Performance enhancement of a thermoelectric harvester with a PCM/metal foam composite

The present numerical investigation examines the performance improvement of thermoelectric generators (TEGs) by using phase change materials (PCM) and porous medium. Due to the high latent heat of PCMs, both sides of the TEG were filled with paraffin RT35 (on the cold-side) and paraffin RT69 (on the hot-side). The PCM in the cold-side of the TEG was used as a heat-sink whereas the PCM in hot-side of the TEG was used to reduce the output voltage fluctuations. Since the system was periodically subjected to heat flux from an external heat source, the paraffin in the hot-side of the TEG was also used to generate a continuous thermal heat when the heat source was cut-off. To increase the thermal conductivity of the phase change material, this investigation studied the effect of using the copper porous medium with different porosities (0.80, 0.90, and 0.95) and three different pores per inches (PPI) as 10, 20, and 40. The results show that the use of porous on the cold-side of the TEG produces more electrical energy and output voltage compared to (i) having porous medium on the hot-side and (ii) using PCM without porous medium on both sides of the thermoelectric generator. Furthermore, the results indicated that the TEG performance enhanced by increasing PPI and reducing porosity. As a result, by increasing the PPI from 10 to 40 (at 0.80 porosity) and by reducing porosity from 0.95 to 0.80 (at PPI 20), the electricity generated increases by 13.57 and 5.36%, respectively

Cancer treatment-related neuropathic pain:proof of concept study with menthol—a TRPM8 agonist

PURPOSE: Effective treatment of neuropathic pain without unacceptable side effects is challenging. Cancer sufferers increasingly live with long-term treatment-related neuropathic pain, resulting from chemotherapy-induced peripheral neuropathy (CIPN) or surgical scars. This proof-of-concept study aimed to determine whether preclinical evidence for TRPM8 ion channels in sensory neurons as a novel analgesic target could be translated to clinical benefit in patients with neuropathic pain, using the TRPM8 activator menthol. PATIENTS AND METHODS: Patients with problematic treatment-related neuropathic pain underwent a baseline assessment using validated questionnaires, psychophysical testing, and objective functional measures. The painful area was treated with topical 1 % menthol cream twice daily. Assessments were repeated at 4–6 weeks. The primary outcome was the change in Brief Pain Inventory total scores at 4–6 weeks. Secondary outcomes included changes in function, mood and skin sensation. RESULTS: Fifty-one patients (female/male, 32/19) were recruited with a median age of 61 (ranging from 20 to 89). The commonest aetiology was CIPN (35/51), followed by scar pain (10/51). Thirty-eight were evaluable on the primary outcome. Eighty-two per cent (31/38) had an improvement in total Brief Pain Inventory scores (median, 47 (interquartile range, 30 to 64) to 34 (6 to 59), P < 0.001). Improvements in mood (P = 0.0004), catastrophising (P = 0.001), walking ability (P = 0.008) and sensation (P < 0.01) were also observed. CONCLUSION: This proof-of-concept study indicates that topical menthol has potential as a novel analgesic therapy for cancer treatment-related neuropathic pain. Improvements in patient-rated measures are supported by changes in objective measures of physical function and sensation. Further systematic evaluation of efficacy is required

Role of Lipids in Spheroidal High Density Lipoproteins

We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules surrounding the lipid compartment. The present models are the first ones among computational studies where the size and lipid composition of HDL are realistic, corresponding to human serum HDL. We focus on the role of lipids in HDL structure and dynamics. Particular attention is paid to the assembly of lipids and the influence of lipid-protein interactions on HDL properties. We find that the properties of lipids depend significantly on their location in the particle (core, intermediate region, surface). Unlike the hydrophobic core, the intermediate and surface regions are characterized by prominent conformational lipid order. Yet, not only the conformations but also the dynamics of lipids are found to be distinctly different in the different regions of HDL, highlighting the importance of dynamics in considering the functionalization of HDL. The structure of the lipid droplet close to the HDL-water interface is altered by the presence of apoA-Is, with most prominent changes being observed for cholesterol and polar lipids. For cholesterol, slow trafficking between the surface layer and the regimes underneath is observed. The lipid-protein interactions are strongest for cholesterol, in particular its interaction with hydrophobic residues of apoA-I. Our results reveal that not only hydrophobicity but also conformational entropy of the molecules are the driving forces in the formation of HDL structure. The results provide the first detailed structural model for HDL and its dynamics with and without apoA-I, and indicate how the interplay and competition between entropy and detailed interactions may be used in nanoparticle and drug design through self-assembly