Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Plants (Basel) ; 13(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38931113

RESUMO

In this study, an advanced method for apricot tree disease detection is proposed that integrates deep learning technologies with various data augmentation strategies to significantly enhance the accuracy and efficiency of disease detection. A comprehensive framework based on the adaptive sampling latent variable network (ASLVN) and the spatial state attention mechanism was developed with the aim of enhancing the model's capability to capture characteristics of apricot tree diseases while ensuring its applicability on edge devices through model lightweighting techniques. Experimental results demonstrated significant improvements in precision, recall, accuracy, and mean average precision (mAP). Specifically, precision was 0.92, recall was 0.89, accuracy was 0.90, and mAP was 0.91, surpassing traditional models such as YOLOv5, YOLOv8, RetinaNet, EfficientDet, and DEtection TRansformer (DETR). Furthermore, through ablation studies, the critical roles of ASLVN and the spatial state attention mechanism in enhancing detection performance were validated. These experiments not only showcased the contributions of each component for improving model performance but also highlighted the method's capability to address the challenges of apricot tree disease detection in complex environments. Eight types of apricot tree diseases were detected, including Powdery Mildew and Brown Rot, representing a technological breakthrough. The findings provide robust technical support for disease management in actual agricultural production and offer broad application prospects.

2.
J Food Prot ; 87(7): 100292, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38718984

RESUMO

Currently, there is limited knowledge on the survival of bacteria on surfaces during postharvest handling of dry products such as onions. Extended survival of microorganisms, coupled with a lack of established and regular, validated cleaning or sanitation methods could enable cross-contamination of these products. The aim of the study was to evaluate the survival of a potential surrogate, Enterococcus faecium, and Salmonella enterica on typical onion handling surfaces, polyurethane (PU), and stainless steel (SS), under low relative humidity. The influence of onion extract on the survival of E. faecium and Salmonella on PU and SS was also investigated. Rifampin-resistant E. faecium NRRL B-2354 and a five-strain cocktail of Salmonella suspended in 0.1% peptone or onion extract were separately inoculated onto PU and SS coupons (2 × 2 cm), at high, moderate, or low (7, 5, or 3 log CFU/cm2) levels. The inoculated surfaces were stored at ∼34% relative humidity and 21°C for up to 84 days. Triplicate samples were enumerated at regular intervals in replicate trials. Samples were enriched when populations fell below the limit of detection by plating (0.48 log CFU/cm2). Scanning electron microscopy was used to observe the cell distribution on the coupons. Reductions of E. faecium of less than ∼2 log were observed on PU and SS over 12 weeks at all inoculum levels and with both inoculum carriers. In 0.1% peptone, Salmonella populations declined by 2 to 3 log over 12 weeks at the high and moderate inoculum levels; at the low inoculum level, Salmonella could not be recovered by enrichment at 84 days. Survival of E. faecium and Salmonella was significantly (P < 0.05) enhanced over 84 days of storage when suspended in onion extract, where cells were covered by a layer of onion extract. E. faecium might have utility as a conservative surrogate for Salmonella when evaluating microbial survival on dry food-contact surfaces.


Assuntos
Contagem de Colônia Microbiana , Enterococcus faecium , Umidade , Salmonella enterica , Salmonella enterica/efeitos dos fármacos , Microbiologia de Alimentos , Contaminação de Alimentos/análise , Humanos , Cebolas/microbiologia , Aço Inoxidável
3.
Food Res Int ; 172: 113209, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37689954

RESUMO

Contamination of Salmonella in chocolate products has caused worldwide outbreaks and recalls. There is a lack of information on the impact of water activity (aw) on the stability of Salmonella in chocolate products during storage and thermal treatments. In this research, the survival and thermal resistance of a Salmonella cocktail (S. Enteritidis PT30, S. Tennessee K4643, S. Typhimurium S544) was examined in different chocolate products (dark chocolate, white chocolate, milk chocolate) at two aw levels (0.25, 0.50) over 12 months at 22 °C. A reduction of 4.19 log10 CFU/gof Salmonella was obtained in dark chocolate after 12 months (aw = 0.50, at 22 °C); less reductions were observed in white and milk chocolates. In all three products, more reductions were observed ataw = 0.50 than at aw = 0.25 over the 12-months storage. When treated at 80 °C, the D-values (time required to cause 1 log reduction) of the Salmonella cocktail in the chocolate samples with initial aw of 0.25 were 35.7, 25.2 and 11.6 min in dark, white and milk chocolate, respectively, before the storage. The D80°C -values of Salmonella cocktail in the samples with initial aw of 0.50 were 6.45, 7.46, and 3.98 min in dark, white and milk chocolate, respectively. After 12 months of storage at 22 °C, the D80°C-value of Salmonella cocktail decreased to 9.43 min (p < 0.05) in milk chocolate but remained 22.7 min in white chocolate with an aw of 0.25 at 22 °C. The data suggests that Salmonella can survive in chocolate products for up to 12 months, and its thermal resistance remained relatively stable. Thus, Salmonella is resistant to desiccation in chocolates, particularly in milk and white chocolates, and its thermal resistance remains during one-year storage, which could pose a potential threat for future outbreaks.


Assuntos
Cacau , Chocolate , Salmonella enteritidis , Surtos de Doenças , Água
4.
Food Microbiol ; 115: 104340, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37567641

RESUMO

Bacterial transfer during postharvest handling of fresh produce provides a mechanism for spreading pathogens, but risk factors in dry environments are poorly understood. The aim of the study was to investigate factors influencing bacterial transfer between yellow onions (Allium cepa) and polyurethane (PU) or stainless steel (SS) under dry conditions. Rifampin-resistant Enterococcus faecium NRRL B-2354 or a five-strain cocktail of Salmonella was inoculated onto onion skin or PU surfaces at high or moderate levels using peptone, onion extract, or soil water as inoculum carriers. Transfer from inoculated to uninoculated surfaces was conducted using a texture analyzer to control force, time, and number of contacts. Transfer rates (ratio of recipient surface to donor surface populations) of E. faecium (4-5%) were significantly higher than those of Salmonella (0.5-0.6%) at the high (7 log CFU/cm2) but not moderate (5 log CFU/cm2) inoculum levels. Significantly higher populations of E. faecium transferred from onion to PU than from PU to onion. The transfer rates of E. faecium were impacted by inoculum carrier (61% [onion extract], 1.6% [peptone], and 0.31% [soil]) but not by inoculation level or recipient surface (PU versus SS). Bacterial transfer during dry onion handling is significantly dependent on bacterial species, inoculation levels, inoculum carrier, and transfer direction.


Assuntos
Enterococcus faecium , Salmonella enterica , Cebolas , Contagem de Colônia Microbiana , Peptonas , Microbiologia de Alimentos , Salmonella , Solo , Extratos Vegetais , Manipulação de Alimentos
5.
Med Sci Monit ; 28: e938637, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36518029

RESUMO

BACKGROUND Endometriosis is a progressive disease, and early detection and early treatment are particularly important. The purpose of this study was to investigate the effect of the timing of laparoscopy on the spontaneous pregnancy rate of primary infertile patients complicated with pelvic effusion within 6 months after surgery. MATERIAL AND METHODS We enrolled 330 primary infertile patients with pelvic effusion and bilateral patent fallopian tubes. They were divided into 3 groups based on retrospective analysis of clinical data. Study Group 1 underwent laparoscopy 1 month after hysterosalpingography (HSG), Study Group 2 received laparoscopy after trying to conceive for 3 months, and the Control Group did not undergo laparoscopy. According to the specific conditions during laparoscopy, repair and plastic surgery of fallopian tube, electrocautery of endometriosis and uterine suspension were performed. The main observation indicators were proportions of retrograde menstruation, peritoneal endometriosis, and tubal adhesions in laparoscopy groups, and spontaneous pregnancy rates within 6 months. RESULTS The proportions of retrograde menstruation were 92.2% and 93.1% in Study Group 1 and Study Group 2, respectively, with no statistical significance. The proportions of peritoneal endometriosis were 51.0% and 64.7%, with a statistically significant difference. The proportions of tubal adhesions were 31.4% and 36.2%, with no statistical significance. The pregnancy rates within 6 months were 73.9%, 52.6%, and 13.1%, with a statistically significant difference for pairwise comparisons. CONCLUSIONS The pregnancy rate of primary infertile patients with patent fallopian tubes complicated with pelvic effusion can be significantly improved through early laparoscopic surgery (exploration and treatment).


Assuntos
Endometriose , Doenças das Tubas Uterinas , Infertilidade Feminina , Laparoscopia , Gravidez , Feminino , Humanos , Tubas Uterinas/cirurgia , Tubas Uterinas/patologia , Doenças das Tubas Uterinas/complicações , Doenças das Tubas Uterinas/cirurgia , Doenças das Tubas Uterinas/diagnóstico , Endometriose/complicações , Endometriose/cirurgia , Endometriose/patologia , Estudos Retrospectivos , Infertilidade Feminina/cirurgia , Laparoscopia/efeitos adversos , Aderências Teciduais/patologia , Distúrbios Menstruais/complicações , Distúrbios Menstruais/patologia , Distúrbios Menstruais/cirurgia
6.
Int J Food Microbiol ; 362: 109494, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-34895752

RESUMO

Water sorption isotherms of bacteria reflect the water activity with the change of moisture content of bacteria at a specific temperature. The temperature-dependency of water activity change can help to understand the thermal resistance of bacteria during a thermal process. Thermal resistance of bacteria in low-moisture foods may differ significantly depending on the physiological characteristics of microorganisms, including cell structure, existence of biofilms, and growth state. Previous studies demonstrated that the incremental change of aw in bacterial cells during thermal treatments resulted in changes in their thermotolerance. In this study, a pathogen associated with low-moisture foods outbreaks, Salmonella Enteritidis PT30 (in planktonic and biofilm forms), and its validated surrogate, Enterococcus faecium, were lyophilized and their water sorption isotherms (WSI) at 20, 40, and 60 °C were determined by using a vapor sorption analyzer and simulated by the Guggenheim, Anderson and De Boer model (GAB). The published thermal death times at 80 °C (D80 °C-values) of these bacteria in low-moisture environments were related with their WSI-derived aw changes. The results showed that planktonic E. faecium and biofilms of Salmonella, exhibiting higher thermal resistance compared to the planktonic cultures of Salmonella, had a smaller increase in aw when thermally treated from 20 to 60 °C in sealed test cells. The computational modeling also showed that when temperature increased from 20 to 60 °C, with an increase in relative humidity from 10% to 60%, freeze-dried planktonic E. faecium and Salmonella cells would equilibrate to their surrounding environments in 0.15 s and 0.25 s, respectively, suggesting a rapid equilibration of bacterial cells to their microenvironment. However, control of bacteria with different cell structure and growth state would require further attentions on process design adjustment because of their different water sorption characteristics.


Assuntos
Microbiologia de Alimentos , Temperatura Alta , Liofilização , Salmonella enteritidis , Água/análise
7.
Appl Environ Microbiol ; 87(3)2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33158899

RESUMO

Salmonella spp. are resilient bacterial pathogens in low-moisture foods. There has been a general lack of understanding of critical factors contributing to the enhanced thermal tolerance of Salmonella spp. in dry environments. In this study, we hypothesized that the moisture content (XW ) of bacterial cells is a critical intrinsic factor influencing the resistance of Salmonella spp. to thermal inactivation. We selected Salmonella enterica serotype Enteritidis PT 30 to test this hypothesis. We first produced viable freeze-dried S. Enteritidis PT 30, conditioned the bacterial cells to different XW s (7.7, 9.2, 12.4, and 15.7 g water/100 g dry solids), and determined the thermal inactivation kinetics of those cells at 80°C. The results show that the D-value (the time required to achieve a 1-log reduction) decreased exponentially with increasing XW We further measured the water activities (aw) of the freeze-dried S. Enteritidis PT 30 as influenced by temperatures between 20 and 80°C. By using those data, we estimated the XW of S. Enteritidis PT 30 from the published papers that related the D-values of the same bacterial strain at 80°C with the aw of five different food and silicon dioxide matrices. We discovered that the logarithmic D-values of S. Enteritidis PT 30 in all those matrices also decreased linearly with increasing XW of the bacterial cells. The findings suggest that the amount of moisture in S. Enteritidis PT 30 is a determining factor of its ability to resist thermal inactivation. Our results may help future research into fundamental mechanisms for thermal inactivation of bacterial pathogens in dry environments.IMPORTANCE This study established a logarithmic relationship between the thermal death time (D-value) of S. Enteritidis PT 30 and the moisture content (XW ) of the bacterial cells by conducting thermal inactivation tests on freeze-dried S Enteritidis PT 30. We further verified this relationship using literature data for S. Enteritidis PT 30 in five low-moisture matrices. The findings suggest that the XW of S. Enteritidis PT 30, which is rapidly adjusted by microenvironmental aw, or relative humidity, during heat treatments, is the key intrinsic factor determining the thermal resistance of the bacterium. The quantitative relationships reported in this study may help guide future designs of industrial thermal processes for the control of S. Enteritidis PT 30 or other Salmonella strains in low-moisture foods. Our findings highlight a need for further fundamental investigation into the role of water in protein denaturation and the accumulation of compatible solutes during thermal inactivation of bacterial pathogens in dry environments.


Assuntos
Salmonella enteritidis/química , Salmonella enteritidis/fisiologia , Termotolerância , Água/análise , Liofilização , Temperatura Alta
8.
Food Chem ; 319: 126597, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32187567

RESUMO

This research explored the application of combined radio frequency and hot air drying (RF-HAD) technology on corn seeds. Drying characteristics and seed vigor were investigated at different RF electrode gaps (140, 150 and 160 mm). To better demonstrate the feasibility of applying RF-HAD on corn seeds, tempering-intermittent hot air drying (HAD) was studied as a comparison. Reduced electrode gap corresponding to elevated average heating rate and power efficiency resulted in decreased seeds vigor and specific energy consumption. The assistance of RF significantly increased the drying rate of corn seeds and reduced drying duration by up to 70% compared with HAD. A higher dehydrogenase activity (DHA) but a lower germination percentage (GP) was observed in RF-HAD samples as compared with HAD ones. Corn seeds were promoted to be dormant by RF-HAD according to dormancy-breaking results and isobaric tags for relative and absolute quantification (iTRAQ) analysis.


Assuntos
Sementes/química , Sementes/fisiologia , Zea mays/química , Dessecação , Germinação , Calefação , Temperatura Alta , Oxirredutases/metabolismo , Dormência de Plantas , Ondas de Rádio , Zea mays/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...