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Poly(thienylene vinylene) (PTV) with high molecular weight was obtained via transition-metal-free and halogen-free polymerization, and the Brønsted acid doping of the PTV film was used for thermoelectric application.

The contractile function of skeletal muscle is essential for maintaining the vital activity of life. Muscular diseases such as muscular dystrophy severely compromise the quality of life of patients and ultimately lead to death. There is therefore an urgent need to develop therapeutic agents for these diseases. In a previous study, we showed that three-dimensional skeletal muscle tissues fabricated using the magnetic force-based tissue engineering technique exhibited contractile activity, and that drug effects could be evaluated based on the contractile activity of the skeletal muscle tissues. However, the reported method requires a large number of cells and the tissue preparation procedure is complex. It is therefore necessary to improve the tissue preparation method. In this study, a miniature device made of polydimethylsiloxane was used to simplify the production of contracting skeletal muscle tissues applicable to high-throughput screening. The effects of model drugs on the contractile force generation of skeletal muscle tissues prepared from mouse C2C12 myoblast and human induced pluripotent stem cells were evaluated using the miniature muscle device. The results indicated that the muscle device system could provide a useful tool for drug screening.

The reactivity of formaldehyde (HCHO) adsorbed in the supercages of zeolite NaY toward α-methylstyrene for the carbonyl-ene reaction was very dependent on the loading amount of HCHO in the NaY pores. We first prepared a series of NaY samples with different amounts of HCHO, and applied them to the carbonyl-ene reaction with excess amounts of α-methylstyrene to evaluate their intrinsic reactivities. It was found that one formaldehyde molecule adsorbed in one supercage of NaY produced 3-phenylbut-3-en-1-ol in the highest yield (83%), while for higher loading amounts of HCHO on NaY, lower yields of the product were obtained because the supercages were narrowed by the HCHO molecules as well as the homoallylic alcohol product and its over-reaction products. We next investigated their states of HCHO adsorbed in the pores by 13C DD/CP MAS NMR analysis. When three HCHO molecules were adsorbed in a supercage, it was clarified that all the HCHO was exclusively encapsulated in a monomeric form, while most of the adso...

We have so far developed a method for the controlled ring-opening polymerization of cyclotrisiloxane catalyzed by strong organobasic compounds to produce various chain-end functionalized polysiloxanes with controlled number-average molar mass (Mn) and narrow molar-mass dispersity (ÐM) values. In this study, well-defined α,ω-chain-end functionalized poly(dimethylsiloxane) with azide groups (N3-PDMS-N3) possessing a narrow ÐM range (ÐM = 1.04) and a relatively high Mn of up to 28.2 kg mol−1 was precisely synthesized in a mixed solvent of tetrahydrofuran (THF) and N,N-dimethylformamide (DMF) in the presence of quaternary ammonium salts as catalysts; N3-PDMS-N3 was obtained by converting α,ω-chain-end functionalized PDMS with bromomethyl groups (Br-PDMS-Br), which was prepared by polymerizing hexamethylcyclotrisiloxane (D3), water, and 1,3-trimethylene-2-n-propylguanidine (TMnPG) as the monomer, the initiator, and the catalyst, respectively. It was necessary to choose proper solvents depending on the Mn of Br-PDMS-Br to achieve the complete conversion of the bromomethyl groups by the azidation reaction. Moreover, we demonstrate the model reaction of copper-catalyzed 1,3-dipolar cycloaddition between N3-PDMS-N3 and phenylacetylene. As a result, the cycloadducted compound was exclusively obtained while maintaining a low ÐM value of 1.06 by employing copper(I) bromide and triethylamine as the catalyst and the ligand, respectively. This system was also effective for a polymer-polymer coupling reaction. Indeed, we successfully synthesized an ABA-type triblock copolymer where A and B are polystyrene (PS) and PDMS segments by reacting N3-PDMS-N3 with ω-chain-end functionalized PS with an alkynyl group.

Circulating tumor DNA (ctDNA) is emerging as a promising biomarker for cancer diagnosis. However, the system to detect gene mutations with very low frequencies from plasma remains to be established in terms of technical aspects of sequencing technologies and cost for universal use. One strategy is to employ a cancer sequencing panel to detect mutations in a primary tumor in a time- and cost-effective manner, and subsequently assess these mutations with a digital PCR technology from plasma ctDNA. This strategy enables the accurate detection of low frequency mutations (i.e., less than 1% allele frequency) from ctDNA, since both comprehensive coverage of genes and quantitative mutation detection with very low frequencies are required for cancer diagnosis from plasma samples. Here, we present a pipeline can be used to detect mutations from plasma ctDNA with very low allele frequencies using a next-generation sequencing technology for comprehensive coverage of primary tumors and droplet digital PCR for sensitive detection from plasma ctDNA.

A compact magnetic-mirror confined ECR plasma source for low-damage plasma processings was developed, especially aiming for the realization of high-quality silicon nitride film formation for the sub-micron CMOS device processes in the minimal fab system. Magnetically-confined plasma could be produced, and the wet-etch resistance against HF solution for the silicon nitride film formed at 400 °C was the same level as that of the film formed by the conventional LPCVD at 750 °C.

A mirror-field confined compact electron cyclotron resonance (ECR) plasma source using permanent magnets was developed, aiming for the realization of high-quality plasma processings where high-density reactive species are supplied to a substrate with minimizing the ion bombardment damages. The ECR position was located between a microwave transmissive window and a quartz limiter, and plasmas were transported from the ECR position to a midplane of the magnetic mirror field through the quartz limiter. Thus, a radius of core plasma could be determined by the limiter, which was 15 mm in this study. Plasma parameters were investigated by the Langmuir probe measurement. High-density plasma larger than 1011 cm−3 could be produced by applying 5.85-GHz microwave power of 10 W or more. For the outside region of the core plasma where a wafer for plasma processings will be set at, the ion current density was decreased dramatically with distance from the core plasma and became smaller by approximately two orders of mag...

Inúmeros cristais de titanita foram coletados na mina de cobre Khan, Namíbia, África. Eles foram analisados através da técnica de microssonda iônica de alta resolução e de alta sensibilidade (SHRIMP) no Laboratório de Geocronologia de Alta Resolução (GEOLab), do Instituto de Geociências da Universidade de São Paulo (IGc-USP), numa tentativa de serem utilizados como referência na determinação de razões 206Pb/238U de amostras desconhecidas. Neste experimento, foi utilizado como referência o padrão BLR1 (1.047 Ma), obtendo-se para o padrão interno Khan idade de 519 Ma. Tal valor é muito próximo das idades disponíveis na literatura especializada: idade 207Pb/206Pb de 518 ± 2 Ma e 522,3 ± 2,3 Ma (espectrômetro de massa de ionização térmica – Tims) e idade concórdia de 516,9 Ma (LA-ICP-MS). Os testes analíticos SHRIMP foram realizados em titanitas provenientes de duas amostras de rochas graníticas da Suíte Rio Piên, admitida como possível arco magmático, que baliza os terrenos Curitiba e Luis Alves (sul-sudeste brasileiro). A amostra MJ-649 acusou idade de 594 ± 5 Ma, e a amostra OM-629, idade de 616,6 ± 2,6 Ma. Tais valores são muito próximos às idades U-Pb obtidas em zircão através das técnicas SHRIMP e TIMS. Os erros obtidos nas idades U-Pb em titanitas são normalmente mais elevados que os obtidos em zircão em função da maior presença de Pb comum nas titanitas. Um maior número de medidas é aconselhável para a obtenção de uma precisão analítica aceitável. Em cristais de titanitas relativamente jovens (idades pós-neoproterozoicas), as idades 207Pb/206Pb são altamente imprecisas devido à elevada concentração de Pb comum; por outro lado, as idades 206Pb/238U apresentam valores bastante significativos. O desenvolvimento de análises em titanitas utilizando a técnica SHRIMP junto ao GEOLab-IGc-USP tem grande importância, principalmente quando acoplado a dados U-Pb obtidos em zircão e Ar-Ar em minerais, como anfibólio e biotita. Permite, além de um estudo geocronológico preciso, a obtenção de importantes parâmetros termocronológicos relacionados à ascensão/denudação de corpos rochosos.

An inert Pt(II)–pyridine bond is considerably labilized upon UV irradiation. On the basis of this phenomenon, kinetically inert Pt(II)-linked coordination rings and cages are formed in high yields from their components by obtaining a kinetically distributed mixture and subsequently equilibrating the mixture into the thermodynamically stable structures upon temporary photolabilization. This method is applicable when the pyridine rings in the ligands are not conjugated with other aromatic rings, in good agreement with DFT calculations that indicate the dependency of the photolability on the π-conjugation of the ligand frameworks. Interruption of π-conjugation either by introducing an methylene linker or by twisting the aromatic rings are effective to accomplish the photo-induced self-assembly.

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