Coated Samples Research Articles

Failure of vinyl coatings under alternating hydraulic pressure

To investigate the effects of substrate surface roughness and alternating pressure on the bonding strength between the vinyl anti-corrosion coating and the substrate, several coated samples were prepared using 304 stainless steel substrate to carry out alternating hydraulic pressure tests. The surface morphology of the coating and substrate, as well as the surface roughness of the substrate, were examined using a laser confocal microscope and a three-dimensional surface profiler. The alternating hydraulic pressure test was conducted inside an autoclave, and the bonding strength was measured using the double-test column method. The results show that the bonding strength of the coating increases with substrate roughness, with a more pronounced effect when the roughness is less than 1 μm. When the roughness increased from 0.189 µm to 0.85 µm, the bond strength of the coating without vacuum treatment increased from 4.97 MPa to 7.07 MPa; further increasing the roughness to 1.251 μm resulted in a bond strength of 7.92 MPa. During the preparation phase, vacuum treatment effectively eliminated internal bubbles and micro-defects within the coating, significantly enhancing the bond strength by 4 to 5 MPa. The alternating pressure causes cracks on the surface of the coating and further accelerates the failure of the protective effect of the coating. After 180 cycles of alternating hydraulic pressure tests, the bonding strength of the coating without vacuum treatment decreased by 43.3% from 6.99 MPa to 3.96 MPa. In contrast, the bonding strength of the vacuum-treated coating decreased by only 18.6% from 11.77 MPa to 9.58 MPa. The increase in coating thickness is related to the accumulation of water penetration and corrosion products at the substrate-coating interface.

Efficacy of amniotic fluid, blood and urine samples for the diagnosis of toxoplasmosis in pregnant women candidates for amniocentesis using serological and molecular techniques

BackgroundsToxoplasmosis, a prevalent parasitic infection, is primarily caused by Toxoplasma gondii (T. gondii). This infection poses a significant threat to neonates during pregnancy and individuals with compromised immune systems. Consequently, it is imperative to develop a novel diagnostic approach that combines high sensitivity with low-risk sampling to effectively manage patients. The aim of this study is to utilize serological and molecular techniques for the diagnosis of T. gondii infection in 100 pregnant women who were under the care of a gynecologist and were candidates for amniocentesis.MethodsDuring the 15-19th weeks of pregnancy, a total of 100 samples each of amniotic fluid, buffy coat, plasma, and urine simultaneously were collected from pregnant women candidates for amniocentesis in Mazandaran province, northern Iran. This study involved various assessments: (1) detecting anti-T. gondii IgM and IgG in plasma through chemiluminescence assay (2) determining IgG avidity in plasma using the Enzyme-linked immunosorbent assay technique (3) identifying of T. gondii DNA in amniotic fluid, buffy coat and urine by nested PCR (nPCR) and quantitative real-time PCR (qPCR) methods targeting the REP-529 gene, as well as genotyping using GRA6 target genes, and (4) assessing the sensitivity and specificity of the nPCR and qPCR tests.ResultsOut of 100 pregnant women screened, 70 were between the ages of 31 to 40 years old. Among them, 23 and 44 had one and two previous pregnancies. Additionally, 13 and 8 women had one and two history of abortions, respectively. Following serologic testing, 52% of the individuals were positive for T. gondii antibodies. Of these, 52 samples were positive for IgG antibodies, and one sample was positive for both IgG and IgM antibodies. Notably, all 52 cases with IgG positivity exhibited a high level of IgG avidity. Regarding the molecular testing of amniotic fluid samples, two pregnant women tested positive in the nPCR assay, while three tested positive in the qPCR assay. Furthermore, genotyping revealed that all positive samples belonged to type I of the T. gondii genotype. Moreover, none of the 100 buffy coat and urine samples tested positive for T. gondii using the nPCR and qPCR techniques.ConclusionThe findings of the current study suggest that serological methods alone may not be reliable in diagnosing congenital toxoplasmosis and cannot rule out the diagnosis of toxoplasmosis and must be approved by molecular tests.

Functional dynamics analysis of endophytic microbial communities during Amorphophallus muelleri seed maturation

Konjac seeds of Amorphophallus muelleri are produced through a unique form of apomixis in triploid parthenogenesis, and typically require a longer maturation period (approximately 8 months). To date, the relevant functions of endophytic microbial taxa during A. muelleri seed development and maturation remain largely unexplored. In this study, we analyzed the functional adaptability and temporal dynamics of endophytic microbial communities during three stages of A. muelleri seed maturation. Through metagenomic sequencing, we determined that the functions of the endophytic microbiome in A. muelleri seeds were driven by the seed maturation status, and the functions of the microbial communities in the seed coats and seeds differed significantly. The species annotation results show that Proteobacteria, Actinobacteria, Ascomycota, and Basidiomycota were the dominant bacterial and fungal communities in A. muelleri seeds at different maturation stages. The KEGG and COG functional gene annotation results revealed that the seed samples during the three maturation stages had higher KO functional diversity than the seed coat samples, and the COG functional diversity of the green and red seed samples was also significantly higher than that of the seed coat samples. At different maturation stages, microbial functional genes involved in energy production and conversion as well as carbon fixation were enriched in the A. muelleri seed coats, while microbial functional genes involved in signal transduction mechanisms, amino acid transport and metabolism, carbohydrate metabolism, and lipid metabolism were more highly expressed in the seeds. Moreover, in the middle to late stages of seed maturation, the microbial functional genes involved in the biosynthesis of resistant compounds such as phenols, flavonoids, and alkaloids were significantly enriched to enhance the resistance and environmental adaptation of A. muelleri seeds. The results verified that the functions of the endophytic microbial communities change dynamically during A. muelleri seed maturation to adapt to the current needs of the host plant, which has significant implications for the exploration and utilization of functional microbial resources in A. muelleri seeds.

Abstract A057: Cancer-induced epigenomic changes in circulating immune cells enable breast, colorectal and lung cancer detection

Abstract Background: Epigenomic changes via the measurement of 5-hydroxymethylation cytosine (5hmC) in DNA have been shown to enable detection in a variety of cancers including pancreatic and ovarian cancer in plasma-derived cell-free DNA (cfDNA). Here, we investigated whether blood-based 5hmC profiling of genomic DNA (gDNA) derived from cells of the buffy coat (BC) possess signals that enable the detection of breast, colorectal and lung cancers. Method: Blood samples collected in Streck tubes from cancer patients or non-cancer controls were processed to obtain buffy coat and plasma samples. gDNA and cfDNA was isolated from buffy coat and plasma, respectively. gDNA or cfDNA was then subjected to 5hmC enrichment by click chemistry followed by preparation of sequencing libraries. Sequencing was performed to obtain genome-wide 5hmC profiles of buffy coat gDNA and cfDNA samples. Results: Differential hydroxymethylation analysis of BC gDNA revealed increased 5hmC over genes associated with myeloid lineage in breast, colorectal and lung cancers relative to non-cancer controls. Flow cytometry analysis confirmed increases in myeloid cells in cancer samples relative to non-cancer controls. 5hmC patterns in BC gDNA showed a larger number of cancer-associated changes compared to cfDNA, in particular this was found in early-stage disease. 5hmC features from BC gDNA or plasma-derived cfDNA were used to build prediction models that yielded cancer classification with overall sensitivity of 51.3% and 52.6% at 98% specificity, for BC or cfDNA, respectively. For early-stage cancer, the sensitivity at 98% specificity was 46.5% for the BC and 28.2% for cfDNA model. A final prediction model incorporating features from both tissue sources achieved superior classification (65.8% sensitivity) at 98% specificity, compared with using features from either tissue source alone, particularly for early-stage cancer which achieved 53.5% sensitivity of cancer detection. Conclusion: Our results demonstrate that cancer impacts the 5hmC profiles of buffy coat cells which can be leveraged for cancer detection using blood. Citation Format: Gulfem D Guler, Giuliana P Mognol, Yuhong Ning, Carolina Fraire, David Haan, Michael Kesling, Roger Malta, Melissa Peters, Anna Bergamaschi, Tierney Phillips, Shimul Chowdhury, Wayne Volkmuth, Samuel Levy. Cancer-induced epigenomic changes in circulating immune cells enable breast, colorectal and lung cancer detection [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A057.

Abstract A013: Quality control of the biobanked matched tissue: Blood samples for the development of diverse liquid based molecular assays

Abstract The availability of high-quality matched biological samples (tumor-blood) is the major limiting factor for research and development of novel, liquid biopsy-based assays in oncology. Frequently, ongoing specifically timed collections of blood samples are required. De-identified tissue blocks (formalin-fixed, paraffin embedded (FFPE) or flash frozen) matched with patient's blood samples collected in fixative-containing (Streck) of EDTA containing tubes, were collected at worldwide geographic locations and transferred to biobanking facility (Reference Medicine, Phoenix, AZ). Additional blood samples were collected at various times regarding the cancer surgery. Plasma and buffy coat samples were locally prepared and shipped to the biobank. A subset of blood samples without matched tissues from healthy donors were also collected. All samples were shipped under strict transport conditions. Quality control performed at the biobanking facility included pathology review and nucleic acids quality assessment. A total of over 3,000 cases were collected and provided to end-users working on various assays based on cfDNA (e.g. monitoring for minimal residual disease or multi-cancer early detection). Immuno-reactivity to various antigens in samples collected in Streck and EDTA tubes (from 50 patients) was assessed by peptide microarray binding assay. Feedback information on the quality of samples was shared in 900 cases. Approximately 4% of cases had failed internal pathology review, due to poor preservation, lack of adequate tissue composition, or low tumor volume and 11% failed internal nucleic acid quality assessment (DNA concetration and integrity). The blood collection tubes had no significant impact on serologic testing using peptide microarary assay. Customer feedback data showed that overall success rate exceeded 85%. Type of blood collection tubes (Streck vs EDTA) had no impact on serologic testing and studies looking at predicted neoantigens based on NGS data can be confirmed using peptide epitope arrays. Blood collected for NGS works without compromise on peptide arrays. Future validation of other collection tubes for blood or other types of fluids is needed to confirm their adequacy for specific assays. Citation Format: Zoran Gatalica, Phillip Stafford, Chris Diehnelt, Inga Rose. Quality control of the biobanked matched tissue: Blood samples for the development of diverse liquid based molecular assays [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A013.

Genetic diversity of Theileria spp. in deer (Artiodactyla: Cervidae) from Brazil.

Babesia spp. and Theileria spp. are tick-borne apicomplexan protozoa that can cause disease in animals and humans. Deer are considered reservoirs for a wide variety of Piroplasmida species, including some potentially zoonotic. This study aimed to investigate the occurrence and genetic diversity of piroplasmids in wild deer sampled in four Brazilian states (São Paulo, Mato Grosso do Sul, Paraná and Goiás). For this purpose, extracted DNA samples from 181 deer buffy coat samples (138 Blastocerus dichotomus, 26 Subulo gouazoubira, 4 Mazama jucunda, 3 Mazama rufa and 10 Ozotocerus bezoarticus) were subjected to a nested PCR (nPCR) assay based on the 18S rRNA gene in order to perform a screening for piroplasmids and characterized based on the near-complete 18S rRNA, hsp70 and cox-3 genes. As a result, 75.14% (136/181) samples were positive for piroplasmids. Of these, 108 (79.41%), 101 (74.26%) and 67 (49.26%) were positive to near complete 18S rRNA, hsp70 and cox-3 genes, respectively. Phylogenetic analyses based on three molecular markers showed similar topology to each other. All sequences obtained in the present study were positioned into the Theileria sensu stricto clade, forming a distinct clade, albeit close to T. cervi. Most sequences grouped together into a large clade divided into subclades, which were often related to deer genus/species, showing that Theileria lineages seemed to show specificity according to deer genus/species. Two 18S rRNA sequences (one obtained from S. gouazoubira and another from M. jucunda) were positioned into a different clade, apart from other sequences detected in this study, indicating that different species of Theileria occur in deer from Brazil. Two subclusters were observed in the phylogenetic analysis based on the hsp70 gene: the first containing only sequences detected in marsh deer and the second grouping sequences detected in brocket deer (Mazama spp. and S. gouazoubira). The latter was also divided into smaller clades that grouped Theileria genotypes according to deer species (M. jucunda, M. rufa and S. gouazoubira). This study provides the first molecular evidence of Theileria infection in M. jucunda, as well as co-infection by distinct Theileria (sub)species/genotypes in the same deer was evidenced. Finally, this study expanded the knowledge on the diversity of Theileria spp. infecting deer from South America.

Aqueous electrophoretic deposition of yttrium-doped nanobioactive glass/collagen/chitosan orthopedic coatings on 316L SS

The current study used yttrium-doped nanobioactive glass (Y-nBG), based on 62 SiO2 – (33 – x) CaO – 5 P2O5 – x Y2O3 mole % system (x = 0 and 3 mol %), collagen, and chitosan composites for coating 316L stainless steel (316L SS) using aqueous electrophoretic deposition (EPD) technique. The corresponding coated samples are encoded as SS/Col-Chit, SS/BG-Y0/Col-Chit, and SS/BG-Y3/Col-Chit, respectively. Physicochemical characterization implied TGA, FTIR, SEM-EDX, contact angle, adhesion strength and in vitro bioactivity in SBF were performed. Following SBF immersion, FTIR and SEM-EDX investigations were also carried out. Furthermore, the coatings were loaded with gentamicin drug; the drug-release profile and mechanism were evaluated. The antibacterial efficacy of the composite coatings was also assessed. The results showed the formation of homogeneous coatings with good adhesion strength, 1.39 MPa, 0.55 MPa, and 0.81 MPa, and enhanced the wettability by decreasing the contact angle 36⁰, 22⁰ and 12⁰ for SS/Col-Chit, SS/BG-Y0/Col-Chit and SS/BG-Y3/Col-Chit coatings, respectively. In vitro bioactivity of coatings containing nBG revealed apatite formation after immersion in SBF. Furthermore, the antibiotic gentamicin showed a sustained release profile over time by diffusion mechanisms based on the Higuchi, Fickian, and Weibull models. As well, all coatings containing drugs have an antibacterial effect. Overall, these findings suggested that the prepared coatings have potential applications as orthopedic and dental implants.

Effects of Copper Doping on Fluorohydroxyapatite Coating: Analysis of Microstructure, Biocompatibility, Corrosion Resistance, and Cell Adhesion Characteristics.

In this research, Cu-doped fluorohydroxyapatite (Cu-FHAp) coatings containing varying levels of Cu in electrolyte as a dopant were synthesized by the ultrasonic-assisted pulse-reverse electrodeposition method on AZ31 alloy to improve the biocompatibility and corrosion resistance of the alloy for biomedical applications. Microstructural analysis revealed that the inclusion of the Cu dopant results in the formation of a more uniform coating. Energy dispersive spectroscopy analysis highlights a notable incorporation of copper within the fluorohydroxyapatite structure. The increase in Cu content significantly affected surface roughness and elevated hydrophobicity, leading to a contact angle of up to 136°. Electrochemical impedance spectroscopy analysis revealed that all samples containing copper exhibited favorable corrosion resistance, with the sample prepared using the electrolyte containing 0.036 g/L Cu(NO3)2 demonstrating the highest corrosion resistance. Cell adhesion evaluation yielded a satisfactory cell adhesion to the coated samples, indicating that the presence of the optimum value of Cu does not induce considerable cytotoxic effects.

Surface modification of surgical suture by chitosan-based biocompatible hybrid coatings: In-vitro anti-corrosion, antibacterial, and in-vivo wound healing studies

This work aims to develop chitosan-based biocompatible hybrid coatings on synthetic surgical sutured by direct current electrophoretic deposition (DC-EPD) method. The chitosan (CS), curcumin (CR), aloe-vera (AV), and 2-aminothiazolidin-4-one-5-ethanoic acid (AT) were used as suspensions of varying combinations and compositions (A–I). Each suspension has a further 05 samples (Aa–Ae–Ia–Ie) at selected DC-EPD set parameters (2–10 V, t; 240 s, D; 1 cm). Potentiodynamic polarization measurements (PDP) were carried out in the ringer solution. Among all samples, Ed (CS, 1.6 g/L; 8 V) and Hb (CS–CR–AT, 1.6 g/Leach; 4 V) have shown greatest corrosion inhibition efficiency (IEPDP: 99 %), least corrosion rates (CR; 0.001 mm/y and 0.017 mm/y, respectively), and least corrosion current density (Icorr.; 0.01 A cm−2). SEM and FTIR further confirmed these two best coatings stable and corrosion resistant before and after performing corrosion test, while the coating thickness by profilometry test was found to be greater (16.28 μm) for Hb. Mechanical stress and strain of bare and coated samples were found to have no significant difference. Antibacterial activity revealed greater resistance of Hb against S. aureus as compared to Ed. In-vivo incision wound model study further revealed better healing and less inflammation with coated sutures with comparatively enhanced wound healing effect of Hb coated suture.

Ultra-Pressurized Deposition of Hydrophobic Chitosan Surface Coating on Wood for Fungal Resistance.

Fungi (Neolentinus lepideus, Nl, and Trametes versicolor, Tv) impart wood rot, leading to economic and environmental issues. To overcome this issue, toxic chemicals are commonly employed for wood preservation, impacting the environment and human health. Surface coatings based on antimicrobial chitosan (CS) of high molar mass (145 × 105 Da) were tested as wood preservation agents using an innovative strategy involving ultra-pressurizing CS solutions to deposit organic coatings on wood samples. Before coating deposition, the antifungal activity of CS in diluted acetic acid (AcOOH) solutions was evaluated against the rot fungi models Neolentinus lepideus (Nl) and Trametes versicolor (Tv). CS effectively inhibited fungal growth, particularly in solutions with concentrations equal to or higher than 0.125 mg/mL. Wood samples (Eucalyptus sp. and Pinus sp.) were then coated with CS under ultra-pressurization at 70 bar. The polymeric coating deposition on wood was confirmed through X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) images, and water contact angle measurements. Infrared spectroscopy (FTIR) spectra of the uncoated and coated samples suggested that CS does not penetrate the bulk of the wood samples due to its high molar mass but penetrates in the surface pores, leading to its impregnation in wood samples. Coated and uncoated wood samples were exposed to fungi (Tv and Nl) for 12 weeks. In vivo testing revealed that Tv and Nl fungi did not grow on wood samples coated with CS, whereas the fungi proliferated on uncoated samples. CS of high molar mass has film-forming properties, leading to a thin hydrophobic film on the wood surface (water contact angle of 118°). This effect is mainly attributed to the high molar mass of CS and the hydrogen bonding interactions established between CS chains and cellulose. This hydrophobic film prevents water interaction, resulting in a stable coating with insignificant leaching of CS after the stability test. The CS coating can offer a sustainable strategy to prevent wood degradation, overcoming the disadvantages of toxic chemicals often used as wood preservative agents.

Improving hot corrosion behaviour of Cr3C2-25NiCr coatings by reinforcing nano yttria stabilized zirconia at 850 °C

Yttria-Stabilized Zirconia (YSZ)-enhanced Cr3C2-25NiCr coatings were applied to T22 boiler tube steel using the High Velocity Oxy Fuel (HVOF) method. Conventional Ni-20Cr, 5 wt.% YSZ- Cr3C2-25NiCr, and 10 wt.% YSZ- Cr3C2-25NiCr composite coatings were prepared. High-temperature corrosion tests were conducted on both uncoated and coated samples in a Na2SO4-60%V2O5 environment at 850°C under fluctuating thermal conditions. These experiments were carried out in a silicon tube furnace at high temperatures, with each sample subjected to 50 cycles of exposure. Each cycle consisted of 1 hour in the corrosive environment followed by 20 minutes of cooling at room temperature. Corrosion products were analyzed using energy-dispersive x-ray analysis (EDS) and scanning electron microscopy (SEM). The addition of YSZ to the Cr3C2-25NiCr coatings significantly improved corrosion resistance, with the Ni-20Cr, 5 wt.% YSZ-Ni-20Cr, and 10 wt.% Cr3C2-25NiCr coatings reducing overall weight gain by 73.08%, 84.70%, and 89.96%, respectively, compared to uncoated T22 steel.

Easily Applicable Superhydrophobic Composite Coating with Improved Corrosion Resistance and Delayed Icing Properties

Mitigating the adverse effects of corrosion failure and low-temperature icing on aluminum (Al) alloy materials poses significant research challenges. The facile fabrication of bioinspired superhydrophobic materials offers a promising solution to the issues of corrosion and icing. In this study, we utilized laboratory-collected candle soot (CS), hydrophobic fumed SiO2, and epoxy resin (EP) to create a HF-SiO2@CS@EP superhydrophobic coating on Al alloy surfaces using a spray-coating technique. Various characterization techniques, including contact angle meter, high-speed camera, FE-SEM, EDS, FTIR, and XPS, were employed to investigate surface wettability, morphologies, and chemical compositions. Moreover, a 3.5 wt.% NaCl solution was used as a corrosive medium to evaluate the corrosion resistance of the uncoated and coated samples. The results show that the capacitive arc radius, charge transfer resistance, and low-frequency modulus of the coated Al alloy significantly increased, while the corrosion potential (Ecorr) shifted positively and the corrosion current (Icorr) decreased by two orders of magnitude, indicating improved corrosion resistance. Additionally, an investigation of ice formation on the coated Al alloy at −10 °C revealed that the freezing time was 4.75 times longer and the ice adhesion strength was one-fifth of the uncoated Al alloy substrate, demonstrating superior delayed icing and reduced ice adhesion strength performance.

B-184 Purifying High-Quality Genomic DNA From Frozen Blood Samples Stored up to 1.5 Years at -20°C

Abstract Background Maintaining DNA integrity in blood samples, from transport to storage to processing, is crucial to the success of downstream applications, especially regarding diagnostic applications. Additionally, due to the invasive nature of collecting blood samples, minimizing resampling to avoid excess patient pain and cost of collection and transportation are important to consider. Having the option to store and maintain portions of blood samples in the freezer enables future retesting without recollection. Since -20°C freezers generally are more affordable, require less energy, and have smaller footprints than -80°C freezers, demonstrating frozen blood stability at -20°C temperatures could decrease sampling burdens for labs with facility constraints. Methods Whole blood was collected into 9mL vacuum tubes (HemaSure-OMXP) from healthy donors. Aliquots of whole blood and buffy coat samples were stored at -20°C and thawed for genomic DNA extractions (QIAamp DNA Blood Mini Kit, Qiagen) at a range of different timepoints; frozen whole blood samples were processed at 0, 49, 141, and 148 days and frozen buffy coat samples were processed at 7, 27, 36, 185, 246, 373, 394, 584, and 604 days. Purified gDNA was quantified with Qubit (Broad Range dsDNA Assay, ThermoFisher) and qualified with Nanodrop One Microvolume UV-Vis Spectrophotometer (ThermoFisher) and TapeStation (Genomic DNA ScreenTape, Agilent Technologies). Results No significant decrease was observed for DNA yield and quality between fresh and frozen whole blood samples. Average DNA yields from 200 μL whole blood were 4.5 ± 2.2 μg and 5.3 ± 1.2 μg for fresh and frozen blood respectively. Average DNA integrity (DIN) was 6.9 ± 0.4 and 7.1 ± 0.3 for fresh and frozen blood respectively. Donor differences in blood samples can help explain the variance in DNA yields reported. No significant decrease was observed for DNA yield and quality in buffy coat samples frozen for longer at -20°C. In total, 84 whole blood and 25 buffy coat samples were processed in this study. Conclusions Although buffy coat samples tended to have higher yields than whole blood, due to the higher amount of white blood cells present, both sample types provided sufficient amounts of gDNA for downstream applications. Freezing blood samples for future testing can be effective at reducing the need for resampling without sacrificing the nucleic acid yield or quality of fresh samples. Additionally, as technological advancements are made for equipment and assays, frozen blood samples can be retested and compared to previous results for improved diagnostic decisions, done without requiring recollection from labs and patients.

Latex-Bridged Inverse Pickering Emulsion for Durable Superhydrophobic Coatings with Dual Antibacterial Activity.

There is agreement that every colloidal structure produces its own set of unique characteristics, properties, and applications. A colloidal phenomenon of latex-bridged water in a dimethyl carbonate (DMC) Pickering emulsion stabilized by R202 hydrophobic silica was investigated for its ability to act as a superhydrophobic coating (SHC) for cellulose substrates. First, various emulsion compositions were screened for their stability and droplet size. The final composition was then cross-examined by cryogenic scanning electron microscopy and optical and fluorescent microscopy to verify the colloidal structure. The drying pattern of the coating was investigated by using labeled samples under a fluorescent microscope and by scanning electron microscopy on a paper substrate. After the final ∼3 μm of dry coating was applied, it exhibited superhydrophobicity (advancing contact angle = 155°) and full functionality after 5 min at room temperature (RT). Coated samples maintained superhydrophobicity after 20 abrasion cycles and mechanical integrity after 50 s of water immersion. The SHC-coated paper demonstrated compatibility with a standard laser printer, and the coated paper demonstrated superhydrophobicity after printing. Finally, a propolis/DMC extract was produced and then analyzed by gas chromatography-mass spectroscopy (GC-MS) and infused into the SHC (PSHC). The newly formed PSHC demonstrated its ability to act effectively against E. coli biofilm and S. aureus planktonic cells and reduce their viability by over 90% and 99.99%, respectively.

STRUCTURE FORMATION OF Ni−P ALLOY ELECTROCOATINGS WITH INCREASED CORROSION RESISTANCE

Purpose of research. The main factors that reduce the protective properties of electrocrystallized coatings are the formation of volumetric defects − pores, as well as the occurrence of microgalvanic couples at grain boundaries, that is, on surface defects of the crystalline structure. Creating a non-porous structure in electrocoatings, eliminating the formation of surface defects in metal/alloy layers, as well as the possibility of replacing chromium coatings, which are obtained from toxic electrolytes, are urgent tasks. Materials and methodology. In the work, it was proposed to use electrocoatings with Ni−P alloy as protective layers on products that increase corrosion resistance. An X-ray determination of the phase composition of Ni−P electrochemical deposits was carried out. The surface morphology and corrosion resistance of coatings were studied. Results. Samples of electrochemical coatings of pure nickel and nickel-phosphorus alloy were studied. It has been established that during the formation of nickel coatings with the addition of phosphorus ions, the surface morphology has practically no pores, amorphization of deposits occurs, due to which the protective properties, namely, corrosion resistance, are improved. Scientific novelty. Factors have been identified that influence the increase in corrosion resistance of coatings − the absence of a porous structure and the formation of an amorphous state. Conclusions. The influence on the structure and properties of electrochemical coatings of a nickel-phosphorus alloy has been studied. It has been established that the addition of phosphorus ions to the nickel plating electrolyte leads to the formation of an amorphous structure in the coatings, and layers of the Ni−P alloy appear practically without the presence of pores. It has been established that the effect of increasing the corrosion resistance of the electrochemical coating with a nickel-phosphorus alloy (by 30 %) is due to the formation of an amorphous structure of the solidifying metal liquid while preventing the crystallization process during electrochemical deposition.

Osteoblast and osteoclast activity on collagen-based 3D printed scaffolds enriched with strontium-doped bioactive glasses and hydroxyapatite nanorods for bone tissue engineering

Bone tissue engineering (BTE) aims to promote bone regeneration by means of the synergistic effect of biomaterials, cells, and other factors, as potential alternative to conventional treatments for bone fractures. To this aim, a composite material was developed, based on collagen type I, strontium-enriched mesoporous bioactive glasses, and hydroxyapatite nanorods as bioactive and biomimetic components. Nanostructured scaffolds were 3D printed and subsequently chemically crosslinked with genipin to improve mechanical properties and stability. The developed nanostructured system was maintained in culture until 3 weeks with a co-culture of human bone cells to provide anex vivomodel of bone microenvironment and examine the cellular crosstalk and signaling pathways through paracrine cell activities. Human osteoblasts (OBs), derived from trabecular bone, and human osteoclast precursors (OCs), isolated from buffy coat samples were involved, with OBs seeded on the scaffold and OC precursors seeded in a transwell device. When compared to the material without inorganic components, the bioactive and biomimetic scaffold positively influenced cell proliferation and cell metabolic activity, boosting alkaline phosphatase activity of OBs, and reducing OC differentiation. Thus, the bioactive and biomimetic system promoted an enhanced cellular response, highlighting its potential application in BTE.

Investigation of corrosion behavior of Cenosphere reinforced iron based composite coatings

In the present study cenopshere was reinforced with FeCrNiC (Metco 42C) as matrix material and prepared four different feedstock powders such as FeCrNiC+0%Cenosphere, FeCrNiC+5%Cenosphere, FeCrNiC+10%Cenosphere and FeCrNiC+15%Cenosphere were coated by plasma spray technique on T22 substrate. Evaluation of the substrate and coatings potential under salt spray test was performed. Dense fog of 5% NaCl salt water was used to create a corrosive atmosphere within the chamber. The salt water's pH was kept constant at 6.5–7. The materials that underwent corrosion were examined using X-ray diffraction (XRD), and scanning electron microscopy (SEM). The FeCrNiC+15%Cenosphere and FeCrNiC+10%Cenosphere coatings exhibited reduced weight loss during a 168-h corrosion test compared to the FeCrNiC+5%Cenosphere, FeCrNiC coatings, and substrate. The excellent chemical stability and corrosion resistance of Cr23C6, SiO2, NiO, and Cr2O particles contribute to gradually avoid the formation of red rust on Fe-based coated samples with exposure approaches to 52 and 130 h.

Comprehensive study of plasma polymerization parameters on thiol-coated LDPE films for effective fibronectin adsorption targeting biomedical applications

In the realm of biomedical applications, biocompatible materials with optimized surface properties are crucial for facilitating cellular interactions. To attain the perfect balance of these properties, surface modification of non-toxic and stable bulk materials is often required. Within this context, this research aimed to improve the physiochemical and cell-responsive properties of a low-density polyethylene film. This was achieved by depositing thiol-rich coatings using a dielectric barrier discharge plasma reactor operating at medium pressures, with 1-propanethiol serving as polymerization precursor. The study systematically investigated the impact of key plasma polymerization parameters, including DBD chamber pressure, treatment time, and the combination of precursor flow rate and discharge power represented by the Yasuda parameter, to identify optimal plasma processing conditions for the formation of thiol-rich coatings. To characterize the coating thickness, hydrophilicity and surface chemical composition, atomic force microscopy, water contact angle measurements, and X-ray photoelectron spectroscopy were employed. The findings indicated that reducing the chamber pressure to 10 kPa led to more hydrophilic and thicker deposits possessing a higher sulphur content. Deposition time (5 to 15 min) also significantly impacted coating thickness and surface chemistry, where long times increased thickness, but also led to a reduced sulphur and increased oxygen content because of more pronounced etching. The optimal deposition time was therefore set at 10 min resulting in the deposition of dense coatings possessing a high number of sulphur-containing functionalities. The Yasuda parameter (W/FM) analysis demonstrated optimal thiol incorporation in combination with high coating stability at an intermediate W/FM value of 72 MJ/kg. Following the determination of the optimal plasma polymerization parameters, the effectiveness of thiol plasma polymerization and subsequent fibronectin immobilization for enhancing cell adhesion and proliferation was investigated. The thiol-coated substrates were found to exhibit superior protein immobilization, because of the high affinity for protein binding of the available thiol groups. To assess cellular responses, Schwann cells were cultured on uncoated and coated samples before and after fibronectin immobilization. The results revealed a superior cellular response of the thiol-coated samples after fibronectin immobilization, showing the highest cell viability and significantly enhanced cell adhesion and proliferation. Collectively, these results underscore the synergistic effect of thiol plasma polymerization and fibronectin immobilization in promoting the cellular response of LDPE substrates, thus highlighting their potential as a surface modification strategy of biomaterials.

Development of a biomarker prediction model for post-trauma multiple organ failure/dysfunction syndrome based on the blood transcriptome

BackgroundMultiple organ failure/dysfunction syndrome (MOF/MODS) is a major cause of mortality and morbidity among severe trauma patients. Current clinical practices entail monitoring physiological measurements and applying clinical score systems to diagnose its onset. Instead, we aimed to develop an early prediction model for MOF outcome evaluated soon after traumatic injury by performing machine learning analysis of genome-wide transcriptome data from blood samples drawn within 24 h of traumatic injury. We then compared its performance to baseline injury severity scores and detection of infections.MethodsBuffy coat transcriptome and linked clinical datasets from blunt trauma patients from the Inflammation and the Host Response to Injury Study (“Glue Grant”) multi-center cohort were used. According to the inclusion/exclusion criteria, 141 adult (age ≥ 16 years old) blunt trauma patients (excluding penetrating) with early buffy coat (≤ 24 h since trauma injury) samples were analyzed, with 58 MOF-cases and 83 non-cases. We applied the Least Absolute Shrinkage and Selection Operator (LASSO) and eXtreme Gradient Boosting (XGBoost) algorithms to select features and develop models for MOF early outcome prediction.ResultsThe LASSO model included 18 transcripts (AUROC [95% CI]: 0.938 [0.890–0.987] (training) and 0.833 [0.699–0.967] (test)), and the XGBoost model included 41 transcripts (0.999 [0.997–1.000] (training) and 0.907 [0.816–0.998] (test)). There were 16 overlapping transcripts comparing the two panels (0.935 [0.884–0.985] (training) and 0.836 [0.703–0.968] (test)). The biomarker models notably outperformed models based on injury severity scores and sex, which we found to be significantly associated with MOF (APACHEII + sex—0.649 [0.537–0.762] (training) and 0.493 [0.301–0.685] (test); ISS + sex—0.630 [0.516–0.744] (training) and 0.482 [0.293–0.670] (test); NISS + sex—0.651 [0.540–0.763] (training) and 0.525 [0.335–0.714] (test)).ConclusionsThe accurate assessment of MOF from blood samples immediately after trauma is expected to aid in improving clinical decision-making and may contribute to reduced morbidity, mortality and healthcare costs. Moreover, understanding the molecular mechanisms involving the transcripts identified as important for MOF prediction may eventually aid in developing novel interventions.

Impact of Antioxidant-Enriched Edible Gel Coatings and Bio-Based Packaging on Cherry Tomato Preservation.

This research investigates the effects of using edible gel coatings and bio-based packaging materials on extending the shelf life of cherry tomatoes. Two edible gel coatings (guar gum and guar gum +5% of a lemon (Citrus limon (L.) Osbeck pomace extract obtained in the research laboratory) were applied on cherry tomatoes, then they were packaged in bio-based materials (cellulose tray + PLA lid). Guar gum, glycerol, sorbitol, extra virgin olive oil, and tween 20 were used in coating formulation. Uncoated tomatoes packed in bio-based materials and conventional plastic (PET trays + lid) were tested as a control. Samples were stored for 45 days at 20 °C and their quality parameters were evaluated. Coated tomatoes maintained firmness and weight, and the enriched coated samples showed a significant increase in phenol content, derived from the antioxidant extract. Samples packed in PET showed a sensory unacceptability (<4.5) after 45 days correlated with a greater decline in firmness (from 10.51 to 5.96 N) and weight loss (from 7.06 to 11.02%). Therefore, edible gel coating and bio-based packaging proved to be effective in maintaining the overall quality of cherry tomatoes for 45 days, offering a promising approach to reduce plastic polymer use and food waste.