High-pressure synthesis, structure, and characterization of a post-perovskite CaPtO3 with CaIrO3-type structure

A new ternary platinum oxide, CaPtO3 was synthesized under a pressure of 7 GPa and a temperature of 1000 degrees C. The crystal structure of CaPtO3 was determined by Rietveld analysis of the X-ray powder diffraction data. CaPtO3 has a layered CaIrO3-type structure (orthorhombic, space group: Cmcm), which is the same as that of a post-perovskite MgSiO3 in the Earth's lower mantle. The magnetic susceptibility data indicate that the Pt ion in CaPtO3 is tetravalent in the low spin state with an electron configuration of t2g(6)eg(0)(S = 0). This finding is consistent with the insulating behavior.     

Hydrogen Production System by Light-Induced α-FeOOH Coupled with Photoreduction

Solar-driven catalysts on semiconductors to produce hydrogen are considered as a means to solve environmental issues. In this study, H₂ production coupling with oxygen consumption by noble metal-free α-FeOOH was demonstrated even though the conduction band edge was lower than the reduction potential of H⁺ to H₂. For activation of α-FeOOH, an electron donor, Hg-Xe irradiation, and low pH (ca. 5) were indispensable factors. The H₂ production from H₂O was confirmed by GC-MS using isotope-labeled water (D₂O) and deuterated methanol. The α-FeOOH synthesized by coprecipitation method showed 25 times more active than TiO₂. The photocatalytic activity was stable for over 400 h. Our study suggests that α-FeOOH known as rust can produce H₂ by light induction.     

Efficacy of spectral presaturation of inversion recovery in evaluating delayed myocardial enhancement

OBJECTIVE: Delayed myocardial enhancement is caused by a variety of cardiovascular diseases. The extent of the enhanced area has been examined by the inversion recovery (IR) method, whereby at the inversion time (TI), normal myocardium shows a low signal intensity. In this sequence, as pericardial fat shows a very high intensity, a delayed enhancement just below the pericardium may be indistinct. To improve the accuracy of delayed myocardial enhancement, we employed the spectral presaturation of inversion recovery (SPIR) method. MATERIALS AND METHODS: Thirty-five patients with symptoms of cardiovascular disease aged between 36 and 80 years old (mean age, 62 years old) were investigated. Thirty were men and five were women. Inversion recovery and SPIR images were obtained 25 min after initial administration of a gadolinium-based contrast material. Each TI, when the signal intensity of the normal myocardium was null, was determined by images obtained at serial different TIs. A radiologist and a cardiologist examined each image by a consensus reading. The extent of myocardial enhancement was described as none, subendocardial, transmural and a random pattern in each case. Images were ranked over three levels and were based on whether myocardial enhancement could be easily detected or whether the contour of the myocardium was visualized precisely. Student's t-test was conducted to compare the quality of two sequences in all patients and in 22 patients who showed delayed myocardial enhancement. RESULTS: The imaging quality in evaluating delayed myocardial enhancement in all patients was superior with IR compared with SPIR, although it was not statistically significant. The imaging quality in the patients with delayed myocardial enhancement was similar between SPIR and IR. SPIR was superior to the IR sequence in two of the four patients who exhibited transmural enhancement. CONCLUSION: SPIR exhibited equivalent image quality to IR in evaluating delayed myocardial enhancement. As it has the potential advantage in patients with rich adipose tissue surrounding the myocardium, it can be an alternative sequence to evaluate myocardial viability.     

A Water‐Soluble Warped Nanographene: Synthesis and Applications for Photoinduced Cell Death

Nanographene, a small piece of graphene, has attracted unprecedented interest across diverse scientific disciplines particularly in organic electronics. The biological applications of nanographenes, such as bioimaging, cancer therapies and drug delivery, provide significant opportunities for breakthroughs in the field. However, the intrinsic aggregation behavior and low solubility of nanographenes, which stem from their flat structures, hamper their development for bioapplications. Herein, we report a water‐soluble warped nanographene (WNG) that can be easily synthesized by sequential regioselective C?H borylation and cross‐coupling reactions of the saddle‐shaped WNG core structure. The saddle‐shaped structure and hydrophilic tetraethylene glycol chains impart high water solubility to the WNG. The water‐soluble WNG possesses a range of promising properties including good photostability and low cytotoxicity. Moreover, the water‐soluble WNG was successfully internalized into HeLa cells and promoted photoinduced cell death.     

Aminolithiation–arylation consecutive cyclization of N-(2-fluorophenyl)methylaminoalkylstyryls giving aryl-substituted pyrido[1,2-b]isoquinolines

Aminolithiation–arylation tandem cyclization of N-(2-fluorophenyl)methylaminoalkylstyryls proceeded smoothly to give hexahydro-2H-pyrido[1,2-b]isoquinoline using a stoichiometric amount of n-BuLi with high trans selectivity. The arylation reaction was highly accelerated by the addition of HMPA. Both pyrido- and pyrrolo-[1,2-b]isoquinoline were successfully constructed by this tandem reaction.     

Preconcentration of diazinon using multiwalled carbon nanotubes as solid-phase extraction adsorbents

A sensitive and selective column adsorption method is proposed for the preconcentration and determination of diazinon. Diazinon was preconcentrated on multiwalled carbon nanotubes (MWCNTs) as an adsorbent and then determined by high-performance liquid chromatography (HPLC). Several parameters on the recovery of the analyte were investigated. The experimental results showed that it was possible to obtain quantitative analysis when the solution pH was 6 using 200 mL of validation solution containing 2 μg of diazinon and 5 mL of acetonitrile as an eluent. Recovery of diazinon was 95.2 ± 4.2% with a relative standard deviation for seven determinations of 4.9% under optimum conditions. The maximum preconcentration factor was 200 for diazinon when 1000 mL of sample solution volume was used. The linear range of calibration curve was 0.3 to 10,000 ng mL^− 1 with a correlation coefficient of 0.997 and the detection limit (3S/N) was 0.06 ng mL^− 1. The proposed method was successfully applied to the determination of diazinon in tap water with high precision and accuracy.     

Synthesis and properties of [9]cyclo-1,4-naphthylene: a π-extended carbon nanoring

The first synthesis of a π-extended carbon nanoring, [9]cyclo-1,4-naphthylene ([9]CN), has been achieved. Careful structure-property analyses uncovered a number of unique features of [9]CN that are quite different from those of [9]CPP, a simple carbon nanoring.     

Cycloparaphenylene‐Based Ionic Donor–Acceptor Supramolecule: Isolation and Characterization of Li+@C60⊂[10]CPP

The first cycloparaphenylene (CPP)‐based ionic donor–acceptor supramolecule Li⁺@C₆₀?[10]CPP?X^? has been synthesized. X‐ray crystallography not only confirmed the molecular structure of Li⁺@C₆₀?[10]CPP?X^? but also uncovered the formation of a unique ionic crystal. The strong charge‐transfer interaction between [10]CPP and Li⁺@C₆₀, which was confirmed by electrochemical measurement and spectroscopic analyses, caused significant delocalization of the positive charge across the entire complex.