[Febrile episodes, headache and limb pain as well as generalized myalgia in a 27-year-old returning male traveller]. / Fieberschübe, Kopf- und Gliederschmerzen sowie generalisierte Myalgien bei einem 27-jährigen Reiserückkehrer.

Unspecific flu-like symptoms, such as fever, headache and limb pain are encountered very often by general practitioners and in emergency departments. In patients with sepsis and a history of travelling to warmer climates, the differential diagnosis needs to be broader than just commonly encountered viral infections. A 27-year-old Swiss man presented with the symptoms mentioned above after a holiday in the south of France. The pulmonary, hepatic and renal status rapidly deteriorated and the patient required intensive care. The initially suspected diagnosis of leptospirosis could be confirmed serologically during the course of the disease.

Large energy storage efficiency of the dielectric layer of graphene nanocapacitors.

Electric capacitors are commonly used in electronic circuits for the short-term storage of small amounts of energy. It is desirable however to use capacitors to store much larger energy amounts to replace rechargeable batteries. Unfortunately existing capacitors cannot store sufficient energy to be able to replace common electrochemical energy storage systems. Here we examine the energy storage capabilities of graphene nanocapacitors, which are tri-layer devices involving an Al film, Al2O3 dielectric layer, and a single layer of carbon atoms, i.e., graphene. This is a purely electronic capacitor and therefore it can function in a wide temperature interval. The capacitor shows a high dielectric breakdown electric field strength, of the order of 1000 kV mm-1 (i.e., 1 GV m-1), which is much larger than the table value of the Al2O3 dielectric strength. The corresponding energy density is 10-100 times larger than the energy density of a common electrolytic capacitor. Moreover, we discover that the amount of charge stored in the dielectric layer can be equal or can even exceed the amount of charge stored on the capacitor plates. The dielectric discharge current follows a power-law time dependence. We suggest a model to explain this behavior.

Reducing microwave absorption with fast frequency modulation.

We study the response of a two-level quantum system to a chirp signal, using both numerical and analytical methods. The numerical method is based on numerical solutions of the Schrödinger solution of the two-level system, while the analytical method is based on an approximate solution of the same equations. We find that when two-level systems are perturbed by a chirp signal, the peak population of the initially unpopulated state exhibits a high sensitivity to frequency modulation rate. We also find that the aforementioned sensitivity depends on the strength of the forcing, and weaker forcings result in a higher sensitivity, where the frequency modulation rate required to produce the same reduction in peak population would be lower. We discuss potential applications of this result in the field of microwave power transmission, as it shows applying fast frequency modulation to transmitted microwaves used for power transmission could decrease unintended absorption of microwaves by organic tissue.

Recovery of Alumina Nanocapacitors after High Voltage Breakdown.

Breakdown of a dielectric material at high electric fields significantly limits the applicability of metal-dielectric-metal capacitors for energy storage applications. Here we demonstrate that the insulating properties of atomic-layer-deposited Al2O3 thin films in Al/Al2O3/Al trilayers can recover after the breakdown. The recovery has been observed in samples with the dielectric thickness spanning from 4 to 9 nm. This phenomenon holds promise for a new generation of capacitors capable of restoring their properties after the dielectric breakdown. Also, if employed in capacitor banks, the recovery process will ensure that the bank remains operational even if a breakdown occurs.

Topological properties of a self-assembled electrical network via ab initio calculation.

Interacting electrical conductors self-assemble to form tree like networks in the presence of applied voltages or currents. Experiments have shown that the degree distribution of the steady state networks are identical over a wide range of network sizes. In this work we develop a new model of the self-assembly process starting from the underlying physical interaction between conductors. In agreement with experimental results we find that for steady state networks, our model predicts that the fraction of endpoints is a constant of 0.252, and the fraction of branch points is 0.237. We find that our model predicts that these scaling properties also hold for the network during the approach to the steady state as well. In addition, we also reproduce the experimental distribution of nodes with a given Strahler number for all steady state networks studied.

Stability and conductivity of self assembled wires in a transverse electric field.

Self assembling wire networks typically evolve to minimize the resistance across electrical contacts which are frequently used in a manner comparable to Hebbian learning. In this work, we demonstrate that electrical fields can also be used to cause an increase in the resistance of the wire network. We show that if such a wire is exposed to a transverse electric field, the wire is deformed in a way that depends on it's tensile strength. We measure the wire resistance as a function of transverse field for several field strengths and show that by deforming the wire, the amplitude of the resulting shape can be modified in a controllable fashion. At a critical value of the transverse field, we show that the wire loses stability. At this point we observe thresholding behavior in that the resistance increases abruptly to a maximum value and the wire is destroyed. This thresholding behavior suggests that self assembled wires may be manipulated via an transverse electric field and demonstrates that a mechanism exists for the destruction of undesirable connections.

[Screening prior to surgery and interventions]. / Screening vor Operationen und Interventionen.

Routine preoperative screening is often performed but seldom indicated. The evidence for such procedures is weak or lacking. Advanced patient age is also not a reasonable trigger to initiate testing. Obtaining a detailed, standardized bleeding history, for example using a questionnaire, is much more valuable than blind testing for coagulation parameters. Of primary importance are a detailed medical history with special focus on the patient's individual fitness and a thorough physical examination. Specific blood tests may then follow. Renal function tests are indicated as routine if major surgery with intraoperative volume restriction is planned. Routine preoperative chest radiography is almost never indicated.

Self-assembled wiggling nano-structures and the principle of maximum entropy production.

While behavior of equilibrium systems is well understood, evolution of nonequilibrium ones is much less clear. Yet, many researches have suggested that the principle of the maximum entropy production is of key importance in complex systems away from equilibrium. Here, we present a quantitative study of large ensembles of carbon nanotubes suspended in a non-conducting non-polar fluid subject to a strong electric field. Being driven out of equilibrium, the suspension spontaneously organizes into an electrically conducting state under a wide range of parameters. Such self-assembly allows the Joule heating and, therefore, the entropy production in the fluid, to be maximized. Curiously, we find that emerging self-assembled structures can start to wiggle. The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable. Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium.

[Cardioprotection]. / Kardioprotektion.

The demographic change is associated with an increasing number of elderly patients with serious comorbidities. The prevalence of coronary heart disease in particular increases with age and raises the risk of perioperative myocardial ischemia. In the last few years various interventions have been evaluated to lower the perioperative risk for serious cardiovascular events. This includes cardioprotective medical interventions, for example with ß-receptor blockers and statins. Current guidelines recommend that patients who are on ß-receptor blockers or statins for chronic treatment of cardiovascular diseases should continue this medication throughout the perioperative period. Myocardial conditioning has been assessed to be effective under numerous experimental conditions and clinical trials have also provided evidence for myocardial protection by conditioning. Besides ischemic and anesthetic-induced preconditioning the noninvasive technique of remote preconditioning offers interesting possibilities, especially for patients with serious comorbidities; however, large scale randomized clinical multicentre trials are still needed. Regarding cardioprotective effectiveness, the clinical data for regional anesthesia are very heterogeneous; nevertheless regional anesthesia is very effective in postoperative pain therapy. Therefore regional anesthesia should be used as a part of multimodal therapy concepts to lower the risk of perioperative cardiovascular events.

[Tracheal agenesis. A rare cause of respiratory insufficiency in neonates]. / Trachealagenesie. Eine seltene Ursache der respiratorischen Insuffizienz des Neugeborenen.

Tracheal agenesis is a very rare congenital anomaly that occurs isolated or in combination with other anomalies. It presents immediately after birth with an absolute respiratory insufficiency and lack of crying. The immediate precise anatomical classification of the anomaly is crucial in order to decide if surgical therapy is possible. This report describes a newborn boy with tracheal agenesis type II. The diagnosis was confirmed by spiral computed tomography and a selection of the pictures is presented. The treatment was discontinued due to a lack of therapeutical options. Based on this case report we discuss the special situation of this rare anomaly. Interesting information on tracheal agenesis was gathered, the differential diagnosis of respiratory insufficiency of the newborn is summarised and a modified algorithm of the current newborn resuscitation guidelines of the American Heart Association is presented.

Cystic fibrosis in 65- and 67-year-old siblings. Clinical feature and nasal potential difference measurement in patients with genotypes F508del and 2789+5G-->A.

Cystic fibrosis (CF) is a recessive genetic disease caused by defects of the cystic fibrosis trans-membrane regulator (CFTR) gene with a median survival of less than 35 years. This work reports on the oldest living German siblings with CF. Besides clinical history, CF genotype and nasal potential difference (NPD) measurement results, the remarkably high exercise activity of the siblings is discussed as a disease-modifying factor. Both male patients have an overall mild pulmonary manifestation. They have suffered from abdominal symptoms since their early childhood, including recurrent pancreatitis and diffuse symptoms leading to partial gastric resection. They were diagnosed as having CF with positive sweat tests at the advanced ages of 45 and 43 years, respectively. Later on genotyping revealed compound heterozygosity for F508del and 2789+5G-->A. Using NPD we demonstrated a CF-typical inhibition of the NPD by the Na channel blocker amiloride, although in both siblings the remaining CFTR function and alternate chloride channel function were detected during superfusion of the nasal epithelium with isoproterenol and ATP. Long-term survival with CF is basically influenced by the CFTR genotype. The patients' genotype was discussed as a mild one with remaining CFTR function. We demonstrated this residual CFTR function in both siblings using NPD. Additionally the siblings' continuous healthy lifestyle and their engagement in a remarkably high level of exercise activities from early childhood to the present possibly have an important effect on the long-term outcome of CF as disease-modifying factors. In this regard this report can encourage CF patients to maintain a high level of physical activity in their daily lives.

[Plans to reduce pain in the neonatal intensive care]. / Konzepte zur Schmerzreduktion in der neonatalen Intensivtherapie.

Prolonged pain influences behaviour and physiological regulation in preterm infants undergoing intensive care. Insufficient pain treatment results in increased morbidity and mortality. Long-term consequences of stress and pain yet are not clear, but associations with neurobehavioral and developmental sequelae are discussed. A number of psychometric constructs (pain scales) are available to identify pain indicators. These pain scales represent the basis to consider treatment strategies. Main indications are painful interventional procedures, analgesia during mechanical ventilation and the reduction of pain following surgery. Supporting approaches to reduce pain and stress relate to infant's behaviour, care of the professionals and improvement of "infant's world". Pharmacologic interventions are practicable with acetaminophen in mild pain and with opioid drugs (fentanyl and morphine) in moderate and severe pain. A pure or complementary sedative agent can provide physiological stability in settings in which there are less acutely painful stimuli. After standard pain evaluation it is necessary to individualize treatment, to monitor clinical situation and to adjust dosage. Actual knowledge allows an effective reduction of pain even in very premature infants. Because of lack of clarity about early development of pain and stress reactivity at the time it is necessary to estimate benefits against potential risks of therapy.

[Interdisciplinary treatment of early-onset ornithine transcarbamylase (OTC) deficiency. Two case reports and a review]. / Interdisziplinäre Behandlung des frühmanifesten Ornithintranscarbamylase(OTC)-Mangels1 - Zwei Patientenberichte und Literaturübersicht -

PATIENT REPORTS: We report on a male preterm infant (gestational age 31 weeks, birth weight 1420 g) and a male term infant (gestational age 38 weeks, birth weight 3680 g) with ornithine transcarbamylase (OTC) deficiency. After inconspicuous cardiopulmonary adjustment, both entered a state of metabolic crisis with respiratory insufficiency and ventilatory requirement at the 2nd and 4th day of life, respectively. Diagnosis of hyperammonemia (NH(3) > 1000 micromol/l) was followed by the detection of a plasma amino acid pattern that is typical for OTC-deficiency and an excessive orotic aciduria. Beside intravenous treatment (insulin-glucose-infusion, lipid infusion, sodium benzoate, arginine, L-carnitine), the preterm infant received an exchange transfusion and was supplied with central venous catheters, hemofiltration and hemodialysis. He died after severe disturbances of circulation and coagulation at the 14th day. The male term infant tolerated the effective hemofiltration and was dicharged home with specific therapy at day 26. CONCLUSIONS: Time of diagnosis and influence of additional risk factors are decisively for the prognosis of OTC-deficiency. The immediate aims of therapy (stabilization of vital functions, reduction of plasma ammonium, control of nutrition) can only be realized in cooperation between neonatology, division of metabolism, pediatric nephrology and pediatric surgery.

Spectral analysis of electroencephalogram during sleep-related apneas in pre-term and term born infants in the first weeks of life.

OBJECTIVES: A correlation between sudden infant death syndrome (SIDS) and apnea has been discussed in a variety of studies. We analyzed polysomnographic data in 51 infants and investigated correlations between the manifestation of apneas and changes in EEG pattern. METHODS: Measurements were performed by means of the commercial polysomnographic device 'ALICE III'. Spectral analysis of certain parts of the registered EEG was performed. RESULTS: During apnea a reduction of the EEG amplitude was seen. The extent of the decrease differed slightly between the frequency bands. CONCLUSIONS: According to the widespread agreement that a lower voltage of electrical brain activity is a fundamental sign of waking up, we hypothesize that the observed change might be an immature type of arousal reaction.

Adaptation to the edge of chaos in the self-adjusting logistic map.

Self-adjusting, or adaptive, systems have gathered much recent interest. We present a model for self-adjusting systems which treats the control parameters of the system as slowly varying, rather than constant. The dynamics of these parameters is governed by a low-pass filtered feedback from the dynamical variables of the system. We apply this model to the logistic map and examine the behavior of the control parameter. We find that the parameter leaves the chaotic regime. We observe a high probability of finding the parameter at the boundary between periodicity and chaos. We therefore find that this system exhibits adaptation to the edge of chaos.

Molecular cytogenetic characterisation of partial trisomy 9q in a case with pyloric stenosis and a review.

Partial trisomy 9q represents a rare and heterogeneous group of chromosomal aberrations characterised by various clinical features including pyloric stenosis. Here, we describe the case of a 1 year old female patient with different dysmorphic features including pyloric stenosis and prenatally detected partial trisomy 9q. This partial trisomy 9q has been analysed in detail to determine the size of the duplication and to characterise the chromosomal breakpoints. According to the data gained by different molecular cytogenetic techniques, such as fluorescence in situ hybridisation (FISH) with whole and partial chromosome painting probes, yeast artificial chromosome (YAC) probes, and comparative genomic hybridisation (CGH), the derivative chromosome 9 can be described as dup(9)(pter-->q22. 1::q31.1-->q22.1::q31.1--> q22.1::q31.1-->qter). Four breakpoint spanning YACs have been identified (y806f02, y906g6, y945f5, and y747b3) for the proximal breakpoint. According to this new case and previously published data, the recently postulated putative critical region for pyloric stenosis can be narrowed down to the subbands 9q22.1-q31.1 and is the result of either partial trisomy of gene(s) located in this region or a gene disrupted in 9q31.

Insulin-like growth factor serum concentrations reflect insufficient growth in a hypoplastic infant with partial trisomy 9q in the 12th week of life.

This report presents changes of IGFs and IGFBPs in a female infant with partial trisomy 9q in the 12th week of life. Studying deficient growth in this hypoplastic infant (birth weight 1405 g, birth length 36 cm) with dysmorphic features, the following changes in IGFs and IGFBPs were detected (microg/l): IGF-I: 26.5 vs 48.1 in healthy infants; IGF-II: 420 vs 728; IGFBP-2: 931 vs 524; IGFBP-3: 800 vs 1070. This demonstrates that IGFs and IGFBPs may reflect individual insufficient growth even at this early age.

Dysregulation of insulin-like growth factors in a case of generalized acquired lipoatrophic diabetes mellitus (Lawrence Syndrome) connected with autoantibodies against adipocyte membranes.

We report on a 33-year-old male patient with generalized acquired lipodystrophy, insulin resistant diabetes mellitus and acanthosis nigricans (Lawrence Syndrome). First probable symptoms of lipodystrophy (weight loss, shrinkage of subcutaneous fatty tissue, and loss of muscular strength) became evident three years ago, with the onset of diabetes mellitus occurring about six months later. The patient suffered from the following clinical symptoms: IDDM with increasing insulin-requirement, extreme reduction of fatty tissue, fatty liver hepatitis with elevated liver enzymes, glomerulopathy, muscular and neuropathic pains, as well as hypertriglyceridaemia. A basal C-peptide concentration is rather high. Definitely, the endogenous insulin secretion is increased. In other words, insulin resistance is documented. In an effort to identify the pathogenetic mechanisms of lipoatrophic diabetes mellitus in this patient and to develop a therapeutic strategy, antibodies against different tissues and endocrinologic regulation were investigated. It was possible to demonstrate the presence of serum autoantibodies against lipocytes of the subcutis and other tissues, against hepatic stellate cells, together with autoantibodies against different endocrine organs. By studying the basis of diabetic abnormalities relating to the growth hormone (GH), the insulin-like growth factor (IGF) dynamics in this patient, i.e. reductions of GH, IGF-I, IGF-II, IGF-Binding protein (IGF-BP) 2 and IGF-BP 3, were detected. An immunosuppressive treatment strategy was not beneficial.