Yingxin He

Washington University in St. Louis | WUSTL , Wash U · Department of Neurology

Cerebrospinal fluid (CSF) amyloid-β peptide (Aβ)42/Aβ40 and the concentration of tau phosphorylated at site 181 (p-tau181) are well-established biomarkers of Alzheimer’s disease (AD). The present study used mass spectrometry to measure concentrations of nine phosphorylated and five nonphosphorylated tau species and phosphorylation occupancies (perc...

Introduction: Sleep deprivation increases cerebrospinal fluid (CSF) amyloid beta (Aβ) and tau levels; however, sleep's effect on Aβ and tau in plasma is unknown. Methods: In a cross-over design, CSF Aβ and tau concentrations were measured in five cognitively normal individuals who had blood and CSF collected every 2 hours for 36 hours during sle...

Hyperphosphorylated tau isoforms (p‐tau) in cerebrospinal fluid (CSF) and plasma represent promising measures to monitor Alzheimer disease (AD) pathological changes. Brain amyloid deposition precedes tau aggregation and associated clinical decline by two decades. Several CSF and plasma p‐tau isoforms have been described as potential surrogates for...

Despite recent advances in fluid biomarker research in Alzheimer’s disease (AD), there are no fluid biomarkers or imaging tracers with utility for diagnosis and/or theragnosis available for other tauopathies. Using immunoprecipitation and mass spectrometry, we show that 4 repeat (4R) isoform-specific tau species from microtubule-binding region (MTB...

CSF Aβ42/Aβ40 and tau phosphorylated at site 181 (p-tau181) are well-established biomarkers of Alzheimer disease (AD). This study used mass spectrometry to measure concentrations of 9 phosphorylated and 5 non-phosphorylated species, and phosphorylation occupancies (phosphorylated/non-phosphorylated [%]) at 10 sites. In 750 individuals with a median...

Plasma phospho-tau (p-tau) species have emerged as the most promising blood-based biomarkers of Alzheimer's disease. Here, we performed a head-to-head comparison of p-tau181, p-tau217 and p-tau231 measured using 10 assays to detect abnormal brain amyloid-β status and predict future progression to Alzheimer's dementia. The study included 135 patient...

Neurofilament light is a well-established marker of both acute and chronic neuronal damage and is increased in multiple neurodegenerative diseases. However, the protein is not well characterized in brain tissue or body fluids, and it is unknown what neurofilament light species are detected by commercial assays and whether additional species exist....

Catalytically active asymmetric membranes were developed by crosslinking a polydimethylsiloxane (PDMS) thin layer onto a porous polyamide‐imide hollow fiber (PAIHF) support, followed by grafting of aminosilane with hydroxyl derived-PDMS/PAIHF, and finally palladium nanoparticles (PdNPs) immobilization using salicylic aldehyde. Aminosilane and salic...

The use of multifunctional organocatalysts and continuous flow platform are commonplace in modern chemical transformation. Herein, we describe a method for immobilization of trifunctional organocatalysts on porous composite hollow fiber and demonstrate their application as heterogeneous catalyst and continuous-flow microfluidic reactor for chemical...

In this study, we demonstrate the concept of tandem reaction for glucose and fructose to 5-hydroxymethylfurfural (HMF) in an aminosilane-grafted SiO2-ZrO2 polyamide-imide hollow fiber that acts as a bifunctional heterogeneous catalyst and microfluidic reactor. The bifunctional catalysts were formed by embedding SiO2 and ZrO2 nanoparticles into poly...

The highly hydrophilic and solvent-stable porous polyamide-imide (PAI) hollow fibers were created by crosslinking of bare PAI hollow fibers with 3-aminopropyl trimethoxy silane (APS). The APS-grafted PAI hollow fibers were then functionalized with salicylic aldehyde for binding catalytically active Pd(II) ions through covalent post-modification met...

A series of transition metal oxides (e.g., Ni, Cu, Zn, and Zr) were supported on H-beta with loading of 5-20 wt% via wet impregnation. These catalysts were evaluated in the hydrogenolysis of glycerol under aqueous conditions at different reaction temperatures (150-250 °C), times (5-15 h) and H2 pressures (300-1200 psi). The results from characteriz...

In this work, the development of novel binary and ternary oxide/Torlon hollow fiber composites comprising zirconia, titania, and silica as amine supports was demonstrated. The resulting binary (Zr-Si/PAI-HF, Ti-Si/PAI-HF) and ternary (Zr-Ti-Si/PAI-HF) composites were then functionalized with monoamine-, diamine-, and triamine-substituted trialkoxys...

Propylene is an important constituent of many products that we rely upon in our daily life. This essential raw material is currently produced from fossil-derived feedstocks such as oil and natural gas. However, conversion of bioethanol to propylene represents an interesting opportunity for the utilization of renewable feedstocks such as bioethanol...

Propylene is an important constituent of many products that we rely upon in our daily life. This essential raw material is currently produced from fossil-derived feedstocks such as oil and natural gas. However, conversion of bioethanol to propylene represents an interesting opportunity for the utilization of renewable feedstocks such as bioethanol...