Particle transport phenomena in small-scale circulating fiuidized beds (CFB) can be simulated using the Euler-Euler, discrete element method, and Euler-Lagrange approaches. In this work, a hybrid Euler-Lagrange mode...Particle transport phenomena in small-scale circulating fiuidized beds (CFB) can be simulated using the Euler-Euler, discrete element method, and Euler-Lagrange approaches. In this work, a hybrid Euler-Lagrange model known as the dense discrete phase model (DDPM), which has common roots with the multiphase particle-in-cell model, was applied in simulating particle transport within a mid-sized experimental CFB facility. Implementation of the DDPM into the commercial ANSYS Fluent CFD package is relatively young in comparison with the granular Eulerian model. For that reason, validation of the DDPM approach against experimental data is still required and is addressed in this paper. Additional difficulties encountered in modeling fluidization processes are connected with long calculation times. To reduce times, the complete boiler models are simplified to include just the combustion chamber. Such simplifications introduce errors in the predicted solid distribution in the boiler. To investigate the conse- quences of model reduction, simulations were made using the simplified and complete pilot geometries and compared with experimental data. All simulations were performed using the ANSYSFLUENT 14.0 package. A set of user defined functions were used in the hybrid DDPM and Euler-Euler approaches to recirculate solid particles.展开更多
This paper presents a numerical simulation of the flow inside a cyclone separator at high particle loads. The gas and gas–particle flows were analyzed using a commercial computational fluid dynamics code. The turbule...This paper presents a numerical simulation of the flow inside a cyclone separator at high particle loads. The gas and gas–particle flows were analyzed using a commercial computational fluid dynamics code. The turbulence effects inside the separator were modeled using the Reynolds stress model. The two phase gas–solid particles flow was modeled using a hybrid Euler–Lagrange approach, which accounts for the four-way coupling between phases. The simulations were performed for three inlet velocities of the gaseous phase and several cyclone mass particle loadings. Moreover, the influences of several submodel parameters on the calculated results were investigated. The obtained results were compared against experimental data collected at the in-house experimental rig. The cyclone pressure drop evaluated numerically underpredicts the measured values. The possible reason of this discrepancies was disused.展开更多
Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruct...Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruction of the damaged bones,tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants.Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration.Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications.Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity,biocompatibility,biodegradability,availability through renewable resources,and the low cost of preparation and processing.Furthermore,cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair.This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration,including cellulose-organic composites,cellulose-inorganic composites,cellulose-organic/inorganic composites.We will also highlight the physicochemical,mechanical,and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.展开更多
Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered devices.To improve the working performance of energy harvesters effectively,a suitable structura...Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered devices.To improve the working performance of energy harvesters effectively,a suitable structural design is crucial.This paper proposes a dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system to enhance the functional performance of aeroelastic energy harvesters in environments with variable wind speeds.The system contains two piezoelectric beams coupled by magnets(forming upstream and downstream energy harvesters),and each beam is attached with a foam cylinder.A corresponding dynamic model is provided,and output characteristics are obtained at different wind speeds.Results and experimental verification indicate that both upstream and downstream energy harvesters can realize efficient energy harvesting.When the wind speed exceeds a certain critical value,the amplitudes of the system’s displacement and voltage are high.The wind speed threshold value is approximately 1.25 m/s.When the wind speed and magnet spacing are 10.2 m/s and 20 mm,respectively,the output power of the system reaches 4.9×10^(−4)W.Moreover,the wind speed threshold value of the proposed system can be adjusted by an equivalent nonlinear restoring force.展开更多
The robotic airship can provide a promising aerostatic platform for many potential applications.These applications require a precise autonomous trajectory tracking control for airship.Airship has a nonlinear and uncer...The robotic airship can provide a promising aerostatic platform for many potential applications.These applications require a precise autonomous trajectory tracking control for airship.Airship has a nonlinear and uncertain dynamics.It is prone to wind disturbances that offer a challenge for a trajectory tracking control design.This paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed parameters.It uses extended Kalman filter(EKF)for uncertainty and disturbance estimation.The estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory tracking.This comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship trajectory.The proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model inaccuracies.The stability and convergence of the proposed method are investigated using the Lyapunov stability analysis.The simulation results show that the proposed method efficiently tracks the desired trajectory.The method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.展开更多
Background Medication adherence is an integral part of the comprehensive care of patients with atrial fibrillation (AF) receiving oral anticoagulations (OACs) therapy. Many patients with AF are elderly and may suf...Background Medication adherence is an integral part of the comprehensive care of patients with atrial fibrillation (AF) receiving oral anticoagulations (OACs) therapy. Many patients with AF are elderly and may suffer from some form of cognitive impairment. This study was conducted to investigate whether cognitive impairment affects the level of adherence to anticoagulation treatment in AF patients. Me- thods The study involved 111 AF patients (mean age, 73.5±8.3 years) treated with OACs. Cognitive function was assessed using the Mini Mental State Examination (MMSE). The level of adherence was assessed by the 8-item Mot^sky Medication Adherence Scale (MMAS-8). Scores on the MMAS-8 range from 0 to 8, with scores 〈 6 reflecting low adherence, 6 to 〈 8 medium adherence, and 8 high adherence. Re- sults 46.9% of AF patients had low adherence, 18.8% had moderate adherence, and 33.3% had high adherence to OACs. Patients with lower adherence were older than those with moderate or high adherence (76.6 ±8.7 vs. 71.3 ~ 6.4 vs. 71.1 ± 6.7 years) and obtained low MMSE scores, indicating cognitive disorders or dementia (MMSE = 22.3 ± 4.2). Patients with moderate or high adherence obtained high MMSE test results (27.5 ±1.7 and 27,5 ± 3.6). According to Spearman's rank correlation, worse adherence to treatment with OACs was determined by older age (rs = -0.372) and lower MMSE scores (rs = 0.717). According to multivariate regression analysis, the level of cognitive function was a significant independent predictor of adherence (b = 1.139). Conclusions Cognitive impairment is an independent determinant of compliance with pharmacological therapy in elderly patients with AF. Lower adherence, beyond the assessment of cognitive function, is related to the age of patients.展开更多
This study describes the corrosion resistance of extruded,and extruded with post-processing annealing,Mg–7.5 Li–3 Al–1 Zn alloys.The results demonstrate that extrusion at 350°C with an extrusion speed 0.5 s^(-...This study describes the corrosion resistance of extruded,and extruded with post-processing annealing,Mg–7.5 Li–3 Al–1 Zn alloys.The results demonstrate that extrusion at 350°C with an extrusion speed 0.5 s^(-1) does not lead to the full recrystallization of the alloy,and the material still exhibits a dendritic microstructure.The post-processing annealing triggers the microstructure transformation,and the relative composition of the alloy changes.The ratio ofβ(Li)toα(Mg)in the extruded alloy was 29–71%;after annealing amount ofβ(Li)increased,and the ratio ofβ(Li)toα(Mg)in the annealed alloy was 35–65%.Corrosion testing shows that in 3.5 wt%Na Cl the extruded alloys immediately undergo strong dissolution.As a result of the subsequent annealing,an improvement of corrosion resistance is observed.The higher amount ofβ(Li)in the annealed alloy reduces the area ratio of cathodic to anodic sites of corrosion,and this makes the annealed alloy more resistive under the analyzed conditions.展开更多
The constantly developing fiuidized combustion technology has become competitive with a conventional pulverized coal (PC) combustion. Circulating fluidized bed (CFB) boilers can be a good alternative to PC boilers...The constantly developing fiuidized combustion technology has become competitive with a conventional pulverized coal (PC) combustion. Circulating fluidized bed (CFB) boilers can be a good alternative to PC boilers due to their robustness and lower sensitivity to the fuel quality. However, appropriate engineering tools that can be used to model and optimize the construction and operating parameters of a CFB boiler still require development. This paper presents the application of a relatively novel hybrid Euler-Lagrange approach to model the dense gas-solid flow combined with a combustion process in a large-scale indus- trial CFB boiler. In this work, this complex flow has been resolved by applying the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) code. To accurately resolve the multiphase flow, the original CFD code has been extended by additional user-defined functions. These functions were used to control the boiler mass load, particle recirculation process (simplified boiler geometry), and interphase hydrodynamic properties. This work was split into two parts. In the first part, which is referred to as pseudo combustion, the combustion process was not directly simulated. Instead, the effect of the chemi- cal reactions was simulated by modifying the density of the continuous phase so that it corresponded to the mean temperature and composition of the flue gases, In this stage, the particle transport was simu- lated using the standard Euler-Euler and novel hybrid Euler-Lagrange approaches, The obtained results were compared against measured data, and both models were compared to each other. In the second part, the numerical model was enhanced by including the chemistry and physics of combustion. To the best of the authors' knowledge, the use of the hybrid Euler-Lagrange approach to model combustion is a new engineering application of this model, In this work, the combustion process was modeled for air-fuel combustion. The simulation results were compared with experimental data.展开更多
There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyuretha...There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyurethane(FPPU)elastomer based on octafluoro-4,4'-biphenol to overcome this challenge.This fluorine-based motif not only tunes interchain interactions throughπ-πstacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms.The developed FPPU elastomer shows the highest recorded puncture energy(648.0 m J),high tensile strength(27.0 MPa),as well as excellent selfhealing efficiency(92.3%),along with low surface energy(50.9 MJ m^(-2)),notch-insensitivity,and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane(BPPU)elastomer.Taking advantage of the above-mentioned merits of FPPU elastomer,we prepare an anti-fouling triboelectric nanogenerator(TENG)with a self-healable,and reprocessable elastic substrate.Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms,this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer.Furthermore,a healable and stretchable conductive composite is prepared.This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.展开更多
Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electric...Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.展开更多
Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts.Typically,in the case...Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts.Typically,in the case of sulfides,the catalytic activity is drastically hindered by the quick reassembly of excitons and the photocorrosion effect.Hence designing and generating S-vacancies in metal sulfides has emerged as a potential strategy for attaining adequate water splitting to generate H_(2) and O_(2) because of the simulta-neous improvement in the optoelectronic features.However,developing efficient catalysts that manifest optimal photo(electro)catalytic performance for large-scale applicability remains challenging.Therefore,it is of utmost interest to explore the insightful features of creating S-vacancy and study their impact on catalytic performance.This review article aims to comprehensively highlight the roles of S-vacancy in sulfides for amended overall water-splitting activity.The photocatalytic features of S-vacancies modulated metal sulfides are deliberated,followed by various advanced synthetic and characterization techniques for effectual generation and identification of vacancy defects.The specific aspects of S-vacancies in refin-ing the optical absorption range charge carrier dynamics,and photoinduced surface chemical reactions are critically examined for overall water splitting applications.Finally,the vouchsafing outlooks and op-portunities confronting the defect-engineered(S-vacancy)metal sulfides-based photocatalysts have been summarized.展开更多
Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal.The desulphurization control system,however,is subjected to complex reaction mechanis...Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal.The desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system robustness.To address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this paper.The UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant dynamics.By viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear one.The obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled dynamics.In the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and robustness.Furthermore,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.展开更多
The present work aims to assess earthquake-induced earth-retaining(ER)wall displacement.This study is on the dynamics analysis of various earth-retaining wall designs in hollow precast concrete panels,reinforcement co...The present work aims to assess earthquake-induced earth-retaining(ER)wall displacement.This study is on the dynamics analysis of various earth-retaining wall designs in hollow precast concrete panels,reinforcement concrete facing panels,and gravity-type earth-retaining walls.The finite element(FE)simulations utilized a 3D plane strain condition to model full-scale ER walls and numerous nonlinear dynamics analyses.The seismic performance of differentmodels,which includes reinforcement concrete panels and gravity-type and hollowprecast concrete ER walls,was simulated and examined using the FE approach.It also displays comparative studies such as stress distribution,deflection of the wall,acceleration across the wall height,lateral wall displacement,lateral wall pressure,and backfill plastic strain.Three components of the created ER walls were found throughout this research procedure.One is a granular reinforcement backfill,while the other is a wall-facing panel and base foundation.The dynamic response effects of varied earth-retaining walls have also been studied.It was discovered that the facing panel of the model significantly impacts the earthquake-induced displacement of ER walls.The proposed analytical model’s validity has been evaluated and compared with the reinforcement concrete facing panels,gravity-type ER wall,scientifically available data,and American Association of State Highway and Transportation Officials(AASHTO)guidelines results based on FE simulation.The results of the observations indicate that the hollow prefabricated concrete ER wall is the most feasible option due to its lower displacement and high-stress distribution compared to the two types.The methodology and results of this study establish standards for future analogous investigations and professionals,particularly in light of the increasing computational capabilities of desktop computers.展开更多
In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in thi...In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in this ionic liquids class.The chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy,1D,and 2D-NMR analyses.The thermal behavior assessment was conducted through DSC and TGA experiments.DSC analysis revealed an endothermic glass transition at T_(g)=-61℃,followed by an exothermic degradation event at T_(onset)=311℃.Similarly,TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the sample.Furthermore,the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS,it-KAS,and VYA/CE isoconversional kinetic approaches.Consequently,the Arrhenius parameters(E_(a)=154 kJ·mol^(-1),Log(A/s^(-1))=11.8) and the most probable reaction model g(a) were determined.The observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified EIL.These findings revealed that[BBIm][N_(3)]EIL can be a promising candidate for advanced energetic material application.展开更多
Low mass ratio contact binary systems are more likely to have unstable orbits and potentially merge.In addition,such systems exhibit characteristics such as starspots and high energy emissions(UV)suggestive of chromos...Low mass ratio contact binary systems are more likely to have unstable orbits and potentially merge.In addition,such systems exhibit characteristics such as starspots and high energy emissions(UV)suggestive of chromospheric and magnetic activity.Light curve modeling of ten contact binary systems is reported.All were found to be of extreme low mass ratio ranging from 0.122 to 0.24 and three were found to be potentially unstable and possible merger candidates.Filling of the infrared calcium absorption lines is a marker of increased chromospheric activity.We use the available Large Sky Area Multi-Object Fiber Spectroscopic Telescope spectra along with matched standard spectra(broadened for rotation)to measure the excess filling of the central core depression flux of the two main infrared calcium absorption linesλ8542 andλ8662.We find that all reported contact binaries have excess filling of the core flux in the infrared calcium lines.Three of the systems reported were also observed by the Galaxy Evolution Explorer mission and we find that all three have features of excess ultraviolet emissions further adding evidence for increased chromospheric activity in low mass ratio contact binaries.Analysis of both orbital stability and absorption line filling is dependent on the determination of geometric and absolute parameters from light curve modeling.Not an insignificant number of contact binary light curves exhibit the O’Connell effect,usually attributed to starspots.We discuss the inclusion of starspots in light curve solutions and how they influence the geometric and absolute parameters.展开更多
In this study,S-scheme-based hydrothermal synthesis of Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)layered composites has been successfully reported.The photo-degradation of toxic dyes,viz.methyl orange(MO),and methylene blue(MB...In this study,S-scheme-based hydrothermal synthesis of Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)layered composites has been successfully reported.The photo-degradation of toxic dyes,viz.methyl orange(MO),and methylene blue(MB),has been used to examine nanocomposites with varying weight percent of Bi_(2)S_(3)for photocat-alytic activity in the visible range.Among candidates,Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)with a 10%loading of Bi_(2)S_(3)outperformed both pure and hybrid composites in photocatalytic activity.For MO degradation,the hybrid composite with 10%Bi_(2)S_(3)loading degrades 7.04 times higher than pristine CuBi_(2)O_(4)and Bi_(2)S_(3)samples,and for MB degradation,it degrades 4.96 times higher than pristine samples.High surface area,less re-combination rate of photogenerated charge carriers,photogenerated carriers faster separation,and high redox ability of Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)(10%)are all attributed to the improving photocatalytic perfor-mance.Even after ten cycles,the hybrid composite is chemically stable and reusable.Carbon nanotubes(CNTs)are a transfer bridge in layered structure for electrons because of their coordinated Fermi level between Ag-CuBi_(2)O_(4)and Bi_(2)S_(3).In addition,the scavenger and electron spin resonance(ESR)experiments verified that·O_(2)^(−),·OH,and h+were the important reactive species that successfully facilitated the pho-tocatalytic degradation process to degrade dyes.This study presents a straightforward and economical approach for obtaining a stable semiconductor-based photocatalytic system and a potential technique for future applications.展开更多
AIM: To evaluate the impact of chemoradiation admi- nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter- preserving total mesorectal excision (TME) for locally advan...AIM: To evaluate the impact of chemoradiation admi- nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter- preserving total mesorectal excision (TME) for locally advanced rectal cancer and to assess the association between chemoradiation and intra- and postoperative variables. METHODS: Twenty-one females were treated for locally advanced but preoperatively assessed as primarily resectable rectal cancer involving reproductive organs. Anterior resection with TME and excision of internal genitalia was combined with neo- or adjuvant chemoradiation. Two-year disease-free survival analysis was performed with the Kaplan-Meier method and log- rank test. The association between chemoradiation and other variables was evaluated with the Fisher’s exact test and Mann-Whitney test. RESULTS: Survival rate decreased in anaemic females (51.5% vs 57.4%), in patients older than 60 years (41.8% vs 66.7%) with poorly differentiated cancers (50.0% vs 55.6%) and tumors located ≤ 7 cm from the anal verge (42.9% vs 68.1%) but with the lack of importance. Patients with negative lymph nodes and women chemoradiated preoperatively had significantly favourable prognosis (85.7% vs 35.7%; P= 0.03 and 80.0% vs 27.3%; P = 0.01, respectively). Preoperative chemoradiation compared to adjuvant radiochemotherapy was not significantly associated with the duration of surgery, incidence of intraoperative bowel perforation and blood loss ≥ 1 L, rate of postoperative bladder and anorectal dysfunction, and minimal distal resection margin. It significantly influenced minimal radial margin (mean 4.2 mm vs 1.1 mm; P < 0.01). CONCLUSION: Despite involving internal genitalia, long-term disease-free survival and sphincter preservation may be achieved with combined-modality therapy for females with T4 locally advanced rectal carcinoma. Neoadjuvant chemoradiation does not compromise functional results and may significantly improve oncological outcomes probably due to enhanced radial clearance.展开更多
A laboratory-scale reaction-crystallization process of struvite synthesis from diluted water solution of Mg^2+, NH^+ 4 and PO3- ions was studied. The research covered the tests of two original constructions of conti...A laboratory-scale reaction-crystallization process of struvite synthesis from diluted water solution of Mg^2+, NH^+ 4 and PO3- ions was studied. The research covered the tests of two original constructions of continuous jet-pump Draft Tube Magma (DTM)-type crystallizers with internal circulation of suspension (upward/downward). Interactions between constructional, hydrodynamic and kinetic factors were established and discussed. Nucleation and linear growth rates of struvite crystals were calculated on the basis of population density distribution. Kinetic model of idealized Mixed Suspension Mixed Product Removal (MSMPR) crystallizer considering the size-dependent growth mechanism was applied (Rojkowski hyperbolic equation). For comparison purposes the kinetic data corre- sponded to a simpler, continuous draft tube-type crystallizer equipped with propeller agitator were analyzed. It was concluded that crystal product of larger size was withdrawn from the jet-pump DTM crystallizer of the descending flow of suspension in a mixing chamber.展开更多
Fabrication of functional scaffolds for tissue engineering and regenerative medicine applications requires material systems with precise control over cellular performance.3D printing is a powerful technique to create ...Fabrication of functional scaffolds for tissue engineering and regenerative medicine applications requires material systems with precise control over cellular performance.3D printing is a powerful technique to create highly complex and multicomponent structures with well-defined architecture and composition.In this review paper,we explore extrusion-based 3D printing methods(EBP,i.e.,Near Field Electrospinning(NFES),Melt Electrowriting(MEW),Fused Deposition Modeling(FDM),and extrusion bioprinting)in terms of their ability to produce scaffolds with bio-instructive properties.These material systems provide spatio-temporal guidance for cells,allowing controlled tissue regeneration and maturation.Multiple physical and biochemical cues introduced to the EBP scaffolds are evaluated in their ability to direct cell alignment,proliferation,differentiation,specific ECM production,and tissue maturation.We indicate that the cues have different impacts depending on the material system,cell type used,or coexistence of multiple cues.Therefore,they must be carefully chosen based on the targeted application.We propose future directions in bio-instructive materials development,including such concepts as metamaterials,hybrid living materials,and 4D printing.The review gathers the knowledge essential for designing new materials with a controlled cellular response,fabrication of advanced engineered tissue,and developing a better understanding of cell biology,especially in response to the biomaterial.展开更多
基金supported by the Statutory R&D Project ICh PW ( No.11.14.024 and 11.15.024 )a statutory activity subsidy from the Polish Ministry of ScienceHigher Education for the Faculty of Chemistry of Wroclaw University of Technology
基金supported by the National Center for Research and Development,within the confines of Research and Development Strategic Program Advanced Technologies for Energy Generation Project No.2 Oxy-combustion technology for PC and FBC boilers with CO_2 capture,Agreement No.SP/E/2/66420/10supported by the National Center for Research and Development as a research project development of coal gasification technology for high production of fuels and energy,CzTB 5.2
文摘Particle transport phenomena in small-scale circulating fiuidized beds (CFB) can be simulated using the Euler-Euler, discrete element method, and Euler-Lagrange approaches. In this work, a hybrid Euler-Lagrange model known as the dense discrete phase model (DDPM), which has common roots with the multiphase particle-in-cell model, was applied in simulating particle transport within a mid-sized experimental CFB facility. Implementation of the DDPM into the commercial ANSYS Fluent CFD package is relatively young in comparison with the granular Eulerian model. For that reason, validation of the DDPM approach against experimental data is still required and is addressed in this paper. Additional difficulties encountered in modeling fluidization processes are connected with long calculation times. To reduce times, the complete boiler models are simplified to include just the combustion chamber. Such simplifications introduce errors in the predicted solid distribution in the boiler. To investigate the conse- quences of model reduction, simulations were made using the simplified and complete pilot geometries and compared with experimental data. All simulations were performed using the ANSYSFLUENT 14.0 package. A set of user defined functions were used in the hybrid DDPM and Euler-Euler approaches to recirculate solid particles.
文摘This paper presents a numerical simulation of the flow inside a cyclone separator at high particle loads. The gas and gas–particle flows were analyzed using a commercial computational fluid dynamics code. The turbulence effects inside the separator were modeled using the Reynolds stress model. The two phase gas–solid particles flow was modeled using a hybrid Euler–Lagrange approach, which accounts for the four-way coupling between phases. The simulations were performed for three inlet velocities of the gaseous phase and several cyclone mass particle loadings. Moreover, the influences of several submodel parameters on the calculated results were investigated. The obtained results were compared against experimental data collected at the in-house experimental rig. The cyclone pressure drop evaluated numerically underpredicts the measured values. The possible reason of this discrepancies was disused.
文摘Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruction of the damaged bones,tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants.Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration.Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications.Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity,biocompatibility,biodegradability,availability through renewable resources,and the low cost of preparation and processing.Furthermore,cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair.This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration,including cellulose-organic composites,cellulose-inorganic composites,cellulose-organic/inorganic composites.We will also highlight the physicochemical,mechanical,and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.
基金supported by the National Natural Science Foundation of China(Grant No.52161135106)the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.JCYJ201908061536-15091)+4 种基金the International Science and Technology Cooperation Project of Guangdong Province(Grant No.2021A0505030012)the Innovation Capability Support Plan of Shaanxi Province(Grant No.2020KJXX-021)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(Grant No.CX2022001)the 111 Project(Grant No.BP0719007)supported by the National Science Centre,Poland under the project SHENG-2(Grant No.2021/40/Q/ST8/00362)。
文摘Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered devices.To improve the working performance of energy harvesters effectively,a suitable structural design is crucial.This paper proposes a dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system to enhance the functional performance of aeroelastic energy harvesters in environments with variable wind speeds.The system contains two piezoelectric beams coupled by magnets(forming upstream and downstream energy harvesters),and each beam is attached with a foam cylinder.A corresponding dynamic model is provided,and output characteristics are obtained at different wind speeds.Results and experimental verification indicate that both upstream and downstream energy harvesters can realize efficient energy harvesting.When the wind speed exceeds a certain critical value,the amplitudes of the system’s displacement and voltage are high.The wind speed threshold value is approximately 1.25 m/s.When the wind speed and magnet spacing are 10.2 m/s and 20 mm,respectively,the output power of the system reaches 4.9×10^(−4)W.Moreover,the wind speed threshold value of the proposed system can be adjusted by an equivalent nonlinear restoring force.
文摘The robotic airship can provide a promising aerostatic platform for many potential applications.These applications require a precise autonomous trajectory tracking control for airship.Airship has a nonlinear and uncertain dynamics.It is prone to wind disturbances that offer a challenge for a trajectory tracking control design.This paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed parameters.It uses extended Kalman filter(EKF)for uncertainty and disturbance estimation.The estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory tracking.This comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship trajectory.The proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model inaccuracies.The stability and convergence of the proposed method are investigated using the Lyapunov stability analysis.The simulation results show that the proposed method efficiently tracks the desired trajectory.The method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.
文摘Background Medication adherence is an integral part of the comprehensive care of patients with atrial fibrillation (AF) receiving oral anticoagulations (OACs) therapy. Many patients with AF are elderly and may suffer from some form of cognitive impairment. This study was conducted to investigate whether cognitive impairment affects the level of adherence to anticoagulation treatment in AF patients. Me- thods The study involved 111 AF patients (mean age, 73.5±8.3 years) treated with OACs. Cognitive function was assessed using the Mini Mental State Examination (MMSE). The level of adherence was assessed by the 8-item Mot^sky Medication Adherence Scale (MMAS-8). Scores on the MMAS-8 range from 0 to 8, with scores 〈 6 reflecting low adherence, 6 to 〈 8 medium adherence, and 8 high adherence. Re- sults 46.9% of AF patients had low adherence, 18.8% had moderate adherence, and 33.3% had high adherence to OACs. Patients with lower adherence were older than those with moderate or high adherence (76.6 ±8.7 vs. 71.3 ~ 6.4 vs. 71.1 ± 6.7 years) and obtained low MMSE scores, indicating cognitive disorders or dementia (MMSE = 22.3 ± 4.2). Patients with moderate or high adherence obtained high MMSE test results (27.5 ±1.7 and 27,5 ± 3.6). According to Spearman's rank correlation, worse adherence to treatment with OACs was determined by older age (rs = -0.372) and lower MMSE scores (rs = 0.717). According to multivariate regression analysis, the level of cognitive function was a significant independent predictor of adherence (b = 1.139). Conclusions Cognitive impairment is an independent determinant of compliance with pharmacological therapy in elderly patients with AF. Lower adherence, beyond the assessment of cognitive function, is related to the age of patients.
文摘This study describes the corrosion resistance of extruded,and extruded with post-processing annealing,Mg–7.5 Li–3 Al–1 Zn alloys.The results demonstrate that extrusion at 350°C with an extrusion speed 0.5 s^(-1) does not lead to the full recrystallization of the alloy,and the material still exhibits a dendritic microstructure.The post-processing annealing triggers the microstructure transformation,and the relative composition of the alloy changes.The ratio ofβ(Li)toα(Mg)in the extruded alloy was 29–71%;after annealing amount ofβ(Li)increased,and the ratio ofβ(Li)toα(Mg)in the annealed alloy was 35–65%.Corrosion testing shows that in 3.5 wt%Na Cl the extruded alloys immediately undergo strong dissolution.As a result of the subsequent annealing,an improvement of corrosion resistance is observed.The higher amount ofβ(Li)in the annealed alloy reduces the area ratio of cathodic to anodic sites of corrosion,and this makes the annealed alloy more resistive under the analyzed conditions.
基金supported by the National Center for Research and Development within the confines of Research and Development Strategic Program Advanced Technologies for Energy Generation project No.2 Oxy-combustion technology for PC andFBC boilers with CO_2 capture Agreement No.SP/E/2/66420/10supported by the National Center for Research and Development as a research project Development of coal gasification technology for high production of fuels and energy,CzTB 5.2
文摘The constantly developing fiuidized combustion technology has become competitive with a conventional pulverized coal (PC) combustion. Circulating fluidized bed (CFB) boilers can be a good alternative to PC boilers due to their robustness and lower sensitivity to the fuel quality. However, appropriate engineering tools that can be used to model and optimize the construction and operating parameters of a CFB boiler still require development. This paper presents the application of a relatively novel hybrid Euler-Lagrange approach to model the dense gas-solid flow combined with a combustion process in a large-scale indus- trial CFB boiler. In this work, this complex flow has been resolved by applying the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) code. To accurately resolve the multiphase flow, the original CFD code has been extended by additional user-defined functions. These functions were used to control the boiler mass load, particle recirculation process (simplified boiler geometry), and interphase hydrodynamic properties. This work was split into two parts. In the first part, which is referred to as pseudo combustion, the combustion process was not directly simulated. Instead, the effect of the chemi- cal reactions was simulated by modifying the density of the continuous phase so that it corresponded to the mean temperature and composition of the flue gases, In this stage, the particle transport was simu- lated using the standard Euler-Euler and novel hybrid Euler-Lagrange approaches, The obtained results were compared against measured data, and both models were compared to each other. In the second part, the numerical model was enhanced by including the chemistry and physics of combustion. To the best of the authors' knowledge, the use of the hybrid Euler-Lagrange approach to model combustion is a new engineering application of this model, In this work, the combustion process was modeled for air-fuel combustion. The simulation results were compared with experimental data.
基金supported by the National Natural Science Foundation of China(52173117,52073049,and 21991123)the National Key Research and Development Program of China(2021YFC2101800 and 2021YFC2400802)+3 种基金Ningbo 2025 Science and Technology Major Project(2019B10068)the Natural Science Foundation of Shanghai(22ZR1400700)Shanghai Rising-Star Program(21QA1400200)the Science and Technology Commission of Shanghai Municipality(20DZ2254900 and 20DZ2270800)。
文摘There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyurethane(FPPU)elastomer based on octafluoro-4,4'-biphenol to overcome this challenge.This fluorine-based motif not only tunes interchain interactions throughπ-πstacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms.The developed FPPU elastomer shows the highest recorded puncture energy(648.0 m J),high tensile strength(27.0 MPa),as well as excellent selfhealing efficiency(92.3%),along with low surface energy(50.9 MJ m^(-2)),notch-insensitivity,and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane(BPPU)elastomer.Taking advantage of the above-mentioned merits of FPPU elastomer,we prepare an anti-fouling triboelectric nanogenerator(TENG)with a self-healable,and reprocessable elastic substrate.Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms,this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer.Furthermore,a healable and stretchable conductive composite is prepared.This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.
基金supported by the National Key Research and Development Program of China(2021YFC2101800,2021YFC2400802)the National Natural Science Foundation of China(52173117,21991123)+1 种基金the Ningbo 2025 Science and Technology Major Project(2019B10068)the Science and Technology Commission of Shanghai(20DZ2254900,20DZ2270800)。
文摘Inspired by the multi-layer architecture of mammal skins,interfacial robust,stretchable,and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices,wearable electrical devices,and soft robotics.However,existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness,complex and time-consuming preparation process,unhealable,and non-reconfiguration.Herein,we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles.Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer(interfacial toughness:390 J m^(-2)),endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration.Moreover,this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration.Taking advantage of the aforementioned features,we readily constructed a multi-module,self-healing,self-powered,and realtime monitoring of personal status integrated elastic electronics,which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.
基金This research was supported by Brain Pool Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(No.2020H1D3A1A04081409。
文摘Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts.Typically,in the case of sulfides,the catalytic activity is drastically hindered by the quick reassembly of excitons and the photocorrosion effect.Hence designing and generating S-vacancies in metal sulfides has emerged as a potential strategy for attaining adequate water splitting to generate H_(2) and O_(2) because of the simulta-neous improvement in the optoelectronic features.However,developing efficient catalysts that manifest optimal photo(electro)catalytic performance for large-scale applicability remains challenging.Therefore,it is of utmost interest to explore the insightful features of creating S-vacancy and study their impact on catalytic performance.This review article aims to comprehensively highlight the roles of S-vacancy in sulfides for amended overall water-splitting activity.The photocatalytic features of S-vacancies modulated metal sulfides are deliberated,followed by various advanced synthetic and characterization techniques for effectual generation and identification of vacancy defects.The specific aspects of S-vacancies in refin-ing the optical absorption range charge carrier dynamics,and photoinduced surface chemical reactions are critically examined for overall water splitting applications.Finally,the vouchsafing outlooks and op-portunities confronting the defect-engineered(S-vacancy)metal sulfides-based photocatalysts have been summarized.
基金supported by the key project of the National Nature Science Foundation of China(51736002).
文摘Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal.The desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system robustness.To address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this paper.The UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant dynamics.By viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear one.The obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled dynamics.In the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and robustness.Furthermore,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.
基金supported by Supported by the Science and Technology Research Program of the Institute of Mountain Hazards and Environment,CAS(IMHE-ZDRW-01)the National Natural Science Foundation of China,China(Grant Numbers:42077275&42271086)the Special Project of Basic Research-Key Project,Yunnan(Grant Number:202301AS070039).
文摘The present work aims to assess earthquake-induced earth-retaining(ER)wall displacement.This study is on the dynamics analysis of various earth-retaining wall designs in hollow precast concrete panels,reinforcement concrete facing panels,and gravity-type earth-retaining walls.The finite element(FE)simulations utilized a 3D plane strain condition to model full-scale ER walls and numerous nonlinear dynamics analyses.The seismic performance of differentmodels,which includes reinforcement concrete panels and gravity-type and hollowprecast concrete ER walls,was simulated and examined using the FE approach.It also displays comparative studies such as stress distribution,deflection of the wall,acceleration across the wall height,lateral wall displacement,lateral wall pressure,and backfill plastic strain.Three components of the created ER walls were found throughout this research procedure.One is a granular reinforcement backfill,while the other is a wall-facing panel and base foundation.The dynamic response effects of varied earth-retaining walls have also been studied.It was discovered that the facing panel of the model significantly impacts the earthquake-induced displacement of ER walls.The proposed analytical model’s validity has been evaluated and compared with the reinforcement concrete facing panels,gravity-type ER wall,scientifically available data,and American Association of State Highway and Transportation Officials(AASHTO)guidelines results based on FE simulation.The results of the observations indicate that the hollow prefabricated concrete ER wall is the most feasible option due to its lower displacement and high-stress distribution compared to the two types.The methodology and results of this study establish standards for future analogous investigations and professionals,particularly in light of the increasing computational capabilities of desktop computers.
文摘In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in this ionic liquids class.The chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy,1D,and 2D-NMR analyses.The thermal behavior assessment was conducted through DSC and TGA experiments.DSC analysis revealed an endothermic glass transition at T_(g)=-61℃,followed by an exothermic degradation event at T_(onset)=311℃.Similarly,TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the sample.Furthermore,the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS,it-KAS,and VYA/CE isoconversional kinetic approaches.Consequently,the Arrhenius parameters(E_(a)=154 kJ·mol^(-1),Log(A/s^(-1))=11.8) and the most probable reaction model g(a) were determined.The observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified EIL.These findings revealed that[BBIm][N_(3)]EIL can be a promising candidate for advanced energetic material application.
基金support by the Astronomical station Vidojevica,funding from the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(contract No.451-03-66/2024-03/200002)by the EC through project BELISSIMA(call FP7-REGPOT-2010-5,No.265772)financed by Silesian University of Technology Statutory Activities grant No.BK-250/RAu-11/2024。
文摘Low mass ratio contact binary systems are more likely to have unstable orbits and potentially merge.In addition,such systems exhibit characteristics such as starspots and high energy emissions(UV)suggestive of chromospheric and magnetic activity.Light curve modeling of ten contact binary systems is reported.All were found to be of extreme low mass ratio ranging from 0.122 to 0.24 and three were found to be potentially unstable and possible merger candidates.Filling of the infrared calcium absorption lines is a marker of increased chromospheric activity.We use the available Large Sky Area Multi-Object Fiber Spectroscopic Telescope spectra along with matched standard spectra(broadened for rotation)to measure the excess filling of the central core depression flux of the two main infrared calcium absorption linesλ8542 andλ8662.We find that all reported contact binaries have excess filling of the core flux in the infrared calcium lines.Three of the systems reported were also observed by the Galaxy Evolution Explorer mission and we find that all three have features of excess ultraviolet emissions further adding evidence for increased chromospheric activity in low mass ratio contact binaries.Analysis of both orbital stability and absorption line filling is dependent on the determination of geometric and absolute parameters from light curve modeling.Not an insignificant number of contact binary light curves exhibit the O’Connell effect,usually attributed to starspots.We discuss the inclusion of starspots in light curve solutions and how they influence the geometric and absolute parameters.
基金the Researchers Supporting Project number(No.RSP2023R6),King Saud University,Riyadh,Saudi Arabia.
文摘In this study,S-scheme-based hydrothermal synthesis of Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)layered composites has been successfully reported.The photo-degradation of toxic dyes,viz.methyl orange(MO),and methylene blue(MB),has been used to examine nanocomposites with varying weight percent of Bi_(2)S_(3)for photocat-alytic activity in the visible range.Among candidates,Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)with a 10%loading of Bi_(2)S_(3)outperformed both pure and hybrid composites in photocatalytic activity.For MO degradation,the hybrid composite with 10%Bi_(2)S_(3)loading degrades 7.04 times higher than pristine CuBi_(2)O_(4)and Bi_(2)S_(3)samples,and for MB degradation,it degrades 4.96 times higher than pristine samples.High surface area,less re-combination rate of photogenerated charge carriers,photogenerated carriers faster separation,and high redox ability of Ag-CuBi_(2)O_(4)/CNTs/Bi_(2)S_(3)(10%)are all attributed to the improving photocatalytic perfor-mance.Even after ten cycles,the hybrid composite is chemically stable and reusable.Carbon nanotubes(CNTs)are a transfer bridge in layered structure for electrons because of their coordinated Fermi level between Ag-CuBi_(2)O_(4)and Bi_(2)S_(3).In addition,the scavenger and electron spin resonance(ESR)experiments verified that·O_(2)^(−),·OH,and h+were the important reactive species that successfully facilitated the pho-tocatalytic degradation process to degrade dyes.This study presents a straightforward and economical approach for obtaining a stable semiconductor-based photocatalytic system and a potential technique for future applications.
文摘AIM: To evaluate the impact of chemoradiation admi- nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter- preserving total mesorectal excision (TME) for locally advanced rectal cancer and to assess the association between chemoradiation and intra- and postoperative variables. METHODS: Twenty-one females were treated for locally advanced but preoperatively assessed as primarily resectable rectal cancer involving reproductive organs. Anterior resection with TME and excision of internal genitalia was combined with neo- or adjuvant chemoradiation. Two-year disease-free survival analysis was performed with the Kaplan-Meier method and log- rank test. The association between chemoradiation and other variables was evaluated with the Fisher’s exact test and Mann-Whitney test. RESULTS: Survival rate decreased in anaemic females (51.5% vs 57.4%), in patients older than 60 years (41.8% vs 66.7%) with poorly differentiated cancers (50.0% vs 55.6%) and tumors located ≤ 7 cm from the anal verge (42.9% vs 68.1%) but with the lack of importance. Patients with negative lymph nodes and women chemoradiated preoperatively had significantly favourable prognosis (85.7% vs 35.7%; P= 0.03 and 80.0% vs 27.3%; P = 0.01, respectively). Preoperative chemoradiation compared to adjuvant radiochemotherapy was not significantly associated with the duration of surgery, incidence of intraoperative bowel perforation and blood loss ≥ 1 L, rate of postoperative bladder and anorectal dysfunction, and minimal distal resection margin. It significantly influenced minimal radial margin (mean 4.2 mm vs 1.1 mm; P < 0.01). CONCLUSION: Despite involving internal genitalia, long-term disease-free survival and sphincter preservation may be achieved with combined-modality therapy for females with T4 locally advanced rectal carcinoma. Neoadjuvant chemoradiation does not compromise functional results and may significantly improve oncological outcomes probably due to enhanced radial clearance.
文摘A laboratory-scale reaction-crystallization process of struvite synthesis from diluted water solution of Mg^2+, NH^+ 4 and PO3- ions was studied. The research covered the tests of two original constructions of continuous jet-pump Draft Tube Magma (DTM)-type crystallizers with internal circulation of suspension (upward/downward). Interactions between constructional, hydrodynamic and kinetic factors were established and discussed. Nucleation and linear growth rates of struvite crystals were calculated on the basis of population density distribution. Kinetic model of idealized Mixed Suspension Mixed Product Removal (MSMPR) crystallizer considering the size-dependent growth mechanism was applied (Rojkowski hyperbolic equation). For comparison purposes the kinetic data corre- sponded to a simpler, continuous draft tube-type crystallizer equipped with propeller agitator were analyzed. It was concluded that crystal product of larger size was withdrawn from the jet-pump DTM crystallizer of the descending flow of suspension in a mixing chamber.
基金financial support from the Polish National Agency for Academic Exchange(NAWA,Polish Returns grant no.PPN/PPO/2019/1/00004/U/0001)acknowledges the National Science Centre,Poland(NCN,OPUS grant no.2020/37/B/ST5/00743)the Dutch Research Council(NWO,Veni grant no.VI.Veni.192.148)。
文摘Fabrication of functional scaffolds for tissue engineering and regenerative medicine applications requires material systems with precise control over cellular performance.3D printing is a powerful technique to create highly complex and multicomponent structures with well-defined architecture and composition.In this review paper,we explore extrusion-based 3D printing methods(EBP,i.e.,Near Field Electrospinning(NFES),Melt Electrowriting(MEW),Fused Deposition Modeling(FDM),and extrusion bioprinting)in terms of their ability to produce scaffolds with bio-instructive properties.These material systems provide spatio-temporal guidance for cells,allowing controlled tissue regeneration and maturation.Multiple physical and biochemical cues introduced to the EBP scaffolds are evaluated in their ability to direct cell alignment,proliferation,differentiation,specific ECM production,and tissue maturation.We indicate that the cues have different impacts depending on the material system,cell type used,or coexistence of multiple cues.Therefore,they must be carefully chosen based on the targeted application.We propose future directions in bio-instructive materials development,including such concepts as metamaterials,hybrid living materials,and 4D printing.The review gathers the knowledge essential for designing new materials with a controlled cellular response,fabrication of advanced engineered tissue,and developing a better understanding of cell biology,especially in response to the biomaterial.