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PubMed1991

[Determinations by indirect calorimetry need not be expensive and technically complicated. A new measurement system and its validation].

Presentation of a newly conceived measuring instrument to determine the energy expenditure of critically ill patients at the bedside by means of indirect calorimetry. The special advantages of the measuring instruments are easy handling, little maintenance and very low working expenses and prime costs. The accuracy of measurement is considerable nd is comparable with that of other measuring methods, as has been established by an extensive validation.

Calorimetry, Indirect↗
PubMed2002

The enthalpy of the alanine peptide helix measured by isothermal titration calorimetry using metal-binding to induce helix formation.

The goal of this study is to use the model system described earlier to make direct measurements of the enthalpy of helix formation at different temperatures. For this we studied model alanine peptides in which helix formation can be triggered by metal (La(3+)) binding. The heat of La(3+) interaction with the peptides at different temperatures is measured by isothermal titration calorimetry. Circular dichroism spectroscopy is used to follow helix formation. Peptides of increasing length (12-, 16-, and 19-aa residues) that contain a La(3+)-binding loop followed by helices of increasing length, are used to separate the heat of metal binding from the enthalpy of helix formation. We demonstrate that (i) the enthalpy of helix formation is -0.9 +/- 0.1 kcal/mol; (ii) the enthalpy of helix formation is independent of the peptide length; (iii) the enthalpy of helix formation does not depend significantly on temperature in the range from 5 to 45 degrees C, suggesting that the heat capacity change on helix formation is very small. Thus, the use of metal binding to induce helix formation has an enormous potential for measuring various thermodynamic properties of alpha-helices.

Alanine↗
PubMed2004

Mapping glycoside hydrolase substrate subsites by isothermal titration calorimetry.

Relating thermodynamic parameters to structural and biochemical data allows a better understanding of substrate binding and its contribution to catalysis. The analysis of the binding of carbohydrates to proteins or enzymes is a special challenge because of the multiple interactions and forces involved. Isothermal titration calorimetry (ITC) provides a direct measure of binding enthalpy (DeltaHa) and allows the determination of the binding constant (free energy), entropy, and stoichiometry. In this study, we used ITC to elucidate the binding thermodynamics of xylosaccharides for two xylanases of family 10 isolated from Geobacillus stearothermophilus T-6. The change in the heat capacity of binding (DeltaCp = DeltaH/DeltaT) for xylosaccharides differing in one sugar unit was determined by using ITC measurements at different temperatures. Because hydrophobic stacking interactions are associated with negative DeltaCp, the data allow us to predict the substrate binding preference in the binding subsites based on the crystal structure of the enzyme. The proposed positional binding preference was consistent with mutants lacking aromatic binding residues at different subsites and was also supported by tryptophan fluorescence analysis.

Binding Sites↗
PubMed2000

Thermodynamic characterization of the interaction between TRAF2 and tumor necrosis factor receptor peptides by isothermal titration calorimetry.

The tumor necrosis factor receptor (TNFR) superfamily can induce diverse biological effects, including cell survival, proliferation, differentiation, and apoptosis. The major signal transducers for TNFRs are the family of TNF receptor associated factors (TRAFs). The direct interaction between TRAFs and the intracellular tails of TNFRs is the first step of this signal relay process. Structural studies have revealed a trimeric nature of TRAF2 and a symmetrical mode of receptor binding, suggesting the involvement of trivalent TNFR2-receptor interaction in the signal transduction. In this study, using isothermal titration calorimetry (ITC), we report thermodynamic characterization of the interaction between TRAF2 and monomeric peptide sequences from TNFR members, including TNFR2, CD40, CD30, Ox40, and 4-1BB, and the Epstein-Barr virus (EBV)-transforming protein, latent infection membrane protein-1 (LMP1). The dissociation constants of the interaction were shown to range between 40 microM and 1.9 mM, which are substantially weaker than most protein-peptide interactions. The interaction is entirely driven by exothermic enthalpy, consistent with the abundance of polar contacts. The enthalpy of the interaction has a significant temperature dependence (DeltaCp = -245 cal/mol small middle dotK). The unfavorable entropy in the interaction and the comparison with structural energetics calculations suggest the involvement of conformational rearrangement in the interaction. The low affinity of TRAF2 to monomeric receptor peptides further supports the importance of avidity contribution in TRAF2 recruitment by these receptors upon ligand-induced trimerization or higher order oligomerization.

Amino Acid Sequence↗
PubMed1976

Investigation of phase transitions of lipids and lipid mixtures by sensitivity differential scanning calorimetry.

High sensitivity differential scanning calorimetry is applied to the study of the thermotropic behavior of mixtures of synthetic phospholipids in multilamellar aqueous suspensions. The systems dimyristoylphosphatidylcholine dipalmitoylphosphatidylcholine, and dimyristoylphosphatidylethanolamine-distearoylphosphatidylcholine, although definitely nonideal, exhibit essentially complete miscibility in both gel and liquid crystalline states, while the system dilauroylphosphatidylcholine-distearoylphosphatidylcholine is monotectic with lateral phase separation in the gel state. Comparison of the observed transition curves with theoretical curves calculated from the calorimetrically determined phase diagrams supports a literal interpretation of the phase diagrams.

Calorimetry↗
PubMed1990

Lipid domains in the ram sperm plasma membrane demonstrated by differential scanning calorimetry.

Mammalian sperm plasma membranes, in contrast to those of mammalian somatic cells, exhibit a significant fraction of lipid that does not diffuse laterally in the plane of the membrane. This nondiffusing fraction results from lipid-lipid interactions. Similar nondiffusing fractions are found in mixed-lipid model systems that contain coexistent gel and fluid domains. These results suggest that the sperm plasma membrane may also exhibit lateral phase segregations of lipids and may contain significant amounts of gel-phase lipid. In this paper we use differential scanning calorimetry to show that, in contrast to the plasma membranes of mammalian somatic cells, the plasma membrane from the anterior region of the head of ram sperm exhibits at least two major endothermic transitions, one centered at approximately 26 degrees C and one centered at approximately 60 degrees C. The heats of these transitions are consistent with gel-to-fluid transitions in model membranes. These transitions are observed both in plasma membrane vesicles and in rehydrated lipid extracts made from these vesicles. These results demonstrate that at physiological temperatures the lipids of the ram sperm plasma membrane are segregated into coexistent fluid and gel domains. Since sperm encounter a wide range of temperatures during their development, these phase transitions may be important in establishing dynamic domains of lipid requisite for epididymal storage and fertilization.

Animals↗
PubMed1998

The thermal stability and domain interactions of the mannitol permease of Escherichia coli. A differential scanning calorimetry study.

The thermal stability and domain interactions in the mannitol transporter from Escherichia coli, enzyme IImtl, have been studied by differential scanning calorimetry. To this end, the wild type enzyme, IICBAmtl, as well as IICBmtl and IICmtl, were reconstituted into a dimyristoylphosphatidylcholine lipid bilayer. The changes in the gel to liquid crystalline transition of the lipid indicated that the protein was inserted into the membrane, disturbing a total of approximately 40 lipid molecules/protein molecule. The thermal unfolding profile of EIImtl exhibited three separate transitions, two of which were overlapping, that could be assigned to structural domains in the protein. Treatment with trypsin, resulting in the degradation of the water-soluble part of the enzyme while leaving the binding and translocation capability of the enzyme intact, resulted in a decrease of the Tm and enthalpy of unfolding of the membrane-embedded C domain. This effect was much more apparent in the presence of the substrate but only partly so in the presence of the substrate analog perseitol. These results are consistent with a recently proposed model (Meijberg, W., Schuurman-Wolters, G. K., and Robillard, G. T. (1998) J. Biol. Chem. 273, 7949-7946), in which the B domain takes part in the conformational changes during the substrate binding process.

Base Sequence↗
PubMed1998

Fatty acyl-CoA binding domain of the transcription factor FadR. Characterization by deletion, affinity labeling, and isothermal titration calorimetry.

The Escherichia coli transcription factor FadR regulates genes required for fatty acid biosynthesis and degradation in an opposing manner. It is acting as an activator of biosynthetic genes and a repressor of degradative genes. The DNA binding of FadR to regions within the promoters of responsive genes and operons is inhibited by long chain acyl-CoA thioesters but not free fatty acids or coenzyme A. The acyl-CoA binding domain of FadR was localized by affinity labeling of the full-length protein and an amino-terminal deletion derivative, FadRDelta1-167, with a palmitoyl-CoA analogue, 9-p-azidophenoxy[9-3H]nonanoic acid-CoA ester. Analysis of labeled peptides generated by tryptic digestion of the affinity-labeled proteins identified one peptide common to both the full-length protein and the deletion derivative. The amino-terminal sequence of the labeled peptide was SLALGFYHK, which corresponds to amino acids 187-195 in FadR. Isothermal titration calorimetry was used to estimate affinity of the wild-type full-length FadR, a His-tagged derivative, and FadRDelta1-167 for acyl-CoA. The binding was characterized by a large negative DeltaH0, -16 to -20 kcal mol-1. No binding was detected for the medium chain ligand C8-CoA. Full-length wild-type FadR and His6-FadR bound oleoyl-CoA and myristoyl-CoA with similar affinities, Kd of 45 and 63 nM and 68 and 59 nM, respectively. The Kd for palmitoyl-CoA binding was about 5-fold higher despite the fact that palmitoyl-CoA is 50-fold more efficient in inhibiting FadR binding to DNA than myristoyl-CoA. The results indicate that both acyl-CoA chain length and the presence of double bonds in the acyl chain affect FadR ligand binding.

Acyl Coenzyme A↗
PubMed2000

Entropic stabilization of the tryptophan synthase alpha-subunit from a hyperthermophile, Pyrococcus furiosus. X-ray analysis and calorimetry.

The structure of the tryptophan synthase alpha-subunit from Pyrococcus furiosus was determined by x-ray analysis at 2.0-A resolution, and its stability was examined by differential scanning calorimetry. Although the structure of the tryptophan synthase alpha(2)beta(2) complex from Salmonella typhimurium has been already determined, this is the first report of the structure of the alpha-subunit alone. The alpha-subunit from P. furiosus (Pf-alpha-subunit) lacked 12 and 6 residues at the N and C termini, respectively, and one residue each in two loop regions as compared with that from S. typhimurium (St-alpha-subunit), resulting in the absence of an N-terminal helix and the shortening of a C-terminal helix. The structure of the Pf-alpha-subunit was essentially similar to that of the St-alpha-subunit in the alpha(2)beta(2) complex. The differences between both structures were discussed in connection with the higher stability of the Pf-alpha-subunit and the complex formation of the alpha- and beta-subunits. Calorimetric results indicated that the Pf-alpha-subunit has extremely high thermostability and that its higher stability is caused by an entropic effect. On the basis of structural information of both proteins, we analyzed the contributions of each stabilization factor and could conclude that hydrophobic interactions in the protein interior do not contribute to the higher stability of the Pf-alpha-subunit. Rather, the increase in ion pairs, decrease in cavity volume, and entropic effects due to shortening of the polypeptide chain play important roles in extremely high stability in Pf-alpha-subunit.

Amino Acid Sequence↗
PubMed2001

Thermodynamics of Ras/effector and Cdc42/effector interactions probed by isothermal titration calorimetry.

Proliferation, differentiation, and morphology of eucaryotic cells is regulated by a large network of signaling molecules. Among the major players are members of the Ras and Rho/Rac subfamilies of small GTPases that bind to different sets of effector proteins. Recognition of multiple effectors is important for communicating signals into different pathways, leading to the question of how an individual GTPase achieves tight binding to diverse targets. To understand the observed specificity, detailed information about binding energetics is expected to complement the information gained from the three-dimensional structures of GTPase/effector protein complexes. Here, the thermodynamics of the interaction of four closely related members of the Ras subfamily with four different effectors and, additionally, the more distantly related Cdc42/WASP couple were quantified by means of isothermal titration calorimetry. The heat capacity changes upon complex formation were rationalized in light of the GTPase/effector complex structures. Changes in enthalpy, entropy, and heat capacity of association with various Ras proteins are similar for the same effector. In contrast, although the structures of the Ras-binding domains are similar, the thermodynamics of the Ras/Raf and Ras/Ral guanine nucleotide dissociation stimulator interactions are quite different. The energy profile of the Cdc42/WASP interaction is similar to Ras/Ral guanine nucleotide dissociation stimulator, despite largely different structures and interface areas of the complexes. Water molecules in the interface cannot fully account for the observed discrepancy but may explain the large range of Ras/effector binding specificity. The differences in the thermodynamic parameters, particularly the entropy changes, could help in the design of effector-specific inhibitors that selectively block a single pathway.

Animals↗
PubMed2003

Apparent cooperative assembly of the bacterial cell division protein FtsZ demonstrated by isothermal titration calorimetry.

The assembly dynamics of FtsZ, a prokaryotic homolog of tubulin, are important for their role in bacterial cytokinesis. Here we used isothermal titration calorimetry (ITC) to measure the heat of FtsZ self-association under various conditions. The measurements were designed to test whether FtsZ protofilaments are assembled by an isodesmic (linear aggregates in which each bond has an identical equilibrium constant) or a cooperative (aggregates only become stable after forming a oligomeric nucleus) assembly process. The isodesmic model can fit the assembly in GDP closely but cannot fit the assembly in GTP. FtsZ-GTP without Mg(2+) exhibits an apparent critical concentration, which is indicative of cooperative assembly, near 2.9 microm. With 2.5 mm Mg(2+) (which allows FtsZ to hydrolyze GTP) the critical concentration is reduced 10-fold to approximately 0.31 microm. Both with and without Mg(2+) there is no evidence for assembly below the critical concentration, but there is an abrupt transition to full assembly above. The ITC data are highly suggestive of a cooperative assembly, although this is difficult to reconcile with the 1-subunit-thick protofilaments observed by electron microscopy.

Bacterial Proteins↗
PubMed2003

Unfolding of rabbit muscle creatine kinase induced by acid. A study using electrospray ionization mass spectrometry, isothermal titration calorimetry, and fluorescence spectroscopy.

Electrospray ionization mass spectrometry, isothermal titration calorimetry (ITC), fluorescence spectroscopy, and glutaraldehyde cross-linking SDS-PAGE have been used to study the unfolding of rabbit muscle creatine kinase (MM-CK) induced by acid. The mass spectrometric experiments show that MM-CK is unfolded gradually when titrated with acid. MM-CK is a dimer (the native state) at pH 7.0 and becomes an equilibrium mixture of the dimer and a partially folded monomer (the intermediate) between pH 6.7 and 5.0. The dimeric protein becomes an equilibrium mixture of the intermediate and an unfolded monomer (the unfolded state) between pH 5.0 and 3.0 and is almost fully unfolded at pH 3.0 reached. The results from a "phase diagram" method of fluorescence show that the conformational transition between the native state and the intermediate of MM-CK occurs in the pH range of 7.0-5.2, and the transition between the intermediate and the unfolded state of the protein occurs between pH 5.2 and 3.0. The intrinsic molar enthalpy changes for formation of the unfolded state of MM-CK induced by acid at 15.0, 25.0, 30.0, and 37.0 degrees C have been determined by ITC. A large positive molar heat capacity change of the unfolding, 8.78 kcal mol-1 K-1, at all temperatures examined indicates that hydrophobic interaction is the dominant driving force stabilizing the native structure of MM-CK. Combining the results from these four methods, we conclude that the acid-induced unfolding of MM-CK follows a "three-state" model and that the intermediate state of the protein is a partially folded monomer.

Acetates↗
PubMed2004

Hydration and packing effects on prion folding and beta-sheet conversion. High pressure spectroscopy and pressure perturbation calorimetry studies.

The main hypothesis for prion diseases proposes that the cellular protein (PrP(C)) can be altered into a misfolded, beta-sheet-rich isoform (PrP(Sc)), which undergoes aggregation and triggers the onset of transmissible spongiform encephalopathies. Here, we compare the stability against pressure and the thermomechanical properties of the alpha-helical and beta-sheet conformations of recombinant murine prion protein, designated as alpha-rPrP and beta-rPrP, respectively. High temperature induces aggregates and a large gain in intermolecular antiparallel beta-sheet (beta-rPrP), a conformation that shares structural similarity with PrP(Sc). alpha-rPrP is highly stable, and only pressures above 5 kilobars (1 kilobar = 100 MegaPascals) cause reversible denaturation, a process that leads to a random and turnrich conformation with concomitant loss of alpha-helix, as measured by Fourier transform infrared spectroscopy. In contrast, aggregates of beta-rPrP are very sensitive to pressure, undergoing transition into a dissociated species that differs from the denatured form derived from alpha-rPrP. The higher susceptibility to pressure of beta-rPrP can be explained by its less hydrated structure. Pressure perturbation calorimetry supports the view that the accessible surface area of alpha-rPrP is much higher than that of beta-rPrP, which explains the lower degree of hydration of beta-rPrP. Our findings shed new light on the mechanism of prion conversion and show how water plays a prominent role. Our results allow us to propose a volume and free energy diagram of the different species involved in the conversion and aggregation. The existence of different folded conformations as well as different denatured states of PrP may explain the elusive character of its conversion into a pathogenic form.

Animals↗
PubMed2004

Direct measurement of the thermodynamic parameters of amyloid formation by isothermal titration calorimetry.

Amyloid fibril deposition is associated with over 20 degenerative diseases, including Alzheimer's, Parkinson's, and prion diseases. Although research over the last few years has revealed the morphology and structural features of the amyloid form, knowledge about the thermodynamics of amyloid formation is limited. Here, we report for the first time a direct thermodynamic study of amyloid formation using isothermal titration calorimetry. Beta(2)-microglobulin, a protein responsible for dialysis-related amyloidosis, was used for extending amyloid fibrils in a seed-controlled reaction in the cell of the calorimeter. We investigated the enthalpy and heat capacity changes of the reaction, where the monomeric, acid-denatured molecules adopt an ordered, cross-beta-sheet structure in the rigid amyloid fibrils. Despite the dramatic difference in morphology, beta(2)-microglobulin exhibited a similar heat capacity change upon amyloid formation to that of the folding to the native globular state, whereas the enthalpy change of the reaction proved to be markedly lower. In comparison with the native state, the results outline the important structural features of the amyloid fibrils: a similar extent of surface burial even with the supramolecular architecture of amyloid fibrils, a lower level of internal packing, and the possible presence of unfavorable side chain contributions.

Amyloid↗
PubMed1989

Energy-sparing adaptations in human pregnancy assessed by whole-body calorimetry.

The hypothesis that the energy cost of human pregnancy can be minimized by energy-sparing metabolic adaptations was tested using serial 24 h whole-body calorimetry. Eight healthy, well-nourished women were studied prepregnant and at 6, 12, 18, 24, 30 and 36 weeks gestation. Basal metabolic rate (BMR) showed highly characteristic changes within each subject and large inter-individual differences (F 3.5, P less than 0.01). Some subjects showed a highly significant depression of metabolism up to 24 weeks gestation in support of the initial hypothesis. At 36 weeks BMR ranged from +8.6 to +35.4% relative to the prepregnant baseline. This wide variability was not explained by differences in the amount of lean tissue gained. Women displaying the energy-sparing suppression of BMR tended to be thin, suggesting that changes in metabolism may be responsive to initial energy status (delta BMR v. prepregnant body fat: r 0.84, P less than 0.005). Changes in 24 h energy expenditure closely paralleled changes in BMR (r 0.98, P less than 0.001), since the energy cost of minor voluntary activity and thermogenesis remained very constant within each individual. Pregnancy decreased the net cost of weight-dependent and weight-independent standard exercises when expressed per kg body-weight: stepping -10 (SD 2)%, P less than 0.001 at 18-36 weeks, cycling -26 (SD 7)%, P less than 0.01 at 12-36 weeks. The average integrated maintenance costs of pregnancy matched previous group estimates from well-nourished women, but individual estimates ranged from -16 to +276 MJ (coefficient of variation 93%). This high level of variability has important implications for the prescription of incremental energy intakes during pregnancy. It may also have had evolutionary significance.

Adaptation, Physiological↗
PubMed1989

The use of heart rate monitoring in the estimation of energy expenditure: a validation study using indirect whole-body calorimetry.

1. A modified heart rate (HR) method for predicting total energy expenditure (TEE) was cross-validated against whole-body calorimetry (CAL). Minute-by-minute HR was converted to energy expenditure (EE) using individual calibration curves when HR exceeded a pre-determined 'FLEX' value designed to discriminate periods of activity. ('FLEX' HR was defined as the mean of the highest HR during rest and the lowest HR during the lightest imposed exercise.) Sedentary EE (below FLEX) was calculated as the mean EE during lying down, sitting and standing at rest. Sleeping EE was calculated as basal metabolic rate (BMR) predicted from standard equations. 2. Calibration curves of oxygen consumption v. HR for different postures at rest and during exercise were obtained for twenty healthy subjects (eleven male, nine female); mean r 0.941 (SD 0.04). The mean FLEX HR for men and women were 86 (SD 10) and 96 (SD 6) beats/min respectively. 3. Simultaneous measurements of HR and EE were made during 21 h continuous CAL, which included 4 x 30 min imposed exercise (cycling, rowing, stepping, jogging). HR exceeded FLEX for a mean of 98 (SD 41) min. Mean TEE by CAL (TEE.CAL) was 8063 (SD 1445) kJ. 4. The HR method yielded a mean non-significant underestimate in TEE (TEE.HR) of 1.2 (SD 6.2)% (range -11.4 to +10.6%). Regression of TEE.HR (Y) v. TEE.CAL (X) yielded Y = 0.868 X + 927 kJ, r 0.943, SE of the estimate 458 kJ, n 20. 5. The satisfactory predictive power and low cost of the method makes it suitable for many field and epidemiological applications.

Adolescent↗
PubMed1993

Intra- and inter-individual variations in energy expenditure of 14-15-year-old schoolgirls as determined by indirect calorimetry.

Eleven 14-15-year-old schoolgirls were investigated four times within 1 year to determine variations in energy expenditure between individuals (inter-individual variability) and within subjects (intra-individual variability). Indirect calorimetry was used to determine metabolic rates in the fasting and resting state (RMR), and during physical activities which were grouped into standardized and non-standardized activities. Analyses of variance supplied information about intra- and inter-individual variabilities of rates of energy expenditure. The mean resting metabolic rate in adolescent girls was 4.41 (SD 0.40) kJ/min. The overall coefficient of variation (9.1%) was approximately twice as high as the mean coefficient within subjects (4.3%). The reproducibility of the RMR of the girls was high (significant F value of variance analysis), even over a prolonged investigation of 1 year. This seemed to depend primarily on the constant body weight during the period of investigation. A workload of 30 W on a bicycle ergometer and walking at an individually chosen speed did not reveal significant differences between inter- and intra-individual variabilities of energy metabolic rates. However, in most non-standardized activities, e.g. relaxation at home, washing dishes and vacuum cleaning, inter-individual variability was significantly higher than intra-individual variability. There are true differences in energy expenditure rates between subjects which may be demonstrated by duplicated measurements. Conclusions on future experimental design were drawn, where differences between groups rather than between individuals are to be studied.

Adolescent↗
PubMed2002

Assessing sleeping energy expenditure in children using heart-rate monitoring calibrated against open-circuit indirect calorimetry: a pilot study.

Total energy expenditure (EE) can be assessed in children by the heart-rate (HR) monitoring technique calibrated against open-circuit indirect calorimetry (IC). In this technique, sleeping EE is usually estimated as the lowest value of a 30 min resting EE measurement x 0 x 90 to give an average for the total sleeping period. However, sleeping is a dynamic process in which sleeping EE is modulated by the effect of factors such as body movement and different sleep stages. The aim of the present study was to determine a new method to improve the sleeping EE measurement by taking into account body movements during sleep. Twenty-four non-obese children participated in the present study. All subjects passed through a calibration period. HR and EE measured by IC were simultaneously collected during resting, the postprandial period, and during different levels of activity. Different methods for computing sleeping EE (resting with different breakpoints ('flex point' HR with linear regression or 'inflection point' (IP) HR with the third order polynomial regression equation (P3)) were compared with EE measured for least 2.0 h in eight sleeping children. The best method of calculation was then tested in sixteen children undergoing HR monitoring and with a body movement detector. In a subset of eight children undergoing simultaneous sleeping EE measurement by IC and HR, the use of the equation resting when HR IP during the sleeping period gave the lowest difference (1 (sd 5.4) %) compared with other methods (linear or polynomial regressions). The new formula was tested in an independent subset of sixteen other children. The difference between sleeping EE computed with the formula resting and sleeping EE computed with resting when HR IP during sleeping periods was significant (13 (sd 5.9) %) only for active sleeping subjects (n 6 of 16 subjects). The correlation between the difference in the results from the two methods of calculation and body movements was close (r 0.63, P<0.005, Spearman test) as well as computed sleeping EE (Spearman test, r 0.679, P<0.001), indicating that this new method is reliable for computing sleeping EE with HR monitoring if children are moving during sleep and improves the total EE assessment.

Calorimetry, Indirect↗