14 research outputs found
Ultrafine NiāPt Alloy Nanoparticles Grown on Graphene as Highly Efficient Catalyst for Complete Hydrogen Generation from Hydrazine Borane
Ultrafine NiāPt alloy NPs
grown on graphene (NiPt/graphene)
have been facilely prepared via a simple one-step coreduction synthetic
route and characterized by transmission electron microscopy, energy-dispresive
X-ray spectroscopy, X-ray diffraction, inductively coupled plasma
atomic emission spectroscopy, X-ray photoelectron spectroscopy, Raman
and Fourier transform infrared methods. The characterized results
showed that ultrafine NiāPt NPs with a small size of around
2.3 nm were monodispersed on the graphene nanosheet. Compared to the
pure Ni<sub>0.9</sub>Pt<sub>0.1</sub> alloy NPs, graphene supported
Ni<sub>0.9</sub>Pt<sub>0.1</sub> alloy NPs exhibited much higher activity
and hydrogen selectivity (100%) toward conversion of hydrazine borane
(HB) to hydrogen. It is first found that the durability of the catalyst
can be greatly enhanced by the addition of an excess amount of NaOH
in this reaction, because of the neutralization of NaOH by the byproduct
H<sub>3</sub>BO<sub>3</sub> produced from the hydrolysis of HB. After
six cycles of the catalytic reaction, no appreciable decrease in activity
was observed, indicating that the Ni<sub>0.9</sub>Pt<sub>0.1</sub>/graphene catalysts have good durability/stability
Controlled Synthesis of MOF-Encapsulated NiPt Nanoparticles toward Efficient and Complete Hydrogen Evolution from Hydrazine Borane and Hydrazine
The catalytic dehydrogenation of
hydrazine borane (N<sub>2</sub>H<sub>4</sub>BH<sub>3</sub>) and hydrous
hydrazine (N<sub>2</sub>H<sub>4</sub>Ā·H<sub>2</sub>O) for H<sub>2</sub> evolution is
considered as two of the pivotal reactions for the implementation
of the hydrogen-based economy. A reduction rate controlled strategy
is successfully applied for the encapsulating of uniform tiny NiPt
alloy nanoclusters within the opening porous channels of MOFs in this
work. The resultant Ni<sub>0.9</sub>Pt<sub>0.1</sub>/MOF coreāshell
composite with a low Pt content exerted exceedingly high activity
and durability for complete H<sub>2</sub> evolution (100% hydrogen
selectivity) from alkaline N<sub>2</sub>H<sub>4</sub>BH<sub>3</sub> and N<sub>2</sub>H<sub>4</sub>Ā·H<sub>2</sub>O solution. The
features of small NiPt alloy NPs, strong synergistic effect between
NiPt alloy NPs and the MOF, and open pore structure for freely mass
transfer made NiPt/MIL-101 an excellent catalyst for highly efficient
H<sub>2</sub> evolution from N<sub>2</sub>H<sub>4</sub>BH<sub>3</sub> or N<sub>2</sub>H<sub>4</sub>Ā·H<sub>2</sub>O
A 2D Ba<sub>2</sub>N Electride for Transition Metal-Free N<sub>2</sub> Dissociation under Mild Conditions
N2 activation is a key step in the industrial
synthesis
of ammonia and other high-value-added N-containing chemicals, and
typically is heavily reliant on transition metal (TM) sites as active
centers to reduce the large activation energy barrier for N2 dissociation. In the present work, we report that a 2D electride
of Ba2N with anionic electrons in the interlayer spacings
works efficiently for TM-free N2 dissociation under mild
conditions. The interlayer electrons significantly boost N2 dissociation with a very small activation energy of 35 kJ molā1, as confirmed by the N2 isotopic exchange
reaction. The reaction of anionic electrons with N2 molecules
stabilizes (N2)2ā anions, the so-called
diazenide, in the large interlayer space (ā¼4.5 Ć
) sandwiched
by 2 cationic slabs of Ba2N as the main intermediate
Table_2_Response of Gut Microbiota to Metabolite Changes Induced by Endurance Exercise.XLSX
<p>A few animal studies have shown that wheel running could reverse an unhealthy status by shifting the gut microbial composition, but no investigations have studied the effect of endurance running, such as marathon running, on human gut microbial communities. Since many findings have shown that marathon running immediately causes metabolic changes in blood, urine, muscles and lymph that potentially impact the gut microbiota (GM) within several hours. Here, we investigated whether the GM immediately responds to the enteric changes in amateur half-marathon runners. Alterations in the metabolic profile and microbiota were investigated in fecal samples based on an untargeted metabolomics methodology and 16S rDNA sequencing analysis. A total of 40 fecal metabolites were found significantly changed after finishing a half-marathon race. The most significantly different metabolites were organic acids (the major increased metabolites) and nucleic acid components (the major decreased metabolites). The enteric changes induced by running did not affect the Ī±-diversity of the GM, but the abundances of certain microbiota members were shown to be significantly different before and after running. The family Coriobacteriaceae was identified as a potential biomarker that links exercise with health improvement. Functional prediction showed a significantly activated āCell motilityā function of GM within participants after running. Correlation analysis indicated that the observed differential GM in our study might have been the shared outcome of running and diet. This study provided knowledge regarding the health impacts of marathon running from the perspective of GM for the first time. Our data indicated that long-distance endurance running can immediately cause striking metabolic changes in the gut environment. Gut microbes can rapidly respond to the altered fecal metabolites by adjusting certain bacterial taxa. These findings highlighted the health-promoting benefits of exercise from the perspective of GM.</p
Image_1_Response of Gut Microbiota to Metabolite Changes Induced by Endurance Exercise.TIF
<p>A few animal studies have shown that wheel running could reverse an unhealthy status by shifting the gut microbial composition, but no investigations have studied the effect of endurance running, such as marathon running, on human gut microbial communities. Since many findings have shown that marathon running immediately causes metabolic changes in blood, urine, muscles and lymph that potentially impact the gut microbiota (GM) within several hours. Here, we investigated whether the GM immediately responds to the enteric changes in amateur half-marathon runners. Alterations in the metabolic profile and microbiota were investigated in fecal samples based on an untargeted metabolomics methodology and 16S rDNA sequencing analysis. A total of 40 fecal metabolites were found significantly changed after finishing a half-marathon race. The most significantly different metabolites were organic acids (the major increased metabolites) and nucleic acid components (the major decreased metabolites). The enteric changes induced by running did not affect the Ī±-diversity of the GM, but the abundances of certain microbiota members were shown to be significantly different before and after running. The family Coriobacteriaceae was identified as a potential biomarker that links exercise with health improvement. Functional prediction showed a significantly activated āCell motilityā function of GM within participants after running. Correlation analysis indicated that the observed differential GM in our study might have been the shared outcome of running and diet. This study provided knowledge regarding the health impacts of marathon running from the perspective of GM for the first time. Our data indicated that long-distance endurance running can immediately cause striking metabolic changes in the gut environment. Gut microbes can rapidly respond to the altered fecal metabolites by adjusting certain bacterial taxa. These findings highlighted the health-promoting benefits of exercise from the perspective of GM.</p
Table_1_Response of Gut Microbiota to Metabolite Changes Induced by Endurance Exercise.XLSX
<p>A few animal studies have shown that wheel running could reverse an unhealthy status by shifting the gut microbial composition, but no investigations have studied the effect of endurance running, such as marathon running, on human gut microbial communities. Since many findings have shown that marathon running immediately causes metabolic changes in blood, urine, muscles and lymph that potentially impact the gut microbiota (GM) within several hours. Here, we investigated whether the GM immediately responds to the enteric changes in amateur half-marathon runners. Alterations in the metabolic profile and microbiota were investigated in fecal samples based on an untargeted metabolomics methodology and 16S rDNA sequencing analysis. A total of 40 fecal metabolites were found significantly changed after finishing a half-marathon race. The most significantly different metabolites were organic acids (the major increased metabolites) and nucleic acid components (the major decreased metabolites). The enteric changes induced by running did not affect the Ī±-diversity of the GM, but the abundances of certain microbiota members were shown to be significantly different before and after running. The family Coriobacteriaceae was identified as a potential biomarker that links exercise with health improvement. Functional prediction showed a significantly activated āCell motilityā function of GM within participants after running. Correlation analysis indicated that the observed differential GM in our study might have been the shared outcome of running and diet. This study provided knowledge regarding the health impacts of marathon running from the perspective of GM for the first time. Our data indicated that long-distance endurance running can immediately cause striking metabolic changes in the gut environment. Gut microbes can rapidly respond to the altered fecal metabolites by adjusting certain bacterial taxa. These findings highlighted the health-promoting benefits of exercise from the perspective of GM.</p
Multiplex one-step Real-time PCR by Taqman-MGB method for rapid detection of pan and H5 subtype avian influenza viruses
<div><p>Avian influenza virus (AIV) can infect a variety of avian species and mammals, leading to severe economic losses in poultry industry and posing a substantial threat to public health. Currently, traditional virus isolation and identification is inadequate for the early diagnosis because of its labor-intensive and time-consuming features. Real-time RT-PCR (RRT-PCR) is an ideal method for the detection of AIV since it is highly specific, sensitive and rapid. In addition, as the new quencher MGB is used in RRT-PCR, it only needs shorter probe and helps the binding of target gene and probe. In this study, a pan-AIV RRT-PCR for the detection of all AIVs and H5-AIV RRT-PCR for detection of H5 AIV based on NP gene of AIV and HA gene of H5 AIV were successfully established using Taqman-MGB method. We tested 14 AIV strains in total and the results showed that the pan-AIV RRT-PCR can detect AIV of various HA subtypes and the H5-AIV RRT-PCR can detect H5 AIV circulating in poultry in China in recent three years, including H5 viruses of clade 7.2, clade 2.3.4.4 and clade 2.3.2.1. Furthermore, the multiplex detection limit for pan-AIV and H5-AIV RRT-PCR was 5 copies per reaction. When this multiplex method was applied in the detection of experimental and live poultry market samples, the detection rates of pan-AIV and H5 AIV in RRT-PCR were both higher than the routine virus isolation method with embryonated chicken eggs. The multiplex RRT-PCR method established in our study showed high sensitivity, reproducibility and specificity, suggesting the promising application of our method for surveillance of both pan AIV and prevalent H5 AIV in live poultry markets and clinical samples.</p></div
AIV strains used in this study and the detection limit of RRT-PCR method.
<p>AIV strains used in this study and the detection limit of RRT-PCR method.</p
Detection of H5 AIV in swabs from infected SPF chickens with virus isolation and RRT-PCR.
<p>Oral-pharyngeal swabs and cloacal swabs of 10 SPF chickens were collected at 24 h, 36 h and 48 h. The infection dose of SPF chicken was 0.2mL 10<sup>3</sup> EID<sub>50</sub> of H5 AIV. At 24 h and 36 h, no H5 AIV was detected in oral-pharyngeal samples in traditional virus isolation method while the number of positive trachea swabs through RRT-PCR detection at 24 h and 36 h were 5 and 2 respectively. The number of positive samples in RRT-PCR matched that in virus isolation at 48 h.</p