Antarctica challenges human explorers by its extreme environment. The effects of these unique conditions on the human physiology need to be understood to best mitigate health problems in Antarctic expedition crews. Moreover, Antarctica is an adequate Earth-bound analogue for long-term space missions. To date, its effects on human physiology have been studied mainly in male cohorts though more female expeditioners and applicants in astronaut training programs are selected. Therefore, the identification of sex differences in stress and immune reactions are becoming an even more essential aim to provide a more individualized risk management. Ten female and 16 male subjects participated in three 1-year expeditions to the German Antarctic Research Station Neumayer III. Blood, saliva, and urine samples were taken 1–2 months prior to departure, subsequently every month during their expedition, and 3–4 months after return from Antarctica. Analyses included cortisol, catecholamine and endocannabinoid measurements; psychological evaluation; differential blood count; and recall antigen- and mitogen-stimulated cytokine profiles. Cortisol showed significantly higher concentrations in females than males during winter whereas no enhanced psychological stress was detected in both sexes. Catecholamine excretion was higher in males than females but never showed significant increases compared to baseline. Endocannabinoids and N-acylethanolamides increased significantly in both sexes and stayed consistently elevated during the confinement. Cytokine profiles after in vitro stimulation revealed no sex differences but resulted in significant time-dependent changes. Hemoglobin and hematocrit were significantly higher in males than females, and hemoglobin increased significantly in both sexes compared to baseline. Platelet counts were significantly higher in females than males. Leukocytes and granulocyte concentrations increased during confinement with a dip for both sexes in winter whereas lymphocytes were significantly elevated in both sexes during the confinement. The extreme environment of Antarctica seems to trigger some distinct stress and immune responses but—with the exception of cortisol and blood cell counts—without any major relevant sex-specific differences. Stated sex differences were shown to be independent of enhanced psychological stress and seem to be related to the environmental conditions. However, sources and consequences of these sex differences have to be further elucidated.

•Determine if anthropometric factors play a role in +G tolerance.•Twenty test subjects underwent 2 rounds of +G in a short arm human centrifuge.•Anthropometric analysis was performed via air displacement plethysmography.•Anthropometric factors augmented hemodynamics.•Anthropometric factors augment orthostatic stability during +G.

BACKGROUNDClinical temperature management remains challenging. Choosing the right sensor location to determine the core body temperature is a particular matter of academic and clinical debate. This study aimed to investigate the relationship of measured temperatures at different sites during surgery in deep hypothermic patients.METHODSIn this prospective single-centre study, we studied 24 patients undergoing cardiothoracic surgery: 12 in normothermia, 3 in mild, and 9 in deep hypothermia. Temperature recordings of a non-invasive heat flux sensor at the forehead were compared with the arterial outlet temperature of a heart-lung machine, with the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, with oesophageal temperature.RESULTSUsing a linear model for sensor comparison, the arterial outlet sensor showed a difference among the other sensor positions between -0.54 and -1.12°C. The 95% confidence interval ranged between 7.06 and 8.82°C for the upper limit and -8.14 and -10.62°C for the lower limit. Because of the hysteretic shape, the curves were divided into phases and fitted into a non-linear model according to time and placement of the sensors. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12°C).CONCLUSIONWe suggest that measured surrogate temperatures as indices of the cerebral temperature (e.g. vesical bladder temperature) should be interpreted with respect to the temporal and spatial dispersion during cooling and rewarming phases.

Die Dyslipoproteinämie bei Diabetes repräsentiert eine komplexe Pathophysiologie atherogener Lipoproteinfraktionen, die eng mit der Dysglykämie und den Komorbiditäten, besonders der viszeralen Adipositas verknüpft sind. Die Diagnostik umfasst deshalb die Triglyzeride, Cholesterin, LDL-Cholesterin und HDL-Cholesterin, ggf. Apo B und Lp(a) als Grundlage einer differenzierten Betrachtung des Lipidrisikos und einer multimodalen Therapie. Da Typ-2-Diabetiker a priori eine Hochrisikogruppe für kardiovaskuläre Erkrankungen darstellen, empfehlen nationale und internationale Leitlinien eine strikte Kontrolle der Lipidtrias mit LDL-Cholesterin < 70 mg/dl, Triglyzeriden < 150 mg/dl und HDL-Cholesterol > 40 mg/dl bei Männern resp. > 50 mg/dl bei Frauen. Lebensstil-Intervention mit Gewichtsreduktion und physischer Konditionierung ist als Basistherapie eine primäre, effektive und sichere Option für die Senkung erhöhter Triglyzeride, verbunden mit moderatem Anstieg des HDL-Cholesterins. LDL-Cholesterin wird dadurch nur marginal gebessert. Statine sind aufgrund ihres umfassend dokumentierten präventiven Nutzens bei Typ-2-Diabetikern obligat. Es bleibt aber auch bei LDL-Cholesterinwerten im Zielbereich unter 100 mg/dl ein hohes „Lipidrestrisiko“. Hier setzt die multimodale Therapie als Add-on ein oder im Fall einer Statinunverträglichkeit als Monotherapie. Hierfür stehen 3 Substanzgruppen zur Verfügung: Fibrate, Nikotinsäure, Omega-3-Fettsäuren, für die allerdings nur wenige evidenzbasierte Daten aus kontrollierten Outcomestudien zur Verfügung stehen. Bei dieser komplexen Lage ist eine individualisierte Therapie erforderlich, die sich an der Pathophysiologie, dem Typ der Fettstoffwechselstörung und dem globalen Risiko des Patienten orientiert. Der vorliegende Review möchte eine Anleitung zur risikoadjustierten, rationellen, multimodalen Lipidtherapie vermitteln.

Accurate measurement of the core body temperature (cbt) is fundamental to the study of human temperature regulation. As standard sites for the placement of cbt measurement sensors have been used: the rectum, the bladder, the esophagus, the nasopharynx and the acoustic meatus. Nevertheless those measurement sites exhibit limited applicability under field conditions, in rescue operations or during peri- and postoperative long-term core temperature monitoring. There is, indeed, a high demand for a reliable, non-invasive, easy to handle telemetric device. But the ideal non-invasive measurement of core temperature has to meet requirements such as i) a convenient measurement site, ii) no bias through environmental conditions, and iii) a high sensitivity of the sensor regarding time shift and absolute temperature value. Recently, together with the Draegerwerke AG we have developed a new heat flux measurement device (so-called “Double Sensor”) as a non-invasive cbt sensor aiming to meet the requirements described above. Four recent studies in humans will be summarized and discussed to show the applicability of this new non-invasive method to monitor core temperature under different environmental and clinical settings on Earth and in space.

Dyslipoproteinemia in patients with diabetes represents a complex pathophysiology of atherogenic lipoprotein fractions which are strongly influenced by quality of glycemic control and visceral obesity. Therefore the diagnostic comprise total cholesterol, LDL-cholesterol, triglycerides and HDL-cholesterol, eventually complmented by apoB and Lp(a) as basis of risk estimation and of multimodale integrated therapy. Since type 2 diabetes already itself is a major cardiovascular risk factor national and international guideline recommend strict control of all three parameters of the lipid triad: LDL-cholesterol < 70mg/dl, triglycerides < 150mg/dl and HDL-Cholesterol in males of > 40mg/dl and females > 50mg/dl. Lifestyle intervention with reduction of overweight and appropriate physical exercise is in any case an essential effective and safe part of treatment of hypertriglyceridemia/low HDL, with little effect on LDL-cholesterol. Guidelines recommend statins in patients with type 2 diabetes since they represent a high risk group for cardiovascular disease with class Ia evidence from randomized trials. However despite LDL-cholesterol levels < 100mg/dl under statin treatment there remains a high lipid risk in the case of diabetic dyslipidemia. Therefore patients with low HDL/hypertriglyceridemia syndrome need an add-on therapy to completely correct the lipid triad. There are three classes of drugs with cardioprotective potentials: fibrates, nicotinic acid derivatives and omega 3 fatty acids. There exist only inconsistent data on cardiovascular outcome for add-on therapy to statins in patients with diabetes. Therefore an individualized decision based on pathophysiology and global risk estimation is essential. This review presents a guide to individualized risk adjusted treatment of multimodale lipid-therapy of patients with diabetes.

Einleitung: Patienten mit Diabetes mellitus Typ 2 und kardiovaskulären Erkrankungen könnten eine Hochrisikogruppe für Herzrhythmusstörungen und den plötzlichen Herztod im Zusammenhang mit Hypoglykämien darstellen. Aktuell ist wenig bekannt über die Häufigkeit von asymptomatischen Hypoglykämien, insbesondere über das Auftreten von nächtlichen Hypoglykämien sowie über die Häufigkeit von Arrhythmien und ihre Beziehung zu Glukoseschwankungen.

The objective of our study was to establish whether rectal temperature recordings in humans could be replaced by a non-invasive skin temperature sensor combined with a heat flux sensor (Double Sensor) located at the forehead to monitor core body temperature changes due to circadian rhythms. Rectal and Double Sensor data were collected continuously for 24h in seven men undertaking strict head-down tilt bed-rest. Individual differences between the two techniques varied between −0.72 and +0.55°C. Nonetheless, when temperature data were approximated by cosinor analysis in order to compare circadian rhythm profiles between methods, it was observed that there were no significant differences between mesor, amplitude, and acrophase (P>0.310). It was therefore concluded that the Double Sensor technology is presently not accurate enough for performing single individual core body temperature measurements under resting conditions at normal ambient room temperature. Yet, it seems to be a valid, non-invasive alternative for monitoring circadian rhythm profiles.

We present a simple model to describe the line-profile of velocity modulated ions. This model is based on Langevin's theory of the mobility and on the independence of the electric field strength on the discharge current in the ideal positive column. A comparison of time constants responsible for the drift of the ions, the concentration, and the ignition and extinction of the discharge itself is essential for a rough understanding of the velocity modulation. The behaviour of H3O+ ions in an ac glow discharge was examined. Under our experimental conditions the line-profile can be explained by a temporal dependence of the velocity which is close to a square-wave. Due to this particular temporal dependence the amplitude of the signal only depends on the concentration modulation, while the line-shape is a simple difference line-profile.

A broadly tunable CW colour-centre laser spectrometer is described. The tuning mechanism and the problems for broad-band continuous single-mode tuning (about 50 cm-1 in two hours) are discussed. Calibrating and scanning of a laser is obtained by a 68000-VME-Bus microcomputer system (Eltec, Eurocom 3), while the frequency calibration and evaluation is done by an 80286 personal computer (Hewlett Packard, Vectra). Some structures for comfortable data processing of spectral files from continuously tunable lasers are presented. Measurements of frequency stability and the linearity of the tuning behaviour show that the spectrometer can be used routinely for Doppler-limited spectroscopy (minimum step width 10 MHz) of molecular transitions.

This paper reports the first frequency measurements of a Lamb-dip-stabilized 12C16O laser. The laser was stabilized to the optogalvanic Lamb dip of the CO molecule excited in a low-pressure dc discharge. The region of study was for transitions with lower state vibrational quantum numbers ranging from v″ = 6 to v″ = 16. Supplementary Doppler limited measurements are also reported for the range v″ = 16 to v″ = 34. The frequencies were directly measured in a heterodyne experiment in which two saturation-stabilized CO2 lasers were used as references. By fitting the transition frequencies to the Dunham expression, we have determined new coefficients which fit the new sub-Doppler data with over an order of magnitude more accuracy than previous coefficients.

The first direct observation of the IR transitions assigned to the B 1Π g -A 1Σ u + band of He2 is reported. The electronic term difference is ΔT e1 = 3549·518 cm-1 in agreement with previous values derived indirectly.

The perpendicular v 3 fundamental band of the H3O+-ion has been remeasured with a colour centre laser. Improved results have been achieved by combining our experimental data with the recently published line positions of Begemann et al. and Bunker et al. For the first time the l-type doubling constant for the a-species has been determined, together with an additional l-type resonance parameter which describes the splitting of the (Kl) = -2 level.