Metabolic Rate Research Articles

Determining the thermal comfort of naturally ventilated state colleges located in Madhya Pradesh, India

ABSTRACT Through the establishment of optimal thermal conditions, educational institutions can develop an environment favourable to learning, concentration, and academic achievements. Additionally, comfortable temperatures can contribute to the overall well-being and satisfaction of both students and teachers, fostering a positive educational experience. In this study, we aimed to determine the impacts of environmental factors on students’ thermal comfort in three state colleges of Madhya Pradesh. A total of 784 students participated in a questionnaire study conducted during May (Summer season), August (Monsoon season), October (Autumn season), and December (Winter season) of 2023 to assess occupants’ degree of clothing, temperature preference, and metabolic rates. Indoor and outdoor temperatures, relative humidity, and air velocity were measured using an anemometer. Throughout the study period, the thermal comfort range was determined to be between 21.5°C and 28.5°C, with 25°C as the neutral temperature. It has been noted that the clothing pattern varies during the year (0.47-0.85 Clo). Additionally, implementation of the adaptation strategies, such as switching on and off fans or opening windows, helped lessen discomfort in the classroom. The findings indicate that, in contrast to the other seasons, the summers brought exceptionally high levels of heat discomfort to the occupants.

Appearance time of blood in the brain as a possible indicator of oxygen extraction fraction: a feasibility study

BackgroundImaging examination of cerebral blood flow (CBF), oxygen extraction fraction (OEF), and metabolic rate of oxygen is crucial for understanding the normal functioning and pathophysiology of the brain. A recently developed method estimates the appearance time of cerebral blood (ATB) pixel-wise from the imaging examination of CBF alone. In this study, we aimed to test the potential of ATB as an indicator of OEF.ResultsWe retrospectively reviewed patients (n = 62) with suspected cerebrovascular disorders including steno-occlusive disease who underwent positron emission tomography (PET) with 15O-labelled tracers. Regarding the generated OEF and ATB images, a visual assessment was performed to test the consistency of the elevated OEF and delayed ATB. The OEF and ATB values and the absolute differences between their ipsilateral and contralateral sides were extracted and obtained for the entire hemisphere and the middle, anterior, and posterior cerebral arterial regions. Consistency was observed in 52 PET scans (83.9%) in visual assessment. The OEF and ATB values were moderately correlated (r = 0.553, p < 0.001), and the differences between their ipsilateral and contralateral sides were weakly correlated (r = 0.276, p < 0.001).ConclusionOur results indicate the potential of ATB as an indicator of OEF.

Oral rehydration in diarrhea: from history to current guidelines. A review

Acute gastroenteritis (AGE) is usually defined as a change in stool consistency (liquid or unformed) and/or an increase in the frequency of bowel movements, which can also be accompanied by vomiting and fever. Fever increases the metabolic rate by more than 1.5 times; for every 1°C increase in body temperature, fluid loss increases by 10%. AGE is a common cause of morbidity and mortality among infants and children. The prognosis is favorable if the condition is recognized promptly and appropriate treatment is started. The main goal of AGE therapy is to restore water balance and prevent dehydration, which can be achieved with an oral rehydration solution. The composition and proportion of the components of rehydration agents are described in the guidelines of the European Society for Paediatric Gastroenterology Hepatology and Nutrition, of which the Russian Society of Pediatric Gastroenterologists is a collective member, and such agents are fully consistent with the balanced formulations of RehydroStandard and Rehydron Bio rehydration agents. The latter includes the probiotic strain Lactobacillus rhamnosus GG, well studied and recommended by the European Society for Paediatric Gastroenterology Hepatology and Nutrition for acute intestinal infections since this strain reduces the duration and severity of diarrhea according to the results of studies. Rehydron Bio and RehydroStandard can be recommended for use in clinical pediatric practice.

Antibiotic biocompatibility assay and anti-biofilm strategies for Pseudomonas aeruginosa infection in bioengineered artificial skin substitutes.

Bioengineered artificial skin substitutes (BASS) are an advanced therapy for treating extensively burned patients. Pseudomonas aeruginosa (P. aeruginosa) infections represent a major challenge in these patients as formation of biofilms impede wound healing and perpetuate a chronic inflammatory state. Here we assessed antibiotics (alone or in combination) with respect to cytotoxicity, as well as antimicrobial efficacy in P. aeruginosa biofilm formed on infection of BASS. Cell viability, structure and functionality were evaluated using microscopy and trans-epidermal water loss analyses, respectively. BASS were established and infected for 24 h to allow P. aeruginosa biofilm formation, after which two antimicrobial approaches, treatment and prevention, were tested. In the latter, antibiotics were added to BASS before infection. The antimicrobial effect was determined using real-time calorimetry. In dose-response experiments, 1.25 mg/mL amikacin, 0.02 mg/mL ciprofloxacin, 0.051 mg/mL colistin, 1 mg/mL meropenem and colistin in combination with either amikacin, ciprofloxacin and meropenem did not affect BASS' viability, structure and functionality. All antibiotics, except colistin, showed effective antimicrobial activity at these non-cytotoxic concentrations. For concentrations below the highest non-cytotoxic ones, successive treatments resulted in higher bacterial metabolic rates. Only the combinations managed to eradicate the infection with repeated treatments. With respect to prevention of infection, all antibiotics at the highest non-cytotoxic concentrations and the combinations were effective. This preventive capacity was maintained for at least 5 days. The findings highlight the potential for developing BASS with antimicrobial properties that can prevent infections during wound healing in burn patients.

The hearts of large mammals generate higher pressures, are less efficient and use more energy than those of small mammals.

A prevailing assumption in the cardiovascular field is that the metabolic rate of the heart is a constant proportion of a mammal's whole-body aerobic metabolic rate. In this Commentary, we assemble previously published cardiovascular, metabolic and body mass data from matched terrestrial mammalian species, at rest and during heavy exercise, and reveal scaling relationships that challenge this assumption. Our analyses indicate that the fractional metabolic cost of systemic perfusion compared with whole-body metabolic rate increases significantly with body size among resting mammals, from ∼2.5% in a mouse to ∼10% in an elephant. We propose that two significant body size-dependent effects contribute to this conclusion; namely, that larger species generate higher mean systemic arterial blood pressure and that their myocardium operates with lower external mechanical efficiencies compared with those of smaller species. We discuss potential physiological and mechanical explanations, including the additional energy needed to support the arterial blood column above the heart in larger species, especially those with long necks, as well as the possible sources of greater internal energy losses from the heart of larger species. Thus, we present an updated view of how increasing blood pressure and decreasing efficiency of the myocardium result in an increasing fractional metabolic cost of perfusion as body size increases among resting mammals.

Effect of dietary calcium and vitamin D supplements on plasma bone turnover biomarkers, bone mineralization, bone strength, and lameness score in gilts.

This study investigated the impact of calcium (Ca) and vitamin D supplements on bone metabolism, bone measurement, lameness, and selection rate in gilts fed five dietary treatments. Two Ca levels (6.85/6.42 [adequate; ACa] or 8.99/8.56 [high; HCa] g/kg) were combined with either 856 IU/kg vitamin D3 (Danish feeding standards; adequate; AD3) or 50 μg/kg 25-hydroxyvitamin D3 (high; HHyD) to create ACaAD3, HCaAD3, ACaHHyD, and HCaHHyD diets. The values 6.85/6.42 and 8.99/8.56g/kg correspond to adequate and high Ca supply for gilts weighing 32 to 100 and 100 to 180kg body weight (BW), respectively. The fifth diet was a combination of HCa and 2,000 IU/kg vitamin D3 (high; HD3) to create HCaHD3. Two hundred gilts were phase fed the dietary treatments from 32 to 100 and 100 to 180kg BW until they were slaughtered, either at 100 or 180kg BW. The gilts were weighed fortnightly, and plasma and urine samples were collected at 100 and 180kg BW. At slaughter, the 2nd and 3rd metacarpal bones were collected for bone parameters measurements. Lameness and selection rate were assessed within the last 7 d at 100 and 180kg BW. Dietary treatments did not affect gilts' growth performance and plasma concentration of Ca, but urinary concentration of Ca was greater in HCa-supplemented gilts at both 100 (P = 0.003) and 180 (P = 0.05) kg BW. Plasma concentration of vitamin D3 (P < 0.001) and 25-hydroxyvitamin D3 (P < 0.001) showed dose-dependent responses at both 100 and 180kg BW. Bone-specific alkaline phosphatase was greater (P = 0.02) in the plasma sample collected at 180kg BW in gilts fed the HCaHD3 diet and tended to be greater in gilts fed the ACaAD3 diet (P = 0.06). The bone ash content (P = 0.02) was greater in gilts fed the HCaAD3 diet and slaughtered at 100kg BW compared with gilts fed the ACaAD3 and ACaHHyD diets. However, bone weight, length, thickness, dry matter, and mineral content did not differ among the dietary treatments at both 100 and 180kg BW (P > 0.05). Neither lameness nor selection rate was affected by the dietary treatments. The average daily gain of gilts weighing 32 to 100 and 100 to 180kg BW showed a positive correlation with bone strength (r = 0.37; P < 0.001) and bone ash content (r = 0.24; P = 0.02), respectively. In conclusion, higher Ca and vitamin D3 supplementation slightly increased bone ash content but had no effect on lameness or selection rate of the gilts compared to those fed according to the Danish nutrient standards.

Investigating the metabolism of four sulfonamides in grass carp via HPLC-MS for screening candidate materials of matrix reference material

An efficient, sensitive, and precise method for investigating the metabolism of four sulfonamides in grass carp has been established using high-performance liquid chromatography-mass spectrometry. By optimizing the experimental conditions, the method achieved a coefficient of determination above 0.999, with detection and quantification limits set at 0.5 μg/kg and 1.0 μg/kg, respectively. Recovery rates were between 92.90 % and 102.84 %, and relative standard deviations ranged from 1.70 % to 9.83 %, enabling the precise detection of these sulfonamides in grass carp tissue. The factors affecting the metabolic rate during the medicated bath process were investigated, and obtained the optimal parameter conditions for screening the candidate materials. The candidate materials screened through this method exhibit good stability when used to prepare matrix standard substances, this work not only provides a scientific basis for screening sulfonamide candidate materials but also offers insights for developing other matrix reference materials.

Comprehensive Review on BMI, TDEE, BMR, and Calories for Weight Management: Insights into Energy Expenditure and Nutrient Balance for Long-Term Well-Being

Body Mass Index (BMI) is a basic tool for assessing body mass based on height and weight, classifying individuals in BMI categories as underweight, normal, overweight, or obese. However, it has limitations as it overlooks muscle mass and fat distribution. Total Daily Energy Expenditure (TDEE) plays a crucial role in measuring the current maintenance calories, surplus calories for weight gain, and deficit calories for weight loss associated with Bansal Metabolic Rate (BMR) and Physical Activity Level (PAL). TDEE is related to 3 phases incline, stable, and decline according to age groups. Keeping these parameters, the current review focused on BMI, TDEE, BMR and calories. Calories are essential for understanding the energy the body stores and uses, making them a key factor for weight management. Macronutrients such as carbohydrates, proteins, and fats provide different amounts of energy, which can impact insulin levels and trigger cravings. Tools like BMI and BMR are useful, but focusing solely on counting calories is not enough for effective weight management. A sustainable approach includes understanding how the body processes different foods, choosing nutrient-rich options, regulating blood sugar, and staying physically active are discussed. This work reveals the long-term well-being for weight management via focused on BMI, TDEE, BMR and calories.

Coronary circulation enhances the aerobic performance of wild Pacific salmon.

Female Pacific salmon often experience higher mortality than males during their once-in-a-lifetime up-river spawning migration, particularly when exposed to secondary stressors (e.g. high temperatures). However, the underlying mechanisms remain unknown. One hypothesis is that female Pacific salmon hearts are more oxygen-limited than those of males and are less able to supply oxygen to the body's tissues during this demanding migration. Notably, female hearts have higher coronary blood flow, which could indicate a greater reliance on this oxygen source. Oxygen limitations can develop from naturally occurring coronary blockages (i.e. coronary arteriosclerosis) found in mature salmon hearts. If female hearts rely more heavily on coronary blood flow but experience similar arteriosclerosis levels as males, they will have disproportionately impaired aerobic performance. To test this hypothesis, we measured resting (RMR) and maximum metabolic rate (MMR), aerobic scope (AS) and acute upper thermal tolerance in coho salmon (Oncorhynchus kisutch) with an intact or artificially blocked coronary oxygen supply. We also assessed venous blood oxygen and chemistry (cortisol, ions and metabolite concentrations) at different time intervals during recovery from exhaustive exercise. We found that coronary blockage impaired MMR, AS and the partial pressure of oxygen in venous blood (PvO2) during exercise recovery but did not differ between sexes. Coronary ligation lowered acute upper thermal tolerance by 1.1°C. Although we did not find evidence of enhanced female reliance on coronary supply, our findings highlight the importance of coronary blood supply for mature wild salmon, where migration success may be linked to cardiac performance, particularly during warm water conditions.

Modulators of Energy Expenditure Accuracy in Adults with Overweight or Obesity: E-MECHANIC Secondary Analyses.

American College of Sports Medicine (ACSM) metabolic equations are used to estimate energy expenditure (EE) of physical activity and prescribe aerobic exercise to meet EE requirements. Limited evidence supports their accuracy in sedentary adults with overweight or obesity during controlled exercise interventions. The purpose of this study was to compare EE estimated by the ACSM walking equation versus EE measured by indirect calorimetry during a 24-week aerobic exercise intervention, and identify potential modulators for their accuracy. Data from the exercising groups (8 or 20 kcal·kg body weight-1·week-1) of the E-MECHANIC study were utilized in this ancillary analysis (N = 103). Every 2 weeks for the initial 8 weeks and monthly thereafter, EE was measured via indirect calorimetry during absolute (2 mph, 0% grade) and relative (65-85% VO2peak) workload exercise. Resting metabolic rate, VO2peak, and body composition were assessed at baseline and follow-up. An EE offset factor (EOF) was calculated to express measured EE as a percentage of the estimated EE at each workload (EOF < 100% represents an overestimation of ACSM estimated EE). The accuracy of the equation decreased with increasing exercise workload (0.44%, 9.2%, and 20.3% overestimation at absolute, relative, and maximal workloads, respectively, at baseline) and overestimation of EE was greater after the exercise intervention. Furthermore, race, sex, age, fat mass, and VO2peak were identified as modulators for equation accuracy. Greater overestimation of EE was observed in Black compared to white females, particularly at lower exercise workloads. These findings support future efforts to improve the accuracy of metabolic equations, especially in diverse populations. Researchers should account for exercise efficiency adaptations when using metabolic equations to prescribe exercise precisely.

NUTRIFLEX

The NUTRIFLEX project is a comprehensive AI-powered application designed to provide personalized nutrition and health management solutions. The goal of the project is to assist individuals in optimizing their diet based on their unique biological and emotional needs, including gut health, mood, and overall well-being. By combining artificial intelligence (AI) and user input, NUTRIFLEX offers tailored meal plans, calorie predictions, mood-enhancing food recommendations, and a gamified approach to motivate users to maintain a healthy lifestyle. The problem addressed by NUTRIFLEX is the growing challenge people face in maintaining a balanced and healthy diet. Modern lifestyles, characterized by fast-paced routines and unhealthy food choices, contribute to poor physical and mental health. Many individuals struggle to find the right balance between their nutritional intake and their health goals, whether it's weight loss, muscle gain, or general wellness. Furthermore, gut health, which plays a critical role in overall health, is often neglected in conventional meal planning applications. Mood fluctuations also significantly impact people's food choices, leading to stress eating or energy dips. NUTRIFLEX solves these problems by offering a holistic, AI-driven solution that adapts to users' unique needs. By using machine learning models, NUTRIFLEX predicts the calorie content of meals and creates personalized meal plans based on user-specific data such as Basal Metabolic Rate (BMR) and Total Energy Expenditure (TEE). The application also provides mood-based meal suggestions, helping users manage their emotional state through food choices that boost energy, focus, and relaxation. One of the most innovative features of NUTRIFLEX is its gut health functionality. By allowing users to input microbiome data, the app generates personalized meal recommendations designed to improve gut health, which in turn enhances overall physical and mental well-being. This focus on gut health distinguishes NUTRIFLEX from traditional meal planners. In addition, NUTRIFLEX integrates gamification to keep users engaged and motivated. Users can set health goals, track their progress, and earn rewards, making the health journey enjoyable and sustainable.

KAWANKULINER: PERSONALISED FOOD RECOMMENDATION APP USING BMR AND TDEE FOR OPTIMAL DAILY NUTRITION

People often have difficulty in determining the type of food that is suitable for the composition of their body. This is due to the many types of food available, as well as the lack of information about the nutritional content of each type of food. By fulfilling the daily calorie and macro-nutrient needs required by the body, its metabolism can be maintained, preventing various health problems such as malnutrition. Based on the results of the Basic Health Research in 2018 malnutrition is one of the most serious problems in Indonesia. Several studies related to calculating calorie estimates using the BMR approach with the utilization of technology have been conducted.However, these studies were limited to only displaying the amount of daily calorie needs that were not accompanied by what foods were needed to meet these daily needs. The purpose of this research is to build an app to help individuals understand their daily calorie needs based on their Basal Metabolic Rate (BMR) and total daily expenditure energy (TDEE), using smart scale to provide body composition information and spoonacular API to provide food recommendations that match their energy needs and give them recipes on how to make their food meanwhile waterfall model is used as a software development method. The test results show that the app meets the functional and usability requirements well, with a high accuracy rate of 99.86% for calories, protein, fat, and carbohydrates. In terms of user response, 13 respondents had a very positive response, and considered the app useful for making it easier to get information about their calorie and macro-nutrient needs, as well as provide food recommendations based on their daily needs.

Assessment of heart rate measurements by commercial wearable fitness trackers for early identification of metabolic syndrome risk

Metabolic syndrome increases the risks of cardiovascular diseases, type 2 diabetes, and certain cancers. The early detection of metabolic syndrome is clinically relevant, as it enables timely and targeted interventions. In the current study, we aimed to investigate the association between metabolic syndrome and heart rate measured using wearable devices in a real-world setting and compare this association with that for clinical resting heart rate. Data from 564 middle-aged adults who wore wearable devices for at least 7 days with a minimum daily wear time of 20 h were analyzed. The results showed significantly elevated all-day, sleeping, minimum, and inactive heart rates in men with pre-metabolic or metabolic syndrome compared with those in normal individuals, whereas sleeping heart rate and heart rate dips were significantly increased and decreased, respectively, in women with metabolic syndrome. After adjusting for confounders, every 10-beats-per-minute increment in all-day, sleeping, minimum, and inactive heart rates in men corresponded to odds ratios of 2.80 (95% confidence interval 1.53–5.44), 3.06 (1.57–6.40), 4.21 (1.87–10.47), and 3.09 (1.64–6.29), respectively, for the presence of pre-metabolic or metabolic syndrome. In women, the association was significant only for heart rate dips (odds ratio = 0.49 [95% confidence interval 0.25–0.96] for every 10% increment). Models incorporating inactive or minimum heart rate in men and heart rate dip in women demonstrated better fits, as indicated by lower Akaike information criterion values (170.3 in men and 364.9 in women), compared with models that included clinical resting heart rate (173.4 in men and 369.1 in women). These findings suggest that the heart rate indices obtained from wearable devices may facilitate early identification of metabolic syndrome.

Respiratory Intervals and Swimming Speed as Remotely Sensed Health Metrics in Free-Ranging Killer Whales (Orcinus orca).

Respiratory rate (mean number of breaths per minute) and respiratory interval (mean time between breaths) can offer insight into a diving mammal's activity state, metabolic rate, behavior, and synchronization due to social cohesion. Also, respiratory rate can reflect an individual animal's health and has the potential to be an informative remotely assessed health metric for monitoring individual animal health in endangered whale species and populations such as southern resident killer whales (Orcinus orca). Using data collected from noninvasive, land-based theodolite tracking, we analyzed swimming speed and surfacing intervals (i.e., mean dive time or mean time between breaths) from 20,613 surfacings of 98 individuals from two populations of the fish-eating, resident killer whale ecotype, namely, one growing (northern resident) and one declining and endangered (southern resident) population. Focal animal sampling was used to measure behavior of individuals of known age and sex in various activity states. Our objective was to evaluate variability and generate normal ranges for respiratory intervals and swimming speeds for killer whales of the Northeast Pacific Ocean resident, fish-eating ecotype to identify baseline respiratory intervals. We found that median respiratory intervals for fish-eating killer whales were between 26 and 29 s for all activity states and that swimming speeds varied by activity state. Median swimming speeds were similar for foraging and traveling (1.6 and 1.7 m/s, respectively), but were significantly slower during resting (1.1 m/s) and social activity (1.3 m/s) states. Three southern resident killer whales in poor body condition (had body condition scores in the lowest 20th percentile of the population) swam at reduced speeds and had shorter median respiratory intervals than outwardly healthy whales of similar age and sex. Respiratory rates, respiratory intervals, and swimming speeds are valuable remotely sensed metrics of health for free-swimming killer whales, especially when combined with other metrics as is the standard in veterinary examinations.

Любопитно и полезно за храните и напитките

The article presents a combined, shared pedagogical practice implemented in two parts: a shared project-based practice “Curious and useful tips for food and drink” in grade VIII and an extracurricular school practice “Week of healthy foods and nutrition” for high school students. The practice is a way to inform, increase competences, build a model for a critical choice of food and drinks and for a balanced, complete, high-quality, regular and healthy diet of teenagers. Students learn to use digital health and energy calculator applications, calculate BMI (body mass index) and BEE (basal energy metabolism), determine their health status in relation to food and nutrition, combine foods correctly, create personal nutrition programs, select foods according to your blood type and their color. In “Healthy Foods and Nutrition Week”, students participate in various competitions, learn about the science of nutrition, carving techniques, design and presentation of healthy foods and traditional foods from European countries. The practice builds up the knowledge, skills and habits of the students of Professional School of Design “Elisaveta Vazova” for healthy eating and a healthy lifestyle.

Non-additivity of the functional properties of individual P450 species and its manifestation in the effects of alcohol consumption on the metabolism of ketamine and amitriptyline

To explore functional interconnections between multiple P450 enzymes and their manifestation in alcohol-induced changes in drug metabolism, we implemented a high-throughput study of correlations between the composition of the P450 pool and the substrate saturation profiles (SSP) of amitriptyline and ketamine demethylation in a series of 23 individual human liver microsomes preparations from donors with a known history of alcohol consumption. The SSPs were approximated with linear combinations of three Michaelis-Menten equations with globally optimized KM (substrate affinity) values. This analysis revealed a strong correlation between the rate of ketamine metabolism and alcohol exposure. For both substrates, alcohol consumption caused a significant increase in the role of the low-affinity enzymes. The amplitudes of the kinetic components and the total rate were further analyzed for correlations with the abundance of 11 major P450 enzymes assessed by global proteomics. The maximal rate of metabolism of both substrates correlated with the abundance of CYP3A4, their predicted principal metabolizer. However, except for CYP2D6 and CYP2E1, responsible for the low-affinity metabolism of ketamine and amitriptyline, respectively, none of the other potent metabolizers of the drugs revealed a positive correlation. Instead, in the case of ketamine, we observed negative correlations with the abundances of CYP1A2, CYP2C9, and CYP3A5. For amitriptyline, the data suggest inhibitory effects of CYP1A2 and CYP2A6. Our results demonstrate the importance of functional interactions between multiple P450 species and their decisive role in the effects of alcohol exposure on drug metabolism.

Near maximally swimming schoolmaster snapper (Lutjanus apodus) have a greater metabolic capacity, and only a slightly lower thermal tolerance, than when tested at rest.

To assess the relationship among various measures of thermal tolerance and performance suggested for use in fish, we determined the critical thermal maximum (CTmax), Ucrit, maximum thermal tolerance while swimming [CTSmax] and realistic aerobic scope (ASR) of juvenile schoolmaster snapper (Lutjanus apodus). Their CTSmax (37.5±0.1°C) was only slightly lower than their CTmax (38.9±0.1°C), and this is likely because their maximum metabolic rate (MMR) and ASR during the former test were∼42 and 65% higher, respectively. Further, we did not observe a transition to unsteady (i.e., anaerobically fueled) swimming in the CTSmax test as we did in the Ucrit protocol. These data strongly suggest that thermal tolerance tests on fishes whose lifestyle involves schooling or sustained activity should be performed at ecologically-relevant swimming speeds. Further, they do not support the hypothesis that failure during a CTSmax test is due to a fish's inability to meet its tissue oxygen demands.

Impaired brain glucose metabolism in glucagon-like peptide-1 receptor knockout mice

BackgroundQuantitative mapping of the brain’s metabolism is a critical tool in studying and diagnosing many conditions, from obesity to neurodegenerative diseases. In particular, noninvasive approaches are urgently required. Recently, there have been promising drug development approaches for the treatment of disorders related to glucose metabolism in the brain and, therefore, against obesity-associated diseases. One of the most important drug targets to emerge has been the Glucagon-like peptide-1 (GLP-1) and its receptor (GLP-1R). GLP and GLP-1R play an important role in regulating blood sugar and maintaining energy homeostasis. However, the macroscopic effects on brain metabolism and function due to the presence of GLP-1R are unclear.MethodsTo explore the physiological role of GLP-1R in mouse brain glucose metabolism, and its relationship to brain function, we used three methods. We used deuterium magnetic resonance spectroscopy (DMRS) to provide quantitative information about metabolic flux, fluorodeoxyglucose positron emission tomography (FDG-PET) to measure brain glucose metabolism, and resting state-functional MRI (rs-fMRI) to measure brain functional connectivity. We used these methods in both mice with complete GLP-1R knockout (GLP-1R KO) and wild-type C57BL/6N (WT) mice.ResultsThe metabolic rate of GLP-1R KO mice was significantly slower than that of WT mice (p = 0.0345, WT mice 0.02335 ± 0.057 mM/min, GLP-1R KO mice 0.01998 ± 0.07 mM/min). Quantification of the mean [18F]FDG signal in the whole brain also showed significantly reduced glucose uptake in GLP-1R KO mice versus control mice (p = 0.0314). Observing rs-fMRI, the functional brain connectivity in GLP-1R KO mice was significantly lower than that in the WT group (p = 0.0032 for gFCD, p = 0.0002 for whole-brain correlation, p < 0.0001 for ALFF).ConclusionsGLP-1R KO mice exhibit impaired brain glucose metabolism to high doses of exogenous glucose, and they also have reduced functional connectivity. This suggests that the GLP-1R KO mouse model may serve as a model for correlated metabolic and functional connectivity loss.

Metabolic Rate of Goldfish (Carassius auratus) in the Face of Common Aquaculture Challenges.

This study examined the metabolic rate (MO2, oxygen consumption) of goldfish (Carassius auratus) under normal management conditions in aquaculture. Using an intermittent respirometry system, we assessed daily variations and the effects of feeding, handling, temperature increase, and anesthetics. MO2 exhibited a daily rhythm, with higher values during day. Feeding to satiety produced a 35% increase in MO2 compared to fasted animals, with a maximum peak after 3 h and returning to baseline after 7 h. Handling stress (5 min) produced a 140% MO2 peak (from 180 to 252 mg O2 kg-1 h-1), returning to the routine MO2 after 2.5 h. An increase in water temperature (+0.1 °C min-1) up to 30 °C caused MO2 to peak at 200% after 2.5 h from the start of the temperature increase. The use of common anesthetics in aquaculture (MS-222, 2-phenoxyethanol and clove oil in deep anesthesia concentration) affects MO2 during the first few minutes after anesthetic recovery, but also during the following 4 h. It can be concluded that the metabolic rate is a good indicator of the goldfish's response to aquaculture practices involving energy expenditure and stress. Thus, intermittent respirometry is a valuable non-invasive tool for understanding and improving fish welfare in aquaculture.

Microwave Ablation Therapy for Hepatocellular Carcinoma: The Effect of Metabolic Heat on Temperature Distribution

Hepatocellular carcinoma is the main cause of liver cancer and one of the most occurring cancers worldwide. Microwave Ablation (MWA) is a method to destroy cancer cells by heating tumours above 50°C. Cancerous tissues can have high metabolic heat rates and affect temperature gain and distribution in thermal therapies. This research clarifies the metabolic heat effects in MWA therapy of liver cancer. Using Pennes Bioheat transfer equation with finite element numerical method, this research simulates temperature distribution with metabolic heat value ranging from 368,1 W/m3 to 29000 W/m3. The heat generated by metabolic heat is lower than the MWA heat source. However, the temperature increase should be considered as it can increase healthy surrounding tissue temperature to dangerous levels.