Exposure Dose Research Articles

Effects of prenatal alcohol exposure on the olfactory system development.

Fetal Alcohol Spectrum Disorders (FASD), resulting from maternal alcohol consumption during pregnancy, are a prominent non-genetic cause of physical disabilities and brain damage in children. Alongside common symptoms like distinct facial features and neurocognitive deficits, sensory anomalies, including olfactory dysfunction, are frequently noted in FASD-afflicted children. However, the precise mechanisms underpinning the olfactory abnormalities induced by prenatal alcohol exposure (PAE) remain elusive. Utilizing rodents as a model organism with varying timing, duration, dosage, and administration routes of alcohol exposure, prior studies have documented impairments in olfactory system development caused by PAE. Many reported a reduction in the olfactory bulb (OB) volume accompanied by reduced OB neuron counts, suggesting the OB is a brain region vulnerable to PAE. In contrast, no significant olfactory system defects were observed in some studies, though subtle alterations might exist. These findings suggest that the timing, duration, and extent of fetal alcohol exposure can yield diverse effects on olfactory system development. To enhance comprehension of PAE-induced olfactory dysfunctions, this review summarizes key findings from previous research on the olfactory systems of offspring prenatally exposed to alcohol.

A clinical comparative study of dual LVIS devices and single flow diversion stenting for the treatment of unruptured V3-V4 vertebral artery dissection.

This study aims to compare the efficacy and safety of using overlapping low-profile visualized intraluminal support (LVIS) devices and flow diversion (FD) for the treatment of unruptured vertebral artery dissection (VAD) in the V3-V4 segments. The clinical and imaging data of 71 patients with unruptured VAD in the V3-V4 segments who underwent either dual LVIS stenting (d-LVIS group) or single FD stenting (FD group) at our center from September 2014 to December 2021 were retrospectively analyzed. Immediate postoperative angiography revealed no significant difference in the degree of occlusion between the two groups in treating vertebral artery dissecting aneurysms (with or without noncompact coiling). However, the d-LVIS group had significantly higher fluoroscopy exposure time and total radiation exposure dose compared to the FD group. During the perioperative period, two cases of pontine infarction and one case of acute thrombosis were encountered. One patient died from subarachnoid hemorrhage during the follow-up period. For dissecting the aneurysm, angiographic follow-up (8.56 ± 1.96 months) showed similar healing outcomes between the two groups (with or without noncompact coiling). However, seven patients (7/40, 17.5%) showed poor healing and one patient showed mild in-stent stenosis. For simple dissection, angiographic follow-up (8.78 ± 1.83 months) showed patent lumens in both groups, with all dissections healing well, and two patients having mild in-stent stenosis. Both methods could effectively treat unruptured VAD in V3-V4 segments. Nevertheless, simple FD implantation is relatively easier to perform and involves lower radiation exposure.

Impact of the exposure of sublethal dose of mosquito coil on the development of insecticide resistance in Aedes aegypti (L.) (Diptera: Culicidae).

Mosquito coil is commonly used in many African households for protection against mosquito bites. The coil usually has semi-volatile pyrethroids as an active ingredient, which usually diffuse across open space, and the cloud either kills mosquitoes that are exposed, or mosquitoes can be exposed to sublethal doses of the insecticides. This study was conducted to assess the impact of sublethal doses of mosquito coil on the development of insecticide resistance in Aedes aegypti, a major vector for dengue fever and several other arboviral diseases. A laboratory colony of Ae. aegypti was exposed to sublethal doses of a meperfluthrin-based mosquito coil in a Peet-Grady chamber once per generation for 16 generations. The susceptibility of the exposed colony to a diagnostic dose of the mosquito coil as well as to three other insecticides was determined. Three different kdr mutations and five enzyme activities were evaluated in both the exposed and control colonies. After 16 generations of sublethal exposure to mosquito coils, the full diagnostic dose of the coil caused 68% mortality to the exposed colony compared to 100% mortality in the control colony. Mortality caused by deltamethrin (0.05%) was also significantly lower in the exposed colony. The frequency of 1016I kdr mutation as well as MFO and alpha esterase activities were higher in the exposed colony compared to the control colony. This study provides evidence of the development of pyrethroid resistance in an Ae. aegypti population due to sublethal exposure to mosquito coil for 16 generations. Given the large-scale use of mosquito coils in many African households, its role as a pyrethroid resistance selection source should be taken into consideration when designing resistance management strategies.

Vaporized nicotine in utero results in reduced birthweight, increased locomotion, and decreased voluntary exercise, dependent on sex and diet in offspring.

Rationale Clinical research has shown that prenatal exposure to nicotine may result in increased obesity risk later in life. Preclinical research has corroborated this finding, but few studies have investigated inhaled nicotine or the interaction with diet on obesity risk. Objective The aim of this study was to investigate the effects of prenatal nicotine exposure on both direct and indirect obesity measures, with both sex and diet as factors. Methods Pregnant rats were exposed to either vehicle or nicotine vapor (24mg/mL or 59mg/mL) throughout the entire gestational period. Offspring from each treatment group were given either a normal diet or a high fat diet starting at postnatal day 22. Caloric intake, body weight, spontaneous locomotion, sleep/wake activity, and voluntary exercise were measured throughout adolescence. Pregnancy weight gain and pup birthweights were collected to further measure developmental effects of prenatal nicotine exposure. Results Both maternal weight gain during pregnancy and pup weight at birth were decreased with prenatal nicotine exposure. Early adolescent males showed increased spontaneous activity in the open field following prenatal nicotine exposure compared to vehicle counterparts, particularly those given high-fat diet. Additionally, high dose nicotine prenatal treated males ran significantly less distance on the running wheel in late adolescence compared to vehicle counterparts, in the normal diet group only. Conclusion The results presented here show decreased birthweight, hyperactivity, and decreased voluntary exercise in adolescence following prenatal nicotine exposure in dose, sex, and diet dependent manners, which could lead to increased obesity risk in adulthood.

Hematologic Toxicity and Bone Marrow-Sparing Strategies in Chemoradiation for Locally Advanced Cervical Cancer: A Systematic Review.

The standard treatment for locally advanced cervical cancer typically includes concomitant chemoradiation, a regimen known to induce severe hematologic toxicity (HT). Particularly, pelvic bone marrow dose exposure has been identified as a contributing factor to this hematologic toxicity. Chemotherapy further increases bone marrow suppression, often necessitating treatment interruptions or dose reductions. A systematic search for original articles published between 1 January 2006 and 7 January 2024 that reported on chemoradiotherapy for locally advanced cervical cancer and hematologic toxicities was conducted. Twenty-four articles comprising 1539 patients were included in the final analysis. HT of grade 2 and higher was observed across all studies and frequently exceeded 50%. When correlating active pelvic bone marrow and HT, significant correlations were found for volumes between 10 and 45 Gy and HT of grade 3 and higher. Several dose recommendations for pelvic bone and pelvic bone marrow sparing to reduce HT were established, including V10 < 90-95%, V20 < 65-86.6% and V40 < 22.8-40%. Applying dose constraints to the pelvic bone/bone marrow is a promising approach for reducing HT, and thus reliable implementation of therapy. However, prospective randomized controlled trials are needed to define precise dose constraints and optimize clinical strategies.

Micro/nanoplastic pollution heterogeneously increased greenhouse gas emissions from wetlands: A multilevel meta-analysis

The ubiquitous presence of micro/nanoplastics (MNPs) in the environment poses high potential risks to living organisms and ecosystems. Wetlands are important sinks for MNPs, which can impact the ecological and environmental functions of wetland systems. However, the responses of greenhouse gas (GHG) emissions from wetlands to MNPs have rarely been evaluated. A multilevel meta-analysis was conducted to assess the effect of MNPs on GHG (CO2, CH4, and N2O) emissions from wetlands. The results showed that the presence of MNPs generally led to increases in GHG emissions from wetlands, especially N2O emissions. MNP type and exposure dose were the decisive factors influencing wetland GHG emissions, with CO2 and N2O emissions stimulated by biodegradable MNPs made of polylactic acid and by a high MNP dose of 1–2%, while polystyrene reduced CO2 and N2O emissions, and a low MNP dose of less than 0.5% increased CH4 emissions. CO2 emissions from the sediment of coastal wetlands were more sensitive to MNP pollution, while CH4 emissions from the sediment of freshwater wetlands were significantly increased by MNP pollution. Furthermore, microbial diversity and the number of carbon–nitrogen cycling functional genes associated with GHG emissions in wetlands were increased by MNPs. More research on the effect of MNPs on GHG emissions from wetlands over a longer time is needed, especially in real wetland ecosystems with aquatic organisms.

Evaluation of Cell Cycle-Dependent Migration Activity after X-ray Exposure: A Radiobiological Approach for Optimization of Radiotherapy with Cell Cycle-Targeting Agents.

Radiotherapy with cell cycle-specific anticancer agents has become an important option in the control of both primary tumors and metastases. Here, we used image analysis algorithms that enable quick segmentation and tracking to describe a radiobiological approach for the optimized selection of cell cycle-targeting anticancer drugs for radiotherapy. We confirmed cell cycle-synchronization using human cervical cancer HeLa cells expressing a fluorescent ubiquitination-based cell cycle indicator (FUCCI) as a cell cycle-monitoring probe. Cells synchronized in the G1 and G2 phases were irradiated with X rays at 0.5-2 Gy. Each cell was identified using Cellpose, a deep learning-based algorithm for cellular segmentation, and the velocity and direction of migration were analyzed using the TrackMate plugin in Fiji ImageJ. G1 phase synchronized cells showed a dose-dependent decrease in velocity after irradiation, while G2 cells tended to increase their velocity. The migration pattern of all cells appeared to be a random walk model, regardless of the exposure dose. In addition, we used cisplatin to arrest the cell cycle. HeLa-FUCCI cells arrested at the G2 phase via cisplatin treatment showed enhanced cell migration after X-ray exposure. These results indicated that anticancer agents that arrest the cell cycle of cancer cells in a specific phase may enhance cell migration after radiotherapy. Our approach, using cellular segmentation and tracking algorithms, could enhance the radiobiological assessment of cell cycle-specific migration after irradiation to aid in optimizing radiotherapy using cell cycle-targeting agents.

Comprehensively evaluating the performance of Elekta high-definition dynamic radiosurgery for hypofractionated stereotactic radiotherapy of multiple brain metastases

PurposeTo evaluate the dosimetric and delivery performance of Elekta high-definition dynamic radiosurgery (HDRS) in hypofractionated stereotactic radiotherapy (HSRT) for multiple brain metastases (BMs) by comparison with a conventional single-isocenter noncoplanar volumetric modulated arc therapy (VMAT) technique using the RayStation treatment planning system (TPS). Materials and methodsFrom June 2022 to October 2023, thirty-two patients (a total of 140 BMs) treated with HSRT (30–48 Gy/3-6f) via HDRS-based single-isocenter noncoplanar VMAT (HDRS-VMAT) were retrospectively selected for this study. Each patient was replanned using RayStation TPS-based single-isocenter noncoplanar VMAT (RayStation-VMAT). HDRS-VMAT and RayStation-VMAT plans were compared in terms of the gradient index (GI), conformity index (CI), normal brain tissue (NBT) dose exposure, monitor units (MUs), homogeneity index (HI), delivery accuracy, and beam-on time (BOT). ResultsCompared with the RayStation-VMAT plan, the HDRS-VMAT plan achieved superior CI (1.14 ± 0.09 vs. 1.23 ± 0.12, P < 0.001) and GI (5.23 ± 1.18 vs. 7.83 ± 2.75, p < 0.001) but had greater HI values. Compared with the RyaStation-VMAT plan, the HDRS-VMAT plan also yielded significantly lower NBT dose exposures (V23Gy, V21Gy, V18Gy, V12Gy and Dmean) but at the cost of increased MUs (3659.16 ± 1225.28 vs. 2536.23 ± 785.80, p < 0.001). The difference in BOTs was minimal (<1 min), which was not considered clinically significant. Furthermore, the HDRS-VMAT exhibited a higher gamma passing rate across all criteria (P < 0.001), particularly under stricter criteria (2%/1 mm), achieving an approximately 3% increase. ConclusionCompared with RaySation-VMAT, HDRS-VMAT offers superior target conformity, better NBT sparing, and higher delivery accuracy while maintaining comparable delivery efficiency. This represents a promising approach for HSRT of multiple BMs.

THE PROBLEM OF REGULATING FUNGICIDES ON THE SKIN SURFACE FOR OCCUPATIONAL SKIN DISEASE IN AGRICULTURAL WORKERS’ RISK PREDICTION

The aim. To establish the norms of fungicides on the skin surface and predicting the risk of occupational skin pathology in agricultural workers to develop measures to prevent diseases caused by dermal exposure to pesticides. Materials and methods. The natural experiment was performed in accordance with modern requirements (European Food Safety Authority (2022), and the risk assessment was carried out according to the Recommendations (Approved by the Ministry of Health of Ukraine No. 324 issued on 13.05.2009) with different methods of spraying techniques: rod, air blast fan spraying, pre-sowing, aviation, knapsack treatment. 17 series of natural experiments were performed, and the air of the working zone area (n =56) and dermal exposure (n =56) were analyzed for each worker with different pesticide application methods. Quantitative determination of pesticide content was carried out by gas-liquid and high-performance liquid chromatography methods. The results were statistically processed using a package of licensed statistical programs MedStat v.5.2 (Copyright © 2003-2019) and Microsoft® Excel® for Microsoft 365 MSO. Results. It was established that there is pesticide contamination, mainly of the gloves of tank filling operators when preparing working solutions. No contamination of the skin surface was detected; only pesticide residues were present on the surface of the workers’ overalls. A comparison of the exposure dose in case of percutaneous exposure during the performance of technological operations with different methods of processing, dermal equivalents of Acceptable Operator Exposure Level of pesticide to workers’ skin (DE AOEL) and the allowable dermal dose for professional contingents (ADderm) and the hazard coefficients by dermal exposure (HCderm) showed that that dermal exposure during individual technological operations with different processing methods had a reliable difference between processing methods, but there is no difference within one application method. Conclusions. During the comparison of the hazard coefficients for dermal exposure, calculated according to different models, no significant difference was found between the risks calculated according to DE AOEL and ADderm for individual technological operations in various treatment methods, except for the operator who performed knapsack treatment and the risk calculated according to ADderm is significantly lower compared to the DE AOEL risk.

Effects of cell parameters on accurate calculation of activation dose after DT explosion for local hot spots in laser-driven ICF facilities

Instruments placed in the target chamber will be highly activated after DT explosion in laser-driven ICF experiments, especially for the part near the chamber center. Operations near those local hot spots are the main concern for radiation protection due to its high contribution to the occupation exposure dose, therefore it becomes very important to calculate the dose during the operating process accurately. Cell-based rigorous two-step (R2S) method has been introduced to deal with the activated objects with highly heterogeneous distribution, and the effects of cell size, materials as well as radiation source have also been specified to improve the accuracy of simulations. Results for a typical model sample show that with a given distribution of radiation source, cell size in the simulations placed a significant influence on the accuracy of the radiation field. A cell size of 50 cm for a 100 cm cone-shaped sample will lead to the inaccuracy of the radiation field as large as an order in magnitude within the location 50 cm from the surface of the sample. While for the same sample model, cell size should be limited to smaller than 2 cm to ensure an accuracy lower than ±10 %. In addition, the effects of the material and source energy on the calculation accuracy for the radiation field could be neglected if the cell size is limited to smaller than 5 cm. Furthermore, the influence of cell size increased as the distance from the sample surface decreased, which indicates that appropriate cell size must be chosen to ensure the accuracy of dose estimation, especially for surface contact operations. Besides, a significant difference between the effective dose and skin-equivalent dose has been observed for the typical mode used in the calculations.

Radiation Exposure and Safety Considerations in Interventional Radiology: Comparison of a Twin Robotic X-ray System to a Conventional Angiography System.

Background/Objectives: To evaluate radiation exposure in standard interventional radiology procedures using a twin robotic X-ray system compared to a state-of-the-art conventional angiography system. Methods: Standard interventional radiology procedures (port implantation, SIRT, and pelvic angiography) were simulated using an anthropomorphic Alderson RANDO phantom (Alderson Research Laboratories Inc. Stamford, CT, USA) on an above-the-table twin robotic X-ray scanner (Multitom Rax, Siemens Healthineers, Forchheim, Germany) and a conventional below-the-table angiography system (Artis Zeego, Siemens Healthineers, Forchheim, Germany). The phantom's radiation exposure (representing the potential patient on the procedure table) was measured with thermoluminescent dosimeters. Height-dependent dose curves were generated for examiners and radiation technologists in representative positions using a RaySafe X2 system (RaySafe, Billdal, Sweden). Results: For all scenarios, the device-specific dose distribution differs depending on the imaging chain, with specific advantages and disadvantages. Radiation exposure for the patient is significantly increased when using the Multitom Rax for pelvic angiography compared to the Artis Zeego, which is evident in the dose progression through the phantom's body as well as in the organ-related radiation exposure. In line with these findings, there is an increased radiation exposure for the performing proceduralist, especially at eye level, which can be significantly minimized by using protective equipment (p < 0.001). Conclusions: In this study, the state-of-the-art conventional below-the-table angiography system is associated with lower radiation dose exposures for both the patient and the interventional radiology physician compared to an above-the-table twin robotic X-ray system for pelvic angiographies. However, in other clinical scenarios (port implantation or SIRT), both devices are suitable options with acceptable radiation exposure.

Evaluation of lower detection limit and performance analyses related to the incident angle of X-rays and absolute dose using a triple-type dosimeter

When using a wearable active-type dosimeter for real-time dosimetry during X-ray fluoroscopic procedures, medical staff should be aware of the potential for an inaccurate exposure dose due to the large angular dependence. To address this issue, our research group has proposed a triple-type active dosimeter. With this device, the incident angle of scattered X-rays can be determined based on the signal difference between two dosimeters placed side-by-side, in which the wedge filters on the entrance windows are arranged symmetrically. In addition, the absolute dose can be determined from the central dosimeter with angular dependence correction. Although the concept of using wedge filters was proven in a previous study, the wedge filter materials have not been sufficiently studied. In this study, therefore, we sought to determine which of several materials was best suited as a wedge filter material for medical applications: aluminum (Al), titanium (Ti), or copper (Cu). We analyzed the performance of dosimeters with the different wedge filter materials in terms of estimation accuracy and lower detection limit. Using a clinical fluoroscopic system with a tube voltage of 80 kV, the scattered X-rays generated from an elliptical cylinder water phantom were measured while varying the incident direction of the X-rays from −50° to +50° in 10-degree intervals. The experimental results showed that the incident angles were properly determined when using the Ti filter, but the estimation accuracy was slightly lower when using the Al and Cu filters. The accuracy of absolute dose was evaluated from the standard deviation of the absolute dose data between −50° and +50°. As a result, the accuracies when using the Al, Ti, and Cu filters were 3.6%, 3.9%, and 5.9%, respectively. The lower detection limit when using the Cu filter showed a significantly higher value (0.50 μSv/s), but that with the Ti filter was reasonable (0.07 μSv/s). Based on these experimental evaluations, we concluded that the Ti filter would be suitable for use in a triple-type dosimeter. Finally, we investigated the expected dose rates of scattered X-rays in various interventional radiology (IVR) procedures described in the literature and determined that our dosimeter could be used for actual dose measurement.

Disposable indicator card for personal monitoring of solar exposure

Although the Earths atmosphere provides substantial reduction of the incident radiant power in the most harmful spectral ranges, excessive exposure of untrained and/or unprotected human skin to solar radiation can easily result into acute and chronic adverse effects onto human skin. In order to reduce these effects, a simple tool for monitoring the incident radiant dose is proposed. We report on the design, development, lab scale fabrication, calibration and the roll-to-roll printing production of a photosensitive indicator cards intended for personal monitoring of solar exposure to which the user has been subjected. Two types of cards are being discussed. The first one is supposed as high sensitive one with a dose response to 1 and 2 SEDs, the second one is a less sensitive with a dose response to 3 and 4 SEDs. The calibration of the cards was performed with polychromatic simulated solar radiation without determining the spectral response, therefore we refer to the device as indicator card, not dosimeters. Moreover, properties of the photosensitive formulation employed for the fabrication of the indicator are presented alongside with the calibration of the printed indicator to dermatologically relevant values of the received solar exposure dose. Special attention is also paid to the large-scale practical production of such indicators by the roll-to-roll printing technology. Mechanical properties, stability, durability, practical utilisation, and other features are critically assessed.

Managing radiation safety and protection in gastroenterology in Japan: insights from the REX-GI study.

Fluoroscopy-guided gastrointestinal procedures, including gastrointestinal stenting, balloon-assisted endoscopy (BAE), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS), are essential for diagnosis and treatment in gastroenterology. Such procedures involve radiation exposure that necessitates strict safety measures to protect patients, doctors, and medical staff. The April 2020 update to Japan's Ionizing Radiation Injury Prevention Regulations for occupational exposure reduced the lens exposure dose limit to approximately one-seventh of its previous level. This change highlights the need for improved safety protocols. Without adaptation, the sustainability of fluoroscopy-based endoscopic techniques could be at risk due to the potential to exceed these new limits. This review examines the current state of medical radiation exposure in the field of gastroenterology in Japan and discusses the findings of the REX-GI study.

Film dosimetry for occupant exposure monitoring within Far-UVC installations.

Far-UVC radiation between 200 and 230 nm is a promising technology for reducing airborne disease transmission. Previous work with far-UVC lamps has demonstrated the efficacy of far-UVC radiation to inactivate bacteria and viruses while presenting minimal human health hazards. While far-UVC intentionally exposes the occupied space, effectively disinfecting air between occupants, installations must still ensure that occupant eye and skin exposure is within the recommended daily limits. This study examines far-UVC-sensitive films for measuring the dose received by occupants within two real-world far-UVC installations. The film is characterized for accuracy, angular response, wavelength response, and sources of uncertainty in film response, and used to obtain individual exposure doses that account for both the non-uniform irradiance and the unique motion of individuals within the space. Dosimetry results using the films, which account for the time-weighted average exposure of an occupant, ranged from 10% to 49% of the maximum calculated stationary dose based on peak irradiance measurements. Results from this study spotlight the need to incorporate time-weighted average considerations into the design and safety assessment of far-UVC installations to ultimately operate far-UVC technology with its full potential to prevent the spread of potentially fatal infectious diseases.

Investigation of natural and artificial radioactivity levels in travertines of the Cappadocia region in Turkey

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayası regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayası. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg−1 for 232Th, 4.21 to 13.41 Bq kg−1 for 40K, and 0.42–3.26 Bq kg−1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

Optimize projected mask images for improving three-dimensional printing accuracy for digital light processing based vat photopolymerization

Additive manufacturing technology, specifically digital light processing (DLP) based vat photopolymerization (VPP), is extensively employed for fabricating complex constructs. Nevertheless, the accuracy of DLP-VPP is hindered by challenges such as light diffraction during propagation and light penetration along the exposure axis within the photopolymeric resin. To mitigate these issues, regulating the grayscale of projected mask images offers a reliable approach to reduce undesired curing. In this study, we introduce a voxel-based multi-layer solidification model to predict the exposure dose distribution of printed parts. Based on this model, we propose a pixel-level grayscale optimization method using the gradient descent technique. This method allows us to control the accumulated exposure dose of each voxel by modifying the grayscale of individual pixels in the projected mask images, thereby improving the accuracy of the printed parts. To validate our optimization method, we conducted a series of experiments involving the printing of four representative structures using both the traditional method and our proposed optimization method. The results demonstrate that the structures produced using our optimization method exhibit superior consistency with the target geometry. This indicates a significant improvement in accuracy achieved through our optimization technique. Furthermore, our optimization method has successfully enabled the fabrication of microchannels that are previously unattainable using traditional method. This achievement highlights the immense potential of our optimization method in the realm of printing microchannels.

Use of mindfulness training to improve BAC self-estimation during a drinking episode.

Individuals are often inaccurate at estimating levels of intoxication following doses of alcohol. Previous research has shown that when required to estimate (BAC) at different time points, participants often underestimate their BACs and amounts of alcohol consumed. The present study aimed to increase drinkers' BAC estimation accuracy after drinking alcohol using mindfulness-based feedback to increase their awareness of the interoceptive cues associated with alcohol intoxication. Thirty-three adults were given 0.65 g/kg of alcohol and received one of three training conditions: BAC feedback only, body scan exercise + BAC feedback and no treatment control. Those in the BAC feedback group received feedback concerning their observed BAC during dose exposure. Participants in the body scan group received BAC feedback and underwent a mindfulness exercise to enhance their perception of the acute subjective effects of alcohol. The control group received no BAC estimation training. Participants attended four study sessions: Two training sessions where participants underwent structured training based on their condition and two retention sessions to test for the lasting effects of the training exercises. Retention tests showed that participants in both treatment groups were most accurate in estimating their BACs. There were no differences among the groups in their perceived levels of intoxication at posttraining. The findings suggest that BAC feedback, alone and in combination with, mindfulness training can improve accuracy in estimating BACs. The findings provide preliminary support for the efficacy of mindfulness training in combination with BAC feedback to improve BAC estimation accuracy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Role of Opioid Mu1-Recptors (μ1Rs) in The Inhalation of Carfentanil (CRF) Aerosol-Induced Respiratory Disorder in Awake Rats

Our previous study has shown that inhalation of fentanyl (100 mg/m3) for 10 min initially induces apnea, hypotension and bradycardia, leading to ventilatory and then cardiac arrest within 15 min in anesthetized rats (Zhuang J., et al, 2024). CRF acts on opioid mu-receptors (MORs) with a potency 100 times that of fentanyl. Inhalation of aerosolized CRF as a chemical weapon has been reported to cause sudden death in humans (Wax PM et al, 2003), but the cause of the death is not fully understood. Moreover, though the opioid-induced respiratory disorder is known to mainly result from the action of μ1Rs, the contribution of μ1Rs to the CRF-induced cardiorespiratory disorder remains unknown. Therefore, we asked whether acute inhalation of overdose CRF would induce cardiorespiratory disorder and sudden death via acting on μ1R in awake rats. The rats were exposed to aerosolized vehicle and CRF at 12.86 (low dose) or 20 mg/m3 (high dose) for 15 min with cardiorespiratory (VE, VT, fR, and HR) responses recorded for 60 min. The low and high doses of CRF induced sudden death in 1/6 and 2/2 rats respectively. Compared to aerosolized vehicle, the low dose of CRF initially decreased VE and HR by ~50% within 3 min exposure, which were maintained to the end of experiment, and all responses disappeared on the next day in the survived rats. Interestingly, the responses of breathing pattern to the CRF exposure were sequentially characterized by the rapid shallow breathing (within several seconds of the exposure), slow and deep breathing and then only slow breathing. In comparison, the dVE and bradycardia became much more aggravated after 15 min CRF aerosol-delivery in the dead rats than the survived ones, resulting in ventilatory and cardiac arrest within ~25 min post exposure. The cardiorespiratory responses to the low dose of CRF aerosol exposure were also performed after pretreatment with naloxone hydrochloride (NLX to systemically antagonize opioid receptors) or naloxonazine (NALZ to selectively antagonize μ1Rs). The CRF-induced dVE and bradycardia were fully blocked by NLX and largely alleviated by NALZ. In conclusion, our experiments not only establish a rat model of acute inhalation of CRF-induced cardiorespiratory disorder and sudden death, but also demonstrate a key role of opioid receptors, especially μ1Rs, in the CRF-induced cardiorespiratory disorder. Supported by NIH R01 grants HL163512 and DA059063. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

In Vivo Tissue Distribution of Microplastics and the Systemic Metabolic Changes After Gastrointestinal Exposure in Mice

Marcus M. Garcia, Aaron S. Romero, Seth D. Merkley, Jewel L. Meyer-Hagen, Charles Forbes, Matthew J. Campen, Julie G. In, and Eliseo F. Castillo Microplastics (MP) are slated to be the next environmental threat to humans. It is estimated humans consume approximately 5 grams of MP per week. To date, the systemic impact of MP ingestion on metabolic pathways in systemic organs have not been studied utilizing environmentally relevant doses and mixtures. To investigate the impact of ingested MPs on target metabolic pathways, mice were exposed to either polystyrene (5 μm) microspheres or a mixture of MPs consisting of polystyrene (5 μm), polyethylene (1-4 μm), and the biodegradability and biocompatible plastic, poly-(lactic-co-glycolic acid) (5 μm). Exposures were performed twice a week for four weeks at a dose of either 0, 2, or 4 mg/week via oral gastric gavage. Our findings demonstrate that, in mice, ingested MPs can pass through the gut barrier and accumulate in distant tissues. Additionally, we report on the metabolic changes that occur in the colon, liver and brain which show differential responses that are dependent on dose and type of MPs exposure. This study provides critical insight into the pervasive issues of plastic pollution and highlights dose-dependent and polymer type specific metabolic changes in the colon, liver and brain caused by MPs exposure. NIH/NIEHS 1R01 ES032037-01A1. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.