Enhancing the sequence coverage of nanodiamond-extracted early secretory proteins from the complex.

The unambiguous identification of protein species requires high sequence coverage. In this study, we successfully improved the sequence coverage of early secretory 10 kDa cell filtrate protein (CFP-10) and 6 kDa early secretory antigenic target (ESAT-6) proteins from the complex (MTC) in broth culture media with the use of the 4-chloro-α-cyanocinnamic acid (Cl-CCA) matrix. Conventional matrices, α-cyano-hydroxy-cinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB), were also used for comparison.

Real-Time Monitoring of the Evaporation and Fission of Electrospray-Ionized Polystyrene Beads and Bacterial Pellets at Elevated Temperatures.

This study uses real-time monitoring, at microsecond time scales, with a charge-sensing particle detector to investigate the evaporation and fission processes of methanol/micrometer-sized polystyrene beads (PS beads) droplets and bacterial particles droplets generated via electrospray ionization (ESI) under elevated temperatures. By incrementally raising capillary temperatures, the solvent, such as methanol on 0.75 μm PS beads, experiences partial evaporation.

Fluorescent nanodiamond immunosensors for clinical diagnostics of tuberculosis.

Fluorescent nanodiamonds (FNDs) are carbon nanoparticles containing a dense ensemble of nitrogen-vacancy defects as color centers. These centers have exceptional photostability and unique quantum properties, making them useful for ultrasensitive biosensing applications. This work employed FNDs conjugated with antibodies as magneto-optical immunosensors for tuberculosis (TB) diagnostics using competitive spin-enhanced lateral flow immunoassay (SELFIA).

Development of a linear ion trap mass spectrometer capable of analyzing megadalton MALDI ions.

Detecting megadalton matrix-assisted laser desorption/ionization (MALDI) ions in an ion trap mass spectrometer is a technical challenge. In this study, megadalton protein and polymer ions were successfully measured by MALDI linear ion trap mass spectrometer (LIT-MS) for the first time. The LIT-MS is comprised of a Thermo linear ion trap mass analyzer and a highly sensitive charge-sensing particle detector (CSPD).

Rapid Quantification of Polyhydroxybutyrate Polymer from Single Bacterial Cells with Mass Spectrometry.

Polyhydroxyalkanoate (PHA) is one of the biocompatible and biodegradable plastics that can be produced and accumulated as granules inside microorganisms. In this study, a new approach to rapidly quantify a short-chain-length PHA, polyhydroxybutyrate (PHB), produced from genetically engineered containing is presented. The mass of each bacterial cell was measured using a laser-induced radio frequency (rf) plasma charge detection quadrupole ion trap mass spectrometer (LIRFP CD QIT-MS), and then, the PHB contents were determined by calculating the change in cellular mass.

Comparison of Postoperative Acute Kidney Injury Between Laparoscopic and Laparotomy Procedures in Elderly Patients Undergoing Colorectal Surgery.

Objectives: Postoperative acute kidney injury (AKI) has an unfavorable impact on both short-term and long-term outcomes. The aim of this retrospective study was to compare the incidence of postoperative AKI between laparoscopic and laparotomy procedures in elderly patients undergoing colorectal surgery.

Methods: Medical records of elderly (65 y and older) patients who underwent colorectal cancer surgery between May 2016 and July 2018 at our tertiary hospital were reviewed.

Ionization of Submicrometer-Sized Particles by Laser-Induced Radiofrequency Plasma for Mass Spectrometric Analysis.

A laser-induced rf plasma (LIRFP) ion source was developed to ionize submicrometer-sized particles for the first time. The LIRFP ion source can increase the charge of those particles to several thousand charges via charge exchange reactions so that those particles can be trapped and analyzed with a charge detection quadrupole ion trap-mass spectrometer (CD QIT-MS). Different reagent gases for charge exchange reaction were investigated, viz.

Forced dried droplet method for MALDI sample preparation.

A forced dried droplet method (FDD) is developed to overcome the drawbacks of the conventional dried-droplet (DD) method for matrix assisted laser desorption/ionization (MALDI) sample preparation. The crystals produced by the DD method are heterogeneous and irregularly distributed, and thus many methods have tried to solve the problems. However, most of them spend more time or need additional instruments to generate homogeneous microcrystals.

Direct detection of carbapenemase-associated proteins of Acinetobacter baumannii using nanodiamonds coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The appearance and spread of carbapenem-resistant Acinetobacter baumannii (CRAB) pose a challenge for optimization of antibiotic therapies and outbreak preventions. The carbapenemase production can be detected through culture-based methods (e.g.

Myocardial injury in elderly patients after abdominal surgery.

Background: The development of sensitive myocardial-specific cardiac biomarkers allows for detection of very small amounts of myocardial injury or necrosis. Myocardial injury (MI) as a prelude of the serious perioperative complication myocardial infarction, should be paid more attention, especially in elderly susceptible patients. Myocardial injury after abdominal surgery in elderly patients has not been described yet.

High Mass Ion Detection with Charge Detector Coupled to Rectilinear Ion Trap Mass Spectrometer.

Conventional linear ion trap mass analyzers (LIT-MS) provide high ion capacity and show their MS ability; however, the detection of high mass ions is still challenging because LIT-MS with secondary electron detectors (SED) cannot detect high mass ions. To detect high mass ions, we coupled a charge detector (CD) to a rectilinear ion trap mass spectrometer (RIT-MS). Immunoglobulin G ions (m/z ~150,000) are measured successfully with controlled ion kinetic energy.

Development of Visible-Wavelength MALDI Cell Mass Spectrometry for High-Efficiency Single-Cell Analysis.

Mass is a fundamental physical property of an individual cell, from which is revealed the cell growth, cycle, and activity. Taking advantage of cell mass spectrometry (CMS), accurate mass measurement of a charged single cell has been achieved. However, with the increasing demand for high-efficiency single-cell analysis in biology, the limited throughput and inefficient cell desorption/ionization of the CMS inevitably become important issues.

Changes in the Bispectral Index in Response to Loss of Consciousness and No Somatic Movement to Nociceptive Stimuli in Elderly Patients.

Background: Bispectral index (BIS) is considered very useful to guide anesthesia care in elderly patients, but its use is controversial for the evaluation of the adequacy of analgesia. This study compared the BIS changes in response to loss of consciousness (LOC) and loss of somatic response (LOS) to nociceptive stimuli between elderly and young patients receiving intravenous target-controlled infusion (TCI) of propofol and remifentanil.

Methods: This study was performed on 52 elderly patients (aged 65-78 years) and 52 young patients (aged 25-58 years), American Society of Anesthesiologists physical status I or II.

Effects of transcutaneous electrical acupoint stimulation at different frequencies on perioperative anesthetic dosage, recovery, complications, and prognosis in video-assisted thoracic surgical lobectomy: a randomized, double-blinded, placebo-controlled trial.

Background: Transcutaneous electrical acupoint stimulation (TEAS), a non-invasive and non-pharmacological adjunctive intervention for perioperative analgesia, may also reduce the incidence of postoperative pulmonary complications. The effect of TEAS on video-assisted thoracic surgical (VATS) patients is still unknown, however. The purpose of this study was to investigate the effects of TEAS of different frequency on perioperative anesthetic dosage, recovery, complications, and prognosis for patients undergoing VATS lobectomy.

Validation of nanodiamond-extracted CFP-10 antigen as a biomarker in clinical isolates of Mycobacterium tuberculosis complex in broth culture media.

With detonation nanodiamonds (DNDs) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS), we previously identified early secreted cell filtrate protein 10 (CFP-10) as a candidate Mycobacterium tuberculosis complex (MTC) biomarker. The performance of the CFP-10 biomarker was initially evaluated in relatively small mycobacterial samples (n = 42 samples) in our previous study. In this study, we conducted DND MALDI-TOF MS experiments to investigate the specificity and sensitivity of the MTC biomarker with 312 MTC and 52 nontuberculous mycobacteria (NTM) clinical samples.

Measuring masses of large biomolecules and bioparticles using mass spectrometric techniques.

Large biomolecules and bioparticles play a vital role in biology, chemistry, biomedical science and physics. Mass is a critical parameter for the characterization of large biomolecules and bioparticles. To achieve mass analysis, choosing a suitable ion source is the first step and the instruments for detecting ions, mass analyzers and detectors should also be considered.

Quantitative assessment of protein adsorption on microparticles with particle mass spectrometry.

In this paper, particle mass spectrometry (PMS), which consists of an aerodynamic desorption/ionization (AD) source, a quadrupole ion trap (QIT) mass analyzer, and a charge detector, was exploited to characterize the protein adsorption on microparticles based on the mass variations of microparticles before and after protein adsorption. This method is simple and has low sample cost. Importantly, its mass resolution is good enough to distinguish the microparticles with and without protein.

Game-theory-based search engine to automate the mass assignment in complex native electrospray mass spectra.

Electrospray ionization coupled to native mass spectrometry (MS) has evolved into an important tool in structural biology to decipher the composition of protein complexes. However, the mass analysis of heterogeneous protein assemblies is hampered because of their overlapping charge state distributions, fine structure, and peak broadening. To facilitate the mass analysis, it is of importance to automate preprocessing raw mass spectra, assigning ion series to peaks and deciphering the subunit compositions.

Ambient aerodynamic desorption/ionization method for microparticle mass measurement.

An ambient desorption/ionization method, named aerodynamic desorption (AD), was proposed for the in situ rapid mass measurement of microparticles. The AD method exploited the discontinuous atmospheric pressure interface (DAPI) to generate a pulsed airflow, which was used to desorb the microparticles under atmospheric pressure. Various microparticles, e.

Wavelet-based method for time-domain noise analysis and reduction in a frequency-scan ion trap mass spectrometer.

We adopt an orthogonal wavelet packet decomposition (OWPD) filtering approach to cancel harmonic interference noises arising from an AC power source in time domain and remove the resulting rf voltage interference noise from the mass spectra acquired by using a charge detection frequency-scan quadrupole ion trap mass spectrometer. With the use of a phase lock resampling technique, the transform coefficients of the rf interference in signals become a constant, exhibiting a shift of the baseline in different rf phases. The rf interference is therefore removable by shifting the baselines back to zero in OWPD coefficients.

Detonation nanodiamonds for rapid detection of clinical isolates of Mycobacterium tuberculosis complex in broth culture media.

Routinely used molecular diagnostic methods for mycobacterium identification are expensive and time-consuming. To tackle this problem, we develop a method to streamline identification of Mycobacterium tuberculosis complex (MTBC) in broth culture media by using detonation nanodiamonds (DNDs) as a platform to effectively capture the antigen secreted by MTBC which is cultured in BACTEC MGIT 960, followed by the analysis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The 5 nm DNDs can capture the MTBC secretory antigen without albumin interference.

The development of charge detection-quadrupole ion trap mass spectrometry driven by rectangular and triangular waves.

In this article, the charge detection quadrupole mass spectrometry (CD-ITMS) driven by rectangular and triangular waveforms (rect-CD-ITMS and tri-CD-ITMS) was developed for the characterization of microparticles. Since the frequency scan of rectangular and triangular waveform could be realized easier than that of sinusoidal waveform, this research intends to provide simpler operation modes for CD-ITMS. In order to demonstrate the feasibility of rect-CD-ITMS and tri-CD-ITMS, the discharge onset voltage, ejection point of analyzed particles, and the achieved mass resolution were analyzed and compared with the case in conventional sinusoidal CD-ITMS (sin-CD-ITMS).

Characterization of column packing materials in high-performance liquid chromatography by charge-detection quadrupole ion trap mass spectrometry.

This article reports an application of charge-detection quadrupole ion trap mass spectrometry (CD-ITMS) to characterize the column packing materials in high-performance liquid chromatography (HPLC). Both the mean mass and the mass distribution of the packing materials are obtained and used to calculate the specific surface area of unbonded silica, the carbon load of the bonded silica, and their particle size distributions. The obtained specific surface areas and carbon loads are consistent with those measured independently by nitrogen sorption and elemental analysis respectively, whereas the derived size distributions show better resolution than that measured by a laser particle size analyzer.

Potential distribution and transmission characteristics in a curved quadrupole ion guide.

The potential distribution in the curved quadrupole is exactly characterized by the Laplace equation, and an approximate solution to the Laplace equation is calculated. We represent the Laplace equation under the coordinates named minimal rotation frame (MRF) and derive an expression on the hexapole and octopole superposition. Our conclusion is in agreement with the results by the numerical (SIMION) method.