Fiber Wall Research Articles

Electromembrane extraction of tramadol from exhaled breath condensate and its liquid chromatographic analysis

Tramadol has extracted from the exhaled breath condensate (EBC) samples through the supported liquid membrane consisting of 2-nitrophenyl octyl ether impregnated in the hollow fiber wall, and the lumen of the hollow fiber was filled with 20 μL of an acceptor phase. Under the optimum conditions of the electromembrane extraction, i.e. the stirring speed of 750 rpm, extraction time of 20 min, acceptor pH at 1.0, donor phase pH at 6.0, and an applied voltage of 170 V across the supported liquid membrane, a preconcentration factor of 128-fold with a extraction recovery of 64% was achieved. Acceptable linearity was obtained in the tramadol concentration range of 5–1000 ng mL−1 (R2 = 0.9999) with a limit of detection of 1.5 ng mL−1 and a limit of quantitation of 5 ng mL−1. The relative standard deviations for the intra-day and inter-day replications were obtained between 0.4% and 2.5%. The validated technique was successfully used to determine tramadol in real EBC samples.

Lignin p-Hydroxybenzoylation Is Negatively Correlated With Syringyl Units in Poplar.

The lignin found in the cell walls of poplar fibres is decorated with ester-linked p-hydroxybenzoate moieties that originate from the participation of acylated monolignols in lignin polymerisation. Although little is known about the biological implications of these cell-wall constituents, it has historically been postulated that acylated monolignols might promote lignification in syringyl lignin-rich species such as poplar. However, cell-wall-bound p-hydroxybenzoate groups were negatively correlated with syringyl units in a collection of 316 unrelated genotypes of black cottonwood (Populus trichocarpa). Based upon this observation, several alternative hypotheses on the occurrence of lignin acylation are presented.

Functional trade-offs in volume allocation to xylem cell types in 75 species from the Brazilian savanna Cerrado.

Xylem is a crucial tissue for plant survival, performing the functions of water transport, mechanical support and storage. Functional trade-offs are a result of the different assemblages of xylem cell types within a certain wood volume. We assessed how the volume allocated to different xylem cell types can be associated with wood functional trade-offs (hydraulics, mechanical and storage) in species from the Cerrado, the Brazilian savanna. We also assessed the xylem anatomical characters linked to wood density across species. We analysed cross-sections of branches collected from 75 woody species belonging to 42 angiosperm families from the Cerrado. We estimated the wood volume fraction allocated to different cell types and performed measurements of vessel diameter and wood density. The largest volume of wood is allocated to fibres (0.47), followed by parenchyma (0.33) and vessels (0.20). Wood density is positively correlated to cell wall (fibre and vessel wall), and negatively to the fractions of fibre lumen and gelatinous fibres. We observed a trade-off between hydraulics (vessel diameter) and mechanics (cell wall fraction), and between mechanics and storage (parenchyma fraction). The expected positive functional relationships between hydraulics (vessel diameter) and water and carbohydrate storage (parenchyma and fibre lumen fractions) were not detected, though larger vessels are linked to a larger wood volume allocated to gelatinous fibres. Woody species from the Cerrado show evidence of functional trade-offs between water transport, mechanical support and storage. Gelatinous fibres might be potentially linked to water storage and release by their positive relationship to increased vessel diameter, thus replacing the functional role of parenchyma and fibre lumen cells. Species can profit from the increased mechanical strength under tension provided by the presence of gelatinous fibres, avoiding expensive investments in high wood density.

Experimental Study of Intra-Ring Anatomical Variation in Populus alba L. with Respect to Changes in Temperature and Day-Length Conditions

There are various studies on annual ring structural variations in plants grown in the field under varying meteorological statistics. However, related experimental approach is limited, hitherto. In this study, complete artificial conditions with growth chambers were adopted to evaluate the influence of day length and temperature on intra-ring structure formation. The basic artificial growing conditions have been previously reported as “shortened annual cycle system”, which consisted of the following three stages mimicking seasons approximately: Stage 1, spring/summer; Stage 2, autumn; and Stage 3, winter. This system shortens an annual cycle of Populus alba to 5 months. In this study, Stage 2 was modified in two ways: one was a condition in which the temperature was fixed and the day length was gradually shortened, and the other was a condition with a fixed day length and gradually lowered temperature. In the former condition, the cell wall of fibers thickened from the middle of the ring, and the vessel diameter became smaller from the same position. The wood in the latter condition appeared more natural in terms of wall thickness and vessel shape; however, the thickness of the wall reduced in the starting position of Stage 2. It may have been caused by the shortage of material for cell production under a high temperature but a short day length.

Fiber quality and wood basic density of species of the Savannah for productive purposes

The objective of this study was to qualify the wood of the species Astronium fraxinifolium, Enterolobium gummiferum, Eriotheca pentaphylla, and Plathymenia reticulata of the Brazilian Cerrado for forestry productive purposes based on the classification of their wood basic density and fiber quality indices. Discs were removed at a height of 1.3 m from the ground, and opposing wedges were obtained. The analyzed parameters were: wood basic density, fiber dimension, and fiber quality indices. The wood basic density was negatively correlated with fiber length and thickness. E. pentaphylla presented low basic density, long fiber length, and greater fiber wall thickness. On the other hand, A. fraxinifolium, E. gummiferum, and P. reticulata woods presented medium/high basic density, short fiber length, and quality indices that foster them for energy purposes, paper production, and use in floors and civil construction.

Review: Tertiary cell wall of plant fibers as a source of inspiration in material design

The review summarizes the plant lifehacks on material design on the example of the impressive cellulose-enriched cell wall deposited by fibers of many plants. This specific cell wall type is called tertiary since it is deposited after the secondary cell wall and is very distinct in the machinery of formation and function. The basic principles of tertiary cell wall performance include: 1) original composition (two major players – cellulose microfibrils and the version of rhamnogalacturonan I that forms specific supramolecular structures); 2) original cell wall design with axial orientation of all cellulose microfibrils, pronounced lateral interactions between them and the presence of the entrapped rhamnogalacturonan I; 3) dynamic changes in cell wall supramolecular organization due to rhamnogalacturonan I modifications in muro in the course of fiber maturation; 4) the built-in sensors that trace the cell wall state; 5) incorporation of tertiary cell wall into the system with higher level of organization.

Wood Properties of 38-year-old Cariniana legalis (Mart.) Kuntze Based on Planting Spacing

This study aimed to analyze the properties of 38-year-old Cariniana legalis wood from trees planted with three spacings between trees: 3 × 2.5, 3 × 2, and 3 × 1.5 m. Five trees were collected from each tree spacing. Discs were collected from the trunk base of each tree and at 2.5 and 5.0 m. The vessel diameter was significantly wider for a spacing of 3 x 2.5 m compared to that of 3 x 1.5 m. Basic density, apparent density, volumetric shrinkage, and natural moisture content were influenced by longitudinal position. However, fiber length and fiber wall thickness showed no significant differences. Basic density and natural moisture content were inversely proportional. Our study shows that the anatomical features of C. legalis wood were more sensitive to variations in tree spacing than its physical properties.

6-Benzylaminopurine and kinetin modulations during in vitro propagation of Quercus robur (L.): an assessment of anatomical, biochemical, and physiological profiling of shoots

For many woody species, such as Quercus robur, cytokinins in the culture medium are required to maintain in vitro plant material. Among synthetic cytokinins, 6-benzylaminopurine (BAP) and kinetin (KIN) are the most frequently used. In addition to inducing shoots, cytokinins can cause morphophysiological disorders. Therefore, we aimed to investigate the anatomical, biochemical, and physiological alterations and profiles of Q. robur shoots exposed to two cytokinins, applied alone and in combination. Shoots previously established in vitro were transferred to WPM culture media supplemented with BAP at concentrations of 0, 1.25, and 3.50 µM combined with KIN at concentrations of 0, 0.62, and 1.25 µM totaling 9 treatments. Anatomical, physiological, and biochemical analyses were performed after 40 days of culture. BAP induced the formation of new buds with anatomically underdeveloped leaves; induced shoot-tip necrosis, which is considered a response to the inefficient transport of water and nutrients; reduced the thickness of the cell walls of phloem fibers; and decreased the content of phenolic compounds and photosynthetic pigments. These responses were less pronounced with co-exposure to KIN. In contrast, KIN alone stimulated a larger area of secondary xylem and more lignified cell walls. BAP can induce shoots with underdeveloped anatomical and biochemical characteristics. Shoots that grew with KIN alone had stem and leaf anatomical characteristics, indicating greater commitment to cellular differentiation than proliferation. When both cytokinins are combined, KIN can partially mitigate the deleterious effects of BAP on in vitro growth. BAP generated shoots with underdeveloped anatomical and biochemical characteristics. KIN can partially mitigate the deleterious effects of BAP on in vitro growth.

Flexible and digestible wood caused by viral-induced alteration of cell wall composition

Woody plant material represents a vast renewable resource that has the potential to produce biofuels and other bio-based products with favorable net CO2 emissions.1,2 Its potential has been demonstrated in a recent study that generated novel structural materials from flexible moldable wood.3 Apple rubbery wood (ARW) disease is the result of a viral infection that causes woody stems to exhibit increased flexibility.4 Although ARW disease is associated with the presence of an RNA virus5 known as apple rubbery wood virus (ARWV), how the unique symptoms develop is unknown. We demonstrate that the symptoms of ARWV infections arise from reduced lignification within the secondary cell wall of xylem fibers and result in increased wood digestibility. In contrast, the mid-lamellae region and xylem ray cells are largely unaffected by the infection. Gene expression and proteomic data from symptomatic xylem clearly show the downregulation of phenylalanine ammonia lyase (PAL), the enzyme catalyzing the first committed step in the phenylpropanoid pathway leading to lignin biosynthesis. A large increase in soluble phenolics in symptomatic xylem, including the lignin precursor phenylalanine, is also consistent with PAL downregulation. ARWV infection results in the accumulation of many host-derived virus-activated small interfering RNAs (vasiRNAs). PAL-derived vasiRNAs are among the most abundant vasiRNAs in symptomatic xylem and are likely the cause of reduced PAL activity. Apparently, the mechanism used by the virus to alter lignin exhibits similarities to the RNAi strategy used to alter lignin in genetically modified trees to generate comparable improvements in wood properties.6-8.

DEVELOPMENT OF WOOD GRINDING 4. EVALUATION OF THE THEORETICAL GRINDING MODEL

"Spruce wood was ground under certain fixed conditions to achieve data for interpretation of the grinding mechanism. For this purpose, wood moisture content, wood feeding rate and grindstone peripheral speed were given five, three and two different levels, respectively. The data obtained by application of a laboratory grinder were accordingly most reliable, because the grinder was run under well controlled conditions, and the wood samples represented one and the same wood quality, but at five moisture content levels. The grinding zone temperature was measured at the outlet from the grinding zone, and accordingly it would indicate the average grinding zone temperature. The grinding model suggests that the energy specific fibre production ( w/Pt) evaluated at various power friction levels (Pc/Pt) would help understanding the wood grinding mechanism. The energy specific fibre production showed significant dispersion, when evaluated as a function of the power friction. However, detailed analysis of the data revealed that there could be two linears, one representing moisture saturated wood, and one representing fresh wood that also contains free water in the lumina. Surprisingly, this linear also included data representing air-dry wood. Increasing wood moisture ratio from 0.2 kg to 1.4 kg per kg o.d. wood decreased the average grinding zone temperature significantly from about 98° to 88 °C. Further, there was roughly a difference of 8–12° C in grinding zone temperature due to the wood moisture, when evaluated as a function of the force friction coefficient (Ft/Fc). The two highest moisture ratios resulted in a low-level linear, as the other moisture ratios produced a high-level linear. The wood moisture content seems to affect the grinding process in different ways due to the moisture content level. Since moisture is absorbed in the fibre wall material and evidently linked to various lignin and cellulose components by hydrogen bonds, it will affect the grinding in a certain mode. However, the air-dry wood sample seemed to act as the fresh wood samples, which cannot be explained properly unless also considering fibrillation and fibre properties."

MiR395c Regulates Secondary Xylem Development Through Sulfate Metabolism in Poplar.

Secondary xylem development requires the coordination of multiple regulatory factors, including plant hormones, transcription factors, and microRNAs (miRNAs). MiR395 is an important regulator involved in sulfate metabolism, but its function in plant development is unclear. This study investigated the functions of miR395c in the secondary xylem development in Populus alba × P. glandulosa. MiR395c was highly expressed in the shoot apex and secondary xylem. The overexpression of miR395c resulted in an increase in both secondary xylem width and vessel dimension, as well as a decrease in the thickness of the secondary cell wall of the xylem fiber. Further analysis showed that miR395c inhibited biosynthesis of sulfate metabolic products by targeting ATPS genes, which led to the reduction of Abscisic acid (ABA) synthesis and down-regulation of MYB46 expression. Our results indicate that miR395c regulates the secondary xylem development process via sulfate metabolism in Populus.

Anatomy of the left atrial appendage for the interventional cardiologist.

Exact knowledge of the anatomy of the left atrial appendage (LAA) is crucial for LAA isolation by catheter ablation and for interventional LAA occlusion in patients with atrial fibrillation. This review outlines the current anatomical understanding of LAA morphology from ostium to distal lobes, myocardial fiber orientation and wall structure, and adjacent structures such as the left upper pulmonary vein with the Coumadin ridge, the circumflex artery with its side branches, the aortic root, pulmonary artery, and the pericardial space. Insight into these details will facilitate these interventions and reduce the risk of complications.

Micro- and Nanofibrillated Cellulose from Annual Plant-Sourced Fibers: Comparison between Enzymatic Hydrolysis and Mechanical Refining.

The current trends in micro-/nanofibers offer a new and unmissable chance for the recovery of cellulose from non-woody crops. This work assesses a technically feasible approach for the production of micro- and nanofibrillated cellulose (MNFC) from jute, sisal and hemp, involving refining and enzymatic hydrolysis as pretreatments. Regarding the latter, only slight enhancements of nanofibrillation, transparency and specific surface area were recorded when increasing the dose of endoglucanases from 80 to 240 mg/kg. This supports the idea that highly ordered cellulose structures near the fiber wall are resistant to hydrolysis and hinder the diffusion of glucanases. Mechanical MNFC displayed the highest aspect ratio, up to 228 for hemp. Increasing the number of homogenization cycles increased the apparent viscosity in most cases, up to 0.14 Pa·s at 100 s−1 (1 wt.% consistency). A shear-thinning behavior, more marked for MNFC from jute and sisal, was evidenced in all cases. We conclude that, since both the raw material and the pretreatment play a major role, the unique characteristics of non-woody MNFC, either mechanical or enzymatically pretreated (low dose), make it worth considering for large-scale processes.

Disk-shaped cellulose fibers from red algae, Eucheuma cottonii and its use for high oxygen barrier

We could prepare disk-shaped fibers without particular mechanical treatments from Eucheuma cottonii, the commonly used red algae for obtaining carrageenan. After carrageenan extraction from cottonii, the residues were bleached using chlorine dioxide and hydrogen peroxide. The morphology of the bleached fiber was disk-shaped one with a very thin fiber wall thickness of less than 100 nm and a diameter of approximately 100 μm. The sugar analysis and X-ray diffraction of the bleached fibers showed that they consisted of mostly glucose and had the same pattern as cellulose I with more than 50% crystalline structure, respectively. Compared to one-dimensional cellulose micro- or nanofibrils, which exhibits slow drainage and possess intolerably high drying energy, these two-dimensional disk-shaped fibers, when formed a layer in water medium, exhibit fast drainage and low drying energy. The formed sheet resulted in excellent transparency and high oxygen barrier property. Therefore, by using these disk-shaped, thin fibers from cottonii, we expect that the biodegradable and transparent oxygen barrier layer can be produced at a paper machine, which is, if possible, extremely difficult in the case of cellulose micro- or nanofibrils due to their slow drainage and high drying energy.

Designing with Circular Arc Toolpaths to Increase the Complexity of Melt Electrowriting

AbstractMelt electrowriting (MEW) is an additive manufacturing technology that fabricates high‐resolution objects. Printing curved and complex patterns, however, requires additional attention and planning to achieve accurate fiber placement. In this context, the jet speed, as measured by the critical translation speed (CTS), is found to be an essential factor for accurately direct‐writing complex nonlinear patterns. When the jet and the translation speed match, the vertical jet better approximates the tool path when the printing is nonlinear. As demonstrated here, the entire printed structure gradually deforms when the jet lag increases. For the first time with MEW, circular arc toolpaths are focused on to expand the design complexity, and there is evidence that the resolution is further improved by printing slightly under the CTS. When using such circular arc toolpaths, inwards tilting of the fiber walls can be observed and can be corrected with microscale layer shifting, shown with scaffolds based on knitting‐type designs. The combination of printing at the CTS with circular arcs increases the manufacturing complexity of curved patterns and has implications for the design and utility of MEW.

Extraction and Characterization of Natural Cellulosic Fiber from Taraxacum Sect. Ruderalia

ABSTRACT The aim is to explore the utilization of cellulosic fibers extracted from the Taraxacum Sect. Ruderalia, which is also known as dandelion, introduces a potential reinforcement for the green composite industry. This research is focused on the analysis of chemical, physical, thermal, and morphological properties of the Taraxacum Sect. Ruderalia fibers. Its lightweight (1.397 g/cm3) with the presence of an acceptable cellulose ratio (52.7%) and high crystallinity (69.59%) provide comparable tensile strength (57.36 MPa) and Young’s modulus (2.96 GPa) for Taraxacum Sect. Ruderalia fibers. The fibers are experimentally thermal resistant to 272°C according to TGA that may be profitable in extrusion processes in polymeric composite manufacturing. The average fiber diameter and wall thickness were optically 233 µm and 1.5 µm, respectively. Taraxacum Sect. Ruderalia fibers have a rough surface character with some irregularities such as porosities, particles, indentations, protrusions, and also the microfibrillar structure which can support mechanical interlocking with polymer in a composite system. With all these encouraging properties, Taraxacum Sect. Ruderalia fibers can be good alternative reinforcement for common cellulosic bast fibers in the development of ecologically friendly and sustainable polymeric-based materials.

Resistance factors of pecky rice incidence caused by the rice stink bugs (Leptocorisa chinensis, Nezara viridula) in rice line CRR-99-95W

ABSTRACT Pecky rice incidence caused by rice stink bugs greatly decreases the quality of rice grain and has come a big problem not only in Japan but also many other rice producing countries recently. In this study, antixenosis and tolerance were examined as the factors of resistance to rice stink bugs attack of rice line CRR-99-95 W. Two experiments were conducted to determine a possibility of antixenosis involvement as a factor of the resistance in CRR-99-95 W. The results showed no correlation between the number of Leptocorisa chinensis parasites and pecky rice incidence. Furthermore, no significant difference was found between the sucking frequency of Nezara viridula on mature husks of CRR-99-95 W and that on the check genotypes. These results suggest that CRR-99-95 W does not exhibit antixenosis effect against rice stink bugs. Then, to examine the tolerance factor involved in the resistance mechanism, the husks structures were analyzed. The results showed that the packing ratio of cell wall of the sclerenchyma fibers in the palea tended to be higher in CRR-99-95-W compared to the check genotype. In addition, the width of the hook openness of the palea of CRR-99-95 W was narrower than that of the check genotype. Such morphological characteristic of CRR-99-95 W may play an important role in its resistance against stink bug attack.

Preconcentration and determination of five antidepressants from human milk and urine samples by stir bar filled magnetic ionic liquids using liquid-liquid-liquid microextraction-high-performance liquid chromatography.

A sensitive and straightforward liquid-liquid-liquid microextraction method was developed to preconcentrate and cleanup antidepressants, including mirtazapine, venlafaxine, escitalopram, fluoxetine, and fluvoxamine, from biological samples before analyzing with high-performance liquid chromatography. The essential novelty of this study is using magnetic ionic liquids as the extraction phase in the lumen of hollow fiber and preparing a liquid magnetic stir bar. In this method, polypropylene hollow fiber was utilized as the permeable membrane for the analyte extraction. Six magnetic ionic liquids consisting ofthe transition metal and rare earth compounds were synthesized and then hollow fiber lumen was injected as acceptor phase to extract the antidepressants. Besides, 3-pentanol as a water-immiscible solvent was impregnated in the hollow fiber wall pores. The effective factors in the method were optimized with the central composition design. The resultant calibration curves were linear over the concentration range of 0.8-400.0ng mL-1 (R2 ≥ 0.996). The method displayed the proper detection limit (0.11-0.24ng mL-1 ), the reasonable limit of quantification (≤0.79ng mL-1 ), wide linear ranges, high preconcentration factors (≥294.3), and suitable relative standard deviation (2.31-5.47%) for measuring antidepressant medications. Analysis of human milk and urine samples showed acceptable recoveries of 96.5-103.8% with excellent relative standard deviations lower than 5.95%.

Differences in wood anatomy and chemistry of a Eucalyptus urophylla clone explained by site climate conditions

Environmental conditions can change both the quantity and quality of wood formation. This study aimed to evaluate anatomical and chemical changes in the wood of a Eucalyptus urophylla S.T. Blake clone cultivated in four sites of wide climatic conditions in Brazil. Radial samples were used to evaluate xylem anatomy along the growth cycles. Samples with a quarter of a disk were used to perform chemical analyses of extractives, total lignin (LG), syringyl/guaiacyl (S/G), holocellulose, and elemental analysis of wood. The elements Na, K, Ca, Mg, P, Mn, Fe, Zn, Ni, Cu, Cr, Cd, F, and Cl were also quantified. Correlations using the mean values of the variables per site were higher than those using values per tree growth cycle (years). Mean annual air temperature showed the highest correlations with wood density (r = −0.89) and the anatomical characteristics (vessel area: r = −0.68; fiber wall thickness: r = −0.70; vessel frequency: r = 0.74; and fiber lumen diameter: r = 0.90). Only LG and S/G showed significant correlations with the meteorological variables, with drier sites presenting a higher S/G. The anatomical characteristics change with regionwide climate features, while wood chemical characteristics showed weaker relations with climatic variations.

Estimating cellulose microfibril orientation in the cell wall sublayers of bamboo through dimensional analysis of microfibril aggregates

The mechanical performance and dimensional stability of bamboo is highly dependent on the microfibril orientation in its cell wall sublayers. However, a comprehensive and quantitative description of this orientation at the sublayer scale of cell wall is very challenging to do. Here, we proposed a new approach to quantitatively estimate the cellulose microfibril orientation across the whole cell wall of both fibers and parenchyma cells in bamboo. This new approach is based on the geometrical correlation between the actual and apparent dimensions of cellulose microfibril aggregates, which are respectively determinedly with CP/MAS 13C NMR and high-resolution field emission scanning electron microscopy (FE-SEM). For comparison, the average microfibril angle (MFA) of both fibers and parenchyma cells were also measured using X-ray diffraction (XRD). It was concluded that the cellulose microfibrils in the broad sublayers of the bamboo fibers exhibited a relatively small MFA of about 10°, while those in the narrow sublayers were nearly oriented in the transverse with a MFA of about 80°. For parenchyma cells, the MFA of the broad and narrow sublayers were estimated to be 50–70° and 70–80°, respectively. Modified cell wall structural models for the two types of cells were then proposed.