Polarized Light Microscopy Research Articles

Effects of different oleogelators on the structural properties and composition of iron walnut-oil oleogels

In this study, we compared the quality of iron walnut oil (IWO) oleogels prepared with different oleogelators, including γ-oryzanol/β-sitosterol (OZ-PS), γ-oryzanol/triglyceride (OZ-TC), monoglycerides (MGS), beeswax (BW), beeswax-monoglycerides (BW-MGS), and carnauba wax (CW). The physicochemical and component properties, rheological and textural parameters, macroscopic morphologies, and antioxidant capacities of the resulting oleogels were analyzed. In addition, their microscopic properties were analyzed using Fourier-transform infrared (FTIR), X-ray powder diffraction (XRD) spectroscopy, and polarized light microscopy (PLM). The results showed that the gel structures produced by different oleogelators did not change the fatty acid composition of IWO. In addition, the IWO oleogel prepared with OZ-PS had a more stable network structure, excellent hardness at 4℃ (1116.51 g), better antioxidant capacity (766.50 μmol TE/kg) and higher total phenolic content (14.98 mg/kg) than any other experimental IWO oleogels. Moreover, comprehensive ranking by principal component analysis of numerous characteristics showed that the OZ-PS oleogel (2.533) ranked first among the six oleogels studied. Therefore, the IWO oleogel prepared with OZ-PS is a promising product, and our results provide guidance for the preparation of IWO oleogels, such as to increase their applications in the food industry.

The key to ancient Roman mortars hydraulicity: ceramic fragments or volcanic materials? A lesson from the Phlegrean archaeological area (southern Italy)

This research deals with mineralogical, petrographic, chemical, and microstructural characterization of raw materials from the Roman Dragonara cave (Phlegraean Fields, Campania region, Italy) through Polarized Light Microscopy (PLM), X-ray Powder Diffraction (XRPD), Field Emission Scanning Electron Microscopy coupled with an Energy Dispersive Spectrometer (FESEM/EDS), Simultaneous Thermal Analysis (STA) and Mercury Intrusion Porosimetry (MIP). The aim of this study was to asses mortars hydraulic properties along with provenance of raw materials and mortars recipe. A focus on the reactions between the surface of the ceramic aggregates and volcanic materials with binding matrix proved to be crucial to define their role in the mix design of mortars. Representative results showed that hydraulicity of the analyzed mortars is mainly due to volcanic materials rather than ceramic fragments. In fact, reaction active elements such as Reaction Rims (RR), Interfacial Transition Zones (ITZ) and particularly Ca-rich rims were usually found at the matrix-volcanic fragments interface. Moreover, porosity tests evidence that bedding mortars, which contain mainly volcanic material and only sporadically ceramic fragments have a higher closed porosity of binder matrix due to the good pozzolanic reactivity.

Comparing age- and bone-related differences in collagen fiber orientation: A case study of bats and laboratory mice using quantitative polarized light microscopy.

As bones age in most mammals, they typically become more fragile. This state of bone fragility is often associated with more homogenous collagen fiber orientations (CFO). Unlike most mammals, bats maintain mechanically competent bone throughout their lifespans, but little is known of positional and age-related changes in CFO within wing bones. This study tests the hypothesis that age-related changes in CFO in big brown bats (Eptesicus fuscus) differ from those of the standard mammalian model for skeletal aging, the C57BL/6 laboratory mouse. We used data from quantitative polarized light microscopy (qPLM) to compare CFO across the lifespan of long-lived big brown bats and age matched C57BL/6 mice. Eptesicus and C57BL/6 mice displayed idiosyncratic patterns of CFO. Consistent age-related changes were only apparent in the outer cortical bone of Eptesicus, where bone tissue is more longitudinally arranged and more anisotropic in older individuals. Both taxa displayed a ring of more transversely oriented bone tissue surrounding the medullary cavity. In Eptesicus, this tissue represents a greater proportion of the overall cross-section, and is more clearly helically aligned (arranged at 45° to the bone long axis) than similar bone tissue in mice. Bat wing bones displayed a proximodistal gradient in CFO anisotropy and longitudinal orientation in both outer and inner cortical bone compartments. This study lays a methodological foundation for the quantitative evaluation of bone tissue architecture in volant and non-volant mammals that may be expanded in the future.

Broadband scattering properties of articular cartilage zones and their relationship with the heterogenous structure of articular cartilage extracellular matrix.

Articular cartilage exhibits a zonal architecture, comprising three distinct zones: superficial, middle, and deep. Collagen fibers, being the main solid constituent of articular cartilage, exhibit unique angular and size distribution in articular cartilage zones. There is a gap in knowledge on how the unique properties of collagen fibers across articular cartilage zones affect the scattering properties of the tissue. This study hypothesizes that the structural properties of articular cartilage zones affect its scattering parameters. We provide scattering coefficient and scattering anisotropy factor of articular cartilage zones in the spectral band of 400 to 1400nm. We enumerate the differences and similarities of the scattering properties of articular cartilage zones and provide reasoning for these observations. We utilized collimated transmittance and integrating sphere measurements to estimate the scattering coefficients of bovine articular cartilage zones and bulk tissue. We used the relationship between the scattering coefficients to estimate the scattering anisotropy factor. Polarized light microscopy was applied to estimate the depth-wise angular distribution of collagen fibers in bovine articular cartilage. We report that the Rayleigh scatterers contribution to the scattering coefficients, the intensity of the light scattered by the Rayleigh and Mie scatterers, and the angular distribution of collagen fibers across tissue depth are the key parameters that affect the scattering properties of articular cartilage zones and bulk tissue. Our results indicate that in the short visible region, the superficial and middle zones of articular cartilage affect the scattering properties of the tissue, whereas in the far visible and near-infrared regions, the articular cartilage deep zone determines articular cartilage scattering properties. This study provides scattering properties of articular cartilage zones. Such findings support future research to utilize optical simulation to estimate the penetration depth, depth-origin, and pathlength of light in articular cartilage for optical diagnosis of the tissue.

Correlation analysis of various characteristics of fly ash based on particle separation

Due to the diversity of fly ash particles, it is a scientific way to promote the comprehensive utilization of fly ash with high efficiency to sort and classify the particles. The correlation between sorting indices and various characteristics of fly ash is the theoretical basis for its separation and classified application. In this paper, fly ash from three different coal-fired power stations is separated according to particle size and apparent density. The composition, morphology, and pozzolanic activity of the separated fly ash particles were characterized by several test techniques including X-ray fluorescence, X-ray diffraction, polarized light microscopy, scanning electron microscopy and lime absorption test. The correlation laws between different characteristics common to three types of fly ash were analyzed. The results show that the alkaline oxide (CaO+MgO+K2O+Na2O) content of fly ash varies accordantly with particle size, apparent density, glass phase content and pozzolanic activity. 40 µm and 80 µm are the critical particle size for the obvious change of glass phase content and microstructure of fly ash particles, and 2.5 g·cm−3 is the critical apparent density for the change of phase composition. Pozzolanic activity is determined together by alkaline oxide content and acid oxide (SiO2 +Al2O3) content, and there is no obvious single factor relationship between pozzolanic activity and particle size or apparent density.

Fracturing and widening of grain boundary networks in quartz, plagioclase and olivine crystal aggregates during exhumation at low P-T conditions

Grain boundary networks of quartz, plagioclase and olivine crystal aggregates in metamorphic rocks have been investigated from the nanometer to the millimeter scale by polarized-light microscopy, SEM, and TEM. The studied materials show different grain sizes and experienced different retrograde P-T histories. The aggregates of quartz and plagioclase are traversed by networks of ∼90% continuously open boundaries with μm-sized cavities along the boundaries or at triple junctions. The boundaries are up to ∼500 nm wide open with typically parallel opposing grain faces. Olivine boundaries are filled with serpentine that does not replace olivine but fills the initially open space homogeneously and mostly with random orientation. For quartz there is no correlation between the crystallographic orientation of grain boundaries and their widths. Amongst all samples analyzed, a weak positive correlation exists between grain size and width of open grain boundaries. The application of measured volume changes and elasticity data from the literature to the cooling-decompression paths of the analyzed materials suggests that fracturing with subsequent widening of the grain boundaries starts at temperatures recognizably below the transition from crystal-plastic to brittle behavior of quartz, plagioclase and olivine but not only under surface conditions. The high amount of open boundaries causes an extensive permeability.

Diagenesis of the Permian Fengcheng Formation in the Mahu Sag, Junggar Basin, China

The Fengcheng Formation in the Mahu sag of the Junggar Basin was primarily composed of detritus, pyroclastic material, carbonates, and evaporites. In order to establish the diagenesis pathways of the Fengcheng Formation, some methods of polarized light microscope, SEM, CL, EPMA, LR, and fluid inclusion analysis were applied to discuss the diagenesis process. The results showed the following: (a) The formation of an alkaline lake was the result of the influence of a high concentration of sodium-rich sources, and it led to the preservation of alkaline minerals in the stratum. (b) After the sediments were buried, three mineral assemblages were formed in the Fengcheng Formation, which are carbonate mineral assemblages (i.e., calcite + ferreous dolomite), reedmergnerite and carbonate mineral assemblages (i.e., reedmergnerite + calcite + ferreous dolomite), and reedmergnerite and alkaline mineral assemblages (i.e., reedmergnerite + shortite + trona), respectively. (c) According to the homogenization temperature of reedmergnerite primary fluid inclusions, the alkaline diagenesis of Fengcheng Formation was divided into an early stage (≤100 °C) and a middle stage (>100 °C), respectively. The earlier stage is marked by the formation of ferrous saddle dolomite, quartz dissolution, and the agglutination of laumontite. These processes occurred under normal burial conditions. The latter is marked by the reedmergnerite’s appearance, which is correlated with the deep hydrothermal activity controlled by faults. (d) Based on sedimentary and diagenetic factors, including climate, provenance, diagenetic surroundings, and the action of subsurface fluid, the alkaline deposition-diagenesis model for shale series in four stages of the Fengcheng Formation was established.

Cholesteric nanostructure biosensors on flexible paper fibres for disease detection through label-free techniques and image analysis

ABSTRACT We have achieved a successful synthesis of a label-free, flexible, portable, and colour-indicating biosensor using cholesteric nanostructure liquid crystals (LCs), commonly referred to as cholesteric LCs (CLCs), on paper fibres. This innovative approach holds significant promise for rapid screening in precision medicine and other applications. We incorporated optically active nematic LCs in various configurations within CLCs, allowing them to rotate along different axes. When exposed to light, these LCs reflected light at specific wavelengths. By employing polarised optical microscopy and a charged couple device (CCD), we conducted titration experiments with bovine serum albumin (BSA) on the paper substrate and quantified protein concentrations based on the observed colour shifts. Utilising internal Python pixel analysis software, we evaluated the red, green, and blue colour components, which served as biomarkers for different BSA concentrations. Our results demonstrated a linear correlation between BSA concentration and colour variations. This CLC-based paper-substrate biosensor exhibits the potential to efficiently screen a large number of samples, thereby enhancing the diagnostic accuracy in clinical settings. Combining the colour-indicating and quantifiable attributes of CLCs with the affordability and portability of paper substrates, we have developed a versatile biosensor. Its ease of use, rapid response, and high sensitivity make it a promising tool for future disease detection endeavours.

Mineralogy of Recent Sediments of Al-Teeb River Basin-East Missan Governorate, Southeastern Iraq

This research aims to define the mineralogical composition of recent sediments that were deposited around the Al-Teeb River basin in the east Missan Governorate and try to determine the provenance or the source of these sediments. The study area represents the southeastern edge of the Mesopotamian Plain and is part of it. 15 samples were collected from eight stations of recent sediment that was deposited around the Al-Teeb River; two field works are covered (December 2019 and August 2021). Mineralogical study of the sediment after separating the light and heavy minerals by heavy liquid Bromoform in order to determine the mineralogical composition of the studied samples by using the petrographic microscope the light mineral fraction composed (95.5%) of the total mineralogy. The light components of these sediments consist mainly of quartz about 25.31%, feldspars (potash and plagioclase feldspar) about 9.53%, sedimentary rock fragments (carbonate rock fragments up to 33.39%, chert rock fragments 7.65%, evaporates fragments, 7.31%), (igneous rock fragments, and metamorphic rock fragments about 6.94%). The major component of the heavy minerals residue is opaque minerals with a range of 36.76% and non-opaque minerals with a range of 63.24%. The non-opaque minerals are mainly of chlorite 7.42%, pyroxenes composed of both orthopyroxene and clinopyroxene 6.37%, amphiboles composed of hornblende, glaucophane, and tremolite 7.02%, (mica: biotite and muscovite) 9.81%, zircon 7.54%, tourmaline 5.1%, epidote group 5.91%, rutile 4.5%, kyanite 2.2%. The sediments have two types of stability: moderately stable and ultra-stable. The mineralogical composition shows that the major sources of these sediments are; the river terraces and flood plain of the river in the Mesopotamian Plain, another source of these sediments is the aeolian deposits that separated from sand dune fields in the studied area, and outcrops of ancient sedimentary formations in the southeastern of Iraq as specified by the incidence of the carbonate rock fragments.

Unsupervised learning of pixel clustering in Mueller matrix images for mapping microstructural features in pathological tissues

In histopathology, doctors identify diseases by characterizing abnormal cells and their spatial organization within tissues. Polarization microscopy and supervised learning have been proved as an effective tool for extracting polarization parameters to highlight pathological features. Here, we present an alternative approach based on unsupervised learning to group polarization-pixels into clusters, which correspond to distinct pathological structures. For pathological samples from different patients, it is confirmed that such unsupervised learning technique can decompose the histological structures into a stable basis of characteristic microstructural clusters, some of which correspond to distinctive pathological features for clinical diagnosis. Using hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) samples, we demonstrate how the proposed framework can be utilized for segmentation of histological image, visualization of microstructure composition associated with lesion, and identification of polarization-based microstructure markers that correlates with specific pathology variation. This technique is capable of unraveling invisible microstructures in non-polarization images, and turn them into visible polarization features to pathologists and researchers.

Color origin and its sedimentary and paleoenvironmental significance of the Permian-Triassic strata in the Ordos Basin, China

The Permian-Triassic strata in the Ordos Basin deposit a colorful set of strata. Although there have been many studies on oil and gas resources here, little attention has been paid to the genesis mechanism of its color. To analyze the color origin of the Permian-Triassic claystones and to clarify the dialectical relationship between rock color and sedimentary environment, petrological and geochemical methods such as polarization microscope, scan electron microscope, X-ray diffractometer, and inductively coupled plasma-mass spectrometer are used. The results indicate that the minerals with different colors, composition, and content serve as colorants in sedimentary rocks, with the predominant dyeing component in dark claystones being the organic matter, whereas red beds primarily acquire their color from hematite and other ferric minerals. In addition, different rock colors correspond to distinct chemical composition variations. The black-gray rocks of the Yanchang and Shihezi Formations have high total organic carbon content, Fe2+/Fe3+, V/Cr, and low CaO/(MgO × Al2O3) and Sr/Cu, whereas the red-brown rocks of the Liujiagou and Heshanggou Formations exhibit the opposite. Therefore, different colors of the rocks stem from their different mineral and chemical compositions, which in turn influenced by the changes in the paleoclimate, paleoenvironment, and tectonic movements. Comprehensive analysis of color, mineral, and chemical composition reveals the evolution process of paleoclimate and paleoenvironment in the Ordos Basin from the late Permian to Triassic, beginning with a warm humid climate characterized by a weak oxidation environment in the Shihezi and Shiqianfeng Formations, transitioning to a hot arid climate in the Liujiagou and Heshanggou Formations, and returning to a warm humid climate with a weak oxidation environment in the Zhifang and Yanchang Formations. This evolution history aligns with the global tectonic and climate evolution. Overall, systematic analysis of sedimentary rock color can provide an important basis for the study of the paleoclimate and paleoenvironment.

Cationic tantalum oxide nanoparticle contrast agent for micro computed tomography reveals articular cartilage proteoglycan distribution and collagen architecture alterations

ObjectiveCationic tantalum oxide nanoparticles (Ta2O5-cNPs), as a newly introduced contrast agent for computed tomography (CT) of cartilage, offer quantitative evaluation of proteoglycan content and biomechanical properties. However, knowledge on the depth-wise impact of cartilage constituents on NP diffusion, particularly the influence of the collagen network, is lacking. In this study, we aim to establish the depth-dependent relationship between Ta2O5-cNP diffusion and cartilage constituents (proteoglycan content, collagen content and network architecture). MethodsOsteochondral samples (n = 30) were harvested from healthy equine stifle joints (N = 15) and the diffusion of 2.55 nm diameter cationic Ta2O5-cNPs into the cartilage was followed with µCT imaging for up to 96 hours. The diffusion-related parameters, Ta2O5-cNP maximum partition (Pmax) and diffusion time constant, were compared against biomechanical and depth-wise structural properties. Biomechanics were assessed using a stress-relaxation and sinusoidal loading protocols, whereas proteoglycan content, collagen content and collagen network architecture were determined using digital densitometry, Fourier-transform infrared spectroscopy and polarized light microscopy, respectively. ResultsThe Pmax correlates with the depth-wise distribution of proteoglycans (bulk Spearman’s ρ = 0.87, p < 0.001). More open collagen network architecture at the superficial zone enhances intake of Ta2O5-cNPs, but collagen content overall decreases the intake. The Pmax values correlate with the equilibrium modulus (ρ = 0.80, p < 0.001) of articular cartilage. ConclusionThis study establishes the feasibility of Ta2O5-cNPs for the precise and comprehensive identification of biomechanical and structural changes in articular cartilage via contrast-enhanced µCT.

Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa

Abstract The occurrence of microplastics in water, their chemistry, physical characteristics, and the efficiency of public wastewater treatment work (WWTW) processes in the removal of microplastics are investigated. Samples were collected from the period 2021 December to 2022 September from two WWTWs in Johannesburg East using 24-h autosamplers. The microplastics were imaged using polarised optical microscopy (POM) and the images were processed using image J 1.53 K to determine the particle counts. The total concentration of microplastics at WWTW A was 3,098 MP/L while WWTW B had 3,561 MP/L. The microplastics identified across the seasons were dominated by angular, fibres, fragments, and films. Fourier transforms infrared (FTIR) spectroscopy identified the polymers such as polyethylene, acrylic, polyethylene terephthalate, and polystyrene in WWTW A and B influent while identifying the polymers such as polystyrene, polyacrylamide, polypropylene, polycarbonate, acrylonitrile butadiene styrene, poly(ethyl cyanoacrylate), carboxyl, poly(ethylene terephthalate), polyethylene, poly(methyl methacrylate), and cellulose in the final effluent. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) identified Cr, Ca, Fe, Al, Na, Mg, Zn, Cl, P, S, and silicon as additives to microplastics with high-intensity peaks of oxygen and carbon. It is recommended to monitor and regulate microplastics in discharged effluents from WWTWs to minimise environmental pollution.

Comparative Characteristics of Granulomatous Lesions in the Lungs in Tuberculosis, Talcosis, and Cryptococcosis in Patients with HIV Infection/AIDS

Objrctive — to refine the process of differential diagnosis of morphological and immunohistochemical manifestations of granulomatous inflammation in the lungs of patients with tuberculosis, cryptococcosis and talcosis in conjunction with infection caused by the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Additionally, to compare the morphological features of inflam­matory cell reactions. Materials and methods. A retrospective cohort analysis of 400 medical records of hospitalized patients was conducted from 2010 to 2022. Based on inclusion criteria, 75 patients with laboratory-confirmed HIV infection, aged 25 to 75 years, were selected. Protocols of pathological studies were analysed, histological specimens were reviewed, and additional investigations were conducted. Depending on clinical data and autopsy results, patients were divided into three groups: 30 with tuberculosis in conjunction with HIV infection/AIDS, 25 with talc granulomatosis and HIV infection/AIDS and 20 with cryptococcosis in conjunction with HIV infection/AIDS. General morphological, histochemical and immunohistochemical features of lung lesions, as well as the nature and manifestations of the inflammatory cell reaction, were determined using standard histological staining (hematoxylin and eosin), polarization microscopy, histochemical methods (van Gieson staining, PAS reaction) and immunohistochemical analysis (deter­mination of CD4, CD8, CD68, CD20 marker expressions). Results and discussion. The pathomorphological characteristics of lung lesions in groups 1 and 3 are polymorphic and represented by multiple foci of necrosis, focal fibrosis, a weak inflammatory cell reaction, as well as the accumulation of an alteration agent, in group 2 — in the form of an inflammatory cell reaction with the formation of a granulomas. Weak small-focal diffuse expression of CD4 and CD8 markers was determined in all studied samples, different large-focal expression of CD20 and CD68 markers was observed, localized mainly around the inclusion talc in group 2. Conclusions. The application of a comprehensive approach (histological, histochemical, immuno­histochemical investigation and polarization microscopy) in diagnosing granulomatous lung lesions in patients with HIV infection/AIDS enhances the verification of the etiological factor and expands diagnos­tic capabilities. The spectrum of morphological changes in patients with granulomatous lung lesions is polymorphic and depends on various factors. Significant differences are observed in the manifestations of alterative-necrotic, fibrotic changes and immune reactions both within and between groups, justifying the need for an individualized approach in the diagnostic and therapeutic process.

Rice Derivatives in Hair Protecting

The research was carried out on a hair conditioner containing the following rice derivatives individually: rice germ oil, rice germ oil GX-N, and riceterol esters. To evaluate the protective efficacy of the three active ingredients chosen, the following techniques were used: FT-IR, SEM, stress–strain test, and polarized light microscopy analysis. The tests were carried out on natural Caucasian hair. The methodologies were found to be suitable for the evaluation and led to interesting results: the selected ingredients showed good properties in improving the hair. The conditioners containing the active ingredients restored the properties of the hair even when subjected to stress such as irradiation. In this case, the most effective was the rice germ oil GX-N.

Novel Organogels from Mauritia flexuosa L.f and Caryodendron orinocense Karst.: A Topical Alternative.

Organogels have importance for topical applications because they can be used to deliver drugs in a controlled and prolonged fashion. These are materials consisting of a three-dimensional network of organic molecules dispersed in a solvent. Recent studies have demonstrated that the solvent could be replaced by oils from non-conventional biologic sources. There is a diversity of not-explored species in the Amazon that are promising sources of vegetable oils with a promising composition. This study developed an organogel with buriti (Mauritia flexuosa L.f) and cacay (Caryodendron orinocense Karst.) oils, using cetostearyl alcohol as an organogelator due to its compatibility, stability, security, affordability, and it is readily available. The oils were characterized, and the organogels were synthesized by studying their crystal evolution and oil-binding capacity. The microstructure was evaluated with polarized light microscopy, fractal dimension, FTIR spectroscopy, XRD, and thermal and rheological analyses. It was found that the critical gelation concentration was higher for cacay oil as it possessed a higher amount of polyunsaturated triacylglycerols. The crystals of the buriti organogel had a smaller lamellar shape, a greater surface area, and physical and thermal stability; although, it presented a slower crystal evolution due to the low number of minor compounds and a greater number of saturated triacylglycerols. The polar fraction of the organogelators as well as triacylglycerol and minor polar compounds are important in forming crystallization nuclei. The study showed that Amazonian oils in crystallization processes form microstructures with differentiating physicochemical properties.

BMP9 is a potent inducer of chondrogenesis, volumetric expansion and collagen type II accumulation in bovine auricular cartilage chondroprogenitors.

Reconstruction of the outer ear currently requires harvesting of cartilage from the posterior of the auricle or ribs leading to pain and donor site morbidity. An alternative source for auricular reconstruction is in vitro tissue engineered cartilage using stem/progenitor cells. Several candidate cell-types have been studied with tissue-specific auricular cartilage progenitor cells (AuCPC) of particular interest. Whilst chondrogenic differentiation of competent stem cells using growth factor TGFβ1 produces cartilage this tissue is frequently fibrocartilaginous and lacks the morphological features of hyaline cartilage. Recent work has shown that growth factor BMP9 is a potent chondrogenic and morphogenetic factor for articular cartilage progenitor cells, and we hypothesised that this property extends to cartilage-derived progenitors from other tissues. In this study we show monoclonal populations of AuCPCs from immature and mature bovine cartilage cultured with BMP9 produced cartilage pellets have 3-5-fold greater surface area in sections than those grown with TGFβ1. Increased volumetric growth using BMP9 was due to greater sGAG deposition in immature pellets and significantly greater collagen accumulation in both immature and mature progenitor pellets. Polarised light microscopy and immunohistochemical analyses revealed that the organisation of collagen fibrils within pellets is an important factor in the growth of pellets. Additionally, chondrocytes in BMP9 stimulated cell pellets had larger lacunae and were more evenly dispersed throughout the extracellular matrix. Interestingly, BMP9 tended to normalise the response of immature AuCPC monoclonal cell lines to differentiation cues whereas cells exhibited more variation under TGFβ1. In conclusion, BMP9 appears to be a potent inducer of chondrogenesis and volumetric growth for AuCPCs a property that can be exploited for tissue engineering strategies for reconstructive surgery though with the caveat of negligible elastin production following 21-day treatment with either growth factor.

Thermal and structural behavior of mango (Mangifera indica L) kernel fat from three Ivorian varieties

AbstractMango (Mangifera indica L.) seeds is an interesting source of fat, rich in stearic (St) and oleic (O) acid with three major triacylglycerols (TAG): StOSt, StOO, and StLSt. The kernel fat content and quality depend however on the varieties and their origin. The objective of this study was to investigate the crystallization and polymorphic behavior of mango kernel fat extracted from three selected Ivorian varieties which differ in terms of TAG composition: Kent (KT), Djakoumankoun (DN) and Brooks (BR). The isothermal crystallization behavior was examined at 15 and 20°C by pulsed nuclear magnetic resonance, differential scanning calorimetry, x‐ray diffraction (XRD) and polarized light microscope. Under static conditions, DN crystallized faster, followed by BR, then KT. At 15°C, an unusual evolution was observed for both DN and BR, which can be explained by a melt‐mediated polymorphic transition from α into more stable forms. Using a differential scanning calorimetry (DSC) stop‐and‐return technique, different crystallization behaviors were also observed. Isothermal XRD experiments confirmed that the kinetics of the polymorphic transformation was different within the three samples, even if the three fats were β‐3L‐tending. At 15°C, KT transformed from liquid state to stable form without passing through α‐form, while DN and BR crystallized first into α‐from which transformed further to β′, then into stable β‐form. At 20°C, DN and BR crystallized directly from liquid to β′, which later transformed into β‐form while KT did not crystallize under the same conditions. The huge differences observed result from the differences in the TAG profiles, mainly in the StOO and StOSt content.

Interfacial materials and naphthenic acids from Brazilian crude oils: Colloidal characterization and water-in-oil emulsions

Different Brazilian crude oils form stable emulsions, although they have low asphaltenes content. The present study aimed to extract and characterize interfacial materials (IMs) from these oils to understand the factors driving this phenomenon. Polarized microscopy and small-angle X-ray scattering (SAXS) revealed that IMs can self-organize in certain conditions, and the formed aggregates could be related to the emulsification process. IMs promoted the formation of model emulsions of mineral oil and brine, but they were not enough to keep them stable. The original and residual oils from the extraction were also used to form emulsions with brine. SAXS, rheology, time-domain nuclear magnetic resonance (TD-NMR), and interfacial tension measurements allowed the comparison of these emulsions. Removal of IMs promoted self-organization of aggregates present in the oil, increasing the viscosity and stability of the emulsions. One of the crude oils had a significant content of naphthenic acids (NAs), which are known to behave as surfactants in some conditions. This fraction was also investigated, but it did not significantly affect the physicochemical properties of the emulsions in comparison with IMs. Hence, the aggregates formed by IMs combined with other components of the crude oils were probably responsible for the rheological properties affecting stability.

Diffusion kinetics of vitamin B6 released from bicontinuous and phase-inverted gelatin-agarose co-gels using blending-law modelling

In this study, gelatin and agarose were used as the phase-separated biopolymer system and vitamin B6 served as the diffusant. FTIR analysis confirmed the absence of any chemical interactions between gelatin, agarose, and vitamin B6 under the experimental conditions of this investigation. XRD analysis validated that vitamin B6 was homogenously dissolved in the composite low-solid system. Polarised light microscopy provided insights into the mixture topology and tangible evidence of the formation of bicontinuous and phase-inverted gelatin-agarose composite gels. Small-deformation dynamic oscillation was performed to establish theoretical blending law modelling, which predicted the phase volume and effective concentration of individual components (gelatin and agarose) in their respective domains. Then, a diffusion study was conducted and a novel blending law for diffusion was proposed to estimate the theoretical diffusion coefficient of vitamin B6 in the composite gel by utilizing the effective concentration of each polymer in their phase. Outcomes were compared positively to the observed diffusion coefficient from UV–vis analysis. Results demonstrate that blending-law diffusion theory can be utilised to ascertain the molecular transport of hydrophilic vitamins released from aqueous biopolymer composites.