Preparation and physicochemical characterization of films prepared with salmon skin gelatin extracted by a trypsin-aided process

The recovery of gelatins from Atlantic salmon (Salmo salar) skin for film formation and characterization was studied. Fish skins pre-treated with trypsin (250 U/g) produced the highest hydroxyproline content (7.41 ± 0.49 mg hydroxyproline/g treated skin) and yield (53.05 ± 4.38%) of gelatin, as compared to the use of saline solution. Pre-treatment with a lower concentration of trypsin (1 U/g) at a shorter pre-treatment time successfully reduced the degradation of gelatin with co-production of high molecular weight α-chains. Gelatin was further extracted by a trypsin-aided process for film formation and characterization. Films with increasing protein concentration (from 1 to 5%, w/v) exhibited higher thickness, tensile strength, and elongation at break (EAB), but a marked decrease in EAB for films with 6 and 7% (w/v). Films with 5% proteins showed higher thickness, lower tensile strength and higher EAB with increasing concentrations of glycerol (from 10 to 50% of proteins, w/w). All films exhibited high water uptake, decrease in light transmission and an increase in opacity as the protein and glycerol contents increased. Electrophoretic studies showed that the increase in the mechanical properties of the films was correlated with the increase in protein concentration, owing to the increased content of high molecular weight chain fractions. Furthermore, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed the interaction between the proteins and glycerol for all films. This study demonstrated the viability of the trypsin supplementation process to obtain salmon skin gelatin for film formation

NGC 5291: Implications for the Formation of Dwarf Irregular Galaxies

The possible formation and evolution of dwarf irregular galaxies from material derived from perturbed evolved galaxies is addressed via an HI study of a likely example, the peculiar system NGC 5291. This system, located in the western outskirts of the cluster Abell 3574, contains the lenticular galaxy NGC 5291 which is in close proximity to a disturbed companion and is flanked by an extensive complex of numerous knots extending roughly 4\u27 north and 4\u27 south of the galaxy. In an initial optical and radio study, Longmore et al. (1979, MNRAS, 188, 285) showed that these knots have the spectra of vigorous star-forming regions, and suggested that some may in fact be young dwarf irregular galaxies. High resolution 21-cm line observations taken with the VLA are presented here and reveal that the H I distribution associated with this system encompasses not only the entire N-S complex of optical knots, but also forms an incomplete ring or tail that extends approximately 3\u27 to the west. The HI associated with NGC 5291 itself shows a high velocity range; the Seashell is not detected. The formation mechanism for this unusual system is unclear and two models-a large, low-luminosity ram-swept disk, and a ram-swept interaction-are discussed. The HI in the system contains numerous concentrations, mostly along the N-S arc of the star-forming complexes, which generally coincide with one or more optical knots; the larger HI features contain several X 109 M0 of gas. Each of the knots is compared to a set of criteria designed to determine if these objects are bound against their own internal kinetic energy and are tidally stable relative to the host galaxy. An analysis of the properties of the H I concentrations surrounding the optical star-forming complexes indicates that at least the largest of these is a bound system; it also possesses a stellar component. It is suggested that this object is a genuinely young dwarf irregular galaxy that has evolved from the material associated with the system and that this entire complex contains several proto- or young dwarf irregular galaxies in various stages of development. We are therefore witnessing the early evolution of a number of genuinely young galaxies. Given the evident importance of the NGC 5291 system as a \u27\u27nursery\u27\u27 for young galaxies, careful modeling is required if we are to understand this remarkable galaxy

Effects of Lactobacillus rhamnosus GG supplementation on cow's milk allergy in a mouse model

<p>Abstract</p> <p>Background</p> <p>Cow's milk allergy (CMA) is one of the most prevalent human food-borne allergies, particularly in infants and young children from developed countries. Our study aims to evaluate the effects of <it>Lactobacillus rhamnosus </it>GG (LGG) administration on CMA development using whole cow's milk proteins (CMP) sensitized Balb/C mice by two different sensitization methods.</p> <p>Methods</p> <p>LGG supplemented mice were either sensitized orally with CMP and cholera toxin B-subunit (CTB) as adjuvant, or intraperitoneally (IP) with CMP but without the adjuvant. Mice were then orally challenged with CMP and allergic responses were accessed by monitoring hypersensitivity scores, measuring the levels of CMP-specific immunoglobulins (IgG1, IgG2a and IgG) and total IgE from sera, and cytokines (IL-4 and IFN-γ) from spleen lysates.</p> <p>Results</p> <p>Sensitization to CMP was successful only in IP sensitized mice, but not in orally sensitized mice with CMP and CTB. Interestingly, LGG supplementation appeared to have reduced cow's milk allergy (CMA) in the IP group of mice, as indicated by lowered allergic responses.</p> <p>Conclusions</p> <p>Adjuvant-free IP sensitization with CMP was successful in inducing CMA in the Balb/C mice model. LGG supplementation favourably modulated immune reactions by shifting Th2-dominated trends toward Th1-dominated responses in CMP sensitized mice. Our results also suggest that oral sensitization by the co-administration of CMP and CTB, as adjuvant, might not be appropriate to induce CMA in mice.</p

Salmon skin gelatin-corn zein composite films produced via crosslinking with glutaraldehyde: Optimization using response surface methodology and characterization

Composite films comprised of salmon (Salmo salar) skin gelatin and zein were prepared via crosslinking with glutaraldehyde. Response surface methodology (RSM) was used to optimize film composition to maximize tensile strength (TS) and elongation at break (EAB), and to minimize water solubility (WS) of the films. The significant (P < 0.05) variables affecting film properties were: glutaraldehyde for TS, and zein and glutaraldehyde for both EAB and WS. The optimum concentrations (g/mL) to maximize TS and EAB and to minimize WS were 3% zein and 0.02% glutaraldehyde, which yielded films having a TS of 3.11 ± 0.01 MPa, EAB of 22.43 ± 1.57%, and WS of 38.82 ± 1.71%. The infrared spectra and morphological analyses demonstrated that the gelatin-zein composite film was successfully crosslinked after the addition of glutaraldehyde, with the formation of crosslinked networks between proteins and a denser packed organization of proteins. Consequently, the resultant crosslinked composite film exhibited improvement on light transparency, water resistance and mechanical strength as a function of increasing humidity

Star formation towards the Scutum tangent region and the effects of Galactic environment

By positional matching to the catalogue of Galactic Ring Survey molecular clouds, we have derived distances to 793 Bolocam Galactic Plane Survey (BGPS) sources out of a possible 806 located within the region defined by Galactic longitudes l = 28.5 degr to 31.5 degr and latitudes |b| < 1 degr. This section of the Galactic Plane contains several major features of Galactic structure at different distances, mainly mid-arm sections of the Perseus and Sagittarius spiral arms and the tangent of the Scutum-Centarus arm, which is coincident with the end of the Galactic Long Bar. By utilising the catalogued cloud distances plus new kinematic distance determinations, we are able to separate the dense BGPS clumps into these three main line-of-sight components to look for variations in star-formation properties that might be related to the different Galactic environments. We find no evidence of any difference in either the clump mass function or the average clump formation efficiency (CFE) between these components that might be attributed to environmental effects on scales comparable to Galactic-structure features. Despite having a very high star-formation rate, and containing at least one cloud with a very high CFE, the star formation associated with the Scutum-Centarus tangent does not appear to be in any way abnormal or different to that in the other two spiral-arm sections. Large variations in the CFE are found on the scale of individual clouds, however, which may be due to local triggering agents as opposed to the large-scale Galactic structure.Comment: 11 pages, 8 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Societ

Ambient air quality in the Kathmandu Valley, Nepal, during the pre-monsoon: Concentrations and sources of particulate matter and trace gases

The Kathmandu Valley in Nepal is a bowl-shaped urban basin that experiences severe air pollution that poses health risks to its 3.5 million inhabitants. As part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE), ambient air quality in the Kathmandu Valley was investigated from 11 to 24 April 2015, during the premonsoon season. Ambient concentrations of fine and coarse particulate matter (PM2:5 and PM10, respectively), online PM1, inorganic trace gases (NH3, HNO3, SO2, and HCl), and carbon-containing gases (CO2, CO, CH4, and 93 nonmethane volatile organic compounds; NMVOCs) were quantified at a semi-urban location near the center of the valley. Concentrations and ratios of NMVOC indicated origins primarily from poorly maintained vehicle emissions, biomass burning, and solvent/gasoline evaporation. During those 2 weeks, daily average PM2:5 concentrations ranged from 30 to 207 μ g m-3, which exceeded the World Health Organization 24 h guideline by factors of 1.2 to 8.3. On average, the nonwater mass of PM2:5 was composed of organic matter (48 %), elemental carbon (13 %), sulfate (16 %), nitrate (4 %), ammonium (9 %), chloride (2 %), calcium (1 %), magnesium (0.05 %), and potassium (1 %). Large diurnal variability in temperature and relative humidity drove corresponding variability in aerosol liquid water content, the gas-aerosol phase partitioning of NH3, HNO3, and HCl, and aerosol solution pH. The observed levels of gas-phase halogens suggest that multiphase halogen-radical chemistry involving both Cl and Br impacted regional air quality. To gain insight into the origins of organic carbon (OC), molecular markers for primary and secondary sources were quantified. Levoglucosan (averaging 1230±1154 ng m-3), 1,3,5-triphenylbenzene (0:8± 0:6 ng m-3), cholesterol (2:9±6:6 ng m-3), stigmastanol (1.0 ±0:8 ng m-3), and cis-pinonic acid (4:5 ± 1:9 ng m-3) indicate contributions from biomass burning, garbage burning, food cooking, cow dung burning, and monoterpene secondary organic aerosol, respectively. Drawing on source profiles developed in NAMaSTE, chemical mass balance (CMB) source apportionment modeling was used to estimate contributions to OC from major primary sources including garbage burning (18 ± 5 %), biomass burning (17 ± 10 %) inclusive of open burning and biomass-fueled cooking stoves, and internal-combustion (gasoline and diesel) engines (18±9 %). Model sensitivity tests with newly developed source profiles indicated contributions from biomass burning within a factor of 2 of previous estimates but greater contributions from garbage burning (up to three times), indicating large potential impacts of garbage burning on regional air quality and the need for further evaluation of this source. Contributions of secondary organic carbon (SOC) to PM2:5 OC included those originating from anthropogenic precursors such as naphthalene (10 ± 4 %) and methylnaphthalene (0:3 ± 0:1 %) and biogenic precursors for monoterpenes (0:13 ± 0:07 %) and sesquiterpenes (5 ± 2 %). An average of 25 % of the PM2.5 OC was unapportioned, indicating the presence of additional sources (e.g., evaporative and/or industrial emissions such as brick kilns, food cooking, and other types of SOC) and/or underestimation of the contributions from the identified source types. The source apportionment results indicate that anthropogenic combustion sources (including biomass burning, garbage burning, and fossil fuel combustion) were the greatest contributors to PM2:5 and, as such, should be considered primary targets for controlling ambient PM pollution

Generating a taxonomy for genetic conditions relevant to reproductive planning

As genome or exome sequencing (hereafter genome-scale sequencing) becomes more integrated into standard care, carrier testing is an important possible application. Carrier testing using genome-scale sequencing can identify a large number of conditions, but choosing which conditions/genes to evaluate as well as which results to disclose can be complicated. Carrier testing generally occurs in the context of reproductive decision-making and involves patient values in a way that other types of genetic testing may not. The Kaiser Permanente Clinical Sequencing Exploratory Research program is conducting a randomized clinical trial of preconception carrier testing that allows participants to select their preferences for results from among broad descriptive categories rather than selecting individual conditions. This paper describes 1) the criteria developed by the research team, the return of results committee (RORC), and stakeholders for defining the categories; 2) the process of refining the categories based on input from patient focus groups and validation through a patient survey; and, 3) how the RORC then assigned specific gene-condition pairs to taxonomy categories being piloted in the trial. The development of four categories (serious, moderate/mild, unpredictable, late onset) for sharing results allows patients to select results based on their values without separately deciding their interest in knowing their carrier status for hundreds of conditions. A fifth category, lifespan limiting, was always shared. The lessons learned may be applicable in other results disclosure situations, such as incidental findings

Characteristics and outcome of infants with candiduria in neonatal intensive care - a Paediatric Investigators Collaborative Network on Infections in Canada (PICNIC) study

<p>Abstract</p> <p>Background</p> <p>There is limited information in the literature on the presentation and prognosis of candidal urinary tract infection (UTI) in infants in the neonatal intensive care unit (NICU).</p> <p>Methods</p> <p>This was a prospective cohort study performed in 13 Canadian NICUs. Infants with candidal UTI without extra-renal candidal infection at presentation were enrolled.</p> <p>Results</p> <p>Thirty infants fit the study criteria. Median birth weight and gestational age were 2595 grams (range 575-4255) and 35 weeks (range 24-41) with 10 infants being < 30 weeks gestation. The most common primary underlying diagnosis was congenital heart disease (n = 10). The median age at initial diagnosis was 16 days (range 6-84 days). Renal ultrasonography findings were compatible with possible fungal disease in 15 of the 26 infants (58%) in whom it was performed. Treatment was variable, but fluconazole and either amphotericin B deoxycholate or lipid-based amphotericin B in combination or sequentially were used most frequently. Extra-renal candidiasis subsequently developed in 4 infants. In 2 of these 4 infants, dissemination happened during prolonged courses of anti-fungal therapy. Three of 9 deaths were considered to be related to candidal infection. No recurrences of candiduria or episodes of invasive candidiasis following treatment were documented.</p> <p>Conclusion</p> <p>Candidal UTI in the NICU population occurs both in term infants with congenital abnormalities and in preterm infants, and is associated with renal parenchymal disease and extra-renal dissemination. A wide variation in clinical approach was documented in this multicenter study. The overall mortality rate in these infants was significant (30%). In one third of the deaths, <it>Candida </it>infection was deemed to be a contributing factor, suggesting the need for antifungal therapy with repeat evaluation for dissemination in infants who are slow to respond to therapy.</p