Search

Two-dimensional (2D) topological insulators (TIs) are promising platforms for low-dissipation spintronic devices based on the quantum-spin-Hall (QSH) effect, but experimental realization of such systems with a large band gap suitable for room-temperature applications has proven difficult. Here, we report the successful growth on bilayer graphene of a quasi-freestanding WSe2 single layer with the 1T' structure that does not exist in the bulk form of WSe2. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we observe a gap of 129 meV in the 1T' layer and an in-gap edge state located near the layer boundary. The system's 2D TI characters are confirmed by first-principles calculations. The observed gap diminishes with doping by Rb adsorption, ultimately leading to an insulator-semimetal transition. The discovery of this large-gap 2D TI with a tunable band gap opens up opportunities for developing advanced nanoscale systems and quantum devices.

Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here we report a study of TiTe2 from the single-layer to the bulk limit. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermi level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe2, despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation.Due to reduced dimensionality, the properties of 2D materials are often different from their 3D counterparts. Here, the authors identify the emergence of a unique charge density wave (CDW) order in monolayer TiTe2 that challenges the current understanding of CDW formation.

Two-dimensional (2D) topological insulators (TIs) are promising platforms for lowdissipation spintronic devices based on the quantum-spin-Hall (QSH) effect, but experimental realization of such systems with a large band gap suitable for room-temperature applications has proven difficult. Here, we report the successful growth on bilayer graphene of a quasi-freestanding WSe2 single layer with the 1T' structure that does not exist in the bulk form of WSe2. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we observe a gap of 129 meV in the 1T' layer and an in-gap edge state located near the layer boundary. The system's 2D TI characters are confirmed by first-principles calculations. The observed gap diminishes with doping by Rb adsorption, ultimately leading to an insulator-semimetal transition. The discovery of this large-gap 2D TI with a tunable band gap opens up opportunities for developing advanced nanoscale systems and quantum devices. [ABSTRACT FROM AUTHOR]

Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here we report a study of TiTe2 from the single-layer to the bulk limit. Using angleresolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermi level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe2, despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation. [ABSTRACT FROM AUTHOR]

Circular dichroism (CD) observed by photoemission, being sensitive to the orbital and spin angular momenta of the electronic states, is a powerful probe of the nontrivial surface states of topological insulators, but the experimental results thus far have eluded a comprehensive description. We report a study of Bi2Te3 films with thicknesses ranging from one quintuple layer (two-dimensional limit) to 12 layers (bulk limit) over a wide range of incident photon energy. The data show complex variations in magnitude and sign reversals, which are nevertheless well described by a theoretical calculation including all three photoemission mechanisms: dipole transition, surface photoemission, and spin-orbit coupling. The results establish the nontrivial connection between the spin-orbit texture and CD. [ABSTRACT FROM AUTHOR]

This experiment was conducted to determine the influences of supplementing different levels of an additive containing lutein in the diet of Chinese Holstein lactating cows on production performance, antioxidative plasma metabolites, and milk quality. This study was performed on 60 multiparous Holstein dairy cows in peak lactation. The cows were randomly allocated to 1 of 4 homogeneous treatments, with lutein preparation (extracted from marigolds; effective lutein content was 2%) added at levels of 0, 100, 150, and 200 g/d per head, with the actual available amounts being 0, 2, 3, and 4 g of lutein/d per head, respectively. The experiment lasted for 13 wk, with the first week for adaptation. Milk yield and milk compositions were recorded weekly, and milk concentrations of lutein, dry matter intake, and antioxidative blood index were analyzed in the first, fourth, seventh, and thirteenth week of the study. The results showed that adding lutein in the diet had no effect on dry matter intake compared with the control group; however, it slowed down the trend of decline in milk yield, and had a linear incremental effect on milk yield with increasing concentration of lutein. Dietary lutein tended to quadratically increase the percentage of milk fat, and linearly increased milk lactose concentration, with the highest value when treated at 200 g of lutein preparation/d per head, and decreased somatic cell count, with the lowest values when treated with 150 and 200 g of lutein preparation/d per head. The concentration of lutein in milk linearly increased with the incorporation of the additive, with a value of 0.59, 0.70, 1.20, and 1.50 μg/100 mL when treated with 0, 100, 150, and 200 g/d, respectively. Total plasma antioxidant capacity tended to linearly increase in cows fed lutein preparation, whereas plasma superoxide dismutase and glutathione peroxidase activities did not differ significantly. In conclusion, addition of lutein in the diet could improve the production performance and health status of dairy cows. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical efficacy of transoral robotic surgery (TORS) with the da Vinci robot system in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Methods: A mixed cohort study was conducted to collect and analyze the clinical data of OPSCC patients who underwent TORS at the Eye & ENT Hospital, Fudan University between July 2020 and February 2023 (TORS group). OPSCC patients who underwent conventional surgery between January 2016 and September 2020 were included as the control group. The baseline information, incidence of complications and follow-up data were compared between the two groups. Results: A total of 166 patients were included, with 102 cases (81 males and 21 females) in the TORS group [mean age: (59.1±9.8) years] and 64 cases (54 males and 10 females) in the control group [ mean age: (57.6±9.7) years]. Compared with the control group, the TORS group had lower postoperative bleeding rate [2.9% (3/102) vs 10.9% (7/64), P =0.035] and infection rate [1.0% (1/102) vs 18.8% (12/64), P <0.001]. No statistically significant differences were observed in tracheotomy rate [46.1% (47/102) vs 59.4% (38/64), P =0.070] and median length of hospital stay [8 (7, 10) d vs 10 (4, 12) d, P =0.088]. After propensity score matching, compared with the control group, the TORS group had lower postoperative infection rate [0 (0/31) vs 19.4% (6/31), P =0.032] and median length of hospital stay [7 (7, 10) d vs 10 (8, 12) d, P =0.031]. No statistically significant differences were found in postoperative bleeding rate [3.2% (1/31) vs 6.5% (2/31), P =1.000] and tracheotomy rate [22.6% (7/31) vs 45.2% (14/31), P =0.060] between the two groups. Moreover, 1-and 2-year disease-free survival rates were 96.3% and 94.6% in the TORS group, and 90.6% and 84.3% in the control group, respectively ( P =0.233). The 1-and 2-year cancer-specific survival rates were both 100% in the TORS group, and 96.9% and 93.8% in the control group, respectively ( P =0.539). Conclusion: TORS for OPSCC is associated with high clinical safety and favorable oncological outcomes.

Objective: To evaluate the objective response rate (ORR) of induction chemoimmunotherapy with camrelizumab plus TPF (docetaxel, cisplatin, and capecitabine) for locally advanced hypopharyngeal squamous cell carcinoma (LA HSCC) and potential predictive factors for ORR. Methods: A single-center, prospective, phase 2 and single-arm trial was conducted for evaluating antitumor activity of camrelizumab+TPF(docetaxel+cisplatin+capecitabine) for LA HSCC between May 21, 2021 and April 15, 2023, patients admitted to the Eye & ENT Hospital affiliated with Fudan University. The primary endpoint was ORR, and enrolled patients with LA HSCC at T3-4N0-3M0 received induction chemoimmunotherapy for three cycles: camrelizumab 200 mg day 1, docetaxel 75 mg/m 2 day 1, cisplatin 25 mg/m 2 days 1-3, and capecitabine 800 mg/m 2 days 1-14. Patients were assigned to radioimmunotherapy when they had complete response or partial response (PR)>70% (Group A), or assigned to surgery plus adjuvant radiotherapy/chemoradiotherapy when they had PR≤70% (Group B), and the responses were defined by using tumor volume evaluation system. Tumor diameter was also used to assess the treatment responses by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Use SPSS 23.0 software was used to analyze the data. Results: A total of 51 patients were enrolled who underwent the induced chemoimmunotherapy for three cycles, and all were males, aged 35-69 years old. After three cycles of induction immunochemotherapy, 42 (82.4%) patients existed in Group A (complete response or PR>70%) and 9 patients (17.6%) in Group B (PR≤70%), the ORR was 82.4%. The primary endpoint achieved expected main research objectives. Compared to the patients of Group A, the patients of Group B showed the higher T stage and the larger volume of primary tumor before induced immunochemotherapy, and also had the less regression of tumor volume after induced immunochemotherapy (all P <0.05). The optimal cutoff value of pre-treatment tumor volume for predicting ORR was 39 cm 3 . The T stage ( OR =12.71, 95% CI : 1.4-112.5, P =0.022) and the volume ( OR =7.1, 95% CI : 1.4-36.8, P =0.018) of primary tumor were the two main factors affecting ORR rate of induction chemoimmunotherapy. Conclusion: The induction chemoimmunotherapy with camrelizumab plus TPF shows an encouraging antitumor efficacy in LA HSCC.

Objective: To evaluate the relationship of serum uric acid with prediabetes and newly detected type 2 diabetes mellitus (T2DM) in adults. Methods: Data were obtained from the baseline investigation of Songjiang Peak-Plan cohort. According to the baseline fasting plasma glucose and glycosylated hemoglobin, the eligible subjects were divided into normal blood sugar group, prediabetes group, and newly detected T2DM group. Unconditional logistic regression model was used to explore the effect of serum uric acid level on prediabetes and newly detected T2DM, and restricted cubic spline (RCS) function was used to explore the nonlinear dose-response relationship of serum uric acid level with the prevalence of prediabetes and newly detected T2DM. Results: A total of 30 375 subjects were included in the analysis, with an average age of (55.36±11.52) years, and 60.2% (18 299) of them were women. The baseline survey found that the prevalence of prediabetes was 38.6% (11 739 cases), and the prevalence of newly detected T2DM was 6.6% (1 992 cases). Logistic regression analysis showed that, in women, for every 10µmol/L increase in serum uric acid, the risk of developing prediabetes and T2DM s increased by 2.4% ( OR =1.024, 95% CI : 1.018-1.030), and 1.5% ( OR =1.015, 95% CI : 1.005-1.025), respectively; in men, for every 10 µmol/L increase in serum uric acid, the risk of developing prediabetes and T2DM decreased by 0.8% ( OR =0.992, 95% CI : 0.987-0.998) and 5.0% ( OR =0.950, 95% CI : 0.939-0.960), respectively. The RCS function showed that the serum uric acid level showed a nonlinear dose-response relationship with newly detected T2DM ( P =0.017), but not with prediabetes ( P =0.670) in women and showed a nonlinear dose-response relationship with both prediabetes ( P =0.040) and newly detected T2DM ( P <0.001) in men. Conclusions: Adult women are at increased risk of prediabetes and newly detected T2DM with increase of serum uric acid level, and adult men are at decreased risk of newly diagnosed T2DM with the increase of serum uric acid level. There was no significant relationship between serum uric acid level and prediabetes in men.