Halogen‐Free πupiupi‐Conjugated Polymers Based on Thienobenzobisthiazole for Efficient Nonfullerene Organic Solar Cells: Rational Design for Achieving High Backbone Order and High Solubility

In π-conjugated polymers, a highly ordered backbone structure and solubility are always in a trade-off relationship that must be overcome to realize highly efficient and solution-processable organic photovoltaics (OPVs). Here, it is shown that a π-conjugated polymer based on a novel thiazole-fused ring, thieno[2′, 3′:5, 6]benzo[1, 2-d:4, 3-d′]bisthiazole (TBTz) achieves both high backbone order and high solubility due to the structural feature of TBTz such as the noncovalent interlocking of the thiazole moiety, the rigid and bent-shaped structure, and the fused alkylthiophene ring. Furthermore, based on the electron-deficient nature of these thiazole-fused rings, the polymer exhibits deep HOMO energy levels, which lead to high open-circuit voltages (VOCs) in OPV cells, even without halogen substituents that are commonly introduced into high-performance polymers. As a result, when the polymer is combined with a typical nonfullerene acceptor Y6, power conversion efficiencies of reaching 16% and VOCs of more than 0.84 V are observed, both of which are among the top values reported so far for “halogen-free” polymers. This study will serve as an important reference for designing π-conjugated polymers to achieve highly efficient and solution-processable OPVs

Involvement of Vascular Endothelial Cells in the Anti-atherogenic Effects of Liraglutide in Diabetic Apolipoprotein E-null Mice

Glucagon-like peptide 1 receptor agonists （GLP-1RAs） have been shown to exert anti-atherosclerotic effects via multiple mechanisms on different types of cells. However, it is unclear which of these mechanisms are crucial. We investigated the role of vascular endothelial cells （VECs） in the anti-atherogenic effects of the GLP-1RA liraglutide in a mouse model of atherosclerosis. Streptozotocin-induced diabetic apolipoprotein E-null mice were randomly assigned to treatment with either vehicle （saline） or liraglutide （107nmol/kg/day）, and were subjected to femoral artery wire injury to remove VECs. After 4 weeks, vessel samples were collected for analysis. Streptozotocin-injected mice had fasting plasma glucose levels of ＞300mg/dl and hemoglobin A1c levels of ＞9％, indicating that the injections had induced severe hyperglycemia. However, there were no differences in metabolic characteristics such as levels of hemoglobin A1c, fasting plasma glucose, total cholesterol, and triglycerides between the vehicle and liraglutide groups. Analysis of atherosclerotic plaque formation revealed that liraglutide treatment significantly suppressed plaque formation in the aorta. In addition, liraglutide treatment reduced plaque volume and intra-plaque macrophage accumulation at the aortic sinus. Furthermore, liraglutide treatment suppressed vascular expression of pro-inflammatory cytokines. In uninjured femoral arteries, no plaques were observed; however, severe plaque formation occurred in femoral arteries that had been injured by wire insertion to remove VECs. Unlike in the uninjured aorta, liraglutide treatment did not affect plaque volume or arterial remodeling （intimal and medial thinning, and arterial dilation） in wire-injured femoral arteries. Of the various cells that liraglutide affects, VECs play a central role in liraglutide’s anti-atherogenic effects in diabetic mice

Associations of Glucose and Blood Pressure Variability with Cardiac Diastolic Function in Patients with Type 2 Diabetes Mellitus and Hypertension: A Retrospective Observational Study

We evaluated the effects of glucose metabolism and blood pressure（BP） variability on cardiac diastolic function in patients with type 2 diabetes mellitus（T2DM） and hypertension. A total of 23 inpatients with T2DM underwent ambulatory BP monitoring（ABPM） and echocardiography. BP variability was assessed by measuring the mean BP and the standard deviation（SD） of systolic and diastolic BP over 24 hours, as well as daytime and nighttime ABPM. Cardiac diastolic function was assessed using the echocardiography E/e′ ratio. Participants had a mean age of 69.0±10.6 years, disease duration of 11.0±10.5 years, glycated hemoglobin（HbA1c） of 8.2％±1.3％, and glycated albumin（GA） of 22.0％±4.2％. Univariate analysis showed that the nighttime systolic BP, nighttime SDs of systolic and diastolic BP, urinary albumin, estimated glomerular filtration rate, and GA/HbA1c ratio were all significantly correlated with the E/e′ ratio. Moreover, stepwise multiple regression analysis identified nighttime SD of diastolic BP, urinary albumin, and GA/HbA1c ratio as independent contributors to the E/e′ ratio. In patients with T2DM and hypertension, cardiac diastolic function was associated with nighttime diastolic BP variability and the GA/HbA1c ratio

Effects of naturally occurring missense mutations and G525V in the hydratase domain of human d-bifunctional protein on hydratase activity

d-bifunctional protein (d-BP) deficiency is thought to lead to severe lipid metabolism disorders. To investigate the effect of naturally occurring missense mutations in the hydratase domain in d-BP, we constructed several d-BP hydratase variants and measured their activities. Missense mutations at sites whose conservation rates among 30 eukaryotes were < 70% did not affect hydratase activity. We predicted that missense mutations of highly conserved amino acids would markedly reduce activity. However, R562H and R562L, naturally occurring missense mutations of highly conserved amino acids, did not reduce activity. This result suggests that a missense mutation in a highly conserved amino acid does not always lead to severe lipid metabolism disorders. We also investigated the effect of G525V, which had been found in a mildly symptomatic patient with d-BP deficiency who was heterozygous for G525 and G658X. G525V markedly reduced hydratase activity. We had predicted that heterozygous G525V and G658X would lead to severely disordered lipid metabolism. However, the symptoms were inconsistent with this prediction. Characterizing mutations in the d-BP gene and the symptoms of d-BP deficiency may require pleiotropy, not only in vitro, studies

Residues at the Subunit Interfaces of the Nicotinic Acetylcholine Receptor That Contribute to α-Conotoxin M1 Binding

International audienceThe two binding sites in the pentameric nicotinic acetylcholine receptor of subunit composition alpha2 beta gamma delta are formed by nonequivalent alpha-gamma and alpha-delta subunit interfaces, which produce site selectivity in the binding of agonists and antagonists. We show by sedimentation analysis that 125I-alpha-conotoxin M1 binds with high affinity to the alpha-delta subunit dimers, but not to alpha-gamma dimers, nor to alpha, gamma, and delta monomers, a finding consistent with alpha-conotoxin M1 selectivity for the alpha delta interface in the intact receptor measured by competition against alpha-bungarotoxin binding. We also extend previous identification of alpha-conotoxin M1 determinants in the gamma and delta subunits to the alpha subunit interface by mutagenesis of conserved residues in the alpha subunit. Most mutations of the alpha subunit affect affinity similarly at the two sites, but Tyr93Phe, Val188Lys, Tyr190Thr, Tyr198Thr, and Asp152Asn affect affinity in a site-selective manner. Mutant cycle analysis reveals only weak or no interactions between mutant alpha and non-alpha subunits, indicating that side chains of the alpha subunit do not interact with those of the gamma or delta subunits in stabilizing alpha-conotoxin M1. The overall findings suggest different binding configurations of alpha-conotoxin M1 at the alpha-delta and alpha-gamma binding interfaces

Pronounced Backbone Coplanarization by π-Extension in a Sterically Hindered Conjugated Polymer System Leads to Higher Photovoltaic Performance in Non-Fullerene Solar Cells

Achieving both the backbone order and solubility of π-conjugated polymers, which are often in a trade-off relationship, is imperative for maximizing the performance of organic solar cells. Here, we studied three different π-conjugated polymers based on thiazolothiazole (PSTz₁ and POTz₁) and benzobisthiazole (PNBTz₁) that were combined with a benzodithiophene unit in the backbone, where PNBTz₁ was newly synthesized. Because of the steric hindrance between the side chains located on neighboring heteroaromatic rings, POTz₁ had a much less coplanar backbone than PSTz₁ in which such a steric hindrance is absent. However, POTz₁ showed higher photovoltaic performance in solar cells that used Y6 as the acceptor material. This was likely due to the significantly higher solubility of POTz₁ than PSTz₁, resulting in a better morphology. Interestingly, PNBTz₁ was found to have markedly higher backbone coplanarity than POTz1, despite having similar steric hindrance between the side chains, most likely owing to the more extended π-electron system, whereas PNBTz₁ had good solubility comparable to POTz₁. As a result, PNBTz₁ exhibited higher photovoltaic performance than POTz₁ in the Y6-based cells: specifically, the fill factor was significantly enhanced. Our results indicate that the backbone order and solubility can be achieved by the careful molecular design, which indeed leads to higher photovoltaic performance