RESUMO
Altermagnetism is a recently identified magnetic symmetry class combining characteristics of conventional collinear ferromagnets and antiferromagnets, that were regarded as mutually exclusive, and enabling phenomena and functionalities unparalleled in either of the two traditional elementary magnetic classes. In this work we use symmetry, ab initio theory, and experiments to explore x-ray magnetic circular dichroism (XMCD) in the altermagnetic class. As a representative material for our XMCD study we choose α-MnTe with compensated antiparallel magnetic order in which an anomalous Hall effect has been already demonstrated. We predict and experimentally confirm a characteristic XMCD line shape for compensated moments lying in a plane perpendicular to the light propagation vector. Our results highlight the distinct phenomenology in altermagnets of this time-reversal symmetry breaking response, and its potential utility for element-specific spectroscopy and microscopy.
RESUMO
AIMS: This article presents models of artificial neural networks (ANN) employed to predict the biological activity of chemical compounds based of their structure. Regression and classification models were designed to determine antimicrobial properties of quaternary ammonium salts against Escherichia coli strain. METHODS AND RESULTS: The minimum inhibitory concentration microbial growth E. coli was experimentally determined by the serial dilution method for a series of 140 imidazole derivatives. Then, three-dimensional models for imidazole chlorides were constructed with computational chemistry methods which allowed to calculate molecular descriptors. The transformation of chemical information into a useful number is a main result of this operation. The designed regression and classification ANN models were characterized by a high predictive ability (classification accuracy was 95%, regression model: learning set R = 0.87, testing set R = 0.91, validation set R = 0.89). CONCLUSIONS: Artificial neural networks can be successfully used to find potential antimicrobial preparations. SIGNIFICANCE AND IMPACT OF THE STUDY: The neural networks are a very elaborate modelling technique, which allows not only to optimize and minimize labour costs but also to increase food safety.
Assuntos
Antibacterianos/farmacologia , Descoberta de Drogas/métodos , Escherichia coli/efeitos dos fármacos , Redes Neurais de Computação , Antibacterianos/química , Escherichia coli/crescimento & desenvolvimento , Imidazóis/química , Imidazóis/farmacologia , Testes de Sensibilidade Microbiana , Relação Quantitativa Estrutura-Atividade , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologiaRESUMO
Antibiotic resistance patterns of more than 120 000 clinical Escherichia coli isolates were retrospectively analysed. Isolates originated from both hospitalized patients and outpatients from the region of southeast Austria from 1998 to 2013. Except for amoxicillin/clavulanic acid, nitrofurantoin and piperacillin/tazobactam, all of the antibiotics analysed showed increasing proportions of resistant isolates over time, which were most prominent for ampicillin (from 25.4% in 1998 to 40% in 2013), cefotaxime (0.1% to 6.7%), ceftazidime (0.3% to 14.2%), ciprofloxacin (4.3% to 16.7%) and trimethoprim/sulfamethoxazole (14.6% to 24.8%). There was a marked increase in extended-spectrum ß-lactamase-positive isolates (0.1% to 6.3%) starting in 2005, with male patients and hospital-related patients showing a higher increase than female patients and outpatients. Proportions of resistant isolates for most antibiotics were generally higher for male patients and hospital-related patients. Amikacin, nitrofurantoin and trimethoprim/sulfamethoxazole showed a marked increase in resistance proportions among male subjects aged 10 to 19 years which were absent for female subjects, indicating a strong modulation potential of host characteristics.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores Sexuais , Adulto Jovem , beta-Lactamases/metabolismoRESUMO
OBJECTIVE: Currently, there are no clinical studies comparing different cement augmentation methods, and no clinical observational studies of a unipedicular approach. DESIGN, PATIENTS, INTERVENTIONS, MAIN OUTCOME MEASUREMENTS: The present study compared three commercially available vertebral augmentation systems: balloon kyphoplasty, vertebroplasty and shield kyphoplasty. The primary objective was to assess change in subjective severity of backache on a visual analog scale (VAS) and subjective improvement in quality of life on the Oswestry Disability Index (ODI), at a mean 6 months post-surgery. The secondary objective was to analyze current radiological imaging (X-ray, and in some cases CT) with regard to height restoration, cement distribution and leakage and recurrent fracture. RESULTS: Mean follow-up was 5.8 months. Mean preoperative Beck vertebral height index did not significantly differ between the three augmentation system groups (P>0.05). Comparing surgery time, fluoroscopy time and dose-area-product (cGy × cm(2)) showed a statistically significant difference (P<0.01) in favor of the vertebroplasty technique. Augmentation provided significant improvement in VAS pain assessment, but with no significant difference between augmentation systems. Results on the ODI were less pronounced, with significant improvement of 22% to 45%, but again without significant difference between augmentation systems. CONCLUSIONS: Overall, apart from mostly asymptomatic cement leakage, vertebroplasty could be considered as the surgical procedure of choice.
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Cateterismo/métodos , Cifoplastia/métodos , Vértebras Lombares/lesões , Fraturas por Osteoporose/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/lesões , Idoso , Feminino , Fluoroscopia , Seguimentos , Fraturas Espontâneas , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/complicações , Fraturas por Osteoporose/diagnóstico , Estudos Prospectivos , Fraturas da Coluna Vertebral/diagnóstico , Fraturas da Coluna Vertebral/etiologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , VertebroplastiaRESUMO
Cerebellar motor learning is required to obtain procedural skills. Studies have provided supportive evidence for a potential role of kinase-mediated long-term depression (LTD) at the parallel fiber to Purkinje cell synapse in cerebellar learning. Recently, phosphatases have been implicated in the induction of potentiation of Purkinje cell activities in vitro, but it remains to be shown whether and how phosphatase-mediated potentiation contributes to motor learning. Here, we investigated its possible role by creating and testing a Purkinje cell-specific knockout of calcium/calmodulin-activated protein-phosphatase-2B (L7-PP2B). The selective deletion of PP2B indeed abolished postsynaptic long-term potentiation in Purkinje cells and their ability to increase their excitability, whereas LTD was unaffected. The mutants showed impaired "gain-decrease" and "gain-increase" adaptation of their vestibulo-ocular reflex (VOR) as well as impaired acquisition of classical delay conditioning of their eyeblink response. Thus, our data indicate that PP2B may indeed mediate potentiation in Purkinje cells and contribute prominently to cerebellar motor learning.
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Calcineurina/metabolismo , Aprendizagem/fisiologia , Potenciação de Longa Duração/fisiologia , Atividade Motora/fisiologia , Células de Purkinje/fisiologia , Potenciais de Ação/fisiologia , Adaptação Psicológica/fisiologia , Animais , Calcineurina/genética , Cerebelo/citologia , Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Condicionamento Palpebral/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Camundongos , Camundongos Transgênicos , Neurônios/citologia , Neurônios/fisiologia , Células de Purkinje/citologia , Reflexo Vestíbulo-Ocular/fisiologia , Fatores de TempoRESUMO
Individual metabotropic glutamate (mGlu) receptor subtypes have been implicated in the pathophysiology of epileptic seizures, and are potential targets for novel antiepileptic drugs. Here, we examined the role of the mGlu4 receptor subtype in absence seizures using as models: (i) WAG/Rij rats, which develop spontaneous absence seizures after 2-3months of age; and (ii) mice treated with pentylentetrazole (PTZ, 30mg/kg, s.c.). Expression of mGlu4 receptors was enhanced in the reticular thalamic nucleus (RTN) of symptomatic WAG/Rij rats as compared with age-matched controls, as assessed by immunoblotting and immunohistochemistry. No changes were found in other regions of WAG/Rij rats including ventrobasal thalamic nuclei, somatosensory cortex, and hippocampus. Electron microscopy and in situ hybridization data suggested that mGlu4 receptors in the RTN are localized on excitatory cortical afferents. Systemic injection of the selective mGlu4 receptor positive allosteric modulator, N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen1a-carboxamide (PHCCC, 10mg/kg, s.c.), substantially enhanced the number of spike-and-wave discharges (SWDs) in WAG/Rij rats. Injection of PHCCC also enhanced absence-like seizures in PTZ-treated mice, whereas it was totally inactive in mGlu4 receptor knockout mice, which were intrinsically resistant to PTZ-induced seizures, as expected. This data supports the hypothesis that activation of mGlu4 receptors participates in the generation of absence seizures which can be exacerbated with the use of a positive allosteric modulator.
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Epilepsia Tipo Ausência/induzido quimicamente , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Animais , Benzopiranos/farmacologia , Western Blotting , Convulsivantes/farmacologia , Densitometria , Eletroencefalografia/efeitos dos fármacos , Epilepsia Tipo Ausência/fisiopatologia , Antagonistas GABAérgicos/farmacologia , Imuno-Histoquímica , Hibridização In Situ , Masculino , Microscopia Eletrônica , Pentilenotetrazol/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Fixação de TecidosAssuntos
Antibacterianos/farmacologia , Bacteroides/efeitos dos fármacos , Minociclina/análogos & derivados , Áustria , Bacteroides/patogenicidade , Infecções por Bacteroides/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Minociclina/farmacologia , TigeciclinaRESUMO
OBJECTIVE: To assess the efficacy of focal intense brief transcutaneous electric nerve stimulation in 2 groups of patients with neuropathic pain. DESIGN: Electric stimulation was delivered with a small stylus electrode pressed against the skin paravertebrally in the radiculopathy group and along the surgical incision in the postthoracotomy neuralgia group. A before-after treatment design was conducted with a verbal pain rating scale. SETTING: Outpatient multidisciplinary pain clinic at a Midwestern Veterans Affairs medical center. PARTICIPANTS: Fourteen consecutive patients with well-documented radiculopathy and 4 consecutive patients with postthoracotomy neuralgia. RESULTS: Statistically significant differences were found in both patient groups, with posttreatment scores reflecting less pain than pretreatment scores for every patient. CONCLUSIONS: Patients reported reduced pain ratings following this stimulation technique. Further study of this inexpensive, noninvasive, outpatient technique is needed.
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Manejo da Dor , Radiculopatia/complicações , Toracotomia/efeitos adversos , Estimulação Elétrica Nervosa Transcutânea , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Medição da Dor , Dor Pós-Operatória/terapia , Estatísticas não Paramétricas , Resultado do TratamentoRESUMO
OBJECTIVE: To assess the efficacy of multidisciplinary treatment in altering chronic pain patient locus of control beliefs. DESIGN: A before-and-after treatment design including demographics. PARTICIPANTS: Seventy-three chronic nonmalignant pain patients who completed study questionnaires both before and after treatment. SETTING: Comprehensive, outpatient, multidisciplinary pain management program at a large Midwestern university medical center. MAIN OUTCOME MEASURES: Pain Locus of Control Scale and Survey of Pain Attitudes Control subscale. RESULTS: Patients' perceptions of personal control over pain increased from pretreatment to posttreatment, and patients' perceptions of external control over pain, such as fate or powerful others. decreased from pretreatment to posttreatment. CONCLUSIONS: This study supports the efficacy of chronic pain management centers in altering patient beliefs about pain. The ability to increase patients' self-efficacy in their control over pain and to decrease external attributions are essential to successful pain management.
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Controle Interno-Externo , Clínicas de Dor , Dor/reabilitação , Adulto , Doença Crônica , Feminino , Humanos , Masculino , Dor/psicologia , Resultado do TratamentoRESUMO
OBJECTIVE: To examine the relationships between histories of sexual or physical abuse and current reports of dissociation, somatization, substance abuse, adaptive coping, and maladaptive coping strategies among chronic pelvic pain patients. METHODS: Using a structured interview, we assessed sexual and physical abuse and somatization. The Dissociative Experiences Scale was used to assess dissociation, and an abbreviated version of the COPE scale was employed to assess adaptive and maladaptive coping strategies as well as substance abuse. Participants included 46 women with chronic pelvic pain. RESULTS: Women with self-reported sexual or physical abuse histories were found to have significantly higher dissociation, somatization, and substance abuse scores than women without such a history. Significant positive correlations were found between reports of both dissociation and somatization with maladaptive coping strategies and among dissociation, somatization, and substance abuse. CONCLUSION: These results support the association between a positive abuse history and the high levels of dissociation, somatization, and substance abuse often noted in the chronic pelvic pain population. Findings suggest that such psychological variables are more likely to be associated with abuse than with the general medical condition. These psychological variables are conceptualized as maladaptive coping, which may be addressed as part of a biopsychosocial model of treatment for chronic pelvic pain patients.
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Adaptação Psicológica , Transtornos Dissociativos/etiologia , Dor Pélvica/complicações , Dor Pélvica/psicologia , Transtornos Somatoformes/etiologia , Transtornos Relacionados ao Uso de Substâncias/etiologia , Adolescente , Adulto , Maus-Tratos Infantis/psicologia , Doença Crônica , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
A case of hypereosinophilia syndrome in a cat is described.