ALBERT

Description: Wearable electronic sensing devices are deemed to be a crucial technology of smart personal electronics. Strain and pressure sensors, one of the most popular research directions in recent years, are the key components of smart and flexible electronics. Graphene, as an advanced nanomaterial, exerts pre-eminent characteristics including high electrical conductivity, excellent mechanical properties, and flexibility. The above advantages of graphene provide great potential for applications in mechatronics, robotics, automation, human-machine interaction, etc.: graphene with diverse structures and leverages, strain and pressure sensors with new functionalities. Herein, the recent progress in graphene-based strain and pressure sensors is presented. The sensing materials are classified into four structures including 0D fullerene, 1D fiber, 2D film, and 3D porous structures. Different structures of graphene-based strain and pressure sensors provide various properties and multifunctions in crucial parameters such as sensitivity, linearity, and hysteresis. The recent and potential applications for graphene-based sensors are also discussed, especially in the field of human motion detection. Finally, the perspectives of graphene-based strain and pressure sensors used in human motion detection combined with artificial intelligence are surveyed. Challenges such as the biocompatibility, integration, and additivity of the sensors are discussed as well.

Description: Perovskite CsPbBr3 quantum dot (CsPbBr3-QD) recovery was performed using lead scrap from lead storage batteries. The perovskite CsPbBr3-QD characteristics were analyzed using different PbO/recycled PbO2 ratios. Scanning electron microscopy (SEM) was used to observe the film surface morphology and cross-section. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to observe the perovskite CsPbBr3-QDs’ structural characteristics. A photoluminescence (PL) measurement system was used to analyze the optical properties. The results show that lead scrap from lead–acid batteries as a material for perovskite CsPbBr3-QD production can be successfully synthesized. This saves material and also proves that recycling is valuable. The proposed approach is helpful for future material shortages and materials not easily accessible. Although the efficiency is not very high, this process will be purified using recycled lead in the future to achieve higher quantum yield.

Description: Using the City of Corvallis, Oregon, a small to medium sized American city, as a test-bed, this paper examines the City’s urban growth in relation to urban accessibility. This relationship is explored in an anatomic spatial-temporal fashion, taking account of: the number and size of developed land use parcels over time; urban accessibility from residential to non-residential land use areas; and the statistical relationships between urban form and urban accessibility. This investigation of land use is structured around use-classification and examined within a range of dimensional and demographic measurements over 5-year time periods from 1853 to 2014; concurrently, urban accessibility is measured by the least-cost path distance as calculated through the OD cost matrix analysis in GIS. The results indicate that the city grew spatially at different rates and its urban accessibility experienced both ups and downs over time. The city’s population growth corresponded closely with urban growth and its decreasing population density negatively impacted on the city’s urban accessibility to commerce, industry, and office for most time periods. Significantly, while the urban density increased steadily after 1950s concurrent with an increase in urban sprawl, in contrast to previous studies on the metropolitan condition, the urban density had no evident impact on urban accessibility in Corvallis. Instead, increasing the land-use mix was a more effective and feasible approach to reduce urban travel path distance and enhance accessibility than increasing population density or urban development density. Accordingly, this research provides evidence-based policy recommendations for planning sustainable urban mobility and urban form in small to medium-sized cities.

Description: High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) has become a standard consolidation treatment for patients with invasive lymphoma. The combination of cyclophosphamide, carmustine, and etoposide (CBV) is a commonly used conditioning regimen prior to auto-HSCT for patients with invasive lymphoma. Many modifications of the CBV regimen, including the addition of idarubicin, have been employed, with varying results. We retrospectively analyzed the clinical characteristics and treatment outcomes of 36 patients with invasive B-cell non-Hodgkin lymphoma treated with a conditioning regimen prior to auto-HSCT between January 2015 and June 2018. For our analysis, the patients were divided into two groups: one group received the classic CBV conditioning regimen and the other group received idarubicin at a dose of 8 mg/m2 for 3 days in addition to the CBV regimen. Overall survival (OS), median progression-free survival (PFS), adverse reactions, and hematopoietic reconstitution time were compared between the two groups. OS and PFS were analyzed using the Kaplan-Meier method, and the log-rank test was used for comparison between groups. Cox regression was used for multivariable analysis of other clinical factors. The median follow-up time was 29 months. Among the 36 patients in the cohort, 19 were male and 17 were female, with a male-to-female ratio of 1.12 to 1. The median age of onset was 39.5 years; 18 patients were older than 40 years and 18 were younger than 40 years. Twenty-six patients (72%) had an international prognostic index score of 0-2 and 10 patients (28%) had a score of 3-5. According to Ann Arbor staging criteria, 9 patients (25%) had stage I-II disease and 27 patients (75%) had stage III-IV disease. A total of 21 patients achieved complete remission and 15 patients achieved partial remission before transplantation. There were no significant differences between the groups in terms of neutrophil counts (P = 0.795) or platelet reconstitution time (P = 0.551). Also, there was no difference in adverse reactions between the two groups, suggesting that the addition of idarubicin to the conditioning regimen did not aggravate adverse reactions. OS and PFS were significantly longer in the idarubicin group than among patients who did not receive idarubicin. In the multivariable analysis, the use of idarubicin and complete remission state before auto-HSCT were associated with improved prognosis. These results indicate that the use of idarubicin with the CBV conditioning regimen prior to auto-HSCT is a safe and effective choice for patients with invasive B-cell non-Hodgkin lymphoma. Keywords: B-cell non-Hodgkin lymphoma; conditioning regimen; autologous hematopoietic stem cell transplantation; idarubicin Disclosures No relevant conflicts of interest to declare.

Description: The predominant outgrowth of malignant cells over their normal counterparts in a given tissue is a shared feature for all types of cancer. However, the impact of a cancer environment on normal tissue stem and progenitor cells has not been thoroughly investigated. We began to address this important issue by studying the kinetics and functions of hematopoietic stem and progenitor cells in mice with Notch1-induced leukemia. Although hematopoiesis was progressively suppressed during leukemia development, the leukemic environment imposed distinct effects on hematopoietic stem and progenitor cells, thereby resulting in different outcomes. The normal hematopoietic stem cells in leukemic mice were kept in a more quiescent state but remained highly functional on transplantation to nonleukemic recipients. In contrast, the normal hematopoietic progenitor cells in leukemic mice demonstrated accelerated proliferation and exhaustion. Subsequent analyses on multiple cell-cycle parameters and known regulators (such as p21, p27, and p18) further support this paradigm. Therefore, our current study provides definitive evidence and plausible underlying mechanisms for hematopoietic disruption but reversible inhibition of normal hematopoietic stem cells in a leukemic environment. It may also have important implications for cancer prevention and treatment in general.

Description: Abstract 1216 During leukemia development, emerging leukemic cells out-compete normal hematopoietic cells and become predominant in the body. How hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) respond to the growth of leukemic cell population is an important, yet less investigated area. Our previous study demonstrated differential effects of a leukemic environment on normal HSCs and HPCs in the Notch1-induced T-ALL mouse model (Hu X, et al. Blood 2009). We found that normal HSCs were better preserved in the leukemic bone marrow in part due to increased quiescence of the HSCs and in contrast, HPCs were exhausted during the expansion of leukemic cells. Our current work is aimed to further explore the molecular mechanisms concerning the distinct impacts of leukemic environment on normal HSCs and HPCs in the T-ALL mouse model. Given the previous report by others showing that increased secretion of stem cell factor (SCF) by myeloid leukemia cells played an important role in inducing normal HSCs/HPCs out of their niche and thus allowing leukemic cells to occupy the niche in the human-NOD/SCID xeno-graft model (Sipkins DA et al, Science 2008), we first examined the expression of SCF by ELISA, Western blot and real-time RT PCR in both normal hematopoietic and leukemic cell fractions in the Notch1-induced T-ALL mouse model as previously reported. We found that while expression of SCF in peripheral blood (PB) or bone marrow (BM) was increased in the leukemic mice, both mRNA and protein levels of SCF in normal hematopoietic cells were higher than that in leukemic cells, thereby suggesting that elevated SCF might be mainly secreted by non-leukemic cells in the leukemic hosts of our model. Further assessments on the role of SCF in leukemogenesis with the mice specifically deficient in SCF in different niche cell types are currently under investigation in our laboratory. In order to define potential mediators in HSCs in response to leukemic cell growth, a microarray study on normal HSCs isolated from T-ALL leukemic mice and the control mice was conducted. Gene expression profiling showed significantly differed expression of 169 genes (127 up and 42 down). Especially, real-time RT PCR confirmed an increase of Hes1, p21, Fbxw11, IL-18R1 and Itgb3, and a decrease of CXCR4 and Mmp2. Interestingly, the expression of Hes1 and its target gene, p21 were elevated in normal HSCs but not in HPCs, letting us to hypothesize that Hes1 might be in part mediate the different responses of HSCs and HPCs to the T-ALL leukemic environment. To test this hypothesis, we ectopically expressed Hes1 in normal hematopoietic cells and then examined their functions under the leukemic condition. BM cells from B6.SJL mice were transduced with either MSCV-Hes1-IRES-GFP or control MSCV-GFP vector. After transduction, Hes1-GFP+or control-GFP+cells were co-transplanted with the Notch1-induced T-ALL cells into lethally irradiated C57BL/6J recipients. The engrafted cells from the leukemic BM were analyzed and Hes1-GFP+or control-GFP+cells were sorted for functional assessments. Interestingly, although over-expression of Hes1 inhibited the growth of colony forming cell (CFC) in vitro, it could potentiate the long-term repopulating cells by maintaining more cells in the quiescent (G0) state in vivo. Taken together, our current study supports a role of Hes1 in mediating the distinct responses of normal HSCs and HPCs to the T-ALL leukemic environment. Disclosures: No relevant conflicts of interest to declare.

Description: Acute myeloid leukemia (AML) is a group of heterogeneous hematopoietic malignancies sustained by a small population of leukemic stem cells (LSCs) that can resist treatment and act as barriers to cure. Previously, we observed that Hes1 and p21 expression was down-regulated in AML cell lines compared to that of normal bone marrow mononuclear cells. However, the activation status of Hes1-p21 pathway and its regulation in LSCs as well as normal hematopoietic stem cells (HSCs) in AML has not been elucidated. In this study, the Hes1-p21 pathway in LSCs and leukemic progenitors (LPs) was studied in adult CD34+ AML with normal karyotype and no genetic mutations and the upstream miRNA regulators were screened. Our results showed that the level of either Hes1 or p21 was lower in LSCs or LPs than that of HSCs whereas the level of miR-9 was higher in LSCs or LPs than HSCs. An inverse correlation was observed in the expression of Hes1 and miR-9. Furthermore, we validated miR-9 as one of the regulators of Hes1 by reporter gene analysis. Knockdown of miR-9 by lentivirus infection suppressed the proliferation of AML cells by the induction of G0 arrest and apoptosis in vitro. Moreover, knockdown of miR-9 resulted in decreased circulating leukemic cell counts in peripheral blood and bone marrow, attenuated splenomegaly, and prolonged survival in a xenotransplant mouse model. Our results indicate that the miR-9-Hes1-p21 pathway plays an important role in supporting AML cell growth and survival, and that miR-9 has a potential to be a therapeutic target for suppressing AML. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 4417 Nucleotides are new players in intercellular communication network. Abnormal signaling leads to cell dysfunction and diseases. P2X family receptors, consisting of seven members, are ATP-gated plasma membrane ion channels widely distributed in different organs, tissues, and cells with diverse biological functions. Their distribution patterns and significance in pediatric leukemias have not been established though the abnormal expression of P2×7 receptor was reported in leukemias. Here we investigated the expression of P2X family receptors in BMMC samples from 124 Chinese pediatric acute leukemia patients (85 boys and 39 girls; 66 newly diagnosed ALL, 37 newly diagnosed AML, 17 relapsed ALL, and 4 relapsed AML) with the median age of 8 (range, 1-16 years) as well as 20 childhood normal healthy controls. Relative quantitative real-time PCR results showed that P2×1, 4, 5, 7 receptors were simultaneously over expressed in newly diagnosed ALL patients (p=0.04, p

Description: Notch signal pathway is an important mediator of growth and survival in several cancer types, while Notch pathway genes function as oncogenes or tumor suppressors in different cancers. Although aberrant Notch activation contributes to leukemogenesis in T cells, the role of Notch pathway in acute myeloid leukemia (AML) remains unclear. To address this problem, we investigated the expression levels of its downstream effector Hes1 and p21 in primary AML cells and cell lines by realtime PCR and western, and found that both of them was weak in these cells. Induced activation of Hes1 consisently led to AML growth arrest and apoptosis, which was associated with enhanced p21 expression. Besides, overexpression of Hes1 inhibited growth of AML cells in vivo. In conclusion, we reported that Hes1 mediated growth arrest and apoptosis of human AML cells, and demonstrated a novel tumor suppressor role for Hes1 in AML. Disclosures No relevant conflicts of interest to declare.

Description: Acute myeloid leukemia (AML) is not sensitive to chemotherapy partially because of the protection of AML cells by mesenchymal stromal cells (MSCs). Our previous studies found that MSCs protected AML cells from apoptosis through the c-Myc-dependent pathway. However, the mechanism by which MSCs regulate c-Myc in AML cells is still unknown. To elucidate the mechanism, we performed microRNA array analysis of AML cell lines and validated by TaqMan realtime PCR. The results showed that the expression of microRNA-494 (miR-494) in AML cells after coculture with MSCs was down-regulated. Reporter gene analysis confirmed miR-494 as one of the regulators of c-Myc. In the coculture system, activation of miR-494 in AML cells suppressed proliferation and induced apoptosis of AML cells in vitro. After addition of mitoxantrone to the coculture system, the proliferation of AML cells with miR-494 activation was suppressed more than that of control cells. After subcutaneous injection of AML cell lines in combination with MSC, tumor growth was suppressed in mice injected with miR-494-overexpressing AML cells. The rate of tumor formation was even lower after mitoxantrone treatment in the miR-494 overexpressing group. Moreover, miR-494 activation resulted in a decrease of leukemic cell counts in peripheral blood and bone marrow and prolonged survival in mice injected with miR-494-overexpressing AML cellls and MSCs compared to the control mice. Our results indicate that miR-494 suppresses drug resistance in AML cells by down-regulating c-Myc through interaction with MSCs and that miR-494 therefore is a potential therapeutic target. Disclosures No relevant conflicts of interest to declare.