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1.
Cell ; 180(5): 862-877.e22, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32142679

RESUMO

Using untargeted metabolomics (n = 1,162 subjects), the plasma metabolite (m/z = 265.1188) phenylacetylglutamine (PAGln) was discovered and then shown in an independent cohort (n = 4,000 subjects) to be associated with cardiovascular disease (CVD) and incident major adverse cardiovascular events (myocardial infarction, stroke, or death). A gut microbiota-derived metabolite, PAGln, was shown to enhance platelet activation-related phenotypes and thrombosis potential in whole blood, isolated platelets, and animal models of arterial injury. Functional and genetic engineering studies with human commensals, coupled with microbial colonization of germ-free mice, showed the microbial porA gene facilitates dietary phenylalanine conversion into phenylacetic acid, with subsequent host generation of PAGln and phenylacetylglycine (PAGly) fostering platelet responsiveness and thrombosis potential. Both gain- and loss-of-function studies employing genetic and pharmacological tools reveal PAGln mediates cellular events through G-protein coupled receptors, including α2A, α2B, and ß2-adrenergic receptors. PAGln thus represents a new CVD-promoting gut microbiota-dependent metabolite that signals via adrenergic receptors.

2.
Adv Mater ; : e2000287, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32134521

RESUMO

Zinc-iodine aqueous batteries (ZIABs) are highly attractive for grid-scale energy storage due to their high theoretical capacities, environmental friendliness, and intrinsic non-flammability. However, because of the close redox potential of Zn stripping/platting and hydrogen evolution, slight overcharge of ZIABs would induce drastic side reactions, serious safety concerns, and battery failure. A novel type of stimulus-responsive zinc-iodine aqueous battery (SR-ZIAB) with fast overcharge self-protection ability is demonstrated by employing a smart pH-responsive electrolyte. Operando spectroelectrochemical characterizations reveal that the battery failure mechanism of ZIABs during overcharge arises from the increase of electrolyte pH induced by hydrogen evolution as well as the consequent irreversible formation of insulating ZnO at anode and soluble Zn(IO3 )2 at cathode. Under overcharge conditions, the designed SR-ZIABs can be rapidly switched off with capacity degrading to 6% of the initial capacity, thereby avoiding continuous battery damage. Importantly, SR-ZIABs can be switched on with nearly 100% of capacity recovery by re-adjusting the electrolyte pH. This work will inspire the development of aqueous Zn batteries with smart self-protection ability in the overcharge state.

3.
Nanoscale ; 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32100815

RESUMO

Given the high cost and poisoning issues of Pt, developing Pd-based catalysts as substitutes is highly essential. Although substantial progress has been made, the synthesis of Pd-based electrocatalysts with both high activity and stability in the oxygen reduction reaction (ORR) remains a challenge. In this work, we prepared Pd-Ag nanowires with up to micro-sized length and a diameter of ∼17 nm via a facile modified polyol method. The obtained Pd-Ag nanowires (NWs) exhibit interlaced features and are rich in grain boundary defects. Due to the continuous grain boundaries in the one-dimensional (1D) structure and the optimized composition, the synthesized Pd1Ag1 NWs show half-wave potential of 0.897 V and mass activity of 0.103 A mg-1 in alkaline media toward ORR, higher than those of both state-of-the-art Pt/C and other Pd-Ag counterparts. Significantly, after stability tests over 5000 cycles, Pd1Ag1 NWs shows a 2 mV positive shift, much better than that of Pt/C, exhibiting striking stability for ORR. This work may provide an avenue to construct advanced catalysts by surface defect engineering.

4.
PLoS One ; 15(1): e0228276, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999793

RESUMO

Evaluation of fish nutritional content information could provide essential guidance for seafood consumption and human health protection. This study investigated the lipid contents, fatty acid compositions, and nutritional qualities of 22 commercially important marine fish species from the Pearl River Estuary (PRE), South China Sea. All the analyzed species had a low to moderate lipid content (0.51-7.35% fat), with no significant differences in fatty acid profiles among fishes from different lipid categories (p > 0.05). Compared with previous studies from other regions, the examined fish species exhibited higher proportions of saturated fatty acids (SFAs, 39.1 ± 4.00%) and lower contents of polyunsaturated fatty acids (PUFAs, 21.6 ± 5.44%), presumably due to the shifted diet influence from increased diatoms and decreased dinoflagellate over the past decades in the PRE. This study further revealed that there was a significantly negative correlation between the trophic levels and levels of PUFAs in the examined species (Pearson's r = -0.42, p = 0.04), likely associated with their differed dietary composition. Considering the health benefit of PUFAs, a few marine fish in PRE with low levels of PUFAs might have no significant contribution to the cardiovascular disease prevention, although fish with different fatty acid profiles most likely contribute differently towards human health. Additional studies are needed in order to comprehensively analyze the nutritional status of fish species in the PRE.


Assuntos
Ácidos Graxos/análise , Peixes , Alimentos Marinhos/análise , Animais , China , Estuários , Rios
5.
Integr Environ Assess Manag ; 16(3): 392-399, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31944533

RESUMO

Adsorption of polycyclic aromatic hydrocarbons (PAHs) on root surfaces has essential impacts on PAH phytoremediation. An Fe plaque is commonly formed on the root surface of aquatic plants. Therefore, it is worth investigating the impact of the Fe plaque on PAH adsorption on rice root surfaces. Using Bayesian linear water-methanol cosolvent models, we estimated accurate water-biosorbent partition coefficient values for phenanthrene, pyrene, and benzo[a]pyrene between water and rice root biosorbent fractions, including rice root materials with Fe plaque, removed Fe plaque, and removed Fe plaque and lipids. Our results showed that Fe plaque inhibited the adsorption of PAHs on rice root surface; the inhibition impacts increased with hydrophobicity of PAHs. This result highlights the need for considering the impact of Fe plaque on PAH adsorption during phytoremediation. Integr Environ Assess Manag 2020;16:392-399. © 2020 SETAC.

6.
Chem Commun (Camb) ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31967115

RESUMO

A high-voltage aqueous zinc-manganese battery using an alkaline-mild hybrid electrolyte is reported. The operation voltage of the battery can reach 2.2 V. The energy density is 487 W h kg-1 at 200 mA g-1, calculated based on the positive electrode material, higher than that of a Zn-MnO2 battery in mild electrolyte and those of other Zn-based aqueous batteries.

7.
J Ultrasound Med ; 39(1): 139-145, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31267549

RESUMO

OBJECTIVES: The peak systolic velocity (PSV) and end-diastolic velocity (EDV) obtained by carotid duplex ultrasound (CDU) imaging of the internal carotid arteries (ICAs) are parameters used to determine the severity of ICA stenosis. Severe aortic stenosis (AS) results in a parvus-et-tardus pattern on spectral Doppler waveforms; however, the impact of severe AS on CDU velocities is unclear. The purpose of this study was to assess the impact of severe AS on CDU velocities by evaluating changes in CDU velocities before and after aortic valve replacement (AVR) METHODS: A single-center retrospective review of patients with severe AS who underwent surgical AVR and who had preoperative and postoperative CDU examinations performed within 12 months of each other was conducted. Patients with any carotid intervention between the preoperative and postoperative CDU were excluded. RESULTS: We identified 92 patients who satisfied all inclusion criteria. The mean age was 72.2 years; 71.7% were men; the mean preoperative aortic valve area ± SD was 0.8 ± 0.2 cm2 ; and the mean time from preoperative to postoperative AVR CDU was 182.3 ± 98.4 days. The peak aortic valve gradient decreased from 62.5 to 22.0 mm Hg after AVR (P < .001); however, there were no significant changes in the PSV or EDV in either the right or left ICA. CONCLUSIONS: Although severe AS may cause characteristic changes in the spectral Doppler waveform on CDU imaging, there is no significant effect on the ICA PSV or EDV. Adjustments in velocity criteria to determine the degree of carotid artery stenosis in patients with substantial AS may not be necessary.

8.
J Integr Plant Biol ; 62(2): 165-180, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30697931

RESUMO

Targeting-induced local lesions in genomes (TILLING) is a powerful reverse-genetics tool that enables high-throughput screening of genomic variations in plants. Although TILLING has been developed for many diploid plants, the technology has been used in very few polyploid species due to their genomic complexity. Here, we established an efficient capillary electrophoresis-based TILLING platform for allotetraploid cultivated tobacco (Nicotiana tabacum L.) using an ethyl methanesulfonate (EMS)-mutagenized population of 1,536 individuals. We optimized the procedures for endonuclease preparation, leaf tissue sampling, DNA extraction, normalization, pooling, PCR amplification, heteroduplex formation, and capillary electrophoresis. In a test screen using seven target genes with eight PCR fragments, we obtained 118 mutants. The mutation density was estimated to be approximately one mutation per 106 kb on average. Phenotypic analyses showed that mutations in two heavy metal transporter genes, HMA2S and HMA4T, led to reduced accumulation of cadmium and zinc, which was confirmed independently using CRISPR/Cas9 to generate knockout mutants. Our results demonstrate that this powerful TILLING platform (available at http://www.croptilling.org) can be used in tobacco to facilitate functional genomics applications.

9.
Adv Mater ; 32(4): e1905361, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31815328

RESUMO

Rechargeable sodium-iodine (Na-I2 ) batteries are attracting growing attention for grid-scale energy storage due to their abundant resources, low cost, environmental friendliness, high theoretical capacity (211 mAh g-1 ), and excellent electrochemical reversibility. Nevertheless, the practical application of Na-I2 batteries is severely hindered by their poor cycle stability owing to the serious dissolution of polyiodide in the electrolyte during charge/discharge processes. Herein, the atomic modulation of metal-bis(dihydroxy) species in a fully conjugated phthalocyanine copper metal-organic framework (MOF) for suppression of polyiodide dissolution toward long-time cycling Na-I2 batteries is demonstrated. The Fe2 [(2,3,9,10,16,17,23,24-octahydroxy phthalocyaninato)Cu] MOF composited with I2 (Fe2 -O8 -PcCu/I2 ) serves as a cathode for a Na-I2 battery exhibiting a stable specific capacity of 150 mAh g-1 after 3200 cycles and outperforming the state-of-the-art cathodes for Na-I2 batteries. Operando spectroelectrochemical and electrochemical kinetics analyses together with density functional theory calculations reveal that the square planar iron-bis(dihydroxy) (Fe-O4 ) species in Fe2 -O8 -PcCu are responsible for the binding of polyiodide to restrain its dissolution into electrolyte. Besides the monovalent Na-I2 batteries in organic electrolytes, the Fe2 -O8 -PcCu/I2 cathode also operates stably in other metal-I2 batteries like aqueous multivalent Zn-I2 batteries. Thus, this work offers a new strategy for designing stable cathode materials toward high-performance metal-iodine batteries.

10.
Chemosphere ; 240: 124844, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550584

RESUMO

Cetaceans and humans shared the same route of exposure to many anthropogenic contaminants via fish consumption. To assess the health risks associated with heavy metal levels in fishes from the Pearl River Estuary (PRE) and the seasonal dynamics, 13 fish species (n = 675) consumed by the Indo-Pacific humpback dolphins (Sousa chinensis) and humans were analyzed for concentrations of nine heavy metals. Heavy metal levels vary significantly by species and by season in the PRE fishes. The two eel goby species were the most contaminated fish species, which had the highest levels of Cu, Pb, Hg, Mn and Se. Levels of non-essential metals (As and Pb) in many different fish species were all found significantly higher in dry season than in wet season, which may reflect the dilution effect on contaminant levels in the PRE waters in rainy season. For essential metals, Cu, Cr and Se in many fish species were significantly higher in dry season compared to wet season, while Se and Mn in the other fish species showed an opposite pattern, since essential metal accumulation could be influenced by several physiological processes in life. Risk assessment for dolphins showed that inorganic-As levels in all fishes exceeded the safe limits, whereas a more conservative approach indicated that the levels of all metals in all fish samples had toxic effects on dolphins, except for Hg. Human health risk analysis showed that inorganic-As levels in tonguesole (all year) and sillago (dry season) and Cr levels in pomfret (dry season) exceeded the acceptable values.


Assuntos
Metais Pesados/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Animais , China , Golfinhos , Estuários , Peixes , Humanos , Rios
11.
ACS Appl Mater Interfaces ; 12(4): 4366-4372, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31867946

RESUMO

A hybrid Li-air battery uses a protected lithium anode and a porous air cathode in an aqueous electrolyte, based on a 4-e oxygen reduction reaction/oxygen evolution reaction (ORR/OER). It avoids the insoluble and insulating Li2O2 product in a typical nonaqueous Li-air battery, and it owns unique advantages. A bifunctional cathode catalyst is crucial to battery performance. Here, we synthesize an ultrathin N-doped graphene-encapsulated nanosphere Co-Ni alloy (Co-Ni@NG). It has hierarchical architecture consisting of a uniform Co-Ni nanoalloy coated with a thin layer of N-doped graphene, showing high activity, high stability, and lower overpotential between the ORR and OER (0.55 V between onset potentials). It exhibited a discharge/charge voltage gap of 0.55 V at a current density of 1.4 mA cm-2, which is much smaller than the commercial Pt/C catalyst. It delivered an energy density of 3158 Wh kg-1 and a power density as high as 134.2 W m-2 at a current density of 7 mA cm-2. The graphene shells protect the alloy catalyst and improve the durability of the catalyst. One hundred cycles were demonstrated without significant deterioration. It was testified as a promising energy storage system with high energy density, efficiency, reliability, and durability.

12.
Theriogenology ; 142: 390-399, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31708193

RESUMO

Cryopreservation of marine fish embryos causes to severe cryogenic damage, and to date, adults have not been reared from embryos that were cryopreserved. Here, we optimized vitrification factors to improve the survival and hatching rate of kelp grouper (Epinephelus moara) embryos after cryopreservation. We screened the effects of 11 vitrification solution concentrations (25-50%) on the survival rate of embryos at four developmental stages (16S, 18S, 22S, TB). We investigated the effects of different equilibration time (25-45min) on the survival rate and the influence of vitrification solutions on embryonic volume. In addition, we tested the effects of treating embryos at five different developmental stages (4-6S, 16S, 22S, TB, HB) with different vitrification solutions (35% PMG3S and 35% PMG3T), prechilling temperature (-5 °C and 4 °C) and prechilling time. In total, 9855 embryos were cryopreserved at 10 developmental stages, from optic capsule stage to pre-hatch stage. We found that kelp grouper embryos performed best at equilibration time of 30 min. Embryos at the tail-bud stage exhibited greater tolerance to vitrification than other stages. Vitrification solutions that contained sucrose showed better survival rates compared to embryos treated with vitrification solutions containing trehalose. Pre-chilling treatment improved viability before freezing, but did not improve viability after freezing. In the most optimal condition we identified in this study, the average survival, normal development and malformation rates of cryopreserved embryos were 6.32%, 2.36% and 3.49%, and 39.85% of the surviving embryos that were cryopreserved hatched. The hatched larvae gradually died at day 12 of cultivation, where the longest surviving individuals lived for 16 days. This study provides valuable data for improving survival and hatching rate of cryopreserved grouper embryos, and provides references for further exploring techniques in fish embryo cryopreservation.

13.
Zhongguo Gu Shang ; 32(11): 1053-1057, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31870056

RESUMO

OBJECTIVE: To explore clinical effect of infrared thermal imaging technology for the treatment of free anterolateral thigh perforator flap transplantation. METHODS: From June 2014 to June 2018, 31 patients with skin defect at various degrees treated by free anterolateral thigh perforator flap transplantation, including 21 males and 10 females aged from 16 to 59 years old with an average age of(35.3±1.5) years old, the courses of disease ranged from 2 to 4 weeks with an average of (1.8±0.6) weeks. The number of perforating branch, the position of the perforating branch, the perforating branch vitality detected by Doppler blood stream detector and parameters of thermal imaging image in order to guide design of skin flap, and compared results with the data of perforator arteries observed during the operation. RESULTS: Totally 52 branches of perforating arteries were detected by Doppler blood stream detector during operation, and 38 perforator branches were confirmed in operation, the accuracy rate was 73.1%. Thirty-eight branches of perforating arteries were detected by infrared thermography during operation, and 35 branches of perforating branches were confirmed in operation, the accuracy rate was 92.1%; there were statistical difference. The most dynamic perforating pivot found by Doppler blood stream detector was confirmed by intraoperative diagnosis, with an accuracy rate of 80.6%. The most dynamic perforating pivot found by infrared thermography is confirmed by intraoperative diagnosis, with an accuracy rate of 100%; there were statistical difference. Thirty-one flaps were survived without vascular crisis occurred. All patients were followed up from 6 to 18 months with an average of(10.7±1.2) months. The flaps survived with soft texture and good blood circulation, the defect was not bloated, the color of skin flap was basically the same as that of the normal skin, and the limbs appearance and function recovered well. CONCLUSIONS: Infrared infrared thermal imaging technology could be used as a new technology in localization of perforator artery in free anterolateral thigh perforator flap transplantation.


Assuntos
Retalho Perfurante , Procedimentos Cirúrgicos Reconstrutivos , Lesões dos Tecidos Moles , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante de Pele , Coxa da Perna , Adulto Jovem
14.
Dalton Trans ; 48(47): 17683-17690, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31764933

RESUMO

Silicon/carbon (Si/C) nanocomposite anodes have attracted great interest for their use in lithium-ion batteries (LIBs). However, Si nanoparticles are difficult to stabilize on a carbon surface. Herein, we solve this stabilization problem by designing a Si/silicon carbide/nanographite sheet (Si/SiC/NanoG) nanocomposite. The Si/SiC/NanoG nanocomposite is synthesized by the magnesium thermal reduction of a mixture of silica (SiO2) nanoparticles and NanoG at low temperature, which results in a sandwich-like structure in which the middle SiC layer serves as a linker to stabilize the Si nanoparticles on the surface of NanoGs. Electrochemical characterization shows that the Si/SiC/NanoG nanocomposite anode exhibits outstanding electrochemical performance (an initial reversible capacity of 1135.4 mA h g-1 and 80.4% capacity retention after 100 cycles at 100 mA g-1). This high capacity retention is due to the strong connection between Si and NanoG through the interfacial SiC layer, which buffers the volume changes during the Li-Si alloying-dealloying process. This research will contribute to the design of advanced Si/C anode materials of LIBs.

15.
Nanomaterials (Basel) ; 9(11)2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31731756

RESUMO

Silicon/carbon nanotube (Si/CNTs) nanocomposite is a promising anode material for lithium ion batteries (LIBs). Challenges related to the tricky synthesis process, as well as the weak interaction between Si and CNTs, hinder practical applications. To address these issues, a facile, one-step method to synthesize Si/CNTs nanocomposite by using silica (SiO2) as a reactant via a magnesium reduction process was developed. In this synthesis, the heat released enables the as-obtained Si to react with CNTs in the interfacial region to form silicon carbide (SiC). By virtue of the unique structure composed of Si nanoparticles strongly anchored to conductive CNTs network with stable Si-C chemical bonding, the Si/SiC/CNT nanocomposite delivers a stable capacity of ~1100 mAh g-1 and a capacity retention of about 83.8% after 200 cycles at a current density of 100 mA g-1. Our studies may provide a convenient strategy for the preparation of the Si/C anode of LIBs.

18.
Small ; : e1903854, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31532893

RESUMO

Over the past few years, great attention has been given to nonaqueous lithium-air batteries owing to their ultrahigh theoretical energy density when compared with other energy storage systems. Most of the research interest, however, is dedicated to batteries operating in pure or dry oxygen atmospheres, while Li-air batteries that operate in ambient air still face big challenges. The biggest challenges are H2 O and CO2 that exist in ambient air, which can not only form byproducts with discharge products (Li2 O2 ), but also react with the electrolyte and the Li anode. To this end, recent progress in understanding the chemical and electrochemical reactions of Li-air batteries in ambient air is critical for the development and application of true Li-air batteries. Oxygen-selective membranes, multifunctional catalysts, and electrolyte alternatives for ambient air operational Li-air batteries are presented and discussed comprehensively. In addition, separator modification and Li anode protection are covered. Furthermore, the challenges and directions for the future development of Li-air batteries are presented.

19.
iScience ; 19: 316-325, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31404832

RESUMO

Lithium-sulfur (Li-S) batteries with high theoretical energy density attract great research attention. Although tremendous efforts have been made, heat tolerance capability of Li-S batteries is a topic rarely touched, although it is essential for practical application. At high temperatures, the dissolution of the polysulfides is aggravated, and the safety issue becomes severe. Herein, by using sulfur/polyacrylonitrile (SPAN) composites as positive electrode materials and a gel polymer membrane with carbonate electrolyte, we successfully realized a Li-S battery with remarkable heat-resistant performance at 50°C and 60°C. The SPAN-positive materials allow the Li-S battery operated in safer carbonate-containing electrolyte. The gel polymer electrolyte enhances the charge transfer, maintains the morphology of Li metal during cycling, and suppresses the migration of the soluble polysulfides, which is also observed when SPAN is used as positive electrode material. This contribution would bring new opportunity to extend the application of lithium batteries at high temperatures.

20.
Biosens Bioelectron ; 142: 111594, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31430612

RESUMO

We report a novel anode electrocatalyst, iron carbide nanoparticles dispersed in porous graphitized carbon (Nano-Fe3C@PGC), which is synthesized by facile approach involving a direct pyrolysis of ferrous gluconate and a following removal of free iron, but provides microbial fuel cells with superior performances. The physical characterizations confirm the unique configuration of iron carbide nanoparticles with porous graphitized carbon. Electrochemical measurements demonstrate that the as-synthesized Nano-Fe3C@PGC exhibits an outstanding electrocatalytic activity toward the charge transfer between bacteria and anode. Equipped with Nano-Fe3C@PGC, the microbial fuel cells based on a mixed bacterium culture yields a power density of 1856 mW m-2. The resulting excellent performance is attributed to the large electrochemical active area and the high electronic conductivity that porous graphitized carbon provides and the enriched electrochemically active microorganisms and enhanced activity towards the redox reactions in microorganisms by Fe3C nanoparticles.


Assuntos
Fontes de Energia Bioelétrica , Compostos Inorgânicos de Carbono/química , Grafite/química , Compostos de Ferro/química , Nanoestruturas/química , Fontes de Energia Bioelétrica/economia , Fontes de Energia Bioelétrica/microbiologia , Compostos Inorgânicos de Carbono/economia , Catálise , Condutividade Elétrica , Eletrodos , Desenho de Equipamento , Grafite/economia , Compostos de Ferro/economia , Nanopartículas/química , Nanopartículas/economia , Nanopartículas/ultraestrutura , Nanoestruturas/economia , Nanoestruturas/ultraestrutura , Porosidade
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