Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8  GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. A significant broadening of the peak in the Δη direction at low p_{T} is found from peripheral to central collisions, which vanishes above 4  GeV/c, while in the Δφ direction the peak is almost independent of centrality. For the 10% most central collisions and 1<p_{T,assoc}<2  GeV/c, 1<p_{T,trig}<3  GeV/c a novel feature is observed: a depletion develops around the center of the peak. The results are compared to pp collisions at the same center of mass energy and ampt model simulations. The comparison to the investigated models suggests that the broadening and the development of the depletion is connected to the strength of radial and longitudinal flow.

Majorana charges, winding numbers and Chern numbers in quantum Ising models

Mapping a many-body state on a loop in parameter space is a simple way to characterize a quantum state. The connections of such a geometrical representation to the concepts of Chern number and Majorana zero mode are investigated based on a generalized quantum spin system with short and long-range interactions. We show that the topological invariants, the Chern numbers of corresponding Bloch band, is equivalent to the winding number in the auxiliary plane, which can be utilized to characterize the phase diagram. We introduce the concept of Majorana charge, the magnitude of which is defined by the distribution of Majorana fermion probability in zero-mode states, and the sign is defined by the type of Majorana fermion. By direct calculations of the Majorana modes we analytically and numerically verify that the Majorana charge is equal to Chern numbers and winding numbers.

Su-Schrieffer-Heeger chain with one pair of [Formula: see text]-symmetric defects

The topologically nontrivial edge states induce [Formula: see text] transition in Su-Schrieffer-Heeger (SSH) chain with one pair of gain and loss at boundaries. In this study, we investigated a pair of [Formula: see text]-symmetric defects located inside the SSH chain, in particular, the defects locations are at the chain centre. The [Formula: see text] symmetry breaking of the bound states leads to the [Formula: see text] transition, the [Formula: see text]-symmetric phases and the localized states were studied. In the broken [Formula: see text]-symmetric phase, all energy levels break simultaneously in topologically trivial phase; however, two edge states in topologically nontrivial phase are free from the influence of the [Formula: see text]-symmetric defects. We discovered [Formula: see text]-symmetric bound states induced by the [Formula: see text]-symmetric local defects at the SSH chain centre. The [Formula: see text]-symmetric bound states significantly increase the [Formula: see text] transition threshold and coalesce to the topologically protected zero mode with vanishing probabilities on every other site of the left-half chain and the right-half chain, respectively.

Measurement of azimuthal correlations of D mesons with charged particles in pp collisions at [Formula: see text] TeV and p-Pb collisions at [Formula: see text] TeV

The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at [Formula: see text] and p-Pb collisions at [Formula: see text] at the Large Hadron Collider. [Formula: see text], [Formula: see text], and [Formula: see text] mesons and their charge conjugates with transverse momentum [Formula: see text] and rapidity in the nucleon-nucleon centre-of-mass system [Formula: see text] (pp collisions) and [Formula: see text] (p-Pb collisions) were correlated to charged particles with [Formula: see text]. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.

Genetic analysis of PITX3 variants in patients with essential tremor

BACKGROUND

A clinical overlap between essential tremor (ET) and Parkinson's disease (PD) has prompted investigation whether these disorders share common genetic factors. The paired-like homeodomain transcription factor 3 gene (PITX3) has been shown to play an important role for the differentiation and survival of midbrain dopaminergic neurons in the substantia nigra pars compacta. The preferential degeneration of those dopaminergic neurons is the pathological hallmark in PD.

AIMS OF THE STUDY

The purpose of this study was to evaluate whether PITX3 variants are related to susceptibility of ET in Chinese Han population.

METHODS

Genetic analysis of two variants rs3758549 and rs4919621 of the PITX3 gene was conducted in 200 Chinese Han patients with ET and 426 controls.

RESULTS

We did not identify any statistically significant difference in either genotypic or allelic frequencies of variants between the ET patients and control cohort (all P > 0.05). Haplotype analysis of two variants in the PITX3 gene showed no potential association between the haplotypes and risk of ET (all P > 0.05).

CONCLUSIONS

Our data suggest that PITX3 variants rs3758549 and rs4919621 are not associated with ET in Chinese Han population.

Quantum phase transition induced by real-space topology

A quantum phase transition (QPT), including both topological and symmetry breaking types, is usually induced by the change of global parameters, such as external fields or global coupling constants. In this work, we demonstrate the existence of QPT induced by the real-space topology of the system. We investigate the groundstate properties of the tight-binding model on a honeycomb lattice with the torus geometry based on exact results. It is shown that the ground state experiences a second-order QPT, exhibiting the scaling behavior, when the torus switches to a tube, which reveals the connection between quantum phase and the real-space topology of the system.

Computed tomography-guided percutaneous microwave ablation treatment for lung metastases from nasopharyngeal carcinoma

BACKGROUND

The objective of this retrospective study was to evaluate the safety and efficacy of percutaneous microwave ablation (MWA) for treating lung metastases from nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

From December 2012 to November 2014, 17 patients (15 males, and two females, averaged 45.7 years old) with lung metastases from NPC accepted computed tomography (CT)-guided percutaneous MWA. The average number of lung metastases was 1.7 (range: 1-4), and the biggest tumor diameter was 4.2 cm (range: 0.8-4.2 cm). Nineteen nodules located in the right lung and 10 nodules located in the left lung. A total of 29 ablation sites were performed to 29 lung metastases in 22 MWA sessions. Postoperative assessments of complete tumor necrosis rate, safety, local tumor progression, and survival period were carried out.

RESULTS

Of the 29 lesions, complete response was achieved for 27 lesions; residual tumor was found in one lesion 3 months postoperatively; and another lesion was found enlarged 3-month postoperatively with obvious enhancement. Four patients had a small amount of postoperative parenchyma bleeding and two patients had a small amount of pneumothorax. Six months after MWA treatment, new metastatic lesions appeared in six patients, five patients had new metastatic lesions inside the lung, and the other patient had metastatic lesions in the thoracic vertebra. The time for the appearance of new pulmonary metastases for the five patients was 4-20 months, averaged 7.2 months.

CONCLUSION

CT-guided MWA is a promising treatment alternative for local tumor control in selected patients with lung metastases from NPC.

Correlated Event-by-Event Fluctuations of Flow Harmonics in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

We report the measurements of correlations between event-by-event fluctuations of amplitudes of anisotropic flow harmonics in nucleus-nucleus collisions, obtained for the first time using a new analysis method based on multiparticle cumulants in mixed harmonics. This novel method is robust against systematic biases originating from nonflow effects and by construction any dependence on symmetry planes is eliminated. We demonstrate that correlations of flow harmonics exhibit a better sensitivity to medium properties than the individual flow harmonics. The new measurements are performed in Pb-Pb collisions at the center-of-mass energy per nucleon pair of sqrt[s_{NN}]=2.76  TeV by the ALICE experiment at the Large Hadron Collider. The centrality dependence of correlation between event-by-event fluctuations of the elliptic v_{2} and quadrangular v_{4} flow harmonics, as well as of anticorrelation between v_{2} and triangular v_{3} flow harmonics are presented. The results cover two different regimes of the initial state configurations: geometry dominated (in midcentral collisions) and fluctuation dominated (in the most central collisions). Comparisons are made to predictions from Monte Carlo Glauber, viscous hydrodynamics, ampt, and hijing models. Together with the existing measurements of the individual flow harmonics the presented results provide further constraints on the initial conditions and the transport properties of the system produced in heavy-ion collisions.

A comparison of adaptive iterative dose reduction 3D and filtered back projection in craniocervical CT angiography

AIM

To compare the effects of exposure parameters on image quality and radiation dose for craniocervical computed tomography angiography (CTA) using adaptive iterative dose reduction in three dimensions (AIDR 3D) and filtered back projection (FBP) algorithms.

MATERIALS AND METHODS

One hundred and eighty patients were divided into three groups; group A (120 kV, 300 mA, FBP), group B (100 kV, automatic mA, AIDR 3D) and group C (80kV, automatic mA, AIDR 3D). Image quality and radiation dose were evaluated for each group.

RESULTS

For both cervical and intracranial vessels, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were higher in the AIDR 3D groups. The difference in mean vascular noise was also statistically significant (p<0.001), with group B having the lowest value at 16.5±3.2 HU and group C having the highest at 19.1±2.9 HU. FBP reconstruction resulted in lower image-quality scores for the common carotid artery. Parenchymal image-quality scores also varied significantly different between groups with group C partially failing to meet the minimum standards for diagnostic use. For the middle cerebral artery, image-quality scores were significantly better in group A, although images from groups B and C also satisfied clinical diagnostic requirements. The image quality of the internal carotid artery was the best in group B. Image-quality scores between groups were not significantly different for the carotid sinus. Radiation doses in the groups using AIDR 3D were >70% lower than in the FBP group.

CONCLUSION

AIDR 3D (100 kV, automatic modulation) provides optimal image quality of vascular and parenchymal tissues at significantly lower radiation doses (mSV) than FBP in craniocervical CTA. For cases in which highly accurate parenchymal assessment is not required, the tube voltage can be lowered to 80 kV to further decrease radiation dose.

Effect of sevoflurane anaesthesia on hepatic blood flow in infants with obstructive hepatobiliary disease

BACKGROUND

Currently most studies on anaesthetic effects on hepatic blood flow of cirrhotic patients have been performed on adults or experimental animals. We performed this study to evaluate the effect of sevoflurane anaesthesia on hepatic blood flow in infants with obstructive jaundice by Doppler ultrasound.

METHODS

Forty-four infants with biliary atresia (1-3 months of age) scheduled for a Kasai procedure were enrolled. Hepatic blood flow was calculated by Doppler ultrasound measurements before induction, and after inhalation of 2% and 3% sevoflurane. Infants were allocated to three groups according to baseline portal blood flow/hepatic artery blood flow: group A (portal blood flow/hepatic artery blood flow < 1), group B (1 ≤ portal blood flow/hepatic artery blood flow < 2) and group C (portal blood flow/hepatic artery blood flow ≥ 2). Changes in portal blood flow, hepatic artery blood flow and hepatic blood flow were compared among groups.

RESULTS

In group A (n = 9), the median (IQR) hepatic blood flow increased after inhalation of 2% sevoflurane compared to that before induction (from 49.7 (32.0-89.0) to 116.1 (40.4-159.1) ml/min; P = 0.035). Whereas in groups B and C in whom the ratio of portal blood flow and hepatic artery blood flow was normal or mildly changed, the increases in hepatic blood flow after sevoflurane anaesthesia were not significant.

CONCLUSIONS

For infants with obstructive jaundice that had reduced portal blood flow and compensatory increase in hepatic artery blood flow, sevoflurane may produce a protective effect on hepatic blood flow.

Magnetic-flux-driven topological quantum phase transition and manipulation of perfect edge states in graphene tube

We study the tight-binding model for a graphene tube with perimeter N threaded by a magnetic field. We show exactly that this model has different nontrivial topological phases as the flux changes. The winding number, as an indicator of topological quantum phase transition (QPT) fixes at N/3 if N/3 equals to its integer part [N/3], otherwise it jumps between [N/3] and [N/3] + 1 periodically as the flux varies a flux quantum. For an open tube with zigzag boundary condition, exact edge states are obtained. There exist two perfect midgap edge states, in which the particle is completely located at the boundary, even for a tube with finite length. The threading flux can be employed to control the quantum states: transferring the perfect edge state from one end to the other, or generating maximal entanglement between them.

MicroRNA-135b inhibits odontoblast-like differentiation of human dental pulp cells by regulating Smad5 and Smad4

AIM

To investigate the function of miRNAs in odontoblast-like differentiation of human dental pulp cells (hDPCs).

METHODOLOGY

Integrated comparative miRNA microarray profiling was used to determine the differential miRNAs expression in odontoblast-like differentiation of hDPCs. The abundance of microRNA-135b (miR-135b) was measured by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH). Bioinformatic analyses combined with luciferase assays were utilized to identify the targets interacting with miR-135b. Overexpression of miR-135b was performed to investigate the role and mechanism in odontoblast-like differentiation of hDPCs. Statistical analysis was performed by one-way analysis of variance (anova) or Student's t-test.

RESULTS

Thirty-six differentially expressed microRNAs in odontoblast-like differentiation of hDPCs were identified. MiR-135b expression was significantly downregulated during hDPCs differentiation (P < 0.05). In addition, miR-135b was able to bind to the 3'-UTR of the Smad5 and Smad4 and repressed these two genes expression (P < 0.05). Furthermore, overexpression of miR-135b suppressed odontoblast-like differentiation of hDPCs and attenuated the expression of Smad5 and Smad4 (P < 0.05).

CONCLUSIONS

These observations indicated a potential role of miR-135b in mediating odontoblast-like differentiation of hDPCs and inhibition of miR-135b might be a promising therapeutic way to facilitate dentine tissue engineering.

Roles of the Laodelphax striatellus Down syndrome cell adhesion molecule in Rice stripe virus infection of its insect vector

The arthropod Down syndrome cell adhesion molecule (Dscam) mediates pathogen-specific recognition via an extensive protein isoform repertoire produced by alternative splicing. To date, most studies have focused on the subsequent pathogen-specific immune response, and few have investigated the entry into cells of viruses or endosymbionts. In the present study, we cloned and characterized the cDNA of Laodelphax striatellus Dscam (LsDscam) and investigated the function of LsDscam in rice stripe virus (RSV) infection and the influence on the endosymbiont Wolbachia. LsDscam displayed a typical Dscam domain architecture, including 10 immunoglobulin (Ig) domains, six fibronectin type III domains, one transmembrane domain and a cytoplasmic tail. Alternative splicing occurred at the N-termini of the Ig2 and Ig3 domains, the complete Ig7 domain, the transmembrane domain and the C-terminus, comprising 10, 51, 35, two and two variable exons, respectively. Potentially LsDscam could encode at least 71 400 unique isoforms and 17 850 types of extracellular regions. LsDscam was expressed in various L. striatellus tissues. Knockdown of LsDscam mRNA via RNA interference decreased the titres of both RSV and Wolbachia, but did not change the numbers of the extracellular symbiotic bacterium Acinetobacter rhizosphaerae. Specific Dscam isoforms may play roles in enhancing the infection of vector-borne viruses or endosymbionts.