Active-bromide and surfactant synergy for enhanced microfouling control.

Biofilms are structured microbial communities encased in a matrix of self-produced extracellular polymeric substance (EPS) and pose significant challenges in various industrial cooling systems. A nuclear power plant uses a biocide active-bromide for control of biological growth in its condenser cooling system. This study is aimed at evaluating the anti-bacterial and anti-biofilm efficacy of active-bromide against planktonic and biofilm-forming bacteria that are commonly encountered in seawater cooling systems. The results demonstrated that active-bromide at the concentration used at the power plant (1 ppm) exhibited minimal killing activity against Pseudomonas aeruginosa planktonic cells. The bacterial cell surface hydrophobicity assay using Staphylococcus aureus and P. aeruginosa indicated that Triton-X 100 significantly decreased the hydrophobicity of planktonic cells, enhancing the susceptibility of the cells to active-bromide. Biofilm inhibition assays revealed limited efficacy of active-bromide at 1 ppm concentration, but significant inhibition at 5 ppm and 10 ppm. However, the addition of a surfactant, Triton-X 100, in combination with 1 ppm active-bromide displayed a synergistic effect, leading to significant biofilm dispersal of pre-formed P. aeruginosa biofilms. This observation was substantiated by epifluorescence microscopy using a live/dead bacterial assay that showed the combination treatment resulted in extensive cell death within the biofilm, as indicated by a marked increase in red fluorescence, compared to treatments with either agent alone. These findings suggest that active bromide alone may be insufficient for microfouling control in the seawater-based condenser cooling system of the power plant. Including a biocompatible surfactant that disrupts established biofilms (microfouling) can significantly improve the efficacy of active bromide treatment.

Precise control of digital dental unit to reduce aerosol and splatter production: new challenges for future epidemics.

BACKGROUND: During dental procedures, critical parameters, such as cooling condition, speed of the rotary dental turbine (handpiece), and distance and angle from pollution sources, were evaluated for transmission risk of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), simulated by spiking in a plasmid encoding a modified viral spike protein, HexaPro (S6P), in droplets and aerosols. METHODS: To simulate routine operation in dental clinics, dental procedures were conducted on a dental manikin within a digital dental unit, incorporating different dental handpiece speeds and cooling conditions. The tooth model was immersed in Coomassie brilliant blue dye and was pre-coated with 100 µL water spiked-in with S6P-encoding plasmid. Furthermore, the manikin was surrounded by filter papers and Petri dishes positioned at different distances and angles. Subsequently, the filter papers and Petri dishes were collected to evaluate the aerosol splash points and the viral load of S6P-encoding plasmid in aerosols and splatters generated during the dental procedure. RESULTS: Aerosol splashing generated a localized pollution area extended up to 60 cm, with heightened contamination risks concentrated within a 30 cm radius. Significant differences in aerosol splash points and viral load by different turbine handpiece speeds under any cooling condition (P < 0.05) were detected. The highest level of aerosol splash points and viral load were observed when the handpiece speed was set at 40,000 rpm. Conversely, the lowest level of aerosol splash point and viral load were found at a handpiece speed of 10,000 rpm. Moreover, the aerosol splash points with higher viral load were more prominent in the positions of the operator and assistant compared to other positions. Additionally, the position of the operator exhibited the highest viral load among all positions. CONCLUSIONS: To minimize the spread of aerosol and virus in clinics, dentists are supposed to adopt the minimal viable speed of a dental handpiece with limited cooling water during dental procedures. In addition, comprehensive personal protective equipment is necessary for both dental providers and dental assistants.

Flexural strength of novel glass infiltrated monochrome and multilayer high yttrium oxide containing zirconia upon various sintered cooling rates.

PURPOSE: The sintering technique and cooling strategy influence the strength of zirconia. This study examined the impact of altering the cooling rate of glass-infiltrated monolayer and multilayer 5 mol% yttria-partially stabilized zirconia (5Y-PSZ) on their strength. MATERIALS AND METHODS: One-hundred eighty (180) specimens (width × length × thickness = 10 × 20 × 2 mm) were prepared using monolayer (Mo: Cercon-xt) and multilayer (Mu: Cercon-xt ML) 5Y-PSZ. Randomly distributed specimens (n = 15/group) were sintered with traditional (T) versus glass infiltrated (G) technique and cooled down with different cooling rates: slow (S: 5°C/min), normal (N: 35°C/min), and fast (F: 70°C/min). Four-point bending test was used to measure flexural strength (σ). Microstructures were investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Three-way ANOVA and Tamhane comparisons were determined for a significant difference of σ (p < 0.05). Weibull analysis was determined for Weibull modulus (m). RESULTS: The highest σ (MPa) was seen for GMuS (696.8 ± 69.8). Mo-PSZ and Mu-PSZ showed no significant difference in σ. G-sintering presented significantly higher σ (659.9 ± 79.3) than T-sintering (426.0 ± 63.7). S-cooling (560.9 ± 126.1) had the highest σ. The highest m-value was observed in GMuN (12.1 ± 3.8). A significant difference in σ was indicated due to cooling rates and sintering techniques (p < 0.05). CONCLUSIONS: Glass infiltration significantly enhanced strength through elastic gradience. F-cooling reduced grain size, impaired grain boundary integration, and increased the tetragonal to monoclinic phase transition, significantly decreasing flexural strength in traditional sintering. Nevertheless, F-cooling was recommended for glass-infiltrated 5Y-PSZ to enhance strength while reducing processing time.

Assessment of Adaptability and Linear Dimensional Changes of Two Heat Cure Denture Base Resin with Different Cooling Techniques: An In Vitro Study.

AIM: The current study was designed to assess the linear dimensional changes and adaptability of two heat-cured denture base resins using various cooling methods. MATERIALS AND METHODS: To prepare a total of 90 acrylic resin samples (45 acrylic resin samples for each material), four rectangular stainless-steel plates measuring 25 × 25 × 10 mm were fabricated. For both groups, the material was put into the mold at the dough stage. Group I - SR Triplex Hot Heat Cure acrylic; group II - DPI Heat Cure acrylic. Both groups used the same curing procedure. One of the following three techniques was used to cool the material (15 samples from each material) once the curing cycle was finished: (A) water bath, (b) quenching, and (C) air. A traveling microscope was used to measure the distance between the markings on the acrylic samples. The data was recorded and statistically analyzed. RESULTS: In SR Triplex Hot heat cure acrylic material, the maximum linear dimensional changes were found in the quenching technique (0.242 ± 0.05), followed by the air technique (0.168 ± 0.11) and the least was found in the water bath technique (0.146 ± 0.01). In DPI Heat Cure acrylic material, the maximum linear dimensional changes were found in the quenching technique (0.284 ± 0.09), followed by the air technique (0.172 ± 0.18) and the least was found in the water bath technique (0.158 ± 0.10). There was a statistically significant difference found between these three cooling techniques. On comparison of adaptability, the water bath technique, the marginal gap SR Triplex Hot was 0.012 ± 0.02 and DPI Heat Cure was 0.013 ± 0.02. In the quenching technique, the marginal gap SR Triplex Hot was 0.019 ± 0.04 and DPI Heat Cure was 0.016 ± 0.04. In the air technique, the marginal gap SR Triplex Hot was 0.017 ± 0.01 and DPI Heat Cure was 0.019 ± 0.01. CONCLUSION: The present study concluded that among the different cooling methods, the water bath technique had the least linear dimensional change, followed by the air and quenching techniques. When comparing the materials, DPI Heat Cure acrylic resin showed a greater linear dimensional change than SR Triplex Hot heat cure acrylic resin. CLINICAL SIGNIFICANCE: During polymerization, heat-cured acrylic resins experience dimensional changes. Shrinkage and expansion are dimensional changes that occur in heat-cured acrylic resins and have an impact on the occlusal relationship and denture fit. However, the denture base's material qualities and the different temperature variations it experiences during production may have an impact on this. How to cite this article: Kannaiyan K, Rathod A, Bhushan P, et al. Assessment of Adaptability and Linear Dimensional Changes of Two Heat Cure Denture Base Resin with Different Cooling Techniques: An In Vitro Study. J Contemp Dent Pract 2024;25(3):241-244.

Twistocaloric Modeling of Elastomer Fibers and Experimental Validation.

The twistocaloric effect is attributed to the change in entropy of the material driven by torsional stress. It is responsible for the torsional refrigeration of fiber materials that has been widely exploited as one of the solid-state cooling techniques with high efficiency and low volume change rate. The lack of theories and mathematical models of twistocaloric effect, however, limits broad applications of torsional refrigeration. In this work, a twistocaloric model is established to capture the relationship between twist density and temperature variation of natural rubber fibers and thermoplastic elastomer yarns. An experimental setup consisting torsion actuator and torque sensor coupled with a temperature measurement system is built to validate the model. Using the Maxwell relationship, twistocaloric coefficient is measured by quantifying the thermal effect induced by torsion under shear strain. The experimental characterization of the twistocaloric effect in natural rubber fiber and thermoplastic elastomer yarn are consistent with the theoretical predictions.

Efficacy of regional cooling + oral dexamethasone for primary prevention of hand-foot syndrome associated with pegylated liposomal doxorubicin.

PURPOSE: Pegylated liposomal doxorubicin (PLD)-induced hand-foot syndrome (HFS) frequently lowers the quality of life of ovarian cancer patients. Wrist and ankle cooling, having a limited preventive effect, has been the commonest supportive HFS care. In this study, we retrospectively assessed the primary preventive effect of a combination of regional cooling and oral dexamethasone therapy (cooling + oral Dex) on HFS. METHODS: This study is a single-arm retrospective, observational study. Recurrent ovarian cancer patients were administered PLD ± bevacizumab. We retrospectively examined the efficacy of hands and feet cooling (from the start of PLD to the end) + oral Dex (day 1-5: 8 mg/day, day 6, 7: 4 mg/day) for primary HFS prevention. RESULTS: This study included 74 patients. The initial dose of PLD was 50 mg/m2 and 40 mg/m2 for 32 (43.2%) and 42 (56.8%) patients, respectively. HFS of Grade ≥ 2 and Grade ≥ 3 developed in five (6.8%) and one (1.4%) patient(s), respectively. The incidence of ≥ Grade 2 and ≥ Grade 3 HFS was much lower than those reported in previous studies. Dose reduction was required in 13 patients (17.6%) mainly because of neutropenia or mucositis; there was no HFS-induced dose reduction. Meanwhile, PLD therapy was discontinued mainly because of interstitial pneumonia (4 patients) and HFS (one patient). CONCLUSIONS: We demonstrated the efficacy of regional cooling and oral Dex for primary prevention of PLD-induced HFS. Although future prospective studies are needed to confirm its efficacy, this combination therapy can be considered for primary prevention of HFS in ovarian cancer patients on PLD.

Atmospheric Water Harvesting by Large-Scale Radiative Cooling Cellulose-Based Fabric.

Atmospheric water harvesting (AWH) has received tremendous interest because of population growth, limited freshwater resources, and water pollution. However, key challenges remain in developing efficient, flexible, and lightweight AWH materials with scalability. Here, we demonstrated a radiative cooling fabric for AWH via its hierarchically structured cellulose network and hybrid sorption-dewing mechanisms. With 8.3% solar absorption and ∼0.9 infrared (IR) emissivity, the material can drop up to 7.5 °C below ambient temperature without energy consumption via radiative cooling. Water adsorption onto the hydrophilic functional groups of cellulose is dominated by sorption at low relative humidity (RH) and dewing at high RH. The cellulose network provides desirable mechanical properties with entangled high-aspect-ratio fibers over tens of adsorption-extraction cycles. In the field test, the cellulose sample exhibited water uptake of 1.29 kg/kg at 80% RH during the night. The profusion of radiative cooling fabric features desirable cost effectiveness and allows fast deployment into large-scale AWH applications.

Dynamically Tunable All-Weather Daytime Cellulose Aerogel Radiative Supercooler for Energy-Saving Building.

A passive cooling strategy without any electricity input has shown a significant impact on overall energy consumption globally. However, designing tunable daytime radiative cooler to meet requirement of different weather conditions is still a big challenge, especially in hot, humid regions. Here, a novel type of tunable, thermally insulating and compressible cellulose nanocrystal (CNC) aerogel coolers is prepared via chemical cross-linking and unidirectional freeze casting process. Such aerogel coolers can achieve a subambient temperature drop of 9.2 °C under direct sunlight and promisingly reached the reduction of ∼7.4 °C even in hot, moist, and fickle extreme surroundings. The tunable cooling performance can be realized via controlling the compression ratio of shape-malleable aerogel coolers. Furthermore, energy consumption modeling of using such aerogel coolers in buildings in China shows 35.4% reduction of cooling energy. This work can pave the way toward designing high-performance, thermal-regulating materials for energy consumption savings.

Insight into the marine microplastic abundance and distribution in ship cooling systems.

Microplastics (MPs) are becoming widely recognized as one of many global environmental issues. Although recently, it has been suggested that marine plastics may affect a ship's operation, the presence of MPs in a ship's cooling system has not received significant attention. In this study, samples of 40 L each were taken from each of the five main pipes (sea chest (SC), ejector pump (EP), main engine jacket freshwater pump (MJFP), main engine jacket freshwater cooler (MJFC), and expansion tank (ET)) in each season (February, May, July, October 2021) to identify and characterize MPs in the five main pipes of the ship cooling system from the training ship Hanbada, Korea Maritime and Ocean University. As a result of FTIR analysis, the total MP abundance was 24,100 particles/m3 in the cooling system of the ship. MP concentrations were observed to be higher (p < 0.05) in winter and spring (dry season: 1578 ± 604 particles/m3) than in summer and autumn (wet season: 990 ± 390 particles/m3). In addition, the MP concentration in the seawater cooling system (SCS) (1509 ± 553 particle/m3) was slightly higher (p > 0.05) than that in the freshwater cooling system (FCS) (1093 ± 546 particles/m3). Compared to previous studies, it was confirmed that the quantitative amount of MPs on board was similar to or slightly less than the concentration of MPs investigated along the coast of Korea (1736 particles/m3). To identify the chemical composition of MPs, an optical microscope and FTIR analysis was carried out, and PE (polyethylene), PP (polypropylene), and PET (polyethylene terephthalate) were identified as major chemicals in all samples. MPs in the form of fibers and fragments accounted for approximately 95% of the total. This study provided evidence of MP contamination in the main pipe in the cooling system of the ship. These findings confirm that marine MPs existing in seawater may have flowed into the ship's cooling system, and it is necessary to understand the effect of marine MPs on the ship's engine and cooling system through continuous monitoring.

Flexural strength of high yttrium oxide-doped monochrome and multilayered fully stabilized zirconia upon various sintered cooling rates.

PURPOSE: Firing protocols influence the mechanical properties of dental ceramics. This study examined the impact of altering the cooling rate of mono- and multilayered 5 mol% yttria-partially stabilized zirconia (5Y-PSZ) on their strength. MATERIALS AND METHODS: Ninety specimens (width × length × thickness = 10 × 20 × 2 mm) were prepared using 5Y-PSZ monolayer (Mo: Cercon-xt) and 5Y-PSZ multilayered (Mu: Cercon-xt ML) blocks. Randomly distributed specimens were sintered at the recommended firing schedule for three different categories of cooling rates (n = 15/group): slow (S: 5°C/min), normal (N: 35°C/min), and fast (F: 70°C/min). A universal testing machine with four-point bending test was used to measure the flexural strength (σ). The microstructure, fracture characteristics, and chemical composition were evaluated by scanning electron microscope and energy-dispersive spectroscopy. The monoclinic, tetragonal, and cubic phases were investigated using X-ray diffraction. Two-way ANOVA and post hoc Bonferroni comparisons were applied to determine the σ, ( p < 0.05 $p<0.05 $ ), and Weibull analysis was performed to determine the Weibull modulus (m) and characteristic strength (σ0 ). RESULTS: The highest σ and σ0 (MPa) were seen for MuN (454.2 ± 62.0, 480.8 ± 62.9) followed by MuS (453.5 ± 52.6, 476.4 ± 54.3) and MoS (451.5 ± 44.5, 471.2 ± 46.6), whereas MuF had the lowest σ and σ0 (379.8 ± 50.2, 401.6 ± 51.3). The σ value of S-cooling (452.5 ± 47.9) was higher than those for N-cooling (443.4 ± 61.3) and F-cooling (382.3 ± 58.0). The m-value for MoS was the highest (11.4 ± 3.6), whereas that for MoF was the lowest (6.1 ± 1.6). Different cooling rates resulted in a significant difference in σ values (p < 0.05). CONCLUSIONS: S- and N-cooling resulted in significantly higher flexural strength than that obtained by F-cooling. Increasing the cooling rate of 5Y-PSZ resulted in smaller grain size, less grain boundary integration, and higher t- to m-transformation, leading to lower strength. Therefore, a slow and normal cooling rate was recommended to achieve the optimum strength for 5Y-PSZ.

Minimizing thermal damage using self-cooling jaws for radiofrequency intestinal tissue fusion.

INTRODUCTION: Radiofrequency (RF)-induced tissue fusion shows great potential in sealing intestinal tissue without foreign materials. To improve the performance of RF-induced tissue fusion, a novel self-cooling jaw has been designed to minimize thermal damage during the fusion. MATERIAL AND METHODS: The prototype of self-cooling jaws was developed and manufactured. A total number of 60 mucosa-to-mucosa fusions were conducted using ex-vivo porcine intestinal segments with the proposed design and conventional bipolar jaws. The effects of intestinal fusion were evaluated based on temperature curves, burst pressure, thermal damage, and histological appearances. RESULTS: The self-cooling jaws showed significant decrease in temperature during the fusion process. An optimal burst pressure (5.7 ± 0.5 kPa) and thermal damage range (0.9 ± 0.1 mm) were observed when the applied RF power was 100 W. The thermal damage range of the prototype has almost decreased 36% in comparison with the conventional bipolar jaws (1.4 ± 0.1 mm). The histological observation revealed that a decrease of thermal damage was achieved through the application of self-cooling jaws. CONCLUSIONS: The self-cooling jaws were proved to be effective for reducing the thermal damage during RF-induced tissue fusion, which could potentially promote the clinical application of tissue fusion techniques in the future.

Bioinspired Polyacrylamide/(polyvinyl alcohol-copper acetate) Hydrogel with Cooling-Triggered Shape Memory, Color Changing, and Self-Healing Behavior.

Inspired by many living creatures with adjustment of shape and color in an ever-changing environment, color changeable shape memory hydrogels are designed and expected to be potential candidates in the fields spanning from anti-counterfeiting to biomedical devices. However, they normally require complex synthesis, and more importantly, the cooling-induced shape recovery hydrogel is still rare and in its infancy so far. Herein, a unique color changeable shape memory hydrogel by simply incorporating polyvinylalcohol and copper acetate into covalent polyacrylamide network is developed. As core functional element, copper ions serve as reversible crosslinks after heating to achieve excellent cooling-triggered shape memory effect, color shifting and self-healing behavior, showing significant potential in diverse applications like grabbing, information encryption, and biomimetic designs. This work may guide the development of cooling-triggered smart hydrogels for practical applications.

Effect of different dental implant drilling template designs on heat generation during osteotomy - an in vitro study.

OBJECTIVES: This in vitro study examined the effect of different implant drilling template designs on heat generation during osteotomy and on cooling fluid distribution. MATERIAL AND METHODS: Five different template designs were investigated in a standardized setup against a control group and a negative control group: Occlusal-splint-design (OSD), OSD-covering, OSD-lateral opening, Bar design, and Orientation template. Pilot and one consecutive drill were run at 800 rpm with external irrigation and 2-kg load. Thermocouples recorded temperature changes at depths of 3, 6, and 9 mm in a bovine rib model. In the second experimental setup, the drill channel of one rib sample was perforated, and the irrigation volume passing through the drill channel was collected separately over time. RESULTS: Following mean temperature rises occurred [in °C]: control, 4.9; negative control, 12; OSD, 5.6; OSD-covering, 4.7; OSD-lateral opening, 3.8; Bar design, 5.1; and Orientation template, 4.9. The highest temperature increases were found at a drilling depth of 6 mm (p < .006). The 2.2-mm drill resulted in a significantly higher temperature rise than the 2.8-mm drill (p < .001). The mean volume (ml/min) of irrigation through the drill channel was Control group-flow, 28.5; OSD, 4.1; OSD-covering, 2; OSD-lateral opening; 5.8; bar design, 4; and Orientation template, 24.1. CONCLUSION: Within the limitations, it was shown that fully guided drilling templates reduce the amount of cooling liquid at the point of osteotomy. The template design had an influence on the effective volume of the cooling liquid. However, this did not seem to increase the intraosseous temperature significantly.

Analysis of thermocouple-based finger contact temperature measurements.

The understanding of heat conduction during finger contact with cooler or hotter objects is important for designing many electronic devices and for setting safety standards in a variety of occupational settings. In the most common experimental approach to study this process, a micro-thermocouple is placed at the finger-object interface. However, the interpretation of what this measurement corresponds to is not clear. To this end, we develop a three-dimensional thermal simulation of the finger-thermocouple-substrate configuration. The model predictions match finger cooling measurements in eight distinct cases available in prior literature (finger pressed with 1 N or 9.8 N against a steel or an aluminum substrate held at -2 °C or -10 °C). We demonstrate that the thermocouple can be represented accurately as a truncated sphere with emerging cylindrical wires while a multilayer block model of the finger provides similar results to an anatomically representative model. Our simulations show that in the eight previously studied cooling cases, the average surface temperature of skin that is in contact with the substrate follows nearly the same but offset cooling trend as the thermocouple tip temperature. The value of the offset is predominantly determined by the substrate material, with the thermocouple tip temperature being lower than the average skin surface temperature by 1-5 °C and 3-10 °C for steel and aluminum substrate cases, respectively. This temperature difference results in a moderate to an extreme thermocouple underprediction of the time necessary for the skin surface to reach the experimental safety threshold of 1 °C. Consequently, from the perspective of the safety related applications the thermocouple measurement provides a conservative limit on the contact duration and thereby is suitable for such purposes, but for applications requiring accurate skin temperature measurements alternative experimental approaches should be used.

Cellulose-Based Hybrid Structural Material for Radiative Cooling.

Structural materials with excellent mechanical properties are vitally important for architectural application. However, the traditional structural materials with complex manufacturing processes cannot effectively regulate heat flow, causing a large impact on global energy consumption. Here, we processed a high-performance and inexpensive cooling structural material by bottom-up assembling delignified biomass cellulose fiber and inorganic microspheres into a 3D network bulk followed by a hot-pressing process; we constructed a cooling lignocellulosic bulk that exhibits strong mechanical strength more than eight times that of the pure wood fiber bulk and greater specific strength than the majority of structural materials. The cellulose acts as a photonic solar reflector and thermal emitter, enabling a material that can accomplish 24-h continuous cooling with an average dT of 6 and 8 °C during day and night, respectively. Combined with excellent fire-retardant and outdoor antibacterial performance, it will pave the way for the design of high-performance cooling structural materials.

Cats use hollow papillae to wick saliva into fur.

The cat tongue is covered in sharp, rear-facing spines called papillae, the precise function of which is a mystery. In this combined experimental and theoretical study, we use high-speed film, grooming force measurements, and computed tomography (CT) scanning to elucidate the mechanism by which papillae are used to groom fur. We examine the tongues of six species of cats from domestic cat to lion, spanning 30-fold in body weight. The papillae of these cats each feature a hollow cavity at the tip that spontaneously wicks saliva from the mouth and then releases it onto hairs. The unique shape of the cat's papillae may inspire ways to clean complex hairy surfaces. We demonstrate one such application with the tongue-inspired grooming (TIGR) brush, which incorporates 3D-printed cat papillae into a silicone substrate. The TIGR brush experiences lower grooming forces than a normal hairbrush and is easier to clean.

Safety and Feasibility of a Novel Transnasal Cooling Device to Induce Normothermia in Febrile Cerebrovascular Patients.

BACKGROUND: Inducing normothermia with surface cooling temperature modulating devices (TMDs) is cumbersome and often associated with significant shivering. We tested the safety and feasibility of a novel transnasal evaporative cooling device to induce and maintain normothermia in febrile patients following ischemic and hemorrhagic stroke. METHODS: A single-center study utilizing the CoolStat® transnasal cooling device was used to achieve core temperature reduction in mechanically ventilated stroke patients with fever (T ≥ 38.3 C) refractory to acetaminophen by inducing an evaporative cooling energy exchange in the nasal turbinates thru a high flow of dehumidified air into the nasal cavity and out through the mouth. Continuous temperature measurements were obtained from tympanic and core (esophageal or bladder) temperature monitors. Safety assessments included continuous monitoring for hypertension, tachycardia, and raised intracranial pressure (when monitored). Otolaryngology (ENT) evaluations were monitored for any device-related nasal mucosal injury with a pre- and post-visual examination. Shivering was assessed every 30 min using the Bedside Shivering Assessment Scale (BSAS). Duration of device use was limited to 8 h, at which time patients were transitioned to routine care for temperature management. RESULTS: Ten subjects (median age: 54 years, BMI: 32.5 kg/m2, 60% men) were enrolled with normothermia achieved in 90% of subjects. One subject did not achieve normothermia and was later refractory to other TMDs. Median baseline temperature was 38.5 ± 0.1 C, with a reduction noted by 4 h (38.5 ± 0.1 vs 37.3 ± 0.8, P < 0.001) and sustained at 8 h (38.5 ± 0.1 vs 37.1 ± 0.7, P = 0.001). Time to normothermia was 2.6 ± 1.9 h. The median BSAS was 0 (range 0-1) with only 4 episodes necessitating meperidine across 76 h of study monitoring. No treatment was discontinued due to safety concerns. ENT evaluations noted no device-related adverse findings. CONCLUSIONS: Inducing normothermia with a novel transnasal TMD appears to be safe, feasible and not associated with significant shivering. A multicenter trial testing the ability of the CoolStat to maintain normothermia for 24 h is currently underway.

The elderly's physiological and perceptual responses to cooling during simulated activities of daily living in UK summer climatic conditions.

OBJECTIVES: The elderly are the most at-risk population for heat-related illness and mortality during the periods of hot weather. However, evidence-based elderly-specific cooling strategies to prevent heat-illness are limited. The aim of this investigation was to quantify the elderly's physiological and perceptual responses to cooling through cold water ingestion (COLD) or an L-menthol mouth rinse (MENT) during simulated activities of daily living in UK summer climatic conditions. STUDY DESIGN: Randomised, controlled repeated measures research design. METHODS: A total of ten participants (men n = 7, women n = 3: age; 69 ± 3 yrs, height; 168 ± 10 cm, body mass; 68.88 ± 13.72 kg) completed one preliminary and three experimental trials; control (CON), COLD and MENT. Experimental trials consisted of 40 min rest followed by 30 min of cycling exercise at 6 metabolic equivalents and a 6-min walk test (6MWT), within a 35 °C, 50% relative humidity environment. Experimental interventions (every 10 min); cold water (4 °C) ingestion (total of 1.5L) or menthol (5 ml mouth swill for 5 s, menthol concentration of 0.01%). RESULTS: Peak rectal temperature (Tre) was significantly (P < 0.05) lower in COLD compared with CON (-0.34 ± 0.16 °C) and MENT (-0.36 ± 0.20 °C). End exercise heart rate (HR) decreased in COLD compared with CON (-7 ± 9 b min-1) and MENT (-6 ± 7 b min-1). There was no difference in end exercise thermal sensation (TS) (CON; 6.1 ± 0.4, COLD; 6.0 ± 0.4, MENT; 6.4 ± 0.6) or thermal comfort (TC) (CON; 4 ± 1, COLD; 4 ± 1, MENT; 4 ± 1) between trials. The participants walked significantly further during the COLD 6MWT compared with CON (40 m ± 40 m) and MENT (40 m ± 30 m). There was reduced physiological strain in the COLD 6MWT compared with CON (Tre; -0.21 ± 0.24 °C, HR; -7 ± 8 b min-1) and MENT (Tre; -0.23 ± 0.24 °C, HR; -4 ± 7 b min-1). CONCLUSION: The elderly have reduced physiological strain (Tre and HR) during activities of daily living and a 6MWT in hot UK climatic conditions, when they drink cold water. Furthermore, the elderly's perception (TS and TC) of the hot environment did not differ from CON at the end of exercise with COLD or MENT interventions. Menthol provided neither perceptual benefit to exercise in the heat nor functional gain. The TS data indicate that elderly may be at increased risk of heat illness, due to not feeling hot and uncomfortable enough to implement physiological strain reducing strategies such as cold-water ingestion.

Bamboo grid versus polyvinyl chloride as packing material in cooling tower: Energy efficiency and environmental impact assessment.

As an abundant and fast-growing biomass, bamboo can be used as construction materials owing to its desirable physical and mechanical properties, environmentally friendly features, and alternative to replace toxic and hazardous wastes in industrial processing. In this study, grid material made from bamboo (termed 'bamboo grid') was developed and compared to commercially used polyvinyl chloride (PVC) as packing material in cooling towers; PVC packing has drawbacks such as fouling, deposit buildup, low durability, and is harmful to environments. The cooling capacity, energy efficiency and environmental impact of bamboo grid packing were evaluated via life cycle assessment (LCA), particularly the cumulative energy demand (CED) and the Building for Environmental and Economic Sustainability (BEES). Although the thermal performance of the PVC packing was found higher than that of the bamboo grid packing, the bamboo grid packing showed improved resistance characteristic, recording a total saving of 529.2 tons of standard coal during a six-month field test in a real thermal power generation plant. LCA results revealed that the utilization of bamboo-grid packing to replace PVC packing in cooling towers reduced total CED from 3420 MJ to 561 MJ per functional unit, achieving 6 times reduction. A desirable reduction ranging from 1.5 to 10.5 times was also recorded for the BEES indices. This LCA comparison analysis confirmed the improvement of energy efficiency and reduction of environmental impact by using the bamboo grid to replace PVC as packing material in cooling towers. The major environmental impact (BEES) indices (e.g., the total Global warming potential, Acidification, Eutrophication and Smog) were reduced by 1.5-10.5 times via the use of bamboo grid. The results demonstrate that bamboo grid packing is a good alternative to replace existing grid packing materials such as concrete and PVC that are harmful to human health and environments.

Effect of Three Different Cooling and Insulation Techniques on Pulp Chamber Temperature during Direct Temporization with Polymethyl methacrylate-based Resin.

AIM AND OBJECTIVE: This in vitro study evaluates and compares the changes in pulp chamber temperature during direct fabrication of provisional restorations in maxillary central incisors after using three different cooling techniques. MATERIALS AND METHODS: Total of 60 samples of maxillary central incisors along with their putty indices were divided into four groups (one control and three experimental) and were prepared using a surveyor cum milling machine. Teeth were sectioned 2 mm below cementoenamel junction and a K-type thermocouple wire was inserted in the tooth and secured at the pulpal roof using amalgam. Putty index filled with DPI tooth molding resin material [polymethyl methacrylate (PMMA)] was placed on the tooth and temperature changes per 5 seconds were recorded by temperature indicating device for the control, on-off, precooled putty, and dentin bonding agent (DBA) group. RESULTS: The highest mean obtained was of the control (11.04°C), followed by DBA group (9.53°C), precooled putty group (6.67°C), and on-off group (1.94°C). Precooled putty index group took maximum time to reach the baseline temperature (847.5 seconds). CONCLUSION: On-off technique is the most effective method to reduce the intrapulpal temperature during polymerization, as compared to the other techniques used in the study. Retardation in the polymerization process was seen in precooled putty group, which may make this technique clinically inadvisable. CLINICAL SIGNIFICANCE: Thermal protection of pulp must always be considered during direct fabrication of provisional restoration when a PMMA-based resin is used. By using on-off technique, not only the thermal insult to the pulp can be effectively minimized but also the harmful effects of residual monomer (poor marginal fit and pulpal irritation) can be eliminated.