Academic literature on the topic 'HSC'
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Journal articles on the topic "HSC"
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Puzzarini, Cristina. "The HCS∕HSC and HCS+∕HSC+ systems: molecular properties, isomerization, and energetics." Journal of Chemical Physics 123, no. 2 (July 8, 2005): 024313. http://dx.doi.org/10.1063/1.1953367.
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Ropa, James, Scott Cooper, Lindsay Beasley, David M. Markovitz, Hal E. Broxmeyer, and Maegan L. Capitano. "Extracellular DEK Treatment Mimics Hypoxic Blockade of Extra Physiologic Oxygen Stress in Human and Mouse Hematopoietic Cells." Blood 138, Supplement 1 (November 5, 2021): 2152. http://dx.doi.org/10.1182/blood-2021-151171.
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Abstract Hematopoietic stem cell (HSC) and progenitor cell (HPC) self-renewal, proliferation, survival, and function are regulated by extracellular signals from cytokines and chemokines. DEK, a nuclear regulator of chromatin availability, was recently shown to also function as an extracellular protein that regulates HSC and HPC by inducing signaling through the CXC chemokine receptor 2 (CXCR2), enhancing pools of long-term stem cells while decreasing pools of functional HPC [Capitano et al., JCI, 2019, 129(6):2555-70]. Due to differing effects of extracellular (ec)DEK treatment on HSC growth and function compared to the effects on HPC, we hypothesized that DEK differentially regulates HSC compared to HPC. To explore this, we pulse-treated purified human cord blood (CB) CD34+ cells for 18 hours with recombinant human ecDEK protein. We then isolated by flow cytometry stringently immunophenotypically-defined human HSC, multipotent progenitors (MPP), common myeloid progenitors (CMP), and granulocyte-macrophage progenitors (GMP) and performed mRNA-sequencing to profile ecDEK-dependent transcriptomes of these separate populations of HSC/HPC. Interestingly, there are widely different ranges of effects on the transcriptomes of the different isolated HSC/HPC populations. CMP had the most differentially expressed (DE) genes induced by DEK treatment, followed by HSC and MPP, and GMP had relatively few changes, suggesting DEK treatment may primarily affect HSC and earlier HPC. HSC exhibited the strongest magnitude of changes in DE genes. Fast gene set enrichment analysis (FGSEA) revealed that GMP showed upregulation of gene programs associated with leukocyte migration and downregulation of gene programs regulated by MYC, CMP showed upregulation of gene programs associated with myeloid cell development and downregulation of lysine methyltransferase activity, and MPP and HSC both upregulated cytokine signaling responses in response to DEK treatment, though HSC also exhibited a downregulation of genes associated with cell cycle. Despite the identified unique changes upon DEK treatment in these different HSC/HPC populations, we were most interested to discover that all examined cell types demonstrated upregulation of genes associated with hypoxic responses in cells, and a concordant downregulation of genes that are frequently downregulated by hypoxic exposure following DEK treatment. This suggested to us that DEK may stimulate overlapping pathways related to hypoxia responses and/or response to exposure to extra physiologic oxygen. In fact, the effects on HSC and HPC induced by ecDEK is similar with previous work demonstrating that isolating HSC/HPC at 3% O 2 compared to ambient air conditions (~21% O 2) leads to a preserved pool of functional HSC but a lower number of functional HPC, due to a phenomenon termed extracellular physiologic shock/stress (EPHOSS) [Mantel et al., Cell, 2015, 161(7):1553-65]. To explore whether DEK regulates similar stress response pathways that are associated with EPHOSS, we assessed the effects of ecDEK treatment on HSC/HPC isolated at 3% O 2. Mice were treated with DEK in vivo, then bone marrow cells were isolated at 3% O 2 in a hypoxia chamber. Cells were kept at 3% O 2 or split to ambient air to allow equilibration to a higher oxygen tension and then assessed for HSC and functional HPC numbers. In contrast to untreated HSC/HPC isolated at 3% O 2, ecDEK treated cells isolated at 3% O 2 did not exhibit further increases in LT-HSC numbers or decreases in pools of functional HPC over ecDEK treatment alone identified by colony assays. Isolation at 3% O 2 followed by in vitro treatment with DEK showed similar results. This suggests ecDEK may neutralize the effects of EPHOSS by acting on similar gene programs that are induced by ambient air exposure. We also demonstrate that ecDEK prevents the ex vivo apoptosis of CB HSC/HPC populations, again suggesting that ecDEK is preventing the cellular stress associated with ambient air exposure and ex vivo growth, resulting in a preservation of HSC. Taken together, these data show that ecDEK acts as an extracellular signaling protein that prevents cellular stress by activating gene programs that overlap with hypoxia associated gene programs. This has important implications for the role of ecDEK in normal and diseased hematopoiesis, as well as clinical implications wherein ecDEK may be used to mimic the HSC preserving effects of isolation at 3% O 2. Disclosures Markovitz: University of Michigan: Patents & Royalties: H84T BanLec and of the H84T-driven CAR construct.
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Agúndez, M., N. Marcelino, J. Cernicharo, and M. Tafalla. "Detection of interstellar HCS and its metastable isomer HSC: new pieces in the puzzle of sulfur chemistry." Astronomy & Astrophysics 611 (March 2018): L1. http://dx.doi.org/10.1051/0004-6361/201832743.
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We present the first identification in interstellar space of the thioformyl radical (HCS) and its metastable isomer HSC. These species were detected toward the molecular cloud L483 through observations carried out with the IRAM 30 m telescope in the λ3 mm band. We derive beam-averaged column densities of 7 × 1012 cm−2 for HCS and 1.8 × 1011 cm−2 for HSC, which translate into fractional abundances relative to H2 of 2 × 10−10 and 6 × 10−12, respectively. Although the amount of sulfur locked by these radicals is low, their detection allows placing interesting constraints on the chemistry of sulfur in dark clouds. Interestingly, the H2CS/HCS abundance ratio is found to be quite low, ~1, in contrast with the oxygen analog case, in which the H2CO/HCO abundance ratio is around 10 in dark clouds. Moreover, the radical HCS is found to be more abundant than its oxygen analog, HCO. The metastable species HOC, the oxygen analog of HSC, has not yet been observed in space. These observational constraints are compared with the outcome of a recent model of the chemistry of sulfur in dark clouds. The model underestimates the fractional abundance of HCS by at least one order of magnitude, overestimates the H2CS/HCS abundance ratio, and does not provide an abundance prediction for the metastable isomer HSC. These observations should prompt a revision of the chemistry of sulfur in interstellar clouds.
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He, Fang, and Guanping Yao. "Ginsenoside Rg1 as a Potential Regulator of Hematopoietic Stem/Progenitor Cells." Stem Cells International 2021 (December 31, 2021): 1–11. http://dx.doi.org/10.1155/2021/4633270.
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Ginsenoside Rg1 (Rg1), a purified, active component of the root or stem of ginseng, exerts positive effects on mesenchymal stem cells (MSCs). Many recent studies have found that hematopoietic stem cells (HSCs), which can develop into hematopoietic progenitor cells (HPCs) and mature blood cells, are another class of heterogeneous adult stem cells that can be regulated by Rg1. Rg1 can affect HSC proliferation and migration, regulate HSC/HPC differentiation, and alleviate HSC aging, and these findings potentially provide new strategies to improve the HSC homing rate in HSC transplantation and for the treatment of graft-versus-host disease (GVHD) or other HSC/HPC dysplasia-induced diseases. In this review, we used bioinformatics methods, molecular docking verification, and a literature review to systematically explore the possible molecular pharmacological activities of Rg1 through which it regulates HSCs/HPCs.
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Chen, Xiao Bo, Jian Yin, and Wei Min Song. "Autogenous Volume Deformation and Creep Properties Analysis of C60 High Performance Concrete and C60 High Strength Concrete." Advanced Materials Research 639-640 (January 2013): 364–67. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.364.
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Based on engineering practice, autogenous volume deformation and creep properties of C60 high performance concrete(C60 HPC) and C60 high strength concrete(C60 HSC) were evaluated in the study. The results showed that the cement partly-replaced with fly ash could significantly decrease the creep deformation, creep coefficient and creep degree. In comparison with C60 HSC, the creep coefficient and creep degree of C60 HPC were decreased 17.9％and15.8％ in 28 days, 22.9% and 21.0% in 270 days. For C60 HPC and C60 HSC at the same age, autogenous volume deformation of C60 HPC is greater than that of C60 HSC, but they were both less than 80×10-6 , and the autogenous volume deformation was basically completed in 7 days.
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Mailloux, Adam, and Pearlie Epling-Burnette. "Collagen matrix deposition by hepatic stellate cells protects hepatocellular carcinoma from NK-mediated cytotoxicity (P2013)." Journal of Immunology 190, no. 1_Supplement (May 1, 2013): 53.7. http://dx.doi.org/10.4049/jimmunol.190.supp.53.7.
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Abstract Liver fibrosis (LF), a leading risk factor for hepatocellular carcinoma (HCC), is caused by collagen-producing hepatic stellate cells (HSC) activated during chronic inflammation secondary to hepatitis-C infection, or alcohol liver disease (ALD). NK cells promote disease resolution via RAE1-dependant HSC clearance. A defect in NK function by an ill-defined mechanism contributes to a pro-fibrotic response. Using an engineered bioartifical collagen matrix, the expression of inhibitory leukocyte associated IgG-like receptor-1 (LAIR-1) was increased on dividing NK cells and IL-2-induced NK proliferation was inhibited. Thus, we hypothesized that the accumulation of HSC-derived collagen directly inhibits NK activity and protects both HSC and HCC from innate clearance. We found that deposition of native collagen matrix for 72h protected HSCs from NK lysis in Cr51 cytotoxicity assays. A HCC cell line (HEPG2), which produced no collagen when cultured in the absence of HSCs, was susceptible to activated NK killing and was unaffected by collagenase. To test if HSC-derived collagen protects HEPG2 cells, the populations were differentially labeled with ipophilic dyes and co-cultured for 72h for use in flow-based assays. Collagen matrix protected both targets, while collagenase pretreatment restored NK sensitivity. These results suggest that HSC-derived collagen may contribute to NK dysfunction in LF and HCC, and identifies LAIR-1 as a potential mediator of tumor-induced immune suppression.
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Das, Amitava, Uday Shergill, Lokendra Thakur, Sutapa Sinha, Raul Urrutia, Debabrata Mukhopadhyay, and Vijay H. Shah. "Ephrin B2/EphB4 pathway in hepatic stellate cells stimulates Erk-dependent VEGF production and sinusoidal endothelial cell recruitment." American Journal of Physiology-Gastrointestinal and Liver Physiology 298, no. 6 (June 2010): G908—G915. http://dx.doi.org/10.1152/ajpgi.00510.2009.
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Chemotaxis signals between hepatic stellate cells (HSC) and sinusoidal endothelial cells (SEC) maintain hepatic vascular homeostasis and integrity and also regulate changes in sinusoidal structure in response to liver injury. Our prior studies have demonstrated that the bidirectional chemotactic signaling molecules EphrinB2 and EphB4 are expressed in HSC. The aim of our present study was to explore whether and how the EphrinB2/EphB4 system in HSC could promote SEC recruitment, which is essential for sinusoidal structure and remodeling. Stimulation of human HSC (hHSC) with chimeric agonists (2 μg/ml) of either EphrinB2 or EphB4 (EphrinB2 Fc or EphB4 Fc, respectively) significantly increased VEGF mRNA levels in hHSC as assessed by quantitative PCR, with respective small interfering RNAs for EphrinB2 and EphB4 inhibiting this increase ( P < 0.05, n = 3). EphrinB2 agonist-induced increase in VEGF mRNA levels in hHSC was associated with increased phosphorylation of Erk and was significantly blocked by U0126 (20 μM), an inhibitor of MEK, which is a kinase upstream from Erk ( P < 0.05, n = 3). The EphB4 agonist also significantly increased human VEGF promoter activity ( P < 0.05, n = 3) as assessed by promoter reporter luciferase assay in transfected LX2-HSC. This was associated with upregulation of the vasculoprotective transcription factor, Kruppel-like factor 2 (KLF2). In Boyden chamber assays, conditioned media from hHSC stimulated with agonists of EphrinB2 or EphB4 increased SEC chemotaxis in a VEGF-dependent manner, compared with control groups that included basal media with agonists of EphrinB2, EphB4, or HSC-conditioned media from HSC in absence of agonist stimulation ( P < 0.05, n = 3). EphB4 expression was detected in situ within liver sinusoidal vessels of rats after carbon tetrachloride-induced liver injury. In summary, activation of the EphrinB2/EphB4 signaling pathway in HSC promotes chemotaxis of SEC through a pathway that involves Erk, KLF2, and VEGF. These studies identify EphrinB2 or EphB4 as a key intermediary that links HSC signal transduction pathways with angiogenesis and sinusoidal remodeling.
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Calvanese, Vincenzo, Sacha L. Prashad, Mattias Magnusson, and Hanna K. A. Mikkola. "Analysis of Highly Self-Renewing GPI-80+ Human Fetal Hematopoietic Stem Cells Identifies Novel Regulators of Stemness." Blood 124, no. 21 (December 6, 2014): 4314. http://dx.doi.org/10.1182/blood.v124.21.4314.4314.
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Abstract Achievements in pluripotent stem cell and reprogramming strategies provide hope for generating hematopoietic stem cells (HSC) in culture and for obtaining unlimited sources of transplantable cells. To reach this goal, deeper understanding of the regulatory mechanisms that distinguish the self-renewing HSC from non-self-renewing progenitors during human development is required. We analyzed the molecular signature of GPI-80 (VNN-2) expressing human second trimester fetal liver HSPC, the only population that harbors the truly self-renewing fetal HSC. Microarray and RNAseq analysis comparing CD34+CD38-CD90+GPI-80+ HSC to CD34+CD38-CD90+GPI80- HPC demonstrated remarkable molecular similarity of these two functionally distinct populations, including comparable expression of many key transcription factors involved in HSC development and maintenance (e.g. SCL, RUNX1, MLL1, HOXA9, BMI1, GFI1, ETV6 etc.). Nevertheless, this analysis identified a subset of transcriptional regulators uniquely up-regulated in GPI80+ HSC, such as MYCT1, HLF, MLLT3 and HIF3A. These factors were down-regulated in human fetal liver HSPC upon expansion on MSC stroma culture, during which they become compromised in in vivo engraftment ability despite maintaining HSC surface immunophenotype. multipotency and expression of most known HSC regulators. Moreover, these factors were absent or expressed at low levels in human ES cell derived HPC, which can acquire HSC surface phenotype but are unable to self-renew. The expression of MYCT1, MLLT3 and HLF was also enriched in undifferentiated HSPC subset as compared to progenitors in the adult bone marrow, while HIF3a expression was low post-natally. Altogether, these analyses implied strong correlation of the expression of these factors with HSC self-renewal properties. Strikingly, knockdown of MYCT1, HLF, MLLT3 and HIF3A in human fetal liver HSPC using lentiviral shRNA impaired maintenance of undifferentiated HSPC in MSC stroma co-culture, while their inducible overexpression augmented HSPC expansion and prevented their premature exhaustion. Uncovering how these novel HSC regulators protect the highly self-renewing fetal HSC will help define the pre-requisites for establishing and maintaining stemness in developing human HSC, and for generating HSC for therapeutic use. Disclosures No relevant conflicts of interest to declare.
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Butler, John T., Sherif Abdelhamed, Lina Gao, Jeong Lim, Terzah M. Horton, and Peter Kurre. "Leukemic Stress Targets the mTOR Pathway to Suppress Residual HSC in the BM Microenvironment." Blood 134, Supplement_1 (November 13, 2019): 3730. http://dx.doi.org/10.1182/blood-2019-125682.
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The remodeling of the bone marrow (BM) microenvironment that occurs along with the progressive spread of acute myeloid leukemia (AML) cells can be considered a constitutive aspect of leukemogenesis. To date most studies have focused on the functional and in part inflammatory adaptation of stroma, and its potential role in extrinsic chemotherapy resistance. Much less is known about the impact of leukemic stress on residual hematopoietic cells. We previously identified the trafficking of select microRNAs (miRs-) in extracellular vesicles (EVs) between AML cells and hematopoietic progenitor cells (HPC). These studies revealed the mechanism underlying the suppression of HPC function in the AML niche (Hornick, Doron et. al., Science Signaling 2016). Several groups, including ours also noted the relative resistance of residual hematopoietic stem cells (HSC) to elimination from the BM of xenografted animals. In the current study we set out to understand how leukemic stress in the AML xenograft niche shapes HSC fate and function. Using AML cell lines (Molm14, U937, HL60) we established NSG xenografts, systematically tracking peripheral blood AML chimerism to recover murine hematopoietic cells at low or negative tumor burden, and replicating key assays using purified EV for intrafemoral injections. In immunofluorescent studies we initially confirmed the uptake of GFP labeled xenograft-derived EVs across the spectrum of HPC and HSC (KSL/CD150+/CD48-), as well as the successive loss and peripheral displacement of HPCs, and gains in HSC frequency in the leukemic niche. These HSC were found to be enriched for G0 cell cycle status with an increase in phospho- p53, but showed no evidence of apoptosis or senescence. To understand the mechanism underlying their apparent quiescence, we performed in vitro proteomics studies of AML EV exposed HPSC identified downregulation of ribosomal biogenesis pathways. We then confirmed in vivo that residual HSC from AML xenografts experienced a loss of protein synthesis (OPP assay). We next reasoned that deficits in ribosome dysfunction and protein synthesis may reflect deregulation by specific miRNAs highly abundant in AML EV. Here, we had an opportunity to profile EV miRNA from the plasma of 12 unselected AML patients at diagnosis versus 12 control samples, and we confirmed a significant enrichment for specific miRNAs, including miR-1246. Raptor is a component of the mTOR pathway and an annotated target of miR-1246. We demonstrated in a series of experiments that miR-1246 translationally suppresses Raptor and downregulates protein synthesis in residual HSC from AML xenografts. The transfection of synthetic anti-miR1246 sequences on the other hand reversed the effects of AML EV in murine HSC. In aggregate we show that direct crosstalk between AML and hematopoietic cells adds to the adaptive changes that occur in the AML niche. Our experiments suggest a functional significance for EV miRNA that can be detected in AML patient plasma in the regulation of residual BM HSC. More broadly, the mechanisms by which leukemic stress alters hematopoietic function remain underexplored, but our observations suggest that leukemia derived EV contribute to changes in competitive fitness of residual HSC. Disclosures No relevant conflicts of interest to declare.
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Capitano, Maegan L., Scott Cooper, Bin Guo, Xinxin Huang, Carol Sampson, Safa Mohamad, Edward F. Srour, Christie M. Orschell, and Hal E. Broxmeyer. "Collection and Processing of Bone Marrow at 3% Oxygen Significantly Alters the Manifestation of Aged Mouse Hematopoietic Stem Cell Phenotype." Blood 134, Supplement_1 (November 13, 2019): 1202. http://dx.doi.org/10.1182/blood-2019-128642.
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Aging is an inevitable process associated with eventual deterioration of normal physiological functions. Aged hematopoiesis is associated with increased numbers of hematopoietic stem cells (HSC), but with decreased HSC functional activity (e.g. decreased engrafting capability in lethally irradiated mice and a shift in the myeloid:lymphoid bias of the engrafting HSC of the old mice, such that there are more myeloid but fewer lymphoid cells generated from HSC of the old mice). Production of HSC and progenitor (HPC) cells ex vivo is more efficient when cells are cultured in a hypoxic environment of ~ 5% oxygen tension than when cells are grown at ambient air (~21% oxygen). The bone marrow (BM) microenvironment niche that nurtures the survival and production of HSC and HPC and hematopoiesis during adult life is a hypoxic environment (~1-5% oxygen tension) compared to that of ambient air. However, almost all results of studies of young and aged mouse hematopoiesis have been based on numbers and activity of HSC and HPC that have been collected and processed in ambient air. Our recent work evaluating hematopoiesis in BM cells of young adult mice and with human cord blood cells found, through a phenomenon we designated Extra Physiological Oxygen Shock/Stress (EPHOSS), that there is a large loss of HSC with an increase of HPC within minutes of the collection of these cells in ambient air (Mantel et al., Cell, 2015). This led us to reason that perhaps what we know about aging hematopoiesis might not be entirely accurate and that a re-evaluation of aged HSC, HPC, and hematopoiesis was in order. We hypothesized that hematopoiesis in aged (~20-27 months of age) mice may not be as dysregulated as reported but that collection and processing of BM from the aged mice is more sensitive than similar cells from young (~6-16 weeks) mice to EPHOSS-induced events generated by the collection of the cells in ambient air. We evaluated BM from three different mouse strains (CB6, BALB/c, and C57Bl/6) at 20-25 months vs. 6-16 weeks of age, collected/processed in ambient air or hypoxia (3% oxygen). BM from old mice collected/processed under hypoxic conditions exhibited phenotypically increased long-term HSC and common lymphoid progenitor (CLP) numbers and decreased common myeloid progenitor (CMP) and granulocyte-macrophage progenitor (GMP) numbers when compared to old BM collected/processed under ambient air conditions. BM collected from old C57Bl/6 mice under hypoxia had increased engrafting capability more closely matching that of young BM. This was associated with a 3.14-fold increase in the number of competitive repopulating units (representative of functional HSC) in old BM collected under hypoxic conditions compared to old BM collected in ambient air as determined through limiting dilution analysis. The myeloid:lymphoid ratio of old BM collected under hypoxia matched that of young BM collected under air. This was associated with decreased cycling of CFU-GM, BFU-E, and CFU-GEMM in old BM collected/processed in hypoxia. Enhanced numbers/function of old BM HSCs collected in hypoxia is associated with changes in expression of CXCR4 (and HSC homing capability), CCR5, stress protein levels (e.g. HSP40 etc) and ROS (both total and mitochondrial). All of these noted changes demonstrated that the old BM collected/processed under hypoxic conditions more closely resemble functionally young BM. Thus, age-related differences between the HSC/HPC populations are not as drastic as previously reported and reflect the increased sensitivity of hematopoiesis from aged mice to an artificial ambient air collection procedure. Disclosures No relevant conflicts of interest to declare.
Dissertations / Theses on the topic "HSC"
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SCARFÒ, REBECCA. "Precise characterization of hemogenic endothelial cells during human hematopoietic development." Doctoral thesis, Università Vita-Salute San Raffaele, 2022. http://hdl.handle.net/20.500.11768/128259.
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During embryonic development, blood cells emerge from a subset of specialized endothelial cells, named hemogenic endothelium (HE), via a process known as endothelial-to-hematopoietic transition (EHT). HE represents a heterogeneous population found in various anatomical sites, including the yolk sac (YS) and the aorta-gonad-mesonephros (AGM). It comprises cells that differ in developmental potential, thus defining distinct hematopoietic programs. Despite the endothelial descendancy of blood cells is well established, the identity of HE is still debated. A more thorough characterization of HE is therefore essential to guide the efforts to derive this population from human pluripotent stem cells (hPSCs), a critical step to generate therapeutic blood products in vitro. However, current known markers used to isolate HE are insufficient as they also enrich associated arterial cells. To identify specific human HE markers, we performed transcriptomic analysis of 4-5-week-old human embryos, a developmental stage characterized by active EHT. We identified FCGR2B encoding for the Fc receptor CD32, previously associated with other specialized endothelia, as enriched gene in the ACE+CD34+ population that contains HE. Functional ex vivo analyses confirmed that multilineage hematopoietic potential is highly enriched in CD32+ endothelial cells isolated from the AGM and YS of human embryos. In addition, CD32 emerged as selective marker for hPSC-derived HE across different hematopoietic programs. Remarkably, our analyses showed that CD32 specificity for cells with hemogenic potential is superior to other known HE markers in hPSC-derived hematopoietic cultures. These findings provide a simple method for isolating HE from human embryos and hPSCs, allowing its molecular characterization as well as the efficient generation of hematopoietic cells in vitro.Durante lo sviluppo embrionale, le cellule del sangue emergono da un sottoinsieme di cellule endoteliali specializzate, denominate endotelio emogeno (HE), attraverso un processo noto come transizione endoteliale-ematopoietica (EHT). HE è una popolazione eterogenea che si trova in vari siti anatomici, tra cui il sacco vitellino (YS) e l'aorta-gonade-mesonefro (AGM). Comprende cellule che differiscono per il potenziale di sviluppo, definendo così programmi ematopoietici distinti. Nonostante la discendenza endoteliale delle cellule del sangue sia ben consolidata, l'identità di HE è ancora dibattuta. Una caratterizzazione più approfondita di HE è quindi essenziale per guidare gli sforzi nel derivare questa popolazione dalle cellule staminali pluripotenti umane (hPSC), un passaggio fondamentale per generare emoderivati terapeutici in vitro. Tuttavia, gli attuali marcatori noti utilizzati per isolare l'HE non sono sufficienti poiché arricchiscono anche le cellule arteriose associate. Per identificare specifici marcatori HE umani, abbiamo eseguito l'analisi trascrittomica di embrioni umani di 4-5 settimane, una fase di sviluppo caratterizzata da EHT attivo. Abbiamo identificato la codifica FCGR2B per il recettore Fc CD32, precedentemente associato ad altri endoteli specializzati, come gene arricchito nella popolazione ACE+CD34+ che contiene HE. Analisi funzionali ex vivo hanno confermato che il potenziale ematopoietico multilineare è altamente arricchito nelle cellule endoteliali CD32+ isolate dall'AGM e dall'YS di embrioni umani. Inoltre, CD32 è emerso come marcatore selettivo per HE derivato da hPSC in diversi programmi ematopoietici. Sorprendentemente, le nostre analisi hanno mostrato che la specificità del CD32 per le cellule con potenziale emogeno è superiore ad altri marcatori HE noti nelle colture ematopoietiche derivate da hPSC. Questi risultati forniscono un metodo semplice per isolare HE da embrioni umani e hPSC, consentendo la sua caratterizzazione molecolare e la generazione efficiente di cellule ematopoietiche in vitro.
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Stein, Sebastian [Verfasser]. "HSC-Kantenbearbeitung von Blech / Sebastian Stein." Aachen : Shaker, 2010. http://d-nb.info/1081884592/34.
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Zhou, Xuan. "RhoA GTPase Controls Cytokinesis and Programmed Necrosis of Hematopoietic Progenitors." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378197381.
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Meiklejohn, Stuart J. "The role of BMP signalling in HSC ontogeny." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:305597a8-b8cb-42ff-88fd-34b3dd5bf39b.
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The haematopoietic stem cell (HSC) is found in the adult human bone marrow, where it gives rise to all the circulating blood cells throughout adulthood. Understanding the signalling events that programme these cells during development will improve HSC in vitro culture, their generation from embryonic stem cells or induced pluripotent stem cells, and their potential therapeutic application. HSCs bud from the floor of the dorsal aorta and seed the bone marrow via circulation. The precursors to the dorsal aorta and HSCs are called haemangioblasts, which are found in the dorsal lateral plate mesoderm in Xenopus. The knowledge of the location of these precursors allows their programming to be studied in detail during embryonic development. A key pathway implicated in the programming of HSCs is the BMP signalling pathway. Here, using both a small molecule inhibitor and a transgenic Xenopus line, BMP signalling has been inhibited post-gastrulation without perturbing the gross morphology of the embryo. This has shown that BMP signalling is required for HSC programming in the dorsal lateral plate mesoderm via the expression of a critical haematopoietic transcription factor, gata2. Morpholino knockdown of evi3has revealed it to be essential for HSC programming in the dorsal lateral plate mesoderm, where it is required for the expression of gata2. Furthermore, as evi3 is known to bind to the active BMP signalling complex, and as evi3 knockdown phenocopies post-gastrulation BMP inhibition, evi3 appears to be required for BMP signalling to initiate gata2 expression in the DLP. Taken together, the findings presented here demonstrate an essential post-gastrulation role of BMP signalling and Evi3 for programming HSCs in Xenopus.
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SIGHINOLFI, SILVIA. "INTRACELLULAR IRON OVERLOAD AFFECTS HSC METABOLISM BY IMPAIRING MITOCHONDRIAL FITNESS IN β-THALASSEMIA." Doctoral thesis, Università Vita-Salute San Raffaele, 2023. https://hdl.handle.net/20.500.11768/137019.
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Mitochondrial activity and metabolism significantly control hematopoietic stem cell (HSC) function and fate. HSCs change the metabolic state in response to stress signals, such as reactive oxygen species (ROS), which drive HSC entry into cell cycle accompanied by increased mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis. However, excessive accumulation of ROS results in oxidative damage of cellular organelles, including mitochondria. Iron is one of the sources of ROS and HSCs can uptake iron but little is known about the effects of iron on HSC metabolism.
Recently, we demonstrated an impaired function of HSCs in β-Thalassemia (BThal), a condition of systemic iron overload (IO). We also observed that IO reduces the hematopoietic supportive capacity of BThal BM mesenchymal stromal cells. However, there is no evidence of the direct effect of IO on HSCs in BThal. We hypothesized that IO and the resulting oxidative stress could alter HSC metabolism and function.
We found a positive enrichment of iron homeostasis genes in HSCs from thalassemic th3 mice, suggesting increased iron uptake and storage. Consistently, we detected high levels of free reactive iron in the cytoplasm and in mitochondria of th3 HSCs, correlating with high ROS levels. As a result, mitochondria are impaired, with low mass and activity. Interestingly, th3 multipotent progenitors inherited dysfunctional mitochondria since the rescue of mitochondrial activity occurred in the transition to more committed progenitors. In line with mitochondrial dysfunction, th3 HSCs had reduced OXPHOS-derived ATP and relied on glycolysis. In vivo reduction of mitochondrial ROS rescued mitochondrial activity and metabolism, and increased th3 HSC frequency and quiescence, thus indicating that oxidative stress is the cause of mitochondrial dysfunction and potentially HSC defects. Importantly, in vivo administration of iron dextran to wt mice generated intracellular IO and mitochondrial oxidative stress and decreased mitochondrial activity in HSCs, indicating that IO alone is sufficient to impair mitochondria.
Our study unveils that IO directly impacts on HSC metabolism by inducing oxidative stress and mitochondrial dysfunction. Alterations in mitochondrial activity and metabolic profile, in response to IO, are expected to alter HSC function. This research will add novel insight about the role of iron in regulating HSC metabolism and provide clues for improving clinical conditions associated to IO, such as BThal.L'attività e il metabolismo mitocondriali controllano in modo significativo la funzione e il destino delle cellule staminali ematopoietiche (HSC). Le HSC modificano lo stato metabolico in risposta a segnali di stress, come le specie reattive dell'ossigeno (ROS), che guidano l'ingresso delle HSC nel ciclo cellulare accompagnato da un aumento della fosforilazione ossidativa mitocondriale (OXPHOS) e della glicolisi. Tuttavia, l'eccessivo accumulo di ROS provoca il danno ossidativo degli organelli cellulari, compresi i mitocondri. Il ferro è una delle fonti di ROS e le HSC possono assorbire il ferro, ma si sa poco sugli effetti del ferro sul metabolismo delle HSC. Recentemente, abbiamo dimostrato una funzione alterata delle HSC nella β-talassemia (BThal), una condizione di sovraccarico sistemico di ferro (IO). Abbiamo anche osservato che l'eccesso di ferro riduce la capacità di supporto ematopoietica delle cellule stromali mesenchimali talassemiche. Tuttavia, non ci sono prove dell'effetto diretto del sovraccarico di ferro sulle HSC in BThal. Abbiamo ipotizzato che il sovraccarico di ferro e il conseguente stress ossidativo alterino il metabolismo e la funzione delle HSC. Abbiamo trovato un arricchimento positivo dei geni dell'omeostasi del ferro nelle HSC dei topi talassemici th3, suggerendo un aumento dell'assorbimento e dell'immagazzinamento del ferro. Coerentemente, abbiamo rilevato alti livelli di ferro reattivo libero nel citoplasma e nei mitocondri di th3 HSC, che correlano con alti livelli di ROS. Di conseguenza, i mitocondri sono alterati, con ridotta massa e attività. I progenitori multipotenti th3 hanno ereditato mitocondri disfunzionali poiché la correzione dell'attività mitocondriale si è verificata nella transizione verso progenitori più differenziati. In linea con la disfunzione mitocondriale, le HSC th3 hanno una ridotta produzione di ATP mediante OXPHOS e dipendono dalla glicolisi. La riduzione in vivo dei ROS mitocondriali ha ripristinato l'attività e il metabolismo mitocondriali e ha aumentato la frequenza e la quiescenza delle HSC th3, dimostrando così che lo stress ossidativo è la causa della disfunzione mitocondriale e dei potenziali difetti delle HSC. È importante sottolineare che la somministrazione in vivo di ferro destrano a topi wt ha generato eccesso di ferro intracellulare e stress ossidativo mitocondriale e una ridotta attività mitocondriale nelle HSC, indicando che il sovraccarico di ferro da solo è sufficiente per compromettere i mitocondri. Il nostro studio rivela che il sovraccarico di ferro ha un impatto diretto sul metabolismo delle HSC inducendo stress ossidativo e disfunzione mitocondriale. Le alterazioni dell'attività mitocondriale e del profilo metabolico, in risposta al sovraccarico di ferro, potrebbero alterare la funzione delle HSC. Questa ricerca aggiungerà nuove informazioni sul ruolo del ferro nella regolazione del metabolismo delle HSC e fornirà nuove conoscenze utili per migliorare le condizioni cliniche caratterizzate da sovraccarico di ferro, come BThal.
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Sahm, Alexander [Verfasser]. "Prognose der Schnittkräfte bei der HSC-Bearbeitung / Alexander Sahm." Aachen : Shaker, 2003. http://d-nb.info/1174513950/34.
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Bonkhofer, Florian. "Identification of novel Runx1 targets involved in HSC development." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:4badf9f4-f796-4063-8176-dd57644fd811.
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Haematopoietic stem and progenitor cells (HSPCs) are de novo generated within in the ventral aspects of the embryonic dorsal aorta (DA). Cells of this haemogenic endothelium (HE) will eventually undergo an endothelial to haematopoietic transition (EHT) that involves cell budding out of the aortic wall. Despite the detailed description of the cellular events, the exact haemogenic lineage path and the underlying molecular mechanism that establish full haematopoietic competence are still not entirely understood. The transcription factor Runx1 is critical for the emergence of HSPCs and shows expression in the zebrafish HE as early as 24 hpf. To facilitate a detailed analysis of the transient HE population I generated a TgBAC(runx1P2:Citrine) reporter line under the control of the endogenous runx1 promoter on a bacterial artificial chromosome (BAC). Double-transgenic reporter lines for runx1 and the endothelial marker kdrl allowed us to isolate specifically cells of the DA away from the whole endothelial population, which could be further sub-divided into HE and non-haemogenic cells. Genomewide expression analysis within the respective tissues and upon Runx1 loss of function enabled the identification of HE-specific Runx1-regulated genes. Hereby, the gfi1ab gene appeared as the functional homologue of the murine Gfi1. I show that in zebrafish, EHT is orchestrated through a conserved Runx1-Gfi1-Lsd1 axis. The cellular functions of the remaining Runx1 targets imply that maturation into fully functional HSCs depends on epigenetic regulation due to the up-regulation of de novo DNAmethyltransferases, as well as on factors that allow the developing HSCs to respond to extrinsic cues from haematopoietic niches. Lastly, it became evident that the early HE expresses dll4 at similar levels to the rest of the aortic endothelium, indicating a common lineage path. In the absence of RUNX1 the HE remains essentially arterial and persists as an integrated part of the DA.
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Hotakainen, L. (Lari). "HSC-3 -solujen eksosomit ja CAV-1 -proteiinin ilmeneminen." University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201705312281.
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Kielisyövän tuumorimikroympäristö ja sen eri komponentit ovat olleet viime aikoina kiivaan tutkimuksen kohteena. Näillä tekijöillä näyttäisi olevan merkitystä syövän kasvussa, invaasiossa ja leviämisessä. Mikroympäristön ominaisuuksiin vaikuttaa todennäköisesti syöpäsolujen ja tuumorin mikroympäristön molekyylivälitteinen keskustelu, ja tämän vuoropuhelun viestinvälittäjiä ovat esimerkiksi eksosomit. Eksosomit ovat kehon normaalien solujen ja syöpäsolujen erittämiä lipidikaksoiskalvollisia mikrovesikkeleitä, jotka voivat spesifisesti sitoutua kohdesoluunsa, ja muokata sen toimintaa esimerkiksi sen sisältämien proteiinien ja RNA:n välityksellä. Syöpäsolujen eksosomien kohdesoluina voivat olla esimerkiksi mesenkymaaliset kantasolut, tulehdussolut tai ns. syöpään liittyvät fibroblastit (CAFs, cancer associated fibroblasts). Kielisyövän on havaittu ilmentävän normaalia enemmän kaveoliini-1 -proteiinia (CAV-1), jonka määrä näyttäisi nousevan syövän kehitysasteen mukaan. Tässä tutkimuksessa selvitimme in vitro -laboratoriokokeilla, sisältävätkö aggressiivisen liikkuvan kielen syöpäsolulinjan (HSC-3) erittämät eksosomit CAV-1 proteiinia.
Tutkimuksiemme alkuvaiheessa loimme pohjaa eksosomieristyksen menetelmille yhteistyössä israelilaisen tutkimusryhmän kanssa. Varsinaisessa tutkimuksissamme eristimme eksosomeja HSC-3 solulinjalta käyttäen kaupallista ExoQuick-TC™ -valmistetta. Solujen eksosomieritystä indusoitiin käyttäen 4-aminofenyylielohopea-asetaattia (APMA). Kerättyjä eksosomeja ja sen sisältämiä proteiineja (CD63 ja CAV-1) tarkasteltiin immunoelektronimikroskopialla sekä Western blot -analyysillä.
Sekä immunoelektronimikroskopiassa että Western blot -analyysissä havaittiin eristettyjen eksosomien sisältävän niille tyypillistä CD63-proteiinia sekä CAV-1 -proteiinia. Saamamme tulokset viittaavat siihen, että kielisyöpäsolut saattavat olla osana CAV-1-proteiinin kertymissä tuumorin mikroympäristöön. Tällä saattaa olla merkitystä mikroympäristön muuttumisessa edullisemmaksi syövän jakaantumiselle, invaasiolle ja leviämiselle. Vaikka tutkimuksemme osoittavat eksosomien ja CAV-1-proteiinin yhteyden, tarvitaan lisätutkimuksia myös näiden kahden yhteydestä sekä in vitro -kokeissa muilla kielisyöpäsolulinjoilla että in vivo -kielisyöpätutkimuksissa. CAV-1 proteiinin rooli syövän kehityksessä on monimutkainen ja osin epäselvä, ja tämänhetkiset tutkimustulokset ovatkin osin ristiriidassa keskenään. Myös eksosomien ja CAV-1 proteiinin erityksen säätely solutasolla vaatii lisätutkimuksia. Tulokset kuuluvat BMC Cancer -lehdessä julkaistuun alkuperäisartikkeliin, jossa allekirjoittaneen työpanos on käsitelty tiivistelmäosuudessa.
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Enk, Dirk. "Untersuchungen zum dynamischen Stabilitätsverhalten von Fräswerkzeugen zur HSC-Bearbeitung." Essen Vulkan-Verl, 2009. http://d-nb.info/995794677/04.
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Sakamaki, Taro. "Hoxb5 defines the heterogeneity of self-renewal capacity in the hematopoietic stem cell compartment." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263564.
Full textBooks on the topic "HSC"
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executive, Health and safety. Drinks: List of HSC/HSE publications. Sheffield: Health and Safety Executive, Library and Information Services [sic], 1991.
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Klaffert, Thomas. Selbstoptimierende HSC-Motorspindel. Zwickau: Wissenschaftliche Scripten, 2007.
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Excel HSC physics. Glebe, N.S.W: Pascal Press, 2008.
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Peter, Carson, and Loucopoulos Peter, eds. Spotlight chemistry: HSC. Marrickville, NSW: Science Press, 2004.
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author, Metcalfe Roger, ed. Hsc engineering studies. Glebe, NSW: Pascal Press, 2013.
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executive, Health and safety. Publications in series: List of HSC/HSE publications. Sheffield: HSE Library., 1988.
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Andriessen, Michael, and Yoka McCallum. Physics 2 HSC course. 3rd ed. Milton, Qld: John Wiley & Sons, 2008.
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D, Mazierski, Wall S, and University of Toronto at Mississauga. Dept. of Health Sciences., eds. HSC 302H5 : biocommunication visualization. Toronto: utprint, 2007.
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Great Britain. Health and Safety Executive. Library and Information Service. Publications in series: List of HSC/HSE publications : January 1991. Sheffield: Health and Safety Executive, 1991.
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Great Britain. Health and Safety Commission. and Great Britain. Health and Safety Executive., eds. Highlights from the HSC annual reportr and the HSC/E accounts 1999/2000. [Sudbury]: HSE Books, 2000.
Find full textBook chapters on the topic "HSC"
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Brown, J. M. "HSC." In Landolt-Börnstein - Group II Molecules and Radicals, 1–7. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/11313410_65.
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Tschätsch, Heinz. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 315–38. Wiesbaden: Vieweg+Teubner Verlag, 2002. http://dx.doi.org/10.1007/978-3-322-94280-7_20.
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Dietrich, Jochen, and Arndt Richter. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 345–84. Wiesbaden: Springer Fachmedien Wiesbaden, 2020. http://dx.doi.org/10.1007/978-3-658-30967-1_14.
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Dietrich, Jochen. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 375–414. Wiesbaden: Springer Fachmedien Wiesbaden, 2016. http://dx.doi.org/10.1007/978-3-658-14053-3_15.
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Tschätsch, Heinz. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 297–318. Wiesbaden: Vieweg+Teubner Verlag, 2005. http://dx.doi.org/10.1007/978-3-322-99436-3_20.
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Tschätsch, Heinz, and Jochen Dietrich. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 299–326. Wiesbaden: Vieweg+Teubner, 2011. http://dx.doi.org/10.1007/978-3-8348-8197-7_15.
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Dietrich, Jochen, and Heinz Tschätsch. "Hochgeschwindigkeitszerspanung (HSC)." In Praxis der Zerspantechnik, 307–37. Wiesbaden: Springer Fachmedien Wiesbaden, 2014. http://dx.doi.org/10.1007/978-3-658-04923-2_15.
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Worel, Nina, Yavuz M. Bilgin, and Patrick Wuchter. "Mobilization and Collection of HSC." In The EBMT Handbook, 151–57. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-44080-9_16.
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AbstractThe intravenous infusion of patient’s own HSC (autologous SCT) to restore BM damage is the basic principle of high-dose chemotherapy, since otherwise the patient would expect long-lasting aplasia with life-threatening infections. Therefore, a sufficient collection of HSC before application of high-dose therapy is mandatory. Since HSC expresses CD34 on their surface, the number of CD34+ cells in the transplant material is considered as an indicator of the HSC content.The aim of infusion of HSC from a donor (allogeneic SCT) is to restore BM damage and to treat the patient’s disease. It represents a permanent cellular immunotherapy by adding a graft versus tumor effect in malignant diseases.
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Heisel, U., M. Zhang, and R. Eisseler. "Einlippentiefbohren unter HSC-Bedingungen." In Hochgeschwindigkeitsspanen metallischer Werkstoffe, 255–66. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527605142.ch11.
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Tschätsch, Heinz, and Anette Reichelt. "High speed cutting (HSC)." In Applied Machining Technology, 325–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01007-1_20.
Full textConference papers on the topic "HSC"
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Charles, Nichola, Jared Kanofsky, Jane L. Liesveld, and Michael R. King. "Using Protein-Functionalized Microchannels for Stem Cell Separation." In ASME 4th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2006. http://dx.doi.org/10.1115/icnmm2006-96228.
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Current hematopoietic stem cell (HSC) separation methods utilize immunomagnetic techniques where antibodies are conjugated to paramagnetic or iron-dextran particles so that the cells can be precipitated using a magnetic field. Antibodies are usually targeted against CD34 antigen, a known HSC marker that is lost as the cell matures into a terminally differentiated blood cell. While this method is able to produce stem cell purities greater than 80% in most cases, cell yield is usually low (<50%) and there is evidence to suggest that not all HSCs express CD34 and hence, cannot be selected using these methods. Our long-term aim is to move away from immunologic isolation methods and instead focus on general HSC behavior in the presence of specific proteins. Selectins are a group of adhesion molecules that have been shown to selectively retard HSC rolling in comparison to more mature blood cells so that, under the right conditions, HSC isolation from whole blood should be possible. Since this functional method is independent of specific HSC surface marker, it would enable isolation of all HSC sub-populations as well as improve the overall yield. We have used two geometries for HSC isolation using selectins. The first assembly was a commercially available parallel plate flow chamber with rectangular cross-section. This proved to be inefficient for cell separation due to the emergence of dead zones within the chamber and excessive cell accumulation along the tubing and fittings that comprised the inlets and outlets. We have evaluated this chamber and two redesigns using finite elements software. Ultimately we decided on a simpler approach — to replace the flow chamber with a capillary tube, which reduced unwanted cell accumulation due to gravity or dead zones while increasing the effective area for separation, and hence allowing for better HSC isolation.
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Zand, Ramtin, and Ronald F. DeMara. "HSC-FPGA." In FPGA '19: The 2019 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays. New York, NY, USA: ACM, 2019. http://dx.doi.org/10.1145/3289602.3293940.
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Phillips, S., and D. Hook. "HSC Incident Statistics." In High Speed Craft: Design & Operation. RINA, 2004. http://dx.doi.org/10.3940/rina.hs.2004.17.
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Tiwari, Vivek, Dr Vijay R. Rode, Dr Uttamasha Gupta, and Dr U. B. Choubey. "EXPERIMENTAL RESEARCH ON THE BEHAVIOR OF HIGH STRENGTH CONCRETE." In INTERSECTING HORIZONS: EXPLORING THE CONVERGENCE OF SCIENCE, TECHNOLOGY, AND ART. International Scientific and Current Research Conferences, 2023. http://dx.doi.org/10.37547/iscrc-intconf32.
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High-strength concrete, which is distinguished by its increased compressive strength and longevity, is essential in modern building. High-strength concrete (HSC) has gained popularity in the building sector due to its superior mechanical qualities and endurance when compared to traditional concrete. Present work evaluates recent experimental studies on the behavior of high-strength concrete (HSC). Present research findings are a step to explore insights into the mechanical characteristics, durability, and performance of HSC under diverse loading and environmental situations. Key experimental approaches, including as material characterization, mixture design, and testing protocols, are examined to emphasize their contributions to understanding HSC behavior. The present work examines growing trends and problems in HSC research, as well as potential research options for improving the design and use of high-strength concrete in construction applications. The introduction discusses the significance of HSC in current construction projects, focusing on its use in high-rise buildings, bridges, and infrastructure projects. The review's aims are outlined, including a summary of recent experimental research on HSC behavior, identification of major discoveries and methodology, and discussion of implications for engineering practice and research.
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URZICĂ, ANDREI, ALIN MIHU-PINTILIE, CRISTIAN CONSTANTIN STOLERIU, and DAN CRISTIAN LESENCIUC. "Using 2D Hec-RAS Modeling for Modelling Major Flood Events (Post-2000) Downstream the Stânca Costești Reservoir (Middle Sector of Prut River)." In Air and Water – Components of the Environment 2024 Conference Proceedings. Casa Cărţii de Ştiinţă, 2024. http://dx.doi.org/10.24193/awc2024_06.
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Floods have been a significant concern for Romania, with notable events post-2000. These floods have been influenced by several factors, such as climate change, massive deforestation, inadequate urban planning and inadequate hydraulic infrastructure. The regions in the north-east of the country were particularly affected, suffering serious consequences for local communities, agriculture and infrastructure. The floods caused significant losses, including human and material losses. As main response, the Romanian authorities implemented 2007/60/EC Directive whose objective is to assess and manage major flood events. Considering the national legislation, the experiment consists in reconstructing the most destructive flood events which happened on Prut River. Along the Prut River, the most important flood events (post-2000) were recorded in 2005, 2008, 2010 and 2020. Using the HEC-RAS hydraulic modeling software, four different 2D hydraulic scenarios (2D-HS) were developed: 2D-HS1 (2005 flood event), 2D-HS2 (2008 flood event), 2D-HS3 (2010 flood event), 2D-HS4 (2020 flood event). Using the maximum flood extent, the total affected areas were extracted. The flood hazard was assessed by using the Australian Institute for Disaster Resilience (AIDR) methodology which use the Depth*Velocity (D*V) raster. The results shows that 497.7 km2 were affected in the case of 2D-HS1, 569.3 km2 were affected in the case of 2D-HS2, 553.4 km2 were affected in the case of 2D-HS3 and 535.4 km2 were affected in the case of 2D-HS4.
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Behrens, Arno, Karsten Kalisch, and Jens P. Wulfsberg. "Possibilities and Problems in Finite Element Simulations of High Speed Cutting Mechanics." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59276.
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High speed cutting (HSC) has received growing attention in recent years due to its widespread applications in modern manufacturing. However, the theoretical understanding of the HSC process is considerably underdeveloped in comparison to the rapid progress of its practical application. To improve the state of knowledge of this topic, the German Research Association (DFG) has funded some research projects. One of them is the improvement of finite element simulation techniques of the HSC process. It covers the chip formation description, development of material laws for the description of HSC-conditions, the prediction of lamellar chips, the calculation of residual stresses, resulting temperature fields in the cutting tool and first descriptions of spatial chip formation. The paper will give an overview of the current progress in this project.
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Zhuo, Yue, Ji Sun Choi, Thibault Marin, Hojeong Yu, Brendan A. Harley, and Brian T. Cunningham. "Label-free Imaging with Photonic Crystal Surface for Hematopoietic Stem Cell Differentiation." In Clinical and Translational Biophotonics. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/translational.2024.jm4a.19.
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With the Photonic Resonator Outcoupler Microscopy (PROM), it is possible to detect and monitor weak-adhesive HSC adhesion without labeling. These findings indicate that PROM can be used to quantitatively and dynamically study HSC adhesion.
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Devika, Dev S., and Preena Praveen. "Investigation on Mechanical Properties of High Strength Light Weight Concrete with Exfoliated Vermiculite and Glass Fiber." In 2nd International Conference on Modern Trends in Engineering Technology and Management. AIJR Publisher, 2023. http://dx.doi.org/10.21467/proceedings.160.8.
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The concrete type known as high-strength concrete (HSC) has a high level of strength. HSC provides increased strength by the utilization of superplasticizers and silica fume. HSC is found to be very difficult to handle because of its high density. The density of HSC could be lowered with the use of lightweight aggregates. High Strength Light Weight Concrete (HSLWC) includes the behavior of both high-strength concrete and lightweight concrete. The lightweight aggregate used for HSLWC is Exfoliated Vermiculite (EV). It is a byproduct obtained from hydrous phyllosilicate minerals by heating. This provides various applications in the construction industry. This is an environmentally friendly material. Glass fibres will work as a strengthening element in concrete to make it strong and lightweight. The inclusion of glass fibers in HSLWC can raise its mechanical properties. Exfoliated vermiculite and glass fibres are integrated in this study to examine the mechanical characteristics of High Strength Lightweight Concrete (HSLWC).
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Santos, Erick de Matos, Thayse Batista Moreira, Ana Luiza de Freitas Magalhães Gomes, Ana Paula Alvares Ramos, Fábio Ribeiro Queiroz, Paulo Guilherme de Oliveira Salles, and Letícia Conceição Braga. "STANDARDIZATION OF THE FICOLL GRADIENT TECHNIQUE FOR THE ISOLATION OF MONONUCLEAR CELLS FROM PERIPHERAL BLOOD." In Brazilian Breast Cancer Symposium 2022. Mastology, 2022. http://dx.doi.org/10.29289/259453942022v32s2030.
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Objective: The objective of this study was to standardize the Ficoll gradient technique for the circulating hematopoietic stem cell (HSC) isolation for the assembly of the peripheral blood mononuclear cell (PBMC) biorepository of breast cancer (BC) patients attended in the Clinical Oncology Service of Instituto Mário Penna. Methods: The study protocol was approved by the Ethics Committee of Instituto Mário Penna (CAEE 82703418.8.0000.5121). In recommended protocols, 15 mL of blood was used. At first, we adapted this volume due to the limited amounts of samples for research available. Blood was collected in a 9-mL sodium heparin tube. The experiments were performed in 50-mL conical tubes, but with reduced blood volume, and no PBMC ring was formed. It was necessary to change to 15 mL conical tubes. Finally, the remaining red blood cells were lysed with ammonium chloride. However, with the reduced volume, this solution lysed the PBMC too. Then, we decided to remove this step from the protocol. Results: We obtained 8.06×106 cells/mm3 with 80% viability. Data were confirmed by a Neubauer camera and an automatic cell counter. The HSCs were labeled with antibodies against CD34 and CD133 by flow cytometry. Conclusion: The characterization of HSCs is important to link tumor-associated HSCs with malignant and immunosuppressive phenotypes. Studies are in progress with this standardization, and they will permit us to perform the HSC characterization of BC patients with a better knowledge of tumor microenvironment.
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Fach, K. "Classification of HSC Multihull Vessels." In Design & Operation of Trimaran Ships. RINA, 2004. http://dx.doi.org/10.3940/rina.tri.2004.09.
Full textReports on the topic "HSC"
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Cialone, H., D. N. Williams, and T. P. Groeneveld. L51621 Hydrogen-Related Failures at Mechanically Damaged Regions. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), September 1991. http://dx.doi.org/10.55274/r0010313.
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Leaks attributed to hydrogen-stress cracking (HSC) initiating in regions of mild mechanical damage have been reported in cathodically protected pipe lines constructed from high-strength, microalloyed, controlled-rolled steels. The hydrogen is believed to be present in service from the cathodic potential applied. Laboratory studies were initiated to determine the factors that contributed to those unexpected failures. Strain aging at ambient temperatures as a result of deformation introduced during the mechanical damage, was found to be a significant factor. Smooth-bar specimens that were strained and then aged failed by HSC within one week, whereas specimens that were not strain aged did not fail by HSC. Result: The findings of this research indicate a potential sequence of events which may lead to hydrogen-related failures in regions of mild mechanical damage: (1) Following the damage, ambient-temperature strain aging which promotes sensitivity to HSC takes place in the mechanically damaged region, in a surface layer of the pipe wall which has been subjected to a critical level of strain. The time period for this step would be on the order of several years. (2) Electrochemical conditions which promote hydrogen charging develop at the pipe surface from the cathodic current applied (or possibly corrosion). (3) Local stresses in the mechanically damaged region are elevated above the threshold stress for HSC by the moderate stress concentration provided by the mechanical damage. For the X70 pipe studied, the stress elevation should be at least 20 percent above the nominal hoop stress. (4) An HSC crack initiates and grows in the strain-aged surface layer. (5) The crack propagates further by HSC, through the non-strain-aged portion of the wall, as a result of the high stress concentration at the crack tip. (6) When the crack grows to a critical depth, it propagates rapidly through the wall by overload and causes a leak.
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Wormuth, Christine, and Jeremy White. Merging the HSC and NSC: Stronger Together. Fort Belvoir, VA: Defense Technical Information Center, January 2009. http://dx.doi.org/10.21236/ada494429.
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McAlpin, Jennifer, and Cassandra Ross. Houston Ship Channel Expansion Channel Improvement Project (ECIP) numerical modeling report : BABUS cell and Bird Island analysis. Engineer Research and Development Center (U.S.), August 2021. http://dx.doi.org/10.21079/11681/41581.
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The Houston Ship Channel (HSC) is one of the busiest deep-draft navigation channels in the United States and must be able to accommodate increasing vessel sizes. The US Army Engineer District, Galveston (SWG), requested the Engineer Research and Development Center, Coastal and Hydraulics Laboratory, perform hydrodynamic and sediment modeling of proposed modifications in Galveston and Trinity Bays and along the HSC. The modeling results are necessary to provide data for hydrodynamic, salinity, and sediment transport analysis. SWG provided three project alternatives that include closing Rollover Pass, Bay Aquatic Beneficial Use System cells, Bird Islands, and HSC modifications. These alternatives and a Base (existing condition) will be simulated for present (2029) and future (2079) conditions. The results of these alternatives/conditions as compared to the Base are presented in this report. The model shows that the mean salinity varies by 2–3 ppt due to the HSC channel modifications and by approximately 5 ppt in the area of East Bay due to the closure of Rollover Pass. The tidal prism increases by 2.5% to 5% in the alternatives. The tidal amplitudes change by less than 0.01 m. The residual velocity vectors vary in and around areas where project modifications are made.
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McAlpin, Jennifer, and Cassandra Ross. Houston Ship Channel numerical model update and validation. Engineer Research and Development Center (U.S.), August 2023. http://dx.doi.org/10.21079/11681/47498.
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The Houston Ship Channel (HSC) is one of the busiest deep-draft navigation channels in the United States and must be able to accommodate increasing vessel sizes. The US Army Corps of Engineers, Galveston District (SWG), requested the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, update and revalidate a previously developed three-dimensional Adaptive Hydraulics (AdH) hydrodynamic and sediment model of the HSC, Galveston, and Trinity Bays. The model is necessary for analyzing potential impacts on salinity, sediment, and hydrodynamics due to alternatives designed to reduce shoaling in the HSC. SWG requested an updated validation of the previously developed AdH model of this area to calendar years 2010 and 2017, utilizing newly collected sediment data. Updated model inputs were supplied for riverine suspended sediment loads as well as for the ocean tidal boundary condition. The updated model shows good agreement to field data in most conditions but also indicates potential issues with freshwater flow inputs as well as the ocean salinity boundary condition.
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Martin, S., Larry Daggett, Morgan Johnston, Chris Hewlett, Kiara Pazan, Mario Sanchez, Dennis Webb, Mary Allison, and George Burkley. Houston Ship Channel Expansion Improvement Project – Navigation Channel Improvement Study : ship simulation results. Coastal and Hydraulics Laboratory (U.S.), November 2021. http://dx.doi.org/10.21079/11681/42342.
Full textAbstract:
In 2020, the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory, provided technical oversight during a navigation study to assist the Galveston District evaluation of different channel widening alternatives for larger ships transiting the Houston Ship Channel (HSC), Texas. The widening proposals encompassed several areas of the HSC including the Bay Section, the Bayport Ship Channel, Barbours Cut Channel, and the Bayou Section. The study was performed at the San Jacinto College Maritime Technology and Training Center (SJCMTTC) Ship/Tug Simulator (STS) Facility in La Porte, TX. The SJCMTTC STS is a real-time simulator; therefore, events on the simulator happen at the same time rate as real life. A variety of environmental forces act upon the ship during the simulation transit. These include currents, wind, waves, bathymetry, and ship-to-ship interaction. Online simulations of the project were conducted at SJCMTTC over a 3-week period – May through June 2020. Several mariners including Houston Pilots and G&H tugboat Captains participated in the testing and validation exercises. ERDC oversight was performed remotely because of the COVID-19 pandemic. Results in the form of engineering observations, track plots, and pilot interviews were reviewed to develop final conclusions and recommendations regarding the final design.
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Canfield, Anthony J. Combat Trauma Surgery Using a Portable Contact ND-(YAG) Laser in the Porcine and Ovine Models (HSC) (CIC3). Fort Belvoir, VA: Defense Technical Information Center, January 1991. http://dx.doi.org/10.21236/ada237662.
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Bucknell, Allan L., Michael B. Simpson, Kevin P. Murphy, and Henry G. Chambers. Evaluation of Effect of Postoperative Wound Drainage Reinfusion Using the Solcotrans Orthopaedic Drainage/Reinfusion System in Reducing the Need for Whole Blood Transfusion (HSC). Fort Belvoir, VA: Defense Technical Information Center, March 1991. http://dx.doi.org/10.21236/ada238271.
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Miller, Gad, and Jeffrey F. Harper. Pollen fertility and the role of ROS and Ca signaling in heat stress tolerance. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598150.bard.
Full textAbstract:
The long-term goal of this research is to understand how pollen cope with stress, and identify genes that can be manipulated in crop plants to improve reproductive success during heat stress. The specific aims were to: 1) Compare heat stress dependent changes in gene expression between wild type pollen, and mutants in which pollen are heat sensitive (cngc16) or heat tolerant (apx2-1). 2) Compare cngc16 and apx2 mutants for differences in heat-stress triggered changes in ROS, cNMP, and Ca²⁺ transients. 3) Expand a mutant screen for pollen with increased or decreased thermo-tolerance. These aims were designed to provide novel and fundamental advances to our understanding of stress tolerance in pollen reproductive development, and enable research aimed at improving crop plants to be more productive under conditions of heat stress. Background: Each year crop yields are severely impacted by a variety of stress conditions, including heat, cold, drought, hypoxia, and salt. Reproductive development in flowering plants is highly sensitive to hot or cold temperatures, with even a single hot day or cold night sometimes being fatal to reproductive success. In many plants, pollen tube development and fertilization is often the weakest link. Current speculation about global climate change is that most agricultural regions will experience more extreme environmental fluctuations. With the human food supply largely dependent on seeds, it is critical that we consider ways to improve stress tolerance during fertilization. The heat stress response (HSR) has been intensively studied in vegetative tissues, but is poorly understood during reproductive development. A general paradigm is that HS is accompanied by increased production of reactive oxygen species (ROS) and induction of ROS-scavenging enzymes to protect cells from excess oxidative damage. The activation of the HSR has been linked to cytosolic Ca²⁺ signals, and transcriptional and translational responses, including the increased expression of heat shock proteins (HSPs) and antioxidative pathways. The focus of the proposed research was on two mutations, which have been discovered in a collaboration between the Harper and Miller labs, that either increase or decrease reproductive stress tolerance in a model plant, Arabidopsis thaliana (i.e., cngc16--cyclic nucleotide gated channel 16, apx2-1--ascorbate peroxidase 2,). Major conclusions, solutions, achievements. Using RNA-seq technology, the expression profiles of cngc16 and apx2 pollen grains were independently compared to wild type under favourable conditions and following HS. In comparison to a wild type HSR, there were 2,776 differences in the transcriptome response in cngc16 pollen, consistent with a model in which this heat-sensitive mutant fails to enact or maintain a normal wild-type HSR. In a comparison with apx2 pollen, there were 900 differences in the HSR. Some portion of these 900 differences might contribute to an improved HSR in apx2 pollen. Twenty-seven and 42 transcription factor changes, in cngc16 and apx2-1, respectively, were identified that could provide unique contributions to a pollen HSR. While we found that the functional HS-dependent reprogramming of the pollen transcriptome requires specific activity of CNGC16, we identified in apx2 specific activation of flavonol-biosynthesis pathway and auxin signalling that support a role in pollen thermotolerance. Results from this study have identified metabolic pathways and candidate genes of potential use in improving HS tolerance in pollen. Additionally, we developed new FACS-based methodology that can quantify the stress response for individual pollen in a high-throughput fashion. This technology is being adapted for biological screening of crop plant’s pollen to identify novel thermotolerance traits. Implications, both scientific and agricultural. This study has provided a reference data on the pollen HSR from a model plant, and supports a model that the HSR in pollen has many differences compared to vegetative cells. This provides an important foundation for understanding and improving the pollen HSR, and therefor contributes to the long-term goal of improving productivity in crop plants subjected to temperature stress conditions. A specific hypothesis that has emerged from this study is that pollen thermotolerance can be improved by increasing flavonol accumulation before or during a stress response. Efforts to test this hypothesis have been initiated, and if successful have the potential for application with major seed crops such as maize and rice.
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Or, Etti, David Galbraith, and Anne Fennell. Exploring mechanisms involved in grape bud dormancy: Large-scale analysis of expression reprogramming following controlled dormancy induction and dormancy release. United States Department of Agriculture, December 2002. http://dx.doi.org/10.32747/2002.7587232.bard.
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The timing of dormancy induction and release is very important to the economic production of table grape. Advances in manipulation of dormancy induction and dormancy release are dependent on the establishment of a comprehensive understanding of biological mechanisms involved in bud dormancy. To gain insight into these mechanisms we initiated the research that had two main objectives: A. Analyzing the expression profiles of large subsets of genes, following controlled dormancy induction and dormancy release, and assessing the role of known metabolic pathways, known regulatory genes and novel sequences involved in these processes B. Comparing expression profiles following the perception of various artificial as well as natural signals known to induce dormancy release, and searching for gene showing similar expression patterns, as candidates for further study of pathways having potential to play a central role in dormancy release. We first created targeted EST collections from V. vinifera and V. riparia mature buds. Clones were randomly selected from cDNA libraries prepared following controlled dormancy release and controlled dormancy induction and from respective controls. The entire collection (7920 vinifera and 1194 riparia clones) was sequenced and subjected to bioinformatics analysis, including clustering, annotations and GO classifications. PCR products from the entire collection were used for printing of cDNA microarrays. Bud tissue in general, and the dormant bud in particular, are under-represented within the grape EST database. Accordingly, 59% of the our vinifera EST collection, composed of 5516 unigenes, are not included within the current Vitis TIGR collection and about 22% of these transcripts bear no resemblance to any known plant transcript, corroborating the current need for our targeted EST collection and the bud specific cDNA array. Analysis of the V. riparia sequences yielded 814 unigenes, of which 140 are unique (keilin et al., manuscript, Appendix B). Results from computational expression profiling of the vinifera collection suggest that oxidative stress, calcium signaling, intracellular vesicle trafficking and anaerobic mode of carbohydrate metabolism play a role in the regulation and execution of grape-bud dormancy release. A comprehensive analysis confirmed the induction of transcription from several calcium–signaling related genes following HC treatment, and detected an inhibiting effect of calcium channel blocker and calcium chelator on HC-induced and chilling-induced bud break. It also detected the existence of HC-induced and calcium dependent protein phosphorylation activity. These data suggest, for the first time, that calcium signaling is involved in the mechanism of dormancy release (Pang et al., in preparation). We compared the effects of heat shock (HS) to those detected in buds following HC application and found that HS lead to earlier and higher bud break. We also demonstrated similar temporary reduction in catalase expression and temporary induction of ascorbate peroxidase, glutathione reductase, thioredoxin and glutathione S transferase expression following both treatments. These findings further support the assumption that temporary oxidative stress is part of the mechanism leading to bud break. The temporary induction of sucrose syntase, pyruvate decarboxylase and alcohol dehydrogenase indicate that temporary respiratory stress is developed and suggest that mitochondrial function may be of central importance for that mechanism. These finding, suggesting triggering of identical mechanisms by HS and HC, justified the comparison of expression profiles of HC and HS treated buds, as a tool for the identification of pathways with a central role in dormancy release (Halaly et al., in preparation). RNA samples from buds treated with HS, HC and water were hybridized with the cDNA arrays in an interconnected loop design. Differentially expressed genes from the were selected using R-language package from Bioconductor project called LIMMA and clones showing a significant change following both HS and HC treatments, compared to control, were selected for further analysis. A total of 1541 clones show significant induction, of which 37% have no hit or unknown function and the rest represent 661 genes with identified function. Similarly, out of 1452 clones showing significant reduction, only 53% of the clones have identified function and they represent 573 genes. The 661 induced genes are involved in 445 different molecular functions. About 90% of those functions were classified to 20 categories based on careful survey of the literature. Among other things, it appears that carbohydrate metabolism and mitochondrial function may be of central importance in the mechanism of dormancy release and studies in this direction are ongoing. Analysis of the reduced function is ongoing (Appendix A). A second set of hybridizations was carried out with RNA samples from buds exposed to short photoperiod, leading to induction of bud dormancy, and long photoperiod treatment, as control. Analysis indicated that 42 genes were significant difference between LD and SD and 11 of these were unique.
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Webair, Hana Hasan, Tengku Alina Tengku Ismail, and Shaiful Bahari Ismail. Health seeking behaviour among patients suffering from infertility in the Arab countries; a scoping review protocol. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, March 2022. http://dx.doi.org/10.37766/inplasy2022.3.0034.
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Review question / Objective: To identify how much and what is already known about health-seeking behavior (HSB) among the Arab patients who experienced infertility. Our purpose is to map and describe the studies that have been done and what they assessed concerning HSB among patients who experienced infertility. This includes the studies which address the factors affecting HSB. This review is conducted to display gaps in HSB literature and to inform a systematic review in the Arab countries. Condition being studied: The review will study research articles which addressed the HSB among couples, men, or women suffering from infertility. We adopted the definition of HSB by Ward et al. (1997) which is the actions undertaken by the patients who perceive themselves as infertile for the purpose to conceive and get children (Ward, Mertens, & Thomas, 1997). This could be any action ranged from neglect to seeking advanced infertility care. We will study the operational definition of HSB in each study, HSB model, rate of seeking medical care and type of care sought, other sources of help sought, and factors influencing HSB. In addition, we will describe how HSB was studied by defining the characteristics of the retrieved studies including design, setting, participants, and sample size, and infertility operational definition.