This study was conducted to prepare β-caryophyllene loaded liposomes (BCP-LP) and investigated their effects on neurovascular unit (NVU) damage after subarachnoid hemorrhage (SAH) in rats. A blood ...injection into the pre-chiasmatic cistern was used to achieve SAH. BCP-LP were prepared, characterized and administrated to rats with SAH. The prepared BCP-LP were spherical with a size distribution of approximately 189.3 nm and Zeta potential of − 13.9 mV. Neurological scoring, the balance beam test, cerebral blood flow monitoring, brain edema and biochemical analyses were applied to evaluate the effects of BCP-LP on rat NVU damage after SAH. The results demonstrated that BCP-LP treatment improved neurological function disorder, balance ability and cerebral blood perfusion in rats. Brain edema detection and blood–brain barrier permeability detection revealed that BCP-LP could reduce brain edema and promote repairment of blood–brain barrier after SAH. Using the western blot experiments, we demonstrated that BCP-LP attenuated the loss of tight junction proteins Occludin and Zonula occludens-1, inhibit the high expression of VEGFR-2 and GFAP, and promote the repair of laminin. These results demonstrate the protective effect BCP-LP exert in the NVU after SAH in rats, and supports the use of BCP-LP for future study and therapy of SAH.
This study involved the preparation and characterization of in situ (TiC-TiB
)/Al-4.7Cu-0.32Mg-0.44Si composites with excellent mechanical and abrasive wear properties. The composites were ...synthesized in an Al-Ti-B
C system by combining combustion reaction synthesis with hot-pressed sintering and hot extrusion. The in situ TiB
and TiC particles were of multi-scaled sizes ranging from 20 nm to 1.3 μm. The TiB
and TiC particles effectively increased the yield strength (
), ultimate tensile strength (
), hardness (HV), and abrasive wear resistance of the composites. The 40 wt.% (TiC-TiB
)/Al-4.7Cu-0.32Mg-0.44Si composite exhibited the highest
(569 MPa),
(704 MPa) and hardness (286 HV), which were 74%, 51% and 110% higher than those of the matrix alloy, respectively. Compared with the matrix alloy, the abrasive wear resistance of the 40 wt.% (TiC-TiB
)/Al-4.7Cu-0.32Mg-0.44Si composite was increased by 4.17 times under an applied load of 5 N and Al
O
abrasive particle size of 13 µm. Micro-ploughing and micro-cutting were the main abrasive wear mechanisms for the Al-Cu-Mg-Si alloy and the composites.
Metal-catalyzed reductive amination of formyl-containing linkers with
N
,
N
-dialkylformamide solvents is concomitant with the solvothermal coordination assembly, leading to novel MOFs functionalized ...with tertiary aliphatic amino groups. This illustrates a novel one-pot strategy to functionalize MOFs through
in situ
organic transformation. The UiO-66 MOFs partially functionalized with the amino groups are highly active heterogeneous catalysts for Knoevenagel condensation.
Some artists peel citrus fruits into a variety of elegant 2D shapes, depicting animals, plants, and cartoons. It is a creative art form, called
Citrus Peeling Art.
This art form follows the ...conservation principle, i.e., each shape must be created using one entire peel. Central to this art is finding optimal cut lines so that the citruses can be cut and unfolded into the desired shapes. However, it is extremely difficult for users to imagine and generate cuts for their desired shapes. To this end, we present a computational method for citrus peeling art designs. Our key insight is that instead of solving the difficult cut generation problem, we map a designed input shape onto a citrus in an attempt to cover the entire citrus and use the mapped boundary to generate the cut paths. Sometimes, a mapped shape is unable to completely cover a citrus. Consequently, we have developed five customized ways of interaction that are used to rectify the input shape so that it is suitable for citrus peeling art. The mapping process and user interactions are iteratively conducted to satisfy a user's design intentions. A large number of experiments, including a formative user study, demonstrate the capability and practicability of our method for peeling art design and construction.
Catalytic asymmetric 1,2-allylation of aurone-derived azadienes is very difficult to achieve due to the driving force for aromatization and the greater steric hindrance of 1,2-addition compared with ...1,4-addition. By taking advantage of the ability of nitrogen ligated metal complexes, we successfully demonstrated the first example of copper-catalyzed 1,2-allylation of azadienes with allylboronates for the highly enantioselective synthesis of homoallylic amines. Meanwhile, the enantioenriched 1,4-addition products could also be obtained through a subsequent 3,3-sigmatropic rearrangement of the 1,2-addition products. Extensive DFT calculations were carried out to elucidate the origins of high regioselectivity (1,2- vs 1,4-) and enantioselectivity.
Two fluorescent probes, Y1-2 were synthesized from 2-acetonaphthone, 4-acetylbiphenyl, and phenyl hydrazine by Vilsmeier-Haack reaction and Knoevenagel condensation. Their recognition efficacies for ...N2H4 were tested by UV-visible absorption spectroscopy and fluorescence emission spectroscopy. The recognition mechanism were studies by density-functional theory calculations, and the effect of pH on N2H4 recognition was also studied. The results showed that the probe Y1-2 has high selectivity and a low detection limit for N2H4, and the recognition of N2H4 can be accomplished at physiological pH. The probes have had obvious aggregation-induced luminescence effect, large Stokes shift, high sensitivity, and can be successfully applied to live cell imaging.
The thermal expansion behavior of sintered Nd–Fe–B magnets is a crucial parameter for production and application. However, this aspect has not been thoroughly investigated. In this study, three ...different sintered Nd–Fe–B magnets with varying Co content (Co = 0, 6, 12 wt%) were prepared using the conventional powder metallurgy method, and four magnets oriented under different magnetic fields were prepared to compare. The thermal expansion behavior for the magnets was investigated using a linear thermal dilatometry in the temperature range of 20 °C–500 °C. It was found that, the coefficient of thermal expansion (CTE) increases with the increase of Co contents, while the anisotropy of thermal expansion decreases. The introduction of Co leads to continuous changes from negative to positive thermal expansion in the vertically oriented direction, which is important for the development of zero thermal expansion magnets. The thermal expansion of non-oriented magnets was found to be isotropic. Additionally, the anisotropy of thermal expansion increases with the increase of orientation degree. These results have important implications for the development of sintered Nd–Fe–B with controllable CTE.
A novel avian infectious bronchitis virus (IBV) variant, designated as GX-NN160421, was isolated from vaccinated chicken in Guangxi, China, in 2016. Based on analysis of the S1 gene sequence, ...GX-NN160421 belonged to the New-type 1 (GVI-1) strain. More importantly, three consecutive nucleotides (AAC) deletions were found in the highly conserved structure gene N. The serotype of GX-NN160421 was different from those of the commonly used vaccine strains. The mortality of the GX-NN160421 strain was 3.33%, which contrasted with 50% mortality in the clinical case, but high levels of virus shedding lasted at least 21 days. In conclusion, the first novel IBV variant with three-nucleotide-deletion in the N gene was identified, and this unique variant is low virulent but with a long time of virus shedding, indicating the continuing evolution of IBV and emphasizing the importance of limiting exposure to novel IBV strains as well as extensive monitoring of new IBVs.
A nickel-catalyzed three-component alkylarylation of alkenyl N-heteroarenes with α-bromocarboxylates and aryl boronic acids is reported. The protocol provides a new method to access a variety of ...N-heteroarene substituted diarylalkanes in moderate to good yields. It features mild reaction conditions, cheap nickel catalyst, readily available substrates, and broad substrate scope.
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