57 research outputs found

    SEARCH FOR NATURALLY OCCURRING SUPERCONDUCTIVITY AND NOVEL PHENOMENA: MAGNETIC TRANSITIONS IN NATURAL TRANSITION METAL COMPOUNDS

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    Transition metal chalcogenides and transition metal arsenides are important families of natural mineral compounds widely distributed in the natural world. With similar structural and electronic properties of transition metal oxides, natural transition metal compounds are expected to have similar novel phenomena. With an ongoing project for searching natural superconductors in collaboration with Department of Mineral Science, Smithsonian National Museum of Natural History, we had a chance to investigate several natural minerals from the Smithsonian Museum in order to study previously unexpected naturally occurring mineral compounds for interesting ground states. We found several interesting magnetic transitions in these natural occurring mineral samples. Some of the magnetic transitions are not reported, some of the transitions are associated with other unreported novel quantum phenomena. In this thesis, I will discuss Bornite (Cu5FeS4), Berthierite (FeSb2S4), Nagyagite (Pb5Au(Te,Sb)4S58), Maucherite (Ni11As8) and related experiments in detail. Bornite (Cu5FeS4) has a semiconductor-insulator transition accompanied with an antiferromagnetic transition. As shown by our ability to tune the transition temperature and low-temperature metallicity by applying external pressure, Bornite may be a good candidate for Mott system and searching new superconductors. Berthierite (FeSb2S4) is a quasi-1-dimensional antiferromagnet. With strong anisotropic physical properties, berthierite may provide a very good system for understanding the low dimensional magnetic material. A Ferromagnetic order was found in natural Nagyagite (Pb5Au(Te,Sb)4S58) samples. The magnetic order, the weak anti-localization property with strong spin-orbital coupling and the 2-dimensional structure of this compound makes it a very interesting system for realizing topological properties in a natural compound. The magnetic order and transitions in both natural and synthetic Maucherite (Ni11As8) samples show interesting finite-size scale effect. It gives us a different approach to understand the differences in some physical properties between natural and synthetic compounds. Also, we will present a summary of other magnetic transitions and magnetic properties of more than 40 distinct minerals for this study and show the relation and similarities between strongly correlated transition metal oxide materials and other quantum materials. We will also make a list of other transition metal minerals that are worthy of investigation based on our research experience

    Incidence, risk factors and clinical outcomes of septic acute renal injury in cancer patients with sepsis admitted to the ICU: A retrospective study

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    BackgroundThe purpose of this study was to clarify the incidence, risk factors, and clinical outcomes of septic acute kidney injury (AKI) in cancer patients with sepsis admitted to the intensive care unit (ICU).MethodsA total of 356 cancer patients admitted to the ICU due to sepsis from January 2016 to October 2021 were analyzed retrospectively. According to the incidence of septic AKI, all patients were divided into the non-AKI group (n = 279) and the AKI group (n = 77). The clinical data after ICU admission were compared between the above two groups, and the risk factors and the clinical outcomes of septic AKI in the ICU were identified.ResultsThe incidence of septic AKI in all patients was 21.6% (77/356). LASSO regression and logistic regression all showed that lactate, sequential organ failure assessment (SOFA) score and septic shock were closely related to the occurrence of septic AKI. In terms of clinical outcomes after ICU admission, the rate of mechanical ventilation (MV) and continuous renal replacement therapy (CRRT), MV time, hospitalization time and 28-day mortality in the ICU were significantly higher in the septic AKI group than in the non-septic AKI group. Among the three subgroups of septic AKI (AKI combined with septic shock, septic cardiac dysfunction or acute respiratory failure), the mortality of patients in the subgroup of AKI combined with septic shock was significantly higher than others. CRRT has no significant effect on the short-term outcome of these patients.ConclusionLactate level, SOFA score and septic shock were closely related to the occurrence of septic AKI in the ICU. The clinical outcomes within 28 days after ICU admission of cancer patients with septic AKI were worse than those without septic AKI. The short-term outcome was worse in patients with septic AKI complicated with septic shock. CRRT does not have any significant effect on the short-term prognosis of cancer patients with septic AKI in the ICU

    Quantum-critical scale invariance in a transition metal alloy

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    Quantum-mechanical fluctuations between competing phases induce exotic collective excitations that exhibit anomalous behavior in transport and thermodynamic properties, and are often intimately linked to the appearance of unconventional Cooper pairing. High-temperature superconductivity, however, makes it difficult to assess the role of quantum-critical fluctuations in shaping anomalous finite-temperature physical properties. Here we report temperature-field scale invariance of non-Fermi liquid thermodynamic, transport, and Hall quantities in a non-superconducting iron-pnictide, Ba(Fe1/3Co1/3Ni1/3)2As2, indicative of quantum criticality at zero temperature and applied magnetic field. Beyond a linear-in-temperature resistivity, the hallmark signature of strong quasiparticle scattering, we find a scattering rate that obeys a universal scaling relation between temperature and applied magnetic fields down to the lowest energy scales. Together with the dominance of hole-like carriers close to the zero-temperature and zero-field limits, the scale invariance, isotropic field response, and lack of applied pressure sensitivity suggests a unique quantum critical system unhindered by a pairing instability

    An Overlap-Time Compensation Method for Current-Source Space-Vector PWM Inverters

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    Three‐dimensional morphological revealing of human placental villi with common obstetric complications via optical coherence tomography

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    Abstract Placental villi play a vital role in human fetal development, acting as the bridge of material exchange between the maternal and fetal. The abnormal morphology of placental villi is closely related to placental circulation disorder and pregnancy complications. Revealing placental villi three‐dimensional (3D) morphology of common obstetric complications and healthy pregnancies provides a new perspective for studying the role of the placenta and its villi in the development of pregnancy diseases. In this study, we established a noninvasive, high‐resolution 3D imaging platform via optical coherence tomography to reveal placental villi 3D morphological information of diseased and normal placentae. For the first time, 3D morphologies of placental villous tree structures in common obstetric complications were quantitatively revealed and corresponding 3D information could visualize the morphological characteristics of the placental villous tree from a more intuitive perspective, providing helpful information to the study of fetal development, feto‐maternal material exchange, and gestational complications treatment

    DataSheet_1_Diagnostic value of retinol-binding protein 4 in diabetic nephropathy: a systematic review and meta-analysis.pdf

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    ObjectiveDiabetic nephropathy (DN) is a major microvascular complication of diabetes and the leading cause of end-stage renal disease. Early detection and prevention of DN are important. Retinol-binding protein 4 (RBP4) has been considered as a single diagnostic marker for the detection of renal impairment. However, the results have been inconsistent. The present meta-analysis aimed to determine the diagnostic potential of RBP4 in patients in type 2 diabetes mellitus (T2DM) with DN.MethodsWe searched PubMed, Web of Science, Embase, Wanfang and CNKI databases from inception until January 2024. The meta-analysis was performed by Stata version 15.0, and sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR) and area under the curve (AUC) were pooled. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was utilized to assess the quality of each included study. In addition, heterogeneity and publication bias were evaluated.ResultsTwenty-nine studies were included in the meta-analysis. The pooled sensitivity and specificity were 0.76 [95% confidence interval (CI), 0.71–0.80] and 0.81 (95% CI, 0.76–0.85), respectively. The results showed a pooled PLR of 4.06 (95% CI, 3.16–5.21), NLR of 0.29 (95% CI, 0.24–0.36) and DOR of 13.76 (95% CI, 9.29–20.37). The area under the summarized receiver operating characteristic curve was given a value of 0.85 (95% CI, 0.82–0.88). No obvious publication bias existed in the Deeks’ funnel plot asymmetry test.ConclusionOur findings suggest that RBP4 has a promising diagnostic value with good sensitivity and specificity for patients with T2DM with DN.</p
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