Dark Staining Research Articles

Color Stability of Different Restorative Approaches for the Masking of Silver Diamine Fluoride after Thermal Aging.

The present study aims to evaluate the color stability of different masking modalities of silver diamine fluoride (SDF) on extracted carious teeth after thermal aging. One hundred and eight recently extracted carious permanent teeth were used. All sample teeth had SDF applied over the carious lesion. The teeth were then divided into six groups: group A (SDF, potassium iodide (KI), and packable composite resin), group B (SDF, flowable, and packable composite resin), group C (SDF, KI, resin-modified glass ionomer (RMGI), and packable composite resin), group D (SDF, KI, and RMGI), group E (SDF, hybrid glass ionomer (HGI), packable composite resin), and group F (SDF and RMGI). VITA Easyshade was used to evaluate color stability. Initial masking of the dark staining was improved in groups in curing light groups (groups D and F). Groups restored with RMGI demonstrated the greatest color changes after aging. The groups that showed the greatest color stability of the materials after 5 years of aging were groups A, B, and E. Highest color change was observed during the first clinical year for all groups. KI is effective at reducing SDF staining. Composite (CMP) provides a long-term color-stable restoration. Thermocycling had the greatest effect on HGI restorations. One of restorative dentistry's most important clinical parameters is the color stability of tooth-colored dental restorations. Choosing a suitable restorative material is essential to overcome SDF's staining effects. Applying KI and composite resin restoration was the most effective, long-term color-stable restorative material for masking the SDF staining. Ozuna J, Nguyen C, Abubakr NH. Color Stability of Different Restorative Approaches for the Masking of Silver Diamine Fluoride after Thermal Aging. Int J Clin Pediatr Dent 2024;17(9):987-992.

The Parental Concern and Acceptance of Silver Diamine Fluoride Treatment in Preschool Children: A Cross Sectional Study.

Silver diamine fluoride (SDF) is a minimally invasive treatment with proven efficacy for managing early childhood caries. However, the dark staining associated with SDF treatment remains a major concern that affects parental acceptance. This study examines the level of parental acceptance of SDF treatment for preschool children in Laos and explores associated factors such as parental anxiety, previous dental experience, and demographic data. A cross-sectional survey was conducted with 324 parents of children aged 2-5 years enrolled in preschools in Vientiane Capital, Laos. Participants provided demographic information, details on their children's dental history, and their own dental anxiety levels. Following a video demonstration of the effectiveness and application of SDF, parents completed a survey assessing their acceptance of and concerns about SDF using a 5-point Likert scale. Parental dental anxiety was measured with the modified dental anxiety scale. Data were analyzed using chi-square tests, independent t tests, and multiple logistic regression (P ≤ 0.05). Eighty percent of the parents accepted SDF treatment for their children. Those highly concerned about SDF staining were significantly less likely to accept it as a treatment option (P < 0.01). Increased acceptance correlated with reduced concern about staining (95% confidence interval = 15.57-1095.88). Additionally, 84.9% of parents reported some level of dental anxiety, with older parents showing higher acceptance of SDF. Parents were highly receptive of the SDF treatment for their children's primary dentition. Parents who were older tended to be less concerned about the staining, and those who had a high level of dental anxiety were more likely to accept SDF treatment.

The taphonomic effects of long-term burial in the South African Highveld

Taphonomy studies the environmental effects on remains from the time of deposition to the time of recovery and has been integrated into the field of forensic anthropology. The changes to skeletal remains are dependent on the method of disposal and the surrounding environment. This study focused on buried remains where the type and chemical composition of the soil and the microorganisms present need to be considered. The aim was to investigate the type, frequency, and correlations of the taphonomic alterations of buried domestic pigs. Six taphonomic alterations were observed which included depositional staining, adipocere formation, bone weathering, acidic soil corrosion, and plant, and animal activity. Depositional staining, weathering and plant activity were the most common alterations followed by adipocere which was present on 92.3% of the remains. The bones were mostly stained dark brown and brown; however, the trunk region was the only region to present with black staining. The right sides were darker than the left due to the body positioning as most pigs were placed on their right sides and thus were in direct contact with the cadaver decomposition island. Additionally, the right sides presented with more adipocere as well as increased plant activity suggesting that the soil retained water. Darker stains were correlated with a more complete skeleton as adipocere provides some protection. The study confirms that there are various complicated relationships between different taphonomic alterations. A good understanding of them is needed in forensic anthropology to assist in reconstructing the events that occur after death.

Clinicopathological Characteristics of 11 Cases with Spiradenoma: A Rare Adnexal Tumor

Objective: To explore the clinicopathological characteristics of spiradenoma (SA), and make exact diagnosis and differential diagnosis of this disease. Methods: The clinical and pathological data of 11 patients with spiradenoma in the First Affiliated Hospital of Jinan University from 2013 to 2022 were retrospectively analyzed, and combined with the review of literatures. Results: Among the 11 patients with spiroadenomas, 6 cases were male and 5 were female; the age ranged from 19 to 70 years old, with an average age of 41 years; Spiradenomas are more common in the trunk and limbs. At low-power microscope, the tumor mass with capsule in the dermis. Under a high-power microscope, the tumor is usually composed of two types of cells, which are the marginal small basaloid cells with dark staining and central larger cells with a pale and acidophilic nucleus. Other morphological structures included 2 cases of cystic solid and cylindroma respectively. Immunohistochemistry showed that epithelial and myoepithelial differentiation. Conclusion: Spiradenoma often occurs subcutaneously and requires histopathological diagnosis to avoid misdiagnosis. Its biological behavior is benign and its prognosis is good. But malignant transformation should be considered in some case with long course or relapses. SA is rare in clinical and is prone to misdiagnosis or missed diagnosis. This study summarizes the clinilcopathological characteristics of SA, providing reference for future clinical diagnosis and treatment.

CytoLyt fixation impedes insulinoma-associated protein 1 (INSM1) immunoreactivity compared to formalin fixation

Insulinoma-associated protein 1 (INSM1) is an immunohistochemical marker commonly used to confirm cytomorphological concordant neuroendocrine tumors/carcinomas (NETs/NECs), demonstrating high utility in small samples. Previous reports have suggested comparable INSM1 staining in CytoLyt-fixed cell blocks and formalin-fixed surgical pathology specimens. This study aimed to assess INSM1 immunoreactivity using both fixation methods and investigate potential factors contributing to its variable expression. A retrospective query was performed (03/31/21-05/31/22) for NET/NEC cases that had both formalin- and CytoLyt-fixed cell blocks. We collected clinical data and reporting of immunostains for each case. INSM1 staining was evaluated in both fixation methods, and reported as positive, negative, or equivocal. Equivocal INSM1 staining was further scored as a percentage of 1%-100% and intensity of weak (faint staining), moderate (darker staining), and strong (dense staining). Our search identified 20 cases from diverse body sites, including mediastinal lymph nodes (40%), pancreas (35%), lung (20%), and porta hepatis lymph nodes (5%). All cases exhibited a widespread positivity (over 90%) in formalin-fixed cell blocks. In contrast, CytoLyt fixed cells showed a negative stain in 65% of cases and 30% exhibited an equivocal positivity. While INSM1 is previously reported as a sensitive (75%-100%) and specific (82.7%-100%) marker for NET/NECs, our study found a reduced immunohistochemical staining in CytoLyt-fixed cell blocks. Consequently, false negative INSM1 immunohistochemical results in CytoLyt-fixed cell block material may pose a pitfall in the diagnosis of NET/NEC.

Rock - soil transition during weathering of rhyolite

Concentric layers of weathered materials around core-stones show the rhyolite to experience sequential, but gradational, changes in visible features, textures and mineralogy as it transforms from ‘rock’ into ‘soil’. The changes start with the opening-up of grain boundaries and micro-cracks (stage 1) followed by their dark brown staining (stage 2) and the subsequent alteration (to sericite and clay minerals) of plagioclase feldspar groundmass grains and phenocrysts (stage 3). Biotite flakes are then bleached and altered (to chlorite and clay minerals) (stage 4) before there starts alteration (to sericite and clay minerals) of groundmass alkali feldspar grains (stage 5) and finally alteration of alkali feldspar phenocrysts (stage 6). Quartz grains are not altered during these stages of weathering but disaggregate and reduce in size due to continual opening-up of grain boundaries and micro-cracks. Increasing stages of weathering are marked by decreasing dry unit weights, dry densities and uniaxial compressive strengths, but increasing apparent porosities. The transition between ‘rock’ and ‘soil’ occurs during weathering stage 6 when all plagioclase groundmass grains and phenocrysts have been altered as have been all alkali feldspar groundmass grains and most phenocrysts. Stage 6 is marked by large apparent porosities (&gt;14%) but low values of dry unit weight (&lt;21.90 kN/m3) and dry density (&lt;2,232 kg/m3).

AN ALTERNATIVE TO FIXATING HISTOLOGY SPECIMENS BY USING HOTPLATE AT 60°C FOR 10 MINUTES

AN ALTERNATIVE TO FIXATING HISTOLOGY SPECIMENS BY USING HOTPLATE AT 60°C FOR 10 MINUTES

Enhancing endometrial pathology detection: chromohysteroscopy vs. conventional hysteroscopy in infertility evaluation

BackgroundEndometrial pathology is a recognized contributor to infertility and recurrent implantation failure, but its detection during hysteroscopy, particularly in the absence of visible lesions, is challenging. Chromohysteroscopy, involving the use of methylene blue dye, has shown promise in improving diagnostic accuracy.MethodsThis interventional cross-sectional study compared the diagnostic accuracy of chromohysteroscopy and conventional hysteroscopy, using histopathology as the gold standard. A total of 100 consenting infertility patients were included, in a sequential step, hysteroscopy followed by chromohysteroscopy using methylene blue dye was performed to enhance the detection of subtle endometrial pathologies.ResultsAmong the 100 women who underwent diagnostic hysteroscopy, 76 exhibited normal findings, while 24 had abnormal findings. During chromohysteroscopy, 62 cases displayed a light staining pattern, and 38 cases exhibited dark staining. Histopathological analysis of biopsy tissue from the dark-stained areas revealed endometrial pathology in 84.2% (32/38) and normal endometrium in 15.8% (6/38) cases. In contrast, biopsies from the light-stained areas indicated abnormal endometrium in only 3.23% (2/62) cases, with the remaining 96.77% having a normal histology. Chromohysteroscopy demonstrated a significantly higher diagnostic accuracy (92%) for endometrial pathology compared to conventional hysteroscopy (58%). Notably, chromohysteroscopy’s sensitivity was 94.12%, and its specificity was 90.9%. The staining patterns observed during chromohysteroscopy correlated well with histological findings, highlighting its effectiveness in identifying structurally damaged endometrium.ConclusionChromohysteroscopy emerges as a valuable diagnostic tool for assessing endometrial pathology, especially in infertility cases. This technique offers superior accuracy compared to conventional hysteroscopy, providing clinicians with a more precise means of diagnosis and potential targeted treatments.

Benefits of topical indigo naturalis nanofibrous patch on psoriatic skin: A transdermal strategy for botanicals.

Indigo naturalis (IN) has been extensively used as a topical treatment for psoriasis. However, clinical applications of IN in ointment were hampered by its limited transdermal efficiency and dark stains. To address the aforementioned issues, nanopatches carrying IN were fabricated using poly(ε-caprolactone, PCL)/poly(ethylene oxide, PEO) and topically applied to psoriasiform skin. The ideal ratio of 5% PCL/PEO was established to be 80:20 (w/w), and 15% IN as payload was confirmed. Investigations on the three principal active components of IN release indicated that indirubin and tryptanthrin were released in bursts, while indigo was released in a limited and controlled manner. Further biological analyses confirmed a favorable biocompatibility of amphiphilic IN-PCL/PEO, which coincided with the intended therapeutic outcomes as measured by severity index scoring and pathological evaluations in vivo. The advantages of IN as nanopatches over ointment could be due to improved transdermal distribution of indirubin and tryptanthrin, resulting in effective management of epidermal hyperplasia and blood vessel remodeling. Meanwhile, due to the lower preservation of epidermal indigo, IN-PCL/PEO nanopatches caused no skin coloration. Similarly, during a 4-week topical treatment of IN-PCL/PEO nanopatches, the safety and anti-psoriatic benefits were obtained in an initial human test. The conversion of IN from topical cream to electrospun nanofibers opens up new avenues for bench-to-bedside translation of this herbal therapy and provides mechanistic insight into IN's roles in the management of psoriasis.

Peroneal Tendon Disorders: Cellular Profiles and Gene Expression

Category: Basic Sciences/Biologics; Ankle Introduction/Purpose: Peroneal tendon disease (PTD) represents a spectrum of pathologies. Current literature focuses on pathoanatomy, but not the microenvironment of the peroneal complex on a histopathological cellular level. This information is crucial to understanding disease progression and future development of therapeutic strategies. This study aims to define the histological microenvironment and transcriptome of tenosynovium in patients with various disease stages. We further propose a classification system for PTD: (Type 0) Normal tenosynovium; (Type 1) Inflammatory tenosynovium with normal appearing tendons; (Type 2) inflammatory or degenerative tenosynovium with tendinosis or split tear involving less than 50% of tendon substance; (Type 3) Inflammatory or degenerative tenosynovium with tendinosis or split tear involving greater than 50% of tendon substance; (Type 4) Complete or near complete degenerative rupture. Methods: Tenosynovium was sampled from patients, classified for PTD, and then processed for RNA sequencing (RNA-seq; n = 3) and histology (n = 7). RNA-seq was performed using the Illumina NovaSeq6000 platform. Differential expression was determined using the R edgeR (3.22.5) package after adjusting via a scaling normalization factor and correcting P-values via the Benjamini Hochberg method. Tenosynovium samples were processed for hematoxylin and eosin (H&amp;E) staining and evaluated using machine learning to classify cell types. Briefly, QuPath software was used to load images of H&amp;E section4-means, fuzzy c-means and gaussian mixture. Cells were assigned to clusters and then quantified and visualized with density plots in QuPath. Results: UMAP with k-means clustering was the best data reduction and clustering technique. Total cellular density increased with type 3 and 4 PTD compared to type 1; cluster 3 cells were the most increased with types 3 and 4 compared to type 1 (Figure 1A). Cluster 3 cells appear in vascular structures and are elongated/oval with dark nuclear staining (Figure 1B). In type 3 and 4, cluster 3 cells appear in and around vascular structures and at the surface lining in type 4. RNA-seq identified 13 genes differentially expressed (p &lt; 0.05; Figure 1B). Significant gene ontology terms include muscle contraction, myofibril assembly, and actin myosin filament sliding (Figure 1C). Significant reactome pathways include muscle contraction, fatty acyl-CoA biosynthesis, and activation of gene expression by SREBF. Conclusion: In this study, RNA-seq and machine learning cell classification in H&amp;E staining yield findings that represent the cellular and molecular disease signature in PTD. Histological analysis demonstrated that in more severe classes of PTD (types 3-4), cell morphologies found in vascular structures and surface lining were increased and suggestive of fibroblasts/ myofibroblasts and smooth muscle cells. RNA-seq demonstrated an increased expression of genes, with muscle contraction and myofibril activity representing significant signatures. Overall, our study demonstrates potentially increased cell and gene pathways consistent with smooth muscle activity and fibrosis. These pathways present targets for better classifying and treating PTD pathology.

Easy, fast, cheap, informative, and pretty – staining of plant sections with Mayer’s mucicarmine and Lugol’s reagent

Abstract A novel combination of widely used commercial histochemical reagents, Mayer’s mucicarmine and Lugol’s reagent, was applied to survey anatomical analysis of various plant organs: Euphorbia splendens stem, Hibiscus rosa-sinensis petiole, Homalocladium platycladum stem base, Phalaenopsis sp. aerial root, Rhipsalis sp. stem, Schoenoplectus lacustris stem base, and Urtica dioica stem primary structure. The staining resulted in red coloration of non-lignified cell walls and mucilage, yellow coloration of lignified cell walls and protein-rich components of the protoplasts, and dark staining of starch. The method was found to be cheap, easy, fast, and informative, and thus widely applicable in both teaching and research.

Correlating peptidylglycine alpha-amidating monooxygenase (PAM) expression with clinicopathologic variables in gastrointestinal (GI) neuroendocrine tumors (NETs).

e16243 Background: Peptidylglycine alpha-amidating monooxygenase (PAM) is a hypoxia-responsive protein which is responsible for peptide alpha-amidation, important in neuroendocrine hormone maturation. A prior study of well-differentiated neuroendocrine tumors of multiple sites, both GI and non-GI, has shown that PAM expression by immunohistochemistry correlates with important clinical and pathologic parameters. We assessed PAM expression by immunohistochemistry using two separate scoring systems in patients with well-differentiated neuroendocrine tumors (NETs) exclusively of the GI tract and assessed its correlation with clinical and pathologic variables. Methods: A tissue microarray was constructed from 58 patients with NETs of the GI tract. Two separate scoring systems were used, the immunoreactive score (IRS) and one as described by Horton et al (2020). The IRS score was derived by scoring for intensity (range 0-3) and percent of cells staining (range 0-4), multiplying these to give an overall IRS between 0 and 12. These results were dichotomized into 0-1 (negative) and 2-12 (positive). The score as described by Horton et al is a 4-tiered system: 0, no staining; 1, very faint and scarce staining; 2, staining easily visible in &gt; 50% of tissue; 3, moderately dark and intense staining across 50% of tissue; 4, very intense dark staining across &gt; 50% of tissue. These were then divided into negative (0), low (1) and high (2-4) scores. Clinical and pathologic variables were collected from the clinical records and correlated with PAM staining. Results: Patients had NETs involving the stomach (n = 1), duodenum (n = 3), ileum (n = 18), small bowel (n = 12), cecum (n = 2), and pancreas (n = 13). Twenty-one patients (36.2%) had 1 metastatic site, 12 patients (20.7%) had &gt; = 2 metastatic sites and 25 patients (43.1%) lacked metastases. IRS and Horton scores were compared and were correlated (p = 0.007). By IRS, 9 patients (31%) had negative staining, and 20 patients (69%) had positive PAM staining. PAM staining did not correlate with functional status of the tumor (p = 1), synchronicity of disease (p = 1), number of metastatic sites (p = 0.69), Octreotide receptor positivity (p = 0.72) or blood chromogranin A (p = 0.58) and urine 5 HIAA levels (p = 0.52). PAM scoring also did not correlate with Ki-67 of primary tumors (p = 0.57). Conclusions: In our GI NET cohort, PAM staining did not correlate with any of the assessed clinical variables or with Ki-67 of primary tumors. A previous study of NETs involving more body sites found that PAM staining did inversely correlate with Ki-67 scoring. This difference may be due to our assessment of solely gastrointestinal NETs.

Nut factors associated with navel orangeworm, Amyelois transitella (Lepidoptera: Pyralidae) damage to pistachio (Pistacia vera) in California (2007-2017) and implication for control.

Amyelois transitella is the primary pest of pistachios in California. The first A. transitella outbreak of the twenty-first century occurred in 2007 and a total of five outbreaks occurred between 2007 and 2017 (total insect damage >1%). This study used processor information to identify the nut factors associated with the outbreaks. Processor grade sheets were used to explore the relationship between the variables time of harvest, percent nut split, percent nut dark staining, percent nut shell damage, and percent adhering hull for Low Damage (82,537 loads) and High Damage years, (92,307 loads). Total insect damage (±SD) for the Low Damage years averaged 0.005 ± 0.01 and in High Damage years was three times higher, 0.015 ± 0.02. In Low Damage years the strongest correlation was between total insect damage and two variables, percent adhering hull and dark stain (0.25, 0.23) while in High Damage years the correlation between total insect damage and percent dark stain was the highest (0.32) followed by percent adhering hull (0.19). The linkage of these nut factors to insect damage suggests that outbreak prevention depends on early identification of premature hull split/breakdown in addition to the traditional emphasis on treating the standing population of A. transitella.

Imaging and micro-invasive analyses of black stains on the passepartout of Codex Atlanticus Folio 843 by Leonardo da Vinci

This paper accounts for the diagnostic campaign aimed at understanding the phenomenon of black stains appeared on the passepartout close to the margins of Folio 843 of Leonardo da Vinci’s Codex Atlanticus. Previous studies excluded microbiological deterioration processes. The study is based on a multi-analytical approach, including non-invasive imaging measurements of the folio, micro-imaging and synchrotron spectroscopy investigations of passepartout fragments at different magnifications and spectral ranges. Photoluminescence hyperspectral and lifetime imaging highlighted that black stains are not composed of fluorescent materials. μATR-FTIR imaging of fragments from the passepartout revealed the presence of a mixture of starch and PVAc glues localized only in the stained areas close to the margin of the folio. FE-SEM observations showed that the dark stains are localized inside cavities formed among cellulose fibers, where an accumulation of inorganic roundish particles (∅100–200 nm in diameter size), composed of Hg and S, was detected. Finally, by employing synchrotron μXRF, μXANES and HR-XRD analyses it was possible to identify these particles as metacinnabar (β-HgS). Further research is needed to assess the chemical process leading to the metacinnabar formation in the controlled conservation condition of Leonardo’s Codex.

Metallography of Fractured Aluminium Alloys for the Transmission System ́s Elements

The metallography was used for evaluation of fractured elements from different aluminium alloys´ elements applied in Czech transmission system. Although the fractured elements were produced from different aluminium alloys (hypereutectic Al-18%Si, AlSi10Mg, Al0,7MgSi) the main reason of fractures was very similar for all of them – the low quality of casting, inhomogeneous structure and composition of matrix. These analyses were performed on fracture surfaces and on reference matrix. Typical defect evident on fractured areas was dark stains. In some cases, the quartz concentration was ca twice into comparison with standards composition and reference matrix.

Fuzzy K-Nearest Neighbor Based Dental Fluorosis Classification Using Multi-Prototype Unsupervised Possibilistic Fuzzy Clustering via Cuckoo Search Algorithm.

Dental fluorosis in children is a prevalent disease in many regions of the world. One of its root causes is excessive exposure to high concentrations of fluoride in contaminated drinking water during tooth formation. Typically, the disease causes undesirable chalky white or even dark brown stains on the tooth enamel. To help dentists screen the severity of fluorosis, this paper proposes an automatic image-based dental fluorosis segmentation and classification system. Six features from red, green, and blue (RGB) and hue, saturation, and intensity (HIS) color spaces are clustered using unsupervised possibilistic fuzzy clustering (UPFC) into five categories: white, yellow, opaque, brown, and background. The fuzzy k-nearest neighbor method is used for feature classification, and the number of clusters is optimized using the cuckoo search algorithm. The resulting multi-prototypes are further utilized to create a binary mask of teeth and used to segment the tooth region into three groups: white-yellow, opaque, and brown pixels. Finally, a fluorosis classification rule is created based on the proportions of opaque and brown pixels to classify fluorosis into four classes: Normal, Stage 1, Stage 2, and Stage 3. The experimental results on 128 blind test images showed that the average pixel accuracy of the segmented binary tooth mask was 92.24% over the four fluorosis classes, and the average pixel accuracy of segmented teeth into white-yellow, opaque, and brown pixels was 79.46%. The proposed method correctly classified four classes of fluorosis in 86 images from a total of 128 blind test images. When compared with a previous work, this result also indicates 10 out of 15 correct classifications on the blind test images, which is equivalent to a 13.33% improvement over the previous work.

Histochemical study of the hepatic metacestodes in sheep infected with hydatidosis

This study aimed at detecting the liver histopathological changes of hydatid cysts sheep infestation. Seventeen sheep liver's samples, infested with hydatid cysts, were collected from the local butchers. The specimens sectioned, processed, and stained with hematoxylin and eosin and some special stains such as Gomori's aldehyde fuschin, Van Gieson, Toluidine blue, Alcian blue, Periodic Acid Schiff (PAS) and Mansso's trichrome. The results of haematoxylin and eosin stain of infected groups revealed the presence of the laminated membrane of hydatid cyst in different spots of hepatic tissue encircled by infiltration of inflammatory cells, an increase in fibrous tissue and severe necrotic hepatic tissue. The special stains as in Gomori's aldehyde fuschin revealed the protoscolex in green colour and elastic fibres of connective tissue surrounding hydatid cyst with its laminated membrane in purple colour. Van Gieson stain showed dark brown-purple colour of the elastic fibres reduplication of connective tissue surrounding hydatid cyst, while Toluidine blue stain sections revealed the dark blue stain of acidic components of hydatid cyst laminated membrane and necrotic hepatocytes. Alcian blue stain revealed the blue colour reactivity of the proteoglycans of the connective tissue surrounding hydatid cyst. PAS reaction stain revealed the magenta colour reaction of the intact hepatocytes in the control group comparing with depletion of magenta colour in necrotic hepatocytes surrounding hydatid cyst. Masson's trichrome stain revealed increased collagen fibres of the connective tissue. At the conclusion, it’s evident that infection with hydatid cysts causes a variety of histopathological alterations that appeared through several tissue stains.

Tentacular nature of the ‘column’ of the Cambrian diploblastic Xianguangia sinica

Unveiling the body architectures of Cambrian problematic fossils would provide novel insights into the radiation of metazoan body plans during the ‘Cambrian Explosion’ and the ancestral traits of major living animal clades. Xianguangia sinica, from the celebrated Chengjiang biota (∼518 Ma), is a typical Cambrian problematicum with disputable body architecture, particularly about its ‘column’ part. The contradictory interpretations of the ‘column’ of X. sinica have led to at least three hypotheses regarding its affinity in the diploblastic clade. Here we depict the detailed anatomy of the ‘column’ based on new, exquisitely preserved material. The ‘column’ of X. sinica is formed by 18 longsword-shaped tentacle-sheath complexes that can either close or be in a flowering state. There is no partitioned cavity internally when the ‘column’ is closed, invalidating the homology with the true column of living sea anemones. Each tentacle tapers distally and includes a distal flexible portion at about one-fourth the length of the tentacle. The proximal portion is stiff, bearing a set of paired dark stains, and is enveloped by a single outer sheath. Pinnules carrying a row of large cilia are fringed on both sides along the whole length of the tentacles. The body plan of X. sinica is accordingly revised as consisting of a calyx and 18 unique tentacle-sheath complexes that radially surround the mouth. Our result corroborates previous observations that suggest a close relationship between Xianguangia, Daihua and Dinomischus, all of which are here formally assigned to the family Dinomischidae, a monophyletic clade recovered in our phylogenetic analyses. Xianguangia sinica likely employs cilia-bearing pinnate tentacles for sieving particle matter down to 21 µm, indicating that its nutrition source is suspended micro-planktonic organisms or other organic matter in the bottom water.

A morphological study on sinus and atrioventricular nodes in saanen goats*

In mammals, the sinus node and atrioventricular node are defined as the heart's specific stimulus and conduction systems. The electrical stimulation that starts in the sinus node continues with the atrioventricular node, and the rhythmic stimulation occurs in this way. There are differences in the sinus and atrioventricular nodes' location, size, and cell structures between species. In this study, which was carried out to determine the morphological structures and locations of the sinus and atrioventricular nodes in Saanen goat hearts, nine hearts from healthy goats were used. After performing the routine tissue follow-up procedure for histological examinations, 5 μm-thick serial sections taken from paraffin-blocked samples were stained with Crossman Trichrome and Periodic Acid Schiff (PAS) and photographed. It was determined that the sinus node was in a subepicardial position near where the cranial vena cava opens up to the right atrium. The sinus node, with an average length of 8-10 mm was crescent-shaped. The atrioventricular node was located in the subendocardium layer in the right half of the interatrial and the interventricular septum, where the coronary sinus opened into the right atrium. An atrioventricular node with an average length of 4.5-5 mm was observed to be roughly oval. Two types of cells were identified in both nodes: cells with small, rounded with empty cytoplasm and rather large nuclei, and cells with thin, elongated structures and darker staining.

Biomimetic Whitening Effect of Polyphosphate-Bleaching Agents on Dental Enamel.

This in vitro study investigated the extrinsic tooth-whitening effect of bleaching products containing polyphosphates on the dental enamel surface compared to 10% carbamide peroxide (CP). Eighty human molars were randomly allocated into four whitening-products groups. Group A (control) was treated with 10% CP (Opalescence). The other groups with non-CP over-the-counter (OTC) products were group B = polyphosphates (iWhiteWhitening-Kit); group C = polyphosphates+fluoride (iWhite-toothpaste); and group D = sodium bicarbonate (24K-Whitening-Pen). L*, a*, b* color-parameters were spectrophotometer-recorded at baseline (T0), one day (T1), and one month (T2) post-treatment. Changes in teeth color (ΔEab) were calculated. Data were analyzed using ANOVA and the Bonferroni test (α = 0.05). Groups A, B, and D showed significant differences in ΔL*&Δa* parameters at T1, but not in Δb* at T0. Group C showed no difference for ΔL*, Δa*, Δb* at T0 and T1. Group A showed differences for ΔL*, Δa*, Δb*, at T2, while groups B, C, and D had no difference in any parameters at T0. At T1, ΔEab values = A &gt; D&gt; B &gt; C (ΔEab = 13.4 &gt; 2.4 &gt; 2.1 &gt; 1.2). At T2, ΔEab values increased = A &gt; B &gt; C &gt; D (ΔEab = 12.2 &gt; 10.6 &gt; 9.2 &gt; 2.4). In conclusion, the 10% CP and Biomimetic polyphosphate extrinsic whitening kit demonstrated the highest color change, while simulated brushing with dark stain toothpaste and a whitening pen demonstrated the lowest color change at both measurement intervals.