Evaluation of sulfur and multi-walled carbon nanotube composite synthesized by dissolution and precipitation for Li/S batteries

An elemental sulfur and multi-walled carbon nanotube (S-MWNT) composite was synthesized by dissolving sulfur in ammonium sulfides and then precipitating on MWNT. Morphology observation by scanning electron microscopy (SEM) confirmed that S-MWNT product was successfully prepared by incorporating sulfur into MWNT network. Without additional conducting material, the S-MWNT composite cathodes were prepared for electrochemical tests. The properties measured in discharge-charge cycling test showed that the composite had the initial discharge capacity of 1024 mAh g(-1), which is about 61% sulfur utilization. However, in the subsequent cycling, the capacities faded. To determine the reason of rapid capacity drop, S-MWNT composite cathodes were compared in the cycling tests with varying three kinds of electrolytes and the cathode was subjected to physical force by rolling. The changes in the cycle performances proved that the deterioration of S-MWNT composite cathodes was not related to the electrolytes but to physical bonding that may not maintain the conducting path between sulfur and MWNT.

Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies

OBJECTIVES

This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma.

METHODS

15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups.

RESULTS

Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA.

CONCLUSIONS

When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.

Small hypervascular hepatocellular carcinomas: value of diffusion-weighted imaging compared with "washout" appearance on dynamic MRI

OBJECTIVE

To compare the value of diffusion-weighted MRI (DWI) with the venous "washout" appearance during dynamic MRI for the assessment of small arterial hypervascular lesions in cirrhotic liver.

METHODS

After exclusion of benign hypervascular lesions, including haemangiomas and subcapsular non-tumorous arterioportal shunts, indicated by typical imaging features, a total of 109 small arterial hypervascular lesions (0.5-3.0 cm in the longest diameter) in 65 patients with cirrhosis who underwent gadopentetate dimeglumine-enhanced dynamic MRI and DWI (b=50, 400, 800 s mm(-2)) at 1.5 T during a 16-month period were retrospectively analysed to determine the presence of venous washout during dynamic imaging or sustained hyperintensity upon increasing the b factor size on DWI.

RESULTS

Among the 99 hypervascular hepatocellular carcinomas (HCCs), sustained hyperintensity on DWI (92/99, 93%) was more prevalent than the washout appearance (72/99, 72%) on dynamic MRI (p<0.001). Depending on the lesion size, subcentimetre-sized HCCs had a significantly lower prevalence of venous washout (13/30, 43%) than the sustained hyperintensity on DWI (27/30, 90%) (p=0.001). In all 10 hypervascular benign conditions, there was no venous washout on dynamic MRI and no sustained hyperintensity on DWI. Sensitivity and specificity for diagnosis of hypervascular HCCs were 92.9% and 100% in DWI and 72% and 100% in dynamic MRI, respectively.

CONCLUSION

Compared with the venous washout during dynamic imaging, DWI provides more reliable information in the MRI assessment of small hypervascular HCCs, distinguishing them from atypical hypervascular benign or pseudolesions. DWI could complement the early diagnosis of small hypervascular HCCs that do not display venous washout during dynamic imaging.

New limits on interactions between weakly interacting massive particles and nucleons obtained with CsI(Tl) crystal detectors

New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in the KIMS CsI(Tℓ) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24 524.3  kg·days. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 to 11 keV. The 90% upper limit of the nuclear recoil event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(Tℓ) is 0.0098 counts/kg/keV/day, which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20  GeV/c2.

Ultrafast transient generation of spin-density-wave order in the normal state of BaFe2As2 driven by coherent lattice vibrations

The interplay among charge, spin and lattice degrees of freedom in solids gives rise to intriguing macroscopic quantum phenomena such as colossal magnetoresistance, multiferroicity and high-temperature superconductivity. Strong coupling or competition between various orders in these systems presents the key to manipulate their functional properties by means of external perturbations such as electric and magnetic fields or pressure. Ultrashort and intense optical pulses have emerged as an interesting tool to investigate elementary dynamics and control material properties by melting an existing order. Here, we employ few-cycle multi-terahertz pulses to resonantly probe the evolution of the spin-density-wave (SDW) gap of the pnictide compound BaFe(2)As(2) following excitation with a femtosecond optical pulse. When starting in the low-temperature ground state, optical excitation results in a melting of the SDW order, followed by ultrafast recovery. In contrast, the SDW gap is induced when we excite the normal state above the transition temperature. Very surprisingly, the transient ordering quasi-adiabatically follows a coherent lattice oscillation at a frequency as high as 5.5 THz. Our results attest to a pronounced spin-phonon coupling in pnictides that supports rapid development of a macroscopic order on small vibrational displacement even without breaking the symmetry of the crystal.

Increased striatal dopamine transporter density in moderately severe old restless legs syndrome patients

BACKGROUND AND PURPOSE

Dopamine dysregulation in restless legs syndrome (RLS) may be varied by the severity of RLS, which could contribute to the conflicting results from previous functional neuroimaging studies on the central dopaminergic neurotransmission of RLS. The aim of this study was to observe whether reduced striatal dopaminergic neurotransmission is associated with moderate to moderately severe RLS.

METHODS

Thirteen elderly patients with RLS and 12 normal elderly controls were enrolled in the study. All the subjects were dopaminergic-drug naïve and twelve patients with RLS had the severity of moderate to moderately severe degree based on the International Restless Legs Syndrome Study Group (IRLSSG) Severity Scale. We compared dopamine transporter density (DAT) availability and D2 receptor density in the striatum between patients with RLS and controls using [(123)I]2β-carbomethoxy-3β-(4-iodophenyl)tropane single-photon emission computed tomography (SPECT) and [(123)I]iodobenzamide SPECT.

RESULTS

Dopamine transporter density of patients with RLS was increased in the caudate (P = 0.037), posterior putamen (P = 0.041), and entire striatum (P = 0.046) compared with that of normal controls. DAT density was higher in the anterior putamen of patients with RLS than controls, although statistically not significant (P = 0.079). There was no difference in the D2 receptor density between patients with RLS and normal controls in the whole striatum or any of subregions.

CONCLUSIONS

Dysregulation rather than simple upregulation or downregulation of central dopaminergic neurotransmission may underlie the pathogenesis of RLS, and decreased dopaminergic neurotransmission may cause moderate to moderately severe RLS in the elderly.

Case report. Acinar cell carcinoma with fatty change arising from the pancreas

Acinar cell carcinoma of the pancreas is a rare malignant tumour developing from acinar cells, accounting for approximately 1% of pancreatic exocrine tumours. We experienced a case of an acinar cell carcinoma with fatty change. To the best of our knowledge, this is the first case report of an acinar cell carcinoma with fatty change in the clinical literature.

Effect of splenic artery embolization for splenic artery steal syndrome in liver transplant recipients: estimation at computed tomography based on changes in caliber of related arteries

PURPOSE

To estimate the effect of splenic artery embolization (SAE) on blood flow in orthotopic liver transplantation (OLT) recipients with splenic artery steal syndrome (SASS) based on changes in caliber of related arteries upon serial computed tomography (CT) scans.

METHODS

Between 2004 and 2007, nine OLT recipients with SASS underwent SAE. They had CT scans before and after SAE: short-, mid-, and long-term, ie, approximately 1 week, 1 month, and 1 year, respectively. The diameters of the celiac axis (CA), common hepatic artery (CHA), and splenic artery (SA) were measured with arterial phase of each CT scan and the ratios of SA to CHA diameter (SA/CHA) calculated to analyze their changes during the follow-up period.

RESULTS

The diameters of celiac axis, CHA, and SA and SA/CHA changed most rapidly during the short-term period. The CHA diameter significantly increased short-term post-SAE by CT and slightly decreased thereafter. However, the mid-term and long-term post-SAE CT values were still significantly greater than those on the pre-SAE CT. The SA diameter steadily decreased throughout the follow-up. The SA/CHA decreased until the mid-term. The SA diameter and SA/CHA were significantly smaller upon mid-term and long-term post-SAE CT compared with those at pre-SAE CT.

CONCLUSIONS

The effect of SAE to improve hepatic arterial flow in OLT recipients with SASS might be expected for at least approximately one year. The effect maximally occurred during the short-term after SAE on the basis of changes in the caliber of related arteries upon CT.

Correlation between CT and diffusion-weighted imaging of acute cerebral ischemia in a rat model

BACKGROUND AND PURPOSE

The quantitative temporal relationship between changes in CT attenuation, ADC value, and DWI signal intensity of acute ischemic tissue has not yet been determined in an animal model. This study was performed to determine the temporal relationship between CT attenuation, ADC value, and DWI signal intensity in acute cerebral ischemia.

MATERIALS AND METHODS

CT and DWI were performed at 1, 3, 5, 7, and 9 hours after left MCA occlusion in 11 rats. Mean values for CT attenuation, ADC, and DWI signal intensity were determined for the ischemic hemisphere and contralateral normal hemisphere. Temporal changes in each mean value and the relationship between CT attenuation and ADC value and DWI signal intensity were evaluated.

RESULTS

The decrease of CT attenuation and the increase of DWI signal intensity occurred gradually after MCA occlusion, while ADC value decreased rapidly at 1 hour. Although correlation was significant between time and rCT or rDWI (P<.01, respectively), no correlation between time and rADC was found (P=.33). There was a significant linear correlation between rCT and rDWI (r=0.497, P<.01), but no significant correlation between rCT and rADC (P=.509) was found.

CONCLUSIONS

The temporal change in CT attenuation was different from that in ADC value with no significant linear correlation between CT attenuation and ADC value for acute cerebral ischemia. However, rCT and rDWI showed a modest correlation.

Colour Doppler sonography of hepatic haemangiomas with arterioportal shunts

OBJECTIVES

To determine the frequency of intratumoural flow and peritumoural hepatofugal portal flow using colour Doppler sonography (CDS) on hepatic haemangiomas with arterioportal shunt (APS), and to investigate possible factors that may affect the capability of CDS to depict such findings.

METHODS

The study included 45 patients (35 men, 10 women; mean age, 56 years) with hepatic haemangiomas with APS on CT or MRI. Locating the tumour on greyscale sonography, the depth, size and echogenicity of the tumour were evaluated. CT or MR images were evaluated for fatty liver. CDS was performed to determine the presence of intratumoural flow and peritumoural hepatofugal portal flow. Differences in frequency of intratumoural flow and peritumoural hepatofugal portal flow according to the depth, size, echogenicity and fatty liver were evaluated by Student's t-test and Fisher's exact test.

RESULTS

On CDS, intratumoural flow and peritumoural hepatofugal portal flow were found in 66.7% and 60%, respectively. The tumour depth was the significant variable that affected the capability of CDS to depict such findings. The frequencies of intratumoural flow and peritumoural hepatofugal portal flow were as high as 88% and 80% for shallow (≤30 mm) lesions, and they were 40% and 35% for deep (>30 mm) lesions (p=0.0012; p=0.0051).

CONCLUSION

CDS can commonly depict intratumoural flow and peritumoural hepatofugal portal flow in patients with hepatic haemangiomas with APS. Therefore, CDS should be routinely performed when an incidental mass is encountered during the screening sonography, especially when the lesion is shallow.

Peritransplant monitoring of immune cell function in adult living donor liver transplantation

PURPOSE

We evaluated the clinical utility of peritransplant in vitro assays of immune cell function in adult living donor liver transplant (LDLT) recipients.

METHODS

In particular, we measured immune cell function, using the ImmuKnow assay, in 107 adult LDLT recipients and 200 potential living liver donors (control group) admitted to our center between July 2008 and January 2009.

RESULTS

In the control group, the mean proportion of T-helper/inducer cells was 36.8% ± 8.2%. The degree of immune response was strong in 12%, moderate in 77%, and low in 11%. In the study group, the degree of immune response within the first month was strong in 4.6%, moderate in 38.2%, and low in 57.2%, thus significantly lower than in the control group (P < .001). ImmuKnow results and tacrolimus levels did not show a significant correlation (r(2) = .002, P = .392). Although six patients showed biopsy-proven acute cellular rejection, none showed a strong immune response. Patients with overt infection showed a lower immune response.

CONCLUSIONS

These results indicate that peritransplant assessment of immune response using the ImmuKnow assay does not reliably predict the occurrence of acute rejection. Additional studies are necessary to accurately assess the clinical utility of immune response monitoring.

MRI features of serous oligocystic adenoma of the pancreas: differentiation from mucinous cystic neoplasm of the pancreas

OBJECTIVES

The purpose of this study was to describe the MRI features of the benign pancreatic neoplasm serous oligocystic adenoma (SOA) that differ from those of mucinous cystic neoplasm (MCN), a neoplasm with the potential for malignant degeneration.

METHODS

Seven patients with SOA (seven women; mean age 36.6 years) and eight patients with MCN (eight women: mean age 39.9 years) were included. Several imaging features were reviewed: mass size, location, shape, wall thickness, cyst configuration (Type I, unilocular; Type II, multiple clustered cyst; Type III, cyst with internal septation) and signal intensity of the lesion with heterogeneity.

RESULTS

SOA lesions were smaller (3.4 cm) than those of MCN (9.3 cm) (p=0.023). The commonest lesion shape was lobulated (85.7%) for SOA, but oval (50.0%) or lobulated (37.5%) for MCN (p=0.015). The most common cyst configuration was Type II (85.7%) for SOA and Type III (75.0%) for MCN (p=0.008). Heterogeneity of each locule in T(1) weighted images was visible in all cases of MCN, but in no case for SOA (p=0.004).

CONCLUSION

SOA could be differentiated from MCN by identifying the imaging features of lobulated contour with multiple clustered cyst configurations and homogeneity of each locule in T(1) weighted MR images.

Evidence of a precursor superconducting phase at temperatures as high as 180 K in RBa2Cu3O(7-δ) (R=Y, Gd, Eu) superconducting crystals from infrared spectroscopy

We show that a multilayer analysis of the infrared c-axis response of RBa2Cu3O(7-δ) (R=Y, Gd, Eu) provides important new information about the anomalous normal-state properties of underdoped cuprate high temperature superconductors. In addition to competing correlations which give rise to a pseudogap that depletes the low-energy electronic states below T*≫T(c), it enables us to identify the onset of a precursor superconducting state below T(ons)>T(c). We map out the doping phase diagram of T(ons) which reaches a maximum of 180 K at strong underdoping and present magnetic field dependent data which confirm our conclusions.

Comparison of multi-echo and single-echo gradient-recalled echo sequences for SPIO-enhanced liver MRI at 3 T

AIM

To assess the utility of a T2*-weighted, multi-echo data imaging combination sequenced on superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging (MRI) using a 3 T system.

MATERIALS AND METHODS

Fifty patients underwent SPIO-enhanced MRI at 3 T using T2*-weighted, single-echo, gradient-recalled echo (GRE) sequences [fast imaging with steady precession; repetition time (TR)/echo time (TE), 126 ms/9 ms; flip angle, 30°] and multi-echo GRE (multi-echo data image combination) sequences (TR/TE, 186 ms/9 ms; flip angle, 30°). Three radiologists independently reviewed the images in a random order. The sensitivity and accuracy for the detection of focal hepatic lesions (a total of 76 lesions in 33 patients; 48 solid lesions, 28 non-solid lesions) were compared by analysing the area under the receiver operating characteristic curves. Image artefacts (flow artefacts, susceptibility artefacts, dielectric artefacts, and motion artefacts), lesion conspicuity, and overall image quality were evaluated according to a four-point scale: 1, poor; 2, fair; 3, good; 4, excellent. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the lesions were compared.

RESULTS

Image artefacts were more frequent with single-echo GRE (p<0.05). The mean scale of image quality assessment for flow, susceptibility, dielectric, and motion artefacts were 2.76, 3.13, 3.42, and 2.89 with single-echo, respectively, compared with 3.47, 3.43, 3.47, and 3.39, respectively, with multi-echo GRE. There was no significant difference in lesion conspicuity between single-echo (3.15) and multi-echo (3.30) GRE sequences. The overall image quality was significantly (p<0.05) better with multi-echo (3.37) than with single-echo GRE (2.89). The mean SNR and CNR of the lesions were significantly (p<0.05) higher on multi-echo (79±23 and 128±59, respectively) images than on single-echo (38±11 and 102±44, respectively) images. Lesion detection accuracy and sensitivity were not significantly different between the two sequences. Mean accuracies and sensitivities were 0.864 and 0.785 for single-echo and 0.847 and 0.785 for multi-echo GRE, respectively.

CONCLUSION

At 3 T, the T2*-weighted, multi-echo data image combination sequence performs comparably to the T2*-weighted, single-echo GRE sequence for SPIO-enhanced MRI with good overall image quality and a decrease in undesired artefacts.

MRI findings of uncommon non-hepatocyte origin primary liver tumours with pathological correlation

The objective of this article was to illustrate the MRI findings of uncommon non-hepatocyte origin primary liver tumours, correlate them with the pathological features and discuss differential diagnoses. In conclusion, the MRI findings of uncommon benign and malignant non-hepatocyte-origin primary liver tumours vary. Awareness of characteristic MRI features can aid differential diagnosis and prevent unnecessary surgery.

Microwave imaging reflectometry studies for turbulence diagnostics on KSTAR

The first prototype microwave imaging reflectometry (MIR) system [H. Park et al., Rev. Sci. Instrum. 74, 4239 (2004)] clearly demonstrated the shortcomings of conventional reflectometry when the probe beam encountered a large amplitude and/or high fluctuation wavenumber at the reflection layer in laboratory tests, the distinctive advantages shown in these tests were not fully realized in the plasma operation. To understand the discrepancies, the MIR system performance has been thoroughly investigated at POSTECH. In this paper, a possible cause of the MIR performance degradation on TEXTOR will be presented together with a concept of multifrequency MIR system design that will be developed for KSTAR.

Remodelling of nasal mucosa in mild and severe persistent allergic rhinitis with special reference to the distribution of collagen, proteoglycans, and lymphatic vessels

BACKGROUND

Small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen, and lymphangiogenesis are involved in tissue remodelling of various organs with inflammatory diseases.

OBJECTIVE

We determined the expression level and the distribution pattern of small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa.

METHODS

The distribution pattern of collagen, proteoglycans, and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa was evaluated by the van Gieson staining, immunohistochemistry, RT-PCR, and Western blotting. Quantitative analyses of collagen deposition were calculated as the median of the total percentage area in the tissue specimen. For the evaluation of proteoglycans, the percentage area stained and median optical density were measured for each image. Lymphatic vessels were identified by D2-40 antibody and calculated using the lymphatic vessel density and endothelial length density in tissue specimens. The expression of MMP 2 and 9, TIMP1 and 2 was evaluated with RT-PCR and Western blotting.

RESULTS

In mild and severe persistent allergic nasal mucosa, compared with healthy nasal mucosa, collagen showed more intense staining in the superficial and submucosal layer. In healthy and allergic nasal mucosa, decorin was lightly stained without significant differences in the percentage area and optical density of staining. However, lumican and biglycan showed strong immunoreactivity in mild and severe persistent allergic nasal mucosa, which was verified by Western blotting. The number and endothelial length density of lymphatic vessels were increased in mild and severe persistent allergic nasal mucosa compared with healthy nasal mucosa. The expression of MMP 9 was increased in severe persistent allergic rhinitis.

CONCLUSION AND CLINICAL RELEVANCE

These results suggest that the altered distribution pattern of collagen, proteoglycans, and lymphatic vessels could potentially modulate the remodelling of nasal mucosa in mild and severe persistent allergic nasal mucosa.

Thermoelectric properties of graphene nanoribbons, junctions and superlattices

Using model interaction Hamiltonians for both electrons and phonons and Green's function formalism for ballistic transport, we have studied the thermal conductance and the thermoelectric properties of graphene nanoribbons (GNR), GNR junctions and periodic superlattices. Among our findings we have established the role that interfaces play in determining the thermoelectric response of GNR systems both across single junctions and in periodic superlattices. In general, increasing the number of interfaces in a single GNR system increases the peak ZT values that are thus maximized in a periodic superlattice. Moreover, we proved that the thermoelectric behavior is largely controlled by the width of the narrower component of the junction. Finally, we have demonstrated that chevron-type GNRs recently synthesized should display superior thermoelectric properties.

Characterization of liver metastases: the efficacy of biphasic magnetic resonance imaging with ferucarbotran-enhancement

AIM

To retrospectively evaluate the efficacy of biphasic magnetic resonance imaging (MRI) of the liver with ferucarbotran-enhancement for the characterization of hepatic metastases.

MATERIALS AND METHODS

Thirty-six patients underwent MRI of the liver with separate acquisition of double-contrast enhancement consisting of gadolinium and ferucarbotran. A total of 106 focal hepatic lesions (51 metastases, 31 cysts, 23 haemangiomas, and one eosinophilic abscess) were included. Two sets of MRI were analysed: (1) ferucarbotran set: ferucarbotran-enhanced T1-weighted (T1W) dynamic imaging combined with ferucarbotran-enhanced T2*-weighted (T2*W) delayed imaging and (2) double set: gadolinium-enhanced T1W dynamic imaging combined with ferucarbotran-enhanced T2*W delayed imaging. The diagnostic accuracy of the two sets was evaluated using alternative free-response receiver operating characteristic curve analysis. Sensitivity and specificity were compared using the McNemar test. The enhancement pattern of focal hepatic lesions was analysed on gadolinium and ferucarbotran-enhanced T1W dynamic imaging.

RESULTS

There was no significant difference in the accuracy of characterizing hepatic metastases between the two sets. Sensitivity and specificity were not significantly different between the sets (p>0.05). Peripheral rim enhancement was exhibited in 57% of metastatic lesions on ferucarbotran-enhanced T1W dynamic imaging. The majority (96%) of hepatic haemangiomas demonstrated typical peripheral nodular enhancement with progression on ferucarbotran-enhanced T1W dynamic imaging and were easily differentiated from metastases.

CONCLUSION

Biphasic MRI of the liver with ferucarbotran-enhancement alone provided comparable diagnostic efficacy to double-contrast MRI for the characterization of hepatic metastases.

Femtosecond response of quasiparticles and phonons in superconducting YBa(2)Cu(3)O(7-δ) studied by wideband terahertz spectroscopy

We measure the anisotropic midinfrared response of electrons and phonons in bulk YBa(2)Cu(3)O(7-δ) after femtosecond photoexcitation. A line shape analysis of specific lattice modes reveals their transient occupation and coupling to the superconducting condensate. The apex oxygen vibration is strongly excited within 150 fs, demonstrating that the lattice absorbs a major portion of the pump energy before the quasiparticles are thermalized. Our results attest to substantial electron-phonon scattering and introduce a powerful concept probing electron-lattice interactions in a variety of complex materials.

Coexistence and competition of magnetism and superconductivity on the nanometer scale in underdoped BaFe1.89Co0.11As2

We report muon spin rotation (μSR) and infrared spectroscopy experiments on underdoped BaFe1.89Co0.11As2 which show that bulk magnetism and superconductivity (SC) coexist and compete on the nanometer length scale. Our combined data reveal a bulk magnetic order, likely due to an incommensurate spin density wave (SDW), which develops below T(mag)≈32  K and becomes reduced in magnitude (but not in volume) below Tc=21.7  K. A slowly fluctuating precursor of the SDW seems to develop already below the structural transition at T(s)≈50  K. The bulk nature of SC is established by the μSR data which show a bulk SC vortex lattice and the IR data which reveal that the majority of low-energy states is gapped and participates in the condensate at T≪T(c).

Chitinase induce the release of IL-8 in human airway epithelial cells, via Ca2+-dependent PKC and ERK pathways

Chitinases are produced in significant quantities by hosts defending against infections with chitin-containing organisms. However, little is known about the immune response of exogenous chitinase in human epithelial cells. IL-8 has been suggested to have a role in the pathogenesis of the allergenic inflammation of bronchial asthma. We examined whether Streptomyces griseus (S. griseus) chitinase-induced IL-8 on airway epithelium and identified the involvement of intracellular signalling pathways. H292 cells were treated with S. griseus chitinase with different concentrations and times. The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction. Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to S. griseus chitinase. Cells exposed to S. griseus chitinase showed higher level of IL-8 protein production and mRNA expression. Cells stimulated by S. griseus chitinase resulted in the activation of protein kinase C (PKC), extracellular signal-regulated kinase (ERK) and nuclear factor kappa-B (NF-kB) pathways. Inhibitors of Ca(2+)-dependent PKC (Ro-31-8220, calphostin C and Go6976) significantly abolished chitinase-induced expression of IL-8. However, Ca(2+)-independent PKC inhibitor (rottlerin) did not inhibit IL-8 expression. Through ERK inhibitor (U0126) and NF-kB inhibitor (caffeine acid phenethyl ester) treatment, it was proven that ERK and NF-kB regulated chitinase-induced IL-8 expression. We concluded that S. griseus chitinase-induced IL-8 expression was regulated by the activation of Ca(2+/-)-dependent PKC, ERK and NF-kB in human airway epithelial cells.

Dynamical response and confinement of the electrons at the LaAlO3/SrTiO3 interface

With infrared ellipsometry and transport measurements we investigated the electrons at the interface between LaAlO3 and SrTiO3. We obtained a sheet carrier concentration of N(s) approximately = 5-9x10(13) cm(-2), an effective mass of m*=3.2+/-0.4m(e), and a strongly frequency dependent mobility. The latter are similar as in bulk SrTi(1-x)Nb(x)O3 and therefore suggestive of polaronic correlations. We also determined the vertical concentration profile which has a strongly asymmetric shape with a rapid initial decay over the first 2 nm and a pronounced tail that extends to about 11 nm.

Band engineering and magnetic doping of epitaxial graphene on SiC (0001)

Using calculations from first principles we show how specific interface modifications can lead to a fine-tuning of the doping and band alignment in epitaxial graphene on SiC. Upon different choices of dopants, we demonstrate that one can achieve a variation of the valence band offset between the graphene Dirac point and the valence band edge of SiC up to 1.5 eV. Finally, via appropriate magnetic doping one can induce a half-metallic behavior in the first graphene monolayer. These results clearly establish the potential for graphene utilization in innovative electronic and spintronic devices.

Availability of brain serotonin transporters in patients with restless legs syndrome

BACKGROUND

Selective serotonin reuptake inhibitors have been associated with the risk of restless legs syndrome (RLS), suggesting that dysregulation of serotonergic neurotransmission may provoke or exacerbate RLS.

METHODS

We compared the availability of serotonin transporter (SERT) between 16 drug-naïve patients with RLS and 16 healthy controls. SERT was measured in the pons and medulla via [(123)I]-2beta-carbomethoxy-3beta-(4-iodophenyl) tropane (beta-CIT) SPECT. A ratio of specific to nonspecific brain uptake (V(3)'') was used for all comparisons. RLS was diagnosed according to the criteria proposed by the National Institute of Health, and its severity was measured using the International RLS Study Group (IRLSSG) Severity Scale.

RESULTS

The availability of SERT was similar in the RLS group and the control group with regards to the pons (1.24 +/- 0.31 vs 1.24 +/- 0.25, p > 0.1) and the medulla (0.99 +/- 0.25 vs 1.00 +/- 0.23, p > 0.1). However, IRLSSG Severity Scale scores increased with decrease of SERT availability in both the pons (beta = -0.50, t = -3.19, p = 0.009) and the medulla (beta = -0.42, t = -2.44, p = 0.03).

CONCLUSIONS

Although serotonin transporter (SERT) availability in pons and medulla was similar in the restless legs syndrome (RLS) group and the control group, the severity of RLS symptoms increased as the availability of SERT decreased. These data partially support the hypothesis that an increase of serotonergic neurotransmission in the brainstem may exacerbate RLS, possibly via dual modulations on striatal dopaminergic neurotransmission and on the activities of spinal motor and sensory neurons.