An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane.

The vibrational analysis of the gas-phase infrared spectra of chlorofluoromethane (CH2ClF, HCFC-31) was carried out in the range 200-6200 cm(-1). The assignment of the absorption features in terms of fundamental, overtone, combination, and hot bands was performed on the medium-resolution (up to 0.2 cm(-1)) Fourier transform infrared spectra.

Conformational analysis of Gly-Ala-NHMe in D(2)O and DMSO solutions: a two-dimensional infrared spectroscopy study.

A relevant number of experiments on short peptides has been performed in recent years. One of the major problems rises from the simultaneous presence of slightly different conformers at equilibrium in solution. In the present paper, the conformational characteristics of the Gly-l-Ala-Methyl amide dipeptide in D2O and DMSO solutions are investigated by nonlinear IR spectroscopy.

Oral liquid levothyroxine treatment at breakfast: a mistake?

Objective: Taking levothyroxine (L-T₄) with coffee or with water followed by coffee intake within a few minutes results in poor TSH response in many patients. T₄ is available in tablet form worldwide, but novel formulations in soft gel capsule or liquid form are now available.

Design: We fortuitously identified a euthyroid patient who wrongly consumed liquid L-T₄ with coffee at breakfast; after changing the time of consumption to 30 min before breakfast, no change in TSH, free T₄ (fT₄), and free tri-iodothyronine (fT₃) concentrations was observed.

Ultrasound findings of subacute thyroiditis: a single institution retrospective review.

Background: High resolution ultrasonography features have also been described as having a useful supporting role in the diagnosis of subacute granulomatous thyroiditis (ST), and images are generally characterized by heterogeneous hypoechoic areas of the affected tissue with lack of flow on color Doppler US.

Purpose: To determine the sonographic features of subacute granulomatous thyroiditis.

Material And Methods: We reviewed the medical records of patients referred at the Endocrine and Metabolic Unit of our Institution between January 2010 and December 2011.

Anharmonic theoretical simulations of infrared spectra of halogenated organic compounds.

The recent implementation of the computation of infrared (IR) intensities beyond the double-harmonic approximation [J. Bloino and V. Barone, J.

Duschinsky, Herzberg-Teller, and Multiple Electronic Resonance Interferential Effects in Resonance Raman Spectra and Excitation Profiles. The Case of Pyrene.

We show that a recently developed time-independent approach for the calculation of vibrational resonance Raman (vRR) spectra is able to describe Duschinsky and Herzberg-Teller (HT) effects acting on a single resonant state, together with interferential contributions arising from multiple electronic resonances, allowing us to investigate in detail how their interplay determines both the vRR spectra at selected wavelengths and the Raman excitation profiles. We apply this methodology to the study of the spectra of pyrene in acetonitrile, an ideal system since it exhibits three close-lying electronic transitions that are bright but also subjected to HT effects. To single out the different contributions to vRR line shapes we adopted two different adiabatic models for resonant-state potential energy surfaces, namely, Adiabatic Shift (only accounting from equilibrium geometry displacements) and Adiabatic Hessian (AH, including also the Duschinsky effects), and Franck-Condon (FC) or HT approximations for the transition dipole.

Validation of quantitative structure-activity relationship models to predict water-solubility of organic compounds.

Water-solubility is an important physicochemical property in pharmaceutical and environmental studies. We assessed the performance of five predictive computer models: ACD/PhysChem History, ADMET Predictor, T.E.

Development of a virtual spectrometer for chiroptical spectroscopies: the case of nicotine.

The impressive advances of computational spectroscopy in most recent years are providing robust and user-friendly multifrequency virtual spectrometers, which can also be used by nonspecialists to complement experimental studies. At the heart of these developments there are latest-generation models based on Density Functional Theory for the proper treatment of stereo-electronic effects, coupled to the polarizable continuum model to deal with bulk solvent effects, and low-order perturbative treatments of anharmonic effects. Continuing our efforts to increase the range of application of virtual spectrometers, we report here about chiroptical spectroscopies with special reference to optical rotation and vibrational circular dichroism.

Vertical Electronic Excitations in Solution with the EOM-CCSD Method Combined with a Polarizable Explicit/Implicit Solvent Model.

The accurate calculation of electronic transition energies and properties of isolated chromophores is not sufficient to provide a realistic simulation of their excited states in solution. In fact, the solvent influences the solute geometry, electronic structure, and response to external fields. Therefore, a proper description of the solvent effect is fundamental.

Oral liquid L-thyroxine (L-t4) may be better absorbed compared to L-T4 tablets following bariatric surgery.

Drug malabsorption is a potential concern after bariatric surgery. We present four case reports of hypothyroid patients who were well replaced with thyroxine tablets to euthyroid thyrotropin (TSH) levels prior to Roux-en-Y gastric bypass surgery. These patients developed elevated TSH levels after the surgery, the TSH responded reversibly to switching from treatment with oral tablets to a liquid formulation.

A gauge invariant multiscale approach to magnetic spectroscopies in condensed phase: general three-layer model, computational implementation and pilot applications.

Analytical equations to calculate second order electric and magnetic properties of a molecular system embedded into a polarizable environment are presented. The treatment is limited to molecules described at the self consistent field level of theory, including Hartree-Fock theory as well as Kohn-Sham density functional theory and is extended to the Gauge-Including Atomic Orbital method. The polarizable embedding is described by means of our already implemented polarizable quantum mechanical/molecular mechanical (MM) methodology, where the polarization in the MM layer is handled by means of the fluctuating charge (FQ) model.

Feasibility of robotic pancreaticoduodenectomy.

Background: Laparoscopic pancreaticoduodenectomy is feasible, but requires adaptations to established surgical techniques. The improved dexterity offered by robotic assistance provides the opportunity to see whether laparoscopic pancreaticoduodenectomy can be performed safely when faithfully reproducing the open operation.

Methods: Patients were selected for robotic pancreaticoduodenectomy when generally suitable for laparoscopy.

The Optical Rotation of Methyloxirane in Aqueous Solution: A Never Ending Story?

The long-standing problem of the calculation of the optical rotation (OR) of (R)-methyloxirane in aqueous solution at different wavelengths is solved by means of a novel gauge-invariant computational protocol able to take into account at the same time for intramolecular averaging specific and bulk solvent effects, leading for the first time to a quantitative agreement (both sign and absolute value) between computed and experimental OR values at several frequencies.

Adjuvant chemotherapy seems beneficial for invasive intraductal papillary mucinous neoplasms.

Aims: The incidence of intraductal papillary mucinous neoplasm (IPMN) is rising and these neoplasms now represent up to 25% of resected pancreatic neoplasms. The optimal postoperative management of resected invasive IPMN is still debated in the absence of large prospective clinical trials and of validated prognostic factors in this setting. The objective of our study was to identify potential prognostic factors and to investigate the role of adjuvant therapies for patients radically resected for invasive IPMN.

Computational design, synthesis, and mechanochromic properties of new thiophene-based π-conjugated chromophores.

The possibility of exploiting supramolecular architectures for the preparation of innovative mechanochromic devices has been extended by designing novel thienyl-substituted 1,4-bis(ethynyl)benzene dyes, which are characterized by a conjugated, rigid, rodlike core structure. This new family of chromophores was synthesized according to a simple two-step sequential cross-coupling reaction, and the optical properties were investigated in solution and in a polymeric matrix. To tune the mechanochromic performances in smart polymer materials, a virtual screening was set up that was able to select a derivative with optimal spectral features.

Analytical First and Second Derivatives for a Fully Polarizable QM/Classical Hamiltonian.

In this work, we present the derivation and implementation of analytical first and second derivatives for a fully polarizable QM/MM/PCM energy functional. First derivatives with respect to both QM- and MM-described nuclear coordinates and electric perturbations are derived and implemented, and some preliminary application is shown. Analytical second derivatives with respect to nuclear and electric perturbations are then derived, and some numerical test is presented both for a solvated system and for a cromophore embedded in a biological matrix.

Linear Response Theory and Electronic Transition Energies for a Fully Polarizable QM/Classical Hamiltonian.

A fully polarizable quantum/classical Hamiltonian including SCF (HF or DFT), fluctuating charge, and polarizable continuum regions is introduced and implemented for electronic energies of ground and excited states, using, in the latter case, a linear response formulation. After calibration and validation of the approach, preliminary results are presented for pyrimidine in aqueous solution and for retinal in a rhodopsin mimic. The results are consistent with more tested methodologies and pave the route toward fully consistent yet effective simulations of large systems of technological and/or biological interest in their natural environments.

Real-time elastography: a useful tool for predicting malignancy in thyroid nodules with nondiagnostic cytologic findings.

Objectives: The aim of this study was to evaluate the predictive value of sonography and sonographic elastography in thyroid nodules with nondiagnostic cytologic findings.

Methods: The study included 101 patients (74 female, mean age ± SD, 55 ± 11 years [range, 27-70 years]; and 27 male, mean age, 62 ± 9 years [range, 42-72 years]) who had at least 1 nodule with nondiagnostic cytologic findings at two different fine-needle aspiration cytologic evaluations and with an indication for hemi or total thyroidectomy for clinical suspicion of malignancy, nodule size, or the occurrence of a coexisting nodule with cytologic findings suspicious for malignancy. All of the patients underwent sonography and elastography 2 months after the second fine-needle aspiration and before surgery.

Calculation and analysis of the harmonic vibrational frequencies in molecules at extreme pressure: methodology and diborane as a test case.

We present a new quantum chemical method for the calculation of the equilibrium geometry and the harmonic vibrational frequencies of molecular systems in dense medium at high pressures (of the order of GPa). The new computational method, named PCM-XP, is based on the polarizable continuum model (PCM), amply used for the study of the solvent effects at standard condition of pressure, and it is accompanied by a new method of analysis for the interpretation of the mechanisms underpinning the effects of pressure on the molecular geometries and the harmonic vibrational frequencies. The PCM-XP has been applied at the density functional theory level to diborane as a molecular system under high pressure.

Implementation and validation of a multi-purpose virtual spectrometer for large systems in complex environments.

Despite impressive advances of computational spectroscopy, a robust and user-friendly multi-frequency virtual spectrometer is not yet available. This contribution summarises ongoing efforts in our research group toward the implementation and validation of such a tool with special reference to the building blocks of biomolecules in their natural environment. Our integrated computational tool allows the computation of several kinds of spectra, including vibrational (e.

Toward Ab Initio Anharmonic Vibrational Circular Dichroism Spectra in the Condensed Phase.

The first implementation and calculation of anharmonic VCD rotational strengths for solvated systems is reported. Our approach, rooted in the polarizable continuum model (PCM) and in the second-order vibrational perturbation theory (VPT2), permits not only correction for anharmonicity in the signals associated with fundamental transitions but also calculation of rotational strengths of overtones and combination bands. This allows for a more physically consistent comparison between experiment and calculations together with the analysis of spectral regions dominated by anharmonic effects.

Thyreotropin levels in diabetic patients on metformin treatment.

Objective: A retrospective study to evaluate the changes in TSH concentrations in diabetic patients treated or not treated with metformin and/or L-thyroxine (L-T(4)).

Methods: Three hundred and ninety three euthyroid diabetic patients were divided into three groups on the basis of metformin and/or L-T(4) treatment: Group (M-/L-), 119 subjects never treated with metformin and L-T(4); Group (M+/L-), 203 subjects who started metformin treatment at recruitment; and Group (M+/L+), 71 patients on L-T(4) who started metformin recruitment.

Results: The effect of metformin on serum TSH concentrations was analyzed in relation to the basal value of TSH (below 2.

Predictive factors for postoperative severe hypocalcaemia after parathyroidectomy for primary hyperparathyroidism.

Hypocalcaemia is a complication of parathyroidectomy. We retrospectively analyzed data on patients who underwent parathyroidectomy for primary hyperparathyroidism (pHPT) to identify predictive factors for severe postoperative hypocalcaemia. Since 2004 we performed 87 parathyroidectomies for pHPT.

Toward an Accurate Modeling of Optical Rotation for Solvated Systems: Anharmonic Vibrational Contributions Coupled to the Polarizable Continuum Model.

We present a newly implemented methodology to evaluate vibrational contributions (harmonic and anharmonic) to the optical rotation of solvated systems described by means of the polarizable continuum model (PCM). Proper account of an incomplete solvation regime in the treatment of both the electronic property and the molecular vibrations is considered, as well as the inclusion of cavity field effects. In order to assess the quality of our approach, test calculations on (R)-methyloxirane in various solvents and (S)-N-acetylproline amide in cyclohexane and aqueous solution are presented.