Hasil untuk "Physiology"

D. Wishart

Metabolomics uses advanced analytical chemistry techniques to enable the high-throughput characterization of metabolites from cells, organs, tissues, or biofluids. The rapid growth in metabolomics is leading to a renewed interest in metabolism and the role that small molecule metabolites play in many biological processes. As a result, traditional views of metabolites as being simply the "bricks and mortar" of cells or just the fuel for cellular energetics are being upended. Indeed, metabolites appear to have much more varied and far more important roles as signaling molecules, immune modulators, endogenous toxins, and environmental sensors. This review explores how metabolomics is yielding important new insights into a number of important biological and physiological processes. In particular, a major focus is on illustrating how metabolomics and discoveries made through metabolomics are improving our understanding of both normal physiology and the pathophysiology of many diseases. These discoveries are yielding new insights into how metabolites influence organ function, immune function, nutrient sensing, and gut physiology. Collectively, this work is leading to a much more unified and system-wide perspective of biology wherein metabolites, proteins, and genes are understood to interact synergistically to modify the actions and functions of organelles, organs, and organisms.

O. Lange, P. S. Nobel, C. Osmond et al.

S. Rothman

H. L. Borison, S. C. Wang

E. Stellar

R. Dow, G. Moruzzi

Meirion Thomas

Pankratov Fedor, Panasenkov Dmitry, Kartashov Aleksandr et al.

The article presents a research of the lubricity of the elements of the mechatronic transmission of an energy efficient truck. Particular attention is paid to the processes associated with ensuring reliable operation of the transmission and reducing friction between the components. Analysis of the distribution of fluids, performed using the SPH method, allows us to determine the lubricity conditions to improve performance characteristics, as well as reduce the temperature of the mechanisms to increase the service life and improve the overall efficiency of the system. The results of the research demonstrate the importance of choosing lubricants and their application modes, which directly affects the durability of transmission elements and the energy efficiency of the entire vehicle. These findings can serve as a basis for developing recommendations for optimizing the operation of mechatronic transmissions of cars.

A Madinu Abd Malik, Jouhary Naufal Amir, Ulfa Aulia et al.

This study aims to better understand the coastal dynamics along the 6.89 km of Subang shoreline using Landsat data and GIS methods with cloud computing-based analysis. The data is processed using remote sensing techniques, image classification, and change detection algorithms. Furthermore, this research harnesses cloud computing to efficiently manipulate big data, enabling rapid and measurable analysis of coastline changes. Cloud computing-based platforms facilitate data storage, processing, and dissemination, enhancing accessibility for researchers and stakeholders. This study indicates that the area has experienced significant changes from 1990 to 2023, with the total length of the coastlines that have changed (positive stands for accretion and negative for erosion) being 8.21 km (-16,86 %) for 1990 to 2000, 6.52 km (16.21%) for 2000 to 2010, 8.14 km (6,66%) for 2010 to 2020, and 8.81 km (-19,16%) for 2020 to 2023. The results provide valuable information about erosion, accretion, and coastal morphological changes. The findings can help make informed decisions for sustainable coastal management. The methodology presented in this article demonstrates a solid approach to coastline monitoring that can be replicated in other areas for more efficient and effective coastal management and environmental preservation.

Melkumyan Anahit, Sahakyan Maria

This article aims to identify the factors that influence the academic performance of undergraduate students, focusing on digital literacy, digital knowledge and skills, as well as personal characteristics in the digital economy. To identify these relationships, surveys were conducted among students using appropriate online questionnaires, and the Big Five Personality Traits (BFPT) testing methodology was chosen to assess the personal qualities of undergraduate students. The findings of the study are consistent with the research in the field indicating a correlation between digital skills and student academic success and simultaneously the inverse impact of social media on academic performance. In addition, the study showed that there is also a positive relationship between some personal traits as conscientiousness, agreeableness and academic performance outcomes. Research illustrates the significant role of gender in academic achievement, explaining how differences in male and female personality traits can influence academic performance and adaptability. The results confirm that academic success and, thus, the ability to adapt to the changing conditions can be explained by personal traits and digital technologies used while the other possible factors can include gender, professional and cultural background.

Flavia G. Costa, Krista B. Mills, Heidi A. Crosby et al.

ABSTRACTStaphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%–30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin.IMPORTANCEStaphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.

Iriani Dian, Hasan Bustari, Warningsih Trisla et al.

Probiotics are microorganisms that have benefits when consumed, they can be found in yogurt. Yogurt commercially lack protein; the addition of chlorella is a solution due to chlorella contains high protein. The research aimed to determine the effect of chlorella fortification on the quality characteristics of yogurt and the best concentration of chlorella addition in the manufacturing of yogurt. The experimental method using a non-factorial Completely Randomized Design (CRD) consisting of 4 treatment levels: without the addition of chlorella (PC0), 0.75% of chlorella (PC1), 1% of chlorella (PC2), and 1.25% of chlorella (PC3). The parameters tested in this research were hedonic testing and quality, chemical composition, physical properties, and microbiological assay. The results showed that yogurt fortified with 1% chlorella was most favorable by consumer acceptance, with organoleptic characteristics: green and thick color, slightly characteristic aroma of chlorella, and slightly sour taste typical of chlorella. Meanwhile, the proximate composition of this yogurt contains 81.26% moisture, 3.77% protein, 2.30% fat, 0.89% ash, 1.47% fiber; physical properties of pH 4.65, Aw 0.75, viscosity 205.85 cP; and microbiological value of acid total 1.95%, and lactic acid bacteria 2.1×107 cfu/g. Therefore, the yogurt chlorella is suitable for consumption and can enhance health benefits.

R. Pitts, J. Jacoby

H. L. Short, D. C. Church

Hania Benmebarek, Karima Kharroub

Halophiles are microorganisms that inhabit saline and hypersaline environments, requiring salinity to survive in such extreme conditions. These microorganisms are mainly researched for their biotechnological potential. This study aims to investigate the phenology of the studied strain, <i>Idiomarina loihiensis</i>, and to demonstrate its extracellular proteolytic activity, as well as the production of a protease via batch fermentation in halophilic microorganisms. Macroscopic studies revealed small colonies (≤5 mm) with a convex spherical structure, regular outline, smooth surface, and color ranging from beige to opaque cream. Protease production was investigated in high-salinity conditions with a moderately halophilic bacterium using basal media with varying nitrogen sources. This study found that the highest proteolytic activity occurred in media with tryptone and casein peptone as nitrogen sources, at pH 10, a temperature of 70 °C, and 22.5% salt concentration. The results also demonstrated that the studied protease was a thermostable enzyme.

Maryam Sharifi, Shahrbanoo Oryan, Alireza Komaki et al.

There is growing evidence that the hippocampus comprises diverse neural circuits that exhibit longitudinal variation in their properties, however, the intermediate region of the hippocampus has received comparatively little attention. Therefore, this study was designed to compared short- and long-term synaptic plasticity between the dorsal and intermediate regions of the hippocampus in normal and PTZ-kindled rats. Short-term plasticity was assessed by measuring the ratio of field excitatory postsynaptic potentials’ (fEPSPs) slope in response to paired-pulse stimulation at three different inter-pulse intervals (20, 80, and 160 ms), while long-term plasticity was assessed using primed burst stimulation (PBS). The results showed that the basal synaptic strength differed between the dorsal and intermediate regions of the hippocampus in both control and kindled rats. In the control group, paired-pulse stimulation of Schaffer collaterals resulted in a significantly lower fEPSP slope in the intermediate part of the hippocampus compared to the dorsal region. Additionally, the magnitude of long-term potentiation (LTP) was significantly lower in the intermediate part of the hippocampus compared to the dorsal region. In PTZ-kindled rats, both short-term facilitation and long-term potentiation were impaired in both regions of the hippocampus. Interestingly, there was no significant difference in synaptic plasticity between the dorsal and intermediate regions in PTZ-kindled rats, despite impairments in both regions. This suggests that seizures eliminate the regional difference between the dorsal and intermediate parts of the hippocampus, resulting in similar electrophysiological activity in both regions in kindled animals. Future studies should consider this when investigating the responses of the dorsal and intermediate regions of the hippocampus following PTZ kindling.

Kevin O. Murray, Sophia A. Mahoney, Ravinandan Venkatasubramanian et al.

Age-associated cardiovascular (CV) dysfunction, namely arterial dysfunction, is a key antecedent to the development of CV disease (CVD). Arterial dysfunction with aging is characterized by impaired vascular endothelial function and stiffening of the large elastic arteries, each of which is an independent predictor of CVD. These processes are largely mediated by an excess production of reactive oxygen species (ROS) and an increase in chronic, low-grade inflammation that ultimately leads to a reduction in bioavailability of the vasodilatory molecule nitric oxide. Additionally, there are other fundamental aging mechanisms that may contribute to excessive ROS and inflammation termed the “hallmarks of aging”; these additional mechanisms of arterial dysfunction may represent therapeutic targets for improving CV health with aging. Aerobic exercise is the most well-known and effective intervention to prevent and treat the effects of aging on CV dysfunction. However, the majority of mid-life and older (ML/O) adults do not meet recommended exercise guidelines due to traditional barriers to aerobic exercise, such as reduced leisure time, motivation, or access to fitness facilities. Therefore, it is a biomedical research priority to develop and implement time- and resource-efficient alternative strategies to aerobic exercise to reduce the burden of CVD in ML/O adults. Alternative strategies that mimic or are inspired by aerobic exercise, that target pathways specific to the fundamental mechanisms of aging, represent a promising approach to accomplish this goal.

Ali Choopani, Fatemeh Matoofi, Ali Karami et al.

Molecular biology plays an important role in understanding the structures, functions and internal controls within each cell. All this can be used to diagnose the diseases, effectively target new medicines and better understand cellular physiology. The bacteria that cause Lyme disease are difficult to observe directly in body tissues and too time-consuming to grow in the laboratory. Lyme disease can affect several body systems and produce a broad range of symptoms. Not everybody with Lyme disease has all the symptoms and many of the symptoms are not specific but may occur with other diseases. Common laboratory diagnostic methods have many false positive results in contaminated areas. These problems have made scientists think of finding accurate and fast methods to diagnose. The accuracy and precision of molecular biological methods have made an important field of research to identify the pathogen of this disease. Borrelia Burgdorferi is a species of the Spirochaeta order and Borrelia genus. This type of Gram-negative bacteria is the most important cause of Lyme disease. Five of these species, Borrelia afzeli, Borrelia garinii, Borrelia bavariansis, Borrelia bergdorferi senses strict, and Borrelia spirmani, have been described as causative agents of Lyme disease in humans. There are 36 known Borrelia species. In the Borrelia family, three species cause Lyme disease or borreliosis, the most important cause in USA is Borrelia Burgdorferi and the main cause in Europe are Borrelia afzelii and Borrelia garinii. Accurate molecular tests are designed for specific detection and isolation of strains. This study was conducted by reviewing 131 related articles from Scopus, ISI and PubMed databases. Finally, methods for designing accurate molecular tests to identify disease agents were reported.

J. Lebensohn