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1.
ACS Sustain Chem Eng ; 12(15): 6035-6036, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38638548

ABSTRACT

[This corrects the article DOI: 10.1021/acssuschemeng.3c00141.].

2.
Nature ; 628(8006): 154-161, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38480892

ABSTRACT

Several genetic risk factors for Alzheimer's disease implicate genes involved in lipid metabolism and many of these lipid genes are highly expressed in glial cells1. However, the relationship between lipid metabolism in glia and Alzheimer's disease pathology remains poorly understood. Through single-nucleus RNA sequencing of brain tissue in Alzheimer's disease, we have identified a microglial state defined by the expression of the lipid droplet-associated enzyme ACSL1 with ACSL1-positive microglia being most abundant in patients with Alzheimer's disease having the APOE4/4 genotype. In human induced pluripotent stem cell-derived microglia, fibrillar Aß induces ACSL1 expression, triglyceride synthesis and lipid droplet accumulation in an APOE-dependent manner. Additionally, conditioned media from lipid droplet-containing microglia lead to Tau phosphorylation and neurotoxicity in an APOE-dependent manner. Our findings suggest a link between genetic risk factors for Alzheimer's disease with microglial lipid droplet accumulation and neurotoxic microglia-derived factors, potentially providing therapeutic strategies for Alzheimer's disease.


Subject(s)
Alzheimer Disease , Apolipoprotein E4 , Lipid Droplets , Microglia , Animals , Female , Humans , Male , Mice , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Apolipoprotein E4/genetics , Apolipoprotein E4/metabolism , Induced Pluripotent Stem Cells/cytology , Lipid Droplets/metabolism , Lipid Droplets/pathology , Microglia/cytology , Microglia/metabolism , Microglia/pathology , Triglycerides , tau Proteins , Culture Media, Conditioned , Phosphorylation , Genetic Predisposition to Disease
3.
Chemphyschem ; 25(9): e202300810, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38349198

ABSTRACT

A new class of fluorine-free ionic liquids (ILs) and electrolytes based on aliphatic flexible oligoether anions, 2-(2-methoxyethoxy)acetate (MEA) and 2-[2-(2-methoxyethoxy)ethoxy]acetate (MEEA), coupled with pyrrolidinium and imidazolium cations is introduced. For the ILs with MEEA anions, Li+ conducting electrolytes are created by doping the ILs with 30 mol % of LiMEEA. The structural flexibility of the oligoether functionality in the anion results in glass transition temperatures (Tg) as low as -60 °C for the neat ILs and the electrolytes. The imidazolium-based ILs and electrolytes reveal better thermal stabilities but higher Tg and lower electrochemical stabilities than the corresponding pyrrolidinium-based analogues. All neat ILs show comparable transport properties for the cations and these decrease by the addition of lithium salt - the pyrrolidinium-based electrolyte being affected the most.

4.
Front Cell Infect Microbiol ; 13: 1250339, 2023.
Article in English | MEDLINE | ID: mdl-37965262

ABSTRACT

Pseudomonas aeruginosa is a major human pathogen, particularly effective at colonizing the airways of patients with cystic fibrosis. Bacteriophages are highly abundant at infection sites, but their impact on mammalian immunity remains unclear. We previously showed that Pf4, a temperate filamentous bacteriophage produced by P. aeruginosa, modifies the innate immune response to P. aeruginosa infections via TLR3 signaling, but the underlying mechanisms remained unclear. Notably, Pf4 is a single-stranded DNA and lysogenic phage, and its production does not typically result in lysis of its bacterial host. We identified previously that internalization of Pf4 by human or murine immune cells triggers maladaptive viral pattern recognition receptors and resulted in bacterial persistence based on the presence of phage RNA. We report now that Pf4 phage dampens inflammatory responses to bacterial endotoxin and that this is mediated in part via bacterial vesicles attached to phage particles. Outer membrane vesicles (OMVs) are produced by Gram-negative bacteria and play a key role in host pathogen interaction. Recently, evidence has emerged that OMVs differentially package small RNAs. In this study, we show that Pf4 are decorated with OMVs that remain affixed to Pf4 despite of purification steps. These phages are endocytosed by human cells and delivered to endosomal vesicles. We demonstrate that short RNAs within the OMVs form hairpin structures that trigger TLR3-dependent type I interferon production and antagonize production of antibacterial cytokines and chemokines. In particular, Pf4 phages inhibit CXCL5, preventing efficient neutrophil chemotaxis in response to endotoxin. Moreover, blocking IFNAR or TLR3 signaling abrogates the effect of Pf4 bound to OMVs on macrophage activation. In a murine acute pneumonia model, mice treated with Pf4 associated with OMVs show significantly less neutrophil infiltration in BAL fluid than mice treated with purified Pf4. These changes in macrophage phenotype are functionally relevant: conditioned media from cells exposed to Pf4 decorated with OMVs are significantly less effective at inducing neutrophil migration in vitro and in vivo. These results suggest that Pf4 phages alter innate immunity to bacterial endotoxin and OMVs, potentially dampening inflammation at sites of bacterial colonization or infection.


Subject(s)
Bacteriophages , Pseudomonas Infections , Humans , Animals , Mice , Neutrophils/metabolism , Bacterial Outer Membrane/metabolism , Toll-Like Receptor 3 , Pseudomonas Infections/microbiology , Endotoxins , Mammals
5.
bioRxiv ; 2023 Jul 25.
Article in English | MEDLINE | ID: mdl-37546938

ABSTRACT

Several genetic risk factors for Alzheimer's Disease (AD) implicate genes involved in lipid metabolism and many of these lipid genes are highly expressed in glial cells. However, the relationship between lipid metabolism in glia and AD pathology remains poorly understood. Through single-nucleus RNA-sequencing of AD brain tissue, we have identified a microglial state defined by the expression of the lipid droplet (LD) associated enzyme ACSL1 with ACSL1-positive microglia most abundant in AD patients with the APOE4/4 genotype. In human iPSC-derived microglia (iMG) fibrillar Aß (fAß) induces ACSL1 expression, triglyceride synthesis, and LD accumulation in an APOE-dependent manner. Additionally, conditioned media from LD-containing microglia leads to Tau phosphorylation and neurotoxicity in an APOE-dependent manner. Our findings suggest a link between genetic risk factors for AD with microglial LD accumulation and neurotoxic microglial-derived factors, potentially providing novel therapeutic strategies for AD.

6.
Phys Chem Chem Phys ; 25(29): 19815-19823, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37449961

ABSTRACT

Ion transport measures and details as well as physico-chemical and electrochemical properties are presented for a small set of structurally flexible pyrrolidinium (Pyrr) and morpholinium (Morph) cation-based ionic liquids (ILs), all with oligoether phosphate-based anions. All have high thermal stabilities, low glass transition temperatures, and wide electrochemical stability windows, but rather moderate ionic conductivities, where both the anions and the cations of the Pyrr-based ILs diffuse faster than those of the Morph-based ILs. Overall, the Pyrr-based ILs show significantly more promise as high-temperature supercapacitor electrolytes, rendering a specific capacitance of 164 F g-1 at 1 mV s-1, a power density of 609 W kg-1 and a specific energy density of 27 W h kg-1 at 90 °C in a symmetric graphite supercapacitor.

7.
J Phys Chem C Nanomater Interfaces ; 127(20): 9823-9832, 2023 May 25.
Article in English | MEDLINE | ID: mdl-37255926

ABSTRACT

Highly concentrated aqueous binary solutions of acetate salts are promising systems for different electrochemical applications, for example, energy storage devices. The very high solubility of CH3COOK allows us to obtain water-in-salt electrolyte concentrations, thus reducing ion activity and extending the cathodic stability of an aqueous electrolyte. At the same time, the presence of Li+ or Na+ makes these solutions compatible with intercalation materials for the development of rechargeable alkaline-ion batteries. Although there is a growing interest in these systems, a fundamental understanding of their physicochemical properties is still lacking. Here, we report and discuss the physicochemical and electrochemical properties of a series of solutions based on 20 mol kg-1 CH3COOK with different concentrations of CH3COONa. The most concentrated solution, 20 mol kg-1 CH3COOK + 7 mol kg-1 CH3COONa, gives the best compromise between transport properties and electrochemical stability, displaying a conductivity of 21.2 mS cm-1 at 25 °C and a stability window of up to 3 V in "ideal" conditions, i.e., using a small surface area and highly electrocatalytic electrode in a flooded cell. Careful Raman spectroscopy analyses help to address the interaction network, the phase evolution with temperature, and the crystallization kinetics.

8.
Chemistry ; 29(41): e202301000, 2023 Jul 20.
Article in English | MEDLINE | ID: mdl-37144646

ABSTRACT

Five new n-tetrabutylphosphonium (P4444 )+ cation-based ionic liquids (ILs) with oligoether substituted aromatic carboxylate anions have been synthesized. The nature and position of the oligoether chain affect thermal stability (up to 330 °C), phase behaviour (Tg <-55 °C) and ion transport. Furthermore, with the aim of application in lithium batteries, electrolytes were created for two of the ILs by 10 mol% doping using the corresponding Li-salts. This affects the ion diffusion negatively, from being higher and equal for cations and anions to lower for all ions and unequal. This is due to the stronger ionic interactions and formation of aggregates, primarily between the Li+ ions and the carboxylate group of the anions. Electrochemically, the electrolytes have electrochemical stability windows up to 3.5 V, giving some promise for battery application.

9.
J Cardiovasc Nurs ; 38(3): 262-271, 2023.
Article in English | MEDLINE | ID: mdl-37027131

ABSTRACT

BACKGROUND: Cardiovascular disease (CVD) risk reduction programs led by a nurse/community health worker team are effective in urban settings. This strategy has not been adequately tested in rural settings. OBJECTIVE: A pilot study was conducted to examine the feasibility of implementing an evidence-based CVD risk reduction intervention adapted to a rural setting and evaluate the potential impact on CVD risk factors and health behaviors. METHODS: A 2-group, experimental, repeated-measures design was used; participants were randomized to a standard primary care group (n = 30) or an intervention group (n = 30) where a registered nurse/community health worker team delivered self-management strategies in person, by phone, or by videoconferencing. Outcomes were measured at baseline and at 3 and 6 months. A sample of 60 participants was recruited and retained in the study. RESULTS: In-person (46.3%) and telephone (42.3%) meetings were used more than the videoconferencing application (9%). Mean change at 3 months differed significantly between the intervention and control groups for CVD risk (-1.0 [95% confidence interval (CI), -3.1 to 1.1] vs +1.4 [95% CI, -0.4 to 3.3], respectively), total cholesterol (-13.2 [95% CI, -32.1 to 5.7.] vs +21.0 [95% CI, 4.1-38.1], respectively), and low-density lipoprotein (-11.5 [95% CI, -30.8 to 7.7] vs +19.6 [95% CI, 1.9-37.2], respectively). No between-group differences were seen in high-density lipoprotein, blood pressure, or triglycerides. CONCLUSIONS: Participants receiving the nurse/community health worker-delivered intervention improved their risk CVD profiles, total cholesterol, and low-density lipoprotein levels at 3 months. A larger study to explore the intervention impact on CVD risk factor disparities experienced by rural populations is warranted.


Subject(s)
Cardiovascular Diseases , Nurses , Adult , Humans , Cardiovascular Diseases/prevention & control , Pilot Projects , Rural Population , Community Health Workers , Cholesterol , Lipoproteins, LDL
10.
J Biomed Mater Res A ; 111(7): 896-909, 2023 07.
Article in English | MEDLINE | ID: mdl-36861665

ABSTRACT

Mechanical cues from the extracellular matrix (ECM) regulate vascular endothelial cell (EC) morphology and function. Since naturally derived ECMs are viscoelastic, cells respond to viscoelastic matrices that exhibit stress relaxation, in which a cell-applied force results in matrix remodeling. To decouple the effects of stress relaxation rate from substrate stiffness on EC behavior, we engineered elastin-like protein (ELP) hydrogels in which dynamic covalent chemistry (DCC) was used to crosslink hydrazine-modified ELP (ELP-HYD) and aldehyde/benzaldehyde-modified polyethylene glycol (PEG-ALD/PEG-BZA). The reversible DCC crosslinks in ELP-PEG hydrogels create a matrix with independently tunable stiffness and stress relaxation rate. By formulating fast-relaxing or slow-relaxing hydrogels with a range of stiffness (500-3300 Pa), we examined the effect of these mechanical properties on EC spreading, proliferation, vascular sprouting, and vascularization. The results show that both stress relaxation rate and stiffness modulate endothelial spreading on two-dimensional substrates, on which ECs exhibited greater cell spreading on fast-relaxing hydrogels up through 3 days, compared with slow-relaxing hydrogels at the same stiffness. In three-dimensional hydrogels encapsulating ECs and fibroblasts in coculture, the fast-relaxing, low-stiffness hydrogels produced the widest vascular sprouts, a measure of vessel maturity. This finding was validated in a murine subcutaneous implantation model, in which the fast-relaxing, low-stiffness hydrogel produced significantly more vascularization compared with the slow-relaxing, low-stiffness hydrogel. Together, these results suggest that both stress relaxation rate and stiffness modulate endothelial behavior, and that the fast-relaxing, low-stiffness hydrogels supported the highest capillary density in vivo.


Subject(s)
Elastin , Hydrogels , Mice , Animals , Elastin/chemistry , Hydrogels/chemistry , Endothelial Cells , Extracellular Matrix/chemistry , Biocompatible Materials/pharmacology
11.
Nat Struct Mol Biol ; 30(3): 286-295, 2023 03.
Article in English | MEDLINE | ID: mdl-36747092

ABSTRACT

The glucocorticoid receptor (GR) is a ligand-activated transcription factor that binds DNA and assembles co-regulator complexes to regulate gene transcription. GR agonists are widely prescribed to people with inflammatory and autoimmune diseases. Here we present high-resolution, multidomain structures of GR in complex with ligand, DNA and co-regulator peptide. The structures reveal how the receptor forms an asymmetric dimer on the DNA and provide a detailed view of the domain interactions within and across the two monomers. Hydrogen-deuterium exchange and DNA-binding experiments demonstrate that ligand-dependent structural changes are communicated across the different domains in the full-length receptor. This study demonstrates how GR forms a distinct architecture on DNA and how signal transmission can be modulated by the ligand pharmacophore, provides a platform to build a new level of understanding of how receptor modifications can drive disease progression and offers key insight for future drug design.


Subject(s)
Receptors, Glucocorticoid , Transcription Factors , Humans , Receptors, Glucocorticoid/chemistry , Receptors, Glucocorticoid/genetics , Receptors, Glucocorticoid/metabolism , Ligands , Transcription Factors/metabolism , Gene Expression Regulation , DNA/metabolism
12.
J Natl Med Assoc ; 115(2): 101-118, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36775786

ABSTRACT

The purpose of our study is to examine the barriers and facilitators for urban African American students interested in pursuing health professions careers in the Midwest. In our analysis of the key informant interviews and focus groups, we identified four barriers (lack of preparation, lack of funding, lack of support/isolation, and perceived discrimination) and three facilitators (early preparation, support/mentorship, funding). We provide recommendations for how to leverage these facilitators and address the barriers to increase the representation of African Americans in the healthcare workforce. Novel future directions for this work should include comprehensive interventions tailored to URM students that span the health professions education pipeline and begin as early as elementary school. Interventions that engage mentors should take place at high school, undergraduate, and graduate health professions school levels.


Subject(s)
Black or African American , Career Choice , Diversity, Equity, Inclusion , Health Occupations , Students , Humans , Black or African American/psychology , Black or African American/statistics & numerical data , Health Occupations/education , Health Occupations/statistics & numerical data , Minority Groups/education , Minority Groups/psychology , Minority Groups/statistics & numerical data , Students/psychology , Students/statistics & numerical data , Urban Population/statistics & numerical data , Midwestern United States/epidemiology
13.
Chem Commun (Camb) ; 59(18): 2620-2623, 2023 Feb 28.
Article in English | MEDLINE | ID: mdl-36757288

ABSTRACT

Alkali metal salts usually have high melting points due to strong electrostatic interactions and solvents are needed to create ambient temperature liquid electrolytes. Here, we report on six phosphate-anion-based alkali metal salts, Li/Na/K, all of which are liquids at room temperature, with glass transition temperatures ranging from -61 to -29 °C, and are thermally stable up to at least 225 °C. While the focus herein is on various physico-chemical properties, these salts also exhibit high anodic stabilities, up to 6 V vs. M/M+ (M = Li/Na/K), and deliver some battery performance - at elevated temperatures as there are severe viscosity limitations at room-temperature. While the battery performance arguably is sub-par, solvent-free electrolytes based on alkali metal salts such as these should pave the way for conceptually different Li/Na/K-batteries, either by refined anion design or by using several salts to create eutectic mixtures.

14.
Phys Chem Chem Phys ; 25(4): 3502-3512, 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36637119

ABSTRACT

Five new ionic materials comprising fluorine-free aromatic heterocyclic anions based on pyridine and pyrazine combined with a common n-tetrabutylphosphonium cation, (P4444)+, result in two room temperature ionic liquids (RTILs), one semi-solid, and two organic ionic plastic crystals (OIPCs) with melting points >20 °C. The OIPCs showed a plastic crystalline phase, multiple solid-solid transitions, and plastic crystalline and melt phases. For both the neat RTILs and the Li+ conducting electrolytes, the nature and strength of the ion-ion interactions mainly depend on the position of the nitrogen atom with respect to the carboxylate group in the anions. Furthermore, for the RTILs the ionic conductivity is effected by the electronic structure and flexibility of the ions and the anions diffuse faster than the (P4444)+ cation, but are slowed down in the electrolytes due to the strong electrostatic interactions between the carboxylate group of the anions and the Li+, as shown both experimentally and computationally. Overall, this study describes the effect of structural tuning of aromatic anions on the ion-ion interactions and introduces new ionic materials with promising properties to be used as solid and liquid electrolytes in energy storage devices.

16.
RSC Adv ; 12(28): 18164-18167, 2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35800322

ABSTRACT

Single-ion conducting polymer electrolytes created by plasticizing LiPSTFSI with PPO and LiTFSI are shown to both improve the ionic conductivity and alter the ion conduction mechanism. This correlates with both local and macroscopic properties, opening for rational design of solid-state, but yet pliable electrolytes.

17.
Value Health ; 25(12): 1929-1938, 2022 12.
Article in English | MEDLINE | ID: mdl-35525833

ABSTRACT

OBJECTIVES: Striking disparities in access to radiation therapy (RT) exist, especially among racial and ethnic-minority patients. We analyzed census block group data to evaluate differences in travel distance to RT as a function of race and ethnicity, socioeconomic status, and rurality. METHODS: The Directory of Radiotherapy Centers provided the addresses of facilities containing linear accelerators for RT. We classified block groups as majority (≥ 50%) American Indian/Alaska Native (AI/AN), black, white, Asian, no single racial majority, or Hispanic regardless of race. We used the Area Deprivation Index to classify deprivation and Rural-Urban Commuting Area codes to classify rurality. Generalized linear mixed models tested associations between these factors and distance to nearest RT facility. RESULTS: Median distance to nearest RT facility was 72 miles in AI/AN-majority block groups, but 4 to 7 miles in block groups with non-AI/AN majorities. Multivariable models estimated that travel distances in AI/AN-majority block groups were 39 to 41 miles longer than in areas with non-AI/AN majorities. Travel distance was 1.3 miles longer in the more deprived areas versus less deprived areas and 16 to 32 miles longer in micropolitan, small town, and rural areas versus metropolitan areas. CONCLUSIONS: Cancer patients in block groups with AI/AN-majority populations, nonmetropolitan location, and low socioeconomic status experience substantial travel disparities in access to RT. Future research with more granular community- and individual-level data should explore the many other known barriers to access to cancer care and their relationship to the barriers posed by distance to RT care.


Subject(s)
Ethnicity , Humans , United States , Healthcare Disparities , Health Services Accessibility , Rural Population
18.
Sci Rep ; 12(1): 2692, 2022 02 17.
Article in English | MEDLINE | ID: mdl-35177639

ABSTRACT

Rodents living alongside humans increases the probability of encounter and also the transmission of rodent-borne diseases. Singapore's cosmopolitan urban landscape provides a perfect setting to study the prevalence of four rodent-borne pathogens: Seoul hantavirus (SEOV), Leptospira species, Rickettsia typhi and Yersinia pestis, and identify the potential risk factors which may influence rodent density and transmission of rodent-borne diseases. A total of 1143 rodents were trapped from 10 unique landscape structures throughout Singapore. Real-time quantitative Polymerase Chain Reactions were used to detect pathogenic and intermediate Leptospira spp. and Yersinia pestis, whereas the seroprevalence of SEOV and R. typhi were analysed by Enzyme-Linked Immunosorbent Assay and Immunofluorescence Assay respectively. Multivariable logistic regression analysis was used to evaluate the association between prevalence of infection in rodent reservoirs and risk factors. Most of the rodents were caught in public residential developments (62.2%). Among the tested rodents, 42.4% were infected with Leptospira spp., while 35.5% and 32.2% were seropositive for SEOV and R. typhi respectively, whereas Yersinia pestis was not detected. Furthermore, risk factors including habitat, species, gender, and weight of rodents, influenced prevalence of infection to a varying extent. This study highlights the presence of Leptospira spp., SEOV and R. typhi in Singapore's rodent population, suggesting the need for effective rodent management and sanitation strategies to prevent further circulation and transmission to humans.


Subject(s)
Disease Reservoirs , Rickettsia typhi , Seoul virus , Zoonoses/epidemiology , Animals , Humans , Leptospira , Rodentia , Seroepidemiologic Studies , Singapore/epidemiology
19.
J Med Chem ; 65(4): 3473-3517, 2022 02 24.
Article in English | MEDLINE | ID: mdl-35108001

ABSTRACT

Upregulation of the transcription factor Nrf2 by inhibition of the interaction with its negative regulator Keap1 constitutes an opportunity for the treatment of disease caused by oxidative stress. We report a structurally unique series of nanomolar Keap1 inhibitors obtained from a natural product-derived macrocyclic lead. Initial exploration of the structure-activity relationship of the lead, followed by structure-guided optimization, resulted in a 100-fold improvement in inhibitory potency. The macrocyclic core of the nanomolar inhibitors positions three pharmacophore units for productive interactions with key residues of Keap1, including R415, R483, and Y572. Ligand optimization resulted in the displacement of a coordinated water molecule from the Keap1 binding site and a significantly altered thermodynamic profile. In addition, minor reorganizations of R415 and R483 were accompanied by major differences in affinity between ligands. This study therefore indicates the importance of accounting both for the hydration and flexibility of the Keap1 binding site when designing high-affinity ligands.


Subject(s)
Kelch-Like ECH-Associated Protein 1/antagonists & inhibitors , Macrocyclic Compounds/pharmacology , NF-E2-Related Factor 2/antagonists & inhibitors , Animals , Binding Sites , Hepatocytes/metabolism , Humans , Ligands , Microsomes, Liver/metabolism , Models, Molecular , Molecular Docking Simulation , Rats , Signal Transduction/drug effects , Structure-Activity Relationship
20.
Chem Rev ; 122(12): 10899-10969, 2022 06 22.
Article in English | MEDLINE | ID: mdl-34529918

ABSTRACT

This is a critical review of artificial intelligence/machine learning (AI/ML) methods applied to battery research. It aims at providing a comprehensive, authoritative, and critical, yet easily understandable, review of general interest to the battery community. It addresses the concepts, approaches, tools, outcomes, and challenges of using AI/ML as an accelerator for the design and optimization of the next generation of batteries─a current hot topic. It intends to create both accessibility of these tools to the chemistry and electrochemical energy sciences communities and completeness in terms of the different battery R&D aspects covered.


Subject(s)
Artificial Intelligence , Machine Learning
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