Search

Abstract This review paper summarizes and critically discusses the morphology and structure formation of carbon fibers (CFs) from polymer precursor systems. Throughout this review, we focus on the key mutual interactions between the polymeric precursor systems, their physically determined processability into filaments, the thermally initiated crystal conversion mechanisms, as well as the morphological and physical properties of the resulting CFs and graphite fibers (GFs). Understanding the behavior of crystal conversion mechanisms from a polymeric semi-crystalline structure into a turbostratic, glass-like or even a graphite-like carbonaceous crystalline structure is essential to carbon and graphite fiber formation. The nature of the crystal conversion and thermal processing largely determine the recovery degree and behavior of the carbonaceous crystal orientation. Over the last three decades, CFs and GFs have earned a significant reputation as lightweight fibrous reinforcement materials, and considerable advances have been achieved in understanding the structure of CFs and GFs and in tailoring their performance towards specific applications. The utilization of CFs and GFs in different thermoplastics and thermosets, as well as in concrete as reinforcements, is well known thanks to the abundant number of reports and reviews available. Nevertheless, large-scale utilization of CFs in high-technology sectors, such as the aerospace industry, is mainly driven by the required performance of the CFs. For civilian applications such as general engineering and the automotive industry, however, the large-scale production of CFs is immensely limited by production costs. Numerous reports and reviews are available in the field of CFs and its precursors. Therefore, we focus on reviewing the less-discussed structure–property relationship and the influence of the different manufacturing processes on this relationship. Throughout this review, we identify areas that require future research and development regarding the morphology and structure formation of CFs from emerging precursor systems, e.g., lignin. [ABSTRACT FROM AUTHOR]

Innate immune responses face infectious microorganisms by inducing inflammatory responses. Multiple genes within distinct functional categories are coordinately and temporally regulated by transcriptional ‘on’ and ‘off’ switches that account for the specificity of gene expression in response to external stimuli. Mechanisms that control transcriptional and post-transcriptional regulation are important in coordinating the initiation and resolution of inflammation. Macrophage migration inhibitory factor (MIF) is an important cytokine that, in Ciona robusta , is related to inflammatory response. It is well known that in C. robusta, formerly known as Ciona intestinalis, the pharynx is involved in the inflammatory reaction induced by lipopolysaccharide (LPS) injection in the body wall. Using this biological system, we describe the identification of two C. robusta MIFs ( Cr MIF1 and Cr MIF2). The phylogenetic tree and modeling support a close relationship with vertebrate MIF family members. Cr MIF1 and Cr MIF2 possess two evolutionally conserved catalytic sites: a tautomerase and an oxidoreductase site with a conserved CXXC motif. Real-time PCR analysis shows a prompt expression induced by LPS inoculation in Cr MIF1 and a late upregulation of Cr MIF2 and in silico analyses of 3’UTR show a cis-acting GAIT element and a CPE element in 3’-UTR, which are not present in the 3’-UTR of Cr MIF1, suggesting that different transcriptional and post-transcriptional control mechanisms are involved in the regulation of gene expression of MIF during inflammatory response in C. robusta . [ABSTRACT FROM AUTHOR]

The selective modulation of immunity is an emerging concept driven by the vast advances in our understanding of this crucial host defense system. Invertebrates have raised researchers’ interest as potential sources of new bioactive molecules owing to their antibacterial, anticancer and immunomodulatory activities. A LipoPolySaccharide (LPS) challenge in the ascidian Ciona intestinalis generates the transcript, Ci 8 short, with cis -regulatory elements in the 3′ UTR region that are essential for shaping innate immune responses. The derived amino acidic sequence in silico analysis showed specific binding to human Major Histocompatibility Complex (MHC) Class I and Class II alleles. The role of Ci 8 short peptide was investigated in a more evolved immune system using human Peripheral Blood Mononuclear Cells (PBMCs) as in vitro model. The biological activities of this molecule include the activation of 70 kDa TCR ζ chain Associated Protein kinase (ZAP-70) and T Cell Receptor (TCR) Vβ oligo clonal selection on CD4 + T lymphocytes as well as increased proliferation and IFN-γ secretion. Furthermore Ci 8 short affects CD4 + /CD25 high induced regulatory T cells (iTreg) subset selection which co-expressed the functional markers TGF-β1/Latency Associated Protein (LAP) and CD39/CD73. This paper describes a new molecule that modulates important responses of the human adaptive immune system. [ABSTRACT FROM AUTHOR]

Although the Tumor necrosis factor gene superfamily seems to be very conserved in vertebrates, phylogeny, tissue expression, genomic and gene organization, protein domains and polymorphism analyses showed that a strong change has happened mostly in invertebrates in which protochordates were a constraint during the immune-molecules history and evolution. RT PCR was used to investigate differential gene expression in different tissues. The expression shown was greater in the pharynx. Single-nucleotide polymorphism has been investigated in Ciona intestinalis Tumor necrosis factor alpha (CiTNFα) mRNA isolated from the pharynx of 30 ascidians collected from Licata, Sicily (Italy), by denaturing gradient gel electrophoresis (DGGE). For this analysis, Ci TNFα nucleotide sequence was separated into two fragments, TNF-1 and -2, respectively, of 630 and 540 bp. We defined 23 individual DGGE patterns (named 1 to 10 for TNF-1 and 1 to 13 for TNF-2). Five patterns for TNF-1 accounted for <10% of the individuals, whereas the pattern 13 of TNF-2 accounted for >20% of the individuals. All the patterns were verified by direct sequencing. Single base-pair mutations were observed mainly within COOH-terminus, leading to 30 nucleotide sequence variants and 30 different coding sequences segregating in two main different clusters. Although most of the base mutations were silent, four propeptide variants were detected and six amino acid replacements occurred within COOH-terminus. Statistical tests for neutrality indicated negative selection pressure on signal and mature peptide domains, but possible positive selection pressure on COOH-terminus domain. Lastly we displayed the in silico 3D structure analysis including the Ci TNFα variable region. [ABSTRACT FROM AUTHOR]

The diversification of cellular functions is one of the major characteristics of multicellular organisms which allow cells to modulate their gene expression, leading to the formation of transcripts and proteins with different functions and concentrations in response to different stimuli. CAP genes represent a widespread family of proteins belonging to the cysteine-rich secretory protein, antigen 5 and pathogenesis-related 1 superfamily which, it has been proposed, play key roles in the infection process and the modulation of immune responses in host animals. The ascidian Ciona intestinalis represents a group of proto-chordates with an exclusively innate immune system that has been widely studied in the field of comparative and developmental immunology. Using this biological system, we describe the identification of a novel APA mechanism by which an intronic polyadenylation signal is activated by LPS injection, leading to the formation of a shorter CAP mRNA capable of expressing the first CAP exon plus 19 amino acid residues whose sequence is contained within the first intron of the annotated gene. Furthermore, such an APA event causes the expression of a translational controlling cis -acting GAIT element which is not present in the previously isolated CAP isoform and identified in the 3′-UTR of other immune-related genes, suggesting an intriguing scenario in which both transcriptional and post-transcriptional control mechanisms are involved in the activation of the CAP gene during inflammatory response in C. intestinalis . [ABSTRACT FROM AUTHOR]

Transforming growth factor (TGF-β) is a well-known component of a regulatory cytokines superfamily that has pleiotropic functions in a broad range of cell types and is involved, in vertebrates, in numerous physiological and pathological processes. In the current study, we report on Ciona intestinalis molecular characterisation and expression of a transforming growth factor β homologue ( Ci TGF-β). The gene organisation, phylogenetic tree and modelling supported the close relationship with the mammalian TGF suggesting that the C. intestinalis TGF-β gene shares a common ancestor in the chordate lineages. Functionally, real-time PCR analysis showed that Ci TGF-β was transcriptionally upregulated in the inflammatory process induced by LPS inoculation, suggesting that is involved in the first phase and significant in the secondary phase of the inflammatory response in which cell differentiation occurs. In situ hybridisation assays revealed that the genes transcription was upregulated in the pharynx, the main organ of the ascidian immune system, and expressed by cluster of hemocytes inside the pharynx vessels. These data supported the view that Ci TGF-β is a potential molecule in immune defence systems against bacterial infection. [ABSTRACT FROM AUTHOR]

ML superfamily represents a group of proteins playing important roles in lipid metabolism and innate immune response. In this study, we report the identification of the first component of the ML superfamily in the invertebrate Ciona intestinalis by means of a subtractive hybridization strategy. Sequence homology and phylogenetic analysis showed that this protein forms a specific clade with vertebrate components of the Niemann-Pick type C2 protein and, for this reason, it has been named Ci -NPC2. The putative Ci -NPC2 is a 150 amino acids long protein with a short signal peptide, seven cysteine residues, three putative lipid binding site and a three-dimensional model showing a characteristic β-strand structure. Gene expression analysis demonstrated that the Ci -NPC2 protein is positively upregulated after LPS inoculum with a peak of expression 1 h after challenge. Finally, in-situ hybridization demonstrated that the Ci -NPC2 protein is preferentially expressed in hemocytes inside the vessel lumen. [ABSTRACT FROM AUTHOR]

In humans, IL-17 is a proinflammatory cytokine that plays a key role in the clearance of extracellular bacteria promoting cell infiltration and production of several cytokines and chemokines. Here, we report on three Ciona intestinalis IL-17 homologues ( Ci IL17-1, Ci IL17-2, Ci IL17-3). The gene organization, phylogenetic tree and modeling supported the close relationship with the mammalian IL-17A and IL-17F suggesting that the C. intestinalis IL-17 genes share a common ancestor in the chordate lineages. Real time PCR analysis showed a prompt expression induced by LPS inoculation suggesting that they are involved in the first phase of inflammatory response. In situ hybridization assays disclosed that the genes transcription was upregulated in the pharynx, the main organ of the ascidian immune system, and expressed by hemocytes (granulocytes and univacuolar refractile granulocyte) inside the pharynx vessels. [ABSTRACT FROM AUTHOR]

Highlights: [•] The C. intestinalis peroxinectin contains a peroxidase domain and a KGD motif. [•] The CiPxt is a new member of the peroxidase–cyclooxygenase superfamily. [•] The phylogenetic tree revealed that the CiPxt is the closest to the chordate group. [•] Sequence analysis and structure showed high similarity of CiPxt to mammalian MPO. [•] Q-PCR analyses revealed that CiPxt mRNA expression was upregulated by LPS challenge. [Copyright &y& Elsevier]

Abstract: Stressful conditions include a prompt release of corticosteroid hormones which can mediate gene expression through glucocorticoid receptors (GR). Since two seabass (Dicentrarchus labrax) GRs have been cloned and sequenced from peritoneal cavity cells (DlGR1) and liver (DlGR2), a comparative amino acid sequence analysis that included Haplochromis burtoni HbGRs, was carried out and homologies disclosed. The DlGR1 and DlGR2 deduced aminoacid sequences showed 61% identity (I) and 70% similarity (S). Moreover, DlGR2 was similar to HbGR2b (69% I, 73% S), and the DlGR1 to HbGR1 (72% I, 78% S). In addition, we examined the expression of the DlGRs after exogeneous cortisol inoculation into the peritoneal cavity, mimicking stress effects. At various times after the administration (3h, 24h, 1week), gene expressions was evaluated in head kidney by real-time PCR. In addition, immunoblotting and densitometry analyses were performed with anti-DlGR1 antibodies. Although sea bass head kidney expressed both DlGR1 and DlGR2 they were differentially modulated by intraperitoneal implant of exogeneous cortisol. [Copyright &y& Elsevier]

Abstract: Collectins are a family of calcium-dependent lectins that are characterized by their collagen-like domains. Considerable interest has been focused on this class of proteins because of their ability to interact with components of the complement system activating a cascade of events responsible for the activation of the innate immune system. A differential screening between LPS-challenged and naïve Ciona intestinalis has been performed allowing the isolation of a full length cDNA encoding for a 221 AA protein. In silico analysis has shown that this polypeptide displays protein domains with similarities to mannose-binding lectins. A phylogenetic analysis suggested that C. intestinalis MBL has evolved early as a prototype of vertebrate MBL. Real-time PCR assay demonstrated that this gene is strongly activated after LPS injection in the tunica. In situ hybridization performed in LPS-induced animals has shown that this gene is expressed in granular amoebocytes and large granules hemocytes in the inflamed body wall tissue. Finally, an antimicrobial activity of the C. intestinalis MBL has been demonstrated. [Copyright &y& Elsevier]

Summary: Based on previous cloning and sequencing study, real-time PCR and in situ hybridization assays of the inflamed body wall of LPS-injected Ciona intestinalis showed the enhanced gene expression of a collagen with FACIT structural features (Ci-type IX-Col 1α-chain). By using specific antibodies raised against an opportunely chosen Ci-type IX-Col synthetic peptide, the fibroblast property of hemocytes challenged in vitro with LPS (at 4h) was displayed by flow cytometry, while immunocytochemistry identified hemocytes with large granules (morula cells) as collagen-producing cells. Hemocyte lysate supernatant analyzed in immunoblotting contained a 60kDa band identifiable as 1α-chain-Ci-type IX-Col. Observations of body wall sections (immunohistochemistry method) supported the role of hemocytes and showed that epidermis expressed Ci-type IX-Col 1α-chain in the time course of the inflammatory reaction (within 24h). Transcript and protein were mainly found in the epidermis that outlined the proximal side of the tunic matrix (at 24h after LPS injection), in cells associated with the epidermis at 4 and 192h. In conclusion, the C. intestinalis inflammatory response to LPS challenge appeared to be composed of a complex reaction set, and for the first time we showed in ascidians a granulation tissue with FACIT-collagen production that could participate in inflammation and wound healing. Like in vertebrates, C. intestinalis acute inflammatory reactions result in a regulated pattern of tissue repair with collagen expression during remodelling. Ci-type IX-Col could be involved in a network of non-fibril-forming collagens that participates in the organization of extracellular matrix and defense responses. [Copyright &y& Elsevier]

[Display omitted] • Acellular dermal matrix can be obtained with two days decellularization protocol. • Biomechanical properties of split-thickness acellular dermal matrix are maintained when compared with native skin. • DNA quantity in acellular dermal matrix is below 50 ng/mg dry tissue. • Collagen and GAGs quantity are maintained after decellularization process, however elastin diminish. Dermal scaffolds for tissue regeneration are nowadays an effective alternative in not only wound healing surgeries but also breast reconstruction, abdominal wall reconstruction and tendon reinforcement. The present study describes the development of a decellularization protocol applied to human split-thickness skin from cadaveric donors to obtain dermal matrix using an easy and quick procedure. Complete split-thickness donor was decellularized through the combination of hypertonic and enzymatic methods. To evaluate the absence of epidermis and dermal cells, and ensure the integrity of the extracellular matrix (ECM) structure, histological analysis was performed. Residual genetic content and ECM biomolecules (collagen, elastin, and glycosaminoglycan) were quantified and tensile strength was tested to measure the effect of the decellularization technique on the mechanical properties of the tissue. Biomolecules quantification, residual genetic content (below 50 ng/mg dry tissue) and histological structure assessment showed the efficacy of the decellularization process and the preservation of the ECM. The biomechanical tests confirmed the preservation of native properties in the acellular tissue. The acellular dermal matrix obtained from whole split-thickness skin donor with the newly developed decellualrization protocol, maintains the desired biomechanical and structural properties and represents a viable treatment option for patients. [ABSTRACT FROM AUTHOR]

The study aimed to apply biosilica nanoparticles from renewable resources for improving soil quality as a type of fertilizer carier. The silica particles having a purity of about 98 % were extracted from rice husk at the calcination temperatures of 550 °C, 600 °C, 650 °C, and 700 °C. The required materials properties were investigated by advanced measurement techniques. All samples showed the amorphous structure with Si–O–Si bond and the particles' agglomeration with the average size of 10–50 nm and principle electronic structures with the typical spectra of Si and O 2. When the synthesized silica was used as the medium to release absorbed nutrients in a controlled manner, surface properties, including the Brunauer–Emmett–Teller area and the average pore diameter were evaluated between 179 m2/g to 570 m2/g, and 4 nm–40 nm, respectively. The measured electrokinetic potential of the synthesized particles was between −20 mV and −36 mV guaranteeing the stability when they are dispersed in the aqueous environment. The experimental results showed that the silica particles calcinated at 650 °C had the best properties. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is linked to immune-mediated pathogenesis and a pro-inflammatory state, leading to accelerated atherosclerosis. This earlier onset of clinical cardiovascular disease poses significant morbidity and mortality. We sought to identify IHD mortality trends in individuals with IBD in the United States (US). Mortality due to ischemic heart diseases (IHD) as the underlying cause of death with the IBD as a contributor of death were queried from death certificates using the CDC database from 1999 to 2020. Yearly crude mortality rates (CMR) were estimated by dividing the death count by the respective population size, reported per 100,000 persons. Mortality rates were adjusted for age using the Direct method and compared by demographic subpopulations. Log-linear regression models were utilized to assess temporal variation (annual percentage change [APC]) in mortality. Age-adjusted mortality rates (AAMR) decreased from 0.11 in 1999 to 0.07 in 2020, primarily between 1999 and 2018 (APC -4.41, p < 0.001). AAMR was higher among male (AAMR 0.08) and White (AAMR 0.08) populations compared to female populations (AAMR 0.06) and Black (AAMR 0.04) populations, respectively. No significant differences were seen when comparing mortality between urban (AAMR 0.07) and rural (AAMR 0.08) regions. Southern US regions (AAMR 0.06) had the lowest mortality rates when compared to the other US census regions: Northeastern (AAMR 0.08), Midwestern (AAMR 0.08), and Western (AAMR 0.08). Disparities in IHD mortality exist among individuals with IBD in the US based on demographic factors, with an overall decline in mortality during the 22-year period. Further investigation is warranted to confirm these findings and evaluate for contributors to the observed disparities. [Display omitted] • Ischemic heart disease mortality in populations with inflammatory bowel disease has decreased in recent years. • Ischemic heart disease mortality disproportionally impacted male and White populations with inflammatory bowel disease. • Southern regions had the lowest ischemic heart disease mortality in populations with inflammatory bowel disease. [ABSTRACT FROM AUTHOR]

Lysozyme is an important defense molecule of the innate immune system. Known for its bactericidal properties, lysozyme catalyzes the hydrolysis of b-(1,4)-glycosidic bonds between the N-acetyl glucosamine and N-acetyl muramic acid in the peptidoglycan layer of bacterial cell walls. In this study, the complete coding sequence of four g-type lysozymes were identified in Ciona intestinalis . Phylogenetic analysis and modelling supported the hypothesis of a close relationship with the vertebrate g-type lysozymes suggesting that the C. intestinalis g-type lysozyme genes ( Ci Lys-g1, Ci lys-g2, Ci Lys-g3, Ci Lys-g4) share a common ancestor in the chordate lineage. Protein motif searches indicated that C. intestinalis g-type lysozymes contain a GEWL domain with a GXXQ signature, typical of goose lysozymes. Quantitative Real-Time PCR analysis results showed that transcripts are expressed in various tissues from C. intestinalis . In order to determine the involvement of C. intestinalis g-type lysozymes in immunity, their expression was analyzed in the pharynx, showing that transcripts were significantly up-regulated in response to a challenge with lipopolysaccharide (LPS). These data support the view that Ci Lys g-type are molecules with potential for immune defense system against bacterial infection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional building materials for lightweight and sustainable construction. • TE-enabled n-type MCF-based reinforcements with 1.1 μW/m.K2 power factor. • TE-enabled p-type MCF-based reinforcements with 17.1 μW/m.K2 power factor. • In-plane TEG-enabled reinforcing device with 22.3 nW power output. This proof-of-concept study demonstrates for the first time the fabrication of a multifunctional reinforcing grid-building material within a thermoelectric element generator (TEG) configuration. Commercially available carbon fiber yarns, which possess inherent Seebeck coefficient (S) values of −2.5 μV/K (n-type) and +7.4 μV/K (p-type), were thoroughly investigated prior to their impregnation with a geopolymer (GP)-based suspension. The resulting hardened mineral-impregnated carbon-fiber (MCF) reinforcements were subsequently tested regarding their physicochemical and mechanical properties. Afterward, individual MCFs were employed as n-/p-type thermoelements to assemble a grid-like TEG consisting of five serially interconnected junctions. The TEG-enabled reinforcing grid exhibited a voltage output of 1.8 mV, corresponding to a generated power of 22.3 nW upon exposure to an in-plane temperature difference (Δ T) of 50 K. Multifunctional building materials are envisaged to exploit thermal gradients on a large-scale during their service lifetime, contributing towards zero energy consumption constructions. [ABSTRACT FROM AUTHOR]

There has been ever raising concern in last few decades about the utilization of biomass for different commercial applications such as filler materials in rubber composites. In this context, an interesting pathway has been proposed to develop such composites by introducing waste lignin as a reinforcing constituent in high cis-polybutadiene rubber (BR). With a judicious selection of rubber curing ingredients and, simultaneously, adopting suitable solid-state mixing protocols, particularly, a relatively high-temperature multi-steps melt-mixing process (above the glass transition temperature of lignin), rubber composites with an outstanding mechanical performance were prepared. The reinforced rubber composites with 50 (weight) parts lignin loading per hundred parts of rubber (phr) offer ∼10 MPa tensile strength (TS), ∼276% elongation at break (EB), and ∼3.51 MPa tensile stress at 100% elongation (so-called rubber modulus M 100). These values are superior when compared with the composites comprised with standard reinforcing carbon black (∼8.5 TS, ∼224% EB, ∼2.79 M 100) and even with a silica-silane system (∼7.34 TS, ∼229% EB, ∼2.44 M 100) with same filler loading. The unique combination of the curing packages and four-stage mixing process allowed us to establish a homogeneous and fine dispersion of lignin. Furthermore, this is the first time that available models of rubber reinforcement are applied to the description of the reinforcement mechanisms of lignin in a soft elastomer involving various aspects like filler-filler interaction, rubber-filler interactions, critical strains for destroying the filler-filler network, effective filler volume fractions, shape factor, etc. The developed compounding methods for BR and their characterization and modeling can be easily applied to other commercial rubbers facilitating a real breakthrough in developing cheap and bio-based high-performance rubber composites. [Display omitted] • Utilization of lignin as value added rubber reinforcing agent. • High temperature mixing of kraft lignin with polybutadiene rubber. • Comparison reinforcing capacity of different types of lignin. • Dispersion of lignin by use of coupling agent. • Comparable reinforcing ability of lignin with reinforcing carbon back. [ABSTRACT FROM AUTHOR]