115 research outputs found

    One-Dimensional Hydrogen-Bonded Infinite Chain from Nickel(II) Tetraaza Macrocyclic Complex and 1,2-Cyclopentanedicarboxylate Ligand

    Get PDF
    The reaction of [Ni(L)]Cl2·2H2O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,01.18,07.12]docosane) with trans-1,2-cyclopentanedicarboxylic acid (H2-cpdc) yields a 1D hydrogen-bonded infinite chain with formula [Ni(L)(H-cpdc−)2] (1). This complex has been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry about Ni atom with four nitrogen atoms of the macrocycle and two oxygen atoms of the H-cpdc− ligand at the axial position. Compound 1 crystallizes in the monoclinic system P21/c with a = 8.7429(17), b = 10.488(2), c = 18.929(4) Å, β = 91.82(2), V = 1734.8(6) Å3, Z = 2. Electronic spectrum of 1 reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to NiII/NiIII and NiII/NiI processes

    Edge-carboxylated graphene nanoplatelets as oxygen-rich metal-free cathodes for organic dye-sensitized solar cells

    Get PDF
    Edge-carboxylated graphene nanoplatelets (ECGnPs) were synthesized by the simple, efficient and eco-friendly ball-milling of graphite in the presence of dry ice and used as oxygen-rich metal-free counter electrodes (CEs) in organic dye-sensitized solar cells (DSSCs), for the first time. The resultant ECGnPs are soluble in many polar solvents including 2-propanol due to the polar nature of numerous carboxylic acids at edges, allowing an electrostatic spray (e-spray) to be deposited on fluorine-doped SnO2 (FTO)/glass substrates. The ECGnP-CE exhibited profound improvements in the electrochemical stability for the Co(bpy)3 2+/3+ redox couple compared to the platinum (Pt)-CE. The charge transfer resistance (RCT), related to the interface between an electrolyte and a CE, was significantly reduced to 0.87 ?? cm2, much lower than those of (Pt)-CE (2.19 ?? cm 2), PEDOT:PSS-CE (2.63 ?? cm2) and reduced graphene oxide (rGO)-CE (1.21 ?? cm2). The DSSC based on the JK-303-sensitizer and ECGnP-CE displayed a higher photovoltaic performance (FF, Jsc, and ??, 74.4%, 14.07 mA cm-2 and 9.31%) than those with the Pt-CE (71.6%, 13.69 mA cm-2 and 8.67%), PEDOT:PSS (68.7%, 13.68 mA cm-2 and 8.25%) and rGO-CE (72.9%, 13.88 mA cm-2 and 8.94%).close3

    Induced neural stem cells from distinct genetic backgrounds exhibit different reprogramming status

    Get PDF
    Somatic cells could be directly converted into induced neural stem cells (iNSCs) by ectopic expression of defined transcription factors. However, the underlying mechanism of direct lineage transition into iNSCs is largely unknown. In this study, we examined the effect of genetic background on the direct conversion process into an iNSC state. The iNSCs from two different mouse strains exhibited the distinct efficiency of lineage conversion as well as clonal expansion. Furthermore, the expression levels of endogenous NSC markers, silencing of transgenes, and in vitro differentiation potential were also different between iNSC lines from different strains. Therefore, our data suggest that the genetic background of starting cells influences the conversion efficiency as well as reprogramming status of directly converted iNSCs.ope

    Ovarian Cancer during Pregnancy: Clinical and Pregnancy Outcome

    Get PDF
    The aim of this study is to evaluate the clinical feature and pregnancy outcome in patients with ovarian cancer diagnosed during pregnancy. We retrospectively analyzed the medical records of 27 patients diagnosed with ovarian cancer during pregnancy at Cheil General Hospital & Women's Healthcare Center from January 1996 to December 2006. Mean age of the patients was 29.1 yr (range 23-40), and a mean follow-up period was 57 months (range 7-112 months). Of 27 patients, 15 (55.5%) had borderline malignancies, 7 (25.9%) had epithelial malignancies and 5 (18.6%) had germ cell tumors. A total of 26 patients received a conservative surgery preserving pregnancy. The mean time for surgical intervention during pregnancy was 20 weeks of gestational age. Of the 27 patients, 26 had full term delivery of a healthy baby without any congenital malformation. Only one patient with epithelial ovarian cancer had a relapse at 19 months after the first conservative operation with adjuvant chemotherapy. There were few data for managing patients with ovarian cancer diagnosed during pregnancy. This study results could help establish a guideline for management of ovarian malignancy complicating pregnancy

    Clinical Outcomes of Patients treated for Cervical Pregnancy with or without Methotrexate

    Get PDF
    The objective of this study is to describe the clinical outcomes of patients treated for cervical pregnancy with or without methotrexate (MTX) and to evaluate the effects of MTX in the treatment of cervical pregnancy. Between January 1993 and February 2000, 31 patients were diagnosed with cervical pregnancy. Twenty-two patients were treated with MTX chemotherapy and nine patients were treated with surgical procedures without MTX treatment. In the non-MTX treatment group, three patients underwent total abdominal hysterectomy, five required adjuvant procedures to control the bleeding during dilatation and curettage (D&C) and only one patient was treated with a simple D&C. In the MTX treatment group, fourteen (63.6%) patients were treated with only MTX and eight (36.4%) cases underwent concomitant procedures (simple curettage, curettage and Foley catheter tamponade, cervical cerclage, ligation of the descending branches of uterine arteries, or ligation of hypogastric arteries). The uterus was preserved in all cases and three women delivered healthy babies in their subsequent pregnancy. In conclusion, early diagnosis, appropriate MTX regimen in combination of necessary adjuvant conservative procedures could contribute to successful treatment with preservation of the uterus and future reproductive ability

    A Prediction Rule to Identify Severe Cases among Adult Patients Hospitalized with Pandemic Influenza A (H1N1) 2009

    Get PDF
    The purpose of this study was to establish a prediction rule for severe illness in adult patients hospitalized with pandemic influenza A (H1N1) 2009. At the time of initial presentation, the baseline characteristics of those with severe illness (i.e., admission to intensive care unit, mechanical ventilation, or death) were compared to those of patients with non-severe illnesses. A total of 709 adults hospitalized with pandemic influenza A (H1N1) 2009 were included: 75 severe and 634 non-severe cases. The multivariate analysis demonstrated that altered mental status, hypoxia (PaO2/FiO2 ≤ 250), bilateral lung infiltration, and old age (≥ 65 yr) were independent risk factors for severe cases (all P < 0.001). The area under the ROC curve (0.834 [95% CI, 0.778-0.890]) of the number of risk factors were not significantly different with that of APACHE II score (0.840 [95% CI, 0.790-0.891]) (P = 0.496). The presence of ≥ 2 risk factors had a higher sensitivity, specificity, positive predictive value and negative predictive value than an APACHE II score of ≥ 13. As a prediction rule, the presence of ≥ 2 these risk factors is a powerful and easy-to-use predictor of the severity in adult patients hospitalized with pandemic influenza A (H1N1) 2009

    Laboratory information management system for COVID-19 non-clinical efficacy trial data

    Get PDF
    Background : As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results : In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions : This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.This research was supported by the National research foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2020M3A9I2109027 and 2021M3H9A1030260)

    Self-Assembly of a 1D Hydrogen-Bonded Polymer from a Hexamethyltetraaza Macrocyclic Nickel(II) Complex and Isophthalic Acid

    No full text
    The compound [Ni(L)(isoph)2][Ni(L)]·8H2O (1; L = C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane; H2-isoph = isophthalic acid) has been synthesized and structurally characterized. Complex 1 exhibits a geometrically symmetric core with a {4/6} coordination number set. The coordination environment around the Ni(1) ion is a distorted octahedron, while the geometry around the four-coordinate Ni(2) is depicted as square planar in 1D hydrogen-bonded infinite chain. The compound crystallizes in the triclinic system P-1 with a = 8.602(2), b = 10.684(7), c = 16.550(3) Å, a = 91.04(4), b = 94.09(2), g = 111.09(4)°, V = 1413.9(10) Å3, Z = 1. The cyclic voltammogram of 1 undergoes one-electron wave corresponding to NiII/NiI process. The electronic spectra, electrochemical and TGA behavior of the complex are significantly affected by the nature of the hexamethyltetraaza macrocycle and the axial isoph2− ligand

    Context-Adaptable Trigger: A New IS Paradigm and Challenge

    No full text
    1
    corecore