Phase-flip transition in coupled electrochemical cells

Time delay is introduced in the coupling between a pair of electrochemical cells. As coupling parameters are varied, the anodic current in the two cells oscillate in synchrony in regimes of periodic as well as chaotic dynamics. When the time delay is varied a phase-flip transition is observed: the relative phase between the synchronized oscillations changes abruptly by pi . This is accompanied by an experimentally measurable discontinuous change in the frequency of the synchronized oscillators.

Suppression of quadrupolar order on Si doping in YbRu(2)(Ge(1 - x)Si(x))(2)

We have investigated the magnetic properties of polycrystalline Y bRu(2)(Ge(1 - x)Si(x))(2) samples using magnetic susceptibility, electrical resistivity, and specific heat measurements. All the results indicate that the Yb ions in Y bRu(2)(Ge(1 - x)Si(x))(2) are in a stable trivalent state. The antiferromagnetic ordering shifts to lower temperature with increasing Si concentration (x). The weak Kondo-like resistivity minimum observed in the resistivity data for x = 0 shifts toward lower temperature with an increase in the Si content and finally disappears. The most dramatic observation is the complete suppression of the quadrupolar ordering in Y bRu(2)Ge(2) (T(Q) = 10 K) even for 2% Si doping.

A whole genome scan to map QTL for milk production traits and somatic cell score in Canadian Holstein bulls

The detection and mapping of genetic markers linked to quantitative trait loci (QTL) can be utilized to enhance genetic improvement of livestock populations. With the completion of the bovine genome sequence assembly, single nucleotide polymorphisms (SNP) assays spanning the whole bovine genome and research work on large scale identification, validation and analysis of genotypic variation in cattle has become possible. The objective of the present study was to perform a whole genome scan to identify and map QTL affecting milk production traits and somatic cell scores using linkage disequilibrium (LD) regression and 1536 SNP markers. Three and 18 SNP were found to be associated with only milk yield (MY) at a genome and chromosome wise significance (p < 0.05) level respectively. Among the 21 significant SNP, 16 were in a region reported to have QTL for MY in other dairy cattle populations and while the rest five were new QTL finding. Four SNP out of 21 are significant for the milk production traits (MY, fat yield, protein yield (PY), and milk contents) in the present study. Six and nine SNP were associated with PY at a genome and chromosome wise significant (p < 0.05) level respectively. Three and 17 SNP were found to be associated with FY at a genome and chromosome wise significant (p < 0.05) level. Five and seven SNP were mapped with somatic cell score at a genome and chromosome wise significant (p < 0.05) level respectively. The results of this study have revealed QTL for MY, PY, protein percentage, FY, fat percentage, somatic cell score and persistency of milk in the Canadian dairy cattle population. The chromosome regions identified in this study should be further investigated to potentially identify the causative mutations underlying the QTL.

Segmental coronary endothelial dysfunction in patients with minimal atherosclerosis is associated with necrotic core plaques

BACKGROUND/OBJECTIVE

Endothelial dysfunction and atherosclerosis are systemic disorders, but are often characterised by segmental involvement and complications. A potential mechanism for local involvement early in the disease process may be related to plaque composition. This study was designed to test the hypothesis that in patients with minimal coronary atherosclerosis, coronary artery segments with abnormal endothelial function have specific plaque characteristics.

METHODS

Intravascular ultrasound (IVUS) images were obtained from 30 patients who underwent coronary endothelial function assessment. Spectral analysis of the IVUS radiofrequency data was used for assessment of plaque composition. IVUS findings of the coronary sections were compared according to the corresponding endothelial response to acetylcholine.

RESULTS

Sections with a decrease epicardial coronary arterial diameter in response to acetylcholine had smaller baseline lumen (7.5 (2.4) mm(2) vs 8.8 (3.3) mm(2), p = 0.006) but larger plaque burden (37.1% (9.4%) vs 31% (7%), p = 0.003) than sections with normal endothelial response. Sections with endothelial dysfunction had larger necrotic core plaques: 0.13 (0.03-0.33) mm(2) vs 0.0 (0.0-0.07), p<0.001 and more dense calcium: 0.03 (IQR 0.0-0.13) mm(2) vs 0.0 (0.0-0.10) mm(2), p<0.01), than those with normal endothelial response. Only necrotic core area was associated with endothelial dysfunction (p<0.001) after adjusting for other measures.

CONCLUSIONS

This study suggests that local coronary endothelial dysfunction in patients with minimal coronary atherosclerosis is associated with plaque characteristics that are typical of vulnerable plaques.

Stress hormone and circulating biomarker profile of apical ballooning syndrome (Takotsubo cardiomyopathy): insights into the clinical significance of B-type natriuretic peptide and troponin levels

OBJECTIVE

To evaluate the stress neurohumoral and cardiac biomarker profile of patients with apical ballooning syndrome (ABS).

METHODS

Plasma-free metanephrines, B-type natriuretic peptide (BNP), high sensitivity C-reactive protein (hsCRP) and troponin T, as well as 24-hour urine catecholamines, metanephrines and free cortisol were measured in 19 ABS and 10 ST-elevation myocardial infarction (STEMI) patients.

RESULTS

An antecedent stressful event was identified in 15 ABS patients. There were no differences in plasma normetanephrine (median 0.64 (IQ range 0.43-0.97) nmol/l vs 0.53 (0.32-0.77) nmol/l, p = 0.44), metanephrine (0.10 (0.10-0.22) nmol/l vs 0.16 (0.10-0.38) nmol/l, p = 0.29), or cortisol levels (16.0 (7.3-44.0) microg/dl vs 13.0 (10.5-23.5) microg/dl, p = 0.95) between ABS and STEMI patients. The 24-hour urine metanephrines, catecholamines and cortisol levels were normal in the majority of ABS patients. Troponin T levels were lower (0.62 (0.18-0.84) ng/ml vs 3.80 (2.04-6.57) ng/ml, p<0.001), but BNP levels were higher in ABS compared with STEMI (944 (650-2022) pg/ml vs 206 (140-669) pg/ml, p = 0.009). HsCRP was similarly elevated in the two groups (11.0 (5.1-110.8) mg/l and 24.3 (8.1-88.6) mg/l, p = 0.78).

CONCLUSIONS

Catecholamine and cortisol levels were not elevated in our cohort of ABS, suggesting that routine measurement of these stress hormones is unlikely to be of diagnostic value in practice. In contrast to STEMI, ABS is characterised by a greater elevation in BNP and less myonecrosis.

Activity of lenalidomide in a phase II trial for T-cell lymphoma: Report on the first 24 cases

8524

Background: Novel therapies are needed to improve outcomes in T-cell lymphomas. We report the interim results of a prospective multicenter trial evaluating lenalidomide in T-cell lymphomas. Methods: Patients with relapsed and refractory T-cell lymphomas other than mycosis fungoides were prescribed oral lenalidomide (25mg daily) on days 1 to 21 of each 28 day cycle, with standardized dose reductions for toxicity. Treatment continued until disease progression, death or unacceptable toxicity. The primary endpoint was overall response rate, and secondary endpoints were complete and partial response rates, progression-free and overall survival (PFS, OS), and safety. The two-stage design allows for up to 40 patients. Results: At the time of this interim analysis, 24 patients were enrolled in this study and 23 were evaluable for response. The median age was 65 years. ECOG PS was 0–1 (n=15), 2 (n=7), 3 (n=2). The histology was peripheral T-cell unspecified (PTCL-u, n=10), angioimmunoblastic (n=7), anaplastic large cell (n=5), enteropathic T-cell (n=1) and hepatosplenic gamma/delta (n=1). Median number of prior therapies was 1 (range, 0–4), and three had prior autologous stem cell transplant. Four patients were previously untreated and not candidates for combination chemotherapy. Median time from completion of prior therapy to the start of lenalidomide was 8 months (range, 1–48 months). The overall response rate was 7/23 (30%); all were partial responses. Two patients had stable disease (SD) for ≥3 cycles. Responses were seen in anaplastic, angioimmunoblastic, and PTCL-u histologies. Median PFS was 96 days (range, 8–696 days). Median OS was 241 days (range, 8–696+ days). Among the 9 patients with SD or better, median PFS was 168 days and median OS has not yet been reached with 241–696 days of follow-up. The most common grade 4 adverse event was thrombocytopenia (33.3%). The most common grade 3 adverse events were neutropenia (20.8%), febrile neutropenia (16.7%), and pain NOS (16.7%). Conclusions: In relapsed and refractory T-cell lymphomas, oral lenalidomide monotherapy has clinical activity and toxicity is consistent with the known profile of lenalidomide. Further study of lenalidomide in these diseases is warranted.

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YbNiB(4): a Kondo lattice with low-dimensional antiferromagnetic fluctuations

We have grown single crystals of YbNiB(4) using a Ni(60)B(40) flux and determined the magnetic properties of this compound by means of magnetic susceptibility, specific heat and electrical resistivity measurement. Yb ions in YbNiB(4) are in a trivalent state and present a transition from a paramagnetic state to an antiferromagnetic (AF) state at T(N1) = 5.4 K and a further transition towards a second AF state at T(N2) = 4.0 K. Kondo type behavior in the resistivity and an enhanced Sommerfeld coefficient γ = 100 mJ mol(-1) K(-2) provide evidence for a significant Kondo interaction. A broad maximum in χ(T) at around 8 K, well above T(N1), suggests low-dimensional antiferromagnetic correlations. Both mechanisms lead to strong fluctuation in an extended temperature range above T(N1), up to the characteristic energy of this system, which was estimated to be T(4f) = 16 K from an analysis of the entropy.

Aeromonas caviae septicemia in immunocompetent gastrointestinal carriers

Aeromonas caviae strains have been isolated from blood and stool cultures of three immunocompetent patients, residents of Northern India, who presented with community acquired septicemia without any recent history of diarrhea. Cell culture infectivity test performed on Hep-2 cells have shown substantial degree of invasiveness in the isolated strains. This case unleashes a possibility of asymptomatic gastrointestinal carriage of such strains of A. caviae in a very large population of India, as several areas of India have very high rates of Aeromonas induced acute diarrhea/gastroenteritis (up to 13%). It needs to be appraised further in India as well as other countries having high rates of Aeromonas induced acute diarrhea/gastroenteritis.

Study of the physical properties of a mesogenic mixture showing induced smectic A(d) phase by refractive index, density and x-ray diffraction measurements

The binary mixture of 4-n-pentyl phenyl 4-n'-hexyloxy benzoate (ME6O.5) and p-cyanophenyl trans-4-pentyl cyclohexane carboxylate (CPPCC) shows the presence of an induced smectic A(d) phase in a certain concentration range 0.03<x(CPPCC)<0.6. The results of the differential scanning calorimetry (DSC), refractive indices, densities and x-ray diffraction measurements are reported here. In general, the change in birefringence is continuous at the smectic A(d) to nematic phase transition for mixtures with x>0.33, whereas there is a discontinuity in these values for mixtures with x<0.33, consistent with the density and transition entropy measurements done on this system. The orientational order parameter, measured from x-ray diffraction studies, are somewhat smaller than those obtained from refractive index measurement in the induced smectic phase for all the mixtures. In the smectic phase, the OOP values initially increases with molar concentration up to x = 0.24 and then decreases showing a broad minima around x = 0.4. The variation of layer thickness in the induced smectic phase with composition has been explained by assuming the formation of homo- and heterodimers. We conclude that the possible packing of molecules in the induced smectic A(d) phase stabilizes the layers but increases the orientational free volume, consistent with the lower orientational order parameter.

A bacterial interference strategy for prevention of UTI in persons practicing intermittent catheterization

Study Design

Non-randomized pilot trial

Objectives

Determine whether Escherichia coli 83972-coated urinary catheters in persons with spinal cord injury (SCI) practicing an intermittent catheterization program (ICP) could (1) achieve bladder colonization with this benign organism, and (2) decrease the rate of symptomatic urinary tract infection (UTI).

Setting

Outpatient SCI clinic in a Veterans Affairs hospital (USA)

Methods

Participants had neurogenic bladders secondary to SCI, were practicing ICP, had experienced at least 1 UTI, and had documented bacteruria within the past year. All subjects received a urinary catheter that had been pre-inoculated with E. coli 83972. The catheter was left in place for 3 days then removed. Subjects were followed with urine cultures and telephone calls weekly for 28 days and then monthly until E. coli 83972 was lost from the urine. Outcome measures were (1) the rate of successful bladder colonization, defined as the detection (≥10² cfu/ml) of E. coli 83972 in urine cultures for > 3 days after catheter removal and (2) the rate of symptomatic UTI while colonized with E. coli 83972.

Results

Thirteen subjects underwent 19 insertions of study catheters. Eight subjects (62%) became successfully colonized for > 3 days after catheter removal. In these 8 subjects, the rate of UTI while colonized was 0.77 per patient-year, in comparison to the rate of 2.27 UTI per patient-year prior to enrollment.

Conclusions

E. coli 83972-coated urinary catheters are a viable means to achieve bladder colonization with this potentially protective strain in persons practicing ICP.