Deep learning-based identification of sinoatrial node-like pacemaker cells from SHOX2/HCN4 double-positive cells differentiated from human iPS cells.

Background: Cardiomyocytes derived from human iPS cells (hiPSCs) include cells showing SAN- and non-SAN-type spontaneous APs.

Objectives: To examine whether the deep learning technology could identify hiPSC-derived SAN-like cells showing SAN-type-APs by their shape.

Methods: We acquired phase-contrast images for hiPSC-derived SHOX2/HCN4 double-positive SAN-like and non-SAN-like cells and made a VGG16-based CNN model to classify an input image as SAN-like or non-SAN-like cell, compared to human discriminability.

Prediction of conversion to Alzheimer's disease using deep survival analysis of MRI images.

The prediction of the conversion of healthy individuals and those with mild cognitive impairment to the status of active Alzheimer's disease is a challenging task. Recently, a survival analysis based upon deep learning was developed to enable predictions regarding the timing of an event in a dataset containing censored data. Here, we investigated whether a deep survival analysis could similarly predict the conversion to Alzheimer's disease.

Visualization of cancer-related chemical components in mouse pancreas tissue by tapping-mode scanning probe electrospray ionization mass spectrometry.

Mass spectrometry imaging is an informative approach for the comprehensive analysis of multiple components inside biological specimens. We used novel tapping-mode scanning probe electrospray ionization mass spectrometry method to visualize cancer-related chemical components in the mouse pancreas tissue section at a sampling pitch of 100 µm. Positive ion mode measurements from m/z 100 to 1500 resulted in the visualization of multiple components that are tentatively assigned as polyamines, lipids and proteins.

Correction: Imaging mass spectrometry of a mouse brain by tapping-mode scanning probe electrospray ionization.

Correction for 'Imaging mass spectrometry of a mouse brain by tapping-mode scanning probe electrospray ionization' by Yoichi Otsuka et al., Analyst, 2014, 139, 2336-2341.

Imaging mass spectrometry of a mouse brain by tapping-mode scanning probe electrospray ionization.

Methods for ambient sampling and ionization enable chemical information to be obtained with minimal sample preparation. Also, imaging mass spectrometry (IMS) enables the spatial distribution of multiple components to be determined by a single measurement. Here, we report an improved method of tapping-mode scanning probe electrospray ionization (t-SPESI) for ambient sampling and ionization in which probe oscillation is stabilized by using a piezo actuator.

Scanning probe electrospray ionization for ambient mass spectrometry.

Rationale: Ambient sampling and ionization techniques have been attracting attention in imaging mass spectrometry because they offer the advantage of rapid testing. We have developed a method which exploits the fluid motion of charged solvents for both local sampling and ionization with a single vibrating capillary probe.

Methods: The capillary probe was used to supply solvents in order to form a liquid bridge between the probe and a sample surface.

Recombination of an Fe-Si-P linkage to an Fe-P-Si linkage through an isolable intermediate phosphasilaferracyclopropane.

Phosphasilaferracycle [Cp*(CO)Fe{kappa(2)Si,P-SiMe(2)PPh(2)}], prepared upon irradiation of [Cp*(CO)(2)FeSiMe(2)PPh(2)], was converted to [Cp*(CO)(2)FeP(Ph)SiMe(2)Ph] under mild conditions. The unusual recombination of the iron, silicon, and phosphorus cores could be achieved through a sequence of 1,2- and 1,3-group migrations in an FeSiP system.

Stereoselective synthesis of 2,3,7-trimethylcyclooctanone and related compounds and determination of their relative and absolute configurations by the MalphaNP acid method.

The copper/chiral phosphoramidite (L(1))-catalyzed conjugate addition of dimethylzinc to cycloocta-2,7-dienone 4, followed by the methylation of the intermediate enolate, yielded a single isomer of 7,8-dimethylcyclooct-2-enone (+)-5. Compound (+)-5 was subjected to the second conjugate addition with ent-L(1) giving only one stereoisomer of 2,3,7-trimethylcyclooctanone (+)-6, which was converted to 2,3,7-trimethylcyclooctanol 7. To determine the relative and absolute configurations of these compounds, the (1)H NMR anisotropy method using (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid {(S)-(+)-MalphaNP acid} 1 was applied.

Synthesis of enantiopure 2-aryl-2-methoxypropionic acids and determination of their absolute configurations by X-ray crystallography.

Racemic 2-aryl-2-methoxypropionic acids were enantioresolved by the use of (S)-(-)-phenylalaninol 4. For instance, racemic 2-methoxy-2-phenylpropionic acid (+/-)-7 was condensed with phenylalaninol (S)-(-)-4 yielding a diastereomeric mixture of amides, which was easily separated by HPLC on silica gel affording the first-eluted amide (-)-13a and the second-eluted amide (+)-13b: alpha = 3.19, Rs = 3.

New route to enantiopure MalphaNP acid, a powerful resolution and chiral 1H NMR anisotropy reagent.

MalphaNP acid (+/-)-1, 2-methoxy-2-(1-naphthyl)propionic acid, was enantioresolved by the use of phenylalaninol (S)-(-)-4; a diastereomeric mixture of amides formed from acid (+/-)-1 and amine (S)-(-)-4 was easily separated by fractional recrystallization and/or HPLC on silica gel, yielding amides (R;S)-(-)-5a and (S;S)-(+)-5b. Their absolute configurations were determined by X-ray crystallography by reference to the S configuration of the phenylalaninol moiety. Amide (R;S)-(-)-5a was converted to oxazoline (R;S)-(+)-8a, from which enantiopure MalphaNP acid (R)-(-)-1 was recovered.

Synthesis of enantiopure phthalides including 3-butylphthalide, a fragrance component of celery oil, and determination of their absolute configurations.

Enantiopure phthalides 2 and 5-8 were synthesized via enantioresolution of the corresponding alcohols with a chiral auxiliary of camphorsultam dichlorophthalic acid, (1S,2R,4R)-(-)-CSDP acid 3, followed by solvolysis with KOH in MeOH and the catalytic oxidation of chiral glycols with iridium complex 28. The absolute configurations of phthalides 2 and 5-8 were determined by applying the (1)H-NMR anisotropy method of MalphaNP acid (4), 2-methoxy-2-(1-naphthyl)propionic acid, to the chiral synthetic precursory alcohols. In the case of 3-phenylphthalide (R)-(-)-7, the absolute configuration determined by the (1)H-NMR anisotropy method using MalphaNP acid 4 agreed with that by the X-ray crystallographic method.

Phosphasilaferracyclopropane: an activator of small molecules having polarized single, double, and aromatic unsaturated bonds.

Irradiation of Cp*(CO)2FeSiMe2PPh2 resulted in the formation of phosphasilaferracyclopropane 2, which readily reacted with small organic molecules with polarized bonds to yield 3-5.

Enantioresolution of fluorinated diphenylmethanols and determination of their absolute configurations by X-Ray crystallographic and 1H NMR anisotropy methods.

Various fluorinated diphenylmethanols were enantioresolved by the methods of chiral camphorsultam-dichlorophthalic acid (CSDP acid) and/or 2-methoxy-2-(1-naphthyl)propionic acid (MalphaNP acid) yielding enantiopure alcohols. Their absolute configurations were unambiguously determined by X-ray crystallography of CSDP esters and/or by the (1)H NMR anisotropy method of MalphaNP esters for the first time.