Toward Detection of the Molecular Parity Violation in Chiral Ru(acac) and Os(acac).

We present a theory-experiment investigation of the helically chiral compounds Ru(acac) and Os(acac) as candidates for next-generation experiments for detection of molecular parity violation (PV) in vibrational spectra. We used relativistic density functional theory calculations to identify optimal vibrational modes with expected PV effects exceeding by up to 2 orders of magnitude the projected instrumental sensitivity of the ultrahigh resolution experiment under construction at the Laboratoire de Physique des Lasers in Paris. Preliminary measurements of the vibrational spectrum of Ru(acac) carried out as the first steps toward the planned experiment are presented.

Determination of biomarkers of exposure to boscalid, captan, folpel, mancozeb and tebuconazole in urine and hair samples.

In order to develop a tiered approach to identify relevant biomarkers and matrices for assessing pesticide exposure in residents living close to vineyards, five priority pesticides (boscalid, captan, folpel, mancozeb and tebuconazole) and their metabolites were analyzed in urine and hair samples from the biobank of a French national prevalence study conducted between 2014 and 2016. To do this, several analytical methods based on gas chromatography coupled with tandem mass spectrometry (GC/MS/MS) were developed by relying on the expertise of the laboratory and the scientific literature, in particular on a paper describing the use of gas chromatography-mass spectrometry for the determination in human urine samples of ethylene thiourea (ETU), a metabolite of mancozeb, after a supported liquid extraction followed by a derivatization step [1]. The main adaptations carried out as part of this study concerned:•the determination of ethylene urea (EU), another metabolite of mancozeb, at the same time as ETU in urine samples•the determination of all substances of interest including boscalid, EU and ETU, folpel and one of its metabolite (phthalimide), tebuconazole and one of its metabolite (hydroxytebuconazole), and tetrahydrophthalimide (metabolite of captan) in organic hair extracts by GC/MS/MS after a derivatization step.

Rotranslational dynamics of confined water. II. Spectroscopic evidence of confinement effects on the far-infrared spectra of water isotopologues in argon and krypton matrices.

Water molecules trapped in rare gas matrices exhibit conspicuous shifts in their far-infrared (FIR), rotranslational spectral features compared with the corresponding transitions observed in the gas phase. These confinement-induced perturbations have been related not only to the quantization of translational motion but also to the coupling between the orientational and positional degrees of freedom: the rotation-translation coupling (RTC). As the propensity displayed by the nuclear spin isomers (NSI) of water to undergo interconversion in confinement is intimately related to how its nuclear spin degrees of freedom are coupled with those for intra- and intermolecular motions, confinement-induced RTC should also strongly impact the NSI interconversion mechanisms and rates.

Identification of pesticides exposure biomarkers for residents living close to vineyards in France.

Biomonitoring can be relevant for assessing pesticides exposure of residents living close to vineyards (LCTV). However, because xenobiotics are generally present at low levels in human biological matrices and the sources of pesticide exposure are multiple, several challenges need to be overcome to reliably assess exposure in residents LCTV. This includes particularly identifying the most appropriate exposure biomarkers, the biological matrices in which they should be measured, and analytical methods that are sufficiently sensitive and specific to quantify them.

MAIT cell alterations in adults with recent-onset and long-term type 1 diabetes.

Aims/hypothesis: Mucosal-associated invariant T (MAIT) cells are innate-like T lymphocytes expressing an αβ T cell antigen receptor that recognises the MHC-related 1 molecule. MAIT cells are altered in children at risk for and with type 1 diabetes, and mouse model studies have shown MAIT cell involvement in type 1 diabetes development. Since several studies support heterogeneity in type 1 diabetes physiopathology according to the age of individuals, we investigated whether MAIT cells were altered in adults with type 1 diabetes.

Outcome of SARS-CoV-2 infection is linked to MAIT cell activation and cytotoxicity.

Immune system dysfunction is paramount in coronavirus disease 2019 (COVID-19) severity and fatality rate. Mucosal-associated invariant T (MAIT) cells are innate-like T cells involved in mucosal immunity and protection against viral infections. Here, we studied the immune cell landscape, with emphasis on MAIT cells, in cohorts totaling 208 patients with various stages of disease.

Mechanical properties of 2D aggregates of oil droplets as model mono-crystals.

We investigate the elastic and yielding properties of two dimensional defect-free mono-crystals made of highly monodisperse droplets. Crystals are compressed between two parallel boundaries of which one acts as a force sensor. As the available space between boundaries is reduced, the crystal goes through successive row-reduction transitions.

Microscopic Picture of Erosion and Sedimentation Processes in Dense Granular Flows.

Gravity-driven flows of granular matter are involved in a wide variety of situations, ranging from industrial processes to geophysical phenomena, such as avalanches or landslides. These flows are characterized by the coexistence of solid and fluid phases, whose stability is directly related to the erosion and sedimentation occurring at the solid-fluid interface. To describe these mechanisms, we build a microscopic model involving friction, geometry, and a nonlocal cooperativity emerging from the propagation of collisions.

Synchrotron-Based High Resolution Far-Infrared Spectroscopy of -Butadiene.

The high resolution far-infrared spectrum of -butadiene has been reinvestigated by Fourier-transform spectroscopy at two synchrotron radiation facilities, SOLEIL and the Canadian Light Source, at temperatures ranging from 50 to 340 K. Beyond the well-studied bands, two new fundamental bands lying below 1100 cm, ν and ν, have been assigned using a combination of cross-correlation (ASAP software) and Loomis-Wood type (LWWa software) diagrams. While the ν analysis was rather straightforward, ν exhibits obvious signs of a strong perturbation, presumably owing to interaction with the dark ν + ν state.

Infrared Spectroscopy and Density Functional Theory Investigations of the Reactivity of Titanium Atoms with Carbon Monoxide and Water Isolated in Solid Argon: Sequential Evolution from Triplet to Singlet State.

Thermally evaporated titanium atoms reacted with carbon monoxide and water in solid argon at 12 K to produce the HTiOH-CO and HTiOH-(CO) molecules, which were characterized using infrared spectroscopy on the basis of CO, Ti, and water concentration variations and of isotopic substitutions. The insertion product, HTiOH, resulting from the reaction of a titanium atom with a water molecule reacts with CO spontaneously to give the HTiOH-CO molecule, which in turn reacts with a second CO molecule to give HTiOH-(CO) The density functional theory calculations were performed to elucidate the geometrical and electronic structures and support the spectral assignments. The topological analysis of the charge density within the experimentally observed molecules allowed us to rationalize the coordination sphere as well as the electron pairing on the titanium center.

On-line coupling of thermal extraction with gas chromatography / tandem mass spectrometry for the analysis of semivolatile organic compounds in a few milligrams of indoor dust.

An original multiresidue method based on thermal extraction (TE) and gas chromatography/tandem mass spectrometry (GC/MS/MS) was developed to simultaneously quantify, from a very small amount of sample (a few milligrams), a wide range of concerning SVOCs, including polycyclic musks, organochlorines (OCs), organophosphates (OPs), oxadiazolones, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), phthalates and pyrethroids, in indoor settled dust. Method limits of quantification (LOQs) ranged from 5 ng g for PCBs, oxadiazon, 4,4'-DDE and 4,4'-DDT to 2000 ng g for DEHP for a 2 mg sample of sieved dust. The proposed method was successfully validated in terms of accuracy and precision via replicate analysis of four different standard reference materials (SRMs 1649b (Urban Dust), 2585 (Organic Contaminants in House Dust), 2786 and 2787 (Fine Atmospheric Particulate Matter)) supplied by the National Institute of Standards and Technology (NIST) and was applied to five real indoor settled dust samples collected in French schools.

Jet-cooled rovibrational spectroscopy of methoxyphenols using two complementary FTIR and QCL based spectrometers.

Methoxyphenols (MPs) are a significant component of biomass burning emissions which mainly exists in our atmosphere in the gas phase where they contribute to the formation of secondary organic aerosols (SOAs). Rovibrational spectroscopy is a promising tool to monitor atmospheric MPs and infer their role in SOA formation. In this study, we bring a new perspective on the rovibrational analysis of MP isomers by taking advantage of two complementary devices combining jet-cooled environments and absorption spectroscopy: the Jet-AILES and the SPIRALES setups.

Vibrational study in neon matrix of HS-HO, HS-(HO), and (HS)-HO complexes. Identification of the two isomers: HOH-SH (HO proton donor) and HSH-OH (HS proton donor).

For the first time, the investigation of water molecules complexed with hydrogen sulfide in solid neon was performed from 80 to 6000 cm using Fourier transform infrared spectroscopy. In the first step, we identify the ν and ν frequencies of the proton donor in the HS dimer. From concentration effects and with the help of theoretical results, we have highlighted the presence of the two stable isomers, HOH-SH where HO is the proton donor and HSH-OH where HS is the proton donor.

Infrared Spectroscopy and Density Functional Theory Investigations of PdTi Heterodimer Reactivity with Carbon Monoxide Isolated in Solid Argon.

The reactivity of diatomic palladium-titanium toward carbon monoxide has been studied in solid argon by infrared spectroscopy (Fourier transform infrared) in the carbonyl stretching frequency region. Our technique of sublimation of Ti and Pd atoms from two filaments heated separately allowed the identification of five new molecules. Small polynuclear carbonyl clusters, PdTi(CO) ( n = 1-3), have been characterized on the basis of isotopic substitutions, metal atom and CO concentration variations, and irradiation effects.

First vibrational investigations of NO-HO, NO-(HO), and (NO)-HO complexes from the far to the near-infrared spectral region by neon matrix isolation and calculations.

We present for the first time the investigation of water molecules complexed with dinitrogen monoxide, two abundant molecules in atmosphere, in solid neon using Fourier transform infrared (IR) spectroscopy. We identify at least three complexes from concentration effects, NO-HO, NO-(HO), and (NO)-HO, by observation of new absorption bands close to the monomer fundamental modes from the far to the near IR region. We highlight the presence of isomers for the NO-HO complex with the help of theoretical calculations at second order Møller-Plesset (MP2) and coupled-cluster single double triple-F12a/aug-cc-pVTZ levels.

Adhesion-induced fingering instability in thin elastic films under strain.

In this study, thin elastic films supported on a rigid substrate are brought into contact with a spherical glass indenter. Upon contact, adhesive fingers emerge at the periphery of the contact patch with a characteristic wavelength. Elastic films are also pre-strained along one axis before the initiation of contact, causing the fingering pattern to become anisotropic and align with the axis along which the strain was applied.

Nuclear Spin Symmetry Conservation in HO Investigated by Direct Absorption FTIR Spectroscopy of Water Vapor Cooled Down in Supersonic Expansion.

We report the results of an experimental study related to the relaxation of the nuclear spin isomers of the water molecule in a supersonic expansion. Rovibrational lines of both ortho and para spin isomers were recorded in the spectral range of HO stretching vibrations at around 3700 cm using FTIR direct absorption. Water vapor seeded in argon, helium, or oxygen or in a mixture of oxygen and argon was expanded into vacuum through a slit nozzle.

First infrared investigations of OCS-HO, OCS-(HO), and (OCS)-HO complexes isolated in solid neon: Highlighting the presence of two isomers for OCS-HO.

For the first time, complexes involving carbonyl sulfide (OCS) and water molecules are studied by FTIR in solid neon. Many new absorption bands close to the known fundamental modes for the monomers give evidence for at least three (OCS)-(H2O) complexes, noted n:m. With the help of theoretical calculations, two isomers of the 1:1 complex are clearly identified.

Competition between inter- and intra-molecular hydrogen bonding: An infrared spectroscopic study of jet-cooled amino-ethanol and its dimer.

The Fourier transform IR vibrational spectra of amino-ethanol (AE) and its dimer have been recorded at room temperature and under jet-cooled conditions over the far and mid infrared ranges (50-4000 cm) using the White-type cell and the supersonic jet of the Jet-AILES apparatus at the synchrotron facility SOLEIL. Assignment of the monomer experimental frequencies has been derived from anharmonic frequencies calculated at a hybrid CCSD(T)-F12/MP2 level. Various thermodynamical effects in the supersonic expansion conditions including molar dilution of AE and nature of carrier gas have been used to promote or not the formation of dimers.

Conformational Landscape of the 1/1 Diacetyl/Water Complex Investigated by Infrared Spectroscopy and ab Initio Calculations.

The complexes of diacetyl with water have been studied experimentally by Fourier transform infrared (FTIR) spectroscopy coupled to solid neon matrix and supersonic jet, and anharmonic ab initio calculations. The vibrational analysis of neon matrix spectra over the 100-7500 cm infrared range confirms the existence of two nearly isoenergetic one-to-one (1/1) diacetyl-water S and S isomers already evidenced in a previous argon matrix study. A third form (S) predicted slightly less stable ( J.

Vibrational investigations of CO2-H2O, CO2-(H2O)2, and (CO2)2-H2O complexes isolated in solid neon.

The van der Waals complex of H2O with CO2 has attracted considerable theoretical interest as a typical example of a weak binding complex with a dissociation energy less than 3 kcal/mol. Up to now, experimental vibrational data are sparse. We have studied by FTIR the complexes involving CO2 and water molecules in solid neon.

Standard free energy of the equilibrium between the trans-monomer and the cyclic-dimer of acetic acid in the gas phase from infrared spectroscopy.

Survey jet-cooled spectra of acetic acid have been recorded in the infrared region (200-4000 cm(-1)) over a wide range of expansion conditions. From the variations of the relative intensities of the signals, vibrational transitions have been assigned unambiguously to the trans-monomer and cyclic-dimer. The IR-active fundamental frequencies have been determined at the instrumental accuracy of 0.

The cyclic ground state structure of the HF trimer revealed by far infrared jet-cooled Fourier transform spectroscopy.

The rovibrationally resolved Fourier transform (FT) far infrared (FIR) spectra of two intermolecular librations of (HF)3, namely the in-plane ν6 and out-of-plane ν4 bending fundamentals centered, respectively, at about 494 cm(-1) and 602 cm(-1), have been recorded for the first time under jet-cooled conditions using the supersonic jet of the Jet-AILES apparatus. The simultaneous rotational analysis of 245 infrared transitions belonging to both bands enabled us to determine the ground state (GS), ν6 and ν4 rotational and centrifugal distortion constants. These results provided definite experimental answers to the structure of such a weakly bound trimer: firstly the vibrationally averaged planarity of cyclic (HF)3, also supported by the very small value of the inertia defect obtained in the GS, secondly the slight weakening of the hydrogen bond in the intermolecular excited states evidenced from the center of mass separations of the HF constituents determined in the ground, ν6 = 1 and ν4 = 1 states of (HF)3 as well as the decrease of the fitted rotational constants upon excitation.

Structural and dynamic properties of a hydrogen bond from the study of the CH3Cl-HCl complex and isotopic species.

The microwave (4-20 GHz range) and infrared (HCl and DCl stretch ranges) spectra of six isotopic species of the CH3Cl-HCl hydrogen bond complex have been recorded for the first time and analyzed with the support of high level ab initio calculations (MP2 and CCSD(T) levels). Accurate molecular parameters, including rotational, quartic centrifugal distortion, and nuclear-quadrupole coupling constants, vibrational frequencies, and anharmonic coupling constants, are presented in this paper. These parameters have then been used to estimate the hydrogen bond geometry and confirm the strong coupling between intramolecular and low frequency intermolecular modes.

The far infrared spectrum of naphthalene characterized by high resolution synchrotron FTIR spectroscopy and anharmonic DFT calculations.

Using synchrotron radiation, we performed the rotationally resolved Fourier transform infrared absorption spectroscopy of three bands of naphthalene C10H8, namely ν(46)-0 (centered at 782 cm(-1), 12.7 μm), ν(47)-0 (centered at 474 cm(-1), 21 μm), and ν(48)-0 (centered at 167 cm(-1), 60 μm). The intense CH bending out of plane ν(46)-0 band was recorded under supersonic jet-cooled conditions using a molecular beam (the Jet-AILES apparatus) and the low frequency ν(47)-0 and ν(48)-0 bands were measured at room temperature in a long absorption path cell.