[Analysis of risk factors of short-term prognosis in patients with severe Budd-Chiari syndrome]

Objective: To explore the risk factors of short-term prognosis of severe BCS patients,established and verified the nomogram prediction model for these BCS patients and evaluated its clinical application value. Methods: This study is a retrospective cohort study. The clinical data of 171 patients with severe BCS diagnosed were retrospectively analyzed in the Department of Hepatopancreatobiliary Surgery First Affiliated Hospital of Zhengzhou University from January 2018 to December 2023. There were 105 males and 66 females, aged (52.1±12.8) years (range: 18 to 79 years). The patients were divided into two groups based on whether they died within 28 days: the death group (n=38) and the survival group (n=133). The risk factors for short-term death of patients were analyzed,and independent risk factors were screened by univariate and multivariate analysis. Furthermore,these factors were used to establish the nomogram prediction model. The area under the curve(AUC),the Bootstrap Resampling,the Hosmer-Lemeshow test and the Decision Curve Analysis(DCA) were used to verify the model's differentiation,internal verification,calibration degree and clinical effectiveness,respectively. Results: Univariate and multivariate Logistics regression analysis showed that the history of hepatic encephalopathy,white blood cell,glomerular filtration rate and prothrombin time are independent risk factors (P<0.05). The above factors were used to successfully establish the prediction model with 0.908 of AUC and 0.895 of the internal verification of AUC,indicating that the predictive model was valuable. The 0.663 P-values in the Hosmer-Lemeshow test indicated the high calibration degree of the model. The clinical effectiveness of the model was proved by the 18% clinical benefit population using the DCA curve with the 17% probability threshold. Conclusions: The independent risk factors are the history of hepatic encephalopathy,white blood cell,glomerular filtration rate and prothrombin time. An adequate basis was acquired by establishing a nomogram prediction model of the short-term prognosis of severe BCS,which was helpful for early clinical screening and identification of high-risk patients with severe BCS who could die in the short term and timely providing timely intervention measures for improving the prognosis.

[Effect of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients underwent haploidentical stem cell transplantation]

Objective: To investigate the effects of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients with haploidentical stem cell transplantation (haplo-SCT). Methods: Fifteen consecutive patients who received haplo-SCT and pre-transplant donor specific anti-human leukocyte antigen (HLA) antibody (DSA) positive [mean fluorescence intensity (MFI)≥2 000] in the Institute of Hematological Diseases from November 2021 to March 2023 were retrospectively recruited into the desensitized group. There were 4 males and 11 females, with a median age [M(Q1, Q3)] of 48 (37, 59) years. All patients were desensitized with sirolimus combined with anti-CD20 monoclonal antibody. The non-desensitized group included 29 patients with haplo-SCT who had not received desensitization treatment from August 2012 to June 2016. There were 12 males and 17 females with a median age of 42 (26, 50) years. Up to October 1, 2023, the median follow-up time was 13 (9, 18) months in the study group and 23 (14, 29) months in the control group. The changes of MFI before and after desensitization treatment and the prognosis of patients in the desensitized group were compared, including the incidence of primary implantation failure (pGF), neutrophil implantation time, platelet implantation time, grade Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) and chronic GVHD incidence, non-recurrence related mortality, event-free survival rate, disease-free survival rate and overall survival rate. The survival curve was drawn by Kaplan-Meier method, and the survival rate between groups was compared with Log-rank test. Results: After desensitization treatment, the level of DSA MFI in the desensitized group decreased from 8 879 (7 544, 11 495) to 3 781 (1 638, 4 165) after desensitization treatment (P<0.01). All of the patients achieved hematopoietic recovery, and the median time for neutrophil and platelet engraftment were 14 (11, 15) and 20 (18, 25) days, respectively. The incidence of pGF in the desensitized group was 0, which was lower than that in the non-desensitized group (34.5%, 10/29) (P=0.011). The expected 1-year disease-free survival rate and overall survival rate in the desensitized group were 100% (15/15) and 100% (15/15) respectively, while those in the non-desensitized group were 75.9% (22/29) and 75.9% (22/29) respectively, the difference was not statistically significant (both P>0.05). The one-year event-free survival rate in the desensitized group was expected to be 100% (15/15), which was higher than that in the non-desensitized group (51.3%, 15/29) (P=0.002). Conclusion: Sirolimus combined with anti-CD20 monoclonal antibody desensitization therapy can reduce the DSA level of haplo-SCT recipients, promote hematopoietic engraftment after transplantation, and avoid the occurrence of pGF after transplantation.

[Impact of SARS-CoV-2 infection on graft composition and early transplant outcomes following allogeneic hematopoietic stem cell transplantation]

Objective: To assess the feasibility of using donors with novel coronavirus disease 2019 (COVID-19) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) when there are no other available donors and allo-HSCT cannot be delayed or discontinued. Methods: Seventy-one patients with malignant hematological diseases undergoing allo-HSCT between December 8, 2022, and January 10, 2023, were included. Of these, 16 received grafts from donors with mild COVID-19 (D-COVID(+) group) and 55 received grafts from donors without COVID-19 (D-COVID(-) group). The graft compositions were compared between the two groups. Engraftment, acute graft-versus-host disease (aGVHD), overall survival (OS), and relapse were also evaluated. Results: There were no serious side effects or adverse events in the D-COVID(+) group. The mononuclear cell dose and CD34(+) cell dose were comparable between the two groups, and no additional apheresis was required. There were no significant differences in the lymphocyte, monocyte, and T-cell subset doses between the two groups. The median natural killer cell dose in the D-COVID(+) group was significantly higher than that in the D-COVID(-) group (0.69×10(8)/kg vs. 0.53×10(8)/kg, P=0.031). The median follow-up time was 72 (33-104) days. All patients achieved primary engraftment. The 60-day platelet engraftment rates in the D-COVID(+) and D-COVID(-) groups were 100% and (96.4±0.2) %, respectively (P=0.568). There were no significant differences in neutrophil (P=0.309) and platelet (P=0.544) engraftment times. The cumulative incidence of grade 2-4 aGVHD was (37.5±1.6) % vs. (16.4±0.3) % (P=0.062), and of grade 3-4 aGVHD was 25.0% ±1.3% vs. 9.1% ±0.2% (P=0.095) in the D-COVID(+) and D-COVID(-) groups, respectively. The probabilities of 60-day OS were 100% and 98.1% ±1.8% (P=0.522) in the D-COVID(+) and D-COVID(-) groups, respectively. There was no relapse of primary disease during the study period. Conclusion: When allo-HSCT cannot be delayed or discontinued and no other donor is available, a donor with mild COVID-19 should be considered if tolerable. Larger sample sizes and longer follow-up periods are required to validate these results.

Making Topologically Trivial Non-Hermitian Systems Nontrivial via Gauge Fields

Non-Hermiticity significantly enriches the concepts of symmetry and topology in physics. Particularly, non-Hermiticity gives rise to the ramified symmetries, where the non-Hermitian Hamiltonian H is transformed to H^{†}. For time-reversal (T) and sublattice symmetries, there are six ramified symmetry classes leading to novel topological classifications with various non-Hermitian skin effects. As artificial crystals are the main experimental platforms for non-Hermitian physics, there exists the symmetry barrier for realizing topological physics in the six ramified symmetry classes: while artificial crystals are in spinless classes with T^{2}=1, nontrivial classifications dominantly appear in spinful classes with T^{2}=-1. Here, we present a general mechanism to cross the symmetry barrier. With an internal parity symmetry P, the square of the combination T[over ˜]=PT can be modified by appropriate gauge fluxes. Using the general mechanism, we systematically construct spinless models for all non-Hermitian spinful topological phases in one and two dimensions, which are experimentally realizable. Our Letter suggests that gauge structures may significantly enrich non-Hermitian physics at the fundamental level.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

Topological Electromagnetic Effects and Higher Second Chern Numbers in Four-Dimensional Gapped Phases

Higher-dimensional topological phases play a key role in understanding the lower-dimensional topological phases and the related topological responses through a dimensional reduction procedure. In this work, we present a Dirac-type model of four-dimensional Z_{2} topological insulator (TI) protected by CP symmetry, whose 3D boundary supports an odd number of Dirac cones. A specific perturbation splits each bulk massive Dirac cone into two valleys separated in energy-momentum space with opposite second Chern numbers, in which the 3D boundary modes become a nodal sphere or a Weyl semimetallic phase. By introducing the electromagnetic (EM) and pseudo-EM fields, exotic topological responses of our 4D system are revealed, which are found to be described by the (4+1)D mixed Chern-Simons theories in the low-energy regime. Notably, several topological phase transitions occur from a CP-broken Z_{2} TI to a Z TI when the bulk gap closes by giving rise to exotic double-nodal-line or nodal-hyper-torus gapless phases. Finally, we propose to probe experimentally these topological effects in cold atoms.

Non-Hermitian Spatial Symmetries and Their Stabilized Normal and Exceptional Topological Semimetals

We study non-Hermitian spatial symmetries-a class of symmetries that have no counterparts in Hermitian systems-and study how normal and exceptional semimetals can be stabilized by these symmetries. Different from internal ones, spatial symmetries act nonlocally in momentum space and enforce global constraints on both band degeneracies and topological quantities at different locations. In deriving general constraints on band degeneracies and topological invariants, we demonstrate that non-Hermitian spatial symmetries are on an equal footing with, but are essentially different from Hermitian ones. First, we discover the nonlocal Hermitian conjugate pair of exceptional or normal band degeneracies that are enforced by non-Hermitian spatial symmetries. Remarkably, we find that these pairs lead to the symmetry-enforced violation of the Fermion doubling theorem in the long-time limit. Second, with the topological constraints, we unravel that a certain exceptional manifold is only compatible with and stabilized by non-Hermitian spatial symmetries but is intrinsically incompatible with Hermitian spatial symmetries. We illustrate these findings using two three-dimensional models of a non-Hermitian Weyl semimetal and an exceptional unconventional Weyl semimetal. Experimental cold-atom realizations of both models are also proposed.

Continuous-Variable Assisted Thermal Quantum Simulation

Simulation of a quantum many-body system at finite temperatures is crucially important but quite challenging. Here we present an experimentally feasible quantum algorithm assisted with continuous variable for simulating quantum systems at finite temperatures. Our algorithm has a time complexity scaling polynomially with the inverse temperature and the desired accuracy. We demonstrate the quantum algorithm by simulating a finite temperature phase diagram of the quantum Ising and Kitaev models. It is found that the important crossover phase diagram of the Kitaev ring can be accurately simulated by a quantum computer with only a few qubits and thus the algorithm may be implementable on current quantum processors. We further propose a protocol with superconducting or trapped ion quantum computers.

[Negative effects of donor specific anti-HLA antibody on poor hematopoietic recovery in patients with hematological diseases receiving haploidentical stem cell transplantation and rituximab for desensitization]

Objective: To investigate the incidences and risk factors of poor hematopoietic reconstitution (PHR) in patients with hematological diseases who underwent haploidentical allograft and were treated with rituximab for desensitization. Methods: Eight-three donor specific anti-HLA antibody (DSA, 2000 ≤MFI<10 000) positive patients who underwent haploidentical allograft were prospectively enrolled. Rituximab (375 mg/m²) was used for desensitization day-3 of conditioning regimen. Incidence and factors associated with PHR, including primary poor graft function and prolonged thrombocytopenia, were investigated. Results: There were 22 males and 61 females with a median age of 39(range: 1-65) years. Kaplan-Meier analysis showed that the 100 day cumulative incidences of neutrophil and platelet engraftment were 93.0% and 90.7%, respectively. The incidences of PHR were 14.7%. The 3-year relapse rate, non-relapse mortality (NRM) rate, event-free survival (EFS), leukemia-free survival (DFS) and overall survival (OS) were 6.5%, 15.1%, 70.8%, 79.4% and 79.4%, respectively. Patients with DSA MFI<5 000 (group A, n=46) experienced lower PHR (4.4% vs. 27.5%, P=0.003), and higher 3-year EFS (79.5% vs. 59.8%, P=0.020) compared to those with DSA MFI≥5 000 (group B, n=37). Multivariate analysis showed that DSA MFI≥5 000 was correlated with PHR (HR=6.101, P=0.021). PHR was associated with higher NRM (HR=4.110, P=0.026), lower DFS (HR=3.656, P=0.019) and OS (HR=3.656, P=0.019). Conclusion: Our data suggest that high pre-transplant DSA level is a risk factor for PHR in patients with hematological diseases receiving haploidentical allograft and rituximab for desensitization.

[The effect of donor cytomegalovirus serological status on the outcome of allogeneic stem cell transplantation]

Objective: Donor cytomegalovirus (CMV) serological negative status may have an adverse effect on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT), while there is inadequate data for Chinese people. This study is to explore the impact of donor CMV serological status on the outcome of CMV seropositive patients receiving allo-HSCT. Methods: Our study retrospectively analyzed 16 CMV seropositive patients with hematological malignancies receiving allogeneic grafts from CMV seronegative donors (antibody IgG negative) at Peking University People's Hospital from March 2013 to March 2020, which was defined as D^-/R⁺ group. The other 64 CMV seropositive patients receiving grafts from CMV seropositive donors at the same period of time were selected as matched controls through a propensity score with 1∶4 depending on age, disease state and donor-recipient relationship (D⁺/R⁺ group). Results: Patients in D^-/R⁺ group developed CMV DNAemia later than patients in the D⁺/R⁺ group (+37 days vs. +31 days after allo-HSCT, P=0.011), but the duration of CMV DNAemia in D^-/R⁺ group was longer than that of D⁺/R⁺ group (99 days vs. 34 days, P=0.012). The rate of CMV reactivation 4 times or more in D^-/R⁺ group was 4/16, significantly higher than that of D⁺/R⁺ group (4.7%, 3/64, P=0.01). The incidences of refractory CMV DNAemia (14/16 vs. 56.3%, P=0.021) and CMV disease (4/16 vs. 4.7%, P=0.01) in D^-/R⁺ group were both higher than those in D⁺/R⁺ group. In addition, the application of CMV-CTL as the second-line antiviral treatment in D^-/R⁺ group was more than that in D⁺/R⁺ group. Univariate analysis and multivariate analysis suggested that CMV serological negativity is an independent risk factor for refractory CMV DNAemia and the duration of CMV infection. The cumulative incidence of aGVHDⅡ-Ⅳ, cGVHD, 3-year probability of NRM, overall survival, and the cumulative incidence of relapse were all comparable in two groups. Conclusions: Although there is no significant effect on OS and NRM, the incidence of refractory CMV DNAemia, the frequency of virus reactivation, and the development of CMV disease in D^-/R⁺ group are higher than those in controls. Therefore, CMV seropositive donors are preferred for CMV seropositive patients.

The synergistic effect of grain boundary and grain orientation on micro-mechanical properties of austenitic stainless steel

Micro/nano-scale deformation behavior including hardness, elastic modulus, and pop-ins, was studied in a medical austenitic stainless steel followed by post-mortem EBSD characterization. Relatively higher hardness and modulus was observed near {101} and more pop-ins occurred in this orientation at high loading rate. The activation volume (v) obtained from nanoindentation had weak dependence on grain orientation and was ~10-20 b³, indicating that neither diffusional creep processes nor conventional dislocation segments passing through dislocation forests controls plastic deformation in our study. The plastic zone radius (c) and the distance of the indent from the grain boundary (d) were used to describe the effect of grain boundary on the pop-in effect. The ratio of c/d meets amplitude version of Gaussian peak function distribution for a given orientation, whose peak value remains nearly constant for all the orientations.

[A comparative study of breast cancer mass screening and opportunistic screening in Chinese women]

Objective: To compare the population characteristics, the positive rate of screening, the detection rate of breast cancer, early diagnosis rate and the cost between the mass screening group and opportunistic screening group of breast cancer. Methods: This study is a prospective multicenter cohort study conducted from January 1, 2014 to December 31, 2016. The participants were enrolled for mass screening or opportunistic screening of breast cancer. After completing the questionnaire, all the participants received breast physical examination and breast ultrasound examination every year for 3 rounds by year. The participants' characteristics and screening results of the two groups were compared by χ² test, Fisher exact test or Wilcoxon rank-sum test. Results: A total of 20 080 subjects were enrolled. In the mass screening group, 9 434 (100%), 8 111 (85.98%) and 3 940 (41.76%) cases completed the 3 rounds of screening, and 10 646 (100%), 6 209 (58.32%) and 2 988 (28.07%) cases in the opportunistic screening group, respectively. In the opportunistic screening group, the proportions of less than 3 months lactation (1 275/9 796 vs. 1 061/8 860, χ²=4.597, P=0.032), non-fertility (850/10 646 vs. 574/9 434, χ²=27.400, P<0.01), abortion history (6 384/10 646 vs. 5 062/9 434, χ²=81.232, P<0.01), postmenopausal (2 776/10 646 vs. 2 217/9 434, χ²=17.757, P<0.01), long-term oral contraceptives(>6 months) (171/10 646 vs. 77/9 434, χ²=25.593, P<0.01) and family history of breast cancer in first-degree relatives (464/10 646 vs. 236/9 434, χ²=51.257, P<0.01) were significantly higher than those in mass screening group. The positive rate of screening (514/10 646 vs. 128/9 434, χ²=194.736, P<0.01), the detection rate of breast cancer (158/10 646 vs. 13/9 434, χ²=107.374, P<0.01), and positive rate of biopsy (158/452 vs. 13/87, χ²=13.491, P<0.01) in the opportunistic screening group were significantly higher than those of the mass screening group. The early diagnosis rate of the mass screening group was significantly higher than the opportunistic screening group (10/12 vs. 66/141, χ²=5.902, P=0.015). The average cost for detecting each breast cancer case of the mass screening group was 215 038 CNY, which was 13.6 times of the opportunistic screening group (15 799 CNY/case). In the opportunistic screening group, the positive rate of biopsy in primary hospitals was significantly lower than that in large-volume hospitals (79/267 vs. 79/185, χ²=8.267, P=0.004), but there was no significant difference in the mass screening group (6/37 vs. 7/50, χ²=0.082, P=0.774). Conclusions: Breast cancer screening can improve early detection rate. Compared with the mass screening mode, the opportunistic screening mode has the advantages of higher proportion of high-risk factors, higher positive rate of screening, higher detection rate of breast cancer, higher positive rate of biopsy, and lower cost of screening. However, the early diagnosis rate of breast cancer of opportunistic screening is lower than that of mass screening. The positive rate of opportunistic screening in primary hospitals is lower than that of large-volume hospitals. The two screening modes have their own advantages and should be chosen according to local conditions of different regions in China.

[Retrospective analysis of mechanical thrombectomy for distal branch occlusion of middle cerebral artery]

Objective: To explore the necessity, feasibility, technical points, operative complications and prognosis of mechanical thrombectomy for distal branch occlusion of middle cerebral artery. Methods: Mechanical thrombectomy was performed on 42patients (28 males,14 females; age ranged from 43 to 88 years, mean 65.48years)with distal branch occlusion of middle cerebral artery (M2, M3), between May 2017 to July 2019. Theclinical feature was retrospectively analyzed. The NIHSS score before operation, 24 hours after operation and 1 week after operation, the recanalization of occluded vessels during operation, the complications and the recovery after 3 months (3 months mRS score) were analyzed. Results: Of the 42 patients, 38 patients were successfully recanalized, and the recanalization rate was 90.48%. Postoperative hemorrhage in 6 cases and vasospasm in 17 cases. At 90 days after operation, the mRS score was 0 in 13 cases, 1 in 11 cases, 2 in 6 cases, and 0 cases died. Conclusions: Mechanical thrombotomy is safe and feasible for patients with distal branch occlusion of middle cerebral artery (M2, M3). However, the risks and benefits of patients should be fully considered.

Tamarix chinensis Lour inhibits chronic ethanol-induced liver injury in mice

BACKGROUND

Tamarix chinensis Lour (TCL) is a shrub that usually grows in arid or semiarid desert areas and saline-alkali fields. It is a traditional Chinese herbal medicine with hepatoprotective, antioxidant, antibacterial, and antitumor activities.

AIM

To investigate the possible protective effects of TCL against liver injury induced by chronic ethanol intake.

METHODS

C57BL/6J male mice were fed a Lieber-DeCarli lipid diet containing alcohol and received (by gavage) a water-alcohol extract (80%) of TCL (100 and 200 mg/kg BW) or distilled water for 4 wk. After euthanasia, liver tissues were observed histologically with hematoxylin and eosin staining and Oil red O staining, and the levels of alanine aminotransferase, aspartate transaminase, hepatic lipids, reactive oxygen species, malondialdehyde, and superoxide dismutase were measured. In addition, expression of the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome and downstream proinflammatory cytokines were determined.

RESULTS

Compared with the ethanol group, mice in the TCL-treated group (200 mg/kg) had significantly lower serum levels of alanine aminotransferase (mean, 34.1 IU/L vs 45.3 IU/L, P < 0.01) and aspartate transaminase (mean, 89.6 IU/L vs 115.7 IU/L, P < 0.01), as well as marked reduction of hepatic tissue reactive oxygen species (decreased by 27.5%, P < 0.01) and malondialdehyde (decreased by 76.6%, P < 0.01) levels, with a significant increase of superoxide dismutase (Increased by 73.2%, P < 0.01). Expression of the NLRP3 inflammasome and its downstream cytokines [interleukin (IL)-1β, tumor necrosis factor-α, and IL-6], and recruitment of natural killer T cells to the liver, were reduced in the TCL-treated incubation with a Lieber-DeCaril ethanol lipid diet group.

CONCLUSION

These findings suggest that a TCL extract (200 mg/kg) protects against chronic ethanol-induced liver injury, probably by inhibiting the NLRP3-caspase-1-IL-1β signaling pathway and suppressing oxidative stress.

Protocol for Implementing Quantum Nonparametric Learning with Trapped Ions

Nonparametric learning is able to make reliable predictions by extracting information from similarities between a new set of input data and all samples. Here we point out a quantum paradigm of nonparametric learning that offers an exponential speedup over the sample size. By encoding data into quantum feature space, the similarity between the data is defined as an inner product of quantum states. A quantum training state is introduced to superpose all data of samples, encoding relevant information for learning in its bipartite entanglement spectrum. We demonstrate that a trained state for prediction can be obtained by entanglement spectrum transformation, using the quantum matrix toolbox. We further work out a feasible protocol to implement the quantum nonparametric learning with trapped ions, and demonstrate the power of quantum superposition for machine learning.

Associations of TNF-α -308 G>A and TNF-β 252 A>G with Physical Function and BNP-Rugao Longevity and Ageing Study

OBJECTIVES

To explore the associations of TNF-α -308 G>A (rs1800629) and TNF-β 252 A>G (rs909253) with physical function and plasma B-type natriuretic peptide (BNP).

METHODS

Data of 1747 community-dwelling elders from the ageing arm of the Rugao Longevity and Ageing Study was used. Physical function was measured by handgrip strength, Timed Up and Go (TUG) test and 5-meter walking test (5MWT).

RESULTS

AA genotype of the TNF-α -308 G>A was associated with higher mean time of TUG test and 5MWT (multivariable adjusted β=5.75 and 5.70, respectively, p<0.05), compared with GG genotype. For the TNF-β 252 A>G polymorphism, GG genotype was associated with higher mean time of TUG test and 5MWT (multivariable adjusted β=1.55 and 0.83, respectively, p<0.05) and lower handgrip strength (multivariable adjusted β=-0.69, p<0.05), compared with AA genotype. Further, GG was associated with greater odds of low handgrip strength (OR=1.47, 95% CI=1.06-2.04), low speed of TUG test (OR=1.87, 95% CI=1.20-2.01) and elevated BNP (OR=1.30, 95% CI=1.08-1.84). GG also interacted with elevated BNP to be associated with greater odds of low handgrip strength and 5MWT.

CONCLUSIONS

TNF-β 252 A>G was associated with physical function measurements, plasma BNP level, and odds of elevated BNP in an elderly population. TNF-β 252 A>G also interacted with elevated BNP to be associated with greater odds of physical function measurements.

[Factors influencing poor prognosis of mechanical thrombectomy in time window of acute ischemic stroke]

Objective: Investigate the causes of poor prognosis of mechanical thrombectomy in the time window of acute ischemic stroke (AIS) with anterior circulation. Methods: A retrospective analysis was made on the data of 78 patients with anterior circulation AIS who underwent mechanical thrombectomy in the time window from January 2017 to December 2017 in the Department of Vascular Neurosurgery of Liaocheng Brain Hospital. The modified Rankin scale (mRS) was used to evaluate the prognosis of the patients 3 months after operation. According to the prognosis,the patients were divided into the group with good prognosis (42 cases, mRS<2 points) and the group with poor prognosis (36 cases, mRS<3 points). Univariate and multivariate Logistic regression analysis was used to analyze the related factors of poor prognosis. Results: (1) Univariate analysis showed that the prognosis of patients with good combination and primary stenosis of diabetes mellitus and atherosclerosis was lower than that of patients with poor prognosis (P<0.05). The collateral circulation compensation rate and vascular recanalization rate of patients with good prognosis were higher than those of patients with poor prognosis (P<0.05). Learning significance (P<0.05). (2) Multivariate analysis showed that diabetes mellitus (P=0.035), collateral circulation compensation (P=0.011) and primary atherosclerotic stenosis (P=0.042) were independent risk factors for poor prognosis. Conclusion: Perfect preoperative evaluation and strict screening of patients, good collateral circulation compensation,individualized treatment for patients with primary atherosclerotic stenosis,and strict control of postoperative hyperglycemia can improve the clinical prognosis of endovascular therapy.

Simulation and Manipulation of Tunable Weyl-Semimetal Bands Using Superconducting Quantum Circuits

We simulated highly tunable Weyl-semimetal bands using superconducting quantum circuits. Driving the superconducting quantum circuits with microwave fields, we mapped the momentum space of a lattice to the parameter space, realizing the Hamiltonian of a Weyl semimetal. By measuring the energy spectrum, we directly imaged the Weyl points, whose topological winding numbers were further determined from the Berry curvature measurement. In addition, we manipulated the band structure with an additional pump microwave field, producing a momentum-dependent Weyl-point energy together with an artificial magnetic field, which are indispensable for generating chiral magnetic topological currents in some special Weyl semimetals and may have significant impact on topological physics.

Photonics meets topology

The topological phases in materials have been studied in recent decades for their unique boundary states and transport properties. Photonic systems with band structures embrace the topological phases closely, where they not only provide platforms to testify the topological band theory, but also shed light on designing novel optical devices. In this review, we present exciting developments, supported by brief descriptions of prominent milestones of topological phases in photonic systems in recent years. These studies may sustain further developments of optical devices and offer novel methods for light manipulations.

RNA-seq analysis provides insight into reprogramming of culm development in Zizania latifolia induced by Ustilago esculenta

We report a transcriptome assembly and expression profiles from RNA-Seq data and identify genes responsible for culm gall formation in Zizania latifolia induced by Ustilago esculenta. The smut fungus Ustilago esculenta can induce culm gall in Zizania latifolia, which is used as a vegetable in Asian countries. However, the underlying molecular mechanism of culm gall formation is still unclear. To characterize the processes underlying this host-fungus association, we performed transcriptomic and expression profiling analyses of culms from Z. latifolia infected by the fungus U. esculenta. Transcriptomic analysis detected U. esculenta induced differential expression of 19,033 and 17,669 genes in Jiaobai (JB) and Huijiao (HJ) type of gall, respectively. Additionally, to detect the potential gall inducing genes, expression profiles of infected culms collected at -7, 1 and 10 DAS of culm gall development were  analyzed. Compared to control, we detected 8089 genes (4389 up-regulated, 3700 down-regulated) and 5251 genes (3121 up-regulated, 2130 down-regulated) were differentially expressed in JB and HJ, respectively. And we identified 376 host and 187 fungal candidate genes that showed stage-specific expression pattern, which are  possibly responsible for gall formation at the initial and later phases, respectively. Our results indicated that cytokinins play more prominent roles in regulating gall formation than do auxins. Together, our work provides general implications for the understanding of gene regulatory networks for culm gall development in Z. latifolia, and potential targets for genetic manipulation to improve the future yield   of  this crop.

[Efficacy and security of matched unrelated donor hematopoietic stem cell transplant with transfusion of multipotent mesenchymal cells in pediatric severe aplastic anemia]

目的

探讨HLA相合无关供者造血干细胞移植（MUD-HSCT）联合脐带间充质干细胞（MSC）输注治疗儿童重型再生障碍性贫血（SAA）的疗效及安全性。

方法

回顾性分析19例行MUDHSCT联合MSC治疗的儿童SAA患者临床资料，观察移植后造血重建及移植相关并发症。

结果

19例患儿移植后均获得迅速造血重建，粒细胞中位植入时间为12(9~21) d，血小板中位植入时间为14(8~24) d, 1例患儿于移植后4个月出现继发植入失败。9例患儿发生Ⅰ度急性移植物抗宿主病（aGVHD），1例发生Ⅲ度aGVHD并于移植后6个月发生广泛型慢性移植物抗宿主病。CMV阳性15例，出血性膀胱炎2例。10例患儿移植后出现不同程度、不同部位的感染。中位随访时间为27(8~70）个月，19例患儿截至随访终点均无病存活，其中1例患儿于移植后4个月发生淋巴细胞增殖性疾病，接受利妥昔单抗联合化疗治疗后发生继发性植入失败，后接受以父亲为供者的单倍体造血干细胞移植成功植入。

结论

MUD-HSCT联合MSC输注治疗儿童SAA是安全有效的。

[Expression of FoxM1 and BCRP in invasive breast carcinoma of no special type and its prognosis significance]

Objective: To investigate the relationship between expression of FoxM1 and BCRP in invasive breast carcinoma of no special type (IBC-NST) tissues and the clinical pathological characteristics and prognosis of the patients. Methods: Seventy-eight cases of IBC-NST with excision were included. The expression of FoxM1 and BCRP was assessed by immunohistochemistry and its relationship with the clinical pathological characteristics and prognosis was evaluated. Results: FoxM1 was expressed in 71.8%(56/78) of IBC-NST, and the expression was related to tumor diameter, TNM staging, ER, PR and HER2. BCRP was expressed in 53.8% (42/78) of IBC-NST, and the expression was related to age, tumor diameter, lymph node metastasis, ER and HER2. Kaplan-Meier survival analysis showed the survival time was related to tumor diameter, TNM staging, lymph node metastasis and the expression of FoxM1, BCRP, ER, PR and HER2. Cox multivariate analysis showed that TNM staging, FoxM1, BCRP, HER2 were determinants of patient survival time. Conclusions: The expression of FoxM1 is associated with tumor diameter, TNM staging, ER, PR and HER2 while BCRP is associated with age, tumor diameter, lymph node metastasis, ER and HER2. Both FoxM1 and BCRP have prognostic significance in IBC-NST patients.

[Combined multiple artery-first approach to pancreatoduodenectomy]

Objective: To investigate the clinical application of combined multiple artery-first approach to pancreatoduodenectomy. Methods: The clinical data of 53 patients who were diagnosed with peripancreatic head tumor at Department of Biliary-Pancreatic Surgery of Second Affiliated Hospital of Harbin Medical University between June 2013 and June 2015 was retrospectively analyzed.Pancreatic enhanced CT scan, magnetic resonance cholangiopancreatography, ultrasonography and tumor marker detection were applied for all the patients preoperatively.The 53 patients were operated by combined multiple artery-first approach(superior+ posterior approach, superior+ inferior approach, posterior+ inferior approach, superior+ posterior+ inferior approach) according to individualized therapeutic concept.And 42 patients underwent pancreatoduodenectomy, 9 patients underwent palliative operation and 2 patients just received exploratory operation. Results: Forty-two peripancreatic head tumor patients underwent pancreatoduodenectomy by applying combined multiple artery-first approach.The median operation time and intraoperative blood loss were (5.4±3.1)hours and (366±297)ml and the harvested lymph node and duration of hospital stay were 19±5 and (14.0±5.6)days.Nine patients underwent "total mesopancreas excision" and the rate of postoperative pancreatic fistula and R0 resection were 38.1% and 88.1%. Anomalous origin hepatic right artery was detected in one patients during the operation and no death occurred within 30 days postoperatively. Conclusion: According to the tumor location and patient's condition, individualistically applying combined multiple artery-first approach can reduce intraoperative blood loss, terminate unnecessary surgery, detect anomalous origin artery, make the tumor resection more radical and pancreatoduodenectomy more safety.

Unified Theory of PT and CP Invariant Topological Metals and Nodal Superconductors

As PT and CP symmetries are fundamental in physics, we establish a unified topological theory of PT and CP invariant metals and nodal superconductors, based on the mathematically rigorous KO theory. Representative models are constructed for all nontrivial topological cases in dimensions d=1, 2, and 3, with their exotic physical meanings being elucidated in detail. Intriguingly, it is found that the topological charges of Fermi surfaces in the bulk determine an exotic direction-dependent distribution of topological subgap modes on the boundaries. Furthermore, by constructing an exact bulk-boundary correspondence, we show that the topological Fermi points of the PT and CP invariant classes can appear as gapless modes on the boundary of topological insulators with a certain type of anisotropic crystalline symmetry.

Novel Z(2) Topological Metals and Semimetals

We report two theoretical discoveries for Z(2) topological metals and semimetals. It is shown first that any dimensional Z(2) Fermi surface is topologically equivalent to a Fermi point. Then the famous conventional no-go theorem, which was merely proven before for Z Fermi points in a periodic system without any discrete symmetry, is generalized so that the total topological charge is zero for all cases. Most remarkably, we find and prove an unconventional strong no-go theorem: all Z(2) Fermi points have the same topological charge ν(Z(2))=1 or 0 for periodic systems. Moreover, we also establish all six topological types of Z(2) models for realistic physical dimensions.

[Comparisons of clinical effects among three kinds of treatments of 1/3 displaced midshaft clavicular fractures in adults]

OBJECTIVES

To compare the clinical effects among three kinds of treatments (external fixation, plate fixation, and non-operation) of 1/3 displaced midshaft clavicular fractures in adults.

METHODS

Retrospective analysis was conducted on 306 patients with clavicular fractures in Trauma Orthopedic Department in Jishuitan Hospital from March 2010 to May 2013, and 89 of these patients met the inclusive criteria.Among them, there were 29 cases of external fixation (Group A), 30 cases of plate fixation (Group B), and 30 cases of non-operation with the clavicle sling in Outpatient and Emergency Department (Group C). The average follow-up period was 32 months.The results were evaluated from four perspectives, respectively, follow-up period, Constant Shoulder Score (CSS), Disability of the Arm Shoulder and Hand Score (DASH), and imaging.There was no significant difference in demography, severity of injuries, mechanism of injury, and fracture type among the patients in the three groups.

RESULTS

Among 29 cases of external fixation, 25 cases were successfully followed up, 4 were lost.60 cases of plate fixationand non-operation were all successfully followed up.Based on the pairwise comparison of CSS and DASH among the three groups, there was no significant difference between external fixation [(94.0±6.4), (15.2±3.4)Score] and plate fixation[(92.9±8.4), (15.7±3.5)Score] (both P>0.05). Mean values of CSS and DASH of non-operation group [(86.0±3.6), (18.0±3.6)Score] were lower than those of the former two groups (P<0.001). The healing time of 3 kinds of treatments were as follows: external fixation 10.4±2.32 weeks; plate fixation 12.1±2.5 weeks; and non-operation 15.7±2.2 weeks.In terms of their complications, for the external fixation group, there was 1 case of nonunion (4%); and 3 cases of angulation deformity in the 12(th) week, whose external fixations were maintained till their unions in the 16(th) week.Shortening and displacement did not appear in any cases.In the plate fixation group, there was 1 case of nonunion (3%) and no malunion in this group.The biggest complications of plate fixation were implants stimulus and to remove the plate in the second operation, accounting for 60%.In the non-operation group, there were 3 cases of nonunion (10%), and 12 cases of malunion (40%) including 10 cases without symptoms and 2 cases with symptoms.The satisfaction rates for the appearance of shoulder after these 3 kinds of treatments among the patients were 96%, 93% and 77%, respectively.

CONCLUSIONS

(1) In treating 1/3 displaced midshaft clavicular fractures in adults, external fixation and plate fixation are overall better than non-operation.And there is no significant difference in curative effects between the two. (2) Both external fixation and plate fixation have its advantages and disadvantages.The choice of treatment must be based on the clinical type of the fracture and the communication with patients.

Seroprevalence of Toxoplasma gondii infection in freerange chickens in Jilin Province, northeastern China

The prevalence of Toxoplasma gondii infection in free-range chickens in Jilin province, northeastern China was investigated. A total of 1095 serum samples were collected from nine administrative regions from July to October, 2012, and antibodies to T. gondii were examined by an in-house enzyme-linked immunosorbent assay (ELISA) using Toxoplasma lysate antigen (TLA). The detection results were confirmed by Western blot. The overall seroprevalence of T. gondii in free-range chickens was 17.6% (95% confidence interval [CI], 15.4-19.4%), ranging from 13.3% (95% CI, 6.3-20.4%) in Siping to 23.6% (95% CI, 15.7-31.6%) in Liaoyuan. There was no significant difference in T. gondii infection among different regions in Jilin province (P> 0.05). The widespread presence of T. gondii infection in freerange chickens of Jilin province implies the wide contamination with T. gondii oocysts in the living environment of people, and free-range chickens might be an important source of infection for humans.

Robust interface between flying and topological qubits

Hybrid architectures, consisting of conventional and topological qubits, have recently attracted much attention due to their capability in consolidating robustness of topological qubits and universality of conventional qubits. However, these two kinds of qubits are normally constructed in significantly different energy scales, and thus the energy mismatch is a major obstacle for their coupling, which can support the exchange of quantum information between them. Here we propose a microwave photonic quantum bus for a strong direct coupling between the topological and conventional qubits, where the energy mismatch is compensated by an external driving field. In the framework of tight-binding simulation and perturbation approach, we show that the energy splitting of Majorana fermions in a finite length nanowire, which we use to define topological qubits, is still robust against local perturbations due to the topology of the system. Therefore, the present scheme realizes a rather robust interface between the flying and topological qubits. Finally, we demonstrate that this quantum bus can also be used to generate multipartitie entangled states with the topological qubits.

Disordered Weyl Semimetals and Their Topological Family

We develop a topological theory for disordered Weyl semimetals in the framework of the gauge invariance of the replica formalism and boundary-bulk correspondence of Chern insulators. An anisotropic topological θ term is analytically derived for the effective nonlinear σ model. It is this nontrivial topological term that ensures that the bulk transverse transport of Weyl semimetals is robust against disorders. Moreover, we establish a general diagram that reveals the intrinsic relations among topological terms in the nonlinear σ models and gauge response theories, respectively, for (2n+2)-dimensional topological insulators, (2n+1)-dimensional chiral fermions, (2n+1)-dimensional chiral semimetals, and (2n)-dimensional topological insulators with n being a positive integer.

Seroprevalence of Toxoplasma gondii infection in pigs in Jilin Province, Northeastern China

In the present study, a total of 1,235 porcine serum samples were collected from 9 counties in Jilin Province (40°52'~46°18'N,121°38'~131°19'E), northeastern China from August to October 2013, and the seroprevalence of Toxoplasma gondii infection was tested by indirect haemagglutination assay (IHA). The results showed that antibodies to T. gondii were found in 19.1% (95% confidence interval [CI], 16.9% to 21.3%), with higher seroprevalence in the breeding boars (28.6%, 95% CI, 20.0% to 37.2%), and breeding sows (32.0%, 95% CI, 25.2% to 38.9%). No significant difference was found among the slaughter pigs, fattening pigs and the piglets. These results indicated that infection with T. gondii in pigs is widespread in Jilin province, and is of public health concern.

MTHFR C677T polymorphism and osteoporotic fracture in postmenopausal women: a meta-analysis

Numerous studies have evaluated the association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women. However, the results have been inconsistent. We performed a meta-analysis of the association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women. Only seven case-control studies were retrieved, with a total of 4258 patients and 3454 healthy controls. Meta-analysis results showed no significant association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women for all genetic models (for TT vs CC: OR=0.99, 95%CI=0.72-1.39; for TT vs TC: OR=1.02, 95%CI=0.87-1.20; for CC+TC vs TT: OR=0.96, 95%CI=0.71-1.28; for TT+TC vs CC: OR=0.93, 95%CI=0.84-1.03). In the subgroup analysis by ethnicity, the results also showed no significant association between MTHFR C677T polymorphism and susceptibility to osteoporotic fracture in postmenopausal women in both Caucasian and Asian populations. In conclusion, this meta-analysis suggests that MTHFR C677T polymorphism may not be associated with susceptibility to osteoporotic fracture in postmenopausal women.

General monogamy relation for the entanglement of formation in multiqubit systems

We prove exactly that the squared entanglement of formation, which quantifies the bipartite entanglement, obeys a general monogamy inequality in an arbitrary multiqubit mixed state. Based on this kind of exotic monogamy relation, we are able to construct two sets of useful entanglement indicators: the first one can detect all genuine multiqubit entangled states even in the case of the two-qubit concurrence and n-tangles being zero, while the second one can be calculated via quantum discord and applied to multipartite entanglement dynamics. Moreover, we give a computable and nontrivial lower bound for multiqubit entanglement of formation.

High fidelity quantum state transfer in electromechanical systems with intermediate coupling

Hybrid quantum systems usually consist of two or more subsystems, which may take the advantages of the different systems. Recently, the hybrid system consisting of circuit electromechanical subsystems have attracted great attention due to its advanced fabrication and scalable integrated photonic circuit techniques. Here, we propose a scheme for high fidelity quantum state transfer between a superconducting qubit and a nitrogen-vacancy center in diamond, which are coupled to a superconducting transmission-line resonator with coupling strength g1 and a nanomechanical resonator with coupling strength g2, respectively. Meanwhile, the two resonators are parametrically coupled with coupling strength J. The system dynamics, including the decoherence effects, is numerical investigated. It is found that both the small (J<<{g1,g2}) and large (J>>{g1,g2}) coupling regimes of this hybrid system can not support high fidelity quantum state transfer before significant technique advances. However, in the intermediate coupling regime (J ~ g1 ~ g2), in contrast to a conventional wisdom, high fidelity quantum information transfer can be implemented, providing a promising route towards high fidelity quantum state transfer in similar coupled resonators systems.

Regulation of photosynthetic performance and antioxidant capacity by ⁶⁰Co γ-irradiation in Zizania latifolia plants

The aim of the present work was to investigate the photosynthetic performance and antioxidant enzyme activities in response to γ-irradiation of an aquatic plant Zizania latifolia. The Z. latifolia seedlings at 6-leaf stage were exposed to 25, 50 and 100 Gy of γ rays from a (60)Co source. The growth parameters, chlorophyll contents, photosynthetic gas exchange, chlorophyll fluorescence, malondialdehyde (MDA) content, antioxidant enzyme activities and antioxidant contents were examined at 1-5 weeks post-irradiation (WPI). The results showed that plant height, leaf number and tiller (branch close to ground) number were significantly suppressed by 50 and 100 Gy irradiation at 5, 3-5 and 4-5 WPI, respectively, but they were not significantly different from control by 25 Gy irradiation. Chlorophyll a, chlorophyll b, and total chlorophyll contents were also found to be significantly decreased by irradiation. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) generally declined in a dose-dependent manner. As for the chlorophyll fluorescence parameters, maximum quantum efficiency of PSII photochemistry (Fv/Fm), actual photochemical efficiency of PSII (Φ(PSII)) and photochemical quenching (qP) were observed to be significantly decreased compared to the control at 3 WPI, while non-photochemical quenching (NPQ) significantly increased by 100 Gy. γ-irradiation induced substantial increase in MDA content, ascorbate peroxidase (APX) activity, reduced ascorbate (AsA) content and reduced glutathione (GSH) content, suggesting a protective mechanism of Z. latifolia plant against oxidative stress when exposed to γ-irradiation.

Topological classification and stability of Fermi surfaces

In the framework of the Cartan classification of Hamiltonians, a kind of topological classification of Fermi surfaces is established in terms of topological charges. The topological charge of a Fermi surface depends on its codimension and the class to which its Hamiltonian belongs. It is revealed that six types of topological charges exist, and they form two groups with respect to the chiral symmetry, with each group consisting of one original charge and two descendants. It is these nontrivial topological charges which lead to the robust topological protection of the corresponding Fermi surfaces against perturbations that preserve discrete symmetries.

Liquid chromatography-mass spectrometry method for the quantification of posaconazole in human plasma: application to pharmacokinetics following single-dose administration in the fasted state and with a high-fat meal

A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed to determine concentrations of posaconazole in human plasma precipitated by acetonitrile including internal standard. Rapid chromatographic separation was achieved in the mobile phase composition of acetonitrile, water and formic acid (v/v/v, 55:45:0.1) with a flow rate of 0.25 ml/min. Posaconazole-d4 was used as internal standard. Detection was undertaken with cation electrospray tandem mass spectrometry on a Sciex/API3000. The method was accurate, specific and sensitive for the analysis of posaconazole in human plasma in the concentration range of 2-1000 ng/ml. The inter- and intra-batch accuracy was within +/- 10% and the lower limit of quantification was 2 ng/ml. The method facilitated a clinical pharmacokinetic study after oral administration of a single-dose of posaconazole suspension in the fasted state and with a high-fat meal in a two-period crossover design. Cmax (maximum concentration) and AUC (area under serum drug concentration) were significantly increased, and Tmax (time to maximum plasma concentration) was delayed under fed condition, which suggested that simultaneous administration of posaconazole with food may help to achieve higher plasma concentrations and result in better antifungal efficacy.

Isolation and characterization of microsatellite DNA loci from the peanut worm, Sipunculus nudus

Sipunculus nudus, the peanut worm, is the best known species in its genus. This unsegmented subtidal marine worm is consumed in some parts of Asia and is also used as fish bait. We found 20 microsatellite DNA markers for S. nudus. The number of alleles per polymorphic locus ranged from two to seven in a sample of 39 individuals. Observed and expected heterozygosities per polymorphic locus varied from 0.103 to 1.000 and from 0.307 to 0.771, respectively. Five loci showed significant departure from Hardy-Weinberg equilibrium after sequential Bonferroni's correction. No significant linkage disequilibrium between pairs of loci was found. These microsatellite markers will provide useful tools for investigating genetic population structure, population history and conservation management of S. nudus.

Exact solutions for a type of electron pairing model with spin-orbit interactions and Zeeman coupling

A type of electron pairing model with spin-orbit interactions or Zeeman coupling is solved exactly in the framework of the Richardson ansatz. Based on the exact solutions for the case with spin-orbit interactions, it is shown rigorously that the pairing symmetry is of the p + ip wave and the ground state possesses time-reversal symmetry, regardless of the strength of the pairing interaction. Intriguingly, how Majorana fermions can emerge in the system is also elaborated. Exact results are illustrated for two systems, respectively, with spin-orbit interactions and Zeeman coupling.

Probing non-abelian statistics of Majorana fermions in ultracold atomic superfluid

We propose an experiment to directly probe the non-abelian statistics of Majorana fermions by braiding them in an s-wave superfluid of ultracold atoms. We show that different orders of braiding operations give orthogonal output states that can be distinguished through Raman spectroscopy. Realization of Majorana states in an s-wave superfluid requires strong spin-orbital coupling and a controllable Zeeman field in the perpendicular direction. We present a simple laser configuration to generate the artificial spin-orbital coupling and the required Zeeman field in the dark-state subspace.

Imbalanced superfluid state in an annular disk

The imbalanced superfluid state of spin- 1/2 fermions with s-wave pairing is numerically studied by solving the Bogoliubov-de Gennes equation at zero temperature in an annular disk geometry with narrow radial width. Two distinct types of systems are considered. The first case may be relevant to heavy fermion superconductors, where magnetic field causes spin imbalance via Zeeman interaction and the system is studied in a grand canonical ensemble. As the magnetic field increases, the system is transformed from the uniform superfluid state to the Fulde-Ferrell-Larkin-Ovchinnikov state, and finally to the spin polarized normal state. The second case may be relevant to cold fermionic systems, where the number of fermions of each species is fixed as in a canonical ensemble. In this case, the ground state depends on the pairing strength. For weak pairing, the order parameter exhibits a periodic domain wall lattice pattern with a localized spin distribution at low spin imbalance, and a sinusoidally modulated pattern with extended spin distribution at high spin imbalance. For strong pairing, the phase separation between the superfluid state and polarized normal state is found to be preferable, while the increase of spin imbalance simply changes the ratio between them.

Delocalization of relativistic dirac particles in disordered one-dimensional systems and its implementation with cold atoms

We study theoretically the localization of relativistic particles in disordered one-dimensional chains. It is found that the relativistic particles tend to delocalization in comparison with the nonrelativistic particles with the same disorder strength. More intriguingly, we reveal that the massless Dirac particles are entirely delocalized for any energy due to the inherent chiral symmetry, leading to a well-known result that particles are always localized in one-dimensional systems for arbitrary weak disorders to break down. Furthermore, we propose a feasible scheme to detect the delocalization feature of the Dirac particles with cold atoms in a light-induced gauge field.

Electronic structure and unusual exchange splitting in the spin-density-wave state of the BaFe2As2 parent compound of iron-based superconductors

The magnetic properties in the parent compounds are often intimately related to the microscopic mechanism of superconductivity. Here we report the first direct measurements on the electronic structure of a parent compound of the newly discovered iron-based superconductor, BaFe2As2, which provides a foundation for further studies. We show that the energy of the spin density wave in BaFe2As2 is mainly lowered through exotic exchange splitting of the band structure.

Implementation of adiabatic geometric gates with superconducting phase qubits

We present an adiabatic geometric quantum computation strategy based on the non-degenerate energy eigenstates in (but not limited to) superconducting phase qubit systems. The fidelity of the designed quantum gate was evaluated in the presence of simulated thermal fluctuations in a superconducting phase qubits circuit and was found to be quite robust against random errors. In addition, it was elucidated that the Berry phase in the designed adiabatic evolution may be detected directly via the quantum state tomography developed for superconducting qubits. We also analyze the effects of control parameter fluctuations on the experimental detection of the Berry phase.

Realizing and detecting the quantum Hall effect without landau levels by using ultracold atoms

We design an ingenious scheme to realize Haldane's quantum Hall model without Landau levels by using ultracold atoms trapped in an optical lattice. Three standing-wave laser beams are used to construct a wanted honeycomb lattice, where different on site energies in two sublattices required in the model can be implemented through tuning the phase of one laser beam. The staggered magnetic field is generated from the light-induced Berry phase. Moreover, we establish a relation between the Hall conductivity and the atomic density, enabling us to detect the Chern number with the typical density-profile-measurement technique.

An additive and operational entanglement measure: conditional entanglement of mutual information

Based on the monogamy of entanglement, we develop the technique of quantum conditioning to build an additive entanglement measure: the conditional entanglement of mutual information. Its operational meaning is elaborated to be the minimal net "flow of qubits" in the process of partial state merging. The result and conclusion can also be generalized to multipartite entanglement cases.

Tuning kinetic magnetism of strongly correlated electrons via a staggered flux

An interplay between kinetic process and magnetic ordering is manifested when strong correlation and electronic frustration are present: tuning a staggered flux phi from 0 to pi makes the ground state (GS) of an infinite-U Hubbard model change abruptly from a Nagaoka-type ferromagnet to a Haerter-Shastry-type antiferromagnet at a phi_(c), with both states being metallic and of kinetic origin. Intraplaquette spin correlation, as well as nonanalyticity in the GS energy, signals such a novel quantum criticality. This tunable kinetic magnetism is generic and may be experimentally realized.

Geometric phase in eigenspace evolution of invariant and adiabatic action operators

The theory of geometric phase is generalized to a cyclic evolution of the eigenspace of an invariant operator with N-fold degeneracy. The corresponding geometric phase is interpreted as a holonomy inherited from the universal Stiefel U(N) bundle over a Grassmann manifold. Most significantly, for an arbitrary initial state, this holonomy captures the inherent geometric feature of the state evolution that may not be cyclic. Moreover, a rigorous theory of geometric phase in the evolution of the eigenspace of an adiabatic action operator is also formulated, with the corresponding holonomy being elaborated by a pullback U(N) bundle.

Geometric quantum computation and multiqubit entanglement with superconducting qubits inside a cavity

We analyze a new scheme for quantum information processing, with superconducting charge qubits coupled through a cavity mode, in which quantum manipulations are insensitive to the state of the cavity. We illustrate how to physically implement universal quantum computation as well as multiqubit entanglement based on unconventional geometric phase shifts in this scalable solid-state system. Some quantum error-correcting codes can also be easily constructed using the same technique. In view of the gate dependence on just global geometric features and the insensitivity to the state of cavity modes, the proposed quantum operations may result in high-fidelity quantum information processing.

Clustering through postinhibitory rebound in synaptically coupled neurons

Postinhibitory rebound is a nonlinear phenomenon present in a variety of nerve cells. Following a period of hyperpolarization this effect allows a neuron to fire a spike or packet of spikes before returning to rest. It is an important mechanism underlying central pattern generation for heartbeat, swimming and other motor patterns in many neuronal systems. In this paper we consider how networks of neurons, which do not intrinsically oscillate, may make use of inhibitory synaptic connections to generate large scale coherent rhythms in the form of cluster states. We distinguish between two cases (i) where the rebound mechanism is due to anode break excitation and (ii) where rebound is due to a slow T-type calcium current. In the former case we use a geometric analysis of a McKean-type model to obtain expressions for the number of clusters in terms of the speed and strength of synaptic coupling. Results are found to be in good qualitative agreement with numerical simulations of the more detailed Hodgkin-Huxley model. In the second case we consider a particular firing rate model of a neuron with a slow calcium current that admits to an exact analysis. Once again existence regions for cluster states are explicitly calculated. Both mechanisms are shown to prefer globally synchronous states for slow synapses as long as the strength of coupling is sufficiently large. With a decrease in the duration of synaptic inhibition both systems are found to break into clusters. A major difference between the two mechanisms for cluster generation is that anode break excitation can support clusters with several groups, while slow T-type calcium currents predominantly give rise to clusters of just two (antisynchronous) populations.