98 research outputs found
Lignin-Modified Phenolic Syntan: A Contributor to Our Bio-Based Solutions
Content:
In order to contribute to a more sustainable leather manufacturing process and leather value chain, in 2016 Smit & zoon started its own designing process of new products through the Bio-Based innovation
platform. As a logical first step, answers to several key questions have been looked for: What is Bio-Based? What is renewable? Which term and method do we use to define the Bio-Based content in the Bio-Based platform? What is biodegradable? How do our current products perform? What is our vision for future products? In the process of answering these questions and guided by the Cradle-to-Cradle (C2C) CertifiedTM program, Material Reutilization Score (MRS) was used to obtain deeper insights into the formulation and environmental performance of our leather chemicals and treated as the basis for the design of new generation bio-based chemicals. Three main focus areas are setting the tone of current activities in the Bio-based platform: 1. increasing the renewable contents of the existing product groups; 2. smart valorization of industrial side streams from biological origin and 3. improving the biodegradability of leather chemicals. While focusing on these topics, it is well-understood that a proper balance needs to be found between cost, sustainability and performance. In the meantime, leatherâs end of life scenario plays a role and needs to be looked at again. One of the first results of this focused approach is our patentpending polyphenolic syntan product, in which industrial lignins are used during the chemical conversion process to replace part of the phenol (40-50 w/w%) used in the production of otherwise 100% petro-based polyphenolic retanning chemicals. We have shown that our innovative technology is compatible with most of the industrial lignins (kraft, soda, organosolv, hydrolysis) from different origins (soft/hard wood, grass, straw). The obtained polyphenolic products have real tanning power and are suitable to be used as retanning agents for various types of leather rendering good organoleptic properties with additional added value of increased bio-based content, improved biodegradability thus a higher MRS. The improved biodegradability of these products can contribute to decrease the effluent treatment load. Moreover, these products can be tailor-made to meet low emission (low free phenol, low free formaldehyde) requirements as well. In addition to the lignin-based polymers, the quickly developing project portfolio within the biobased platform manifests that Smit & zoon is making steady steps towards a largely sustainable leather value chain by 2025.
Take-Away:
Bio-Based products contritbute to a sustainable leather manufacturing process and leather value chain.
Both the raw material renewability and product biodegradability are important parameters to evaluate the environmental impact of leather chemicals.
Smit & zoon has developed a patent-pending bio-based synthan product using industrial lignins to replace part of the petro-based phenols in the production process
NMDA and GABAB (KIR) conductances: The "perfect couple" for bistability
Networks that produce persistent firing in response to novel input patterns are thought to be important in working memory and other information storage functions. One possible mechanism for maintaining persistent firing is dendritic voltage bistability in which the depolarized state depends on the voltage dependence of the NMDA conductance at recurrent synapses. In previous models, the hyperpolarized state is dependent on voltage-independent conductances, including GABAA. The interplay of these conductances leads to bistability, but its robustness is limited by the fact that the conductance ratio must be within a narrow range. The GABAB component of inhibitory transmission was not considered in previous analyses. Here, we show that the voltage dependence of the inwardly rectifying potassium (KIR) conductance activated by GABAB receptors adds substantial robustness to network simulations of bistability and the persistent firing that it underlies. The hyperpolarized state is robust because, at hyperpolarized potentials, the GABAB/KIR conductance is high and the NMDA conductance is low; the depolarized state is robust because, at depolarized potentials, the NMDA conductance is high and the GABAB/KIR conductance is low. Our results suggest that this complementary voltage dependence of GABAB/KIR and NMDA conductances makes them a âperfect coupleâ for producing voltage bistability
6-hydroxydopamine-mediated release of norepinephrine increases faecal excretion of Salmonella enterica serovar Typhimurium in pigs
Salmonella enterica serovar Typhimurium is an animal and zoonotic pathogen of worldwide importance. In pigs, transport and social stress are associated with reactivation and spread of Salmonella Typhimurium infection. The stress-related catecholamine norepinephrine (NE) has been reported to activate growth and virulence factor expression in Salmonella; however the extent to which NE contributes to stress-associated salmonellosis is unclear. We studied the impact of releasing NE from endogenous stores during Salmonella Typhimurium infection of pigs by administration of 6-hydroxydopamine (6-OHDA), which selectively destroys noradrenergic nerve terminals. Treatment of pigs with 6-OHDA 7 or 16 days post-oral inoculation with Salmonella Typhimurium produced elevated plasma NE levels and transiently, but significantly, increased faecal excretion of the challenge strain. Oral administration of NE to Salmonella Typhimurium-infected pigs also transiently and significantly increased shedding; however pre-culture of the bacteria with NE did not alter the outcome of infection. Salmonella has been proposed to sense and respond to NE via a homologue of the adrenergic sensor kinase QseC. A ÎqseC mutant of Salmonella Typhimurium was consistently excreted in lower numbers than the parent strain post-oral inoculation of pigs, though not significantly so. 6-OHDA treatment of pigs infected with the ÎqseC mutant also increased faecal excretion of the mutant strain, albeit to a lesser extent than observed upon 6-OHDA treatment of pigs infected with the parent strain. Our data support the notion that stress-related catecholamines modulate the interaction of enteric bacterial pathogens with their hosts
Impairment in work and activities of daily life in patients with psoriasis:results of the prospective BioCAPTURE registry
Background: Little is known about the extent of impairments in work and activities of daily life (ADL) in patients with psoriasis, and the influence of contextual factors such as disease-related characteristics and treatment. Therefore, this study aimed to assess these impairments in patients with psoriasis who started using biologicals/small molecule inhibitors. Methods: Using data from the prospective BioCAPTURE registry, we collected patient, disease, and treatment parameters, as well as work/ADL impairments at baseline, 6 and 12 months. Changes in impairment parameters and correlations between impairment and patient/disease characteristics were assessed using generalized estimating equations. Results: We included 194 patients in our analysis. After biological initiation, disease activity decreased significantly (PASI 11.2 at baseline versus 3.9 at 12 months, p < 0.001). Work-for-pay in this cohort was lower than in the Dutch general population (53% versus 67%, p = 0.01). In patients who had work-for-pay, presenteeism improved over time (5% at baseline versus 0% at 12 months, p = 0.04). Up to half of the patients reported impairments in ADL, which did not change over time. Associations between impairments and contextual factors varied, but all impairments were associated with worse mental/physical general functioning. Conclusion: Patients with psoriasis using biologicals are less likely to have work-for-pay. Treatment improves the work productivity of employed patients, but we were unable to detect changes in ADL performance.</p
Impairment in work and activities of daily life in patients with psoriasis: results of the prospective BioCAPTURE registry
Background: Little is known about the extent of impairments in work and activities of daily life (ADL) in patients with psoriasis, and the influence of contextual factors such as disease-related characteristics and treatment. Therefore, this study aimed to assess these impairments in patients with psoriasis who started using biologicals/small molecule inhibitors. Methods: Using data from the prospective BioCAPTURE registry, we collected patient, disease, and treatment parameters, as well as work/ADL impairments at baseline, 6 and 12 months. Changes in impairment parameters and correlations between impairment and patient/disease characteristics were assessed using generalized estimating equations. Results: We included 194 patients in our analysis. After biological initiation, disease activity decreased significantly (PASI 11.2 at baseline versus 3.9 at 12 months, p < 0.001). Work-for-pay in this cohort was lower than in the Dutch general population (53% versus 67%, p = 0.01). In patients who had work-for-pay, presenteeism improved over time (5% at baseline versus 0% at 12 months, p = 0.04). Up to half of the patients reported impairments in ADL, which did not change over time. Associations between impairments and contextual factors varied, but all impairments were associated with worse mental/physical general functioning. Conclusion: Patients with psoriasis using biologicals are less likely to have work-for-pay. Treatment improves the work productivity of employed patients, but we were unable to detect changes in ADL performance
PhotoCORMs: CO release moves into the visible
The potential of carbon monoxide to act as a therapeutic agent is now well-established. Controlled delivery of CO is best achieved using 'CORMs': molecules which release known amounts of carbon monoxide in response to a stimulus. Metal carbonyl complexes will release CO if irradiated with ultraviolet light, but it is only in the past five years that development of true 'photoCORMs' has been explored. Recent exciting developments in this area now show that design of photoCORMs operating well into the visible region is achievable. In this Perspective, we examine the growth of photoCORMs from their origins in the photophysics of metal carbonyls to the latest visible-light agents
- âŠ