The key physics of the spin valve involves spin-polarized conduction electrons propagating between two magnetic layers such that the device conductance is controlled by the relative magnetization ...orientation of two magnetic layers. Here, we report the effect of a magnon valve which is made of two ferromagnetic insulators (YIG) separated by a nonmagnetic spacer layer (Au). When a thermal gradient is applied perpendicular to the layers, the inverse spin Hall voltage output detected by a Pt bar placed on top of the magnon valve depends on the relative orientation of the magnetization of two YIG layers, indicating the magnon current induced by the spin Seebeck effect at one layer affects the magnon current in the other layer separated by Au. We interpret the magnon valve effect by the angular momentum conversion and propagation between magnons in two YIG layers and conduction electrons in the Au layer. The temperature dependence of the magnon valve ratio shows approximately a power law, supporting the above magnon-electron spin conversion mechanism. This work opens a new class of valve structures beyond the conventional spin valves.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Icotinib has been previously shown to be non-inferior to gefitinib in non-selected advanced non-small-cell lung cancer patients when given as second- or further-line treatment. In this open-label, ...randomized, phase 3 CONVINCE trial, we assessed the efficacy and safety of first-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance in lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation.
Eligible participants were adults with stage IIIB/IV lung adenocarcinoma and exon 19/21 EGFR mutations. Participants were randomly allocated (1 : 1) to receive oral icotinib or 3-week cycle of cisplatin plus pemetrexed for up to four cycles; non-progressive patients after four cycles were maintained with pemetrexed until disease progression or intolerable toxicity. The primary end point was progression-free survival (PFS) assessed by independent response evaluation committee. Other end points included overall survival (OS) and safety.
Between January 2013 and August 2014, 296 patients were randomized, and 285 patients were treated (148 to icotinib, 137 to chemotherapy). Independent response evaluation committee-assessed PFS was significantly longer in the icotinib group (11.2 versus 7.9 months; hazard ratio, 0.61, 95% confidence interval 0.43-0.87; P = 0.006). No significant difference for OS was observed between treatments in the overall population or in EGFR-mutated subgroups (exon 19 Del/21 L858R). The most common grade 3 or 4 adverse events (AEs) in the icotinib group were rash (14.8%) and diarrhea (7.4%), compared with nausea (45.9%), vomiting (29.2%), and neutropenia (10.9%) in the chemotherapy group. AEs (79.1% versus 94.2%; P < 0.001) and treatment-related AEs (54.1% versus 90.5%; P < 0.001) were significantly fewer in the icotinib group than in the chemotherapy group.
First-line icotinib significantly improves PFS of advanced lung adenocarcinoma patients with EGFR mutation with a tolerable and manageable safety profile. Icotinib should be considered as a first-line treatment for this patient population.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High-energy photons from the Crab Nebula
The Crab Nebula contains a pulsar that excites the surrounding gas to emit high-energy radiation. The combination of the pulsar's youth and nearby location ...makes the nebula the brightest gamma-ray source in the sky. The LHAASO Collaboration report observations of this source at energies of tera– to peta–electron volts, extending the spectrum of this prototypical object. They combine these data with observations at lower energies to model the physics of the emission process. The multiwave-length data can be explained by a combination of synchrotron radiation and inverse Compton scattering.
Science
, abg5137, this issue p.
425
Detection of the Crab Nebula at peta–electron volt energies constrains the gamma-ray emission mechanism.
The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar’s rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10
−4
to 1.1 peta–electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta–electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron’s size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta–electron volt electrons, 2.5 × 10
36
ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta–electron volt protons to the production of the highest-energy gamma rays.
High-β_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the ...Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-β_{θe} regime.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
The aim of this study was to determine whether Saccharomyces boulardii prevents and treats diarrhoea and antibiotic-associated diarrhoea (AAD) in children. A total of 333 hospitalised children with ...acute lower respiratory tract infection were enrolled in a 2-phase open randomised controlled trial. During the 1st phase, all children received intravenous antibiotics (AB). They were randomly allocated to group A (S. boulardii 500 mg/day + AB, n=167) or group B (AB alone, n=166) and followed for 2 weeks. Diarrhoea was defined as ≽3 loose/watery stools/day during at least 2 days, occurring during treatment and/or up to 2 weeks after AB therapy had stopped. AAD was considered when diarrhoea was caused by Clostridium difficile or when stool cultures remained negative. In the 2nd phase of the study, group B patients who developed diarrhoea were randomly allocated to two sub-groups: group B1 (S. boulardii + oral rehydration solution (ORS)) and group B2 (ORS alone). Data from 283 patients were available for analysis. Diarrhoea prevalence was lower in group A than in group B (11/139 (7.9%) vs. 42/144 (29.2%); relative risk (RR): 0.27, 95% confidence interval (CI): 0.1-0.5). S. boulardii reduced the risk of AAD (6/139 (4.3%) vs. 28/144 (19.4%); RR: 0.22; 95% CI: 0.1-0.5). When group B patients developed diarrhoea (n=42), S. boulardii treatment during 5 days (group B1) resulted in lower stool frequency (P<0.05) and higher recovery rate (91.3% in group B1 vs. 21.1% in B2; P<0.001). The mean duration of diarrhoea in group B1 was shorter (2.31±0.95 vs. 8.97±1.07 days; P<0.001). No adverse effects related to S. boulardii were observed. S. boulardii appeared to be effective in the prevention and treatment of diarrhoea and AAD in children treated with intravenous antibiotics.
ABSTRACT
High time resolution and accuracy are of critical importance in the studies of timing analysis and time delay localization of gamma-ray bursts (GRBs), soft gamma-ray repeaters (SGRs) and ...pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting of two micro-satellites, GECAM-A and GECAM-B, launched on 2020 December 10, is aimed at monitoring and locating X-ray and GRBs all over the sky. To achieve its scientific goals, GECAM is designed to have the highest time resolution (0.1 $\mu {\rm s}$) among all GRB detectors ever flown. Here, we make a comprehensive time calibration campaign including both on-ground and on-orbit tests to derive not only the relative time accuracy of GECAM satellites and detectors, but also the absolute time accuracy of GECAM-B. Using the on-ground calibration with a $\rm ^{22}Na$ radioactive source, we find that the relative time accuracy between GECAM-A and GECAM-B is about 0.15 $\mu {\rm s}$ (1σ). To measure the relative time accuracy between all detectors of a single GECAM satellite, cosmic-ray events detected on orbit are utilized since they could produce many secondary particles simultaneously record by multiple detectors. We find that the relative time accuracy among all detectors onboard GECAM-B is about 0.12 $\mu {\rm s}$ (1σ). Finally, we use the novel Li-CCF method to perform the absolute time calibration with Crab pulsar and SGR J1935+2154, both of which were jointly observed by GECAM-B and Fermi/GBM, and obtain that the time difference between GECAM-B and Fermi/GBM is 3.06 ± 6.04 $\mu {\rm s}$ (1σ).
Caged xanthones, characterized by a unique 4-oxa-tricyclo4.3.1.0(3,7)dec-2-one scaffold, are a special class of bioactive components mainly derived from the Garcinia genus (Guttiferae family). Around ...100 compounds from this family have been reported to date and most of them have potent antitumor activity, with gambogic acid being the best representative. During the past decades, inspired by the unusual caged skeleton and remarkable bioactivity, scientists from various fields have shown increasing interest on these promising natural products. In this review, the plant resources, structural characteristics, total synthesis, biological activity and mechanisms of action, structure activity relationship, and anticancer drug development of these caged xanthones are described.
Recently, a novel class of transcripts, long non-coding RNAs (lncRNAs), is being identified at a rapid pace. These RNAs have critical roles in diverse biological processes, including tumorigenesis. ...Here we report that taurine-upregulated gene 1 (TUG1), a 7.1-kb lncRNA, recruiting and binding to polycomb repressive complex 2 (PRC2), is generally downregulated in non-small cell lung carcinoma (NSCLC) tissues. In a cohort of 192 NSCLC patients, the lower expression of TUG1 was associated with a higher TNM stage and tumor size, as well as poorer overall survival (P<0.001). Univariate and multivariate analyses revealed that TUG1 expression serves as an independent predictor for overall survival (P<0.001). Further experiments revealed that TUG1 expression was induced by p53, and luciferase and chromatin immunoprecipitation (ChIP) assays confirmed that TUG1 was a direct transcriptional target of p53. TUG1 knockdown significantly promoted the proliferation in vitro and in vivo. Moreover, the lncRNA-mediated regulation of the expression of HOX genes in tumorigenesis and development has been recently receiving increased attention. Interestingly, inhibition of TUG1 could upregulate homeobox B7 (HOXB7) expression; ChIP assays demonstrated that the promoter of HOXB7 locus was bound by EZH2 (enhancer of zeste homolog 2), a key component of PRC2, and was H3K27 trimethylated. This TUG1-mediated growth regulation is in part due to specific modulation of HOXB7, thus participating in AKT and MAPK pathways. Together, these results suggest that p53-regulated TUG1 is a growth regulator, which acts in part through control of HOXB7. The p53/TUG1/PRC2/HOXB7 interaction might serve as targets for NSCLC diagnosis and therapy.
Aim To determine the efficacy and safety of caesarean section combined with temporary aortic balloon occlusion followed by uterine artery embolisation (UAE) for the treatment of patients with ...placenta accreta. Materials and methods This retrospective study involved 42 patients with placenta accreta. All patients underwent caesarean section combined with temporary aortic balloon occlusion followed by UAE through the right femoral approach. Results All patients were confirmed to have placenta praevia and accreta, including five patients with placenta percreta, at the time of delivery. The technical success rate of the combined treatment was 97.6% (41/42). Forty-one patients underwent successful caesarean section with conservation of the uterus. Hysterectomy was required in one (3.1%) patient. The amount of blood loss and blood transfusion, and the operation time were was 586 ± 355 ml, 422 ± 83 ml and 65.5 ± 10.6 minutes, respectively. The mean postoperative hospital stay, occlusion time and fetal radiation dose were 5.5 ± 2.6 days, 22.4 ± 7.2 minutes and 4.2 ± 2.9 mGy, respectively. There were no significant changes before and 7 days after the endovascular procedure in creatinine levels (56.8 ± 13.8 μmol/l versus 63.4 ± 16.7 μmol/l, p = 0.09) or urea nitrogen (6.3 ± 2.5 μmol/l versus 7.4 ± 3.8 μmol/l, p = 0.17). There were no access-site complications after the endovascular procedure and no complications related to the intervention during follow-up. Conclusion Temporary aortic balloon occlusion followed by UAE can effectively control postpartum haemorrhage during placental dissection, and reduce transfusion requirements, hysterectomy rate, and operation time in patients with placenta accreta.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This ...work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2
/
years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.
PDF
