Rubble deposits with a high concentration of rock debris were created after the powerful earthquakes in Jiuzhaigou.Because of the restricted soil resources,water leaks,and nutrient deficits,these deposits pose serious...Rubble deposits with a high concentration of rock debris were created after the powerful earthquakes in Jiuzhaigou.Because of the restricted soil resources,water leaks,and nutrient deficits,these deposits pose serious obstacles for vegetation regeneration.The purpose of this study was to investigate the main mechanisms controlling soil water retention and evaluate the effects of different amendments on the hydraulic characteristics and water-holding capacity of collapsed rubble soils.Finegrained soil,forest humus,crushed straw,and organic components that retain water were added to the altered soils to study the pore structure images and soil-water characteristic curves.Comparing understory humus to other supplements,the results showed a considerable increase in the soil's saturated and wilting water content.The saturated water content and wilting water content rose by 17.9%and 4.3%,respectively,when the percentage of understory soil reached 30%.Additionally,the enhanced soil's microporosity and total pore volume increased by 45.33%and 11.27%,respectively,according to nuclear magnetic imaging.It was shown that while clay particles and organic matter improved the soil's ability to adsorb water,they also increased the soil's total capacity to store water.Fine particulate matter did this by decreasing macropores and increasing capillary pores.These results offer an essential starting point for creating strategies for soil repair that would encourage the restoration of plants on slopes that have been damaged.展开更多
BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a cr...BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a crucial intervention in mitigating these risks.However,the metabolic effects of COVID-19 vaccination,particularly the Johnson&Johnson(J&J)vaccine,in diabetic populations remain inadequately explored.This study investigated the longitudinal effects of the J&J vaccine on lipid and eicosanoid biomarkers to assess its metabolic safety and potential cardiovascular benefits.AIM To evaluate the long-term impact of the J&J COVID-19 vaccine on lipid and eicosanoid biomarkers in Ethiopian patients with T2DM.METHODS This prospective cohort study was conducted at Adama Hospital Medical College(Oromia,Ethiopia)from May 2023 to June 2024.A total of 224 T2DM patients(57 vaccinated,167 unvaccinated)were monitored for 1 year.Biomarkers including triglycerides(TGs),high-density lipoprotein(HDL),total cholesterol(TC),pro-staglandins(PGs),and thromboxanes(TXs)were measured at baseline and at 3 months,6 months,9 months,and 1 year post-vaccination.Statistical analyses included Generalized Estimating Equations to assess longitudinal biomarker changes.RESULTS TG and PG levels remained stable across all time points.HDL levels showed a temporary decline at 3 months(mean difference[MD]=-4.33;P<0.001)and 6 months(MD=-2.62;P<0.001)but recovered by 9 months(MD=2.09;P=0.001)and 1 year(MD=2.38;P<0.001).TC exhibited a significant decrease at 3 months(MD=-16.44,P=0.001)before stabilizing.TX levels showed a consistent decline across all follow-ups(e.g.,1 year:MD=-0.08;P=0.036),suggesting a reduced thrombotic risk.Correlation analysis indicated significant interrelations among biomarkers,emphasizing their roles in metabolic and inflammatory pathways.CONCLUSION The J&J COVID-19 vaccine exhibited metabolic safety in patients with T2DM,with transient HDL and TC reductions that later stabilized and a sustained TX decline,suggesting potential cardiovascular benefits.Further studies are needed to explore long-term immunometabolic effects on high-risk populations.展开更多
The Moroccan automotive industry is experiencing steady growth,positioning itself as the largest manufacturer of passenger cars in Africa.This expansion is leading to a significant increase in waste generation,particu...The Moroccan automotive industry is experiencing steady growth,positioning itself as the largest manufacturer of passenger cars in Africa.This expansion is leading to a significant increase in waste generation,particularly from end-of-life vehicles(ELVs),which require proper dismantling and disposal to minimize environmental harm.Millions of tonnes of automotive waste are generated annually,necessitating efficient waste management strategies to mitigate environmental and health risks.ELVs contain hazardous substances such as heavy metals,oils,and plastics,which,if not properly managed,can contaminate soil and water resources.To address this challenge,reverse logistics networks play a crucial role in optimizing the recovery of used components,enhancing recycling efficiency,and ensuring the safe disposal of hazardous and non-recyclable waste.This paper introduces a mathematical programming model designed to minimize the total costs associated with ELVs collection,treatment,and transportation while also accounting for revenues from the resale of repaired,directly reusable,or recycled components.The proposed model determines the optimal locations for processing facilities and establishes efficient material flows within the reverse logistics network.By integrating economic and environmental considerations,this model supports the development of a sustainable and cost-effective automotive waste management system,ultimately contributing to a circular economy approach in the industry.展开更多
Objectives:Exosomal long noncoding RNAs(lncRNAs)might facilitate epithelial–mesenchymal transition(EMT)in liver cancer after transarterial chemoembolization(TACE),thereby enhancing tumor cell invasiveness and migrati...Objectives:Exosomal long noncoding RNAs(lncRNAs)might facilitate epithelial–mesenchymal transition(EMT)in liver cancer after transarterial chemoembolization(TACE),thereby enhancing tumor cell invasiveness and migration.This study investigated the prognostic role of plasma exosomal long noncoding RNA-plasmacytoma variant translocation 1(lncRNA-PVT1)in TACE treated hepatocellular carcinoma(HCC).Methods:Plasma exosomal lncRNA-PVT1 was evaluated via qPCR before and after TACE.Hepatoma cell behavior was investigated in different HCC cell lines.A lncRNA-PVT1 plasmid was synthesized and overexpressed,and si-lncRNA PVT1 was transfected into poorly invasive cells to reveal its influence on cell characteristics.The lncRNA-PVT1–FoxM1 interaction was elucidated using a double-luciferase reporter gene assay.The effect of miRNA-345-5p on minimally invasive hepatoma cells was assessed.Three experimental groups were established:poorly invasive cells,poorly invasive cells co-cultured with exosomes from hypoxia-induced highly invasive cells,and poorly invasive cells co-cultured with normal hepatocyte exosomes.Liver cancer cells were subcutaneously inoculated into nude mice,with subsequent observations of weight,tumor formation,and tumor size.Results:We identified two lncRNAs(lncRNA-PVT1 and GAPLINC)associated with EMT in the hypoxic microenvironment of liver cancer.Cox multivariate regression analysis was used to establish a prognostic model distinguishing high-and low-risk groups.Hypoxia-induced HepG2 exosomes significantly promoted EMT in poorly invasive HCC cells.LncRNA-PVT1 overexpression and silencing altered E-cadherin,vimentin,and FoxM1 expression,cell proliferation,invasion,migration,and apoptosis.miR-345-5p directly targeted lncRNA-PVT1 and FoxM1,affecting downstream targets.In vivo,co-culturing poorly invasive hepatoma cells with exosomes from highly invasive cells increased tumor volumes,upregulated lncRNA-PVT1,FoxM1,Ki67,and MMP9 expression,and downregulated miR-345-5p expression.Conclusions:Plasma exosomal lncRNA-PVT1 expression is upregulated in highly invasive cells post-hypoxia,potentially serving as a biomarker for evaluating liver cancer prognosis after TACE.Through a miRNA-345-5p-mediated competing endogenous RNA mechanism,it promotes EMT in poorly invasive cells,likely contributing to recurrence and metastasis post-HCC interventional embolization.展开更多
We aimed to evaluate the efficacy of tricyclic antidepressants(TCAs) as a therapeutic option for irritable bowel syndrome(IBS) through meta-analysis of randomized controlled trials.For the years 1966 until September 2...We aimed to evaluate the efficacy of tricyclic antidepressants(TCAs) as a therapeutic option for irritable bowel syndrome(IBS) through meta-analysis of randomized controlled trials.For the years 1966 until September 2008,PubMed,Scopus,Web of Science,and Cochrane Central Register of Controlled Trials were searched for double-blind,placebo-controlled trials investigating the effi cacy of TCAs in the management of IBS.Seven randomized,placebo-controlled clinical trials met our criteria and were included in the metaanalysis.TCAs used in the treatment arm of these trials included amitriptyline,imipramine,desipramine,doxepin and trimipramine.The pooled relative risk for clinical improvement with TCA therapy was 1.93(95% CI:1.44 to 2.6,P<0.0001).Effect size of TCAs versus placebo for mean change in abdominal pain score among the two studies was -44.15(95% CI:-53.27 to -35.04,P<0.0001).It is concluded that low dose TCAs exhibit clinically and statistically signifi cant control of IBS symptoms.展开更多
Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammator...Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.展开更多
We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and all relevant lit...We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and all relevant literature were searched from 1965 to June 2009 for any placebo-controlled clinical trials of mebeverine, using search terms such as mebeverine, clinical trials, and IBS. Eight randomized trials met our criteria, including six trials that compared mebeverine with placebo and two that compared mebeverine tablets with capsules. These eight trials included 555 patients randomized to receive either mebeverine or placebo with 352 (63%)women and 203 (37%) men in all subtypes of IBS. The pooled relative risk (RR) for clinical improvement of mebeverine was 1.13 (95% CI: 0.59-2.16, P = 0.7056) and 1.33 (95% CI: 0.92-1.93, P = 0.129) for relief of abdominal pain. The efficacy of mebeverine 200 mg compared to mebeverine 135 mg indicated RRs of 1.12 (95% CI: 0.96-1.3, P = 0.168) for clinical or global improvement and 1.08 (95% CI: 0.87-1.34, P = 0.463) for relief of abdominal pain. Thus, mebeverine is mostly well tolerated with no signif icant adverse effects; however, its eff icacy in global improvement of IBS is not statistically signif icant.展开更多
We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic...We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis （AP） or chronic pancreatitis （CP） and in the prevention of post-endoscopic retrograde cholangio-pancreatography （post-ERCP） pancreatitis （PEP） up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.展开更多
In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,...In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking process.In the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain operations.In addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 utilization.The results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2.展开更多
Objective To study the effect of electromagnetic pulse （EMP） exposure on the permeability of blood-testicle barrier （BTB） in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with...Objective To study the effect of electromagnetic pulse （EMP） exposure on the permeability of blood-testicle barrier （BTB） in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.展开更多
Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert ma...Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert materials.Thus,repairing or improving the microenvironment of damaged bone tissue is of great significance for bone rescue,reconstruction,and regeneration,which is still a major medical challenge.Oxidative stress(OS)and oxygen(O_(2))deficiency are considered to be specific physiological signals of the bone-injury microenvironment.From the above background,a coating consisting of manganese dioxide(MnO_(2))nanoenzyme and strontium(Sr)ions was fabricated on the surface of the Ti implant via a one-step hydrothermal treatment.MnO_(2) nanoenzyme presented in the coating alleviated OS and O_(2) deficiency at the injury site by catalyzing the decomposition of abundant endogenous H_(2)O_(2) around the modified Ti implants into O_(2).In addition,Sr ions were released from the surface of the implant at a certain rate in a body-fluid environment,further promoting the adhesion,growth,and osteogenic differentiation of mesenchymal stem cells.More importantly,a Sprague Dawley rat femur model demonstrated that the modified Ti implant showed significant potential to accelerate bone tissue reconstruction in vivo.In sum-mary,the present system provides a new idea for the treatment of bone injury and the development of new orthopedic implants.展开更多
Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studi...Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studied fully.Here,we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular dementia.Eight weeks after model establishment,rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 weeks.Behavioral assessment in the Morris water maze showed that model rats had longer escape latencies in training trials,and spent less time swimming in the target quadrant in probe trials,than sham-operated rats.However,rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model rats.Hematoxylin-eosin and Nissl staining revealed less neuronal necrosis and pathological damage,and more living cells,in the hippocampus of rats treated with tetrandrine than in untreated model rats.Western blot assay showed that interleukin-1β expression,and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472,were lower in model rats that received tetrandrine than in those that did not.The present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression,N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472,and neuronal necrosis.展开更多
A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are so...A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are solved by the integral method which encompasses the Gaussian profiles of velocity and density. The action of waves is incorporated into the equations of motion as an external force and a new exact solution is obtained to predict the trajectory, velocity distribution and boundary thickness of the buoyant jet over an arbitrary lateral cross section. It is found that the velocity along the centerline is inversely proportional to the ratio of the momentum of the wave to the buoyant jet. The averaged bound- ary width varies with the fluctuation of the boundary width, the distance from the orifice and the velocity correction function. Owing to the motion of waves, the fluctuation of the boundary width is proportional to the wave steepness.展开更多
The structural, electronic, and optical properties of cubic perovskite NaMgF3 are calculated by plane-wave pseudopo- tential density functional theory. The calculated lattice constant a0, bulk modulus B0, and the deri...The structural, electronic, and optical properties of cubic perovskite NaMgF3 are calculated by plane-wave pseudopo- tential density functional theory. The calculated lattice constant a0, bulk modulus B0, and the derivative of bulk modulus B~ are 3.872/~, 78.2 GPa, and 3.97, respectively. The results are in good agreement with the available experimental and theo- retical values. The electronic structure shows that cubic NaMgF3 is an indirect insulator with a wide forbidden band gap of Eg = 5.90 eV. The contribution of the different bands is analyzed by total and partial density of states curves. Population analysis of NaMgF3 indicates that there is strong ionic bonding in the MgF2 unit, and a mixture of ionic and weak covalent bonding in the NaF unit. Calculations of dielectric function, absorption coefficient, refractive index, electronic energy loss spectroscopy, optical reflectivity, and conductivity are also performed in the energy range 0 to 70 eV.展开更多
The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a new...The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid （RA） was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin （STZ）-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.展开更多
We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS ...We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS technology, and the TiOx/TiNx cell array is formed by rf magnetron sputtering and reactive ion etching. In current-voltage （I- V） measurement for current-sweeping mode, large snap-back of voltage is observed, which indicates that the sample changes from high-resistance state （HRS） to low-resistance state （LRS）. In the I-V measurement for voltage-sweeping mode, large current collapse is observed, which indicates that the sample changes from LRS to HRS. The current difference between HRS and LRS is about two orders. The threshold current and voltage for the resistance change is about 5.0- 10^-5 A and 2.5 V, respectively. The pulse voltage can also change the resistance and the pulse time is as shorter as 30 ns for the resistance change. These properties of TiOx/TiNx film are comparable to that of conventional phase-change material, which makes it possible for RRAM application.展开更多
Combined with the kinetic model of liquid film spreading, a new numerical method of solid-liquid-gas three-phase flow was developed for the moving of contact line, which was a hybrid method of computational fluid dyna...Combined with the kinetic model of liquid film spreading, a new numerical method of solid-liquid-gas three-phase flow was developed for the moving of contact line, which was a hybrid method of computational fluid dynamics and lattice Boltzmalm method （LBM）. By taking the effect of molecule force in droplet and the wall surface on liquid film into account, the changing law of contact angle with different surface tensions was analyzed on glass and aluminum foil surfaces. Compared with experimental results, the standard deviation by using LBM is less than 0.5°, which validates the feasibility of LBM simulation on the dynamic process of liquid film spreading. In addition, oscillations are discovered both at the initial and end phases. The phenomenon of retraction is also found and the maximum retraction angle is 7.58°. The obtained result shows that the retraction is proved to be correlative with precursor film by tracking the volume change of liquid film contour. Furthermore, non-dimensional coefficient 2 is introduced to measure the liquid film retraction capacity.展开更多
Nowadays, in China, the bottom-blowing technique plays an important role in accelerating the molten bath stirring and promoting the metallurgical reactions in electric arc furnace (EAF) steelmaking. The innovations of...Nowadays, in China, the bottom-blowing technique plays an important role in accelerating the molten bath stirring and promoting the metallurgical reactions in electric arc furnace (EAF) steelmaking. The innovations of bottom-blowing technologies in EAF steelmaking were reviewed. The optimized bottom-blowing arrangement in EAF based on the furnace structure and the position of electrodes was introduced, and the fluid flow characteristics of EAF molten bath with bottomblowing were analyzed. Furthermore, bottom-blowing CO2 in EAF can facilitate the carbon-oxygen reaction reaching equilibrium and decrease the content of nitrogen in molten steel due to its special metallurgical properties. Pulsating bottom-blowing in EAF can effectively improve the molten bath stirring through the action of the unsteady bottom blowing gas streams, which could make the fluid flow field more disorderly than the steady bottom-blowing. And submerged O2 injection with CO2 in EAF can noticeably strengthen the EAF molten bath stirring, increase the production efficiency and improve the molten steel quality.展开更多
Drimia genus includes plants that used from ancient time for various ailments such as dropsy, respiratory ailment, bone and joint complications,skin disorders, epilepsy and cancer. Toxic properties of some Drimia spec...Drimia genus includes plants that used from ancient time for various ailments such as dropsy, respiratory ailment, bone and joint complications,skin disorders, epilepsy and cancer. Toxic properties of some Drimia species also were noted by ancient scientists and these plants have been traditionally used for rat control. Bufadienolides have been identified as the main constituents in the genus of Drimia. Phenolics, sterols, protein and some of other phytochemicals have been also isolated from these plants. Pharmacological and clinical studies have strongly approved their effect on cardiovascular system. Extracts and compounds isolated from Drimia species showed biological activities such as antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory and insecticidal effects throughseveral in vivo and in vitro studies. Moreover, cytotoxic and antitumor activities which may be related to bufadienolide content of these plants have been considered by many researchers. Traditional therapeutic values of these plants for treating respiratory and rheumatic ailments as well as skin disorders are needed to be validated through more researches. Toxic effects of these plants and isolated compounds have been investigated through several in vivo studies. Drimia plants and their isolated compounds have narrow therapeutic index, so patients should be prohibited from applying these plants without medical supervision and should be informed about the main intoxication symptoms before starting treatment. Moreover, interaction of Drimia plants with other constituents of traditional herbal mixtures as well as chemical and biological modalities for reducing toxicity of bufadienolide compounds can be subjected for future studies.展开更多
With the importance of the steelmaking industry in the economy and its negative impacts on the environment,reducing dust emissions is a vital focus in this field.Thus,the theory of dust generation in converter steelma...With the importance of the steelmaking industry in the economy and its negative impacts on the environment,reducing dust emissions is a vital focus in this field.Thus,the theory of dust generation in converter steelmaking process was analyzed and the influence of bottom blowing oxygen on dust generation was obtained through experimental research.The industrial test was carried out in a 120-t bottom combined blown O_(2)–CaO steelmaking converter.The results show that lowering the lance position can reduce the amount of dust.This emission rate of the converter is also found to be in direct proportion to the decarburization rate.As a result,the proposed bottom blowing O_(2)–CaO steelmaking converter can technically reduce the amount of dust and improve the recovery rate of iron.With more bottom blowing oxygen,the dust content is lower with the dust peak appearing earlier.The evaporation theory,followed by the bubble theory,plays the primary role in the dust generation of bottom blowing oxygen steelmaking.It points out the direction for the technology research and development of reducing dust generation.展开更多
基金jointly funded by the Sichuan Provincial Natural Science Foundation of China(Grant No.2023NSFSC0378)the Jiuzhaigou Lake Swamp and River Ecological Restoration Research Project(N5132112022000246)the Research base and Support provided by Jiuzhaigou Administration for this study。
文摘Rubble deposits with a high concentration of rock debris were created after the powerful earthquakes in Jiuzhaigou.Because of the restricted soil resources,water leaks,and nutrient deficits,these deposits pose serious obstacles for vegetation regeneration.The purpose of this study was to investigate the main mechanisms controlling soil water retention and evaluate the effects of different amendments on the hydraulic characteristics and water-holding capacity of collapsed rubble soils.Finegrained soil,forest humus,crushed straw,and organic components that retain water were added to the altered soils to study the pore structure images and soil-water characteristic curves.Comparing understory humus to other supplements,the results showed a considerable increase in the soil's saturated and wilting water content.The saturated water content and wilting water content rose by 17.9%and 4.3%,respectively,when the percentage of understory soil reached 30%.Additionally,the enhanced soil's microporosity and total pore volume increased by 45.33%and 11.27%,respectively,according to nuclear magnetic imaging.It was shown that while clay particles and organic matter improved the soil's ability to adsorb water,they also increased the soil's total capacity to store water.Fine particulate matter did this by decreasing macropores and increasing capillary pores.These results offer an essential starting point for creating strategies for soil repair that would encourage the restoration of plants on slopes that have been damaged.
文摘BACKGROUND The coronavirus disease 2019(COVID-19)pandemic has disproportionately impacted individuals with type 2 diabetes mellitus(T2DM),increasing their risk of severe illness and mortality.Vaccination has been a crucial intervention in mitigating these risks.However,the metabolic effects of COVID-19 vaccination,particularly the Johnson&Johnson(J&J)vaccine,in diabetic populations remain inadequately explored.This study investigated the longitudinal effects of the J&J vaccine on lipid and eicosanoid biomarkers to assess its metabolic safety and potential cardiovascular benefits.AIM To evaluate the long-term impact of the J&J COVID-19 vaccine on lipid and eicosanoid biomarkers in Ethiopian patients with T2DM.METHODS This prospective cohort study was conducted at Adama Hospital Medical College(Oromia,Ethiopia)from May 2023 to June 2024.A total of 224 T2DM patients(57 vaccinated,167 unvaccinated)were monitored for 1 year.Biomarkers including triglycerides(TGs),high-density lipoprotein(HDL),total cholesterol(TC),pro-staglandins(PGs),and thromboxanes(TXs)were measured at baseline and at 3 months,6 months,9 months,and 1 year post-vaccination.Statistical analyses included Generalized Estimating Equations to assess longitudinal biomarker changes.RESULTS TG and PG levels remained stable across all time points.HDL levels showed a temporary decline at 3 months(mean difference[MD]=-4.33;P<0.001)and 6 months(MD=-2.62;P<0.001)but recovered by 9 months(MD=2.09;P=0.001)and 1 year(MD=2.38;P<0.001).TC exhibited a significant decrease at 3 months(MD=-16.44,P=0.001)before stabilizing.TX levels showed a consistent decline across all follow-ups(e.g.,1 year:MD=-0.08;P=0.036),suggesting a reduced thrombotic risk.Correlation analysis indicated significant interrelations among biomarkers,emphasizing their roles in metabolic and inflammatory pathways.CONCLUSION The J&J COVID-19 vaccine exhibited metabolic safety in patients with T2DM,with transient HDL and TC reductions that later stabilized and a sustained TX decline,suggesting potential cardiovascular benefits.Further studies are needed to explore long-term immunometabolic effects on high-risk populations.
文摘The Moroccan automotive industry is experiencing steady growth,positioning itself as the largest manufacturer of passenger cars in Africa.This expansion is leading to a significant increase in waste generation,particularly from end-of-life vehicles(ELVs),which require proper dismantling and disposal to minimize environmental harm.Millions of tonnes of automotive waste are generated annually,necessitating efficient waste management strategies to mitigate environmental and health risks.ELVs contain hazardous substances such as heavy metals,oils,and plastics,which,if not properly managed,can contaminate soil and water resources.To address this challenge,reverse logistics networks play a crucial role in optimizing the recovery of used components,enhancing recycling efficiency,and ensuring the safe disposal of hazardous and non-recyclable waste.This paper introduces a mathematical programming model designed to minimize the total costs associated with ELVs collection,treatment,and transportation while also accounting for revenues from the resale of repaired,directly reusable,or recycled components.The proposed model determines the optimal locations for processing facilities and establishes efficient material flows within the reverse logistics network.By integrating economic and environmental considerations,this model supports the development of a sustainable and cost-effective automotive waste management system,ultimately contributing to a circular economy approach in the industry.
基金the Ethics Committee of the West China Hospital,Sichuan University(No.2018256)the Animal Ethical and Welfare Committee of Sichuan University in China(No.20211218A).
文摘Objectives:Exosomal long noncoding RNAs(lncRNAs)might facilitate epithelial–mesenchymal transition(EMT)in liver cancer after transarterial chemoembolization(TACE),thereby enhancing tumor cell invasiveness and migration.This study investigated the prognostic role of plasma exosomal long noncoding RNA-plasmacytoma variant translocation 1(lncRNA-PVT1)in TACE treated hepatocellular carcinoma(HCC).Methods:Plasma exosomal lncRNA-PVT1 was evaluated via qPCR before and after TACE.Hepatoma cell behavior was investigated in different HCC cell lines.A lncRNA-PVT1 plasmid was synthesized and overexpressed,and si-lncRNA PVT1 was transfected into poorly invasive cells to reveal its influence on cell characteristics.The lncRNA-PVT1–FoxM1 interaction was elucidated using a double-luciferase reporter gene assay.The effect of miRNA-345-5p on minimally invasive hepatoma cells was assessed.Three experimental groups were established:poorly invasive cells,poorly invasive cells co-cultured with exosomes from hypoxia-induced highly invasive cells,and poorly invasive cells co-cultured with normal hepatocyte exosomes.Liver cancer cells were subcutaneously inoculated into nude mice,with subsequent observations of weight,tumor formation,and tumor size.Results:We identified two lncRNAs(lncRNA-PVT1 and GAPLINC)associated with EMT in the hypoxic microenvironment of liver cancer.Cox multivariate regression analysis was used to establish a prognostic model distinguishing high-and low-risk groups.Hypoxia-induced HepG2 exosomes significantly promoted EMT in poorly invasive HCC cells.LncRNA-PVT1 overexpression and silencing altered E-cadherin,vimentin,and FoxM1 expression,cell proliferation,invasion,migration,and apoptosis.miR-345-5p directly targeted lncRNA-PVT1 and FoxM1,affecting downstream targets.In vivo,co-culturing poorly invasive hepatoma cells with exosomes from highly invasive cells increased tumor volumes,upregulated lncRNA-PVT1,FoxM1,Ki67,and MMP9 expression,and downregulated miR-345-5p expression.Conclusions:Plasma exosomal lncRNA-PVT1 expression is upregulated in highly invasive cells post-hypoxia,potentially serving as a biomarker for evaluating liver cancer prognosis after TACE.Through a miRNA-345-5p-mediated competing endogenous RNA mechanism,it promotes EMT in poorly invasive cells,likely contributing to recurrence and metastasis post-HCC interventional embolization.
基金Supported by National Science Foundation, Tehran
文摘We aimed to evaluate the efficacy of tricyclic antidepressants(TCAs) as a therapeutic option for irritable bowel syndrome(IBS) through meta-analysis of randomized controlled trials.For the years 1966 until September 2008,PubMed,Scopus,Web of Science,and Cochrane Central Register of Controlled Trials were searched for double-blind,placebo-controlled trials investigating the effi cacy of TCAs in the management of IBS.Seven randomized,placebo-controlled clinical trials met our criteria and were included in the metaanalysis.TCAs used in the treatment arm of these trials included amitriptyline,imipramine,desipramine,doxepin and trimipramine.The pooled relative risk for clinical improvement with TCA therapy was 1.93(95% CI:1.44 to 2.6,P<0.0001).Effect size of TCAs versus placebo for mean change in abdominal pain score among the two studies was -44.15(95% CI:-53.27 to -35.04,P<0.0001).It is concluded that low dose TCAs exhibit clinically and statistically signifi cant control of IBS symptoms.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China,No.2016D01C120(to JB)
文摘Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.
文摘We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and all relevant literature were searched from 1965 to June 2009 for any placebo-controlled clinical trials of mebeverine, using search terms such as mebeverine, clinical trials, and IBS. Eight randomized trials met our criteria, including six trials that compared mebeverine with placebo and two that compared mebeverine tablets with capsules. These eight trials included 555 patients randomized to receive either mebeverine or placebo with 352 (63%)women and 203 (37%) men in all subtypes of IBS. The pooled relative risk (RR) for clinical improvement of mebeverine was 1.13 (95% CI: 0.59-2.16, P = 0.7056) and 1.33 (95% CI: 0.92-1.93, P = 0.129) for relief of abdominal pain. The efficacy of mebeverine 200 mg compared to mebeverine 135 mg indicated RRs of 1.12 (95% CI: 0.96-1.3, P = 0.168) for clinical or global improvement and 1.08 (95% CI: 0.87-1.34, P = 0.463) for relief of abdominal pain. Thus, mebeverine is mostly well tolerated with no signif icant adverse effects; however, its eff icacy in global improvement of IBS is not statistically signif icant.
文摘We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis （AP） or chronic pancreatitis （CP） and in the prevention of post-endoscopic retrograde cholangio-pancreatography （post-ERCP） pancreatitis （PEP） up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51334001,51674021,51574021,and 51734003).
文摘In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking process.In the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain operations.In addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 utilization.The results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2.
基金This research was supported by the Natural Science Foundation of Shaanxi (No. 2007C267)National Natural Science Foundation of China (No. 60601026)National 863 Project (No. 2006 AA0224C3)
文摘Objective To study the effect of electromagnetic pulse （EMP） exposure on the permeability of blood-testicle barrier （BTB） in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.
基金financially supported by the National Natu-ral Science Foundation of China (Nos.32171327,21734002,and 51825302)the Natural Science Foundation of Chongqing (No.cstc2021jcyj-cxttX0002).
文摘Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert materials.Thus,repairing or improving the microenvironment of damaged bone tissue is of great significance for bone rescue,reconstruction,and regeneration,which is still a major medical challenge.Oxidative stress(OS)and oxygen(O_(2))deficiency are considered to be specific physiological signals of the bone-injury microenvironment.From the above background,a coating consisting of manganese dioxide(MnO_(2))nanoenzyme and strontium(Sr)ions was fabricated on the surface of the Ti implant via a one-step hydrothermal treatment.MnO_(2) nanoenzyme presented in the coating alleviated OS and O_(2) deficiency at the injury site by catalyzing the decomposition of abundant endogenous H_(2)O_(2) around the modified Ti implants into O_(2).In addition,Sr ions were released from the surface of the implant at a certain rate in a body-fluid environment,further promoting the adhesion,growth,and osteogenic differentiation of mesenchymal stem cells.More importantly,a Sprague Dawley rat femur model demonstrated that the modified Ti implant showed significant potential to accelerate bone tissue reconstruction in vivo.In sum-mary,the present system provides a new idea for the treatment of bone injury and the development of new orthopedic implants.
基金supported by the National Natural Science Foundation of China,No.81070886
文摘Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studied fully.Here,we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular dementia.Eight weeks after model establishment,rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 weeks.Behavioral assessment in the Morris water maze showed that model rats had longer escape latencies in training trials,and spent less time swimming in the target quadrant in probe trials,than sham-operated rats.However,rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model rats.Hematoxylin-eosin and Nissl staining revealed less neuronal necrosis and pathological damage,and more living cells,in the hippocampus of rats treated with tetrandrine than in untreated model rats.Western blot assay showed that interleukin-1β expression,and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472,were lower in model rats that received tetrandrine than in those that did not.The present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression,N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472,and neuronal necrosis.
文摘A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are solved by the integral method which encompasses the Gaussian profiles of velocity and density. The action of waves is incorporated into the equations of motion as an external force and a new exact solution is obtained to predict the trajectory, velocity distribution and boundary thickness of the buoyant jet over an arbitrary lateral cross section. It is found that the velocity along the centerline is inversely proportional to the ratio of the momentum of the wave to the buoyant jet. The averaged bound- ary width varies with the fluctuation of the boundary width, the distance from the orifice and the velocity correction function. Owing to the motion of waves, the fluctuation of the boundary width is proportional to the wave steepness.
基金Project supported by the National Natural Science Foundation of China(Grant No.11176020)
文摘The structural, electronic, and optical properties of cubic perovskite NaMgF3 are calculated by plane-wave pseudopo- tential density functional theory. The calculated lattice constant a0, bulk modulus B0, and the derivative of bulk modulus B~ are 3.872/~, 78.2 GPa, and 3.97, respectively. The results are in good agreement with the available experimental and theo- retical values. The electronic structure shows that cubic NaMgF3 is an indirect insulator with a wide forbidden band gap of Eg = 5.90 eV. The contribution of the different bands is analyzed by total and partial density of states curves. Population analysis of NaMgF3 indicates that there is strong ionic bonding in the MgF2 unit, and a mixture of ionic and weak covalent bonding in the NaF unit. Calculations of dielectric function, absorption coefficient, refractive index, electronic energy loss spectroscopy, optical reflectivity, and conductivity are also performed in the energy range 0 to 70 eV.
基金This research was supported by the Ministry of Science and Technology Grant （2001CB510106）；Science and Technology Plan of Beijing Municipal Government （H020220050290）；National Natural Science Foundation of China Awards for 0utstanding Young Scientists （30125022）；for Creative Research Groups （30421004）；Bill ＆ Melinda Gates Foundation Grant （37871） to H Deng.
文摘The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid （RA） was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin （STZ）-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.
基金Supported by the National Basic Research Program of China under Grant No 2006CB302700, the National High Technology Development Programme of China under Grant No 2006AA03Z360~ Chinese Academy of Sciences （Y2005027）, Science and Technology Council of Shanghai under Grant Nos AM0517, 05JC14076, 0552nm043, 06QA14060, 06XD14025, 0652nm003, and 06DZ22017, the China Postdoctoral Science Foundation, and the K. C. Wong Education Foundation （Hong Kong）.
文摘We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS technology, and the TiOx/TiNx cell array is formed by rf magnetron sputtering and reactive ion etching. In current-voltage （I- V） measurement for current-sweeping mode, large snap-back of voltage is observed, which indicates that the sample changes from high-resistance state （HRS） to low-resistance state （LRS）. In the I-V measurement for voltage-sweeping mode, large current collapse is observed, which indicates that the sample changes from LRS to HRS. The current difference between HRS and LRS is about two orders. The threshold current and voltage for the resistance change is about 5.0- 10^-5 A and 2.5 V, respectively. The pulse voltage can also change the resistance and the pulse time is as shorter as 30 ns for the resistance change. These properties of TiOx/TiNx film are comparable to that of conventional phase-change material, which makes it possible for RRAM application.
基金Project(U1261107)supported by the National Natural Science Foundation of China
文摘Combined with the kinetic model of liquid film spreading, a new numerical method of solid-liquid-gas three-phase flow was developed for the moving of contact line, which was a hybrid method of computational fluid dynamics and lattice Boltzmalm method （LBM）. By taking the effect of molecule force in droplet and the wall surface on liquid film into account, the changing law of contact angle with different surface tensions was analyzed on glass and aluminum foil surfaces. Compared with experimental results, the standard deviation by using LBM is less than 0.5°, which validates the feasibility of LBM simulation on the dynamic process of liquid film spreading. In addition, oscillations are discovered both at the initial and end phases. The phenomenon of retraction is also found and the maximum retraction angle is 7.58°. The obtained result shows that the retraction is proved to be correlative with precursor film by tracking the volume change of liquid film contour. Furthermore, non-dimensional coefficient 2 is introduced to measure the liquid film retraction capacity.
基金The authors would like to express their thanks for the support by the National Natural Science Foundation of China (No.51734003).
文摘Nowadays, in China, the bottom-blowing technique plays an important role in accelerating the molten bath stirring and promoting the metallurgical reactions in electric arc furnace (EAF) steelmaking. The innovations of bottom-blowing technologies in EAF steelmaking were reviewed. The optimized bottom-blowing arrangement in EAF based on the furnace structure and the position of electrodes was introduced, and the fluid flow characteristics of EAF molten bath with bottomblowing were analyzed. Furthermore, bottom-blowing CO2 in EAF can facilitate the carbon-oxygen reaction reaching equilibrium and decrease the content of nitrogen in molten steel due to its special metallurgical properties. Pulsating bottom-blowing in EAF can effectively improve the molten bath stirring through the action of the unsteady bottom blowing gas streams, which could make the fluid flow field more disorderly than the steady bottom-blowing. And submerged O2 injection with CO2 in EAF can noticeably strengthen the EAF molten bath stirring, increase the production efficiency and improve the molten steel quality.
文摘Drimia genus includes plants that used from ancient time for various ailments such as dropsy, respiratory ailment, bone and joint complications,skin disorders, epilepsy and cancer. Toxic properties of some Drimia species also were noted by ancient scientists and these plants have been traditionally used for rat control. Bufadienolides have been identified as the main constituents in the genus of Drimia. Phenolics, sterols, protein and some of other phytochemicals have been also isolated from these plants. Pharmacological and clinical studies have strongly approved their effect on cardiovascular system. Extracts and compounds isolated from Drimia species showed biological activities such as antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory and insecticidal effects throughseveral in vivo and in vitro studies. Moreover, cytotoxic and antitumor activities which may be related to bufadienolide content of these plants have been considered by many researchers. Traditional therapeutic values of these plants for treating respiratory and rheumatic ailments as well as skin disorders are needed to be validated through more researches. Toxic effects of these plants and isolated compounds have been investigated through several in vivo studies. Drimia plants and their isolated compounds have narrow therapeutic index, so patients should be prohibited from applying these plants without medical supervision and should be informed about the main intoxication symptoms before starting treatment. Moreover, interaction of Drimia plants with other constituents of traditional herbal mixtures as well as chemical and biological modalities for reducing toxicity of bufadienolide compounds can be subjected for future studies.
基金the National Natural Science Foundation of China(Grant Nos.51574021 and 51474024)the Fundamental Research Funds for the Central Universities(FRF-TP-19-031A1).
文摘With the importance of the steelmaking industry in the economy and its negative impacts on the environment,reducing dust emissions is a vital focus in this field.Thus,the theory of dust generation in converter steelmaking process was analyzed and the influence of bottom blowing oxygen on dust generation was obtained through experimental research.The industrial test was carried out in a 120-t bottom combined blown O_(2)–CaO steelmaking converter.The results show that lowering the lance position can reduce the amount of dust.This emission rate of the converter is also found to be in direct proportion to the decarburization rate.As a result,the proposed bottom blowing O_(2)–CaO steelmaking converter can technically reduce the amount of dust and improve the recovery rate of iron.With more bottom blowing oxygen,the dust content is lower with the dust peak appearing earlier.The evaporation theory,followed by the bubble theory,plays the primary role in the dust generation of bottom blowing oxygen steelmaking.It points out the direction for the technology research and development of reducing dust generation.
