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Biology is a study of living objects and their life processes. It examines all aspects of living organisms such as their occurrence, classification, internal and external structure, nutrition, reproduction, inheritance, etc. The term “biology” is commonly replaced by the terms “life sciences” and “biological sciences.” There are dozens of branches of biology. Some of the major ones include:

Biology and Life Sciences

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Abstract

Nanoparticles can be synthesised by several methods. Due to the long duration, high cost, and toxic by-products of chemical and physical methods, the biological method has become more preferred. Among various sources such as bacteria, fungi, or yeast, the use of plants in biological synthesis has proven to be the most ideal. Many metals can be used in the biological method, including copper oxide (CuO). In this study, copper oxide nanoparticles (CuONPs) were synthesised using Pimpinella anisum L. aqueous extract. For characterisation of the CuONPs, UV–Visible Spectroscopy (UV–Vis), Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FT-IR) analyses were performed. The biological activity of the P. anisum extract and CuONPs was determined using DNA cleavage (agarose gel electrophoresis), antioxidant (1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and hydrogen peroxide scavenging activity), mutagenic (Ames/Salmonella test), and catalytic (methylene blue degradation) activities. In DNA cleavage activity test, CuONPs completely denatured DNA at high concentrations (100 and 200 μg mL−1) due to their oxidative activity. The results showed that both the extract and CuONPs have antioxidant properties in DPPH and hydrogen peroxide scavenging activities. According to the mutagenicity, CuONPs did not have a mutagenic effect. In catalytic activity, CuONPs degraded methylene blue within 240 min by 99.45%.

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Abstract

In this study, the odour values of rosemary, mint, black cumin, lavender, and thyme oils were determined by an electronic nose working with an Arduino microprocessor. The components of the plants were compared with the sensor data, and the most sensitive sensors were determined by sorting according to the highest components. The study data indicated that the MQ3 sensor exhibited the highest sensitivity for thyme, black cumin, and lavender oils, which contain 63% carvacrol, 38% thymoquinone, and 36% linalool, respectively. Also, MQ7 was the most sensitive sensor for menthone (68%) in mint oil and eucalyptol (45%) in rosemary oil. In addition, a low-cost and non-contact device that works with an infrared sensor has been developed to detect the identity of the oil added into the vial. The study data showed that low-cost Arduino-based IR and odour sensors can determine the identity and component percentage of oils. The fact that the developed device can detect with 100 percent accuracy even in case of peppermint and rosemary oils, which are very similar in appearance, shows that the study data will be an inspiration for contactless determination of oil quality and type.

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Abstract

The effect of different drying methods (oven drying, fluid bed drying, and freeze drying) on the fatty acid composition, astaxanthin content, antioxidant activity, and colour values of giant red shrimp (Aristaeomorpha foliacea) processing wastes were investigated. These results showed that freeze drying was the most effective method in preserving the quality of shrimp processing waste (SPW), resulting in higher levels of EPA and DHA, astaxanthin content, antioxidant activity, and desired reddish colour characteristics compared to other methods. These findings highlight the potential of freeze drying as a suitable technique for converting SPW into high value products.

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European Journal of Microbiology and Immunology
Authors:
Juan Diego Ribeiro de Almeida
,
Raissa Sayumy Kataki Fonseca
,
Naira Sulany Oliveira de Sousa
,
Ana Cláudia Alves Cortez
,
Emerson Silva Lima
,
Juliana Gomes de Souza Oliveira
,
Érica Simplício de Souza
,
Hagen Frickmann
, and
João Vicente Braga de Souza

Abstract

Background

The rising prevalence of fungal infections and challenges such as adverse effects and resistance against existing antifungal agents have driven the exploration of new antifungal substances.

Methods

We specifically investigated naphthoquinones, known for their broad biological activities and promising antifungal capabilities. It specifically examined the effects of a particular naphthoquinone on the cellular components of Candida albicans ATCC 60193. The study also assessed cytotoxicity in MRC-5 cells, Artemia salina, and the seeds of tomatoes and arugula.

Results

Among four tested naphthoquinones, 2,3-DBNQ (2,3-dibromonaphthalene-1,4-dione) was identified as highly effective, showing potent antifungal activity at concentrations between 1.56 and 6.25 μg mL−1. However, its cytotoxicity in MRC-5 cells (IC50 = 15.44 µM), complete mortality in A. salina at 50 μg mL−1, and significant seed germination inhibition suggest limitations for its clinical use.

Conclusions

The findings indicate that primary antifungal mechanism of 2,3-DBNQ might involve disrupting fungal membrane permeability, which leads to increased nucleotide leakage. This insight underscores the need for further research to enhance the selectivity and safety of naphthoquinones for potential therapeutic applications.

Open access

Abstract

Tigecycline-resistant Acinetobacter baumannii (TRAB) is increasing in Thailand, complicating antibiotic treatment due to limited antibiotic options. The specific resistance mechanism behind tigecycline resistance is still unclear, necessitating further investigation. We investigated the presence of OXA-type carbapenemases, the antimicrobial susceptibility profile, the inhibitory effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP) on tigecycline susceptibility, the expression levels of RND-type efflux pumps and amino acid substitutions within a two-component regulatory system on 30 Thai clinical isolates. Our investigation revealed that most of (73.3%) TRAB isolates expressed at least one member of the Ade efflux pumps. The ade B was most frequently expressed (63.3%), followed by ade R (50%), ade S (43.3%), ade J (30%) and ade G (10%). Overexpression of the AdeABC was associated with increased tigecycline minimum inhibitory concentrations (MICs) and amino acid substitutions within the AdeRS. Notably, isolates harbouring simultaneous mutations in these genes exhibited an increase in the transcription level of the ade B. Our findings highlight the significant role of the AdeABC system in tigecycline resistance among Thai clinical TRAB isolates. This is supported by point mutations within the AdeRS and upregulated expression of the ade B. These results provide valuable insights for understanding resistance mechanisms and developing novel therapeutic strategies.

Open access

Abstract

The present work aimed to study the yeast communities of whole crop corn silages (CS) that were previously contaminated with aflatoxin-producing Aspergillus flavus (CSCA). In addition, the effect of lactic acid bacterium (LAB) inoculation on the aflatoxin B1 (AFB1) content, genotoxicity, yeast load, and diversity of yeast communities were also investigated. In A. flavus contaminated silages, after two months, the AFB1 content was 40% lower with LAB inoculation, also a lower level of genotoxicity was determined. The number of yeasts cultured from the initial mixture of chopped whole crop corn was 4.8 × 107 CFU g−1 wet mass, while only 2.4 × 106 CFU g−1 from the CSCA and 7.1 × 105 CFU g−1 from the LAB-inoculated CSCA could be cultured. Based on 144 randomly isolated strains, the yeast community of the initial mixture consisted of 8 species. In contrast, the yeast community of CSCA consisted only of 4 species determined by 132 randomly selected isolates. LAB-inoculated CSCA consisted also of 4 species based on 158 randomly isolated strains. Saccharomyces cerevisiae and Pichia kudriavzevii proved to be predominant in the CSCA, while S. cerevisiae and Meyerozyma guilliermondii were the most abundant in the LAB-inoculated CSCA. The species richness was also confirmed by alpha diversity values (1.827, 1.188, and 1.123 as Shannon's indices for CS, CSCA, and LAB-inoculated CSCA, respectively). In response to LAB inoculation, the species diversity decreased considerably.

Open access
Progress in Agricultural Engineering Sciences
Authors:
D. Szám
,
Zs. Hetesi
,
A. P. Takács
,
G. Keve
,
P. Balling
, and
Á. Fekete

Abstract

This study aims to predict drought periods affecting the Tokaj-Hegyalja wine region and the application of this in crop protection. The Tokaj-Hegyalja wine region is the only closed wine region in Hungary with a specific mesoclimate and a corresponding wine grape variety composition, in which climate change strongly threatens cultivation. The probability that a randomly selected day in the vegetation period will fall into a drought period in the future was estimated using the daily precipitation amount and daily maximum temperature data from the Hungarian Meteorological Service for the period 2002–2020. The Markov model, a relatively new mathematical method for the statistical investigation of weather phenomena, was used for this. Markov chains can, therefore, be a valuable tool for organizing integrated pest management. This can be used to plan irrigation, control fungal pathogens infecting the vines, and plan the success of a given vintage.

Open access
European Journal of Microbiology and Immunology
Authors:
Md. Abdur Rob
,
Mohabbat Hossain
,
M.A. Sattar
,
Istiaq Uddin Ahmed
,
Abul Faisal Md. Nuruddin Chowdhury
,
H.M. Hamidullah Mehedi
,
Noor Mohammed
,
Mohammed Maruf ul Quader
,
Md. Zakir Hossain
,
Mustafizur Rahman
,
Kallyan Chakma
,
Susmita Barua
,
Silvia Naznin Etu
,
Uschash Sikder
,
Afroza Akter Tanni
, and
Adnan Mannan

Abstract

Dengue is a serious epidemic for Bangladesh affecting thousands of lives. This study aimed to identify and determine the prevalence of the circulating variants of dengue virus (DENV) and their association with demographics and clinical manifestations among the dengue-infected patients. A total of 711 participants with NS1 antigen positivity were enrolled, followed by viral RNA extraction from the collected blood samples and a multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay to determine the dengue virus serotypes. Of 711 dengue-infected patients, 503 (70.7%) were male. Among different age groups, most of the patients were 21–30 years old (n = 255, 35.9%). The DENV2 (n = 483, 67.9%) serotype was more prevalent than the DENV3 (n = 144, 20.3%) and DENV1 (n = 84, 11.8%). The duration of fever was highest in the DENV-1 patients (4.79 ± 1.84 days) in contrast to DENV-3 (4.48 ± 1.68 days) and DENV-2 (4.33 ± 1.45 days) (P = 0.039). Importantly, five highly populated areas were identified as dengue hotspots in Chittagong metropolitan city. Our results provide crucial insights into the patterns of dengue virus transmission and severity among southern Bangladeshi population, thereby aiding in the development of targeted public health interventions and management strategies to combat future outbreaks.

Open access

Abstract

Food manufacturing and processing are part of the nation's critical infrastructure. Due to the recent global spread of the SARS-CoV-2 virus, the potential contamination of the food chain and the resulting public health implications are of high consequence to society. The current primary food manufacturing and processing facilities already have various mechanisms such as hazard analysis and critical control point (HACCP) system in place. However, the widespread microbial infections in these facilities raise concerns that they will not only threaten the welfare of food processing workers, but also have a potentially greater consequence on the public if the food is contaminated with an infectious agent.

Despite the increasingly recognised role of the environment in the spread of microbes, the effect of air properties remains poorly understood. Heating, ventilation, and air conditioning (HVAC) systems in meat processing facilities not only provide a means of transport for viruses and bacteria but may also deposit them on surfaces where they can survive for days. To maintain a stable and safe food chain supply during the pandemic, the challenges to ensure safe food supply and protect the workers' health must be quickly addressed through sustainable, safe and economic approaches. With these two imminent challenges in mind, the overall goal of this review article is to provide a comprehensive overview of the role of the environment in the impaction and resuspension of bioaerosols, focusing on airborne bacteria and viruses. The review includes the latest results of modeling the spread of microbial aerosols in the airflow and the development of preventive measures to mitigate virus contamination in the unique environment of meat processing operations. By understanding how the environmental factors and seasonality affect the infectivity and spread of airborne pathogens, mitigation measures can be designed to minimise future infections within and beyond these facilities.

Open access

Abstract

The effect of the storage conditions of light (presence; absence) and relative humidity (50%; 75% RH) on the water content and colour of Porphyridium cruentum microalga powder was studied, then two packaging materials, low-density polyethylene (PE-LD) and metallised polyethylene terephthalate with polyethylene (PETmet/PE), were used to study their effect on the water content, colour, total carotenoids and chlorophylls contents, total phenolic content (TPC), and antioxidant activity (ABTS, DPPH, ORAC) of P. cruentum during storage at 23 °C and 50% RH. An atmosphere with 50% RH is recommended to minimise the water vapour absorption and lightness loss. In addition to the expected light protection, PETmet/PE material protected P. cruentum powder also against water absorption, contrary to PE material. There were no relevant colour changes of the microalga during storage in PETmet/PE. Regarding the total content of carotenoids and the antioxidant activity of the microalga, no significant differences were found between the biomasses stored in either packaging material. The TPC and DPPH values were practically constant during two months of storage, while ABTS and ORAC decreased more than 50% and 20%, respectively, during this time.

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