Inhibition mechanism of testis-expressed gene 14 (TEX14) in cytokinetic abscission: Well-tempered metadynamics simulation studies.

Cytokinesis requires a apoptosis-linked gene 2 interacting protein X (ALIX) and a 55 kDa midbody centrosomal protein (CEP55) to activate the cell abscission in somatic cells. However, in germ cells, CEP55 forms intercellular bridges with testis-expressed gene 14 (TEX14), which blocks the cell abscission. These intercellular bridges play important roles in the synchronization of the germ cells and facilitate the coordinated passage of organelles and molecules between germ cells.

Antiobesity Effect of Prebiotic Polyphenol-Rich Grape Seed Flour Supplemented with Probiotic Kefir-Derived Lactic Acid Bacteria.

The interaction between prebiotics and probiotics may exert synergistic health benefits. This study investigated the combined effects of polyphenol-rich wine grape seed flour (GSF), a prebiotic, and lactic acid bacteria (LAB) derived from kefir, a probiotic, on obesity-related metabolic disease in high-fat diet (HFD) induced obese (DIO) mice. DIO mice were fed with HFD with 6% microcrystalline cellulose (CON) or HFD supplemented with GSF (5% or 10% GSF), HFD with LAB orally administrated (LAB), or HFD with a combination of GSF and LAB orally administrated (GSF+LAB) for 9 weeks.

Ternary Organic Photovoltaics Prepared by Sequential Deposition of Single Donor and Binary Acceptors.

Binary organic photovoltaics (OPVs) fabricated by single-step (SS) deposition of a binary blend of polymer (or small molecule) donor and fullerene acceptor (SS binary OPV) are widely utilized. To improve the OPV performance, SS ternary OPVs utilizing a ternary blend consisting of two (or one) electron donor(s) and one (or two) electron acceptor(s) have been studied. SS ternary OPVs require more sensitive and complex optimization processes to optimize bulk heterojunctions with bicontinuous nanoscale phase separation of the donor and acceptor.

A motor neuron strategy to save time and energy in neurodegeneration: adaptive protein stoichiometry.

Neurofilament proteins (Nf) are a biomarker of disease progression in amyotrophic lateral sclerosis (ALS). This study investigated whether there are major differences in expression from in vivo measurements of neurofilament isoforms, from the light chain, NfL (68 kDa), compared with larger proteins, the medium chain (NfM, 150 kDa) and the heavy (NfH, 200-210 kDa) chains in ALS patients and healthy controls. New immunological methods were combined with Nf subunit stoichiometry calculations and Monte Carlo simulations of a coarse-grained Nf brush model.

Distinct Fragmentation Pathways of Anticancer Drugs Induced by Charge-Carrying Cations in the Gas Phase.

With the growth of the pharmaceutical industry, structural elucidation of drugs and derivatives using tandem mass spectrometry (MS) has become essential for drug development and pharmacokinetics studies because of its high sensitivity and low sample requirement. Thus, research seeking to understand fundamental relationships between fragmentation patterns and precursor ion structures in the gas phase has gained attention. In this study, we investigate the fragmentation of the widely used anticancer drugs, doxorubicin (DOX), vinblastine (VBL), and vinorelbine (VRL), complexed by a singly charged proton or alkali metal ion (Li, Na, K) in the gas phase.

Supercritical fluid chromatography coupled with in-source atmospheric pressure ionization hydrogen/deuterium exchange mass spectrometry for compound speciation.

An experimental setup for the speciation of compounds by hydrogen/deuterium exchange (HDX) with atmospheric pressure ionization while performing chromatographic separation is presented. The proposed experimental setup combines the high performance supercritical fluid chromatography (SFC) system that can be readily used as an inlet for mass spectrometry (MS) and atmospheric pressure photo ionization (APPI) or atmospheric pressure chemical ionization (APCI) HDX. This combination overcomes the limitation of an approach using conventional liquid chromatography (LC) by minimizing the amount of deuterium solvents used for separation.

Structural Characterization of Anticancer Drug Paclitaxel and Its Metabolites Using Ion Mobility Mass Spectrometry and Tandem Mass Spectrometry.

Paclitaxel (PTX) is a popular anticancer drug used in the treatment of various types of cancers. PTX is metabolized in the human liver by cytochrome P450 to two structural isomers, 3′-p-hydroxypaclitaxel (3p-OHP) and 6α-hydroxypaclitaxel (6α-OHP). Analyzing PTX and its two metabolites, 3p-OHP and 6α-OHP, is crucial for understanding general pharmacokinetics, drug activity, and drug resistance.

Optimization and Application of APCI Hydrogen-Deuterium Exchange Mass Spectrometry (HDX MS) for the Speciation of Nitrogen Compounds.

A systematic study was performed to investigate the utility of atmospheric pressure chemical ionization hydrogen-deuterium exchange mass spectrometry (APCI HDX MS) to identify the structures of nitrogen-containing aromatic compounds. First, experiments were performed to determine the optimized experimental conditions, with dichloromethane and CH(3)OD found to be good cosolvents for APCI HDX. In addition, a positive correlation between the heated capillary temperature and the observed HDX signal was observed, and it was suggested that the HDX reaction occurred when molecules were contained in the solvent cluster.

Developments in FT-ICR MS instrumentation, ionization techniques, and data interpretation methods for petroleomics.

Because of the increasing importance of heavy and unconventional crude oil as an energy source, there is a growing need for petroleomics: the pursuit of more complete and detailed knowledge of the chemical compositions of crude oil. Crude oil has an extremely complex nature; hence, techniques with ultra-high resolving capabilities, such as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), are necessary. FT-ICR MS has been successfully applied to the study of heavy and unconventional crude oils such as bitumen and shale oil.

Elucidating molecular structures of nonalkylated and short-chain alkyl (n < 5, (CH₂)n) aromatic compounds in crude oils by a combination of ion mobility and ultrahigh-resolution mass spectrometries and theoretical collisional cross-section calculations.

Ultrahigh-resolution mass spectrometry has allowed the determination of elemental formulas of the compounds comprising crude oils. However, elucidating molecular structures remains an analytical challenge. Herein, we propose and demonstrate an approach combining ion mobility mass spectrometry (IM-MS), ultrahigh-resolution mass spectrometry, and theoretical collisional cross-section (CCS) calculations to determine the molecular structures of aromatic compounds found in crude oils.

The comparison of naturally weathered oil and artificially photo-degraded oil at the molecular level by a combination of SARA fractionation and FT-ICR MS.

Two sets of oil samples, one obtained from different weathering stages of the M/V Hebei Spirit oil spill site and the other prepared by an in vitro photo-degradation experiment, were analyzed and compared at the molecular level by atmospheric pressure photo-ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). For a more detailed comparison at the molecular level, the oil samples were separated into saturate, aromatic, resin, and asphaltene (SARA) fractions before MS analysis. Gravimetric analysis of the SARA fractions revealed a decreased weight percentage of the aromatic fraction and an increased resin fraction in both sets of samples.

Application of phase correction to improve the interpretation of crude oil spectra obtained using 7 T Fourier transform ion cyclotron resonance mass spectrometry.

In this study, a phase-correction technique was applied to the study of crude oil spectra obtained using a 7 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). 7 T FT-ICR MS had not been widely used for oil analysis due to the lower resolving power compared with high field FT-ICR MS. For low field instruments, usage of data that has not been phase-corrected results in an inability to resolve critical mass splits of C3 and SH4 (3.

Application of atmospheric pressure photo ionization hydrogen/deuterium exchange high-resolution mass spectrometry for the molecular level speciation of nitrogen compounds in heavy crude oils.

We report here for the first time the application of atmospheric pressure photo ionization hydrogen/deuterium exchange (APPI HDX) coupled to high-resolution mass spectrometry for molecular level speciation of nitrogen containing compounds in crude oils. The speciation was done based on different combinations of ions produced from nitrogen containing compounds with various functional groups. To prove the concept, 20 nitrogen containing standard compounds were analyzed.

Hepatic and splenic infarction and bowel ischemia following endoscopic ultrasound-guided celiac plexus neurolysis.

Endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) is a well-established intervention to palliate malignant pain. We report a patient who developed hepatic and splenic infarction and bowel ischemia following EUS-CPN. A 69-year-old man with known lung cancer and pancreatic metastasis was transferred for debilitating, significant epigastric pain for several months.

Characterization of crude oils at the molecular level by use of laser desorption ionization Fourier-transform ion cyclotron resonance mass spectrometry.

In this study, laser desorption ionization (LDI) coupled to Fourier-transform ion cyclotron resonance mass spectrometry (FTICR MS) was applied to study crude oils at the molecular level. Molecular ions were the major type of ion detected by (+) mode, and deprotonated and radical anions were the major ions observed by (-) mode LDI FTICR MS. N(1) and hydrocarbon classes were dominant in the class distribution plots obtained by (+) LDI FTICR MS, but other heteroatom classes, including O(x) and S(1), were abundant in plots obtained by (-) LDI FTICR MS.

Planar limit-assisted structural interpretation of saturates/aromatics/resins/asphaltenes fractionated crude oil compounds observed by Fourier transform ion cyclotron resonance mass spectrometry.

Planar limits, defined as lines generated by connecting maximum double-bond equivalence (DBE) values at given carbon numbers, are proposed as a means of predicting and understanding the molecular structure of compounds in crude oil. The slopes and y-intercepts of the lines are determined by the DBE/carbon number ratios of functional groups defining the planar limits. For example, the planar limit generated by a serial addition of saturated cyclic rings has a slope of 0.