Absolute quantification of nicotinamide mononucleotide in biological samples by double isotope-mediated liquid chromatography-tandem mass spectrometry (dimeLC-MS/MS).

Nicotinamide adenine dinucleotide (NAD) is an essential metabolite for fundamental biological phenomena, including aging. Nicotinamide mononucleotide (NMN) is a key NAD intermediate that has been extensively tested as an effective NAD-boosting compound in mice and humans. However, the accurate measurement of NMN in biological samples has long been a challenge in the field.

Solid-phase microextraction- probe electrospray ionization devices for screening and quantitating drugs of abuse in small amounts of biofluids.

Probe electrospray ionization (PESI) is an ambient ionization mass spectrometry technique (AIMS) that is primarily used in qualitative studies, though researchers have recently combined it with sample preparation for the quantitative analysis of various analytes in biological matrices. This study presents a method that integrates solid-phase microextraction with PESI for direct coupling to a triple quadrupole mass spectrometer, and examines its ability to quantitate drugs of abuse. Intra- and inter-probe reproducibility experiments were conducted to assess the stability and reproducibility of the extraction-phase-coated PESI probes (coating length: 2 mm; coating thickness: 6.

Multivariate approach to on-line supercritical fluid extraction - supercritical fluid chromatography - mass spectrometry method development.

Coupling supercritical fluid extraction (SFE) on-line with supercritical fluid chromatography (SFC) - tandem mass spectrometry (MS/MS) provides a single platform for efficient extraction, separation, and detection in a chemical analysis. SFE-SFC-MS/MS requires consideration of many extraction and chromatographic variables to not only provide the most efficient extraction, but also to analytically transfer the extracted analytes to the column for separation. There is a fundamental lack of understanding of how the variables in SFE affect those in SFC.

Photoinduced Ligand Release from a Silicon Phthalocyanine Dye Conjugated with Monoclonal Antibodies: A Mechanism of Cancer Cell Cytotoxicity after Near-Infrared Photoimmunotherapy.

Photochemical reactions can dramatically alter physical characteristics of reacted molecules. In this study, we demonstrate that near-infrared (NIR) light induces an axial ligand-releasing reaction, which dramatically alters hydrophilicity of a silicon phthalocyanine derivative (IR700) dye leading to a change in the shape of the conjugate and its propensity to aggregate in aqueous solution. This photochemical reaction is proposed as a major mechanism of cell death induced by NIR photoimmunotherapy (NIR-PIT), which was recently developed as a molecularly targeted cancer therapy.

On-line supercritical fluid extraction-supercritical fluid chromatography-mass spectrometry of polycyclic aromatic hydrocarbons in soil.

On-line supercritical fluid extraction - supercritical fluid chromatography - mass spectrometry (SFE-SFC-MS) has been applied for the determination of polycyclic aromatic hydrocarbons (PAHs) in soil. The purpose of this study was to develop and validate the first on-line SFE-SFC-MS method for the quantification of PAHs in various types of soil. By coupling the sample extraction on-line with chromatography and detection, sample preparation is minimized, diminishing sample loss and contamination, and significantly decreasing the required extraction time.

[Case of Rh (-) patient's right lobectomy of the liver with massive hemorrhage evading allogeneic blood transfusion by hemodilutional autologous blood transfusion].

A 44-year-old man (ASA-PS 1) underwent right lobectomy of the liver under total intravenous anesthesia with propofol, remifentanil, ketamine and rocuronium. In order to evade allogeneic blood transfusion, 1,200 g of the patient's blood was taken and hemodilution was induced for autologous blood transfusion (HAT) after the induction of anesthesia. As intraoperative blood loss amounted to about 4,000 g, Hb level decreased from 13.

Atf1 is a target of the mitogen-activated protein kinase Pmk1 and regulates cell integrity in fission yeast.

In fission yeast, knockout of the calcineurin gene resulted in hypersensitivity to Cl(-), and the overexpression of pmp1(+) encoding a dual-specificity phosphatase for Pmk1 mitogen-activated protein kinase (MAPK) or the knockout of the components of the Pmk1 pathway complemented the Cl(-) hypersensitivity of calcineurin deletion. Here, we showed that the overexpression of ptc1(+) and ptc3(+), both encoding type 2C protein phosphatase (PP2C), previously known to inactivate the Wis1-Spc1-Atf1 stress-activated MAPK signaling pathway, suppressed the Cl(-) hypersensitivity of calcineurin deletion. We also demonstrated that the mRNA levels of these two PP2Cs and pyp2(+), another negative regulator of Spc1, are dependent on Pmk1.

[Overview of cardiac contrast examination using 64-row multislice CT].

ECG-gated multislice CT(MSCT)now supports not only morphological but also functional diagnosis. In order to improve accuracy in the functional analysis of cardiac motion, it is important to depict the endocardial and epicardial contours. The present study was conducted to evaluate a method in which contrast medium and physiological saline solution(saline)are injected simultaneously, and the iodinated contrast medium concentration is varied in a stepwise manner(multi-stage injection)or continuously(cross injection).

Giant macrocycles composed of thiophene, acetylene, and ethylene building blocks.

Fully conjugated giant macrocyclic oligothiophenes with 60pi, 90pi,120pi, 150pi, and 180pi frames (1, 2, 3, 4 and 5) have been designed, and their butyl-substituted derivatives (1a, 2a, 3a, 4a, and 5a) have been synthesized using modified Sonogashira and McMurry coupling reactions as key steps. The 60-180pi systems 1-5 are circular with 1.8-6 nm inner cavities and 3.

Fully automated micro- and nanoscale one- or two-dimensional high-performance liquid chromatography system for liquid chromatography-mass spectrometry compatible with non-volatile salts for ion exchange chromatography.

A one- or two-dimensional high performance liquid chromatography system for electrospray ionization mass spectrometers has been developed that is optimized for ion exchange and reversed phase separations. A unique and simple valve configuration permits the use of a variety of non-volatile salts; ammonium sulfate was used in an example of strong cation exchange separations. The system was designed and evaluated for both micro- and nanoflow chromatography.