Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution rea...Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.展开更多
Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using...Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.展开更多
Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and e...Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and electrical conductivity. In recent years, HEA nanoparticles(HEA-NPs) were paid much attention to in the field of catalysis for the promoted catalytic activity. Furthermore, the various ratios among the metal components and tunable bulk and surface structures enable HEAs have big room to enhance the catalytic performance. Especially, noble-metal-based HEAs displayed significantly improved performance in electrocatalysis, where the ‘core effects’ were employed to explain the superior catalytic activity. However, it is insufficient to understand the essential mechanism or further guide the design of electrocatalysts. Structure–property relationship should be disclosed for the catalysis on HEA-NPs to accelerate the process of seeking high effective and efficient electrocatalysts. Therefore, we summarized the recent advances of noble-metal-based HEA-NPs applied to electrocatalysis, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, methanol oxidation reaction, ethanol oxidation reaction, formic acid oxidation reaction, hydrogen oxidation reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. For each electrocatalytic reaction, the reaction mechanism and catalyst structure were presented, and then the structure–property relationship was elaborated. The review begins with the development, concept, four ‘core effect’ and synthesis methods of HEAs. Next,the electrocatalytic reactions on noble-metal-based HEA-NPs are summarized and discussed independently. Lastly, the main views and difficulties pertaining to structure–property relationship for HEAs are discussed.展开更多
Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of gra...Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of graphitic carbon for the oxygen-reduction reaction （ORR） both in acidic and alkaline media, and the materials exhibited high electrocatalytic activity, long-term stability, and excellent tolerance to crossover effects especially in alkaline media. Quantum mechanics calculations with the density functional theory demonstrated that the changes in charge density and energetic characteristics of frontier orbitals for the P-doped graphene sheet could facilitate the ORR.展开更多
Inflammation is a defensive response of living tissues to damaging agents,which exists in two forms,acute inflammation and chronic inflammation,and chronic inflammation is closely related to arthritis.Currently,the co...Inflammation is a defensive response of living tissues to damaging agents,which exists in two forms,acute inflammation and chronic inflammation,and chronic inflammation is closely related to arthritis.Currently,the commonly prescribed anti-inflammatory medications are greatly limited by high incidence of gastrointestinal erosions in the clinical applications.Rhein,a bioactive constituent of anthraquinone,exhibits excellent anti-inflammatory activities and therapeutic effects on arthritis with less gastrointestinal damages.Although there are numbers of studies on anti-inflammatory effects and mechanisms of rhein in the last few decades,to the best of our knowledge,only a few review articles pay attention to the interactive relationships of rhein on multiple inflammatory signaling pathways and cellular processes from a comprehensive perspective.Herein,we summarized anti-inflammatory effects and mechanisms of rhein and its practical applications in the treatment of arthritis,thereby providing a reference for its basic researches and clinical applications.展开更多
The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regar...The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regard,the efficient conversion of carbonates to value-added products will provide an economically viable method for the sustainable usage of carbon compounds.Herein,we report a promising solution involving the use of a glycerol and ethanol mixture as a hydrogen donor in the dry reforming process with CaCO3 to produce syngas.A series of metal active components,including Ni,Fe,Co,Cu,Pt,Pd,Ru,and Rh,was used to promote this reaction.Ni showed comparable performance with that of Pd,but outperformed Co,Fe,Cu,Rh,Ru,and Pt.Approximately 100%conversion of glycerol and ethanol,~92%selectivity of synthesis gas(H2 and CO),and a H2/CO ratio of^1.2 were achieved over CaCO3 containing10 wt%Ni(10Ni-CaCO3).Meanwhile,the CO2 concentration was less than 5 vol%,indicating that most of the CO2 captured by the carbonate can be transformed into chemicals;however,they cannot simply be emitted.The CO2 released from the decomposition of CaCO3 not only adjusted the ratio of H2 to CO but also eliminated cokes to guarantee the CO2 absorption-conversion cyclic stability in the absence of steam and at high temperatures.展开更多
Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reform...Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reforming reaction of ethanol （OSRE）. The conversion of ethanol and selectivites for hydrogen and byproducts such as methane, ethylene and acetaldehyde were studied. It was found that lanthana alone possessed considerable activity for the ATRE reaction, which could be used as a functional support for ATRE catalysts. It was demonstrated that Ir/La2O3 prevented the formation of methane, and Rh/La2O3 encumbered the production of ethylene and acetaldehyde. ATRE reaction was carried out over La2O3-supported catalysts （Ir/La2O3） with good stability on stream, high conversion, and excellent hydrogen selectivity approaching thermodynamic limit under autothermal condition. Typically, 3.4H2 molecules can be extracted from a pair of ethanol and water molecules over Ir（5wt%）/La2O3. The results presented in this paper indicate that Ir/La2O3 can be used as a promising catalyst for hydrogen production via ATRE reaction from renewable ethanol.展开更多
BACKGROUND： Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE： To investigate the dynamic changes of Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in the rat b...BACKGROUND： Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE： To investigate the dynamic changes of Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in the rat brain following transient global cerebral ischemia-reperfusion （IR）, as well as the effects of hyperbaric oxygen （HBO） treatment. DESIGN, TIME AND SETTING： A randomized and controlled animal study was performed in the Department of Biochemistry and Molecular Biology, Capital Medical University between February and December 2006. MATERIALS： Clean-grade, female, Sprague Dawley rats were provided by the Animal Research Department of Capital Medical University （License number： SYXK11-00-0047）. Na^＋-K^＋-ATPase and Ca^2＋-ATPase kits were provided by Nanjing Jiancheng Bioengineering Institute （Nanjing, China）. A hyperbaric oxygen chamber （DWC150-300） was supplied by Shanghai 701 Medical Oxygen Chamber Factory （Shanghai, China）. METHODS： Sixty-three rats were randomly divided into nine groups： sham operated group （sham-O） as control, groups of IR, and groups treated with hyperbaric oxygen （HBO） after IR. Animal from the IR and HBO groups were sacrificed after four different survival intervals of 6, 24, 48 and 96 hours, respectively. Each group consisted of seven rats. The rats of HBO groups were placed into the hyperbaric chamber. The HBO chamber was flushed with pure oxygen for 5 minutes, followed by a gradual rise in pressure over 5 minutes and stabilization at 0.2 MPa. Then, pure oxygen was supplied for 45 minutes in stabilized pressure, followed by gradually reduced pressure over 15 minutes. The rats of the 6-h HBO group were placed into the HBO chamber following reperfusion for 3 hours on the first day, which was repeated on three consecutive days, always at the same time. Rats in the sham-O group and IR group remained under normal atmospheric pressure. MAIN OUTCOME MEASURES： The Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in rat brain homogenate was detected by the ammonium molybdate assay method. RESULTS： All 63 rats were included in the final analysis. Alter 6 hours, Na^＋-K^＋-ATPase activity was significantly greater in HBO animals, compared with IR animals （P 〈 0.05） and sham-O controls （P〈 0.01）. In both, the HBO group and IR group, Na^＋-K^＋-ATPase activity returned to normal levels after 24 hours （P 〉 0.05）. At 48 and 96 hours, Na^＋-K^＋-ATPase activity was significantly greater in HBO and IR animals, compared with sham-O animals （P 〈 0.05）. Ca^2＋-ATPase activity was significantly greater in the HBO group after 6 hours, compared with the sham-O group （P 〈 0.01 ）, and returned to normal levels at 24 and 96 hours （P 〉 0.05）. In the IR group, Ca^2＋-ATPase activity was significantly higher after 6 hours than in the sharn-O group （P〈 0.01）, and returned to normal levels after 24 hours （P 〉 0.05）. CONCLUSION： The Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in IR groups increased during the acute and the delayed phase following transient global cerebral IR. HBO treatment not only increased Na^＋-K^＋-ATPase activity at the acute stage, but also induced a faster recovery of Ca^2＋-ATPase activity.展开更多
We report on a new type of amperometric glucose biosensor that was made by integration of glucose oxidase (GOD) with palladium nanoparticles/reduce graphene oxide (Pd/RGO) nanocomposite. The Pd/RGO was prepared by a o...We report on a new type of amperometric glucose biosensor that was made by integration of glucose oxidase (GOD) with palladium nanoparticles/reduce graphene oxide (Pd/RGO) nanocomposite. The Pd/RGO was prepared by a one-step reduction method in which the palladium nanoparticles and the reduced graphene oxide (RGO) were simultaneously accomplished from the reduction of dispersed solution of PdCl2 and graphite oxide (GO) with hydrazine. The asprepared nanocomposite exhibits favorable electrocatalytic activities towards the oxidation of H2O2, which makes it a good platform for the construction of the glucose biosensor. The analytical performance of the glucose biosensor is fully evaluated. It shows good analytical properties in terms of a short response time (3 s), high sensitivity (14.1 μA/mM), and low detection limit (0.034 mM). In addition, the effects of pH value, applied potential, electroactive interference and the stability of the biosensor were discussed as well.展开更多
The human immunodeficiency virus （HIV） lentiviral vector is an ideal vector for gene therapy. In the present study, the wild-type HIV-1 genome was segregated into four plasmids, and an optimized novel HIV-1 lentivir...The human immunodeficiency virus （HIV） lentiviral vector is an ideal vector for gene therapy. In the present study, the wild-type HIV-1 genome was segregated into four plasmids, and an optimized novel HIV-1 lentiviral vector containing green fluorescent protein and vesicular stomatitis virus G pseudo-capsule was constructed. The plasmids were pHR-CMV-EGFP, pCMVΔ8.9, pRSV-Rev, pCMV-VSV-G. The four plasmid system was co-transfected into 293T cells, and green fluorescent protein expression was observed. The present study obtained lentiviral particles by high-speed centrifugation, and the lentiviral particle titer was 4 × 108 TU/mL after centrifugation. Thus, an optimized novel HIV-1 lentiviral vector was successfully constructed.展开更多
Semiconductive two dimensional(2D)materials have attracted significant research attention due to their rich band structures and promising potential for next-generation electrical devices.In this work,we investigate th...Semiconductive two dimensional(2D)materials have attracted significant research attention due to their rich band structures and promising potential for next-generation electrical devices.In this work,we investigate the MoS2 field-effect transistors(FETs)with a dual-gated(DG)architecture,which consists of symmetrical thickness for back gate(BG)and top gate(TG)dielectric.The thickness-dependent charge transport in our DG-MoS2 device is revealed by a four-terminal electrical measurement which excludes the contact influence,and the TCAD simulation is also applied to explain the experimental data.Our results indicate that the impact of quantum confinement effect plays an important role in the charge transport in the MoS2 channel,as it confines charge carriers in the center of the channel,which reduces the scattering and boosts the mobility compared to the single gating case.Furthermore,temperature-dependent transfer curves reveal that multi-layer MoS2 DG-FET is in the phonon-limited transport regime,while single layer MoS2 shows typical Coulomb impurity limited regime.展开更多
Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctiona...Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctional catalyst derived from hydrotalcite-like materials,we demonstrate the feasibility of producing high-purity H_(2)(~96%)with 0.9 mol H_(2) mol^(-1) C yield via the sorption enhanced steam reforming(SESR)of BL.The SESRBL performance in terms of H_(2) production maintained stable for 5 cycles,but declined from the 6th cycle.XRD,Raman spectroscopy,elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst.It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL,while deposition of Na and K from the BL might also be responsible for the declined performance.On the other hand,it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO_(3).Our results highlight a promising alternative for BL treatment and H_(2) production,thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.展开更多
OBJECTIVE： TO summarize the relationship between heat shock protein 70 （HSP70） and cerebra ischemia. DATA SOURCES： An online search of Medline database was undertaken to identify relevant articles published in Eng...OBJECTIVE： TO summarize the relationship between heat shock protein 70 （HSP70） and cerebra ischemia. DATA SOURCES： An online search of Medline database was undertaken to identify relevant articles published in English from January 1980 to December 2005 by using the keywords of ＂heat shock protein 70, ischemia＂. Meanwhile, Chinese relevant articles published from January 2000 to December 2005 were searched in China National Knowledge Infrastructure （CNKI） database and Chinese Journal of Clinical Rehabilitation with the keywords of ＂heat shock protein 70, cerebral ischemia＂ in Chinese. STUDY SELECTION ： More than 100 related articles were screened, and 29 references mainly about HSP70 and cerebral ischemia were selected, including basic and clinical researches. As to the articles with similar content, those published in the authoritative journals in recent 3 years were preferential. DATA EXTRACTION： A total of 29 articles were collected and classified according to the structure, function and clinical application of HSP70. Among them, 1 article is about the structure of HSP70, 27 about the relationship between HSP70 and cerebral ischemia, and 2 about the clinical application of HSP70. DATA SYNTHESIS： HSP70 is one of the most conservative proteins during biological evolution. Experiments in cerebral ischemia revealed that HSP70 expression was time-dependent, also correlated with the injured site and severity. The cerebral ischemia induced HSP70 gene expression in hippocampus of gerbil had protection to tolerance of fatal ischemic injury for neurons. The increase of HSP70 expression may be one of the endogenous protective mechanisms during cerebral ischemia, and can effectively alleviate cerebral ischemia. Thus HSP70 protein and HSP70 mRNA have been taken as important indexes extensively applied in the basic study of cerebral ischemia by some scholars abroad. CONCLUSION： HSP70 plays a protective role in cerebral ischemia, and a deeper research into the biological function of HSP70 will provide a new way for the therapy of cerebral ischemia.展开更多
In 2010, No.1 document of central government demanded strengthening mediation and settlement of ownership of rural collective land, to complete confirmation of right and registration and issue of certificate of rural ...In 2010, No.1 document of central government demanded strengthening mediation and settlement of ownership of rural collective land, to complete confirmation of right and registration and issue of certificate of rural collective land in 3 years. However, the mediation and settlement of land ownership in China still remain at starting stage, and there are many problems in both theory and practice. In this situation, this paper summarizes current situations of disputes about ownership of collective land in Beijing, analyzes causes of disputes, introduces existing working mechanism, methods and problems of dispute mediation and settlement, and finally presents feasible recommendations, in the hope of providing guidance for mediation and settlement of land ownership disputes.展开更多
[Objectives] The paper was to explore the control effects of different botanical pesticides against Empoasca pirisuga Matumura. [Methods] 5% Eucalyptol SL, 0.5% matrine SL and 50% thiacloprid WDG were used to control ...[Objectives] The paper was to explore the control effects of different botanical pesticides against Empoasca pirisuga Matumura. [Methods] 5% Eucalyptol SL, 0.5% matrine SL and 50% thiacloprid WDG were used to control E. pirisuga , and the decline rate of insect population was investigated. [Results] Eucalyptol had good control effect on E. pirisuga , with slow effect but long duration. It was harmless to natural enemies in tea gardens, with high safety and no chemical injury. [Conclusions] The study provides a theoretical basis for the application of botanical pesticides in tea production.展开更多
[Objectives]This study was conducted to explore the application effects of Sinochem microbial organic fertilizer on tea plants.[Methods]Through the experiment and demonstration of Sinochem microbial organic fertilizer...[Objectives]This study was conducted to explore the application effects of Sinochem microbial organic fertilizer on tea plants.[Methods]Through the experiment and demonstration of Sinochem microbial organic fertilizer,its effects on the yield and quality of tea and the physical and chemical quality of soil were explored.[Results]Compared with the conventional organic fertilizer cake fertilizer,the fertilizer could increase the weight of freshly picked bud leaves,increase the yield of tea,and thus promote the growth of tea plants.It increased the contents of chlorophyll components,amino acids and tea polyphenols,the main functional substances of tea,which was conducive to improving the internal quality of tea.It improved the physical and chemical properties of soil,and increased the contents of organic matter,alkali-hydrolyzable nitrogen and available phosphorus in tea garden soil.It also had a good effect in improving soil environmental health indexes and physical and chemical properties,and did not contain heavy metals and plant growth hormones.[Conclusions]This study provides a theoretical basis for the popularization and application of Sinochem microbial organic fertilizer.展开更多
Noble metal Ag nanoparticles with unique surface plasmon resonance property have attracted much attention recently in the field of photocatalysis. Based on the advantages of Ag nanoparticles and semiconductor CeO2, a ...Noble metal Ag nanoparticles with unique surface plasmon resonance property have attracted much attention recently in the field of photocatalysis. Based on the advantages of Ag nanoparticles and semiconductor CeO2, a novel plasmonic photocatalyst Ag-AgCl/CeO2 was prepared with a facile route. The as-prepared samples were characterized using scanning and transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffusion re?ection spectroscopy. This metal-semiconductor nanocomposite plasmonic photocatalyst exhibited a high visible-light photocatalytic activity and good stability for photocatalytic degradation of methyl orange in water. Ag-AgCl/CeO2 will be a potentially promising plasmonic photocatalysts for organic pollutant degradation and water purification.展开更多
Nicotine is widely recognized as the primary contributor to tobacco dependence.Previous studies have indicated that molecular and behavioral responses to nicotine are primarily mediated by ventral tegmental area(VTA)n...Nicotine is widely recognized as the primary contributor to tobacco dependence.Previous studies have indicated that molecular and behavioral responses to nicotine are primarily mediated by ventral tegmental area(VTA)neurons,and accumulating evidence suggests that glia play prominent roles in nicotine addiction.However,VTA neurons and glia have yet to be characterized at the transcriptional level during the progression of nicotine self-administration.Here,a male mouse model of nicotine self-administration is established and the timing of three critical phases(pre-addiction,addicting,and post-addiction phase)is characterized.Single-nucleus RNA sequencing in the VTA at each phase is performed to comprehensively classify specific cell subtypes.Adaptive changes occurred during the addicting and post-addiction phases,with the addicting phase displaying highly dynamic neuroplasticity that profoundly impacts the transcription in each cell subtype.Furthermore,significant transcriptional changes in energy metabolism-related genes are observed,accompanied by notable structural alterations in neuronal mitochondria during the progression of nicotine self-administration.The results provide insights into mechanisms underlying the progression of nicotine addiction,serving as an important resource for identifying potential molecular targets for nicotine cessation.展开更多
基金financially supported by National Natural Science Foundation of China(No.22209049,22075102,22005120)Natural Science Foundation of Guangdong Province(No.2023A1515012804)Fundamental Research Funds for the Central Universities(No.2022ZYGXZR048)。
文摘Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.
基金financial support from the National Natural Science Foundation of China (Nos. 21476089, 21373091)the Provincial Science and Technology Project of Guangdong (No. 2014A030312007)
文摘Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.
基金supported by the National Natural Science Foundation of China (21676100, 22008076)the Guangdong Natural Science Foundation (2017A030312005)。
文摘Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and electrical conductivity. In recent years, HEA nanoparticles(HEA-NPs) were paid much attention to in the field of catalysis for the promoted catalytic activity. Furthermore, the various ratios among the metal components and tunable bulk and surface structures enable HEAs have big room to enhance the catalytic performance. Especially, noble-metal-based HEAs displayed significantly improved performance in electrocatalysis, where the ‘core effects’ were employed to explain the superior catalytic activity. However, it is insufficient to understand the essential mechanism or further guide the design of electrocatalysts. Structure–property relationship should be disclosed for the catalysis on HEA-NPs to accelerate the process of seeking high effective and efficient electrocatalysts. Therefore, we summarized the recent advances of noble-metal-based HEA-NPs applied to electrocatalysis, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, methanol oxidation reaction, ethanol oxidation reaction, formic acid oxidation reaction, hydrogen oxidation reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. For each electrocatalytic reaction, the reaction mechanism and catalyst structure were presented, and then the structure–property relationship was elaborated. The review begins with the development, concept, four ‘core effect’ and synthesis methods of HEAs. Next,the electrocatalytic reactions on noble-metal-based HEA-NPs are summarized and discussed independently. Lastly, the main views and difficulties pertaining to structure–property relationship for HEAs are discussed.
基金supported by the Guangdong Provincial Science and Technology Project of China (2011B010400016)China Postdoctoral Science Foundation (No. 20110490878)
文摘Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of graphitic carbon for the oxygen-reduction reaction （ORR） both in acidic and alkaline media, and the materials exhibited high electrocatalytic activity, long-term stability, and excellent tolerance to crossover effects especially in alkaline media. Quantum mechanics calculations with the density functional theory demonstrated that the changes in charge density and energetic characteristics of frontier orbitals for the P-doped graphene sheet could facilitate the ORR.
基金supported by Drug Innovation Major Project(Grant Nos.2018ZX09711001-001-015,2018ZX09711001-003-022)CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-3-007).
文摘Inflammation is a defensive response of living tissues to damaging agents,which exists in two forms,acute inflammation and chronic inflammation,and chronic inflammation is closely related to arthritis.Currently,the commonly prescribed anti-inflammatory medications are greatly limited by high incidence of gastrointestinal erosions in the clinical applications.Rhein,a bioactive constituent of anthraquinone,exhibits excellent anti-inflammatory activities and therapeutic effects on arthritis with less gastrointestinal damages.Although there are numbers of studies on anti-inflammatory effects and mechanisms of rhein in the last few decades,to the best of our knowledge,only a few review articles pay attention to the interactive relationships of rhein on multiple inflammatory signaling pathways and cellular processes from a comprehensive perspective.Herein,we summarized anti-inflammatory effects and mechanisms of rhein and its practical applications in the treatment of arthritis,thereby providing a reference for its basic researches and clinical applications.
基金supported by the Guangdong Natural Science Foundation(2017A030312005)Science and Technology Program of Guangzhou City(201707010058)。
文摘The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regard,the efficient conversion of carbonates to value-added products will provide an economically viable method for the sustainable usage of carbon compounds.Herein,we report a promising solution involving the use of a glycerol and ethanol mixture as a hydrogen donor in the dry reforming process with CaCO3 to produce syngas.A series of metal active components,including Ni,Fe,Co,Cu,Pt,Pd,Ru,and Rh,was used to promote this reaction.Ni showed comparable performance with that of Pd,but outperformed Co,Fe,Cu,Rh,Ru,and Pt.Approximately 100%conversion of glycerol and ethanol,~92%selectivity of synthesis gas(H2 and CO),and a H2/CO ratio of^1.2 were achieved over CaCO3 containing10 wt%Ni(10Ni-CaCO3).Meanwhile,the CO2 concentration was less than 5 vol%,indicating that most of the CO2 captured by the carbonate can be transformed into chemicals;however,they cannot simply be emitted.The CO2 released from the decomposition of CaCO3 not only adjusted the ratio of H2 to CO but also eliminated cokes to guarantee the CO2 absorption-conversion cyclic stability in the absence of steam and at high temperatures.
基金supported by the National Natural Science Foundation of China (No. 50675070)
文摘Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reforming reaction of ethanol （OSRE）. The conversion of ethanol and selectivites for hydrogen and byproducts such as methane, ethylene and acetaldehyde were studied. It was found that lanthana alone possessed considerable activity for the ATRE reaction, which could be used as a functional support for ATRE catalysts. It was demonstrated that Ir/La2O3 prevented the formation of methane, and Rh/La2O3 encumbered the production of ethylene and acetaldehyde. ATRE reaction was carried out over La2O3-supported catalysts （Ir/La2O3） with good stability on stream, high conversion, and excellent hydrogen selectivity approaching thermodynamic limit under autothermal condition. Typically, 3.4H2 molecules can be extracted from a pair of ethanol and water molecules over Ir（5wt%）/La2O3. The results presented in this paper indicate that Ir/La2O3 can be used as a promising catalyst for hydrogen production via ATRE reaction from renewable ethanol.
基金Science and Technology Development Program of Beijing Education Committee, No.KM200510025004
文摘BACKGROUND： Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE： To investigate the dynamic changes of Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in the rat brain following transient global cerebral ischemia-reperfusion （IR）, as well as the effects of hyperbaric oxygen （HBO） treatment. DESIGN, TIME AND SETTING： A randomized and controlled animal study was performed in the Department of Biochemistry and Molecular Biology, Capital Medical University between February and December 2006. MATERIALS： Clean-grade, female, Sprague Dawley rats were provided by the Animal Research Department of Capital Medical University （License number： SYXK11-00-0047）. Na^＋-K^＋-ATPase and Ca^2＋-ATPase kits were provided by Nanjing Jiancheng Bioengineering Institute （Nanjing, China）. A hyperbaric oxygen chamber （DWC150-300） was supplied by Shanghai 701 Medical Oxygen Chamber Factory （Shanghai, China）. METHODS： Sixty-three rats were randomly divided into nine groups： sham operated group （sham-O） as control, groups of IR, and groups treated with hyperbaric oxygen （HBO） after IR. Animal from the IR and HBO groups were sacrificed after four different survival intervals of 6, 24, 48 and 96 hours, respectively. Each group consisted of seven rats. The rats of HBO groups were placed into the hyperbaric chamber. The HBO chamber was flushed with pure oxygen for 5 minutes, followed by a gradual rise in pressure over 5 minutes and stabilization at 0.2 MPa. Then, pure oxygen was supplied for 45 minutes in stabilized pressure, followed by gradually reduced pressure over 15 minutes. The rats of the 6-h HBO group were placed into the HBO chamber following reperfusion for 3 hours on the first day, which was repeated on three consecutive days, always at the same time. Rats in the sham-O group and IR group remained under normal atmospheric pressure. MAIN OUTCOME MEASURES： The Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in rat brain homogenate was detected by the ammonium molybdate assay method. RESULTS： All 63 rats were included in the final analysis. Alter 6 hours, Na^＋-K^＋-ATPase activity was significantly greater in HBO animals, compared with IR animals （P 〈 0.05） and sham-O controls （P〈 0.01）. In both, the HBO group and IR group, Na^＋-K^＋-ATPase activity returned to normal levels after 24 hours （P 〉 0.05）. At 48 and 96 hours, Na^＋-K^＋-ATPase activity was significantly greater in HBO and IR animals, compared with sham-O animals （P 〈 0.05）. Ca^2＋-ATPase activity was significantly greater in the HBO group after 6 hours, compared with the sham-O group （P 〈 0.01 ）, and returned to normal levels at 24 and 96 hours （P 〉 0.05）. In the IR group, Ca^2＋-ATPase activity was significantly higher after 6 hours than in the sharn-O group （P〈 0.01）, and returned to normal levels after 24 hours （P 〉 0.05）. CONCLUSION： The Na^＋-K^＋-ATPase and Ca^2＋-ATPase activity in IR groups increased during the acute and the delayed phase following transient global cerebral IR. HBO treatment not only increased Na^＋-K^＋-ATPase activity at the acute stage, but also induced a faster recovery of Ca^2＋-ATPase activity.
文摘We report on a new type of amperometric glucose biosensor that was made by integration of glucose oxidase (GOD) with palladium nanoparticles/reduce graphene oxide (Pd/RGO) nanocomposite. The Pd/RGO was prepared by a one-step reduction method in which the palladium nanoparticles and the reduced graphene oxide (RGO) were simultaneously accomplished from the reduction of dispersed solution of PdCl2 and graphite oxide (GO) with hydrazine. The asprepared nanocomposite exhibits favorable electrocatalytic activities towards the oxidation of H2O2, which makes it a good platform for the construction of the glucose biosensor. The analytical performance of the glucose biosensor is fully evaluated. It shows good analytical properties in terms of a short response time (3 s), high sensitivity (14.1 μA/mM), and low detection limit (0.034 mM). In addition, the effects of pH value, applied potential, electroactive interference and the stability of the biosensor were discussed as well.
基金the National Natural Science Foundation of China, No. 30770755
文摘The human immunodeficiency virus （HIV） lentiviral vector is an ideal vector for gene therapy. In the present study, the wild-type HIV-1 genome was segregated into four plasmids, and an optimized novel HIV-1 lentiviral vector containing green fluorescent protein and vesicular stomatitis virus G pseudo-capsule was constructed. The plasmids were pHR-CMV-EGFP, pCMVΔ8.9, pRSV-Rev, pCMV-VSV-G. The four plasmid system was co-transfected into 293T cells, and green fluorescent protein expression was observed. The present study obtained lentiviral particles by high-speed centrifugation, and the lentiviral particle titer was 4 × 108 TU/mL after centrifugation. Thus, an optimized novel HIV-1 lentiviral vector was successfully constructed.
基金supported by the National Key Research and Development Program of China(2016YFA0203900,2018YFA0306101)the National Natural Science Foundation of China(Grant No.91964202)Shanghai Municipal Science and Technology Commission(18JC1410300)。
文摘Semiconductive two dimensional(2D)materials have attracted significant research attention due to their rich band structures and promising potential for next-generation electrical devices.In this work,we investigate the MoS2 field-effect transistors(FETs)with a dual-gated(DG)architecture,which consists of symmetrical thickness for back gate(BG)and top gate(TG)dielectric.The thickness-dependent charge transport in our DG-MoS2 device is revealed by a four-terminal electrical measurement which excludes the contact influence,and the TCAD simulation is also applied to explain the experimental data.Our results indicate that the impact of quantum confinement effect plays an important role in the charge transport in the MoS2 channel,as it confines charge carriers in the center of the channel,which reduces the scattering and boosts the mobility compared to the single gating case.Furthermore,temperature-dependent transfer curves reveal that multi-layer MoS2 DG-FET is in the phonon-limited transport regime,while single layer MoS2 shows typical Coulomb impurity limited regime.
基金This work was supported by the Guangdong Natural Science Foundation(2017A030312005)Science and Technology Program of Guangzhou City(201707010058).
文摘Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctional catalyst derived from hydrotalcite-like materials,we demonstrate the feasibility of producing high-purity H_(2)(~96%)with 0.9 mol H_(2) mol^(-1) C yield via the sorption enhanced steam reforming(SESR)of BL.The SESRBL performance in terms of H_(2) production maintained stable for 5 cycles,but declined from the 6th cycle.XRD,Raman spectroscopy,elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst.It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL,while deposition of Na and K from the BL might also be responsible for the declined performance.On the other hand,it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO_(3).Our results highlight a promising alternative for BL treatment and H_(2) production,thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.
基金a grant from Sci-entific and Technological Devel-opmental Program of Beijing E-ducation Committee, No.KM200510025004
文摘OBJECTIVE： TO summarize the relationship between heat shock protein 70 （HSP70） and cerebra ischemia. DATA SOURCES： An online search of Medline database was undertaken to identify relevant articles published in English from January 1980 to December 2005 by using the keywords of ＂heat shock protein 70, ischemia＂. Meanwhile, Chinese relevant articles published from January 2000 to December 2005 were searched in China National Knowledge Infrastructure （CNKI） database and Chinese Journal of Clinical Rehabilitation with the keywords of ＂heat shock protein 70, cerebral ischemia＂ in Chinese. STUDY SELECTION ： More than 100 related articles were screened, and 29 references mainly about HSP70 and cerebral ischemia were selected, including basic and clinical researches. As to the articles with similar content, those published in the authoritative journals in recent 3 years were preferential. DATA EXTRACTION： A total of 29 articles were collected and classified according to the structure, function and clinical application of HSP70. Among them, 1 article is about the structure of HSP70, 27 about the relationship between HSP70 and cerebral ischemia, and 2 about the clinical application of HSP70. DATA SYNTHESIS： HSP70 is one of the most conservative proteins during biological evolution. Experiments in cerebral ischemia revealed that HSP70 expression was time-dependent, also correlated with the injured site and severity. The cerebral ischemia induced HSP70 gene expression in hippocampus of gerbil had protection to tolerance of fatal ischemic injury for neurons. The increase of HSP70 expression may be one of the endogenous protective mechanisms during cerebral ischemia, and can effectively alleviate cerebral ischemia. Thus HSP70 protein and HSP70 mRNA have been taken as important indexes extensively applied in the basic study of cerebral ischemia by some scholars abroad. CONCLUSION： HSP70 plays a protective role in cerebral ischemia, and a deeper research into the biological function of HSP70 will provide a new way for the therapy of cerebral ischemia.
文摘In 2010, No.1 document of central government demanded strengthening mediation and settlement of ownership of rural collective land, to complete confirmation of right and registration and issue of certificate of rural collective land in 3 years. However, the mediation and settlement of land ownership in China still remain at starting stage, and there are many problems in both theory and practice. In this situation, this paper summarizes current situations of disputes about ownership of collective land in Beijing, analyzes causes of disputes, introduces existing working mechanism, methods and problems of dispute mediation and settlement, and finally presents feasible recommendations, in the hope of providing guidance for mediation and settlement of land ownership disputes.
基金Supported by National Key Research and Development Program of China (2016YFD0200900)China Agriculture Research System of MOF and MARA (CARS-19).
文摘[Objectives] The paper was to explore the control effects of different botanical pesticides against Empoasca pirisuga Matumura. [Methods] 5% Eucalyptol SL, 0.5% matrine SL and 50% thiacloprid WDG were used to control E. pirisuga , and the decline rate of insect population was investigated. [Results] Eucalyptol had good control effect on E. pirisuga , with slow effect but long duration. It was harmless to natural enemies in tea gardens, with high safety and no chemical injury. [Conclusions] The study provides a theoretical basis for the application of botanical pesticides in tea production.
基金Supported by National Key R&D Program of China(2016YFD0200900)China Agriculture Research System of MOF and MARA(CARS-19).
文摘[Objectives]This study was conducted to explore the application effects of Sinochem microbial organic fertilizer on tea plants.[Methods]Through the experiment and demonstration of Sinochem microbial organic fertilizer,its effects on the yield and quality of tea and the physical and chemical quality of soil were explored.[Results]Compared with the conventional organic fertilizer cake fertilizer,the fertilizer could increase the weight of freshly picked bud leaves,increase the yield of tea,and thus promote the growth of tea plants.It increased the contents of chlorophyll components,amino acids and tea polyphenols,the main functional substances of tea,which was conducive to improving the internal quality of tea.It improved the physical and chemical properties of soil,and increased the contents of organic matter,alkali-hydrolyzable nitrogen and available phosphorus in tea garden soil.It also had a good effect in improving soil environmental health indexes and physical and chemical properties,and did not contain heavy metals and plant growth hormones.[Conclusions]This study provides a theoretical basis for the popularization and application of Sinochem microbial organic fertilizer.
文摘Noble metal Ag nanoparticles with unique surface plasmon resonance property have attracted much attention recently in the field of photocatalysis. Based on the advantages of Ag nanoparticles and semiconductor CeO2, a novel plasmonic photocatalyst Ag-AgCl/CeO2 was prepared with a facile route. The as-prepared samples were characterized using scanning and transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffusion re?ection spectroscopy. This metal-semiconductor nanocomposite plasmonic photocatalyst exhibited a high visible-light photocatalytic activity and good stability for photocatalytic degradation of methyl orange in water. Ag-AgCl/CeO2 will be a potentially promising plasmonic photocatalysts for organic pollutant degradation and water purification.
基金supported by the Major Project of Tobacco Biological Effects(552022AK0070,110202102014)。
文摘Nicotine is widely recognized as the primary contributor to tobacco dependence.Previous studies have indicated that molecular and behavioral responses to nicotine are primarily mediated by ventral tegmental area(VTA)neurons,and accumulating evidence suggests that glia play prominent roles in nicotine addiction.However,VTA neurons and glia have yet to be characterized at the transcriptional level during the progression of nicotine self-administration.Here,a male mouse model of nicotine self-administration is established and the timing of three critical phases(pre-addiction,addicting,and post-addiction phase)is characterized.Single-nucleus RNA sequencing in the VTA at each phase is performed to comprehensively classify specific cell subtypes.Adaptive changes occurred during the addicting and post-addiction phases,with the addicting phase displaying highly dynamic neuroplasticity that profoundly impacts the transcription in each cell subtype.Furthermore,significant transcriptional changes in energy metabolism-related genes are observed,accompanied by notable structural alterations in neuronal mitochondria during the progression of nicotine self-administration.The results provide insights into mechanisms underlying the progression of nicotine addiction,serving as an important resource for identifying potential molecular targets for nicotine cessation.
