16 research outputs found

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

    Effects of H2S Loading Rate on the Performance of Reactive Absorption with Electrochemical Oxidation

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    The odor released from environmental facilities is recognized as a major problem in environmental industries. In this study, reactive absorption, using an electrolyzed water solution (electrolyzed water scrubber, EWS), was developed to treat the odorous gases H2S and NH3, which are representative odorous substances. In addition, a numerical model composed of mass transfer coefficients and zero-order kinetic constants was established to predict the performance of EWS. The model was verified through experiments and data fittings. In the experiments, the concentration of H2S varied from 500 to 2000 ppm, while NH3 was fixed at 500 ppm. The results revealed that the H2S removal rate varied depending on the inlet H2S concentration, but no changes were observed for NH3. The numerical model appropriately described the experimental results to further predict the performance of EWS. The model prediction results for the shock loading of H2S indicated that a 100% removal rate can be achieved by increasing the current density to 70 mA cm−2 or higher. Finally, the EWS can be used to reduce the odor, owing to its flexible operation that responds to fluctuating loading rates

    Quantitative Analysis of Biogenic Amines in Different Cheese Varieties Obtained from the Korean Domestic and Retail Markets

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    To evaluate the safety and risk assessment of cheese consumption in the Republic of Korea, sixty cheese samples purchased from the farmstead and retails markets (imported) were analyzed for their biogenic amine (BA) contents. The BA profiles and quantities of eight amines (tryptamine, 2-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) were determined using high-performance liquid chromatography (HPLC). Spermine was the only amine detectable in all the samples. The BAs of fresh cheeses from both farmstead and retail markets were mostly undetectable, and comparatively at lower levels (<125 mg/kg) than ripened samples. Putrescine was undetectable in all the domestic ripened cheeses. The sum of BA levels in the imported ripened cheeses of Pecorino Romano (1889.75 mg/kg) and Grana Padano (1237.80 mg/kg) exceeds >1000 mg/kg, of which histamine accounts nearly 86 and 77% of the total levels, respectively. The tolerable limits of the potential toxic amines, histamine and tyramine surpassed in four and three imported ripened samples, respectively. Furthermore, the presence of potentiators (putrescine and cadaverine) together in samples even with a lower level of toxic amines alarms the risk in consumption. Therefore, adoption of strict hygienic practices during the entire chain of cheese production, along with obligatory monitoring and regulation of BA in cheeses seems to be mandatory to ensure the safety of the consumers

    Application of Whey Protein-Based Edible Films and Coatings in Food Industries: An Updated Overview

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    The recent surge in environmental awareness and consumer demand for stable, healthy, and safe foods has led the packaging and food sectors to focus on developing edible packaging materials to reduce waste. Edible films and coatings as a modern sustainable packaging solution offer significant potential to serve as a functional barrier between the food and environment ensuring food safety and quality. Whey protein is one of the most promising edible biopolymers in the food packaging industry that has recently gained much attention for its abundant nature, safety, and biodegradability and as an ecofriendly alternative of synthetic polymers. Whey protein isolate and whey protein concentrate are the two major forms of whey protein involved in the formation of edible films and coatings. An edible whey film is a dry, highly interacting polymer network with a three-dimensional gel-type structure. Films/coatings made from whey proteins are colorless, odorless, flexible, and transparent with outstanding mechanical and barrier properties compared with polysaccharide and other-protein polymers. They have high water vapor permeability, low tensile strength, and excellent oxygen permeability compared with other protein films. Whey protein-based films/coatings have been successfully demonstrated in certain foods as vehicles of active ingredients (antimicrobials, antioxidants, probiotics, etc.), without considerably altering the desired properties of packaging films that adds value for subsequent industrial applications. This review provides an overview of the recent advances on the formation and processing technologies of whey protein-based edible films/coatings, the incorporation of additives/active ingredients for improvement, their technological properties, and potential applications in food packaging

    Tablet PC-based competency evaluation for nursing students in three Asian countries: Cross-sectional comparative study

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    Aim: This study evaluated a practical competency evaluation for nursing students in three Asian countries using tablet PC-based tests. The need to evaluate practical competencies in a non-face-to-face manner continues to pose challenges in nursing education. Design: This study presents descriptive comparative research on a tablet PC-based evaluation of practical competencies in three countries. Methods: tablet PC-based clinical practice competency evaluation was conducted among nursing college students in Korea, Vietnam and Mongolia. In total, 124 students answered 65 questions for practical competency evaluation and items on its usefulness. Results: Students from Korea had the highest score of nursing competencies (41.6 points; n = 59, SD 6.02), followed by those from Vietnam (26.3 points; n = 30, SD 4.97) and Mongolia (18.4 points; n = 35, SD 5.36). Scores for usability showed an inverse relationship with competency scores. Questions incorporating video showed the lowest proportion of low-discrimination items. Conclusions: This research recognized that using video which provides contextual elements can increase item discrimination. These findings suggest that incorporating video into evaluation items in tablet-PC-based tests is useful for international comparison.N

    Probiogenomic In-Silico Analysis and Safety Assessment of <i>Lactiplantibacillus plantarum</i> DJF10 Strain Isolated from Korean Raw Milk

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    The whole genome sequence of Lactiplantibacillus plantarum DJF10, isolated from Korean raw milk, is reported, along with its genomic analysis of probiotics and safety features. The genome consists of 29 contigs with a total length of 3,385,113 bp and a GC content of 44.3%. The average nucleotide identity and whole genome phylogenetic analysis showed the strain belongs to Lactiplantibacillus plantarum with 99% identity. Genome annotation using Prokka predicted a total of 3235 genes, including 3168 protein-coding sequences (CDS), 59 tRNAs, 7 rRNAs and 1 tmRNA. The functional annotation results by EggNOG and KEGG showed a high number of genes associated with genetic information and processing, transport and metabolism, suggesting the strain’s ability to adapt to several environments. Various genes conferring probiotic characteristics, including genes related to stress adaptation to the gastrointestinal tract, biosynthesis of vitamins, cell adhesion and production of bacteriocins, were identified. The CAZyme analysis detected 98 genes distributed under five CAZymes classes. In addition, several genes encoding carbohydrate transport and metabolism were identified. The genome also revealed the presence of insertion sequences, genomic islands, phage regions, CRISPR-cas regions, and the absence of virulence and toxin genes. However, the presence of hemolysin and antibiotic-resistance-related genes detected in the KEGG search needs further experimental validation to confirm the safety of the strain. The presence of two bacteriocin clusters, sactipeptide and plantaricin J, as detected by the BAGEL 4 webserver, confer the higher antimicrobial potential of DJF10. Altogether, the analyses in this study performed highlight this strain’s functional characteristics. However, further in vitro and in vivo studies are required on the safety assurance and potential application of L. plantarum DJF10 as a probiotic agent

    A strategy to promote the convenient storage and direct use of polyhydroxybutyrate-degrading Bacillus sp. JY14 by lyophilization with protective reagents

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    Abstract Background Bioplastics are attracting considerable attention, owing to the increase in non-degradable waste. Using microorganisms to degrade bioplastics is a promising strategy for reducing non-degradable plastic waste. However, maintaining bacterial viability and activity during culture and storage remains challenging. With the use of conventional methods, cell viability and activity was lost; therefore, these conditions need to be optimized for the practical application of microorganisms in bioplastic degradation. Therefore, we aimed to optimize the feasibility of the lyophilization method for convenient storage and direct use. In addition, we incoporated protective reagents to increase the viability and activity of lyophilized microorganisms. By selecting and applying the best protective reagents for the lyophilization process and the effects of additives on the growth and PHB-degrading activity of strains were analyzed after lyophilization. For developing the lyophilization method for protecting degradation activity, it may promote practical applications of bioplastic-degrading bacteria. Results In this study, the polyhydroxybutyrate (PHB)-degrading strain, Bacillus sp. JY14 was lyophilized with the use of various sugars as protective reagents. Among the carbon sources tested, raffinose was associated with the highest cell survival rate (12.1%). Moreover, 7% of raffionose showed the highest PHB degradation yield (92.1%). Therefore, raffinose was selected as the most effective protective reagent. Also, bacterial activity was successfully maintained, with raffinose, under different storage temperatures and period. Conclusions This study highlights lyophilization as an efficient microorganism storage method to enhance the applicability of bioplastic-degrading bacterial strains. The approach developed herein can be further studied and used to promote the application of microorganisms in bioplastic degradation

    Outcomes of Completion Lobectomy for Locoregional Recurrence after Sublobar Resection in Patients with Non-small Cell Lung Cancer

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    Background: This retrospective study aimed to determine the treatment patterns and the surgical and oncologic outcomes after completion lobectomy (CL) in patients with locoregionally recurrent stage I non-small cell lung cancer (NSCLC) who previously underwent sublobar resection. Methods: Data from 36 patients who initially underwent sublobar resection for clinical, pathological stage IA NSCLC and experienced locoregional recurrence between 2008 and 2016 were analyzed. Results: Thirty-six (3.6%) of 1,003 patients who underwent sublobar resection for NSCLC experienced locoregional recurrence. The patients’ median age was 66.5 (range, 44–77) years at the initial operation, and 28 (77.8%) patients were men. Six (16.7%) patients underwent segmentectomy and 30 (83.3%) underwent wedge resection as the initial operation. The median follow-up from the initial operation was 56 (range, 9–150) months. Ten (27.8%) patients underwent CL, 22 (61.1%) underwent non-surgical treatments (chemotherapy, radiation, concurrent chemoradiation therapy), and 4 (11.1%) did not receive treatment or were lost to follow-up after recurrence. Patients who underwent CL experienced no significant complications or deaths. The median follow-up time after CL was 64.5 (range, 19–93) months. The 5-year overall survival (OS) and post-recurrence survival (PRS) were higher in the surgical group than in the non-surgical (p<0.001) and no-treatment groups (p<0.001). Conclusion: CL is a technically demanding but safe procedure for locoregionally recurrent stage I NSCLC after sublobar resection. Patients who underwent CL had better OS and PRS than patients who underwent non-surgical treatments or no treatments; however, a larger cohort study and long-term surveillance are necessary

    Photosensitive ion channels in layered MXene membranes modified with plasmonic gold nanostars and cellulose nanofibers

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    Artificial ion channels are in demand for ionotronic devices. Here, the authors use layered MXene membranes modified with plasmonic gold nanostars and cellulose nanofibers to convert a thermal gradient into an ion current for photosensitive ion channeling. Ion channels transduce external stimuli into ion-transport-mediated signaling, which has received considerable attention in diverse fields such as sensors, energy harvesting devices, and desalination membrane. In this work, we present a photosensitive ion channel based on plasmonic gold nanostars (AuNSs) and cellulose nanofibers (CNFs) embedded in layered MXene nanosheets. The MXene/AuNS/CNF (MAC) membrane provides subnanometer-sized ionic pathways for light-sensitive cationic flow. When the MAC nanochannel is exposed to NIR light, a photothermal gradient is formed, which induces directional photothermo-osmotic flow of nanoconfined electrolyte against the thermal gradient and produces a net ionic current. MAC membrane exhibits enhanced photothermal current compared with pristine MXene, which is attributed to the combined photothermal effects of plasmonic AuNSs and MXene and the widened interspacing of the MAC composite via the hydrophilic nanofibrils. The MAC composite membranes are envisioned to be applied in flexible ionic channels with ionogels and light-controlled ionic circuits
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