7,816 research outputs found
Silicon carbide and other films and method of deposition
A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties
Sulforaphane induces adipocyte browning and promotes glucose and lipid utilization
Scope: Obesity is closely related to the imbalance of white adipose tissue storing excess calories, and brown adipose tissue dissipating energy to produce heat in mammals. Recent studies revealed that acquisition of brown characteristics by white adipocytes, termed “browning,” may positively contribute to cellular bioenergetics and metabolism homeostasis. The goal was to investigate the putative effects of natural antioxidant sulforaphane (1-isothiocyanate-4-methyl-sulfonyl butane; SFN) on browning of white adipocytes. Methods and Results: 3T3-L1 mature white adipocytes were treated with SFN for 48 h, and then the mitochondrial content, function, and energy utilization were assessed. SFN was found to induce 3T3-L1 adipocytes browning based on the increased mitochondrial content and activity of respiratory chain enzymes, whereas the mechanism involved the upregulation of nuclear factor E2-related factor 2/ sirtuin1/ peroxisome proliferator-activated receptor gamma coactivator 1 alpha signaling. SFN enhanced uncoupling protein 1 expression, a marker for brown adipocyte, leading to the decrease in cellular ATP. SFN also enhanced glucose uptake and oxidative utilization, lipolysis and fatty acid oxidation in 3T3-L1 adipocytes. Conclusion: SFN-induced browning of white adipocytes enhanced the utilization of cellular fuel, and the application of SFN is a promising strategy to combat obesity and obesity-related metabolic disorder
Measurement to radius of Newton’s ring fringes using polar coordinate transform
Background: Newton’s ring method is often used to measure many physical parameters. And some measured physical quantity can be extracted by calculating the radius parameter of circular fringes from Newton's ring configuration.
Methods: The paper presents a new measuring method for radius of circular fringes, which includes three main steps, i.e., determination of center coordinates of circular fringes, polar coordinates transformation of circular fringes, and gray projection of the transformed result which along the horizontal direction. Then the radius values of each order ring are calculated.
Results: The simulated results indicate that the measuring accuracy of the radius under the effect of random noise can keep the degree of less than 0.5 pixels.
Conclusions: The proposed method can obtain the radius data of each order closed circular fringes. Also, it has several other advantages, including ability of good anti-noise, sub-pixel accuracy and high reliability, and easy to in-situ use
Composition Comprising Silicon Carbide
A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties
Effects of aminoguanidine on retinal apoptosis in mice with oxygen-induced retinopathy
<b>AIM:</b> To explore the protective effects of aminoguanidine (AG) on retinal apoptosis in mice with oxygen-induced retinopathy (OIR).<b>METHODS</b>:A total of 80 C57BL/6J mice, aged 7 days, were randomly divided into four groups:normal, high oxygen, high oxygen saline and high oxygen treated with AG. In the normal group, mice were housed in normoxic conditions from postnatal day P7 to P17. Mice in the other 3 groups were placed under hyperoxic conditions (75±2%O2) in an oxygen-regulated chamber for 5 days and subsequently placed in normoxic conditions for 5 days. Mice in the AG group were treated once daily, from P12 to P17, with AG hemisulfate (100mg/kg body weight, intraperitoneally) dissolved in physiological saline. An equivalent amount of 0.9% physiological saline was administered, as above, to mice in the high oxygen saline group. Ten mice were randomly selected from each group on P14 and on P17, euthanized and the retinas examined. Apoptotic cells in the retina were detected using the terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. The expression of nitric oxide synthase (iNOS) in the retina was detected by immunohistochemistry and changes in rod cells were observed using electron microscopy.<b>RESULTS</b>:TUNEL-positive cells and iNOS immunoreactive neurons were present in the inner nuclear and ganglion cell retinal layers of mice in the high oxygen group. The number of TUNEL-positive cells was significantly greater in the high oxygen group compared with the normal group (<i>t</i>=-20.81, <i>P</i>14d <0.05; <i>t</i>=-15.05, <i>P</i>17d<0.05). However, the number of TUNEL-positive cells in the AG treatment group was significantly lower (<i>t</i>=-13.21, <i>P</i>14d<0.05; <i>t</i>=-6.61,<i>P</i>17d <0.05) compared with the high oxygen group. The expression of iNOS was significantly higher in the high oxygen group compared with the normal group (<i>t</i>=-21.95, <i>P</i>14d<0.05; <i>t</i>=-17.30, <i>P</i>17d<0.05). However, the expression of iNOS in the AG treatment group was significantly lower (<i>t</i>=-12.17,<i>P</i>14d<0.05; <i>t</i>=-10.30,<i>P</i>17d<0.05) compared with the high oxygen group. The outer segments of the rods were disorganized and short in the high oxygen group. Rod morphology appeared to be slightly improved in the AG group.<b>CONCLUSION</b>:AG may protect retinal neurons in OIR by inhibiting apoptosis. The mechanism may be related to iNOS
Superconductivity in undoped CaFe2As2 single crystals
Single crystals of undoped CaFe2As2 were grown by a FeAs self-flux method,
and the crystals were quenched in ice-water rapidly after high temperature
growth. The quenched crystal undergoes a collapsed tetragonal structural phase
transition around 80 K revealed by the temperature dependent X-ray diffraction
measurements. Superconductivity below 25 K was observed in the collapsed phase
by resistivity and magnetization measurements. The isothermal magnetization
curve measured at 2 K indicates that this is a typical type-II superconductor.
For comparison, we systematically characterized the properties of the furnace
cooled, quenched, and post-annealed single crystals, and found strong internal
crystallographic strain existing in the quenched samples, which is the key for
the occurrence of superconductivity in the undoped CaFe2As2 single crystals
Loop-Mediated Isothermal Amplification Assay Targeting the MOMP Gene for Rapid Detection of Chlamydia psittaci Abortus Strain
For rapid detection of the Chlamydia psittaci abortus strain, a loop-mediated isothermal amplification (LAMP) assay was developed and evaluated in this study. The primers for the LAMP assay were designed on the basis of the main outer membrane protein (MOMP) gene sequence of C. psittaci. Analysis showed that the assay could detect the abortus strain of C. psittaci with adequate specificity. The sensitivity of the test was the same as that of the nested-conventional PCR and higher than that of chick embryo isolation. Testing of 153 samples indicated that the LAMP assay could detect the genome of the C. psittaci abortus strain effectively in clinical samples. This assay is a useful tool for rapid diagnosis of C. psittaci infection in sheep, swine and cattle
Extensive tRNA gene changes in synthetic Brassica napus
Allopolyploidization, where two species come together to form a new species, plays a major role in speciation and genome evolution. Transfer RNAs (abbreviated tRNA) are typically 73-94 nucleotides in length, and are indispensable in protein synthesis, transferring amino acids to the cell protein synthesis machinery (ribosome). To date, the regularity and function of tRNA gene sequence variation during the process of allopolyploidization have not been well understood. In this study, the inter-tRNA gene corresponding to tRNA amplification polymorphism method was used to detect changes in tRNA gene sequences in the progeny of interspecific hybrids between Brassica rapa and B. oleracea, mimicking the original B. napus (canola) species formation event. Cluster analysis showed that tRNA gene variation during allopolyploidization did not appear to have a genotypic basis. Significant variation occurred in the early generations of synthetic B. napus (F and F generations), but fewer alterations were observed in the later generation (F). The variation-prone tRNA genes tended to be located in AT-rich regions. BlastN analysis of novel tRNA gene variants against a Brassica genome sequence database showed that the variation of these tRNA-gene-associated sequences in allopolyploidization might result in variation of gene structure and function, e.g., metabolic process and transport
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