208 research outputs found
4-Bromo-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-5-(4-nitrobenzylideneamino)-1H-pyrazole-3-carbonitrile
The title compound, C18H7BrCl2F3N5O2, is an L-shaped tricyclic imine. The pyrazole ring is essentially coplanar with the nitro-substituted benzene ring [dihedral angle = 3.6 (2)°] and approximately perpendicular to the trifluoromethylsubstituted ring [dihedral angle = 88.5 (2)°]
4-Bromo-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-5-(4-methoxybenzylideneamino)-1H-pyrazole-3-carbonitrile
The title compound, C19H10BrCl2F3N4O, is an imine with an overall Y shape. The dihedral angles between the pyrazole ring and the methoxy- and trifluoromethyl-substituted benzene ring planes are 88.4 (2) and 65.8 (2)°, respectively
Electrified Fracture of Nanotube Films
Strong and conductive carbon nanotube films are ideal candidates for
lightning-strike protection. Understanding their failure mechanisms by
considering the anisotropic and single-fiber nature is essential to improve
performance. Our experimental studies show that the single-layer,
nanometer-thick films fail under electrification by crack nucleation and
propagation, reminiscent of brittle and ductile fracture of materials under
mechanical loads. Sharp and diffuse patterns of fracture are identified in
aligned and non-woven films, respectively, signaling the strong effect of
material anisotropy that is absent in common engineering materials. The
fracture is driven by local Joule heating concentrated at the crack fronts
instead of force-induced breakage, which is validated by experimental
characterization and simulation results at both continuum and atomistic levels
Magnetic-field-induced splitting of Rydberg Electromagnetically Induced Transparency (EIT) and Autler-Townes (AT) spectra in Rb vapor cell
We theoretically and experimentally investigate the Rydberg
electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting
of Rb vapor under the combined influence of a magnetic field and a
microwave field. In the presence of static magnetic field, the effect of the
microwave field leads to the dressing and splitting of each state,
resulting in multiple spectral peaks in the EIT-AT spectrum. A simplified
analytical formula was developed to explain the EIT-AT spectrum in a static
magnetic field, and the calculations are in excellent agreement with
experimental results.We further studied the enhancement of the Rydberg atom
microwave electric field sensor performance by making use of the splitting
interval between the two maximum absolute states under static magnetic
field. The traceable measurement limit of weak electric field by EIT-AT
splitting method was extended by an order of magnitude, which is promising for
precise microwave electric field measurement.Comment: 12 pages, 4 figure
Microwave electrometry with Rydberg atoms in a vapor cell using microwave amplitude modulation
We have theoretically and experimentally studied the dispersive signal of the
Rydberg atomic electromagnetically induced transparency (EIT) - Autler-Townes
(AT) splitting spectra obtained using amplitude modulation of the microwave
(MW) field. In addition to the two zero-crossing points, the dispersion signal
has two positive maxima with an interval defined as the shoulder interval of
the dispersion signal . The relationship of MW field
strength and are studied at the MW
frequencies of 31.6 GHz, 22.1 GHz, and 9.2 GHz respectively. The results show
that can be used to character the much weaker
than the interval of two zero-crossing points and the traditional EIT-AT splitting interval , the minimum measured by
is about 30 times smaller than that by . As an example,
the minimum at 9.2 GHz that can be characterized by is 0.056 mV/cm, which is the minimum value characterized by
frequency interval using vapour cell without adding any auxiliary fields. The
proposed method can improve the weak limit and sensitivity of
measured by spectral frequency interval, which is important in the direct
measurement of weak
Tackling environmental challenges in pollution controls using artificial intelligence: A review
Hesperidin Protects against Acute Alcoholic Injury through Improving Lipid Metabolism and Cell Damage in Zebrafish Larvae
Alcoholic liver disease (ALD) is a series of abnormalities of liver function, including alcoholic steatosis, steatohepatitis, and cirrhosis. Hesperidin, the major constituent of flavanone in grapefruit, is proved to play a role in antioxidation, anti-inflammation, and reducing multiple organs damage in various animal experiments. However, the underlying mechanism of resistance to alcoholic liver injury is still unclear. Thus, we aimed to investigate the protective effects of hesperidin against ALD and its molecular mechanism in this study. We established an ALD zebrafish larvae model induced by 350 mM ethanol for 32 hours, using wild-type and transgenic line with liver-specific eGFP expression Tg (lfabp10α:eGFP) zebrafish larvae (4 dpf). The results revealed that hesperidin dramatically reduced the hepatic morphological damage and the expressions of alcohol and lipid metabolism related genes, including cyp2y3, cyp3a65, hmgcra, hmgcrb, fasn, and fads2 compared with ALD model. Moreover, the findings demonstrated that hesperidin alleviated hepatic damage as well, which is reflected by the expressions of endoplasmic reticulum stress and DNA damage related genes (chop, gadd45αa, and edem1). In conclusion, this study revealed that hesperidin can inhibit alcoholic damage to liver of zebrafish larvae by reducing endoplasmic reticulum stress and DNA damage, regulating alcohol and lipid metabolism
Three-dimensional digital atlas construction of Chinese brains by magnetic resonance imaging
This paper describes the construction of an atlas of the human brain by magnetic resonance imaging. The successive steps of the construction were performed with images acquired by three-dimensional fast spoiled gradient-echo recalled acquisition sequences in 1.5T. Data from the young and middle-aged healthy volunteers were spatially normalized into MNI coordinate frame in SPM2 software based on MATLAB. Three-dimensional brain atlas were reconstructed in the MNI coordinate system. There atlases enable efficient structure localization and morphometric comparison, which play important roles in the computer aided surgery, image guide surgery minimal invasive surgery and other frontier areas
An atlas of DNA methylomes in porcine adipose and muscle tissues
It is evident that epigenetic factors, especially DNA methylation, have essential roles in obesity development. Here, using pig as a model, we investigate the systematic association between DNA methylation and obesity. We sample eight variant adipose and two distinct skeletal muscle tissues from three pig breeds living within comparable environments but displaying distinct fat level. We generate 1,381 Gb of sequence data from 180 methylated DNA immunoprecipitation libraries, and provide a genome-wide DNA methylation map as well as a gene expression map for adipose and muscle studies. The analysis shows global similarity and difference among breeds, sexes and anatomic locations, and identifies the differentially methylated regions. The differentially methylated regions in promoters are highly associated with obesity development via expression repression of both known obesity-related genes and novel genes. This comprehensive map provides a solid basis for exploring epigenetic mechanisms of adipose deposition and muscle growth
Pretreatment Donors after Circulatory Death with Simvastatin Alleviates Liver Ischemia Reperfusion Injury through a KLF2-Dependent Mechanism in Rat
Objective. Severe hepatic ischemia reperfusion injury (IRI) can result in poor short- and long-term graft outcome after transplantation. The way to improve the viability of livers from donors after circulatory death (DCD) is currently limited. The aim of the present study was to explore the protective effect of simvastatin on DCD livers and investigate the underlying mechanism. Methods. 24 male rats randomly received simvastatin or its vehicle. 30 min later, rat livers were exposed to warm ischemia in situ for 30 min. Livers were removed and cold-stored in UW solution for 24 h, subsequently reperfused for 60 min with an isolated perfused rat liver system. Liver injury was evaluated during and after warm reperfusion. Results. Pretreatment of DCD donors with simvastatin significantly decreased IRI liver enzyme release, increased bile output and ATP, and ameliorated hepatic pathological changes. Simvastatin maintained the expression of KLF2 and its protective target genes (eNOS, TM, and HO-1), reduced oxidative stress, inhibited innate immune responses and inflammation, and increased the expression of Bcl-2/Bax to suppress hepatocyte apoptosis compared to DCD control group. Conclusion. Pretreatment of DCD donors with simvastatin improves DCD livers’ functional recovery probably through a KLF2-dependent mechanism. These data suggest that simvastatin may provide a potential benefit for clinical DCD liver transplantation
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