734 research outputs found

    Suppression of Superconductivity by Twin Boundaries in FeSe

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    Low-temperature scanning tunneling microscopy and spectroscopy are employed to investigate twin boundaries in stoichiometric FeSe films grown by molecular beam epitaxy. Twin boundaries can be unambiguously identified by imaging the 90{\deg} change in the orientation of local electronic dimers from Fe site impurities on either side. Twin boundaries run at approximately 45{\deg} to the Fe-Fe bond directions, and noticeably suppress the superconducting gap, in contrast with the recent experimental and theoretical findings in other iron pnictides. Furthermore, vortices appear to accumulate on twin boundaries, consistent with the degraded superconductivity there. The variation in superconductivity is likely caused by the increased Se height in the vicinity of twin boundaries, providing the first local evidence for the importance of this height to the mechanism of superconductivity.Comment: 6 pages, 7 figure

    Risk factors of distant brain failure for patients with newly diagnosed brain metastases treated with stereotactic radiotherapy alone

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    <p>Abstract</p> <p>Objective</p> <p>To explore the risk factors of distant brain failure (DBF) for patients with brain metastasis (BM) who were treated with stereotactic radiotherapy alone and to group the patients on the basis of their risk levels.</p> <p>Methods and Materials</p> <p>We retrospectively analyzed 132 newly diagnosed BM patients who were treated with stereotactic radiotherapy alone from May 2000 to April 2010. Kaplan-Meier and Cox proportional hazards regression analyses were performed for univariate and multivariate analyses.</p> <p>Results</p> <p>The 1-year incidence rate of DBF was 44.7%, and the median DBF time (MDBFT) was 18 months. In multivariate analysis, the risk factors of DBF were the number of BMs greater than 1 (p = 0.041), uncontrolled extracranial disease (p = 0.005), interval time (IT) of less than 60 months between the diagnosis of primary tumor and BM (p = 0.024), and total volume of BM was greater than 6 cc (p = 0.049). Each risk factor was assigned 1 score. The median survival times for the patients with scores of 0-1, 2-3, and 4 were 31, 12, and 10 months, respectively, and the corresponding MDBFTs were not reached, 13, and 3 months, respectively, (p < 0.001). The crude DBF incidence rates in patients with scores of 0-1, 2-3, and 4 were 14.8%, 50.0%, and 76.9%, respectively, (p < 0.001).</p> <p>Conclusions</p> <p>The patients with scores of 0-1 had a lower risk of DBF than the patients with higher scores did, and it may be reasonable to treat these patients with SRS alone and resort to whole-brain radiation therapy only for salvage. The patients with a score of 4 had the highest risk of developing DBF after stereotactic radiotherapy alone, these patients may be candidates for initial whole-brain radiation therapy or clinical trials. The patients with a score of 2-3 had a moderate risk of developing DBF, SRT alone combined with close clinical monitoring would be the optimal treatment regimen for such patients, and for those patients with difficulties in receiving close clinical mornitoring, SRT combined with WBRT will be more suitable.</p

    Disitamab Vedotin plus anti-PD-1 antibody show good efficacy in refractory primary urethral cancer with low HER2 expression: a case report

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    Primary urethral carcinoma (PUC) has a low incidence, but with high aggressiveness. Most of the patients are found in late stage, with poor prognosis. At present, chemotherapy is still the main treatment for metastatic PUC, but it has limited effect. Here, we report a case of metastatic PUC with low HER2 expression that developed disease progression after multiline therapy including chemotherapy, programmed death-1 (PD-1) inhibitors and multi-targeted receptor tyrosine kinase (RTK) inhibitor. After receiving Disitamab Vedotin(a novel antibody drug conjugate, ADC) and toripalimab (a PD-1 inhibitor), the patient achieved persistent PR, and the PFS exceeded 12 months up to now. Our report indicates that, despite the patient of metastatic PUC has low expression of HER2, it is still possible to benefit from Disitamab Vedotin combined with PD-1 inhibitor, which may reverse the drug resistance of PD-1 inhibitor and chemotherapy to a certain extent. But larger sample studies are needed to determine the efficacy of this treatment strategy and its impact on survival

    catena-Poly[[[tetra­aqua­manganese(II)]-μ-4,4′-bipyridine] bis­(3-hydroxy­cinnamate) dihydrate]

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    The title compound, {[Mn(C10H8N2)(H2O)4](C9H7O3)2·2H2O}n, was obtained by the hydro­thermal reaction of manganese chloride with mixed 3-hydroxy­lcinnamic acid (H2 L) and 4,4′-bipyridine (4,4′-bipy) ligands. The structure contains [Mn(C10H8N2)(H2O)4]2+ cations with the MnII atoms lying on a centres of inversion and bridged into a linear chain along the a axis by 4,4′-bipy ligands, surrounded by HL − anions and uncoordinated water mol­ecules. Extensive O—H⋯O hydrogen-bonding and weak π–π inter­actions [centroid–centroid distance = 3.7572  (3) Å] between the constituents lead to the formation of a three-dimensional supra­molecular network

    PI3K/Akt pathway: a potential therapeutic target for chronic pain

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    Chronic pain is among the most disabling and costly disorders, with prevalence ranging from 10% to 55%. However, current therapeutic strategies for chronic pain are unsatisfactory due to our poor understanding of its mechanisms. Thus, novel therapeutic targets need to be found in order to improve these patients' quality of life. PI3K and its downstream Akt are widely expressed in the spinal cord, particularly in the laminae I-IV of the dorsal horn, where nociceptive C and Aδ fibers of primary afferents principally terminate. Recent studies have demonstrated their critical roles in the development and maintenance of chronic pain. In this review, we summarized the roles and mechanisms of PI3K/Akt pathway in the progression of chronic pain through sciatic nerve injury, diabetic neuropathy, spinal cord injury, bone cancer, opioid tolerance, or opioid-induced hyperalgesia

    Isolation and characterization of Edwardsiella ictaluri strains as pathogens from diseased yellow catfish Pelteobagrus fulvidraco (Richardson) cultured in China

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    Yellow catfish Pelteobagrus fulvidraco (Richardson) is a commercially important fish generally distributed in Southeast Asian countries. The well-known aetiological agent of enteric septicaemia of catfish, Edwardsiella ictaluri, was isolated from diseased yellow catfish P. fulvidraco (Richardson) reared at two commercial fisheries in China. The economic losses due to the high mortalities (about 50%) caused by this bacterium have been increasing annually. The affected fish presented two different, typical symptoms: pale gills, slight exophthalmia and a 'hole in the head', and haemorrhage on the opercula, in the skin under the jaw, creating a 'hole under the jaw'. These diseases were found frequently in cultured yellow catfish throughout China. The isolates from both outbreaks were all Gram negative, facultatively anaerobic and short rod. Morphological and biochemical tests and phylogenetic analysis based on the 16S rDNA sequences all strongly indicated that these yellow catfish isolates were highly identical to the known E. ictaluri. In addition, the isolates possessed the typical plasmid profile of E. ictaluri. Experimental infection assays were conducted and pathogenicity (by an intraperitoneal injection) was demonstrated in yellow catfish and channel catfish Ictalurus punctatus. The results showed that yellow catfish isolates were quite conservative pheno-typically and genetically, and were able to cause two different, typical symptoms in this fish under unknown conditions and mechanism

    Imaging the Electron-Boson Coupling in Superconducting FeSe Films Using a Scanning Tunneling Microscope

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    Scanning tunneling spectroscopy has been used to reveal signatures of a bosonic mode in the local quasiparticle density of states of superconducting FeSe films. The mode appears below Tc as a “dip-hump” feature at energy Ω∼4.7kBTc beyond the superconducting gap Δ. Spectra on strained regions of the FeSe films reveal simultaneous decreases in Δ and Ω. This contrasts with all previous reports on other high-Tc superconductors, where Δ locally anticorrelates with Ω. A local strong coupling model is found to reconcile the discrepancy well, and to provide a unified picture of the electron-boson coupling in unconventional superconductors.Physic

    Highly Variable Recessive Lthal or Nearly Lethal Mutation Rates During Germ-Line Development of Male Drosophila Melanogaster

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    Each cell of higher organism adults is derived from a fertilized egg through a series of divisions, during which mutations can occur. Both the rate and timing of mutations can have profound impacts on both the individual and the population, because mutations that occur at early cell divisions will affect more tissues and are more likely to be transferred to the next generation. Using large-scale multigeneration screening experiments for recessive lethal or nearly lethal mutations of Drosophila melanogaster and recently developed statistical analysis, we show for male D. melanogaster that (i) mutation rates (for recessive lethal or nearly lethal) are highly variable during germ cell development; (ii) first cell cleavage has the highest mutation rate, which drops substantially in the second cleavage or the next few cleavages; (iii) the intermediate stages, after a few cleavages to right before spermatogenesis, have at least an order of magnitude smaller mutation rate; and (iv) spermatogenesis also harbors a fairly high mutation rate. Because germ-line lineage shares some (early) cell divisions with somatic cell lineage, the first conclusion is readily extended to a somatic cell lineage. It is conceivable that the first conclusion is true for most (if not all) higher organisms, whereas the other three conclusions are widely applicable, although the extent may differ from species to species. Therefore, conclusions or analyses that are based on equal mutation rates during development should be taken with caution. Furthermore, the statistical approach developed can be adopted for studying other organisms, including the human germ-line or somatic mutational patterns

    Research on the Quality Evaluation of Commercial Whole Grain Dried Noodles

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    This paper aims to comprehensively analyze quality features of commercial whole grain dried noodles and provide data reference for the formulation standards of whole grain dried noodles. 41 commercial whole grain dried noodles collected in 2019 and 2020 are analyzed and evaluated in this research.The moisture content is from 9.77% to 13.06%, while the acidity value between 0.00 to 4.46 mL per10 g,with a naturally broken ratio from 0.04% to 4.05%. The cooked broken ratio is from 0.00% to 3.33%. The cooked broken ratio of 90% whole grain noodle samples is 0%, with the cooking loss ratio between 2.46%and 11.36%. Taking the limits of the above indexes in LS/T 3212—2014 as the reference, except the acidity of 2 samples and the cooking loss rate of 4 samples which are beyond the limit values, all indexes of other samples meet the requirements. The total dietary fiber content is between 2.22 to 12.37 g per 100 g and the alkylresorcinols content is between 10.08 μg/g and 218.52 μg/g. The integral level of moisture content,acidity and alkylresorcinols content of samples in 2020 is higher than that in 2019, and the cooking loss rate is the lower, while there is no significant difference between two years’ samples in other indexes. The results show that the quality of commercial whole grain dried noodles varies greatly
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