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1.
PLoS Comput Biol ; 19(10): e1011554, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37831721

RESUMO

Sensory areas of cortex respond more strongly to infrequent stimuli when these violate previously established regularities, a phenomenon known as deviance detection (DD). Previous modeling work has mainly attempted to explain DD on the basis of synaptic plasticity. However, a large fraction of cortical neurons also exhibit firing rate adaptation, an underexplored potential mechanism. Here, we investigate DD in a spiking neuronal network model with two types of short-term plasticity, fast synaptic short-term depression (STD) and slower threshold adaptation (TA). We probe the model with an oddball stimulation paradigm and assess DD by evaluating the network responses. We find that TA is sufficient to elicit DD. It achieves this by habituating neurons near the stimulation site that respond earliest to the frequently presented standard stimulus (local fatigue), which diminishes the response and promotes the recovery (global fatigue) of the wider network. Further, we find a synergy effect between STD and TA, where they interact with each other to achieve greater DD than the sum of their individual effects. We show that this synergy is caused by the local fatigue added by STD, which inhibits the global response to the frequently presented stimulus, allowing greater recovery of TA-mediated global fatigue and making the network more responsive to the deviant stimulus. Finally, we show that the magnitude of DD strongly depends on the timescale of stimulation. We conclude that highly predictable information can be encoded in strong local fatigue, which allows greater global recovery and subsequent heightened sensitivity for DD.


Assuntos
Plasticidade Neuronal , Humanos , Fadiga , Modelos Neurológicos , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia
2.
Clin Oral Investig ; 28(2): 134, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38316644

RESUMO

OBJECTIVES: Oral and maxillofacial surgery (OMFS) has to compete with other specialties for the best candidates. With the upcoming change of generations (Z and Alpha) and the movement toward gender parity of dentistry, understanding changing preferences and misconceptions is essential. MATERIAL AND METHODS: An online survey was conducted by the German-Association-of-Oral-and-Maxillofacial-Surgery (DGMKG) across German dental schools. The survey collected demographic data, academic background, and career aspirations, with a focus on OMFS. The dental student survey results were compared to a survey given to OMFS Specialists. RESULTS: 637 dental students, mainly female (70%), from 30 German universities participated. 27% had defined career aspirations post-graduation, with self-employment and academia being popular choices. 67% were unsure. Specializations leaned towards restorative dentistry (41%), orthodontics (36%), and prosthodontics (31%). While 73% showed interest in surgical practices, 20% were attracted in specializing in OMFS. Of those averse to OMFS, 78% cited long training duration as the deterrent, 12% were put off by perceived unattractive working hours. Other reasons included negative undergraduate experiences, scarcity of part-time positions, and perceived inadequate earnings. CONCLUSION: Accurate data is crucial for career decisions. OMFS societies must proactively share accurate information and guide students. OMFS offers family-friendly hours, and while its training might be longer than dental specialties, it is on par with other surgical professions. CLINICAL RELEVANCE: Dental students consistently regard OMFS as commendable career path. To guarantee sustained OMFS expertise, it is imperative to nurture this interest through dedicated academic mentorship and innovative education, thereby solidifying their professional direction.


Assuntos
Ortodontia , Cirurgia Bucal , Humanos , Feminino , Masculino , Estudantes de Odontologia , Escolha da Profissão , Cirurgia Bucal/educação , Inquéritos e Questionários , Alemanha
3.
J Oral Maxillofac Surg ; 81(5): 641-647, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36682386

RESUMO

BACKGROUND: Skin and soft tissue infections (SSTIs) are common conditions with severe and potentially life-threatening outcomes. However, the use of antibiotics to treat these infections is controversial. PURPOSE: This study was to identify the microorganisms responsible for facial SSTIs, their antibiotic sensitivities, and the therapeutic outcomes of treatment. STUDY DESIGN, SETTING, AND SAMPLE: This was a retrospective, observational cohort study conducted at a single oral and maxillofacial plastic surgery department. The study sample included 103 patients with facial SSTIs (61 men, 42 women) with a mean age of 41.8 years (standard deviation ± 20.4). PREDICTOR/EXPOSURE/INDEPENDENT VARIABLES: The predictor variables included patient characteristics, antibiotic use before the clinic visit, and the infection's site and origin. MAIN OUTCOME VARIABLE(S): The primary outcome variable was the presence of antibiotic resistance in the bacterial strains isolated from the infections. METHODS: The data were collected by reviewing the results of microbiological swabs and patient records obtained from patients with facial SSTIs. Categorical variables were described using absolute and relative frequencies, and continuous variables were described using mean and standard deviation. The association between antibiotic resistance and the predictor variables was analyzed using Pearson's χ2 test and student's t test. RESULTS: The most common cause of SSTI was an infected epidermal cyst (60.1%). Of all the microorganisms identified, 80.6% were Gram-positive, and 55.8% showed antibiotic resistance against one or more of the evaluated antibiotics, including several backup antibiotics. There were no identified risk factors that significantly influenced the probability of resistance, and there were no adverse events observed. CONCLUSION: The results of this study suggest that surgery should be the primary approach for treating SSTIs, as antibiotic administration may not be effective due to the unknown susceptibility of the causative strains. Antibiotics should be reserved for severe cases and high-risk patients, and if deemed necessary for SSTI management, a broad-spectrum antibiotic should be administered to cover resistant organisms.


Assuntos
Antibacterianos , Infecções dos Tecidos Moles , Masculino , Humanos , Feminino , Adulto , Estudos de Coortes , Antibacterianos/uso terapêutico , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/microbiologia , Estudos Retrospectivos , Assistência Ambulatorial
4.
Food Microbiol ; 114: 104303, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37290879

RESUMO

Listeria monocytogenes can grow under stressful conditions and contaminate various food categories. Progresss in DNA sequencing-based identification methods, such as multi-locus sequence typing (MLST) now allow for more accurate characterization of pathogens. L. monocytogenes MLST genetic diversity is reflected by the different prevalence of the "clonal complexes" (CCs) in foods or infections. Better understanding of the growth potentials of L. monocytogenes is essential for quantitative risk assessment and efficient detection across CCs genetic diversity. Using optical density measurements taken with an automated spectrophotometer, we compared the maximal growth rate and lag phase of 39 strains from 13 different CCs and various food origins, in 3 broths mimicking stresful food conditions (8 °C, aw 0.95 and pH5) and in ISO Standard enrichment broths (Half Fraser and Fraser). This is important as growth could influence risk through pathogen multiplication in food. Besides, enrichment problems could lead to a lack of detection of some CCs. Despite small differences highlighting natural intraspecific variability, our results show that growth performances of L. monocytogenes strains under the conditions tested in selective and non-selective broth do not appear to be strongly correlated to CCs and cannot explain higher CC "virulence" or prevalence.


Assuntos
Listeria monocytogenes , Listeria monocytogenes/genética , Tipagem de Sequências Multilocus , Microbiologia de Alimentos , Análise de Sequência de DNA , Variação Genética
5.
Food Microbiol ; 106: 103757, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35690455

RESUMO

In response to the massive use of biocides for controlling Listeria monocytogenes (hereafter Lm) contaminations along the food chain, strains showing biocide tolerance emerged. Here, accessory genomic elements were associated with biocide tolerance through pangenome-wide associations performed on 197 Lm strains from different lineages, ecological, geographical and temporal origins. Mobile elements, including prophage-related loci, the Tn6188_qacH transposon and pLMST6_emrC plasmid, were widespread across lineage I and II food strains and associated with tolerance to benzalkonium-chloride (BC), a quaternary ammonium compound (QAC) widely used in food processing. The pLMST6_emrC was also associated with tolerance to another QAC, the didecyldimethylammonium-chloride, displaying a pleiotropic effect. While no associations were detected for chemically reactive biocides (alcohols and chlorines), genes encoding for cell-surface proteins were associated with BC or polymeric biguanide tolerance. The latter was restricted to lineage I strains from animal and the environment. In conclusion, different genetic markers, with polygenic nature or not, appear to have driven the Lm adaptation to biocide, especially in food strains but also from animal and the environment. These markers could aid to monitor and predict the spread of biocide tolerant Lm genotypes across different ecological niches, finally reducing the risk of such strains in food industrial settings.


Assuntos
Desinfetantes , Listeria monocytogenes , Animais , Compostos de Benzalcônio/farmacologia , Cloretos , Desinfetantes/farmacologia , Farmacorresistência Bacteriana/genética , Ecossistema , Genômica
6.
J Therm Biol ; 105: 103173, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35393042

RESUMO

The behavioral and physiological mechanisms of thermoregulation and the morphological traits of lizards result in a particular range of body temperatures, which influence performance and ultimately fitness. We studied the thermal biology and locomotor performance of the lizard Liolaemus wiegmannii from the coastal dunes in the southeastern Pampas of Argentina. During the austral summer, we examined the link between thermoregulation and optimal locomotor performance. Liolaemus wiegmannii faced a stressful environment due to high risk of overheating; despite this, the species was able to achieve field body temperatures (Mean Tb ± SD = 35.58 ± 2.86 °C) than expected by chance (i.e., the null model) and suitable for sustaining its physiological performance. Locomotion in this species was thermally-sensitive, with lizards showing high-performance bouts at a relatively wide range of body temperatures (30-38 °C). Lizards exhibited a mean maximum running speed of 1.30 m/s at 37.3 °C (i.e., optimal temperature for locomotion) which was within the set point range of preferred temperature (Tset = 35.4-37.5 °C). Therefore, we found a correspondence between thermal optimum and preferred temperature. Our findings suggest that L. wiegmannii, like other lizard species with a broad distribution, is capable of performing well across a wide range of temperatures despite the spatiotemporal thermal fluctuations of the environment.


Assuntos
Lagartos , Animais , Argentina , Biologia , Temperatura Corporal , Regulação da Temperatura Corporal , Lagartos/fisiologia , Temperatura
7.
J Craniofac Surg ; 32(8): 2798-2801, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34261973

RESUMO

ABSTRACT: Hyperplasia of the coronoid process is a rare condition, potentially leading to a mechanical mouth opening restriction. Diagnostic workup and treatment will be discussed based on 5 cases. This article presents 5 cases of true coronoid process hyperplasia. In addition, we reviewed accessible literature on the topic with special attention to pathophysiologic theories, surgical approach, and postoperative physiotherapy. The improvement in the maximal intercuspidal opening ranged from 4 and 31 mm. Greater maximal intercuspidal opening improvement was connected to compliant patients, while poor outcome occurred in the case of a patient that neither followed the recommendations for physical therapy nor showed up for his follow up appointments. The success of the therapy is defined by a long-lasting and stable improvement of the mouth opening compared to the preoperative situation. In the presented cases, the outcome was strongly dependent on the patients' postoperative compliance. Based on the cases described, we conclude that a good outcome is accomplishable for patients using the methods presented, as long as patients cooperate well after surgery.Diagnostic workup in patients with trismus should be thorough to correctly diagnose rare entities such as coronoid hyperplasia. If treated correctly this condition has a good outcome, as long as the compliance of the patient is adequate.


Assuntos
Anormalidades da Boca , Trismo , Humanos , Hiperplasia/patologia , Mandíbula/patologia , Modalidades de Fisioterapia , Trismo/etiologia
8.
Anim Cogn ; 23(6): 1119-1127, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32076920

RESUMO

In a constantly changing environment, it is advantageous for animals to encode a location (such as a food source) relying on more than one single cue. A certain position might, in fact, be signalled by the presence of information acquired through different sensory modalities which may be integrated into cohesive memories. Here, we aimed to investigate multi-sensory learning capabilities and multi-modal information integration in Lasius niger ants. Individual ants were placed in a Y-maze where odour information always led to a food reward; moreover, arm and wall colour were also predictive but only when co-occurring with odour in a specific combination. At test, the odour cue was made uninformative (it was present in both arms). Ants were still able to correctly locate the reward by integrating odour with the right colour and side combination. In a second experiment, we tested whether multi-modal cue integration can take place in a single trial. To this end, ants were exposed to a rewarded odour in a single-arm maze and could experience the Y-maze (with all available cues) only once. At test (which was identical to that of Experiment 1), ants showed a slight preference for the correct colour-side combination, although not significantly different from chance level. Our results showed the capability of black garden ants to code apparently redundant contextual information and to create and rely on conditional relationships between the information available. We argue that future studies should deepen the inquiry on the timing and progression of multi-modal cue learning.


Assuntos
Formigas , Animais , Cor , Sinais (Psicologia) , Aprendizagem , Memória
9.
Neuroradiology ; 62(3): 341-346, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31838562

RESUMO

PURPOSE: To develop and evaluate a technical approach for CT-guided periradicular infiltration using quantitative needle access and guidance parameters extracted from CT scout images. METHODS: Five 3D-printed phantoms of the abdomen mimicking different patients were used to develop a technical approach for scout-guided periradicular infiltration. The needle access point, puncture depth, and needle angulation were calculated using measurements extracted from anterior-posterior and lateral CT scout images. Fifty needle placements were performed with the technique thus developed. Dose exposure and number of image acquisitions were compared with ten procedures performed using a conventional free-hand technique. Data were analyzed with the Mann-Whitney U test. RESULTS: Parameters derived solely from scout images provided adequate guidance for successful and reliable needle placement. Needle guidance was performed with the same equipment as the standard periradicular infiltration. Two scout images and 3.5 ± 2.3 (mean ± SD) single-shot images for needle positioning were acquired. Mean DLP ± SD was 3.8 ± 2.5 mGy cm. The number of single-shot acquisitions was reduced by 68% and the overall dose was reduced by 84% in comparison with the conventional free-hand technique (p < 0.0001). CONCLUSION: Scout-guided needle placement for periradicular infiltration is feasible and reduces radiation exposure significantly.


Assuntos
Radiculopatia/tratamento farmacológico , Radiografia Intervencionista/métodos , Tomografia Computadorizada por Raios X/métodos , Abdome , Humanos , Injeções Espinhais , Agulhas , Imagens de Fantasmas , Impressão Tridimensional , Punções , Doses de Radiação , Radiculopatia/diagnóstico por imagem
10.
J Appl Clin Med Phys ; 21(9): 201-208, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32721106

RESUMO

PURPOSE: To develop a customized method to produce uniform phantoms for task-based assessment of CT image quality. METHODS: Contrasts between polymethyl methacrylate (PMMA) and fructose solutions of different concentrations (240, 250, 260, 280, 290, 300, 310, 320, 330, and 340 mg/mL) were calculated. A phantom was produced by laser cutting PMMA slabs to the shape of a patient's neck. An opening of 10 mm diameter was cut into the left parapharyngeal space. An angioplasty balloon was inserted and filled with the fructose solutions to simulate low-contrast lesions. The phantom was scanned with six tube currents. Images were reconstructed with filtered back projection (FBP) and adaptive iterative dose reduction 3D (AIDR 3D). Calculated and measured contrasts were compared. The phantom was evaluated in a detectability experiment using images with 4 and 20 HU lesion contrast. RESULTS: Low-contrast lesions of 4, 9, 11, 13, 18, 20, 24, 30, 35, and 37 HU contrast were simulated. Calculated and measured contrasts correlated excellently (r = 0.998; 95% confidence interval: 0.991 to 1). The mean ± SD difference was 0.41 ± 2.32 HU (P < 0.0001). Detection accuracy and reader confidence were 62.9 ± 18.2% and 1.58 ± 0.68 for 4 HU lesion contrast and 99.6 ± 1.3% and 4.27 ± 0.92 for 20 HU lesion contrast (P < 0.0001), confirming that the method produced lesions at the threshold of detectability. CONCLUSION: A cost-effective and flexible approach was developed to create uniform phantoms with low-contrast signals. The method should facilitate access to customized phantoms for task-based image quality assessment.


Assuntos
Algoritmos , Tomografia Computadorizada por Raios X , Humanos , Imagens de Fantasmas , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador
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