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QM/MM study of the stereospecific proton exchange of glutathiohydroxyacetone by glyoxalase I

We have performed quantum mechanics (QM), molecular mechanics (MM) and hybrid QM/MM calculations to study the stereospecific proton exchange of glutathiohydroxyacetone (HOC-SG) by glyoxalase I (GlxI). We did the QM/MM calculations with a large QM system (246 atoms) to investigate the proton-exchange mechanism. Moreover, single-point big-QM energies with 1303 atoms in the big QM system and 22,412 a

Quantum Mechanics/Molecular Mechanics Study of the Reaction Mechanism of Glyoxalase I

Glyoxalase I (GlxI) is a member of the glyoxalasesystem, which is important in cell detoxification and convertshemithioacetals of methylglyoxal (a cytotoxic byproduct of sugarmetabolism that may react with DNA or proteins and introducenucleic acid strand breaks, elevated mutation frequencies, andstructural or functional changes of the proteins) and glutathioneinto D-lactate. GlxI accepts both the

Water structure in solution and crystal molecular dynamics simulations compared to protein crystal structures

The function of proteins is influenced not only by the atomic structure but also by the detailed structure of the solvent surrounding it. Computational studies of protein structure also critically depend on the water structure around the protein. Herein we compare the water structure obtained from molecular dynamics (MD) simulations of galectin-3 in complex with two ligands to crystallographic wat

What Is the Structure of the E4 Intermediate in Nitrogenase?

Nitrogenase is the only enzyme that can cleave the strong triple bond inN2. The active site contains a complicated MoFe7S9C cluster. It is believed that itneeds to accept four protons and electrons, forming the E4 state, before it can bind N2.However, there is no consensus on the atomic structure of the E4 state. Experimentalstudies indicate that it should contain two hydride ions bridging two pai

Putative reaction mechanism of nitrogenase after dissociation of a sulfide ligand

We have investigated the implications of the recent crystallographic findings that the m2-bridging S2B sulfide ligand may reversibly dissociate from the active-site FeMo cluster of nitrogenase. We show with combined quantum mechanical and molecular mechanical (QM/MM) calculations that once S2B has dis- sociated, N2 may bind in that position and can be protonated to two NH3 groups by thermodynamica

A Detailed Analysis of Internal Resistance of a PEFC Comparing High and Low Humidification of the Reactant Gases

Polymer electrolyte fuel cells (PEFCs) have shown a great potential to be used in several applications, e.g., portable, mobile and stationary systems. Each of the mentioned applications demands from PEFCs different operating conditions to perform in the best possible manner. Knowing in detail the behavior of their internal components will help to improve the mechanical and thermal properties of th

Using augmented reality to train flow patterns for pilot students - An explorative study

Today, just as in the early days of flying, much emphasis is put on the pilot student’s flight training before flying a real commercial aircraft. In the early stages of a pilot student’s education, they must, for example, learn different operating procedures known as flow patterns using very basic tools, such as exhaustive manuals and a so-called paper tiger. In this paper, we present a first desi

Calculating the Starting Age for Screening in Relatives of Patients With Colorectal Cancer Based on Data From Large Nationwide Data Sets

BACKGROUND & AIMS: Although colorectal cancer (CRC) screening guidelines acknowledge the need for earlier screening for high-risk individuals, such as those with family history of CRC, there is limited information on how many years earlier these high-risk individuals should be screened; current practice is based on weak evidence. We aimed to provide risk-adapted recommendations on the starting

Risk of invasive prostate cancer and prostate cancer death in relatives of patients with prostatic borderline or in situ neoplasia : A nationwide cohort study

BACKGROUND: The question of whether having a family history of prostatic borderline or in situ neoplasia (PBISN) is associated with an increased risk of invasive prostate cancer (PCa) or death from PCa remains unanswered. The objective of the current study was to provide an evidence-based risk estimation for the relatives of patients with PBISN.METHODS: Nationwide Swedish family cancer data sets w

AGRONOMIC EDUCATION AT A CROSSROAD: PROVIDING SKILL SETS OR DEVELOPING MINDSETS?

Globally, agrifoodsystems are in constant evolution. In such a context, agronomists have the critical task to act as change agents, enabling agricultural innovation and facilitating the transition towards sustainability. Hence, agronomists should develop a new professional mindset that goes beyond the prescribed roles and fixed duties of a bounded professional. However, it is questionable whether

Adjunct High Frequency Transcutaneous Electric Stimulation (TENS) for Postoperative Pain Management during Weaning from Epidural Analgesia Following Colon Surgery : Results from a Controlled Pilot Study

The potential benefit of nonpharmacological adjunctive therapy is not well-studied following major abdominal surgery. The aim of the present study was to investigate transcutaneous electrical nerve stimulation (TENS) as a complementary nonpharmacological analgesia intervention during weaning from epidural analgesia (EDA) after open lower abdominal surgery. Patients were randomized to TENS and sham

Agreement between frontal and occipital regional cerebral oxygen saturation in infants during surgery and general anesthesia an observational study

Background: Advances in perioperative pediatric care have resulted in an increased number of procedures requiring anesthesia. During anesthesia and surgery, the patient is subjected to factors that affect the circulatory homeostasis, which can influence oxygenation of the brain. Near-infrared spectroscopy (NIRS) is an easy applicable noninvasive method for monitoring of regional tissue oxygenation