Thermal Damage Research Articles

Performance of Forensic Age Estimation by Aspartic Acid Racemization and DNA Methylation: A Systematic Review

Background Forensic age estimation is not difficult when the body is found in good condition, but in cases of severe decomposition or damage, such as burnt or separated body parts, then the analysis can only be done with bones and teeth. There has been abundant research and development in the field of related biochemistry over the years. Various molecular changes occur in hard tissues and long-lived proteins, such as those in bones and teeth during the physiological process of aging. Aspartic acid racemization and DNA methylation are still the most frequently used age estimation methods because of their advantages in accuracy. Method This study aimed to compare the accuracy of DNA methylation and aspartic acid racemization methods for age estimation. Journal articles were searched in the electronic databases PubMed, Scopus, and Semantic Scholar of 2017-2022 according to PRISMA guidelines. Result Twelve journal articles were eligible for review. The DNA methylation method is quite simple to use because of commercially available methylation kits. Furthermore, the results can be obtained relatively quickly without requiring many samples, and the method is less sensitive to thermal and other damage than the aspartic acid racemization method. Conclusion The aspartic acid racemization method for age estimation has high accuracy, especially in determining age at death. However, temperature and the condition of the teeth affect the racemization of aspartic acid. Given that DNA methylation is generally stable in a wide range of temperatures, it provides a better approach to determining the chronological age even from charred remains.

Comparison of the effects of laser systems and cold atmospheric plasma on the surface roughness and shear bond strength of flexible hybrid ceramics.

The aim of this study was to compare the effects of laser systems and cold atmospheric plasma (CAP) on the surface roughness (Ra) and shear bond strength (SBS) of flexible hybrid ceramics (FHCs). Eighty FHC samples were divided into 5 groups to be subjected to surface treatments (hydrofluoric acid (HFA), HFA + 5W Er: YAG laser (HFA + 5WE), HFA + 3W Er: YAG laser (HFA + 3WE), HFA + ultrafast fiber laser (HFA + FL), and CAP). The Er: YAG laser (AT Fidelis Plus III, Fotona, Slovenia) was operated with a 0.9mm diameter tip, delivering 250mJ and 150mJ per pulse, with output powers of 5W and 3W, and fluences of 23,623J/cm² and 14,157J/cm², respectively, at a frequency of 20Hz and a pulse duration of 600 µs for 30s. The FL (FiberLAST Inc., Turkey) was applied with a 7mm spot size, 1mJ pulse energy, 20W output power, 100kHz repetition rate, ultrashort pulse length (100 ns), and the fluence of 1,820J/cm² for 7s. The CAP (PiezoBrush PZ3, Relyon Plasma, Germany) applied to the surfaces for 80s at a treatment speed of 5 cm2/s and 100% plasma power. After the Ra values were measured, each group was divided into 2 subgroups to be cemented with total-etch (TE) and self-adhesive (SA) resin cements. The SBS of all the samples was measured. One sample was randomly selected from each group, and the fractured surfaces were examined by SEM analysis. The significance level was at P < 0.05. HFA + FL had the highest Ra values, and there was no significant difference between HFA + FL and HFA + 5WE (P > 0.05). There was no difference in Ra between CAP and HFA (P > 0.05). The highest SBS values were observed for the samples cemented with TE after HFA + FL. The difference between the SBS values of the groups cemented with TE after CAP, HFA + 5WE, HFA + 3WE, and HFA + FL was not significant (P < 0.05). The use of FL may be a promising method to improve SBS without causing thermal damage when using TE or SA cements. CAP can be recommended as a practical and safe treatment with SA cement because it is suitable for chairside use with a handheld device and does not change the physical properties of the material.

Changes in ultrasonic elastometry parameters of the liver parenchyma during its radiofrequency ablation (experimental study)

Objective. To determine in the experiment the changes in the elasticity of the liver parenchyma during its radiofrequency ablation at different distances from the electrode and their correspondence to the zones of irreversible thermal damage of the tissue. Materials and methods. The elasticity of the parenchyma of six samples of isolated porcine liver during radiofrequency ablation in automatic mode for 12 min with an initial applicator power of 50 W and its subsequent automatic increase by 10 W/min until critical impedance values were reached was evaluated by ultrasonic elastometry with the determination of the Young's modulus. The elasticity of the liver in kilopascals was determined before the start of radiofrequency ablation, during its implementation every minute for 12 minutes and 15, 30 and 60 minutes after the procedure in three zones located at a distance of 1.0, 1.8 and 3.0 cm from the applicator. Results. Before radiofrequency ablation, the elasticity of the liver parenchyma ranged from 4.1 to 9.3 kPa and averaged (6.64 ± 1.55) kPa. At the maximum power of the applicator – (109.67 ± 4.97) W – the transverse size of the hyperechogenic “cloud” at the 12th minute of the procedure was (18.0 ± 1.41) mm. The value of Young's modulus in the first zone of elastometry statistically significantly increased from the 1st minute of radiofrequency ablation and by the 11th minute reached the level of (46.38 ± 5.43) kPa and did not change significantly thereafter. In the second zone, a statistically significant increase in the value of Young's modulus to (44.22 ± 6.55) kPa was observed throughout the procedure, and after its termination it changed statistically insignificantly. In the third zone, changes in the value of Young's modulus occurred 3 minutes after the start of the procedure and continued until its completion, but its maximum value – (15.63 ± 1.57) kPa – exceeded the baseline level only about 2 times, and an hour after the completion of radiofrequency ablation, the value of Young's modulus decreased statistically significantly. Conclusions. The stiffness of the parenchyma of isolated porcine liver increases significantly during radiofrequency ablation under conditions of its sufficient duration, and depending on the distance to the electrode, these changes have different phase character. In loci corresponding to the zone of irreversible tissue necrosis, the initial slow approximately twofold increase in Young's modulus during the first 3 to 4 minutes is followed by a rapid exponential increase in the next 5 to 6 minutes and the formation of a plateau with 6 to 8 times the initial level, after which the index does not change significantly. To determine the edge of liver parenchyma ablation by elastometry, in addition to the absolute value of Young's modulus at the end of radiofrequency ablation and the multiplicity of its increase relative to the baseline value, such criteria as the three–phase nature of the increase in this indicator and the absence of its decrease within an hour after the procedure are equally important.

Managing Residual Heat Effects in Femtosecond Laser Material Processing by Pulse-on-Demand Operation

Femtosecond laser processing combines highly accurate structuring with low residual heating of materials, low thermal damage, and nonlinear absorption processes, making it suitable for the machining of transparent brittle materials. However, with high average powers and laser pulse repetition rates, residual heating becomes relevant. Here, we present a study of the femtosecond laser pulse-on-demand operation regime, combined with regular scanners, aiming to improve throughput and quality of processing regardless of the scanner’s capabilities. We developed two methods to define the needed pulse-on-demand trigger sequences that compensate for the initial accelerating scanner movements. The effects of pulse-on-demand operation were studied in detail using direct process monitoring with a fast thermal camera and indirect process monitoring with optical and topographical surface imaging of final structures, both showing clear advantages of pulse-on-demand operation in precision, thermal effects, and structure shape control. The ability to compensate for irregular scanner movement is the basis for simplified, cheaper, and faster femtosecond laser processing of brittle and heat-susceptible materials.

Analysis of failure modes and impact resistance factors of PDC cutters

The service life of PDC cutters directly affects the overall drilling performance. In hard and heterogeneous formations, PDC cutters often fail prematurely due to dynamic impacts, leading to short footage and slow penetration rates. Enhancing the dynamic impact resistance of PDC cutters is crucial for achieving one-run drilling and reducing costs. This paper systematically studies the main factors influencing and optimizing the impact resistance of PDC cutters. First, the failure modes of hundreds of returned PDC drill bits were statistically analyzed, revealing that dynamic impact failure, wear failure, thermal damage, and erosion are the primary failure modes. Among these, dynamic impact failure is the most prevalent, with dynamic impact load being the main cause. Following the successful practices of leading international drill bit companies, a set of dynamic impact test and evaluation devices for PDC cutters was designed, and corresponding testing standards were established. Based on this, 19 types of PDC cutters were tested for impact resistance, exploring the effects of cutter diameter, diamond layer thickness, chamfer, cobalt removal, and cutter design on impact resistance. An optimized design methodology to enhance impact resistance was summarized, leading to the proposal of a new arch-axe cutter design. Indoor impact test data verified the superiority of this cutter. The research results indicate that cutter design (non-standard cutters) can significantly improve the dynamic impact resistance of PDC cutters. Additionally, increasing the cutter diameter and chamfer size while reducing the diamond layer thickness also enhances the dynamic impact resistance of PDC cutters. Through the optimization of the arch-ridge design, the independently developed arch-axe cutter improved the dynamic impact resistance by 106.45% and 71.43% compared to flat circular cutters and axe-shaped cutters, respectively.

Wood Surface-Embedding of Functional Monodisperse SiO2 Microspheres for Achieving Robust, Durable, Nature-Inspired, Programmable Superrepellent Interfaces.

Nature-inspired, robust, durable, liquid-repellent interfaces have attracted considerable interest in the field of wood biomimetic intelligence science and technology application. However, realizing green environmental protection and low maintenance and replacement cost wood surfaces constructed with micro/nanoarchitectures is not an easy task. Aiming at the problem of poor waterproof performance of wood, a silicon dioxide/polydimethylsiloxane (SiO2/PDMS) self-cleaning programmable superhydrophobic coating was biomimetically constructed on the wood substrate by surface-embedded dual-dipping design based on the "substrates + nanoparticles" hybrid principle of the lotus leaf effect. This robust, durable, nature-inspired, self-cleaning, programmable superhydrophobic coating was found to have no observable impact on the original color and texture of the natural wood. The SiO2/PDMS/wood prepared exhibited exceptional liquid repellency and a high static water contact angle (WCA) of 158.5° and a low slide angle (SA) of 10°, including everyday general-purpose droplets, indicating that the introduction of the monodisperse SiO2 microspheres can effectively enhance the superhydrophobic properties of the hydrophilic wood. We applied this strategy to a variety of substrates, including wood-cellulose aerogel and wood-cellulose paper, and demonstrated that the liquid-repellent nature of the self-cleaning superhydrophobic coating remained unchanged. Moreover, the superhydrophobic surface of SiO2/PDMS/wood was preserved even after harsh abrasion conditions, including mechanical damage (sandpaper, sharp steel blade, and tapes), thermal damage (UV irradiation and low/high-temperature exposure such as steaming and freezing), chemical damage, and solvent corrosion (immersion in acid, alkali), demonstrating robust stability of the superhydrophobic coating. Furthermore, the SiO2/PDMS programmable superhydrophobic coating exhibits exceptional exciting self-cleaning and stain-resistant properties, making it offer greater possibilities in terms of scientific challenges and real-world problem-solving at biomimetic smart superhydrophobic interfaces in wood.

Facile Synthesis of Fe‐Based Metal‐Quinone Networks for Mutually Enhanced Mild Photothermal Therapy and Ferroptosis

AbstractMild photothermal therapy (MPTT) has emerged as a promising therapeutic modality for attenuating thermal damage to the normal tissues surrounding tumors, while the heat‐induced upregulation of heat shock proteins (HSPs) greatly compromises the curative efficacy of MPTT by increasing cellular thermo‐tolerance. Ferroptosis has been identified to suppress the overexpression of HSPs by the accumulation of lipid peroxides and reactive oxygen species (ROS), but is greatly restricted by overexpressed glutathione (GSH) in tumor microenvironment and undesirable ROS generation efficiency. Herein, a synergistic strategy based on the mutual enhancement of MPTT and ferroptosis is proposed for cleaving HSPs to recover tumor cell sensitivity. A facile method for fabricating a series of Fe‐based metal‐quinone networks (MQNs) by coordinated assembly is proposed and the representative FTP MQNs possess high photothermal conversion efficiency (69.3 %). Upon 808 nm laser irradiation, FTP MQNs not only trigger effective MPTT to induce apoptosis but more significantly, potentiate Fenton reaction and marked GSH consumption to boost ferroptosis, and the reinforced ferroptosis effect in turn can alleviate the thermal resistance by declining the HSP70 defense and reducing ATP levels. This study provides a valuable rationale for constructing a large library of MQNs for achieving mutual enhancement of MPTT and ferroptosis.

Fracture Mode and Thermal Damage Evolution of Sandstone Under the Coupling Effect of Thermal Treatment and Impact Load

The dynamic properties of high-temperature sandstone quickly deteriorate with different cooling methods, which leads to the instability of underground engineering rock structures. Therefore, it is of great significance to quantify the changes in the dynamic characteristics of high-temperature cooled sandstone under impact loads. Therefore, the sandstone is heated to different temperatures and cooled using three methods. A dynamic tensile test is performed using the Splitting Hopkinson Pressure Bar (SHPB) test set for high-temperature cooled sandstone. At the same time, the transient process of rock failure was examined using high-speed cameras. The influence of different temperatures and cooling methods on the thermal damage value of sandstone was analyzed, and the prediction equation was formed. The change in rock energy during rock failure under impact load was calculated.

An innovative approach to study the influence of microstructure on thermal shock resistance of porous ceramics

AbstractPorosity is a critical microstructural factor in ceramic materials, influencing their mechanical and thermal properties. However, the detailed mechanisms through which porosity, grain size, and grain boundary fracture energy affect the thermal shock resistance of porous ceramics are still not fully understood. This study introduces a dual‐scale model that integrates these microstructural parameters to predict fracture toughness and thermal shock resistance. Using the single‐edge V‐notch fracture toughness testing principle, we calculate the thermal stress intensity factor and establish its relationship with temperature differentials. The critical temperature differential, which marks the onset of thermal shock damage, is determined when the thermal stress intensity factor reaches the fracture toughness threshold. The model reveals a significant interplay between porosity, grain size, and grain boundary fracture energy, with fine‐grained ceramics (grain size &lt; 10 µm) showing a sharp decrease in fracture toughness as porosity increases, while coarser‐grained ceramics are less affected by porosity. These findings provide a deeper understanding of the microstructural optimization needed to enhance the thermal shock resistance of high‐performance porous ceramics.

A Computational Study on Effects of PID Temperature Target and RF Frequency for PID-Controlled Nonablative RF Cosmetic Systems.

Commonly adopted in cosmetic dermatology, nonablative radiofrequency (RF) devices convert high-frequency electromagnetic energy into thermal energy to induce a wound-healing response in skin tissue. However, differences in the electrical properties of different skin layers raise questions about the impact of different RF frequencies and target temperatures on treatment effectiveness. This paper presents a finite element analysis (FEA)-based computational study aimed at simulating and optimizing the effects of a proportional integral derivative (PID)-controlled RF cosmetic devices under different combinations of these two parameters during treatment. A 3D physical model for the application of a nonablative RF device was constructed using COMSOL, which included the human tissue and RF electrodes, electromagnetic and thermal boundary conditions, as well as the PID controller. FEA was performed for each of the twelve models with parameter combinations of three RF frequencies (0.1, 0.5, and 1 MHz) and three PID-controlled target temperatures (60°C, 65°C, and 70°C) plus one group without PID control. Treatment effectiveness was quantitatively assessed using the integration of tissue thermal damage fraction, i.e., thermal damage volume. In the earlier stage of heating (0-10 s), higher RF frequency resulted in a larger thermal damage volume. At 10 s, among models with a temperature target of 70°C, there is a 6.04% difference between the thermal damage volume at RF frequencies of 1.0 and 0.1 MHz. In the later stage of heating(11-80 s), the impact of RF frequency decreases. The difference in thermal damage volume caused by higher temperature targets is more significant, at 80 s, among models with an RF frequency of 1.0 MHz, the 70°C model produces 1.15 and 1.36 times more tissue thermal damage than the 65°C and 60°C models. PID controller has ensured treatment safety and uniformity, in exchange for some efficiency. Among 12 parameter combinations, the one with a temperature of 70°C and RF frequency of 1.0 MHz achieved the highest thermal damage volume, which could potentially result in the best esthetic effect. Considering users' different susceptibility to heat, engineers or physicians can select better temperature targets and RF frequencies to bring the desired cosmetic results based on thermal damage volume curves from this study.

Thermal ablation of soft tissue by a single shock wave sonication of discrete foci within the given volume

New protocols have been developed for shockwave irradiation of soft tissue volumes using trajectories uniformly filled within the given shape by discrete foci, while pulsed millisecond sonication immediately formed a single ablation. The influence of the initial peak power with the same time-average power, the interfocus distance and the geometry of the external contour of the trajectory on the shape, volume and ablation rate was analyzed. The most advantageous is the saturation mode using a trajectory with an interfocus step 1.5 times greater than the transverse size of a single lesion. To obtain volumes of thermal ablation on the order of cubic centimeters, layer-by-layer sonication protocols are proposed, which allow to 2.5 times greater thermal ablation rate compared with protocols used in clinical practice. The advantage of the proposed shockwave protocols is the possibility of obtaining localized and predictable thermal damage without accompanying MRI monitoring.

Development and evaluation of a precision heat treatment device for delaying postharvest softening of muskmelon

To extend the limited commercial storage of muskmelons due to insufficient shelf life, a heat treatment device with precise temperature control was designed and applied to three muskmelon varieties: "Xizhou Mi 25" (XZM), "Jinmi 3" (JM), and "Jiashi" (JS). The effectiveness of this device and the effect of heat treatment on the softening of muskmelons during storage were evaluated. The results indicated no significant difference between the temperatures set by the control system and the actual measured temperatures (p > 0.05), demonstrating the high accuracy of the temperature control system. After optimization of the heat treatment device, no thermal damage was observed in the heat-treated group of muskmelons. The energy consumption of the heat treatment device was only half that of the insulated tank. By the 18th day of storage, the protopectin (PP) content in the heat-treated group was significantly lower than in the control group. Correlation analysis showed that hardness was positively correlated with PP content and negatively correlated with water-soluble pectin (WSP). Additionally, cell wall metabolism-related enzyme activities were negatively correlated with PP content. These results indicated that the heat treatment effectively delayed muskmelon softening during postharvest storage. This study provides technical support for the industrial application of heat treatment devices in muskmelon preservation.

Characterization of microstructure and moisture distribution evolution of concrete using AC impedance spectroscopy

In this study, the AC impedance responses of concrete with different microstructures and water contents at elevated temperatures are examined. First, an equivalent circuit model of concrete is proposed. The simulation results of the equivalent circuit are in good agreement with the AC impedance spectrum. Then, semi-infinite, infinite, and barrier diffusion modes of water diffusion within concrete are proposed. The quantitative relationships between AC impedance parameters and moisture content of concrete are established. Finally, the equivalent porosity and thermal damage are characterized using AC impedance parameters. Both show linear relation with the total porosity obtained experimentally by porosity tests. Therefore, AC impedance spectroscopy can quantitatively characterize the internal microstructure and moisture content evolution, and further reveal the mechanism of the macro performance of concrete.

Damage power enhancement of fuel air explosive with typical metal hydrides additions

To study the damage power enhancement of fuel air explosive (FAE) with metal hydrides, the effects of metal hydrides (TiH2, MgH2, ZrH2) powders on shock wave and thermal damage of pure propylene oxide (PO) were explored using a 20 L spherical explosion test system combined with colorimetric thermometry technology. The experimental results showed that compared with the base metal powders, the explosion overpressures, maximum pressure rise rates and maximum average temperatures of the solid-liquid mixed fuel with the metal hydrides (TiH2, MgH2, ZrH2) powders increased by 11.04 %, 22.61 %, 4.80 % and 26.68 %, 38.18 %, 13.91 % as well as 6.85 %, 8.57 %, 1.34 %, respectively. Furthermore, the effects of metal hydride powders on the cloud explosion fuel were better than those of Al powders, and MgH2 powders had the most significant effects on the damage power enhancement of pure PO. Metal hydride powders as high-energy additives could improve the energy release characteristics of FAE.

Recognition of Heat-Damaged Corn Seeds Based on Fusion of Laser Ultrasonic Signal and Infrared Image Features

Corn is widely cultivated on a global scale. However, high temperatures during storage and transportation can lead to thermal damage to the kernels, negatively impacting their quality. Traditional methods for identifying heat-damaged grains primarily rely on manual inspection, which is characterized by low efficiency and accuracy. This study proposes a novel identification method that integrates laser ultrasonic signals with infrared image texture features. A pulsed laser stimulates the seeds to generate laser ultrasonic signals, while an infrared camera captures infrared images of the seeds. We extract time-domain, frequency-domain, and Hilbert-domain features from the laser ultrasonic signals, in addition to texture features from the infrared images. These features are combined using Canonical Correlation Analysis (CCA). Subsequently, the fused features are classified using a Backpropagation (BP) neural network, Support Vector Machine (SVM), and Particle Swarm Optimization–Support Vector Machine (PSO–SVM). The results indicate that the recognition rate achieved with the fused ‘signal-image’ features reaches 99.17%, providing a novel approach for detecting heat-damaged corn seeds.

A large field-of-view, single-cell-resolution two- and three-photon microscope for deep and wide imaging

In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain's circuitry. Multiphoton microscopy, a powerful tool for deep-tissue imaging, has received sustained interest in advancing its speed, field of view and imaging depth. However, to avoid thermal damage in scattering biological tissue, field of view decreases exponentially as imaging depth increases. We present a suite of innovations to optimize three-photon microscopy for large field-of-view imaging at depths unreachable by two-photon microscopy. These techniques enable us to image neuronal activities of transgenic animals expressing protein calcium sensors in a ~ 3.5-mm diameter field-of-view with single-cell resolution in the deepest cortical layer of mouse brains. We further demonstrate simultaneous large field-of-view two-photon and three-photon imaging, subcortical imaging in the mouse brain, and whole-brain imaging in adult zebrafish. The demonstrated techniques can be integrated into typical multiphoton microscopes to enlarge field of view for system-level neural circuit research.

Precise photothermal treatment of bacterial infection mediated by charge-switchable nanoplatform with acylsulfonamide betaine surface

Photothermal therapy (PTT) offers a promising approach for the treatment of drug-resistant bacterial-infected wounds, yet it requires precise targeting of thermal damage to bacteria rather than healthy tissues. Herein, ultrasmall CuS NPs modified with polyzwitterion containing acylsulfonamide betaine (PCBSA@CuS), which provides a sensitive and reversible charge conversion around pH 6.8, are used to enhance the healing of bacteria-infected wounds. In the acidic infection microenvironment, the majority of PCBSA@CuS can electrostatically adsorb onto bacterial cells through cationic exposure, resulting in direct damage and death of bacteria upon NIR irradiation. Additionally, the photothermal NPs rapidly return to a zwitterionic nature in normal physiological environments, ensuring lower affinity and avoiding thermal damage to healthy tissues during continuous PTT. Compared to inert photothermal systems such as PEG-modified CuS NPs, the NPs used in this study exhibited higher bactericidal and wound healing efficacy. Therefore, this nano-antibacterial agent with highly sensitive thermal-targeting function provides a novel photothermal strategy for efficient and biosafe treatment of infected wounds.

Energy-Based Skin Rejuvenation: A Review of Mechanisms and Thermal Effects.

Energy-based photoelectric and ultrasonic devices are essential for skin rejuvenation and resurfacing in the field of plastic surgery and dermatology. Both functionality and appearance are impacted by factors that cause skin to age, and various energy types have variable skin penetration depths and modes of transmission. The objective is to advise safe and efficient antiaging treatment while precisely and sensitively controlling and assessing the extent of thermal damage to tissues caused by different kinds of energy-based devices. A literature search was conducted on PubMed to review the mechanisms of action and thermal effects of photoelectric and ultrasonic devices in skin remodeling applications. This paper reviews the thermal effects of energy-based devices in skin resurfacing applications, including the tissue level and molecular biochemical level. It seeks to summarize the distribution form, depth of action, and influencing factors of thermal effects in combination with the mechanisms of action of various types of devices. Accurate control of thermal damage is crucial for safe and effective skin remodeling treatments. Thorough investigation of molecular biochemical indicators and signaling pathways is needed for real-time monitoring and prevention of severe thermal injury. Ongoing research and technological advancements will improve the accuracy and control of thermal damage during treatments.

Effect of steam curing regime on the mechanical properties, drying shrinkage, and microstructure of mortar in high-altitude areas with low air pressure

Low air pressure in plateau regions impacts the microstructure and macroscopic properties of cement-based materials by altering water transport. However, the efficiency of steam curing, a frequently-used curing approach, under these conditions has been inadequately studied. This work compares the effects of steam curing on the mechanical properties, drying shrinkage, and microstructure of cement-based materials at low air pressure. Results show that low air pressure decreases the compressive strength and increases the drying shrinkage of steam-cured mortar due to reduced hydration and increased total pore volume. Optimally, a steam curing temperature of 40°C to 60°C minimizes thermal damage, and a pre-curing time of 3 hours yields the best mechanical properties and drying shrinkage. Additionally, a field case confirms the effectiveness of the proposed steam curing regime; the demolding strength of precast beams meets engineering standards, and drying shrinkage fluctuates significantly with daily temperature changes. Notably, a 25.30 % difference in 90-day drying shrinkage between steam-cured and non-steam-cured specimens underscores the necessity of steam curing in high-altitude areas. These findings are crucial for optimizing steam curing practices in low-pressure environments.

Comparative Assessment of Thermal Damage Induced by Bipolar Forceps in a Bovine Liver.

Bipolar electrocautery systems in neurosurgical procedures may induce thermal damage to adjacent tissues, especially neural tissues. Therefore, it is crucial to control thermal spread from the tips of bipolar forceps into adjacent tissues. The goal of this study was to compare the thermal damage induced in unintended adjacent tissues during coagulation with 6 different bipolar forceps. Fresh ex vivo bovine liver tissues were coagulated with 6 different bipolar forceps: Aesculap® nonstick, Atlas Choice™, ISOCOOL®, SilverGlide®, Spetzler™-Malis®, and VersaTru® (45 trials per bipolar forceps). For all forceps, coagulation was performed with a power setting of 35 Malis units, 1-mm tip spacing, and 3-second activation time. Tissue samples were evaluated for the extent of thermal damage (30 trials per bipolar forceps). Tissue temperatures were measured with thermocouples placed in the tissues (15 trials per bipolar forceps). The area and maximum depth of thermal damage were measured manually with image analysis software. The injury area induced by ISOCOOL® and Atlas Choice™ bipolar forceps was significantly less than that of the Aesculap® nonstick (P < .001), SilverGlide® (P < .001), Spetzler™-Malis® (P < .001), and VersaTru® (P < .001). The areas of thermal injury caused by the ISOCOOL® and Atlas Choice™ forceps were not statistically significantly different from each other (P = .08). Lesions from the ISOCOOL® and Atlas Choice™ forceps showed significantly less depth of injury than the Aesculap® nonstick (P = .001), SilverGlide® (P < .001), Spetzler™-Malis® (P < .001), and VersaTru® (P < .001). There was no statistically significant difference in the depth of thermal injury between the ISOCOOL® and Atlas Choice™ forceps (P = 1.0). Bipolar forceps that effectively limit excessive thermal dissipation reduce the risk of unintended injury to adjacent or peripheral tissues. In an ex vivo bovine liver model, coagulation tests with ISOCOOL® and Atlas Choice™ bipolar forceps resulted in less depth and lower mean injury areas compared with other forceps.