Cellular Pore Research Articles

Multi-interface engineering design of nitrogen-doped bamboo-based carbon/Fe/Fe3C composite electromagnetic wave absorber based on honeycomb-ant nest-like structure

The integration and development of artificial intelligence (AI) and 5G communication technology have brought tremendous changes to human society. How to create a green electromagnetic environment has attracted people's attention. Rich heterostructure design based on interface engineering is considered an effective means of obtaining efficient electromagnetic wave absorbers. In this work, we have achieved innovative design of nitrogen doped carbon/Fe/Fe3C multi-interface heterostructures. The delignification modification of bamboo enriches the cellular pore channels, effectively regulates the loading of Fe3+and the diffusion binding of pyrrole molecules and promotes the deep construction of multi-layer heterogeneous interfaces. Further in-situ pyrolysis resulted in the formation of abundant honeycomb ant nest like structural pores and nitrogen doped multiphase heterostructure interfaces. Provided the best multi-component loss mechanism and impedance matching for the material, improving the overall dielectric and interface polarization effects of the material. Therefore, the obtained absorbent exhibits satisfactory electromagnetic wave absorption performance at a low load of 20 %, with an effective absorption bandwidth of 6.5 GHz (1.85 mm). This work provides new ideas for the high-value utilization of biomass in nature, optimization and innovative design of multi-level pore structures for microwave absorbers.

Assessing porosity limit in freeze‐cast sintered lithium titanate (Li4Ti5O12) materials

AbstractThis study aims to assess the lower limit of porosity that can be achieved in freeze‐cast sintered lithium titanate (LTO) materials while maintaining the characteristic pore directionality. LTO materials were fabricated with solid loading varying in the range of 30–37 vol.%. Sucrose and cationic dispersant were used to vary viscosity and total solute concentration in the aqueous LTO suspensions. Two series of suspension compositions were selected for freeze‐casting. In one series, aqueous suspensions were prepared by mixing deionized (DI) water, sucrose, and LTO powder, while in the other series, aqueous suspensions were prepared by mixing DI water, sucrose, cationic dispersant (1‐hexadecyl)trimethylammonium bromide (CTAB), and LTO powder. With increasing solid loading from 30 to 37 vol.%, porosity in the sintered materials decreased from about 50 to 36 vol.%. LTO materials fabricated from suspensions containing sucrose exhibited well‐developed characteristic freeze‐cast microstructure. Unexpectedly, LTO materials fabricated from suspensions containing sucrose and dispersant exhibited cellular pore morphology irrespective of the solid loading. Sample height had an impact on microstructure evolution in the transition zone and zone length. With the increasing solid loading from 30 to 37 vol.%, the compressive strength of sintered LTO materials having the characteristic freeze‐cast microstructure increased from about 110 to 240 MPa.

Nondestructive internal disorders detection of ‘Braeburn’ apple fruit by X-ray dark-field imaging and machine learning

'Braeburn' apples are susceptible to internal browning disorders when stored under controlled atmosphere (CA) conditions with unfavorable gas compositions. The progression of CA-related disorders in apple tissues is dynamic, noting a decrease in porosity during early storage due to cellular breakdown and pore flooding, and an increase in porosity in later stages due to structural collapse and cavity formation. Utilizing grating-based X-ray dark-field radiography, which leverages X-ray small-angle scattering to detect microstructural changes below the pixel scale, this study assesses the technique's efficacy in identifying internal disorders in 'Braeburn' apples at both early and later stages. A machine learning approach was applied to compare the diagnostic capabilities of dark-field imaging with those of X-ray absorption radiography at identical image resolutions. Results indicate that for early-stage disordered fruit detection, X-ray dark field radiography is 10 % more accurate than absorption radiography, regardless of the machine learning classifiers that were applied. In the later stage of browning, dark-field imaging performs similarly to absorption imaging. High-resolution micro-computed tomography scans suggested that the distinct detection performance of dark-field imaging may be attributed to the more pronounced microstructural differences between healthy and early-stage defective tissues than those between healthy and later-stage defective tissues. The insights from this work will guide the application of X-ray dark-field systems in fruit quality assurance, particularly in detecting internal disorders.

Investigating the Role of a P(VDF−TrFE) Ferroelectric Separator in Li‐Metal Pouch Cells using Electrochemical Impedance Spectroscopy

AbstractThis study explores the efficacy of employing P(VDF−TrFE), a ferroelectric copolymer, to mitigate the formation of dead lithium in Li‐metal anodes when paired with carbonate electrolytes. Employing non‐solvent induced phase separation (NIPS), self‐standing membranes and coatings on polypropylene (PP) separators were prepared, both demonstrating a homogenous cellular pore structure and excellent ionic conductivity. Rigorous evaluation in pouch cell formats, featuring a thin Li‐metal anode (50 μm), a high‐loading NMC532 cathode (3 mAhcm−2), and a carbonate electrolyte, reveals the superior performance of cells with P(VDF−TrFE)‐coated PP separators. Notably, these cells exhibit slower and more consistent capacity fading, as well as the weakest increase in impedance, as evidenced by Electrochemical Impedance Spectroscopy (EIS) investigations. This work underscores the promising role of P(VDF−TrFE) as a key material for addressing challenges associated with dead lithium, offering valuable insights for advancing Li‐metal battery technologies in practical applications.

Ti3C2Tx MXene reinforcement: a nickel-vanadium selenide/MXene based multi-component composite as a battery-type electrode for supercapacitor applications.

Designing innovative microstructures and implementing efficient multicomponent strategies are still challenging to achieve high-performance and chemo-mechanically stable electrode materials. Herein, a hierarchical three-dimensional (3D) graphene oxide (GO) assisted Ti3C2Tx MXene aerogel foam (MXene-GAF) impregnated with battery-type bimetallic nickel vanadium selenide (NiVSe) has been prepared through a hydrothermal method followed by freeze-drying (denoted as NiVSe-MXene-GAF). 3D-oriented cellular pore networks benefit the energy storage process through the effective lodging of NiVSe particles, improving the access of the electrolyte to the active sites, and alleviating volume changes during redox reactions. The 3D MXene-GAF conductive matrix and heterostructured interface of MXene-rGO and NiVSe facilitated the rapid transport of electrical charges and ions during the charge-discharge process. As a result of the synergism of these effects, NiVSe-MXene-GAF exhibited remarkable electrochemical performance with a specific capacity of 305.8 mA h g-1 at 1 A g-1 and 99.2% initial coulombic efficiency. The NiVSe-MXene-GAF electrode delivered a specific capacity of 235.1 mA h g-1 even at a high current density of 12 A g-1 with a 76.8% rate performance. The impedance measurements indicated a low bulk solution resistance (Rs = 0.71 Ω) for NiVSe-MXene-GAF. Furthermore, the structural robustness of NiVSe-MXene-GAF guaranteed long-term stability with a 91.7% capacity retention for successive 7000 cycles. Thus, developing NiVSe-MXene-GAF provides a progressive strategy for fabricating high-performance 3D heterostructured electrode materials for energy storage applications.

Influence of Cell Pore Configuration on Dynamic Mechanical Properties of Honeycomb Structures

With the rapid development of advanced manufacturing technologies such as additive manufacturing, which provides an effective means for processing and preparing a variety of structures with more complex geometrical configurations, the design and study of honeycomb structures have played an important role in promoting the design and study of honeycomb structures. At present, the study of such structures is mainly limited to hexagonal honeycombs, and relatively few studies have been conducted on other cell geometries. In this study, by using the finite element method, we have simulated and investigated the mechanical properties of typical honeycomb structures, in which these structures have different cellular pore configurations and arrangements that are subjected to in-plane low-velocity impact loading. We compared their dynamic load-carrying capacity and deformation patterns with the relative density and impact velocity which is kept constant. Our results show that different cell pore configurations lead to different cell wall stress states during the compression of the honeycomb structure, which affects the macroscopic mechanical properties of the overall structure. Honeycombs with predominantly cell-edge bending have lower stiffness, compressive strength and smoother platform stresses. Honeycombs with deformation modes dominated by cell-wall plastic buckling have the opposite properties. The design of protective structures through further combinatorial optimization of honeycomb structures provides more options to enhance their overall behavior and energy absorption properties.

Thermal, mechanical, and photocatalytic dye degradation performances of the functionalized GO and TiO2 decorated carbon foam composites

Although pitch-derived carbon foam (CF) is not new, but the progress for enhanced thermal, mechanical, and catalytic dye degradations need to be explored. Numerous works were performed to improve the structural morphology and properties of the CFs by dispersing various additives. But mostly it was noticed that such additives enhanced one aspect of the CFs at the cost of other ones. In this work, various additive loadings of the functionalized graphene oxide (FGO), and functionalized titanium dioxide (FTiO2) were synergistically dispersed into the CF matrix via facile pyrolysis for the preparation of CF/FGO and CF/FGO + FTiO2 hybrid composites to improve the structural morphology and properties of the CFs. Functionalization of the graphene oxide (GO) and titanium dioxide (TiO2) nanoparticles (NPs) was performed for the purpose to decrease the possible aggregations, and enhancing the compatibility and interaction between the additives and the CF matrix. A total of seven CF composites including pure CF were synthesized and explored for their structural, thermal, mechanical, and catalytic dye degradation performances. The microstructural investigations revealed that cellular morphology, pore size, shape, and porous homogeneity of the CF composites were significantly improved after the FGO and FTiO2 loadings. The thermal and mechanical behaviors revealed that as the additives loading of the FGO and FTiO2 are increased, the thermal and mechanical responses of the CF composites are significantly improved. The maximum thermal conductivity of 27.9 W/m K was revealed by 4wt.% CF/FGO + FTiO2 hybrid composite. Similarly, the optimum compressive strength of 15.7 MPa, specific compressive strength of 3.5 10 m3, excellent stress–strain, and improved Young's modulus of 42.2 MPa was shown by 4wt.% FGO + FTiO2 hybrid composite. The catalytic activity was evaluated by degrading orange II dye in an aqueous medium under ultraviolet (UV) light irradiation. The TiO2-containing composite was found to be active and the sample with 4wt.% CF/FGO + FTiO2 hybrid composite achieved a significant 78.9% degradation of the dye within just 80 min.

A Versatile Suspended Lipid Membrane System for Probing Membrane Remodeling and Disruption.

Artificial membrane systems can serve as models to investigate molecular mechanisms of different cellular processes, including transport, pore formation, and viral fusion. However, the current, such as SUVs, GUVs, and the supported lipid bilayers suffer from issues, namely high curvature, heterogeneity, and surface artefacts, respectively. Freestanding membranes provide a facile solution to these issues, but current systems developed by various groups use silicon or aluminum oxide wafers for fabrication that involves access to a dedicated nanolithography facility and high cost while conferring poor membrane stability. Here, we report the development, characterization and applications of an easy-to-fabricate suspended lipid bilayer (SULB) membrane platform leveraging commercial track-etched porous filters (PCTE) with defined microwell size. Our SULB system offers a platform to study the lipid composition-dependent structural and functional properties of membranes with exceptional stability. With dye entrapped in PCTE microwells by SULB, we show that sphingomyelin significantly augments the activity of pore-forming toxin, Cytolysin A (ClyA) and the pore formation induces lipid exchange between the bilayer leaflets. Further, we demonstrate high efficiency and rapid kinetics of membrane fusion by dengue virus in our SULB platform. Our suspended bilayer membrane mimetic offers a novel platform to investigate a large class of biomembrane interactions and processes.

Prediction of thermal conductivity of micro/nano porous dielectric materials: Theoretical model and impact factors

With the stupendous latent of microscale and nanoscale technologies in energy conversion and utilization, the design and analysis of porous dielectric materials with open cells have required a more accurate calculation of the radiative thermal conductivity. This work introduces a mathematical model to accurately calculate the radiative thermal conductivity of micro/nanoscale porous open cell structures. Due to the limitations of the existing radiative thermal conductivity models, a full-scale method based on the Rosseland diffusion equation is proposed. Combining this full-scale Rosseland diffusion equation and fractal thermal conduction methods, the predicted total thermal conductivity values were well matched with the experimental results for various microscale and nanoscale porous open cell dielectric materials, with less than 15% error. Besides, seven influential factors on the thermal conductivity including cell size, porosity, cellular pore shape, volume specific surface area, temperature, refractive index, and extinction index were extensively investigated. The results show that the thermal conductivity of porous open cell materials mainly decreased with an increase in extinction index and/or the porous structure's volume specific surface area but increased with increase in temperature. This certainly indicated the potential of the full-scale Rosseland diffusion method for use in the design of specific micro/nanoscale porous dielectric structures like polymer foam in the personal energy management device or the silica aerogel in radiative cooling system.

Fabrication and resonance simulation of 3D-printed biocomposite mesoporous implants with different periodic cellular topologies

In order to achieve more efficient additive materials having precise desired porosities with excellent performance, advanced manufacturing techniques can be put to use. In the present study, 3D printing technology is employed to fabricate mesoporous bioceramic-based bony scaffolds made of various periodic cellular topologies including cubic, cylindrical and hexagonal porosity configurations. The samples are composed of polylactic acid-hydroxyapatite (PLA-HA) mesoporous bioceramic-based nanocomposites. Via the respective experiments, the mechanical properties of the fabricated bony scaffolds are extracted corresponding to each porosity configuration with different pore sizes. Moreover, by using the scanning electron microscopy (SEM), X-ray diffraction (XRD) and the permeability characteristics of the fabricated bio-composite samples after soaking in the simulated body fluid (SBF) are captured. Thereafter, based on the experimentally obtained mechanical properties, the multiple time-scales method is utilized to develop an analytical solution for the nonlinear secondary resonance of PLA-HA mesoporous beam-type implants under subharmonic and superharmonic excitations. The frequency-response and amplitude response associated with the both types of hard excitations are depicted corresponding to different periodic cellular topologies and pore sizes. It is observed that among various periodic cellular topologies, the gap between two branches of the subharmonic frequency-response associated with the cubic and hexagonal ones is maximum and minimum, respectively. In the case of superharmonic excitation, it is found that through reduction of the pore size, the peak of frequency-response and its associated value of the detuning parameter decrease.

Oscillatory behavior of microbubbles impacts efficacy of cellular drug delivery

Drug-loaded microbubbles have been proven to be an effective strategy for non-invasive and local drug delivery when combined with ultrasound excitation for targeted drug release. Inertial cavitation is speculated to be a major mechanism for releasing drugs from drug-loaded microbubbles, but it results in lethal cellular pore damage that greatly limits its application. Thus, we investigated the cellular vesicle attachment and uptake to evaluate the efficiency of drug delivery by modulating the behaviors of targeted microbubble oscillation. The efficiency of vesicle attachment on the targeted cell membrane was 36.5 ± 15.9% and 3.8 ± 2.3% under stable and inertial cavitation, respectively. Further, stable cavitation enhanced cell permeability (26.8 ± 3.2%), maintained cell viability (90.8 ± 2.1%), and showed 7.9 ± 1.9-fold enhancement of in vivo vesicle release on tumor vessels. Therefore, our results reveal the ability to improve drug delivery via stable cavitation induced by targeted microbubbles. We propose that this strategy might be suitable for tissue repair or neuromodulation.

Mineral Characteristics of Low-Rank Coal and the Effects on the Micro- and Nanoscale Pore-Fractures: A Case Study from the Zhundong Coalfield, Northwest China.

The mineral characteristics (occurrence, type, and content) of low-rank coal and their influence on coalbed methane (CBM) reservoirs are investigated at the micro- and nanoscales. Six coal samples of three representative coalmines were used to demonstrate the uniform tectonization from the Zhundong coalfield, NW China. Based on optical microscopy and scanning electron microscopyenergy dispersive spectrum (SEM-EDS) analysis, the mineral composition and occurrence characteristics were discussed. The micro- and nanoscale reservoir characteristics in low-rank coal (pore size distribution and adsorption capability) were studied by diverse methods, including lowtemperature N₂ adsorption/desorption, mercury intrusion porosimetry and CH₄ isotherm adsorption analysis. The coal reservoir nuclear magnetic T₂ spectra of porosity and movable fluid were obtained by combining low-field nuclear magnetic resonance (NMR) analysis, which has an advantage of determining pore fluid technology. The mineral content is highly variable (4˜16 vol.%) in the Xi Heishan prospecting area of the Qitai region. Kaolinite, goyazite, ankerite and anorthosite were microscopically observed to be filling in coal pores and microfractures, and the minerals are given priority to silicate minerals. There is a greater content of mesopores (100-1000 nm) and transition pores (10-100 nm), and they are well connected. The micropores (0-10 nm) are dominated by parallel plate, closed or wedge-shaped pores. Furthermore, the microfractures are mainly observed for types B (width ≥ 5 μm and length≤ 10 mm) and D (width<5 μm and length<300 μm). The results show that microfractures B and C (width< 5 μm and length ≥ 300 μm) are better connected, but the orientation and connectivity of type D are worse. The Langmuir volume and mesopore content decreased with increasing mineral content, which shows that the low-rank coal minerals filled some adsorption space; the reduced CBM adsorption capacity and cellular pore and intergranular pore filled with minerals affect the mesopore content. Therefore, mineral characterization significantly influences methane adsorption capacity and pore structure.

A novel suprachoroidal microinvasive glaucoma implant: in vivo biocompatibility and biointegration

BackgroundA major challenge for any glaucoma implant is their ability to provide long-term intraocular pressure lowering efficacy. The formation of a low-permeability fibrous capsule around the device often leads to obstructed drainage channels, which may impair the drainage function of devices. These foreign body-related limitations point to the need to develop biologically inert biomaterials to improve performance in reaching long-term intraocular pressure reduction. The aim of this study was to evaluate in vivo (in rabbits) the ocular biocompatibility and tissue integration of a novel suprachoroidal microinvasive glaucoma implant, MINIject™ (iSTAR Medical, Wavre, Belgium).ResultsIn two rabbit studies, no biocompatibility issue was induced by the suprachoroidal, ab-externo implantation of the MINIject™ device. Clinical evaluation throughout the 6 post-operative months between the sham and test groups were similar, suggesting most reactions were related to the ab-externo surgical technique used for rabbits, rather than the implant material itself. Histological analysis of ocular tissues at post-operative months 1, 3 and 6 revealed that the implant was well-tolerated and induced only minimal fibroplasia and thus minimal encapsulation around the implant. The microporous structure of the device became rapidly colonized by cells, mostly by macrophages through cell migration, which do not, by their nature, impede the flow of aqueous humor through the device. Time-course analysis showed that once established, pore colonization was stable over time. No fibrosis nor dense connective tissue development were observed within any implant at any time point. The presence of pore colonization may be the process by which encapsulation around the implant is minimized, thus preserving the permeability of the surrounding tissues. No degradation nor structural changes of the implant occurred during the course of both studies.ConclusionsThe novel MINIject™ microinvasive glaucoma implant was well-tolerated in ocular tissues of rabbits, with observance of biointegration, and no biocompatibility issues. Minimal fibrous encapsulation and stable cellular pore colonization provided evidence of preserved drainage properties over time, suggesting that the implant may produce a long-term ability to enhance aqueous outflow.

Characterization of pore structure parameters of foam concrete by 3D reconstruction and image analysis

The pore structure of foam concrete plays a meaningful role for its properties. In this paper, 3D reconstruction technology is applied to the analysis of foam concrete pore structure parameters. Firstly, the 3D point cloud data on the surface of the foamed concrete is obtained by the 3D reconstruction with projecting grating, and the target point cloud is obtained by RANSAC algorithm. The 3D point cloud data is reduced by the orthographic projection to generate a 2D image. Then the pore structure parameters of the foamed concrete are obtained through morphological means such as the unevenness of the edge of the image. In addition, the experimental results are compared with those fruits testing by MIP and Image-J analysis software. The results show that the proposed method has higher accuracy than the Image-J analysis software method in hole recognition and separation. The method proposed in this paper combines 3D reconstruction and image processing, which can effectively avoid the influence of environmental light and other factors on the experimental results in the analysis of cellular concrete pore structure. The pore structure parameters such as porosity, pore size and distribution of foam concrete can be quantified more accurately. This method is expected to be a new means for the analysis of porous materials.

Insights into conjugative transfer of antibiotic resistance genes affected by soil minerals

AbstractWidespread antibiotic resistance genes (ARGs) have caused critical threats to public health on a global scale. Soil, composed mainly of minerals, acts as a source of resistance determinants, playing a considerable role in the development and dissemination of ARGs. The great abundance of ARGs in the soil environment raises concern about the effect of minerals on the spread of ARGs. Herein, the horizontal transfer of a model plasmid pMP2463 containing ARGs from Escherichia coli S17‐1 to Pseudomonas putida KT2440 was monitored following exposure to four common soil minerals, namely, kaolinite, montmorillonite, goethite and birnessite. Birnessite resulted in concentration‐dependent increases in conjugative transfer of plasmid pMP2463 by 1.3–4.3 fold, compared with that in the control group. However, no obvious laws were found in the change of conjugative transfer rate at different concentrations of kaolinite and montmorillonite. As for goethite, the conjugative transfer rate increased firstly and then decreased as the concentration increased. The possible mechanisms underlying birnessite‐induced conjugative transfer of plasmid were explored; birnessite is capable of initiating intracellular reactive oxygen species (ROS) formation, inducing the oxidative stress response. Additionally, birnessite notably facilitated the mRNA expression of the outer membrane protein genes, which contributed to cellular membrane pore formation and horizontal gene transfer, and altered the mRNA expression of conjugative‐related genes that are responsible for conjugative transfer of mobile genetic elements between bacteria. This study triggers questions regarding the potential role of soil minerals in the global dissemination of antimicrobial resistance and provides insights into the interactions between bacteria and minerals in the natural soil environment.Highlights The effect of soil minerals on conjugative transfer of ARGs was explored. Birnessite induced the concentration‐dependent increase of conjugative transfer. Mechanisms underlying ROS formation, membrane permeability increase, gene expression alteration were revealed. Our results provide evidence for the effect of birnessite on antibiotic resistance dissemination.

Silica entry and accumulation in standing trees in a hot‐spring environment: cellular pathways, rapid pace and fossilization potential

AbstractSilicification is the most important process of fossilization resulting in the preservation of internal tissues in plants, thereby providing essential information on the anatomy, life history, and evolution of land plants. However, fundamental knowledge of silica uptake, precipitation, and contribution to in situ plant fossilization is limited. To identify the cellular pathway of aqueous silica and subsequent fluid–wood interaction processes, we investigated upright standing young trees of lodgepole pine (Pinus contorta) in the hot‐spring environment of Cistern Spring, Yellowstone National Park, USA. Our multi‐method analytical approach using x‐ray diffraction, Raman spectroscopy, scanning electron microscopy, and electron probe microanalyses shows that the surficial and internally co‐precipitated silica–halite–gypsum assemblage traces the flow of silica‐rich fluid and documents fluid retention after short‐term hot‐spring water immersion and evaporation. Element distribution maps reveal systematic 2D and 3D differences between silica quantities deposited in earlywood and latewood. The distribution of inorganic impurities in cell walls traces the anatomical structure of the wood and indicates rapid migration of homogeneous fluid into the waterlogged organic substrate. Our results show that the preferential pathway of silica‐rich fluid into the above‐ground wood was through the decorticated periphery which took place during a short‐term flooding, ranging from days to weeks, of hot‐spring fluid. In conclusion, the fluid retention capability in cellular pore space controls the in situ silicification process. The silicification of trees in growth position is a rapid process in which the in vivo transport of silica‐rich fluid upward through the secondary xylem plays an insignificant role.

Sintering Behavior of Highly Porous Ceramic Materials Based on the Al2O3–MgO System

We have studied the sintering of ceramic samples based on magnesium oxide, alumina, and magnesium aluminate spinel in order to assess the conceptual feasibility of producing ceramic foam materials in the Al2O3–MgO system and examined the effect of sintering aids on the sintering process. The range of firing temperatures has been found that ensures the preparation of materials with an open cellular pore structure: the optimal temperatures are from 1600 to 1700°C. The porosity of the synthesized materials is up to 85% and their compressive strength reaches 1.4 MPa.

The microstructure regulation, strengthening, toughening and hydrophilicity of polyamide6 in fabricating poly (vinylidene fluoride)-based flat membrane via the thermally induced phase separation technique

The poly (vinylidene fluoride) (PVDF)/polyamide6 (PA6) flat blend membrane was prepared via thermally induced phase separation (TIPS) process using water-soluble diluent mixture. The function of PA6 to induce the non-solvent induced phase separation (NIPS) was disclosed for the first time and the membrane formation mechanism about S-L phase separation of TIPS by combining the pore-forming effect of PA6 and restricting PVDF crystallization to form somewhat opened cellular pore was proposed. The effect of PA6 on the microstructure of upper surface and matrix was discussed. The hydrophilicity, permeability, anti-fouling capability and anti-fouling mechanism of the membrane were investigated. Interestingly, the morphology of PA6 within the matrix changed from the dispersed phase (particle or fiber) to the continuous phase (network fiber) with the addition of PA6, which in turn increased the breaking strength or breaking elongation and the corresponding mechanisms of strengthening and toughening were developed from the point of crystal particle, fiber and network fiber, respectively. Also, the introduction of PA6 reduced the shrinkage of the membrane, increased the porosity and hydrophilicity, improved the rejection to petroleum ether-in-water emulsion and Congo Red (CR), and enhanced the anti-fouling capacity. This work disclosed the functions of water-insoluble hydrophilic polymer to induce the mass-transfer, pore-forming effect by combining the S-L phase of TIPS and NIPS during the membrane formation process for the first time, presented sample and effective method to tailor the microstructure of membrane and enhance the mechanical property, permeability of membrane via the combination of TIPS and polymer blending for water treatment.

Calcium phosphate-PLA scaffolds fabricated by fused deposition modeling technique for bone tissue applications: Fabrication, characterization and simulation

With the aid of fast development in manufacturing techniques, it is now possible to produce structures with considerable geometrical complexity. In the current investigation, 3D printing machine is utilized to produce beam-type bone implant made of porous polymers with three different periodic cellular topologies. The stress-strain curves and mechanical properties of the bone implants are extracted experimentally corresponding to each porosity shape with various pore sizes. Scanning electron microscope (SEM) is utilized to assess the biological capability in apatite formation on the free surface of the fabricated scaffolds after soaking in the simulated body fluid (SBF). Thereafter, based upon the obtained mechanical properties and using generalized differential quadrature (GDQ) method, the nonlinear primary resonance of bone implants made of the polymer scaffolds and subjected to the soft harmonic excitation is predicted corresponding. The frequency-response and amplitude-response of the bone implants are presented associated with the cubic, spherical and honeycomb periodic cellular topologies and different pore sizes. The analysis of soaked samples in SBF reveals that among different porosity shapes, the samples with cubic and hexagonal porosities have the maximum and minimum permeability, respectively. However, this pattern is vice versa for apatite formation. Moreover, it is seen that for the samples with cubic and hexagonal porosity shapes, the oscillation amplitude as well as the associated excitation frequency at the peak of jump phenomenon are maximum and minimum, respectively.

Ultrastructure of the epidermal gland system of Tetranchyroderma suecicum Boaden, 1960 (Gastrotricha: Macrodasyida) indicates a defensive function of its exudate

Although the phylum Gastrotricha is known and studied for more than 150 years, some cell types, tissues and organ systems are still not well understood in terms of their morphology, ultrastructure, function and role. One of these features is the epidermal gland system (EGS). As yet, there is just a single detailed electron microscopic investigation of the epidermal glands of the species Turbanella cornuta Remane, 1925, plus scattered ultrastructural data of few additional species. We comprehensively investigated the epidermal glands of Tetranchyroderma suecicum Boaden, 1960 by means of serial sectioning and transmission electron microscopy (TEM) and with scanning electron microscopy. Furthermore, light microscopical, confocal laser scanning microscopical and micro-computed tomographical (µCT) techniques were additionally used for this investigation. Computer programs for 3D-reconstructions were used to analyse the data obtained by TEM and µCT. Tetranchyroderma suecicum possesses up to 100, mostly pairwise arranged, glandulocytes. Each single-celled gland contains a large anastomosing secretory cistern with granular content, has a very electron-dense cytoplasm, a basally positioned nucleus, peripherally arranged mitochondria and a cuticulated, ‘chimney-like’ apical neck, which carries the cellular pore. Each merocrine glandulocyte is associated with an adjacent ciliated sensory cell. There is currently no coherent hypothesis of the glandulocytes’ functional role, but different ideas are discussed. We refer to evidence that the secretory product of the EGS of Tetranchyroderma suecicum most likely acts as a repellent against potential predators.