AIM: To assess the appropriateness of prescribing acid suppressive therapy (AST) in a general medicine service in a tertiary care hospital. METHODS: In this retrospective observational study, we reviewed the inpatient...AIM: To assess the appropriateness of prescribing acid suppressive therapy (AST) in a general medicine service in a tertiary care hospital. METHODS: In this retrospective observational study, we reviewed the inpatient records of all patients admitted to the general medical service in a tertiary care hospital in Beirut, Lebanon, from April 1 to May 31, 2011. Treatment with AST was considered appropriate if the patient had a specific indication or appropriate treatment purpose [e.g. , gastro-esophageal reflux disease (GERD), peptic ulcer disease, dyspepsia, acute or suspected gastrointestinal (GI) bleeding]. Appropriate administration of stress ulcer prophylaxis (SUP) was derived from an internal guideline that is based on the American Society of Health System Pharmacists guidelines. Prophylaxis was considered appropriate if a patient had 1 absolute indication (coagulopathy or requiring mechanical ventilation), or 2 or more relative indications (sepsis, occult bleeding, use of high dose corticosteroids, recent use of non-steroidal anti-inflammatory drugs for more than 3 mo, renal or liver failure, enteral feeding and anticoagulant use). RESULTS: Of the 153 patient admissions during the study period, 130 patients (85%) were started on AST, out of which 11 (8.5%) had a diagnosis that sup-ports the use of this therapy (GI bleed, gastritis and GERD), 16 (12.3%) had an absolute indication for SUP, 59 (45.4%) had 2 or more relative indications for SUP, and 44 (33.8%) received AST without an appropriate indication. In addition, one patient with an absolute indication for SUP and four with two or more relative indications did not receive AST. Rabeprazole was the most frequently used AST (59.2%), followed by omeprazole (24.6%), esomeprazole (11.6%) and ranitidine (4.6%). The dose of AST was appropriate in 126 patients (96.9%) and the route of administration was appropriate in 123 patients (94.6%). Fifteen of the admitted patients (10%) were discharged on AST, 7 of which (47%) did not have an appropriate indication. CONCLUSION: AST is overused in hospitalized noncritically ill patients and many patients are discharged on unnecessary AST which can increase cost, drug interactions and adverse events. Potential interventions include implementation of institutional protocols and prescriber education.展开更多
BACKGROUND: Interferon-alpha (IFN-alpha) is an important cytokine with multiple functions, but the target genes transactivated by IFN-alpha remain largely unknown. A study of such genes will help to understand the mec...BACKGROUND: Interferon-alpha (IFN-alpha) is an important cytokine with multiple functions, but the target genes transactivated by IFN-alpha remain largely unknown. A study of such genes will help to understand the mechanism of function of IFN-alpha. To isolate the gene transcripts specifically upregulated by IFN-alpha in HepG2 cells, we conducted suppressive subtractive hybridization (SSH) analysis. METHODS: SSH was used to analyze the target genes transactivated by recombinant IFN-alpha protein, and a subtractive cDNA library was constructed from HepG2 cells treated with recombinant IFN-alpha (rIFN-alpha, 2000 IU/ml) for 16 hours as tester, and cells not treated with rIFN-alpha as driver. The SSH PCR products from the library were cloned into pGEM-T easy vector and with BLASTX, the positive clones were randomly selected, sequenced and compared to the database in GenBank of the 35 differentially expressed gene fragments from the library, 6 clones showed significant homology to other known proteins. RESULTS: The subtractive cDNA library of genes upregulated by IFN-alpha was constructed successfully, rIFN-alpha upregulated the expression of the RAN binding protein 5 (RANBP5), NADH dehydrogenase, exosome component 3 (EXOSC3), zinc finger RNA binding protein, Dickkopf homolog 1 (DKK1) and acetyl-coenzyme A acetyltransferase 2 (ACAT2). CONCLUSIONS: These results suggest that rIFN-alpha can upregulate the expression of important genes to exert its functions, and provide new clues for discovering the molecular mechanisms of action of IFN-alpha.展开更多
BACKGROUND： Stereo-tactic radiation therapy （SRT） is widely used to treat intracranial diseases, but some patients suffered from radiation induced brain edema after SRT. Once radiation induced brain edema occurs, t...BACKGROUND： Stereo-tactic radiation therapy （SRT） is widely used to treat intracranial diseases, but some patients suffered from radiation induced brain edema after SRT. Once radiation induced brain edema occurs, the treatment is quite difficult, and it always leads to a poor outcome. Dexamethasone has certain therapeutic effect on traumatic brain edema, but the biological mechanism is still unclear. OBJECTIVE ： To observe the effect of dexamethasone on the neutrophil expression of CD18.DESIGN ： A randomized control observation.SETTING： Changhai Hospital of the Second Military Medical University of Chinese PLA. MATERIALS ： The experiment was carried out in Changhai Hospital of the Second Military Medical University of Chinese PLA from January 1999 to December 1999. Twenty SD rats （male and female each in half） weighing （250±50） g were used. METHODS： Twenty SD rats were divided into four groups at random. ① Blank control group （n=5）： The rats were not treated without dexamethasone or irradiation;② Irradiation group （n=5）： The rats were given irradiation but no dexamethasone treatment; ③ Irradiation＋1 mg/kg dexamethasone group （n=5）; The rats were treated with irradiation and dexamethasone of 1 mg/kg; ④Irradiation＋5 mg/kg dexamethasone group （n=5）： The rats were treated with irradiation and dexamethasone of 5 mg/kg. The heads of the rats were irradiated with 10 MeV X-ray （30 Gy）, and brain tissue was removed after 2 weeks to observe the pathological changes. Blood samples were taken from the carotid artery, gradient centrifugation was used, and neutrophile layer was obtained, the level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were detected with Northern blot and flow cytometry respectively. MAIN OUTCOME MEASURES： ① Blood cell count; ② Pathological results; ③ level of neutrophile expression of CD18 mRNA and quantity of membrane proteins. RESULTS ： All the 20 SD rats were involved in the analysis of results without deletion. At 2 weeks after irradiation, obvious cell injury could be observed under light microscope. The level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were obviously increased, but the severity of cell injury was relieved in the irradiation＋1 and 5 mg/kg dexamethasone groups, and the CD18 expression was markedly suppressed （P 〈 0.05）, and the suppression was more obvious in the irradiation＋5 mg/kg dexamethasone group than in the irradiation＋1 mg/kg dexamethasone group （P 〈 0.01 ）. CONCLUSION： Dexamethasone can reduce the radiation induced brain edema by inhibiting the expression of CD18.展开更多
Vascular wilt disease caused by Foe （Fusarium oxysporum f. sp. elaeidis） invades the host xylem and causes a devastating disease of oil palm in west and central Africa. This disease has not been reported in Southeas...Vascular wilt disease caused by Foe （Fusarium oxysporum f. sp. elaeidis） invades the host xylem and causes a devastating disease of oil palm in west and central Africa. This disease has not been reported in Southeast Asia, in spite of long term importation for breeding purposes of African seed and pollen, shown in this laboratory at the University of Bath to be contaminated with Foe disease epidemiology was recently studied in plantations in Ghana. Infection mainly occurred in clusters, implying root-root transmission rather than aerial spread by spores. Molecular diagnostic tools has being developed for： （1） rapid detection and quantification of Foe in plant tissue, soil, seed and pollen for quarantine purposes in order to prevent transcontinental spread of Foe; and （2） to test efficacy of putative disease resistant or tolerant palm genotypes. We have investigated the possibility of Foe-suppressive soils in Malaysia in order to explain the non-appearance of this vascular disease there and possibly to reveal other potential biocontrol agents. The explanation as to why Malaysia has not yet attained the disease is likely to revolve around the soil properties, in particular the microflora. This review reported that greater disease severity based on visual symptoms occurred in autoclaved soils and compost than in untreated soils when oil palm seedlings artificially infected with Foe.展开更多
Lysosomal acid lipase （LAL） cleaves cholesteryl esters （CE） and triglycerides （TG） to generate cholesterol and free fatty acid in lysosomes of cells. The down-stream metabolic products of fatty acids are ligands...Lysosomal acid lipase （LAL） cleaves cholesteryl esters （CE） and triglycerides （TG） to generate cholesterol and free fatty acid in lysosomes of cells. The down-stream metabolic products of fatty acids are ligands for activation of peroxisome proliferator-activated re-ceptor gamma （PPARγ）. Accumulation of CEs and TGs is resulted from lack of functional LAL in lysosomes of cells, especially in myeloid cells. One characteristic phenotype in LAL knock-out （ lal-/- ） mice is systemic elevation of myeloid-derived suppressive cells （MDSCs）. MDSCs infltrate into multiple distal organs, alter T cell development, and suppress T cell proliferation and lym-phokine production in lal-/- mice, which lead to severe pathogeneses in multiple organs. The gene transcrip-tional profle analysis in MDSCs from the bone marrow has identified multiple defects responsible for MDSCs malformation and malfunction in lal-/- mice, including G protein signaling, cell cycles, glycolysis metabolism, mitochondrial bioenergetics, mTOR pathway etc. In a sep-arate gene transcriptional profle analysis in the lung of lal-/- mice, matrix metalloproteinase 12 （MMP12） and apoptosis inhibitor 6 （Api6） are highly overexpressed due to lack of ligand synthesis for PPARγ. PPARγ nega-tively regulates MMP12 and Api6. Blocking the PPAR signaling by overexpression of a dominant negative PPARγ （dnPPARγ） form, or overexpressing MMP12 or Api6 in myeloid or lung epithelial cells in inducible transgenic mouse models results in elevated MDSCs and infammation-induced tumorigenesis. These stud-ies demonstrate that LAL and its downstream effectors are critical for MDSCs development, differentiation and malfunction.展开更多
Mesenchymal stem cells （MSCs）, derived from adult tissues, are multipotent progenitor cells, which hold great promise for regenerative medicine. Recent studies have shown that MSCs are immunosuppressive in vivo and ...Mesenchymal stem cells （MSCs）, derived from adult tissues, are multipotent progenitor cells, which hold great promise for regenerative medicine. Recent studies have shown that MSCs are immunosuppressive in vivo and in vitro in both animals and humans. However, the mechanisms that govern these immune modulatory functions of MSCs remain largely elusive. Some studies with bulk populations of MSCs indicated that soluble factors such as PGE2 and TGFβ are important, while others support a role for cell-cell contact. In this study, we intended to clarify these issues by examining immunosuppressive effects of cloned MSCs. We derived MSC clones from mouse bone marrow and showed that the majority of these clones were able to differentiate into adipocytes and osteoblast-like cells. Importantly, cells from these clones exhibited strong inhibitory effects on TCR activation-induced T cell proliferation in vitro, and injection of a small number of these cells promoted the survival of allogeneic skin grafts in mice. Conditioned medium from MSC cultures showed some inhibitory effect on anti-CD3 induced lymphocyte proliferation independent of PGE2 and TGFβ. In comparison, direct co-culture of MSCs with stimulated lymphocytes resulted in much stronger immunosuppressive effect. Interestingly, the suppression was bi-directional, as MSC proliferation was also reduced in the presence of lymphocytes. Taking together, our findings with cloned MSCs demonstrate that these cells exert their immunosuppressive effects through both soluble factor（s） and cell-cell contact, and that lymphocytes and MSCs are mutually inhibitory on their respective proliferation.展开更多
Sixty-eight cases of sterility due to excessive suppressive syndrome were treated by differential administration of Chinese drugs combined with clomiphene citrate and progesterone. This com-bined therapy was found to ...Sixty-eight cases of sterility due to excessive suppressive syndrome were treated by differential administration of Chinese drugs combined with clomiphene citrate and progesterone. This com-bined therapy was found to be significantly superior in therapeutic effect to administration of Western drugs alone or administration of Chinese drugs supplemented by progesterone. Resultant pregnancy rate was 57.4%.展开更多
Significant developments in cancer treatment have been made since the advent of immune therapies.However,there are still some patientswithmalignant tumors who do not benefit from immunotherapy.Tumors without immunogen...Significant developments in cancer treatment have been made since the advent of immune therapies.However,there are still some patientswithmalignant tumors who do not benefit from immunotherapy.Tumors without immunogenicity are called“cold”tumors which are unresponsive to immunotherapy,and the opposite are“hot”tumors.Immune suppressive cells(ISCs)refer to cells which can inhibit the immune response such as tumor-associated macrophages(TAMs),myeloid-derived suppressor cells(MDSCs),regulatory T(Treg)cells and so on.The more ISCs infiltrated,the weaker the immunogenicity of the tumor,showing the characteristics of“cold”tumor.The dysfunction of ISCs in the tumor microenvironment(TME)may play essential roles in insensitive therapeutic reaction.Previous studies have found that epigeneticmechanisms play an important role in the regulation of ISCs.Regulating ISCs may be a new approach to transforming“cold”tumors into“hot”tumors.Here,we focused on the function of ISCs in the TME and discussed how epigenetics is involved in regulating ISCs.In addition,we summarized the mechanisms by which the epigenetic drugs convert immunotherapy-insensitive tumors into immunotherapy-sensitive tumors which would be an innovative tendency for future immunotherapy in“cold”tumor.展开更多
Immunosuppressive mediators in tuberculosis pleurisy(pleural fluid(PF))are associated with the course of disease,but they remain poorly defined.To study the local immune status of patients with tuberculosis pleurisy,w...Immunosuppressive mediators in tuberculosis pleurisy(pleural fluid(PF))are associated with the course of disease,but they remain poorly defined.To study the local immune status of patients with tuberculosis pleurisy,we examined the effect of PF on the functions of T cells and the differentiation of Th1 cells.PF could inhibit the ability of T cells to produce cytokines.However,tumor-necrosis factor(TNF)-a derived from non-T cells was not impaired.Further analysis indicated that cell activation and cell cycle progression were also suppressed.Moreover,PF could inhibit Th1 cell differentiation.Importantly,we found that inhibitors of indoleamine 2,3-dioxygenase(IDO)and adenosine and neutralizing antibodies against IL-10 and transforming growth factor(TGF)-b could reverse cytokine production,suggesting that IDO,adenosine,IL-10 and Transforming growth factor–b1 in PF might take part in impairing T-cell functions.Taken together,our data demonstrate for the first time that several immunopathological factors participate in the downregulation of T-cell functions in local PF.展开更多
Foxp3^(+)regulatory T(Treg)cells play a critical role in peripheral tolerance.Bcl1O,acting as a scaffolding protein in the Carma1-Bcl10-Malt1(CBM)complex,has a critical role in TCR-induced signaling,leading to NF-kB a...Foxp3^(+)regulatory T(Treg)cells play a critical role in peripheral tolerance.Bcl1O,acting as a scaffolding protein in the Carma1-Bcl10-Malt1(CBM)complex,has a critical role in TCR-induced signaling,leading to NF-kB activation and is required for T-cell activation.The role of Bcl1O in conventional T(Tconv)cells has been well characterized;however,the role of Bcl1 in the development of Treg cells and the maintenance of the suppressive function and identity of these cells has not been well characterized.In this study,we found that Bcl10 was required for not only the development but also the function of Treg cells.After deleting Bcl1O in T cells,we found that the development of Treg cells was significantly impaired.When Bcl1O was specifically deleted in mature Treg cells,the suppressive function of the Treg cells was impaired,leading to lethal autoimmunity in Bcl10^(fl/fl)Foxp3^(cre) mice.Consistently,in contrast to WT Treg cells,Bcl10-deficient Treg cells could not protect Rag1-deficient mice from T-cell transfer-induced colitis.Furthermore,Bcl1O-deficient Treg cells downregulated the expression of a series of Treg-cell effector and suppressive genes and decreased effector Treg-cell populations.Moreover,Bcl1O-deficient Treg cells were converted into IFNγ-producing proinflammatory cells with increased expression of the transcription factors T-bet and HIF-1α.Together,our study results provide genetic evidence,indicating that Bcl1O is required for the development and function of Treg cells.展开更多
Background CD4^＋ T cells play a crucial role in the pathogenesis of aplastic anaemia. However, the mechanisms of over-proliferation, activation, infiltration of bone marrow and damage to haematopoietic ceils of CD4^...Background CD4^＋ T cells play a crucial role in the pathogenesis of aplastic anaemia. However, the mechanisms of over-proliferation, activation, infiltration of bone marrow and damage to haematopoietic ceils of CD4^＋ T cells in aplastic anaemia are unclear. Therefore, we screened differentially expressed genes of bone marrow CD4^＋ T cells of aplastic anaemia patients and normal donors by suppressive subtractive hybridization to investigate the pathogenesis of aplastic anaemia. Methods The bone marrow mononuclear cells of a first visit aplastic anaemia patient and a healthy donor of the same age and sex were isolated using lymphocyte separating medium by density gradient centrifugation. With the patients as ＂tester＂ and donor as ＂driver＂, their CD4^＋T cells were separated with magnetic bead sorting and a cDNA library established by suppressive subtractive hybridization. Then 15 of the resulting subtracted cDNA clones were randomly selected for DNA sequencing and homological analysis. With semiquantitative RT-PCR, bone marrow samples from 20 patients with aplastic anaemia and 20 healthy donors assessed the expression levels of differentially expressed genes from SSH library. Results PCR detected 89 clones in the library containing an inserted fragment of 100 bp to 700 bp. Among 15 sequenced clones, 12 were known genes including 3 repeated genes. Compared with normal donors, there were 9/12 genes over-expressed in bone marrow CD4^＋T cells of patients with aplastic anaemia. The effects of these genes included protein synthesis, biology oxidation, signal transduction, proliferative regulation and cell migration. Not all these genes had been reported in the mechanisms of haematopoietic damage mediated by CD4^＋ T cells in aplastic anaemia. Conclusions Screening and cloning genes, which regulate functions of CD4^＋ T cells, are helpful in elucidating the mechanisms of over proliferation, activation, infiltrating bone marrow and damaging haematopoietic cells of CD4^＋ T cells in aplasUc anaemia.展开更多
It has been well established that immune surveillance plays critical roles in preventing the occurrence and prog-ression of tumor.More and more evidence in recent years showed the host anti-tumor immune responses also...It has been well established that immune surveillance plays critical roles in preventing the occurrence and prog-ression of tumor.More and more evidence in recent years showed the host anti-tumor immune responses also play important roles in the chemotherapy and radiotherapy of cancers.Our previous study found that tumor-targeting therapy of anti-HER2/neu mAb is mediated by CD8+T cell responses.However,we found here that enhancement of CD8+T cell responses by combination therapy with IL-15R/IL-15 fusion protein or anti-CD40,which are strong stimultors for T cell responses,failed to promote the tumor therapeutic effects of anti-HER2/neu mAb.Analysis of tumor microenviornment showed that tumor tissues were heavily infiltrated with the immunosuppressive macrophages and most tumor infiltrating T cells,especially CD8^(+)T cells,expressed high level of inhibitory co-signaling receptor PD-1.These data suggest that tumor microenvironment is dominated by the immunosuppressive strategies,which thwart anti-tumor immune responses.Therefore,the successful tumor therapy should be the removal of inhibitory signals in the tumor microenvir-onment in combination with other therapeutic strategies.展开更多
Harnessing disease suppressive microbiomes constitutes a promising strategy for optimizing plant growth.However,relatively lttle information is available about the relationship between bulk and rhizosphere soil microb...Harnessing disease suppressive microbiomes constitutes a promising strategy for optimizing plant growth.However,relatively lttle information is available about the relationship between bulk and rhizosphere soil microbiomes.Here,the assembly of banana bulk soil and rhizosphere microbiomes was investigated in a mono-culture system consisting of bio-organic(BIO)and organic management practices.Applying BIO practice in newly reclaimed fields resulted in a high-efficiency biocontrol rate,thus providing a promising strategy for pre-control of Fusarium wilt disease.The soil microbiota was further characterized by MiSeq sequencing and quantitative PCR.The results indicate that disease suppression was mediated by the structure of a suppressive rhizosphere microbiome with respect to distinct community composition,diversity and abundance.Overall microbiome suppressiveness was primarily related to a particular set of enriched bacterial taxa affiliated with Pseudomonas,Terrimonas,Cupriavi-dus,Gp6,Ohtaekwangia and Duganella.Finally,struc-tural equation modeling was used to show that the changes in bulk soil bacterial community determined its induced rhizosphere bacterial community,which serves as an important and direct factor in restraining the pathogen.Collectively,this study provides an integrative approach to disentangle the biological basis of disease-suppressive microbiomes in the context of agricultural practice and soil management.展开更多
Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-dope...Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-doped cobalt molybdate(WDCMO)catalyst was synthesized for efficient and durable OER under neutral electrolyte.It is demonstrated that catalyst reconstruction is suppressed by W doping,which stabilizes the Co-O-Mo point-to-point connection in CoMoO_(4) architecture and stimulates to a lower valence state of active sites over the surface phase.Thereby,the surface structure maintains to avoid compound dissolution caused by over-oxidation during OER.Meanwhile,the WDCMO catalyst promotes charge transfer and optimizes*OH intermediate adsorption,which improves reaction kinetics and intrinsic activity.Consequently,the WDCMO electrode exhibits an overpotential of 302 mV at 10 mA cm^(-2) in neutral electrolyte with an improvement of 182 mV compared with CoMoO4 electrode.Furthermore,W doping significantly improves the electrode stability from 50 h to more than 320 h,with a suppressive potential attenuation from 2.82 to 0.29 mV h^(-1).This work will shed new light on designing rational electrocatalysts for neutral OER.展开更多
The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis u...A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis uses the standard k−εturbulence model for 4.5-and 12.75-inch pipes,and its accuracy is verified by comparing the results with large-scale hydrodynamic experiments.These experiments are designed to evaluate the suppression efficiency of VIV with and without helical strakes,focusing on displacement and drag coefficients under different flow conditions.Furthermore,the influence of important geometric parameters of the helical strakes on drag coefficients and VIV suppression efficiency at different flow rates is compared and discussed.Numerical results agree well with experimental data for drag coefficient and vortex shedding frequency.Spring-pipe self-excited vibration experimental tests reveal that the installation of helical strakes substantially reduces the drag coefficient of VIV within a certain flow rate range,achieving suppression efficiencies exceeding 90%with strake heights larger than 0.15D.Notably,the optimized parameter combination of helical strakes,with a pitch of 15D,a fin height of 0.2D,and 45°edge slopes,maintains high suppression efficiency,thereby exhibiting superior performance.This study provides a valuable reference for the design and application of helical strakes and VIV suppression in subsea engineering.展开更多
The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design c...The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.展开更多
A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the s...A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the spatial spectrum and the directions of arrival(DOA)of interferences to overcome the drawbacks associated with conventional adaptive beamforming(ABF)methods.The mainlobe interferences are identified by calculating the correlation coefficients between direction steering vectors(SVs)and rejected by the BMP pretreatment.Then,IAA is subsequently employed to reconstruct a sidelobe interference-plus-noise covariance matrix for the preferable ABF and residual interference suppression.Simulation results demonstrate the excellence of the proposed method over normal methods based on BMP and eigen-projection matrix perprocessing(EMP)under both uncorrelated and coherent circumstances.展开更多
Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challe...Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling.To address these issues,a new eutectic electrolyte based on Zn(ClO_(4))_(2)·6H_(2)O-N-methylacetamide(ZN)is proposed in this work.Compared with aqueous electrolyte,the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn^(2+),effectively suppressing zinc dendrite growth and side reactions.As a result,the Zn//NH4 V4 O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g^(-1).Therefore,this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn^(2+)solvation structure on the cycle stability,contributing to the exploration of novel electrolytes for high-performance AZIBs.展开更多
Osteoporosis represents a prevalent and debilitating comorbidity in patients diagnosed with type 2 diabetes mellitus(T2DM),which is characterized by suppressed osteoblast function and disrupted bone microarchitecture....Osteoporosis represents a prevalent and debilitating comorbidity in patients diagnosed with type 2 diabetes mellitus(T2DM),which is characterized by suppressed osteoblast function and disrupted bone microarchitecture.In this study,we utilized male C57BL/6 J mice to investigate the role of SIRT3 in T2DM.Decreased SIRT3 expression and impaired mitochondrial quality control mechanism are observed in both in vitro and in vivo models of T2DM.Mechanistically,SIRT3 suppression results in hyperacetylation of FOXO3,hindering the activation of the PINK1/PRKN mediated mitophagy pathway and resulting in accumulation of dysfunctional mitochondria.Genetical overexpression or pharmacological activation of SIRT3 restores deacetylation status of FOXO3,thus facilitating mitophagy and ameliorating osteogenic impairment in T2DM.Collectively,our findings highlight the fundamental regulatory function of SIRT3 in mitochondrial quality control,crucial for maintaining bone homeostasis in T2DM.These insights not only enhance our understanding of the molecular mechanisms underlying diabetic osteoporosis but also identify SIRT3 as a promising therapeutic target for diabetic osteoporosis.展开更多
文摘AIM: To assess the appropriateness of prescribing acid suppressive therapy (AST) in a general medicine service in a tertiary care hospital. METHODS: In this retrospective observational study, we reviewed the inpatient records of all patients admitted to the general medical service in a tertiary care hospital in Beirut, Lebanon, from April 1 to May 31, 2011. Treatment with AST was considered appropriate if the patient had a specific indication or appropriate treatment purpose [e.g. , gastro-esophageal reflux disease (GERD), peptic ulcer disease, dyspepsia, acute or suspected gastrointestinal (GI) bleeding]. Appropriate administration of stress ulcer prophylaxis (SUP) was derived from an internal guideline that is based on the American Society of Health System Pharmacists guidelines. Prophylaxis was considered appropriate if a patient had 1 absolute indication (coagulopathy or requiring mechanical ventilation), or 2 or more relative indications (sepsis, occult bleeding, use of high dose corticosteroids, recent use of non-steroidal anti-inflammatory drugs for more than 3 mo, renal or liver failure, enteral feeding and anticoagulant use). RESULTS: Of the 153 patient admissions during the study period, 130 patients (85%) were started on AST, out of which 11 (8.5%) had a diagnosis that sup-ports the use of this therapy (GI bleed, gastritis and GERD), 16 (12.3%) had an absolute indication for SUP, 59 (45.4%) had 2 or more relative indications for SUP, and 44 (33.8%) received AST without an appropriate indication. In addition, one patient with an absolute indication for SUP and four with two or more relative indications did not receive AST. Rabeprazole was the most frequently used AST (59.2%), followed by omeprazole (24.6%), esomeprazole (11.6%) and ranitidine (4.6%). The dose of AST was appropriate in 126 patients (96.9%) and the route of administration was appropriate in 123 patients (94.6%). Fifteen of the admitted patients (10%) were discharged on AST, 7 of which (47%) did not have an appropriate indication. CONCLUSION: AST is overused in hospitalized noncritically ill patients and many patients are discharged on unnecessary AST which can increase cost, drug interactions and adverse events. Potential interventions include implementation of institutional protocols and prescriber education.
文摘BACKGROUND: Interferon-alpha (IFN-alpha) is an important cytokine with multiple functions, but the target genes transactivated by IFN-alpha remain largely unknown. A study of such genes will help to understand the mechanism of function of IFN-alpha. To isolate the gene transcripts specifically upregulated by IFN-alpha in HepG2 cells, we conducted suppressive subtractive hybridization (SSH) analysis. METHODS: SSH was used to analyze the target genes transactivated by recombinant IFN-alpha protein, and a subtractive cDNA library was constructed from HepG2 cells treated with recombinant IFN-alpha (rIFN-alpha, 2000 IU/ml) for 16 hours as tester, and cells not treated with rIFN-alpha as driver. The SSH PCR products from the library were cloned into pGEM-T easy vector and with BLASTX, the positive clones were randomly selected, sequenced and compared to the database in GenBank of the 35 differentially expressed gene fragments from the library, 6 clones showed significant homology to other known proteins. RESULTS: The subtractive cDNA library of genes upregulated by IFN-alpha was constructed successfully, rIFN-alpha upregulated the expression of the RAN binding protein 5 (RANBP5), NADH dehydrogenase, exosome component 3 (EXOSC3), zinc finger RNA binding protein, Dickkopf homolog 1 (DKK1) and acetyl-coenzyme A acetyltransferase 2 (ACAT2). CONCLUSIONS: These results suggest that rIFN-alpha can upregulate the expression of important genes to exert its functions, and provide new clues for discovering the molecular mechanisms of action of IFN-alpha.
文摘BACKGROUND： Stereo-tactic radiation therapy （SRT） is widely used to treat intracranial diseases, but some patients suffered from radiation induced brain edema after SRT. Once radiation induced brain edema occurs, the treatment is quite difficult, and it always leads to a poor outcome. Dexamethasone has certain therapeutic effect on traumatic brain edema, but the biological mechanism is still unclear. OBJECTIVE ： To observe the effect of dexamethasone on the neutrophil expression of CD18.DESIGN ： A randomized control observation.SETTING： Changhai Hospital of the Second Military Medical University of Chinese PLA. MATERIALS ： The experiment was carried out in Changhai Hospital of the Second Military Medical University of Chinese PLA from January 1999 to December 1999. Twenty SD rats （male and female each in half） weighing （250±50） g were used. METHODS： Twenty SD rats were divided into four groups at random. ① Blank control group （n=5）： The rats were not treated without dexamethasone or irradiation;② Irradiation group （n=5）： The rats were given irradiation but no dexamethasone treatment; ③ Irradiation＋1 mg/kg dexamethasone group （n=5）; The rats were treated with irradiation and dexamethasone of 1 mg/kg; ④Irradiation＋5 mg/kg dexamethasone group （n=5）： The rats were treated with irradiation and dexamethasone of 5 mg/kg. The heads of the rats were irradiated with 10 MeV X-ray （30 Gy）, and brain tissue was removed after 2 weeks to observe the pathological changes. Blood samples were taken from the carotid artery, gradient centrifugation was used, and neutrophile layer was obtained, the level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were detected with Northern blot and flow cytometry respectively. MAIN OUTCOME MEASURES： ① Blood cell count; ② Pathological results; ③ level of neutrophile expression of CD18 mRNA and quantity of membrane proteins. RESULTS ： All the 20 SD rats were involved in the analysis of results without deletion. At 2 weeks after irradiation, obvious cell injury could be observed under light microscope. The level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were obviously increased, but the severity of cell injury was relieved in the irradiation＋1 and 5 mg/kg dexamethasone groups, and the CD18 expression was markedly suppressed （P 〈 0.05）, and the suppression was more obvious in the irradiation＋5 mg/kg dexamethasone group than in the irradiation＋1 mg/kg dexamethasone group （P 〈 0.01 ）. CONCLUSION： Dexamethasone can reduce the radiation induced brain edema by inhibiting the expression of CD18.
文摘Vascular wilt disease caused by Foe （Fusarium oxysporum f. sp. elaeidis） invades the host xylem and causes a devastating disease of oil palm in west and central Africa. This disease has not been reported in Southeast Asia, in spite of long term importation for breeding purposes of African seed and pollen, shown in this laboratory at the University of Bath to be contaminated with Foe disease epidemiology was recently studied in plantations in Ghana. Infection mainly occurred in clusters, implying root-root transmission rather than aerial spread by spores. Molecular diagnostic tools has being developed for： （1） rapid detection and quantification of Foe in plant tissue, soil, seed and pollen for quarantine purposes in order to prevent transcontinental spread of Foe; and （2） to test efficacy of putative disease resistant or tolerant palm genotypes. We have investigated the possibility of Foe-suppressive soils in Malaysia in order to explain the non-appearance of this vascular disease there and possibly to reveal other potential biocontrol agents. The explanation as to why Malaysia has not yet attained the disease is likely to revolve around the soil properties, in particular the microflora. This review reported that greater disease severity based on visual symptoms occurred in autoclaved soils and compost than in untreated soils when oil palm seedlings artificially infected with Foe.
基金Supported by National Institutes of Health,No.CA138759,CA152099,to Yan CHL087001,to Du H,and HL-061803 and HL-067862 to Yan C and Du H
文摘Lysosomal acid lipase （LAL） cleaves cholesteryl esters （CE） and triglycerides （TG） to generate cholesterol and free fatty acid in lysosomes of cells. The down-stream metabolic products of fatty acids are ligands for activation of peroxisome proliferator-activated re-ceptor gamma （PPARγ）. Accumulation of CEs and TGs is resulted from lack of functional LAL in lysosomes of cells, especially in myeloid cells. One characteristic phenotype in LAL knock-out （ lal-/- ） mice is systemic elevation of myeloid-derived suppressive cells （MDSCs）. MDSCs infltrate into multiple distal organs, alter T cell development, and suppress T cell proliferation and lym-phokine production in lal-/- mice, which lead to severe pathogeneses in multiple organs. The gene transcrip-tional profle analysis in MDSCs from the bone marrow has identified multiple defects responsible for MDSCs malformation and malfunction in lal-/- mice, including G protein signaling, cell cycles, glycolysis metabolism, mitochondrial bioenergetics, mTOR pathway etc. In a sep-arate gene transcriptional profle analysis in the lung of lal-/- mice, matrix metalloproteinase 12 （MMP12） and apoptosis inhibitor 6 （Api6） are highly overexpressed due to lack of ligand synthesis for PPARγ. PPARγ nega-tively regulates MMP12 and Api6. Blocking the PPAR signaling by overexpression of a dominant negative PPARγ （dnPPARγ） form, or overexpressing MMP12 or Api6 in myeloid or lung epithelial cells in inducible transgenic mouse models results in elevated MDSCs and infammation-induced tumorigenesis. These stud-ies demonstrate that LAL and its downstream effectors are critical for MDSCs development, differentiation and malfunction.
文摘Mesenchymal stem cells （MSCs）, derived from adult tissues, are multipotent progenitor cells, which hold great promise for regenerative medicine. Recent studies have shown that MSCs are immunosuppressive in vivo and in vitro in both animals and humans. However, the mechanisms that govern these immune modulatory functions of MSCs remain largely elusive. Some studies with bulk populations of MSCs indicated that soluble factors such as PGE2 and TGFβ are important, while others support a role for cell-cell contact. In this study, we intended to clarify these issues by examining immunosuppressive effects of cloned MSCs. We derived MSC clones from mouse bone marrow and showed that the majority of these clones were able to differentiate into adipocytes and osteoblast-like cells. Importantly, cells from these clones exhibited strong inhibitory effects on TCR activation-induced T cell proliferation in vitro, and injection of a small number of these cells promoted the survival of allogeneic skin grafts in mice. Conditioned medium from MSC cultures showed some inhibitory effect on anti-CD3 induced lymphocyte proliferation independent of PGE2 and TGFβ. In comparison, direct co-culture of MSCs with stimulated lymphocytes resulted in much stronger immunosuppressive effect. Interestingly, the suppression was bi-directional, as MSC proliferation was also reduced in the presence of lymphocytes. Taking together, our findings with cloned MSCs demonstrate that these cells exert their immunosuppressive effects through both soluble factor（s） and cell-cell contact, and that lymphocytes and MSCs are mutually inhibitory on their respective proliferation.
文摘Sixty-eight cases of sterility due to excessive suppressive syndrome were treated by differential administration of Chinese drugs combined with clomiphene citrate and progesterone. This com-bined therapy was found to be significantly superior in therapeutic effect to administration of Western drugs alone or administration of Chinese drugs supplemented by progesterone. Resultant pregnancy rate was 57.4%.
基金National Natural Science Foundation of China,Grant/Award Numbers:82373275,81974384,82173342,82203015China Postdoctoral Science Foundation,Grant/Award Number:2023JJ40942+3 种基金Nature Science Foundation of Hunan Province,Grant/Award Numbers:2021JJ3109,2021JJ31048,2023JJ40942Nature Science Foundation of Changsha,Grant/Award Number:73201CSCO Cancer Research Foundation,Grant/Award Numbers:Y-HR2019-0182,Y-2019Genecast-043the Key Research and Development Program of Hainan Province,Grant/Award Numbers:ZDYF2020228,ZDYF2020125。
文摘Significant developments in cancer treatment have been made since the advent of immune therapies.However,there are still some patientswithmalignant tumors who do not benefit from immunotherapy.Tumors without immunogenicity are called“cold”tumors which are unresponsive to immunotherapy,and the opposite are“hot”tumors.Immune suppressive cells(ISCs)refer to cells which can inhibit the immune response such as tumor-associated macrophages(TAMs),myeloid-derived suppressor cells(MDSCs),regulatory T(Treg)cells and so on.The more ISCs infiltrated,the weaker the immunogenicity of the tumor,showing the characteristics of“cold”tumor.The dysfunction of ISCs in the tumor microenvironment(TME)may play essential roles in insensitive therapeutic reaction.Previous studies have found that epigeneticmechanisms play an important role in the regulation of ISCs.Regulating ISCs may be a new approach to transforming“cold”tumors into“hot”tumors.Here,we focused on the function of ISCs in the TME and discussed how epigenetics is involved in regulating ISCs.In addition,we summarized the mechanisms by which the epigenetic drugs convert immunotherapy-insensitive tumors into immunotherapy-sensitive tumors which would be an innovative tendency for future immunotherapy in“cold”tumor.
基金the 115 grant(no.2008ZX10003011)the National Nature Science Foundation of China(no.30872300)the National Key Basic Research Program of China(973,no.2007CB512404).
文摘Immunosuppressive mediators in tuberculosis pleurisy(pleural fluid(PF))are associated with the course of disease,but they remain poorly defined.To study the local immune status of patients with tuberculosis pleurisy,we examined the effect of PF on the functions of T cells and the differentiation of Th1 cells.PF could inhibit the ability of T cells to produce cytokines.However,tumor-necrosis factor(TNF)-a derived from non-T cells was not impaired.Further analysis indicated that cell activation and cell cycle progression were also suppressed.Moreover,PF could inhibit Th1 cell differentiation.Importantly,we found that inhibitors of indoleamine 2,3-dioxygenase(IDO)and adenosine and neutralizing antibodies against IL-10 and transforming growth factor(TGF)-b could reverse cytokine production,suggesting that IDO,adenosine,IL-10 and Transforming growth factor–b1 in PF might take part in impairing T-cell functions.Taken together,our data demonstrate for the first time that several immunopathological factors participate in the downregulation of T-cell functions in local PF.
基金supported by grants from the National Natural Science Foundation of China(81570211 to X.L.and 31670904 to X.Z.)funding from the Tsinghua University-Peking University Jointed Center for Life Sciences(to X.L).
文摘Foxp3^(+)regulatory T(Treg)cells play a critical role in peripheral tolerance.Bcl1O,acting as a scaffolding protein in the Carma1-Bcl10-Malt1(CBM)complex,has a critical role in TCR-induced signaling,leading to NF-kB activation and is required for T-cell activation.The role of Bcl1O in conventional T(Tconv)cells has been well characterized;however,the role of Bcl1 in the development of Treg cells and the maintenance of the suppressive function and identity of these cells has not been well characterized.In this study,we found that Bcl10 was required for not only the development but also the function of Treg cells.After deleting Bcl1O in T cells,we found that the development of Treg cells was significantly impaired.When Bcl1O was specifically deleted in mature Treg cells,the suppressive function of the Treg cells was impaired,leading to lethal autoimmunity in Bcl10^(fl/fl)Foxp3^(cre) mice.Consistently,in contrast to WT Treg cells,Bcl10-deficient Treg cells could not protect Rag1-deficient mice from T-cell transfer-induced colitis.Furthermore,Bcl1O-deficient Treg cells downregulated the expression of a series of Treg-cell effector and suppressive genes and decreased effector Treg-cell populations.Moreover,Bcl1O-deficient Treg cells were converted into IFNγ-producing proinflammatory cells with increased expression of the transcription factors T-bet and HIF-1α.Together,our study results provide genetic evidence,indicating that Bcl1O is required for the development and function of Treg cells.
基金a grant from the National Natural Science Foundation of China(No.30570773)
文摘Background CD4^＋ T cells play a crucial role in the pathogenesis of aplastic anaemia. However, the mechanisms of over-proliferation, activation, infiltration of bone marrow and damage to haematopoietic ceils of CD4^＋ T cells in aplastic anaemia are unclear. Therefore, we screened differentially expressed genes of bone marrow CD4^＋ T cells of aplastic anaemia patients and normal donors by suppressive subtractive hybridization to investigate the pathogenesis of aplastic anaemia. Methods The bone marrow mononuclear cells of a first visit aplastic anaemia patient and a healthy donor of the same age and sex were isolated using lymphocyte separating medium by density gradient centrifugation. With the patients as ＂tester＂ and donor as ＂driver＂, their CD4^＋T cells were separated with magnetic bead sorting and a cDNA library established by suppressive subtractive hybridization. Then 15 of the resulting subtracted cDNA clones were randomly selected for DNA sequencing and homological analysis. With semiquantitative RT-PCR, bone marrow samples from 20 patients with aplastic anaemia and 20 healthy donors assessed the expression levels of differentially expressed genes from SSH library. Results PCR detected 89 clones in the library containing an inserted fragment of 100 bp to 700 bp. Among 15 sequenced clones, 12 were known genes including 3 repeated genes. Compared with normal donors, there were 9/12 genes over-expressed in bone marrow CD4^＋T cells of patients with aplastic anaemia. The effects of these genes included protein synthesis, biology oxidation, signal transduction, proliferative regulation and cell migration. Not all these genes had been reported in the mechanisms of haematopoietic damage mediated by CD4^＋ T cells in aplastic anaemia. Conclusions Screening and cloning genes, which regulate functions of CD4^＋ T cells, are helpful in elucidating the mechanisms of over proliferation, activation, infiltrating bone marrow and damaging haematopoietic cells of CD4^＋ T cells in aplasUc anaemia.
基金supported by grants from the National Natural Science Foundation of China(Grant No.91029719)the National Key Basic Research Program of China(No.2012CB917101).
文摘It has been well established that immune surveillance plays critical roles in preventing the occurrence and prog-ression of tumor.More and more evidence in recent years showed the host anti-tumor immune responses also play important roles in the chemotherapy and radiotherapy of cancers.Our previous study found that tumor-targeting therapy of anti-HER2/neu mAb is mediated by CD8+T cell responses.However,we found here that enhancement of CD8+T cell responses by combination therapy with IL-15R/IL-15 fusion protein or anti-CD40,which are strong stimultors for T cell responses,failed to promote the tumor therapeutic effects of anti-HER2/neu mAb.Analysis of tumor microenviornment showed that tumor tissues were heavily infiltrated with the immunosuppressive macrophages and most tumor infiltrating T cells,especially CD8^(+)T cells,expressed high level of inhibitory co-signaling receptor PD-1.These data suggest that tumor microenvironment is dominated by the immunosuppressive strategies,which thwart anti-tumor immune responses.Therefore,the successful tumor therapy should be the removal of inhibitory signals in the tumor microenvir-onment in combination with other therapeutic strategies.
基金This research was funded by the National Key Research and Development Program(2017YFD0202101)the National Natural Science Foundation of China(31672239 and 31972509)+1 种基金the 111 project(B12009),the Priority Academic Program Development of the Jiangsu Higher Education Institutions(PAPD)the Innovative Research Team Development Plan of the Ministry of Education of China(IRT17R56).
文摘Harnessing disease suppressive microbiomes constitutes a promising strategy for optimizing plant growth.However,relatively lttle information is available about the relationship between bulk and rhizosphere soil microbiomes.Here,the assembly of banana bulk soil and rhizosphere microbiomes was investigated in a mono-culture system consisting of bio-organic(BIO)and organic management practices.Applying BIO practice in newly reclaimed fields resulted in a high-efficiency biocontrol rate,thus providing a promising strategy for pre-control of Fusarium wilt disease.The soil microbiota was further characterized by MiSeq sequencing and quantitative PCR.The results indicate that disease suppression was mediated by the structure of a suppressive rhizosphere microbiome with respect to distinct community composition,diversity and abundance.Overall microbiome suppressiveness was primarily related to a particular set of enriched bacterial taxa affiliated with Pseudomonas,Terrimonas,Cupriavi-dus,Gp6,Ohtaekwangia and Duganella.Finally,struc-tural equation modeling was used to show that the changes in bulk soil bacterial community determined its induced rhizosphere bacterial community,which serves as an important and direct factor in restraining the pathogen.Collectively,this study provides an integrative approach to disentangle the biological basis of disease-suppressive microbiomes in the context of agricultural practice and soil management.
文摘Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-doped cobalt molybdate(WDCMO)catalyst was synthesized for efficient and durable OER under neutral electrolyte.It is demonstrated that catalyst reconstruction is suppressed by W doping,which stabilizes the Co-O-Mo point-to-point connection in CoMoO_(4) architecture and stimulates to a lower valence state of active sites over the surface phase.Thereby,the surface structure maintains to avoid compound dissolution caused by over-oxidation during OER.Meanwhile,the WDCMO catalyst promotes charge transfer and optimizes*OH intermediate adsorption,which improves reaction kinetics and intrinsic activity.Consequently,the WDCMO electrode exhibits an overpotential of 302 mV at 10 mA cm^(-2) in neutral electrolyte with an improvement of 182 mV compared with CoMoO4 electrode.Furthermore,W doping significantly improves the electrode stability from 50 h to more than 320 h,with a suppressive potential attenuation from 2.82 to 0.29 mV h^(-1).This work will shed new light on designing rational electrocatalysts for neutral OER.
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
基金Supported by the National Natural Science Foundation of China (Grant No. 52222111)the National Science and Technology Major Project of China “Key Technologies and Equipment for Deepwater Dry Oil and Gas Production and Processing Platforms”(No. 2024ZD1403300)+1 种基金Subproject 5 “Research on Safety Risk Assessment Technology System for Deepwater Dry Oil and Gas Production and Processing Platforms”(No. 2024ZD1403305)the China Scholarship Council (202306440019)。
文摘A numerical simulation analysis is conducted to examine the unsteady hydrodynamic characteristics of vortex-induced vibration(VIV)and the suppression effect of helical strakes on VIV in subsea pipelines.The analysis uses the standard k−εturbulence model for 4.5-and 12.75-inch pipes,and its accuracy is verified by comparing the results with large-scale hydrodynamic experiments.These experiments are designed to evaluate the suppression efficiency of VIV with and without helical strakes,focusing on displacement and drag coefficients under different flow conditions.Furthermore,the influence of important geometric parameters of the helical strakes on drag coefficients and VIV suppression efficiency at different flow rates is compared and discussed.Numerical results agree well with experimental data for drag coefficient and vortex shedding frequency.Spring-pipe self-excited vibration experimental tests reveal that the installation of helical strakes substantially reduces the drag coefficient of VIV within a certain flow rate range,achieving suppression efficiencies exceeding 90%with strake heights larger than 0.15D.Notably,the optimized parameter combination of helical strakes,with a pitch of 15D,a fin height of 0.2D,and 45°edge slopes,maintains high suppression efficiency,thereby exhibiting superior performance.This study provides a valuable reference for the design and application of helical strakes and VIV suppression in subsea engineering.
基金supported by the National Natural Science Foundation of China(Nos.22208221,22178221)the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)+1 种基金the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)the Start-up Research Funding of Shenzhen University(No.868-000001032522).
文摘The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.
基金The National Natural Science Foundation of China(No.U19B2031).
文摘A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the spatial spectrum and the directions of arrival(DOA)of interferences to overcome the drawbacks associated with conventional adaptive beamforming(ABF)methods.The mainlobe interferences are identified by calculating the correlation coefficients between direction steering vectors(SVs)and rejected by the BMP pretreatment.Then,IAA is subsequently employed to reconstruct a sidelobe interference-plus-noise covariance matrix for the preferable ABF and residual interference suppression.Simulation results demonstrate the excellence of the proposed method over normal methods based on BMP and eigen-projection matrix perprocessing(EMP)under both uncorrelated and coherent circumstances.
基金supported by the Natural Science Foundation of Henan Province(No.242300420021)the Major Science and Technology Projects of Henan Province(No.221100230200)+4 种基金the Open Fund of State Key Laboratory of Advanced Refractories(No.SKLAR202210)the Key Science and Technology Program of Henan Province(No.232102241020)the Undergraduate Innovation and Entrepreneurship Training Program of Henan Province(No.S202310464012)the Ph.D.Research Startup Foundation of Henan University of Science and Technology(No.400613480015)the Postdoctoral Research Startup Foundation of Henan University of Science and Technology(No.400613554001).
文摘Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling.To address these issues,a new eutectic electrolyte based on Zn(ClO_(4))_(2)·6H_(2)O-N-methylacetamide(ZN)is proposed in this work.Compared with aqueous electrolyte,the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn^(2+),effectively suppressing zinc dendrite growth and side reactions.As a result,the Zn//NH4 V4 O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g^(-1).Therefore,this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn^(2+)solvation structure on the cycle stability,contributing to the exploration of novel electrolytes for high-performance AZIBs.
基金supported by the National Key Research and Development Project (2021YFA1201404)National Natural Science Foundation of China Major Project (81991514)+6 种基金General Project (82272530, 82372459)Jiangsu Province Medical Innovation Center of Orthopedic Surgery (CXZX202214)Jiangsu Provincial Key Medical Center FoundationJiangsu Provincial Medical Outstanding Talent FoundationJiangsu Provincial Medical Youth Talent FoundationJiangsu Provincial Key Medical Talent Foundationthe Fundamental Research Funds for the Central Universities (14380493, 14380494)
文摘Osteoporosis represents a prevalent and debilitating comorbidity in patients diagnosed with type 2 diabetes mellitus(T2DM),which is characterized by suppressed osteoblast function and disrupted bone microarchitecture.In this study,we utilized male C57BL/6 J mice to investigate the role of SIRT3 in T2DM.Decreased SIRT3 expression and impaired mitochondrial quality control mechanism are observed in both in vitro and in vivo models of T2DM.Mechanistically,SIRT3 suppression results in hyperacetylation of FOXO3,hindering the activation of the PINK1/PRKN mediated mitophagy pathway and resulting in accumulation of dysfunctional mitochondria.Genetical overexpression or pharmacological activation of SIRT3 restores deacetylation status of FOXO3,thus facilitating mitophagy and ameliorating osteogenic impairment in T2DM.Collectively,our findings highlight the fundamental regulatory function of SIRT3 in mitochondrial quality control,crucial for maintaining bone homeostasis in T2DM.These insights not only enhance our understanding of the molecular mechanisms underlying diabetic osteoporosis but also identify SIRT3 as a promising therapeutic target for diabetic osteoporosis.
