Coexistence of Interacting Charge Density Waves in a Layered Semiconductor.

Coexisting orders are key features of strongly correlated materials and underlie many intriguing phenomena from unconventional superconductivity to topological orders. Here, we report the coexistence of two interacting charge-density-wave (CDW) orders in EuTe_{4}, a layered crystal that has drawn considerable attention owing to its anomalous thermal hysteresis and a semiconducting CDW state despite the absence of perfect Fermi surface nesting. By accessing unoccupied conduction bands with time- and angle-resolved photoemission measurements, we find that monolayers and bilayers of Te in the unit cell host different CDWs that are associated with distinct energy gaps. The two gaps display dichotomous evolutions following photoexcitation, where the larger bilayer CDW gap exhibits less renormalization and faster recovery. Surprisingly, the CDW in the Te monolayer displays an additional momentum-dependent gap renormalization that cannot be captured by density-functional theory calculations. This phenomenon is attributed to interlayer interactions between the two CDW orders, which account for the semiconducting nature of the equilibrium state. Our findings not only offer microscopic insights into the correlated ground state of EuTe_{4} but also provide a general nonequilibrium approach to understand coexisting, layer-dependent orders in a complex system.

Probing

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

Unconventional Hysteretic Transition in a Charge Density Wave.

Hysteresis underlies a large number of phase transitions in solids, giving rise to exotic metastable states that are otherwise inaccessible. Here, we report an unconventional hysteretic transition in a quasi-2D material, EuTe_{4}. By combining transport, photoemission, diffraction, and x-ray absorption measurements, we observe that the hysteresis loop has a temperature width of more than 400 K, setting a record among crystalline solids. The transition has an origin distinct from known mechanisms, lying entirely within the incommensurate charge density wave (CDW) phase of EuTe_{4} with no change in the CDW modulation periodicity. We interpret the hysteresis as an unusual switching of the relative CDW phases in different layers, a phenomenon unique to quasi-2D compounds that is not present in either purely 2D or strongly coupled 3D systems. Our findings challenge the established theories on metastable states in density wave systems, pushing the boundary of understanding hysteretic transitions in a broken-symmetry state.

Emerging salt marshes as a source of Trichoderma arenarium sp. nov. and other fungal bioeffectors for biosaline agriculture.

AIMS: Sustainable agriculture requires effective and safe biofertilizers and biofungicides with low environmental impact. Natural ecosystems that closely resemble the conditions of biosaline agriculture may present a reservoir for fungal strains that can be used as novel bioeffectors. METHODS AND RESULTS: We isolated a library of fungi from the rhizosphere of three natural halotolerant plants grown in the emerging tidal salt marshes on the south-east coast of China. DNA barcoding of 116 isolates based on the rRNA ITS1 and 2 and other markers (tef1 or rpb2) revealed 38 fungal species, including plant pathogenic (41%), saprotrophic (24%) and mycoparasitic (28%) taxa. The mycoparasitic fungi were mainly species from the hypocrealean genus Trichoderma, including at least four novel phylotypes. Two of them, representing the taxa Trichoderma arenarium sp. nov. (described here) and T. asperelloides, showed antagonistic activity against five phytopathogenic fungi, and significant growth promotion on tomato seedlings under the conditions of saline agriculture. CONCLUSIONS: Trichoderma spp. of salt marshes play the role of natural biological control in young soil ecosystems with a putatively premature microbiome. SIGNIFICANCE AND IMPACT OF THE STUDY: The saline soil microbiome is a rich source of halotolerant bioeffectors that can be used in biosaline agriculture.

[The expression of Nrf2 in the lung tissue of rats with acute diquat poisoning and the distribution of diquat in lungs].

Objective: To investigate the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in the lung tissue of rats with acute diquat (DQ) poisoning and the distribution of diquat in lungs. Methods: Fifty-four fasted male Wistar rats were randomized into control group (n=6) and exposure group (n=48) . According to the time point, the exposure group was divided into 2 h, 4 h, 12 h, 1 d, 3 d, 7 d, 11 d and 14 d groups with 6 rats in each group. Exposure groups were administered 11.55 mg/kg DQ (1 ml/100 g BW) by single-dose of intragastric administration, while the control group rats were given normal saline. The histopathological changes of lung tissue of rats in each group were observed. The expression of nrf2 in lung tissue was detected by immunohistochemistry, and the diquat concentration in lungs was determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) . Results: In the exposure group, DQ was detected in lungs on 2 hours after poisoning. The concentration of DQ in lung tissue decreased gradually over time, and there was no accumulation in lung tissue. The histopathological changes of lung tissue were not obvious in the early stage of poisoning. The injury was the most serious on the 3rd day, a large number of inflammatory cells could be seen in alveolar cavity and lung stroma, and the pathological injury of lung tissue began to be alleviated on the 7th day. The results of immunohistochemistry showed that Nrf2 was mainly expressed in the nucleus of pulmonery cells. The expression of Nrf2 in the exposure group was significantly higher than the control group. The expression of Nrf2 increased significantly at the 12th hour (P<0.05) , reached the peak on the 3rd day (P<0.05) . There was no difference between the control group and the 14th day (P>0.05) . Conclusion: There was no accumulation of DQ in the lung tissue for a long time, and there was a hysteresis in lung injury induced by redox reaction of DQ. Nrf2 was highly expressed in the lung tissue of rats with acute DQ poisoning, which was correlated with histopathology injury of lung tissue, suggesting that Nrf2 plays an important role in antagonizing acute lung injury induced by DQ.

Association of von Willebrand factor (vWF) expression with lymph node metastasis and hemodynamics in papillary thyroid carcinoma.

OBJECTIVE: The purpose of this study was to analyze the relationship between von Willebrand factor (vWF) expression and lymph node metastasis or hemodynamics parameters in PTC. This work will provide a novel biomarker for the diagnosis of papillary thyroid carcinoma (PTC). PATIENTS AND METHODS: A total of 156 PTC patients were divided into metastatic and non-metastatic groups based on the presence or absence of lymph node metastasis. The Adler blood flow grading, color doppler flow imaging (CDFI), and blood flow index (PSV, PI, RI, AT) were measured and analyzed between the two groups. The expression of vWF was examined by immunocytochemical assay and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). The function of vWF was investigated by methyl thiazolyl tetrazolium (MTT) and the transwell assays. RESULTS: Both metastatic and non-metastatic groups with the major Adler grades as 0-1 had abundant blood flows. There was a significant difference in the rate of lymph node metastasis between Adler 2-3 and Adler 0-1. Moreover, the expression of vWF was found to be associated with lymph node metastasis or Adler blood flow grade in PTC. Significant differences in peak systolic velocity (PSV), systolic acceleration time (AT), and resistance index (RI) were detected in metastatic and non-metastatic groups. In addition, the upregulation of vWF was positively correlated with PSV, RI, and PI in PTC. Functionally, the knockdown of vWF inhibited the development of PTC by suppressing cell proliferation, migration, and invasion. CONCLUSIONS: Abnormal expression of vWF is closely related to lymph node metastasis and hemodynamics parameters in PTC patients. Furthermore, vWF plays an oncogene role in PTC progression.

Dirac nodal surfaces and nodal lines in ZrSiS.

Topological semimetals are characterized by symmetry-protected band crossings, which can be preserved in different dimensions in momentum space, forming zero-dimensional nodal points, one-dimensional nodal lines, or even two-dimensional nodal surfaces. Materials harboring nodal points and nodal lines have been experimentally verified, whereas experimental evidence of nodal surfaces is still lacking. Here, using angle-resolved photoemission spectroscopy (ARPES), we reveal the coexistence of Dirac nodal surfaces and nodal lines in the bulk electronic structures of ZrSiS. As compared with previous ARPES studies on ZrSiS, we obtained pure bulk states, which enable us to extract unambiguously intrinsic information of the bulk nodal surfaces and nodal lines. Our results show that the nodal lines are the only feature near the Fermi level and constitute the whole Fermi surfaces. We not only prove that the low-energy quasiparticles in ZrSiS are contributed entirely by Dirac fermions but also experimentally realize the nodal surface in topological semimetals.

Low-temperature microstructural studies on superconducting CaFe2As2.

Undoped CaFe2As2 (Ca122) can be stabilized in two slightly different non-superconducting tetragonal phases, PI and PII, through thermal treatments. Upon proper annealing, superconductivity with a Tc up to 25 K emerges in the samples with an admixture of PI and PII phases. Systematic low-temperature X-ray diffraction studies were conducted on undoped Ca122 samples annealed at 350 °C over different time periods. In addition to the diffraction peaks associated with the single-phase aggregation of PI and PII, a broad intermediate peak that shifts with annealing time was observed in the superconducting samples only. Our simulation of phase distribution suggests that the extra peak is associated with the admixture of PI and PII on the nanometer scale. High-resolution transmission electron microscopy confirms the existence of these nano-scale phase admixtures in the superconducting samples. These experimental results and simulation analyses lend further support for our conclusion that interfacial inducement is the most reasonable explanation for the emergence of superconductivity in undoped Ca122 single crystals.

FABP4 accelerates glioblastoma cell growth and metastasis through Wnt10b signalling.

OBJECTIVE: Glioblastomas are one of the most dangerous types of malignancies because of their metastatic capacity and challenge to treat with chemotherapy or radiotherapy. Hence, detailed research to explain the molecular mechanisms of glioblastoma metastasis is crucial to improve glioblastoma treatment. PATIENTS AND METHODS: The expression level of fatty acid-binding protein 4 (FABP4) in glioblastoma cell lines and tissues was detected by Western blotting and quantitative Real-time polymerase chain reaction (qRT-PCR) assays. Proliferation assay, colon formation analysis and transwell/migration assay were performed to detect the relationship between FABP4 and malignant behaviors of glioblastoma cells in vitro. Subcutaneous xenograft and intravenous metastasis models were used to determine the role of FABP4 in vitro. Rescue assays were conducted to confirm the contribution of Wingless-Type MMTV Integration Site Family, Member 10B (Wnt10b) to the progression of glioblastoma cells regulated by FABP4. RESULTS: Glioblastoma cells exhibited a higher level of FABP4 expression than control cells, and down-regulation of FABP4 suppressed tumor cell growth and metastasis in vitro and in vivo. Wnt10b, as a regulator gene of FABP4, restored the effects of FABP4 down-regulation in glioblastoma cells. CONCLUSIONS: We provided substantive evidence that FABP4 is a growth and metastasis promoter in vivo and revealed that it functions in part through Wnt10b, which suggests that FABP4 might act as a probable target to block glioblastoma metastasis.

Effects of lipopeptide carboxymethyl chitosan nanoparticles on Staphylococcus aureus biofilm.

This study aims to evaluate the effect of lipopeptide carboxymethyl chitosan nanoparticles on Staphylococcus aureus biofilm as part of the development of a new anti-biofilm material. The study had three stages. Firstly, we assessed the Staphylococcus aureus capability to form biofilm and enumerated the number of attached bacteria and free bacteria; secondly, we determined the inhibitory effect of different concentrations of Bacillus natto antimicrobial lipopeptid- carboxymethyl chitosan (BNAP-CMCS) nanoparticles added at different times on biofilm formation capability and the numbers of free bacteria and attached bacteria. Lastly, we tested the scavenging effect of BNAP-CMCS nanoparticles on biofilm formation and number of attached bacteria. The results showed that the amount of attached bacteria quickly increased over time and reached the maximum after 24 h of culture. The BNAP-CMCS nanoparticles had the greatest effect on biofilm inhibition at the concentration of 1 MIC, after 8 h of culture, and the effect was dose-dependent. The BNAP-CMCS nanoparticles had decreased also the numbers of free and attached bacteria in a dose-dependent fashion, after 8 hours of culture. The scavenging effect of BNAP-CMCS nanoparticles on free and attached bacteria was maximum at 6 MIC. In conclusion, lipopeptide carboxymethyl chitosan nanoparticles had a good inhibition and scavenging effect on the formation of Staphylococcus aureus biofilm and the growth of surface-attached bacteria.

Comparisons of external fixator combined with limited internal fixation and open reduction and internal fixation for Sanders type 2 calcaneal fractures: Finite element analysis and clinical outcome.

OBJECTIVES: The aim of this study was to compare the biomechanical stability and clinical outcome of external fixator combined with limited internal fixation (EFLIF) and open reduction and internal fixation (ORIF) in treating Sanders type 2 calcaneal fractures. METHODS: Two types of fixation systems were selected for finite element analysis and a dual cohort study. Two fixation systems were simulated to fix the fracture in a finite element model. The relative displacement and stress distribution were analysed and compared. A total of 71 consecutive patients with closed Sanders type 2 calcaneal fractures were enrolled and divided into two groups according to the treatment to which they chose: the EFLIF group and the ORIF group. The radiological and clinical outcomes were evaluated and compared. RESULTS: The relative displacement of the EFLIF was less than that of the plate (0.1363 mm to 0.1808 mm). The highest von Mises stress value on the plate was 33% higher than that on the EFLIF. A normal restoration of the Böhler angle was achieved in both groups. No significant difference was found in the clinical outcome on the American Orthopedic Foot and Ankle Society Ankle Hindfoot Scale, or on the Visual Analogue Scale between the two groups (p > 0.05). Wound complications were more common in those who were treated with ORIF (p = 0.028). CONCLUSIONS: Both EFLIF and ORIF systems were tested to 160 N without failure, showing the new construct to be mechanically safe to use. Both EFLIF and ORIF could be effective in treating Sanders type 2 calcaneal fractures. The EFLIF may be superior to ORIF in achieving biomechanical stability and less blood loss, shorter surgical time and hospital stay, and fewer wound complications.Cite this article: M. Pan, L. Chai, F. Xue, L. Ding, G. Tang, B. Lv. Comparisons of external fixator combined with limited internal fixation and open reduction and internal fixation for Sanders type 2 calcaneal fractures: Finite element analysis and clinical outcome. Bone Joint Res 2017;6:433-438. DOI: 10.1302/2046-3758.67.2000640.

Observation of three-component fermions in the topological semimetal molybdenum phosphide.

In quantum field theory, Lorentz invariance leads to three types of fermion-Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

Distinct Evolutions of Weyl Fermion Quasiparticles and Fermi Arcs with Bulk Band Topology in Weyl Semimetals.

The Weyl semimetal phase is a recently discovered topological quantum state of matter characterized by the presence of topologically protected degeneracies near the Fermi level. These degeneracies are the source of exotic phenomena, including the realization of chiral Weyl fermions as quasiparticles in the bulk and the formation of Fermi arc states on the surfaces. Here, we demonstrate that these two key signatures show distinct evolutions with the bulk band topology by performing angle-resolved photoemission spectroscopy, supported by first-principles calculations, on transition-metal monophosphides. While Weyl fermion quasiparticles exist only when the chemical potential is located between two saddle points of the Weyl cone features, the Fermi arc states extend in a larger energy scale and are robust across the bulk Lifshitz transitions associated with the recombination of two nontrivial Fermi surfaces enclosing one Weyl point into a single trivial Fermi surface enclosing two Weyl points of opposite chirality. Therefore, in some systems (e.g., NbP), topological Fermi arc states are preserved even if Weyl fermion quasiparticles are absent in the bulk. Our findings not only provide insight into the relationship between the exotic physical phenomena and the intrinsic bulk band topology in Weyl semimetals, but also resolve the apparent puzzle of the different magnetotransport properties observed in TaAs, TaP, and NbP, where the Fermi arc states are similar.

XRN2 promotes EMT and metastasis through regulating maturation of miR-10a.

MicroRNAs (miRNAs) have been proposed as critical regulatory molecules in the epithelial-mesenchymal transition (EMT) program. However, the roles of mature miRNA biogenesis during EMT process needs to be defined. Here we determined that increased expression of XRN2 induced EMT and promoted metastasis in vitro and in vivo. Furthermore, we uncovered that XRN2 functions as pro-metastatic gene, which accelerates miR-10a maturation by binding pre-miR-10a in a DICER-independent manner. These findings suggest that XRN2 is a novel regulator of EMT that contributes to the metastatic processes in lung cancer through a novel miRNA regulatory mechanism.

Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic.

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ[over ¯] is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

Successful management of primary splenic pregnancy: a case report and review of literature.

Ectopic pregnancy is defined as dislocation of a fertilized ovum anywhere other than in the cavity of uterus. Generally, the common site for dislocation is within fallopian tube, accounting for 95.5% of all ectopic gestations. Abdominal pregnancy is rare with a potentially life-threatening variation that resides within peritoneal cavity and the primary splenic pregnancy is even rarer. This report describes a patient with primary splenic pregnancy, who was successfully managed after splenectomy.

Characterization and comparison of transgenic Artemisia annua GYR and wild-type NON-GYR plants in an environmental release trial.

The anti-malarial drug, artemisinin, is quite expensive as a result of its slow content in Artemisia annua. Recent investigations have suggested that genetic engineering of A. annua is a promising approach to improve the yield of artemisinin. In this study, the transgenic A. annua strain GYR, which has high artemisinin content, was evaluated in an environmental release trial. First, GYR plants were compared with the wild-type variety NON-GYR, with regard to phenotypic characters (plant height, crown width, stem diameter, germination rate, leaf dry weight, 1000-seed weight, leave shape). Second, stress resistance in the two varieties (salt, drought, herbicide, and cold resistance) was evaluated under different experimental conditions. Finally, gene flow was estimated. The results indicated that there were significant differences in several agronomic traits (plant height, stem diameter, and leave dry weight) between the transgenic GYR and NON-GYR plants. Salt stress in transgenic and control plants was similar, except under high NaCl concentrations (1.6%, w/w). Leaf water, proline, and MDA content (increased significantly) were significantly different. Transgenic A. annua GYR plants did not grow better than NON-GYR plants with respect to drought and herbicide resistance. The two varieties maintained vitality through the winter. Third, gene flow was studied in an environmental risk trial for transgenic GYR. The maximum gene flow frequency was 2.5%, while the maximum gene flow distance was 24.4 m; gene flow was not detected at 29.2 m at any direction. Our findings may provide an opportunity for risk assessment in future commercialization of transgenic A. annua varieties.

Interleukin-6 -572G/C polymorphism and prostate cancer susceptibility.

Strong evidence suggests that cancer-associated inflammation promotes tumor growth and progression, and interleukin-6 (IL6) is an important modulator of inflammation. However, the roles of IL6 and mutations of its corresponding gene in prostate cancer have not been clearly documented. We retrieved data from the Oncomine database concerning IL6 expression in prostate cancer and its role in prostate-specific antigen (PSA) recurrence. We also performed a case-control study of the IL6 -572G/C polymorphism (rs1800796) in 236 sporadic prostate cancer patients and 256 healthy controls from a southern Han Chinese population. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between rs1800796 and prostate cancer susceptibility. A dual-luciferase reporter assay was used to test the transcriptional activity of the IL6 promoter G and C alleles. IL6 was overexpressed in prostate cancer tissues compared to normal tissues, especially in those with higher Gleason scores. Moreover, elevated IL6 expression was associated with high PSA recurrence rate in Oncomine data. Our case-control study demonstrated that compared with the -572C allele, the -572G allele conferred a borderline increased risk of prostate cancer (OR = 1.31, 95%CI = 0.99-1.74, P = 0.061). This was more pronounced in the subgroup of individuals having never smoked (OR = 1.85, 95%CI = 1.07-3.22). Moreover, the G allele showed increased activity relative to the C allele in the dual-luciferase reporter assay. Our results suggest that the -572G/C polymorphism may be associated with IL6 expression, which in turn plays a role in prostate cancer development.

Research trends and perspectives of male infertility: a bibliometric analysis of 20 years of scientific literature.

To carry out an in-depth analysis of the scientific research on male infertility, we performed the first bibliometric analysis focusing on studies involving male infertility worldwide during the period 1995-2014. Analysis of 6357 articles in the field of male infertility showed a significant increasing trend in the number of publications over the period 1995-2014. Obstetrics and Gynecology was an important subject category and Multidisciplinary Sciences was the newest interest. Authors were mainly from Europe and USA, with researchers from Cleveland Clinic producing the most articles, and those from the Tel Aviv Sourasky Medical Center and the University of Utah having the highest-quality articles. The USA contributed the most independent and international collaborative articles. The Cleveland Clinic and the University of Munster were the most productive institutions. The Cleveland Clinic and the University of Giessen had the most international collaboration publications. Harvard University had the most collaborators. The most common interests were pathogenesis and therapy, and new interests were hypogonadism, obesity, and cryopreservation. In conclusion, rapid development of the male infertility field was observed. Overall, collaborative and multidisciplinary science research has become more popular. The USA and its institutions play a dominant role, followed by European countries. Thanks to the common research focus worldwide, more insight into male fertility has been gained in the scientific literature over the past 20 years. [Correction added on September 21, 2016, after online publication: the term "institute" has been replaced by the term "institution" throughout the text.].

Momentum-Resolved Electronic Structure of the High-T_{c} Superconductor Parent Compound BaBiO_{3}.

We investigate the band structure of BaBiO_{3}, an insulating parent compound of doped high-T_{c} superconductors, using in situ angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO_{6} breathing distortions. Though the distortions are often thought to coincide with Bi^{3+}/Bi^{5+} charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth 6s states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O 2p orbitals.