The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10
electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV ...energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays
. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref.
). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane
, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.
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.
The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray ...observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9} GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.
Hyalinizing clear cell carcinoma (HCCC) is an extremely rare neoplasm of salivary gland origin with a low-grade indolent nature. It is difficult to distinguish from other malignant salivary gland ...tumours. Clinical outcomes following surgery are generally reported as good. The aim of this study was to further determine the features of HCCC. This study was approved by Medical ethics review of affiliated hospital of jiangsu university. Fourteen new cases of HCCC are reported. The clinical and histopathological data of these 14 cases were analysed alongside those of 141 cases identified in a systematic review of the literature (up to 2016). Demographic data, histopathological findings, clinical presentation, primary treatment, and outcomes were extracted. Histologically, HCCC tumour cells had a clear cell morphology with hyalinized stroma. Immunohistochemical results were positive for cytokeratins and EMA, but negative for SMA, S100, vimentin, and calponin. Twelve of the 14 patients showed EWSR1 translocation. Local nodal metastasis on presentation was present in 17.3% and the overall recurrence rate was 17.7% in the total population (N=155), compared with 35.7% and 21.4%, respectively, in the new cases alone. Focal necrosis and local metastasis were identified as possibly associated with recurrence. The overall prognosis was good: only 3.8% of patients died of the disease. HCCC is less indolent than was previously thought, but overall the prognosis is good. Risk factors for recurrence may include focal necrosis and local metastasis at presentation. The best treatment for patients with HCCC is wide local excision combined with regional lymph node dissection.
We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China ...Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.
Summary
Background
The optimal dosage of intravenous proton pump inhibitors (PPIs) for the prevention of peptic ulcer rebleeding remains unclear.
Aim
To compare the rebleeding rate of high‐dose and ...standard‐dose PPI use after endoscopic haemostasis.
Methods
A total of 201 patients with bleeding ulcers undergoing endoscopic treatment with epinephrine injection and heater probe thermocoagulation were randomised to receive a high‐dose regimen (80 mg bolus, followed by pantoprazole 8 mg/h infusion, n = 100) or a standard‐dose regimen (pantoprazole 40 mg bolus daily, n = 101). After 72 h, all patients were given 40 mg pantoprazole daily orally for 27 days.
Results
There were no statistical differences in mean units of blood transfused, length of hospitalisation ≦5 days, surgical or radiological interventions and mortality within 30 days between two groups. Bleeding recurred within 30 days in six patients 6.2%, 95% confidence interval (CI) 1.3–11.1% in the high‐dose group, as compared to five patients (5.2%, 95% CI 0.6–9.7%) in the standard‐dose group (P = 0.77). The stepwise Cox regression analysis showed end‐stage renal disease, haematemesis, chronic obstructive pulmonary disease (hazard ratio: 37.15, 10.07, 9.12, 95% CI: 6.76–204.14, 2.07–49.01, 1.66–50.00 respectively) were independent risk factors for rebleeding and Helicobacter pylori infection was associated with lower risk of rebleeding (hazard ratio: 0.20, 95% CI: 0.04–0.94).
Conclusions
Following combined endoscopic haemostasis of bleeding ulcers, co‐morbidities, haematemesis and H. pylori Status, but not PPI dosage, are associated with rebleeding (http://www.Clinical Trials.gov.ID: NCT00709046).
Alzheimer's disease (AD), the most common type of irreversible dementia, is predicted to affect 152 million people by 2050. Evidence from large-scale preventive randomized controlled trials (RCTs) on ...modifiable risk variables in Europe has shown that multi-domain lifestyle treatments for older persons at high risk of dementia may be practical and effective. Given the substantial differences between the Chinese and European populations in terms of demographics and living conditions, direct adoption of the European program in China remains unfeasible. Although a RCT has been conducted in China previously, its participants were mainly from rural areas in northern China and, thus, are not representative of the entire nation.There is an urgent need to establish cohorts that represent different economic, cultural, and geographical situations in order to explore implementation strategies and evaluate the effects of early multi-domain interventions more comprehensively and accurately.
We developed an integrated intervention procedure implemented in urban neighborhood settings, namely China Initiative for Multi-Domain Intervention (CHINA-IN-MUDI). CHINA-IN-MUDI is a 2-year multicenter open-label cluster-randomised controlled trial centered around a Chinese-style multi-domain intervention to prevent cognitive decline. Participants aged 60-80 years were recruited from a nationally representative study, i.e. China Healthy Aging and Dementia Study cohort. An external harmonization process was carried out to preserve the original FINGER design. Subsequently, we standardized a series of Chinese-style intervention programs to align with cultural and socioeconomic status. Additionally, we expanded the secondary outcome list to include genomic and proteomic analyses. To enhance adherence and facilitate implementation, we leveraged an e-health application.
Screening commenced in July 2022. Currently, 1,965 participants have been randomized into lifestyle intervention (n = 772) and control groups (n = 1,193). Both the intervention and control groups exhibited similar baseline characteristics. Several lifestyle and vascular risk factors were present, indicating a potential window of opportunity for intervention. The intervention will be completed by 2025.
This project will contribute to the evaluation of the effectiveness and safety of intervention strategies in controlling AD risk and reducing clinical events, providing a basis for public health decision-making in China.
AIMS: To investigate the medium‐pressure (MP) and low‐pressure (LP) Ultraviolet (UV) susceptibility and the repair potential of Enterococcus faecalis (DSM 20478) after UV treatment. METHODS AND ...RESULTS: A range of UV doses from 4 to 19 mJ cm⁻² was selected in this study. Photoreactivation and dark repair performance were investigated under fluorescent light or in the dark respectively. The inactivation and repair performance of UV disinfection under a range of salinities (0, 1%, 3%) and temperature (4 and 25°C) were compared. Results indicated that MP UV exposure resulted in higher inactivation efficiency against Ent. faecalis than LP UV exposure. For repair potential, LP UV resulted in a greater level of light repair than MP UV. Effect of salinity on the inactivation and repair of Ent. faecalis was correlated with UV sources, whereas low temperature generally adversely affected the inactivation efficiency and final repair levels after both MP and LP UV exposure. CONCLUSIONS: Both salinity and temperature demonstrated to play an important role in the inactivation and repair capability when UV light was used to treat ballast water. SIGNIFICANCE AND IMPACT OF THE STUDY: Considering that UV‐treated ballast water is exposed or discharged to marine water environment in many countries with various temperature and salinity conditions, results of this study provide significant implications for the management of public health associated with ballast water treatment and discharge.
Developing advanced building materials with both excellent thermal insulating and optical properties to replace common glass (thermal conductivity of ∼1 W m–1 K–1) is highly desirable for ...energy-efficient applications. The recent development of transparent wood suggests a promising building material with many advantages, including high optical transmittance, tunable optical haze, and excellent thermal insulation. However, previous transparent wood materials generally have a high haze (typically greater than 40%), which is a major obstacle for their practical application in the replacement of glass. In this work, we fabricate a clear wood material with an optical transmittance as high as 90% and record-low haze of 10% using a delignification and polymer infiltration method. The significant removal of wood components results in a highly porous microstructure, much thinner wood cell walls, and large voids among the cellulose fibrils, which a polymer can easily enter, leading to the dense structure of the clear wood. The separated cellulose fibrils that result from the removal of the wood components dramatically weaken light scattering in the clear wood, which combined with the highly dense structure produces both high transmittance and extremely low haze. In addition, the clear wood exhibits an excellent thermal insulation property with a low thermal conductivity of 0.35 W m–1 K–1 (one-third of ordinary glass); thus, the application of clear wood can greatly improve the energy efficiency of buildings. The developed clear wood, combining excellent thermal insulating and optical properties, represents an attractive alternative to common glass toward energy-efficient buildings.
Alloying is an effective method to strengthen high entropy alloys (HEAs). Unfortunately, most of the investigations focus on the perspective of experiments and few are available from the perspective ...of atomic and electrical scale such as electronic structure, energy band structure and charge density. In present work, first-principle calculation based on density functional theory was employed to calculate the ground state total energy, lattice parameters, elastic constants and polycrystal modulus of NbMoTaW and NbMoTaWV refractory high entropy alloys (RHEAs). The effects of V addition on the phase structure, elastic properties and electronic structure of NbMoTaW-based RHEAs were studied, respectively. V addition is helpful to improve the mechanical properties of NbMoTaW alloy according to the calculated value of shear modulus to bulk modulus, Cauchy pressure and Vickers hardness. Based on calculated energy band, electronic state density, charge density and charge density difference, V addition is found to shorten the pseudo-energy gap and enhance interaction force between Mo and W atoms. This tends to improve the mechanical properties of the alloy. The calculated results were in good agreement with the experimental data, demonstrating that the methods were effective in predicting the performance of RHEAs.
•V strengthening of NbMoTaW HEA was investigated from perspective of atomic and electrical scale.•Interaction of orbitals electrons between V and Nb–Mo–Ta–W is stronger than that among Nb–Mo–Ta–W.•V addition enhances the bonding strength and improves mechanical properties of NbMoTaW RHEA.
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