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The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics. High-Tc cuprates crystallize into a layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn Teller effect in combination with the strong static Coulomb interaction, the octahedra in high-Tc cuprates are elongated along the c axis, leading to a 3dx²-y² orbital at the top of the band structure wherein the doped holes reside. This scenario gives rise to 2D characteristics in high-Tc cuprates that favor d-wave pairing symmetry. Here, we report superconductivity in a cuprate Ba₂CuO4-y, wherein the local octahedron is in a very exceptional compressed version. The Ba₂CuO4-y compound was synthesized at high pressure at high temperatures and shows bulk superconductivity with critical temperature (Tc ) above 70 K at ambient conditions. This superconducting transition temperature is more than 30 K higher than the Tc for the isostructural counterparts based on classical La₂CuO₄. X-ray absorption measurements indicate the heavily doped nature of the Ba₂CuO4-y superconductor. In compressed octahedron, the 3d3z²-r² orbital will be lifted above the 3dx²-y² orbital, leading to significant 3D nature in addition to the conventional 3dx²-y² orbital. This work sheds important light on advancing our comprehensive understanding of the superconducting mechanism of high Tc in cuprate materials.

Supported nanoparticles containing more than one metal have a variety of applications in sensing, catalysis, and biomedicine. Common synthesis techniques for this type of material often result in large, unalloyed nanoparticles that lack the interactions between the two metals that give the particles their desired characteristics. We demonstrate a relatively simple, effective, generalizable method to produce highly dispersed, well-alloyed bimetallic nanoparticles. Ten permutations of noble and base metals (platinum, palladium, copper, nickel, and cobalt) were synthesized with average particle sizes from 0.9 to 1.4 nanometers, with tight size distributions. High-resolution imaging and x-ray analysis confirmed the homogeneity of alloying in these ultrasmall nanoparticles.

The aim of this study was to develop a widely accepted prognostic nomogram for extranodal NK/T-cell lymphoma, nasal-type (NKTCL). The clinical data from 1383 patients with NKTCL treated at 10 participating institutions between 2000 and 2011 were reviewed. A nomogram was developed that predicted overall survival (OS) based on the Cox proportional hazards model. To contrast the utility of the nomogram against the widely used Ann Arbor staging system, the International Prognostic Index (IPI) and the Korean Prognostic Index (KPI), we used the concordance index (C-index) and a calibration curve to determine its predictive and discriminatory capacity. The 5-year OS rate was 60.3% for the entire group. The nomogram included five important variables based on a multivariate analysis of the primary cohort: stage; age; Eastern Cooperative Oncology Group performance status; lactate dehydrogenase; and primary tumor invasion. The calibration curve showed that the nomogram was able to predict 5-year OS accurately. The C-index of the nomogram for OS prediction was 0.72 for both cohorts, which was superior to the predictive power (range, 0.56–0.64) of the Ann Arbor stage, IPI and KPI in the primary and validation cohorts. The proposed nomogram provides an individualized risk estimate of OS in patients with NKTCL.

Complex-valued neural networks have many advantages over their real-valued counterparts. Conventional digital electronic computing platforms are incapable of executing truly complex-valued representations and operations. In contrast, optical computing platforms that encode information in both phase and magnitude can execute complex arithmetic by optical interference, offering significantly enhanced computational speed and energy efficiency. However, to date, most demonstrations of optical neural networks still only utilize conventional real-valued frameworks that are designed for digital computers, forfeiting many of the advantages of optical computing such as efficient complex-valued operations. In this article, we highlight an optical neural chip (ONC) that implements truly complex-valued neural networks. We benchmark the performance of our complex-valued ONC in four settings: simple Boolean tasks, species classification of an Iris dataset, classifying nonlinear datasets (Circle and Spiral), and handwriting recognition. Strong learning capabilities (i.e., high accuracy, fast convergence and the capability to construct nonlinear decision boundaries) are achieved by our complex-valued ONC compared to its real-valued counterpart. Most demonstrations of optical neural networks for computing have been so far limited to real-valued frameworks. Here, the authors implement complex-valued operations in an optical neural chip that integrates input preparation, weight multiplication and output generation within a single device.

Purpose The function of B cells in papillary thyroid cancer (PTC) is controversial. The role of B-cell-related tertiary lymphoid structures (TLSs) is still unclear. Whether B cells exert their anti-tumor effect through forming TLS in PTC needs further investigation. Methods We detected the percentage of B cells in PTC tissues by multi-parameter flow cytometry. Paraffin-embedded tumor tissues of 125 PTC patients were collected and stained with Haematoxylin–Eosin (H&E) for inflammatory infiltration analysis in combination with clinical features. Multiplexed immunohistochemistry (mIHC) was performed to verify the TLSs in above inflammatory infiltration. Correlation of B cells and TLSs with prognosis was analyzed using the TCGA database. Results We observed that PTC patients with higher expression of B lineage cell genes had improved survival and the percentage of B cells in the PTC tumor tissues was variable. Moreover, PTC tumor tissues with more B cells were surrounded by immune cell aggregates of varying sizes. We furtherly confirmed the immune cell aggregates as TLSs with different maturation stages. By analyzing PTC data from TCGA database, we found the maturation stages of TLSs were associated with genders and clinical stages among PTC patients. Moreover, patients with high TLSs survived longer and had a better prognosis. Conclusion B cells are associated with the existence of TLSs which have different maturation stages in PTC. Both B cells and TLSs are associated with the survival rate of PTC. These observations indicate that the anti-tumor effects of B cells in PTC are associated with TLSs formation.

Understanding the competition between superconductivity and other ordered states (such as antiferromagnetic or charge-density-wave (CDW) state) is a central issue in condensed matter physics. The recently discovered layered kagome metal A V 3 Sb 5 ( A  = K, Rb, and Cs) provides us a new playground to study the interplay of superconductivity and CDW state by involving nontrivial topology of band structures. Here, we conduct high-pressure electrical transport and magnetic susceptibility measurements to study CsV 3 Sb 5 with the highest T c of 2.7 K in A V 3 Sb 5 family. While the CDW transition is monotonically suppressed by pressure, superconductivity is enhanced with increasing pressure up to P1 ≈ 0.7 GPa, then an unexpected suppression on superconductivity happens until pressure around 1.1 GPa, after that, T c is enhanced with increasing pressure again. The CDW is completely suppressed at a critical pressure P2 ≈ 2 GPa together with a maximum T c of about 8 K. In contrast to a common dome-like behavior, the pressure-dependent T c shows an unexpected double-peak behavior. The unusual suppression of T c at P1 is concomitant with the rapidly damping of quantum oscillations, sudden enhancement of the residual resistivity and rapid decrease of magnetoresistance. Our discoveries indicate an unusual competition between superconductivity and CDW state in pressurized kagome lattice. The recently discovered kagome metal A V 3 Sb 5 is a new playground to study the interplay between superconductivity and charge-density-wave (CDW) state. Here, the authors report pressure-dependent evolution of CDW and superconductivity in CsV 3 Sb 5 , suggesting an unusual competition between the two phases.

In January 2013, Beijing experienced several serious haze events. To achieve a better understanding of the characteristics, sources and processes of aerosols during this month, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site between 1 January and 1 February 2013 to obtain the size-resolved chemical composition of non-refractory submicron particles (NR-PM1). During this period, the mean measured NR-PM1 mass concentration was 89.3 ± 85.6 μg m−3, and it peaked at 423 μg m−3. Positive matrix factorization (PMF) differentiated the organic aerosol into five components, including a highly oxidized, low-volatility oxygenated organic aerosol (LV-OOA), a less oxidized, semi-volatile oxygenated OA (SV-OOA), a coal combustion OA (CCOA), a cooking-related OA (COA), and a hydrocarbon-like OA (HOA), which on average accounted for 28%, 26%, 15%, 20% and 11% of the total organic mass, respectively. A detailed comparison between the polluted days and unpolluted days found many interesting results. First, the organic fraction was the most important NR-PM1 species during the unpolluted days (58%), while inorganic species were dominant on polluted days (59%). The OA composition also experienced a significant change; it was dominated by primary OA (POA), including COA, HOA and CCOA, on unpolluted days. The contribution of secondary OA (SOA) increased from 35% to 63% between unpolluted and polluted days. Second, meteorological effects played an important role in the heavy pollution in this month and differed significantly between the two types of days. The temperature and relative humidity (RH) were all increased on polluted days and the wind speed and air pressure were decreased. Third, the diurnal variation trend in NR-PM1 species and OA components showed some differences between the two types of days, and the OA was more highly oxidized on polluted days. Fourth, the effects of air masses were significantly different between the two types of days; air was mainly transported from contaminated areas on the polluted days. The comparison also found that the aerosol was more acidic on polluted days. Additionally, the variation trends of the mass concentration and mass fractions of NR-PM1 species and OA components were more dramatic when the NR-PM1 mass loading was at a higher level. The serious pollution observed in this month can be attributed to the synergy of unfavorable meteorological factors, the transport of air masses from high-pollution areas, emission by local sources, and other factors.

The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), features several major advances from the original MERRA reanalysis, including the use, outside of high latitudes, of observations-based precipitation data products to correct the precipitation falling on the land surface in the MERRA-2 system. The method for merging the observed precipitation into MERRA-2 has been refined from that of the (land-only) MERRA-Land reanalysis. This paper describes the method and evaluates the MERRA-2 land surface precipitation. Compared to monthly GPCPv2.2 observations, the corrected MERRA-2 precipitation (M2CORR) is better than the precipitation generated by the atmospheric models within the cycling MERRA-2 and MERRA systems. M2CORR is also better than MERRA-Land precipitation over Africa because in MERRA-2 a merged satellite–gauge precipitation product is used instead of the gauge-only data used for MERRA-Land. Compared to 3-hourly TRMM observations, the M2CORR diurnal cycle has better amplitude but less realistic phasing than MERRA-2 model-generated precipitation. Because correcting the precipitation within the coupled atmosphere–land modeling system allows the MERRA-2 near-surface air temperature and humidity to respond to the improved precipitation forcing, MERRA-2 provides more self-consistent surface meteorological data than were available from MERRA-Land, which is important for applications such as land-only modeling studies. Where precipitation observations of sufficient quality are available for use in the reanalysis, the corrections facilitate the seamless spinup of the land surface initial conditions across the MERRA-2 production streams. At high latitudes, however, the lack of reliable precipitation observations results in undesirable land spinup effects that impact mostly the first published year of each MERRA-2 stream (1980, 1992, 2001, and 2011).

The recent development of ultrashort laser pulses allows for optical control of structural and electronic properties of complex quantum materials. The layered transition-metal dichalcogenideMoTe2, which can crystallize into several different structures with distinct topological and electronic properties, provides possibilities to control or switch between different phases. In this study, we report a photoinduced subpicosecond structural transition between the type-II Weyl semimetal phase and normal-semimetal phase in bulk crystallineMoTe2by using ultrafast pump-probe and time-resolved second-harmonic-generation spectroscopy. The phase transition is most clearly characterized by the dramatic change of the shear oscillation mode and the intensity loss of second-harmonic generation. This work opens up new possibilities for ultrafast manipulation of the topological properties of solids, enabling potentially practical applications for a topological switch device with ultrafast excitations.

Explosives are often exposed to war environments at different temperatures. The shock initiation characteristics of explosives are related to their properties and the ambient temperature in which they are located. In the present work, the parameters of the Ignition and Growth model of the LX-04 explosive at different temperatures are determined, based on the shock initiation experiments at different temperatures. Furthermore, the impact sensitivity simulation of LX-04 at initial temperatures of 25, 60, 100, 150, and 170°C is carried out, and the critical impact velocity at these initial temperatures is found to be 325, 280, 233, 201, and 194 m/s, respectively. Based on the present simulation data, a new model for the relationship between the critical impact velocity and initial temperature is proposed. In addition, the initial temperature of the explosive has an important effect on the detonation performance: the higher the initial temperature, the higher the impact sensitivity of LX-04, and the higher the peak temperature of detonation.