Online monitoring concentrations of PM at five sites were obtained from 01/01/2016 to 31/12/2016 in Laiwu, China, and PM
filters were manually sampled for total 34 days at the same sites in four ...seasons in 2016. PM pollution sources, including soil dust, urban dust, construction dust, coal-fired power plants dust, steel plant dust and motor vehicle exhaust dust were sampled, respectively. The overall mean PM
/PM
ratio (0.57) in Laiwu was at a relatively lower level compared with that in other Chinese cities, which was higher in winter, indicating fine particulate was the main contributor of atmospheric pollution in this period. NH
mainly existed in the form of NH
NO
and (NH
)
SO
during the sampling periods. Higher sulfate and NH
concentrations were in summer while higher nitrate concentrations prevailed in winter. The annual value of OC/EC was (5.38 ± 1.70), higher in summer and lower in winter, and the calculated SOC/OC value (%) was (43.68 ± 12.98)%. The characteristic components were Si, Fe and Ca in urban dust and soil dust; Ca, Mg, and NH
in construction dust; Fe, Ca and SO
in steel dust; OC, EC and Si in motor vehicle exhaust dust; SO
, Al and NH
in power plant dust. Compared with other cities at home and abroad, it was found that the concentrations of metal elements in Laiwu were significantly higher than those in foreign cities, and at a medium level in China. With the improved CRAESCMB model, the urban dust was regarded as the receptor and the source of PM
and apportioned its secondary sources contributions to PM
. The CMB results showed the contributions of secondary sources including sulfate (17%), nitrate (17%) and SOC (13%) to PM
accounted for nearly half of all sources. Therefore, more attentions should be paid on secondary sources from the primary emission sources of the motor vehicle exhaust, coal combustion sources especially.
Treatment of severe Coronavirus Disease 2019 (COVID-19) is challenging. We performed a phase 2 trial to assess the efficacy and safety of human umbilical cord-mesenchymal stem cells (UC-MSCs) to ...treat severe COVID-19 patients with lung damage, based on our phase 1 data. In this randomized, double-blind, and placebo-controlled trial, we recruited 101 severe COVID-19 patients with lung damage. They were randomly assigned at a 2:1 ratio to receive either UC-MSCs (4 × 10
cells per infusion) or placebo on day 0, 3, and 6. The primary endpoint was an altered proportion of whole lung lesion volumes from baseline to day 28. Other imaging outcomes, 6-minute walk test (6-MWT), maximum vital capacity, diffusing capacity, and adverse events were recorded and analyzed. In all, 100 COVID-19 patients were finally received either UC-MSCs (n = 65) or placebo (n = 35). UC-MSCs administration exerted numerical improvement in whole lung lesion volume from baseline to day 28 compared with the placebo (the median difference was -13.31%, 95% CI -29.14%, 2.13%, P = 0.080). UC-MSCs significantly reduced the proportions of solid component lesion volume compared with the placebo (median difference: -15.45%; 95% CI -30.82%, -0.39%; P = 0.043). The 6-MWT showed an increased distance in patients treated with UC-MSCs (difference: 27.00 m; 95% CI 0.00, 57.00; P = 0.057). The incidence of adverse events was similar in the two groups. These results suggest that UC-MSCs treatment is a safe and potentially effective therapeutic approach for COVID-19 patients with lung damage. A phase 3 trial is required to evaluate effects on reducing mortality and preventing long-term pulmonary disability. (Funded by The National Key R&D Program of China and others. ClinicalTrials.gov number, NCT04288102.
The development of Pt-based core/shell nanoparticles represents an emerging class of electrocatalysts for fuel cells, such as methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). ...Here, we present a one-pot synthesis approach to prepare hexagonal PtBi/Pt core/shell nanostructure composed of an intermetallic Pt
1
Bi
1
core and an ultrathin Pt shell with well-defined shape, size, and composition. The structure and the synergistic effect among different components enhanced their MOR and EOR performance. The optimized Pt
2
Bi nanoplates exhibit excellent mass activities in both MOR (4,820 mA·mgPt
–1
) and EOR (5,950 mA·mgPt
–1
) conducted in alkaline media, which are 6.15 times and 8.63 times higher than those of commercial Pt/C, respectively. Pt
2
Bi nanoplates also show superior operation durability to commercial Pt/C. This work may inspire the rational design and synthesis of Pt-based nanoparticles with improved performance for fuel cells and other applications.
Using the theoretical perspective of market stakeholders, we analyze the impact of external innovations from upstream enterprises, downstream enterprises, and competitors on the exports of private ...enterprises. By using data from the China Industrial Enterprises Database, we find that external innovations from upstream suppliers, downstream customers and horizontal competitors show positive impacts on the export propensity, intensity and scale for private enterprises. The results of a heterogeneity analysis indicate that the positive relationships between the external innovations of stakeholders and the exports of private enterprises are stable in different factor-intensive industries. In addition, while the exports of private enterprises are positively correlated with their external innovations in the eastern and central regions, this relationship is not significant in the western region. Further, the mechanism analysis confirms that enterprise innovation played an important mediating role for the external innovations of stakeholders to promote the exports of private enterprises. This study provides useful policy implications for enhancing the export competitiveness of private enterprises.
Intramuscular fat (IMF) is an important factor affecting meat quality, but lipid and metabolic profiles of donkey meat remain unclear. The present study was conducted to investigate lipid ...characteristics in different parts of Dezhou donkey using lipidomics. The results show that IMF was more abundant in longissimus dorsi muscle (LDM) than rump muscle (RM) and hamstring muscle (HM), and mainly composed of triglycerides (TGs) rich in saturated fatty acid (SFAs) and monounsaturated fatty acid (MUFAs). A total of 1143 lipids belonging to 14 subclasses were identified in donkey meat, of which 73 lipids (23 upregulated and 50 downregulated) including glycerolipids (GLs), glycerophospholipids (GPs) and sphingolipids (SPs) were significantly different and are therefore potential biomarkers in LDM versus RM versus HM analyses (variable importance in projection >1, p < 0.05). Notably, 21 TGs upregulated in LDM were rich in MUFAs at sn‐1 and SFAs at 2 and 3 positions of TG. Donkey muscle accumulated far more SFAs at the sn‐3 position of TG, while more SFAs were present at the sn‐1 positions of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), and the percentages of SFAs at the three positions in TG, PC, and PE in the LDM group were much higher. The abundance of MUFAs at the sn‐2 positions of TG, PC, and PE was significantly greater than in sn‐1 or 3 positions, and the percentages of 18:1n‐9 at the sn‐1 and 2 position of TGs in LDM were significantly higher than in RM and HM groups. Polyunsaturated fatty acids (e.g.,18:2n‐6, 18:3n‐3, and 20:4n‐6) tended to occur at the sn‐1 position in TG, but at the sn‐2 position in PC and PE. Significantly differential lipids were mainly enriched in GP, GL, and SP pathways, all considered key pathways for regulating IMF. The results reveal the components, structures and metabolic pathways of lipid molecules in donkey meat, and provide novel insight into the development of donkey meat products and accurate regulation of IMF.
Practical Application
Intramuscular fat (IMF) is an important factor affecting meat quality, which is directly related to meat flavor, juiciness, and tenderness, but lipid and metabolic profiles of IMF remain unclear. The current results provide basic information for the development of donkey meat products, and broaden our understanding of the regulation of IMF.
The metallic green beetle, Anomala corpulenta (Coleoptera: Scarabaeidae: Rutelinae), is a destructive pest in agriculture and horticulture throughout Asia, including China. Olfaction plays a crucial ...role in the survival and reproduction of A. corpulenta. As a non-model species, A. corpulenta is poorly understood, and information regarding the molecular mechanisms underlying olfaction in A. corpulenta and other scarab species is scant.
We assembled separate antennal transcriptome for male and female A. corpulenta using Illumina sequencing technology. The relative abundance of transcripts with gene ontology annotations, including those related to olfaction in males and females was highly similar. Transcripts encoding 15 putative odorant binding proteins, five chemosensory proteins, one sensory neuron membrane protein, 43 odorant receptors, eight gustatory receptors, and five ionotropic receptors were identified. The sequences of all of these chemosensory-related transcripts were confirmed using reverse transcription polymerase chain reaction (RT-PCR), and direct DNA sequencing. The expression patterns of 54 putative chemosensory genes were analyzed using quantitative real time RT-PCR (qRT-PCR). Antenna-specific expression was detected for many of these genes, suggesting that they may have important functions in semiochemical detection.
The identification of a large number of chemosensory proteins provides a major resource for the study of the molecular mechanism of odorant detection in A. corpulenta and its chemical ecology. The genes identified, especially those that were expressed at high levels in the antennae may represent novel molecular targets for the development of population control strategies based on the manipulation of chemoreception-driven behaviors.
The hydrogen storage of (TiZr0.1)xCr1.7-yFeyMn0.3 (1.05 <x < 1.2, 0.2 <y < 0.6) alloys, prepared by Ar plasma arc melting, were investigated by X-ray diffraction, pressure-composition- temperature ...(PCT). The results indicated that all (TiZr0.1)xCr1.7-yFeyMn0.3 (1.05 ≤x ≤ 1.2, 0.2 ≤y ≤ 0.6) alloys were determined as C14-type Laves phase, the cell parameters a, c and unit cell volume of (TiZr0.1)xCr1.1Fe0.6Mn0.3 (1.05 ≤x ≤ 1.2) alloys increased with increasing the (TiZr) super-stoichiometry from 1.05 to 1.2, and the value of a/c almost unchanged. The hydrogen absorption and desorption plateau pressure decreased from 5.6, 4.4–2.6, 2.2 MPa with the increase of (TiZr) super-stoichiometry from 1.05 to1.2 at 274 K respectively, and the hydrogen desorption plateau pressure decline was not obvious when the (TiZr) super-stoichiometry exceeded 1.15. The (TiZr0.1)1.1Cr1.1Fe0.6Mn0.3 alloy had the best comprehensive properties about the maximum and reversible hydrogen storage capacity was 1.79 and 1.45 wt% respectively. The cell parameters a, c and unit cell volume of (TiZr0.1)1.1Cr1.7-yFeyMn0.3(0.2 ≤y ≤ 0.6) alloys increased as the ratio of Fe/Cr content decreased. The hydrogenation and dehydrogenation plateau pressure decreased from 4.5, 3.4–1.0, 0.9 MPa respectively and the maximum hydrogen storage capacity increased from 1.79 to 2.0 wt% as the Fe content reduced from 0.6 to 0.2 at 274 K. The maximum and the reversible hydrogen storage capacity were about 2.0 and 1.65 wt% as the ratio of Fe/Cr was 0.13 (ie, (TiZr0.1)1.1Cr1.5Fe0.2Mn0.3 alloy), its relative molar enthalpy of dissociation hydrogen was 24.30 kJ/mol H2.
An efficient and robust in situ surface-confined strategy was demonstrated for the fabrication of single-atom Fe-N4 on N-doped carbon nanoleaves (L-FeNC). Benefiting from abundant Fe-N4 active sites, ...enhanced mass and charge transfer, L-FeNC delivered superior performance for ORR and Zn-air battery to commercial Pt/C.
Display omitted
•In situ surface-confined strategy was demonstrated to fabricate L-FeNC.•L-FeNC showed an E1/2 of 0.89 V and good stability for ORR in 0.1 M KOH.•High ORR performance is owing to abundant Fe-N4, favored mass and charge transfer.
Controllable fabrication of Fe-N-C based single-atom catalysts (SACs) for enhanced electrocatalytic performance is highly desirable but still challenging. Here, an in situ surface-confined strategy was demonstrated for the synthesis of single atomic Fe-N4 on N-doped carbon nanoleaves (L-FeNC). The in situ generated Zn3Fe(CN)62 could not only serve as a protection layer against collapse of nanoleaves but also provide abundant Fe source for the formation of Fe-N moieties during pyrolysis, leading to high surface area and high graphitization degree of L-FeNC simultaneously. Benefiting from abundant Fe-N4 active sites, enhanced mass and charge transfer, the as-prepared L-FeNC manifested a half-wave potential of 0.89 V for oxygen reduction reaction (ORR) in 0.1 M KOH. A maximum power density of 140 mW cm−2 and stable discharge voltage even after operation for 50,000 s have been demonstrated when the L-FeNC was used as air cathode for Zn-air battery. This work not only provided a unique surface-confined strategy for the synthesis of two-dimensional nanocarbons, but also demonstrated the significant benefit from rational design and engineering of Fe-N-C SACs, thus offering great opportunities for fabrication of efficient energy conversion and storage devices.
β-Cell dysfunction and β-cell loss are hallmarks of type 2 diabetes (T2D). Here, we found that trimethylamine N-oxide (TMAO) at a similar concentration to that found in diabetes could directly ...decrease glucose-stimulated insulin secretion (GSIS) in MIN6 cells and primary islets from mice or humans. Elevation of TMAO levels impairs GSIS, β-cell proportion, and glucose tolerance in male C57BL/6 J mice. TMAO inhibits calcium transients through NLRP3 inflammasome-related cytokines and induced Serca2 loss, and a Serca2 agonist reversed the effect of TMAO on β-cell function in vitro and in vivo. Additionally, long-term TMAO exposure promotes β-cell ER stress, dedifferentiation, and apoptosis and inhibits β-cell transcriptional identity. Inhibition of TMAO production improves β-cell GSIS, β-cell proportion, and glucose tolerance in both male db/db and choline diet-fed mice. These observations identify a role for TMAO in β-cell dysfunction and maintenance, and inhibition of TMAO could be an approach for the treatment of T2D.
PDF
