86 research outputs found
Bandgap engineering of organic semiconductors for highly efficient photocatalytic water splitting
The bandgap engineering of semiconductors, in particular low‐cost organic/polymeric photocatalysts could directly influence their behavior in visible photon harvesting. However, an effective and rational pathway to stepwise change of the bandgap of an organic/polymeric photocatalyst is still very challenging. An efficient strategy is demonstrated to tailor the bandgap from 2.7 eV to 1.9 eV of organic photocatalysts by carefully manipulating the linker/terminal atoms in the chains via innovatively designed polymerization. These polymers work in a stable and efficient manner for both H2 and O2 evolution at ambient conditions (420 nm < λ < 710 nm), exhibiting up to 18 times higher hydrogen evolution rate (HER) than a reference photocatalyst g‐C3N4 and leading to high apparent quantum yields (AQYs) of 8.6%/2.5% at 420/500 nm, respectively. For the oxygen evolution rate (OER), the optimal polymer shows 19 times higher activity compared to g‐C3N4 with excellent AQYs of 4.3%/1.0% at 420/500 nm. Both theoretical modeling and spectroscopic results indicate that such remarkable enhancement is due to the increased light harvesting and improved charge separation. This strategy thus paves a novel avenue to fabricate highly efficient organic/polymeric photocatalysts with precisely tunable operation windows and enhanced charge separation
Electronic correlations and energy gap in the bilayer nickelate LaNiO
The discovery of superconductivity with a critical temperature of 80~K in
LaNiO under pressure has received enormous attention.
LaNiO is not superconducting under ambient pressure but
exhibits a density-wave-like transition at ~K.
Understanding the electronic correlations, charge dynamics and dominant
orbitals are important steps towards the mechanism of superconductivity and
other instabilities. Here, our optical study shows that LaNiO
features strong electronic correlations which significantly reduce the
electron's kinetic energy and place it in the proximity of the Mott phase. The
low-frequency optical conductivity reveals two Drude components arising from
multiple bands dominated by the Ni- and Ni-
orbitals at the Fermi level. Above , the scattering rates for both
Drude components vary linearly with temperature, indicating non-Fermi-liquid
behavior which may be associated with spin-fluctuation scattering. Below
, a gap opens in the Ni- orbital, suggesting the
importance of the Ni- orbital in the density-wave-like
instability. Our experimental results provide key insights into the mechanism
of the density-wave-like order and superconductivity in
LaNiO.Comment: 26 pages, 4 figures, Comments are welcome and appreciate
Multiple tumor suppressors regulate a HIF-dependent negative feedback loop via ISGF3 in human clear cell renal cancer.
Whereas VHL inactivation is a primary event in clear cell renal cell carcinoma (ccRCC), the precise mechanism(s) of how this interacts with the secondary mutations in tumor suppressor genes, including PBRM1, KDM5C/JARID1C, SETD2, and/or BAP1, remains unclear. Gene expression analyses reveal that VHL, PBRM1, or KDM5C share a common regulation of interferon response expression signature. Loss of HIF2α, PBRM1, or KDM5C in VHL-/-cells reduces the expression of interferon stimulated gene factor 3 (ISGF3), a transcription factor that regulates the interferon signature. Moreover, loss of SETD2 or BAP1 also reduces the ISGF3 level. Finally, ISGF3 is strongly tumor-suppressive in a xenograft model as its loss significantly enhances tumor growth. Conversely, reactivation of ISGF3 retards tumor growth by PBRM1-deficient ccRCC cells. Thus after VHL inactivation, HIF induces ISGF3, which is reversed by the loss of secondary tumor suppressors, suggesting that this is a key negative feedback loop in ccRCC. © 2018, Liao et al
Investigation and epidemiological analysis of chronic diseases and comorbidities in hospitalized patients
Objective·To investigate the current situation and distribution characteristics of chronic comorbidities, and to provide reference for further improving the self-management of comorbidities and implementing the whole course and all-round management of comorbidity.Methods·Two thousand and forty-five inpatients in the Department of Geriatrics,Renji Hospital, Shanghai Jiao Tong University School of Medicine were enrolled in this study from December 2020 to February 2023. The general vital signs, routine laboratory examination and disease status were collected. The epidemiological distribution characteristics of chronic diseases and comorbidities were analyzed.Results·The incidence of chronic diseases in the surveyed population was 99.6%, and the incidence of comorbidities was 94.2%. The top 5 chronic diseases were hypertension (43.68%), diabetes mellitus (24.81%), malignant tumor (21.48%), hyperlipidemia (18.38%) and coronary heart disease (11.99%). The detection rates of hypertension, diabetes mellitus, coronary heart disease, chronic obstructive pulmonary disease, stoke and chronic kidney disease in males were significantly higher than those in females (P<0.05). The proportion of patients with 5 chronic diseases was the highest (11.99%), followed by 7 chronic diseases (10.26%) and 6 chronic diseases (10.04%). Among the patients of different ages, the comorbidity rate was the highest in the patients aged 50‒59 years (27.78%). In different age groups, patients aged 50 to 59 with 2 chronic diseases had the highest incidence of comorbidity, which was as high as 40.82%. Although the overall proportion of comorbidities among male patients (95.37%) was higher than that among females (93.77%), there was no statistically significant difference (P=0.125). However, the proportions of male patients with 2 and 5 chronic diseases were 70.41% and 60.63%, respectively, which were significantly higher than those of female patients (29.59% and 39.37%). The correlations between coronary heart disease and diabetes mellitus, hypertension and coronary heart disease, hypertension and diabetes mellitus were higher (r=0.24, r=0.27, r=0.35, all P<0.05).Conclusion·The prevalence of chronic diseases and comorbidities is high in the middle-aged and elderly population, and the number of comorbidities increases significantly with the increase of age
Surface skyrmions and dual topological Hall effect in antiferromagnetic topological insulator EuCdAs
In this work, we synthesized single crystal of EuCdAs, which exhibits
A-type antiferromagnetic (AFM) order with in-plane spin orientation below
= 9.5~K.Optical spectroscopy and transport measurements suggest its topological
insulator (TI) nature with an insulating gap around 0.1eV. Remarkably, a dual
topological Hall resistivity that exhibits same magnitude but opposite signs in
the positive to negative and negative to positive magnetic field hysteresis
branches emerges below 20~K. With magnetic force microscopy (MFM) images and
numerical simulations, we attribute the dual topological Hall effect to the
N\'{e}el-type skyrmions stabilized by the interactions between topological
surface states and magnetism, and the sign reversal in different hysteresis
branches indicates potential coexistence of skyrmions and antiskyrmions. Our
work uncovers a unique two-dimensional (2D) magnetism on the surface of
intrinsic AFM TI, providing a promising platform for novel topological quantum
states and AFM spintronic applications.Comment: 7 pages, 3 figure
High Thyroid Stimulating Hormone Level Is Associated With Hyperandrogenism in Euthyroid Polycystic Ovary Syndrome (PCOS) Women, Independent of Age, BMI, and Thyroid Autoimmunity: A Cross-Sectional Analysis
Background: Infertility and dyslipidemia are frequently present in both women with polycystic ovary syndrome (PCOS) and subjects with thyroid dysfunction. Limited study regarding the association between thyroid stimulating hormone (TSH) level and phenotypes in euthyroid PCOS women. We aimed to determine whether the variation of TSH level associates with phenotypes in euthyroid PCOS patients.Methods: Cross-sectional study including 600 PCOS and 200 age, body mass index (BMI), and thyroid autoimmunity-matched Chinese women from Renji hospital, Shanghai Jiaotong university during January 2010 and August 2018. The anthropometric and serum biochemical parameters related to TSH, thyroid autoimmunity, lipid profiles, and sex steroids were detected.Results: The TSH level is higher in (2.29 ± 1.24 vs. 1.86 ± 0.90 mu/L, p < 0.001) in PCOS than controls. In euthyroid PCOS patients, TSH, TG, TC, LDL-c, and apoB level increased from non-hyperandrogenism (nonHA) to HA group (all p < 0.05). TSH level is positively associated with TG, apoB, free T, FAI, and negatively associated with apoA (all p < 0.05). The percentage of HA increased from TSH level (57.93% in TSH < = 2.5 group vs. 69.46% in TSH > 2.5 mU/L group, p = 0.006). HA phenotype is increased with TSH level independently of age, BMI, WC, LDL-C. Besides, in multivariate logistic regression analysis TSH and TG significantly associated with HA phenotype.Conclusions: Higher TSH level is associated with increased prevalence of HA phenotype independent of age, BMI and thyroid autoimmunity in euthyroid PCOS
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Competing Interface and Bulk Effect-Driven Magnetoelectric Coupling in Vertically Aligned Nanocomposites.
Room-temperature magnetoelectric (ME) coupling is developed in artificial multilayers and nanocomposites composed of magnetostrictive and electrostrictive materials. While the coupling mechanisms and strengths in multilayers are widely studied, they are largely unexplored in vertically aligned nanocomposites (VANs), even though theory has predicted that VANs exhibit much larger ME coupling coefficients than multilayer structures. Here, strong transverse and longitudinal ME coupling in epitaxial BaTiO3:CoFe2O4 VANs measured by both optical second harmonic generation and piezoresponse force microscopy under magnetic fields is reported. Phase field simulations have shown that the ME coupling strength strongly depends on the vertical interfacial area which is ultimately controlled by pillar size. The ME coupling in VANs is determined by the competition between the vertical interface coupling effect and the bulk volume conservation effect. The revealed mechanisms shed light on the physical insights of vertical interface coupling in VANs in general, which can be applied to a variety of nanocomposites with different functionalities beyond the studied ME coupling effect.The work at Los Alamos National Laboratory was supported by the NNSA's Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy's NNSA, under contract 89233218CNA000001. Angular‐dependent magnetization studies (L.C.) were partially supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Sciences, and Engineering Division
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