Unravelling the Structure of One-Electron Oxidation Products of Model Peptide Backbones Containing Methionine by IRMPD Spectroscopy: the Effect of the Neighbouring Groups.

A series of Methionine (Met) derivatives, where either the amino group and/or the carboxylic acid group is blocked by acetyl and/or methyl ester functionalities, has been investigated by Collision Induced Dissociation-tandem mass spectrometry (CID-MS) and Infrared Multiple Photon Dissociation (IRMPD) spectroscopy. The CID-MS experiments were performed using a Fourier-transform ion-cyclotron-resonance (FT-ICR) mass spectrometer equipped with an electrospray ionization (ESI) source. The IRMPD spectra were recorded employing a Paul type ion-trap coupled with the free-electron laser (FEL) FELIX in the fingerprint region from 600 to 2000 cm.

OH Radical-Induced Oxidation in Nucleosides and Nucleotides Unraveled by Tandem Mass Spectrometry and Infrared Multiple Photon Dissociation Spectroscopy.

OH⋅-induced oxidation products of DNA nucleosides and nucleotides have been structurally characterized by collision-induced dissociation tandem mass spectrometry (CID-MS ) and Infrared Multiple Photon Dissociation (IRMPD) spectroscopy. CID-MS results have shown that the addition of one oxygen atom occurs on the nucleobase moiety. The gas-phase geometries of +16 mass increment products of 2'-deoxyadenosine (dA(O)H ), 2'-deoxyadenosine 5'-monophosphate (dAMP(O)H ), 2'-deoxycytidine (dC(O)H ), and 2'-deoxycytidine 5'-monophosphate (dCMP(O)H ) are extensively investigated by IRMPD spectroscopy and quantum-chemical calculations.

Binding Motifs of Carboplatin and Oxaliplatin with Guanine: A Combined MS/MS, IRMPD, and Theoretical Study.

Complexes generated in the gas phase involving the purine nucleobase guanine bound to second and third generation platinum drugs, namely, carboplatin (CarboPt) and oxaliplatin (OxaliPt), were investigated by combining tandem mass spectrometry, collision-induced dissociation (CID), infrared multiple photon dissociation spectroscopy (IRMPD), and density functional theory (DFT) calculations. As the first step, a spectroscopic characterization of the protonated platinum drugs was accomplished. Protonation of both CarboPt and OxaliPt in the gas phase occurs on one of the two carbonyl groups of the cyclobutanedicarboxylate and oxalate ligand, respectively.

Reconstructing the infrared spectrum of a peptide from representative conformers of the full canonical ensemble.

Leucine enkephalin (LeuEnk), a biologically active endogenous opioid pentapeptide, has been under intense investigation because it is small enough to allow efficient use of sophisticated computational methods and large enough to provide insights into low-lying minima of its conformational space. Here, we reproduce and interpret experimental infrared (IR) spectra of this model peptide in gas phase using a combination of replica-exchange molecular dynamics simulations, machine learning, and ab initio calculations. In particular, we evaluate the possibility of averaging representative structural contributions to obtain an accurate computed spectrum that accounts for the corresponding canonical ensemble of the real experimental situation.

Shading Net and Partial Covering Plastic Film Do Not Affect Phenology, Photosynthetic Activity or Fruit Quality Traits of Kensington Pride Mango.

Mango cultivation in a protected environment is becoming widespread in the Mediterranean basin where the species has to face unfavorable weather conditions which do not occur in its native cultivation areas. Besides open-air cultivation, greenhouses-and other protection systems such as shading nets and partial covering of plastic films-have been tested recently. In this study, we focused on assessing the effect of a shading net, and a partially covering plastic film, on the development of "Kensington Pride" mango fruit skin-color, its final quality, and the plants' photosynthetic activity.

Final Products of One-Electron Oxidation of Cyclic Dipeptides Containing Methionine Investigated by IRMPD Spectroscopy: Does the Free Radical Choose the Final Compound?

Reactive oxygen species (ROS) such as hydrogen peroxide (HO) and the hydroxyl radical (OH) have specific functions in biological processes, while their uncontrolled production and reactivity are known to be determining factors in pathophysiology. Methionine (Met) residues act as endogenous antioxidants, when they are oxidized into methionine sulfoxide (MetSO), thus depleting ROS and protecting the protein. We employed tandem mass spectrometry combined with IR multiple photon dissociation spectroscopy to study the oxidation induced by OH radicals produced by γ radiolysis on model cyclic dipeptides c(LMetLMet), c(LMetDMet), and c(GlyMet).

IRMPD Spectroscopy of Bare Monodeprotonated Genistein, an Antioxidant Flavonoid.

Genistein is a naturally occurring polyphenol belonging to the family of flavonoids with estrogenic properties and proven antioxidant, anti-inflammatory, and hormonal effects. Genistein and its derivatives are involved in radical scavenging activity by way of mechanisms based on sequential proton-loss electron transfer. In view of this role, a detailed structural characterization of its bare deprotonated form, [geni-H], generated by electrospray ionization, has been performed by tandem mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy in the 800-1800 cm spectral range.

Clinical characteristics and predictors of death among hospitalized patients infected with SARS-CoV-2 in Sicily, Italy: A retrospective observational study.

Since late December 2019, severe acute respiratory syndrome coronavirus 2 has spread across the world, which resulted in the World Health Organization declaring a global pandemic. Coronavirus disease 2019 (COVID-19) presents a highly variable spectrum with regard to the severity of illness. Most infected individuals exhibit a mild to moderate illness (81%); however, 14% have a serious disease and 5% develop severe acute respiratory distress syndrome (ARDS), requiring intensive care support.

Inter- and Intramolecular Proton Transfer in an Isolated (Cytosine-Guanine)H Pair: Direct Evidence from IRMPD Spectroscopy.

The collision-induced dissociation of the protonated cytosine-guanine pair was studied using tandem mass spectrometry (MS) coupled to infrared multiple photon dissociation spectroscopy with the free electron laser at Orsay (CLIO) to determine the structure of the CH and GH ionic fragments. The results were rationalized with the help of electronic structure calculations at the density functional theory level with the B3LYP/6-311++G(3df,2p) method. Several tautomers of each fragment were identified for the first time, some of which were previously predicted by other authors.

Entecavir resistance in a patient with treatment-naïve HBV: A case report.

Among nucleos(t)ide analogue therapies for hepatitis B virus (HBV) treatment, entecavir (ETV) and tenofovir disoproxil fumarate (TDF)/tenofovir alafenamide are associated with the lowest rate of drug resistance. ETV is a drug requiring at least three substitutions in the reverse transcriptase (RT) domain to develop resistance, which is a rare occasion in treatment-naïve patients. However, pre-existing or acquired single mutations in the RT domain could lead to a virological breakthrough, after viral suppression.

"Diagnosis on the Dock" project: A proactive screening program for diagnosing pulmonary tuberculosis in disembarking refugees and new SEI model.

Objective: From 2011 to 2017, the total number of refugees arriving in Europe, particularly in Italy, climbed dramatically. Our aim was to diagnose pulmonary TB in migrants coming from the African coast using a clinical-based port of arrival (PoA) screening program.

Methods: From 2016 to 2018, migrants coming via the Mediterranean Route were screened for body temperature and the presence of cough directly on the dock: if they were feverish with productive cough, their sputum was examined with NAAT; with a dry cough, they underwent Chest-X-ray (CXR).

Effects of Argon-Based and Nitrogen-Based Modified Atmosphere Packaging Technology on the Quality of Pomegranate ( L. cv. Wonderful) Arils.

Ready-to-eat pomegranate arils are considered a "functional food" for their health benefits and have desirable sensory characteristics, which have caused an increasing interest by the consumers for this product. The preparation process of ready-to-eat fruit products can cause severe injuries and worsen their quality and shelf life significantly. Modified atmosphere packaging (MAP) has been used broadly in the last years to maintain the quality of processed fruits and showed optimal results, in spite of the possible problems caused by the depletion of O and corresponding accumulation of CO in the package.

Molecular Properties of Bare and Microhydrated Vitamin B5-Calcium Complexes.

Pantothenic acid, also called vitamin B5, is an essential nutrient involved in several metabolic pathways. It shows a characteristic preference for interacting with Ca(II) ions, which are abundant in the extracellular media and act as secondary mediators in the activation of numerous biological functions. The bare deprotonated form of pantothenic acid, [panto-H], its complex with Ca(II) ion, [Ca(panto-H)], and singly charged micro-hydrated calcium pantothenate [Ca(panto-H)(HO)] adduct have been obtained in the gas phase by electrospray ionization and assayed by mass spectrometry and IR multiple photon dissociation spectroscopy in the fingerprint spectral range.

IRMPD spectroscopy and quantum chemistry calculations on mono- and bi-metallic complexes of acetylacetonate ligands with aluminum, iron, and ruthenium ions.

Metal-ligand cluster ions are structurally characterized by means of gas-phase infrared multiple photon dissociation spectroscopy. The mass-selected complexes consist of one or two metal cations M (M = Al, Fe, or Ru) and two to five anionic bidentate acetylacetonate ligands. Experimental IR spectra are compared with different density functional theory calculations, namely, PBE/TZVP, B3LYP/6-31G, and M06/6-31+G.

Binding Motifs in the Naked Complexes of Target Amino Acids with an Excerpt of Antitumor Active Biomolecule: An Ion Vibrational Spectroscopy Assay.

The structures of proton-bound complexes of 5,7-dimethoxy-4H-chromen-4-one (1) and basic amino acids (AAs), namely, histidine (His) and lysine (Lys), have been examined by means of mass spectrometry coupled with IR ion spectroscopy and quantum chemical calculations. This selection of systems is based on the fact that 1 represents a portion of glabrescione B, a natural small molecule of promising antitumor activity, while His and Lys are protein residues lining the cavity of the alleged receptor binding site. These species are thus a model of the bioactive adduct, although clearly the isolated state of the present study bears little resemblance to the complex biological environment.

Revision of the Recent Alvania scabra (Philippi, 1844) complex (Mollusca, Gastropoda, Rissoidae) from the Mediterranean Sea with the description of a new species.

Herein we revise several Recent Mediterranean species of the rissoid genus Alvania Risso, 1826: Alvania scabra (Philippi, 1844), Alvania sculptilis (Monterosato, 1877), Alvania sororcula Granata-Grillo, 1877, Alvania lucinae Oberling, 1970, Alvania josefoi Oliver Templado, 2009 and Alvania scuderii Villari, 2017. They represent a rather homogeneous group of morphologically similar species, referred to as the Alvania scabra complex, which includes also some other species from the northeastern Atlantic. We designate a neotype for Rissoa scabra Philippi, 1844 and a lectotype for Rissoa oranica Pallary, 1900 to stabilize the use of the names.

Disseminated Disease by Mycobacterium abscessus and Mycobacterium celatum in an Immunocompromised Host.

BACKGROUND Nontuberculous mycobacteria (NTM) are environmental pathogens that cause an increasing number of diseases, in particular in immunosuppressed patients. Diagnosing NTM infections may be difficult because clinical presentation is unspecific and resembles other conditions such as tuberculosis, lymphomas, or septicemia. CASE REPORT We report the case of a 62-year-old male with a recent history of autologous bone marrow transplantation for a follicular lymphoma admitted to our department for long-lasting remittent fever and abscess-like splenic nodules.

Insights into Cisplatin Binding to Uracil and Thiouracils from IRMPD Spectroscopy and Tandem Mass Spectrometry.

The monofunctional primary complexes -[PtCl(NH)(L)], formed by the reaction of cisplatin, a major chemotherapeutic agent, with four nucleobases L, i.e., uracil (U), 2-thiouracil (2SU), 4-thiouracil (4SU), and 2,4-dithiouracil (24dSU), have been studied by a combination of infrared multiple photon dissociation (IRMPD) action spectroscopy in both the fingerprint (900-1900 cm) and the N-H/O-H stretching (3000-3800 cm) ranges, energy-resolved collision-induced dissociation (CID) mass spectrometry, and density functional calculations at the B3LYP/LACVP/6-311G** level.

Skin and soft tissue infection by in an immunocompetent patient.

Nontuberculous mycobacteria (NTM) infections still represent a large group of insidious diseases hard to deal with. Traditionally, immunocompromised patients suffer from NTM infections, especially with respiratory involvement or disseminated diseases due to MAC ( complex). Here we report a rare case of infection involving skin and soft tissue, manifested as a chronic cutaneous ulcer in an immunocompetent patient with several comorbidities, including seizures.

Infrared-Assisted Synthesis of Prebiotic Glycine.

A novel approach has been developed to synthesize complex organic molecules (COMs) relevant to prebiotic chemistry, using infrared (IR) radiation to trigger the reaction. An original laboratory reactor working at low gas density and using IR irradiation was developed. In this way, glycine, the simplest brick of life, has been synthesized by assisting ion-molecule reaction with IR laser light.

Applications of Infrared Multiple Photon Dissociation (IRMPD) to the Detection of Posttranslational Modifications.

Infrared multiple photon dissociation (IRMPD) spectroscopy allows for the derivation of the vibrational fingerprint of molecular ions under tandem mass spectrometry (MS/MS) conditions. It provides insight into the nature and localization of posttranslational modifications (PTMs) affecting single amino acids and peptides. IRMPD spectroscopy, which takes advantage of the high sensitivity and resolution of MS/MS, relies on a wavelength specific fragmentation process occurring on resonance with an IR active vibrational mode of the sampled species and is well suited to reveal the presence of a PTM and its impact in the molecular environment.

A Collaborative Academic-Practice Approach to Meeting Educational and Workforce Needs.

This article describes an innovative academic-practice partnership designed to promote new nurse competency and meet employer needs for graduates with in-demand knowledge and competencies in specialty patient populations. Three practice partners identified areas of need and with the school of nursing developed specialty nursing elective courses with precepted clinical experiences.

Effects of complexation with sulfuric acid on the photodissociation of protonated Cinchona alkaloids in the gas phase.

The effect of complexation with sulfuric acid on the photo-dissociation of protonated Cinchona alkaloids, namely cinchonidine (Cd), quinine (Qn) and quinidine (Qd), is studied by combining laser spectroscopy with quantum chemical calculations. The protonated complexes are structurally characterized in a room-temperature ion trap by means of infra-red multiple photon dissociation (IRMPD) spectroscopy in the fingerprint and the ν(XH) (X = C, N, O) stretch regions. Comparison with density functional theory calculations including dispersion (DFT-D) unambiguously shows that the complex consists of a doubly protonated Cinchona alkaloid strongly bound to a bisulfate HSO4- anion, which bridges the two protonated sites of the Cinchona alkaloid.

Vibrational signatures of curcumin's chelation in copper(II) complexes: An appraisal by IRMPD spectroscopy.

Curcumin (Cur) is a natural polyphenol with a wide spectrum of biological activities and appealing therapeutic potential. Herein, it has been delivered by electrospray ionization as gaseous protonated species, [Cur + H], and as a Cu(ii) complex, [Cu(Cur - H)], a promising antioxidant and radical scavenger. The gas phase structures were assayed by infrared multiple photon dissociation (IRMPD) spectroscopy in both the fingerprint (800-2000 cm) and hydrogen stretching (3100-3750 cm) ranges.

l-Cysteine Modified by S-Sulfation: Consequence on Fragmentation Processes Elucidated by Tandem Mass Spectrometry and Chemical Dynamics Simulations.

Low-energy collision-induced dissociation (CID) of deprotonated l-cysteine S-sulfate, [cysS-SO], delivered in the gas phase by electrospray ionization, has been found to provide a means to form deprotonated l-cysteine sulfenic acid, which is a fleeting intermediate in biological media. The reaction mechanism underlying this process is the focus of the present contribution. At the same time, other novel species are formed, which were not observed in previous experiments.