Recurrent malignant hyperthermia after scoliosis correction surgery

Malignant hyperthermia(MH)is a genetic disorder of skeletal muscle cells that affects muscle cytoplasmic calcium homeostasis,with high mortality and low morbidity.Generally,it presents with non-specific signs of a hypermetabolic response,including high fever,tachycardia,and elevated end-tidal carbon dioxide(ETCO_(2)).The successful treatment lies in the timely recognition and early use of dantrolene.[1]As an inhibitor of Ca2+release through ryanodine receptor(RYR)channels,the skeletal muscle relaxant dantrolene has proven to be both a valuable experimental probe of intracellular Ca2+signaling and a lifesaving treatment for MH.[2]Dominant mutations in the skeletal muscle RYR1 gene are well-recognized causes of both malignant hyperthermia susceptibility(MHS)and central core disease(CCD).

Structural, Magnetic and Heating Efficiency of Ball Milled γ-Fe2O3/Gd2O3 Nanocomposite for Magnetic Hyperthermia

The preparation of γ-Fe2O3/Gd2O3 nanocomposite for possible use in magnetic hyperthermia application was done by ball milling technique. The nanocomposite was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The heating efficiency and the effect of milling time (5 h and 30 h) on the structural and magnetic properties of the nanocomposite were reported. XRD analysis confirms the formation of the nanocomposite, while magnetization measurements show that the milled sample present hysteresis with low coercivity and remanence. The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of the milling time. A mean heating efficiency of 68 W/g and 28.7 W/g are obtained for 5 h and 30 h milling times respectively at 332 kHz and 170 Oe. The results showed that the obtained nanocomposite for 5 h milling time is a promising candidate for magnetic hyperthermia due to his properties which show an interesting magnetic behavior and high specific absorption rate.

Extraction method of nanoparticles concentration distribution from magnetic particle image and its application in thermal damage of magnetic hyperthermia

Magnetic particle imaging(MPI)technology can generate a real-time magnetic nanoparticle(MNP)distribution image for biological tissues,and its use can overcome the limitations imposed in magnetic hyperthermia treatments by the unpredictable MNP distribution after the intratumoral injection of nanofluid.However,the MNP concentration distribution is generally difficult to be extracted from MPI images.This study proposes an approach to extract the corresponding concentration value of each pixel from an MPI image by a least squares method(LSM),which is then translated as MNP concentration distribution by an interpolation function.The resulting MPI-based concentration distribution is used to evaluate the treatment effect and the results are compared with the ones of two baseline cases under the same dose:uniform distribution and MPI-based distribution considering diffusion.Additionally,the treatment effect for all these cases is affected by the blood perfusion rate,which is also investigated deeply in this study.The results demonstrate that the proposed method can be used to effectively reconstruct the concentration distribution from MPI images,and that the weighted LSM considering a quartic polynomial for interpolation provides the best results with respect to other cases considered.Furthermore,the results show that the uniformity of MNP distribution has a positive correlation with both therapeutic temperature distribution and thermal damage degree for the same dose and a critical power dissipation value in the MNPs.The MNPs uniformity inside biological tissue can be improved by the diffusion behavior after the nanofluid injection,which can ultimately reflect as an improvement of treatment effect.In addition,the blood perfusion rate considering local temperature can have a positive effect on the treatment compared to the case which considers a constant value during magnetic hyperthermia.

Magnetite Nanoparticles Coated with Synthetic Polymer for Hyperthermia Application: Review

Hyperthermia treatment using appropriate magnetic materials in an alternating magnetic field to generate heat has been proposed as a low-invasive cancer treatment method. Magnetite iron oxide nanoparticles (Fe3O4) are expected to be an appropriate type of magnetic material for this purpose due to its biocompatibility. Several polymers are used to Fe3O4 MNPs to avoid or decrease agglomeration, and in most cases increase dispersion stability. In this review, we will give briefly how these coated magnetite nanoparticles (PMNPs) are synthesized in the first part. The main characterization techniques usually used to study the properties of these MNPs are prseneted in the second part. Finally, most recent results on the heating ability of polymeric coated magnetite nanoparticles (PMNPs) are given in the last part of this review.

Hyperthermia combined with chemotherapy vs chemotherapy in patients with advanced pancreatic cancer:A multicenter retrospective observational comparative study

BACKGROUND Several studies report the useful therapeutic results of regional hyperthermia in association with chemotherapy(CHT) and radiotherapy for the treatment of pancreatic cancer. Modulated electrohyperthermia(mEHT) is a new hyperthermia technique that induces immunogenic death or apoptosis of pancreatic cancer cells in laboratory experiments and increases tumor response rate and survival in pancreatic cancer patients, offering beneficial therapeutic effects against this severe type of cancer.AIM To assess survival, tumor response and toxicity of mEHT alone or combined with CHT compared with CHT for the treatment of locally advanced or metastatic pancreatic cancer.METHODS This was a retrospective data collection on patients affected by locally advanced or metastatic pancreatic cancer(stage Ⅲ and IV) performed in 9 Italian centers, members of International Clinical Hyperthermia Society-Italian Network. This study included 217 patients, 128(59%) of them were treated with CHT(no-mEHT) and 89(41%) patients received mEHT alone or in association with CHT. mEHT treatments were performed applying a power of 60-150 watts for 40-90 min, simultaneously or within 72 h of administration of CHT.RESULTS Median patients’ age was 67 years(range 31-92 years). mEHT group had a median overall survival greater than non-mEHT group(20 mo, range 1.6-24, vs 9 mo, range 0.4-56.25, P < 0.001). mEHT group showed a higher number of partial responses(45% vs 24%, P = 0.0018) and a lower number of progressions(4% vs 31%, P < 0.001) than the no-mEHT group, at the three months follow-up. Adverse events were observed as mild skin burns in 2.6% of mEHT sessions.CONCLUSION mEHT seems safe and has beneficial effects on survival and tumor response of stage Ⅲ-IV pancreatic tumor treatment. Further randomized studies are warranted to confirm or not these results.

Malignant hyperthermia as a rare complication of local lidocaine injection:A case report

BACKGROUND Malignant hyperthermia(MH)is a hypermetabolic disorder of skeletal muscles triggered by exposure to volatile anesthetics and depolarizing muscular relaxants.It manifests with clinical presentations such as tachycardia,muscle rigidity,hyperpyrexia,and rhabdomyolysis in genetically predisposed individuals with ryanodine receptor or calcium voltage-gated channel subunit alpha1 S mutations.Local anesthetics,such as lidocaine,are generally considered safe;however,complications can arise,albeit rarely.Lidocaine administration has been reported to induce hypermetabolic reactions resembling MH in susceptible individuals.The exact mechanism by which lidocaine might trigger MH is not fully understood.Although some mechanisms are postulated,further research is needed for a better understanding of this.CASE SUMMARY We present the case of MH in a 43-year-old male patient with an unknown genetic predisposition following a lidocaine injection during a dental procedure.This case serves as a reminder that while the occurrence of lidocaine-induced MH is rare,lidocaine can still trigger this life-threatening condition.Therefore,caution should be exercised when administering lidocaine to individuals who may be susceptible to MH.It is important to note that prompt intervention played a crucial role in managing the patient’s symptoms.Upon recognizing the early signs of MH,aggressive measures were initiated,including vigorous intravenous normal saline administration and lorazepam.Due to the effectiveness of these interventions,the administration of dantrolene sodium,a specific antidote for MH,was deferred.CONCLUSION This case highlighted the significance of vigilant monitoring and swift action in mitigating the detrimental effects of lidocaine-induced MH.Caution should be exercised when administering lidocaine to individuals who may be predisposed to MH.It is very important to be aware and vigilant of the signs and symptoms of MH as early recognition and treatment intervention are important to prevent serious complications to decrease mortality.

Bioelectromagnetic Paradigm of Cancer Treatment—Modulated Electro-Hyperthermia (mEHT)

One of the most frequently applied bioelectromagnetic effects is the deep heating of the living species with EMF energy. Despite its long history, hyperthermia is a rarely applied oncotherapy. The reason is its controversial results and complicated control. One of the solutions is concentrating the electromagnetic energy nanoscopically on the parts of the malignant cells instead of heating up the complete tumor-mass. This approach is a kind of non-uniform energy absorption, providing energy liberation only in the selected regions. The energy-absorption of the malignant cells targets the membranes and creates a situation far from thermal equilibrium. The selection of the malignant cells is based on their decided differences from their healthy counterparts. The distinguishing parameters are the electromagnetic properties of the components of the malignant tissue which are the physiologic differences between the malignant cells and their healthy counterparts. The targets realize nano-range heating, using natural nanoclusters on the cell-membrane without artificially implementing them. This energy absorption generates consequent reactions, like programmed cell-death (apoptosis) continued by immunogenic cell-death involving extended immune reactions.? The applied radiofrequency current is amplitude modulated by time-fractal modulation pattern. The accurately matched impedance realizes the self-selective mechanisms which are promoted by stochastic resonances. This complex method is a new kind of hyperthermia, named mEHT. Our objective is to analyze the problems of the selective, non-equilibrium energy absorption, and present a solution by the electromagnetic mechanisms for an effective and controllable hyperthermia in oncology.

Intraperitoneal perfusion of cytokine-induced killer cells with local hyperthermia for advanced hepatocellular carcinoma

AIM:To study the effect and tolerance of intraperitoneal perfusion of cytokine-induced killer(CIK) cells in combination with local radio frequency(RF) hyperthermia in patients with advanced primary hepatocellular carcinoma(HCC).METHODS:Patients with advanced primary HCC were included in this study.CIK cells were perfused intraperitoneal twice a week,using 3.2 × 10 9 to 3.6 × 10 9 cells each session.Local RF hyperthermia was performed 2 h after intraperitoneal perfusion.Following an interval of one month,the next course of treatment was administered.Patients received treatment until disease progression.Tumor size,immune indices(CD3 +,CD4 +,CD3 + CD8 +,CD3 + CD56 +),alpha-fetoprotein(AFP) level,abdominal circumference and adverse events were recorded.Time to progression and overall survival(OS) were calculated.RESULTS:From June 2010 to July 2011,31 patients diagnosed with advanced primary HCC received intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia in our study.Patients received an average of 4.2 ± 0.6 treatment courses(range,1-8 courses).Patients were followed up for 8.3 ± 0.7 mo(range,2-12 mo).Following combination treatment,CD4 +,CD3 + CD8 + and CD3 + CD56 + cells increased from 35.78% ± 3.51%,24.61% ± 4.19% and 5.94% ± 0.87% to 45.83% ± 2.48%(P = 0.016),39.67% ± 3.38%(P = 0.008) and 10.72% ± 0.67%(P = 0.001),respectively.AFP decreased from 167.67 ± 22.44 to 99.89 ± 22.05 ng/mL(P = 0.001) and abdominal circumference decreased from 97.50 ± 3.45 cm to 87.17 ± 4.40 cm(P = 0.002).The disease control rate was 67.7%.The most common adverse events were low fever and slight abdominal erubescence,which resolved without treatment.The median time to progression was 6.1 mo.The 3-,6-and 9-mo and 1-year survival rates were 93.5%,77.4%,41.9% and 17.4%,respectively.The median OS was 8.5 mo.CONCLUSION:Intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia is safe,can efficiently improve immunological status,and may prolong survival in HCC patients.

Narrow line between benefit and harm: Additivity of hyperthermia to cisplatin cytotoxicity in different gastrointestinal cancer cells

AIM To investigate the response to hyperthermia and chemotherapy, analyzing apoptosis, cytotoxicity, and cisplatin concentration in different digestive system cancer cells.METHODS AGS(gastric cancer cell line), Caco-2(colon cancer cell line) and T3M4(pancreatic cancer cell line) were treated by cisplatin and different temperature setting(37 ℃ to 45 ℃) either in isolation, or in combination. Treatment lasted for one hour. 48 h after the treatment viability was evaluated by MTT, cell apoptosis by Annexin V-PE and 7 ADD flow cytometry. Intracellular cisplatin concentration was measured immediately after the treatment, using mass spectrometry. Isobologram analysis was performed to evaluate the mathematical combined effect of temperature and cisplatin.RESULTS AGS cells were the most sensitive to isolated application of hyperthermia. Hyperthermia, in addition to cisplatin treatment, did not provoke a synergistic effect at intervals from 37 ℃ to 41 ℃ in neither cancer cell line. However, a temperature of 43 ℃ enhanced cisplatin cytotoxicity for Caco-2 cells. Moreover, isobologram analysis revealed mathematical antagonistic effects of cisplatin and temperature combined treatment in AGS cells; variations between synergistic, additive, and antagonistic effects in Caco-2 cells; and additive and antagonistic effects in T3 M4 cells. Combined treatment enhanced initiation of cell apoptosis in AGS, Caco-2, and T3 M4 cells by 61%, 20%, and 19% respectively. The increase of intracellular cisplatin concentration was observed at 43 ℃ by 30%, 20%, and 18% in AGS, Caco-2, and T3 M4 cells, respectively.CONCLUSION In addition to cisplatin, hyperthermia up to 43 ℃ does not affect the viability of cancer cells in a synergistic manner.

Inductive heat property of Fe_3O_4 nanoparticles in AC magnetic field for local hyperthermia

Magnetite (Fe3O4) nanoparticles with different magnetic properties were prepared by coprecipitation of Fe3+ and Fe2+ with aqueous NaOH solution. The inductive heat properties of Fe3O4 nanoparticles in an alternating current (AC) magnetic field were investigated for local hyperthermia. The maximum saturation magnetization Ms of Fe3O4 nanoparticles is 65.53 emu·g-1 under the optimum conditions of Fe3+: Fe2+ molar ratio at 1.8:1. The Ms of Fe3O4 nanoparticles decreased as the Fe3+/Fe2+ molar ratio increased. But the coercivity Hc increases with the increasing of Fe3+/Fe2+ molar ratio. Exposed in the AC magnetic field for 29 min, the temperatures of physiological saline suspension containing Fe3O4 nanoparticles were 42-97.5 ℃. The inductive heat property of Fe3O4 nanoparticles in AC magnetic field decreases as Hc increases, but increases with the increasing of Ms. The Fe3O4 nanoparticles would be useful as good thermoseeds for localized hyperthermia treatment of cancers.

Expression change of TNF-αin myocardium and hepatic tissue of rats with compound stress of hyperthermia and Hpopolysaccharide

Objective:To investigate the expression characteristics of TNF-αin myocardium and hepatic tissue of rats with compound stress of hyperthermia and lipopoiysaccharide(LPS).Methods: Male SPF Wistar rats were randomly divided into room temperature+physiological saline group (Croup C),hyperthermia+physiological saline group(Croup II),room temperature+LPS group(Croup L) and hyperthermia+LPS group(Croup HL).The rats were put in simulated climate cabin.Croup HL and Croup H were exposed in the environment at a dry bulb temperature(TDB) of(35.0±0.5)℃,while Croup L and Croup C were exposed in the environment at a TDB of(26.0±0.5)℃. The rats in Croup HL and Croup L were given tail intravenous injection of LPS 10 mg/kg,while the rats in Croup H and Croup C were given tail intravenous injection of 9 g/L NaCl 10 ml/kg. After the stress,immunohistochemical SABC staining method was used to detect the expression characteristics of TNF-αin myocardium and hepatic tissue of rats,and those rats were given routine pathological examinations.Results:The expression of TNF-αin myocardium and hepatic tissue in Croup HL was enhanced remarkably,and the tissue damages of Croup HL were severest.Conclusions:The eardiotoxieity and hepatotoxicity caused by compound stress of hyperthermia and LPS is closely related to the expression of TNF-α.

Heating Preciosity—Trends in Modern Oncological Hyperthermia

The use of hyperthermia as a treatment in oncology is a common topic for debate. Some researchers expect a breakthrough in oncological treatments with hyperthermia, whereas others have disregarded the method. Serious questions concerning hyperthermia have arisen. Should homogeneous (isothermal) or heterogeneous (selective) heating being used? When we use selective heating (heterogeneity), should the entire tumour be targeted or should the malignant cells be individually selected? Does the mechanism involve thermal cell death or thermally-assisted cell death? Is the goal necrosis or apoptosis? Is hyperthermia safe as a monotherapy or does it have to be combined with conventional treatments? When the selection is local, how do we act on disseminated cells that represent a high risk of life threatening metastases? When local heating is the focus, how should it be carried out with measured and controlled? Our objective is to show how precise, selective heat transfer is necessary to remove malignant cells and, consequently, how hyperthermia as part of the immune-oncology can change the game in this promising field of oncological therapies.

Why Labor Epidural Causes Fever and Why Lidocaine Burns on Injection? Role of TRPV 1 Receptor in Hyperthermia: Possible Explanation of Mechanism of Hyperthermia during Labor Epidural and Burning Sensation on Injection of Local Anesthetics

The mechanisms of epidural-associated fever remain incompletely understood [1-3]. We propose that action of local anesthetic on TPRV1. The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor can explain this effect and explain mechanism of burning sensation on local anesthetic injected subcutaneously or intramuscular. Role of TRPV1 receptor was not discussed previously in Obstetric Anesthesia literature. Based on available data, we propose that Local Anesthetics work as agonist/antagonist on TPRV1 receptors. Antagonist action may cause hyperthermia through modifying thermoregulation [4], agonist action may cause hyperthermia thru release of IL-6 and other mediators of inflammation [5-10]. Agonist action may explain burning sensation on injection of Local Anesthetics. Burning sensation can be diminished by increasing pH of Local Anesthetic solution, because vanillin receptors are stimulated by acidification through lower pH [11,12].

Uncontrolled central hyperthermia by standard dose of bromocriptine:A case report

BACKGROUND Some patients present to the intensive care unit due to noninfectious pathologies resulting in fever,especially acute neurological injuries,including brain trauma and intracranial haemorrhage.The cause has been identified to be central hyperthermia characterized by a high core temperature and a poor response to antipyretics and antibiotics.However,no proper guidelines on how to treat central hyperthermia have been developed for clinical practice.CASE SUMMARY A 63-year-old woman was transferred to our hospital due to injury after a traffic accident.Eight hours after admission,her pupils enlarged bilaterally from 2.5 mm to 4.0 mm.She developed severe coma and underwent decompressive craniectomy.She was diagnosed with central hyperthermia after surgery and was prescribed bromocriptine.The standard dose of bromocriptine could not control her hyperpyrexia,and we prescribed 30 mg a day to control her temperature.CONCLUSION Bromocriptine may be effective in controlling central hyperthermia and have a dosage effect.

Usefulness of Magnetic Particle Imaging for Predicting the Therapeutic Effect of Magnetic Hyperthermia

Purpose: To investigate the usefulness of magnetic particle imaging (MPI) for predicting the therapeutic effect of magnetic hyperthermia (MH). Materials and Methods: First, we performed phantom experiments to investigate the relationship between the MPI value and the temperature rise of magnetic nanoparticles (MNPs) under an alternating magnetic field (AMF). The MPI value was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. Samples filled with various iron concentrations of MNPs (Resovist&reg;) were prepared and were imaged using our MPI scanner. These samples were also heated using the AMF, and the specific loss power (SLP) and volume-specific loss power (vSLP) were calculated from the initial slope of the time-dependent temperature rise. Second, we performed animal experiments using tumor-bearing mice, which were divided into untreated (n = 10) and treated groups (n = 20). The tumors in the treated group were injected with Resovist&reg;?at an iron concentration of 250 mM (n = 10) or 500 mM (n = 10), and received MH for 20 min, during which the temperatures in the tumor and rectum were measured. The relative tumor volume growth (RTVG) was calculated from (V15 -?V0)/V0, where V0 and V15 represented the tumor volume on day 0 and day 15 after MH, respectively. Results: In phantom experiments, the MPI value had significant correlations with the iron concentration of MNPs (r = 0.997), temperature rise (r = 0.981), and vSLP (r = 0.961). In animal experiments, the MPI value had significant correlations with the temperature rise in the tumor (r = 0.731) and RTVG (r = ﹣0.687). Conclusion: Our preliminary results suggest that MPI is useful for predicting the therapeutic effect of MH.

Hyperthermia on skin immune system and its application in the treatment of HPV-infected skin diseases

In this paper, the effects of hyperthermia on cells and immune system are introduced briefly. The mechanism of action of hyperthermia on human papilloma virus （HPV）-infected skin diseases was elaborated as an example in this paper. Many studies have proved that hyperthermia affects a number of cellular and molecu- lar constitutes in the skin immune system, involving both innate and adaptive immune responses; the efficacy of hyperthermia in treating some infectious and cancerous conditions has been validated and applied in clinics, while molecular mechanisms of hyperthermia affecting the immunereaction is still unclear.

Bromocriptine in Central Hyperthermia after Severe Traumatic Brain Injury

Strong evidence showed that fever after traumatic brain injury TBI is associated with increased mortality. In this study, we tried to evaluate the role of Bromocriptine in central hyperthermia in patients with severe TBI. This prospective controlled study was conducted on 50 severe TBI patients who admitted to the critical care department and confirmed on Computed Tomography (CT) of the brain and GCS of less than 9 at admission. Then, they were randomly assigned into 2 groups. Bromocriptine group (25) received bromocriptine 7.5 mg/day during 24 hours from admission through a naso-gastric (NG) feeding tube. Control group (25) received conventional treatment only. Temperature was measured every 2 hours. The antipyretic measures used were the same across all patients enrolled. The primary outcome was number of patients diagnosed with central hyperthermia. After the discharge of all patients, there was a statistically significant difference between the 2 groups in number of patients diagnosed with central hyperthermia (6 (24%) in bromocriptine group Vs 18 (72%) in control, p = 0.002). There were no differences in hospital length of stay (p = 0.904) or mortality (p = 0.393). Early administration of bromocriptine in severe TBI may be associated with lower incidence of central hyperthermia with no effect on length of stay or mortality.

Energy Absorption by the Membrane Rafts in the Modulated Electro-Hyperthermia (mEHT)

Aim: Heating by nanoparticles, which are located in the tissue to be treated, is a well-recognized method in hyperthermic oncology. Our objective is to investigate selective, nanoscopic heating without concentrating extra artificial nanoparticles. We have in silico calculation to study the heating of the transmembrane protein clusters (rafts) on cell-membrane. The transmembrane protein domains have significantly higher dielectric constant than their lipid neighborhood in the membrane. This difference causes a local gradient in the Specific Absorption Rate (SAR), which could be a factor of heating of the membranes locally, as well as exciting the receptors for various signal transduction in the cells. We suppose that this process determines the observed cellular effects of modulated electro-hyperthermia (mEHT, trade-name: oncothermia). Materials and Methods: In silico models with highly specialized software (Computer Simulation Technology (CST), Darmstadt, Germany) were performed visualizing the selectivity for the membrane domains. Local raft models were created to simulate the electromagnetic (EM) effect of a 13.56 MHz excitation between two perfect electrical conductor plates, simulating the equipotential conditions of the sides of the membrane in the vicinity of the raft. The simulations were performed with near-field (EQS) solver of CST. The electric field, current density, and electric loss density were monitored by the simulations. The applied material properties and parameters refer to the recent literature. Results: In silico models show ten times higher energy-absorption of the transmembrane domains than that of its lipid-membrane surrounding, and intra- and extracellular neighborhood. Depending on the size, orientation, and location of the membrane rafts, the value of SAR varies, but we use only two simplified models to see the absorption properties. Taking into account the characteristics of the EM field effects we showed that the selective energy-absorption increased further by the cell-cell interactions. The model-calculation could confirm the opportunity of the local membrane heating. Conclusion: Our results indicate the heating in nanoscopic range with energy-absorption by the transmembrane proteins. The heated protein-clusters (membrane rafts) are used the same way as the artificial nanoparticles, while these absorbers are natural parts of the biological system.

Individual Differences in Cognitive Performance Regulated by Deep-Brain Activity during Mild Passive Hyperthermia and Neck Cooling

Hyperthermia-induced decline in cognitive performance is a moderate complication that poses challenges to the maintenance of safety. Although the underlying mechanism can be attributed to the disruption of brain networks, the propensity remains unclear. This study aimed to test the hypothesis that the extent of the alterations in cognitive performance is governed by the activity of deep brain structures, including monoaminergic neural systems. A decline in cognitive performance during mild hyperthermia and the beneficial effects of neck cooling were demonstrated using the Continuous Performance Test as a battery of cognitive tasks. Aspects of cognitive performance were characterized using the deep-brain activity (DBA) index as a neural activity parameter and the State-Trait Anxiety Inventory to assess the extent of alterations in cognitive performance as an individual measure. It was found that a higher average DBA index during tasks is essential for high cognitive performance in the heat. This beneficial effect of DBA is governed by the upper brainstem. This DBA benefit is more significant for individuals with higher average DBA indices at rest in a normal environment. Individual differences in cognitive performance in the heat are governed by differences in DBA. In addition, the beneficial effect of DBA on cognitive performance in heat only applies under conditions including neck cooling. This limited neck-cooling effect is attributed to anti-homeostatic thermoregulatory responses to cognitive tasks regulated by DBA.

Magnetometry and Hyperthermia Study of Magnetic Fluid Preparation UNIMAG

We investigated the hyperthermal and magnetic properties of the stable magnetic suspension of magnetite nanoparticles. With this purpose in mind, we designed a low-frequency oscillator, 300 W, 300 KHz. A sample of the magnetic suspension was placed in the induction coil and heated up to 55°C for 30 minutes. Based on the results of measurements of transverse susceptibility, we can infer that the suspension was superparamagnetic at room temperature and transformed into the magnetic state at nitrogen temperature. Comparing the obtained experimental results with the literature data, we assessed the mean size of nanoparticles, which made up about 10 nm. Computer simulation assessment on the basis of magnetization curve gives close results.