Human Body Research Articles

Knowledge enhanced multi-task learning for simultaneous optimization of human parsing and pose estimation

Human parsing and pose estimation are both closely related to the human body structure, and it is advantageous to deal with both together in order to assist each other’s learning. Nevertheless, the two tasks have their own unique characteristics, and it is therefore difficult to efficiently and simultaneously obtain a good performance for both tasks in one single multi-task learning (MTL) network. This paper proposes a new MTL network (named “KDNet”) to enhance the communication between human parsing and pose estimation through knowledge distillation so as to improve the simultaneous learning of both tasks. In the proposed KDNet, a consistent representation module is used to enhance the related information sharing between the tasks, and a single-task model-based loss weighting method is developed to balance the loss levels. The proposed KDNet has been verified across three benchmark datasets, and in comparison to other state-of-the-art methods it achieves substantial performance gains without increasing model parameters during inference. The codes are shared at https://github.com/Yhdian/KDNet.git.

Multi-Organ Foundation Model for Universal Ultrasound Image Segmentation with Task Prompt and Anatomical Prior.

Semantic segmentation of ultrasound (US) images with deep learning has played a crucial role in computer-aided disease screening, diagnosis and prognosis. However, due to the scarcity of US images and small field of view, resulting segmentation models are tailored for a specific single organ and may lack robustness, overlooking correlations among anatomical structures of multiple organs. To address these challenges, we propose the Multi-Organ FOundation (MOFO) model for universal US image segmentation. The MOFO is optimized jointly from multiple organs across various anatomical regions to overcome the data scarcity and explore correlations between multiple organs. The MOFO extracts organ-invariant representations from US images. Simultaneously, the task prompt is employed to refine organ-specific representations for segmentation predictions. Moreover, the anatomical prior is incorporated to enhance the consistency of the anatomical structures. A multi-organ US database, comprising 7039 images from 10 organs across various regions of the human body, has been established to evaluate our model. Results demonstrate that the MOFO outperforms single-organ methods in terms of the Dice coefficient, 95% Hausdorff distance and average symmetric surface distance with statistically sufficient margins. Our experiments in multi-organ universal segmentation for US images serve as a pioneering exploration of improving segmentation performance by leveraging semantic and anatomical relationships within US images of multiple organs.

Interim analysis, a tool to enhance efficiency of pharmacokinetic studies: Pharmacokinetics of rifampicin in lactating mother-infant pairs.

Pharmacokinetic studies are important for understanding drug disposition in the human body. However, pregnant and lactating women are often excluded from primary pharmacokinetic studies and as such there is often limited dosing information regarding drug use in pregnant and/or lactating women. The objectives of this interim analysis were to define the transfer of rifampicin to a breastfed infant and to determine the area under the concentration-time curve of rifampicin in maternal plasma, breastmilk and infant plasma. Performing this interim analysis enabled us to substantiate whether prior assumptions we made on several study design issues including patient sample size and pharmacokinetic sampling times held and whether we needed to amend our protocol or not. We enrolled lactating mothers on treatment for tuberculosis with their breastfeeding infants (below 12 months of age), performed intensive pharmacokinetic sampling (0-24 h post-dose) on plasma samples from both the mother, infant(s) and breastmilk samples from the mother on two separate occasions (once during the initiation phase and another during the continuation phase of tuberculosis treatment). The initial study design, including sampling times, was informed by a stochastic simulation and estimation exercise, with very limited prior breastmilk data. An interim analysis after recruiting 6 mother-infant pairs ascertained that our initial assumptions were ideal for achieving our study objectives and no amendments to the sampling times were necessary. Initial data from 6 mother-infant pairs show that rifampicin penetrates breastmilk with an approximate milk-to-plasma ratio of 0.169 and 0.189 on two separate visits. However, it was undetectable in most infants.

A Multi-Channel Urine Sensing Detection System Based on Creatinine, Uric Acid, and pH

Urine analysis represents a crucial diagnostic technique employed in clinical laboratories. Creatinine and uric acid in urine are essential biomarkers in the human body and are widely utilized in clinical analysis. Research has demonstrated a correlation between the normal physiological concentrations of creatinine and uric acid in urine and an increased risk of hypertension, cardiovascular diseases, and kidney disease. Furthermore, the pH of urine indicates the body’s metabolic processes and homeostatic balance. In this study, an integrated multi−channel electrochemical sensing system was developed, combining electrochemical analysis techniques, microelectronic design, and nanomaterials. The architecture of an intelligent medical detection system and the production of an interactive interface for smartphones were accomplished. Initially, multi−channel selective electrodes were designed for creatinine, uric acid, and pH detection. The detection range was 10 nM to 100 μM for creatinine, 100 μM to 500 μM for uric acid, and 4 to 9 for pH. Furthermore, interference experiments were also conducted to verify the specificity of the sensors. Subsequently, multi−channel double−sided sensing electrodes and function−integrated hardware were designed, with the standard equations of target analytes stored in the system’s read−only memory. Moreover, a WeChat mini−program platform was developed for smartphone interaction, enabling off−body detection and real−time display of target analytes through smartphones. Finally, the aforementioned electrochemical detection electrodes were integrated with the smart sensing system and wirelessly interfaced with smartphones, allowing for intelligent real−time detection in primary healthcare and individual household settings.

The human body in different spaces

Space Medicine has revolutionized the way of understanding human physiology in extra-terrestrial environments, such as microgravity. Research in this field attempts to maintain synchrony between scientific and medical development, with the goal of improving the overall health and performance of astronauts. Engineering also plays a crucial role in the design of spacecraft and spacesuits to ensure the safety and health of astronauts on extended missions to the Moon and Mars. Radiation exposure in space poses health concerns, but strategies such as radiation control and shielding are being implemented to mitigate these risks. NASA is actively investigating how the human body reacts to long-duration spaceflight, with the goal of preparing for future extended space missions.

Подбор параметров экстракции биоактивных веществ из лекарственных растений с применением молочной сыворотки

Due to its natural chemical composition, whey can have both a positive effect on the human body and cause significant harm to the environment. It is rich in organic substances, which creates an additional organic burden on nature. However, whey has good prospects for the food industry as an extractant for the production of plant extracts and biologically active substances. The present research objective was to select optimal parameters for obtaining flavonoids from plant extracts using an unconventional type of extractant, i.e., whey. The study featured whey as an extractant and mixes of medicinal herbs. The resulting extracts were tested for the content of flavonoid compounds by thin-layer chromatography. The antioxidant activity was assessed using the spectrophotometric method. The extraction variables included temperature, extraction time, material-to-extractant ratio, and composition of herbal mixes. The extraction time ranged from 1 to 5 h at 90 ± 1℃. The maximal antioxidant activity belonged to the samples containing 7.5–12.5 g herbal mix and 450 ml whey. The optimal extraction time was 3 h. The content of flavonoids in the plant extracts was comparable and did not depend on the extraction time. Extraction time proved to be the key parameter to intensify the process of flavonoid extraction from plant raw materials. Therefore, the choice was made according to the shortest time with comparable values of flavonoids and the maximal level of antioxidant activity.

Ultrahighly Sensitive Flexible Pressure Sensors with Dual-Mode Response Based on Monolayer Films of Calcium Niobate Nanosheets.

Flexible pressure sensors present enormous potential for applications in health monitoring, human-machine interfacing, and electronic skins (e-skin). However, at the cost of flexibility, the design of flexible pressure sensors has been facing the trade off between high sensitivity and wide sensing range. Herein, we propose a sandwiched structure composed of monolayer films of calcium niobate nanosheets to endow the device with both ultrahigh sensitivity and a wide sensing range. Tunable contact between the two electrodes of the pressure sensor through the gaps in the insulative monolayer film and precise thickness modulation of the monolayer films at the nanoscale result in an ultrahigh sensitivity and wide sensing range of the sensors. By virtue of these two traits, the pressure sensor distinguishes itself with unprecedented performances of ultrahigh sensitivity (6.43 × 104 kPa-1), a wide sensing range (1.94-60.00 kPa), a fast response time (<165 ms), and reliable repeatability. In addition, the sensor has a sensing mechanism transition from capacitive mode to piezoresistive mode from low pressure to high pressure. The sensors demonstrates the ability for motion detection of the human body. This work sheds light on the development of highly sensitive flexible pressure sensors.

High-resolution mid-infrared image transport by a chalcogenide multi-core fiber

Abstract We have successfully demonstrated high-resolution mid-infrared image transport by a multi-core fiber made of chalcogenide glasses.&amp;#xD;The fiber cores are arranged on a triangular lattice, and adjacent cores have different core diameters to reduce cross-talk between them.&amp;#xD;We tested the resolution of the fiber using different fineness patterns and found that it can resolve better than 25 lp/mm at a wavelength of 9.3 μm.&amp;#xD;This demonstrates the potential of the fiber for high-resolution thermal imaging inside the human body.

Discrimination Ability and Concentration Measurement Accuracy of Effective Components in Aroma Essential Oils Using Gas Sensor Arrays with Machine Learning

Aroma essential oils contain ingredients that are beneficial to the human body. A gas sensor array is required to monitor the concentration of these essential oil components to regulate their concentration by air conditioning systems. Therefore, we investigated the discrimination ability and concentration measurement accuracy of 14 effective components, including four aroma essential oils (lavender, melissa, tea tree, and eucalyptus), from a single gas sample and mixtures of two gases using sensor arrays. To obtain our data, we used two sensor arrays comprising commercially available semiconductor sensors and our developed semiconductor sensors. For machine learning, principal component analysis was used to visualize the dataset obtained from the sensor signals, and an artificial neural network was used for a detailed analysis. Our developed sensor array, which included sensors that possessed excellent sensor responses to 14 effective components and combined different semiconductive sensor principles, showed a better discrimination and prediction accuracy than the commercially available sensors investigated in this study.

Application of questionnaires in studying the frequency of multiple chemical sensitivity syndrome

BACKGROUND: Multiple chemical sensitivity syndrome is a set of adverse physiological reactions of the human body to exposure to common chemical agents in low doses, which are considered non-toxic to the population. AIM: To study the frequency and characteristics of multiple chemical sensitivity syndrome manifestation using the Russified questionnaire Quick Environment Exposure and Sensitivity Inventory (QEESI). MATERIAL AND METHODS: In the pilot study, 468 people undergoing a preventive medical examination were surveyed (232 men, average age 34.2±9.3 years, and 236 women, average age 42.9±13.8 years). To assess multiple chemical sensitivity, an analysis of three subscales of the Russified validated QEESI questionnaire (chemical intolerance, severity of symptoms, and impact on everyday life) was used. The statistical significance of differences in relative indicators was assessed using the Pearson χ2 criterion. Absolute indicators were presented as M (SD). Relationships and differences in indicators were considered statistically significant at p 0.05. RESULTS: The frequency of multiple chemical sensitivity syndrome was 45.5%, 51.7% of patients had concomitant diseases. The frequency of comorbidities with and without multiple chemical sensitivity syndrome was comparable: allergic diseases — 25.6 vs 17.5%, χ2=3.84, p=0.069; irritable bowel syndrome — 8.1 vs 10.9%, χ2=3.648, p=0.057; migraine — 11 vs 10.5%, χ2=0.642, p=0.424. Multiple chemical sensitivity syndrome was more often detected in women (74.3 vs 25.6%, χ2=5.76, p=0.001) and patients with a sedentary lifestyle (58.3 vs 24.8% χ2=11.9; p=0.01). In patients with multiple chemical sensitivity syndrome, the most common central nervous system complaints were mood lability (26.5 vs 11.3%, χ2=18.936, p=0.003), headaches (27.4 vs 10.5%, χ2=7.555, p=0.006); in the gastrointestinal tract — nausea (13.7 vs 7.6%, χ2=4.826, p=0.029), abdominal pain (10.9 vs 5.5%, χ2=4.178, p=0.041). CONCLUSION: A high frequency of multiple chemical sensitivity syndrome (45.5%) was revealed, which was typical for women and patients with a sedentary lifestyle. Patients with this syndrome significantly more often reported complaints from the central nervous system and gastrointestinal tract.

B-158 Association between multiple heavy metals exposure and blood lipid levels: evidence from a cross-sectional study of Korean adults

Abstract Background Metals are ubiquitous in our environment and enter human body via various pathways, such as air, soil, food, water, etc. Increasing studies have found that metals are important risk factors in developing dyslipidemia. However, there is no consensus regarding the effects of co-exposure to multiple metals on blood lipid levels. We investigated both the joint and individual effects of this metal mixture exposure on human blood lipid levels. Methods Blood concentrations of four human toxic metals (Pb, Cs, Hg, and Cd) in 2,798 general populations from Korea were simultaneously determined as a measure of exposure. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to estimate associations of four blood metals and metals mixture with lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). Results The mean age of the overall study population was 41.2 ± 9.85 years, and 66.9% were men. The prevalence of overweight or obesity, diabetes, and hypertension in the population was 62.5, 6.8, and 13.9%, respectively. In the multivariable linear regression model, the blood Cs was positively associated with TC and LDL-C(p &amp;lt; 0.05, all), and the blood Pb was positively associated with serum TG (p &amp;lt; 0.05, all). Also, the blood Cd was positively associated with serum HDL-C (p &amp;lt; 0.05, all). We did not identify any other obvious interaction between metals on the lipid profiles using a bivariate exposure-response function in BKMR. Conclusions Our finding suggests that combined exposure to this metal mixture may affect human blood lipid levels. Therefore, reducing exposure to heavy metals, such as Cs and Pb, should be a priority for the general population. However, future studies with a larger number of heavy metals are still needed to focus on the detrimental effects of single metals on lipid profiles as well as to identify key components.

Reversibly Compressible Silanated Cellulose Nanofibril Aerogel for Triboelectric Taekwondo Scoring Sensors.

The integration of bio-based materials into triboelectric nanogenerators (TENGs) for energy harvesting from human body motions has sparked considerable research attention. Here, a silanated cellulose nanofibril (SCNF) aerogel is reported for structurally reliable TENGs and reversely compressible Taekwondo scoring sensors under repeated impacts. The preparation of the aerogel involves silanizing cellulose nanofibers (CNFs) with vinyltrimethoxysilane (VTMS), following by freeze-drying and post-heating treatment. The SCNF aerogel with crosslinked physico-chemical bonding and highly porous network is found to exhibit superior mechanical strength and reversible compressibility as well as enhanced water repellency and electron-donating ability. The TENG having a tribo-positive SCNF layer exhibits exceptional triboelectric performances, generating a voltage of 270V, current of 11µA, and power density of 401.1mWm-2 under an applied force of 8N at a frequency of 5Hz. With its inherent merits in material composition, structural configuration, and device sensitivity, the SCNF TENG demonstrates the capability to seamlessly integrate into a Taekwondo protection gear, serving as an efficient self-powered sensor for monitoring hitting scores. This study highlights the significant potential of a facilely fabricated SCNF aerogel for the development of high-performance, bio-friendly, and cost-effective Bio-TENGs, enabling their application as self-powered wearable devices and sports engineering sensors.

Investigation of The Stability of The Lysozyme in Magnetic Particles for Drug Delivery

This research investigated lysozyme stability in the presence of magnetic particles for drug delivery. Lysozyme can mostly be found in the hen egg albumin, and it also acts as an essential agent, which is antibodies to fight harmful bacteria or shield the human body. The problems in this research are magnetic particles that can cause toxicity and reduce the therapy's efficiency due to the degradation of carriers (drugs). To minimise this problem, the stability and activity of the lysozyme and Fe2O3 were investigated. The structure of lysozyme and Fe2O3 before and after adding acid or alkaline was defined, and the suitability of Fe2O3 as a drug delivery was determined. The stability of the lysozyme and Fe2O3was identified using an Ultraviolet-Visible (UV-Vis) Spectrophotometer, and the structure was investigated using a Field Emission Scanning Electron Microscope (FESEM) and Scanning Electron Microscope- Energy Dispersive X-Ray (SEM-EDX). Different concentrations become the parameters of this research as a comparison between the samples. This research found that the combination of the lysozyme alkaline material was suitable for the body at a pH of 12.2. It also found that Fe2O3 is ideal for drug delivery in the body when the lysozyme can be carried by Fe2O3 and dissolved in the Fe2O3.

Body heat energy driven knitted thermoelectric garments with personal cooling

Wearable, thermoelectric (TE) devices have gained significant interest in recent years as they can both generate output power from converting body heat into electrical energy and be utilized in personal cooling through the Peltier effect. Currently, researched wearable TE cooling devices focus on devices that can be attached to the human body in specific locations and use heat sinks or elongated thermoelectric pillars to increase their effectiveness, making them hard and bulky. In addition, these devices are attached, not integrated, to wearable garments, making their manufacturing a multi-step process. To address this issue, we developed a knitted TE garment through a single-step manufacturing process that offers energy generation and personal cooling capabilities. The functioning of the cooling device was mathematically modelled and analyzed to understand its scalability, optimization, and to show its potential. This garment features excellent thermoelectric generation of 7.48 mV and 0.46 mA on the human body, and the ability to cool the human body up to 1.5 °C. The observations proved that the mathematical model could predict the behavior of the TE device closely. The results showed that the proposed method of knitted TE cooling garment manufacturing is a viable and scalable process.

Long-term exposure of human U87 glioblastoma cells to polyethylene microplastics: Investigating the potential cancer progression

Precancerous cells are present in all human bodies. Various environmental triggers can promote the development of cancer. Microplastics, an emerging concern, may potentially act as one such trigger, contributing to cancer initiation or progression. Studies have confirmed the presence of microplastics within the human body. This raises concerns about their potential toxicity and health risks. In the present study, we aimed to investigate the impact of polyethylene microplastics (PE-MPs) within the size range of 37–75 microns on glioblastoma cancer cells. Initially, we assessed the short-term effects of six different concentrations of PE-MPs (20 mg/mL, 10 mg/mL, 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, and 0.62 mg/mL) on the U87 glioblastoma cell line. The results demonstrated that PE-MPs exposure led to an increase in cell proliferation compared to the untreated control group. Based on these findings, we decided to further explore the long-term effects of PE-MPs on U87 cancer cells. To evaluate the long-term effects, U87 glioblastoma cells were continuously exposed to 0.005 g of PE-MPs over an extended period of 26 days. Chronic exposure to PE-MPs significantly increased the proliferative and migratory capacities of U87 cells compared to the unexposed control group. Furthermore, continuous PE-MPs exposure altered the behavior and morphological characteristics of U87 cells. These cells exhibited a propensity to aggregate and form colonies within the culture flask. The formation of spheroid structures was also observed in the PE-MPs-exposed cell population. The results of this research indicate that polyethylene microplastics can promote the progression of glioblastoma cancer.

The versatile multi-functional substance NMN: its unique characteristics, metabolic properties, pharmacodynamic effects, clinical trials, and diverse applications

β-nicotinamide mononucleotide (NMN) is a naturally occurring biologically active nucleotide widely present in organisms and an inherent substance in the human body. As a critical intermediate in synthesizing coenzyme I (NAD+), it widely participates in multiple biochemical reactions in the human body and is closely related to immunity, metabolism, and other factors. In recent years, NMN has rapidly developed and made significant progress in medicine, food, and healthcare. However, there is currently a lack of comprehensive reports on the research progress of NMN, as well as exploration and analysis of the current research achievements and progress of NMN. Therefore, this review is based on retrieving relevant research on NMN from multiple databases at home and abroad, with the retrieval time from database establishment to 20 May 2024. Subsequently, literature search, reading, key information extraction, organization, and summarization were conducted with the aim of providing a comprehensive and in-depth analysis of the characteristics, metabolic pathways, pharmacological effects, progress in human clinical trials, and wide applications of NMN in drug development and food applications. Furthermore, it offers personal insights into NMN’s potential future developments and advancements to present the current development state and existing challenges comprehensively. Ultimately, this review aims to provide guidance and serve as a reference for the future application, innovation, and progression of NMN research.

Fabrication of PEI/CF composite parts with multi-angle reinforced mechanical properties by a micro-extrusion foaming FDM process

The combination of fused deposition modeling (FDM) and foaming technology enables the fabrication of complex hierarchical and lightweight parts. However, this approach is hindered by a reduction in the mechanical properties of final parts. To this end, with the aim of addressing the challenge of the fabrication of 3D-printed parts with enhanced mechanical and lightweight features, a micro-extrusion foaming FDM process using CO2 as a blowing agent was hereby established, and the carbon fiber (CF) was selected as a reinforcing filler. Compared to pure polyetherimide (PEI) parts, the longitudinal tensile strength of the PEI/CF parts with 5.0 wt% CF added increased by 30.3 %, while the interfacial bonding strength of PEI/CF-5.0 foamed parts increased by 86.3 % compared to the unfoamed parts. Furthermore, the PEI/CF-5.0 foamed parts, weighing only about 1.7 g, could bear a load of a 60 kg human body in multiple directions. Additionally, focusing on the filler orientation and the enhanced interdiffusion and entanglement of polymer chains at interfaces, the reinforcement mechanisms of the foamed parts fabricated by micro-extrusion foaming FDM process were discussed. The micro-extrusion foaming FDM process demonstrated the capability to produce lightweight parts with enhanced mechanical properties, making it a promising technology for applications in the aerospace and military industries.

Eukaryotic cell size regulation and its implications for cellular function and dysfunction.

Depending on cell type, environmental inputs, and disease, the cells in the human body can have widely different sizes. In recent years, it has become clear that cell size is a major regulator of cell function. However, we are only beginning to understand how the optimization of cell function determines a given cell's optimal size. Here, we review currently known size control strategies of eukaryotic cells and the intricate link of cell size to intracellular biomolecular scaling, organelle homeostasis, and cell cycle progression. We detail the cell size-dependent regulation of early development and the impact of cell size on cell differentiation. Given the importance of cell size for normal cellular physiology, cell size control must account for changing environmental conditions. We describe how cells sense environmental stimuli, such as nutrient availability, and accordingly adapt their size by regulating cell growth and cell cycle progression. Moreover, we discuss the correlation of pathological states with misregulation of cell size and how for a long time this was considered a downstream consequence of cellular dysfunction. We review newer studies that reveal a reversed causality, with misregulated cell size leading to pathophysiological phenotypes such as senescence and aging. In summary, we highlight the important roles of cell size in cellular function and dysfunction, which could have major implications for both diagnostics and treatment in the clinic.

Protocol to evaluate human thermoregulation before and after thermal stress

Problem and MotivationThe human body dissipates 60% of its heat by emitting infrared radiation, it can be studied using Infrared Thermography (IRT). IRT images serve as thermal maps of the body, useful in medical applications to investigate the physiopathological of diseases that present symptoms such as swelling, pain, infection, rash, and increased local skin temperature. AimTo design a protocol to capture IRT images before and after physical activity. The protocol collects skin temperature data of the entire body, in the frontal (anterior and posterior) and sagittal (right and left) planes. MethodologyThe protocol was designed considering clinical, environmental, and technical factors and ensuring its reproducibility in both healthy and pathological populations. Thermographic images were acquired both at rest and after thermal stress (modified Bruce test). In addition, questionnaires were prepared to collect and store information on demographic data, core temperature, environmental conditions, pain perception, and level of physical activity. ResultsThe protocol combines the acquisition of IRT images with the application of the modified Bruce protocol on a treadmill as a thermal stress generator. Further impactThis protocol offers a valuable tool for studying the thermoregulatory capacity of the human body in the presence of different medical conditions.

Heat Stress Metrics, Trends, and Extremes in the Southeastern United States

Abstract Humid heat and associated heat stress have increased in frequency, intensity, and duration across the globe, particularly at lower latitudes. One of the more robust metrics for heat stress impacts on the human body is wet-bulb globe temperature (WBGT), because it incorporates temperature, humidity, wind speed, and solar radiation. WBGT can typically only be measured using nonstandard instrumentation (e.g., black globe thermometers). However, estimation formulas have been developed to calculate WBGT using standard surface meteorological variables. This study evaluates several WBGT estimation formulas for the southeastern United States using North Carolina Environment and Climate Observing Network (ECONet) and U.S. Military measurement campaign data as verification. The estimation algorithm with the smallest mean absolute error was subsequently chosen to evaluate summer WBGT trends and extremes at 39 ASOS stations with long continuous (1950–2023) data records. Trend results showed that summer WBGT has increased throughout much of the southeastern United States, with larger increases at night than during the day. Although there were some surprisingly large WBGT trends at higher elevation locations far from coastlines, the greatest increases were predominantly located in the Florida Peninsula and Louisiana. Increases in the intensity and frequency of extreme (90th percentile) WBGTs were particularly stark in large coastal urban centers (e.g., New Orleans, Tampa, and Miami). Some locations like New Orleans and Tampa have experienced more than two additional extreme heat stress days and nights per decade since 1950, with an exponential escalation in the number of extreme summer nights during the most recent decade. Significance Statement Humid heat and associated heat stress pose threats to health in the moist subtropical climate of the southeastern United States. Wet-bulb globe temperature (WBGT) is a robust metric for heat stress but must be estimated using complex algorithms. We first evaluated the accuracy of three WBGT algorithms in the southeastern United States, using measured verification data. Subsequently, we used the most accurate algorithm to investigate WBGT trends and extremes since 1950 in 39 cities. Results showed that summer heat stress has increased throughout the region, especially at night. Increases in the intensity and frequency of extreme heat stress were most prevalent at urban coastal locations in Florida and Louisiana, emphasizing the impacts of increased urbanization and evaporation on heat stress.