1,078 research outputs found
Di-μ-chlorido-bis{[2-(2-pyridylmethylamino)ethanesulfonato-κ3 N,N′,O]copper(II)}
In the title compound, [Cu2(C8H11N2O3S)2Cl2], the Cu atoms are five-coordinated in a distorted square-pyramidal geometry by three donor atoms of the deprotonated anionic 2-(2-pyridylmethylamino)ethanesulfonate (pmt) ligand and two Cl atoms. The Cl atoms bridge two Cu atoms, giving a binuclear structure; the centroid of the Cu2Cl2 ring lies on a crystallographic center of inversion. The complex is stabilized by hydrogen bonds and π–π stacking interactions [average interplanar distance = 3.4969 (1) Å and ring-centroid separation distance = 4.1068 (4) Å]
A study on the extraction and purification technology of tea sapogenin
In order to extract and purify tea sapogenin, first the extraction liquid is obtained using mechanically pressed tea-seeds as raw material, which will be decreased by organic solvent. When the conditions like the methanol volume fraction is 75v/v, solid-liquid is 1:4 and the ultrasonic frequency is 25.8 Hz, extract them for 30 min. After this, collect the extraction liquid and slowly add in Hz-841 macroporous resin column, then elute it with 0.3% NaOH. The third step is to elute with ethanol of different concentrations after the coloring pigment is got rid of, and then detect it with thin layer chromatography (TLC). It is discovered that there is only tea sapogenin in the 35 – 95v/v ethanol elution liquid. The last step is to collect the 95% ethanol elution liquid and vacuum condense it; and then tea-Tea sapogenin with a purity of 96% can be obtained
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Illuminating cell signaling with genetically encoded FRET biosensors in adult mouse cardiomyocytes.
FRET-based biosensor experiments in adult cardiomyocytes are a powerful way of dissecting the spatiotemporal dynamics of the complicated signaling networks that regulate cardiac health and disease. However, although much information has been gleaned from FRET studies on cardiomyocytes from larger species, experiments on adult cardiomyocytes from mice have been difficult at best. Thus the large variety of genetic mouse models cannot be easily used for this type of study. Here we develop cell culture conditions for adult mouse cardiomyocytes that permit robust expression of adenoviral FRET biosensors and reproducible FRET experimentation. We find that addition of 6.25 µM blebbistatin or 20 µM (S)-nitro-blebbistatin to a minimal essential medium containing 10 mM HEPES and 0.2% BSA maintains morphology of cardiomyocytes from physiological, pathological, and transgenic mouse models for up to 50 h after adenoviral infection. This provides a 10-15-h time window to perform reproducible FRET readings using a variety of CFP/YFP sensors between 30 and 50 h postinfection. The culture is applicable to cardiomyocytes isolated from transgenic mouse models as well as models with cardiac diseases. Therefore, this study helps scientists to disentangle complicated signaling networks important in health and disease of cardiomyocytes
Radiative transitions in charmonium from twisted mass lattice QCD
We present a study for charmonium radiative transitions:
, and
using twisted mass lattice QCD gauge
configurations. The single-quark vector form factors for and
are also determined. The simulation is performed at a lattice
spacing of fm and the lattice size is . After
extrapolation of lattice data at nonzero to 0, we compare our results
with previous quenched lattice results and the available experimental values.Comment: typeset with revtex, 15 pages, 11 figures, 4 table
Deep sequencing-based transcriptome profiling analysis of bacteria-challenged Lateolabrax japonicus reveals insight into the immune-relevant genes in marine fish
Microscopic resolution of superconducting electrons in ultrahigh-pressed hydrogen sulfide
We investigate the electronic and phonon properties of hydrogen sulfide
(SH) under ultrahigh pressure to elucidate the origin of its high-T
superconductivity. Contrary to the prevailing belief that the metalized S-H
bond is responsible, our analysis, based on the anisotropic
Migdal-Eliashberg equation and the crystal orbital Hamilton population (COHP)
calculation, reveals that the H-H -antibonding states play a dominant
role in the large electron-phonon coupling that leads to the superconducting
pairing in SH. Furthermore, by partially restricting the vibration of S
atoms, we demonstrate that the S-H bonds provide subsidiary contributions to
the pairing interaction. These findings shed light on the importance of the
previously overlooked H-H bonds in driving high-T
superconductivity in SH and offer insights into the relationship between
metallic H-H covalent antibonding and high-T superconductivity in other
hydrogen-rich materials under high pressure.Comment: 11 pages, 9 figures, 59 reference
Recombinant human insulin-like growth factor-1 promotes osteoclast formation and accelerates orthodontic tooth movement in rats
Background: IGF-1 may be an important factor in bone remodeling, but its mechanism of action on osteoclasts during orthodontic tooth movement is complex and unclear. Methodology: The closed-coil spring was placed between the left maxillary first molar and upper incisors with a force of 50 g to establish an orthodontic movement model. Eighty SD rats were randomized to receive phosphate buffer saline or 400 ng rhIGF-1 in the lateral buccal mucosa of the left maxillary first molar every two days. Tissue sections were stained for tartrate-resistant acidic phosphatase (TRAP), the number of TRAP-positive cells was estimated and tooth movement measured. Results: The rhIGF-1 group exhibited evidential bone resorption and lacuna appeared on the alveolar bone compared to the control group. Moreover, the number of osteoclasts in compression side of the periodontal ligament in the rhIGF-1 group peaked at day 4 (11.37±0.95 compared to 5.28±0.47 in the control group) after the orthodontic force was applied and was significantly higher than that of the control group (p<0.01). Furthermore, the distance of tooth movement in the rhIGF-1 group was significantly larger than that of the control group from day 4 to day 14 (p<0.01), suggesting that rhIGF-1 accelerated orthodontic tooth movement. Conclusion: Our study has showed that rhIGF-1 could stimulate the formation of osteoclasts in the periodontal ligament, and accelerate bone remodeling and orthodontic tooth movement
Emerging perceptions of teacher quality and teacher development in China
This paper focuses on the work of senior high school teachers in three representative local authority regions of mainland China. It discusses interview and focus group data collected as part of an ESRC/DfID-funded project which examined notions of quality as experienced by key stakeholders (national and local authority policy makers, teachers, head teachers and students). Building on previous international literature this paper gives a more nuanced understanding of quality and effectiveness in teaching by re-examining the dimensions of professional characteristics, classroom practice, school culture and classroom climate from the perceptions of Chinese teachers. Barriers to quality included changing societal patterns, the demands of curriculum reform, and common concerns with structural and funding constraints, which in poorer rural areas are typically reported to lead to low levels of teacher quality, shortages of specialised teachers and a lack of opportunity for good quality professional development
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