1,434 research outputs found

    Neutron and ARPES Constraints on the Couplings of the Multiorbital Hubbard Model for the Pnictides

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    The results of neutron scattering and angle-resolved photoemission experiments for the Fe-pnictide parent compounds, and their metallic nature, are shown to impose severe constraints on the range of values that can be considered "realistic" for the intraorbital Hubbard repulsion U and Hund coupling J in multiorbital Hubbard models treated in the mean-field approximation. Phase diagrams for three- and five-orbital models are here provided, and the physically realistic regime of couplings is highlighted, to guide future theoretical work into the proper region of parameters of Hubbard models. In addition, using the random phase approximation, the pairing tendencies in these realistic coupling regions are investigated. It is shown that the dominant spin-singlet pairing channels in these coupling regimes correspond to nodal superconductivity, with strong competition between several states that belong to different irreducible representations. This is compatible with experimental bulk measurements that have reported the existence of nodes in several Fe-pnictide compounds.Comment: 16 pages, 20 figure

    catena-Poly[[(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)(tricyano­methanido-κN)nickel(II)]-μ-tricyano­methanido]

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    In the title complex, [Ni(C4N3)2(C15H11N3)]n, each of the two different NiII atoms is coordinated by one 2,2′:6′2′′-terpyridine (terpy) and three tricyano­methanide ligands in a distorted octa­hedral geometry. The NiII atoms are linked to each other, forming an infinite chain parallel to (10). π–π Stacking inter­actions of terpy mol­ecules between adjacent chains (centroid–centroid distance = 3.785 Å), along with weak inter­molecular C—H⋯N hydrogen bonds involving the uncoordinated terminal N atoms of the tricyanomethanide ions and the terpyridine H atoms, result in the formation of a three-dimensional network structure

    Ferroptosis inhibitors: past, present and future

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    Ferroptosis is a non-apoptotic mode of programmed cell death characterized by iron dependence and lipid peroxidation. Since the ferroptosis was proposed, researchers have revealed the mechanisms of its formation and continue to explore effective inhibitors of ferroptosis in disease. Recent studies have shown a correlation between ferroptosis and the pathological mechanisms of neurodegenerative diseases, as well as diseases involving tissue or organ damage. Acting on ferroptosis-related targets may provide new strategies for the treatment of ferroptosis-mediated diseases. This article specifically describes the metabolic pathways of ferroptosis and summarizes the reported mechanisms of action of natural and synthetic small molecule inhibitors of ferroptosis and their efficacy in disease. The paper also describes ferroptosis treatments such as gene therapy, cell therapy, and nanotechnology, and summarises the challenges encountered in the clinical translation of ferroptosis inhibitors. Finally, the relationship between ferroptosis and other modes of cell death is discussed, hopefully paving the way for future drug design and discovery

    Immune Responses in Mice Immunized with Mastitis Multiple Vaccines Using Different Adjuvants

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    Background: Bovine mastitis, a serious disease associated with both high incidence and significant economic losses, posing a major challenge to the global dairy industry. The development of vaccines for protection from new infections by mastitis pathogens is of considerable interest to the milk production industry. Vaccination is a common and easy strategy for the control of infectious diseases, and the adjuvants used in the formulation is a critical factor for vaccine efficacy improvement. The main objective of the present study was to evaluate three different adjuvants for their ability to enhance immune responses of mice that vaccinated with Bovine Mastitis Multiple Vaccine.Materials, Methods & Results: The thymus and spleen index, the phagocytic ability of macrophage and the serum antibody levels of mice were detected after vaccination, respectively. The results showed that the thymus index, spleen index, and the phagocytic ability of macrophage of mice in Aluminum group exhibited a significant higher level (P < 0.05) compared with those in the control groups. The difference of the serum antibody levels was significant (P < 0.05) between experimental groups and control group after vaccination. The serum antibody concentration of mice in FIA group was higher compared with other groups and had a longer duration. The antibody concentration of mice in France 206 oil group can not increase as fast as the antibody concentration of Aluminum group, but it can last a longer time at a high level. In conclusion, multiple vaccines mixed with three different adjuvants could enhance the immunity of mice and Freund’s incomplete adjuvant is the best choice for this vaccine.Discussion: Adjuvants play an important role in increasing the efficacy of a number of different vaccines. In this study, three kinds of adjuvants (Aluminum hydroxide, France 206 oil and FIA) were evaluated for their adjuvant effects for multiple vaccine of bovine mastitis in mice and aluminum hydroxide did best as the vaccine adjuvant from the results. Aluminum hydroxide is a universally accepted adjuvant for both human and veterinary vaccines. The goal of vaccination is to generate strong immune response providing protection against infection for a time. Different protective effects will usually obtained by different adjuvants even use same antigen. In this work, FIA, Alum and 206 oil were chosen as adjuvants for inactivated antigens of Streptococcus agalactiae, Streptococcus dysgalactiae and Staphylococcus aureus. The results showed that there was a significantly higher antibody levels in vaccinated mice compared with those in control group. In addition, the mice in France 206 oil and FIA group performed a higher antibody levels and stronger immunity than mice in Aluminum hydroxide groups. These findings suggest that Freund’s incomplete adjuvant (FIA) would be the best candidate as the adjuvant for mastitis multiple vaccines investigated in this study

    Combined analysis of endometrial thickness and pattern in predicting outcome of in vitro fertilization and embryo transfer: a retrospective cohort study

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    <p>Abstract</p> <p>Objective</p> <p>To evaluate the combined effect of endometrial thickness and pattern on clinical outcome in patients undergoing in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET).</p> <p>Methods</p> <p>Cycles of IVF/ICSI-ET conducted between January 2003 and December 2008 at a university-based reproductive center were reviewed retrospectively. Endometrial ultrasonographic characteristics were recorded on the day of hCG administration. In the combined analysis, endometrial thickness groups (group 1: equal or <7 mm; group 2: 7-14 mm; group 3: >14 mm) were subdivided into two endometrial patterns (pattern A: triple-line; pattern B: no-triple line). Clinical pregnancy rate (CPR) and early miscarriage rate in different groups were analyzed.</p> <p>Results</p> <p>A total of 2896 cycles were reviewed. Clinical pregnancy rate (CPR) was 24.4% in group1-A. There were no second trimester pregnancies in group 1-B. Miscarriage rate in group 2-A was significantly lower compared to group 2-B (P < 0.01), although CPR did not show any significant differences between the groups. A no-triple line endometrial pattern with moderate endometrial thickness (7-14 mm) had a detrimental effect on pregnancy outcome, but not the occurrence of pregnancy. In group 3, there was no difference in CPR and miscarriage rates between the two patterns; adequate endometrial thickness (>14 mm) seemed to mitigate the detrimental impact (high miscarriage rate) of pattern B.</p> <p>Conclusion</p> <p>Combined analysis of endometrial thickness and pattern on the day of hCG administration was a better predictor of the outcome of IVF/ICSI-ET and may be more helpful for patient counseling than the separate analyses.</p

    Bis(2,2′-bipyridyl dioxide-κ2 N,N′)bis­(tricyano­methanido)cobalt(II) dihydrate

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    In the title compound, [Co(C4N3)2(C10H8N2O2)]·2H2O, a novel tricyano­methanide complex, the CoII atom is located on an inversion center and has a distorted octa­hedral coordination with two 2,2′-bipyridyl dioxide (dpdo) mol­ecules and two trans tricyano­methanide (tcm) anions. The equatorial plane is formed by the four O atoms of the two chelating dpdo ligands, with one N atom of each of the two tcm ligands occupying an apical position. There is a disordered solvent water mol­ecule in the asymmetric unit (occupancy ratio 0.63:0.37). These water mol­ecules result in the formation of O—H⋯O and O—H⋯N hydrogen bonds, building a layer parallel to (100). The layers are linked by C—H⋯N hydrogen-bonding inter­actions, leading to a three-dimensional network

    A risk prediction model for type 2 diabetes mellitus complicated with retinopathy based on machine learning and its application in health management

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    ObjectiveThis study aimed to establish a risk prediction model for diabetic retinopathy (DR) in the Chinese type 2 diabetes mellitus (T2DM) population using few inspection indicators and to propose suggestions for chronic disease management.MethodsThis multi-centered retrospective cross-sectional study was conducted among 2,385 patients with T2DM. The predictors of the training set were, respectively, screened by extreme gradient boosting (XGBoost), a random forest recursive feature elimination (RF-RFE) algorithm, a backpropagation neural network (BPNN), and a least absolute shrinkage selection operator (LASSO) model. Model I, a prediction model, was established through multivariable logistic regression analysis based on the predictors repeated ≥3 times in the four screening methods. Logistic regression Model II built on the predictive factors in the previously released DR risk study was introduced into our current study to evaluate the model’s effectiveness. Nine evaluation indicators were used to compare the performance of the two prediction models, including the area under the receiver operating characteristic curve (AUROC), accuracy, precision, recall, F1 score, balanced accuracy, calibration curve, Hosmer-Lemeshow test, and Net Reclassification Index (NRI).ResultsWhen including predictors, such as glycosylated hemoglobin A1c, disease course, postprandial blood glucose, age, systolic blood pressure, and albumin/urine creatinine ratio, multivariable logistic regression Model I demonstrated a better prediction ability than Model II. Model I revealed the highest AUROC (0.703), accuracy (0.796), precision (0.571), recall (0.035), F1 score (0.066), Hosmer-Lemeshow test (0.887), NRI (0.004), and balanced accuracy (0.514).ConclusionWe have built an accurate DR risk prediction model with fewer indicators for patients with T2DM. It can be used to predict the individualized risk of DR in China effectively. In addition, the model can provide powerful auxiliary technical support for the clinical and health management of patients with diabetes comorbidities

    Angiopoietin-2 impairs collateral artery growth associated with the suppression of the infiltration of macrophages in mouse hindlimb ischaemia

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    Abstract Background Angiopoietin-2 (Ang-2), a ligand of the Tie-2 receptor, plays an important role in maintaining endothelial cells and in destabilizing blood vessels. Collateral artery growth (arteriogenesis) is a key adaptive response to arterial occlusion. It is unknown whether the destabilization of blood vessels by Ang-2 can affect arteriogenesis and modulate mononuclear cell function. This study aimed to investigate the effects of Ang-2 on collateral artery growth. Methods Hindlimb ischaemia model was produced in C57BL/6 mice by femoral artery ligation. Blood flow perfusion was measured using a laser Doppler perfusion imager quantitative RT-PCR analysis was applied to identify the level of angiogenic factors. Results After the induction of hindlimb ischaemia, blood flow recovery was impaired in mice treated with recombinant Ang-2 protein; this was accompanied by a reduction of peri-collateral macrophage infiltration. In addition, quantitative RT-PCR analysis revealed that Ang-2 treatment decreased monocyte chemotactic protein-1 (MCP-1), platelet-derived growth factor-BB (PDGF-BB) mRNA levels in ischaemic adductor muscles. Ang-2 can lead to macrophage M1/M2 polarization shift inhibition in the ischaemic muscles. Furthermore, Ang-2 reduced the in vitro inflammatory response in macrophages and vascular cells involved in arteriogenesis. Conclusions Our results demonstrate that Ang-2 is essential for efficient arteriogenesis, which controls macrophage infiltration

    Skp2 expression unfavorably impacts survival in resectable esophageal squamous cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>The correlation of S-phase kinase–associated protein 2 (Skp2) with metastasis and prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. The purpose of this study was to explore whether there was a correlation between the expression of Skp2 evaluated by immunohistochemistry and the clinical outcome of patients with operable ESCC, and to further determine the possible mechanism of the impact of Skp2 on survival.</p> <p>Methods</p> <p>Tissue microarrays that included 157 surgically resected ESCC specimens was successfully generated for immunohistochemical evaluation. The clinical/prognostic significance of Skp2 expression was analyzed. Kaplan-Meier analysis was used to compare the postoperative survival between groups. The prognostic impact of clinicopathologic variables and Skp2 expression was evaluated using a Cox proportional hazards model. A cell proliferation assay and a colony formation assay were performed in ESCC cell lines to determine the function of Skp2 on the progression of ESCC <it>in vitro</it>.</p> <p>Results</p> <p>Skp2 expression correlated closely with the T category (<it>p</it> = 0.035) and the pathological tumor-node-metastasis (TNM) stage (<it>p</it> = 0.027). High expression of Skp2 was associated with poor overall survival in resectable ESCC (<it>p</it> = 0.01). The multivariate Cox regression analysis demonstrated that pathological T category, pathological N category, cell differentiation, and negative Skp2 expression were independent factors for better overall survival. <it>In vitro</it> assays of ESCC cell lines demonstrated that Skp2 promoted the proliferative and colony-forming capacity of ESCCs.</p> <p>Conclusions</p> <p>Negative Skp2 expression in primary resected ESCC is an independent factor for better survival. Skp2 may play a pro-proliferative role in ESCC cells.</p
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