Enantiomorphic Site-Assisted Chain End Control Stereospecific Alternating Copolymerization of Chiral Cyclic Diesters.

Stereospecific alternating copolymerization of different chiral cyclic esters is one feasible approach to enrich the structural diversity of copolyesters and tailor their properties. However, dramatically different reactivities of different cyclic esters let a perfectly stereospecific alternating polymerization of these cyclic esters be a challenge, thus the catalyst is required to balance their reactivities. Herein, a remarkable enantiomorphic site effect on chain end control was discovered and successfully utilized to balance the reactivities of highly reactive S, S-lactide (S, S-LA) and low reactive R, R-ethylglycolide (R, R-EG)/R, R-propylglycolide (R, R-PG) during their heterospecific alternating copolymerization.

Neuronal-enriched small extracellular vesicles trigger a PD-L1-mediated broad suppression of T cells in Parkinson's disease.

Many clinical studies indicate a significant decrease of peripheral T cells in Parkinson's disease (PD). There is currently no mechanistic explanation for this important observation. Here, we found that small extracellular vesicles (sEVs) derived from and PD models suppressed IL-4 and INF-γ production from both purified CD4 and CD8 T cells and inhibited their activation and proliferation.

Volume Stability and Frost Resistance of High-Ductility Magnesium Phosphate Cementitious Concrete.

To address the issue of pavement cracking due to brittle concrete in road and bridge engineering, this study explores the use of high-ductility magnesium phosphate cementitious concrete (HD-MPCC) for rapid repairs. The deformation and frost properties of HD-MPCC are analyzed to assess its suitability for this application. Deformation properties were tested for HD-MPCC specimens cured in both air and water.

Tetrabutylammonium Halides as Selectively Bifunctional Catalysts Enabling the Syntheses of Recyclable High Molecular Weight Salicylic Acid-Based Copolyesters.

To synthesize high molecular weight poly(phenolic ester) via a living ring-opening polymerization (ROP) of cyclic phenolic ester monomers remains a critical challenge due to serious transesterification and back-biting reactions. Both phenolic ester bonds in monomer and polymer chains are highly active, and it is difficult so far to distinguish them. In this work, an unprecedented selectively bifunctional catalytic system of tetra-n-butylammonium chloride (TBACl) was discovered to mediate the syntheses of high molecular weight salicylic acid-based copolyesters via a living ROP of salicylate cyclic esters (for poly(salicylic methyl glycolide) (PSMG), M =361.

MAPT rs17649553 T allele is associated with better verbal memory and higher small-world properties in Parkinson's disease.

Currently, over 90 genetic loci have been found to be associated with Parkinson's disease (PD) in genome-wide association studies, nevertheless, the effects of these genetic variants on the clinical features and brain structure of PD patients are largely unknown. This study investigated the effects of microtubule-associated protein tau (MAPT) rs17649553 (C>T), a genetic variant associated with reduced PD risk, on the clinical manifestations and brain networks of PD patients. We found MAPT rs17649553 T allele was associated with better verbal memory in PD patients.

Effect of Ambient Temperature on the Mechanical Properties of High Ductility Concrete.

This study analyzes the mechanical properties of high ductility concrete (HDC) under different ambient temperatures to provide a parameter basis for the design of HDC bridge deck link slabs. Five temperatures (-30, 0, 20, 40, and 60 °C) were designed to investigate the compressive, tensile, and flexural properties of HDC after temperature treatment and analyze the pore structure. The results show that, compared with the HDC performance at room temperature (20 °C), the compressive strength, ultimate tensile strength, and flexural strength decreased after treatment at low temperatures (-30 and 0 °C), while the strength increased after treatment at high temperatures (40 and 60 °C).

Age and sex differentially shape brain networks in Parkinson's disease.

Aims: Age and sex are important individual factors modifying the clinical symptoms of patients with Parkinson's disease (PD). Our goal is to evaluate the effects of age and sex on brain networks and clinical manifestations of PD patients.

Methods: Parkinson's disease participants (n = 198) receiving functional magnetic resonance imaging from Parkinson's Progression Markers Initiative database were investigated.

Photoinduced Promiscuity of Cyclohexanone Monooxygenase for the Enantioselective Synthesis of α-Fluoroketones.

The development of mild, efficient, and enantioselective methods for preparing chiral fluorinated compounds has been a long-standing challenge. Herein, we report a promiscuous cyclohexanone monooxygenase (CHMO) for the photoinduced synthesis of chiral α-fluoroketones via enantioselective reductive dehalogenation of α,α-halofluoroketones. Wild-type CHMO from Acinetobacter sp.

Impaired Ocular Tracking and Cortical Atrophy in Idiopathic Rapid Eye Movement Sleep Behavior Disorder.

Background: Idiopathic rapid eye movement sleep behavior disorder (iRBD) is a prodromal stage of synucleinopathies. Patients with synucleinopathies frequently display eye movement abnormalities. However, whether patients with iRBD have eye movement abnormalities remains unknown.

Increased free water in the substantia nigra in idiopathic REM sleep behaviour disorder.

Imaging markers sensitive to neurodegeneration in the substantia nigra are critically needed for future disease-modifying trials. Previous studies have demonstrated the utility of posterior substantia nigra free water as a marker of progression in Parkinson's disease. In this study, we tested the hypothesis that free water is elevated in the posterior substantia nigra of idiopathic REM sleep behaviour disorder, which is considered a prodromal stage of synucleinopathy.

Isotactic-Alternating, Heterotactic-Alternating, and ABAA-Type Sequence-Controlled Copolyester Syntheses via Highly Stereoselective and Regioselective Ring-Opening Polymerization of Cyclic Diesters.

Synthesizing different types of sequence-controlled copolyesters can enrich the diversity of copolyesters and modify their properties more precisely, but it is still a challenge to synthesize a complicated sequence-controlled copolyester using different hydroxy acids in a living polymerization manner. In this work, a highly regioselective and stereoselective catalytic system was developed to synthesize biorenewable and biodegradable copolyesters of mandelic acid and lactic acid with isotactic-alternating, heterotactic-alternating, and ABAA-type precise and complicated sequences. Because of the regular incorporation of mandelic acid into polylactide, these sequence-controlled copolymers of mandelic acid and lactic acid show higher glass-transition temperatures than polylactide and a random copolymer.

Dendrobium officinale flos increases neurotrophic factor expression in the hippocampus of chronic unpredictable mild stress-exposed mice and in astrocyte primary culture and potentiates NGF-induced neuronal differentiation in PC12 cells.

Dendrobium officinale flos (DOF) is the flower of Dendrobium officinale Kimura et Migo, which is usually regarded as a by-product of Dendrobii Offcinalis Caulis. Based on its use as an alternative medicine, we evaluated the antidepressant-like effect of DOF extracts on chronic, unpredictable, mild stress-induced, depression-like behaviour in mice and tested the effects of DOF on the regulation of neurotrophic factors in mouse astrocyte primary cultures and PC12 cell lines. Oral treatment with DOF ethanol extract (DOF-E) could alleviate depression-like behaviours in stress-exposed mice, as evidenced by increased sucrose consumption and decreased immobile time in a forced swim test.

Dynamic functional connectivity impairments in idiopathic rapid eye movement sleep behavior disorder.

Introduction: Previous functional magnetic resonance imaging (fMRI) studies typically analyzed static functional connectivity (sFC) to reveal the pathophysiology of iRBD and overlooked the dynamic nature of brain activity. Thus, we aimed to explore whether iRBD showed abnormalities of brain network dynamics using the dynamic functional connectivity (dFC) approach.

Methods: Resting-state fMRI data from 33 iRBD patients and 38 matched healthy controls were analyzed using an independent component analysis, sliding window correlation and k-means clustering.

Abnormal intrinsic brain activity of the putamen is correlated with dopamine deficiency in idiopathic rapid eye movement sleep behavior disorder.

Objectives: To investigate the changes in spontaneous neuronal activity of the striatum in idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) patients using regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) analysis. Furthermore, we tested the association between abnormal spontaneous brain activity and dopamine deficit in patients with iRBD.

Methods: Fifteen iRBD patients and 15 matched healthy controls received resting state magnetic resonance imaging (MRI) and neuropsychological assessments.

Gait Characteristics and Brain Activity in Parkinson's Disease with Concomitant Postural Abnormalities.

To explore the underlying pathogenic mechanism of Parkinson's disease (PD) with concomitant postural abnormalities (PDPA) through the relationship between its gait and brain function characteristics. PD patients from the neurology outpatient clinic at Ruijin Hospital were recruited and grouped according to whether postural abnormalities (including camptocormia and Pisa syndrome) were present. PD-related scale assessments, three-dimensional gait tests and brain resting-state functional magnetic imaging were performed and analyzed.

Altered structure and functional connectivity of the central autonomic network in idiopathic rapid eye movement sleep behaviour disorder.

Evidence suggests peripheral autonomic structures may contribute to autonomic dysfunction in idiopathic rapid eye movement sleep behaviour disorder (iRBD). However, whether the central autonomic network (CAN) is affected in iRBD remains unclear. Magnetic resonance imaging data were acquired from 65 participants (32 patients with iRBD and 33 matched healthy controls).

CXCL12 is involved in α-synuclein-triggered neuroinflammation of Parkinson's disease.

Background: The mechanisms underlying the pathogenesis and progression of Parkinson's disease (PD) remain elusive, but recent opinions and perspectives have focused on whether the inflammation process induced by microglia contributes to α-synuclein-mediated toxicity. Migration of microglia to the substantia nigra (SN) could precede neurodegeneration in A53T mice. We hypothesized that CXCL12 could be a mediator in the α-synuclein-induced migration of microglia.

Autonomic dysfunction in Parkinson's disease: Implications for pathophysiology, diagnosis, and treatment.

Parkinson's disease (PD) is a neurodegenerative disease with a 200 year-long research history. Our understanding about its clinical phenotype and pathogenesis remains limited, although dopaminergic replacement therapy has significantly improved patient outcomes. Autonomic dysfunction is an essential category of non-motor phenotypes that has recently become a cutting edge field that directs frontier research in PD.

The role of T cells in the pathogenesis of Parkinson's disease.

Recent evidence has shown that neuroinflammation plays a key role in the pathogenesis of Parkinson's disease (PD). However, different components of the brain's immune system may exert diverse effects on neuroinflammatory events in PD. The adaptive immune response, especially the T cell response, can trigger type 1 pro-inflammatory activities and suppress type 2 anti-inflammatory activities, eventually resulting in deregulated neuroinflammation and subsequent dopaminergic neurodegeneration.

Thiamine diphosphate reduction strongly correlates with brain glucose hypometabolism in Alzheimer's disease, whereas amyloid deposition does not.

Background: The underlying mechanism of brain glucose hypometabolism, an invariant neurodegenerative feature that tightly correlates with cognitive impairment and disease progression of Alzheimer's disease (AD), remains elusive.

Methods: Positron emission tomography with 2-[F]fluoro-2-deoxy-D-glucose (FDG-PET) was used to evaluate brain glucose metabolism, presented as the rate of 2-[F]fluoro-2-deoxy-D-glucose standardized uptake value ratio (FDG SUVR) in patients with AD or control subjects and in mice with or without thiamine deficiency induced by a thiamine-deprived diet. Brain amyloid-β (Aβ) deposition in patients with clinically diagnosed AD was quantified by performing assays using C-Pittsburgh compound B PET.

Diagnostic value of blood thiamine metabolites in Alzheimer's disease examined by C-PiB PET scanning.

Aim: We evaluated the diagnostic value of blood thiamine metabolites for Alzheimer's disease (AD) by using positron emission tomography with C-Pittsburgh compound B (C-PiB PET) scanning.

Methods: Thirty-eight clinically diagnosed AD patients were voluntarily recruited. Blood thiamine metabolites were measured by high-performance liquid chromatography.

Long-Term Cognitive Improvement After Benfotiamine Administration in Patients with Alzheimer's Disease.

To date, we still lack disease-modifying therapies for Alzheimer's disease (AD). Here, we report that long-term administration of benfotiamine improved the cognitive ability of patients with AD. Five patients with mild to moderate AD received oral benfotiamine (300 mg daily) over 18 months.

Measurement of Blood Thiamine Metabolites for Alzheimer's Disease Diagnosis.

Background: Brain glucose hypometabolism is an invariant feature and has significant diagnostic value for Alzheimer's disease. Thiamine diphosphate (TDP) is a critical coenzyme for glucose metabolism and significantly reduced in brain and blood samples of patients with Alzheimer's disease (AD).

Aims: To explore the diagnostic value of the measurement of blood thiamine metabolites for AD.

Inhibitory effects of cytochrome P450 enzymes CYP1A2, CYP2A6, CYP2E1 and CYP3A4 by extracts and alkaloids of Gelsemium elegans roots.

Ethnopharmacological Relevance: Gelsemium elegans (GE), widely distributed in East Asia, South East Asia and Northern America, is a kind of well-known toxic plant throughout the world. Yet it has been used as a Chinese folk medicine for treatment of malignant tumors, pain, rheumatic arthritis, psoriasis and immune function.

Aim Of The Study: The present study was to investigate the potential inhibitory effects of G.