsies. Features of preneoplastic transformation (i.e., dysplasia) are used to define normal cellular reactions (i.e., atypia and metaplasia) and vice versa. A uniform grading system could help in unraveling the true nature of this ancient disease and potentially help in identifying the earliest intervention point possible regarding the cellular switch that drives a cell’s fate towards cancer.

scholarly journals Effect of fly ash on the self-healing capability of cementitious materials with crystalline admixture under different conditions

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075018
Author(s):  
Xi Wang ◽  
Hao Qiao ◽  
Ziwei Zhang ◽  
Shiying Tang ◽  
Shengjun Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cementitious Materials ◽  
The Self ◽  
Self Healing

scholarly journals The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials

2021 ◽  
Vol 11 (2) ◽  
pp. 700
Author(s):  
Irene A. Kanellopoulou ◽  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Hybrid Structure ◽  
The Self ◽  
Self Healing ◽  
Cementitious Composite ◽  
Superabsorbent Polymers ◽  
Porosity Reduction ◽  
Environment Control ◽  
The Impact

Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized.

ANTICORROSION PERFORMANCE OF SELF-HEALING POLYMERIC COATINGS ON LOW CARBON STEEL SUBSTRATES

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Muhammad Ashraff Ahmad Seri ◽  
Esah Hamzah ◽  
Abdelsalam Ahdash ◽  
Mohd Fauzi Mamat
Keyword(s):  
Steel Substrate ◽  
Salt Spray ◽  
Immersion Test ◽  
Salt Spray Test ◽  
Test Method ◽  
The Self ◽  
Self Healing ◽  
Pure Epoxy ◽  
Steel Substrates ◽  
Epoxy Paint

Recently, self-healing coating is classified as one of the smart coatings which has the ability to heal or repair damage of the coating to prevent further corrosion. The aim of this study is to synthesize the self-healing coatings from polymeric material and evaluate the performance and their corrosion behavior when coated on steel substrates. The corrosion tests were performed using immersion test and salt spray test method at room temperature. The immersion test shows that self-healing coating gives lower corrosion rate compared to pure epoxy paint, with a value of 0.02 and 0.05 mm/year respectively. Also, salt spray test shows similar trend as the immersion test, which is 0.11 and 0.19 mm/year for self-healing coating and pure epoxy paint respectively. While uncoated samples without any protection corroded at 0.89 mm/year. It was also found that the damage on self-healing coating was covered with zeolite from the microcapsules indicating that the self-healing agent was successfully synthesized and could function well. In other words, self-healing coating shows better corrosion resistance compared to the pure epoxy coating on steel substrate.

scholarly journals Transformation of Construction Cement to a Self-Healing Hybrid Binder

2019 ◽  
Vol 20 (12) ◽  
pp. 2948 ◽  
Author(s):  
Werner E.G. Müller ◽  
Emad Tolba ◽  
Shunfeng Wang ◽  
Qiang Li ◽  
Meik Neufurth ◽  
...  
Keyword(s):  
Soil Bacteria ◽  
Construction Material ◽  
Water Soluble ◽  
The Self ◽  
Average Chain Length ◽  
Self Healing ◽  
Cement Concrete ◽  
Low Concentrations ◽  
Natural Mechanism ◽  
Long Chain

A new biomimetic strategy to im prove the self-healing properties of Portland cement is presented that is based on the application of the biogenic inorganic polymer polyphosphate (polyP), which is used as a cement admixture. The data show that synthetic linear polyp, with an average chain length of 40, as well as natural long-chain polyP isolated from soil bacteria, has the ability to support self-healing of this construction material. Furthermore, polyP, used as a water-soluble Na-salt, is subject to Na+/Ca2+ exchange by the Ca2+ from the cement, resulting in the formation of a water-rich coacervate when added to the cement surface, especially to the surface of bacteria-containing cement/concrete samples. The addition of polyP in low concentrations (<1% on weight basis for the solids) not only accelerated the hardening of cement/concrete but also the healing of microcracks present in the material. The results suggest that long-chain polyP is a promising additive that increases the self-healing capacity of cement by mimicking a bacteria-mediated natural mechanism.

A Semi-Analytic Solution for Self-Healing Concrete Beams Through Stress Spectral Decomposition

2018 ◽  
Vol 10 (07) ◽  
pp. 1850077
Author(s):  
A. Kazemi ◽  
M. Baghani ◽  
H. Shahsavari ◽  
S. Sohrabpour
Keyword(s):  
Cross Section ◽  
Spectral Decomposition ◽  
Damage Mechanics ◽  
Concrete Beam ◽  
Rectangular Cross Section ◽  
Closed Form Solution ◽  
The Self ◽  
Continuum Damage ◽  
Self Healing ◽  
Damage Healing

Continuum damage-healing mechanics (CDHM) is used for phenomenological modeling of self-healing materials. Self-healing materials have a structural capability to recover a part of the damage for increasing materials life. In this paper, a semi-analytic modeling for self-healing concrete beam is performed. Along this purpose, an elastic damage-healing model through spectral decomposition technique is utilized to investigate an anisotropic behavior of concrete in tension and compression. We drive an analytical closed-form solution of the self-healing concrete beam. The verification of the solution is shown by solving an example for a simply supported beam having uniformly distributed the load. Finally, a result of a self-healing concrete beam is compared to elastic one to demonstrate the capability of the proposed analytical method in simulating concrete beam behavior. The results show that for the specific geometry, the self-healing concrete beam tolerates 21% more weight, and the deflection of the entire beam up to failure load is about 27% larger than elastic solution under ultimate elastic load for both I-beam and rectangular cross-section. Comparison of Continuum Damage Mechanics (CDM) solution with CDHM solution of beam shows that critical effective damage is decreased by 32.4% for a rectangular cross-section and by 24.2% for I-shape beam made of self-healing concrete.

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