Conductance Responses Research Articles

Silver Nanoparticle-Decorated Cellulose Nanocrystal Reinforced Ionic Polymer Hydrogel With High Conductivity and Environmental Tolerance for Multifunctional Sensing and Emergency Alarm System.

Conductive hydrogels hold great promise for flexible electronics. However, the simultaneous achievement of satisfactory mechanical strength, outstanding environmental tolerance, high sensitivity, and multiple sensing applications in a single conductive hydrogel remains a significant challenge. Herein, ionic polymer-based hydrogels with a double conductive network consisting of [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (DMC), 2-hydroxyethyl acrylate (HEA) and silver nanoparticle decorated cellulose nanocrystal (CNC@Ag) are prepared by a facile one-pot method. The resultant hydrogel (CDH) exhibits high stretchability, satisfactory self-adhesion, excellent environment tolerance (from -60 to 60°C), long-term stability (60 days), effective UV-shielding, and strong antibacterial properties. Significantly, the CDH hydrogel displays high conductivity and rapid response due to its double conductive network of ionic polymer and CNC@Ag. Therefore, the CDH-assembled sensor can accurately detect signals from both strain and pressure deformations, exhibiting outstanding sensitivity and reliability for human motion detection, signal transmission, object recognition, and tactile sensing. More interestingly, collaborating with a development board, the CDH-based sensor can be developed as an emergency alarm to realize prompt alarms in dangerous situations. Overall, this work presents a strategy for the fabrication of conductive hydrogel with remarkable properties, making it possible for multifunctional sensing applications in wearable electronics.

Decisions to seek cognitive performance feedback: Potential determinants of feedback value and consequences for learning

Performance feedback is essential for effective learning. Feedback contains both informational and affective properties. Following negative feedback (indicating an incorrect response), the unpleasant experience of being wrong can diminish the value of constructive information that feedback also provides. This can hinder motivation to seek feedback, which can impede learning. Therefore, research into factors that directly shape the subjective value of feedback is critical. The current study investigated potential behavioral and physiological contributors to feedback valuation and to subsequent feedback-seeking behavior. Fifty-nine participants completed a willingness-to-pay associative memory task that measured feedback valuation via trial-wise decisions to either purchase or forgo feedback during a learning phase in service of maximizing a performance-contingent monetary reward during a future test phase. Skin conductance response (SCR) was also measured during feedback decisions. Lower confidence in response accuracy significantly predicted higher likelihood of purchasing feedback during learning. Neither self-reported emotional responses to feedback nor SCR during feedback decisions predicted feedback purchases. Purchase decisions yielding negative feedback significantly predicted better performance during test. These results suggest that confidence during learning significantly impacts performance feedback valuation and should be considered when devising methods to motivate feedback-seeking in settings where learning is critical to success.

Skin conductance response and habituation to emotional facial expressions and words.

Skin conductance response (SCR) serves as a dependable marker of sympathetic activation used to measure emotional arousal. This study investigates the impact of presentation modality (face or word) on the degree of emotional discrimination elicited by SCR. Facial expressions or words associated with six basic emotions-anger, happiness, disgust, fear, sadness, and surprise-were studied among 102 participants. The amplitude of SCR was accurately predicted by subjective arousal ratings of these stimuli, but not by valence ratings. The habituation process to emotional and neutral stimuli across six successive presentations was characterized by an exponential decay function, capturing the rate at which SCR response diminishes in relation to the preceding trial of the same stimulus. Through the subtraction of the response to neutral stimuli from the emotion-evoked SCR, it was demonstrated that the initial presentation of each emotion elicits a substantial response, particularly attributable to the emotional content. Notably, the initial emotional response to faces expressing happiness, disgust, and sadness surpassed that of words conveying the same emotions. The results indicate that different emotional responses can be quantified using a simple electrical instrument.

Persistent defensive reactivity during extensive avoidance training as a potential mechanism for the perpetuation of safety behaviors.

Safety behaviors are core features of anxiety-related disorders, specifically involving behaviors that do not completely terminate aversive situations, but rather prevent the risk of the occurrence of the expected aversive outcome (US). This study aimed to examine the dynamics of defensive reactivity associated with safety behaviors, both before and after their execution, and to investigate changes in these reactions following extensive training. Twenty-four healthy participants underwent a US-avoidance task as an experimental analog to model safety behavior, requiring a button press to avoid the US without terminating the associated warning cue (CS). Two CS+ were used, with one being devalued during a devaluation procedure to assess the formation of avoidance habits. Defensive reactivity was assessed using fear-potentiated startle (FPS) and skin conductance responses (SCR). Participants showed pronounced defensive reactivity to both CS + vs. CS- before the avoidance action, which decreased upon the opportunity to avoid the US. Contrarily, after the avoidance action, a re-emergence of defensive responses was observed as indicated by FPS and increased SCR. Only one participant showed signs of avoidance habit formation. The findings reveal a re-emergence of defensive reactivity following safety behaviors challenging the prevailing belief that relief is the primary sustaining factor of safety behavior.

Biochar affects soil properties over 1 m depth in an alkaline soil of north China Plain

Biochar has been shown to enhance soil quality and agricultural yields. Previous studies about biochar's effect on soil properties mainly concentrated on the top 30 cm layer but less on the subsoils. Given the subsoil's active role in climate change mitigation and its significance for nutrient cycling and crop productivity, understanding biochar's effects at depth is crucial. This study explored the responses of soil organic carbon (SOC), total nitrogen, available potassium, available phosphorus, pH, and electrical conductivity to different doses of biochar addition (0, 10, 20, and 30 Mg/ha) over the 1 m depth of alkaline soil. Additionally, the impact of biochar on soil microbial community was assessed in the top 20 cm. Results demonstrated that biochar addition can increase SOC and improve soil properties in deep soil horizons. Specifically, a 30 Mg/ha biochar addition increased SOC by 1.2–10.1 Mg C/ha in the 10–40 cm layer and by 3 Mg C/ha in the 60–80 cm depth over two years. Additionally, biochar addition at this rate increased total nitrogen by 0.2–0.3 g N/kg in the 10–40 cm depth and elevated available potassium across the 1 m profile, with a maximum increment of 313 mg/kg in the surface 10 cm and a minimum of 97 mg/kg in the 40–60 cm depth. While biochar application did not increase available phosphorus, it resulted in a minor decrease in soil pH (<0.7 units) and a slight increase in electrical conductivity. Moreover, biochar addition did not significantly alter the soil microbial community. Our findings underscore the importance of considering subsoils when evaluating biochar's impact on soil properties. We suggest that subsoils should be considered when estimating the potential of cropland management for increasing soil carbon sequestration and improving soil conditions.

Effects of separate and combined estradiol and progesterone administration on fear extinction in healthy pre-menopausal women

Altered fear conditioning and extinction learning are discussed as key etiological features in anxiety disorders. Women have an increased risk for anxiety disorders and fear conditioning has been shown to be influenced by the menstrual cycle phase and circulating gonadal hormones. The objective of our study was to investigate the effects of separate and combined estradiol and progesterone administration on fear extinction in healthy women. We conducted a placebo-controlled, randomized study in healthy women, who completed a fear conditioning paradigm on three consecutive days: fear acquisition training on day 1, fear extinction training on day 2, and return of fear test on day 3. Skin conductance responses (SCRs) served as main outcome variable. Two hours before testing on day 2, participants received pills containing either placebo, estradiol (2 mg), progesterone (400 mg) or the combination of both. We examined 116 women (mean age 25.7 ± 6.0 years), who showed significantly stronger conditioned SCRs to the CS+ than CS- during fear acquisition training indicating successful fear learning. At the beginning of the fear extinction training, estradiol administration reduced the differentiation between the conditioned stimuli. In the return of fear test, the estradiol groups showed heightened SCR responses to the previously extinguished stimulus, i.e., impaired extinction recall. Administration of progesterone did not have any significant influence on SCRs. There were also no effects on fear potentiated startle response. In our interpretation, exogenous estradiol administration affected the extinction of the conditioned fear response which led subsequently to a stronger return of fear. From a clinical perspective our findings suggest that estradiol levels may have an influence on the success of exposure therapy and could be taken into consideration when planning exposure sessions.

Self‐Powered Wearable Pressure Sensors for Detection and Separation of Signals for Various Human Movements

A detailed study on the dynamic response of mountable pressure sensors is presented, with a focus on foot pressure sensors integrated with carbon nanotube (CNT)‐coated cotton fibers. The research explores the sensor's sensitivity to pressure changes, repeatability, hysteresis, and durability through rigorous modeling and experimental validation. Computational simulations using Python and experimental data demonstrate the sensor's nonlinear conductance response to applied force, attributed to the varying contact area and number of contact points among the fibers. Long‐term outdoor exposure tests confirm the material's resilience, maintaining electrical conductivity and structural integrity. The study also demonstrates the sensor's ability to monitor human activities like walking, running, stair climbing, and jumping, as well as detecting muscle movements during swallowing, coughing, and speech, highlighting potential applications in health monitoring and artificial voice synthesis. The MRMR algorithm is used for feature selection to distinguish activities, demonstrating the sensor's potential for activity recognition. Additionally, a piezoelectric sensor on the pressure sensors estimates harvested electric power to power wearable devices. This work contributes to the advancement of self‐powered wearable pressure sensors to monitor real‐time human activity, with implications for healthcare, sports performance, and assistive technologies.

Quantification and Interpretation of Nitric Oxide-Dependent Cutaneous Vasodilation During Local Heating.

Human cutaneous microdialysis approaches for assessing nitric oxide (NO)-dependent blood flow include local heating (LH) of the skin until a plateau is reached, followed by infusion of a NO synthase inhibitor such as L-NAME; however, varied methods of quantifying and expressing NO-dependent vasodilation can obfuscate data interpretation and reproducibility. We retrospectively assessed NO-dependent vasodilation during LH to 39°C or 42°C, calculated as the: (1) absolute contribution of the NO-dependent component (along with baseline and the non-NO-dependent component) to the total cutaneous vascular conductance (CVC) response to LH, normalized to maximal CVC (%CVCmax); (2) difference in %CVCmax (∆%CVCmax) between the LH plateau and post-NO inhibition (L-NAME plateau; ∆%CVCmax=LH plateau-L-NAME plateau); (3) percentage of the LH plateau attributable to ∆%CVCmax (%Plateau = ∆%CVCmax/LH plateau*100); and (4) %Plateau when correcting for baseline. The LH plateaus during 39°C and 42°C were 48±17 %CVCmax (9±5% baseline; 2±4% non-NO-dependent; 36±15% NO-dependent) and 88±10 %CVCmax (15±8% baseline; 9±10% non-NO-dependent; 64±13% NO-dependent), respectively. The absolute contributions of the non-NO-dependent and NO-dependent components of the response (p<0.0001) and the ∆%CVCmax (66±14% vs. 38±15%) were greater during 42°C compared with 39°C (all p≤0.02); however, there were no differences between the two protocols in %Plateau (75±13% vs. 80±10%; p=0.57) or %PlateauBL (88±14% vs. 95±8%; p=0.31). For both protocols, the values were greater for %PlateauBL versus ∆%CVCmax and %Plateau (p≤0.0001), and for %Plateau versus ∆%CVCmax (p≤0.05). Quantification of NO-dependent skin vasodilation responses to LH is dependent upon the mathematical approach and verbal description, which can meaningfully impact data interpretation and reproducibility.

Balancing stretchability and conductivity: Carbon nanotube layer-enhanced non-ionic conductive hydrogels with a sandwich structure

In non-ionic conductive hydrogels, conductivity often conflicts with mechanical properties, posing a challenge in creating hydrogels that strike a balance between conductivity and mechanical properties. Here, we addressed this issue by integrating carboxylated carbon nanotube (CNT) layers in a sandwich structure onto the surface of the cationic hydrogel (P(AM-co-DMDAAC), PAD), followed by dehydration for densification. This approach simultaneously improved the conductivity of the hydrogel while maintaining its stretchability. The stability of the composite structure was ensured through electrostatic interactions, hydrogen bonding, and physical entanglement between the PAD hydrogel and the CNT layer. Additionally, adjusting the water–solid ratio of the hydrogel allows fine-tuning of its conductivity and stretchability. Remarkably, at a 500 % water–solid ratio, the hydrogel achieved a conductivity of 2.3 S/m. By further reducing the water content, the conductivity could be increased to 25 S/m, significantly higher than similar hydrogels. The PAD-CNT hydrogel found applications in swelling response, tunable resistance wires, and as strain sensors. Notably, the sandwich structure enables the PAD-CNT hydrogel to output capacitive signals, exhibiting a more sensitive response in monitoring human movement. Overall, this study introduces a novel composite structure for conductive hydrogels, holding tremendous potential in flexible conductivity and smart response fields.

EzySCR: A free and easy tool for scoring event-related skin conductance responses in the first, second, and third interval latency windows.

Skin conductance is a commonly used physiological measure during psychology experiments, such as during fear conditioning. Methods for scoring skin conductance responses (SCRs) are highly heterogeneous, though most researchers agree that manually inspected scores provide the highest quality data when compared to most available fully automated scoring methods. However, manual scoring is extremely time-consuming. We developed a semi-automated scoring program that reduces the time required to process SCR data at a level of quality akin to manual scoring. In contrast to all previous scoring programs, our program enables scoring of first interval response (FIR), second interval response (SIR), and third interval response (TIR) SCRs. Using interclass correlation coefficients (ICCs), Bland-Altman plots and Pareto analysis, we show here that our method is highly reliable and produces data that are almost identical to data that are manually scored and scored using LEDALAB. This software is very easy to use and is freely available to download and modify. We expect that this software will be helpful in reducing the time required to produce high quality FIR, SIR, and TIR skin conductance data for psychology researchers around the world.

Insulator-to-Metal Transition and Isotropic Gigantic Magnetoresistance in Layered Magnetic Semiconductors.

Magnetotransport, the response of electrical conduction to external magnetic field, acts as an important tool to reveal fundamental concepts behind exotic phenomena and plays a key role in enabling spintronic applications. Magnetotransport is generally sensitive to magnetic field orientations. In contrast, efficient and isotropic modulation of electronic transport, which is useful in technology applications such as omnidirectional sensing, is rarely seen, especially for pristine crystals. Here a strategy is proposed to realize extremely strong modulation of electron conduction by magnetic field which is independent of field direction. GdPS, a layered antiferromagnetic semiconductor with resistivity anisotropies, supports a field-driven insulator-to-metal transition with a paradoxically isotropic gigantic negative magnetoresistance insensitive to magnetic field orientations. This isotropic magnetoresistance originates from the combined effects of a near-zero spin-orbit coupling of Gd3+-based half-filling f-electron system and the strong on-site f-d exchange coupling in Gd atoms. These results not only providea novel material system with extraordinary magnetotransport that offers a missing block for antiferromagnet-based ultrafast and efficient spintronic devices, but also demonstrate the key ingredients for designing magnetic materials with desired transport properties for advanced functionalities.

Memory detection with concurrent behavioral, autonomic, and neuroimaging measures in a mock crime.

Concealed information test (CIT) has been utilized for long to perform single measurements. The combination of multiple measures outperforms single measures because of the diverse cognitive processes they reflect and the reduction in random errors facilitated by multiple measures. To further explore the performance of the CIT with multiple measurements, 57 participants were recruited and randomly assigned into guilty and innocent groups. Subsequently, simultaneously recorded reaction time (RT), skin conductance responses (SCRs), heart rate (HR), and neuroimaging data were collected from functional near-infrared spectroscopy (fNIRS) to detect participants' concealed information in a standard CIT. The results demonstrated that all indicators including RT (area under the curve (AUC) = 0.87), SCRs (AUC = 0.79), HR (AUC = 0.78), and fNIRS (channel 8, AUC = 0.85) could differentiate guilty and innocent groups. Importantly, the use of multiple indicators achieved higher detection efficiency (AUC = 0.96) compared to the use of any single indicator. These results illustrate the effectiveness and feasibility of integrating multiple indicators for concealed information detection in CIT.

Reverse-engineered models reveal differential membrane properties of autonomic and cutaneous unmyelinated fibers.

Unmyelinated C-fibers constitute the vast majority of axons in peripheral nerves and play key roles in homeostasis and signaling pain. However, little is known about their ion channel expression, which controls their firing properties. Also, because of their small diameters (~ 1 μm), it has not been possible to characterize their membrane properties using voltage clamp. We developed a novel library of isoform-specific ion channel models to serve as the basis functions of our C-fiber models. We then developed a particle swarm optimization (PSO) framework that used the isoform-specific ion channel models to reverse engineer C-fiber membrane properties from measured autonomic and cutaneous C-fiber conduction responses. Our C-fiber models reproduced experimental conduction velocity, chronaxie, action potential duration, intracellular threshold, and paired pulse recovery cycle. The models also matched experimental activity-dependent slowing, a property not included in model optimization. We found that simple conduction responses, characterizing the action potential, were controlled by similar membrane properties in both the autonomic and cutaneous C-fiber models, but complicated conduction response, characterizing the afterpotenials, were controlled by differential membrane properties. The unmyelinated C-fiber models constitute important tools to study autonomic signaling, assess the mechanisms of pain, and design bioelectronic devices. Additionally, the novel reverse engineering approach can be applied to generate models of other neurons where voltage clamp data are not available.

Effects of Salicylic Acid on Physiological Responses of Pepper Plants Pre-Subjected to Drought under Rehydration Conditions.

Capsicum annuum L. has worldwide distribution, but drought has limited its production. There is a lack of research to better understand how this species copes with drought stress, whether it is reversible, and the effects of mitigating agents such as salicylic acid (SA). Therefore, this study aimed to understand the mechanisms of action of SA and rehydration on the physiology of pepper plants grown under drought conditions. The factorial scheme adopted was 3 × 4, with three water regimes (irrigation, drought, and rehydration) and four SA concentrations, namely: 0 (control), 0.5, 1, and 1.5 mM. This study evaluated leaf water percentage, water potential of shoots, chlorophylls (a and b), carotenoids, stomatal conductance, chlorophyll a fluorescence, and hydrogen peroxide (H2O2) concentration at different times of day, water conditions (irrigation, drought, and rehydration), and SA applications (without the addition of a regulator (0) and with the addition of SA at concentrations equal to 0.5, 1, and 1.5 mM). In general, exogenous SA application increased stomatal conductance (gs) responses and modified the fluorescence parameters (ΦPSII, qP, ETR, NPQ, D, and E) of sweet pepper plants subjected to drought followed by rehydration. It was found that the use of SA, especially at concentrations of 1 mM in combination with rehydration, modulates gs, which is reflected in a higher electron transport rate. This, along with the production of photosynthetic pigments, suggests that H2O2 did not cause membrane damage, thereby mitigating the water deficit in pepper plants. Plants under drought conditions and rehydration with foliar SA application at concentrations of 1 mM demonstrated protection against damage resulting from water stress. Focusing on sustainable productivity, foliar SA application of 1 mM could be recommended as a technique to overcome the adverse effects of water stress on pepper plants cultivated in arid and semi-arid regions.

Combined Method Comprising Low Burden Physiological Measurements with Dry Electrodes and Machine Learning for Classification of Visually Induced Motion Sickness in Remote-Controlled Excavator

The construction industry is actively developing remote-controlled excavators to address labor shortages and improve work safety. However, visually induced motion sickness (VIMS) remains a concern in the remote operation of construction machinery. To predict the occurrence and severity of VIMS, we developed a prototype system that acquires multiple physiological signals with different mechanisms under a low burden and detects VIMS from the collected data. Signals during VIMS were recorded from nine healthy adult males operating excavator simulators equipped with multiple displays and a head-mounted display. Light gradient-boosting machine-based VIMS detection binary classification models were constructed using approximately 30,000 s of time-series data, comprising 23 features derived from the physiological signals. These models were validated using leave-one-out cross-validation on seven participants who experienced severe VIMS and evaluated through area under the curve (AUC) scores. The mean receiver operating characteristic curve AUC score was 0.84, and the mean precision–recall curve AUC score was 0.71. All features were incorporated into the models, with saccade frequency and skin conductance response identified as particularly important. These trends aligned with subjective assessments of VIMS severity. This study contributes to advancing the use of remote-controlled machinery by addressing a critical challenge to operator performance and safety.

The effects of noise on objective and subjective measures during speech recognition tasks as stress indicators: preliminary results

Objective indicators of stress associated with annoyance scales are essential tools to advance knowledge in the area. Electrodermal activity (EDA) can be used to evaluate physiological responses, providing a picture of autonomic nervous system. Twenty-five adults were evaluated at three situations of speech recognition tasks with monosyllables: in quiet, competitive noise at 65 dBA and 75 dBA. After each situation with noise, the annoyance scale was applied. After, low-pass filtering was used, and phasic phase was analyzed. Results showed that the percentage of speech recognition hits decreased significantly with noise at 75 dBA (p&lt;0.01), when compared to the situation without noise. Furthermore, it was found that annoyance increased significantly as noise at 75 dBA (p&lt;0.01), when compared to 65 dBA. In relation to EDA, there was a significant increase in the number of peaks when comparing speech recognition situations without noise and with noise at 75 dBA (p&lt;0.01), but not for noise at 65 dBA. Regarding the amplitude of the first skin conductance response peak, there was no significant difference between the three situations. These findings suggest that higher noise levels impact on speech recognition and annoyance, causing greater listening effort and increasing stress levels.

Between Scylla and Charybdis: Fixed-Ratio Avoidance Response Effort and Unavoidable Shock Extinction in Humans

Avoidance of potential threat may become maladaptive when it is indiscriminate and resistant to change. Here, we investigated the resistance to change of high and low avoidance response effort when avoidance extinction involved unavoidable presentations of the aversive event (shock) in humans. Following fear conditioning, participants prevented upcoming shock delivery by responding on high (i.e., fixed ratio, FR-20) and low (FR-5) negative reinforcement schedules. Next, noneliminable shock was used for an avoidance extinction procedure whereby responding was followed by, rather than prevented, shock. During a subsequent standard extinction and response prevention test phase, we found that High effort (FR-20) avoidance would be more readily extinguished than Low effort (FR-5) avoidance. It was also predicted that fear, threat expectancy, and psychophysiological (skin conductance) responses would decrease on avoidable trials and increase on unavoidable trials before extinguishing to low levels. It was found that in the final extinction re-test phase when avoidance was possible, responding increased, particularly for low effort cues. Both fear and expectancy remained high. Individual differences on clinically relevant measures of trait anxiety, intolerance of uncertainty and experiential avoidance were associated with greater levels of fear and threat expectancy. Overall, unavoidable shock extinction may hold promise for further translational investigations of avoidance learning, extinction, and clinical treatment development.

Impaired microvascular insulin-dependent dilation in women with a history of gestational diabetes.

Women with a history of gestational diabetes mellitus (GDM) have a significantly greater lifetime risk of developing cardiovascular disease and type 2 diabetes compared with women who had an uncomplicated pregnancy (HC). Microvascular endothelial dysfunction, mediated via reduced nitric oxide (NO)-dependent dilation secondary to increases in oxidative stress, persists after pregnancy complicated by GDM. We examined whether this microvascular dysfunction reduces insulin-mediated vascular responses in women with a history of GDM. We assessed in vivo microvascular endothelium-dependent vasodilator function by measuring cutaneous vascular conductance responses to graded infusions of acetylcholine (10-10-10-1 M) and insulin (10-8-10-4 M) in control sites and sites treated with 15 mM l-NAME [NG-nitro-l-arginine methyl ester; NO-synthase (NOS) inhibitor] or 5 mM l-ascorbate. We also measured protein expression of total endothelial NOS (eNOS), insulin-mediated eNOS phosphorylation, and endothelial nitrotyrosine in isolated endothelial cells from GDM and HC. Women with a history of GDM had reduced acetylcholine (P < 0.001)- and insulin (P < 0.001)-mediated dilation, and the NO-dependent responses to both acetylcholine (P = 0.006) and insulin (P = 0.006) were reduced in GDM compared with HC. Insulin stimulation increased phosphorylated eNOS content in HC (P = 0.009) but had no effect in GDM (P = 0.306). Ascorbate treatment increased acetylcholine (P < 0.001)- and insulin (P < 0.001)-mediated dilation in GDM, and endothelial cell nitrotyrosine expression was higher in GDM compared with HC (P = 0.014). Women with a history of GDM have attenuated microvascular vasodilation responses to insulin, and this attenuation is mediated, in part, by reduced NO-dependent mechanisms. Our findings further implicate increased endothelial oxidative stress in this microvascular insulin resistance.NEW & NOTEWORTHY Women who have gestational diabetes during pregnancy are at a greater risk for cardiovascular disease and type 2 diabetes in the decade following pregnancy. The mechanisms mediating this increased risk are unclear. Herein, we demonstrate that insulin-dependent microvascular responses are reduced in women who had gestational diabetes, despite the remission of glucose intolerance. This reduced microvascular sensitivity to insulin may contribute to increased cardiovascular disease and type 2 diabetes risk in these women.

Evaluating the Effects of Different Cognitive Tasks on Autonomic Nervous System Responses: Implementation of a High-Precision, Low-Cost Complementary Method.

We developed a low-cost, user-friendly complementary research tool to evaluate autonomic nervous system (ANS) activity at varying levels of cognitive workload. This was achieved using visual stimuli as cognitive tasks, administered through a specially designed computer-based test battery. To assess sympathetic stress responses, skin conductance response (SCR) was measured, and electrocardiograms (ECG) were recorded to evaluate heart rate variability (HRV), an indicator of cardiac vagal tone. Twenty-five healthy adults participated in the study. SCR and ECG recordings were made during both tonic and phasic phases using a computer-based system designed for visual stimuli. Participants performed a button-pressing task upon seeing the target stimulus, and the relationship between reaction time (RT) and cognitive load was evaluated. Analysis of the data showed higher skin conductance levels (SCLs) during tasks compared to baseline, indicating successful elicitation of sympathetic responses. RTs differed significantly between simple and cognitive tasks, increasing with mental load. Additionally, significant changes in vagally mediated HRV parameters during tasks compared to baseline highlighted the impact of cognitive load on the parasympathetic branch of the ANS, thereby influencing the brain-heart connection. Our findings indicate that the developed research tool can successfully induce cognitive load, significantly affecting SCL, RTs, and HRV. This validates the tool's effectiveness in evaluating ANS responses to cognitive tasks.

Role of tympanocentesis in the prevention of middle ear barotrauma induced by fast buoyant ascent escape from 200 m underwater.

We aimed to study middle ear barotrauma caused by fast compression followed by buoyant ascent escape from 200 m underwater and its effect on the auditory system, and to validate the preventive effect of tympanocentesis on middle ear barotrauma. Twenty Sprague Dawley rats were divided into two groups: rats in group A underwent a simulated fast buoyant ascent escape from a depth of 200 m, while those in group B underwent tympanocentesis before the procedure described for group A. Ear endoscopy, acoustic conductance, and auditory brainstem response (ABR) tests were conducted before and after the procedure to evaluate the severity of middle ear barotrauma and auditory function in both groups. Additionally, histopathological examination of the middle ear in both groups was conducted to evaluate the severity of middle ear barotrauma by observing submucosal haemorrhage. None of the ears in either group showed any abnormalities before the experiment. In group A, middle ear barotrauma was universally observed after the simulation procedure. The tympanograms of all ears were initially type A and became type B after the procedure. Further, after the simulation, the hearing thresholds at different frequencies (4, 8, 16, 24, and 32 kHz) assessed by ABR significantly increased compared to those before the procedure. In group B, no middle ear barotrauma was observed, and the hearing threshold at each frequency did not change significantly compared with post-puncturing. After dissecting the middle ear, gross pathological observations were consistent with the above results. Microscopically, blood accumulation and submucosal haemorrhage in the middle ear cavity were observed in group A but not in group B. Fast buoyant ascent from 200 m underwater can cause middle ear barotrauma, resulting in hearing loss. Tympanic membrane puncture can effectively prevent middle ear barotrauma caused by the rapid buoyant ascent escape procedure.