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MotivationIdentifying the drug-protein interactions (DPIs) is crucial in drug discovery, and a number of machine learning methods have been developed to predict DPIs. Existing methods usually use unrealistic datasets with hidden bias, which will limit the accuracy of virtual screening methods. Meanwhile, most DPIs prediction methods pay more attention to molecular representation but lack effective research on protein representation and high-level associations between different instances. To this end, we presented here a novel structure-aware multi-modal DPIs prediction model, X-DPI, performing on a curated industry-scale benchmark dataset.ResultsWe built a high-quality benchmark dataset named GalaxyDB for DPIs prediction. This industry-scale dataset along with an unbiased training procedure resulted in a more robust benchmark study. For informative protein representation, we constructed a structure-aware graph neural network method from the protein sequence by combining predicted contact maps and graph neural networks. Through further integration of structure-based representation and high-level pre-trained embeddings for molecules and proteins, our model captured more effectively the feature representation of the interactions between them. As a result, X-DPI outperformed state-of-the-art DPIs prediction methods and obtained 5.30% Mean Square Error (MSE) improved in the DAVIS dataset and 8.89% area under the curve (AUC) improved in GalaxyDB dataset. Moreover, our model is an interpretable model with the transformer-based interaction mechanism, which can accurately reveal the binding sites between molecule and protein.

Jiaqi Zhang, Wencheng Zhang, Baozhong Zhang, Dong Qian, Xiaoxia Li, Hualei Zhang, Qi Wang, Lujun Zhao, Qingsong Pang, Ping Wang Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin 300060, People’s Republic of ChinaCorrespondence: Ping WangTianjin Medical University Cancer Institute and Hospital, Huanhu West Street, Tianjin 300060, People’s Republic of ChinaTel +86 222 334 1405Fax +86 222 334 1405Email wangping@tjmuch.comPurpose: To evaluate and analyze the efficacy and prognostic factors of intensity-modulated radiotherapy in 250 patients with cervical and upper esophageal carcinoma.Patients and methods: From September 2009 to September 2016, we retrospectively analyzed 250 patients with cervical and upper esophageal carcinoma treated with intensity-modulated radiotherapy (IMRT). In our study, all patients received IMRT, 54 patients with cervical esophageal carcinoma and 196 patients with upper esophageal carcinoma. Treatment response, survival status and failure modes of treatment were observed, and prognostic factors were analyzed.Results: The median survival time was 22.60 months and 3-year survival rate was 42%. The median progress-free survival time was 14.52 months and 3-year progress-free survival rate was 29.3%. The median survival time and the median progress-free survival time for cervical esophageal carcinoma were 20.40 and 15.15 months, respectively. The median survival time and the median progress-free survival time for upper esophageal carcinoma were 25.80 and 14.52 months, respectively (P>0.05). The significant clinical factors associated with survival were patient age, radiotherapy dose and T stages (P

Gang Zhao,1 Liwei Zhang,2 Dejian Qian,1 Yifeng Sun,1 Wei Liu11Orthopaedics Department, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, People’s Republic of China; 2Burn and Plastic Surgery Department, Juye County North City Hospital, He Ze, Shandong 274900, People’s Republic of ChinaBackground: Osteosarcoma (OS) is one of the most common malignant tumors of bone, and microRNAs (miRNAs/miRs) serve critical roles in the progression of human OS. The aim of the present study was to investigate the role of miR-495-3p in OS.Methods: The expression of miR-495-3p in OS tissues and adjacent tissues from 30 patients was measured by reversetranscription-quantitative PCR(RT-qPCR). Human OS cell lines (U-2 OS, MG-63 and Saos-2 cells) and normal osteoplastic cells (hFoB 1.19 cells) were employed to perform the further analysis. The cell proliferation ability of MG-63 cells was measured by Cell Counting Kit-8 assay and colony formation assay. In addition, cell invasion and migration were evaluated by Transwell and scratch wound healing assays, respectively. Flow cytometry was applied to assess cell apoptosis and the cell cycle. Moreover, RT-qPCR and Western blotting were performed to measure mRNA and protein expression. A luciferase reporter assay was used to verify the target gene of miR-495-3p. Furthermore, a xenograft OS model was made to evaluate the effect of miR-495-3p in vivo.Results: The results revealed that miR-495-3p was downregulated in the OS tissues and GBM cell lines. Additionally, miR-495-3p overexpression suppressed the proliferation, migration and invasion of MG-63 cells. Simultaneously, cell apoptosis was promoted, accompanied by cell cycle arrest, after transfecting with miR-495-3p mimics. In addition, the expression levels of cell apoptosis-related proteins were increased, whereas proteins of the cell cycle were decreased. Importantly, C1q/TNF-related protein 3 (CTRP3) was confirmed as a direct target of miR-495-3p. A xenograft tumor model was employed to verify the effects of miR-495-3p on OS.Conclusion: On the basis of these results, we conclude that miR-495-3p overexpression inhibited cell proliferation, migration and invasion by downregulating CTRP3. Therefore, miR-495-3p may act as a tumor suppressor and an underlying target for OS treatment.Keywords: osteosarcoma, miR-495-3p, invasion, C1q/TNF-related protein 3

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Daquan Wang,* Wencheng Zhang,* Dong Qian, Yong Guan, Xi Chen, Hualei Zhang, Jun Wang, Qingsong Pang Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China *These authors contributed equally to this work Background: Nab-paclitaxel is produced by the combination of paclitaxel particles with human serum albumin. Encouraging efficacy has been observed with nab-paclitaxel-based chemotherapy in a variety of solid tumors. The aim of the study reported here was to evaluate the efficacy and safety of weekly nab-paclitaxel plus cisplatin with concurrent intensity-modulated radiotherapy in patients with locally advanced esophageal cancer. Methods: Seventeen patients with esophageal cancer were enrolled between July 2014 and December 2015.The treatment included radical radiotherapy (95% planning target volume 60Gy/30f) and concurrent chemotherapy comprising nab-paclitaxel 60mg/m2/week plus cisplatin 25mg/m2/week, administered on days 1, 8, 15, and 22 of each 28-day cycle. The end point of this study included objective response rate (ORR), local-recurrence free survival (LRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS). Results: All the patients enrolled in the trial had squamous cell carcinoma. The median follow-up duration was 20.47 months. The ORR was 88.2%. LRFS, DMFS, PFS and OS at 3 years were 61%, 40%, 17% and 35%, respectively. The trial regimen was well tolerated, with grade 3–4 myelosupression, grade 3 radioactive esophagitis, and grade 3 radiation pneumonitis rates of 17.6%, 17.6%, and 11.8%, respectively. Conclusion: Weekly nab-paclitaxel plus cisplatin with concurrent intensity-modulated radiotherapy is an effective and well-tolerated treatment option for inoperable, locally advanced squamous cancer of esophageal. Keywords: nab-paclitaxel, esophageal cancer, squamous cell carcinoma

Hang-ju was one of five officinal varieties of Flos chrysanthemum for its edible and potable usage. Besides Flos Chrysanthemum (FL), there were also Bud Chrysanthemum (BC) and Fetal Chrysanthemum (FC) at the early and late stage of buds, respectively, in the consumption market of Hang-ju with higher prices. Whether the quality and efficiency of BC and FC was superior to FL or merely consumption misunderstandings? Three commercial products of Hongxinju, a representive cultivar of Hang-ju were studied with a GC-MS based metabolomics approach, complemented with morphology, contents of moisture and protein and the anti-oxidant activity, to reveal the metabolic alterations of violate components in Hongxinju in different flowering stage and at different processing periods. It revealed that most of the violate components were increased from fresh FC to FL, and the low-boiling fractions, inflammatory methyl arachidonate and air-polluting component of ethylbenzene were declined while the representative components with pungent flavor and cool nature of a-curcumene and (Z,Z,Z)-9,12,15-octadecatrienoic acid, vision improving carotenol of rhodopin and high-boiling fractions were elevated after processed in final FL compared with that in BC and/or FC. Though the content of protein and anti-oxidative capacity of final BC and FC were nearly equal to those of FL, in comprehensive consideration of the representative components related with the efficiency in heat cooling and vision improving, as well as the representative components related with inflammation and air-pollution, final FL was recommended other than BC and FC in the practice of medicine with the yield and quality integrated into account.

BACKGROUND Methotrexate (MTX) is an efficacious treatment for psoriasis; however, its widespread application is limited by its unpredictable efficacy. OBJECTIVES To investigate the association of clinical factors and variants of psoriasis susceptibility genes with clinical responses to MTX in a prospective cohort. METHODS A total of 221 patients with psoriasis were recruited. Patients who achieved Psoriasis Area and Severity Index (PASI) improvement ≥ 75% at week 12 were defined as responders, whereas those with PASI improvement < 50% were defined as nonresponders. In 90 screening patients, genetic variants for 18 single-nucleotide polymorphisms in 14 susceptibility genes, and HLA-Cw6 status were initially compared for responders and nonresponders. Statistically significant associations in genetic variants were verified in all 221 patients. RESULTS Overall, 49% and 45% of patients achieved PASI 75 improvement during screening and verification stages, respectively. Concomitant arthritis with psoriasis and high body mass index (BMI) negatively affect the efficacy of MTX. TT genotype of rs10036748 in TNIP1 was significantly associated with PASI 75 response at week 12 (54% and 37%, P < 0·05). A significantly higher PASI 90 response was observed in patients with TT genotype of rs10036748 (27% vs. 12%, P < 0·01) and TC/TT genotype of rs4112788 in LCE3D (25% vs. 13%, P < 0·05) at week 12 compared with those who had other genotypes. After adjustment for all confounding factors, only BMI (P < 0·05), arthritis (P < 0·05) and genotype of rs10036748 (P < 0·05) were significantly associated with clinical responses to MTX. CONCLUSIONS Patients with psoriasis with TT genotype of rs10036748 in TNIP1, with lower BMI, without arthritis will achieve a better response to MTX.

Dong Qian,1 Jingjing Cheng,1 Xiaofeng Ding,1 Xiuli Chen,1 Xi Chen,1 Yong Guan,1 Bin Zhang,2 Jiefu Wang,3 Puchun Er,1 Minghan Qiu,1 Xianliang Zeng,1 Yihang Guo,1 Huanhuan Wang,1 Lujun Zhao,1 Dan Xie,4 Zhiyong Yuan,1 Ping Wang,1 Qingsong Pang1 1Department of Radiotherapy, 2Department of Lung Cancer, 3Department of Colorectal Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, 4State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou, People’s Republic of China Abstract: PinX1 plays positive and negative roles in the maintenance of telomerase and telomeres, as well as in tumorigenesis. The aim of the present study was to investigate the expression and clinical significance of PinX1 in colorectal carcinoma (CRC) and to determine the effect of PinX1 on CRC cell proliferation and apoptosis. A total of 86 CRC patients treated with radical resection and 5-fluorouracil-based adjuvant chemotherapy were enrolled in this study. The expression dynamics of PinX1 was detected by immunohistochemistry in the CRC patients and 25 normal colonic mucosa controls. PinX1 expression was significantly reduced in tumor tissues as compared to normal tissues, and the rate of PinX1 protein low/negative expression in CRC and normal tissues was 60% (52/86) and 24% (6/25), respectively (P=0.037). In addition, PinX1 downregulation was significantly associated with short overall survival (P=0.016) and disease-free survival (P=0.042) in CRC patients. Cox proportional hazards model further revealed that PinX1 expression was an independent factor in predicting overall survival and disease-free survival for CRC patients. Furthermore, we demonstrated that ectopic overexpression of PinX1 in CRC cells inhibited their proliferation, promoted apoptosis, repressed telomerase activity, and induced telomere shortening. These findings suggest that PinX1 may be a prognostic biomarker for CRC patients’ survival and that it inhibits cell proliferation and promotes apoptosis by repressing telomerase activity and inducing telomere shortening. Targeting PinX1 may therefore provide a novel therapeutic strategy for CRC patients. Keywords: colorectal carcinoma, PinX1, cell proliferation, apoptosis, telomerase, telomere, prognostic biomarker

Xian-Liang Zeng,* Huan-Huan Wang,* Mao-Bin Meng, Zhi-Qiang Wu, Yong-Chun Song, Hong-Qing Zhuang, Dong Qian, Feng-Tong Li, Lu-Jun Zhao, Zhi-Yong Yuan, Ping Wang Department of Radiation Oncology, Tianjin’s Clinical Research Center for Cancer and Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, People’s Republic of China *These authors contributed equally to this work Background and aim: The aim of this study is to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) using CyberKnife in the treatment of patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. Patients and methods: Between October 1, 2006 and May 1, 2015, patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery were enrolled and treated with SBRT at our hospital. The primary end point was local control rate after SBRT. Secondary end points were overall survival, time to symptom alleviation, and toxicity, assessed using the Common Terminology Criteria for Adverse Events version 4.0. Results: Twenty-four patients with 24 lesions (17 abdominal lymph nodes and seven stumps) were treated with SBRT, of which five patients presented with abdominal lymph nodes and synchronous metastases in the liver and lung. The 6-, 12-, and 24-month actuarial local control rates were 95.2%, 83.8%, and 62.1%, respectively. For the entire cohort, the median overall survival from diagnosis and SBRT was 28.9 and 12.2months, respectively. Symptom alleviation was observed in eleven of 14 patients (78.6%) within a median of 8days (range, 1–14days) after SBRT. Nine patients (37.5%) experienced Common Terminology Criteria for Adverse Events version 4.0 grade 1–2 acute toxicities; one patient experienced grade 3 acute toxicity due to thrombocytopenia. Conclusion: SBRT is a safe and effective treatment for patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. Further studies are needed before SBRT can be recommended routinely. Keywords: stereotactic body radiation therapy, pancreatic adenocarcinoma, recurrent disease, overall survival

Yao Sun,1 Monika Joks,2 Li-Ming Xu,1 Xiu-Li Chen,1 Dong Qian,1 Jin-Qiang You,1 Zhi-Yong Yuan1 1Department of Radiation Oncology, CyberKnife Center, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, People’s Republic of China; 2Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Science, Poznan, Poland Background: The breast is a rare site of extranodal involvement of diffuse large B-cell lymphoma (DLBCL). We aimed to assess the clinical characteristics, prognostic factors, and treatment outcomes of breast DLBCL.Patients and methods: We retrospectively analyzed 113 patients (from our institution and the literature) between 1973 and 2014. The primary end point was overall survival (OS). Kaplan–Meier OS curves were compared with the log-rank test. Cox regression analysis was applied to determine the prognostic factors for OS, progression-free survival (PFS), local control (LC), and cause-specific survival (CSS).Results: A total of 113 patients were included in the study: 42 cases from our hospital and 71cases from 12 publications. The median age at diagnosis was 58 years. With a median follow-up time of 39.2 months, the estimated 5-year OS, PFS, LC, and CSS were 71.4%, 58.8%, 75.6%, and 74.9%, respectively. In multivariate analysis, more than four cycles of chemotherapy, having localized cancer, lumpectomy with or without axillary lymph node (ALN) dissection,and low to low-to-intermediate International Prognostic Index were favorable factors for OS. For PFS, significant prognostic factors were rituximab use, B symptoms, and tumor size. As for the local group, lumpectomy with or without ALN dissection and more than four cycles of chemotherapy were favorable factors for OS. Tumor size >4 cm and nonuse of rituximab were adverse factors for PFS. Twenty-one patients (18.6%) developed local relapse and 33 (29.2%) developed systemic relapse. Eight patients had central nervous system relapse (7.3%).Conclusion: Our results reveal that local and extended staging criteria can reflect the different prognosis and treatment outcomes of breast DLBCL. Rituximab use, lumpectomy, and more than four cycles of chemotherapy are recommended as a treatment regimen. However, further study is warranted to validate our data. Keywords: diffuse large B-cell lymphoma, breast, rituximab, surgery, chemotherapy

Electron systems that possess light-like dispersion relations or the conical Dirac spectrum, such as graphene and bismuth, have recently been shown to harbor unusual collective states in high magnetic fields. Such states are possible because their light-like electrons come in spin pairs that are chiral,which means that their direction of propagation is tied to a quantity called pseudospin that describes their location in the crystal lattice. An emerging direction in quantum materials research is the manipulation of atomic spin-orbit coupling to simulate the effect of a spin dependent magnetic field,in attempt to realize novel spin phases of matter. This effect has been proposed to realize systems consisting of unpaired Dirac cones that are helical, meaning their direction of propagation is tied to the electron spin itself, which are forbidden to exist in graphene or bismuth. The experimental existence of topological order can not be determined without spin-resolved measurements. Here we report a spin-and angle-resolved photoemission study of the hexagonal surface of the Bi2Te3 and Bi{2-x}MnxTe3 series, which is found to exhibit a single helical Dirac cone that is fully spin-polarized. Our observations of a gap in the bulk spin-degenerate band and a spin-resolved surface Dirac node close to the chemical potential show that the low energy dynamics of Bi2Te3 is dominated by the unpaired spin-helical Dirac modes. Our spin-texture measurements prove the existence of a rare topological phase in this materials class for the first time, and suggest its suitability for novel 2D Dirac spin device applications beyond the chiral variety or traditional graphene., 13 pages, 4 figures

We present a systematic angle-resolved photoemission spectroscopic study of the high-Tc superconductor class (Sr/Ba){1-x}(K/Na)xFe2As2. By utilizing a photon-energy-modulation contrast and scattering geometry we report the Fermi surface and the momentum dependence of the superconducting gap, Delta(k). A prominent quasiparticle dispersion kink reflecting strong scattering processes is observed in a binding-energy range of 25-55 meV in the superconducting state, and the coherence length or the extent of the Cooper pair wave function is found to be about 20-angstrom, which is uncharacteristic of a superconducting phase realized by the BCS-phonon-retardation mechanism. The observed 40 meV kink likely reflects contributions from the frustrated spin excitations and scattering from the soft phonons. Results taken collectively provide direct clues to the nature of the pairing potential including an internal phase-shift factor in the superconducting order parameter which leads to a Brillouin zone node in a strong-coupling setting., 12 pages + 5 figures; SC order-parameter is fit to the cosKx.cosKy function (Fig-5)

MnCr2O4 that exhibits spin frustration and complex spiral spin order is of great interest from both fundamental as well as application-oriented perspectives. Unlike CoCr2O4 whose ground state presents the coexistence of commensurate spiral spin order (CSSO) and ferroelectric order, MnCr2O4 shows no multiferroicity. One reason is that the spiral spin order is highly sensitive to the oxygen concentration in MnCr2O4. Here, we have successfully grown high-quality single-crystalline MnCr2O4 by the chemical vapor transport method. We observe a new first-order magnetic transition from the incommensurate spiral spin order (ICSSO) at 19.4 K to the CSSO at 17.4 K. This magnetic transition is verified by magnetization, specific heat, and magnetoelectric measurements, which also confirm that the ground state exhibits the coexistence of the CSSO and magnetoelectricity below 17.4 K. Interestingly, the temperature evolution of Raman spectra between 5.4 and 300 K suggests that the structure remains the same. We also find that the phase-transition temperature of the CSSO decreases as applied magnetic field increases up to 45 kOe., Accepted by Phys. Rev. B

We performed susceptibility, magnetization, specific heat, and single crystal neutron diffraction measurements on single crystalline BaMn$_2$Si$_2$O$_7$. Based on the results, we revisited its spin structure with a more accurate solution and constructed a magnetic phase diagram with applied field along the $b$-axis, which contains a spin flop transition around 6 T. We also used susceptibility, magnetization, and specific heat results confirmed the ferrimagnetic-like magnetism in polycrystalline BaCo$_2$Si$_2$O$_7$. Furthermore, we performed LSDA + U calculations for the BaM$_2$Si$_2$O$_7$ (M = Cu, Co, and Mn) system. Our discussions based on the comparison among the obtained magnetic exchange interactions suggest the different structures and electronic configurations are the reasons for the different magnetic properties among the system members.

The aim of the present study was to describe the clinical features and to assess surgical treatment of intrahepatic hepatolithiasis combined with cholangiocarcinoma (IHCC). A total of 107 patients with histopathologically proven IHCC were included in the study and were divided into four groups as follows: the curative resection (CR) group, the palliative resection (PR) group, the radiofrequency ablation (RA) group, and the simple laparotomy group. Demographics, symptoms, and treatment were described and survival data were retrospectively analyzed. The overall survival rates were 45.4, 29.8, and 20.2 % at 1, 3, and 5 years. The cumulative survival rates in the CR group at 1, 3, and 5 years were 71.1, 57.9, and 50.0 %, respectively, which was significantly higher than for the other three groups (P

Electronic structure of single crystalline Ba(Zn$_{0.875}$Mn$_{0.125}$)$_{2}$As$_{2}$, parent compound of the recently founded high-temperature ferromagnetic semiconductor, was studied by high-resolution photoemission spectroscopy (ARPES). Through systematically photon energy and polarization dependent measurements, the energy bands along the out-of-plane and in-plane directions were experimentally determined. Except the localized states of Mn, the measured band dispersions agree very well with the first-principle calculations of undoped BaZn$_{2}$As$_{2}$. A new feature related to Mn 3d states was identified at the binding energies of about -1.6 eV besides the previously observed feature at about -3.3 eV. We suggest that the hybridization between Mn and As orbitals strongly enhanced the density of states around -1.6 eV. Although our resolution is much better compared with previous soft X-ray photoemission experiments, no clear hybridization gap between Mn 3d states and the valence bands proposed by previous model calculations was detected.

The aim of this study was to estimate efficacy of mechanical bowel preparation with polyethylene glycol (PEG) in prevention of postoperative complications in elective colorectal surgery. A literature search of MEDLINE (PubMed), EMBASE, and the Cochrane Library was done to identify randomized controlled trials involving comparison of postoperative complications after mechanical bowel preparation with PEG (PEG group) and no preparation (control group). A meta-analysis was set up to distinguish overall difference between the two groups. A total of five randomized controlled trials was identified according to our inclusion criteria. The use of PEG for mechanical bowel preparation did not significantly reduce the rate of surgical site infection (SSI; odds ratio (OR) 95% confidence interval (CI), 1.39 (0.85–2.25); P = 0.19) including incisional SSI (OR 95% CI, 1.44 (0.88–2.33); P = 0.15), organ/space SSI (OR 95% CI, 1.10 (0.43–2.78); P = 0.49), anastomotic leak (OR 95% CI,1.78 (0.95–3.33; P = 0.07), mortality (OR 95% CI, 1.24 (0.37–4.14; P = 0.73), infectious complications (OR 95% CI, 1.14 (0.62–2.08); P = 0.67), and hospital stay (weighted mean difference 95% CI, 2.17 (−2.90–7.25); P = 0.40) except main complications (OR 95% CI, 1.76 (1.09–2.85); P = 0.02), of which the rate increased significantly in the PEG group. The use of mechanical bowel preparation with PEG does not significantly lower postoperative complications in elective colorectal surgery.

We used immunohistochemical staining to assess protein over-expression of glial cell-derived neurotrophic factor (GDNF) and its RET receptor tyrosine kinase in patients with pancreatic cancer and benign pancreatic neoplasm, and assessed correlations with clinicopathological features and prognosis. Surgically resected pancreatic cancer patients (40/58, 68.9%) showed positive GDNF immunostaining, a significantly higher frequency than in patients with benign pancreatic tumour (3/11, 27.3%). Intrapancreatic neural invasion by cancer cells was significantly related to over-expression of GDNF. Strongly positive expression of GDNF was significantly more frequent than lesser grades of expression in patients with severe back pain before and 12 months after surgery. Expression of RET was significantly related to lymphatic invasion, survival rate after tumour resection and degree of tumour cell differentiation. We conclude that GDNF may be important in pancreatic cancer proliferation and metastasis, especially in patients with perineural invasion. Strongly positive expression of GDNF may be an indication for early intensified radiotherapy. RET expression in pancreatic cancer tissues may be a useful prognostic marker.

© 2015 American Chemical Society.In this work we prepared Li1.2Ni0.2Mn0.6O2 (LNMO) using a hydroxide co-precipitation method and investigated the effect of co-modification with NH4F and Al2O3. After surface co-modification, the first cycle Coulombic efficiency of Li1.2Ni0.2Mn0.6O2 improved from 82.7% to 87.5%, and the reversible discharge capacity improved from 253 to 287 mAh g-1 at C/20. Moreover, the rate capability also increased significantly. A combination of neutron diffraction (ND), high-resolution transmission electron microscopy (HRTEM), aberration-corrected scanning transmission electron microscopy (a-STEM)/electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS) revealed the changes of surface structure and chemistry after NH4F and Al2O3 surface co-modification while the bulk properties showed relatively no changes. These complex changes on the material's surface include the formation of an amorphous Al2O3 coating, the transformation of layered material to a spinel-like phase on the surface, the formation of nanoislands of active material, and the partial chemical reduction of surface Mn4+. Such enhanced discharge capacity of the modified material can be primarily assigned to three aspects: decreased irreversible oxygen loss, the activation of cathode material facilitated with preactivated Mn3+ on the surface, and stabilization of the Ni-redox pair. These insights will provide guidance for the surface modification in high-voltage-cathode battery materials of the future. (Figure Presented).

© 2015 American Chemical Society. The performance of battery electrode materials is strongly affected by inefficiencies in utilization kinetics and cycle life as well as size effects. Observations of phase transformations in these materials with high chemical and spatial resolution can elucidate the relationship between chemical processes and mechanical degradation. Soft X-ray ptychographic microscopy combined with X-ray absorption spectroscopy and electron microscopy creates a powerful suite of tools that we use to assess the chemical and morphological changes in lithium iron phosphate (LiFePO4) micro- and nanocrystals that occur upon delithiation. All sizes of partly delithiated crystals were found to contain two phases with a complex correlation between crystallographic orientation and phase distribution. However, the lattice mismatch between LiFePO4 and FePO4 led to severe fracturing on microcrystals, whereas no mechanical damage was observed in nanoplates, indicating that mechanics are a principal driver in the outstanding electrode performance of LiFePO4 nanoparticles. These results demonstrate the importance of engineering the active electrode material in next generation electrical energy storage systems, which will achieve theoretical limits of energy density and extended stability. This work establishes soft X-ray ptychographic chemical imaging as an essential tool to build comprehensive relationships between mechanics and chemistry that guide this engineering design.

© 2015 American Chemical Society.Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities of LiCoO2 nanorods with sizes in the range from 9 to 40 nm were studied in alkaline solution. The sides of these nanorods were terminated with low-index surfaces such as (003), while the tips were terminated largely with high-index surfaces such as (104), as revealed by high-resolution transmission electron microscopy. Electron energy loss spectroscopy demonstrated that low-spin Co3+ prevailed on the sides, while the tips exhibited predominantly high- or intermediate-spin Co3+. We correlated the electronic and atomic structure to higher specific ORR and OER activities at the tips as compared to the sides, which was accompanied by more facile redox of Co2+/3+ and higher charge transferred per unit area. These findings highlight the critical role of surface terminations and electronic structures of transition-metal oxides on the ORR and OER activity.

The proliferation of multi-core and multiprocessor-based computer systems has led to explosive development of parallel applications and hence the need for efficient schedulers. In this paper, we study hierarchical scheduling for malleable parallel jobs on multiprocessor-based systems, which appears in many distributed and multilayered computing environments. We propose a hierarchical scheduling algorithm, named AC-DS, that consists of a feedback-driven adaptive scheduler, a desire aggregation scheme and an efficient resource allocation policy. From theoretical perspective, we show that AC-DS has scalable performance regardless of the number of hierarchical levels. In particular, we prove that AC-DS achieves $O(1)$-competitiveness with respect to the overall completion time of the jobs, or the makespan. A detailed malleable job model is developed to experimentally evaluate the effectiveness of the proposed scheduling algorithm. The results verify the scalability of AC-DS and demonstrate that AC-DS outperforms other strategies for a wide range of parallel workloads.

We report the self-catalysed growth of InAs nanowires (NWs) on graphite thin films using molecular beam epitaxy via a droplet-assisted technique. Through optimising metal droplets, we obtained vertically aligned InAs NWs with highly uniform diameter along their entire length. In comparison with conventional InAs NWs grown on Si (111), the graphite surface led to significant effects on the NWs geometry grown on it, i.e. larger diameter, shorter length with lower number density, which were ascribed to the absence of dangling bonds on the graphite surface. The axial growth rate of the NWs has a strong dependence on growth time, which increases quickly in the beginning then slows down after the NWs reach a length of approximately 0.8 μm. This is attributed to the combined axial growth contributions from the surface impingement and sidewall impingement together with the desorption of adatoms during the diffusion. The growth of InAs NWs on graphite was proposed following a vapour-solid mechanism. High-resolution transmission electron microscopy reveals that the NW has a mixture of pure zinc-blende and wurtzite insertions.

We report high resolution neutron scattering measurements on the triangular lattice Mott insulator Na$_x$CrO$_2$ ($x$=1) which has recently been shown to exhibit an unusually broad fluctuating crossover regime extending far below the onset of spin freezing ($T_c\sim$41K). Our results show that below some crossover temperature ($T\sim0.75T_c$) a small incommensuration develops which helps resolve the spin frustration and drives three-dimensional magnetic order supporting coherent spin wave modes. This incommensuration assisted dimensional crossover suggests that inter-layer frustration is responsible for stabilizing the rare 2D correlated phase above 0.75$T_c$. In contrast to the host compound of 2D cobaltate superconductor such as Na$_x$CoO$_2$ ($��_c>50$��), no magnetic long-range order is observed down to 1.5K ($��_c, 5 pages, 4 figures

This work reports a physical mixture aswell as an integrated composite structure (ICS) of lithium-excess layered oxides and high voltage spinel oxides. With respect to physical mixture (PM), the improvement has shown in cycling retention. Different synthesis routes would result in drastically different properties in the composite case. The optimized composite, in comparison with the non-optimized one, both energy density and the power density have increased. The optimized composite could deliver 125 mAh/g capacity after 200 cycles at a rate of 1.2 C. Thework here provides some new insights into how to design better cathode materials for lithium ion batteries. © The Author(s) 2014. Published by ECS.

A Z2 topological insulator protected by time-reversal symmetry is realized via spin-orbit interaction driven band inversion. For example, the topological phase in the Bi-Sb system is due to an odd number of band inversions. A related spin-orbit system, the (Pb/Sn)Te class, has been known to contain an even number of inversions based on band theory. Here we experimentally investigate the possibility of a mirror symmetry protected topological crystalline insulator phase in the (Pb/Sn)Te class of materials which has been theoretically predicted to exist in its non-alloyed version. Our experimental results show that at a finite-Pb composition above the topological inversion phase transition, the surface exhibits even number of spin-polarized Dirac cone states (as opposed to odd as observed in Bi-Sb alloy or Bi2Se3) revealing mirror protected topological order distinct from that observed in Bi-Sb or Bi2Se3. Our observation of the spin-polarized Dirac surface states in the inverted (Pb/Sn)Te and their absence in the non-inverted compounds related via a topological phase transition (spin-orbit induced band inversion type) provide the experimental groundwork for opening the research on novel topological order in future quantum devices., 45 pages, 17 Figures, Earlier observation reported at http://xxx.lanl.gov/abs/1206.2088 (11th June, 2012); Expanded ver.(17 Figs) accepted for publication (in press) in Nature Communications (2012)

The progressive advancements in communication and transportation has changed human daily life to a great extent. While important advancements in battery technology has come since its first demonstration, the high energy demands needed to electrify the automotive industry have not yet been met with the current technology. One possible cathode material are the Li-rich layered oxide compounds xLi2MnO3.(1-x)LiMO2 (M= Ni, Mn, Co) (0.5=-1. In this class of compounds, lithium ions reside in both lithium layer and transition metal layer of close packed oxygen framework, typical from O3 type layered oxides like LiCoO2.1 , 2 Large irreversible capacities are often observed in these materials due to irreversible oxygen loss or side reactions stemming for the electrolyte. It has been also observed using ex-situ NMR that lithium reinsertion back into the transition metal layer is little to none. However, these studies have not revealed the dynamic process of lithium migration for the Li-rich material under operandoelectrochemical cycling conditions. Neutron scattering has several distinct advantages for battery studies: 1) The sensitivity of neutron to light elements such as lithium and oxygen are significant in order to determine their position in the crystal structure; 2) Compares to the X-ray, the neutron shows larger scattering contrast between neighboring elements in the periodic table specifically the scattering lengths; and 3) The deep penetration capability of neutron allows simultaneous observation of the cathode and anode.3 However, challenges exist in broadening the application of operando neutron diffraction for Li-ion batteries research. First, limited by the generation reactions of neutrons, the neutron flux is usually several orders of magntitude lower than X-rays. In another words, longer acquisition times as well as larger amounts of samples are required for neutron diffraction experiments. In addition, the existence of hydrogen, which has a large incoherent neutron-scattering cross-section, is detrimental to the signal-to-noise ratio of neutron diffraction pattern. Separators (polyethylene based porous membrane) and poly carbonate based electrolyte solutions contain a considerate amount of hydrogen. These two major reasons pose significant challenges to operando neutron diffraction for lithium ion battery research although it is such a powerful technique for light elements like lithium. In order to gain more in-depth insights about the lithium (de-)intercalation mechanisms in Li-rich layered oxides, track particularly the lithium ions in transition metal layer, operando neutron diffraction experiments were designed to quantitatively observe lithium migration in this type of oxides during the electrochemical process. In this study, we use amorphous silicon as an anode for the neutron diffraction battery design in order to avoid any overlap of signal that may be associated with the anode material. We perform operando neutron diffraction to probe lithium and oxygen for a high Li-rich (HLR), Li[Lix/3Ni(3/8-3x/8)Co(1/4-x/4)Mn(3/8+7x/24)O2 (x = 0.6) material, and low Li-rich (LLR), Li[Lix/3Ni(1/3-x/3)Co(1/3-x/3)Mn(1/3+x/3)O2 (x = 0.24) material with varying degrees of the high voltage plateau. In conjunction with the operando neutron diffraction, density functional theory (DFT) calculations were used to explore the incorporation of dilute oxygen vacancy, its affect on the lattice mechanics and oxygen positions. We also observe site-dependent lithium migration taking place during different stage of charging/discharge processes. Furthermore, this work demonstrates the potential of investigating dynamic changes of light elements in large format (10-100 times larger format than the typical operando cells for synchrotron X-ray diffraction) prismatic and cylindrical batteries under realistic cycling condition via operando neutron diffraction method. Acknowledgements UCSD’s efforts are supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231, Subcontract No. 7073923, under the Advanced Battery Materials Research (BMR) Program. The neutron experiments benefited from the SNS user facility, sponsored by the office of Basic Energy Sciences (BES), the Office of Science of the DOE. H.L. acknowledges the financial support from the China Scholarship Council under Award No. 2011631005. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Reference 1. H. Liu, D. Qian, M. G. Verde, M. Zhang, L. Baggetto, K. An, Y. Chen, K. J. Carroll, D. Lau, M. Chi, G. M. Veith and Y. S. Meng, Acs Appl Mater Inter, 2015, 7, 19189-19200. 2. M. G. Verde, H. D. Liu, K. J. Carroll, L. Baggetto, G. M. Veith and Y. S. Meng, Acs Appl Mater Inter, 2014, 6, 18868-18877. 3. H. D. Liu, C. R. Fell, K. An, L. Cai and Y. S. Meng, J Power Sources, 2013, 240, 772-778. Figure 1

We perform systematic angle-resolved photoemission spectroscopic measurements on the lead tin telluride Pb1-xSnxTe pseudobinary alloy system. We show that the (001) crystalline surface, which is a crystalline surface symmetric about the (110) mirror planes of the Pb1-xSnxTe crystal, pos- sesses four metallic surface states within its surface Brillouin zone. Our systematic Fermi surface and band topology measurements show that the observed Dirac-like surface states lie on the symmetric momentum-space cuts. We further show that upon going to higher electron binding energies, the surface states' isoenergetic countours in close vicinity of each X point are observed to hybridize with each other, leading to a Fermi surface fractionalization and the Lifshitz transition. In addition, systematic incident photon energy dependent measurements are performed, which enable us to un- ambiguously identify the surface states from the bulk bands. These systematic measurements of the surface and bulk electronic structure on Pb1-xSnxTe, supported by our first principles calculation results, for the first time, show that the Pb1-xSnxTe system belongs to the topological crystalline insulator phase due to the four band inversions at the L points in its Brillouin zone, which has been recently theoretically predicted., 4 pages, 4 Figures, Submitted May '12

A topological insulator protected by time-reversal symmetry is realized via spin-orbit interaction-driven band inversion. The topological phase in the Bi1-xSbx system is due to an odd number of band inversions. A related spin-orbit system, the Pb1-xSnxTe, has long been known to contain an even number of inversions based on band theory. Here we experimentally investigate the possibility of a mirror symmetry-protected topological crystalline insulator phase in the Pb1-xSnxTe class of materials that has been theoretically predicted to exist in its end compound SnTe. Our experimental results show that at a finite Pb composition above the topological inversion phase transition, the surface exhibits even number of spin-polarized Dirac cone states revealing mirror-protected topological order distinct from that observed in Bi1-xSbx. Our observation of the spin-polarized Dirac surface states in the inverted Pb1-xSnxTe and their absence in the non-inverted compounds related via a topological phase transition provide the experimental groundwork for opening the research on novel topological order in quantum devices.

Single-Dirac-cone topological insulators (TI) are the first experimentally discovered class of three dimensional topologically ordered electronic systems, and feature robust, massless spin-helical conducting surface states that appear at any interface between a topological insulator and normal matter that lacks the topological insulator ordering. This topologically defined surface environment has been theoretically identified as a promising platform for observing a wide range of new physical phenomena, and possesses ideal properties for advanced electronics such as spin-polarized conductivity and suppressed scattering. A key missing step in enabling these applications is to understand how topologically ordered electrons respond to the interfaces and surface structures that constitute a device. Here we explore this question by using the surface deposition of cathode (Cu/In/Fe) and anode materials (NO$_2$) and control of bulk doping in Bi$_2$Se$_3$ from P-type to N-type charge transport regimes to generate a range of topological insulator interface scenarios that are fundamental to device development. The interplay of conventional semiconductor junction physics and three dimensional topological electronic order is observed to generate novel junction behaviors that go beyond the doped-insulator paradigm of conventional semiconductor devices and greatly alter the known spin-orbit interface phenomenon of Rashba splitting. Our measurements for the first time reveal new classes of diode-like configurations that can create a gap in the interface electron density near a topological Dirac point and systematically modify the topological surface state Dirac velocity, allowing far reaching control of spin-textured helical Dirac electrons inside the interface and creating advantages for TI superconductors as a Majorana fermion platform over spin-orbit semiconductors., Comment: 14 pages, 4 Figures

We report high-resolution spin-resolved photoemission spectroscopy (Spin-ARPES) measurements on the parent compound Sb of the first discovered 3D topological insulator Bi{1-x}Sb{x} [D. Hsieh et al., Nature 452, 970 (2008) Submitted 2007]. By modulating the incident photon energy, we are able to map both the bulk and (111) surface band structure, from which we directly demonstrate that the surface bands are spin polarized by the spin-orbit interaction and connect the bulk valence and conduction bands in a topologically non-trivial way. A unique asymmetric Dirac surface state gives rise to a $k$-splitting of its spin polarized electronic channels. These results complement our previously published works on this materials class and re-confirm our discovery of first bulk (3D) topological insulator - topological order in bulk solids. [Invited article for NJP-IOP Focus issue on "Topological Insulators"], Comment: Invited article for NJP-IOP Focus issue on "Topological Insulators", Experimental discovery of 3D topological insulators (topological order in bulk solids) reported at KITP (2007) Conference Proceeding at http://online.itp.ucsb.edu/online/motterials07/hasan/ (2007)

Based on the standard of IEEE 802.15.4b, a cross-layer protocol design combining cluster-tree formatting and mobile routing was proposed for query-driven wireless sensor networks with mobile Sink(s). Firstly, energy consumption, network connectivity, load balancing and sub-tree depth were employed as the evaluation factors. A topology evaluation function under a multi-objective optimization model was defined to construct the stable and optimal underlying cluster-tree network. Secondly, the beacon frame scheduling based distributed sleep synchronization algorithm in IEEE 802.15.4 MAC was improved, which was used to maintain the network synchronization and topology correction on low duty-cycle. Thirdly, the parent-child relationships established during the topology formatting according to "first beacon", "best links", "top level" rules were exploited to build the two-way routing paths between mobile Sink(s) and the nodes within N-Hop range. Eventually, the topology contro l schemes at MAC layer and the query routing approach at network layer were completely implemented in the protocol stack of TinyOS. The experimental results show that the evaluation function can effectively reflect the quality of network formatting. Jointed with the sleep synchronization mechanism under the topology generated using the rule of "best links", the N-Hop reactive routing exhibits high energy-efficiency.

The development of ferromagnetism in Mn-doped Bi_2Te_3 is characterized through measurements on a series of single crystals with different Mn content. Scanning tunneling microscopy analysis shows that the Mn substitutes on the Bi sites, forming compounds of the type Bi_(2−x)Mn_xTe_3, and that the Mn substitutions are randomly distributed, not clustered. Mn doping first gives rise to local magnetic moments with Curie-like behavior, but by the compositions Bi_(1.96)Mn_(0.04)Te_3 and Bi_(1.91)Mn_(0.09)Te_3, a second-order ferromagnetic transition is observed, with T_C∼9–12 K. The easy axis of magnetization in the ferromagnetic phase is perpendicular to the Bi2Te3 basal plane. Thermoelectric power and Hall effect measurements show that the Mn-doped Bi_2Te_3 crystals are p-type. Angle-resolved photoemission spectroscopy measurements show that the topological surface states that are present in pristine Bi_2Te_3 are also present at 15 K in ferromagnetic Mn-doped Bi2−xMnxTe3 and that the dispersion relations of the surface states are changed in a subtle fashion.

The "loopless antenna" is an interventional MRI detector consisting of a tuned coaxial cable and an extended inner conductor or "whip". A limitation is the poor sensitivity afforded at, and immediately proximal to, its distal end, which is exacerbated by the extended whip length when the whip is uniformly insulated. It is shown here that tapered insulation dramatically improves the distal sensitivity of the loopless antenna by pushing the current sensitivity toward the tip. The absolute signal-to-noise ratio is numerically computed by the electromagnetic method-of-moments for three resonant 3-T antennae with no insulation, uniform insulation, and with linearly tapered insulation. The analysis shows that tapered insulation provides an approximately 400% increase in signal-to-noise ratio in trans-axial planes 1 cm from the tip and a 16-fold increase in the sensitive area as compared to an equivalent, uniformly insulated antenna. These findings are directly confirmed by phantom experiments and by MRI of an aorta specimen. The results demonstrate that numerical electromagnetic signal-to-noise ratio analysis can accurately predict the loopless detector's signal-to-noise ratio and play a central role in optimizing its design. The manifold improvement in distal signal-to-noise ratio afforded by redistributing the insulation should improve the loopless antenna's utility for interventional MRI.

The development of ferromagnetism in Mn-doped Bi2Te3 is characterized through measurements on a series of single crystals with different Mn content. Scanning tunneling microscopy analysis shows that the Mn substitutes on the Bi sites, forming compounds of the type Bi2-xMnxTe3, and that the Mn substitutions are randomly distributed, not clustered. Mn doping first gives rise to local magnetic moments with Curie-like behavior, but by the compositions Bi1.96Mn0.04Te3 and Bi1.91Mn0.09Te3 a second order ferromagnetic transition is observed, with Tc ~ 9-12 K. The easy axis of magnetization in the ferromagnetic phase is perpendicular to the Bi2Te3 basal plane. Thermoelectric power and Hall effect measurements show that the Mn-doped Bi2Te3 crystals are p-type. Angle resolved photoemission spectroscopy measurements show that the topological surface states that are present in pristine Bi2Te3 are also present in ferromagnetic Mn-doped Bi2-xMnxTe3, and that the dispersion relations of the surface states are changed in a subtle fashion.

The aim of this study was to evaluate the benefits and harms of primary closure versus T-tube drainage after common bile duct (CBD) exploration for choledocholithiasis. A literature search of MEDLINE (PubMed), EMBASE, and the Cochrane Library was done to identify randomized controlled trials assessing the benefits and harms of primary closure versus T-tube drainage after CBD exploration from Jan. 1990 to Apr. 2010. A meta-analysis was set up to distinguish overall difference between the primary closure and the T-tube drainage group. There were statistically significant differences between groups: biliary complications (odds ratio (OR) 95% confidence interval (CI), 0.42 (0.19–0.92); P = 0.03), main complications (OR 95% CI, 0.46 (0.23–0.90); P = 0.02), operating time (weighted mean difference (WMD) 95% CI, −19.53 (−29.35 to −9.71); P

Both the theoretical and experimental discovery of single-Dirac-cone topological-insulator-class was reported at arXiv:0812.2078 (2008) [Y. Xia et.al., Nature Physics 5, 398-402 (2009) http://www.nature.com/nphys/journal/v5/n6/full/nphys1294.html]. Here we report the first observation of Spin-Momentum Helical Locking and Spin-Vortex structures in Bi2Se3 and Bi2Te3, demonstrate the existence of Topological-Order at 300K and report a material realization of topological-transport-regime for helical Dirac fermions. Our results reveal a one-to-one spin-momentum locked Dirac structure in Bi2Se3 and Bi2Te3 that is nearly 100% spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers' point and can be driven to the long-sought topological-transport-regime. The observed topological nodal Dirac ground state is found to be protected even up to room temperature (300 K). Our results pave the way for future transport based studies of topological insulators, and possible room temperature applications of protected spin-polarized edge channels we observe with spin-ARPES in spintronic technology. All of these new results are made possible due to the Spin-resolved-ARPES (Mott polarimetric) technique [http://www.nature.com/nature/journal/v460/n7259/full/nature08234.html ] ., Comment: 17 pages, 4 Figures, Published nature-Online in July-2009, Submitted to NATURE in April-2009

The "loopless antenna" is an interventional MRI detector consisting of a tuned coaxial cable and an extended inner conductor or "whip". A limitation is the poor sensitivity afforded at, and immediately proximal to, its distal end, which is exacerbated by the extended whip length when the whip is uniformly insulated. It is shown here that tapered insulation dramatically improves the distal sensitivity of the loopless antenna by pushing the current sensitivity toward the tip. The absolute signal-to-noise ratio is numerically computed by the electromagnetic method-of-moments for three resonant 3-T antennae with no insulation, uniform insulation, and with linearly tapered insulation. The analysis shows that tapered insulation provides an ∼400% increase in signal-to-noise ratio in trans-axial planes 1 cm from the tip and a 16-fold increase in the sensitive area as compared to an equivalent, uniformly insulated antenna. These findings are directly confirmed by phantom experiments and by MRI of an aorta specimen. The results demonstrate that numerical electromagnetic signal-tonoise ratio analysis can accurately predict the loopless detector's signal-to-noise ratio and play a central role in optimizing its design. The manifold improvement in distal signal-to-noise ratio afforded by redistributing the insulation should improve the loopless antenna's utility for interventional MRI.

We report high-resolution spin-resolved photoemission spectroscopy (Spin-ARPES) measurements on the parent compound Sb of the recently discovered 3D topological insulator Bi1-xSbx [D. Hsieh et al., Nature 452, 970 (2008)]. By modulating the incident photon energy, we are able to map both the bulk and (111) surface band structure, from which we directly demonstrate that the surface bands are spin polarized by the spin-orbit interaction and connect the bulk valence and conduction bands in a topologically non-trivial way. A unique asymmetric Dirac surface state gives rise to a k-splitting of its spin polarized electronic channels. These results complement our previously published works on this materials class and re-confirm our discovery of topological insulator states in the Bi-Sb series., Comment: 5 pages, 5 figures

We present a polarization and topology resolved study of the low energy band structure in optimally doped superconducting Ba0.6K0.4Fe2As2 using angle resolved photoemission spectroscopy. Polarization-contrasted measurements allow us to identify and trace all low energy bands expected in models, revealing unexpected symmetry breaking and a surprisingly intertwined Fermi surface topology of hole-like bands near the Brillouin zone center. Band structure correlations across the Gamma-M spin fluctuation wavevector are compared with the superconducting gap anisotropy which suggest a partial scenario for spin-mediated interband instability contributing to superconductivity in the hole doped regime., 5 pages, 4 Figures (low-res), Submitted December 2009

When electrons are subject to a large external magnetic field, the conventional charge quantum Hall effect \cite{Klitzing,Tsui} dictates that an electronic excitation gap is generated in the sample bulk, but metallic conduction is permitted at the boundary. Recent theoretical models suggest that certain bulk insulators with large spin-orbit interactions may also naturally support conducting topological boundary states in the extreme quantum limit, which opens up the possibility for studying unusual quantum Hall-like phenomena in zero external magnetic fields. Bulk Bi{1-x}Sbx single crystals are predicted to be prime candidates for one such unusual Hall phase of matter known as the topological insulator. The hallmark of a topological insulator is the existence of metallic spin-textured surface states that are higher dimensional analogues of the edge states that characterize a quantum spin Hall insulator. Here, using incident-photon-energy-modulated angle-resolved photoemission spectroscopy, we report the direct observation of massive Dirac particles in the bulk of Bi0.9Sb0.1, locate the Kramers' points at the sample's boundary and provide a comprehensive mapping of the topological Dirac insulator's gapless surface modes. These findings taken together suggest that the observed surface state on the boundary of the bulk insulator is a realization of the much sought exotic "topological metal". They also suggest that this material has potential application in developing next-generation quantum computing devices that may incorporate "light-like" bulk carriers and topologically protected spin-textured edge-surface currents. This work is a detailed version of [Hsieh et.al., NATURE 452, 970 (2008), {Submitted in November 2007}]., 12 pages, 7 figures, This is a detailed version of the work presented at NATURE 452, 970 (2008), {Submitted in November 2007}

A topologically ordered material is characterized by a rare quantum organization of electrons that evades the conventional spontaneously broken symmetry based classification of condensed matter. Exotic spin transport phenomena such as the dissipationless quantum spin Hall effect have been speculated to originate from a novel topological order whose identification requires a spin sensitive measurement. Using Spin-resolved-ARPES, we probe the spin degrees of freedom and demonstrate that topological quantum numbers are uniquely determined from spin-texture Berry Phase imaging measurements. Applying this method to pure antimony (Sb) and Bi-Sb, we identify the origin of its novel Topological Order and the negative value of the mirror Chern number. These results taken together constitute the first observation of surface electrons collectively carrying a topological Berry's phase and definite mirror Chern chirality in pure Antimony (Sb) which are the key electronic properties for realizing topological quantum computing via the interface Majorana fermion framework. This paper contains the details of the above mentioned previously reported (Science \textbf{323}, 919 (2009)) results., Comment: 6 Figures, 10 Pages, RevTex Format, Detailed version of Hsieh et.al., SCIENCE 323, 919 (2009)

We show that the strongly spin-orbit coupled materials Bi2Te3 and Sb2Te3 (first non-Bi topological insulator) and their derivatives belong to the Z2 (Time-Reversal-Protected, elastic backscattering suppressed) topological-insulator class. Using a combination of first-principles theoretical calculations and photoemission spectroscopy, we directly show that Bi2Te3 is a large spin-orbit-induced indirect bulk band gap (about 150 meV) semiconductor whose surface is characterized by a single topological spin-Dirac cone. The electronic structure of self-doped Sb2Te3 exhibits similar Z2 topological properties. We demonstrate that the dynamics of surface spin-only Dirac fermions can be controlled through systematic Mn doping, making these materials classes potentially suitable for exploring novel topological physics. We emphasize (theoretically and experimentally) that the Dirac node is well within the bulk-gap and not degenerate with the bulk valence band., 5 Pages, 4 Figures, Accepted for publication in Physical Review Letters (submitted, June 2009)

We report cyclotron resonance (CR), transverse magnetoresistance (MR), and Hall effect studies of a series of n-type InAs1−xNx epilayers grown on GaAs with x up to 1%. The well-resolved CR absorption lines, the classical linear MR, Shubnikov–de Haas magneto-oscillations, and negative MR revealed in our experiments provide a means of probing the effect of the N atoms on the electronic properties of this alloy system and reveal qualitative differences compared to the case of the wider gap III-N-V compounds, such as GaAs1−xNx. In GaAs1−xNx electron localization by N levels that are resonant with the extended band states of the host crystal act to degrade the electrical conductivity at small x (∼0.1%). These phenomena are significantly weaker in InAs1−xNx due to the smaller energy gap and higher energy of the N levels relative to the conduction band minimum. In InAs1−xNx the electrical conductivity retains the characteristic features of transport through extended states, with electron coherence lengths (lφ∼100 nm at 2 K) and electron mobilities (μ=6×103 cm2 V−1 s−1 at 300 K) that remain relatively large even at x=1%.