Temperature Probe Research Articles

Heating efficiency of agarose samples doped with magnetic nanoparticles subjected to ultrasonic and magnetic field

Recently, magneto-ultrasound heating of tissue in the presence of magnetic nanoparticles (NPs) has been studied due to its high potential for use in oncological hyperthermia. It has been published that a synergistic effect, generation of additional heat caused by magneto-ultrasonic coupling, was observed in a tissue-mimicking material (TMM) enriched with magnetic NPs. The specific absorption rate (SAR) was determined from the temperature rise measurements in a focus of the ultrasound beam. It is important to use precise measurement methods when considering medical applications, for which there are limitations to the power of each field, resulting from the prevention of biological phenomena dangerous to the patient. This study demonstrates that in magneto-ultrasonic heating SAR can be measured much more accurately if the ultrasonic field is almost uniform. Measurements were performed on TMM containing Fe3O4 NPs with a diameter of approximately 8 nm and superparamagnetic properties. Both, the measurement and simulation results showed that the errors resulting from the inaccuracy of placing the temperature probe are smaller than in the case of the focused ultrasound. At the same time, the temperature increase caused by the ultrasonic field is almost linear and the influence of heat convection on the SAR determination is negligible. The measurements showed that magneto-ultrasonic hyperthermia can provide the desired thermal effect at lower ultrasound powers and magnetic fields compared to ultrasonic or magnetic hyperthermia used alone. No synergy effect was recorded.

Evaluation and Correction of PurpleAir Temperature and Relative Humidity Measurements

The PurpleAir PA-II sensor provides low-cost in situ measurements of meteorological variables including temperature and relative humidity (RH), as well as fine particulate matter (PM2.5) in real time. The sensors have been used in several studies investigating intracity differences in temperature and PM2.5. While the adoption and use of low-cost sensors has many benefits, care must be taken to ensure proper calibration and testing. This is true not only for PM2.5 measurements but also for temperature and RH given the synergistic health impacts from extreme heat and air pollution exposure. Here, we compare continuous temperature and RH measurements from a PA-II sensor to measurements from a Campbell Scientific 107 temperature probe and Vaisala HMP45C RH probe. All three instruments were co-located from December 2021 to June 2023 in Asheville, North Carolina. We found that the PA-II has an overall high temperature bias of 2.6 °C and root mean square error (RMSE) of 2.8 °C. Applying a linear regression correction reduces RMSE to 1.0 °C, while applying the constant 4.4 °C correction suggested by PurpleAir reduces RMSE to only 2.2 °C. Our PA-II RH measurements have a low bias of −17.4% and uncorrected RMSE of 18.5%. A linear regression correction improves the RH RMSE to 4.5%. Applying the constant 4% RH correction suggested by PurpleAir reduces RMSE to only 14.8%. We present new correction factors that differ from those suggested by PurpleAir, which overcorrect the high temperature bias and undercorrect the low RH bias. We also show that our correction factors improve estimates of dewpoint temperature (RMSE of 0.6 °C and 0.9 °C) compared to the corrections suggested by PurpleAir.

Characterization of Plastic Scintillator Detector for In Vivo Dosimetry in Gynecologic Brachytherapy.

(1) Background: High dose gradients and manual steps in brachytherapy treatment procedures can lead to dose errors which make the use of in vivo dosimetry (IVD) highly recommended for verifying brachytherapy treatments. A new procedure was presented to obtain a calibration factor which allows fast and robust calibration of plastic scintillation detector (PSD) probes for the geometry of a compact phantom using Monte Carlo simulations. Additionally, characterization of PSD energy, angular, and temperature dependences was performed. (2) Methods: PENELOPE/PenEasy code was used to obtain the calibration factor. To characterize the energy dependence of the PSD, the signal was measured at different radial and transversal distances. The sensitivity to the angular position was characterized in axial and azimuthal planes. (3) Results: The calibration factor obtained allows for an absorbed dose to water determination in full scatter conditions from ionization measured in a mini polymethylmethacrylate (PMMA) phantom. The energy dependence of the PSD along the radial distances obtained was (2.3 ± 2.1)% (k = 1). The azimuthal angular dependence measured was (2.6 ± 3.4)% (k = 1). The PSD response decreased by (0.19 ± 0.02)%/°C with increasing detector probe temperature. (4) Conclusions: The energy, angular, and temperature dependence of a PSD is compatible with IVD.

Comparison of effect of inhaled anaesthetic (Sevoflurane) versus intravenous (Propofol) anaesthetic on core and peripheral body temperature during general anaesthesia: A randomised control study

: The fall in core body temperature and peripheral body temperature following the administration of anaesthetic agent has been studied and demonstrated so far, along with the comparison of the same parameters following induction with propofol in contrast to that with sevoflurane. But no study so far, has compared the effects of TCI-propofol based anaesthesia with that of sevoflurane based anaesthesia for induction and maintenance, on core and peripheral body temperature and the gradient of temperature between the agents. The studies conducted so far, has shown more fall in core and peripheral body temperature from their respective baseline values when propofol was used for induction of anaesthesia in comparison to the use of sevoflurane. A total of 60 adults were randomized into two groups of 30 each; Group 1 were induced with TCI- propofol at 8mcg/ml plasma concentration and maintaind with TCI-propofol at 2-3mcg/ml plasma concentration and 66% nitrous oxide and 33% oxygen gas mixture. Group 2 were induced with intravenous thiopentone at 3-5mg/kg body weight and maintained with 1-1.5MAC sevoflurane, 66% nitrous oxide and 33% oxygen gas mixture. Core body temperature was measured inserting the temperature probe into nasophraynx and peripheral temperature was measured with the temperature probe inserted onto thenar eminence of either hand. We observed that both anaesthetic agents have caused similar fall in core temperature. However, peripheral temperature fell more with sevoflurane compared to TCI-propofol. In parallel with these observations, the increase in temperature gradient was higher in magnitude for sevoflurane based anaesthesia. The core temperature was comparable between the groups from their respective baseline values. But, the fall in peripheral temperature was more in sevoflurane group, so was the temperature gradient. Thus, TCI-propofol when used in appropriate plasma concentration for induction and maintenance of anaesthesia causes less hypothermia in contrast to sevoflurane.

Comparison of temperature and renal tissue thermal damage by holmium laser with different energy parameters during lithotripsy: in vitro porcine kidney model.

Holmium laser percutaneous nephrolithotripsy was simulated by porcine kidney calculus model in vitro to investigate thermal damage of renal tissue by different energy parameters of the holmium laser. We placed human kidney calculus specimen in fresh vitro porcine kidney, then insert thermocouple temperature probes into the submucosa of the renal pelvis and reheated in a 37°C water bath. A percutaneous nephrological sheath was used to penetrate the renal parenchyma with a moderate irrigation rate of 30ml/min at 18℃. The Holmium laser was used to fragment the stones under a nephroscope, and the temperature was recorded. The four independent models were lithotripsy with 30W and 60W laser for 5 and 10min, respectively; the mean temperature of 30W vs. 60W within 5min was 36.06°C vs. 39.21°C (t = 5.36, P < 0.01) and the highest temperature was 43.60°C vs. 46.60°C; the mean temperature of 30W vs. 60W within 10min was 37.91°C vs. 40.13℃ (t = 5.28, P < 0.01), maximum temperature 46.80℃ vs. 49.20℃. Pathologically, each kidney was observed to have different degrees of thermal damage lesions, and the higher power and longer time the more severe the injury, but the injury was mainly limited to the uroepithelial and subepithelial tissues, with rare damage to renal tubules. The higher laser excitation power and longer duration raised the intrarenal temperature significantly and caused a certain degree of thermal damage to the kidney tissue, but overall it was found to be safe and reliable. Urologists can avoid further side effects through surgical expertise.

Development and Testing of a Rocket-Based Sensor for Atmospheric Sensing Using an Unmanned Aerial System.

Measurements of the vertical structure of the lower atmosphere are important to the understanding of air quality. Unmanned Aerial Systems (UASs, drones) can provide low cost, repeatable measurements of the temperature, pressure, and relative humidity. A set of inexpensive sensors controlled with an Arduino microprocessor board were tested on a UAS against a meteorology grade sensor. Two modes of operation for sampling were tested: a forward moving sampler and a vertical ascent sampler. A small particle sensor (Sensiron SPS30) was integrated and was capable of retrieving vertical aerosol distributions during an inversion event. The thermocouple-based temperature probe and the relative humidity measurement on the Bosch BME280 sensor correlated well with the meteorological sensor. The temperature and relative humidity sensors were then deployed on a rocket sounding platform. The rocket sounding system performed well up to a height of 400 m. The inexpensive sensors were found to perform adequately for low-cost development and uses in education and research.

Temperature probe placement in very preterm infants during delivery room stabilization: an open-label randomized trial

BackgroundVariation in practice exists for temperature probe positioning during stabilization of very preterm infants (<32 weeks gestation). We explored the influence of temperature probe sites on thermoregulation.MethodsAn open-label, stratified, balanced, parallel, randomized trial was conducted. Inborn infants were randomly assigned temperature probe to the axilla or to the upper back. The primary outcome was normothermia (local range: 36.8–37.3 °C and World Health Organization (WHO) range: 36.5–37.5 °C) at admission to the neonatal intensive care unit.ResultsBetween 1 November 2018 and 4 July 2022, 178 infants were randomly assigned to one of the two sites (n = 89 each), 175 included in the final analysis. Normothermia (local range) was achieved for 39/87 infants (44.8%) assigned to the upper back compared to 28/88 infants (31.8%) assigned to the axilla [risk difference:13%; 95% CI −1.3–27.3]. Normothermia (WHO range) was achieved for 78/87 infants (89.7%) assigned to the upper back compared to 70/88 infants (79.6%) assigned to the axilla [risk difference:10.1%; 95% CI −0.5–20.7]. No infant recorded temperatures >38 °C or developed skin injury.ConclusionsIn very preterm infants, upper back site was equally effective as the axilla in maintaining normothermia, with no increase in adverse events.Clinical trial registrationThe study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12620000293965).ImpactSubstantial variation in practice exists for the site of securing a temperature probe during delivery room stabilization of very preterm infants and the influence of temperature probe site on thermoregulation remains unknown.In this study, upper back site was equally effective as the axilla in maintaining normothermia, with no increase in adverse events.Clinicians could adopt upper back site for maintaining normothermia.This study may contribute data to future international participant data prospective meta analysis of randomized controlled trials worldwide on temperature probe positioning in very preterm infants, increasing translation of research findings to optimize thermoregulation and clinical outcomes.

Preclinical assessment of a noncooled MR thermometry-based neurosurgical laser therapy system.

MRI-guided laser interstitial thermal therapy (MRgLITT) has recently gained interest as an ablative stereotactic procedure for intractable epilepsy, movement disorders, and brain tumors. Conventionally, a LITT system consists of a laser generator and cooled laser applicator, which is a fiber optic core surrounded by a sheath through which cooled fluid is pumped. However, this footprint can make the system bulky and nonmobile, limit the maximum depth of targeting, and increase the chances of breakdown. Herein, the authors conduct a preclinical assessment of a noncooled MRgLITT system in a porcine model. Three-tesla MRI was used to guide the in vivo placement of noncooled laser applicators in the porcine brain. The study consisted of a survival arm and terminal arm. The laser was activated at a power of 4-7 W for ≤ 180 seconds. Temperature changes were monitored using the MR thermometry software ThermoGuide in the survival arm (n = 5) or both ThermoGuide software and adjacently inserted thermal probes in the terminal arm (n = 3). Thermal damage was determined by the software using the temperature-time relationship of cumulative equivalent minutes at 43°C (CEM43). Temperatures calculated by the software were compared with those recorded by the temperature probes. The dimensions of thermal damage thresholds (TDTs; 2-9, 10-59, 60-239, ≥ 240 CEM43 isolines) given by MR thermometry were compared with the dimensions of irreversible damage on histopathological analysis. There was a strong correlation between temperature recordings by ThermoGuide and those by thermal probes at both 4 mm (r = 0.96) and 8 mm (r = 0.80), with a mean absolute error of 0.76°C ± 2.13°C and 0.17°C ± 1.65°C at 4 and 8 mm, respectively. The area of 2-9 CEM43 was larger than the area of irreversible damage seen on histopathological analysis. The dimensions of the 10 and 60 CEM43 correlated well with dimensions of the lesion on histopathological analysis. A well-defined border (≤ 1 mm) was observed between the area of irreversible damage and healthy brain tissue. This preclinical assessment showed that the noncooled LITT system was able to precisely reach the target and create well-defined lesions within a margin of safety, without any adverse effects. MR thermometry software provided an accurate near-real-time temperature of the brain tissue, and dimensions of the lesion as visualized by the software correlated well with histopathological findings. Further studies to test the system's efficacy and safety in human subjects are in progress.

An MR-compatible fiber-optic probe for measuring focused ultrasound-induced temperature rises without viscous heating artifacts

Focused ultrasound (FUS) beam interactions with thermocouples and fiber optic (FO) probes cause a “viscous heating artifact” (VHA), which prevent accurate temperature measurements during acoustic sonication. This work demonstrates a novel fiber-optic temperature probe which is insensitive to VHA, validated in an MR-guided FUS treatment setting. The FO probe (OSENSA Innovations; PRB-140, 0.14 mm diameter) was inserted with an 18G catheter into a tissue-mimicking gelatin phantom. The FO probe tip was located with high-resolution MR images (0.25 × 0.25 × 0.5 mm3) for targeting with FUS. Continuous-wave FUS sonications (50 W, 20 s) were delivered at a distance of ∼1.5 mm from the FO probe tip using a 256 phased-array transducer (Imasonic, France; 1 MHz, 2.1 × 2.3 × 9.8 FWHM spot size) and FUS-induced heating was measured with 3D MR temperature imaging (MRTI; 0.5 × 0.5 × 1 mm3 resolution, 3.9 s acquisition). The VHA effect was not observed in the PRB-140 FO probe measurement data. The FO probe heating and cooling curves closely matched those measured by MRTI, with a root mean-squared error (RMSE) of 0.61 °C. In contrast, the RMSE of VHA-sensitive FO probe was 6.00 °C for a similar acoustic power output. This ultrasound artifact-immune FO temperature probe is highly advantageous for MR temperature sequence development and precise temperature monitoring in FUS treatment applications.

A Simple and Cost-Effective Technique to Monitor the Sublimation Flow During Primary Drying of Freeze-Drying Using Shelf Inlet/Outlet Temperature Difference or Chamber to Condenser Pressure Drop

As lyophilization continues to be a critical step in the manufacturing of sensitive biopharmaceuticals, challenges often arise during the scale up to commercial scale or the transfer from one manufacturing site to another. While data from the small-scale development of the lyophilization cycle is abundant it is typically much more difficult to extract important information from commercial scale cycles, due to the lack of process analytical technologies available on the commercial line. There is often a reluctance to include wireless temperature or pressure probes during GMP operations due to the additional contamination risk, and retrofitting equipment such as the TDLAS can be prohibitively expensive. Further, as products become more advanced, the cost of consuming the product or even the availability of material may limit the opportunities to run commercial scale trials. This paper presents two novel methods to garner critical cycle information to allow for the evaluation of cycle performance without the need for expensive analytical equipment, costly revalidation and line downtime. Critically, this can be achieved using commonly available temperature and capacitance probes on existing commercial scale equipment. The first method is a calorimetric method, based on quantifying the differences in heat transfer liquid temperature between the shelf inlet and shelf outlet. This change in temperature results from the on-going sublimation, an endo-thermic reaction occurring during lyophilization. The second method uses the differential pressure between the chamber and condenser resulting from the vapor flow from vial to condenser during primary drying. As stated by the authors both methods align well and provide valuable cycle characterization data.

Towards Experimental Confirmation of Quarkonia Melting in Quark–Gluon Plasma: A Review of Recent Measurements of Quarkonia Production in Relativistic Heavy-Ion Collisions

The dissociation, or “melting”, of heavy quarkonia states due to color charge screening is a predicted signature of quark–gluon plasma (QGP) formation, with a quarkonium state predicted to dissociate when the temperature of the medium is higher than the binding energy of the quarkonium state. A conclusive experimental observation of quarkonium melting coupled with a detailed theoretical understanding of the melting mechanism would enable the use of quarkonia states as temperature probes of the QGP, a long-sought goal in the field of relativistic heavy-ion collisions. However, the interpretation of quarkonia suppression measurements in heavy-ion collisions is complicated by numerous other cold nuclear matter effects that also result in the dissociation of bound quarkonia states. A comprehensive understanding of these cold nuclear matter effects is therefore needed in order to correctly interpret quarkonia production measurements in heavy-ion collisions and to observe the melting of quarkonium states experimentally. In this review, recent measurements of quarkonia production in pA and AA collisions and their state-of-the-art theoretical interpretations will be discussed, as well as the future measurements needed to further the knowledge of cold nuclear matter effects and realize a measurement of quarkonia melting in heavy-ion collisions.

Workplace induced heat-related-illness and kidney disorders among coal cutters of underground mines

Workers in hot underground coal mines could develop heat-related illnesses, (especially skin, digestion and kidney problems), as compared to workers in non-hot mines. This study found severity of this situation by comparing heat illness symptoms, core body and skin temperature and kidney malfunctioning amongst workers of both types of mines. Ingestible thermometric pills (sending readings to Sensor Electronic Module every 15 s), skin temperature probes (connected to various body parts and sending readings to loggers) and laboratory analysis of pre- and post-shift samples of blood and urine, US-NIOSH-HETA-2012 sheet to survey symptoms, were used to collect data from 50 workers (25 from five hot mines (G1) and 25 from five non-hot mines (G2)). Two mine groups showed significant differences ( p-value &lt;.001) regarding wet-bulb globe temperature, dry-bulb temperature and relative humidity. The highest core body temperature was 38.8°C in G1 and 37.9°C in G2. In intra-group comparison for kidney functioning, post-shift samples showed haematocrit (%) was reduced to 43.6 ± 2.1 from 45.4 ± 1.4 in G1 and to 44.0 ± 2.9 from 45.0 ± 0.75 in G2, and estimated glomerular filtration rate was reduced from 100 ± 19 to 94 ± 0 mL/min/1.72 m2 in G1 and to 113 ± 15 from 115 ± 19a in G2 workers. The comparison showed hot mines could induce heat-related illnesses which would necessitate intervention to reduce exposure.

Temperature monitoring in levees for detection of seepage

Improving knowledge of existing levees through investigation and monitoring is an important step in evaluating their safety and that of the surrounding area. Nevertheless, these activities are complex due to the considerable levee length and the high spatial variability of soil composing the body and foundation, especially when paleo-rivers are present. In order to investigate the reliability of new advanced techniques proposed for characterizing the soil stratigraphy and the seepage condition within the levee foundation, a new test site was realized along the Adige River in Bolzano Province (Italy). Here, five boreholes, drilled in a 20-m-side square area straddling the embankment, host four different types of monitoring equipment, among which some are Distributed Fiber Optical Sensors (DFOS), here used for detecting the temperature variations along the well. The present paper focuses on the critical analysis of the preliminary results obtained with DFOS and their comparison with data obtained using traditional pressure and temperature probes. The monitoring data collected in the field during the passage of a flood that occurred on 5th August 2021 are used to better understand the hydraulic behavior and the safety conditions of the levee but also to fully assess the reliability and potential of DFOS.

Autonomous execution of highly reactive chemical transformations in the Schlenkputer

We design a modular programmable inert-atmosphere Schlenkputer (Schlenk-line computer) for the synthesis and manipulation of highly reactive compounds, including those that are air and moisture sensitive or pyrophoric. Here, to do this, we constructed a programmable Schlenk line using the Chemputer architecture for the inertization of glassware that can achieve a vacuum line pressure of 1.5 × 10−3 mbar, and integrated a range of automated Schlenk glassware for the handling, storage and isolation of reactive compounds at sub-ppm levels of O2 and H2O. This has enabled automation of a range of common organometallic reaction types for the synthesis of four highly reactive compounds: [Cp2TiIII(MeCN)2]+, CeIII{N(SiMe3)2}3, B(C6F5)3 and {DippNacNacMgI}2, which are variously sensitive to temperature, pressure, water and oxygen. Automated crystallization, filtration and sublimation are demonstrated, along with analysis using inline nuclear magnetic resonance or reaction sampling for ultraviolet–visible spectroscopy. Finally, we demonstrate low-temperature reactivity down to −90 °C as well as safe handling and quenching of alkali metal reagents using dynamic feedback from an in situ temperature probe.

A solid-state high harmonic generation spectrometer with cryogenic cooling.

Solid-state high harmonic generation (sHHG) spectroscopy is a promising technique for studying electronic structure, symmetry, and dynamics in condensed matter systems. Here, we report on the implementation of an advanced sHHG spectrometer based on a vacuum chamber and closed-cycle helium cryostat. Using an in situ temperature probe, it is demonstrated that the sample interaction region retains cryogenic temperature during the application of high-intensity femtosecond laser pulses that generate high harmonics. The presented implementation opens the door for temperature-dependent sHHG measurements down to a few Kelvin, which makes sHHG spectroscopy a new tool for studying phases of matter that emerge at low temperatures, which is particularly interesting for highly correlated materials.

Experimental and Numerical Assessment of the Thermal Bridging Effect in a Reinforced Concrete Corner Pillar

This paper discusses experimental and simulated data regarding the thermal bridging effect in a reinforced concrete corner pillar, which belongs to a building dating back to the 1980s and located in Southern Italy. The thermal field determined by the concrete pillar corner has been evaluated, introducing an experimental procedure based on both direct measurements and indirect observations of the inner superficial temperature by means of thermal imaging techniques and surface temperature probes. Moreover, indoor and outdoor air temperature and relative humidity were measured to provide suitable boundary conditions in the numerical simulations, performed with a commercial software tool widely used in Italy based on 2D finite element techniques. The experimental measurements show that, at more than 50 cm from the corner, the surface temperatures become almost constant, meaning that the thermal bridging effect becomes less evident. However, the surface temperature in the corner is around 1.5 °C lower than in the undisturbed flanking walls. In terms of local heat flux, the discrepancy between simulations and measurements is below 3%. Finally, this paper verifies the effectiveness of External Thermal Insulation Composite System (ETICS) renovation in reducing the thermal bridging effect of the corner pillar. The results also include the calculation of the linear thermal transmittance with a series of relations available in well-known atlases for thermal bridges and show that these relations are more reliable in the case of uninsulated pillar than for the insulated one.

Nanoscale Cathodoluminescence Thermometry with a Lanthanide-Doped Heavy-Metal Oxide in Transmission Electron Microscopy.

When navigated by the available energy of a system, often provided in the form of heat, physical processes or chemical reactions fleet on a free-energy landscape, thus changing the structure. In in situ transmission electron microscopy (TEM), where material structures are measured and manipulated inside the microscope while being subjected to external stimuli such as electrical fields, laser irradiation, or mechanical stress, it is necessary to precisely determine the local temperature of the specimen to provide a comprehensive understanding of material behavior and to establish the relationship among energy, structure, and properties at the nanoscale. Here, we propose using cathodoluminescence (CL) spectroscopy in TEM for in situ measurement of the local temperature. Gadolinium oxide particles doped with emissive europium ions present an opportunity to utilize them as a temperature probe in CL measurements via a ratiometric approach. We show the thermometric performance of the probe and demonstrate a precision of ±5 K in the temperature range from 113 to 323 K with the spatial resolution limited by the size of the particles, which surpasses other methods for temperature determination. With the CL-based thermometry, we further demonstrate measuring local temperature under laser irradiation.

Intrinsic dual emissive insulin capped Au/Ag nanoclusters as single ratiometric nanoprobe for reversible detection of pH and temperature and cell imaging

pH and temperature are two important characteristics in cells and the environment. These, not only in the well-done regulation of cell functions but also in diagnosis and treatment, have a key role. Protein-protected bimetallic nanoclusters are abundantly used in the building of biosensors. However, insulin-stabilized Au–Ag nanoclusters with dual intrinsic emission have not been investigated yet. In this work, Dual emissive insulin templated Au–Ag nanocluster (Ins(Au/Ag)NCs) were first synthesized in a simple and green one-put manner. The two emission wavelengths of, as-prepared NCs centered at 410 and 630 nm, excited in one excitation wavelength (330 nm). These two emission peaks were assigned to the di-Tyrosine cross-linked formation and bimetallic nanoclusters respectively. Further analysis displayed that each emission band of Ins(Au/Ag)NCs responded to one variable whilst another peak remained constant; For blue and red emission wavelengths, pH dependency and thermo-responsibility were observed respectively. As-prepared nanoprobe with the intrinsic dual emissive feature was used for ratiometric determination of these parameters, each with a discrete response from another. The linear range of 6.0–9.0 for pH and 1 to 71 °C for temperature was obtained, which comprises the physiological range of pH and temperature and afforded intracellular sensing and imaging capability. As-prepared NCs probe show excellent biocompatibility and cell membrane permeability, and so were successfully applied as direct ratiometric pH and temperature probes in HeLa and HFF cells. More interestingly, this dual emissive nanoprobe is capable of distinguishing cancer cells from normal ones.

Supraglottic Airway Devices: Present State and Outlook for 2050.

Correct placement of supraglottic airway devices (SGDs) is crucial for patient safety and of prime concern of anesthesiologists who want to provide effective and efficient airway management to their patients undergoing surgery or procedures requiring anesthesia care. In the majority of cases, blind insertion of SGDs results in less-than-optimal anatomical and functional positioning of the airway devices. Malpositioning can cause clinical malfunction and result in interference with gas exchange, loss-of-airway, gastric inflation, and aspiration of gastric contents. A close match is needed between the shape and profile of SGDs and the laryngeal inlet. An adequate first seal (with the respiratory tract) and a good fit at the second seal of the distal cuff and the gastrointestinal tract are most desirable. Vision-guided insertion techniques are ideal and should be the way forward. This article recommends the use of third-generation vision-incorporated-video SGDs, which allow for direct visualization of the insertion process, corrective maneuvers, and, when necessary, insertion of a nasogastric tube (NGT) and/or endotracheal tube (ETT) intubation. A videoscope embedded within the SGD allows a visual check of the glottis opening and position of the epiglottis. This design affords the benefit of confirming and/or correcting a SGD's position in the midline and rotation in the sagittal plane. The first clinically available video laryngeal mask airways (VLMAs) and multiple prototypes are being tested and used in anesthesia. Existing VLMAs are still not perfect, and further improvements are recommended. Additional modifications in multicamera technology, to obtain a panoramic view of the SGD sitting correctly in the hypopharynx and to prove that correct sizes have been used, are in the process of production. Ultimately, any device inserted orally-SGD, ETT, NGT, temperature probe, transesophageal scope, neural integrity monitor (NIM) tubes-could benefit from correct vision-guided positioning. VLMAs also allow for automatic recording, which can be documented in clinical records of patients, and could be valuable during teaching and research, with potential value in case of legal defence (with an airway incident). If difficulties occur with the airway, documentation in the patient's file may help future anesthesiologists to better understand the real-time problems. Both manufacturers and designers of SGDs may learn from optimally positioned SGDs to improve the design of these airway devices.

Achieving Cochlear Therapeutic Hypothermia through Irrigation of the Mastoid and Tympanic Cavities

Introduction: Mild therapeutic hypothermia (MTH) is an exciting nonpharmaceutical otoprotection strategy. In this study, we applied simple irrigation of the tympanic and mastoid cavities to understand the timing of both achieving MTH and recovery back to euthermic temperatures for application in the clinical setting. Methods: Three human temporal bones were used in this study in the temporal bone laboratory. A standard mastoidectomy was performed on each followed by the insertion of temperature probes into the basal turn of the cochlea via a middle cranial fossa approach. The temporal bones were warmed in heated bead baths to 37°C. The tympanic and mastoid cavities were then irrigated with room temperature water, and intracochlear temperature readings were recorded every minute. After 15 min, irrigation was stopped, and temperature readings were collected until temporal bones returned to euthermic levels. Results: Intracochlear MTH was achieved within the first minute of irrigating the tympanic and mastoid cavities. Intracochlear temperatures plateaued after 5 min around 30°C. Discontinuation of irrigation resulted in the temperature rising logarithmically above the MTH levels after 9–10 min. Conclusion: Intracochlear MTH can be achieved via irrigation of the tympanic and mastoid cavities with room temperature irrigation within 60 s. After irrigation for 5 min, hypothermic temperatures will remain therapeutic for 10 min following cessation of irrigation.