Mitochondrial Structural Abnormalities and Cardiac Reverse Remodeling in Patients With Systolic Dysfunction.

BACKGROUND: Mitochondrial dysfunction in the heart is associated with the development of heart failure (HF). However, the clinical consequences of mitochondrial structural abnormalities in patients with HF remain unexplored. METHODS AND RESULTS: Ninety-one patients with left ventricular (LV) systolic dysfunction who underwent endomyocardial biopsy (EMB) were enrolled in the study. Myocardial specimens were obtained from the right ventricular septum. Specimens were characterized using electron microscopy to assess mitochondrial size, outer membrane disruption, and cristae disorganization. The primary endpoint was a composite of cardiovascular death and unplanned hospitalization for HF. Patients were classified into LV reverse remodeling (LVRR)-positive (n=52; 57.1%) and LVRR-negative (n=39; 42.9%) groups. Cristae disorganization was observed in 21 (23.1%) patients: 6 (11.5%) in the LVRR-positive group and 15 (38.5%) in the LVRR-negative group (P=0.005). During the 1-year post-EMB observation period, 16 patients (17.6%) met the primary endpoint, with 2 (2.2%) cardiovascular deaths and 14 (15.4%) HF hospitalizations. Cristae disorganization (P=0.002) was significantly associated with the endpoints, independent of age (P=0.115), systolic blood pressure (P=0.004), B-type natriuretic peptide level (P=0.042), and mitral regurgitation (P=0.003). CONCLUSIONS: We classified mitochondrial structural abnormalities and showed that cristae disorganization was associated with LVRR and worse prognosis. These findings may affect the management of patients with HF and systolic dysfunction who undergo EMB.

Synthesis and Properties of Dibenzo-Fused Naphtho[2,3-b:6,7-b']disilole and Naphtho[2,3-b:6,7-b']diphosphole.

Silole- and phosphole-containing polycyclic aromatic compounds have attracted significant attention in the field of organic functional materials. The structure of the aromatic units has great impact on the photophysical properties of the resulting silole- and phosphole-containing polycyclic aromatic compounds. Here, dibenzo-fused naphtho[2,3-b:6,7-b']disilole (NDS) and naphtho[2,3-b:6,7-b']diphosphole (NDP), where a naphthalene unit is arranged between two silole and phosphole units, respectively, were designed and synthesized. The solid-state structures of them were confirmed by X-ray crystallographic analysis. The photophysical properties were evaluated by UV-vis absorption and photoluminescence spectroscopies and compared with those of their related compounds, such as dibenzo-fused silolo[3,2-b]silole and benzo[1,2-b:4,5-b']disilole, ever reported. The longest wavelength absorption band of a series of silole-fused compounds was found to be red-shifted in the order benzo[1,2-b:4,5-b']disilole < NDS < silolo[3,2-b]silole derivatives. For a series of phosphole-fused compounds, π-extension from phospholo[3,2-b]phosphole to NDP derivatives induces the lower absorption coefficient of the longest wavelength absorption band and the red-shift of the second longest wavelength absorption band. Both NDS and NDP exhibit much lower fluorescence quantum yields than their related compounds.

Development of adeno-associated viral vectors targeting cardiac fibroblasts for efficient in vivo cardiac reprogramming.

Overexpression of cardiac reprogramming factors, including GATA4, HAND2, TBX5, and MEF2C (GHT/M), can directly reprogram cardiac fibroblasts (CFs) into induced cardiomyocytes (iCMs). Adeno-associated virus (AAV) vectors are widely used clinically, and vectors targeting cardiomyocytes (CMs) have been extensively studied. However, safe and efficient AAV vectors targeting CFs for in vivo cardiac reprogramming remain elusive. Therefore, we screened multiple AAV capsids and promoters to develop efficient and safe CF-targeting AAV vectors for in vivo cardiac reprogramming. AAV-DJ capsids containing periostin promoter (AAV-DJ-Postn) strongly and specifically expressed transgenes in resident CFs in mice after myocardial infarction (MI). Lineage tracing revealed that AAV-DJ-Postn vectors expressing GHT/M reprogrammed CFs into iCMs, which was further increased 2-fold using activated MEF2C via the fusion of the powerful MYOD transactivation domain (M-TAD) with GHT (AAV-DJ-Postn-GHT/M-TAD). AAV-DJ-Postn-GHT/M-TAD injection improved cardiac function and reduced fibrosis after MI. Overall, we developed new AAV vectors that target CFs for cardiac reprogramming.

Cardiac reprogramming reduces inflammatory macrophages and improves cardiac function in chronic myocardial infarction.

Cardiomyocytes (CMs) have little regenerative capacity. After myocardial infarction (MI), scar formation and myocardial remodeling proceed in the infarct and non-infarct areas, respectively, leading to heart failure (HF). Prolonged activation of cardiac fibroblasts (CFs) and inflammatory cells may contribute to this process; however, therapies targeting these cell types remain lacking. Cardiac reprogramming converts CFs into induced CMs, reduces fibrosis, and improves cardiac function in chronic MI through the overexpression of Mef2c/Gata4/Tbx5/Hand2 (MGTH). However, whether cardiac reprogramming reduces inflammation in infarcted hearts remains unclear. Moreover, the mechanism through which MGTH overexpression in CFs affects inflammatory cells remains unknown. Here, we showed that inflammation persists in the myocardium until three months after MI, which can be reversed with cardiac reprogramming. Single-cell RNA sequencing demonstrated that CFs expressed pro-inflammatory genes and exhibited strong intercellular communication with inflammatory cells, including macrophages, in chronic MI. Cardiac reprogramming suppressed the inflammatory profiles of CFs and reduced the relative ratios and pro-inflammatory signatures of cardiac macrophages. Moreover, fluorescence-activated cell sorting analysis (FACS) revealed that cardiac reprogramming reduced the number of chemokine receptor type 2 (CCR2)-positive inflammatory macrophages in the non-infarct areas in chronic MI, thereby restoring myocardial remodeling. Thus, cardiac reprogramming reduced the number of inflammatory macrophages to exacerbate cardiac function after MI.

Dopamine as a polymerizable reagent for enzyme-linked immunosorbent assay using horseradish peroxidase.

We demonstrate that dopamine can be used as a reagent for colorimetric enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase (HRP). Dopamine was able to be polymerized in the presence of HRP and H2O2, and black polydopamine was obtained after the enzymatic reaction. Because of the black color, the absorbance was significantly changed in the whole range of the visible light region. Here, an indirect competitive ELISA based on the polymerization of dopamine was performed to detect a fluoroquinolone antibiotic, enrofloxacin. The antibiotic is commonly used in livestock farming. The anti-antibiotics antibody was produced from egg yolk from chicken hens. In the visible range, sufficient absorbance changes of ∼0.4∼0.5 and a low background level for the ELISA response were obtained, and the 50 % inhibitory concentration value at 450 nm was determined to be 26 ppb. The performance of the indirect competitive ELISA based on the polymerization of dopamine was compared to that based on the oxidation of catechol because dopamine has a catechol skeleton. By the complex of HRP and H2O2, catechol can be oxidized to o-benzoquinone having a maximum absorption wavelength of 420 nm. It was shown that the absorbance change in the case of polydopamine was about 2.5 times higher than that of catechol, where the background levels were similar. This confirms that the polymerization of dopamine significantly enhanced the photosignal.

Monomer and Excimer Emission in Electrogenerated Chemiluminescence of Pyrene and 2,7-Di-tert-butylpyrene Associated with Electron Transfer Distance.

Electrogenerated chemiluminescence (ECL) is a light emission phenomenon caused by electrochemically generated radical anions (R•-) and cations (R•+), in which the ion annihilation results in the formation of a pair of excited (R*) and ground state (R) of a luminescent molecule. Here, the ECL properties of pyrene (Py) and 2,7-di-tert-butylpyrene (di-t-BuPy) are reported. It was found that at a commonly employed concentration (1 mM), the ECL spectra were time-dependent because of increasing the oligomer emission and increasing the concentration of R near R*, leading to an enhancement of the excimer emission. At a low concentration range (20-30 µM), the shape of the ECL spectra containing the monomer and excimer emission was determined by isolated pairs of R* and R, which were generated through ion annihilation of R•- and R•+. It was found that in the ECL of Py and di-t-BuPy originated from the isolated pairs of R•- and R•+, 58 and 48% of the excited states were the excimer states, respectively. Diffusion equation analysis indicates that the lower excimer formation in the case of di-t-BuPy is because of a farther initial separation distance between R* and R, i.e., a longer electron transfer distance between the radical ions. The Marcus model for the electron transfer kinetics suggests that the farther electron transfer distance is mainly caused by the larger molecular size, which resulted in a smaller reorganization energy of the solvent acetonitrile molecule. Taking advantage of the photophysical and electrochemical properties of Py and di-t-Bu Py, the monomer and excimer emission in ECL is discussed.

Flk1 Deficiency and Hypoxia Synergistically Promote Endothelial Dysfunction, Vascular Remodeling, and Pulmonary Hypertension.

BACKGROUND: The mechanisms underlying pulmonary hypertension (PH) remain largely unknown; further, why advanced vascular remodeling preferentially occurs in arterioles is yet to be answered. VEGF (vascular endothelial growth factor) regulates angiogenesis through Flk1 (fetal liver kinase 1) and Flt1 (fms-like tyrosine kinase 1) on endothelial cells (ECs), which may be related to PH pathogenesis. However, spatiotemporal expression patterns of Flk1 and Flt1 in the pulmonary vascular system and the role of endothelial Flk1 in PH development remain poorly understood. METHODS: We analyzed multiple reporter mice, including Flk1-GFP (green fluorescent protein) bacterial artificial chromosome transgenic (Tg), Flt1-DsRed bacterial artificial chromosome Tg, and Flk1-GFP/Flt1-DsRed double Tg mice, to determine the spatiotemporal expression of Flk1 and Flt1 in hypoxia-induced PH. We also used Cdh5CreERT2/Flk1f/f/Tomato (Flk1-KO [knockout]) mice to induce EC-specific Flk1 deletion and lineage tracing in chronic hypoxia. RESULTS: Flk1 was specifically expressed in the ECs of small pulmonary vessels, including arterioles. Conversely, Flt1 was more broadly expressed in the ECs of large- to small-sized vessels in adult mouse lungs. Intriguingly, Flk1+ ECs were transiently increased in hypoxia with proliferation, whereas Flt1 expression was unchanged. Flk1-KO mice did not exhibit pulmonary vascular remodeling nor PH in normoxia; however, the arteriolar ECs changed to a cuboidal shape with protrusion. In hypoxia, Flk1 deletion exacerbated EC dysfunction and reduced their number via apoptosis. Additionally, Flk1 deletion promoted medial thickening and neointimal formation in arterioles and worsened PH. Mechanistically, lineage tracing revealed that neointimal cells were derived from Flk1-KO ECs. Moreover, RNA sequencing in pulmonary ECs demonstrated that Flk1 deletion and hypoxia synergistically activated multiple pathways, including cell cycle, senescence/apoptosis, and cytokine/growth factor, concomitant with suppression of cell adhesion and angiogenesis, to promote vascular remodeling. CONCLUSIONS: Flk1 and Flt1 were differentially expressed in pulmonary ECs. Flk1 deficiency and hypoxia jointly dysregulated arteriolar ECs to promote vascular remodeling. Thus, dysfunction of Flk1+ ECs may contribute to the pathogenesis of advanced vascular remodeling in pulmonary arterioles.

DUPAN-2 as a Risk Factor of Early Recurrence After Curative Pancreatectomy for Patients With Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Several patients with pancreatic ductal adenocarcinoma (PDAC) experience postoperative early recurrence (ER). We evaluated PDAC patients to identify the risk factors for postoperative ER (≤6 months), including preoperative serum DUPAN-2 level. METHODS: We retrospectively evaluated 74 PDAC patients who underwent pancreatectomy with curative intent. Clinicopathological factors including age, sex, body mass index, postoperative complications, pathological factors, preoperative C-reactive protein/albumin ratio, neutrophil/lymphocyte ratio, modified Glasgow prognostic score, preoperative tumor markers (carcinoembryonic antigen, carbohydrate antigen 19-9, SPAN-1, and DUPAN-2), and history of adjuvant chemotherapy were investigated. Early recurrence risk factors were determined using multivariate logistic regression analysis. RESULTS: Recurrence and ER occurred in 52 (70.3%) and 23 (31.1%) patients, respectively. Univariate analysis revealed that postoperative complications, C-reactive protein/albumin ratio ≥0.02, neutrophil/lymphocyte ratio ≥3.01, carbohydrate antigen 19-9 ≥ 92.3 U/mL, SPAN-1 ≥ 69 U/mL, DUPAN-2 ≥ 200 U/mL, and absence of adjuvant chemotherapy were significant risk factors for ER. In multivariate analysis, DUPAN-2 ≥ 200 U/mL (P = 0.04) and absence of adjuvant chemotherapy (P = 0.02) were identified as independent risk factors for ER. CONCLUSIONS: A higher level of preoperative DUPAN-2 was an independent risk factor for ER. For patients with high DUPAN-2 level, neoadjuvant therapies might be required to avoid ER.

MEF2C/p300-mediated epigenetic remodeling promotes the maturation of induced cardiomyocytes.

Cardiac transcription factors (TFs) directly reprogram fibroblasts into induced cardiomyocytes (iCMs), where MEF2C acts as a pioneer factor with GATA4 and TBX5 (GT). However, the generation of functional and mature iCMs is inefficient, and the molecular mechanisms underlying this process remain largely unknown. Here, we found that the overexpression of transcriptionally activated MEF2C via fusion of the powerful MYOD transactivation domain combined with GT increased the generation of beating iCMs by 30-fold. Activated MEF2C with GT generated iCMs that were transcriptionally, structurally, and functionally more mature than those generated by native MEF2C with GT. Mechanistically, activated MEF2C recruited p300 and multiple cardiogenic TFs to cardiac loci to induce chromatin remodeling. In contrast, p300 inhibition suppressed cardiac gene expression, inhibited iCM maturation, and decreased the beating iCM numbers. Splicing isoforms of MEF2C with similar transcriptional activities did not promote functional iCM generation. Thus, MEF2C/p300-mediated epigenetic remodeling promotes iCM maturation.

Direct Reprogramming Improves Cardiac Function and Reverses Fibrosis in Chronic Myocardial Infarction.

BACKGROUND: Because adult cardiomyocytes have little regenerative capacity, resident cardiac fibroblasts (CFs) synthesize extracellular matrix after myocardial infarction (MI) to form fibrosis, leading to cardiac dysfunction and heart failure. Therapies that can regenerate the myocardium and reverse fibrosis in chronic MI are lacking. The overexpression of cardiac transcription factors, including Mef2c/Gata4/Tbx5/Hand2 (MGTH), can directly reprogram CFs into induced cardiomyocytes (iCMs) and improve cardiac function under acute MI. However, the ability of in vivo cardiac reprogramming to repair chronic MI with established scars is undetermined. METHODS: We generated a novel Tcf21iCre/reporter/MGTH2A transgenic mouse system in which tamoxifen treatment could induce both MGTH and reporter expression in the resident CFs for cardiac reprogramming and fibroblast lineage tracing. We first tested the efficacy of this transgenic system in vitro and in vivo for acute MI. Next, we analyzed in vivo cardiac reprogramming and fusion events under chronic MI using Tcf21iCre/Tomato/MGTH2A and Tcf21iCre/mTmG/MGTH2A mice, respectively. Microarray and single-cell RNA sequencing were performed to determine the mechanism of cardiac repair by in vivo reprogramming. RESULTS: We confirmed the efficacy of transgenic in vitro and in vivo cardiac reprogramming for acute MI. In chronic MI, in vivo cardiac reprogramming converted ≈2% of resident CFs into iCMs, in which a majority of iCMs were generated by means of bona fide cardiac reprogramming rather than by fusion with cardiomyocytes. Cardiac reprogramming significantly improved myocardial contraction and reduced fibrosis in chronic MI. Microarray analyses revealed that the overexpression of MGTH activated cardiac program and concomitantly suppressed fibroblast and inflammatory signatures in chronic MI. Single-cell RNA sequencing demonstrated that resident CFs consisted of 7 subclusters, in which the profibrotic CF population increased under chronic MI. Cardiac reprogramming suppressed fibroblastic gene expression in chronic MI by means of conversion of profibrotic CFs to a quiescent antifibrotic state. MGTH overexpression induced antifibrotic effects partly by suppression of Meox1, a central regulator of fibroblast activation. CONCLUSIONS: These results demonstrate that cardiac reprogramming could repair chronic MI by means of myocardial regeneration and reduction of fibrosis. These findings present opportunities for the development of new therapies for chronic MI and heart failure.

The Synthesis and Properties of Ladder-Type π-Conjugated Compounds with Pyrrole and Phosphole Rings.

The phosphole ring is known as a useful building block for constructing π-conjugated organic materials. Here, we report ladder-type benzophospholo[3,2-b]indole (BPI) derivatives where the phosphole and the pyrrole rings are directly fused. Compounds 8a-8d with different aryl groups on the phosphorous center were successfully synthesized, and the solid-state structure of 8a was confirmed using X-ray crystallographic analysis. The BPIs exhibit relatively high fluorescence quantum yield (Φ 0.50-0.72) and demonstrate a larger Stokes shift compared with a series of benzophospholo[3,2-b]benzoheteroles. The benzophospholo[3,2-b]carbazole derivative 9, which possesses a benzene ring between the phosphole and the pyrrole rings of the BPI, was also synthesized, and its solid-state structure was confirmed using X-ray crystallographic analysis. Compound 9 was found to show a smaller Stokes shift compared with the BPI.

Maximum Diameter of the Gallbladder Determined Presurgically Using Computed Tomography as a Risk Factor for Difficult Emergency Laparoscopic Cholecystectomy in Patients With Mild to Moderate Acute Cholecystitis.

BACKGROUND: Early or emergency laparoscopic cholecystectomy (LC) was recommended in the 2018 Tokyo Guidelines for patients with mild to moderate acute cholecystitis (AC). Although surgical difficulty is frequently encountered during these surgeries, risk factors for predicting surgical difficulties have not been fully investigated, especially based on computed tomography (CT) findings. MATERIALS AND METHODS: We investigated 72 patients who underwent emergency LC with mild (n=45) to moderate (n=27) AC. Patients who previously underwent presurgical percutaneous or endoscopic biliary drainage were excluded from this study. Difficult LC was defined using any of the following surgical factors: surgical duration ≥180 minutes, blood loss ≥300 g, or a conversion to open cholecystectomy. Subsequently, several presurgical clinical factors were analyzed, including sex, age at surgery, experience of the surgeon, interval between symptom onset and surgery, body mass index, diabetes history, presurgical white blood cell count, and C-reactive protein level. Moreover, stones in the cystic duct or perigallblader fluid and the maximum thickness and diameter of the gallbladders were evaluated via presurgical CT. Finally, logistic regression analysis was performed to compare the relationship between surgical difficulty and each clinical factor. RESULTS: The average age at surgery of the included patients was 60.3 (range: 25 to 88 y), surgical duration was 112.2 (range: 29 to 296 min), and surgical blood loss was 55.2 (range: 0 to 530 g). Furthermore, 4 (5.6%) had to undergo open cholecystectomy, whereas postsurgical complications occurred in 5 (6.9%) patients. In addition, the mean postsurgical admission duration was 7 (range: 3 to 63 d). Thus, 12 patients experienced difficult LC, whereas 60 experienced nondifficult LC. Of the evaluated clinical factors, patients who experienced difficult LC showed higher presurgical C-reactive protein levels (10.78 vs. 6.76 mg/dL, P =0.01) and wider gallbladder diameters (48.4 vs. 41.8 mm, P <0.01) than those who experienced nondifficult LC. By univariate logistic regression analysis, results also showed that patients with a maximum gallbladder diameter had a higher risk of experiencing difficulty during emergency LC ( P =0.02). Moreover, the gallbladder diameter's cutoff value was 43 mm after the receiver operating characteristic curve analysis. CONCLUSIONS: In patients with mild to moderate AC, emergency LC can safely be performed. However, performing LC might be technically difficult in patients with AC after the identification of severe gallbladder swelling during presurgical CT.

Furan-Containing Chiral Spiro-Fused Polycyclic Aromatic Compounds: Synthesis and Photophysical Properties.

Spiro-fused polycyclic aromatic compounds (PACs) have received growing interest as rigid chiral scaffolds. However, furan-containing spiro-fused PACs have been quite limited. Here, we design spiro[indeno[1,2-b][1]benzofuran-10,10'-indeno[1,2-b][1]benzothiophene] as a new family of spiro-fused PACs that contains a furan unit. The compound was successfully synthesized in enantiopure form and also transformed to its S,S-dioxide derivative and the pyrrole-containing analog via aromatic metamorphosis. The absorption and emission properties of the obtained furan-containing chiral spiro-fused PACs are apparently different from those of their thiophene analogs that have been reported, owing to the increased electron-richness of furan compared to thiophene. All of the furan-containing chiral spiro-fused PACs were found to be circularly polarized luminescent materials.

Prognostic significance of intrahepatic lymphatic invasion in colorectal liver metastases.

BACKGROUND: Intrahepatic lymphatic invasion is an adverse prognostic factor after hepatectomy for colorectal liver metastases (CLMs). However, most patients in previous reports had liver resection before the era of FOLFOX/FIRI-based chemotherapy. METHODS: Forty-six patients who underwent hepatectomy for CLMs from 2004 to 2020 were evaluated. We histologically evaluated portal invasion, intrahepatic lymphatic invasion, and biliary invasion on hematoxylin-eosin slides. We also collected the following clinicopathologic factors: gender, age, timing, the number and maximum size of CLMs, preoperative tumor markers, neutrophil/lymphocyte ratio, location, and lymph node metastases of primary cancer, and chemotherapy after hepatectomy. A multivariate Cox proportional hazard model was used to define the relationship between overall (OS) or disease-free survival (DFS) and clinicopathologic factors. RESULTS: Histological invasions were portal invasion in 8 (17.4 %), intrahepatic lymphatic invasion in 6 (13.0 %), and biliary invasion in 5 (10.9 %). Chemotherapy for recurrence after hepatectomy (n = 29) was performed in 22 and 14 of those who received FOLFOX/FIRI-based chemotherapy. By multivariate analysis, the number of CLMs (p < 0. 01) and presence of intrahepatic lymphatic invasion (p = 0.02) were independent predictors of recurrence. The number of CLMs (p = 0.02) and prehepatectomy carcinoembryonic antigen level (p = 0.02), but not intrahepatic lymphatic invasion (p = 0.18), were independent predictors of survival using multivariate analysis. CONCLUSIONS: The presence of intrahepatic lymphatic invasion adversely affected patient's DFS, but not OS in patients with CLMs in the era of FOLFOX/FIRI chemotherapy. FOLFOX/FIRI-based chemotherapy might improve OS, even in patients with positive intrahepatic lymphatic invasion.

Macrophage behaviour 72 hours after implantation of biodegradable polymer-based sirolimus-eluting stent in a case of ST elevation myocardial infarction.

While the vascular healing process after drug-eluting stent implantation is not fully elucidated, it is generally accepted that macrophages play an important role in inflammation. It is also known that macrophages involved in the pathogenesis of atherosclerosis may stem from several origins, that is, monocyte-derived macrophages versus resident macrophages. However, little is known about the role of human macrophages on reperfusion of culprit coronary arteries in patients with atherosclerotic disease who have sustained acute coronary syndrome. In this present case report, we describe the presence of cluster of differentiation (CD) 163-positive macrophages in close proximity to the stent struts at the luminal site 72 hours after drug-eluting stent implantation in the culprit coronary lesion for ST elevation myocardial infarction by postmortem examination.

Transformation of Thia[7]helicene to Aza[7]helicenes and [7]Helicene-like Compounds via Aromatic Metamorphosis.

[n]Helicenes with helically twisted structures have attracted increasing interest owing to their unique properties. Therefore, it has been an important issue to develop facile synthetic methodologies which allow access to a variety of [n]helicenes. Here we report the synthesis of [7]helicenes and [7]helicene-like compounds from the thia[7]helicene as a common starting material. Desulfurative dilithiation of the thia[7]helicene and the subsequent reaction with silicon and phosphorus electrophiles afforded the silole- and phosphole-fused [7]helicene-like compounds, respectively. The cyclopentadiene-fused [7]helicene-like compound and the pyrrole-fused aza[7]helicenes were also successfully synthesized via twofold SNAr reactions of the thia[7]helicene S,S-dioxide with the carbon and nitrogen nucleophiles, respectively. The thia[7]helicene S,S-dioxide showed a slightly red-shifted absorption spectrum than the parent thia[7]helicene, which was well demonstrated by the theoretical calculations. The substituents on the silicon atom of silole-fused [7]helicene-like compounds have little impact on the longest absorption maximum. Such little effect of the substituents on absorption properties was also observed for cyclopentadiene-fused [7]helicene-like compounds and aza[7]helicenes and was well demonstrated by the theoretical calculations. The thia[7]helicene S,S-dioxide and the silole-fused [7]helicene-like compound exhibited bright blue emission, and the cyclopentadiene-fused [7]helicene-like compound and the aza[7]helicenes showed strong violet emission. Each single enantiomer of the aza[7]helicenes showed circularly-polarized luminescence with the dissymmetry factors of 4.2~4.4 × 10-3.

Synthesis and Properties of Spiro-double Sila[7]helicene: The LUMO Spiro-conjugation.

A double helicene with a spiro-Si linker (4) was synthesized by four successive nucleophilic substitutions on SiCl4 . Its (P,P), (M,M) and (P,M) isomers were isolated and characterized by single crystal X-ray analysis. Due to the central spirosilabi[fluorene] moiety, the two helicene units in 4 are symmetrically and nearly perpendicularly arranged. (P,P)-4 and (M,M)-4 exhibit unique optical properties attributable to the LUMO spiro-conjugation between the two sila[7]helicene units.

Chiral Benzo[b]silole-Fused 9,9'-Spirobi[fluorene]: Synthesis, Chiroptical Properties, and Transformation to π-Extended Polycyclic Arene.

Chiral spiro π-conjugated compounds have emerged as a new class of circularly polarized luminescent organic materials. Here we report the synthesis and (chir)optical properties of a chiral benzo[b]silole-fused 9,9'-spirobi[fluorene] (SBF) and π-extended spiro polycyclic arene. The benzo[b]silole-fused SBF was successfully synthesized by a rhodium-catalyzed intramolecular silylative cyclization. It was further transformed to the chiral π-extended spiro polycyclic arene by an annulative π-extension reaction. Less effective spiroconjugation was observed for these spiro compounds through UV-Vis absorption spectroscopy and theoretical calculations. They exhibit circularly polarized luminescence with the dissymmetry factors of up to 0.76×10-3 . Theoretical calculations demonstrate that emission of the benzo[b]silole-fused SBF occurs from one subunit, the structure of which is slightly different from that in the Frank-Condon state.

Aromatic Metamorphosis of Thiophenes by Means of Desulfurative Dilithiation.

A new mode of aromatic metamorphosis has been developed, which allows thiophenes and their benzo-fused derivatives to be converted to a variety of exotic heteroles. This transformation involves 1) the efficient generation of key 1,4-dianions by means of desulfurative dilithiation with lithium powder and 2) the subsequent trapping of the dianions with heteroatom electrophiles in a one-pot manner. Via the desulfurative dilithiation, the sulfur atoms of thiophenes are replaced also with a carbon-carbon double bond or a 1,2-phenylene for the construction of benzene rings.

Enzyme-linked immunosorbent assay based on light absorption of enzymatically generated aniline oligomer: Flow injection analysis for 3-phenoxybenzoic acid with anti-3-phenoxybenzoic acid monoclonal antibody.

A flow enzyme-linked immunosorbent assay (ELISA) method based on light absorption by enzymatically generated aniline oligomer in the presence of horseradish peroxidase (HRP), H2O2, and aniline is proposed. Aniline oligomer is rapidly formed through the polymerization reaction via the enzymatic reaction, and its fast reaction rate is beneficial for flow ELISA. An anti-3-phenoxybenzoic acid monoclonal antibody (mAb) was produced by mice, and was used for the flow competitive ELISA for the determination of 3-phenoxybenzoic acid (3PBA), which was performed on an acrylic plate having a Y-shaped channel. ABS resin beads (d = 1 mm) were filled in the channel to increase the surface area for the adsorption of the mAb. A clank-type detection chamber (optical length: 1 cm) made of polydimethylsiloxane (PDMS) containing carbon black, which can significantly decrease light scattering, was fabricated with a 3D printer. The PDMS detection chamber was connected to the outlet of the acrylic flow chip with a tube. A blue LED was used as a light source for the flow ELISA. The inhabitation concentration at 50% and the detection range (absorbance change from 90 to 10%) for the proposed flow competitive ELISA were 0.5 ppm and 0.05-5 ppm, respectively. We also performed the flow competitive ELISA in an artificial and real urine, and no significant matrix effect of the urine samples on the ELISA was found.