63 research outputs found

    Electron correlations and superconductivity in La3_3Ni2_2O7_7 under pressure tuning

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    Motivated by the recent discovery of superconductivity in La3_3Ni2_2O7_7 under pressure, we discuss the basic ingredients of a model that captures its microscopic physics under pressure tuning. We anchor our description in terms of the spectroscopic evidence of strong correlations in this system. In a bilayer Hubbard model including the Ni 3d3d x2y2x^2-y^2 and z2z^2 orbitals, we show the ground state of the model crosses over from a low-spin S=1/2S=1/2 state to a high-spin S=3/2S=3/2 state. In the high-spin state, the two x2y2x^2-y^2 and the bonding z2z^2 orbitals are all close to half-filling, which promotes a strong orbital selectivity in a broad crossover regime of the phase diagram pertinent to the system. Based on these results, we construct an effective multiorbital tt-JJ model to describe the superconductivity of the system, and find the leading pairing channel to be an intraorbital spin singlet with a competition between the extended ss-wave and dx2y2d_{x^2-y^2} symmetries. Our results highlight the role of strong multiorbital correlation effects in driving the superconductivity of La3_3Ni2_2O7_7.Comment: 5.5+4 pages, 4+3 figures, 2 tables, updated version with supplemental materia

    Glutamic acid decarboxylase autoantibodies are dominant but insufficient to identify most Chinese with adult-onset non-insulin requiring autoimmune diabetes: LADA China study 5.

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    AIMS: Adult-onset autoimmune diabetes is prevalent in China, in contrast to childhood-onset type 1 diabetes mellitus. Islet autoantibodies are the most important immune biomarkers to diagnose autoimmune diabetes. We assayed four different islet autoantibodies in recently diagnosed adult non-insulin-requiring diabetes Chinese subjects to investigate the best antibody assay strategy for the correct diagnosis of these subjects. METHODS: LADA China study is a nation-wide multicenter study conducted in diabetes patients from 46 university-affiliated hospitals in China. Non-insulin-treated newly diagnosed adult diabetes patients (n = 2388) were centrally assayed for glutamic acid decarboxylase autoantibody (GADA), protein tyrosine phosphatase-2 autoantibody (IA-2A), and zinc transporter 8 autoantibody (ZnT8A) by radioligand assay and insulin autoantibody (IAA) by microtiter plate radioimmunoassay. Clinical data were determined locally. RESULTS: Two hundred and six (8.63 %) subjects were autoantibody positive, of which GADA identified 5.78 % (138/2388) of the total, but only 67 % (138/206) of the autoimmune cases. IA-2A, ZnT8A, and IAA were found in 1.51, 1.84, and 1.26 % of the total study subjects, respectively. When assaying three islet autoantibodies, the most effective strategy was the combination of GADA, ZnT8A, and IAA, which could identify 92.2 % (190/206) autoimmune diabetes patients. The clinical data showed that those subjects with positive GADA had lower random C-peptide than autoantibody negative subjects (P < 0.05). CONCLUSIONS: As with Europeans, GADA is the dominant autoantibody in this form of autoimmune diabetes in China, but in contrast to Europeans, screening should include other diabetes-associated autoantibodies

    Significant decrease of maternal mitochondria carryover using optimized spindle-chromosomal complex transfer.

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    Mutations in mitochondrial DNA (mtDNA) contribute to a variety of serious multi-organ human diseases, which are strictly inherited from the maternal germline. However, there is currently no curative treatment. Attention has been focused on preventing the transmission of mitochondrial diseases through mitochondrial replacement (MR) therapy, but levels of mutant mtDNA can often unexpectedly undergo significant changes known as mitochondrial genetic drift. Here, we proposed a novel strategy to perform spindle-chromosomal complex transfer (SCCT) with maximal residue removal (MRR) in metaphase II (MII) oocytes, thus hopefully eliminated the transmission of mtDNA diseases. With the MRR procedure, we initially investigated the proportions of mtDNA copy numbers in isolated karyoplasts to those of individual oocytes. Spindle-chromosomal morphology and copy number variation (CNV) analysis also confirmed the safety of this method. Then, we reconstructed oocytes by MRR-SCCT, which well developed to blastocysts with minimal mtDNA residue and normal chromosomal copy numbers. Meanwhile, we optimized the manipulation order between intracytoplasmic sperm injection (ICSI) and SCC transfer and concluded that ICSI-then-transfer was conducive to avoid premature activation of reconstructed oocytes in favor of normal fertilization. Offspring of mice generated by embryos transplantation in vivo and embryonic stem cells derivation further presented evidences for competitive development competence and stable mtDNA carryover without genetic drift. Importantly, we also successfully accomplished SCCT in human MII oocytes resulting in tiny mtDNA residue and excellent embryo development through MRR manipulation. Taken together, our preclinical mouse and human models of the MRR-SCCT strategy not only demonstrated efficient residue removal but also high compatibility with normal embryo development, thus could potentially be served as a feasible clinical treatment to prevent the transmission of inherited mtDNA diseases

    A proteogenomic signature of age-related macular degeneration in blood

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    © 2022. The Author(s). Funding Information: The authors acknowledge the contribution of the Icelandic Heart Association (IHA) staff to the AGES-RS, as well as the involvement of all study participants. We thank the IAMDGC consortium for supplying us with their GWAS summary statistics data. National Institute on Aging (NIA) contracts N01-AG-12100 and HHSN271201200022C for V.G. financed the AGES study; retinal image collection and AMD readings were funded by the NIH Intramural Research Program (ZIAEY000401). V.G. received a funding from the NIA (1R01AG065596), and IHA received a support from Althingi (the Icelandic Parliament). The Icelandic Research Fund (IRF) funded V.E. and Va.G. with grants 195761-051, 184845-053, and 206692-051, while Va.G. received a postdoctoral research grant from the University of Iceland Research Fund Funding Information: The study was supported by the Novartis Institute for Biomedical Research. M.T., N.F., S.P., X.L., R.E., Y.Z., S.J., C.L.H., S.M.L., J.L., C.L.G., A.A.N., B.L., R.P., Z.L., L.L.J., T.E.W., Q.Z., Q.H., and J.R.L. are employees and stockholders of Novartis. All other authors have no conflict of interests to declare. Publisher Copyright: © 2022, The Author(s).Age-related macular degeneration (AMD) is one of the most common causes of visual impairment in the elderly, with a complex and still poorly understood etiology. Whole-genome association studies have discovered 34 genomic regions associated with AMD. However, the genes and cognate proteins that mediate the risk, are largely unknown. In the current study, we integrate levels of 4782 human serum proteins with all genetic risk loci for AMD in a large population-based study of the elderly, revealing many proteins and pathways linked to the disease. Serum proteins are also found to reflect AMD severity independent of genetics and predict progression from early to advanced AMD after five years in this population. A two-sample Mendelian randomization study identifies several proteins that are causally related to the disease and are directionally consistent with the observational estimates. In this work, we present a robust and unique framework for elucidating the pathobiology of AMD.Peer reviewe

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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    Introduction. Switchingfrom polluting (e.g. wood, crop waste, coal)to clean (e.g. gas, electricity) cooking fuels can reduce household air pollution exposures and climate-forcing emissions.While studies have evaluated specific interventions and assessed fuel-switching in repeated cross-sectional surveys, the role of different multilevel factors in household fuel switching, outside of interventions and across diverse community settings, is not well understood. Methods.We examined longitudinal survey data from 24 172 households in 177 rural communities across nine countries within the Prospective Urban and Rural Epidemiology study.We assessed household-level primary cooking fuel switching during a median of 10 years offollow up (∼2005–2015).We used hierarchical logistic regression models to examine the relative importance of household, community, sub-national and national-level factors contributing to primary fuel switching. Results. One-half of study households(12 369)reported changing their primary cookingfuels between baseline andfollow up surveys. Of these, 61% (7582) switchedfrom polluting (wood, dung, agricultural waste, charcoal, coal, kerosene)to clean (gas, electricity)fuels, 26% (3109)switched between different polluting fuels, 10% (1164)switched from clean to polluting fuels and 3% (522)switched between different clean fuels

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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    Risk factors of fat necrosis in pectoralis major myocutaneous flaps

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    OBJECTIVE: To explore the risk factors of fat necrosis in pectoralis major myocutaneous flaps. METHODS: From May 1998 to December 2005, 82 patients underwent reconstruction of oral and maxillofacial defects with pectoralis major myocutaneous flaps in our hospital. Postoperative fat necrosis of the flaps was occurred in 10 cases. Logistic regression analysis was used to investigate the risk factors. RESULTS: (1) Logistic univariate regression analysis indicated that there was a significant correlation between fat necrosis of pectoralis major myocutaneous flap and the following risk facoars: obesity, subcutaneous tissues dissection performed by electrotome, the design of skin island beyond the seventh costal cartilage and smoking. (2) Logistic multivariate regression analysis suggested that there was a significant correlation between fat necrosis of pectoralis major myocutaneous flap and obesity, subcutaneous tissues dissection performed by electrotome, the design of skin island beyond the seventh costal cartilage, whereas there was no significant correlation between fat necrosis of flap and smoking. CONCLUSIONS: Obesity, subcutaneous tissues dissection performed by electrotome and the design of skin island beyond the seventh costal cartilage were the risk factors of fat necrosis in pectoralis major myocutaneous flap.link_to_subscribed_fulltex

    Deep reinforcement learning for UAV routing in the presence of multiple charging stations

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    Deploying Unmanned Aerial Vehicles (UAVs) for traffic monitoring has been a hotspot given their flexibility and broader view. However, a UAV is usually constrained by battery capacity due to limited payload. On the other hand, the development of wireless charging technology has allowed UAVs to replenish energy from charging stations.In this paper, we study a UAV routing problem in the presence of multiple charging stations (URPMCS) with the objective of minimizing the total distance traveled by the UAV during traffic monitoring. We present a deep reinforcement learning based method, where a multi-head heterogeneous attention mechanism is designed to facilitate learning a policy that automatically and sequentially constructs the route, while taking the energy consumption into account. In our method, two types of attentions are leveraged to learn the relations between monitoring targets and charging station nodes, adopting an encoder-decoder-like policy network. Moreover, we also employ a curriculum learning strategy to enhance generalization to different numbers of charging stations. Computational results show that our method outperforms conventional algorithms with higher solution quality (except for exact methods such as Gurobi) and shorter runtime in general, and also exhibits strong generalized performance on problem instances with different distributions and sizes.This work was supported in part by the National Natural Science Foundation of China under Grant 62073341 and in part by the Fundamental Research Funds for the Central Universities of Central South University under Grant 2022ZZTS0191
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