Longitudinal Spin Fluctuations Driving Field-Reinforced Superconductivity in UTe_{2}

Our measurements of ^{125}Te NMR relaxations reveal an enhancement of electronic spin fluctuations above μ_{0}H^{*}∼15  T, leading to their divergence in the vicinity of the metamagnetic transition at μ_{0}H_{m}≈35  T, below which field-reinforced superconductivity appears when a magnetic field (H) is applied along the crystallographic b axis. The NMR data evidence that these fluctuations are dominantly longitudinal, providing a key to understanding the peculiar superconducting phase diagram in H∥b, where such fluctuations enhance the pairing interactions.

Detection of a Disorder-Induced Bose-Einstein Condensate in a Quantum Spin Material at High Magnetic Fields

The coupled spin-1 chains material NiCl_{2}-4SC(NH_{2})_{2} (DTN) doped with Br impurities is expected to be a perfect candidate for observing many-body localization at high magnetic field: the so-called "Bose glass," a zero-temperature bosonic fluid, compressible, gapless, incoherent, and short-range correlated. Using nuclear magnetic resonance, we critically address the stability of the Bose glass in doped DTN, and find that it hosts a novel disorder-induced ordered state of matter, where many-body physics leads to an unexpected resurgence of quantum coherence emerging from localized impurity states. An experimental phase diagram of this new "order-from-disorder" phase, established from nuclear magnetic resonance T_{1}^{-1} relaxation rate data in the 13±1% Br-doped DTN, is found to be in excellent agreement with the theoretical prediction from large-scale quantum Monte Carlo simulations.

Gonadotropin Levels in Ovarian Cyst Fluids: A Predictor of Malignancy?

Gonadotropins can stimulate ovarian cancer growth in cell cultures. Corresponding LH/hCG receptors have been demonstrated in ovarian cancer. However, reduction of elevated serum gonadotropins by GnRH analogs in ovarian cancer patients did not lead to growth restriction, which means that serum levels of gonadotropins may not play the most important role in ovarian cancer. We therefore analyzed the LH and FSH concentrations in cyst fluids of ovarian cancer. Patients with preoperatively diagnosed cystic ovarian tumors were eligible for the study. Serum samples of the patients were obtained during surgery, while the fluids within the cysts were aspirated after surgical removal of the tumor. FSH and LH levels in serum and cyst fluids were measured using single antibody EIA (Boehringer Mannheim GmbH, Germany). Cyst fluids and sera of 108 patients were evaluated. While there were no significant differences in the FSH and LH serum concentrations, highly significant differences in the FSH and LH levels in cyst fluids were found. Only cancer cysts contained FSH and LH, while the corresponding concentrations in benign cysts were always below the measuring range of the assays. This clear division between high gonadotropin levels in cysts of serous ovarian cancer and low or absent concentrations in benign ovarian tumors further supports the hypothesis that FSH and LH may play a role in ovarian cancer; however, explanations for this surprising finding are still lacking.

Nuclear Magnetic Resonance Signature of the Spin-Nematic Phase in LiCuVO_{4} at High Magnetic Fields

We report a ^{51}V nuclear magnetic resonance investigation of the frustrated spin-1/2 chain compound LiCuVO_{4}, performed in pulsed magnetic fields and focused on high-field phases up to 56 T. For the crystal orientations H∥c and H∥b, we find a narrow field region just below the magnetic saturation where the local magnetization remains uniform and homogeneous, while its value is field dependent. This behavior is the first microscopic signature of the spin-nematic state, breaking spin-rotation symmetry without generating any transverse dipolar order, and is consistent with theoretical predictions for the LiCuVO_{4} compound.

Renoprotection: focus on TRPV1, TRPV4, TRPC6 and TRPM2

Members of the transient receptor potential (TRP) cation channel receptor family have unique sites of regulatory function in the kidney which enables them to promote regional vasodilatation and controlled Ca²⁺ influx into podocytes and tubular cells. Activated TRP vanilloid 1 receptor channels (TRPV1) have been found to elicit renoprotection in rodent models of acute kidney injury following ischaemia/reperfusion. Transient receptor potential cation channel, subfamily C, member 6 (TRPC6) in podocytes is involved in chronic proteinuric kidney disease, particularly in focal segmental glomerulosclerosis (FSGS). TRP vanilloid 4 receptor channels (TRPV4) are highly expressed in the kidney, where they induce Ca²⁺ influx into endothelial and tubular cells. TRP melastatin (TRPM2) non-selective cation channels are expressed in the cytoplasm and intracellular organelles, where their inhibition ameliorates ischaemic renal pathology. Although some of their basic properties have been recently identified, the renovascular role of TRPV1, TRPV4, TRPC6 and TRPM2 channels in disease states such as obesity, hypertension and diabetes is largely unknown. In this review, we discuss recent evidence for TRPV1, TRPV4, TRPC6 and TRPM2 serving as potential targets for acute and chronic renoprotection in chronic vascular and metabolic disease.

Quasiparticle Scattering off Defects and Possible Bound States in Charge-Ordered YBa_{2}Cu_{3}O_{y}

We report the NMR observation of a skewed distribution of ^{17}O Knight shifts when a magnetic field quenches superconductivity and induces long-range charge-density-wave (CDW) order in YBa_{2}Cu_{3}O_{y}. This distribution is explained by an inhomogeneous pattern of the local density of states N(E_{F}) arising from quasiparticle scattering off, yet unidentified, defects in the CDW state. We argue that the effect is most likely related to the formation of quasiparticle bound states, as is known to occur, under specific circumstances, in some metals and superconductors (but not in the CDW state, in general, except for very few cases in 1D materials). These observations should provide insight into the microscopic nature of the CDW, especially regarding the reconstructed band structure and the sensitivity to disorder.

Dichotomy between Attractive and Repulsive Tomonaga-Luttinger Liquids in Spin Ladders

We present a direct NMR method to determine whether the interactions in a Tomonaga-Luttinger liquid (TLL) state of a spin-1/2 Heisenberg antiferromagnetic ladder are attractive or repulsive. For the strong-leg spin ladder compound (C_{7}H_{10}N)_{2}CuBr_{4} we find that the isothermal magnetic field dependence of the NMR relaxation rate T_{1}^{-1}(H) displays a concave curve between the two critical fields bounding the TLL regime. This is in sharp contrast to the convex curve previously reported for a strong-rung ladder, (C_{5}H_{12}N)_{2}CuBr_{4}. We show that the concavity and the convexity of T_{1}^{-1}(H), which is a fingerprint of spin fluctuations, directly reflect the attractive and repulsive fermionic interactions in the TLL, respectively. The interaction sign is alternatively determined from an indirect method combining bulk magnetization and specific heat data.

Reentrant superconductivity driven by quantum tricritical fluctuations in URhGe: evidence from ^{59}Co NMR in URh_{0.9}Co_{0.1}Ge

Our measurements of the ^{59}Co NMR spin-spin relaxation in URh_{0.9}Co_{0.1}Ge reveal a divergence of electronic spin fluctuations in the vicinity of the field-induced quantum critical point at H_{R}≈13  T, around which reentrant superconductivity (RSC) occurs in the ferromagnetic heavy fermion compound URhGe. We map out the strength of spin fluctuations in the (H_{b},H_{c}) plane of magnetic field components and show that critical fluctuations develop in the same limited region near the field H_{R} as that where RSC is observed. This strongly suggests these quantum fluctuations as the pairing glue responsible for the RSC. The fluctuations observed are characteristic of a tricritical point, followed by a phase bifurcation toward quantum critical end points.

Principles of reconstruction with tissue expanders as immediate reconstruction after mastectomy for breast cancer

The aim of reconstruction with expanders is to restore breast shape and volume as close as possible to the contralateral breast and to reconstruct the inframammary fold with adequate ptosis.

Direct measurement of the upper critical field in cuprate superconductors

In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+δ, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competition-associated with Fermi-surface reconstruction and charge-density-wave order-is a key limiting factor in the superconductivity of cuprates.

The incidence of ulnocarpal complaints after distal radial fracture in relation to the fracture of the ulnar styloid

Two hundred distal radial fractures, with a mean follow up of 20 months (range 6-49), were divided into three groups according to the presence and healing status of an ulnar styloid fracture. The patients underwent both clinical and radiological examination and completed two different questionnaires. One hundred and one, of 200 distal radial fractures, were associated with an ulnar styloid fracture. Forty-six of these developed an ulnar styloid nonunion. The authors encountered significantly higher pain scores (ulnar sided pain p = 0.012), a higher rate of DRUJ instability (p = 0.032), a greater loss of motion and grip strength (p = 0.001), and a poorer clinical outcome in cases with an ulnar styloid fracture, but no differences were apparent when those with healed ulnar styloid fractures or ulnar styloid nonunions were compared (p > 0.05). The investigators propose that the incidence of ulnocarpal complaints following distal radial fracture depends on the presence but not the healing status of an ulnar styloid fracture.

Microscopic properties of the pinwheel kagome compound Rb(2)Cu(3)SnF(12)

Using (63,65)Cu nuclear magnetic resonance in magnetic fields up to 30 T, we study the microscopic properties of the 12-site valence-bond-solid ground state in the "pinwheel" kagome compound Rb(2)Cu(3)SnF(12). We find that the ground state is characterized by a strong transverse staggered spin polarization whose temperature and field dependence points to a mixing of the singlet and triplet states. This is further corroborated by the field dependence of the gap Δ(H), which has a level anticrossing with a large minimum gap value of ≈ Δ(0)/2, with no evidence of a phase transition down to 1.5 K. By the exact diagonalization of small clusters, we show that the observed anticrossing is mainly due to staggered tilts of the g tensors defined by the crystal structure and reveal symmetry properties of the low-energy excitation spectrum compatible with the absence of level crossing.

Field-induced quantum soliton lattice in a frustrated two-leg spin-1/2 ladder

Based on high-field (31)P nuclear magnetic resonance experiments and accompanying numerical calculations, it is argued that in the frustrated S=1/2 ladder compound BiCu(2)PO(6) a field-induced soliton lattice develops above a critical field of μ(0)H(c1)=20.96(7) T. Solitons result from the fractionalization of the S=1, bosonlike triplet excitations, which in other quantum antiferromagnets are commonly known to experience Bose-Einstein condensation or to crystallize in a superstructure. Unlike in spin-Peierls systems, these field-induced quantum domain walls do not arise from a state with broken translational symmetry and are triggered exclusively by magnetic frustration. Our model predicts yet another second-order phase transition at H(c2)>H(c1), driven by soliton-soliton interactions, most likely corresponding to the one observed in recent magnetocaloric and other bulk measurements.

Incomplete devil's staircase in the magnetization curve of SrCu2(BO3)2

We report on NMR and torque measurements on the frustrated quasi-two-dimensional spin-dimer system SrCu(2)(BO(3))(2) in magnetic fields up to 34 T that reveal a sequence of magnetization plateaus at 1/8, 2/15, 1/6, and 1/4 of the saturation and two incommensurate phases below and above the 1/6 plateau. The magnetic structures determined by NMR involve a stripe order of triplets in all plateaus, suggesting that the incommensurate phases originate from proliferation of domain walls. We propose that the magnetization process of SrCu(2)(BO(3))(2) is best described as an incomplete devil's staircase.

Continuous spinal anesthesia versus continuous femoral nerve block for elective total knee replacement

BACKGROUND

Continuous spinal analgesia (CSA) and continuous femoral nerve blockade (CFNB) are well-established procedures for postoperative pain relief. This study compares the efficacy, adverse effects and complications associated with these two analgesic methods in patients undergoing total knee arthroplasty (TKA).

METHODS

Data were analyzed from consecutive patients undergoing TKA under either CSA or spinal anesthesia plus CFNB. Quality of analgesia was assessed based on opioid consumption and pain intensity (visual analogue scale [VAS] where 0=no pain and 10=utmost imaginable pain) until postoperative day 4. In addition, joint mobility was assessed, and any adverse reactions or side effects were noted.

RESULTS

Sixty-two patients had satisfactory postoperative pain relief, and maximum pain scores were reported between 12 and 24 hrs. Median pain scores in the CSA group were significantly lower than those in the CFNB group (1.0 [0.9-1.9] vs. 2.0 [1.5-3.6] for resting pain and 2.0 [1.7-3.1] vs. 5.0 [3.0-5.5] for dynamic pain, respectively; P<0.001 for days 0 and 1; P<0.05 for all other days). Piritramide consumption was significantly higher in the CFNB group (P<0.01). There were no significant differences between the groups for postoperative mobility of the joint or patient satisfaction.

CONCLUSION

Both methods demonstrated analgesic efficacy after total knee arthroplasty, although there was less pain severity and opioid consumption use reported with continuous spinal analgesia. However, the use of continuous spinal analgesia is limited by concerns about the risk profile and absence of approved devices for continuous intrathecal infusion.

Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain

Previous studies have shown that engineered nanomaterials can be transferred from prey to predator, but the ecological impacts of this are mostly unknown. In particular, it is not known if these materials can be biomagnified-a process in which higher concentrations of materials accumulate in organisms higher up in the food chain. Here, we show that bare CdSe quantum dots that have accumulated in Pseudomonas aeruginosa bacteria can be transferred to and biomagnified in the Tetrahymena thermophila protozoa that prey on the bacteria. Cadmium concentrations in the protozoa predator were approximately five times higher than their bacterial prey. Quantum-dot-treated bacteria were differentially toxic to the protozoa, in that they inhibited their own digestion in the protozoan food vacuoles. Because the protozoa did not lyse, largely intact quantum dots remain available to higher trophic levels. The observed biomagnification from bacterial prey is significant because bacteria are at the base of environmental food webs. Our findings illustrate the potential for biomagnification as an ecological impact of nanomaterials.

[Prolonged fever and monocytosis after hemorrhoidectomy and treatment with methotrexate--listeriosis with cerebral abscess]

HISTORY AND CLINICAL FINDINGS

A 58-year-old man was admitted because of septic fever for about one week with onset two weeks after an hemorrhoidectomy. He had been receiving methotrexate (MTX) since boyhood for severe psoriasis. Fifteen years before he had undergone a splenectomy after abdominal trauma. The patient was found to have diminished cognitive functions and memory disturbance, but no focal neurological deficits.

INVESTIGATIONS

Laboratory tests were negative for inflammatory disease (normal white blood cell count, CRP and procalcitonin) and serial blood cultures remained sterile. Cranial computed tomography (CCT), done because viral encephalitis was suspected, revealed a large focus in the left hemisphere, further identified as abscess on magnetic imaging.

TREATMENT AND COURSE

The patient's fever subsided within two days of treatment with ampicillin and ciprofloxacin. The patient was sent to the department of neurosurgery for further diagnosis. Stereotactic biopsy revealed Listeria monocytogenes. Antibiotic treatment was modified in accordance with the microbiological results and the patient was transferred to a rehabilitation unit.

CONCLUSIONS

Lack of pathological levels of CRP, procalcitonin and white blood cell count does not exclude cerebral abscess in a patient with prolonged fever and without marked neurological deficits. Preceding treatment with immunosuppressive drugs, especially MTX, and failing response to cephalosporins should lead to consideration of listeriosis in the differential diagnosis.

Spin configuration in the 1/3 magnetization plateau of azurite determined by NMR

High magnetic field (63,65)Cu NMR spectra were used to determine the local spin polarization in the 1/3 magnetization plateau of azurite, Cu3(CO3)(2)(OH)(2), which is a model system for the distorted diamond antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the Cu2 (dimer) sites is found to be field independent, negative and strongly anisotropic, corresponding to approximately 10% of fully polarized spin in a d orbital. This is close to the expected configuration of the quantum plateau, where a singlet state is stabilized on the dimer. However, the observed nonzero spin polarization points to some triplet admixture, induced by strong asymmetry of the diamond bonds J1 and J3.

Improved radar data processing algorithms for quantitative rainfall estimation in real time

This paper describes a new methodology to process C-band radar data for direct use as rainfall input to hydrologic and hydrodynamic models and in real time control of urban drainage systems. In contrast to the adjustment of radar data with the help of rain gauges, the new approach accounts for the microphysical properties of current rainfall. In a first step radar data are corrected for attenuation. This phenomenon has been identified as the main cause for the general underestimation of radar rainfall. Systematic variation of the attenuation coefficients within predefined bounds allows robust reflectivity profiling. Secondly, event specific R-Z relations are applied to the corrected radar reflectivity data in order to generate quantitative reliable radar rainfall estimates. The results of the methodology are validated by a network of 37 rain gauges located in the Emscher and Lippe river basins. Finally, the relevance of the correction methodology for radar rainfall forecasts is demonstrated. It has become clearly obvious, that the new methodology significantly improves the radar rainfall estimation and rainfall forecasts. The algorithms are applicable in real time.

[Endovascular therapy of infrarenal aortic aneurysms: preinterventional imaging and follow-up]

Imaging plays an important role in the selection of patients with infrarenal aortic aneurysms suitable for interventional therapy and preinterventional workup. It is also an important tool for follow-up after stent-graft placement. Cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow the delineation of the vessel lumen and side branches. Modern postprocessing techniques permit precise measurement of aneurysm properties such as the length and diameter of the proximal and distal neck and the length and diameter of the aneurysm. Evaluation of the access vessel is also possible. During follow-up after stent-graft placement, it is important to detect possible endoleaks and further growth of the aneurysm sac. Furthermore fractures of the stent struts, migration of the stent, and in-stent thrombosis must to be detected. This review provides an overview of the pros and cons of the different imaging modalities in pre- and postinterventional studies. In addition the most important criteria for the exclusion of infrarenal aortic aneurysms and for patient follow-up are presented.