A common goal of active packaging is to improve the shelf life, safety, or quality of packaged foods. The integrity of an active package must be remained in order to prevent the growth of microorganisms on the surface of food. Therefore, active polyvinyl alcohol-Alyssum homolocarpum seed gum (PVA-AHSG) composite films with different nisin concentrations (3000, 5000 and 10,000 IU) were prepared and their physico-chemical and antimicrobial properties were determined. Addition of nisin to the composite films increased their water vapor permeability (WVP), elongation at break (EB) and opacity, whereas their total color difference (ΔE), glass transition temperature (Tg), melting temperature (Tm), tensile strength (TS) and young modulus (YM) were decreased. Increasing the nisin concentration remarkably increased the chain mobility, interactions between polymers and water molecules and also the free volume of polymer matrix. The antimicrobial potential of film against L. monocytogene, S. aureus and E. coli as well as the release of nisin into phosphate buffer solution (pH 7.2) were investigated. Films containing nisin had inhibition effect against gram positive pathogens among which L. monocytogenes was the most sensitive bacterium. In liquid media, all films containing nisin prevented the growth of L. monocytogenes and S. aureus, but it was only the film with 10,000 IU nisin content which was able to control 100% of the microbial population during incubation time. Nisin release and diffusion coefficient (D) increased as its concentration increased in the film matrix due to the interaction of nisin with film polymer chains. Therefore, the resultant film had appropriate controlled release property and suitable microbial inhibitory against gram positive bacteria.
Composite bioactive films based on polyvinyl alcohol-Alyssum homolocarpum seed gum blend and Nisin: Physiochemical characterization and antimicrobial properties. Monjazeb et al. (2017).
A series of heterocyclic and hydrocarbon [8]circulenes (also named completely annelated tetraphenylenes) were studied by the NICS and GIMIC methods in order to describe their aromatic properties from the magnetic criterion point of view. According to calculations all the hetero[8]circulene molecules demonstrate the bifacial aromatic/antiaromatic nature. The inner octatetraene core of the studied [8]circulenes is characterized by the presence of paratropic (“antiaromatic”) ring currents, whereas the outer macrocycle constructed from the five- and six-membered rings possesses the magnetically-induced diatropic (“aromatic”) ring current. The hydrocarbon [8]circulenes studied in this work consist of a similar planar cyclooctatetraene core but they exhibit a rather different balance of magnetically-induced ring currents.
Aromaticity of the completely annelated tetraphenylenes
Soybean hull is an agroindustrial waste which has not been fully studied as a food ingredient. The aims of this work were to obtain insoluble fibers from soybean hull and to evaluate the effect of high pressure homogenization (HPH) on its physicochemical properties. Hull insoluble polysaccharides (HIPS) were obtained in a single step, as the insoluble residue after pectin removal. FTIR showed bands corresponding to cellulose and hemicellulose in HIPS, and thermogravimetric analysis showed two degradation events at 236.3 °C and 325.6 °C, corresponding to cellulose and hemicellulose, respectively. HIPS dispersions (pH 3.00) were subjected to HPH by three cycles at increasing pressures (up to 1000 bar), obtaining soybean hull nanofibers. SEM images show that HPH at 1000 bar reduced the dimensions of the fiber bundle from 30 to 90 μm in length and 9–15 μm in diameter to nanofibers of 10–30 μm in length and 100–400 nm in diameter. AFM further confirms a heterogeneous distribution of sizes in HIPS800 and HIPS1000, evidencing the presence of individual nanofibers with diameters around 50 ± 10 nm and 40 ± 10 nm, respectively, with several μm in length. Furthermore, an increase in water holding capacity from 2.1 to 61 gwater/gdry matter and viscosity from 0.39 to 34,945 Pa.s were achieved as HPH at 1000 bar treatment was applied. HPH increased the interfacial area and promoted the interconnection of fibers in a hydrated gel-like structure. This explains flow behavior, which was extensively studied in this work: three-region viscosity profile (shear-thinning, plateau or shear-thickening and shear-thinning) and a pronounced hysteresis loop. Oscillatory rheology was used to study the viscoelastic behavior of HIPS dispersions. HIPS are a source of nanofibers, easy to obtain through a single step of chemical treatment followed by the application of high pressures. It is remarkable that the use of few chemical solvents is favorable from an environmental point of view. This work also suggests a potential application of HIPS to improve physicochemical and structural properties in acidic foods.
Graphical Abstract
In spray dried emulsions, frequently milk proteins are used as interfacial active components and starch conversion products are added as matrix material at high concentrations. To characterize interfacial properties at the oil/water interface by commonly applied methods, low protein, and carbohydrate concentrations from 1 to 2% are usually analyzed. The impact of a higher concentration of starch conversion products was not investigated so far. Therefore, the formation and rheological properties of β-lactoglobulin (β-LG) stabilized films at the oil/water interface were investigated via short and long-time adsorption behavior using pendant drop tensiometry as well as dilatational and interfacial shear rheology. Suitability of the applied methods to the chosen samples with higher concentrations >1–2% was verified by calculation of selected key numbers like capillary number and by detailed reviewing of the results which is summarized further on as key indicators. It is hypothesized, that the increase in concentration via presence of starch conversion products will delay interfacial stabilization as a result of increased bulk viscosity with decreasing degree of degradation (dextrose equivalent) of the starch. Furthermore, this increase in concentration leads to more stable interfacial films due to thermodynamic incompatibility effects between protein and starch conversion products which results in increases of local protein concentration. Key indicators proved a general suitability of applied methods for the evaluation of the investigated samples. Moreover, results showed an increase in interfacial film stability and elastic properties alongside a decreased interfacial tension if starch conversion products were present in a high concentration.
Graphical abstract
The continuous availability of cells with defined cell characteristics represents a crucial issue in the biopharmaceutical and cell therapy industry. Here, development of cell banks with a long-term stability is essential and ensured by a cryopreservation strategy. The strategy needs to be optimized for each cell application individually and usually comprises controlled freezing, storage at ultra-low temperature, and fast thawing of cells. This approach is implemented by the development of master and working cell banks. Currently, empirical cryopreservation strategy development is standard, but a knowledge-based approach would be highly advantageous. In this article, we report the development of a video-based tool for the characterisation of freezing and thawing behaviour in cryopreservation process to enable a more knowledge-based cryopreservation process development. A successful tool validation was performed with a model cryopreservation process for the β-cell line INS-1E. Performance was evaluated for two working volumes (1.0 mL and 2.0 mL), based on freezing-thawing rates (20 °C to − 80 °C) and cell recovery and increase of biomass, to determine tool flexibility and practicality. Evaluation confirmed flexibility by correctly identifying a delay in freezing and thawing for the larger working volume. Further more, a decrease in cell recovery from 0.94 (± 0.14) % using 1.0 mL working volume to 0.61 (± 0.05) % using a 2.0 mL working volume displays tool practicality. The video-based tool proposed in this study presents a powerful tool for cell-specific optimisation of cryopreservation protocols. This can facilitate faster and more knowledge-based cryopreservation process development
Graphical abstractIn this study, a video-based analytical tool was developed for the characterisation of freezing and thawing behaviour in cryopreservation process development. Evaluation of the practicality and flexibility of the developed tool was done based on a scale-up case study with the cell line INS-1E. Here, the influence of sample working volume on process performance was investigated. Increasing the volume from 1to 2 mL led to a delay in freezing and thawing behaviour which caused cell recovery loss. We believe that the developed tool will facilitate more directed and systematic cryopreservation process development.
In the present work, a series of simulation tools were used to determine structure-activity relationships for the endomorphins (EMs) and derive μ-pharmacophore models for these peptides. Potential lowest energy conformations were determined in vacuo by systematically varying the torsional angles of the Tyr1-Pro2 (ω1) and Pro2-Trp3/Phe3 (ω2) as tuning parameters in AM1 calculations. These initial models were then exposed to aqueous conditions via molecular dynamics simulations. In aqueous solution, the simulations suggest that endomorphin conformers strongly favor the trans/trans pair of the ω1/ω2 amide bonds. From two-dimensional probability distributions of the ring-to-ring distances with respect to the pharmacophoric angles for EMs, a selectivity range of μ1 is ca. 8.3 ~ 10.5 Å for endomorphin-2 and selectivity range of μ2 is ca. 10.5 ~ 13.0 Å for endomorphin-1 were determined. Four-component μ-pharmacophore models are proposed for EMs and are compared to the previously published δ- and κ-pharmacophore models.
Angle NAB/C vs distance
In utero hyperglycemia has consequences on future outcomes in the offsprings. We had earlier shown that in utero hyperglycemia impacts proteoglycans/glycosaminoglycans, one of the key molecules involved in brain development. Hypothalamic HSPGs such as syndecan-1 and syndecan-3 are well known for their involvement in feeding behavior. Therefore, studies were carried out to determine the effect of maternal hyperglycemia on the expression of HSPGs in the hypothalamus of offspring brain. Results revealed increased protein abundance of Syndecan-1 and -3 as well as glypican-1 in postnatal adults from hyperglycemic mothers. This was associated with increased hyperphagia and increased expression of Neuropeptide Y. These results indicate the likely consequences on offsprings exposed to in utero hyperglycemia on its growth.
Graphical abstractGlobally, water resources contaminated with petroleum hydrocarbons are under much consideration due to their hazardous effects on human beings as well as on plants and animals in the ecosystem. Petroleum hydrocarbons are classified as recalcitrant pollutants in nature. These petroleum products are mostly released in the water resources during the petroleum refining process by oil refineries. The conventional clean-up technologies for hydrocarbons contaminated water have more destructive effects on the aquatic and land ecosystems. Consequently, to develop cost-effective and more environment-friendly techniques that clean up the environment and restore the marine ecosystem to its original forms. Keeping in view, this review article explores the detailed information on fabrication, cost-effectiveness, and an overview of innovation of the floating treatment wetlands (FTWs) using plants and bacterial combined functions to remediate the petroleum hydrocarbons contaminated water. The review also discusses the improvement of microbial efficacy for hydrocarbon degradation using FTWs. The review article shows the various applications of FTWs to remove different organic pollutants in petroleum hydrocarbons contaminated water. The review also describes the prospective benefits of FTWs for their multiple uses for removal of hydrocarbons, chemical oxygen demand (COD), biochemical oxygen demand (BOD), phenol, and solids from hydrocarbons contaminated water. This review widely discusses the role of hydrocarbons in degrading bacteria, and wetland plants and the mechanism involved during the remediation process of hydrocarbons in FTWs. It further demonstrates features disturbing the treatment efficiency of FTWs, and finally, it is concluded by successful applications of FTWs and various suggestions for potential future research prospects.
Graphical AbstractCircular RNA of vimentin (circ-VIM) is a predictor for poor prognosis of acute myeloid leukemia, but we had little information on its function in esophageal cancer (EC). Here we examined the effects of circ-VIM together with sevoflurane on immune escape and multiple oncogenic activities of EC.
MethodsBioinformatic tools, luciferase assay, and RNA immunoprecipitation were used to examine regulations between circ-VIM, miR-124-3p (miR-124), and PD-L1. CCK-8, wound healing, and Transwell assays were used to measure cell proliferation, migration, and invasion, respectively. The impacts of EC cells on cytotoxicity, proliferation, and apoptosis of CD8+ T cells were examined using LDH assay, CFSE staining, and Annexin V/PI staining, respectively. The in vivo tumorigenesis and lung metastases were assessed using xenograft model and tail vein injection of EC cells.
ResultsSignificant upregulation of circ-VIM and PD-L1 and downregulation of miR-124 were detected in EC tissues or cells. Circ-VIM sponged miR-124 and released its suppression on the downstream target PD-L1. Sevoflurane, independent of circ-VIM, also upregulated miR-124 to lower PD-L1 expression. By modulating miR-124/PD-L1 axis, silencing circ-VIM and applying sevoflurane both inhibited immune escape and multiple oncogenic activities of EC in vitro, and suppressed xenograft growth and lung metastases in vivo. The inactivation of Ras/ERK signaling pathway was involved in suppression of malignant phenotypes by silencing circ-VIM and sevoflurane treatment.
ConclusionsSilencing circ-VIM and applying sevoflurane, by separately regulating miR-124/PD-L1 axis, presented synergistic effects in inhibiting immune escape and multiple malignant phenotypes of EC cells.
Graphical abstractNon-invasive microstructural characterisation has the potential to determine the stability, or lack thereof, of atherosclerotic plaques and ultimately aid in better assessing plaques’ risk to rupture. If linked with mechanical characterisation using a clinically relevant imaging technique, mechanically sensitive rupture risk indicators could be possible. This study aims to provide this link–between a clinically relevant imaging technique and mechanical characterisation within human atherosclerotic plaques. Ex vivo diffusion tensor imaging, mechanical testing, and histological analysis were carried out on human carotid atherosclerotic plaques. DTI-derived tractography was found to yield significant mechanical insight into the mechanical properties of more stable and more vulnerable microstructures. Coupled with insights from digital image correlation and histology, specific failure characteristics of different microstructural arrangements furthered this finding. More circumferentially uniform microstructures failed at higher stresses and strains when compared to samples which had multiple microstructures, like those seen in a plaque cap. The novel findings in this study motivate diagnostic measures which use non-invasive characterisation of the underlying microstructure of plaques to determine their vulnerability to rupture.
Graphic abstractSilver (Ag) nanoparticles (NPs) and Ag nanorings (NRs) have been fabricated. Due to the inherent features of Ag NPs and Ag NRs, strong electromagnetic (EM) near-field distributions were expected, and hence surface-enhanced Raman scattering (SERS) activity was demonstrated. Size and interparticle gaps distribution of Ag NPs were estimated to be 48.14?±?10.14 nm and 14.11?±?5.24 nm respectively along with estimated coverage density of?~?4?×?1010 cm?2. On the other hand, Ag NRs were found to consist of Ag clusters and of various shapes and sizes, instead of a perfect ring structure. High-resolution FESEM revealed that the individual constituent clusters were different from each other, particularly in terms of size and shape in addition to the cases how such clusters were connected to form the edge of the NR. However, the coverage density of Ag NRs was estimated to be?~?5.6?×?106 cm?2. Based on the scenarios, it was speculated that the local EM near-field distribution would excel and thus led to enhanced SERS signals. SERS enhancement of R6G was estimated as high as 2.18?×?104 and 2.78?×?104 at 610 cm?1 (C???C ring bending mode in phenyl rings) for Ag NPs and Ag NRs respectively. FDTD analysis was carried out to elucidate the EM near-field distributions.
Graphical abstractAg NPs and Ag NRs from an ultrathin layer of Ag on ZnO/Glass (middle pane) confirming high EF of R6G adsorbed on Ag NRs (right pane) and Ag NPs (left pane) supported by corresponding EM near-field distributions.
Angiotensin converting enzyme (ACE) is considered as main causative agent in growing hypertension and other cardiovascular disorders. Inhibition of ACE by producing and purifying bioactive peptides of fermented goat milk is aimed in this study. Protein extracted from goat milk was hydrolyzed with proteolytic enzymes of LH (Lactobacillus helveticus-cicc22171). ACE inhibitory peptides were purified from fermented samples of goat milk protein by optimizing incubation time to 8 h (S-8), 16 h (S-16), 24 h (S-24) and 36 h (S-36), via ultrafiltration. S-8 was used as control to compare the ACE inhibition trend. Molecular weight cut-off; 10000 Da (PM-10) and Ultracel 3K membrane was used to perform ultrafiltration. Sample with 24 h incubation time was considered as best hydrolyzed as compared to others, by applying Nin-Hydrin reaction and SDS-PAGE analysis. ACE inhibitory assay validated the authenticity of S-24 in inhibiting ACE, in vitro. Furthermore, Q executive hybrid quadrupole-orbitrap mass spectrometry was used to determine molecular structure and amino acid sequence of ACE inhibitory peptides. Three peptides, VLPVPQKAVPQ, VLPVPQKVVPQ and TQTPVVVPPFLQPEIMGVPKVKE containing functional amino acid structure, has been identified with highest ACE inhibitory activity on the basis of intensity, size and higher concentration of hydrophobic amino acids as shown in figure as graphical abstract. Fermented goat milk containing these novel bioactive peptides, can be used as nutraceuticals to inhibit ACE and control hypertension in future.
Graphical Abstract