cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2010.740
title: Effect of gold nanoparticles on cytochrome P450 gene expression in HEPG2 cell line

description: Gold nanoparticles (AuNPs) have been recently used for many clinical applications including drug delivery, therapeutics and diagnostics. AuNPs were synthesized by using the chemical reduction method with different stabilizers, citrate and polyethyleneimine (PEI), the AuNPs were determined for their effect on human cytochrome P450 (CYP) mRNA induction, namely CYP1A1, CYP1A2, CYP2C9, CYP2E1 and CYP3A4, using real-time PCR technique. The average particle diameters of freshly prepared citrate- and PEI-stabilized AuNPs were 15.00 ± 2.77 and 5.02 ± 1.81 nm, respectively. The zeta potentials of citrate and PEI-stabilized AuNPs were -40.60 ± 1.22 and 8.10 ± 1.59 mV, in orderly. Citrate-stabilized AuNPs (AuCi) has shown to have no cytotoxicity on HepG2 cells at the maximum concentration of 90 µM whereas IC₅₀ of PEI-stablilized AuNPs (AuPEI) was found to be 37.58 ± 1.15 µM. The significance in induction effect (p≤0.05) of AuCi at 10 µM observed on CYP1A2 and CYP2C9 was 2.32 ± 0.35 and 1.65 ± 0.39 folds, consecutively. AuPEI at a concentration of 1 µM significantly induced (p≤0.05) CYP1A1 and CYP1A2 up to 1.68 ± 0.35 and 2.08 ± 0.56 folds, respectively. The mixtures of AuNPs and CYP inducers, α-naphthoflavone for CYP1A and rifampicin for CYP2C9 and CYP3A4, decreased the effect of inducers significantly (p≤0.05) on CYP1A1, CYP1A2, CYP2C9 and CYP3A4 for AuCi, and on CYP1A1, CYP2C9 and CYP3A4 for AuPEI. Noticeably, the mixture of AuPEI at 1 µM and the inducer had a synergistic induction on CYP1A2 (p≤0.05). The potential of CYP induction of AuNPs seemed to depend upon the size and charge of AuNPs. AuPEI was about 3 times smaller in size than AuCi and contained positive charges which could support the cellular penetration. Nevertheless, the mechanism of CYP induction by AuNPs are suggested for further study.
DOI: 10.14457/cu.the.2010.741
title: Notch signaling regulates apoptosis in Macrophages infected with mycobacteria

description: Apoptosis of macrophages infected with pathogens is considered to be one of the important host immune responses. Previously, Mcl-1 expression was found to be up-regulated in monocytes/macrophages during infection with virulent Mycobacterium tuberculosis (Mtb), a causative agent of tuberculosis. Myeloid cell leukemia-1 (Mcl-1) is a pro-survival member of the Bcl-2 protein family. The regulatory mechanism of Mcl-1 expression in macrophages is not well characterized. In this study, upregulation of Mcl-1 in bone marrow derived macrophages (BMM ) and macrophage-like cell line RAW264.7 were observed when cells were treated with Mtb-derived purified protein derivatives (PPD) or infected with Mycobacterium bovis BCG (M. bovis BCG). The Notch signaling pathway is a highly conserved cell signaling pathway present in most multicellular organisms. Notch signaling modulates numerous cellular functions such as proliferation, adhesion, angiogenesis and apoptosis. Recent studies reported that Notch signaling is activated in macrophages during infection with M. bovis BCG. We found a well correlation between Mcl-1 and Notch1 expression in PPD-activated or M. bovis BCG-infected macrophages. In addition, cleaved Notch1, an indicator of activated Notch signaling pathway, was detected upon PPD treatment of macrophages, suggesting that Notch signaling is activated. Treatment with y- secretase inhibitor (GSI), a specific inhibitor of Notch signaling, or knockdown of Notch1 resulted in decreased expression of Mcl-1 and increased apoptosis of infected macrophages. Since a conserved potential binding site for CSL, a DNA binding protein and interacting partner with Notch, was identified in the promoter region of mcl-1, chromatin immunoprecipitation (ChIP) assay was used to determine whether Notch1 directly binds to mcl-1 promoter. ChIP assay clearly demonstrated that stimulation with PPD recruited intracellular Notch to the mcl-1 promoter. Taken together, these results suggested that Notch signaling directly regulates Mcl-1 expression in macrophages upon treatment with PPD or infection with M. bovis BCG. This new function of Notch1 in regulating Mcl-1 expression in antibacterial immunity may open a new strategy to manipulate host immune response against tuberculosis.
DOI: 10.14457/cu.the.2010.742
title: Fluorescence probe for D-glucose and beta-glucosidase based on anthraquinone imidazole fluorophores

description: The anthaquinone derivatives containing boronic acid or glycoside as an active site were synthesized and characterized by spectroscopy. We have developed the boronic anthaquinone based sensors (OB and PB) for glucose sensing by the enzymatic probe system with glucose oxidase. Actually, the glucose oxidase can react with glucose and oxygen to generate the gluconic acid and hydrogen peroxide. In consistent with our hypothesis, the generated H₂O₂ can convert the boronic moiety of sensors to be hydroxyl group resulting in the fluorescence quenching of sensor OB. The advantage of this sensor is that it can detect glucose specifically. The kinetic of this process measured by Michaelis-Menten constant (Km) provided the Km values of 0.174 mM, indicating that OB exhibits a higher affinity for glucose oxidase. The limit of detection (LOD) of glucose for OB evaluated in the range of 0.08-0.42 mM of glucose by the spectrofluorometry was 0.0114 mM. Moreover, the glycoside anthaquinone based sensors (OAG and PAG) bearing the anthraquinone as a sensory unit and glucoside as a active site were synthesized to detect β-glucosidase. After adding β-glucosidase, the fluorescence decreases of PAG were observed due to the cleavage of O-glucoside. The results showed that PAG can be a sensor for determining β-glucosidase in enzymatic probe system with the observation of fluorescence change. To improve the sensitivity of PAG for β-glucosidase sensing, we have applied PAG in the micellar system using CTAB as surfactant for enzymatic probe. This micellar system could reduce background signal from β-glucosidase and enhance the emission signal of PAG. Therefore, PAG in the micellar system can serve as a high potential for the β-glucosidase sensing. Finally, we tried to apply PAG in surfactant/lanthanide nanoparticles. The results also exhibited the enhancement of emission band of PAG in lanthanide nanoparticles and after adding β-glucosidase, the fluorescence intensity of PAG was significantly quenched. All approaches are exemplified by their application to develop a novel and highly sensitive fluorescence probe for β-glucosidase, which is widely used as the reporter of enzymes.
DOI: 10.14457/cu.the.2010.743
title: Electrospinning of poly (ethylene oxide)/alginate nanofibers containing estradiol/beta-cyclodextrin complex

description: Alginate is a polymer widely used in drug delivery field in the form of micro/nanoparticles. This work presents the new technique for preparation of alginate as nanofiber and its pharmaceutical application as a transdermal hormone drug delivery system using estradiol as a model drug. These can be archived by electrospinning the blend of alginate/poly (ethylene oxide) (PEO)/β-cyclodextrin (β-CD) by using PEO to decrease the repulsive force of alginate and using β-CD to increase the compatibility of hydrophobic drug with the hydrophilic polymer system. The electrospinning parameters for preparation the well-formed nanofibers including solution concentration, mass ratio of polymers, applied voltage, flow rate and working distance were investigated. The morphology and size of nanofiber were investigated by Scanning Electron Microscope (SEM) and the physical properties were investigated by Fourier transformed infrared spectroscopy (FT-IR) and X-rays Diffractometer The well-formed nanofibers PEO/Alg/β-CD with the diameter size less than 200 nm were successively prepared from 2:1:2 (w/w/w) of PEO/Alg/β-CD at 20 kV, 18 cm, 1.3 ml/hr. To investigate the possibility of PEO/Alg/β-CD nanofibers as transdermal estradiol delivery systems, the estradiol were formed an inclusion complex with β-CD before added to the polymer blend. The encapsulation efficiency and in vitro release behavior were investigated by UV spectophotometer. The high entrapment efficiency of 93% of estradiol was obtained from the nanofibers containing 1:1 mole ratio of estradiol/β-CD complex. The estradiol loaded nanofiber could be sustained released the drug within 7 days in 25% (v/v) ethanol/phosphate buffered saline (pH 7.4) at 37°C. The permeation study of estradiol through cellulose acetate membrane as a simulated skin (Franz’s cell) provided controlled release for 7 days with flux of 10.431 µg/cm2.day.
DOI: 10.14457/cu.the.2010.744
title: Heterologous expression of pyrroline-5-carboxylate reductase ana L-Lysine-6-dehydrogenase genes for L-pipecolic acid production

description: L-pipecolic acid (L-PA) is a non-protein amino acid. It is an important precursor of many useful microbial secondary metabolites such as an immunosuppressant rapamycin. This research aims to produce L-PA by coupling reaction of lysine 6-dehydrogenase (Lys 6-DH) and pyrroline-5-carboxylate reductase (P5CR). The lys 6-dh gene from Acromobacter denitrificans was already cloned into Escherichia coli BL21(DE3) in previous research. Therefore, in this study proC encoding P5CR from Bacillus cereus ATCC 11778 was cloned into an expression vector pET-17b and then transformed to E. coli BL21(DE3). The optimum condition for proC expression was induction with 0.4 mM IPTG for 4 hours. The enzyme was purified 2.25 fold by DEAE-Toyopearl and Butyl-Toyopearl column chromatographies with 14.9% yield. The molecular mass of enzyme subunit was about 28.9 kDa. The apparent Km for L-proline and NAD+ were 1 and 1.54 mM, respectively. The obtained proC was co-expressed with the lys 6-dh in E. coli BL21(DE3) in order to produce L-PA. The production of L-PA, approximately 1.74 g/l, was obtained by induction of the recombinant clone with 0.1 mM IPTG for 4 hours and then 0.05 g of cell wet weight was incubated in the reaction mixture consisted of 200 mM L-lysine in 200 mM Tris-HCl buffer, pH 9.0 for 24 hours.
DOI: 10.14457/cu.the.2010.745
title: Determination of epoxide equivalent weight of epoxy resin using fourier transform near infrared spectroscopy

description: The epoxide equivalent weight (EEW) of epoxy resin is the weight of resin in grams which contains one gram equivalent of epoxy groups. The EEW values must be accurately determined in order to calculate the exact amount of the hardener that will react with the epoxide group leading to cross-linked polymer of the desired properties. In this study, a method for determination of EEW values was developed using Fourier transform near infrared (FT-NIR) spectroscopy and partial least squares (PLS) regression to construct a prediction model. The predicted EEW values of unknown epoxy resins were compared with EEW values obtained from a reference method, based on titration of epoxy resin with hydrogen bromide generated in situ. The EEW values of both methods agreed well as shown by performance parameters RMSEC, RMSEP, and R values of 0.4265 g/eq, 0.4131 g/eq, and 0.9580, respectively. The newly developed method could be applied for routine analysis of EEW values of epoxy resin as it is simple, fast, accurate, non-destructive and environmental friendly.
DOI: 10.14457/cu.the.2010.746
title: Synthesis of triphenylamine-porphyrin derivatives as pho-sensitizers in solar cells

description: In this research, synthesis of porphyrinic compounds and investigation of their electrochemical and photophysical properties are described. Three novel porphyrinic compounds were synthesized by a copper-free Sonogashira coupling reaction between tris(4-iodophenyl)amine and 5,10,15-triphenyl-20-(4-ethynylphenyl)porphyrin. The completely coupled product having a triphenylamine core and three peripheral porphyrin moieties will be used as a photo-sensitizer in a bulk heterojunction solar cell. The di-substituted derivative was subjected to another Sonogashira coupling of the remaining terminal iodo group with two different surface anchoring units to obtain porphyrin products for dye-sensitized solar cells. Cyclic voltammetry and photoluminescence study of these compounds were performed to determine the potential of these compounds for being used in the solar cells.
DOI: 10.14457/cu.the.2010.747
title: Chitosan derivative nanoparticles for controlled release of aldehydes

description: This research was able to prepare double barrier controlled release system consisting of a polymeric barrier through chitosan’s derivation (N-succinylchitosan) and a chemical barrier through aldehyde’s derivation (Schiff base) under heterogeneous phase reaction. N-succinylchitosan was synthesized based on the reaction of chitosan with succinic anhydride, and the obtained polymer could self-assemble into spherical nanoparticles in aqueous medium. The amino groups on the surface of the obtained particles could form Schiff base with fragrant aldehydes including vanillin, cinnamaldehyde, citronellal and citral. All the Schiff base moieties were located at the inside of the particles as confirmed by X-ray photoelectron spectroscopic analysis (XPS). All obtained Schiff base nanoparticles gave stable nanospheres, whose hydrodynamic diameters were in the range of 80 to 165 nm. The prolonged release of the grafted aldehydes from the obtained double barrier systems was demonstrated.
DOI: 10.14457/cu.the.2010.748
title: The role of notch signaling pathway in polarization of macrophages in mice

description: Notch signaling is a well conserved signaling pathway which is involved in regulation of cell fate determination, differentiation, proliferation and cell death of various cell types. Interaction between Notch receptors and ligands initiates the signaling cascade, resulting in transcription of its target genes. Previous studies demonstrated that Notch signaling regulates effector functions of innate immune cells, macrophages, such as production of TNFα and nitric oxide, partly through interaction with other signaling pathways. The phenotypes of macrophages are highly plastic, depending on the microenvironment they are surrounded. At least three types of different effector macrophages have been described, i.e. classically activated macrophages (CA-MФ), alternatively activated macrophages (AA-MФ) and regulatory macrophages (Reg-MФ). In these studies, we investigated the expression of Notch receptors and their ligands in different types of effector macrophages, and the relationship of Notch signaling pathway and other well characterized signaling pathways using murine bone marrow derived macrophages. Polarization of macrophages were confirmed by monitoring the expression of marker genes, arginase1 (Arg1), il12p40 and il10 for AA, CA and Reg-MФ, respectively. Western blot revealed that Notch1 is highly expressed in CA and regulatory macrophages. The level of Notch1 correlated with the appearance of cleaved Notch1 (Val1744) in these 2 types of macrophages. In addition, distinct patterns of ligand expression and Notch target gene, Hes1, in different types of macrophages were observed. Upon inhibition of Notch signaling by gamma secretase inhibitor (GSI), altering in gene expression of key markers for each type was observed. GSI treatment resulted in decreased il10, il12p40 and il23p19 mRNA expression in CA and Reg-MФ, but did not affect arg1 mRNA level in AA-MФ. Moreover, inhibiting Notch signaling affected the status of MAP kinase pathway. Reduced phosphorylation of ERK1/2 was seen in CA-MФ upon GSI treatment. Taken together, we proposed that Notch signaling plays an essential role in regulating differentiation of effector macrophages partly by interacting and regulating MAP kinase pathway.
DOI: 10.14457/cu.the.2010.749
title: Purification and characterization of xylanase from endophytic fungus Alternaria alternata isolate PTRa9

description: Microorganisms were the major sources of xylanase production due to there were important in agriculture and industrial. The aim of this research was to study the xylanase production from endophytic fungi. Totally 54 endophytes isolated from Corton oblongifolius Roxb., Palm and mangrove leaves were tested for xylanase activity. There were only 31 endophytes isolated produce clear zone around colony in selective xylan agar medium which indicated xylanase-producing in primary screening. Endophyte isolate PTRa9 yield the highest xylanase-production in secondary screening. The optimal conditions that PTRa9 produced highest xylanase activity when 2% rice bran and 0.1% (NH₄)₂SO₄ as carbon and grew in the medium supplemented with nitrogen source, respectively for 4 days. Xylanase purification was done by ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography which resulted in an apparent increase in specific activity as 161.1 U/mg protein and 60.8 times of purity. Xylanase characterization includes thermal stability, pH stability, metal ions, kinetic analysis and molecular weight were studied and the result showed that at 40°C for 20 min, at pH range 3 to 11 for 60 min had relative xylanase activity of 131.27 and higher than 100 %, respectively. PTRa9 xylanase was strongly inhibited by Hg²⁺, and was moderately inhibited by Mg²⁺, Mn²⁺, Cu²⁺, Zn²⁺, Fe²⁺ and EDTA. For kinetic analysis, it had Km of 2.369 mg/ml and Vmax of 2.142 µl/min/mg protein. Molecular weight of Xylanase of PTRa9 was of 54.8 kDa.
DOI: 10.14457/cu.the.2010.750
title: Improving cold flow property of biodiesel from Irvingia malayana Oliv. ex A. Benn. seeds

description: This research aimed to improve the cold flow property of biodiesel from Irvingia malayana Oliv. ex A. Benn. (IM) seeds by using four synthesized Pour Point Depressant (PPDs) which were methyl laurate (ML), methyl stearate (MS), i-propyl laurate (IPL) and i-propyl stearate (IPS) and five commercial additives which were CD017, Zenith, Flozol 2251D, Flozol 112 and kerosene. Among of these additives, IPL gave the best result on improving cold flow property of biodiesel from IM oil (IMME), at which 500,000 ppm of IPL, cloud point (CP) and pour point (PP) of IMME were reduced by 8.70±1.0°C and 9.0±1.0°C, respectively. In addition, the cold flow property could be effected by the types of hydrocarbon chain. At the same concentration of IPL and ML, the branched chain alcohol gave the best result on improving cold flow property by which the CP and PP of IMME were reduced by 1.55±1.0°C (17.82%) and 4.0±1.0°C (44.44%), respectively. On the other hand, the cold flow property of IMME could not be improved by using MS and IPS because of the molecular weight of MS and IPS were higher than that of IMME. For commercial additives, kerosene gave the best result on reducing CP and PP of IMME.
DOI: 10.14457/cu.the.2010.751
title: Purification and characterization of lipase from endophytic fungus Alternaria alternata isolate PTM7

description: Sixty five endophytic fungal isolates, were tested for extracellular lipase production. Only ten isolates were found to produce lipase activity. Fusarium oxysporum isolated PTM 7, which was isolated from Croton oblongifolius Roxb. (Plao yai leaves), gave the highest activity. Highest lipase activity PTM 7 was shown in the basal culture medium was supplemented with 1% (v/v) olive oil, 1% (w/v) peptone and 0.5% (w/v) sodium nitrate as the carbon, organic and inorganic nitrogen sources, respectively. Purification PTM 7 extracellular lipase by precipitated in 80% saturation ammonium sulfate and molecule separation by DEAE-cellulose anion exchange and Superdex-75 gel filtration chromatography increased 41.4 in time apparent homogeneity but final yield decreased to 2.21 percent. The enriched lipase showed maximum stability at pH 8.0 and 30oC, was reasonably stable up to 40°C and at pH between 8.0 to 12.0. One mM Ca²⁺ and Mg²⁺ stimulated enzyme production and especially Mn²⁺ stimulated 133%, but inhibited by Cu2+, Fe²⁺, Hg²⁺ and Zn²⁺ 1 - 10 mM. 5 and 10 mM EDTA inhibited lipase activity but stimulatory at 1 mM. The Km and Vmax values were rather low at 2.78 mM and 9.09 mol/min/mg protein, respectively, when using p-nitrophenyl palmitate as the substrate. Enzymatic transesterification, which ratio of oil : methanol mole (1 : 6) and 6 U enzyme for biodiesel production was rather low only 28.4% FAMEs yield.
DOI: 10.14457/cu.the.2010.752
title: Quaternized chitosan particles prepared by self-assembly of amphiphilic chitosan

description: Quaternized chitosan particles were prepared by self assembly of amphiphilic chitosan having phthaloyl (Ph), hexyl (He) or dodecyl (Do) groups as hydrophobic entity and poly(ethylene glycol)methyl ether (mPEG) or N-[(2-hydroxyl-3-trimethylammonium)]propyl (HTAP) groups as hydrophilic entity that were immobilized on chitosan via chemical reactions of amino and/or hydroxyl groups. Unlike the chitosan particles having HTAP moieties, a subsequent heterogeneous methylation was necessary to introduce positively charged quaternary ammonium groups to the particles having mPEG moieties. Chemical structures of all amphiphilic chitosan derivatives were verified by 1H NMR and FT-IR spectroscopy. The relative degree of substitution (%DS) of each functionality can be varied as a function of mole equivalent of reagent used in each step of reaction. All quaternized amphiphilic chitosan exhibited a critical micelle concentration in a range of 7-17 µg/mL. According to SEM analysis, the particles have spherical morphology and a size range of 100–300 nm which is independent on %DS variation. And only the particles having He and Do as hydrophobic entities and HTAP as hydrophilic entities having degree of quaternization more than 50% exhibited high positive charges.
DOI: 10.25919/5d64df4b4c3e6
title: Parkes observations for project PX500 semester 2019APRS_19

description: This proposal relates to time purchased by the Chinese Academy of Sciences for Parkes follow-up confirmation and timing of FAST discoveries. As the observing time has been purchased this proposal (and the related PX501) does not require TAC grading. The primary reason for submitting a proposal is to ensure an outreach statement and that the proposal is entered into OPAL for the data archive to access. The Chinese team have two time requests. The time scheduled for the first, relating to this proposal, will be allocated in blocks of 24 hours and the data will become available in the data archive with an 18 month embargo period. The second type of time will be scheduled in shorter blocks and the data archived with a 10 year embargo.
DOI: 10.25919/5d64df7b645c7
title: Parkes observations for project P1008 semester 2019APRS_01

description: Magnetic field measurements of the Solar wind (SW) are extremely challenging, especially at close angular distances from the Sun. If they are obtained by measuring Faraday rotation of the radiation of background sources like active galactic nuclei, they are typically dependent on models of the electron density distribution in the heliosphere. However, pulsars can provide simultaneous, model-independent measurements of the electron density along the line-of-sight, along with Faraday Rotation estimates, and thus direct measurements of the SW magnetic field. Moreover, high-precision pulsar timing experiments such as Pulsar Timing Arrays (PTAs) can be strongly affected by the free electron distribution in the SW, and it is fundamentally important to understand, model and mitigate its influence on PTAs signals. With this proposal we aim to obtain high-cadence and precise measurements of the magnetic field and the electron density distribution of the SW by tracking three pulsars with low- to mid-ecliptic latitudes during their Solar approaches, and to reconstruct the SW dependence on the heliographic latitude. This will allow us to characterise the magnetic field of the SW and to collect precious information about the short-term fluctuations in the electron density that can appear as correlated noise in PTAs.