Background: Gastroparesis is one of the complications of diabetes mellitus, and long-term gastroparesis seriously affects patients quality of life. Most of the patients can be relieved after lifestyle improvement and ...Background: Gastroparesis is one of the complications of diabetes mellitus, and long-term gastroparesis seriously affects patients quality of life. Most of the patients can be relieved after lifestyle improvement and medication, but refractory gastroparesis is difficult to relieve, and is still a challenge in clinical treatment. Aim: To report a case of a patient with diabetic nephropathy combined with refractory gastroparesis, and to analyse the mechanism, diagnosis, severity grading, treatment of refractory gastroparesis in conjunction with a review of the literature, and to investigate the causes of recurrent nausea and vomiting in diabetic nephropathy patients with refractory diabetic gastroparesis and the possible effective treatment options. Case Presentation: The patient was hospitalised for recurrent nausea and vomiting and diagnosed with diabetic nephropathy and gastroparesis. Symptoms recurred after medication and peritoneal dialysis, and the patients symptoms were relieved after multifaceted interventions. Conclusion: Diabetic nephropathy and refractory gastroparesis can both manifest as digestive tract symptoms, and in the face of this complex disease, it is necessary to analyse the various etiological factors and take comprehensive treatment measures.展开更多
Rational coupling of hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) catalysts is extremely important for practical overall water splitting,but it is still challenging to construct such bifunctiona...Rational coupling of hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) catalysts is extremely important for practical overall water splitting,but it is still challenging to construct such bifunctional heterostructures.Herein,we present a metal-organic framework(MOF)-etching strategy to design free-standing and hierarchical hollow CoS_(2)-MoS_(2) heteronanosheet arrays for both HER and OER.Resulting from the controllable etching of MOF by MoO_(4)^(2-) and in-situ sulfuration,the obtained CoS_(2)-MoS_(2) possesses abundant heterointerfaces with modulated local charge distribution,which promote water dissociation and rapid electrocatalytic kinetics.Moreover,the two-dimensional hollow array architecture can not only afford rich surface-active sites,but also facilitate the penetration of electrolytes and the release of evolved H_(2)/O_(2) bubbles.Consequently,the engineered CoS_(2)-MoS_(2) heterostructure exhibits small overpotentials of 82 mV for HER and 266 mV for OER at 10 mA cm^(-2).The corresponding alkaline electrolyzer affords a cell voltage of 1.56 V at 10 mA cm^(-2) to boost overall water splitting,along with robust durability over 24 h, even surpassing the benchmark electrode couple composed of IrO_(2) and Pt/C The present work may provide valuable insights for developing MOF-derived heterogeneous electrocatalysts with tailored interface/surface structure for widespread application in catalysis and other energyrelated areas.展开更多
Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but ...Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but water-isolating solid-electrolyte interphase(SEI)films have been developed,however,the required high-purity chemical materials are extremely expensive.In this work,phosphogypsum(PG),an industrial byproduct produced from the phosphoric acid industry,is employed as a multifunctional protective layer to navigate uniform zinc deposition.Theoretical and experimental results demonstrate that PG-derived CaSO_(4)2H_(2)O can act as an artificial SEI layer to provide fast channels for Zn^(2+)transport.Moreover,CaSO_(4)2H_(2)O could release calcium ions(Ca^(2+))due to its relatively high Kspvalue,which have a higher binding energy than that of Zn^(2+)on the Zn surface,thus preferentially adsorbing to the tips of the protuberances to force zinc ions to nucleate at inert region.As a result,the Zn@PG anode achieves a high Coulombic efficiency of 99.5%during 500 cycles and long-time stability over 1000 hours at 1 m A cm^(-2).Our findings will not only construct a low-cost artificial SEI film for practical metal batteries,but also achieve a high-value utilization of phosphogypsum waste.展开更多
Microplastics(MPs)degradation due to light radiation,weathering,water erosion and biodegradation might change MPs physical and chemical characteristics and thereby change MPs behaviors in natural environments.This stu...Microplastics(MPs)degradation due to light radiation,weathering,water erosion and biodegradation might change MPs physical and chemical characteristics and thereby change MPs behaviors in natural environments.This study conducted a comparison investigation on polyvinyl chloride(PVC),polyethylene(PE)and polyamide(PA)degradation in three different environmental conditions,namely simulated UV light,natural light and natural water body.The results showed that degradation of MPs in natural environments is more complex than the case in a controlled experimental condition(such as simulated UV light).In the conditions of natural light and natural water body,MPs are more easily covered by sediments/microorganisms.Particularly in the natural water body,biofilm development is an important factor for MPs degradation and this is dependent on where MPs are located.PVC in the water surface adsorbed more prokaryotes and eukaryotes than those in the water bottom while PE and PA showed the opposite.The research outcomes also show that a complex interaction between MPs and heavy metals in different environments.In simulated UV light,heavy metals tended to leach from MPs while in the natural light and natural water body,heavy metal concentrations of MPs had a higher variability caused by continuous leaching-adsorption behaviors.Those outcomes were expected to contribute to an in-depth understanding of MP degradations and their environmental behaviors.展开更多
In this paper, by using time-weighted global estimates and the Lagrangian approach, we first investigate the global existence and uniqueness of the solution for the 2D inhomogeneous incompressible asymmetric fluids wi...In this paper, by using time-weighted global estimates and the Lagrangian approach, we first investigate the global existence and uniqueness of the solution for the 2D inhomogeneous incompressible asymmetric fluids with the initial(angular) velocity being located in sub-critical Sobolev spaces H^(s)(R^(2))(0<s<1) and the initial density being bounded from above and below by some positive constants. The global unique solvability of the 2D incompressible inhomogeneous asymmetric fluids with the initial data in the critical Besov space(u_(0), w_(0))∈˙B^(0)_(2,1)(R^(2))andρ^(−1)−1∈˙B^(ε)_(2/ε),1(R^(2))is established. In particular, the uniqueness of the solution is also obtained without any more regularity assumptions on the initial density which is an improvement on the recent result of Abidi and Gui(2021) for the 2D inhomogeneous incompressible NavierStokes system.展开更多
Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to organisms.Additionally,compared to original NPs,photodegraded NPs would pose higher toxicity.This is because their relatively higher speci...Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to organisms.Additionally,compared to original NPs,photodegraded NPs would pose higher toxicity.This is because their relatively higher specific surface areas and the presence of additives which can more easily leach.How original NPs and aged NPs affect plant growth has not been widely investigated.This work chose polyvinyl chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by 10.6%–22.5%),stem length(decreased by 2.8%–8.1%),dry weight(decreased by 6.3%–7.1%)and fresh weight(decreased by 6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosynthesis and absorption of nutrients and hence the decrease in chlorophyll and soluble sugar contents.According to transcriptomic investigation results,the presence of aged PVC-NPs primarily influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway)and phenylpropanoid biosynthesis(downregulated metabolic pathway)of pea seedlings.These results provide an in-depth understanding of how NPs influence the growth of plants.展开更多
Polyethylene microplastics(PE-MPs)have toxicity to ecological environment,including animals and plants.This study investigated the toxicity of photodegraded PE-MPs on Brassica rapa,which is a typical model plant and o...Polyethylene microplastics(PE-MPs)have toxicity to ecological environment,including animals and plants.This study investigated the toxicity of photodegraded PE-MPs on Brassica rapa,which is a typical model plant and only have around a 30-day life cycle.It is noted that the presence of photodegraded PEMPs inhibited Brassica rapa growth since the stem length decreased by 11.94%-51.11%while the fresh weight and dry weight decreased by 18.56%e27.46%and 1.90%-6.91%respectively,compared to the blank group.PE-MPs receiving more light radiation became more hydrophobic.This inhibited PE-MPs entering the plant body along with the process of plant absorbing water.Furthermore,when PE-MPs were located in the lower soil layers,Brassica rapa reaching them needs a longer time,hence showing lower toxicity effect than the case of PE-MPs located in the upper soil layer.The research outcomes also indicated that malondialdehyde(MDA)contents in photodegraded PE-MPs exposure group increased by 1.37%-7.28%while the catalase activity(CAT)increased by 60.11%.This means that PE-MPs caused oxidative stress response in plants,inducing plants to resist external stress.Transcriptomic analysis results showed that Brassica rapa,which was affected by PE-MPs,significantly up-regulated genes related to the plant-pathogen interaction pathway while the ribosome pathway genes were significantly downregulated.This led to a decrease in growth rate and a decrease in the homeostatic level of the ribosomal subunit and hence resulting in abnormal leaf vein development.These conclusions indicated the toxic effect and damage mechanism of photodegraded PE-MPs on Brassica rapa.The novelty of this study was to use both univariate analysis and transcriptomic analysis to investigate how photodegraded PE-MPs exert toxicity on Brassica rapa.The results can provide a theoretical basis for revealing the influence of MPs on plant growth.展开更多
MgAPO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 ratio.The samples were characterized by XRD,SEM,solid state NMR,FT-IR and NH3-TPD.Using...MgAPO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 ratio.The samples were characterized by XRD,SEM,solid state NMR,FT-IR and NH3-TPD.Using MgAPO-5 as acidic supports,bifunctional Pt/MgAPO-5 catalysts were prepared for hydrogenation of nitrobenzene to p-aminophenol (PAP).The results showed that the MgO/Al2O3 ratios influenced the Mg content and the acidity of MgAPO-5 samples,thereby greatly affecting the catalytic performance of Pt/MgAPO-5 catalysts.The selectivity to PAP over Pt/MgAPO-5 was dependent on the amount of strong acid sites of MgAPO-5.When the MgO/Al2O3 molar ratio was 0.5,the synthesized MgAPO-5 sample exhibited the largest amount of strong acid and a highest PAP yield of 41.1% was achieved over Pt/MgAPO-5 catalyst.展开更多
In this study,a g-C_(3)N_(4)-Cu_(2)O-TiO_(2) photocatalyst with a novel three-dimensional ordered macroporous(3DOM)structure was successfully prepared using a sacrificial template strategy and a photodeposition method...In this study,a g-C_(3)N_(4)-Cu_(2)O-TiO_(2) photocatalyst with a novel three-dimensional ordered macroporous(3DOM)structure was successfully prepared using a sacrificial template strategy and a photodeposition method.The influence of the special porous structure with cross pore channels on the photocatalytic properties of the as-prepared sample was studied in detail.Compared with the original photocatalyst(TiO_(2) with 3 wt%Pt),g-C_(3)N_(4)-Cu_(2)O-TiO_(2) exhibited a higher specific surface area and more active sites,thus accelerating the separation efficiency of the photogenerated electron-hole pair.Consequently,the as-prepared photocatalyst showed good photocatalytic performance,reaching a maximum hydrogen production rate of 12,108μmol g^(-1) h^(-1) and approximately five times higher than that of the pristine comparison sample.The enhanced photoactivity of the g-C_(3)N_(4)-Cu_(2)O-TiO_(2) heterojunction can be ascribed to its double p-n heterojunction and robust porous structure,where the photodeposited Cu_(2)O plays a synergistic catalytic role in the photocatalytic process and the outer clad g-C_(3)N_(4) layer prevents Cu_(2)O oxidation.Additionally,the possible photocatalytic mechanism was briefly discussed based on the experimental results.This work identifies viable pathways for developing low-cost heterojunction photocatalysts with highly efficient photocatalytic activity toward improved solar energy conversion.展开更多
Ribosomally synthesized and post-translationally modified peptides(RiPPs)are a class of cyclic or linear peptidic natural products with remarkable structural and functional diversity.Recent advances in genomics and sy...Ribosomally synthesized and post-translationally modified peptides(RiPPs)are a class of cyclic or linear peptidic natural products with remarkable structural and functional diversity.Recent advances in genomics and synthetic biology,are facilitating us to discover a large number of new ribosomal natural products,including lanthipeptides,lasso peptides,sactipeptides,thiopeptides,microviridins,cyanobactins,linear thiazole/oxazole-containing peptides and so on.In this review,we summarize bioinformatic strategies that have been developed to identify and prioritize biosynthetic gene clusters(BGCs)encoding RiPPs,and the genome mining-guided discovery of novel RiPPs.We also prospectively provide a vision of what genomics-guided discovery of RiPPs may look like in the future,especially the discovery of RiPPs from dominant but uncultivated microbes,which will be promoted by the combinational use of synthetic biology and metagenome mining strategies.展开更多
An understanding of the nutrient utilization characteristics of pigs with different feed efficiencies(FEs) will help us to develop new strategies to reduce the costs of pig production.In this study,we selected pigs wi...An understanding of the nutrient utilization characteristics of pigs with different feed efficiencies(FEs) will help us to develop new strategies to reduce the costs of pig production.In this study,we selected pigs with a range of FEs according to two feed conversion ratio models: the feed intake(FI) model,where pigs had the same average daily gains(ADGs) but different FIs,and the ADG model,where pigs had the same FIs but different ADGs.High-FE pigs had a higher abundance of short chain fatty acid(SCFA)-producing bacteria(Lachnospiraceae,Clostridiaceae1,and Coriobacteriaceae) in their caecum in the FI model,and low-FE pigs had a higher abundance of two families(BacteroidalesS247group and Peptococcaceae) and two genera(Anaerotruncus and CandidatusSoleaferrea) in both models.By contrast,high-FE pigs had more goblet cells and higher m RNA expression of insulin-like growth factor 1(IGF-1) in the FI model,and higher mRNA expression of occludin but lower expressions of adenosine monophosphate-activated protein kinase(AMPK)-α2 and peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC1α) in the ADG model.These findings suggest that the presence of SCFA-producing bacteria in the caecum and increased muscular growth may contribute to the high FE of low-FI pigs,while improved intestinal functions and decreased mitochondrial activity in the skeletal muscle are related to the high FE of high-ADG pigs.展开更多
文摘Background: Gastroparesis is one of the complications of diabetes mellitus, and long-term gastroparesis seriously affects patients quality of life. Most of the patients can be relieved after lifestyle improvement and medication, but refractory gastroparesis is difficult to relieve, and is still a challenge in clinical treatment. Aim: To report a case of a patient with diabetic nephropathy combined with refractory gastroparesis, and to analyse the mechanism, diagnosis, severity grading, treatment of refractory gastroparesis in conjunction with a review of the literature, and to investigate the causes of recurrent nausea and vomiting in diabetic nephropathy patients with refractory diabetic gastroparesis and the possible effective treatment options. Case Presentation: The patient was hospitalised for recurrent nausea and vomiting and diagnosed with diabetic nephropathy and gastroparesis. Symptoms recurred after medication and peritoneal dialysis, and the patients symptoms were relieved after multifaceted interventions. Conclusion: Diabetic nephropathy and refractory gastroparesis can both manifest as digestive tract symptoms, and in the face of this complex disease, it is necessary to analyse the various etiological factors and take comprehensive treatment measures.
基金the financial support by the National Natural Science Foundation of China(NSFC) Grants(51702295)。
文摘Rational coupling of hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) catalysts is extremely important for practical overall water splitting,but it is still challenging to construct such bifunctional heterostructures.Herein,we present a metal-organic framework(MOF)-etching strategy to design free-standing and hierarchical hollow CoS_(2)-MoS_(2) heteronanosheet arrays for both HER and OER.Resulting from the controllable etching of MOF by MoO_(4)^(2-) and in-situ sulfuration,the obtained CoS_(2)-MoS_(2) possesses abundant heterointerfaces with modulated local charge distribution,which promote water dissociation and rapid electrocatalytic kinetics.Moreover,the two-dimensional hollow array architecture can not only afford rich surface-active sites,but also facilitate the penetration of electrolytes and the release of evolved H_(2)/O_(2) bubbles.Consequently,the engineered CoS_(2)-MoS_(2) heterostructure exhibits small overpotentials of 82 mV for HER and 266 mV for OER at 10 mA cm^(-2).The corresponding alkaline electrolyzer affords a cell voltage of 1.56 V at 10 mA cm^(-2) to boost overall water splitting,along with robust durability over 24 h, even surpassing the benchmark electrode couple composed of IrO_(2) and Pt/C The present work may provide valuable insights for developing MOF-derived heterogeneous electrocatalysts with tailored interface/surface structure for widespread application in catalysis and other energyrelated areas.
基金financially supported by the National Natural Science Foundation of China (22279122,52042403)the Zhejiang Provincial Natural Science Foundation of China (LZ22B030004)+2 种基金the Ministry of Education,Singapore,under its Academic Research Fund Tier 1 (RG10/22)the National Institute of Education,Singapore,under its Academic Research Fund (RI 1/21 EAH)National Institute of Education,Singapore,under its Start-Up Grant (NIE-SUG4/20AHX)。
文摘Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but water-isolating solid-electrolyte interphase(SEI)films have been developed,however,the required high-purity chemical materials are extremely expensive.In this work,phosphogypsum(PG),an industrial byproduct produced from the phosphoric acid industry,is employed as a multifunctional protective layer to navigate uniform zinc deposition.Theoretical and experimental results demonstrate that PG-derived CaSO_(4)2H_(2)O can act as an artificial SEI layer to provide fast channels for Zn^(2+)transport.Moreover,CaSO_(4)2H_(2)O could release calcium ions(Ca^(2+))due to its relatively high Kspvalue,which have a higher binding energy than that of Zn^(2+)on the Zn surface,thus preferentially adsorbing to the tips of the protuberances to force zinc ions to nucleate at inert region.As a result,the Zn@PG anode achieves a high Coulombic efficiency of 99.5%during 500 cycles and long-time stability over 1000 hours at 1 m A cm^(-2).Our findings will not only construct a low-cost artificial SEI film for practical metal batteries,but also achieve a high-value utilization of phosphogypsum waste.
基金supported by the National Natural Science Foundation of China(52170100,U21A2036)Guangdong Basic and Applied Basic Research Foundation(2022A1515110257).
文摘Microplastics(MPs)degradation due to light radiation,weathering,water erosion and biodegradation might change MPs physical and chemical characteristics and thereby change MPs behaviors in natural environments.This study conducted a comparison investigation on polyvinyl chloride(PVC),polyethylene(PE)and polyamide(PA)degradation in three different environmental conditions,namely simulated UV light,natural light and natural water body.The results showed that degradation of MPs in natural environments is more complex than the case in a controlled experimental condition(such as simulated UV light).In the conditions of natural light and natural water body,MPs are more easily covered by sediments/microorganisms.Particularly in the natural water body,biofilm development is an important factor for MPs degradation and this is dependent on where MPs are located.PVC in the water surface adsorbed more prokaryotes and eukaryotes than those in the water bottom while PE and PA showed the opposite.The research outcomes also show that a complex interaction between MPs and heavy metals in different environments.In simulated UV light,heavy metals tended to leach from MPs while in the natural light and natural water body,heavy metal concentrations of MPs had a higher variability caused by continuous leaching-adsorption behaviors.Those outcomes were expected to contribute to an in-depth understanding of MP degradations and their environmental behaviors.
基金supported by Natural Science Foundation of Zhejiang Province (Grant No. LY20A010017), Natural Science Foundation of Zhejiang Province (Grant No. LDQ23A010001)supported by National Natural Science Foundation of China (Grant No. 11931010)。
文摘In this paper, by using time-weighted global estimates and the Lagrangian approach, we first investigate the global existence and uniqueness of the solution for the 2D inhomogeneous incompressible asymmetric fluids with the initial(angular) velocity being located in sub-critical Sobolev spaces H^(s)(R^(2))(0<s<1) and the initial density being bounded from above and below by some positive constants. The global unique solvability of the 2D incompressible inhomogeneous asymmetric fluids with the initial data in the critical Besov space(u_(0), w_(0))∈˙B^(0)_(2,1)(R^(2))andρ^(−1)−1∈˙B^(ε)_(2/ε),1(R^(2))is established. In particular, the uniqueness of the solution is also obtained without any more regularity assumptions on the initial density which is an improvement on the recent result of Abidi and Gui(2021) for the 2D inhomogeneous incompressible NavierStokes system.
基金the National Natural Science Foundation of China(Nos.52170100 and U21A2036)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110257)the Shenzhen Science and Innovation Commission(No.JCYJ20200109113006046).
文摘Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to organisms.Additionally,compared to original NPs,photodegraded NPs would pose higher toxicity.This is because their relatively higher specific surface areas and the presence of additives which can more easily leach.How original NPs and aged NPs affect plant growth has not been widely investigated.This work chose polyvinyl chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by 10.6%–22.5%),stem length(decreased by 2.8%–8.1%),dry weight(decreased by 6.3%–7.1%)and fresh weight(decreased by 6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosynthesis and absorption of nutrients and hence the decrease in chlorophyll and soluble sugar contents.According to transcriptomic investigation results,the presence of aged PVC-NPs primarily influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway)and phenylpropanoid biosynthesis(downregulated metabolic pathway)of pea seedlings.These results provide an in-depth understanding of how NPs influence the growth of plants.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2024A1515010371)National Natural Science Foundation of China(52170100,U21A2036).
文摘Polyethylene microplastics(PE-MPs)have toxicity to ecological environment,including animals and plants.This study investigated the toxicity of photodegraded PE-MPs on Brassica rapa,which is a typical model plant and only have around a 30-day life cycle.It is noted that the presence of photodegraded PEMPs inhibited Brassica rapa growth since the stem length decreased by 11.94%-51.11%while the fresh weight and dry weight decreased by 18.56%e27.46%and 1.90%-6.91%respectively,compared to the blank group.PE-MPs receiving more light radiation became more hydrophobic.This inhibited PE-MPs entering the plant body along with the process of plant absorbing water.Furthermore,when PE-MPs were located in the lower soil layers,Brassica rapa reaching them needs a longer time,hence showing lower toxicity effect than the case of PE-MPs located in the upper soil layer.The research outcomes also indicated that malondialdehyde(MDA)contents in photodegraded PE-MPs exposure group increased by 1.37%-7.28%while the catalase activity(CAT)increased by 60.11%.This means that PE-MPs caused oxidative stress response in plants,inducing plants to resist external stress.Transcriptomic analysis results showed that Brassica rapa,which was affected by PE-MPs,significantly up-regulated genes related to the plant-pathogen interaction pathway while the ribosome pathway genes were significantly downregulated.This led to a decrease in growth rate and a decrease in the homeostatic level of the ribosomal subunit and hence resulting in abnormal leaf vein development.These conclusions indicated the toxic effect and damage mechanism of photodegraded PE-MPs on Brassica rapa.The novelty of this study was to use both univariate analysis and transcriptomic analysis to investigate how photodegraded PE-MPs exert toxicity on Brassica rapa.The results can provide a theoretical basis for revealing the influence of MPs on plant growth.
基金supported by the National Basic Research Program of China (2010CB234602)the National Natural Science Foundation of China (20636030,20706011 & 20876033)+1 种基金the Basic Research Program of Tianjin (07JCZDJC00100)the Education Bureau of Hebei Province (2005005D)
文摘MgAPO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 ratio.The samples were characterized by XRD,SEM,solid state NMR,FT-IR and NH3-TPD.Using MgAPO-5 as acidic supports,bifunctional Pt/MgAPO-5 catalysts were prepared for hydrogenation of nitrobenzene to p-aminophenol (PAP).The results showed that the MgO/Al2O3 ratios influenced the Mg content and the acidity of MgAPO-5 samples,thereby greatly affecting the catalytic performance of Pt/MgAPO-5 catalysts.The selectivity to PAP over Pt/MgAPO-5 was dependent on the amount of strong acid sites of MgAPO-5.When the MgO/Al2O3 molar ratio was 0.5,the synthesized MgAPO-5 sample exhibited the largest amount of strong acid and a highest PAP yield of 41.1% was achieved over Pt/MgAPO-5 catalyst.
基金funded by the National Key Research and Development Program of China (2016YFC0300200)the National Natural Science Foundation of China (21975229)the Natural Science Foundation of Zhejiang Province (Y19B060003)
文摘In this study,a g-C_(3)N_(4)-Cu_(2)O-TiO_(2) photocatalyst with a novel three-dimensional ordered macroporous(3DOM)structure was successfully prepared using a sacrificial template strategy and a photodeposition method.The influence of the special porous structure with cross pore channels on the photocatalytic properties of the as-prepared sample was studied in detail.Compared with the original photocatalyst(TiO_(2) with 3 wt%Pt),g-C_(3)N_(4)-Cu_(2)O-TiO_(2) exhibited a higher specific surface area and more active sites,thus accelerating the separation efficiency of the photogenerated electron-hole pair.Consequently,the as-prepared photocatalyst showed good photocatalytic performance,reaching a maximum hydrogen production rate of 12,108μmol g^(-1) h^(-1) and approximately five times higher than that of the pristine comparison sample.The enhanced photoactivity of the g-C_(3)N_(4)-Cu_(2)O-TiO_(2) heterojunction can be ascribed to its double p-n heterojunction and robust porous structure,where the photodeposited Cu_(2)O plays a synergistic catalytic role in the photocatalytic process and the outer clad g-C_(3)N_(4) layer prevents Cu_(2)O oxidation.Additionally,the possible photocatalytic mechanism was briefly discussed based on the experimental results.This work identifies viable pathways for developing low-cost heterojunction photocatalysts with highly efficient photocatalytic activity toward improved solar energy conversion.
基金Z.Zhong,B.He,and Y-X Li acknowledge a partial financial support from the National Key R&D Program of China(2018YFA0903200)Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(SMSEGL20SC01)J.Li acknowledges a partial financial support by a National Institutes of Health(NIH)grant P20GM103641 and a National Science Foundation EPSCoR Program OIA-1655740.
文摘Ribosomally synthesized and post-translationally modified peptides(RiPPs)are a class of cyclic or linear peptidic natural products with remarkable structural and functional diversity.Recent advances in genomics and synthetic biology,are facilitating us to discover a large number of new ribosomal natural products,including lanthipeptides,lasso peptides,sactipeptides,thiopeptides,microviridins,cyanobactins,linear thiazole/oxazole-containing peptides and so on.In this review,we summarize bioinformatic strategies that have been developed to identify and prioritize biosynthetic gene clusters(BGCs)encoding RiPPs,and the genome mining-guided discovery of novel RiPPs.We also prospectively provide a vision of what genomics-guided discovery of RiPPs may look like in the future,especially the discovery of RiPPs from dominant but uncultivated microbes,which will be promoted by the combinational use of synthetic biology and metagenome mining strategies.
基金supported by the National Natural Science Foundation of China(31630074)the Beijing Municipal Natural Science Foundation(S170001)+2 种基金the National Key Research and Development Program of China(2016YFD0500506)the 111 Project(B16044)Jinxinnong Animal Science Developmental Foundation and Hunan Co-Innovation Center of Animal Production Safety
文摘An understanding of the nutrient utilization characteristics of pigs with different feed efficiencies(FEs) will help us to develop new strategies to reduce the costs of pig production.In this study,we selected pigs with a range of FEs according to two feed conversion ratio models: the feed intake(FI) model,where pigs had the same average daily gains(ADGs) but different FIs,and the ADG model,where pigs had the same FIs but different ADGs.High-FE pigs had a higher abundance of short chain fatty acid(SCFA)-producing bacteria(Lachnospiraceae,Clostridiaceae1,and Coriobacteriaceae) in their caecum in the FI model,and low-FE pigs had a higher abundance of two families(BacteroidalesS247group and Peptococcaceae) and two genera(Anaerotruncus and CandidatusSoleaferrea) in both models.By contrast,high-FE pigs had more goblet cells and higher m RNA expression of insulin-like growth factor 1(IGF-1) in the FI model,and higher mRNA expression of occludin but lower expressions of adenosine monophosphate-activated protein kinase(AMPK)-α2 and peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC1α) in the ADG model.These findings suggest that the presence of SCFA-producing bacteria in the caecum and increased muscular growth may contribute to the high FE of low-FI pigs,while improved intestinal functions and decreased mitochondrial activity in the skeletal muscle are related to the high FE of high-ADG pigs.