Evidence of an Improper Displacive Phase Transition in Cd_{2}Re_{2}O_{7} via Time-Resolved Coherent Phonon Spectroscopy.

We have used a combination of ultrafast coherent phonon spectroscopy, ultrafast thermometry, and time-dependent Landau theory to study the inversion symmetry breaking phase transition at T_{c}=200 K in the strongly spin-orbit coupled correlated metal Cd_{2}Re_{2}O_{7}. We establish that the structural distortion at T_{c} is a secondary effect through the absence of any softening of its associated phonon mode, which supports a purely electronically driven mechanism. However, the phonon lifetime exhibits an anomalously strong temperature dependence that decreases linearly to zero near T_{c}. We show that this behavior naturally explains the spurious appearance of phonon softening in previous Raman spectroscopy experiments and should be a prevalent feature of correlated electron systems with linearly coupled order parameters.

A parity-breaking electronic nematic phase transition in the spin-orbit coupled metal Cd2Re2O7.

Strong electron interactions can drive metallic systems toward a variety of well-known symmetry-broken phases, but the instabilities of correlated metals with strong spin-orbit coupling have only recently begun to be explored. We uncovered a multipolar nematic phase of matter in the metallic pyrochlore Cd2Re2O7 using spatially resolved second-harmonic optical anisotropy measurements. Like previously discovered electronic nematic phases, this multipolar phase spontaneously breaks rotational symmetry while preserving translational invariance. However, it has the distinguishing property of being odd under spatial inversion, which is allowed only in the presence of spin-orbit coupling. By examining the critical behavior of the multipolar nematic order parameter, we show that it drives the thermal phase transition near 200 kelvin in Cd2Re2O7 and induces a parity-breaking lattice distortion as a secondary order.

Strain Control of Fermiology and Many-Body Interactions in Two-Dimensional Ruthenates.

Here we demonstrate how the Fermi surface topology and quantum many-body interactions can be manipulated via epitaxial strain in the spin-triplet superconductor Sr_{2}RuO_{4} and its isoelectronic counterpart Ba_{2}RuO_{4} using oxide molecular beam epitaxy, in situ angle-resolved photoemission spectroscopy, and transport measurements. Near the topological transition of the γ Fermi surface sheet, we observe clear signatures of critical fluctuations, while the quasiparticle mass enhancement is found to increase rapidly and monotonically with increasing Ru-O bond distance. Our work demonstrates the possibilities for using epitaxial strain as a disorder-free means of manipulating emergent properties, many-body interactions, and potentially the superconductivity in correlated materials.

High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position-sensitive detection.

We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position-sensitive detector. The high rotational speed of the technique, 10(3) to 10(4) times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser-power, beam-pointing, and pulse-width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk fourfold rotational symmetry of GaAs about its [001] axis using second-harmonic generation.

Quasiparticle mass enhancement and temperature dependence of the electronic structure of ferromagnetic SrRuO3 thin films.

We report high-resolution angle-resolved photoemission studies of epitaxial thin films of the correlated 4d transition metal oxide ferromagnet SrRuO(3). The Fermi surface in the ferromagnetic state consists of well-defined Landau quasiparticles exhibiting strong coupling to low-energy bosonic modes which contributes to the large effective masses observed by transport and thermodynamic measurements. Upon warming the material through its Curie temperature, we observe a substantial decrease in quasiparticle coherence but negligible changes in the ferromagnetic exchange splitting, suggesting that local moments play an important role in the ferromagnetism in SrRuO(3).

Severe trauma of the chest wall: surgical rib stabilisation versus non-operative treatment.

BACKGROUND: Serial rib fractures and flail chest injury can be treated by positive-pressure ventilation. Operative techniques reduce intensive care unit (ICU) stay, overall costs, mortality and morbidity, as well as pain. The aim of this study was to evaluate the benefit of surgical rib stabilisation in comparison to non-operative treatment in patients with severe trauma of the chest wall. MATERIALS AND METHODS: From 2006 to 2011, the data of 44 patients with flail chest and serial rib fractures were collected retrospectively. A surgical group and an intensive care group with only intensive care therapy were formed. Rib and sternal fractures, flail chest, injury severity, thoracic injuries, mechanical ventilation, time in the ICU, overall hospital stay and mortality were evaluated. RESULTS: No postoperative surgical complications had been observed. The time under mechanical ventilation in the surgical group was 10.6 ± 10.2 days, whereas in the non-surgical group, it was 13.7 ± 13.7 days. Mechanical ventilation time after surgery was 6.9 ± 6.5 days. Time in the ICU for the surgical group was 16.4 ± 13.6 days, compared to the non-surgical group with 20.1 ± 16.2 days. Postoperative time in the ICU was 11.7 ± 10.3 days. The mortality in the surgical group was 10 % and in the non-surgical group it was 17 %. CONCLUSIONS: Operative rib stabilisation with plates is a safe therapy option for severe trauma of the chest wall. Provided that the duration of preoperative mechanical ventilation and time spent in the ICU is minimised due to early operation, our data suggest that the stabilisation of serial rib fractures and flail chest may lead to a reduced time of mechanical ventilation, time in the ICU and mortality.

Temperature dependence of the electronic structure and Fermi-surface reconstruction of Eu(1-x)Gd(x)O through the ferromagnetic metal-insulator transition.

We present angle-resolved photoemission spectroscopy of Eu(1-x)Gd(x)O through the ferromagnetic metal-insulator transition. In the ferromagnetic phase, we observe Fermi surface pockets at the Brillouin zone boundary, consistent with density functional theory, which predicts a half-metal. Upon warming into the paramagnetic state, our results reveal a strong momentum-dependent evolution of the electronic structure, where the metallic states at the zone boundary are replaced by pseudogapped states at the Brillouin zone center due to the absence of magnetic long-range order of the Eu 4f moments.

Frozen section analysis for intraoperative margin assessment during breast-conserving surgery results in low rates of re-excision and local recurrence.

BACKGROUND: Negative surgical margins minimize the risk of local recurrence after breast-conserving surgery. Intraoperative frozen section analysis (FSA) is one method for margin evaluation. We retrospectively analyzed records of patients who received breast-conserving therapy with intraoperative FSA of the lumpectomy cavity to assess re-excision rates and local control. METHODS: Records were retrospectively reviewed for individuals who underwent breast-conserving surgery for ductal carcinoma in situ (DCIS) or invasive carcinoma between 1993 and 2003. Inclusion criteria were a minimum of 2 years follow-up and intact tumor at the time of operation. The major outcome measure was local recurrence. The Kaplan-Meier test was used to evaluate local recurrence rates between groups. RESULTS: 290 subjects with an average age of 57.2 years (range 27-89) underwent 292 lumpectomies with FSA. 11.3% had DCIS, 73.3% had infiltrating ductal, 5.8% had infiltrating lobular, and 9.6% exhibited other forms of invasive carcinoma. 70 subjects underwent additional resection at the time of breast surgery, 16 underwent subsequent re-excision, and 17 underwent subsequent mastectomy. At a median follow-up of 53.4 months (range 5.8-137.8), there were six local recurrences (2.74%) in patients who had breast-conserving procedures and two local recurrences in patients who underwent mastectomy. There were no statistically significant associations among local recurrence rate, tumor size, nodal status, or overall stage. Local recurrences were higher in patients with DCIS compared with invasive carcinoma, and tumors >2cm. CONCLUSIONS: Intraoperative FSA allows resection of suspicious or positive margins at the time of lumpectomy and results in low rates of local recurrence and re-excision. The low local recurrence rate reported here is comparable to those reported with other margin assessment techniques.

Fully integrated whole blood testing by real-time absorption measurement on a centrifugal platform.

We present a novel microfluidic concept to enable a fast colorimetric alcohol assay from a single droplet of whole blood. The reduced turn-around time of 150 seconds is, on the one hand, achieved by a full process integration including metering, mixing with reagents, and sedimentation of cellular constituents. On the other hand, our novel total internal reflection (TIR) scheme allows to monitor the increase of the absorbance values in real-time. Thus, the saturation values can be predicted accurately based on an extrapolation of real-time measurements acquired during a 100 second initial period of rotation. Additionally, we present a metering structure to define nanolitre sample volumes at a coefficient of variation (CV) below 5%.

Diclofenac-associated hepatotoxicity: analysis of 180 cases reported to the Food and Drug Administration as adverse reactions.

Diclofenac is a nonsteroidal anti-inflammatory drug approved in the United States in 1988 for the treatment of patients with osteoarthritis, rheumatoid arthritis, or ankylosing spondylitis. To characterize the clinical, biochemical, and histological features and possible mechanisms of hepatic injury associated with its use, a retrospective analysis was undertaken of 180 patients whose cases were reported to the Food and Drug Administration from November 1988 through June 1991, as having had possible adverse reactions to diclofenac. Of the reported 180 cases, 79% were female, 71% were 60 years of age or older, and 77% had osteoarthritis. Sixty-seven percent of the cases were detected by symptoms and the remainder by abnormal laboratory tests. Seventy-five percent of the symptomatic patients (90 of 120) were jaundiced. Seven of the 90 icteric patients died. The biochemical pattern of injury was hepatocellular or mixed hepatocellular in 66% of cases. Only 8% had a pattern of cholestatic injury. The remainder, with modestly increased values of both transaminases and alkaline phosphatase, were considered "indeterminate," i.e., either mild hepatocellular or anicteric "cholestatic" injury. Sections of liver from 21 cases were available for study. Hepatic injury was apparent by 1 month after starting the drug in 24%, by 3 months in 63%, and by 6 months in 85% of cases. The latent period in 12% was 6 to 12 months, whereas in 3% it was greater than 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

H2O2-induced increases in cellular F-actin occur without increases in actin nucleation activity.

Previous work has shown that H2O2 causes an increase in polymerized actin (F-actin) inside cells. To test the hypothesis that increased polymerization resulted from a mechanism involving increased actin nucleation activity, we employed methods utilizing pyrene-labeled actin to quantify the actin nucleation activity of cell lysates and N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) (NBD)-phallacidin binding assays to quantify the amount of F-actin in P388D1 cells. H2O2 increased polymerized actin (NBD-phallacidin assay) in a dose-dependent manner with an effective dose giving 50% response (ED50) approximately 1 mM. Five millimolar H2O2 caused a 1.6-fold increase in NBD-phallacidin staining. In contrast, actin nucleation activity decreased in a dose-dependent manner with a similar ED50. Five millimolar H2O2 caused a 30-40% decrease in actin nucleation activity. The effect was rapid, occurring within 5 min of H2O2 addition. The results indicate that H2O2 causes cytoskeletal changes that enhance NBD-phallacidin binding without increasing actin nucleation activity. Fractionation studies showed that the nucleation activity in H2O2-treated cells and controls sedimented with the Triton X-100-insoluble cytoskeleton, and the cytosolic fraction appeared to contain an inhibitor of actin polymerization.

Sulindac-associated hepatic injury: analysis of 91 cases reported to the Food and Drug Administration.

BACKGROUND: Recent emphasis on nonsteroidal anti-inflammatory drug (NSAID)-associated hepatic injury blurs differences between NSAIDs. Accordingly, examination of hepatic injury by individual NSAIDs seemed warranted. Sulindac-associated hepatic injury was selected. METHODS: From 338 reports submitted to the Food and Drug Administration, 247 were considered inadequate or unconvincing for sulindac toxicity. The remaining 91 cases of reactions to the drug were analyzed. In 15 there was histological material available. RESULTS: There were four deaths, three attributed to severe hypersensitivity and one to fulminant hepatic failure. Two thirds of the cases had clinical hallmarks of hypersensitivity. The ratio of females to males was 3.5:1; 69% of the patients were over 50 years of age. Jaundice was recorded in 67% of the patients. The pattern was cholestatic in 43%, hepatocellular in 25%, mixed in 12%, and indeterminate in 20% of the patients. Eosinophilia was significantly more frequent in patients with cholestatic injury (40%) than in those with hepatocellular injury (0). CONCLUSION: Sulindac injury involves females more than males. It can lead to cholestatic or hepatocellular injury, most often because of immunological idiosyncrasy. In some patients, metabolic idiosyncrasy may be the mechanism. This study illustrates the utility of analysis of adverse reaction reports in characterizing drug-induced injury.

Producing peak performers--the key to quality patient care.

Quality patient care extends only as far as those who deliver such care. To unlock quality service in each employee, the manager must address three combinations that include recruitment, training, and environment.

A threshold level of coupled G-proteins is required to transduce neutrophil responses.

Chemoattractant-induced activation of human polymorphonuclear leukocytes involves receptor coupling to guanine nucleotide binding proteins (G-proteins). Treatment of polymorphonuclear leukocytes with pertussis toxin, which ADP-ribosylates neutrophil G-proteins and uncouples G-proteins from receptors, causes a conversion of cells from responders to nonresponders rather than a gradual decrease in the ability of all cells to respond (Omann, G. M., and J. M. Harter. 1991. Cytometry 12:252; Omann, G. M., and M. M. Porasik-Lowes. 1991. J. Immunol. 146:1303). Flow-cytometric methods were used to measure N-formylpeptide-induced cytosolic Ca2+ elevation and actin polymerization over a wide range of ADP-ribosylation levels and showed that although the percentage of responding cells varied markedly, the responding cells were stimulated equivalent to controls. The conditions of pertussis toxin (PT) treatment did not interfere with non-G-protein-mediated pathways as assessed by measurement of phagocytosis, a complex process involving the cytoskeleton. We tested the explanation that the all-or-none effect may have been due to heterogeneous insertion of the catalytic subunit of PT into the cells such that responders had no ADP-ribosylation and nonresponders were completely ADP-ribosylated. Measurement of the binding of fluorescent N-formylpeptides to permeabilized cells, which allows the distinction between completely ribosylated and normal cells, showed that all cells treated with a submaximal concentration of PT had intermediate levels of receptor-coupled G-proteins. Thus, partial ADP-ribosylation had occurred in all cells and the all-or-none insertion of the catalytic subunit of PT was ruled out. Thus, there is a threshold of coupled G-proteins required to transduce responses. The ability of PT to inhibit N-formylpeptide-induced actin polymerization and cytosolic calcium elevation was compared and showed that both responses have essentially the same threshold of G-proteins required to transduce the responses. Thus, the pathways regulating actin polymerization and calcium elevation appear to be coupled with equal efficiency to the G-proteins.

Comparative accuracy of fixed partial dentures made as one-piece castings or joined by solder.

Four-unit fixed partial dentures were fabricated as a one-piece casting or as two-piece castings joined by soldering prior to the addition of porcelain. The accuracy of the two techniques was compared and evaluated using an anatomic cast-metal master model. All procedures, including SEM measurements, were performed directly on the master model. The cast one-piece units had smaller vertical marginal openings than did the soldered units. The rigid nature of the abutments evokes the problems occurring with osseointegrated implants.