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1.
J Endocrinol Invest ; 46(9): 1825-1834, 2023 Sep.
Article En | MEDLINE | ID: mdl-36884196

PURPOSE: Primary hypothyroidism is a main endocrine complication after allogeneic stem cells transplantation (allo-SCT) in children, but in adults data on post-SCT hypothyroidism are limited. The aims of this observational, cross-sectional study were to assess the prevalence of hypothyroidism in adult allo-SCT recipients according to time from transplantation, and to identify risk factors. METHODS: One hundred and eighty-six patients (M 104; F 82; median age 53.4 years) who underwent allo-SCT between January 2010 and December 2017 were enrolled and divided into three groups, according to time from allo-SCT (1-3 years; 3-5 years; > 5 years). Pre-transplant TSH and fT4 levels were available for all patients. After transplantation, TSH, fT4 and anti-thyroperoxidase antibodies (TPO-Ab) were evaluated. RESULTS: After a follow-up of 3.7 years, 34 (18.3%) patients developed hypothyroidism, with higher prevalence in females (p < 0.001) and in patients who received matched unrelated donor grafts (p < 0.05). No difference in prevalence was found at different time points. Patients who developed hypothyroidism showed higher rate of TPO-Ab positivity (p < 0.05) and higher pre-transplant TSH levels (median 2.34 µU/ml) compared to those with preserved thyroid function (median 1.53 µU/ml; p < 0.001). Multivariable analysis identified higher pre-transplant TSH levels as a positive predictor of hypothyroidism (p < 0.005). The ROC curve analysis identified a pre-SCT TSH cutoff of 1.84 µU/ml, which can predict hypothyroidism with sensitivity 74.1% and specificity 67.2%. CONCLUSIONS: About one out of four patients developed hypothyroidism after allo-SCT, with a greater incidence in females. Pre-transplant TSH levels seem to predict the onset of post-SCT hypothyroidism.


Hematopoietic Stem Cell Transplantation , Hypothyroidism , Adult , Child , Female , Humans , Middle Aged , Cross-Sectional Studies , Transplantation, Homologous/adverse effects , Hematopoietic Stem Cell Transplantation/adverse effects , Hypothyroidism/epidemiology , Hypothyroidism/etiology , Thyrotropin
2.
J Endocrinol Invest ; 44(11): 2427-2433, 2021 Nov.
Article En | MEDLINE | ID: mdl-33837920

PURPOSE: Postoperative assessment of acromegaly activity is typically performed at least 3 months after neurosurgery (NS). Few studies have evaluated the use of early postoperative growth hormone (GH) levels as a test to predict short- and long-term remission of acromegaly. Our objective was to evaluate the diagnostic performance of serum random GH on a postoperative day one (D1-rGH) and two (D2-rGH), particularly in predicting long-term disease persistence. MATERIALS AND METHODS: Forty-one subjects with acromegaly who were undergoing NS were enrolled (mean age ± SD 47.4 ± 13.1 years at diagnosis; women 54%; macroadenomas 71%). The final assessment of disease activity was performed one year after NS. ROC curves were used to evaluate the diagnostic performance of D1-rGH and D2-rGH. RESULTS: After a 1-year follow-up, the overall remission rate was 55%. ROC analysis identified an optimal D1-rGH cut-off value of 2.1 ng/mL for diagnosing long-term disease persistence (55.6% SE; 90.9% SP). The cut-off point became 2.5 ng/mL after maximizing specificity for disease persistence (yielding a 100% positive predictive value) and 0.3 ng/mL after maximizing sensitivity for disease remission. The optimal D2-rGH cut-off value was 0.6 ng/mL (81.8% SE; 50% SP); the cut-off point became 2.9 ng/mL after maximizing specificity and 0.1 ng/mL after maximizing sensitivity, with no clinical utility. CONCLUSIONS: D1-rGH could be a highly specific test for the early diagnosis of long-term acromegaly persistence, which is predicted by a value > 2.5 ng/mL with a great degree of certainty. The diagnostic performance of D2-rGH was insufficient. Further research is required to validate these preliminary results prior to modifying the postoperative management of acromegaly.


Acromegaly , Early Diagnosis , Human Growth Hormone/blood , Long Term Adverse Effects/diagnosis , Neurosurgical Procedures/methods , Postoperative Care , Acromegaly/blood , Acromegaly/diagnosis , Acromegaly/surgery , Female , Growth Hormone-Secreting Pituitary Adenoma/surgery , Humans , Male , Middle Aged , Patient Acuity , Postoperative Care/methods , Postoperative Care/standards , Predictive Value of Tests , Prognosis , ROC Curve , Remission Induction/methods , Sensitivity and Specificity
3.
Clin Radiol ; 76(2): 153.e17-153.e24, 2021 Feb.
Article En | MEDLINE | ID: mdl-32993880

Injury to the renal artery following blunt trauma is detected increasingly due to widespread and early use of multidetector computed tomography (CT), but optimal treatment remains controversial as no guidelines are available. This review illustrates the spectrum of imaging findings of traumatic renal artery dissection based on our experience, with the aim of understanding the physiopathology of ischaemic damage to the kidney, and the process of choosing the best therapeutic strategy (conservative, endovascular, surgical). Five main patterns of traumatic renal artery dissection are described: avulsion of renal hilum; dissection of the segmental renal branches; preocclusive main renal artery dissection; renal artery stenosis without flow limitation; thrombogenic renal artery intimal tear. In the polytrauma patient, management depends on various factors (haemodynamic status, associated lesions, time of diagnosis) rather than on the degree of renal artery stenosis. Non-operative management (NOM) is the preferred option in case of non-flow-limiting dissection of the renal artery and angio-embolisation is an important adjunct to NOM in cases of active bleeding. Embolisation of the renal artery stump may be the best option in cases of occlusive dissection, as catheter manipulation carries a high risk of vessel rupture. The therapeutic window for kidney revascularisation in cases of flow-limiting dissection of main renal artery may be variable. Endovascular stenting >4 h after trauma should be performed only if residual flow with preserved parenchymal perfusion is detected at angiography. Antiplatelet therapy administration is recommended in cases of stenting, but conditioned by the bleeding risk of the patient.


Multidetector Computed Tomography/methods , Renal Artery/diagnostic imaging , Renal Artery/injuries , Wounds, Nonpenetrating/diagnostic imaging , Wounds, Nonpenetrating/therapy , Conservative Treatment/methods , Endovascular Procedures/methods , Humans , Renal Artery/surgery , Treatment Outcome
4.
PLoS One ; 13(8): e0200910, 2018.
Article En | MEDLINE | ID: mdl-30133443

This paper describes the production and chemical separation of the 163Ho isotope that will be used in several nuclear physics experiments aiming at measuring the neutrino mass as well as the neutron cross section of the 163Ho isotope. For this purpose, several batches of enriched 162Er have been irradiated at the Institut Laue-Langevin high flux reactor to finally produce 6 mg or 100 MBq of the desired 163Ho isotope. A portion of the Er/Ho mixture is then subjected to a sophisticated chemical separation involving ion exchange chromatography to isolate the Ho product from the Er target material. Before irradiation, a thorough analysis of the impurity content was performed and its implication on the produced nuclide inventory will be discussed.


Holmium/chemistry , Holmium/isolation & purification , Radiochemistry/methods , Isotopes , Neutrons , Nuclear Physics
5.
Eur Phys J C Part Fields ; 75(3): 112, 2015.
Article En | MEDLINE | ID: mdl-25995704

The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of [Formula: see text]Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted [Formula: see text]Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.

7.
J Biomed Mater Res A ; 102(12): 4406-14, 2014 Dec.
Article En | MEDLINE | ID: mdl-24532089

The microstructural, mechanical, compositional, and degradative properties of a nerve conduit are known to strongly affect the regenerative process of the injured peripheral nerve. Starting from the fabrication of micropatterned collagen-based nerve guides, according to a spin-casting process reported in the literature, this study further investigates the possibility to modulate the degradation rate of the scaffolds over a wide time frame, in an attempt to match different rates of nerve regeneration that might be encountered in vivo. To this aim, three different crosslinking methods, that is, dehydrothermal (DHT), carbodiimide-based (EDAC), and glutaraldehyde-based (GTA) crosslinking, were selected. The elastically effective degree of crosslinking, attained by each method and evaluated according to the classical rubber elasticity theory, was found to significantly tune the in vitro half-life (t1/2 ) of the matrices, with an exponential dependence of the latter on the crosslink density. The high crosslinking efficacy of EDAC and GTA treatments, respectively threefold and fourfold when compared to the one attained by DHT, led to a sharp increase of the corresponding in vitro half-lives (ca., 10, 172, and 690 h, for DHT, EDAC, and GTA treated matrices, respectively). As shown by cell viability assays, the cytocompatibility of both DHT and EDAC treatments, as opposed to the toxicity of GTA, suggests that such methods are suitable to crosslink collagen-based scaffolds conceived for clinical use. In particular, nerve guides with expected high residence times in vivo might be produced by finely controlling the biocompatible reaction(s) adopted for crosslinking.


Biocompatible Materials/chemistry , Collagen/chemistry , Guided Tissue Regeneration/methods , Peripheral Nerves , Tissue Scaffolds/chemistry , 3T3 Cells , Animals , Carbodiimides/chemistry , Cross-Linking Reagents/chemistry , Glutaral/chemistry , Mice
8.
J Chem Phys ; 139(23): 234306, 2013 Dec 21.
Article En | MEDLINE | ID: mdl-24359366

A new general framework for treating the dynamics on intersecting multidimensional potential energy surfaces is presented. It rests on a sub-division of the nuclear coordinates into different classes, one of primary importance with large-amplitude displacements during the process of interest and another one with smaller displacements, thus permitting a more approximate description. The latter are treated within the well-known linear + quadratic vibronic coupling scheme, where, however, the expansion "coefficients" are general functions of the "primary" coordinates. This may be augmented by an effective-mode approach for further degrees of freedom acting as an environment for the dynamics of the original modes. Following the general considerations, the approach is applied to the nonadiabatic photodynamics of furan and is shown to allow for an eight-dimensional quantum treatment, of higher dimension than was possible so far. The influence of the various degrees of freedom on the dynamics and lifetime of furan due to nonadiabatic ring-opening is discussed.

9.
Rev Sci Instrum ; 84(8): 083905, 2013 Aug.
Article En | MEDLINE | ID: mdl-24007077

In a microcalorimetric neutrino mass experiment using the radioactive decay of (163)Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the (163)Ho fabrication), in the temperature range 70 mK-300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

10.
Phys Rev Lett ; 110(20): 201801, 2013 May 17.
Article En | MEDLINE | ID: mdl-25167396

The analysis of a combined data set, totaling 3.6 × 10(14) stopped muons on target, in the search for the lepton flavor violating decay µ(+) → e(+)γ is presented. The data collected by the MEG experiment at the Paul Scherrer Institut show no excess of events compared to background expectations and yield a new upper limit on the branching ratio of this decay of 5.7 × 10(-13) (90% confidence level). This represents a four times more stringent limit than the previous world best limit set by MEG.

11.
J Chem Phys ; 135(16): 164305, 2011 Oct 28.
Article En | MEDLINE | ID: mdl-22047237

The nonadiabatic photoinduced ring opening occurring in the two lowest excited singlet states of furan is investigated theoretically, using wave-packet propagation techniques. The underlying multidimensional potential energy surfaces (PESs) are obtained from ab initio computations, using the equation-of-motion coupled cluster method restricted to single and double excitations (EOM-CCSD), reported in earlier recent work [E. V. Gromov, A. B. Trofimov, F. Gatti, and H. Köppel, J. Chem. Phys. 133, 164309 (2010)]. Up to five nuclear degrees of freedom are considered in the quantum dynamical treatment. Four of them represent in-plane motion for which the electronic states in question (correlating with the valence (1)B(2)(V) and Rydberg (1)A(2)(3s) states at the C(2v) ground-state molecular configuration) have different symmetries, A(') and A(''), respectively. The fifth mode, representing out-of-plane bending of the oxygen atom against the carbon-atom plane, leads to an interaction of these states, as is crucial for the photoreaction. The nonadiabatic coupling and conical intersection cause an electronic population transfer on the order of ∼10 fs. Its main features, and that of the wave-packet motion, are interpreted in terms of properties of the PES. The lifetime due to the ring-opening process has been estimated to be around 2 ps. The dependence of this estimate on the nuclear degrees of freedom retained in the computations is discussed.


Furans/chemistry , Cyclization , Photochemical Processes , Quantum Theory
12.
Phys Rev Lett ; 107(17): 171801, 2011 Oct 21.
Article En | MEDLINE | ID: mdl-22107507

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton-flavor-violating decay µ(+)e(+)γ. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8×10(14) muon decays, gives a 90% C.L. upper limit of 2.4×10(-12) on the branching ratio of the µ(+)→e(+)γ decay, constituting the most stringent limit on the existence of this decay to date.

13.
J Chem Phys ; 133(16): 164309, 2010 Oct 28.
Article En | MEDLINE | ID: mdl-21033790

The potential energy surfaces (PESs) of the two lowest excited singlet states of furan [correlating with the Rydberg (1)A(2)(3s) and valence (1)B(2)(V) states at the C(2v) ground-state molecular configuration] have been studied in some detail with regard to the photoinduced ring-opening reaction. The surfaces have been characterized in terms of their stationary points and points of minimum energy conical intersections along the ring-opening pathway. The optimization of the geometrical parameters has been performed with the equation of motion coupled cluster singles and doubles method. The ab initio PESs have been modeled by energy grids and Taylor series. The resulting 11-dimensional PESs reproduce the ab initio results to a good accuracy and can be used in dynamical calculations.

14.
J Chem Phys ; 133(14): 144308, 2010 Oct 14.
Article En | MEDLINE | ID: mdl-20950001

Two-dimensional, three-dimensional, and four-dimensional quantum dynamic calculations are performed on the dissociative chemisorption of CH(4) on Ni(111) using the multiconfiguration time-dependent Hartree (MCTDH) method. The potential energy surface used for these calculations is 15-dimensional (15D) and was obtained with density functional theory for points which are concentrated in the region that is dynamically relevant to reaction. Many reduced dimensionality calculations were already performed on this system, but the molecule was generally treated as pseudodiatomic. The main improvement of our model is that we try to describe CH(4) as a polyatomic molecule by including a degree of freedom describing a bending vibration in our three-dimensional and four-dimensional models. Using a polyspherical coordinate system, a general expression for the 15D kinetic energy operator is derived, which discards all the singularities in the operator and includes rotational and Coriolis coupling. We use seven rigid constraints to fix the CH(3) umbrella of the molecule to its gas phase equilibrium geometry and to derive two-dimensional, three-dimensional, and four-dimensional Hamiltonians, which were used in the MCTDH method. Only four degrees of freedom evolve strongly along the 15D minimum energy path: the distance of the center of mass of the molecule to the surface, the dissociative C[Single Bond]H bond distance, the polar orientation of the molecule, and the bending angle between the dissociative C[Single Bond]H bond and the umbrella. A selection of these coordinates is included in each of our models. The polar rotation is found to be important in determining the mode selective behavior of the reaction. Furthermore, our calculations are in good agreement with the finding of Xiang et al. [J. Chem. Phys. 117, 7698 (2002)] in their reduced dimensional calculation that the helicopter motion of the umbrella symmetry axis is less efficient than its cartwheel motion for promoting the reaction. The effect of pre-exciting the bend modes is qualitatively incorrect at higher energies, suggesting the necessity of including additional rotational and vibrational degrees of freedom in the model.

15.
J Neurol Sci ; 294(1-2): 43-50, 2010 Jul 15.
Article En | MEDLINE | ID: mdl-20471037

Skeletal muscle fibrosis is present in the diaphragm of the mdx mouse, a model for Duchenne dystrophy. In both the mouse and human, dystrophic muscle exhibits pronounced increases in NF-kappa B signaling. Various inhibitors of this pathway, such as pyrrolidine dithiocarbamate (PDTC) and ursodeoxycholic acid (UDCA), have been shown to have beneficial effects on dystrophic (mdx) muscle. The present study characterizes the development of fibrosis in the mdx musculature, and determines the fibrolytic efficacy of PDTC and UDCA. The results indicate that collagen accumulation and the expression of fibrogenic (TGF-beta1) and fibrolytic (MMP-9) mediators are dependent on muscle origin in both nondystrophic and mdx mice. Excessive collagen accumulation is observed in the mdx respiratory musculature prior to substantial muscle degeneration and cellular infiltration, and is associated with dystrophic increases in the expression of TGF-beta1 with no corresponding increases in MMP-9 expression. Treatment with PDTC or UDCA did not influence collagen deposition or TGF-beta1 expression in the mdx respiratory musculature. These results indicate that dystrophic increases in collagen are the result of NF-kappaB-independent signaling abnormalities, and that efforts to reduce excessive collagen accumulation will require treatments to more specifically reduce TGF-beta1 signaling or enhance the expression and/or activity of matrix metalloproteases.


Collagen/metabolism , Muscular Dystrophies/metabolism , NF-kappa B/metabolism , Respiratory Muscles/metabolism , Animals , Diaphragm/drug effects , Diaphragm/growth & development , Diaphragm/metabolism , Female , Fibrosis/drug therapy , Fibrosis/metabolism , Male , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Inbred C57BL , Mice, Inbred mdx , Muscle, Skeletal/growth & development , Muscle, Skeletal/metabolism , Muscular Dystrophies/drug therapy , NF-kappa B/antagonists & inhibitors , Pyrrolidines/pharmacology , Respiratory Muscles/drug effects , Respiratory Muscles/growth & development , Respiratory System Agents/pharmacology , Signal Transduction/drug effects , Thiocarbamates/pharmacology , Transforming Growth Factor beta1/metabolism , Ursodeoxycholic Acid/pharmacology
16.
HIV Med ; 11(2): 104-13, 2010 Feb.
Article En | MEDLINE | ID: mdl-19732176

OBJECTIVES: The aim of the study was to determine whether the incidence of first-line treatment discontinuations and their causes changed according to the time of starting highly active antiretroviral therapy (HAART) in an Italian cohort. METHODS: We included in the study patients from the Italian COhort Naïve Antiretrovirals (ICoNA) who initiated HAART when naïve to antiretroviral therapy (ART). The endpoints were discontinuation within the first year of >or= 1 drug in the first HAART regimen for any reason, intolerance/toxicity, poor adherence, immunovirological/clinical failure and simplification. We investigated whether the time of starting HAART (stratified as 'early', 1997-1999; 'intermediate', 2000-2002; 'recent', 2003-2007) was associated with the probability of reaching the endpoints by a survival analysis. RESULTS: Overall, the 1-year probability of discontinuation of >or= 1 drug in the first regimen was 36.1%. The main causes of discontinuation were intolerance/toxicity (696 of 1189 patients; 58.5%) and poor adherence (285 of 1189 patients; 24%). The hazards for all-reason change were comparable according to calendar period [2000-2002, adjusted relative hazard (ARH) 0.82, 95% confidence interval (CI) 0.69-0.98; 2003-2007, ARH 0.94, 95% CI 0.76-1.16, vs. 1997-1999; global P-value = 0.08]. Patients who started HAART during the 'recent' period were less likely to change their initial regimen because of intolerance/toxicity (ARH 0.67, 95% CI 0.51-0.89 vs. 'early' period). Patients who started in the 'intermediate' and 'recent' periods had a higher risk of discontinuation because of simplification (ARH 15.26, 95% CI 3.21-72.45, and ARH 37.97, 95% CI 7.56-190.64, vs. 'early' period, respectively). CONCLUSIONS: It seems important to evaluate reason-specific trends in the incidence of discontinuation in order to better understand the determinants of changes over time. The incidence of discontinuation because of intolerance/toxicity has declined over time while simplification strategies have become more frequent in recent years. Intolerance/toxicity remains the major cause of drug discontinuation.


Anti-HIV Agents/therapeutic use , Antiretroviral Therapy, Highly Active/statistics & numerical data , HIV Infections/drug therapy , Hepatitis C/complications , Medication Adherence/statistics & numerical data , Adult , Age Factors , Anti-HIV Agents/adverse effects , Antiretroviral Therapy, Highly Active/adverse effects , Epidemiologic Methods , Female , HIV Infections/virology , Humans , Italy , Male , Middle Aged , Multivariate Analysis , Pregnancy , Sex Factors , Time Factors , Treatment Failure , Viral Load , Young Adult
17.
Phys Rev E Stat Nonlin Soft Matter Phys ; 80(3 Pt 2): 036312, 2009 Sep.
Article En | MEDLINE | ID: mdl-19905217

In recent years non-normality and transient growths have attracted much interest in fluid mechanics. Here, we investigate these topics with reference to the problem of interfacial instability in superposed Newtonian and non-Newtonian fluid layers. Under the hypothesis of the lubrication theory, we demonstrate the existence of significant transient growths in the parameter space region where the dynamical system is asymptotically stable, and show how they depend on the main physical parameters. In particular, the key role of the density ratio is highlighted.


Models, Theoretical , Nonlinear Dynamics , Rheology/methods , Solutions/chemistry , Computer Simulation
18.
Int J Oral Maxillofac Surg ; 38(12): 1273-8, 2009 Dec.
Article En | MEDLINE | ID: mdl-19781911

This study retrospectively analyses paranasal sinus complications following displacement of oral implants in the maxillary sinus treated according to clinical situation by functional endoscopic sinus surgery (FESS), an intraoral approach, or a combination of both procedures. Over 5 years, 27 patients (13 male; 14 female), aged 27-73 years (mean 53.9 years), underwent treatment for postoperative complications involving the paranasal sinuses following displacement of oral implants in the maxillary sinuses. According to the complication (implant displacement, implant displacement with or without reactive sinusitis and/or with or without associated oro-antral communication), patients were treated with FESS, intraoral approach to the sinus, or FESS associated with an intraoral approach. Follow up lasted for at least 1 year with clinical and radiographic controls. 26 patients recovered completely; one patient underwent re-intervention with FESS and an intraoral approach 2 years after implant removal, due to persistent signs and symptoms of maxillary sinusitis and oro-antral communication. Postoperative recovery after the second procedure was followed by complete recovery. The results demonstrate that a rational choice of surgical protocol for the treatment of complications involving the paranasal sinuses following displacement of implants in the maxillary sinuses may lead to reliable results.


Dental Implants/adverse effects , Foreign Bodies/surgery , Maxillary Sinus , Postoperative Complications/surgery , Adult , Aged , Clinical Protocols , Endoscopy/methods , Female , Follow-Up Studies , Foreign Bodies/etiology , Foreign-Body Migration/etiology , Foreign-Body Migration/surgery , Humans , Male , Maxillary Sinus/surgery , Maxillary Sinusitis/etiology , Maxillary Sinusitis/surgery , Middle Aged , Oroantral Fistula/etiology , Oroantral Fistula/surgery , Osteotomy/methods , Recurrence , Reoperation , Retrospective Studies , Sphenoid Sinus/surgery , Treatment Outcome , Wound Healing/physiology
19.
J Chem Phys ; 130(13): 134302, 2009 Apr 07.
Article En | MEDLINE | ID: mdl-19355727

The variational approach detailed in the previous paper (Paper I) for the treatment of the Renner-Teller effect in linear tetra-atomic molecules including all degrees of freedom and couplings between angular momenta is applied for HCCH(+). The accurate six-dimensional potential energy surfaces of the X (2)Pi(u) electronic state, presented in Paper I is incorporated in the variational treatment in order to obtain all rovibronic levels including the spin-orbit coupling for 1/2 < or = J < or = 7/2 and up to 2600 cm(-1) above the global zero point energy. The "pure" stretching levels are calculated up to 11,000 cm(-1) from the stretching zero point energy. The calculated rovibronic energies are compared with previous theoretical and experimental data. The mean agreement with the zero kinetic energy photoelectron measurements of Tang et al. [J. Chem. Phys. 125, 133201 (2006)] is of 16.7 cm(-1). The Renner-Teller parameters have been determined at nu(trans) = 690.0 cm(-1), epsilon(trans) = 0.30, nu(cis) = 715.0 cm(-1), and epsilon(cis) = -0.063. A detailed analysis of the rovibronic Hund's cases is presented and the rotational structures of some vibronic bands recorded by Yang and Mo [J. Phys. Chem. A 110, 11001 (2006)] are given.

20.
J Chem Phys ; 130(13): 134301, 2009 Apr 07.
Article En | MEDLINE | ID: mdl-19355726

For electronically degenerate states of linear tetra-atomic molecules, a new method is developed for the variational treatment of the Renner-Teller and spin-orbit couplings. The approach takes into account all rotational and vibrational degrees of freedom, the dominant couplings between the corresponding angular momenta as well as the couplings with the electronic and electron spin angular momenta. The complete rovibrational kinetic energy operator is expressed in Jacobi coordinates, where the rovibrational angular momenta J(N) have been replaced by J-L(ez)-S and the spin-orbit coupling has been described by the perturbative term A(SO) x L(ez)S(z). Attention has been paid on the electronic wave functions, which require additional phase for linear tetra-atomic molecules. Our implemented rovibrational basis functions and the integration of the different parts of the total Hamiltonian operator are described. This new variational approach is tested on the electronic ground state X (2)Pi(u) of HCCH(+) for which new six-dimensional potential energy surfaces have been computed using the internally contracted multireference configuration interaction method and the cc-pV5Z basis set. The calculated rovibronic energies and their comparisons with previous theoretical and experimental works are presented in the next paper.

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