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Science Advances Jun 2024The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of...
The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.
Topics: Netrin-1; Exosomes; Nerve Regeneration; Animals; Endothelial Cells; Peripheral Nerve Injuries; Mice; Neovascularization, Physiologic; Signal Transduction; Humans; Peripheral Nerves
PubMed: 38941462
DOI: 10.1126/sciadv.adm8454 -
ACS Applied Materials & Interfaces Jun 2024In this work, we present a series of nanocomposites for Fused filament fabrication (FFF) based on polycaprolactone (PCL) and chitin nanocrystals (ChNCs). The ChNCs were...
In this work, we present a series of nanocomposites for Fused filament fabrication (FFF) based on polycaprolactone (PCL) and chitin nanocrystals (ChNCs). The ChNCs were synthesized by acid hydrolysis using HCl or lactic acid (LA). The approach using LA, an organic acid, makes the ChNCs synthesis more sustainable and modifies their surface with lactate groups, increasing their compatibility with the PCL matrix. The ChNCs characterization by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy revealed that both ChNCs presented similar morphologies and crystallinity, while differential scanning calorimetry and thermogravimetric analysis proved that they can bear temperatures up to 210 °C without degrading, which allows their processing in the manufacturing of PCL composites by twin-screw extrusion. Therefore, PCL composites in the form of filaments containing 0.5-1.0 wt % ChNCs were produced and used as feedstock in FFF, and standard tensile and flexural specimens were printed at different temperatures, up to 170 °C, to assess the influence of the ChNCs in the mechanical properties of the material. The tensile testing results showed that the presence of ChNCs enhances the strength and ductility of the PCL matrix, increasing the elongation at break around 20-50%. Moreover, the vertically printed flexural specimens showed a very different bending behavior, such that the pure PCL specimens presented a brittle fracture at 7% strain, while the ChNCs composites were able to bend over themselves. Hence, this work proves that the presence of ChNCs aims to improve the interlayer adhesion of the objects manufactured by FFF due to their good adhesive properties, which is currently a concern for the scientific community and the industrial sector.
PubMed: 38941240
DOI: 10.1021/acsami.4c06358 -
Molecular Neurobiology Jun 2024Brain-specific angiogenesis inhibitor 1 (BAI1) belongs to the adhesion G-protein-coupled receptors, which exhibit large multi-domain extracellular N termini that mediate...
Brain-specific angiogenesis inhibitor 1 (BAI1) belongs to the adhesion G-protein-coupled receptors, which exhibit large multi-domain extracellular N termini that mediate cell-cell and cell-matrix interactions. To explore the existence of BAI1 isoforms, we queried genomic datasets for markers of active chromatin and new transcript variants in the ADGRB1 (adhesion G-protein-coupled receptor B1) gene. Two major types of mRNAs were identified in human/mouse brain, those with a start codon in exon 2 encoding a full-length protein of a predicted size of 173.5/173.3 kDa and shorter transcripts starting from alternative exons at the intron 17/exon 18 boundary with new or exon 19 start codons, predicting two shorter isoforms of 76.9/76.4 and 70.8/70.5 kDa, respectively. Immunoblots on wild-type and Adgrb1 exon 2-deleted mice, reverse transcription PCR, and promoter-luciferase reporter assay confirmed that the shorter isoforms originate from an alternative promoter in intron 17. The shorter BAI1 isoforms lack most of the N terminus and are very close in structure to the truncated BAI1 isoform generated through GPS processing from the full-length receptor. The cleaved BAI1 isoform has a 19 amino acid extracellular stalk that may serve as a receptor agonist, while the alternative transcripts generate BAI1 isoforms with extracellular N termini of 5 or 60 amino acids. Further studies are warranted to compare the functions of these isoforms and examine the distinct roles they play in different tissues and cell types.
PubMed: 38941066
DOI: 10.1007/s12035-024-04293-3 -
Clinical Oral Investigations Jun 2024Evaluate the efficacy of denture cleaners on the adhesion of Candida albicans and their effects on the surface, optical, and mechanical properties of resins for...
OBJECTIVES
Evaluate the efficacy of denture cleaners on the adhesion of Candida albicans and their effects on the surface, optical, and mechanical properties of resins for conventional, milled, and 3D-printed denture bases.
MATERIALS AND METHODS
A total of 240 resin samples were made, 120 for testing Candida albicans adhesion, optical stabilities (ΔE), roughness (Ra), hydrophilicity (°), surface free energy (Owens-Wendt) and 120 samples for testing Candida albicans adhesion, surface microhardness (Knoop), flexural strength and modulus of elasticity in a three-point test, in which they were divided into 3 groups of denture resin (n = 40) and subdivided into 5 cleaners of dentures (n = 8). Data were evaluated by two-way ANOVA and Tukey's test for multiple comparisons (α = 0.05).
RESULTS
Denture cleaners with an alkaline solution and dilute acid composition were those that showed the greatest effectiveness in reducing Candida albicans (P < 0.001), however 1% NaOCl significantly affected the properties of the resins (P < 0.05). Denture 3D-printed showed that the surface microhardness was significantly lower for all cleansers (P < 0.05).
CONCLUSIONS
Listerine demonstrated superior efficacy in reducing Candida albicans with minimal effect on denture properties, whereas 1% NaOCl had a significant negative impact on the properties. The mechanical properties were significantly lower in 3D-printed resin than in other resins for all denture cleansers.
CLINICAL RELEVANCE
Denture base materials are being sold to adapt to the CAD/CAM system, increasing the number of users of dentures manufactured with this system. Despite this, there is little investigation into denture cleaners regarding the adhesion capacity of microorganisms and the optical, surface and mechanical properties of dentures, thus requiring further investigation.
Topics: Candida albicans; Denture Bases; Denture Cleansers; Surface Properties; Printing, Three-Dimensional; Materials Testing; Computer-Aided Design; Hardness; Flexural Strength; Dental Materials
PubMed: 38940942
DOI: 10.1007/s00784-024-05801-4 -
Archives of Gynecology and Obstetrics Jun 2024Dense adhesion due to severe endometriosis between the posterior cervical peritoneum and the anterior sigmoid or rectum obliterates the cul-de-sac and distorts normal...
BACKGROUND
Dense adhesion due to severe endometriosis between the posterior cervical peritoneum and the anterior sigmoid or rectum obliterates the cul-de-sac and distorts normal anatomic landmarks. Surgery for endometriosis is associated with severe complications, including ureteral and rectal injuries, as well as voiding dysfunction. It is important to develop the retroperitoneal avascular space based on precise anatomical landmarks to minimize the risk of ureteral, rectal, and hypogastric nerve injuries. We herein report the anatomical highlights and standardized and reproducible surgical steps of total laparoscopic hysterectomy for posterior cul-de-sac obliteration.
OPERATIVE TECHNIQUE
We approach the patient with posterior cul-de-sac obliteration using the following five steps. Step 1: Preparation (Mobilization of the sigmoid colon and bladder separation from the uterus). Step 2: Development of the lateral pararectal space and identification of the ureter. Step 3: Isolation of the ureter. Step 4: Development of the medial pararectal space and separation of the hypogastric nerve plane. Step 5: Reopening of the pouch of Douglas.
CONCLUSION
Surgeons should recognize the importance of developing the retroperitoneal avascular space based on precise anatomical landmarks, and each surgical step must be reproducible.
PubMed: 38940845
DOI: 10.1007/s00404-024-07614-y -
Dalton Transactions (Cambridge, England... Jun 2024The extraction and recovery of valuable metals from various spent catalysts bioleaching represents a green, low-carbon and eco-friendly process. However, the pulp...
The extraction and recovery of valuable metals from various spent catalysts bioleaching represents a green, low-carbon and eco-friendly process. However, the pulp density of spent catalysts is usually 1.0% or lower owing to their toxicity, denoting low process capacity and poor practical potential. In this study, an intensified bioleaching strategy was used for the first time to promote the release efficiencies of both Co and Mo from a spent Co-Mo catalyst at a high pulp density of 10% by supplementing extracellular polymeric substances (EPSs). The results showed that the addition of 0.6 g L EPSs harvested a maximum release of 73.6% for Co and 72.5% for Mo after 9 days of contact, with an evident elevation of 22.6% for Co and 24.4% for Mo, in contrast to no addition, respectively. The added EPS not only promoted the growth of plankton cells to produce more active molecules but also boosted the adhesion of leaching cells to the spent catalyst to form stable aggregates. Moreover, the resulting aggregates allowed for the gathering and confinement of the active small molecules, including Fe and Fe, inside the micro-areas between the spent catalysts and the cells for quick electronic transfer as an interface oxidation/reduction reaction to free both Co and Mo from the spent catalyst.
PubMed: 38940617
DOI: 10.1039/d4dt00104d -
MSphere Jun 2024, a cosmopolitan diatom primarily inhabiting coastal ecosystems, exhibits a typically close yet variable relationship with heterotrophic bacteria. The increasing...
UNLABELLED
, a cosmopolitan diatom primarily inhabiting coastal ecosystems, exhibits a typically close yet variable relationship with heterotrophic bacteria. The increasing temperature of surface seawater is expected to substantially affect the viability and ecological dynamics of , potentially altering its relationship with bacteria. However, it remains unclear to what extent the elevated temperature could change these relationships. Here, the relationship between axenic and natural seawater bacteria underwent a dramatic shift from mutualism to antagonism as the co-culture temperature increased from 20°C to 25°C. The co-occurrence network indicated significantly increased complexity of interaction between and bacteria community after temperature elevation, especially with , implying their potential role in eliminating under higher temperatures. Additionally, a isolate, namely MS1 identified as genus, was isolated from the co-culture system at 25°C. MS1 had a remarkable ability to eliminate , with the mortality rate at 25°C steadily rising from 30.2% at 48 h to 92.4% at 120 h. However, it promoted algal growth to some extent at 20°C. These results demonstrated that increased temperature promotes MS1 shifts from mutualism to antagonism with . According to the comparative genomics analysis, changes in the lifestyle of MS1 were attributed to the increased gliding motility and attachment of MS1 under elevated temperature, enabling it to exert an algicidal effect through direct contact with alga. This investigation provided an advanced understanding of interactions between phytoplankton and bacteria in future warming oceanic ecosystems.
IMPORTANCE
Ocean warming profoundly influences the growth and metabolism of phytoplankton and bacteria, thereby significantly reshaping their interactions. Previous studies have shown that warming can change bacterial lifestyle from mutualism to antagonism with phytoplankton, but the underlying mechanism remains unclear. In this study, we found that high temperature promotes sp. MS1 adhesion to , leading to algal lysis through direct contact, demonstrating a transition in lifestyle from mutualism to antagonism with increasing temperature. Furthermore, the gliding motility of MS1 appears to be pivotal in mediating the transition of its lifestyle. These findings not only advance our understanding of the phytoplankton-bacteria relationship under ocean warming but also offer valuable insights for predicting the impact of warming on phytoplankton carbon sequestration.
PubMed: 38940599
DOI: 10.1128/msphere.00198-24 -
Small (Weinheim An Der Bergstrasse,... Jun 2024Droplet-based electricity generators (DEGs) are increasingly recognized for their potential in converting renewable energy sources. This study explores the interplay of...
Droplet-based electricity generators (DEGs) are increasingly recognized for their potential in converting renewable energy sources. This study explores the interplay of surface hydrophobicity and stickiness in improving DEG efficiency. It find that the high-performance C-WaxDEGs leverage both these properties. Specifically, DEGs incorporating polydimethylsiloxane (PDMS) with carnauba wax (C-wax) exhibit increased output as surface stickiness decreases. Through experimental comparisons, PDMS with 1wt.% C-wax demonstrated a significant power output increase from 0.07 to 1.2 W m , which attribute to the minimized adhesion between water molecules and the polymer surface, achieved by embedding C-wax into PDMS surface to form microstructures. This improvement in DEG performance is notable even among samples with similar surface potentials and contact angles, suggesting that C-wax's primary contribution is in reducing surface stickiness rather than altering other surface properties. The further investigations into the C-WaxDEG variant with 1wt.% C-wax PDMS uncover its potential as a sensor for water quality parameters such as temperature, pH, and heavy metal ion concentration. These findings open avenues for the integration of C-WaxDEGs into flexible electronic devices aimed at environmental monitoring.
PubMed: 38940416
DOI: 10.1002/smll.202402765 -
Journal of Cell Science Jun 2024Desmosomes are relatives of ancient cadherin-based junctions, which emerged late in evolution to ensure the structural integrity of vertebrate tissues by coupling the... (Review)
Review
Desmosomes are relatives of ancient cadherin-based junctions, which emerged late in evolution to ensure the structural integrity of vertebrate tissues by coupling the intermediate filament cytoskeleton to cell-cell junctions. Their ability to dynamically counter the contractile forces generated by actin-associated adherens junctions is particularly important in tissues under high mechanical stress, such as the skin and heart. Much more than the simple cellular 'spot welds' depicted in textbooks, desmosomes are in fact dynamic structures that can sense and respond to changes in their mechanical environment and external stressors like ultraviolet light and pathogens. These environmental signals are transmitted intracellularly via desmosome-dependent mechanochemical pathways that drive the physiological processes of morphogenesis and differentiation. This Cell Science at a Glance article and the accompanying poster review desmosome structure and assembly, highlight recent insights into how desmosomes integrate chemical and mechanical signaling in the epidermis, and discuss desmosomes as targets in human disease.
Topics: Desmosomes; Humans; Animals; Epidermis
PubMed: 38940346
DOI: 10.1242/jcs.261899 -
Journal of Pediatric Ophthalmology and... Jun 2024To observe postoperative histological changes in the anterior part of the posterior fixation suture after a Faden operation in an animal model.
PURPOSE
To observe postoperative histological changes in the anterior part of the posterior fixation suture after a Faden operation in an animal model.
METHODS
A posterior fixation suture was placed at two points 6 mm posterior to the insertion of the extraocular muscle on the superior rectus muscle of the right eye in eight rabbits. The superior rectus muscle of the left eye was used as a control. The eyes were enucleated and the anterior portion of the posterior fixation suture, including the myoscleral junction, was extracted 4 weeks after surgery. Postoperative adhesion was graded from 0 to 4 based on histologic findings (hematoxylin-eosin and Masson's trichrome staining).
RESULTS
Histological evaluation revealed diffuse fibrosis at the myoscleral junction and the anterior part of the posterior fixation suture after the Faden operation. The graded scores for fibrosis, acute inflammation, chronic inflammation, and foreign body reactions in the Faden operation group were significantly higher than those in the control group ( < .05). Postoperative diffuse fibrosis of the myoscleral junction and anterior-to-posterior fixation sutures were observed in an animal model.
CONCLUSIONS
Histologic changes may affect ocular alignment and motility, making reoperation unpredictable after the Faden procedure. .
PubMed: 38940304
DOI: 10.3928/01913913-20240521-04