With the prevalence of obesity and obesity-related metabolic syndrome,such as insulin resistance in recent years,it is urgent to explore effective interventions to prevent the progression of obesity-related metabolic ...With the prevalence of obesity and obesity-related metabolic syndrome,such as insulin resistance in recent years,it is urgent to explore effective interventions to prevent the progression of obesity-related metabolic syndrome.Palmitoleic acid is a monounsaturated fatty acid that is available from dietary sources,mainly derived from marine products.P almitoleic acid plays a positive role in maintaining glucose homeostasis and reducing inflammation.However,it is still unknow the mechanism of palmitoleic acid in ameliorating insulin resistance.Here,we investigated the effects of palmitoleic acid on chow diet(CD)-fed and high-fat diet(HFD)-fed mice,which were fed CD or HFD for 12 weeks before administration.We administrated mice with BSA(control),oleic acid,or palmitoleic acid for 6 weeks on top of CD or HFD feeding.We found that palmitoleic acid only improved glucose homeostasis in HFD-fed obese mice by increasing glucose clearance and reducing HOMA-IR.Further study explored that palmitoleic acid changed the composition of gut microbiota by decreasing Firmicutes population and increasing Bacteroidetes population.In colon,palmitoleic acid increased intestinal tight junction integrity and reduced inflammation.Moreover,palmitoleic acid decreased macrophage infiltration in liver and adipose tissue and increase glucose uptake in adipose tissue.Diacylglycerol(DAG)in tissue(for example,liver)is found to positively correlated with HOMA-IR.HFD enhanced the levels of DAGs in liver but not in adipose tissue in this study.Palmitoleic acid did not reverse the high DAG levels induced by HFD in liver.Therefore,in HFD-fed mice,palmitoleic acid reduced insulin resistance by an independent-manner of DAGs.It might be associated with the beneficial effects of palmitoleic acid on altering the gut microbiota composition,improving of intestinal barrier function,and downregulating the inflammation in colon,liver,and adipose tissue.展开更多
The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents ...The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents in hippocampal neurons. These tonic currents can be enhanced by low-dose isoflurane, which is associated with learning and memory impairment. Inverse agonists of α5 GABAARs, such as L-655,708, are able to reverse the short-term memory deficit caused by low-dose isoflurane in young animals. However, whether these negative allosteric modulators have the same effects on aged rats remains unclear. In the present study, we mainly investigated the effects of L-655,708 on low-dose(1.3%) isoflurane-induced learning and memory impairment in elderly rats. Young(3-month-old) and aged(24-month-old) Wistar rats were randomly assigned to receive L-655,708 0.5 hour before or 23.5 hours after 1.3% isoflurane anesthesia.The Morris Water Maze tests demonstrated that L-655,708 injected before or after anesthesia could reverse the memory deficit in young rats. But in aged rats, application of L-655,708 only before anesthesia showed similar effects. Reverse transcription-polymerase chain reaction showed that low-dose isoflurane decreased the mRNA expression of α5 GABAARs in aging hippocampal neurons but increased that in young animals. These findings indicate that L-655,708 prevented but could not reverse 1.3% isoflurane-induced spatial learning and memory impairment in aged Wistar rats. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Academy of Military Medical Science of China(approval No. NBCDSER-IACUC-2015128) in December 2015.展开更多
ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen...ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen reduction/evolution reactions,ORR/OER).It has been well understood in our recent work that the secondary metal dopant at B-site(e.g.,Mn in LaMn_(x)Co_(1-x)O_(3))can regulate the electronic structure and improve the ORR/OER activity.In this work,the Mn-Ni pairs are employed as the dual dopant in LaMn_(x)Ni_(y)Co_(z)O_(3)(x+y+z=1)catalysts toward bifunctional ORR and OER.The structure-property relationships between the triple metal B-site(Mn,Ni and Co)and the electrochemical performance are particularly investigated.Compared to the individual Mn doping(e.g.,LaMnCoO3(Mn:Co=1:3)catalyst),the dual Mn-Ni doping significantly improves the ORR mass activity@0.8 V by 1.54 times;meanwhile,the OER overpotential@10 mA cm^(-2) is reduced from 420 to 370 mV,and the OER current density at 1.55 V is increased by 2.43 times.Reasonably,the potential gap between EDRR@-1 mA cm^(-2) and EDER@10 mA cm^(-2) is achieved as only 0.76 V by using the optimal LaMn_(x)Ni_(y)Co_(z)O_(3)(x:y:z=1:2:3)catalyst.It is revealed that the dual Mn-Ni dopant efficiently optimizes electron structures of the LaMnNiCoO_(3)(1:2:3)catalyst,which not only decreases the e_(g) orbital electron number,but also modulates the O 2 p-band closer to the Femi level,accounting for the enhanced bifunctional activity.展开更多
Oxygen reduction reaction(ORR)is an important electrochemical process for renewable energy conversion and storage applications such as fuel cells and metal-air batteries.ORR is sluggish in kinetics and requires a larg...Oxygen reduction reaction(ORR)is an important electrochemical process for renewable energy conversion and storage applications such as fuel cells and metal-air batteries.ORR is sluggish in kinetics and requires a large amount of platinum group metal(PGM)-based catalysts to facilitate its slow reaction rate.Application of precious metals raises the cost and decreases the competitivity of these devices in the market.To address this challenge,PGM-free ORR catalysts have been intensively investigated as an alternative to replace the PGM-based catalysts and to promote the deployment of ORR-related applications.In particular,the biomass holds promising potential to be used as the precursor material for PGM-free ORR catalysts.This pathway has gained more and more attention in recent years.In this review,recent advances regarding biomass-derived ORR catalysts are summarized with a focus on the rational design of both active sites and porous structures which are the two key factors in determining ORR performance of catalysts.At the end,the perspectives of development of biomass-derived catalysts is discussed.展开更多
A new approach to knowledge acquisition in incomplete information system with fuzzy decisions is proposed. In such incomplete information system, the universe of discourse is classified by the maximal tolerance classe...A new approach to knowledge acquisition in incomplete information system with fuzzy decisions is proposed. In such incomplete information system, the universe of discourse is classified by the maximal tolerance classes, and fuzzy approximations are defined based on them. Three types of relative reducts of maximal tolerance classes are then proposed, and three types of fuzzy decision rules based on the proposed attribute description are defined. The judgment theorems and approximation discernibility functions with respect to them are presented to compute the relative reduct by using Boolean reasoning techniques, from which we can derive optimal fuzzy decision rules from the systems. At last, three types of relative reducts of the system and their computing methods are given.展开更多
Polymeric materials with excellent performance are the foundation for developing high-level technology and advanced manufacturing.Polymeric material genome engineering(PMGE)is becoming a vital platform for the intelli...Polymeric materials with excellent performance are the foundation for developing high-level technology and advanced manufacturing.Polymeric material genome engineering(PMGE)is becoming a vital platform for the intelligent manufacturing of polymeric materials.However,the development of PMGE is still in its infancy,and many issues remain to be addressed.In this perspective,we elaborate on the PMGE concepts,summarize the state-of-the-art research and achievements,and highlight the challenges and prospects in this field.In particular,we focus on property estimation approaches,including property proxy prediction and machine learning prediction of polymer properties.The potential engineering applications of PMGE are discussed,including the fields of advanced composites,polymeric materials for communications,and integrated circuits.展开更多
Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configura...Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.展开更多
The development of renewable and affordable energy is crucial for building a sustainable society. In this context, establishing a sustainable infrastructure for renewable energy requires the integration of energy stor...The development of renewable and affordable energy is crucial for building a sustainable society. In this context, establishing a sustainable infrastructure for renewable energy requires the integration of energy storage, specifically use of renewable hydrogen. The hydrogen evolution reaction (HER) of electrochemical water splitting is a promising method for producing green hydrogen. Recently, two-dimensional nanomaterials have shown great promise in promoting the HER in terms of both fundamental research and practical applications due to their high specific surface areas and tunable electronic properties. Among them, molybdenum disulfide (MoS2), a non-noble metal catalyst, has emerged as a promising alternative to replace expensive platinum-based catalysts for the HER because MoS_(2)has a high inherent activity, low cost, and abundant reserves. At present, greatly improved activity and stability are urgently needed for MoS_(2)to enable wide deployment of water electrolysis devices. In this regard, efficient strategies for precisely modifying MoS_(2)are of interest. Herein, the progress made with MoS_(2)as an HER catalyst is reviewed, with a focus on modification strategies, including phase engineering, morphology design, defect engineering, heteroatom doping, and heterostructure construction. It is believed that these strategies will be helpful in designing and developing high-performance and low-cost MoS2-based catalysts by lowering the charge transfer barrier, increasing the active site density, and optimizing the surface hydrophilicity. In addition, the challenges of MoS_(2)electrocatalysts and perspectives for future research and development of these catalysts are discussed.展开更多
The growth of multi-mode Richtmyer-Meshkov instability under multiple impingements and the effect of initial shock strength on the growth of RMI are numerically investigated. We obtain the time evolution of turbulent ...The growth of multi-mode Richtmyer-Meshkov instability under multiple impingements and the effect of initial shock strength on the growth of RMI are numerically investigated. We obtain the time evolution of turbulent mixing zone width for initial shock with different strength. The results show that the turbulent mixing zone width grows in a different manner at different stage but strictly in a similar way for the initial shock with different strength. Also, the initial shock strength has a significant effect on the growth rate of turbulent mixing zone width, especially before reshock, but can not change the growth laws in the whole process.展开更多
We sought to investigate the correlation between the -455G/A and -148C/T polymorphisms of the β-fibrinogen gene and plasma fibrinogen levels in patients with cerebral infarction and in healthy subjects among the Xinj...We sought to investigate the correlation between the -455G/A and -148C/T polymorphisms of the β-fibrinogen gene and plasma fibrinogen levels in patients with cerebral infarction and in healthy subjects among the Xinjiang Uygur and Han Chinese populations, by using polymerase chain reaction-restriction enzyme digestion analysis. Results showed that there were no statistically significant differences in the distributions of the -455G/A genotype and allele frequency between the Uygurs and the Han. Plasma fibrinogen levels in cerebral infarction patients among the Uygurs and the Han were higher than those among healthy subjects. In particular, the frequencies of the -455G/A AA and -148C/T TT genotypes were significantly higher than in healthy subjects. Individuals carrying the A or T allele had a higher incidence of cerebral infarction compared with those carrying the G or C allele. Our experimental findings indicate that the -148C/T and -455G/A polymorphisms are associated with cerebral infarction in Xinjiang Uygur and Han Chinese subjects. The susceptibility- conferring alleles are -148T and -455A, and the susceptibility-conferring genotype is -455G/A + AA.展开更多
AIM: To investigate the disruptions of interstitial cells of Cajal (ICC) in the remaining bowel in rats after massive small bowel resection (mSBR). METHODS: Thirty male Sprague-Dawley rats fitting entry criteria were ...AIM: To investigate the disruptions of interstitial cells of Cajal (ICC) in the remaining bowel in rats after massive small bowel resection (mSBR). METHODS: Thirty male Sprague-Dawley rats fitting entry criteria were divided randomly into three experimental groups (n = 10 each): Group A rats underwent bowel transection and re-anastomosis (sham) and tissue samples were harvested at day 7 post-surgery. Group B and C rats underwent 80% small bowel resection with tissue harvested from Group B rats at day 7 post-surgery, and from Group C rats at day 14 postsurgery. The distribution of ICC at the site of the resid-ual small bowel was evaluated by immunohistochemical analysis of small intestine samples. The ultrastructural changes of ICC in the remnant ileum of model rats 7 and 14 d after mSBR were analyzed by transmission electron microscopy. Intracellular recordings of slow wave oscillations were used to evaluate electrical pacemaking. The protein expression of c-kit, ICC phenotypic markers, and membrane-bound stem cell factor (mSCF) in intestinal smooth muscle of each group were detected by Western blotting. RESULTS: After mSBR, immunohistochemical analysis indicated that the number of c-kit-positive cells was dramatically decreased in Group B rats compared with sham tissues. Significant ultrastructural changes in ICC with associated smooth muscle hypertrophy were also observed. Disordered spontaneous rhythmic contractions with reduced amplitude (8.5 ± 1.4 mV vs 24.8 ± 1.3 mV, P = 0.037) and increased slow wave frequency (39.5 ± 2.1 cycles/min vs 33.0 ± 1.3 cycles/min, P = 0.044) were found in the residual intestinal smooth muscle 7 d post mSBR. The contractile function and electrical activity of intestinal circular smooth muscle returned to normal levels at 14 d post mSBR (amplitude, 14.9 ± 1.6 mV vs 24.8 ± 1.3 mV; frequency, 30.7 ± 1.7 cycles/min vs 33.0 ± 1.3 cycles/min). The expression of Mscf and c-kit protein was decreased at 7 d (P = 0.026), but gradually returned to normal levels at 14 d. The ICC and associated neural networks were disrupted, which was associated with the phenotype alterations of ICC. CONCLUSION: Massive small bowel resection in rats triggered damage to ICC networks and decreased the number of ICC leading to disordered intestinal rhythmicity. The mSCF/c-kit signaling pathway plays a role in the regulation and maintenance of ICC phenotypes.展开更多
Objective: To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation (CSI) using helical tomotherapy (HT) system in our center. Methods: Twenty-three p...Objective: To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation (CSI) using helical tomotherapy (HT) system in our center. Methods: Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. M1 of the patients' CSI used the HT system. The total doses were 27-36 Gy/15-20 F (1.5-2 Gy per fraction), and total local doses were 46-60 Gy/30-50 F (5 fractions per week). M1 female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months (range, 5-67 months). The SPSS19.0 software was used, and the overall survival (OS) was calculated using the Kaplan-Meier method. Results: Among 17 patients with assessable tumors, 9 cases (52.9%) were CR, 7 cases (41.2%) were PR, and 1 case (5.9%) was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively. Conclusions: For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk (ORA) and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.展开更多
Objective: To analyze the invention effect of curcumin on chronic urinary tract infection in rats and explore its possible mechanism of action. Methods: The experimental animals were randomly divided into three groups...Objective: To analyze the invention effect of curcumin on chronic urinary tract infection in rats and explore its possible mechanism of action. Methods: The experimental animals were randomly divided into three groups, normal, model and curcumin group. Chronic urinary tract infection models were built for model group and curcumin group by injecting coliform fluid into the cavity of bladder. From the first day of modeling, rats in the curcumin group were injected with 150 mg/kg curcumin, while rats in normal group and model group were given no other treatment. The treatment lasted for 14 d. The white blood cell counts in blood and urine, bacterial colony count in urine and renal tubular functional indexes of rats in all groups at day 1, 7, and 14 after treatment were detected. Urine 毬2-microglobulin(毬2-MG), urinary N-acetyl-毬-D glucosaminidase(NAG) levels were used to detected the inflammatory cytokines in serum after treatment including the contents of IL-6, IL-8, IL-10 and monocyte chemoattractant protein-1(MCP-1), and real-time PCR was employed to determine the expression of m RNA of toll-like receptor 2(TLR-2) and TLR-4 in renal tissues and bladder tissues of all groups after treatment. Results: The white blood cell counts at day 1 and 7 after treatment in rats of model group and curcumin group were significantly higher than those of normal group at the same time points, while the white blood cell counts of the curcumin group were significantly lower than those of model group(P < 0.05). The urine white blood cell counts in rats of model group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points; those in the curcumin group were significantly lower than those of the model group at day 1, 7 and 14 at the same time points(P < 0.05). The bacterial colony counts of urine in rats of model group and curcumin group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points, while the counts of curcumin group were significantly lower than those of model group at the same time points(P < 0.05). Levels of urine 毬2-MG, NAG, IL-6, IL-8, IL-10, MCP-1 and expression of TLR2 m RNA and TLR4 m RNA in renal and bladder tissues in rats of model group were significantly higher than those of the normal group, while these variables of the cercumin group were significantly higher than those of the normal group but lower than those of model group(P < 0.05). Conclusions: Curcumin can significantly improve the symptoms of chronic urinary tract infections, protect renal tubular function, and also decline inflammatory responses by influencing the expressions of TLR2 m RNA and TLR4 m RNA so as to exert its curative effect on chronic urinary tract infections.展开更多
A 39-year-old male reported fevers,weight loss,watery loose stools,and decreased visual acuity in his right eye over the prior five years.He was pancytopenic,had an elevated American council on exercise level,total bi...A 39-year-old male reported fevers,weight loss,watery loose stools,and decreased visual acuity in his right eye over the prior five years.He was pancytopenic,had an elevated American council on exercise level,total bilirubin,and alkaline phosphatase.Computed tomography revealed massive hepatosplenomegaly and emphysematous lung changes.Liver biopsy showed non caseating granulomas.The patient was diagnosed with extrapulmonary sarcoidosis and was treated with prednisone.The patient symptomatically improved but 5 mo later presented with abdominal pain caused by perforation of the cecum.He underwent a cecectomy and pathology revealed pneumatosis cystoides intestinalis.This represents the first reported association between pneumatosis cystoides intestinalis and sarcoidosis.The etiology of pneumatosis cystoides intestinalis in this case was likely multifactorial and involved both effects of the corticosteroids as well as the advanced nature of the gastrointestinal sarcoidosis.Furthermore this case has the unique features of emphysematous lung changes and pancytopenia which are uncommon with sarcoidosis.展开更多
Poly[(methylsilylene ethynylene phenylene ethynylene)-co-(tetramethyldisiloxane ethynylene phenylene ethynylene)]was synthesized by polycondensation reaction of m-diethynylbenzene magnesium reagent with 1,3-dichlorote...Poly[(methylsilylene ethynylene phenylene ethynylene)-co-(tetramethyldisiloxane ethynylene phenylene ethynylene)]was synthesized by polycondensation reaction of m-diethynylbenzene magnesium reagent with 1,3-dichlorotetramethyldisiloxane and dichloromethylsilane.The copolymer was characterized by FT-IR,~1H NMR,differential scanning calorimetry and thermogravimetric analysis.The results show that the copolymer exhibits good processability and cures at low temperatures.The cured copolymer shows high thermal stability.展开更多
基金by National Natural Science Foundation of China(81803224)Young Scholars Program of Shandong University(2018WLJH33)to X.G.+3 种基金National Natural Science Foundation of China(81973031)Cheeloo Young Scholar Program of Shandong University(21320089963054)to H.W.Young Scholars Program of Shandong University(2018WLJH34)the Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology(LMDBKF-2019-05)to L.D.
文摘With the prevalence of obesity and obesity-related metabolic syndrome,such as insulin resistance in recent years,it is urgent to explore effective interventions to prevent the progression of obesity-related metabolic syndrome.Palmitoleic acid is a monounsaturated fatty acid that is available from dietary sources,mainly derived from marine products.P almitoleic acid plays a positive role in maintaining glucose homeostasis and reducing inflammation.However,it is still unknow the mechanism of palmitoleic acid in ameliorating insulin resistance.Here,we investigated the effects of palmitoleic acid on chow diet(CD)-fed and high-fat diet(HFD)-fed mice,which were fed CD or HFD for 12 weeks before administration.We administrated mice with BSA(control),oleic acid,or palmitoleic acid for 6 weeks on top of CD or HFD feeding.We found that palmitoleic acid only improved glucose homeostasis in HFD-fed obese mice by increasing glucose clearance and reducing HOMA-IR.Further study explored that palmitoleic acid changed the composition of gut microbiota by decreasing Firmicutes population and increasing Bacteroidetes population.In colon,palmitoleic acid increased intestinal tight junction integrity and reduced inflammation.Moreover,palmitoleic acid decreased macrophage infiltration in liver and adipose tissue and increase glucose uptake in adipose tissue.Diacylglycerol(DAG)in tissue(for example,liver)is found to positively correlated with HOMA-IR.HFD enhanced the levels of DAGs in liver but not in adipose tissue in this study.Palmitoleic acid did not reverse the high DAG levels induced by HFD in liver.Therefore,in HFD-fed mice,palmitoleic acid reduced insulin resistance by an independent-manner of DAGs.It might be associated with the beneficial effects of palmitoleic acid on altering the gut microbiota composition,improving of intestinal barrier function,and downregulating the inflammation in colon,liver,and adipose tissue.
文摘The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents in hippocampal neurons. These tonic currents can be enhanced by low-dose isoflurane, which is associated with learning and memory impairment. Inverse agonists of α5 GABAARs, such as L-655,708, are able to reverse the short-term memory deficit caused by low-dose isoflurane in young animals. However, whether these negative allosteric modulators have the same effects on aged rats remains unclear. In the present study, we mainly investigated the effects of L-655,708 on low-dose(1.3%) isoflurane-induced learning and memory impairment in elderly rats. Young(3-month-old) and aged(24-month-old) Wistar rats were randomly assigned to receive L-655,708 0.5 hour before or 23.5 hours after 1.3% isoflurane anesthesia.The Morris Water Maze tests demonstrated that L-655,708 injected before or after anesthesia could reverse the memory deficit in young rats. But in aged rats, application of L-655,708 only before anesthesia showed similar effects. Reverse transcription-polymerase chain reaction showed that low-dose isoflurane decreased the mRNA expression of α5 GABAARs in aging hippocampal neurons but increased that in young animals. These findings indicate that L-655,708 prevented but could not reverse 1.3% isoflurane-induced spatial learning and memory impairment in aged Wistar rats. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Academy of Military Medical Science of China(approval No. NBCDSER-IACUC-2015128) in December 2015.
基金supported by the National Natural Science Foundation of China(Grant Nos.21433003,21805064 and 21773049)National Key Research and Development Program of China(Program No.2016YFB0101207)。
文摘ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen reduction/evolution reactions,ORR/OER).It has been well understood in our recent work that the secondary metal dopant at B-site(e.g.,Mn in LaMn_(x)Co_(1-x)O_(3))can regulate the electronic structure and improve the ORR/OER activity.In this work,the Mn-Ni pairs are employed as the dual dopant in LaMn_(x)Ni_(y)Co_(z)O_(3)(x+y+z=1)catalysts toward bifunctional ORR and OER.The structure-property relationships between the triple metal B-site(Mn,Ni and Co)and the electrochemical performance are particularly investigated.Compared to the individual Mn doping(e.g.,LaMnCoO3(Mn:Co=1:3)catalyst),the dual Mn-Ni doping significantly improves the ORR mass activity@0.8 V by 1.54 times;meanwhile,the OER overpotential@10 mA cm^(-2) is reduced from 420 to 370 mV,and the OER current density at 1.55 V is increased by 2.43 times.Reasonably,the potential gap between EDRR@-1 mA cm^(-2) and EDER@10 mA cm^(-2) is achieved as only 0.76 V by using the optimal LaMn_(x)Ni_(y)Co_(z)O_(3)(x:y:z=1:2:3)catalyst.It is revealed that the dual Mn-Ni dopant efficiently optimizes electron structures of the LaMnNiCoO_(3)(1:2:3)catalyst,which not only decreases the e_(g) orbital electron number,but also modulates the O 2 p-band closer to the Femi level,accounting for the enhanced bifunctional activity.
基金This study is financially supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)the Fonds de Recherche du Québec—Nature et Technologies(FRQNT),Centre Québécois sur les Materiaux Fonctionnels(CQMF)+3 种基金Institut National de la Recherche Scientifique(INRS)National Natural Science Foundation of China(Grant No.21805064)SS acknowledges the ECS-Toyota Young Investigator Fellowship.LD acknowledges the scholarship under the International Postdoctoral Exchange Fellowship Program by the Office of China Postdoctoral Council(Grant No.20180072)FRQNT for the Postdoctoral scholarship(V2,file number:274384)in Quebec Canada.
文摘Oxygen reduction reaction(ORR)is an important electrochemical process for renewable energy conversion and storage applications such as fuel cells and metal-air batteries.ORR is sluggish in kinetics and requires a large amount of platinum group metal(PGM)-based catalysts to facilitate its slow reaction rate.Application of precious metals raises the cost and decreases the competitivity of these devices in the market.To address this challenge,PGM-free ORR catalysts have been intensively investigated as an alternative to replace the PGM-based catalysts and to promote the deployment of ORR-related applications.In particular,the biomass holds promising potential to be used as the precursor material for PGM-free ORR catalysts.This pathway has gained more and more attention in recent years.In this review,recent advances regarding biomass-derived ORR catalysts are summarized with a focus on the rational design of both active sites and porous structures which are the two key factors in determining ORR performance of catalysts.At the end,the perspectives of development of biomass-derived catalysts is discussed.
基金supported by the National Natural Science Foundation of China (61070241)the Natural Science Foundation of Shandong Province (ZR2010FM035)Science Research Foundation of University of Jinan (XKY0808)
文摘A new approach to knowledge acquisition in incomplete information system with fuzzy decisions is proposed. In such incomplete information system, the universe of discourse is classified by the maximal tolerance classes, and fuzzy approximations are defined based on them. Three types of relative reducts of maximal tolerance classes are then proposed, and three types of fuzzy decision rules based on the proposed attribute description are defined. The judgment theorems and approximation discernibility functions with respect to them are presented to compute the relative reduct by using Boolean reasoning techniques, from which we can derive optimal fuzzy decision rules from the systems. At last, three types of relative reducts of the system and their computing methods are given.
基金supported by the National Natural Science Foundation of China(22103025,51833003,22173030,21975073,and 51621002).
文摘Polymeric materials with excellent performance are the foundation for developing high-level technology and advanced manufacturing.Polymeric material genome engineering(PMGE)is becoming a vital platform for the intelligent manufacturing of polymeric materials.However,the development of PMGE is still in its infancy,and many issues remain to be addressed.In this perspective,we elaborate on the PMGE concepts,summarize the state-of-the-art research and achievements,and highlight the challenges and prospects in this field.In particular,we focus on property estimation approaches,including property proxy prediction and machine learning prediction of polymer properties.The potential engineering applications of PMGE are discussed,including the fields of advanced composites,polymeric materials for communications,and integrated circuits.
基金funded by the National Natural Science Foundation of China (22208331, 52003300)the Natural Sciences and Engineering Research Council of Canada (NSERC)+4 种基金the Fonds de Recherche du Québec-Nature et Technologies (FRQNT)Centre Québécois sur les Materiaux Fonctionnels (CQMF), McGill Universityécole de Technologie Supérieure (éTS)Institut National de la Recherche Scientifique (INRS)the support from the Marcelle-Gauvreau Engineering Research Chair program
文摘Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.
基金the Outstanding Youth Project of Guangdong Provincial Natural Science Foundation,China(Grant No.2022B1515020020)the National Natural Science Foundation of China(Grant No.2225071013)+2 种基金the Guangdong Basic and Applied Basic Research Foundation,China(No.2022B1515120079)the Funding by Science and Technology Projects in Guangzhou,China(No.202206050003)the Guangdong Engineering Technology Research Center for Hydrogen Energy and Fuel Cells,China.
文摘The development of renewable and affordable energy is crucial for building a sustainable society. In this context, establishing a sustainable infrastructure for renewable energy requires the integration of energy storage, specifically use of renewable hydrogen. The hydrogen evolution reaction (HER) of electrochemical water splitting is a promising method for producing green hydrogen. Recently, two-dimensional nanomaterials have shown great promise in promoting the HER in terms of both fundamental research and practical applications due to their high specific surface areas and tunable electronic properties. Among them, molybdenum disulfide (MoS2), a non-noble metal catalyst, has emerged as a promising alternative to replace expensive platinum-based catalysts for the HER because MoS_(2)has a high inherent activity, low cost, and abundant reserves. At present, greatly improved activity and stability are urgently needed for MoS_(2)to enable wide deployment of water electrolysis devices. In this regard, efficient strategies for precisely modifying MoS_(2)are of interest. Herein, the progress made with MoS_(2)as an HER catalyst is reviewed, with a focus on modification strategies, including phase engineering, morphology design, defect engineering, heteroatom doping, and heterostructure construction. It is believed that these strategies will be helpful in designing and developing high-performance and low-cost MoS2-based catalysts by lowering the charge transfer barrier, increasing the active site density, and optimizing the surface hydrophilicity. In addition, the challenges of MoS_(2)electrocatalysts and perspectives for future research and development of these catalysts are discussed.
文摘The growth of multi-mode Richtmyer-Meshkov instability under multiple impingements and the effect of initial shock strength on the growth of RMI are numerically investigated. We obtain the time evolution of turbulent mixing zone width for initial shock with different strength. The results show that the turbulent mixing zone width grows in a different manner at different stage but strictly in a similar way for the initial shock with different strength. Also, the initial shock strength has a significant effect on the growth rate of turbulent mixing zone width, especially before reshock, but can not change the growth laws in the whole process.
基金supported by the National Natural Science Foundation of China, No. 81060097
文摘We sought to investigate the correlation between the -455G/A and -148C/T polymorphisms of the β-fibrinogen gene and plasma fibrinogen levels in patients with cerebral infarction and in healthy subjects among the Xinjiang Uygur and Han Chinese populations, by using polymerase chain reaction-restriction enzyme digestion analysis. Results showed that there were no statistically significant differences in the distributions of the -455G/A genotype and allele frequency between the Uygurs and the Han. Plasma fibrinogen levels in cerebral infarction patients among the Uygurs and the Han were higher than those among healthy subjects. In particular, the frequencies of the -455G/A AA and -148C/T TT genotypes were significantly higher than in healthy subjects. Individuals carrying the A or T allele had a higher incidence of cerebral infarction compared with those carrying the G or C allele. Our experimental findings indicate that the -148C/T and -455G/A polymorphisms are associated with cerebral infarction in Xinjiang Uygur and Han Chinese subjects. The susceptibility- conferring alleles are -148T and -455A, and the susceptibility-conferring genotype is -455G/A + AA.
基金Supported by Grants from the Program for Innovative Research Team of Shanghai Municipal Education Commission and Special Foundation of Shanghai Municipal Public Health Bureau, LJ06021the National Natural Science Foundation of China, No. 30772270, 30972427the Scientific Foundation of Nantong University, No. 10Z046
文摘AIM: To investigate the disruptions of interstitial cells of Cajal (ICC) in the remaining bowel in rats after massive small bowel resection (mSBR). METHODS: Thirty male Sprague-Dawley rats fitting entry criteria were divided randomly into three experimental groups (n = 10 each): Group A rats underwent bowel transection and re-anastomosis (sham) and tissue samples were harvested at day 7 post-surgery. Group B and C rats underwent 80% small bowel resection with tissue harvested from Group B rats at day 7 post-surgery, and from Group C rats at day 14 postsurgery. The distribution of ICC at the site of the resid-ual small bowel was evaluated by immunohistochemical analysis of small intestine samples. The ultrastructural changes of ICC in the remnant ileum of model rats 7 and 14 d after mSBR were analyzed by transmission electron microscopy. Intracellular recordings of slow wave oscillations were used to evaluate electrical pacemaking. The protein expression of c-kit, ICC phenotypic markers, and membrane-bound stem cell factor (mSCF) in intestinal smooth muscle of each group were detected by Western blotting. RESULTS: After mSBR, immunohistochemical analysis indicated that the number of c-kit-positive cells was dramatically decreased in Group B rats compared with sham tissues. Significant ultrastructural changes in ICC with associated smooth muscle hypertrophy were also observed. Disordered spontaneous rhythmic contractions with reduced amplitude (8.5 ± 1.4 mV vs 24.8 ± 1.3 mV, P = 0.037) and increased slow wave frequency (39.5 ± 2.1 cycles/min vs 33.0 ± 1.3 cycles/min, P = 0.044) were found in the residual intestinal smooth muscle 7 d post mSBR. The contractile function and electrical activity of intestinal circular smooth muscle returned to normal levels at 14 d post mSBR (amplitude, 14.9 ± 1.6 mV vs 24.8 ± 1.3 mV; frequency, 30.7 ± 1.7 cycles/min vs 33.0 ± 1.3 cycles/min). The expression of Mscf and c-kit protein was decreased at 7 d (P = 0.026), but gradually returned to normal levels at 14 d. The ICC and associated neural networks were disrupted, which was associated with the phenotype alterations of ICC. CONCLUSION: Massive small bowel resection in rats triggered damage to ICC networks and decreased the number of ICC leading to disordered intestinal rhythmicity. The mSCF/c-kit signaling pathway plays a role in the regulation and maintenance of ICC phenotypes.
文摘Objective: To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation (CSI) using helical tomotherapy (HT) system in our center. Methods: Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. M1 of the patients' CSI used the HT system. The total doses were 27-36 Gy/15-20 F (1.5-2 Gy per fraction), and total local doses were 46-60 Gy/30-50 F (5 fractions per week). M1 female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months (range, 5-67 months). The SPSS19.0 software was used, and the overall survival (OS) was calculated using the Kaplan-Meier method. Results: Among 17 patients with assessable tumors, 9 cases (52.9%) were CR, 7 cases (41.2%) were PR, and 1 case (5.9%) was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively. Conclusions: For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk (ORA) and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.
基金supported by Scientific and Technological Research and Development Plan in Hebei Province(Grant No.10276154)
文摘Objective: To analyze the invention effect of curcumin on chronic urinary tract infection in rats and explore its possible mechanism of action. Methods: The experimental animals were randomly divided into three groups, normal, model and curcumin group. Chronic urinary tract infection models were built for model group and curcumin group by injecting coliform fluid into the cavity of bladder. From the first day of modeling, rats in the curcumin group were injected with 150 mg/kg curcumin, while rats in normal group and model group were given no other treatment. The treatment lasted for 14 d. The white blood cell counts in blood and urine, bacterial colony count in urine and renal tubular functional indexes of rats in all groups at day 1, 7, and 14 after treatment were detected. Urine 毬2-microglobulin(毬2-MG), urinary N-acetyl-毬-D glucosaminidase(NAG) levels were used to detected the inflammatory cytokines in serum after treatment including the contents of IL-6, IL-8, IL-10 and monocyte chemoattractant protein-1(MCP-1), and real-time PCR was employed to determine the expression of m RNA of toll-like receptor 2(TLR-2) and TLR-4 in renal tissues and bladder tissues of all groups after treatment. Results: The white blood cell counts at day 1 and 7 after treatment in rats of model group and curcumin group were significantly higher than those of normal group at the same time points, while the white blood cell counts of the curcumin group were significantly lower than those of model group(P < 0.05). The urine white blood cell counts in rats of model group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points; those in the curcumin group were significantly lower than those of the model group at day 1, 7 and 14 at the same time points(P < 0.05). The bacterial colony counts of urine in rats of model group and curcumin group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points, while the counts of curcumin group were significantly lower than those of model group at the same time points(P < 0.05). Levels of urine 毬2-MG, NAG, IL-6, IL-8, IL-10, MCP-1 and expression of TLR2 m RNA and TLR4 m RNA in renal and bladder tissues in rats of model group were significantly higher than those of the normal group, while these variables of the cercumin group were significantly higher than those of the normal group but lower than those of model group(P < 0.05). Conclusions: Curcumin can significantly improve the symptoms of chronic urinary tract infections, protect renal tubular function, and also decline inflammatory responses by influencing the expressions of TLR2 m RNA and TLR4 m RNA so as to exert its curative effect on chronic urinary tract infections.
文摘A 39-year-old male reported fevers,weight loss,watery loose stools,and decreased visual acuity in his right eye over the prior five years.He was pancytopenic,had an elevated American council on exercise level,total bilirubin,and alkaline phosphatase.Computed tomography revealed massive hepatosplenomegaly and emphysematous lung changes.Liver biopsy showed non caseating granulomas.The patient was diagnosed with extrapulmonary sarcoidosis and was treated with prednisone.The patient symptomatically improved but 5 mo later presented with abdominal pain caused by perforation of the cecum.He underwent a cecectomy and pathology revealed pneumatosis cystoides intestinalis.This represents the first reported association between pneumatosis cystoides intestinalis and sarcoidosis.The etiology of pneumatosis cystoides intestinalis in this case was likely multifactorial and involved both effects of the corticosteroids as well as the advanced nature of the gastrointestinal sarcoidosis.Furthermore this case has the unique features of emphysematous lung changes and pancytopenia which are uncommon with sarcoidosis.
基金support of the National High Technology Research and Development Program of China(No.2002305205)the National Basic Research Program of China(No.51320006)
文摘Poly[(methylsilylene ethynylene phenylene ethynylene)-co-(tetramethyldisiloxane ethynylene phenylene ethynylene)]was synthesized by polycondensation reaction of m-diethynylbenzene magnesium reagent with 1,3-dichlorotetramethyldisiloxane and dichloromethylsilane.The copolymer was characterized by FT-IR,~1H NMR,differential scanning calorimetry and thermogravimetric analysis.The results show that the copolymer exhibits good processability and cures at low temperatures.The cured copolymer shows high thermal stability.