Accurate Potential Energy Surfaces Using Atom-Centered Potentials and Minimal High-Level Data

We demonstrate that a Δ-density functional theory (Δ-DFT) approach based on atom-centered potentials (ACPs) represents a computationally inexpensive and accurate method for representing potential energy surfaces (PESs) for the HONO and HFCO molecules and vibrational frequencies derived therefrom. Using as few as 100 CCSD(T)-F12a reference energies, ACPs developed for use with B3LYP/def2-TZVPP are shown to produce PESs for HONO and HFCO with mean absolute errors of 27.7 and 5.8 cm-1, respectively. Application of the multiconfigurational time-dependent Hartree (MCTDH) method with ACP-corrected B3LYP/def2-TZVPP PESs produces vibrational frequencies for cis- and trans-HONO with mean absolute percent errors (MAPEs) of 0.8 and 1.1, compared to 0.8 obtained for the two isomers with CCSD(T)-F12a/cc-pVTZ-F12/MCTDH. For HFCO, the vibrational frequencies obtained using the present (Δ-DFT)/MCTDH approach give a MAPE of 0.1, which is the error obtained with CCSD(T)-F12a/cc-pVTZ-F12/MCTDH. The ACP approach is therefore successful in representing a PES calculated at a high level of theory (CCSD(T)-F12a) and a promising method for the development of a general protocol for the representation of accurate molecular PESs and the calculation of molecular properties from them.

Modulated super-Gaussian laser pulse to populate a dark rovibrational state of acetylene

A pulse-shaping technique in the mid-infrared spectral range based on pulses with a super-Gaussian temporal profile is considered for laser control. We show a realistic and efficient path to the population of a dark rovibrational state in acetylene (C2H2). The laser-induced dynamics in C2H2 are simulated using fully experimental structural parameters. Indeed, the rotation-vibration energy structure, including anharmonicities, is defined by the global spectroscopic Hamiltonian for the ground electronic state of C2H2 built from the extensive high-resolution spectroscopy studies on the molecule, transition dipole moments from intensities, and the effects of the (inelastic) collisions that are parameterized from line broadenings using the relaxation matrix [A. Aerts, J. Vander Auwera, and N. Vaeck, J. Chem. Phys. 154, 144308 (2021)]. The approach, based on an effective Hamiltonian, outperforms today's ab initio computations both in terms of accuracy and computational cost for this class of molecules. With such accuracy, the Hamiltonian permits studying the inner mechanism of theoretical pulse shaping [A. Aerts et al., J. Chem. Phys. 156, 084302 (2022)] for laser quantum control. Here, the generated control pulse presents a number of interferences that take advantage of the control mechanism to populate the dark state. An experimental setup is proposed for in-laboratory investigation.

Intramolecular Vibrational Redistribution in Formic Acid and its Deuterated Forms

The intramolecular vibrational relaxation dynamics of formic acid and its deuterated isotopologues is simulated on the full-dimensional potential energy surface of Richter and Carbonnière [F. Richter and P. Carbonnière, J. Chem. Phys. 148, 064303 (2018)] using the Heidelberg MCTDH package. We focus on couplings with the torsion vibrational modes close to the trans- cis isomerisation coordinate from the dynamics of artificially excited vibrational mode overtones. The C-O stretch bright vibrational mode is coupled to the out-of-the plane torsion mode in HCOOH, where this coupling could be exploited for laser-induced trans-to- cis isomerisation. Strong isotopic effects are observed: deuteration of the hydroxyl group, i.e., in HCOOD and DCOOD, destroys the C-O stretch to torsion mode coupling whereas in DCOOH, little to no effect is observed.

Adaptive Fitting of Potential Energy Surfaces of Small to Medium-Sized Molecules in Sum-of-Product Form: Application to Vibrational Spectroscopy

A semi-automatic sampling and fitting procedure for generating sum-of-product (Born-Oppenheimer) potential energy surfaces based on a high-dimensional model representation is presented. The adaptive sampling procedure and subsequent fitting relies on energies only and can be used for re-fitting existing analytic potential energy surfaces in sum-of-product form or for direct fits from ab initio computa- tions. The method is tested by fitting ground electronic state potential energy surfaces for small to medium sized semi-rigid molecules, i.e., HFCO, HONO, and HCOOH, based upon ab initio computations at the CCSD(T)-F12/cc-pVTZ-F12 or MP2/aug-cc-pVTZ levels of theory. Vibrational eigenstates are computed using block improved relaxation in the Heidelberg MCTDH package and compared to available experimental and theoretical data. The new potential energy surfaces are compared to the best ones currently available for these molecules, in terms of accuracy, including of resulting vibrational states, required numbers of sampling points, and number of fitting parameters. The present procedure leads to compact expansions and scales well with the number of dimensions for simple potentials such as single or double wells.

Laser control of a dark vibrational state of acetylene in the gas phase—Fourier transform pulse shaping constraints and effects of decoherence

We propose a methodology to tackle the laser control of a non-stationary dark ro-vibrational state of acetylene (C2H2), given realistic experimental limitations in the 7.7 μm (1300 cm−1) region. Simulations are performed using the Lindblad master equation, where the so-called Lindblad parameters are used to describe the effect of the environment in the dilute gas phase. A phenomenological representation of the parameters is used, and they are extracted from high-resolution spectroscopy line broadening data. An effective Hamiltonian is used for the description of the system down to the rotational level close to experimental accuracy. The quality of both the Hamiltonian and Lindblad parameters is assessed by a comparison of a calculated infrared spectrum with the available experimental data. A single shaped laser pulse is used to perform the control, where elements of optics and pulse shaping using masks are introduced with emphasis on experimental limitations. The optimization procedure, based on gradients, explicitly takes into account the experimental constraints. Control performances are reported for shaping masks of increasing complexity. Although modest performances are obtained, mainly due to the strong pulse shaping constraints, we gain insights into the control mechanism. This work is the first step toward the conception of a realistic experiment that will allow for population characterization and manipulation of a non-stationary vibrational “dark” state. Effects of the collisions on the laser control in the dilute gas phase, leading to decoherence in the molecular system, are clearly shown.

Lindblad parameters from high resolution spectroscopy to describe collision-induced rovibrational decoherence in the gas phase-Application to acetylene

Within the framework of the Lindblad master equation, we propose a general methodology to describe the effects of the environment on a system in the dilute gas phase. The phenomenological parameters characterizing the transitions between rovibrational states of the system induced by collisions can be extracted from experimental transition kinetic constants, relying on energy gap fitting laws. As the availability of these kinds of experimental data can be limited, this work relied on experimental line broadening coefficients, however still using energy gap fitting laws. The 3 μm infrared spectral range of acetylene was chosen to illustrate the proposed approach. The method shows fair agreement with available experimental data while being computationally inexpensive. The results are discussed in the context of state laser quantum control.

A revised nuclear quadrupole moment for aluminum: Theoretical nuclear quadrupole coupling constants of aluminum compounds

The nuclear quadrupole moment of aluminum (²⁷Al) has been re-evaluated by determining the electric field gradients at this nucleus for AlF and AlCl using the coupled cluster method with single, double, and perturbative triple excitations [CCSD(T)]/aug-cc-pwCVXZ (X = T and Q) accounting for both vibrational averaging and core-core/core-valence electron correlation and then comparing to the experimentally measured nuclear quadrupole coupling constants (NQCCs). The new recommended value is Q(²⁷Al) = 148.2 ± 0.5 mb, which can be compared to the previous value of 146.6 ± 1 mb. Using the new value of the nuclear quadrupole moment, the accuracy is assessed for several computational approaches [i.e., Hartree-Fock, Møller-Plesset perturbation theory to the second order, quadratic configuration interaction with single and double excitations, CCSD, CCSD(T), and density functional theory (DFT) with the B3LYP, PBE0, and M06-2X functionals] and basis sets (the aug-cc-pVXZ and aug-cc-pwCVXZ families) for determining the nuclear quadruple coupling constants for AlCN, AlNC, AlSH, AlOH, and AlCCH, where experimental measurements are available. From the results at equilibrium geometries of the polyatomic molecules, it has been determined that (i) the CCSD(T)/aug-cc-pwCVXZ approach is needed to obtain results within 4% of the experimental measurements, (ii) typical DFT values are only within 10%-15% of the experimental measurements, and (iii) the aug-cc-pVXZ family of basis sets is not recommended for computing the electric field gradients at aluminum. The present results also suggest that the NQCC for AlOH should be remeasured. Using the recommended CCSD(T)/aug-cc-pwCVXZ approach, the equilibrium geometries and corresponding NQCCs for AlCH₃ and AlCCCN were determined, and the NQCCs are in excellent agreement with previously reported experimental values.

Oxygen–iron interaction in liquid lead–bismuth eutectic alloy

Iron released in steel corrosion is a key impurity in reactions with dissolved oxygen in liquid lead–bismuth eutectic alloys.

Electrophysiological registration of phonological perception in the subthalamic nucleus of patients with Parkinson's Disease

Phonological processing is usually associated with the activation of cortical areas, especially in the left cerebral hemisphere. This study examined if phonologically elicited evoked potentials can be recorded directly from the subthalamic nucleus in patients with Parkinson's Disease (PD). Seven PD patients who had undergone implantation of deep brain electrodes for the stimulation of the subthalamic nucleus were included. Local field potentials were recorded in a pre-attentive auditory phonological task, an attentive auditory phonological discrimination task, and a word recognition task. Auditory evoked potentials related to phonological, but not lexical processing, could be demonstrated in the subthalamic nucleus for all three tasks. Only minor changes were found after levodopa administration. This study demonstrates that the subthalamic nucleus is involved in early phonological perception, which puts the subthalamic nucleus in a position to modify phonological perception in a larger cortico-subcortical network.

Antihypertensive effectiveness of aliskiren for the 'real-world' management of hypertension: multilevel modelling of 180-day blood pressure outcomes (the Belgian DRIVER Study)

AIMS

The 'DRIVER' study was designed to investigate the 'real-world' effectiveness of aliskiren-based treatment of hypertension. This article reports the 180-day blood pressure (BP) outcomes, and the multilevel (physician- and patient-level) determinants thereof.

METHODS AND RESULTS

DRIVER was a prospective, observational, open-label, multi-centre, pharmaco-epidemiologic study of hypertensive patients treated with aliskiren in whom prior treatment failed or was not tolerated. 2070 patients (enrolled by 426 physicians) were enrolled; 1695 patients (81.9%) completed the 180-day aliskiren treatment period. Mean patient age was 64.2 ± 12.1 years; 53.7% were men, 25.3% diabetic and 40.7% had a high or very high cardiovascular (CV) risk. At 180 days, the mean ± SD reductions in systolic and diastolic BP were -22.9 ± 16.7 mmHg and -10.5 ± 10.9 mmHg respectively (both p < .001). 2007 and 2009 guideline-defined BP control was achieved in 36.4% and 56.3% of patients, respectively (both p < .001). 64.2% of eligible patients had a reduction in CV risk (p < .001). A physician-level class effect was responsible for 22.8% and 28.1% of variability in systolic and diastolic BP, respectively, for 20.1% of variability in BP control, and for 16.1% of variability in the reduction of CV risk. Both patient- (e.g. adherence) and physician-related factors (e.g. age and knowledge) were significant in profiling best response to treatment with aliskiren. Adverse events reported in this article were consistent with the aliskiren scientific leaflet.

CONCLUSION

Aliskiren is safe and effective in reducing BP, improving BP control and reducing global CV risk in a 'real-world' setting and for patients in whom prior treatment failed or was not tolerated. Optimising treatment adherence and strategic medical education may be ways of improving BP outcomes in patients with hypertension.

Tuberculosis and tuberculosis control in European prisons

OBJECTIVE

Correctional facilities have often been cited as reservoirs for tuberculosis (TB), presenting a potential threat to the general population. Although correctional facilities are recognised as ideal settings for interventions, little is known about the TB epidemiology within them. The purpose of our survey was to collect data on TB in prisons of the WHO European Region and on existing control measures.

DESIGN

A questionnaire was sent to 52 EuroTB correspondents asking for 2002 data on the total number of inmates, number of prisoners with TB, resistance rates, screening strategies, monitoring and responsibilities.

RESULTS

Twenty-two (42.3%) countries completed the questionnaire. The median TB notification rate was 232 per 100,000 inmates (0-17,808). Prisoners had up to 83.6 times more TB than civilians. The majority (90.9%) of the participating countries reported performing active screening for TB on entry into prison, with a median detection rate of 393/100,000 (42-2362). Of the respondent countries, 81.8% claimed to perform contact investigations and 86.4% to house infectious TB patients separately.

CONCLUSION

Although response to this survey was only 42.3% and might be biased by a country's engagement in TB control in prisons, the results highlight the vulnerability of prisoners to TB and emphasise the need for adequate case-finding and containment strategies in prison.

The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

Fast separations on monolithic silica columns: method transfer, robustness and column ageing for some case studies

Six separation methods, developed on conventional silica high performance liquid chromatography (HPLC) columns were transferred to monolithic silica columns of 5 and 10 cm length. The transferred methods include the separation of an alkylbenzene mixture, the separations of drugs from their impurities (nimesulide, tetracycline, phenoxymethylpenicillin and erythromycin) and the separation of a green tea extract. The transfer of the first three methods was successful while for the latter three it was not. Increasing the flow rate up to 9 ml/min (where possible) inversely decreased the analysis time of the successfully transferred methods to 48 s (alkylbenzene mixture) 1.8 min (nimesulide mixture) and 3 min (tetracycline mixture) while still reasonable well separated peaks were obtained. The robustness and repeatability of the transferred and accelerated separations was found to be acceptable. Despite the use of flow rates up to 9 ml/min and frequent mobile phase changes with pH values varying from 3.5 to 7, the column performance was found to be rather constant and the column ageing to be minimal.

Chronic radiodermatitis following percutaneous coronary interventions: a report of two cases

We describe two patients in whom chronic radiodermatitis with therapy-resistant ulceration of the right scapular region developed, following percutaneous coronary intervention with fluoroscopic imaging. Contrary to most reported cases in the literature, which involve numerous cardiac catheterization procedures, in both patients described here the total radiation dose was given during two successive procedures, involving difficult and prolonged coronary intervention with stent implantation. In both cases, local treatment of the ulcerative lesions was insufficient, necessitating excision of the radiodermatitis area and replacement with a skin graft, with good therapeutic result. The incidence of radiodermatitis after percutaneous coronary interventions is rising with the increasing number and complexity of these procedures. The main risk factor is a long duration of fluoroscopy using the same incidence. The skin lesions encompass a wide spectrum, ranging from erythema, telangiectasia, atrophy, hyperpigmentation and hypopigmentation to necrosis, chronic ulceration and squamous cell carcinoma. The lesions can appear from 15 days to 10 years after the procedure. To prevent radiation-induced injury, the radiation dose has to be limited and monitored. Also, careful inspection of the skin at the site of exposure is necessary and the radiographic beam has to be restricted to the smallest field size. A good clinical follow-up at regular intervals is important after long and complicated procedures.

Pulmonary tuberculosis in prisons of the ex-USSR state Georgia: results of a nation-wide prevalence survey among sentenced inmates

SETTING

The penitentiary system of the ex-USSR state of Georgia.

OBJECTIVES

To measure the prevalence of active pulmonary tuberculosis and drug-resistant disease among prisoners. To identify factors associated with active tuberculosis and multidrug resistance (MDR).

DESIGN

A comprehensive multiphasic screening survey for tuberculosis.

RESULTS

The prevalence of smear- or culture-positive tuberculosis was 5995 per 100,000 prisoners (n = 448 cases among 7473 inmates). Of all the strains, 215 (77.9%) were resistant to at least one drug and 37 (13.0%) were MDR. Independent risk markers associated smear- or culture-positive tuberculosis with included prison stay of 2 years or more, body mass index <20 kg/m2, accommodation in a large size prison, previous anti-tuberculosis treatment, cough of 2 weeks or more and loss of appetite. Risk markers associated with MDR were a prison stay of less than 2 years and being over 25 years of age.

CONCLUSIONS

In Georgia, the excess risk for tuberculosis among prisoners is unprecedented, suggesting that prisons represent a significant reservoir of tuberculosis. Only a comprehensive strategy for tuberculosis control in prisons, including prison reform, control of anti-tuberculosis drugs, and prompt and efficient diagnosis and treatment of patients can have an impact on the tuberculosis burden in the prison system.

Venous pooling during nitrate-stimulated tilt testing in patients with vasovagal syncope

AIMS

To investigate the importance of venous pooling and variation in venous tone during nitrate-stimulated tilt testing in patients.

METHODS

Ten patients with a history of vasovagal syncope underwent an upright tilt test after an injection of 99mTc-labelled albumin. A gamma camera was positioned at the level of the lower legs. The patients were tilted to 90 degrees for 30 min or until symptoms developed. In those subjects who did not show any symptoms before the end of the 30-min period, isosorbide dinitrate (ISDN) 5 mg was given sublingually and the test was prolonged for a maximum of 15 min.

RESULTS

Nine of 10 patients needed nitrate stimulation to develop symptoms, and one patient remained symptom free following ISDN administration. Measurement of radioactivity revealed no significant increase in calf volume after nitrate stimulation (the mean volume increase was 77% before ISDN stimulation and a further 0.9% afterwards).

CONCLUSIONS

The higher sensitivity for vasovagal syncope during upright tilt testing after administration of sublingual ISDN is not due to an increase in venous pooling in the lower extremities.

Sublingual nitrates during head-up tilt testing for the diagnosis of vasovagal syncope

Pharmacologic stimulation during head-up tilt test (HUT) is used to increase the diagnostic yield of the test to detect vasovagal syncope. Reported lack of specificity of stimulation with intravenous isoproterenol has made a pharmacologic alternative desirable. Because nitrates are known to cause syncope of a vasovagal origin, we administered sublingual nitrates after classic tilt test in 32 patients with a history of typical vasovagal syncope and 20 healthy volunteers to assess the sensitivity, specificity, and accuracy of this new HUT technique. During the classic HUT four (13%) patients had syncope; after administration of sublingual nitrates, this number increased to 28 (87%). In the control group no subject had syncope during classic HUT, whereas during nitrate administration six (30%) had syncope. Sublingual nitrate stimulated HUT revealed a maximum accuracy of 83% at a cutoff point of 11 minutes, giving a sensitivity of 81% and specificity of 85%. Sublingual nitrate administration increased the accuracy of HUT in diagnosing vasovagal syncope in patients with a history of typical vasovagal syncope.

[Treatment of menopausal hot flushes with a nonhormonal medication, veralipride]

The value of veralipride in menopausal disorders is no longer questionable and has been documented by a number of studies. The purpose of this paper is to study the clinical effectiveness and to look for the biological consequences of three months therapy with veralipride. To achieve this, a thorough biological study (hematology, glucids, lipids, hepatic and renal function) was done in 21 patients with a menopausal syndrome before and after taking veralipride for three months. Clinical effectiveness was excellent with 80% satisfactory results. No signs of intolerance or adverse side-effects were seen. We recorded no significant changes in biological parameters. No disturbances of renal or hepatic function were detected, either in individual assessments or in the overall statistical analysis of the study group. Because it is well tolerated, effective, and devoid of adverse metabolic side-effects, we conclude that veralipride is the best non-hormonal treatment for menopausal disorders presently available.