Homogeneous Mass Research Articles

Comparative morphological assessment of crosslinked and non-crosslinked xenograft biointegration quality

Relevance. Autografts are nowadays the gold standard for soft tissue augmentation and gingival recession coverage. However, as this method has a number of significant disadvantages, xenografts of various origins are more frequently used in dental practice. The study aimed to conduct a comparative morphological assessment of crosslinked and non-crosslinked xenogenous scaffold biointegration quality at different healing times.Materials and Methods. The study used 108 Wistar rats (54 males, six months old, fat mass 462 ± 20; 54 females, six months old, fat mass 414 ± 7) and randomly divided them into three groups. Group 1 had a xenogenous collagen matrix (Mucograft) placed in the subperiosteal tunnel in the mandibular vestibule area; Group 2 had an acellular dermal collagen matrix (Mucoderm) implanted in the subperiosteal tunnel, group 3 had D-ribose crosslinked xenogenous scaffold (Ossix Volumax) placed in the subperiosteal tunnel.Results. The studied xenogenous materials showed different integration and biodegradation extents. By postoperative day 7, Group 1 (Mucograft) showed a more pronounced inflammation. Non-crosslinked collagen materials had almost completely resorbed by the 30th day of observation, while a crosslinked collagen matrix was detected as homogenous masses. By the 90th day, all groups demonstrated the formation of new connective tissue with different functional characteristics; only Group 3 histologically revealed microfragments of the graft.Conclusion. The study shows that the xenogenous crosslinked and non-crosslinked collagen membranes may promote an increase in soft tissue thickness to a different extent. However, it is essential to improve the available materials to reach an outcome comparable to the autologous soft tissue graft treatment result.

Grain-scale numerical simulation of crystalline rock fracturing using Soundless Cracking Demolition Agents for in-situ preconditioning

Soundless Cracking Demolition Agents (SCDAs) are becoming increasingly popular for near-surface underground rock fragmentation applications. Several studies have been carried out to accurately simulate the fracturing processes of SCDA under its volumetric expansion inside a borehole. These numerical simulations and experiments have been limited mainly to homogeneous and intact rock masses in most cases. In this paper, we present a numerical approach that assesses the influence of mineral heterogeneity and rock mass defects (pore structures) on the fracturing performance of SCDA at the grain size level. For the simulation, a numerical crystalline rock grain assembly was generated using NEPER (a polycrystal generation tool) to introduce spatial variability of grain size that closely mimicked the grain arrangement of granitic rock. The assembly was then imported to 3-Dimensional Distinct Element Code (3DEC) as a block-based model. Heterogeneity was introduced to the model in terms of both mineralogical spatial distribution and strength variation. Pore spaces were introduced to the model using random grain deletion in the rock model. Intergranular and transgranular fracturing of the assembly was also simulated by utilizing a dual-layer discretization technique in 3DEC. SCDA charged fracture simulation was carried out in the model using a single central injection well. The results suggest intergranular fracturing to be the dominant mode of fracturing with additional grain crushing (transgranular fracturing) in the vicinity of the injection well. Grain size and in-situ stress anisotropy largely affect the direction and geometry of radial fractures initiated around an injection well during SCDA charging. The stress concentrations introduced by the pore structures of the matrix were found to have a strong influence on crack deflection, additional micro-cracking in the matrix and final tortuosity of the fractures produced. The results presented in this paper suggest that the micro-mechanical heterogeneity of the rock mass significantly influences the final fracture pattern produced by SCDA charging and therefore should be given more attention during crystalline rock pre-conditioning applications.

Изучение качества полуфабриката из ядер семян Pinus sibirica

Cedar-pine nut kernels are tasty and nutritious, which makes them a popular raw material. This research featured the effect of mechano-acoustic treatment on the quality of a novel semi-finished product from Pinus sibirica kernels.
 The production technology included the following stages. A mix of kernels and water underwent mechano-acoustic treatment (100–500 W/kg) at 63–67°C for 20 min. After that, the mix was packaged, cooled, and stored in plastic jars at 2–6 and –18–22°C. The study relied on conventional and standard research methods.
 The resulting light-cream homogeneous mass had a characteristic aroma and taste of cedar-pine nuts. Its nutrient composition was close to the original raw material: protein – 7.4%, fat – 22.6%, sugar – 1.4%, fiber – 1.4%, ash – 1.03%. However, the quantity of mesophilic aerobic and facultative anaerobic microorganisms decreased by three orders of magnitude and that of yeast decreased by six times. In addition, the semi-finished product contained no non-spore-forming Escherichia coli. A set of sensory, physico-chemical, and microbiological tests revealed the shelf life of 14 days at 2–6°C and 24 months at –18–22°C.
 The mechano-acoustic homogenizer made it possible to obtain a high-quality semi-finished product from Pinus sibirica nut kernels with a simple production technology, long shelf life, and great commercial potential.

Carbonate cementing minerals in rhizoliths from Badain Jaran Desert: Implication for pedo-diagenesis and environment of dune soil

Pedogenic carbonates are a good proxy of soil formation and functioning because the morphology of minerals is directly related with the processes of dissolution–precipitation. Carbonate rhizolith is one type of pedogenetic carbonate forming in modern soils of dunes and loess. The calcite micro-morphology with the sedimentary hydrogeochemical conditions prevailing during their formation remains open. Electron microscopy with an X-ray energy dispersive spectrometer and X-ray diffraction were used to investigate in detail the micro-morphology of carbonate cements of the rhizoliths and obtain paleoenvironmental information in the dune soil of Badain Jaran Desert in Northwest China. Two types of carbonates rhizoliths, primary rhizoliths (PR) and reworked rhizoliths (RR), were found. The PRs are present in situ within dune soils. The RRs are being eroded out from soil, potentially dislocated or transferred, and weathered at the soil surface. PRs displayed homogeneous micritic mass of calcite crystals, with pores, cavities and voids among the mass. RRs displayed various morphologies of calcite crystals (polyhedral, euhedral rhombic, tooth-like, prismatic and pillar), rosettes, short rods, and calcified fungal hyphae. The diagenesis differences at soil depth and surface affected the crystal morphologies. The homogeneous micritic mass of calcite crystals of the PRs were formed during the early diagenesis, preferentially in wet soils with semi-closed and semi-redox conditions. In contrast, the cementing minerals of the RRs became bigger and clearer in the late diagenesis than during early diagenesis due to recrystallization in open, dry and oxidative conditions at the soil surface. Therefore, the cement crystal morphologies of the rhizoliths can reflect the local environmental and climatic conditions. These objects can be used as environmental and pedo-diagenesis proxies in dune soil or sediments, recording the associated conditions of moisture, temperature, wind, erosion, weathering, solar radiation at the soil surface or at depth. Therefore, assessing the micromorphology of pedogenic carbonates has important implications for soil ecology and evolution as well as plant root physiology in deserts.

Primary Clear Cell Adenocarcinoma of the Uterine Cervix in a 14-Year-Old Virgin Girl: Case Report

Cervical cancer is rare in adolescent and pediatric populations, with adenocarcinoma being the most commonly reported. Clear cell adenocarcinoma of the uterine cervix accounts for only 4% of all adenocarcinoma cases, and about two-thirds are associated with intrauterine diethylstilbestrol (DES) exposure. We report the case of a 14-year-old virgin girl who presented with a 1-month-long history of abnormal vaginal bleeding and lower abdominal pain. Transabdominal pelvic ultrasound examination revealed the presence of an irregular, homogeneous cervical mass that was 7 cm in size. Therefore, a magnetic resonance imaging (MRI) scan was performed to establish the origin of the tumor and its relationship to adjacent pelvic organs. Furthermore, a vaginoscopy was performed to identify the tumor, and a cervical biopsy was performed. Immunohistochemical and anatomopathological studies resulted in the diagnosis of non-HPV(Human Papilloma Virus)-related clear cell adenocarcinoma of the cervix. Following the oncological examination, she was admitted for radiotherapy. The patient had no maternal history of DES exposure in utero. Even though the number of cases in the literature is low, most of the virgin girls diagnosed with clear cell adenocarcinoma of the cervix have a fatal prognosis because of the delay in making a correct diagnosis.

Face stability analysis of circular tunnels in layered rock masses using the upper bound theorem

An analysis of tunnel face stability generally assumes a single homogeneous rock mass. However, most rock tunnel projects are excavated in stratified rock masses. This paper presents a two-dimensional (2D) analytical model for estimating the face stability of a rock tunnel in the presence of rock mass stratification. The model uses the kinematical limit analysis approach combined with the block calculation technique. A virtual support force is applied to the tunnel face, and then solved using an optimization method based on the upper limit theorem of limit analysis and the nonlinear Hoek–Brown yield criterion. Several design charts are provided to analyze the effects of rock layer thickness on tunnel face stability, tunnel diameter, the arrangement sequence of weak and strong rock layers, and the variation in rock layer parameters at different positions. The results indicate that the thickness of the rock layer, tunnel diameter, and arrangement sequence of weak and strong rock layers significantly affect the tunnel face stability. Variations in the parameters of the lower layer of the tunnel face have a greater effect on tunnel stability than those of the upper layer.

Process optimization of functional processed mozzarella cheese using response surface methodology

Processed Mozzarella Cheese (PMC) is manufactured by using shredded Mozzarella cheese in the presence of heat, emulsifying salts, and sodium chloride to produce a homogenous glossy mass of cheese with extended shelf life. The aim of the present study was to develop functional PMC by incorporating rennet Coagulated Gel (RCG), whey protein hydrolysate (WPH) and emulsifying salts. The incorporation of tri sodium citrate (TSC) at 1.5 and 2.0% showed improvement in meltability but stretchability was adversely affected. Therefore, a combination of 3 different emulsifiers were incorporated by keeping the total emulsifiers content at 1.5% in PMC. To improve the stretchability, RCG of 5–15% was added to PMC. Also, some part of 15% RCG was replaced with WPH to increase bio functional properties in PMC. The concentration of RCG and WPH was standardized using mixture component-optimal custom design of response surface methodology. The design revealed that RCG and WPH at 11.98% and 3.02% respectively was best to obtain maximum meltability and stretchability in PMC. The peptide profile of optimized PMC was compared with Mozzarella cheese, other PMC variants and standard (casein) using Electrophoresis. It was observed that β and α-casein bands became more intact on adding RCG as compared to Mozzarella cheese. The contribution of peptides from WPH increased the number of low molecular weight peptides in optimized PMC.

A primary cardiac schwannoma of the right ventricle: a case report and literature review

BackgroundPrimary cardiac schwannoma remains extremely rare and difficult to distinguish from other myocardial tumours. We report a case of cardiac schwannoma that occurred in the lateral wall of the right ventricle and grew in the myocardial walls. It is the third case of schwannoma that occurred in the free wall of the right ventricle. Moreover, we reviewed and summarised the literature for cases involving benign cardiac schwannomas.Case presentationWe present a case of a 64-year-old woman who presented to our centre with syncope for 1–2 min. Echocardiogram and contrast-enhanced computed tomography subsequently revealed a 2.9 × 1.9 cm homogeneous mass originating from the anterior wall of the right ventricle. The patient underwent thoracotomy to resect the mass, which was pathologically verified as Schwann cell tumour.ConclusionsThis is a rare case added to the limited existing literature on cardiac schwannoma. Comprehensive analysis of various imaging examinations is helpful to determine the extent of the tumour. Complete surgical resection is recommended for similar cases involving cardiac schwannomas, especially when the patient has related symptoms. Patients generally have a good prognosis. The pathogenesis of cardiac schwannoma needs further research in order to prevent and manage this rare lesion.

Development, gut health, and longevity of European bee on the provision of biosugar syrup

Syrup containing monomeric sugars was prepared from banana-peel waste by hydrolyzing it with cellulose as well as pectinase to feed honeybees instead of using sucrose syrup in the period when there is no nectar in flowers. This syrup was provided to the caged workers with and without the addition of monomeric sugars (glucose, fructose) for a period of two weeks. It was observed that worker bees belonging to experiment No. 2 (pollens + 25% w/v glucose in BPW sugar syrup) had a significant increase in longevity. In addition to this, morphometric and histological analyses were also done. Morphometric studies confirmed reasonable increases in different body parameters of worker bees. Their hypopharyngeal gland became developed with a mean acinal surface value of 0.019 ± 0.0 mm2 as compared to the control's 0.0124 ± 0.0 mm2. Sections of the midgut (stomach) and small intestine up to 8 μm were prepared and observed under camera fitted microscope. Bees of experiment No. 2 had peritrophic membranes in close contact with rabdorium-like control bee's midgut, nuclei stained hyper chromatic, considerable increase in gastric cells discharging, and compact and homogeneous mass of semi-digested pollens in the central part of the intestinal lumen which indicates the improved digestion. The mean midgut lumen diameter was 450 ± 34.6 μm2 as compared to the control's 240.0 ± 30.5 μm2 and the mean intestinal lumen diameter was 223.3 ± 33.3 μm2 as compared to the control's 113.3 ± 38.4 μm2 which is an indication of tissue development. In the end, it is concluded that the use of biosugar syrup is good alternative to sucrose sugar syrup for honeybees.

PSAT340 Thymic Hyperplasia in Graves’ Disease: A Case Report

Abstract Background Thymic hyperplasia (TH) can occur in Graves’ disease (GD) due to direct effect of thyroid hormone or thyrotropin receptor antibody stimulation. Recognition of this entity is important as treatment of GD can lead to reduction in TH and can prevent unnecessary intervention. This case highlights thymus enlargement likely due to TH in the setting of GD. Case A 44-year-old female with history of left-sided invasive breast cancer status post partial mastectomy and radiation therapy, was found to have an anterior mediastinal mass on surveillance breast MRI. Follow-up chest CT and MRI showed a homogenous anterior mediastinal mass (4.7×2.4×12.6 cm) and thyromegaly. She had a prior history of Hashimoto's thyroiditis diagnosed 20 years, not on treatment, as well as active tobacco use (0.5 PPD for 10 years). She had symptoms of weight loss, palpitations, heat intolerance and tremors. Physical examination revealed tachycardia, flushing, lid lag, diffusely enlarged thyroid and fine tremors. Laboratory investigation showed TSH < 0.01 uIU/mL (0.35-4.94 uIU/mL), free T4 2.84 ng/dL (0.5-1.39 ng/dL), total T3 479 ng/dL (48-178 ng/dL), positive TPO, TSI and thyroglobulin antibodies confirming GD. She was initially treated with methimazole and propranolol with plans for thymectomy. Treatment was complicated by methimazole induced agranulocytosis with absolute neutrophil count of 114 cells/uL (1500-7800 cells/uL) requiring hospitalization. Methimazole was discontinued, and she was treated with antibiotics, propranolol, prednisone, cholestyramine and potassium iodide before undergoing total thyroidectomy. Pathology was consistent with GD with an incidental 2 mm papillary thyroid microcarcinoma. Post-operatively she was started on levothyroxine. Follow up CT chest two weeks after surgery showed a decrease in size of the mediastinal mass supporting a diagnosis of TH secondary to GD. She is planned for repeat imaging in several months to determine if thymectomy is indicated. Discussion TH can occur in GD secondary to direct trophic effect from excess thyroid hormones or thyrotropin receptor antibody stimulation. Prevalence is unknown; however, studies have shown that approximately one-third of patients with GD have histological evidence of TH. In most documented cases, thymic enlargement is minimal; a 2014 study found 107 documented cases of GD related thymus enlargement, of which only 4 were malignant. Since anterior mediastinal masses can have a high malignancy potential, it is warranted to thoroughly evaluate the radiographic characteristics for malignancy including heterogeneous enhancement, invasion to surrounding structures, and presence of calcification. However, in the presence of untreated hyperthyroidism and absence of suspicious radiographic features, tissue biopsy or thymectomy should be avoided due to high risk of complications such as thyroid storm. TH in GD is often reversible with treatment of GD. Follow up chest imaging to look for decrease in size of thymus is recommended to reevaluate future need for biopsy or thymectomy. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome: A Case Report

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is <10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma. PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PMON85 Co-occurrence of Carotid Body Tumor, Meningioma and Schwannoma in a Symptomatic Patient, Incidental Findings Vs Genetic Syndrome; a case report.

Abstract Carotid body tumors, also known as chemodectomas/paraganglionomas; are rare neuroendocrine tumors that arise from parasympathetic ganglionic cells. They are usually benign with incidence of malignancy is <10%. In majority of cases, tumors are asymptomatic and found incidentally on clinical exam or radiological imagining. Their association with other non-neuroendocrine tumors as seen in present case; has not been well documented in literature. Case presentation 43 y/o female with PMH of GERD, obesity, asthma and anxiety disorder who came to endocrine clinic for left middle thyroid lobe nodule(0.9×0.6×0.6cm) evaluation; incidentally noted to have a multilobulated heterogeneous hypo echoic and iso-echoic mildly vascularized solid nodular mass (3.46×1.83×1.93 cm) in the left carotid bifurcation area; splaying the common and the internal carotid arteries on US. Review of systems was positive for left sided neck pain, intermittent palpitations, headaches, anxiety, and sleep disturbances. Clinical exam was remarkable for thyromegaly and a palpable non-tender 3cm left neck mass with no cervical lymphadenopathy. Initial labs were notable for mild elevation of chromogranin A (108.4 ng/ml) with normal levels of TSH, free T3, free T4, plasma metanephrines and 24-hour urinary metanephrines. Considering patient's persistent symptoms; plasma catecholamines levels were done and were negative. MRI soft tissue neck confirmed 2.8 cm lobular mass suggestive of paraganglioma. Metastatic work up was negative. Patient was referred for genetic testing considering young age and to rule out hereditary disorders. Interim, patient presented to the ED with complain of sudden onset lumbar backache without sphincteric involvement; neurological exam was unrevealing but on MRI lumbar spine found to have a 5.7×4.8×4cm lobulated well-circumscribed homogeneous soft tissue mass suggestive of schwannoma. Cervical and thoracic spine imaging was unremarkable. MRI brain showed a 1.1cm enhancing mass in right Meckel cave suggestive of meningioma.PET-DOTATATE scan was performed that revealed left neck mass as intensely avid, Right petrous apex mass as moderately avid and lumbar mass as not avid at all, consistent with the diagnosis of paraganglionoma, meningioma and schwannoma respectively. No evidence of DOTATATE avid nodal/ distant metastatic disease was found. Initially a hereditary etiology was suspected but genetic testing including (VHL, NF1/2, SDHD, SDHB) came back negative. Case was discussed with multidisciplinary teams; Neurosurgery service recommends conservative management of both meningioma and schwannoma at the moment considering benign course. Regarding paraganglioma, as tumor is non-secretory on repeated work up; sympathetic blockade is not warranted and patient is scheduled for pre-op embolization and surgical resection by Head and Neck surgery. Conclusion Paraganglionomas are generally benign non-secretory tumors that usually occur with other neuroendocrine tumors both as hereditary syndromes and sporadic cases. But their association with non-neuroendocrine tumors is mere incidental or has a genetic causation; is still unclear and warrants further research. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Fluorine-free water-based Ni-rich positive electrodes and their performance in pouch- and 21700-type cells

In recent years substantial progress has been made in the lab-scale aqueous processing of cathode electrodes containing Ni-rich active materials such as LiNi0.83Co0.12Mn0.05O2. Now it has to be proven in production-scale that such an environmentally-friendly, water-based process will deliver cells with competitive performance. We demonstrate the upscaling of a carboxymethyl cellulose and styrene-butadiene rubber based electrode-coating recipe from 250 mL lab-scale to 10 L production-scale by coating a double-sided electrode with 140 m length, very homogeneous mass loading, and excellent roll to roll processability. Several challenges such as the control and stabilization of slurry pH and fine adjustment of the mixing and coating time have been solved. The organic- and H2O-based pilot scale cathode electrodes with areal capacities of 3.0 mAh cm−2 were characterized in pouch- and 21700-type cylindrical cells. The cells were cycled at room temperature and 45 °C for up to 2000 cycles at 1C/1C. Pouch cells containing H2O-based electrodes show a high capacity retention of 79.3% after 1000 cycles. Similarly, H2O-based electrodes built into 21700-type cells with 3.5 Ah capacity achieved 80% after 1000 cycles at 1C/1C cycling.

Temporal optimization of radiation therapy to heterogeneous tumour populations and cancer stem cells.

External beam radiation therapy is a key part of modern cancer treatments which uses high doses of radiation to destroy tumour cells. Despite its widespread usage and extensive study in theoretical, experimental, and clinical works, many questions still remain about how best to administer it. Many mathematical studies have examined optimal scheduling of radiotherapy, and most come to similar conclusions. Importantly though, these studies generally assume intratumoral homogeneity. But in recent years, it has become clear that tumours are not homogeneous masses of cancerous cells, but wildly heterogeneous masses with various subpopulations which grow and respond to treatment differently. One subpopulation of particular importance is cancer stem cells (CSCs) which are known to exhibit higher radioresistence compared with non-CSCs. Knowledge of these differences between cell types could theoretically lead to changes in optimal treatment scheduling. Only a few studies have examined this question, and interestingly, they arrive at apparent conflicting results. However, an understanding of their assumptions reveals a key difference which leads to their differing conclusions. In this paper, we generalize the problem of temporal optimization of dose distribution of radiation therapy to a two cell type model. We do so by creating a mathematical model and a numerical optimization algorithm to find the distribution of dose which leads to optimal cell kill. We then create a data set of optimization solutions and use data analysis tools to learn the relationships between model parameters and the qualitative behaviour of optimization results. Analysis of the model and discussion of biological importance are provided throughout. We find that the key factor in predicting the behaviour of the optimal distribution of radiation is the ratio between the radiosensitivities of the present cell types. These results can provide guidance for treatment in cases where clinicians have knowledge of tumour heterogeneity and of the abundance of CSCs.

Renewal of seasonally anoxic Saanich Inlet is temporally and spatially dynamic

Injection of oxygenated water into anoxic basins sets off a cascade of biogeochemical reactions and ecosystem shifts. The dynamic nature of these events can create spatial variability in the resulting water mass that strongly affects subsequent observations. Their irregularity can also make their prediction for experiment planning challenging. Our study focuses on Saanich Inlet, one of the most accessible and well-studied anoxic basins in the world. In the late summer and early fall, dense water can cross the sill into this fjord, in discrete events, bringing oxygen and nitrate to the deep waters of the inlet. We assess the potential strength of these renewal events using density measured at a bottom mooring on the sill. We find that the occurrence and potential strength of renewals is primarily controlled by tidal current speeds, which can be well predicted. However, the intensity of coastal upwelling, which brings dense water into the estuarine system, plays a significant secondary control, reducing predictability. We also demonstrate that renewals do not result in a homogeneous water mass filling the deep inlet. Instead, high frequency measurements from a profiling mooring in the centre of the inlet reveal that different densities intruding over the several-day renewal period create a complex layering of waters containing different proportions of new oxic and old anoxic waters. Finally, we show that not every instance of high density water observed over the sill results in flushing of the deepest waters inside the inlet. We hypothesize that each renewal improves the chance of a subsequent renewal in the same season by reducing the density contrast between waters entering and already inside the inlet. Consideration of the temporal and spatial complexity of these renewal dynamics is necessary to support studies using Saanich Inlet as a natural laboratory for exploring oxygen deficient systems.

Radiological features characterising indeterminate testes masses: a systematic review and meta-analysis.

The use of scrotal ultrasonography (SUS) has increased the detection rate of indeterminate testicular masses. Defining radiological characteristics that identify malignancy may reduce the number of men undergoing unnecessary radical orchidectomy. To define which SUS or scrotal magnetic resonance imaging (MRI) characteristics can predict benign or malignant disease in pre- or post-pubertal males with indeterminate testicular masses. This systematic review was conducted in accordance with Cochrane Collaboration guidance. Medline, Embase, Cochrane controlled trials and systematic reviews databases were searched from (1970 to 26 March 2021). Benign and malignant masses were classified using the reported reference test: i.e., histopathology, or 12 months progression-free radiological surveillance. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool (QUADAS-2). A total of 32 studies were identified, including 1692 masses of which 28 studies and 1550 masses reported SUS features, four studies and 142 masses reported MRI features. Meta-analysis of different SUS (B-mode) values in post-pubertal men demonstrated that a size of ≤0.5 cm had a significantly lower odds ratio (OR) of malignancy compared to masses of >0.5 cm (P < 0.001). Comparison of masses of 0.6-1.0 cm and masses of >1.5 cm also demonstrated a significantly lower OR of malignancy (P = 0.04). There was no significant difference between masses of 0.6-1.0 and 1.1-1.5 cm. SUS in post-pubertal men also had a statistically significantly lower OR of malignancy for heterogenous masses vs homogenous masses (P = 0.04), hyperechogenic vs hypoechogenic masses (P < 0.01), normal vs increased enhancement (P < 0.01), and peripheral vs central vascularity (P < 0.01), respectively. There were limited data on pre-pubertal SUS, pre-pubertal MRI and post-pubertal MRI. This meta-analysis identifies radiological characteristics that have a lower OR of malignancy and may be of value in the management of the indeterminate testis mass.

Review of Redox Potential Control Options for Molten Salt Reactors

Redox potential control is a fundamental requirement to minimize corrosion of metals in neutron irradiated molten salts, including fission reactor fuel, fission reactor coolant, and fusion reactor blanket. In this presentation, the focus will be placed upon metallic redox buffers—including beryllium, zirconium, and lithium. The study of beryllium for this function spans several decades and includes use in the Molten Salt Reactor Experiment (MSRE) in addition to proposed use in a fusion blanket. A fascinating aspect of this subject is the phase behavior of the metallic redox buffer. Evidence has been published that some of the metals—including beryllium and lithium actually dissolve into their host salts in the zero oxidation state. This provides the capability for a fast, homogenous reaction sans mass transfer limits. But redox buffering has also been reported from the reaction of molten salt with zirconium metal rods. It is proposed that these reactions can be categorized as either short range (homogenous) or long range (electrochemical cell) electronically mediated reactions. Data on metal solubility, electrochemical measurements, and corrosion control will be presented from the MSRE to very recent work in support of the Versatile Test Reactor. Open questions will be posed with the intention of encouraging the audience to propose new theories and experiments to test those theories.

S3613 Gastric Spindle Cell Leiomyosarcoma Is Associated With Chronic Helicobacter pylori Infection

Introduction: Chronic Helicobacter pylori (HP) infection has been shown to be strongly associated with development of gastric malignancies, mostly gastric adenocarcinomas and lymphomas. We present a case of primary gastric leiomyosarcoma in a patient with persistent epigastric pain and HP infection. Case Description/Methods: A 59-year-old female presented to clinic with persistent, postprandial epigastric pain. Cardiopulmonary workup was negative. She had a history of esophageal leiomyoma resected endoscopically with negative margins 10 years ago. She was treated in the past for HP infection but never had repeat testing to confirm eradication. Abdominal computed tomography showed focal hepatic infiltration. She was advised to have a repeat upper endoscopy for surveillance but was lost to follow-up due to psychiatric comorbidities. She presented 6 years later with epigastric pain. Repeat CT abdomen showed a new 2.8 cm hypoattenuating lesion in the lesser curvature of the stomach. Patient did not follow up due to psychosocial issues. Two years later, she returned to clinic for epigastric pain and underwent repeat upper endoscopy and endoscopic ultrasound (EUS) with fine needle aspiration (FNA). EGD showed sub-gastric nodule attached gastric wall, about 30 mm in maximal dimension and gastric biopsy confirmed active HP infection. The EUS showed a 31.7x23.5 mm hypoechoic homogeneous gastric mass along the lesser gastric curvature. Cytology showed cellular spindle cell neoplasia with myogenic differentiation concerning for possible leiomyoma or leiomyosarcoma. Abdominal magnetic resonance imaging and chest computed tomography revealed no evidence of abdominal or thoracic metastasis. Subsequently, partial underwent sleeve gastrectomy. Pathology revealed Grade 1 myxoid leiomyosarcoma with negative margins. (Figure) Discussion: Prior studies demonstrated associations between HP infection and gastric malignancies - typically gastric adenocarcinoma or lymphomas. Few studies investigated the relationship between HP infection and gastric leiomyosarcomas.4,5 Importantly, this patient never had clearance of HP infection and may have allowed a leiomyosarcoma to develop. It is imperative that clinicians confirm eradication of HP infection given risk of leiomyosarcoma development in addition to other malignancies HP infections are known to cause.Figure 1.: Endoscopic and histologic examination of gastric leiomyosarcoma. (A) Endoscopic ultrasound visualization demonstrating tumor within lesser curvature of stomach. (B) Upper endoscopy revealing tumor approximately 4 cm from gastroesophageal junction. (C) Hematoxylin and eosin (H&E) stain of gastric tumor biopsy demonstrating spindle cell proliferation in a myxoid background with significant nuclear atypia and pleomorphism consistent with myxoid leiomyosarcoma. Magnification x400. (D) Immunohistochemical staining of gastric lesion biopsy demonstrating strong immunoreactivity to desmin. Not shown are positive stains for smooth muscle actin (SMA) as well as negative stains for Cytokeratin AE1/AE3, Myogenin, MyoD1, DOG-1, CD117, S100, SOX10, CD34, ALK-1 and ER. Positive and negative controls stained appropriately but are not included.

S1744 Idiopathic Non-Caseating Pancreatic Granuloma Mimicking Neuroendocrine Tumor: A Challenging Diagnostic Dilemma

Introduction: Pancreatic granuloma is rare. Caseating granuloma is usually caused by tuberculosis, while non-caseating granuloma is mainly secondary to systemic diseases such as sarcoidosis, rheumatoid arthritis, fungal infection, and Crohn’s disease. Idiopathic etiology can present a diagnostic challenge, requiring further investigation to differentiate it from malignancy. We present an interesting case of a patient who presented with a concern for a neuroendocrine tumor before diagnosing idiopathic non-caseating pancreatic granuloma. Case Description/Methods: A 75-year-old female presented with left upper quadrant pain, chronic diarrhea, and palpitations. The physical exam was unremarkable. Workup was significant for elevated serum chromogranin 3,123 ng/ml, with mildly elevated urine metanephrines. Magnetic resonance imaging showed a stable 2.5 cm cystic lesion in the tail of the pancreas communicating with the main pancreatic duct and hypointense area in the tail. 68Ga DOTATATE scan was negative for neuroendocrine tumor. Endoscopic ultrasound showed a multi-cystic lesion in the tail of the pancreas with thick septations consistent with branch-duct intrapapillary mucinous neoplasm (BD-IPMN), and a 2.7 cm homogenous well-defined hypoechoic area in the tail of pancreas along with multiple enlarged peripancreatic lymph nodes (Figure). Fine needle biopsy showed multiple non-caseating granulomas with benign pancreatic and lymphoid tissue. There was no evidence of malignancy, and stains for acid-fast bacilli, FITE stain, and fungal cultures were negative. A benign idiopathic etiology was concluded. At the 6-months follow-up, the patient was doing well. Discussion: Non-caseating pancreatic granuloma has been described in a few case reports. Sarcoidosis was the most common cause, followed by rheumatoid arthritis and Crohn’s disease. Other cases were associated with granulomatosis with polyangiitis (formerly Wegener's granulomatosis), xanthogranulomatous disease, insulin-dependent diabetes mellitus, or foreign body (Talc). Patients may present with epigastric pain, sometimes associated with weight loss, jaundice, fever, or nausea. Further workup and sampling, or even surgery, might be necessary before reaching a solid diagnosis and ruling out malignancy. Therefore, it is essential to rule out other etiologies before confirming the diagnosis of idiopathic pancreatic non-caseating granuloma.Figure 1.: Endoscopic ultrasound (EUS) showing a homogenous & well-defined hypoechoic mass in the tail of the pancreas, measuring 11 x 27 mm.

Intrathoracic hepatic liver as a cause of chronic dyspnea and thoracic pain

The presentation of ectopic supradiaphragmatic liver tissue is remarkably rare. We present the case of a 40-y-o female patient. With 6-mo of dyspnea with chest and abdominal pain. Computed tomography revealed a well-circumscribed homogenous mass. A thoracoscopic approach revealed an intrathoracic ectopic hepatic parenchyma.