79 research outputs found

    Preparation of nanostructured TiO2 photoelectrode for flexible dye-sensitized solar cell applications

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    Nanocrystalline titanium dioxide (TiO2) thin film was successfully prepared by simple electrodeposition method from alkaline aqueous solution containing potassium titanium oxalate and hydroxylamine. Surface characterization of the electrodeposited films indicates the formation of crystalline TiO2. The dye solar cell constructed from dye-modified electrodeposited TiO2 film achieved an overall light-to-electricity conversion efficiency of 2.1 % under 1 sun illumination, indicating its high potential as a photoelectrode material for the DSCs

    Novel, Objective, Multivariate Biomarkers Composed of Plasma Amino Acid Profiles for the Diagnosis and Assessment of Inflammatory Bowel Disease

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    BACKGROUND: Inflammatory bowel disease (IBD) is a chronic intestinal disorder that is associated with a limited number of clinical biomarkers. In order to facilitate the diagnosis of IBD and assess its disease activity, we investigated the potential of novel multivariate indexes using statistical modeling of plasma amino acid concentrations (aminogram). METHODOLOGY AND PRINCIPAL FINDINGS: We measured fasting plasma aminograms in 387 IBD patients (Crohn's disease (CD), nβ€Š=β€Š165; ulcerative colitis (UC), nβ€Š=β€Š222) and 210 healthy controls. Based on Fisher linear classifiers, multivariate indexes were developed from the aminogram in discovery samples (CD, nβ€Š=β€Š102; UC, nβ€Š=β€Š102; age and sex-matched healthy controls, nβ€Š=β€Š102) and internally validated. The indexes were used to discriminate between CD or UC patients and healthy controls, as well as between patients with active disease and those in remission. We assessed index performances using the area under the curve of the receiver operating characteristic (ROC AUC). We observed significant alterations to the plasma aminogram, including histidine and tryptophan. The multivariate indexes established from plasma aminograms were able to distinguish CD or UC patients from healthy controls with ROC AUCs of 0.940 (95% confidence interval (CI): 0.898-0.983) and 0.894 (95%CI: 0.853-0.935), respectively in validation samples (CD, nβ€Š=β€Š63; UC, nβ€Š=β€Š120; healthy controls, nβ€Š=β€Š108). In addition, other indexes appeared to be a measure of disease activity. These indexes distinguished active CD or UC patients from each remission patients with ROC AUCs of 0.894 (95%CI: 0.853-0.935) and 0.849 (95%CI: 0.770-0.928), and correlated with clinical disease activity indexes for CD (r(s)β€Š=β€Š0.592, 95%CI: 0.385-0.742, p<0.001) or UC (r(s)β€Š=β€Š0.598, 95%CI: 0.452-0.713, p<0.001), respectively. CONCLUSIONS AND SIGNIFICANCE: In this study, we demonstrated that established multivariate indexes composed of plasma amino acid profiles can serve as novel, non-invasive, objective biomarkers for the diagnosis and monitoring of IBD, providing us with new insights into the pathophysiology of the disease

    Intersubject and intrasubject variability of potential plasma and urine metabolite and protein biomarkers in healthy human volunteers

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    A limited understanding of intersubject and intrasubject variability hampers effective biomarker translation from in vitro/in vivo studies to clinical trials and clinical decision support. Specifically, variability of biomolecule concentration can play an important role in interpretation, power analysis, and sampling time designation. In the present study, a wide range of 749 plasma metabolites, 62 urine biogenic amines, and 1,263 plasma proteins were analyzed in 10 healthy male volunteers measured repeatedly during 12 hours under tightly controlled conditions. Three variability components in relative concentration data are determined using linear mixed models: between (intersubject), time (intrasubject), and noise (intrasubject). Biomolecules such as 3-carboxy-4-methyl-5-propyl-2-furanpropanoate, platelet-derived growth factor C, and cathepsin D with low noise potentially detect changing conditions within a person. If also the between component is low, biomolecules can easier differentiate conditions between persons, for example cathepsin D, CD27 antigen, and prolylglycine. Variability over time does not necessarily inhibit translatability, but requires choosing sampling times carefully.Analytical BioScience

    Preoperative induction chemotherapy with cisplatin and irinotecan for pathological N2 non-small cell lung cancer

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    We conducted a phase I/II study to investigate whether the surgical resection after induction chemotherapy with cisplatin and irinotecan was feasible and could improve the treatment outcome for patients with pathological N2 non-small cell lung cancer. Fifteen patients with stage IIIA non-small cell lung cancer having mediastinal lymph node metastases proved by mediastinoscopy were eligible. Both cisplatin (60 mg mβˆ’2) and irinotecan (50 mg mβˆ’2) were given on days 1 and 8. Patients received two cycles of chemotherapy after 3–4 weeks interval. Induction was followed by surgical resection in 4–6 weeks. Patients who had documented tumour regression after preoperative chemotherapy received two additional cycles of chemotherapy and other patients received radiotherapy postoperatively. After the induction chemotherapy, the objective response rate was 73%. All the 15 patients received surgical resection and complete resection was achieved in 11 (73%) patients. There was no operation-related death and one death due to radiation pneumonitis during postoperative radiotherapy. The median time from entry to final analysis was 46.5 months, ranging from 22 to 68 months. The 5-year survival rate was 40% for all the 15 patients and it was 55% for the 11 patients who underwent complete resection. We conclude that the surgical resection after induction chemotherapy with cisplatin and irinotecan is feasible, and associated with low morbidity and high respectability

    Histamine Derived from Probiotic Lactobacillus reuteri Suppresses TNF via Modulation of PKA and ERK Signaling

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    Beneficial microbes and probiotic species, such as Lactobacillus reuteri, produce biologically active compounds that can modulate host mucosal immunity. Previously, immunomodulatory factors secreted by L. reuteri ATCC PTA 6475 were unknown. A combined metabolomics and bacterial genetics strategy was utilized to identify small compound(s) produced by L. reuteri that were TNF-inhibitory. Hydrophilic interaction liquid chromatography-high performance liquid chromatography (HILIC-HPLC) separation isolated TNF-inhibitory compounds, and HILIC-HPLC fraction composition was determined by NMR and mass spectrometry analyses. Histamine was identified and quantified in TNF-inhibitory HILIC-HPLC fractions. Histamine is produced from L-histidine via histidine decarboxylase by some fermentative bacteria including lactobacilli. Targeted mutagenesis of each gene present in the histidine decarboxylase gene cluster in L. reuteri 6475 demonstrated the involvement of histidine decarboxylase pyruvoyl type A (hdcA), histidine/histamine antiporter (hdcP), and hdcB in production of the TNF-inhibitory factor. The mechanism of TNF inhibition by L. reuteri-derived histamine was investigated using Toll-like receptor 2 (TLR2)-activated human monocytoid cells. Bacterial histamine suppressed TNF production via activation of the H2 receptor. Histamine from L. reuteri 6475 stimulated increased levels of cAMP, which inhibited downstream MEK/ERK MAPK signaling via protein kinase A (PKA) and resulted in suppression of TNF production by transcriptional regulation. In summary, a component of the gut microbiome, L. reuteri, is able to convert a dietary component, L-histidine, into an immunoregulatory signal, histamine, which suppresses pro-inflammatory TNF production. The identification of bacterial bioactive metabolites and their corresponding mechanisms of action with respect to immunomodulation may lead to improved anti-inflammatory strategies for chronic immune-mediated diseases

    Functionalized graphene oxide-reinforced electrospun carbon nanofibers as ultrathin supercapacitor electrode

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    Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process, non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10. F/g at the current density of 1. A/g, which was approximately three folds more than that of pristine nanofibers. It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure
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