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1.
Int J Biol Macromol ; 258(Pt 2): 128982, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38154718

RESUMO

Cellulose nanocrystals (CNCs) are biodegradable particles that have emerged as promising stabilizers for Pickering emulsions. This study investigated the effectiveness of CNCs in forming the Pickering emulsion from hazelnut shells (HS), an agricultural waste. Following the alkaline and bleaching treatments applied to HS, CNCs were obtained from treated hazelnut shell with acid hydrolysis. The physicochemical characteristics of CNCs were investigated using dynamic light scattering, XRD, FTIR, SEM, and TEM. A high crystalline (69.6 %) CNCs with a spherical shape were obtained. Contact angle and interfacial tension tests were conducted and showed that CNCs had amphiphilic nature. Pickering emulsions were investigated for their size, zeta potential, and stability under varying CNC concentrations. The results showed that when CNCs concentration increased from 0.5 to 2.0 wt%, droplet diameter decreased approximately 1.8 times and zeta potential increased. Creaming was not observed during 28 days of storage in a concentration of 2.0 wt% CNCs. The CNC stabilized emulsions exhibited high stability within a range of pH, temperatures, and salt concentrations. This study demonstrated that CNCs extracted from HS as environmentally friendly and cost-effective materials, could serve as a new stabilizer for Pickering emulsions especially for high temperature and low pH sensitive products such as mayonnaise.


Assuntos
Corylus , Nanopartículas , Celulose/química , Emulsões/química , Nanopartículas/química , Alimentos
2.
Antibiotics (Basel) ; 12(5)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37237746

RESUMO

BACKGROUND: Antimicrobial resistance (AMR) is one of the biggest threats to public health. The food chain has been recognised as a vehicle for transmitting AMR bacteria. However, information about resistant strains isolated from African traditional fermented foods remains limited. Nono is a traditional, naturally fermented milk product consumed by many pastoral communities across West Africa. The main aim of this study was to investigate and determine the AMR patterns of lactic acid bacteria (LAB) involved in the traditional fermentation of milk for Nono production, and the presence of transferable AMR determinants. METHODS: One hundred (100) LAB isolates from Nono identified in a previous study as Limosilactobacillus fermentum, Lactobacillus delbrueckii, Streptococcus thermophilus, Streptococcus infantarius, Lentilactobacillus senioris, Leuconostoc pseudomesenteriodes, and Enterococcus thailandicus were investigated. The minimum inhibitory concentration (MIC) was determined for 18 antimicrobials using the micro-broth dilution method. In addition, LAB isolates were screened for 28 antimicrobial resistance genes using PCR. The ability of LAB isolates to transfer tetracycline and streptomycin resistance genes to Enterococcus faecalis was also investigated. RESULTS: The experiments revealed variable antimicrobial susceptibility according to the LAB isolate and the antimicrobial tested. The tetracycline resistance genes tet(S) and tet(M) were detected in isolates Ent. thailandicus 52 and S. infantarius 10. Additionally, aad(E) encoding resistance to streptomycin was detected in Ent. thailandicus 52. The conjugation experiments suggested that the tet(S) and aad(E) genes were transferable in vitro from isolate Ent. thailandicus 52 to Ent. faecalis JH2-2. SIGNIFICANCE AND IMPACT: Traditional fermented foods play a significant role in the diet of millions of people in Africa, yet their contribution to the burden of AMR is largely unknown. This study highlights that LAB involved in traditionally fermented foods could be potential reservoirs of AMR. It also underscores the relevant safety issues of Ent. thailandicus 52 and S. infantarius 10 for use as starter cultures as they carry transferable AMR genes. Starter cultures are an essential aspect of improving the safety and quality attributes of African fermented foods. However, AMR monitoring is an important safety aspect in the selection of starter cultures for improving traditional fermentation technologies.

3.
Int J Biol Macromol ; 242(Pt 1): 124704, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37146853

RESUMO

This study aimed to investigate the potential application of cellulose nanocrystals (CNCs) extracted from an agricultural waste for encapsulation of oregano essential oil (OEO) and subsequently their use for coating to improve the shelf life of pears as a model. By hydrolyzing hazelnut shell cellulose under the optimum conditions, high crystalline CNCs with a zeta potential of -67.8 ± 4.4 mV and a diameter of 157 ± 10 nm were produced. Different concentrations of OEO (10-50 % w/w) were incorporated into CNCs and characterized using FTIR, XRD, SEM and TEM. OEO containing 50 % CNC with the highest EE and LC was selected for coating. Pears were coated with gluten containing 0.5, 1.5 and 2 % encapsulated OEO (EOEO) and pure OEO and stored for 28 days. Physicochemical, microbial and sensory properties of the pears were examined. Microbial analysis showed that EOEO2% was more effective in controlling microbial growth than controls and pure OEO, and a 1.09 Log reduction in bacterial count was recorded on day 28 of storage when compared to control. It was concluded that CNCs produced from an agricultural waste and loaded on an essential oil could be used to extend the shelf life of pear and potentially other fruits.


Assuntos
Corylus , Nanopartículas , Óleos Voláteis , Origanum , Pyrus , Celulose/química , Óleos Voláteis/química , Origanum/química , Frutas , Nanopartículas/química
4.
Front Psychol ; 13: 892416, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936250

RESUMO

Attention and memory for everyday experiences vary over time, wherein some moments are better attended and subsequently better remembered than others. These effects have been demonstrated in naturalistic viewing tasks with complex and relatively uncontrolled stimuli, as well as in more controlled laboratory tasks with simpler stimuli. For example, in the attentional boost effect (ABE), participants perform two tasks at once: memorizing a series of briefly presented stimuli (e.g., pictures of outdoor scenes) for a later memory test, and responding to other concurrently presented cues that meet pre-defined criteria (e.g., participants press a button for a blue target square and do nothing for a red distractor square). However, rather than increasing dual-task interference, attending to a target cue boosts, rather than impairs, subsequent memory for concurrently presented information. In this review we describe current data on the extent and limitations of the attentional boost effect and whether it may be related to activity in the locus coeruleus neuromodulatory system. We suggest that insight into the mechanisms that produce the attentional boost effect may be found in recent advances in the locus coeruleus literature and from understanding of how the neurocognitive system handles stability and change in everyday events. We consequently propose updates to an early account of the attentional boost effect, the dual-task interaction model, to better ground it in what is currently known about event cognition and the role that the LC plays in regulating brain states.

5.
J Vet Sci ; 23(4): e52, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35920120

RESUMO

This paper reports a presumptive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a cat. A cat with respiratory disease living with three individuals with coronavirus disease 2019 showed bilateral ground-glass opacities in the lung on X-ray and computed tomography. The clinical swabs were negative for SARS-CoV-2 RNA, but the serum was positive for SARS-CoV-2 antibodies. Interstitial pneumonia and prominent type 2 pneumocyte hyperplasia were noted on histopathology. Respiratory tissues were negative for SARS-CoV-2 RNA or antigen, but the cat was positive for feline parvovirus DNA. In conclusion, the respiratory disease and associated pathology in this cat could have been due to exposure to SARS-CoV-2.


Assuntos
COVID-19 , Doenças do Gato , Animais , Anticorpos Antivirais , COVID-19/veterinária , Doenças do Gato/diagnóstico por imagem , Gatos , RNA Viral , SARS-CoV-2 , Tomografia Computadorizada por Raios X/veterinária
6.
Front Psychol ; 13: 891682, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35769754

RESUMO

Though dividing one's attention between two input streams typically impairs performance, detecting a behaviorally relevant stimulus can sometimes enhance the encoding of unrelated information presented at the same time. Previous research has shown that selection of this kind boosts visual cortical activity and memory for concurrent items. An important unanswered question is whether such effects are reflected in processing quality and functional connectivity in visual regions and in the hippocampus. In this fMRI study, participants were asked to memorize a stream of naturalistic images and press a button only when they heard a predefined target tone (400 or 1,200 Hz, counterbalanced). Images could be presented with a target tone, with a distractor tone, or without a tone. Auditory target detection increased activity throughout the ventral visual cortex but lowered it in the hippocampus. Enhancements in functional connectivity between the ventral visual cortex and the hippocampus were also observed following auditory targets. Multi-voxel pattern classification of image category was more accurate on target tone trials than on distractor and no tone trials in the fusiform gyrus and parahippocampal gyrus. This effect was stronger in visual cortical clusters whose activity was more correlated with the hippocampus on target tone than on distractor tone trials. In agreement with accounts suggesting that subcortical noradrenergic influences play a role in the attentional boost effect, auditory target detection also caused an increase in locus coeruleus activity and phasic pupil responses. These findings outline a network of cortical and subcortical regions that are involved in the selection and processing of information presented at behaviorally relevant moments.

7.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-938404

RESUMO

This paper reports a presumptive severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) infection in a cat. A cat with respiratory disease living with three individuals with coronavirus disease 2019 showed bilateral ground-glass opacities in the lung on X-ray and computed tomography. The clinical swabs were negative for SARS-CoV-2 RNA, but the serum was positive for SARS-CoV-2 antibodies. Interstitial pneumonia and prominent type 2 pneumocyte hyperplasia were noted on histopathology. Respiratory tissues were negative for SARS-CoV-2 RNA or antigen, but the cat was positive for feline parvovirus DNA. In conclusion, the respiratory disease and associated pathology in this cat could have been due to exposure to SARS-CoV-2.

8.
Microorganisms ; 9(8)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34442679

RESUMO

A selection of 36 commercial probiotic fermented dairy products from UK and Europe markets were evaluated for the numbers, types, and viability of Lactobacillus strains against the stated information on their packages. A comparative study was carried out on selectivity of MRS-Clindamycin, MRS-Sorbitol, and MRS-IM Maltose, to select the right medium for enumeration of probiotic Lactobacillus. Based on selectivity of medium for recovery of the targeted lactobacilli, and also simplicity of preparation, MRS-Clindamycin was chosen as the best medium for enumeration of probiotic Lactobacillus in fermented milks. The results of enumeration of lactobacilli showed that 22 out of a total 36 tested products contained more than 106 colony-forming units/g at the end of their shelf life, which comply with the recommended minimum therapeutic level for probiotics. Rep-PCR using primer GTG-5 was applied for initial discrimination of isolated strains, and isolates, which presented different band profile, were placed in different groups. The isolated Lactobacillus spp. were identified mainly as Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus paracasei by analysis of partial sequences of the 16S ribosomal RNA and rpoA genes.

9.
Neuroimage ; 236: 118047, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33905860

RESUMO

The locus coeruleus (LC) plays a central role in regulating human cognition, arousal, and autonomic states. Efforts to characterize the LC's function in humans using functional magnetic resonance imaging have been hampered by its small size and location near a large source of noise, the fourth ventricle. We tested whether the ability to characterize LC function is improved by employing neuromelanin-T1 weighted images (nmT1) for LC localization and multi-echo functional magnetic resonance imaging (ME-fMRI) for estimating intrinsic functional connectivity (iFC). Analyses indicated that, relative to a probabilistic atlas, utilizing nmT1 images to individually localize the LC increases the specificity of seed time series and clusters in the iFC maps. When combined with independent components analysis (ME-ICA), ME-fMRI data provided significant improvements in the temporal signal to noise ratio and DVARS relative to denoised single echo data (1E-fMRI). The effects of acquiring nmT1 images and ME-fMRI data did not appear to only reflect increases in power: iFC maps for each approach overlapped only moderately. This is consistent with findings that ME-fMRI offers substantial advantages over 1E-fMRI acquisition and denoising. It also suggests that individually identifying LC with nmT1 scans is likely to reduce the influence of other nearby brainstem regions on estimates of LC function.


Assuntos
Conectoma/métodos , Locus Cerúleo/diagnóstico por imagem , Locus Cerúleo/fisiologia , Imageamento por Ressonância Magnética/métodos , Melaninas/metabolismo , Adulto , Imagem Ecoplanar/métodos , Tecnologia de Rastreamento Ocular , Feminino , Humanos , Locus Cerúleo/metabolismo , Masculino , Adulto Jovem
10.
Braz J Microbiol ; 52(2): 869-881, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33694058

RESUMO

The aim of this research was to identify the key lactic acid bacteria associated with the fermentation of dairy traditional fermented products for developing starter cultures for controlled fermentation. A total of 100 lactic acid bacteria (LAB) were isolated from dairy traditional fermented products. Samples were obtained from eight producers in the South East of Nigeria. Isolates were identified by phenotypic and genotypic techniques including rep-PCR genotyping and sequencing of the 16S rRNA, pheS and rpoA genes. Isolates were characterised for antimicrobial activity against foodborne pathogens, exopolysaccharide (EPS) production and survival at low pH and in the presence of bile salts. All isolates clustered into 11 distinct rep-PCR groups and were identified as Lactobacillus fermentum (40%), Lactobacillus delbrueckii (23%), Streptococcus thermophilus (22%), Streptococcus infantarius (10%), Lactobacillus senioris (2%), Leuconostoc pseudomesenteriodes (2%) and Enterococcus thailandicus (1%). Lactobacillus fermentum showed a broad spectrum antimicrobial activity and survival at low pH, while Lactobacillus delbrueckii was able to tolerate low pH and produce EPS. All isolates survived in vitro exposure to 1% (w/v) bile salts over a 3-h period. L. fermentum, L. delbrueckii and S. thermophilus could be used to simulate the fermentation of dairy traditional fermented products.


Assuntos
Produtos Fermentados do Leite/microbiologia , Lactobacillales/isolamento & purificação , Lactobacillales/fisiologia , Antibiose , Ácidos e Sais Biliares/farmacologia , Fermentação , Genes Bacterianos/genética , Genótipo , Concentração de Íons de Hidrogênio , Lactobacillales/classificação , Lactobacillales/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Nigéria , Polissacarídeos Bacterianos/metabolismo , RNA Ribossômico 16S/genética
11.
Anticancer Agents Med Chem ; 21(5): 630-639, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32698739

RESUMO

BACKGROUND AND PURPOSE: Cancer is the primary cause of death in the world. Vanadium (IV) is a metal ion complex which has been proposed as a suitable candidate for cancer treatment. In this study, the interaction of the oxido-vanadium (IV) complex [VOL(bipy)] with salmon sperm DNA and Bovine Serum Albumin (BSA) was investigated through experimental and computational approaches. With the results of this experimental study, the mechanism and parameters related to the interaction of [VOL(bipy)] with DNA and BSA were determined. MATERIALS AND METHODS: The kinetic interaction of DNA and BSA with [VOL(bipy)] was determined using absorption titration and fluorescence quenching, respectively. Moreover, the possible interactions were calculated by molecular docking prediction using the available software. RESULTS: The binding constant (Kb) of the complex-DNA interaction was calculated to be 2.34×104 M-1, indicating a relatively strong interaction between the complex and DNA. It was found that the V(IV) complex interacted with DNA through the groove binding mode followed by partial intercalation into the DNA helix. The Kb values obtained for [VOL(bipy)]-BSA interaction were in the range of 1.07×103-5.82×104 M-1. The V(IV) complex was found to prefer the domain I binding pocket of BSA with the ΔGb value of -7.52 kcal/mol. CONCLUSION: Both experimental and computational analyses confirmed the interaction of the vanadium complex with DNA and BSA. The moderate affinity of [VOL(bipy)] for BSA indicates that this protein is a good candidate for transferring the complex.


Assuntos
Antineoplásicos/química , Complexos de Coordenação/química , DNA de Neoplasias/química , Bases de Schiff/química , Soroalbumina Bovina/química , Vanadatos/química , Animais , Antineoplásicos/síntese química , Bovinos , Complexos de Coordenação/síntese química , Humanos , Cinética , Estrutura Molecular
12.
Osteoarthritis Cartilage ; 28(3): 324-333, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31904489

RESUMO

OBJECTIVE: Surgical knee joint distraction (KJD) leads to clinical improvement in knee osteoarthritis (OA) and also apparent cartilage regeneration by magnetic resonance imaging. We investigated if alteration of the joint's mechanical environment during the 6 week period of KJD was associated with a molecular response in synovial fluid, and if any change was associated with clinical response. METHOD: 20 individuals undergoing KJD for symptomatic radiographic knee OA had SF sampled at baseline, midpoint and endpoint of distraction (6 weeks). SF supernatants were measured by immunoassay for 10 predefined mechanosensitive molecules identified in our previous pre-clinical studies. The composite Knee injury and OA Outcome Score-4 (KOOS4) was collected at baseline, 3, 6 and 12 months. RESULTS: 13/20 (65%) were male with mean age 54°±°5yrs. All had Kellgren-Lawrence grade ≥2 knee OA. 6/10 analytes showed statistically significant change in SF over the 6 weeks distraction (activin A; TGFß-1; MCP-1; IL-6; FGF-2; LTBP2), P < 0.05. Of these, all but activin A increased. Those achieving the minimum clinically important difference of 10 points for KOOS4 over 6 months showed greater increases in FGF-2 and TGFß-1 than non-responders. An increase in IL-8 during the 6 weeks of KJD was associated with significantly greater improvement in KOOS4 over 12 months. CONCLUSION: Detectable, significant molecular changes are observed in SF following KJD, that are remarkably consistent between individuals. Preliminary findings appear to suggest that increases in some molecules are associated with clinically meaningful responses. Joint distraction may provide a potential opportunity in the future to define regenerative biomarker(s) and identify pathways that drive intrinsic cartilage repair.


Assuntos
Fixadores Externos , Procedimentos Ortopédicos/métodos , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/cirurgia , Líquido Sinovial/metabolismo , Ativinas/metabolismo , Moléculas de Adesão Celular/metabolismo , Quimiocina CCL2/metabolismo , Feminino , Fator 2 de Crescimento de Fibroblastos/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Proteínas de Ligação a TGF-beta Latente/metabolismo , Masculino , Metaloproteinase 3 da Matriz/metabolismo , Pessoa de Meia-Idade , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Resultado do Tratamento
13.
Int J Food Microbiol ; 311: 108356, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31670141

RESUMO

Different samples of three products including Bikalga and Soumbala from Burkina Faso (West Africa) and Ntoba Mbodi from Congo-Brazzaville (Central Africa) were evaluated. The bacteria (400) were phenotyped and genotypically characterized by Rep-PCR, PFGE, 16S rRNA and rpoB gene sequencing and spa typing. Their PFGE profiles were compared with those of 12,000 isolates in the Center for Disease Control (CDC, USA) database. They were screened for the production of enterotoxins, susceptibility to 19 antimicrobials, presence of 12 staphylococcal toxin and 38 AMR genes and the ability to transfer erythromycin and tetracycline resistance genes to Enterococcus faecalis JH2-2. Fifteen coagulase negative (CoNS) and positive (CoPS) species characterized by 25 Rep-PCR/PFGE clusters were identified: Staphylococcus arlettae, S. aureus, S. cohnii, S. epidermidis, S. gallinarum, S. haemolyticus, S. hominis, S. pasteuri, S. condimenti, S. piscifermentans, S. saprophyticus, S. sciuri, S. simulans, S. warneri and Macrococcus caseolyticus. Five species were specific to Soumbala, four to Bikalga and four to Ntoba Mbodi. Two clusters of S. gallinarum and three of S. sciuri were particular to Burkina Faso. The S. aureus isolates exhibited a spa type t355 and their PFGE profiles did not match any in the CDC database. Bacteria from the same cluster displayed similar AMR and toxin phenotypes and genotypes, whereas clusters peculiar to a product or a location generated distinct profiles. The toxin genes screened were not detected and the bacteria did not produce the staphylococcal enterotoxins A, B, C and D. AMR genes including blazA, cat501, dfr(A), dfr(G), mecA, mecA1, msr(A) and tet(K) were identified in CoNS and CoPS. Conjugation experiments produced JH2-2 isolates that acquired resistance to erythromycin and tetracycline, but no gene transfer was revealed by PCR. The investigation of the heterogeneity of Staphylococcus species from alkaline fermented foods, their relationship with clinical and environmental isolates and their safety in relation to antimicrobial resistance (AMR) and toxin production is anticipated to contribute to determining the importance of staphylococci in alkaline fermented foods, especially in relation to the safety of the consumers.


Assuntos
Enterotoxinas/genética , Alimentos Fermentados/microbiologia , Staphylococcus , Antibacterianos/farmacologia , Burkina Faso , Coagulase/genética , Congo , RNA Polimerases Dirigidas por DNA/genética , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Genótipo , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Tetraciclina/farmacologia
14.
Afr Health Sci ; 19(1): 1665-1670, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31148996

RESUMO

BACKGROUND: Despite the increasing incidence of Prostate cancer, there has not been any focused screening policy or strategy in sub-Saharan Africa including Nigeria. OBJECTIVES: To assess the level of awareness and uptake of PSA screening test and their determinants in a Nigerian community. METHODS: A cross-sectional population survey of men with no prior history of prostate cancer was carried out. Logistic regression analysis was used to determine the effect of identified variables in predicting awareness and uptake of prostate cancer screening. RESULTS: Mean age was 51.5±9.8 years; a few men (31, 16.9%) had ever heard of the screening test and most got the information from health centers. A low proportion (8, 4.4%) had taken the screening test. Men with incomes above poverty line (OR = 11.7 2.8-50.1, p = .001) or those with health insurance (OR = 2.7 1.2-6.5, p = .023) were significantly more likely to be aware of the test. Only the men with higher incomes (OR = 25.6 5.8-114.2, p = .0001) were significantly more likely to have taken the test. CONCLUSION: Higher incomes and health insurance status impact screening awareness but only income status determines if men subsequently proceed to take the PSA screening test.


Assuntos
Detecção Precoce de Câncer/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/prevenção & controle , Adulto , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Nigéria/epidemiologia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/etnologia , Inquéritos e Questionários
15.
Mem Cognit ; 47(1): 1-16, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30097907

RESUMO

Memory for the items one has recently encountered is sometimes enhanced in divided attention tasks: Attending to behaviorally relevant items, such as a target in a detection task, boosts memory for unrelated background items (e.g., scenes or words). However, a central feature of episodic memory is memory for the spatiotemporal relationship between items and other elements of an event (relational memory), not just the item itself. Three experiments examined whether attending to a behaviorally relevant target-item boosts memory for the relationship between that item, its features, and a background scene. Participants memorized briefly presented scenes. At the same time, they pressed a button if a second unrelated item (a figure or face) was a particular target color (Experiments 1 and 2) or target gender (Experiment 3) rather than a distractor color or gender. Target and distractor items also varied in task-irrelevant features (shape, location, or facial identity). If attending to behaviorally relevant events influences relational memory, then participants should be better able to report both target-defining and irrelevant features of items that appeared with target-paired scenes rather than distractor-paired scenes. This was the case in all experiments: memory was enhanced for the target-paired scenes as well as the association between a scene and features of the paired target-item. Attending to behaviorally relevant moments therefore has broader effects on memory encoding than previously thought. In addition to boosting memory for unrelated background items, attending to targets facilitates relational memory in these tasks.


Assuntos
Associação , Atenção/fisiologia , Função Executiva/fisiologia , Memória Episódica , Reconhecimento Visual de Modelos/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Reconhecimento Facial/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
17.
ISRN Microbiol ; 2013: 731430, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24195005

RESUMO

Some rare strains of Clostridium butyricum carry the gene encoding the botulinal type E neurotoxin and must be considered as possible hazards in certain types of food. The limiting growth conditions for C. butyricum were determined in peptone yeast glucose starch (PYGS) broth incubated anaerobically at 30°C for up to 42 days. The minimum pH values permitting growth depended on the acidulant and strain. Organic acids were more effective at inhibiting growth than HCl as expected. The lowest pH values at which growth of toxigenic and nontoxigenic strains of C. butyricum was observed in broth acidified with HCl were 4.1 and 4.2, respectively. In organic acids, however, the minimum pH varied between 4.4 and 5.1 depending on acid type and concentration. The minimum water activity for growth of toxigenic strains of C. butyricum was 0.96. The minimum growth temperatures of the toxigenic strains of C. butyricum (ca 10-11°C) were somewhat higher than for non-toxigenic ones (8°C). It was concluded that control of toxigenic C. butyricum in the food industry needs to allow for the greater pH tolerance of this species compared with proteolytic C. botulinum.

18.
Lett Appl Microbiol ; 57(2): 115-21, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23574042

RESUMO

UNLABELLED: Of the twenty-three morphotypes of yeasts isolated from soil capable of utilizing pectin as sole carbon source at 6°C, two yeast isolates, one psychrotolerant (PT1) and one psychrophilic (SPY11), were selected according to their ability to secrete pectinolytic enzymes under some oenological conditions (temperature 6 and 12°C and pH 3.5) and ability or inability to grow above 20°C, respectively. As compared to their optimal activity, the three pectinolytic enzymes viz., pectin methyl esterase (PME), endopolygalacturonase (endo-PG) and exopolygalacturonase (exo-PG) isolated and assayed at pH 3.5 from PT1 were found to retain 39, 60 and 60% activity at 12°C and 40, 79 and 74% activity at 28°C, respectively. Likewise, the enzymes PME and endo-PG at pH 3.5 from SPY11 displayed 46 and 86% activity at 12°C and 50 and 60% activity at 28°C, respectively. All these enzymes showed 20-90% of residual activity at pH 3.5 and 6°C. The yeast isolates PT1 and SPY11 were identified as Rhodotorula mucilaginosa and Cystofilobasidium capitatum, respectively, on the basis of morphological, physiological and molecular characteristics. This study presents the first report on pectinolytic activities under major oenological conditions from psychrotolerant isolate R. mucilaginosa PT1 and psychrophilic isolate C. capitatum SPY11. SIGNIFICANCE AND IMPACT OF THE STUDY: The cold-active pectinolytic enzymes (PME, endo-PG and exo-PG) from the newly isolated and identified psychrophilic yeast Cystofilobasidium capitatum SPY11 and psychrotolerant yeast Rhodotorula mucilaginosa PT1that exhibited 50-80% of their optimum activity under some major oenological conditions pH (3.5) and temperatures (6 and 12°C) could be applied to wine production and juice clarification at low temperature. The psychrotrophic yeasts themselves could be applied to cold process for the production of enzymes thus saving cost of energy and protecting process from contamination.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Glicosídeo Hidrolases/metabolismo , Pectinas/metabolismo , Poligalacturonase/metabolismo , Vinho , Leveduras/enzimologia , Basidiomycota/enzimologia , Basidiomycota/isolamento & purificação , Temperatura Baixa , Concentração de Íons de Hidrogênio , Poligalacturonase/química , Poligalacturonase/isolamento & purificação , Rhodotorula/enzimologia , Rhodotorula/isolamento & purificação , Temperatura , Leveduras/isolamento & purificação
19.
Neurology Asia ; : 259-261, 2011.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-628801

RESUMO

Ramsay Hunt syndrome, also known as herpes zoster oticus is usually caused by reactivation of preexisting varicella zoster virus in the geniculate ganglion. Here we report a case of herpes zoster oticus masquerading as lateral pontomedullary syndrome occurring during the pre-eruptive phase of chicken pox. The case is being reported for its rare and unusual clinical presentation.

20.
Int J Food Microbiol ; 142(1-2): 202-6, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20633941

RESUMO

Clostridia such as Clostridium tyrobutyricum, C. pasteurianum and C. butyricum may cause spoilage problems in certain types of food, but they are not normally regarded as dangerous. However some strains of C. butyricum have acquired the type E botulinum neurotoxin gene and have caused both infant and classical botulism in Italy (1986), China (1994) and India (1996). This study was carried out to examine a range of samples from fresh vegetables to food and environmental samples in the UK and test their ability to produce type E botulinal neurotoxin (BoNT) by probing for the presence of the toxin gene. Samples were enriched in modified Bhat and Barker (MBB) broth which is a minimal medium with lactate and acetate as a source of carbon and energy. In addition selective antibiotics are present in the medium to favour the growth of C. butyricum. This was followed by plating out onto iron sulphite agar (ISA) for isolation of C. butyricum from food and environmental samples. A total of 978 samples were tested and 302 (31%) yielded presumptive C. butyricum isolates. The highest percentage of positives came from soil, potato skins, Swede skin, yoghurt and cream. No positive isolates were obtained from pate, garlic or spring greens. A sub-sample of isolates was examined for the presence of gene encoding the type E botulinum neurotoxin using PCR. Only one of the many existing PCR methods was successful and therefore used for screening C. butyricum isolates for the presence of the type E toxin gene. None of the 93 tested isolates were found to be toxigenic (type E botulinal neurotoxin).


Assuntos
Toxinas Botulínicas/metabolismo , Clostridium butyricum/isolamento & purificação , Clostridium butyricum/metabolismo , Microbiologia Ambiental , Microbiologia de Alimentos , Clostridium butyricum/genética , Dados de Sequência Molecular , Reino Unido
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