Physical Expansion Research Articles

Expansion microscopy applied to mono- and dual-species biofilms

Expansion microscopy (ExM) is a new super-resolution technique based on embedding the biological sample within a hydrogel and its physical expansion after swelling. This allows increasing its size by several times while preserving its structural details. Applied to prokaryotic cells, ExM requires digestion steps for efficient expansion as bacteria are surrounded by a rigid cell wall. Furthermore, bacteria can live in social groups forming biofilms, where cells are protected from environmental stresses by a self-produced matrix. The extracellular matrix represents an additional impenetrable barrier for ExM. Here we optimize the current protocols of ExM and apply them to mono- and dual-species biofilms formed by clinical isolates of Limosilactobacillus reuteri, Enterococcus faecalis, Serratia marcescens and Staphylococcus aureus. Using scanning electron microscopy for comparison, our results demonstrate that embedded bacteria expanded 3-fold. Moreover, ExM allowed visualizing the three-dimensional architecture of the biofilm and identifying the distribution of different microbial species and their interactions. We also detected the presence of the extracellular matrix after expansion with a specific stain of the polysaccharide component. The potential applications of ExM in biofilms will improve our understanding of these complex communities and have far-reaching implications for industrial and clinical research.

Urban Growth and Transformation of Port City – A Case of Kochi

In the year 1109 AD, the princely state of Cochin was established, marking the beginning of Kochi's historical journey. Over the centuries, Kochi has undergone significant metamorphosis and transformation, experiencing changes in its historical narrative, spatial layout, and environmental context. Particularly noteworthy is Fort Kochi, characterized by its charming ambience and colonial buildings that vividly narrate the tales of centuries-old cultural and commercial interactions with Western colonial powers. This area has left a lasting impression, contributing to Kochi's identity as the commercial capital of Kerala. Studying Kochi becomes a means to comprehend the city's growth patterns and its physical expansion over time. The evolution of Kochi reflects not only its historical roots but also the dynamic shifts in its spatial and environmental dynamics, providing insights into the multifaceted development of this significant urban centre. Fuelled by rapid urbanization and an influx of entrepreneurs, Kochi has emerged as the thriving commercial epicentre of Kerala. Key Words: Kochi, Periyar River, Urbanization, Cosmopolitan Industrial Parks, Economic Landscape

Mechanism of strength deterioration of red sandstone on reservoir bank slopes under the action of dry–wet cycles

To investigate the micro-scale mechanism of strength deterioration under different times of dry–wet cycles, laboratory tests of physical properties, triaxial compression, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were conducted on red sandstone on reservoir bank slopes. The research results showed that when the 5th dry–wet cycle ended, the dry mass and peak strength started to rapidly decline, while the porosity and saturated mass increased rapidly. In general, all of these behaviours become relatively stable when the number of cycles increased. Similarly, cohesion and internal friction angle changed most significantly from 0 to 10 cycles and then became stable. In addition, the physical expansion of the adsorbed water film and the dissolution and expansion of mineral particles increased the number of internal microcracks and pores and the porosity and saturated mass of the sample. In addition, the pore fluid effect and fracture flow effect made the microcracks in the red sandstone grow and connect; thus, the peak strength of the sample decreased. Moreover, during the dry–wet cycles, the change in the relative content of mineral particles and the pore fluid effect weakened the clay cementation, and then the dry mass and cohesion of the samples decreased. The research reported in this paper will play a very significant role in the scientific analysis of slope stability in the Three Gorges Reservoir area.

Exiting Inflation with a Smooth Scale Factor

The expectation that the physical expansion of space occurs smoothly may be expressed mathematically as a requirement for continuity in the time derivative of the metric scale factor of the Friedmann–Robertson–Walker cosmology. We explore the consequences of imposing such a smoothness requirement, examining the forms of possible interpolating functions between the end of inflation and subsequent radiation- or matter-dominated eras, using a straightforward geometric model of the interpolating behavior. We quantify the magnitude of the cusp found in a direct transition from the end of slow-roll inflation to the subsequent era, analyze the validity of several smooth interpolator candidates, and investigate equation-of-state and thermodynamic constraints. We find an order-of-magnitude increase in the size of the universe at the end of the transition to a single-component radiation or matter era. We also evaluate the interpolating functions in terms of the standard theory of preheating and determine the effect on the number of bosons produced.

Identification of immune-related candidate biomarkers in plasma of patients with sporadic vestibular schwannoma.

Vestibular schwannoma (VS) is an intracranial tumor arising from neoplastic Schwann cells and typically presenting with hearing loss. The traditional belief that hearing deficit is caused by physical expansion of the VS, compressing the auditory nerve, does not explain the common clinical finding that patients with small tumors can have profound hearing loss, suggesting that tumor-secreted factors could influence hearing ability in VS patients. We conducted profiling of patients' plasma for 66 immune-related factors in patients with sporadic VS (N > 170) and identified and validated candidate biomarkers associated with tumor size (S100B) and hearing (MCP-3). We further identified a nine-biomarker panel (TNR-R2, MIF, CD30, MCP-3, IL-2R, BLC, TWEAK, eotaxin, and S100B) with outstanding discriminatory ability for VS. These findings revealed possible therapeutic targets for VS, providing a unique diagnostic tool that may predict hearing change and tumor growth in VS patients, and may inform the timing of tumor resection to preserve hearing.

Effect of crystalline admixture and superabsorbent polymer on the self-healing and mechanical properties of basalt fibre mortars

ABSTRACT This study investigated the effects of a crystalline admixture (CA) and superabsorbent polymer (SAP) on the self-healing and mechanical properties of basalt fibre mortars. Uniaxial compression experiments were conducted on basalt fibre mortar specimens to investigate the effects of the two admixtures and different admixture ratios on the strength repair ability of basalt fibre mortar at different maintenance ages after pre-cracking, and microscopic observations of cracks and their healing products were conducted using optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy to verify the experimental results. The results showed that CA has a noticeable advantage in the self-healing of microcracks by producing a dense material through chemical reactions, whereas SAP can effectively fill wider cracks and reduce their width through physical expansion. Compared with CA, SAP had a greater effect on the compressive strength of the basalt fibre mortars. The simultaneous dosing of CA and SAP in appropriate amounts can effectively combine the advantages of CA and SAP to optimise the self-healing effect of basalt fibre mortars, generating self-healing fillers based on calcium silicate and calcium carbonate in the cracks and enhancing the repair strength of basalt fibre mortars with a self-healing rate of 103%.

Physical Expansion Preconditioning Promotes Host-Derived Adipocyte Dedifferentiation and Migration into Fat Grafts in a Murine Model.

The unstable recipient conditions after fat grafting remain an obstacle for tissue volumization. The interaction between fat grafts and recipient sites is not fully understood. The authors hypothesize that recipient-derived adipocytes undergo dedifferentiation and migrate into fat grafts in tissue regeneration. To observe the participation from recipient fat pad, the authors established a recipient adipocyte-tracing model where 0.2 mL of inguinal fat from 10 8-week-old C57BL/6 mice was grafted to 10 tamoxifen-treated AdipoqCre;mT/mG mice. Next, to evaluate the impact of physical force on recipient fat and fat graft, a murine internal expansion model was established by implanting a 1-mL internal expander on the inguinal fat pad of the lineage tracing mice that received fat graft from C57BL/6 mice. Transplanted adipose tissue was collected and analyzed by immunostaining of green fluorescent protein (GFP), tdTomato, perilipin, and CD31. In the observing model, immunostaining revealed that both GFP+ and tdTomato + cells from the recipient fat pad presented in fat grafts. Among the GFP + cells, most of them were perilipin + adipocytes and other perilipin - cells co-expressed octamer-binding transcription factor 4, indicating dedifferentiated adipocytes. In the internal expansion model, internal expansion increased GFP + cells in fat graft. Both octamer-binding transcription factor 4-positive/GFP + (0.23 ± 0.01 versus 0.12 ± 0.04) and perilipin + /GFP + (0.17 ± 0.02 versus 0.06 ± 0.01) cells were increased in the expanded group, compared with control. Host-derived adipocytes participate in fat graft regeneration through migration and dedifferentiation, which could be enhanced by internal expansion to increase fat graft retention rate. Further study using a larger animal model is needed, because this is a murine study. Surgeons are encouraged to use physical expansion preconditioning of the recipient site. Subsequent and multiple fat grafting into the fat layer is encouraged to obtain satisfactory soft-tissue volumization.

An Evaluation of Physical and Socio-Economic Expansion of Bankura Municipality

Urbanization can be viewed as a significant socioeconomic change process that is mostly brought on by the population increase of towns. However, based on a wide range of geographical circumstances, the nature and dimensions of urbanisation and urban development are found to differ across the micro-level of the Bankura district. With this context, an analysis of the spatiotemporal variance in urbanisation patterns in the Bankura Municipality is attempted in this study, along with an examination of its effects on socioeconomic, infrastructure, and demographic traits. Ward-wise socio-economic information have been collected from the Bankura Municipality. All these data have been processed and integrated into GIS platform to measure spatial variation of urban landscape. Results showed that Wards 11 and 22 contained a sizable portion of the population. The population was found in Wards 7, 10, 15, and 19 in a moderate amount. The central ward of the town, number 2, had a very high literacy rate of 80.81%, while number 19, in the southwest, had the lowest literacy rate at 44.87%. The central area of the city is where the majority of the government buildings are located. The eastern region of the city was where the general business centres could be found. Most of the educational centres (college and school) were located in the central and western part.

Expansion microscopy in honeybee brains for high-resolution neuroanatomical analyses in social insects

The diffraction limit of light microscopy poses a problem that is frequently faced in structural analyses of social insect brains. With the introduction of expansion microscopy (ExM), a tool became available to overcome this limitation by isotropic physical expansion of preserved specimens. Our analyses focus on synaptic microcircuits (microglomeruli, MG) in the mushroom body (MB) of social insects, high-order brain centers for sensory integration, learning, and memory. MG undergo significant structural reorganizations with age, sensory experience, and during long-term memory formation. However, the changes in subcellular architecture involved in this plasticity have only partially been accessed yet. Using the western honeybee Apis mellifera as an experimental model, we established ExM for the first time in a social insect species and applied it to investigate plasticity in synaptic microcircuits within MG of the MB calyces. Using combinations of antibody staining and neuronal tracing, we demonstrate that this technique enables quantitative and qualitative analyses of structural neuronal plasticity at high resolution in a social insect brain.

Landscape multifunctionality and dynamic aspects of ‘Jefore’ in the Western Gurageland, Central-South Ethiopia

Cultural landscapes are living evidence of human-environment interactions and patterns of living. This research explores Gurage landscapes' multifunctional and dynamic aspects, mainly Jefore. The study employed an ethnographic research design, and data were generated from multiple sites and sources. Research sites were purposefully selected based on prior knowledge and socio-ecological parameters. Landscape multifunctionality and phenomenological approaches were used to understand landscape's human-environment interactions. According to the findings, Jefore is a well-structured, managed indigenous road network serving public and private roles with a width of 24–84 m and a length of ½ up to 20 km beyond the road network. Jefore remains evidence of human-environment interaction frameworks for living and socio-cultural and ecosystem services as well as phenomenological experiences and associations. As a public landscape, Jefore promotes and maintains village social networks, cultural practices, livelihoods, well-being, and socio-ecological resources integration. It regulates agroforestry practices, optimises resource utilisation, and allows home garden productivity. However, Jefore's socio-ecological landscape identity, landscape multifunctionality, and phenomenological associations are affected by land use and land cover changes, unplanned physical infrastructures expansion, and socio-ecological values crackdown. Largely, Jefore dynamics affected prior landscape designations, socio-cultural and ecological provisions, and long-established sustainable human-environment interactions. Thus, to maintain Jefore's landscape identities and sustainability, micro and macro landscape interventions need to respect and recognize its socio-ecological essence and multifunctionality.

The Impacts of Peri-Urban Expansion on Municipal and Ecosystem Services: Experiences from Makhado Biaba Town, South Africa

The sub-Saharan cities are growing and changing due to immigration and modernization. One of the consequences of the current urbanization is that an increasing number of families residing in peri-urban areas of small rural towns lack access to basic municipal and ecosystem services. The purpose of the paper is to demonstrate the impacts of peri-urban expansion on municipal services provided by the governments and on ecosystems services through a case study of a small rural town called Makhado Biaba in Limpopo Province of South Africa. Makhado Biaba has been experiencing incessant rapid physical expansion over the years. Such spatial expansion into the peri-urban zone impacts the provision of municipal services such as water, electricity, sewerage, and refuse collection. In 2020, an exploratory mixed-methods study of some anthropocentric and ecosystem changes in Makhado Biaba Local Municipality in northeast South Africa was executed. Land use was mapped for the time period of 1990–2020, data were gathered through a household questionnaire in six villages, and interviews were held with municipal officials. Among others, the study showed that several municipal services are available in the peri-urban villages of Makhado Biaba Town despite the distant locations outside the urban core. However, services are not uniformly distributed due to that new peri-urban developments that are leapfrogging into vacant land without supporting infrastructure. The pace of the municipality in providing the necessary municipal services such as water and energy supply, as well as sanitation and refuse removal, is lagging behind the development of new and unplanned housing areas. The findings bring about information about the suburban livelihoods and how the administration of the peri-urban areas can respond to the needs of the inhabitants as well as to future challenges. For instance, to facilitate local development, recurrent and well-structured citizen dialogs with local groups to identify delivery failures are strongly recommended. In addition, the impact on ecosystem services by the city development and land use change stresses the need for guided urban development and expansion and also settlement upgrading programs in peri-urban zones to limit the bad effect on ecosystem services.

Effect of mineralogical variations on physico-mechanical and thermal properties of granitic rocks

The present study aims to explain the geochemical and mineralogical details of the granitic rock types in Gabal EL-Faliq area, South Eastern Desert of Egypt, in relation to geotechnical engineering and their suitability as dimension stones. The objective of the current research was achieved through two steps; the first step involved geological studies such as the petrographic, geochemical, and mineralogical investigations. The second and applicable step involved the geotechnical assessment of the studied rocks by measuring their engineering properties such as physical, mechanical, and thermal expansion properties. The petrographic investigation revealed that the studied granitic rocks are divided into two main classes: (1) gneissose granites (Biotite–Perthite) of medium to fine-grained size and (2) alkali-feldspar granites of coarse to medium-grained size. Mineralogically, the studied rocks are composed mainly of albite, orthoclase and quartz in varying proportions, along with some accessory minerals such as apatite and rutile in addition to some minor quantities of iron-group minerals such as hematite and ilmenite. The engineering properties showed that the maximum water absorption and apparent porosity values are 0.34% and 0.77%, respectively, while the minimum bulk density is 2604.03 kg/m3. The compressive strength ranges from 999.68 to 2469.10 kg/cm2, while the abrasion resistance varies from 29.67 to 54.64 Ha. The increase in albite content led to an increase in water absorption while a decrease in bulk density and compressive strength. The increase in the grain size led to an increase in apparent porosity and a decrease in mechanical properties. A Great variation in the expansion coefficient as well as the length change, occurs under changes in temperature, mineral composition, and physical properties. The increase in heating temperatures caused an insignificant increase in linear thermal expansion with a maximum value of 0.0385% at 100 °C. These results indicated the suitability of the studied granites as dimension stones for use in indoor and outdoor decorative purposes (cladding/paving) under variable temperature conditions.

Is Ecumenopolis Materializing? The Role of Transportation and Communication Networks

Of the many theories put forward for the future of urbanism and urbanization, the concepts of Eperopolis (the continent city) and Ecumenopolis (the universal city) that were put forward by the late architect planner Constantinos Doxiadis and his Ekistics theory in the 1950s and ‘60s, stand out as the most impressive and visionary. Panayis Psomopoulos, Doxiadis’ close associate and well-known architect planner of the Ekistics group, continued and developed further these concepts and publicized strongly through the Ekistics Journal which he managed as editor-in-chief until his passing away in 2017. This paper – conceived and written as a tribute to Panayis Psomopoulos - looks at the global trends of urbanization today and considers the role of transport and communication networks in its future development. It also tries to assess the degree to which the visions of Eperopolis and Ecumenopolis are materializing in the face of modern megacities and urban sprawl in all continents and how transport, communications and supply chain networks affect this process. Its findings support the view that Eperopolises are already materializing in some continents, most notably in Europe in the face of the central European urban cluster between Paris, London, Amsterdam and the Rhine/Ruhr area. Transport and communications networks provide “global connectivity” that acts both as the context (within which urban form develops) as well as the catalyst that plays a key role in limiting the further physical expansion of megacity clusters and braking the connection between urban development and space expansion. By providing efficient global “connectivity”, the future Transport and communication networks are seen as the main catalyst that will bring about materialization of the “universal city”, Ecumenopolis, through the virtual linking of all socio-economic activities in today’s mega-urban areas in all continents.

Toward automated infrared spectral analysis in community drug checking.

The body of knowledge surrounding infrared spectral analysis of drug mixtures continues to grow alongside the physical expansion of drug checking services. Technicians trained in the analysis of spectroscopic data are essential for reasons that go beyond the accuracy of the analytical results. Significant barriers faced by people who use drugs in engaging with drug checking services include the speed and accuracy of the results, and the availability and accessibility of the service. These barriers can be overcome by the automation of interpretations. A random forest model for the detection of two compounds, MDA and fluorofentanyl, was trained and optimized with drug samples acquired at a community drug checking site. This resulted in a 79% true positive and 100% true negative rate for MDA, and 61% true positive and 97% true negative rate for fluorofentanyl. The trained models were applied to selected drug samples to demonstrate a proposed workflow for interpreting and validating model predictions. The detection of MDA was demonstrated on three mixtures: (1) MDMA and MDA, (2) MDA and dimethylsulfone, and (3) fentanyl, etizolam, and benzocaine. The classification of fluorofentanyl was applied to a drug mixture containing fentanyl, fluorofentanyl, 4-anilino-N-phenethylpiperidine, caffeine, and mannitol. Feature importance was calculated using shapely additive explanations to better explain the model predictions and k-nearest neighbors was used for visual comparison to labelled training data. This is a step toward building appropriate trust in computer-assisted interpretations in order to promote their use in a harm reduction context.

Nanoscale imaging of tumor cell exosomes by expansion single molecule localization microscopy (ExSMLM)

Tumor cell exosomes play a very important role in the process of tumor cell proliferation and metastasis. However, due to the nanoscale size and high heterogeneity of exosomes, in-depth understanding of their appearance and biological characteristics is still lacking. Expansion microscopy (ExM) is a method that embeds biological samples in a swellable gel to physically magnify the samples to improve the imaging resolution. Before the emergence of ExM, scientists had invented several super-resolution imaging techniques that could break the diffraction limit. Among them, single molecule localization microscopy (SMLM) usually has the best spatial resolution (20–50 nm). However, considering the small size of exosomes (30–150 nm), the resolution of SMLM is still not high enough for detailed imaging of exosomes. Hence, we propose a tumor cell exosomes imaging method that combines ExM and SMLM (i.e. Expansion SMLM, denoted as ExSMLM), which can realize the expansion and super-resolution imaging of tumor cell exosomes. In this technique, immunofluorescence was first performed to fluorescently label the protein markers on the exosomes, then the exosomes were polymerized into a swellable polyelectrolyte gel. The electrolytic nature of the gel made the fluorescently labeled exosomes undergo isotropic linear physical expansion. The expansion factor obtained in the experiment was about 4.6. Finally, SMLM imaging of the expanded exosomes was performed. Owing to the improved resolution of ExSMLM, nanoscale substructures of closely packed proteins were observed on single exosomes, which has never been achieved before. With such a high resolution, ExSMLM would have a great potential in detailed investigation of exosomes and exosome-related biological processes.

Visualization of <i>Escherichia coli</i> Single Cells in the State of SOS Response Using Expansion Microscopy

Expansion microscopy (ExM) is a sample preparation method that allows to achieve improved visualization of structures due to the physical expansion of the sample. This method is used in combination with traditional light microscopy and allows, without the use of complex technical devices typical for super-resolution microscopy, to achieve visualization of biological structures with higher resolution. Unlike the methods of super-resolution microscopy, expansion microscopy does not make it possible to overcome the diffraction limit; however, the observed effect can be considered equivalent to an increase in the spatial resolution. The relative simplicity of the method and the undemanding nature of the microscope used have made expansion microscopy a fairly popular method to visualize various biological structures last time. This paper describes the use of expansion microscopy to visualize DNA and structures formed by the FtsZ protein in Escherichia coli cells during the SOS response. The results of the work confirm the previously obtained data that the FtsZ protein in cells in the state of the SOS response is unevenly distributed. The protocol used in this work for visualization of E. coli cells preliminarily fixed on the glass surface using the expansion microscopy method can be used in the future to study the internal structures of other cells, both bacterial and eukaryotic.

Spatio-Temporal Analysis of Land Use Change in Uyo Urban, Akwa Ibom State, Nigeria

The increasing population size of cities and the physical expansion of the built-up area beyond the city limits as well as rising demand for more land for various purposes induce changes in urban land-use. This study therefore evaluates the spatio-temporal changes of land uses in Uyo urban. The study utilizes Geographic Information System (GIS); where land use maps of Uyo were produced from Landsat ETM imagery of 2003, 2012 and 2021 using Erdas imagine and ArcGIS softwares. Post classification and change detection analysis for the three years was used to depict changes in identified land uses. The results indicate that in 2003 agricultural land use occupied an area of 37.307 sq.km while residential land use occupied an area of 50.494 sq.km. In 2012, agricultural land use reduced to 25.347 sq.km while residential land use increased to 62.879 sq.km. Furthermore, by 2021, agricultural lands use further indicated drastic reduction occupying an area of 6.207 sq.km while residential land use indicated remarkable increase to 73.469 sq.km. Between 2003 and 2012, residential land uses increased by 8.88 sq.km translating into 15.4 per cent within 10 years and 1.5 per cent per annum; whereas agricultural land use decreased annually by -2.5 per cent. Other land uses such as institutional, commercial and transportation land uses also increased, while forest and water bodies also decreased within the years. It is recommended that periodic monitoring of the land use should be encouraged to ascertain the pattern of changes in order to curtail negative impacts on the environment.

Aptamer-based expansion microscopy platform enables signal-amplified imaging of dendritic spines

Super-resolution imaging of dendritic spines (DS) can provide valuable information for mechanistic studies related to synaptic physiology and neural plasticity, but challenged by their small dimension (50–200 nm) below the spatial resolution of conventional optical microscopes. In this work, by combining the molecular recognition specificity of aptamer with high programmability of DNA nanotechnology, we developed an expansion microscopy (ExM) platform for imaging DS with enhanced spatial resolution and amplified signal output. Our results demonstrated that the aptamer probe could specifically bind to DS of primary hippocampal neurons. With physical expansion, the DS structure could be effectively enlarged by 4–5 folds, leading to the generation of more structural information. Meantime, the aptamer binding signal could be readily amplified by the introduction of DNA signal amplification strategy, overcoming the drawback of fluorescence dilution during the ExM treatment. This platform enabled evaluation of ischemia-induced early stroke based on the morphological change of DS, highlighting a promising avenue for studying nanoscale structures in biological systems.

Abstract 3664: Mechanism for bone marrow failure differs between acute myeloid and lymphoid leukemia

Abstract Acute lymphoid leukemia (ALL) and acute myeloid leukemia (AML) are aggressive forms of blood cancer that impair normal hematopoiesis and are typically associated with bone marrow (BM) failure, reflected by peripheral blood pancytopenia. While BM failure is thought to be mediated by the loss of hematopoietic stem and progenitor cells (HSPCs) due to leukemic expansion, with leukemic cells “crowding out” normal HSPCs, the mechanisms underlying this process remain unclear. To elucidate these mechanisms, we examined the effects of AML or ALL on residual normal or wild type (WT) hematopoiesis. The 961C cell line is an AML cell line derived from a NUP98-PH23 (NP23) transgenic mouse, and the T259 cell line is a B cell precursor ALL (BCP ALL) cell line also derived from an NP23 mouse. AML and BCP ALL were generated by transplantation of 961C or T259 cell lines into congenic recipients without cytotoxic conditioning. The use of congenic mice allowed engraftment of immunocompetent mice, and the lack of cytotoxic conditioning prevented damage to the BM microenvironment. Mice with AML demonstrated severe anemia, thrombocytopenia, and depletion of HSPCs, along with a marked reduction of total BM cellularity (WT + AML cells), suggesting that BM suppression was not due to a physical “crowding” mechanism. Instead, BM suppression in the absence of BM replacement with myeloblasts suggested that hematopoiesis may be inhibited by a factor secreted by the AML blasts. The inflammatory cytokines TNF-A and IL-6 were markedly increased in the peripheral blood of mice with AML, suggesting these were candidates for a factor responsible for decreased cellularity and pancytopenia. In contrast, mice with BCP ALL demonstrated normal hemoglobin and leukocyte counts, even with significant ALL engraftment. The loss of WT hematopoietic cells in the BM was equivalent to the gain of leukemic cells in the BM, and the total number of leukemic cells in mice with BCP ALL was 14-fold higher than the number of leukemic cells in mice with AML. Of note, the spleen of mice with BCP ALL displayed a 100x increase in WT HSPCs compared to non-transplanted mice with healthy BM. These findings suggest that BCP ALL depletes WT HSPCs in the BM through a physical expansion mechanism. WT splenic HSPCs from mice with AML were shown to have normal numbers of functional hematopoietic stem cells via a limiting dilution assay. In addition, WT HSPCs harvested from mice with BCP ALL generated similar numbers and types of colonies in vitro compared to WT HSPC harvested from non-leukemic mice. Both experiments suggest that neither BCP ALL nor AML induced a permanent change in the functionality of WT HSPCs. In conclusion, our results suggest that AML induces BM failure independent of leukemic burden, possibly via a secreted cytokine, whereas BCP ALL induces BM failure through physical expansion that replaces WT HSPCS with leukemic cells. Citation Format: Ryan Matthew Bertoli, Peter D. Aplan, Yang Jo Chung. Mechanism for bone marrow failure differs between acute myeloid and lymphoid leukemia. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3664.

Effect of treated clinoptilolite zeolite on alkali-silica reaction

The reactive aggregates can cause a volumetric expansion in the concrete leading to cracking and spalling due to alkali-silica reaction (ASR). The use of natural zeolite as the supplementary cementitious material can reduce the expansion due to ASR by providing physical space for the ASR gel along with the adsorption of alkalis through the cation exchange. However, the rate of reduction in expansion may sometimes not be satisfactory due to the slow rate of cation exchange along with other factors. Therefore, the present study investigates three different treatment techniques (calcination, milling, and chemical pre-treatment) on clinoptilolite zeolite to obtain an optimal method for reducing the expansion due to ASR. Calcination was done at 400 °C for 3 h to increase the amorphous contents, while milling was done for 3 h to increase the specific surface area of zeolite particles leading to increasing pozzolanic activities. The chemical pre-treatment was accomplished with a 1 M Ca(OH)2 solution to largely remove any existing sodium or potassium ions via cation exchange. To observe the physical expansion due to ASR, mortar bars were prepared with highly reactive cherty sand and up to 20% of both untreated and treated zeolite with the replacement of the portland cement. Results revealed that calcination slightly increased the amorphous contents while milling substantially increased the specific surface area of zeolite particles. The chemical pre-treatment successfully transformed the zeolite into calcium-based clinoptilolite zeolite. Results also revealed that the application of up to 20% untreated, calcined, milled, and chemically treated zeolite reduced the ASR expansion by up to 60%, 40%, 70%, and 42%, respectively, compared to the control sample at 28 days. Overall, among the three different treatment methods, milling was the most effective method to reduce the ASR expansion, while calcined and chemically treated zeolite was less effective than untreated zeolite.