115 research outputs found

    Intergenomic and epistatic interactions control free radical mediated pancreatic β-cell damage.

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    Alloxan (AL)-generated Reactive Oxygen Species (ROS) selectively destroy insulin-producing pancreatic β-cells. A previous genome-wide scan (GWS) using a cohort of 296 F2 hybrids between NOD (AL-sensitive) and ALR (AL-resistant) mice identified linkages contributing to β-cell susceptibility or resistance to AL-induced diabetes on Chromosomes (Chr) 2, 3, 8, and a single nucleotide polymorphism i

    Silencing of PTK7 in Colon Cancer Cells: Caspase-10-Dependent Apoptosis via Mitochondrial Pathway

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    Protein tyrosine kinase-7 (PTK7) is a catalytically inactive receptor tyrosine kinase (RTK). PTK7 is upregulated in many common human cancers, including colon cancer, lung cancer, gastric cancer and acute myeloid leukemia. The reason for this up-regulation is not yet known. To explore the functional role of PTK7, the expression of PTK7 in HCT 116 cells was examined using small interference (siRNA)-mediated gene silencing. Following transfection, the siRNA successfully suppressed PTK7 mRNA and protein expression. Knocking down of PTK7 in HCT 116 cells inhibited cell proliferation compared to control groups and induced apoptosis. Furthermore, this apoptosis was characterized by decreased mitochondrial membrane potential and activation of caspase-9 and -10. Addition of a caspase-10 inhibitor totally blocked this apoptosis, suggesting that caspase-10 may play a critical role in PTK7-knockdown-induced apoptosis, downstream of mitochondria. These observations may indicate a role for PTK7 in cell proliferation and cell apoptosis and may provide a potential therapeutic pathway for the treatment of a variety of cancers

    THE APPLICATION OF WIRELESS SENSOR NETWORKS IN MANAGEMENT OF ORCHARD

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    Abstract: A monitoring system based on wireless sensor network is established, aiming at the difficulty of information acquisition in the orchard on the hill at present. The temperature and humidity sensors are deployed around fruit trees to gather the real-time environmental parameters, and the wireless communication modules with self-organized form, which transmit the data to a remote central server, can realize the function of monitoring. By setting the parameters of data intelligent analysis judgment, the information on remote diagnosis and decision support can be timely and effectively feed back to users

    A New Method for Estimating Irrigation Water Use via Soil Moisture

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    The ability to obtain an accurate measure of irrigation water use is urgently needed in order to provide further scientific guidance for irrigation practices. This investigation took soil moisture and precipitation as the study objects and quantitatively analyzed their relationship by establishing four models: a linear model, a logarithmic model, a soil water balance model, and a similarity model. The results from building models on every site clearly revealed the relationship between soil moisture and precipitation and confirmed the feasibility of estimating irrigation water use when soil moisture data are known. Four models combined with soil moisture data were used to estimate irrigation water use. First, the 16 sites which monitor soil moisture conditions in Hebi City were identified as study objects, from which everyday meteorological data (temperature, precipitation, atmospheric pressure, wind speed, sunshine duration) and soil moisture data from 2015 to 2020 (totaling six years) were collected. Second, the eligible data from the first four years in the date range were used to create four kinds of models (linear model, logarithmic model, soil water balance model, and similarity model) to estimate the amount of water input to the soil surface based on soil moisture. Third, the eligible data from the last two years in the established date range were used to verify the established models on every site and then judge the accuracy of the models. For example, for site 53990, the RMSE of the linear model, logarithmic model, soil water balance model, and similarity model was 10,547, 10,302, 8619, and 7524, respectively. The results demonstrate that the similarity model proposed in this study can express the quantitative relationship between soil moisture and precipitation more accurately than the other three models. Based on this conclusion, the eligible soil moisture data known in the specific site were ultimately used to estimate the irrigation water use in the field by the relationship expressed in the similarity model. Compared with the amount of irrigation water data recorded, the estimated irrigation water use yielded by the similarity model in this study was 18.11% smaller. In a future study, microwave satellite remote sensing of soil moisture data, such as SMAP and SMOS soil moisture data, will be used to evaluate the performance of estimated regional irrigation water use

    Fatigue Property and Residual Stress Relaxation Behavior of High-Energy Shot Peened Pure Zr

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    High-energy shot peening (HESP) was conducted on commercial pure Zr to generate a surface gradient nanostructured layer and compressive residual stress (CRS). The microstructure, residual stress, and fracture morphology were investigated by electron back scattering diffraction (EBSD), scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD), respectively. Tensile fatigue tests were conducted and the fatigue property was presented through S-N curve. By the XRD measurement, the residual stress relaxation and the microstructure evolution on the HESPed surface were studied under different stress amplitudes. The results indicated that the fatigue limit of the HESPed sample was 23% higher than that of the as-received. The relaxation of residual stress was observed during fatigue loading; the initial relaxation rate was fast and the later was slow, accompanied by a similar degree of nanocrystalline coarsening and dislocation density reduction. A linear relationship between the surface residual stress and the number of cycles for the HESPed sample was quantitatively described. The higher the applied stress amplitude was, the faster the residual stress relaxation (RSR) was. The stress amplitude had an important influence on the relaxation rate, the degree of nanocrystals coarsening, and dislocation density. Local plastic deformation caused grain coarsening and dislocation density reduction

    Be12O12 Nano-cage as a Promising Catalyst for CO2 Hydrogenation

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    An efficient conversion of CO2 into valuable fuels and chemicals has been hotly pursued recently. Here, for the first time, we have explored a series of M12x12 nano-cages (M = B, Al, Be, Mg; X=N, P, O) for catalysis of CO2 to HCOOH. Two steps are identified in the hydrogenation process, namely, H2 activation to 2H*, and then 2H* transfer to CO2 forming HCOOH, where the barriers of two H* transfer are lower than that of the H2 activation reaction. Among the studied cages, Be12O12 is found to have the lowest barrier in the whole reaction process, showing two kinds of reaction mechanisms for 2H* (simultaneous transfer and a step-wise transfer with a quite low barrier). Moreover, the H2 activation energy barrier can be further reduced by introducing Al, Ga, Li, and Na to B12N12 cage. This study would provide some new ideas for the design of efficient cluster catalysts for CO2 reduction.NRF (Natl Research Foundation, S’pore)Published versio

    Efficient Nanovaccine Delivery in Cancer Immunotherapy

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    Vaccines hold tremendous potential for cancer immunotherapy by treating the immune system. Subunit vaccines, including molecular adjuvants and cancer-associated antigens or cancer-specific neoantigens, can elicit potent antitumor immunity. However, subunit vaccines have shown limited clinical benefit in cancer patients, which is in part attributed to inefficient vaccine delivery. In this Perspective, we discuss vaccine delivery by synthetic nanoparticles or naturally derived nanoparticles for cancer immunotherapy. Nano vaccines can efficiently codeliver adjuvants and multiepitope antigens into lymphoid organs and into antigen-presenting cells, and the intracellular release of vaccine and cross presentation of antigens can be fine-tuned via nanovaccine engineering. Aside from peptide antigens, antigen-encoding mRNA for cancer immunotherapy delivered by nanovaccine will also be discussed

    Cataluminescence and catalysis properties of CO oxidation over porous network of ZrO\u3csub\u3e2\u3c/sub\u3e nanorods synthesized by a bio-template

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    A network of ZrO 2 nanorods was prepared using the porous biomembranes as templates. The sample was characterized by SEM, XRD and nitrogen physicosorption isotherm. ZrO 2 nanoparticles were also prepared with a hydrothermal method in order to compare with this network. The results showed that after being calcined at 800 °C for 24 h, a volume contraction of ZrO 2 nanorod network occurred accompanied by a phase transformation of tetragonal-to-monoclinic ZrO 2; but the nanoparticles have grown into the large microparticles; as a result, ZrO 2 nanorod network has a higher BET area (45.7 m 2 g -1) and a larger pore volume (0.20 cm 3 g -1). The calcined network showed a higher cataluminescence (CL) intensity of CO oxidation and a higher combustion activity than the calcined particles, which was ascribed its high surface area, as well as advanced pores. © Teng et al

    Engineering a Cell-Surface Aptamer Circuit for Targeted and Amplified Photodynamic Cancer Therapy

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    National Key Scientific Program of China [2011CB911000]; Foundation for Innovative Research Groups of NSFC [21221003]; China National Instrumentation Program [2011YQ03012412]; National institutes of Health [GM066137, GM079359, CA133086]Photodynamic therapy is one of the most promising and noninvasive methods for clinical treatment of different malignant diseases. Here, we present a novel strategy of designing an aptamerbased DNA nanocircult capable of selective recognition of cancer cells, controllable activation of photosensitizers, and amplification of photodynamic therapeutic effect. The aptamers can selectively recognize target cancer cells and bind to the specific proteins on cell membranes. Then the overhanging catalyst sequence on the aptamer can trigger a toeholdmediated catalytic strand displacement to activate the photosensitizer and achieve amplified therapeutic effect. The specific binding-induced activation allows the DNA circuit to distinguish diseased cells from healthy cells, reducing damage to nearby healthy cells. Moreover, the catalytic amplification reaction will only take place close to the target cancer cells, resulting in a high local concentration of singlet oxygen to selectively kill the target cells. The principle employed In this study demonstrated the feasibility of assembling a DNA circuit on cell membranes and could further broaden the utility of DNA circuits for applications In biology, biotechnology, and biomedicine
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