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排序方式: 共有105条查询结果,搜索用时 15 毫秒
1.
为了解妇女妊娠中期营养状况,对1996年产科门诊采集的杂结果进行回顾性分析,结果表明,孕中期妇女有59.64%存在宏量和微量元素缺乏,其中钙缺乏占首位,铁缺乏占第二位,锌缺乏占第三位,镁变化不大。缺钙严重程度与季节有关。提示孕中期应对孕妇给予膳食结构的调整,适时补充营养和钙,以满足母胎之需要,减少母儿并发症。 相似文献
2.
3.
王利光 《原子与分子物理学报》2013,30(6)
利用第一性原理的密度泛函理论和非平衡格林函数的方法研究了C74分子的分子轨道密度、振动光谱和态密度。结果显示C74分子的能隙0.6eV。比较C74分子的电子云分布发现,在HOMO和LUMO状态下的电子只分布在C74分子的半球表面侧,电子在成键过程中都表现出了较好的离域特性。C74分子的红外光谱和拉曼光谱显示,碳碳键的振动在有些频率处只有红外活性,有些频率处只有拉曼活性,还有一些频率处既有红外又有拉曼活性。另外,考虑电子自旋作用时C74分子态密度的极大值数量有所增加,并使简并的能级发生分裂。 相似文献
4.
Hongyu Zhang Changlong Hao Aihua Qu Maozhong Sun Liguang Xu Chuanlai Xu Hua Kuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7197-7204
The accumulation and deposition of β-amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d -FexCuySe nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d -FexCuySe NPs have a much higher affinity for Aβ42 fibrils than l -FexCuySe NPs and chiral Cu2−xSe NPs. The chiral FexCuySe NPs also generate more reactive oxygen species (ROS) than chiral Cu2−xSe NPs under NIR-light irradiation. In living MN9D cells, d -NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d -FexCuySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence. 相似文献
5.
Hongyu Zhang Changlong Hao Aihua Qu Maozhong Sun Liguang Xu Chuanlai Xu Hua Kuang 《Angewandte Chemie (International ed. in English)》2020,59(18):7131-7138
The accumulation and deposition of β‐amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d ‐FexCuySe nanoparticles (NPs) were fabricated that interfer with the self‐assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near‐infrared (NIR) illumination. d ‐FexCuySe NPs have a much higher affinity for Aβ42 fibrils than l ‐FexCuySe NPs and chiral Cu2?xSe NPs. The chiral FexCuySe NPs also generate more reactive oxygen species (ROS) than chiral Cu2?xSe NPs under NIR‐light irradiation. In living MN9D cells, d ‐NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In‐vivo experiments showed that d ‐FexCuySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence. 相似文献
6.
7.
In this paper,the authors characterize the inhomogeneous Triebel-Lizorkin spaces Fp,q s,w(Rn)with local weight w by using the Lusin-area functions for the full ranges of the indices,and then establish their atomic decompositions for s ∈ R,p ∈(0,1] and q ∈ [p,∞).The novelty is that the weight w here satisfies the classical Muckenhoupt condition only on balls with their radii in(0,1].Finite atomic decompositions for smooth functions in Fp,q s,w(Rn)are also obtained,which further implies that a(sub)linear operator that maps smooth atoms of Fp,q s,w(Rn)uniformly into a bounded set of a(quasi-)Banach space is extended to a bounded operator on the whole Fp,q s,w(Rn).As an application,the boundedness of the local Riesz operator on the space Fp,q s,w(Rn)is obtained. 相似文献
8.
A novel water-soluble heptaplatin analogue, cis-[(4R,5R)-4,5-bis-(aminomethyl)-2-isopropyl-1,3-dioxolane](3-hydroxy-1,1-cyclobutanedicarboxylato)platinum(II), has been synthesized and biologically evaluated. The complex shows more activity and less toxicity than its parent drug heptaplatin, exhibiting the great potential for further development. 相似文献
9.
Let dγ(x) ≡ π
−n/2
e
−|x|
2
dx for all x ∈ ℝ
n
be the Gauss measure on ℝ
n
. In this paper, the authors establish the characterizations of the space BMO(γ) of Mauceri and Meda via commutators of either local fractional integral operators or local fractional maximal operators.
To this end, the authors first prove that such a local fractional integral operator of order β is bounded from L
p
(γ) to L
p/(1−pβ)(γ), or from the Hardy space H
1(γ) of Mauceri and Meda to L
1/(1−β)(γ) or from L
1/β
(γ) to BMO(γ), where β ∈ (0, 1) and p ∈ (1, 1/β). 相似文献
10.
Yanmei Li Lei Zhao Xiaolei Huang Liguang Zhang Jingjing Li Jian Zhang 《Journal of separation science》2019,42(24):3697-3702
Fish oils are rich in eicosapentaenoic acid, which has the wide‐ranging biological activities. The rapid and efficient separation of eicosapentaenoic acid ethyl ester from fish oils ethyl ester is still regarded as a challenge. In this study, we described an effective and flexible chromatography for eicosapentaenoic acid ethyl ester preparation, named continuous batch chromatography, which combined the batch chromatography with the continuous chromatographic operation mode. After continuous batch chromatography experiment, the recovery of eicosapentaenoic acid ethyl ester was 82.01%, the average relative purity and the relative highest purity of eicosapentaenoic acid ethyl ester were 97.82 and 98.98%. The productivity of continuous batch chromatography was 5.48 times higher than that of batch chromatography, while the solvent consumption of eicosapentaenoic acid ethyl ester was 78% of the batch chromatography. This study provided a reference for the separation of the targeted chemical component from multi‐component mixtures. 相似文献