Carbon fibre reinforced shape memory polymer composites for deployable space habitats

Intelligent material shape memory polymers (SMPs) and their composites are capable of memorizing and recovering the original shape upon exposure to a particular external stimulus. This paper presents the mechanical properties, thermomechanical behaviour and the shape memory characteristics of 0/90 woven carbon fibre reinforced shape memory composite. The results revealed that the superlative mechanical properties of carbon fibres as a reinforcement has enhanced the strength of the SMP composite (SMPC) to be applicable for space engineering innovations. Furthermore, the recovery behaviour of 90º bended SMPC specimens have been investigated by exposing to heated air and near infraredradiation. Both stimulus methods have shown almost 98% shape recovery. In addition, a model of a cubic deployable structure has been fabricated and respective shape programming and recovery behaviours have been investigated based on the enclosed volume. Interestingly, the deployable structure has been programmed in to almost three times smaller volume and very nearly recovered to its original shape under vacuumed conditions. Accordingly, the carbon fibre reinforced SMPCs can be used to produce deployable space habitats to fabricate on earth, compress and pack in a spacecraft, transport to an outer space location and ultimately deploy in to the original shape

AWARENESS OF USAGE OF SUNSCREENS AMONG SCHOOL CHILDREN IN KANDY, SRI LANKA

Objective: The objective of this research was to evaluate the awareness of usage of sunscreens among school children in Kandy, Sri Lanka.Methods: School children (138) who do outdoor sports were recruited from six schools. Knowledge and attitudes towards the usage and application of sunscreens were assessed using a researcher administered questionnaire. Statistical analyses were done using Statistical Package for the Social Science (SPSS version-16).Results: Among the school children who do outdoor sports, 71 (51.4%) of participants used sunscreens and 67 (48.6%) of participants did not use sunscreens.Conclusion: According to the results most of the school children have a lack of knowledge, attitudes and practice towards the usage of sunscreens

Damage onset analysis of optimized shape memory polymer composites during programming into curved shapes

The unique shape memorizing ability of shape memory polymers (SMPs) and their fibre reinforced composites have offered the prospect of remedying challenging, unsolved engineering applications. Interestingly, research integrating deformable shape memory polymer composites (SMPCs) in prefabricated modular constructions, deployable outer space structures and other compactable structural components have emerged in the recent past. To ensure effective use in strength demanding applications, SMPC components must possess better mechanical properties. Increased fibre content in SMPCs will improve mechanical properties but can adversely affect the shape memory effect (SME), increasing the possibility of material damage when programming into curved shapes and bends. This will degrade the strength capacity of SMPCs in their applications. This paper details a complete study performed on this critical effect optimizing SMPC properties by means of a 3×3 Taguchi array. The study also provides an experimental framework demonstrating how these undesirable effects can be mitigated coupled with an ABAQUS finite element analysis (FEA) damage prediction strategy. Interestingly, the compression side of the specimen was found to be the most critical location prone to programming damage. In addition, a compressive stress level of 70 MPa was found to be the damage onset stress (σo) point for programming using FEA, and correlated with experimental results. The proposed experimental and FEA framework will enhance future SMPC component design, allowing researchers to predict the possibility of programming damage numerically, saving time and cost. We believe that these findings will aid researchers seeking to develop strong and efficient functional SMPCs for future engineering applications

Whole-organism phenotypic screening methods used in early-phase anthelmintic drug discovery

Diseases caused by parasitic helminths (worms) represent a major global health burden in both humans and animals. As vaccines against helminths have yet to achieve a prominent role in worm control, anthelmintics are the primary tool to limit production losses and disease due to helminth infections in both human and veterinary medicine. However, the excessive and often uncontrolled use of these drugs has led to widespread anthelmintic resistance in these worms - particularly of animals - to almost all commercially available anthelmintics, severely compromising control. Thus, there is a major demand for the discovery and development of new classes of anthelmintics. A key component of the discovery process is screening libraries of compounds for anthelmintic activity. Given the need for, and major interest by the pharmaceutical industry in, novel anthelmintics, we considered it both timely and appropriate to re-examine screening methods used for anthelmintic discovery. Thus, we reviewed current literature (1977-2021) on whole-worm phenotypic screening assays developed and used in academic laboratories, with a particular focus on those employed to discover nematocides. This review reveals that at least 50 distinct phenotypic assays with low-, medium- or high-throughput capacity were developed over this period, with more recently developed methods being quantitative, semi-automated and higher throughput. The main features assessed or measured in these assays include worm motility, growth/development, morphological changes, viability/lethality, pharyngeal pumping, egg hatching, larval migration, CO2- or ATP-production and/or enzyme activity. Recent progress in assay development has led to the routine application of practical, cost-effective, medium- to high-throughput whole-worm screening assays in academic or public-private partnership (PPP) contexts, and major potential for novel high-content, high-throughput platforms in the near future. Complementing this progress are major advances in the molecular data sciences, computational biology and informatics, which are likely to further enable and accelerate anthelmintic drug discovery and development

Hydro-Meteorological Disaster Incidents and Associated Weather Systems in Sri Lanka

This paper presents a comprehensive seasonal analysis of disaster incidents with their associated weather systems happened in Sri Lanka since 1907 to 2019. Disaster incidents and weather records were collected from different reliable sources and analysed with the observed weather systems to understand the formation and development of the weather systems. According to the observations, frequent hydro-meteorological hazards experienced by the country are extreme winds, floods, and landslides. The seasonal analysis shows that majority of these hydro-meteorological disasters have occurred during the southwest monsoon, where the weather was mainly dominated by the monsoon winds entering from the southwest of Sri Lanka which creates torrential rainfall mainly in the wet zone of the country. The frequency of formation of depression and deep depression, from 1907 to 2019 shows that most of these are formed in the Bay of Bengal (BoB), North Indian Ocean, from October to January while having the highest frequency in November followed by December. The study will help to understand the possible damages, and thereby help the community to be prepared for such future hazards. The need for a central platform for generating timely impact-based warnings and helping the community to act was also identified. Further, the census block can be suggested as the smallest; Micro-Geographic Incident Response Unit (MG-IRU) to grant the decision-making power and connect the institution and community in the disaster risk management process.</p

SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohort study

This article is accompanied by an editorial by Marshall and Duggan. Anaesthesia 2022; 77: 3–6.SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1–6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARSCoV- 2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARSCoV- 2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1–2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2–3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9–3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality (5.4 (95%CI 4.3–6.7)). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.COVIDSurg Collaborative and GlobalSurg Collaborative (Australia: Daniel Cox ... Hidde M Kroon ... Christina McVeay ... Matheesha Herath ... Luke Traeger ... Robert Fitridge ... Tarik Sammour ... et al.

BIOLOGICAL AND CHEMICAL PROPERTIES OF "VERMIWASH", NATURAL PLANT GROWTH SUPPLEMENT FOR TEA, COCONUT AND HORTICULTURAL CROPS

Earthworms have been well exploited in agriculture worldwide inmaximizing crop production for many years. Amongst vermin-technology(Vermitech) practices, Vermiwash (Vw) has shown its field efficacy withmany crops. Vw is the wash of earthworm's celomic fluid and calcareouslayer and the watery extract of the bedding materials, which is known tocontain ample amounts of soluble macro and micronutrients, natural growthhormones, beneficial microbes, vitamins and amino acids etc. andnematicidal properties. However, the attributes to beneficial agronomicvalues of Vw have not yet been scientifically validated fully although thispractice is extensively being expanded in India and Sri Lanka. Therefore, thepresent study investigated the biological and chemical properties of elevensources of Vw resulted from different earthworm species and raw materials indifferent farms in Sri Lanka. Vw was tested as a source for hydroponics forlettuce in comparison with the Albert solution. The efficacy of regular foliarand soil applications of Vw on bush bean (Variety: Top crop), tomato(Variety: Thilina), nursery tea (cultivar: TRI 4071) and coconut (Variety:DxT) was also evaluated in comparison with vermicompost and conventionalchemical inputs in a series of bioassays.The results of analyses revealed varying levels of biological and chemicalproperties of the test samples but within the optimal range for plant growth.Vw exhibited significantly lower levels of N, P, K but was rich in Ca, Mg,Zn, Fe and Mn; pH and CEC were also in the required ranges. Vwsignificantly (p=0.05) influenced the soil microbial biomass althoughindividual microorganisms were not identified; microbial biomass of Vw andcontrol were estimated as 4.95 and 3.20 x 10-3 mg C02/day/25g soilrespectively. Vw proved as a better alternate source to Albert solution forlettuce growth under hydroponic culture. The root length, root and shootbiomass and total leaf area of bush bean were significantly (p=0.05) affectedby Vw application compared to that of vermin-compost and synthetic fertilizer treatments. In nursery tea, Vw application lead to comparativelygreater callusing of tea cuttings but the increase in root formation and shootgrowth was not significant. Vw application boosted growth of coconutseedlings. However, no positive responses were seen with tomato.The data suggested the potential exploitation of Vw in home gardening,indoor and container planting, biodynamic and organic farming etc. as afarmer friendly, culturally sensitive and economically viable natural product.Further work on attributes to plant growth such as determination of growthhormones, different doses and mass production of uniform quality Vw usingdifferent earthworm species and raw materials etc. would strengthen itssustainable use as an alternative growth supplement

Importance of heterogeneity in Porhyromonas gingivalis lipopolysaccharide lipid A in tissue specific inflammatory signaling

Lipopolysaccharide (LPS) of Porphyromonas gingivalis exists in at least two known forms, O-LPS and A-LPS. A-LPS shows heterogeneity in which two isoforms designated LPS1435/1449 and LPS1690 appear responsible for tissue specific immune signalingpathways activation and increased virulence. The modification of lipid A to tetra-acylated1435/1449 and/or penta-acylated1690 fatty acids indicates poor growth conditions and bioavailability of hemin. Hemin protects P. gingivalis from serum resistance and the lipid A serves as a site for its binding. The LPS1435/1449 and LPS1690 isoforms can produce opposite effects on the human Toll-like receptors (TLR) TLR 2 and TLR 4 activation. This enabless P. gingivalis to select the conditions for its entry, survival and that of its co-habiting species in the host, orchestrating its virulence to control innate immune pathway activation and biofilm dysbiosis. Thismini review describes a number of effects that LPS1435/1449 and LPS1690 can exert on the host tissues such as deregulation of the innate immune system, subversion of host cell autophagy, regulation of outer membrane vesicle production and adverse effects on pregnancy outcome. The ability to change its LPS1435/1449 and/or LPS1690 composition may enables P. gingivalis to paralyze local pro-inflammatory cytokine production, thereby gaining access to its primary location in periodontal tissue

Influence of the Water Content on the Diffusion Coefficients of Li⁺ and Water across Naphthalenic Based Copolyimide Cation-Exchange Membranes

The transport of lithium ions in cation-exchange membranes based on sulfonated copolyimide membranes is reported. Diffusion coefficients of lithium are estimated as a function of the water content in membranes by using pulsed field gradient (PFG) NMR and electrical conductivity techniques. It is found that the lithium transport slightly decreases with the diminution of water for membranes with water content lying in the range 14 < λ < 26.5, where λ is the number of molecules of water per fixed sulfonate group. For λ < 14, the value of the diffusion coefficient of lithium experiences a sharp decay with the reduction of water in the membranes. The dependence of the diffusion of lithium on the humidity of the membranes calculated from conductivity data using Nernst–Planck type equations follows a trend similar to that observed by NMR. The possible explanation of the fact that the Haven ratio is higher than the unit is discussed. The diffusion of water estimated by 1H PFG-NMR in membranes neutralized with lithium decreases as λ decreases, but the drop is sharper in the region where the decrease of the diffusion of protons of water also undergoes considerable reduction. The diffusion of lithium ions computed by full molecular dynamics is similar to that estimated by NMR. However, for membranes with medium and low concentration of water, steady state conditions are not reached in the computations and the diffusion coefficients obtained by MD simulation techniques are overestimated. The curves depicting the variation of the diffusion coefficient of water estimated by NMR and full dynamics follow parallel trends, though the values of the diffusion coefficient in the latter case are somewhat higher. The WAXS diffractograms of fully hydrated membranes exhibit the ionomer peak at q = 2.8 nm⁻1, the peak being shifted to higher q as the water content of the membranes decreases. The diffractograms present additional peaks at higher q, common to wet and dry membranes, but the peaks are better resolved in the wet membranes. The ionomer peak is not detected in the diffractograms of dry membranes.The authors acknowledge financial support provided by the DGICYT (Dirección General de Investigación Cientifíca y Tecnológica) through Grant MAT2011-29174-C02-02