Objective: To compare the efficacy of acetaminophen, ibuprofen, and prednisone in the treatment of interferon β-1a (IFNβ-1a) flu like syndrome (FLS). Methods: Patients with relapsing remitting multiple sclerosis ini...Objective: To compare the efficacy of acetaminophen, ibuprofen, and prednisone in the treatment of interferon β-1a (IFNβ-1a) flu like syndrome (FLS). Methods: Patients with relapsing remitting multiple sclerosis initiating treatment with IM IFNβ 1a were randomized in a multicenter, randomized, double blind, controlled trial to receive acetaminophen 500 mg before and 6 and 12 hours after each injection, ibuprofen 400 mg before and 6 and 12 hours after each injection, or prednisone 60 mg daily for 1 week, plus tapering. Patients were instructed to keep a daily diary of fever severity, myalgia, chills, headache, and asthenia for 27 days. The sum of the scores of individual symptoms was used to obtain a daily FLS index. The primary outcome was the FLS index area under the curve (AUC) corrected by the number of measurement days. Results: Eighty four patients were randomized at 11 hospitals: acetaminophen (n = 28), ibuprofen (n = 28), and corticosteroids (n = 28). No differences were detected between treatments in the mean AUC of the FLS index. With limitation of the analysis to the days of IM IFNβ 1a injection, differences favoring ibuprofen were observed in the mean FLS index (p = 0.0007). Conclusions: No prophylactic treatment for flu like syndrome seems to be superior to another in terms of overall well being during the first month of IM IFNβ 1a therapy. However, ibuprofen confers better control of symptoms immediately following IM IFNβ 1a injection.展开更多
This paper considers the eventual leader election problem in asynchronous message-passing systems where an arbitrary number t of processes can crash（t〈n,where n is the total number of processes）.It considers weak a...This paper considers the eventual leader election problem in asynchronous message-passing systems where an arbitrary number t of processes can crash（t〈n,where n is the total number of processes）.It considers weak assumptions both on the initial knowledge of the processes and on the network behavior.More precisely,initially,a process knows only its identity and the fact that the process identities are different and totally ordered（it knows neither n nor t）.Two eventual leader election protocols and a lower bound are presented.The first protocol assumes that a process also knows a lower bound α on the number of processes that do not crash.This protocol requires the following behavioral properties from the underlying network：the graph made up of the correct processes and fair lossy links is strongly connected,and there is a correct process connected to（n〈f）-α other correct processes（where f is the actual number of crashes in the considered run） through eventually timely paths（paths made up of correct processes and eventually timely links）.This protocol is not communication-efficient in the sense that each correct process has to send messages forever.The second protocol is communication-efficient：after some time,only the final common leader has to send messages forever.This protocol does not require the processes to know α,but requires stronger properties from the underlying network：each pair of correct processes has to be connected by fair lossy links（one in each direction）,and there is a correct process whose n〈f-1 output links to the rest of correct processes have to be eventually timely.A matching lower bound result shows that any eventual leader election protocol must have runs with this number of eventually timely links,even if all processes know all the processes identities.In addition to being communication-efficient,the second protocol has another noteworthy efficiency property,namely,be the run finite or infinite,all the local variables and message fields have a finite展开更多
Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding prope...Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding property.Microstructures of Cu/Al interfaces were observed by OM,SEM and EDX Analyser in order to investigate the bonding properties of the material.According to the microstructure a series of diffusion layers were observed at the interface and the thicknesses of diffusion layers have increased with aging time as a result of the diffusion bonding.The interfaces were composed of 3-ply diffusion layers and their compositions were changed with aging time at 400 °C.These compositional compounds were revealed to be η2,(θ+η2),(α+θ) intermetallic phases.It is evident from V-notch impact tests that the growth of the brittle diffusion layers with the increasing aging time directly influenced delamination distance between the Cu sleeve and the Al core.It is suggested that the proper holding time at 400 °C for aging as post heat treatment of a drawn Cu/Al bar clad material would be within 1 h.展开更多
Objective:To investigate whether the ethanol extract of Chondracanthus tenellus(Harvey)Hommersand,a type of red algae,could exhibit anti-inflammatory potential in lipopolysaccharide(LPS)-stimulated macrophages.Methods...Objective:To investigate whether the ethanol extract of Chondracanthus tenellus(Harvey)Hommersand,a type of red algae,could exhibit anti-inflammatory potential in lipopolysaccharide(LPS)-stimulated macrophages.Methods:The ethanol extract of Chondracanthus tenellus was applied to 100 ng/mL LPS-stimulated RAW 264.7 cells,and cell viability,phagocytic ability,levels of pro-inflammatory factors,and the production of reactive oxygen species were measured.To identify the underlying mechanism of the ethanol extract of Chondracanthus tenellus,the expression of inflammation-regulated genes was estimated.Results:The ethanol extract of Chondracanthus tenellus had no cytotoxic effect at concentrations below 300μg/mL,and reduced the LPS-induced production of inflammatory mediators including nitric oxide(NO)and prostaglandin E2.Furthermore,the extract markedly suppressed the expression of inducible NO synthase and cyclooxygenase-2,as well as the production of reactive oxygen species.The LPS-induced up-regulation of pro-inflammatory cytokines was attenuated by treatment with the ethanol extract of Chondracanthus tenellus,reducing their extracellular secretion.The Chondracanthus tenellus extract also inhibited LPS-mediated activation of nuclear factor-kappa B(NF-κB).In addition,the phosphorylation of mitogen activated protein kinases(MAPKs)and phosphatidylinositol 3 kinase(PI3K)/Akt was markedly increased by LPS,which was significantly abolished by the Chondracanthus tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.展开更多
Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanol...Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanolic extract on LPS-induced inflammation in RAW264.7 macrophages were assessed using biochemical analysis,including enzyme-linked immunosorbent assay,quantitative reverse transcription-polymerase chain reaction,and Western blot analysis.To examine reactive oxygen species(ROS)production,flow cytometry analysis,and immunofluorescence staining were used.Furthermore,the modulatory effect of C.fulvescens ethanolic extract on NF-κB activation was investigated.Results:C.fulvescens ethanolic extract significantly attenuated LPS-induced levels of pro-inflammatory cytokines and notably reduced the secretion and mRNA levels of LPS-mediated matrix metalloproteinases.In addition,C.fulvescens ethanolic extract decreased ROS production and suppressed the TLR4/NF-κB signaling pathway.Conclusions:C.fulvescens ethanolic extract alleviates inflammation as well as oxidative stress by modulating the TLR4/NF-κB signaling in LPS-induced RAW264.7 macrophages.C.fulvescens can be used as a potential therapeutic agent to suppress inflammation and oxidative stress-associated diseases.展开更多
AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.METHODS: Patients 20 years or older, who u...AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy(SC), and all of the procedures were performed by 11 endoscopists(8 trainees and 3 experts). All procedures were performed with highdefinition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mmlong transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate(PDR), and the number of adenomas and adenoma detection rate(ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon(48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon(35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon(1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon(0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon(46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon(34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC o展开更多
Currently,in the automotive industry,joining of the aluminum alloys with the steel is a crucial problem to be solved.Conventional joining techniques including resistance spot and gas metal arc welding are not acceptab...Currently,in the automotive industry,joining of the aluminum alloys with the steel is a crucial problem to be solved.Conventional joining techniques including resistance spot and gas metal arc welding are not acceptable for those applications due to a number of metallurgical problems.The investigation was carried out to develop the hybrid joining process combining the resistance spot welding and brazing.In this study,an attempt was made to apply hybrid process to the joining of dissimilar sheet metals,Al-Mg-Si（6000 series） alloy and low carbon steel sheet.Hybrid process（resistance spot weld/brazing） using filler metal was found to be effective to overcome the incompatibility between aluminum alloy and steel.Although hybrid joining process of Al alloy sheet and steel sheet did not produce acceptable bond strength,it was proved to have reasonable interfacial bond layer if the optimal process condition was applied.展开更多
This paper proposed a robust adaptive neural network control for an XY table. The XY table composes of two AC servo drives controlled independently. The neural network with radial basis function is employed for veloci...This paper proposed a robust adaptive neural network control for an XY table. The XY table composes of two AC servo drives controlled independently. The neural network with radial basis function is employed for velocity and position tracking control of AC servo drives to improve the system’s dynamic performance and precision. A robust adaptive term is applied to overcome the external disturbances. The stability and the convergence of the system are proved by Lyapunov theory. The proposed controller is implemented in a DSP-based motion board. The validity and robustness of the controller are verified through experimental results.展开更多
Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetr...Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemop展开更多
A strategy for fabricating microcrystalline cellulose–Ti_(3)C_(2)T_(x)(MCC–MXene)nanocomposite films with high relative permittivity,high thermal conductivity,and excellent mechanical properties was developed.The MC...A strategy for fabricating microcrystalline cellulose–Ti_(3)C_(2)T_(x)(MCC–MXene)nanocomposite films with high relative permittivity,high thermal conductivity,and excellent mechanical properties was developed.The MCC–MXene nanocomposite film was fabricated by casting a solution containing N,N-dimethylacetamide/lithium chloride(DMAc/LiCl)-soluble MCC and DMAcdispersible MXene nanosheets,followed by humidity control drying.The MXene nanosheets greatly enhanced the permittivity of the nanocomposite films owing to interfacial polarization.Thus,the nanocomposite film with 20 wt.%MXene content achieved a desirable permittivity of 71.4 at 102 Hz(a 770%improvement against that of neat cellulose),while the dielectric loss only increased by 1.8 times(from 0.39 to 0.70).The obtained nanocomposite films with 20 wt.%and 30 wt.%MXene exhibited remarkable in-plane thermal conductivities of 8.523 and 9.668 W∙m^(−1)∙K^(−1),respectively,owing to the uniform dispersion and selfalignment of the MXene layered structure.Additionally,the uniformly dispersed MXene nanosheets in the MCC network with interfacial interaction(hydrogen bonding)and mechanical entanglement endowed the nanocomposite films with excellent mechanical properties and flexibility.Furthermore,the thermal stability,water resistance,and antibacterial properties of the nanocomposite films were effectively improved with the introduction of MXene.Moreover,using DMAc/LiCl as the solvent system not only improves the compatibility between MCC and MXene but also avoids the problem of easy oxidation of MXene in aqueous systems.With the high stability of the MCC–MXene solution and enhanced properties of the MCC–MXene films,the proposed strategy manifests great potential for fabricating natural biomass-based dielectric materials.展开更多
Objective:To investigate whether ethanol extracts of Chondracanthus tenellus(EECT)could improve immunomodulatory property of murine monocyte/macrophage RAW 264.7 cells.Methods:Cell viability,phagocytic ability,and nit...Objective:To investigate whether ethanol extracts of Chondracanthus tenellus(EECT)could improve immunomodulatory property of murine monocyte/macrophage RAW 264.7 cells.Methods:Cell viability,phagocytic ability,and nitric oxide were measured.The levels of prostaglandin E2 and cytokines were determined using enzyme-linked immunosorbent assay kits.Expression of immunoregulatory response protein was detected by Western blotting assay.Results:As the concentration of EECT increased,the morphology of the cells changed to a typical active macrophage shape,and the phagocytic activity increased significantly.EECT also effectively enhanced the production and secretion of immunomodulatory mediators,such as nitric oxide and prostaglandin E2,and cytokines.In addition,compared with the control group,EECT markedly stimulated the expression of Toll-like receptor 4(TLR4)and myeloid differentiation factor 88,one of the TLR4 adapter molecules.Furthermore,EECT promoted the nucleus translocation of nuclear factor-kappa B(NF-κB)by increasing the phosphorylation and degradation of the inhibitor of NF-κB-α,indicating activation of the NF-κB signaling pathway.Meanwhile,similar trends were found in cells treated with lipopolysaccharide as a positive control.Conclusions:Taken together,the results indicate that EECT has an immunomodulatory effect by increasing the production of immunomodulatory mediators and cytokines through activation of the TLR4/NF-κB signaling pathway.EECT could be used as a potential candidate for medication or dietary supplements to increase immune activity.展开更多
Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone det...Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence （PL） spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at - 395 nm. Among all the films investigated, the film deposited at 250℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300℃ operating temperature.展开更多
Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of ...Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of growth-related genes in zebrafish and MC3T3-E1 cells were assessed using various molecular techniques.Furthermore,the involvement of the mammalian target of rapamycin(mTOR)pathway in AEPB-induced growth was investigated by employing the mTOR inhibitor rapamycin.Results:AEPB administration led to a significant and dose-dependent increase in zebrafish larvae growth over time.Additionally,AEPB treatment upregulated the expression of growth hormone-1(GH-1),insulin-like growth factor-1(IGF-1),growth hormone receptor-1(GHR-1),and cholecystokinin-a(CCKA)in zebrafish.Similarly,AEPB stimulated the expression and release of IGF-1 and accelerated mTOR expression in MC3T3-E1 cells.In addition,rapamycin hindered AEPB-induced linear growth in zebrafish larvae and suppressed the expression of growth-promoting genes by inhibiting mTOR activation.Conclusions:AEPB shows growth-promoting effects by upregulating growth-related genes and activating the mTOR signaling pathway.Further investigations are warranted to elucidate its mechanisms of action and explore its potential application in the development of growth-enhancing supplements for various purposes.展开更多
Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potenti...Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potential of Bacillus sp.PM8313,isolated from wild red sea bream(Pagrus major),through characterization and feeding trials.Results based on in vitro tests showed that PM8313 is safe,confirming its hemolytic,cytotoxic,and antibiotic resistance.In addition,PM8313 showed advantages as a probiotic with high viability in the gastrointestinal model and a high cell adhesion rate.Whole-genome sequencing demonstrated that PM8313 has a 4,615,871 bp single circular chromosome and a guaninecytosine content of 45.25%.It also showed the absence of genes encoding virulence factors,such as cytotoxin,enterotoxin,hemolysin,sphingomyelinase,and phospholipase.In the feeding trial,a supplemental diet of 1×10^(8)CFU/g PM8313 positively altered the weight gain,digestive enzyme activity,and intestinal microbiota composition of red sea bream.Analysis of nonspecific immune parameters and immune-related gene expression,and a challenge test showed that PM8313 supplementation increases immunity and pathogenic bacteria resistance.Our findings suggest that PM8313 should be considered for application as a novel HAP to red sea bream aquaculture.展开更多
This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments ...This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.展开更多
To investigate the effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel, specimens for electron-beam irradiation were prepared from the high Mn-Cr austenitic steel which was solution treate...To investigate the effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel, specimens for electron-beam irradiation were prepared from the high Mn-Cr austenitic steel which was solution treated at 1 373 K for 1 h and aging treated at 573 K for 1 000 h, respectively. The electron-beam irradiation was performed at 573 K up to doses of 5.4 dpa in a 1 250 kV HVEM and irradiation-induced segregation analyses were carried out by an EDX in a 200 kV FE-TEM. The results show that void formation is not observed in both solution treated and aging treated ones. The amount of Cr segregation at the grain boundary decreases in the aged one; however, that of Mn is not changed in solution treated one.展开更多
To satisfy the requirements of motion control for industrial machine, a multi-axis motion controller based on DSP is developed in this paper. The motion controller consists of DSP which plays a main role in this desig...To satisfy the requirements of motion control for industrial machine, a multi-axis motion controller based on DSP is developed in this paper. The motion controller consists of DSP which plays a main role in this design;DPRAM to make sure the rapid and reliable communication with host;FPGA to handle the task of address decoder and receiving feed-back encoder signal;and several peripheral logic circuits. In the part of hardware design, overall structure of motion control system is presented. Then, the Feed-Forward Proportional-Integral-Velocity (FFPIV) scheme which introduces KV in term of velocity loop to achieve the accurate, smooth and real-time response is proposed in the software developing part. The experiment data are carried out to indicate that this motion controller has advantages of superior performance and highly machining precision.展开更多
The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and...The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.展开更多
This paper introduces a PID Autotuning controller using intelligent neural network control based on relay feedback approach. The proposed controller takes advantage of offline learning, in which the initial knowledge ...This paper introduces a PID Autotuning controller using intelligent neural network control based on relay feedback approach. The proposed controller takes advantage of offline learning, in which the initial knowledge of control system is recognized by the relay feedback approach, and the online learning capability of neural network controller helps the control system respond quickly to the dynamics changes. The robustness and motion tracking performance are validated through simulation results.展开更多
Objective:To investigate the effect of honokiol on oxidative damage in HaCaT human keratinocytes.Methods:HaCaT cells were exposed to hydrogen peroxide(H_(2)O_(2)),following pretreatment with various concentrations of ...Objective:To investigate the effect of honokiol on oxidative damage in HaCaT human keratinocytes.Methods:HaCaT cells were exposed to hydrogen peroxide(H_(2)O_(2)),following pretreatment with various concentrations of honokiol.The alleviating effects of honokiol on HaCaT cell viability and cell death,reactive oxygen species(ROS)production,DNA damage,mitochondrial dynamics,and inhibition of adenosine triphoaphate production against H_(2)O_(2)were investigated.Western blotting analysis was used to analyze the expression levels of specific proteins.Results:Honokiol suppressed H_(2)O_(2)-induced cytotoxicity and DNA damage by blocking abnormal ROS accumulation.Honokiol also prevented apoptosis by inhibiting loss of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol,decreasing the Bax/Bcl-2 ratio,and reducing the activity of caspase-3 in H_(2)O_(2)-stimulated HaCaT cells.In addition,honokiol attenuated H_(2)O_(2)-induced reduction of adenosine triphosphate content,and activation of AMP-activated protein kinase(AMPK)was markedly promoted by honokiol in H_(2)O_(2)-stimulated cells.Importantly,the anti-apoptosis and anti-proliferative activity of honokiol against H_(2)O_(2)was further enhanced by adding an activator of AMPK,indicating that honokiol activated AMPK in HaCaT keratinocytes to protect against oxidative damage.Conclusions:The present results indicate that honokiol may be useful as a potential therapeutic agent against various oxidative stress-related skin diseases.展开更多
文摘Objective: To compare the efficacy of acetaminophen, ibuprofen, and prednisone in the treatment of interferon β-1a (IFNβ-1a) flu like syndrome (FLS). Methods: Patients with relapsing remitting multiple sclerosis initiating treatment with IM IFNβ 1a were randomized in a multicenter, randomized, double blind, controlled trial to receive acetaminophen 500 mg before and 6 and 12 hours after each injection, ibuprofen 400 mg before and 6 and 12 hours after each injection, or prednisone 60 mg daily for 1 week, plus tapering. Patients were instructed to keep a daily diary of fever severity, myalgia, chills, headache, and asthenia for 27 days. The sum of the scores of individual symptoms was used to obtain a daily FLS index. The primary outcome was the FLS index area under the curve (AUC) corrected by the number of measurement days. Results: Eighty four patients were randomized at 11 hospitals: acetaminophen (n = 28), ibuprofen (n = 28), and corticosteroids (n = 28). No differences were detected between treatments in the mean AUC of the FLS index. With limitation of the analysis to the days of IM IFNβ 1a injection, differences favoring ibuprofen were observed in the mean FLS index (p = 0.0007). Conclusions: No prophylactic treatment for flu like syndrome seems to be superior to another in terms of overall well being during the first month of IM IFNβ 1a therapy. However, ibuprofen confers better control of symptoms immediately following IM IFNβ 1a injection.
基金supported by the Comunidad de Madrid under Grant No.S2009/TIC-1692the Spanish MEC under Grant Nos.TIN2007-67353-C02-01 and TIN2008-06735-C02-01
文摘This paper considers the eventual leader election problem in asynchronous message-passing systems where an arbitrary number t of processes can crash（t〈n,where n is the total number of processes）.It considers weak assumptions both on the initial knowledge of the processes and on the network behavior.More precisely,initially,a process knows only its identity and the fact that the process identities are different and totally ordered（it knows neither n nor t）.Two eventual leader election protocols and a lower bound are presented.The first protocol assumes that a process also knows a lower bound α on the number of processes that do not crash.This protocol requires the following behavioral properties from the underlying network：the graph made up of the correct processes and fair lossy links is strongly connected,and there is a correct process connected to（n〈f）-α other correct processes（where f is the actual number of crashes in the considered run） through eventually timely paths（paths made up of correct processes and eventually timely links）.This protocol is not communication-efficient in the sense that each correct process has to send messages forever.The second protocol is communication-efficient：after some time,only the final common leader has to send messages forever.This protocol does not require the processes to know α,but requires stronger properties from the underlying network：each pair of correct processes has to be connected by fair lossy links（one in each direction）,and there is a correct process whose n〈f-1 output links to the rest of correct processes have to be eventually timely.A matching lower bound result shows that any eventual leader election protocol must have runs with this number of eventually timely links,even if all processes know all the processes identities.In addition to being communication-efficient,the second protocol has another noteworthy efficiency property,namely,be the run finite or infinite,all the local variables and message fields have a finite
基金Project supported by the Fundamental Materials Development funded by the Korean Ministry of Knowledge Economy
文摘Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding property.Microstructures of Cu/Al interfaces were observed by OM,SEM and EDX Analyser in order to investigate the bonding properties of the material.According to the microstructure a series of diffusion layers were observed at the interface and the thicknesses of diffusion layers have increased with aging time as a result of the diffusion bonding.The interfaces were composed of 3-ply diffusion layers and their compositions were changed with aging time at 400 °C.These compositional compounds were revealed to be η2,(θ+η2),(α+θ) intermetallic phases.It is evident from V-notch impact tests that the growth of the brittle diffusion layers with the increasing aging time directly influenced delamination distance between the Cu sleeve and the Al core.It is suggested that the proper holding time at 400 °C for aging as post heat treatment of a drawn Cu/Al bar clad material would be within 1 h.
基金This research was a part of the project titled‘Omics based on fishery disease control technology development and industrialization(20150242)’,funded by the Ministry of Oceans and Fisheries,Republic of Korea。
文摘Objective:To investigate whether the ethanol extract of Chondracanthus tenellus(Harvey)Hommersand,a type of red algae,could exhibit anti-inflammatory potential in lipopolysaccharide(LPS)-stimulated macrophages.Methods:The ethanol extract of Chondracanthus tenellus was applied to 100 ng/mL LPS-stimulated RAW 264.7 cells,and cell viability,phagocytic ability,levels of pro-inflammatory factors,and the production of reactive oxygen species were measured.To identify the underlying mechanism of the ethanol extract of Chondracanthus tenellus,the expression of inflammation-regulated genes was estimated.Results:The ethanol extract of Chondracanthus tenellus had no cytotoxic effect at concentrations below 300μg/mL,and reduced the LPS-induced production of inflammatory mediators including nitric oxide(NO)and prostaglandin E2.Furthermore,the extract markedly suppressed the expression of inducible NO synthase and cyclooxygenase-2,as well as the production of reactive oxygen species.The LPS-induced up-regulation of pro-inflammatory cytokines was attenuated by treatment with the ethanol extract of Chondracanthus tenellus,reducing their extracellular secretion.The Chondracanthus tenellus extract also inhibited LPS-mediated activation of nuclear factor-kappa B(NF-κB).In addition,the phosphorylation of mitogen activated protein kinases(MAPKs)and phosphatidylinositol 3 kinase(PI3K)/Akt was markedly increased by LPS,which was significantly abolished by the Chondracanthus tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.
基金funded by Korea Institute of Marine Science&Technology Promotion(KIMST)funded by the Ministry of Oceans and Fisheries,Korea(20220488).
文摘Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanolic extract on LPS-induced inflammation in RAW264.7 macrophages were assessed using biochemical analysis,including enzyme-linked immunosorbent assay,quantitative reverse transcription-polymerase chain reaction,and Western blot analysis.To examine reactive oxygen species(ROS)production,flow cytometry analysis,and immunofluorescence staining were used.Furthermore,the modulatory effect of C.fulvescens ethanolic extract on NF-κB activation was investigated.Results:C.fulvescens ethanolic extract significantly attenuated LPS-induced levels of pro-inflammatory cytokines and notably reduced the secretion and mRNA levels of LPS-mediated matrix metalloproteinases.In addition,C.fulvescens ethanolic extract decreased ROS production and suppressed the TLR4/NF-κB signaling pathway.Conclusions:C.fulvescens ethanolic extract alleviates inflammation as well as oxidative stress by modulating the TLR4/NF-κB signaling in LPS-induced RAW264.7 macrophages.C.fulvescens can be used as a potential therapeutic agent to suppress inflammation and oxidative stress-associated diseases.
基金Supported by A 2-year research grant of Pusan National University
文摘AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy(SC), and all of the procedures were performed by 11 endoscopists(8 trainees and 3 experts). All procedures were performed with highdefinition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mmlong transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate(PDR), and the number of adenomas and adenoma detection rate(ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon(48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon(35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon(1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon(0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon(46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon(34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC o
文摘Currently,in the automotive industry,joining of the aluminum alloys with the steel is a crucial problem to be solved.Conventional joining techniques including resistance spot and gas metal arc welding are not acceptable for those applications due to a number of metallurgical problems.The investigation was carried out to develop the hybrid joining process combining the resistance spot welding and brazing.In this study,an attempt was made to apply hybrid process to the joining of dissimilar sheet metals,Al-Mg-Si（6000 series） alloy and low carbon steel sheet.Hybrid process（resistance spot weld/brazing） using filler metal was found to be effective to overcome the incompatibility between aluminum alloy and steel.Although hybrid joining process of Al alloy sheet and steel sheet did not produce acceptable bond strength,it was proved to have reasonable interfacial bond layer if the optimal process condition was applied.
文摘This paper proposed a robust adaptive neural network control for an XY table. The XY table composes of two AC servo drives controlled independently. The neural network with radial basis function is employed for velocity and position tracking control of AC servo drives to improve the system’s dynamic performance and precision. A robust adaptive term is applied to overcome the external disturbances. The stability and the convergence of the system are proved by Lyapunov theory. The proposed controller is implemented in a DSP-based motion board. The validity and robustness of the controller are verified through experimental results.
基金a part of the project titled‘Omics based on fishery disease control technology development and industrialization(20150242)’‘Development of functional food products with natural materials derived from marine resources(2017-0377)’funded by the Ministry of Oceans and Fisheries,Republic of Korea.
文摘Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemop
基金supported by the National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science and ICT,Korea(NRF-2021R1I1A3060098,NRF-2021R1I1A3059777)supported by the Brain Korea 21 Plus Program(4199990414196)+1 种基金the Korea Institute for Advancement of Technology funded by the Ministry of Trade,Industry and Energy(P0017531)Y.Z.Y.was partially supported by the China Scholarship Council(No.201908260073).
文摘A strategy for fabricating microcrystalline cellulose–Ti_(3)C_(2)T_(x)(MCC–MXene)nanocomposite films with high relative permittivity,high thermal conductivity,and excellent mechanical properties was developed.The MCC–MXene nanocomposite film was fabricated by casting a solution containing N,N-dimethylacetamide/lithium chloride(DMAc/LiCl)-soluble MCC and DMAcdispersible MXene nanosheets,followed by humidity control drying.The MXene nanosheets greatly enhanced the permittivity of the nanocomposite films owing to interfacial polarization.Thus,the nanocomposite film with 20 wt.%MXene content achieved a desirable permittivity of 71.4 at 102 Hz(a 770%improvement against that of neat cellulose),while the dielectric loss only increased by 1.8 times(from 0.39 to 0.70).The obtained nanocomposite films with 20 wt.%and 30 wt.%MXene exhibited remarkable in-plane thermal conductivities of 8.523 and 9.668 W∙m^(−1)∙K^(−1),respectively,owing to the uniform dispersion and selfalignment of the MXene layered structure.Additionally,the uniformly dispersed MXene nanosheets in the MCC network with interfacial interaction(hydrogen bonding)and mechanical entanglement endowed the nanocomposite films with excellent mechanical properties and flexibility.Furthermore,the thermal stability,water resistance,and antibacterial properties of the nanocomposite films were effectively improved with the introduction of MXene.Moreover,using DMAc/LiCl as the solvent system not only improves the compatibility between MCC and MXene but also avoids the problem of easy oxidation of MXene in aqueous systems.With the high stability of the MCC–MXene solution and enhanced properties of the MCC–MXene films,the proposed strategy manifests great potential for fabricating natural biomass-based dielectric materials.
基金This research was a part of the project titled‘Omics based on fishery disease control technology development and industrialization(20150242)’funded by the Ministry of Oceans and Fisheries,Republic of Korea.
文摘Objective:To investigate whether ethanol extracts of Chondracanthus tenellus(EECT)could improve immunomodulatory property of murine monocyte/macrophage RAW 264.7 cells.Methods:Cell viability,phagocytic ability,and nitric oxide were measured.The levels of prostaglandin E2 and cytokines were determined using enzyme-linked immunosorbent assay kits.Expression of immunoregulatory response protein was detected by Western blotting assay.Results:As the concentration of EECT increased,the morphology of the cells changed to a typical active macrophage shape,and the phagocytic activity increased significantly.EECT also effectively enhanced the production and secretion of immunomodulatory mediators,such as nitric oxide and prostaglandin E2,and cytokines.In addition,compared with the control group,EECT markedly stimulated the expression of Toll-like receptor 4(TLR4)and myeloid differentiation factor 88,one of the TLR4 adapter molecules.Furthermore,EECT promoted the nucleus translocation of nuclear factor-kappa B(NF-κB)by increasing the phosphorylation and degradation of the inhibitor of NF-κB-α,indicating activation of the NF-κB signaling pathway.Meanwhile,similar trends were found in cells treated with lipopolysaccharide as a positive control.Conclusions:Taken together,the results indicate that EECT has an immunomodulatory effect by increasing the production of immunomodulatory mediators and cytokines through activation of the TLR4/NF-κB signaling pathway.EECT could be used as a potential candidate for medication or dietary supplements to increase immune activity.
基金Project supported by the Dong-Eui University Grant(No.2014AA342)
文摘Zinc oxide （ZnO） thin films were prepared onto glass substrates at moderately low growth tempera- ture by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence （PL） spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at - 395 nm. Among all the films investigated, the film deposited at 250℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300℃ operating temperature.
基金supported by the 2023 scientific promotion program funded by Jeju National University.
文摘Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of growth-related genes in zebrafish and MC3T3-E1 cells were assessed using various molecular techniques.Furthermore,the involvement of the mammalian target of rapamycin(mTOR)pathway in AEPB-induced growth was investigated by employing the mTOR inhibitor rapamycin.Results:AEPB administration led to a significant and dose-dependent increase in zebrafish larvae growth over time.Additionally,AEPB treatment upregulated the expression of growth hormone-1(GH-1),insulin-like growth factor-1(IGF-1),growth hormone receptor-1(GHR-1),and cholecystokinin-a(CCKA)in zebrafish.Similarly,AEPB stimulated the expression and release of IGF-1 and accelerated mTOR expression in MC3T3-E1 cells.In addition,rapamycin hindered AEPB-induced linear growth in zebrafish larvae and suppressed the expression of growth-promoting genes by inhibiting mTOR activation.Conclusions:AEPB shows growth-promoting effects by upregulating growth-related genes and activating the mTOR signaling pathway.Further investigations are warranted to elucidate its mechanisms of action and explore its potential application in the development of growth-enhancing supplements for various purposes.
基金financially supported by the grant (R2022016) from the National Institute of Fisheries Science,Republic of Koreathe National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2022R1A2C1012655).
文摘Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potential of Bacillus sp.PM8313,isolated from wild red sea bream(Pagrus major),through characterization and feeding trials.Results based on in vitro tests showed that PM8313 is safe,confirming its hemolytic,cytotoxic,and antibiotic resistance.In addition,PM8313 showed advantages as a probiotic with high viability in the gastrointestinal model and a high cell adhesion rate.Whole-genome sequencing demonstrated that PM8313 has a 4,615,871 bp single circular chromosome and a guaninecytosine content of 45.25%.It also showed the absence of genes encoding virulence factors,such as cytotoxin,enterotoxin,hemolysin,sphingomyelinase,and phospholipase.In the feeding trial,a supplemental diet of 1×10^(8)CFU/g PM8313 positively altered the weight gain,digestive enzyme activity,and intestinal microbiota composition of red sea bream.Analysis of nonspecific immune parameters and immune-related gene expression,and a challenge test showed that PM8313 supplementation increases immunity and pathogenic bacteria resistance.Our findings suggest that PM8313 should be considered for application as a novel HAP to red sea bream aquaculture.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(No.2017R1A5A1014883).
文摘This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.
文摘To investigate the effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel, specimens for electron-beam irradiation were prepared from the high Mn-Cr austenitic steel which was solution treated at 1 373 K for 1 h and aging treated at 573 K for 1 000 h, respectively. The electron-beam irradiation was performed at 573 K up to doses of 5.4 dpa in a 1 250 kV HVEM and irradiation-induced segregation analyses were carried out by an EDX in a 200 kV FE-TEM. The results show that void formation is not observed in both solution treated and aging treated ones. The amount of Cr segregation at the grain boundary decreases in the aged one; however, that of Mn is not changed in solution treated one.
文摘To satisfy the requirements of motion control for industrial machine, a multi-axis motion controller based on DSP is developed in this paper. The motion controller consists of DSP which plays a main role in this design;DPRAM to make sure the rapid and reliable communication with host;FPGA to handle the task of address decoder and receiving feed-back encoder signal;and several peripheral logic circuits. In the part of hardware design, overall structure of motion control system is presented. Then, the Feed-Forward Proportional-Integral-Velocity (FFPIV) scheme which introduces KV in term of velocity loop to achieve the accurate, smooth and real-time response is proposed in the software developing part. The experiment data are carried out to indicate that this motion controller has advantages of superior performance and highly machining precision.
基金supported by the project of Fundamental Materials Development funded by the Korean Ministry of Knowledge Economy
文摘The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.
文摘This paper introduces a PID Autotuning controller using intelligent neural network control based on relay feedback approach. The proposed controller takes advantage of offline learning, in which the initial knowledge of control system is recognized by the relay feedback approach, and the online learning capability of neural network controller helps the control system respond quickly to the dynamics changes. The robustness and motion tracking performance are validated through simulation results.
文摘Objective:To investigate the effect of honokiol on oxidative damage in HaCaT human keratinocytes.Methods:HaCaT cells were exposed to hydrogen peroxide(H_(2)O_(2)),following pretreatment with various concentrations of honokiol.The alleviating effects of honokiol on HaCaT cell viability and cell death,reactive oxygen species(ROS)production,DNA damage,mitochondrial dynamics,and inhibition of adenosine triphoaphate production against H_(2)O_(2)were investigated.Western blotting analysis was used to analyze the expression levels of specific proteins.Results:Honokiol suppressed H_(2)O_(2)-induced cytotoxicity and DNA damage by blocking abnormal ROS accumulation.Honokiol also prevented apoptosis by inhibiting loss of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol,decreasing the Bax/Bcl-2 ratio,and reducing the activity of caspase-3 in H_(2)O_(2)-stimulated HaCaT cells.In addition,honokiol attenuated H_(2)O_(2)-induced reduction of adenosine triphosphate content,and activation of AMP-activated protein kinase(AMPK)was markedly promoted by honokiol in H_(2)O_(2)-stimulated cells.Importantly,the anti-apoptosis and anti-proliferative activity of honokiol against H_(2)O_(2)was further enhanced by adding an activator of AMPK,indicating that honokiol activated AMPK in HaCaT keratinocytes to protect against oxidative damage.Conclusions:The present results indicate that honokiol may be useful as a potential therapeutic agent against various oxidative stress-related skin diseases.
