A facile method to achieve a stable collagen coating on a titanium alloy was put forward to promote the integration between a percutaneous implant and soft tissue.

No abstract

Percutaneous or transcutaneous devices are important and unique, and the corresponding biological sealing at the skin-implant interface is the key to their long-term success. Herein, we investigated the surface modification...

Objective: To investigate variation in the characteristics of regional cerebral blood flow (rCBF), brain activity, and intrinsic functional connectivity (FC) across the Alzheimer's disease spectrum (ADS).Methods: The study recruited 20 individuals in each of the following categories: Alzheimer's disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD), and healthy control (HC). All participants completed the 3.0T resting-state functional MRI (rs-fMRI) and arterial spin labeling scans in addition to neuropsychological tests. Additionally, the normalized CBF, regional homogeneity (ReHo), and amplitude of low-frequency fluctuation (ALFF) of individual subjects were compared in the ADS. Moreover, the changes in intrinsic FC were investigated across the ADS using the abnormal rCBF regions as seeds and behavioral correlations. Finally, a support-vector classifier model of machine learning was used to distinguish individuals with ADS from HC.Results: Compared to the HC subjects, patients with AD showed the poorest level of rCBF in the left precuneus (LPCUN) and right middle frontal gyrus (RMFG) among all participants. In addition, there was a significant decrease in the ALFF in the bilateral posterior cingulate cortex (PCC) and ReHo in the right PCC. Moreover, RMFG- and LPCUN-based FC analysis revealed that the altered FCs were primarily located in the posterior brain regions. Finally, a combination of altered rCBF, ALFF, and ReHo in posterior cingulate cortex/precuneus (PCC/PCUN) showed a better ability to differentiate ADS from HC, AD from SCD and MCI, but not MCI from SCD.Conclusions: The study demonstrated the significance of an altered rCBF and brain activity in the early stages of ADS. These findings, therefore, present a potential diagnostic neuroimaging-based biomarker in ADS. Additionally, the study provides a better understanding of the pathophysiology of AD.

No abstract

Suicide ideation (SI) is a most high-risk clinical sign for major depressive disorder (MDD). However, whether the rich-club network organization as a core structural network is associated with SI and how the related neural circuits are distributed in MDD patients remain unknown. Total 177 participants including 69 MDD patients with SI (MDDSI), 58 MDD without SI (MDDNSI) and 50 cognitively normal (CN) subjects were recruited and completed neuropsychological tests and diffusion-tensor imaging scan. The rich-club organization was identified and the global and regional topological properties of structural networks, together with the brain connectivity of specific neural circuit architectures, were analyzed. Further, the support vector machine (SVM) learning was applied in classifying MDDSI or MDDNSI from CN subjects. MDDSI and MDDNSI patients both exhibited disrupted rich-club organizations. However, MDDSI patients showed that the differential network was concentrated on the non-core low-level network and significantly destroyed betweeness centrality was primarily located in the regional non-hub regions relative to MDDNSI patients. The differential structural network connections involved the superior longitudinal fasciculus and the corpus callosum were incorporated in the cognitive control circuit and default mode network. Finally, the feeder serves as a potentially powerful indicator for distinguishing MDDSI patients from MDDNSI or CN subjects. The altered rich-club organization provides new clues to understand the underlying pathogenesis of MDD patients, and the feeder was useful as a diagnostic neuroimaging biomarker for differentiating MDD patients with or without SI.

No abstract

Since the pioneering work of Messersmith’s group discovering that polydopamine (PDA) can serve to adhere to many types of materials, the PDA coating has, as a biomimetic approach, been widely used to enhance cell adhesion by surface modification to bind biologically active substances to a bioinert substrate. Nevertheless, it is unclear whether or not the PDA itself is beneficial for cells. Herein, we report that a PDA coating decreases viability of cells under normal culture and observation conditions. Such an inhibition effect was not caused by the free PDA or any inherent cytotoxicity of this chemical substance but a contact-dependent phenomenon. Human bone marrow mesenchymal stem cells were employed as the default cell type and tissue culture plates were used as the default substrate, although some other cell types and substrates were also examined to confirm the universality of such an “abnormal” phenomenon of a superstar molecule. The viability of cells on the PDA coating exhibited time dependence, and the decreased cell viability during the normal observation time was found to come from the decrease of cell number instead of the decrease of average viability per cell. The PDA coating led to less cell global migration yet more local motility of cells. Based on the concept of “background adhesion” of cells on a surface without significant motifs of specific cell adhesion, we supposed that cells adhered to the PDA coating better, which influenced mobility and eventually proliferation. Hence, the cell behaviors on the PDA coating are reasonable, albeit a bit complicated.