Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to impr...Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.展开更多
BACKGROUND Stromal cell derived factor-1(SDF-1)plays a pivotal role in the recruitment of stem cells to injured livers.However,the changes of SDF-l in patients with hepatitis B virus(HBV)-related acute-on-chronic live...BACKGROUND Stromal cell derived factor-1(SDF-1)plays a pivotal role in the recruitment of stem cells to injured livers.However,the changes of SDF-l in patients with hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF)have yet to be elucidated.AIM To study the SDF-1 changes in patients with HBV-related ACLF.METHODS 30 patients with HBV-related ACLF,27 patients with chronic hepatitis B and 20 healthy individuals are involved in our study.The SDF-l mRNA expression in liver tissue was detected by quantitative real-time polymerase chain reaction.Immunohistochemical staining was performed to illustrate the expression of SDFl,CXC receptor 4(CXCR4)and Ki67.The serum SDF-l concentrations were also detected by enzyme-linked immunosorbent assays.RESULTS The expression of SDF-1 mRNA from ACLF patients was remarkably higher than that from other patients(both P<0.05).The expression of SDF-l,CXCR4 and Ki67 from ACLF were the highest among the three groups(all P<0.01).The serum SDF-l levels in ACLF patients were significantly lower than that in other patients(both P<0.01).Moreover,in ACLF patients,the serum SDF-1 Levels were positively correlated with serum total bilirubin and international normalized ratio.In addition,the serum SDF-l levels in survival were significantly lower compared with the non-survivals(P<0.05).The area under the curve for the serum SDF-1 level in predicting 28-d mortality was 0.722(P<0.05).CONCLUSION This study provides the SDF-1 changes in patients with HBV-related ACLF.The SDF-1 Level at admission may serve as a promising prognostic marker for predicting short-term prognosis.展开更多
Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ische...Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.展开更多
[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived f...[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.展开更多
Broadband electromagnetic(EM)wave absorption materials play an important role in military stealth and health protection.Herein,metal–organic frameworks(MOFs)-derived magnetic-carbon CoNiM@C(M=Cu,Zn,Fe,Mn)microspheres...Broadband electromagnetic(EM)wave absorption materials play an important role in military stealth and health protection.Herein,metal–organic frameworks(MOFs)-derived magnetic-carbon CoNiM@C(M=Cu,Zn,Fe,Mn)microspheres are fabricated,which exhibit flower-like nano–microstructure with tunable EM response capacity.Based on the MOFs-derived CoNi@C microsphere,the adjacent third element is introduced into magnetic CoNi alloy to enhance EM wave absorption performance.In term of broadband absorption,the order of efficient absorption bandwidth(EAB)value is Mn>Fe=Zn>Cu in the CoNiM@C microspheres.Therefore,MOFs-derived flower-like CoNiMn@C microspheres hold outstanding broadband absorption and the EAB can reach up to 5.8 GHz(covering 12.2–18 GHz at 2.0 mm thickness).Besides,off-axis electron holography and computational simulations are applied to elucidate the inherent dielectric dissipation and magnetic loss.Rich heterointerfaces in CoNiMn@C promote the aggregation of the negative/positive charges at the contacting region,forming interfacial polarization.The graphitized carbon layer catalyzed by the magnetic CoNiMn core offered the electron mobility path,boosting the conductive loss.Equally importantly,magnetic coupling is observed in the CoNiMn@C to strengthen the magnetic responding behaviors.This study provides a new guide to build broadband EM absorption by regulating the ternary magnetic alloy.展开更多
BACKGROUND Osteoarthritis(OA)is the most common joint disorder,is associated with an increasing socioeconomic impact owing to the ageing population.AIM To analyze and compare the efficacy and safety of bone-marrow-der...BACKGROUND Osteoarthritis(OA)is the most common joint disorder,is associated with an increasing socioeconomic impact owing to the ageing population.AIM To analyze and compare the efficacy and safety of bone-marrow-derived mesenchymal stromal cells(BM-MSCs)and adipose tissue-derived MSCs(AD-MSCs)in knee OA management from published randomized controlled trials(RCTs).METHODS Independent and duplicate electronic database searches were performed,including PubMed,EMBASE,Web of Science,and Cochrane Library,until August 2021 for RCTs that analyzed the efficacy and safety of AD-MSCs and BM-MSCs in the management of knee OA.The visual analog scale(VAS)score for pain,Western Ontario McMaster Universities Osteoarthritis Index(WOMAC),Lysholm score,Tegner score,magnetic resonance observation of cartilage repair tissue score,knee osteoarthritis outcome score(KOOS),and adverse events were analyzed.Analysis was performed on the R-platform using OpenMeta(Analyst)software.Twenty-one studies,involving 936 patients,were included.Only one study compared the two MSC sources without patient randomization;hence,the results of all included studies from both sources were pooled,and a comparative critical analysis was performed.RESULTS At six months,both AD-MSCs and BM-MSCs showed significant VAS improvement(P=0.015,P=0.012);this was inconsistent at 1 year for BM-MSCs(P<0.001,P=0.539),and AD-MSCs outperformed BM-MSCs compared to controls in measures such as WOMAC(P<0.001,P=0.541),Lysholm scores(P=0.006;P=0.933),and KOOS(P=0.002;P=0.012).BM-MSC-related procedures caused significant adverse events(P=0.003)compared to AD-MSCs(P=0.673).CONCLUSION Adipose tissue is superior to bone marrow because of its safety and consistent efficacy in improving pain and functional outcomes.Future trials are urgently warranted to validate our findings and reach a consensus on the ideal source of MSCs for managing knee OA.展开更多
Herein,Pd nanoparticles loaded Co_(3)O_(4)catalysts(Pd@Co_(3)O_(4))are constructed from zeolitic imidazolate framework-67(ZIF-67)for the ethanol oxidation reaction(EOR).It is demonstrated for the first time that the e...Herein,Pd nanoparticles loaded Co_(3)O_(4)catalysts(Pd@Co_(3)O_(4))are constructed from zeolitic imidazolate framework-67(ZIF-67)for the ethanol oxidation reaction(EOR).It is demonstrated for the first time that the electrochemical conversion of Co_(3)O_(4)support would result in the charge distribution alignment at the Pd/Co_(3)O_(4)interface and induce the formation of highly reactive Pd-O species(PdO^(*)),which can further catalyze the consequent reactions of the intermediates of the ethanol oxidation.The catalyst,Pd@Co_(3)O_(4)-450,obtained under the optimized conditions exhibits excellent EOR performance with a high mass activity of 590 mA mg-1,prominent operational stability,and extraordinary capability for the electro-oxidation of acetaldehyde intermediates.Importantly,the detailed mechanism investigation reveals that Pd@Co_(3)O_(4)-450 could be benefit to the C-C bond cleavage to promote the desirable C1 pathway for the ethanol oxidation reaction.The present strategy based on the metal-support interaction of the catalyst might provide valuable inspiration for the design of high-performing catalysts for the ethanol oxidation reaction.展开更多
Background and Aims: Androgenetic alopecia (AGA) is a common form of hair loss in both men and women. Despite its high prevalence and associated patient morbidity, the approved therapeutic options are limited to finas...Background and Aims: Androgenetic alopecia (AGA) is a common form of hair loss in both men and women. Despite its high prevalence and associated patient morbidity, the approved therapeutic options are limited to finasteride and minoxidil. The present study is aimed at assessing the efficacy of hair serum formulation, Trichosera<sup>®</sup>containing Bone marrow-derived mesenchymal stromal cells conditioned media as an active ingredient, for hair fall control and hair regrowth in healthy Indian human volunteers. Methods: The product was made using a 20% concentration of 10X Conditioned Media along with excipients. The final product was tested for physicochemical parameters, biomarkers, total protein content and microbial limits as per our in-house specifications. Results: The primary irritation patch test showed that the product is non-irritant and dermatologically safe. A clinical study on 40 subjects was conducted to evaluate the effectiveness of the bioactive formulation in hair fall control and hair regrowth in healthy volunteers. Phototrichogram measurement showed hair density and hair growth rate increased significantly by 11.54% and 18.66% at week 24. Hair tensile strength also increased significantly by 41.10% at 12 weeks follow-up. Hair pull test, to see a reduction in pulled hair and comb’s test to show a decrease in hair fall significantly improved from week 4 onwards. There were no significant adverse events in response to the product application. Conclusion: It is concluded that the hair serum product is completely safe on direct application to the scalp and showed significant improvement in the hair growth rate, hair density, scalp condition and reduction in hair fall. .展开更多
Electrochemical reduction of Bi-based metal oxides is regarded as an effective strategy to rationally design advanced electrocatalysts for electrochemical CO_(2)reduction reaction(CO_(2)RR).Realizing high selectivity ...Electrochemical reduction of Bi-based metal oxides is regarded as an effective strategy to rationally design advanced electrocatalysts for electrochemical CO_(2)reduction reaction(CO_(2)RR).Realizing high selectivity at high current density is important for formate production,but remains challenging.Herein,the BiIn hybrid electrocatalyst,deriving from the Bi2O3/In2O3heterojunction(MOD-Biln),shows excellent catalytic performance for CO_(2)RR.The Faradaic efficiency of formate(FEHCOO-) can be realized over 90% at a wide potential window from-0.4 to-1.4 V vs.RHE,while the partial current density of formate(jHCOO-) reaches about 136.7 mA cm^(-2)at-1.4 V in flow cell without IR-compensation.In additio n,the MOD-Biln exhibits superior stability with high selectivity of formate at 100 mA cm^(-2).Systematic characterizations prove the optimized catalytic sites and interface charge transfer of MOD-Biln,while theoretical calculation confirms that the hybrid structure with dual Bi/In metal sites contribute to the optimal free energy of*H and*OCHO intermediates on MOD-Biln surface,thus accelerating the formation and desorption step of*HCOOH to final formate production.Our work provides a facile and useful strategy to develop highly-active and stable electrocatalysts for CO_(2)RR.展开更多
2D MXenes are highly attractive for fabricating high-precision gas sensors operated at room temperature(RT)due to their high surface-to-volume ratio.However,the limited selectivity and low sensitivity are still long-s...2D MXenes are highly attractive for fabricating high-precision gas sensors operated at room temperature(RT)due to their high surface-to-volume ratio.However,the limited selectivity and low sensitivity are still long-standing challenges for their further applications.Herein,the self-assembly of 0D-2D heterostructure for highly sensitive NO_(2) detection was achieved by integrating ZnO nanoparticles on Ti_(3)C_(2)Tx MXene-derived TiO_(2) nanosheets(designated as ZnO@MTiO_(2)).ZnO nanoparticles can not only act as spacers to prevent the restacking of MTiO_(2) nanosheets and ensure effective transfer for gas molecules,but also enhance the sensitivity of the sensor the through trapping effect on electrons.Meanwhile,MTiO_(2) nanosheets facilitate gas diffusion for rapid sensor response.Benefiting from the synergistic effect of individual components,the ZnO@MTiO_(2)0D-2D heterostructure-based sensors revealed remarkable sensitivity and excellent selectivity to low concentration NO_(2) at RT.This work may facilitate the sensing application of MXene derivative and provide a new avenue for the development of high-performance gas sensors in safety assurance and environmental monitoring.展开更多
Rechargeable aprotic Li-O_(2)batteries have attractea increasing attention due to their extremely high capacity,and it is very important to design appropriate strategies to synthesize efficient catalysts used as oxyge...Rechargeable aprotic Li-O_(2)batteries have attractea increasing attention due to their extremely high capacity,and it is very important to design appropriate strategies to synthesize efficient catalysts used as oxygen cathode.In present work,we present an expedient "instantaneous nucleation and epitaxial growth"(INEG) synthesis strategy for convenient and large-scale synthesis of ultrafine MOCPs nanoparticles(size 50-100 nm) with obvious advantages such as fast synthesis,high yields,low costs and reduced synthetic steps.The bimetallic Ru/Co-MOCPs are further pyrolyzed to obtain bimetallic Coand low content of Ru-based nanoparticles embedded within nitrogen-doped carbon(Ru/Co@N-C) as an efficient catalyst used in Li-O_(2)battery.The Ru/Co@N-C provides porous carbon framework for the ion transportation and O_(2)diffusion,and has large amounts of metal/nonmetal sites as active site to promote the oxygen reduction reaction(ORR)/oxygen evolution reaction(OER) in Li-O_(2)batteries.As a consequence,a high discharge specific capacity of 15246 mA h g^(-1)at 250 mA g^(-1), excellent rate capability at different current densities,and stable overpotential during cycling,are achieved.This work opened up a new understanding for the industrialized synthesis of ultrafine catalysts for Li-O_(2)batteries with excellent structural characteristics and electrochemical performance.展开更多
Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was pr...Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was prepared by solvothermal method,and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis.The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared.The experimental results showed that when the metal molar ratio was Fe:Ni=1:5 and the pyrolysis temperature was 450℃,the sample(FeNi_(5)-MOF-450)exhibits a composite structure of Ni Fe_(2)O_(4)/FeNi_(3)/C and owns the superior electrocatalytic activity in OER.When the current density is 100 mA·cm^(-2),the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec^(-1),which indicates that FeNi_(5)-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO_(2).Moreover,the long-term stability of FeNi_(5)-MOF-450 further promotes its development in OER.This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.展开更多
Background:This study aimed to select compounds with unique inhibitory effects on muscle-invasive bladder cancer(MIBC)from coumarone derivatives with similar parent nuclear structures and to reveal their tumor-suppres...Background:This study aimed to select compounds with unique inhibitory effects on muscle-invasive bladder cancer(MIBC)from coumarone derivatives with similar parent nuclear structures and to reveal their tumor-suppressive effects using various approaches.Methods:Bladder cancer cell lines SW780 and T24,as well as human normal bladder epithelial cell line SV-HUC-1 were selected as the study model,and these urinary system cells were co-incubated with various concentrations of(S,E)-4-(4-methylbenzylidene)-3-phenylchroman-3-ol,(S,E)-4-(4-isocyanobenzylidene)-3-phenylchroman-3-ol,(S,E)-4-(4-fluorobenzylidene)-3-phenylchroman-3-ol(FPO),and(S,E)-3-phenyl-4-(4-(trifluoromethoxy)benzylidene)chroman-3-ol.Cell activity was detected using cell counting kit-8.FPO showed the strongest inhibitory effect on MIBC cells;therefore,it was selected for further experiments.We monitored the FPO-induced T24 cell morphological changes with an inverted microscope.The FPO-inhibited migration of T24 cells was examined using a cell scratch assay.We detected the clonogenic ability of T24 cells through a clone formation test and evaluated their proliferative ability using a 5-ethynyl-2’-deoxyuridine fluorescence staining kit.The inhibitory effect of FPO against the cell cycle was monitored using flow cytometry,and its suppressive effect on the DNA replication ability of T24 cells was detected using double fluorescence staining(Ki67 and phalloidin).Results:Among the four candidate coumarone derivatives,FPO showed the most significant inhibitory effect on MIBC cells and was less toxic to normal urothelial cells.FPO inhibited T24 cell growth in time and dose-dependent manners(the half-inhibitory concentration is 8μM).FPO significantly repressed the proliferation,migration,and clonogenic ability of bladder cancer T24 cells.Cell mobility was significantly inhibited by FPO:30μM FPO almost completely repressed migration occurred at after 24 h treatment.Moreover,FPO significantly suppressed the clonogenicity of bladder cancer cells in a dose-dependent manner.Mechanistically,FPO targeted the cell cycle,arresting the S and G2 phases on bladder cancer T24 cells.Conclusion:We discovered a novel anticancer chemical,FPO,and proposed a potential mechanism,through which it suppresses MIBC T24 cells by repressing the cell cycle in the S and G2 phases.This study contributes to the development of novel anticancer drugs for MIBC.展开更多
β-SiC ceramic powders were obtained by pyrolyzing polycarbosilane in vacuum at 800-1200 °C. The β-SiC ceramic powders were characterized by TGA/DSC, XRD and Raman spectroscopy. The dielectric properties of β-S...β-SiC ceramic powders were obtained by pyrolyzing polycarbosilane in vacuum at 800-1200 °C. The β-SiC ceramic powders were characterized by TGA/DSC, XRD and Raman spectroscopy. The dielectric properties of β-SiC ceramic powders were investigated by measuring their complex permittivity by rectangle wave guide method in the frequency range of 8.2-18 GHz. The results show that both real part ε′ and imaginary part ε″ of complex permittivity increase with increasing pyrolysis temperature. The mechanism was proposed that order carbon formed at high temperature resulted in electron relaxation polarization and conductance loss, which contributes to the increase in complex permittivity.展开更多
A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel (RDF). The CaO dechlorination model obtained by the thermal g...A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel (RDF). The CaO dechlorination model obtained by the thermal gravity analysis (TGA) is coupled to investigate the process of CaO dechlorination. An Eulerian-Eulerian method is adopted to simulate the gas-solid flow and self-developed chemical reaction modules are used to simulate chemical reactions. Flow patterns, gasification results and dechlorination efficiency are obtained by numerical simulation. Meanwhile, simulations are performed to evaluate the effects of Ca/Cl molar ratio and temperature on dechlorination efficiency. The simulation results show that the presence of bubbles in the gasifier lowers the CaO dechlorination efficiency. Increasing the Ca/Cl molar ratio can enhance the dechlorination efficiency. However, with the temperature increasing, the dechlorination efficiency increases initially and then decreases. The optimal Ca/Cl molar ratio is in the range of 3. 0 to 3. 5 and the optimal temperature is 923K.展开更多
In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MED...In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MEDO,and achieves the automatic adjustment of the parameters.The proposed method is named as adaptive Maxwell’s equations derived optimization(AMEDO).In order to evaluate the performance of AMEDO,eight benchmarks are used and the results are compared with the original MEDO method.The results show that AMEDO can greatly reduce the workload of manual adjustment of parameters,and at the same time can keep the accuracy and stability.Moreover,the convergence of the optimization can be accelerated due to the dynamical adjustment of the parameters.In the end,the proposed AMEDO is applied to the side lobe level suppression and array failure correction of a linear antenna array,and shows great potential in antenna array synthesis.展开更多
Factor properties and their structures are important themes in combinatorics on words.Let D be the infinite one-sided sequence over the alphabet{a,b}generated by the period-doubling substitutionσ(a)=ab andσ(b)=aa.In...Factor properties and their structures are important themes in combinatorics on words.Let D be the infinite one-sided sequence over the alphabet{a,b}generated by the period-doubling substitutionσ(a)=ab andσ(b)=aa.In this paper,we determine the derived sequence D_(ω)(D)for any factorω■D,and study some factor spectra using the structures of derived sequences.We also prove the reflexivity property of derived sequences.展开更多
OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression o...OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression of transduced gene by X-gal staining was examined. Then plasmid pcDNA3-rhBMP7 was delivered to cultured BMSCs. Through immunohistochemical staining and RT-PCR assay, the expression of rhBMP7 gene was detected. RESULTS: The exogenous gene could be expressed efficiently in transduced BMSCs. CONCLUSION: The present study provided a theoretical basis to gene therapy on the problems of bone and cartilage tissue.展开更多
Fundamental units of measurements are kilograms, meters, and seconds—in regards to mass length, and time. All other measurements in mechanical quantities including kinetic quantities and dynamic quantities are called...Fundamental units of measurements are kilograms, meters, and seconds—in regards to mass length, and time. All other measurements in mechanical quantities including kinetic quantities and dynamic quantities are called derived units. These derived units can be expressed in terms of fundamental units, such as acceleration, area, energy, force, power, velocity and volume. Derived quantities will be referred to as time, length, and mass. In order to explain that fundamental units are not equivalent with fundamental quantities, we need to understand the contraction of time and length in Special Relativity. If we choose the velocity of light as fundamental quantity and length and time as derived quantities, then we are able to construct three-dimensional space-time frames. Three-dimensional space-time frames representing time with polar coordination, time contraction and length contraction can be shown graphically.展开更多
BACKGROUND: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin., an anthraquinone d...BACKGROUND: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin., an anthraquinone derivative from Radix et Rhizoma Rhei, and baicalein, a flavone from Scutellaria baicalensis Georgi, both have been reported to possess anti-inflammatory activities. The expression pattern of SDF-1 in experimental acute pancreatitis (AP) and the effect of emodin or baicalein on that are not well defined. The present study aimed to investigate the effects of emodin and baicalein on pancreatic myeloperoxidase (MPO) activity (reflecting leukocyte sequestration) and cytokine production, as well as tissue SDF-1 expression in the setting of AP. METHODS: A :rat model of AP was induced by administration (of 5% sodium taurocholate through the biliopancreatic duct. The level of tumor necrosis factor-a (TNF-alpha), interleukin-6 (IL-6) and MPO in the pancreas, and serum amylase were tested by immunohistochemistry, ELISA and chromatometry. The expressions of SDF-1 alpha and SDF-1 beta were detected by real-time PCR, Western blotting, and immunohistochemistry. RESULT: Combination of emodin and baicalein significantly reduced pancreatic TNIP-alpha, IL-6 and MPO, and also inhibited pancreatic SDF-1 expression. CONCLUSIONS: The inhibition of SDF-1 expression by emodin and baicalein might contribute, in part at least, to the amelioration of pancreatic inflammation. The present study also shows benefits of simultaneous treatment of AP.展开更多
基金supported by the Natural Science Fund of Fujian Province,No.2020J011058(to JK)the Project of Fujian Provincial Hospital for High-level Hospital Construction,No.2020HSJJ12(to JK)+1 种基金the Fujian Provincial Finance Department Special Fund,No.(2021)848(to FC)the Fujian Provincial Major Scientific and Technological Special Projects on Health,No.2022ZD01008(to FC).
文摘Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.
基金Science and Technology Project of Hengshui,No.2019014061Z.
文摘BACKGROUND Stromal cell derived factor-1(SDF-1)plays a pivotal role in the recruitment of stem cells to injured livers.However,the changes of SDF-l in patients with hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF)have yet to be elucidated.AIM To study the SDF-1 changes in patients with HBV-related ACLF.METHODS 30 patients with HBV-related ACLF,27 patients with chronic hepatitis B and 20 healthy individuals are involved in our study.The SDF-l mRNA expression in liver tissue was detected by quantitative real-time polymerase chain reaction.Immunohistochemical staining was performed to illustrate the expression of SDFl,CXC receptor 4(CXCR4)and Ki67.The serum SDF-l concentrations were also detected by enzyme-linked immunosorbent assays.RESULTS The expression of SDF-1 mRNA from ACLF patients was remarkably higher than that from other patients(both P<0.05).The expression of SDF-l,CXCR4 and Ki67 from ACLF were the highest among the three groups(all P<0.01).The serum SDF-l levels in ACLF patients were significantly lower than that in other patients(both P<0.01).Moreover,in ACLF patients,the serum SDF-1 Levels were positively correlated with serum total bilirubin and international normalized ratio.In addition,the serum SDF-l levels in survival were significantly lower compared with the non-survivals(P<0.05).The area under the curve for the serum SDF-1 level in predicting 28-d mortality was 0.722(P<0.05).CONCLUSION This study provides the SDF-1 changes in patients with HBV-related ACLF.The SDF-1 Level at admission may serve as a promising prognostic marker for predicting short-term prognosis.
基金supported by the National Natural Science Foundation of China,No.82001604Guizhou Provincial Higher Education Science and Technology Innovation Team,No.[2023]072+1 种基金Guizhou Province Distinguished Young Scientific and Technological Talent Program,No.YQK[2023]040Guizhou Provincial Basic Research Program(Natural Science),No.ZK[2021]-368(all to LXiong),and Zunyi City Innovative Talent Team Training Plan,No.[2022]-2.
文摘Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.
基金Supported by Scientific Research Project of Dalian Customs(2022DK09).
文摘[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.
基金supported by the National Natural Science Foundation of China(52231007,12327804,T2321003,22088101)this work was supported in part by the National Key Research Program of China under Grant 2021YFA1200600,and Shanghai Sailing Program(22YF1447800).
文摘Broadband electromagnetic(EM)wave absorption materials play an important role in military stealth and health protection.Herein,metal–organic frameworks(MOFs)-derived magnetic-carbon CoNiM@C(M=Cu,Zn,Fe,Mn)microspheres are fabricated,which exhibit flower-like nano–microstructure with tunable EM response capacity.Based on the MOFs-derived CoNi@C microsphere,the adjacent third element is introduced into magnetic CoNi alloy to enhance EM wave absorption performance.In term of broadband absorption,the order of efficient absorption bandwidth(EAB)value is Mn>Fe=Zn>Cu in the CoNiM@C microspheres.Therefore,MOFs-derived flower-like CoNiMn@C microspheres hold outstanding broadband absorption and the EAB can reach up to 5.8 GHz(covering 12.2–18 GHz at 2.0 mm thickness).Besides,off-axis electron holography and computational simulations are applied to elucidate the inherent dielectric dissipation and magnetic loss.Rich heterointerfaces in CoNiMn@C promote the aggregation of the negative/positive charges at the contacting region,forming interfacial polarization.The graphitized carbon layer catalyzed by the magnetic CoNiMn core offered the electron mobility path,boosting the conductive loss.Equally importantly,magnetic coupling is observed in the CoNiMn@C to strengthen the magnetic responding behaviors.This study provides a new guide to build broadband EM absorption by regulating the ternary magnetic alloy.
基金Supported by the Basic Science Research Program through the National Research Foundation of Korea,NRF-2021R1I1A1A01040732 and NRF-2022R1I1A1A01068652the National Research Foundation of Korea grant funded by the Korean Government,Ministry of Science and ICT,2020R1A2C2009496.
文摘BACKGROUND Osteoarthritis(OA)is the most common joint disorder,is associated with an increasing socioeconomic impact owing to the ageing population.AIM To analyze and compare the efficacy and safety of bone-marrow-derived mesenchymal stromal cells(BM-MSCs)and adipose tissue-derived MSCs(AD-MSCs)in knee OA management from published randomized controlled trials(RCTs).METHODS Independent and duplicate electronic database searches were performed,including PubMed,EMBASE,Web of Science,and Cochrane Library,until August 2021 for RCTs that analyzed the efficacy and safety of AD-MSCs and BM-MSCs in the management of knee OA.The visual analog scale(VAS)score for pain,Western Ontario McMaster Universities Osteoarthritis Index(WOMAC),Lysholm score,Tegner score,magnetic resonance observation of cartilage repair tissue score,knee osteoarthritis outcome score(KOOS),and adverse events were analyzed.Analysis was performed on the R-platform using OpenMeta(Analyst)software.Twenty-one studies,involving 936 patients,were included.Only one study compared the two MSC sources without patient randomization;hence,the results of all included studies from both sources were pooled,and a comparative critical analysis was performed.RESULTS At six months,both AD-MSCs and BM-MSCs showed significant VAS improvement(P=0.015,P=0.012);this was inconsistent at 1 year for BM-MSCs(P<0.001,P=0.539),and AD-MSCs outperformed BM-MSCs compared to controls in measures such as WOMAC(P<0.001,P=0.541),Lysholm scores(P=0.006;P=0.933),and KOOS(P=0.002;P=0.012).BM-MSC-related procedures caused significant adverse events(P=0.003)compared to AD-MSCs(P=0.673).CONCLUSION Adipose tissue is superior to bone marrow because of its safety and consistent efficacy in improving pain and functional outcomes.Future trials are urgently warranted to validate our findings and reach a consensus on the ideal source of MSCs for managing knee OA.
基金supported by the National Natural Science Foundation of China(21336005)the Ministry of Science and Technology of China(2014EG111224)+1 种基金the National Key R&D Program of China(2021YFB4001200)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_3185)。
文摘Herein,Pd nanoparticles loaded Co_(3)O_(4)catalysts(Pd@Co_(3)O_(4))are constructed from zeolitic imidazolate framework-67(ZIF-67)for the ethanol oxidation reaction(EOR).It is demonstrated for the first time that the electrochemical conversion of Co_(3)O_(4)support would result in the charge distribution alignment at the Pd/Co_(3)O_(4)interface and induce the formation of highly reactive Pd-O species(PdO^(*)),which can further catalyze the consequent reactions of the intermediates of the ethanol oxidation.The catalyst,Pd@Co_(3)O_(4)-450,obtained under the optimized conditions exhibits excellent EOR performance with a high mass activity of 590 mA mg-1,prominent operational stability,and extraordinary capability for the electro-oxidation of acetaldehyde intermediates.Importantly,the detailed mechanism investigation reveals that Pd@Co_(3)O_(4)-450 could be benefit to the C-C bond cleavage to promote the desirable C1 pathway for the ethanol oxidation reaction.The present strategy based on the metal-support interaction of the catalyst might provide valuable inspiration for the design of high-performing catalysts for the ethanol oxidation reaction.
文摘Background and Aims: Androgenetic alopecia (AGA) is a common form of hair loss in both men and women. Despite its high prevalence and associated patient morbidity, the approved therapeutic options are limited to finasteride and minoxidil. The present study is aimed at assessing the efficacy of hair serum formulation, Trichosera<sup>®</sup>containing Bone marrow-derived mesenchymal stromal cells conditioned media as an active ingredient, for hair fall control and hair regrowth in healthy Indian human volunteers. Methods: The product was made using a 20% concentration of 10X Conditioned Media along with excipients. The final product was tested for physicochemical parameters, biomarkers, total protein content and microbial limits as per our in-house specifications. Results: The primary irritation patch test showed that the product is non-irritant and dermatologically safe. A clinical study on 40 subjects was conducted to evaluate the effectiveness of the bioactive formulation in hair fall control and hair regrowth in healthy volunteers. Phototrichogram measurement showed hair density and hair growth rate increased significantly by 11.54% and 18.66% at week 24. Hair tensile strength also increased significantly by 41.10% at 12 weeks follow-up. Hair pull test, to see a reduction in pulled hair and comb’s test to show a decrease in hair fall significantly improved from week 4 onwards. There were no significant adverse events in response to the product application. Conclusion: It is concluded that the hair serum product is completely safe on direct application to the scalp and showed significant improvement in the hair growth rate, hair density, scalp condition and reduction in hair fall. .
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 22205205)the Zhejiang Provincial Natural Science Foundation of China (Grant Nos.LQ22B030008)the Science Foundation of Zhejiang Sci-Tech University (ZSTU)(Grant Nos. 21062337-Y and 22062312-Y)。
文摘Electrochemical reduction of Bi-based metal oxides is regarded as an effective strategy to rationally design advanced electrocatalysts for electrochemical CO_(2)reduction reaction(CO_(2)RR).Realizing high selectivity at high current density is important for formate production,but remains challenging.Herein,the BiIn hybrid electrocatalyst,deriving from the Bi2O3/In2O3heterojunction(MOD-Biln),shows excellent catalytic performance for CO_(2)RR.The Faradaic efficiency of formate(FEHCOO-) can be realized over 90% at a wide potential window from-0.4 to-1.4 V vs.RHE,while the partial current density of formate(jHCOO-) reaches about 136.7 mA cm^(-2)at-1.4 V in flow cell without IR-compensation.In additio n,the MOD-Biln exhibits superior stability with high selectivity of formate at 100 mA cm^(-2).Systematic characterizations prove the optimized catalytic sites and interface charge transfer of MOD-Biln,while theoretical calculation confirms that the hybrid structure with dual Bi/In metal sites contribute to the optimal free energy of*H and*OCHO intermediates on MOD-Biln surface,thus accelerating the formation and desorption step of*HCOOH to final formate production.Our work provides a facile and useful strategy to develop highly-active and stable electrocatalysts for CO_(2)RR.
基金supported by the National Natural Science Foundation of China(No.52103308)the Natural Science Foundation of Jiangsu Province of China(No.BK20210826)+4 种基金Outstanding Youth Foundation of Jiangsu Province of China(No.BK20211548)National Key Research and Development Program of China(No.2017YFE0115900)Innovative Science and Technology Platform Project of Cooperation between Yangzhou City and Yangzhou University(No.YZ2020266)Lvyang Jinfeng Plan for Excellent Doctor of Yangzhou City,Special Funds for Self-Made Experimental Equipment of Yangzhou Universitythe Doctor of Suzhou University Scientific Research Foundation Project(No.2022BSK003).
文摘2D MXenes are highly attractive for fabricating high-precision gas sensors operated at room temperature(RT)due to their high surface-to-volume ratio.However,the limited selectivity and low sensitivity are still long-standing challenges for their further applications.Herein,the self-assembly of 0D-2D heterostructure for highly sensitive NO_(2) detection was achieved by integrating ZnO nanoparticles on Ti_(3)C_(2)Tx MXene-derived TiO_(2) nanosheets(designated as ZnO@MTiO_(2)).ZnO nanoparticles can not only act as spacers to prevent the restacking of MTiO_(2) nanosheets and ensure effective transfer for gas molecules,but also enhance the sensitivity of the sensor the through trapping effect on electrons.Meanwhile,MTiO_(2) nanosheets facilitate gas diffusion for rapid sensor response.Benefiting from the synergistic effect of individual components,the ZnO@MTiO_(2)0D-2D heterostructure-based sensors revealed remarkable sensitivity and excellent selectivity to low concentration NO_(2) at RT.This work may facilitate the sensing application of MXene derivative and provide a new avenue for the development of high-performance gas sensors in safety assurance and environmental monitoring.
基金supported by the Department of Science and Technology of Guangdong Province(2019A050510043)。
文摘Rechargeable aprotic Li-O_(2)batteries have attractea increasing attention due to their extremely high capacity,and it is very important to design appropriate strategies to synthesize efficient catalysts used as oxygen cathode.In present work,we present an expedient "instantaneous nucleation and epitaxial growth"(INEG) synthesis strategy for convenient and large-scale synthesis of ultrafine MOCPs nanoparticles(size 50-100 nm) with obvious advantages such as fast synthesis,high yields,low costs and reduced synthetic steps.The bimetallic Ru/Co-MOCPs are further pyrolyzed to obtain bimetallic Coand low content of Ru-based nanoparticles embedded within nitrogen-doped carbon(Ru/Co@N-C) as an efficient catalyst used in Li-O_(2)battery.The Ru/Co@N-C provides porous carbon framework for the ion transportation and O_(2)diffusion,and has large amounts of metal/nonmetal sites as active site to promote the oxygen reduction reaction(ORR)/oxygen evolution reaction(OER) in Li-O_(2)batteries.As a consequence,a high discharge specific capacity of 15246 mA h g^(-1)at 250 mA g^(-1), excellent rate capability at different current densities,and stable overpotential during cycling,are achieved.This work opened up a new understanding for the industrialized synthesis of ultrafine catalysts for Li-O_(2)batteries with excellent structural characteristics and electrochemical performance.
基金supported by the Shandong Natural Science Fund (No.ZR2020KB010)the Fundamental Research Funds for the Central Universities (No.22CX 07010A)。
文摘Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction(OER).Here,bimetallic NiFe-based metal-organic framework(MOF)was prepared by solvothermal method,and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis.The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared.The experimental results showed that when the metal molar ratio was Fe:Ni=1:5 and the pyrolysis temperature was 450℃,the sample(FeNi_(5)-MOF-450)exhibits a composite structure of Ni Fe_(2)O_(4)/FeNi_(3)/C and owns the superior electrocatalytic activity in OER.When the current density is 100 mA·cm^(-2),the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec^(-1),which indicates that FeNi_(5)-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO_(2).Moreover,the long-term stability of FeNi_(5)-MOF-450 further promotes its development in OER.This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.
基金supported by National Nature Science Foundation of China(82172978)Taishan Scholars Program of Shandong Province(Grant No.tsqn201909147)+1 种基金the Key Project at Central Government Level:the ability establishment of sustainable use for valuable Chinese medicine resources(2060302)the Student Innovation Training Program in Jining Medical University(cx2021116).
文摘Background:This study aimed to select compounds with unique inhibitory effects on muscle-invasive bladder cancer(MIBC)from coumarone derivatives with similar parent nuclear structures and to reveal their tumor-suppressive effects using various approaches.Methods:Bladder cancer cell lines SW780 and T24,as well as human normal bladder epithelial cell line SV-HUC-1 were selected as the study model,and these urinary system cells were co-incubated with various concentrations of(S,E)-4-(4-methylbenzylidene)-3-phenylchroman-3-ol,(S,E)-4-(4-isocyanobenzylidene)-3-phenylchroman-3-ol,(S,E)-4-(4-fluorobenzylidene)-3-phenylchroman-3-ol(FPO),and(S,E)-3-phenyl-4-(4-(trifluoromethoxy)benzylidene)chroman-3-ol.Cell activity was detected using cell counting kit-8.FPO showed the strongest inhibitory effect on MIBC cells;therefore,it was selected for further experiments.We monitored the FPO-induced T24 cell morphological changes with an inverted microscope.The FPO-inhibited migration of T24 cells was examined using a cell scratch assay.We detected the clonogenic ability of T24 cells through a clone formation test and evaluated their proliferative ability using a 5-ethynyl-2’-deoxyuridine fluorescence staining kit.The inhibitory effect of FPO against the cell cycle was monitored using flow cytometry,and its suppressive effect on the DNA replication ability of T24 cells was detected using double fluorescence staining(Ki67 and phalloidin).Results:Among the four candidate coumarone derivatives,FPO showed the most significant inhibitory effect on MIBC cells and was less toxic to normal urothelial cells.FPO inhibited T24 cell growth in time and dose-dependent manners(the half-inhibitory concentration is 8μM).FPO significantly repressed the proliferation,migration,and clonogenic ability of bladder cancer T24 cells.Cell mobility was significantly inhibited by FPO:30μM FPO almost completely repressed migration occurred at after 24 h treatment.Moreover,FPO significantly suppressed the clonogenicity of bladder cancer cells in a dose-dependent manner.Mechanistically,FPO targeted the cell cycle,arresting the S and G2 phases on bladder cancer T24 cells.Conclusion:We discovered a novel anticancer chemical,FPO,and proposed a potential mechanism,through which it suppresses MIBC T24 cells by repressing the cell cycle in the S and G2 phases.This study contributes to the development of novel anticancer drugs for MIBC.
基金Project (50572090) supported by the National Natural Science Foundation of ChinaProject (KP200901) supported by the Fund of the State Key Laboratory of Solidification Processing, China
文摘β-SiC ceramic powders were obtained by pyrolyzing polycarbosilane in vacuum at 800-1200 °C. The β-SiC ceramic powders were characterized by TGA/DSC, XRD and Raman spectroscopy. The dielectric properties of β-SiC ceramic powders were investigated by measuring their complex permittivity by rectangle wave guide method in the frequency range of 8.2-18 GHz. The results show that both real part ε′ and imaginary part ε″ of complex permittivity increase with increasing pyrolysis temperature. The mechanism was proposed that order carbon formed at high temperature resulted in electron relaxation polarization and conductance loss, which contributes to the increase in complex permittivity.
基金The National Natural Science Foundation of China(No.51476032)
文摘A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel (RDF). The CaO dechlorination model obtained by the thermal gravity analysis (TGA) is coupled to investigate the process of CaO dechlorination. An Eulerian-Eulerian method is adopted to simulate the gas-solid flow and self-developed chemical reaction modules are used to simulate chemical reactions. Flow patterns, gasification results and dechlorination efficiency are obtained by numerical simulation. Meanwhile, simulations are performed to evaluate the effects of Ca/Cl molar ratio and temperature on dechlorination efficiency. The simulation results show that the presence of bubbles in the gasifier lowers the CaO dechlorination efficiency. Increasing the Ca/Cl molar ratio can enhance the dechlorination efficiency. However, with the temperature increasing, the dechlorination efficiency increases initially and then decreases. The optimal Ca/Cl molar ratio is in the range of 3. 0 to 3. 5 and the optimal temperature is 923K.
基金the National Nature Science Foundation of China(No.61427803).
文摘In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MEDO,and achieves the automatic adjustment of the parameters.The proposed method is named as adaptive Maxwell’s equations derived optimization(AMEDO).In order to evaluate the performance of AMEDO,eight benchmarks are used and the results are compared with the original MEDO method.The results show that AMEDO can greatly reduce the workload of manual adjustment of parameters,and at the same time can keep the accuracy and stability.Moreover,the convergence of the optimization can be accelerated due to the dynamical adjustment of the parameters.In the end,the proposed AMEDO is applied to the side lobe level suppression and array failure correction of a linear antenna array,and shows great potential in antenna array synthesis.
基金supported by National Natural Science Foundation of China(11701024)the Fundamental Research Funds for the Central Universities(2019RC17)。
文摘Factor properties and their structures are important themes in combinatorics on words.Let D be the infinite one-sided sequence over the alphabet{a,b}generated by the period-doubling substitutionσ(a)=ab andσ(b)=aa.In this paper,we determine the derived sequence D_(ω)(D)for any factorω■D,and study some factor spectra using the structures of derived sequences.We also prove the reflexivity property of derived sequences.
文摘OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression of transduced gene by X-gal staining was examined. Then plasmid pcDNA3-rhBMP7 was delivered to cultured BMSCs. Through immunohistochemical staining and RT-PCR assay, the expression of rhBMP7 gene was detected. RESULTS: The exogenous gene could be expressed efficiently in transduced BMSCs. CONCLUSION: The present study provided a theoretical basis to gene therapy on the problems of bone and cartilage tissue.
文摘Fundamental units of measurements are kilograms, meters, and seconds—in regards to mass length, and time. All other measurements in mechanical quantities including kinetic quantities and dynamic quantities are called derived units. These derived units can be expressed in terms of fundamental units, such as acceleration, area, energy, force, power, velocity and volume. Derived quantities will be referred to as time, length, and mass. In order to explain that fundamental units are not equivalent with fundamental quantities, we need to understand the contraction of time and length in Special Relativity. If we choose the velocity of light as fundamental quantity and length and time as derived quantities, then we are able to construct three-dimensional space-time frames. Three-dimensional space-time frames representing time with polar coordination, time contraction and length contraction can be shown graphically.
基金supported by a grant from the National Natural Science Foundation of China (No. 30500688)
文摘BACKGROUND: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin., an anthraquinone derivative from Radix et Rhizoma Rhei, and baicalein, a flavone from Scutellaria baicalensis Georgi, both have been reported to possess anti-inflammatory activities. The expression pattern of SDF-1 in experimental acute pancreatitis (AP) and the effect of emodin or baicalein on that are not well defined. The present study aimed to investigate the effects of emodin and baicalein on pancreatic myeloperoxidase (MPO) activity (reflecting leukocyte sequestration) and cytokine production, as well as tissue SDF-1 expression in the setting of AP. METHODS: A :rat model of AP was induced by administration (of 5% sodium taurocholate through the biliopancreatic duct. The level of tumor necrosis factor-a (TNF-alpha), interleukin-6 (IL-6) and MPO in the pancreas, and serum amylase were tested by immunohistochemistry, ELISA and chromatometry. The expressions of SDF-1 alpha and SDF-1 beta were detected by real-time PCR, Western blotting, and immunohistochemistry. RESULT: Combination of emodin and baicalein significantly reduced pancreatic TNIP-alpha, IL-6 and MPO, and also inhibited pancreatic SDF-1 expression. CONCLUSIONS: The inhibition of SDF-1 expression by emodin and baicalein might contribute, in part at least, to the amelioration of pancreatic inflammation. The present study also shows benefits of simultaneous treatment of AP.