Influenza is one of the most common human respiratory diseases, and represents a serious public health concern. However, the high mutability of influenza viruses has hampered vaccine development, and ...resistant strains to existing anti-viral drugs have also emerged. Novel anti-influenza therapies are urgently needed, and in this study, we describe the anti-viral properties of a Spirulina (Arthrospira platensis) cold water extract. Anti-viral effects have previously been reported for extracts and specific substances derived from Spirulina, and here we show that this Spirulina cold water extract has low cellular toxicity, and is well-tolerated in animal models at one dose as high as 5,000 mg/kg, or 3,000 mg/kg/day for 14 successive days. Anti-flu efficacy studies revealed that the Spirulina extract inhibited viral plaque formation in a broad range of influenza viruses, including oseltamivir-resistant strains. Spirulina extract was found to act at an early stage of infection to reduce virus yields in cells and improve survival in influenza-infected mice, with inhibition of influenza hemagglutination identified as one of the mechanisms involved. Together, these results suggest that the cold water extract of Spirulina might serve as a safe and effective therapeutic agent to manage influenza outbreaks, and further clinical investigation may be warranted.
Developing high performance and environment‐friendly fluoropolymers is greatly desired. In this work, we found that 2‐diazo‐1,1,1‐trifluoroethane can be polymerized by air‐stable alkyne‐palladium(II) ...catalysts following a living polymerization mechanism, affording a fluoropolymer, poly(trifluoromethyl methylene) in high yield with controlled molar mass and low dispersity. This polymer bears trifluoromethyl on every main chain atom and thus has good resistance to chemical corrosion, high hydrophobicity, and excellent dielectric constant with low dielectric loss. Due to the steric hindrance between the trifluoromethyl pendants, the synthetic poly(trifluoromethyl methylene) can twist into a stable helix. The one‐handed preferred helices synthesized using chiral PdII‐catalysts exhibit high optical activity and circularly polarized luminescence. Remarkably, such polymer can be completely degraded to (E)‐1,1,1,4,4,4‐hexafluorobut‐2‐ene at high temperatures (>280 °C). Additionally, taking advantage of the living chain end, the polymer can be further modified.
Living polymerization of 2‐diazo‐1,1,1‐trifluoroethane gives environmental friendly poly(trifluoromethylmethylene) in high yield with controllable molar mass and low dispersity, which twisted into stable helix with clear circularly polarized luminescence. The high fluorine content results in high hydrophobicity, good resistance to chemical corrosion, high dielectric constant with low dielectric loss.
Ali et al. proposed a physical (PHY) layer resource management for single-carrier N-antenna beamforming (BF) non-orthogonal multiple access (NOMA) systems. Cross PHY/application (APP) layer resource ...allocation and adaptive source encoding rate for single-antenna NOMA/ orthogonal frequency division multiple access (OFDMA) video communications was also recently proposed. These prior works did not deal with joint subcarrier/ BF cluster assignment in a cross-layer fashion. In this paper, we propose a joint adaptive source encoding rate and iterative cross-PHY/APP layer resource management for BF-NOMA-OFDMA video communications to support 2N users on one subcarrier and improves the average video quality peak-signal-to-noise ratio (PSNR). The proposed scheme outperforms Ali et al. PHY layer resource management by 4.18dB in the numerical results. Considering the high computational complexity of the iterative resource allocation, we further propose replacing the iterative cross-layer resource allocation by a supervised learning-based approach. We propose a novel and problem-specific post-processing procedure to guarantee the constraints that every user holds at least one subcarrier and a subcarrier support 2N users. The proposed supervised learning-based approach reduces the execution time by 98% in a GPU-based platform, comparable with 91-99% execution time reduction of supervised learning based communication algorithms in the literature, at the cost of 4% PSNR loss. Finally, we propose a supervised/unsupervised learning -based approach with minus PSNR as the cost function for continuous learning in an unsupervised learning fashion after supervised learning is done. The numerical results show that the proposed hybrid supervised/unsupervised learning approach can reduce the PSNR loss to just 1%.
People in Taiwan enjoy comprehensive National Health Insurance coverage. However, under the global budget constraint, hospitals encounter enormous challenges. This study was designed to examine ...Taiwan medical centers' efficiency and factors that influence it.
We obtained data from open sources of government routine publications and hospitals disclosed by law to the National Health Insurance Administration, Ministry of Health and Welfare, Taiwan. The dynamic data envelopment analysis (DDEA) model was adopted to estimate all medical centers' efficiencies during 2015-2018. Beta regression models were used to model the efficiency level obtained from the DDEA model. We applied an input-oriented approach under both the constant returns-to-scale (CRS) and variable returns-to-scale (VRS) assumptions to estimate efficiency.
The findings indicated that 68.4% (13 of 19) of medical centers were inefficient according to scale efficiency. The mean efficiency scores of all medical centers during 2015-2018 under the CRS, VRS, and Scale were 0.85, 0.930, and 0.95,respectively. Regression results showed that an increase in the population less than 14 years of age, assets, nurse-patient ratio and bed occupancy rate could increase medical centers' efficiency. The rate of emergency return within 3-day and patient self-pay revenues were associated significantly with reduced hospital efficiency (p < 0.05). The result also showed that the foundation owns medical center has the highest efficiency than other ownership hospitals.
The study results provide information for hospital managers to consider ways they could adjust available resources to achieve high efficiency.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Effects of five water/additive mists on explosion in closed vessel were compared.•Effects of additive type and mist concentration on explosion were investigated.•Corresponding relationship between ...flame propagation and pressure rise was studied.•Inhibition effect of explosion was related to additive radical and was confirmed.•Two accelerating rises of pressure was affected by additive type and mist amount.
The suppression effects of pure ultrafine water mist and 5% mass fraction alkali metal (NaCl, Na2CO3, KHCO3, KCl and K2CO3) solutions ultrafine water mist on methane explosion were conducted under five mist concentrations in a sealed visual vessel. Mist diameters of different additive solutions were measured by a phase doppler particle analyzer. Pressure data and dynamic flame pictures were recorded respectively by a high-frequency pressure sensor and a high-speed camera. Results indicate that alkali metal compound can enhance the suppression effect of ultrafine water mist and it was related to the additive type. The suppression order of alkali metal compound for methane explosion was K2CO3>KCl > KHCO3>Na2CO3>NaCl. Meanwhile, additive radicals can obviously affect explosion intensity and it mainly reflected in the reduction of explosion pressure under different mist conditions (K+>Na+, Cl− >HCO3−). The pressure generated from combustion wave accelerating propagation underwent two accelerating rises and was affected by additive type and mist amount. The effect of additive type on explosion intensity (maximum explosion overpressure (ΔPmax), two peak values of pressure rising rate) was similar with flame propagation velocity and were decreased evidently with increasing mist concentration. The enhancement in explosion suppression was due to the combination of improved physical and chemical effects.
Heavy metals (such as Zn and Pb) have a deactivation effect on the catalyst for selective catalytic reduction of NO with NH3. In this study, it was found that the modification of Mn/TiO2 catalyst by ...Nb could greatly enhance its Zn resistance. From the characterization results of BET, XRD, H2-TPR, NH3-TPD, it may be concluded that the introduction of Nb into Mn/TiO2 catalyst would lead to its lower crystallinity, more acid sites and higher concentrations of Mn4+ and surface chemisorbed oxygen. The results of in situ DRIFT study reveal that the NH3-SCR reactions over Mn/TiO2 and Mn-Nb/TiO2 all obey both the Langmuir-Hinshelwood mechanism and the Eley–Rideal mechanism, and the doping of Nb on Mn/TiO2 catalyst could promote the adsorption of NH3 and NOx species on it. All these features make a contribution to the high SCR activity and good Zn resistance of Mn-Nb/TiO2 catalyst.
•Mn-Nb/TiO2 catalyst has higher SCR activity and better Zn resistance than Mn/TiO2 catalyst.•The modification of Mn/TiO2 catalyst by Nb could promote the adsorption of NH3 species and NOx species.•The NH3-SCR reactions over Mn/TiO2 and Mn-Nb/TiO2 are all controlled by the L-H mechanism and the E–R mechanism.
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ObjectivesTo determine whether occupation type, distinguished by socioeconomic status (SES) and sedentary status, is associated with metabolic syndrome (MetS) risk.MethodsWe analysed two data sets ...covering 73 506 individuals. MetS was identified according to the criteria of the modified Adult Treatment Panel III. Eight occupational categories were considered: professionals, technical workers, managers, salespeople, service staff, administrative staff, manual labourers and taxi drivers; occupations were grouped into non-sedentary; sedentary, high-SES; and sedentary, non-high-SES occupations. A multiple logistic regression was used to determine significant risk factors for MetS in three age-stratified subgroups. R software for Windows (V.3.5.1) was used for all statistical analyses.ResultsMetS prevalence increased with age. Among participants aged ≤40 years, where MetS prevalence was low at 6.23%, having a non-sedentary occupation reduced MetS risk (OR=0.88, p<0.0295). Among participants aged >60 years, having a sedentary, high-SES occupation significantly increased (OR=1.39, p<0.0247) MetS risk.ConclusionsThe influence of occupation type on MetS risk differs among age groups. Non-sedentary occupations and sedentary, high-SES occupations decrease and increase MetS risk, respectively, among younger and older adults, respectively. Authorities should focus on individuals in sedentary, high-SES occupations.
The cobia Rachycentron canadum, mainly distributed in the warm waters of tropical and subtropical regions around the world, remains a fish of considerable economic importance. Detailed diversity and ...the number of microsatellite sequences in the cobia genome are still unintelligible. The primary aim of this work was to identify and quantify the miscellaneous SSR sequences in the cobia genome. More than 280,000 sequences were sequenced and screened using next‐generation sequencing technology and microsatellite identification. Perfect mononucleotide repeats, dinucleotide microsatellites, and trinucleotide microsatellites contain (A)10/(T)10, (AC)6/(TG)6, and (AAT)5–32 as the largest number of motifs in each type of microsatellite, respectively. The tetranucleotide and pentanucleotide microsatellites (TTM and PTM) consist of the largest number of motifs of both (ATCT)5–32 and (TCAT)5–31 in TTMs, and (CTCTC)5–9 in PTMs, whereas the hexanucleotide microsatellites are rarely observed in the cobia genome. All c. 38000 sequences of composite microsatellites are extremely diverse, including compound (11.71%), interrupted compound (71.77%), complex (0.45%), and interrupted complex (16.07%). In this study, we developed a convenient and useful recording system for writing down and categorizing diverse composite microsatellite types. This system will provide great support for exploring repeat origins, evolutionary mechanisms, and the application of polymorphic microsatellites.
Increasing the density of Fe–N4 sites in Fe–N–C materials is pivotal for enhancing the kinetics of the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Fe utilization ...is a vital parameter for the Fe–N–C catalyst evaluation, but it shows a tendency to decrease with increasing density of the Fe–N4 sites. Herein, dense edge Fe–N2+2 sites are deposited in the outermost and subsurface layers of a surface-rich pyridinic-N carbon substrate (Feg–NC/Phen). We have demonstrated that the surface-rich pyridinic-N carbon substrate is more favorable to form surface Fe–N2+2 sites with superior intrinsic activity. The surface Fe–N4 sites can improve both the site density and Fe utilization, while shortening the transport pathways of protons and O2 effectively. By means of these structural advantages, Feg–NC/Phen can exhibit a high current density of 0.046 A cm−2@0.9 ViR-free and a high peak power density (Pmax) of 1.53 W cm−2 in 2 bar H2–O2 PEMFCs, and outperform almost all the reported M–N–C catalysts. This outstanding performance will inspire relevant research in the distribution of active sites. Moreover, it requires particular attention to obtain a viable solution to performance durability in fuel cells.
The electrochemical properties and potential applications of a composite solid electrolyte (CSE) named array-CSE, consisting of a Li
6.4
La
3
Zr
1.4
Ta
0.6
O
12
(LLZTO) array structure embedded in a ...poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix, have been investigated. The LLZTO array is fabricated using the innovative three-dimensional printing technique, enabling precise control over its architecture. In comparison to the conventional composite electrolyte containing distributed LLZTO particles in PVDF-HFP, referred to as dispersion-CSE, the array-CSE demonstrates efficient Li
+
migration along a continuous ceramic pathway, while the dispersion-CSE shows inefficient Li
+
transport due to indirect trajectories. Experimental results confirm higher Li
+
conductivity, lower activation energy, and a higher Li
+
transference number in the array-CSE than in the dispersion-CSE. Through numerical simulations, the Li
+
transport behaviors and fluxes across the individual LLZTO and PVDF-HFP regions within the CSE are clarified, and the difference in the Li
+
fluxes between the array-CSE and dispersion-CSE is revealed, which is consistent with the experimental findings. When assembled into LiFePO
4
batteries, the array-CSE demonstrates superior capacity and rate performance, as well as a longer cycle life. These advantages can be attributed to its enhanced conductivity and reduced void formation at the anode interface during Li stripping. These findings offer valuable insights for the design of CSEs in solid-state Li-ion batteries, with the potential for increased energy density and stability.
An innovative composite solid electrolyte (CSE) enhances Li
+
transport efficiency by integrating an array of ceramic pillars into a polymer matrix, as compared to conventional CSEs with dispersed ceramic particles.
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