3714 research outputs found
Sort by
Pathogen infection in Alzheimer's disease: pathophysiology and therapeutic strategies
No full textAlzheimer’s disease (AD) is the most common neurodegenerative disease, which is characterized by the deposition of senile plaques composed of amyloid-β (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau. Currently, the underlying cellular and molecular mechanisms of AD are still unclear. Growing evidence suggests that pathogen infections prominently promote the development of AD pathology. In this article, we reviewed the effect of multiple infectious pathogens that contribute to AD pathogenesis. Pathogens such as bacteria, viruses, and fungi are detected in the brains of AD patients and are known to be able to promote the development of AD pathology, including Aβ deposition and the formation of tau tangles. Here, we summarized the infectious pathogen-associated mechanisms of AD and provided new insight into the anti-infection remedy for AD
Electro-assisted assembly of conductive polymer and soft hydrogel into core-shell hybrids
No full textSoft hydrogels have become an important class of materials for mimicking and interfacing biological soft tissues with potential applications in drug delivery, tissue engineering and bioelectronics. Creative methods for integrating hydrogels with other materials such as organic conductors are highly desired. Here, we describe the single-step electrosynthesis of PEDOT/alginate into core-shell hybrid structures via an electrochemical-chemical-chemical mechanism. Using a pulsed electropolymerisation protocol, we generated PEDOT in either oxidized or reduced form. By-products of this electrochemical step trigger the chemical reactions for the concomitant assembly of alginate hydrogels. Characterization evidences that PEDOT (core) and alginate (shell) compartments form an electrochemically integrated interface. During growth, both can be loaded with useful cargo. We loaded a negatively charged small molecule and investigated passive and electroactive release mechanisms from the two compartments. Our electro-assisted assembly/crosslinking of integrated PEDOT/alginate hybrids contributes a promising approach to the design of functional interfaces for applications in controlled release and soft electronics
A re-examination of the space debris problem using systems thinking
No full textArtificial satellites have enormous advantages, resulting in a massive increase in launches. As of January 2022, approximately 4852 operational satellites were orbiting Earth, assisting humans in communication, technology development, space observation, and earth science. Among the cataloged objects in space, only 20% are operational satellites, with the rest being debris. This debris poses a danger to active satellites and limits the orbital space for new satellite launches. These non-functional, fast-moving debris pieces may trigger collisions and potentially create new fragments of space junk. Most countries striving to exploit outer space have neglected the long-term consequences as explained by the tragedy of the Commons archetype. This study examines how the space race led to the specific issue of orbital debris using a systems thinking approach. Using counter-intuitiveness, causal loop diagrams (CLD), systemigrams, and archetypes as systems thinking methods and concepts to explain the space debris challenge. The systems thinking tools used in this study attempt to highlight the current space debris problem and the lack of a clear policy framework to mitigate the severity of the problem. Even though many private organizations and some space agencies are conceptualizing ideas to remove debris from space, the major issues in resolving this problem are time, cost, and uncertainty. Our findings highlight the importance of addressing the issue at the technological, system engineering, and policy levels
Mechanisms involved in cancer stem cell resistance in head and neck squamous cell carcinoma
No full textDespite scientific advances in the Oncology field, cancer remains a leading cause of death worldwide. Molecular and cellular heterogeneity of head and neck squamous cell carcinoma (HNSCC) is a significant contributor to the unpredictability of the clinical response and failure in cancer treatment. Cancer stem cells (CSCs) are recognized as a subpopulation of tumor cells that can drive and maintain tumorigenesis and metastasis, leading to poor prognosis in different types of cancer. CSCs exhibit a high level of plasticity, quickly adapting to the tumor microenvironment changes, and are intrinsically resistant to current chemo and radiotherapies. The mechanisms of CSC-mediated therapy resistance are not fully understood. However, they include different strategies used by CSCs to overcome challenges imposed by treatment, such as activation of DNA repair system, anti-apoptotic mechanisms, acquisition of quiescent state and Epithelial-mesenchymal transition, increased drug efflux capacity, hypoxic environment, protection by the CSC niche, overexpression of stemness related genes, and immune surveillance. Complete elimination of CSCs seems to be the main target for achieving tumor control and improving overall survival for cancer patients. This review will focus on the multi-factorial mechanisms by which CSCs are resistant to radiotherapy and chemotherapy in HNSCC, supporting the use of possible strategies to overcome therapy failure
Recent advances in porous adsorbent assisted atmospheric water harvesting: a review of adsorbent materials
No full textWater shortage is an increasing threat to humankind. Porous sorbent assisted atmospheric water harvesting (psaAWH) has emerged as an effective technological countermeasure. In this review, we summarize the types of porous adsorbents used in psaAWH and provide an overview of their states of development. The water adsorption mechanism and the processes associated with each material are analyzed, and the application prospects of the adsorbents are evaluated. The effect of the inherent properties (pore size, functional group, etc.) of the adsorbent on the water harvesting performance is also discussed. Further, we focus on the water adsorption/desorption kinetics of the adsorbents and outline various methods to improve the kinetics. At this stage, there are many strategies for improving the kinetics of the adsorbent, which in turn influences the adsorption process and intra/inter-crystalline diffusion. However, there is still limited research on the transport of water molecules in microporous adsorbents for psaAWH. Thus, this aspect is re-examined herein from a new perspective (superfluidity) in the review. Based on the discussion, we can reasonably infer that water molecule superfluidity can exist in nanoconfined channels, thus promoting the rapid transport of water molecules. The formation of water superfluidity is a feasible strategy for improving the intracrystalline diffusion of the psaAWH adsorbent. Finally, we consider the future developments and challenges of psaAWH in detail. We think this review can serve as a guide for further research in this ever-expanding field
Health risk assessment of BTEX exposure at roadside and on-road traveling route in Bangkok Metropolitan Region
No full textExposure to high levels of benzene, toluene, ethylbenzene, and xylenes (BTEX) poses health risks in high-traffic urban areas. BTEX exposure at two microenvironments, the roadside and along the traveling routes, within urban and suburban areas of the Bangkok Metropolitan Region was examined to assess cancer and noncancer risks. The lifetime cancer risk (LCR) for benzene and noncancer hazard index (HI) for all BTEX compounds were evaluated for adult male and female groups (drivers, passengers, and street vendors) in two scenarios: average case and worst case. With the assumption of negligible exposure outside the two considered microenvironments, the pickup drivers had the highest LCR and HI. Higher exposure risks were found in urban areas than in the suburbs and among men than females. Higher toluene levels were found at all monitoring sites in two microenvironments, but benzene was the most important in causing noncancer risk. The HI for all target groups ranged from 8.5E-03 to 4.0E-01, indicating a low noncancer risk from BTEX exposure (HI < 1). The LCR caused by benzene exposure ranged from 1.7E-06 to 7.2E-05, which is higher than the United States EPA most health-protective limit (1E-06). Further research should include other microenvironments by assessing the 24-hour exposure of all considered groups
Greenhouse gas emissions and offset potential from sugarcane straw for bioenergy production in Brazil
No full textThis study aims to assess the additional Greenhouse gas (GHG) emissions affected by straw removal from the soil surface in sugarcane areas, including measurement of short-term soil CO2-C emissions plus emissions associated with the recovery and transport operations of straw bales until to the industry gate (diesel emissions) and estimated soil N2O emission, comparing with leaving all straw on the soil surface. Taking into account the main sources evaluated (soil CO2, diesel and N2O from straw), the total additional GHG emissions from the recovery of 6.9 Mg Dry Matter ha-1 (27%) was estimated at 1423 kg CO2eq ha-1, resulting in a carbon footprint of 206.2 kg CO2eq per megagram (Mg) of straw recovered. Applying the parameters cited in this study for electricity generation (GHG emission and offset potential), our results showed an additional GHG emission of (+) 860 kg CO2eq ha-1. Applying the same parameters for second generation (2G) ethanol production replacing gasoline, an avoided GHG emission of (-) 2316 kg CO2eq ha-1 could be achieved. The route of recovering 27% of sugarcane straw from the soil surface through bale system for bioelectricity production using the technical parameters and industrial efficiency rate of this case study resulted in a C footprint of 347 kg CO2eq MWh-1. Improving the efficiency rate for straw conversion in bioelectricity based on its lower heating value could reduce its C footprint to 62.26 kg CO2eq MWh-1 produced. For sugarcane straw recovery at the first cutting cycle in clay soil, the option of producing ethanol 2G could offset GHG emissions once replacing fossil gasoline, resulting in a C footprint of 0.86 kg CO2eq L-1 of 2G ethanol in the agricultural phase, an option to contribute to better sustainability of sugarcane straw recovery, supporting renewable and sustainable bioenergy systems, and reducing the impacts of Global Climate Change
Ecological and health risks of polycyclic aromatic hydrocarbons in the sediment core of Phayao Lake, Thailand
No full textPolycyclic aromatic hydrocarbons (PAHs) in sediment cores from Phayao Lake were investigated in terms of their concentration, distribution, and potential effects on the environment and human health. The concentration of Σ16PAHs ranged from 77.6 to 1251.1 ng g-1. Additionally, low molecular weight PAHs (two or three fused aromatic rings) were dominant, indicating that the main source of PAHs is the incomplete combustion of organic sources. The toxic equivalent quantities (TEQs) of 16 PAHs varied from 2.67 to 155.09 ng g-1, with an average of 38.29 ± 46.69 ng g-1. Furthermore, the TEQs of 9 known carcinogenic PAHs averaged 20.77 ± 30.63 ng g-1. B[a]P had the highest TEQ, followed by D[a,h]A and B[k]F, with values of 16.93 ± 25.49, 13.89 ± 15.37 and 2.12 ± 3.64, respectively. The RQ(NCs) of ΣPAHs (RQΣPAHs(NCs)) ranged from 1.65 × 10-4 to 6.27 × 10-1 with an average value of 1.18 × 100 ± 1.52 × 100. Moreover, RQ(NCs) was less than 1 for individual PAHs, indicating a minor risk. However, RQ(MPCs) was less than 1 for individual PAHs, indicating a moderate risk. The results showed a significant incremental lifetime cancer risk (ILCR) from sediment-bound PAHs with dermal absorption, followed by ingestion and inhalation, as the prevalent route of exposure. The measured ILCR values of all PAHs were less than 10-6 for both adults and children, which were lower than the baseline value, indicating that each PAH poses a low risk of cancer to humans. This study provides information for control and preventive actions to limit future PAH pollution in Phayao Lake
The neurobiology of targeted muscle reinnervation for post-amputation pain
No full textTargeted muscle reinnervation (TMR) is a peripheral nerve procedure that can prevent and treat postamputation pain. The nerve transfer allows for organized nerve regeneration and repair after amputation surgery. The procedure can successfully prevent neuromas despite large size mismatches between the donor and recipient nerves. Here, we discuss the fundamentals of peripheral nerve injury and regeneration as it pertains to TMR. We propose axonal pruning to explain axon behavior when there are large size mismatches between transferred nerves. Given the increasing use of TMR for amputees, future studies should investigate the basic science of peripheral nerves in TMR. Advances in this field have the potential to significantly improve clinical outcomes for these patients
Efficacy and safety of a 0/1-h high-sensitivity cardiac troponin I (hs-cTnI) protocol to rule out acute coronary syndrome over a one-year period
No full textAim: Evaluate the diagnostic and prognostic performance of the ESC 0/1H Algorithm and its utility in safely discharging patients with suspected Acute Coronary Syndrome (ACS) in the Emergency Department. Methods: This analysis is a retrospective cohort study of 3,156 patients presenting to an academic medical center emergency department (ED) between May 20, 2019 and May 31, 2020. After completing the Beckman Coulter Access High Sensitivity Troponin I (hs-TnI) assay per current institution protocol (T0, T1H, T3H), patients identified to have symptoms concerning ACS were retrospectively analyzed using the ESC 0/1H Algorithm to assess the safety and efficacy of a rule-out algorithm for early discharge. Results: The negative predictive value (NPV) of the protocol (T0 < 6 pg/mL; or females with T0 ≤ 15 pg/mL and T1 ≤ 15 pg/mL; or males with T0 ≤ 20 pg/mL and T1 ≤ 20 pg/mL) was 99.4% (95%CI: 99.0-99.7%) for acute myocardial injury at the initial ED visit (index ED visit) and/or 30-day cardiac-related death. The negative likelihood ratio was 0.08 (95%CI: 0.05%-0.13%), and the specificity was 86.3% (95%CI: 85.0-87.5%).Conclusion: The protocol was found to have a NPV greater than 99% and a negative likelihood ratio of 0.08, suggesting it is safe to use for patients presenting to the ED with ACS symptoms no matter the time of symptom onset
Data sources:
Access Repository Dashboard
Do you manage OAE Publishing (via Crossref)? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!