Engineered polysaccharide, Alpha-1,3 Glucan, as a Functional Filler of Rubber Composites

Rubber products represent an essential and highly functional class of performance materials required in many daily applications. However, the increasing interest in enhancing the overall material sustainability of rubber products has accelerated the focus on compatible, lightweight, and environmentally sustainable fillers. As part of the effort to design sustainable rubber composites, enzymatic polymerization-derived polysaccharide fillers, alpha-1,3 glucan, with designed fibrids, platelet and spherical morphology and high crystallinity was employed as a novel sustainable filler system in natural rubber (NR) films. The alpha-1,3 glucan is supplied by International Fragrances and Flavors (IFF), former E.I. DuPont Industrial Biosciences. Initially, lightly crosslinked NR films reinforced with 0 – 10 phr MCG were fabricated using dipping and casting processes. The effect of MCG on the physicochemical properties, chemical stability, and thermo-mechanical properties of the composite films was investigated. In the subsequent project, colloidal alpha-1,3 glucan with spherical morphology was employed as a functional filler of NR coating films. Coating formulations containing NR latex and 10 – 100 phr colloidal alpha-1,3 glucan were prepared and applied to paper substrates at three different thicknesses. The effect of various coating formulations on the barrier properties against water vapor, oxygen, oil as well as on dry and wet mechanical properties were investigated. In order to study the impact of alpha,1-3 glucan’s morphology on the barrier properties of the paper coating, the following studies were conducted. This study employed enzymatically polymerized microcrystalline glucan (MCG) as a functional additive in natural rubber (NR)-based coating formulations. Typically, NR coating formulations containing 0–50 wt. % MCG were fabricated at a constant coating thickness with a constant solid content. The influence of MCG on the wet and dry strength, rheology, adhesion strength, and barrier properties such as moisture, oxygen, and grease barrier of the formulated coatings was investigated. Also, further study on the effect of solid content and low crosslinking on the barrier properties was conducted. The last stage of the study involved a solvent-free, batch mixer-based reactive process to carry out the reaction of ENR with glucan. In order to enhance the degree of dispersion and bonding of polar filler in a nonpolar natural rubber matrix, in situ melt grafting of epoxidized natural rubber (ENR) onto the polysaccharide was employed to achieve enhanced material properties. The process of temperature and shear-mediated melt grafting, in the presence of two catalysts (sodium hydroxide (NaOH) and dicumyl peroxide (DCP)), was investigated. Analytical characterization techniques, including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and solvent swelling, were employed to confirm the formation of covalent bonds between alpha1,3-glucan and ENR. The selected ENR-glucan masterbatch samples were then subjected to melt-mixing with NR formulations to produce NR composites. Overall, this study aimed to develop a sustainable rubber composite with the incorporation of alpha-1,3 glucan as a functional filler targeting dipped rubber, packaging, and footwear applications and indicating the potential of this study in alleviating the environmental pollution induced by traditional polymers

Technology roadmap of micro/nanorobots

Inspired by Richard Feynman’s 1959 lecture and the 1966 film Fantastic Voyage, the field of micro/nanorobots has evolved from science fiction to reality, with significant advancements in biomedical and environmental applications. Despite the rapid progress, the deployment of functional micro/nanorobots remains limited. This review of the technology roadmap identifies key challenges hindering their widespread use, focusing on propulsion mechanisms, fundamental theoretical aspects, collective behavior, material design, and embodied intelligence. We explore the current state of micro/nanorobot technology, with an emphasis on applications in biomedicine, environmental remediation, analytical sensing, and other industrial technological aspects. Additionally, we analyze issues related to scaling up production, commercialization, and regulatory frameworks that are crucial for transitioning from research to practical applications. We also emphasize the need for interdisciplinary collaboration to address both technical and nontechnical challenges, such as sustainability, ethics, and business considerations. Finally, we propose a roadmap for future research to accelerate the development of micro/nanorobots, positioning them as essential tools for addressing grand challenges and enhancing the quality of life

Sustainable natural rubber composites: masterbatch development of epoxidized natural rubber grafted to designed enzymatic polysaccharides

Designed polysaccharides obtained from the enzymatic polymerization of sucrose modified via a solvent free in situ melt grafting process provided appealing rubber composite properties as sustainable rubber filler material.</jats:p

High Barrier Sustainable Paper Coating Based on Engineered Polysaccharides and Natural Rubber

The demand for paper-based packaging solutions as an alternative to incumbent single-use petroleum-based polymers for food packaging applications is ever-increasing. Paper-based packaging enables direct options for recycling and, in the case of inadvertent leakage, avoids the formation of microplastics through natural biodegradation. However, typical paper-based formats do not offer sufficient barrier performance which meets these sustainability objectives. Replacement of the plastic film with paper formats will reduce product shelf-stability and increase food wastage from farm to table. This work employed enzymatically polymerized microcrystalline glucan (MCG) as a functional additive in natural rubber (NR)-based coating formulations. Typically, NR coating formulations containing 0–50 wt % MCG were fabricated at a constant coating thickness with a constant solid content. The influence of the MCG on the wet and dry strength, rheology, adhesion strength, and barrier properties such as moisture, oxygen, and grease barrier of the formulated coatings was investigated. Also, further study on the effect of solid content and light crosslinking on the barrier properties was conducted. The optimized NR/MCG coating displayed promising mechanical properties as well as oxygen and oil barrier properties. Furthermore, light crosslinking of the NR/MCG coating enhances the barrier properties of the paper coating. Overall, the formulated NR/MCG paper coatings exhibited excellent wet strength in conjuncture with outstanding barrier properties, indicating their potential as a sustainable alternative in the food packaging industry

A one-year hospital-based prospective COVID-19 open-cohort in the Eastern Mediterranean region: The Khorshid COVID Cohort (KCC) study

AbstractThe COVID-19 is rapidly scattering worldwide, and the number of cases in the Eastern Mediterranean Region is rising. Thus, there is a need for immediate targeted actions. We designed a longitudinal study in a hot outbreak zone to analyze the serial findings between infected patients for detecting temporal changes from February 2020. In a hospital-based open-cohort study, patients are followed from admission until one year from their discharge (the 1st, 4th, 12th weeks, and the first year). The patient recruitment phase finished at the end of August 2020, and the follow-up continues by the end of August 2021. The measurements included demographic, socio-economics, symptoms, health service diagnosis and treatment, contact history, and psychological variables. The signs improvement, death, length of stay in hospital were considered primary, and impaired pulmonary function and psychotic disorders were considered main secondary outcomes. Moreover, clinical symptoms and respiratory functions are being determined in such follow-ups. Among the first 600 COVID-19 cases, 490 patients with complete information (39% female; the average age of 57±15 years) were analyzed. Seven percent of these patients died. The three main leading causes of admission were: fever (77%), dry cough (73%), and fatigue (69%). The most prevalent comorbidities between COVID-19 patients were hypertension (35%), diabetes (28%), and ischemic heart disease (14%). The percentage of primary composite endpoints (PCEP), defined as death, the use of mechanical ventilation, or admission to an intensive care unit was 18%. The Cox proportional-hazards model for PCEP indicated the following significant risk factors: Oxygen saturation &lt; 80% (HR= 6.3; [CI 95%: 2.5,15.5]), lymphopenia (HR= 3.5; [CI 95%: 2.2,5.5]), Oxygen saturation 80%-90% (HR= 2.5; [CI 95%: 1.1,5.8]), and thrombocytopenia (HR= 1.6; [CI 95%: 1.1,2.5]). This long-term prospective Cohort may support healthcare professionals in the management of resources following this pandemic.</jats:p

A one-year hospital-based prospective COVID-19 open-cohort in the Eastern Mediterranean region: The Khorshid COVID Cohort (KCC) study

The COVID-19 is rapidly scattering worldwide, and the number of cases in the Eastern Mediterranean Region is rising. Thus, there is a need for immediate targeted actions. We designed a longitudinal study in a hot outbreak zone to analyze the serial findings between infected patients for detecting temporal changes from February 2020. In a hospital-based open-cohort study, patients are followed from admission until one year from their discharge (the 1st, 4th, 12th weeks, and the first year). The patient recruitment phase finished at the end of August 2020, and the follow-up continues by the end of August 2021. The measurements included demographic, socio-economics, symptoms, health service diagnosis and treatment, contact history, and psychological variables. The signs improvement, death, length of stay in hospital were considered primary, and impaired pulmonary function and psychotic disorders were considered main secondary outcomes. Moreover, clinical symptoms and respiratory functions are being determined in such follow-ups. Among the first 600 COVID-19 cases, 490 patients with complete information (39% female; the average age of 57±15 years) were analyzed. Seven percent of these patients died. The three main leading causes of admission were: fever (77%), dry cough (73%), and fatigue (69%). The most prevalent comorbidities between COVID-19 patients were hypertension (35%), diabetes (28%), and ischemic heart disease (14%). The percentage of primary composite endpoints (PCEP), defined as death, the use of mechanical ventilation, or admission to an intensive care unit was 18%. The Cox Proportional-Hazards Model for PCEP indicated the following significant risk factors: Oxygen saturation &lt; 80% (HR = 6.3; [CI 95%: 2.5,15.5]), lymphopenia (HR = 3.5; [CI 95%: 2.2,5.5]), Oxygen saturation 80%-90% (HR = 2.5; [CI 95%: 1.1,5.8]), and thrombocytopenia (HR = 1.6; [CI 95%: 1.1,2.5]). This long-term prospective Cohort may support healthcare professionals in the management of resources following this pandemic.</jats:p

A one-year hospital-based prospective COVID-19 open-cohort in the Eastern Mediterranean region: The Khorshid COVID Cohort (KCC) study

The COVID-19 is rapidly scattering worldwide, and the number of cases in the Eastern Mediterranean Region is rising. Thus, there is a need for immediate targeted actions. We designed a longitudinal study in a hot outbreak zone to analyze the serial findings between infected patients for detecting temporal changes from February 2020. In a hospital-based open-cohort study, patients are followed from admission until one year from their discharge (the 1st, 4th, 12th weeks, and the first year). The patient recruitment phase finished at the end of August 2020, and the follow-up continues by the end of August 2021. The measurements included demographic, socio-economics, symptoms, health service diagnosis and treatment, contact history, and psychological variables. The signs improvement, death, length of stay in hospital were considered primary, and impaired pulmonary function and psychotic disorders were considered main secondary outcomes. Moreover, clinical symptoms and respiratory functions are being determined in such follow-ups. Among the first 600 COVID-19 cases, 490 patients with complete information (39% female; the average age of 57±15 years) were analyzed. Seven percent of these patients died. The three main leading causes of admission were: fever (77%), dry cough (73%), and fatigue (69%). The most prevalent comorbidities between COVID-19 patients were hypertension (35%), diabetes (28%), and ischemic heart disease (14%). The percentage of primary composite endpoints (PCEP), defined as death, the use of mechanical ventilation, or admission to an intensive care unit was 18%. The Cox Proportional-Hazards Model for PCEP indicated the following significant risk factors: Oxygen saturation < 80% (HR = 6.3; [CI 95%: 2.5,15.5]), lymphopenia (HR = 3.5; [CI 95%: 2.2,5.5]), Oxygen saturation 80%-90% (HR = 2.5; [CI 95%: 1.1,5.8]), and thrombocytopenia (HR = 1.6; [CI 95%: 1.1,2.5]). This long-term prospective Cohort may support healthcare professionals in the management of resources following this pandemic.Peer ReviewedPostprint (published version