RESUMO
Autoionization spectra of CH2Cl2 and CD2Cl2 molecules after Cl 2p excitation are studied. The two molecular and atomic Auger transitions are examined and assigned. The contribution of atomic Auger transitions is lower in the deuterated molecule. In addition, to support the presence of the ultrafast dissociation mechanism in the dichloromethane molecule, a series of high-level ab initio quantum mechanical calculations were performed at multiconfigurational self-consistent field (MCSCF) and multireference configuration interaction (MRCI) levels of theory. Minimum energy pathways for the dissociation of the dichloromethane molecule have been calculated by taking into account the spin-orbit splitting between the singlet and triplet transitions in the Cl 2p edge.
RESUMO
The dynamics of the photofragmentation pathways of tetrachloroethylene with photon energies from 15 up to 250 eV encompassing the Cl 2p edge is presented. In order to distinguish the fragmentation channels, the ionic fragments were separated according to their mass-to-charge ratio, measured in coincidence with the photoelectrons, and collected as a function of the incident photon energy. Distinct minima or maxima are found in the partial ion yield in the region between 40 and 50 eV. These features are believed to be associated with the Cooper minimum which results from a molecular orbital with a strong atomic 3p subshell character. In the shallow core region, some fragmentation patterns are considered in terms of fast fragmentation of the C2Cl4 molecule, despite the heavy mass of its fragments. In the present case, the fast fragmentation is favored by the very strong antibonding character of the LUMO, understandable in the frame of the core equivalent model for halogen-containing molecules. In addition, ab initio calculations were performed to obtain states at the Cl 2p edge. Singlet and triplet states at the Cl 2p edge of the C2Cl4 molecule, corresponding to the Cl(2p â 9b1u*) and Cl(2p â 8b2u*) transitions, were calculated in order to form a basis set of molecular states from which the spin-orbit splitting can be inferred. Multiconfigurational self-consistent field (MCSCF) calculation followed by multireference configuration interaction (MRCI) was the method chosen to establish a set of singlet and triplet states at the 2p excitation edge in addition to the ground state.
RESUMO
BACKGROUND: The Huntington disease (HD) CAG repeat exhibits dramatic instability when transmitted to subsequent generations. The instability of the HD disease allele in male intergenerational transmissions is reflected in the variability of the CAG repeat in DNA from the sperm of male carriers of the HD gene. RESULTS: In this study, we used a collection of 112 sperm DNAs from male HD gene-positive members of a large Venezuelan cohort to investigate the factors associated with repeat instability. We confirm previous observations that CAG repeat length is the strongest predictor of repeat-length variability in sperm, but we did not find any correlation between CAG repeat instability and either age at the time of sperm donation or affectedness status. We also investigated transmission instability for 184 father-offspring and 311 mother-offspring pairs in this Venezuelan pedigree. Repeat-length changes were dependent upon the sex of the transmitting parent and parental CAG repeat length but not parental age or birth order. Unexpectedly, in maternal transmissions, repeat-length changes were also dependent upon the sex of the offspring, with a tendency for expansion in male offspring and contraction in female offspring. CONCLUSION: Significant sibling-sibling correlation for repeat instability suggests that genetic factors play a role in intergenerational CAG repeat instability.
Assuntos
Doença de Huntington/genética , Instabilidade de Microssatélites , Repetições Minissatélites/genética , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Adolescente , Adulto , Ordem de Nascimento , Criança , Pai , Feminino , Heterozigoto , Humanos , Proteína Huntingtina , Doença de Huntington/epidemiologia , Masculino , Mães , Pais , Linhagem , Fatores Sexuais , Irmãos , Espermatozoides/química , Venezuela/epidemiologiaAssuntos
Humanos , Articulação do Dedo do Pé/anatomia & histologia , Articulação do Dedo do Pé/fisiopatologia , Artrodese/métodos , Artrodese/tendências , Nervo Fibular/anatomia & histologia , Nervo Fibular/fisiopatologia , Nervo Fibular/lesões , Neuropatia Tibial/diagnóstico , Neuropatia Tibial/fisiopatologia , Neuropatia Tibial/reabilitação , Tendão do Calcâneo/anatomia & histologia , Tendão do Calcâneo/cirurgia , Tendão do Calcâneo/fisiopatologia , Reabsorção Óssea/reabilitaçãoRESUMO
The number of registered leprosy patients world-wide has decreased dramatically after extensive application of WHO recommended Multiple Drug Therapy (MDT). The annual number of new cases has, however, been almost unchanged in several populations, indicating that the infection is still present at community level. Nasal carriage of Mycobacterium leprae DNA was studied in Lega Robi village in Ethiopia. MDT had been applied for more than ten years, and 718 residents over 5 years old were eligible for the study. During the first survey nasal swab samples were collected from 664 (92.5%) individuals. The results of a Peptide Nucleic Acid-ELISA test for M. leprae DNA interpreted by stringent statistical criteria were available for 589 (88.7%) subjects. Thirty-five (5.9%) individuals without clinical signs of leprosy were positive for M. leprae DNA. Seven PCR positive individuals lived in a household where one or two other members were also positive for M. leprae DNA. During a second survey 8 (46%) of 175 interpretable PNA-ELISA tests were positive. Of 137 individuals tested twice, only two were positive on both occasions whereas 10 were PCR positive only once. The study confirms the widespread distribution of M. leprae DNA in healthy individuals. The feasibility of curbing possible transmission of subclinical infection needs further consideration.
Assuntos
Feminino , Masculino , Adolescente , Adulto , Idoso , Criança , Humanos , Pessoa de Meia-Idade , DNA Bacteriano , Ensaio de Imunoadsorção Enzimática , Etiópia , Hanseníase , Mycobacterium leprae , Nariz , Reação em Cadeia da PolimeraseRESUMO
Sixty nine samples of maize were collected from pre-harvest standing crops and on-farm storage facilities from 52 smallholder farms located within 4 regions of Honduras during October 1992 and November 1993. Samples were visually assessed for insect damage and fungal spoilage, and the mycoflora quantified on artificial media. The major components of the ear rot complex were: Fusarium moniliforme, F. moniliforme var. subglutinans, Penicillium species, Stenocarpella maydis, S. macrospora and Acremonium spp. Representative samples were also assayed for mycotoxin content. Fumonisin B1 was detected in all 24 samples tested at levels of between 68-6,555 (micrograms/kg), and aflatoxin was detected in 2 samples heavily contaminated with Aspergillus flavus. Moniliformin and tenuazonic acid were not detected in the samples tested. The implications of these findings for human and livestock health risk are discussed, together with possible strategies for controlling these pathogens.
Assuntos
Microbiologia de Alimentos , Fumonisinas , Fungos Mitospóricos/isolamento & purificação , Micotoxinas/análise , Zea mays/microbiologia , Aflatoxinas/análise , Ciclobutanos/análise , Honduras , Ácido Tenuazônico , Zea mays/químicaRESUMO
We describe two infants with congenital myotonic dystrophy that was complicated by persistent pulmonary hypertension. Both infants died of respiratory insufficiency that was unresponsive to ventilatory and pharmacologic support. One of the two infants was supported with extracorporeal membrane oxygenation before the diagnosis of congenital myotonic dystrophy was made.
Assuntos
Distrofia Miotônica/congênito , Síndrome da Persistência do Padrão de Circulação Fetal/complicações , Oxigenação por Membrana Extracorpórea , Evolução Fatal , Feminino , Humanos , Recém-Nascido , Masculino , Distrofia Miotônica/complicações , Distrofia Miotônica/diagnóstico , Síndrome da Persistência do Padrão de Circulação Fetal/terapiaAssuntos
Doença de Huntington/história , Sequências Repetitivas de Ácido Nucleico , Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 4 , Clonagem Molecular , Troca Genética , Marcadores Genéticos , Haplótipos/genética , História do Século XIX , História do Século XX , Humanos , Doença de Huntington/epidemiologia , Doença de Huntington/genética , Doença de Huntington/patologia , Desequilíbrio de Ligação , Pessoa de Meia-Idade , Linhagem , Venezuela/epidemiologiaRESUMO
A 14-year-old girl, who was a renal transplant recipient, developed Candida tropicalis peritonitis during peritoneal dialysis and immunosuppressive and broad-spectrum antibiotic therapy. Therapeutic cure of the peritonitis followed a ten-day course of amphotericin B administered solely by peritoneal lavage.