51 research outputs found
Thick Film Thermistors Printed on Low Temperature Co-fired Ceramic Tapes
Focuses on the importance of ceramic tapes as a substrate material for hybrid microelectronic circuits. Fabrication of thermal reactor; Importance in monitoring temperature; Utilization of layered manufacturing and rapid prototyping processes
Magneto hydrodynamic (MHD) pump fabricated with ceramic tapes
The use of Magneto Hydro Dynamics (MHD) to circulate fluids in conduits fabricated with low temperature co-fired ceramic tapes is described. Conduits shaped like toroidal and rectangular loops were fabricated. Electrodes printed on the ceramic substrate along the conduits\u27 walls facilitated transmission of electric currents through the test fluids. When the devices were subjected to a magnetic field, the resulting Lorentz forces propelled the liquids. The paper details the fabrication process and describes experiments with mercury slugs, saline solution, and deionized water. The measured fluid velocities were compared with theoretical predictions
A minute magneto hydro dynamic (MHD) mixer
A theoretical and experimental investigation of a magneto hydrodynamic stirrer is presented. Such a stirrer can be used to enhance mixing in micro total analysis systems. The stirrer utilizes arrays of electrodes deposited on a conduit\u27s walls. The conduit is filled with an electrolyte solution. By applying alternating potential differences across pairs of electrodes, currents are induced in various directions in the solution. In the presence of a magnetic field, the coupling between the magnetic and electric fields induces body (Lorentz) forces in the fluid. Since the electrodes can be patterned in various ways, fairly complex flow fields can be generated. In particular, in this paper, we describe the induction of cellular motion. This motion can be used to deform and stretch material interfaces and to enhance mixing. The MHD stirrer does not utilize any moving parts. The experimental observations are in good agreement with theoretical predictions
SLC29A1 single nucleotide polymorphisms as independent prognostic predictors for survival of patients with acute myeloid leukemia: an in vitro study
A Calculation Method and Its Application of Bus Isochrones
Bus isochrones indicate the maximum scale of bus system can extend during one time interval. A calculation method of isochrones is proposed in this paper and it can be applied to the analysis of public transport accessibility. The travel process by bus is analyzed and divided into five parts: walking to the bus stop from departure, waiting for buses, boarding buses, transfer and walking to the destination. Specific calculation methods of time cost are proposed for each part, respectively. Then, the isochrones are by the grid method and the inverse distance weighting method. The bus GPS data of Guangzhou, China is used to draw the isochrones maps and to demonstrate the Tee mall. Furthermore, the space-time accessibility is measured in the covering area of a unit time isochrones and the accessibility differences of different directions are then analyzed through profiles
miR-146a Expression Level as a Novel Putative Prognostic Marker for Acute Promyelocytic Leukemia
Background. Although the curative rate for acute promyelocytic leukemia (APL) has been improved over decades, long-term prognosis is still poor. The genetic pathways that regulated cell lineage fate during the development of APL remain unclear. Methods. We investigated the correlations of miR-146a expression with its target gene Smad4 and the biological behaviors of NB4 cells. We also analyzed their expression in clinical samples from APL patients. Results. miR-146a influenced apoptosis and proliferation in NB4 cells. miR-146a influenced endogenous Smad4 protein levels in APL cells. miR-146a expression levels were positively correlated with white cell counts and PML/RARα fusion protein expression. miR-146a expression levels were negatively correlated with Smad4 protein and the helper T cell (Th)/the suppressor T cell (Ts) ratio in these patients. Conclusions. These findings indicated that miR-146a played an important role in the development of APL in part through the repression on Smad4 protein expression. miR-146a functioned as an oncogene and may be a novel prognostic biomarker in APL
An Ensemble Successive Project Algorithm for Liquor Detection Using Near Infrared Sensor
Spectral analysis technique based on near infrared (NIR) sensor is a powerful tool for complex information processing and high precision recognition, and it has been widely applied to quality analysis and online inspection of agricultural products. This paper proposes a new method to address the instability of small sample sizes in the successive projections algorithm (SPA) as well as the lack of association between selected variables and the analyte. The proposed method is an evaluated bootstrap ensemble SPA method (EBSPA) based on a variable evaluation index (EI) for variable selection, and is applied to the quantitative prediction of alcohol concentrations in liquor using NIR sensor. In the experiment, the proposed EBSPA with three kinds of modeling methods are established to test their performance. In addition, the proposed EBSPA combined with partial least square is compared with other state-of-the-art variable selection methods. The results show that the proposed method can solve the defects of SPA and it has the best generalization performance and stability. Furthermore, the physical meaning of the selected variables from the near infrared sensor data is clear, which can effectively reduce the variables and improve their prediction accuracy
Correction: Relationship between LTR Methylation and gag Expression of HIV-1 in Human Spermatozoa and Sperm-Derived Embryos
OBJECTIVE: Studying the methylation status of long terminal repeats (LTR) and its relationship to gag expression of HIV-1 in order to explore regulation mechanism of HIV-1 gene expression in vertical transmission from sperm to embryo. METHODS/PRINCIPAL FINDINGS: Sperm samples were collected from a healthy donor and seven patients with HIV/AIDS. Zona-free hamster ova were fertilized by donor’s spermatozoa transfected with pIRES2-EGFP-LTR-gag and patient’s spermatozoa to obtain zygotes and 2-cell embryos, respectively. Interspecific in vitro fertilization, bisulfite sequencing PCR (BSP), RT-PCR, nested RT-PCR, nested real-time qRT-PCR and 2(−△△Ct) method, indirect immunofluoresence (IF) assay were performed. For donor’s samples, the methylation rates of HIV-1 LTR were 0.56%, 1.67%, 0.56%, 0.56% in plasmid, spermatozoa, zygotes and 2-cell embryos, respectively while spermatozoa were transfected with unmethylated plasmid, and were 95.0%, 84.44%, 3.3%, 1.67% while transfected with methylated plasmid. The positive bands for HIV-1 gag cDNA were detected in spermatozoa and 2-cell embryos. The positive signals for HIV-1 p24 Gag protein were detected in 2-cell embryos but not in spermatozoa. For patient’s samples, methylation rates of HIV-1 LTR were different in spermatozoa among patients. After fertilization, CpG sites in HIV-1 LTR were highly demethylated in zygotes and 2-cell embryos. The gag transcription levels increased with decreasing of methylation rates of HIV-1 LTR, which showed a strong negative correlations between gag transcription levels and methylation rates of HIV-LTR ether in the spermatozoa (r = −0.9877, P<0.0001) or in the sperm-derived 2-cell embryos (r = −0.9092, P = 0.0045). CONCLUSION: LTR methylation regulates expression of HIV-1 gag in vertical transmission from sperm to embryo
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