251 research outputs found

    Excitonic condensation for the surface states of topological insulator bilayers

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    We propose a generic topological insulator bilayer (TIB) system to study the excitonic condensation with self-consistent mean-field (SCMF) theory. We show that the TIB system presents the crossover behavior from the Bardeen-Cooper-Schrieffer (BCS) limit to Bose-Einstein condensation (BEC) limit. Moreover, by comparison with traditional semiconductor systems, we find that for the present system the superfluid property in the BEC phase is more sensitive to electron-hole density imbalance and the BCS phase is more robust. Applying this TIB model into Bi2_{2}Se3_{3}-family material, we find that the BEC phase is most probable to be observed in experiment. We also calculate the critical temperature for Bi2_{2}Se3_{3}-family TIB system, which is ∼100\mathtt{\sim}100 K. More interestingly, we can expect this relative high-temperature excitonic condensation since our calculated SCMF critical temperature is approximately equal to the Kosterlitz-Thouless transition temperature.Comment: 11 NJP pages, 7 figure

    The Prospects for Immigration Amendments

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    Obg proteins are a family of P-loop GTPases, conserved from bacteria to human. The Obg protein in Escherichia coli (ObgE) has been implicated in many diverse cellular functions, with proposed molecular roles in two global processes, ribosome assembly and stringent response. Here, using pre-steady state fast kinetics we demonstrate that ObgE is an anti-association factor, which prevents ribosomal subunit association and downstream steps in translation by binding to the 50S subunit. ObgE is a ribosome dependent GTPase; however, upon binding to guanosine tetraphosphate (ppGpp), the global regulator of stringent response, ObgE exhibits an enhanced interaction with the 50S subunit, resulting in increased equilibrium dissociation of the 70S ribosome into subunits. Furthermore, our cryo-electron microscopy (cryo-EM) structure of the 50S? ObgE? GMPPNP complex indicates that the evolutionarily conserved N-terminal domain (NTD) of ObgE is a tRNA structural mimic, with specific interactions with peptidyl-transferase center, displaying a marked resemblance to Class I release factors. These structural data might define ObgE as a specialized translation factor related to stress responses, and provide a framework towards future elucidation of functional interplay between ObgE and ribosome-associated (p) ppGpp regulators. Together with published data, our results suggest that ObgE might act as a checkpoint in final stages of the 50S subunit assembly under normal growth conditions. And more importantly, ObgE, as a (p) ppGpp effector, might also have a regulatory role in the production of the 50S subunit and its participation in translation under certain stressed conditions. Thus, our findings might have uncovered an under-recognized mechanism of translation control by environmental cues

    Time duration of post-activation performance enhancement (PAPE) in elite male sprinters with different strength levels

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    (1) Purpose: This study aimed to explore the time duration of post-activation performance enhancement (PAPE) in elite male sprinters with different strength levels. (2) Methods: Thirteen elite male sprinters were divided into a strong group (relative strength: 1RM squat normalized by body mass of ≥ 2.5; n = 6) and a weak group (relative strength of < 2.5; n =7). All sprinters performed one static squat jump (SSJ) at baseline and 15 s, 3 min, 6 min, 9 min, and 12 min following an exercise protocol including three reps of a 90% 1RM back squat. Two force plates were used to determine the vertical jump height, the impulse output, and the power output for all SSJs. (3) Results: Significant improvements in vertical jump height and peak impulse were observed (p < 0.05) at 3, 6, and 9 min, without significant between-group differences. The peak power had a significant increase in 3 min (p < 0.01) and 6 min (p < 0.05), with also no significant difference between-group differences. Moreover, the stronger subjects induced a greater PAPE effect than the weaker counterparts at 3, 6, and 9 min after the intervention. The maximal benefit following the intervention occurred at 6 min and 3 min after the intervention in the stronger and weaker subjects, respectively. (4) Conclusions: The findings indicated that three reps of a 90% 1RM back squat augmented the subsequent explosive movement (SSJ) for 3–9 min in elite male sprinters, especially in stronger sprinters.info:eu-repo/semantics/publishedVersio

    Challenges of fully online learning for dermatology education: a retrospective study

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    BackgroundBlended learning has proven to be an effective teaching strategy. During the COVID-19 pandemic in 2019, educational institutions worldwide switched to online learning. However, there is limited research on the effectiveness of blended learning and fully online learning. This study aims to evaluate and compare whether pure online learning is as effective as traditional blended learning by taking the example of dermatology education.MethodsThe researchers compared traditional blended learning and fully online learning by evaluating the achievement scores of undergraduate students in a dermatology course in the academic years 2019 and 2020, respectively, at the Shandong First Medical University, China. In 2019, students undertook small private online courses (SPOCs) combined with face-to-face teacher-led learning. In 2020, live teacher-led learning replaced face-to-face teacher-led learning. The researchers also conducted a questionnaire survey in 2020.ResultsThe scores of students in 2019 were significantly higher than in 2020 (p = 0.002). There was no significant difference in the distribution of achievement variance in the scores between the two academic years. In the questionnaire survey, the majority of the students rated highly the fully online education mode and responded that pure online learning enhanced their self-study ability.ConclusionThe present study shows that fully online learning currently does not perform as well as traditional blended learning in terms of examination scores due to some limitations. However, pure online education has several advantages over traditional blended education. Online courses should be improved to ignite students’ interest and increase their learning efficiency

    The efficacy of furmonertinib in untreated advanced NSCLC patients with sensitive EGFR mutations in a real-world setting: a single institutional experience

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    BackgroundFurmonertinib is the standard treatment option in the first-line setting for advanced non-small cell lung cancer (NSCLC) with sensitive epidermal growth factor receptor (EGFR) mutations in China. However, there are limited real-world data available.MethodsWe conducted a retrospective study at a single center, analyzing a cohort of 73 NSCLC patients who tested positive for EGFR mutations and were treated with furmonertinib as their initial therapy between August 2022 and December 2023. The primary endpoint was progression-free survival (PFS), with secondary endpoints including objective response rate (ORR), overall survival (OS), and safety profile.ResultsThe median observation period was 9 months (95% confidence interval [CI], 8.0–20.0). The median PFS was 19.5 months (95% CI, 14.6–24.4). OS data were not yet mature. Univariate analysis showed no significant correlation between PFS and factors such as Eastern Cooperative Oncology Group performance status (ECOG PS) score, presence of brain or liver metastases, sex, age, EGFR mutation status, or number of metastatic sites. However, multivariate analysis indicated a potential trend toward extended PFS in patients younger than 65 years (p = 0.053, 95% CI, 0.10–1.02), although the p-value was only marginally significant. The most common adverse events were diarrhea (24%), anemia (36%), and liver injury (32%); however, only four cases experienced severe adverse events.ConclusionIn a real-world setting, furmonertinib appears to be a favorable treatment option for EGFR-mutated patients. The manageable nature of adverse events further supports its use in clinical practice

    Advanced HCC with amplified mesenchymal epithelial transition factor receptor responds well to savolitinib: a case report

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    ObjectiveCurrent treatment agents for HCC are mostly immune checkpoint inhibitors (ICIs) plus bevacizumab and multitarget tyrosine kinase inhibitors (TKIs); however, their limited overall response rate and shorter median progression-free survival (PFS) discourage their frequent use. The development of Mesenchymal Epithelial Transition Factor receptor (MET) Tyrosine Kinase Inhibitors (MET-TKI) has transformed the treatment pattern in MET-altered solid tumors and improved their prognosis. However, the benefits of MET-TKIs in MET-amplified hepatocellular carcinoma (HCC) remain unclear.MethodsHere, we present a case of advanced HCC amplified with MET treated with savolitinib, a MET-TKI, after progression from first-line treatment with bevacizumab plus sintilimab.ResultsThe patient achieved a partial response (PR) to savolitinib in the second line setting. The progression-free survival (PFS) of first-line of bevacizumab plus sintilimab and sequential second-line treatment with MET-TKI, savolitinib, are 3 and over 8 months, respectively. furthermore, the patient still had continuous PR status with manageable toxicities.ConclusionsThe present case report provides first-hand evidence that savolitinib may be beneficial for patients with advanced MET-amplified HCC and offers a promising treatment option

    Corrigendum: Case Report: Durable response to immuno-chemotherapy in a case of ROS1 fusion-positive advanced lung adenocarcinoma: A case report

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    Immune checkpoint inhibitors (ICIs) have greatly transformed the treatment and improved the prognosis for patients with non-small cell lung cancer (NSCLC) without driver gene alterations. However, the effects of ICI combination therapy in ROS1 fusion-positive NSCLC remains unclear. Herein, we present a case with ROS1 fusion-positive NSCLC treated with ICI plus chemotherapy. The patient achieved a continuous partial response (PR) to ICI plus chemotherapy and a more than 35 months progression free survival. This case demonstrates that ICI plus chemotherapy is a promising option for patients with ROS1 fusion-positive NSCLC

    An (E,E)-α-farnesene synthase gene of soybean has a role in defence against nematodes and is involved in synthesizing insect-induced volatiles

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    Plant terpene synthase genes (TPSs) have roles in diverse biological processes. Here, we report the functional characterization of one member of the soybean TPS gene family, which was designated GmAFS. Recombinant GmAFS produced in Escherichia coli catalysed the formation of a sesquiterpene (E,E)-a-farnesene. GmAFS is closely related to (E,E)-a-farnesene synthase gene from apple, both phylogenetically and structurally. GmAFS was further investigated for its biological role in defence against nematodes and insects. Soybean cyst nematode (SCN) is the most important pathogen of soybean. The expression of GmAFS in a SCN-resistant soybean was significantly induced by SCN infection compared with the control, whereas its expression in a SCN-susceptible soybean was not changed by SCN infection. Transgenic hairy roots overexpressing GmAFS under the control of the CaMV 35S promoter were generated in an SCN-susceptible soybean line. The transgenic lines showed significantly higher resistance to SCN, which indicates that GmAFS contributes to the resistance of soybean to SCN. In soybean leaves, the expression of GmAFS was found to be induced by Tetranychus urticate (two-spotted spider mites). Exogenous application of methyl jasmonate to soybean plants also induced the expression of GmAFS in leaves. Using headspace collection combined with gas chromatography–mass spectrometry analysis, soybean plants that were infested with T. urticae were shown to emit a mixture of volatiles with (E,E)-a-farnesene as one of the most abundant constituents. In summary, this study showed that GmAFS has defence roles in both below-ground and above-ground organs of soybean against nematodes and insects, respectively
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