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1.
Ir Vet J ; 72: 10, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695907

RESUMO

The objective of this study was to identify the prognostic value for survival of blood parameters in the immediate post-caesarean surgery period in kids born from pregnancy toxaemia (PT) goats. This study involved 10 PT goats, in which a caesarean surgery was performed. Twenty-five kids were born after caesarean surgery of which 16 survived. A blood sample was collected from the jugular vein of the 10 goats and from the kids immediately after caesarean surgery (within 15 min). There were differences between the kids that survived and the kids that did not survive concerning the blood levels of pH (7.22 vs 7.00), base excess (- 9 vs - 18 mmol/L), pCO2 (46 vs 62 mmHg) and L-lactate (5.6 vs 16 mmol/L). Maternal ketoacidosis due to PT has a negative impact on the survival rate of the offspring. This appears to be associated to a metabolic acidosis of the offspring. However, the only blood parameter in which there was a strong association between the maternal and newborn kids was blood urea nitrogen (r = 0.97).

2.
Proc Biol Sci ; 285(1871)2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29367389

RESUMO

The mating behaviour of many mosquito species is mediated essentially by sound: males follow and mate with a female mid-flight by detecting and tracking the whine of her flight-tones. The stereotypical rapid frequency modulation (RFM) male behaviour, initiated in response to the detection of the female's flight-tones, has provided a means of investigating these auditory mechanisms while males are free-flying. Mosquitoes hear with their antennae, which vibrate to near-field acoustic excitation. The antennae generate nonlinear vibrations (distortion products, DPs) at frequencies that are equal to the difference between the two simultaneously presented tones, e.g. the male and female flight-tones, which are detected by mechanoreceptors in the auditory Johnston's organ (JO) at the base of the antenna. Recent studies indicated the male mosquito's JO is tuned not to the female flight-tone, but to the frequency difference between the male and female flight-tones. To test the hypothesis that mosquitoes detect this frequency difference, Culex quinquefasciatus males were presented simultaneously with a female flight-tone and a masking tone, which should suppress the male's RFM response to sound. The free-flight behavioural and in vivo electrophysiological experiments revealed that acoustic masking suppresses the RFM response to the female's flight-tones by attenuating the DPs generated in the nonlinear vibration of the antennae. These findings provide direct evidence in support of the hypothesis that male mosquitoes detect females when both are in flight through difference tones generated in the vibrations of their antennae owing to the interaction between their own flight-tones and those of a female.


Assuntos
Percepção Auditiva , Culex/fisiologia , Comportamento Sexual Animal , Estimulação Acústica , Animais , Feminino , Masculino , Mecanorreceptores/fisiologia , Vibração
3.
J Antimicrob Chemother ; 72(4): 1014-1020, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27999045

RESUMO

Objectives: We investigated the epidemiological, clinical, microbiological and genetic characteristics of linezolid-resistant (LZR) Staphylococcus capitis isolates from French ICUs, and compared them with LZR S. capitis isolates from other European countries. Methods: All LZR isolates were subjected to antimicrobial susceptibility testing (AST) and the presence of cfr and optrA genes as well as mutations in the 23S rRNA and ribosomal proteins were investigated using specific PCR with sequencing. The genetic relationship between isolates was investigated using PFGE and WGS. Epidemiological data concerning LZR S. capitis were collected retrospectively in French microbiology laboratories. Results: Twenty-one LZR isolates were studied: 9 from France, 11 from Greece and 1 from Finland. All were resistant to methicillin and aminoglycosides. In addition, this unusual AST profile was identified in S. capitis isolates from seven French hospitals, and represented up to 12% of the S. capitis isolates in one centre. A G2576T mutation in 23S rRNA was identified in all isolates; cfr and optrA genes were absent. All isolates belonged to the same clone on the basis of their PFGE profiles, whatever their geographical origin. WGS found at most 212 SNPs between core genomes of the LZR isolates. Conclusions: We identified and characterized an LZR S. capitis clone disseminated in three European countries, harbouring the same multiple resistance and a G2576T mutation in the 23S rRNA. The possible unrecognized wider distribution of this clone, belonging to a species classically regarded as a low-virulence skin colonizer, is of major concern not least because of the increasing use of oxazolidinones.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Genótipo , Linezolida/farmacologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Adulto , Idoso , Análise por Conglomerados , Eletroforese em Gel de Campo Pulsado , Finlândia/epidemiologia , França/epidemiologia , Genes Bacterianos , Genoma Bacteriano , Grécia/epidemiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Mutação , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Adulto Jovem
4.
J Intellect Disabil Res ; 61(8): 755-765, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28585394

RESUMO

BACKGROUND: People with Down syndrome (DS) usually display reduced physical fitness (aerobic capacity, muscle strength and abnormal body composition), motor proficiency impairments (balance and postural control) and physical functional limitations. Exergames can be an appealing alternative to enhance exercise engagement and compliance, whilst improving physical fitness and motor function. This study aims to analyse the effects of a Wii-based exercise program on physical fitness, functional mobility and motor proficiency of adults with DS. METHODS: Twenty-seven adults with DS were randomly allocated to an experimental group (Wii; n = 14) or control group (n = 13). Participants in the experimental group completed a 2-month Wii-based exercise program, with three 1-h sessions per week that included training games for aerobic endurance, balance and isometric strength. Participants completed assessments regarding anthropometric measures, physical fitness, functional mobility and motor proficiency. RESULTS: Mixed ANOVA analysis showed a significant group by time interaction for aerobic endurance, explosive leg power and flexibility. Independent samples t-test for change scores indicated significant between-group differences favouring the experimental group regarding speed of limb movement, trunk strength and functional mobility, as well as a trend towards significance on body weight. Mann-Whitney's U test for change scores demonstrated between-group differences favouring the experimental group for visceral fat as well as running speed and agility. Large within-group effect sizes were observed for explosive leg power (d = 1.691), body weight (d = 1.281), functional mobility (d = 1.218), aerobic endurance (d = 1.020), speed of limb movement (d = 0.867) and flexibility (d = 0.818) in the experimental group. CONCLUSIONS: Our findings suggest that Wii-based exercise can be an effective tool to improve physical fitness, functional mobility and motor proficiency of adults with DS, including crucial measures such as aerobic capacity and lower limb strength. Exergames using Wii Fit or other equipment can be appealing alternatives for adults with DS to engage in regular physical activity, preventing sedentary behaviour and decreasing the risk to develop cardiovascular diseases.


Assuntos
Síndrome de Down/reabilitação , Terapia por Exercício/métodos , Avaliação de Resultados em Cuidados de Saúde , Terapia Assistida por Computador/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Jogos de Vídeo
5.
J Viral Hepat ; 23(1): 32-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26189719

RESUMO

Chronic hepatitis C virus (HCV) infection may cause kidney injury, particularly in the setting of cryoglobulinemia or cirrhosis; however, few studies have evaluated the epidemiology of acute kidney injury in patients with HCV. We aimed to describe national temporal trends of incidence and impact of severe acute kidney injury (AKI) requiring renal replacement 'dialysis-requiring AKI' in hospitalized adults with HCV. We extracted our study cohort from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project using data from 2004 to 2012. We defined HCV and dialysis-requiring acute kidney injury based on previously validated ICD-9-CM codes. We analysed temporal changes in the proportion of hospitalizations complicated by dialysis-requiring AKI and utilized survey multivariable logistic regression models to estimate its impact on in-hospital mortality. We identified a total of 4,603,718 adult hospitalizations with an associated diagnosis of HCV from 2004 to 2012, of which 51,434 (1.12%) were complicated by dialysis-requiring acute kidney injury. The proportion of hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly from 0.86% in 2004 to 1.28% in 2012. In-hospital mortality was significantly higher in hospitalizations complicated by dialysis-requiring acute kidney injury vs those without (27.38% vs 2.95%; adjusted odds ratio: 2.09; 95% confidence interval: 1.74-2.51). The proportion of HCV hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly between 2004 and 2012. Similar to observations in the general population, dialysis-requiring acute kidney injury was associated with a twofold increase in odds of in-hospital mortality in adults with HCV. These results highlight the burden of acute kidney injury in hospitalized adults with HCV infection.


Assuntos
Injúria Renal Aguda/terapia , Hepatite C Crônica/virologia , Hospitalização/estatística & dados numéricos , Diálise Renal/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Comorbidade , Feminino , Hepacivirus/isolamento & purificação , Mortalidade Hospitalar , Humanos , Lactente , Recém-Nascido , Pacientes Internados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença , Estados Unidos , Adulto Jovem
6.
J Evol Biol ; 29(6): 1151-67, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26969850

RESUMO

There is considerable evidence for an adaptive role of inversions, but how their genetic content evolves and affects the subsequent evolution of chromosomal polymorphism remains controversial. Here, we track how life-history traits, chromosomal arrangements and 22 microsatellites, within and outside inversions, change in three replicated populations of Drosophila subobscura for 30 generations of laboratory evolution since founding from the wild. The dynamics of fitness-related traits indicated adaptation to the new environment concomitant with directional evolution of chromosomal polymorphism. Evidence of selective changes in frequency of inversions was obtained for seven of 23 chromosomal arrangements, corroborating a role for inversions in adaptation. The evolution of linkage disequilibrium between some microsatellites and chromosomes suggested that adaptive changes in arrangements involved changes in their genetic content. Several microsatellite alleles increased in frequency more than expected by drift in targeted inversions in all replicate populations. In particular, there were signs of selection in the O3+4 arrangement favouring a combination of alleles in two loci linked to the inversion and changing along with it, although the lack of linkage disequilibrium between these loci precludes epistatic selection. Seven other alleles increased in frequency within inversions more than expected by drift, but were not in linkage disequilibrium with them. Possibly these alleles were hitchhiking along with alleles under selection that were not specific to those inversions. Overall, the selection detected on the genetic content of inversions, despite limited coverage of the genome, suggests that genetic changes within inversions play an important role in adaptation.


Assuntos
Inversão Cromossômica , Drosophila/genética , Desequilíbrio de Ligação , Adaptação Fisiológica , Alelos , Animais , Cromossomos , Polimorfismo Genético
7.
J Phys Chem A ; 120(23): 4079-88, 2016 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-27213224

RESUMO

Condensed clusters of hydrolyzed methyltrimethoxysilane (MTMS) were studied using two complementary approaches: (i) Fourier transform infrared (FTIR) spectroscopy was applied along with the hydrolysis and condensation stages of a sol-gel process from the condensation of colloidal suspension of nanoparticles to the solid phase of bulk material; (ii) density functional theory calculations of energies, structural and vibrational data of pertinent MTMS hydrolysis products, specifically, methylsilanetriol-based species with different number of silicon atoms (from two to eight atoms) and different structures/conformations (linear, cyclic, and cage, in a total of 13 structures), were performed at B3LYP/6-311+G(d,p) level of theory. The calculated infrared spectra show two distinct Si-O-Si stretch vibration bands for models of caged structures. The higher-frequency IR band at ca. 1120 cm(-1) is derived from the antisymmetric Si-O-Si stretch vibration mode, while the lower-frequency band at 1035 cm(-1) is due to the symmetric Si-O-Si stretch and is characteristic of the cyclic clusters, being absent in highly symmetric cage structures. The calculated versus the experimental FTIR spectra of poly(methylsilsesquioxane) (PMSQ) dried aerogel in KBr pellet show that cage/cyclic-like structures prevail over ladder structures (linear) in actual PMSQ.

8.
J Antimicrob Chemother ; 70(11): 3027-31, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26203181

RESUMO

OBJECTIVES: The Staphylococcus capitis clone NRCS-A has recently been described as a frequent cause of late-onset sepsis (LOS) in pre-term neonates worldwide. Representatives of this clone exhibit non-susceptibility to vancomycin, the first-line agent used in LOS. Cases of prolonged S. capitis LOS despite vancomycin treatment have been reported. We investigated whether NRCS-A strains exhibit faster adaptation to vancomycin pressure as compared with other staphylococci. METHODS: Strains of S. capitis NRCS-A, S. capitis non-NRCS-A and Staphylococcus epidermidis (n = 2 each, all with vancomycin MICs ≤2 mg/L) and the prototype vancomycin-heteroresistant Staphylococcus aureus Mu3 were subcultured daily for 15 days with 0.25-32 mg/L vancomycin. Regression coefficients of daily log2 MICs on time were used to estimate the kinetics of resistance development. Changes in bacterial cell-wall thickness were measured by transmission electron microscopy. To assess the stability of resistance and the emergence of cross-resistance, vancomycin, teicoplanin, daptomycin and linezolid MICs were measured before and after vancomycin treatment, as well as after nine additional subcultures without antibiotics. RESULTS: All strains developed a stable resistance to vancomycin, but this occurred significantly faster in S. capitis NRCS-A than in S. capitis non-NRCS-A (P < 0.001) and other species (P < 0.0001). Vancomycin resistance in S. capitis NRCS-A was associated with significant cell-wall thickening and an increase in MICs of daptomycin and teicoplanin, but not linezolid. CONCLUSIONS: S. capitis NRCS-A rapidly adapts to vancomycin pressure as compared with potential niche competitors, a feature that might contribute to its success in neonatal ICUs where vancomycin is widely prescribed.


Assuntos
Adaptação Biológica , Antibacterianos/farmacologia , Sepse/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Vancomicina/farmacologia , Antibacterianos/uso terapêutico , Parede Celular/ultraestrutura , Humanos , Recém-Nascido , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Sepse/tratamento farmacológico , Inoculações Seriadas , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus/crescimento & desenvolvimento , Staphylococcus/ultraestrutura , Vancomicina/uso terapêutico
9.
J Evol Biol ; 28(12): 2163-74, 2015 12.
Artigo em Inglês | MEDLINE | ID: mdl-26302686

RESUMO

Clinal variation is one of the most emblematic examples of the action of natural selection at a wide geographical range. In Drosophila subobscura, parallel clines in body size and inversions, but not in wing shape, were found in Europe and South and North America. Previous work has shown that a bottleneck effect might be largely responsible for differences in wing trait-inversion association between one European and one South American population. One question still unaddressed is whether the associations found before are present across other populations of the European and South American clines. Another open question is whether evolutionary dynamics in a new environment can lead to relevant changes in wing traits-inversion association. To analyse geographical variation in these associations, we characterized three recently laboratory founded D. subobscura populations from both the European and South American latitudinal clines. To address temporal variation, we also characterized the association at a later generation in the European populations. We found that wing size and shape associations can be generalized across populations of the same continent, but may change through time for wing size. The observed temporal changes are probably due to changes in the genetic content of inversions, derived from adaptation to the new, laboratory environment. Finally, we show that it is not possible to predict clinal variation from intrapopulation associations. All in all this suggests that, at least in the present, wing traits-inversion associations are not responsible for the maintenance of the latitudinal clines in wing shape and size.


Assuntos
Drosophila/fisiologia , Asas de Animais/crescimento & desenvolvimento , Animais , Inversão Cromossômica , Drosophila/genética
11.
J Evol Biol ; 27(12): 2727-38, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25430492

RESUMO

Chromosomal inversions are present in a wide range of animals and plants, having an important role in adaptation and speciation. Although empirical evidence of their adaptive value is abundant, the role of different processes underlying evolution of chromosomal polymorphisms is not fully understood. History and selection are likely to shape inversion polymorphism variation to an extent yet largely unknown. Here, we perform a real-time evolution study addressing the role of historical constraints and selection in the evolution of these polymorphisms. We founded laboratory populations of Drosophila subobscura derived from three locations along the European cline and followed the evolutionary dynamics of inversion polymorphisms throughout the first 40 generations. At the beginning, populations were highly differentiated and remained so throughout generations. We report evidence of positive selection for some inversions, variable between foundations. Signs of negative selection were more frequent, in particular for most cold-climate standard inversions across the three foundations. We found that previously observed convergence at the phenotypic level in these populations was not associated with convergence in inversion frequencies. In conclusion, our study shows that selection has shaped the evolutionary dynamics of inversion frequencies, but doing so within the constraints imposed by previous history. Both history and selection are therefore fundamental to predict the evolutionary potential of different populations to respond to global environmental changes.


Assuntos
Adaptação Biológica/genética , Evolução Biológica , Inversão Cromossômica/genética , Drosophila/genética , Variação Genética , Modelos Genéticos , Seleção Genética , Animais , Mudança Climática , França , Países Baixos , Portugal
12.
Antimicrob Agents Chemother ; 57(12): 6354-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24060879

RESUMO

Multiresistant Staphylococcus capitis pulsotype NRCS-A has been reported to be a major pathogen causing nosocomial bacteremia in preterm infants. We report that the NRCS-A strain CR01 harbors a novel 60.9-kb composite staphylococcal cassette chromosome mec (SCCmec) element, composed of an SCCmec with strong homologies to Staphylococcus aureus ST398 SCCmec and of an SCCcad/ars/cop harboring resistance genes for cadmium, arsenic, and copper. Whole-genome-based comparisons of published S. capitis strains suggest that strain CR01 acquired the two elements independently.


Assuntos
Staphylococcus aureus Resistente à Meticilina/genética , Sepse/microbiologia , Arsênio/farmacologia , Cádmio/farmacologia , Cromossomos Bacterianos/genética , Cobre/farmacologia , Feminino , Humanos , Recém-Nascido , Masculino
13.
Infection ; 41(3): 695-700, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23124908

RESUMO

A 61-year-old man presented with fever and altered mental status. He was intubated for respiratory distress and was found to have multilobar pneumonia for which antibiotic therapy was instituted. However, his mental status continued to deteriorate despite appropriate antibiotic therapy for his pneumonia. The results from lumar puncture revealed meningitis and endocarditis was evident on a trans-esophageal echocardiogram. His blood and respiratory cultures grew Streptococcus pneumoniae. The patient was diagnosed with Austrian syndrome. After appropriate changes to his antibiotic regimen and an aortic valve replacement, he recovered and was discharged.


Assuntos
Bacteriemia/diagnóstico , Endocardite Bacteriana/diagnóstico , Meningite Pneumocócica/diagnóstico , Pneumonia Pneumocócica/diagnóstico , Streptococcus pneumoniae/isolamento & purificação , Antibacterianos/uso terapêutico , Valva Aórtica/cirurgia , Bacteriemia/complicações , Bacteriemia/microbiologia , Bacteriemia/patologia , Sangue/microbiologia , Endocardite Bacteriana/complicações , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/patologia , Humanos , Masculino , Meningite Pneumocócica/complicações , Meningite Pneumocócica/microbiologia , Meningite Pneumocócica/patologia , Pessoa de Meia-Idade , Pneumonia Pneumocócica/complicações , Pneumonia Pneumocócica/microbiologia , Pneumonia Pneumocócica/patologia , Sistema Respiratório/microbiologia , Resultado do Tratamento
14.
J Evol Biol ; 25(12): 2607-22, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23110657

RESUMO

Most founding events entail a reduction in population size, which in turn leads to genetic drift effects that can deplete alleles. Besides reducing neutral genetic variability, founder effects can in principle shift additive genetic variance for phenotypes that underlie fitness. This could then lead to different rates of adaptation among populations that have undergone a population size bottleneck as well as an environmental change, even when these populations have a common evolutionary history. Thus, theory suggests that there should be an association between observable genetic variability for both neutral markers and phenotypes related to fitness. Here, we test this scenario by monitoring the early evolutionary dynamics of six laboratory foundations derived from founders taken from the same source natural population of Drosophila subobscura. Each foundation was in turn three-fold replicated. During their first few generations, these six foundations showed an abrupt increase in their genetic differentiation, within and between foundations. The eighteen populations that were monitored also differed in their patterns of phenotypic adaptation according to their immediately ancestral founding sample. Differences in early genetic variability and in effective population size were found to predict differences in the rate of adaptation during the first 21 generations of laboratory evolution. We show that evolution in a novel environment is strongly contingent not only on the initial composition of a newly founded population but also on the stochastic changes that occur during the first generations of colonization. Such effects make laboratory populations poor guides to the evolutionary genetic properties of their ancestral wild populations.


Assuntos
Adaptação Biológica , Evolução Biológica , Drosophila/genética , Efeito Fundador , Animais , Drosophila/crescimento & desenvolvimento , Feminino , Repetições de Microssatélites , Dados de Sequência Molecular , Fenótipo , Densidade Demográfica , Análise de Componente Principal
15.
Langmuir ; 28(20): 7646-56, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22545667

RESUMO

Here, we present new antimicrobial nanoparticles based on silica nanoparticles (SNPs) coated with a quaternary ammonium cationic surfactant, didodecyldimethylammonium bromide (DDAB). Depending on the initial concentration of DDAB, SNPs immobilize between 45 and 275 µg of DDAB per milligram of nanoparticle. For high concentrations of DDAB adsorbed to SNP, a bilayer is formed as confirmed by zeta potential measurements, thermogravimetry, and diffuse reflectance infrared Fourier transform (DRIFT) analyses. Interestingly, these nanoparticles have lower minimal inhibitory concentrations (MIC) against bacteria and fungi than soluble surfactant. The electrostatic interaction of the DDAB with the SNP is strong, since no measurable loss of antimicrobial activity was observed after suspension in aqueous solution for 60 days. We further show that the antimicrobial activity of the nanoparticle does not require the leaching of the surfactant from the surface of the NPs. The SNPs may be immobilized onto surfaces with different chemistry while maintaining their antimicrobial activity, in this case extended to a virucidal activity. The versatility, relative facility in preparation, low cost, and large antimicrobial activity of our platform makes it attractive as a coating for large surfaces.


Assuntos
Antifúngicos/farmacologia , Nanopartículas/química , Dióxido de Silício/química , Dióxido de Silício/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antivirais/química , Antivirais/farmacologia , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Compostos de Amônio Quaternário/química , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Tensoativos/química , Fatores de Tempo , Água/química
16.
J Chem Phys ; 134(12): 124505, 2011 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-21456674

RESUMO

Poly(ester amide)s (PEAs) are lacking in structural and spectroscopic information. This paper reports a structural and spectroscopic characterization of N(α)-benzoyl-L-argininate ethyl ester chloride (BAEEH(+)·Cl(-)), an important amino acid derivative and an adequate PEAs' model compound. Crystals of BAEEH(+)·Cl(-) obtained by slow evaporation in an ethanol∕water mixture were studied by different complementary techniques. X-ray analysis shows that BAEEH(+)·Cl(-) crystallizes in the chiral space group P2(1). There are two symmetry independent cations (and anions) in the unit cell. The two cations have different conformations: in one of them, the angle between the least-squares planes of the phenyl ring and the guanidyl group is 5.1(2)°, and in the other the corresponding angle is 13.3(2)°. There is an extensive network of H-bonds that assembles the ions in layers parallel to the ab plane. Experimental FT-IR and Raman spectra of BAEEH(+)·Cl(-) were recorded at room temperature in the 3750-600 cm(-1) and 3380-100 cm(-1) regions, respectively, and fully assigned. Both structural and spectroscopic analysis were supported by quantum chemistry calculations based on different models (in vacuo and solid-state DFT simulations).


Assuntos
Arginina/análogos & derivados , Amidas/química , Arginina/química , Modelos Moleculares , Poliésteres/química , Teoria Quântica , Espectrofotometria Infravermelho , Análise Espectral Raman , Difração de Raios X
17.
Infect Dis Now ; 51(6): 540-546, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34198001

RESUMO

OBJECTIVE: We aimed to report a community outbreak of an uncommon methicillin-resistant Staphylococcus aureus (MRSA) originating in a maternity ward. PATIENTS AND METHODS: Cases were defined by epidemiological, clinical, and microbiological investigations. Microbiological investigations included phenotypic analysis, molecular typing, and whole-genome sequencing. To control the outbreak, we applied both national recommendations to prevent in-hospital transmission and the French High Council for Public Health guidelines on the management of community-acquired MRSA infections. RESULTS: Between March and July 2016, seven patients with MRSA infections were identified: six skin and soft tissue infections and one pulmonary infection, including six microbiologically confirmed infections. Infections occurred in community settings, but a link with the same maternity ward was found for all patients. All MRSA strains had a t690 spa type, were tetracycline-resistant, and produced Panton-Valentine leukocidin. All isolates belonged to the sequence type 88 (ST88). CONCLUSION: This outbreak highlights the largely underestimated risk of healthcare-associated infections in maternity wards. Healthcare workers should be aware of the importance of standard hygiene precautions and use of alcohol-based hand sanitizers for neonates and mothers.


Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções dos Tecidos Moles , Infecções Estafilocócicas , Infecções Comunitárias Adquiridas/epidemiologia , Feminino , Hospitais , Humanos , Recém-Nascido , Staphylococcus aureus Resistente à Meticilina/genética , Gravidez , Infecções Estafilocócicas/tratamento farmacológico
18.
Phys Med ; 25(3): 154-9, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19299178

RESUMO

Dose homogeneity in head and neck tumour irradiation is a challenging task for conventional radiotherapy due to large anatomic contour irregularities and tissue heterogeneities in irradiation volumes. We present a simple technique based on the omni-wedge concept which uses superimposed fields, orthogonally wedged, to improve target-volumes homogeneity in head and neck tumour irradiation. The routine implementation of this technique is straightforward and easy to achieve with standard radiotherapy equipment and treatment planning software. Our five-year experience in the clinical implementation of this technique is presented.


Assuntos
Algoritmos , Neoplasias de Cabeça e Pescoço/radioterapia , Modelos Biológicos , Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Simulação por Computador , Humanos , Dosagem Radioterapêutica
19.
J Phys Chem A ; 112(15): 3432-43, 2008 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-18341311

RESUMO

This paper presents an overview of recent progress in spectroscopic studies of the energetic nitroimine 4,6-bis(nitroimino)-1,3,5-triazinan-2-one (DNAM), based on experimental and theoretical data. The following topics are considered: variable temperature FTIR spectroscopy (4000-400 cm(-1)) applied to the study of natural and isotopically substituted (deuterated) samples aiming to obtain a successful vibrational assignment of the spectra and to investigate H-bonding interactions; extensive theoretical work based on accurate quantum chemical calculations (ab initio MP2 and DFT/B3LYP; harmonic and anharmonic vibrational calculations) to model and help interpreting the experimental findings, as well as to provide fundamental data on this simple prototype nitroimine that can be used as a starting point to the study of more complex related compounds. This work allowed us to reveal detailed features of the IR spectrum of the title compound, presenting, for the first time, plausible assignments.

20.
Sci Adv ; 4(12): eaav2794, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30525109

RESUMO

We present the first observational study of the onset and evolution of solar flare turbulence in the lower solar atmosphere on an unprecedented time scale of 1.7 s using the Interface Region Imaging Spectrograph observing plasma at a temperature of 80,000 K. At this time resolution, nonthermal spectral line broadening, indicating turbulent velocity fluctuations, precedes the flare onset at this temperature and is coincident with net blue-shifts. The broadening decreases as the flare brightens and then oscillates with a period of ~10 s. These observations are consistent with turbulence in the lower solar atmosphere at the flare onset, heating that region as it dissipates. This challenges the current view of energy release and transport in the standard solar flare model, suggesting that turbulence partly heats the lower atmosphere.

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