Single-Component Cellulose Acetate Sulfate Hydrogels for Direct Ink Writing 3D Printing.

Hydrogels, typically favored for 3D printing due to their viscoelasticity, are now trending toward ecofriendly alternatives amid growing environmental concerns. In this study, we crafted cellulose-based hydrogels, specifically employing cellulose acetate sulfate (CAS). By keeping the acetyl group substitution degree (DSacetyl = 1.8) and CAS molecular weight constant, we varied rheological properties by adjusting sulfate group substitution (DSsulfate = 0.4, 0.7, and 1.0) and CAS concentration (2-5 wt %). Rheological characterizations, including shear-thinning, yield stress, and thixotropy, were performed to identify optimal conditions for formulating CAS hydrogel ink in direct ink writing for 3D printing under selected experimental conditions. Based on rheological findings, CAS hydrogels with DSsulfate 0.7 and concentration of 4 wt % was used for 3D printing, with subsequent evaluation of printing metrics. Additionally, the effect of ionic cross-linking using Ca2+ ions on the structural integrity of 3D-printed structures was evaluated, demonstrating effective preservation through reinforced polymer networks. The shrinking and swelling behaviors of the 3D-printed structures were also significantly affected by this ionic cross-linking. Building on these findings, this work could broaden the range of cellulose derivatives available for the preparation of cellulose-based hydrogels for 3D printing.

A novel functional role for the classic CNS neurotransmitters, GABA, glycine, and glutamate, in the kidney: potent and opposing regulators of the renal vasculature.

The presence of a renal GABA/glutamate system has previously been described; however, its functional significance in the kidney remains undefined. We hypothesized, given its extensive presence in the kidney, that activation of this GABA/glutamate system would elicit a vasoactive response from the renal microvessels. The functional data here demonstrate, for the first time, that activation of endogenous GABA and glutamate receptors in the kidney significantly alters microvessel diameter with important implications for influencing renal blood flow. Renal blood flow is regulated in both the renal cortical and medullary microcirculatory beds via diverse signaling pathways. GABA- and glutamate-mediated effects on renal capillaries are strikingly similar to those central to the regulation of central nervous system capillaries, that is, exposing renal tissue to physiological concentrations of GABA, glutamate, and glycine led to alterations in the way that contractile cells, pericytes, and smooth muscle cells, regulate microvessel diameter in the kidney. Since dysregulated renal blood flow is linked to chronic renal disease, alterations in the renal GABA/glutamate system, possibly through prescription drugs, could significantly impact long-term kidney function.NEW & NOTEWORTHY Functional data here offer novel insight into the vasoactive activity of the renal GABA/glutamate system. These data show that activation of endogenous GABA and glutamate receptors in the kidney significantly alters microvessel diameter. Furthermore, the results show that these antiepileptic drugs are as potentially challenging to the kidney as nonsteroidal anti-inflammatory drugs.

Altered urothelial ATP signaling in a major subset of human overactive bladder patients with pyuria.

Overactive Bladder (OAB) is an idiopathic condition, characterized by urgency, urinary frequency, and urgency incontinence, in the absence of routinely traceable urinary infection. We have described microscopic pyuria (≥10 wbc/µl) in patients suffering from the worst symptoms. It is established that inflammation is associated with increased ATP release from epithelial cells, and extracellular ATP originating from the urothelium following increased hydrostatic pressure is a mediator of bladder sensation. Here, using bladder biopsy samples, we have investigated urothelial ATP signaling in OAB patients with microscopic pyuria. Basal, but not stretch-evoked, release of ATP was significantly greater from the urothelium of OAB patients with pyuria than from non-OAB patients or OAB patients without pyuria (<10 wbc/µl). Basal ATP release from the urothelium of OAB patients with pyuria was inhibited by the P2 receptor antagonist suramin and abolished by the hemichannel blocker carbenoxolone, which differed from stretch-activated ATP release. Altered P2 receptor expression was evident in the urothelium from pyuric OAB patients. Furthermore, intracellular bacteria were visualized in shed urothelial cells from ∼80% of OAB patients with pyuria. These data suggest that increased ATP release from the urothelium, involving bacterial colonization, may play a role in the heightened symptoms associated with pyuric OAB patients.

Wood Extractives Promote Cellulase Activity on Cellulosic Substrates.

Deposition of hydrophobic wood extractives and representative model compounds, on the surface of cellulose prior to enzymatic hydrolysis was found to either enhance or inhibit the action of cellulase enzymes. The effect of these compounds was correlated with their chemical structure, which may in part explain the differential effects observed between softwood and hardwood extractives. Specifically, the addition of sterol, enhanced enzymatic hydrolysis of microcrystalline cellulose by 54%, whereas the addition of a triglyceride could inhibit the hydrolysis by 49%. The effects of the different extractives' could be explained by considering their Hansen solubility parameters. The amphiphilic and/or hydrophobic character of model extractives was found to be the variable that affected the deposition of extractives on cellulose surfaces and the eventual adsorption of cellulolytic enzymes on it. The observed beneficial effects of extractives are likely related to a reduction in the irreversible binding of the enzymes on the cellulose surface.

Effective toluene removal from aqueous solutions using fast pyrolysis-derived activated carbon from agricultural and forest residues: Isotherms and kinetics study.

In this study, the production and characterization of activated carbons (ACs) from agricultural and forest residue using physical activation are discussed. Biomass-based biochars produced during fast pyrolysis process is introduced as alternative precursors to produce AC and the integrated process for the co-production of porous adsorbent materials from biochar via the fast pyrolysis process is suggested. Moderate surface areas and good adsorption capacities were obtained from switchgrass (SWG) and pine tops (PT) based AC. The surface areas were 959 and 714 m2/g for SWG- and PT-based AC, respectively. The adsorption capacities using toluene as pollutant for two model systems of 180 and 300 ppm were measured and ranged between 441-711 and 432-716 mg/g for SWG-based and PT-based AC, respectively. The nitrogen adsorptive behavior, Lagergren pseudo-second-order kinetic (PSOK) model and kinetics isotherms studies describe a heterogeneous porous system, including a mesoporous fraction with the existence of a multilayer adsorption performance. The presence of micropores and mesopores in SWG- and PT-based AC suggests potential commercial applications for using pyrolytic biochars for AC production.

Production of single-component cellulose-based hydrogel and its utilization as adsorbent for aqueous contaminants.

The growing concern for the environment has resulted in renewed interest in bio-based resources. This study aims to produce a hydrogel adsorbent from cellulose and examine its adsorption performance. In pursuit of this goal, we report a simple one-pot synthesis of cellulose acetate sulfate (CAS), followed by the formation of CAS hydrogels and their subsequent adsorption performances. The CAS includes both hydrophilic and hydrophobic functional groups, enable the formation of a single-component hydrogel through intermolecular interactions in deionized water. The thermal reversibility of CAS hydrogels makes them easily processable into various shapes. The durability of the CAS hydrogel adsorbents can be improved by introducing divalent cations (e.g., Ca2+), which create ionically crosslinked hydrogels. The ionically a crosslinked CAS hydrogel adsorbent exhibits a maximum adsorption capacity of 245 mg/g for methylene blue (MB) at 23 °C and a pH of 7. The adsorption behavior of MB on the CAS hydrogel follows both the pseudo-second-order model and the Langmuir adsorption isotherm model. Furthermore, the CAS hydrogel adsorbent maintains a 70 % removal ratio after five cycles. The simplicity of synthesis and hydrogel formation opens up new possibilities for producing and utilizing cellulose-based hydrogels as adsorbents for aqueous contaminants.

Bicomponent lignocellulose thin films to study the role of surface lignin in cellulolytic reactions.

Ultrathin bicomponent films of cellulose and lignin derivatives were deposited on silica supports by spin coating, and after conversion into the respective polymer precursor, they were used as a model system to investigate interfacial phenomena relevant to lignocellulose biocatalysis. Film morphology, surface chemical composition, and wettability were determined by atomic force microscopy, X-ray photoelectron spectroscopy, and water contact angle, respectively. Phase separation of cellulose and lignin produced structures that resembled the cell wall of fibers and were used to monitor enzyme binding and cellulolytic reactions via quartz crystal microgravimetry. The rate and extent of hydrolysis was quantified by using kinetic models that indicated the role of the surface lignin domains in enzyme inhibition. Hydrophobic interactions between cellulases and the substrates and their critical role on irreversible adsorption were elucidated by using acetylated lignin films with different degrees of substitution. Overall, it is concluded that sensors based on the proposed ultrathin films of lignocellulose can facilitate a better understanding of the complex events that occur during bioconversion of cellulosic biomass.

At-Line Sampling and Characterization of Pyrolytic Vapors from Biomass Feedstock Blends Using SPME-GC/MS-PCA: Influence of Char on Fast Pyrolysis.

Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) analysis was used for the at-line sampling of pyrolytic vapors produced during the fast pyrolysis of biomass. The pure and binary blends of switchgrass (SWG) and pine harvest residues (PT6) were used as biomass feedstocks. Sequential SPME sampling allowed for monitoring of changes in the pyrolysis vapors as char accumulated in the fluid bed. The relative concentration and composition of the pyrolysis vapors desorbed from the SPME fibers were investigated using GC-MS, and the resulting chromatograms were analyzed using principal component analysis (PCA) to compare the composition of the pyrolysis vapors over the course of the pyrolysis run. The chemical compositions of both carbohydrate and lignin fragments varied as the char builds up in the reactor bed. Fragments derived from cellulose and hemicelluloses included anhydrosugars, furans, and light-oxygenated compounds. Lignin fragments included methoxyphenols, phenolic ketones, aldehydes, and low-molecular-weight aromatics. The composition of the carbohydrate fragments changed more than those of the lignin fragments as the char built up in the fluid bed. This combination of SPME-GC/MS-PCA was a novel, easy, and effective method for measuring the composition and changes in the composition of pyrolysis vapors during the fast pyrolysis process. This work also highlighted the effect of char build-up on the composition of the overall pyrolysis vapors.

Design strategies, properties and applications of cellulose nanomaterials-enhanced products with residual, technical or nanoscale lignin-A review.

With the increasing demand for greener alternatives to fossil-derived products, research on cellulose nanomaterials (CNMs) has rapidly expanded. The combination of nanoscale properties and sustainable attributes makes CNMs an asset in the quest for a sustainable society. However, challenges such as the hydrophilic nature of CNMs, their low compatibility with non-polar matrices and modest thermal stability, slow the development of end-uses. Combination of CNMs with amphiphilic lignin can improve the thermal stability, enhance the compatibility with non-polar matrices and, additionally, endow CNMs with new functionalities e.g., UV shielding or antioxidative properties. This article comprehensively reviews the different design strategies and their influence on properties and applications of CNMs containing lignin in various forms; either as residual lignin, added technical lignin, or nanoscale particles. The review focuses especially on the synergy created between CNMs and lignin, paving the way for new production routes and use of CNM/lignin materials in high-performance applications.

Techno-economic analysis of producing xylo-oligosaccharides and cellulose microfibers from lignocellulosic biomass.

This study assesses the economic performance of a biorefinery producing xylo-oligosaccharides (XOS) from miscanthus by autohydrolysis and purification based on a rigorous model developed in ASPEN Plus. Varied biorefinery capacities (50-250 oven dry metric ton (ODMT)/day) and three XOS content levels (80%, 90%, 95%) are analyzed. The XOS minimum selling price (XOS MSP) is varied between $3,430-$7,500, $4,030-$8,970, and $4,840-$10,640 per metric ton (MT) for 80%, 90%, and 95% content, respectively. The results show that increasing biorefinery capacity can significantly reduce the XOS MSP and higher purity leads to higher XOS MSP due to less yield, and higher capital and operating costs. This study also explores another system configuration to produce high-value byproducts, cellulose microfiber, by utilizing the cellulose to produce microfiber instead of combusting for energy recovery. The XOS MSP of cellulose microfiber case is $2,460-$7,040/MT and thus exhibits potential economic benefits over the other cases.

Dynamic life-cycle carbon analysis for fast pyrolysis biofuel produced from pine residues: implications of carbon temporal effects.

BACKGROUND: Woody biomass has been considered as a promising feedstock for biofuel production via thermochemical conversion technologies such as fast pyrolysis. Extensive Life Cycle Assessment studies have been completed to evaluate the carbon intensity of woody biomass-derived biofuels via fast pyrolysis. However, most studies assumed that woody biomass such as forest residues is a carbon-neutral feedstock like annual crops, despite a distinctive timeframe it takes to grow woody biomass. Besides, few studies have investigated the impacts of forest dynamics and the temporal effects of carbon on the overall carbon intensity of woody-derived biofuels. This study addressed such gaps by developing a life-cycle carbon analysis framework integrating dynamic modeling for forest and biorefinery systems with a time-based discounted Global Warming Potential (GWP) method developed in this work. The framework analyzed dynamic carbon and energy flows of a supply chain for biofuel production from pine residues via fast pyrolysis. RESULTS: The mean carbon intensity of biofuel given by Monte Carlo simulation across three pine growth cases ranges from 40.8-41.2 g CO2e MJ-1 (static method) to 51.0-65.2 g CO2e MJ-1 (using the time-based discounted GWP method) when combusting biochar for energy recovery. If biochar is utilized as soil amendment, the carbon intensity reduces to 19.0-19.7 g CO2e MJ-1 (static method) and 29.6-43.4 g CO2e MJ-1 in the time-based method. Forest growth and yields (controlled by forest management strategies) show more significant impacts on biofuel carbon intensity when the temporal effect of carbon is taken into consideration. Variation in forest operations and management (e.g., energy consumption of thinning and harvesting), on the other hand, has little impact on the biofuel carbon intensity. CONCLUSIONS: The carbon temporal effect, particularly the time lag of carbon sequestration during pine growth, has direct impacts on the carbon intensity of biofuels produced from pine residues from a stand-level pine growth and management point of view. The carbon implications are also significantly impacted by the assumptions of biochar end-of-life cases and forest management strategies.

Development of Langmuir-Schaeffer cellulose nanocrystal monolayers and their interfacial behaviors.

Model cellulose surfaces based on cellulose nanocrystals (CNs) were prepared by the Langmuir-Schaeffer technique. Cellulose nanocrystals were obtained by acid hydrolysis of different natural fibers, producing rodlike nanoparticles with differences in charge density, aspect ratio, and crystallinity. Dioctadecyldimethylammonium bromide (DODA-Br) cationic surfactant was used to create CN-DODA complexes that allowed transfer of the CNs from the air/liquid interface in an aqueous suspension to hydrophobic solid substrates. Langmuir-Schaeffer horizontal deposition at various surface pressures was employed to carry out such particle transfer that resulted in CN monolayers coating the substrate. The morphology and chemical composition of the CN films were characterized by using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Also, their swelling behavior and stability after treatment with aqueous and alkaline solutions were studied using quartz crystal microgravimetry (QCM). Overall, it is concluded that the Langmuir-Schaeffer method can be used to produce single coating layers of CNs that were shown to be smooth, stable, and strongly attached to the solid support. The packing density of the films was controlled by selecting the right combination of surface pressure during transfer to the solid substrate and the amount of CNs available relative to the cationic charges at the interface.

A cytoplasmic region determines single-channel conductance in 5-HT3 receptors.

5-hydroxytryptamine type 3 (5-HT3) receptors are cation-selective transmitter-gated ion channels of the Cys-loop superfamily. The single-channel conductance of human recombinant 5-HT3 receptors assembled as homomers of 5-HT3A subunits, or heteromers of 5-HT3A and 5-HT3B subunits, are markedly different, being 0.4 pS (refs 6, 9) and 16 pS (ref. 7), respectively. Paradoxically, the channel-lining M2 domain of the 5-HT3A subunit would be predicted to promote cation conduction, whereas that of the 5-HT3B subunit would not. Here we describe a determinant of single-channel conductance that can explain these observations. By constructing chimaeric 5-HT3A and 5-HT3B subunits we identified a region (the 'HA-stretch') within the large cytoplasmic loop of the receptor that markedly influences channel conductance. Replacement of three arginine residues unique to the HA-stretch of the 5-HT3A subunit by their 5-HT3B subunit counterparts increased single-channel conductance 28-fold. Significantly, ultrastructural studies of the Torpedo nicotinic acetylcholine receptor indicate that the key residues might frame narrow openings that contribute to the permeation pathway. Our findings solve the conundrum of the anomalously low conductance of homomeric 5-HT3A receptors and indicate an important function for the HA-stretch in Cys-loop transmitter-gated ion channels.

Biomimetic oxidative treatment of spruce wood studied by pyrolysis-molecular beam mass spectrometry coupled with multivariate analysis and 13C-labeled tetramethylammonium hydroxide thermochemolysis: implications for fungal degradation of wood.

In this work, pyrolysis-molecular beam mass spectrometry analysis coupled with principal components analysis and (13)C-labeled tetramethylammonium hydroxide thermochemolysis were used to study lignin oxidation, depolymerization, and demethylation of spruce wood treated by biomimetic oxidative systems. Neat Fenton and chelator-mediated Fenton reaction (CMFR) systems as well as cellulosic enzyme treatments were used to mimic the nonenzymatic process involved in wood brown-rot biodegradation. The results suggest that compared with enzymatic processes, Fenton-based treatment more readily opens the structure of the lignocellulosic matrix, freeing cellulose fibrils from the matrix. The results demonstrate that, under the current treatment conditions, Fenton and CMFR treatment cause limited demethoxylation of lignin in the insoluble wood residue. However, analysis of a water-extractable fraction revealed considerable soluble lignin residue structures that had undergone side chain oxidation as well as demethoxylation upon CMFR treatment. This research has implications for our understanding of nonenzymatic degradation of wood and the diffusion of CMFR agents in the wood cell wall during fungal degradation processes.

Long-Tailed Macaques (Macaca fascicularis) in Urban Landscapes: Gastrointestinal Parasitism and Barriers for Healthy Coexistence in Northeast Thailand.

Gastrointestinal parasites have diverse life cycles that can involve people, animals, and the environment (e.g., water and soil), demonstrating the utility of One Health frameworks in characterizing infection risk. Kosumpee Forest Park (Thailand) is home to a dense population of long-tailed macaques (Macaca fascicularis) that frequently interact with tourists and local residents. Our study investigated the presence of zoonotic parasites, and barriers to healthy coexistence by conducting stool analysis on macaques (N = 102) and people (N = 115), and by examining risk factors for infection with a household questionnaire (N = 95). Overall, 44% of macaques and 12% of people were infected with one or more gastrointestinal helminths, including Strongyloides spp., Ascaris spp., and Trichuris sp. An adults-only generalized linear mixed model identified three factors significantly associated with human infection: household size, occupational exposure, and contact with macaque feces at home. Participants identified both advantages and disadvantages to living in close contact with macaques, suggesting that interventions to improve human and animal health in Kosumpee Forest Park would be welcome.

Structure and properties of [(4,6-tBu2C6H2O)2Se]2An(THF)2, An = U, Np, and their reaction with p-benzoquinone.

The synthesis and characterization of U(iv) and Np(iv) selenium bis(phenolate) complexes are reported. The reaction of two equivalents of the U(iv) complex with p-benzoquinone results in the formation of a U(v)-U(v) species with a bridging reduced quinone. This represents a rare example of high-valent uranium chemistry as well as a rare example of a neptunium aryloxide complex.

Antagonism of neurosteroid modulation of native gamma-aminobutyric acid receptors by (3alpha,5alpha)-17-phenylandrost-16-en-3-ol.

Endogenous pregnane neurosteroids are allosteric modulators at gamma-aminobutyric acid type-A (GABAA) receptors at nanomolar concentrations. There is direct evidence for multiple distinct neurosteroid binding sites on GABAA receptors, dependent upon subunit composition and stoichiometry. This view is supported by the biphasic kinetics of various neuroactive steroids, enantioselectivity of some neurosteroids, selective mutation studies of recombinantly expressed receptors and the selectivity of the neurosteroid antagonist (3alpha,5alpha)-17-phenylandrost-16-en-3-ol (17PA) on 5alpha-pregnane steroid effects on recombinant GABAA receptors expressed in Xenopus oocytes and native receptors in dissociated neurons. However, it is unclear whether this antagonist action is present in a mature mammalian system. The present study evaluated the antagonist activity of 17PA on neurosteroid agonists both in vivo and in vitro by examining the effects of 17PA on 5alpha-pregnane-induced sedation in rats, native mature GABAA receptor ion channels utilizing the chloride flux assay and further studies in recombinant alpha1beta2gamma2 receptors. The data show that 17PA preferentially inhibits 3alpha,5alpha-THP vs. alphaxalone in vivo, preferentially inhibits 3alpha,5alpha-THDOC vs. alphaxalone potentiation of GABA-mediated Cl- uptake in adult cerebral cortical synaptoneurosomes, but shows no specificity for 3alpha,5alpha-THDOC vs. alphaxalone in recombinant alpha1beta2gamma2 receptors. These data provide further evidence of the specificity of 17PA and the heterogeneity of neurosteroid recognition sites on GABAA receptors in the CNS.

Steam torrefaction of Eucalyptus globulus for producing black pellets: A pilot-scale experience.

Steam torrefaction of Eucalyptus globulus was performed at temperatures between 245°C and 265°C in a 100kg/h pilot plant. Torrefied biomass was then pelletized in a 300kg/h unit and the pellets were subject to durability, density and combustion tests. The structural changes measured with FTIR were studied along with the combustion behavior of the materials. Compositional analysis showed that increasing the torrefaction temperature reduced both hemicellulose fraction and overall mass yield (MY). Furthermore, there was a linear relationship between the energy yield (EY) and mass yield (EY=[1.04-0.9(1-MY)]) for these samples. The ignition and comprehensive indexes confirmed that the stability of the torrefied biomass in a combustion environment was higher than for untreated biomass. Finally, pellets showed high durability (98%), and had an energy density (13-14GJ/m3), which is comparable to low-rank coals.

Detection of systemic amyloidosis in the pig-tailed macaque (Macaca nemestrina).

Secondary amyloidosis is a progressive systemic disease for which there is no reliable diagnostic assay, preventive measure, or treatment. In an attempt to elucidate an antemortem diagnosis, 30 female pig-tailed macaques (Macaca nemestrina) at the Washington National Primate Research Center were surveyed for amyloidosis. Amyloid was demonstrated histologically in 47% (14 of 30) of the animals. The distribution and severity of amyloid deposition was variable. Affected animals had a mean age (+/-1 standard deviation) of 13.2 +/- 4.9 y, which was significantly greater than the mean age of unaffected animals (9.3 +/- 4.1) y. Twelve tests were evaluated for detection of amyloidosis; the diagnostic value of each was determined through comparison of histologically positive and histologically negative animals. Diagnostic tests evaluated were endoscopic examination and biopsy of the stomach and colon, abdominal ultrasonography, hepatic radiology, serum amyloid A (SAA), endothelin 1, alpha-fetal protein, aspartate aminotransferase (AST), alanine aminotransferase, gamma-glutamyltransferase (GGT), alkaline phosphatase, cholesterol, blood urea nitrogen, total bilirubin, C-reactive proteins, and erythrocyte sedimentation rate. Amyloidotic animals demonstrated a distinctive serologic profile: elevated SAA, GGT, and AST in combination with decreased total protein and albumin. Radiology demonstrated hepatomegaly in animals with hepatic amyloid deposition. In the absence of known infection or trauma, an amyloidotic serologic profile and radiologic hepatomegaly are consistent with systemic amyloidosis in M. nemestrina.

Comparison of commercially available and novel West Nile virus immunoassays for detection of seroconversion in pig-tailed macaques (Macaca nemestrina).

We report the assessment and validation of an NS1 epitope-blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to West Nile virus (WNV) in macaques. Sera from naturally infected Macaca nemestrina were tested by ELISA and plaque reduction neutralization test (PRNT). Results were correlated with hemagglutination inhibition (HAI) data. Our results demonstrate that the blocking ELISA rapidly and specifically detects WNV infection in M. nemestrina. In addition, the diagnostic value of 7 commercially available immunoassays (PanBio immunoglobulin [Ig] M ELISA, PanBio IgG ELISA, PanBio immunofluorescence assay (IFA), InBios IgG ELISA, InBios IgM ELISA, Focus Diagnostics IgG ELISA, and Focus Diagnostics IgM ELISA) in M. nemestrina was evaluated and compared with that of the epitope-blocking ELISA. The PanBio IgG ELISA was found to effectively diagnose WNV exposure in M. nemestrina. Further, PanBio IFA slides are fast and reliable screening tools for diagnosing flaviviral exposure in M. nemestrina.