Perception of unfamiliar caregivers during sickness - Using the new Caregiver Perception Task (CgPT) during experimental endotoxemia.

Social withdrawal is a well-established part of sickness behavior, but in some contexts sick animals might gain from keeping close instead of keeping away. For instance, sick individuals are more willing to be near known individuals who can provide care and safety (close others) compared to when healthy. Yet, interactions with some strangers might also be beneficial (i.e., healthcare professionals), but it is not known how sickness interplay with social behavior towards such individuals. Here, we assessed if sickness affects perception of caregivers, and developed a new task, the Caregiver Perception Task (CgPT). Twenty-six participants performed the CgPT, once after an injection of lipopolysaccharide (LPS, 0.8 ng/kg body weight, n = 24), and once after an injection of saline (n = 25), one hour and forty-five minutes post-injection. During the task, participants watched short video clips of three types of caregivers: a healthcare professional taking care of a sick individual, a healthcare professional not taking care of a sick individual, and a non-healthcare professional taking care of their sick adult child or partner. After each video clip, the likability, trustworthiness, professionalism, and willingness to interact with and receive care from the caregiver were rated on visual analogue scales. Results showed that participants injected with saline rated healthcare professionals who did not take care of a sick individual less positively on all aspects compared to healthcare professionals who took care of a sick individual. Moreover, compared to saline, LPS increased the participants' willingness to receive care from healthcare professionals and non-healthcare professionals providing care, but not from healthcare professionals not providing care. Thus, our results indicate that sick individuals may approach unknown individuals with potential to provide care and support.

Breaking the geometric magnetic frustration in controlled off-stoichiometric LuMn1+zO3+δ compounds.

This study explores controlled off-stoichiometric LuMn1+zO3+δ (|z| < 0.1) compounds, intended to retain the utter LuMnO3 intrinsic hexagonal symmetry and ferroelectric properties. X-ray powder diffraction measurements evidenced a single phase P63cm structure. Thermo-gravimetric experiments show a narrow impact of oxygen vacancies while a distinguishable gas exchange at ∼700 K, a surprisingly lower temperature when compared to perovskite systems. A comparison of different nominal ceramics revealed pertinent structural and magnetic property variations owing to subtle self-doping effects. Deviations from the archetypal antiferromagnetic state were detected below ∼90 K suggesting local rearrangements of the nominal Mn(3+) ions matrix, breaking the ideal geometrical spin frustration, leading to a non-compensated magnetic structure.

Driving magnetostructural transitions in layered intermetallic compounds.

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr(0.5)Y(0.5)Mn(2)Ge(2). In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (T(C)(Pr)). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase of the entropy change associated with the lower FOMT (at T(C)(Pr)) is seen under a pressure of 7.5 kbar. First principles calculations, using density functional theory, show that this remarkable magnetic behavior derives from the strong magnetoelastic coupling of the manganese layers in this compound.

Substituting Chromium in Iron-Based Catalysts for the High-Temperature Water-Gas Shift Reaction.

A set of doped iron oxides (chromium, aluminum, gallium, indium, manganese, zinc, niobium) were prepared by a one-step coprecipitation/calcination approach evaluated for their WGS activity under industrially relevant conditions and characterized in detail. The WGS activity after ageing the doped catalyst for 4 days at 25 bar follows the order chromium ≈ aluminum > gallium > indium > manganese > zinc > niobium for copper-codoped catalysts. The activated catalysts predominantly consist of magnetite, irrespective of the dopant. Mössbauer spectra of aged catalysts showed that aluminum and zinc occupy both tetrahedral and octahedral sites of magnetite, while chromium, gallium, indium, manganese, and niobium preferentially substitute octahedral iron. The incorporation of trivalent metal ions of similar size to octahedral Fe3+ (i.e., chromium, aluminum, gallium) results in moderate to high CO conversion, irrespective of incorporation in tetrahedral or octahedral sites. The substitution of Fe2+ with Mn2+ results in an increased Fe3+/Fe2+ ratio. Incorporation of Zn2+ in tetrahedral sites (replacing Fe3+ ions) leads to a complex structure where the charge balance is compensated from the octahedral sites. Separate dopant metal oxide phases were observed in indium- and niobium-doped catalysts. XPS shows that copper is present as a separate phase in activated copper-codoped catalysts. Aluminum is identified as the most promising promoter for substituting chromium in commercial high-temperature WGS catalysts on the basis of their similar high CO conversion although incorporation of these dopants into the magnetite structure differed substantially.

Hormone and metabolic profiles in children and adolescents with type I diabetes mellitus.

Diurnal concentrations of glucose, the major regulatory hormones, and selected biochemistries were measured serially throughout a 25-h period in 38 healthy type I diabetic patients, 25 patients with acute ketoacidosis, and 20 normal subjects. Poor glucose control, meal intolerance, and hypercortisolemia were the dominant abnormalities in the healthy diabetic subjects. Ketonemia due to elevated plasma beta-hydroxybutyrate concentrations without ketonuria (nitroprusside reaction) was a frequent finding in a group of poorly controlled diabetic subjects. In the patients with acute ketoacidosis, the dominant abnormalities were overproduction of epinephrine and cortisol. High glucagon and growth hormone concentrations were documented in about one-half of these patients. We conclude that (1) the hyperglycemia, meal intolerance, and abnormal ketone body metabolism seen in these patients are caused by inadequacies in their insulin regimens; (2) ketone body underutilization contributes to diabetic ketosis; (3) epinephrine and cortisol overproduction are important components of acute ketoacidosis; and (4) the complex hormone-metabolic interactions in type I diabetes can best be explained by a multihormonal hypothesis with the primary defect being loss of beta-cell function.

Interaction of chloramphenicol with phenytoin and phenobarbital. Case report.

The effect of chloramphenicol therapy (48 mg/kg/day) on the serum concentrations of phenytoin and phenobarbital was studied in a patient previously stabilized on anticonvulsant medications. Phenytoin, 12 mg/kg/day, and phenobarbital, 5 mg/kg/day resulted in serum concentrations averaging 10.8 microgram/ml before and 30.5 microgram/ml, after chloramphenicol therapy. A reduction in dose of both phenytoin and phenobarbital was required to minimize adverse effects during the course of chloramphenicol therapy. An average daily dose of phenytoin of 9.1 mg/kg resulted in an average serum concentration of 17.8 microgram/ml. A daily dose of phenobarbital of 4.0 mg/kg resulted in an average serum concentration of 37.1 microgram/ml. These changes indicate 50.5% and 40.4% decreases in clearance of phenytoin and phenobarbital. Multiple-dose nonlinear regression analysis of phenytoin and phenobarbital serum concentration data obtained during chloramphenicol therapy indicated a 62.5% and a 29.5% decrease in clearance. Subsequent serum concentration monitoring demonstrated a similar reduction in phenobarbital clearance when chloramphenicol was added to phenobarbital alone.

Laboratory tests in the analysis of states of dehydration.

In an otherwise healthy child with acute dehydration known to be due to diarrhea or vomiting, the amount of deficit can best be estimated by accurate weight. Total serum protein and hematocrit provide a rough estimate of reduction in circulating blood volume, but calculation from these data will usually underestimate the deficit. Determination of urea nitrogen concentration helps to detect reduced glomerular filtration rate. Acid-base disturbances, most commonly metabolic acidosis, are detected by measuring pH and CO2 content (or base excess). Blood glucose should be measured to rule out diabetes mellitus, even in the absence of a suggestive history. Determination of potassium in serum is most important in the diagnosis of adrenal or renal insufficiency and in the post-acidotic phase after dehydration. Osmolality of body fluids is estimated by measuring [Na+]. Since osmolality of body fluids is normally maintained at the expense of fluid volume by the kidney and the hormones governing renal excretion of water and sodium, abnormal osmolality indicates a serious condition which has to be interpreted with the help of clinical data. In cases of abnormal renal function or of abnormal losses, as with removal of gastrointestinal fluids by suction, or excessive and prolonged diarrhea, measuring volume and composition of excreta may be essential. Because of cumulative deficits, patients with prolonged losses or inability to regulate oral intake by thirst cannot be treated without continual careful interpretation of the reports from a good laboratory.

Direct magnetocaloric characterization and simulation of thermomagnetic cycles.

An experimental setup for the direct measurement of the magnetocaloric effect capable of simulating high frequency magnetothermal cycles on laboratory-scale samples is described. The study of the magnetocaloric properties of working materials under operative conditions is fundamental for the development of innovative devices. Frequency and time dependent characterization can provide essential information on intrinsic features such as magnetic field induced fatigue in materials undergoing first order magnetic phase transitions. A full characterization of the adiabatic temperature change performed for a sample of Gadolinium across its Curie transition shows the good agreement between our results and literature data and in-field differential scanning calorimetry.