Optimal Temperature Regulation Research Articles

Ex vivo Optimization of Glucose-Regulated Protein 94/Glycoprotein 96 Expressions in Mammospheres; Implication for Breast Cancer Immunotherapy.

Objective The induction of immunity against cancer stem cells (CSCs) can boost the efficiency of cancer vaccines. Heat shock proteins (HSPs) are required for the successful activation of anti-tumor immune responses. Glycoprotein 96 (gp96) is a well-known HSP that promotes the cross-presentation of tumor antigens. The aim of the present study was to optimize the temperature for induction of gp96 in grade 3 breast cancer spheres. Materials and Methods In the experimental study, CSCs were enriched from breast tumor tissue samples and cultured in DMEM-F12 with epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), B27, and bovine serum albumin (BSA) for 22 days. The expression level of CD24 and CD44 as CSC markers was measured by flow cytometry in secondary mammospheres, and the expression of NANOG, SOX2, and OCT4 genes in CSCs was also analyzed using the real-time polymerase chain reaction (PCR). To find the optimal temperature regulation of gp96, the mammosphere was incubated at different temperatures for 1 hour, and gp96 expression was measured using the western blotting assay. Results Primary mammospheres were obtained after seven days of culture, and secondary spheres formed 22 days after passage. Flow cytometry analysis showed that cells with CD24-CD44+phenotype were enriched in the culture period (from 2.6% on day 1 to 32.6% on day 22). Real-time PCR indicated that OCT4, NANOG, and SOX2 expression in mammospheres were increased by 3.8 ± 0.6, 17.8 ± 0.6, and 7.7 ± 0.8 fold respectively in comparison to the MCF-7 cell line. Western blot analysis showed that gp96 production was significantly upregulated when mammospheres were incubated at both 42°C and 43°C in comparison to the control group. ConclusionAltogether, we found that heat-induced upregulated expression of gp96 in CSCs enriched mammospheres from breast tumor tissue might be used as a complementary procedure to generate more immunogenic antigens in immunotherapy settings.

Optimal Temperature Regulation of Integrated Circuits with Peltier Heat Pumps

A thermal network will be presented to model a multi-layer structure consisting of a semiconductor structure, integrated Peltier heat pump and a cooling fin. A criterion will be set up to determine the optimal Peltier current to minimise the chip temperature using the power dissipation as the control parameter. Compared with classical methods, the proposed solution does not show any time delays in response to power changes and is not sensitive to the position of chip temperature sensors. It does not generate chip temperature oscillations. The idea can be applied in each integrated circuit cooled with Peltier heat pumps, e.g., power devices, high-performance processors, high-frequency integrated circuits, etc. The authors present a simple mathematical formula that can be easily implemented in the software of a processor being cooled. As a consequence, the device is able to operate with maximum efficiency assuming required reliability. Theoretical considerations are illustrated by some results of computations. The paper is addressed to designers involved in the creation of devices dissipating a significant amount of heat energy.

Optimal Thermal Regulation of a Real Data Centre

Abstract This paper presents a pilot method for optimal temperature regulation of real data centre rooms. The development is a part of a wider research activity conducted for EU FP7 project GENiC (Globally optimized Energy efficient data Centres). An overall description of the concept and GENiC platform is presented with emphasis on the thermal control system development including its architecture, design, online-algorithms and real system implementation on a real data centre facility. Latest experimental results of the developed control platform are presented, illustrating the capabilities and efficiency of the proposed technical approach towards optimal thermal control of data centres.

Hierarchical and distributed demand response control strategy for thermostatically controlled appliances in smart grid

Thermostatically controlled appliances (TCAs) have great thermal storage capability and are therefore excellent demand response (DR) resources to solve the problem of power fluctuation caused by renewable energy. Traditional centralized management is affected by communication quality severely and thus usually has poor real-time control performance. To tackle this problem, a hierarchical and distributed control strategy for TCAs is established. In the proposed control strategy, target assignment has the feature of self-regulating, owing to the designed target assignment and compensating algorithm which can utilize DR resources maximally in the controlled regions and get better control effects. Besides, the model prediction strategy and customers’ responsive behavior model are integrated into the original optimal temperature regulation (OTR-O), and OTR-O will be evolved into improved optimal temperature regulation. A series of case studies have been given to demonstrate the control effectiveness of the proposed control strategy.

A Communication Performance Evaluation on Smoothing Power Fluctuations Based on Demand Response Control of Thermostatically-controlled Appliances

Cyber security problem in energy system has been paid more and more attention recently. In this paper, impact of the packet loss and bit errors in the communication process on the performance of demand response was evaluated. Thermodynamic modelling mechanism of the typical electric heat pumps was first discussed. And, a novel heat pump demand response control strategy based on Optimal Temperature Regulation (OTR) was proposed. The control strategy was then applied to balance the power fluctuations caused by renewable energy. Packet loss and bit errors in the signal transmission were discussed, and their impact on the performance of the control strategy was analysed. Finally, case studies were used to validate the given method.

Biothermal Model of Patient and Automatic Control System of Brain Temperature for Brain Hypothermia Treatment

Various surface-cooling apparatus such as the cooling cap, muffler and blankets have been commonly used for the cooling of the brain to provide hypothermic neuro-protection for patients of hypoxic-ischemic encephalopathy. The present paper is aimed at the brain temperature regulation from the viewpoint of automatic system control, in order to help clinicians decide an optimal temperature of the cooling fluid provided for these three types of apparatus. At first, a biothermal model characterized by dynamic ambient temperatures is constructed for adult patient, especially on account of the clinical practice of hypothermia and anesthesia in the brain hypothermia treatment. Secondly, the model is represented by the state equation as a lumped parameter linear dynamic system. The biothermal model is justified from their various responses corresponding to clinical phenomena and treatment. Finally, the optimal regulator is tentatively designed to give clinicians some suggestions on the optimal temperature regulation of the patient ’s brain. It suggests the patient ’s brain temperature could be optimally controlled to follow-up the temperature process prescribed by the clinicians. This study benefits us a great clinical possibility for the automatic hypothermia treatment.

On homeostasis in daisyworld

The steady state solution of the Daisyworld modelof Watson and Lovelock (1983) is examined in detail. Focus is on the two-daisy state, which exhibits homeostasis overa large range of solar luminosities. The analytical approach usedmakes clear the dependence of the steady state and the size of thedomain over which it exists on the various parameters of the system as well as the mechanism for its attractivity.It is shown that the self-regulatory effect of the biota is basedon a priori specifying a relation between the equilibrium effectivetemperature T eq e and the equilibrium effective albedoA eq e. This relation originates first, from the assumption that the local temperature contrast between the black and white daisies is given by the local albedo contrast, and second, from the requirement that the equilibrium expansion rates of the black and white daisies are equal.The regulation is found to work best when the local albedo contrast is large and when the system is capable of redistributing heatin an efficient manner. It is shown that the attractivity of the steady stateis due to the temperature-dependence of the expansion rate of thedaisies, i.e., the close-coupling between climate and the biota. Some aspects of the Daisymodel seem fairly realistic, such as the conditions for optimal temperature regulation. On the other hand, the basic assumptions of the modelgive rise to local temperatures (of the regions of black daisies, white daisies and uncovered ground) which are independent of the incoming radiation.This property of fixed local temperatures and the associatedheat transport mechanism itself do not seem to have parallels in the real Earth system.

Rehydration strategies--balancing substrate, fluid, and electrolyte provision.

The combination of heat stress, dehydration, and exercise imposes perhaps the most-severe physiological challenge for the human body short of disease or serious bleeding. Exercise in the heat requires the body to attempt to cope simultaneously with competing demands for cardiovascular homeostasis, thermoregulatory control, and maintenance of muscle energetics. When dehydration is superimposed upon this scenario (as is often the case during most forms of exercise), the results can be catastrophic for both health and performance. Fluid replacement reduces the risk of heat illness and improves exercise performance by preventing or reducing dehydration and by providing a convenient means of ingesting carbohydrate. The fact that even low levels of dehydration (e.g., equivalent to a 2% loss of body weight) impair cardiovascular and thermoregulatory response, and reduces the capacity for exercise, is beyond scientific dispute. For these reasons, optimal performance is possible only when dehydration is minimized by ingesting ample volumes of fluid during exercise. Recent research has demonstrated that consuming fluid in direct proportion to sweat loss (or close to it) maintains important physiological functions and significantly improves exercise performance, even during exercise lasting only one hour. Preventing dehydration enables the cardiovascular system to maintain blood pressure and cardiac output, thereby sustaining the increase in skin blood flow and sweating that are essential for optimal temperature regulation. Remaining well hydrated during exercise also preserves muscle function, reducing the reliance on muscle glycogen as a fuel source. Carbohydrate ingestion also improves exercise performance, an effect that is independent of and additive to preventing dehydration. The practical application of this knowledge requires that athletes follow a more-aggressive fluid-replacement regimen than is now usually the case. Successful implementation of this regimen requires that coaches, athletes, and support personnel are made aware of the practical benefits of adequate fluid replacement, that appropriate fluid-replacement strategies are developed and implemented, and that athletes have the opportunity to train themselves to ingest larger volumes of fluid more frequently. Success during competition in warm weather is more likely for those athletes who are highly fit and well acclimatized to training and competing in the heat, and who diligently avoid even low levels of dehydration. The competitive advantage will definitely shift in favor of those athletes whose coaches and trainers recognize the fundamental value of fitness, acclimation, and hydration, coupled with other strategies for keeping athletes cooled and fueled.