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We identify all symmetry-enforced band crossings in nonmagnetic orthorhombic crystals with and without spin-orbit coupling and discuss their topological properties. We find that orthorhombic crystals can host a large number of different band degeneracies, including movable Weyl and Dirac points with hourglass dispersions, fourfold double Weyl points, Weyl and Dirac nodal lines, almost movable nodal lines, nodal chains, and topological nodal planes. Interestingly, spin-orbit coupled materials in the space groups 18, 36, 44, 45, and 46 can have band pairs with only two Weyl points in the entire Brillouin zone. This results in a simpler connectivity of the Fermi arcs and more pronounced topological responses than in materials with four or more Weyl points. In addition, we show that the symmetries of the space groups 56, 61, and 62 enforce nontrivial weak $\mathbb{Z}_2$ topology in materials with strong spin-orbit coupling, leading to helical surface states. With these classification results in hand, we perform extensive database searches for orthorhombic materials crystallizing in the relevant space groups. We find that Sr$_2$Bi$_3$ and Ir$_2$Si have bands crossing the Fermi energy with a symmetry-enforced nontrivial $\mathbb{Z}_2$ invariant, CuIrB possesses nodal chains near the Fermi energy, Pd$_7$Se$_4$ and Ag$_2$Se exhibit fourfold double Weyl points, the latter one even in the absence of spin-orbit coupling, whereas the fourfold degeneracies in AuTlSb are made up from intersecting nodal lines. For each of these examples we compute the ab-initio band structures, discuss their topologies, and for some cases also calculate the surface states., 26 pages, 14 figures, supplemental material

We study the occurrence of symmetry-enforced topological band crossings in tetragonal crystals with strong spin-orbit coupling. By computing the momentum dependence of the symmetry eigenvalues and the global band topology in the entire Brillouin zone, we determine all symmetry-enforced band crossings in tetragonal space groups. In particular, we classify all Dirac and Weyl degeneracies on points, lines, and planes, and find a rich variety of topological degeneracies. This includes, among others, double Weyl points, fourfold-double Weyl points, fourfold-quadruple Weyl points, Weyl and Dirac nodal lines, as well as topological nodal planes. For the space groups with symmetry-enforced Weyl points, we determine the minimal number of Weyl points for a given band pair and, remarkably, find that materials in space groups 119 and 120 can have band pairs with only two Weyl points in the entire Brillouin zone. This simplifies the topological responses, which would be useful for device applications. Using the classification of symmetry-enforced band crossings, we perform an extensive database search for candidate materials with tetragonal space groups. Notably, we find that Ba$_5$In$_4$Bi$_5$ and NaSn$_5$ exhibit twofold and fourfold Weyl nodal lines, respectively, which cross the Fermi energy. Hf$_3$Sb and Cs$_2$Tl$_3$ have band pairs with few number of Weyl points near the Fermi energy. Furthermore, we show that Ba$_3$Sn$_2$ has Weyl points with an accordion dispersion and topological nodal planes, while AuBr and Tl$_4$PbSe$_3$ possess Dirac points with hourglass dispersions. For each of these candidate materials we present the ab-initio band structures and discuss possible experimental signatures of the nontrivial band topology., 31 pages, 17 figures

We consider a two-orbital tight-binding model defined on a layered three-dimensional hexagonal lattice to investigate the properties of topological nodal lines and their associated drumhead surface states. We examine these surface states in centrosymmetric systems, where the bulk nodal lines are of Dirac type (i.e., four-fold degenerate), as well as in non-centrosymmetric systems with strong Rashba and/or Dresselhaus spin-orbit coupling, where the bulk nodal lines are of Weyl type (i.e., two-fold degenerate). We find that in non-centrosymmetric systems the nodal lines and their corresponding drumhead surface states are fully spin polarized due to spin-orbit coupling. We show that unique signatures of the topologically nontrivial drumhead surface states can be measured by means of quasiparticle scattering interference, which we compute for both Dirac and Weyl nodal line semimetals. At the end, we analyze the possible crystal structures with a symmetry that supports flat surface states which are effectively ringlike., 11 pages, 7 figures

Die erfolgreiche Versorgung und Reanimation von Neugeborenen basiert auf Vorbereitung, genauer Evaluation und prompter Unterstutzung entsprechend den kurzlich aktualisierten Empfehlungen durch trainierte Personen. Der wesentliche Schritt der normalen postnatalen Adaptation ist die erfolgreiche Entfaltung der Lunge wahrend der ersten Atemzuge, weil erst danach venoses Blut nahezu vollstandig zur Lunge gelangt und ein Gasaustausch stattfindet. Liegt eine Storung der Adaptation vor, muss deshalb durch geeignete Masnahmen zunachst die Ventilation gesichert werden. Primar wird mit Raumluft (bei Termingeborenen) bzw. niedrigen Sauerstoff-Fraktionen (bei Fruhgeborenen) beatmet. Im weiteren Verlauf wird so viel Sauerstoff gegeben, das physiologische Werte der Sauerstoffsattigung resultieren. Kardiale Kompression wird erst nach suffizienter Beatmung und in einem Verhaltnis zur Ventilation von 3:1 durchgefuhrt. Wesentlicher Bestandteil der Erstversorgung von Neugeborenen ist die konsequente Anwendung warmeerhaltender Masnahmen, da Neugeborene allein durch Hypothermie vital bedroht sind. Eine therapeutische Hypothermie darf daher erst nach erfolgreicher Reanimation in Absprache mit dem weiterversorgenden Perinatalzentrum erwogen werden.

1. Prostaglandins play a major role in maintaining ductal patency in utero. Ductal tone is regulated by both locally released and circulating vasodilatory prostaglandins. In infants with ductus arteriosus-dependent congenital heart disease, ductal patency is maintained by intravenous administration of prostaglandin (PG) E(1). Little information is available regarding the expression of prostaglandin receptors in man. 2. By means of RT-PCR and immunohistochemistry we studied the expression of the PGI(2) receptor (IP), the four different PGE(2) receptors (EP1, EP2, EP3 and EP4), and the receptors for thromboxane (Tx) A(2) (TP), PGD(2) (DP) and PGF(2alpha) (FP) in the ductus arteriosus of three newborn infants with ductus arteriosus-dependent congenital heart disease and intravenous infusion of PGE(1) and of one 8 month old child with a patent ductus arteriosus. 3. The EP3, EP4, FP, IP and TP receptor were markedly expressed at the mRNA and protein level, whereas the EP2 receptor was weakly expressed and the EP1 receptor was detected in two out of four tissue specimens only. The DP receptor was not detected in any of the samples. The most pronounced expression, which was located in the media of the ductus arteriosus, was observed for the EP4 and TP receptors followed by IP and FP receptor protein. 4. These data indicate that ductal patency during the infusion of PGE(1) in infants with ductus arteriosus-dependent congenital heart disease might be mediated by the EP4 and IP receptor. The data further suggest that a heterogeneous population of prostanoid receptors may contribute to the regulation of ductus arteriosus tone in humans.

This study reports on the developmental outcome of a sample of pre-term children with a birth weight ≤1500 g born in 1994 and 1995 studied at the age of 5 to 6 years. The sample included 60 out of 81 surviving pre-term children (74.1%) of a German neonatal intensive care unit which was matched to a control group of 60 kindergarten children of the same region. The results show significant differences between term and pre-term children with regard to their intellectual development, language comprehension, attentiveness, and hyperactivity. Moreover, the pre-term children required more early intervention to compensate for developmental problems. The developmental deficits were intensified by the presence of biological risk factors like increasingly low birth weight, bronchopulmonary dysplasia and intraventricular haemorrhage. Conclusion: differences between term and pre-term children still exist, although the early 1990s witnessed fundamental changes in the treatment of pre-term children. The persistence of these differences is explained mainly by the increase in the survival rate of children with high biological risk factors.

Objective. To evaluate maternal and neonatal plasma concentrations of acetylsalicylic acid and salicylic acid and the neonatal endogenous prostanoid formation during low-dose aspirin prophylaxis (LDA; 100 mg daily) in pregnant women.Methods. Concentrations of acetylsalicylic acid and salicylic acid in maternal plasma after at least 4 weeks of LDA (n = 14) and in umbilical cord plasma of newborns after maternal LDA (n = 7) were determined by gas chromatography–mass spectrometry. Platelet and renal formation of thromboxane A2 and the formation of prostaglandin E2 and prostacyclin were evaluated in vivo by quantification of index metabolites in plasma and urine by gas chromatography–mass spectrometry in neonates after maternal LDA (n = 14) and in a control group.Results. In the pregnant women, acetylsalicylic acid and salicylic acid concentrations rapidly increased after ingestion of LDA. Acetylsalicylic acid was completely eliminated within 4 hours, whereas salicylic acid was detected with low concentrations at 18 and 21 hours after dosing. In the neonates, acetylsalicylic acid was not detected. Salicylic acid was detected in 1 infant only. Platelet thromboxane A2 formation in the newborn infants was significantly suppressed but recovered within 2 to 3 days after discontinuation of LDA. Renal thromboxane A2 formation and the formation of prostaglandin E2 and prostacyclin were not affected by LDA.Conclusion. In pregnant women who are treated with LDA, acetylsalicylic acid is not completely inactivated in the portal circulation but reaches the uteroplacental circulation and exerts antiplatelet effects in the fetus and newborn.

Purpose Hypokalemic salt-losing tubulopathies (Bartter-like syndromes) comprise a set of clinically and genetically distinct inherited renal disorders. Mutations in four renal membrane proteins involved in electrolyte reabsorption have been identified in these disorders: the furosemide-sensitive sodium-potassium-chloride cotransporter NKCC2, the potassium channel ROMK, the chloride channel ClC-Kb, and the thiazide-sensitive sodium-chloride cotransporter NCCT. The aim of this study was to characterize the clinical features associated with each mutation in a large cohort of genetically defined patients. Patients and methods The phenotypic characteristics of 65 patients with molecular defects in NKCC2, ROMK, ClC-Kb, or NCCT were collected retrospectively. Results ROMK and NKCC2 patients presented with polyhydramnios, nephrocalcinosis, and hypo- or isosthenuria. Hypokalemia was less severe in the ROMK patients compared with the NKCC2 patients. In contrast, NCCT patients had hypocalciuria, hypomagnesemia, and marked hypokalemia. While this dissociation of renal calcium and magnesium handling was also observed in some ClC-Kb patients, a few ClC-Kb patients presented with hypercalciuria and hypo- or isosthenuria. Conclusions ROMK, NKCC2, and NCCT mutations usually have uniform clinical presentations, whereas mutations in ClC-Kb occasionally lead to phenotypic overlaps with the NCCT or, less commonly, with the ROMK/NKCC2 cohort. Based on these results, we propose an algorithm for the molecular diagnosis of hypokalemic salt-losing tubulopathies.

The objective of this study was to evaluate the effect of conventional and long-chain polyunsaturated fatty acids (LCP)-enriched preterm formula on prostanoid formation in preterm infants during their first weeks of life. In a prospective, randomized, double-blind study, healthy infants received either formula enriched with LCP (n = 10), standard preterm formula (n = 10), or (expressed) breast milk (n = 10). Urine was sampled, and anthropometric measurements were taken at study entry and after the study period of 3 wk. In vivo formation of prostaglandin E2, thromboxane A2, and prostacyclin was evaluated by measuring the urinary excretion of the respective index metabolities by gas chromatography-mass spectrometry. There were no significant differences in urinary prostanoid excretion and anthropometric data between the groups at the end of the study period. We conclude that neither conventional formula nor supplementation of a preterm formula with LCP for a period of 3 wk substantially influence prostanoid formation in healthy preterm infants.

Immunological and biochemical alterations in atopic dermatitis have been attributed to a deficient conversion of omega-6 fatty acids (i.e. linoleic acid, gamma-linolenic acid, and dihomo-gamma-linolenic acid) to prostaglandin (PG) E1. In patients with atopic dermatitis, however, the formation of PGE1 has not been evaluated so far. We therefore measured plasma concentrations of 15-keto-13,14-dihydro-PGE1, which reflects endogenous PGE1 release, by gas chromatography-mass spectrometry in 31 patients with atopic dermatitis (aged 18-41 years, median 26 years) and in 31 healthy, age- and sex-matched control subjects. In order to exclude a metabolic shift from PGE1 to PGE2, we also measured the plasma levels of 15-keto-13,14-dihydro-PGE2. There was no difference between patients and control subjects with respect to plasma concentrations of 15-keto-13,14-dihydro-PGE1 (3.9-49.6, median 10.3 pg/ml vs. 3.2-80.4, median 8.3 pg/ml, P = 0.22), 15-keto-13,14-dihydro-PGE2 (11.6-201.0, median 24.8 pg/ml vs. 8.6-201.0, median 19.6 pg/ml, P = 0.10), and the ratio of 15-keto-13,14-dihydro-PGE1 to 15-keto-13,14-dihydro-PGE2 (0.17-1.39, median 0.41 vs. 0.2-1.17, median 0.45, P = 0.29). These results indicate that the endogenous formation of both PGE1 and PGE2 is normal in our patients. The results do not confirm the pivotal role that other authors have attributed to a deficient PGE1 formation in the pathogenesis of atopic dermatitis.

Successful resuscitation of newborn infants depends on adequate preparation, exact evaluation and prompt initiation of support according to the recently updated recommendations by trained personnel. The key step in postnatal adaptation is the initiation of breathing with a subsequent increase in pulmonary blood flow and pulmonary gas exchange. Therefore, in compromised newborn infants, adequate ventilation is the most important step in cardiopulmonary resuscitation. Ventilation should be initiated with room air in term infants and with low concentrations of supplemental oxygen in preterm infants. Subsequently, oxygen supplementation should always be guided by pulse oximetry. Chest compressions are only effective if adequate ventilation has been ensured. The compression ventilation ratio remains 3:1. The prevention of heat loss and maintaining a normal body temperature by adequate measures is an essential part of the care for healthy as well as asphyxiated infants. Therapeutic hypothermia should only be initiated after successful resuscitation and consultation with the regional neonatal intensive care unit.

Children with hyperprostaglandin E syndrome, a neonatal variant of Bartter syndrome with enhanced renal and systemic formation of prostaglandin E 2 , have hypercalciuria, nephrocalcinosis, and osteopenia. Because prostaglandin E 2 affects tubular calcium handling, stimulates the formation of calcitriol in vitro, and has osteolytic activity, we studied calcium homeostasis and the influence of prostaglandin E 2 formation on hypercalciuria in nine patients with hyperprostaglandin E syndrome during long-term indomethacin treatment and after its withdrawal. Suppression of prostaglandin E 2 formation by indomethacin resulted in improvement of biochemical and clinical features of hyperprostaglandin E syndrome. However, hypercalciuria, osteopenia, and nephrocalcinosis did not completely resolve. Despite a low calcium diet, daily urinary calcium excretion was enhanced during and after withdrawal of indomethacin treatment (median 6.3, range 5.3 to 14, and median 9.4, range 4.4 to 38 mg/kg per day, respectively). Daily urinary calcium excretion was greater after withdrawal than during indomethacin treatment. Urinary calcium excretion was not correlated with urinary prostaglandin E 2 excretion. Plasma levels of infact parathyroid hormone (median 11, range 6.8 to 12 pmol/L) and calcitriol (median 157, range 108 to 236 pg/ml) were elevated during indomethacin treatment and decreased after withdrawal of indomethacin. These data suggest that hypercalciuria in hyperprostaglandin E syndrome is mainly due to a renal leak of calcium, which is caused by enhanced renal formation of prostaglandin E 2 and a tubular defect not related to prostaglandin E 2 formation. There is no evidence for prostaglandin-stimulated calcitriol formation. Decreasing plasma levels of parathyroid hormone in the presence of renal calcium losses after withdrawal of indomethacin treatment may be due to a bone resorption process caused by systemic prostaglandin formation; the process may contribute to hypercalciuria in the patient not receiving indomethacin.

In this paper we present an optical derotator for scanning vibrometer measurements on rotating objects. The main part of an optical derotator is a rotating prism. Several concepts are known from literature. We have chosen a Dove prism because it can derotate the rotation of the specimen by simply watching through the prism, which rotates with half the speed. The design of our derotator is presented in this paper as well as a discussion of the system performance. In addition we show experimental measurement results on a fan rotating with 3000 rpm.

We describe the case of a 7-year-old boy with osteogenesis imperfecta, who underwent anaesthesia with propofol-fentanyl-nitrous oxide-suxamethonium for orthopaedic surgery of a distal femur fracture. He developed lacticacidosis after short-term propofol infusion (150 min, mean infusion rate 13.5 mg.kg-1.h-1) associated with a prolonged recovery time without serious haemodynamic changes. The highest lactate concentration was 9.2 mmol.l-1 at 160 min after discontinuation of propofol. There was no significant increase in body temperature. The boy fully recovered.

Prostanoids, especially prostaglandin (PG) E(2), are important mediators of uterine relaxation and contractions during gestation and parturition. Inhibitors of PG formation as well as PG analogues are used to modulate uterine tonus. So far, only limited data are available regarding the expression of prostanoid receptors in human pregnant myometrium. In the present study, the expression of the receptors for PGE(2) (EP1, EP2, EP3, EP4), PGF(2alpha) (FP), prostacyclin (IP), and thromboxane A(2) (TP) in human pregnant myometrium was studied by RT-PCR, in situ hybridization and immunohistochemistry. Myometrial tissue was obtained from five women at term and not in labour and from two women who delivered preterm. Tissue specimens were excised from the upper edge of the transverse lower uterine segment incision. In all tissues analysed, EP1, EP2, EP3, EP4, FP, TP and IP receptor mRNA and protein was detected. mRNA expression for PGD(2) (DP) receptor was not detected in the majority of tissue specimens. EP1, EP2, EP4, IP, TP and FP receptor protein was detected on myometrial smooth muscle cells, whereas EP3 receptor protein was only expressed by stromal and endothelial cells. In situ hybridization experiments yielded similar results. The expression of the EP2 receptor mRNA was inversely related to gestational age. We suggest that the contractile effect of PGE(2) at term is probably mediated directly by the EP1 receptor expressed in myometrial smooth muscle cells and indirectly by the EP3 receptor expressed in stromal cells and a decrease in EP2 receptor expression.

1. Prostaglandins play a major role in maintaining ductal patency in utero. Ductal tone is regulated by both locally released and circulating vasodilatory prostaglandins. In infants with ductus arteriosus-dependent congenital heart disease, ductal patency is maintained by intravenous administration of prostaglandin (PG) E(1). Little information is available regarding the expression of prostaglandin receptors in man. 2. By means of RT-PCR and immunohistochemistry we studied the expression of the PGI(2) receptor (IP), the four different PGE(2) receptors (EP1, EP2, EP3 and EP4), and the receptors for thromboxane (Tx) A(2) (TP), PGD(2) (DP) and PGF(2alpha) (FP) in the ductus arteriosus of three newborn infants with ductus arteriosus-dependent congenital heart disease and intravenous infusion of PGE(1) and of one 8 month old child with a patent ductus arteriosus. 3. The EP3, EP4, FP, IP and TP receptor were markedly expressed at the mRNA and protein level, whereas the EP2 receptor was weakly expressed and the EP1 receptor was detected in two out of four tissue specimens only. The DP receptor was not detected in any of the samples. The most pronounced expression, which was located in the media of the ductus arteriosus, was observed for the EP4 and TP receptors followed by IP and FP receptor protein. 4. These data indicate that ductal patency during the infusion of PGE(1) in infants with ductus arteriosus-dependent congenital heart disease might be mediated by the EP4 and IP receptor. The data further suggest that a heterogeneous population of prostanoid receptors may contribute to the regulation of ductus arteriosus tone in humans.

Objective. To characterize a rare inherited hypokalemic salt-losing tubulopathy with linkage to chromosome 1p31. Methods. We conducted a retrospective analysis of the clinical data for 7 patients in whom cosegregation of the disease with chromosome 1p31 had been demonstrated. In addition, in 1 kindred, prenatal diagnosis in the second child was established, allowing a prospective clinical evaluation. Results. Clinical presentation of the patients was homogeneous and included premature birth attributable to polyhydramnios, severe renal salt loss, normotensive hyperreninemia, hypokalemic alkalosis, and excessive hyperprostaglandin E-uria, which suggested the diagnosis of hyperprostaglandin E syndrome/antenatal Bartter syndrome. However, the response to indomethacin was only poor, accounting for a more severe variant of the disease. The patients invariably developed chronic renal failure. The majority had extreme growth retardation, and motor development was markedly delayed. In addition, all patients turned out to be deaf. Conclusion. The hypokalemic salt-losing tubulopathy with chronic renal failure and sensorineural deafness represents not only genetically but also clinically a disease entity distinct from hyperprostaglandin E syndrome/antenatal Bartter syndrome. A pleiotropic effect of a single gene defect is most likely causative for syndromic hearing loss.

Background: The objective of this study was to evaluate the effect of conventional and long-chain polyunsaturated fatty acids (LCP)-enriched preterm formula on the endogenous formation of F 2 -isoprostanes and 8-epi-prostaglandin (PG) F 2α as possible markers of lipid peroxidation in preterm infants during their first weeks of life. Methods: In a prospective, randomized, double-blind study, infants received either formula enriched with LCP (n = 8), standard preterm formula (n = 7), or (expressed) breast milk (n = 8). Urine was sampled at study entry and after the study period of 3 weeks. The formation of F 2 -isoprostanes and 8-epi-PGF 2α was evaluated by measuring the urinary excretion by gas chromatography-mass spectrometry. Results: No differences in the urinary excretion of F 2 -isoprostanes and 8-epi-PGF 2α were observed at the end of the study period. Conclusions: This result suggests that supplementation of a preterm formula with LCP for a period of 3 weeks does not stimulate lipid peroxidation in preterm infants.

Plasma concentrations of prostaglandin (PG) E1 (12-150, median 25 pg ml-1) and 13,14-dihydro-PGE1 (3-62, median 45.5 pg ml-1) were measured by gas chromatography-mass spectrometry in eight newborns with ductus arteriosus-dependent congenital heart disease during continuous intravenous infusion of PGE1. Formation of 13,14-dihydro-PGE1 was demonstrated for the first time in neonates. Since 13,14-dihydro-PGE1 has similar biological activities as the parent compound PGE1, pharmacological effects during PGE1 infusion are most likely related to both PGE1 and the generation and action of 13,14-dihydro-PGE1.

Prostanoids belong to the growing family of eicosanoids, which are all derived from arachidonic acid. Prostanoids act as modulators and mediators in a large spectrum of physiological and pathophysiological processes within the kidney. On the one hand, the potent vasoconstrictor and platelet-aggregating thromboxane (TX) A2 is involved in the pathophysiology of a variety of glomerular diseases, such as haemolytic-uraemic syndrome and immune-mediated glomerulopathies. Prostaglandin (PG) E2, on the other hand, interferes with tubular electrolyte and water handling. Clinical data support the hypothesis that this member of the prostanoid family contributes to the pathophysiology of Bartter's syndrome, hyperprostaglandin E syndrome, idiopathic hypercalciuria and renal diabetes insipidus. Both prostanoids, TXA2 and PGE2, are involved in the pathophysiology of obstructive uropathies. The physiological and protective role of renal vasodilator prostanoids (PGI2 and PGE2) has been studied during treatment with non-steroidal anti-inflammatory drugs. Part of the pharmacological effects of frusemide and converting enzyme inhibitors is mediated by PGI2 and PGE2. The role of renal prostanoids in cyclosporine toxicity is still equivocal. Future investigations on the physiological and pathophysiological role of renal prostanoids will have to consider the multiple interactions between prostanoids on the one hand, and classical hormones and other mediators (e.g. cytokines) on the other hand.

The relatively low solubility of oxygen in water presents a problem in particular when immobilized cells are used or enzymes are applied for oxygen dependent reactions. The other main purpose is the requirement of oxygen for the increase of biomass. In this investigation the usefulness of silicon emulsions as oxygen carriers is demonstrated. In case of l-amino acid oxidase activity of immobilized cells, an increase by a factor of four was found in the presence of silicon emulsions. Likewise, growth medium enriched with silicon emulsions showed a significantly increased growth of cells inside alginate beads compared to normal growth medium.

The content of dissolved oxygen was determined by four independent methods in a series of non-aqueous or heterogenous systems. The Lex-O2-Content Analyzer represents a fast and simple apparatus that employs a coulometric oxygen assay with Hersch cell detection. A comparison of the results with different methods demonstrates the reliability of the Lex-O2 in the determination of oxygen dissolved in heterogeneous or non-aqueous systems. Therefore, this apparatus can be recommended for the measurement of oxygen in oxygenator or perfusion fluids, as well as in blood substitutes or other oxygen transporting systems.