Enantioselective Organocatalysis Using SOMO Activation Beeson, Teresa D; Mastracchio, Anthony; Hong, Jun-Bae ...
Science (American Association for the Advancement of Science),
04/2007, Letnik:
316, Številka:
5824
Journal Article
Recenzirano
The asymmetric α-addition of relatively nonpolar hydrocarbon substrates, such as allyl and aryl groups, to aldehydes and ketones remains a largely unsolved problem in organic synthesis, despite the ...wide potential utility of direct routes to such products. We reasoned that well-established chiral amine catalysis, which activates aldehydes toward electrophile addition by enamine formation, could be expanded to this important reaction class by applying a single-electron oxidant to create a transient radical species from the enamine. We demonstrated the concept of singly occupied molecular orbital (SOMO) activation with a highly selective α-allylation of aldehydes, and we here present preliminary results for enantioselective heteroarylations and cyclization/halogenation cascades.
Interstitial cystitis/bladder pain syndrome (IC/BPS) is an intractable disease characterized by severe pelvic pain and urinary frequency. Mesenchymal stem cell (MSC) therapy is a promising approach ...to treat incurable IC/BPS. Here, we show greater therapeutic efficacy of human embryonic stem cell (hESC)-derived multipotent stem cells (M-MSCs) than adult bone-marrow (BM)-derived counterparts for treating IC/BPS and also monitor long-term safety and in vivo properties of transplanted M-MSCs in living animals. Controlled hESC differentiation and isolation procedures resulted in pure M-MSCs displaying typical MSC behavior. In a hydrochloric-acid instillation-induced IC/BPS animal model, a single local injection of M-MSCs ameliorated bladder symptoms of IC/BPS with superior efficacy compared to BM-derived MSCs in ameliorating bladder voiding function and histological injuries including urothelium denudation, mast-cell infiltration, tissue fibrosis, apoptosis, and visceral hypersensitivity. Little adverse outcomes such as abnormal growth, tumorigenesis, or immune-mediated transplant rejection were observed over 12-months post-injection. Intravital confocal fluorescence imaging tracked the persistence of the transplanted cells over 6-months in living animals. The infused M-MSCs differentiated into multiple cell types and gradually integrated into vascular-like structures. The present study provides the first evidence for improved therapeutic efficacy, long-term safety, and in vivo distribution and cellular properties of hESC derivatives in preclinical models of IC/BPS.
Research issues on closed-loop PLM Jun, Hong-Bae; Kiritsis, Dimitris; Xirouchakis, Paul
Computers in industry,
12/2007, Letnik:
58, Številka:
8
Journal Article
Recenzirano
This study introduces the research issues on
closed-loop product lifecycle management (PLM) where product information flow is closed due to emerging technologies. PLM is a new strategic approach to ...manage the product lifecycle information efficiently over the whole product lifecycle. Recently, with emerging technologies, PLM enables us to gather and analyze the product lifecycle information and make decisions on several issues without spatial and temporal constraints. However, the PLM system just provides us with new opportunities to gain the competitiveness. To remove ineffectiveness within the product lifecycle and maximize the advantage of
closed-loop PLM, it is necessary to look into new challenging issues. For this purpose, first, we introduce the concept of
closed-loop PLM. Then, we explore several research problems that become highlighted in the
closed-loop PLM. For each product lifecycle phase, we introduce research issues with the review of their previous research and address the requirements for resolving them. Finally, we close with discussion about our work and introduction of further research issues.
Curcumin (CUR) has been used in the treatment of various diseases such as cough, fever, skin disease, and infection because of various biological benefits such as anti-inflammatory, antiviral, ...antibacterial, and antitumor activity. However, CUR is a BCS class 4 group and has a limitation of low bioavailability due to low solubility and permeability. Therefore, the purpose of this study is to prepare a nanosuspension (NSP) loaded with CUR (CUR-NSP) using a statistical design approach to improve the oral bioavailability of CUR, and then to develop CUR-NSP coated with tannic acid to increase the mucoadhesion in the GI tract. Firstly, the optimized CUR-NSP, composed of sodium dodecyl sulfate (SDS) and polyvinylpyrrolidone/vinyl acetate (PVP/VA), was modified with tannic acid (TA). The particle size and polydispersity index of the formulation measured by laser scattering analyzer were 127.7 ± 1.3 nm and 0.227 ± 0.010, respectively. In addition, the precipitation in distilled water (DW) was 1.52 ± 0.58%. Using a differential scanning calorimeter and X-ray diffraction analysis, the stable amorphous form of CUR was confirmed in the formulation, and it was confirmed that CUR-NSP formulation was coated with TA through a Fourier transform-infrared spectroscopy. In the mucoadhesion assay using the turbidity, it was confirmed that TA-CUR-NSP had higher affinity for mucus than CUR-NSP under all pH conditions. This means that the absorption of CUR can be improved by increasing the retention time in the GI tract of the formulation. In addition, the drug release profile showed more than 80% release, and in the cellular uptake study, the absorption of the formulation (TA-CUR-NSP) containing TA acting as an inhibitor of P-gp was increased by 1.6-fold. In the evaluation of antioxidant activity, the SOD activity of TA-CUR-NSP was remarkably high due to TA, which improves cellular uptake and has antioxidant activity. In the pharmacokinetic evaluation, the maximum drug plasma concentration of the TA-coated NSP formulation was 7.2-fold higher than that of the pure drug. In all experiments, it was confirmed that the TA-CUR-NSP is a promising approach to overcome the low oral bioavailability of CUR.
•An effective fault analysis method based on gathered sensor data is required.•A Bayesian network based approach for fault analysis is proposed.•Fault identification, inference, and sensitivity ...analysis methods are developed.•It will provide useful guidance for plant maintenance experts.
For high-value assets such as certain types of plant equipment, the total amount of resources devoted to Operation and Maintenance may substantially exceed the resources expended in acquisition and installation of the asset, because high-value assets have long useful lifetimes. Any asset failure during this useful lifetime risks large losses in income and goodwill, and decreased safety. With the continual development of information, communication, and sensor technologies, Condition-Based Maintenance (CBM) policies have gained popularity in industries. A successfully implemented CBM reduces the losses due to equipment failure by intelligently maintaining the equipment before catastrophic failures occur. However, effective CBM requires an effective fault analysis method based on gathered sensor data. In this vein, this paper proposes a Bayesian network-based fault analysis method, from which novel fault identification, inference, and sensitivity analysis methods are developed. As a case study, the fault analysis method was analyzed in a centrifugal compressor utilized in a plant.
In this study, we aimed to develop a novel method to quantify residual colorants in the water supply using a spectrocolorimeter. Cross-tests of color and turbidity showed that standard color ...solutions of 1–50 color units had a turbidity of ˂0.094 nephelometric turbidity unit (NTU) and turbidity standard solutions of 0.1–5 NTU had color measurements of 0 true color unit, indicating limitations in measuring colorants using conventional methods. Therefore, the samples were diluted stepwise to 1 L and filtered through a 0.45 μm cellulose membrane; then, the residuals colorants were measured using membrane filter colorimetry (MFC) with a spectrocolorimeter to determine the color difference. The color difference exhibited a high correlation with turbidity. Furthermore, scanning electron microscopy/energy-dispersive X-ray spectroscopy and inductively coupled plasma-optical emission spectrometry analyses of the same samples confirmed that the main components of the colorants were iron and manganese; the concentration of these substances in the samples was measured using MFC with the standards Fe2O3·H2O and MnO2. The results confirmed a high correlation between the color difference (△E*ab) and concentration of the samples and standard substances. Our findings suggest that MFC is a promising approach for measuring colorants in drinking water.
Biochemical methane potential tests and lab-scale continuous experiments were conducted to improve the yield and energy efficiency of anaerobic digestion through thermal hydrolysis pre-treatment. ...Methane generation, yield, and solubilization efficiency were evaluated through lab-scale tests. The pre-treated samples presented 50% biodegradability at 140 °C and 61.5% biodegradability at 165 °C. The increase in biodegradability was insignificant at 165 °C or higher temperature, and it was confirmed that the optimum conditions were achieved at 165 °C and 20 min of solubilization. The lab-scale continuous experiments confirmed that polymers were decomposed into low-molecular-weight compounds due to thermal hydrolysis, and pH decreased. NH4HCO3 produced by thermal hydrolysis acted as an alkali to enable a more stable operation compared to that before thermal hydrolysis. Total chemical oxygen demand as chromium (TCODCr) and soluble chemical oxygen demand as chromium (SCODCr) indicated 35.4% and 23.1% removal efficiency in terms of organic matter removal, respectively. Methane yield was approximately 0.35 kg m−3 at 2.0–4.0 kg (m3 d)−1 and 0.26 kg m−3 at 5.0 kg (m3 d)−1. The solubilization rate of 40.9% by thermal hydrolysis was confirmed through the lab-scale tests to determine its full-scale applicability.
Although serum bile acid concentrations are approximately 10 µM in healthy subjects, the crosstalk between the biliary system and vascular repair has never been investigated. In this study, ...tauroursodeoxycholic acid (TUDCA) induced dissociation of CD34(+) hematopoietic stem cells (HSCs) from stromal cells by reducing adhesion molecule expression. TUDCA increased CD34(+) /Sca1(+) progenitors in mice peripheral blood (PB), and CD34(+) , CD31(+) , and c-kit(+) progenitors in human PB. In addition, TUDCA increased differentiation of CD34(+) HSCs into EPC lineage cells via Akt activation. EPC invasion was increased by TUDCA, which was mediated by fibroblast activating protein via Akt activation. Interestingly, TUDCA induced integration of EPCs into human aortic endothelial cells (HAECs) by increasing adhesion molecule expression. In the mouse hind limb ischemia model, TUDCA promoted blood perfusion by enhancing angiogenesis through recruitment of Flk-1(+) /CD34(+) and Sca-1(+) /c-kit(+) progenitors into damaged tissue. In GFP(+) bone marrow-transplanted hind limb ischemia, TUDCA induced recruitment of GFP(+) /c-kit(+) progenitors to the ischemic area, resulting in an increased blood perfusion ratio. Histological analysis suggested that GFP(+) progenitors mobilized from bone marrow, integrated into blood vessels, and differentiated into VEGFR(+) cells. In addition, TUDCA decreased cellular senescence by reducing levels of p53, p21, and reactive oxygen species and increased nitric oxide. Transplantation of TUDCA-primed senescent EPCs in hind limb ischemia significantly improved blood vessel regeneration, as compared with senescent EPCs. Our results suggested that TUDCA promoted neovascularization by enhancing the mobilization of stem/progenitor cells from bone marrow, their differentiation into EPCs, and their integration with preexisting endothelial cells.
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