Antiviral and Antibacterial Cold Spray Coating Application on Rubber Substrate, Disruption in Disease Transmission Chain.

The objective of this study was to prepare a copper-coated rubber surface using cold spray technology with improved virucidal and antimicrobial properties to fight against highly transmissible viruses and bacteria. A successful cold spray coating was produced using irregular-shaped pure Cu powder on an escalator handrail rubber. The powder particles and the deposited coatings (single and double pass) were characterized in terms of particle morphology and size distribution, coating surface and coat/substrate cross-section properties. The bonding between powder and rubber surfaces was purely mechanical interlocking. The Cu powder penetration depth within the rubber surface increases with a number of depositions pass. The virucidal properties of the coated surface were tested utilizing surrogates for SARS-CoV-2: HCoV-229E, a seasonal human coronavirus, and baculovirus, a high-titer enveloped insect cell virus. A double-pass coated surface showed significant baculovirus inactivation relative to a bare rubber control surface after 2-h (approximately 1.7-log) and 4-h (approximately 6.2-log), while a 4-h exposure reduced HCoV-229E titer to below the limit of detection. A similar microbial test was performed using E. coli, showing a 4-log microbial reduction after 2-h exposure relative to the bare rubber. These promising results open a new application for cold spray in the health sector. Supplementary Information: The online version contains supplementary material available at 10.1007/s11666-023-01553-x.

Parameter oscillation attenuation and mechanism exploration for continuous VHG ethanol fermentation.

A bioreactor system composed of a stirred tank and three tubular bioreactors in series was established, and continuous ethanol fermentation was carried out using a general Saccharomyces cerevisiae strain and a very high gravity medium containing 280 g L(-1) glucose, supplemented with 5 g L(-1) yeast extract and 3 g L(-1) peptone. Sustainable oscillations of glucose, ethanol, and biomass were observed when the tank was operated at the dilution rate of 0.027 h(-1), which significantly affected ethanol fermentation performance of the system. After the tubular bioreactors were packed with 1/2'' Intalox ceramic saddles, the oscillations were attenuated and quasi-steady states were achieved. Residence time distributions were studied for the packed bioreactors by the step input response technique using xylose as a tracer, which was added into the medium at a concentration of 20 g L(-1), indicating that the backmixing alleviation assumed for the packed tubular bioreactors could not be established, and its contribution to the oscillation attenuation could not be verified. Furthermore, the role of the packing's yeast cell immobilization in the oscillation attenuation was investigated by packing the tubular bioreactors with packings with significant difference in yeast cell immobilization effects, and the experimental results revealed that only the Intalox ceramic saddles and wood chips with moderate yeast cell immobilization effects could attenuate the oscillations, and correspondingly, improved the ethanol fermentation performance of the system, while the porous polyurethane particles with good yeast cell immobilization effect could not. And the viability analysis for the immobilized yeast cells illustrated that the extremely lower yeast cell viability within the tubular bioreactors packed with the porous polyurethane particles could be the reason for their inefficiency, while the yeast cells loosely immobilized onto the surfaces of the Intalox ceramic saddles and wood chips could be renewed during the fermentation, guaranteeing their viability and making them more efficient in attenuating the oscillations. The packing Raschig rings without yeast cell immobilization effect did not affect the oscillatory behavior of the tubular bioreactors, further supporting the role of the yeast cell immobilization in the oscillation attenuation.

Ergot alkaloids in some rye-based UK cereal products.

UK rye-based cereal products were analysed for six major ergot alkaloids using an in-house-validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method that distinguished -ine and -inine epimers (isomers). Ergot alkaloids were detected in 25 of 28 samples subject to quantification limits of 1-3 µg kg(-1), including all of eleven rye crispbreads that had up to 340 µg kg(-1). Continental-style rye breads contained up to 121 µg kg(-1). Loaf breads, bread-mix flours, and crackers contained only low levels of alkaloids. Ergotamine, ergocristine, and ergosine were the predominant ergot alkaloids in terms of level and frequency of occurrence. There were no apparent differences in the ergot levels between the organic and non-organic products, although the numbers tested were low. Most rye breads had a ratio of -ines to -inines of about 1.5, and rye crispbreads had lower and more variable -ine to -inine ratios.

Ethanol fermentation technologies from sugar and starch feedstocks.

This article critically reviews some ethanol fermentation technologies from sugar and starch feedstocks, particularly those key aspects that have been neglected or misunderstood. Compared with Saccharomyces cerevisiae, the ethanol yield and productivity of Zymomonas mobilis are higher, because less biomass is produced and a higher metabolic rate of glucose is maintained through its special Entner-Doudoroff pathway. However, due to its specific substrate spectrum as well as the undesirability of its biomass to be used as animal feed, this species cannot readily replace S. cerevisiae in ethanol production. The steady state kinetic models developed for continuous ethanol fermentations show some discrepancies, making them unsuitable for predicting and optimizing the industrial processes. The dynamic behavior of the continuous ethanol fermentation under high gravity or very high gravity conditions has been neglected, which needs to be addressed in order to further increase the final ethanol concentration and save the energy consumption. Ethanol is a typical primary metabolite whose production is tightly coupled with the growth of yeast cells, indicating yeast must be produced as a co-product. Technically, the immobilization of yeast cells by supporting materials, particularly by gel entrapments, is not desirable for ethanol production, because not only is the growth of the yeast cells restrained, but also the slowly growing yeast cells are difficult to be removed from the systems. Moreover, the additional cost from the consumption of the supporting materials, the potential contamination of some supporting materials to the quality of the co-product animal feed, and the difficulty in the microbial contamination control all make the immobilized yeast cells economically unacceptable. In contrast, the self-immobilization of yeast cells through their flocculation can effectively overcome these drawbacks.

Photocatalytic reduction of nitrate in wastewater using ZnO nanopowder synthesized by solution combustion method.

ZnO nanopowder was synthesized by a unique method which is called solution combustion method (SCM). This nanopowder was used for a photocatalyst to decompose nitrate that is a toxic pollutant in wastewater. It has been known that TiO2, the most popular photocatalyst, does not decompose the nitrate. In this paper, however, the SCM ZnO nanopowder decomposed about 13% of nitrate. Furthermore, adding methanol as a hole scavenger, the decomposition rate was enhanced by about 5 times. On the other hand, it has been reported that the photocatalytic reduction reaction of nitrate produces ammonia as a final product. The present results, however, suggest that the final product is non-toxic nitrogen gas rather than the toxic ammonia. These results would be very valuable for drinking water purification.

Rheology and hydrodynamic properties of Tolypocladium inflatum fermentation broth and its simulation.

A physico-chemical, two phase simulated pseudoplastic fermentation (SPF) broth was investigated in which Solka Floc cellulose fibre was used to simulate the filamentous biomass, and a mixture of 0.1% (w/v) carboxymethyl cellulose (CMC) and 0.15 M aqueous sodium chloride was used to simulate the liquid fraction of the fermentation broth. An investigation of the rheological behaviour and hydrodynamic properties of the SPF broth was carried out, and compared to both a fungal Tolypocladium inflatum fermentation broth and a CMC solution in a 50 L stirred tank bioreactor equipped with conventional Rushton turbines. The experimental data confirmed the ability of the two phase SPF broth to mimic both the T. inflatum broth bulk rheology as well as the mixing and mass transfer behaviour. In contrast, using a homogeneous CMC solution with a similar bulk rheology to simulate the fermentation resulted in a significant underestimation of the mass transfer and mixing times. The presence of the solid phase and its microstructure in the SPF broth appear to play a significant role in gas holdup and bubble size, thus leading to the different behaviours. The SPF broth seems to be a more accurate simulation fluid that can be used to predict the bioreactor mixing and mass transfer performance in filamentous fermentations, in comparison with CMC solutions used in some previous studies.

Parameter oscillations in a very high gravity medium continuous ethanol fermentation and their attenuation on a multistage packed column bioreactor system.

The quasi-steady-states, marked by small fluctuations of residual glucose, ethanol, and biomass concentrations, and sustainable oscillations marked by big fluctuations of these monitored fermentation parameters were observed during the continuous ethanol fermentation of Saccharomyces cerevisiae when very high gravity media were fed and correspondingly high ethanol concentrations reached. A high ethanol concentration was shown to be one of the main factors that incited these oscillations, although the residual glucose level affected the patterns of these oscillations to some extent. The lag response of S. cerevisiae to high ethanol stress that causes the shifts of morphology, viability loss, and death of yeast cells is assumed to be one of the probable mechanisms behind these oscillations. It was predicted that the longer the delay of this response was, the longer the oscillation periods would be, which was validated by the experimental data and the comparison with the oscillatory behaviors reported for the ethanologen bacterium, Zymomonas mobilis. Furthermore, three tubular bioreactors in series were arranged to follow a stirred tank bioreactor to attenuate these oscillations. However, exaggerated oscillations were observed for the residual glucose, ethanol, and biomass concentrations measured in the broth from these tubular bioreactors. After the tubular reactors were packed with Intalox ceramic saddle packing, these oscillations were effectively attenuated and quasi-steady-states were observed during which there were very small fluctuations of residual glucose, ethanol, and biomass within the entire experimental run.

A probabilistic estimation of fluoride intake by infants up to the age of 4 months from infant formula reconstituted with tap water in the fluoridated regions of Ireland.

Two probabilistic models were developed to estimate the acute and chronic exposure to fluoride of exclusively formula-fed infants aged 0-4 months as a result of the consumption of infant formula reconstituted with fluoridated tap water in Ireland. The estimates were based on calculated infant formula consumption and accepted body weight standards, together with reported concentrations of fluoride in infant formula powder and measured values for the fluoride content of water in Ireland. The mean acute exposure of infants to fluoride on any single day in areas served by 387 fluoridated water supplies was estimated to be between 0.11 and 0.14 mg/kg body weight depending on age group (95th percentiles 0.2 and 0.26 mg/kg b.w., respectively). These predicted intakes were well below the intake of fluoride associated with acute toxic effects, which is considered to be 5 mg fluoride (F(-))/kg body weight. The mean chronic exposure of infants to fluoride was estimated to be between 0.106 and 0.170 mg/kg b.w./day depending on body weight (95th percentiles 0.108 and 0.172 mg/kg b.w./day, respectively). This estimate described the average daily fluoride intake of infants during the first 4 months of life residing in the areas served by 226 water supplies that achieved an average yearly fluoride concentration below 1.03 mg/l. Dental fluorosis may be considered to be the only risk at these low doses and from our work it is estimated that there is a very low risk of moderate dental fluorosis of the permanent dentition in infants exposed to fluoride at these levels.

Continuous ethanol production and evaluation of yeast cell lysis and viability loss under very high gravity medium conditions.

A combined bioreactor system, composed of a stirred tank and a three-stage tubular bioreactor in series and with a total working volume of 3260 ml, was established. Continuous ethanol production was carried out using Saccharomyces cerevisiae and a very high gravity (VHG) medium containing 280 g l(-1) glucose. An average ethanol concentration of 124.6 g l(-1) or 15.8% (v) was produced when the bioreactor system was operated at a dilution rate of 0.012 h(-1). The yield of ethanol to glucose consumed was calculated to be 0.484 or 94.7% of its theoretical value of 0.511 when ethanol entrapped in the exhaust gas was incorporated. Meanwhile, quasi-steady states and non-steady oscillations were observed for residual glucose, ethanol and biomass concentrations for all of these bioreactors during their operations. Models that can be used to predict yeast cell lysis and viability loss were developed.

Yeast cell adhesion on oligopeptide modified surfaces.

Self-assembling oligopeptides are novel materials with potential bioengineering applications; this paper explores the use of one of these oligopeptides, EAK 16 II, for modifying the surface properties of cell-supporting substrates. To characterize the surface properties, thermodynamic measurements of liquid contact angle and surface free energy were correlated to atomic force microscopy (AFM) observations. A critical concentration of 0.1 mg/ml was found necessary to completely modify the surface properties of the substrate with EAK 16 II. Adhesion of a yeast cell, Candida utilis, was modified by the coating of EAK 16 II on both hydrophobic (plastic) and hydrophilic (glass) surfaces: Cell coverage was slightly enhanced on the glass substrate, but decreased significantly on the plastic substrate. This indicates that the yeast cell adhesion was mainly determined via hydrophobic interactions between the substrate and the cell wall. However, on the EAK 16 II modified glass substrate, surface roughness might be a factor in causing a slightly larger cell adhesion than that on bare glass. The morphology of adhered cells was also obtained with AFM imaging, showing a depression at the center of the cell on all substrates. Small depressions on the oligopeptide-coated surfaces and plastic substrate may indicate good water-retaining ability by the cell. There was no apparent difference in cell adhesion and morphology among cells obtained from lag, exponential and stationary growth phases.

Benzophenone in cartonboard packaging materials and the factors that influence its migration into food.

Benzophenone may be present in cartonboard food-packaging materials as a residue from UV-cured inks and lacquers used to print on the packaging. It may also be present if the cartonboard is made from recycled fibres recovered from printed materials. A method has been devised to test for benzophenone in cartonboard packaging materials and to test for migration levels in foodstuffs. Packaging is extracted with solvent containing d10-benzophenone as the internal standard. Foods are extracted with solvent containing d10-benzophenone and the extract defatted using hexane. The extracts are analysed by GC-MS. For analysis of food, the limit of detection was 0.01 mg x kg(-1) and the limit of quantification was 0.05 mg x kg(-1). The calibration was linear from 0.05 to 20 mg x kg(-1). The method for food analysis was validated in-house and it also returned satisfactory results in a blind check-sample exercise organized by an independent laboratory. The methods were applied to the analysis of 350 retail samples that used printed cartonboard packaging. A total of 207 (59%) packaging samples had no significant benzophenone (<0.05 mg x dm(-2)). Seven (2%) were in the range 0.05- 0.2 mg x dm(-2), 60 (17%) were from 0.2 to 0.8 mg x dm(-2) and 76 (22%) were from 0.8 to 3.3 mg x dm(-2). A total of 71 samples were then selected at random from the 143 packaging samples that contained benzophenone, and the food itself was analysed. Benzophenone was detected in 51 (72%) of the foods. Two food samples (3%) were in the range 0.01-0.05 mg kg(-1). A total of 29 (41%) were from 0.05 to 0.5 mg kg(-1), 17 (24%) were from 0.5 to 5 mg x kg(-1) and three (4%) food samples exceeded 5 mg x kg(-1). The highest level of benzophenone in food was 7.3 mg x kg(-1) for a high-fat chocolate confectionery product packaged in direct contact with cartonboard, with room temperature storage conditions and with a high contact area:food mass ratio. When the mass fraction of benzophenone migration was calculated for the different contact and storage regimes involved, the attenuation effects of indirect contact and of low temperature storage were cumulative. Thus, there was a sixfold reduction in migration for indirect contact compared with direct contact, a sixfold reduction for chilled/frozen storage compared with ambient storage, and 40-fold reduction for the two contact conditions combined.

Expression of NK2 homologous transcripts during zebrafish development.

Expression of NK2 homologous transcripts during Zebrafish development was investigated by in situ hybridization technique. NK2 mRNA expression was first detected in a cluster of cells at the embryonic shield stage, and subsequently in the heart field of the 5-8-somite embryo. By the 15-17 somite stages, NK2 expressing cells were revealed in the midline of the developing embryo, and by 48 hpf within the heart tube of the larva. By 72 hpf, NK2 transcripts appeared in the jaw bones, pharyngeal arches, the cranium with minimal expression in striated muscle.

A suggested outline for writing curriculum development journal articles: the IDCRD format.

BACKGROUND: During the past decade, medical school and residency faculty have been active in developing and revising curricula for medical education programs. Many of these curriculum development efforts ultimately are published in peer-reviewed professional journals as articles or abstracts. Unlike research publications, no uniform format currently exists for reporting curriculum development efforts in the peer-reviewed literature. SUMMARY: A suggested format for organizing curriculum development manuscripts consists of the introduction, development, curriculum, results, and discussion (IDCRD). Detailed descriptions of each section are discussed herein. CONCLUSIONS: The IDCRD manuscript outline is intended to provide useful guidance to medical educators in publishing their curriculum development efforts. Journal editors are encouraged to recognize the importance of providing uniform descriptions of curricula so that readers can benefit from the experience of others and replicate successful curriculum efforts.

Peptidases affecting recombinant protein production by Streptomyces lividans.

The influence of peptidases on human interleukin-3 (rhIL-3) production by a recombinant Streptomyces lividans strain was investigated. The bacterium produced several general peptidases and tripeptidyl peptidases compromising the authenticity of rhIL-3. The level of peptidases depended on growth morphology. Growing S. lividans as compact pellets successfully reduced peptidase activity. Maximum general peptidase activity in pellet culture was delayed after maximum rhIL-3 concentration was achieved. The activity of the tripeptidyl peptidase was product (rhIL-3) associated.

Cathepsin B and complement C3 are major comigrants in the estrogen-induced peroxidase fraction of rat uterine fluid.

The luminal fluid of estrogen or DES-stimulated uterus of immature rats contains 10-12 isoforms of peroxidase between pI 4.5-6.0. N-terminal amino acid sequencing of diaminobenzidine-peroxidase bands eluted from IEF and SDS-PAGE gels showed the presence of cathepsin B and the complement family of proteins as the major comigrants. Sequential treatment of uterine fluid by cation, anion, and size exclusion chromatography resulted in a five-fold purification of peroxidase having a specific activity of 273 units/mg. Mass spectrometric studies of bands isolated from SDS-PAGE gels from the size-exclusion purified peroxidase fraction showed the presence of complement C3 along with novel previously uncharacterized proteins. Two dimensional electrophoresis followed by N-terminal amino acid sequencing confirmed the presence of cathepsin B isoforms and isoforms of a novel protein at approximately 87 kDa. Identification by mass spectrometry from the database for this novel protein was inconclusive but could most likely be a candidate for estrogen-induced peroxidase. Results conclusively prove that cathepsin B and complement C3 are major proteins in the estrogen-induced peroxidase fraction of uterine fluid.

Ultrastructural differentiation of cardiomyocytes of the zebrafish during the 8-26-somite stages.

We report cellular hypertrophy, mitochondrial proliferation and differentiation, myofibrillogenesis, and junctional maturation in cardiac progenitor cells between the 8 and 26-somite stages of the zebrafish, Danio rerio. However, coordinated contraction in embryonic cardiomyocytes did not occur until 26-somite stage when 'developed' intercalated discs, rooted sarcomeres, and a well-established sarcoplasmic reticulum had differentiated.

A biomarker approach to measuring human dietary exposure to certain phthalate diesters.

Three groups of eight volunteers were administered stable isotope-labelled phthalate diesters in a single dose and the amount of the corresponding phthalate monoesters excreted in the urine was measured. Amongst the phthalates administered were the symmetrical dibutyl-, di-2-ethyl- and diisooctyl- phthalates along with the unsymmetrical benzylbutylphthalate. The control group received no dose, the low dose group received 168-255 microg of each phthalate and the high dose group received 336 to 510 microg of each phthalate. The excreted phthalate monoesters were measured by LC-MS following hydrolysis of conjugates. The bulk of phthalate monoester was excreted in the first 24 hour period following the dose. For dibutylphthalate, 64% and 73% on a mole basis of the low, and high dose respectively was excreted as monobutylphthalate. For dioctylphthalate (sum of the 2-ethylhexyl and the isooctyl species) the yield was 14 and 12% of the low and high dose excreted as monooctylphthalate. For benzylbutylphthalate, 67% and 78% was eliminated as monobenzylphthalate and only 6% (measured for the high dose only) was eliminated as monobutylphthalate. These conversion factors can be used in future studies to assess exposure to phthalate esters via measuring urinary levels of the monoester metabolites.

Fibronectin/fibroblast growth factor/cell matrix signaling pathways and reciprocal membrane interaction may be the regulators of cell growth and apoptosis in Trypanosoma musculi in co-cultures with fibroblasts.

Trypanosoma musculi cultivated in medium containing serum alone or in the absence of fibroblasts in vitro were transformed into rounded, immotile cells, incapable of division and infectivity. Only in close contact with fibroblasts could the parasites survive and grow indefinitely. This report established the identity of the splenic 'sustentacular' cells as fibroblasts and utilized immunocytochemistry to demonstrate the putative cytoskeletal and membrane-associated molecules that may be involved in the control of growth and division, and apoptosis of T. musculi in vitro. The results indicated that cells that reacted intensely for fibroblast growth factor (FGF) also displayed a complex cytoskeletal system of F-actin bands underlying the plasma membrane of the fibroblast cell body and its numerous processes. Among the cytoskeletal and membrane glycoproteins, fibronectin, I-CAM, laminin, occludin, vinculin and desmin were most prominent. Fibronectin was most highly enhanced on the cell membrane and deposited as 'finger prints or tracks' on the extracellular culture surfaces. Transmission and scanning electron microscopy confirmed the intimate contact between trypanosomes and fibroblasts, however, neither membrane fusion or junctions were apparent. Our results suggested that a fibroblast-derived, membrane-associated factor appeared to be the putative growth regulator and apoptosis inhibitor in co-cultures of spleen-derived fibroblasts and T. musculi.