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Dissemination of cancer cells from the primary tumor into distant body tissues and organs is the leading cause of death in cancer patients. While most clinical strategies aim to reduce or impede the growth of the primary tumor, no treatment to eradicate metastatic cancer exists at present. Metastasis is mediated by feet-like cytoskeletal structures called invadopodia which allow cells to penetrate through the basement membrane and intravasate into blood vessels during their spread to distant tissues and organs. The non-receptor tyrosine kinase Pyk2 is highly expressed in breast cancer, where it mediates invadopodia formation and function via interaction with the actin-nucleation-promoting factor cortactin. Here, we designed a cell-permeable peptide inhibitor that contains the second proline-rich region (PRR2) sequence of Pyk2, which binds to the SH3 domain of cortactin and inhibits the interaction between Pyk2 and cortactin in invadopodia. The Pyk2-PRR2 peptide blocks spontaneous lung metastasis in immune-competent mice by inhibiting cortactin tyrosine phosphorylation and actin polymerization-mediated maturation and activation of invadopodia, leading to reduced MMP-dependent tumor cell invasiveness. The native structure of the Pyk2-PRR2:cortactin-SH3 complex was determined using nuclear magnetic resonance (NMR), revealing an extended class II interaction surface spanning the canonical binding groove and a second hydrophobic surface which significantly contributes to ligand affinity. Using structure-guided design, we created a mutant peptide lacking critical residues involved in binding that failed to inhibit invadopodia maturation and function and consequent metastatic dissemination in mice. Our findings shed light on the specific molecular interactions between Pyk2 and cortactin and may lead to the development of novel strategies for preventing dissemination of primary breast tumors predicted at the time of diagnosis to be highly metastatic, and of secondary tumors that have already spread to other parts of the body.

Severe SARS-CoV-2 infection1 has been associated with highly inflammatory immune activation since the earliest days of the COVID-19 pandemic2–5. More recently, these responses have been associated with the emergence of self-reactive antibodies with pathologic potential6–10, although their origins and resolution have remained unclear11. Previously, we and others have identified extrafollicular B cell activation, a pathway associated with the formation of new autoreactive antibodies in chronic autoimmunity12,13, as a dominant feature of severe and critical COVID-19 (refs. 14–18). Here, using single-cell B cell repertoire analysis of patients with mild and severe disease, we identify the expansion of a naive-derived, low-mutation IgG1 population of antibody-secreting cells (ASCs) reflecting features of low selective pressure. These features correlate with progressive, broad, clinically relevant autoreactivity, particularly directed against nuclear antigens and carbamylated proteins, emerging 10–15 days after the onset of symptoms. Detailed analysis of the low-selection compartment shows a high frequency of clonotypes specific for both SARS-CoV-2 and autoantigens, including pathogenic autoantibodies against the glomerular basement membrane. We further identify the contraction of this pathway on recovery, re-establishment of tolerance standards and concomitant loss of acute-derived ASCs irrespective of antigen specificity. However, serological autoreactivity persists in a subset of patients with postacute sequelae, raising important questions as to the contribution of emerging autoreactivity to continuing symptomology on recovery. In summary, this study demonstrates the origins, breadth and resolution of autoreactivity in severe COVID-19, with implications for early intervention and the treatment of patients with post-COVID sequelae.

Mechanical fields over thin elastic surfaces can develop singularities at isolated points and curves in response to constrained deformations (e.g., crumpling and folding of paper), singular body forces and couples, distributions of isolated defects (e.g., dislocations and disclinations), and singular metric anomaly fields (e.g., growth and thermal strains). With such concerns as our motivation, we model thin elastic surfaces as von K{\'a}rm{\'a}n plates and generalize the classical von K{\'a}rm{\'a}n equations, which are restricted to smooth fields, to fields which are piecewise smooth, and can possibly concentrate at singular curves, in addition to being singular at isolated points. The inhomogeneous sources to the von K{\'a}rm{\'a}n equations, given in terms of plastic strains, defect induced incompatibility, and body forces, are likewise allowed to be singular at isolated points and curves in the domain. The generalized framework is used to discuss the singular nature of deformation and stress arising due to conical deformations, folds, and folds terminating at a singular point.

Item does not contain fulltext PURPOSE: Insights into the severity of co-existing symptoms can help in identifying breast cancer survivors in need of symptom management. We aimed to identify subgroups of breast cancer survivors based on patterns of symptom severity, and characteristics associated with these subgroups. METHODS: We selected surgically treated stage I-III breast cancer survivors 1-5 years post-diagnosis from the Netherlands Cancer Registry (N = 876). We assessed experienced severity of fatigue, nausea, pain, dyspnea, insomnia, appetite, constipation, diarrhea, and emotional and cognitive symptoms through the EORTC-QLQ-C30 Quality of Life Questionnaire on a scale of 0-100. We determined subgroups of survivors using latent class cluster analyses (LCA) based on severity of co-existing symptoms and compared their mean severity to the age-matched female reference population to interpret clinical relevance. We assessed subgroup characteristics by multinomial logistic regression analyses. RESULTS: From 404 respondents (46%), three subgroups of survivors with distinct symptom severity were identified: low severity (n = 116, 28.7%), intermediate severity (n = 224, 55.4%), and high severity (n = 59, 14.6%). The low subgroup reported lower symptom severity than the general population; the intermediate subgroup reported a similar symptom severity, although scores for fatigue, insomnia, and cognitive symptoms were worse (small-medium clinical relevance). The high subgroup had worse symptom severity (medium-large clinical relevance). Compared to the intermediate subgroup, one (RRR: 2.75; CI: 1.22-6.19; p = 0.015) or more (RRR: 9.19; CI: 3.70-22.8; p =

Researchers have scrutinized cartilage tissue regeneration to handle the deficiency of cartilage restoration capacity. This investigation proposed to compose an innovative nanocomposite biomaterial that enhances growth factor delivery to the injured cartilage site. Here, we describe the design and development of the biocompatible PLGA-collagen / PLGA-PEG-PLGA nanocomposite scaffold containing TGF-β1. PLGA-PEG-PLGA nanoparticles were employed as a delivery system embedding TGF-β1 as an articular cartilage repair therapeutic agent. This study evaluates various physicochemical aspects of fabricated scaffolds by 1HNMR, FT-IR, SEM, BET, and DLS methods. The physicochemical features of the developed scaffolds, including porosity, density, degradation, swelling ratio, mechanical properties, morphologies, BET, ELIZA, and cytotoxicity were assessed. SEM images displayed suitable cell adhesion and distribution of hDPSCs throughout the scaffolds. The cell viability was investigated with the MTT test. In real-time PCR testing, the expression of Sox-9, collagen type II, and aggrecan genes was monitored. According to the results, h-DPSCs exhibited high adhesion, proliferation, and differentiation on PLGA-collagen/PLGA-PEG-PLGA-TGF-β1 hydrogels compared to the control groups. RT-PCR assay data displayed that TGF-β1 loaded PLGA-PEG-PLGA nanoparticles puts forward chondroblast differentiation in hDPSCs through the expression of chondrogenic genes. Due to its potential for the growth and differentiation of hDPSCc, PLGA-collagen/PLGA-PEG-PLGA-TGF-β1 hydrogel is likely to be a suitable biomaterial for cartilage regeneration.

Funder: The Marks lab is supported by an NWO-XS grant, Funder: M.V. is part of the Oncode Institute, which is partly funded by the Dutch Cancer Society, Funder: D.W.Z. is part of the Oncode Institute, which is partly funded by the Dutch Cancer Society, Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here we define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Our integrated analysis reveals differences in the relative abundance and activities of distinct chromatin modules. We identify a strong enrichment of polycomb repressive complex 2 (PRC2)-associated H3K27me3 in the chromatin of naive pluripotent stem cells and H3K27me3 enrichment at promoters of lineage-determining genes, including trophoblast regulators. PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, whereas inhibition of PRC2 promotes trophoblast-fate induction and cavity formation in human blastoids. Together, our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates.

The spatial organization of cell membrane glycoproteins and glycolipids is critical for mediating the binding of ligands, receptors, and macromolecules on the plasma membrane. However, we currently do not have the methods to quantify the spatial heterogeneities of macromolecular crowding on live cell surfaces. In this work, we combine experiment and simulation to report crowding heterogeneities on reconstituted membranes and live cell membranes with nanometer spatial resolution. By quantifying the effective binding affinity of IgG monoclonal antibodies to engineered antigen sensors, we discovered sharp gradients in crowding within a few nanometers of the crowded membrane surface. Our measurements on human cancer cells support the hypothesis that raft-like membrane domains exclude bulky membrane proteins and glycoproteins. Our facile and high-throughput method to quantify spatial crowding heterogeneities on live cell membranes may facilitate monoclonal antibody design and provide a mechanistic understanding of plasma membrane biophysical organization., 31 pages, 4 figures. See Supporting Information in Ancillary files (1 appendix, 3 movies)

Structures of two globular proteins were determined ab initio using microcrystal electron diffraction (MicroED) data that were collected on a direct electron detector in counting mode. Microcrystals were identified using a scanning electron microscope (SEM) and thinned with a focused ion beam (FIB) to produce crystalline lamellae of ideal thickness. Continuous-rotation data were collected using an ultra-low exposure rate to enable electron counting in diffraction. For the first sample, triclinic lysozyme extending to a resolution of 0.87 Å, an ideal helical fragment of only three alanine residues provided initial phases. These phases were improved using density modification, allowing the entire atomic structure to be built automatically. A similar approach was successful on a second macromolecular sample, proteinase K, which is much larger and diffracted to a resolution of 1.5 Å. These results demonstrate that macromolecules can be determined to sub-ångström resolution by MicroED and that ab initio phasing can be successfully applied to counting data.

The purpose of this randomized controlled study is to determine if an interactive power toothbrush (PTB) with application (app) promotes additional benefit on dental plaque, gingivitis, and gingival abrasion to that of a manual toothbrush (MTB).Ninety participants (dental students) diagnosed with gingivitis were randomly assigned, into three groups, 1:1:1 ratio, given an app-assisted interactive PTB (PTB-A) (Oral-B Genius® Rechargeable 8000 PTB with CrossAction brush head) or the same PTB without app-assistance (PTB-NA) or a regular MTB for home-use. Plaque was assessed using the Turesky modification of the Quigley and Hein Plaque Index (QHPI-TM), and gingivitis was evaluated using the Bleeding on Marginal Probing Index (BOMP) at baseline (T0), week 2 (T1), and week 8 (T2). Gingival abrasions were recorded at T1 and T2. Exit survey was used to assess brushing time and visual-analogue-scale (VAS) scores.PTB improved QHPI-TM significantly in terms of time-dependent changes, irrespective of app-assistance. BOMP was observed to be statistically lower in PTB-A than in MTB only at T2. Brushing times were longer in PTB-A than in MTB. Gingival abrasion was less in both PTB than MTB. PTB-A had better results to MTB in cleaning ability according to subject-reported outcomes.Both PTBs were more effective to MTB; however, the app-assisted interactive PTB was similar to the non-assisted one in plaque removal efficacy, gingivitis reduction, and incidence of gingival abrasion, yet better than MTB in cleaning ability.Developing an application software to prevent gingival abrasion might be clinically beneficial regardless of the individual factor.ClinicalTrial.gov ID: NCT05150132.

Carboxymethyl chitosan (CMC) as a bio-based osteochondral inductive material was chemically immobilized on the surface of polycaprolactone (PCL) nanofibers to fabricate scaffolds for osteochondral tissue engineering applications. The chemical immobilization process included the aminolysis of ester bonds and bonding of the primary amines with glutaraldehyde as a coupling agent. The SEM and FTIR results confirmed the successfulness of the CMC immobilization. The fabricated scaffolds presented cell viabilities of > 82% and supported the attachment and proliferation of the human bone marrow mesenchymal stem cells (hBM-MSCs). The CMC-immobilized scaffolds concentration dependently induced the diverse osteochondral differentiation pathways for the hBM-MSCs without using any external differential agents. According to the Alcian Blue and Alizarin Red staining and immunocytochemistry results, scaffolds with a higher content of CMC presented more chondro-inductivity and less osteoinductivity. Thus, the CMC-immobilized scaffolds can be employed as great potential candidates for osteochondral tissue engineering applications.

The differentiation, migration, and proliferation of skin fibroblasts are identified as key factors in cutaneous wound healing. Adipose-derived mesenchymal stem cells (ADMSCs) and their exosomes (ADMSC-Exos) have been considered as potential therapeutic tools for tissue regeneration; however, the underlying mechanisms on cutaneous wound healing are still not well understood. In this study, we successfully obtained ADMSC-Exos and found ADMSC-Exos significantly promoted the migration and proliferation of fibroblasts in a dose-dependent manner in vitro. The expression levels of COL-I and COL-III in fibroblasts treated with ADMSC-Exos were significantly increased, while the expression level of α-SMA was decreased. In addition, the enhanced protein expression of WNT2b and β-catenin confirmed the activation of the WNT/β-catenin signaling pathway and the WNT/β-catenin inhibitor (XAV939) reversed the promoting effect of ADMSC-Exos on wound healing and the β-catenin expression. Taken together, our study partially elucidates the mechanism of ADMSC-Exos in wound healing, illustrating the potential of ADMSC-Exos as a new therapeutic approach to promote skin wound healing. Graphical Abstract

Cell migration depends on the dynamic organization of the actin cytoskeleton and assembly and disassembly of focal adhesions (FA). However the precise mechanisms coordinating these processes remain poorly understood. We previously identified the estrogen-related receptor α (ERRα) as a major regulator of cell migration. Here, we show that loss of ERRα leads to abnormal accumulation of actin filaments that is associated with an increase in the level of inactive form of the actin-depolymerizing factor cofilin. We further show that ERRα depletion decreases cell adhesion and promotes defective FA formation and turnover. Interestingly, specific inhibition of the RhoA-ROCK-LIMK-cofilin pathway rescues the actin polymerization defects resulting from ERRα silencing, but not cell adhesion. Instead we found that MAP4K4 is a direct target of ERRα and down-regulation of its activity rescues cell adhesion and FA formation in the ERRα-depleted cells. Altogether, our results highlight a crucial role of ERRα in coordinating the dynamic of actin network and focal adhesion through the independent regulation of the RhoA and MAP4K4 pathways.

Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) are histone-modifying and -binding complexes that mediate the formation of facultative heterochromatin and are required for silencing of developmental genes and maintenance of cell fate1–3. Multiple pathways of RNA decay work together to establish and maintain heterochromatin in fission yeast, including a recently identified role for a conserved RNA-degradation complex known as the rixosome or RIX1 complex4–6. Whether RNA degradation also has a role in the stability of mammalian heterochromatin remains unknown. Here we show that the rixosome contributes to silencing of many Polycomb targets in human cells. The rixosome associates with human PRC complexes and is enriched at promoters of Polycomb target genes. Depletion of either the rixosome or Polycomb results in accumulation of paused and elongating RNA polymerase at Polycomb target genes. We identify point mutations in the RING1B subunit of PRC1 that disrupt the interaction between PRC1 and the rixosome and result in diminished silencing, suggesting that direct recruitment of the rixosome to chromatin is required for silencing. Finally, we show that the RNA endonuclease and kinase activities of the rixosome and the downstream XRN2 exoribonuclease, which degrades RNAs with 5′ monophosphate groups generated by the rixosome, are required for silencing. Our findings suggest that rixosomal degradation of nascent RNA is conserved from fission yeast to human, with a primary role in RNA degradation at facultative heterochromatin in human cells.

Polymerization of actin into cytoskeletal filaments is coupled to its bound adenine nucleotides. The mechanism by which nucleotide modulates actin functions has not been evident from analyses of ATP- and ADP-bound crystal structures of the actin monomer. We report that NMR chemical shift differences between the two forms are globally distributed. Furthermore, microsecond–millisecond motions are spread throughout the molecule in the ATP form, but largely confined to subdomains 1 and 2, and the nucleotide binding site in the ADP form. Through these motions, the ATP- and ADP-bound forms sample different high-energy conformations. A deafness-causing, fast-nucleating actin mutant populates the high-energy conformer of ATP-actin more than the wild-type protein, suggesting that this conformer may be on the pathway to nucleation. Together, the data suggest a model in which differential sampling of a nucleation-compatible form of the actin monomer may contribute to control of actin filament dynamics by nucleotide.

Key message The article concerns the association between callose synthase and cytoskeleton by biochemical and ultrastructural analyses in the pollen tube. Results confirmed this association and immunogold labeling showed a colocalization. Abstract Callose is a cell wall polysaccharide involved in fundamental biological processes, from plant development to the response to abiotic and biotic stress. To gain insight into the deposition pattern of callose, it is important to know how the enzyme callose synthase is regulated through the interaction with the vesicle-cytoskeletal system. Actin filaments likely determine the long-range distribution of callose synthase through transport vesicles but the spatial/biochemical relationships between callose synthase and microtubules are poorly understood, although experimental evidence supports the association between callose synthase and tubulin. In this manuscript, we further investigated the association between callose synthase and microtubules through biochemical and ultrastructural analyses in the pollen tube model system, where callose is an essential component of the cell wall. Results by native 2-D electrophoresis, isolation of callose synthase complex and far-western blot confirmed that callose synthase is associated with tubulin and can therefore interface with cortical microtubules. In contrast, actin and sucrose synthase were not permanently associated with callose synthase. Immunogold labeling showed colocalization between the enzyme and microtubules, occasionally mediated by vesicles. Overall, the data indicate that pollen tube callose synthase exerts its activity in cooperation with the microtubular cytoskeleton.

The chemical composition of melanoidins formed from glucose (Glc) and alanine (Ala) in different molar ratios was investigated using UV/Vis, FTIR, EPR spectroscopy and elemental analysis (EA). Melanoidin samples were prepared at varying molar ratios of Glc and Ala ranging from 10:1 to 1:10 (Glc:Ala). Reaction systems containing a higher molar ratio of Ala show higher melanoidin yields and higher UV/Vis absorbance. This indicates that an excess of Ala facilitates the formation of larger π-electron systems and catalyzes the melanoidin formation. EPR spectroscopy showed more radicals in Ala enriched samples. The EA data suggest that during the formation of melanoidin from Glc and Ala higher amounts of amino acid support dehydration of the reaction products. On the basis of our data, we postulate the structures of products and intermediates for the reaction at different Glc/Ala ratios. PCA of the FTIR spectra allows to separate different melanoidin samples formed at varying molar ratios indicating their different molecular compositions.

The mechanical and physical properties of lignocellulosic materials are closely related to the orientation and interaction of the polymers within cell walls. In this work, Imaging Polarized FTIR, combined with directional chemical removal, was applied to characterize the spatial orientation and interaction of cell wall polymers in bamboo fibers and parenchyma cells from two bamboo species. The results demonstrate the cellulose in bamboo fibers is nearly axially oriented whereas it is almost transversely arranged in parenchyma cells. Xylan and lignin are both preferentially oriented alongside cellulose, but with less orientation degre in the parenchyma cells. After lignin removal, the average orientation of xylan and cellulose is little affected, suggesting a strong interaction between cellulose and xylan. Meanwhile, the alkaline treatment significantly weakens the orientation of lignin in both fibers and parenchyma cells, and more significant for the latter, indicating the easy-degradable nature of lignin in parenchyma cells. And, it seemed the lignin and xylan in fibers were more difficult to be removed as compared to parenchyma cells, supporting the assumption that stronger interaction exists between lignin and xylan in the fibers. In a word, it was believed parenchyma cells are more suitable for biorefinery owing to its less ordered and relatively loose molecular assembly, as compared to fibers.

Understanding the relationship of COVID-19 to stroke is important. We compare characteristics of pre-pandemic stroke (PPS), cases in acute COVID infection (CS) and in patients who have recovered from COVID-19 infection (RCS). We interrogated the Qatar stroke database for all stroke admissions between Jan 2020 and Feb 2021 (PPS) to CS and RCS to determine how COVID-19 affected ischemic stroke sub-types, clinical course, and outcomes prior to, during and post-pandemic peak. There were 3264 cases admitted (pre-pandemic: 3111, stroke in COVID-19: 60 and recovered COVID-19 stroke: 93). Patients with CS were significantly younger, had more severe symptoms, fever on presentation, more ICU admissions and poor stroke recovery at discharge when compared to PPS and RCS. Large vessel disease and cardioembolic disease was significantly higher in CS compared to PPS or RCS. There was a significant decline in stroke mimics in CS. Stroke in RCS has characteristics similar to PPS with no evidence of lasting effects of the virus on the short-term. However, CS is a more serious disease and tends to be more severe and have a poor prognosis.Other Information Published in: Journal of Thrombosis and Thrombolysis License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s11239-021-02581-6

Doxorubicin (DOX) is a potent chemotherapeutic agent; however, it causes severe heart injury via apoptosis induction in many patients. DOX-induced cardiotoxicity is attenuated by activated autophagy in the heart. We previously found that programmed cell death 1 (Pdcd1), an immune checkpoint receptor, inhibits DOX-induced cardiomyocyte apoptosis. In this study, we investigated whether autophagy contributes to the protective role of Pdcd1 against DOX-induced cardiomyocyte apoptosis. We also examined the role of Pdcd1 in DOX-induced apoptosis in cancer cells. Rat cardiomyocyte cell line H9c2 and human cancer cell lines K562 and MCF-7 were transfected with Pdcd1-encoding plasmid DNA to establish Pdcd1-overexpressing cells. Apoptosis and autophagy were determined using a luciferase assay. In H9c2 cells, DOX-induced apoptosis and viability reduction occurred through caspase activation. In particular, Pdcd1 overexpression activated the autophagy pathway through the inhibition of the mammalian target of rapamycin, a major negative regulator of autophagy. Moreover, it prevented DOX-induced cardiomyocyte apoptosis; a similar cardioprotection was observed when normal H9c2 cells (without Pdcd1 overexpression) were treated with rapamycin, an autophagy inducer, before the DOX treatment. Conversely, in cancer cells, Pdcd1 overexpression increased both basal and DOX-induced apoptosis. The role of Pdcd1 in DOX-induced apoptosis in cardiomyocytes and cancer cells was opposing. Pdcd1 signaling prevented DOX-induced apoptosis in cardiomyocytes, through autophagy induction; it enhanced DOX-induced apoptosis in cancer cells. Therefore, Pdcd1 could be a critical molecule for more effective and safer DOX chemotherapy.

Epigenetics, including histone modifications, play a significant role in central nervous system diseases, but the underlying mechanism remains to be elucidated. The aim of this study was to evaluate the role of H3K27me3 in regulating transcriptomic and pathogenic mechanisms following global ischemic stroke. Here, we found that in vivo ischemic/reperfusion (I/R) injury induced marked upregulation of H3K27me3 in the hippocampus. The administration of GSK-126 to rat brains decreased the levels of H3K27me3 in the hippocampus and reduced neuronal apoptosis after experimental stroke. Furthermore, ChIP-seq data demonstrated that the primary role of GSK-126 in the ischemic brain is to reduce H3K27me3 enrichment, mediating negative regulation of the execution phase of apoptosis and the MAPK signaling pathway. Further study suggested that the protective role of GSK-126 in ischemic rats was antagonized by U0126, an inhibitor of ERK1/2. Collectively, we demonstrated the potential of H3K27me3 as a novel stroke therapeutic target, and GSK-126 exerted a neuroprotective function in ischemic brain injury, which might be associated with activation of the MAPK/ERK pathway. Graphical Abstract

Multimeric and polymeric proteins are large biomacromolecules consisting of multiple protein molecules as their monomeric units, connected through covalent or non-covalent bonds. Genetic modification and post-translational modifications (PTMs) of proteins offer alternative strategies for designing and creating multimeric and polymeric proteins. Multimeric proteins are commonly prepared by genetic modification, whereas polymeric proteins are usually created through PTMs. There are two methods that can be applied to create polymeric proteins: self-assembly and crosslinking. Self-assembly offers a spontaneous reaction without a catalyst, while the crosslinking reaction offers some catalyst options, such as chemicals and enzymes. In addition, enzymes are excellent catalysts because they provide site-specificity, rapid reaction, mild reaction conditions, and activity and functionality maintenance of protein polymers. However, only a few enzymes are applicable for the preparation of protein polymers. Most of the other enzymes are effective only for protein conjugation or labeling. Here, we review novel and applicable strategies for the preparation of multimeric proteins through genetic modification and self-assembly. We then describe the formation of protein polymers through site-selective crosslinking reactions catalyzed by enzymes, crosslinking reactions of non-natural amino acids, and protein-peptide (SpyCatcher/SpyTag) interactions. Finally, we discuss the potential applications of these protein polymers.

Purpose To compare the diagnostic performance and inter-observer agreement of five different CT chest severity scoring systems for COVID-19 to find the most precise one with the least interpretation time. Methods and materials This retrospective study included 85 patients (54 male and 31 female) with PCR-confirmed COVID-19. They underwent CT to assess the severity of pulmonary involvement. Three readers were asked to assess the pulmonary abnormalities and score the severity using five different systems, including chest CT severity score (CT-SS), chest CT score, total severity score (TSS), modified total severity score (m-TSS), and 3-level chest CT severity score. Time consumption on reporting of each system was calculated. Results Two hundred fifty-five observations were reported for each system. There was a statistically significant inter-observer agreement in assessing qualitative lung involvement using the m-TSS and the other four quantitative systems. The ROC curves revealed excellent and very good diagnostic accuracy for all systems when cutoff values for detection severe cases were > 22, > 17, > 12, and > 26 for CT-SS, chest CT score, TSS, and 3-level CT severity score. The AUC was very good (0.86), excellent (0.90), very good (0.89), and very good (0.86), respectively. Chest CT score showed the highest specificity (95.2%) in discrimination of severe cases. Time consumption on reporting was significantly different ( 3L-CT-SS > chest CT score > TSS. Conclusion All chest CT severity scoring systems in this study demonstrated excellent inter-observer agreement and reasonable performance to assess COVID-19 in relation to the clinical severity. CT-SS and TSS had the highest specificity and least time for interpretation. Key Points • All chest CT severity scoring systems discussed in this study revealed excellent inter-observer agreement and reasonable performance to assess COVID-19 in relation to the clinical severity. • Chest CT scoring system and TSS had the highest specificity. • Both TSS and m-TSS consumed the least time compared to the other three scoring systems. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08432-5.

Invasive mice (Mus spp.) can negatively impact island species and ecosystems. Because fewer island rodent eradications have been attempted for mice compared to rats (Rattus spp.), less is known about efficacy and palatability of rodenticide baits for mouse eradications. We performed a series of bait acceptance and efficacy cage trials using a standard formulation of brodifacoum-based rodenticide on wild-caught mice from Sand Island, Midway Atoll, to help inform a proposed eradication there. Mice were offered ad libitum brodifacoum pellets along with various alternative food sources, and a “no choice” treatment group received only bait pellets. Mortality in the no choice trial was 100%; however, when offered alternative foods, mice preferred the alternative diets to the bait, leading to low mortality (40%). Because there was concern that the bittering agent Bitrex® in the formulation may have reduced palatability, we conducted a subsequent trial comparing brodifacoum bait with and without Bitrex. Mortality in the with-Bitrex treatment group was slightly higher, indicating that the bittering agent was not likely responsible for low efficacy. Laboratory trials cannot account for the numerous environmental and behavioral factors that influence bait acceptance nor replicate the true availability of alternative food sources in the environment, so low efficacy results from these trials should be interpreted cautiously and not necessarily as a measure of the likelihood of success or failure of a proposed eradication.

The kinetochore is essential for faithful chromosome segregation during mitosis and is assembled through dynamic processes involving numerous kinetochore proteins. Various experimental strategies have been used to understand kinetochore assembly processes. Fluorescence recovery after photobleaching (FRAP) analysis is also a useful strategy for revealing the dynamics of kinetochore assembly. In this study, we introduced fluorescence protein-tagged kinetochore protein cDNAs into each endogenous locus and performed FRAP analyses in chicken DT40 cells. Centromeric protein (CENP)-C was highly mobile in interphase, but immobile during mitosis. CENP-C mutants lacking the CENP-A-binding domain became mobile during mitosis. In contrast to CENP-C, CENP-T and CENP-H were immobile during both interphase and mitosis. The mobility of Dsn1, which is a component of the Mis12 complex and directly binds to CENP-C, depended on CENP-C mobility during mitosis. Thus, our FRAP assays provide dynamic aspects of how the kinetochore is assembled.

The neuronally expressed developmentally downregulated 4 (NEDD4) gene encodes a ubiquitin ligase that targets the epithelial sodium channel for degradation and has been implicated in tumor growth in various cancers. Hence, in this study, we intended to characterize the functional relevance of the NEDD4-mediated Kruppel-like factor 8/microRNA-132/nuclear factor E2-related factor 2 (KLF8/miR-132/NRF2) axis in the development of bladder cancer. NEDD4 and KLF8 were overexpressed in bladder cancer tissues and were associated with poorer patient survival rates. In bladder cancer cells, NEDD4 intensified the stability and transcriptional activity of KLF8 through ubiquitination to augment cell viability and migratory ability. Our investigations revealed that NEDD4 promotes the binding of KLF8 to the miR-132 promoter region and inhibits the expression of miR-132. KLF8 inhibited the expression of miR-132 to augment the viability and migratory ability of bladder cancer cells. Furthermore, miR-132 downregulated the expression of NRF2 to restrict the viability and migratory ability of bladder cancer cells. In addition, in vivo findings verified that NEDD4 regulates the KLF8/miR-132/NRF2 axis by accelerating tumor growth and lung metastasis. In conclusion, this study highlights NEDD4 as a potential therapeutic target against tumor recurrence and metastasis in bladder cancer.

Pyrolysis gas chromatography-mass spectrometry is a useful technique for the analysis of complex organic matter. However, the pyrolysis temperatures must be carefully chosen to maximize the information obtained and, in parallel, minimize byproducts. One solution to accomplish this is the stepwise pyrolysis method, which has been employed to analyze complex mixtures of natural samples. Here, we compared the stepwise pyrolysis method to a suite of single-step pyrolysis runs using the same temperatures by employing a humic acid standard sample, to evaluate the advantage of the stepwise pyrolysis method. In addition, we conducted in-situ heating experiments of the humic acid under infrared microspectroscopy to observe changes in the functional groups during the stepwise pyrolysis process. Results showed that O-bearing components were released at relatively low temperatures, whereas aromatic components were released at higher temperatures, indicating that the stepwise method effectively separates labile and refractory fractions. As such, the stepwise method would be useful for analyzing limited amounts of samples, such as for extraterrestrial materials as well as for payload instruments onboard space missions.

The individual effects of strain rate and temperature on the strain hardening rate of a quenched and partitioned steel have been examined. During quasistatic tests, resistive heating was used to simulate the deformation-induced heating that occurs during high-strain-rate deformation, while the deformation-induced martensitic transformation was tracked by a combination of x-ray and electron backscatter diffraction. Unique work hardening rates under various thermal–mechanical conditions are discussed, based on the balance between the concurrent dislocation slip and transformation-induced plasticity deformation mechanisms. The diffraction and strain hardening data suggest that the imposed strain rate and temperature exhibited dissonant influences on the martensitic phase transformation. Increasing the strain rate appeared to enhance the martensitic transformation, while increasing the temperature suppressed the martensitic transformation.

Intraflagellar transport for ciliary assembly and maintenance is driven by dynein and kinesins specific for the cilia. It has been shown that anterograde and retrograde transports run on different regions of the doublet microtubule, i.e., separate train tracks. However, little is known about the regulatory mechanism of this selective process. Since the doublet microtubule is known to display specific post-translational modifications of tubulins, i.e. “tubulin code”, for molecular motor regulations, we investigated the motility of ciliary specific dynein-2 under different post-translational modification by coarse-grained molecular dynamics. Our setup allows us to simulate the stochastic stepping behaviors of dynein-2 on un-modified, detyrosinated, poly-glutamylated and poly-glycylated microtubules in silico. Our study revealed that poly-glutamylation can play an inhibitory effect on dynein-2 motility. Our result indicates that poly-glutamylation of the B-tubule of the doublet microtubule can be used as an efficient means to target retrograde intraflagellar transport onto the A-tubule.

Among the high-performance and engineering polymers, polyimides and the closely related polyetherimide (PEI) stand out by their capability to react with nucleophiles under relatively mild conditions. By targeting the phthalimide groups in the chain backbone, post-functionalization offers a pathway to adjust surface properties such as hydrophilicity, solvent resistance, and porosity. Here, we use ultrathin PEI films on a Langmuir trough as a model system to investigate the surface functionalization with ethylene diamine and tetrakis(4-aminophenyl)porphyrin as multivalent nucleophiles. By means of AFM, Raman spectroscopy, and interfacial rheology, we show that hydrolysis enhances the chemical and mechanical stability of ultrathin films and allows for the formation of EDC/NHS-activated esters. Direct amidation of PEI was achieved in the presence of a Lewis acid catalyst, resulting in free amine groups rather than cross-linking. When comparing amidation with hydrolysis, we find a greater influence of the latter on material properties. Graphic abstract

INTRODUCTION: Not only chronic but also some acute wounds have a risk of infection and become unhealed wounds. Silk-elastin sponge has been developed to treat chronic wounds that are susceptible to infection. Preclinical and clinical studies suggested that silk-elastin sponge is safe for humans and can promote granulation tissue formation by reducing bacterial growth in chronic wounds. The central aim of this trial is to evaluate the clinical utility and safety of silk-elastin sponge for the treatment of chronic and acute skin ulcers. METHODS: This study is a prospective, multicenter, single-arm, uncontrolled clinical trial. In this study, 20 patients with chronic ulcers and five with an acute one will be included; patients with wound infection will be excluded. Silk-elastin sponges are applied and covered with a dressing for 14days. PLANNED OUTCOMES: The primary endpoint is the frequency of patients with chronic wounds in whom the investigator confirms the formation of a healthy wound bed at 14days after the initial application of the study device. In addition, safety for acute wounds and handiness of the study device will be assessed. TRIAL REGISTRATION NUMBER: jRCT2052210072.

Spirulina sp. MCCABT-SP0001 was grown in a miniature raceway pond system: an innovative and low-cost cultivation method for extraction of the natural pigment C-Phycocyanin. The extractions of C-Phycocyanin from Spirulina sp. were carried out by three different methods and the extracted C-phycocyanin was estimated separately for each method. Among the different methods of extraction, Freezing and Thawing, Alum and 15 M HCl extraction showed the best results, i.e., 0.40 mg/ml, 0.21 mg/ml and 0.19 mg/ml respectively. The C-Phycocyanin was partially purified using Ammonium Sulphate precipitation and later dialysed. The molecular weight of the powdered C-Phycocyanin was determined using SDS-PAGE. The molecular weight of C-Phycocyanin was found to be α14 kDa and β15 kDa subunits. The partially purified C-Phycocyanin was investigated for HPLC to know the presence of vitamins, both qualitatively and quantitatively. The vitamins present in C-Phycocyanin were Niacin (8.7 mg/ml), Pyridoxine (0.38 mg/ml), Thiamine (0.434 mg/ml) and Riboflavin (0.11 mg/ml). The partially purified C-Phycocyanin was examined for its staining ability cum stability with boiled rice as a natural colourant. Our research analysis findings suggest that C-Phycocyanin can be used as an alternative to synthetic food colourants, with high nutritional values for better health.

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is scarce and usually presents as meningoencephalomyelitis. Here, we offer the case of an atypical presentation of GFAP-astrocytopathy. We report the case of a 26-year-old woman admitted to our neurology department for a 3-week progressive and worsening neurologic picture, with secondary worsening. Initial imaging showed a Mild Encephalitis with Reversible Splenium of corpus callosum lesion (MERS). Full infectious and autoimmune workup then revealed positivity of GFAP antibodies, leading us to diagnose GFAP astrocytopathy. Our case is the first reported association between MERS and GFAP astrocytopathy in an adult patient. Clinical presentation of GFAP astrocytopathy usually includes various neurologic symptoms and can lead to misdiagnosis.

The versatility of immobilized enzyme systems enables rapid recovery of both product and enzyme, numerous re-uses of enzymes, continuous enzymatic processes, quick reaction termination, and a wider range of bioreactor designs. Immobilized enzymes have been the topic of significant research because of their remarkable functional characteristics such as optimal nature, reusability, and cost-effectiveness. In addition to industrial operations, enzyme immobilization technology is also utilized as component technology in the food industry, biomaterial detection, medical diagnostics, bioenergy, and therapeutics. To demonstrate its important uses, several sorts of biosensors, such as enzyme-based biosensors, enzyme-based thermistors, electrochemical biosensors, optical biosensors, DNA biosensors, immunosensors, magnetic biosensors, and thermal biosensors have been debated here. A flexible and highly functioning enzyme is utilized for analyte identification by oxidizing enzymes such as peroxidases and polyphenol oxidize such as laccases and tyrosinases. These enzymes are therefore regarded as appealing and intriguing compounds for biosensors. New systems of reliable biosensor interfaces have gathered considerable interest in recent years. This study highlights key prospects, the newest technologies and materials utilized to build robust biosensor interfaces. These materials include polymers, nanomaterials and their composites i.e. nanocomposites were used for the designation of biosensors. This review studies recent advances in stability interface solutions for biosensors, which may give researchers some references and novel approaches to further investigate new materials and methodologies in biomedical applications.

In this work, the possibility of using corn straw to obtain carboxymethylcellulose (CMC) was verified. However, to obtain CMC from lignocellulosic residues, it is necessary to carry out initial treatments to reduce the levels of lignin and hemicellulose. In this context, studies have been conducted to enable the use of an ionic liquid (IL). The n-butylammonium acetate was used to treat the straw instead of the pulping stage for the subsequent attainment of CMC. For comparison, we determined the composition of the resulting material after the stages of NaOH pulping (NaP) or treatment with the IL (at 80 °C—ILP80 and 120 °C—ILP120) and bleaching, to analyze the purity of the cellulose obtained. It was also possible to verify that the treatment at 120 °C was more effective to remove inorganic materials and lignin, leading to cellulose with 91.45 ± 0.11% purity when compared with its treatment at 80 °C. CMC was successfully synthesized and presented similar morphologies accordingly. Consequently, the attainment of CMC was confirmed by analyzing the data obtained via FTIR, NMR, and XRD techniques, as well as the analyses of degree of substitution. It was also possible to recover the ionic liquid at a purity of 95.93%.

This work makes an investigation of Polyvinyl Alcohol (PVA)/Polyvinyl Pyrrolidone (PVP) composite scattered by copper oxide nanoparticles. Spectroscopic techniques have been utilized for studying the mechanism of the reaction between PVA/PVP and CuO NPs. Cell viability and antibacterial assessment are used for investigating the antibacterial activity of nanocomposite systems. XRD and FTIR-ATR approved the complexation and miscibility between PVA, PVP, and CuO NPs UV–Vis spectra approved the embedding of CuO NPs into PVA/PVP by the appearance of an additional peak at 336 nm. Optical parameters and bandgap calculation indicate that CuO NPs decrease the crystallinity of the nanocomposite system. DSC measurements were also studied to reveal the thermal stability of the prepared sample. The inhibition zone values of E. coli and S. aureus microorganisms increased by increasing the CuO NPs ratio in PVA/PVP to 18.5 ± 0.5 and 20.4 ± 6.0. The responses of the fibroblast cell line to the synthesized nanocomposites showed the capacity of PVA/PVP/CuO NPs nanocomposite to be recommended for biomedical applications.

Eri silkworm (Samia cynthia ricini) is the multivoltine non-mulberry silkworm that could be cultured indoors for silk production. It has been reported that the quality of silk varies with species of silkworms and the host plants. However, the cause of quality variance in silk protein is yet to be unfolded. On this background, the present work has been designed to study the histological structure and protein profile of the silk gland and cocoon of S. c. ricini. The cellular structure of the silk gland has been studied histologically using the routine eosin-haematoxylin staining method. Silk gland and cocoon protein profile has been studied by discontinuous SDS-PAGE followed by Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The results showed that the silk gland is formed by monolayer epithelial cells. The protein globules secreted from the posterior part of the gland coalesce in the lumen. The nuclei are highly convoluted in the middle and posterior silk glands in the day 01 wandering larvae for pupation. Study of protein profile by SDS-PAGE showed 36 protein bands in the whole silk gland and cocoon. LC-MS/MS analysis showed the presence of 109 protein molecules in the silk gland. These include Fibroin heavy chain, Fibrohexamerin (P25), Sericin 1 and Sericin 2. Sericin 3 was not identified in the whole silk gland and cocoon. This study will contribute data for the evolutionary study, biomaterial applications, and genetic engineering, to study the impacts of food plants, environmental parameters, and toxicity of pesticide residues on the silk gland in further studies.

Optimizing the release density and size of juvenile commercial species for local ecosystems is a critical issue that should be considered when countering predation impacts. To ascertain whether mariculture production of the Japanese scallop (Mizuhopecten yessoensis) could be enhanced by modifying releasing practices, we experimentally investigated the effects of density and size of scallop seeds on their survival in the presence of two sea star species, Asterias amurensis and Distolasterias nipon, with different predation capacities. Under current mariculture practices, the juveniles are briefly exposed to air just before release; therefore, we also examined how air exposure stress increased the predation risk. Scallop survival in the presence of both sea stars increased by > 20% by increasing scallop size from 30 to 50 mm. Increasing scallop density (range: 5 to 30 scallops m−2) increased each individual’s survival in the presence of A. amurensis but had no significant effect on predation by D. nipon. Therefore, the release of smaller quantities of large-sized scallops rather than larger quantities of small scallops is recommended to reduce D. nipon predation. In the presence of sea stars, especially by D. nipon, the predation impact on small scallops increased after just a few hours of air exposure, indicating that air exposure of juvenile scallops should be minimized. Our results will mitigate the economic cost of mariculture by facilitating the determination of optimal release conditions for juvenile scallops.

The flexible hydrogel sensors in the field of artificial intelligence have been widely concerned, which could be applied in medical monitoring, human motion detection, and intelligent robots. However, the integration of the synergistic properties of excellent mechanical properties, temperature sensitivity, adhesion ability and self-healing ability for preparation of hydrogel-type strain sensor is still a challenge. Moreover, how can we recover cumulated sensors without affecting the environment? Herein, a self-healing hydrogel was prepared based on deep eutectic solvent (DES) combined with polyvinyl alcohol (PVA), and cellulose nanocrystals (CNCs), which has the peotential application as wearable strain sensors. The DES network crosslinks PVA/CMC-Na/CNCs through ionic bonds, and the overall network is further linked through physical entanglement and hydrogen bonding interactions. Interestingly, the hydrogel could sensitively detect large or subtle movements (such as finger bending, wrist bending, knee bending, pulse and pronounce), indicating its potential applications in human–computer interaction and personal health monitoring.

Foot rot, also known as stem rot or tuber-root rot syndrome, on sweet potato occurs in sweet potato fields in Okinawa, Japan. Isolates of one fungal species that was consistently isolated from affected sweet potato produced pycnidia having alpha and gamma conidia. The same symptoms as those in the field were produced in vitro after inoculation of test plants with a representative isolate. Based on morphological and molecular phylogenetic evidence, we identified the fungus as Diaporthe destruens. This is the first report of the occurrence of foot rot on sweet potato caused by D. destruens in Japan.

Currently propeller boss cap fin (PBCF) and propeller duct are among the well-known energy saving devices (ESD) for their effectiveness in recovery of energy losses during practical operation. These two devises prominently reduce the hub vortex as well tip vortex and hence improve propeller efficiency. Combined study of PBCF and propeller duct has become important and is essential to observe their impact in propeller efficiency. Here, numerically the importance of duct angle of attack and duct position in a ducted propeller in the presence of PBCF has been investigated to improve the overall efficiency. Five different angles of attack (0°, 2.5°, 5°, 7.5°, 10°) with 2.5° interval and five different positions (0.1, 0.15 m before propeller, at the propeller, 0.1, 0.15 m after the propeller) of duct have been considered to investigate the overall efficiency in the presence of both ESDs. Reynolds Average Navier Stokes (RANS) equations are utilized for numerical simulation in moving reference frame (MRF) approach. The simulations reveal that a maximum improvement of 7.05% is obtained in propeller efficiency at 0° angle of attack and it proportionally reduces with the increase in angle of attack. It is also observed that duct placed before propeller produced a maximum enhancement in efficiency of about 9.86% in comparison with other duct positions. Variation of pressure coefficient, vortices, skin friction coefficient and turbulence kinetic energy are also studied in detail in order to have a better understanding about the flow behaviour.

Finding novel systems for controlled delivery of drugs is still a stringent need. Fabrication of drug delivery systems (DDS) having a cross-linked low molar mass synthetic polycation such as poly(ethylene imine) (PEI) entrapped into the pores of a mesoporous silica followed by coating the silica/PEI composite microspheres with a pH responsive layer-by-layer (LbL) film is presented for the first time in this work. The LbL film, which behaves as drug release lingering component of the composite, was constructed with carboxymethyl cellulose (CMC) and chitosan (CS) as building blocks. Silica/PEI/(CMC/CS)n composites were fully characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and EDX spectra, and by the nitrogen sorption/desorption isotherms (BET analysis). The dynamic of LbL film construction was followed by potentiometric and polyelectrolytic titrations. Diclofenac sodium (DS) was used as a model drug to demonstrate the potential of the as prepared composite as novel system for controlling the release of drugs. Investigation of the release kinetics evidenced the influence of the LbL film on the mechanism of DS release. Taking into account the values of nr in the Korsmeyer-Peppas equation, pseudo-Fickian release, with nr

The “stress-shielding” problem, common with metallic implants, may be solved by using biocompatible sandwiches with a polymeric core between two metallic skin sheets. To achieve such sandwiches, a process route has been developed, beginning with the grafting of poly-(methyl-methacrylate) (PMMA) on titanium (Ti) sheets via the “grafting from” technique. Grafting resulted in variable thicknesses of PMMA on the Ti sheets. Hot-pressing was used to prepare semi-finished Ti–PMMA–Ti sandwiches. The adhesion was achieved by the interpenetration between PMMA sheet and the grafted PMMA chains. Investigation was carried out to understand the influence of the grafted PMMA thickness on the adhesion strength. Similar adhesion strengths were found for the sandwiches despite variable grafted PMMA thicknesses, indicating a successful grafting of PMMA on large-scale Ti sheets. The adhesion followed the autohesion theory, where a time-dependent increase in adhesion strength was found for the sandwiches.

Burns are one of the most prevalent and harmful types of trauma. Patients with critical thermal harm need immediate specialized care to minimize morbidity and mortality. This study aimed to assess the curing possibility of chitosan/guar gum/Aloe Vera hydrogel on the curing of full-thickness burn wounds in the Wistar albino model. Two full-thickness burn wounds were formed on the dorsum of each rat under general anesthesia. Burn wounds were cured with chitosan gel; chitosan/guar gum hydrogel; chitosan/Aloe Vera hydrogel; chitosan/guar gum/Aloe Vera hydrogel, respectively. Healing was investigated based on the percentage of wound shrinkage, and surface area as well as histopathological and histomorphological observations. A significant decrease in the wound area and the epithelial gap was noticed in all groups, especially the wounds treated with chitosan/guar gum. Maximum angiogenesis was observed in the chitosan/Aloe Vera treated group. Chitosan/guar gum/Aloe Vera treated wounds demonstrated an enhancement in the thickness and integrity of collagen fibers and the highest score among fibroblast cells accumulation. Furthermore, the inflammatory cellular response and hyperemia were significantly higher in the control group when compared with those of other chitosan-based groups. Chitosan/guar gum/Aloe Vera hydrogel has a curing possibility and has presented the best healing result compared to other treatments for the restoration of full-thickness skin burn wounds in rats.

Innovation of high-value added lignin derivatives has become a topic of interest, but lignin modification and utilization remain a challenge due to lignin’s complicated structure. In our previous study, we successfully improved water resistance and adhesion performance of soy protein adhesives using unmodified lignin. This study focuses on lignin modification as well as lignin-protein properties and interactions. Lignin modification was achieved by pH changes and pH-shifting. Cleavage of β-O-4 linkage was observed at pH 8.5 and pH 12, resulting in smaller particle sizes and changes in thermal properties. Partial repolymerization was found after pH-shifting treatments. Lignin increased the strength of protein films under high temperature and significantly enhanced the water resistance of soy protein at pH 12. Cross-linking of protein and lignin took place via carbonyl, amino, and hydroxyl groups. Multiple-point interactions between lignin and protein resulted in a stronger lignin-protein network. Additional lignin-protein complexes with high molecular weight were detected with an elevated lignin concentration at pH 8.5. The binding interaction between lignin and protein, although of non-specific nature, was also observed by isothermal titration calorimetry (ITC). Findings of this study contribute to the further development of green lignin-protein products.

Scaffolds made with hydroxyapatite (HAp), polylactic acid (PLA), and commercial polycaprolactone (PCL) were developed. HAp was synthesized by the wet chemical precipitation method, while semicrystalline PLA was obtained by a monomer ring-opening polymerization, displacing air with helium gas. This synthesis modification has not been described previously. Subsequently, by solvent casting/salt leaching, both compositions of the scaffolds were designed: HAp10-PLA10-PCL80 and HAp30-PLA10-PCL60. DSC/TGA. SEM, XRD, and FTIR were characterized. The overall results illustrate that scaffolds of these compounds display satisfactory morphology and thermal properties.

The acetylation of xylan has a great influence on the physiology of plants and the properties of lignified tissues. However, the effect of acetylation on the crystallization of xylans is still unclear. In this study, homogeneous acetylation of deacetylated β-(1–4)-d-xylans to different degree of substitution (DS) was carried out. Two precipitation methods, i.e. ethanol and water, were used to precipitate acetylated xylans. With the assistance of perpropionylation and HMBC NMR spectra, the DS of acetylation was accurately determined. The crystallization properties of acetylated xylans at different DS were evaluated by X-ray diffraction. For ethanol precipitated acetylated xylans, it is amorphous at all DS except at DS = 2 showing diffraction peaks of xylan diacetate crystal. For water precipitated acetylated xylans, it shows diffraction peaks of xylan hydrate crystal between DS 0 and DS 0.6, while the appearance of xylan diacetate crystal peaks starts at DS 1.96. The forming of xylan diacetate crystal is very abrupt with the changes of DS.

Melamine was grafted to a polyurethane (PU) frame and utilized for cross-linking PU via amino groups. The degree of crosslinking and the solution viscosity increased notably after grafting melamine due to the formation of crosslinks. The thermal transition of the soft segment was not significantly affected, but the glass transition was observed at a slightly higher temperature in case of the grafted melamine. Melamine-mediated crosslinking increased not only the breaking tensile stress but also the shape recovery performance of PU. In addition, crosslinked PU was more flexible at low temperature than unmodified PU. Overall, melamine-mediated crosslinking improved the tensile resistance to stress, the recovery tendency to the initial shape, and the flexibility with minor changes in the thermal transition, tensile strain, and shape retention at a low temperature.

A new bio-sourced adhesive system is presented based on urea crosslinked glyoxalated lignin and dialdehyde starch obtained by hydrogen peroxide oxidation of starch. The molecular species formed and the reactions mechanism involved were identified by FTIR, 13C NMR, and MALDI-ToF mass spectrometry. Urea appears to react with both, glyoxalated lignin and dialdehyde starch. The adhesives based on this reaction were tested by means of laboratory particleboards, differential scanning calorimetry (DSC), and thermomechanical analysis (TMA). The results obtained for internal bond (IB) strength with this adhesive system are acceptable for producing particleboard according to the relevant European standards. Additionally, chemical crosslinking by using 5% on resin solids of partially bio-sourced glycerol glycidyl ether (GDE) improves the bonding strength of the resins so formed; the main crosslinking sites were also determined.

From 2014 to 2018, we performed three on-site eradication actions of Poa annua occurring on King George Island. We aimed at (1) assessing the population response to eradication efforts, (2) evaluating the campaign success, and (3) identifying the most important factors likely to influence eradication success. The first partial eradication action reduced the initial population of around 1500 tussocks to around 1100 tussocks with less than 4 m2 canopy area. In treated locations, we observed high re-establishment where no soil removal was performed, while only a marginal recruitment where plants were removed with associated soil. In the 2017/2018 season, we recorded over 1800 tussocks, which all were subsequently removed. Performing eradication according to the prescribed scheme (plant and soil removal) should result in eradication success. We evaluate that the probability of successful eradication of the population is high because of small size and number of separate infestation sites, complete spatial and ecological isolation of infestation, high accessibility of target population, and well-known current location of infestation sites. The factors which reduce the likelihood of eradication success are long reaction time, high adaptation of the species to new environmental conditions, and high propagule longevity. Reinvasion possibility and frequent personnel changes in the eradication team resulting in varying levels of personnel awareness and experience may also negatively influence eradication success. An invasion, not managed for many years, may still be targeted, but its successful eradication depends on the “human factor”, which may drive the success of the action in opposing directions.

Oligo(hydroxypropyl)-substituted polysaccharides can be chemoselectively oxidized to introduce ketone groups at the termini of the side chains. These ketone-substituted polysaccharides, including oxidized hydroxypropyl cellulose, have been shown to be suitable components for preparation of in situ forming, all-polysaccharide hydrogels where chitosan is the reactive partner. This class of hydrogels exhibits several advantages including injectability, the ability to self-heal, and the absence of small molecule crosslinkers, therefore they have considerable promise for biomedical applications. Their strong potential inspires us to broaden the range of their application to include thermoresponsive hydrogels. Herein, we design and prepare a series of oxidized hydroxypropyl cellulose hydrogels by reaction with Jeffamines. Jeffamines themselves are polyethylene oxide-b-polypropylene oxide-b-polyethylene oxide triblock copolymers with two terminal amines. They display thermal responsivity, and are biocompatible with some tissues and under some circumstances. The mechanical properties of these Jeffamine/oxidized hydroxypropyl cellulose hydrogels were characterized by rheometry, revealing that hydrogel storage modulus could be tuned (3, 300–21, 000 Pa) by controlling temperature (25–60 °C) and Jeffamine chain length (600, 900, 1900 g/mol). Furthermore, these hydrogels display self-healing properties and high swelling ratios. Hydrogel microstructures were characterized by scanning electron microscopy. We investigated the potential for drug incorporation into the hydrogels. Overall, this study demonstrated synthesis and potential of these Jeffamine/oxidized hydroxypropyl cellulose hydrogels for in situ formation and thermally responsive behavior, thereby broadening the family of oxidized hydroxypropyl cellulose-based hydrogels.