Unexpected and delayed fragmentation dynamics of the organometallic ferrocene induced by ion-collision.

We have investigated the fragmentation dynamics of the organometallic ferrocene molecule after interaction with multiply charged ions using multicoincidence mass spectrometry and quantum chemistry calculations. We observed unexpected fragmentation dynamics of the two-body breakup channels from ferrocene dications revealing a charge screening effect from the iron atom and delayed fragmentation dynamics. These observations are rationalized through the population of a specific long-lived excited state, where one positive charge is located on each cyclopentadienyl ring.

[Nasal reconstruction: Decision tree based on 229 operated cases]. / Reconstruction des pertes de substances du nez : algorithme décisionnel à propos de 229 cas.

BACKGROUND: The Face is the most frequent localization for cutaneous carcinoma. The nose accounts for about 30% of these tumors. Nose tissue loss repair has to pursue 3 types of objectives: carcinologic, aesthetic and functional. The aim of this article is to identify a decision tree to guide the choice of surgical reconstruction technique based on localization and size of the defect. PATIENTS AND METHODS: We performed a retrospective analysis in Angers' CHU from 2013 to 2019 including 229 patients referred for cutaneous tumors excision in need of reconstruction. We analyzed the type of reconstruction, size of the tissue loss and localization of the defect in terms of nose aesthetic subunits. RESULTS: Among the 229 patients included, the most frequent localization was nose tip (32%). 44% of patients were reconstructed with skin grafts or composite graft, 56% with flaps (48% local flaps and 4% association of both methods). Limited central resections of nose tip were reconstructed with skingraft. The Rybka flap and bilobed flap were the preferred choice for lateral reconstruction of nose tip. Largest tip defects were reconstructed using Rieger flap or forehead flap. The dorsum was often reconstructed with local flap: glabellar on the upper part, Rieger on the lower part. Lateral side was perfectly reconstructed with island flap. Nose wings needed framework: composite graft was the judicious choice in case of limited tissue loss whereas forehead flap with framework or Schmid-Meyer flap were chosen for larger defects. CONCLUSION: Our past experience in nasal reconstruction has provided us with an original decision tree to guide surgeons in choosing the right reconstruction technique according to the size and localization of the defect.

Sleep parameters improvement in PTSD soldiers after symptoms remission.

Eye movement desensitization and reprocessing (EMDR) is a psychotherapy for the treatment of posttraumatic stress disorder (PTSD). It is still unclear whether symptoms remission through EMDR therapy is associated with a beneficial effect on one of the PTSD symptoms, sleep disturbance. Our objective was therefore to study sleep parameters before and after symptom remission in soldiers with PTSD. The control group consisted of 20 healthy active duty military men who slept in a sleep lab with standard polysomnography (PSG) on two sessions separated by one month. The patient group consisted of 17 active duty military with PTSD who underwent EMDR therapy. PSG-recorded sleep was assessed 1 week before the EMDR therapy began and 1 week after PTSD remission. We found that the increased REMs density after remission was positively correlated with a greater decrease of symptoms. Also, the number of EMDR sessions required to reach remission was correlated with intra-sleep awakenings before treatment. These results confirm the improvement of some sleep parameters in PTSD after symptoms remission in a soldier's population and provide a possible predictor of treatment success. Further experiments will be required to establish whether this effect is specific to the EMDR therapy.

Involvement of the cerebellum in EMDR efficiency: a metabolic connectivity PET study in PTSD.

BACKGROUND: We recently reported an improvement of precuneus PET metabolism after EMDR therapy in military participants suffering from PTSD. OBJECTIVE: The aim of the present study was to investigate the metabolic changes of precuneus connectivity in these participants after such treatment. METHOD: Fifteen participants with PTSD performed a brain 18F-FDG-PET sensitized by virtual reality exposure to war scenes, before and after EMDR treatment. Inter-regional correlation analysis was performed to study metabolic changes of precuneus connectivity through SPMT maps at whole-brain level (p < 0.005 for the voxel, p < 0.05 for the cluster). RESULTS: A decrease of connectivity was observed after EMDR between the precuneus and two significant bilateral clusters of the cerebellum (bilateral Crus I and VI cerebellar lobules, Tmax voxel of 5.8 and 5.3, and cluster size of 343 and 314 voxels, respectively). Moreover, higher cerebellar metabolism before treatment was associated with reduced clinical PTSD scores after EMDR (p = 0.03). CONCLUSIONS: The posterior cerebellum and its metabolic connectivity with the precuneus are involved in the clinical efficiency of EMDR in PTSD.

Antecedentes: Recientemente informamos una mejora del metabolismo de PET precuneus después de la terapia EMDR en participantes militares que padecen TEPT.Objetivo: El objetivo del presente estudio fue investigar los cambios metabólicos en la conectividad precuneus en estos participantes después de dicho tratamiento.Métodos: Quince participantes con trastorno de estrés postraumático se sometieron a 18F-FDG-PET cerebral sensibilizado por la exposición de realidad virtual a escenas de guerra antes y después del tratamiento con EMDR. El análisis de correlación interregional se realizó para estudiar los cambios metabólicos en la conectividad precuneus a través de mapas SPM-T a nivel de todo el cerebro (p <0.005 para el vóxel, p <0.05 para el grupo).Resultados: Se observó una disminución en la conectividad después de la terapia EMDR entre el precúneo y dos grupos bilaterales significativos del cerebelo (vóxeles Tmax de 5.8 y 5.3 y tamaños de racimo de 343 y 314 vóxeles, respectivamente). Además, un metabolismo cerebeloso más alto antes del tratamiento se asoció con puntuaciones clínicas de TEPT reducidas después de EMDR (p = 0.03).Conclusión: el cerebelo y su conectividad metabólica con el precuneus están involucrados en la eficiencia clínica de EMDR en TEPT.

Vibrationally Mediated Stabilization of Electrons in Nonpolar Matter.

We explore solvation of electrons in nonpolar matter, here represented by butadiene clusters. Isolated butadiene supports only the existence of transient anions (resonances). Two-dimensional electron energy loss spectroscopy shows that the resonances lead to an efficient vibrational excitation of butadiene, which can result into the almost complete loss of energy of the interacting electron. Cluster-beam experiments show that molecular clusters of butadiene form stable anions, however only at sizes of more than 9 molecular units. We have calculated the distribution of electron affinities of clusters using classical and path integral molecular dynamics simulations. There is almost a continuous transition from the resonant to the bound anions with an increase in cluster size. The comparison of the classical and quantum dynamics reveals that the electron binding is strongly supported by molecular vibrations, brought about by nuclear zero-point motion and thermal agitation. We also inspected the structure of the solvated electron, finding it well localized.

Increase of precuneus metabolism correlates with reduction of PTSD symptoms after EMDR therapy in military veterans: an 18F-FDG PET study during virtual reality exposure to war.

PURPOSE: The prevalence of posttraumatic stress disorder (PTSD) is higher among veterans, and can lead to disastrous consequences such as suicide. Eye movement desensitization and reprocessing (EMDR) is recommended in first-line psychotherapies for PTSD. Virtual reality exposure (VRE) coupled with 18F-FDG PET imaging can highlight the activated brain regions during stress exposure. The objective of this study is to identify, after EMDR therapy, the regions of brain metabolism that evolve during the stress exposure of a war scene with symptomatic remission in a group of military veterans suffering from PTSD, and to secondarily search for predictive metabolic features. METHODS: We recruited 15 military veterans suffering from PTSD who performed an 18F-FDG PET sensitized by the exposure to a virtual war scene, before (T0) and after (T1) EMDR therapy. Statistical parametric mapping was used to compare brain metabolism before and after treatment and to study correlations between metabolism and evolution scores on PTSD clinical scales (PTSD Checklist Scale, PCLS; Clinician-Administered PTSD Scale, CAPS). RESULTS: The metabolic activity of the precuneus was increased after EMDR therapy (p < 0.005 uncorrected, k > 180) and correlated with clinical improvement with the CAPS scale (r = -0.73 and p < 0.001). Moreover, the precuneus metabolic value before therapy predicted the clinical improvement on the PCLS scale (T1-T0) after EMDR (r = -0.667 and p < 0.006). CONCLUSION: The clinical improvement in military patients with PTSD after EMDR is related to increased precuneus metabolism upon VR stress exposure.

Publisher Correction: Control of laser plasma accelerated electrons for light sources.

The original version of this Article contained an error in the last sentence of the first paragraph of the Introduction and incorrectly read 'A proper electron beam control is one of the main challenges towards the Graal of developing a compact alternative of X-ray free-electron lasers by coupling LWFA gigaelectron-volts per centimetre acceleration gradient with undulators in the amplification regime in equation 11, nx(n-ß) x ß: n the two times and beta the two times should be bold since they are vectorsin Eq. 12, ß should be bold as well.' The correct version is 'A proper electron beam control is one of the main challenges towards the Graal of developing a compact alternative of X-ray free-electron lasers by coupling LWFA gigaelectron-volts per centimetre acceleration gradient with undulators in the amplification regime.'This has been corrected in both the PDF and HTML versions of the Article.

Control of laser plasma accelerated electrons for light sources.

With gigaelectron-volts per centimetre energy gains and femtosecond electron beams, laser wakefield acceleration (LWFA) is a promising candidate for applications, such as ultrafast electron diffraction, multistaged colliders and radiation sources (betatron, compton, undulator, free electron laser). However, for some of these applications, the beam performance, for example, energy spread, divergence and shot-to-shot fluctuations, need a drastic improvement. Here, we show that, using a dedicated transport line, we can mitigate these initial weaknesses. We demonstrate that we can manipulate the beam longitudinal and transverse phase-space of the presently available LWFA beams. Indeed, we separately correct orbit mis-steerings and minimise dispersion thanks to specially designed variable strength quadrupoles, and select the useful energy range passing through a slit in a magnetic chicane. Therefore, this matched electron beam leads to the successful observation of undulator synchrotron radiation after an 8 m transport path. These results pave the way to applications demanding in terms of beam quality.

Hübner's tarsomarginal grafts in eyelid reconstruction: 94 cases.

BACKGROUND: Preserving the integrity of the eyelid margin in eyelid reconstruction remains a challenge for plastic surgeons. In 1976, Hübner described a technique to repair full-thickness eyelid defects using a tarsomarginal graft covered with a local flap. This simple technique addresses both functional and aesthetic requirements of eyelid reconstruction by using tissue from the contralateral eyelid. The aim of this study was to determine the appropriate role of this uncommon technique in eyelid reconstruction. METHOD: In total, 94 tarsomarginal grafts were performed on 70 patients. Eight surgeons participated in this study. Data were retrospectively collected from patients' charts and all information regarding surgical indications, histology, defect size and topography, operative time, immediate result, and potential complications were recorded. RESULTS: Only one of the patients suffered total necrosis. Partial wound dehiscence occurred in one case and partial necrosis occurred in 6 cases. No major sequelae were observed in the donor eyelids. In 100% of cases, eyelid margin integrity was otherwise preserved. Four patients required revision surgery for insufficient malignancy resection and 13 patients for long-term eyelid ectropion or scar retraction. CONCLUSION: This simple and reliable technique ensured the closure of full-thickness eyelid defects covering up to 3/4 of the eyelid length. The procedure should be more widely used as it guarantees high-quality eyelid reconstruction.

Solitary fibrous tumours and haemangiopericytoma of the meninges. A retrospective study for outcome and prognostic factor assessment.

BACKGROUND: To report on the outcome of patients diagnosed with central nervous system haemangiopericytoma (HPC) or solitary fibrous tumours (SFT) and identify factors that may influence recurrence and survival. MATERIAL AND METHODS: Between January 1977 and December 2016, a retrospective search identified 22 HPCs/SFTs. The patients underwent a total of 40 surgical resections and 63.6% received radiotherapy. Median follow-up was 7.8 years. RESULTS: Six patients (27.3%) were re-operated for tumour recurrence. At the end of the study, 15 patients (68.2%) had no residual tumour on the last imaging. Surgical recurrence-free survival at 5 years was 77.4%, [95% CI: 60.1-99.8]. None of the investigated variables was associated with recurrence. At the end of the study, 5 patients were deceased (22.7%) and only 10 patients (45.5%) had no residual tumour on the last imaging and were alive. Overall survival at 5 years was 95%, [95% CI: 85.9-100]. None of the investigated variables was associated with overall survival. Patients who received radiotherapy demonstrated neither a reduced risk of surgical recurrence (P=0.378) nor a longer overall survival (P=0.405). CONCLUSION: SFTs/HPCs are associated with a significant risk of recurrence that may reduce the survival. Even if we could not demonstrate their benefit in this limited series, we believe that tailored maximal tumour resection on initial surgery is beneficial and that adjuvant RT is useful for tumours displaying grade II or III, even in case of complete removal.

Fragmentation of pure and hydrated clusters of 5Br-uracil by low energy carbon ions: observation of hydrated fragments.

The fragmentation of the isolated 5-bromouracil (5BrU) molecule and pure and nano-hydrated 5BrU clusters induced by low energy 12C4+ ions has been studied. A comparison indicates that the environment, on the one hand, protects the system against the complete break-up into small fragments, but, on the other hand, triggers 'new' pathways for fragmentation, for example the loss of the OH group. The most striking result is the observation of several series of hydrated fragments in the hydrated cluster case, with water molecules bound to hydrophilic sites of 5BrU. This highlights the strong interaction between 5BrU and water molecules and the blocking of specific fragmentation pathways, such as the loss of the BrC2H group for example.

Multiple electron capture from isolated protein poly-anions in collision with slow highly charged ions.

Collisions of 375 keV Xe25+ ions with trapped mass/charge selected poly-anions of the cytochrome C protein (∼12.5 kDa) were studied by coupling a linear quadrupole ion trap with low-energy ion beam facility. Tandem mass spectra were recorded for the protein precursor charge states ranging from -9 to -17. The present work reports the first study of slow highly charged ion collisions with poly-anions. A high signal to noise ratio allowed the study of the intensity of single and multiple electron removal by a projectile, as well as associated neutral losses, as a function of the target charge state. Relative single and double electron detachment cross sections were found to increase with increasing charge state of the precursor anion. The experimental findings are supported by the calculations of the total electron capture cross sections, based on the classical over-the-barrier model, restricted to a simple uniformly charged linear protein structure and a near-end electron capture.

[Light sources usable by the plastic surgeon in the absence of photographic studio]. / Sources lumineuses utilisables par le chirurgien plasticien en l'absence de studio photographique.

Medical photography is an important part of the medical file and is widely used in medical communication, especially in our discipline. His practice has to be the most standardized and reproducible as possible, which distinguishes it from artistic photography. Photography fix the light reflecting from a subject, so surgeon have to control of the light source in any environment. In the absence of dedicated studio, using external cobra or ring flashes with special diffusers allow the surgeon to have light sources adapted to the different conditions encountered in daily practice.

Determination of Energy-Transfer Distributions in Ionizing Ion-Molecule Collisions.

The ionization and fragmentation of the nucleoside thymidine in the gas phase has been investigated by combining ion collision with state-selected photoionization experiments and quantum chemistry calculations. The comparison between the mass spectra measured in both types of experiments allows us to accurately determine the distribution of the energy deposited in the ionized molecule as a result of the collision. The relation of two experimental techniques and theory shows a strong correlation between the excited states of the ionized molecule with the computed dissociation pathways, as well as with charge localization or delocalization.

Rapid onset of squamous cell carcinoma in a thin skin graft donor site.

BACKGROUND: Squamous cell carcinomas are malignant tumours of epithelial origin that can appear on sites subjected to chronic inflammation after a period of several years. The rapid development of squamous cell carcinoma at the donor site for a thin skin graft is a rare and poorly understood situation. PATIENTS AND METHODS: We report the case of a patient undergoing thin skin grafting to cover the area of removal of a vertex squamous cell carcinoma and in whom squamous cell carcinoma appeared at the donor site within 9 weeks. DISCUSSION: In our case, we ruled out intraoperative contamination because two sets of surgical instruments were used. Given the number of cases reported in the literature, a chance event seems unlikely. The hypothesis of an acute inflammatory process caused by scarring of the thin skin graft site appears to us the most convincing. Development of cancer at the graft donor site may thus be added to the list of complications of thin skin grafting.

[Impulsivity: What are the consequences on compliance to rehabilitation?]. / L'impulsivité : quelles conséquences sur l'adhésion aux soins ? Présentation d'une étude réalisée en addictologie.

INTRODUCTION: Impulsivity is a transnosographical dimension with major consequences on medical care with which psychiatrists are frequently confronted. Furthermore, compliance is a major variable that can affect the efficiency of therapeutics and hospitalizations in psychiatry. A study was carried out in three drug and alcohol rehabilitation hospitalization units to find out if impulsivity can have consequences on compliance. METHOD: The studied population was composed of 85 patients aged from 18 to 70, hospitalized for one or more addiction disorders in a psychometric hospital in Vannes (France). Impulsivity was measured for all patients with the BIS-11 at the beginning of the rehabilitation program. Because no tool to evaluate a total rehab program compliance existed, a scale, used at the end of the hospitalization, was created to measure patient compliance. This score was composed of two simple numeric scales (one used by the nurses and one used by the patient's psychiatrist) and a coefficient of hospitalization duration that was the ratio of completed to planned days of hospitalization. Correlations were made between the different dimensions: impulsivity and compliance, impulsivity and hospitalization conditions, compliance and hospitalization conditions (voluntary or involuntary, planned by a psychiatrist or not, etc.). RESULTS: The main statistically significant result of the study was a negative correlation existing between the motor dimension of impulsivity and compliance (r=-0.37 and P=0.001). The other dimensions of impulsivity showed no significant correlation with compliance score. The study revealed that the different hospitalization conditions showed no link with compliance or impulsivity. CONCLUSION: These original results show that motor impulsive patients need an adaptation of the rehabilitation programs. Shorter programs might be more efficient.

Site- and state-selected photofragmentation of 2Br-pyrimidine.

The fragmentation of the 2Br-pyrimidine molecule following direct valence photoionization or inner shell excitation has been studied by electron-ion coincidence experiments. 2Br-pyrimidine has been chosen as a model for the class of pyrimidinic building blocks of three nucleic acids and several radiosensitizers. It is known that the site- and state-localization of energy deposition, typical of inner shell excitation, results in the enhancement of the total ion yield as well as in changes in the relative intensity of the different fragmentation channels. Here we address the question of the origin of this selective fragmentation by using electron-ion coincidence techniques. The results show that the fragmentation is strongly selective in the final singly charged ion state, independently of the process that leads to the population of that state, and the dominant fragmentation patterns correlate with the nearest appearance potential.

Childhood neglect predicts disorganization in schizophrenia through grey matter decrease in dorsolateral prefrontal cortex.

OBJECTIVE: Psychosocial trauma during childhood is associated with schizophrenia vulnerability. The pattern of grey matter decrease is similar to brain alterations seen in schizophrenia. Our objective was to explore the links between childhood trauma, brain morphology and schizophrenia symptoms. METHOD: Twenty-one patients with schizophrenia stabilized with atypical antipsychotic monotherapy and 30 healthy control subjects completed the study. Anatomical MRI images were analysed using optimized voxel-based morphometry (VBM). Childhood trauma was assessed with the Childhood Trauma Questionnaire, and symptoms were rated on the Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS) (disorganization, positive and negative symptoms). In the schizophrenia group, we used structural equation modelling in a path analysis. RESULTS: Total grey matter volume was negatively associated with emotional neglect (EN) in patients with schizophrenia. Whole-brain VBM analyses of grey matter in the schizophrenia group revealed a specific inversed association between EN and the right dorsolateral prefrontal cortex (DLPFC). Path analyses identified a well-fitted model in which EN predicted grey matter density in DLPFC, which in turn predicted the disorganization score. CONCLUSION: Our findings suggest that EN during childhood could have an impact on psychopathology in schizophrenia, which would be mediated by developmental effects on brain regions such as the DLPFC.

Formation of H2 from internally heated polycyclic aromatic hydrocarbons: excitation energy dependence.

We have investigated the effectiveness of molecular hydrogen (H2) formation from Polycyclic Aromatic Hydrocarbons (PAHs) which are internally heated by collisions with keV ions. The present and earlier experimental results are analyzed in view of molecular structure calculations and a simple collision model. We estimate that H2 formation becomes important for internal PAH temperatures exceeding about 2200 K, regardless of the PAH size and the excitation agent. This suggests that keV ions may effectively induce such reactions, while they are unlikely due to, e.g., absorption of single photons with energies below the Lyman limit. The present analysis also suggests that H2 emission is correlated with multi-fragmentation processes, which means that the [PAH-2H](+) peak intensities in the mass spectra may not be used for estimating H2-formation rates.