Morphological Investigations Research Articles

Intra-population variability of the saccular, utricular and lagenar otoliths of the garfish Belone belone (Linnaeus, 1760) from South-Western Ionian Sea (Central Mediterranean Sea)

The garfish Belone belone represents the only valid endemic Belone species for the Mediterranean Sea and the eastern Atlantic Ocean. It shows a wide global distribution range, with a high commercial value and ecological relevance in the pelagic domain. Despite this, there needs to be more knowledge regarding the otoliths of this species, with the total absence of descriptions regarding asterisci and lapilli from Mediterranean populations and a lack of studies on the reliability of shape analysis on its sagittae. The present paper aims to provide the first main contours description of the three otoliths pairs from a Mediterranean population, providing an accurate investigation of morphology, morphometry, and intra-specific variability of sagittae, lapilli, and asterisci. Results showed (i) the absence of directional bilateral asymmetry and sexual asymmetry for the three otoliths pairs, (ii) a different morphology and morphometry of sagittae, lapilli and asterisci than those described in the literature, and (iii) an enhanced variability between sagittae morphometry and shape between the three investigated size classes. All these data confirmed the reliability of the studied species of shape analysis, showing a geographical and size-related variability of otoliths features probably related to genetics, environmental conditions, and life habits variations.

Development and electrochemical investigations of enhanced corrosion-resistant Polyvinylcarbazole-TiO2 hybrid nanocomposite coatings on 316L SS for marine applications

The present study focuses on evaluating the corrosion resistance of 316L stainless steel substrates with Polyvinylcarbazole (PVK)/TiO2 hybrid nanocomposite coatings (HNC). Using the chronoamperometry approach, the HNC were electrochemically synthesized on 316L stainless steel substrates, incorporating various weight (%) 1 %, 2 %, 3 % of TiO2 nanoparticles into the PVK matrix. The findings of the surface morphology investigation verified that the 316L SS had a dense and smooth PVK/TiO2 coating. A low surface roughness and high contact value of the PVK/TiO2 coatings are also responsible for the decrease in corrosion rate of the 316L SS. The corrosion protection efficiency of the PVK/TiO2 HNC were investigated through open circuit potential (OCP) measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) analysis in 3.5 wt% NaCl solution. The corrosion rate obtained from the polarization studies of the HNC coatings as follows PVKT-2 < PVKT-3 < PVKT-1 < PVK < 316L SS. Results revealed that an optimal loading of 2 wt% TiO2 nanoparticles significantly enhanced the corrosion resistance of the coating. The enhanced electrochemical impedance response for PVK/TiO2 coatings was verified by EIS experiments. The study demonstrates that the incorporation of TiO2 nanoparticles into the PVK matrix effectively creates a barrier layer at the coating-metal interface, inhibiting the entry of aggressive ions. Microhardness studies revealed the increase in hardness value of the PVK and PVK/TiO2 coatings indicated the protective nature of the coating and provided high mechanical strength to 316L SS. The tape adhesion tests carried out on the coated specimens also indicated a good adhesion of the PVK/TiO2 on the 316L SS surface.

Visible light assisted photocatalytic performance of Europium doped ZnS-Nb2O5 heterostructure for mineralization of Acid violet 7 dye

The present study focuses on the visible light assisted photocatalytic performance of Europium doped ZnS-Nb2O5 heterostructure catalysts for the mineralization of organic pollutants such as Acid violet 7 (AV7) dye. Structural and morphological investigations reveal the presence of wurtzite ZnS and Nb2O5 components in the prepared heterostructure in separate phases. The prepared Europium doped ZnS-Nb2O5 (3Eu50ZN) heterostructures shows enhanced visible light absorption with prominent redshift. Photoluminescence study suggests the presence of surface states/defect energy levels in Europium doped ZnS-Nb2O5 heterostructure catalysts. In comparison to doped and undoped components, the fluorescence lifetime analysis demonstrates enhanced charge separation in 3Eu50ZN heterostructure catalysts. Photo/electrochemical studies reveal superior capacitance behavior, enhanced charge carrier separation, and improved stability in the aqueous phase for 3Eu50ZN heterostructure in comparison to ZnS and Nb2O5 catalysts. The superior visible light assisted photocatalytic performance with 3Eu50ZN heterostructure catalysts was achieved for the mineralization of AV7 dye (20 mg L−1). Active species determination suggests photogenerated holes (h+) to be the major active species responsible for the degradation reaction and a plausible reaction pathway was proposed. The 3Eu50ZN heterostructure catalysts exhibit a recycling nature and demonstrate improved stability.

Synthesis of the oleylamine coated mesoporous Fe3O4 nanospheres and their application towards the efficient chemical fixation of carbon dioxide

The present work reports the successful coating of Fe3O4 nanospheres with oleylamine utilizing a single-step solvothermal technique and its application to carbon dioxide's capture and chemical fixation. The existence of the pure cubic spinel phase of Fe3O4 was established by X-ray diffraction. Fourier transform infrared spectroscopy revealed vibrations corresponding to the oleylamine structure, affirming the coating of oleylamine on Fe3O4 nanospheres. X-ray photoelectron spectroscopy further confirmed the presence of oleylamine on the Fe3O4 surface, along with the constituent elements Fe and O. The nanospheres exhibited a spherical shape with an average diameter of ∼17 nm, shown by morphological investigations. Magnetic properties exhibited a Verwey transition at ∼114 K and a saturation magnetization of ∼60 emu/g. The surface area measurements revealed a pore volume of 0.0717 ccg−1 and surface area of 30.558 m2g-1. The existence of oleylamine on the surface of Fe3O4 nanospheres facilitated the capture of CO2 through chemisorption due to the amine group's high selectivity and the nanospheres' large surface area. In the presence of styrene oxide and tetra-n-hexyl ammonium bromide (THAB), the oleylamine-coated Fe3O4 nanospheres successfully converted CO2 to styrene carbonate. The magnetic core and high thermal stability of the material make it suitable for recyclability for the fixation of CO2 into products with added value. This work presents a promising approach for CO2 capture and utilization using Fe3O4 nanospheres coated with oleylamine, with potential applications in carbon capture and utilization technologies.

Investigation of morphology and volume phase transition of supramacromolecular microgels by NMR spectroscopy and quartz crystal microbalance

AbstractMicrogels have a wide range of applications, from catalysis to biomedical applications such as drug delivery in dispersion, or as surface‐attached materials to improve the biocompatibility of implants or as anti‐fouling coatings. The first aim of this work is to understand the morphology of the supramacromolecular, tannic acid (TA) crosslinked microgels using two‐dimensional 1H NMR spectroscopy, and relaxometry. The second aim is to study the volume phase transition (VPT) of TA‐crosslinked microgels with different crosslinker densities in dispersion using NMR. In this context, 1H high‐resolution NMR spectroscopy is used in combination with the two‐state model and the Boltzmann sigmoidal function to determine thermodynamic quantities of the VPT, such as temperature (Tt), width of transition (ΔTt), and change in entropy (ΔS). Third, surface‐deposited microgels are characterized in terms of their VPT using a quartz crystal microbalance (QCM‐D) to study the properties of these microgels for applications where they are used as coatings. Finally, the Tt of microgels supramolecular crosslinked with TA are compared with microgels covalently crosslinked with N,N′‐methylenebisacrylamide (BIS) in dispersion, using NMR, and deposited on a surface, using QCM‐D. For this purpose temperature‐responsive poly(N‐vinylcaprolactam) and poly(N‐isopropylacrylamide) microgels crosslinked with the plant‐derived polyphenol TA or BIS are used.

One-step synthesis and fabrication of ZrMo2O8 nanostructures as advanced electrode material for energy storage applications

Nanostructures of metal molybdates show great potential as high-performance electrode materials for the forthcoming development of energy storage devices. In present work, ZrMo2O8 nanostructure was constructed using a simple chemical procedure and followed by examination with the aid of several spectral and analytical tools. The supercapacitive properties of ZrMo2O8 electrode material were investigated using Cyclic voltammetry (CV), Galvanostatic charge–discharge (GCD) and Electrochemical Impedance Spectroscopy measurements (EIS). The as-prepared ZrMo2O8 nanostructures as supercapacitor (SC) electrode material exhibited pseudocapacitive performance with notable value of 288C g−1 at 1 A/g, significant cycling stability and 92.5% capacity retention with the coulombic efficiency of 87.4% even after 5000 GCD cycles at 1 A/g. The morphological investigations indicated that the higher Specific capacity (Cs) was primarily caused by the significant increase in active sites as well as active surface area. The Bode phase angle plot of ZrMo2O8 exhibited a low frequency intercept, with emphasis at approximately −52° phase angle, indicating a superior redox signature. The results infered that ZrMo2O8 nanostructures are promising candidates for high performance energy storage applications.

The role of galanin in the progression and prognosis of colorectal cancer: the unfinished story.

The paper presents a summary of immunohistochemical (IHC) and biochemical investigations on the presence of galanin (Gal), one of the neuropeptides abundant in the enteric nervous systems, and three types of its receptors (GalR1-3) in colorectal cancer (CRC) tissue and non-involved colon wall and their associations with clinical-pathological data of the CRC patients. We were the first to morphologically demonstrate the presence of endogenous Gal in CRC sections and measure its content in homogenates of tumor tissue and dissected compartments of unchanged colon wall. The prominent atrophy of myenteric plexuses displaying Gal immunoreactivity (Gal-Ir) located close to the tumor invasion was found to be accompanied by higher Gal content in the tumor-adjacent muscularis externa than in tumor-distant tissue. In further studies for the first time, we demonstrated by the IHC technique the presence of the GalR1-3 receptors in the CRC tumors and the colon mucosa and found that higher GalR3-Ir in the tumor tissue correlated with longer overall survival of CRC patients. Furthermore, we discovered that lower GalR1 expression in submucosal plexuses located near the tumor correlated with a better prognosis in patients with CRC. These findings suggest that GalR1 could be considered as a novel therapeutic target in CRC. In conclusion, our morphological investigations provided novel data documenting the involvement of Gal and its receptors in the progression of CRC and showed the usefulness of the IHC technique for the prognosis of CRC patients.

Investigations of Morphology and Carrier Transport Characteristics in High‐Performance PEDOT:PSS/Tellurium Binary Composite Fibers Produced via Continuous Wet‐Spinning

AbstractFiber‐based flexible thermoelectric (TE) generators are highly desirable due to their capability to convert thermal energy into electricity and their potential applications in wearable electronics. High‐performance poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/Tellurium (Te) composite TE fibers have been successfully developed via a continuous wet‐spinning approach followed by sulphuric acid treatment. With a simple pre‐modification to Te nanowires, the inorganic Te fillers form uniform distribution in PEDOT:PSS. At the optimal condition, the composite fibers exhibit a power factor of 233.5 µW m−1 K−2 and mechanical strength of 205 MPa, which are among the highest values reported so far for the PEDOT:PSS‐based TE fibers. From the viewpoint of TE property enhancement mechanism, understanding the morphology and carrier transport behavior in the 1D organic/inorganic composite fibers remains still challenging. On basis of a series of PEDOT:PSS/Te composite fibers with varying Te fractions, orientations of both the inorganic and organic constituents are quantitatively evaluated. Their electrical conductivities and Seebeck coefficients are also analyzed with modified series‐parallel models and energy filtering theory. This work may not only provide a universal approach to produce high‐performance organic/inorganic composite TE fibers for various wearable applications, but also help to understand the morphology and charge transport between heterogeneous phases in a 1D composite.

Fecal biomarkers in Italian anthropogenic soil horizons and deposits from Middle Ages and bronze age

Archaeological excavations in urban and rural contexts often uncover dark homogeneous anthropogenic deposits, soils and soil horizons, known as Dark Earths, Cultural Layers and Anthrosols. Major scientific questions arise about the processes that lead to the formation of these soils and deposits, as they are often related to a complex combination of environmental, climatic, and anthropogenic factors. Many studies focused on the morphological and physical-chemical investigation of the archaeological remains found as well as the inorganic constituent of the soil. The organic fraction has been only roughly investigated and studies carried out on a molecular level are very limited. However, a more refined investigation of the chemical constituents of these soils can potentially reveal pivotal insights on the archaeological context such as past domestic habits and/or urban organization. It has been demonstrated that, among organic matter constituents, fecal steroids are promising biomarkers to track fecal input in many environmental matrixes such as water, soils, and sediments. In this paper we determine the fecal sterols and stanols content in dark homogeneous anthropogenic deposits and soils found in seven archaeological sites in Italy (from Verona, Como, Florence, Mel and Conegliano) dated from the Late Bronze Age and the Medieval Period, aiming to assess the major contribution of the fecal input using diagnostic fecal indexes obtained from specific fecal sterol proportions. To this purpose, a baseline was established by identifying the fecal fingerprint of domestic herbivores (caprids, ovines, equines and bovines) and omnivores (pigs). Based on their fecal fingerprint, we classified the deposits of seven studied sites into four distinct categories: i) the medieval sites of Verona, presented a strong mixed fecal input from both herbivores and humans; ii) the medieval sites of Como and Florence which showed a similar pattern, with a predominance of human fecal input over livestock; iii) the late medieval soils of Mel and the late bronze age Cultural Layers of Castellar di Leppia (Verona) which exhibited a generally scarce fecal contamination while iv) the final bronze age site of Conegliano (Treviso), a strong fecal contamination from herbivores was detected. These results thus demonstrate that for the Medieval Dark Earth the socio-cultural processes leading to the formation of the Dark Earth differ in terms of sewage and waste management and/or in animal husbandry practices.

Reversible Morphological Remodeling of Prefrontal and Hippocampal Serotonergic Fibers by Fluoxetine.

Serotonin-releasing fibers depart from the raphe nuclei to profusely innervate the entire central nervous system, displaying in some brain regions high structural plasticity in response to genetically induced abrogation of serotonin synthesis. Chronic fluoxetine treatment used as a tool to model peri-physiological, clinically relevant serotonin elevation is also able to cause structural rearrangements of the serotonergic fibers innervating the hippocampus. Whether this effect is limited to hippocampal-innervating fibers or extends to other populations of axons is not known. Here, we used confocal imaging and three-dimensional (3-D) modeling analysis to expand our morphological investigation of fluoxetine-mediated effects on serotonergic circuitry. We found that chronic treatment with a behaviorally active dose of fluoxetine affects the morphology and reduces the density of serotonergic axons innervating the medial prefrontal cortex, a brain region strongly implicated in the regulation of depressive- and anxiety-like behavior. Axons innervating the somatosensory cortex were unaffected, suggesting differential susceptibility to serotonin changes across cortical areas. Importantly, a 1-month washout period was sufficient to reverse morphological changes in both the medial prefrontal cortex and in the previously characterized hippocampus, as well as to normalize behavior, highlighting an intriguing relationship between axon density and an antidepressant-like effect. Overall, these results further demonstrate the bidirectional plasticity of defined serotonergic axons and provide additional insights into fluoxetine effects on the serotonergic system.

Surface parametric influences on the photocatalytic behaviour of zinc oxide nanoparticles

Zinc oxide nanoparticles were chemically synthesised and characterised by UV-DRS spectroscopy, FTIR, scanning electron microscopy with energy-dispersive X-ray diffraction, and X-ray powder diffraction. In order to evaluate the impact of the synthesis process on the structural parameters, Rietveld refinement was done using the GSAS-II programme on experimentally acquired XRD data. ZnO was found to have a hexagonal structure with lattice parameters of a = b =3.247 Å; c = 5.205Å and an average size of about 20-40 nm, as determined by Rietveld refinement of XRD and SEM data. FTIR and EDX analysis was used to confirm the functional group and elemental composition of ZnO NPs. The UV-DRS spectra revealed that the synthesised ZnO had an optical band gap of 3.05 eV. Parametric investigations of the surface morphology of ZnO nanostructures were conducted using the Gwyddion programme. Pseudo-first-order rate kinetics were observed for the photodegradation of two cationic dyes, MB (87.87%) and RhB (74.79%), in the presence of UV light.

Monitoring the Interaction Between Solid Lipid Nanoparticles and Alveolar Macrophages via the Label-Free Technique

Macrophages are employed as targets for delivering genes, drugs, or lipid nanoparticles into tumors or other specific sites. Studying the interaction between solid lipid nanoparticles (SLNs) and macrophages is essential for assessing nanotoxicity and advancing the development of nanomedicines. However, limited data are currently available on the membrane microstructure and biochemical changes that occur when macrophages interact with SLNs. We conducted a label-free morphological and biochemical investigation of NR8383 macrophages using optical diffraction tomography (ODT), which validated the efficiency of the SLNs as a drug delivery system. ODT provided intracellular holotomography to characterize the macrophages and fluorescence imaging to analyze delivery efficiency. ODT analysis revealed the responses of phagocytic macrophages. Additionally, a quantitative analysis of lipid droplets using refractive indices revealed that, compared with incubation with normal cells, incubation with SLNs significantly increased the lipid droplet volume and surface area. The uptake of SLNs into macrophages resulted in increased cell volume, surface area, and concentration, which indicated greater morphological and biochemical variability in the treated cells than in the control cells. The results suggest that ODT imaging is promising for understanding the intracellular distribution of SLNs and useful for validating the efficacy of delivery of SLNs to macrophages.

On the 120th anniversary of A. A. Otelin - scientist, morphologist, pedagogue and organizer

The article presents scientific biography of A. A. Otelin - outstanding morphologist, Doctor of Medical Sciences, Professor, representative of scientific school of Academician V. P. Vorobyov. The contribution of A. A. Otelin into becoming of morphological chairs in medical institutes of Kharkov, Lvov, Vinnitsa, Kishinev, Kursk and Kemerovo and in formation of scientific morphological schools in the regions of the RSFSR and the Republics of the USSR is demonstrated. The particular attention is paid to results of scientific studies of A. A. Otelin in the 1970s carried out jointly with scientists of the Institute of Brain of the USSR Academy of Medical Sciences and the I. P. Pavlov Institute of Physiology of the USSR Academy of Sciences concerning investigation of morphology of sensitive receptors - Vater-Pacini corpuscules.

Characterization and Effect of a Nematophagous Fungus Talaromyces cystophila sp. nov. for the Biological Control of Corn Cyst Nematode.

The dynamic of plant-parasitic nematode populations in soil is closely related to soil microorganisms. Fungi from Heterodera zeae cysts were isolated to explore the phenomenon of decline in the H. zeae population in the soil. Phylogenetic study of partial ITS, BenA, CaM, and RPB2 gene sequences, in addition to morphological investigations, was utilized to identify a nematode-destroyingfungus. The nematicidal activity of a novel strain GX1 against H. zeae was assessed in vitro and in the greenhouse. Our findings revealed that strain GX1 is a new species of Talaromyces, named Talaromyces cystophila. It has a strong parasitic and lethal effect on H. zeae cysts, with 91.11% parasitism on cysts at 3 days after treatment. The contents of second-stage juveniles (J2s) and eggs inside the cysts were degraded and formed dense vacuoles, and the damaged eggs could not hatch normally. The spore suspension exhibited high nematophagous activity against nematodes, and fermentation filtrate exhibited marked inhibition of egg hatching and nematicidal activities on J2s. The hatching inhibition rates of eggs exposed to 1 × 108 CFU/ml spore suspensions or 20% 1-week fermentation filtrate (1-WF) for 15 days were 98.56 and 100%, respectively. The mortality of J2s exposed to 1 × 108 CFU/ml spore suspension reached 100% at 24 h; exposure to 50% 2-WF was 98.65 and 100% at 24 and 48 h, respectively. Greenhouse experiments revealed that the spore suspension and fermentation broth considerably decreased H. zeae reproduction by 56.17 to 78.76%. T. cystophila is a potential biocontrol strain with nematophagous and nematicidal activity that deserves attention and application.

Unraveling the transcriptomic landscape of eye migration and visual adaptations during flatfish metamorphosis

Flatfish undergo a remarkable metamorphosis from symmetrical pelagic larvae to fully asymmetrical benthic juveniles. The most distinctive features of this transformation is the migration of one eye. The molecular role of thyroid hormone in the metamorphosis process in flatfishes is well established. However, the regulatory network that facilitates eye movement remains enigmatic. This paper presents a morphological investigation of the metamorphic process in turbot eyes, using advanced imaging techniques and a global view of gene expression. The study covers migrant and non-migrant eyes and aims to identify the genes that are active during ocular migration. Our transcriptomic analysis shows a significant up-regulation of immune-related genes. The analysis of eye-specific genes reveals distinct patterns during the metamorphic process. Myosin is highlighted in the non-migrant eye, while ependymin is highlighted in the migrant eye, possibly involved in optic nerve regeneration. Furthermore, a potential association between the alx3 gene and cranial restructuring has been identified. Additionally, it confirmed simultaneous adaptation to low light in both eyes, as described by changes in opsins expression during the metamorphic process. The study also revealed that ocular migration activates systems asynchronously in both eyes, providing insight into multifaceted reorganization processes during metamorphosis of flatfish.

A transmission electron microscopy investigation suggests that telocytes, skeletal muscles, myoblasts, and stem cells in common carp (Cyprinus carpio) respond to salinity challenges

BackgroundTelocytes are modified interstitial cells that communicate with other types of cells, including stem cells. Stemness properties render them more susceptible to environmental conditions. The current morphological investigation examined the reactions of telocytes to salt stress in relation to stem cells and myoblasts. The common carp are subjected to salinity levels of 0.2, 6, and 10 ppt. The gill samples were preserved and prepared for TEM.ResultsThe present study observed that telocytes undergo morphological change and exhibit enhanced secretory activities in response to changes in salinity. TEM can identify typical telocytes. This research gives evidence for the communication of telocytes with stem cells, myoblasts, and skeletal muscles. Telocytes surround stem cells. Telopodes made planar contact with the cell membrane of the stem cell. Telocytes and their telopodes surrounded the skeletal myoblast. These findings show that telocytes may act as nurse cells for skeletal stem cells and myoblasts, which undergo fibrillogenesis. Not only telocytes undergo morphological alternations, but also skeletal muscles become hypertrophied, which receive telocyte secretory vesicles in intercellular compartments.ConclusionIn conclusion, the activation of telocytes is what causes stress adaptation. They might act as important players in intercellular communication between cells. It is also possible that reciprocal interaction occurs between telocytes and other cells to adapt to changing environmental conditions.

Investigation of the structure-property relation for graphene oxide based acrylonitrile butadiene styrene nanocomposites

The improvement of the structure-property relation in nanocomposites between different polymer matrices and the embedded nano-additives has become a strategic blueprint for many academic counterparts around the globe. In this work, different loadings of graphene oxide (GO) varied from 1.0 to 3.0 wt. % were mixed with acrylonitrile butadiene styrene (ABS) using solution casting approach. The resulted nanocomposites underwent to spectral, structural, morphological, mechanical, thermal and thermomechanical tests. Different kinds of instruments associated with each test were employed to draw a professional conclusion about the potential improvement in structure-property relation. The targeted improvement was achieved as spectral, structural and morphological investigations confirmed the interaction, structural variation, and good dispersion of GO in ABS; respectively. Furthermore, as GO loadings went higher, the mechanical, thermal, and thermomechanical performances for the nanocomposites were improved compared to the neat polymer. Young’s modulus, tensile strength, thermal decomposition, and visco-elastic properties showed an enhancement compared to the neat polymer. The mechanical and thermomechanical performances for the nanocomposites recorded significant promotions.

Magnetically separable and visible light-driven photocatalytic activity of graphene oxide based α-Fe2O3 nanocomposite

This work investigates the impact of graphene oxide (GO) on the structural, morphological, optical, and photocatalytic investigations of Fe2O3, an excellent photocatalyst for industrial wastewater treatment. Using the straightforward and inexpensive sol-gel auto-combustion, hummer's method and sonication method, Fe2O3 nanoparticle (NPs), GO nanosheet, and GO-based Fe2O3 (GO/Fe2O3) nanocomposite have been synthesized, respectively. The XRD patterns, Raman spectra, and FTIR spectroscopy were used for the structural analysis, which verifies the single phase hexagonal geometry of Fe2O3 NPs. The average size of the crystallites is seen to have reduced from 50 nm to 44 nm for Fe2O3 and GO/Fe2O3. The SEM along with EDS were applied to investigate the surface morphology and confirm the existence of the elements Fe and O in pure Fe2O3, and C, Fe and O in GO/Fe2O3. From UV–vis absorbance spectra, the decrease in optical band gap (2.5 eV–1.9 eV) caused by GO incorporation has been inferred, as clearly displayed in the Tauc plots. X-ray photoelectron spectroscopy (XPS) confirms the presence of Fe2+/Fe+3 ionic states and large oxygen vacancies in the GO/Fe2O3 nanocomposite. The photocatalytic properties of both materials for the toxic MB (methylene blue) dye photodegradation in an aqueous solution was evaluated while being exposed to sunlight. It makes an excellent choice for wastewater treatment due to the high photocatalytic activity of magnetically separable GO/Fe2O3 nanocomposite for decomposing the MB dye.

Improvement of Osteogenic Differentiation of Mouse Pre-Osteoblastic MC3T3-E1 Cells on Core-Shell Polylactic Acid/Chitosan Electrospun Scaffolds for Bone Defect Repair.

Electrospun hybrid scaffolds composed of synthetic and natural polymers have gained increasing interest in tissue engineering applications over the last decade. In this work, scaffolds composed of polylactic acid electrospun fibers, either treated (P-PLA) or non-treated (PLA) with air-plasma, were coated with high molecular weight chitosan to create a core-shell microfibrous structure. The effective thickness control of the chitosan layer was confirmed by gravimetric, spectroscopic (FTIR-ATR) and morphological (SEM) investigations. The chitosan coating increased the fiber diameter of the microfibrous scaffolds while the tensile mechanical tests, conducted in dry and wet environments, showed a reinforcing action of the coating layer on the scaffolds, in particular when deposited on P-PLA samples. The stability of the Chi coating on both PLA and P-PLA substrates was confirmed by gravimetric analysis, while their mineralization capacity was evaluated though scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) after immersing the scaffolds in simulated body fluids (SBF) at 37 °C for 1 week. Sample biocompatibility was investigated through cell viability assay and SEM analysis on mouse pre-osteoblastic MC3T3-E1 cells grown on scaffolds at different times (1, 7, 14 and 21 days). Finally, Alizarin Red assay and qPCR analysis suggested that the combination of plasma treatment and chitosan coating on PLA electrospun scaffolds influences the osteoblastic differentiation of MC3T3-E1 cells, thus demonstrating the great potential of P-PLA/chitosan hybrid scaffolds for bone tissue engineering applications.

Influence of TEMPO-oxidation on pulp fiber chemistry, morphology and mechanical paper sheet properties

In this contribution, we report on the TEMPO-mediated oxidation of pulp fibers used in the general context of papermaking and for the future design of tailor-made paper in advanced applications. We focus in our studies on properties of TEMPO-oxidized pulp fibers to explain the characteristics of the paper made thereof. 13C solid-state NMR analysis reveals that in particular amorphous regions of the fibers are being chemically oxidized, while at the same time the crystalline regions of the fibers are not significantly affected. Investigation of the fiber morphology before and after oxidation shows that the fiber length is not changed, yet the fibers do exhibit an increase in width if in contact with water, which is attributed to an increase in fiber swelling. In addition, fibrillation decreases due to the oxidative removal of loosely bound fines and fibrils, rendering the surface of the resulting oxidized fibers much smoother in comparison to the original fibers. Finally, we observe that both, dry and wet tensile strengths are also higher for paper made of oxidized fibers, most likely due to cross linkable aldehyde groups formed during oxidation (i.e. hemiacetal bond formation in the sheet during thermal drying). Our results of the oxidation of paper fibers thus offer a systematic study helpful for the design of tailor-made paper useful in several applications where a fiber-modification with fiber-immobilized functional motifs is crucial, such as for example in paper-based microfluidic sensors (µPADs) or lab-on a chip-devices.