Thin-walled Cells Research Articles

Using PacBio SMRT Sequencing Technology and Metabolomics to Explore the Microbiota-Metabolome Interaction Related to Silage Fermentation of Woody Plant

Silage fermentation is a dynamic process involving the succession of microbial communities and changes in metabolites. Fresh branched and leaves of paper mulberry were used to prepared silage. Crop by-products including corn bran, rice bran, and wheat bran were used as exogenous additives. Pacific Biosciences single-molecule real-time (SMRT) sequencing technology and metabolomics are used to explore the interaction mechanism of microbial structure and metabolites during woody silage fermentation and to verify the principle that exogenous additives can modulate silage fermentation. Under the dual stress of anaerobic and acidic environment of silage fermentation, the microbial community changed from Gram-negative to Gram-positive bacteria, and a large amount of lactic acid and volatile fatty acid were produced, which lowered the pH value and caused the rapid death of aerobic bacteria with thin cell walls. The exogenous additives of corn bran and wheat bran accelerated the dynamic succession of lactic acid bacteria as the dominant microbial community in silage fermentation, increased the metabolic pathways of lactic acid, unsaturated fatty acids, citric acid, L-malic acid and other flavoring agents, and inhibited the growth of Clostridium and Enterobacter, thereby improving the flavor and quality of the silage. However, because rice bran contained butyric acid spore bacteria, it can multiply in an anaerobic environment, led to butyric acid fermentation, and promoted protein degradation and ammonia nitrogen production, thereby reduced the fermentation quality of woody silage. The results showed that during the silage fermentation process, the microbial community and the metabolome can interact, and exogenous additives can affect the fermentation quality of silage. SMRT sequencing technology and untargeted metabolomics revealed the microbiota-metabolome interaction during silage fermentation. Changes in the structure of the microbial community can affect the metabolic pathways, and the final metabolites can inhibit the growth of microorganisms that are not conducive to silage fermentation. Exogenous carbohydrate additives can change the fermentation substrate and affect microbial community structure, thus modulate the silage fermentation.

Physical and microstructural quality of extruded snacks made from blends of barley and green lentil flours

AbstractBackground and objectivesMost puffed snacks in the market are made from refined cereal flours which allow greater expansion and better texture but are nutritionally inferior as they lack protein and dietary fiber. Whole barley and green lentil flours at several blending ratios were extruded as a function of temperature and moisture content to optimize the physical and microstructural quality of fiber and protein‐enriched snacks.FindingsHigh extrusion temperature significantly improved overall expansion and texture. The effects of feed moisture depended on the blending ratio, parallel with the total protein and dietary fiber content of extrudates. Barley:green lentil of 45:55 showed the highest extrudate expansion (~1.9 mm/mm on average) and lowest hardness (~29 N on average), followed by the blend 60:40. X‐ray microtomography showed that this blending ratio also produced a larger mean cell size (~1.6 mm), lower mean wall thickness (~0.3 mm), and higher overall connectivity between cells.ConclusionBarley and green lentil when blended at the ratios of 45:55 and 60:40, and extruded at higher temperature resulted in optimal extrudate physical and microstructural properties including higher expansion and crispness, thinner cell walls, reduced hardness, and crunchiness.Significance and noveltyBlending cereal and pulse flours in snack food applications will allow development of fiber and protein‐enriched options that are also texturally and structurally appealing.

3D Binder-free conjugated microporous polymer carbon Aerogels@MnO2 cathode for High-Performance aqueous zinc ion batteries

Binder-free MnO2-based cathodes are critical to the development of aqueous Zn//MnO2 batteries. Here, conjugated microporous polymer aerogels (CMPAs) with columnar, rod and linear shapes are successfully prepared through Sonogashira-Hagihara cross-coupling reaction. Using them as precursors, we obtain the integrated high-conductivity carbon-based aerogels (C-CMPAs) by pyrolysis. Secondly, MnO2 nanosheet arrays are uniformly grown on the surface of C-CMPAs nanotubes(C-CMPAs@MnO2) form a thin-walled cell configuration through a simple low temperature hydrothermal method. In this system, C-CMPAs serve as both current supporter and collector, while the cross-linked MnO2 flakes act as the active layer. This unique anisotropic structure not only greatly enlarges the contact area of electrode/electrolyte interfaces and supplies abundant electrochemically active sites, but shortens the Zn2+ ion insertion/extraction paths. Meanwhile, the high mechanical strength of core/shell structure between C-CMPAs and MnO2 renders long-term cycling life. Finally, binder-free C-CMPAs@MnO2-based aqueous zinc-ion batteries provide an unprecedented capacity of 670.7 mAh g−1 at 0.1 A g−1, good rate performance and excellent cycle stability (94.1% after 600 cycles). More importantly, the Zn//C-CMPAs@MnO2 aqueous battery provides high energy density of 536.6 Wh kg−1 at 80.3 W kg−1, superior to most similar reports, indicating the great potential of high-performance rechargeable batteries.

Tip growth defective1 interacts with cellulose synthase A3 to regulate cellulose biosynthesis in Arabidopsis.

AtTIP1 physically and genetically interacts with AtCESA3. AtCESA3 undergoes S-acylation, possibly mediated by AtTIP1, suggesting a specific role of AtTIP1 in cellulose biosynthesis and plant development. S-acylation is a reversible post-translational lipid modification of proteins catalyzed by protein S-acyl transferases (PATs). S-acylation is important for various biological molecular mechanisms including cellulose biosynthesis. Cellulose is synthesized by the cellulose synthase A (CESA) complexes (CSCs) at the plasma membrane. However, specific PAT involving in cellulose biosynthesis has not been identified and the precise mechanism by which PAT regulates the CESAs is largely unknown. Here, we report isolation of tip1-5, an allele of Tip Growth Defective1 (AtTIP1/AtPAT24) with a premature stop codon. tip1-5 genetically interacts with ixr1-2, a point mutant of AtCESA3 which encodes a catalytic subunit of CSC synthesizing primary wall cellulose. We show that AtTIP1 physically interacts with AtCESA3. AtCESA3 undergoes S-acylation, which is possibly mediated by AtTIP1, suggesting a functional relationship between AtTIP1 and AtCESA3. Moreover, the interfascicular fiber cells in the primary inflorescence stems of tip1-5 ixr1-2 double mutant contain thinner cell walls and significantly less crystalline cellulose compared to the single mutants. These results highlight the positive regulation of AtTIP1 in cellulose biosynthesis, and a specific role of AtPAT in plant development.

Antifungal activities of a natural trisaccharide ester against sour rot in mandarin fruit

Sour rot caused by Geotrichum citri-aurantii is one of the most important diseases leading to postharvest loss of Citrus reticulate. In this study, the antifungal activity of MTE-1, a natural trisaccharide ester from the cultures of Pezicula neosporulosa, against G. citri-aurantii was evaluated. MTE-1 treatment inhibited the mycelium growth of G. citri-aurantii. Paper-disc agar-diffusion experiment showed that the inhibitory effect of MTE-1 against G. citri-aurantii was almost comparable to that of the commercial fungicide albesilate. Moreover, application of MTE-1 efficiently reduced the incidence of sour rot of mandarin fruit inoculated with G. citri-aurantii. Ultrastructural observations showed that MTE-1 treatment resulted in thinning of cell wall in spores and reduction of cell content in mycelia of G. citri-aurantii. Furthermore, transcriptome analysis along with RT-qPCR validation was conducted to better understand the role of MTE-1 on G. citri-aurantii. Several important genes related to fungal pathogenicity and virulence, including CRZ1, PMA1, RME1, ALDH and Lip, showed decreasing expression levels after MTE-1 treatment, which might be responsible for its antimicrobial activity. Overall, application of MTE-1 is a promising method to control sour rot of harvested citrus fruit.

Bacillus-Based Products to Control Meloidogyne incognita Races 3 and 4 in Cotton and Compared Histopathology Using B. methylotrophicus

Cotton meloidoginosis caused by Meloidogyne incognita races 3 and 4 is an important disease and can cause intense damage. The objective of this work was to test the effectiveness of commercial Bacillus-based products in the control of M. incognita races 3 and 4 of cotton in a greenhouse. Plants with and without nematode inoculation were used and subsequently evaluated for 200 days after the application of treatments. The products with Bacillus subtilis, B. amyloliquefasciens and B. subtilis + B. lincheniformis showed the best results in terms of shoot fresh matter weight. In relation to shoot dry weight, treatments with B. methylotrophicus (87 g, with nematode) and B. subtilis (80 g, with nematode) were superior, with emphasis on B. methylotrophicus. In the evaluation of root fresh weight, only the treatment with B. methylotrophicus (148.8 g, with nematode) provided statistically higher weight than the control. In item dry weight of root without nematode and nematode reproduction factor, the treatment with B. methylotrophicus stood out from the other treatments, making this the selected product to conduct the subsequent tests. With the acid fuchsin staining method, it was possible to verify that there was reduction in the penetration of J2 in the first days for plants treated with the bacteria. Upon adoption of the toluidine blue staining method, it was possible to observe abnormalities in giant cells with formation of vacuoles, thinner cell wall and females with large vacuoles inside. Thus, there is evidence that the use of biological products can be effective in controlling M. incognita.

Genomic and Transcriptomic Analyses Reveal Pathways and Genes Associated With Brittle Stalk Phenotype in Maize.

The mechanical strength of the stalk affects the lodging resistance and digestibility of the stalk in maize. The molecular mechanisms regulating the brittleness of stalks in maize remain undefined. In this study, we constructed the maize brittle stalk mutant (bk5) by crossing the W22:Mu line with the Zheng 58 line. The brittle phenotype of the mutant bk5 existed in all of the plant organs after the five-leaf stage. Compared to wild-type (WT) plants, the sclerenchyma cells of bk5 stalks had a looser cell arrangement and thinner cell wall. Determination of cell wall composition showed that obvious differences in cellulose content, lignin content, starch content, and total soluble sugar were found between bk5 and WT stalks. Furthermore, we identified 226 differentially expressed genes (DEGs), with 164 genes significantly upregulated and 62 genes significantly downregulated in RNA-seq analysis. Some pathways related to cellulose and lignin synthesis, such as endocytosis and glycosylphosphatidylinositol (GPI)-anchored biosynthesis, were identified by the Kyoto Encyclopedia of Gene and Genomes (KEGG) and gene ontology (GO) analysis. In bulked-segregant sequence analysis (BSA-seq), we detected 2,931,692 high-quality Single Nucleotide Polymorphisms (SNPs) and identified five overlapped regions (11.2 Mb) containing 17 candidate genes with missense mutations or premature termination codons using the SNP-index methods. Some genes were involved in the cellulose synthesis-related genes such as ENTH/ANTH/VHS superfamily protein gene (endocytosis-related gene) and the lignin synthesis-related genes such as the cytochrome p450 gene. Some of these candidate genes identified from BSA-seq also existed with differential expression in RNA-seq analysis. These findings increase our understanding of the molecular mechanisms regulating the brittle stalk phenotype in maize.

Responses of Issatchenkia terricola WJL-G4 upon Citric Acid Stress.

This study aimed to elucidate the responses of a novel characterized Issatchenkia terricola WJL-G4 against citric acid stress by performing physiological analysis, morphology observation, and structural and membrane fatty acid composition analysis. The results showed that under citric acid stress, the cell vitality of I. terricola WJL-G4 was reduced. The cell morphology changed with the unclear, uncompleted and thinner cell wall, and degraded the cell structure. When the citric acid concentration was 20 g/L, I. terricola WJL-G4 could tolerate citric acid and maintain the cell structure by increasing the intracellular pH, superoxide dismutase activity, and contents of unsaturated fatty acids. As the citric acid concentration was ≥80 g/L, the stress has exceeded the cellular anti-stress ability, causing substantial cell damage. The cell membrane permeability, the content of membrane lipids, malondialdehyde and superoxide anion increased, but the intracellular pH and superoxide dismutase activities decreased, accompanying the increase of citric acid concentrations. The findings of this work provided a theoretical basis for the responsive mechanism of I. terricola WJL-G4 under high concentrations of citric acid, and can serve as a reference for biological acid reduction in fruit processing.

Water Stress Differentially Modulates the Expression of Tomato Cell Wall Metabolism-Related Genes in Meloidogyne incognita Feeding Sites.

Microscopic observations and transcriptomic RNA-Seq analyses were applied to investigate the effect of water stress during the formation of tomato galls formation 1 and 2 weeks after inoculation with the root-knot nematode Meloidogyne incognita. Water stress affected root growth and the nematode ability to mount an efficient parasitism. The effects of water stress on the feeding site development were already observed at 1 week after nematode inoculation, with smaller giant cells, delayed development, and thinner cell walls. These features suggested changes in the expression levels of genes involved in the feeding site formation and maintenance. Gene Ontology (GO) enrichment and expression patterns were used to characterize differentially expressed genes. Water stress modified the expression profile of genes involved in the synthesis, degradation, and remodeling of the cell wall during the development of nematode feeding site. A comparison of gene expression with unstressed galls revealed that water stress intensified the up or downregulation of most genes. However, it particularly influenced the expression pattern of expansin A11 (Solyc04g081870.4.1), expansin-like B1(Solyc08g077910.3.1), a pectin acetylesterase (Solyc08g005800.4.1), and the pectin methylesterase pmeu1 (Solyc03g123630.4.1) which were upregulated in unstressed galls and repressed by water stress, at both sampling times. The expression of most members of the genes involved in cell wall metabolism, i.e., those coding for Csl, fasciclin, and COBRA proteins, were negatively influenced. Interestingly, alteration in the expression profiles of most dirigent protein genes (DIRs) and upregulation of five gene coding for Casparian strip domain protein (CASP)-like proteins were found. Gene expression analysis of galls from water stressed plants allowed us to better understand the molecular basis of M. incognita parasitism in tomato. Specific genes, including those involved in regulation of cellulose synthesis and lignification process, require further study to develop defense strategies against root-knot nematodes.

Leaf Photosynthesis and Its Temperature Response Are Different between Growth Stages and N Supplies in Rice Plants.

Leaf photosynthesis is highly correlated with CO2-diffusion capacities, which are determined by both leaf anatomical traits and environmental stimuli. In the present study, leaf photosynthetic rate (A), stomatal conductance (gs), mesophyll conductance (gm) and the related leaf anatomical traits were studied on rice plants at two growth stages and with two different N supplies, and the response of photosynthesis to temperature (T) was also studied. We found that gm was significantly higher at mid-tillering stage and at high N treatment. The larger gm was related to a larger chloroplast surface area facing intercellular air spaces and a thinner cell wall in comparison with booting stage and zero N treatment. At mid-tillering stage and at high N treatment, gm showed a stronger temperature response. The modelling of the gm-T relationships suggested that, in comparison with booting stage and zero N treatment, the stronger temperature response of gm was related to the higher activation energy of the membrane at mid-tillering stage and at high N treatment. The findings in the present study can enhance our knowledge on the physiological and environmental determinants of photosynthesis.

CRISPR/Cas9‐mediated P‐CR domain‐specific engineering of CESA4 heterodimerization capacity alters cell wall architecture and improves saccharification efficiency in poplar

SummaryCellulose is the most abundant unique biopolymer in nature with widespread applications in bioenergy and high‐value bioproducts. The large transmembrane‐localized cellulose synthase (CESA) complexes (CSCs) play a pivotal role in the biosynthesis and orientation of the para‐crystalline cellulose microfibrils during secondary cell wall (SCW) deposition. However, the hub CESA subunit with high potential homo/heterodimerization capacity and its functional effects on cell wall architecture, cellulose crystallinity, and saccharification efficiency remains unclear. Here, we reported the highly potent binding site containing four residues of Pro435, Trp436, Pro437, and Gly438 in the plant‐conserved region (P‐CR) of PalCESA4 subunit, which are involved in the CESA4‐CESA8 heterodimerization. The CRISPR/Cas9‐knockout mutagenesis in the predicted binding site results in physiological abnormalities, stunt growth, and deficient roots. The homozygous double substitution of W436Q and P437S and heterozygous double deletions of W436 and P437 residues potentially reduced CESA4‐binding affinity resulting in normal roots, 1.5–2‐fold higher plant growth and cell wall regeneration rates, 1.7‐fold thinner cell wall, high hemicellulose content, 37%–67% decrease in cellulose content, high cellulose DP, 25%–37% decrease in cellulose crystallinity, and 50% increase in saccharification efficiency. The heterozygous deletion of W436 increases about 2‐fold CESA4 homo/heterodimerization capacity led to the 50% decrease in plant growth and increase in cell walls thickness, cellulose content (33%), cellulose DP (20%), and CrI (8%). Our findings provide a strategy for introducing commercial CRISPR/Cas9‐mediated bioengineered poplars with promising cellulose applications. We anticipate our results could create an engineering revolution in bioenergy and cellulose‐based nanomaterial technologies.

Using a Supercritical Fluid-Assisted Thin Cell Wall Stretching–Defoaming Method to Enhance the Nanofiller Dispersion, EMI Shielding, and Thermal Conduction Property of CNF/PVDF Nanocomposites

Using a Supercritical Fluid-Assisted Thin Cell Wall Stretching–Defoaming Method to Enhance the Nanofiller Dispersion, EMI Shielding, and Thermal Conduction Property of CNF/PVDF Nanocomposites

Application of genetic disruption of a Nannochloropsis oceanica cell wall synthesizing gene to n-3 HUFA enrichment of Brachionus plicatilis

It is believed that microalgae of the genus Nannochloropsis can replace fish oil as an n-3 highly unsaturated fatty acid (n-3 HUFA) source in live feed for sustainable marine fish larviculture. This is due to the fact that these microalgae are rich in eicosapentaenoic acid (EPA). On the other hand, the cell wall of microalgae is an obstacle to enriching live feed with n-3 HUFA. Manipulation of the cellulose synthase gene has the potential to facilitate degradation of the cell wall structure, although little is known how effective the genetically modified microalga would be in n-3 HUFA enrichment of live feed. This study aimed to evaluate the significance of the cellulose synthase gene-knockout strain (ΔCESA) of N. oceanica as an EPA enrichment diet for Brachionus plicatilis. The transgenic microalga was established via homologous recombination, and cultured under the same conditions as the wild-type strain (WT). According to the cellular ultrastructure, ΔCESA had a thinner cell wall than WT and its outer layer was unnaturally peeled back. Biochemical analysis revealed that with the exception of carbohydrates, WT and ΔCESA had comparable levels of proteins, lipids, and EPA. Carbohydrates were lower in ΔCESA than WT, which can cause changes in the cell wall structure. Digestive enzymatic and mechanical treatments of microalga showed ΔCESA to have higher accessibility of intracellular fatty acids. When microalga was used as the diet in the long-term cultivation of rotifers (1 week), rotifers fed ΔCESA presented higher growth rates than those fed WT. In short-term cultivation for rotifer EPA enrichment (≤24 h), the percentage of EPA in neutral lipids and phospholipids increased more rapidly in rotifers fed ΔCESA than those fed WT. As a result, rotifers fed ΔCESA for only 12 h exhibited comparable EPA levels to those fed WT for 24 h. The results of this study suggest that the efficiency of n-3 HUFA enrichment of rotifers is enhanced by feeding cellulose synthase gene-disrupted N. oceanica, due to the high vulnerability of its cell wall and unchanged nutritional value. Our findings provide evidence that gene modification technology can be applied to improve the targeted biological characteristics of microalgae used as the source of n-3 HUFA in marine larviculture.

Electroporation-coupled electrochemical oxidation for rapid and efficient water disinfection with Co3O4 nanowire arrays-modified graphite felt electrodes

Biologically unsafe drinking water occurs in developing regions lack of centralized water treatment plants. Herein, Co3O4 nanowire electrodes with Co3O4 nanowire arrays grown on graphite felt were fabricated and employed to construct a flow-through electrode system (FES) for rapid and efficient water disinfection, which achieved over 6.7-log E. coli removal under applied voltage of 2.5 V and flow rate of 65 mL/min (HRT ∼ 4.5 s) with energy consumption of 2.3 Wh/m3. The FES also achieved over 6.7-log removal at 2.5 V for the Gram-negative P. aeruginosa under ∼ 60 mL/min and for Gram-positive bacteria (E. faecalis and S. aureus) under ∼ 40 mL/min, and the Gram-negative bacteria were more vulnerable to FES disinfection than Gram-positive ones due to their larger sizes and thinner cell walls. In-situ sampling and live/dead backlight staining experiments revealed that pathogen inactivation mainly occurred on anode via the sequential adsorption, inactivation and desorption processes under the mass transfer forces of electric field attraction and flow scouring effect in porous electrodes. The disinfection mechanisms on the Co3O4 nanowire anode were recognized to be electroporation and electrochemical oxidation, and the pores generated by electroporation can provide diffusion channels for reactive species into the pathogen cells, promoting the disinfection performance.

Chemical and Structural Responses to Downregulated p-Hydroxycinnamoyl-Coenzyme A: Quinate/Shikimate p-Hydroxycinnamoyltransferase in Poplar Cell Walls.

Unraveling the impact of lignin reduction on cell wall construction of poplar stems is important for accurate understanding the regulatory role of biosynthetic genes. However, few cell-level studies have been conducted on the changes in lignin, other important cell wall composition, and the structural properties of transgenic poplar stems at different developmental stages. In this work, the content and microdistributions of cell wall composition as well as the morphological characteristics of cells were studied for p-hydroxycinnamoyl-coenzyme A:quinate/shikimate p-hydroxycinnamoyltransferase (HCT) downregulated transgenic poplar 84K (Populus alba × P. glandulosa cl. ‘84k’) at different developmental stages. Results show that the lignin contents of the upper, middle, and basal parts of HCT transgenic poplar stems were significantly decreased by 10.84, 7.40, and 7.75%, respectively; and the cellulose contents increased by 8.20, 6.45, and 3.31%, respectively, compared with the control group. The cellulose/lignin ratio of HCT transgenic poplars was therefore increased, especially in the upper sections, where it was 23.2% higher. Raman results indicate the appearance of p-hydroxyphenyl units (H) and a decrease in the ratio of syringyl/guaiacyl (S/G) lignin monomers in fiber cell walls of HCT transgenic poplars. In addition, microstructure observations revealed that the fiber and vessel cells of the HCT transgenic poplars exhibited thin cell walls and large lumen diameters. Compared with the control group, the cell wall thickness of fiber and vessel cells decreased by 6.50 and 10.93% on average, respectively. There was a 13.6% decrease in the average ratio of the cell wall thickness to the lumen diameter and an increase in fiber length and width of 5.60 and 6.11%, respectively. In addition, downregulation of HCT did not change the orientation of cellulosic microfibrils, but it led to an 11.1% increase of the cellulose crystallinity in cell walls compared to the control poplars. The information obtained herein could lead to a better understanding of the effects of genetic modifications on wood cell walls.

Microcellular PETs with High Expansion Ratio Produced by Supercritical CO2 Molding Compression Foaming Process and Their Mechanical Properties

Supercritical CO2 molding compression foaming is an emerging technology for preparing thick microcellular polymer sheets. In a temperature range of 245–255 °C and CO2 foaming pressure range of 5–20 MPa, the molding compression foaming behavior of polyethylene terephthalate (PET) is systematically studied. The maximum expansion ratio of the prepared PET foams is above 30, while the bubble size is only ≈20 μm. It is observed that during the foaming process, the temperature drop caused by rapid depressurization reaches up to 57 °C, which greatly changes the viscoelasticity of PET and limits its foaming behavior. The nucleation and bubble growth behavior of PET is simulated and analyzed based on this change in viscoelasticity. Microcellular PET foams have excellent compression performance due to their smaller cell size and thinner cell wall, and the compression elastic modulus of the prepared microcellular PET sample is twice that of the extrusion foaming PET sample with a similar expansion ratio.

Quantitative prediction of moisture content distribution in acetylated wood using near-infrared hyperspectral imaging

The uptake of moisture severely affects the properties of wood in service applications. Even local moisture content variations may be critical, but such variations are typically not detected by traditional methods to quantify the moisture content of the wood. In this study, we used near-infrared hyperspectral imaging to predict the moisture distribution on wood surfaces at the macroscale. A broad range of wood moisture contents were generated by controlling the acetylation degree of wood and the relative humidity during sample conditioning. Near-infrared image spectra were then measured from the surfaces of the conditioned wood samples, and a principal component analysis was applied to separate the useful chemical information from the spectral data. Moreover, a partial least squares regression model was developed to predict moisture content on the wood surfaces. The results show that hyperspectral near-infrared image regression can accurately predict the variations in moisture content across wood surfaces. In addition to sample-to-sample variation in moisture content, our results also revealed differences in the moisture content between earlywood and latewood in acetylated wood. This was in line with our recent studies where we found that thin-walled earlywood cells are acetylated faster than the thicker latewood cells, which decreases the moisture uptake during the conditioning. Dynamic vapor sorption isotherms validated the differences in moisture content within earlywood and latewood cells. Overall, our results demonstrate the capabilities of hyperspectral imaging for process analytics in the modern wood industry.Graphical abstract

Architects of their own environment: How membrane proteins shape the Gram-negative cell envelope.

Gram-negative bacteria are surrounded by a complex multilayered cell envelope, consisting of an inner and an outer membrane, and separated by the aqueous periplasm, which contains a thin peptidoglycan cell wall. These bacteria employ an arsenal of highly specialized membrane protein machineries to ensure the correct assembly and maintenance of the membranes forming the cell envelope. Here, we review the diverse protein systems, which perform these functions in Escherichia coli, such as the folding and insertion of membrane proteins, the transport of lipoproteins and lipopolysaccharide within the cell envelope, the targeting of phospholipids, and the regulation of mistargeted envelope components. Some of these protein machineries have been known for a long time, yet still hold surprises. Others have only recently been described and some are still missing pieces or yet remain to be discovered.

Wytrzymałość na ściskanie struktur komórkowych wytwarzanych techniką fotoutwardzania ciekłymi żywicami polimerowymi – Polyjet Matrix *

The article presents the results of compressive strength tests of cylindrical samples with a hexagonal cell structure. The samples were made of MED 610 material using the photo-curing technology liquid polymer resins. The compressive strength was estimated on the basis of a static compression test of the printed elements. It has been shown that the PolyJet Matrix 3D printing technology enables the printing models with a thin-walled cell structure, which, while maintaining the appropriate strength properties, can be used in the design and production of certain utility models.

Fluorescence assisted visualization and destruction of particles embedded thin cell walls in polymeric foams via supercritical foaming

Supercritical CO2 foaming is widely used to prepare microcellular foams and particles are frequently added to regulate cellular structure. Nevertheless, microcellular foams present a complicated structure (three-dimension cells and two-dimension cell walls embedded with particles), which is a huge challenge to enlighten scCO2 foaming behavior and corresponding properties. Therefore, a strategy was proposed to take fluorescence’s advantage of real-time and field visualization in scCO2 foaming: (1) cell wall rupture process was studied via in-situ visualization; (2) dual fluorescence design was used to construct particle dispersive state in a cell; (3) polystyrene particles were chemical fluorescence modified to resist strong extraction of scCO2 fluid. This work reveals that effect of particles on bubble nucleation is two folds: interface promoted bubble nucleation, but elastic strain energy inhibited bubble nucleation. By in-situ visualization, irregular particle dominates in initiating cracks in cell walls due to the much larger stress concentration compared with spherical particles.