X-ray crystallographic analysis of the antiferromagnetic low-temperature phase of galvinoxyl: investigating magnetic duality in organic radicals

Galvinoxyl, as one of the most extensively studied organic stable free radicals, exhibits a notable phase transition from a high-temperature (HT) phase with a ferromagnetic (FM) intermolecular interaction to a low-temperature (LT) phase with an antiferromagnetic (AFM) coupling at 85 K. Despite significant research efforts, the crystal structure of the AFM LT phase has remained elusive. This study successfully elucidates the crystal structure of the LT phase, which belongs to the P1̄ space group. The crystal structure of the LT phase is found to consist of a distorted dimer, wherein the distortion arises from the formation of short intermolecular distances between anti-node carbons in the singly-occupied molecular orbital (SOMO). Starting from the structure of the LT phase, wave function calculations show that the AFM coupling 2J/kB varies significantly from -1069 K to -54 K due to a parallel shift of the molecular planes within the dimer.

Vitamin Status of Obese Tunisian adults before and after Sleeve Gastrectomy

INTRODUCTION

The worldwide obesity epidemic continues unabated. Obesity and its associated health risks are considered as the major causes of morbidity and mortality. Currently, bariatric surgery is the most effective treatment for people with severe obesity resulting in sustainable weight loss and a reduced risk for co-morbidities. Sleeve gastrectomy is the most common bariatric procedure undertaken in Tunisia.

AIM

we aim to evaluate the vitamin status of the obese patients before and after sleeve gastrectomy.

METHODS

Thirty obese patients undergoing sleeve gastrectomy, were recruited from Obesity unit. In this study. A biological assessment was performed pre-operatively and controlled 6 months following the sleeve gastrectomy including: calcemia, parathyroid hormone (PTH), albuminemia and dosage of vitamin D, vitamin B9 and vitamin B12.

RESULTS

Six months post sleeve gastrectomy, vitamin deficiencies were more prevalent: the mean level of vitamin B9, vitamin B12 and vitamin D respectively, has decreased from 5.03±3.28 ng / ml to 2.71±1.52 ng / ml, from 348.06±158.92 pg/ml to 264.62±119.77 pg/ml and from 17.18±11.45 ng/ml to 11.69±8.22 ng/ml, with a statistically significant difference (p=0.008, p=0.01 and p=0.012). Sleeve gastrectomy has proven to be an effective weight loss treatment. However, nutritional deficiencies have worsened during postoperative period.

CONCLUSION

This study highlights the importance of early identification, appropriate treatment and prophylactic micronutrient supplementation.

Development and validation of anthropometric predictive equations that estimate the total body water and fat-free mass in Tunisian adults

OBJECTIVE

To develop and validate equations that estimate total body water (TBW) and fat-free mass (FFM) in adults using anthropometric measurements.

METHODS

A cross-sectional study was conducted among 178 adults (77 men and 101 women; aged 18-59 years). Participants were distributed by sex and age groups, and then randomly assigned to equal two groups; the development (n = 89) and the validation (n = 89). The anthropometric measurements included height and weight. The deuterium dilution technique (DDT) estimated TBW and FFM. Linear regression models were used with the TBW and FFM as the dependent variable, and height and weight as the independent variables. Cross-validation was performed by Bland and Altman plot, and the new anthropometric equations were developed.

RESULTS

In the validation sample, the developed equations had high R2 of 94.4 for both TBW and FFM in all age groups, and low standard errors (RMSE: 1.80 kg for TBW and 2.44 kg for FFM). The pure error was 2.03 for the TBW equation and 2.71 for the FFM equation. The Bland-Altman plot illustrated the good level of concordance between the TBW and FFM predicted by the new equations as determined by DDT. The following developed equations showed a better agreement with the DDT: [Formula: see text]; [Formula: see text].

CONCLUSION

In this study, we developed and validated prediction equations for the estimation of TBW and FFM from DDT in healthy adult Tunisian population. The newly anthropometric prediction equations seem to be the most accurate for Tunisian adult.

Modifications of Tanabe-Sugano d6 Diagram Induced by Radical Ligand Field: Ab Initio Inspection of a Fe(II)-Verdazyl Molecular Complex

Quantum entanglement between the spin states of a metal center and radical ligands is suggested in an iron(II) [Fe(dipyvd)₂]²⁺ compound (dipyvd = 1-isopropyl-3,5-dipyridil-6-oxoverdazyl). Wave function ab initio (Difference Dedicated Configuration Interaction, DDCI) inspections were carried out to stress the versatility of local spin states. We named this phenomenon excited state spinmerism, in reference to our previous work (see Roseiro et al., ChemPhysChem 2022, e202200478) where we introduced the concept of spinmerism as an extension of mesomerism to spin degrees of freedom. The construction of localized molecular orbitals allows for a reading of the wave functions and projections onto the local spin states. The low-energy spectrum is well-depicted by a Heisenberg picture. A 60 cm^-1 ferromagnetic interaction is calculated between the radical ligands with the S_total = 0 and 1 states largely dominated by a local low-spin S_Fe = 0. In contrast, the higher-lying S_total = 2 states are superpositions of the local S_Fe = 1 (17%, 62%) and S_Fe = 2 (72%, 21%) spin states. Such mixing extends the traditional picture of a high-field d⁶ Tanabe-Sugano diagram. Even in the absence of spin-orbit coupling, the avoided crossing between different local spin states is triggered by the field generated by radical ligands. This puzzling scenario emerges from versatile local spin states in compounds which extend the traditional views in molecular magnetism.

Is fat taste associated with diet quality? A cross-sectional study conducted among Tunisian adults

The Tunisian population has experienced a nutrition transition with an increase in the incidence of obesity. As obesity has been associated with a poor orosensory detection of fat. We hypothesized that poor fat detection could be a driver of poor diet quality. This study examined the association between linoleic acid (LA) detection and adherence to a healthy diet among adult participants. A total of 104 LA taster participants were recruited for this study. Dietary assessment was conducted using the 24 h dietary recall method. Diet quality was assessed by determining the Mediterranean diet (MD) score and Health diet indicator (HDI). The relationship between diet quality and log LA detection threshold was done using adjusted linear regression for age, sex, and daily energy intake (only in the fully adjusted model). The predictive margins model (interaction: anthropometric status x LA threshold) was used to assess the difference between non-obese and subjects with obesity adherence to MD across LA detection values. We have observed that the increase in the concentration of linoleic acid detection by 1 log(mmol/L) is associated with an increase of HDI score by 0.12-point [95% CI: 0.02-0.21] and a decrease of the MD score by -0.14-point [-0.25 to -0.03] in the partially adjusted model. However, only the MD score remained negatively associated with LA detection threshold in the fully adjusted model. The subjects with obesity adherence to the Mediterranean diet was lower than subjects with normal weight for LA concentration less than 0 log(mmol/L). The present study suggests that poor orosensory detection of dietary lipids might be a driver for worsening diet quality. Hence, These subjects might be at risk for obesity and, consequently, exposed cumulatively to the harmful effects of excess adiposity and an unhealthy diet.

Difficulty of the evaluation of the barrier height of an open-shell transition state between closed shell minima: The case of small C4n rings

C_4n cyclacenes exhibit strong bond-alternation in their equilibrium geometry. In the two equivalent geometries, the system keeps an essentially closed-shell character. The two energy minima are separated by a transition state suppressing the bond-alternation, where the wave function is strongly diradical. This paper discusses the physical factors involved in this energy difference and possible evaluations of the barrier height. The barrier given as the energy difference between the restricted density functional theory (DFT)/B3LYP for the equilibrium and the broken symmetry DFT/B3LYP of the transition state is either negative or small, in contradiction with the most reliable Wave Function Theory calculations. The minimal (two electrons in two molecular orbitals) Complete Active Space self-consistent field (CASSCF) overestimates the barrier, and the subsequent second-order perturbation cancels it. Due to the collective character of the spin-polarization effect, it is necessary to perform a full π CASSCF + second-order perturbation to reach a reasonable value of the barrier, but this type of treatment cannot be applied to large molecules. DFT procedures treating on an equal foot the closed-shell and open-shell geometries have been explored, such as Mixed-Reference Spin-Flip Time-dependent-DFT and a new spin-decontamination proposal, namely, DFT-dressed configuration interaction, but the results still depend on the density functional. M06-2X without or with spin-decontamination gives the best agreement with the accurate wave function results.

The Role of Dietary Intake in Type 2 Diabetes Mellitus: Importance of Macro and Micronutrients in Glucose Homeostasis

The prevalence of Type 2 diabetes (T2D) is increasing worldwide. Genetics and lifestyle, especially diet, are contributing factors. Analyses of macro- and micronutrient intake across global populations may help to explain their impact on glucose homeostasis and disease development. To this end, 420 Tunisians were enrolled in a prospective cross-sectional study of daily food consumption. Various data were collected and blood samples were drawn for biochemical assay. A 24-h recall questionnaire was obtained from participants to evaluate dietary intake. Statistical analyses were conducted using Nutrilog and R software. Biochemical analyses stratified the studied population (n = 371) into three groups: diabetics (n = 106), prediabetics (n = 192) and controls (n = 73); 49 subjects were excluded. Our results showed that Tunisians had hypercaloric diets high in carbohydrates and fat with variability in the levels of some vitamins and minerals, including riboflavin and niacin, that were statistically different among groups. The lower intake of vitamin D was associated with a greater risk of T2D. Higher vitamin A and sodium intake were associated with poor glucose homeostasis, although protein intake may improve it. In perspective, nutrigenomic studies can provide insight into problematic diets and poor eating habits and offer opportunities to analyze the effects of behavioral changes that can mitigate T2D development and progression.

Combining Open-Shell Verdazyl Environment and Co(II) Spin-Crossover: Spinmerism in Cobalt Oxoverdazyl Compound

The spin states of a Co(II) oxoverdazyl compound are investigated by means of wavefunction-based calculations. Within a ca. 233 K energy window, the ground state and excited states display a structure-sensitive admixture of low-spin SM = 1/2 in a dominant high-spin SM = 3/2 Co(II) ion as read from localized molecular orbitals. This puzzling spins zoology that results from the coupling between open-shell radical ligands and a spin-crossover metal ion gives rise to this unusual scenario which extends the views in molecular magnetism. In agreement with experimental observation, the low-energy spectroscopy is very sensitive to deformations of the coordination sphere, and a growing admixture of Co(II) low-spin is evidenced from the calculations. In analogy with mesomerism that accounts for charge delocalization, entanglement combines different local spin states to generate a given total spin multiplicity, a spinmerism phenomenon.

Model protein excited states: MRCI calculations with large active spaces vs CC2 method

Benchmarking calculations on excited states of models of phenylalanine protein chains are presented to assess the ability of alternative methods to the standard and most commonly used multiconfigurational wave function-based method, the complete active space self-consistent field (CASSCF), in recovering the non-dynamical correlation for systems that become not affordable by the CASSCF. The exploration of larger active spaces beyond the CASSCF limit is benchmarked through three strategies based on the reduction in the number of determinants: the restricted active space self-consistent field, the generalized active space self-consistent field (GASSCF), and the occupation-restricted multiple active space (ORMAS) schemes. The remaining dynamic correlation effects are then added by the complete active space second-order perturbation theory and by the multireference difference dedicated configuration interaction methods. In parallel, the approximate second-order coupled cluster (CC2), already proven to be successful for small building blocks of model proteins in one of our previous works [Ben Amor et al., J. Chem. Phys. 148, 184105 (2018)], is investigated to assess its performances for larger systems. Among the different alternative strategies to CASSCF, our results highlight the greatest efficiency of the GASSCF and ORMAS schemes in the systematic reduction of the configuration interaction expansion without loss of accuracy in both nature and excitation energies of both singlet ππ^* and nπ^* _CO excited states with respect to the equivalent CASSCF calculations. Guidelines for an optimum applicability of this scheme to systems requiring active spaces beyond the complete active space limit are then proposed. Finally, the extension of the CC2 method to such large systems without loss of accuracy is demonstrated, highlighting the great potential of this method to treat accurately excited states, mainly single reference, of very large systems.

Assessment of the Nutritional Status of Hospitalized Type 2 Diabetic Patients

Objectives

The aim of our work was to assess the nutritional status and to determine the prevalence of undernutrition in type 2 diabetic patients hospitalized in a center specializing in Nutrition, Diabetology and Metabolic Diseases.

Methods

This is a descriptive cross-sectional prospective study, which involved 40 type 2 diabetic patients, aged 18 and over, hospitalized in department A of the National Institute of Nutrition and Food Technology. The assessment of nutritional status was carried out using clinical means (kinetics of weight loss, a dietary survey, anthropometric measurements, impedancemetry, Nutritional Risk Score 2002 for those under 70 years old and the Mini Nutritional Assessment from 70 years old) and biological (albuminemia). The positive diagnosis of malnutrition was selected according to the criteria of the High Authority of Health of 2019 for adults under 70 years, and of 2007 for elderly subjects.

Results

The mean age was 59.6 ± 11.59 years old. The average duration of diabetes was 10.83 ± 8.03 years. The mean level of glycated hemoglobin was 11.03 ± 1.97% and the Body Mass Index was 28.88 kg/m² with extremes ranging from 14.6 to 40.9 kg/m². Weight loss was noted in 48% of patients. Calorie intake was low in 30% of the patients. Protein and mono-unsaturated fatty acid low intake was noted in respectively 28% and 70% of patients. More than half of patients had deficiency in vitamin C, D, B12 and B9 as well as in zinc, calcium, magnesium and cooper. Iron and vitamin B12 low intake was more prevalent in patients with malnutrition (p = 0.043 and p = 0.003 respectively). The mean serum albumin was 37.58 ± 2.93 g/l with ranges ranging from 27.2 to 43.8 g/l. Malnutrition was diagnosed in 25% of patients and in half of the cases, it was severe.

Conclusions

Patients with type 2 diabetes mellitus are at high risk of malnutrition with a high prevalence of dietary intakes deficiencies.

Funding Sources

1. HAS. Diagnostic de la dénutrition de l'enfant et l'adulte. Service de bonnes pratiques professionnelles, 2019. 2. HAS. Stratégie de prise en charge en cas de dénutrition protéino-énergétique chez la personne âgée. Service des recommandations professionnelles. Avril 2007. 3. Anses. Actualisation des repères du PNNS: élaboration des références nutritionnelles. Saisie n° 2012-SA-0186. Avis de l'Anses. Rapport d'expertise collective. Décembre 2016.

Impact of sleeve gastrectomy on abnormalities in carbohydrate tolerance in obese adult

INTRODUCTION

Facing the repeated failures of the medical management of obesity, bariatric surgery offers a promising therapeutic option in terms of achieving weight loss and metabolic benefits.

AIM

To evaluate the impact of sleeve gastrectomy on the carbohydrate profile of a group of obese subjects.

METHODS

It is a prospective study including 40 obese patients (7 Men and 33 Women) who underwent sleeve gastrectomy between 2016 and 2018. Clinical and biological parameters were collected before the intervention, at six months and one year after. Insulin resistance was defined by a HOMA-IR index ≥2.4. Remission of diabetes was determined using the American Society for Metabolic and Bariatric Surgery's (ASMBS) criteria.

RESULTS

The mean patients' age was 34.65 ± 8.17 years. The mean body mass index (BMI) was 50.23 ± 8.3 kg/m². One year after sleeve gastrectomy, the frequency of insulin resistance, decreased from 89% to 4% (p<0.05). The evolution of carbohydrate tolerance abnormalities was marked by the diabetes and prediabetes remission in 75% and 100% of cases, respectively. The mean excess weight loss was 55.8% at 12 months.

CONCLUSION

These results have expanded our knowledge of the short-term sleeve gastrectomy's effectiveness on the carbohydrate profile of obese subjects. However, it would be interesting to check the durability of this metabolic benefit in the medium and long term.

Impact of nutrients and Mediterranean diet on the occurrence of gestational diabetes

Background: The Mediterranean diet (MedDiet) is a dietary pattern effective in terms of prevention of many diseases such as gestational diabetes mellitus (GDM). Recently, many studies have paid attention to nutritional factors during pregnancy as a modifiable contributor to GDM risk.

Objective: to investigate associations of nutrients intakes and MedDiet pattern of eating with risk of GDM.

Subjects/Methods: This study conducted on N = 120; Pregnant women with GDM (n = 60) and without controls (n = 60). The dietary habits were assessed by a dietary history method and a validated food frequency questionnaire. We calculated a MedDiet score which measures the degree of adherence to a Med Diet.

Result: A low Med Diet score was found in pregnant women with and without gestational diabetes in 46.7% and 38.8% of cases, respectively, with no significant difference. Our data showed that the higher the adherence score to the MedDiet, the lower the fasting blood glucose level and the plasma glucose 2 h post load. These findings concerned the two groups studied (P < 10⁻³). We also noted that controls had a significantly higher intake of legumes, vegetables and fish. Monounsaturated fatty acids and saturated fatty acids consumption was significantly higher in the control group (2.3 ± 0.8 vs 1.7 ± 0.7, P < 10⁻³). GDM subjects consumed significantly more dairy products and cereals (P < 10⁻³). After adjustment for confounders, no nutrient was associated with the risk of developing gestational diabetes except vitamin D intake (OR 0.29 [0.15−0.54], P < 10⁻³) which had a protective effect.

Conclusion: Our study underlines the importance of adequate vitamin D intake during pregnancy and suggests that the MedDiet may reduce the incidence of gestational diabetes.

The objective clinical evaluation in multiple stations in nutrition : Docrimological analysis

CONTEXT

As part of its pedagogical reform, the Faculty of Medicine of Tunis integrated since 1998 the objective clinical evaluation in multiple stations (ECOSM), as sanctioning evaluation at the end of the internships. However, this method has never been evaluated in nutrition.

OBJECTIVE

Carry out a docimological analysis of the ECOSM in nutrition intended for students of the 2nd year of the Second Cycle of Medical Studies (DCEM 2).

METHODS

This was a transversal descriptive prospective study on the ECOSM for sanctioning purposes, students of DCEM 2 having carried out an internship at the National Institute of Nutrition in Tunis during the academic year 2017- 2018.

RESULTS

The general average of the ECOSM for the population studied was 13.92 ± 1.45 out of 20. Half of the stations were of acceptable difficulty. More than a third of the questions (37%) had good or excellent discrimination. For all the stations combined, the average Cronbach's alpha coefficient was 0.62, indicating an unacceptable internal homogeneity with great heterogeneity. Likewise, the Cronbach's alpha coefficients calculated for all stations and all questions were strictly less than 0.7. The flattening coefficient was negative, equal to -0.946, and the distribution curve was platykurtic.

CONCLUSIONS

At the end of this work, we recommend making students and teachers particularly aware of the importance of evaluating the various objectives during the internship before the ECOSM test in order to fill in the gaps and ensure that the internship objectives are met.

Eating disorders in type 1 diabetic adolescent

BACKGROUND

Adolescents with type1 diabetes appear to be at greater risk for developing eating disorders (ED) which are often associated with impaired metabolic control of diabetes.

AIM

To estimate the prevalence of ED in a population of adolescents with type 1 diabetes (T1D) and to identify risk factors associated with this disorder in order to propose preventive measures.

METHODS

A cross-sectional, population-based study involved 102 adolescents with type 1 diabetes, aged 11-18 years, recruited from the National Institute of Nutrition in Tunis, Tunisia over a period of one-year January 2017-January 2018.

RESULTS

The prevalence of ED was 33.3%. It was significantly higher among girls (46.2% vs 20%, p = 0.005). Unspecified ED were predominant with a prevalence of 29.4%. Independent factors associated with ED were female sex, abdominal obesity and quality of life. The risk of developing ED was multiplied by 3.5 for women (adjusted OR = 3.5 and CI95% [1.4-8.6]) and by 5.6 for patients with abdominal obesity (Adjusted OR = 5.6 and CI95% [1.5-20.4]). Impaired quality of life and specifically anxiety about diabetes increased significantly the risk of developing ED in our patients. However, we didn't find significant association between ED and age, family characteristics, duration of diabetes, metabolic balance, treatment and complications of diabetes.

CONCLUSION

We concluded that ED should be always suspected in adolescents with T1D especially in girls. Unspecified ED are more common in this group of patients. Treatment of diabetes requires a multidisciplinary care approach including diabetologist, dietician and psychiatrist in order to promote healthy eating and to improve quality of life of adolescents with T1D.

Spin polarization as an electronic cooperative effect

Taking as an example the simple CH₃ radical, this work demonstrates the cooperative character of the spin-polarization phenomenon of the closed-shell core in free radicals. Spin polarization of CH σ bonds is not additive here, as spin polarization of one bond enhances that of the next bond. This cooperativity is demonstrated by a series of configuration interaction calculations converging to the full valence limit and is rationalized by analytic developments. The same phenomenon is shown to take place in those diradicals where spin polarization plays a major role, as illustrated in square planar carbo-cyclobutadiene C₁₂H₄. The treatment of cooperativity represents a challenge for usual post-Hatree-Fock methods.

Prevalence of malnutrition for elderly hemodialysis patients

INTRODUCTION

The prevalence of the terminal chronic renal failure treated by hemodialysis is rising steadily especially for the elderly. Its evolution is fraught with complications including protein-energy malnutrition. The aim of this study was to evaluate the predominance of protein-energy malnutrition among elderly hemodialysis patients.

METHODS

This cross-sectional descriptive study included 40 elderly hemodialysis patients recruited at the M8 nephrology department of Charles Nicolle Hospital in Tunis. All patients went through a clinical examination, a biological assessment, a dietary survey based on food registration for 3 consecutive days and the calculation of nutritional risk scores (MNA and GNRI).

RESULTS

The Average  of hemodialysis was of 7 ± 3.8 years. The average energy intake of the patients was 25.3 ± 12.3 kcal / kg of ideal weight per day. The weight evolution during the last 6 months preceding the study was marked by a weight loss exceeding the 10 % in 12 % of the cases. A BMI less than 21 kg / m² was noted in 73.7 % of the women and 47.6 % of the men. The brachial circumference was less than 22 cm in 36.8 % of the women and 23.6 % of the men. One-third (32.5 %) of the study population had a calf circumference that is less than 31 cm. Most patients (67.5 %) had hypoalbuminaemia. The predominance of malnutrition according to the 2007 HAS criteria was 71% among hemodialysis patients. The majority of women (78.9 %) and 57.1 % of men had GNRI less than or equal to 98.

CONCLUSION

Protein-energy malnutrition is a common and serious pathological situation in elderly hemodialysis patients which can be life-threatening.

Ultrafast electronic relaxations from the S3 state of pyrene

The ultrafast relaxation occurring in pyrene upon excitation at 4.68 eV was studied in a supersonic gas-jet fs pump–probe experiment.

Theoretical determination of adsorption and ionisation energies of polycyclic aromatic hydrocarbons on water ice

In dense interstellar environments, Polycyclic Aromatic Hydrocarbons (PAHs) are likely to condense onto or integrate into water ice mantles covering dust grains. Understanding the role of ice in the photo-induced processes involving adsorbed PAHs is therefore a key issue in astrochemistry. This requires (i) the knowledge of PAH-ice interactions, i.e. PAH-ice adsorption energies and local structures at the PAH-ice interface, as well as (ii) the understanding of the fate of electrons in the PAH-ice system upon excitation. Regarding (i), in this work, we determined the lowest energy structures of PAH-ice systems for a variety of PAHs ranging from naphthalene to ovalene on three types of ice - crystalline (Ih and Ic) and amorphous (low density) - using an explicit description of the electrons and a finite-sized system. The electronic structure was determined using the Self Consistent Charge Density Functional based Tight Binding (SCC-DFTB) scheme with modified Mulliken charges in order to ensure a good description of the studied systems. Regarding (ii), the influence of the interaction with ice on the Vertical Ionisation Potentials (VIPs) of the series of PAHs was determined using the constrained SCC-DFTB scheme benchmarked against correlated wavefunction results for PAH-(H₂O)_n (n = 1-6, 13) clusters. The results show a deviation equal, at most, to ∼1.4 eV of the VIPs of PAHs adsorbed on ice with respect to the gas phase values. Our results are discussed in the light of experimental data and previous theoretical studies.

Photochemistry of Fe:H2O Adducts in Argon Matrixes: A Combined Experimental and Theoretical Study in the Mid-IR and UV-Visible Regions

The photochemistry of Fe:H₂O adducts is of interest in fields as diverse as catalysis and astrochemistry. Industrially, iron can be used as a catalyst to convert H₂O to H₂, whereas in the interstellar medium it may be an important component of dust grains, influencing the chemistry on their icy surfaces. This study consisted of the deposition and spectral characterization of binary systems of atomic iron with H₂O in cryogenic argon matrixes. In this way, we were able to obtain information about the interaction of the two species; we observed the formation of adducts of iron monomers and dimers with water molecules in the mid-IR and UV-visible spectral domains. Upon irradiation with a UV radiation source, the iron species were inserted into the water molecules to form HFeOH and HFe₂OH, leading in some cases to the formation of FeO possibly accompanied by the production of H₂. DFT and correlated multireference wave function calculations confirmed our attributions. This combination of IR and UV-visible spectroscopy with theoretical calculations allowed us to determine, for the first time, the spectral characteristics of iron adducts and their photoproducts in the UV-visible and in the OH stretching region of the mid-IR domain.

Truncated Transition Densities for Analysis of (Nonlinear) Optical Properties of carbo-Chromophores

The optical properties of several quadrupolar carbo-benzene derivatives are investigated at various levels of calculation (TDDFT and CASPT2) and analyzed using a new theoretical tool here disclosed: The "visualization" of the transition dipole moment from the transition density truncated to the main monoexcitations involved in the electronic transition (TTD). The experimental or calculated one-photon UV-visible absorption spectra of the carbo-benzene derivatives fit with the Gouterman model originally proposed for porphyrins, where the first four excited states involve linear combinations of monoexcitations of the same four frontier molecular orbitals. The relative intensities of the absorption bands are analyzed from the transition dipole moments calculated from the TTDs and an analogy between porphyrins and carbo-benzenes is argued. The two-photon absorption (TPA) cross section related to the third-order nonlinear optical response is calculated for each two-photon-allowed excited state |f⟩ from the contribution of all possible intermediate excited states |i⟩ using the "sum-over-state" (SOS) scheme. The quadrupolar carbo-benzene derivatives fit into the three-level model, as their TPA cross section exhibits a dominant contribution of one of the intermediate excited states. The origin of TPA efficiency (enhancement) upon carbo-merisation of the C-C link to the para-substituents is discussed from the excitation energies of the intermediate and final excited states and from the two corresponding transition dipole moments (μ0i and μif). The latter may be calculated from the TTDs.

Electronic Spectroscopy of [FePAH](+) Complexes in the Region of the Diffuse Interstellar Bands: Multireference Wave Function Studies on [FeC6H6](+)

The low-energy states and electronic spectrum in the near-infrared-visible region of [FeC6H6](+) are studied by theoretical approaches. An exhaustive exploration of the potential energy surface of [FeC6H6](+) is performed using the density functional theory method. The ground state is found to be a (4)A1 state. The structures of the lowest energy states ((4)A2 and (4)A1) are used to perform multireference wave function calculations by means of the multistate complete active space with perturbation at the second order method. Contrary to the density functional theory results ((4)A1 ground state), multireference perturbative calculations show that the (4)A2 state is the ground state. The vertical electronic spectrum is computed and compared with the astronomical diffuse interstellar bands, a set of near-infrared-visible bands detected on the extinction curve in our and other galaxies. Many transitions are found in this domain, corresponding to d → d, d → 4s, or d → π* excitations, but few are allowed and, if they are, their oscillation strengths are small. Even though some band positions could match some of the observed bands, the relative intensities do not fit, making the contribution of the [Fe-C6H6](+) complexes to the diffuse interstellar bands questionable. This work, however, lays the foundation for the studies of polycyclic aromatic hydrocarbons (PAHs) complexed to Fe cations that are more likely to possess d → π* and π → π* transitions in the diffuse interstellar bands domain. PAH ligands indeed possess a larger number of π and π* orbitals, respectively, higher and lower in energy than those of C6H6, which are expected to lead to lower energy d → π* and π → π* transitions in [FePAH](+) than in [FeC6H6](+) complexes.

A rational reduction of CI expansions: combining localized molecular orbitals and selected charge excitations

Based on localized molecular orbitals, the proposed method reduces large configuration interaction (CI) spaces while maintaining agreement with reference values. Our strategy concentrates the numerical effort on physically pertinent CI-contributions and is to be considered as a tool to tackle large systems including numerous open-shells. To show the efficiency of our method we consider two 4-electron parent systems. First, we illustrate our approach by describing the van der Waals interactions in the (H2)2 system. By systematically including local correlation, dispersion and charge transfer mechanisms, we show that 90% of the reference full CI dissociation energy of the H2 dimer is reproduced using only 3% of the full CI space. Second, the conformational cis/trans rotation barrier of the butadiene molecule is remarkably reproduced (97% of the reference value) with less than 1% of the reference space. This work paves the way to numerical strategies which afford the electronic structure determination of large open-shell systems avoiding the exponential limitation. At the same time, a physical analysis of the contents of the wave function is offered.

Switching magnetic interactions in the NiFe Prussian Blue Analogue: an ab initio inspection

Wave function embedded cluster calculations are performed to stress a cation-coupled electron transfer process in the NiFe Prussian Blue Analogue.

In Search of Organic Compounds Presenting a Double Exchange Phenomenon

The objective of this paper is to design a consistent series of organic molecules that may present a double exchange mechanism and study their low energy spectrum using spin unrestricted Density Functional Theory. For this purpose, organic tetra-methylene methane units having an S = 1 spin ground state and diamagnetic organic bridges are taken as building blocks for constructing molecules having two or more magnetic units. When biunit systems are ionized, the ground state of the resulting molecular ions may be either a quartet, if the spectrum is ruled by a double exchange mechanism, or a doublet, if it obeys the logic of a monoelectronic picture. A strategy based on the physical analysis of the leading interactions is followed in order to energetically favor a high-spin ground state. It is shown that the most promising compounds involve bridges that have both a large gap between the highest occupied and the lowest unoccupied molecular orbitals and small coefficients on the atoms to which the magnetic units are connected. While the followed strategy enables one to conceive organic compounds exhibiting a double exchange phenomenon, it is shown that the electronic mechanism ruling the spectrum of such organic double exchange compounds is different from that of their inorganic homologues. A new method to reconstruct the spectrum of low energy from various spin unrestricted DFT solutions is proposed and applied. Finally monodimensional and bidimensional periodic lattices based on the most promising organic architecture are suggested.

Golimumab therapy of rheumatoid arthritis: an overview

Golimumab is a new approved humanized antibody for the treatment of rheumatoid arthritis (RA). This antibody belonging to biologic agents is raised against the pro-inflammatory cytokine tumour necrosis factor-alpha playing an essential role in the initiation of RA. To date, Golimumab administration for patients with RA, as indicated by USA Food and Drug Administration, is subcutaneous combined with methotrexate (MTX). Here, we have reviewed current literature with a focus on characteristics of Golimumab and also have exposed the clinical trials either using MTX or not using MTX. We have also highlighted the incoming clinical trials on Golimumab and have proposed some indications for the future studies based on a setting of clinical data and post-marketing observational studies. These studies will advance rheumatologists' decisions in the beginning of RA therapeutic interventions to insure the best outcomes for patients with RA and to improve their quality of life.

Inspection of the duality of a verdazyl-based radical in transition metal complexes: a pi* donor ligand and a magnetic partner

The behavior of a verdazyl-based radical bound to open-shell transition metal ions in the structurally and magnetically characterized [M(hfac)2imvd(o)] (M = Mn, Ni; hfac = (1,1,1,5,5,5)hexafluoroacetylacetonate; imvd(o) = 3-(2'-imidazolyl)-1,5-dimethyl-6-oxoverdazyl) complexes is rationalized using ab initio wave-function-based calculations analysis. The calculated exchange coupling constants J (H = -J(s(M) x s(imvd(o)); J(Mn)(calcd) = -63 cm(-1), J(Ni)(calcd) = 205 cm(-1)) are in excellent agreement with the experimental ones (J(Mn)(exp) = -63 cm(-1), J(Ni)(exp) = 193 cm(-1)). Even though both rings are involved through the binding mode of the imvd(o) radical, the spin density remains essentially localized on the nitrogen-rich ring. The singularity stems from its bidentate coordinating character. The analysis of the correlated wave function suggests that the verdazyl-based radical acts as a pi* donor ligand which allows ligand-to-metal charge transfer and excludes metal-to-ligand charge transfer. This reflects the weak covalent character of the M-imvd(o) pi coordination bond. From a magnetic point of view, the through-space exchange governs the ferromagnetic character in the Ni derivative up to 153 cm(-1) as expected from a description limited to the magnetic orbitals. Nevertheless, the CI expansion displays the participation of excited doublet and quartet states (spin polarization) on the verdazyl moiety which leads to a significant additional ferromagnetic contribution (52 cm(-1)). In the [Mn(hfac)2imvd(o)] analogue, the antiferromagnetic contribution arising from kinetic exchange is only one-third of the observed exchange coupling constant. It is necessary to introduce dynamical correlation effects to quantitatively recover the exchange interaction in this compound. Since the pi* donor and spin-polarized characters of the verdazyl moiety dominate over the negligible polarizability of the imidazole part, it is concluded that the noninnocent nature of the imvd(o) radical is held by the verdazyl ring part.