Recent advances in structure and reactivity of dissolved organic matter: radiation chemistry of non-isolated natural organic matter and selected model compounds

The importance of natural organic matter (NOM) as a source of carbon in natural waters, as the source of reactive oxygen species, or for the complications its presence causes in treatment of natural waters, is undeniable. Recent studies have also pointed to the major photochemical role of triplet excited state of natural organic matter in the environmental fate of pharmaceutical and personal care products (PPCPs) in waters. However, the characterization of NOM is problematic due to its complex molecular structure. One approach to better understand NOM chemistry is the use of model compounds. As the condensation of a plant's phenolic compounds leads to humification and the formation of NOM, a structurally broad group of nine phenolic compounds were selected as model compounds for this study. With methods used in the discipline of radiation chemistry, the oxidative chemistry and transient spectra of these phenols were studied. In addition, the oxidative chemistry and transient spectra of a sample of NOM from the Black River, North Carolina, USA, was characterized. This natural water sample was used as received and represents the first studies of non-isolated NOM by pulsed radiolysis. The results of the transient spectra of the NOM revealed that the radical intermediates were very long lived. This phenomenon was not captured using the nine model compounds suggesting that more complex compounds are needed to further our understanding of the oxidation chemistry of NOM.     

Seaweed sap: a sustainable way to improve productivity of maize in North-East India

The average productivity of Maize in the north-east hill region of India is very low (1.50 t/ha) mainly owing to cultivation under nutrient-starved conditions. Practical technologies have been developed to cultivate two commercially important seaweeds, viz. Kappaphycus alvarezii and Gracilaria edulis in tropical waters. The sap of these seaweeds has turned out to be a low-cost potent plant biostimulant when applied as foliar spray. A field experiment was conducted using different concentrations of both the seaweed saps in a research farm at Umiam, Meghalaya to study their impact on growth, yield and quality of maize. Results indicated that both the seaweed saps significantly improved the grain yield (10.5–13.1%), carbohydrate (12.3–17.4%) and protein content (4.8%) of maize over and above the control which received the recommended dose of fertilizers only. Thus, these seaweed saps are proved to be an eco-friendly means for enhancing maize productivity and quality in this economically backward region.     

Controlled release of local anesthetic from calcium phosphate bone cements

Novel lidocaine containing calcium phosphate bone cements have been developed. Lidocaine release kinetics of these cements have been evaluated.Calcium phosphate cements have a great potential for local drug delivery. Release of local anesthetic, such as lidocaine, at the implant site can be useful for reducing pain immediately after implantation.In this work a local anesthetic – lidocaine hydrochloride – was incorporated into α-tricalcium phosphate cement. Lidocaine release profile was dependent on cement components used. All cements were characterized by an initial burst release, which can be correlated with cement pH values, followed by gradual drug release. Drug release continued for up to 6 days and was slower, if cement pH was higher. Addition of lidocaine hydrochloride accelerated setting and changed microstructure of the set cement.     

SCALE-UP OF HOLLOW FIBER REACTOR SYSTEMS

Hollow fiber reactors have been developed for many biochemical and biomedical applications. In the study of these reactor systems, we have used single fiber reactors as a prototype for the larger hollow fiber cartridges. Experiments using single fibers have been conducted to obtain conversion data for reactor scale-up. We present a model for predicting conversions in bench-scale hollow fiber cartridges using these single fiber data. The model is compared to experimental conversion data and is shown to be a valuable design tool.     

Multisensory teamwork: using a tactile or an auditory display to exchange gaze information improves performance in joint visual search

In joint tasks, adjusting to the actions of others is critical for success. For joint visual search tasks, research has shown that when search partners visually receive information about each other’s gaze, they use this information to adjust to each other’s actions, resulting in faster search performance. The present study used a visual, a tactile and an auditory display, respectively, to provide search partners with information about each other’s gaze. Results showed that search partners performed faster when the gaze information was received via a tactile or auditory display in comparison to receiving it via a visual display or receiving no gaze information. Findings demonstrate the effectiveness of tactile and auditory displays for receiving task-relevant information in joint tasks and are applicable to circumstances in which little or no visual information is available or the visual modality is already taxed with a demanding task such as air-traffic control. Practitioner Summary: The present study demonstrates that tactile and auditory displays are effective for receiving information about actions of others in joint tasks. Findings are either applicable to circumstances in which little or no visual information is available or when the visual modality is already taxed with a demanding task.     

Understanding Nanomaterial Biotransformation: An Unmet Challenge to Achieving Predictive Nanotoxicology

More than a decade has passed since the first concepts of predictive nanotoxicology were formulated. During this time, many advancements have been achieved in multiple disciplines, including the success stories of the fiber paradigm and the oxidative stress paradigm. However, important knowledge gaps are slowing down the development of predictive nanotoxicology and require a mutidisciplinary effort to be overcome. Among these gaps, understanding, reproducing, and modeling of nanomaterial biotransformation in biological environments is a central challenge, both in vitro and in silico. This dynamic and complex process is still a challenge for today's bioanalytics. This work explores and discusses selected approaches of the multidisciplinary efforts taken in the last decade and the challenges that remain unmet, in particular concerning nanomaterial biotransformation. It highlights some future advancements that, together, can help to understand such complex processes and accelerate the development of predictive nanotoxicology.     

Transdermal Delivery of 2-PAM as a Tool to Increase the Effectiveness of Traditional Treatment of Organophosphate Poisoning

For the first time, the efficacy of post-exposure treatment of organophosphate (OP) poisoning was increased by transdermal delivery of acetylcholinesterase (AChE) reactivator pyridine-2-aldoxime methochloride (2-PAM) as a preventive countermeasure. By selecting the optimal ratio of components, classical transfersomes (based on soybean phosphatidylcholine and Tween 20) and modified transfersomes (based on soybean phosphatidylcholine, Tween 20 and pyrrolidinium cationic surfactants with different hydrocarbon tail lengths) were obtained for 2-PAM encapsulation. Transfersomes modified with tetradecylpyrrolidinium bromide showed the best results in encapsulation efficiency and sustained release of 2-PAM from vesicles. Using Franz cells, it was found that the incorporation of surfactants into PC liposomes results in a more prolonged release of 2-PAM through the rat skin. Transfersomes containing 2-PAM, after exhaustive physical and chemical characterization, were embedded in a gel based on Carbopol^® 940. A significantly high degree of erythrocyte AChE reactivation (23 ± 7%) was shown for 2-PAM in unmodified transfersomes in vivo. Preliminary transdermal administration of 2-PAM 24 h before emergency post-exposure treatment of OP poisoning leads to an increase in the survival rate of rats from 55% to 90%.     

VOC emission reduction and energy efficiency in the flexible packaging printing processes: analysis and implementation

Volatile organic compound (VOC) emissions into the atmosphere are among the primary environmental problems caused by flexible packaging printing plants. Since 1999, VOC emissions from the use of solvents in various technological processes have been limited by the volatile organic compounds solvents emissions directive, and by directive 2010/75/EU on industrial emissions since 2010. Thus, flexible packaging plants require processing technologies or other solutions to ensure compliance with these requirements. In this paper, combined VOC pollution prevention and treatment alternatives were suggested and were evaluated for their technical, environmental, and economic feasibility. A flexible plastic packaging company that produces over 1920 t/year of plastic packaging for the food industry was selected for detailed analysis. The material and energy flow analysis shows that VOC emissions from the main technological processes reached 112.2 kg/t of production, and a considerable amount of energy (up to 771.6 kWh/t of production) was used. Three integrated pollution prevention and control (IPPC) alternatives of the five analysed in this study were selected and implemented within the company to reduce its VOC emissions and energy consumption. The results indicate that after the implementation of the three suggested economically reasonable IPPC alternatives (replacement of solvent-based with water-based inks; modernisation of the ventilation and lighting system), the VOC emissions decreased to 8.4 kg/t (92.5%) and the total energy consumption for the production of 1 t of flexible packaging decreased to 605.6 kWh/t (21.5%). This study shows that IPPC methods not only significantly reduces VOC emissions from flexible packaging printing processes, but also saves energy and raw materials, and reduces costs.     

Pulsed Ligh inactivation of Listeria innocua on food packaging materials of different surface roughness and reflectivity

Inactivation of Listeria innocua on food packaging materials by Pulsed Light (PL) treatment was investigated. Coupons of low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene-laminated ultra-metalized polyethylene terephthalate (MET), polyethylene-coated paperboard (TR), and polyethylene-coated aluminum foil paperboard laminate (EP) were inoculated with L. innocua cells in stationary growth phase. Inoculated coupons (∼8 CFU/coupon) were treated with Pulsed Light fluence of up to 8.0 J/cm², and survivors were determined. Reductions up to 7.2 ± 0.29, 7.1 ± 0.06, 4.4 ± 0.85, 4.5 ± 1.32, and 3.5 ± 0.82 log CFU/coupon were obtained on LDPE, HDPE, MET, TR, and EP, respectively. Inactivation data were used to determine Weibull kinetic parameters and predict inactivation in a wide range of fluence. Increasing surface reflectivity and surface roughness appeared to induce lower inactivation. Minimal surface heating was observed for all materials except MET, on which significant heating occurred. These results demonstrate the potential of Pulsed Light as an effective method for decontaminating food packaging materials.