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991.
The construction of a reagentless, sensitive, disposable and multiplexed electronic sensing platform for one-spot simultaneous determination of biomolecules with significant difference in size (proteins and small molecules) is described. The sensing surface is fabricated by the hybridization of two types of redox-tags conjugated aptamers with the corresponding complementary DNAs, which are self-assembled on a gold nanoparticle-modified screen printed carbon electrode. The presence of the target analytes leads to the release of the tagged signaling aptamers from the sensing surface, and the surface-remained tags exhibit well-resolved peaks, whose positions and sizes reflect the identities and concentrations of the target analytes, respectively. The application of the proposed sensing platform for molecular logic gate operations is also demonstrated. 相似文献
992.
A multiple amplification immunoassay was proposed to detect alpha-fetoprotein (AFP), which was based on ferrocenemonocarboxylic-HRP conjugated on Pt nanoparticles as labels for rolling circle amplification (RCA). Firstly, the capture antibody (anti-AFP) was immobilized on glass carbon electrode (GCE) deposited nano-sized gold particles. After a typical immuno-sandwich protocol, primary DNA was immobilized by labeling secondary antibody, which acted as a precursor to initiate RCA. The products of RCA provide large amount of sites to link detection DNAs, which were labeled by signal probes (ferrocenemonocarboxylic) and horseradish peroxidase (HRP). Moreover, the enzymatic amplification signals could be produced by the catalysis of HRP and Pt nanoparticles with the addition of H?O?. These lead to multiple amplification signals monitoring by electrochemical instrument and further resulted in high sensitivity of the immunoassay with the detection limit of 1.7 pg/mL. 相似文献
993.
994.
995.
Stictodora lari Yamaguti, 1939 (Digenea: Heterophyidae) was originally reported as an avian intestinal parasite and is here reported in humans. The patients were adults, aged 46-69 (2 men and 4 women), who resided in coastal villages in Sachon-gun, Kyongsangnam-do, or Shinan-gun, Chollanam-do. in the Republic of Korea. The worms were recovered after praziquantel treatment and purgation with magnesium salts. A total of 15 S. lari specimens (1-10 per individual) was collected, together with 5 other species of intestinal flukes. The flukes were morphologically characterized by a small body size (0.70-0.86 mm long and 0.27-0.36 mm wide), a ventrogenital sac, and a gonotyl armed with 70-80 spines in the form of a comma or reversed comma lying along their lateral margin. The patients had eaten the raw flesh of mullets and gobies that had been caught in an estuary near their villages. To the best of our knowledge, this is the first record of a human S. lari infection. 相似文献
996.
A mediator-free amperometric hydrogen peroxide biosensor was prepared by immobilizing horseradish peroxidase (HRP) enzyme
on colloidal Au modified platinum (Pt) wire electrode, which was modified by poly 2,6-pyridinediamine (pPA). The modified
process was characterized by electrochemical impedance spectroscopy (EIS), and the electrochemical characteristics of the
biosensor were studied by cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The biosensor displayed an excellent
electrocatalytical response to reduction of H2O2 without the aid of an electron mediator, the linear range was 4.2 × 10−7–1.5 × 10−3 mol/L (r = 0.9977), with a detection limit of 1.4 × 10−7 mol/L. Moreover, the performance and factors influencing the resulted biosensor were studied in detail. The studied biosensor
exhibited permselectivity, good stability and good fabrication reproducibility. 相似文献
997.
Seray Adams Charles Teo Kerrie L. McDonald Anna Zinger Sonia Bustamante Chai K. Lim Gayathri Sundaram Nady Braidy Bruce J. Brew Gilles J. Guillemin 《PloS one》2014,9(11)
The kynurenine pathway (KP) is the principal route of L-tryptophan (TRP) catabolism leading to the production of kynurenine (KYN), the neuroprotectants, kynurenic acid (KYNA) and picolinic acid (PIC), the excitotoxin, quinolinic acid (QUIN) and the essential pyridine nucleotide, nicotinamide adenine dinucleotide (NAD+). The enzymes indoleamine 2,3-dioxygenase-1 (IDO-1), indoleamine 2,3-dioxygenase-2 (IDO-2) and tryptophan 2,3-dioxygenase (TDO-2) initiate the first step of the KP. IDO-1 and TDO-2 induction in tumors are crucial mechanisms implicated to play pivotal roles in suppressing anti-tumor immunity. Here, we report the first comprehensive characterisation of the KP in 1) cultured human glioma cells and 2) plasma from patients with glioblastoma (GBM). Our data revealed that interferon-gamma (IFN-γ) stimulation significantly potentiated the expression of the KP enzymes, IDO-1 IDO-2, kynureninase (KYNU), kynurenine hydroxylase (KMO) and significantly down-regulated 2-amino-3-carboxymuconate semialdehyde decarboxylase (ACMSD) and kynurenine aminotransferase-I (KAT-I) expression in cultured human glioma cells. This significantly increased KP activity but significantly lowered the KYNA/KYN neuroprotective ratio in human cultured glioma cells. KP activation (KYN/TRP) was significantly higher, whereas the concentrations of the neuroreactive KP metabolites TRP, KYNA, QUIN and PIC and the KYNA/KYN ratio were significantly lower in GBM patient plasma (n = 18) compared to controls. These results provide further evidence for the involvement of the KP in glioma pathophysiology and highlight a potential role of KP products as novel and highly attractive therapeutic targets to evaluate for the treatment of brain tumors, aimed at restoring anti-tumor immunity and reducing the capacity for malignant cells to produce NAD+, which is necessary for energy production and DNA repair. 相似文献
998.
Ground squirrel, a hibernating mammalian species, is more resistant to ischemic brain stress than rat. Gaining insight into the adaptive mechanisms of ground squirrels may help us design treatment strategies to reduce brain damage in patients suffering ischemic stroke. To understand the anti-stress mechanisms in ground squirrel neurons, we studied glutamate toxicity in primary cultured neurons of the Daurian ground squirrel (Spermophilus dauricus). At the neuronal level, for the first time, we found that ground squirrel was more resistant to glutamate excitotoxicity than rat. Mechanistically, ground squirrel neurons displayed a similar calcium influx to the rat neurons in response to glutamate or N-methyl-D-aspartate (NMDA) perfusion. However, the rate of calcium removal in ground squirrel neurons was markedly faster than in rat neurons. This allows ground squirrel neurons to maintain lower level of intracellular calcium concentration ([Ca2+]i) upon glutamate insult. Moreover, we found that Na+/Ca2+ exchanger (NCX) activity was higher in ground squirrel neurons than in rat neurons. We also proved that overexpression of ground squirrel NCX2, rather than NCX1 or NCX3, in rat neurons promoted neuron survival against glutamate toxicity. Taken together, our results indicate that ground squirrel neurons are better at maintaining calcium homeostasis than rat neurons and this is likely achieved through the activity of ground squirrel NCX2. Our findings not only reveal an adaptive mechanism of mammalian hibernators at the cellular level, but also suggest that NCX2 of ground squirrel may have therapeutic value for suppressing brain ischemic damage. 相似文献
999.
A pharmacophore for increasing HDLC was proposed based on common structural features of non-thio-containing compounds with HDLC enhancing properties. A search of the compound database identified various series of these non-thio-containing compounds, including a novel tricyclic imidazoisoquinolone. Preparation of 1-aryl-3-oxo-1,3-dihydro-2-benzofuran-1-carboxamides using a novel and widely applicable one-step process from 2-acyl benzoic acids is reported. Reaction of diamines with 1-aryl-3-oxo-1,3-dihydro-2-benzofuran-1-carboxamides and related aza-analogues proceeded with regio-control to furnish imidazoisoquinolones, pyrimidoisoquinolones, and imidazonaphthyridines. NMR studies and X-ray crystallography confirmed the regiochemistry of the products. Compounds of these series increased concentrations of HDLC in test animals following oral administration. 相似文献
1000.
Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases. Using map-based strategy and in silico approach we isolated a new rice (Oryza sativa L.) blast resistance allele of Pid3, designated Pi25, from a stable blast resistance cultivar Gumei2. Overexpression analysis and complementation test showed that Pi25 conferred blast resistance to M. oryzae isolate js001-20. Sequence analysis showed that Pi25 was an intronless gene of 2772 nucleotides with single nucleotide substitution in comparison to Pid3 at the nucleotide position 459 and predicatively encoded a typical coiled coil-nucleotide binding site-leucine rich repeat (CC--NBS--LRR) protein of 924 amino acid residuals with 100% identity to Pid3 putative protein. The susceptible allele pi25 in Nipponbare contained a nonsense mutation at the nucleotide position 2209 resulting in a truncated protein with 736 amino acid residuals. In addition, 14 nucleotide substitutions resulting in 10 amino acid substitutions were identified between Pi25 and pi25 upstream the premature stop codon in the susceptible allele. Although the mechanism of Pi25/Pid3-mediated resistance needs to be further investigated, the isolation of the allele would facilitate the utilization of Pi25/Pid3 in rice blast resistance breeding program via transgenic approach and marker assisted selection. 相似文献