Polarized Light Microscopy Research Articles

Comparative measurement of short-term fluoride release and inhibition of caries around restoration by ion releasing restorative materials: an in vitro study

The main objective of the current study is to compare short-term fluoride release of three ion releasing restorative materials and assess their inhibitory effect on secondary caries. Materials used in this study included, Self-adhesive hybrid composite (group A), Ion releasing flowable composite liner (group B), and alkasite restorative material (group C). Twenty-two discs were fabricated from each material for short-term fluoride release test, conducted on days 1, 7, and 14. For assessing secondary caries inhibition, sixty-six sound molar teeth were used and standardized class V cavities were prepared. Teeth were divided into three groups according to each material, followed by 800 cycles of thermocycling. Subsequently, teeth were immersed in a solution containing cariogenic bacteria for 30 days. After that, teeth were sectioned bucco-lingually and analyzed using a polarized light microscope to measure inhibition area, outer lesion depth, and extension. Data was statistically analyzed using different tests. The study results revealed a statistically significant differences in fluoride release existed among materials. Self-adhesive hybrid composite exhibited the highest fluoride release. Lesion extension and depth were statistically significantly greater next to Ion-releasing flowable composite liner. The inhibition areas next to the Self-adhesive hybrid composite were statistically significantly larger than the other two materials. In conclusion, all tested ion-releasing restorative materials displayed fluoride release and the potential to inhibit secondary caries formation. Self-adhesive hybrid composite demonstrated the highest fluoride-releasing potential and the greatest ability to inhibit secondary caries. Conversely, Ion-releasing flowable composite liner exhibited the least fluoride release with minimal secondary caries inhibition. Increasing fluoride release correlated with larger inhibition areas and reduced outer lesion depth and extension.

Collagen deposition in lung parenchyma driven by depletion of interstitial Lyve-1+ macrophages prevents cigarette smoke-induced emphysema and loss of airway function.

Collagen is essential for maintaining lung structure and function and its remodeling has been associated with respiratory diseases including chronic obstructive pulmonary disease (COPD). However, the cellular mechanisms driving collagen remodeling and the functional implications of this process in the pathophysiology of pulmonary diseases remain poorly understood. To address this question, we employed Lyve1wt/cre ; Csf1rflox/flox mice with specific depletion of Lyve-1+ macrophages and assessed the content, types and organization of collagen in lung compartments at steady state and after chronic exposure to cigarette smoke (CS). Using this mouse model, we found that the absence of this subpopulation of tissue resident macrophage led to the deposition of type I collagen fibers around the alveoli and bronchi at steady state. Further analysis by polarized light microscopy and Sircol collagen assay revealed that the collagen fibers accumulating in the lungs depleted of Lyve-1+ macrophages were thicker and crosslinked. A decrease in MMP-9 gene expression and proteolytic activity together with an increase in Col1a1, Timp-3 and Lox expression accompanied the collagen alterations. Next, we investigated the effect of the collagen remodeling on the pathophysiology of COPD and airway function in mice lacking Lyve-1+ macrophages exposed chronically to cigarette smoke (CS), a well-established animal model of COPD. We found that deposition of collagen prior CS exposure protected these mice against destruction of alveoli (emphysema), and bronchi thickening and prevented loss of airway function. Thus, we uncover that interstitial Lyve-1+ macrophages regulate the composition, amount, and architecture of collagen network in the lungs at steady state and that such collagen remodeling functionally impacts the development of COPD. This study further supports the potential of targeting collagen as promising approaches to treat respiratory diseases.

Comparative Evaluation of Deciduous and Permanent Coronal Caries Using Polarizing Light Microscopy and Scanning Electron Microscopy.

Background: Dental caries causes mineral loss and organic damage to teeth. Understanding caries and dentin pulp reactions is crucial for effective caries management strategies. There is a lack of knowledge regarding the microscopic and ultramicroscopic changes that occur during caries destruction and reactive changes. This study used polarizing and scanning electron microscopy to compare deciduous and permanent coronal caries. Materials and Methods: The study included 30 teeth, comprising 15 primary and permanent teeth, all with coronal caries. They were also compared with 10 (5 each) noncarious primary and permanent teeth. The teeth were examined using polarizing and scanning electron microscopy to study enamel and dentin destruction, reactive dentin formation, peritubular dentin destruction, and bacterial colonization. Results: Deciduous teeth had more enamel and dentin destruction for coronal caries than permanent teeth in our study. The permanent teeth had more reactive dentin formation than primary teeth. Peritubular dentine alteration was increased in deciduous teeth, and bacterial presence on dentin was higher in permanent teeth under scanning electron microscope. Conclusion: Our findings suggest that caries destruction is more prevalent in deciduous teeth, and reactive response is more effective in permanent teeth affected by caries. These findings reflect the structural durability of the mineralized tissues and prompt reactive response of the dentin pulp complex of permanent teeth compared to deciduous teeth. Our research highlights the importance of identifying and treating decay in primary teeth at an early stage.

Analytical Characterization of an Ottoman Opus Sectile Mosaic Floor from the Delta Region, Egypt

This study reports a recent analytical study of the main components of an opus sectile mosaic floor from an Ottoman bath (hammam) in the delta region of Egypt, that dates back to 1748 CE. Samples of the decorative elements of the mosaic floor including white stone, pottery mosaic pieces, black stone and setting bed mortar from the mosaic substrate were collected and analyzed. The microscopic features of the samples were examined by an optical USB digital microscope and their petrographic characteristics were evaluated by a polarized light microscope. The morphological and chemical composition of the samples were determined by a scanning electron microscope provided with an X-ray microanalyzer (SEM-EDX). The crystalline phases contained in the samples were measured by X-ray powder diffraction analysis (XRD). The results have shown that the mosaic floor was constructed using a white marble which consists of multi-sized calcite crystals with minor amounts of coesite. The pottery mosaic pieces are composed of quartz, hematite and albite. The black stone was identified as a volcanic rock of basalt which consists of andesine, anorthite and accessory quartz. A traditional lime mortar composed of quartz and calcite was used as a setting bed mortar for the mosaic pieces. Furthermore, the results showed the detection of some salt minerals which reflects the salt weathering that occurs in the site. The obtained results provided useful information on the technical structure of the studied mosaic and will be used to select appropriate materials for its restoration.

The Future of Structural Geology in the 21st Century – Moving from Mesoscale to Nanoscale Observations in Tectonically Deformed Rocks

ABSTRACT The importance of integrating field studies with various micro-and nano-scale structural geological investigations using petrographic microscope, scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) is highlighted in this paper. The author’s past studies dealing with SEM-EBSD and TEM investigations to decipher deformation mechanism of magnetite are taken as examples to support the robustness of investigating nanostructures in thin films excavated parallel to the kinematic reference frame. In addition, the author also shares a work flow involving collection of oriented field samples, followed by petrophysical investigations (e.g., porosity, permeability, P-wave velocity of oriented samples, etc.), 3D fabric analysis (e.g., AMS, X-ray micro-CT of oriented samples), 2D-microstructural analysis in oriented thin sections (petrography, SEM imaging including in-lens, EBSD, etc.) and finally nanostructural studies in oriented thin films using TEM (in that order). The importance of this integrated approach to evaluate structures at different scales and utilize the results for fundamental research as well as applications such as in the field of understanding fluid flow, mineralization, geothermal systems and radioactive waste management is discussed. Hence the paper provides an overview to the reader about some of the possibilities that exist today (21st century) in the field of structural geology.

Evaluation of Cartilage-Like Matrix Formation in a Nucleus Pulposus-Derived Cartilage Analog Scaffold.

The formation of fibrocartilage in microfracture (MFX) severely limits its long-term outlook. There is consensus in the scientific community that the placement of an appropriate scaffold in the MFX defect site can promote hyaline cartilage formation and improve therapeutic benefit. Accordingly, in this work, a novel natural biomaterial-the cartilage analog (CA)-which met criteria favorable for chondrogenesis, was evaluated invitro to determine its candidacy as a potential MFX scaffold. Human bone marrow stem cells (hBMSCs) were seeded onto the CA and cultured for 28 days in chondrogenic differentiation media. Sulfated glycosaminoglycan (sGAG) and hydroxyproline (HYP) contents were significantly higher than their non-seeded counterparts on both Days 14 and 28 (average sGAG on Day 28: 73.26 vs. 23.82 μg/mg dry wt. of tissue; average HYP on Day 28: 56.19 vs. 38.80 ± 2.53 μg/mg dry wt. of tissue). Histological assessments showed cellular infiltration and abundant sGAG formation for seeded CAs at both time points with new cartilage-like matrix filling up its laser-drilled channels. Polarized light microscopy of picrosirius red stained samples showed collagen fibrils aligning along the path of the laser-drilled channels. However, the seeded scaffolds were also found to have contracted by 20% by the end of the study with their average aggregate moduli significantly lower than non-seeded controls (10.52 vs. 21.74 kPa). Nevertheless, the CA was ultimately found to support the formation of a cartilage-like matrix, and therefore, merits consideration as a scaffold of interest for improving MFX.

Pulling Forces Dampen Torsional Fluctuations of Actin Filaments and Reduce Cooperative Cofilin Binding.

A variety of potential biological roles of mechanical forces have been proposed in the field of cell biology. In particular, mechanical forces alter the mechanical conditions within cells and their environment, exerting a strong effect on the reorganization of the actin cytoskeleton. Single-molecule imaging studies have provided evidence that an actin filament may act as a mechanosensor. An increase in the tension within actin filaments causes changes in their conformation and affinity to their regulatory proteins. However, our current understanding of the molecular mechanisms of the tension sensing and the affinity change of regulatory proteins is still incomplete. In this study, we employed fluorescence polarization microscopy and magnetic tweezers to directly quantify the torsional fluctuations of single actin filaments and cofilin binding to the filament under several distinct mechanical conditions. When an actin filament was severed by scratching the filament with a pipette tip, the amplitude of twisting/torsional fluctuations and the rate of cooperative cofilin binding increased. On the other hand, when a piconewton force was applied to single actin filaments by magnetic tweezers, the amplitude of twisting fluctuations and the rate of cooperative cofilin binding decreased. This may be involved in the molecular mechanism behind the mechanical force-dependent severing of actin filaments in cells.

A Case of Identity: A Technical Study of Victorian Wallpapers

ABSTRACT Public perception of arsenic in nineteenth-century Britain encompassed a variety of things: criminal poison, useful medicine, and a raw material for manufacturing an array of goods. During this era, Henry Carr tested wallpaper and fabric samples sent in by private individuals and manufacturers, as part of an early effort in gathering scientific data to inform and protect consumers against chronic arsenic poisoning. In 2022, eight wallpaper samples that Carr had tested were acquired by Winterthur Library. These samples were analyzed by polarized light microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray fluorescence, and Raman spectroscopy to identify the presence of arsenic. Of the eight wallpaper swatches, seven suggested trace-to-elevated levels of both arsenic and copper. Two swatches were confirmed as having the arsenical pigment emerald green (copper acetoarsenite) specifically. Research into these wallpaper samples furthers the legacy of knowledge gathering and sharing in order to protect everyday users by contributing to toxicology research in library and archives materials.

Study on the Inhibition Characteristics of Electrical Trees by the Synergistic Effect of Layered MMT and Spherical SiO2 in PE

ABSTRACTIn power equipment insulations subjected to prolonged high‐field conditions, the formation of electrical trees is a common occurrence, significantly impacting the service life and operational reliability of the equipment. In this paper, PE composites were prepared by melt blending method using layered nano‐MMT and spherical nano‐SiO2 as fillers to enhance the suppression of electrical trees. The microscopic properties of PE composites were characterized by scanning electron microscopy (SEM), polarizing microscopy (PLM), (DSC). The electrical tree of composites was conducted by the electrical tree test system. Subsequently, the synergistic inhibition of PE by nanoparticles with different morphologies was investigated. Key insights derived from the experimental findings are as follows: first, when MMT is doped with PE, due to the layered structure characteristics, the electro‐acoustic coupling effect, and the coulomb blockade effect, the complexity and complicacy of electron motion trajectory are increased, then the breakdown field strength EB of MMT/PE is increased by 5.74% compared with PE. Thus, the length of electrical trees at the retardation stage decreased by 175 μm, and their morphology changed from branch to bushy branch. Second, when layered MMT and spherical SiO2 are doped in PE simultaneously, the electron travel becomes more complex and tortuous due to the synergistic effect of nanoparticles. Compared with PE, EB of MMT/SiO2/PE is increased by 9.95%, the length entering the retardation stage of electrical trees decreases by 240 μm, and their morphology changes from branch to cluster like. Finally, microscopic and macroscopic results reveal that the combination of layered MMT and spherical SiO2 can effectively suppress the electrical tree growth in PE. These findings underscore the potential of utilizing nanostructured fillers to mitigate the development and expansion of electrical trees in polyethylene insulations, thereby enhancing the overall performance and reliability of power equipment.

Distribution and Maturity of Medial Collagen Fibers in Thoracoabdominal Post-Dissection Aortic Aneurysms: A Comparative Study of Marfan and Non-Marfan Patients.

Thoracoabdominal aortic aneurysms (TAAAs) are rare but serious conditions characterized by dilation of the aorta characterized by remodeling of the vessel wall, with changes in the elastin and collagen content. Individuals with Marfan syndrome have a genetic predisposition for elastic fiber fragmentation and elastin degradation and are prone to early aneurysm formation and progression. Our objective was to analyze the medial collagen characteristics through histological, polarized light microscopy, and electron microscopy methods across the thoracic and abdominal aorta in twenty-five patients undergoing open surgical repair, including nine with Marfan syndrome. While age at surgery differed significantly between the groups, maximum aortic diameter and aneurysm extent did not. Collagen content increased from thoracic to infrarenal segments in both cohorts, with non-Marfan patients exhibiting higher collagen percentages, notably in the infrarenal aorta (729.3 nm vs. 1068.3 nm, p = 0.02). Both groups predominantly displayed mature collagen fibers, with the suprarenal segment containing the highest proportion of less mature fibers. Electron microscopy revealed comparable collagen fibril diameters across segments irrespective of Marfan status. Our findings underscore non-uniform histological patterns in TAAAs and suggest that ECM remodeling involves mature collagen deposition, albeit with lower collagen content observed in the infrarenal aorta of Marfan patients.

Drug-Phospholipid Co-Amorphous Formulations: The Role of Preparation Methods and Phospholipid Selection.

Background/Objectives: This study aims to broaden the knowledge on co-amorphous phospholipid systems (CAPSs) by exploring the formation of CAPSs with a broader range of poorly water-soluble drugs, celecoxib (CCX), furosemide (FUR), nilotinib (NIL), and ritonavir (RIT), combined with amphiphilic phospholipids (PLs), including soybean phosphatidylcholine (SPC), hydrogenated phosphatidylcholine (HPC), and mono-acyl phosphatidylcholine (MAPC). Methods: The CAPSs were initially prepared at equimolar drug-to-phospholipid (PL) ratios by mechano-chemical activation-based, melt-based, and solvent-based preparation methods, i.e., ball milling (BM), quench cooling (QC), and solvent evaporation (SE), respectively. The solid state of the product was characterized by X-ray powder diffraction (XRPD), polarized light microscopy (PLM), and differential scanning calorimetry (DSC). The long-term physical stability of the CAPSs was investigated at room temperature under dry conditions (0% RH) and at 75% RH. The dissolution behavior of the CCX CAPS and RIT CAPS was studied. Results: Our findings indicate that SE consistently prepared CAPSs for CCX-PLs, FUR-PLs, and RIT-PLs, whereas the QC method could only form CAPSs for RIT-PLs, CCX-SPC, and CCX-MAPC. In contrast, the BM method failed to produce CAPSs, but all drugs alone could be fully amorphized. While the stability of each drug varied depending on the PLs used, the SE CAPS consistently demonstrated the highest stability by a significant margin. Initially, a 1:1 molar ratio was used for screening all systems, though the optimal molar ratio for drug stability remained uncertain. To address this, various molar ratios were investigated to determine the ratio yielding the highest amorphous drug stability. Our results indicate that all systems remained physically stable at a 1.5:1 ratio and with excess of PL. Furthermore, the CAPS formed by the SE significantly improves the dissolution behavior of CCX and RIT, whereas the PLs provide a slight precipitation inhibition for supersaturated CCX and RIT. Conclusions: These findings support the use of a 1:1 molar ratio in screening processes and suggest that CAPSs can be effectively prepared with relatively high drug loads compared to traditional drug-polymer systems. Furthermore, the study highlights the critical role of drug selection, the preparation method, and the PL type in developing stable and effective CAPSs.

Voimakan deposit of dolomite type nephrite, Middle-vitim mountain country: formation conditions

The Voimakan deposit of dolomite type nephrite has been investigated in order to clarify the features of its formation. 12 samples of nephrite and 5 samples of host rocks were studied. A binocular stereomicroscope, a gemological flashlight and a polarizing petrographic microscope were used. The contents of macro- and micro-components, the isotopic composition of oxygen were determined. Nephrite is light salad, salad, gray-salad and brown (honey). It forms separations in calcite-tremolite skarn bodies at the contact of dolomite marble and amphibolite transformed into epidote-tremolite skarn. The value of δ 18 O of nephrite is –18.5 ÷ –18.8%; calcite-tremolite skarn –17.4%; epidote-tremolite scarn –4.4, 2.6%; dolomite 26.1%. Nephrite meets the requirements for gemstone raw materials. Diopsidite with nephrite lenses and interlayers can be used for carving multicolored products or inlays. The green shade of nephrite increases with an increase in the Fe 2+ content. The brown color of nephrite is determined by Fe 3+ in the tremolite structure. The dolomite type of nephrite is confirmed by the ratio of Mg and Fe, a reduced content of Cr, Ni, Co, an increased content of F and the ratio of Sr to Ba, and the nature of the REE distribution. The distribution of REE in nephrite is determined by the composition of the initial dolomite under the influence of epidote-tremolite scarn. The source of abnormally isotopically light oxygen of nephrite is a meteoric fluid depleted in 18 O as a result of dolomite decarbonation. Granite only provides regional heating, activating the fluid. Both metasomatic and metamorphic processes were involved in the nephrite formation and transformation. The formation of nephrite is associated with the formation of calcite-tremolite and epidote-tremolite skarns. Tectonic stresses caused the crushing of rocks, facilitating the penetration of fluid, provided the formation of a nephrite cryptocrystalline tangled fibrous structure. But further regressive metamorphism led to the development of chlorite and talc, which worsened the nephrite quality.

The evaluation of Congo red staining combined with fluorescence microscopy in the diagnosis of primary cutaneous amyloidosis.

Primary cutaneous amyloidosis (PCA) is a chronic pruritic skin disease. The apple-green birefringence of Congo red-stained amyloid under a polarized light microscope (CR-PLM) remains the gold standard in the diagnosis of PCA. However, there are some limitations to this approach. In this study, eighty-two paraffin-embedded biopsy skin samples were collected from patients with a clinical diagnosis of PCA. The sections were respectively stained with hematoxylin-eosin (HE), crystal violet (CV), and Congo red (CR) and observed under a light microscope. CR-stained sections were also observed under a polarized light microscope (CR-PLM) or an ultraviolet (UV)-emitted fluorescence microscope (CR-UFM). Further, 35 cases clinically diagnosed with psoriasis, lichen planus, and prurigo nodularis were selected as the negative control group. The positive rate of amyloid protein detected by CR-UFM (81.71%) was significantly higher than that detected by CR-PLM (70.73%, p = 0.004), CR staining (56.10%, p < 0.001), CV staining (30.49%, p < 0.001), or HE staining (28.05%, p < 0.001). In the control group, 34 (97.14%) cases were negative for amyloid deposits in CR staining, CR-PLM, and CR-UFM sections. The relative number of positive dermal papillae observed by CR-UFM (0.35 ± 0.27) was much more than that observed by CR-PLM (0.15 ± 0.17, p<0.001), CR staining (0.12 ± 0.16, p < 0.001), CV staining (0.07 ± 0.12, p < 0.001), or HE staining (0.05 ± 0.12, p < 0.001). The intensity of fluorescence by CR-UFM was significantly greater than that of the appl-green birefringence by CR-PLM (p < 0.001). Moreover, the amyloid was easily distinguished from the surrounding tissues using the CR-UFM method. In conclusion, the CR-UFM method was superior to CR-PLM, CR staining, CV staining, and HE staining in diagnosing PCA.

A mouse model for the study of diet-induced changes in intestinal microbiome composition on renal calcium oxalate crystal formation.

Currently available animal models for calcium oxalate kidney stones are limited in their translational potential. Particularly with increasing interest in gut microbiota involvement in kidney stone disease, there are limited animal models which can be used. As such, we have developed a novel diet-induced hyperoxaluria murine model which addresses some of the shortcomings of other currently available models. Mice C57BL/6 mice were fed a 1.5% sodium oxalate supplemented chow for two weeks and showed no morbidity or mortality. Mice fed the sodium oxalate diet consistently had renal calcium oxalate crystal deposits as confirmed by polarized light microscopy, and energy-dispersive X-ray spectroscopy. We developed a isotope dilution high-performance liquid chromatography/mass spectrometry protocol which confirmed that our model produced both urinary and enteric hyperoxaluria. 16S ribosomal RNA sequencing of stool samples and cecal contents showed that sodium oxalate is a disruptor of the gut microbiome, and may interfere with commensal microbes in the gut microbiome. With consistent results this mouse model is superior to other models of kidney stone disease, as this model can be applied to investigate topics of oxalate absorption, transport, metabolism, excretion, crystal formation, the gut microbiome and testing of various therapeutic agents for translation to early stages of renal crystal formation in kidney stone disease.

Topographic Evaluation of the Remineralizing Potential of Biomimetic Scaffolds on Enamel White Spot Lesions: An InVitro Study.

The modern approach to managing noncavitated white spot lesions (WSLs) emphasizes noninvasive strategies and biomimetic remineralization. Biomimetic scaffolds are designed to regenerate dental tissues rather than simply repair them. This study aimed to assess lesion depth, enamel structure, and the elemental composition of artificially induced WSLs after treatment with biomimetic remineralization techniques. Ninety-six freshly extracted anterior teeth, free from caries or enamel defects and extracted due to periodontal disease, were used. White spot lesions were induced on the labial surfaces, and the samples were divided into three groups based on the remineralizing agent: Group I, treated with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), which served as the positive control; Group II, treated with self-assembling peptide P11-4 (SAP-P11-4); and Group III, treated with phosphorylated nano-chitosan (Pchi-ACP). Enamel topography was analyzed at baseline and after treatment using polarized light microscopy, micro-Raman spectroscopy, and scanning electron microscopy. Statistical analysis was conducted using one-way ANOVA, Kruskal-Wallis, and Dunn's post hoc test (p = 0.05). The Kruskal-Wallis test indicated a significant difference in remineralization potential among the groups. Pchi-ACP showed the greatest reduction in lesion depth (62.65%), demonstrating significant subsurface enamel remineralization. This group also exhibited a smooth, regular enamel surface with shallow linear depressions. Elemental analysis confirmed successful calcium phosphate precipitation in Pchi-ACP, indicating a trend toward enamel regeneration. Pchi-ACP represents a promising biomimetic and minimally invasive approach for treating early WSLs, signifying a transition toward regenerative dentistry. (SAP-P11-4), while effective, was less successful than phosphorylated nano-chitosan but outperformed (CPP-ACP). Pchi-ACP demonstrates significant potential for minimally invasive treatment of early noncavitated carious lesions. By preserving natural tooth structure, this approach could greatly enhance oral health outcomes in the long term.

Label-Free Liquid Crystal Aptamer Sensors Based on Single-Stranded Nucleic Acid π-Structures for Detecting cTnI.

Cardiac troponin I (cTnI) is a highly sensitive and important serological marker for clinical diagnosis of myocardial injury. Its rapid detection is crucial for the early diagnosis of cardiovascular diseases such as acute myocardial infarction. In this study, based on nucleic acid molecular hybridization and aptamer-specific binding to target molecules, a label-free liquid crystal aptamer sensor based on single-stranded nucleic acid π-structures was developed and applied for the quantitative detection of cTnI. The CP1 and CP2 oligonucleotide chains, complementary to the bases at both ends of the aptamer, are covalently bonded to the sensor substrate via APTES and GA-mediated molecules. The aptamer forms a π-structure with CP1 and CP2 through nucleic acid hybridization, serving as a target molecule capture probe. When cTnI is present in the system, cTnI and the complementary oligonucleotide chains competitively bind with the aptamer, causing the breakdown of the π-structure within the sensor. This reinstates the long-range ordered alignment of the 5CB liquid crystal molecules within the sensor, enabling quantitative measurement of cTnI through variations in optical images. Experimental results show that within the range of 0.01 to 25 ng/mL for cTnI concentration, there is a linear correlation between the brightness area coverage (Br) in the polarized light microscopy images of the sensor and the logarithm of the cTnI concentration, with a correlation coefficient (r). The detection limit is 5.16 pg/mL. This method is label-free, simple to operate, and low-cost, with good specificity and a low detection limit, achieving cTnI detection in serum samples.

Polarised light scanner for digital pathology.

Digital pathology is rapidly transforming diagnostic pathology by allowing remote work and integration of artificial intelligence solutions. Nevertheless, certain technical issues remain to be resolved. Notably, digital images captured by conventional scanners cannot be subjected to polarised light analysis [1]. We have therefore studied if images obtained using the Glissando POL Brightfield and Polarised Light Scanner are comparable to those obtained using conventional polarised light microscopy. Hematoxylin and eosin stained sections from 75 cases, including cases of amyloidosis, periprosthetic membranes, foreign body granulomas, gout, pseudogout, and breast tissues with calcium oxalate crystals were examined using both, a polarised light microscope and the Glissando POL scanner. Representative digital images were acquired for comparison. We here show that in all settings, the images obtained by conventional polarised light microscopy and using the Glissando POL scanner were comparable. We conclude that the Glissando POL scanner can be safely integrated into a digital pathology workflow.

Aptamer's Structure Optimization for Better Diagnosis and Treatment of Glial Tumors.

Background: Oncological diseases are a major focus in medicine, with millions diagnosed each year, leading researchers to seek new diagnostic and treatment methods. One promising avenue is the development of targeted therapies and rapid diagnostic tests using recognition molecules. The pharmaceutical industry is increasingly exploring nucleic acid-based therapeutics. However, producing long oligonucleotides, especially aptamers, poses significant production challenges. Objectives: This study aims to demonstrate the efficacy of using molecular modeling, supported by experimental procedures, for altering aptamer nucleotide sequences while maintaining their binding capabilities. The focus is on reducing production costs and enhancing binding dynamics by removing nonfunctional regions and minimizing nonspecific binding. Methods: A molecular modeling approach was employed to elucidate the structure of a DNA aptamer, Gli-55, facilitating the truncation of nonessential regions in the Gli-55 aptamer, which selectively binds to glioblastoma (GBM). This process aimed to produce a truncated aptamer, Gli-35, capable of forming similar structural elements to the original sequence with reduced nonspecific binding. The efficiency of the truncation was proved by flow cytometry, fluorescence polarization (FP), and confocal microscopy. Results: The molecular design indicated that the new truncated Gli-35 aptamer retained the structural integrity of Gli-55. In vitro studies showed that Gli-35 had a binding affinity comparable to the initial long aptamer while the selectivity increased. Gli-35 internalized inside the cell faster than Gli-55 and crossed the blood-brain barrier (BBB), as demonstrated in an in vitro model. Conclusions: The success of this truncation approach suggests its potential applicability in scenarios where molecular target information is limited. The study highlights a strategic and resource-efficient methodology for aptamer development. By employing molecular modeling and truncation, researchers can reduce production costs and avoid trial and error in sequence selection. This approach is promising for enhancing the efficiency of therapeutic agent development, particularly in cases lacking detailed molecular target insights.

Preparation and in-vitro characterization of triamcinolone acetonide-loaded lipid liquid crystal nanocarriers for ocular delivery

Purpose: This study aimed to develop sustained-release Triamcinolone acetonide (TA) formulations using lipid liquid crystals (LLC) for ocular drug delivery and to characterize the designed formulations. Method: Eighteen dispersed LLC formulations were prepared through a top-down approach, incorporating varying concentrations of TA and different proportions of glyceryl monooleate, deionized water, and Pluronic F127. An additional formulation comprising TA: HPβCD complex was also developed to investigate the influence of hydroxypropyl beta-cyclodextrin (HPβCD) on the properties of the formulations. The formulations were evaluated for their rheological properties in room temperature using a rheometer, syringeability by passing them through a 27G needle, size measurements via dynamic light scattering, and morphology through polarized light microscopy (PLM). Furthermore, the prepared formulations were injected into a dialysis tube and placed in a phosphate buffer at pH 7.4 and 37°C for in vitro release evaluation. Samples were taken at predetermined intervals and stored in a refrigerator until HPLC analysis. The percentage of Encapsulation efficacy and drug loading were evaluated using an indirect method. A reversed-phase HPLC method was employed to quantify the drug concentrations in the samples. Results: All selected formulations demonstrated acceptable parameters, including particle size (less than 200 nm), polydispersity index ranging from 0.202 to 0.355, and zeta potential values between -14.3 and -32.8 mV. Additionally, the formulations showed good syringeability and achieved 100% drug release within 48 hours (except for the formulation containing HPβCD). PLM analysis revealed the presence of hexosomes and cubosomes, indicating that an increase in hexosomes contributed to a more uniform drug release from the formulations. Conclusion: Overall, the study findings suggest that liquid crystalline carriers can be a promising formulation for sustained ocular drug delivery of TA.

Enhancing geothermal petrography with convolutional neural networks

The qualitative assessment of a geothermal reservoir using petrography is often conducted during drilling to assess the permeability, porosity, and mineral geothermometry of the reservoir rocks especially when little is known about the subsurface during the exploration stage. The petrographic analysis includes visually estimating pore and vein fractions, identifying rock textures, describing the degree of alteration, recognizing the hydrothermal alteration minerals and indicated temperature, and noting the presence of shearing and various porosity types. This traditional method of visual estimation and assessment is prone to errors when averaging fields of view and can be labor-intensive, especially during time-sensitive drilling operations when a geologist must analyze hundreds of thin sections per well under a polarizing light microscope. In this study, indicated porosity levels were assigned to 103 geothermal core thin sections based on the grouping of the rock parameters as observed under a polarizing light microscope. To enhance the traditional visual assessment in petrography, this study trained and validated convolutional neural networks (CNNs) in the automatic rating of porosity based on these parameters and in the detection of epidote, a key production marker in high-temperature magmatic-intrusive geothermal systems. Photomicrographs of the geothermal well core thin sections were utilized as input data for training and validating the ResNet, AlexNet, and VGGNet architectures. The three CNN architectures achieved porosity classification precision ranging from 0.74 to 0.84, and epidote detection precision between 0.90 and 1.0 in plane-polarized light (PPL) photomicrographs. The results demonstrate that CNNs can significantly augment traditional petrography in evaluating geothermal well samples.