Sequential extraction of fucoidan, laminarin, mannitol, alginate and protein from brown macroalgae Ascophyllum nodosum and Fucus vesiculosus

The study involves development of a green biorefinery process for obtaining fucoidan, laminarin, mannitol, alginate and protein from dry and fresh Fucus vesiculosus and Ascophyllum nodosum using hydrochloric acid and a green extraction solvent. After the extraction of fucoidan which was the targeted biomolecule, an extract and by-product (residual biomass) were obtained. The extract was passed through an ultrafiltration membrane, where fucoidan was obtained in the ultrafiltration retentate while ultrafiltration permeate was analysed for laminarin and mannitol. The residual biomass was used for obtaining alginate using ultrasound (20 kHz, 64 % amplitude and 32 min, optimum parameters for alginate extraction based on our previous study). All the samples, showed good results for alginate, laminarin and mannitol, indicating that the by-products can be utilised using this green extraction process. The comparison of both dry and fresh seaweed is relevant from an industry perspective, as fresh seaweed can directly be used for extraction, avoiding drying which adds significantly to the cost of the process. Life cycle impact assessment of the complete seaweed value chain has been carried out to identify the energy demand and key environmental hotspots. This biorefinery process can be used by industry to improve their processes and utilise the by-products generated efficiently.

Fabrication and Evaluation of Filtration Membranes from Industrial Polymer Waste

Polyvinylidene fluoride (PVDF) polymers are known for their diverse range of industrial applications and are considered important raw materials for membrane manufacturing. In view of circularity and resource efficiency, the present work mainly deals with the reusability of waste polymer 'gels' produced during the manufacturing of PVDF membranes. Herein, solidified PVDF gels were first prepared from polymer solutions as model waste gels, which were then subsequently used to prepare membranes via the phase inversion process. The structural analysis of fabricated membranes confirmed the retention of molecular integrity even after reprocessing, whereas the morphological analysis showed a symmetric bi-continuous porous structure. The filtration performance of membranes fabricated from waste gels was studied in a crossflow assembly. The results demonstrate the feasibility of gel-derived membranes as potential microfiltration membranes exhibiting a pure water flux of 478 LMH with a mean pore size of ~0.2 µm. To further evaluate industrial applicability, the performance of the membranes was tested in the clarification of industrial wastewater, and the membranes showed good recyclability with about 52% flux recovery. The performance of gel-derived membranes thus demonstrates the recycling of waste polymer gels for improving the sustainability of membrane fabrication processes.

Preparation of cellulase concoction using differential adsorption phenomenon

Controlled depolymerization of cellulose is essential for the production of valuable cellooligosaccharides and cellobiose from lignocellulosic biomass. However, enzymatic cellulose hydrolysis involves multiple synergistically acting enzymes, making difficult to control the depolymerization process and generate desired product. This work exploits the varying adsorption properties of the cellulase components to the cellulosic substrate and aims to control the enzyme activity. Cellulase adsorption was favored on pretreated cellulosic biomass as compared to synthetic cellulose. Preferential adsorption of exocellulases was observed over endocellulase, while β-glucosidases remained unadsorbed. Adsorbed enzyme fraction with bound exocellulases when used for hydrolysis generated cellobiose predominantly, while the unadsorbed enzymes in the liquid fraction produced cellooligosaccharides majorly, owing to its high endocellulases activity. Thus, the differential adsorption phenomenon of the cellulase components can be used for the controlling cellulose hydrolysis for the production of an array of sugars.

Tobacco use, exposure to second-hand smoke, and cessation training among the third-year medical and dental students in selected Member States of South-East Asia region: a trend analysis on data from the Global Health Professions Student Survey, 2005-2011

BACKGROUND

The Medical and Dental Global Health Professions Student Surveys (GHPSS) are surveys based in schools that collect self-administered data from students on the prevalence of tobacco use, exposure to second-hand smoke, and tobacco cessation training, among the third-year medical and dental students.

MATERIALS AND METHODS

Two rounds of medical and dental GHPSS have been conducted in Bangladesh, India, Myanmar, Nepal, Sri Lanka, and Thailand, among the third-year medical and dental students, between 2005 and 2006 and 2009 and 2011.

RESULTS

The prevalence of any tobacco use among third-year male and female medical students did not change in Bangladesh, India, and Nepal between 2005 and 2006 and 2009 and 2011; however, it reduced significantly among females in Myanmar (3.3% in 2006 to 1.8% in 2009) and in Sri Lanka (2.5% in 2006 to 0.6% in 2011). The prevalence of any tobacco use among third-year male dental students did not change in Bangladesh, India, Nepal, and Thailand between 2005 and 2006 and 2009 and 2011; however, in Myanmar, the prevalence increased significantly (35.6% in 2006 to 49.5% in 2009). Among the third-year female students, a significant increase in prevalence was noticed in Bangladesh (4.0% in 2005 to 22.2% in 2009) and Thailand (0.7% in 2006 to 2.1% in 2011). It remained unchanged in the other three countries. Prevalence of exposure to second-hand smoke (SHS) both at home and in public places, among medical students, decreased significantly in Myanmar and Sri Lanka between 2006 and 2009 and in 2011. Among dental students, the prevalence of SHS exposure at home reduced significantly in Bangladesh, India, and Myanmar, and in public places in India. However, there was an increase of SHS exposure among dental students in Nepal, both at home and in public places, between 2005 and 2011. Medical students in Myanmar, Nepal, and Sri Lanka reported a declining trend in schools, with a smoking ban policy in place, between 2005 and 2006 and 2009 and 2011, while proportions of dental students reported that schools with a smoking ban policy have increased significantly in Bangladesh and Myanmar. Ever receiving cessation training increased significantly among medical students in Sri Lanka only, whereas, among dental students, it increased in India, Nepal, and Thailand.

CONCLUSION

Trends of tobacco use and exposure to SHS among medical and dental students in most countries of the South-East Asia Region had changed only relatively between the two rounds of GHPSS (2005-2006 and 2009-2011). No significant improvement was observed in the trend in schools with a policy banning smoking in school buildings and clinics. Almost all countries in the SEA Region that participated in GHPSS showed no significant change in ever having received formal training on tobacco cessation among medical and dental students.

Linking India Global Health Professions Student Survey data to the World Health Organization Framework Convention on Tobacco Control

The 2003 India Tobacco Control Act (ITCA) includes provisions designed to reduce tobacco consumption and protect citizens from exposure to secondhand smoke. India ratified the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) on February 27, 2005. The WHO FCTC is the world's first public health treaty that aims to promote and protect public health and reduce the devastating health and economic impact of tobacco. The Global Health Professions Student Survey (GHPSS) was developed to track tobacco use among third-year dental, medical, nursing, and pharmacy students across countries. Data from the dental (2005), medical (2006), nursing(2007), and pharmacy (2008) GHPSS conducted in India showed high prevalence of tobacco use and a general lack of training by health professionals in patient cessation counseling techniques. The Ministry of Health and Family Welfare could use this information to monitor and evaluate the existing tobacco control program effort in India as well as to develop and implement new tobacco control program initiatives.

Tobacco water: a special form of tobacco use in the Mizoram and Manipur states of India

BACKGROUND

Tuibur and hidakphu are watery tobacco products made by passing tobacco smoke through water. These have neither been described in the health literature nor are there any reports of epidemiological studies on these products. We collected information on the use of these products in Mizoram and Manipur.

METHODS

We conducted two surveys. In the first, we spoke to personnel involved in tobacco water manufacturing, marketing and sale. In the second, we carried out a house to house survey of adults on the attitude and behaviour towards the use of tobacco products in 25 randomly selected villages each in Aizawl district of Mizoram and Churchandpur district of Manipur.

RESULTS

About 7% of persons surveyed in Aizawl (872 of 12 185) and Churchandpur (139 of 2137) used tobacco water, which is stored and sold in bottles. It is sipped and retained in the mouth for 5-10 minutes and then spat out. Among tobacco water users, about 90% of users in Churchandpur and about 40% in Aizawl sipped tobacco water more than 5 times a day. The use of other tobacco products in both districts was also high.

CONCLUSION

The use of tobacco water has been a part of the culture of some communities in Mizoram and Manipur for a long time. These communities also have a very high incidence of tobacco use. To discourage the use of such tobacco products, these communities should be educated about the harmful effects of tobacco use on a priority.