Contemporary higher education prioritizes cultivating students’key competencies and comprehensive problem-solving abilities,specifically fostering innovation,goal orientation,and initiative.This study investigates a ...Contemporary higher education prioritizes cultivating students’key competencies and comprehensive problem-solving abilities,specifically fostering innovation,goal orientation,and initiative.This study investigates a pedagogical framework that synergizes Research-Led Learning(RLL)and Project-Based Learning(PBL)to establish an open,exploratory learning environment.Employing a case study methodology,the research tracked architecture students engaging in a structured PBL process involving rigorous research activities—ranging from theoretical analysis to field investigations—to develop evidence-based design solutions.Evaluations from both student and faculty perspectives assessed the pedagogical effectiveness regarding learning outcomes and competency development.The findings indicate that this methodology effectively bridges the gap between research and practice,significantly bolstering students’capacity to address authentic challenges and propelling self-directed learning in architectural education.展开更多
Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-gene...Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-generation(3G)and became highly popular in the fourthgeneration(4G).To increase the data rate along with low latency and mass connectivity the fifth-generation(5G)networks are being installed from 2020.However,the 5G technology will not be able to fulfill the data demand at the end of this decade.Therefore,it is expected that 6G communication networks will rise,providing better services through the implementation of new enabling technologies and allowing users to connect everywhere.6G technology would not be confined to cellular communications networks,but would also comply with non-terrestrial communication system requirements,such as satellite communication.The ultimate objectives of this work are to address the major challenges of the evolution of cellular communication networks and to discourse the recent growth of the industry based on the key scopes of application and challenges.The main areas of research topics are summarized into(i)major 6G wireless networkmilestones;(ii)key performance indicators;(iii)future new applications;and(iv)potential fields of research,challenges,and open issues.展开更多
Objective:To investigate the effects of quercetin on inflammatory signaling pathways and hepatic oxidative injury using a streptozotocin-induced liver injury model.Methods:Four groups of 32 rats were used in this stud...Objective:To investigate the effects of quercetin on inflammatory signaling pathways and hepatic oxidative injury using a streptozotocin-induced liver injury model.Methods:Four groups of 32 rats were used in this study:three groups were given streptozotocin to induce diabetes,and one group was given a normal control.For treatment groups,each group received either metformin(200 mg/kg body weight)or quercetin(50 mg/kg body weight)for a month.The expression of SREBP1c was detected by quantitative RT-PCR and fibrosis-related proteins(TGF-βand p-Smad3)was evaluated by Western blot.Furthermore,MCP and IL-1βwere determined by ELISA.Results:Quercetin significantly reduced insulin and glucose levels.Besides,it reduced the serum levels of ALT,AST,and ALP,improved lipid profile,lowered the MDA level,increased SOD activity,decreased the rise in MCP-1 and IL-1β,inhibited the TGF-β/Smad3 signaling pathway,decreasedα-SMA and SREBP1c expression,and increased AMPK(P<0.05).Conclusions:Quercetin could significantly mitigate hepatic damage by modulating the expression of pro-inflammatory cytokines and fibrosis markers.展开更多
This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,a...This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,and samarium was prepared by dissolving their pure mixed oxide(reclaimed from spent Ni-MH batteries)in a diluted HCl solution.Key extractants,including bis(2,4,4-trimethylpentyl)phosphinic acid(Cyanex 272),Cyanex 572,trialkylphosphine oxide(Cyanex 923),and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC 88A),along with tributyl phosphate(TBP)as a phase modifier,were utilized to form organic systems.The extraction behavior and separability of these systems at various pH levels as well as their extraction mechanisms were investigated.The results demonstrated a direct relationship between the extraction trend and the experimental pH value,with enhanced selectivity when TBP was added.Notably,Nd and Pr exhibited similar extraction behaviors,with minor deviations from Ce,making their separation difficult to achieve.Sm extraction followed a distinct trend,allowing for its separation from other elements at pH≤2.In contrast,La exhibited a low affinity for coordination with extractants when pH was≤3.5,facilitating the separation of other elements from La,which could then be isolated in the raffinate.Among the studied organic systems,combinations of Cyanex 572 and PC 88A with TBP demonstrated superior performance in element separation.Optimum separation factors were calculated withβ_(Ce/La)=12,βNd/La=87,β_(Pr/La)=127,andβ_(Sm/La)=3191 for the former,andβ_(Sm/Ce)=54,β_(Sm/Nd)=20,andβ_(Sm/Pr)=14 for the latter.These findings provide valuable insights for selecting extraction systems and designing experiments for the effective solvent extraction separation of light REEs from their mixture.展开更多
According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae ...According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae of T.granarium fed on wheat seeds(25 gm)treated with different weights of silica as well as silica nanoparticles(20,40,60 and 80 mg)at different temperature(9℃,25℃,and 35℃).Study showed that using silica nanoparticles in cold temperature(9℃)was the most efficient treatment with the lowest LC_(50)(lethal concentration required to kill 50%of the population)value and caused the highest toxicity index.In contrast,the least efficient treatment(25℃)with the highest LC_(50) value and showed lowest toxicity index was using silica in normal temperature,when using silica nanoparticles,the cold temperature was the best condition followed by hot temperature(35℃)and finally the normal temperature.On the other hand,using silica in hot temperature was most effective followed by silica with cold temperature and finally silica with normal temperature.The biochemical assays revealed that the change in the experimental temperature had a nonsignificant effect on the total protein content of the larvae.The total lipids and total carbohydrates exhibited a significant increase due to hot treating.5th instar larvae of T.granarium treated with LC50 of silica at high temperature led to a nonsignificant(p≤0.05)decrease in Acetylcholinesterase(AchE)activity compared to treatment at normal temperature.In contrast,Glutathione S-transferase(GST)and Peroxidase activities were significantly(p≤0.05)raised due to the treatment conducted at high temperature.Additionally,treating larvae with LC50 of silica nanoparticles at low temperature caused a significant increase in both GST and peroxidase activities,while the increase in AChE was nonsignificantly(p≤0.05)compared to treatment at normal temperature.Using silica at low temperature could be used as an alternative to chemical insecticides to control T.granarium larvae.展开更多
The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows ...The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows that the area is contaminated with nutrients.However,it is necessary to clarify the level of pollution and the impact of polluting factors on biological communities and ecological status in the area.Two marine biotic indices AZTI’s marine biotic index(AMBI)and multivariate-AMBI(M-AMBI)were used to shed light on these issues.This research reveals the outcomes of applying these indicators in evaluating the ecological status in the area.The results show that the environment of the Xuan Dai Bay is being polluted.The most severe pollution level is at stations close to denser farms sites;while the lower pollution is found at stations near the mouth of the bay.The benthic community was imbalanced at all sampling stations,ranging from mild to moderate levels;while the ecological status is moderate,except good-high quality status close to the mouth.展开更多
Proton exchange membrane fuel cells(PEMFCs)constitute a promising avenue for environmentally friendly power generation.However,the reliance on unsustainable platinum-based electrocatalysts used at the electrodes poses...Proton exchange membrane fuel cells(PEMFCs)constitute a promising avenue for environmentally friendly power generation.However,the reliance on unsustainable platinum-based electrocatalysts used at the electrodes poses challenges to the commercial viability of PEMFCs.Non-platinum group metal(non-PGM)alternatives,like nitrogen-coordinated transition metals in atomic dispersion(M–N–C catalysts),show significant potential.This work presents a comparative study of two distinct sets of Fe–N–C materials,prepared by pyrolyzing hybrid composites of polyaniline(PANI)and iron(Ⅱ)chloride on a hard template.One set uses bipyridine(BPy)as an additional nitrogen source and iron ligand,offering an innovative approach.The findings reveal that the choice of pyrolysis temperature and atmosphere influences the catalyst properties.The use of ammonia in pyrolysis emerges as a crucial parameter for promoting atomic dispersion of iron,as well as increasing surface area and porosity.The optimal catalyst,prepared using BPy and ammonia,exhibits a half-wave potential of 0.834 V in 0.5 M H_(2)SO_(4)(catalyst loading of 0.6 mg cm^(-2)),a mass activity exceeding 3 A g^(-1)and high stability in acidic electrolyte,positioning it as a promising non-PGM structure in the field.展开更多
The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lam...The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lamellae and ferrite recrystallisation for a range of deformation temperatures(600–700℃),cooling/soaking time(water quenching,air cooling,10 and 30 min of soaking time)and interpass time(0–10 s)was analysed.During deformation,the spheroidisation of pearlite is dynamically accelerated mainly by boundary splitting mechanism together with the rapid dissolution of cementite,while ferrite softening is attributed to dynamic recovery and continuous dynamic recrystallisation.The strong microstructural evolution during cooling/soaking time indicates that deformation energy accumulated is sufficient to activate metallurgical phenomena in both phases also statically.Static spheroidisation is a diffusive process,with rate controlled by the diffusion of vacancies,as suggested by the estimated activation energy.Ferrite refinement is the result of the evolution of continuous recrystallisation and pinning effect exerted by fine,globulised and homogeneously dispersed cementite particles.Increasing temperature causes accelerated kinetics in metallurgical phenomena;therefore,cooling/soaking time becomes key parameters to achieve ultrafine grained and spheroidised microstructures.Interpass time favours spheroidisation and promotes continuous recrystallisation;however,it must be carefully controlled to find a balance between recrystallisation and Ostwald ripening to optimise microstructural development.展开更多
Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-...Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-based catalysts,their further developments are hindered by the uncertainties related to the kind of the active sites involved in the desired and side reactions.To contribute to closing such a gap,we systematically investigate the role of oxidized CoO_(x) and metallic Co0 species in the PDH reaction over catalysts based in Silicalite-1 with supported CoO_(x) species differing in their redox properties.C_(3)H_(8) pulse experiments with sub-millisecond and second resolution at pulse sizes of about 13 and 2200 nmol,respectively,combined with in-depth catalyst characterization and PDH tests at different propane conversions enabled us to understand how the reaction-induced reduction of CoO_(x) affects product selectivity.Propane readily reacts with CoO_(x) to yield propene,carbon oxides and water.The formed Co0 species show high activity to coking and cracking reactions.However,if the size of such species is below 2 nm,these undesired reactions are significantly hindered due to the coverage of the active sites by carbon-containing species.The remaining uncovered surface Co0 sites selectively dehydrogenate propane to propene.The best-performing catalyst showed higher activity than a commercial-like K-CrOx/Al_(2)O_(3) and operated durable in a series of 10 dehydrogenation/regeneration cycles under industrial relevant conditions.The space time yield of propene formation of 0.97 kg·h^(-1)·kgcat^(-1) was achieved at 550℃,52%equilibrium propane conversion and 95% propene selectivity.展开更多
The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substi...The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substitut-ing commercial plastics for a biodegradable renewable polymer for many applications,low-density polyethylene(LDPE)was mixed with varying concentrations of algal biomass(AB).Algae are considered a clean,renewable energy source because they don’t harm the environment and can be used to create bioplastics.Algal biomass grown in a high rate algal pond(HRAP)used for wastewater treatment used at 12.5-50 weight percent.Mechan-ical,thermal,and morphological characteristics of the LDPE/AB mixes were studied.Improved compatibility and uniformity between the LDPE matrix and algal biomass phase were evident in the morphology of LDPE/AB blends.Tensile strength(TS)and elastic modulus(EM)of the prepared LDPE/AB blends significantly decreased to 4.63 and 255 MPa,respectively.Nevertheless,by increasing the concentration of AB up to 25%and 37.5%,the mechanical properties enhanced and raised to(TS=6.75 MPa,EM=426 MPa)and(TS=7 MPa,EM=494 MPa),respectively.Using 25%and 37.5%of AB significantly enhanced the miscibility and interaction between algal bio-mass and LDPE polymer.However,increasing the percentage of AB led to a reduction in the thermal stability of the LDPE/AB.In contrast,compatibilized blends demonstrated better thermal stability compared to un-compa-tibilized blends.These findings indicate that it is possible to develop a blend with improved structural,thermal,and mechanical properties by partially replacing LDPE with biodegradable algal biomass.展开更多
Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biologica...Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biological maturity and the limitations of existing testing methods, particularly in adolescent sports contexts, there is a pressing need for a non-invasive method that is convenient, accurate, and broadly applicable to monitor the biological maturity of adolescent athletes comprehensively. In response to this need, a maturity assessment method based on the smartphone application Maturo has been developed. This study evaluates the accuracy and validity of the Maturo software, an automated tool for estimating biological age and related maturation metrics.Methods: A sample of 103 actively training teenage athletes aged 9-17 years. The sample included 76 males(age = 11.74 ± 1.55 years, mean ±SD) and 27 females(age = 13.95 ± 1.40 years), all without medical conditions that might impact growth or development.Results: Compared to traditional expert evaluations, the intraclass correlation coefficients(ICCs) and Pearson correlation coefficients demonstrated reliable positive correlations and significant agreement between the Maturo software and expert methods across multiple metrics, such as biological age(ICC = 0.965, R = 0.97), corrected biological age(ICC = 0.973, R = 0.99), predicted adult height(ICC = 0.991, R = 0.99), and percentage of adult height achieved(ICC = 0.955, R = 0.97). The Bland-Altman plots provided additional evidence of the validity of the Maturo software estimations, showing low systematic error in most measures. The linear regression analysis produced excellent adjusted R2values: 0.95for biological age and 0.99 for anticipated adult height. The Maturo approach demonstrated a high level of dependability in classifying teenagers into groups based on their maturity status and timing. The κ coefficients of 0.93 for maturity status and 0.82 for maturity timing indicate a nearly perfect agreement with the expert technique.Conclusion: While the Maturo software's non-invasive nature, cost-effectiveness, and ease of use could make it a potential tool for regular monitoring of growth and maturation in young athletes, its promising results in assessing maturation should be interpreted with caution due to limitations such as sample size and demographic constraints. Further longitude research with larger and more diverse populations is needed to validate these preliminary findings and strengthen the evidence for its broader applicability.展开更多
Clinical translation of tissue-engineered advanced therapeutic medicinal products is hindered by a lack of patient-dependent and independent in-process biological quality controls that are reflective of in vivo outcom...Clinical translation of tissue-engineered advanced therapeutic medicinal products is hindered by a lack of patient-dependent and independent in-process biological quality controls that are reflective of in vivo outcomes.Recent insights into the mechanism of native bone repair highlight a robust path dependence.Organoid-based bottom-up developmental engineering mimics this pathdependence to design personalized living implants scaffold-free,with in-build outcome predictability.Yet,adequate(noninvasive)quality metrics of engineered tissues are lacking.Moreover,insufficient insight into the role of donor variability and biological sex as influencing factors for the mechanism toward bone repair hinders the implementation of such protocols for personalized bone implants.Here,male and female bone-forming organoids were compared to non-bone-forming organoids regarding their extracellular matrix composition,transcriptome,and secreted proteome signatures to directly link in vivo outcomes to quality metrics.As a result,donor variability in bone-forming callus organoids pointed towards two distinct pathways to bone,through either a hypertrophic cartilage or a fibrocartilaginous template.The followed pathway was determined early,as a biological sexdependent activation of distinct progenitor populations.Independent of donor or biological sex,a cartilage-to-bone transition was driven by a common panel of secreted factors that played a role in extracellular matrix remodeling,mineralization,and attraction of vasculature.Hence,the secreted proteome is a source of noninvasive biomarkers that report on biological potency and could be the missing link toward data-driven decision-making in organoid-based bone tissue engineering.展开更多
Al-x%Sc-0.11%Zr alloys （x=0, 0.02, 0.05, 0.08, 0.11, 0.15） were produced by a chill cast procedure. The effect of Sc content on the precipitation of Al3（Sc,Zr） during heat treatment at 475 °C for 12 h was stu...Al-x%Sc-0.11%Zr alloys （x=0, 0.02, 0.05, 0.08, 0.11, 0.15） were produced by a chill cast procedure. The effect of Sc content on the precipitation of Al3（Sc,Zr） during heat treatment at 475 °C for 12 h was studied. Nucleation, precipitation and distribution of Al3（Sc,Zr） precipitates were found to be strongly related to the Sc content. With increasing the Sc content, the average radius of the precipitates decreases, while the number density of the precipitates increases, as investigated by transmission electron microscopy （TEM）. The distribution of the precipitates becomes more and more homogeneous when the Sc content is increased. The recrystallization resistance of samples that was 90% cold rolled and isothermal annealed for half an hour in the temperature range of 200-600 °C was investigated. The results show that the recrystallization temperature varies from 250 °C for the alloy without Sc to about 600 °C for the alloy containing 0.15% Sc because of the high density of Al3（Sc,Zr） precipitates.展开更多
The precipitation behaviours of Al3Zr precipitate in the Al-Cu-Zr and Al-Cu-Zr-Ti-V alloys were studied by transmission electron microscopy. Metastable Al3Zr precipitates are homogeneously nucleated in dendrite centre...The precipitation behaviours of Al3Zr precipitate in the Al-Cu-Zr and Al-Cu-Zr-Ti-V alloys were studied by transmission electron microscopy. Metastable Al3Zr precipitates are homogeneously nucleated in dendrite centres resulting in homogeneous distribution. However, the precipitation in the interdendritic regions is complex and the precipitation morphologies, helical-like and stripe-like shapes, were observed, which are composed of many spherical Al3Zr precipitates. The stripe-like precipitate clusters have preferential orientations along with the -100- Al directions, which is inferred to be related to θ′（Al2Cu） and θ phases. Addition of Cu can accelerate the L12→D023 structural transformation of the Al3Zr precipitate.展开更多
Microplastic contamination has emerged as a threat in transplantation,with evidence of its presence in human tissues and potential to compromise grafts.Transplant recipients,vulnerable due to immunosuppression and sur...Microplastic contamination has emerged as a threat in transplantation,with evidence of its presence in human tissues and potential to compromise grafts.Transplant recipients,vulnerable due to immunosuppression and surgical exposure,face risk from microplastics via airborne particles,surgical materials,and organ preservation systems.These particles trigger inflammation,oxidative stress,and immune dysregulation—pathways critical in rejection.Microplastics support biofilm formation,potentially facilitating antimicrobial resistance in clinical settings.Despite this risk,transplant-specific research is lacking.We urge action through environmental controls,material substitutions,and procedural modifications,alongside research targeting exposure pathways,biological impact,and mitigation strategies.Transplantation has historically led medical innovation and must do so in confronting this environmental challenge.Leadership from global transplant societies is essential to protect recipients and ensure safe procedures.展开更多
Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many micro...Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.展开更多
Aim： To detect the expression of hepatitis B virus （HBV） genes （HB S and C genes） in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fer...Aim： To detect the expression of hepatitis B virus （HBV） genes （HB S and C genes） in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fertilization （IVF） technique. Methods： Human sperm-mediated HBV genes were delivered into zona-free hamster oocytes by the IVF method. Polymerase chain reaction （PCR） was used to detect HB S and pre-Core/Core （pre-C/C） coding genes both in one- and two-cell embryos. Reverse transcription-PCR （RT-PCR） analysis was used to study the expression of the two genes. Fluorescence in situ hybridization （FISH） analysis using the full-length HBV DNA as the hybridization probe was performed to confirm the integration of viral DNA in the host embryonic genome. Results： Both HB S and pre-C/C coding genes are present and transcribed in one- and two-cell embryos originated from hamster ova IVF with human spermatozoa carrying HBV DNA sequences. Conclusion： Sperm-mediated HBV genes are able to replicate and express themselves in early embryonic cells. These results provide direct evidence that HBV DNA could transmit vertically to the next generation via the male germ line.展开更多
The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with ...The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with residues of Posidonia oceanica （PoR）, collected from Tunis beaches. The accumulation in beaches （as well as their removal） constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion： （a） C/N ratio 〈 15; （b） NH4^＋-N 〈 400 mg/kg; （c） CO2-C 〈 2000 mg CO2-C/kg; （d） dehydrogenase activity 〈 1 mg TPF/g dry matter; （e） germination index （GI） 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N （13.0 g/kg）, P （4.74 g/kg） and MgO （15.80 g/kg）. Thus composting definitively constitutes the most optimal option to exploit these wastes.展开更多
The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investiga...The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units （CRDPF-1 and CRDPF-2） with different specifications were separately retrofitted to the engine running with European steady-state cycle （ESC）. An electrical low pressure impactor （ELPI） was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate （RcR） of hydrocarbons （HC） and carbon monoxide （CO） across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio （A/F） at higher loads.展开更多
Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal...Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.展开更多
基金received approval from a committee named Innovation Institute for Sustainable Maritime Architecture Research and Technology(iSMART)(The certificate number was 2022-5-22-01).
文摘Contemporary higher education prioritizes cultivating students’key competencies and comprehensive problem-solving abilities,specifically fostering innovation,goal orientation,and initiative.This study investigates a pedagogical framework that synergizes Research-Led Learning(RLL)and Project-Based Learning(PBL)to establish an open,exploratory learning environment.Employing a case study methodology,the research tracked architecture students engaging in a structured PBL process involving rigorous research activities—ranging from theoretical analysis to field investigations—to develop evidence-based design solutions.Evaluations from both student and faculty perspectives assessed the pedagogical effectiveness regarding learning outcomes and competency development.The findings indicate that this methodology effectively bridges the gap between research and practice,significantly bolstering students’capacity to address authentic challenges and propelling self-directed learning in architectural education.
基金This research was supported by the National Research Foundation(NRF),Korea(2019R1C1C1007277)funded by the Ministry of Science and ICT(MSIT),Korea.
文摘Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-generation(3G)and became highly popular in the fourthgeneration(4G).To increase the data rate along with low latency and mass connectivity the fifth-generation(5G)networks are being installed from 2020.However,the 5G technology will not be able to fulfill the data demand at the end of this decade.Therefore,it is expected that 6G communication networks will rise,providing better services through the implementation of new enabling technologies and allowing users to connect everywhere.6G technology would not be confined to cellular communications networks,but would also comply with non-terrestrial communication system requirements,such as satellite communication.The ultimate objectives of this work are to address the major challenges of the evolution of cellular communication networks and to discourse the recent growth of the industry based on the key scopes of application and challenges.The main areas of research topics are summarized into(i)major 6G wireless networkmilestones;(ii)key performance indicators;(iii)future new applications;and(iv)potential fields of research,challenges,and open issues.
文摘Objective:To investigate the effects of quercetin on inflammatory signaling pathways and hepatic oxidative injury using a streptozotocin-induced liver injury model.Methods:Four groups of 32 rats were used in this study:three groups were given streptozotocin to induce diabetes,and one group was given a normal control.For treatment groups,each group received either metformin(200 mg/kg body weight)or quercetin(50 mg/kg body weight)for a month.The expression of SREBP1c was detected by quantitative RT-PCR and fibrosis-related proteins(TGF-βand p-Smad3)was evaluated by Western blot.Furthermore,MCP and IL-1βwere determined by ELISA.Results:Quercetin significantly reduced insulin and glucose levels.Besides,it reduced the serum levels of ALT,AST,and ALP,improved lipid profile,lowered the MDA level,increased SOD activity,decreased the rise in MCP-1 and IL-1β,inhibited the TGF-β/Smad3 signaling pathway,decreasedα-SMA and SREBP1c expression,and increased AMPK(P<0.05).Conclusions:Quercetin could significantly mitigate hepatic damage by modulating the expression of pro-inflammatory cytokines and fibrosis markers.
基金support from the Australian Research Council’s Industrial Transformation Research Hub funding scheme(project IH190100009).
文摘This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,and samarium was prepared by dissolving their pure mixed oxide(reclaimed from spent Ni-MH batteries)in a diluted HCl solution.Key extractants,including bis(2,4,4-trimethylpentyl)phosphinic acid(Cyanex 272),Cyanex 572,trialkylphosphine oxide(Cyanex 923),and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC 88A),along with tributyl phosphate(TBP)as a phase modifier,were utilized to form organic systems.The extraction behavior and separability of these systems at various pH levels as well as their extraction mechanisms were investigated.The results demonstrated a direct relationship between the extraction trend and the experimental pH value,with enhanced selectivity when TBP was added.Notably,Nd and Pr exhibited similar extraction behaviors,with minor deviations from Ce,making their separation difficult to achieve.Sm extraction followed a distinct trend,allowing for its separation from other elements at pH≤2.In contrast,La exhibited a low affinity for coordination with extractants when pH was≤3.5,facilitating the separation of other elements from La,which could then be isolated in the raffinate.Among the studied organic systems,combinations of Cyanex 572 and PC 88A with TBP demonstrated superior performance in element separation.Optimum separation factors were calculated withβ_(Ce/La)=12,βNd/La=87,β_(Pr/La)=127,andβ_(Sm/La)=3191 for the former,andβ_(Sm/Ce)=54,β_(Sm/Nd)=20,andβ_(Sm/Pr)=14 for the latter.These findings provide valuable insights for selecting extraction systems and designing experiments for the effective solvent extraction separation of light REEs from their mixture.
文摘According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae of T.granarium fed on wheat seeds(25 gm)treated with different weights of silica as well as silica nanoparticles(20,40,60 and 80 mg)at different temperature(9℃,25℃,and 35℃).Study showed that using silica nanoparticles in cold temperature(9℃)was the most efficient treatment with the lowest LC_(50)(lethal concentration required to kill 50%of the population)value and caused the highest toxicity index.In contrast,the least efficient treatment(25℃)with the highest LC_(50) value and showed lowest toxicity index was using silica in normal temperature,when using silica nanoparticles,the cold temperature was the best condition followed by hot temperature(35℃)and finally the normal temperature.On the other hand,using silica in hot temperature was most effective followed by silica with cold temperature and finally silica with normal temperature.The biochemical assays revealed that the change in the experimental temperature had a nonsignificant effect on the total protein content of the larvae.The total lipids and total carbohydrates exhibited a significant increase due to hot treating.5th instar larvae of T.granarium treated with LC50 of silica at high temperature led to a nonsignificant(p≤0.05)decrease in Acetylcholinesterase(AchE)activity compared to treatment at normal temperature.In contrast,Glutathione S-transferase(GST)and Peroxidase activities were significantly(p≤0.05)raised due to the treatment conducted at high temperature.Additionally,treating larvae with LC50 of silica nanoparticles at low temperature caused a significant increase in both GST and peroxidase activities,while the increase in AChE was nonsignificantly(p≤0.05)compared to treatment at normal temperature.Using silica at low temperature could be used as an alternative to chemical insecticides to control T.granarium larvae.
基金A project at the Joint Vietnam-Russia Tropical Science and Technology Research Center under contract No.1113/QD-TTNDVN.
文摘The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows that the area is contaminated with nutrients.However,it is necessary to clarify the level of pollution and the impact of polluting factors on biological communities and ecological status in the area.Two marine biotic indices AZTI’s marine biotic index(AMBI)and multivariate-AMBI(M-AMBI)were used to shed light on these issues.This research reveals the outcomes of applying these indicators in evaluating the ecological status in the area.The results show that the environment of the Xuan Dai Bay is being polluted.The most severe pollution level is at stations close to denser farms sites;while the lower pollution is found at stations near the mouth of the bay.The benthic community was imbalanced at all sampling stations,ranging from mild to moderate levels;while the ecological status is moderate,except good-high quality status close to the mouth.
基金funding from the Hellenic Foundation for Research and Innovation(HFRI)under grant agreement No 3655.
文摘Proton exchange membrane fuel cells(PEMFCs)constitute a promising avenue for environmentally friendly power generation.However,the reliance on unsustainable platinum-based electrocatalysts used at the electrodes poses challenges to the commercial viability of PEMFCs.Non-platinum group metal(non-PGM)alternatives,like nitrogen-coordinated transition metals in atomic dispersion(M–N–C catalysts),show significant potential.This work presents a comparative study of two distinct sets of Fe–N–C materials,prepared by pyrolyzing hybrid composites of polyaniline(PANI)and iron(Ⅱ)chloride on a hard template.One set uses bipyridine(BPy)as an additional nitrogen source and iron ligand,offering an innovative approach.The findings reveal that the choice of pyrolysis temperature and atmosphere influences the catalyst properties.The use of ammonia in pyrolysis emerges as a crucial parameter for promoting atomic dispersion of iron,as well as increasing surface area and porosity.The optimal catalyst,prepared using BPy and ammonia,exhibits a half-wave potential of 0.834 V in 0.5 M H_(2)SO_(4)(catalyst loading of 0.6 mg cm^(-2)),a mass activity exceeding 3 A g^(-1)and high stability in acidic electrolyte,positioning it as a promising non-PGM structure in the field.
基金financially supported by the European Coal and Steel Community(RFCS-2015.No.709828).
文摘The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lamellae and ferrite recrystallisation for a range of deformation temperatures(600–700℃),cooling/soaking time(water quenching,air cooling,10 and 30 min of soaking time)and interpass time(0–10 s)was analysed.During deformation,the spheroidisation of pearlite is dynamically accelerated mainly by boundary splitting mechanism together with the rapid dissolution of cementite,while ferrite softening is attributed to dynamic recovery and continuous dynamic recrystallisation.The strong microstructural evolution during cooling/soaking time indicates that deformation energy accumulated is sufficient to activate metallurgical phenomena in both phases also statically.Static spheroidisation is a diffusive process,with rate controlled by the diffusion of vacancies,as suggested by the estimated activation energy.Ferrite refinement is the result of the evolution of continuous recrystallisation and pinning effect exerted by fine,globulised and homogeneously dispersed cementite particles.Increasing temperature causes accelerated kinetics in metallurgical phenomena;therefore,cooling/soaking time becomes key parameters to achieve ultrafine grained and spheroidised microstructures.Interpass time favours spheroidisation and promotes continuous recrystallisation;however,it must be carefully controlled to find a balance between recrystallisation and Ostwald ripening to optimise microstructural development.
文摘Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-based catalysts,their further developments are hindered by the uncertainties related to the kind of the active sites involved in the desired and side reactions.To contribute to closing such a gap,we systematically investigate the role of oxidized CoO_(x) and metallic Co0 species in the PDH reaction over catalysts based in Silicalite-1 with supported CoO_(x) species differing in their redox properties.C_(3)H_(8) pulse experiments with sub-millisecond and second resolution at pulse sizes of about 13 and 2200 nmol,respectively,combined with in-depth catalyst characterization and PDH tests at different propane conversions enabled us to understand how the reaction-induced reduction of CoO_(x) affects product selectivity.Propane readily reacts with CoO_(x) to yield propene,carbon oxides and water.The formed Co0 species show high activity to coking and cracking reactions.However,if the size of such species is below 2 nm,these undesired reactions are significantly hindered due to the coverage of the active sites by carbon-containing species.The remaining uncovered surface Co0 sites selectively dehydrogenate propane to propene.The best-performing catalyst showed higher activity than a commercial-like K-CrOx/Al_(2)O_(3) and operated durable in a series of 10 dehydrogenation/regeneration cycles under industrial relevant conditions.The space time yield of propene formation of 0.97 kg·h^(-1)·kgcat^(-1) was achieved at 550℃,52%equilibrium propane conversion and 95% propene selectivity.
文摘The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substitut-ing commercial plastics for a biodegradable renewable polymer for many applications,low-density polyethylene(LDPE)was mixed with varying concentrations of algal biomass(AB).Algae are considered a clean,renewable energy source because they don’t harm the environment and can be used to create bioplastics.Algal biomass grown in a high rate algal pond(HRAP)used for wastewater treatment used at 12.5-50 weight percent.Mechan-ical,thermal,and morphological characteristics of the LDPE/AB mixes were studied.Improved compatibility and uniformity between the LDPE matrix and algal biomass phase were evident in the morphology of LDPE/AB blends.Tensile strength(TS)and elastic modulus(EM)of the prepared LDPE/AB blends significantly decreased to 4.63 and 255 MPa,respectively.Nevertheless,by increasing the concentration of AB up to 25%and 37.5%,the mechanical properties enhanced and raised to(TS=6.75 MPa,EM=426 MPa)and(TS=7 MPa,EM=494 MPa),respectively.Using 25%and 37.5%of AB significantly enhanced the miscibility and interaction between algal bio-mass and LDPE polymer.However,increasing the percentage of AB led to a reduction in the thermal stability of the LDPE/AB.In contrast,compatibilized blends demonstrated better thermal stability compared to un-compa-tibilized blends.These findings indicate that it is possible to develop a blend with improved structural,thermal,and mechanical properties by partially replacing LDPE with biodegradable algal biomass.
文摘Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biological maturity and the limitations of existing testing methods, particularly in adolescent sports contexts, there is a pressing need for a non-invasive method that is convenient, accurate, and broadly applicable to monitor the biological maturity of adolescent athletes comprehensively. In response to this need, a maturity assessment method based on the smartphone application Maturo has been developed. This study evaluates the accuracy and validity of the Maturo software, an automated tool for estimating biological age and related maturation metrics.Methods: A sample of 103 actively training teenage athletes aged 9-17 years. The sample included 76 males(age = 11.74 ± 1.55 years, mean ±SD) and 27 females(age = 13.95 ± 1.40 years), all without medical conditions that might impact growth or development.Results: Compared to traditional expert evaluations, the intraclass correlation coefficients(ICCs) and Pearson correlation coefficients demonstrated reliable positive correlations and significant agreement between the Maturo software and expert methods across multiple metrics, such as biological age(ICC = 0.965, R = 0.97), corrected biological age(ICC = 0.973, R = 0.99), predicted adult height(ICC = 0.991, R = 0.99), and percentage of adult height achieved(ICC = 0.955, R = 0.97). The Bland-Altman plots provided additional evidence of the validity of the Maturo software estimations, showing low systematic error in most measures. The linear regression analysis produced excellent adjusted R2values: 0.95for biological age and 0.99 for anticipated adult height. The Maturo approach demonstrated a high level of dependability in classifying teenagers into groups based on their maturity status and timing. The κ coefficients of 0.93 for maturity status and 0.82 for maturity timing indicate a nearly perfect agreement with the expert technique.Conclusion: While the Maturo software's non-invasive nature, cost-effectiveness, and ease of use could make it a potential tool for regular monitoring of growth and maturation in young athletes, its promising results in assessing maturation should be interpreted with caution due to limitations such as sample size and demographic constraints. Further longitude research with larger and more diverse populations is needed to validate these preliminary findings and strengthen the evidence for its broader applicability.
基金financed by the Hercules Foundation(project AKUL/13/47)funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 874837+2 种基金supported by the Flemish Government(department of Economy,Science and Innovation)through the Regenerative Medicine Crossing Borders(http://www.regmedxb.com)initiativeImages were recorded on a Zeiss LSM 780-SP Mai Tai HP DS(Cell and Tissue Imaging Cluster(CIC),Supported by Hercules AKUL/11/37 and FWO G.0929.15 to Pieter Vanden Berghe,University of Leuvensupported by Interne Fondsen KU Leuven/Internal Funds KU Leuven grant numbers C24M/22/058.
文摘Clinical translation of tissue-engineered advanced therapeutic medicinal products is hindered by a lack of patient-dependent and independent in-process biological quality controls that are reflective of in vivo outcomes.Recent insights into the mechanism of native bone repair highlight a robust path dependence.Organoid-based bottom-up developmental engineering mimics this pathdependence to design personalized living implants scaffold-free,with in-build outcome predictability.Yet,adequate(noninvasive)quality metrics of engineered tissues are lacking.Moreover,insufficient insight into the role of donor variability and biological sex as influencing factors for the mechanism toward bone repair hinders the implementation of such protocols for personalized bone implants.Here,male and female bone-forming organoids were compared to non-bone-forming organoids regarding their extracellular matrix composition,transcriptome,and secreted proteome signatures to directly link in vivo outcomes to quality metrics.As a result,donor variability in bone-forming callus organoids pointed towards two distinct pathways to bone,through either a hypertrophic cartilage or a fibrocartilaginous template.The followed pathway was determined early,as a biological sexdependent activation of distinct progenitor populations.Independent of donor or biological sex,a cartilage-to-bone transition was driven by a common panel of secreted factors that played a role in extracellular matrix remodeling,mineralization,and attraction of vasculature.Hence,the secreted proteome is a source of noninvasive biomarkers that report on biological potency and could be the missing link toward data-driven decision-making in organoid-based bone tissue engineering.
基金Project (CDJZR12130048) supported by the Fundamental Research Funds for the Central Universities of ChinaProject supported by the Research Council of Norway
文摘Al-x%Sc-0.11%Zr alloys （x=0, 0.02, 0.05, 0.08, 0.11, 0.15） were produced by a chill cast procedure. The effect of Sc content on the precipitation of Al3（Sc,Zr） during heat treatment at 475 °C for 12 h was studied. Nucleation, precipitation and distribution of Al3（Sc,Zr） precipitates were found to be strongly related to the Sc content. With increasing the Sc content, the average radius of the precipitates decreases, while the number density of the precipitates increases, as investigated by transmission electron microscopy （TEM）. The distribution of the precipitates becomes more and more homogeneous when the Sc content is increased. The recrystallization resistance of samples that was 90% cold rolled and isothermal annealed for half an hour in the temperature range of 200-600 °C was investigated. The results show that the recrystallization temperature varies from 250 °C for the alloy without Sc to about 600 °C for the alloy containing 0.15% Sc because of the high density of Al3（Sc,Zr） precipitates.
基金Project (CDJZR12130048) supported by the Fundamental Research Funds for the Central Universities, ChinaProject supported by a Grant from the French Norwegian Foundation for Scientific and Technological Research and Industrial Development
文摘The precipitation behaviours of Al3Zr precipitate in the Al-Cu-Zr and Al-Cu-Zr-Ti-V alloys were studied by transmission electron microscopy. Metastable Al3Zr precipitates are homogeneously nucleated in dendrite centres resulting in homogeneous distribution. However, the precipitation in the interdendritic regions is complex and the precipitation morphologies, helical-like and stripe-like shapes, were observed, which are composed of many spherical Al3Zr precipitates. The stripe-like precipitate clusters have preferential orientations along with the -100- Al directions, which is inferred to be related to θ′（Al2Cu） and θ phases. Addition of Cu can accelerate the L12→D023 structural transformation of the Al3Zr precipitate.
文摘Microplastic contamination has emerged as a threat in transplantation,with evidence of its presence in human tissues and potential to compromise grafts.Transplant recipients,vulnerable due to immunosuppression and surgical exposure,face risk from microplastics via airborne particles,surgical materials,and organ preservation systems.These particles trigger inflammation,oxidative stress,and immune dysregulation—pathways critical in rejection.Microplastics support biofilm formation,potentially facilitating antimicrobial resistance in clinical settings.Despite this risk,transplant-specific research is lacking.We urge action through environmental controls,material substitutions,and procedural modifications,alongside research targeting exposure pathways,biological impact,and mitigation strategies.Transplantation has historically led medical innovation and must do so in confronting this environmental challenge.Leadership from global transplant societies is essential to protect recipients and ensure safe procedures.
基金support from a research university Grant number 1001/PFIZIK/814174 of Universiti Sains Malaysia(USM)
文摘Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.
基金Acknowledgment This work was supported by a grant from the National Nature Science Foundation of China （No. 39970374）. The authors wish to thank Professor Yi-Pong Hu, Second Military Medical University of China, for his kindness in providing us the recombinant plasmid （pBR322-HBV）. We wish to thank Mr. Michael Talion of Shantou University Medical College, English Language Training Section for his assistance in proofreading this manuscript. We gratefully acknowledge the support of the leaders of Shantou University Medical College.
文摘Aim： To detect the expression of hepatitis B virus （HBV） genes （HB S and C genes） in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fertilization （IVF） technique. Methods： Human sperm-mediated HBV genes were delivered into zona-free hamster oocytes by the IVF method. Polymerase chain reaction （PCR） was used to detect HB S and pre-Core/Core （pre-C/C） coding genes both in one- and two-cell embryos. Reverse transcription-PCR （RT-PCR） analysis was used to study the expression of the two genes. Fluorescence in situ hybridization （FISH） analysis using the full-length HBV DNA as the hybridization probe was performed to confirm the integration of viral DNA in the host embryonic genome. Results： Both HB S and pre-C/C coding genes are present and transcribed in one- and two-cell embryos originated from hamster ova IVF with human spermatozoa carrying HBV DNA sequences. Conclusion： Sperm-mediated HBV genes are able to replicate and express themselves in early embryonic cells. These results provide direct evidence that HBV DNA could transmit vertically to the next generation via the male germ line.
基金The study is part of the 1999–2002 research program "Municipal solid waste treatment and compost agriculture application" which is supported jointly by the Tunisian Secretariat of Scientific Research and Technology
文摘The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues （VR） collected from markets of Tunis City with residues of Posidonia oceanica （PoR）, collected from Tunis beaches. The accumulation in beaches （as well as their removal） constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion： （a） C/N ratio 〈 15; （b） NH4^＋-N 〈 400 mg/kg; （c） CO2-C 〈 2000 mg CO2-C/kg; （d） dehydrogenase activity 〈 1 mg TPF/g dry matter; （e） germination index （GI） 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N （13.0 g/kg）, P （4.74 g/kg） and MgO （15.80 g/kg）. Thus composting definitively constitutes the most optimal option to exploit these wastes.
基金supported by the National Natural Science Foundation of China (No. 40805053)
文摘The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units （CRDPF-1 and CRDPF-2） with different specifications were separately retrofitted to the engine running with European steady-state cycle （ESC）. An electrical low pressure impactor （ELPI） was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate （RcR） of hydrocarbons （HC） and carbon monoxide （CO） across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio （A/F） at higher loads.
文摘Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.
