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1.
Rev Neurol (Paris) ; 179(8): 914-922, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37019741

ABSTRACT

Treatment strategies in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) must be adapted on a case-to-case basis. Validated and reproducible tools for monitoring treatment response are required at diagnosis, when initiating treatment and throughout follow-up. A task force of French neurologists, experts in neuromuscular disease reference centers, was assembled to provide expert advice on the management of typical CIDP with intravenous immunoglobulins (Ig), and to harmonize treatment practices in public and private hospitals. The task force also referred to the practical experience of treating CIDP with Ig at the diagnostic, induction and follow-up stages, including the assessment and management of Ig dependence, and following the recommendations of the French health agency.


Subject(s)
Polyradiculoneuropathy, Chronic Inflammatory Demyelinating , Humans , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/diagnosis , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/therapy , Expert Testimony , Immunoglobulins, Intravenous/therapeutic use , France/epidemiology
2.
Commun Biol ; 5(1): 998, 2022 09 21.
Article in English | MEDLINE | ID: mdl-36130990

ABSTRACT

The reasons why some animals have developed larger brains has long been a subject of debate. Yet, it remains unclear which selective pressures may favour the encephalization and how it may act during evolution at different taxonomic scales. Here we studied the patterns and tempo of brain evolution within the order Carnivora and present large-scale comparative analysis of the effect of ecological, environmental, social, and physiological variables on relative brain size in a sample of 174 extant carnivoran species. We found a complex pattern of brain size change between carnivoran families with differences in both the rate and diversity of encephalization. Our findings suggest that during carnivorans' evolution, a trade-off have occurred between the cognitive advantages of acquiring a relatively large brain allowing to adapt to specific environments, and the metabolic costs of the brain which may constitute a disadvantage when facing the need to colonize new environments.


Subject(s)
Carnivora , Fossils , Animals , Biological Evolution , Brain/physiology , Organ Size
5.
Rev Med Interne ; 42(2): 110-119, 2021 Feb.
Article in French | MEDLINE | ID: mdl-33172708

ABSTRACT

Fabry disease is the second most frequent lysosomal storage disorder. It is a X-linked genetic disease secondary to alpha-galactosidase A enzyme deficiency. This is a progressive and systemic disease that affects both males and females. Classical symptoms and organ involvements are acral pain crisis, cornea verticillata, hypertrophic cardiomyopathy, stroke and chronic kidney disease with proteinuria. Nevertheless, organ damages can be missing or pauci-symptomatic and other common symptoms are poorly recognised, such as gastrointestinal or ear involvement. In classical Fabry disease, symptoms first appear during childhood or teenage in males, but later in females. Patients may have non-classical or late-onset Fabry disease with delayed manifestations or with single-organ involvement. Recognition of Fabry disease is important because treatments are available, but it may be challenging. Diagnosis is easy in males, with dosage of alpha-galactosidase A enzyme activity into leukocytes, but more difficult in females who can express normal residual activity. Other plasmatic biomarkers, such as lyso-globotriaosylceramide (lyso-Gb3), are interesting in females, but need to be associated with GLA gene analysis. In this review, we aimed at summarize the main clinical manifestations of Fabry disease and propose a practical algorithm to know how to diagnose this complex disease.


Subject(s)
Fabry Disease , Stroke , Adolescent , Biomarkers , Disease Progression , Fabry Disease/complications , Fabry Disease/diagnosis , Fabry Disease/epidemiology , Female , Humans , Male , alpha-Galactosidase/genetics
6.
Rev Med Interne ; 41(3): 180-188, 2020 Mar.
Article in French | MEDLINE | ID: mdl-31959364

ABSTRACT

Mucopolysaccharidosis are lysosomal storage diseases, secondary to the accumulation of mucopolysaccharides. Type 1 mucopolysaccharidosis is the most common form and affects between 0.69 and 1.66 newborns per 100,000. The severity of mucopolysaccharidosis is variable with lethal forms in utero and attenuated forms diagnosed in adults. The most common symptoms are short stature, facial dysmorphism, chronic articular pains that can mimic chronic inflammatory rheumatism, axial and peripheral bone involvement, hepatosplenomegaly and an early carpal tunnel. Depending on the type of mucopolysaccharidosis, corneal, cerebral or cardiac involvements are possible. Screening is based on the analysis of urinary glycosaminoglycans. The deficient enzyme assay and the gene analysis confirm the diagnosis. Mucopolysaccharidosis recognition is important for patient management and family screening. In addition, specific enzyme replacement therapy exists for certain types of mucopolysaccharidosis. Role of clinician is important to evoke and diagnose mucopolysaccharidosis.


Subject(s)
Mucopolysaccharidoses/diagnosis , Adult , Arthritis, Rheumatoid/diagnosis , Diagnosis, Differential , Enzyme Replacement Therapy , Female , Genetic Testing , Humans , Infant, Newborn , Mucopolysaccharidoses/epidemiology , Mucopolysaccharidoses/therapy , Pregnancy , Prenatal Care , Prognosis
7.
Rev Med Interne ; 41(2): 98-105, 2020 Feb.
Article in French | MEDLINE | ID: mdl-31898997

ABSTRACT

In France, clinical research involving human beings is regulated by the Jardé's law since November 2016. The law distinguishes interventional and non-interventional studies. Both need to be authorized by a Persons Protection Committee. Studies performed on medical data collected during standard clinical care are not considered as studies involving human beings. Medical data are personal data. French Data Protection Authority National has an important role, guarantying the respect of regulation on personal data. We summarize in this article the different types of studies and the role of regulatory authorities.


Subject(s)
Biomedical Research/legislation & jurisprudence , Government Regulation , Computer Security/legislation & jurisprudence , France , Humans , Medical Records/legislation & jurisprudence , Medical Records/standards , Patient Rights/legislation & jurisprudence
8.
Rev Med Interne ; 40(8): 517-522, 2019 Aug.
Article in French | MEDLINE | ID: mdl-30981561

ABSTRACT

Classification criteria for systemic sclerosis evolved over the last three decades, allowing an earlier classification. In the late 2000s, the EULAR Scleroderma Trials and Research Group validated very early and early systemic sclerosis criteria. Raynaud phenomenon, anti-nuclear antibody positivity and the puffy fingers are "Red flags" that must lead to refer the patient to a specialist and benefit from a capillaroscopy and the specific autoantibodies. At the stage of very early systemic sclerosis, pulmonary, cardiac and digestive involvements may be present and must be screened. Herein, we detail very early and early systemic sclerosis criteria, as well as the predictive factors of evolution towards a systemic sclerosis.


Subject(s)
Scleroderma, Systemic/classification , Scleroderma, Systemic/diagnosis , Antibodies, Antinuclear/blood , Autoantibodies/blood , Decision Trees , Disease Progression , Early Diagnosis , Humans
10.
Eur J Neurol ; 25(12): 1439-1445, 2018 12.
Article in English | MEDLINE | ID: mdl-29996003

ABSTRACT

BACKGROUND AND PURPOSE: Mitoxantrone (MITOX) has been used to treat patients with aggressive multiple sclerosis (MS) for decades. We aimed to describe the effectiveness and adverse events over 10 years post-MITOX in patients with relapsing and progressive MS from an exhaustive real-life database. METHODS: Data from patients who received MITOX before 1 January 2006 were collected from the MS Lorraine registry. Expanded Disability Status Scale (EDSS) scores and annual relapse rates (ARRs) year by year during follow-up and the year prior to MITOX were compared. Time to the first relapse and a 1-point increase in EDSS score were used in Cox multivariate models to find associations with potential predictive factors. RESULTS: A total of 411 patients were included. The ARR for the 155 relapsing patients had decreased from 2.0 (SD 1.20) the year before treatment to 0.3 (SD 0.31) by year 10 (P < 0.0001). The EDSS score increased from 2.8 (SD 1.44) to 4.8 (SD 1.90) by year 10 (P < 0.0001). A high ARR at MITOX initiation was associated with a longer time to a 1-point increase in EDSS score (hazard ratio, 0.81; 95% confidence interval, 0.67-0.99; P = 0.04). The EDSS score in 256 progressive patients increased from 5.0 (SD 1.33) to 6.5 (SD 1.26) by year 10 (P < 0.0001). We identified four cases of acute myeloid leukemias. CONCLUSIONS: Patients with the most active forms of MS are the most likely to benefit from MITOX in the long term.


Subject(s)
Mitoxantrone/therapeutic use , Multiple Sclerosis, Chronic Progressive/drug therapy , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Topoisomerase II Inhibitors/therapeutic use , Adult , Cohort Studies , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Withholding Treatment
11.
Rev Neurol (Paris) ; 174(6): 378-390, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29673575

ABSTRACT

The diagnosis of multiple sclerosis (MS) and other demyelinating diseases of the central nervous system is challenging, and although the currently available biological and imaging tools offer considerable support to physicians, these tools often fail to provide a simple and final answer at the time of a first event. Thus, sets of diagnostic criteria have been published and tested on patient cohorts, and are now used in clinical trials and in daily clinical practice. These criteria have evolved over time to take into account physicians' and patients' needs, along with emerging paraclinical tests. The different presentations of MS have given rise to the use of a common classification system to identify patient profiles and adapt care protocols accordingly. This article reviews the various classifications of the forms and diagnostic criteria of MS and related syndromes, including neuromyelitis optica (NMO)/NMO spectrum disorders (NMOSDs), acute disseminated (demyelinating) encephalomyelitis (ADEM) and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). Also discussed is their validity in the light of the currently available literature.


Subject(s)
Central Nervous System Diseases/classification , Central Nervous System Diseases/diagnosis , Demyelinating Diseases/classification , Demyelinating Diseases/diagnosis , Encephalomyelitis, Acute Disseminated/diagnosis , Humans , Inflammation/classification , Inflammation/diagnosis , Multiple Sclerosis/diagnosis , Neuromyelitis Optica/diagnosis , Syndrome
14.
Rev Med Interne ; 36(4): 237-42, 2015 Apr.
Article in French | MEDLINE | ID: mdl-25554401

ABSTRACT

PURPOSE: Cryofibrinogenemia is an unknown disorder and studies dedicated to it are limited. The aim of our study was to report on the incidence, clinical manifestations and associated diseases in patients with isolated cryofibrinogenemia. METHODS: This is a retrospective single-center study. Patients included in this study had a positive and isolated detection of cryofibrinogen between January 1st, 2011 and December 31st, 2012. Identification was possible through the database of the laboratory of immunology. RESULTS: Two hundred and eighty-one consecutive orders of cryofibrinogenemia were identified. Seventy-three patients had a positive detection of cryofibrinogenemia. Among them, 12 had an isolated cryofibrinogenemia and sixty-one patients (84%) had concomitant cryofibrinogenemia and cryoglobulinemia. The mean age was 59±19years. Seven patients were female (58%). Cutaneous manifestations were present in half case. Peripheral nerve involvement was present in 5 cases (42%) and rheumatic manifestations in 4 patients (33%). A thrombotic event was reported in 7 patients (58%). Renal impairment was present in 7 patients. The median cryofibrinogen concentration was 254±304mg/L. Five patients had a secondary cryofibrinogenemia. The most often prescribed treatment was corticosteroids. CONCLUSION: Cryofibrinogenemia is an unknown disorder. Testing for cryoglobulinemia is more frequent than for cryofibrinogenemia whereas clinical manifestations are similar. Detection of cryofibrinogen is positive in most of the cases, with an important prevalence of thrombotic events in this population. This study confirms the importance of conducting prospective studies on cryofibrinogenemia.


Subject(s)
Cryoglobulinemia , Cryoglobulinemia/diagnosis , Female , France , Hospitals, University , Humans , Incidence , Male , Middle Aged , Retrospective Studies
15.
Cell Death Differ ; 21(1): 92-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24037090

ABSTRACT

Clinical oncology heavily relies on the use of radiotherapy, which often leads to merely transient responses that are followed by local or distant relapse. The molecular mechanisms explaining radioresistance are largely elusive. Here, we identified a dual role of autophagy in the response of cancer cells to ionizing radiation. On one hand, we observed that the depletion of essential autophagy-relevant gene products, such as ATG5 and Beclin 1, increased the sensitivity of human or mouse cancer cell lines to irradiation, both in vitro (where autophagy inhibition increased radiation-induced cell death and decreased clonogenic survival) and in vivo, after transplantation of the cell lines into immunodeficient mice (where autophagy inhibition potentiated the tumour growth-inhibitory effect of radiotherapy). On the other hand, when tumour proficient or deficient for autophagy were implanted in immunocompetent mice, it turned out that defective autophagy reduced the efficacy of radiotherapy. Indeed, radiotherapy elicited an anti-cancer immune response that was dependent on autophagy-induced ATP release from stressed or dying tumour cells and was characterized by dense lymphocyte infiltration of the tumour bed. Intratumoural injection of an ecto-ATPase inhibitor restored the immune infiltration of autophagy-deficient tumours post radiotherapy and improved the growth-inhibitory effect of ionizing irradiation. Altogether, our results reveal that beyond its cytoprotective function, autophagy confers immunogenic properties to tumours, hence amplifying the efficacy of radiotherapy in an immunocompetent context. This has far-reaching implications for the development of pharmacological radiosensitizers.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Autophagy/radiation effects , Gamma Rays , Membrane Proteins/metabolism , Microtubule-Associated Proteins/metabolism , Animals , Apoptosis Regulatory Proteins/antagonists & inhibitors , Apoptosis Regulatory Proteins/genetics , Autophagy-Related Protein 5 , Beclin-1 , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cell Line, Tumor , Humans , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , Microtubule-Associated Proteins/antagonists & inhibitors , Microtubule-Associated Proteins/genetics , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/radiotherapy , RNA Interference , RNA, Small Interfering/metabolism , Transplantation, Heterologous
16.
Cell Death Differ ; 21(1): 59-68, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23787997

ABSTRACT

The exposure of calreticulin (CRT) on the surface of stressed and dying cancer cells facilitates their uptake by dendritic cells and the subsequent presentation of tumor-associated antigens to T lymphocytes, hence stimulating an anticancer immune response. The chemotherapeutic agent mitoxantrone (MTX) can stimulate the peripheral relocation of CRT in both human and yeast cells, suggesting that the CRT exposure pathway is phylogenetically conserved. Here, we show that pheromones can act as physiological inducers of CRT exposure in yeast cells, thereby facilitating the formation of mating conjugates, and that a large-spectrum inhibitor of G protein-coupled receptors (which resemble the yeast pheromone receptor) prevents CRT exposure in human cancer cells exposed to MTX. An RNA interference screen as well as transcriptome analyses revealed that chemokines, in particular human CXCL8 (best known as interleukin-8) and its mouse ortholog Cxcl2, are involved in the immunogenic translocation of CRT to the outer leaflet of the plasma membrane. MTX stimulated the production of CXCL8 by human cancer cells in vitro and that of Cxcl2 by murine tumors in vivo. The knockdown of CXCL8/Cxcl2 receptors (CXCR1/Cxcr1 and Cxcr2) reduced MTX-induced CRT exposure in both human and murine cancer cells, as well as the capacity of the latter-on exposure to MTX-to elicit an anticancer immune response in vivo. Conversely, the addition of exogenous Cxcl2 increased the immunogenicity of dying cells in a CRT-dependent manner. Altogether, these results identify autocrine and paracrine chemokine signaling circuitries that modulate CRT exposure and the immunogenicity of cell death.


Subject(s)
Calreticulin/metabolism , Interleukin-8/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Animals , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Cell Line, Tumor , Chemokine CXCL2/metabolism , Dendritic Cells/immunology , Dendritic Cells/metabolism , HCT116 Cells , HeLa Cells , Humans , Interleukin-8/antagonists & inhibitors , Interleukin-8/genetics , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mitoxantrone/therapeutic use , Mitoxantrone/toxicity , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Receptors, Interleukin-8A/antagonists & inhibitors , Receptors, Interleukin-8A/genetics , Receptors, Interleukin-8A/metabolism , Receptors, Interleukin-8B/antagonists & inhibitors , Receptors, Interleukin-8B/genetics , Receptors, Interleukin-8B/metabolism , Saccharomyces cerevisiae/classification , Saccharomyces cerevisiae/metabolism , Signal Transduction , Transcriptome/drug effects
17.
Cell Death Differ ; 21(1): 79-91, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23852373

ABSTRACT

The immunogenic demise of cancer cells can be induced by various chemotherapeutics, such as anthracyclines and oxaliplatin, and provokes an immune response against tumor-associated antigens. Thus, immunogenic cell death (ICD)-inducing antineoplastic agents stimulate a tumor-specific immune response that determines the long-term success of therapy. The release of ATP from dying cells constitutes one of the three major hallmarks of ICD and occurs independently of the two others, namely, the pre-apoptotic exposure of calreticulin on the cell surface and the postmortem release of high-mobility group box 1 (HMBG1) into the extracellular space. Pre-mortem autophagy is known to be required for the ICD-associated secretion of ATP, implying that autophagy-deficient cancer cells fail to elicit therapy-relevant immune responses in vivo. However, the precise molecular mechanisms whereby ATP is actively secreted in the course of ICD remain elusive. Using a combination of pharmacological screens, silencing experiments and techniques to monitor the subcellular localization of ATP, we show here that, in response to ICD inducers, ATP redistributes from lysosomes to autolysosomes and is secreted by a mechanism that requires the lysosomal protein LAMP1, which translocates to the plasma membrane in a strictly caspase-dependent manner. The secretion of ATP additionally involves the caspase-dependent activation of Rho-associated, coiled-coil containing protein kinase 1 (ROCK1)-mediated, myosin II-dependent cellular blebbing, as well as the opening of pannexin 1 (PANX1) channels, which is also triggered by caspases. Of note, although autophagy and LAMP1 fail to influence PANX1 channel opening, PANX1 is required for the ICD-associated translocation of LAMP1 to the plasma membrane. Altogether, these findings suggest that caspase- and PANX1-dependent lysosomal exocytosis has an essential role in ATP release as triggered by immunogenic chemotherapy.


Subject(s)
Adenosine Triphosphate/metabolism , Antineoplastic Agents/toxicity , Cell Death/drug effects , Animals , Autophagy-Related Protein 5 , Cell Death/immunology , Cell Line, Tumor , Cell Membrane/metabolism , Connexins/antagonists & inhibitors , Connexins/genetics , Connexins/metabolism , DNA-Binding Proteins/antagonists & inhibitors , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , HMGB1 Protein/metabolism , Humans , Lysosomal-Associated Membrane Protein 1/antagonists & inhibitors , Lysosomal-Associated Membrane Protein 1/genetics , Lysosomal-Associated Membrane Protein 1/metabolism , Lysosomes/metabolism , Mice , Microtubule-Associated Proteins/antagonists & inhibitors , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Myosin Type II/metabolism , Nerve Tissue Proteins/antagonists & inhibitors , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , RNA Interference , RNA, Small Interfering/metabolism , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , rho-Associated Kinases/antagonists & inhibitors , rho-Associated Kinases/genetics , rho-Associated Kinases/metabolism
18.
Rev Med Interne ; 34(3): 171-3, 2013 Mar.
Article in French | MEDLINE | ID: mdl-23218067

ABSTRACT

INTRODUCTION: Thymomas, benign or malignant, may be associated with autoimmune diseases. They are classically associated with myasthenia gravis, neuromyotonia, or pure red cell aplasia. CASE REPORT: We here report, to the best of our knowledge, the first description of an association between thymoma and Reynolds syndrome (systemic sclerosis associated with primary biliary cirrhosis) in an 80-year-old woman. CONCLUSION: The suspected pathogenesis of this association could be a thymus escape of auto-reactive T lymphocytes and the consecutive development of an auto-immune disorder.


Subject(s)
Liver Cirrhosis, Biliary/diagnosis , Scleroderma, Systemic/diagnosis , Thymoma/diagnosis , Thymus Neoplasms/diagnosis , Aged, 80 and over , Female , Humans , Sjogren's Syndrome/diagnosis , Syndrome
19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 87: 0327011-327014, 2013 Mar 04.
Article in English | MEDLINE | ID: mdl-24976798

ABSTRACT

Radiopharmaceuticals emitting Auger electrons are often injected into patients undergoing cancer treatment with targeted radionuclide therapy (TRT). In this type of radiotherapy, the radiation source is radial and most of the emitted primary particles are low-energy electrons (LEEs) having kinetic energies distributed mostly from zero to a few hundred electron volts with very short ranges in biological media. These LEEs generate a high density of energy deposits and clustered damage, thus offering a relative biological effectiveness comparable to that of alpha particles. In this paper, we present a simple model and corresponding measurements to assess the energy deposited near the site of the radiopharmaceuticals in TRT. As an example, a calculation is performed for the decay of a single 125I radionuclide surrounded by a 1-nm-radius spherical shell of cytosine molecules using the energy spectrum of LEEs emitted by 125I along with their stopping cross sections between 0 and 18 eV. The dose absorbed by the cytosine shell, which occupies a volume of 4 nm3, is extremely high. It amounts to 79 kGy per decay of which 3%, 39%, and 58% is attributed to vibrational excitations, electronic excitations, and ionization processes, respectively.

20.
J Chem Phys ; 137(11): 115103, 2012 Sep 21.
Article in English | MEDLINE | ID: mdl-22998289

ABSTRACT

The absolute cross sections (CSs) for vibrational excitations of cytosine by electron impact between 0.5 and 18 eV were measured by electron-energy loss (EEL) spectroscopy of the molecule deposited at monolayer coverage on an inert Ar substrate. The vibrational energies compare to those that have been reported from IR spectroscopy of cytosine isolated in Ar matrix, IR and Raman spectra of polycrystalline cytosine, and ab initio calculation. The CSs for the various H bending modes at 142 and 160 meV are both rising from their energy threshold up to 1.7 and 2.1 × 10(-17) cm(2) at about 4 eV, respectively, and then decrease moderately while maintaining some intensity at 18 eV. The latter trend is displayed as well for the CS assigned to the NH(2) scissor along with bending of all H at 179 meV. This overall behavior in electron-molecule collision is attributed to direct processes such as the dipole, quadrupole, and polarization contributions, etc. of the interaction of the incident electron with a molecule. The CSs for the ring deformation at 61 meV, the ring deformation with N-H symmetric wag at 77 meV, and the ring deformations with symmetric bending of all H at 119 meV exhibit common enhancement maxima at 1.5, 3.5, and 5.5 eV followed by a broad hump at about 12 eV, which are superimposed on the contribution due to the direct processes. At 3.5 eV, the CS values for the 61-, 77-, and 119-meV modes reach 4.0, 3.0, and 4.5 × 10(-17) cm(2), respectively. The CS for the C-C and C-O stretches at 202 meV, which dominates in the intermediate EEL region, rises sharply until 1.5 eV, reaches its maximum of 5.7 × 10(-17) cm(2) at 3.5 eV and then decreases toward 18 eV. The present vibrational enhancements, correspond to the features found around 1.5 and 4.5 eV in electron transmission spectroscopy (ETS) and those lying within 1.5-2.1 eV, 5.2-6.8 eV, and 9.5-10.9 eV range in dissociative electron attachment (DEA) experiments with cytosine in gas phase. While the ETS features are ascribed to shape resonances associated with the electron occupation of the second and third antibonding π-orbitals of the molecule in its ground state, the correspondence with DEA features suggests the existence of common precursor anion states decaying with certain probabilities into the vibrationally excited ground state.


Subject(s)
Cytosine/chemistry , Electrons , Spectroscopy, Electron Energy-Loss , Vibration
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