Saccharification of lignocellulosic wastes is the bottleneck of different bio-based chemical industries.Using enzymes for saccharification of lignocellulosic materials has several advantages over using chemicals.In th...Saccharification of lignocellulosic wastes is the bottleneck of different bio-based chemical industries.Using enzymes for saccharification of lignocellulosic materials has several advantages over using chemicals.In the current work,the application of the Maximyze■ enzyme system,which is industrially used in papermaking,was investigated in the saccharification of paper sludge and fiber dust wastes from the tissue paper industry.For optimizing the saccharification process,the effects of the consistency%,enzyme loading,and incubation time were studied and optimized using the Response Surface Methodology.The effect of these factors on the weight loss of paper sludge and total sugars in the hydrolyzate was studied.High-Performance Liquid Chromatography(HPLC)was used to measure the sugars composition of the hydrolyzate.Under the optimized conditions,~90% and~66% of the fiber dust and paper sludge could be hydrolyzed into sugars,respectively.The sugar composition was 80.23% glucose,10.99% xylose,and 8.65% arabinose based on the total sugars in the case of fiber dust.In comparison,80.63% glucose,8.43% xylose,and 10.75% arabinose were detected in the case of paper sludge.The results showed the applicability of the Maximyze Rcommercial enzymes used in the paper industry for efficient saccharification of paper sludge and fiber dust.The presence of non-cellulosic materials in the paper sludge(residual ink,paper additives,and ash)didn’t affect the activity of the enzymes.The study also showed the potential use of fiber dust as a valuable and clean source of sugars that can be used to prepare different bio-based chemicals.展开更多
The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and c...The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and contact time. The removal of Pb（II） reached maximum value 85% or 83% at pH 5 or 40 mg/L of CNTs, respectively. Higher correlation coefficients from Langmuir isotherm model indicates the strong adsorptions of Pb（II） on the surface of CNTs （adsorption capacity Xm = 102.04 mg/g）. The results indicates that the highest percentage removal of Pb （96.03%） can be achieved at pH 5, 40 mg/L of CNTs, contact time 80 min, and agitation speed 50 r/min.展开更多
Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely use...Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely used in food,textile and paper industries;and to a lesser extent in biomedical applications as biomaterial to promote wound healing and tissue regeneration.This is evident from the rising use of alginate-based dressing for heavily exuding wound and their mass availability in the market nowadays.However,alginate also has limitation.When in contact with physiological environment,alginate could gelate into softer structure,consequently limits its potential in the soft tissue regeneration and becomes inappropriate for the usage related to load bearing body parts.To cater this problem,wide range of materials have been added to alginate structure,producing sturdy composite materials.For instance,the incorporation of adhesive peptide and natural polymer or synthetic polymer to alginate moieties creates an improved composite material,which not only possesses better mechanical properties compared to native alginate,but also grants additional healing capability and promote better tissue regeneration.In addition,drug release kinetic and cell viability can be further improved when alginate composite is used as encapsulating agent.In this review,preparation of alginate and alginate composite in various forms(fibre,bead,hydrogel,and 3D-printed matrices)used for biomedical application is described first,followed by the discussion of latest trend related to alginate composite utilization in wound dressing,drug delivery,and tissue engineering applications.展开更多
Owing to the significant increase in air pollutants and the spread of infectious diseases,it seems that the use of face masks will become an essential item in human societies.Therefore,there is a need to conduct more ...Owing to the significant increase in air pollutants and the spread of infectious diseases,it seems that the use of face masks will become an essential item in human societies.Therefore,there is a need to conduct more research to develop novel types of respirators utilizing upto-date science such as nanotechnology.In this study,we fabricated a nanocomposite fibrous filter containing modified graphene oxide(GO)and zinc oxide(ZnO)nanoparticles.This layer was used as an active filter for absorbing and removing air pollutants,such as suspended submicron particles(below 2.5 microns)and CO_(2),NO_(2),and SO_(2)gases.The synthesized nanostructures and fibrous filters were characterized by different analysis(FTIR,XRD,TGA,and FESEM),and the performance of the filters was surveyed by tests such as pressure drop,CO_(2),NO_(2),SO_(2)gas rejection,and particulate removal.The results showed that the stabilization of the modified GO and ZnO nanostructures on the fibrous filter improved the effectiveness of this filter as a mask for removing toxic particles and gases,and the filter containing nanoparticles had the best performance.展开更多
We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semic...We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semiconductors),deposited by simply rubbing powder of these materials against paper.The thermoelectric properties of these semiconducting films revealed maximum Seebeck coefficients of(+1.32±0.27)mV K^(-1)and(-0.82±0.15)mV K^(-1)for WS_(2)and TiS_(3),respectively.Additionally,Peltier elements were fabricated by interconnecting the P-and N-type films with graphite electrodes.A thermopower value up to 6.11 mV K^(-1)was obtained when the Peltier element were constructed with three junctions.The findings of this work show proof-of-concept devices to illustrate the potential application of semiconducting van der Waals materials in future thermoelectric power generation as well as temperature sensing for low-cost disposable electronic devices.展开更多
Evolution of H_(2)upon catalytic hydrolysis of inorganic hydrides is a key method for clean energy pro-duction.Here,a new organocobalt precursor is used to generate nanocatalysts that are efficient,stable and recyclab...Evolution of H_(2)upon catalytic hydrolysis of inorganic hydrides is a key method for clean energy pro-duction.Here,a new organocobalt precursor is used to generate nanocatalysts that are efficient,stable and recyclable.The cobalt complexes[Co(η^(5)-C_(5)H_(5))(η^(4)-C_(5)H_(6))],1,and[Co(η^(5)-C_(5)Me_(5))(η^(4)-C_(5)H_(6))],2,are used to reduce late transition metal chlorides to a series of late transition metal nanoparticles,abbreviated TMNP and TMNP^(*),respectively,that catalyse hydrolysis of B_(2)(OH)_(4)and ammonia borane(AB).Among the prepared TMNP and TMNP^(*),the latter are found to be the most efficient and recyclable catalysts,showing,with RhNP^(*),TOFs of 1364 mol_(H_(2))mol_(cat)^(−1)min^(−1)in B2(OH)4 hydrolysis and 125 mol_(H_(2))mol_(cat)^(−1)min^(−1)in AB hydrolysis at a low catalyst loading of 0.2 mol%.The kinetic study including kinetic isotope effect leads to a proposed mechanism of the RhNP^(*)-catalysed AB hydrolysis involving water O-H bond oxi-dative addition on the catalyst surface as the rate-limiting step for H_(2)generation.展开更多
Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules t...Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules though silane chemistry or electrostatic interactions,while retaining open access to MOF porosity.Silica coating would be highly beneficial for employing MOFs in a wide range of applications such as catalysis or drug delivery.However,obtaining a stable,controlled core–shell structure using MOF nanoparticles as seeds is challenging because of their intrinsic chemically labile nature.Here we analyze the factors that destabilize the core of the Zeolitic Imidazolate Framework-8(ZIF-8)MOFs during the sol–gel deposition of a mesoporous silica shell causing a partial or total etching of the MOF material.Silicates in solution are found to scavenge Zn^(2+)ions removing them from the ZIF structure and causing a partial or complete dissolution of the ZIF seed.By carefully tuning the silicate concentration in solution simultaneous control can be obtained over both the ZIF-8 dissolution and the silica condensation kinetics,resulting in the growth of a uniform mesoporous silica shell while preserving the integrity of ZIF-8.The core–shell nanoparticles obtained show a compact core shell structure with no gap between the MOF core and the silica shell,even after calcination,while the crystalline ZIF-8 structure is retained.Overall,a general synthetic approach is presented for producing nanocomposite core–shell materials which can be applied to other MOF labile seeds to design new hierarchical materials.展开更多
Objective:This study engineers leaflet-and 3-dimensional(3D)printing-based implant prototypes for infant mitral valve repair via in vitro cultured mesoangioblasts isolated from the human fetal aorta(AoMAB).Impact Stat...Objective:This study engineers leaflet-and 3-dimensional(3D)printing-based implant prototypes for infant mitral valve repair via in vitro cultured mesoangioblasts isolated from the human fetal aorta(AoMAB).Impact Statement:Ultrahigh-molecular-weight polyethylene(UHMWPE)coatings,as well as 3D-printed gelatin methacrylate(GelMA)hydrogels for implants,represent new possibilities for devices used in mitral valve repair.Introduction:Mitral valve prolapse(MVP)repair in pediatric patients is challenging due to somatic growth,patient–prosthesis mismatch,reinterventions,infections,and thromboembolism.Tissue-engineered heart valves(TEHVs)offer potential solutions through conventional and 3D printing biofabrication.Methods:Four materials are evaluated:UHMWPE,UHMWPE coated with polyvinyl alcohol(PVA),UHMWPE coated with PVA and collagen,and 3D-printed GelMA hydrogels.The prototypes are characterized for micro/nanostructural,physicochemical(degradation,contact angle,Fourier transform infrared spectroscopy),and mechanical properties(simple strength tests,dynamic mechanical analysis)and assessed for cytocompatibility using AoMAB cells.A 3D printing mitral valve prototype is analyzed via immunostaining.Results:Results highlight UHMWPE coated with PVA and collagen as the most promising,with degradation(7.30±18.71%),a hydrophilic contact angle(26.13±1.45°),and biocompatibility(177.04±68.92%viability).GelMA prototypes show superior viability(216.77±77.69%)and scalability for 3D printing.Conclusion:UHMWPE coated with PVA and collagen and GelMA demonstrate strong potential for TEHVs,with AoMAB cells facilitating 3D culture and future personalized pediatric applications.Further in vitro validation and thrombogenicity assessments are needed.展开更多
Hyaluronic acid(HA)hydrogels,obtained through cross-linking,provide a stable 3D environment that is important for controlled delivery and tissue engineering applications.Cross-linking density has a significant impact ...Hyaluronic acid(HA)hydrogels,obtained through cross-linking,provide a stable 3D environment that is important for controlled delivery and tissue engineering applications.Cross-linking density has a significant impact on the physicochemical properties of hydrogels,including their shape stability,mechanical stiffness and macromolecular diffusivity.However,often cross-linking chemistries require photoinitiator and catalyst that may be toxic and cause unwanted tissue response.Here,we prepared a series of HA hydrogel with varying crosslinker length and cross-linking density,which can be obtained by altering the feed ratio of three different crosslinkers from small molecules to macromolecules(e.g.,1,4-butanediol diglycidyl ether(BDDE),ferulic acid(FA),pluronic(PLU)),to ameliorate skin wrinkles in mice models.HA cross-linked with FA and PLU exhibited enzyme and temperature-dependent sol-to-gel phase transition,respectively,and the gels possess good injectability.In vitro test confirmed that HA hydrogels co-cultured with RAW 264.7 and HDF cells showed good biocompati-bility.In particular,HA cross-linked with PLU stimulated the growth of HDF cells and HaCaT cells.HA crosslinked with PLU suppressed the expression levels of proteins involved in collagen degradation including mitogen-activated protein kinases(ERK,JNK,p38)and matrix metalloproteases(MMP-1,MMP-3,and MMP-9)resulting in increased deposition of Collagen I.The free-flowing sols of HA hydrogel precursors are subcutane-ously injected into the back of BALB/c mice and form stable gels at the dermis layer and found to be non-toxic.More importantly,HA hydrogel cross-linked with PLU showed an enhanced anti-wrinkling effect in the wrinkled mice model.Thus,properties of HA hydrogels such as injectability,biocompatibility,and good anti-wrinkling effect altered through varying cross-linking density must be considered in the context of soft tissue engineer-ing applications.展开更多
Enzymatic biofuel cells promise green power generation from a variety of natural resources, yet these systems all suffer from time-dependent degradati on effects, in particular progress! ng inactivation of enzymes, wh...Enzymatic biofuel cells promise green power generation from a variety of natural resources, yet these systems all suffer from time-dependent degradati on effects, in particular progress! ng inactivation of enzymes, which severely limit the operati on al lifetimes of such power sources. To extend operational lifetimes, we introduce a method to magnetically exchange exhausted enzymes for fresh ones. To this end, anodic and cathodic enzymes or enzyme cascades are immobilized on carbon coated magnetic nanoparticles. Under the action of suitable magnetic field gradie nts, these nano particles are assembled on the respective stati onary electrodes, or released from the electrodes for collection and subsequent excha nge. We dem on strate this method on a fructose/oxygen con suming biofuel cell emplo ying fructose dehydroge nase and bilirubin oxidase as well as on anodic and cathodic cascades employing fructose dehydrogenase/invertase and bilirubin oxidase/catalase, respectively. The en zyme-modified nan oparticles support direct electro n transfer bioelectrocatalytic curre nts by wiring the redox active cofactors to the carbonaceous coating and from there to the electrode surfaces. The facile injection, assembly, and removal of enzyme-modified magnetic nan oparticles along with fuel solutio n provides a promisi ng approach to exte nd the operati on al lifetime of enzymatic biofuel cells without the need for exchanging entire systems including chambers and electrodes.展开更多
Continuous usage of bioreactor causes early degradation of most bioreactor liner materials due to the effects of various chemicals, consequently resulting in contamination in the bioprocess. Performance of PP-ternary ...Continuous usage of bioreactor causes early degradation of most bioreactor liner materials due to the effects of various chemicals, consequently resulting in contamination in the bioprocess. Performance of PP-ternary nanocomposite (PPTN) for its potential application in the fabrication of bioreactor liner material was investigated in this study. The chemical resistance of the composite samples obtained was tested by exposing them to chemicals such as acid, alkaline, water and bacterial solutions, according to ASTM 543-06, and their effects on the composite samples were carefully observed. Specifically, the investigation focused on the changes in the physico-mechanical properties of PPTN following long term of exposure to these chemicals. The results show slight increase in the weight and dimensions of samples in the first few days, followed by constant reading for the period of 4 weeks. The performance in terms of physical properties was in the range of PPTN with 0.61% MWCNT > PPTN 0.45% > PPTN 0.17%. The maximum percentage change in tensile properties, observed in this study, was approximately 10% against PPTN (0.17%), which indicates stable mechanical properties of the composite and invariably suggests that the nanocomposites could serve as a better alternative for bioreactor liner fabrication.展开更多
In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and high-sensitivity.Such features are essential to enable...In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and high-sensitivity.Such features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and security.However,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic resistances.In this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFET detectors.Such dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,respectively.Our results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical calculations.These findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.展开更多
Direct application of bio-oil from fast pyrolysis as a fuel has remained a challenge due to its undesirable attributes such as low heating value,high viscosity,high corrosiveness and storage instability.Solvent additi...Direct application of bio-oil from fast pyrolysis as a fuel has remained a challenge due to its undesirable attributes such as low heating value,high viscosity,high corrosiveness and storage instability.Solvent addition is a simple method for circumventing these disadvantages to allow further processing and storage.In this work,computer-aided molecular design tools were developed to design optimal solvents to upgrade bio-oil whilst having low environmental impact.Firstly,target solvent requirements were translated into measurable physical properties.As different property prediction models consist different levels of structural information,molecular signature descriptor was used as a common platform to formulate the design problem.Because of the differences in the required structural information of different property prediction models,signatures of different heights were needed in formulating the design problem.Due to the combinatorial nature of higher-order signatures,the complexity of a computer-aided molecular design problem increases with the height of signatures.Thus,a multi-stage framework was developed by developing consistency rules that restrict the number of higher-order signatures.Finally,phase stability analysis was conducted to evaluate the stability of the solvent-oil blend.As a result,optimal solvents that improve the solvent-oil blend properties while displaying low environmental impact were identified.展开更多
We present a low-cost and easy-to-implement technique to fabricate large-area WS_(2) photodetector devices onto transparent and flexible polycarbonate substrates.The method relies on the deposition of large-area(in th...We present a low-cost and easy-to-implement technique to fabricate large-area WS_(2) photodetector devices onto transparent and flexible polycarbonate substrates.The method relies on the deposition of large-area(in the cm scale)thin films(~30 nm thick)of WS_(2) by a recently introduced abrasion-induced method.Interdigitated electrical contacts are then deposited by thermal evaporation through a shadow mask.The photodetectors present well-balanced performances with an good trade-off between responsivity(up to 144 mA/W at a source-drain voltage of 10 V and illumination power of 1μW)and response time(down to~70µs)and a detectivity value of 10^(8) Jones.We found that the devices perform very reversibly upon several illumination and straining cycles and we found a moderate device-to-device variation.展开更多
Emerging contaminants like metal nanoparticles get introduced into soil through different routes.Toxic effects of these contaminants on plant growth-promoting bacteria(PGPB),which influence plant productivity,can be d...Emerging contaminants like metal nanoparticles get introduced into soil through different routes.Toxic effects of these contaminants on plant growth-promoting bacteria(PGPB),which influence plant productivity,can be detrimental to soil health.Titanium dioxide is one of the most produced nanomaterials in the world and therefore potentially the most released nanoform in soil.The objective of this study was to evaluate the toxic effects of titanium dioxide nanoparticles(TiO2 NPs)on plant growth-promoting bacteria.Three types of PGPB,viz.,nitrogen fixers,phosphate solubilizers and biofilm formers were exposed to TiO2 NPs.Our results suggest that direct contact of the bacteria with these NPs is inhibitory as compared to when these bacteria are growing in laboratory nutrient media in the presence of NPs.The inhibitory effect did not follow a linear dose response but instead showed a pronounced step response.Soils with their varying characteristics may not afford the same protection to bacteria as laboratory nutrient media and thus TiO2 NPs may cause some sensitive PGPB to disappear from soil.The resultant shift in bacterial community composition may affect ecosystem functioning.展开更多
In simulations of fluidized beds using computational fluid dynamics （CFD）, the description of gas-solid flow hydrodynamics relies on a drag model to account for the momentum transfer between gas and solid phases. Al...In simulations of fluidized beds using computational fluid dynamics （CFD）, the description of gas-solid flow hydrodynamics relies on a drag model to account for the momentum transfer between gas and solid phases. Although several studies of drag models have been published, there have been few investigations of the application of lattice Boltzmann method （LBM）-based drag models to bubbling fluidized bed simu- lations. In the present study, a comprehensive comparison of empirical and LBM-based drag models was carried out to assess the performance of these models during simulations of gas-solid flow hydrodynam- ics in a bubbling fluidized bed. A CFD model using the MFIX code based on the Eulerian-Eulerian approach and the kinetic theory of granular flow was used to simulate a 2D bubbling fluidized bed with Geldart B particles. The simulation results were validated by comparison with experimental data. Statistical anal- ysis of the results shows that LBM-based drag models can reliably model gas-solid flow hydrodynamics in a bubbling fluidized bed.展开更多
Trapping and manipulation of nano-objects in solution are of great interest and have emerged in a plethora of fields spanning from soft condensed matter to biophysics and medical diagnostics.We report on establishing ...Trapping and manipulation of nano-objects in solution are of great interest and have emerged in a plethora of fields spanning from soft condensed matter to biophysics and medical diagnostics.We report on establishing a nanofluidic system for reliable and contact-free trapping as well as manipulation of charged nano-objects using elastic polydimethylsiloxane(PDMS)-based materials.This trapping principle is based on electrostatic repulsion between charged nanofluidic walls and confined charged objects,called geometry-induced electrostatic(GIE)trapping.With gold nanoparticles as probes,we study the performance of the devices by measuring the stiffness and potential depths of the implemented traps,and compare the results with numerical simulations.When trapping 100 nm particles,we observe potential depths of up to Q≅24 k_(B)T that provide stable trapping for many days.Taking advantage of the soft material properties of PDMS,we actively tune the trapping strength and potential depth by elastically reducing the device channel height,which boosts the potential depth up to Q~200 k_(B)T,providing practically permanent contactfree trapping.Due to a high-throughput and low-cost fabrication process,ease of use,and excellent trapping performance,our method provides a reliable platform for research and applications in study and manipulation of single nano-objects in fluids.展开更多
The contamination of the environment by organic pollutants is a major risk factor,particularly for developing countries.Selected organic pollutants(SOPs)like the phenolic compounds,polyaromatic hydrocarbons(PAHs),pest...The contamination of the environment by organic pollutants is a major risk factor,particularly for developing countries.Selected organic pollutants(SOPs)like the phenolic compounds,polyaromatic hydrocarbons(PAHs),pesticides,and herbicides pose serious environmental and health issues owing to their toxic characteristics and poor degradability.Apart from their potential mutagenicity,carcinogenicity,tetragenicity and high body accumulation,these pollutants have become an increase concern worldwide.Biosorption is a promising alternative strategy for removing organic pollutants during water purification processes.Biosorbents have several advantages such as simplicity of operation,good sorption capacity,high recoverability and modifiability.As a result,the focus and novelty of this review is on recent trends in the use of biosorbents,with a particular emphasis on the removal of SOPs from wastewater.It also cover use of bacteria biosorbents,fungal,algae and chitosan/chitin biosorbents.Apart from that,we have also reviewed various classes of SOPs,their levels in the environment,classification and available characteristics techniques suitable for the adsorption experiments of these nanocomposites materials.In addition,we have provided comprehensive explanations and conclusions on possible future application of biosorbents and the mechanism of adsorption of these materials for removal of these SOPs from wastewater during water purification processes.展开更多
In recent years,a lot of research has been done on silver nanoparticles(SNP)due to their numerous applications in the biomedical,pharmaceutical,and drug delivery industries.In this present study SNP were green synthes...In recent years,a lot of research has been done on silver nanoparticles(SNP)due to their numerous applications in the biomedical,pharmaceutical,and drug delivery industries.In this present study SNP were green synthesized using Melicope lunu-ankenda(M.lunu-ankenda)leaf extract.The addition of AgNO3 causes a color change.L-arginine addition results in further colour changes confirming conjugation.A UV–Vis spectrophotometric examination showed that the absorption peak for SNP was 435 nm,while the peak for L-arginine SNP(cSNP)was 422 nm.FTIR analysis confirmed the association of amides and amines with nanoparticles.The spherical nature of the silver was disclosed by SEM,and its elemental character is verified by EDS.The thermal stability of the nanoparticles is determined by TGA analysis,while TEM examination verifies their spherical shape.Using the MTT assay,these cSNP exhibited outstanding toxicity analysis(IC5038.72μg/ml)against MDA-MB-231 cells.These cSNP causes damage to the mitochondria(JC1 staining),which causes oxidative stress and the production of ROS with 83%of DCF expression in cancer cells.Furthermore,as demonstrated by the Comet assay and DAPI,these cSNP cause good DNA damage in the treated cells.Additionally,using flow cytometry,cSNPs potentially trigger apoptosis by triggering the expression of caspase 3 and caspase 8 proteins.Additionally,through CAM,cSNP demonstrated strong anti-angiogenesis activity by reducing the number of blood vessel branches.These findings suggest that cSNP may be crucial for drug delivery and cancer treatment.展开更多
Boron-doped biochar(B-BC)was synthesized by pyrolysis using solid waste of sorghum straw as raw material.The specific surface area of B-BC increased significantly by 2.38 times compared to that of pure BC.This enhance...Boron-doped biochar(B-BC)was synthesized by pyrolysis using solid waste of sorghum straw as raw material.The specific surface area of B-BC increased significantly by 2.38 times compared to that of pure BC.This enhancement allowed B-BC(0.3 g L^(−1))to achieve complete adsorption of 10 mg L^(−1)tartrazine(TTZ)within 40 min.Moreover,acidic conditions were more favorable for TTZ adsorption,achieving complete removal of TTZ in only 15 min at a pH of 3.0.Interestingly,the adsorption rate of TTZ by B-BC in the presence of 0.05 M Cl^(-)was approximately 2.12 times higher than that in the absence of Cl^(-).When other background electrolytes were present,excluding PO_(4)^(3−),complete adsorption of TTZ could also be achieved within 60 min.Thermodynamic analysis and DFT calculations described the parameters of B-BC for TTZ adsorption,includingG(<0 kJ mol^(−1)),H(−2.199 kJ mol^(−1)),S(−6.068 J mol^(−1)K^(−1)),and the adsorption energy(E_(ads)=−0.6919 eV),indicating a tendency towards a spontaneous adsorption process.Moreover,the strong electron transfer ability of B-BC and the oxygen-containing groups promoted the activation of PDS and generation of active substances such as^(1)O_(2),O_(2)^(•−),and SO_(4)^(•−),thereby degrading TTZ into products with lower biological toxicity.When the added PDS was only 0.1 mM,the degradation rate constant of TTZ could reach 0.1481 min−1.Furthermore,boron doping enhanced the stability of biochar,enabling the complete removal of 10 mg L^(−1)TTZ even after recycling and regeneration.In summary,this study offers a practical solution for the resource utilization of solid waste sorghum straw and the treatment of TTZ-polluted wastewater.展开更多
基金funding of the current work by the Science,Technology,and Innovation Funding Authority(STDF),Egypt,project no.46104:“Recycling of sludge wastes from paper industry via green technologies”.
文摘Saccharification of lignocellulosic wastes is the bottleneck of different bio-based chemical industries.Using enzymes for saccharification of lignocellulosic materials has several advantages over using chemicals.In the current work,the application of the Maximyze■ enzyme system,which is industrially used in papermaking,was investigated in the saccharification of paper sludge and fiber dust wastes from the tissue paper industry.For optimizing the saccharification process,the effects of the consistency%,enzyme loading,and incubation time were studied and optimized using the Response Surface Methodology.The effect of these factors on the weight loss of paper sludge and total sugars in the hydrolyzate was studied.High-Performance Liquid Chromatography(HPLC)was used to measure the sugars composition of the hydrolyzate.Under the optimized conditions,~90% and~66% of the fiber dust and paper sludge could be hydrolyzed into sugars,respectively.The sugar composition was 80.23% glucose,10.99% xylose,and 8.65% arabinose based on the total sugars in the case of fiber dust.In comparison,80.63% glucose,8.43% xylose,and 10.75% arabinose were detected in the case of paper sludge.The results showed the applicability of the Maximyze Rcommercial enzymes used in the paper industry for efficient saccharification of paper sludge and fiber dust.The presence of non-cellulosic materials in the paper sludge(residual ink,paper additives,and ash)didn’t affect the activity of the enzymes.The study also showed the potential use of fiber dust as a valuable and clean source of sugars that can be used to prepare different bio-based chemicals.
基金the Kulliyyah of Engineering(KOE) and Department of Biotechnology Engineering,IIUM for supporting and providing the laboratory facilities
文摘The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and contact time. The removal of Pb（II） reached maximum value 85% or 83% at pH 5 or 40 mg/L of CNTs, respectively. Higher correlation coefficients from Langmuir isotherm model indicates the strong adsorptions of Pb（II） on the surface of CNTs （adsorption capacity Xm = 102.04 mg/g）. The results indicates that the highest percentage removal of Pb （96.03%） can be achieved at pH 5, 40 mg/L of CNTs, contact time 80 min, and agitation speed 50 r/min.
基金The authors acknowledge the financial support received from Ministry of Education Malaysia(FRGS/1/2018/TK05/UIAM/03/3).Writing on fibre preparation,chitin,and chitosan are directly related to the said grant.
文摘Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely used in food,textile and paper industries;and to a lesser extent in biomedical applications as biomaterial to promote wound healing and tissue regeneration.This is evident from the rising use of alginate-based dressing for heavily exuding wound and their mass availability in the market nowadays.However,alginate also has limitation.When in contact with physiological environment,alginate could gelate into softer structure,consequently limits its potential in the soft tissue regeneration and becomes inappropriate for the usage related to load bearing body parts.To cater this problem,wide range of materials have been added to alginate structure,producing sturdy composite materials.For instance,the incorporation of adhesive peptide and natural polymer or synthetic polymer to alginate moieties creates an improved composite material,which not only possesses better mechanical properties compared to native alginate,but also grants additional healing capability and promote better tissue regeneration.In addition,drug release kinetic and cell viability can be further improved when alginate composite is used as encapsulating agent.In this review,preparation of alginate and alginate composite in various forms(fibre,bead,hydrogel,and 3D-printed matrices)used for biomedical application is described first,followed by the discussion of latest trend related to alginate composite utilization in wound dressing,drug delivery,and tissue engineering applications.
文摘Owing to the significant increase in air pollutants and the spread of infectious diseases,it seems that the use of face masks will become an essential item in human societies.Therefore,there is a need to conduct more research to develop novel types of respirators utilizing upto-date science such as nanotechnology.In this study,we fabricated a nanocomposite fibrous filter containing modified graphene oxide(GO)and zinc oxide(ZnO)nanoparticles.This layer was used as an active filter for absorbing and removing air pollutants,such as suspended submicron particles(below 2.5 microns)and CO_(2),NO_(2),and SO_(2)gases.The synthesized nanostructures and fibrous filters were characterized by different analysis(FTIR,XRD,TGA,and FESEM),and the performance of the filters was surveyed by tests such as pressure drop,CO_(2),NO_(2),SO_(2)gas rejection,and particulate removal.The results showed that the stabilization of the modified GO and ZnO nanostructures on the fibrous filter improved the effectiveness of this filter as a mask for removing toxic particles and gases,and the filter containing nanoparticles had the best performance.
基金funded by the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation program(grant agreement no.755655,ERC-StG 2017 project 2D-TOPSENSE)the Ministry of Science and Innovation(Spain)through the project PID2020-115566RB-I00+7 种基金the Distinguished Scientist Fellowship Program(DSFP)at King Saud University for partial funding of this workfinancial support from the Agencia Estatal de Investigación of Spain(Grants PID2019-106820RB,RTI2018-097180-B-100,and PGC2018-097018-B-I00)the Junta de Castilla y León(Grants SA256P18 and SA121P20),including funding by ERDF/FEDERfinancial support from Universidad Complutense de Madrid and European Commission(MSCA COFUND UNA4CAREER grant.Project number 4129252)financial support from MICINN(Spain)through the program Juan de la Cierva-Incorporaciónthe financial support of the Spanish Ministry of Industry and Competitiveness to the project MAT2017-84496-Rfinancial support from the Ministry of Science and Innovation(Spain)through the project RT2018-099794-B-100financial support from the Ministry de Universities(Spain)(Ph.D.contract FPU19/04224)
文摘We present a method to fabricate handcrafted thermoelectric devices on standard office paper substrates.The devices are based on thin films of WS_(2),Te,and BP(P-type semiconductors)and TiS_(3)and TiS_(2)(N-type semiconductors),deposited by simply rubbing powder of these materials against paper.The thermoelectric properties of these semiconducting films revealed maximum Seebeck coefficients of(+1.32±0.27)mV K^(-1)and(-0.82±0.15)mV K^(-1)for WS_(2)and TiS_(3),respectively.Additionally,Peltier elements were fabricated by interconnecting the P-and N-type films with graphite electrodes.A thermopower value up to 6.11 mV K^(-1)was obtained when the Peltier element were constructed with three junctions.The findings of this work show proof-of-concept devices to illustrate the potential application of semiconducting van der Waals materials in future thermoelectric power generation as well as temperature sensing for low-cost disposable electronic devices.
基金support from the China Scholarship Council(CSC,PhD grants to Q.Z.and N.K.)the PID2020-114356RB-I00 Retos Project from the Ministerio de Economía,Industria y Competitividad,gobierno de España(S.M.),the Centre National de la Recherche Scientifique(CNRS)the University of Bordeaux is gratefully acknowledged.
文摘Evolution of H_(2)upon catalytic hydrolysis of inorganic hydrides is a key method for clean energy pro-duction.Here,a new organocobalt precursor is used to generate nanocatalysts that are efficient,stable and recyclable.The cobalt complexes[Co(η^(5)-C_(5)H_(5))(η^(4)-C_(5)H_(6))],1,and[Co(η^(5)-C_(5)Me_(5))(η^(4)-C_(5)H_(6))],2,are used to reduce late transition metal chlorides to a series of late transition metal nanoparticles,abbreviated TMNP and TMNP^(*),respectively,that catalyse hydrolysis of B_(2)(OH)_(4)and ammonia borane(AB).Among the prepared TMNP and TMNP^(*),the latter are found to be the most efficient and recyclable catalysts,showing,with RhNP^(*),TOFs of 1364 mol_(H_(2))mol_(cat)^(−1)min^(−1)in B2(OH)4 hydrolysis and 125 mol_(H_(2))mol_(cat)^(−1)min^(−1)in AB hydrolysis at a low catalyst loading of 0.2 mol%.The kinetic study including kinetic isotope effect leads to a proposed mechanism of the RhNP^(*)-catalysed AB hydrolysis involving water O-H bond oxi-dative addition on the catalyst surface as the rate-limiting step for H_(2)generation.
基金the Ministry of Research and Innovation of Spain for support through the PID2020-114356RB-I00 Retos projectthe Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency-Grant No.MDM-2017-0720.
文摘Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules though silane chemistry or electrostatic interactions,while retaining open access to MOF porosity.Silica coating would be highly beneficial for employing MOFs in a wide range of applications such as catalysis or drug delivery.However,obtaining a stable,controlled core–shell structure using MOF nanoparticles as seeds is challenging because of their intrinsic chemically labile nature.Here we analyze the factors that destabilize the core of the Zeolitic Imidazolate Framework-8(ZIF-8)MOFs during the sol–gel deposition of a mesoporous silica shell causing a partial or total etching of the MOF material.Silicates in solution are found to scavenge Zn^(2+)ions removing them from the ZIF structure and causing a partial or complete dissolution of the ZIF seed.By carefully tuning the silicate concentration in solution simultaneous control can be obtained over both the ZIF-8 dissolution and the silica condensation kinetics,resulting in the growth of a uniform mesoporous silica shell while preserving the integrity of ZIF-8.The core–shell nanoparticles obtained show a compact core shell structure with no gap between the MOF core and the silica shell,even after calcination,while the crystalline ZIF-8 structure is retained.Overall,a general synthetic approach is presented for producing nanocomposite core–shell materials which can be applied to other MOF labile seeds to design new hierarchical materials.
基金support from the Federal Commission for Scholarships for Foreign Students for the Swiss Government Excellence Scholarships(ESKAS No.2023.0458)for the academic year 2023–2024all the authors acknowledge HEPIA for funding the materials.
文摘Objective:This study engineers leaflet-and 3-dimensional(3D)printing-based implant prototypes for infant mitral valve repair via in vitro cultured mesoangioblasts isolated from the human fetal aorta(AoMAB).Impact Statement:Ultrahigh-molecular-weight polyethylene(UHMWPE)coatings,as well as 3D-printed gelatin methacrylate(GelMA)hydrogels for implants,represent new possibilities for devices used in mitral valve repair.Introduction:Mitral valve prolapse(MVP)repair in pediatric patients is challenging due to somatic growth,patient–prosthesis mismatch,reinterventions,infections,and thromboembolism.Tissue-engineered heart valves(TEHVs)offer potential solutions through conventional and 3D printing biofabrication.Methods:Four materials are evaluated:UHMWPE,UHMWPE coated with polyvinyl alcohol(PVA),UHMWPE coated with PVA and collagen,and 3D-printed GelMA hydrogels.The prototypes are characterized for micro/nanostructural,physicochemical(degradation,contact angle,Fourier transform infrared spectroscopy),and mechanical properties(simple strength tests,dynamic mechanical analysis)and assessed for cytocompatibility using AoMAB cells.A 3D printing mitral valve prototype is analyzed via immunostaining.Results:Results highlight UHMWPE coated with PVA and collagen as the most promising,with degradation(7.30±18.71%),a hydrophilic contact angle(26.13±1.45°),and biocompatibility(177.04±68.92%viability).GelMA prototypes show superior viability(216.77±77.69%)and scalability for 3D printing.Conclusion:UHMWPE coated with PVA and collagen and GelMA demonstrate strong potential for TEHVs,with AoMAB cells facilitating 3D culture and future personalized pediatric applications.Further in vitro validation and thrombogenicity assessments are needed.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(NRF-2023R1A2C1005904).
文摘Hyaluronic acid(HA)hydrogels,obtained through cross-linking,provide a stable 3D environment that is important for controlled delivery and tissue engineering applications.Cross-linking density has a significant impact on the physicochemical properties of hydrogels,including their shape stability,mechanical stiffness and macromolecular diffusivity.However,often cross-linking chemistries require photoinitiator and catalyst that may be toxic and cause unwanted tissue response.Here,we prepared a series of HA hydrogel with varying crosslinker length and cross-linking density,which can be obtained by altering the feed ratio of three different crosslinkers from small molecules to macromolecules(e.g.,1,4-butanediol diglycidyl ether(BDDE),ferulic acid(FA),pluronic(PLU)),to ameliorate skin wrinkles in mice models.HA cross-linked with FA and PLU exhibited enzyme and temperature-dependent sol-to-gel phase transition,respectively,and the gels possess good injectability.In vitro test confirmed that HA hydrogels co-cultured with RAW 264.7 and HDF cells showed good biocompati-bility.In particular,HA cross-linked with PLU stimulated the growth of HDF cells and HaCaT cells.HA crosslinked with PLU suppressed the expression levels of proteins involved in collagen degradation including mitogen-activated protein kinases(ERK,JNK,p38)and matrix metalloproteases(MMP-1,MMP-3,and MMP-9)resulting in increased deposition of Collagen I.The free-flowing sols of HA hydrogel precursors are subcutane-ously injected into the back of BALB/c mice and form stable gels at the dermis layer and found to be non-toxic.More importantly,HA hydrogel cross-linked with PLU showed an enhanced anti-wrinkling effect in the wrinkled mice model.Thus,properties of HA hydrogels such as injectability,biocompatibility,and good anti-wrinkling effect altered through varying cross-linking density must be considered in the context of soft tissue engineer-ing applications.
文摘Enzymatic biofuel cells promise green power generation from a variety of natural resources, yet these systems all suffer from time-dependent degradati on effects, in particular progress! ng inactivation of enzymes, which severely limit the operati on al lifetimes of such power sources. To extend operational lifetimes, we introduce a method to magnetically exchange exhausted enzymes for fresh ones. To this end, anodic and cathodic enzymes or enzyme cascades are immobilized on carbon coated magnetic nanoparticles. Under the action of suitable magnetic field gradie nts, these nano particles are assembled on the respective stati onary electrodes, or released from the electrodes for collection and subsequent excha nge. We dem on strate this method on a fructose/oxygen con suming biofuel cell emplo ying fructose dehydroge nase and bilirubin oxidase as well as on anodic and cathodic cascades employing fructose dehydrogenase/invertase and bilirubin oxidase/catalase, respectively. The en zyme-modified nan oparticles support direct electro n transfer bioelectrocatalytic curre nts by wiring the redox active cofactors to the carbonaceous coating and from there to the electrode surfaces. The facile injection, assembly, and removal of enzyme-modified magnetic nan oparticles along with fuel solutio n provides a promisi ng approach to exte nd the operati on al lifetime of enzymatic biofuel cells without the need for exchanging entire systems including chambers and electrodes.
基金the Malaysia Ministry of Higher Education (MOHE) for funding this project under FRGS 0206-56
文摘Continuous usage of bioreactor causes early degradation of most bioreactor liner materials due to the effects of various chemicals, consequently resulting in contamination in the bioprocess. Performance of PP-ternary nanocomposite (PPTN) for its potential application in the fabrication of bioreactor liner material was investigated in this study. The chemical resistance of the composite samples obtained was tested by exposing them to chemicals such as acid, alkaline, water and bacterial solutions, according to ASTM 543-06, and their effects on the composite samples were carefully observed. Specifically, the investigation focused on the changes in the physico-mechanical properties of PPTN following long term of exposure to these chemicals. The results show slight increase in the weight and dimensions of samples in the first few days, followed by constant reading for the period of 4 weeks. The performance in terms of physical properties was in the range of PPTN with 0.61% MWCNT > PPTN 0.45% > PPTN 0.17%. The maximum percentage change in tensile properties, observed in this study, was approximately 10% against PPTN (0.17%), which indicates stable mechanical properties of the composite and invariably suggests that the nanocomposites could serve as a better alternative for bioreactor liner fabrication.
基金support from the Ministry of Science and Innovation(MCIN)and the Spanish State Research Agency(AEI)under grants(PID2021-126483OB-I00,PID2021-128154NA-I00 and PID2022-136285NB-C32)funded by MICIU/AEI/https://doi.org/10.13039/501100011033 and by“ERDF A way of making Europe.”This work has been also supported by Junta de Castilla y Leon co-funded by FEDER under the Research Grant numbers SA103P23 and SA106P23+3 种基金KW and TT acknowledge support from the JSPS KAKENHI(Grant Numbers 21H05233 and 23H02052)and World Premier International Research Center Initiative(WPI),MEXT,JapanJMC acknowledges financial support by the MCIN and AEI“Ramon y Cajal”program(RYC2019-028443-I)funded by MICIU/AEI/https://doi.org/10.13039/501100011033 and by“ESF Investing in Your Future.”JMC also acknowledges financial of the European Research Council(ERC)under Starting grant ID 101039754,CHIROTRONICS,funded by the European UnionJAD-N thanks the support from the Universidad de Salamanca for the Maria Zambrano postdoctoral grant funded by the Next Generation EU Funding for the Requalification of the Spanish University System 2021-23,Spanish Ministry of Universities.ies.
文摘In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and high-sensitivity.Such features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and security.However,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic resistances.In this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFET detectors.Such dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,respectively.Our results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical calculations.These findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.
基金The authors would like to express sincere gratitude to Ministry of Higher Education Malaysia for the realization of this research project under the Grant FRGS/1/2019/TK02/UNIM/02/1However,only the authors are responsible for the opinion expressed in this paper and for any remaining errors.
文摘Direct application of bio-oil from fast pyrolysis as a fuel has remained a challenge due to its undesirable attributes such as low heating value,high viscosity,high corrosiveness and storage instability.Solvent addition is a simple method for circumventing these disadvantages to allow further processing and storage.In this work,computer-aided molecular design tools were developed to design optimal solvents to upgrade bio-oil whilst having low environmental impact.Firstly,target solvent requirements were translated into measurable physical properties.As different property prediction models consist different levels of structural information,molecular signature descriptor was used as a common platform to formulate the design problem.Because of the differences in the required structural information of different property prediction models,signatures of different heights were needed in formulating the design problem.Due to the combinatorial nature of higher-order signatures,the complexity of a computer-aided molecular design problem increases with the height of signatures.Thus,a multi-stage framework was developed by developing consistency rules that restrict the number of higher-order signatures.Finally,phase stability analysis was conducted to evaluate the stability of the solvent-oil blend.As a result,optimal solvents that improve the solvent-oil blend properties while displaying low environmental impact were identified.
基金the Ministry of Science and Innovation (Spain)through the project PID2020-115566RB-I00.A.C.-G.,A.M.A.-E.A.N.extend their sincere appreciation to the Distinguished Scientist Fellowship Program (DSFP)at King Saud University for funding of this work+4 种基金support from the Spanish Ministry of Economy,Industry,and Competitiveness (MINECO)through a Juan de la Cierva-formación fellowship 2017 FJCI-2017-32919.J.Q.support from the Agencia Estatal de Investigación of Spain (Grants PID2019-106820RB,RTI2018-097180-B-100,and PGC2018-097018-BI00)the Junta de Castilla y León (Grants SA256P18 and SA121P20),including funding by ERDF/FEDER.J.Q.support from Universidad Complutense de Madrid and European Commision (MSCA COFUND UNA4CAREER grant.Project number 4129252)from MICINN (Spain)through the program Juan de la Cierva-Incorporación.
文摘We present a low-cost and easy-to-implement technique to fabricate large-area WS_(2) photodetector devices onto transparent and flexible polycarbonate substrates.The method relies on the deposition of large-area(in the cm scale)thin films(~30 nm thick)of WS_(2) by a recently introduced abrasion-induced method.Interdigitated electrical contacts are then deposited by thermal evaporation through a shadow mask.The photodetectors present well-balanced performances with an good trade-off between responsivity(up to 144 mA/W at a source-drain voltage of 10 V and illumination power of 1μW)and response time(down to~70µs)and a detectivity value of 10^(8) Jones.We found that the devices perform very reversibly upon several illumination and straining cycles and we found a moderate device-to-device variation.
基金the University Grants Commission(UGC)of the Government of India(Minor research grant:47-584/13(WRO)).
文摘Emerging contaminants like metal nanoparticles get introduced into soil through different routes.Toxic effects of these contaminants on plant growth-promoting bacteria(PGPB),which influence plant productivity,can be detrimental to soil health.Titanium dioxide is one of the most produced nanomaterials in the world and therefore potentially the most released nanoform in soil.The objective of this study was to evaluate the toxic effects of titanium dioxide nanoparticles(TiO2 NPs)on plant growth-promoting bacteria.Three types of PGPB,viz.,nitrogen fixers,phosphate solubilizers and biofilm formers were exposed to TiO2 NPs.Our results suggest that direct contact of the bacteria with these NPs is inhibitory as compared to when these bacteria are growing in laboratory nutrient media in the presence of NPs.The inhibitory effect did not follow a linear dose response but instead showed a pronounced step response.Soils with their varying characteristics may not afford the same protection to bacteria as laboratory nutrient media and thus TiO2 NPs may cause some sensitive PGPB to disappear from soil.The resultant shift in bacterial community composition may affect ecosystem functioning.
文摘In simulations of fluidized beds using computational fluid dynamics （CFD）, the description of gas-solid flow hydrodynamics relies on a drag model to account for the momentum transfer between gas and solid phases. Although several studies of drag models have been published, there have been few investigations of the application of lattice Boltzmann method （LBM）-based drag models to bubbling fluidized bed simu- lations. In the present study, a comprehensive comparison of empirical and LBM-based drag models was carried out to assess the performance of these models during simulations of gas-solid flow hydrodynam- ics in a bubbling fluidized bed. A CFD model using the MFIX code based on the Eulerian-Eulerian approach and the kinetic theory of granular flow was used to simulate a 2D bubbling fluidized bed with Geldart B particles. The simulation results were validated by comparison with experimental data. Statistical anal- ysis of the results shows that LBM-based drag models can reliably model gas-solid flow hydrodynamics in a bubbling fluidized bed.
基金This work was funded by the Swiss Nanoscience Institute in Basel,Switzerland(SNI PhD graduate school,Project P1202).
文摘Trapping and manipulation of nano-objects in solution are of great interest and have emerged in a plethora of fields spanning from soft condensed matter to biophysics and medical diagnostics.We report on establishing a nanofluidic system for reliable and contact-free trapping as well as manipulation of charged nano-objects using elastic polydimethylsiloxane(PDMS)-based materials.This trapping principle is based on electrostatic repulsion between charged nanofluidic walls and confined charged objects,called geometry-induced electrostatic(GIE)trapping.With gold nanoparticles as probes,we study the performance of the devices by measuring the stiffness and potential depths of the implemented traps,and compare the results with numerical simulations.When trapping 100 nm particles,we observe potential depths of up to Q≅24 k_(B)T that provide stable trapping for many days.Taking advantage of the soft material properties of PDMS,we actively tune the trapping strength and potential depth by elastically reducing the device channel height,which boosts the potential depth up to Q~200 k_(B)T,providing practically permanent contactfree trapping.Due to a high-throughput and low-cost fabrication process,ease of use,and excellent trapping performance,our method provides a reliable platform for research and applications in study and manipulation of single nano-objects in fluids.
基金the UJ Global Excellence and Stature(GES)for Postdoctoral Fellowship Award offered him as well as the University of Ilorin,Ilorin,Nigeria,for the one-year study leave granted the main author.The co-author(Prof J.C.Ngila)also thanks UJ Global Excellence and Stature Scholarship for the running cost paid by Water Research Commission(WRC)Project No.K5/2365.
文摘The contamination of the environment by organic pollutants is a major risk factor,particularly for developing countries.Selected organic pollutants(SOPs)like the phenolic compounds,polyaromatic hydrocarbons(PAHs),pesticides,and herbicides pose serious environmental and health issues owing to their toxic characteristics and poor degradability.Apart from their potential mutagenicity,carcinogenicity,tetragenicity and high body accumulation,these pollutants have become an increase concern worldwide.Biosorption is a promising alternative strategy for removing organic pollutants during water purification processes.Biosorbents have several advantages such as simplicity of operation,good sorption capacity,high recoverability and modifiability.As a result,the focus and novelty of this review is on recent trends in the use of biosorbents,with a particular emphasis on the removal of SOPs from wastewater.It also cover use of bacteria biosorbents,fungal,algae and chitosan/chitin biosorbents.Apart from that,we have also reviewed various classes of SOPs,their levels in the environment,classification and available characteristics techniques suitable for the adsorption experiments of these nanocomposites materials.In addition,we have provided comprehensive explanations and conclusions on possible future application of biosorbents and the mechanism of adsorption of these materials for removal of these SOPs from wastewater during water purification processes.
文摘In recent years,a lot of research has been done on silver nanoparticles(SNP)due to their numerous applications in the biomedical,pharmaceutical,and drug delivery industries.In this present study SNP were green synthesized using Melicope lunu-ankenda(M.lunu-ankenda)leaf extract.The addition of AgNO3 causes a color change.L-arginine addition results in further colour changes confirming conjugation.A UV–Vis spectrophotometric examination showed that the absorption peak for SNP was 435 nm,while the peak for L-arginine SNP(cSNP)was 422 nm.FTIR analysis confirmed the association of amides and amines with nanoparticles.The spherical nature of the silver was disclosed by SEM,and its elemental character is verified by EDS.The thermal stability of the nanoparticles is determined by TGA analysis,while TEM examination verifies their spherical shape.Using the MTT assay,these cSNP exhibited outstanding toxicity analysis(IC5038.72μg/ml)against MDA-MB-231 cells.These cSNP causes damage to the mitochondria(JC1 staining),which causes oxidative stress and the production of ROS with 83%of DCF expression in cancer cells.Furthermore,as demonstrated by the Comet assay and DAPI,these cSNP cause good DNA damage in the treated cells.Additionally,using flow cytometry,cSNPs potentially trigger apoptosis by triggering the expression of caspase 3 and caspase 8 proteins.Additionally,through CAM,cSNP demonstrated strong anti-angiogenesis activity by reducing the number of blood vessel branches.These findings suggest that cSNP may be crucial for drug delivery and cancer treatment.
基金supported by the Natural Science Foundation of Guangdong Province,China(2023A1515030162,2022A1515010333)the Guangdong Basic and Applied Basic Research Foundation(2022A1515140122)+1 种基金the National Natural Science Foundation of China(42377245)Guangdong Foundation for Program of Science and Technology Research,China(2023B1212060044).
文摘Boron-doped biochar(B-BC)was synthesized by pyrolysis using solid waste of sorghum straw as raw material.The specific surface area of B-BC increased significantly by 2.38 times compared to that of pure BC.This enhancement allowed B-BC(0.3 g L^(−1))to achieve complete adsorption of 10 mg L^(−1)tartrazine(TTZ)within 40 min.Moreover,acidic conditions were more favorable for TTZ adsorption,achieving complete removal of TTZ in only 15 min at a pH of 3.0.Interestingly,the adsorption rate of TTZ by B-BC in the presence of 0.05 M Cl^(-)was approximately 2.12 times higher than that in the absence of Cl^(-).When other background electrolytes were present,excluding PO_(4)^(3−),complete adsorption of TTZ could also be achieved within 60 min.Thermodynamic analysis and DFT calculations described the parameters of B-BC for TTZ adsorption,includingG(<0 kJ mol^(−1)),H(−2.199 kJ mol^(−1)),S(−6.068 J mol^(−1)K^(−1)),and the adsorption energy(E_(ads)=−0.6919 eV),indicating a tendency towards a spontaneous adsorption process.Moreover,the strong electron transfer ability of B-BC and the oxygen-containing groups promoted the activation of PDS and generation of active substances such as^(1)O_(2),O_(2)^(•−),and SO_(4)^(•−),thereby degrading TTZ into products with lower biological toxicity.When the added PDS was only 0.1 mM,the degradation rate constant of TTZ could reach 0.1481 min−1.Furthermore,boron doping enhanced the stability of biochar,enabling the complete removal of 10 mg L^(−1)TTZ even after recycling and regeneration.In summary,this study offers a practical solution for the resource utilization of solid waste sorghum straw and the treatment of TTZ-polluted wastewater.
