Field-Tunable Berezinskii-Kosterlitz-Thouless Correlations in a Heisenberg Magnet.

We report the manifestation of field-induced Berezinskii-Kosterlitz-Thouless (BKT) correlations in the weakly coupled spin-1/2 Heisenberg layers of the molecular-based bulk material [Cu(pz)_{2}(2-HOpy)_{2}](PF_{6})_{2}. At zero field, a transition to long-range order occurs at 1.38 K, caused by a weak intrinsic easy-plane anisotropy and an interlayer exchange of J^{'}/k_{B}≈1 mK. Because of the moderate intralayer exchange coupling of J/k_{B}=6.8 K, the application of laboratory magnetic fields induces a substantial XY anisotropy of the spin correlations. Crucially, this provides a significant BKT regime, as the tiny interlayer exchange J^{'} only induces 3D correlations upon close approach to the BKT transition with its exponential growth in the spin-correlation length. We employ nuclear magnetic resonance measurements to probe the spin correlations that determine the critical temperatures of the BKT transition as well as that of the onset of long-range order. Further, we perform stochastic series expansion quantum Monte Carlo simulations based on the experimentally determined model parameters. Finite-size scaling of the in-plane spin stiffness yields excellent agreement of critical temperatures between theory and experiment, providing clear evidence that the nonmonotonic magnetic phase diagram of [Cu(pz)_{2}(2-HOpy)_{2}](PF_{6})_{2} is determined by the field-tuned XY anisotropy and the concomitant BKT physics.

Microscopic Study of the Fulde-Ferrell-Larkin-Ovchinnikov State in an All-Organic Superconductor.

Quasi-two-dimensional superconductors with a sufficiently weak interlayer coupling allow magnetic flux to penetrate in the form of Josephson vortices for in-plane applied magnetic fields. A consequence is the dominance of the Zeeman interaction over orbital effects. In the clean limit, the normal state is favored over superconductivity for fields greater than the paramagnetic limiting field, unless an intermediate, inhomogeneous state is stabilized. Presented here are nuclear magnetic resonance (NMR) studies of the inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state for ß''-(ET)2SF5CH2CF2SO3. The uniform superconductivity-FFLO transition is identified at an applied field value of 9.3(0.1) T at low temperature (T=130 mK), and evidence for a possible second transition between inhomogeneous states at ∼11 T is presented. The spin polarization distribution inferred from the NMR absorption spectrum compares favorably to a single-Q modulation of the superconducting order parameter.

Vitamin D is not linked to folate status and mRNA expression of intestinal proton-coupled folate transporter.

PURPOSE: In vitro studies discovered intestinal proton-coupled folate transporter (PCFT) as a vitamin D hormone-responsive gene. In vivo effects of vitamin D on PCFT and folate status are currently not available. METHODS: Three experiments were conducted. At first, vitamin D receptor knockout (VDR(-/-)) mice and corresponding wild-type (WT) mice were compared for their plasma and hepatic folate concentration and PCFT mRNA expression in intestinal mucosa. In a second experiment with rats, we analyzed the folate status of offspring in response to a maternal vitamin D-adequate (1,000 IU/kg) or vitamin D-deficient (0 IU/kg) diet that was fed for 11 weeks. Finally, the plasma folate concentration of healthy individuals was studied at baseline (in winter) and in response to an oral treatment for 8 weeks with 2,000 IU vitamin D3 per day or a placebo, respectively. RESULTS: Here, we show that folate status and intestinal PCFT mRNA abundance did not differ between the VDR(-/-) and the WT mice. No effect of vitamin D on folate status was also found in rat dams and their offspring, and plasma folate levels of individuals did not change in response to vitamin D. CONCLUSIONS: Current data from studies with model animals and humans provide no indication for a vitamin D effect on intestinal uptake and status of folate.

Monovacancy paramagnetism in neutron-irradiated graphite probed by 13C NMR.

We report on the magnetic properties of monovacancy defects in neutron-irradiated graphite, probed by 13C nuclear magnetic resonance spectroscopy. The bulk paramagnetism of the defect moments is revealed by the temperature dependence of the NMR frequency shift and spectral linewidth, both of which follow a Curie behavior, in agreement with measurements of the macroscopic magnetization. Compared to pristine graphite, the fluctuating hyperfine fields generated by the defect moments lead to an enhancement of the 13C nuclear spin-lattice relaxation rate [Formula: see text] by about two orders of magnitude. With an applied magnetic field of 7.1 T, the temperature dependence of [Formula: see text] below about 10 K can well be described by a thermally activated form, [Formula: see text], yielding a singular Zeeman energy of ([Formula: see text]) meV, in excellent agreement with the sole presence of polarized, non-interacting defect moments.

NMR shift and relaxation measurements in pulsed high-field magnets up to 58T.

Nuclear magnetic resonance (NMR) experiments at fields up to 58T in pulsed magnets at the Dresden High Magnetic Field Laboratory are reported. The challenge to resolve NMR shifts in these time-dependent fields is addressed for the first time, and it is shown that this can indeed be accomplished with high precision with an internal reference. As a result, signal averaging is possible during a single magnetic field pulse, but also for multiple pulses. Thus, even very weak signals can in principle be recorded and their shifts can be determined. In a second set of experiments, the measurement of nuclear relaxation is investigated. Using adiabatic inversion with the inherent time dependence of the magnetic field and small-angle inspection, it is shown that relaxation measurements are possible, as well. The shift experiments were performed with (27)Al NMR on a mixture of aluminum metal and a Linde type A zeolite. For the relaxation studies, (27)Al NMR and (69)Ga NMR on the metals aluminum and gallium were preformed, respectively.

Field-stepped broadband NMR in pulsed magnets and application to SrCu2(BO3)2 at 54T.

Pulsed magnets generate the highest magnetic fields as brief transients during which the observation of NMR is difficult, however, this is the only route to unique insight into material properties up to the regime of 100T. Here, it is shown how rather broad NMR spectra can be assembled in a pulsed magnet during a single field pulse by using the inherent time dependence of the field for the recording of field-stepped free induction decays that cover a broad frequency range. The technique is then applied to (11)B NMR of the spin-dimer system SrCu2(BO3)2, a magnetic insulator known to undergo a series of field-driven changes of the magnetic ground state. At peak fields of about 54T at the Dresden High Magnetic Field Laboratory, (11)B NMR spectra spanning a total of about 9MHz width are reconstructed. The results are in good accordance with a change from a high-temperature paramagnetic state to a low-temperature commensurate superstructure of field-induced spin-dimer triplets.

[Unclear per anum bleeding during pregnancy]. / Unklare peranale Blutung in der Schwangerschaft.

A 30-year-old, 7-months pregnant woman presented with per anum bleeding. Rectoscopy showed the cause to be a polyp the size of a fingertip 9 cm from the anus. Since the bleeding stopped spontaneously and therefore the need for radical intervention, and due to the advanced pregnancy stage, no biopsy was done. About 1 year later, the same patient experienced sharp pains and anal bleeding during defecation. A poorly defined neuroendocrine carcinoma was diagnosed. Seeking a prognosis optimal for the newborn child, the interdisciplinary decision was made for primary surgery with adjuvant chemotherapy. Other options for this malignancy during and after pregnancy are also discussed.

Hypochlorite-modified low-density lipoprotein stimulates human polymorphonuclear leukocytes for enhanced production of reactive oxygen metabolites, enzyme secretion, and adhesion to endothelial cells.

Hypochlorite-oxidized low-density lipoprotein ((-)OCl-LDL) has been shown to stimulate various functions of human polymorphonuclear leukocytes (PMNLs). Incubation of PMNLs with (-)OCl-LDL (produced by incubation of 0.4 mM LDL cholesterol with 1 mM NaOCl for 40 min at 37 degrees C) but not native or copper-oxidized LDL induced a substantial generation of reactive oxygen species (ROS) as measured by means of chemiluminescence with one peak at 10-12 min. Upon stimulation with (-)OCl-LDL about 70% of ROS (hydrogen peroxide and superoxide anion) were released from the cells into the extracellular environment. The (-)OCl-LDL-induced increase of the respiratory burst was dependent upon the dose, exposure time, and extent of LDL oxidation. Cytochalasin B, an inhibitor of phagocytosis, markedly diminished the LDL-induced ROS generation to nearly 40% of control values. (-)OCl-LDL enhanced the adhesion of PMNLs to human umbilical venous endothelial cells 2.5-fold as compared to native LDL and promoted the secretion of the active granule enzymes lysozyme and beta-glucuronidase. Together, the results suggest a potential role of LDL-activated PMNLs in initiating and/or maintaining the inflammatory process during the early phase of atherosclerotic lesion development. Alternatively, PMNLs may also play a protective role by phagocytosing oxidized LDL and, thus, preventing further detrimental atherogenic effects of oxidized LDL.

The risk of pancreaticointestinal anastomosis can be predicted preoperatively.

The risk of developing postoperative complications following pancreatic resection depends mainly on how difficult it is to perform a proper pancreaticointestinal anastomosis. We have evaluated the serum pancreolauryl test, a rapid tubeless pancreatic function test, as a simple preoperative predictor of the degree of pancreatic fibrosis. Degree of fibrosis in turn provides an indirect parameter for the difficulties of performing a proper and safe pancreaticointestinal anastomosis. In 35 patients (21 chronic pancreatitis, 14 pancreatic tumors) undergoing major pancreatic resection, we found a negative correlation (r = -0.75, p < 0.001) between the degree of fibrosis at the resection margin and the serum pancreolauryl test results. Patients with chronic pancreatitis had a significantly higher degree of fibrosis at the resection margin (59 +/- 22 vs. 34 +/- 25%; X +/- SD; p < 0.01) and lower fluorescein serum concentrations (2.6 +/- 1.9 vs. 4.3 +/- 2.1 micrograms/ml; X +/- SD; p < 0.01) in comparison with patients with pancreatic tumors. These findings indicate that the degree of pancreatic fibrosis, the difficulties of performing a proper pancreaticointestinal anastomosis, and subsequently the potential risk of postoperative complications can easily be predicted preoperatively.

Use of EPR spectroscopy to study macromolecular structure and function.

Electron paramagnetic resonance (EPR) spectroscopy is now part of the armory available to probe the structural aspects of proteins, nucleic acids and protein-nucleic acid complexes. Since the mobility of a spin label covalently attached to a macromolecule is influenced by its microenvironment, analysis of the EPR spectra of site-specifically incorporated spin labels (probes) provides a powerful tool for investigating structure-function correlates in biological macromolecules. This technique has become readily amenable to address various problems in biology in large measure due to the advent of techniques like site-directed mutagenesis, which enables site-specific substitution of cysteine residues in proteins, and the commercial availability of thiol-specific spin-labeling reagents (Figure 1). In addition to the underlying principle and the experimental strategy, several recent applications are discussed in this review.

Comparisons in good and bad: criminality in Japan and Germany.

In the field of criminological comparison, Japan and Germany are very suitable subjects. A nearly identical penal law and a social structure of highly developed industrial societies after a complete destruction at the end of World War War II give a good match. At first sight, Japan's crime rate is less than 1/4 of that in Germany. The impact of organised crime on the reduction of general crime is discussed.

Effect of intravenous enkephalin administration on kallikrein-kinin system in experimental hemorrhagic shock. Evidence for activation of kallikrein-kinin system by naloxone.

The effects of enkephalin derivates with different opioid receptor subtype specificity and naloxone on cardiovascular responses and kallikrein-kinin system (KKS) were studied in anesthetized rats exposed to 30% hemorrhage. Administration of a mu-receptor agonist (DAGO) in early hemorrhage improved mean arterial blood pressure (MAP) responses to hemorrhage. This effect could be abolished by naloxone pretreatment. Moreover, a delayed MAP recovery after hemorrhage could be observed. Treatment with a delta-agonist (DADL) resulted in transient depression of MAP and heart rate (HR). Hemorrhage by itself caused only a slight activation of KKS as indicated by decreased plasma kallikreinogen concentration and reduced kallikrein inhibitor capacity after 20% blood loss. Enkephalin administration did not exert significant effects on KKS. Naloxone pretreatment, in contrast, induced prehemorrhagic activation of KKS, which was potentiated by subsequent hemorrhage. Naloxone-induced activation of KKS could be confirmed by an in vitro study. Taken together these results suggest that the KKS is not involved in MAP and HR responses to enkephalin administration during hemorrhage, whereas it might be implicated in naloxone-induced delayed posthemorrhagic MAP recovery.

[Selenium administration in patients with sepsis syndrome. A prospective randomized study]. / Selensubstitution bei Sepsispatienten. Eine prospektiv randomisierte Studie.

PATIENTS AND METHOD: In this study the effect of antioxidative therapy with sodium selenite was investigated in patients with systemic inflammatory response syndrome (S. I. R. S.) and multiple organ failure. 40 patients were included in this prospective randomized study. The patients were observed over a period of 28 days. The letality rate within 28 days was excepted as main criteria. The Apache-II and the MOF-Score of Goris were used as clinical parameters. 20 patients were treated with sodium selenite over a period of 28 days. RESULT: This antioxidative therapy reduced the letality rate from 40 to 15%.

[The effect of agonists and antagonists of opiate receptors on the activity of the kallikrein-kinin system in hemorrhagic shock]. / Vliianie agonistov i antagonistov opiatnykh retseptorov na aktivnost' kallikrein-kininovoi sistemy pri gemorragicheskom shoke.

Mean blood pressure and heart rate have been registered in the experiments on male Wistar rats. Kallikrein-kinin system (KKS) components have been evaluated in blood plasma: plasma kallikreinogen, kallikrein-inhibiting capacity, spontaneous esterase activity. The parameters were determined before and after hemorrhage in the volume accounting for 10, 20 and 30% of the circulating blood volume. The rats were administered enkephalin analogues--DAGO, DADL and naloxone. The administration of mu-agonist DAGO improved hemodynamics. DAGO effect was eliminated by naloxone. The administration of enkephalins did not affect KKS parameters, while naloxone potentiated KKS changes induced by hemorrhage. It has been shown that KKS is not involved into the mechanism of hemodynamic changes in response to enkephalin administration during hemorrhagic shock.

[Otto J"ungling--the first "specialist in anesthesiology" in Berlin]. / Otto Jüngling--der erste "Facharzt für Anaesthesiologie" in Berlin.

Compared to English-speaking countries, anaesthesiology in Germany developed into an independent field relatively late. German doctors were sent abroad to other European countries to learn modern anaesthetic techniques. At the beginning of the fifties, colleagues from East Germany had increasing problems to travel abroad. Otto Jüngling, who specialised in anaesthesiology in Vienna under Otto Mayrhofer, came with a work permit to the small town of Quedlinburg in the Harz mountains in November 1952. One year later, in September 1953, he went to Berlin to set up a new department of anaesthesiology at Friedrichshain Hospital. After recognition of his speciality by the Austrian General Medical Council in Linz, Otto Jüngling became the first specialist for anaesthesiology to practise in Berlin. Scientifically he worked on the development of new anaesthetics and anaesthetic machines. A transportable suction unit was one of his excellent ideas. Furthermore, he rendered outstanding services to the training of anaesthesists in Berlin. Otto Jüngling resigned in February 1959 due to unsatisfactory cooperation with public authorities and went back to Austria were he lives today as a pensioner.

[The activity of several dehydrogenases in both hemispheres of the hippocampus from rats during some phases of postnatal development (author's transl)]. / Zum Aktivierungsverhalten einiger Dehydrogenasen in den beiden Hippocampus-Hemisphären von Wistar-Ratten während verschiedener Postnatalstadien.

The activities of lactate dehydrogenase, succinate dehydrogenase and glutamate dehydrogenase, originating from rat hippocampus were determined 3, 10, 20 and 40 days post partum. Hemispheric asymmetry was tested using tetrazolium salt MTT-bromide and the elution technique. It could be revealed that significant differences between enzymatic activities occur between both hemispheres of the hippocampus. The greatest difference observed was 14%. Our dates show that a predominantly left-side dominance takes place in the hippocampus.

[Neonatal risk in early manifested maternal diabetes]. / Das neonatale Risiko bei frühmanifestiertem mütterlichem Diabetes.

Neonatal risk in 172 women with early manifested maternal diabetes mellitus (manifestation less than or equal to 18 years) has been estimated in an analysis of 10 years. We found a tendency towards an increased rate of mortality and malformations, but there are no statistic significant differences compared with the White B group as well as with the C/D-group of late manifestation. An increased risk of morbidity (rate of fetopathy , immaturity, disturbed adaptation) could be demonstrated, but it exists also in the newborns of diabetic mothers of the White group B. Using the recent literature the causes have been discussed and conclusions have been made.

[Gestation in early onset diabetes mellitus]. / Gestation bei frühmanifestem Diabetes mellitus.

Report about the gestation of 172 diabetic patients with manifestation of disturbance of carbohydrate metabolism in childhood or adolescence (Group White C and D early manifestation) based on a ten years experience. Relating to age of menarche, behaviour of menstrual cycle and course of pregnancy no significant difference could be found in comparison to 454 other diabetic patients delivered in the same clinic. Only the frequency of obstetrics operations of more than 50 per cent was higher significantly.