Macroscopic Specimens Research Articles

First experience using a plate for fixing histological specimens of parotid salivary gland tumors

Relevance. Accurately assessing all resection margins during the removal of parotid salivary gland tumors is crucial due to the risk of recurrence and the potential for benign processes to become malignant over time. Macroscopic specimens obtained during these surgeries are sent to the pathology laboratory in containers filled with fixative solution. During fixation, the soft tissue fragments, typically round in shape, can alter their configuration because of the tissue's heterogeneity. This can create challenges for the pathologist in properly orienting the surgical specimen, which in turn complicates the precise evaluation of the resection margins.Materials and methods. To address this issue, the "Plate for fixing histological specimens of parotid salivary gland tumors" (patented) was developed. Twenty cases of its clinical use were analyzed: the surgical material (parotid gland tissue containing a tumor) was sent to the pathology department, fixed on this plate to preserve its original anatomical orientation. A macroscopic and histological evaluation of the neoplasms was then carried out, with special attention given to the accurate identification of all resection margins. In all 20 clinical cases, the use of this invention improved the convenience for the pathologist in handling the excised tissue block by standardizing the method and clearly identifying the resection margins.Conclusion. The application of this invention enhances the accuracy of marking and evaluating the resection margins in parotid gland tumors.

Plant cultivation and diversity at the Early Neolithic settlement in Biskupice in Poland

The emergence of the Linear Pottery Culture (LBK) during the Neolithic period within Polish territory 5400–4900 BC, introduced plant cultivation, yet the definitive list of cultivated species remains debated. This study examines plant assemblages (fruits, seeds, pollen, and spores) from the LBK settlement in Biskupice, southern Poland, aiming to identify cultivated and wild species used during the development of the first stable settlements in the Carpathian Foothills. Due to extensive sampling, Biskupice yielded over 11,000 macroscopic plant specimens, enabling detailed analysis of plant diversity, distribution, and implications for agrarian and dietary practices. The analysis revealed a focus on emmer and einkorn wheat cultivation, with barley playing a minor role, alongside evidence of flax and pulses. Radiocarbon dating supported the settlement’s existence in the 6th millennium BCE, and confirmed the use of barley. However, a younger date excluded bread wheat cultivation at this site. The plant assemblage included a diverse array of herbaceous wild plants like black bindweed, fat hen and brome species, suggesting their economic use. Additionally, the presence of cockspur grass, linked with Southeast Asia, indicates alternative migration routes of weeds in Europe, as supported by radiocarbon dating. Palynological analysis suggests existence of nearby cereal plots or the processing of cereals at the settlement, supporting archaeological evidence.

Multi-scale study on the mechanical properties of concrete based on crack propagation under hygrothermal coupling

During the long-term service of structures, the environmental temperature and humidity fields can lead to the evolution of the pore structure within concrete materials, thereby affecting changes in mechanical properties. However, the mechanisms of their influence still need further clarification and are challenging to correlate for prediction. Addressing this specific issue, the current study focuses on evaluating 78 cubic concrete specimens with C30 and C40 strength grades. These specimens were subjected to a 95 % humidity environment at temperatures of 40 °C, 60 °C, and 80 °C for durations of 30, 60, and 90 days. The research involved conducting both microstructural and macroscopic mechanical tests to quantify the evolution of internal hydrates, pore structures, and pore distribution, as well as to assess the changes in the macroscopic mechanical properties of the specimens. To accurately predict the process, a multiscale finite element model (FEM) based on the bilinear continuum cohesive damage model was established. This model quantifies the changes in mechanical properties of mesoscopic three-phase concrete due to microcrack evolution under hygrothermal coupling. To facilitate multiscale simulations between the Representative Volume Element (RVE) and macroscopic scale models, relevant subroutines were written using Umath, and parallel computing was employed to reduce the computational burden. For the macroscopic model in this study, a homogenized concrete cube model with dimensions identical to the experimental specimens was selected. The effectiveness of the parallel computational model was validated by comparing and analyzing the simulation results under uniaxial compression with the experimental data. The findings indicate that hygrothermal action leads to the initiation and expansion of microcracks within the concrete, thereby impacting the alteration of its mechanical properties. In addition, the parallel computing-based multiscale FEM can more accurately quantify the typical damage process of crack propagation while reducing the computational load and may provide relatively accurate predictions of the mechanical characteristics of concrete under the influence of hygrothermal coupling, ensuring effective modeling of macroscopic structural specimens in various temperature and humidity environments.

Approaching Standardization: Mechanical Material Testing of Macroscopic Two-Photon Polymerized Specimens.

Two-photon polymerization (2PP) is becoming increasingly established as additive manufacturing technology for microfabrication due to its high-resolution and the feasibility of generating complex parts. Until now, the high resolution of 2PP is also its bottleneck, as it limited throughput and therefore restricted the application to the production of microparts. Thus, mechanical properties of 2PP materials can only be characterized using nonstandardized specialized microtesting methods. Due to recent advances in 2PP technology, it is now possible to produce parts in the size of several millimeters to even centimeters, finally permitting the fabrication of macrosized testing specimens. Besides suitable hardware systems, 2PP materials exhibiting favorable mechanical properties that allow printing of up-scaled parts are strongly demanded. In this work, the up-scalability of three different photopolymers is investigated using a high-throughput 2PP system and low numerical aperture optics. Testing specimens in the cm-range are produced and tested with common or even standardized material testing methods available in conventionally equipped polymer testing labs. Examples of the characterization of mechanical, thermo-mechanical, and fracture properties of 2PP processed materials are shown. Additionally, aspects such as postprocessing and aging are investigated. This lays a foundation for future expansion of the 2PP technology to broader industrial application.

EXPERIMENTAL STUDY COMPARING THE DURATION OF PARTIAL MENISCUS RESECTION USING ARTHROSCOPIC PUNCHERS, RADIOFREQUENCY ABLATOR AND RADIOFREQUENCY INSTRUMENT FOR MENISCUS RESECTION "MENISCUS RESECTOR"

Introduction. An experimental study comparing the duration of partial resection of 500 mm3 of meniscus by a combination of arthroscopic punchers with a radiofrequency ablator and a radiofrequency resection tool "Meniscus Resector" was conducted in isolated laboratory conditions.
 The aim of the study. To determine and compare the duration of partial meniscus resection using arthroscopic punchers, radiofrequency ablator and Meniscus Resector radiofrequency resection tool in isolated laboratory conditions.
 Materials and methods. The study was conducted on 30 macropreparations of human knee menisci obtained during total knee arthroplasty, which were divided into two groups: Group 1 – 15 macroscopic specimens, partial resection of which was performed using an arthroscopic biter, and the contours of the meniscus surface after resection were treated with a radiofrequency ablator; Group 2 – 15 macroscopic specimens, partial resection of which was performed using the Meniscus Resector radiofrequency resection tool. In both groups, the same volume of meniscus was resected – 500 mm3. Visualization and timing were performed using an arthroscopic system (Smith & Nephew, USA; Loran, China). Statistical processing of the study data was performed using the licensed software IBM SPSS Statistics Base v 22. MedCalc (Healthcare Technology, USA).
 Results and Discussion. In group 1, the mean duration (median, interquartile range) of partial resection of a 500 mm3 fragment was 11.8 (10.2-12.9) seconds, in group 2, the mean duration of partial resection of a 500 mm3 fragment was 1.9 (1.4-2.3) seconds (p=0.000061). Thus, the use of the Meniscus Resector (group 2) contributed to an average of 6.2 times faster partial meniscus resection compared to arthroscopic punchers and radiofrequency ablator (group 1).
 Conclusions. The study suggests that the use of the Meniscus Resector provides a faster method of radiofrequency meniscus resection compared to arthroscopic punchers and radiofrequency ablators. Further studies and trials are needed to confirm these results and evaluate safety in different clinical settings.

Determination of crystallographic texture in polycrystalline materials from wavelength-resolved neutron transmission experiments: application to high-symmetry crystals

Wavelength-resolved neutron transmission experiments are useful for characterizing the microstructure of macroscopic specimens with 2D spatial resolution perpendicular to the beam direction. The crystallographic texture can affect the neutron transmission in the thermal neutron energy range, which manifests as changes in the shape and height of Bragg edges as a function of neutron wavelength. Models have been proposed to predict the transmission of textured polycrystalline materials from knowledge of the material texture and have proved to accurately predict the observed transmission data. In recent work, a novel method was described and tested for obtaining texture integral parameters from the combined analysis of transmission data measured along several directions of a specimen in a hexagonal crystal Zr alloy. However, this procedure has limitations when dealing with high-symmetry crystal structures. In this work, a generalization of such a method based on the expansion of the orientation distribution function (ODF) in symmetric generalized spherical harmonics that is applicable to all crystal and sample symmetries is presented. Using this method, the low-order Fourier coefficients of the ODF can be estimated by analyzing transmission data obtained for a reduced set of beam directions. This method was verified using a cubic Cu sample, for which transmission data were available along five different directions. Two sample symmetries were assumed to reduce the number of Fourier coefficients of the ODF. In the case of cylindrical symmetry (fiber-type texture), the results were good; but in the case of orthorhombic symmetry, some bias was observed which was attributed to the reduced number of beam directions used to perform the evaluation.

Multiphase elasto-plastic mean-field homogenisation and its consistent linearisation

The aim of this work is to develop a model based on incremental mean-field homogenisation methods that allows the simulation of composites with an arbitrary number of elasto-plastic material phases. The model is implemented in an implicit finite-element program, whereby, both matrix and inhomogeneities exhibit elasto-plastic material behaviour. Moreover, the implementation of the resulting constitutive equations is based on a consistent linearisation using higher order tensors. The proposed homogenisation method is evaluated by comparing it with existing methods from the literature in the context of two metal matrix composites. The target results used for comparison are obtained through computational homogenisation using FEM, taken from the literature. The overall findings indicate that the developed Mori-Tanaka method yields favourable results when compared to the existing approaches from the literature. Furthermore, a macroscopic tensile specimen with different microscopic morphologies is simulated using FEM and various mean-field homogenisation methods, including Mori-Tanaka, Voigt, Reuss, and Voigt-Reuss-Hill average. This example illustrates how the different microscopic morphologies and homogenisation methods influence the macroscopic response. Additionally, it demonstrates the successful implementation and correct linearisation of the proposed homogenisation method.

Thermally-triggered multi-shape-memory behavior of binary blends of cross-linked EPDM with various thermoplastic polyethylenes and their potential applications as temperature indicators

Shape-memory polymers (SMPs) are smart materials that can alter their configuration in response to external stimuli. They have shown promise in a number of application areas, including soft robotics or biomedical devices. Frequently, however, the materials needed are expensive, or labor-intensive synthetic processes are involved. In this contribution, we report a versatile and cost-effective manufacturing method for SMPs based on binary elastomer-thermoplastic-blends. These were produced from ethylene-propylene-diene monomer rubber (EPDM) combined with ultra-low-density polyethylene (ULDPE), propylene-ethylene copolymer (PP-c-PE), or high-density polyethylene (HDPE) as thermoplastic components. Atomic force microscopy revealed an immiscible two-phase morphology. Results of dynamic-mechanical thermal analysis showed that all polymer blends with a high thermoplastic load had efficient thermo-responsive dual-shape-memory, also demonstrated on macroscopic specimens. Furthermore, multi-shape-memory of elastomer/thermoplastic (40/60)-blends was investigated. Especially ULDPE-containing blends exhibited particularly promising multi-shape-memory features and stepless, controllable temperature response. Mechanistically, this is based upon the synergistic interaction of the cross-linked elastomer and the thermoplastic switching phase, consisting of different crystalline segments melting over a wide range from 60 to 125 °C. The continuous shape recovery over a broad temperature range could be used to create reusable test strips, e.g., for indicating exposure temperature in transportation chains or overheating protection.

Fixation and staining methods for macroscopical investigation of the brain.

The proper preservation of human brain tissue is an indispensable requirement for post-mortem investigations. Neuroanatomical teaching, neuropathological examination, neurosurgical training, basic and clinical neuroscientific research are some of the possible downstream applications of brain specimens and, although much apart from one another, proper tissue fixation and preservation is a common denominator to all of them. In this review, the most relevant procedures to fixate brain tissue are described. In situ and immersion fixation approaches have been so far the most widespread ways to deliver the fixatives inside the skull. Although most of them rely on the use of formalin, alternative fixative solutions containing lower amounts of this compound mixed with other preservative agents, have been attempted. The combination of fixation and freezing paved the way for fiber dissection, particularly relevant for the neurosurgical practice and clinical neuroscience. Moreover, special techniques have been developed in neuropathology to tackle extraordinary problems, such as the examination of highly infective specimens, as in the case of the Creutzfeldt-Jakob encephalopathy, or fetal brains. Fixation is a fundamental prerequisite for further staining of brain specimens. Although several staining techniques have been developed for the microscopical investigation of the central nervous system, numerous approaches are also available for staining macroscopic brain specimens. They are mostly relevant for neuroanatomical and neuropathological teaching and can be divided in white and gray matter staining techniques. Altogether, brain fixation and staining techniques are rooted in the origins of neuroscience and continue to arouse interest in both preclinical and clinical neuroscientists also nowadays.

In-situ observation of the incipient melting of borides and its effect on the hot-workability of Ni-based superalloys

The excellent creep properties of advanced wrought Ni-based superalloys are achieved by adding grain boundary strengthening elements such as B and C. Their low solubility in the γ matrix may promote precipitation of micrometre-sized borides and carbides which potentially deteriorate hot-workability, e.g. through incipient melting. However, their incipient melting has not yet been directly linked to a decrease in hot-workability in Ni-based superalloys. Here, we study the susceptibility of two Ni-based superalloy variants with main differences in B and C contents (high B & C variant with>triple B and C contents) to incipient melting and its effect on hot-workability. We show that incipient melting causes severe intergranular cracking at low strains during compression at 1200 °C in the high B & C variant only. Compression to higher strains separates grain boundaries fully, partially pulverising the macroscopic specimen. Metallographic specimens already show incipient melting at heating rates they experience when put into a pre-heated furnace. During subsequent cooling, the melt re-solidifies and forms lamellar structures consisting of various phases rich in Mo-Cr-B, Zr, and Ti, the constituents of M3B2 and MC. In-situ observations using a customised high temperature confocal laser scanning microscope set-up unambiguously confirmed the origin of these lamellar structures. We demonstrate for the first time directly the constituent liquation of M3B2. This liquation is assumed to be aided by the partial dissolution of adjacent MC carbides into the melt. These results will help to improve thermo-mechanical simulations and microstructural control during industrial processing of advanced wrought superalloy parts.

Establishment of an orthotopic model of lung cancer by transthoracic lung puncture using tumor fragments.

Orthotopic models of lung cancer have been widely utilized, and the purpose of this study was to demonstrate the viability of our proposed modified modeling approach. A total of 50 female BALB/c mice were implanted with 1×1×1 mm fragments of a tumor sample into the left lung lobe. After 2 months of observation, the mice were humanely euthanized through CO2 inhalation. The macroscopic specimens were photographed, and the most representative neoplastic lesions were collected for histological analysis. Small-animal positron emission tomography/computed tomography (PET/CT) scans were conducted on 6 randomly selected mice. Local tumor formation, ipsilateral thoracic tissue infiltration, the contralateral chest wall, right lung metastases, and distant kidney metastases were observed in these models. Overall, the tumor development and metastasis rates were 60.86% (28/46) and 57.14% (16/28), respectively. The 3 mice that had a small-animal PET/CT scan developed a local tumor, but no distant metastases were observed. This modified method was deemed reliable, reproducible, minimally invasive, straightforward, and comprehensible; it might serve as the foundation for developing patient-derived orthotopic xenografts of lung cancer.

Non-invasive Monitoring of Soft-tissue Sarcoma Response to Neoadjuvant Radiotherapy by Quantification of Circulating Tumor DNA (ctDNA) and Multiparametric MRI (mpMRI)

Introduction: Soft-tissue sarcomas (STS) are a heterogenous group of rare, yet malignant tumors. Wide resection remains the cornerstone of treatment for localized STS. Current S3 guidelines recommend neoadjuvant radiotherapy for primary, high-grade tumors; however, therapy response for different histological subtypes and gradings has not been systematically investigated. This ongoing prospective study evaluates the response of various STS during the course of neoadjuvant radiotherapy using innovative, non-invasive methods. Through quantification of ctDNA, tumor activity and thus therapy response will be evaluated in correlation with imaging data. Materials and Methods: Liquid biopsies: Detection of circulating tumor DNA (ctDNA) in patient blood samples through targeted next-generation sequencing (NGS). Patient-specific exome sequencing allows the detection of individual structural variants (SVs) and point mutations. Circulating free DNA (cfDNA) is isolated from peritherapeutically collected patient plasma samples and ctDNA quantified therein. Bioinformatic analysis is performed using the MIRACUM Pipeline. Multiparametric MRI (mpMRI): Combination of conventional MRI sequences with diffusion-weighted imaging (DWI) and dynamic contrast enhancement (DCE). Multiparametric MRI is performed before, during, and after neoadjuvant radiotherapy. Accurate co-registration and correlation of mpMRI with the macroscopic, histologic, and immunohistochemical resected specimen allow an analysis of morphological changes during therapy. Results: Quantification of ctDNA mirrors the clinical course and tumor activity. Furthermore, we present imaging markers that allow the characterization of tumor masses for heterogenous STS and the evaluation of therapy response. Conclusion: Liquid biopsies can be used to detect the primary tumor and metastases, and to monitor the course of therapy. Quantification of ctDNA in combination with tumor mass characterization through co-registration of mpMRI and histopathology enables the evaluation of STS response to neoadjuvant radiotherapy. The participation and support of a wider group of oncologic surgeons are needed to validate these findings on a larger patient cohort to create future tumor- and patient-specific therapy concepts.

Applied use of biomechanical measurements from human tissues for the development of medical skills trainers: a scoping review protocol.

The objective of this scoping review is to identify the availability of quantitative biomechanical measurements from human tissues. This review also considers the primary motivations for collecting biomechanical measurements of human tissues. The overall purpose of our research is to develop medical skills trainers that provide better haptic fidelity than those that are currently available. Medical skills trainers are commonly used in clinician training, but trainers do not always have the same haptic properties as patients. This could be due to the limited availability or application of documented biomechanical properties of human tissues when developing trainers. This scoping review will examine studies that have quantitatively measured the mechanical properties of human tissues. Only macroscopic specimens will be included, and articles primarily considering optical, acoustic, and thermal properties will be excluded. Included sources of evidence are from primary research, systematic reviews, meta-analyses, and conference proceedings. This review will follow the JBI methodology for scoping reviews. Sources of evidence will be extracted from CINAHL, IEEE Xplore, MEDLINE, Scopus, and biomedical engineering conference proceedings. The search is limited to articles in English. Full articles will be retrieved if their title or abstract meet the inclusion criteria. Tabular, visual, and narrative summaries will be used to present the results.

Biodegradable Polylactide Supraparticle Powders with Functional Additives for Biomedical Additive Manufacturing

AbstractAdditive manufacturing, in particular powder bed‐based fabrication processes hold promise to revolutionize biomedical engineering for the ability to provide customized, functional implants, for example as bone replacement materials. However, providing functional powder particles that unify material requirements for biodegradable and bioactive biomaterials and process requirements to enable successful powder bed fusion remains an unmet challenge. Here, a supraparticle‐based approach to create biodegradable poly(lactic acid) and composite powders for the additive manufacturing of bone replacement materials is introduced. Colloidal binary Ca‐SiO2 glasses and hydroxyapatite are incorporated as bioactive functional additives to support the formation of bone‐like calcium phosphate. The supraparticle powders are prepared by a scalable spray‐drying process, which offers control of particle size, shape, and composition. All process‐relevant powder characteristics are analyzed as a function of composition and structure, including flowability, thermal, and melt rheological properties. The optimized supraparticle powders are successfully used in the process of laser powder bed fusion of polymers to prepare macroscopic specimens via additive manufacturing. It is demonstrated that the material combination of the composites provides relevant functional properties, including biodegradation and bioactivity. The process provides a flexible and adjustable toolbox for the design of functional powders toward biomedical additive manufacturing.

Aberrant hypomethylation at imprinted differentially methylated regions is involved in biparental placental mesenchymal dysplasia

BackgroundPlacental mesenchymal dysplasia (PMD) is a morphological abnormality resembling partial hydatidiform moles. It is often associated with androgenetic/biparental mosaicism (ABM) and complicated by Beckwith–Wiedemann syndrome (BWS), an imprinting disorder. These phenomena suggest an association between PMD and aberrant genomic imprinting, particularly of CDKN1C and IGF2. The existence of another type of PMD containing the biparental genome has been reported. However, the frequency and etiology of biparental PMD are not yet fully understood.ResultsWe examined 44 placental specimens from 26 patients with PMD: 19 of these were macroscopically normal and 25 exhibited macroscopic PMD. Genotyping by DNA microarray or short tandem repeat analysis revealed that approximately 35% of the macroscopic PMD specimens could be classified as biparental, while the remainder were ABM. We performed a DNA methylation analysis using bisulfite pyrosequencing of 15 placenta-specific imprinted differentially methylated regions (DMRs) and 36 ubiquitous imprinted DMRs. As expected, most DMRs in the macroscopic PMD specimens with ABM exhibited the paternal epigenotype. Importantly, the biparental macroscopic PMD specimens exhibited frequent aberrant hypomethylation at seven of the placenta-specific DMRs. Allelic expression analysis using single-nucleotide polymorphisms revealed that five imprinted genes associated with these aberrantly hypomethylated DMRs were biallelically expressed. Frequent aberrant hypomethylation was observed at five ubiquitous DMRs, including GRB10 but not ICR2 or ICR1, which regulate the expression of CDKN1C and IGF2, respectively. Whole-exome sequencing performed on four biparental macroscopic PMD specimens did not reveal any pathological genetic abnormalities. Clinical and molecular analyses of babies born from pregnancies with PMD revealed four cases with BWS, each exhibiting different molecular characteristics, and those between BWS and PMD specimens were not always the same.ConclusionThese data clarify the prevalence of biparental PMD and ABM-PMD and strongly implicate hypomethylation of DMRs in the pathogenesis of biparental PMD, particularly placenta-specific DMRs and the ubiquitous GRB10, but not ICR2 or ICR1. Aberrant hypomethylation of DMRs was partial, indicating that it occurs after fertilization. PMD is an imprinting disorder, and it may be a missing link between imprinting disorders and placental disorders incompatible with life, such as complete hydatidiform moles and partial hydatidiform moles.

Collision tumor of the appendix incidentally discovered in a patient diagnosed with an adenocarcinoma of the colon: a case report.

Collision tumor of the appendix is an extremely rare entity, defined as the coexistence of two independent tumors located in the same site without transitional changes. We describe in this report the case of a 75-year-old man who presented with an acute abdominal pain, nausea and vomiting. Physical examination revealed an abdominal distension with a hypogastric mass. Abdominal computed tomography showed colonic obstruction related to a sigmoid tumor. Therefore, a total colectomy was made. Macroscopic specimen examination showed a sigmoid tumor associated to a cystic dilatation of the appendix tip with mucoid content. Histological examination of the appendix showed the co-existence of two independent tumors located in the tip, without transitional changes: pTis low-grade appendiceal mucinous neoplasia and grade 1 neuroendocrine tumor. The latter was discovered incidentally during histological examination. We draw attention through our presentation to the importance of a thorough macroscopic and histological examination of the appendix.

The coronary sinus and adjacent structures in human adult hearts: morphometrical cadaveric anatomy

The aim of this study was to explore the anatomy and morphometry of the coronary sinus in hearts of adult humans, clarify position of the sinus to left atrium, left fibrous ring and adjacent arteries and describe topographic variants for adjacent anatomy of the coronary sinus in hearts of various types of coronary dominance. We studied 40 hearts weighing 200-420 g, obtained from patients who died from non-cardiac causes. We dissected 30 non-injected macroscopic specimens preserved into 4% PBS formalin to reveal and measure coronary sinus and neighboring coronary arteries. The rest 10 hearts we used for preparing histological slices from the points of the beginning of the sinus, in the middle, and near the “crux cordis”. We measured large and small diameters, circumference, wall thickness of the coronary sinus, as well as explored relative position of the coronary sinus, adjacent arteries, left atrium and left fibrous ring. The reference range of coronary sinus length was 33.76-48.4 mm. The median (Me) of the circumference of the coronary sinus increased from 13.87 mm at the beginning of the sinus to 23.99 mm at the “crux cordis”. In some specimens, the cross section of the sinus looked flattened in the anteroposterior direction; in others, it appeared to be flattened basoapically. We distinguished two anatomical patterns of the coronary sinus: subepicardial and intramyocardial. The first we proposed to term myocardialless or, simply, “naked”, and the second type we named muscularized. We proposed to divide the latter into partially and completely muscularized. Lack of adventitia between the myocardial sheet and tunica media of the coronary sinus allowed us to consider myocardial sleeves as an integral structure of the intramyocardial sinus wall. The wall thickness value of the coronary sinus at the point of origin, in the middle, and at the point of its turning anterosuperiorly toward the right atrium had no differences, but significantly depended on the myocardial cover and on the position of the coronary sinus in the left atrioventricular sulcus. The distance from the sinus to the posterior wall of the left atrium was 0.15-7.66 mm (Me 0.91 mm); the distance to the left fibrous ring was 2.9-13.7 mm (Me 7.9 mm). We found four variants of topographic and anatomical relations of the sinus and its adjacent arteries. Commonly, arteries were located below the coronary sinus. The ranges of variability of morphometric values of the coronary sinus and neighboring structures may be considered as reference values of the anatomy of the coronary sinus in the normal human adult heart.

Prevalence and molecular assessment of Sarcocystis infection in livestock in northeast Iran

Sarcocystis is an intracellular parasite of the apicomplexa phylum. More than one hundred species of Sarcocystis can infect wildlife and livestock animals. Samples of the liver, heart, muscle and diaphragm were collected from sheep, goats and cattle in Gonabad, northeast Iran and subjected to macroscopic, microscopic, tissue digestion, sequencing and phylogenetic analyses of 18S-rRNA region. Tissue sections stained with hematoxylin and eosin were also provided for surveying sarcocysts in the samples. Tissue digestion showed that all animal samples (100%) were infected with Sarcocystis bradyzoites. Phylogenetic analysis indicated that out of 50% of sheep genotypes belonged to S. tenella, and 20% to S. moulei and S. arieticanis. Moreover, three samples of macroscopic specimens of sheep were identified as S. gigantea, 100% of cattle isolates infected with S. cruzi, 80% of goat isolates belonged to S. capracanis and one macroscopic specimen of goat (20%) identified as S. moulei. Sarcocystis infection is highly prevalent in livestock in northeast Iran, where a variety of Sarcocystis species are unequivocally circulating in the region.

Comparison of Different Tissue Clearing Methods for Three-Dimensional Reconstruction of Human Brain Cellular Anatomy Using Advanced Imaging Techniques.

The combination of tissue clearing techniques with advanced optical microscopy facilitates the achievement of three-dimensional (3D) reconstruction of macroscopic specimens at high resolution. Whole mouse organs or even bodies have been analyzed, while the reconstruction of the human nervous system remains a challenge. Although several tissue protocols have been proposed, the high autofluorescence and variable post-mortem conditions of human specimens negatively affect the quality of the images in terms of achievable transparency and staining contrast. Moreover, homogeneous staining of high-density epitopes, such as neuronal nuclear antigen (NeuN), creates an additional challenge. Here, we evaluated different tissue transformation approaches to find the best solution to uniformly clear and label all neurons in the human cerebral cortex using anti-NeuN antibodies in combination with confocal and light-sheet fluorescence microscopy (LSFM). Finally, we performed mesoscopic high-resolution 3D reconstruction of the successfully clarified and stained samples with LSFM.

A Numerical Approach to Multiscale Simulation of Cement Paste Strength

Recent experimental investigations on the nanoscale of hardened cement paste revealed that the tensile strengths of the microstructural phases present amount to several hundreds of MPa. Confrontation with macroscopic tensile strength testing, by e.g. Brazilian splitting, shows a decrease over two orders of magnitude. A computational model based on a hierarchical representation of hardened cement paste microstructure is presented in this paper, attempting to shed light on the factors affecting the scaling of strength from the nanoscopic scale up to the macroscopic scale. The model is validated on a case study featuring a Portland-limestone cement paste subjected to an external sulfate attack. Such conditions compromise the nanoscopic integrity of the C-S-H gel as a consequence of the progressive decalcification and affect the overall load-bearing capacity of the macroscopic cement paste specimen.