Patterning of Polymer-Functionalized Nanoparticles with Varied Surface Mobilities of Polymers.

The polymers can be either dynamically tethered to or permanently grafted to the nanoparticle to produce polymer-functionalized nanoparticles. The surface mobility of polymer ligands with one end anchored to the nanoparticle can affect the surface pattern, but the effect remains unclear. Here, we addressed the influence of lateral polymer mobility on surface patterns by performing self-consistent field theory calculations on a modeled polymer-functionalized nanoparticle consisting of immobile and mobile brushes. The results show that except for the radius of nanoparticles and grafting density, the fraction of mobile brushes substantially influences the surface patterning of polymer-functionalized nanoparticles, including striped patterns and patchy patterns with various patches. The number of patches on a nanoparticle increases as the fraction of mobile brushes decreases, favored by the entropy of immobile brushes. Critically, we found that broken symmetry usually occurs in patchy nanoparticles, associated with the balance of enthalpic and entropic effects. The present work provides a fundamental understanding of the dependence of surface patterning on lateral polymer mobility. The work could also guide the preparation of diversified nanopatterns, especially for the asymmetric patchy nanoparticles, enabling the fundamental investigation of the interaction between polymer-functionalized nanoparticles.

Clinical Practice Guidelines for the Management of Behavioral and Psychological Symptoms of Dementia: A Systematic Review With AGREE II.

Background: High-quality clinical practice guidelines (CPGs) are important for the effective treatment of behavioral and psychological symptoms of dementia (BPSD). However, recommendations provided by different quality guidelines may lead to varied clinical practice outcomes. Objective: To assess the quality of available CPGs for the management of BPSD and summarize the best recommendations for treating BPSD. Methods: This was a systematic review of CPGs for the management of BPSD with data obtained from electronic databases and evaluated using the Appraisal of Guidelines for Research and Evaluation II instrument, consisting of six domains: "Scope and purpose", "Stakeholder involvement", "Rigor of development", "Clarity of presentation", "Applicability", and "Editorial independence". The criteria for high-quality guidelines were set as: the score of high-quality guidelines in the "Rigor of development" domain should be ≥60% and as well as a score of >60% in at least three other domains. High-quality guidelines were selected for recommendation extraction, and the final recommendations were formed in combination with the latest meta-analysis and randomized clinical-trial results. Results: In term of median scores in each domain for the six included CPGs, "Scope and purpose" (87.5%) scored better than all others, whereas "Applicability" (46.5%) was the domain with the lowest score. Four CPGs (2015 APA, 2018 NICE, 2018 CANADA, 2020 EAN) met the criteria of high-quality guidelines and were used to extract recommendations. From these four CPGs, nine specific recommendations related to the management of BPSD were summarized, of which seven were related to pharmacological treatment and two to non-pharmacological treatment. These recommendations covered the applicability of antipsychotic drugs, medication recommendations, withdrawal times, and several suitable non-pharmacological therapies. Conclusion: The quality of CPGs for the management of BPSD requires improvement, especially for the "Applicability" domain. For psychotic-like symptoms in dementia, the use of antipsychotics should be based on the individual's risk-benefit ratio, and the use of atypical antipsychotics seems to be a better choice. Non-pharmacological treatments may be suitable for emotional symptoms and sleep disorders. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020209204.

Generation and characterization of a human induced pluripotent stem cell line (XWHNi001-A) derived from an Alzheimer's disease patient with mutation in the APP gene.

Mutations in the APP gene are popularly known as the second cause trigger the familial Alzheimer's disease (AD). We generated a human induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells isolated from an AD patient using non-integrative Sendai virus. The iPSC line highly expresses pluripotency markers, has the capacity to differentiate into the normal teratoma tissue, retains the APP mutation, and displays the normal karyotype. The iPSC line will provide a useful resource to study the pathogenesis and drugs screening of AD.

A Comparative Study of Structural and Metabolic Brain Networks in Patients With Mild Cognitive Impairment.

Background: Changes in the metabolic and structural brain networks in mild cognitive impairment (MCI) have been widely researched. However, few studies have compared the differences in the topological properties of the metabolic and structural brain networks in patients with MCI. Methods: We analyzedmagnetic resonance imaging (MRI) and fluoro-deoxyglucose positron emission tomography (FDG-PET) data of 137 patients with MCI and 80 healthy controls (HCs). The HC group data comes from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The permutation test was used to compare the network parameters (characteristic path length, clustering coefficient, local efficiency, and global efficiency) between the two groups. Partial Pearson's correlation analysis was used to calculate the correlations of the changes in gray matter volume and glucose intake in the key brain regions in MCI with the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-cog) sub-item scores. Results: Significant changes in the brain network parameters (longer characteristic path length, larger clustering coefficient, and lower local efficiency and global efficiency) were greater in the structural network than in the metabolic network (longer characteristic path length) in MCI patients than in HCs. We obtained the key brain regions (left globus pallidus, right calcarine fissure and its surrounding cortex, left lingual gyrus) by scanning the hubs. The volume of gray matter atrophy in the left globus pallidus was significantly positively correlated with comprehension of spoken language (p = 0.024) and word-finding difficulty in spontaneous speech item scores (p = 0.007) in the ADAS-cog. Glucose intake in the three key brain regions was significantly negatively correlated with remembering test instructions items in ADAS-cog (p = 0.020, p = 0.014, and p = 0.008, respectively). Conclusion: Structural brain networks showed more changes than metabolic brain networks in patients with MCI. Some brain regions with significant changes in betweenness centrality in both structural and metabolic networks were associated with MCI.

Self-assembly and stimuli-responsive behaviours of side-chain liquid crystalline copolymers: a dissipative particle dynamics simulation approach.

We conducted a dissipative particle dynamics simulation to explore the self-assembly behaviours of side-chain liquid crystalline copolymers in solvents poor for comb blocks. Our results show that the copolymers are able to self-assemble into various aggregates such as micelles and vesicles, and especially into deformed structures such as rectangle cylinders. The morphology of the aggregates depends on the concentration of copolymers and a series of structural parameters such as the length of the coil blocks. Three kinds of morphology diagrams are mapped out to gain insight into the effect of these parameters on the self-assembly behaviours. Moreover, the aggregate structures such as the spatial arrangement of the rigid side chain are analysed, and it was found that the interfaces of the aggregates are greatly influenced by the packing of the side chains. We also investigated the influence of the rod-to-coil conformation transition of side chains on the self-assembly, motivated by stimuli-responsive polymer systems. A transformation from a disk-like structure to a vesicle was observed as the rod-to-coil conformation transition occurs. A comparison between the available experimental observations and the simulation results is made, and agreement is achieved.

Self-Assembly of Rod-Coil Block Copolymers on Carbon Nanotubes: A Route toward Diverse Surface Nanostructures.

In this work, it is reported that poly(γ-benzyl-l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) rod-coil block copolymers (BCPs) can disperse carbon nanotubes (CNTs) in solution and form various surface nanostructures on the CNTs via solution self-assembly. In an organic solvent that dissolves the BCPs, the PBLG rod blocks adsorb on CNT surfaces, and the BCPs form conformal coatings. Then, by the introduction of water, a selective solvent for PEG blocks, the BCPs in the coatings further self-assemble into diverse surface nanostructures, such as helices (left-handed or right-handed), gyros, spheres, and rings. The morphology of the surface nanostructure can be tailored by initial organic solvent composition, preparation temperature, feeding ratio of BCPs to CNTs, degree of polymerization of PBLG blocks, and diameter of the CNTs.