47 research outputs found
Self doping effect and successive magnetic transitions in superconducting SrVFeAsO
We have studied a quinary Fe-based superconductor SrVFeAsO by the
measurements of x-ray diffraction, x-ray absorption, M\"{o}ssbauer spectrum,
resistivity, magnetization and specific heat. This apparently undoped
oxyarsenide is shown to be self doped via electron transfer from the V
ions. We observed successive magnetic transitions within the VO layers: an
antiferromagnetic transition at 150 K followed by a weak ferromagnetic
transition at 55 K. The spin orderings within the VO planes are discussed
based on mixed valence of V and V.Comment: One Table and more references are adde
Exploration of Programmed Cell Death-Associated Characteristics and Immune infiltration in Neonatal Sepsis: New insights From Bioinformatics analysis and Machine Learning
BACKGROUND: Neonatal sepsis, a perilous medical situation, is typified by the malfunction of organs and serves as the primary reason for neonatal mortality. Nevertheless, the mechanisms underlying newborn sepsis remain ambiguous. Programmed cell death (PCD) has a connection with numerous infectious illnesses and holds a significant function in newborn sepsis, potentially serving as a marker for diagnosing the condition.
METHODS: From the GEO public repository, we selected two groups, which we referred to as the training and validation sets, for our analysis of neonatal sepsis. We obtained PCD-related genes from 12 different patterns, including databases and published literature. We first obtained differential expressed genes (DEGs) for neonatal sepsis and controls. Three advanced machine learning techniques, namely LASSO, SVM-RFE, and RF, were employed to identify potential genes connected to PCD. to further validate the results, PPI networks were constructed, artificial neural networks and consensus clustering were used. Subsequently, a neonatal sepsis diagnostic prediction model was developed and evaluated. We conducted an analysis of immune cell infiltration to examine immune cell dysregulation in neonatal sepsis, and we established a ceRNA network based on the identified marker genes.
RESULTS: Within the context of neonatal sepsis, a total of 49 genes exhibited an intersection between the differentially expressed genes (DEGs) and those associated with programmed cell death (PCD). Utilizing three distinct machine learning techniques, six genes were identified as common to both DEGs and PCD-associated genes. A diagnostic model was subsequently constructed by integrating differential expression profiles, and subsequently validated by conducting artificial neural networks and consensus clustering. Receiver operating characteristic (ROC) curves were employed to assess the diagnostic merit of the model, which yielded promising results. The immune infiltration analysis revealed notable disparities in patients diagnosed with neonatal sepsis. Furthermore, based on the identified marker genes, the ceRNA network revealed an intricate regulatory interplay.
CONCLUSION: In our investigation, we methodically identified six marker genes (AP3B2, STAT3, TSPO, S100A9, GNS, and CX3CR1). An effective diagnostic prediction model emerged from an exhaustive analysis within the training group (AUC 0.930, 95%CI 0.887-0.965) and the validation group (AUC 0.977, 95%CI 0.935-1.000)
Fluid mineralization of the Dongtongyu gold deposit in the southern margin of North China craton: Evidence from microthermometry and composition of fluid inclusions
In this study, petrographic, microthermometric, and synchrotron radiation X-ray fluorescence (SRXRF) analyses of fluid inclusions were conducted to shed light on the mineralization mechanism of the Dongtongyu deposit and provide some evidence of the relationship among CO2, Au, and other ore elements (e.g., Cu, Fe, Zn, and Pb) in ore-forming fluids. The ore-forming fluid is characterized as the H2O–CO2–NaCl system with medium–high temperatures and low salinities. Four structural mineralization stages are distinguished: Pyrite-quartz (Stage 1), gold-quartz-pyrite (Stage 2), gold-quartz-polymetallic sulfide (Stage 3), and quartz-calcite (Stage 4). Fluid inclusions in Stages 1–3 are dominated by the H2O–CO2 type, and most of them contain liquid H2O and liquid CO2 at room temperature. The melting temperatures (Tm-CO2 = −82.1°C to −57.5°C) of solid CO2 in Stage 1 are relatively low. The values of Tm-CO2 in Stages 2–3 are quite close, with ranges of −60.5°C to −56.5°C and −59.2°C to −58.6°C, respectively. The melting temperatures of clathrate in Stages 1–3 are −2.7°C to +7.8°C, −5.5°C to +7.8°C, and +3.7°C to +7.2°C. The homogenization temperatures of the CO2 phase in the H2O–CO2 inclusions of the three stages are measured as −7.5°C to +31.7°C, −7.5°C to +29.3°C, and 7.1°C to +24.1°C. The total homogenization temperatures in Stages 1–3 are 180°C–394°C, 202°C–305°C, and 224°C–271°C, with salinities of 4.3 wt.%–18.2 wt% NaCl, 4.3 wt.%–20.0 wt% NaCl, and 5.3 wt.%–11.0 wt% NaCl, respectively. The laser Raman spectroscopy results show that the CO2–H2O inclusions in the quartz veins contain abundant CO2 and CH4. The SRXFR results show that most of the elements, especially As, Te, and Cu, are more enriched in liquid CO2 than in liquid H2O. The elements of Au, Fe, Ni, Cu, and Pb have higher concentrations in H2O–CO2-type fluid inclusions in Stage 2 than other fluid inclusions in Stages 1–2, suggesting that gold mineralization is closely related to CO2-rich fluids. During the fluid evolution process, fluid immiscibility is an important mineralization mechanism of gold. The increase in CO2 and CH4 and the decrease in the fluid temperature might promote fluid immiscibility
Peripheral blood CD19 positive B lymphocytes increase after ischemic stroke and correlate with carotid atherosclerosis
IntroductionAtherosclerosis is the primary pathological basis of ischemic stroke, and dyslipidemia is one of its major etiological factors. Acute ischemic stroke patients exhibit imbalances in lymphocyte subpopulations, yet the correlation between these dynamic changes in lymphocyte subpopulations and lipid metabolism disorders, as well as carotid atherosclerosis in stroke patients remains poorly understood.MethodsWe retrospectively analyzed the demographic data, risk factors of cerebrovascular disease, laboratory examination (lymphocyte subsets, lipid indexes, etc.), clinical features and c;/]-sity from December 2017 to September 2019 and non-stroke patients with dizziness/vertigo during the same period.ResultsThe results showed that peripheral B lymphocyte proportions are elevated in acute ischemic stroke patients compared with those of the control group (13.6 ± 5.3 vs. 11.7 ± 4.4%, p = 0.006). Higher B lymphocyte proportions are associated with concurrent dyslipidemia, increased levels of vascular risk factors including triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C), as well as decreased levels of the protective factor high-density lipoprotein cholesterol (HDL-C). Elevated B lymphocyte proportions are independently correlated with carotid atherosclerosis in stroke patients.DiscussionWe found CD19 positive B Lymphocytes increase after ischemic stroke and correlate with Carotid Atherosclerosis. Lymphocyte subpopulations should be highlighted in stroke patients
Age of Gold Mineralizations of Dongping and Xiaoyingpan Gold Deposits in North China Craton: Constraints from the Zircon U–Pb Dating and Fission-Track Analysis
Northwest Hebei province is one of the gold-producing areas in China. Based on a geochronological analysis of the Zhangjiakou-Xuanhua area, zircon U–Pb with an age of 2487–142 Ma and zircon fission-track (ZFT) with a cooling age of 155–66 Ma were obtained. Zircon U–Pb dating of the Xiaoyingpan deposit revealed two ages of 2487 ± 92 Ma and 1745 ± 89 Ma, representing the Archaean and Early Proterozoic metamorphism of the Sanggan Group. The ZFT cooling age of 155 ± 10 Ma represents the deposit’s lower limit metallogenic age. The Shuiquangou (SQG) alkaline complex emplaced at 388.9 ± 3.0 Ma and experienced magmatic activities until the Late Devonian (ca 377 Ma), considering the response to the collision between the Siberian plate and the North China Craton. The emplacement age of Shangshuiquan (SSQ) granite is 142.3 ± 1.1 Ma and is coeval with the thinning of the North China Craton during the Late Jurassic–Early Cretaceous. The intrusion of SSQ might partially reheat the SQG complex, resulting in the Yanshanian gold mineralization in Dongping. The SQG complex and SSQ granite underwent a relatively consistent rapid cooling process in the Cretaceous based on the ZFT ages
Hierarchical identity-based chameleon hash and its applications
Abstract. At ACNS 2008, Canard et al. introduced the notion of trap-door sanitizable signature (TSS) based on identity-based chameleon hash (IBCH). Trapdoor sanitizable signatures allow the signer of a message to delegate, at any time, the power of sanitization to possibly several entities who can modify predetermined parts of the message and gener-ate a new signature on the sanitized message without interacting with the original signer. In this paper, we introduce the notion of hierarchical identity-based chameleon hash (HIBCH), which is a hierarchical exten-sion of IBCH. We show that HIBCH can be used to construct other cryptographic primitives, including hierarchical trapdoor sanitizable sig-nature (HTSS) and key-exposure free IBCH. HTSS allows an entity who has the sanitization power for a given signed message, to further delegate its power to its descendants in a controlled manner. Finally, we propose a concrete construction of HIBCH and show that it is t-threshold collusion-resistant
Catalytic Oxidative/Extractive Desulfurization of Model Oil using Transition Metal Substituted Phosphomolybdates-Based Ionic Liquids
Polyoxometalates based ionic liquids (POM-ILs) exhibit a high catalytic activity in oxidative desulfurization. In this paper, four new POM-IL hybrids based on transition metal mono-substituted Keggin-type phosphomolybdates, [Bmim]5[PMo11M(H2O)O39] (Bmim = 1-butyl 3-methyl imidazolium; M = Co2+, Ni2+, Zn2+, and Mn2+), have been synthesized and used as catalysts for the oxidation/extractive desulfurization of model oil, in which ILs are used as the extraction solvent and H2O2 as an oxidant under very mild conditions. The factors that affected the desulfurization efficiency were studied and the optimal reaction conditions were obtained. The results showed that the [Bmim]5[PMo11Co(H2O)O39] catalyst demonstrated the best catalytic activity, with sulfur-removal of 99.8%, 85%, and 63% for dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT), respectively, in the case of extraction combining with a oxidative desulfurization system under optimal reaction conditions (5 mL model oil (S content 500 ppm), n(catalyst) = 4 μmol, n(H2O2)/n(Substrate) = 5, T = 50 °C for 60 min with [Omim]BF4 (1 mL) as the extractant). The catalyst can be recycled at least 8 times, and still has stability and high catalytic activity for consecutive desulfurization. Probable reaction mechanisms have been proposed for catalytic oxidative/extractive desulfurization
Fabrication of a Cell Fixation Device for Robotic Cell Microinjection
Automation of cell microinjection greatly reduces operational difficulty, but cell fixation remains a challenge. Here, we describe an innovative device that solves the fixation problem without single-cell operation. The microarray cylinder is designed with a polydimethylsiloxane (PDMS) material surface to control the contact force between cells and the material. Data show that when the injection velocity exceeds 1.5 mm/s, microinjection success rate is over 80%. The maximum value of the adhesion force between the PDMS plate and the cell is 0.0138 N, and the need can be met in practical use of the robotic microinjection