Condensed-matter analogues of the Higgs boson in particle physics allow insights into its behaviour in different symmetries and dimensionalities. Evidence for the Higgs mode has been reported in a ...number of different settings, including ultracold atomic gases, disordered superconductors, and dimerized quantum magnets. However, decay processes of the Higgs mode (which are eminently important in particle physics) have not yet been studied in condensed matter due to the lack of a suitable material system coupled to a direct experimental probe. A quantitative understanding of these processes is particularly important for low-dimensional systems, where the Higgs mode decays rapidly and has remained elusive to most experimental probes. Here, we discover and study the Higgs mode in a two-dimensional antiferromagnet using spin-polarized inelastic neutron scattering. Our spin-wave spectra of Ca2 RuO4 directly reveal a well-defined, dispersive Higgs mode, which quickly decays into transverse Goldstone modes at the antiferromagnetic ordering wavevector. Through a complete mapping of the transverse modes in the reciprocal space, we uniquely specify the minimal model Hamiltonian and describe the decay process. We thus establish a novel condensed-matter platform for research on the dynamics of the Higgs mode.
It has been reported that high-resolution susceptibility-weighted imaging (HR-SWI) is a promising tool for assessing brain tumor characterization noninvasively. The purpose of this study was to ...determine the added value and diagnostic performance of HR-SWI for differentiating solitary enhancing brain lesions (SELs) by assessing intratumoral susceptibility signals (ITSSs).
Sixty-four consecutive patients with SELs, without previous surgery, were retrospectively reviewed. We performed 2 consensus reviews, by using conventional MR images alone and with adjunctive HR-SWI. We applied an ITSS grading system based on the degree of the ITSS. Then, we compared the presence and grade of the ITSSs among specific pathologic types of SELs.
Two observers diagnosed tumor pathology accurately in 43 (67%) of 64 SELs after reviewing the conventional images alone and 50 (78%) of 64 SELs after reviewing the adjunctive HR-SWI (P = .016, McNemar test). ITSSs were seen in 25 (100%) of 25 glioblastoma multiformes (GBMs), in 2 (40%) of 5 anaplastic astrocytomas, and in 11 (73%) of 15 metastatic tumors. Although the ITSSs were unable to distinguish between GBMs and solitary metastatic tumors, differentiation between GBMs and solitary metastatic tumors was achieved (P = .01) by using a high ITSS degree (grade 3). Moreover, the ITSSs could discriminate high-grade gliomas from lymphomas and nontumorous lesions with a specificity of 100% (P < .0001).
The use of ITSSs on HR-SWIs significantly improves the accuracy for the differential diagnosis of SELs compared with the use of conventional MR imaging alone.
This paper investigates how the basicity and alumina content in synthetic slags influence the crystallization behavior that takes place in a heat flux simulator for mold slags. The purpose is to ...elucidate the variation in crystallization behavior for model slags that are expected to be glassy, partly crystalline and fully crystalline in order to correlate the changes in heat flux to the dynamic solid evolution that occurs in the simulator. Three levels of alumina content (3, 15 and 25 wt%) were chosen to investigate the heat transfer behavior through slag film which have different tendency of reaction with molten steel during continuous casting of high aluminum containing Transformation Induced Plasticity (TRIP) steels. A Confocal Scanning Laser Microscopy (CSLM) was used to develop TTT diagrams for the slags. XRD and SEM were also used to analyze the micro-structures of the crystalline phases. The measured heat fluxes through the mold slags tested were found to increase, as the crystallinity of the slag film decreased with decreasing basicity and alumina content. It was found that the crystallization temperature increased, while the incubation time for crystallization decreases with increasing basicity and alumina content. The increase in alumina content induced the precipitation of CaF2 during cooling process and hence a change in the crystalline phase from Ca4Si2O7F2 to Ca2Al2SiO7.
It has been reported that high-resolution susceptibility-weighted imaging (HR-SWI) may demonstrate brain tumor vascularity. We determined whether the degree of intratumoral susceptibility signal ...intensity (ITSS) on HR-SWI correlates with maximum relative cerebral blood volume (rCBVmax) and to compare its diagnostic accuracy for glioma grading with that of dynamic susceptibility contrast (DSC) perfusion MR imaging.
Forty-one patients with diffuse astrocytomas underwent both non-contrast-enhanced HR-SWI and DSC at 3T. We correlated the degree and morphology of ITSS with rCBVmax within the same tumor segment. The degree of ITSS and rCBVmax were compared among 3 groups with different histopathologic grades. Spearman correlation coefficients were determined between the degree of ITSS, rCBVmax, and glioma grade. Receiver operating characteristic (ROC) curve analyses were performed to determine the diagnostic accuracy for glioma grading.
The degree of ITSS showed a significant correlation with the value of rCBVmax in the same tumor segments (r = 0.72, P < .0001). However, the areas of densely prominent ITSSs did not accurately correspond with those of rCBVmax. Spearman correlation coefficients between ITSS degree and glioma grade were 0.88 (95% confidence interval, 0.79-0.94). In the ROC curve analysis of histopathologic correlation by using the degree of ITSS, the optimal sensitivity, specificity, positive predictive value, and negative predictive value for determining a high-grade tumor were 85.2%, 92.9%, 95.8%, and 76.5%, respectively.
The degree of ITSS shows a significant correlation with the value of rCBVmax in the same tumor segments, and its diagnostic performance for glioma grading is comparable with that of DSC.
Electrocardiogram (ECG)-guided central venous catheter (CVC) placement has been reported to be accurate and successful. It has been shown that the CVC tip can be reliably placed at the level of the ...carina using a simple formula based on the puncture site, the ‘brachiocephalic notch’ on the clavicle, and the carina as landmarks. This study was performed to compare the accuracy of CVC tip localization between ECG- and landmark-guided catheterization.
Patients were randomized either to the ECG (n=121) or to the landmark (n=128) group. All catheterizations were performed via the right internal jugular vein (IJV). In the ECG group, CVCs were placed where P-wave returned to a normal configuration on right atrial ECG. In the landmark group, CVCs were placed at a depth derived by adding the distance between insertion point and the notch on the clavicle and the vertical length between the notch and the carina on a routine chest radiograph. On the postoperative portable chest radiograph, incidences of correct CVC tip position, defined as in the superior vena cava, were checked.
CVCs were correctly placed in 96.1% of the landmark group (123/128) and in 95.9% of the ECG group (116/121). The mean CVC tip position relative to the carina was 0.0 95% confidence interval (CI) −0.28 to 0.19 cm in the landmark group and 0.0 (95% CI −0.19 to 0.28) cm in the ECG group.
During central venous catheterization via the right IJV, landmark guidance was comparable with ECG guidance with regard to CVC tip positioning in the superior vena cava.
Auxin regulates a variety of physiological and developmental processes in plants. Although auxin acts as a suppressor of leaf senescence, its exact role in this respect has not been clearly defined, ...aside from circumstantial evidence. It was found here that ARF2 functions in the auxin-mediated control of Arabidopsis leaf longevity, as discovered by screening EMS mutant pools for a delayed leaf senescence phenotype. Two allelic mutations, ore14-1 and 14-2, caused a highly significant delay in all senescence parameters examined, including chlorophyll content, the photochemical efficiency of photosystem II, membrane ion leakage, and the expression of senescence-associated genes. A delay of senescence symptoms was also observed under various senescence-accelerating conditions, where detached leaves were treated with darkness, phytohormones, or oxidative stress. These results indicate that the gene defined by these mutations might be a key regulatory genetic component controlling functional leaf senescence. Map-based cloning of ORE14 revealed that it encodes ARF2, a member of the auxin response factor (ARF) protein family, which modulates early auxin-induced gene expression in plants. The ore14/arf2 mutation also conferred an increased sensitivity to exogenous auxin in hypocotyl growth inhibition, thereby demonstrating that ARF2 is a repressor of auxin signalling. Therefore, the ore14/arf2 lesion appears to cause reduced repression of auxin signalling with increased auxin sensitivity, leading to delayed senescence. Altogether, our data suggest that ARF2 positively regulates leaf senescence in Arabidopsis.
Postreperfusion syndrome (PRS), an acute decrease in blood pressure after reperfusion of the liver graft, occurs frequently during liver transplantation surgery. We supposed that the activation of ...the kallikrein–kinin system leading to extensive systemic vasodilatation was a possible cause. The effect of pretreatment with nafamostat mesilate (NM), a broad spectrum serine protease inhibitor, on the occurrence of PRS was evaluated. Sixty‐two adult liver recipients were randomized to receive an intravenous bolus of either 0.02 mg/kg of NM (NM group, n = 31) or an equal volume of normal saline (control group, n = 31) just before reperfusion of the liver graft. Occurrence of PRS and intraoperative use of vasoactive drugs were compared between the two groups. Postoperative recovery was also compared. PRS was significantly less frequent (48% vs. 81%, p = 0.016) requiring less vasopressors in the NM group compared to the control group. The NM group also showed faster recovery of the mean arterial pressure. Perioperative laboratory values were similar between the two groups. Pretreatment with 0.02 mg/kg of NM immediately before reperfusion decreases the frequency of PRS and vasopressor requirements during the reperfusion period in liver transplantation.
Nafamostat mesilate administration before reperfusion of the liver graft attenuates the occurrence of postreperfusion syndrome and vasopressor requirements during orthotopic liver transplantation.
Maintaining a low central venous pressure (CVP) has been frequently used in liver resections to reduce blood loss. However, decreased preload carries potential risks such as hemodynamic instability. ...We hypothesized that a low CVP with milrinone would provide a better surgical environment and hemodynamic stability during living donor hepatectomy. Thirty‐eight healthy adult liver donors were randomized to receive either milrinone (milrinone group, n = 19) or normal saline (control group, n = 19) infusion during liver resection. The surgical field was assessed using a four‐point scale. Intraoperative vital signs, blood loss, the use of vasopressors and diuretics and postoperative laboratory data were compared between groups. The milrinone group showed a superior surgical field (p < 0.001) and less blood loss (142 ± 129 mL vs. 378 ± 167 mL, p < 0.001). Vital signs were well maintained in both groups but the milrinone group required smaller amounts of vasopressors and less‐frequent diuretics to maintain a low CVP. The milrinone group also showed a more rapid recovery pattern after surgery. Milrinone‐induced low CVP improves the surgical field with less blood loss during living donor hepatectomy and also has favorable effects on intraoperative hemodynamics and postoperative recovery.
Milrinone‐induced low CVP improves the surgical field during living donor hepatectomy.
Aims: The purpose of this study was to investigate the efficacy of continuous ohmic heating for reducing Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in orange juice ...and tomato juice. Methods and Results: Orange juice and tomato juice were treated with electric field strengths in the range of 25–40 V cm−1 for different treatment times. The temperature of the samples increased with increasing treatment time and electric field strength. The rate of temperature change for tomato juice was higher than for orange juice at all voltage gradients applied. Higher electric field strength or longer treatment time resulted in a greater reduction of pathogens. Escherichia coli O157:H7 was reduced by more than 5 log after 60‐, 90‐ and 180‐s treatments in orange juice with 40, 35 and 30 V cm−1 electric field strength, respectively. In tomato juice, treatment with 25 V cm−1 for 30 s was sufficient to achieve a 5‐log reduction in E. coli O157:H7. Similar results were observed in Salm. Typhimurium and L. monocytogenes. The concentration of vitamin C in continuous ohmic heated juice was significantly higher than in conventionally heated juice (P < 0·05). Conclusions: Continuous ohmic heating can be effective in killing foodborne pathogens on orange juice and tomato juice with lower degradation of quality than conventional heating. Significance and Impact of the Study: These results suggest that continuous ohmic heating might be effectively used to pasteurize fruit and vegetable juices in a short operating time and that the effect of inactivation depends on applied electric field strengths, treatment time and electric conductivity.
Enterococcus faecalis is a facultative anaerobic gram-positive commensal bacterium common in the gastrointestinal tract of animals and humans. This study aimed to investigate the protective effects ...of heat-killed E. faecalis EF-2001 (EF-2001) on acute gastric ulcer using a murine model of ethanol (EtOH)-induced acute gastric injury. EF-2001 (20, 40, and 80 mg/kg/day) was administered by oral gavage for 5 days before EtOH treatment (10 mL/kg body weight). EF-2001 effectively attenuated EtOH-induced gastric mucosal injury with reduced gastric mucosal ulcer and histological damage score. Pretreatment of EF-2001 markedly suppressed the phosphorylation of mitogen-activated protein kinases (MAPKs; ERK1/2, JNK, and p38MAPK). In addition, EF-2001 significantly inhibited phosphorylation of nuclear factor kappa B (NF-κB) and subsequently suppressed the upregulation of inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 in gastric tissues. Taken together, these results suggest that EF-2001 exerts a gastroprotective effect against acute gastric injury, and the underlying mechanism might be associated with the suppression of MAPKs and NF-κB signaling and consequent reduction of pro-inflammatory mediators or cytokines.
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