9 research outputs found
Direct, Rapid, Facile Photochemical Method for Preparing Copper Nanoparticles and Copper Patterns
We develop a facile method for preparing copper nanoparticles
and
patterned surfaces with copper stripes by ultraviolet (UV) irradiation
of a mixture solution containing a photoinitiator and a copper–amine
coordination compound. The copper–amine compound is formed
by adding diethanol amine to an ethanol solution of copper chloride.
Under UV irradiation, free radicals are generated by photoinitiator
decomposition. Meanwhile, the copper–amine coordination compound
is rapidly reduced to copper particles because the formation of the
copper–amine coordination compound prevents the production
of insoluble cuprous chloride. PolyÂ(vinylpyrrolidone) is used as a
capping agent to prevent the aggregation of the as-prepared copper
nanoparticles. The capping agent increases the dispersion of copper
nanoparticles in the ethanol solution and affects their size and morphology.
Increasing the concentration of the copper–amine coordination
compound to 0.1 M directly forms a patterned surface with copper stripes
on the transparent substrate. This patterned surface is formed through
the combination of the heterogeneous nucleation of copper nanoparticles
and photolithography. We also investigate the mechanism of photoreduction
by UV–vis spectroscopy and gas chromatography–mass spectrometry
Small-World Brain Network and Dynamic Functional Distribution in Patients with Subcortical Vascular Cognitive Impairment
<div><p>To investigate the topological properties of the functional connectivity and their relationships with cognition impairment in subcortical vascular cognitive impairment (SVCI) patients, resting-state fMRI and graph theory approaches were employed in 23 SVCI patients and 20 healthy controls. Functional connectivity between 90 brain regions was estimated using bivariate correlation analysis and thresholded to construct a set of undirected graphs. Moreover, all of them were subjected to a battery of cognitive assessment, and the correlations between graph metrics and cognitive performance were further analyzed. Our results are as follows: functional brain networks of both SVCI patients and controls showed small-world attributes over a range of thresholds(0.15≤sparsity≤0.40). However, global topological organization of the functional brain networks in SVCI was significantly disrupted, as indicated by reduced global and local efficiency, clustering coefficients and increased characteristic path lengths relative to normal subjects. The decreased activity areas in SVCI predominantly targeted in the frontal-temporal lobes, while subcortical regions showed increased topological properties, which are suspected to compensate for the inefficiency of the functional network. We also demonstrated that altered brain network properties in SVCI are closely correlated with general cognitive and praxis dysfunction. The disruption of whole-brain topological organization of the functional connectome provides insight into the functional changes in the human brain in SVCI.</p></div
The relationship between global network/nodal characteristics and CAMCOG-C scores/ of the praxis functional score patients with SVCI.
<p>CAMCOG-C:Cambridge cognitive examination-Chinese version. Cp = clustering coefficient; E<sub>glob</sub> = global efficiency.</p
The mean global small-world network metrics of brain networks in healthy controls (red) and patients SVCI (green) as a function of sparsity threshold.
<p>λ = normalized shortest path length, γ = normalized clustering coefficient, E<sub>glob</sub> = global efficiency, E<sub>loc</sub> = local efficiency.</p
Demographic and neuropsychological data.
<p>Data are presented as mean ±SD. MMSE = Mini-Mental State Examination. CAMCOG-C = Cambridge cognitive examination-Chinese version;ADL = Activities of Daily Living Scale; GDS = Global deterioration scale; MoCA = Montreal Cognitive Assessment, CDR = Clinical Dementia Rating; AVLT = Auditory-Verbal Learning Test;WMH = white matter hyperintensities</p><p><sup>a</sup> two-tail Pearson chi-square test</p><p><sup>b</sup> were obtained using a two-sample two-tail t-test.</p><p>Demographic and neuropsychological data.</p
Significant differences in all metrics between SVIC patients and controls in the range of 0.05 ≤ S<sub>thr</sub> ≤ 0.40.
<p>t, statistical value showing nodal topological properties difference (P < 0.05,FDR corrected) between two groups (positive t-value means increased topological properties in the SVCI group); DCG: median cingulate and paracingulate gyri; R, right; L, left.</p><p>Significant differences in all metrics between SVIC patients and controls in the range of 0.05 ≤ S<sub>thr</sub> ≤ 0.40.</p
Distribution of brain regions in which small-world properties decreased(blue) or increased(red) significantly in SVCI patients compared to the healthy controls over a wide range of correlation thresholds (0.05
<p>(A) global efficiency; (B) clustering coefficient; (C) characteristic path length; (D) local efficiency; DCG = median cingulate and paracingulate gyri; MTG = middle temporal gyrus; PUT = putamen; PAL = pallidum; TPOsup = temporalpole: superior temporal gyrus; STG = superior temporal gyrus; SMA = supplementary motor area; PCUN = Precuneus; PoCG = postcentral gyrus; OLF = Olfactory cortex; PCL = paracentral lobule; IOG = Inferior occipital gyrus</p
Flower-like Surface of Three-Metal-Component Layered Double Hydroxide Composites for Improved Antibacterial Activity of Lysozyme
Microbes
play an important function in our lives, while some pathogenic
bacteria are responsible for many infectious diseases, food safety,
and ecological pollution. Layered double hydroxide (LDH) is a kind
of natural two-dimensional material and has been applied in many fields.
Lysozyme is a green natural antibacterial agent, while the antimicrobial
activity of lysozyme is not as good as antibiotics. We use a different
ratio of cations to tune the morphology of LDH covered with lysozyme
to enhance the antibacterial ability of lysozyme. We synthesize MgAl-LDH,
ZnAl-LDH, and ZnMgAl-LDH covered with lysozyme, characterize the structure
and morphology, test the antibacterial in culture media, and evaluate
the biotoxicity in vitro and in vivo. The flower-like structure of
ZnMgAl-LDH has a rough surface, covered with lysozyme with a perfect
ring, and presents good antibaterial properties and promotes wound
healing of mice. The bloom flower structure of ZnMgAl-LDH can enhance
the loading rate of lysozyme; meanwhile, the rougher surface can adhere
more bacteria, so lyso@ZnMgAl-LDH presents better antibacterial activity
than the binary LDHs
Facile Method for the Fabrication of Robust Polyelectrolyte Multilayers by Post-Photo-Cross-Linking of Azido Groups
In this letter, we have developed a facile method to
enhance the
stability of polyelectrolyte multilayers. We fabricate conventional
polyelectrolyte multilayers of PAH/PAA through electrostatic layer-by-layer
(LbL) assembly and then postinfiltrate photosensitive cross-linking
agent 4,4′-diazostilbene-2,2′-disulfonic acid disodium
salt into the LbL films. After cross-linking by UV irradiation, the
stability of the photo-cross-linked multilayer is highly improved
as evidenced by the lack of dissolution under ultrasonication in saturated
SDS aqueous solutions for 10 min. Moreover, by taking advantage of
the different stability of the LbL film before and after UV irradiation,
a patterned surface can be achieved