High dielectric constant and high breakdown strength polyimide via tin complexation of the polyamide acid precursor

Polymer dielectrics with ultra-high charge–discharge rates are significant for advanced electrical and electronic systems. Despite the fact that polymers possess high breakdown strength, the low dielectric constant (k) of polymers gives rise to low energy densities. Incorporating metal into polyimides (PI) at the polyamic acid (PAA) precursor stage of the synthetic process is a cheap and versatile way to improve the dielectric constant of the hybrid system while maintaining a high breakdown strength. Here, we explore inclusion of different percentages of Sn as a coordinated complex in a polyimide matrix to achieve metal homogeneity within the dielectric film to boost dielectric constant. Sn–O bonds with high atomic polarizability are intended to enhance the ionic polarization without sacrificing bandgap, a measurable property of the material to assess intrinsic breakdown strength. Enhancements of k from ca. 3.7 to 5.7 were achieved in going from the pure PI film to films containing 10 mol% tin.

Polyimide with high dielectric constant and breakdown strength is synthesized via tin complexation of the polyamide acid precursor. Sn–O bonds with high atomic polarizability are intended to enhance the ionic polarization without sacrificing bandgap.     

Development of a Tissue‐Engineered Lymphatic Graft Using Nanocomposite Polymer for the Treatment of Secondary Lymphedema

Damage of the lymphatic vessels, commonly due to surgical resection for cancer treatment, leads to secondary lymphedema. Tissue engineering approach offers a possible solution to reconstruct this damage with the use of lymphatic graft to re‐establish the lymphatic flow, hence preventing lymphedema. The aim of this study is to develop a tissue‐engineered lymphatic graft using nanocomposite polymer and human dermal lymphatic endothelial cells (HDLECs). A nanocomposite polymer, the polyhedral oligomeric silsequioxane‐poly(carbonate‐urea)urethane (POSS‐PCU), which has enhanced mechanical, chemical, and physical characteristics, was used to develop the lymphatic graft. POSS‐PCU has been used clinically for the world's first synthetic trachea, lacrimal duct, and is currently undergoing clinical trial for coronary artery bypass graft. Two designs and fabrication methods were used to manufacture the conduits. The fabrication method, the mechanical and physical properties, as well as the hydraulic conductivity were tested. This is followed by in vitro cell culture analysis to test the cytocompatibility of HDLEC with the polymer surface. Using the casted extrusion method, the nanocomposite lymphatic graft demonstrates desirable mechanical property and hydraulic conductivity to re‐establish the lymphatic flow. The conduit has high tensile strength (casted: 74.86 ± 5.74 MPa vs. coagulated: 31.33 ± 3.71 MPa; P < 0.001), favorable kink resistance, and excellent suture retention property (casted vs. coagulated, P < 0.05). Cytocompatibility study showed that the POSS‐PCU scaffold supports the attachment and growth of HDLECs. This study demonstrates the feasibility of developing a tissue‐engineered lymphatic graft using the nanocomposite polymer. It displays excellent mechanical property and cytocompatibility to HDLECs, offering much promise for clinical applications and as a new treatment option for secondary lymphedema.     

Mesenchymal Stem Cell (MSCs) Therapy for Ischemic Heart Disease: A Promising Frontier

Although tremendous progress has been made in conventional treatment for ischemic heart disease, it still remains a major cause of death and disability. Cell-based therapeutics holds an exciting frontier of research for complete cardiac recuperation. The capacity of diverse stem and progenitor cells to stimulate cardiac renewal has been analysed, with promising results in both pre-clinical and clinical trials. Mesenchymal stem cells have been ascertained to have regenerative ability via a variety of mechanisms, including differentiation from the mesoderm lineage, immunomodulatory properties, and paracrine effects. Also, their availability, maintenance, and ability to replenish endogenous stem cell niches have rendered them suitable for front-line research. This review schemes to outline the use of mesenchymal stem cell therapeutics for ischemic heart disease, their characteristics, the potent mechanisms of mesenchymal stem cell-based heart regeneration, and highlight preclinical data. Additionally, we discuss the results of the clinical trials to date as well as ongoing clinical trials on ischemic heart disease.     

Preliminary evidence of cannabinoid effects on brain-derived neurotrophic factor (BDNF) levels in humans

Background  Acute and chronic exposure to cannabinoids has been associated with cognitive deficits, a higher risk for schizophrenia and other drug abuse. However, the precise mechanism underlying such effects is not known. Preclinical studies suggest that cannabinoids modulate brain-derived neurotrophic factor (BDNF). Accordingly, we hypothesized that Δ⁹-tetrahydrocannabinol (Δ⁹-THC), the principal active component of cannabis, would alter BDNF levels in humans. Materials and methods  Healthy control subjects (n = 14) and light users of cannabis (n = 9) received intravenous administration of (0.0286 mg/kg) Δ⁹-THC in a double-blind, fixed order, placebo-controlled, laboratory study. Serum sampled at baseline, after placebo administration, and after Δ⁹-THC administration was assayed for BDNF using ELISA. Results  Δ⁹-THC increased serum BDNF levels in healthy controls but not light users of cannabis. Further, light users of cannabis had lower basal BDNF levels. Δ⁹-THC produced psychotomimetic effects, perceptual alterations, and “high” and spatial memory impairments. Implications  The effects of socially relevant doses of cannabinoids on BDNF suggest a possible mechanism underlying the consequences of exposure to cannabis. This may be of particular importance for the developing brain and also in disorders believed to involve altered neurodevelopment such as schizophrenia. Larger studies to investigate the effects of cannabinoids on BDNF and other neurotrophins are warranted.     

Convergence model for effectual prevention and control of zoonotic diseases: a health system study on ‘One Health’ approach in Ahmedabad,India

The complexity and increasing burden of zoonotic diseases create challenges for the health systems of developing nations. Public health systems must therefore be prepared to face existing and future disease threats at the human–animal interface. The key for this is coordinated action between the human and the animal health systems. Although some studies deal with the question of how these two systems interact during unforeseen circumstances such as outbreaks, a dearth of literature exists on how these systems interact on early detection, prevention and control of zoonotic diseases; assessing this problem from the health system perspective in a developing nation adds further complexity. Systems thinking is one of the promising approaches in understanding the factors that influence the system’s complexity and dynamics of health maintenance. Therefore, this study aims to understand the generic structure and complexity of interaction between these actors within the domain of One Health for the effectual prevention and control of zoonotic diseases in India.The present study will be executed in Ahmedabad, located on the Western part of India, in Gujarat state, using a mixed methods approach. For the first step, zoonotic diseases will be prioritised for the local context through semi-quantitative tools. Secondly, utilising semi-structured interviews, stakeholders from the human and animal health systems will be identified and ranked. Thirdly, the identified stakeholders will be questioned regarding the current strength of interactions at various levels of the health system (i.e. managerial, provider and community level) through a quantitative network survey. Fourthly, utilising a vignette method, the ideal convergence strategies will be documented and validated through policy Delphi techniques. Finally, through a participatory workshop, the factors that influence convergence for the control and prevention of zoonotic diseases will be captured.This study will provide a comprehensive picture of the current strength of collaboration and network depth at various levels of the health system. Further, it will assist different actors in identifying the relevance of possible One Health entry points for participation, i.e. it will not only contribute but will also develop a system convergence model for the effectual prevention and control of zoonotic diseases.     

Folie a deux and delusional disorder by proxy: an atypical presentation

Delusion of parasitosis is a rare condition characterised by an individual harbouring the delusion of being infested with insects or parasites. We report a rare and interesting case of delusion of parasitosis presenting as folie a deux, that is, the delusion is shared by both the parents of an 18‐month‐old child, with proxy projection of parental delusion on the child. The case highlights the rare concomitant occurrence of two psychocutaneous disorders and emphasizes the importance of early recognition and appropriate intervention to safeguard the well‐being of the child.