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Since late 2019, coronavirus disease 2019 (COVID-19) has led to a significant increase in the demand for medical resources. To publish data on face mask supplies, the Taiwanese government collaborated with program developers to construct a mask-supply information transitional platform (MITP). To comprehend the adoption of MITP, the study proposes a research model that integrates the health behavior model (HBM) and IS/IT continuance model for examining the factors affecting intention to use an MITP. Survey data collected from 524 respondents indicated that (1) intention to use an MITP is directly influenced by perceived threat of COVID-19 and beliefs toward using the MITP; (2) cues to action directly influence the perceived threat of COVID-19; and (3) perceived ease of use of MITP is a significant determinant of perceived usefulness of MITP. These results provide practical guidelines for health authorities and government to develop health information systems and strategies to control pandemics.

Amino acid-mediated metabolism is one of the key catabolic and anabolic processes involved in diverse cellular functions. However, the role of the semi-essential amino acid arginine in normal and malignant hematopoietic cell development is poorly understood. Here we report that a continuous supply of exogenous arginine is required for the maintenance/function of normal hematopoietic stem cells (HSCs). Surprisingly, knockout of Slc7a3 (CAT3), a major L-arginine transporter, does not affect HSCs in steady-state or under stress. Although Slc7a3 is highly expressed in naïve and activated CD8 T cells, neither T cell development nor activation/proliferation is impacted by Slc7a3 depletion. Furthermore, the Slc7a3 deletion does not attenuate leukemia development driven by Pten loss or the oncogenic Ptpn11E76K mutation. Arginine uptake assays reveal that L-arginine uptake is not disrupted in Slc7a3 knockout cells. These data suggest that extracellular arginine is critically important for HSCs, but CAT3 is dispensable for normal hematopoiesis and leukemogenesis.

Amino acid (AA) metabolism is involved in diverse cellular functions, including cell survival and growth, however it remains unclear how it regulates normal hematopoiesis versus leukemogenesis. Here, we report that knockout of Slc1a5 (ASCT2), a transporter of neutral AAs, especially glutamine, results in mild to moderate defects in bone marrow and mature blood cell development under steady state conditions. In contrast, constitutive or induced deletion of Slc1a5 decreases leukemia initiation and maintenance driven by the oncogene MLL-AF9 or Pten deficiency. Survival of leukemic mice is prolonged following Slc1a5 deletion, and pharmacological inhibition of ASCT2 also decreases leukemia development and progression in xenograft models of human acute myeloid leukemia. Mechanistically, loss of ASCT2 generates a global effect on cellular metabolism, disrupts leucine influx and mTOR signaling, and induces apoptosis in leukemic cells. Given the substantial difference in reliance on ASCT2-mediated AA metabolism between normal and malignant blood cells, this in vivo study suggests ASCT2 as a promising therapeutic target for the treatment of leukemia.

As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results., 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.04434

Big data has been widely discussed for several years. However, whether the implementation of big data really bring in observable benefits on firm performance remains a critical issue for the top management team. In this study, we investigate the association between big data implementation and the corresponding financial performance, productivity, and market value. Our results demonstrate that big data implementation is positively related to an improvement in financial performance and the market value but such effect is not stronger for first movers. Implications are discussed.

One of the regular tasks for managers is to formulate various marketing strategies to confront competitive and changing market environments. Therefore, identifying product sales trends in order to evolve a better strategy is an important issue. It is also an issue that disturbs managers because the preferences of customers often change and capturing them is not an effortless process. In the data mining field, emerging patterns (EPs) are defined as itemsets of which supports increase significantly from one dataset to another. EPs, therefore, can capture emerging trends in timestamped databases or useful contrasts between data classes. In this study, we integrate the concepts of product life cycle and emerging patterns to define four emerging patterns, referred to here as Growth patterns, Rapid-Rise patterns, Decline patterns, and Rapid-Sink patterns, so as to identify interesting sales trends. In addition, we propose a new approach to discover these four emerging patterns from two real-life datasets. Experimental results show that the proposed approach can help managers identify these four types of patterns and interesting trends.

Dipeptidylpeptidase 4 (DPP4/CD26) enzymatically cleaves select penultimate amino acids of proteins, including colony-stimulating factors (CSFs), and has been implicated in cellular regulation. To better understand the role of DPP4 regulation of hematopoiesis, we analyzed the activity of DPP4 on the surface of immature blood cells and then comparatively assessed the interactions and functional effects of full-length (FL) and DPP4 truncated (T) factors (T-granulocyte-macrophage-CSF (T-GM-CSF)) and T-interleukin-3 (T-IL-3)) on both in vitro and in vivo models of normal and leukemic cells. T-GM-CSF and -IL-3 had enhanced receptor binding, but decreased CSF activity, compared with their FL forms. Importantly, T-GM-CSF and -IL-3 significantly, and reciprocally, blunted receptor binding and myeloid progenitor cell proliferation activity of both FL-GM-CSF and -IL-3 in vitro and in vivo. Similar effects were apparent in vitro using cluster-forming cells from patients with acute myeloid leukemia regardless of cytogenetic or molecular alterations and in vivo using animal models of leukemia. This suggests that DPP4 T-molecules have modified binding and functions compared with their FL counterparts and may serve regulatory roles in normal and malignant hematopoiesis.

Activating mutations, such as E76K and D61Y, in PTPN11 (SHP2), a protein tyrosine phosphatase implicated in multiple cell signaling processes, are associated with 35% of patients with juvenile myelomonocytic leukemia (JMML), an aggressive childhood myeloproliferative neoplasm (MPN). Effective therapeutic interventions for this malignancy are still lacking. Here we show that the interaction between leukemia-associated mutant Shp2 and Gab2, a scaffolding protein important for cytokine-induced PI3K/Akt signaling, was enhanced, and that the mTOR pathway was elevated in Ptpn11E76K/+ leukemic cells. Importantly, MPN induced by the Ptpn11E76K/+ mutation was markedly attenuated in Ptpn11E76K/+/Gab2−/− double mutant mice — Overproduction of myeloid cells was alleviated, splenomegaly was diminished, and myeloid cell infiltration in non-hematopoietic organs was decreased in these double mutants. Excessive myeloid differentiation of stem cells was also normalized by depletion of Gab2. Acute leukemia progression of MPN was reduced in the double mutant mice, and as such, their survival was much prolonged. Furthermore, treatment of Ptpn11E76K/+ mice with Rapamycin, a specific and potent mTOR inhibitor, mitigated MPN phenotypes. Collectively, this study reveals an important role of the Gab2/PI3K/mTOR pathway in mediating the pathogenic signaling of the PTPN11 gain-of-function mutations, and a therapeutic potential of Rapamycin for PTPN11 mutation-associated JMML.

Germline activating mutations of the protein tyrosine phosphatase SHP2 (encoded by PTPN11), a positive regulator of the RAS signalling pathway, are found in 50% of patients with Noonan syndrome. These patients have an increased risk of developing leukaemia, especially juvenile myelomonocytic leukaemia (JMML), a childhood myeloproliferative neoplasm (MPN). Previous studies have demonstrated that mutations in Ptpn11 induce a JMML-like MPN through cell-autonomous mechanisms that are dependent on Shp2 catalytic activity. However, the effect of these mutations in the bone marrow microenvironment remains unclear. Here we report that Ptpn11 activating mutations in the mouse bone marrow microenvironment promote the development and progression of MPN through profound detrimental effects on haematopoietic stem cells (HSCs). Ptpn11 mutations in mesenchymal stem/progenitor cells and osteoprogenitors, but not in differentiated osteoblasts or endothelial cells, cause excessive production of the CC chemokine CCL3 (also known as MIP-1α), which recruits monocytes to the area in which HSCs also reside. Consequently, HSCs are hyperactivated by interleukin-1β and possibly other proinflammatory cytokines produced by monocytes, leading to exacerbated MPN and to donor-cell-derived MPN following stem cell transplantation. Remarkably, administration of CCL3 receptor antagonists effectively reverses MPN development induced by the Ptpn11-mutated bone marrow microenvironment. This study reveals the critical contribution of Ptpn11 mutations in the bone marrow microenvironment to leukaemogenesis and identifies CCL3 as a potential therapeutic target for controlling leukaemic progression in Noonan syndrome and for improving stem cell transplantation therapy in Noonan-syndrome-associated leukaemias.

Many previous studies have focused on the extraction of association rules from transaction data. Unfortunately, customer purchasing intentions tend to be uncertain during the decision making process. That is, they cannot be obtained from business transaction data. Therefore, the research problem is how to discover frequent itemsets from uncertain data. This study first proposes a new model to represent consumer uncertainty during the decision making process. This representation scheme is based on possibility distributions. The possibility theory provides an excellent framework for handling uncertain data. In addition, an algorithm is developed to mine plausible-frequent itemsets from uncertain data, which are represented by possibility distributions, and then discover plausible association rules based on these plausible-frequent itemsets. Experimental results show that the proposed model can discover interesting plausible-frequent patterns from survey data which represent customer purchasing decisions.

Longtime behavior of degenerate equations with the nonlinearity of polynomial growth of arbitrary order on the whole space ℝ N is considered. By using l-trajectories methods, we proved that weak solutions generated by degenerate equations possess an (L 2 (ℝ N ), L loc 2 (ℝ N ))-global attractor. Moreover, the upper bounds of the Kolmogorov ɛ-entropy for such global attractor are also obtained.

Identification of changes in customer behavior is a major challenge that must be tackled in order to survive in a rapidly changing business environment. For example, because information technology has advanced and data-storage costs have declined, for the purpose of serving customers, numerous enterprises have employed information systems and have directly logged customer behavior in databases. This trend has motivated the development of data mining applications. Fuzzy quantitative sequential pattern mining is a functional data mining technique that is used for discovering customer behavioral patterns over time and determining the quantities of goods or services they purchase. The example term used in shopping ?[(Beer, Low)(Milk, High)] (Cola, Middle)? means that customers will first buy Beer and Milk in Low and High quantities, respectively, and then purchase Cola in Middle quantities on their next shopping trip, where Low, Middle, and High are predefined linguistic terms assigned by managers. A term such as this one provides managers with general and concise knowledge related to customer behavior and allows them to rapidly make decisions in response, especially in a competitive setting. However, literature searches indicate that no previous study has addressed the issue of changes in fuzzy quantitative sequential patterns. The aforementioned example pattern might have been available last year but might not be used this year, and it could have been substituted by ?(Beer, Middle) {(Cola, Low)(Milk, Low)}?. If this knowledge is not renewed, managers might develop inappropriate marketing plans for their products or services and use inventory strategies that are outdated with respect to time and quantities. To solve this problem, we propose a novel change-mining model that can be used for detecting changes in fuzzy quantitative sequential patterns. We conducted experiments in which we used real-world and synthetic datasets in order to evaluate the proposed model. When the pattern change was detected using the real-world dataset, the results showed that the model reveals 3 considerations that can help managers with their handling of products' marketing and production. When we studied the model's scalability by using the synthetic dataset, the results showed that even though all run times increased when parameter values were decreased, the model remained scalable.

The quality characteristics of cheonggukjang containing Phellinus linteus extracts (PLE) and its cytotoxicity in Hep-2 and SK-MS-cells were investigated. Cheonggukjang containing 0.3% PLE showed the highest protease activity (7th aging day). The reducing sugar content and the amylase activity of cheonggukjang supplemented with 0.3% PLE increased immediately on the 1st aging day, and decreased slightly until the 15th aging day. All samples showed an increase in the amino-type nitrogen content. The dominant volatile compound detected using chromatography-mass spectrophotometry was 2,5-dimethyl pyrazine with the highest peak area value of 17.36% observed in cheonggukjang containing 0.3% PLE (3rd aging day). Cheonggukjang containing 0.3% PLE exhibited the best taste and acceptability with the least unpleasant odor. Cheonggukjang supplemented with PLE had a higher antitumor activity against SK-MES-1 and Hep-2 cells than a control. Hep-2 cells treated with a 10 mg/mL extract of cheonggukjang containing 0.3% PLE showed the highest growth inhibition rate of 84.74%.

Through the experiments of 7 T-section composite beams, steel fiber reinforced self-stressing concrete (SFRSC) as the composite beam in the composite layer was studied under the hogging bending. The tests simulated composite layer tensile strain under the hogging bending of inverted loading composite beams, giving the relationship under the different fatigue stress ratios between fatigue cycles and steel bar’s stress range, crack width, stiffness loss and damage, etc., in composite layer. This article established fatigue life equation, and analyzed SFRSC reinforced mechanism to crack width and stiffness loss. The results show that SFRSC as the composite beam concrete has excellent properties of crack resistance and tensile, can reinforce the fatigue crack width and stiffness loss of composite beams, and improve the durability and in normal use of composite beams in the hogging bending zone.

The special reinforced concrete composite beam consists of a steel fiber reinforced self-stressing concrete composite layer and a reinforced concrete T-beam, and constructional bars are set up at their bonding interface. Fatigue properties of the composite beam under the action of negative moment were experimentally studied. Through inverted loading mode the load-bearing state of a composite beam was simulated under the action of negative moment. With the ratios of constructional bars being 0, 0.082% and 0.164% respectively as parameters, the effects of constructional bars on the properties of composite beam, such as fatigue life, crack propagation, rigidity loss as well as damage behavior of bonding interface, were studied. The mechanism of the constructional bars on the fatigue properties of the composite beams and the restriction mechanism of crack widths and rigidity loss were analyzed. The test results show that the constructional bars can enhance the shear resistance of the bonding interface between composite layer and old concrete beam and restrict expanding of steel fiber reinforced self-stressing concrete, which are beneficial to synergistic action of composite layer and old concrete beam, to reducing the stress amplitude of bars and the crack width of composite layer, and to increasing the durability and fatigue life of the composite beam.

Steel wire wound reinforced flexible pipe in this study mainly consists of multiple anisotropic steel wire wound reinforcement layers and multiple isotropic rubber layers. Based on 3D anisotropic elastic theory, the analytic solutions of stresses and elastic deformations of steel wire wound reinforced rubber flexible pipe under internal pressure are presented. As the adjacent reinforcement layers with wound angle have different radii, the single reinforcement layer shows the effect of tensile-shear coupling. Moreover, the static loading test results of steel wire wound reinforced rubber flexible pipe under internal pressure are basically coincided with the calculated values by present method.

The intracellular Ca(2+) concentration ([Ca(2+)](i)) in skeletal muscles must be rapidly regulated during the excitation-contraction-relaxation process. However, the signalling components involved in such rapid Ca(2+) movement are not fully understood. Here we report that mice deficient in the newly identified PtdInsP (phosphatidylinositol phosphate) phosphatase MIP/MTMR14 (muscle-specific inositol phosphatase) show muscle weakness and fatigue. Muscles isolated from MIP/MTMR14(-/-) mice produced less contractile force, had markedly prolonged relaxation and showed exacerbated fatigue relative to normal muscles. Further analyses revealed that MIP/MTMR14 deficiency resulted in spontaneous Ca(2+) leakage from the internal store - the sarcoplasmic reticulum. This was attributed to decreased metabolism (dephosphorylation) and the subsequent accumulation of MIP/MTMR14 substrates, especially PtdIns(3,5)P(2) and PtdIns (3,4)P(2). Furthermore, we found that PtdIns(3,5)P(2) and PtdIns(3,4)P(2) bound to, and directly activated, the Ca(2+) release channel (ryanodine receptor 1, RyR1) of the sarcoplasmic reticulum. These studies provide the first evidence that finely controlled PtdInsP levels in muscle cells are essential for maintaining Ca(2+) homeostasis and muscle performance.

We prove the existence of global attractors in \( H^{1}_{0} {\left( \Omega \right)} \) for a nonclassical diffusion equation. Two types of nonlinearity f are considered: one is the critical exponent, and the other is the polynomial growth of arbitrary order.

A whole of 110 specimens divided into 22 groups were tested with varying the volume fraction of steel fibers and the matrix strength of these specimens. The stress-strain behaviors of four types of steel fiber reinforced concrete (SFRC) under uniaxial tension were studied experimentally. When the matrix strength and the fiber content increase, the tensile stress and tensile strain vary differently according to the fiber type. The mechanisms of reinforcing effect for different type of fiber were analyzed and the stress-strain curves of the specimens were plotted. Some experimental factors for stress or strain of SFRC were given. A tensile toughness modulus Re0.5 was introduced to evaluate the toughness characters of SFRC under uniaxial tension. Moreover, the formula of the tensile stress-strain curve of SFRC was regressed. The theoretical curve and the experimental one fit well, which can be used for references in construction.

An optimal maintenance program is the key to making appropriate decisions to minimize cost and maintain an appropriate level of safety. In this paper, the strategy on repairing and strengthening of existing bridges based on time-dependent reliability was analyzed with the maximum expected benefit as the objective function. Risk ranking and lifecycle cost analysis were considered in the reliability-based bridge assessment. A practical application of risk-ranking decision was illustrated herein based on updated inspection information with the bridge at survival age 35. The effects of improvement of live load and difference of repair methods on time-dependent reliability of existing bridges were studied. The decision method can be used in real projects, with the cost of failure consequence and the risk of failure considered.

In this paper, we study the stochastic comparisons of minimal repair replacement policies in repairable case. We give some results on comparisons of the same unit for different policies and on comparisons of the same policies for different units.

Shp-2 is a ubiquitously expressed tyrosine phosphatase with two SH2 domains. Homozygous mutant mice with a targeted deletion of 65 amino acid residues in the N-terminal SH2 domain of Shp-2 die in utero at mid-gestation, with multiple defects in mesodermal patterning. To surpass the embryonic lethality in dissecting the Shp-2 function in cell growth and differentiation, we established homozygous Shp-2 mutant embryonic stem (ES) cell lines. Our previous data showed a severe suppression of hematopoietic cell differentiation from Shp-2 mutant ES cells. Here we demonstrate that development of cardiac muscle cells was dramatically delayed and impaired in embryoid bodies (EBs) of Shp-2 mutant origin. Shp-2 mutant ES cells failed to differentiate into epithelial and fibroblast cells in vitro. However, higher efficiency of secondary EB formation was observed from the mutant than the wild-type ES cells. Further, mutant ES cells were more sensitive than wild-type cells to the differentiation suppressing effect of leukemia inhibitory factor (LIF). In addition, mutant ES cells showed a reduced growth rate compared to wild-type cells. These results suggest that the Shp-2 tyrosine phosphatase is a positive regulator for both cell differentiation and proliferation, in contrast to the Src-family kinases which promote cell growth but block differentiation.