Uniaxial and Mixed Orientations of Poly(ethylene oxide) in Nanoporous Alumina Studied by X-ray Pole Figure Analysis

The orientation of polymers under confinement is a basic, yet not fully understood phenomenon. In this work, the texture of poly(ethylene oxide) (PEO) infiltrated in nanoporous anodic alumina oxide (AAO) templates was investigated by X-ray pole figures. The influence of geometry and crystallization conditions, such as pore diameter, aspect ratio, and cooling rates, was systematically examined. All the samples exhibited a single, volume-dependent crystallization temperature (Tc) at temperatures much lower than that exhibited by bulk PEO, indicating “clean” microdomains without detectable heterogeneous nucleation. An “orientation diagram” was established to account for the experimental observations. Under very high cooling rates (quenching), crystallization of PEO within AAO was nucleation-controlled, adopting a random distribution of crystallites. Under low cooling rates, growth kinetics played a decisive role on the crystal orientation. A relatively faster cooling rate (10 °C/min) and/or smaller pores lead to the * ║ pore axis (n⃗) mode (uniaxial orientation). When the cooling rate was lower (1 °C/min), and/or the pores were larger, a mixed orientation, with a coexistence of * ║ n⃗ and * ║ n⃗ , was observed. The results favor the kinetic model where the fastest growth direction tends to align parallel to the pore axis.This work is supported by the National Natural Science Foundation of China (NSFC, 21873109, 51820105005, 21274156). G. L. is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2015026). G. L., D. W., and A. J. M. also acknowledge European funding by the RISE BIODEST project (H2020-MSCA-RISE-2017-778092). The authors thank Dr. Zhongkai Yang for assistance with pole figure measurement

Altered Spontaneous Brain Activity in Cortical and Subcortical Regions in Parkinson’s Disease

Purpose. The present study aimed to explore the changes of amplitude of low-frequency fluctuations (ALFF) at rest in patients with Parkinson’s disease (PD). Methods. Twenty-four PD patients and 22 healthy age-matched controls participated in the study. ALFF was measured on the whole brain of all participants. A two-sample t-test was then performed to detect the group differences with age, gender, education level, head motion, and gray matter volume as covariates. Results. It was showed that PD patients had significantly decreased ALFF in the left thalamus/caudate and right insula/inferior prefrontal gyrus, whereas they had increased ALFF in the right medial prefrontal cortex (BA 8/6) and dorsolateral prefrontal cortex (BA 9/10). Conclusions. Our results indicated that significant alterations of ALFF in the subcortical regions and prefrontal cortex have been detected in PD patients, independent of age, gender, education, head motion, and structural atrophy. The current findings further provide insights into the biological mechanism of the disease

The influence of passivation and photovoltaic properties of α-Si:H coverage on silicon nanowire array solar cells

Silicon nanowire (SiNW) arrays for radial p-n junction solar cells offer potential advantages of light trapping effects and quick charge collection. Nevertheless, lower open circuit voltages (V(oc)) lead to lower energy conversion efficiencies. In such cases, the performance of the solar cells depends critically on the quality of the SiNW interfaces. In this study, SiNW core-shell solar cells have been fabricated by growing crystalline silicon (c-Si) nanowires via the metal-assisted chemical etching method and by depositing hydrogenated amorphous silicon (α-Si:H) via the plasma-enhanced chemical vapor deposition (PECVD) method. The influence of deposition parameters on the coverage and, consequently, the passivation and photovoltaic properties of α-Si:H layers on SiNW solar cells have been analyzed

Precuneus Dysfunction in Parkinson’s Disease With Mild Cognitive Impairment

Background: Mild cognitive impairment (MCI) frequently occurs in Parkinson’s disease (PD). Neurovascular changes interact with neurodegenerative processes in PD. However, the deficits of cerebral blood flow (CBF) perfusion and the associated functional connectivity (FC) in PD patients with MCI (PD-MCI) remain unclear.Purpose: This study aimed to explore the specific neurovascular perfusion alterations in PD-MCI compared to PD with normal cognition (PD-NC) and healthy controls (HCs), and to further examine the resultant whole brain FC changes in the abnormal perfusion regions.Methods: Relative CBF (rCBF) was calculated using arterial spin labeling (ASL) in 54 patients with PD (27 patients with PD-NC and 27 patients with PD-MCI) and 25 HCs matched for age and gender ratio, who also underwent the structural MRI, resting-state functional MRI (rs-fMRI) and neuropsychological examinations. The gray matter (GM) changes in PD patients were analyzed using voxel-based morphometry (VBM). The alterations in rCBF perfusion and FC among groups were then analyzed respectively. Additionally, correlations between these alterations and neuropsychological performances were further examined.Results: Compared to HC, left caudate atrophy was detected in patients with PD. In comparison to both PD-NC and HC, patients with PD-MCI specifically exhibited hypoperfusion in the parietal memory network (PMN) in the precuneus (PCu) and decreased PCu-FC in the right striatum. Moreover, PCu perfusion and PCu-FC strengths in the right striatum were positively associated with memory performance in PD-MCI.Conclusions: These findings suggest that the posterior PMN dysfunction underlies memory deficits in PD-MCI

Effectiveness and safety of Compound Danshen injection as treatment for pregnancy-induced hypertension: A metaanalysis

Purpose: To systematically evaluate the effectiveness and safety of Compound Danshen injection in patients with pregnancy-induced hypertension (PIH).Methods: PubMed, Embase, Cochrane Library, Chinese biomedical literature database (CBM), VIP (xiAn), China National Knowledge Infrastructure (CNKI) and Wan Fang databases were searched up to March 20, 2018, for all randomized controlled trials (RCTs) on the use of Compound Danshen injection in patients with PIH. Data were extracted from included studies after assessing the quality of literature. Revman 5.3 software was used for statistical analysis．Results: A total of 18 RCTs involving 1735 patients were included. The results of meta-analysis indicated that the study group was superior to the control group in clinical effectiveness (RR = 1.15, 95 % CI: 1.02 - 1.30); intrauterine fetal distress (RR = 0.26, 95 % CI: 0.09 - 0.70); cesarean section (RR = 0.72, 95 % CI: 0.58 - 0.90), and neonatal asphyxia (RR = 0.23, 95 % CI: 0.11 - 0.48). There were no statistical differences in fetal heart rate abnormalities (RR = 0.58, 95 %, CI: 0.33 - 1.02, p > 0.05) and postpartum hemorrhage (RR = 0.86, 95 % CI: 0.53 - 1.42) between the two groups.Conclusion: Treatment of PIH with Compound Danshen injection (alone or in combination) is superior to the use of conventional western medical treatment in safety and effectiveness. However, higher quality clinical studies are needed to confirm these results because most trials included in this study were of low quality.Keywords: Pregnancy-induced hypertension (PIH), Compound Danshen injection, Meta-analysi